Patent Description:
A silicone (polyorganosiloxane) composition such as silicone rubber or silicone gel forms a cured product excellent in various characteristics such as weather resistance, heat resistance, hardness, elongation and so on, and therefore is used for various applications.

For example, in an LED device including a light emitting element such as a light emitting diode (LED), a polyorganosiloxane composition excellent in heat resistance, ultraviolet resistance characteristics and so on is used as a material that seals the light emitting element and a material that forms a lens to be disposed in an optical path from the light emitting element. In particular, an addition reaction type polyorganosiloxane composition cured by hydrosilylation is cured in a short time by heating and produces no bi-product when curing, and is therefore widely used as a sealant or the like for the LED device.

However, a conventional addition reaction type polyorganosiloxane composition is low in adhesiveness and, in particular, insufficient in adhesiveness to noble metals such as silver (Ag), gold (Au) and the like used as a frame and electrodes of the LED device and to heat-resistant plastic such as PPA and the like used as a reflector and a support substrate. Therefore, it is performed to add a silane compound having an epoxy group such as γ-glycidoxypropylmethyldimethoxysilane or γ-glycidoxypropyltrimethoxysilane to an addition reaction type polyorganosiloxane composition so as to improve adhesiveness (for example, refer to Patent Reference <NUM>).

However, the silane compound has a low molecular weight and is likely to volatilize, and therefore evaporates due to heating in a process of forming a sealing layer or the like by molding and curing the polyorganosiloxane composition. Further, even after the formation of the sealing layer, the silane compound is likely to volatilize due to heat generation from the light emitting element, heating in application of the temperature cycle and so on, and to be lost from the sealing layer. Therefore, the adhesiveness of the sealing layer decreases, and peeling occurs between the base material such as PPA or the like and the sealing layer.

Further, there is also proposed a polyorganosiloxane composition for the LED device containing, as an adhesiveness imparting component, a silane coupling agent, a siloxane having a hydrosilyl group and/or an alkoxysilyl group, and an organofunctional group such as a (meth)acryloxy group or an epoxy group (for example, refer to Patent Reference <NUM>). However, this composition is also insufficient in long-term adhesiveness to PPA or the like.

Also Patent Reference <NUM> discloses an adhesiveness imparting agent comprising a polyorganosiloxane containing a siloxane T unit presenting an alkyl glycidoxy group and a siloxane D unit presenting an alkenyl group; and a curable composition for a LED device comprising this agent.

The present invention has been made to solve such problems in the prior art and an object is to provide an adhesiveness imparting agent to be compounded to improve adhesiveness to heat-resistant plastic such as PPA in a composition of a polyorganosiloxane or the like. Another object is to provide an adhesive polyorganosiloxane composition having excellent adhesiveness to the heat-resistant plastic or the like and never decreasing in adhesiveness due to heat generation from a light emitting element, and heating in a temperature cycle or the like, and suitable as a sealant or the like for an optical semiconductor device.

An adhesiveness imparting agent of the present invention comprises a polyorganosiloxane, the polyorganosiloxane containing: (a) at least one kind of siloxane unit having an epoxy group selected from a group consisting of a trifunctional siloxane unit represented by a formula: R<NUM>SiO<NUM>/<NUM> (in the formula, R<NUM> representing an epoxyalkyl group or a glycidoxyalkyl group;.

Further, an adhesive polyorganosiloxane composition of the present invention comprises: (A) <NUM> parts by mass of a polyorganosiloxane having an alkenyl group bonded to a silicon atom; (B) a polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom in such an amount that an amount of the hydrogen atom in the component becomes <NUM> to <NUM> per alkenyl group in the (A) component; (C) a catalytic amount of a platinum-based catalyst; and (D) <NUM> to <NUM> parts by mass of the adhesiveness imparting agent of the present invention.

An optical semiconductor device of the present invention comprises a cured product made by curing the adhesive polyorganosiloxane composition of the present invention.

Note that in the following description, an "alkenyl group bonded to a silicon atom" is sometimes referred to as an "alkenyl group. " Further, a "hydrogen atom bonded to a silicon atom" is sometimes referred to as a "hydrogen atom.

The adhesiveness imparting agent of the present invention, when compounded in the polyorganosiloxane composition or the like, can improve adhesiveness to the heat-resistant plastic such as PPA. Further, the adhesiveness imparting agent never volatilizes to be lost from the compounded composition due to heating when curing, heat generation from the light emitting element after the curing, heating in a temperature cycle, or the like, and therefore never decreases in adhesiveness.

Further, the adhesive polyorganosiloxane composition of the present invention has excellent adhesiveness to the heat-resistant plastic such as PPA and the excellent adhesiveness never decreases due to a temperature increase caused from heat generation or application of a temperature cycle or the like. Accordingly, the optical semiconductor device such as an LED device, in which the sealing layer is formed of the cured product of the polyorganosiloxane composition, is excellent in adhesiveness between the sealing layer and a plastic base material so that peeling hardly occurs at the boundary face between them, and is high in reliability.

<FIG> is a graph illustrating a profile of an increased temperature for investigating adhesiveness in a package test (<NUM>) for polyorganosiloxane compositions obtained in Examples <NUM> to <NUM> and Comparative Examples <NUM>, <NUM>.

A first embodiment of the present invention is an adhesiveness imparting agent including a polyorganosiloxane containing (a) a siloxane unit having an epoxy group; (b) a bifunctional siloxane unit having an alkenyl group; a trifunctional siloxane unit represented by a formula R<NUM>SiO<NUM>/<NUM>, where R<NUM> represents an alkyl group; and a bifunctional siloxane unit represented by a formula R<NUM><NUM>SiO<NUM>/<NUM>, where R<NUM> represents an alkyl group; in which a weight-average molecular weight (hereinafter, referred to as Mw) is <NUM> to <NUM>.

Here, the (a) siloxane unit having an epoxy group is a trifunctional siloxane unit represented by a formula (<NUM>): R<NUM>SiO<NUM>/<NUM>, where R<NUM> represents an epoxyalkyl group or a glycidoxyalkyl group.

The (b) bifunctional siloxane unit having an alkenyl group is a unit represented by a formula (<NUM>): R<NUM><NUM>SiO<NUM>/<NUM>. Note that in the formula (<NUM>), R<NUM> represents a monovalent hydrocarbon group selected from a group consisting of an alkenyl group and an alkyl group, and at least one of the two R<NUM> is an alkenyl group.

The polyorganosiloxane as claimed containing the (a) siloxane unit having an epoxy group and the (b) bifunctional siloxane unit having an alkenyl group, and having an Mw in the above-describe range, when compounded into an addition reaction type polyorganosiloxane composition containing a polyorganosiloxane having an alkenyl group in a molecule as a base polymer and a polyorganohydrogensiloxane having a hydrogen atom in a molecule, is excellent in compatibility with the base polymer and uniformly mixed, in which the alkenyl group in the bifunctional siloxane unit reacts with the hydrogen atom of the polyorganohydrogensiloxane contained in the composition when the composition is cured, and is combined to the base polymer through the reaction. Therefore, the polyorganosiloxane in the first embodiment is never lost due to volatilization by heat generation when heat curing the composition and after the curing, heating in a temperature cycle or the like, and therefore exhibits high adhesiveness derived from the epoxy group with respect to noble metals such as gold and silver and plastics such as PPA.

Hereinafter, the siloxane units constituting the polyorganosiloxane being the adhesiveness imparting agent in the first embodiment will be further described.

The (a) siloxane unit having an epoxy group is at least one kind of siloxane unit selected from a group consisting of the trifunctional siloxane unit (hereinafter, referred to as a T1ep unit) represented by the formula (<NUM>): R<NUM>SiO<NUM>/<NUM>, as claimed.

R<NUM> represents an epoxyalkyl group, or a glycidoxyalkyl group. From the view point of easiness to synthesize the polyorganosiloxane being the adhesiveness imparting agent, R<NUM> is preferably a glycidoxyalkyl group, and particularly preferably γ-glycidoxypropyl group.

The (a) siloxane unit having an epoxy group includes at least the T1ep unit so that the adhesiveness imparting agent to be obtained (polyorganosiloxane) is less likely to volatilize.

