Primer Composition

Abstract

This primer composition comprises: (A) an acrylic acid ester, a methacrylic acid ester, or a (co)polymer of these esters; (B) an organosilicon compound represented by formula (1), an organosilicon compound represented by formula (2), or both (R1 and R2 are each an alkyl group, R3 is a divalent hydrocarbon group, R4 is an alkylene group or a carbonyl group, R5 is a monovalent hydrocarbon group, a is 0 or 1, and b is an integer of 0-3); (C) at least one condensation catalyst selected from among tetraalkoxy titanium, tetraalkoxy zirconium, tetraalkoxy tin, trialkoxy aluminum, and partial hydrolysates thereof; and (D) a solvent.

Description

[Technical field]

[0001] The present invention relates to a primer composition, and more specifically to a primer composition that imparts adhesion between an adherend such as a polyimide resin and a cured silicone product. [Background technology]

[0002] Silicone rubber has excellent heat resistance, cold resistance, light resistance, electrical insulation, etc., and has conventionally been used as an adhesive sealant, electrical insulation material, potting material, etc. In this case, when the adhesive strength of the silicone rubber to the substrate is insufficient, it is common practice to treat the substrate with a primer in advance.

[0003] Known primer compositions for cured products of addition-curing silicone compositions used in adhesive sealants, electrical insulating materials, potting materials, etc. include compositions comprising silane coupling agents and / or their reaction products, polyester resins, and acrylic resins, and compositions comprising phenyl-containing siloxanes, alkyl silicates, and chlorosilanes.

[0004] In recent years, polyimide resins have been used in various applications as high-performance materials with excellent mechanical strength, heat resistance, electrical insulation, and the like. The applications are diverse, and examples include flexible printed circuits. When a substrate is converted to a polyimide resin with excellent heat resistance, materials with excellent heat resistance are also required for the peripheral materials. For this reason, it is expected that the use of silicone materials in polyimide components will increase. However, in general, silicone cured products are difficult to adhere to polyimide resins, and a method for improving adhesion to polyimide resins is required. Prior art documents related to the present invention include the following: [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-19909 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a primer composition that is capable of firmly adhering an adherend such as a polyimide resin to a cured silicone product. [Means for solving the problem]

[0007] As a result of intensive research aimed at achieving the above-mentioned object, the inventors have discovered that a composition containing a (meth)acrylic acid ester (co)polymer and an organosilicon compound having a specific functional group introduced therein is capable of firmly adhering an adherend such as a polyimide resin to a silicone cured product, and have completed the present invention.

[0008] That is, the present invention provides 1. (A) an acrylic acid ester, a methacrylic acid ester, or a (co)polymer of both of these; (B) an organosilicon compound represented by the following formula (1), an organosilicon compound represented by the following formula (2), or both of these: [ka] (In the formula, R 1 and R 2 are each independently an alkyl group having 1 to 4 carbon atoms, and R 3 are each independently a divalent hydrocarbon group having 1 to 30 carbon atoms, and R 4 are each independently an alkylene group having 1 to 6 carbon atoms or a carbonyl group, R 5 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, a is each independently 0 or 1, and b is an integer from 0 to 3. (C) one or more condensation catalysts selected from tetraalkoxytitanium, tetraalkoxyzirconium, tetraalkoxytin, trialkoxyaluminum, and partial hydrolysates thereof; (D) Solvent and A primer composition comprising 2. The primer composition according to 1, wherein the acrylic acid ester, the methacrylic acid ester, or both of them constituting the component (A) contain a compound having one or more SiH groups in one molecule. 3. The component (B) contains an organosilicon compound represented by the above formula (1), and R 4 is a carbonyl group. 4. The primer composition according to any one of 1 to 3, further comprising (E) an organosilicon compound represented by the following formula (3): (R 6 O) c R 7 d Si (3) (In the formula, R 6 are each independently an alkyl group having 1 to 4 carbon atoms, and R 7 are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, an acrylic group, a methacrylic group, or an epoxy group, c is an integer of 1 to 4, d is an integer of 0 to 3, and c+d=4. 5. A step of supplying the primer composition according to any one of 1 to 4 onto an adherend; placing a curable silicone composition on the adherend to which the primer composition has been applied, and curing the silicone composition; A method for bonding an adherend to a silicone cured product, 6. The bonding method according to 5, wherein the adherend is a polyimide resin. to provide. Effect of the Invention

[0009] The primer composition of the present invention is capable of firmly bonding an adherend such as a polyimide resin to a cured silicone product, and is particularly useful as an adhesive for semiconductor devices which require high reliability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be specifically described below. The primer composition according to the present invention contains (A) a (meth)acrylic acid ester (co)polymer, (B) an organosilicon compound, (C) a condensation catalyst, and (D) a solvent.

