Resin compositions, molded articles, and films

Abstract

The present invention provides molded articles such as films that are environmentally friendly, highly transparent, and possess sufficient mechanical strength, as well as resin compositions used in their production. [Solution] The solution comprises polyimide and polycarbonate, wherein the polyimide has CF3-O-,-(CF2-O) as a diamine component. n -, -O-(CF2-CF2-O) n The above problem can be solved by a resin composition characterized by containing a diamine having a structure selected from (where n is an integer from 1 to 20).

Description

[Technical Field]

[0001] The present invention relates to resin compositions and molded articles such as films. [Background technology]

[0002] Display devices such as liquid crystal displays, organic EL displays, and electronic paper, as well as electronic devices such as solar cells and touch panels, are required to be thinner, lighter, and more flexible. By replacing the glass materials used in these devices with film materials, flexibility, thinning, and weight reduction can be achieved. Transparent polyimide film has been developed as a glass substitute material and is used in display substrates and cover films, etc.

[0003] Conventional polyimide films are obtained by coating a polyamic acid solution, a polyimide precursor, onto a support in a film-like manner and then subjecting it to high-temperature treatment to remove the solvent and perform thermal imidization simultaneously. However, the heating temperature required for thermal imidization is high (e.g., 300°C or higher), and discoloration (increase in yellowness) is likely to occur due to heating, making it difficult to apply to applications requiring high transparency, such as display cover films.

[0004] As a method for producing highly transparent polyimide films, a method has been proposed using a polyimide resin that is soluble in organic solvents and does not require imidization at high temperatures after film formation. Such solvent-soluble polyimides often use fluorine-containing compounds to balance transparency and mechanical properties. For example, Patent Document 1 describes a polyimide containing an alicyclic tetracarboxylic dianhydride as the tetracarboxylic dianhydride component and a diamine having a perfluoroalkyl group as the diamine component, which is soluble in low-boiling point solvents such as methylene chloride.

[0005] In recent years, the environmental persistence of perfluorinated compounds (PFAS) has become a concern. Generally, the carbon-fluorine bonds contained in PFAS have high bonding energy, making them difficult to decompose in the environment. As a result, they accumulate in water and other substances, and their toxicity to humans has also been pointed out. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2023 / 026982 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] While introducing a rigid structure to polyimide improves its mechanical strength, it also reduces its solubility in organic solvents and its transparency. Therefore, it is not easy to achieve both high mechanical strength and transparency in conventional transparent polyimide resins. One method to improve solvent solubility is to use fluorine-containing compounds, but the use of fluorine compounds, which have high environmental persistence, raises concerns from an environmental safety perspective. In view of these issues, the present invention aims to provide molded articles such as films that are environmentally safe, highly transparent, and possess sufficient mechanical strength, as well as resin compositions used in their production. [Means for solving the problem]

[0008] As a result of diligent research, the inventors have found that the above problem can be solved by the following configuration.

[0009] 1) Containing polyimide and polycarbonate, The polyimide is a polyimide resin composition having a structure derived from a tetracarboxylic dianhydride component and a diamine component. The aforementioned diamine is CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) nA resin composition characterized by containing a diamine having one or more structures selected from the following (where n is an integer from 1 to 20).

[0010] 2) The resin composition according to 1), characterized in that the tetracarboxylic dianhydride component includes one or more acid dianhydrides selected from tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a fluorene structure, tetracarboxylic dianhydrides having a xanthene structure, and bis(trimellitic anhydride) esters.

[0011] 3) One or more acidic dianhydrides selected from the ether-bonded tetracarboxylic dianhydrides, fluorene-containing tetracarboxylic dianhydrides, xanthene-containing tetracarboxylic dianhydrides, and bis(trimellitic anhydride) esters, such as 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 5,5'-(9H-fluorene-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5- The resin composition according to 2), comprising at least one of isobenzofuran carboxylate, spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride, 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate, p-phenylenebis(trimellitate anhydride), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'diyl, and bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'diyl.

[0012] 4) The aforementioned CF3-O-, -(CF2-O) n-, -O-(CF2-CF2-O) n A diamine having a structure selected from n (where n is an integer from 1 to 20) is selected from 2,2'-bis(trifluoromethoxy)benzidine, 3,3'-bis(trifluoromethoxy)benzidine, 2,3'-bis(trifluoromethoxy)benzidine. The resin composition according to any one of 1) to 3) above is characterized by this.

[0013] 5). The content of the tetracarboxylic dianhydride component having a CF3- group directly bonded to the aromatic ring of the polyimide or -C(CF3)2- directly bonded to the aromatic ring is less than 0.5 mol% in all the tetracarboxylic dianhydride components, and the content of the diamine component having a CF3- group directly bonded to the aromatic ring of the polyimide resin composition or -C(CF3)2- directly bonded to the aromatic ring is less than 0.5 mol% in all the diamine components. The resin composition according to any one of 1) to 4) above is characterized by this.

