Patent Description:
Conventionally, in insulating glass including two or more sheets of glass that are spaced apart via only a spacer so that an air space layer is formed therebetween, insulating glass is known in which the spacer is made from a thermoplastic resin composition having a JIS A hardness of <NUM> to <NUM> at <NUM>, and the thermoplastic resin composition contains a butyl-type rubber, a crystalline polyolefin, a desiccant, and an inorganic filler, wherein a percentage of the butyl-type rubber with respect to the total amount of the butyl-type rubber and the crystalline polyolefin is <NUM> to <NUM>% by weight, the percentage of crystalline polyolefin is <NUM> to <NUM>% by weight, and the percentage of inorganic filler with respect to the total amount of the butyl-type rubber and the crystalline polyolefin is <NUM> or less (See, for example, Patent Document <NUM>). Further, Patent Document <NUM> describes a thermoplastic elastomer composition allegedly excellent in rubber elasticity, mechanical strength, flexibility and heat resistance, and a molded article thereof. Patent Document <NUM> describes a single-sealed multilayer transparent unit, particularly a single-sealed doubleglazing glass, wherein as a spacer, only an elastomer spacer is used which contains, as the matrix component, at least one butyl elastomer component selected from the group consisting of polyisobutylene, butyl rubber and modified butyl rubber, and a process for its production. Patent Document <NUM> describes a double glazing.

According to the insulating glass above, by using the thermoplastic resin composition having the JIS A hardness of <NUM> to <NUM> at <NUM> as the spacer, the complication of the manufacturing process when the metal spacer is used can be solved, and the problem of a long time curing necessary to use a room temperature curable sealant can be solved, thereby improving the productivity.

However, when manufacturing the insulating glass unit disclosed in Patent Document <NUM>, if any spacer material is selected, the surface of the spacer material may have roughness, which is not necessarily preferable from the viewpoint of the adhesion between the spacer and the glass sheets.

Accordingly, the present invention is intended to provide an insulating glass unit, a method of manufacturing an insulating glass unit, and a sealing material for an insulating glass unit that have good adhesion between the spacer and the glass sheet and can increase long-term reliability.

In order to achieve the above-described object, an insulating glass unit of one embodiment of present invention includes two or more glass sheets disposed to face each other via a spacer interposed between the glass sheets so as to form an air space layer between the glass sheets, characterized in that the spacer is formed of a thermoplastic resin composition having a JIS A hardness of <NUM> to <NUM> at <NUM>, the thermoplastic resin composition containing a butyl type rubber, a crystalline polyolefin, a desiccant and an inorganic filler, a percentage of the butyl type rubber is <NUM> to <NUM> mass%, and a percentage of the crystalline polyolefin is <NUM> to <NUM> mass% with respect to a total amount of the butyl type rubber and the crystalline polyolefin, a proportion of the inorganic filler is <NUM> parts by mass or less with respect to a total of <NUM> parts by mass of the butyl type rubber and the crystalline polyolefin, and a percentage of dispersion defined by ISO <NUM>:<NUM> E method is <NUM>% or more, wherein the butyl type rubber contains a high molecular weight butyl type rubber and a low molecular weight butyl type rubber, the high molecular weight butyl type rubber has a number average molecular weight of <NUM> or more and <NUM> or less, and the low molecular weight butyl type rubber has a number average molecular weight of <NUM> or more and <NUM> or less.

According to the present invention, adhesion between a spacer and a glass sheet can be improved, and long-term reliability of an insulating glass unit can be improved.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

<FIG> is a partial schematic cross-sectional view illustrating an example of a structure of insulating glass according to a first embodiment of the present invention. As shown in <FIG>, insulating glass <NUM> is held at a predetermined distance by only a spacer <NUM> such that two glass sheets 1a and 1b form an air space layer <NUM> therebetween. The spacer <NUM> is formed of a thermoplastic resin composition having a JIS A hardness of <NUM> to <NUM> and a dispersion degree of <NUM>% or more. The dispersion is defined by ISO <NUM>:<NUM> E method. The term "by only a spacer <NUM>" used above means that a secondary sealant, a metal spacer and the like are not required, and that a primer process that is applied if necessary is included.

The melt viscosity is the viscosity at <NUM> and at a shear rate of <NUM>/s measured according to the method defined in JIS K <NUM> (<NUM>) using a capillary having a capillary length of <NUM> and a capillary diameter of <NUM>, and a capillary rheometer having a furnace with a furnace body diameter of <NUM>.

The thermoplastic resin composition used for the spacer material in the configuration of the insulating glass unit according to the first embodiment of the present invention is a thermoplastic resin composition having JIS A hardness of <NUM> to <NUM> at <NUM>. Any of the thermoplastic resin compositions may be used as long as the resin composition has the above-described properties and the degree of dispersion defined in the ISO <NUM>:<NUM> E method is <NUM>% or more.

In <FIG>, the insulating glass unit <NUM> includes the spacer <NUM> between two opposing glass sheets 1a and 1b. However, when the surface of the spacer <NUM> has roughness, the insulating glass unit <NUM> is not necessarily preferable from the viewpoint of adhesiveness of the spacer <NUM> to the glass sheets 1a and 1b.

When the dispersion degree of the thermoplastic resin composition used in the spacer material defined by the ISO <NUM>:<NUM> E method is <NUM>% or more, the surface of the spacer material becomes flat; the spacer <NUM> preferably has some adhesiveness to the glass sheets 1a and 1b; and the long-term reliability of the insulating glass unit can be improved. The dispersion degree is preferably <NUM>% or more, more preferably <NUM>% or more, and more and more preferably <NUM>% or more. The upper limit of the dispersion degree is not particularly limited, but may be <NUM>% or less and may be <NUM>% or less. To increase the dispersion degree, there are methods for reducing the proportion of crystalline polyolefins with respect to the thermoplastic composition, and for lengthening the kneading time of a butyl type rubber, a crystalline polyolefin, and an inorganic filler as described below.

Next, various examples of specific thermoplastic resin compositions that can be used for the insulating glass unit <NUM> in accordance with the present embodiment will be described below.

For example, thermoplastic elastomers used in many applications in recent years and rubber-based materials in which the vulcanization density is adjusted to be able to melt and flow by heating, are included in the "thermoplastic resin composition" of the present invention as long as they have the above-described properties. Furthermore, the thermoplastic resin compositions including so-called plasticizers such as dibutylphthalate and di-<NUM>-ethylhexylphthalate are also included in the "thermoplastic resin compositions" of the present invention as long as they have the above-described properties.

Specifically, the resin composition used in the present invention preferably contains at least one of thermoformable rubber, elastomer and thermoplastic resin other than the rubber or elastomer described above, more preferably containing both. The resin composition is preferably made from a low moisture permeable rubber, an elastomer, or a thermoplastic. Further, a resin composition preferably incorporates a predetermined amount of desiccant in order to prevent moisture from entering the air space layer of the insulating glass when the insulating glass unit is formed.

The low moisture permeable and thermoformable rubber or elastomer includes a rubber or elastomer preferably having the moisture vapor permeable coefficient of <NUM>×<NUM>-<NUM> cm<NUM>·cm/cm<NUM>·sec·Pa or less, and a butyl-type rubber, such as a copolymer mainly comprised of isobutylene and isoprene, a polyisobutylene, a butyl-type rubber, such as a polyisobutylene or a butyl halide rubber, is preferable. These low moisture permeable and thermoformable rubbers or elastomers may be used alone or used in two or more blends.

The low moisture permeable and thermoplastic resin other than the rubber or elastomer described above includes, for example, polyethylene, polypropylene, vinylidene chloride, polyvinyl chloride and the like, a copolymer of a monomer containing these polymers, or a modified form thereof, and a crystalline polyolefin is preferred, and particularly polyethylene is preferred. The water vapor permeable coefficient of these thermoplastic resins is preferably <NUM>×<NUM>-<NUM> cm<NUM>·cm/cm<NUM> sec·Pa or less, and further preferably <NUM>×<NUM>-<NUM>·cm<NUM>·cm/cm<NUM>·sec·Pa or less. The thermoplastic particularly contributes to the shape-retaining performance of the spacer.

A desiccant is added, or further an inorganic filler or another additive is added as necessary, to the resin composition for the spacer according to the first embodiment of the present invention in addition to the low moisture permeable and thermoformable rubber or elastomer described above, or another low moisture permeable and thermoformable rubber or elastomer other than the rubber or elastomer described above. As a desiccant, any desiccant used in admixture with a conventional insulating glass's spacer or sealant may be used such as zeolite, alumina and silica gel.

Such a resin composition for a spacer preferably contains the above ingredients and may contain tackifiers, lubricants, pigments, antistatic agents, antiaging agents, thermal stabilizers, fillers, blowing agents and the like as additives as necessary.

The resin composition for the spacer is adjusted by kneading the ingredients. In adjusting the resin composition, it is important to combine the necessary ingredients so that the hardness of JIS A at <NUM> or less becomes <NUM> or less. The reasons for setting the hardness to <NUM> or less are as follows.

