Comodified organopolysiloxanes and curable organopolysiloxane compositions containing the same

Abstract

[Problem] To provide: an organopolysiloxane compound serving as a starting material for an organopolysiloxane adhesive that has sufficient adhesion as required at a provisional fixing or other step, and is easily peelable from a substrate at a subsequent step; an organopolysiloxane adhesive composition including the same; and a method for using the same. [Solution] A chain co-modified organopolysiloxane containing a silicon-atom-bonded functional group (RA) that contains a specific (meth)acryl group, and a silicon-atom-bonded functional group (RVi) (excluding the functional group that is RA) that contains at least one aliphatic unsaturated carbon-carbon bond; a curable organopolysiloxane composition including the same, said composition further including a crosslinking agent, a hydrosilylation reaction catalyst, and a photo-radical polymerization initiator, and being both heat-curable and photo-curable; and uses of these.

Description

[Technical Field]

[0001] The present invention relates to a chain-like comodified organopolysiloxane characterized by having both a (meth)acrylic functional group and other aliphatic unsaturated carbon-carbon bond-containing groups (such as alkenyl groups) within the molecule, and possessing both heat-curable and photocurable properties; a curable organopolysiloxane composition containing the same; an organopolysiloxane adhesive composition; and a method for using an organopolysiloxane adhesive composition characterized by reducing the adhesive strength of the adhesive to the substrate before and after a photocuring reaction by performing a photocuring reaction after a heat-curing reaction. In this invention, the adhesive includes so-called pressure-sensitive adhesives (=PSA). [Background technology]

[0002] Organopolysiloxane adhesive compositions offer superior electrical insulation, heat resistance, cold resistance, adhesion to various substrates, and, when necessary, transparency, compared to acrylic and rubber-based pressure-sensitive adhesive compositions. Therefore, they are widely used in the manufacturing of semiconductor wafers, electronic and electrical devices such as smartphones and tablet PCs, and display devices such as displays. In particular, in recent years, during semiconductor wafer processing and the assembly of electronic and electrical devices and displays, there is a need to temporarily fix components and protective films with relatively weak adhesive force, and then peel the temporarily fixed components from the adhesive as the process progresses. This has led to a demand for compositions that form a slightly tacky adhesive compared to conventional organopolysiloxane adhesive compositions.

[0003] In particular, in recent years, in the processing of semiconductor wafers, adhesive sheets are used in the dicing, pickup, and mounting processes, which involve grinding the back surface of the wafer. These processes require different levels of adhesion: some require strong adhesion, while others require easy peeling. Specifically, in the back surface grinding process of the semiconductor wafer, the adhesive sheet must adhere firmly to the semiconductor wafer without peeling off in order to protect the pattern surface of the semiconductor wafer. Furthermore, it must be easily peeled off the semiconductor wafer after grinding. Similarly, in the dicing process of the semiconductor wafer, high adhesion is required to prevent the cut and separated element pieces from peeling off the adhesive sheet. On the other hand, in the pickup process, the cut and separated element pieces must be easily peeled off the adhesive sheet. In other words, low adhesion is required for the adhesive sheet.

[0004] However, there is a trade-off between adhesive strength for fixing and protection and the ease of removal of the material. If a weakly adhesive material is used, the adhesive strength may be insufficient in processes where strong adhesion is required, such as temporary fixing, which can lead to process defects. On the other hand, if the adhesive strength is too high, it may become difficult to remove in subsequent processes, or problems may arise with process defects due to adhesive residue caused by the breakdown of the aggregate layer. For this reason, there is a need for an adhesive that has sufficient adhesive strength for processes such as temporary fixing, and that can be removed from the substrate very easily in subsequent processes.

[0005] On the other hand, in fields such as film materials and electrode materials, active energy ray curing type re-peelable adhesives have been proposed (for example, Patent Documents 1-3). These adhesives, by using acrylic copolymers or polyurethane copolymers, can significantly change their tackiness before and after active energy ray irradiation, exhibiting high tackiness before irradiation and high peelability after irradiation. However, because the adhesives described in these documents have an organic molecular framework, there is room for improvement, particularly in terms of heat resistance and durability, when used for applications aimed at protecting substrates during processing.

[0006] Furthermore, the above-mentioned literature does not describe or suggest anything about organopolysiloxane compounds having a linear (linear and branched) molecular structure that provides a viscosity suitable for coating as a raw material for adhesives, which are equipped with (meth)acrylic functional groups and other aliphatic unsaturated carbon-carbon bond-containing groups in a certain ratio, nor does it describe the use of such comodified organopolysiloxane compounds equipped with multiple curing-reactive functional groups in a curing reaction mechanism including a hydrosilylation reaction, nor does it describe or suggest any characteristics of adhesive compositions containing these compounds and their curing (particularly the two-step curing properties and changes in adhesive strength).

[0007] On the other hand, Patent Document 4 proposes an organopolysiloxane composition comprising an organopolysiloxane compound containing a (meth)acrylic functional group, a platinum-based catalyst, and a photoinitiator, which allows for curing reactions by photopolymerization and addition reactions, and exhibits excellent heat resistance, discoloration resistance, and low tack, as well as a sealant comprising the organopolysiloxane composition and its cured product. However, the same document does not specifically disclose a comodified organopolysiloxane containing a (meth)acrylic functional group and an alkenyl group, and in particular, it does not describe or suggest anything about the characteristics of an adhesive composition containing a comodified organopolysiloxane containing both in a specific ratio, or its curing (especially the two-stage curing properties and changes in adhesive strength). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2012-012545 [Patent Document 2] Japanese Patent Publication No. 2012-136678 [Patent Document 3] Japanese Patent Publication No. 2013-166877 [Patent Document 4] Japanese Patent Publication No. 2013-203794 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention has been made to solve the above problems, and aims to provide an organopolysiloxane compound that serves as a raw material for an organopolysiloxane adhesive that has sufficient adhesive strength in processes such as temporary fixing, and that can be peeled off from the substrate very easily in subsequent processes. Furthermore, the present invention aims to provide a curable organopolysiloxane composition containing the organopolysiloxane compound, an organopolysiloxane adhesive composition containing the same, and a method for using the organopolysiloxane adhesive composition. [Means for solving the problem]

[0010] The present inventors have diligently studied the above problems and arrived at the present invention. Specifically, the problems of the present invention can be solved by a chain-like comodified organopolysiloxane containing a silicon atom bonded functional group containing a specific acrylic group or methacrylic group, and a silicon atom bonded functional group containing at least one aliphatic unsaturated carbon-carbon bond such as an alkenyl group in the molecule. Furthermore, the problems of the present invention can be solved by a curable organopolysiloxane composition and an organopolysiloxane adhesive composition containing the above-mentioned comodified organopolysiloxane.

[0011] The comodified organopolysiloxane according to the present invention possesses both heat-curing and photocuring properties. By forming a semi-cured adhesive layer containing the comodified organopolysiloxane through a heat-curing reaction, and then performing a photocuring reaction to fully cure it, the adhesive strength of the adhesive layer to the substrate is significantly reduced before and after the photocuring reaction. As a result, the adhesive layer according to the present invention has sufficient adhesive strength after heat curing, and by subsequently irradiating it with high-energy rays for photocuring, the adhesive strength can be reduced, making it possible to achieve easy peelability. [Effects of the Invention]

[0012] The present invention provides an organopolysiloxane compound that serves as a raw material for an organopolysiloxane adhesive, which is a chain-like comodified organopolysiloxane possessing both heat-curing and photocuring properties, wherein the semi-cured product after heat curing has sufficient adhesive strength, and the cured product after the photocuring reaction is extremely easily peelable from the substrate. Furthermore, the present invention can provide a curable organopolysiloxane composition containing the organopolysiloxane compound, and in particular, can provide an organopolysiloxane adhesive composition and a method of using the same, in which the adhesive strength of the adhesive layer to the substrate is significantly reduced before and after the photocuring reaction, thereby achieving easy peelability.

[0013] In particular, the curable organopolysiloxane composition containing the comodified organopolysiloxane according to the present invention has a coatable viscosity, excellent curability, and upon curing reaction, can provide a cured product (especially a cured film) with good adhesion to a substrate and excellent transparency. Furthermore, the present invention makes it possible to realize a silicone-based adhesive layer / adhesion layer whose adhesive strength changes before and after the photocuring reaction, and can provide a method for manufacturing and protecting such a protective component for use in a wide range of applications, as well as equipment or devices equipped with them. [Modes for carrying out the invention]

[0014] [(A) Covariant organopolysiloxane] The comodified organopolysiloxane according to the present invention is a chain-like polysiloxane molecule, which may be linear or have a branched chain structure with some branching. Such a comodified organopolysiloxane has R3SiO at the end of the molecular chain. 1 / 2 It has siloxane units (M units) represented by , and its main chain is essentially R2SiO 2 / 2 RSiO is composed of siloxane units (D units) represented by , which give a branched structure to a part of the main chain. 3 / 2 Siloxane units (T units) and / or SiO are represented by siloxane units (T units) and / or SiO 4 / 2It may have a siloxane unit (Q unit) represented by, and within a range that does not impair the technical effects of the present invention, it may have a divalent linking group such as a silylene bond between some of the siloxane units. Each of the above Rs is independently a monovalent organic group, and among all the Rs, at least one is a silicon atom-bonded functional group (R A ) containing an acrylic group or a methacrylic group described later, and at least one is a silicon atom-bonded functional group (R Vi ) containing at least 1 aliphatic unsaturated carbon-carbon bond (however, excluding the functional group that is the above R A ). From the viewpoint of the crosslinking reactivity, it is preferable that at least two of the Rs in all the siloxane units constituting the copolymerizable organopolysiloxane are silicon atom-bonded functional groups (R OH ).

