Patent Description:
Since laminated glass generates only a small amount of scattering glass fragments even when subjected to external impact and broken, laminated glass is excellent in safety. As such, the laminated glass is widely used for automobiles, railway vehicles, aircraft, ships, buildings and the like. The laminated glass is produced by sandwiching an interlayer film for laminated glass between a pair of glass plates.

Moreover, in order to adjust the adhesive force between an interlayer film and a glass plate, a compound containing magnesium is sometimes used. In general, since the adhesive force between an interlayer film and a glass plate is too high, laminated glass fails to absorb the impact at a collision when a human body or the like collides with the laminated glass. As such, in order to weaken the adhesive force between an interlayer film and a glass plate, a compound containing magnesium is used.

As an example of the interlayer film for laminated glass prepared with a compound containing magnesium, the following Patent Document <NUM> discloses a sound insulating layer including <NUM> parts by weight of a polyvinyl acetal resin with an acetalization degree of <NUM> to <NUM>% by mole, <NUM> to <NUM> part by weight of at least one kind of metal salt among an alkali metal salt and an alkaline earth metal salt, and a plasticizer in an amount greater than <NUM> parts by weight.

Patent Document <NUM> discloses an interlayer film for laminated glass in which whitening at a peripheral part and the deterioration of adhesive strength under high humidity are suppressed. The interlayer film comprises <NUM> parts by weight of polyvinyl butyral resin, <NUM> to <NUM> parts by weight of a plasticizer, <NUM> to <NUM> parts by weight of a metal carboxylate, <NUM> to <NUM> parts by weight of a dicarboxylic acid compound, and optionally <NUM> to <NUM> parts by weight of a modified silicone oil. Preferably, the metal carboxylate is magnesium acetate.

Even when a compound containing magnesium is added in order to weaken the adhesive force, the adhesive force sometimes fails to be lowered. Furthermore, there is a problem that the adhesive force of an interlayer film to a glass plate varies depending on the water content in the interlayer film.

On the other hand, there is a problem that, when magnesium is excessively added, this causes the moisture resistance of laminated glass to be lowered.

In laminated glass prepared with a conventional interlayer film as described in Patent Document <NUM>, there is a problem that achieving both high moisture resistance and moderate adhesive force is difficult.

Moreover, an interlayer film and laminated glass are used in various environments and the interlayer film is sometimes changed in its water content. There is a problem that, when the interlayer film is changed in its water content, the adhesive force to a glass plate is liable to vary.

An object of the present invention is to provide an interlayer film for laminated glass which is high in moisture resistance and has a moderate adhesive force. Moreover, the present invention is also aimed at providing laminated glass prepared with the interlayer film for laminated glass.

In a first aspect as defined in claim <NUM>, the present invention thus relates to an interlayer film for laminated glass. The interlayer film has a one-layer structure or a two or more-layer structure and contains a thermoplastic resin, wherein the thermoplastic resin contains a polyvinyl butyral resin. A portion on a first surface of the interlayer film is measured for Ratio<NUM> of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin with the use of TOF-SIMS, and a sputtering and measurement process in which the first surface portion measured for Ratio<NUM> is subjected to sputtering one time and measured for Ratio of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin with the use of TOF-SIMS is performed n times, and n Rations of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to n-th sputtering and measurement processes are collected to calculate an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, wherein, among these five average values, the average value indicating the smallest value is the average value<NUM> ≤ n ≤ <NUM> or the average value<NUM> ≤ n ≤ <NUM> and the average value indicating the largest value is the average value<NUM> ≤ n ≤ <NUM>, the average value<NUM> ≤ n ≤ <NUM>, or the average value<NUM> ≤ n ≤ <NUM>. In the case of an interlayer film with the one-layer structure, the content of magnesium in the interlayer film is <NUM> ppm or less and the content of potassium in the interlayer film is <NUM> ppm or less. In the case of an interlayer film with the two or more-layer structure, the content of magnesium in a surface layer positioned at the first surface side is <NUM> ppm or less, and the content of potassium in the surface layer positioned at the first surface side is <NUM> ppm or less.

Specific embodiments of the interlayer film for laminated glass according to the present invention are described in claims <NUM> to <NUM>.

In a second aspect as defined in claim <NUM>, the present invention relates to a laminated glass. The laminated glass includes a first lamination glass member, a second lamination glass member and an interlayer film part arranged between the first lamination glass member and the second lamination glass member, the interlayer film part being formed of the interlayer film for laminated glass of the first aspect.

Since the interlayer film for laminated glass according to the present invention has a one-layer structure or a two or more-layer structure and contains a thermoplastic resin, wherein the first surface side is measured as above and n Rations of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to n-th sputtering and measurement processes are collected to calculate an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, among these five average values, the average value indicating the smallest value is the average value<NUM> ≤ n ≤ <NUM> or the average value<NUM> ≤ n ≤ <NUM> and the average value indicating the largest value is the average value<NUM> ≤ n ≤ <NUM>, the average value<NUM> ≤ n ≤ <NUM>, or the average value<NUM> ≤ n ≤ <NUM>, laminated glass prepared with the interlayer film can be made to become high in moisture resistance and to have a moderate adhesive force.

Hereinafter, the details of the present invention will be described.

The interlayer film for laminated glass (hereinafter, sometimes described as the interlayer film) according to the present invention has a one-layer structure or a two or more-layer structure. The interlayer film according to the present invention may have a one-layer structure and may have a two or more-layer structure. The interlayer film according to the present invention may have a two-layer structure and may have a three or more-layer structure. The interlayer film according to the present invention is provided with a first layer. The interlayer film according to the present invention may be a single-layered interlayer film provided with only the first layer and may be a multilayered interlayer film provided with the first layer and another layer.

The interlayer film according to the present invention contains a thermoplastic resin, namely a thermoplastic resin containing a polyvinyl butyral resin. The interlayer film according to the present invention has a first surface and a second surface opposite to the first surface. The first surface and the second surface are oppositely directed. The first surface is a surface on which a first lamination glass member is layered. The second surface is a surface on which a second lamination glass member is layered.

With the use of TOF-SIMS, a portion on a first surface of the interlayer film according to the present invention is measured for Ratio<NUM> of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin.

Next, a sputtering and measurement process in which the first surface portion measured for Ratio<NUM> is subjected to sputtering one time and measured for Ratio of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin with the use of TOF-SIMS is performed n times. n Rations of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to n-th sputtering and measurement processes are collected.

For example, when the sputtering and measurement process is performed <NUM> times, <NUM> Ratios of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to 150th sputtering and measurement processes are collected. For example, in the second sputtering and measurement process, the first surface portion measured for Ratio<NUM> is subjected to sputtering and measurement. In the third sputtering and measurement process, the first surface portion measured for Ratio<NUM> is subjected to sputtering and measurement.

In the interlayer film according to the present invention, (Number <NUM> requirement) among five average values of an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, the average value indicating the smallest value is the average value<NUM> ≤ n ≤ <NUM> or the average value<NUM> ≤ n ≤ <NUM> and the average value indicating the largest value is the average value<NUM> ≤ n ≤ <NUM>, the average value<NUM> ≤ n ≤ <NUM>, or the average value<NUM> ≤ n ≤ <NUM>.

In the present invention, by being provided with the above-mentioned constitution, laminated glass prepared with the interlayer film can be made to become high in moisture resistance and to have a moderate adhesive force. Even if the interlayer film is changed in its water content, the adhesive force can be moderately maintained.

In order to adjust the adhesive force between an interlayer film and a glass plate, a compound containing magnesium is sometimes used. In general, since the adhesive force between an interlayer film and a glass plate is too high, laminated glass fails to absorb the impact at a collision when a human body or the like collides with the laminated glass. As such, in order to weaken the adhesive force between an interlayer film and a glass plate, a compound containing magnesium is used.

However, even when a compound containing magnesium is added in order to weaken the adhesive force, the adhesive force sometimes fails to be lowered. Furthermore, there is a problem that the adhesive force of an interlayer film to a glass plate varies depending on the water content in the interlayer film.

On the other hand, when magnesium is excessively added, there is a problem that the moisture resistance of laminated glass is lowered.

The present inventors have found that a compound containing magnesium in an interlayer film moves through the interlayer film during an autoclaving process and the like at the time of producing laminated glass. The present inventors assumed that the adhesive force between an interlayer film and a lamination glass member can be adjusted by making a compound containing magnesium exist at the interface between the interlayer film and the lamination glass member and thought that the distribution of the compound containing magnesium needs to be adjusted so as to make the compound containing magnesium exist at the more surface side than the midpoint in the thickness direction of the interlayer film. However, the present inventors have found that, rather, reducing the existing amount of the compound containing magnesium existing on the surface of the interlayer film is effective.

Based on the findings, with regard to the constitution enabling laminated glass to exhibit high moisture resistance and moderate adhesive force, the present inventors have found that an interlayer film needs only to satisfy the above-mentioned Number <NUM> requirement.

Furthermore, in the present invention, even when the interlayer film is changed in its water content, moderate adhesive force can be maintained.

The interlayer film needs only to satisfy the above-mentioned Number <NUM> requirement on the first surface thereof. High moisture resistance and moderate adhesive force are attributed to the first surface and exhibited on the first surface side.

With the use of TOF-SIMS, a portion on a second surface of the interlayer film according to the present invention is measured for Ratio<NUM> of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin.

