Pressure-sensitive adhesive layer-forming organopolysiloxane composition and use thereof

Abstract

[Problem] Provided are: a curing-reactive organopolysiloxane composition in which viscoelastic properties such as storage elastic modulus (G') can be designed in a wide range, and which has excellent curing properties and can form a pressure-sensitive adhesive layer having sufficient adhesive strength and tensile adhesive strength for practical use; and a use thereof. [Solution] This pressure-sensitive adhesive layer-forming organopolysiloxane composition comprises (A) an organopolysiloxane having an alkenyl group, (B) an organopolysiloxane resin or a resin mixture in which the content of a hydroxyl group and the like with respect to all silicon atoms in a molecule is at most 9 mol%, (C) an organohydrogen polysiloxane, (D) an organosilicon compound having an alkenyl group, and (E) a hydrosilylation reaction catalyst, wherein the ratio (molar ratio) of the amount of substance of a SiH group in the component (C) with respect to the total amount of alkenyl groups in the components (A), (B) and (D) is at least 1.0.

Description

[Technical field]

[0001] The present invention relates to a curable reactive organopolysiloxane composition for forming a pressure-sensitive adhesive layer and its use. [Background technology]

[0002] Compared with acrylic or rubber-based pressure-sensitive adhesive compositions, polysiloxane-based pressure-sensitive adhesive compositions are excellent in electrical insulation, heat resistance, cold resistance, adhesion to various adherends, and transparency as required, and therefore, addition reaction curing type pressure-sensitive adhesive compositions in particular are widely used. In recent years, applications to advanced electronic materials such as smart devices, display element fields, speakers, etc. have been considered, and polysiloxane-based pressure-sensitive adhesives with excellent heat and cold resistance are expected to be effective in protecting electrode layers and display layers and improving adhesion between layers.

[0003] In particular, in recent material development, there is a demand for polysiloxane-based pressure-sensitive adhesive compositions that have a high degree of freedom in designing the storage modulus (e.g., the shear storage modulus G') over a wide temperature range including room temperature, that have excellent curing properties, and that have adhesive strength sufficient for practical use. However, the pressure-sensitive adhesive compositions described in publicly known literature do not fully satisfy these properties, and there is still room for improvement.

[0004] For example, Patent Document 1 discloses an adhesive rubber sheet, but the ratio of the resin component and the siloxane polymer component is such that the resin component content is low, and there is no mention or suggestion of the use of a combination of a resin component with specific properties such as molecular weight, hydroxyl group content, etc. Furthermore, the adhesive rubber sheet uses finely powdered silica, etc., and does not satisfy the storage modulus (G') targeted by the present invention.

[0005] Similarly, Patent Document 2 discloses a silicone pressure-sensitive adhesive that uses an organopolysiloxane resin with a number average molecular weight of 950 to 1600, but does not mention or suggest the use of a combination of resin components that differ in molecular weight and have specific properties such as the content of hydroxyl groups. Furthermore, although the silicone pressure-sensitive adhesive has a certain level of adhesive strength, it does not satisfy the storage modulus (G') that is the objective of the present invention.

[0006] On the other hand, Patent Document 3 proposes a laminate having a transparent resin adhesive layer characterized by a ratio of the amount of substance of the resin component to the polymer component in the range of 0.5 to 1.0 and a small difference in storage modulus G' between low temperature and room temperature. However, only condensation-reactive transparent resin adhesive layers are specifically disclosed, and there is a problem that the curing reaction is too slow for industrial use. Furthermore, the transparent resin adhesive layer does not satisfy the storage modulus (G') and adhesive strength sufficient for practical use that are the objectives of the present invention.

[0007] Here, the present applicants have proposed a curable silicone composition capable of forming a cured layer having a sufficient elastic modulus and loss factor (tan δ) for flexible laminate applications in Patent Document 4. However, the compositions specifically disclosed in the examples and the like disclose a combination of resin components with different weight average molecular weights in some parts, but do not fully solve the problems of the present invention.

[0008] Although these prior art documents describe the use of an adhesion promoter as an optional component, they make no mention or suggestion of the use of an adhesion promoter, which is an organosilicon compound having a specific functional group, in a specific quantitative range in relation to a crosslinking agent, or of the technical effects that result from this. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2006-225420 A [Patent Document 2] Japanese Patent Application Publication No. 05-214316 [Patent Document 3] International Patent Publication No. 2017-082654 [Patent Document 4] International Patent Publication No. 2017-188308 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made to solve the above problems, and aims to provide a curing-reactive organopolysiloxane composition that has a high degree of freedom in designing the storage modulus (G'), has excellent curing properties, and forms a pressure-sensitive adhesive layer having practically sufficient adhesive strength and tensile adhesive strength. Another aim of the present invention is to provide the use of the curing-reactive organopolysiloxane composition or its cured product as a pressure-sensitive adhesive layer, as an elastic adhesive member in a wide range of applications, and to provide an apparatus or device equipped with them. [Means for solving the problem]

[0011] The present inventors have intensively studied the above-mentioned problems, and have arrived at the present invention. That is, one of the objects of the present invention is achieved by using an organopolysiloxane resin in which the sum of the content of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol% or less in a hydrosilylation reaction-curable pressure-sensitive adhesive layer-forming organopolysiloxane composition, and by using in combination an organosilicon compound that contains an alkenyl group in the molecule and has the property of being usable as an adhesion promoter (these are components that do not correspond to the alkenyl group-containing dialkylpolysiloxanes or alkenyl group-containing organopolysiloxane resins used as the main agent of ordinary silicone pressure-sensitive adhesives). In addition, the above-mentioned problems can be achieved by using the curing-reactive organopolysiloxane composition or its cured product as a pressure-sensitive adhesive layer, as an electronic material or a member for a display device, and by using electronic components, displays, and speakers equipped with them. Effect of the Invention

[0012] The pressure-sensitive adhesive layer-forming organopolysiloxane composition of the present invention has excellent curing properties by hydrosilylation reaction, and when cured, it can form a pressure-sensitive adhesive layer having practically sufficient adhesive strength, particularly excellent tensile adhesive strength, high degree of freedom in designing the storage modulus (G'), and practically sufficient adhesiveness. Furthermore, the curing reactive organopolysiloxane composition or its cured product can be suitably used as a pressure-sensitive adhesive layer, electronic material, or display device member, and an electric / electronic component or display device equipped with them can form a pressure-sensitive adhesive layer that satisfies the above-mentioned required properties and is free from problems of poor curing and has sufficient viscoelasticity of the adhesive layer in a wide temperature range including low temperatures, so that it is easy to industrialize and has the advantage that the performance of the laminates such as display devices and speakers obtained can be improved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Pressure-sensitive adhesive layer-forming organopolysiloxane composition] First, the pressure-sensitive adhesive layer-forming organopolysiloxane composition of the present invention will be described. The composition cures quickly by a curing reaction including a hydrosilylation reaction, and has a high degree of freedom in designing the storage modulus (G'). The shear storage modulus G' at room temperature can be designed in a wide range of 0.005 MPa or more, and the pressure-sensitive adhesive layer is formed that has excellent tensile adhesive strength in addition to sufficient adhesive strength for practical use. Each of the components and their quantitative ranges, as well as the properties of the pressure-sensitive adhesive layer, will be described below.

[0014] As described above, the organopolysiloxane composition of the present invention cures via a hydrosilylation reaction to form a pressure-sensitive adhesive layer having a certain level of adhesive strength, and is characterized in that the composition uses an organopolysiloxane resin in which the sum of the content of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol % or less, and uses in combination with an organosilicon compound having at least one alkenyl group in the molecule that does not correspond to the main component, a linear or cyclic organopolysiloxane having an alkenyl group, and an organopolysiloxane resin, and is designed so that the SiH / Vi ratio in the composition is 1.0 or greater.

[0015] Typically, hydrosilylation reaction-curing silicone-based pressure-sensitive adhesives use a linear or cyclic polydialkylsiloxane having an alkenyl group in the molecule as the base component and an organopolysiloxane resin as the adhesion-imparting component to achieve pressure-sensitive adhesive and tackiness properties in the cured product. In the present invention, however, by using a specific amount of an organosilicon compound having an alkenyl group that does not fall under these base components or adhesion-imparting components, the curing properties of the composition are improved, and the shear storage modulus G', stress at 500% strain, and adhesive strength of the resulting pressure-sensitive adhesive layer can be designed with an extremely high degree of freedom within a practical range, and the tensile strength, etc. of the resulting pressure-sensitive adhesive layer can be further improved.