[0015] Preferably, the copolymerizable organopolysiloxane according to the present invention has a linear or branched polysiloxane structure in which 90 mol% or more of all the siloxane units excluding the molecular chain ends are D units, and 95 to 100 mol% are D units, and it is particularly preferable that it is a linear copolymerizable organopolysiloxane. The linear polysiloxane structure is composed only of the M units at both ends and the D units constituting the main chain.

[0016] The copolymerizable organopolysiloxane according to the present invention is not particularly limited in its siloxane polymerization degree, but from the viewpoint of giving a viscosity that can be applied to a curable organopolysiloxane composition containing this, the siloxane polymerization degree is preferably in the range of 10 to 10,000, and more preferably in the range of 25 to 2,000. When using a resinous organopolysiloxane containing a large amount of the above T units and Q units and a highly polymerized organopolysiloxane, it may be difficult to apply the curable composition.

[0017] Such a copolymerizable organopolysiloxane is composed of the above siloxane units, Formula: M (2+m+2p) D n T m Qp This is expressed as follows: In the formula, n is a positive number, n and m are 0 or positive numbers, the total number of siloxane units (i.e., the degree of polymerization of siloxane), "2+m+2p+n+m+p", is a number in the range of 10 to 10,000, and at least 90 mol% of all siloxane units except the terminal M units are D units. Note that in the case of a linear polysiloxane structure, the comodified organopolysiloxane according to the present invention is MD n It is represented as M, and n+2 is a number in the range of 10 to 10,000.

[0018] The comodified organopolysiloxane according to the present invention contains a silicon atom bonded functional group (R) containing an acrylic group or a methacrylic group within its molecule. A ), and silicon atom bonding functional groups (R) containing at least one aliphatic unsaturated carbon-carbon bond Vi )(However, the above R A It is characterized by containing (excluding the functional group that is a silicon atom bonded functional group (R A ) is a functional group that exhibits photocurability upon irradiation with high-energy rays in the presence of a photoradical polymerization initiator, and is a silicon atom bonded functional group (R Vi ) is a functional group that exhibits heat-curability in the presence of a hydrosilylation reaction catalyst. The comodified organopolysiloxane according to the present invention has both heat-curable and photocurable silicon atom bonded functional groups within the same molecule. Therefore, the adhesive layer consisting of the semi-cured product after the heat-curing reaction has high initial adhesive strength, and by irradiating the semi-cured product with high-energy rays, the adhesive strength is greatly reduced, making it possible to achieve easy peelability.

[0019] In order to achieve the property of changing adhesive properties to an easily peelable cured product upon irradiation with high-energy rays, the comodified organopolysiloxane according to the present invention has a silicon atom bonding functional group (R) containing an acrylic group or a methacrylic group attached to all functional groups (all R in each siloxane unit) that are bonded to the silicon atoms constituting the polysiloxane. AIt may contain 0.10 to 10.0 mol%, preferably in the range of 0.20 to 5.0 mol%, and more preferably in the range of 0.30 to 5.0 mol%. Furthermore, from the viewpoint of providing a semi-cured product with excellent initial adhesive strength through a heat curing reaction, the molecule contains a silicon atom bond functional group (R) which contains at least one aliphatic unsaturated carbon-carbon bond. Vi )(However, the above R A (Excluding functional groups that are) Silicon atom bonded functional groups (R) containing acrylic or methacrylic groups per mole A ) contains in an average amount of 2.0 to 50.0 moles, preferably in a range of 2.0 to 10.0 moles. Photocurable silicon atom bonded functional group (R A If the content of (R) is below the lower limit, the photocuring reaction may not proceed sufficiently, and the adhesive properties may not change to an easily peelable cured product. If the content exceeds the upper limit, side reactions and discoloration problems may occur. In addition, heat-curable (hydrosilylation reactive) silicon atom bonded functional groups (R) Vi If the content of ) is below the lower limit, sufficient initial adhesive properties may not be achieved, and conversely, if the content exceeds the upper limit, there will be an excess of carbon-carbon double bond sites such as vinyl groups, which may prevent the adhesive properties from changing to easily peelable cured products, or it may harden too strongly and not provide adhesiveness. Furthermore, from the standpoint of crosslinking reactivity, at least two of all functional groups (all R in each siloxane unit) that are bonded to the silicon atoms constituting the polysiloxane are silicon atom bonded functional groups (R Vi ) is preferable.

[0020] Here, a silicon atom bonded functional group (R) containing an acrylic group or a methacrylic group A )teeth, General formula (1): [ka] It is expressed by the following equation. In the equation, R 1The atoms are independently a hydrogen atom, a methyl group, or a phenyl group, and are preferably a hydrogen atom or a methyl group because they form an acrylic group or a methacrylic group moiety. Z is a divalent organic group that may contain a heteroatom and is bonded to a silicon atom constituting the main chain of the polysiloxane *, and may be a divalent organic group that may contain an oxygen atom, a nitrogen atom, or a sulfur atom.

[0021] Specifically, Z is, Alkylene groups with 2 to 22 carbon atoms, -R 3 -C(=O)-OR 4 - A divalent organic group represented by {wherein R 3 R is an alkylene group with 2 to 22 carbon atoms. 4 { is a group selected from ethylene, propylene, methylethylene, or hexylene groups}, and -Z 1 -XC(=O)-XZ 2 - A divalent organic group represented by {in the formula, Z 1 is -O(CH2) k - (where k is a number in the range of 0 to 3), and X represents an oxygen atom, nitrogen atom, or sulfur atom. Z 2 -[(CH2)2O] is bonded to the silicon atoms that make up the main chain of the polysiloxane, which is *. m (CH2) n - (where m is a number in the range of 0 to 3, and n is a number in the range of 3 to 10) is a divalent organic group. It is preferable that the group is selected from among them.

[0022] Particularly preferred are silicon atom bonded functional groups (R A ) is the general formula (1-1): [ka] It is expressed as follows: In the formula, R 1 R independently represents a hydrogen atom, a methyl group, or a phenyl group, with a hydrogen atom or a methyl group being preferred. 2These independently represent an alkyl group or an aryl group, which is industrially preferably an alkyl group or phenyl group having 1 to 20 carbon atoms, and particularly preferably a methyl group. 1 is -O(CH2) m -(m is a number in the range of 0 to 3), and m is preferably 1 or 2. 2 * is a -(CH2) bonded to the silicon atom that makes up the main chain of polysiloxane. n A divalent organic group represented by -(n is a number in the range of 3 to 10), where n is practically preferred to be 2 to 6. Note that a silicon atom bonded functional group (R) represented by general formula (1-1) is also preferred. A ) is a silicon atom bonded functional group (R) containing at least one alkenyl group. Vi The molecule can be introduced into the molecule by reacting a hydrosilane compound having a silicon-bonded hydrogen atom and a (meth)acrylic functional group within the molecule (for example, 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate, etc.) in the presence of a hydrosilylation catalyst. Furthermore, this reaction may and preferably be carried out in the presence of a polymerization inhibitor such as dibutylhydroxytoluene (BHT).

[0023] A silicon atom bond functional group (R) containing at least one aliphatic unsaturated carbon-carbon bond Vi ) is an organic group containing one or more aliphatic unsaturated carbon-carbon bonds that are capable of addition reactions, represented by an aliphatic carbon-carbon double bond (C=C), and is a component that imparts hydrosilylation reactivity and heat curability to the comodified organopolysiloxane according to the present invention. However, silicon atom bonded functional group (R Vi The range of ) includes silicon atom bonded functional groups (R) containing the aforementioned acrylic group or methacrylic group. A ) is not included, R Vi and R A These are different functional groups. In particular, from the viewpoint of crosslinking reactivity, the comodified organopolysiloxane according to the present invention has at least two silicon atom bonded functional groups (R) within the molecule. Vi It is preferable that it includes ).

[0024] Silicon atom bond functional group (RVi The group is preferably an alkenyl group having 2 to 20 carbon atoms, with examples including vinyl, allyl, butyl, and hexenyl groups, and a hexenyl group (C6) is particularly preferred from the viewpoint of crosslinking reactivity.

[0025] In the comodified organopolysiloxane according to the present invention, the above silicon atom bonded functional group (R A ) and silicon atom bonded functional group (R Vi ) may be bonded to silicon atoms at the end of the chain of the linear siloxane, or it may be a side-chain modifying group bonded to silicon atoms on the polysiloxane main chain. Furthermore, the comodified organopolysiloxane according to the present invention may be alone, and the degree of polymerization of the siloxane, the above R A and R Vi It may also be a mixture of two or more comodulated organopolysiloxanes having different denaturation rates, main chain structures, or terminal structures.

