Method for producing silicone-modified polyimide resin

Abstract

The present invention aims to provide a method for producing a silicone-modified polyimide resin having a desired structure without using amide-based solvents. Furthermore, the present invention aims to provide a method for producing a silicone-modified polyimide resin that does not use amide-based solvents and that yields a uniform silicone-modified polyimide resin even when it contains a high amount of silicone moieties, and in particular, a method for producing a silicone-modified polyimide resin that yields a uniform silicone-modified polyimide resin even when it contains a high amount of long-chain silicone moieties. [Solution] A method for producing a silicone-modified polyimide resin, A method for producing polyamic acid, comprising the steps of: reacting (A) a tetracarboxylic dianhydride, (B) a linear organopolysiloxane having amino groups at both ends, and (C) an aromatic diamine compound in (D) a solvent without amide bonds to obtain a solution containing polyamic acid; and subjecting the polyamic acid to a dehydration ring-closing reaction to imidize it to obtain the silicone-modified polyimide resin, wherein the amount of component (D) is 3.5 times or more the total mass of components (A), (B), and (C), and 15 times or less the mass of component (B).

Description

[Technical Field]

[0001] This invention relates to a method for producing silicone-modified polyimide resin. [Background technology]

[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. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-180750 [Patent Document 2] Japanese Patent Publication No. 2000-169579 [Patent Document 3] Japanese Patent Application Publication No. 11-228826 [Patent Document 4] Japanese Patent Application Publication No. 10-182967 [Overview of the project] [Problems that the invention aims to solve]

[0005] Soluble polyimides with a siloxane skeleton (silicone-modified polyimides) have the advantage of not impairing the heat resistance of polyimides, but they have the problem of low compatibility with ordinary polyimide monomers, which limits the conditions such as solvents used during synthesis. In order to exhibit excellent properties derived from silicone, such as low elasticity and small temperature dependence of the elastic modulus, it is effective to introduce silicone with the longest possible chain length, but compatibility tends to decrease as the chain length increases. Therefore, it has been difficult to obtain a uniform silicone-modified polyimide resin with a high content of long-chain silicone moieties.

[0006] Furthermore, amide solvents such as N-methylpyrrolidone (NMP) and N,N-dimethylacetamide are commonly used in the synthesis of polyimide resins. Many of these are designated chemical substances, and synthesis using reaction solvents with higher safety is desirable whenever possible. Patent documents 3 and 4 describe the synthesis of silicone-modified polyimide resins using long-chain diaminosilicone, but in this method, the proportion of siloxane structures in the overall polymer is insufficient. In addition, the methods described in patent documents 3 and 4 use NMP as the reaction solvent during the production of silicone-modified polyimide resins, which presents a challenge in terms of safety and requires improvement.

[0007] The present invention was made to improve the above-mentioned problems and aims to provide a method for producing a silicone-modified polyimide resin having a desired structure without using amide-based solvents. Furthermore, the present invention aims to provide a method for producing a silicone-modified polyimide resin that does not use amide-based solvents and that provides a uniform silicone-modified polyimide resin even when it contains a high amount of silicone moieties, and in particular a method for producing a silicone-modified polyimide resin that provides a uniform silicone-modified polyimide resin even when it contains a high amount of long-chain silicone moieties. [Means for solving the problem]

[0008] As a result of diligent research to achieve the above objective, the inventors of the present invention have found that, in a method for producing silicone-modified polyimide resin, by keeping the amount of reaction solvent within a specific range, it is possible to uniformly and efficiently produce a silicone-modified polyimide resin having a desired structure without using an amide-based solvent. Furthermore, they have found that this method allows for the production of a uniform silicone-modified polyimide resin even when the content of long-chain silicone moieties is increased, leading to the present invention.

