Method for producing polyimide alloy resin powder, polyimide alloy resin powder, molding and method for producing film

Abstract

To provide a method for producing a molding and a film which are excellent in moldability, and have high transparency and sufficient mechanical strength, resin powder which is used for the production, and a method for producing resin powder.SOLUTION: Polyimide alloy resin powder is composed of a polyimide resin and a resin having an ester bond, wherein the glass transition temperature of the polyimide alloy resin powder is 200°C or lower which is different from the glass transition temperatures of the polyimide resin and the resin having the ester bond, the glass transition temperature of the polyimide alloy resin powder exists in a temperature region between the glass transition temperatures of the polyimide resin and the resin having the ester bond, and a 1% weight reduction temperature of the polyimide alloy resin powder is 280°C or higher.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing polyimide alloy resin powder, polyimide alloy resin powder, a method for producing a molded body and a film.

Background Art

[0002] In display devices such as liquid crystals, organic ELs, and electronic papers, and in electronic devices such as solar cells and touch panels, thinning, weight reduction, and further flexibility are required. By replacing the glass material used in these devices with a film material, flexibility, thinning, and weight reduction can be achieved. As a glass alternative material, a transparent polyimide film has been developed and is used for display substrates, cover films, etc.

[0003] A normal polyimide film is obtained by applying a polyamic acid solution, which is a polyimide precursor, in a film form on a support and performing high-temperature treatment to remove the solvent and simultaneously perform thermal imidization. However, the heating temperature for thermal imidization is high (for example, 300°C or higher), and coloring (increase in yellowness) is likely to occur due to heating, making it difficult to apply to applications that require high transparency such as display cover films.

[0004] As a method for producing a polyimide film having high transparency, a method of forming a film by a solvent casting method using a polyimide resin that is soluble in an organic solvent and does not require imidization at a high temperature after film formation has been proposed. As such a solvent-soluble polyimide, a fluorine-containing compound is used from the viewpoint of balancing transparency and mechanical properties. For example, Patent Document 1 describes that a polyimide containing an alicyclic tetracarboxylic dianhydride as a tetracarboxylic dianhydride component and a diamine having a perfluoroalkyl group as a diamine component is soluble in a low-boiling solvent such as methylene chloride. However, the method of dissolving and molding in an organic solvent as in Patent Document 1 has a high environmental load in terms of using an organic solvent. Also, since it is necessary to volatilize the solvent, it is difficult to produce a thick molded body.

[0005] Examples of molding methods without using a solvent include melt extrusion molding and melt injection molding. However, generally, in exchange for its high heat resistance, polyimide has been difficult to process by molding methods such as melt extrusion molding and melt injection molding. In some specific polyimides (AURUM of Mitsui Chemicals), injection molding was possible, but there was a problem that molding was required at a very high temperature of 400 °C or higher and it could not be molded with a normal molding machine. Further, when performing high-temperature molding, since the coloring of the polyimide resin progresses, molding of a polyimide with less coloring and excellent transparency is even more difficult.

[0006] In addition, as a method for improving the properties of the resin, a method of alloying with other resins is also known. Patent Document 1 describes that by forming an alloy of a polyimide resin and an acrylic resin, excellent mechanical strength and transparency can be obtained. Further, the specification of Patent Document 1 describes that polyimide resin powder can be obtained by adding a poor solvent to a solution containing polyimide. However, there is no description of an alloy resin powder of a polyimide resin and an acrylic resin (polyimide alloy resin powder), and no example of obtaining polyimide alloy resin powder is disclosed in the examples, and no findings can be obtained regarding the properties and moldability of the powder obtained by the method described in the specification.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] While polyimide has high heat resistance and high strength, it is inferior in moldability and requires molding at a very high temperature to be molded without a solvent. With conventional transparent polyimide resins, it is not easy to achieve both transparency and moldability while maintaining transparency. In view of such problems, an object of the present invention is to provide a method for producing a molded body and a film that are excellent in moldability, have high transparency, and have sufficient mechanical strength, a resin powder used for the production thereof, and a method for producing the resin powder.

Means for Solving the Problems

[0009] As a result of intensive studies, the present inventors have found that the above problems can be solved by the following configuration.

[0010] 1). A polyimide alloy resin powder composed of a polyimide resin and a resin having an ester bond, The glass transition temperature of the polyimide alloy resin powder is 200 °C or less, which is different from the glass transition temperatures of the polyimide resin and the resin having an ester bond, The glass transition temperature of the polyimide alloy resin powder exists in the temperature range between the glass transition temperatures of the polyimide resin and the resin having an ester bond, A polyimide alloy resin powder in which the 1% weight loss temperature of the polyimide alloy resin powder is 280 °C or higher.

[0011] 2). The melt viscosity of the polyimide alloy resin powder is less than 30 KPa·s at a temperature lower than the 1% weight loss temperature of the polyimide alloy resin powder, The polyimide alloy resin powder according to 1), wherein the glass transition temperature of the resin having an ester bond is 150 °C or less.

[0012] 3). The polyimide alloy resin powder according to 1) or 2), wherein the resin having an ester bond is composed of one or more selected from acrylic resin, polyester resin, polycarbonate resin, and polyarylate resin.

[0013] 4). The polyimide resin has a structure derived from a tetracarboxylic dianhydride component and a structure derived from a diamine component, As the tetracarboxylic dianhydride component, it contains one or more selected from tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(anhydromellitic acid) esters, As the diamine component, it contains one or more of diamines having a benzidine skeleton and diamines having a cardo structure, The polyimide resin is a soluble polyimide resin that dissolves 3 g or more per 100 g of a solvent selected from amide solvents such as N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and N,N-dimethylacetamide (DMAc). The polyimide alloy resin powder according to any one of 1) to 3).

[0014] 5). The polyimide alloy resin powder has only one glass transition temperature, and is the polyimide alloy resin powder according to any one of 1) to 4).

[0015] 6). A step of dissolving a polyimide resin that dissolves 3 g or more per 100 g of a solvent selected from DMF, NMP, and DMAc and a resin having an ester bond in a solvent, A step of mixing the solution in which the polyimide resin and the resin having an ester bond are dissolved with a poor solvent to precipitate a polyimide alloy resin, A method for producing a polyimide alloy resin powder, characterized by having a step of drying the precipitated polyimide alloy resin.

[0016] 7). The method for producing a polyimide alloy resin powder according to 6), characterized in that the solution in which the polyimide resin and the resin having an ester bond are dissolved has a haze of 10 or less in a solution having a solid content concentration of 5 wt%.

[0017] 8). The glass transition temperature of the polyimide alloy resin powder is 200°C or less, which is different from the glass transition temperatures of the polyimide resin and the resin having an ester bond. The glass transition temperature of the polyimide alloy resin powder exists in a temperature range between the glass transition temperatures of the polyimide resin and the resin having an ester bond, The method for producing a polyimide alloy resin powder according to 6) or 7), characterized in that the 1% weight loss temperature of the polyimide alloy resin powder is 280 ° C or higher.

[0018] 9). The melt viscosity of the polyimide alloy resin powder is less than 30 KPa·s at a temperature lower than the 1% weight loss temperature of the polyimide alloy resin powder, The method for producing a polyimide alloy resin powder according to any one of 6) to 8), characterized in that the glass transition temperature of the resin having an ester bond is 150 ° C or lower.

[0019] 10). The method for producing a polyimide alloy resin powder according to any one of 6) to 9), wherein the resin having an ester bond is composed of one or more selected from acrylic resin, polyester resin, polycarbonate resin, and polyarylate resin.

[0020] 11). The polyimide resin has a structure derived from a tetracarboxylic dianhydride component and a structure derived from a diamine component, As the tetracarboxylic dianhydride component, it contains one or more selected from tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(anhydride trimellitic acid) esters, As the diamine component, it contains one or more of diamines having a benzidine skeleton and diamines having a cardo structure. The method for producing a polyimide alloy resin powder according to any one of claims 6) to 10).

[0021] 12). The method for producing a polyimide alloy resin powder according to any one of 6) to 11), characterized in that the polyimide alloy resin powder has only one glass transition temperature.

[0022] 13). A method for manufacturing a molded article, characterized by heating and pressing the polyimide alloy resin powder according to any one of 1) to 5).

[0023] 14). A method for manufacturing a molded article, characterized by heating and pressing the polyimide alloy resin powder produced by the method for producing a polyimide alloy resin powder according to any one of 6) to 12).