[0016] Specifically, the organopolysiloxane composition of the present invention comprises: (A) a linear or cyclic organopolysiloxane having an average of more than one alkenyl group in the molecule; (B) an organopolysiloxane resin in which the sum of the contents of hydroxyl groups and hydrolyzable groups relative to all silicon atoms in the molecule is 9 mol % or less; (C) an organohydrogenpolysiloxane having at least two Si-H bonds in the molecule; (D) an organosilicon compound having an average of more than one alkenyl group per molecule (excluding components corresponding to components (A) and (B)); (E) an effective amount of a hydrosilylation reaction catalyst, and Optionally, (A') a linear organopolysiloxane that does not contain a carbon-carbon double bond-containing reactive group in the molecule. and the amount of component (C) is such that the ratio (molar ratio) of the amount of substance of SiH groups in component (C) to the sum of the amounts of substances of alkenyl groups in components (A), (B) and (D) is 1.0 or more. Since the composition contains a hydrosilylation reaction catalyst, it may further contain a cure retarder (F) from the viewpoint of handling and workability, and may contain other additives within the scope of the present invention. Each component will be described below.

[0017] The alkenyl-containing organopolysiloxane of component (A) is a linear or cyclic polysiloxane molecule, which is the main component (base polymer) of this composition, and contains an average of more than one alkenyl group bonded to a silicon atom per molecule, with the preferred number of alkenyl groups being 1.5 or more per molecule. Examples of the alkenyl group of the organopolysiloxane of component (A) include alkenyl groups having 2 to 10 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl groups, with vinyl or hexenyl being particularly preferred. Examples of the bonding position of the alkenyl group of component (A) include the molecular chain terminal and / or molecular chain side chain. Note that component (A) may contain only a single component, or may be a mixture of two or more different components.

[0018] In the organopolysiloxane of component (A), examples of organic groups bonded to silicon atoms other than alkenyl groups include alkyl groups such as methyl groups; aralkyl groups; and halogenated alkyl groups, with methyl groups and phenyl groups being particularly preferred.

[0019] Component (A) has a linear or cyclic polysiloxane molecular structure, unlike component (B). For example, component (A) is preferably linear, partially branched linear (branched), or cyclic, and may be partially cyclic or three-dimensionally networked. Preferably, the main chain is a linear or branched diorganopolysiloxane having a repeating diorganosiloxane unit and both ends of the molecular chain are blocked with triorganosiloxy groups. Polydialkylsiloxanes having alkenyl groups in the molecule, polydialkylsiloxane-arylalkylsiloxane copolymers, etc., are industrially common forms. The siloxane units that give branched organopolysiloxanes are T units or Q units, which will be described later.

[0020] The properties of component (A) at room temperature may be oil-like or rubber-like, and it is preferable that component (A) has a viscosity of 50 mPa·s or more, and particularly 100 mPa·s or more, at 25° C. In particular, when the organopolysiloxane composition according to the present invention is a solvent-based composition, it is preferable that at least a portion of component (A) is (A1) a rubber-like alkenyl-group-containing organopolysiloxane having a viscosity of 100,000 mPa·s or more at 25° C. or a plasticity measured in accordance with the method specified in JIS K6249 (a 4.2 g spherical sample is subjected to a load of 1 kgf for 3 minutes at 25° C., the thickness is read to the nearest 1 / 100 mm, and this value is multiplied by 100) in the range of 50 to 200, and more preferably in the range of 80 to 180.

[0021] From the viewpoint of preventing contact failure, it is preferable that these alkenyl group-containing organopolysiloxanes have reduced or removed volatile or low molecular weight siloxane oligomers (octamethyltetrasiloxane (D4), decamethylpentasiloxane (D5), etc.) The extent of this can be designed as desired, but it may be less than 1 mass% of the entire component (A), less than 0.1 mass% for each siloxane oligomer, or may be reduced to near the detection limit as necessary.

[0022] The content of the alkenyl group in the (A1) component is not particularly limited, but from the viewpoint of the technical effect of the present invention, the content of the vinyl (CH2=CH) moiety in the alkenyl group in the (A1) component (hereinafter referred to as the "vinyl content") is preferably in the range of 0.005 to 0.400 mass%, and more preferably in the range of 0.005 to 0.300 mass%. In addition, from the viewpoint of increasing the elastic modulus and tensile stress of the obtained pressure-sensitive adhesive layer, the vinyl content is more preferably in the range of 0.03 to 0.40 mass%, and more preferably in the range of 0.04 to 0.40 mass%. Note that the (A) component may be a mixture of two types of alkenyl-containing organopolysiloxanes having different vinyl contents, and the average value of the vinyl content is preferably in the above range.

[0023] As the component (A) of the present invention, it is possible to use a component (A) having a lower viscosity than the aforementioned component (A1), specifically, (A2) an alkenyl group-containing organopolysiloxane having a viscosity of less than 100,000 mPa s at 25° C. Here, examples of the components (A2) other than the viscosity are the same as those of the component (A1).

[0024] From the viewpoint of the technical effects of the present invention, it is preferable that 50% by mass or more of the component (A) is the high polymerization degree alkenyl-containing organopolysiloxane (A1), and it is particularly preferable that 75 to 100% by mass is the component (A1). That is, when the component (A1) (= high polymerization degree alkenyl-containing organopolysiloxane) and the component (A2) (= lower polymerization degree alkenyl-containing organopolysiloxane) are used in combination as the component (A) of the present invention, the mass ratio of the two is in the range of 50:50 to 100:0, more preferably 75:25 to 100:0 or 75:25 to 90:10.

[0025] As described above, component (A) may be a cyclic alkenyl group-containing organopolysiloxane, specifically, cyclic siloxanes having an alkenyl group, such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane. From the viewpoint of the technical effects of the present invention, it is preferable that component (A) contains a chain-like alkenyl group-containing organopolysiloxane, but cyclic alkenyl group-containing organopolysiloxanes may function as a reactive diluent or curing reactivity regulator in addition to functioning as a base agent, and are preferably used appropriately depending on the needs of the viscosity, production method, curing characteristics, etc. of the composition to be designed.

[0026] The organopolysiloxane resin (B) is one of the characteristic components of the present invention, and is a tackifier that imparts adhesion to a substrate, and at the same time, is a component that realizes a storage modulus and a practical range of adhesion. More specifically, the (B) component is an organopolysiloxane resin or a mixture thereof with a reduced content of hydroxyl groups or hydrolyzable groups, and is unlikely to undergo hydrolysis / polymerization reactions between the (B) components, and by using a combination of resins with different average molecular weights, a predetermined storage modulus and a practical range of adhesion in the pressure-sensitive adhesive layer, which is the cured product, is realized.

[0027] In detail, the sum of the contents of hydroxyl groups and hydrolyzable groups in the molecule of component (B) is in the range of 9 mol% or less based on the total silicon atoms in the organopolysiloxane resin molecule, and is preferably 7 mol% or less based on the total silicon atoms in the molecule. The contents of hydroxyl groups and hydrolyzable groups in component (B) can also be expressed by converting all of these functional groups into hydroxyl groups. In this case, if the mass% is calculated assuming that all hydrolyzable groups other than hydroxyl groups in the organopolysiloxane resin molecule are hydroxyl groups (OH), the sum of the contents of the above hydroxyl groups and hydrolyzable groups can also be expressed as 2.0 mass% or less, and preferably 1.6 mass% or less, of the contents of hydroxyl groups and hydrolyzable groups converted into hydroxyl groups in the organopolysiloxane resin molecule. Hydroxyl groups or hydrolyzable groups are directly bonded to silicon in T units or Q units of the siloxane units in the resin structure described below, and are groups derived from the raw silane or generated as a result of hydrolysis of the silane. Therefore, the content of hydroxyl groups or hydrolyzable groups can be reduced by hydrolyzing the synthesized organopolysiloxane resin with a silylating agent such as trimethylsilane.

[0028] In the (B) component, if the amount of the hydroxyl group or hydrolyzable group exceeds the upper limit, the condensation reaction between the organopolysiloxane resin molecules proceeds, and an organopolysiloxane resin structure with a large molecular weight is likely to be formed in the cured product. Such an organopolysiloxane resin with a large molecular weight tends to impair the curability of the entire composition, and the curability of the composition at low temperatures may become insufficient, or the resulting pressure-sensitive adhesive layer may not have a storage modulus sufficient for practical use. Furthermore, if there is a large amount of unreacted hydroxyl group or hydrolyzable group in the (B) component, it may cause poor curing by inhibiting the hydrosilylation reaction, or the temperature condition required for the curing reaction to proceed may become high, which may be undesirable from the viewpoint of industrial production.

[0029] Component (B) is an organopolysiloxane resin or a mixture thereof, which is an organopolysiloxane having a three-dimensional structure. For example, R2SiO 2 / 2 Units (D units) and RSiO 3 / 2 units (T units) (wherein R each independently represent a monovalent organic group) and the content of hydroxyl groups or hydrolyzable groups is within the above range, a resin consisting of only T units and the content of hydroxyl groups or hydrolyzable groups is within the above range, and RSiO 1 / 2 Units (M units) and SiO 4 / 2 In particular, RSiO 1 / 2 Units (M units) and SiO 4 / 2 It is preferable to use a resin (also called MQ resin) that is composed of units (Q units) and in which the sum of the contents of hydroxyl groups and hydrolyzable groups relative to all silicon atoms in the molecule is in the range of 0 to 7 mol % (preferably 0.0 to 1.6 mass % when all of these functional groups are converted into hydroxyl groups).