[0014] 6). The polyimide contains a tetracarboxylic dianhydride having a fluorene structure as the tetracarboxylic dianhydride, and the ratio of the structure derived from the tetracarboxylic dianhydride having a fluorene structure to the total amount of the structures derived from the tetracarboxylic dianhydride is 50 to mol%. The resin composition according to any one of 1) to 5) above is characterized by this.

[0015] 7). The glass transition temperature (Tg) of the polycarbonate is 150 °C or higher. The resin composition according to any one of 1) to 6) above is characterized by this.

[0016] 8). The weight average molecular weight (Mw) of the polycarbonate is 50,000 or higher. The resin composition according to any one of 1) to 7) above is characterized by this.

[0017] 9). The polyimide and the polycarbonate are in the composition ratio (weight ratio) range of 2:98 to 98:2. The resin composition according to any one of 1) to 8) above is characterized by this.

[0018] 10) A molded article comprising the resin composition described in any one of items 1) to 9).

[0019] 11) A film comprising the resin composition described in any one of items 1) to 9). [Effects of the Invention]

[0020] Because the polyimide and polycarbonate contained in the resin composition are compatible, a transparent film with low haze can be obtained. Furthermore, because the polyimide resin and polycarbonate are compatible, coloration can be reduced without significantly decreasing the excellent mechanical strength of the polyimide, making it possible to produce a transparent film suitable for display cover films and the like. In addition, by using a highly environmentally biodegradable fluorine compound, a transparent film with low environmental persistence can be obtained. [Modes for carrying out the invention]

[0021] [Resin composition] The resin composition of the present invention comprises polyimide and polycarbonate. The polyimide is a polyimide resin composition having a structure derived from a tetracarboxylic dianhydride component and a diamine component. The diamine components are CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) n It is characterized by having a structure selected from - (where n is an integer from 1 to 20).

[0022] Furthermore, it is desirable that the tetracarboxylic dianhydride component includes an acid dianhydride selected from tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a fluorene structure, tetracarboxylic dianhydrides having a xanthene structure, and bis(trimellitic anhydride) esters.

[0023] <Polyimide> Polyimides are obtained by dehydrating and cyclizing polyamic acids, which are produced by the addition polymerization of tetracarboxylic dianhydrides (hereinafter sometimes referred to as "acid dianhydrides") and diamines. In other words, polyimides are polycondensates of tetracarboxylic dianhydrides and diamines, and have structures derived from acid dianhydrides (acid dianhydride components) and structures derived from diamines (diamine components).

[0024] The polyimide used in the present invention is preferably soluble in organic solvents, and preferably soluble in N,N-dimethylformamide (DMF) at a concentration of 1% by weight or more. The polyimide is particularly preferably soluble in non-amide solvents in addition to amide solvents such as DMF.

[0025] (acid dianhydride) The polyimide of the present invention preferably contains an acid dianhydride selected from an acid dianhydride having an ether bond, an acid dianhydride having a fluorene structure, an acid dianhydride having a xanthene structure, and a bis(trimellitic anhydride) ester. By having these acid dianhydride components, it is possible to obtain a molded article with improved solubility of the polyimide resin in solvents, improved compatibility between the polyimide resin and the polycarbonate resin, and an excellent balance of transparency and mechanical strength.

[0026] From the viewpoint of making the polyimide resin soluble in organic solvents, the total content of acid dianhydrides selected from acid dianhydrides having ether bonds, acid dianhydrides having a fluorene structure, acid dianhydrides having a xanthene structure, and / or bis(trimellitic anhydride) esters, relative to 100 mol% of the total amount of acid dianhydride components, is preferably 15 mol% or more, more preferably 20 mol% or more, even 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. The total content of acid dianhydrides selected from acid dianhydrides having ether bonds, acid dianhydrides having a fluorene structure, acid dianhydrides having a xanthene structure, and / or bis(trimellitic anhydride) esters, relative to 100 mol% of the total amount of acid dianhydride components, may be 100 mol%, 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.

[0027] Examples of acid dianhydrides containing an ether linkage include 3,4'-oxydiphthalic anhydride (a-ODPA), 4,4'-oxydiphthalic anhydride (s-ODPA), and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA). BPADA is particularly preferred from the viewpoint of solubility of polyimide resin and compatibility with polycarbonate. Using an acid dianhydride containing an ether linkage tends to improve the solubility of polyimide resin in solvents and the compatibility between polyimide resin and polycarbonate.

[0028] Examples of acid dianhydrides 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-isobenzofrancarboxamide] (FDA-ATA), and 5,5'-(9H-fluorene-9-ylidenedi-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofrancarboxamide] (FDA-ATA). Examples include mbiso(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate] (TBIS.MPN). From the viewpoint of polyimide solubility and compatibility with polycarbonate, BPAF or BPF-PA are particularly preferred. Using an acid dianhydride having a fluorene structure tends to improve the solubility of the polyimide resin in the solvent and the compatibility between the polyimide resin and polycarbonate.