[0024] 15). A method for manufacturing a film, characterized by heating and pressing the polyimide alloy resin powder according to any one of 1) to 5).

[0025] 16). A method for manufacturing a film, characterized by heating and pressing the polyimide alloy resin powder produced by the method for producing a polyimide alloy resin powder according to any one of 6) to 12).

Advantages of the Invention

[0026] According to the present invention, it is possible to provide a method for manufacturing a molded article and a film that are excellent in moldability, have high transparency, and have sufficient mechanical strength, a resin powder used for the production thereof, and a method for producing the resin powder.

Modes for Carrying Out the Invention

[0027] <Polyimide alloy resin powder> The polyimide alloy resin powder of the present invention is composed of a polyimide resin and a resin having an ester bond, and the glass transition temperature of the polyimide alloy resin powder is 200°C or less, which is different from the glass transition temperatures of the polyimide resin and the resin having an ester bond, and the glass transition temperature of the polyimide alloy resin powder exists in the temperature range between the glass transition temperatures of the polyimide resin and the resin having an ester bond, and the 1% weight loss temperature of the polyimide alloy resin powder is 280°C or higher. It is more preferable that the polyimide alloy resin powder has only one glass transition temperature because the transparency tends to improve.

[0028] <Polyimide> Polyimide is obtained by dehydrating and cyclizing a polyamic acid obtained by the addition polymerization of a tetracarboxylic dianhydride (hereinafter sometimes referred to as "dianhydride") and a diamine. That is, polyimide is a polycondensate of a tetracarboxylic dianhydride and a diamine, and has a structure derived from the dianhydride (dianhydride component) and a structure derived from the diamine (diamine component).

[0029] In addition to the structure derived from the diamine and the structure derived from the tetracarboxylic dianhydride, the polyimide may contain a structure derived from a dicarboxylic acid or a structure derived from trimellitic acid. When it contains a structure derived from a dicarboxylic acid or a structure derived from trimellitic acid, it is narrowly called a polyamide-imide, but in the present invention, it is described as a polyimide including a polyamide-imide.

[0030] The polyimide used in the present invention is preferably soluble in an organic solvent, and preferably dissolves at a concentration of 3 g or more per 100 g of an amide-based solvent such as N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), or N,N-dimethylacetamide (DMAc). The polyimide is particularly preferably soluble not only in an amide-based solvent such as DMF but also in a non-amide-based solvent.

[0031] <Dianhydride> There is no particular limitation on the dianhydride used in the polyimide of the present invention, and examples thereof include a dianhydride having an ether bond, a dianhydride having a cardo structure, a bis(trimellitic anhydride) ester, an alicyclic tetracarboxylic dianhydride, an aromatic dianhydride, and other dianhydrides.

[0032] From the viewpoints of improving the solubility of the polyimide resin in a solvent, improving the compatibility of the polyimide resin with a resin having an ester bond, transparency, mechanical strength, etc., it is preferable to include a dianhydride selected from a dianhydride having an ether bond, a dianhydride having a cardo structure, and a bis(trimellitic anhydride) ester as the dianhydride.

[0033] From the perspective of making the polyimide resin soluble in an organic solvent, the total content of the acid dianhydrides selected from acid dianhydrides having an ether bond, acid dianhydrides having a cardo structure, and bis(trimellitic anhydride) ester is preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, and may be 30 mol% or more, 35 mol% or more, 40 mol% or more, 45 mol% or more, or 50 mol% or more, based on 100 mol% of the total amount of the acid dianhydride component. The total content of the acid dianhydrides selected from acid dianhydrides having an ether bond, acid dianhydrides having a cardo structure, and / or bis(trimellitic anhydride) ester may be 100 mol%, or may be 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, 75 mol% or less, or 70 mol% or less, based on 100 mol% of the total amount of the acid dianhydride component.

[0034] Examples of the acid dianhydride having an ether bond include 3,4'-oxydiphthalic anhydride (a-ODPA), 4,4'-oxydiphthalic anhydride (s-ODPA), 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), and the like. From the perspective of the solubility of the polyimide resin and the compatibility with the resin having an ester bond, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA) is particularly preferred. By using the acid dianhydride having an ether bond, the solubility of the polyimide resin in a solvent tends to improve, and the compatibility between the polyimide resin and the resin having an ester bond also tends to improve.

[0035] Examples of the acid dianhydride having a cardo structure include acid dianhydrides having a fluorene structure.

[0036] Examples of the dianhydride having a fluorene structure include 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (BPF-PPA), N,N'-(9H-fluorene-9-ylidenedi-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxamide] (FDA-ATA), 5,5'-(9H-fluorene-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate] (TBIS.MPN), 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate (TBIS.RXN), spiro[11H-difluoro[3,4-b:3',4'-i]xanthene-11,9'-[9H]fluorene]-1,3,7,9-tetrone (SFDA), and the like. From the viewpoints of the solubility of the polyimide resin and the compatibility with the resin having an ester bond, BPAF or BPF-PPA, SFDA is particularly preferable. By using the dianhydride having a fluorene structure, the solubility of the polyimide resin in a solvent tends to be improved, and the compatibility of the polyimide resin with the resin having an ester bond tends to be improved.

[0037] The bis(trimellitic anhydride) ester is represented by the following general formula (1).

[0038]

Chemical formula

[0039] X in the general formula (1) is an arbitrary divalent organic group, and at both ends of X, a carboxy group is bonded to a carbon atom of X. The carbon atom bonded to the carboxy group may form a ring structure. Specific examples of the divalent organic group X include the following (A) to (K).

[0040]

Chemical formula

[0041] R in formula (A) 1 is a fluorine atom or an alkyl group having 1 to 20 carbon atoms, and m is an integer of 1 to 4. The group represented by formula (A) is a group obtained by removing two hydroxyl groups from a hydroquinone derivative having a substituent on the benzene ring. Examples of the hydroquinone having a substituent on the benzene ring include tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, and the like.

[0042] R in formula (B) 2 is a fluorine atom or an alkyl group having 1 to 20 carbon atoms, and n is an integer of 0 to 4. The group represented by formula (B) is a group obtained by removing two hydroxyl groups from a biphenol which may have a substituent on the benzene ring. Examples of the biphenol derivative having a substituent on the benzene ring include 2,2'-dimethylbiphenyl-4,4'-diol, 3,3'-dimethylbiphenyl-4,4'-diol, 3,3',5,5'-tetramethylbiphenyl-4,4'-diol, 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diol, and the like.

[0043] The group represented by formula (C) is a group obtained by removing two hydroxyl groups from 4,4'-isopropylidenediphenol (bisphenol A). The group represented by formula (D) is a group obtained by removing two hydroxyl groups from resorcinol.

[0044] p in formula (E) is an integer of 1 to 10. The group represented by formula (E) is a group obtained by removing two hydroxyl groups from a linear diol having 1 to 10 carbon atoms. Examples of the linear diol having 1 to 10 carbon atoms include ethylene glycol, 1,4-butanediol, and the like.

[0045] The group represented by formula (F) is a group obtained by removing two hydroxyl groups from 1,4-cyclohexanedimethanol.

[0046] R in formula (G)3 is a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 20 carbon atoms, and q is an integer of 0 to 4. The group represented by formula (G) is a group obtained by removing two hydroxyl groups from bisphenol fluorene which may have a substituent on the benzene ring having a phenolic hydroxyl group. Examples of the bisphenol fluorene derivative having a substituent on the benzene ring having a phenolic hydroxyl group include biscresol fluorene. When having the structure of formula (G), it corresponds to both an acid dianhydride having a fluorene structure and a bis(trimellitic anhydride) ester, but in the present invention, it is assumed to correspond to a bis(trimellitic anhydride) ester.

[0047] The bis(trimellitic anhydride) ester is preferably an aromatic ester. Among the above (A) to (K), (A), (B), (C), (D), (G), (H), and (I) are preferred for X. Among them, (A) to (D) are preferred, and a group having a biphenyl skeleton of (B) is particularly preferred. When X is a group represented by general formula (B), from the viewpoint of the solubility of the polyimide resin, X is preferably 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diyl represented by the following formula (B1).

[0048]

Chemical formula

[0049] The acid dianhydride in which X in general formula (1) is a group represented by formula (B1) is bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diyl (abbreviation: TAHMBP) represented by the following formula (3).