[0030] The monovalent organic group of R is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, and examples thereof include an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 6 to 10 carbon atoms, a benzyl group, a phenylethyl group, and a phenylpropyl group. In particular, it is preferable that 90 mol % or more of R are alkyl groups having 1 to 6 carbon atoms or phenyl groups, and it is particularly preferable that 95 to 100 mol % of R are methyl groups or phenyl groups.

[0031] Component (B) is RSiO 1 / 2 Units (M units) and SiO 4 / 2In the case of a resin consisting of units (Q units), 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 adhesive strength to the substrate may decrease, and if it is more than 2.0, the cohesive strength of the substance constituting the adhesive layer decreases. In addition, it is also possible to contain D units and T units in component (B) within a range that does not impair the characteristics of the present invention. Furthermore, from the viewpoint of preventing contact failure, etc., these organopolysiloxane resins may have reduced or removed low molecular weight siloxane oligomers.

[0032] Preferably, the component (B) in the present invention is an organopolysiloxane resin mixture containing the following components (b1) and (b2) in a mass ratio of 1:99 to 99:1. (b1) An organopolysiloxane resin in which the sum of the content of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol % or less and the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) relative to standard polystyrene is 4,500 or more; (b2) An organopolysiloxane resin in which the sum of the content of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol % or less, and the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) relative to standard polystyrene is less than 4,500.

[0033] The organopolysiloxane resins of components (b1) and (b2) differ from each other in their weight average molecular weight (Mw), which is the average molecular weight that takes into account the proportion of each molecule in the whole of each organopolysiloxane resin, as measured by gel permeation chromatography (GPC) using standard polystyrene as the conversion factor.

[0034] The component (b1) is an organopolysiloxane resin having a high molecular weight, and its weight average molecular weight (Mw) is 4500 or more, preferably 5000 or more, and particularly preferably 5500 or more. In practice, the component (b1) is the above-mentioned R3SiO 1 / 2 Units (M units) and SiO 4 / 2 Resins made of units (Q units) are particularly suitable.

[0035] Component (b2) is a low molecular weight organopolysiloxane resin, the weight average molecular weight (Mw) of which is less than 4500, preferably 4000 or less, and particularly preferably 3750 or less. In practice, component (b1) is the above-mentioned R3SiO 1 / 2 Units (M units) and SiO 4 / 2 Resins made of units (Q units) are particularly suitable.

[0036] When component (B) is an organopolysiloxane resin mixture containing the above components (b1) and (b2) in a mass ratio of 1:99 to 99:1, the mixing ratio is not particularly limited, but may be in the range of 5:95 to 95:5, 10:90 to 90:10, or 15:85 to 85:15, depending on the composition and viscoelasticity design.

[0037] [Mass ratio of component (B) to components (A) and (A')] In the pressure-sensitive adhesive layer-forming organopolysiloxane composition according to the present invention, the mass ratio of the organopolysiloxane resin (B) component to the linear or cyclic reactive siloxane component (A) and the later-described component (A') is preferably in the range of 0.9 to 3.0. In particular, when the above-described characteristic organopolysiloxane resin mixture is selected as the component (B) and the above-described resin component is blended with the linear siloxane polymer component so as to fall within the above-described range, the properties such as curability, adhesive strength, and storage modulus that are the objective of the present invention are preferably realized. In particular, the mass ratio of the component (B) to the component (A) and the later-described component (A') may be in the range of 1.1 to 3.0, and may be 1.4 or more, 1.5 or more, or 2.0 or more in order to realize the desired adhesive strength and storage modulus, with the range of 1.4 to 3.0 being particularly preferred. On the other hand, if the mass ratio of the (B) component to the (A) component and the (A') component described below is outside the above range, the properties such as curability, adhesive strength, and storage modulus intended by the present invention may not be achieved even if other components are adjusted.

[0038] Component (C) is an organohydrogenpolysiloxane having two or more Si-H bonds in the molecule, and is a crosslinking agent for the organopolysiloxane composition of the present invention. The molecular structure of component (C) is not limited, and examples thereof include linear, partially branched linear, branched, cyclic, and organopolysiloxane resin, and preferably linear, partially branched linear, or organopolysiloxane resin. The bonding position of the silicon-bonded hydrogen atom is not particularly limited, and examples thereof include the molecular chain terminal, the side chain, and both. The content of silicon-bonded hydrogen atoms is preferably from 0.1 to 2.0 mass %, and more preferably from 0.5 to 1.7 mass %.

[0039] Examples of organic groups bonded to silicon atoms include alkyl groups having 1 to 8 carbon atoms, such as methyl groups; aryl groups, such as phenyl groups; aralkyl groups; and halogenated alkyl groups, and it is preferable that at least 50 mol % of the total number of these groups are alkyl groups having 1 to 8 carbon atoms or phenyl groups. In terms of ease of production and compatibility with the above-mentioned preferred components (A) and (B), the other organic groups are preferably methyl groups or phenyl groups.

[0040] Specific examples of component (C) include tris(dimethylhydrogensiloxy)methylsilane, tetra(dimethylhydrogensiloxy)silane, methylhydrogenpolysiloxane capped at both ends with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer capped at both ends with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer capped at both ends with dimethylhydrogensiloxane, cyclic methylhydrogenoligosiloxane, cyclic methylhydrogensiloxane-dimethylsiloxane copolymer, methylhydrogensiloxane-diphenylsiloxane copolymer capped at both molecular chain ends with trimethylsiloxy groups, methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymer capped at both molecular chain ends with trimethylsiloxy groups, hydrolysis condensate of trimethoxysilane, (CH3)2HSiO 1 / 2 Units and SiO 4 / 2 A copolymer consisting of (CH3)2HSiO units. 1 / 2 Units and SiO 4 / 2 Units and (C6H5)SiO 3 / 2 A copolymer consisting of (CH3)2HSiO units. 1 / 2 Units and CH3SiO 3 / 2 units, and mixtures of two or more of these.

[0041] Component (D) is a characteristic component of the present invention, and is an organosilicon compound having an average of more than one alkenyl group in the molecule, and does not fall under the above-mentioned components (A) and (B). Such an organosilicon compound having an alkenyl group is usually an alkenyl-containing silane or an alkenyl-containing silane-siloxane reaction mixture used as an independent adhesion promoter in a curable siloxane composition, and is a component different from polyorganosiloxane components such as polydialkylsiloxanes and organopolysiloxane resin components. The reaction mixture of alkenyl-containing silane-siloxane may contain heteroatoms such as nitrogen atoms, and may be in the form of a reaction mixture containing a silatrane derivative or a carbasilatrane derivative having a structure in which the entire molecule is cyclized. In addition, these organosilicon compounds having an alkenyl group preferably function as an independent adhesion promoter, have a low degree of polymerization and a low viscosity, and preferably have a viscosity at 25°C in the range of 1 to 500 mPa·s, more preferably 1 to 350 mPa·s.

[0042] Suitable components (D) include: (d1) an organosilicon compound having at least one silicon-bonded alkenyl group and one silicon-bonded alkoxy group per molecule; (d2) an organosilicon compound having at least one silicon-bonded alkenyl group, one silicon-bonded alkoxy group, and one silicon-bonded epoxy-containing monovalent organic group per molecule; (d3) a reaction mixture of a silane or siloxane having at least one silicon-bonded alkoxy group per molecule and an organosiloxane having at least one silicon-bonded hydroxy group and one silicon-bonded alkenyl group per molecule; and (d4) A reaction mixture of an organosilane having at least one silicon-bonded alkoxy group and one silicon-bonded epoxy-containing monovalent organic group per molecule, an organosiloxane having at least one silicon-bonded hydroxy group or alkoxy group per molecule, and an organosiloxane having at least one silicon-bonded alkenyl group per molecule. Examples of the organic silicon compound include at least one organic silicon compound selected from the group consisting of:

[0043] Here, the organosilicon compounds of components (d1) and (d2) are preferably silanes having one silicon atom, silane oligomers having two to three silicon atoms, and siloxanes having a branched unit. In particular, component (d2) is preferably a compound having an EpSiO 1.5 (Ep is a silicon-bonded epoxy-containing monovalent organic group) and R 1 R 2 SiO 1.0 (R 1 is an alkenyl group having 2 to 12 carbon atoms, R 1 is preferably an organosilicon compound having a siloxane unit represented by (C1-12 alkyl group), which may further have a silicon-bonded hydroxy group or alkoxy group in the molecule. Since such component (d2) has at least one epoxy-containing mono-organic group in the molecule, it can impart good adhesion to various substrates, and is particularly preferred in terms of forming a pressure-sensitive adhesive layer having excellent tensile adhesive strength.

[0044] The organosilicon compounds of components (d3) and (d4) are obtained as a reaction mixture of functional silane / siloxane, and are preferably condensation reaction mixtures obtained by heating and mixing the components with stirring in the presence of a basic substance such as potassium hydroxide or sodium hydroxide.