[0029] Examples of acid dianhydrides having a xanthene structure include 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diirbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate (TBIS.RXN), spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride (SFDA), etc. Using acid dianhydrides having a xanthene structure tends to improve the solubility of polyimide resins in solvents and improve the compatibility between polyimide resins and polycarbonates.

[0030] The aforementioned acid dianhydrides having a xanthene structure also have a fluorene structure, and are acid dianhydrides having both a fluorene structure and a xanthene structure, tend to improve the solubility of polyimide resins in solvents and improve the compatibility between polyimide resins and polycarbonates.

[0031] Bis(trimellitic anhydride) esters are represented by the following general formula (1).

[0032] [ka]

[0033] In general formula (1), X is any divalent organic group, with carboxyl groups bonded to the carbon atoms of X at both ends. The carbon atoms bonded to the carboxyl groups may form a ring structure. Specific examples of divalent organic groups X are listed below (A) to (K).

[0034] [ka]

[0035] R in equation (A) 1 The group is a fluorine atom and an alkyl group having 1 to 20 carbon atoms, where m is an integer from 1 to 4. The group represented by formula (A) is a hydroquinone derivative having substituents on a benzene ring, with two hydroxyl groups removed. Examples of hydroquinones having substituents on a benzene ring include tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, and 2,5-di-tert-amylhydroquinone.

[0036] R in equation (B) 2 The group is a fluorine atom and an alkyl group having 1 to 20 carbon atoms, where n is an integer from 0 to 4. The group represented by formula (B) is a biphenol which may have substituents on the benzene ring, with two hydroxyl groups removed. Examples of biphenol derivatives having substituents 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, and 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diol.

[0037] The group represented by formula (C) is the group obtained by removing two hydroxyl groups from 4,4'-isopropylidenediphenol (bisphenol A). The group represented by formula (D) is the group obtained by removing two hydroxyl groups from resorcinol.

[0038] In formula (E), p is an integer from 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.

[0039] The group represented by formula (F) is a group obtained by removing two hydroxyl groups from 1,4-cyclohexanedimethanol.

[0040] 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 from 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 and the like. When having the structure of formula (G), it corresponds to both an acid dianhydride having a fluorene structure and a bis(anhydride trimellitic acid) ester, but in the present invention, it is considered to correspond to a bis(anhydride trimellitic acid) ester.

[0041] The bis(anhydride trimellitic acid) ester is preferably an aromatic ester. Among the above (A) to (K), (A), (B), (C), (D), (G), (H), and (I) are preferable for X. Among them, (A) to (D) are preferable, and the group having a biphenyl skeleton of (B) is particularly preferable. When X is a group represented by the 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).

[0042]

Chemical formula

[0043] The acidic dianhydride in general formula (1) where X is the 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).

[0044] [ka]

[0045] Among dianhydrides with ether bonds, dianhydrides with fluorene structures, dianhydrides with xanthene structures, and bis(trimellitic anhydride) esters, from the viewpoint of the solubility of the resulting polyimide resin in non-amide solvents, 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, and 9,9-bis(3,4-dicarboxyph Fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 5,5'-(9H-fluorene-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate], spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride, 5,5'-spiro[9 H-Fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate, p-phenylenebis(trimellitate anhydride)(TAHQ), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'diyl, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2, 2',3,3',5,5'-Hexamethylbiphenyl-4,4'-diyl (TAHMBP), 5,5'-(3,3'-dimethyl[1,1'-biphenyl]-4,4'-diyl)bis(1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate) (BP-TME), tert-butylhydroquinone bis(trimellitate anhydride) (TA.BHQ), trimethylhydroquinone bis(trimellitate anhydride) (TA.TMHQ) is preferred, and among these, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 5,5'-(9H-fluorene-9-ylidenebis(2-methyl-4,1 -Phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate], spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride, 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate), p-phenylenebis(trimellitate) More preferably, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride having a fluorene structure, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-di]di(di(di) Carboxyphenoxy)phenyl]fluorene dianhydride is more preferred. Also preferred are 5,5'-(9H-fluorene-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate] and spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride, which are preferred in that they possess both fluorene and xanthene structures.

[0046] From the viewpoint of ensuring compatibility with polycarbonate, the content of acid dianhydride having a fluorene structure relative to 100 mol% of the total amount of acid dianhydride components is preferably 30 mol% or more, more preferably 50 to 100 mol%, and even more preferably 80 to 100 mol%.

[0047] Among acid dianhydrides having a fluorene structure, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride is particularly preferred from the viewpoint of compatibility.

