JP2012001701A - Method for producing polyimide resin, and polyimide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyimide resin having desired properties, and to provide the polyimide resin.SOLUTION: The polyimide is produced by carrying out blocking operation to form different kind polymers (terminal-activated polymer A and terminal-activated polymer B) while leaving terminal activation groups, and polymerizing both polymers. Since the chains of the different polymers are chemically bonded by the method, the separation of the solution (liquid separation) can be prevented. Since each of the different polymers has a high molecular weight, a proper phase separation structure is developed in the case of forming a film to prevent averaging of the characteristic features of both polymers and exhibit excellent properties.

Description

  The present invention relates to a method for producing a polyimide resin comprising a block polyimide resin copolymer, and a polyimide resin.

  Polyimide resin (PI) is applied to various electronic devices because of its high elastic modulus, relatively low thermal expansion coefficient, high heat resistance, insulation, and chemical resistance (solvent resistance). It is widely used as a base film material for copper-clad laminates for Flexible Printed Circuits) and as a coverlay (protective film) for the purpose of protecting conductive circuits (for example, see Patent Document 1).

  The FPC is used for a thin and compact part such as around the LCD (Liquid Crystal Display) of a mobile phone, and is bent when assembled. If the FPC has high resilience, it is difficult to incorporate the FPC when it is incorporated into the housing, so a considerable amount of material that can give flexibility to the main chain of the polyimide resin (such as a siloxane skeleton) is incorporated, and low elasticity To reduce the repulsive force.

  The coverlay is classified into a film type and an ink type depending on the state of the cover material. In the FPC manufacturing method, the film type is used by laminating or pressing, and the ink type is used by a wet method such as screen printing or gravure printing. As the ink type polyimide resin, there is known a solvent-soluble polyimide resin that incorporates a material capable of imparting flexibility to the main chain of the polyimide resin and completes imidization in a solvent (such as γ-butyrolactone) used for printing. It has been.

As described above, since a polymer material such as a polyimide resin is required to have characteristics suitable for the application, it is necessary to control the characteristics of the polymer itself. By the way, generally, the following means are known as a method for controlling the characteristics of a polymer.
Change the chemical composition of the polymer. ... Methods for controlling the primary structure of polymers such as random copolymerization and alternating copolymerization.
Control the chain orientation of the polymer film. ... Method of controlling secondary structure of polymer by means such as stretching or controlling higher order structure such as crystallization.
• Blend two or more polymers. ... So-called polymer blends.
• Blend additives (other than polymers) to the polymer. ... So-called composite and hybrid technology (eg glass epoxy).

  Here, the above-mentioned polymer blend may have properties superior to those obtained by changing (copolymerizing) the chemical composition of the polymer. For example, a film obtained by blending both a high hardness but a fragile homopolymer and a homopolymer having a high flexibility but a low hardness may be able to make use of the advantages by making up for each other's drawbacks.

JP 2003-155343 A

  However, when the polymer blend has poor compatibility between the polymers, desired characteristics cannot be obtained. For example, even if an attempt is made to blend a very different polymer such as a blend of a siloxane polyimide resin and a general aromatic polyimide resin, film formation is difficult due to vigorous phase separation because it is a completely incompatible system. .

  This invention is proposed in view of such a conventional situation, and provides the manufacturing method of the polyimide resin which can obtain a desired characteristic, and a polyimide resin.

  As a result of intensive studies, the inventors of the present invention have different properties, that is, when a different type of polyimide resin is used to obtain desired characteristics, the terminal active group forms a different type of polyimide resin segment (polyimide resin chain). As a result, it was found that when these terminal active groups are chemically bonded, the resulting polyimide resin can be controlled so that the characteristics of each segment can be expressed.

  That is, in the method for producing a polyimide resin according to the present invention, at least one acid dianhydride selected from general formulas (1) to (3) is reacted with an aromatic diamine represented by general formula (4). , Synthesizing at least one hard segment having a first active terminal group consisting of an acid anhydride group or an amino group, and at least one acid dianhydride selected from the general formulas (1) to (3); By reacting with the diaminosiloxane represented by the formula (5), at least one soft segment having a second active terminal group comprising an acid anhydride group or an amino group is synthesized, and at least one having the first active terminal group is synthesized. A kind of hard segment and at least one kind of soft segment having the second active terminal group are imidized.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｘは、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、又はアルコキシ基で置換されていてもよい。）

(Wherein R ₁ and R ₂ are each independently absent or represent hydrogen, methyl group, trifluoromethyl group, and X is C═O, SO ₂ , S, O, C, or directly And each benzene ring may be substituted with a halogen, an alkyl group, or an alkoxy group.)

（式中、Ｒ_１〜Ｒ_６は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｙ_１、Ｙ_２及びＺは、それぞれ独立に、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、ヒドロキシル基、又はアルコキシ基で置換されていてもよい。また、ｍは、０又は１である。）

(Wherein R _{1 to} R ₆ each independently does not exist or represents hydrogen, a methyl group, or a trifluoromethyl group, and Y ₁ , Y _2, and Z each independently represent C═O, SO ₂ , S, O, C, or a direct bond, and each benzene ring may be substituted with a halogen, an alkyl group, a hydroxyl group, or an alkoxy group, and m is 0 or 1. .)

（式中、Ｒ_１及びＲ_８は、それぞれ独立に、存在しないか、又は炭素数１〜４のアルキレン基、若しくはフェニレン基を示し、それらは置換基を有していてもよい。また、Ｒ_２〜Ｒ_７は、それぞれ独立に、炭素数１以上の炭化水素、脂肪族、又は芳香族から選ばれる１価の有機基を示す。また、ｎは１以上の整数である。）

(In the formula, R ₁ and R ₈ each independently represents an alkylene group having 1 to 4 carbon atoms or a phenylene group, which may have a substituent. _{2 to} R ₇ each independently represents a monovalent organic group selected from a hydrocarbon having 1 or more carbon atoms, an aliphatic group, or an aromatic group, and n is an integer of 1 or more.

  In addition, the polyimide resin according to the present invention is obtained by the manufacturing method described above.

  According to this invention, since the characteristic of a polyimide resin is controllable, the outstanding characteristic can be expressed.

It is a figure for demonstrating the blend of a different polymer. It is a figure for demonstrating random copolymerization. It is a figure for demonstrating the superposition | polymerization method in this Embodiment. It is a GPC chart of the polyimide resin of Examples 1-3 and Comparative Example 2. It is a graph which shows the DMA curve (a) of Example 3, and the DMA curve (b) of the comparative example 3. 2 is a metal micrograph of the film of Example 1. 2 is a SEM photograph of the film of Example 1. 2 is a schematic diagram of a phase separation structure of the film of Example 1. FIG. 2 is a metal micrograph of the film of Example 2. 3 is a SEM photograph of the film of Example 2. 2 is a metal micrograph of the film of Example 2. It is a schematic diagram which shows the test pattern of screen printing.

Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings.
1. 1. Outline of the present invention Specific Example 3 Example

<1. Summary of the present invention>
One important factor in the method for producing the polyimide resin (PI) in the present embodiment is the compatibility between different types of polymers. In general, factors that determine the compatibility of polymers include the following.
・ Chemical structure (Similar solubility parameters are compatible with each other.)
・ Molecular weight (Small molecular weights are compatible with each other.)
・ Molecular chain mobility (for example, viscosity, temperature, stirring conditions, etc., because the molecular chain movement is affected, so compatibility can be controlled.)
・ Compatibilizer (for example, surfactant)

  In a so-called polymer blend in which different types of polymers are blended, it is difficult to form a film by vigorous phase separation when the chemical structures are different. For example, a blend of a siloxane polyimide resin (polymer A) and a general aromatic polyimide resin (polymer B) having extremely different properties as shown in FIG. Processing (film formation) becomes difficult. In such a case, as shown in FIG. 2, if the monomers A and B are randomly copolymerized, a uniform solution is obtained, but the respective characteristics are averaged.

  In addition, by incorporating a similar chemical structure into the blending partner, compatibility may be improved and film formability may be improved. However, since the properties of the polymer are simply averaged as in the case of a random copolymer and the film properties of the blend are similar, there is a possibility that the initially expected effect may not be exhibited.

  In addition, when the molecular weight is reduced, the compatibility can be easily controlled, but the entanglement of the polymer chain may be reduced to deteriorate the film characteristics. In addition, means for freezing the movement of polymer chains so that they are not mixed and separated by vigorous physical agitation (for example, thickening at low temperatures, instantaneous solvent volatilization after mixing, etc.) Difficult due to equipment constraints and difficulty in ensuring stable quality. In addition, the compatibilizing agent has low heat resistance of the substance itself, so that the heat resistance of the polymer itself may be reduced, and problems such as bleeding out may occur.

  Therefore, in this embodiment, the degree of polymerization of the block copolymerization method, particularly the A component and the B component, is increased in advance, leaving the respective terminal activities, and finally AB is chemically bonded. Specifically, as shown in FIG. 3, a block operation is performed in which different polymers (terminal active polymer A and terminal active polymer B) are formed while the terminal active groups remain, and both polymers are polymerized. Thereby, since different polymer chains are chemically bonded, separation of the solution (liquid separation) can be prevented. Further, since each of the different polymers has a high molecular weight, when formed into a film, an appropriate phase separation structure develops, the characteristics of both are not averaged, and excellent characteristics are exhibited.

<3. Specific example>
The method for producing a polyimide resin in the present embodiment can be applied to a completely incompatible system represented by a blend of a siloxane polyimide resin and a general aromatic polyimide resin as described above.