[0009] In other words, the present invention is [1] A method for producing a silicone-modified polyimide resin, The present invention provides a method for producing polyamic acid, comprising the steps of: reacting (A) a tetracarboxylic dianhydride, (B) a linear organopolysiloxane having amino groups at both ends, and (C) an aromatic diamine compound in (D) a solvent without amide bonds to obtain a solution containing polyamic acid; and subjecting the polyamic acid to a dehydration ring-closing reaction to imide it to obtain the silicone-modified polyimide resin, wherein the amount of component (D) is 3.5 times or more the total mass of components (A), (B), and (C), and 15 times or less the mass of component (B).

[0010] Furthermore, the present invention provides a method for producing a silicone-modified polyimide resin as shown in [2] and [3] below. [2] The component (B) is a both-end amino group-containing organopolysiloxane represented by the following formula (1). [Chemical formula] (In the formula, 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, and m is an integer of 30 to 90). The production method according to [1] above. [3] The tetravalent carboxylic dianhydride (A) is represented by the following formula (2). [Chemical formula] The production method according to [1] or [2] above.

[0011] Further, the present invention provides a method for producing a silicone-modified polyimide resin shown in [4] and [5] below. [4] The component (B) is a both-end amino group-containing organopolysiloxane represented by the following formula (3). [Chemical formula] (In the formula, R 1’ are each independently a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, R 2’ are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms without an aliphatic unsaturated bond, 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 production method according to [1] above. [5] The tetravalent carboxylic dianhydride (A) is represented by the following formula (2). [Chemical formula] The production method according to [4] above.

[0012] Furthermore, the manufacturing method of the present invention preferably further comprises at least one of the configurations shown in [6] to [8] below. [6] The manufacturing method according to any one of [1] to [5] above, wherein the amount of component (B) is 30 to 70% by mass relative to the total mass of components (A), (B), and (C). [7] The manufacturing method according to any one of [1] to [6] above, wherein the (D) component is one or more selected from cyclohexanone and cyclopentanone. [8] The manufacturing method according to any one of [1] to [7] above, wherein the amount of component (C) is such that the ratio of the molar amount of component (C) to the sum of the molar amounts of component (B) and component (C) is 30 to 90 mol%. [Effects of the Invention]

[0013] The manufacturing method of the present invention provides a uniform silicone-modified polyimide resin even when it contains a high amount of silicone, without the use of amide-based solvents. Furthermore, the manufacturing method of the present invention can provide a silicone-modified polyimide resin having long-chain silicone moieties, which is suitable for applications requiring flexibility and heat resistance. [Modes for carrying out the invention]

[0014] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0015] The present invention relates to a method for producing a silicone-modified polyimide resin, comprising the steps of: reacting (A) a tetracarboxylic dianhydride, (B) a linear organopolysiloxane having amino groups at both ends, and (C) an aromatic diamine compound in (D) a solvent without amide bonds to obtain a solution containing polyamic acid; and subjecting the polyamic acid to a dehydration ring-closing reaction to imide it to obtain the silicone-modified polyimide resin.

[0016] <(A) component> Component (A) of the present invention is a tetracarboxylic dianhydride. Preferably, it is a tetracarboxylic dianhydride having 4 to 30 carbon atoms, having an alicyclic aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may have an ether bond. In the production method of the present invention, the tetracarboxylic dianhydride may be any compound known in the production of polyimide resins. Examples include 4,4'-[propane-2,2-diyrbis(1,4-phenyleneoxy)]diphthalic acid dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-biphthalic acid anhydride, pyromellitic acid dianhydride, 4,4'-oxydiphthalic acid anhydride, etc. These may be used individually or in combination of two or more.

[0017] Component (A) of the present invention is preferably a tetracarboxylic dianhydride represented by the following formula (2) (4,4'-[propane-2,2-diyrbis(1,4-phenyleneoxy)]diphthalic acid dianhydride). [ka] 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic acid dianhydride exhibits excellent compatibility with organopolysiloxanes during the production of silicone-modified polyimide resins. Therefore, using the above-mentioned tetracarboxylic dianhydride is preferable because it allows for the maintenance of solvent solubility in the production of the silicone-modified polyimide resin and the resulting silicone-modified polyimide resin, even when the (B) organopolysiloxane described later has long-chain silicone moieties.