[0045] In the present invention, a particularly preferred component (D) is (d4-1) a condensation reaction mixture of an organosilane having at least one silicon-bonded alkoxy group and one silicon-bonded epoxy-containing monovalent organic group per molecule, an organosiloxane having at least one silicon-bonded hydroxy group or alkoxy group per molecule, and an organosiloxane having at least one silicon-bonded alkenyl group per molecule, wherein the organosiloxane has EpSiO 1.5 (Ep is a silicon-bonded epoxy-containing monovalent organic group) and R 1 R2 SiO 1.0 (R 1 is an alkenyl group having 2 to 12 carbon atoms, R 1 is an organosilicon compound having a siloxane unit represented by (C1-12 alkyl group), and may further have a silicon-bonded hydroxy group or alkoxy group in the molecule. Such component (d4-1) has excellent handling and workability, cures quickly by a hydrosilylation curing reaction without impairing viscoelastic properties such as the shear storage modulus G' at room temperature, and has at least one epoxy-containing mono-organic group in the molecule, so that it can impart good adhesion to various substrates, and is particularly preferred in terms of forming a pressure-sensitive adhesive layer with excellent tensile adhesive strength.

[0046] Examples of the silicon-bonded epoxy-containing monovalent organic group include glycidoxyalkyl groups such as 3-glycidoxypropyl group and 4-glycidoxybutyl group; (3,4-epoxycyclohexyl)alkyl groups such as 2-(3,4-epoxycyclohexyl)ethyl group and 3-(3,4-epoxycyclohexyl)propyl group; and oxiranylalkyl groups such as 4-oxiranylbutyl group and 8-oxiranyloctyl group. The alkenyl group having 2 to 12 carbon atoms is the same as the above, and vinyl group, allyl group, or hexenyl group is preferable. Moreover, the alkyl group having 1 to 12 carbon atoms is industrially preferably methyl group.

[0047] [SiH / Vi ratio] The composition of the present invention is a hydrosilylation reaction curable composition, and is characterized in that the amount of silicon-bonded hydrogen atom (SiH) groups in component (C) is designed relative to the sum of the amount of alkenyl groups in components (A), (B), and (D), giving the pressure-sensitive adhesive layer-forming organopolysiloxane composition of the present invention excellent curing properties.

[0048] In the composition of the present invention, the amount of the (C) component used must be such that the molar ratio of the amount of silicon-bonded hydrogen atom (SiH) groups in the (C) component to the sum of the amounts (amounts) of alkenyl groups in the (A), (B) and (D) components in the composition is 1.0 or more, and is preferably in the range of 1.0 to 100, and may be in the range of 1.0 to 60, 1.5 to 55 or 2.0 to 50. Within this range, the composition of the present invention exhibits good curing properties. On the other hand, if the molar ratio is less than 1.0, the composition of the present invention may be insufficiently cured. On the other hand, if the amount of SiH groups exceeds the upper limit, the amount of curing agent remaining without reacting tends to increase, which may cause adverse effects on the cured physical properties, such as brittleness of the cured product, or problems such as gas generation.

[0049] On the other hand, the molar ratio of the amount of silicon-bonded hydrogen (SiH) groups in component (C) to the sum of the amounts (amount of substance) of alkenyl groups in components (A) and (B) in the composition (i.e., the amount excluding the alkenyl groups in component (D)) can be designed to be 10 or more, or 20 or more, and is preferred. In particular, for the purpose of improving the adhesion of the pressure-sensitive adhesive layer obtained by curing the present composition to a substrate such as glass, the amount of silicon-bonded hydrogen (SiH) groups in component (C) to the sum of the amounts (amount of substance) of alkenyl groups in component (A) and (B) in the composition is preferably designed to be in the range of 20 to 100, or 22 to 90. In addition to the use of component (D) which functions as an adhesion promoter and the condition of the amount of component (C) used taking into account the alkenyl groups in component (D), the technical effect of improving adhesion to substrates is more effectively achieved by designing the amount of component (C) used to be in the above range.

[0050] That is, in the present invention, the most suitable amount of component (C) used is the ratio (molar ratio) of the amount of SiH groups in component (C) to the sum of the amounts of alkenyl groups in components (A) and (B) is in the range of 20 to 100, The ratio (molar ratio) of the amount of SiH groups in component (C) to the sum of the amounts of alkenyl groups in components (A), (B), and (D) is in the range of 2.0 to 80. It is.

[0051] [Hydrosilylation reaction catalyst] The organopolysiloxane composition of the present invention contains (E) a hydrosilylation catalyst. Examples of hydrosilylation catalysts include platinum catalysts, rhodium catalysts, and palladium catalysts, with platinum catalysts being preferred because they can significantly accelerate the curing of the composition. As the platinum catalyst, a platinum-alkenylsiloxane complex is preferred, and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane is particularly preferred because the platinum-alkenylsiloxane complex has good stability. Note that non-platinum metal catalysts such as iron, ruthenium, and iron / cobalt may also be used as a catalyst for accelerating the hydrosilylation reaction.

[0052] In the present invention, the content of the hydrosilylation reaction catalyst is not particularly limited, but the platinum metal content 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. In practice, it is preferable that the content of the platinum metal excluding the ligand of the hydrosilylation reaction catalyst is in the above range. Note that the solid content refers to the components (mainly the base agent, adhesion imparting component, crosslinking agent, catalyst, and other non-volatile components) that form a cured layer when the organopolysiloxane composition according to the present invention is cured, and does not include volatile components such as solvents that volatilize during heat curing.

[0053] When the content of platinum-based metal in the 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 or coloring of the transparent pressure-sensitive adhesive layer may be particularly suppressed after curing or when exposed to high-energy rays such as heating or ultraviolet light. On the other hand, from the viewpoint of the curability of the organopolysiloxane composition, the content of platinum-based metal is 0.1 ppm or more, and if it is below this lower limit, it may cause poor curing.

[0054] Component (F) is a cure retarder that is added to inhibit the crosslinking reaction between the alkenyl groups in the composition and the SiH groups in component (C), thereby extending the pot life at room temperature and improving storage stability. Therefore, from a practical standpoint, it is a nearly essential component for the pressure-sensitive adhesive layer-forming organopolysiloxane composition of the present invention.

[0055] Specifically, the (E) component can be exemplified by acetylene compounds, enyne compounds, organic nitrogen compounds, organic phosphorus compounds, and oxime compounds.Specifically, the (E) component can be exemplified by alkyne alcohols such as 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, 1-ethynyl-1-cyclohexanol, and phenylbutynol; enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-1-hexyn-3-yne; 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 methylalkenylcyclosiloxane; and benzotriazole. Note that a portion of the cyclic siloxane component (E) also functions as component (A).

[0056] From the viewpoint of the curing behavior of the composition, it is preferable that the pressure-sensitive adhesive layer-forming organopolysiloxane composition of the present invention has a viscosity increase of no more than 1.5 times 8 hours after preparation at room temperature and is curable at 80 to 200°C. Suppression of viscosity increase is important from the viewpoints of handling, pot life, and post-curing properties, because even if a large excess of component (C) is contained and the platinum-based metal content is optionally low, curability can be ensured by curing at a certain high temperature (80 to 200°C) or higher. Note that such a composition can be realized by selecting a suitable combination and blending amount of each of the above components, the hydrosilylation catalyst, and component (E) as described above.

[0057] The organopolysiloxane composition according to the present invention may contain an organic solvent as a solvent in addition to the above components. The type and amount of the organic solvent are adjusted in consideration of coating workability and the like. Examples of organic solvents include aromatic hydrocarbon solvents such as toluene, xylene, and benzene, aliphatic hydrocarbon solvents such as heptane, hexane, octane, and isoparaffin, ester solvents such as ethyl acetate and isobutyl acetate, ether solvents such as diisopropyl ether and 1,4-dioxane, chlorinated aliphatic hydrocarbon solvents such as trichloroethylene, perchloroethylene, and methylene chloride, and solvent volatile oils, and two or more of them may be combined depending on the wettability of the sheet-like substrate. The amount of the organic solvent to be added is preferably an amount that allows the mixture of components (A) to (C) to be uniformly applied to the surface of the sheet-like substrate, for example, 5 to 3,000 parts by mass per 100 parts by mass of the total of components (A), (B), and (C).

[0058] The organopolysiloxane composition of the present invention may optionally contain components other than those described above, provided that the technical effects of the present invention are not impaired. For example, it may contain antioxidants, light stabilizers, flame retardants, antistatic agents, etc. In addition to these components, pigments, dyes, inorganic fine particles (reinforcing fillers, dielectric fillers, conductive fillers, thermally conductive fillers), etc. may also be optionally blended.

[0059] [(A') A chain organopolysiloxane that does not contain a carbon-carbon double bond-containing reactive group in the molecule] The organopolysiloxane composition of the present invention can optionally contain a non-reactive organopolysiloxane such as polydimethylsiloxane or polydimethyldiphenylsiloxane that does not contain a carbon-carbon double bond-containing reactive group such as an alkenyl group, an acrylic group, or a methacrylic group, which may improve the loss factor (tan δ), storage modulus (G'), and loss modulus (G'') of the pressure-sensitive adhesive layer. For example, the loss factor of the pressure-sensitive adhesive layer can be increased by using a polydimethylsiloxane having a hydroxyl group terminal, or a polydimethylsiloxane or polydimethyldiphenylsiloxane having a trimethylsiloxy terminal, and such compositions are within the scope of the present invention.