[0050]

Chemical formula

[0051] Among the acid dianhydrides having an ether bond, the acid dianhydrides having a cardo structure, and the bis(trimellitic anhydride) esters, from the viewpoint of the UV resistance of the resulting polyimide resin, acid dianhydrides having an ether bond and acid dianhydrides having a fluorene structure are preferred. From the viewpoints of solubility in solvents and mechanical strength, BPADA, a-ODPA, s-ODPA, BPAF, BPF-PPA, SFDA, and the structure are particularly preferred. When there is no ester bond, since the Fries rearrangement by UV light does not occur, when the resulting polyimide resin is exposed to UV light, it tends to be less likely to be colored.

[0052] Among the acid dianhydrides having an ether bond, the acid dianhydrides having a cardo structure, and the bis(trimellitic anhydride) esters, from the viewpoint of the dissolution of the resulting polyimide resin in non-amide solvents, acid dianhydrides having an ether bond, acid dianhydrides having a fluorene structure, and bis(trimellitic anhydride) esters are preferred, and BPADA, BPAF, BPF-PPA, TBIS.MPN, P-phenylene bis(trimellitate anhydride) (TAHQ), 5,5′-(3,3′-dimethyl[1,1′-biphenyl]-4,4′-diyl) bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) (BP-TME), P-biphenylene bis(trimellitate anhydride) (OCBP-TME), tert-butylhydroquinone bis(trimellitate anhydride) (TA.BHQ), trimethylhydroquinone bis(trimellitate anhydride) (TA.TMHQ), and TAHMBP are more preferred, and BPAF, BPF-PPA, and TBIS.MPN having a fluorene structure are even more preferred.

[0053] The polyimide used in the present invention may contain, as an acid dianhydride component, an acid dianhydride component other than the acid dianhydrides selected from the acid dianhydrides having an ether bond, the acid dianhydrides having a cardo structure, and the bis(trimellitic anhydride) esters. Examples of such acid dianhydride components include alicyclic tetracarboxylic dianhydrides, aromatic acid dianhydrides, and / or other acid dianhydrides.

[0054] Examples of alicyclic tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, meso-butane-1,2,3,4-tetracarboxylic dianhydride, 1,1'-bicyclohexane-3,3',4,4'-tetracarboxylic acid-3,4:3',4'-dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride, 2,2'-binorbornane-5,5',6,6'-tetracarboxylic dianhydride, 3-(carboxymethyl)-1,2,4-cyclopentanetricarboxylic acid 1,4:2,3-dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, cyclohexane-1,4-diylbis(methylene)bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate), 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 5,5'-[cyclohexylidenebis(4,1-phenyleneoxy)]bis-1,3-isobenzofurandione, 5-isobenzofurancarboxylic acid, 1,3-dihydro-1,3-dioxo-, 5,5'-[1,4-cyclohexanediylbis(methylene)]ester, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid 2,3:5,6-dianhydride, decahydro-1,4,5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic dianhydride, tricyclo[6.4.0.0(2,7)]Dodecane-1,8:2,7-tetracarboxylic dianhydride, octahydro-1H,3H,8H,10H-biphenylene[4a,4b-c:8a,8b-c']difuran-1,3,8,10-tetrone, ethylene glycol bis(hydrogen trimellitic anhydride) ester, decahydro[2]benzopyrano[6,5,4,-def][2]benzopyran-1,3,6,8-tetrone, etc. can be mentioned. When the dianhydride component has an alicyclic structure, the compatibility between the polyimide resin and the resin having an ester bond tends to improve. The alicyclic tetracarboxylic dianhydride only needs to have at least one alicyclic structure, and may have both an alicyclic ring and an aromatic ring in one molecule. The alicyclic ring may be a polycyclic ring or may have a spiro structure.

[0055] Among the alicyclic tetracarboxylic dianhydrides, from the viewpoints of the transparency and mechanical strength of the polyimide, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA), 1,2,3,4-butanetetracarboxylic dianhydride (BT-100), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA-100), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BEDA), bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride (BODA), or 1,1'-bicyclohexane-3,3',4,4'-tetracarboxylic acid-3,4:3',4'-dianhydride (H-BPDA) are preferable. Among them, from the viewpoint of mechanical strength, a tetracarboxylic anhydride in which two acid anhydride groups are bonded to one alicyclic ring is preferable, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride is particularly preferable.

[0056] When using an alicyclic tetracarboxylic dianhydride, from the viewpoints of enhancing the compatibility with a resin having an ester bond and mechanical strength, the content of the alicyclic tetracarboxylic dianhydride relative to 100 mol% of the total amount of the acid dianhydride component is preferably 1 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, and may be 10 mol% or more, 12 mol% or more, or 15 mol% or more. The amount of the alicyclic tetracarboxylic dianhydride required to impart compatibility with the resin having an ester bond may vary depending on the resin having an ester bond, the type of the alicyclic tetracarboxylic dianhydride amount, and the like.

[0057] From the viewpoint of ensuring the solubility of the polyimide resin in an organic solvent, the content of the alicyclic tetracarboxylic dianhydride relative to 100 mol% of the total amount of the acid dianhydride component is preferably 80 mol% or less, more preferably 60 mol% or less, and may be 50 mol% or less, 30 mol% or less, or may not be contained. In order to make the polyimide resin compatible with the resin having an ester bond even in a low-boiling non-amide solvent (for example, a halogen-based solvent such as methylene chloride), the content of the alicyclic tetracarboxylic dianhydride is preferably 60 mol% or less, more preferably 40 mol% or less, and may be 20 mol% or less, or may not be contained.

[0058] Examples of the aromatic dianhydrides include pyromellitic dianhydride (PMDA), 1,2,3,4-benzenetetracarboxylic dianhydride (MPDA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA), 2,2′,3,3′,-biphenyltetracarboxylic dianhydride (i-BPDA), 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA), 5,5′-dimethylmethylene bis(phthalic anhydride), 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, terphenyltetracarboxylic dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, and the like. Among these aromatic dianhydrides, from the viewpoint of improving mechanical strength, it is preferable to contain at least one of 2,3,3′,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′,-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, and 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride.

[0059] From the viewpoint of ensuring the solubility of the polyimide resin in an organic solvent, the content of the aromatic dianhydride with respect to 100 mol% of the total amount of the dianhydride component is preferably 80 mol% or less, more preferably 60 mol% or less, and may be 50 mol% or less, 30 mol% or less, or may not be contained. In order for the polyimide resin to be compatible with a resin having an ester bond even in a low-boiling non-amide solvent (for example, a halogen-based solvent such as methylene chloride), the content of the aromatic dianhydride is preferably 60 mol% or less, more preferably 40 mol% or less, and may be 20 mol% or less, or may not be contained.

[0060] As other acid dianhydrides, chain aliphatic acid dianhydrides such as ethylene tetracarboxylic dianhydride and butane tetracarboxylic dianhydride may be used.

[0061] <Diamine> There is no particular limitation on the diamine component of the polyimide used in the present invention, and examples thereof include diamines having a benzidine skeleton, diamines having a cardo structure, and other diamines.

[0062] From the viewpoints of improving the solubility of the polyimide resin in a solvent, improving the compatibility between the polyimide resin and a resin having an ester bond, transparency, mechanical strength, etc., a diamine having a benzidine skeleton or a diamine having a cardo structure is preferable.

[0063] Examples of diamines having a benzidine skeleton include benzidine, 2,2'-dimethylbenzidine, 3,3'-dimethylbenzidine, 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, 2,2',6,6'-tetrakis(trifluoromethyl)benzidine, 2-(trifluoromethoxy)benzidine, 3-(trifluoromethoxy)benzidine, 2,3-bis(trifluoromethoxy)benzidine, 2,5-bis(trifluoromethoxy)benzidine, 2,6-bis(trifluoromethoxy)benzidine, 2,3,5-tris(trifluoromethoxy)benzidine, 2,3,6-tris(trifluoromethoxy)benzidine, 2,3,5,6-tetrakis(trifluoromethoxy)benzidine, 2,2'-bis(trifluoromethoxy)benzidine, 3,3'-bis(trifluoromethoxy)benzidine, 2,3'-bis(trifluoromethoxy)benzidine, 2,2',3-tris(trifluoromethoxy)benzidine, 2,3,3'-tris(trifluoromethoxyl)benzidine, 2,2',5-tris(trifluoromethoxy)benzidine, 2,2',6-tris(trifluoromethoxy)benzidine, 2,3',5-tris(trifluoromethoxy)benzidine, 2,3',6,- Tris(trifluoromethoxy)benzidine, 2,2’,3,3’-tetrakis(trifluoromethoxy)benzidine, 2,2’,5,5’-tetrakis(trifluoromethoxy)benzidine, 2,2’,6,6’-tetrakis(trifluoromethoxy)benzidine and the like can be mentioned. Among the above-mentioned benzidines, from the viewpoints of improving the solubility of the polyimide resin in a solvent, improving the compatibility between the polyimide resin and a resin having an ester bond, transparency, mechanical strength, etc., a benzidine structure containing fluorine is more preferable, and 2,2’-bis(trifluoromethyl)benzidine and 2,2’-bis(trifluoromethoxy)benzidine are more preferable. Further, among the fluorine-containing benzidines, from the viewpoint of degradability in the environment, benzidine having no trifluoromethyl structure is preferable, and 2,2’-bis(trifluoromethoxy)benzidine is particularly preferable.,

[0064] Examples of the diamine having a cardo structure include 9,9-bis(4-aminophenyl)fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 10,10-bis(4-aminophenyl)-9(10H)-anthracene, 9,9-bis(p-aminophenyl)-9,10-dihydroanthracene and the like.