[0018] <(B) component> In the production method of the present invention, the component (B) is a linear organopolysiloxane having amino groups at both ends. The organopolysiloxane is preferably a linear organopolysiloxane having 1 to 95 siloxane units. According to the production method of the present invention, even when an organopolysiloxane having a long-chain silicone moiety with 30 or more siloxane units is used at a high content, a uniform silicone-modified polyimide resin can be provided.

[0019] One embodiment of the component (B) is an organopolysiloxane having amino groups at both ends represented by the following formula (1).

Chemical formula

[0020] In the above formula (1), R 1 is, independently of each other, a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms. The divalent hydrocarbon group may be linear, branched or cyclic, and examples include alkylene groups such as methylene group, ethylene group, methylmethylene group, trimethylene group, dimethylmethylene group, propylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group; cycloalkylene groups such as cyclopentylene, cyclohexylene group; alkenylene groups such as propenylene group; arylene groups such as phenylene, methylphenylene, naphthylene group; aralkylen groups such as benzylene, phenethylen group. Among these, ethylene group and trimethylene group are preferred.

[0021] In the above formula (1), R 2These are, independently of each other, substituted or unsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group 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; alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, pentenyl, and hexenyl 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, and bromine atoms, such as 3-chloropropyl and 3,3,3-trifluoropropyl groups. 2 Preferably, it is a group other than an aliphatic unsaturated hydrocarbon group, such as an alkenyl group. More 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.

[0022] In formula (1) above, m is an integer between 30 and 90, preferably between 40 and 80, and more preferably between 50 and 70. If m is below the lower limit, the resulting silicone-modified polyimide resin tends to be brittle. If m exceeds the upper limit, it is difficult to obtain a uniform silicone-modified polyimide resin. Component (B) above may be used alone or in combination of two or more.

[0023] Another embodiment of component (B) is an organopolysiloxane containing amino groups at both terminal ends, represented by the following formula (3). [ka] In equation (3), 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 3 These are, independently of each other, alkenyl groups having 2 to 10 carbon atoms, where m' is an integer from 0 to 20, and n' is an integer from 1 to 20, provided that m'+n' is less than 30.

[0024] In equation (3) above, R 1’ These 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.

[0025] In equation (3) above, R 2’ R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, independently of each other, which is substituted or unsubstituted and does not have an aliphatic unsaturated bond. Examples of such 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, for example, 3-chloropropyl and 3,3,3-trifluoropropyl groups. In formula (3) above, R 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.

[0026] In equation (3) above, R 3 These 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.

[0027] In formula (3) above, 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 resulting silicone-modified polyimide resin may be insufficient.

[0028] In formula (3) above, n' is an integer between 1 and 20, preferably between 4 and 10. If n' is 0, the adhesion between the resulting silicone-modified polyimide resin and the adherend may be insufficient. If n' exceeds the above upper limit, it may be difficult to obtain a uniform silicone-modified polyimide resin.

[0029] The proportion of organopolysiloxane structures in the resulting silicone-modified polyimide resin is preferably 30 to 70% by mass relative to the total mass of the resin. Silicone-modified polyimide resins having this range are preferred because they exhibit excellent solvent solubility and mechanical properties. In the manufacturing method of the present invention, the amount of component (B) is preferably such that the proportion of organopolysiloxane structures in the total resin is within the above range. Therefore, it is preferable that the amount is 30 to 70% by mass of the total mass of component (A), component (B), and component (C) described later. Furthermore, if component (B) is an organopolysiloxane represented by the above formula (1) and m is 30 to 90, the amount of component (B) is preferably 30 to 70% by mass, and more preferably 30 to 50% by mass, relative to the total mass of component (A), component (B), and component (C) described later. If component (B) is an organopolysiloxane represented by the above formula (3) and m'+n' is less than 30, the amount of component (B) is preferably 30 to 70% by mass, more preferably 40 to 70% by mass, and even more preferably 50 to 70% by mass, relative to the total mass of component (A), component (B), and component (C) described later.