[0026] In the comodified organopolysiloxane according to the present invention, the above silicon atom bonded functional group (R A ) and silicon atom bonded functional group (R Vi Other organic groups (hereinafter referred to as "other organic groups") may include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl groups; aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups such as benzyl and phenethyl groups; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl groups. From an industrial standpoint, the inclusion of a methyl group is particularly preferable.

[0027] [(A) Use of comodified organopolysiloxanes] The comodified organopolysiloxane according to the present invention possesses both heat-curability via hydrosilylation reaction and photocurability via irradiation with high-energy rays, making it suitable as a raw material for curable organopolysiloxane compositions that cure through multiple curing mechanisms or two or more curing steps. Furthermore, the comodified organopolysiloxane according to the present invention has a coating viscosity, and the semi-cured product obtained by the heat curing reaction exhibits excellent initial adhesion to the substrate, and this adhesion to the substrate is further enhanced by irradiation with high-energy rays, which removes unreacted silicon atom bonded functional groups (R A Because it forms an easily peelable cured layer by a photocuring reaction and its adhesive strength decreases significantly, it is particularly useful as a raw material for organopolysiloxane adhesive compositions and adhesive layers characterized by changes in adhesive strength triggered by irradiation with high-energy rays.

[0028] [Curable organopolysiloxane composition] The curable organopolysiloxane composition according to the present invention contains the above-mentioned (A) comodified organopolysiloxane and possesses both heat curability by hydrosilylation reaction and photocurability by irradiation with high-energy rays.

[0029] More specifically, the curable organopolysiloxane composition according to the present invention is (A) Comodified organopolysiloxane according to the present invention (B) Organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in the molecule, (C) Hydrosilylation reaction catalyst, and (D) Photoradical polymerization initiator It contains, and optionally, further, (E)(E) R3SiO in the molecule 1 / 2 Siloxane units (M units) represented by (wherein R independently represents a monovalent organic group), and SiO 4 / 2 Organopolysiloxane resin containing siloxane units (Q units) represented by the formula, with a ratio of M units to Q units in the range of 0.5 to 2.0. (F) Polydimethylsiloxane which may optionally have an alkenyl group, and (G) Organic solvents It may contain the following. Components (B) to (G) are described below.

[0030] [(B) Organohydrogenpolysiloxane] Component (B) is an organohydrogenpolysiloxane having at least two or more silicon-bonded hydrogen atoms in one molecule, and is a component that functions as a crosslinking agent for the above-mentioned curable organopolysiloxane composition. Specifically, it is a silicon atom-bonding functional group (R) containing at least one aliphatic unsaturated carbon-carbon bond in component (A). Vi (R) reacts with (C) a hydrosilylation reaction catalyst to form a semi-cured adhesive layer. This adhesive layer has excellent initial adhesion to the substrate, while the unreacted photocurable silicon atom bonded functional group (R) A Because it contains ), the adhesive strength is greatly reduced by a two-stage curing process triggered by irradiation with high-energy rays, resulting in easy peeling.

[0031] Such component (B) may be at least one selected from cyclic organohydrogenpolysiloxanes having at least three silicon-bonded hydrogen atoms in the molecule, and linear or branched organohydrogenpolysiloxanes having at least two or more silicon-bonded hydrogen atoms in the molecule. Alternatively, component (B) may be a mixture of two or more of the above organohydrogenpolysiloxanes.

[0032] Examples of cyclic organohydrogenpolysiloxanes include the following formula: [(R 3 HSiO) m3 (R 3 2SiO) m4 ] It is expressed as follows: Here, m3 + m4 are numbers in the range of 3 to 20, m3 is a number greater than or equal to 3, and m4 is a number greater than or equal to 0. 3 R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, excluding alkenyl groups. 2 Similar groups can be exemplified, preferably a methyl group or a phenyl group.

[0033] The linear or branched organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in the molecule is an organohydrogenpolysiloxane such as a polyorganohydrogensiloxane or organohydrogensiloxane-diorganosiloxane copolymer, in which the side chain portion has at least two silicon-bonded hydrogen atoms and the molecular chain ends are sealed with a trialkylsiloxy group, an aryldialkylsiloxy group, etc. The degree of siloxane polymerization is in the range of 5 to 500, and preferably in the range of 5 to 200.

[0034] Specifically, component (B) includes 1,3,5,7-tetramethylcyclotetrasiloxane, tris(dimethylhydrogensiloxy)methylsilane, tris(dimethylhydrogensiloxy)phenylsilane, 1-(3-glycidoxypropyl)-1,3,5,7-tetramethylcyclotetrasiloxane, 1,5-di(3-glycidoxypropyl)-1,3,5,7-tetramethylcyclotetrasiloxane, 1-(3-glycidoxypropyl)-5-trimethoxysilylethyl-1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogenpolysiloxane with trimethylsiloxy groups sealed at both ends of the molecular chain, and dimethylsiloxane / methylhydrogensiloxane copolymer with trimethylsiloxy groups sealed at both ends of the molecular chain. Examples include dimethylpolysiloxane with dimethylhydrogensiloxy groups sealed at both ends of the molecular chain, methylhydrogensiloxane / diphenylsiloxane copolymer with trimethylsiloxy groups sealed at both ends of the molecular chain, methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer with trimethylsiloxy groups sealed at both ends of the molecular chain, methyltris(dimethylsiloxy)silane, tetrakis(dimethylsiloxysilane), methylhydrogenpolysiloxane with trimethylsiloxy groups sealed at the end of the molecular chain, methylhydrogensiloxane / dimethylsiloxane copolymer with trimethylsiloxy groups sealed at the end of the molecular chain, and methylhydrogensiloxane / methylphenylsiloxane copolymer with trimethylsiloxy groups sealed at the end of the molecular chain.

[0035] The amount of component (B) used can be appropriately selected according to the desired adhesive strength and curing characteristics, but from the standpoint of initial adhesive strength and easy peeling triggered by irradiation with high-energy rays, which are the issues of the present invention, the range of 0.1 to 5 parts by mass, more preferably 0.5 to 4.5 parts by mass, and particularly preferably 1.0 to 3.5 parts by mass, per 100 parts by mass of the comodified organopolysiloxane which is component (A) above. If the amount of component (B) used is less than the lower limit, there may be insufficient crosslinking agent, resulting in insufficient heat curing properties of the composition, and if it exceeds the upper limit, the change in adhesive strength of the adhesive layer before and after irradiation with high-energy rays will be small, and the objective of the present invention may not be achieved. Furthermore, preferably, the amount of component (B) used is such that the number of moles of silicon-bonded hydrogen atoms in component (B) relative to the number of moles of aliphatic unsaturated carbon-carbon bonds such as alkenyl groups in the composition (hereinafter referred to as the "SiH / Vi ratio") is in the range of 0.1 to 40, more preferably in the range of 0.5 to 30, and even more preferably in the range of 1.0 to 30. Within this range, the overall crosslinking density is appropriately adjusted, making it possible to exhibit desired properties regarding the storage modulus and adhesion of the cured product. On the other hand, if the SiH / Vi ratio is below the lower limit, it may cause adhesive residue when the cured product is adhered to the substrate, and if it exceeds the upper limit, there may be an excess of unreacted SiH groups, which may cause the adhesion properties of the cured product to become unstable.

[0036] [(C) Hydrosilylation reaction catalyst] Component (C) is a hydrosilylation catalyst that, upon heating or other means, promotes the hydrosilylation reaction between component (A), alkenyl groups, and other aliphatic unsaturated carbon-carbon bonds in component (A) and other optional components, and component (B).

[0037] Examples of hydrosilylation reaction catalysts include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, with platinum-based catalysts being preferred because they significantly accelerate the hardening of the composition. Examples of platinum-based catalysts include platinum fine powder, chloroplatinic acid, an alcoholic solution of chloroplatinic acid, platinum-alkenylsiloxane complexes, platinum-olefin complexes, and platinum-carbonyl complexes, with platinum-alkenylsiloxane complexes being particularly preferred. Examples of this alkenylsiloxane include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, alkenylsiloxanes in which some of the methyl groups of these alkenylsiloxanes are substituted with groups selected from the group consisting of nitriles, amides, dioxolanes, and sulfolanes, as well as ethyl groups, phenyl groups, etc., and alkenylsiloxanes in which the vinyl groups of these alkenylsiloxanes are substituted with allyl groups, hexenyl groups, etc. In particular, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane is preferred due to the good stability of this platinum-alkenylsiloxane complex, and it is preferable to add it in the form of an alkenylsiloxane solution. In addition, from the viewpoint of improving handling ease and the pot life of the composition, these hydrosilylation reaction catalysts may be thermoplastic resin fine particles containing hydrosilylation reaction catalysts, particularly thermoplastic resin fine particles containing platinum-containing hydrosilylation reaction catalysts, which are catalysts dispersed or encapsulated in thermoplastic resins such as silicone resins, polycarbonate resins, and acrylic resins. Non-platinum metal catalysts such as iron, ruthenium, and iron / cobalt may be used as catalysts to promote the hydrosilylation reaction.