[0011] (1)(A) Component The component (A) is an acrylic acid ester, a methacrylic acid ester, or a (co)polymer of both of these. Such a primer composition containing component (A) forms a flexible film on the adherend and forms a bond through an addition reaction with the addition-curable silicone composition. As the (meth)acrylic acid ester constituting the component (A), a (meth)acrylic acid alkyl ester having an alkyl group with 1 to 12 carbon atoms, particularly 1 to 4 carbon atoms, is preferred.

[0012] Examples of acrylic acid esters include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, isopentyl acrylate, n-hexyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isononyl acrylate, n-decyl acrylate, and isodecyl acrylate.

[0013] Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, isopentyl methacrylate, n-hexyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, isononyl methacrylate, n-decyl methacrylate, and isodecyl methacrylate.

[0014] The (meth)acrylic acid ester constituting the component (A) preferably has one or more SiH groups in one molecule. Examples of the (meth)acrylic acid ester having one or more SiH groups in one molecule include compounds represented by the following formulas (4) to (6).

[0015] [ka]

[0016] R 8 are each independently a hydrogen atom or a methyl group. R 9 are each independently a monovalent organic group. 9 The monovalent organic group is preferably an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, particularly 1 to 3 carbon atoms. Examples of the monovalent hydrocarbon group include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, pentyl, neopentyl, hexyl, and octyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl (2-propenyl), and 1-propenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, bromine, and chlorine, or cyano groups, for example, chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl. 9 As the alkyl group, a methyl group, an ethyl group, and a phenyl group are preferable, and a methyl group is particularly preferable.

[0017] R 10 are each independently a divalent organic group. 10 The divalent organic group is preferably an unsubstituted or substituted divalent hydrocarbon group having 1 to 10 carbon atoms, particularly 1 to 3 carbon atoms. Examples of the divalent hydrocarbon group include linear or branched alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, and octamethylene; cycloalkylene groups such as cyclohexylene; and arylene groups such as phenylene and naphthylene. In addition, some or all of the hydrogen atoms of these groups may be substituted with halogen atoms such as fluorine, bromine, and chlorine, or with a cyano group, for example, tetrafluoroethylene, hexafluoropropylene, etc. 10As the alkyl group, a methylene group, an ethylene group, or a trimethylene group is preferable, and a trimethylene group is particularly preferable.

[0018] n is 0, 1 or 2. m is 0 or a positive integer, and p is a positive integer. q and r are positive integers. In formulas (5) and (6), the arrangement of the siloxane units in parentheses may be arbitrary. These (meth)acrylic acid esters may be used alone or in combination of two or more. The component (A) preferably contains a compound represented by formula (4), and it is particularly preferable to use other acrylic acid esters and / or methacrylic acid esters in combination with the compound represented by formula (4). In this case, the ratio of the other acrylic acid ester and / or methacrylic acid ester to the compound represented by formula (4) is not particularly limited, but the molar ratio of the other acrylic acid ester and / or methacrylic acid ester:the compound represented by formula (4) is preferably 1:1 to 20:1, more preferably 1:1 to 15:1, and even more preferably 1:1 to 10:1.

[0019] Examples of the compound represented by formula (4) include the following. [ka]

[0020] Examples of the compound represented by formula (5) include the following. [ka] (In the formula, m and p are the same as above. The arrangement of the siloxane units in parentheses may be arbitrary.)

[0021] Examples of the compound represented by formula (6) include the following. [ka] (In the formula, q and r are the same as above. The arrangement of the siloxane units may be arbitrary.)

