Silicone-modified polyimide resin, silicone-modified polyimide resin composition, and cured product

Abstract

[Problem] The present invention provides a silicone-modified polyimide resin composition having excellent adhesiveness to various substrates while maintaining solubility. [Solution] A silicone-modified polyimide resin having constituent units represented by formulas (1) and (2) [in formulas (1) and (2): A is a tetracarboxylic acid bisimide structure represented by formula (3) (in the formula, the lines having a wavy line thereon represent bonds); Z is a C1-C50 divalent hydrocarbon group that may have an -O-, -S-, -NH-, -SO2-, or -CO- bond; and X is an organopolysiloxane structure represented by formula (4) (in the formula, each R1 is independently a substituted or unsubstituted C1-C10 divalent hydrocarbon group, each R2 is independently a substituted or unsubstituted C1-C10 monovalent hydrocarbon group not having an aliphatic unsaturated bond, each R3 is independently a C2-C10 alkenyl group, m is an integer of 0-20 and n is an integer of 1-20 provided that m+n is less than 30, the lines having a wavy line thereon represent bonds, and the order of the siloxane units in the parentheses is arbitrary)].

Description

Silicone-modified polyimide resin, silicone-modified polyimide resin composition, and cured product

[0001] The present invention relates to a silicone-modified polyimide resin, a silicone-modified polyimide resin composition, and a cured product.

[0002] Generally, polyimide resins have high heat resistance and excellent electrical insulation properties, so they are used as materials for printed circuit boards and heat-resistant adhesive tapes. They are also used as resin varnishes for surface protection films and interlayer insulating films for electrical components and semiconductor materials. However, since polyimide resins are only soluble in a limited number of solvents, a common method involves coating a substrate with polyamic acid, a polyimide precursor that is relatively soluble in various organic solvents, and then obtaining a cured product made of polyimide resin by dehydration and cyclization through high-temperature treatment.

[0003] Polyimides present several process challenges, including the need to store them as unstable precursor polyamic acids and the requirement for high-temperature treatment of around 300°C during amidation. To overcome these challenges, various so-called soluble polyimides, which remain soluble in solvents even after imidation, have been developed (Patent Documents 1 and 2). While general polyimides use aromatic compounds with rigid skeletons as monomers, such as tetracarboxylic dianhydrides or diamines, soluble polyimides are characterized by the use of compounds with flexible skeletons as monomers. Known examples of such soluble polyimides include those using monomers with aliphatic skeletons with small intermolecular forces or monomers with siloxane skeletons.

[0004] Japanese Patent Publication No. 2015-180750, Japanese Patent Publication No. 2000-169579, Japanese Patent Publication No. 2009-060146, Japanese Patent Publication No. 2019-172889

[0005] However, while soluble polyimides with a siloxane skeleton (silicone-modified polyimides) have the advantage of not impairing the heat resistance of polyimides, they have problems such as low compatibility with ordinary polyimide monomers, which limits the conditions of the solvent used during synthesis, and the resulting polyimide resins tend to have insufficient adhesion to various substrates.

[0006] Furthermore, in recent years, delamination between the substrate and the epoxy resin encapsulant in semiconductor devices has been identified as a problem that impairs the reliability of the device (Patent Document 3). To prevent delamination, studies have been conducted on providing a flexible silicone-modified polyimide layer as a stress-relaxing layer between the substrate and the epoxy resin (Patent Document 4). However, in the applications described in Patent Documents 3 and 4, the lack of adhesion is a significant problem. To improve adhesion, it is conceivable to introduce monomers with strong intermolecular forces in addition to monomers with a siloxane skeleton. However, in such cases, problems arise such as a decrease in the solubility of the resulting polyimide, low compatibility with monomers with a siloxane skeleton, and partial precipitation during the imidation reaction, making it impossible to obtain a polymer with stable physical properties.

[0007] The present invention was made to improve upon the above-mentioned problems and provides a silicone-modified polyimide resin composition that maintains solubility while exhibiting excellent adhesion to various substrates.

[0008] As a result of diligent research to achieve the above objective, the inventors of the present invention discovered that by introducing a specific organic skeleton into the main chain of a silicone-modified polyimide resin, the adhesion to various substrates is significantly improved while maintaining solubility during and after imidation, leading to the present invention.

