JP2013007003A - Method for producing polyimide resin particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for stably obtaining amido group-containing polyimide resin particles.SOLUTION: In the method for producing polyimide resin particles in which polyimide resin particles are deposited from a polyimide solution, the polyimide solution includes a polyimide resin having an amide group in the main chain skeleton, and the polyimide resin particles are deposited by adding at least a carboxylic acid and an alcohol as poor solvents to the polyimide solution which is in a state kept at a temperature of 40-80°C.

Description

  The present invention relates to a production method in which a polyimide resin poor solvent is added to a polyimide solution to deposit polyimide resin particles.

  Polyimide resins are widely used as electronic materials because of their excellent heat resistance, electrical insulation, and solvent resistance. However, due to its excellent solvent resistance, it may be difficult to carry out the molding process. Until now, it has been common to apply a polyamic acid as a precursor and use it as a film form.

  In recent years, there has been a change in the manufacturing method of electronic materials, and there is a demand for the development of solution-type heat-resistant materials that can be applied to various substrates, not films, and polyimide resins that are soluble in organic solvents. Development is under consideration. Since the polyimide resin is soluble in the solvent, the degree of freedom of processing is dramatically improved. It is also possible to select a suitable solvent depending on the application. Furthermore, development of a material exhibiting thermal stability and low thermal expansion characteristics is required, and development of a polyimide resin having a soluble and rigid structure has been studied. However, it is not easy to make polyimide resin particles, especially in the case of a rigid structure, if the resin is simply put into a poor solvent, the resin will not become powder but become a lump or gel. May end up. Such a mass of polyimide resin is very hard and is not easy to grind after the fact. Furthermore, there is a problem that the auxiliary raw material, the solvent and the like used during the polymerization are taken into the lump and mixed as impurities when used later.

  Several methods for producing soluble polyimide resin particles are known, but the method for producing polyimide resin particles is to deposit using a change in solubility when modified from polyamic acid to polyimide. It has not been studied to arbitrarily control the shape of the powder by manipulating conditions (Patent Document 1). As a method for producing a polyimide resin, a method for producing a polyimide resin with a controlled particle size by controlling the addition method of a poor solvent has been reported, but the process is complicated and suitable for industrial production. No (Patent Document 2). Although a method of heating a solution and adding a poor solvent has been reported, this method is suitable for a structure in which the polyimide resin is bent, and is suitable for a polyimide resin having a rigid structure in which the poor solvent is used. (Patent Document 3).

Moreover, although the amide group containing soluble polyimide resin which is excellent in a thermal characteristic is known, the manufacturing method of a resin particle is hardly described (patent document 4).
Japanese Patent No. 3596284 JP 2008-81718 A Japanese Patent Laid-Open No. 9-77868 JP 2010-106225 A

  This invention is made | formed in view of the said subject which a prior art has, and it aims at providing the manufacturing method for obtaining the amide group containing polyimide resin particle stably.

  In a polyimide resin having an amide group in the main chain skeleton, polyimide resin particles having a stably controlled particle diameter cannot be obtained by the conventional method due to the presence of the amide group. Therefore, as a result of intensive studies, it was found that the problem can be solved by controlling the temperature of the polyimide solution and using a poor solvent based on a combination of specific solvents.

  The present invention has the following configuration.

  1. A production method for depositing polyimide resin particles from a polyimide solution, wherein the polyimide solution contains a polyimide resin having an amide group in the main chain skeleton, and the polyimide solution is kept at a temperature of 40 ° C. to 80 ° C. A method for producing polyimide resin particles, comprising adding at least carboxylic acid and alcohol as a solvent to precipitate polyimide resin particles.

  2. 1. The addition amount of the poor solvent is by weight with respect to the polyimide resin, the carboxylic acid is 2 to 10 times, and the alcohol is 2 to 20 times. The manufacturing method of the polyimide resin particle of description.

  3. The polyimide resin is represented by the general formula (1). Or 2. The manufacturing method of the polyimide resin particle of description.

(Af represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group)
4). 2. Af represented by the general formula (1) is represented by the following general formula (2). The manufacturing method of the polyimide resin particle of description.

(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR _Two groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom and an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4)
5. Above 1. ~ 4. A polyimide resin particle produced by the production method according to any one of the above, wherein the residual solvent in the resin is 1% by weight or less based on the resin.

  According to the present invention, it is possible to obtain polyimide resin particles whose particle diameter is stably controlled. Therefore, for example, it can be used by dissolving it in a suitable organic solvent or the like, and the amount of impurities to be mixed can be reduced. It is particularly useful when used in electronic material applications.