[0022] As described below, the component (A) can be obtained by polymerizing a (meth)acrylic acid ester using a radical polymerization initiator such as 2,2'-azobisisobutyronitrile (AIBN). The weight average molecular weight of the component (A) is not particularly limited, but is preferably from 100 to 500,000, and more preferably from 10,000 to 200,000. In the present invention, the weight average molecular weight is a value calculated using standard polystyrene by gel permeation chromatography (GPC).

[0023] The amount of component (A) blended is not particularly limited as long as it is an amount that dissolves in component (D) described below, but is preferably 0.1 to 20 mass % of the total composition, more preferably 0.1 to 10 mass %, and even more preferably 0.5 to 5 mass %. Within such a range, the occurrence of unevenness on the surface of the resulting film can be prevented, and sufficient performance as a primer composition can be obtained.

[0024] (2)(B) Component The component (B) is an organosilicon compound represented by the following formula (1), an organosilicon compound represented by the following formula (2), or both of these.

[0025] [ka]

[0026] R 1 and R 2 are each independently an alkyl group having 1 to 4 carbon atoms. 1 and R 2 Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl and t-butyl, with a methyl group and an ethyl group being preferred.

[0027] R 3are each independently a divalent hydrocarbon group having 1 to 30 carbon atoms. 3 Examples of the divalent hydrocarbon group represented by the formula (I) include linear or branched alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, and octamethylene; cycloalkylene groups such as cyclohexylene; and arylene groups such as phenylene and naphthylene. Those having 3 to 8 carbon atoms are preferred, and a trimethylene group is more preferred.

[0028] R 4 are each independently an alkylene group having 1 to 6 carbon atoms or a carbonyl group. 4 Examples of the alkylene group having 1 to 6 carbon atoms include linear or branched alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene; cycloalkylene groups such as cyclohexylene; and arylene groups such as phenylene. 4 As the alkyl group, a carbonyl group is preferable.

[0029] R 5 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms. 5 Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, pentyl, neopentyl, hexyl, and octyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, and propenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, bromine, and chlorine, or with cyano groups, for example, chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl. 5 As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is particularly preferable, and a methyl group, an ethyl group, an n-propyl group, or a butyl group is even more preferable.

[0030] Each a is independently 0 or 1, and preferably 0. b is an integer of 0 to 3, and preferably 0. The component (B) may be used alone or in combination of two or more. The component (B) preferably contains a compound represented by formula (1), R 4 However, a carbonyl group is more preferred.

[0031] Examples of the compound represented by formula (1) include the following. [ka]

[0032] Examples of the compound represented by formula (2) include the following. [ka]

[0033] The blending amount of component (B) is preferably 0.1 to 20 mass % of the total composition, more preferably 0.1 to 10 mass %, and even more preferably 0.5 to 5 mass %. Within such a range, the occurrence of unevenness on the surface of the obtained film can be prevented, and sufficient performance as a primer composition can be obtained.

[0034] (3)(C) component The condensation catalyst of component (C) is one or more condensation catalysts selected from the group consisting of tetraalkoxytitanium, tetraalkoxyzirconium, tetraalkoxytin, trialkoxyaluminum, and partial hydrolysates thereof, and promotes the condensation reaction of the alkoxysilyl groups of component (B). The alkoxy group of component (C) is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, and t-butoxy.

[0035] Examples of tetraalkoxytitanium include tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, and tetra-n-butoxytitanium, with tetra-n-butoxytitanium being particularly preferred. Examples of tetraalkoxyzirconium include tetramethoxyzirconium, tetraethoxyzirconium, tetra-n-propoxyzirconium, tetraisopropoxyzirconium, and tetra-n-butoxyzirconium, with tetra-n-butoxyzirconium being particularly preferred. Examples of tetraalkoxytin include tetramethoxytin, tetraethoxytin, tetra-n-propoxytin, tetraisopropoxytin, tetra-n-butoxytin, and tetra-t-butoxytin, with tetra-t-butoxytin being particularly preferred. Examples of trialkoxyaluminum include aluminum(III) ethoxide, aluminum(III) isopropoxide, aluminum(III)-s-butoxide, aluminum(III)-n-butoxide, and mono-s-butoxyaluminum diisopropylate, with aluminum(III)-n-butoxide and mono-s-butoxyaluminum diisopropylate being preferred. These may be used alone or in combination of two or more.