[0048] The polyimide used in the present invention may contain, as an acid dianhydride component, an acid dianhydride other than an acid dianhydride selected from the acid dianhydride having an ether bond, an acid dianhydride having a fluorene structure, or an acid dianhydride bis(trimellitic anhydride) ester having a xanthene structure. Examples of such acid dianhydride components include alicyclic tetracarboxylic acid dianhydrides, aromatic acid dianhydrides, and / or other acid dianhydrides.

[0049] 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, and 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]octa-7-en-2,3,5,6-tetracarboxylic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)- 1,2,3,4-Tetrahydronaphthalene-1,2-dicarboxylic acid 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 acid anhydride, 5,5'-[cyclohexylidenebis(4,1-phenyleneoxy)]bis-1,3-isobenzofrandione, 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.Examples include 0(2,7) dodecane-1,8:2,7-tetracarboxylic dianhydride, octahydro-1H,3H,8H,10H-biphenyleno[4a,4b-c:8a,8b-c']difuran-1,3,8,10-tetron, ethylene glycol bis(hydrogenated trimellitic anhydride) ester, decahydro[2]benzopyrano[6,5,4,-def][2]benzopyran-1,3,6,8-tetron, etc. The presence of an alicyclic structure in the acid dianhydride component tends to improve compatibility between polyimide resin and polycarbonate. The alicyclic tetracarboxylic dianhydride only needs to have at least one alicyclic structure, and may contain both an alicyclic and an aromatic ring in a single molecule. The alicyclic ring may be polycyclic and may have a spirostructure.

[0050] Among alicyclic tetracarboxylic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA-100), bicyclo[2.2.2]octa-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 dianhydride-3,4:3',4'-dianhydride (H-BPDA) are preferred from the viewpoint of polyimide transparency and mechanical strength. In particular, from the viewpoint of mechanical strength, tetracarboxylic anhydrides in which two acid anhydride groups are bonded to one alicyclic ring are preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride is especially preferred.

[0051] When using alicyclic tetracarboxylic dianhydrides, from the viewpoint of improving compatibility between polyimide resin and polycarbonate, and from the viewpoint of mechanical strength, the content of alicyclic tetracarboxylic dianhydrides relative to 100 mol% of the total amount of acid dianhydride components is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and may also be 10 mol% or more, 12 mol% or more, or 15 mol% or more. The amount of alicyclic tetracarboxylic dianhydride required to ensure compatibility with polycarbonate may vary depending on the type of polycarbonate and the amount of alicyclic tetracarboxylic dianhydride.

[0052] From the viewpoint of ensuring the solubility of polyimide resin in organic solvents, the content of alicyclic tetracarboxylic dianhydride relative to 100 mol% of the total amount of acid dianhydride components is preferably 80 mol% or less, more preferably 60 mol% or less, and may also be 50 mol% or less, 30 mol% or less, or may not be included at all. In order for polyimide resin to be compatible with polycarbonate even in low-boiling non-amide solvents (for example, halogenated solvents such as methylene chloride), the content of alicyclic tetracarboxylic dianhydride is preferably 60 mol% or less, more preferably 40 mol% or less, and may also be 20 mol% or less, or may not be included at all.

[0053] Aromatic acid dianhydrides include pyromellitic acid dianhydride (PMDA), 1,2,3,4-benzenetetracarboxylic acid dianhydride (MPDA), 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic acid dianhydride (a-BPDA), and 2,2',3,3'-biphenyltetracarboxylic acid dianhydride. Examples include i-BPDA (i-BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride (DSDA), 5,5'-dimethylmethylenebis(phthalic acid anhydride), 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, terphenyltetracarboxylic acid dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, and bis(3,4-dicarboxyphenyl)sulfone dianhydride. Among these aromatic acid dianhydrides, it is preferable to include at least one of the following, from the viewpoint of improving mechanical strength: 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, pyromellitic acid dianhydride, 1,2,3,4-benzenetetracarboxylic acid dianhydride, and 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride. Among these aromatic acid dianhydrides, it is preferable to include PMDA or s-BPDA from the viewpoint of compatibility with polycarbonate.

[0054] From the viewpoint of ensuring the solubility of polyimide resin in organic solvents, the content of aromatic acid dianhydrides relative to 100 mol% of the total amount of acid dianhydride components is preferably 80 mol% or less, more preferably 60 mol% or less, and may also be 50 mol% or less, 30 mol% or less, or may not be present at all. In order for polyimide resin to be compatible with polycarbonate even in low-boiling non-amide solvents (for example, halogenated solvents such as methylene chloride), the content of aromatic acid dianhydrides is preferably 60 mol% or less, more preferably 40 mol% or less, and may also be 20 mol% or less, or may not be present at all.

[0055] Other acidic dianhydrides that may be used include linear aliphatic acidic dianhydrides such as ethylenetetracarboxylic acid dianhydride and butanetetracarboxylic acid dianhydride.