[0065] The content of the diamine having a structure selected from the diamine having a benzidine skeleton or the diamine having a cardo structure with respect to 100 mol% of the total amount of the diamine component is preferably 10 mol% or more, more preferably 30 mol% or more, still more preferably 50 mol% or more, and may be 60 mol% or more, 70 mol% or more or 80 mol% or more, or even 100 mol%. By containing the diamine having a structure selected from the diamine having a benzidine skeleton or the diamine having a cardo structure, coloring of the film is suppressed, and mechanical strengths such as pencil hardness, elastic modulus, breaking strength, and elongation at break may be improved.

[0066] Examples of other diamines include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 1,1-bis(3-aminophenyl)-1-phenylethane, 1,1-bis(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-aminobenzoyl)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-dimethylbenzyl]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]diphenyl sulfone, 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenyl sulfone, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 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-aminomethoxy)ethyl]ether, bis[2-(2-aminoethoxy)ethyl]ether, bis[2-(3-aminopropoxy)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-aminopropyl)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, 1,9-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-aminocyclohexyl)methane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,2-diamino-4-(trifluoromethoxy)benzene (TFMOBzo), 1,3-diamino-4-(trifluoromethoxy)benzene (TFMOBzm), 1,4-diamino-2-(trifluoromethoxy)benzene, 1,4-diamino-2,3-bis(trifluoromethoxy)benzene, 1,4-diamino-2,5-bis(trifluoromethoxy)benzene, 1,4-diamino-2,6-bis(trifluoromethoxy)benzene, 1,4-diamino-2,3,5-tris(trifluoromethoxy)benzene, 1,4-diamino-2,3,5,Examples include 6-tetrakis(trifluoromethoxy)benzene, etc.

[0067] <Dicarboxylic acid or trimellitic acid> As described above, the polyimide may be a polyamideimide containing a structure derived from a dicarboxylic acid or a structure derived from trimellitic acid. Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-oxybisbenzoic acid, biphenyl-4,4'-dicarboxylic acid, 2-fluoroterephthalic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid; and heterocyclic dicarboxylic acids such as 2,5-thiophenedicarboxylic acid, 2,5-furandicarboxylic acid. As the dicarboxylic acid, terephthalic acid and / or isophthalic acid is preferable, and terephthalic acid is particularly preferable.

[0068] In the preparation of polyamideimide (polyimide containing a structure derived from dicarboxylic acid or trimellitic acid), it is preferable to use dicarboxylic acid dichloride or trimellitic anhydride chloride as a monomer. Further, a polyamideimide may be prepared using, as a monomer, a compound obtained by condensing a dicarboxylic acid (or a derivative such as dicarboxylic acid dichloride) and a diamine, or a compound obtained by condensing trimellitic acid (or trimellitic anhydride chloride) and a diamine.

[0069] <Preparation of polyimide> A polyamic acid as a polyimide precursor is obtained by the reaction of an acid dianhydride and a diamine, and a polyimide is obtained by dehydration cyclization (imidization) of the polyamic acid. As described above, by adjusting the composition of the polyimide, that is, the types and ratios of the acid dianhydride and the diamine, the polyimide has transparency and solubility in an organic solvent, and shows compatibility with a resin having an ester bond. Similarly, when preparing a polyamideimide, a polyamic acid as a polyamideimide precursor is obtained by the reaction of an acid dianhydride, a diamine, and a dicarboxylic acid or trimellitic acid, and a polyamideimide is obtained by dehydration cyclization (imidization) of the polyamic acid.

[0070] The method for preparing the polyamic acid is not particularly limited, and any known method can be applied. For example, an acid dianhydride and a diamine are dissolved in an organic solvent in a substantially equimolar amount (molar ratio of 95:100 to 105:100) and stirred to obtain a polyamic acid solution. The concentration of the polyamic acid solution is usually 5 to 35% by weight, preferably 10 to 30% by weight. When the concentration is in this range, the polyamic acid obtained by polymerization has an appropriate molecular weight, and the polyamic acid solution has an appropriate viscosity.

[0071] In the polymerization of the polyamic acid, in order to suppress the ring opening of the acid dianhydride, a method of adding the acid dianhydride to the diamine is preferred. When adding a plurality of types of diamines or a plurality of types of acid dianhydrides, they may be added at once or divided into a plurality of times for addition. By adjusting the addition order of the monomers, various physical properties of the polyimide can also be controlled.

[0072] The organic solvent used for the polymerization of polyamic acid is not particularly limited as long as it does not react with diamine and acid dianhydride and can dissolve polyamic acid. Examples of the organic solvent include urea solvents such as methyl urea and N,N-dimethylethyl urea, sulfoxide or sulfone solvents such as dimethyl sulfoxide, diphenyl sulfone, and tetramethyl sulfone, amide solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), N,N'-diethylacetamide, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, and hexamethylphosphoric triamide, alkyl halide solvents such as chloroform and methylene chloride, aromatic hydrocarbon solvents such as benzene and toluene, and ether solvents such as tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, dimethyl ether, diethyl ether, and p-cresol methyl ether. Usually, these solvents are used alone or in appropriate combinations of two or more as needed. From the viewpoints of the solubility and polymerization reactivity of polyamic acid, DMAc, DMF, NMP, etc. are preferably used.

[0073] Polyimide is obtained by the dehydration cyclization of polyamic acid. Examples of the method for preparing polyimide from a polyamic acid solution include adding a dehydrating agent, an imidization catalyst, etc. to the polyamic acid solution and allowing imidization to proceed in the solution. In order to promote the progress of imidization, the polyamic acid solution may be heated. By mixing the solution containing the polyimide formed by the imidization of polyamic acid with a poor solvent, the polyimide resin precipitates as a solid. By isolating the polyimide resin as a solid, impurities generated during the synthesis of polyamic acid, residual dehydrating agent, imidization catalyst, etc. can be washed and removed with the poor solvent, and coloring and an increase in yellowness of the polyimide can be prevented. Also, by isolating the polyimide resin as a solid, a solvent suitable for film formation such as a low-boiling solvent can be applied when preparing a solution for producing a film.

[0074] The molecular weight of the polyimide (weight-average molecular weight in terms of polyethylene oxide measured by gel permeation chromatography (GPC)) is preferably from 10,000 to 1,000,000, more preferably from 20,000 to 500,000, and even more preferably from 40,000 to 300,000. When the molecular weight is excessively small, the strength of the film may be insufficient. When the molecular weight is excessively large, the compatibility with the resin having an ester bond may be poor.

[0075] The polyimide needs to be soluble in a solvent, and is preferably soluble in any one of an amide-based solvent, a ketone-based solvent, and an alkyl halide-based solvent, and more preferably soluble in an amide-based solvent. The solubility in the solvent may be shown at any temperature, but is preferably shown at 60°C or lower, more preferably shown at 40°C or lower, and even more preferably shown at 23°C or lower. That the polyimide shows solubility in the solvent means that it dissolves at a concentration of 3% by weight or more.

[0076] From the viewpoints of the thermal stability and light stability of the resin composition and the film, the polyimide preferably has low reactivity. The acid value of the polyimide is preferably 0.4 mmol / g or less, more preferably 0.3 mmol / g or less, and even more preferably 0.2 mmol / g or less. The acid value of the polyimide may be 0.1 mmol / g or less, 0.05 mmol / g or less, or 0.03 mmol / g or less. From the viewpoint of reducing the acid value, the polyimide preferably has a high imidization rate. When the acid value is small, the stability of the polyimide is enhanced, and the compatibility with the resin having an ester bond tends to be improved.