When a thermoplastic resin composition having a hardness of JIS A over <NUM> is used as a spacer for insulating glass unit, because creep hardly occurs, if the endurance test shown in JIS R <NUM> is performed, the stress caused by the expansion of air is applied to the adhesion interface of the glass sheet and the spacer at a high temperature. For this reason, if the adhesion is insufficient, peeling occurs, and even if the adhesion is secured, the glass may break. Although it is possible to obtain adhesive strength sufficient to withstand the expansive stress of the air space layer by applying high temperatures or high pressures to the adhesive currently known, it does not suit to the present invention's objective of reducing manufacturing costs because high temperatures and high pressures cause breakage of the glass and greatly decrease productivity. In addition, the properties are inappropriate as an insulating glass unit because the insulating glass unit is likely to break in the actual use environment.

On the other hand, if the hardness is too low, problems arise in shape retention properties of the insulating glass. Therefore, it is important to add the required ingredients to the resin composition so that the hardness of JIS A at <NUM> of the resin composition becomes <NUM> or higher. Furthermore, when the hardness of JIS A is <NUM> or more but the hardness is relatively small, if the air space layer <NUM> is thick, misalignment between the glass sheets 1a and 1b (which is hereinafter referred to as "sheet misalignment") may occur.

Commonly used insulating glass unit has an air space layer <NUM> with a thickness of about <NUM> to <NUM> (often <NUM> or <NUM>). Accordingly, when the hardness is relatively small, sheet misalignment may not occur when the thickness of the air space layer is <NUM>, but when the thickness is <NUM>, the sheet misalignment may occur. By increasing the hardness to <NUM> or more, it is possible to prevent the sheet from shifting even if the thickness of the air space layer is <NUM>. Therefore, it is particularly preferable that the JIS A hardness of the thermoplastic spacer be <NUM> or more in the insulating glass according to the present invention.

An insulating glass, which uses a resin composition with JIS A hardness over <NUM> as a spacer, causes great stresses on a glass sheet. Therefore, during the accelerated durability test, glass breakage occurs in both insulating glass units with a thickness of <NUM> and a thickness of <NUM> as defined in JIS R <NUM>.

In contrast compared to the above, the insulating glass unit using the resin composition with JIS A hardness of <NUM> as a spacer does not break the glass sheet in the insulating glass unit using the glass sheet with a thickness of <NUM> in the above test. In the meantime, an insulating glass unit using <NUM> thick glass sheets may cause a glass breakage in the above test. Therefore, the upper limit of the JIS A hardness of the resin composition for the spacer is <NUM>. Moreover, in the above test, a glass breakage does not occur in the insulating glass unit using the resin composition with JIS A hardness of <NUM> as a spacer and glass sheets with a thickness of <NUM> and a thickness of <NUM>. The JIS A hardness of the resin composition for the spacer is preferably in a range of <NUM> to <NUM>, because the glass sheet for an insulating glass unit, which is currently commonly used, is <NUM> thick.

Whereas the stipulation of JIS A hardness is instantaneous, creep compliance J, which indicates creep characteristics, shows the properties of the resin when continuous stress is applied, and is expressed as the inverse of the elastic modulus. The creep compliance J is measured as follows, for example.

<FIG> is a schematic cross-sectional view showing a method of measuring creep compliance J. The resin material <NUM> to be measured is shaped to have a thickness of <NUM> with a <NUM>×<NUM> (mm) surface size to be adhered to the glass sheets 91a and 91b. Then, the glass sheet is pulled in the direction of the arrow shown in the figure at an atmospheric temperature of <NUM> so that a stress of <NUM>/cm<NUM> is always applied to the resin material, and the creep compliance J is calculated from the elongated length of material after <NUM> minutes. The value of J does not depend on the thickness of the glass sheets 91a and 91b. Here, a glass sheet having a thickness of <NUM> is used.

For example, the insulating glass unit is adsorbed by a suction disk and the like on one side of the insulating glass and loaded onto a pallet during transport after fabrication. Conversely, when the insulating glass is removed from the pallet, it is similarly adsorbed. The so-called "Hold on one side only" state of the insulating sucker is usually considered to be <NUM> minutes or less. The outdoor temperature in summer rises to about <NUM>. Therefore, the creep compliance J is preferably <NUM>×<NUM>-<NUM> cm<NUM>/dyne or less [<NUM>, shear mode, and <NUM> minutes after the start of measurement] in order not to cause sheet misalignment during use.

In addition, when the creep compliance J is less than <NUM>×<NUM>-<NUM> cm<NUM>/dyne at [<NUM>, shear mode, and <NUM> minutes after the start of measurement], because the resin material does not substantially creep, the stress applied between the glass sheet and the spacer increases while causing problems such as peeling and glass breakage. Therefore, J at [<NUM>, shear mode, <NUM> minutes after starting measurement] is preferably <NUM>×<NUM>-<NUM> cm<NUM>/dyne or more.

As described above, the thickness of the air space layer of the insulating glass is often about <NUM> to <NUM>. Therefore, when the creep compliance J is relatively great even if the creep compliance J is <NUM>×<NUM>-<NUM> cm<NUM>/dyne or less at [<NUM>, shear mode, and <NUM> minutes after the start of measurement], the thickness of the air space layer may cause sheet misalignment. For example, when the creep compliance J is great, the sheet misalignment may occur when the air space layer <NUM> has a thickness of <NUM>, even if the sheet misalignment does not occur when the air space layer has a thickness of <NUM>. Therefore, by setting the creep compliance J to <NUM>×<NUM>-<NUM> cm<NUM>/dyne or less, even if the thickness of the air space layer <NUM> is <NUM>, the sheet misalignment can be prevented.

In addition, it is particularly preferable that the lower limit of creep compliance J be <NUM>×<NUM>-<NUM> cm<NUM>/dyne. At a value of <NUM>×<NUM>-<NUM> cm<NUM>/dyne, for example, in the endurance test defined in JIS R <NUM>, even if an insulating glass unit using a glass sheet with a thickness of <NUM> does not break, an insulating glass unit using a glass sheet with a thickness of <NUM> may break. Therefore, it is particularly preferable that the lower limit of creep compliance J is <NUM>×<NUM>-<NUM> cm<NUM>/dyne at [<NUM>, shear mode, and <NUM> minutes after the start of measurement] so as not to cause a breakage of the glass sheet in the glass sheets of various thicknesses.

Taken together with the above, it is particularly preferable that the resin composition used for the spacer according to the present invention has a JIS A hardness of <NUM> to <NUM> and a creep compliance J of <NUM>×<NUM>-<NUM> to <NUM>×<NUM>-<NUM> cm<NUM>/dyne at [<NUM>, shear mode, and <NUM> minutes after the start of measurement].

In addition, it is preferable that the water vapor permeable coefficient of the resin composition as a whole be <NUM>×<NUM>-<NUM> cm<NUM>·cm/cm<NUM>·sec·Pa or less, and that the water vapor permeable coefficient be <NUM>×<NUM>-<NUM> cm<NUM>·cm/cm<NUM>·sec·Pa or less in order to maintain a dew point performance.

The resin composition used in the insulating glass unit <NUM> according to the first embodiment of the present invention includes a butyl-type rubber, a crystalline polyolefin, a desiccant, and an inorganic filler, wherein the percentage of the butyl-type rubber with respect to the total amount of the butyl-type rubber and the crystalline polyolefin is <NUM> to <NUM>% by mass, and the percentage of the crystalline polyolefin with respect to the total amount of the butyl-type rubber and the crystalline polyolefin is <NUM> to <NUM>% by mass, wherein the ratio of the inorganic filler to the total of <NUM> parts by mass of the butyl-type rubber and the crystalline polyolefin is <NUM> parts by mass or less.

The above-described butyl-type rubber refers to isobutylene homopolymers and copolymers thereof with other monomers, and their modifications. As a copolymer, a copolymer obtained by copolymerizing with a relatively small amount of isoprene (usually called butyl rubber) is preferable. Modifiers include halogenated butyl rubber and partially cross-linked butyl rubber. Particularly preferred butyl-type rubber is a copolymer of isobutylene and isoprene, commonly referred to as butyl rubber, and partially cross-linked butyl rubber.

Loss tangent is measured according to JIS K <NUM>:<NUM>. The loss tangent is a value of measuring a sample having a diameter of <NUM> and a thickness of <NUM> in a shear mode, at a frequency of <NUM>, and at a deformation amount of <NUM>%.

The thermoplastic resin composition used for the insulating glass unit <NUM> according to the first embodiment of the present invention preferably has a loss tangent of <NUM> or less defined by JIS K <NUM>:<NUM> at <NUM>. The <NUM> is a temperature that assumes an environment in which the insulating glass unit <NUM> is used. If the loss tangent at <NUM> is <NUM> or less, the fluidity of the thermoplastic resin composition is low, which is preferable for retaining the shape as the insulating glass unit, such as sheet misalignment. The loss tangent at <NUM> is more preferably <NUM> or less, and even more preferably <NUM> or less. The lower limit of the loss tangent at <NUM> is not particularly limited, but is preferably <NUM> or more to maintain the shape, more preferably <NUM>, and is more and more preferably <NUM>.