[0056] (Diamine) The diamine component of the polyimide used in this invention is CF3-O-,-(CF2-O) n -, -O-(CF2-CF2-O) n The structure is selected from the following (where n is an integer from 1 to 20). By having such a structure in which the fluorinated methyl or fluorinated methylene structure is directly bonded to the oxygen atom, it is expected that the environmental decomposition of fluorine-containing compounds will be improved and the environmental persistence of fluorine-containing compounds will be significantly reduced.

[0057] CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) nExamples of diamines having a structure selected from the above (where n is an integer from 1 to 20) include perfluoroalkoxy-substituted benzidines. Examples of perfluoroalkoxy-substituted benzidines include 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(trifluoro(trifluoro)(trifluoro) Examples include methoxy)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, and 2,2',6,6'-tetrakis(trifluoromethoxy)benzidine.

[0058] CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) nOther examples of diamines having a structure selected from (where n is an integer from 1 to 20) include phenylenediamines having perfluoroalkoxy substitutions such as 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, and 1,4-diamino-2,3,5,6-tetrakis(trifluoromethoxy)benzene.

[0059] CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) n -Among the diamines having a structure selected from (where n is an integer from 1 to 20), CF3-O- or -(CF2-O) n Diamines having a trifluoromethoxy group (CF3-O-) are preferred, and from the viewpoint of polymerizability and mechanical strength of the polyimide, diamines having a trifluoromethoxy group (CF3-O-) are preferred, and among them, diamines in which the oxygen atom of the trifluoromethoxy group is bonded to the carbon atom of the aromatic ring are preferred, and from the viewpoint of reactivity, it is preferable that the fluorine atom, which is an electron-withdrawing group, is not directly bonded to the aromatic ring to which the amino group of the diamine is bonded. Examples of diamines in which a trifluoromethoxy group is bonded to the carbon atom of the aromatic ring include trifluoromethoxy-substituted benzidine and trifluoromethoxy-substituted phenylenediamine.

[0060] From the viewpoint of mechanical strength and polymerizability, perfluoroalkoxy-substituted benzidines are preferred. Among these, from the viewpoint of the solubility of the polyimide resin in organic solvents and compatibility with polycarbonate, perfluoroalkoxy-substituted benzidines having a perfluoroalkoxy group at the 2nd or 3rd position of biphenyl are preferred, with 2,2'-bis(trifluoromethoxy)benzidine (hereinafter referred to as "TFMOB"), 3,3'-bis(trifluoromethoxy)benzidine, and 2,3'-bis(trifluoromethoxy)benzidine being more preferred, and TFMOB being particularly preferred. By having a trifluoromethoxy group at the 2nd or 3rd position of biphenyl, in addition to the decrease in π electron density due to the electron-withdrawing properties of the trifluoromethoxy group, π-π stacking between benzene rings is inhibited due to the steric hindrance of the trifluoromethoxy group, so the absorption edge wavelength is shifted to a shorter wavelength, and the coloration of the polyimide can be reduced. Furthermore, the presence of trifluoromethoxy groups at the 2 and 2' positions causes steric hindrance to the bond between the two benzene rings of biphenyl, reducing the planarity of the π-conjugation. This shifts the absorption edge wavelength to a shorter wavelength, thereby reducing the coloration of the polyimide.

[0061] CF3-O-,-(CF2-O) n -, -O-(CF2-CF2-O) n The content of the diamine having a structure selected from - (where n is an integer from 1 to 20) is preferably 10 mol% or more, more preferably 30 mol% or more, even 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%. CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) n By including a diamine having a structure selected from - (where n is an integer from 1 to 20), discoloration of the film may be suppressed, and mechanical strength such as pencil hardness, elastic modulus, breaking strength, and elongation at break may be improved.

[0062] Polyimides have CF3-O- and -(CF2-O) as diamine components. n-, -O-(CF2-CF2-O) n -May contain diamines that do not have a structure selected from (where n is an integer from 1 to 20). CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) nExamples of diamines that do not have a structure selected from (where n is an integer from 1 to 20) 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, and 4,4'-diaminodiphenylsulfone. Lufon, 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-di(3-aminophenyl)propane, 2,2-di(4-aminophenyl)propane, 2-(3-aminophenyl) -2-(4-aminophenyl)propane, 1,1-di(3-aminophenyl)-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 n, 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-dimethyl [Benzyl]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]diphenyl Lusulfone, 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'-spirobindan, 6,6'-bis(4-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobindan, 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-aminoprothoxy)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-amino Examples include propyl 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, etc. ,

[0063] For example, as diamines, CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) nIn addition to diamines having a structure selected from the above (where n is an integer from 1 to 20), using diaminodiphenylsulfone may improve the solubility and transparency of the polyimide resin in solvents. Among diaminodiphenylsulfones, 3,3'-diaminodiphenylsulfone (3,3'-DDS) and 4,4'-diaminodiphenylsulfone (4,4'-DDS) are preferred. 3,3'-DDS and 4,4'-DDS may be used in combination.