Next, a sputtering and measurement process in which the second surface portion measured for Ratio<NUM> is subjected to sputtering one time and measured for Ratio of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin with the use of TOF-SIMS is performed m times. m Ratioms of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to m-th sputtering and measurement processes are collected.

For example, when the sputtering and measurement process is performed <NUM> times, <NUM> Ratios of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to 150th sputtering and measurement processes are collected. For example, in the second sputtering and measurement process, the second surface portion measured for Ratio<NUM> is subjected to sputtering and measurement. In the third sputtering and measurement process, the second surface portion measured for Ratio<NUM> is subjected to sputtering and measurement.

In the interlayer film according to the present invention, it is preferred that, (Number <NUM>' requirement) among five average values of an average value<NUM> ≤ m ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ m ≤ <NUM> measured within a range of <NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ m ≤ <NUM> measured within a range of <NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ m ≤ <NUM> measured within a range of <NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ m ≤ <NUM> measured within a range of <NUM> ≤ m ≤ <NUM>, and an average value<NUM> ≤ m ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ m ≤ <NUM> measured within a range of <NUM> ≤ m ≤ <NUM>, the average value indicating the smallest value be the average value<NUM> ≤ m ≤ <NUM> or the average value<NUM> ≤ m ≤ <NUM> and the average value indicating the largest value be the average value<NUM> ≤ m ≤ <NUM>, the average value<NUM> ≤ m ≤ <NUM>, or the average value<NUM> ≤ m ≤ <NUM>.

By making the interlayer film satisfy the Number <NUM> requirement and satisfy the Number <NUM>' requirement on both surface sides thereof, high moisture resistance and moderate adhesive force are attributed to both of the first surface and the second surface and exhibited on both of the first surface side and the second surface side.

From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average Value<NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM>, the average value indicating the smallest value is preferably the average value<NUM> ≤ n ≤ <NUM>. From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, and an average value<NUM> ≤ m ≤ <NUM>, the average value indicating the smallest value is preferably the average value<NUM> ≤ m ≤ <NUM>.

From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM>, the average value indicating the largest value is preferably the average value<NUM> ≤ n ≤ <NUM> or the average value<NUM> ≤ n ≤ <NUM> and more preferably the average value<NUM> ≤ n ≤ <NUM>. From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, and an average value<NUM> ≤ m ≤ <NUM>, the average value indicating the largest value is preferably the average value<NUM> ≤ m ≤ <NUM> or the average value<NUM> ≤ m ≤ <NUM> and more preferably the average value<NUM> ≤ m ≤ <NUM>.

From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM>, the smallest value is preferably <NUM> or more, more preferably <NUM> or more, further preferably <NUM> or more, preferably <NUM> or less, more preferably <NUM> or less, further preferably <NUM> or less, especially preferably <NUM> or less, and most preferably <NUM> or less.

From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM>, the largest value is preferably <NUM> or more, more preferably <NUM> or more, further preferably <NUM> or more, preferably <NUM> or less, and more preferably <NUM> or less.

From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, and an average value<NUM> ≤ m ≤ <NUM>, the smallest value is preferably <NUM> or more, more preferably <NUM> or more, further preferably <NUM> or more, preferably <NUM> or less, more preferably <NUM> or less, further preferably <NUM> or less, especially preferably <NUM> or less, and most preferably <NUM> or less.

From the viewpoints of further enhancing the moisture resistance and effectively adjusting the adhesive force within a moderate range, among five average values of an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, an average value<NUM> ≤ m ≤ <NUM>, and an average value<NUM> ≤ m ≤ <NUM>, the largest value is preferably <NUM> or more, more preferably <NUM> or more, further preferably <NUM> or more, preferably <NUM> or less, and more preferably <NUM> or less.

Examples of a method of making the interlayer film satisfy the Number <NUM> requirement or the Number <NUM>' requirement include a method of washing an extrusion-molded interlayer film, a method of bringing an interlayer film extruded from a mold into contact with a cooling roll immediately to rapidly lower the surface temperature, and the like. In a method of washing an extrusion-molded interlayer film, it is preferred that the interlayer film be washed several times. In a method of washing an extrusion-molded interlayer film, cold water, hot water, water vapor, and the like can be utilized to appropriately perform the washing.

Specifically, measurement and analysis by TOF-SIMS (time-of-flight secondary ion mass spectrometry) are performed as follows.

Using "TOF-SIMS <NUM>" available from ION-TOF GmbH, the surface of an interlayer film is measured by a dual beam method in which the Bi<NUM>++ ion gun is adopted as a primary ion source for measurement and the C<NUM>+ ion (voltage: <NUM> keV, current <NUM> nA) is adopted as a sputter source for sputtering. The sputtering area is set to <NUM> × <NUM>. The sputter analysis area is set to <NUM> × <NUM>. Since sputtering and measurement are alternately repeated, distribution of respective ions in the depth direction from a surface can be evaluated.

The number of sputter times is taken as abscissa, the intensity ratio of the secondary ion in every sputtering is taken as ordinate, and measured values are plotted. The relationship between the number of sputtering times and the secondary ion intensity is graphically shown to obtain a depth profile.

Specifically, measurement conditions for TOF-SIMS are as follows.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

<FIG> shows an interlayer film for laminated glass in accordance with a first embodiment of the present invention schematically represented as a sectional view.

An interlayer film <NUM> shown in <FIG> is a multilayered interlayer film having a two or more-layer structure. The interlayer film <NUM> is used for obtaining laminated glass. The interlayer film <NUM> is an interlayer film for laminated glass. The interlayer film <NUM> is provided with a first layer <NUM>, a second layer <NUM>, and a third layer <NUM>. The second layer <NUM> is arranged on a first surface 1a of the first layer <NUM> to be layered thereon. The third layer <NUM> is arranged on a second surface 1b opposite to the first surface 1a of the first layer <NUM> to be layered thereon. The first layer <NUM> is an intermediate layer. Each of the second layer <NUM> and the third layer <NUM> is a protective layer and is a surface layer in the present embodiment. The second layer <NUM> is a surface layer positioned at the first surface 11a side of the interlayer film <NUM>. The second layer <NUM> is a surface layer positioned at the second surface 11b side of the interlayer film <NUM>.

The first layer <NUM> is arranged between the second layer <NUM> and the third layer <NUM> to be sandwiched therebetween. Accordingly, the interlayer film <NUM> has a multilayer structure (a second layer <NUM>/a first layer <NUM>/a third layer <NUM>) in which the second layer <NUM>, the first layer <NUM>, and the third layer <NUM> are layered in this order.

In this connection, other layers may be arranged between the second layer <NUM> and the first layer <NUM> and between the first layer <NUM> and the third layer <NUM>, respectively. It is preferred that each of the second layer <NUM> and the third layer <NUM> be directly layered on the first layer <NUM>. Examples of another layer include a layer containing polyethylene terephthalate and the like.

<FIG> shows an interlayer film for laminated glass in accordance with a second embodiment of the present invention schematically represented as a sectional view.

The interlayer film 11A shown in <FIG> is a single-layered interlayer film having a one-layer structure. The interlayer film 11A is singly constituted by a first layer. The interlayer film 11A is used for obtaining laminated glass. The interlayer film 11A is an interlayer film for laminated glass. The interlayer film 11A is a surface layer positioned at the first surface 11a side of the interlayer film 11A and is also a surface layer positioned at the second surface 11b side of the interlayer film 11A.

Hereinafter, the details of the first layer, the second layer and the third layer which constitute the interlayer film according to the present invention, and the details of each ingredient contained in the first layer, the second layer and the third layer will be described.

The interlayer contains a thermoplastic resin containing a polyvinyl acetal resin. The first layer preferably contains a thermoplastic resin (hereinafter, sometimes described as a thermoplastic resin (<NUM>)) and preferably contains a polyvinyl acetal resin (hereinafter, sometimes described as a polyvinyl acetal resin (<NUM>)) as the thermoplastic resin (<NUM>). The second layer preferably contains a thermoplastic resin (hereinafter, sometimes described as a thermoplastic resin (<NUM>)) and preferably contains a polyvinyl acetal resin (hereinafter, sometimes described as a polyvinyl acetal resin (<NUM>)) as the thermoplastic resin (<NUM>). The third layer preferably contains a thermoplastic resin (hereinafter, sometimes described as a thermoplastic resin (<NUM>)) and preferably contains a polyvinyl acetal resin (hereinafter, sometimes described as a polyvinyl acetal resin (<NUM>)) as the thermoplastic resin (<NUM>). Although the polyvinyl acetal resin (<NUM>), the polyvinyl acetal resin (<NUM>), and the polyvinyl acetal resin (<NUM>) may be the same as or different from one another, it is preferred that the polyvinyl acetal resin (<NUM>) be different from the polyvinyl acetal resin (<NUM>) and the polyvinyl acetal resin (<NUM>) because the sound insulating properties are further heightened. The thermoplastic resin (<NUM>) and the thermoplastic resin (<NUM>) may be the same as or different from each other. One kind of each of the polyvinyl acetal resin (<NUM>), the polyvinyl acetal resin (<NUM>), and the polyvinyl acetal resin (<NUM>) may be used alone, and two or more kinds thereof may be used in combination. One kind of each of the thermoplastic resin (<NUM>) and the thermoplastic resin (<NUM>) may be used alone, and two or more kinds thereof may be used in combination.

Examples of the thermoplastic resin include a polyvinyl acetal resin, an ethylene-vinyl acetate copolymer resin, an ethylene-acrylic acid copolymer resin, a polyurethane resin, a polyvinyl alcohol resin, and the like. Thermoplastic resins other than these may be used.