[0038] The thermoplastic resin fine particles containing a platinum-based hydrosilylation reaction catalyst usable in this invention may be either fine particles in which a hydrosilylation reaction catalyst such as a platinum-based catalyst is dissolved or dispersed in the thermoplastic resin, or microcapsule fine particles in which a hydrosilylation reaction catalyst such as a platinum-based catalyst is contained as a nucleus within a thermoplastic resin shell. The thermoplastic resin that forms the wall material preferably has a glass transition temperature (Tg) of 75°C or higher, more preferably 80°C or higher, and particularly preferably in the range of 80 to less than 250°C. Such thermoplastic resins may be used alone or in combination. The average particle size of the thermoplastic resin fine particles containing a hydrosilylation reaction catalyst is not limited, but is preferably in the range of 0.1 to 500 μm, and more preferably in the range of 0.3 to 100 μm.

[0039] In the present invention, the content of the hydrosilylation reaction catalyst is not particularly limited, but the amount of platinum-based metal is in the range of 0.1 to 200 ppm relative to the total amount of solids in the composition, and may be in the range of 0.1 to 150 ppm, 0.1 to 100 ppm, or 0.1 to 50 ppm. Here, platinum-based metal is a group VIII metal element consisting of platinum, rhodium, palladium, ruthenium, and iridium, but in practical terms, it is preferable that the content of platinum metal excluding the ligand of the hydrosilylation reaction catalyst is in the above range. The solids refer to the components that form the hardened layer when the curable organopolysiloxane composition according to the present invention is cured (mainly the main agent, adhesion-enhancing components, crosslinking agents, catalysts, and other non-volatile components), and do not include volatile components such as solvents that volatilize during heat curing.

[0040] When the platinum-based metal content in the curable organopolysiloxane composition according to the present invention is 50 ppm or less (45 ppm or less, 35 ppm or less, 30 ppm or less, 25 ppm or less, or 20 ppm or less), discoloration and staining of the transparent adhesion layer can be suppressed, especially after curing or when exposed to high-energy rays such as heating or ultraviolet light. On the other hand, from the standpoint of curability of the organopolysiloxane composition, the platinum-based metal content should be 0.1 ppm or more, and if it falls below this lower limit, it may cause curing failure.

[0041] The curable organopolysiloxane composition of the present invention may optionally contain a curing retarder. The curing retarder is added to suppress the crosslinking reaction between the aliphatic unsaturated carbon-carbon bond-containing group and the silicon bond hydrogen atom in the composition, thereby extending the pot life at room temperature and improving storage stability. Therefore, in practical terms, it is an almost essential component of the curable organopolysiloxane composition of the present invention.

[0042] Specifically, curing retarders include acetylene compounds, enyne compounds, organic nitrogen compounds, organophosphorus compounds, oxime compounds, and phosphorus compounds. Specifically, examples include alkyne alcohols such as 3-methyl-1-butyne-3-ol, 3,5-dimethyl-1-hexyne-3-ol, 3-methyl-1-pentin-3-ol, 1-ethynyl-1-cyclohexanol, and phenylbutynol; enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-1-hexyne-3-yne; methylalkenylcyclosiloxanes such as 2-ethynyl-4-methyl-2-pentene, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane; and benzotriazoles.

[0043] The phosphorus-containing hydrosilylation reaction retarder may be at least one selected from the group consisting of phosphine compounds, phosphate compounds, phosphonic acid compounds, phosphine oxide compounds, phosphite compounds, and phosphonic acid compounds. Examples include components described in Japanese Patent Publication No. 2007-308542, such as 1,3-bis(diphenylphosphin)propane.

[0044] From the viewpoint of the curing behavior of the composition, it is preferable that the curable organopolysiloxane composition of the present invention exhibits a viscosity increase of no more than 1.5 times after 8 hours at room temperature following preparation of the composition, and is curable at 80-200°C. Suppression of viscosity increase is important from the viewpoint of handling workability, pot life, and post-curing properties, as curability can be ensured by curing at a certain high temperature (80-200°C). Such a composition can be realized by selecting a suitable combination and amount of each of the above components, a hydrosilylation catalyst, and a curing retarder.

[0045] [(D) Photoradical polymerization initiator] Component (D) is a photoradical polymerization initiator, and upon irradiation with high-energy rays, the silicon atom bond functional group (R) in component (A) A It is a component that promotes the photocuring reaction of the acrylic or methacrylic group of ) in particular. A By irradiating an adhesive layer consisting of a semi-cured material containing ) with high-energy rays, the adhesive strength of the adhesive layer to the substrate is greatly reduced, forming an easily peelable cured material.

[0046] Photoradical polymerization initiators are broadly classified into photocleavage type and hydrogen abstraction type, but the photoradical polymerization initiator used in the composition of the present invention can be arbitrarily selected from those known in the art and is not particularly limited to any specific one. Examples of photoradical polymerization initiators include α-ketol compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenyl ketone; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; and ketal compounds such as benzyldimethyl ketal. Examples include: aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; acylphosphinoxides; acylphosphonates, etc.

[0047] The amount of component (D) used is the silicon atom bond functional group (R) derived from component (A). A The amount can be appropriately designed depending on the content of (A), the desired change in adhesive strength of the cured product triggered by irradiation with high-energy rays, and the ease of peeling, but it is preferably 0.1 to 20 parts by mass per 100 parts by mass of component (A), and particularly preferably 0.5 to 15 parts by mass.

[0048] [(D') Photosensitizer] Optionally, (D') a photosensitizer can be used in combination with (D) a photoradical polymerization initiator. The use of a sensitizer can increase the photon-quantum efficiency of the polymerization reaction, and compared to using only a photoinitiator, it allows longer wavelength light to be used in the polymerization reaction. This is known to be particularly effective when the coating thickness of the composition is relatively thick or when a relatively long wavelength LED light source is used. Known sensitizers include anthracene compounds, phenothiazine compounds, perylene compounds, cyanine compounds, merocyanine compounds, coumarin compounds, benzylidene ketone compounds, (thio)xanthene or (thio)xanthone compounds, such as isopropylthioxanthone, 2,4-diethylthioxanthone, squarium compounds, (thia)pyrillium compounds, and porphyrin compounds. However, any photosensitizer is not limited to these and can be used in the curable organopolysiloxane composition and adhesive composition of the present invention. The amount used is arbitrary, but the mass ratio of component (D') to component (D) should be in the range of 0 to 10. When using it, it is generally recommended to select a range of 0.01 to 5.

[0049] [(E) Organopolysiloxane resin] The composition according to the present invention may contain (E) an organopolysiloxane resin in addition to components (A) to (D). Component (E) is an optional component for adjusting adhesion to the substrate, and the hardness of the semi-cured product after the hydrosilylation reaction and its adhesion to the substrate can be adjusted according to the amount of this component used.

[0050] (a)R3SiO 1 / 2 Siloxane units (M units) represented by (wherein R independently represents a monovalent organic group), and (b) SiO 4 / 2 This is an organopolysiloxane resin containing siloxane units (Q units) represented by [formula]. The molar ratio of M units to Q units is preferably 0.5 to 2.0. If this molar ratio is less than 0.5, the adhesion of the cured product to the substrate may decrease, and if it is greater than 2.0, the cohesive force of the material constituting the adhesion layer decreases.

[0051] In particular, the molar ratio of (a) M units to (b) Q units is preferably in the range of M units:Q units = 0.50:1.00 to 1.50:1.00, more preferably in the range of 0.55:1.00 to 1.20:1.00, and even more preferably 0.60:1.00 to 1.10:1.00. The above molar ratio is, 29 This can be easily measured using Si nuclear magnetic resonance.

[0052] (E) The general unit formula for component (E) is: (R3SiO 1 / 2 ) a (SiO 4 / 2 ) b It is preferable that the organopolysiloxane resin is represented by the formula (wherein R is a monovalent organic group independently of each other, a and b are positive numbers, a+b=1 and a / b=0.5~1.5).

[0053] Component (E) may consist only of (a) M units and (b) Q units, but R2SiO 2 / 2 Units (D units), and / or RSiO 3 / 2 It may contain units (T units). In the formula, R independently represents a monovalent organic group. The total content of (a) M units and (b) Q units in component (E) is preferably 50% by weight or more, more preferably 80% by weight or more, and particularly preferably 100% by weight.

[0054] The monovalent organic group is not particularly limited, but it is a silicon atom bonded functional group (R) in component (A) above that contains an acrylic group or a methacrylic group, represented by general formula (1). A ), a silicon atom bond functional group containing at least one aliphatic unsaturated carbon-carbon bond (R Vi )(However, the above R AIt may be one or more organic groups selected from functional groups (excluding those that are ) and other organic groups such as methyl groups. Furthermore, component (E) may contain hydrolyzable groups such as hydroxyl groups or alkoxy groups, and may be an organopolysiloxane resin in which the content of hydroxyl groups or hydrolyzable groups is reduced by hydrolyzing these hydrolyzable groups with a silylating agent such as trimethylsilane.

[0055] Since component (E) is an optional component, it can be added in an amount of 0.0 to 150 parts by mass per 100 parts by mass of component (A), preferably 0.5 to 50 parts by mass, and particularly preferably in the range of 1.0 to 20 parts by mass.