The thermoplastic resin composition used for the insulating glass unit <NUM> according to the first embodiment of the present invention preferably has a loss tangent of <NUM> or more. The loss tangent is defined by JIS K <NUM>:<NUM> at <NUM>. The <NUM> is a temperature that assumes the environment in which the thermoplastic resin is molded. If the loss tangent at <NUM> is <NUM> or more, the molding fluidity is high, and molding is easy. More preferably, the loss tangent at <NUM> is <NUM> or more, and even more preferably <NUM> or more. The upper limit of the loss tangent at <NUM> is not particularly limited, but is preferably <NUM> or less, more preferably <NUM> or more, and more and more preferably <NUM> or more in order to maintain the shape during molding.

The ratio A/B of the loss tangent A defined by JIS K <NUM>:<NUM> at <NUM> to the loss tangent B defined by JIS K <NUM>:<NUM> at <NUM> is preferably <NUM> or more for the thermoplastic resin composition used for the insulating glass unit <NUM> according to the first embodiment of the present invention. The <NUM> is a temperature that assumes the environment in which the thermoplastic resin composition is molded. If the A/B is <NUM> or more, the fluidity is high during molding, which is preferable. The A/B of <NUM> or more is more preferred, and the A/B of <NUM> or more is even more preferred. The upper limit of A/B is not particularly limited, but is preferably <NUM> or less, more preferably <NUM> or less, and even more preferably <NUM> or less, in order to ensure fluidity during molding.

The resin composition used for the insulating glass unit <NUM> according to the first embodiment of the present invention preferably has a melt viscosity of <NUM> or more kPa·s and <NUM> kPa·s or less at <NUM>.

In <FIG>, the insulating glass unit <NUM> includes a spacer <NUM> between two opposing glass sheets 1a and 1b, and the spacer <NUM> is formed by a melt molding method such as an extrusion molding method or an injection molding method. In performing such extrusion molding or injection molding operation, the molten thermoplastic composition is extruded or injected from an extruder, an applicator, or an injection molding machine. Here, when the melt viscosity of the thermoplastic resin composition that is a spacer material is high, the spacer material cannot be melted and molded, and extrusion of the spacer material from the molding machine is likely to be difficult unless the temperature is increased to <NUM> or more. Molding at such a high temperature, such as over <NUM>, results in butyl type rubber approaching the pyrolysis temperature. Therefore, when the butyl type rubber is held in a high temperature state for a long time due to a problem during molding and the like, the butyl type rubber may decompose, which is liable to cause physical strength degradation or gas barrier property degradation.

In contrast, when the temperature is <NUM> or less, because the temperature does not reach the decomposition temperature of the butyl type rubber, there is little concern about the decomposition; the physical strength of the butyl type rubber after molding is maintained; and the gas barrier property is unlikely to decrease. When the melt viscosity of the thermoplastic resin composition used as a spacer material at <NUM> is within the range of <NUM> kPa·s to <NUM> kPa·s, the thermoplastic resin composition is likely to mold even at a temperature of <NUM> or less. As a result, the discharge amount of the spacer material is increased, high-speed molding becomes possible, and the manufacturing tact is shortened. Cost reduction is also possible from the viewpoint of energy reduction during the manufacture. Further, because the spacer material can be molded without being heated to high temperature, degradation during molding of the spacer material itself can be reduced and long-term reliability can be improved. Incidentally, the temperature of the thermoplastic resin composition may be set to any degree C, as long as the temperature is <NUM> or less, but may be set, for example, to a predetermined temperature in the range of <NUM> to <NUM>. Specifically, the temperature may be set, for example, to a temperature from <NUM> to <NUM>.

The lower the melt viscosity becomes, the less workload the molding machine has, but if the melt viscosity is too low, it is difficult to form a certain shape due to the low viscosity. Therefore, from the viewpoint that the spacer material has moldable viscosity and the workload of the molding machine is small, the melt viscosity is set in the above-described range of <NUM> kPa·s to <NUM> kPa·s. The melt viscosity is preferably <NUM> kPa·s or more and <NUM> kPa·s or less, and more preferably <NUM> kPa·s or more and <NUM> kPa·s or less.

The resin composition used for the insulating glass unit <NUM> according to the first embodiment of the present invention preferably has a storage elastic modulus E' of <NUM> MPa or more and <NUM> MPa or less at <NUM>.

The insulating glass unit <NUM> is actually used only after the molded spacer <NUM> has been cooled, solidified and completed as the insulating glass unit <NUM>, and the temperature to be used is typically around <NUM> of room temperature. In this case, when the elastic modulus of the spacer <NUM> is too low at room temperature, the sheet misalignment is likely to occur, and a shape retention problem is likely to occur. Further, when the elastic modulus of the spacer <NUM> at room temperature is too high, because stress relaxation by deformation of the sealing material in response to the deformation of the air space layer <NUM> caused by a change in temperature does not occur, the glass sheets 1a and 1b are likely to break. Accordingly, the spacer <NUM> preferably has a suitable modulus of elasticity at room temperature. When the storage elastic modulus E' at <NUM> is <NUM> MPa or more and <NUM> MPa or less, it is possible to form a spacer <NUM> that is unlikely to cause misalignment of the glass sheets 1a and 1b and that is resistant to damage by itself. The storage elastic modulus E' at <NUM> is preferably <NUM> MPa or more and <NUM> MPa or less, more preferably <NUM> MPa or more and <NUM> MPa or less, more preferably <NUM> MPa or more and <NUM> MPa or less, and particularly preferably <NUM> MPa or more and <NUM> MPa or less.

Here, the storage elastic modulus E' is a component of energy stored inside an object among energy generated by external force to the object and deformation of the object, and represents elasticity (spring) rather than viscosity. Therefore, as the storage modulus E' increases, the elasticity increases. The storage elastic modulus E' is a value of the storage elastic modulus at a temperature of <NUM> obtained from the results of a tensile test performed so that a sample having a grabbing interval of <NUM>, a width of <NUM> and a thickness of <NUM> is raised to <NUM>/min in the constant-speed warming mode and becomes to have a deformation of <NUM>%, a static/dynamic ratio of <NUM> and a frequency of <NUM>. By using a thermoplastic resin composition having a storage elastic modulus E' of <NUM> MPa or more and <NUM> MPa or less at <NUM> as the spacer material, the elasticity of the spacer <NUM> at room temperature can be appropriately maintained, and thus it is possible to form the insulating glass unit <NUM> including the glass sheets 1a and 1b unlikely to break and unlikely to be out of alignment.

As described above, as a method of setting the melt viscosity at <NUM> to <NUM> kPa·s or more and <NUM> kPa or less, and setting the storage elastic modulus E' at <NUM> to <NUM> MPa or more and <NUM> MPa or less, there is a method of adjusting the molecular weight of the butyl-type rubber. This point is explained below.

The thermoplastic resin composition used as a material for the spacer <NUM> of the insulating glass <NUM> according to the present embodiment contains a butyl-type rubber. The butyl-type rubber contained in the thermoplastic resin composition contains two types of materials: a high molecular weight side material forming a high molecular weight butyl-type rubber and a low molecular weight side material forming a low molecular weight butyl-type rubber.

Here, although the chemical structure of the high molecular weight butyl-type rubber and the low molecular weight butyl-type rubber is almost the same, their molecular weights are different. Because the chemical structure is the same, gas permeability, chemical resistance and the like are the same, but physical properties such as melt viscosity and elastic modulus are different due to the different molecular weights. The high molecular weight butyl-type rubber is a block-shaped solid that exhibits elastomeric properties. On the other hand, the low molecular weight butyl-type rubber exhibits viscous liquid and adhesive properties.

In the insulating glass unit <NUM> according to the present embodiment, in order to increase the fluidity (decrease the melt viscosity) at high temperatures while maintaining the elastic modulus at room temperature, the difference in physical properties due to the molecular weight of the butyl-type rubber is used. Hereinafter, the details will be described.

In order to reduce the melt viscosity, because the molecular weight of the high molecular weight butyl-type rubber has a significant influence, it is preferable to use a material having a lower molecular weight in a range indicating the physical properties (high elastomericity and elasticity) of the high molecular weight butyl-type rubber in selecting the high molecular weight butyl-type rubber. Specifically, as the high molecular weight butyl-type rubber, a material is used having a number average molecular weight of <NUM>,<NUM> or more and <NUM>,<NUM> or less, and it is preferable to use a material having a number average molecular weight of <NUM>,<NUM> or more and <NUM>,<NUM> or less. Further, it is more preferable to use a material having a number average molecular weight of <NUM>,<NUM> or more and <NUM>,<NUM> or less, and it is particularly preferable to use a material having a number average molecular weight of <NUM>,<NUM> or more and <NUM>,<NUM> or less.

The percentage of the high molecular weight butyl-type rubber with respect to the total weight is preferably <NUM> to <NUM>% by mass, more preferably <NUM> to <NUM>% by mass, and even more preferably <NUM> to <NUM>% by mass. When the percentage is more than <NUM>% by mass, it can increase the elasticity modulus at room temperature. If it is <NUM>% by mass or less, the melt viscosity at high temperature can be reduced.