[0077] <Resin having an ester bond> The resin having an ester bond may be any resin having an ester structure in the repeating structural unit, and specific examples include an acrylic resin, a polyester resin, a polycarbonate resin, and a polyarylate resin.

[0078] The glass transition temperature of the resin having an ester bond is not particularly limited, but from the viewpoint of the moldability of the resulting polyimide alloy, it is preferably 150 ° C or lower, and may be 140 ° C or lower or 130 ° C or lower.

[0079] <Acrylic resin> Examples of the acrylic resin include poly(meth)acrylic acid esters such as polymethyl methacrylate, methyl methacrylate-(meth)acrylic acid copolymer, methyl methacrylate-(meth)acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester-(meth)acrylic acid copolymer, (meth)acrylic acid methyl-styrene copolymer, and the like. The acrylic resin may be one into which a glutarimide structural unit or a lactone ring structural unit is introduced. The stereoregularity of the polymer is not particularly limited, and any of isotactic type, syndiotactic type, and atactic type may be used.

[0080] By introducing a glutarimide structure into an acrylic polymer such as polymethyl methacrylate, the glass transition temperature of the acrylic resin tends to increase. In addition, since the acrylic resin contains an imide structure, the compatibility with polyimide may be improved. For example, a specific polyimide resin may show compatibility with an acrylic resin having a glutarimide structure even when it does not show compatibility with polymethyl methacrylate. The acrylic resin having a glutarimide structure can be obtained, for example, by heating and melting a polymethyl methacrylate resin and treating it with an imidizing agent as described in JP-A-2010-261025.

[0081] When the acrylic polymer has a glutarimide structure, the glutarimide content may be 3% by weight or more, 10% by weight or more, 20% by weight or more, 30% by weight or more, or 50% by weight or more. The glutarimide content is that of the acrylic resin 1From the 1H-NMR spectrum, the imidization ratio Im = B / (A + B) is determined from the area A of the peak derived from the O-CH3 proton of methyl methacrylate and the area B of the peak derived from the N-CH3 proton of glutarimide, and can be calculated by converting the imidization ratio to weight. By introducing a glutarimide structure into the acrylic resin, an improvement in compatibility with polyimide and an improvement in the elastic modulus of the resulting molded body can be expected.

[0082] From the viewpoint of the heat resistance of the resin composition and the molded body, the glass transition temperature of the acrylic resin is preferably 100°C or higher, more preferably 110°C or higher, and may be 115°C or higher or 120°C or higher.

[0083] From the viewpoints of solubility in an organic solvent, compatibility with the above polyimide, and strength of the molded body, the weight average molecular weight (polystyrene conversion) of the resin having an ester bond is preferably 5,000 to 5,000,000, more preferably 10,000 to 2,000,000, and may be 30,000 to 1,000,000 or 50,000 to 500,000. When the molecular weight of the acrylic resin is too small, the durability of the resulting film may decrease. When the molecular weight of the acrylic resin is too high, the film-forming property may be inferior.

[0084] From the viewpoints of the thermal stability and light stability of the resin composition and the film, it is preferable that the resin having an ester bond has a low content of reactive functional groups such as ethylenically unsaturated groups and carboxy groups. The iodine value of the acrylic resin is preferably 10.16 g / 100 g (0.4 mmol / g) or less, more preferably 7.62 g / 100 g (0.3 mmol / g) or less, and even more preferably 5.08 g / 100 g (0.2 mmol / g) or less. The iodine value of the acrylic resin may be 2.54 g / 100 g (0.1 mmol / g) or less or 1.27 g / 100 g (0.05 mmol / g) or less. The acid value of the acrylic resin is preferably 0.4 mmol / g or less, more preferably 0.3 mmol / g or less, and even more preferably 0.2 mmol / g or less. The acid value of the acrylic resin may be 0.1 mmol / g or less, 0.05 mmol / g or less, or 0.03 mmol / g or less. When the acid value is small, the stability of the acrylic resin is enhanced, and the compatibility with polyimide tends to improve.

[0085] <Polycarbonate resin> Polycarbonate is a carbonate ester of bisphenol and has a repeating unit represented by the general formula (7). Z in the general formula (7) is an arbitrary divalent organic group, R3 is a halogen, an alkyl group having 1 to 20 carbon atoms, or a halogenated alkyl group having 1 to 20 carbon atoms, and j is an integer of 0 to 4.

Chemical formula

Chemical formula

[0086] From the viewpoints of solubility in an organic solvent and compatibility with the above polyimide, as the polycarbonate, it is preferable that the divalent organic group Z is an isopropylidene group and j = 0, that is, a carbonate ester of bisphenol A having a repeating unit of the formula (8).

[0087] Examples of commercially available polycarbonates containing the repeating unit of formula (8) include Panlite AD-5503, K-1300Y, L-1225L, L-1225LM, L-1225Y, L-1225Z100, L-1225Z100M, L-1225ZL100, L-1250Y, L-1250Z100, LD-1000RM, LN-1010RM, LN-2250Y, LN-2250Z, LN-2520A, LN-2520HA, LN-2525ZA, LN-3000RM, LN-3050RM, LS-2250, LV-2225L, LV-2225Y, LV-2225Z, LV-2250Y, LV-2250Z, MN-4800, MN-4800Z, MN-4805Z manufactured by Teijin; Iupilon K4100, ML200, ML300, ML400, etc. manufactured by Mitsubishi Engineering-Plastics.

[0088] The polycarbonate may contain a bisphenol component other than bisphenol A. Specific examples of bisphenols include 1,2-bis(4-hydroxyphenyl)ethane, 2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane, 1,2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)propane, 2,2-bis(3-n-propyl-4-hydroxyphenyl)propane, 2,2-bis(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 6,6'-dihydroxy-3,3,3',3'-tetramethylspiro(bis)indane, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxyanthracene, 2,7-dihydroxyphenoxathiin, 2,7-dihydroxy-9,10-dimethylphenazine, 3,6-dihydroxybenzofuran, 3,6-dihydroxyanthracene, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,2'-dimethylbiphenyl-4,4'-diol, 3,3'-dimethylbiphenyl-4,4'-diol, isopropylidenediphenol, 3,3',5,5'-tetramethylbiphenyl-4,4'-diol, 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diol, resorcinol, and the like.

[0089] The divalent organic group Z in formula (7) may contain a cyclic structure. Examples of the cyclic structure include aromatics such as fluorene skeletons and phthalimide skeletons; alicyclic skeletons such as cyclohexylmethylene, 2-[2.2.1]-bicycloheptylidene, cyclohexylidene, cyclopentylidene, cyclododecylidene, and adamantylidene. Specific examples of bisphenols in which Z contains a cyclic structure include 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 3,3-bis(4-hydroxyphenyl)phthalimidine, 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine, 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, and the like.

[0090] From the viewpoints of the strength of the film and the compatibility with the polyimide, the weight average molecular weight (polystyrene conversion) of the polycarbonate is preferably from 5,000 to 250,000, more preferably from 10,000 to 200,000, and still more preferably from 15,000 to 150,000.

[0091] <Polyarylate resin> The polyarylate is an ester of bisphenol and phthalic acid (terephthalic acid and / or isophthalic acid), and has a repeating unit represented by general formula (9).

Chemical formula

[0092] Z in general formula (9) is an arbitrary divalent organic group, R3 is a halogen, an alkyl group having 1 to 20 carbon atoms, or a halogenated alkyl group having 1 to 20 carbon atoms, and j is an integer of 0 to 4.

[0093] The ratio of the isophthalic acid-derived structure to the terephthalic acid-derived structure in the polyarylate is not particularly limited and is from 0:100 to 100:0. From the viewpoints of solubility in a solvent and compatibility with the above polyimide, the ratio of isophthalic acid to terephthalic acid is preferably from 2:98 to 98:2, and may be from 5:95 to 95:5, or from 10:90 to 90:10. From the viewpoints of solubility in an organic solvent and compatibility with the above polyimide, as the polyarylate, those in which the divalent organic group Z is an isopropylidene group and j = 0, that is, esters of bisphenol A having the repeating unit of formula (10) and phthalic acid are preferred. [Chemical formula]

[0094] Commercially available products of polyarylate containing the repeating unit of formula (10) include U-100, T-200, etc. manufactured by Unitika. As commercially available products of polyarylate, those such as U-8000, U-8400H, FUN-8000, C300VN, P-1001, P-3001, P-5001, P-1001A, P-3001S, P-5001S, etc. manufactured by Unitika may also be used.