For example, the polyvinyl acetal resin can be produced by acetalizing polyvinyl alcohol with an aldehyde. It is preferred that the polyvinyl acetal resin be an acetalized product of polyvinyl alcohol. For example, the polyvinyl alcohol can be obtained by saponifying polyvinyl acetate. The saponification degree of the polyvinyl alcohol generally falls within the range of <NUM> to <NUM>% by mole.

The average polymerization degree of the polyvinyl alcohol (PVA) is preferably <NUM> or more, more preferably <NUM> or more, even more preferably <NUM> or more, further preferably <NUM> or more, especially preferably <NUM> or more, most preferably <NUM> or more, preferably <NUM> or less, more preferably <NUM> or less and further preferably <NUM> or less. When the average polymerization degree is the above lower limit or more, the penetration resistance of laminated glass is further enhanced. When the average polymerization degree is the above upper limit or less, formation of an interlayer film is facilitated.

The average polymerization degree of the polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing methods for polyvinyl alcohol".

It is preferred that the number of carbon atoms of the acetal group in the polyvinyl acetal resin lie within the range of <NUM> to <NUM>, and it is preferred that the number of carbon atoms of the acetal group be <NUM> or <NUM>.

In general, as the aldehyde, an aldehyde with <NUM> to <NUM> carbon atoms is suitably used. Examples of the aldehyde with <NUM> to <NUM> carbon atoms include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, <NUM>-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, benzaldehyde, and the like. Of these, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-hexylaldehyde or n-valeraldehyde is preferred, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde or n-valeraldehyde is more preferred, and n-butyraldehyde or n-valeraldehyde is further preferred. One kind of the aldehyde may be used alone, and two or more kinds thereof may be used in combination.

The content of the hydroxyl group (the amount of hydroxyl groups) of the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably less than <NUM>% by mole, and further preferably <NUM>% by mole or less. When the content of the hydroxyl group is the above lower limit or more, the adhesive force of the interlayer film is further heightened. In particular, when the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) is <NUM>% by mole or more, the resin is high in reaction efficiency and is excellent in productivity, and moreover, when less than <NUM>% by mole, the sound insulating properties of laminated glass are further heightened. Moreover, when the content of the hydroxyl group is the above upper limit or less, the flexibility of the interlayer film is enhanced and the handling of the interlayer film is facilitated.

In the case where the interlayer film is single-layered or the case where the first layer is an outermost layer of the interlayer film, the content of the hydroxyl group (the amount of hydroxyl groups) of the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less, and especially preferably <NUM>% by mole or less. When the content of the hydroxyl group is the above lower limit or more, the mechanical strength of the interlayer film is further heightened. In particular, when the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) is <NUM>% by mole or more, the resin is high in reaction efficiency and is excellent in productivity. Moreover, when the content of the hydroxyl group is the above upper limit or less, the flexibility of the interlayer film is enhanced and the handling of the interlayer film is facilitated.

The content of the hydroxyl group of each of the polyvinyl acetal resin (<NUM>) and the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, even more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, and further preferably <NUM>% by mole or less. When the content of the hydroxyl group is the above lower limit or more, the adhesive force of the interlayer film is further heightened. Moreover, when the content of the hydroxyl group is the above upper limit or less, the flexibility of the interlayer film is enhanced and the handling of the interlayer film is facilitated.

From the viewpoint of further heightening the sound insulating properties, it is preferred that the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) be lower than the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>). From the viewpoint of still further heightening the sound insulating properties, the absolute value of the difference between the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) and the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, and most preferably <NUM>% by mole or more. The absolute value of the difference between the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) and the content of the hydroxyl group of the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or less.

The content of the hydroxyl group of the polyvinyl acetal resin is a mole fraction, represented in percentage, obtained by dividing the amount of ethylene groups to which the hydroxyl group is bonded by the total amount of ethylene groups in the main chain. For example, the amount of ethylene groups to which the hydroxyl group is bonded can be measured in accordance with JIS K6728 "Testing methods for polyvinyl butyral".

The acetylation degree (the amount of acetyl groups) of the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, even more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, and further preferably <NUM>% by mole or less. When the acetylation degree is the above lower limit or more, the compatibility between the polyvinyl acetal resin and a plasticizer is heightened. When the acetylation degree is the above upper limit or less, with regard to the interlayer film and laminated glass, the moisture resistance thereof is enhanced. In particular, when the acetylation degree of the polyvinyl acetal resin (<NUM>) is <NUM>% by mole or more and <NUM>% by mole or less, the resulting laminated glass is excellent in penetration resistance.

In the case where the interlayer film is single-layered or the case where the first layer is an outermost layer of the interlayer film, the acetylation degree (the amount of acetyl groups) of the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, even more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, and further preferably <NUM>% by mole or less. When the acetylation degree is the above lower limit or more, the compatibility between the polyvinyl acetal resin and a plasticizer is heightened. When the acetylation degree is the above upper limit or less, with regard to the interlayer film and laminated glass, the moisture resistance thereof is enhanced.

The acetylation degree of each of the polyvinyl acetal resin (<NUM>) and the polyvinyl acetal resin (<NUM>) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, and more preferably <NUM>% by mole or less. When the acetylation degree is the above lower limit or more, the compatibility between the polyvinyl acetal resin and a plasticizer is heightened. When the acetylation degree is the above upper limit or less, with regard to the interlayer film and laminated glass, the moisture resistance thereof is enhanced.

The acetylation degree is a mole fraction, represented in percentage, obtained by dividing the amount of ethylene groups to which the acetyl group is bonded by the total amount of ethylene groups in the main chain. For example, the amount of ethylene groups to which the acetyl group is bonded can be measured in accordance with JIS K6728 "Testing methods for polyvinyl butyral".

The acetalization degree of the polyvinyl acetal resin (<NUM>) (the butyralization degree in the case of a polyvinyl butyral resin) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less and further preferably <NUM>% by mole or less. When the acetalization degree is the above lower limit or more, the compatibility between the polyvinyl acetal resin and a plasticizer is heightened. When the acetalization degree is the above upper limit or less, the reaction time required for producing the polyvinyl acetal resin is shortened.

In the case where the interlayer film is single-layered or the case where the first layer is an outermost layer of the interlayer film, the acetalization degree of the polyvinyl acetal resin (<NUM>) (the butyralization degree in the case of a polyvinyl butyral resin) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, and further preferably <NUM>% by mole or less. When the acetalization degree is the above lower limit or more, the compatibility between the polyvinyl acetal resin and a plasticizer is heightened. When the acetalization degree is the above upper limit or less, the reaction time required for producing the polyvinyl acetal resin is shortened.

The acetalization degree of each of the polyvinyl acetal resin (<NUM>) and the polyvinyl acetal resin (<NUM>) (the butyralization degree in the case of a polyvinyl butyral resin) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, preferably <NUM>% by mole or less and more preferably <NUM>% by mole or less. When the acetalization degree is the above lower limit or more, the compatibility between the polyvinyl acetal resin and a plasticizer is heightened. When the acetalization degree is the above upper limit or less, the reaction time required for producing the polyvinyl acetal resin is shortened.

The acetalization degree is a mole fraction, represented in percentage, obtained by dividing a value obtained by subtracting the amount of ethylene groups to which the hydroxyl group is bonded and the amount of ethylene groups to which the acetyl group is bonded from the total amount of ethylene groups in the main chain by the total amount of ethylene groups in the main chain.

In this connection, it is preferred that the content of the hydroxyl group (the amount of hydroxyl groups), the acetalization degree (the butyralization degree) and the acetylation degree be calculated from the results measured by a method in accordance with JIS K6728 "Testing methods for polyvinyl butyral". In this context, a method in accordance with ASTM D1396-<NUM> may be used. When the polyvinyl acetal resin is a polyvinyl butyral resin, the content of the hydroxyl group (the amount of hydroxyl groups), the acetalization degree (the butyralization degree) and the acetylation degree can be calculated from the results measured by a method in accordance with JIS K6728 "Testing methods for polyvinyl butyral".

From the viewpoint of further improving the penetration resistance of laminated glass, it is preferred that the polyvinyl acetal resin (<NUM>) be a polyvinyl acetal resin (A) with an acetylation degree (a) of less than <NUM>% by mole and an acetalization degree (a) of <NUM>% by mole or more or a polyvinyl acetal resin (B) with an acetylation degree (b) of <NUM>% by mole or more. Each of the polyvinyl acetal resin (<NUM>) and the polyvinyl acetal resin (<NUM>) may be the polyvinyl acetal resin (A) and may be the polyvinyl acetal resin (B).

The acetylation degree (a) of the polyvinyl acetal resin (A) is less than <NUM>% by mole, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less, especially preferably <NUM>% by mole or less, preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more and especially preferably <NUM>% by mole or more. When the acetylation degree (a) is <NUM>% by mole or more and less than <NUM>% by mole, the transfer of a plasticizer can be easily controlled and the sound insulating properties of laminated glass are further heightened.

The acetalization degree (a) of the polyvinyl acetal resin (A) is <NUM>% by mole or more, preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less and especially preferably <NUM>% by mole or less. When the acetalization degree (a) is the above lower limit or more, the sound insulating properties of laminated glass are further heightened. When the acetalization degree (a) is the above upper limit or less, the reaction time required for producing the polyvinyl acetal resin (A) can be shortened.