[0060] Here, the (A') component is a linear organopolysiloxane that does not participate in the curing reaction by hydrosilylation, and the mass ratio of the (A') component to the (B) component in the composition can affect the properties of the composition, such as the adhesive strength and storage modulus. As described above, the mass ratio of the (B) component to the (A) and (A') components may be in the range of 1.1 to 3.0, and may be 1.4 or more, 1.5 or more, or 2.0 or more to achieve the desired adhesive strength and storage modulus, and the range of 1.4 to 3.0 is particularly preferable. In addition, in the case of the purpose of suppressing the storage modulus of the composition, even if the mass ratio of the (B) component to the (A) and (A') components is designed to be high, the mass ratio of the (A) component to the (A') component may be designed to be in the range of 100:0 to 60:40, 100:0 to 65:35, 90:10 to 65:35, 85:15 to 70:30, etc.

[0061] The method for preparing the organopolysiloxane composition of the present invention is not particularly limited, and the composition is prepared by mixing the components homogeneously. If necessary, a solvent may be added, and the components may be mixed at a temperature of 0 to 200°C using a known stirrer or kneader.

[0062] The organopolysiloxane composition of the present invention is applied onto a substrate to form a coating film, and then heated at a temperature of 80 to 200° C., preferably at a temperature of 90 to 190° C., to form a cured product. Examples of the coating method include gravure coating, offset coating, offset gravure, roll coating, reverse roll coating, air knife coating, curtain coating, and comma coating. The amount of coating can be designed to a desired thickness depending on the application, such as a display device. For example, the thickness of the pressure-sensitive adhesive layer after curing is 1 to 1,000 μm, may be 5 to 900 μm, or may be 10 to 800 μm, but is not limited thereto.

[0063] [Pressure-sensitive adhesive and adhesion range] The organopolysiloxane composition of the present invention is characterized in that the cured layer obtained by curing the composition by a hydrosilylation reaction has pressure-sensitive adhesive properties. The pressure-sensitive adhesive layer of the present invention has the above-mentioned configuration and exhibits sufficient adhesive strength for practical use, so that it can be used as a replacement for known silicone pressure-sensitive adhesives as desired.

[0064] Specifically, it is possible to design a pressure-sensitive adhesive layer having a thickness of 50 μm obtained by curing the organopolysiloxane composition of the present invention, in which the adhesive strength measured against a polymethyl methacrylate sheet having a thickness of 2 mm using a 180° peel test method according to JIS Z 0237 at a tensile speed of 300 mm / min is in the range of 360 to 4000 gf / inch, and a pressure-sensitive adhesive layer having a range of 1300 to 3500 gf / inch is preferable. Note that the above thickness (50 μm) is the thickness of the cured layer itself, which is the standard for objectively defining the adhesive strength of the cured layer according to the present invention, and it goes without saying that the organopolysiloxane composition of the present invention can be used as a cured layer or pressure-sensitive adhesive layer of any thickness, not limited to a thickness of 50 μm.

[0065] [Storage modulus and other mechanical properties] The pressure-sensitive adhesive layer-forming organopolysiloxane composition of the present invention can be designed so that the pressure-sensitive adhesive layer obtained by curing has a shear storage modulus G' at 25°C in the range of 0.005 to 20.00 MPa. The storage modulus G' may be in the range of 0.10 to 20.00 MPa, or may be in the range of 1.00 to 20.00 MPa, and those in the range of 1.50 to 18.00 MPa are also preferably included in the scope of the present invention.

[0066] Furthermore, the stress at 500% strain at 25° C. of the pressure-sensitive adhesive layer obtained by curing the composition of the present invention can be designed to be in the range of 0.005 MPa to 3 MPa, and may be 0.20 MPa to 3 MPa.

[0067] Since the organopolysiloxane composition capable of forming a pressure-sensitive adhesive layer of the present invention has such a storage modulus G' and tensile stress at room temperature (25°C) and also has the above-mentioned practical adhesive strength, it is suitable for use in forming elastic adhesive members as components for electronic devices and electrical equipment such as speakers and transducers, as well as for application in the field of advanced electronic materials and display elements for smart devices and the like.

[0068] The storage modulus (G') of the pressure-sensitive adhesive layer according to the present invention can be measured by a known measurement method. For example, the storage modulus (G') can be measured using an MCR301 viscoelasticity measuring device (manufactured by Anton Paar), and can be obtained as a value at 25°C by measuring a disk-shaped sample having a diameter of about 8 mm and a thickness of about 0.5 to 1 mm, using 8 mm parallel plates, a frequency of 1 Hz, a strain of 0.1%, and a heating rate of 3°C / min in the range of -70°C to 250°C.

[0069] The pressure-sensitive adhesive layer according to the present invention may have a storage modulus G' at 1.0 Hz at -20°C that is at least three times the storage modulus G' at 1.0 Hz at 25°C.

[0070] [Transparency, color tone, or color change characteristics of pressure-sensitive adhesive layer] The organopolysiloxane composition of the present invention may be substantially transparent, translucent or opaque, and the transparency can be designed according to the application of the pressure-sensitive adhesive layer. In addition, when it is transparent to the naked eye, more objectively, the transmittance of light with a wavelength of 450 nm of the pressure-sensitive adhesive layer for a display device consisting of a cured layer having a thickness of 100 μm is 80% or more, preferably 90% or more, and may be designed to be 95% or more, assuming that the value of air is 100%. On the other hand, in the case of bonding electric and electronic parts that do not require light transmittance, the pressure-sensitive adhesive layer may be translucent to opaque, and filler components or additives that impair colorability or light transmittance may be used according to required properties other than light transmittance.

[0071] The organopolysiloxane composition of the present invention can be designed so that the cured product is not colored in addition to the above-mentioned transparency by optionally reducing the content of platinum-based metals in the cured layer, etc. Furthermore, the cured layer of the present invention can be designed so that its color tone does not change significantly, and in particular so that the problem of yellowing does not occur, even when exposed to high temperatures or high-energy rays such as ultraviolet rays for a long period of time.

[0072] [Use as a pressure-sensitive adhesive layer] The cured product of the present invention can be used as a pressure-sensitive adhesive layer in particular. In addition, in order to improve adhesion to an adherend, the surface of the pressure-sensitive adhesive layer or the substrate may be subjected to surface treatment such as primer treatment, corona treatment, etching treatment, plasma treatment, etc. However, since the pressure-sensitive adhesive layer of the present invention has excellent adhesion to substrates such as display devices as described above, these steps may be added as necessary to further improve adhesion to the adherend, and these steps may be omitted to achieve higher production efficiency.

[0073] The curable organopolysiloxane composition according to the present invention can be applied to a release liner, cured by heating under the above-mentioned temperature conditions, and the release liner can be peeled off and the composition can be attached to a film-like substrate, a tape-like substrate, or a sheet-like substrate (hereinafter referred to as a "film-like substrate"), or the composition can be applied to a film-like substrate and cured by heating under the above-mentioned temperature conditions to form a pressure-sensitive adhesive layer on the surface of the substrate. A laminate having a cured layer, particularly a film-like pressure-sensitive adhesive layer, formed by curing the organopolysiloxane composition according to the present invention on these film-like substrates can be used for adhesive tapes, bandages, low-temperature supports, transfer films, labels, emblems, and decorative or explanatory signs. Furthermore, the cured layer formed by curing the organopolysiloxane composition according to the present invention can be used in the assembly of automobile parts, toys, electronic circuits, or keyboards. Alternatively, the cured layer formed by curing the organopolysiloxane composition according to the present invention, particularly a film-like pressure-sensitive adhesive layer, can be used in the construction and use of laminated touch screens or flat panel displays. The surface of the film substrate opposite the pressure-sensitive adhesive layer may be subjected to a surface treatment such as treatment to prevent scratches, stains, fingerprints, glare, reflection, or static electricity.

[0074] Examples of substrate types include paperboard, corrugated cardboard, clay-coated paper, polyolefin-laminated paper, especially polyethylene-laminated paper, synthetic resin film / sheet, natural fiber cloth, synthetic fiber cloth, artificial leather cloth, and metal foil.

[0075] The substrate is preferably in the form of a film or sheet. Its thickness is not particularly limited and can be designed to a desired thickness depending on the application. Furthermore, in order to improve the adhesion between the support film and the pressure-sensitive adhesive layer, a support film that has been subjected to a primer treatment, a corona treatment, an etching treatment, or a plasma treatment may be used. In addition, the surface opposite to the pressure-sensitive adhesive layer of the film-like substrate may be surface-treated, such as to prevent scratches, to prevent dirt, to prevent fingerprints, to prevent glare, to prevent reflection, or to prevent static electricity.