The (b) bifunctional siloxane unit having an alkenyl group is a unit represented by the formula (<NUM>): R<NUM><NUM>SiO<NUM>/<NUM>. Note that in the formula (<NUM>), R<NUM> represents a monovalent hydrocarbon group selected from an alkenyl group and an alkyl group , and at least one of the two R<NUM> is an alkenyl group. Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group and so on, and the vinyl group is more preferable. The group other than the alkenyl group in R<NUM> is preferably an alkyl group, and particularly preferably a methyl group. Hereinafter, the bifunctional siloxane unit having an alkenyl group represented by the formula (<NUM>) is referred to as a D1vi unit.

The polyorganosiloxane being the adhesiveness imparting agent contains the (a) T1ep unit and the (b) D1vi unit, and further contains a trifunctional siloxane unit represented by a formula (<NUM>): R<NUM>SiO<NUM>/<NUM> and a bifunctional siloxane unit represented by a formula (<NUM>): R<NUM><NUM>SiO<NUM>/<NUM>.

In the formulas (<NUM>) and (<NUM>), R<NUM> represents an alkyl group. R<NUM> is preferably a methyl group. Hereinafter, the trifunctional siloxane unit represented by the formula (<NUM>) is referred to as a T1 unit, and the bifunctional siloxane unit represented by the formula (<NUM>) is referred to as a D1 unit.

In the polyorganosiloxane being the adhesiveness imparting agent, the composition ratio of the siloxane units, namely, the molar ratio with a unit having a epoxy group, the unit being at least one kind selected from the (a) T1ep unit (hereinafter, referred to as a T1ep unit, the (b) D1vi unit, and the other units (the T1 unit and the D1 unit) is not particularly limited, but the ratio of the (a) T1ep unit is preferably set to <NUM> to <NUM> mol% of all units from the viewpoint of imparting adhesiveness to a polyorganosiloxane composition. Further, the ratio of the (b) D1vi unit is preferably set to <NUM> to <NUM> mol% of all units from the viewpoint of reactivity to the addition reaction type polyorganosiloxane composition.

The adhesiveness imparting agent in the first embodiment can be prepared, for example, by the following method.

Specifically, at least one kind of silane compound having an epoxy group, selected from a trifunctional silane represented by a formula: R<NUM>Si(OR<NUM>)<NUM>, a silane compound having an alkenyl group represented by a formula: R<NUM><NUM>Si(OR<NUM>), a trifunctional silane represented by a formula: R<NUM>Si(OR<NUM>)<NUM> and a bifunctional silane represented by a formula: R<NUM><NUM>Si(OR<NUM>)<NUM> are charged into a reaction container, the liquid is made basic and heated, and subjected to partial hydrolysis and then condensation reaction.

In the above formula, R<NUM> represents a monovalent organic group having an epoxy as claimed, R<NUM> represents a monovalent hydrocarbon group selected from an alkenyl and an alkyl group, and R<NUM> represents an alkyl group, As those groups, the same groups as described above can be exemplified. Preferable groups are also the same as described above.

Then, alcohol is distilled off from the obtained reaction mixture, and then the liquid is neutralized. Thereafter, a low-molecular weight component is removed from the reaction mixture, and solvent removal and concentration are performed, whereby the polyorganosiloxane being the adhesiveness imparting agent in the first embodiment can be obtained.

The Mw of the polyorganosiloxane thus obtained is set to a range of <NUM> to <NUM>. When the Mw of the polyorganosiloxane is less than <NUM>, the polyorganosiloxane is likely to volatilize in a heating process when curing the polyorganosiloxane composition having the adhesiveness imparting agent compounded therein, or heat generation after the curing, heating in a temperature cycle or the like, resulting in a decrease in adhesiveness. When the Mw is more than <NUM>, the polyorganosiloxane is difficult to uniformly compound into the composition, thus it is hardly producing an effect of improving the adhesiveness.

A second embodiment of the present invention is an adhesive polyorganosiloxane composition containing (A) <NUM> parts by mass of a polyorganosiloxane having an alkenyl group, (B) a polyorganohydrogensiloxane having a hydrogen atom in such an amount that the amount of the hydrogen atom in this component becomes <NUM> to <NUM> per alkenyl group in the (A) component, (C) a catalytic amount of a platinum-based catalyst, and (D) <NUM> to <NUM> parts by mass of the adhesiveness imparting agent in the first embodiment of the present invention.

Hereinafter, the components will be described.

The polyorganosiloxane having an alkenyl group being the (A) component is a base polymer of the adhesive polyorganosiloxane composition as the second embodiment of the present invention. It is preferable to be a polyorganosiloxane having two or more alkenyl groups in one molecule.

Examples of a molecular structure of the (A) component include linear, cyclic structures and so on. The linear, cyclic structures and so on may have a branch, and a linear structure is preferable which has a main chain basically composed of repeated diorganosiloxane units and has both molecular chain terminals blocked with triorganosiloxy groups.

Examples of the alkenyl group bonded to a silicon atom in the (A) component include the ones having a number of carbon atoms of <NUM> to <NUM>, such as a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group and so on, preferably the ones having a number of carbon atoms <NUM> to <NUM>. The vinyl group is particularly preferable. In the case where the polyorganosiloxane having an alkenyl group being the (A) component is linear, the alkenyl group may be bonded to a silicon atom only at one of the terminal and the middle of a molecular chain, and may be bonded to a silicon atom at both of the terminal and the middle of a molecular chain.

Examples of the organic group bonded to the silicon atom other than the alkenyl group in the (A) component include unsubstituted or halogen-substituted monovalent hydrocarbon groups such as: alkyl groups, in particular, alkyl groups having a number of carbon atoms of <NUM> to <NUM>, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a heptyl group; aryl groups, in particular, aryl groups having a number of carbon atoms of <NUM> to <NUM>, such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; aralkyl groups such as a benzyl group and a phenethyl group; and halogenated alkyl groups such as a chloromethyl group, a <NUM>-chloropropyl group, and a <NUM>,<NUM>,<NUM>-trifluoropropyl group. The methyl group or the phenyl group is particularly preferable.

The viscosity (<NUM>) of the (A) component except a later-described polyorganosiloxane AA is preferably <NUM> to <NUM>,<NUM> mPa·s, and particularly preferably within a range of <NUM> to <NUM>,<NUM> mPa·s. When the viscosity (<NUM>) of the (A) component is within this range, workability of the composition to be obtained is excellent, and physical properties of a cured product to be obtained from this composition are also excellent.

Concrete examples of the (A) component include a dimethylsiloxane methylvinylsiloxane copolymer with both molecular chain terminals blocked with trimethylsiloxy groups, a methylvinylpolysiloxane with both molecular chain terminals blocked with trimethylsiloxy groups, a dimethylsiloxane methylvinylsiloxane methylphenylsiloxane copolymer with both molecular chain terminals blocked with trimethylsiloxy groups, a dimethylpolysiloxane with both molecular chain terminals blocked with dimethylvinylsiloxy groups, a methylvinylpolysiloxane with both molecular chain terminals blocked with dimethylvinylsiloxy groups, a dimethylsiloxane methylvinylsiloxane copolymer with both molecular chain terminals blocked with dimethylvinylsiloxy groups, a dimethylsiloxane methylvinylsiloxane methylphenylsiloxane copolymer with both molecular chain terminals blocked with dimethylvinylsiloxy groups, a dimethylpolysiloxane with both molecular chain terminals blocked with trivinylsiloxy groups and so on.

Further, copolymers having the siloxane units described below can be exemplified.

A copolymer having a siloxane unit represented by a formula: R<NUM><NUM>SiO<NUM>/<NUM> (R<NUM> representing an unsubstituted or substituted monovalent hydrocarbon group other than an alkenyl group, the same applying to the following), a siloxane unit represented by a formula: R<NUM><NUM>R<NUM>SiO<NUM>/<NUM> (R<NUM> representing an alkenyl group, the same applying to the following), a siloxane unit represented by a formula: R<NUM><NUM>SiO<NUM>/<NUM>, and a siloxane unit represented by a formula: SiO<NUM>/<NUM>,.

Examples of R<NUM> in the above formulas include: alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group; aryl groups such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; aralkyl groups such as a benzyl group and a phenethyl group; and halogenated alkyl groups such as a chloromethyl group, a <NUM>-chloropropyl group, and a <NUM>,<NUM>,<NUM>-trifluoropropyl group. Examples of R<NUM> in the formulas include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group.

One kind of the polymers or the copolymers can be used independently, or two or more kinds of them can be used in combination.