  A production method for depositing polyimide resin particles from a polyimide solution, wherein the polyimide solution contains a polyimide resin having an amide group in the main chain skeleton, and the polyimide solution is kept at a temperature of 40 ° C. to 80 ° C. It is a method for producing polyimide resin particles, wherein at least carboxylic acid and alcohol are added as a solvent to precipitate polyimide resin particles. According to this method, the obtained polyimide resin does not become a lump, and a resin with good subsequent processability can be obtained without performing operations such as crushing a strong lump later. In addition, it is possible to reduce the incorporation of auxiliary materials and solvents used during polymerization into the polyimide resin particles, and as a result, the content of impurities can be reduced.

  The method for producing a polyimide resin of the present invention comprises polymerizing polyamic acid as a polyimide precursor, then adding a dehydration catalyst and an imidizing agent, completing imidization in an imidization reaction solvent, and then imidization reaction solvent. It is a production method in which a poor solvent is added to obtain a polyimide resin. In the present specification, the expression “polyimide solution” includes “imidation reaction liquid”.

  The method for producing polyimide resin particles of the present invention can be effectively used not only for polyimides containing not only imide groups as polyimides but also for rigid skeletons having amide groups.

  The polyimide resin of the present invention is preferably a polyimide resin represented by the general formula (1) in that the thermal characteristics, particularly the linear thermal expansion coefficient when formed into a film can be lowered.

(Af represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group)
It is more preferable in terms of thermal characteristics that Af represented by the general formula (1) is represented by the following general formula (2).

(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR _Two groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom and an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4)
In the general formula (2), the fluorine atom may be contained in D or E, but in order to obtain a rigid polymer structure, the fluorine atom is preferably contained in E. That is, m is preferably an integer of 1 to 4. E is preferably a fluorine atom or a trifluoromethyl group from the viewpoint of availability.

  Since the above formula (1) has an amide bond, a diamine is generally used as a starting material for Af. The diamine used is 1,4-diamino-2-fluorohensen, 1,4-diamino-2,3-difluorobenzene, 1,4-diamino-2,5-difluorobenzene, 1,4-diamino- 2,6-difluorobenzene, 1,4-diamino-2,3,5-trifluorobenzene, 1,4-diamino, 2,3,5,6-tetrafluorobenzene, 1,4-diamino-2- ( Trifluoromethyl) hensen, 1,4-diamino-2,3-bis (trifluoromethyl) benzene, 1,4-diamino-2,5-bis (trifluoromethyl) benzene, 1,4-diamino-2, 6-bis (trifluoromethyl) benzene, 1,4-diamino-2,3,5-tris (trifluoromethyl) benzene, 1,4-diamino, 2,3,5,6-tetrakis (to Fluoromethyl) benzene, 2-fluorobenzidine, 3-fluorobenzidine, 2,3-difluorobenzidine, 2,5-difluorobenzidine, 2,6-difluorobenzidine, 2,3,5-trifluorobenzidine, 2,3, 6-trifluorobenzidine, 2,3,5,6-tetrafluorobenzidine, 2,2′-difluorobenzidine, 3,3′-difluorobenzidine, 2,3′-difluorobenzidine, 2,2 ′, 3-tri Fluorobenzidine, 2,3,3'-trifluorobenzidine, 2,2 ', 5-trifluorobenzidine, 2,2', 6-trifluorobenzidine, 2,3 ', 5-trifluorobenzidine, 2,3 ', 6, -trifluorobenzidine, 2,2', 3,3'-tetrafluorobenzidine, 2,2 ', 5 '-Tetrafluorobenzidine, 2,2', 6,6'-tetrafluorobenzidine, 2,2 ', 3,3', 6,6'-hexafluorobenzidine, 2,2 ', 3,3', 5 , 5 ′, 6,6′-octafluorobenzidine, 2- (trifluoromethyl) benzidine, 3- (trifluoromethyl) benzidine, 2,3-bis (trifluoromethyl) benzidine, 2,5-bis (tri Fluoromethyl) benzidine, 2,6-bis (trifluoromethyl) benzidine, 2,3,5-tris (trifluoromethyl) benzidine, 2,3,6-tris (trifluoromethyl) benzidine, 2,3,5 , 6-Tetrakis (trifluoromethyl) benzidine, 2,2′-bis (trifluoromethyl) benzidine, 3,3′-bis (trifluoromethyl) benzidine Gin, 2,3′-bis (trifluoromethyl) benzidine, 2,2 ′, 3-bis (trifluoromethyl) benzidine, 2,3,3′-tris (trifluoromethyl) benzidine, 2,2 ′, 5-tris (trifluoromethyl) benzidine, 2,2 ′, 6-tris (trifluoromethyl) benzidine, 2,3 ′, 5-tris (trifluoromethyl) benzidine, 2,3 ′, 6, -tris ( Trifluoromethyl) benzidine, 2,2 ′, 3,3′-tetrakis (trifluoromethyl) benzidine, 2,2 ′, 5,5′-tetrakis (trifluoromethyl) benzidine, 2,2 ′, 6,6 Examples include, but are not limited to, '-tetrakis (trifluoromethyl) benzidine.