[0036] The blending amount of the component (C) is preferably 1 to 300 parts by mass, and more preferably 20 to 250 parts by mass, per 100 parts by mass of the component (B). If the blending amount is within this range, a coating film having excellent strength can be obtained.

[0037] (4)(D) Component The solvent for component (D) is not particularly limited as long as it dissolves the above components (A), (B), and (C) and the optional components described below, and any known organic solvent can be used. Examples of the solvent include aromatic hydrocarbon solvents such as xylene, toluene, and benzene; aliphatic hydrocarbon solvents such as heptane, hexane, and ligroin; halogenated hydrocarbon solvents such as trichloroethylene, perchloroethylene, and methylene chloride; ester solvents such as ethyl acetate and 1-propylene glycol methyl ether acetate; ether solvents such as tetrahydrofuran and diethyl ether; ketone solvents such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; alcohol solvents such as ethanol, isopropanol, and butanol; rubber volatile oil, silicone solvents, etc. Among these, ethyl acetate, 1-propylene glycol methyl ether acetate, tetrahydrofuran, and acetone are preferably used.

[0038] The component (D) may be used alone or in combination of two or more types as a mixed solvent, depending on the evaporation rate during application of the primer composition.

[0039] By blending the (D) component, the workability during application and drying of the primer composition can be adjusted. The blending amount of the (D) component is not particularly limited, but is preferably 60% by mass or more of the total primer composition, more preferably 80 to 95% by mass, and even more preferably 85 to 90% by mass. If it is within such a range, the coating film of the primer composition can be formed uniformly, and unevenness of the coating film surface can be suppressed. Note that, when the (A) component and the like are added as a solution, the blending amount of the (D) component indicates the total amount in the composition including the solvent in the solution.

[0040] (5)(E) Component The primer composition of the present invention may further contain, as component (E), an organosilicon compound represented by the following formula (3). (R 6 O) c R 7 d Si (3)

[0041] R 6 are each independently an alkyl group having 1 to 4 carbon atoms.6 Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl and t-butyl, with a methyl group and an ethyl group being preferred. R 7 R are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, an acrylic group, a methacrylic group, or an epoxy group. 7 As the monovalent hydrocarbon group having 1 to 10 carbon atoms, R 9 Examples of the monovalent hydrocarbon group include the same as those exemplified above, and a methyl group and a phenyl group are preferred. c is an integer of 1 to 4, and preferably 3 or 4; d is an integer of 0 to 3, and preferably 0 or 1; and c+d=4.

[0042] Examples of the component (E) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, etc. Among these, tetramethoxysilane and tetraethoxysilane are particularly preferred.

[0043] When component (E) is used, its amount is not particularly limited, but is preferably 1 to 20 mass %, and more preferably 2 to 10 mass %, of the total composition.

[0044] [Other ingredients] The primer composition of the present invention may further contain other optional components such as fluorescent materials, reinforcing fillers, dyes, pigments, heat resistance improvers, antioxidants, adhesion promoters, etc., within the scope of not impairing the object of the present invention.

[0045] [Method of manufacturing primer composition] The primer composition of the present invention can be obtained, for example, by a method in which the above-mentioned components (A), (B), (C) and (D), as well as, if necessary, component (E) and other optional components, are uniformly mixed using a mixer.

[0046] [Adhesion method] The primer composition of the present invention can be suitably used to improve the adhesion between an adherend and a silicone cured product.As a method for adhering an adherend and a silicone cured product using the primer composition of the present invention, for example, a method of supplying the primer composition of the present invention onto an adherend, disposing a curable silicone composition on the adherend to which the primer composition has been supplied, and curing the silicone composition can be adopted.

[0047] The primer composition of the present invention can be applied onto an adherend by a known method such as brush coating, spray coating, etc. After applying the primer composition onto the adherend, it may be air-dried for 5 minutes to 24 hours, preferably 10 minutes to 12 hours, and then a curable silicone composition may be applied and the silicone composition may be cured at room temperature (25°C) or under heat to bond the adherend and the silicone cured product, or the composition may be air-dried, heated to harden the coating, and then the curable silicone composition may be applied, and the adherend and the silicone cured product may be bonded in the same manner as above.