[0056] [(F) Polydimethylsiloxane which may optionally have an alkenyl group] The composition according to the present invention may further contain a polydimethylsiloxane which may optionally have alkenyl groups. Although such component (F) does not participate in the crosslinking reaction by components (A) to (D) and any component (E), using this component can adjust the viscosity, tackiness, hardness, crosslinking density, etc. of the curable organopolysiloxane composition required for coating, as well as improve the peelability of the cured or semi-cured product, etc.

[0057] Here, components (A) and (E) are explicitly excluded from the range of component (F), and preferred component (F) is a cyclic, linear, branched, resinous, and natural rubbery polydimethylsiloxane in which some of the methyl groups may be substituted with alkenyl groups having 2 to 20 carbon atoms. The degree of polymerization and viscosity range of the siloxane are not particularly limited, but the viscosity at 25°C may be in the range of 1.5 to 1,000,000 mPa·s, and it may be a liquid polydimethylsiloxane having a viscosity of 100,000 mPa·s or more at 25°C, or a natural rubbery polydimethylsiloxane having a plasticity in the range of 50 to 200, measured according to the method specified in JIS K6249 (the thickness when a 4.2 g spherical sample is subjected to a load of 1 kgf for 3 minutes at 25°C is read to 1 / 100 mm, and this value is multiplied by 100). Furthermore, the content of the vinyl (CH2=CH) portion in the alkenyl group within component (F) (hereinafter referred to as "vinyl content") is arbitrary, but may be in the range of 0.000 to 0.400% by mass, or in the range of 0.005 to 0.300% by mass. Note that cyclic polydimethylsiloxanes with a degree of polymerization of 3 to 20, which may optionally have alkenyl groups, are included in the range of component (F).

[0058] [(G) Thiol compounds] The composition according to the present invention may further contain (G) a polyfunctional thiol compound having at least two or more thiol groups in the molecule. The polyfunctional thiol compound acts as a chain transfer agent, promoting radical polymerization reactions, thereby improving the curing rate and deep curing properties of the cured product even at low UV irradiation levels, and also functions as a crosslinking point in the composition.

[0059] Examples of such polyfunctional thiol compounds include pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinan-2,4,6-trione, trimethylolpropanetris(3-mercaptobutyrate), and others.

[0060] The use of component (G) is optional, but the amount used should be 0 to 20 parts by mass, preferably 0 to 10 parts by mass, and particularly preferably 0 to 5 parts by mass, relative to 100 parts by mass of component (A).

[0061] [(H) Organic solvents] Since the components of the composition according to the present invention have relatively low viscosity, low-solvent or solvent-free compositions can be designed, but (H) organic solvents may be optionally included. The organic solvent may be used as a diluent to disperse or dissolve each component in order to improve the coating properties and wettability of the composition to the substrate, or it may be a component that is inevitably included as a solvent accompanying other raw material components.

[0062] The organic solvents that can be used in the present invention are not particularly limited in type, as long as they do not impair the technical effects of the present invention, and are compounds that can dissolve all or some of the constituent components of the composition. Preferably, those with a boiling point of 80°C or higher and 200°C or lower are used. The types of solvents may be non-halogenated solvents or halogenated solvents, and include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ester solvents, alcohol solvents, ether solvents, chlorinated aliphatic hydrocarbon solvents, and solvent volatile oils. Two or more types may be combined depending on the coating properties and wettability.

[0063] More specifically, i-propyl alcohol, t-butyl alcohol, cyclohexanol, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, benzene, heptane, hexane, octane, isoparaffin, mesitylene, 1,4-dioxane, dibutyl ether, anisole, 4-methylanisole, ethylbenzene, ethoxybenzene, ethylene glycol, diisopropyl ether, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 2-methoxyethanol (ethylene glycol monomethyl ether), diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, dipropyl Examples of non-halogenated solvents include methyl ether acetate, ethyl acetate, butyl acetate, propyl propionate (=propyl propionate), 1-methoxy-2-propyl acetate, 1-ethoxy-2-propyl acetate, octamethylcyclotetrasiloxane, and hexamethyldisiloxane, as well as halogenated solvents such as trichloroethylene, perchloroethylene, methylene chloride, trifluoromethylbenzene, 1,2-bis(trifluoromethyl)benzene, 1,3-bis(trifluoromethyl)benzene, 1,4-bis(trifluoromethyl)benzene, trifluoromethylchlorobenzene, trifluoromethylfluorobenzene, and hydrofluoroethers.

[0064] The organic solvent content is preferably 0 to less than 60% by mass, less than 50% by mass, and substantially within the range of 0 to 30% by mass, based on 100 parts by mass of the entire composition. In particular, when using components (A) to (D) of the present invention, and optionally (F) or (G), the solid content concentration that forms solids by the curing reaction can be easily designed to be within the range of 30 to 100% by mass of the entire composition.

[0065] [Other optional components] The curable organopolysiloxane composition according to the present invention may optionally contain components other than those listed above, as long as the technical effects of the present invention are not impaired. For example, it may contain: adhesion promoters; non-reactive organopolysiloxanes such as polydimethyldiphenylsiloxane other than component (F); antioxidants such as phenolic, quinoneic, amineic, phosphorusic, phosphiteic, sulfuric, or thioetheric agents; light stabilizers such as triazoleic or benzophenoneic agents; flame retardants such as phosphate esteric, halogenic, phosphorusic, or antimonyic agents; and one or more antistatic agents such as cationic surfactants, anionic surfactants, or nonionic surfactants. In addition to these components, pigments, dyes, inorganic fine particles (reinforcing fillers, dielectric fillers, conductive fillers, thermally conductive fillers), etc. may also be optionally added.

[0066] The method for preparing the curable organopolysiloxane composition according to the present invention is not particularly limited and is carried out by homogeneously mixing each component. Organic solvents may be added as needed, and the composition may be prepared by mixing using a known stirrer or kneader. Since this composition has hydrosilylation reactivity upon heating, it is preferable to mix it at a temperature of less than 100°C, preferably less than 50°C.

[0067] [How to use as an adhesive] The curable organopolysiloxane composition according to the present invention contains component (A) above, and therefore possesses both heat-curing and photocuring properties by irradiation with high-energy rays. In particular, the semi-cured product obtained by heat curing functions as an adhesive layer with excellent initial tackiness. By irradiating it with high-energy rays, the tackiness of the adhesive layer to the substrate is greatly reduced, forming an easily peelable cured product that can be easily removed from the substrate. The method of use will be described below.

[0068] [Coating and heat curing] The curable organopolysiloxane composition according to the present invention forms a coating film when applied to a substrate, and when heated under temperature conditions of 80 to 200°C, preferably 90 to 150°C, a hydrosilylation reaction yields a semi-cured product that functions as an adhesive layer with excellent initial tackiness. The heating time required for curing can be appropriately selected depending on the thickness of the adhesive layer and the amount of catalyst used, but is generally in the range of 0.5 to 90 minutes. The adhesive layer obtained by heat curing using the composition according to the present invention contains unreacted silicon atom bonded functional groups (R A Because it contains ), it maintains further photocuring reactivity triggered by irradiation with high-energy rays.

[0069] Examples of coating methods include gravure coating, offset coating, offset gravure, roll coating, reverse roll coating, air knife coating, curtain coating, and comma coating. The coating amount can be designed to a desired thickness depending on the application, such as a display device. For example, the thickness of the adhesive layer after curing may be 1 to 1,000 μm, 5 to 900 μm, or 10 to 800 μm, but is not limited to these.

[0070] The semi-cured product before the photocuring reaction has sufficient initial tackiness. For example, when designing an adhesive layer with a thickness of 75 μm, the tackiness measured on a SUS plate using the 180° peel test method according to JIS Z 0237 at a tensile speed of 300 mm / min is 2.5 gf / inch or more, preferably 3.0 gf / inch or more. In particular, it is possible to design adhesive layers in the range of 3.0 to 50.0 gf / inch. It should be noted that the above thickness (75 μm) is the thickness of the cured layer itself, which serves as a standard for objectively defining the tackiness of the cured layer according to the present invention. It goes without saying that the curable organopolysiloxane composition of the present invention is not limited to a thickness of 75 μm, but can be used as a cured layer or adhesive layer of any thickness.

[0071] [Changes in adhesion due to irradiation with high-energy rays] The adhesive layer, which is a semi-cured product obtained by heat curing, undergoes further photocuring reaction triggered by irradiation with high-energy rays, resulting in a significant reduction in its adhesive strength, easy peelability, and formation of a hard cured product that does not leave adhesive residue on the substrate or the like, enabling easy peeling from the substrate. Specifically, when an organopolysiloxane semi-cured product obtained by a heat curing reaction is adhered to another substrate, the adhesive strength to that substrate decreases by 10% or more before and after the photocuring reaction accompanied by irradiation with high-energy rays, preferably by 30% or more, and particularly preferably by 50% or more. Such a change in adhesive strength can be quantitatively measured by the adhesive strength measurement test using the above-mentioned SUS plate or the like.

[0072] Examples of the high-energy rays (also referred to as active energy rays) used in the photocuring reaction include ultraviolet rays, electron beams, radiation, etc., but ultraviolet rays are preferred in terms of practicality. As the ultraviolet ray source, a high-pressure mercury lamp, a medium-pressure mercury lamp, a Xe-Hg lamp, a deep UV lamp, etc. are suitable. In particular, ultraviolet irradiation with a wavelength of 280 to 400 nm, preferably a wavelength of 300 to 400 nm, is preferred, and a light source having a plurality of emission bands may be used.