[0076] As a method for coating the substrate, gravure coating, offset coating, offset gravure, roll coating using an offset transfer roll coater or the like, reverse roll coating, air knife coating, curtain coating using a curtain flow coater or the like, comma coating, Mayer bar, and other known methods used for forming a cured layer can be used without any limitations.

[0077] The coating amount can be designed to a desired thickness depending on the application, such as a display device. As an example, the thickness of the pressure-sensitive adhesive layer after curing is 1 to 1,000 μm, may be 5 to 900 μm, or may be 10 to 800 μm, but is not limited to these.

[0078] The pressure-sensitive adhesive layer according to the present invention may be a single layer or a multilayer formed by laminating two or more pressure-sensitive adhesive layers depending on the required properties. The multilayer pressure-sensitive adhesive layer may be formed by laminating pressure-sensitive adhesive films prepared one by one, or a process of applying and curing a pressure-sensitive adhesive layer-forming organopolysiloxane composition onto a film substrate provided with a release layer may be carried out multiple times.

[0079] The pressure-sensitive adhesive layer according to the present invention may be given the role of other functional layers selected from a dielectric layer, a conductive layer, a heat dissipation layer, an insulating layer, a reinforcing layer, etc., in addition to the adhesive or cohesive function between members.

[0080] When the cured layer obtained by curing the organopolysiloxane composition of the present invention is a pressure-sensitive adhesive layer, particularly a pressure-sensitive adhesive film, it is preferable to handle the cured layer as a laminate film that is peelably attached to a film substrate having a release layer with release coating ability.The release layer may be 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 that forms physically fine irregularities on the substrate surface or is difficult to adhere to the pressure-sensitive adhesive layer of the present invention, and it is preferable to use a release layer obtained by curing a fluorosilicone-based release agent.In addition, in the laminate, the release layer may be a differential release layer that is a first release layer and a second release layer that are different in type and release force of the release agent that constitutes the release layer, and the fluorosilicone-based release agent may be a curing reactive silicone composition that contains one or more fluorine-containing groups selected from a fluoroalkyl group and a perfluoropolyether group.

[0081] The cured product obtained by curing the organopolysiloxane composition of the present invention has both the above-mentioned viscoelasticity and adhesive strength, and is therefore useful as an elastic adhesive member for various electronic devices or electrical devices. In particular, it is useful as an electronic material, a display device member, or a transducer member (including sensors, speakers, actuators, and generators), and the preferred use of the cured product is as a member of an electronic component or a display device. The cured product of the present invention may be transparent or opaque, but a film-shaped cured product, particularly a substantially transparent pressure-sensitive adhesive film, is suitable as a member for a display panel or display, and is particularly useful for so-called touch panel applications in which devices, particularly electronic devices, can be operated by touching the screen with fingertips or the like. In addition, the opaque elastic adhesive layer is particularly useful for applications as film- or sheet-shaped members used in sensors, speakers, actuators, etc., which do not require transparency and require a certain degree of stretchability or flexibility in the adhesive layer itself.

[0082] In particular, a pressure-sensitive adhesive layer obtained by curing the organopolysiloxane composition of the present invention can achieve pressure-sensitive adhesive properties equivalent to those of conventional silicone pressure-sensitive adhesive layers, and can improve adhesion to substrates such as display devices without causing problems of poor curing or reduced curing properties.

[0083] [Display panel or display components] The cured product obtained by curing the organopolysiloxane composition of the present invention can be used in the construction and use of a laminated touch screen or flat panel display, and the specific method of use thereof can be any known method for using a pressure-sensitive adhesive layer (particularly a silicone PSA) without any particular limitation.

[0084] For example, a cured product obtained by curing the organopolysiloxane composition of the present invention can be used in the manufacture of a display device such as a touch panel as an optically transparent silicone-based pressure-sensitive adhesive film or pressure-sensitive adhesive layer disclosed in the above-mentioned JP-T 2014-522436 or JP-T 2013-512326, etc. In addition, a cured product obtained by curing the organopolysiloxane composition of the present invention may be used as an adhesive film for a polarizing plate used in the manufacture of a display device such as a touch panel, or as a pressure-sensitive adhesive layer used for bonding between a touch panel and a display module as described in JP-A 2013-065009. [Industrial Applicability]

[0085] The curing reactive organopolysiloxane composition of the present invention and the cured product obtained by curing the composition are not limited to the above-mentioned uses, and the pressure-sensitive adhesive film comprising the 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 thereof include curved displays or curved transmission screens used in automobiles (including electric automobiles) and aircraft, as well as various flat panel displays (FPDs). Furthermore, these display devices can display icons for executing functions or programs on the screen or display, notification displays such as e-mail and programs, and operation buttons for various devices such as car navigation devices, audio devices, and air conditioners, and may be provided with a touch panel function that allows input operations by touching these icons, notification displays, and operation buttons with a finger. Furthermore, the cured product obtained by curing the composition has excellent adhesiveness and viscoelastic properties, and can therefore be used as a film or sheet-like member that is a transducer member (including those for sensors, speakers, actuators, and generators) such as a membrane for a speaker, and can also be used as a sealing layer or adhesive layer for a secondary battery, a fuel cell, or a solar cell module.

[0086] In addition, JP 2017-047767 A, JP 2014-182335 A, JP 2014-063064 A, JP 2013-233852 A, and the like disclose vehicle display devices having a curved display surface, and the pressure-sensitive adhesive layer of the present invention can be suitably applied or replaced as part or all of the adhesive layer or pressure-sensitive adhesive layer in these documents that require transparency. EXAMPLES

[0087] Examples and Comparative Examples of the present invention are described below. In each Example, Comparative Example, and Reference Example, "cured" means that each composition was completely cured under each curing condition.

[0088] (Preparation of Curable Reactive Organopolysiloxane Composition) The curable organopolysiloxane compositions shown in the Examples, Comparative Examples, and Reference Examples were prepared using the components shown in Table 1. Note that all % in Table 1 is by mass %.

[0089] (Measurement of molecular weight of organopolysiloxane component) 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 using a Waters gel permeation chromatography (GPC) with tetrahydrofuran (THF) as a solvent. (Measurement of hydroxyl (OH) content in organopolysiloxane resin) Bruker ACP-300 with glass-free probe 29 Using a Si NMR spectrometer, the chemical shift of Si(OH)O appears at -93 to -103.5 ppm when the chemical shift of tetramethylsilane is set at 0 ppm. 2 / 3 The molar content was calculated from the ratio of the units to the total silicon, and was then converted into the mass% of hydroxyl groups (OH) in the organopolysiloxane resin. Note that the organopolysiloxane resins in the following examples did not contain any hydrolyzable functional groups other than hydroxyl groups. (Adhesive strength measurement) Each composition was applied to a PET film (manufactured by Toray Industries, Inc., product name Lumirror (registered trademark) S10, thickness 50 μm) so that the thickness after curing was 50 μm, and cured at 150 ° C for 3 minutes. After leaving it for 1 day, the sample was cut to a width of 20 mm, and the adhesive layer surface was attached to a PMMA plate (manufactured by Paltec, Acrylite L001, 50 x 120 x 2 mm) using a roller to prepare a test piece. The test piece using the PMMA plate was measured for adhesive strength (measurement at a width of 20 mm was converted to gf / inch) using a 180 ° peel test method according to JIS Z0237 using an Orientec RTC-1210 tensile tester at a tensile speed of 300 mm / min. (Dynamic viscoelasticity: Storage modulus G' at 25℃) Each composition was applied to a release liner coated with a fluorosilicone release coating so that the thickness after curing was about 100 μm, and cured at 150 ° C for 3 minutes. Five or more sheets of this pressure-sensitive adhesive film were stacked to obtain a film sample with a thickness of 500 μm or more, sandwiched between release liners on both sides. The film was cut out to a diameter of 8 mm and attached to a parallel plate probe of a dynamic viscoelasticity device (Made by Anoton Paar, MCR301) to measure the storage modulus G'. The measurement conditions were in the range of -70 ° C to 250 ° C, a frequency of 1 Hz, and a heating rate of 3 ° C / min. The loss factor, storage modulus G', and loss modulus G'' were measured, and the storage modulus G' at 25 ° C was recorded (unit: MPa). (Tensile test) A film sample with a thickness of 500 μm or more, sandwiched between release liners on both sides, obtained in the same manner as the above dynamic viscoelasticity test sample, was cut to a width of approximately 5 mm and a length of approximately 70 mm, and the release liner was peeled off while applying baby powder to the adhesive surface to prepare a tensile test sample. The tensile test was performed using Shimadzu Autograph AGS-X, holding the sample at approximately 25 mm above and below, at a speed of 300 mm / min. The stress and strain were determined for each sample from the exact sample width, thickness, and crosshead distance, and the stress at 500% strain was recorded (unit: MPa). (Tensile adhesive strength) Each composition was applied to a release liner coated with a fluorosilicone release coating so that the thickness after curing was about 200 μm, cured at 150 ° C for 3 minutes, and another release liner was laminated to the adhesive surface. The sample was cut into 5 mm squares, the release liner was peeled off, and the adhesive layer was laminated between two PMMA plates (Partec, Acrylite L001, 75 x 25 x 2 mm) combined in a cross shape to prepare a test piece. Using Shimadzu Autograph AGS-X, a tool was used to hold the upper and lower PMMA plates, and a tensile test was performed at a speed of 100 mm / min so that the adhesive surface was peeled off vertically, and the stress at break was measured.