When a butyl type rubber at a lower molecular weight side is selected from among high molecular weight butyl type rubbers as the high molecular weight butyl type rubber, a decrease in the elastic modulus may occur at room temperature, and problems may occur in the shape retention property as the insulating glass unit, such as sheet misalignment. Therefore, in order to reduce the melt viscosity and to maintain the elastic modulus at room temperature, in the selection of the low molecular weight butyl type rubber, a material at a higher molecular weight side is preferably selected within a range in which the physical properties (i.e., high viscosity) of the low molecular weight butyl type rubber are exhibited. Specifically, as the low molecular weight butyl type rubber, a material is used having a number average molecular weight of <NUM> or more and <NUM> or less, and it is preferable to use a material having a number average molecular weight of <NUM> or more and <NUM> or less. The percentage of the low molecular weight butyl-type rubber with respect to the total weight is preferably <NUM> to <NUM>% by mass, more preferably <NUM> to <NUM>% by mass, and even more preferably <NUM> to <NUM>% by mass. If it is <NUM>% by mass or more, the melt viscosity can be reduced at high temperatures. If it is not more than <NUM>% by mass, the modulus of elasticity at room temperature can be increased.

By selecting the materials of butyl type rubbers as described above, it is possible to manufacture and configure the high-quality insulating glass <NUM> including the spacer <NUM> capable of increasing the productivity while maintaining the elastic modulus at room temperature and reducing the melt viscosity at a high temperature.

Next, materials other than butyl-type rubber will be described.

A crystalline polyolefin is referred to as a homopolymer of olefin such as ethylene, propylene and copolymers thereof with another monomer, and a modified form thereof, which has crystalline properties. Preferably, the polymer structure is a syndiotactic structure or an isotactic structure, although other structures may be included. Ethylene and propylene are particularly preferable as olefins.

The copolymer includes a copolymer of two or more types of olefins, or a copolymer of an olefin with another monomer. The copolymer of ethylene or propylene with another monomer that does not inhibit crystallinity is suitable. As the copolymer, a block copolymer is more appropriate than an alternating copolymer and a random copolymer. A modifier includes a crystalline polyolefin to which a functional group such as an anhydride, carboxyl, and epoxy group is introduced.

The crystalline polyolefin is polyethylene and polypropylene, which are substantially homopolymers. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, and the like can be used as the polyethylene. The crystallinity of the crystalline polyolefin is preferably <NUM>% or more, and particularly preferably <NUM>% or more. For example, typical crystallinity values for conventional crystalline polyolefins are <NUM> to <NUM>% for low density polyethylene, <NUM> to <NUM>% for high density polyethylene, and <NUM> to <NUM>% for polypropylene. Although the molecular weight is not particularly limited, a number average molecular weight of about <NUM>,<NUM> to <NUM>,<NUM> for polyethylene and about <NUM>,<NUM> to <NUM>,<NUM> for polypropylene is suitable.

As described above, because polyethylene and polypropylene have high crystallinity, polyethylene and polypropylene have moisture permeability lower than those of butyl-type rubbers. Among them, those that exhibit a significantly low melt viscosity have a lower melt viscosity of the composition and improve moldability of the composition more than those of the butyl-type rubber alone. Accordingly, adding various inorganic fillers becomes possible to achieve higher hardness resin compositions for spacers, and is particularly preferable from an economic standpoint.

The percentage of crystalline polyolefin with respect to the total amount of the butyl-type rubber and the crystalline polyolefin in the resin composition described above is <NUM> to <NUM>% by mass. When the percentage of the crystalline polyolefin is <NUM>% by mass or less, the dispersion degree is likely to be great. When the percentage of the crystalline polyolefin is too excessive, phase separation is significantly expressed, and sometimes the surface of the resin composition becomes rough. The percentage of the crystalline polyolefin with respect to the sum of the butyl rubber and the crystalline polyolefin is preferably <NUM>% by mass or less, more preferably <NUM>% by mass or less, further more preferably <NUM>% or less, and particularly preferably <NUM>% or less. Moreover, the lower limit of the percentage of the crystalline polyolefin with respect to the total amount of the butyl-type rubber and the crystalline polyolefin is <NUM>% by mass or more, preferably <NUM>% by mass or more, and more preferably <NUM>% or more.

When inorganic fillers are added, the percentage of crystalline polyolefin with respect to the total amount of butyl-type rubber and crystalline polyolefin is reduced. For example, when more than <NUM> parts by mass of an inorganic filler is added to a total of <NUM> parts by mass of a butyl-type rubber and crystalline polyolefin, the percentage of the crystalline polyolefin with respect to the total amount of the butyl-type rubber and the crystalline polyolefin is <NUM> to <NUM>% by mass, which is sufficient to exert an effect for the purpose.

Thus, a substantially effective amount of inorganic filler can be added to the resin composition comprising a butyl-type rubber and a crystalline polyolefin. The substantially effective amount means one or more parts by mass with respect to a total of <NUM> parts by mass of the butyl-type rubber and the crystalline polyolefin. The upper limit of the amount of the inorganic filler is <NUM> parts by mass, preferably <NUM> parts by mass, more preferably <NUM> parts by mass, particularly preferably <NUM> parts by mass, and more preferably <NUM> parts by mass, because incorporating too much the inorganic filler increases the melt viscosity of the composition and decreases the tensile strength and tear strength. The preferred lower limit of the formulating amount in the case of an inorganic filler formulation is <NUM> parts by mass, more preferably <NUM> parts by mass, more preferably <NUM> parts by mass, particularly preferably <NUM> parts by mass, more preferably <NUM> parts by mass, and even more preferably <NUM> parts by mass.

As the inorganic filler, calcium carbonate, talc, mica, carbon black and the like, which are normally used as an inorganic filler, can be used alone or in combination with two or more kinds.

Before such a resin composition is used at least for final use, it is highly effective that the butyl-type rubber and the crystalline polyolefin contained therein be mixed at a high temperature. The high temperature in this mixture means a temperature greater than or equal to the crystalline melting point of the crystalline polyolefin. The temperature of this mixture needs to be less than or equal to the decomposition point of the butyl-type rubber, and the temperature does not preferably exceed about <NUM>, which is the decomposition point of the ordinary butyl-type rubber. Especially, the temperature is preferably <NUM> or less from the viewpoint of productivity. Thus, preferably, the crystalline polyolefin also has a crystalline melting point of <NUM> or less.

More preferably, the resin material for the spacer changes hardness as little as possible in the operating temperature range. In order to meet these requirements, a crystalline polyolefin having a crystalline melting point above the normal upper limit of use is preferred. The normal upper operating temperature limit of resin materials for building materials is about <NUM>.

Because the crystalline polyolefin is constrained by the cohesive force of the crystalline phase, even in the temperature range above the glass transition temperature, the sudden drop in hardness and a fluidized state seen in the amorphous resin do not occur below the crystalline melting point. Conversely, a significant decrease in melt viscosity is observed at the crystalline melting point, and an effect is expected of improving the kneading performance with the butyl-type rubber.

Such a resin composition may contain a tackifier, a desiccant and an additive such as carbon black, talc and the like, which may generally be incorporated into the resin material for spacers. Particularly, when the resin composition is used as a spacer, it is preferable to combine a desiccant, such as zeolite, silica gel, or alumina, a tackifier, a plasticizer, a silane coupling agent, and various stabilizers.

In particular, it is preferable to incorporate a desiccant, such as zeolite, into the resin composition from <NUM> to <NUM>% by mass. It is also preferable to add <NUM> parts by mass or less of polyisobutylene, particularly <NUM> to <NUM> parts by mass of polyisobutylene to <NUM> parts by mass of butyl-type rubber other than polyisobutylene in order to provide the adhesion effect and the plasticizing effect.

Alternatively, a tackifier may be added. The viscoelastic temperature characteristics can be controlled by containing the tackifier. As a tackifier, a compound generally known in the art can be used, but from the viewpoint of weather resistance, a compound having a structure that absorbs less ultraviolet light is preferable. Especially, a tackifier of the hydrogenated dicyclopentadiene system is preferable in terms of weather resistance.

In addition, the additive may be formulated with <NUM> to <NUM>% by mass. The additive herein means, for example, a lubricant, a pigment, an antistatic agent, a tackifier, a plasticizer, an antiaging agent, a heat stabilizer, an antioxidant, a hydrolyzable silyl group-containing compound such as a silane coupling agent, a blowing agent, a filler containing an inorganic filler and the like, and the term "additive" used elsewhere means an additive to which a tackifier is added after removing the inorganic filler from the additive.

Taken together, the particularly preferred resin percentage for spacers is <NUM> to <NUM>% by mass of butyl-type rubber, <NUM> to <NUM>% by mass of a crystalline polyolefin, <NUM> to <NUM>% by mass of an inorganic filler, and <NUM> to <NUM>% by mass of a desiccant and an additive (in this case, of course, the percentage of butyl rubber with respect to the total of the butyl rubber and the crystalline polyolefin is <NUM> to <NUM>% by mass, and the percentage of the crystalline polyolefin is <NUM> to <NUM>% by mass).