[0073] The irradiation amount of the high-energy rays can be appropriately designed. However, when the ultraviolet irradiation amount (illuminance) is 100 mJ / cm 2 ~10,000 mJ / cm 2 and more preferably 1,000 mJ / cm 2 ~5,000 mJ / cm 2 , a good change in the adhesive strength of the adhesive layer according to the present invention is realized triggered by the irradiation of the high-energy rays. Note that the irradiation of the high-energy rays may be performed with the substrate carrying the adhesive layer according to the present invention sandwiched therebetween as long as the substrate does not absorb electromagnetic waves in the above wavelength range. That is, as long as a certain amount of irradiation amount can be realized, the high-energy rays may be irradiated through a cover material such as a substrate or a protective film.

[0074] [Properties related to the transparency, color tone, or coloring / discoloration of the adhesive layer] The adhesive layer (including semi-cured and cured products) obtained by curing the curable organopolysiloxane composition and organopolysiloxane adhesive composition according to the present invention may be substantially transparent, translucent, or opaque, and its transparency can be designed according to the application of the adhesive layer. When it is transparent to the naked eye, more objectively, the transmittance of light at a wavelength of 450 nm of the adhesive layer, which consists of a cured layer with a thickness of 100 μm, is 80% or more, preferably 90% or more, and may be designed to be 95% or more, with the value of air being 100%. On the other hand, in adhesives such as temporary fixatives where light transmittance is not required, the adhesive layer may be translucent to opaque, and filler components or additives that impair light transmittance or colorability may be used depending on the required characteristics other than light transmittance.

[0075] [Method of use as an adhesive layer; adhesive sheet exhibiting changes in adhesive properties before and after high-energy ray irradiation] The adhesive layer according to the present invention may undergo surface treatments such as priming, corona treatment, etching, or plasma treatment on the surface of the adhesive layer or substrate to improve adhesion to the adherend. However, as described above, the adhesive layer of the present invention has excellent adhesion to substrates such as display devices, so these steps may be added as needed to further improve adhesion to the adherend, or higher production efficiency may be achieved by omitting these steps.

[0076] The curable organopolysiloxane composition according to the present invention can be partially cured by a condensation reaction by heating under the above temperature conditions after coating a release liner, and the release liner can be peeled off and bonded to a film-like substrate, tape-like substrate, or sheet-like substrate (hereinafter referred to as "film-like substrate"), or it can be cured by heating under the above temperature conditions after coating a film-like substrate, thereby forming an adhesive layer on the surface of the substrate. As described above, this adhesive layer has excellent initial adhesion and contains photocurable functional groups derived from component (A), so the adhesive strength decreases and the adhesive properties change to easily peelable when irradiated with high-energy rays.

[0077] Cured layers, particularly laminates comprising a film-like cured layer, are obtained by curing the organopolysiloxane composition according to the present invention on these film-like substrates. These layers may be used for adhesive tapes, removable protective films, bandages, low-temperature supports, transfer films, labels, emblems, and decorative or explanatory markings. Furthermore, cured layers, obtained by curing the organopolysiloxane composition according to the present invention, may be used in the assembly of automotive parts, toys, electronic circuits, or keyboards. Alternatively, cured layers, particularly film-like adhesive layers, obtained by curing the organopolysiloxane composition according to the present invention may be used for the protection, construction, and use of laminated touchscreens or flat panel displays.

[0078] Examples of substrate types include cardboard, corrugated cardboard, clay-coated paper, polyolefin laminated paper, particularly polyethylene laminated paper, synthetic resin films / sheets, natural fiber fabrics, synthetic fiber fabrics, artificial leather fabrics, and metal foils. Synthetic resin films / sheets are particularly preferred, and examples of synthetic resins include polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, cyclopolyolefin, and nylon. When heat resistance is particularly required, films made of heat-resistant synthetic resins such as polyimide, polyetheretherketone, polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamideimide, and polyethersulfone are suitable. On the other hand, for applications where visibility is required, such as display devices, transparent substrates, specifically transparent materials such as polypropylene, polystyrene, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and PEN, are suitable.

[0079] The above-mentioned substrate is preferably in the form of a film or sheet. Its thickness is not particularly limited and can be designed to any desired thickness depending on the application. Furthermore, to improve the adhesion between the support film and the cured adhesion layer, a support film that has been treated with a primer, corona, etching, or plasma may be used. In addition, the surface of the film-like substrate opposite to the cured layer / cured adhesion layer may be surface-treated with treatments such as scratch prevention, stain prevention, fingerprint prevention, anti-glare, anti-reflective, and anti-static properties.

[0080] The adhesive layer according to the present invention may be a single layer or a multilayer formed by laminating two or more adhesive layers, depending on the required characteristics. The multilayer adhesive layer may be formed by laminating films made one layer at a time, or by repeatedly applying a curable silicone composition to a film substrate equipped with a release layer and curing it.

[0081] The adhesive layer according to the present invention may serve not only for bonding or adhesion between components, but also as a functional layer selected from dielectric layers, conductive layers, heat dissipation layers, insulating layers, reinforcing layers, etc. In particular, the adhesive layer which is a semi-cured product obtained by heat curing a curable organopolysiloxane according to the present invention has excellent initial adhesion and contains photocurable functional groups derived from component (A). Therefore, when high-energy ray irradiation is triggered, the adhesive strength decreases and the adhesive properties change to easily peelable. Thus, after fixing or bonding with a desired apparatus or process, a cured adhesive layer is formed that can be removed very easily from the substrate surface by high-energy ray irradiation. Therefore, it is extremely useful for temporary functional layers or temporary fixing of functional layers intended for attachment and detachment.

[0082] In the case of an adhesive layer obtained by heat curing the curable organopolysiloxane composition of the present invention, particularly an adhesive sheet exhibiting changes in adhesive properties before and after high-energy ray irradiation, it is preferable to handle the adhesive layer as a laminate film that adheres to a film substrate equipped with a release layer having release coating ability in a peelable state. The release layer may also be called a release liner, separator, mold release layer, or release coating layer, and is preferably a release layer having release coating ability such as a silicone-based release agent, a fluorine-based release agent, an alkyd-based release agent, or a fluorosilicone-based release agent, or the substrate itself which forms fine physical irregularities on the substrate surface or which does not adhere well to the adhesion layer of the present invention. In particular, in the laminate according to the present invention, it is preferable to use a release layer obtained by curing a fluorosilicone-based release agent as the release layer.

[0083] The adhesive layer according to the present invention has the characteristic adhesive properties described above, and is capable of achieving transparency and low haze, making it useful as an elastic adhesion layer or temporary fixing layer for various electronic or electrical device components and as a protective film during semiconductor wafer processing. Similarly, it is also useful as an electronic material, a component for a display device, or a component for a transducer (including for sensors, speakers, actuators, and generators), and a preferred application of the cured product is as a component for electronic components or display devices. The cured product according to the present invention may be transparent or opaque, but a film-shaped cured product, especially a substantially transparent protective film, is suitable as a component for a display panel or display, and is particularly useful in so-called touch panel applications where a device, especially an electronic device, can be operated by touching the screen with a fingertip or the like. The cured product layer of the present invention may also be applied to film-like or sheet-like components used in sensors, speakers, actuators, etc., where transparency is not required and a certain degree of elasticity or flexibility of the adhesion layer itself is required.

[0084] [Use as adhesive tape] An article comprising a cured layer obtained by curing the curable silicone composition of the present invention may be an adhesive tape, particularly a protective tape intended for attachment and removal, and is characterized by comprising a sheet-like member made of the above-mentioned synthetic resin film / sheet, metal foil, woven fabric, nonwoven fabric, paper or other fibrous product, and the above-mentioned adhesive layer. The types of such adhesive tapes are not particularly limited and include insulating tape, heat-resistant tape, solder masking tape, mica tape binder, temporary fixing tape (particularly including temporary fixing tape for silicone rubber parts, etc.), and splicing tape (particularly including splicing tape for silicone release paper).

[0085] In particular, the cured product obtained by curing the curable silicone composition of the present invention, especially the cured layer, has excellent initial adhesion and contains photocurable functional groups derived from component (A). Therefore, when irradiated with high-energy rays, the adhesive strength decreases and the adhesive properties change to easily peelable. As a result, the adhesion properties and appearance of the adhesive layer are stable, and after use, it can be easily removed from the substrate surface by irradiation with light such as ultraviolet rays. Therefore, it is particularly suitable for use in functional films that are used temporarily on display devices, semiconductors, etc., with the expectation of attachment and detachment. In particular, it is extremely useful as a temporary fixing adhesive used in the manufacture of display devices such as CRT displays, liquid crystal displays, plasma displays, organic EL displays, inorganic EL displays, LED displays, surface electrolytic displays (SEDs), and field emission displays (FEDs), as well as touch panels that utilize these devices.

[0086] [Laminates and adhesive sheets] A laminate comprising a cured adhesive layer formed by curing the above-mentioned curable silicone composition may be formed on the above-mentioned film-like substrate, and preferably, these film-like substrates may be provided with a release layer for the cured adhesive layer.