The content (a) of the hydroxyl group of the polyvinyl acetal resin (A) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, most preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less and especially preferably <NUM>% by mole or less. When the content (a) of the hydroxyl group is the above lower limit or more, the adhesive force of the interlayer film is further heightened. When the content (a) of the hydroxyl group is the above upper limit or less, the sound insulating properties of laminated glass are further heightened.

The acetylation degree (b) of the polyvinyl acetal resin (B) is <NUM>% by mole or more, preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less and especially preferably <NUM>% by mole or less. When the acetylation degree (b) is the above lower limit or more, the sound insulating properties of laminated glass are further heightened. When the acetylation degree (b) is the above upper limit or less, the reaction time required for producing the polyvinyl acetal resin (B) can be shortened.

The acetalization degree (b) of the polyvinyl acetal resin (B) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less and especially preferably <NUM>% by mole or less. When the acetalization degree (b) is the above lower limit or more, the sound insulating properties of laminated glass are further heightened. When the acetalization degree (b) is the above upper limit or less, the reaction time required for producing the polyvinyl acetal resin (B) can be shortened.

The content (b) of the hydroxyl group of the polyvinyl acetal resin (B) is preferably <NUM>% by mole or more, more preferably <NUM>% by mole or more, further preferably <NUM>% by mole or more, especially preferably <NUM>% by mole or more, most preferably <NUM>% by mole or more, preferably <NUM>% by mole or less, more preferably <NUM>% by mole or less, further preferably <NUM>% by mole or less and especially preferably <NUM>% by mole or less. When the content (b) of the hydroxyl group is the above lower limit or more, the adhesive force of the interlayer film is further heightened. When the content (b) of the hydroxyl group is the above upper limit or less, the sound insulating properties of laminated glass are further heightened.

It is preferred that each of the polyvinyl acetal resin (A) and the polyvinyl acetal resin (B) be a polyvinyl butyral resin.

It is preferred that the first layer (including a single-layered interlayer film) contain a plasticizer (hereinafter, sometimes described as a plasticizer (<NUM>)). It is preferred that the second layer contain a plasticizer (hereinafter, sometimes described as a plasticizer (<NUM>)). It is preferred that the third layer contain a plasticizer (hereinafter, sometimes described as a plasticizer (<NUM>)). By the use of the plasticizer or by using a polyvinyl acetal resin and a plasticizer together, the adhesive force of a layer containing the polyvinyl acetal resin and the plasticizer to a lamination glass member or another layer is moderately heightened. The plasticizer is not particularly limited. The plasticizer (<NUM>), the plasticizer (<NUM>) and the plasticizer (<NUM>) may be the same as or different from one another. One kind of each of the plasticizer (<NUM>), the plasticizer (<NUM>) and the plasticizer (<NUM>) may be used alone, and two or more kinds thereof may be used in combination.

Examples of the plasticizer include organic ester plasticizers such as a monobasic organic acid ester and a polybasic organic acid ester, organic phosphate plasticizers such as an organic phosphate plasticizer and an organic phosphite plasticizer, and the like. Of these, organic ester plasticizers are preferred. It is preferred that the plasticizer be a liquid plasticizer.

Examples of the monobasic organic acid ester include a glycol ester obtained by the reaction of a glycol with a monobasic organic acid, and the like. Examples of the glycol include triethylene glycol, tetraethylene glycol, tripropylene glycol, and the like. Examples of the monobasic organic acid include butyric acid, isobutyric acid, caproic acid, <NUM>-ethylbutyric acid, heptanoic acid, n-octylic acid, <NUM>-ethylhexanoic acid, n-nonylic acid, decanoic acid, and the like.

Examples of the polybasic organic acid ester include an ester compound of a polybasic organic acid and an alcohol having a linear or branched structure of <NUM> to <NUM> carbon atoms. Examples of the polybasic organic acid include adipic acid, sebacic acid, azelaic acid, and the like.

Examples of the organic ester plasticizer include triethylene glycol di-<NUM>-ethylpropanoate, triethylene glycol di-<NUM>-ethylbutyrate, triethylene glycol di-<NUM>-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-<NUM>-ethylbutyrate, <NUM>,<NUM>-propylene glycol di-<NUM>-ethylbutyrate, <NUM>,<NUM>-butylene glycol di-<NUM>-ethylbutyrate, diethylene glycol di-<NUM>-ethylbutyrate, diethylene glycol di-<NUM>-ethylhexanoate, dipropylene glycol di-<NUM>-ethylbutyrate, triethylene glycol di-<NUM>-ethylpentanoate, tetraethylene glycol di-<NUM>-ethylbutyrate, diethylene glycol dicaprylate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, a mixture of heptyl adipate and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptyl nonyl adipate, dibutyl sebacate, oil-modified sebacic alkyds, a mixture of a phosphoric acid ester and an adipic acid ester, and the like. Organic ester plasticizers other than these may be used. Other adipic acid esters other than the above-described adipic acid esters may be used.

Examples of the organic phosphate plasticizer include tributoxyethyl phosphate, isodecyl phenyl phosphate, triisopropyl phosphate, and the like.

It is preferred that the plasticizer be a diester plasticizer represented by the following formula (<NUM>).

In the foregoing formula (<NUM>), R1 and R2 each represent an organic group with <NUM> to <NUM> carbon atoms, R3 represents an ethylene group, an isopropylene group or an n-propylene group, and p represents an integer of <NUM> to <NUM>. It is preferred that R1 and R2 in the foregoing formula (<NUM>) each be an organic group with <NUM> to <NUM> carbon atoms, and it is more preferred that R1 and R2 each be an organic group with <NUM> to <NUM> carbon atoms.

It is preferred that the plasticizer include triethylene glycol di-<NUM>-ethylhexanoate (3GO), triethylene glycol di-<NUM>-ethylbutyrate (3GH) or triethylene glycol di-<NUM>-ethylpropanoate, it is more preferred that the plasticizer include triethylene glycol di-<NUM>-ethylhexanoate or triethylene glycol di-<NUM>-ethylbutyrate, and it is further preferred that the plasticizer include triethylene glycol di-<NUM>-ethylhexanoate.

Each of the content of the plasticizer (<NUM>) (hereinafter, sometimes described as the content (<NUM>)) relative to <NUM> parts by weight of the thermoplastic resin (<NUM>) (<NUM> parts by weight of a polyvinyl acetal resin (<NUM>) when the thermoplastic resin (<NUM>) is the polyvinyl acetal resin (<NUM>)) and the content of the plasticizer (<NUM>) (hereinafter, sometimes described as the content (<NUM>)) relative to <NUM> parts by weight of the thermoplastic resin (<NUM>) (<NUM> parts by weight of a polyvinyl acetal resin (<NUM>) when the thermoplastic resin (<NUM>) is the polyvinyl acetal resin (<NUM>)) is preferably <NUM> parts by weight or more, more preferably <NUM> parts by weight or more, preferably <NUM> parts by weight or less, more preferably <NUM> parts by weight or less, further preferably <NUM> parts by weight or less, especially preferably <NUM> parts by weight or less, and most preferably <NUM> parts by weight or less. When the content (<NUM>) and the content (<NUM>) are the above lower limit or more, the flexibility of the interlayer film is enhanced and the handling of the interlayer film is facilitated. When the content (<NUM>) and the content (<NUM>) are the above upper limit or less, the penetration resistance of laminated glass is further enhanced.

The content of the plasticizer (<NUM>) (hereinafter, sometimes described as the content (<NUM>)) relative to <NUM> parts by weight of the thermoplastic resin (<NUM>) (<NUM> parts by weight of a polyvinyl acetal resin (<NUM>) when the thermoplastic resin (<NUM>) is the polyvinyl acetal resin (<NUM>)) is preferably <NUM> parts by weight or more, more preferably <NUM> parts by weight or more, further preferably <NUM> parts by weight or more, preferably <NUM> parts by weight or less, more preferably <NUM> parts by weight or less, and further preferably <NUM> parts by weight or less. When the content (<NUM>) is the above lower limit or more, the flexibility of the interlayer film is enhanced and the handling of the interlayer film is facilitated. When the content (<NUM>) is the above upper limit or less, the penetration resistance of laminated glass is further enhanced.

In the case where the interlayer film is single-layered or the case where the first layer is an outermost layer of the interlayer film, the content of the plasticizer (<NUM>) (hereinafter, sometimes described as the content (<NUM>)) relative to <NUM> parts by weight of the thermoplastic resin (<NUM>) (<NUM> parts by weight of a polyvinyl acetal resin (<NUM>) when the thermoplastic resin (<NUM>) is the polyvinyl acetal resin (<NUM>)) is preferably <NUM> parts by weight or more, more preferably <NUM> parts by weight or more, further preferably <NUM> parts by weight or more, especially preferably <NUM> parts by weight or more, preferably <NUM> parts by weight or less, more preferably <NUM> parts by weight or less, and further preferably <NUM> parts by weight or less. When the content (<NUM>) is the above lower limit or more, the flexibility of the interlayer film is enhanced and the handling of the interlayer film is facilitated. When the content (<NUM>) is the above upper limit or less, the penetration resistance of laminated glass is further enhanced.