[0009] Accordingly, the present invention relates to [1] a silicone-modified polyimide resin having constituent units represented by the following formulas (1) and (2). [In equations (1) and (2), A is given by equation (3) below] (In the formula, the lines with wavy lines represent bonds) This is a tetracarboxylic bisimide structure represented by , where Z is -O-, -S-, -NH-, -SO ２ A divalent hydrocarbon group having 1 to 50 carbon atoms, which may have a - or -CO- bond, where X is the following formula (4) (In the formula, R １ These are independently substituted or unsubstituted divalent hydrocarbon groups having 1 to 10 carbon atoms, and R ２ These are, independently of each other, substituted or unsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms that do not have an aliphatic unsaturated bond, and R ３This is an organopolysiloxane structure represented as follows: (where m is an integer from 0 to 20, n is an integer from 1 to 20, where m + n is less than 30, the wavy lines represent bonds, and the order of the siloxane units in parentheses is arbitrary).

[0010] Furthermore, the present invention provides a silicone-modified polyimide resin, a silicone-modified polyimide composition, a laminate, a film, and a cured product having at least one of the following configurations: [2] The silicone-modified polyimide resin according to [1], wherein m is an integer from 4 to 15 and n is an integer from 4 to 10. [3] The silicone-modified polyimide resin according to [1] or [2], having a weight-average molecular weight of 10,000 to 100,000. [4] The silicone-modified polyimide resin according to any one of [1] to [3], wherein the mass percentage of the structure represented by X is 40 to 70% by mass of the total mass of the silicone-modified polyimide resin. [5] The silicone-modified polyimide resin according to any one of [1] to [4], wherein Z is a divalent hydrocarbon group represented by the following formula. (In formula (6), R ５ These are, independently of each other, single-bonded, substituted or unsubstituted divalent hydrocarbon groups having 1 to 20 carbon atoms, -O-, -S-, -NH-, -SO ２ - or -CO-, where p is an integer from 0 to 5, and the line with a wavy line represents a coupling) [6] The above Z is given by the following formula (5) A silicone-modified polyimide resin according to [5] above, wherein the divalent hydrocarbon group is represented by (in the formula, the line with a wavy line represents a bond). [7] A silicone-modified polyimide resin composition comprising (a) the silicone-modified polyimide resin according to any one of [1] to [6] above, and (b) a solvent in an amount of 100 to 700 parts by mass per 100 parts by mass of component (a). [8] A silicone-modified polyimide resin composition according to [7] above, wherein the solvent is at least one aproton polar solvent selected from ketone solvents, ether solvents, ester solvents, and amide solvents. [9] A silicone-modified polyimide resin composition according to [8] above, wherein the solvent is propylene glycol monomethyl ether acetate.

[10] A silicone-modified polyimide resin composition according to any one of [7] to [9] above, further comprising (c) a curing agent in an amount of 0.1 to 10 parts by mass per 100 parts by mass of component (a).

[11] The silicone-modified polyimide resin composition according to

[10] , wherein the curing agent (c) is a thermal radical initiator.

[12] A laminate comprising a substrate and a resin layer formed from the silicone-modified polyimide resin composition according to any one of [7] to

[11] .

[13] A film formed from the silicone-modified polyimide resin composition according to any one of [7] to

[11] .

[14] A cured product of the silicone-modified polyimide resin composition according to any one of [7] to

[11] .

[0011] The silicone-modified polyimide resin of the present invention is soluble in solvents, has low elasticity, and exhibits excellent adhesion to various substrates, making it suitable for use as a primer, adhesive, and coating agent to prevent delamination between the substrate and encapsulant in semiconductor devices.

[0012] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0013] The present invention relates to a silicone-modified polyimide resin having constituent units represented by the following formulas (1) and (2). In formulas (1) and (2), A is a tetracarboxylic acid bisimide structure represented by the following formula (3), and is a structure formed by the reaction of a tetracarboxylic dianhydride and a diamine compound. (In the formula, the wavy line represents a bond) The tetracarboxylic acid bisimide structure in the present invention is formed by the reaction of 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride and a diamine compound. 4,4'-[Propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride is excellent in compatibility with organopolysiloxane during the production of silicone-modified polyimide resins. Further, by having the above structure, a silicone-modified polyimide resin excellent in solubility in solvents and adhesion to substrates can be obtained.