[0087] In the aforementioned laminate, it is preferable that the sheet-like substrate has at least one release layer, and that the release layer is in contact with the cured adhesion layer. This allows the cured adhesion layer to be easily peeled off from the sheet-like substrate. The release agent included in the release layer is not particularly limited, and examples of release agents similar to those described above include.

[0088] In particular, the laminate may be handled by handling the adhesion layer separated from the film-like substrate on its own, and there may be two film-like substrates. in particular, Film-like substrate, A first release layer formed on the film-like substrate, An adhesive layer formed by coating the above-mentioned curable organopolysiloxane composition onto the release layer and heating and curing it, and A second release layer laminated on the adhesion layer. It may be equipped with these features.

[0089] Similarly, the laminate of the above form may be formed, for example, by coating the above-mentioned curable organopolysiloxane composition onto one release layer formed on a film-like substrate and curing it to form an adhesion layer, and then laminating another release layer on the adhesion layer.

[0090] Furthermore, the laminate of the above form may be manufactured, for example, by sandwiching the above-mentioned curable silicone composition between a first film-like substrate and a second film-like substrate, heating it, molding it to a certain thickness with a press or roll, and then curing the composition.

[0091] The first sheet substrate may have a first release layer, or the first sheet substrate itself may be release-compatible. Similarly, the second sheet substrate may have a second release layer, or the second sheet substrate itself may be release-compatible. If the first sheet substrate and / or the second sheet substrate have a first release layer and / or a second release layer, it is preferable that the cured adhesion layer is in contact with the first release layer and / or the second release layer.

[0092] Examples of sheet substrates with release properties include sheet substrates made of materials with release properties such as fluororesin films, or sheet substrates made of materials with little or no release properties, such as polyolefin films, to which release agents such as silicone or fluororesin are added. On the other hand, examples of sheet substrates with a release layer include polyolefin films coated with release agents such as silicone or fluororesin.

[0093] The aforementioned laminate can be used, for example, by applying a cured adhesion layer to a substrate and then peeling the adhesion layer off the film-like substrate.

[0094] The thickness of the adhesion layer (adhesive layer) obtained by heat curing the curable organopolysiloxane composition according to the present invention is preferably 5 to 10,000 μm, and more preferably 10 μm or more or 8,000 μm or less, and more preferably 20 μm or more or 5,000 μm.

[0095] [Components for display panels or displays] The adhesion layer (adhesive layer) obtained by heat curing the curable organopolysiloxane composition of the present invention can be used for the protection, construction, and use of laminated touchscreens or flat panel displays, and its specific use can be any known use of the adhesion layer (e.g., silicone PSA, silicone adhesive, and silicone sealant) without any particular limitations. [Industrial applicability]

[0096] The applications of the comodified organopolysiloxane, the curable organopolysiloxane composition containing the same, and the adhesive layer obtained by semi-curing / curing them according to the present invention are not limited to those disclosed above, and a film comprising a cured product obtained by curing the composition can be used in various display devices for displaying characters, symbols, and images. The surface shape of such a display device may be curved or curved rather than flat, and examples include various flat panel displays (FPDs), as well as curved displays or curved transparent screens used in automobiles (including electric vehicles) and aircraft. Furthermore, these display devices may be equipped with a touch panel function that allows input operations by touching icons, notification displays, or operation buttons on the screen or display for executing functions or programs. As devices, it can be applied to display devices such as CRT displays, liquid crystal displays, plasma displays, organic EL displays, inorganic EL displays, LED displays, surface electrolytic displays (SEDs), and field emission displays (FEDs), as well as touch panels utilizing these. Furthermore, the cured product obtained by curing the composition has excellent adhesion to the substrate and viscoelastic properties, and can therefore be used as a film or sheet-like member that is a transducer component (including those for sensors, speakers, actuators, and generators), such as a membrane for a speaker. In addition, it can be used as a sealing layer or adhesion layer for secondary batteries, fuel cells, or solar cell modules. [Examples]

[0097] The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to the following examples. Furthermore, due to the properties of the semi-cured product according to the present invention, irradiation with high-energy rays is not performed simultaneously during heat curing. (Measurement of molecular weight of organopolysiloxane components) Using Waters gel permeation chromatography (GPC) with tetrahydrofuran (THF) as the solvent, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of organopolysiloxane components such as organopolysiloxane resins were determined in terms of standard polystyrene equivalent.

[0098] (Synthesis Example 1) The following formula: [ka] A solution of 100.0 g of alkenyl-modified polysiloxane represented by [formula] was diluted with 35.0 g of toluene and mixed with 10.5 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.0500 g of 4-methoxyphenol. To this, 0.0500 g of a toluene solution of platinum / 1,3-divinyltetramethyldisiloxane complex (1.0 × 10¹⁶ as elemental platinum) was added. -4 (containing g) was added, and the mixture was stirred for 4 hours while adjusting the temperature so that the temperature of the mixture was between 25°C and 45°C. In this case, the ratio of the number of SiH groups to the number of hexenyl groups is 0.88. The disappearance of the SiH groups was confirmed by IR spectroscopy, and the molar ratio of methacrylate groups to hexenyl groups was 4.7, as shown in the following formula: [ka] A toluene solution of the linear organopolysiloxane (A-1) represented by [formula] was obtained. The molar ratio of methacrylate groups to hexenyl groups was determined by 13C NMR.

[0099] (Synthesis Example 2) The above synthesis example (1) and the experimental procedure, as well as the amounts of the side-chain hexenyl group-modified polysiloxane, platinum catalyst, polymerization inhibitor, and solvent used as raw materials, were the same. By using 6.7 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate, 141.7 g of a toluene solution of linear organopolysiloxane (A-2) with a molar ratio of methacrylate groups to hexenyl groups of 4.2 was obtained.

[0100] (Synthesis Example 3) The following formula: [ka] (In the formula, Vi represents a CH=CH² group.) A solution of 100.0 g of a side-chain vinyl-substituted polysiloxane represented by [formula] was diluted with 35.0 g of toluene and mixed with 7.1 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.1000 g of 4-methoxyphenol. To this, 0.1000 g of a toluene solution of platinum / 1,3-divinyltetramethyldisiloxane complex (2.0 × 10¹⁶ as elemental platinum) was added. -4 (containing g) was added, and the mixture was stirred for 4 hours while adjusting the temperature so that the temperature of the mixture was 40°C to 50°C. In this case, the ratio of the number of SiH groups to the vinyl groups bonded to the silicon atoms is 0.80. The disappearance of the SiH groups was confirmed by IR spectroscopy, and the molar ratio of methacrylate groups to vinyl groups was 3.5, as shown in the following formula: [ka] 142.1 g of a toluene solution of the linear organopolysiloxane (A-3) represented by [formula] was obtained. The molar ratio of methacrylate groups to vinyl groups was determined by 13C NMR.

[0101] (Synthesis Example 4) The experimental procedure and the amounts of the side-chain vinyl group-modified polysiloxane, platinum catalyst, polymerization inhibitor, and solvent used as raw materials were the same as in the above synthesis example (3). By using 1.6 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate, 136.6 g of a toluene solution of linear organopolysiloxane (A-4) with a molar ratio of methacrylate groups to vinyl groups of 0.2 was obtained.

[0102] (Synthesis Example 5) R3SiO 1 / 2 Siloxane units (M units) represented by (wherein the formula R independently represents a methyl group or a vinyl group), and SiO 4 / 2A xylene solution of 25.0 g containing 18.8 g of an organopolysiloxane resin containing siloxane units (Q units) represented by was mixed with 0.48 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.0290 g of 4-methoxyphenol. To this was added 0.0240 g of a toluene solution of a platinum / 1,3-divinyltetramethyldisiloxane complex (containing 4.8×10 -5 g of platinum as a simple substance), and the mixture was stirred for 4 hours while adjusting the temperature so that the temperature of the mixture was 40°C to 50°C. In this case, the ratio of the number of methacrylate groups to the vinyl groups contained in the organopolysiloxane resin is 0.1. By IR spectroscopic measurement, the disappearance of the SiH group was confirmed, and in the molecule, R3SiO 1 / 2 (wherein R independently represents a methyl group or a vinyl group) and an organopolysiloxane resin (E-3) containing siloxane units (Q units) represented by SiO 4 / 2 was obtained as a 25.5 g xylene solution.