For the purpose of heightening the sound insulating properties of laminated glass, it is preferred that the content (<NUM>) be larger than the content (<NUM>) and it is preferred that the content (<NUM>) be larger than the content (<NUM>). In particular, from the viewpoint of further heightening the sound insulating properties of laminated glass, each of the absolute value of the difference between the content (<NUM>) and the content (<NUM>) and the absolute value of the difference between the content (<NUM>) and the content (<NUM>) is preferably <NUM> parts by weight or more, more preferably <NUM> parts by weight or more, and further preferably <NUM> parts by weight or more. Each of the absolute value of the difference between the content (<NUM>) and the content (<NUM>) and the absolute value of the difference between the content (<NUM>) and the content (<NUM>) is preferably <NUM> parts by weight or less, more preferably <NUM> parts by weight or less, and further preferably <NUM> parts by weight or less.

It is preferred that the interlayer film include a heat shielding compound. It is preferred that the first layer contain a heat shielding compound. It is preferred that the second layer contain a heat shielding compound. It is preferred that the third layer contain a heat shielding compound. One kind of the heat shielding compound may be used alone, and two or more kinds thereof may be used in combination.

It is preferred that the interlayer film include at least one kind of Ingredient X among a phthalocyanine compound, a naphthalocyanine compound and an anthracyanine compound. It is preferred that the first layer contain the Ingredient X. It is preferred that the second layer contain the Ingredient X. It is preferred that the third layer contain the Ingredient X. The Ingredient X is a heat shielding compound. One kind of the Ingredient X may be used alone, and two or more kinds thereof may be used in combination.

The Ingredient X is not particularly limited. As the Ingredient X, conventionally known phthalocyanine compound, naphthalocyanine compound and anthracyanine compound can be used.

With regard to the interlayer film and laminated glass, from the viewpoint of further enhancing the heat shielding properties thereof, it is preferred that the Ingredient X be at least one kind selected from the group consisting of phthalocyanine, a derivative of phthalocyanine, naphthalocyanine and a derivative of naphthalocyanine, and it is more preferred that the Ingredient X be at least one kind among phthalocyanine and a derivative of phthalocyanine.

From the viewpoints of effectively enhancing the heat shielding properties and maintaining the visible light transmittance at a higher level over a long period of time, it is preferred that the Ingredient X contain vanadium atoms or copper atoms. It is preferred that the Ingredient X contain vanadium atoms and it is also preferred that the Ingredient X contain copper atoms. It is more preferred that the Ingredient X be at least one kind among phthalocyanine containing vanadium atoms or copper atoms and a derivative of phthalocyanine containing vanadium atoms or copper atoms. With regard to the interlayer film and laminated glass, from the viewpoint of still further enhancing the heat shielding properties thereof, it is preferred that the Ingredient X have a structural unit in which an oxygen atom is bonded to a vanadium atom.

In <NUM>% by weight of a layer containing the Ingredient X (a first layer, a second layer or a third layer), the content of the Ingredient X is preferably <NUM>% by weight or more, more preferably <NUM>% by weight or more, further preferably <NUM>% by weight or more, especially preferably <NUM>% by weight or more, preferably <NUM>% by weight or less, more preferably <NUM>% by weight or less, further preferably <NUM>% by weight or less and especially preferably <NUM>% by weight or less. When the content of the Ingredient X is the above lower limit or more and the above upper limit or less, the heat shielding properties are sufficiently enhanced and the visible light transmittance is sufficiently heightened. For example, it is possible to make the visible light transmittance <NUM>% or more.

It is preferred that the interlayer film include heat shielding particles. It is preferred that the first layer contain the heat shielding particles. It is preferred that the second layer contain the heat shielding particles. It is preferred that the third layer contain the heat shielding particles. The heat shielding particle is of a heat shielding compound. By the use of heat shielding particles, infrared rays (heat rays) can be effectively cut off. One kind of the heat shielding particles may be used alone, and two or more kinds thereof may be used in combination.

From the viewpoint of further heightening the heat shielding properties of laminated glass, it is more preferred that the heat shielding particles be metal oxide particles. It is preferred that the heat shielding particle be a particle (a metal oxide particle) formed from an oxide of a metal.

The energy amount of an infrared ray with a wavelength of <NUM> or longer which is longer than that of visible light is small as compared with an ultraviolet ray. However, the thermal action of infrared rays is large, and when infrared rays are absorbed into a substance, heat is released from the substance. As such, infrared rays are generally called heat rays. By the use of the heat shielding particles, infrared rays (heat rays) can be effectively cut off. In this connection, the heat shielding particle means a particle capable of absorbing infrared rays.

Specific examples of the heat shielding particles include metal oxide particles such as aluminum-doped tin oxide particles, indium-doped tin oxide particles, antimony-doped tin oxide particles (ATO particles), gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), niobium-doped titanium oxide particles, sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, tin-doped indium oxide particles (ITO particles), tin-doped zinc oxide particles and silicondoped zinc oxide particles, lanthanum hexaboride (LaB<NUM>) particles, and the like. Heat shielding particles other than these may be used. Of these, since the heat ray shielding function is high, preferred are metal oxide particles, more preferred are ATO particles, GZO particles, IZO particles, ITO particles or tungsten oxide particles, and especially preferred are ITO particles or tungsten oxide particles. In particular, since the heat ray shielding function is high and the particles are readily available, preferred are tin-doped indium oxide particles (ITO particles), and also preferred are tungsten oxide particles.

With regard to the interlayer film and laminated glass, from the viewpoint of further enhancing the heat shielding properties thereof, it is preferred that the tungsten oxide particles be metal-doped tungsten oxide particles. Examples of the "tungsten oxide particles" include metal-doped tungsten oxide particles. Specifically, examples of the metal-doped tungsten oxide particles include sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, and the like.

With regard to the interlayer film and laminated glass, from the viewpoint of further enhancing the heat shielding properties thereof, cesium-doped tungsten oxide particles are especially preferred. With regard to the interlayer film and laminated glass, from the viewpoint of still further enhancing the heat shielding properties thereof, it is preferred that the cesium-doped tungsten oxide particles be tungsten oxide particles represented by the formula: Cs<NUM>WO<NUM>.

The average particle diameter of the heat shielding particles is preferably <NUM> or more, more preferably <NUM> or more, preferably <NUM> or less and more preferably <NUM> or less. When the average particle diameter is the above lower limit or more, the heat ray shielding properties are sufficiently heightened. When the average particle diameter is the above upper limit or less, the dispersibility of heat shielding particles is enhanced.

The "average particle diameter" refers to the volume average particle diameter. The average particle diameter can be measured using a particle size distribution measuring apparatus ("UPA-EX150" available from NIKKISO CO. ), or the like.

In <NUM>% by weight of a layer containing the heat shielding particles (a first layer, a second layer or a third layer), each content of the heat shielding particles is preferably <NUM>% by weight or more, more preferably <NUM>% by weight or more, further preferably <NUM>% by weight or more, especially preferably <NUM>% by weight or more, preferably <NUM>% by weight or less, more preferably <NUM>% by weight or less, further preferably <NUM>% by weight or less, especially preferably <NUM>% by weight or less and most preferably <NUM>% by weight or less. When the content of the heat shielding particles is the above lower limit or more and the above upper limit or less, the heat shielding properties are sufficiently enhanced and the visible light transmittance is sufficiently heightened.

The interlayer film, a surface layer positioned at the first surface side of the interlayer film, and a surface layer positioned at the second surface side of the interlayer film contain magnesium. It is preferred that the surface layer contain a compound containing magnesium and it is preferred that the compound containing magnesium be a magnesium salt (hereinafter, sometimes described as Metal salt M). By making the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film contain magnesium, the adhesive force can be moderately adjusted. It is preferred that the interlayer film include at least one kind of metal salt among an alkali metal salt and an alkaline earth metal salt other than the Metal salt M. It is preferred that the first layer contain the Metal salt M. It is preferred that the second layer contain the Metal salt M. It is preferred that the third layer contain the Metal salt M. By the use of the Metal salt M, controlling the adhesivity between the interlayer film and a lamination glass member or the adhesivity between respective layers in the interlayer film is facilitated. One kind of the Metal salt M may be used alone and two or more kinds thereof may be used in combination.

It is further preferred that the Metal salt M be a magnesium carboxylate with <NUM> to <NUM> carbon atoms. Although the magnesium carboxylate with <NUM> to <NUM> carbon atoms is not particularly limited, examples thereof include magnesium acetate, magnesium propionate, magnesium <NUM>-ethylbutyrate, magnesium <NUM>-ethylhexanoate, and the like.

It is preferred that a potassium salt as at least one kind of metal salt among an alkali metal salt and an alkaline earth metal salt be contained therein and it is more preferred that a potassium carboxylate with <NUM> to <NUM> carbon atoms be contained therein. Although the potassium carboxylate with <NUM> to <NUM> carbon atoms is not particularly limited, examples thereof include potassium acetate, potassium propionate, potassium <NUM>-ethylbutanoate, potassium <NUM>-ethylhexanoate, and the like.

From the viewpoint of effectively enhancing the moisture resistance and the penetration resistance, it is preferred that a compound containing magnesium be contained in the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film and it is more preferred that magnesium acetate be contained therein.

From the viewpoint of effectively enhancing the moisture resistance and the penetration resistance, it is preferred that potassium be contained in the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film. From the viewpoint of effectively enhancing the moisture resistance and the penetration resistance, it is preferred that a compound containing potassium be contained in the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film.

From the viewpoint of effectively enhancing the moisture resistance and the penetration resistance, it is preferred that magnesium and potassium be contained in the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film. From the viewpoint of effectively enhancing the moisture resistance and the penetration resistance, it is preferred that a compound containing magnesium and a compound containing potassium be contained in the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film.