With the resin composition for the spacer according to the present invention, a spacer having the claimed JIS A hardness and a preferable water vapor transmission coefficient is obtained in the present invention.

The glass sheet used in forming the insulating glass according to the present invention is not limited to particular glass, and includes a window commonly used in a building material and a vehicle, a glass sheet such as a door, tempered glass, laminated glass, glass with a metal net, heat absorbing glass, and further a glass sheet having a thin coating of metal or another inorganic substance on the surface such as heat reflecting glass and low reflection glass, an acrylic resin sheet called organic glass, a polycarbonate sheet and the like.

In addition, the insulating glass unit may be composed of two glass sheets or three or more glass sheets.

<FIG> is a diagram showing an example of insulating glass <NUM> according to a second embodiment of the present invention. The insulating glass unit <NUM> according to the second embodiment differs from the insulating glass unit <NUM> according to the first embodiment in that an adhesive layer <NUM> is provided between glass sheets 1a and 1b and a spacer <NUM>. Thus, the insulating glass unit <NUM> according to the second embodiment of the present invention is formed by applying an adhesive dissolved in a solvent to the glass surface on which the spacer <NUM> abuts. The adhesive layer <NUM> is preferably provided for long-term reliability. Because the components other than the adhesive layer <NUM> are the same as the insulating glass unit <NUM> according to the first embodiment, the same reference numerals are given to the corresponding components and the description thereof is omitted.

As shown in <FIG>, the adhesive layer <NUM> may be provided in a region S2 that is wider than a region S1 to which the spacer <NUM> is provided. This ensures adhesion between the spacer <NUM> and the glass sheets 1a and 1b. Further, in <FIG>, for ease of understanding, the adhesive layer <NUM> is depicted as a thick layer. However, for example, the thickness t of the adhesive layer <NUM> is <NUM> or less, compared to the spacer having thickness levels of <NUM> and <NUM>, and specifically may be <NUM> to <NUM>. The thickness level of the adhesive layer <NUM> may be in a range of <NUM> to <NUM>, for example, about <NUM>, if the adhesive layer <NUM> is configured to be as thin as possible to the extent that adhesion can be secured. When the thickness t of the adhesive layer <NUM> is formed thinly, the thickness of <NUM> to <NUM> is preferable, and the thickness of <NUM> to <NUM> is more preferable.

Because the thermoplastic resin composition constituting the spacer material is hydrophobic and the glass sheets 1a and 1b are hydrophilic, the adhesiveness of both is required to be secured. However, as long as the adhesiveness of both is secured, various adhesives can be used. For example, a urethane-based adhesive made from a derivative of soft polyolefin-based polyol, a non-yellowing isocyanate and a non-yellowing isocyanate may be used for weather resistance and adhesion. The urethane-based adhesive may contain at least a polyol and an isocyanate, and may also contain a silane coupling agent, if desired, to ensure adhesion with the glass sheet. In addition to the soft polyolefin-based polyol described above, the polyol may be a polyester polyol or a polyacrylic polyol and may be a urethane resin obtained by causing the polyol to react with the non-yellowing isocyanate. The isocyanate may be a yellowish-free isocyanate or a derivative of a yellowish-free isocyanate. Thus, the urethane-based adhesive contains at least one of urethane-based resins obtained by causing a polyester polyol, a polyacrylic polyol, a polyolefinic polyol and polyol to react with the non-yellowing isocyanate, and at least one of the non-yellowing isocyanate and a derivative of the non-yellowing isocyanate, and may optionally further contain a silane coupling agent and the like as necessary. The polyol means a multifunctional alcohol having one or more hydroxyl groups per molecule.

Here, the polyol contained in the urethane-based adhesive preferably has a glass transition point Tg greater than <NUM>. Accordingly, the initial strength at the time of adhesion can be secured, and it is possible to prevent or reduce occurrence of sheet misalignment when the hightemperature butyl-type rubber and the glass sheet are bonded together. Preferably, the molecular weight of the polyol is in a range of <NUM> to <NUM>,<NUM>. This ensures long-term reliability such as heat resistance and weather resistance. In addition, the acid value of the polyol is preferably less than <NUM> KOH mg/g. This ensures the stability and workability of the adhesive solution. The acid value is a number of mg of potassium hydroxide required to neutralize the free fatty acids present in <NUM> of polyol, indicating the degree of purification of the polyol, and the degree of purification increases as the free fatty acids decrease.

Here, the adhesive for bonding the glass sheets 1a and 1b to the resin composition containing the butyl-type rubber used as the material of the spacer <NUM> may be an adhesive composed of (A) a mixture of a terminal reactive oligomer having repeating units of a divalent hydrocarbon group of <NUM> carbon atoms and a compound capable of reacting with the terminal functional group of the oligomer, and (B) a reaction product of a terminal reactive oligomer having repeating units of a divalent hydrocarbon group of <NUM> carbon atoms and a compound capable of reacting with the terminal functional group of the oligomer.

For example, the terminal reactive oligomer having a divalent hydrocarbon group having <NUM> carbon atoms as the repeating unit is a compound containing a repeating unit derived from a hydrocarbon-type monomer having <NUM> carbon atoms and having a reactive functional group at the oligomer terminus such as a hydroxyl group, a carboxyl group, an amino group, a mercapto group, an epoxy group, an isocyanate group and the like. This is a compound that can become a high molecular weight polymer that functions as an adhesive by causing its functional group to react with a compound having a functional group that can react with the functional group, thereby extending a chain or forming a bridge.

The lower limit of the molecular weight of the terminal reactive oligomer is not particularly limited, but is normally about <NUM>. The upper limit is not particularly limited, but is about <NUM>,<NUM>. A molecular weight of <NUM>,<NUM> to <NUM>,<NUM> is preferred, and a molecular weight of <NUM> to <NUM> is particularly preferred. The terminal reactive oligomer is also preferably a substantially linear oligomer. The relatively low molecular weight oligomer may also be branched oligomer, or three or more functional oligomers having a branch with a reactive functional group at each end.

The end-reactive oligomer preferred in the insulating glass <NUM> according to the second embodiment of the invention is a monopolymer of <NUM>-butene, a homopolymer of isoprene, a copolymer of <NUM>-butene and isoprene, a hydride of a monopolymer of butadiene (<NUM>,<NUM>-polybutadiene or <NUM>,<NUM>-polybutadiene), a monomer having <NUM> carbon atoms or more, such as <NUM>-butene, isoprene, and butadiene, a copolymer of pentadiene, styrene, and the like, and its hydride. The most preferred terminal reactive oligomers are a hydride of a homopolymer of butadiene and a homopolymer of isoprene.

The functional group in the terminal reactive oligomer includes hydroxyl, carboxyl, amino, mercapto, epoxy, and isocyanate groups. Hydroxyl or carboxyl groups are preferred, and hydroxyl groups are particularly preferred.

A compound having two or more functional groups capable of reacting with the terminal functional group of the aforementioned oligomer is used as the compound having the functional group capable of reacting with the functional group of the aforementioned terminal reactive oligomer.

For example, the hydroxyl terminal oligomer can react with a chain extending agent made from a polyisocyanate to form polyurethane, and the hydroxyl terminal oligomer can react with a polycarboxylic acid or its acid chloride, an alkyl ester, or the like to form polyester. Similarly, a carboxyl-terminal oligomer can react with polyols, polyamines, polyepoxides and the like, and an aminoterminal oligomer can react with polyepoxides, polycarboxylic acids or anhydrides thereof and the like. A particularly preferred combination of a terminal reactive oligomer and a compound capable of reacting with a terminal functional group of the oligomer in the insulating glass <NUM> according to a second embodiment of the present invention is a combination of a hydroxyl terminal oligomer and a compound made from a polyisocyanate or a polycarboxylic acid or a reactive acid derivative thereof.

Also, the above-described adhesive may be supplemented with a silane coupling agent as necessary. As noted above, the silane coupling agent is used to enhance adhesion to glass.

Examples of the silane coupling agent include an epoxysilane such as <NUM>-glycidoxypropyltrimethoxysilane, <NUM>-glycidoxypropyltriethoxysilane, aminosilane such as <NUM>-aminopropyltrimethoxysilane, <NUM>-aminopropylethoxysilane, <NUM>-triethoxysilyl-N-(<NUM>,<NUM>-dimethylbutyridene)propylamine, and the like.

In addition, an additive such as an antioxidant, a wetting agent, a defoamer and the like and an organic solvent may be added to the adhesive as necessary.