Further, as the (A) component, an alkenyl group-containing polyorganosiloxane containing a trifunctional siloxane unit having an aryl group (hereinafter, referred to as a polyorganosiloxane AA) can also be used. In this polyorganosiloxane, the number of alkenyl groups in one molecule is not particularly limited, but two or more is preferable. Hereinafter, the polyorganosiloxane AA will be described.

Examples of the alkenyl group bonded to a silicon atom in the polyorganosiloxane AA include the ones having a number of carbon atoms of <NUM> to <NUM>, such as a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group, the ones having a number of carbon atoms more preferably <NUM> to <NUM>. The vinyl group is particularly preferable. Such an alkenyl group may be bonded to a silicon atom at either the terminal or the middle of a molecular chain, and may be bonded to a silicon atom at both of the terminal and the middle of a molecular chain.

Examples of the aryl group contained in the trifunctional siloxane unit include the ones having a number of carbon atoms of <NUM> to <NUM>, such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. The phenyl group is particularly preferable.

The polyorganosiloxane AA has an organic group bonded to a silicon atom, in addition to the alkenyl group and the aryl group. Examples of the organic group other than the alkenyl group and the aryl group include: alkyl groups having a number of carbon atoms of <NUM> to <NUM>, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a heptyl group; and halogenated alkyl groups such as a chloromethyl group, a <NUM>-chloropropyl group, and a <NUM>,<NUM>,<NUM>-trifluoropropyl group. The methyl group is preferable.

In the polyorganosiloxane AA, the ratio of the trifunctional siloxane unit having an aryl group relative to all constituent units is not particularly limited, but a ratio of <NUM> to <NUM> mol% is preferable, and a ratio of <NUM> to <NUM> mol% is more preferable from the viewpoint of the handling workability of a composition before curing and the mechanical strength of a cured product. In particular, as the polyorganosiloxane AA, it is preferable to contain the polyorganosiloxane containing a trifunctional siloxane unit (hereinafter, referred to as a Tph unit) represented by a formula: C<NUM>H<NUM>SiO<NUM>/<NUM> at a ratio of <NUM> to <NUM> mol%. The content ratio of the Tph unit relative to all constituent units is more preferably <NUM> to <NUM> mol%.

Besides, the polyorganosiloxane AA preferably contains a bifunctional siloxane unit in addition to the trifunctional siloxane unit having an aryl group. Further, a part of the bifunctional siloxane unit preferably contains the alkenyl group (for example, the vinyl group).

Further, as the polyorganosiloxane AA, it is preferable to use at least two kinds of polyorganosiloxanes such as a polyorganosiloxane containing a bifunctional siloxane unit (hereinafter, referred to as a Dvi unit) represented by a formula: CH<NUM>(CH<NUM>=CH)SiO<NUM>/<NUM> at a ratio of <NUM> mol% or less relative to all constituent units, and a polyorganosiloxane containing the Dvi unit at a ratio of more than <NUM> mol%. The polyorganosiloxane AA has such two kinds of polyorganosiloxanes and thereby provides an effect of facilitating adjustment of the hardness and elastic modulus of the cured product.

The viscosity (<NUM>) of the polyorganosiloxane AA is preferably <NUM>,<NUM> to <NUM>,<NUM>,<NUM> mPa·s, and is more preferably <NUM>,<NUM> to <NUM>,<NUM>,<NUM> mPa·s. When the viscosity (<NUM>) of the polyorganosiloxane AA falls within the range, the workability of the composition to be obtained is excellent and the physical properties of the cured product of the composition is also excellent.

The polyorganohydrogensiloxane being the (B) component reacts with the (A) component and acts as a cross-linking component. The molecular structure of the (B) component is not particularly limited, and, for example, various kinds of polyorganohydrogensiloxanes in linear, cyclic, branched, three-dimensional network (resinoid) structures can be used.

In the case of using the polyorganosiloxane AA as the (A) component, the polyorganohydrogensiloxane being the (B) component preferably has two or more, preferably three or more hydrogen atoms bonded to silicon atoms, namely, hydrosilyl groups (Si-H groups) in one molecule. When the polyorganohydrogensiloxane being the (B) component is in a linear structure, these Si-H groups may be located only at one of the terminal and the middle of a molecular chain, and may be located at both of them. The polyorganohydrogensiloxane having Si-H groups at both terminals of a molecular chain is preferable used in the point that the viscosity of the composition before curing can be decreased and the hardness of the cured product can be appropriately adjusted. Further, the number of silicon atoms (degree of polymerization) in one molecule of the (B) component is preferably <NUM> to <NUM>,<NUM> and more preferably <NUM> to <NUM>.

When the polyorganosiloxane AA as the (A) component is used, the number of hydrogen atoms in one molecule of the polyorganohydrogensiloxane being the (B) component is preferably <NUM> or more, and more preferably <NUM> or more. The number of silicon atoms (degree of polymerization) in one molecule of the (B) component is preferably <NUM> to <NUM>, and more preferably <NUM> to <NUM>.

Both in the case of using the polyorganosiloxane AA as the (A) component and in the case of using another alkenyl group-containing polyorganosiloxane, it is preferable to use, as the (B) component, a polyorganohydrogensiloxane represented by an average composition formula: R<NUM>pHqSiO(<NUM>-p-q)/<NUM> (in the formula, R<NUM> representing an unsubstituted or substituted monovalent hydrocarbon group having a number of carbon atoms of <NUM> to <NUM> and more preferably <NUM> to <NUM> except an alkenyl group, and p and q being positive numbers satisfying <NUM> ≤ p ≤ <NUM>, <NUM> ≤ q ≤ <NUM>, and <NUM> ≤ p + q ≤ <NUM>, and more preferably <NUM> ≤ p + q ≤ <NUM>).

Examples of the above R<NUM> include: alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, an octyl group, a nonyl group, and a decyl group; aryl groups such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; aralkyl groups such as a benzyl group, a phenylethyl group, and a phenylpropyl group; and groups with a part or all of hydrogen atoms in these hydrocarbon groups substituted by halogen atoms, such as a chloromethyl group, a <NUM>-chloropropyl group, a bromoethyl group, and a <NUM>,<NUM>,<NUM>-trifluoropropyl group. The R<NUM> is preferably the alkyl group or the aryl group, and more preferably the methyl group or the phenyl group.

Concrete example of the (B) component include a methylhydrogenpolysiloxane with both molecular chain terminals blocked with trimethylsiloxy groups, a dimethylsiloxane methylhydrogensiloxane copolymer with both molecular chain terminals blocked with trimethylsiloxy groups, a dimethylsiloxane methylhydrogensiloxane methylphenylsiloxane copolymer with both molecular chain terminals blocked with trimethylsiloxy groups, a dimethylpolysiloxane with both molecular chain terminals blocked with dimethylhydrogensiloxy groups, a dimethylsiloxane methylhydrogensiloxane copolymer with both molecular chain terminals blocked with dimethylhydrogensiloxy groups, a dimethylsiloxane methylphenylsiloxane copolymer with both molecular chain terminals blocked with dimethylhydrogensiloxy groups, a methylphenylpolysiloxane with both molecular chain terminals blocked with dimethylhydrogensiloxy groups, a diphenylpolysiloxane with both molecular chain terminals blocked with dimethylhydrogensiloxy groups and so on.

Further, as the (B) component, copolymers having the siloxane units described below can be exemplified.

A copolymer having a siloxane unit represented by a formula: R<NUM><NUM>SiO<NUM>/<NUM> (R<NUM> being as described above), a siloxane unit represented by a formula: R<NUM><NUM>HSiO<NUM>/<NUM>, and a siloxane unit represented by a formula: SiO<NUM>/<NUM>,.

In particular, in the case of using the polyorganosiloxane AA as the (A) component, it is preferable to contain a polyorganohydrogensiloxane having a TPh unit or a DPh2 unit as the (B) component from the viewpoint of compatibility with the (A) component. Note that the DPh2 unit is a bifunctional siloxane unit represented by a formula: (C<NUM>H<NUM>)<NUM>SiO<NUM>/<NUM>.

The compounding amount of the polyorganohydrogensiloxane being the (B) component is an effective amount for curing the (A) component, and in the case of using an alkenyl group-containing polyorganosiloxane other than the polyorganosiloxane AA as the (A) component, it is compounded so that an amount of the Si-H group contained in the (B) component becomes <NUM> to <NUM> and more preferably <NUM> to <NUM> per alkenyl group (for example, a vinyl group) in the (A) component. When it is less than <NUM>, the curing reaction does not proceed, and it may become difficult to obtain a cured product, whereas when it is more than <NUM>, many unreacted Si-H groups remain in a cured product, and therefore the physical properties of the cured product may change with time.