The total of the contents of Mg and K in a surface layer, a first layer, a second layer, or a third layer is preferably <NUM> ppm or more, more preferably <NUM> ppm or more, further preferably <NUM> ppm or more, preferably <NUM> ppm or less, more preferably <NUM> ppm or less, and further preferably <NUM> ppm or less. When the total of the contents of Mg and K is the above lower limit or more and the above upper limit or less, the adhesivity between the interlayer film and a lamination glass member or the adhesivity between respective layers in the interlayer film can be further well controlled.

The content of Mg in each of the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film is preferably <NUM> ppm or more, more preferably <NUM> ppm or more, further preferably <NUM> ppm or more, and is <NUM> ppm or less, and preferably <NUM> ppm or less.

The content of K in each of the interlayer film, the surface layer positioned at the first surface side of the interlayer film, and the surface layer positioned at the second surface side of the interlayer film is preferably <NUM> ppm or more, more preferably <NUM> ppm or more, further preferably <NUM> ppm or more, and is <NUM> ppm or less, preferably <NUM> ppm or less, and more preferably <NUM> ppm or less.

It is preferred that the interlayer film include an ultraviolet ray screening agent. It is preferred that the first layer contain an ultraviolet ray screening agent. It is preferred that the second layer contain an ultraviolet ray screening agent. It is preferred that the third layer contain an ultraviolet ray screening agent. By the use of an ultraviolet ray screening agent, even when the interlayer film and the laminated glass are used for a long period of time, the visible light transmittance becomes further difficult to be lowered. One kind of the ultraviolet ray screening agent may be used alone, and two or more kinds thereof may be used in combination.

Examples of the ultraviolet ray screening agent include an ultraviolet ray absorber. It is preferred that the ultraviolet ray screening agent be an ultraviolet ray absorber.

Examples of the ultraviolet ray screening agent include an ultraviolet ray screening agent containing a metal atom, an ultraviolet ray screening agent containing a metal oxide, an ultraviolet ray screening agent having a benzotriazole structure, an ultraviolet ray screening agent having a benzophenone structure, an ultraviolet ray screening agent having a triazine structure, an ultraviolet ray screening agent having a malonic acid ester structure, an ultraviolet ray screening agent having an oxanilide structure, an ultraviolet ray screening agent having a benzoate structure, and the like.

Examples of the ultraviolet ray screening agent containing a metal atom include platinum particles, particles in which the surface of platinum particles is coated with silica, palladium particles, particles in which the surface of palladium particles is coated with silica, and the like. It is preferred that the ultraviolet ray screening agent not be heat shielding particles.

The ultraviolet ray screening agent is preferably an ultraviolet ray screening agent having a benzotriazole structure, an ultraviolet ray screening agent having a benzophenone structure, an ultraviolet ray screening agent having a triazine structure or an ultraviolet ray screening agent having a benzoate structure, more preferably an ultraviolet ray screening agent having a benzotriazole structure or an ultraviolet ray screening agent having a benzophenone structure, and further preferably an ultraviolet ray screening agent having a benzotriazole structure.

Examples of the ultraviolet ray screening agent containing a metal oxide include zinc oxide, titanium oxide, cerium oxide, and the like. Furthermore, with regard to the ultraviolet ray screening agent containing a metal oxide, the surface thereof may be coated with any material. Examples of the coating material for the surface of the ultraviolet ray screening agent containing a metal oxide include an insulating metal oxide, a hydrolyzable organosilicon compound, a silicone compound, and the like.

Examples of the ultraviolet ray screening agent having a benzotriazole structure include ultraviolet ray screening agents having a benzotriazole structure such as <NUM>-(<NUM>'-hydroxy-<NUM>'-methylphenyl)benzotriazole ("Tinuvin P" available from BASF Japan Ltd. ), <NUM>-(<NUM>'-hydroxy-<NUM>',<NUM>'-di-t-butylphenyl)benzotriazole ("Tinuvin <NUM>" available from BASF Japan Ltd. ), <NUM>-(<NUM>'-hydroxy-<NUM>'-t-butyl-<NUM>-methylphenyl)-<NUM>-chlorobenzotriazole ("Tinuvin <NUM>" available from BASF Japan Ltd. ) and <NUM>-(<NUM>'-hydroxy-<NUM>',<NUM>'-di-amylphenyl)benzotriazole ("Tinuvin <NUM>" available from BASF Japan Ltd. It is preferred that the ultraviolet ray screening agent be an ultraviolet ray screening agent having a benzotriazole structure containing a halogen atom, and it is more preferred that the ultraviolet ray screening agent be an ultraviolet ray screening agent having a benzotriazole structure containing a chlorine atom, because those are excellent in ultraviolet ray absorbing performance.

Examples of the ultraviolet ray screening agent having a benzophenone structure include octabenzone ("Chimassorb <NUM>" available from BASF Japan Ltd. ), and the like.

Examples of the ultraviolet ray screening agent having a triazine structure include "LA-F70" available from ADEKA CORPORATION, <NUM>-(<NUM>,<NUM>-diphenyl-<NUM>,<NUM>,<NUM>-triazine-<NUM>-yl)-<NUM>-[(hexyl)oxy]-phenol ("Tinuvin 1577FF" available from BASF Japan Ltd. ), and the like.

Examples of the ultraviolet ray screening agent having a malonic acid ester structure include dimethyl(p-methoxybenzylidene)malonate, tetraethyl-<NUM>,<NUM>-(<NUM>,<NUM>-phenylenedimethylidene)bismalonate, <NUM>-(p-methoxybenzylidene)-bis(<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-pentamethyl-<NUM>-piperidinyl)malonate, and the like.

Examples of a commercial product of the ultraviolet ray screening agent having a malonic acid ester structure include Hostavin B-CAP, Hostavin PR-<NUM> and Hostavin PR-<NUM> (any of these is available from Clariant Japan K.

Examples of the ultraviolet ray screening agent having an oxanilide structure include a kind of oxalic acid diamide having a substituted aryl group and the like on the nitrogen atom such as N-(<NUM>-ethylphenyl)-N'-(<NUM>-ethoxy-<NUM>-t-butylphenyl)oxalic acid diamide, N-(<NUM>-ethylphenyl)-N'-(<NUM>-ethoxy-phenyl)oxalic acid diamide and <NUM>-ethyl-<NUM>'-ethoxy-oxanilide ("Sanduvor VSU" available from Clariant Japan K.

Examples of the ultraviolet ray screening agent having a benzoate structure include <NUM>,<NUM>-di-tert-butylphenyl-<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzoate ("Tinuvin <NUM>" available from BASF Japan Ltd. ), and the like.

From the viewpoint of further suppressing the lowering in visible light transmittance after the lapse of a certain period of time, in <NUM>% by weight of a layer containing the ultraviolet ray screening agent (a first layer, a second layer or a third layer), the content of the ultraviolet ray screening agent is preferably <NUM>% by weight or more, more preferably <NUM>% by weight or more, further preferably <NUM>% by weight or more, especially preferably <NUM>% by weight or more, preferably <NUM>% by weight or less, more preferably <NUM>% by weight or less, further preferably <NUM>% by weight or less and especially preferably <NUM>% by weight or less. In particular, by setting the content of the ultraviolet ray screening agent to be <NUM>% by weight or more in <NUM>% by weight of a layer containing the ultraviolet ray screening agent, with regard to the interlayer film and laminated glass, the lowering in visible light transmittance thereof after the lapse of a certain period of time can be significantly suppressed.

It is preferred that the interlayer film include an oxidation inhibitor. It is preferred that the first layer contain an oxidation inhibitor. It is preferred that the second layer contain an oxidation inhibitor. It is preferred that the third layer contain an oxidation inhibitor. One kind of the oxidation inhibitor may be used alone, and two or more kinds thereof may be used in combination.

Examples of the oxidation inhibitor include a phenol-based oxidation inhibitor, a sulfur-based oxidation inhibitor, a phosphorus-based oxidation inhibitor, and the like. The phenol-based oxidation inhibitor is an oxidation inhibitor having a phenol skeleton. The sulfur-based oxidation inhibitor is an oxidation inhibitor containing a sulfur atom. The phosphorus-based oxidation inhibitor is an oxidation inhibitor containing a phosphorus atom.

It is preferred that the oxidation inhibitor be a phenol-based oxidation inhibitor or a phosphorus-based oxidation inhibitor.

Examples of the phenol-based oxidation inhibitor include <NUM>,<NUM>-di-t-butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), <NUM>,<NUM>-di-t-butyl-<NUM>-ethylphenol, stearyl β-(<NUM>,<NUM>-di-t-butyl-<NUM>-hydroxyphenyl)propionate, <NUM>,<NUM>'-methylenebis-(<NUM>-methyl-<NUM>-butylphenol), <NUM>,<NUM>'-methylenebis-(<NUM>-ethyl-<NUM>-t-butylphenol), <NUM>,<NUM>'-butylidene-bis-(<NUM>-methyl-<NUM>-t-butylphenol), <NUM>,<NUM>,<NUM>-tris-(<NUM>-methyl-hydroxy-<NUM>-t-butylphenyl)butane, tetrakis[methylene-<NUM>-(<NUM>',<NUM>'-butyl-<NUM>-hydroxyphenyl)propionate]methane, <NUM>,<NUM>,<NUM>-tris-(<NUM>-methyl-<NUM>-hydroxy-<NUM>-t-butylphenol)butane, <NUM>,<NUM>,<NUM>-trimethyl-<NUM>,<NUM>,<NUM>-tris(<NUM>,<NUM>-di-t-butyl-<NUM>-hydroxybenzyl)benzene, bis(<NUM>,<NUM>'-t-butylphenol)butyric acid glycol ester, bis(<NUM>-t-butyl-<NUM>-hydroxy-<NUM>-methylbenzenepropanoic acid) ethylenebis (oxyethylene), and the like. One kind or two or more kinds among these oxidation inhibitors are suitably used.