[0095] The polyarylate may contain a bisphenol component other than bisphenol A. Specific examples of bisphenols other than bisphenol A include those shown above as the bisphenol components of polycarbonate.

[0096] From the viewpoints of the strength of the film and compatibility with the polyimide, the weight average molecular weight (polystyrene conversion) of the polyarylate is preferably from 5,000 to 150,000, more preferably from 10,000 to 130,000, and even more preferably from 15,000 to 100,000.

[0097] <Preparation of polyimide alloy resin powder> The method for producing a polyimide alloy resin powder comprises a step of dissolving a polyimide resin that dissolves 3 g or more per 100 g of a solvent in an amide-based solvent selected from DMF, NMP, and DMAc, and a resin having an ester bond in a solvent. A step of mixing the solution in which the polyimide resin and the resin having an ester bond are dissolved with a poor solvent to precipitate a polyimide alloy resin. It is characterized by having a step of drying the precipitated polyimide alloy resin.

[0098] Since the above polyimide resin and the resin having an ester bond can show compatibility in any ratio, the ratio of the polyimide resin to the resin having an ester bond in the polyimide alloy resin powder is not particularly limited. The mixing ratio (weight ratio) of the polyimide resin to the resin having an ester bond may be 98:2 to 2:98, 95:5 to 10:90, or 90:10 to 15:85. The higher the ratio of the polyimide resin, the higher the elastic modulus of the molded body and the better the mechanical strength tend to be. The higher the ratio of the resin having an ester bond, the less coloring of the film and the higher the transparency tend to be, and the glass transition temperature decreases and the moldability improves.

[0099] In order to sufficiently exhibit the effect of improving transparency by mixing polyimide and a resin having an ester bond, the ratio of the resin having an ester bond to the total of polyimide and the resin having an ester bond is preferably 10% by weight or more, and may be 15% by weight or more, 20% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more, or 50% by weight or more.

[0100] Polyimide is a polymer having a special molecular structure. Generally, it has low solubility in organic solvents and does not show compatibility with other polymers. In the present invention, by using a specific polyimide, it shows high solubility in an organic solvent and shows compatibility with a resin having an ester bond.

[0101] As a good solvent for dissolving a polyimide resin and a resin having an ester bond, there is no particular limitation as long as it shows solubility in both the polyimide resin and the resin having an ester bond. Examples of the solvent include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; ether solvents such as tetrahydrofuran and 1,4-dioxane; ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, diethyl ketone, cyclopentanone, cyclohexanone, and methyl cyclohexanone; and halogenated alkyl solvents such as chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, dichlorobenzene, and methylene chloride.

[0102] From the viewpoints of the solubility of the polyimide resin and the compatibility between the polyimide resin and the resin having an ester bond in the solution, an amide solvent or a ketone solvent is preferable as the good solvent, and an amide solvent is particularly preferable.

[0103] The fact that the polyimide resin and the resin having an ester bond are compatible in a good solvent means that the solution in which the polyimide resin and the resin having an ester bond are dissolved has a haze of 10 or less, preferably 5.0 or less, more preferably 3.0 or less, and still more preferably 1.0 or less in a solution with a solid content concentration of 5 wt%.

[0104] As the poor solvent for precipitating the dissolved polyimide resin and the resin having an ester bond, there is no particular limitation as long as it has low solubility in both the polyimide resin and the resin having an ester bond. Examples of the solvent include alcohol solvents such as methanol, ethanol, 1-propanol, 2-propanol, and water. Further, when a ketone solvent is selected as the good solvent, these may be used as long as an ether solvent or an alkyl halide solvent is the poor solvent. When an amide solvent is selected as the good solvent, a ketone solvent, an ether solvent, or an alkyl halide solvent may be used as long as it is the poor solvent.

[0105] From the viewpoints of the solubility and compatibility between the polyimide resin and the resin having an ester bond, an alcohol solvent or water is preferable as the poor solvent, and an alcohol solvent is particularly preferable.

[0106] As the combination of the good solvent and the poor solvent, among the combinations described above, it is particularly preferable to select an amide solvent as the good solvent and an alcohol solvent as the poor solvent. By selecting such a good solvent and poor solvent, the obtained polyimide alloy resin powder tends to have a single glass transition temperature, and the moldability of the obtained resin powder is improved. The temperature at which the poor solvent is added is not particularly limited, but it is preferably a temperature not exceeding the boiling point of the good solvent from the viewpoint of process safety. If the polyimide alloy resin powder can be obtained by adding the poor solvent near room temperature, it is preferable to add it near room temperature from the viewpoint of energy efficiency. When a polyimide alloy powder having a plurality of glass transition temperatures is obtained by adding the poor solvent near room temperature, by raising the temperature at which the poor solvent is added, a polyimide alloy resin powder having a single glass transition temperature tends to be easily obtained. The specific temperature varies depending on the type of the good solvent, but is, for example, in the range of -20°C to 180°C, may be 0°C to 150°C, may be 15°C to 120°C, or may be 20°C to 90°C.

[0107] There is no particular limitation on the addition rate of the poor solvent either. However, when an addition method such as adding it in portions over several times instead of adding the entire amount at once, or adding it continuously dropwise over time is used, a polyimide alloy resin powder having a single glass transition temperature is likely to be obtained.

[0108] From the perspective of the process, the amount of the good solvent used needs to be at least an amount sufficient for the polyimide resin and the resin having an ester bond to completely dissolve. There is no limitation on the upper limit, but when there is a large amount of the good solvent, a large amount of the poor solvent required to obtain the resin powder is also needed, which is inefficient. Therefore, the amount of the good solvent is preferably 1.0 to 10.0 times, more preferably 1.0 to 3.0 times, and even more preferably 1.0 to 1.5 times the amount sufficient for the polyimide resin and the resin having an ester bond to completely dissolve. The minimum amount of the good solvent required for complete dissolution varies depending on the temperature, and thus it is set according to the temperature at which dissolution is carried out and the temperature at the time of adding the poor solvent.

[0109] The amount of the poor solvent used needs to be at least an amount at which the polyimide alloy resin powder begins to precipitate. Considering the yield of the resin powder, it is preferable to add the poor solvent until the precipitation of the polyimide alloy resin powder is complete and no further precipitation occurs. Adding more of the poor solvent is not preferable from the perspective of environmental load and cost because it does not affect the yield of the polyimide alloy resin powder. Specifically, the amount of the poor solvent used is 0.1 to 1000 times, preferably 0.3 to 100 times, more preferably 0.5 to 10 times, and even more preferably 1 to 5 times the amount of the good solvent added.

[0110] The resin powder may be blended with organic or inorganic low molecular compounds, high molecular compounds (such as epoxy resins), etc. The resin powder may contain a flame retardant, an ultraviolet absorber, a crosslinking agent, a dye, a pigment, a surfactant, a leveling agent, a plasticizer, fine particles, a sensitizer, etc. The fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, inorganic fine particles such as colloidal silica, carbon, and layered silicate, etc., and may have a porous or hollow structure. The fiber reinforcing material includes carbon fiber, glass fiber, aramid fiber, etc.

[0111] <Polyimide alloy resin powder> The polyimide alloy resin powder composed of a polyimide resin and a resin having an ester bond preferably has a glass transition temperature measured by differential scanning calorimetry (DSC) and / or dynamic viscoelasticity measurement (DMA) of 200 °C or lower, and may be 190 °C or lower, 180 °C or lower, 170 °C or lower, or 160 °C or lower. The lower the glass transition temperature, the more excellent the moldability tends to be. The glass transition temperature of the polyimide alloy resin powder is different from the glass transition temperatures of the polyimide resin and the resin having an ester bond. Further, the glass transition temperature of the polyimide alloy resin powder exists in the temperature range between the glass transition temperatures of the polyimide resin and the resin having an ester bond.

[0112] The polyimide alloy resin powder preferably has a single glass transition temperature. When the resin composition has a single glass transition temperature, it can be considered that the polyimide and the resin having an ester bond are completely compatible. When the resin powder has a single glass transition temperature, the moldability tends to be good.

[0113] The polyimide alloy resin powder composed of a polyimide resin and a resin having an ester bond preferably has a 1% weight loss temperature of 280 °C or higher in thermogravimetric analysis (TGA), more preferably 300 °C or higher, and may be 320 °C or higher, 340 °C or higher. When the 1% weight loss temperature is high, the thermal decomposition of the polyimide alloy resin during molding is suppressed, the moldability is improved, and the transparency and mechanical strength of the obtained molded body tend to be improved.