Further, in the case of using the polyorganosiloxane AA as the (A) component, the compounding amount of the (B) component is such an amount that an amount of the Si-H group contained in the (B) component becomes <NUM> to <NUM> and more preferably <NUM> to <NUM> per alkenyl group (for example, a vinyl group) in the (A) component. When it is less than <NUM>, the curing reaction does not proceed, and it may become difficult to obtain a cured product, whereas when it is more than <NUM>, many unreacted Si-H groups remain in a cured product, and therefore the physical properties of the cured product may change with time.

The platinum-based catalyst being the (C) component is a catalyst that proceeds the addition reaction (hydrosilylation reaction) between the alkenyloxy group in the (A) component and the Si-H group in the (B) component. As the (C) component, for example, a chloroplatinic acid, an alcohol solution of the chloroplatinic acid, a platinum complex having olefines, a vinyl group-containing siloxane, or an acetylene compound as a ligand and so on can be used.

The compounding amount of the (C) component is not particularly limited as along as it is an effective amount as the catalyst for the hydrosilylation reaction, and is <NUM> to <NUM>,<NUM> ppm, more preferably <NUM> to <NUM> ppm, and furthermore preferably <NUM> to <NUM> ppm, when it is converted into a platinum element, relative to the total amount of the (A) component and the (B) component. In the case where the compounding amount is within this range, the addition reaction is accelerated to provide enough curing and economical advantage.

The (D) component is a component that imparts adhesiveness to the polyorganosiloxane composition in the second embodiment of the present invention. As the (D) component, an adhesiveness imparting agent being the above-described first embodiment, namely, the polyorganosiloxane containing one kinds of siloxane unit selected from among the (a) T1ep unit, D1ep unit, and M1ep unit and the (b) D1vi unit, and having an Mw of <NUM> to <NUM> is used.

The compounding amount of the (D) component is <NUM> to <NUM> parts by mass relative to <NUM> parts by mass of the (A) component. If the compounding amount of the (D) component is too much, the (D) component does possibly not contribute to the improvement in adhesiveness. A more preferable compounding amount of the (D) component is <NUM> to <NUM> parts by mass.

In the composition in the second embodiment of the present invention, well-known additives can be compounded as necessary in addition to the above-described (A) component, (B) component, (C) component, and (D) component. For example, a reinforcing filler such as fumed silica, and a non-reinforcing filler such as calcium carbonate, calcium silicate, titanium dioxide, ferric oxide, carbon black, zinc oxide, wavelength adjusting agent and so on may be compounded in a range not impairing the object of the present invention. When the composition is used as a sealant of an LED device, it is preferable to compound the fumed silica, wavelength adjusting agent and so on.

Further, in the case of using the polyorganosiloxane AA as the (A) component, an (E) isocyanurate compound having an alkoxy group can be compounded. As the (E) isocyanurate compound having an alkoxy group, for example, isocyanuric acid derivatives having one or more alkoxysilyl groups as represented by [Chemical Formula <NUM>] to [Chemical Formula <NUM>] can be exemplified. One kind of the isocyanuric acid derivatives can be used independently, or two or more kinds of them can be used in mixture. <CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

These isocyanuric acid derivatives can be manufactured by subjecting <NUM>,<NUM>,<NUM>-triallylisocyanurate and alkyldialkoxysilane to a hydrosilylation reaction in the presence of a platinum catalyst.

The compounding amount of the (E) component is preferably <NUM> to <NUM> parts by mass and more preferably <NUM> to <NUM> parts by mass, relative to <NUM> parts by mass of the (A) component. By compounding the (E) component, the adhesiveness with PPA or the like of the cured product can be further improved.

The adhesive polyorganosiloxane composition in the second embodiment is prepared by uniformly mixing the above-described components, and its curability can be arbitrarily adjusted by addition of a reaction inhibitor. Examples of the inhibitor for the curing reaction include acetylene alcohol such as <NUM>-methyl-<NUM>-butyne-<NUM>-ol and <NUM>-phenyl-<NUM>-butyne-<NUM>-ol, and a maleic acid derivative such as maleic acid diallyl. By using such a reaction inhibitor, the adhesive polyorganosiloxane composition can be used in one liquid.

Further, the adhesive polyorganosiloxane composition can also be stored while separated in two liquids to prevent curing from proceeding, and the two liquids can be mixed together in use for curing. For the two-liquid-mixing type, it is necessary to avoid storage of the polyorganohydrogensiloxane being the (B) component and the platinum-based catalyst being the (C) component in the same wrapper in terms of the risk of a dehydrogenation reaction.

The viscosity of the adhesive polyorganosiloxane composition in the second embodiment thus obtained is preferably in a range of <NUM> to <NUM>,<NUM> Pa·s and particularly preferably in a range of <NUM> to <NUM>,<NUM> Pa·s as a value measured by a rotational viscometer at <NUM>.

The composition in the second embodiment is cured by being heated as necessary. Note that the curing condition is not particularly limited, but the composition may cure in about <NUM> minute to <NUM> hours and more preferably in about <NUM> minutes to <NUM> hours normally at <NUM> to <NUM> and more preferable <NUM> to <NUM>.

The cured product has a sufficient rubber hardness and has excellent adhesiveness to noble metals such as Ag, Au, and heat-resistant plastic such as PPA. Further, the adhesiveness never decreases due to heat generation from the light emitting element, heating in the temperature cycle or the like. Accordingly, the cured product is suitable, for example, as the sealing material for a emitting element in an LED device and a material of a functional lens. The LED device formed with a sealing layer of the cured product of the polyorganosiloxane composition is excellent in reliability because the adhesiveness between the sealing layer and the base material such as PPA is excellent and peeling hardly occurs at the boundary face.

Hereinafter, the present invention will be concretely described using examples but is not limited to the examples.

In the following description, an M unit, an Mvi unit, an MH unit, a D unit, a DVi unit, a DH unit, a DPh2 unit, a T unit, a TPh unit, and a Q unit represent siloxane units represented by the following formulas respectively. Further, the methyl group is referred to as Me, the phenyl group is referred to as Ph, and the vinyl group is referred to as Vi, respectively in some cases.

Further, the viscosity is a value at <NUM> unless otherwise stated.

First, adhesiveness imparting agents (D1) to (D6) were prepared as follows.

In a <NUM>-L reaction container, <NUM> (<NUM> mol) of γ-glycidoxypropyltrimethoxysilane, <NUM> (<NUM> mol) of dimethyldimethoxysilane, <NUM> (<NUM> mol) of methyltrimethoxysilane, <NUM> (<NUM> mol) of methylvinyldimethoxysilane, and <NUM> of toluene were charged, and then <NUM> of 6N sodium hydroxide (NaOH) solution, and <NUM> of ion-exchange water (the ion-exchange water to be added at this stage is referred to as ion-exchange water (<NUM>)) were put thereinto and stirred.

When a mixture in the reaction container was heated until the liquid temperature became <NUM>, a partial hydrolysis reaction of methoxy groups of the above-described four kinds of silane compounds (y-glycidoxypropyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, and methylvinyldimethoxysilane) was started to generate heat. Even after the heating was stopped, the heat generation continued, and the reaction mixture became transparent and increased in temperature up to <NUM>. The stirring was continued, and at the point when the temperature started to decrease, <NUM> of ion-exchange water (the ion-exchange water to be added at this stage is referred to as ion-exchange water (<NUM>)) was added, and the partial hydrolysis reaction was further continued. After the addition of the ion-exchange water (<NUM>), the reaction mixture immediately became transparent and uniform and started heat generation, and increased in temperature up to <NUM>. Thereafter, the inside of the reaction container was heated to a reflux temperature (<NUM>) using an oil bath. Then, the heating reflux state was continued for <NUM> hour, and the reaction mixture was then cooled down to room temperature.

Subsequently, <NUM> of toluene was added to the obtained reaction mixture, and they were heated again up to the reflux temperature, and methanol being a reaction product was distilled off together with toluene. When the distillation of methanol was completed and the reaction mixture was brought into the reflux state at a boiling point of toluene, the reaction mixture was cooled and returned to room temperature.