Examples of the phosphorus-based oxidation inhibitor include tridecyl phosphite, tris(tridecyl) phosphite, triphenyl phosphite, trinonylphenyl phosphite, bis(tridecyl)pentaerithritol diphosphite, bis(decyl)pentaerithritol diphosphite, tris(<NUM>,<NUM>-di-t-butylphenyl) phosphite, bis(<NUM>,<NUM>-di-t-butyl-<NUM>-methylphenyl)ethyl ester phosphorous acid, tris(<NUM>,<NUM>-di-t-butylphenyl) phosphite, <NUM>,<NUM>'-methylenebis(<NUM>,<NUM>-di-t-butyl-<NUM>-phenyloxy) (<NUM>-ethylhexyloxy)phosphorus, and the like. One kind or two or more kinds among these oxidation inhibitors are suitably used.

Examples of a commercial product of the oxidation inhibitor include "IRGANOX <NUM>" available from BASF Japan Ltd. , "IRGAFOS <NUM>" available from BASF Japan Ltd. , "IRGAFOS <NUM>" available from BASF Japan Ltd. , "Sumilizer BHT" available from Sumitomo Chemical Co. , "IRGANOX <NUM>" available from BASF Japan Ltd. , and the like.

With regard to the interlayer film and laminated glass, in order to maintain high visible light transmittance thereof over a long period of time, it is preferred that the content of the oxidation inhibitor be <NUM>% by weight or more in <NUM>% by weight of the interlayer film or in <NUM>% by weight of the layer containing the oxidation inhibitor (a first layer, a second layer or a third layer). Moreover, since an effect commensurate with the addition of an oxidation inhibitor is not attained, it is preferred that the content of the oxidation inhibitor be <NUM>% by weight or less in <NUM>% by weight of the interlayer film or in <NUM>% by weight of the layer containing the oxidation inhibitor.

Each of the first layer, the second layer and the third layer may contain additives such as a coupling agent containing silicon, aluminum or titanium, a dispersing agent, a surfactant, a flame retardant, an antistatic agent, a pigment, a dye, an adhesive force regulating agent, a moisture-resistance improving agent, a fluorescent brightening agent and an infrared ray absorber, as necessary. One kind of these additives may be used alone, and two or more kinds thereof may be used in combination.

The thickness of the interlayer film is not particularly limited. From the viewpoint of the practical aspect and the viewpoint of sufficiently enhancing the penetration resistance of laminated glass, the thickness of the interlayer film is preferably <NUM> or more, more preferably <NUM> or more, preferably <NUM> or less and more preferably <NUM> or less. When the thickness of the interlayer film is the above lower limit or more, the penetration resistance of laminated glass is enhanced. When the thickness of the interlayer film is the above upper limit or less, the transparency of the interlayer film is further improved.

It is preferred that the interlayer film be obtained by melt extrusion molding.

The production method of the interlayer film is not particularly limited. In the case of a single-layered interlayer film, examples of the production method of the interlayer film include a method of extruding a resin composition with an extruder. In the case of a multilayered interlayer film, examples of the production method of the interlayer film include a method of separately forming respective resin compositions used for constituting respective layers into respective layers, and then, for example, layering the respective obtained layers, a method of coextruding respective resin compositions used for constituting respective layers with an extruder and layering the respective layers, and the like. A production method of extrusion-molding is preferred because the method is suitable for continuous production.

Since the production efficiency of the interlayer film is excellent, it is preferred that respective polyvinyl acetal resins contained in the second layer and the third layer be the same as each other, it is more preferred that respective polyvinyl acetal resins contained in the second layer and the third layer be the same as each other and respective plasticizers contained therein be the same as each other, and it is further preferred that the second layer and the third layer be formed from the same resin composition as each other.

<FIG> is a sectional view schematically showing an example of laminated glass prepared with the interlayer film for laminated glass shown in <FIG>.

The laminated glass <NUM> shown in <FIG> is provided with a first lamination glass member <NUM>, a second lamination glass member <NUM>, and an interlayer film part <NUM>'. The interlayer film part <NUM>' is arranged between the first lamination glass member <NUM> and the second lamination glass member <NUM> to be sandwiched therebetween.

The interlayer film part <NUM>' is formed of the interlayer film <NUM>.

The first lamination glass member <NUM> is layered on a first surface 11a of the interlayer film part <NUM>'. The second lamination glass member <NUM> is layered on a second surface 11b opposite to the first surface 11a of the interlayer film part <NUM>'. The first lamination glass member <NUM> is layered on an outer surface 2a of a second layer <NUM>. The second lamination glass member <NUM> is layered on an outer surface 3a of a third layer <NUM>.

The laminated glass 31A shown in <FIG> is provided with a first lamination glass member <NUM>, a second lamination glass member <NUM> and an interlayer film part 11A'. The interlayer film part 11A' is arranged between the first lamination glass member <NUM> and the second lamination glass member <NUM> to be sandwiched therebetween.

The interlayer film part 11A' is formed of the interlayer film 11A.

The first lamination glass member <NUM> is layered on a first surface 11a of the interlayer film part 11A'. The second lamination glass member <NUM> is layered on a second surface 11b opposite to the first surface 11a of the interlayer film part 11A'.

As described above, the laminated glass is provided with a first lamination glass member, a second lamination glass member, and an interlayer film part and the interlayer film part is formed of the interlayer film for laminated glass according to the present invention. In the laminated glass, the above-mentioned interlayer film part is arranged between the first lamination glass member and the second lamination glass member.

Examples of the lamination glass member include a glass plate, a PET (polyethylene terephthalate) film, and the like. As the laminated glass, laminated glass in which an interlayer film is sandwiched between a glass plate and a PET film or the like, as well as laminated glass in which an interlayer film is sandwiched between two glass plates, is included. The laminated glass is a laminate provided with a glass plate, and it is preferred that at least one glass plate be used. It is preferred that each of the first lamination glass member and the second lamination glass member be a glass plate or a PET film, and the laminated glass be provided with a glass plate as at least one among the first lamination glass member and the second lamination glass member. It is preferred that both of the first lamination glass member and the second lamination glass member be glass plates (a first glass plate and a second glass plate). The interlayer film is arranged between a first glass plate and a second glass plate to suitably obtain laminated glass.

Examples of the glass plate include a sheet of inorganic glass and a sheet of organic glass. Examples of the inorganic glass include float plate glass, heat ray-absorbing plate glass, heat ray-reflecting plate glass, polished plate glass, figured glass, wired plate glass, and the like. The organic glass is synthetic resin glass substituted for inorganic glass. Examples of the organic glass include a polycarbonate plate, a poly(meth)acrylic resin plate, and the like. Examples of the poly(meth)acrylic resin plate include a polymethyl (meth)acrylate plate, and the like.

The thickness of the lamination glass member is preferably <NUM> or more, preferably <NUM> or less, and more preferably <NUM> or less. Moreover, when the lamination glass member is a glass plate, the thickness of the glass plate is preferably <NUM> or more, more preferably <NUM> or more, preferably <NUM> or less, and more preferably <NUM> or less. When the lamination glass member is a PET film, the thickness of the PET film is preferably <NUM> or more and preferably <NUM> or less.

The method for producing the laminated glass is not particularly limited. For example, the interlayer film is sandwiched between the first lamination glass member and the second lamination glass member, and then, passed through pressure rolls or subjected to decompression suction in a rubber bag, so that the air remaining between the first and the second lamination glass members and the interlayer film is removed. Afterward, the members are preliminarily bonded together at about <NUM> to <NUM> to obtain a laminate. Next, by putting the laminate into an autoclave or by pressing the laminate, the members are press-bonded together at about <NUM> to <NUM> and under a pressure of <NUM> to <NUM> MPa. In this way, laminated glass can be obtained. At the time of producing the laminated glass, a first layer, a second layer and a third layer may be layered.

Each of the interlayer film and the laminated glass can be used for automobiles, railway vehicles, aircraft, ships, buildings and the like. Each of the interlayer film and the laminated glass can also be used for applications other than these applications. It is preferred that the interlayer film and the laminated glass be an interlayer film and laminated glass for vehicles or for building respectively, and it is more preferred that the interlayer film and the laminated glass be an interlayer film and laminated glass for vehicles respectively. Each of the interlayer film and the laminated glass can be used for a windshield, side glass, rear glass or roof glass of an automobile, and the like. The interlayer film and the laminated glass are suitably used for automobiles. The interlayer film is used for obtaining laminated glass of an automobile.

Hereinafter, the present invention will be described in more detail with reference to examples.

The following materials were used in examples and comparative examples.

Polyvinyl acetal resins shown in the following Table <NUM> were appropriately used. In all polyvinyl acetal resins used, n-butyraldehyde which has <NUM> carbon atoms is used for the acetalization.