[0014] In the above formula (1), X is an organopolysiloxane structure represented by the following formula (4). This structure is derived from an organopolysiloxane having amino groups at both ends. In formula (4), R １ is, independently of each other, a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, and R ２ is, independently of each other, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms without an aliphatic unsaturated bond, and R ３ is, independently of each other, an alkenyl group having 2 to 10 carbon atoms, m is an integer of 0 to 20, n is an integer of 1 to 20, and the wavy line represents a bond. The sequence order of the siloxane units in the parentheses is arbitrary. It is preferable that m + n is less than 30.

[0015] In the above formula (4), R １These are independently substituted or unsubstituted divalent hydrocarbon groups having 1 to 10 carbon atoms. The divalent hydrocarbon groups may be linear, branched, or cyclic, and examples include alkylene groups such as methylene, ethylene, methylmethylene, trimethylene, dimethylmethylene, propylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, and decamethylene; cycloalkylene groups such as cyclopentylene and cyclohexylene; alkenylene groups such as propenylene; arylene groups such as phenylene, methylphenylene, and naphthylene; and aralkylene groups such as benzylene and phenethylene. Among these, ethylene and trimethylene groups are preferred.

[0016] In the above formula (4), R ２ These are, independently of each other, substituted or unsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms that do not have aliphatic unsaturated bonds. Examples of these monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; aryl groups such as phenyl, tolyl, xylyl, and α-,β-naphthyl groups; aralkyl groups such as benzyl, 2-phenylethyl, and 3-phenylpropyl groups; and alkyl groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, chlorine, or bromine atoms, such as 3-chloropropyl and 3,3,3-trifluoropropyl groups. ２ The group is a group other than an aliphatic unsaturated hydrocarbon group such as an alkenyl group. Preferably, it is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, or a propyl group, or an aryl group such as a phenyl group, with a methyl group being particularly preferred.

[0017] In the above formula (4), R ３These are, independently of each other, alkenyl groups having 2 to 10 carbon atoms. Examples of such alkenyl groups include vinyl, allyl, propenyl, isopropenyl, butenyl, dimethylallyl, pentenyl, and hexenyl groups, with vinyl being preferred.

[0018] m is an integer between 0 and 20, preferably between 4 and 15. If m exceeds the above upper limit, the mechanical properties of the silicone-modified polyimide resin may become insufficient.

[0019] n is an integer between 1 and 20, preferably between 4 and 10. If n is 0, the adhesion between the silicone-modified polyimide resin and the adherend will be insufficient. If n exceeds the above upper limit, it will be difficult to obtain a uniform silicone-modified polyimide resin.

[0020] An organopolysiloxane containing amino groups at both ends that gives the organopolysiloxane structure represented by X above can be represented, for example, by the following formula (4'). (In the formula, R １ , R ２ , R ３ m and n are as described above. (The order of the siloxane units in parentheses is arbitrary.)

[0021] In the silicone-modified polyimide resin of the present invention, the proportion of the organopolysiloxane structure represented by X is preferably 40 to 70% by mass, and more preferably 50 to 70% by mass, relative to the total mass of the resin. Silicone-modified polyimide resins having such a range are preferable because they exhibit excellent solubility in solvents and mechanical properties.

[0022] In equation (2) above, Z is -O-, -S-, -NH-, -SO ２ The structure is a divalent hydrocarbon group, preferably having 1 to 50 carbon atoms, which may have a - or -CO- bond, and is derived from a diamine compound. Examples of diamine compounds include aromatic diamines and aliphatic diamines, but from the viewpoint of the solubility of the silicone-modified polyimide resin in solvents and adhesion to the substrate, a structure derived from an aromatic diamine is preferred.

[0023] Examples of the aromatic diamine that provides such a structure include phenylenediamine, benzidine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl methane, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl sulfone, 9,9-bis(4-aminophenyl)fluorene, 1,1-bis(4-aminophenyl)cyclohexane, 3,3'-dihydroxybenzidine, etc. Among these, 2,2-bis[4-(4-aminophenoxy)phenyl]propane is particularly preferred.