Into the reaction mixture thus obtained, <NUM> of glacial acetic acid was added and they were stirred for <NUM> hour to neutralize the previously added sodium hydroxide. Thereafter, while the reaction mixture was being heated to the reflux temperature again using the oil bath, nitrogen was flowed into the reaction container to remove a solvent under a reduced pressure of <NUM>/<NUM> mmHg, and concentration was performed until distillate was no longer produced. Then, the liquid in the reaction container was cooled, and then subjected to filtration using Celite (manufactured by World Minerals Inc. ), whereby the adhesiveness imparting agent (D1) was obtained.

In a reaction container, γ-glycidoxypropyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, methylvinyldimethoxysilane, and toluene in the same amounts as those in Synthesis Example <NUM> were charged. Then, the same operation as that in Synthesis Example <NUM> except that the ion-exchange water (<NUM>) and the ion-exchange water (<NUM>) in masses listed in Table <NUM> were added to change the degrees of the partial hydrolysis reaction and the condensation reaction was performed, whereby the adhesiveness imparting agents (D2) to (D3) were obtained.

In a reaction container, <NUM> (<NUM> mol) of γ-glycidoxypropyltrimethoxysilane, <NUM> (<NUM> mol) of dimethyldimethoxysilane, <NUM> (<NUM> mol) of methylvinyldimethoxysilane, and <NUM> of toluene were charged, and the same operation as that in Synthesis Example <NUM> was performed, whereby the adhesiveness imparting agent (D4) was obtained. Note that also in the Synthesis Example <NUM>, the ion-exchange water (<NUM>) and the ion-exchange water (<NUM>) in masses listed in Table <NUM> were added as in Synthesis Examples <NUM> to <NUM> to change the degrees of the partial hydrolysis reaction and the condensation reaction from those in Synthesis Example <NUM>.

In a reaction container, γ-glycidoxypropyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, methylvinyldimethoxysilane, and toluene in the same amounts as those in Synthesis Example <NUM> were charged. Then, the same operation as that in Synthesis Example <NUM> except that the ion-exchange water (<NUM>) and the ion-exchange water (<NUM>) in masses listed in Table <NUM> were added to change the degrees of the partial hydrolysis reaction and the condensation reaction was performed, whereby the adhesiveness imparting agent (D5) was obtained.

In a <NUM>-L reaction container, <NUM> (<NUM> mol) of γ-glycidoxypropyltrimethoxysilane, <NUM> (<NUM> mol) of methyltrimethoxysilane, <NUM> (<NUM> mol) of diphenyldimethoxysilane, <NUM> (<NUM> mol) of dimethyldimethoxysilane, <NUM> (<NUM> mol) of methylvinyldimethoxysilane, and <NUM> of toluene were charged. Then, the same operation as that in Synthesis Example <NUM> was performed, whereby the adhesiveness imparting agent (D6) was obtained.

Next, the copolymerization composition ratios of the adhesiveness imparting agents (D1) to (D6) obtained in Synthesis Examples <NUM> to <NUM> respectively were measured using deuterochloroform as a solvent and using <NUM>H-NMR (manufactured by BRUKER Corporation, apparatus name; ARX-<NUM>).

As a result of measurement, it was found that each of the adhesiveness imparting agents (D1) to (D3) and (D5) had a trifunctional siloxane unit (hereinafter, referred to as a Tep unit) represented by a formula: RSiO<NUM>/<NUM>
(in the formula, R representing a γ-glycidoxypropyl group represented by the following chemical formula),
<CHM>
a T unit, a D unit, a Dvi unit, and a methoxy group (hereinafter, referred to as OMe), and their molar abundance ratios of the units and the methoxy group (t1:t2:d1:d2:e) were as those listed in Table <NUM>.

Further, the adhesiveness imparting agent (D4) did not contain the T unit but had the Tep unit, the D unit, the Dvi unit, and the methoxy group (OMe), and t1, d1, d2, and e in the molar abundance ratio of the units and the methoxy group (t1:t2:d1:d2:e) were as those listed in Table <NUM>.

Further, the adhesiveness imparting agent (D6) had the Tep unit, the T unit, the D unit, the Dvi unit, the DPh unit, and the methoxy group (OMe), and the molar abundance ratio of the units and the methoxy group (t1:t2:d1:d1:d2:d3:e) was <NUM>:<NUM>:<NUM>:<NUM>:<NUM>:<NUM> as listed in Table <NUM>.

Furthermore, the weight-average molecular weight (Mw), the number average molecular weight (Mn), the degree of dispersion (Mw/Mn), the nonvolatile content (mass%), the viscosity (mPa·s), the epoxy equivalent (g/eq), the epoxy group content (mmol/g), the yield amount, and the yield rate of each of the obtained adhesiveness imparting agents (D1) to (D6) were measured. These measured values are listed in Table <NUM> together with the amounts of the starting materials used.

Mw and Mn are values measured using a gel permeation chromatography (GPC) apparatus (manufactured by Tosoh Corporation, apparatus name; HLC-<NUM> GPC) using THF (tetrahydrofuran) as a solvent, and converted into polystyrene. The degree of dispersion is a numerical value representing the molecular weight distribution and is found by weight-average molecular weight (Mw)/number average molecular weight (Mn). The degree of dispersion indicates that as it becomes closer to <NUM>, the molecular weight distribution is narrower. Further, nonvolatile content (mass%) is a value measured under the heating condition of <NUM> × <NUM> hour, and the viscosity is a measured value at <NUM>. Further, the yield rate is calculated by the following calculation formula. <MAT> where the theoretical hydrolysate amount (g) is the total of the hydrolysate amounts of silanes being the starting materials (number of moles × hydrolysate molecular weight).

A polyorganosiloxane composition was prepared by mixing:.

The (A1), (A2) used in Example <NUM>, (A3) a linear dimethylpolysiloxane with both molecular chain terminals blocked with dimethylvinylsiloxy groups (viscosity of <NUM>,<NUM> mPa·s), a (A4) <NUM>:<NUM> (nonvolatile content) mixture of a linear dimethylpolysiloxane with both molecular chain terminals blocked with dimethylvinylsiloxy groups (viscosity of <NUM>,<NUM> mPa·s) and a branched methylpolysiloxane represented by an average unit formula: M<NUM>MviQ<NUM> (Mn = <NUM>, Mw/Mn = <NUM>), the (B1) used in Example <NUM>, (B2) a methylhydrogenpolysiloxane having a hydrogen atom bonded to silicon at a middle of a molecular chain represented by a unit formula: MDH<NUM>D<NUM>M, the (C) platinum complex solution having tetramethyltetravinylcyclotetrasiloxane as a ligand (Pt content of <NUM> mass%), and a reaction inhibitor, were compounded at ratios listed in Table <NUM>. Further, as the adhesiveness imparting agent, the adhesiveness imparting agents (D2) to (D5) obtained in Synthesis Examples <NUM> to <NUM> or γ-glycidoxypropyltrimethoxysilane (epoxy group content of <NUM> mmol/g) were compounded at ratios listed in Table <NUM> to prepare polyorganosiloxane compositions.

The viscosities of the polyorganosiloxane compositions thus obtained in Examples <NUM> to <NUM> and Comparative Example <NUM> to <NUM> were measured using a rotational viscometer at <NUM>. Further, as indicated below, the obtained polyorganosiloxane compositions were subjected to thermogravimetric analysis (TGA). Further, a package test (<NUM>) was performed on the polyorganosiloxane compositions to investigate adhesiveness under temperature rise. The results are listed in a low column in Table <NUM>.

Samples of the polyorganosiloxane compositions were left at <NUM> for <NUM> hour and their weight decrease ratios were measured by a TGA apparatus (manufactured by Seiko Instruments, Inc. apparatus name; TG/DTA6200).

Samples of the polyorganosiloxane compositions were filled in a reflector made of PPA of a <NUM>-type LED package (SAYO SEIKI SEISAKUSYO CO. ), then heated at <NUM> for <NUM> hour, and then heated at <NUM> for <NUM> hours to be cured. Subsequently, aging was performed for <NUM> hours at <NUM> in an atmosphere of <NUM> %RH, and then heated with a profile illustrated in <FIG> to be increased in temperature. More specifically, the samples were increased in temperature from <NUM> at a rate of <NUM>/sec for about <NUM> seconds and kept at <NUM> for <NUM> minute, and then further increased in temperature at a rate of <NUM>/sec for <NUM> seconds and kept at <NUM> for <NUM> seconds. Then, the temperature at which the cured compositions peeled off from the reflector made of PPA were found.