  Next, B in the general formula (1) of the present invention will be described.

  Any structure can be used as the structure of B in the general formula (1). Specific examples of diamine monomers that can be used include, for example, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenylsulfide, 3,4′-diaminodiphenylsulfide, 4,4′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′- Diaminodiphenyl sulfone, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,4′-diamino Diphenylmethane, 2, 2 Di (3-aminophenyl) propane, 2,2-di (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 1,1-di (3-amino) Phenyl) -1-phenylethane, 1,1-di (4-aminophenyl) -1-phenylethane, 1- (3-aminophenyl) -1- (4-aminophenyl) -1-phenylethane, 1, 3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminobenzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4- Minobenzoyl) benzene, 1,3-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (3 -Amino-α, α-dimethylbenzyl) benzene, 1,4-bis (4-amino-α, α-dimethylbenzyl) benzene, 2,6-bis (3-aminophenoxy) benzonitrile, 2,6-bis (3-aminophenoxy) pyridine, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, Bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl ] Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- ( 4-aminophenoxy) phenyl] ether, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1 , 4-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) -α, α-dimethyl Rubenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] Benzene, 1,4-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 4,4′-bis [4- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′- Bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4 ′ -Bis [4- (4-aminophenoxy) phenoxy] diphenylsulfone, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3'-diamino-4,4'-di Biphenoxybenzophenone, 3,3′-diamino-4-phenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 6,6′-bis (3-aminophenoxy) -3,3,3 ′, 3 '-Tetramethyl-1,1'-spirobiindane, 6,6'-bis (4-aminophenoxy) -3,3,3', 3'-tetramethyl-1,1'-spirobiindane, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis (3- Aminobutyl) polydimethylsiloxane, bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis (2-amino) Toxi) ethyl] ether, bis [2- (2-aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2- Bis (2-aminoethoxy) ethane, 1,2-bis [2- (aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-amino Propyl) ether, diethylene glycol bis (3-aminopropyl) ether, triethylene glycol bis (3-aminopropyl) ether, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1 , 6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1, -Diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, trans-1,4 -Diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohex Xyl) methane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 1,4-diamino-2- Fluorohensen, 1,4-diamino-2,3-difluorobenzene, 1,4-diamino-2,5-difluoroben Zen, 1,4-diamino-2,6-difluorobenzene, 1,4-diamino-2,3,5-trifluorobenzene, 1,4-diamino, 2,3,5,6-tetrafluorobenzene, , 4-diamino-2- (trifluoromethyl) hensen, 1,4-diamino-2,3-bis (trifluoromethyl) benzene, 1,4-diamino-2,5-bis (trifluoromethyl) benzene, 1,4-diamino-2,6-bis (trifluoromethyl) benzene, 1,4-diamino-2,3,5-tris (trifluoromethyl) benzene, 1,4-diamino, 2,3,5 6-tetrakis (trifluoromethyl) benzene, 2-fluorobenzidine, 3-fluorobenzidine, 2,3-difluorobenzidine, 2,5-difluorobenzidine, 2,6-diph Orobenzidine, 2,3,5-trifluorobenzidine, 2,3,6-trifluorobenzidine, 2,3,5,6-tetrafluorobenzidine, 2,2'-difluorobenzidine, 3,3'-difluorobenzidine 2,3'-difluorobenzidine, 2,2 ', 3-trifluorobenzidine, 2,3,3'-trifluorobenzidine, 2,2', 5-trifluorobenzidine, 2,2 ', 6-tri Fluorobenzidine, 2,3 ′, 5-trifluorobenzidine, 2,3 ′, 6, -trifluorobenzidine, 2,2 ′, 3,3′-tetrafluorobenzidine, 2,2 ′, 5,5′- Tetrafluorobenzidine, 2,2 ′, 6,6′-tetrafluorobenzidine, 2,2 ′, 3,3 ′, 6,6′-hexafluorobenzidine, 2,2 ′, 3 ', 5,5', 6,6'-octafluorobenzidine, 2- (trifluoromethyl) benzidine, 3- (trifluoromethyl) benzidine, 2,3-bis (trifluoromethyl) benzidine, 2,5- Bis (trifluoromethyl) benzidine, 2,6-bis (trifluoromethyl) benzidine, 2,3,5-tris (trifluoromethyl) benzidine, 2,3,6-tris (trifluoromethyl) benzidine, 2, 3,5,6-tetrakis (trifluoromethyl) benzidine, 2,2′-bis (trifluoromethyl) benzidine, 3,3′-bis (trifluoromethyl) benzidine, 2,3′-bis (trifluoromethyl) ) Benzidine, 2,2 ′, 3-bis (trifluoromethyl) benzidine, 2,3,3′-tris (trifluoromethyl) Benzidine, 2,2 ′, 5-tris (trifluoromethyl) benzidine, 2,2 ′, 6-tris (trifluoromethyl) benzidine, 2,3 ′, 5-tris (trifluoromethyl) benzidine, 2,3 ', 6, -tris (trifluoromethyl) benzidine, 2,2', 3,3'-tetrakis (trifluoromethyl) benzidine, 2,2 ', 5,5'-tetrakis (trifluoromethyl) benzidine, , 2 ′, 6,6′-tetrakis (trifluoromethyl) benzidine.