With regard to the polyvinyl acetal resin, the acetalization degree (the butyralization degree), the acetylation degree, and the content of the hydroxyl group were measured by a method in accordance with JIS K6728 "Testing methods for polyvinyl butyral". In this connection, even in the cases of being measured according to ASTM D1396-<NUM>, numerical values similar to those obtained by a method in accordance with JIS K6728 "Testing methods for polyvinyl butyral" were exhibited.

3GO (triethylene glycol di-<NUM>-ethylhexanoate).

Tinuvin <NUM> (<NUM>-(<NUM>'-hydroxy-<NUM>'-t-butyl-<NUM>-methylphenyl)-<NUM>-chlorobenzotriazole, "Tinuvin <NUM> available from BASF Japan Ltd.

Preparation of composition for forming interlayer film:
One hundred parts by weight of a polyvinyl acetal resin of a kind shown in the following Table <NUM>, <NUM> parts by weight of a plasticizer of a kind shown in the following Table <NUM>, <NUM> parts by weight of an ultraviolet ray screening agent (Tinuvin <NUM>), magnesium acetate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm, and <NUM> parts by weight of an oxidation inhibitor (BHT) were mixed to obtain a composition for forming an interlayer film.

Using an extruder, the composition for forming an interlayer film was extruded. A sheet extruded was immersed in warm water at <NUM> for <NUM> seconds, after which, by making the sheet pass through a cooling roll, the surface temperature thereof was decreased to <NUM> to prepare a single-layered interlayer film (<NUM> in thickness).

Two washed and dried sheets of transparent float glass (<NUM> in longitudinal length × <NUM> in transversal length × <NUM> in thickness) were prepared. The obtained interlayer film was sandwiched between the two glass plates to obtain a laminate. The obtained laminate was put into a bag and the inside of the vacuum bag was degassed at a degree of vacuum of <NUM> hPa and at ordinary temperature (<NUM>). Subsequently, the temperature inside the vacuum bag was elevated to <NUM> while maintaining the degassed state, and after the temperature reached <NUM>, the laminate was held for <NUM> minutes. Afterward, the vacuum bag was allowed to spontaneously cool and it was confirmed that the temperature was lowered to <NUM>, after which the pressure was released to the atmosphere.

The laminated glass preliminarily press-bonded by the above-mentioned vacuum bag method was press-bonded for <NUM> minutes under conditions of <NUM> and a pressure of <NUM> MPa using an autoclave to obtain a sheet of laminated glass.

In Examples <NUM> to <NUM> and Comparative Example <NUM>, a single-layered interlayer film was prepared in the same manner as that in Example <NUM> except that the kind of ingredients to be blended and the content thereof were set to those listed in the following Table <NUM>. With the use of the obtained interlayer film, a sheet of laminated glass provided with the interlayer film was prepared in the same manner as that in Example <NUM>.

In Comparative Example <NUM>, a single-layered interlayer film was prepared in the same manner as that in Example <NUM> except that the kind of ingredients to be blended and the content thereof were set to those listed in the following Table <NUM> and a sheet extruded was immersed in water at <NUM> for <NUM> seconds instead of being immersed in warm water at <NUM> for <NUM> seconds. With the use of the obtained interlayer film, a sheet of laminated glass provided with the interlayer film was prepared in the same manner as that in Example <NUM>.

Moreover, in Examples <NUM> to <NUM> and Comparative Examples <NUM> and <NUM>, each of the ultraviolet ray screening agent and the oxidation inhibitor of the same kind as that in Example <NUM> was blended in the same blending amount (<NUM> parts by weight relative to <NUM> parts by weight of the polyvinyl acetal resin) as that in Example <NUM>.

In Example <NUM>, magnesium acetate in an amount that the content of magnesium derived from magnesium acetate in the resulting interlayer film becomes <NUM> ppm was used and magnesium <NUM>-ethylbutyrate in an amount that the content of magnesium derived from magnesium <NUM>-ethylbutyrate in the resulting interlayer film becomes <NUM> ppm was used. In Example <NUM>, magnesium <NUM>-ethylbutyrate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used and potassium acetate in an amount that the content of potassium in the resulting interlayer film becomes <NUM> ppm was used. In Comparative Example <NUM>, magnesium <NUM>-ethylbutyrate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used.

In Example <NUM>, magnesium acetate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used and potassium <NUM>-ethylhexanoate in an amount that the content of potassium in the resulting interlayer film becomes <NUM> ppm was used. In Comparative Example <NUM>, magnesium acetate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used and potassium acetate in an amount that the content of potassium in the resulting interlayer film becomes <NUM> ppm was used. In Example <NUM>, magnesium acetate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used and magnesium <NUM>-ethylbutyrate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used. In Example <NUM>, magnesium acetate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used and magnesium <NUM>-ethylbutyrate in an amount that the content of magnesium in the resulting interlayer film becomes <NUM> ppm was used.

In Example <NUM>, the amount of a heat shielding compound, shown in the following Table <NUM>, used in <NUM>% by weight of the resulting interlayer film was set to an amount shown in the following Table <NUM>.

With the use of TOF-SIMS, a portion on a first surface of the interlayer film was measured for Ratio<NUM> of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin (Polyvinyl Acetal Resin). Next, a sputtering and measurement process in which the first surface portion measured for Ratio<NUM> is subjected to sputtering one time and measured for Ratio of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin (Polyvinyl Acetal Resin) with the use of TOF-SIMS was performed n times to collect n Rations of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin (Polyvinyl Acetal Resin) obtained from the first to n-th sputtering and measurement processes. Measurement conditions are as defined above.

The sheet of laminated glass obtained was allowed to settle for two weeks under an environment of <NUM> and a humidity of <NUM>%RH, after which the length of a whitened portion extending from the midpoint of each of four sides of the sheet of laminated glass was measured. Among four measured values of the length of a whitened portion extending from the midpoint of each of four sides of the sheet of laminated glass, the largest value of the length of a whitened portion was evaluated.

The obtained interlayer films were allowed to stand under high humidity to obtain an interlayer film with a water content of <NUM>% by weight, an interlayer film with a water content of <NUM>% by weight, and an interlayer film with a water content of <NUM>% by weight.

Two washed and dried sheets of transparent float glass (<NUM> in longitudinal length × <NUM> in transversal length × <NUM> in thickness) were prepared. The interlayer film adjusted in its water content was sandwiched between the two glass plates to obtain a laminate. The obtained laminate was put into a bag and the inside of the vacuum bag was degassed at a degree of vacuum of <NUM> hPa and at ordinary temperature (<NUM>). Subsequently, the temperature inside the vacuum bag was elevated to <NUM> while maintaining the degassed state, and after the temperature reached <NUM>, the laminate was held for <NUM> minutes. Afterward, the vacuum bag was allowed to spontaneously cool and it was confirmed that the temperature was lowered to <NUM>, after which the pressure was released to the atmosphere.

The obtained sheet of laminated glass (<NUM> in longitudinal length × <NUM> in transversal length) was stored at -<NUM> ± <NUM> for <NUM> hours. The center part (the area of <NUM> in longitudinal length × <NUM> in transversal length) of the sheet of laminated glass after storage was struck and broken by a hammer with a head of <NUM> until broken pieces of glass were allowed to have a particle diameter of <NUM> or less. The center part (the area of <NUM> in longitudinal length × <NUM> in transversal length) of the sheet of laminated glass was broken, after which the degree of exposure of the interlayer film (% by area) was measured to determine the pummel value according to the following Table <NUM>. An average value of <NUM> measured values was adopted as the pummel value.

The results are shown in the following Table <NUM>. In this connection, in the following Table <NUM>, the description of ingredients to be blended other than the thermoplastic resin (polyvinyl acetal resin), the plasticizer, and the metal salt was omitted.

Claim 1:
An interlayer film for laminated glass, having a one-layer structure or a two or more-layer structure and
containing a thermoplastic resin, the thermoplastic resin containing a polyvinyl butyral resin,
wherein a portion on a first surface of the interlayer film is measured for Ratio<NUM> of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin with the use of TOF-SIMS, and
a sputtering and measurement process in which the first surface portion measured for Ratio<NUM> is subjected to sputtering one time and measured for Ratio of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin with the use of TOF-SIMS is performed n times, and n Rations of Ion Intensity of Magnesium/Ion Intensity of Thermoplastic Resin obtained from the first to n-th sputtering and measurement processes are collected to calculate an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, and an average value<NUM> ≤ n ≤ <NUM> of <NUM> values of Ratio<NUM> ≤ n ≤ <NUM> measured within a range of <NUM> ≤ n ≤ <NUM>, the Ion Intensities of Magnesium and Ion Intensities of Thermoplastic Resin each being measured according to the method in the description,
among these five average values, the average value indicating the smallest value is the average value<NUM> ≤ n ≤ <NUM> or the average value<NUM> ≤ n ≤ <NUM> and the average value indicating the largest value is the average value<NUM> ≤ n ≤ <NUM>, the average value<NUM> ≤ n ≤ <NUM>, or the average value<NUM> ≤ n ≤ <NUM>,
and wherein, in the case of an interlayer film with the one-layer structure, the content of magnesium in the interlayer film is <NUM> ppm or less and the content of potassium in the interlayer film is <NUM> ppm or less, and
in the case of an interlayer film with the two or more-layer structure, the content of magnesium in a surface layer positioned at the first surface side is <NUM> ppm or less, and the content of potassium in the surface layer positioned at the first surface side is <NUM> ppm or less.