From Table <NUM> and Table <NUM>, the following is found.

The polyorganosiloxane compositions in Examples <NUM> to <NUM> obtained by compounding the adhesiveness imparting agents (D1) to (D4) each containing (a) a Tep unit having an epoxy group and (b) a Dvi unit being the bifunctional siloxane unit having an alkenyl group, and having an Mw in a range of <NUM> to <NUM>, in an addition reaction type polyorganosiloxane composition, are substantially low in weight decrease ratio by TGA as compared with the polyorganosiloxane compositions in Comparative Examples <NUM> to <NUM> in which γ-glycidoxypropyltrimethoxysilane or the adhesiveness imparting agent (D-<NUM>) having an Mw of <NUM> or less is compounded as the adhesiveness imparting agent, showing that volatilization of the adhesiveness imparting agent due to heating hardly occurs.

It is also found that peeling of the sealing layers composed of the polyorganosiloxane compositions in Comparative Examples <NUM> to <NUM> occurs at the boundary face with the base material (reflector) made of PPA in the temperature rise process after curing, whereas there is no peeling observed in the sealing layers composed of the polyorganosiloxane compositions in Examples <NUM> to <NUM>, showing that excellent adhesiveness to PPA is maintained.

Next, other examples of using an alkenyl group-containing polyorganosiloxane containing a trifunctional siloxane unit having an aryl group as a base polymer will be described.

In a mixture of (Aa1) <NUM> (<NUM> mol) of dimethyldichlorosilane, (Aa2) <NUM> (<NUM> mol) of diphenyldichlorosilane, and (Aa3) <NUM> (<NUM> mol) of phenyltrichlorosilane, a methanol solution composed of <NUM> of water and <NUM> of methanol was dripped to perform cohydrolysis. After finish of the dripping, heating was performed for <NUM> minutes at a reflux temperature of <NUM> to <NUM> to complete the cohydrolysis reaction. Thereafter, the reaction mixture was cooled, and <NUM> of methanol was added thereto, and they were stirred for <NUM> minutes and then left standing still for <NUM> minutes for liquid separation. The reaction mixture was separated such that a mixed solution of hydrochloric acid and methanol became an upper layer and a reaction product became a lower layer.

Subsequently, <NUM> of methanol was added to the reaction product being the lower layer, and they were subjected to heating and distillation, whereby the hydrochloric acid content in the reaction product was distilled off together with methanol. Thus, a silicone resin AA having a methoxy group represented by an average unit formula:
(Me<NUM>SiO<NUM>/<NUM>)<NUM>(Me<NUM>SiO<NUM>/<NUM>OMe)<NUM>(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>OMe)<NUM>(PhSiO<NUM>/<NUM>)<NUM>{PhSiO<NUM>/<NUM>(OMe)<NUM>}<NUM>(PhSiO<NUM>/<NUM>OMe)<NUM> was obtained.

In the average unit formula representing the silicone resin AA, an (aa1) unit:
(Me<NUM>SiO<NUM>/<NUM>)<NUM>(Me<NUM>SiO<NUM>/<NUM>OMe)<NUM> was produced from the starting material (Aa1), an (aa2) unit:
(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>OMe)<NUM> was produced from the starting material (Aa2), and an (aa3) unit:
(PhSiO<NUM>/<NUM>)<NUM>{PhSiO<NUM>/<NUM>(OMe)<NUM>}<NUM>(PhSiO<NUM>/<NUM>OMe)<NUM> was produced from the starting material (Aa3). The molar ratio of the units is (aa1):(aa2):(aa3) = <NUM>:<NUM>:<NUM>≈<NUM>:<NUM>:<NUM>.

Subsequently, <NUM> of methanol was added to the reaction product being the lower layer, and they were subjected to heating and distillation, whereby the hydrochloric acid content in the reaction product was distilled off together with methanol. Thus, a silicone resin BB having a methoxy group represented by an average unit formula:
(Me<NUM>SiO<NUM>/<NUM>)<NUM>(Me<NUM>SiO<NUM>/<NUM>OMe)<NUM>(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>OMe)<NUM>(PhSiO<NUM>/<NUM>)<NUM>{PhSiO<NUM>/<NUM>(OMe)<NUM>}<NUM>(PhSiO<NUM>/<NUM>OMe)<NUM> was obtained.

In the average unit formula representing the silicone resin BB, an (aa1) unit:
(Me<NUM>SiO<NUM>/<NUM>)<NUM>(Me<NUM>SiO<NUM>/<NUM>OMe)<NUM> was produced from the starting material (Aa1), an (aa2) unit:
(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>OMe)<NUM> was produced from the starting material (Aa2), and an (aa3) unit:
(PhSiO<NUM>/<NUM>)<NUM>{PhSiO<NUM>/<NUM>(OMe)<NUM>}<NUM>(PhSiO<NUM>/<NUM>OMe)<NUM> was produced from the starting material (Aa3). The molar ratio of the units is (aa1):(aa2):(aa3) = <NUM>:<NUM>:<NUM>=<NUM>:<NUM>:<NUM>.

In a <NUM>-L reaction container, <NUM> (<NUM> mol) of octamethylcyclotetrasiloxane, <NUM> (<NUM> mol) of divinyltetramethyldisiloxane, and <NUM> (<NUM> mol) of tetramethyltetravinylcyclotetrasiloxane were charged, <NUM> of potassium hydroxide corresponding to <NUM> ppm of the total mass (<NUM>) was added thereto, and they were stirred. Then, while the stirring was performed, a mixture was heated up to <NUM> and subjected to ring-opening polymerization for <NUM> hours.

After the finish of the ring-opening polymerization, the mixture was sufficiently cooled, and then <NUM> of trimethylsilylchloride was added thereto and sufficiently stirred to deactivate the potassium hydroxide. Thus, an intermediate product CC was obtained. Then, xylene was added thereto to dilute the intermediate product CC so that its concentration of a resin content became <NUM>% or less, then a solution made by dissolving <NUM> of NaCl into <NUM> of water (hereinafter, referred to as a water/NaCl solution) was added to a diluted solution, and they were heated, whereby deoxidation was performed. After a mixed solution of a xylene solution of the intermediate product CC and the water/NaCl solution reached <NUM> or higher, the stirring was stopped for liquid separation. The xylene solution of the intermediate product CC being an upper layer was fractionated, then a <NUM>/<NUM>/<NUM> solution of water/methanol/NaCl was added to the fractionated solution, and heating and washing were performed. By this operation, a volatile low-molecular siloxane having a number of D units contained in the xylene solution of the intermediate product CC of <NUM> or less was extracted and removed.

After the mixed solution of the xylene solution of the intermediate product CC and the water/methanol/NaCl solution reached <NUM> or higher, the stirring was stopped for liquid separation, and the xylene solution of the intermediate product CC being the upper layer was fractionated. Since the fractionated xylene solution of the intermediate product CC contained small amounts of methanol and water together with the volatile low-molecular siloxane having a number of D units of <NUM> or less, a <NUM>/<NUM> solution of water/NaCl was further added, and heating and washing were performed. Then, after the mixed solution reached <NUM> or higher, the stirring was stopped for liquid separation. The xylene solution of the intermediate product CC being the upper layer was fractionated, and then the fractionated solution was subjected to heating reflux, whereby dehydration was performed. Subsequently, the solution was subjected to cooling, then filtration, and removal of solvent by heating under reduced pressure. Thus, the polymethylsiloxane having vinyl groups at a terminal and a side chain being the intermediate product CC was obtained.

In the intermediate product CC thus obtained, the numbers of moles of the units calculated from the charged amounts result in that the D unit is <NUM> ((<NUM>/<NUM>) × <NUM>), the Mvi unit is <NUM> ((<NUM>/<NUM>) × <NUM>), and the DVi unit is <NUM> ((<NUM>/<NUM>) × <NUM>), and the molar ratio is the D unit: the Mvi unit: the DVi unit = <NUM>:<NUM>:<NUM>.

Accordingly, the obtained intermediate product CC is found to be the polymethylsiloxane having vinyl groups at terminals and a side chain represented by an average unit formula: MviD<NUM>DVi<NUM>Mvi.

Synthesis Example <NUM> [synthesis of a silicone resin A-<NUM>].