  As a preferable specific example of B, the diamine shown as a specific example of Af is used.

  Depending on the desired physical properties, other tetracarboxylic dianhydrides and diamines can be used. The repeating unit of the polyimide of the present invention represented by the general formula (1) is selected depending on the balance between the solubility and the low linear thermal expansion coefficient, but is 30 mol% or more of the whole polymer, preferably 50 mol% or more, More preferably, it contains 70 mol% or more. Moreover, the repeating unit of the said General formula (1) may be regularly arranged, and may exist in a polyimide at random.

  Examples of other tetracarboxylic dianhydrides that can be used in combination other than the repeating unit of the general formula (1) include, for example, ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, and cyclobutanetetracarboxylic dianhydride. , Cyclopentanetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 3,3 ′ , 4,4'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride Bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarbohydrate) Ciphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) ) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoro Propane dianhydride, 1,3-bis [(3,4-dicarboxy) benzoyl] benzene dianhydride, 1,4-bis [(3,4-dicarboxy) benzoyl] benzene dianhydride, 2,2 -Bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} propane dianhydride, 2,2-bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} propane Anhydride, bis {4- [4- 1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, 4,4′-bis [4- ( 1,2-dicarboxy) phenoxy] biphenyl dianhydride, 4,4′-bis [3- (1,2-dicarboxy) phenoxy] biphenyl dianhydride, bis {4- [4- (1,2- Dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} ketone dianhydride, bis {4- [4- (1,2-dicarboxy) ) Phenoxy] phenyl} sulfone dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfone dianhydride, bis {4- [4- (1,2-dicarboxy) phenoxy ] Phenyl} Rufido dianhydride, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide dianhydride, 2,2-bis {4- [4- (1,2-dicarboxy) phenoxy] Phenyl} -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} -1,1, 1,3,3,3-propane dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 1,2,5 , 6-Naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7 Anthracene tetracarboxylic dianhydride, 1,2,7 8-phenanthrene tetracarboxylic acid dianhydride and the like, but not limited thereto. These may be used alone or in combination of two or more.

  As other diamines other than the repeating unit of the general formula (1) that can be used in combination, the equivalent diamine described in B of the general formula (1) is used.

  The organic solvent used for the polymerization of the polyamic acid is not particularly limited as long as it does not react with the tetracarboxylic dianhydride and diamine to be used and can dissolve the polyamic acid that is the precursor. For example, urea solvents such as methylurea, N, N-dimethylethylurea, sulfoxide or sulfone solvents such as dimethyl sulfoxide, diphenylsulfone, and tetramethylsulfone, N, N-dimethylformamide (DMF), N, N Amide solvents such as dimethylacetamide (DMAc), N, N′-diethylacetamide, N-methyl-2-pyrrolidone (NMP), γ-butyllactone, hexamethylphosphoric triamide, halogens such as chloroform and methylene chloride Alkyl ether solvents, benzene, toluene and other aromatic hydrocarbon solvents, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, dimethyl ether, diethyl ether, p-cresol methyl ether and other ether solvents. Can Usually it may be used in combination of two or more as needed or use these solvents alone. From the viewpoints of solubility and reactivity of the polyamic acid, DMF, DMAc, NMP and the like are preferably used.

  As a method for converting a polyamic acid as a precursor into a polyimide, there is a method in which a polyamic acid varnish obtained by adding a dehydration catalyst and an imidizing agent to polyamic acid is imidized in a reaction solvent.