[0090] The materials of the curable reactive organopolysiloxane composition are shown in Table 1. The viscosity or plasticity of each component was measured at room temperature by the following method. [viscosity] Viscosity (mPa s) is a value measured using a rotational viscometer conforming to JIS K7117-1, and kinematic viscosity (mm 2 / s) is a value measured using an Ubbelohde viscometer conforming to JIS Z8803. [Plasticity] The plasticity was measured according to the method specified in JIS K 6249 (a 4.2 g spherical sample was subjected to a load of 1 kgf for 3 minutes at 25°C, the thickness was read to the nearest 1 / 100 mm, and this value was multiplied by 100).

[0091] Table 1. Components of the curable organopolysiloxane composition [Table 1] *Condensation reaction mixture of 3-glycidoxypropyltrimethoxysilane, silanol-terminated dimethylpolysiloxane, and 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane in the presence of potassium hydroxide

[0092] Example 1 36.4 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 99.4 parts by weight of MQ silicone resin of component b1, 30.9 parts by weight of toluene, 1.30 parts by weight of methylhydrogenpolysiloxane of component c1, 0.491 parts by weight of 20% solution of cure retarder of component f, and 2.00 parts by weight of alkenyl-containing organosilicon compound (adhesion promoter) of component d were mixed well at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to obtain a curing reactive organopolysiloxane composition. The molar ratio (SiH / Vi ratio) of SiH group in component c1 to the amount of alkenyl group in component a2 was 28.7, the molar ratio (SiH / Vi ratio) of SiH group in component c1 to the sum of alkenyl group in component a2 and alkenyl group in component d was 5.00, and the content of platinum metal in solids was 22 ppm. The composition was cured by the above method, and the viscoelasticity, stress-strain, adhesive strength to a PMMA plate, and tensile adhesive strength were measured by the above methods. The evaluation results are shown in Table 2.

[0093] Example 2 32.3 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 100.8 parts by weight of MQ silicone resin of component b1, 4.3 parts by weight of MQ silicone resin of component b2, 29.3 parts by weight of toluene, 1.56 parts by weight of methylhydrogenpolysiloxane of component c1, 0.491 parts by weight of a 20% solution of cure retarder of component f, and 2.00 parts by weight of alkenyl-containing organosilicon compound (adhesion promoter) of component d were thoroughly mixed at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to prepare a curable organopolysiloxane composition. The molar ratio of SiH groups in component c1 to the amount of alkenyl groups in component a2 (SiH / Vi ratio) was 31.7, the molar ratio of SiH groups in component c2 to the sum of the alkenyl groups in component a2 and the alkenyl groups in component d (SiH / Vi ratio) was 5.00, and the platinum metal content relative to the solid content was 22 ppm. The composition was cured by the above method, and the viscoelasticity, stress-strain, adhesive strength to a PMMA plate, and tensile adhesive strength were measured by the above methods. The evaluation results are shown in Table 2.

[0094] Example 3 32.3 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 100.8 parts by weight of MQ silicone resin of component b1, 4.3 parts by weight of MQ silicone resin of component b2, 29.3 parts by weight of toluene, 3.74 parts by weight of methylhydrogenpolysiloxane of component c1, 0.491 parts by weight of a 20% solution of cure retarder of component f, and 2.00 parts by weight of alkenyl-containing organosilicon compound (adhesion promoter) of component d were thoroughly mixed at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to prepare a curable organopolysiloxane composition. The molar ratio of SiH groups in component c1 to the amount of alkenyl groups in component a2 (SiH / Vi ratio) was 76.2, the molar ratio of SiH groups in component c1 to the sum of the alkenyl groups in component a2 and the alkenyl groups in component d (SiH / Vi ratio) was 12.0, and the platinum metal content relative to the solid content was 22 ppm. The composition was cured by the above method, and the viscoelasticity, stress-strain, adhesive strength to a PMMA plate, and tensile adhesive strength were measured by the above methods. The evaluation results are shown in Table 2.

[0095] ( Comparative Example 6 ) 36.4 parts by weight of vinyl-functional polydimethylsiloxane of component a1, 99.4 parts by weight of MQ silicone resin of component b1, 86.4 parts by weight of toluene, 0.349 parts by weight of methylhydrogenpolysiloxane of component c1, 0.409 parts by weight of 20% solution of cure retarder of component f, and 1.00 parts by weight of alkenyl-containing organosilicon compound (adhesion promoter) of component d were mixed well at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component f was added to the mixture to obtain a curing reactive organopolysiloxane composition. The molar ratio (SiH / Vi ratio) of SiH groups in component c1 to the amount of alkenyl groups in component a1 was 31.6, the molar ratio (SiH / Vi ratio) of SiH groups in component c1 to the sum of alkenyl groups in component a1 and alkenyl groups in component d was 2.43, and the content of platinum metal in the solid content was 22 ppm. The composition was cured by the above method, and the viscoelasticity, stress-strain, adhesive strength to a PMMA plate, and tensile adhesive strength were measured by the above methods. The evaluation results are shown in Table 2.

[0096] Comparative Example 1 36.4 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 99.4 parts by weight of MQ silicone resin of component b1, 86.4 parts by weight of toluene, 0.298 parts by weight of methylhydrogenpolysiloxane of component c1, 0.491 parts by weight of 20% solution of cure retarder of component f, and 2.00 parts by weight of alkenyl-containing organosilicon compound (adhesion promoter) of component d were mixed well at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to obtain a curing reactive organopolysiloxane composition. The molar ratio (SiH / Vi ratio) of SiH group in component c1 to the amount of alkenyl group in component a2 was 5.40, the molar ratio (SiH / Vi ratio) of SiH group in component c1 to the sum of the amount of alkenyl group in component a2 and the amount of alkenyl group in component d was 0.94, and the content of platinum metal in solids was 22 ppm. An attempt was made to cure the composition using the method described above, but it did not cure.

[0097] Comparative Example 2 32.3 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 100.8 parts by weight of MQ silicone resin of component b1, 4.3 parts by weight of MQ silicone resin of component b2, 84.9 parts by weight of toluene, 0.266 parts by weight of methylhydrogenpolysiloxane of component c1, 0.491 parts by weight of a 20% solution of cure retarder of component f, and 2.00 parts by weight of an alkenyl-containing organosilicon compound (adhesion promoter) of component d were thoroughly mixed at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to prepare a curable organopolysiloxane composition. The molar ratio of SiH groups in component c2 to the amount of alkenyl groups in component a2 (SiH / Vi ratio) was 5.40, the molar ratio of SiH groups in component c1 to the sum of the alkenyl groups in component a2 and the alkenyl groups in component d (SiH / Vi ratio) was 0.85, and the platinum metal content relative to the solid content was 22 ppm. An attempt was made to cure the composition using the method described above, but it did not cure.

[0098] (Comparative Example 3) #254 36.4 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 99.4 parts by weight of MQ silicone resin of component b1, 30.9 parts by weight of toluene, 0.298 parts by weight of methylhydrogenpolysiloxane of component c1, and 0.491 parts by weight of 20% solution of cure retarder of component f were mixed well at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to obtain a curable organopolysiloxane composition. The molar ratio (SiH / Vi ratio) of SiH groups in component c1 to the amount of alkenyl groups in component a2 was 5.40, and the content of platinum metal relative to the solid content was 22 ppm. The composition was cured by the above method, and the viscoelasticity, stress-strain, adhesive strength to a PMMA plate, and tensile adhesive strength were measured by the above methods. The evaluation results are shown in Table 2.

[0099] Comparative Example 4 32.3 parts by weight of vinyl-functional polydimethylsiloxane of component a2, 100.8 parts by weight of MQ silicone resin of component b1, 4.3 parts by weight of MQ silicone resin of component b2, 84.9 parts by weight of toluene, 0.266 parts by weight of methylhydrogenpolysiloxane of component c1, 0.491 parts by weight of 20% solution of cure retarder of component f were mixed well at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to obtain a curable organopolysiloxane composition. The molar ratio (SiH / Vi ratio) of SiH group in component c1 to the amount of alkenyl group in component a2 was 5.40, and the content of platinum metal in the solid content was 22 ppm. The composition was cured by the above method, and the viscoelasticity, stress-strain, adhesive strength to a PMMA plate, and tensile adhesive strength were measured by the above methods. The evaluation results are shown in Table 2.