[0114] As an index for measuring the moldability of a polyimide alloy resin powder composed of a polyimide resin and a resin having an ester bond, the melt viscosity can be mentioned. Generally, the lower the melt viscosity at a specific temperature, the better the moldability. In the polyimide alloy resin powder, it is preferable to perform molding at a temperature equal to or lower than the 1% thermal weight loss temperature. Therefore, it is preferable that the melt viscosity at a temperature equal to or lower than the 1% weight loss temperature is low. Specifically, at a temperature lower than the 1% weight loss temperature of the polyimide alloy resin powder, the melt viscosity is 30 kPa·s, preferably less than 10 kPa·s, more preferably 7.0 kPa·s or less, and may be 5 kPa·s or less or 2.0 kPa·s.

[0115] <Formed body and film> The above polyimide alloy resin powder can be used to form various formed bodies by heating and pressurizing. Examples of the molding method include melting methods such as injection molding, transfer molding, press molding, blow molding, inflation molding, calendar molding, and melt extrusion molding. The polyimide alloy resin powder tends to have a lower melt viscosity than the polyimide alone and is excellent in moldability such as injection molding, transfer molding, press molding, and melt extrusion molding.

[0116] In one embodiment, the formed body is a film and can be manufactured by heating and pressurizing the polyimide alloy resin powder.

[0117] A film composed only of a resin having an ester bond may have low toughness and elastic modulus, but the strength of the film may be improved by adopting a compatible system of a polyimide and a resin having an ester bond. For the purpose of improving the mechanical strength of the film, stretching may be performed in one direction or a plurality of directions. When the film is stretched, the polymer chains are oriented in the stretching direction, so that the strength in the in-plane direction of the film is improved, and the occurrence of cracks and cracks in the film tends to be suppressed.

[0118] In particular, in a compatible system of polyimide and a resin having an ester bond, the tensile modulus in the stretching direction tends to increase, and accordingly, the flexural resistance tends to improve.

[0119] For example, a film used as a cover film or a substrate material of a foldable display device (foldable display) is repeatedly bent along the folding axis at the same location, so it is required to have high mechanical strength in the direction perpendicular to the folding axis. Therefore, by arranging the stretching direction of the film to be perpendicular to the folding axis, even when folding is repeated, cracks or cracks in the film at the folding location are less likely to occur, and a device with high folding resistance can be provided.

[0120] The stretching conditions of the film are not particularly limited. For example, the stretching temperature is about the glass transition temperature of the film ±40°C, and may be about 80 - 260°C, 100 - 240°C or 120 - 200°C. The stretching ratio is about 1 - 300%, and may be 5 - 150%, 10 - 120%, 20 - 100%. The larger the stretching ratio, the greater the tensile modulus in the stretching direction tends to be. On the other hand, when the stretching ratio is excessively large, the mechanical strength in the direction perpendicular to the stretching direction tends to decrease, and the handleability of the film may decrease.

[0121] From the perspective of increasing the strength in any direction in the plane, the film may be biaxially stretched. The biaxial stretching may be simultaneous biaxial stretching or sequential biaxial stretching. In biaxial stretching, the stretching ratio in one direction and the stretching ratio in the orthogonal direction may be the same or different. When a difference is provided in the stretching ratio, the mechanical strength in the direction with a larger stretching ratio tends to be relatively large. When using a biaxially stretched film with anisotropy in the stretching ratio for a foldable device, it is preferable to arrange the direction with a larger stretching ratio to be perpendicular to the folding axis.

[0122] The thickness of the film is not particularly limited and may be appropriately set according to the application. The thickness of the film is, for example, 5 to 1000 μm. From the viewpoint of achieving both self-supporting property and flexibility and obtaining a highly transparent film, the thickness of the film is preferably 20 μm to 500 μm, and may also be 30 μm to 300 μm, 40 μm to 200 μm, or 50 μm to 100 μm. For use as a cover film for a display, the thickness of the film is preferably 10 μm or more. When the film is stretched, the thickness after stretching is preferably within the above range.

[0123] The haze of the film is preferably 10% or less, more preferably 5% or less, still more preferably 4% or less, and may also be 3.5% or less, 3% or less, 2% or less, or 1% or less. The lower the haze of the film, the more preferable. As described above, since the polyimide and the resin having an ester bond exhibit compatibility, a film with low haze and high transparency can be obtained. The resin composition in which the polyimide and the resin having an ester bond are mixed preferably has a haze of 10% or less when a film with a thickness of 50 μm is produced.

[0124] The yellowness index (YI) of the film is preferably 10.0 or less, and may also be 8.0 or less, 6.0 or less, 4.0 or less, 2.0 or less, or 1.0 or less. As described above, by mixing the polyimide and the resin having an ester bond, a film with less coloring and a smaller YI can be obtained compared to the case where the polyimide is used alone.

[0125] From the viewpoint of strength, the tensile elastic modulus of the film is preferably 2.5 GPa or more, more preferably 3.0 GPa or more, still more preferably 3.5 GPa or more, and may also be 4.0 GPa or more. The pencil hardness of the film is preferably 4B or more, more preferably 2B or more, still more preferably F or more, and may also be H or more, 2H or more, 3H or more. In the compatible system of the polyimide and the resin having an ester bond, even if the ratio of the resin having an ester bond is increased, the pencil hardness tends to be less likely to decrease. Therefore, it is possible to provide a film with less coloring and excellent transparency without significantly reducing the excellent mechanical strength peculiar to polyimide.

[0126] A film formed of a resin composition containing a polyimide and a resin having an ester bond has little coloring and high transparency, and thus is suitably used as a display material. In particular, a film having high mechanical strength can be applied to a surface member such as a cover window of a display. In practical use, an antistatic layer, an easy adhesion layer, a hard coat layer, an antireflection layer, etc. may be provided on the surface of the film of the present invention.

[0127] The use of the polyimide alloy resin powder is not limited to display films, and it may be used in various fields such as various electronic devices, automobiles, machinery, aerospace, electric wires and cables, 3D printing, and construction.

Examples

[0128] Hereinafter, embodiments of the present invention will be described more specifically with reference to examples. Note that the present invention is not limited to the following examples.

[0129] <Production Example of Polyimide Resin (CPI)> Dimethylformamide (DMF) was put into a separable flask and stirred under a nitrogen atmosphere. Thereto, diamine and acid dianhydride were put in the CPI composition (mol%) shown in Table 1, and stirred and reacted for 5 to 48 hours under a nitrogen atmosphere to obtain a polyamic acid solution having a solid content concentration of 18% by weight.

[0130] To 100 g of the polyamic acid solution, 5.5 g of pyridine as an imidization catalyst was added and completely dispersed, then 8 g of acetic anhydride was added, and the mixture was stirred at 90 ° C for 3 hours. After cooling to room temperature, while stirring the solution, 100 g of 2-propyl alcohol (hereinafter referred to as IPA) was added at a rate of 2 to 3 drops / second to precipitate polyimide. Further, 150 g of IPA was added, and after stirring for about 30 minutes, suction filtration was performed using a Kiriyama funnel. The obtained solid was washed with IPA and then dried in a vacuum oven set at 120 ° C for 12 hours to obtain a polyimide resin. The glass transition temperature of the obtained polyimide resin is as follows. CPI_1: TFMB / 6FDA / CBDA = 100 / 70 / 30, Tg = 322 °C CPI_2: TFMB / BPADA / TPC = 100 / 70 / 30, Tg = 238 °C

[0131] <Example of preparing polyimide alloy resin powder> <Examples 1 - 5> In dimethylformamide (DMF), the polyimide (CPI) obtained in the above polyimide resin production example and a resin having an ester bond (polymethyl methacrylate resin ("Parapet HM1000" manufactured by Kuraray, glass transition temperature: 120 °C, acid value: 0.0 mmol / g, hereinafter "HM"), a glutarimide-containing resin having a glutarimide content of 33% by weight and a glass transition temperature of 131 °C prepared according to "Production Example 3 of Resin Having an Ester Bond" in JP-A-2018-70710 (hereinafter "HGI"), or "UE3200G" manufactured by Unitika, glass transition temperature: 65 °C, a copolymer of terephthalic acid, isophthalic acid, neopentyl glycol, and ethylene glycol) were dissolved at 40 °C in the weight ratio described in Table 1 to prepare a DMF solution with a resin content of 10% by weight. While stirring 100 parts by mass of the obtained DMF solution, at 40 °C, 100 parts by mass of 2-propanol was added each time every 5 minutes until a total of 500 parts by weight was reached to precipitate polyimide alloy resin powder. After adding the total amount of 2-propanol and continuing stirring for 30 minutes, filtration was performed, and after washing with 100 parts by mass of 2-propanol, the polyimide alloy resin powder as the filtrate was dried in a vacuum oven set at 120 °C for 12 hours to obtain polyimide alloy resin powder.