  A tertiary amine can be used as the imidizing agent. As the tertiary amine, a heterocyclic tertiary amine is more preferable. Preferable specific examples of the heterocyclic tertiary amine include pyridine, picoline, quinoline, isoquinoline and the like. Specific examples of preferred acid anhydrides include acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, trifluoroacetic anhydride, and the like.

  As the amount of the imidizing agent or dehydration catalyst added, the imidizing agent is 0.5 to 5.0 times molar equivalent, more preferably 0.7 to 2.5 times molar equivalent, especially the amide group of the polyamic acid. Is preferably 0.8 to 2.0 times molar equivalent. The dehydration catalyst is preferably 0.5 to 10.0 times molar equivalent, more preferably 0.7 to 5.0 times molar equivalent, and particularly preferably 0.8 to 3.0 times molar equivalent.

  When an imidizing agent or a dehydration catalyst is added to the polyamic acid solution, it may be added directly without being dissolved in a solvent, or a solution dissolved in a solvent may be added. In the direct addition method, the reaction may rapidly proceed before the imidizing agent or the dehydration catalyst diffuses to form a gel. Preferably, the imidizing agent and the dehydration catalyst are dissolved in a solvent, and the solution is mixed with the polyamic acid solution.

  A method for obtaining a polyimide resin by introducing a poor solvent into an imidization reaction solvent will be described.

  As the poor solvent used in the present invention, two or more kinds of solvents which are miscible with the organic solvent contained in the polyimide solution, are poor with respect to the polyimide resin, and have different solubility with respect to the resin are used. Can do. The solvent species are preferably two or more solvents each selected from one or more of carboxylic acid and alcohol. As a poor solvent for obtaining polyimide resin particles, alcohol is generally preferably used because of its high versatility, but in the polyimide resin containing an amide group as in the present invention, the alcohol alone is a resin. Aggregation occurs between them, and it is difficult to obtain good resin particles. By using carboxylic acid in combination as a poor solvent, aggregation of amide groups and imide groups can be prevented, and good resin particles can be obtained to form a lump. In addition, although it is possible to obtain resin particles only with carboxylic acid, since the solubility in the resin is higher than that of alcohol, the precipitation ability is not sufficient, and the yield may be deteriorated. A solvent amount is required, which is not preferable. The amount of the poor solvent to be added is preferably 5 to 20 times the weight of the resin. If the amount is 5 times or less, a sufficient yield may not be secured, which is not preferable. When the amount is 20 times or more, the amount of the solvent is considerably large relative to the resin that can be obtained, which is not preferable from the viewpoint of productivity. The addition amount of the carboxylic acid is preferably 2 to 10 times by weight with respect to the polyimide resin in order to sufficiently develop the aggregation effect of the polyimide resin, and 3 to 5 times from the viewpoint of productivity. More preferably. The amount of alcohol added is preferably 2 to 20 times by weight from the viewpoint of securing a sufficient yield, and particularly preferably 5 to 15 times from the viewpoint of productivity. The addition of the poor solvent to the imidation reaction solution is a method of adding a carboxylic acid first and then adding an alcohol or a method of previously mixing a carboxylic acid and an alcohol and adding the mixed solvent to the imidation reaction solution. preferable. The carboxylic acid to be used is not particularly limited, but a chain monocarboxylic acid is preferable, and acetic acid is most preferable from the viewpoints of availability and ease of drying after isolation. Examples of the alcohol used include methyl alcohol, ethyl alcohol, 2-propyl alcohol, ethylene glycol, triethylene glycol, 2-butyl alcohol, 2-hexyl alcohol, cyclopentyl alcohol, cyclohexyl alcohol, phenol, and t-butyl alcohol. It is done. Among the above alcohols, alcohols such as 2-propyl alcohol, 2-butyl alcohol, 2-pentyl alcohol, phenol, cyclopentyl alcohol, cyclohexyl alcohol, and t-butyl alcohol are preferable from the viewpoint of the stability of the polyimide resin after isolation, 2-Propyl alcohol is particularly preferable from the viewpoint of ease of drying, which is a subsequent step.

  When the poor solvent is added to the imidization reaction solution, the polyimide resin can be obtained more stably by adding the poor solvent while controlling the temperature. The temperature of the imidization reaction liquid at this time is preferably 40 ° C. or higher and 80 ° C. or lower, more preferably 50 ° C. or higher and 70 ° C. or lower, and particularly preferably 55 ° C. or higher and 65 ° C. or lower. When the temperature is 40 ° C. or lower, the solubility of the polyimide resin is poor, and when a poor solvent is added, the resin is likely to precipitate and may be separated into a lump. On the other hand, if the temperature is 80 ° C. or higher, there is a high possibility that the imidization rate is lowered, which is not preferable. By controlling the temperature as described above, the affinity with the poor solvent can be improved while maintaining the solubility of the polyimide resin in the solution, and good polyimide resin particles can be obtained without becoming a lump. Is possible.