[0064] The content of diaminodiphenylsphone relative to 100 mol% of the total amount of diamine may be 1-80 mol%, 3-75 mol%, or 5-60 mol%.

[0065] It is particularly preferable to include, as the tetracarboxylic dianhydride component, one or more acidic dianhydrides selected from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride and 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, which are tetracarboxylic dianhydrides having a fluorene structure, and as the diamine component, one or more diamines selected from 2,2'-bis(trifluoromethoxy)benzidine, 3,3'-bis(trifluoromethoxy)benzidine and 2,3'-bis(trifluoromethoxy)benzidine. If other tetracarboxylic dianhydride components or diamine components are included, it is preferable to include a tetracarboxylic dianhydride component selected from PMDA and s-BPDA and / or a diamine component selected from 3,3'-DDS and 4,4'-DDS.

[0066] For example, as diamines, CF3-O-, -(CF2-O) n -, -O-(CF2-CF2-O) nIn addition to diamines having a structure selected from the above (where n is an integer from 1 to 20), using a diamine containing fluorene may improve the solubility of the polyimide resin in solvents, its compatibility with polycarbonate, its transparency, and its mechanical strength. Preferred fluorene-containing diamines include 9,9-bis(4-aminophenyl)fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, and 9,9-bis(4-amino-3-methylphenyl)fluorene, and these may be used in combination.

[0067] The content of fluorene-containing diamine relative to 100 mol% of the total diamine may be 1-40 mol%, 3-30 mol%, or 5-25 mol%.

[0068] In order to obtain a polyimide in which the environmental degradability of fluorine-containing compounds is improved and the environmental persistence of fluorine-containing compounds is significantly reduced, the total amount of fluorine atoms contained in acid dianhydrides having a specific fluorine structure and diamines having a specific fluorine structure is preferably less than 500 mg, more preferably less than 300 mg, more preferably less than 100 mg, and even more preferably less than 50 mg per 1 kg of polyimide resin. Here, diamines having a specific fluorine structure refer to acid dianhydrides having a completely fluorinated methyl group (CF3-) or methylene group (-CF2-), and diamines having a completely fluorinated methyl group (CF3-) or methylene group (-CF2-), excluding substances that contain only the structural elements of the following structural formulas (1) or (2). CF3-X (1) X-CF2-X' (2) (However, X is an -OR or -NRR' structure, X' is one of -H, -CH3, aromatic, -C(O)-, -OR'', -SR'', NR''R''', and R, R', R'', R''' is one of -H, -CH3, -CH2-, aromatic, -C(O)-)

[0069] More preferably, the content of tetracarboxylic dianhydride components having a CF3- group directly attached to the aromatic ring or a -C(CF3)2- group directly attached to the aromatic ring is less than 0.5 mol% of the total tetracarboxylic dianhydride components, and the content of diamine components having a CF3- group directly attached to the aromatic ring or a -C(CF3)2- group directly attached to the aromatic ring is less than 0.5 mol% of the total diamine components. Examples of acid dianhydrides and diamines having a CF3- group directly attached to an aromatic ring or a -C(CF3)2- group directly attached to an aromatic ring include 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 9,9-bis(trifluoromethyl)xanthenetetracarboxylic acid dianhydride, 9-bis(trifluoromethyl)xanthenetetracarboxylic acid dianhydride, 2,2'-bis(trifluoromethyl)benzidine, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane.

[0070] (Preparation of polyimide) The reaction of an acidic dianhydride with a diamine yields polyamic acid as a polyimide precursor, and the dehydration and cyclization (imidization) of the polyamic acid yields polyimide. As described above, by adjusting the composition of the polyimide, i.e., the type and ratio of the acidic dianhydride and diamine, the polyimide can be made transparent, soluble in organic solvents, and compatible with polycarbonate.

[0071] The method for preparing polyamic acid is not particularly limited, and any known method can be applied. For example, a polyamic acid solution can be obtained by dissolving an acidic dianhydride and a diamine in approximately equimolar amounts (molar ratio of 95:100 to 105:100) in an organic solvent and stirring. The concentration of the polyamic acid solution is usually 5 to 35% by weight, preferably 10 to 30% by weight. When the concentration is within this range, the polyamic acid obtained by polymerization has an appropriate molecular weight, and the polyamic acid solution has an appropriate viscosity.

[0072] In the polymerization of polyamic acids, it is preferable to add the dianhydride to the diamine to suppress ring-opening of the dianhydride. When adding multiple types of diamines or dianhydrides, they may be added all at once or in multiple steps. The properties of the polyimide can also be controlled by adjusting the order of monomer addition.