[0024] Z is preferably a divalent structure represented by the following formula. In the formula, R ５ are, independently of each other, a single bond, a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms, -O-, -S-, -NH-, -SO ２ -, or -CO-. p is an integer of 0 to 5, preferably 1 to 3. The wavy line represents a bond. The bonding position of R ５ is not particularly limited.

[0025] Examples of Z include a divalent group represented by the following formula, etc.

[0026] Z is particularly preferably a structure represented by the following formula (5). (In the formula, the wavy line represents a bond)

[0027] In order to adjust the molecular weight of the resulting silicone-modified polyimide resin, the silicone-modified polyimide resin of the present invention may contain, as a terminal structure, a structural unit derived from a dicarboxylic acid anhydride such as maleic anhydride or phthalic anhydride, or a structural unit derived from a monoamine such as aniline or butylamine. Further, considering the solubility of the silicone-modified polyimide resin in a solvent and the adhesiveness to an adherend, the proportion of X is preferably 30 to 90 mol%, more preferably 30 to 70 mol%, based on the total number of moles of X and Z.

[0028] The weight average molecular weight of the silicone-modified polyimide resin of the present invention is preferably from 10,000 to 100,000, more preferably from 15,000 to 70,000. When the weight average molecular weight is at least the above lower limit, the silicone-modified polyimide resin has excellent mechanical properties. When the weight average molecular weight is at most the above upper limit, the silicone-modified polyimide resin has excellent solubility in solvents. Here, the weight average molecular weight can be determined as a polystyrene equivalent amount by, for example, gel permeation chromatography (GPC) using tetrahydrofuran as a mobile phase.

[0029] The silicone-modified polyimide resin of the present invention can be obtained, for example, by a production method including a step of mixing 4,4'-[propane-2,2-diybis(1,4-phenyleneoxy)]diphthalic dianhydride, a linear organopolysiloxane having amino groups at both ends represented by the above formula (4'), and the above diamine compound in a solvent to obtain a polyamic acid solution, and a step of subjecting the solution to a dehydration ring-closure reaction to effect imidization to obtain a silicone-modified polyimide resin.

[0030] From the viewpoints of solubility and safety with respect to each of the raw material tetracarboxylic dianhydride, organopolysiloxane and diamine compound, the reaction solvent is preferably a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, acetylacetone, etc., and particularly preferably cyclopentanone and cyclohexanone.

[0031] The step of effecting a dehydration ring-closure reaction to effect imidization may be carried out according to a known method. For example, a method of heating the obtained polyamic acid solution to preferably 80 to 200°C, more preferably 140 to 180°C to effect dehydration cyclization (thermal imidization), or a method of allowing a carboxylic anhydride and a tertiary amine to act thereon to effect dehydration cyclization (chemical imidization) is known. The silicone-modified polyimide resin can be obtained by adding the thus obtained silicone-modified polyimide resin solution to a poor solvent such as water, methanol, ethanol, acetonitrile, etc. and drying the obtained precipitate.

[0032] The present invention further provides a silicone-modified polyimide resin composition comprising (a) the silicone-modified polyimide resin and (b) a solvent. The silicone-modified polyimide resin of the present invention can be provided as a varnish by dissolving it in a solvent. When the silicone-modified polyimide resin composition is used as a primer, coating agent, film, etc., the solvent is usually removed by heating or other means after coating by any method.

[0033] (b) As the solvent, a non-protic polar solvent is preferred from the viewpoint of solubility of polyimide resin. For example, at least one non-protic polar solvent selected from ketone solvents, ether solvents, ester solvents, and amide solvents. More specifically, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and acetylacetone; ether solvents such as dioxane, dioxolane, tetrahydrofuran, 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, 1,2-bis(methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl] ether, methyl-t-butyl ether, and dipropylene glycol dimethyl ether; butyl acetate, isobutyl acetate, amyl acetate, γ-valerolactone, and propylene glycol monomethyl ether acetate. Examples of suitable solvents include ester-based solvents such as tate, 3-methoxybutyl acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, cyclohexanol acetate, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, and 1,6-hexanediol diacetate, as well as amide-based solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-methylcaprolactam, and 1,3-dimethyl-2-imidazolidinone. These can be used individually or in combination of two or more. Among these, propylene glycol monomethyl ether acetate, cyclohexanone, and cyclopentanone are particularly preferred.