  When the polyimide resin solution is poured into a poor solvent, the solid content concentration of the polyimide resin solution is not particularly limited as long as the viscosity is a stirrable viscosity, but the concentration is dilute from the viewpoint of controlling the particle size. preferable. However, when it is too dilute, a large amount of poor solvent is used to precipitate the polyimide resin, which is not preferable. From these viewpoints, it is preferable that the polyimide solution is poured into the poor solvent solution after dilution so that the solid content concentration of the polyimide resin solution is 15% or less, preferably 10% or less.

  Since the polyimide resin particles obtained here contain a small amount of an imidizing agent or a dehydrating agent, it is preferable to wash several times with the above poor solvent, particularly an alcohol solvent such as 2-propyl alcohol.

  The polyimide resin particles obtained may be dried by vacuum drying or hot air drying. In order to completely dry the solvent contained in the resin, it is desirable to use vacuum drying, and the drying temperature is preferably in the range of 100 to 200 ° C, particularly preferably 120 to 150 ° C.

  The particle diameter of the polyimide resin particles is preferably 1 μm or more and less than 5000 μm from the viewpoint of processability, such as ease of handling, and a process in which the resin particles of the present invention are dissolved in a solvent to obtain a solution, and preferably 2 μm or more and 3000 μm. It is particularly preferred that it is less than. In the present specification, “good resin particles” represent resin particles having a particle size of 1 μm or more and less than 5000 μm.

  Residual solvents such as a small amount of polymerization solvent are present in the polyimide resin particles obtained by the above method. It is very difficult to remove them completely. Since this residual solvent becomes an impurity in the processing from here onward, there is a problem if it is present in a large amount. The amount of residual solvent is preferably 2% by weight or less, and more preferably 1% by weight or less. The amount of residual solvent here represents the ratio of the weight of the remaining solvent to the weight of the resin.

  The polyimide resin of the present invention can be used by, for example, being dissolved in a suitable organic solvent or the like, and the amount of impurities to be mixed can be reduced. It is particularly useful when used in electronic material applications. Solvents that can be used include amide solvents, ether solvents, ketone solvents, ester solvents, glycol ether solvents, and glycol ester solvents. As the amide solvent, N, N-dimethylacetamide or N, N-dimethylformamide is preferably used from the viewpoint of solubility. Further, the solvent other than the amide solvent is preferably a solvent selected from methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, propylene glycol monomethyl ether acetate and methyl triglyme, and the difference in boiling point from the amide solvent It is particularly preferable to use a solvent selected from cyclohexanone, cyclopentanone, and propylene glycol monomethyl ether acetate from the viewpoint of low content. A mixed solvent of an amide solvent and a solvent other than the amide solvent can also be used.

  The polyimide resin particles according to the present invention may be dissolved in, for example, a suitable organic solvent and formed into a film shape, and various inorganic thin films such as metal oxides and transparent electrodes may be formed on the surface thereof. The method for forming these inorganic thin films is not particularly limited, and may be, for example, a PVD method such as a CVD method, a sputtering method, a vacuum deposition method, or an ion plating method.

  The polyimide resin particles according to the present invention have high dimensional stability and high solubility in an organic solvent, in addition to the original properties of polyimide such as heat resistance and insulation, and also have excellent coatability. Fields and products in which these characteristics are effective, for example, printed materials, color filters, flexible display substrates, TFT substrates, optical films and other optical materials, liquid crystal display devices, organic EL, electronic paper and other image display devices, electronic It can be suitably used as a device material or a solar cell, and can be applied as an alternative material for a part where glass is currently used.

(Evaluation method)
The material characteristic values and the like described in the present specification are obtained by the following evaluation methods.

<Measurement of amount of residual solvent in resin>
The resin was dissolved in 1,3-dioxolane at a concentration of 1 wt%, and the residual solvent concentration in this solution was measured by gas chromatography. As the gas chromatography apparatus, Hp6890 series GC System, HP6890 series AutoSampler (manufactured by HEWLETT PACKARD), HG-2500 (manufactured by GL Scuteaces), KAPSEL-CON Ye-3R (manufactured by Yaesaki Air Pressure Co., Ltd.), 3-32 are used. (Manufactured by J & W) was used. The sample injection volume was 2 μl, the inlet temperature was 225 ° C., and the pressure was 9.5 psi. The initial temperature of the oven was 35 ° C., held for 5 minutes, and then heated to 155 ° C. at a rate of temperature increase of 20 ° C./min. The carrier gas was He, the pressure was 9.5 psi, and the flow rate was 2.2 ml / min. The detector was FID, and the H ₂ flow rate was 40 ml / min and the AIR flow rate was 450 ml / min. Calibration curves were prepared for the solvents used during resin synthesis.