[0030] <(C) component> Component (C) is an aromatic diamine. The structure of the aromatic diamine is not particularly limited and can be any known compound. Examples of aromatic diamines include phenylenediamine, benzidine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylsulfone, 9,9-bis(4-aminophenyl)fluorene, 1,1-bis(4-aminophenyl)cyclohexane, and 3,3'-dihydroxybenzidine. In addition, as hydroxyl group-containing aromatic diamines, for example, 2,2-bis(3-amino-4-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methane, bis(3-amino-4-hydroxyphenyl)ether, bis(3-amino-4-hydroxyphenyl)methanone, bis(3-amino-4-hydroxyphenyl)sulfone, 9,9-bis(3-amino-4-hydroxyphenyl)fluorene, 1,1-bis(3-amino-4-hydroxyphenyl)cyclohexane, etc. are also used. 2,2-bis[4-(4-aminophenoxy)phenyl]propane is particularly preferred. Component (C) can be used alone or in combination of two or more.

[0031] In the manufacturing method of the present invention, in order to obtain a silicone-modified polyimide resin with an appropriate molecular weight, it is preferable to carry out the reaction in a range where the ratio of the molar amount of component (A) / [molar amount of component (B) + molar amount of component (C)] is 0.9 to 1.1, more preferably in the range of 0.95 to 1.05, and even more preferably in the range of 0.98 to 1.02. Furthermore, considering the elastic modulus and solubility of the silicone-modified polyimide resin, the ratio of the molar amount of component (C) to the sum of the molar amounts of component (B) and component (C) is preferably 30 to 90 mol%. Furthermore, if component (B) is an organopolysiloxane represented by the above formula (1) and m is 30 or greater, the ratio of the molar amount of component (C) to the sum of the molar amounts of component (B) and component (C) is preferably 50 to 90 mol%, and more preferably 70 to 90 mol%. If component (B) is an organopolysiloxane represented by formula (3) above and m'+n' is less than 30, the ratio of the molar amount of component (C) to the sum of the molar amounts of component (B) and component (C) is preferably 30 to 70 mol%, and more preferably 30 to 50 mol%.

[0032] <(D) component> Component (D) is a solvent that does not have an amide bond. From the viewpoint of solubility and safety for each of the above components (A), (B), and (C), ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and acetylacetone are preferred, and cyclopentanone or cyclohexanone is particularly preferred.

[0033] In the manufacturing method of the present invention, the amount of component (D) is 3.5 times or more, preferably 4.0 times or more, more preferably 4.4 times or more, and 15 times or less, preferably 14.5 times or less, relative to the mass of component (B). If the amount of component (D) is less than the above range, it is not sufficient to dissolve components (A) to (C) and the silicone-modified polyimide resin after the reaction. If it exceeds the above range, the compatibility with component (B) deteriorates, and it may not be possible to obtain a uniform silicone-modified polyimide resin.

[0034] As described above, the method for producing the silicone-modified polyimide resin of the present invention includes the steps of: mixing (A) a tetracarboxylic dianhydride, (B) an organopolysiloxane containing amino groups at both ends, and (C) an aromatic diamine compound in (D) a solvent that does not have amide bonds to obtain a polyamic acid solution; and performing a dehydration and ring-closing reaction of the polyamic acid in the solution to imidize it and obtain a silicone-modified polyimide resin.