<FIG> is a diagram showing an example of an insulating glass unit <NUM> according to a third embodiment of the present invention. The insulating glass unit <NUM> according to the third embodiment differs from the insulating glass unit <NUM> according to the second embodiment in that a wired glass 1c and a Low-E glass 1d are used as glass sheets. Thus, the insulating glass unit <NUM> according to the third embodiment of the present invention is configured to include a combination of the wired glass 1c and the Low-E glass 1d. The insulating glass unit <NUM> according to the third embodiment is formed as a fire-resistant insulating glass unit <NUM> having improved fire resistance. The wired glass 1c is a glass sheet including a wire mesh <NUM> therein, and the Low-E glass 1d is a glass sheet including a surface coated with a low-radioactivity Low-E metal film <NUM> on the side of the air space layer <NUM>. For example, the thickness of the wired glass 1c may be <NUM> or more and <NUM> or less, <NUM>, or <NUM>. The thickness of Low-E glass 1d may be, for example, <NUM> or more and <NUM> or less, <NUM> or more and <NUM> or less, or <NUM>. However, the thicknesses of the wired glass 1c and the Low-E glass 1d may have various thicknesses depending on the intended use of the insulating glass unit <NUM>.

A spacer <NUM> used for the insulating glass unit <NUM> according to the third embodiment is a spacer having improved fire resistance. The spacer <NUM> described in the first and second embodiments is the highly improved fire-resistant spacer <NUM>, and thus the particularly improved fire-resistant spacer <NUM> can be formed by specifying the type and content of the components shown in the first and second embodiments in more detail.

A fire resistance test will be described before describing the specific configuration of the spacer <NUM>. A fire blocking performance test in accordance with ISO <NUM>-<NUM>:<NUM> is adopted as the fire resistance test. Passing this test is an indicator of the fire resistance properties of an insulating glass unit.

<FIG> is a diagram showing a method of the fire blocking performance test in accordance with ISO <NUM>-<NUM>:<NUM>. As shown in <FIG>, a burner <NUM> and a thermometer <NUM> are provided in a furnace <NUM>, and an insulating glass unit <NUM> to be tested is fixed to an opening <NUM> of the furnace <NUM>. <FIG> is a front view of the furnace <NUM> shown in <FIG>. In the fire blocking performance, the insulating glass unit <NUM> is heated for <NUM> minutes according to the heating curve based on ISO <NUM> (T = <NUM> log10 (8t + <NUM>) + <NUM>, T: furnace inside temperature (°C), t: time (minutes)) as shown in <FIG> and <FIG>.

<FIG> is a diagram showing the heating curve in accordance with ISO <NUM>-<NUM>:<NUM>. The inside of the furnace <NUM> is heated with the burner <NUM> and a fire resistance test is performed on the insulating glass unit <NUM> so that the temperature in the furnace measured by the thermometer <NUM> becomes a temperature gradient as shown in <FIG>.

The insulating glass unit <NUM> passes the fire resistance test when the insulating glass unit <NUM> withstands the fire for <NUM> minutes with no flame penetration and no flame ejection for <NUM> seconds. More accurately, satisfying the following conditions is acceptable: no flame ejection to the non-heated side for longer than <NUM> seconds, no smoke to the non-heated side for longer than <NUM> seconds, and no damage and no gap such as a breakage through which the flame passes. For example, when two sheets of glass 1c and 1d of the insulating glass unit <NUM> collapse, the flame penetrates through the insulating glass unit <NUM>, and when the spacer <NUM> burns and creates a breakage or a gap through which the flame passes, the flame ejection occurs from the four sides of the insulating glass unit <NUM>. Accordingly, the fire resistance of the spacer <NUM> is the key to pass the fire resistance test. The fire resistance tests are conducted on both the front and back sides of the insulating glass unit <NUM>.

<FIG> is a diagram showing a case where the insulating glass unit <NUM> is disposed so that a Low-E glass sheet 1d of the insulating glass unit <NUM> is disposed on the heating side and a wired glass sheet 1c of the insulating glass unit <NUM> is disposed on the non-heated side. In this case, because the wired glass 1c having a strong fire resistance is disposed on the non-heated side, even if the Low-E glass 1d collapses, the wired glass 1c on the non-heated side frequently endures and causes the insulating glass unit <NUM> to pass the tests.

<FIG> is a diagram showing a case where the insulating glass unit <NUM> is disposed so that the Low-E glass sheet 1d of the insulating glass unit <NUM> is disposed on a non-heated side and the wired glass sheet 1c of the insulating glass unit <NUM> is disposed on the heated side. In this case, because the Low-E metal film <NUM> of the Low-E glass sheet 1d reflects heat inward the furnace <NUM>, the wired glass sheet 1c is heated at a faster rate than in the case of <FIG>. If the inside of the spacer <NUM> burns and the wired glass sheet 1c collapses, because the Low-E glass sheet 1d is not as fire-resistant as the wired glass sheet 1c, the flame frequently penetrates the insulating glass unit <NUM>. That is, the arrangement pattern shown in <FIG> is prone to rejection due to the configuration. Passing the fire resistance test in the arrangement of <FIG> requires that the heat resistance of the spacer <NUM> be increased and that the collapse of the wired glass sheet 1c be prevented as much as possible.

In order to increase the fire resistance property of the spacer <NUM>, it is necessary to use a highly fire-resistant material as the material forming the spacer <NUM>. Examples of the highly fire-resistant materials include materials unlikely to be burned, and also include materials having many pores and capable of absorbing methane and carbon monoxide that are combustible gases, and of inhibiting the combustion of the spacer <NUM>. Although the spacer <NUM> is initially used in a dry state, the use of the insulating glass unit <NUM> gradually causes the pores to include moisture therein. In the fire resistance test, heating serves to releases the moisture in the pores therefrom and serves as a coolant.

In the insulating glass unit <NUM> in accordance with this embodiment, as a material of the spacer <NUM>, a material having many such pores is used to improve the fire resistance of the spacer <NUM>. The pore size is preferably <NUM> or more. In addition, the pore size is preferably <NUM> or less, more preferably <NUM> or less, and more and more preferably <NUM> or less.

As a specific material, the first and second embodiments have described that a desiccant such as zeolite, silica gel, or alumina may be added to the resin composition as the material forming the spacer <NUM>. However, in the third embodiment, a spacer <NUM> having a desiccant combined with the resin composition is used. As the desiccant, any of zeolite, silica gel, or alumina may be used, and preferably zeolite is used. As the desiccant, a powdered material may be used, and a powder having a particle size in a range that does not reach the fine particles may be used. For example, preferably, the particle size of the desiccant is <NUM> or less for the median diameter d50, further preferably <NUM> or less, and even more preferably <NUM> or less. For example, the particle size of the desiccant is preferably <NUM> or more and <NUM> or less of the median diameter d50, more preferably <NUM> or more and <NUM> or less, and even more preferably <NUM> or more and <NUM> or less. For example, a zeolite of <NUM> to <NUM> with a median diameter d50 may be used as a desiccant.

In the first and second embodiments, carbon black may be added to the resin composition forming the spacer <NUM> as an inorganic filler. Preferably, the spacer <NUM> of the insulating glass unit <NUM> according to the third embodiment contains carbon black. Carbon black has a very large nitrogen specific surface area and is considered to have a large trapping effect on the particles of combustion gases such as methane and carbon monoxide.

Among carbon blacks, hard carbon type carbon black is preferred for fire protection use because of its relatively large surface area. The nitrogen specific surface area of the carbon black is preferably <NUM><NUM>/g or more and <NUM><NUM>/g or less, more preferably <NUM><NUM>/g or more and <NUM><NUM>/g or less, and even more preferably <NUM><NUM>/g or more and <NUM><NUM>/g or less. The hard carbon-type carbon black is more preferably HAF-type.

Talc may be included in the resin composition of the spacer <NUM> as an inorganic filler in the first and second embodiments, and the spacer <NUM> of the insulating glass unit <NUM> according to the third embodiment also preferably contains talc. Talc is also an incombustible particulate material. For example, the particle diameter of talc is preferably <NUM> or more and <NUM> or less at the median diameter d50, more preferably <NUM> or more and <NUM> or less, and even more preferably <NUM> or more and <NUM> or less.

When the spacer <NUM> is heated to <NUM> under an air atmosphere, the residual mass is preferably <NUM>% or more and <NUM>% or less, further preferably <NUM>% or more and <NUM>% or less, and even more preferably <NUM>% or more and <NUM>% or less.

In addition, preferably, the outer end surface of the spacer <NUM> is disposed so as to be positioned inward for <NUM> or more from the end surface of the wired glass sheet 1c and the Low-E glass sheet 1d. The distance of the outer end face of the spacer <NUM> from the end face of the wired glass sheet 1c and the Low-E glass sheet 1d is preferably <NUM> or more, more preferably <NUM> or more, and more and more preferably <NUM> or more. For example, the distance of the outer end face of the spacer <NUM> from the end face of the wired glass sheet 1c and the Low-E glass sheet 1d may be set to a predetermined distance ranging from <NUM> to <NUM>. This is also true for the insulating glass units <NUM> and <NUM> according to the first and second embodiments.

The same adhesive may be used as the adhesive described in the second embodiment. For example, a urethane-based adhesive made of a polyolefin-based polyol, a non-yellowing isocyanate, and a derivative of a non-yellowing isocyanate may be used. Because these adhesives are cross-linked adhesives that do not melt, the adhesives have properties that do not melt even when heated and that remain in the place, thereby improving the fire resistance performance of the insulating glass unit <NUM>.