(Synthesis Example 1)
<Synthesis of amide group-containing tetracarboxylic dianhydride (following formula (3))>

  A 500 mL glass separable flask equipped with a stirrer equipped with a stainless steel stirring rod equipped with a four-blade stirring blade on a polytetrafluoroethylene sealing stopper and a nitrogen introducing tube, and trimellitic anhydride chloride 67 .4 g was added, and a mixed solvent consisting of 190 g of ethyl acetate and 190 g of n-hexane was added and dissolved to prepare Solution A. Further, 25.6 g of 2,2′-bis (trifluoromethyl) benzidine (hereinafter referred to as TFMB) was dissolved in another container by adding a mixed solvent consisting of 72 g of ethyl acetate and 72 g of n-hexane, and propylene oxide as a deoxidizing agent. Solution B was prepared by adding 9.2 g.

While cooling to about −20 ° C. in an ethanol ice bath, the solution B was added dropwise to the solution A with stirring, followed by stirring for 3 hours, and then stirring at room temperature for 12 hours. The precipitate was separated by filtration and washed well with an ethyl acetate / n-hexane mixed solvent (volume ratio 1: 1). Then, it was separated by filtration and vacuum-dried at 60 ° C. for 12 hours and further at 120 ° C. for 12 hours to obtain a white product with a yield of 70%. FT-IR: 3380 cm ⁻¹ (amide group NH stretching vibration), 3105 cm ⁻¹ (aromatic C—H stretching vibration), 1857 cm ⁻¹ , 1781 cm ⁻¹ (acid anhydride group C═O stretching vibration), 1677 cm ^{− 1} (amide group C═O stretching vibration) peak, and ¹ H-NMR, δ 11.06 ppm (s, NH, 2H), δ 8.65 ppm (s, on phthalimide, 3-position C _arom H, 2H), δ 8.37 ppm (on phthalimide, 5 and 6 position C _arom H, 4H), δ 7.46 ppm (d, on center biphenyl, 6 and 6 ′ position C _arom H, 2H), δ 8.13 ppm (d, on center biphenyl, 5 and 5 _'positions C arom H, 2H), δ8.27ppm (s, on the central biphenyl, 3 and 3' _C arom H, it was possible to confirm the peak of 2H) Et al., It was confirmed that the amide group-containing tetracarboxylic dianhydride represented by the above formula (3) the desired product was obtained. It was 274 degreeC when melting | fusing point of this compound was measured by DSC.

(Synthesis Example 2)
<Synthesis of polyimide solution>
TFMB 9.7 g was placed in a 500 mL glass separable flask equipped with a stirrer equipped with a stainless steel stirring rod equipped with a four-blade stirring blade on a polytetrafluoroethylene sealing stopper and a nitrogen introduction tube, and polymerized. After adding and stirring 153 g of dehydrated DMF as a solvent for use, 20.2 g of the amide group-containing tetracarboxylic dianhydride of Synthesis Example (1) was added to this solution, and after stirring for 10 minutes, 17 g of acetic acid was added, A polyamide-amide acid was obtained by stirring. In addition, the preparation density | concentration of the diamine compound and tetracarboxylic dianhydride in this reaction solution was 15 weight% with respect to all the reaction liquids.

  After stirring for 5 hours, 88 g of DMF was added and stirred, and then 4.8 g of pyridine was added as an imidization catalyst and completely dispersed. 7.4 g of acetic anhydride was added to the dispersed solution and stirred, followed by stirring at 100 ° C. for 4 hours to obtain a polyimide solution.

Example 1
<Manufacture of polyimide resin particles>
While the polyimide solution synthesized in Synthesis Example 2 was heated to 60 ° C. and stirred, 160 g of acetic acid was added in about 10 minutes. Thereafter, 440 g of 2-propyl alcohol (hereinafter referred to as IPA) was added over 30 minutes to precipitate the target polyimide resin particles. Thereafter, the mixture was allowed to cool for 2 hours, and when the liquid temperature reached 25 ° C., it was suction filtered with a Kiriyama funnel and further washed with 300 g of IPA. This washing was repeated 5 times, and suction filtration with a Kiriyama funnel and drying overnight in a vacuum oven set at 120 ° C. gave a good yield of 28.5 g (yield: 95%) and a particle size of 2 to 300 μm. Resin particles were obtained. The residual solvent in the obtained resin particles was DMF: 0.5 wt%, and other solvents were not detected.