[0132] <Melt extrusion> <Examples 1 - 5> The obtained polyimide alloy resin powder was subjected to melt extrusion molding at the temperature described in Table 1 using a capillary rheometer (Capilog type 1D) manufactured by Toyo Seiki Seisakusho Co., Ltd. In any condition, a melt molded body was obtained. Also, the melt viscosity at the extrusion temperature was as described in Table 1.

[0133] <Comparative Examples 1, 2> In Comparative Examples 1 and 2, melt extrusion was carried out in the same manner as in the Examples using a powder of polyimide resin alone. However, since the polyimide did not melt at the extrusion temperature and remained in a powder state, a melt-molded article could not be obtained. Also, since it did not melt, the melt viscosity could not be measured.

[0134] <Comparative Examples 3 to 5> In Comparative Examples 3 to 5, a powder of polyimide resin and a powder of a resin having an ester bond were mixed in a powder state, and melt extrusion was carried out in the same manner as in the Examples using the mixed powder. However, since the polyimide did not melt at the extrusion temperature and remained in a powder state, a melt-molded article could not be obtained. Also, since the polyimide did not melt, the melt viscosity could not be measured.

[0135] <Tg (°C)> DSC Using a differential scanning calorimeter "DSC7000X" manufactured by Hitachi, Ltd., the glass transition temperature (Tg) was measured by heating from room temperature at a rate of 10 °C / min. The intersection of the original baseline of the DSC curve and the tangent at the inflection point was defined as the glass transition temperature (Tg).

[0136] <1% Thermal Decomposition Temperature of the Alloy> Using a thermogravimetric analysis "STA7200" manufactured by Hitachi, Ltd., the 1% thermal decomposition temperature was measured by heating from room temperature at a rate of 10 °C / min. When the absolute dry weight before the start of the test was taken as 100%, the temperature at which the sample weight first fell below 99% was defined as the 1% thermal decomposition temperature.

[0137] [Evaluation Results] Table 1 shows the resin composition (composition of polyimide, type of resin having an ester bond, and mixing ratio), as well as the evaluation results of the resin powder.

[0138] In Table 1, the compounds are described by the following abbreviations. <Dianhydride> CBDA: 1,2,3,4-Cyclobutanetetracarboxylic Dianhydride BPADA: 4,4'-(4,4'-Isopropylidenediphenoxy)diphthalic Anhydride <Diamine> TFMB: 2,2'-Bis(trifluoromethyl)benzidine <Dicarboxylic dichloride> TPC: Terephthalic acid dichloride

[0139] As shown in Table 1, when producing polyimide alloy resin powder from a polyimide resin and a resin having an ester bond and melt-molding the obtained polyimide alloy resin powder, a good molded body was obtained. The extrusion temperatures in Examples 1 to 5 were in a region lower than the 1% thermal decomposition temperature of the polyimide alloy resin powder, and it was possible to perform molding without causing thermal decomposition of the polyimide alloy resin.

[0140] On the other hand, in Comparative Examples 1 and 2 using only the polyimide resin and Comparative Examples 3 to 5 using a resin mixture obtained by physically mixing the polyimide resin and a resin having an ester bond, the polyimide did not melt during melt molding, and a good molded body could not be obtained.

[0141] From these results, it can be seen that in Examples 1 to 5, the polyimide alloy resin powder composed of the polyimide and the resin having an ester bond is excellent in moldability.

[0142]

Table 1

Claims

1. A polyimide alloy resin powder composed of a polyimide resin and a resin having an ester bond, wherein the glass transition temperature of the polyimide alloy resin powder is 200°C or less, which is different from the glass transition temperatures of the polyimide resin and the resin having an ester bond, and the glass transition temperature of the polyimide alloy resin powder exists in the temperature range between the glass transition temperatures of the polyimide resin and the resin having an ester bond, and the 1% weight loss temperature of the polyimide alloy resin powder is 280°C or higher.

2. wherein the melt viscosity of the polyimide alloy resin powder is less than 30 kPa·s at a temperature lower than the 1% weight loss temperature of the polyimide alloy resin powder, and the glass transition temperature of the resin having an ester bond is 150°C or lower. The polyimide alloy resin powder according to claim 1.

3. The polyimide alloy resin powder according to claim 1, wherein the resin having an ester bond is composed of one or more selected from acrylic resins, polyester resins, polycarbonate resins, and polyarylate resins.

4. The polyimide resin has a structure derived from a tetracarboxylic dianhydride component and a structure derived from a diamine component, and as the tetracarboxylic dianhydride component, it contains one or more selected from tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(anhydride trimellitic acid) esters, and as the diamine component, it contains one or more of diamines having a benzidine skeleton and diamines having a cardo structure, and the polyimide resin is a soluble polyimide resin that dissolves 3 g or more per 100 g of a solvent selected from amide solvents such as N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and N,N-dimethylacetamide (DMAc). The polyimide alloy resin powder according to claim 1.

5. The polyimide alloy resin powder according to claim 1, characterized in that the polyimide alloy resin powder has only one glass transition temperature.

6. A step of dissolving a polyimide resin that dissolves 3 g or more per 100 g of a solvent in an amide-based solvent selected from DMF, NMP, and DMAc, and a resin having an ester bond in a solvent, A step of mixing a solution in which the polyimide resin and the resin having an ester bond are dissolved with a poor solvent to precipitate a polyimide alloy resin, A method for producing a polyimide alloy resin powder, comprising a step of drying the precipitated polyimide alloy resin.

7. The method for producing a polyimide alloy resin powder according to claim 6, characterized in that the solution in which the polyimide resin and the resin having an ester bond are dissolved has a haze of 10 or less in a solution having a solid content concentration of 5 wt%.

8. The glass transition temperature of the polyimide alloy resin powder is 200 °C or less, which is different from the glass transition temperatures of the polyimide resin and the resin having an ester bond, The glass transition temperature of the polyimide alloy resin powder exists in a temperature range between the glass transition temperatures of the polyimide resin and the resin having an ester bond, The method for producing a polyimide alloy resin powder according to claim 6, characterized in that the 1% weight loss temperature of the polyimide alloy resin powder is 280 °C or higher.

9. The melt viscosity of the polyimide alloy resin powder is less than 30 kPa·s at a temperature lower than the 1% weight loss temperature of the polyimide alloy resin powder, The method for producing a polyimide alloy resin powder according to claim 6, characterized in that the glass transition temperature of the resin having an ester bond is 150 °C or lower.

10. The method for producing a polyimide alloy resin powder according to claim 6, wherein the resin having the ester bond is composed of one or more selected from an acrylic resin, a polyester resin, a polycarbonate resin, and a polyarylate resin.

11. The polyimide resin has a structure derived from a tetracarboxylic dianhydride component and a structure derived from a diamine component. As the tetracarboxylic dianhydride component, it contains one or more selected from a tetracarboxylic dianhydride having an ether bond, a tetracarboxylic dianhydride having a cardo structure, and a bis(anhydride trimellitic acid) ester. As the diamine component, it contains one or more of a diamine having a benzidine skeleton and a diamine having a cardo structure. The method for producing a polyimide alloy resin powder according to claim 6, characterized by the above.

12. The method for producing a polyimide alloy resin powder according to claim 6, characterized in that the polyimide alloy resin powder has only one glass transition temperature.

13. A method for producing a molded body, characterized by heating and pressing the polyimide alloy resin powder according to any one of claims 1 to 5.

14. A method for producing a molded body, characterized by heating and pressing the polyimide alloy resin powder produced by the method for producing a polyimide alloy resin powder according to any one of claims 6 to 12.

15. A method for producing a film, characterized by heating and pressing the polyimide alloy resin powder according to any one of claims 1 to 5.

16. A method for producing a film, characterized by heating and pressing the polyimide alloy resin powder produced by the method for producing a polyimide alloy resin powder according to any one of claims 6 to 12.

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