[0035] The steps of obtaining a polyamic acid solution and carrying out a dehydration and cyclization reaction to imide the solution can be carried out according to known methods. For example, known methods include reacting components (A) to (C) in component (D), raising the temperature of the resulting polyamic acid solution to 80 to 200°C to perform dehydration and cyclization (heat imidization), or reacting with a carboxylic acid anhydride and a tertiary amine to perform dehydration and cyclization (chemical imidization). The silicone-modified polyimide resin solution thus obtained can be added to a poor solvent such as water, methanol, ethanol, or acetonitrile, and the resulting precipitate can be dried to obtain a silicone-modified polyimide resin.

[0036] The weight-average molecular weight of the silicone-modified polyimide resin obtained by the manufacturing method of the present invention described above is preferably 10,000 to 100,000, and more preferably 15,000 to 70,000. If the weight-average molecular weight is above the lower limit, it is possible to suppress the brittleness of the obtained silicone-modified polyimide resin. If the weight-average molecular weight is below the upper limit, the silicone-modified polyimide resin is preferable because it has excellent solubility in solvents. Here, the weight-average molecular weight can be determined, for example, by gel permeation chromatography (GPC) using tetrahydrofuran as the mobile phase and expressed as polystyrene equivalent.

[0037] One preferred embodiment of the silicone-modified polyimide resin obtained by the manufacturing method of the present invention described above is a silicone-modified polyimide resin (1a) having constituent units represented by the following formulas (a) and (b), wherein X is an organopolysiloxane structure represented by the following formula (1'). Preferably, the proportion of the structure represented by X to the whole resin is 30 to 70% by mass. [ka] In (a) and (b) above, A is a tetracarboxylic acid bisimide structure represented by the following formula, [ka] (In the formula, R is a tetravalent group which may have an ether bond, and the wavy line represents a bond.) X is an organopolysiloxane structure represented by the following formula (1'): [ka] (In the formula, R 1 and R 2 The above equation (1) is as shown, where m is an integer between 30 and 90, and the lines with wavy lines represent connections. Z is a divalent hydrocarbon group having 1 to 50 carbon atoms, which may have an -O-, -S-, -NH-, -SO2-, or -CO- bond and may be substituted with a hydroxyl group.

[0038] In the above-mentioned silicone-modified polyimide resin (1a), preferably, Z in (b) is a divalent hydrocarbon group represented by the following formula. [ka] In the above formula, R 6 These are, independently of each other, single-bonded, substituted, or unsubstituted divalent hydrocarbon groups having 1 to 20 carbon atoms, -O-, -S-, -NH-, -SO2-, or -CO-, where p is an integer from 0 to 5. 5 These are, independently of each other, hydrogen atoms or hydroxyl groups. Lines with wavy lines represent bonding bonds.

[0039] In the above-mentioned silicone-modified polyimide resin (1a), preferably, A in (a) and (b) is a tetracarboxylic acid bisimide structure represented by the following formula. [ka] (In the equation, lines with a wavy line indicate a coupling.)

[0040] Another preferred embodiment of the silicone-modified polyimide obtained by the manufacturing method of the present invention is a silicone-modified polyimide resin (1b) having constituent units represented by the following formulas (a) and (b), wherein X is an organopolysiloxane structure represented by the following formula (3'). Preferably, the proportion of the structure represented by X to the whole resin is 40 to 70% by mass, more preferably 50 to 70% by mass. [ka] In (a) and (b) above, A is a tetracarboxylic acid bisimide structure represented by the following formula, [ka] (In the formula, R is a tetravalent group which may have an ether bond, and the wavy line represents a bond.) X is an organopolysiloxane structure represented by the following formula (3'), [ka] (In the formula, R 1’ , R 2’ , and R 3 The formula is as shown in equation (3) above, where m' is an integer between 0 and 20, n' is an integer between 1 and 20, and m'+n' is less than 30. The lines with wavy lines represent bonds, and the order of the siloxane units in parentheses is arbitrary. Z is a divalent hydrocarbon group having 1 to 50 carbon atoms, which may have an -O-, -S-, -NH-, -SO2-, or -CO- bond, and may be substituted with a hydroxyl group.