[0034] (b) The amount of solvent can be used in a range that does not impair the solubility of component (a), but preferably 100 to 700 parts by mass, more preferably 150 to 500 parts by mass, and even more preferably 200 to 400 parts by mass per 100 parts by mass of component (a).

[0035] The silicone-modified polyimide resin composition of the present invention may optionally contain a curing agent as component (c). The curing agent is preferably a thermal radical initiator. Examples of thermal radical initiators include azo compounds and organic peroxides, with organic peroxides being particularly preferred.

[0036] Organic peroxides include hydroperoxides such as cumene hydroperoxide, t-butyl hydroperoxide, t-amyl hydroperoxide, and diisopropylbenzene hydroperoxide; dialkyl peroxides such as dicumyl peroxide, t-butylcumyl peroxide, and di(t-butyl peroxide); peroxyesters such as cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-amyl peroxyneodecanoate, t-butyl peroxypivalate, and t-butyl peroxy-2-ethylhexanoate; diisobutyryl peroxide, dilauroyl peroxide, and diisopropylbenzene hydroperoxide. Diacyl peroxide derivatives such as dibenzoyl peroxide, peroxide derivatives such as diisopropyl peroxydicarbonate, dicetyl peroxydicarbonate, t-amyl peroxyisopropyl carbonate, t-butyl peroxyisopropyl carbonate, t-butyl peroxy-2-ethylhexyl carbonate, and 1,6-bis(t-butyl peroxycarbonyloxy)hexane can be used. Peroxyketal derivatives such as 1,1-di(t-butyl peroxy)cyclohexane and 2,2-di(t-amyl peroxy)butane, and ketone peroxide derivatives such as methyl ethyl ketone peroxide and acetylacetone peroxide can also be used. Dibenzoyl peroxide derivatives or 1,6-bis(t-butyl peroxycarbonyloxy)hexane are preferred because they are less susceptible to inhibition by oxygen during curing of thin films.

[0037] (c) The amount of component (c) is preferably 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of component (a), from the viewpoint of curability and the mechanical properties of the resulting cured product.

[0038] The silicone-modified polyimide resin composition of the present invention may contain other components in addition to the components (a) to (c) described above, as long as they do not impair the purpose of the present invention. Examples of other components include adhesion promoters, thixotropic promoters, dispersants, colorants, heat resistance enhancers, and flame retardant enhancers.

[0039] The method for producing the silicone-modified polyimide resin composition of the present invention is not particularly limited, and known production methods can be employed. For example, the composition can be produced by mixing the above components (a) to (c) simultaneously or separately, and stirring, dissolving, and mixing them while adding heat treatment as necessary.

[0040] The present invention further provides a laminate comprising a substrate and a resin layer formed from the silicone-modified polyimide resin composition of the present invention. The type of substrate is not particularly limited, but examples include metals such as iron, copper, nickel, and aluminum; inorganic materials such as glass; and organic resins such as epoxy resins, acrylic resins, polycarbonate resins, polyethylene terephthalate resins, and liquid crystal polyester resins. For example, a wire bar, comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, gravure coater, screen coating, dipping coating, cast coating, etc. A film can be formed by heating and drying the silicone-modified polyimide resin composition of the present invention. The heating temperature and time are not particularly limited, but may be 50 to 150°C for 1 to 5 hours. The film thickness is not particularly limited, but is preferably 10 to 2000 μm, and more preferably 100 to 1000 μm.

[0041] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In these examples, weight-average molecular weight was measured using a GPC instrument HLC-8320GPC manufactured by Tosoh Corporation, with tetrahydrofuran (THF) as the mobile phase, and measured in polystyrene equivalent. For infrared absorption (IR) spectroscopy, a NICOLET 6700 (manufactured by Thermo Fisher Scientific K.K.) was used.