[0048] The adherend used in the present invention includes organic resins such as acrylic resin, phenol resin, epoxy resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, polyimide resin, polypropylene resin, various metals, glass, etc., among which polyimide resin is particularly preferred. Examples of polyimide resins include HJA-A4-100 (manufactured by Kitashin Co., Ltd.), Kapton 100H, Kapton 100EN (all manufactured by Toray Industries, Inc.), etc.

[0049] Examples of the curable silicone composition include addition curing type, peroxide curing type, and condensation curing type, but in the present invention, addition curing type silicone rubber composition is preferred.As the addition curing type silicone rubber composition, a known one can be used, and usually, one containing an organopolysiloxane having two or more alkenyl groups such as vinyl groups in one molecule, an organohydrogenpolysiloxane having two or more SiH groups in one molecule, and an addition reaction catalyst such as a platinum group metal catalyst can be used.As the addition curing type silicone rubber composition, for example, KE-106, KER-2600 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. can be mentioned. EXAMPLES

[0050] The present invention will be specifically described below using Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to these.

[0051] [Synthesis Example 1] 40 parts by mass of methyl methacrylate, 14 parts by mass of a SiH group-containing methacrylic acid ester represented by the following structural formula (7), 230 parts by mass of ethyl acetate, and 0.25 parts by mass of AIBN were heated and stirred at 90°C for 6 hours to obtain an ethyl acetate solution containing a copolymer and having a nonvolatile content of 8% by mass (value at 105°C for 3 hours). The weight average molecular weight of the obtained copolymer was 95,000 in terms of standard polystyrene, measured by using GPC (HLC-8320GPC, manufactured by Tosoh Corporation) with tetrahydrofuran as a developing solvent.

[0052] [ka]

[0053] [Examples 1-1 to 1-7, Comparative Examples 1-1 and 1-2] Primer compositions (I) to (VII) and comparative primer compositions (VIII) and (IX) were prepared by mixing the following components in the amounts shown in Table 1. The values ​​in Table 1 represent parts by mass.

[0054] (A): 8% by mass ethyl acetate solution of the copolymer obtained in Synthesis Example 1

[0055] (B1): 3-ureidopropyltrimethoxysilane (KBM-585, manufactured by Shin-Etsu Chemical Co., Ltd.) [ka]

[0056] (B2): 3-aminopropyltriethoxysilane (KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) [ka]

[0057] (B3): 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine (KBE-9103P, manufactured by Shin-Etsu Chemical Co., Ltd.) [ka]

[0058] (C): Tetra-n-butoxytitanium (D): Ethyl acetate (E): Tetraethoxysilane

[0059] [Table 1]

[0060] [Examples 2-1 to 2-7, Comparative Examples 2-1 and 2-2] The primer compositions (I) to (VII) and comparative primer compositions (VIII) and (IX) obtained in Examples 1-1 to 1-7 and Comparative Examples 1-1 and 1-2 were evaluated for adhesion by the following adhesion test. The results are shown in Table 2.

[0061] [Comparative Example 2-3] The addition curable silicone primer composition (X) (PRIMER NO4 (carbon functional silane primer), manufactured by Shin-Etsu Chemical Co., Ltd.) was used as is to evaluate the adhesion by the following adhesion test. The results are shown in Table 2.

[0062] [Comparative Example 2-4] Except for not using a primer composition, the adhesion was evaluated by the adhesion test described below. The results are shown in Table 2.