<NUM> of xylene was added to <NUM> of the intermediate product AA (silicone resin having a methoxy group) for dilution, a dilution was subjected to hydrolysis by adding <NUM> of <NUM> mass% (referred to as <NUM>%, the same applying to the following) cesium hydroxide solution and <NUM> of water thereto and heating. In infrared absorption spectrum measurement, the reaction was continued until characteristic absorption coming to the methoxy group at a wave number of <NUM>-<NUM> disappeared.

Thus, a cerium hydroxide-containing xylene solution of a silicone resin polymer having no methoxy group represented by an average unit formula: (Me<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(PhSiO<NUM>/<NUM>)<NUM> was obtained.

To <NUM> of the resin content of a reaction product obtained in the first step, <NUM> of polymethylsiloxane having vinyl groups at both terminals and a side chain (Vi amount of <NUM> mmol/g) being the intermediate product CC and <NUM> of cyclic polymethylvinylsiloxane (MeViSiO<NUM>/<NUM>)<NUM> (Vi amount of <NUM> mmol/g) were added, and they were reacted at a xylene reflux temperature for <NUM> hours for graft polymerization and equilibrium. After cooling, <NUM> of trimethylchlorosilane was added for neutralization, an operation (water-washing operation) of washing the xylene solution with water and removing a water layer by a liquid separation was performed. After the water layer was neutralized by repeating the water-washing operation, water remaining in a xylene layer was removed by subjecting the water and xylene to azeotropy. Thus, by filtrating the xylene layer after completion of dehydration and then distilling off xylene under reduced pressure, a silicone resin A-<NUM> was obtained.

The silicone resin A-<NUM> was obtained by reacting an organosiloxane G represented by an average unit formula: (Me<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(PhSiO<NUM>/<NUM>)<NUM>, a polymethylsiloxane H having vinyl groups at both terminals and a side chain represented by a formula: MviD<NUM>Dvi<NUM>Mvi, and an organosiloxane I represented by a formula:
(MeViSiO<NUM>/<NUM>)<NUM> at a mass ratio (%) of G:H:I = <NUM>:<NUM>:<NUM> in terms of charge amount.

In the second step, the polymethylsiloxane having vinyl groups at both terminals and a side chain and the cyclic methylvinylsiloxane were split and graft-polymerized with the reaction product obtained in the first step, whereby the silicone resin A-<NUM> was obtained.

The copolymerization composition ratio of the obtained silicone resin A-<NUM> was measured by using deuterochloroform as a solvent and using <NUM>H-NMR (manufactured by BRUKER Corporation, apparatus name; ARX-<NUM>). As a result of the measurement, it was found that the silicone resin A-<NUM> was represented by an average composition formula: TPh<NUM>DPh2<NUM>D<NUM>DVi<NUM>MVi<NUM>.

The silicone resin A-<NUM> had a viscosity of <NUM> Pa·s, a nonvolatile content measured after heated at <NUM> for <NUM> hour of <NUM> mass% (hereinafter, referred to as %, and meaning a weight loss on heating of <NUM>%), an Mw of <NUM>, and a degree of dispersion (Mw/Mn) of <NUM>. Note that the number of vinyl groups per molecule in the silicone resin A-<NUM> is <NUM> on average from the value of Mw.

<NUM> of xylene was added to <NUM> of the intermediate product AA (silicone resin having a methoxy group) for dilution, and a dilution was subjected to hydrolysis by adding <NUM> of <NUM>% cesium hydroxide solution and <NUM> of water thereto and heating. In infrared absorption spectrum measurement, the reaction was continued until characteristic absorption coming to the methoxy group at a wave number of <NUM>-<NUM> disappeared.

The silicone resin A-<NUM> was obtained by reacting an organosiloxane G represented by an average unit formula: (Me<NUM>SiO<NUM>/<NUM>)<NUM>(Ph<NUM>SiO<NUM>/<NUM>)<NUM>(PhSiO<NUM>/<NUM>)<NUM>, a polymethylsiloxane H having vinyl groups at both terminals and a side chain represented by a formula: MviD<NUM>DVi<NUM>Mvi, and an organosiloxane I represented by a formula:
(MeViSiO<NUM>/<NUM>)<NUM> at a mass ratio (%) of G:H:I = <NUM>:<NUM>:<NUM> in terms of charge amount.

In the second step, the polymethylsiloxane being the silicone resin CC having vinyl groups at both terminals and a side chain and the cyclic methylvinylsiloxane were split and graft-polymerized with the reaction product obtained in the first step, whereby the silicone resin A-<NUM> was obtained.

As a result of the measurement of the copolymerization composition ratio of the obtained silicone resin A-<NUM> as in Synthesis Example <NUM>, it was found that the silicone resin A-<NUM> was represented by an average composition formula: TPh<NUM>DPh2 <NUM>D<NUM>DVi<NUM>MVi<NUM>.

The silicone resin A-<NUM> had a viscosity of <NUM> Pa·s, a nonvolatile content measured after heated at <NUM> for <NUM> hour of <NUM> %, an Mw of <NUM>, and a degree of dispersion (Mw/Mn) of <NUM>. Note that the number of vinyl groups per molecule in the silicone resin A-<NUM> is <NUM> on average from the Mw.

<NUM> of xylene was added to <NUM> of the intermediate product BB for dilution, and a dilution was subjected to hydrolysis by adding <NUM> of <NUM>% cesium hydroxide solution and <NUM> of water thereto and heating. In infrared absorption spectrum measurement, the reaction was continued until characteristic absorption coming to the methoxy group at a wave number of <NUM>-<NUM> disappeared.

As a result of the measurement of the copolymerization composition ratio of the obtained silicone resin A-<NUM> as in Synthesis Example <NUM>, it was found that the silicone resin A-<NUM> was represented by an average composition formula: TPh<NUM>DPh2<NUM>D<NUM>DVi<NUM>MVi<NUM>.

The silicone resin A-<NUM> was a solid at normal temperature and had a nonvolatile content measured after heated at <NUM> for <NUM> hour of <NUM> %, an Mw of <NUM>, and a degree of dispersion (Mw/Mn) of <NUM>. Note that the number of vinyl groups per molecule in the silicone resin A-<NUM> is <NUM> on average from the Mw.

<NUM> of xylene was added to <NUM> of the intermediate product BB for dilution, and a dilution was subjected to hydrolysis by adding <NUM> of cesium hydroxide solution with a concentration of <NUM>% and <NUM> of water thereto and heating. In infrared absorption spectrum measurement, the reaction was continued until characteristic absorption coming to the methoxy group at a wave number of <NUM>-<NUM> disappeared.

In the second step, the polymethylsiloxane having vinyl groups at both terminals and a side chain being the intermediate product CC and the cyclic methylvinylsiloxane were split and graft-polymerized with the reaction product obtained in the first step, whereby the silicone resin A-<NUM> was obtained.

<NUM> (<NUM> mol) of tetramethyldisiloxane, <NUM> of concentrated hydrochloric acid, <NUM> of ion-exchange water, and <NUM> of ethanol were charged into a reaction container and cooled to <NUM> or lower while being stirred. After completion of the cooling, <NUM> (<NUM> mol) of phenyltrimethoxysilane was dripped at a rate of <NUM>/hour. The cooling was continued to prevent the temperature of the reaction mixture from exceeding <NUM> since heat generation was started with hydrolysis.

After finish of the dripping of phenyltrimethoxysilane, the hydrolysis was continued for <NUM> hours, and then <NUM> of xylene was added thereto to dilute. A dilution was stirred for <NUM> hour after the dilution, and then left standing still for liquid separation. Its upper layer was a xylene solution of the polyorganohydrogensiloxane. <NUM> of ion-exchange water was added to a fractionated xylene solution, a mixture was subjected to heating and water-washing, and then left standing still again for liquid separation.

<NUM> of methanol and <NUM> of ion-exchange water were added to the upper layer, and a mixture was subjected again to heating and water-washing and then left standing still for liquid separation. Next, the liquid at the upper layer was subjected to heating reflux to remove remaining ion-exchange water and methanol, and then filtration and removal of solvent and concentration under reduced pressure. Finally, by heating the liquid up to <NUM> while introducing nitrogen, and removing the solvent and a volatile fraction while adjusting the degree of pressure reduction into a range of <NUM> to <NUM> mmH using a vacuum pump, <NUM> of polyorganohydrogensiloxane B2 was obtained.

From the amounts of charged components, the effective hydrogen amount, and measurement result of gas chromatography, the obtained polyorganohydrogensiloxane B3 was found to be polyphenylhydrogensiloxane having a branch structure represented by a formula: MH<NUM>TPh<NUM>.