[0042] [Example 1-1] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 41 g of 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic anhydride, 0.75 g of phthalic anhydride, 12.5 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 500 g of cyclohexanone were placed and stirred at 25°C for 2 hours, followed by the following formula (7) 82 g of organopolysiloxane containing amino groups at both ends, represented by the formula (wherein the formula the order of siloxane units in parentheses is undefined and may be randomly bonded), was added dropwise at 25°C, and after the addition was complete, the mixture was stirred at 25°C for 12 hours. Next, 30 g of triethylamine and 30 g of acetic anhydride were added to the reaction vessel, and the mixture was stirred at 80°C for 4 hours. The resulting reaction solution was added to methanol for reprecipitation, and the resulting solid was dissolved again in cyclohexanone. This was added to methanol again for reprecipitation, and the resulting solid was dried under reduced pressure to obtain silicone-modified polyimide resin (a-1).

[0043] In Example 1-1, the silicone-modified polyimide resin (a-1) showed no absorption based on unreacted polyamic acid in the IR spectrum, and at 1,780 cm⁻¹, the absorption was not observed. －１ and 1,720 cm －１ Absorption of imide groups was confirmed. The silicone-modified polyimide resin (a-1) is presumed to be a silicone-modified polyimide resin consisting of the following repeating units a and b, with a weight-average molecular weight of 25,800, and the proportion of the structure represented by X below to the total mass of the silicone-modified polyimide resin was 60% by mass. In the above structure, A is given by the following formula (8): Z is given by the following equation (9): X is given by the following equation (10). The order in which the units [A-X] and [A-Z] enclosed by a and b above are combined is not limited to what is described above.

[0044] In the comparative example, the 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic anhydride used in Example 1-1 above was replaced with the following comparative acid anhydrides 1 to 4 to produce a silicone-modified polyimide resin. Comparative acid anhydride 1: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride Comparative acid anhydride 2: 3,3',4,4'-benzophenonetetracarboxylic dianhydride Comparative acid anhydride 3: 4,4'-biphthalic anhydride Comparative acid anhydride 4: 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2c]furan-1,3-dione Details are explained below.

[0045] [Comparative Example 1-1] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 44 g of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 0.67 g of phthalic anhydride, 14.4 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 500 g of cyclohexanone were placed and stirred at 25°C for 2 hours. Then, 107 g of organopolysiloxane containing amino groups at both ends, represented by the above formula (7), was added dropwise at 25°C. After the dropwise addition was complete, the mixture was stirred at 25°C for 12 hours. Next, 30 g of triethylamine and 30 g of acetic anhydride were added to the reaction vessel and stirred at 80°C for 4 hours. The resulting reaction solution was added to methanol for reprecipitation, and the obtained solid was dissolved again in cyclohexanone. This was added to methanol again for reprecipitation, and the obtained solid was dried under reduced pressure to obtain a silicone-modified polyimide resin (a-2).

[0046] In Comparative Example 1-1, the silicone-modified polyimide resin (a-2) showed no absorption based on unreacted polyamic acid in the IR spectrum, and at 1,780 cm⁻¹ －１ and 1,720 cm －１ Absorption of imide groups was confirmed. The silicone-modified polyimide resin (a-2) is presumed to be a silicone-modified polyimide resin consisting of the above repeating units a and b, where Z is formula (9) above, X is formula (10) above, and A is a structure derived from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride. The weight-average molecular weight was 24,700, and the proportion of the structure represented by X above was 65% by mass of the total mass of the silicone-modified polyimide resin.

[0047] [Comparative Example 1-2] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 40 g of 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1.18 g of phthalic anhydride, 27 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 500 g of cyclohexanone were placed and stirred at 25°C for 2 hours. Then, 102 g of organopolysiloxane containing amino groups at both ends, represented by the above formula (7), was added dropwise at 25°C. After the dropwise addition was complete, the mixture was stirred at 25°C for 12 hours to obtain the intermediate polyamic acid. Next, 30 g of triethylamine and 30 g of acetic anhydride were added to the reaction vessel and heated to 80°C. After 1 hour, the mixture became a gel insoluble in the solvent, and a homogeneous target product could not be obtained.

[0048] [Comparative Example 1-3] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 40 g of 4,4'-biphthalic anhydride, 1.29 g of phthalic anhydride, 30 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 500 g of cyclohexanone were placed and stirred at 25°C for more than 2 hours. After adding another 500 g of cyclohexanone and stirring for 12 hours, insoluble matter remained while new precipitates were formed, and a homogeneous target product could not be obtained.