[0063] [Adhesion test] Three types of polyimide sheets (HJA-A4-100, manufactured by Hokushin Co., Ltd.; Kapton 100H, manufactured by Toray Industries, Inc.; and Kapton 100EN, manufactured by Toray Industries, Inc.) cut to 30 mm x 30 mm were used as adherends, and the primer composition was brushed onto the adherends and air-dried at 25° C. for 15 minutes. An addition-curing silicone composition (KE-106, manufactured by Shin-Etsu Chemical Co., Ltd.) was dripped onto the adherends and cured to produce a laminated sheet. The resultant laminate sheet was cut near the center of the cured silicone product on the laminate sheet with a cutter knife, and the state of the cured silicone product when the laminate sheet was folded was checked. The results were rated as follows: × if the cured silicone product peeled off when the laminate sheet was folded, △ if the cured silicone product did not peel off when the laminate sheet was folded but peeled off entirely when an attempt was made to peel it off by hand, and ◯ if the cured silicone product did not peel off when the laminate sheet was folded and cohesive failure occurred when an attempt was made to peel it off by hand.

[0064] [Table 2]

[0065] As shown in Table 2, Examples 2-1 to 2-7 show significantly improved adhesion of the addition-cured silicone cured product to the polyimide sheet compared to Comparative Examples 2-1 to 2-3, in which a primer composition different from the primer composition of the present invention was used, and Comparative Example 2-4, in which no primer composition was used.

Claims

1. A primer composition which is supplied onto an adherend to bond the adherend to a cured product of the curable silicone composition when the curable silicone composition is placed on the adherend and cured, comprising: (A) an acrylic acid ester, a methacrylic acid ester, or a (co)polymer of both of these, (B) an organosilicon compound represented by the following formula (1), an organosilicon compound represented by the following formula (2), or both of these: 【Chemistry 1】 (In the formula, R 1 and R 2 are each independently an alkyl group having 1 to 4 carbon atoms; R 3 are each independently a divalent hydrocarbon group having 1 to 30 carbon atoms; R 4 are each independently an alkylene group having 1 to 6 carbon atoms or a carbonyl group, R 5 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, a is each independently 0 or 1, and b is an integer from 0 to 3. (C) one or more condensation catalysts selected from tetraalkoxytitanium, tetraalkoxyzirconium, tetraalkoxytin, trialkoxyaluminum, and partial hydrolysates thereof; (D) a solvent; wherein the acrylic acid ester, methacrylic acid ester, or both of these constituting component (A) contain a compound having one or more SiH groups per molecule.

2. 2. The primer composition according to claim 1, wherein the acrylic acid ester, the methacrylic acid ester, or both of them constituting the component (A) include one or more compounds selected from the compounds represented by the following formulas (4) to (6): 【Chemistry 2】 (In the formulae, R 8 are each independently a hydrogen atom or a methyl group, R 9 are each independently a monovalent organic group, and R 10 are each independently a divalent organic group. n is 0, 1 or 2. m is 0 or a positive integer, p is a positive integer, and q and r are positive integers. In formulae (5) and (6), the arrangement of the siloxane units in parentheses may be arbitrary.)

3. The component (B) contains an organosilicon compound represented by the above formula (1), and R 4 3. The primer composition according to claim 1, wherein is a carbonyl group.

4. The primer composition according to any one of claims 1 to 3, further comprising (E) an organosilicon compound represented by the following formula (3): (R) 6 O) c R 7 d Yes (3) (In the formula, R 6 are each independently an alkyl group having 1 to 4 carbon atoms; R 7 are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, an acrylic group, a methacrylic group, or an epoxy group, c is an integer of 1 to 4, d is an integer of 0 to 3, and c+d=4.

5. A primer composition according to any one of claims 1 to 4, wherein the adherend is a polyimide resin.

6. A primer composition according to any one of claims 1 to 5, wherein the curable silicone composition is an addition-curable silicone composition.

7. A step of supplying the primer composition according to any one of claims 1 to 6 onto an adherend; placing a curable silicone composition on the adherend to which the primer composition has been applied, and curing the silicone composition; The present invention relates to a method for bonding an adherend having the above structure to a cured silicone product.

8. 8. The bonding method according to claim 7, wherein the adherend is made of a polyimide resin.

9. The bonding method according to claim 7 or 8, wherein the curable silicone composition is an addition-curable silicone composition.

10. A laminate comprising an adherend and a cured layer of a curable silicone composition formed on the adherend via a coating of the primer composition according to any one of claims 1 to 6.

11. The laminate according to claim 10, wherein the adherend is a polyimide resin.

12. The laminate according to claim 10 or 11, wherein the curable silicone composition is an addition-curable silicone composition.

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