  Since the siloxane polyimide resin has high flexibility, high elongation, and low elastic modulus due to its siloxane skeleton, it can be said that such a siloxane polyimide resin has a soft segment. On the other hand, since the aromatic polyimide resin is derived from the aromatic ring and has a high elastic modulus and excellent flame retardancy, it can be said that such an aromatic polyimide resin has a hard segment. Of course, these characteristics are difficult to achieve in a single polyimide resin due to a trade-off relationship, but according to the method for manufacturing a polyimide resin in the present embodiment, these characteristics can be controlled.

  That is, in the method for producing a polyimide resin in the present embodiment, at least one acid dianhydride selected from general formulas (1) to (3) is reacted with an aromatic diamine represented by general formula (4). And synthesizing at least one hard segment having a first active terminal group consisting of an acid anhydride group or an amino group, and at least one acid dianhydride selected from general formulas (1) to (3); Reaction with the diaminosiloxane represented by the general formula (5) to synthesize at least one soft segment having a second active terminal group consisting of an acid anhydride group or an amino group, and having at least the first active terminal group One hard segment and at least one soft segment having a second active terminal group are imidized.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｘは、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、又はアルコキシ基で置換されていてもよい。）

(Wherein R ₁ and R ₂ are each independently absent or represent hydrogen, methyl group, trifluoromethyl group, and X is C═O, SO ₂ , S, O, C, or directly And each benzene ring may be substituted with a halogen, an alkyl group, or an alkoxy group.)

（式中、Ｒ_１〜Ｒ_６は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｙ_１、Ｙ_２及びＺは、それぞれ独立に、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、ヒドロキシル基、又はアルコキシ基で置換されていてもよい。また、ｍは、０又は１である。）

(Wherein R _{1 to} R ₆ each independently does not exist or represents hydrogen, a methyl group, or a trifluoromethyl group, and Y ₁ , Y _2, and Z each independently represent C═O, SO ₂ , S, O, C, or a direct bond, and each benzene ring may be substituted with a halogen, an alkyl group, a hydroxyl group, or an alkoxy group, and m is 0 or 1. .)

（式中、Ｒ_１及びＲ_８は、それぞれ独立に、存在しないか、又は炭素数１〜４のアルキレン基、若しくはフェニレン基を示し、それらは置換基を有していてもよい。また、Ｒ_２〜Ｒ_７は、それぞれ独立に、炭素数１以上の炭化水素、脂肪族、又は芳香族から選ばれる１価の有機基を示す。また、ｎは１以上の整数である。）

(In the formula, R ₁ and R ₈ each independently represents an alkylene group having 1 to 4 carbon atoms or a phenylene group, which may have a substituent. _{2 to} R ₇ each independently represents a monovalent organic group selected from a hydrocarbon having 1 or more carbon atoms, an aliphatic group, or an aromatic group, and n is an integer of 1 or more.

  Thereby, the siloxane modified block polyimide resin copolymer by which each segment length was controlled can be obtained. The first active terminal group and the second active terminal group are different anhydride groups or amino groups.

  Examples of the acid dianhydrides represented by the general formulas (1) to (3) include 3,4′-oxydiphthalic anhydride, 3,3′-oxydiphthalic anhydride, 3,3 ′, 4,4′-benzophenone. Tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, pyromellitic dianhydride 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 Examples thereof include ', 4'-biphenyltetracarboxylic dianhydride. Among these, when 3,4′-oxydiphthalic anhydride (abbreviation: a-ODPA), which is an asymmetric structural isomer of oxydiphthalic anhydride, is used, the symmetry is lost and the solvent solubility is dramatically improved. Can do.

  Examples of the aromatic diamine represented by the general formula (4) include 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 1,1-bis [4- (3-aminophenoxy) phenyl]. Ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-amino) Phenoxy) phenyl] butane, 4,4′-oxydianiline, 4,4′-diaminodiphenylsulfone, 3,4′-oxydianiline, 2,2′-bis (trifluoromethyl) -4,4′- Diaminobiphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophen Xyl) phenyl] sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 3,3′-dihydroxy-4,4′-diaminobiphenyl, 3,3′-diamino-4,4′-dihydroxydiphenylsulfone Etc. can be illustrated. Among these, if 2,2-bis [4- (4-aminophenoxy) phenyl] propane (abbreviation: BAPP) is used, flexibility can be improved.

Examples of the diaminosiloxane represented by the general formula (5) include diaminopolysiloxane compounds in which R ₁ and R ₈ are both propylene groups and R2 to R7 are both methyl groups.

  In the polymerization of the hard segment, the polymerization of the soft segment, and the polymerization of the siloxane-modified block polyimide resin described above, toluene as an azeotropic agent is added, and after raising the temperature to 150 to 200 ° C., while removing the toluene from the trap, It can be imidized by heat condensation. As the organic solvent, soluble lactone, amide, glyme, ester and ether solvents can be used, but γ-butyllactone (abbreviation: GBL) having low water absorption is used. preferable.

  In the method for producing a polyimide resin in the present embodiment, a terminal active aromatic hard segment and a terminal active siloxane-containing soft segment each having an arbitrary polymer chain length are obtained in the above-described hard segment polymerization and soft segment polymerization. be able to. That is, according to the method for producing a polyimide resin in the present embodiment, a siloxane-modified block polyimide resin having controlled characteristics can be obtained.

  At that time, when the number average molecular weight of the terminal active siloxane-containing soft segment is 4000 or more, the resulting siloxane-modified block polyimide resin is given flexibility, and when the polyimide resin is formed into a film, tackiness is imparted to the film surface. Can be made.

  Moreover, when the number average molecular weight of the terminal active aromatic hard segment is 2000 or more, the resulting siloxane-modified block polyimide resin can be easily formed.

  The siloxane-modified block polyimide resin thus obtained has a phase separation structure (sea-island structure) that is not found in a random copolymer corresponding to the same composition. By controlling this structure, the surface tack can be changed, and the elastic modulus can be made lower than that of a random copolymer film having the same composition.

  Further, since this siloxane-modified block polyimide resin can be dissolved in γ-butyrolactone at a high concentration, it is suitable for a coating method such as screen printing. Furthermore, since it is possible to control the formation of a thick film and the tackiness, it can be used as a heat-resistant adhesive used in a coverlay for a flexible printed circuit board or an electronic material.

  Further, the siloxane-modified block polyimide resin thus obtained is in a state dissolved in an organic solvent such as γ-butyrolactone. Therefore, if this solution contains additives such as antifoaming agents, leveling agents, inorganic fillers, organic fillers, pigments, dyes, metal deactivators, crosslinking agents, etc., siloxane-modified block polyimide resin varnish Can be used as

  The leveling aid or antifoaming agent is preferably added in an amount of about 100 ppm to 10,000 ppm, thereby suppressing foaming and flattening the coating film. Preferable examples of the leveling aid or antifoaming agent include fluorosilicone FA-600 manufactured by Shin-Etsu Chemical Co., Ltd., silicone-based BYK-065, BYK-066N, BYK-077 manufactured by BYK, and polymer BYK-. 052, BYK-051, BYK-055, leveling agents BYK-337, BYK-344, and the like, but are not limited thereto.

  Further, in order to improve the coating property, particularly the printing property, an inorganic filler, an organic filler, or the like can be used. As a suitable example, an average particle diameter of 0.001 to 15 μm, particularly 0.005 to 10 μm is preferable. The amount used may be an amount that can improve the printability, and is 0.5 to 50 parts by weight, preferably 1 to 20 parts by weight, based on the siloxane-modified block polyimide resin. If a coating outside this range is used, cracks may occur when the resulting coating is bent, or the bent portion may be whitened. Examples of the filler include fine inorganic fillers such as aerosil, talc, mica and barium sulfate, and fine organic fillers such as crosslinked NBR (Nitrile Butadiene Rubber) fine particles.

  Moreover, in this Embodiment, you may use an organic coloring pigment, an inorganic coloring pigment, etc. for a predetermined amount, for example, about 0-10 weight part with respect to 100 weight part of siloxane modified block polyimide resins.

  The siloxane-modified block polyimide resin may contain a metal deactivator. Examples of the metal deactivator include 2,3-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] propionohydrazide (ADEKA) which is a hydrazide metal deactivator. CDA-10) manufactured by the company can be used, and when used for a flexible wiring board, it is possible to prevent resin deterioration of the polyimide composition that comes into contact with the metal. Examples of metal deactivators other than CDA-10 include decamethylenecarboxylic acid disalicyloyl hydrazide as hydrazide-based compounds, and 3- (N-salicyloyl) amino-1,2,4-triazole as triazole-based compounds. Although it is mentioned, it is not limited to these.

  Further, the siloxane-modified block polyimide resin obtained in the present embodiment may contain a crosslinking agent. The amount of the crosslinking agent is preferably 50 parts by weight or less with respect to 100 parts by weight of the siloxane-modified block polyimide resin. When the amount of the crosslinking agent exceeds 50 parts by weight, the stability of the siloxane-modified block polyimide resin composition is deteriorated and the viscosity is increased, so that the handling as a solution is deteriorated.

  Examples of suitable crosslinking agents include epoxy groups and maleimide groups. These are not particularly limited as long as they are soluble in a solvent, and examples thereof include the following compounds. Examples of the crosslinking agent having an epoxy group as a functional group include alicyclic epoxy compounds such as bis F type epoxy compounds, bis A type epoxy compounds, and 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate. Sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, polyethylene glycol glycidyl ether, poly Glycidyl ether compounds such as propylene glycol diglycidyl ether, hydroquinone diglycidyl ether, glycidyl ester compounds such as diglycidyl phthalate, glycidyl terephthalate, halogenated flame retardant epoxy compounds such as dibromoneopentyl glycol glycidyl ether, Examples include cresol novolac epoxy resins and phenol novolac epoxy resins.