[0049] [Comparative Example 1-4] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 30 g of 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2c]furan-1,3-dione, 3 g of phthalic anhydride, 82 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 500 g of cyclohexanone were placed and stirred at 25°C for 2 hours, and the following formula (11) was obtained. 78 g of organopolysiloxane containing amino groups at both ends, represented by (in the formula, the order of the siloxane units in parentheses is undefined and may be randomly bonded), was added dropwise at 25°C, and after the addition was complete, the mixture was stirred at 25°C for 12 hours. Next, 30 g of triethylamine and 30 g of acetic anhydride were added to the reaction vessel and the mixture was stirred at 80°C for 4 hours. The resulting reaction solution was added to methanol for reprecipitation, and the resulting solid was dissolved again in cyclohexanone. This was added to methanol again for reprecipitation, and the resulting solid was dried under reduced pressure to obtain silicone-modified polyimide resin (a-3). In the IR spectrum of the silicone-modified polyimide resin (a-3) obtained in Comparative Example 1-4, no absorption based on unreacted polyamic acid was observed at 1,780 cm⁻¹. －１ and 1,720 cm －１ Absorption of an imide group was confirmed. The silicone-modified polyimide resin (a-3) is presumed to be a silicone-modified polyimide resin consisting of the above repeating units a and b, where Z is formula (9), X is a group derived from formula (11), and A is a structure derived from 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2c]furan-1,3-dione. The weight-average molecular weight was 18,500, and the proportion of the structure represented by X was 41% by mass of the total mass of the silicone-modified polyimide resin.

[0050] The silicone-modified polyimide resins obtained in Evaluation Example 1-1 and Comparative Examples 1-1 and 1-4 were mixed with the following components in the blending ratios (parts by mass) shown in Table 1 to prepare silicone-modified polyimide resin compositions. The physical properties of each obtained silicone-modified polyimide resin composition were measured according to the method described below. The results are shown in Table 1.

[0051] A silicone-modified polyimide resin composition was applied to a metal plate coated with polytetrafluoroethylene using a spacer to achieve a coating thickness of 700 μm, and dried on a hot plate at 50°C for 30 minutes. This was then heated at 100°C for 30 minutes and then at 150°C for 1 hour to produce a film.

[0052] [Tensile Strength, Elongation at Break] A 700 μm thick film obtained by the above method was cut into a dumbbell-shaped No. 5 form as specified in JIS K6251:2023, and used as a test specimen. A tensile test was performed on the test specimen using an Autograph AG-1kNplus manufactured by Shimadzu Corporation at a speed of 20 mm / min, and the tensile strength and elongation at break were measured.

[0053] [Storage Modulus] A 700 μm thick film obtained by the above method was cut into strips measuring 10 mm x 40 mm to form test specimens. The storage modulus of these test specimens was measured at a frequency of 1 Hz under conditions of 25°C using a viscoelasticity measuring device DMS-7100 manufactured by Hitachi High-Tech Science Co., Ltd.

[0054] [Adhesion] Aluminum plates, copper plates, and epoxy resin plates were used as substrates. A silicone-modified polyimide resin composition was applied to each surface using spacers to achieve a coating thickness of 200 μm, and dried on a hot plate at 50°C for 30 minutes. This was then heated at 100°C for 30 minutes and at 150°C for 1 hour to obtain a laminate having a silicone-modified polyimide resin layer on the substrate. An incision was made in the silicone-modified polyimide resin layer of the laminate with a razor blade, and the state when pulled by hand in a 90° direction was evaluated according to the following index. Delamination occurred at the interface between the substrate and the silicone-modified polyimide resin layer: C (Poor) Cohesive failure occurred in part or all of the silicone-modified polyimide resin layer: B (Acceptable) No delamination occurred at all: A (Good)

[0055] The components listed in Table 1 are as follows: (a) Silicone-modified polyimide resin (a-1): Silicone-modified polyimide resin obtained in Example 1-1 (a-2): Silicone-modified polyimide resin obtained in Comparative Example 1-1 (a-3): Silicone-modified polyimide resin obtained in Comparative Example 1-4

[0056] (b) Solvent (b-1): Propylene glycol monomethyl ether acetate

[0057] (c) Curing agent (c-1): 70% by mass solution of 1,6-bis(t-butylperoxycarbonyloxy)hexane with tributyl O-acetylcitrate (c-2): Niper® BMT-K40 (manufactured by NOF Corporation)