In the third embodiment, the insulating glass unit <NUM> having the same configuration as the second embodiment including the adhesive layer <NUM> has been described. However, in the same manner as in the first embodiment, the insulating glass unit <NUM> may be formed without the adhesive layer. However, because providing the adhesive layer <NUM> makes it easier to pass the fire resistance test, the adhesive layer <NUM> is preferably provided.

In addition, the additives described in the third embodiment are preferably added to the thermoplastic resin composition as many types as possible, and preferably all kinds of the additives are added.

According to a third embodiment, by adding additives having a configuration capable of trapping a combustion gas such as pores, to the resin composition forming the spacer <NUM>, it is possible to form an insulating glass unit <NUM> that can improve fire resistance performance and can pass the fire resistance test defined by ISO <NUM>-<NUM>:<NUM>.

Next, a method of manufacturing the insulating glass units <NUM>, <NUM>, and <NUM> according to the first, second, and third embodiments will be described.

In a kneading process, butyl type rubber, a crystalline polyolefin and an inorganic filler, and a desiccant are uniformly kneaded and dispersed at a temperature of <NUM> to <NUM> for a time period ranging from <NUM> minutes to <NUM> hours to provide a thermoplastic resin composition for a spacer with JIS A hardness of <NUM> to <NUM>. In order to obtain the thermoplastic resin composition for the spacer <NUM> of the insulating glass unit <NUM> according to the third embodiment, an inorganic filler and a desiccant that satisfy the conditions described in the third embodiment are added.

As the kneading time increases, the dispersion degree of the thermoplastic resin composition improves; the roughness of the spacer of the insulating glass unit decreases, the adhesiveness between the spacer and the glass sheet improves; and the long-term reliability of the insulating glass unit improves, which are preferable. More specifically, the kneading time is <NUM> minutes or more, and even more preferably, <NUM> minutes or more. In order to reduce the manufacturing time of the insulating glass unit, the kneading time is preferably <NUM> hours or less, <NUM> hours or less, and <NUM> hours or less, respectively.

In addition, preferably, the thermoplastic resin composition is manufactured by mixing the butyl type rubber and the crystalline polyolefin at least as described above at a temperature not less than the crystalline melting point of the crystalline polyolefin and not more than the decomposition point of the butyl type rubber. The mixing temperature is <NUM> to <NUM>, and particularly preferably <NUM> to <NUM>. Other formulations and additives may be mixed at the same time, either before or after mixing. Mixing at <NUM> to <NUM> improves the dispersion degree of the resin composition, improves the adhesion of the spacer of the insulating glass unit to the glass sheets, and enhances the long-term reliability of the insulating glass unit.

The compositions of the present invention are substantially thermoplastic compositions that can be mixed in a mixer such as a conventional melt mixing extruder and a kneader. In addition, molding may be carried out in succession with the above mixing operation. The composition can be also manufactured into a molding material, such as a pellet, followed by molding. A melt molding method, such as extrusion or injection molding, can be used for molding.

In addition, the insulating glass unit can be manufactured by placing the molded product at the end of an insulating glass material in which two or more glass sheets are disposed opposite to each other in succession to the molding operation. In this case, by using the high temperature composition extruded from the molding machine, a high adhesiveness with the glass sheets can be obtained. Apparatuses such as applicators can be also applied to the insulating glass materials while controlling the temperature drop of the composition. Preferably, the device has a heating function.

<FIG> is a diagram illustrating an example of a glass plate arrangement process. In the glass plate arrangement process, two glass plates 1a and 1b, or 1c and 1d are arranged facing each other. When the insulating glass units <NUM>, <NUM> according to the second and third embodiments are manufactured, a process of applying an adhesive to the region where the spacer <NUM> is provided and then forming an adhesive layer <NUM> is provided prior to this step. As shown in <FIG> and <FIG>, as necessary, the adhesive layer <NUM> may be optionally provided in a region larger than the spacer <NUM>, <NUM> that is, a region containing the spacer <NUM>, <NUM> and further larger than the spacer <NUM>, <NUM>, or alternatively may be formed in a region smaller than the spacer <NUM>, <NUM>. Moreover, it goes without saying that the adhesive layer <NUM> may be formed in the same region as the spacer <NUM>, <NUM>. After the adhesive is air-dried, the two glass plates 1a and 1b are held at a predetermined distance (for example, <NUM> and <NUM>) as shown in <FIG>. However, the distance between the two glass plates 1a and 1b can be determined according to the application and is not limited thereto.

On the other hand, when the insulating glass <NUM> according to the first embodiment is manufactured, the two glass plates 1a and 1b, which are not coated with any coating, are disposed facing each other at a predetermined distance. This is the same as the case where the adhesive layer <NUM> is not provided in the third embodiment.

Next, the above-mentioned thermoplastic composition is formed by melting the thermoplastic composition at a temperature of, for example, <NUM> or less, for example, at a predetermined temperature in a range of <NUM> to <NUM>, while using a general-purpose extruder having a cylinder of suitable diameter as shown in <FIG>, and by disposing the thermoplastic composition between the two glass sheets while extruding the thermoplastic composition from a die having a suitable tip shape. A typical extruder may be used as the extruder, and the extruder may have a configuration, as shown in <FIG>, such that a molten thermoplastic composition is fed from a hopper <NUM> and the molten thermoplastic composition fed into a barrel <NUM> is pushed forward by a screw <NUM> and extruded from a tip die <NUM> into a predetermined region.

Herein, in the conventional forming process, a spacer material has high viscosity, and thermoplastic resin composition needs to be heated to a high temperature of about <NUM> or more. However, the thermoplastic resin composition used in the insulating glass unit <NUM>, <NUM> and <NUM> in accordance with the present embodiment is configured to be able to be processed by extrusion molding at a temperature of <NUM> or less, so that a predetermined region between two glass sheets 1a and 1b can be filled with the spacer <NUM>, <NUM> at a low temperature and extrusion molding can be performed. After the molten thermoplastic composition is fed into the predetermined region between the glass sheets 1a and 1b, the two glass sheets 1a and 1b are pressurized from the outside, and the two glass sheets 1a and 1b are fixed. The thermoplastic resin composition is then cooled and solidified to form the spacer <NUM>. This completes the insulating glass unit <NUM>, <NUM> and <NUM>, as shown in <FIG> or <FIG>. In addition, because the thermoplastic resin composition is already at a high temperature during pressurization, it need not be heated or may be further heated.

The method of double-grazing is only an example, and the method of manufacturing the insulating glass unit according to the present invention is not limited to the above-described method. For example, a spacer having a desired shape may be molded from the resin composition in advance, and the spacer may be bonded by thermal compression bonding, for example, with two sheets of glass.

Hereinafter, working examples of producing insulating glass according to the present embodiments will be described.

<FIG> shows Composition Examples <NUM> to <NUM> (<NUM> and <NUM> for reference only) corresponding to Examples and Reference Examples and Comparative Examples <NUM> and <NUM>. Each value represents a mass proportion with respect to <NUM> parts by mass. As for the butyl type rubber, four types of butyl type rubber having different number-average molecular weights are used. Therefore, the composition including each type is shown.

<FIG> is a diagram showing an overall composition shown in <FIG> converted into a percentage of butyl-type rubber and crystalline polyolefin. <FIG> is a diagram showing an overall composition shown in <FIG> by converting a proportion of the inorganic filler with respect to the total <NUM> parts by weight of the butyl-type rubber and the crystalline polyolefin. <FIG> and <FIG> are shown to facilitate comparison with the claims.

In <FIG>, the high molecular weight butyl-type rubber PIB-A shows the polyisobutylene having the number average molecular weight Mn of <NUM>; the high molecular weight butyl-type rubber IIR shows the butyl-type rubber having the number average molecular weight Mn of <NUM>; the low molecular weight butyl-type rubber PIB-B shows the polyisobutylene having the number average molecular weight Mn of <NUM>; and the low molecular weight butyl-type rubber PIB-C shows the polyisobutylene having the number average molecular weight Mn of <NUM>.

The number average molecular weights Mn of these butyl-type rubbers were measured using a THF solvent and a polystyrene standard sample using a size exclusion chromatography device manufactured by Tosoh Corporation (main body: HLC-<NUM> GPC, RI detector guard column: TSKgen guard column SuperHZ-L, column: TSKgen SuperHZ2000, TSKgel SuperHZ2500, and TSKgel SuperHZ4000).

As for crystalline polyolefins, HDPE shows a high density polyethylene with a melting point of <NUM> at a melt flow rate MFR of <NUM> / <NUM> (according to JIS K6922-<NUM>). Also, LDPE shows low density polyethylene with a melting point of <NUM> at a melt flow rate MFR of <NUM>/<NUM> (according to JIS K6922-<NUM>). LDPE LC701 also exhibits low density polyethylene with a melting point of <NUM> at a melting flow rate MFR of <NUM>/<NUM> (according to JIS K6922-<NUM>). Furthermore, the modified PE has a melting point of <NUM> with a melt flow rate MFR of <NUM> / <NUM> (according to JIS K6922-<NUM>), indicating polyethylene with an introduced acid anhydride and acrylic acid ester.