[0041] In the above-mentioned silicone-modified polyimide resin (1b), more preferably, Z in (b) is a divalent hydrocarbon group represented by the following formula. [ka] In the above formula, R 6 These are, independently of each other, single-bonded, substituted, or unsubstituted divalent hydrocarbon groups having 1 to 20 carbon atoms, -O-, -S-, -NH-, -SO2-, or -CO-, where p is an integer from 0 to 5. 5 These are, independently of each other, hydrogen atoms or hydroxyl groups. Lines with wavy lines represent bonding bonds.

[0042] In the above-mentioned silicone-modified polyimide resin (1b), preferably, A in (a) and (b) is a tetracarboxylic acid bisimide structure represented by the following formula. [ka] (In the equation, lines with a wavy line indicate a coupling.) [Examples]

[0043] 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.

[0044] [Example 1] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 28 g of 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic anhydride, 0.47 g of phthalic anhydride, 20 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 450 g of cyclohexanone were added and stirred at 25°C for 2 hours. Then, 31 g of organopolysiloxane containing amino groups at both ends, represented by the following formula (5), was added dropwise at 25°C. After the addition was complete, the mixture was stirred at 25°C for 12 hours. Next, 17 g of triethylamine and 17 g of acetic anhydride were added to the reaction vessel and stirred at 80°C for 4 hours to obtain a homogeneous reaction solution. The obtained reaction solution was added to methanol for reprecipitation, and the resulting solid was dried under reduced pressure to obtain a silicone-modified polyimide resin (weight-average molecular weight 41,900). The proportion of siloxane structures to the total resin was 39% by mass. [Parts of mass of component D] / [Total parts of mass of components A to C] = 5.7 [Parts by mass of component D] / [Parts by mass of component B] = 14.5 [ka]

[0045] [Example 2] In Example 1, the same procedure was followed except that the amount of cyclohexanone was changed to 350 g, and a homogeneous reaction solution was obtained. The obtained reaction solution was added to methanol and reprecipitation was performed, and the resulting solid was dried under reduced pressure to obtain a silicone-modified polyimide resin (weight-average molecular weight 42,700). The proportion of siloxane structures to the total resin was 39% by mass. [Parts of mass of component D] / [Total parts of mass of components A to C] = 4.4 [Parts by mass of component D] / [Parts by mass of component B] = 11.3

[0046] [Example 3] 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. Then, 82 g of organopolysiloxane containing amino groups at both ends, represented by the following formula (6), was added dropwise at 25°C. 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 stirred at 80°C for 4 hours to obtain a homogeneous reaction solution. The obtained reaction solution was added to methanol for reprecipitation, and the resulting solid was dissolved again in cyclohexanone. This was added back to methanol for reprecipitation, and the resulting solid was dried under reduced pressure to obtain a silicone-modified polyimide resin (weight-average molecular weight 25,800). The proportion of siloxane structures in the total resin was 60% by mass. [Parts of mass of component D] / [Total parts of mass of components A to C] = 3.7 [Parts by mass of component D] / [Parts by mass of component B] = 6.1 [ka] (In the formula, the order of the siloxane units in parentheses is undefined and they may be joined randomly.)

[0047] [Comparative Example 1] In Example 1, the same procedure as in Example 1 was performed except that the amount of cyclohexanone was changed to 200 g. However, when the organopolysiloxane containing amino groups at both ends, represented by formula (5) above, was added dropwise, significant turbidity occurred, and a uniform target product could not be obtained. [Parts of mass of component D] / [Total parts of mass of components A to C] = 2.5 [Parts of mass of component D] / [Parts of mass of component B] = 6.45

[0048] [Comparative Example 2] In Example 1, the same procedure as in Example 1 was performed except that the amount of cyclohexanone was changed to 555 g. However, when the organopolysiloxane containing amino groups at both ends, represented by formula (5) above, was added dropwise, significant turbidity occurred, and a uniform target product could not be obtained. [Parts of mass of component D] / [Total parts of mass of components A to C] = 7.03 [Parts of mass of component D] / [Parts of mass of component B] = 17.9