[0100] Comparative Example 5 36.4 parts by weight of vinyl-functional polydimethylsiloxane of component a1, 99.4 parts by weight of MQ silicone resin of component b1, 86.4 parts by weight of toluene, 0.349 parts by weight of methylhydrogenpolysiloxane of component c1, 0.409 parts by weight of 20% solution of cure retarder of component f, and 3.00 parts by weight of alkenyl-containing organosilicon compound (adhesion promoter) of component d were mixed well at room temperature, and 0.355 parts by weight of platinum-based hydrosilylation reaction catalyst of component e was added to the mixture to obtain a curing reactive organopolysiloxane composition. The molar ratio (SiH / Vi ratio) of SiH groups in component c1 to the amount of alkenyl groups in component a1 was 31.6, the molar ratio (SiH / Vi ratio) of SiH groups in component c1 to the sum of alkenyl groups in component a1 and alkenyl groups in component d was 0.87, and the content of platinum metal in the solid content was 22 ppm. An attempt was made to cure the composition using the method described above, but it did not cure.

[0101] [Table 2]

[0102] [Summary] As shown in Table 2, Examples 1 to 3 The pressure-sensitive adhesive layer-forming organopolysiloxane composition according to the above has sufficient curability, and the storage modulus G' at 25°C can be designed in a wide range of 1.0 MPa or more, the stress at 500% strain is 0.20 MPa or more, and the adhesive strength to PMMA can be designed to be 1300 gf / inch or more. This makes it possible to obtain an organopolysiloxane composition capable of forming a pressure-sensitive adhesive layer that has excellent curing reactivity, adhesive strength sufficient for practical use, and viscoelastic properties such as the storage modulus that can be designed in a wide range.

[0103] On the other hand, in Comparative Examples 1, 2, and 5, in which the SiH / Vi ratio was outside the range of the present invention, no curing occurred even when component d was used. In contrast, Example 1 and Comparative Example 3, and Example 2 and Comparative Example 4 have the same composition except for component d, but when comparing the tensile bond strength between the Comparative Examples and the Examples, the Example to which component d was added showed a higher value. In other words, even though the compositions have similar SiH / Vi ratios to the compositions using component d, the adhesive properties of the compositions of the Comparative Examples cannot be sufficiently improved.

Claims

1. (A) a linear or cyclic organopolysiloxane having an average of more than one alkenyl group in the molecule, (B) an organopolysiloxane resin in which the sum of the contents of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol % or less; (C) an organohydrogenpolysiloxane having at least two Si—H bonds in the molecule; (D) an organosilicon compound having an average of more than one alkenyl group per molecule (excluding components corresponding to components (A) and (B)); (E) an effective amount of a hydrosilylation reaction catalyst, and Optionally, (A') a linear organopolysiloxane that does not contain a carbon-carbon double bond-containing reactive group in the molecule. The composition comprises the amount of component (C) is an amount such that the ratio (molar ratio) of the amount of substance of SiH groups in component (C) to the sum of the amounts of substances of alkenyl groups in components (A), (B), and (D) is 5.0 or more, The component (D) is (d1) an organosilicon compound having at least one silicon-bonded alkenyl group and one silicon-bonded alkoxy group per molecule; (d2) an organosilicon compound having, per molecule, at least one silicon-bonded alkenyl group, one silicon-bonded alkoxy group, and one silicon-bonded epoxy-containing monovalent organic group; (d3) a reaction mixture of a silane or siloxane having at least one silicon-bonded alkoxy group per molecule and an organosiloxane having at least one silicon-bonded hydroxy group and one silicon-bonded alkenyl group per molecule; and (d4) A reaction mixture of an organosilane having at least one silicon-bonded alkoxy group and one silicon-bonded epoxy-containing monovalent organic group per molecule, an organosiloxane having at least one silicon-bonded hydroxy group per molecule, and an organosiloxane having at least one silicon-bonded alkenyl group per molecule. At least one organosilicon compound selected from the group consisting of: An organopolysiloxane composition capable of forming a pressure-sensitive adhesive layer.

2. The component (D) is (d4-1) A condensation reaction mixture of an organosilane having at least one silicon-bonded alkoxy group and one silicon-bonded epoxy-containing monovalent organic group per molecule, an organosiloxane having at least one silicon-bonded hydroxy group or alkoxy group per molecule, and an organosiloxane having at least one silicon-bonded alkenyl group per molecule, wherein the following are contained in the molecule: EpSiO １．５ (Ep is a silicon-bonded epoxy-containing monovalent organic group), and １ R ２ SiO １．０ (R １ 2. The pressure-sensitive adhesive layer-forming organopolysiloxane composition according to claim 1, which is an organosilicon compound having a siloxane unit represented by the following formula:

3. 3. The pressure-sensitive adhesive layer-forming organopolysiloxane composition according to claim 1, wherein component (D) is an adhesion promoter.

4. 4. The organopolysiloxane composition for forming a pressure-sensitive adhesive layer according to claim 1, wherein the mass ratio of component (B) to the sum of components (A) and (A') is in the range of 0.9 to 3.0, the pressure-sensitive adhesive layer obtained by curing the composition has a shear storage modulus G' at 25°C of 0.005 MPa to 20 MPa and a stress at 500% strain at 25°C of 0.005 MPa to 3 MPa, and the pressure-sensitive adhesive layer having a thickness of 50 µm obtained by curing the composition has an adhesion strength of 360 gf / inch to 4000 gf / inch against a polymethyl methacrylate sheet having a thickness of 2 mm, as measured using a 180° peel test method in accordance with JIS Z 0237 at a tensile speed of 300 mm / min.

5. 5. The organopolysiloxane composition capable of forming a pressure-sensitive adhesive layer according to claim 1, wherein the amount of component (C) is an amount such that the ratio (molar ratio) of the amount of substance of SiH groups in component (C) to the sum of the amounts of substances of alkenyl groups in components (A) and (B) is in the range of 20 to 100.

6. 6. The organopolysiloxane composition capable of forming a pressure-sensitive adhesive layer according to any one of claims 1 to 5, wherein the amount of component (C) is such that the ratio (molar ratio) of the amount of substance of SiH groups in component (C) to the sum of the amounts of substances of alkenyl groups in components (A), (B), and (D) is in the range of 2.0 to 50.

7. 7. The pressure-sensitive adhesive layer-forming organopolysiloxane composition according to claim 1, wherein the component (B) is an organopolysiloxane resin mixture containing the following components (b1) and (b2) in a mass ratio of 1:99 to 99:1: (b1) an organopolysiloxane resin in which the sum of the content of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol % or less and the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) relative to standard polystyrene is 4,500 or more; (b2) An organopolysiloxane resin in which the sum of the content of hydroxyl groups and hydrolyzable groups relative to the total silicon atoms in the molecule is 9 mol % or less, and the weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) relative to standard polystyrene is less than 4,500.

8. At least a portion of component (A) is (A1) a crude rubber-like alkenyl-containing organopolysiloxane having a viscosity of 100,000 mPa·s or more at 25°C or a plasticity in the range of 50 to 200 as measured in accordance with the method specified in JIS K6249, and the vinyl (CH ２ a linear organopolysiloxane having a content of (=CH) moieties in the range of 0.005 to 0.400 mass %, The organopolysiloxane resin mixture of component (B) is ３ SiO １／２ units (wherein R is a monovalent organic group, and 90 mol % or more of R are alkyl groups or phenyl groups having 1 to 6 carbon atoms; M units) and SiO ４／２ An organopolysiloxane resin mixture consisting essentially of units (Q units), 8. The pressure-sensitive adhesive layer-forming organopolysiloxane composition according to claim 1, wherein the amount of component (E) is such that the platinum-based metal content in the solid content of the composition is in the range of 0.1 to 200 ppm.

9. 9. The organopolysiloxane composition for forming a pressure-sensitive adhesive layer according to claim 1, characterized in that the mass ratio of component (B) to the sum of components (A) and (A') is in the range of 1.4 to 3.0, the pressure-sensitive adhesive layer obtained by curing the composition has a shear storage modulus G' at 25°C of 1.0 MPa to 20 MPa and a stress at 500% strain at 25°C of 0.20 MPa to 3 MPa, and the adhesive strength of a 50 µm-thick pressure-sensitive adhesive layer obtained by curing the composition to a 2 mm-thick polymethyl methacrylate sheet is 1300 gf / inch to 3500 gf / inch, as measured using a 180° peel test method in accordance with JIS Z 0237 at a tensile speed of 300 mm / min.

10. A pressure-sensitive adhesive layer obtained by curing the organopolysiloxane composition for forming a pressure-sensitive adhesive layer according to any one of claims 1 to 9.

11. A laminate comprising a film-like substrate and a pressure-sensitive adhesive layer formed by curing the organopolysiloxane composition capable of forming a pressure-sensitive adhesive layer according to any one of claims 1 to 9.

12. 12. The laminate of claim 11, wherein one or more film-like substrates are provided with a release layer for the pressure-sensitive adhesive layer.

13. 10. An elastic adhesive member obtained by curing the pressure-sensitive adhesive layer-forming organopolysiloxane composition according to any one of claims 1 to 9.

14. An electronic device or electrical device comprising the elastic adhesive member according to claim 13.

15. A speaker comprising the elastic adhesive member according to claim 13.

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