The Mw of the polyorganohydrogensiloxane B3 was <NUM>, and the actual measured hydrogen content was <NUM> % relative to the theoretical hydrogen content of <NUM>%.

<NUM> of <NUM>,<NUM>,<NUM>-triallylisocyanurate (manufactured by Nippon Kasei Chemical Co. , brand name; TAIC) and <NUM> of methyldimethoxysilane were subjected to a hydrosilylation reaction for <NUM> hours in the presence of a catalytic amount of a Pt catalyst. Thus, a mixture of an isocyanuric acid derivative having one methyldimethoxysilyl group and two vinyl groups represented by [Chemical Formula <NUM>] and an isocyanuric acid derivative having two methyldimethoxysilyl groups and one vinyl group represented by [Chemical Formula <NUM>] was obtained. <CHM>
<CHM>
<CHM>.

In a mixture of <NUM> parts of the silicone resin A-<NUM> obtained in Synthesis Example <NUM> (the polyorganosiloxane represented by an average composition formula: TPh<NUM>DPh2<NUM>D<NUM>DVi<NUM>MVi<NUM>) and <NUM> parts of the silicone resin A-<NUM> obtained in Synthesis Example <NUM> (the polyorganosiloxane represented by an average composition formula: TPh<NUM>DPh2<NUM>D<NUM>DVi<NUM>), <NUM> parts of the polyorganohydrogensiloxane B3 obtained in Synthesis Example <NUM>, represented by a unit formula: MH<NUM>Tph<NUM> (the mol (equivalent weight) ratio of the SiH groups in the (B) component relative to the vinyl groups in the (A) component (H/Vi) = <NUM>), (C) <NUM> parts of a platinum complex solution having tetramethyltetravinylcyclotetrasiloxane as a ligand (Pt content of <NUM> %), and <NUM> parts of the adhesiveness imparting agent D1 obtained in Synthesis Example <NUM> represented by a unit formula: Tep<NUM>T<NUM>D<NUM>Dvi<NUM>(OMe)<NUM> were added and kneaded, whereby a polyorganosiloxane composition was obtained.

By compounding the components listed in Table <NUM> and Table <NUM> at ratios listed in the same tables, polyorganosiloxane compositions were obtained as in Example <NUM>.

Note that the H-Vi ratio in Table <NUM> and Table <NUM> indicates the molar ratio between hydrogen atoms bonded to silicon atoms in the (B) component and vinyl groups bonded to silicon atoms in the (A) component.

By compounding the components listed in Table <NUM> at ratios listed in the same table, polyorganosiloxane compositions were obtained as in Example <NUM>.

Note that the SiH group-containing adhesiveness imparting agent in Table <NUM> is a <NUM>:<NUM> addition reaction product of a SiH group-containing siloxane oligomer represented by
<CHM>
and γ-methacryloxypropyltrimethoxysilane. Further, as the γ-glycidoxypropyltrimethoxysilane, TSL8350 (brand name of Momentive) was used. An H/Vi ratio in Table <NUM> indicates the molar ratio between hydrogen atoms bonded to silicon atoms in the (B) component and vinyl groups bonded to silicon atoms in the (A) component.

The viscosities and refractive indexes of the polyorganosiloxane compositions thus obtained in Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM> were measured as follows. Further, after the polyorganosiloxane compositions obtained in Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM> were heated at <NUM>°Cfor <NUM> hours and thereby cured, physical properties (hardness, tensile strength, elongation, and transmittance) of cured products were measured in conformity to JIS K <NUM> "Testing methods for uncured and cured silicones rubber" and so on. In addition, a package test (<NUM>) was performed as follows to investigate adhesiveness to the base material made of the PPA resin. The results of the measurement and test are listed in low columns in Tables <NUM> to <NUM>.

The viscosity of the polyorganosiloxane composition before curing was measured using a rotational viscometer at <NUM>±<NUM>.

Regarding the polyorganosiloxane composition before curing, the refractive index of a sodium D line (wavelength of <NUM>) was measured using a multi-wavelength Abbe refractometer (manufactured by Atago Co. , apparatus name; DR-M2/<NUM>). The measurement was performed at <NUM>.

After a <NUM>-type LED package was dried at <NUM> for <NUM> hours, the sample of the polyorganosiloxane composition was filled in a base material made of a PPA resin (Kuraray Co. , Ltd, brand name; Genestar) using a syringe. Then, the sample was heated at <NUM> for <NUM> hours and then heated at <NUM> for <NUM> hours and thereby cured. The presence or absence of peeling of the cured product from the PPA resin was investigated using a microscope (<NUM> to <NUM> magnifications). The number of samples (n) was <NUM>, and the number of samples where peeling was observed was counted.

Further, for the polyorganosiloxane compositions obtained in Examples <NUM> to <NUM>, the packaged test (<NUM>) was performed, and then the test described below was performed to investigate peeling after MSL3 reflow.

Using an LED package in which the sample was filled and cured, used for the peeling test from the PPA, the MSL3 test in conformity to IPC/JEDEC J-STD-020D. <NUM> was performed. In this test, the LED package in which the sample had been filled and cured was dried at <NUM> for <NUM> hours, and then left as it was for <NUM> hours in a chamber at <NUM>/<NUM>%RH under a condition of Level <NUM> and made to absorb moisture. After the moisture absorption, the LED package was left as it was at room temperature for <NUM> minutes, and put into a reflow oven at a maximum of <NUM> (about <NUM> minutes for one cycle). After cooling at room temperature for <NUM> minutes, the LED package was put again into the reflow oven, and this cycle was repeated three times in total. Then, the LED package was cooled to room temperature, and the presence or absence of peeling of the cured product from the PPA resin was investigated using a microscope (<NUM> to <NUM> magnifications). Then, the number of samples where peeling was observed in ten samples was counted.

From Tables <NUM> to <NUM>, the following is found. The polyorganosiloxane compositions in Examples <NUM> to <NUM> each obtained by compounding the adhesiveness imparting agent D1 or D6 which contains the Tep unit having an epoxy group and the Dvi unit having a vinyl group and has an Mw in a range of <NUM> to <NUM>, in an addition reaction type polyorganosiloxane composition including a polyorganosiloxane containing a trifunctional siloxane unit having a phenyl group (TPh unit) and a vinyl group, as a base polymer, are excellent in adhesiveness to PPA as compared with the polyorganosiloxane composition in Comparative Example <NUM> in which the adhesiveness imparting agent is not compounded, and the polyorganosiloxane compositions in Comparative Examples <NUM> to <NUM> in which γ-glycidoxypropyltrimethoxysilane or the like is compounded as the adhesiveness imparting agent. Specifically, the sealing layers composed of the cured products of the polyorganosiloxane compositions in Comparative Examples <NUM> to <NUM> have peeling occurred on the boundary face with the base material made of PPA, whereas the sealing layers composed of the cured products of the polyorganosiloxane compositions in Examples <NUM> to <NUM> have no peeling observed thereon and therefore exhibit excellent adhesiveness to PPA.

In particular, the polyorganosiloxane compositions obtained in Examples <NUM> to <NUM>, in which the silicone resins A-<NUM> to A-<NUM> high in content ratio of the TPh unit are used as the (A) component, exhibit high reliability also for the peeling test after the MSL3 reflow.

Claim 1:
An adhesiveness imparting agent, comprising a polyorganosiloxane,
the polyorganosiloxane containing:
(a) a trifunctional siloxane unit having an epoxy group and represented by a formula: R<NUM>SiO<NUM>/<NUM>, where R<NUM> represents an epoxyalkyl group or a glycidoxyalkyl group;
(b) a bifunctional siloxane unit having an alkenyl group represented by a formula: R<NUM><NUM>SiO<NUM>/<NUM>, where R<NUM> represents a monovalent hydrocarbon group selected from a group consisting of an alkenyl group and an alkyl group, and at least one R<NUM> is an alkenyl group;
a trifunctional siloxane unit represented by a formula R<NUM>SiO<NUM>/<NUM>, where R<NUM> represents an alkyl group; and
a bifunctional siloxane unit represented by a formula R<NUM><NUM>SiO<NUM>/<NUM>, where R<NUM> represents an alkyl group,
the polyorganosiloxane having a weight-average molecular weight of <NUM> to <NUM>, this molecular weight being measured using a gel permeation chromatography (GPC) apparatus as described in the description.