As for the tackifier, a DCPD (dicyclopentadiene) type hydrogenated hydrocarbon resin with a softening point of <NUM> was used.

As for the inorganic filler, an inorganic filler containing talc having an average particle size of <NUM> and high abrasion furnace type carbon black was used.

A 4A type zeolite powder was used as a desiccant. Phenol type antioxidants were used as an additive.

The composition shown in <FIG>, was uniformly kneaded at a temperature of <NUM> to <NUM> for a time ranging from <NUM> minutes to <NUM> hours, and a thermoplastic resin composition for spacers with JIS A hardness of <NUM> to <NUM> was obtained.

Next, the results of the evaluation of the insulating glass using the resin compositions for spacers of Examples <NUM> to <NUM> (<NUM> and <NUM> for reference only) and Comparative Examples <NUM> and <NUM> described above are shown.

In any example, the thermoplastic resin composition of the spacer material was extruded using a rubber extruder having a cylinder with a diameter of <NUM> to maintain a <NUM> or <NUM> distance between two float glass sheets of size <NUM> * <NUM>, <NUM> or <NUM> in thickness, with a spacer extruded on the outer periphery of the glass sheets to obtain the insulating glass <NUM> having the configuration shown in <FIG>.

<FIG> is a table showing Composition Examples <NUM> to <NUM> (<NUM> and <NUM> for reference only) corresponding to Examples <NUM> to <NUM> (<NUM> and <NUM> for reference only) and the evaluation results of Comparative Examples <NUM> and <NUM>.

The evaluation method of the evaluation items shown in <FIG> is as follows.

The dispersion degree was measured according to the ISO <NUM>:<NUM> E method using a Disper-Tester <NUM> rubber filler testing machine manufactured by Montech.

As for the adhesiveness, the interface between the glass sheet and the spacer was observed, and a case where there was no gap (bubble) between the glass sheet and the spacer was made acceptable, and a case where there was a gap (bubble) was made unacceptable.

The loss tangent of a sample having a diameter of <NUM> and a thickness of <NUM> was measured in a shear mode, at <NUM>, and at a deformation amount of <NUM>% with a sample shape according to JIS K <NUM>:<NUM> using the rheometer MCR <NUM> manufactured by Anton Paar GmbH.

As for melt viscosity, Capillogragh 1C manufactured by Toyo Seiki Seisaku-sho, Ltd. As for capillary, capillary length of <NUM> and capillary diameter of <NUM> were used. As for a furnace, a furnace having a furnace body diameter of <NUM> was used. The melt viscosity at a temperature of <NUM> and a shear rate of <NUM>/s was used as the reference. Acceptance was defined as <NUM> kPa·s or more and <NUM> kPa·s or less.

As for the storage modulus (dynamic elastic modulus), DVA-<NUM>, a dynamic viscoelasticity measuring device manufactured by IT Measuring Co. , was used, and a tensile test was conducted in which the temperature was raised at <NUM>/min in a constant-speed temperature rising mode; for a sample with length between grips of <NUM>; the width of <NUM>; and the thickness of <NUM>; where the deformation was <NUM>%; the static/dynamic ratio was <NUM>; and the frequency was <NUM>. The storage elastic modulus at a temperature of <NUM> was used as a reference. A value of <NUM> MPa or more and <NUM> MPa or less was considered acceptable.

As for sheet misalignment test, the obtained glass sheet of one side of each insulating glass was fixed, and the load of <NUM> was applied to the other glass sheet, and the downward displacement of the glass sheet of the load bearing side was measured under the temperature conditions of <NUM>. The displacement of <NUM> or less in <NUM> minutes was considered acceptable.

Accelerated durability tests were performed on insulating glass with a <NUM> thick spacer in accordance with JIS R <NUM>. JIS <NUM> classification determinations were recorded.

Dew point measurements were performed according to the apparatus and method described in JIS R3209.

As shown in <FIG>, as for Examples <NUM> to <NUM> (<NUM> and <NUM> for reference only), the dispersion degree was <NUM>% or more and the adhesiveness was acceptable. In contrast, in Comparative Examples <NUM> to <NUM>, the dispersion degree was less than <NUM>%, and the adhesiveness was unacceptable. Thus, the results indicate that the insulating glass unit <NUM> according to Examples <NUM> to <NUM> (<NUM> and <NUM> for reference only) has higher dispersion degrees than those of the insulating glass units according to Comparative Examples <NUM> to <NUM> and achieves the insulating glass unit <NUM> having an improved adhesiveness.

As for the insulating glass unit of Example <NUM>, a fire resistance test was also conducted in accordance with ISO <NUM>-<NUM>:<NUM>. That is, the spacer having a composite described in Example <NUM>, a wired glass sheet, and a Low-E glass sheet were used to form the insulating glass unit <NUM>.

The size of the insulating glass unit was <NUM> × <NUM>. The glass structure was as follows: a wired glass sheet of6. <NUM>, an air space layer of <NUM>, and a Low-E (Low Emissivity) glass sheet of <NUM> disposed from the heated surface side. The overall configuration of the insulating glass unit is the same as that of <FIG>.

Zeolite used for the spacer had a particle size of <NUM> to <NUM> for the median diameter d50, a nitrogen specific surface area of <NUM> to <NUM><NUM>/g for carbon black, a particle size of <NUM> for the median diameter d50, and a residual mass was <NUM>% when the spacer was heated to <NUM>.

As described in <FIG>, a <NUM>-minute fire blocking performance test was performed according to ISO <NUM>-<NUM>:<NUM>. The test was performed according to the layout pattern likely to be unacceptable shown in <FIG>.

Acceptance criteria included no flame ejection to the non-heated side for more than <NUM> seconds, no flame to the non-heated side for more than <NUM> seconds, and no damage or clearance, such as a breakage through which flames can pass.

In Comparative Example <NUM>, a commercially available "Naftsarme (TM) BU-TPS" (manufactured by ift Rosenheim) was used as a spacer <NUM>. The spacer is mainly formed of butyl type rubber.

As shown in <FIG>, an insulating glass unit was produced having a configuration including a spacer <NUM> mainly made of a butyl type rubber disposed on the central side and a secondary seal <NUM> disposed on the outside so as to surround the spacer <NUM>. A polysulfide (SM9000) manufactured by The Yokohama Rubber Co. was used as the secondary seal <NUM>.

Similar to Example <NUM>, the size of the insulating glass unit was made <NUM> × <NUM>. The glass structure was constituted of a wired glass sheet of <NUM>, an air space layer of <NUM>, and a Low-E glass sheet of <NUM> disposed from the heated surface side.

Testing and acceptance conditions were made the same as those of Example <NUM>, and a <NUM>-minute fire blocking performance test was performed according to ISO <NUM>-<NUM>:<NUM>.

The Low-E glass sheet was damaged and dropped at <NUM> minutes and <NUM> seconds, and the test result was unacceptable.

In Comparative Example <NUM>, a commercially available SWISSPACER (Registered Trade Mark) manufactured by Saint-Gobain K. was used as the spacer. The main component of the spacer was resin.

As shown in <FIG>, an insulating glass unit was produced in a configuration including a resin-based spacer <NUM> and a primary seal <NUM> disposed on the central side, and a secondary seal <NUM> so as to surround the outer side of the primary seal <NUM>. The inside of the spacer <NUM> is filled with a desiccant <NUM>. As the primary seal <NUM>, an SM <NUM> manufactured by The Yokohama Rubber Co. was used, and a polysulfide (SM <NUM>) manufactured by The Yokohama Rubber Co. was used as the secondary seal <NUM>.

Testing and acceptance conditions were the same as those in Example <NUM>, and a <NUM>-minute fire blocking performance test was performed according to ISO <NUM>-<NUM>:<NUM>.

Thus, the insulating glass sheet in accordance with Example <NUM> passed the fire blocking performance test and demonstrated an improved fire retardance performance.

Claim 1:
An insulating glass unit including two or more glass sheets disposed to face each other via a spacer interposed between the glass sheets so as to form an air space layer between the glass sheets, characterized in that
the spacer is formed of a thermoplastic resin composition having a JIS A hardness of <NUM> to <NUM> at <NUM>, the thermoplastic resin composition containing a butyl type rubber, a crystalline polyolefin, a desiccant and an inorganic filler,
a percentage of the butyl type rubber is <NUM> to <NUM> mass%, and a percentage of the crystalline polyolefin is <NUM> to <NUM> mass% with respect to a total amount of the butyl type rubber and the crystalline polyolefin,
a proportion of the inorganic filler is <NUM> parts by mass or less with respect to a total of <NUM> parts by mass of the butyl type rubber and the crystalline polyolefin, and
a percentage of dispersion defined by ISO <NUM>:<NUM> E method is <NUM>% or more,
wherein the butyl type rubber contains a high molecular weight butyl type rubber and a low molecular weight butyl type rubber,
the high molecular weight butyl type rubber has a number average molecular weight of <NUM> or more and <NUM> or less, and
the low molecular weight butyl type rubber has a number average molecular weight of <NUM> or more and <NUM> or less.