  In addition, this invention is not restricted to embodiment mentioned above, For example, if the hard segment and soft segment based on General formula (1)-(5) are imidated, a hard segment and a soft segment will be It is possible to include two or more of each. Moreover, when imidating the hard segment and soft segment based on the general formulas (1) to (5), it is also possible to imidize by adding other acid anhydrides and diamines within the range of the object of the present invention. is there.

  Also, for example, different hard segments or different soft segments can be imidized. That is, at least one acid dianhydride selected from general formulas (1) to (3) is reacted with at least one diamine selected from general formulas (4) and (5) to form an acid anhydride group. Alternatively, at least one segment having a first active terminal group composed of an amino group is synthesized, and at least one acid dianhydride selected from the general formulas (1) to (3) and the general formula (4), ( 5) at least one kind of diamine selected from the group consisting of an acid anhydride group or an amino group, and at least one kind of segment having the first active end group. And at least one segment having a second active terminal group may be imidized.

<3. Example>
Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Example 1]
<Polymerization of terminal amine active PI [a-ODPA (56.7 mol%) / x22-9409 (66.7 mol%)]>
Diaminosiloxane 26.80 g (20.00 mmol, manufactured by Shin-Etsu Chemical Co., Ltd., product name x22-9409, amine value 670) in a 100 mL separable flask A provided with a nitrogen introduction tube and a Dean-Stark trap, γ-butyrolactone (GBL) After adding 10 g and stirring well, 5.273 g (17.00 mmol) of 3,4′-oxydiphthalic anhydride (a-ODPA) which is an acid dianhydride monomer was gradually added. To this dispersion, 5 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then the toluene was removed from the trap, and further stirred at 180 ° C. for 30 minutes. While removing, solution imidization was performed to produce an amine-terminated polyimide resin represented by the following formula (6). The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (43.3 mol%) / BAPP (33.3 mol%)]>
On the other hand, into a new 100 mL separable flask B provided with a nitrogen introduction tube and a Dean Stark trap, 4.105 g (10.00 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) GBL (15 g) was added and completely dissolved, and 4.032 g (13.00 mmol) of a-ODPA was gradually added. To this dispersion, 5 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then the toluene was removed from the trap, and further stirred at 180 ° C. for 30 minutes. While removing, solution imidization was performed to produce an acid dianhydride-terminated polyimide resin represented by the following formula (7). The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (56.7 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (43.3 mol%) / BAPP (33.3 mol%)]]>
1.8 g of GBL was added to the separable flask B in which the acid dianhydride-terminated polyimide resin (solid content concentration 34%) was produced from the amine-terminated polyimide resin (solid content concentration 76%) synthesized in the separable flask A. All of the solution was added while washing with water, and after stirring well, 5 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then the toluene was removed from the trap and further 180 ° C. for 30 minutes. Solution imidization was carried out while removing toluene by stirring at 1 to obtain a target substance represented by the following formula (8).

[Example 2]
<Polymerization of terminal amine active PI [a-ODPA (50.0 mol%) / x22-9409 (66.7 mol%)]>
An amine-terminated polyimide resin was produced in the same manner as in Example 1 except that 4.653 g (15.00 mmol) of a-ODPA was added. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (50.0 mol%) / BAPP (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 1 except that 4.653 g (15.00 mmol) of a-ODPA was added. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (50.0 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (50.0 mol%) / BAPP (33.3 mol%)]]>
Amine-terminated polyimide resin [a-ODPA (50.0 mol%) / x22-9409 (66.7 mol%)] is added to acid dianhydride-terminated polyimide resin [a-ODPA (50.0 mol%) / BAPP (33.3 mol%)] In the same manner as in Example 1, the target substance was obtained.

[Example 3]
<Polymerization of terminal amine active PI [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)]>
An amine-terminated polyimide resin was produced in the same manner as in Example 1 except that 3.722 g (12.00 mmol) of a-ODPA was added. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (60.0 mol%) / BAPP (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 1 except that 5.584 g (18.00 mmol) of a-ODPA was added. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (60.0 mol%) / BAPP (33.3 mol%)]]>
Amine-terminated polyimide resin [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] was added to acid dianhydride-terminated polyimide resin [a-ODPA (60.0 mol%) / BAPP (33.3 mol%)] In the same manner as in Example 1, the target substance was obtained.

[Example 4]
<Polymerization of terminal amine active PI [s-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)]>
An amine-terminated polyimide resin was produced in the same manner as in Example 3 except that 3.722 g (12.00 mmol) of 4,4′-oxydiphthalic anhydride (s-ODPA) was added instead of a-ODPA. . The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [s-ODPA (60.0 mol%) / BAPP (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 3 except that 5.584 g (18.00 mmol) of s-ODPA was added instead of a-ODPA. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[s-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] / [s-ODPA (60.0 mol%) / BAPP (33.3 mol%)]]>
Amine-terminated polyimide resin [s-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] is added to acid dianhydride-terminated polyimide resin [s-ODPA (60.0 mol%) / BAPP (33.3 mol%)] Then, after washing all with 7.9 g of GBL and thoroughly stirring, 5 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then toluene was removed from the trap. Furthermore, solution imidization was performed while removing toluene by stirring at 180 ° C. for 30 minutes to obtain the target substance. The weight average molecular weight (Mw) was 48947, and the number average molecular weight (Mn) was 10229.

[Example 5]
<Polymerization of terminal amine active PI [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)]>
In the same manner as in Example 3, an amine-terminated polyimide resin was produced. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (60.0 mol%) / 4,4'-ODA (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 3, except that 2.002 g (10.00 mmol) of 4,4′-oxydianiline (4,4′-ODA) was added instead of BAPP. I let you. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (60.0 mol%) / 4,4'-ODA (33.3 mol%)]]>
Amine-terminated polyimide resin [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] was converted to acid dianhydride-terminated polyimide resin [a-ODPA (60.0 mol%) / 4,4'-ODA (33.3 mol) %)], And after thoroughly washing with 0.4 g of GBL, stirring well, adding 5 g of toluene as an azeotropic agent, raising the internal temperature to 180 ° C., holding for 30 minutes, and then adding toluene. The solution was removed from the trap, and further solution imidization was performed while removing toluene by stirring at 180 ° C. for 30 minutes to obtain the target substance. The weight average molecular weight (Mw) was 33013, and the number average molecular weight (Mn) was 8724.

[Synthesis Example 1]
<Synthesis of siloxane polyimide resin>
Diaminosiloxane 64.96 g (48.48 mmol, manufactured by Shin-Etsu Chemical Co., Ltd., product name x22-9409, amine value 670) and GBL 20 g were put into a 500 mL separable flask provided with a nitrogen introduction tube and a Dean-Stark trap, and stirred well. Then, 15.04 g (48.48 mmol) of a-ODPA which is an acid dianhydride monomer was gradually added. To this dispersion, 5 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then the toluene was removed from the trap, and further stirred at 180 ° C. for 30 minutes. While removing, solution imidization was carried out to produce a homopolymer polyimide resin represented by the following formula (9).

[Synthesis Example 2]
<Synthesis of aromatic polyimide resin>
BAPP 25.62 g (62.46 mmol) and GBL 55 g were put into a 500 mL separable flask provided with a nitrogen introduction tube and a Dean-Stark trap, dissolved completely, and 19.36 g (62.46 mmol) of a-ODPA was gradually dissolved. Added to. To this dispersion, 5 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then the toluene was removed from the trap, and further stirred at 180 ° C. for 30 minutes. While removing, solution imidization was carried out to produce a homopolymer polyimide resin represented by the following formula (10).

[Comparative Example 1]
<Blend>
10 g of each of the polyimide resin varnishes obtained in Synthesis Example 1 and Synthesis Example 2 were weighed, and using an appropriate amount of Zr stirring beads having a diameter of 5 mm, a planetary stirring device (2000 rpm, rotation / revolution ratio = 2: 5) manufactured by Shinky Co., Ltd. ).

[Comparative Example 2]
<Random copolymerization>
Diaminosiloxane 79.98 g (59.69 mmol, manufactured by Shin-Etsu Chemical Co., Ltd., product name x22-9409, amine value 686), BAPP 12.25 g (29.85 mmol) into a 500 mL separable flask provided with a nitrogen introduction tube and a Dean-Stark trap ), 80 g of GBL were added, and after stirring well, 27.78 g (89.54 mmol) of a-ODPA was gradually added. To this dispersion, 30 g of toluene as an azeotropic agent was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then the toluene was removed from the trap, and further stirred at 180 ° C. for 30 minutes. While removing, solution imidization was performed to obtain a uniform solution of a random copolymer represented by the following formula (11).

[Molecular weight measurement]
A portion of the amine-terminated polyimide resin of Examples 1-3 (polyimide resin A), acid dianhydride-terminated polyimide resin (polyimide resin B), siloxane-modified block polyimide resin, and random copolymer of Comparative Example 2 were extracted. These were each diluted to 0.5 wt% with THF (tetrahydrofuran) and analyzed by GPC (Gel Permeation Chromatography) system (Shodex GPC system-21 manufactured by Showa Denko KK). Average molecular weight (Mw), number average molecular weight (Mn), and polydispersity (Mw / Mn) were measured. The reduced viscosity (ηred) of the siloxane-modified block polyimide resin of Example 3 and the random copolymer of Comparative Example 2 was measured. Columns (KF-G, KF-606, KF-605, KF-604, KF-601, KF-600D) were calibrated with standard polystyrene at a temperature of 40 ° C. and a flow rate of 1 mL / min.