[0058]

[0059] As shown in Table 1, the silicone-modified polyimide resin having the tetracarboxylic acid bisimide structure (A) of the present invention obtained in Example 1-1 was soluble in solvents, and the resin layer formed from the silicone-modified polyimide resin composition obtained therefrom exhibited excellent adhesion to various substrates (Examples 2-1 to 2-3). On the other hand, the silicone-modified polyimide resin of Comparative Example 1-1, in which the tetracarboxylic acid bisimide structure (A) of the polyimide resin of the present invention was changed to a structure derived from comparative acid anhydride 1, and the silicone-modified polyimide resin of Comparative Example 1-4, in which the structure was changed to a structure derived from comparative acid anhydride 4, were soluble in solvents, but the films obtained from the compositions of Comparative Examples 2-1 to 2-4 using these exhibited poor adhesion to various metals.

[0060] As described above, the silicone-modified polyimide resin of the present invention is soluble in solvents, has low elasticity, and exhibits excellent adhesion to various substrates. Therefore, it is suitable for use in applications such as primers, adhesives, and coatings to prevent delamination between substrates and encapsulants in semiconductor devices.

Claims

1. A silicone-modified polyimide resin having structural units represented by the following formulas (1) and (2) [In formulas (1) and (2), A is a tetracarboxylic bisimide structure represented by the following formula (3) (where the wavy line represents a bond), and Z is a divalent hydrocarbon group having 1 to 50 carbon atoms which may have a -O-, -S-, -NH-, -SO ２ - or -CO- bond, and X is the following formula (4) (wherein R １ are each independently a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, and R ２ are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms without an aliphatic unsaturated bond, and R ３ are each independently an alkenyl group having 2 to 10 carbon atoms, m is an integer of 0 to 20, n is an integer of 1 to 20, provided that m + n is less than 30, the wavy line represents a bond, and the arrangement order of the siloxane units in parentheses is arbitrary), which is an organopolysiloxane structure].

2. The silicone-modified polyimide resin according to claim 1, wherein m is an integer from 4 to 15 and n is an integer from 4 to 10.

3. The silicone-modified polyimide resin according to claim 1, having a weight-average molecular weight of 10,000 to 100,000.

4. The silicone-modified polyimide resin according to claim 1, wherein the mass percentage of the structure represented by X is 40 to 70% by mass of the total mass of the silicone-modified polyimide resin.

5. The above Z is given by the following equation (6) (In formula (6), R ５ These are, independently of each other, single-bonded, substituted or unsubstituted divalent hydrocarbon groups having 1 to 20 carbon atoms, -O-, -S-, -NH-, -SO ２ The silicone-modified polyimide resin according to claim 1, wherein the divalent hydrocarbon group is represented as - or -CO-, where p is an integer from 0 to 5, and the wavy line represents a bond.

6. The above Z is given by the following equation (5) The silicone-modified polyimide resin according to claim 5, wherein the divalent hydrocarbon group is represented by (wherein the formula, the line with a wavy line represents a bond).

7. A silicone-modified polyimide resin composition comprising (a) a silicone-modified polyimide resin according to any one of claims 1 to 6, and (b) a solvent in an amount of 100 to 700 parts by mass per 100 parts by mass of component (a).

8. The silicone-modified polyimide resin composition according to claim 7, wherein the solvent is at least one aprotic polar solvent selected from ketone solvents, ether solvents, ester solvents, and amide solvents.

9. The silicone-modified polyimide resin composition according to claim 8, wherein the solvent is propylene glycol monomethyl ether acetate.

10. (c) The silicone-modified polyimide resin composition according to claim 7, further comprising a curing agent in an amount of 0.1 to 10 parts by mass per 100 parts by mass of component (a).

11. The silicone-modified polyimide resin composition according to claim 10, wherein the curing agent (c) is a thermal radical initiator.

12. A laminate comprising a base material and a resin layer formed from a silicone-modified polyimide resin composition according to any one of claims 7 to 11.

13. A film formed from the silicone-modified polyimide resin composition according to any one of claims 7 to 11.

14. A cured product of a silicone-modified polyimide resin composition according to any one of claims 7 to 11.

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