[0073] The organic solvent used for polymerization of polyamic acid is not particularly limited, as long as it does not react with diamines and acidic dianhydrides and can dissolve polyamic acid. Examples of organic solvents include urea-based solvents such as methylurea and N,N-dimethylethylurea; sulfoxide or sulfone-based solvents such as dimethyl sulfoxide, diphenyl sulfone, and tetramethylsulfone; amide-based solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), N,N'-diethylacetamide, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, and hexamethylphosphate triamide; alkyl halide-based solvents such as chloroform and methylene chloride; aromatic hydrocarbon-based solvents such as benzene and toluene; and ether-based solvents such as tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, dimethyl ether, diethyl ether, and p-cresol methyl ether. These solvents are usually used individually or in appropriate combinations of two or more as needed. From the viewpoint of polyamic acid solubility and polymerization reactivity, DMAc, DMF, NMP, etc., are preferably used.

[0074] Polyimides can be obtained by the dehydration and cyclization of polyamic acids. One method for preparing polyimides from a polyamic acid solution is to add a dehydrating agent, an imidation catalyst, etc., to the polyamic acid solution and allow imidation to proceed in the solution. The polyamic acid solution may be heated to accelerate the progression of imidation. By mixing the solution containing the polyimide produced by the imidation 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, as well as residual dehydrating agents and imidation catalysts, can be washed and removed with the poor solvent, preventing discoloration and increased yellowness of the polyimide. Furthermore, by isolating the polyimide resin as a solid, solvents suitable for film formation, such as low-boiling point solvents, can be applied when preparing the solution for film production.

[0075] The molecular weight of the polyimide (weight-average molecular weight in terms of polyethylene oxide, measured by gel filtration chromatography (GPC)) is preferably 10,000 to 1,000,000, more preferably 20,000 to 500,000, and even more preferably 40,000 to 300,000. If the molecular weight is too low, the film strength may be insufficient. If the molecular weight is too high, the compatibility with polycarbonate may be poor.

[0076] Polyimide is preferably soluble in solvents, particularly soluble in non-amide solvents such as ketone solvents and alkyl halide solvents, and even more preferably soluble in methylene chloride. Solubility in solvents is preferably observed at 60°C or below, more preferably at 40°C or below, and even more preferably at 23°C or below. Solubility in a solvent means that the polyimide dissolves at a concentration of 1% by weight or more. Non-amide solvents have lower boiling points compared to amide solvents, and residual solvent can be easily removed during film production. Therefore, using polyimide resins that dissolve in non-amide solvents can be expected to improve film productivity.

[0077] From the viewpoint of thermal and light stability of the resin composition and film, polyimide is preferably low in reactivity. The acid value of 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 polyimide may also 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, polyimide is preferably high in imidization rate. A low acid value tends to improve the stability of polyimide and its compatibility with polycarbonate.

[0078] <Polycarbonate> The polycarbonate as used in this application refers to a polymer in which the bonding sites between monomer units are linked by carbonate bonds (-O-(C=O)-O-).

[0079] The preferred weight-average molecular weight of polycarbonate is 5,000 to 200,000, more preferably 10,000 to 100,000, and even more preferably 15,000 to 50,000, from the viewpoint of balancing compatibility with polyimide and the strength of the molded article. Furthermore, using polycarbonate with a weight-average molecular weight of 50,000 or more tends to improve mechanical strength. Specifically, TEIJIN's Panlight 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-22 Examples include 50Z, MN-4800, MN-4800Z, MN-4805Z, Yupiron K4100, ML200, ML300, ML400 from Mitsubishi Engineering Plastics, APEC1695, APEC1697, APEC1795, APEC1797, APEC1895, APEC1897, APEC2095, APEC2097, APEC9351, APEC9371 from Covestro, and PCZ-200, FPC-0820, FPC-0220, FPC8225, FPC2136, FPC0330, FPC-F124 from Mitsubishi Gas Chemical.

[0080] As raw material monomers for constituting polycarbonate without losing the effects of the present invention, 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) 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) hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) sulfone, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 6,6'-dihydroxy-3,3,3',3'-tetramethylspiro(bis)indan, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxyanthrene, 2,7-dihydroxyphenoxatine, 2,7-dihydroxy-9,10-dimethylphenazine, 3,6-dihydroxybenzofuran, 3,6-dihydro It may contain xyanthrene, 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, etc.

[0081] Furthermore, the X in general formula (2) can include an annular structure to the extent that the effects of the present invention are not lost. X can include fluorene skeletons, phthalimide skeletons, and alicyclic skeletons such as cyclohexylmethylidene, 1,1-ethene, 2-[2.2.1]-bicycloheptylidene, cyclohexylidene, cyclopentylidene, cyclododecylidene, and adamantylidene. Specifically, examples of dihydric alcohols constituting polycarbonates 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 4,4'-(3,3,5-trimethylcyclohexylidene)diphenol.

[0082] [ka]

[0083] From the viewpoint of the heat resistance of the film, the glass transition temperature of polycarbonate is preferably 100°C or higher, more preferably 120°C or higher, and may be 150°C or higher or 180°C or higher.