  In Table 1, the GPC measurement result of the amine terminal polyimide (polyimide A) of Examples 1-3 and an acid dianhydride terminal polyimide (polyimide B) is shown. Table 2 shows the GPC measurement results of the siloxane-modified block polyimide resins of Examples 1 to 3 and the random copolymer of Comparative Example 2.

  FIG. 4 is a GPC chart of polyimide resins of Examples 1 to 3 and Comparative Example 2. The GPC chart of the block polyimide resin of Examples 1 to 3 and the GPC chart of the random polymer of Comparative Example 2 were almost the same. In addition, a small peak is observed at a retention time of 21.5 min regardless of the block size. This is considered to be because siloxane having no functional group was contained in the monomer.

[Measurement of elastic modulus, etc.]
The sample of Example 3 and Comparative Example 2 (length 30 mm, width 10 mm, thickness 50 μm) was mounted on a dynamic viscoelasticity measuring apparatus (DMA-Q800 manufactured by TA Instruments), and the temperature rising rate was 5 ° C./min. The storage elastic modulus (E ′) and loss elastic modulus (E ″) in the temperature range of −100 to 200 ° C. were measured. Also, tan δ (loss elastic modulus / storage elastic modulus obtained under the measurement condition of a frequency of 10 MHz was measured. ) Was the glass transition temperature (Tg).

  FIG. 5 shows the DMA curve (a) of the polyimide resin of Example 3 and the DMA curve (b) of the polyimide resin of Comparative Example 3. The storage elastic modulus E ′ of both was constant at about 2 GPa at −30 ° C. or lower. This is probably because the siloxane segment was frozen at -30 ° C or lower. Moreover, since the polyimide resin of Example 3 has a lower storage elastic modulus (E ′) at room temperature than the random copolymer of Comparative Example 2, the amount of the crosslinking agent added to the polyimide resin of Example 3 is increased. It can be seen that characteristics such as elastic modulus, chemical resistance and glass transition temperature can be greatly controlled.

Further, using thermal gravimetric analysis (TGA), the 10 ° C. / min or under air atmosphere nitrogen atmosphere was measured at a heating rate of 5% weight loss temperature was thermal decomposition temperature (T d ^_5). Moreover, the glass transition temperature (Tg) was measured.

Further, using a tensile tester (Tensilon UTM-II manufactured by Toyo Baldwin) at a tensile speed of 8 mm / min, samples of Example 3 and Comparative Example 2 (length 30 mm, width 10 mm, thickness 50 μm) ) Tensile elastic modulus (E), elongation at break (ε _b ), and tensile strength (σ _b ).

  Table 3 shows the measurement results of Example 3 and Comparative Example 3.

[Characteristic evaluation]
Next, for Examples 1 to 3, Synthesis Examples 1 and 2, and Comparative Examples 1 and 2, the state of the polymerization solution, the internal phase separation state when formed into a film, the phase separation structure, and the tack were evaluated.

  The state of the polymerization solution was visually confirmed after standing for 14 days at room temperature after polymerization. Here, the liquid with no unevenness in the solution was evaluated as “uniformly transparent”. Moreover, although there was no nonuniformity in the solution, the cloudy state was evaluated as “uniform turbidity”. The state where the solution was separated into two layers was evaluated as “liquid separation”.

  When the film was formed, the internal phase separation state was such that the polymerization solution was cast onto a glass plate with a doctor blade and dried in a forced convection oven at 100 ° C. for 10 minutes. At this time, a case where severe liquid separation occurred and casting was impossible was evaluated as “film formation impossible”. After drying, it was baked at 200 ° C. for 1 hour in a vacuum oven. The obtained film was peeled off from the glass plate and frozen in liquid nitrogen, then the cross section was cut and observed with a metallographic microscope and a scanning electron microscope (SEM). At this time, the case where the film was too soft to be peeled off from the glass substrate was evaluated as “unpeelable”.

  The phase separation structure was observed by spot element analysis using an energy dispersive X-ray fluorescence analyzer (EXD) for a sample whose cross section could be observed by SEM. By monitoring silicon, it was determined whether the phase forming the phase separation was siloxane PI or aromatic PI.

  Tack stretched the film obtained by baking at 200 degreeC for 1 hour to the glass surface, and evaluated the adhesion | attachment degree in 6 steps, 0-5. 0 indicates no tack at all, and 5 indicates a very strong tack, and the value between them is evaluated numerically.

  Table 4 shows the evaluation results. 6 to 8 are schematic diagrams of a metal micrograph, an SEM photograph, and a phase separation structure of the film of Example 1, respectively. Moreover, FIGS. 9-11 is the schematic diagram of the metal micrograph of a film of Example 2, a SEM photograph, and a phase-separation structure, respectively.

  In the case of the conventional polymer blend as in Comparative Example 1, in the case of this reaction system, liquid separation occurs instantaneously and film formation by casting is impossible. Further, the homopolyimide resin of Synthesis Example 1 was expected to have a solid content concentration of 80% or more in a γ-butyrolactone solvent and excellent printing characteristics, but the film was soft and the glass transition temperature was below room temperature. Filming was difficult. Moreover, since the homopolyimide resin of Synthesis Example 2 has a high glass transition temperature and a high elastic modulus, there is a concern about an increase in repulsive force when used as an FPC coverlay.

  Since Comparative Example 2 was obtained by random copolymerization of siloxane and BAPP, which were polyimide resin components, film formation was possible, but the properties of both polyimide resins were averaged and the tackiness was not high.

  In Examples 1 to 3 and Comparative Example 2, the composition ratio of all monomers constituting the polyimide resin was the same, but it was found that the state of the polymerization solution, the phase separation state of the film, and the tackiness were different. That is, in Examples 1 to 3, characteristics (such as increased tackiness) that were not found in the random copolymer of Comparative Example 2 were developed. This is considered to be a result of changing the phase separation structure by a block operation in which a heterogeneous polymer is formed and both polymers are polymerized while leaving a terminal active group.

  For example, in the number average molecular weight of polyimide A shown in Table 1, the tack force improved as the number average molecular weight of 4000 or more increased. Further, from the phase separation structure of Example 1 shown in FIGS. 6 to 8 and the phase separation structure of Example 2 shown in FIGS. 9 to 11, the island of aromatic polyimide in the sea-island structure is smaller in Example 1, It turns out that tack power is large.

[Screen printability]
FIG. 12 is a schematic diagram showing a screen printing test pattern. To the polyimide resin varnish of Example 3 having a solid concentration of 60%, 10 phr of a thixotropy adjusting agent (Nippon Aerosil Co., Ltd., Aerosil RY200) was added. This was coated at intervals of 400 μm space and 600 μm PI line, and then dried at 100 ° C. for 10 minutes. Observation with an optical microscope revealed that the screen printability was good.

  Similarly, 15 phr of thixotropic modifier (Aerosil RY200, manufactured by Nippon Aerosil Co., Ltd.) was applied to the polyimide resin varnish of Example 4 having a solid content concentration of 55% and the polyimide resin varnish of Example 5 having a solid content concentration of 60%. When 175 ppm of a foaming agent (manufactured by Shin-Etsu Chemical Co., Ltd., FA-600) was added and the screen printability was confirmed, the same good printability as in Example 3 was confirmed.

  The present invention relates to a method for producing a polyimide resin comprising a block polyimide resin copolymer, and a polyimide resin.

  Polyimide resin (PI) is applied to various electronic devices because of its high elastic modulus, relatively low thermal expansion coefficient, high heat resistance, insulation, and chemical resistance (solvent resistance). It is widely used as a base film material for copper-clad laminates for Flexible Printed Circuits) and as a coverlay (protective film) for the purpose of protecting conductive circuits (for example, see Patent Document 1).

  The FPC is used for a thin and compact part such as around the LCD (Liquid Crystal Display) of a mobile phone, and is bent when assembled. If the FPC has high resilience, it is difficult to incorporate the FPC when it is incorporated into the housing, so a considerable amount of material that can give flexibility to the main chain of the polyimide resin (such as a siloxane skeleton) is incorporated, and low elasticity To reduce the repulsive force.

  The coverlay is classified into a film type and an ink type depending on the state of the cover material. In the FPC manufacturing method, the film type is used by laminating or pressing, and the ink type is used by a wet method such as screen printing or gravure printing. As the ink type polyimide resin, there is known a solvent-soluble polyimide resin that incorporates a material capable of imparting flexibility to the main chain of the polyimide resin and completes imidization in a solvent (such as γ-butyrolactone) used for printing. It has been.

As described above, since a polymer material such as a polyimide resin is required to have characteristics suitable for the application, it is necessary to control the characteristics of the polymer itself. By the way, generally, the following means are known as a method for controlling the characteristics of a polymer.
Change the chemical composition of the polymer. ... Methods for controlling the primary structure of polymers such as random copolymerization and alternating copolymerization.
Control the chain orientation of the polymer film. ... Method of controlling secondary structure of polymer by means such as stretching or controlling higher order structure such as crystallization.
• Blend two or more polymers. ... So-called polymer blends.
• Blend additives (other than polymers) to the polymer. ... So-called composite and hybrid technology (eg glass epoxy).

  Here, the above-mentioned polymer blend may have properties superior to those obtained by changing (copolymerizing) the chemical composition of the polymer. For example, a film obtained by blending both a high hardness but a fragile homopolymer and a homopolymer having a high flexibility but a low hardness may be able to make use of the advantages by making up for each other's drawbacks.

JP 2003-155343 A

  However, when the polymer blend has poor compatibility between the polymers, desired characteristics cannot be obtained. For example, even if an attempt is made to blend a very different polymer such as a blend of a siloxane polyimide resin and a general aromatic polyimide resin, film formation is difficult due to vigorous phase separation because it is a completely incompatible system. .