(Example 2)
<Manufacture of polyimide resin particles>
While the polyimide solution synthesized in Synthesis Example 2 was heated to 60 ° C. and stirred, 160 g of acetic acid was added in about 10 minutes. Thereafter, a mixed solution of 40 g of acetic acid and 80 g of IPA was added over 20 minutes, and then 280 g of IPA was added over 30 minutes to precipitate the target polyimide resin particles. Thereafter, the mixture was allowed to cool for 2 hours, and when the liquid temperature reached 25 ° C., it was suction filtered with a Kiriyama funnel and further washed with 300 g of IPA. This washing was repeated 5 times, and suction filtration with a Kiriyama funnel was performed overnight in a vacuum oven set at 120 ° C., yielding 28.5 g (yield: 95%) and a particle size of 2 to 200 μm. Resin particles were obtained. The residual solvent in the obtained resin particles was DMF: 0.4 wt%, and other solvents were not detected.

(Comparative Example 1)
<Manufacture of polyimide resin particles>
When 100 g of IPA was added to the polyimide solution synthesized in Synthesis Example 2 while stirring at room temperature, the polyimide resin was agglomerated and phase separated, and particles could not be obtained. Further, IPA500 was added, and suction filtration was performed with a Kiriyama funnel to separate a blocky resin. The mass was cut with scissors and washed with 300 g of IPA. This washing was repeated 5 times, and the product was obtained with a yield of 28.5 g (yield: 95%) by suction filtration with a Kiriyama funnel and drying in a vacuum oven set at 120 ° C. overnight. The residual solvent in the obtained resin particles was DMF: 2.0 wt% and IPA: 0.5 wt%.

(Comparative Example 2)
<Manufacture of polyimide resin particles>
While the polyimide solution synthesized in Synthesis Example 2 was heated to 60 ° C. and stirred, IPA was added. However, when IPA 60 g was added, the polyimide resin became lumpy, and the particle size was 5-20 mm. It became particles. Further, IPA500 was added, and suction filtration was performed with a Kiriyama funnel to separate the hail-like resin. This resin was washed with 300 g of IPA. This washing was repeated 5 times, and the product was obtained with a yield of 28.5 g (yield: 95%) by suction filtration with a Kiriyama funnel and drying in a vacuum oven set at 120 ° C. overnight. The residual solvent in the obtained resin particles was DMF: 1.5 wt% and IPA: 0.5 wt%.

(Comparative Example 3)
<Manufacture of polyimide resin particles>
When the polyimide solution synthesized in Synthesis Example 2 was added over 3 hours while stirring 600 g of IPA, the polyimide resin became fibrous. Suction filtration was performed with a Kiriyama funnel, and the fibrous polyimide resin was cut with scissors and washed with 300 g of IPA. This washing was repeated 5 times, and the product was obtained in a yield of 25.0 g (yield: 83%) by suction filtration with a Kiriyama funnel and drying in a vacuum oven set at 120 ° C. overnight. The residual solvent in the obtained resin particles was DMF: 2.5 wt% and IPA: 0.5 wt%.

Claims (5)

A production method for depositing polyimide resin particles from a polyimide solution, wherein the polyimide solution contains a polyimide resin having an amide group in the main chain skeleton, and the polyimide solution is kept at a temperature of 40 ° C. to 80 ° C. A method for producing polyimide resin particles, comprising adding at least carboxylic acid and alcohol as a solvent to precipitate polyimide resin particles. 2. The method for producing polyimide resin particles according to claim 1, wherein the addition amount of the poor solvent is by weight with respect to the polyimide resin, 2 to 10 times the amount of carboxylic acid, and 2 to 20 times the amount of alcohol. . The said polyimide resin is represented by General formula (1), The manufacturing method of the polyimide resin particle of Claim 1 or 2 characterized by the above-mentioned.

(Af represents a divalent organic group containing an aromatic ring and a fluorine atom, and B represents a divalent organic group) Af represented in the said General formula (1) is represented by following General formula (2), The manufacturing method of the polyimide resin particle of Claim 3 characterized by the above-mentioned.

(D is a single bond, CR ₂ group (where R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R may be different from each other and may form a ring, and the hydrogen atom in the alkyl group and aryl group may be substituted with a fluorine atom), CO group, SO ₂ group, SiR _Two groups (wherein R is as defined above), a functional group selected from an oxygen atom and a sulfur atom, E is a fluorine atom and an organic group containing a fluorine atom, m is an integer of 0 to 4, and l is (It is an integer from 0 to 4) Polyimide resin particles produced by the production method according to claim 1, wherein the residual solvent in the resin is 1% by weight or less based on the resin.