[0049] [Comparative Example 3] In a reaction vessel equipped with a stirrer, thermometer, and nitrogen inlet tube, 28 g of 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic anhydride, 0.47 g of phthalic anhydride, 20 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 400 g of cyclohexanone were placed and stirred at 25°C for 2 hours. Then, a mixture of 31 g of the organopolysiloxane containing amino groups at both ends represented by formula (5) and 80 g of cyclohexanone was added dropwise at 25°C. This resulted in significant turbidity, and a homogeneous target product could not be obtained. [Parts of mass of component D] / [Total parts of mass of components A to C] = 6.08 [Parts by mass of component D] / [Parts by mass of component B] = 15.5

[0050] [Comparative Example 4] In Example 1, the same procedure as in Example 1 was followed except that cyclohexanone was replaced with 500 g of N-methylpyrrolidone (NMP). However, when the organopolysiloxane containing amino groups at both ends, represented by formula (5) above, was added dropwise, significant turbidity occurred, and a homogeneous target product could not be obtained. [Mass portion of NMP] / [Total mass portion of components A to C] = 6.3 [Mass part of NMP] / [Mass part of component B]=16.1

[0051] As shown in the above examples and comparative examples, in the manufacturing method using a reaction solvent without amide bonds in an amount greater than or equal to a certain amount, the reaction solution does not become turbid, and a uniform target product is obtained. On the other hand, in the manufacturing method using a reaction solvent without amide bonds outside the scope of this application, the compatibility of the silicone component is poor, and a uniform silicone-modified polyimide resin cannot be obtained. The manufacturing method of the present invention is preferable because, even without using amide solvents, it is possible to obtain a silicone-modified polyimide resin that is as uniform as or better than that obtained using amide solvents and has a high siloxane content, while also ensuring safety.

Claims

1. A method for producing a silicone-modified polyimide resin, The manufacturing method comprises the steps of: reacting (A) a tetracarboxylic dianhydride, (B) a linear organopolysiloxane having amino groups at both ends, and (C) an aromatic diamine compound in (D) a solvent without amide bonds to obtain a solution containing polyamic acid; and subjecting the polyamic acid to a dehydration ring-closing reaction to imide to obtain the silicone-modified polyimide resin, wherein the amount of component (D) is 3.5 times or more the total mass of components (A), (B), and (C), and 15 times or less the mass of component (B).

2. The above component (B) is an organopolysiloxane containing amino groups at both terminal ends, represented by the following formula (1). 【Chemistry 1】 (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, and m is an integer from 30 to 90.) The manufacturing method according to claim 1.

3. The above (A) tetracarboxylic dianhydride is represented by the following formula (2), 【Chemistry 2】 The manufacturing method according to claim 2.

4. The above component (B) is an organopolysiloxane containing amino groups at both terminal ends, represented by the following formula (3). 【Transformation 3】 (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 ３ (Each is an independent alkenyl group having 2 to 10 carbon atoms, m' is an integer from 0 to 20, and n' is an integer from 1 to 20, provided that m' + n' is less than 30.) The manufacturing method according to claim 1.

5. The above (A) tetracarboxylic dianhydride is represented by the following formula (2), 【Chemistry 4】 The manufacturing method according to claim 4.

6. The manufacturing method according to any one of claims 1 to 5, wherein the amount of component (B) is 30 to 70% by mass relative to the total mass of components (A), (B), and (C).

7. The manufacturing method according to any one of claims 1 to 5, wherein the (D) component is one or more selected from cyclohexanone and cyclopentanone.

8. The manufacturing method according to any one of claims 1 to 5, wherein the amount of component (C) is such that the ratio of the molar amount of component (C) to the sum of the molar amounts of component (B) and component (C) is 30 to 90 mol%.

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