  This invention is proposed in view of such a conventional situation, and provides the manufacturing method of the polyimide resin which can obtain a desired characteristic, and a polyimide resin.

  As a result of intensive studies, the inventors of the present invention have different properties, that is, when a different type of polyimide resin is used to obtain desired characteristics, the terminal active group forms a different type of polyimide resin segment (polyimide resin chain). As a result, it was found that when these terminal active groups are chemically bonded, the resulting polyimide resin can be controlled so that the characteristics of each segment can be expressed.

  That is, in the method for producing a polyimide resin according to the present invention, at least one acid dianhydride selected from general formulas (1) to (3) is reacted with an aromatic diamine represented by general formula (4). , Synthesizing at least one hard segment having a first active terminal group consisting of an acid anhydride group or an amino group, and at least one acid dianhydride selected from the general formulas (1) to (3); By reacting with the diaminosiloxane represented by the formula (5), at least one soft segment having a second active terminal group comprising an acid anhydride group or an amino group is synthesized, and at least one having the first active terminal group is synthesized. A kind of hard segment and at least one kind of soft segment having the second active terminal group are imidized.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｘは、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、又はアルコキシ基で置換されていてもよい。）

(Wherein R ₁ and R ₂ are each independently absent or represent hydrogen, methyl group, trifluoromethyl group, and X is C═O, SO ₂ , S, O, C, or directly And each benzene ring may be substituted with a halogen, an alkyl group, or an alkoxy group.)

（式中、Ｒ_１〜Ｒ_６は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｙ_１、Ｙ_２及びＺは、それぞれ独立に、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、ヒドロキシル基、又はアルコキシ基で置換されていてもよい。また、ｍは、０又は１である。）

(Wherein R _{1 to} R ₆ each independently does not exist or represents hydrogen, a methyl group, or a trifluoromethyl group, and Y ₁ , Y _2, and Z each independently represent C═O, SO ₂ , S, O, C, or a direct bond, and each benzene ring may be substituted with a halogen, an alkyl group, a hydroxyl group, or an alkoxy group, and m is 0 or 1. .)

（式中、Ｒ_１及びＲ_８は、それぞれ独立に、存在しないか、又は炭素数１〜４のアルキレン基、若しくはフェニレン基を示し、それらは置換基を有していてもよい。また、Ｒ_２〜Ｒ_７は、それぞれ独立に、炭素数１以上の炭化水素、脂肪族、又は芳香族から選ばれる１価の有機基を示す。また、ｎは１以上の整数である。）

(In the formula, R ₁ and R ₈ each independently represents an alkylene group having 1 to 4 carbon atoms or a phenylene group, which may have a substituent. _{2 to} R ₇ each independently represents a monovalent organic group selected from a hydrocarbon having 1 or more carbon atoms, an aliphatic group, or an aromatic group, and n is an integer of 1 or more.

  In addition, the polyimide resin according to the present invention is obtained by the manufacturing method described above.

  According to this invention, since the characteristic of a polyimide resin is controllable, the outstanding characteristic can be expressed.

It is a figure for demonstrating the blend of a different polymer. It is a figure for demonstrating random copolymerization. It is a figure for demonstrating the superposition | polymerization method in this Embodiment. It is a GPC chart of the polyimide resin of Examples 1-3 and Comparative Example 2. It is a graph which shows the DMA curve (a) of Example 3, and the DMA curve (b) of the comparative example 3. 2 is a metal micrograph of the film of Example 1. 2 is a SEM photograph of the film of Example 1. 2 is a schematic diagram of a phase separation structure of the film of Example 1. FIG. 2 is a metal micrograph of the film of Example 2. 3 is a SEM photograph of the film of Example 2. 2 is a metal micrograph of the film of Example 2. It is a schematic diagram which shows the test pattern of screen printing.

Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings.
1. 1. Outline of the present invention Specific Example 3 Example

<1. Summary of the present invention>
One important factor in the method for producing the polyimide resin (PI) in the present embodiment is the compatibility between different types of polymers. In general, factors that determine the compatibility of polymers include the following.
・ Chemical structure (Similar solubility parameters are compatible with each other.)
・ Molecular weight (Small molecular weights are compatible with each other.)
・ Molecular chain mobility (for example, viscosity, temperature, stirring conditions, etc., because the molecular chain movement is affected, so compatibility can be controlled.)
・ Compatibilizer (for example, surfactant)

  In a so-called polymer blend in which different types of polymers are blended, it is difficult to form a film by vigorous phase separation when the chemical structures are different. For example, a blend of a siloxane polyimide resin (polymer A) and a general aromatic polyimide resin (polymer B) having extremely different properties as shown in FIG. Processing (film formation) becomes difficult. In such a case, as shown in FIG. 2, if the monomers A and B are randomly copolymerized, a uniform solution is obtained, but the respective characteristics are averaged.

  In addition, by incorporating a similar chemical structure into the blending partner, compatibility may be improved and film formability may be improved. However, since the properties of the polymer are simply averaged as in the case of a random copolymer and the film properties of the blend are similar, there is a possibility that the initially expected effect may not be exhibited.

  In addition, when the molecular weight is reduced, the compatibility can be easily controlled, but the entanglement of the polymer chain may be reduced to deteriorate the film characteristics. In addition, means for freezing the movement of polymer chains so that they are not mixed and separated by vigorous physical agitation (for example, thickening at low temperatures, instantaneous solvent volatilization after mixing, etc.) Difficult due to equipment constraints and difficulty in ensuring stable quality. In addition, the compatibilizing agent has low heat resistance of the substance itself, so that the heat resistance of the polymer itself may be reduced, and problems such as bleeding out may occur.

  Therefore, in this embodiment, the degree of polymerization of the block copolymerization method, particularly the A component and the B component, is increased in advance, leaving the respective terminal activities, and finally AB is chemically bonded. Specifically, as shown in FIG. 3, a block operation is performed in which different polymers (terminal active polymer A and terminal active polymer B) are formed while the terminal active groups remain, and both polymers are polymerized. Thereby, since different polymer chains are chemically bonded, separation of the solution (liquid separation) can be prevented. Further, since each of the different polymers has a high molecular weight, when formed into a film, an appropriate phase separation structure develops, the characteristics of both are not averaged, and excellent characteristics are exhibited.

<3. Specific example>
The method for producing a polyimide resin in the present embodiment can be applied to a completely incompatible system represented by a blend of a siloxane polyimide resin and a general aromatic polyimide resin as described above.

  Since the siloxane polyimide resin has high flexibility, high elongation, and low elastic modulus due to its siloxane skeleton, it can be said that such a siloxane polyimide resin has a soft segment. On the other hand, since the aromatic polyimide resin is derived from the aromatic ring and has a high elastic modulus and excellent flame retardancy, it can be said that such an aromatic polyimide resin has a hard segment. Of course, these characteristics are difficult to achieve in a single polyimide resin due to a trade-off relationship, but according to the method for manufacturing a polyimide resin in the present embodiment, these characteristics can be controlled.

That is, in the method for producing a polyimide resin in the present embodiment, at least one acid dianhydride selected from general formulas (1) to (3) is reacted with an aromatic diamine represented by general formula (4). And synthesizing at least one hard segment having a first active terminal group consisting of an acid anhydride group or an amino group, and at least one acid dianhydride selected from general formulas (1) to (3); Reaction with the diaminosiloxane represented by the general formula (5) to synthesize at least one soft segment having a second active terminal group consisting of an acid anhydride group or an amino group, and having at least the first active terminal group and one of the hard segment, is intended to imidization and at least one soft segment having a second active end groups.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｘは、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、又はアルコキシ基で置換されていてもよい。）

(Wherein R ₁ and R ₂ are each independently absent or represent hydrogen, methyl group, trifluoromethyl group, and X is C═O, SO ₂ , S, O, C, or directly And each benzene ring may be substituted with a halogen, an alkyl group, or an alkoxy group.)

（式中、Ｒ_１〜Ｒ_６は、それぞれ独立に、存在しないか、又は水素、メチル基、トリフルオロメチル基を示し、Ｙ_１、Ｙ_２及びＺは、それぞれ独立に、Ｃ＝Ｏ、ＳＯ_２、Ｓ、Ｏ、Ｃ、又は直接結合を示す。また、各ベンゼン環は、ハロゲン、アルキル基、ヒドロキシル基、又はアルコキシ基で置換されていてもよい。また、ｍは、０又は１である。）

(Wherein R _{1 to} R ₆ each independently does not exist or represents hydrogen, a methyl group, or a trifluoromethyl group, and Y ₁ , Y _2, and Z each independently represent C═O, SO ₂ , S, O, C, or a direct bond, and each benzene ring may be substituted with a halogen, an alkyl group, a hydroxyl group, or an alkoxy group, and m is 0 or 1. .)

（式中、Ｒ_１及びＲ_８は、それぞれ独立に、存在しないか、又は炭素数１〜４のアルキレン基、若しくはフェニレン基を示し、それらは置換基を有していてもよい。また、Ｒ_２〜Ｒ_７は、それぞれ独立に、炭素数１以上の炭化水素、脂肪族、又は芳香族から選ばれる１価の有機基を示す。また、ｎは１以上の整数である。）

(In the formula, R ₁ and R ₈ each independently represents an alkylene group having 1 to 4 carbon atoms or a phenylene group, which may have a substituent. _{2 to} R ₇ each independently represents a monovalent organic group selected from a hydrocarbon having 1 or more carbon atoms, an aliphatic group, or an aromatic group, and n is an integer of 1 or more.