[0103] · Component (A-1): Linear organopolysiloxane shown in Synthesis Example (1) (vinyl group content: 0.20% by mass, methacrylate group content: 2.94% by mass) · Component (A-2): Linear organopolysiloxane shown in Synthesis Example (2) (vinyl group content: 0.15% by mass, methacrylate group content: 1.97% by mass) · Component (A-3): Linear organopolysiloxane shown in Synthesis Example (4) (vinyl group content: 0.19% by mass, methacrylate group content: 2.12% by mass) · Component (A-4): Linear organopolysiloxane shown in Synthesis Example (5) (vinyl group content: 0.77% by mass, methacrylate group content: 0.43% by mass) · Component (A-5): A raw rubber of a dimethylsiloxy·(5-hexenyl)methylsiloxane copolymer blocked at both ends with trimethylsiloxy groups with a plasticity of 110 (vinyl group content: 0.57% by mass) · Component (A-6): A dimethylsiloxy·(5-hexenyl)methylsiloxane copolymer blocked at both ends with trimethylsiloxy groups (vinyl group content: 0.57% by mass) • Ingredients (A-7): Dimethylsiloxane-methylvinylsiloxane copolymer with ligated trimethylsiloxy groups at both ends (vinyl group content: 0.91% by mass) • Component (B): Trimethylsiloxy group closure at both ends, dimethylsiloxane / methylhydrogensiloxane copolymer (vinyl group content: 0.75% by mass) • Component (C): Solution of platinum-1,3-divinyl 1,1,3,3-tetramethyldisiloxane complex with vinyldimethylsiloxy groups sealed at both ends (approximately 0.7% by mass in platinum concentration) • Ingredient (D): 2,2-Dimethoxy-2-phenylacetophenone (CAS#: 24650-42-8, manufactured by Tokyo Chemical Industry Co., Ltd.) • Component (E-1): Contains R3SiO in the molecule 1 / 2 Siloxane units (M units) represented by (wherein the formula R independently represents a methyl group or a vinyl group), and SiO 4 / 2 Organopolysiloxane resin containing siloxane units (Q units) represented by (weight-average molecular weight (Mw) of 4000 as measured by GPC using toluene as a solvent) • Component (E-2): Contains R3SiO in the molecule 1 / 2 Siloxane units (M units) represented by (wherein the formula R independently represents a methyl group or a vinyl group), and SiO 4 / 2 Organopolysiloxane resin containing siloxane units (Q units) represented by (weight-average molecular weight (Mw) of 7000 as measured by GPC using toluene as a solvent) • Component (E-3): R3SiO in the molecule described in Synthesis Example 5 1 / 2 Siloxane units (M units) represented by (wherein the formula R independently represents a methyl group or a vinyl group), and SiO 4 / 2 Organopolysiloxane resin containing siloxane units (Q units) represented by (weight-average molecular weight (Mw) of 7500 as measured by GPC using toluene as a solvent) • Component (E-4): Organopolysiloxane resin as shown in synthesis example (6) (vinyl group content: 0.77% by mass, methacrylate group content: 0.43% by mass) ·Component (F-1): ViMe2SiO (Me2SiO)300 SiViMe2 Dimethylpolysiloxane with dimethylvinylsiloxy groups sealed at both ends of the molecular chain (vinyl group content = 0.24% by mass), represented as [formula]. • Ingredients (F-2): Dimethylpolysiloxane raw rubber with dimethylvinylsiloxy groups sealed at both ends of the molecular chain, with a plasticity of 60 (vinyl group content = 0.01% by mass)

[0104] (Examples 1-12, Comparative Examples 1-3) Examples and comparative examples of the present invention are described below. In each example and comparative example, "cured" means that each composition has been completely cured or partially cured according to the respective curing conditions.

[0105] (Preparation of a curing-reactive silicone composition) Using the components shown in Table 1, adhesive compositions consisting of organopolysiloxane compositions with curing reactivity as shown in each example and comparative example were prepared. Note that all percentages in Table 1 are mass percentages.

[0106] (Adhesion strength measurement before and after UV irradiation) Each composition was coated onto a PET film (Toray Industries, Inc., product name Lumirror® S10, thickness 50 μm) to a cured thickness of 75 μm, and cured at 100°C for 3 minutes. After standing for 30 minutes, the sample was cut into 25 mm wide strips, and the adhesive layer side was attached to a SUS plate (Paltec) using a roller to create a test specimen. The adhesive strength measured on the SUS plate using the 180° peel test method according to JIS Z 0237 at a tensile speed of 300 mm / min is shown in Table 1 as the "initial adhesive strength". In addition, the same test specimen was subjected to UV-LED ultraviolet irradiation using a device (JATEC) from the PET side, with an integrated ultraviolet irradiation dose (illuminance) of 2,000 mJ / cm². 2 The test specimens were irradiated with ultraviolet light at a wavelength of 365 nm to achieve the desired result, and the adhesive strength of the specimens after UV irradiation was measured in the same manner as described above. The results are shown in Table 1 as "Adhesive strength after UV irradiation." If the adhesive layer became cloudy and lost visibility due to UV light irradiation, it was evaluated as ×.

[0107] [Table 1] *1) Initial adhesive strength (gf / inch) to SUS plate *2) Adhesion strength (gf / inch) of SUS plate after UV irradiation

[0108] As shown in Table 1, the heat-cured products of the compositions containing the comodified organopolysiloxane of the present invention according to Examples 1 to 12 exhibited an initial adhesive strength within a practically sufficient range, and the adhesive strength could be adjusted to a certain extent through compositional design. Furthermore, upon UV irradiation, the adhesive layer's adhesive strength significantly decreased, its adhesive properties changed to easily peelable, and its transparency was maintained. For this reason, it is expected to be highly useful as a protective film, temporary fixing film, etc., when used in the manufacturing process of semiconductor wafers, display devices, and electronic devices. On the other hand, when organopolysiloxanes containing only vinyl groups were used, as in Comparative Examples 1 to 3, only slight adhesive properties could be achieved, and transparency (visibility) was lost upon UV irradiation. From this, it was difficult to achieve initial adhesive strength, easy peelability after use, and the maintenance of transparency unless the comodified organopolysiloxane of the present invention was used.

Claims

1. The molecule contains a silicon atom bond functional group (R) represented by the following general formula (1-1). Ａ ), and a silicon atom bond functional group (R) containing at least one aliphatic unsaturated carbon-carbon bond Ｖｉ ) (However, the above R Ａ A chain-like, covariant organopolysiloxane containing (excluding the functional group that is...). General formula (1-1): 【Chemistry 1】 [wherein, R １ independently represents a hydrogen atom, a methyl group, or a phenyl group, and R ２ independently represents an alkyl group or an aryl group. Z １ represents -O(CH ２ ) ｍ -(m is a number in the range of 0 to 3). Z ２ is a divalent organic group represented by -(CH ２ ) ｎ -(n is a number in the range of 3 to 10) bonded to a silicon atom constituting the main chain of the polysiloxane which is *. ]

2. The above functional group R Ｖｉ The comodified organopolysiloxane according to claim 1, wherein the group is an alkenyl group having 2 to 20 carbon atoms.

3. The above functional group R Ｖｉ The comodified organopolysiloxane according to claim 1 or claim 2, wherein the group is a hexenyl group.

4. Within the molecule, the above functional group R Ｖｉ A comodified organopolysiloxane according to any one of claims 1 to 3, comprising two or more of the above.

5. The molecule contains at least one aliphatic unsaturated carbon-carbon bond in the silicon atom bond functional group (R Ｖｉ ) (However, the above R Ａ (excluding the functional group that is) per mole, the silicon atom bonded functional group (R Ａ A comodified organopolysiloxane according to any one of claims 1 to 4, comprising ) in a range where its average amount of substance is 2.0 to 50.0 moles.

6. In the molecule, the silicon atom bonding functional group (R Ａ The comodified organopolysiloxane according to any one of claims 1 to 5, wherein the content of ) is in the range of 0.10 to 10.0 mol% with respect to all functional groups bonded to silicon atoms constituting the polysiloxane molecule.

7. A comodified organopolysiloxane according to any one of claims 1 to 6, wherein the main chain of the polysiloxane is linear.

8. (A) 100 parts by mass of the comodified organopolysiloxane according to any one of claims 1 to 7 (B) 0.1 to 5 parts by mass of an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in the molecule. (C) Hydrosilylation reaction catalyst: The amount of platinum-based metal in the catalyst is 0.01 to 1000 ppm, and (D) Photoradical polymerization initiator 0.1 to 20 parts by mass A curable organopolysiloxane composition containing the following:

9. Furthermore, (E) contains R ３ SiO １／２ Siloxane units (M units) represented by (wherein R independently represents a monovalent organic group), and SiO ４／２ 0 to 150 parts by mass of organopolysiloxane resin containing siloxane units (Q units) represented by the formula, with a ratio of M units to Q units in the range of 0.5 to 2.

0. A curable organopolysiloxane composition according to claim 8, comprising the above.

10. Furthermore, the curable organopolysiloxane composition according to claim 8 or claim 9, further comprising (G) an organic solvent.

11. A curable organopolysiloxane composition according to any one of claims 8 to 10, characterized by having both heat-curable properties and photocurable properties by irradiation with ultraviolet light of a wavelength of 280 to 400 nm.

12. An organopolysiloxane adhesive composition comprising a comodified organopolysiloxane according to any one of claims 1 to 7.

13. An organopolysiloxane adhesive layer obtained by curing a curable organopolysiloxane composition according to any one of claims 8 to 11.

14. Step (I): A step of applying the organopolysiloxane adhesive composition according to claim 11 onto a substrate. Step (II): A step in which the organopolysiloxane adhesive composition applied in Step (I) is partially cured by a heat curing reaction. Step (III): A step in which the semi-cured product obtained in Step (II) is irradiated with ultraviolet light with a wavelength of 280-400 nm to further cure it through a photocuring reaction. A method for using an organopolysiloxane adhesive composition, characterized in that the adhesive strength of the semi-cured product obtained in step (II) to other substrates decreases due to irradiation with high-energy rays in step (III).

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