  Thereby, the siloxane modified block polyimide resin copolymer by which each segment length was controlled can be obtained. The first active terminal group and the second active terminal group are different anhydride groups or amino groups.

The general formula (1) acid dianhydride represented by - (3), 2,3, 3,4'-oxydiphthalic anhydride, 3,4, 3,3'-oxydiphthalic anhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoro Propane, pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic acid An anhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride etc. can be illustrated. Among these, 2,3,3,4'-oxydiphthalic anhydride (abbreviation: a-ODPA) , which is an asymmetric structural isomer of oxydiphthalic anhydride, breaks symmetry and dramatically improves solvent solubility Can be enhanced.

  Examples of the aromatic diamine represented by the general formula (4) include 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 1,1-bis [4- (3-aminophenoxy) phenyl]. Ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-amino) Phenoxy) phenyl] butane, 4,4′-oxydianiline, 4,4′-diaminodiphenylsulfone, 3,4′-oxydianiline, 2,2′-bis (trifluoromethyl) -4,4′- Diaminobiphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophen Xyl) phenyl] sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 3,3′-dihydroxy-4,4′-diaminobiphenyl, 3,3′-diamino-4,4′-dihydroxydiphenylsulfone Etc. can be illustrated. Among these, if 2,2-bis [4- (4-aminophenoxy) phenyl] propane (abbreviation: BAPP) is used, flexibility can be improved.

Examples of the diaminosiloxane represented by the general formula (5) include diaminopolysiloxane compounds in which R ₁ and R ₈ are both propylene groups and R ₂ to R ₇ are both methyl groups.

Polymerization of the hard segment mentioned above, the polymerization of the soft segment, and in the polymerization of the siloxane-modified block polyimide resin, toluene is entrainer-product water of condensation was added, after heating to 150 to 200 ° C., and water It can be imidized by heat condensation while removing toluene from the trap. As the organic solvent, soluble lactone, amide, glyme, ester and ether solvents can be used, but γ-butyllactone (abbreviation: GBL) having low water absorption is used. preferable.

  In the method for producing a polyimide resin in the present embodiment, a terminal active aromatic hard segment and a terminal active siloxane-containing soft segment each having an arbitrary polymer chain length are obtained in the above-described hard segment polymerization and soft segment polymerization. be able to. That is, according to the method for producing a polyimide resin in the present embodiment, a siloxane-modified block polyimide resin having controlled characteristics can be obtained.

  At that time, when the number average molecular weight of the terminal active siloxane-containing soft segment is 4000 or more, the resulting siloxane-modified block polyimide resin is given flexibility, and when the polyimide resin is formed into a film, tackiness is imparted to the film surface. Can be made.

  Moreover, when the number average molecular weight of the terminal active aromatic hard segment is 2000 or more, the resulting siloxane-modified block polyimide resin can be easily formed.

  The siloxane-modified block polyimide resin thus obtained has a phase separation structure (sea-island structure) that is not found in a random copolymer corresponding to the same composition. By controlling this structure, the surface tack can be changed, and the elastic modulus can be made lower than that of a random copolymer film having the same composition.

  Further, since this siloxane-modified block polyimide resin can be dissolved in γ-butyrolactone at a high concentration, it is suitable for a coating method such as screen printing. Furthermore, since it is possible to control the formation of a thick film and the tackiness, it can be used as a heat-resistant adhesive used in a coverlay for a flexible printed circuit board or an electronic material.

  Further, the siloxane-modified block polyimide resin thus obtained is in a state dissolved in an organic solvent such as γ-butyrolactone. Therefore, if this solution contains additives such as antifoaming agents, leveling agents, inorganic fillers, organic fillers, pigments, dyes, metal deactivators, crosslinking agents, etc., siloxane-modified block polyimide resin varnish Can be used as

The leveling agent or antifoaming agent is preferably added in an amount of about 100 ppm to 10000 ppm, thereby suppressing foaming and flattening the coating film. As a suitable example of a leveling agent or an antifoaming agent, Shin-Etsu Chemical Co., Ltd. product fluorosilicone FA-600, BYK silicone type BYK-065, BYK-066N, BYK-077, polymer type BYK-052, Examples include BYK-051, BYK-055, leveling agents BYK-337, BYK-344, but are not limited thereto.

  Further, in order to improve the coating property, particularly the printing property, an inorganic filler, an organic filler, or the like can be used. As a suitable example, an average particle diameter of 0.001 to 15 μm, particularly 0.005 to 10 μm is preferable. The amount used may be an amount that can improve the printability, and is 0.5 to 50 parts by weight, preferably 1 to 20 parts by weight, based on the siloxane-modified block polyimide resin. If a coating outside this range is used, cracks may occur when the resulting coating is bent, or the bent portion may be whitened. Examples of the filler include fine inorganic fillers such as aerosil, talc, mica and barium sulfate, and fine organic fillers such as crosslinked NBR (Nitrile Butadiene Rubber) fine particles.

  Moreover, in this Embodiment, you may use an organic coloring pigment, an inorganic coloring pigment, etc. for a predetermined amount, for example, about 0-10 weight part with respect to 100 weight part of siloxane modified block polyimide resins.

  The siloxane-modified block polyimide resin may contain a metal deactivator. Examples of the metal deactivator include 2,3-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] propionohydrazide (ADEKA) which is a hydrazide metal deactivator. CDA-10) manufactured by the company can be used, and when used for a flexible wiring board, it is possible to prevent resin deterioration of the polyimide composition that comes into contact with the metal. Examples of metal deactivators other than CDA-10 include decamethylenecarboxylic acid disalicyloyl hydrazide as hydrazide-based compounds, and 3- (N-salicyloyl) amino-1,2,4-triazole as triazole-based compounds. Although it is mentioned, it is not limited to these.

  Further, the siloxane-modified block polyimide resin obtained in the present embodiment may contain a crosslinking agent. The amount of the crosslinking agent is preferably 50 parts by weight or less with respect to 100 parts by weight of the siloxane-modified block polyimide resin. When the amount of the crosslinking agent exceeds 50 parts by weight, the stability of the siloxane-modified block polyimide resin composition is deteriorated and the viscosity is increased, so that the handling as a solution is deteriorated.

  Examples of suitable crosslinking agents include epoxy groups and maleimide groups. These are not particularly limited as long as they are soluble in a solvent, and examples thereof include the following compounds. Examples of the crosslinking agent having an epoxy group as a functional group include alicyclic epoxy compounds such as bis F type epoxy compounds, bis A type epoxy compounds, and 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate. Sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, polyethylene glycol glycidyl ether, poly Glycidyl ether compounds such as propylene glycol diglycidyl ether, hydroquinone diglycidyl ether, glycidyl ester compounds such as diglycidyl phthalate, glycidyl terephthalate, halogenated flame retardant epoxy compounds such as dibromoneopentyl glycol glycidyl ether, Examples include cresol novolac epoxy resins and phenol novolac epoxy resins.

  In addition, this invention is not restricted to embodiment mentioned above, For example, if the hard segment and soft segment based on General formula (1)-(5) are imidated, a hard segment and a soft segment will be It is possible to include two or more of each. Moreover, when imidating the hard segment and soft segment based on the general formulas (1) to (5), it is also possible to imidize by adding other acid anhydrides and diamines within the range of the object of the present invention. is there.

  Also, for example, different hard segments or different soft segments can be imidized. That is, at least one acid dianhydride selected from general formulas (1) to (3) is reacted with at least one diamine selected from general formulas (4) and (5) to form an acid anhydride group. Alternatively, at least one segment having a first active terminal group composed of an amino group is synthesized, and at least one acid dianhydride selected from the general formulas (1) to (3) and the general formula (4), ( 5) at least one kind of diamine selected from the group consisting of an acid anhydride group or an amino group, and at least one kind of segment having the first active end group. And at least one segment having a second active terminal group may be imidized.

<3. Example>
Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Example 1]
<Polymerization of terminal amine active PI [a-ODPA (56.7 mol%) / x22-9409 (66.7 mol%)]>
Diaminosiloxane 26.80 g (20.00 mmol, manufactured by Shin-Etsu Chemical Co., Ltd., product name x22-9409, amine value 670) in a 100 mL separable flask A provided with a nitrogen introduction tube and a Dean-Stark trap, γ-butyrolactone (GBL) After adding 10 g and stirring well, 5.273 g (17.00 mmol) of 3,4′-oxydiphthalic anhydride (a-ODPA) which is an acid dianhydride monomer was gradually added. To this dispersion is added 5 g of toluene, which is an azeotropic agent of by -product condensed water , the internal temperature is raised to 180 ° C. and held for 30 minutes, and then water and toluene are removed from the trap and 180 minutes for 180 minutes. Solution imidization was carried out while removing water and toluene from the trap by stirring at ° C. to produce an amine-terminated polyimide resin represented by the following formula (6). The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (43.3 mol%) / BAPP (33.3 mol%)]>
On the other hand, into a new 100 mL separable flask B provided with a nitrogen introduction tube and a Dean Stark trap, 4.105 g (10.00 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) GBL (15 g) was added and completely dissolved, and 4.032 g (13.00 mmol) of a-ODPA was gradually added. To this dispersion is added 5 g of toluene, which is an azeotropic agent of by -product condensed water , the internal temperature is raised to 180 ° C. and held for 30 minutes, and then water and toluene are removed from the trap and 180 minutes for 180 minutes. Solution imidization was carried out while removing water and toluene from the trap by stirring at ° C. to produce an acid dianhydride-terminated polyimide resin represented by the following formula (7). The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (56.7 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (43.3 mol%) / BAPP (33.3 mol%)]]>
1.8 g of GBL was added to the separable flask B in which the acid dianhydride-terminated polyimide resin (solid content concentration 34%) was produced from the amine-terminated polyimide resin (solid content concentration 76%) synthesized in the separable flask A. All the water was added while washing, and after stirring well, 5 g of toluene, which is an azeotropic agent of by -product condensed water, was added, the internal temperature was raised to 180 ° C., held for 30 minutes, and then water and toluene were removed from the trap. Then, the mixture was further stirred for 30 minutes at 180 ° C. to remove water and toluene from the trap , and solution imidization was performed to obtain a target substance represented by the following formula (8).

[Example 2]
<Polymerization of terminal amine active PI [a-ODPA (50.0 mol%) / x22-9409 (66.7 mol%)]>
An amine-terminated polyimide resin was produced in the same manner as in Example 1 except that 4.653 g (15.00 mmol) of a-ODPA was added. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (50.0 mol%) / BAPP (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 1 except that 4.653 g (15.00 mmol) of a-ODPA was added. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (50.0 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (50.0 mol%) / BAPP (33.3 mol%)]]>
Amine-terminated polyimide resin [a-ODPA (50.0 mol%) / x22-9409 (66.7 mol%)] is added to acid dianhydride-terminated polyimide resin [a-ODPA (50.0 mol%) / BAPP (33.3 mol%)] In the same manner as in Example 1, the target substance was obtained.

[Example 3]
<Polymerization of terminal amine active PI [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)]>
An amine-terminated polyimide resin was produced in the same manner as in Example 1 except that 3.722 g (12.00 mmol) of a-ODPA was added. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (60.0 mol%) / BAPP (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 1 except that 5.584 g (18.00 mmol) of a-ODPA was added. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (60.0 mol%) / BAPP (33.3 mol%)]]>
Amine-terminated polyimide resin [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] was added to acid dianhydride-terminated polyimide resin [a-ODPA (60.0 mol%) / BAPP (33.3 mol%)] In the same manner as in Example 1, the target substance was obtained.

[Example 4]
<Polymerization of terminal amine active PI [s-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)]>
Amine-terminated polyimide in the same manner as in Example 3, except that 3.722 g (12.00 mmol) of 3,4,3 ′ , 4′-oxydiphthalic anhydride (s-ODPA) was added instead of a-ODPA. Resin was produced. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [s-ODPA (60.0 mol%) / BAPP (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 3 except that 5.584 g (18.00 mmol) of s-ODPA was added instead of a-ODPA. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[s-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] / [s-ODPA (60.0 mol%) / BAPP (33.3 mol%)]]>
Amine-terminated polyimide resin [s-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] is added to acid dianhydride-terminated polyimide resin [s-ODPA (60.0 mol%) / BAPP (33.3 mol%)] and, all charged with rinse with GBL7.9G, well stirred, toluene 5g is entrainer-product water of condensation was added and the internal temperature was increased to 180 ° C., water after 30 minutes And toluene were removed from the trap , and solution imidization was carried out while stirring at 180 ° C. for 30 minutes to remove water and toluene from the trap to obtain the target substance. The weight average molecular weight (Mw) was 48947, and the number average molecular weight (Mn) was 10229.

[Example 5]
<Polymerization of terminal amine active PI [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)]>
In the same manner as in Example 3, an amine-terminated polyimide resin was produced. The imidation ratio of this amine-terminated polyimide resin was 100% (FT-IR).

<Polymerization of terminal acid anhydride active PI [a-ODPA (60.0 mol%) / 4,4'-ODA (33.3 mol%)]>
An acid dianhydride-terminated polyimide resin was produced in the same manner as in Example 3, except that 2.002 g (10.00 mmol) of 4,4′-oxydianiline (4,4′-ODA) was added instead of BAPP. I let you. The imidation ratio of this acid dianhydride-terminated polyimide resin was 100% (FT-IR).

<Polymerization of PI [[a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] / [a-ODPA (60.0 mol%) / 4,4'-ODA (33.3 mol%)]]>
Amine-terminated polyimide resin [a-ODPA (40.0 mol%) / x22-9409 (66.7 mol%)] was converted to acid dianhydride-terminated polyimide resin [a-ODPA (60.0 mol%) / 4,4'-ODA (33.3 mol) %)], Washes all with 0.4 g of GBL, and after thorough stirring, 5 g of toluene which is an azeotropic agent of by -product condensed water was added and the internal temperature was raised to 180 ° C. After holding for 5 minutes, water and toluene were removed from the trap , and solution imidization was carried out while stirring at 180 ° C. for 30 minutes to remove water and toluene from the trap to obtain the target substance. The weight average molecular weight (Mw) was 33013, and the number average molecular weight (Mn) was 8724.

[Synthesis Example 1]
< Polymerization of siloxane polyimide resin PI [a-ODPA / x22-9409] >
Diaminosiloxane 64.96 g (48.48 mmol, manufactured by Shin-Etsu Chemical Co., Ltd., product name x22-9409, amine value 670) and GBL 20 g were put into a 500 mL separable flask provided with a nitrogen introduction tube and a Dean-Stark trap, and stirred well. Then, 15.04 g (48.48 mmol) of a-ODPA which is an acid dianhydride monomer was gradually added. To this dispersion is added 5 g of toluene, which is an azeotropic agent of by -product condensed water , the internal temperature is raised to 180 ° C. and held for 30 minutes, and then water and toluene are removed from the trap and 180 minutes for 180 minutes. Solution imidization was carried out while removing water and toluene from the trap by stirring at ° C. to produce a homopolymer polyimide resin represented by the following formula (9).

[Synthesis Example 2]
< Polymerization of aromatic polyimide resin PI [a-ODPA / BAPP] >
BAPP 25.62 g (62.46 mmol) and GBL 55 g were put into a 500 mL separable flask provided with a nitrogen introduction tube and a Dean-Stark trap, dissolved completely, and 19.36 g (62.46 mmol) of a-ODPA was gradually dissolved. Added to. To this dispersion is added 5 g of toluene, which is an azeotropic agent of by -product condensed water , the internal temperature is raised to 180 ° C. and held for 30 minutes, and then water and toluene are removed from the trap and 180 minutes for 180 minutes. Solution imidization was carried out while removing water and toluene from the trap by stirring at ° C. to produce a homopolymer polyimide resin represented by the following formula (10).

[Comparative Example 1]
<Blend>
10 g of each of the polyimide resin varnishes obtained in Synthesis Example 1 and Synthesis Example 2 were weighed, and using an appropriate amount of Zr stirring beads having a diameter of 5 mm, a planetary stirring device (2000 rpm, rotation / revolution ratio = 2: 5) manufactured by Shinky Co., Ltd. ).

[Comparative Example 2]
<Polymerization of random copolymer PI [a-ODPA / x22-9409, BAPP] >
Diaminosiloxane 79.98 g (59.69 mmol, manufactured by Shin-Etsu Chemical Co., Ltd., product name x22-9409, amine value 686), BAPP 12.25 g (29.85 mmol) into a 500 mL separable flask provided with a nitrogen introduction tube and a Dean-Stark trap ), 80 g of GBL were added, and after stirring well, 27.78 g (89.54 mmol) of a-ODPA was gradually added. To this dispersion was added 30 g of toluene, which is an azeotropic agent of by -product condensed water , the internal temperature was raised to 180 ° C., held for 30 minutes, and then water and toluene were removed from the trap, followed by 180 minutes for 180 minutes. Solution imidization was carried out while removing water and toluene from the trap by stirring at ° C. to obtain a uniform solution of a random copolymer represented by the following formula (11).

[Molecular weight measurement]
A portion of the amine-terminated polyimide resin of Examples 1-3 (polyimide resin A), acid dianhydride-terminated polyimide resin (polyimide resin B), siloxane-modified block polyimide resin, and random copolymer of Comparative Example 2 were extracted. These were each diluted to 0.5 wt% with THF (tetrahydrofuran) and analyzed by GPC (Gel Permeation Chromatography) system (Shodex GPC system-21 manufactured by Showa Denko KK). Average molecular weight (Mw), number average molecular weight (Mn), and polydispersity (Mw / Mn) were measured. The reduced viscosity (ηred) of the siloxane-modified block polyimide resin of Example 3 and the random copolymer of Comparative Example 2 was measured. Columns (KF-G, KF-606, KF-605, KF-604, KF-601, KF-600D) were calibrated with standard polystyrene at a temperature of 40 ° C. and a flow rate of 1 mL / min.

  In Table 1, the GPC measurement result of the amine terminal polyimide (polyimide A) of Examples 1-3 and an acid dianhydride terminal polyimide (polyimide B) is shown. Table 2 shows the GPC measurement results of the siloxane-modified block polyimide resins of Examples 1 to 3 and the random copolymer of Comparative Example 2.

  FIG. 4 is a GPC chart of polyimide resins of Examples 1 to 3 and Comparative Example 2. The GPC chart of the block polyimide resin of Examples 1 to 3 and the GPC chart of the random polymer of Comparative Example 2 were almost the same. In addition, a small peak is observed at a retention time of 21.5 min regardless of the block size. This is considered to be because siloxane having no functional group was contained in the monomer.

[Measurement of elastic modulus, etc.]
The sample of Example 3 and Comparative Example 2 (length 30 mm, width 10 mm, thickness 50 μm) was mounted on a dynamic viscoelasticity measuring apparatus (DMA-Q800 manufactured by TA Instruments), and the temperature rising rate was 5 ° C./min. The storage elastic modulus (E ′) and loss elastic modulus (E ″) in the temperature range of −100 to 200 ° C. were measured. Also, tan δ (loss elastic modulus / storage elastic modulus obtained under the measurement condition of a frequency of 10 MHz was measured. ) Was the glass transition temperature (Tg).

  FIG. 5 shows the DMA curve (a) of the polyimide resin of Example 3 and the DMA curve (b) of the polyimide resin of Comparative Example 3. The storage elastic modulus E ′ of both was constant at about 2 GPa at −30 ° C. or lower. This is probably because the siloxane segment was frozen at -30 ° C or lower. Moreover, since the polyimide resin of Example 3 has a lower storage elastic modulus (E ′) at room temperature than the random copolymer of Comparative Example 2, the amount of the crosslinking agent added to the polyimide resin of Example 3 is increased. It can be seen that characteristics such as elastic modulus, chemical resistance and glass transition temperature can be greatly controlled.

Further, thermogravimetric analysis (TGA) was used and measured at a heating rate of 10 ° C./min in a nitrogen atmosphere or an air atmosphere, and the 5% weight loss temperature was defined as the thermal decomposition temperature (T _d ⁵ ). Further , the glass transition temperature (Tg) was measured under a nitrogen atmosphere by thermomechanical analysis (TMA) .

Further, using a tensile tester (Tensilon UTM-II manufactured by Toyo Baldwin) at a tensile speed of 8 mm / min, samples of Example 3 and Comparative Example 2 (length 30 mm, width 10 mm, thickness 50 μm) ) Tensile elastic modulus (E), elongation at break (ε _b ), and tensile strength (σ _b ).

  Table 3 shows the measurement results of Example 3 and Comparative Example 3.

[Characteristic evaluation]
Next, for Examples 1 to 3, Synthesis Examples 1 and 2, and Comparative Examples 1 and 2, the state of the polymerization solution, the internal phase separation state when formed into a film, the phase separation structure, and the tack were evaluated.

  The state of the polymerization solution was visually confirmed after standing for 14 days at room temperature after polymerization. Here, the liquid with no unevenness in the solution was evaluated as “uniformly transparent”. Moreover, although there was no nonuniformity in the solution, the cloudy state was evaluated as “uniform turbidity”. The state where the solution was separated into two layers was evaluated as “liquid separation”.

  When the film was formed, the internal phase separation state was such that the polymerization solution was cast onto a glass plate with a doctor blade and dried in a forced convection oven at 100 ° C. for 10 minutes. At this time, a case where severe liquid separation occurred and casting was impossible was evaluated as “film formation impossible”. After drying, it was baked at 200 ° C. for 1 hour in a vacuum oven. The obtained film was peeled off from the glass plate and frozen in liquid nitrogen, then the cross section was cut and observed with a metallographic microscope and a scanning electron microscope (SEM). At this time, the case where the film was too soft to be peeled off from the glass substrate was evaluated as “unpeelable”.

  The phase separation structure was observed by spot element analysis using an energy dispersive X-ray fluorescence analyzer (EXD) for a sample whose cross section could be observed by SEM. By monitoring silicon, it was determined whether the phase forming the phase separation was siloxane PI or aromatic PI.

  Tack stretched the film obtained by baking at 200 degreeC for 1 hour to the glass surface, and evaluated the adhesion | attachment degree in 6 steps, 0-5. 0 indicates no tack at all, and 5 indicates a very strong tack, and the value between them is evaluated numerically.

  Table 4 shows the evaluation results. 6 to 8 are schematic diagrams of a metal micrograph, an SEM photograph, and a phase separation structure of the film of Example 1, respectively. Moreover, FIGS. 9-11 is the schematic diagram of the metal micrograph of a film of Example 2, a SEM photograph, and a phase-separation structure, respectively.

  In the case of the conventional polymer blend as in Comparative Example 1, in the case of this reaction system, liquid separation occurs instantaneously and film formation by casting is impossible. Further, the homopolyimide resin of Synthesis Example 1 was expected to have a solid content concentration of 80% or more in a γ-butyrolactone solvent and excellent printing characteristics, but the film was soft and the glass transition temperature was below room temperature. Filming was difficult. Moreover, since the homopolyimide resin of Synthesis Example 2 has a high glass transition temperature and a high elastic modulus, there is a concern about an increase in repulsive force when used as an FPC coverlay.

Since Comparative Example 2 was obtained by random copolymerization of α-ODPA, which is a polyimide resin component, and siloxane and BAPP, it was possible to form a film, but the properties of both polyimide resins were averaged and tackiness was improved. It was not expensive.

  In Examples 1 to 3 and Comparative Example 2, the composition ratio of all monomers constituting the polyimide resin was the same, but it was found that the state of the polymerization solution, the phase separation state of the film, and the tackiness were different. That is, in Examples 1 to 3, characteristics (such as increased tackiness) that were not found in the random copolymer of Comparative Example 2 were developed. This is considered to be a result of changing the phase separation structure by a block operation in which a heterogeneous polymer is formed and both polymers are polymerized while leaving a terminal active group.

  For example, in the number average molecular weight of polyimide A shown in Table 1, the tack force improved as the number average molecular weight of 4000 or more increased. Further, from the phase separation structure of Example 1 shown in FIGS. 6 to 8 and the phase separation structure of Example 2 shown in FIGS. 9 to 11, the island of aromatic polyimide in the sea-island structure is smaller in Example 1, It turns out that tack power is large.

[Screen printability]
FIG. 12 is a schematic diagram showing a screen printing test pattern. To the polyimide resin varnish of Example 3 having a solid concentration of 60%, 10 phr of a thixotropy adjusting agent (Nippon Aerosil Co., Ltd., Aerosil RY200) was added. This was coated at intervals of 400 μm space and 600 μm PI line, and then dried at 100 ° C. for 10 minutes. Observation with an optical microscope revealed that the screen printability was good.

  Similarly, 15 phr of thixotropic modifier (Aerosil RY200, manufactured by Nippon Aerosil Co., Ltd.) was applied to the polyimide resin varnish of Example 4 having a solid content concentration of 55% and the polyimide resin varnish of Example 5 having a solid content concentration of 60%. When 175 ppm of a foaming agent (manufactured by Shin-Etsu Chemical Co., Ltd., FA-600) was added and the screen printability was confirmed, the same good printability as in Example 3 was confirmed.

Claims (7)

A first activity comprising an acid anhydride group or an amino group by reacting at least one acid dianhydride selected from general formulas (1) to (3) with an aromatic diamine represented by general formula (4). Synthesizing at least one hard segment having end groups;
A second active terminal comprising an acid anhydride group or an amino group by reacting at least one acid dianhydride selected from general formulas (1) to (3) with a diaminosiloxane represented by general formula (5). Synthesizing at least one soft segment having a group;
A method for producing a polyimide resin, wherein at least one hard segment having the first active terminal group and at least one soft segment having the second active terminal group are imidized.

(Wherein R ₁ and R ₂ are each independently absent or represent hydrogen, methyl group, trifluoromethyl group, and X is C═O, SO ₂ , S, O, C, or directly And each benzene ring may be substituted with a halogen, an alkyl group, or an alkoxy group.)

(Wherein R _{1 to} R ₆ each independently does not exist or represents hydrogen, a methyl group, or a trifluoromethyl group, and Y ₁ , Y _2, and Z each independently represent C═O, SO ₂ , S, O, C, or a direct bond, and each benzene ring may be substituted with a halogen, an alkyl group, a hydroxyl group, or an alkoxy group, and m is 0 or 1. .)

(In the formula, R ₁ and R ₈ each independently represents an alkylene group having 1 to 4 carbon atoms or a phenylene group, which may have a substituent. _{2 to} R ₇ each independently represents a monovalent organic group selected from a hydrocarbon having 1 or more carbon atoms, an aliphatic group, or an aromatic group, and n is an integer of 1 or more.   The number average molecular weight of the said soft segment is 4000 or more, The manufacturing method of the polyimide resin of Claim 1.   The method for producing a polyimide resin according to claim 1, wherein the number average molecular weight of the hard segment is 2000 or more.   The polyimide resin obtained with the manufacturing method of any one of Claims 1 thru | or 3.   The polyimide resin according to claim 4, which has a phase separation structure.   The polyimide resin according to claim 4 or 5, which is in the form of a film. At least one acid dianhydride selected from the general formulas (1) to (3) and at least one diamine selected from the general formulas (4) and (5) are reacted to form an acid anhydride group or amino group. Synthesizing at least one segment having a first active end group of groups;
At least one acid dianhydride selected from the general formulas (1) to (3) and at least one diamine selected from the general formulas (4) and (5) are reacted to form an acid anhydride group or amino group. Synthesizing at least one segment having a second active end group of groups;
A method for producing a polyimide resin, wherein at least one segment having the first active terminal group and at least one segment having the second active terminal group are imidized.

(Wherein R ₁ and R ₂ are each independently absent or represent hydrogen, methyl group, trifluoromethyl group, and X is C═O, SO ₂ , S, O, C, or directly And each benzene ring may be substituted with a halogen, an alkyl group, or an alkoxy group.)

(Wherein R _{1 to} R ₆ each independently does not exist or represents hydrogen, a methyl group, or a trifluoromethyl group, and Y ₁ , Y _2, and Z each independently represent C═O, SO ₂ , S, O, C, or a direct bond, and each benzene ring may be substituted with a halogen, an alkyl group, a hydroxyl group, or an alkoxy group, and m is 0 or 1. .)

(In the formula, R ₁ and R ₈ each independently represents an alkylene group having 1 to 4 carbon atoms or a phenylene group, which may have a substituent. _{2 to} R ₇ each independently represents a monovalent organic group selected from a hydrocarbon having 1 or more carbon atoms, an aliphatic group, or an aromatic group, and n is an integer of 1 or more.

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