[0084] <Preparation of resin composition> A resin composition is prepared by mixing the above-mentioned polyimide resin and polycarbonate. Since the above-mentioned polyimide resin and polycarbonate can be compatible in any ratio, the ratio of polyimide resin to polycarbonate in the resin composition is not particularly limited. The mixing ratio (by weight) of polyimide resin to polycarbonate may be 98:2 to 2:98, 95:5 to 10:90, or 90:10 to 15:85. The higher the proportion of polyimide resin, the higher the elastic modulus of the film tends to be, and the better the mechanical strength tends to be. The higher the proportion of polycarbonate, the less coloration the film tends to have and the higher its transparency tends to be.

[0085] In order to fully realize the effect of improving transparency by mixing polyimide and polycarbonate, the ratio of polycarbonate to the total of polyimide and polycarbonate 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.

[0086] Polyimides are polymers with a unique molecular structure, and generally have low solubility in organic solvents and poor compatibility with other polymers. In this invention, by using a specific polyimide, high solubility in organic solvents and compatibility with polycarbonate are achieved.

[0087] Resin compositions containing polyimide and polycarbonate preferably have a single glass transition temperature in suggested scanning calorimetry (DSC) and / or dynamic viscoelasticity measurement (DMA). When a resin composition has a single glass transition temperature, the polyimide and polycarbonate can be considered to be perfectly miscible. Films containing polyimide and polycarbonate also preferably have a single glass transition temperature.

[0088] The resin composition may simply be a mixture of polyimide and polycarbonate precipitated as solid components, or it may be a mixture of polyimide and polycarbonate. Alternatively, when precipitating polyimide resin by mixing a polyimide solution with a poor solvent, polycarbonate may be mixed into the solution to precipitate a resin composition of polyimide and polycarbonate as a solid (powder).

[0089] The resin composition may be a mixed solution containing polyimide resin and polycarbonate. The method of mixing the resins is not particularly limited; they may be mixed in a solid state or mixed in a liquid to form a mixed solution. A polyimide resin solution and a polycarbonate solution may be prepared separately, and then the two may be mixed to prepare a mixed solution of polyimide resin and polycarbonate.

[0090] The solvent for a solution containing polyimide resin and polycarbonate is not particularly limited as long as it is soluble in both the polyimide resin and polycarbonate. Examples of solvents 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 methylcyclohexanone; and alkyl halogenated solvents such as chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, dichlorobenzene, and methylene chloride.

[0091] In terms of the solubility of polyimide resin and the compatibility of polyimide resin with polycarbonate in solution, amide solvents are preferred. On the other hand, in terms of the ease of solvent removal when producing molded articles such as films, low-boiling-point non-amide solvents are preferred. Ketone solvents and alkyl halogenate solvents are preferred because they have excellent solubility for both polyimide resin and polycarbonate, have low boiling points, and allow for easy removal of residual solvent during film production.

[0092] The resin composition may contain organic or inorganic low-molecular-weight compounds, high-molecular-weight compounds (e.g., epoxy resins), etc. The resin composition may also contain flame retardants, ultraviolet absorbers, crosslinking agents, dyes, pigments, surfactants, leveling agents, plasticizers, fine particles, sensitizers, etc. The fine particles may include organic fine particles such as polystyrene and polytetrafluoroethylene, and inorganic fine particles such as colloidal silica, carbon, and layered silicates, and may have a porous or hollow structure. The fiber reinforcing material may include carbon fibers, glass fibers, aramid fibers, etc.

[0093] [Molded articles and films] The above composition can be used to form various molded articles. Molding methods include injection molding, transfer molding, press molding, blow molding, inflation molding, calendering, and melt extrusion. Resin compositions containing polyimide and polycarbonate tend to have a lower melt viscosity than polyimide alone and exhibit excellent moldability in injection molding, transfer molding, press molding, and melt extrusion.

[0094] Furthermore, solutions of resin compositions containing polyimide and polycarbonate tend to have lower viscosity than solutions of polyimide alone at the same solid content concentration. Therefore, they offer excellent handling advantages, such as easier transport of the solution, high coating properties, and are advantageous in reducing film thickness variations.

[0095] In one embodiment, the molded body is a film. The film may be formed by either a melting method or a solution method, but the solution method is preferred from the viewpoint of producing a film with excellent transparency and uniformity. In the solution method, a film is obtained by coating a solution containing the above-mentioned polyimide resin and polycarbonate onto a support and drying off the solvent.

[0096] As a method for applying the resin solution onto the support, known methods using bar coaters, comma coaters, etc., can be applied. As the support, glass substrates, metal substrates such as SUS, metal drums, metal belts, plastic films, etc., can be used. From the viewpoint of improving productivity, it is preferable to use an endless support such as a metal drum or metal belt, or a long plastic film, as the support and manufacture the film by roll-to-roll. When using a plastic film as the support, a material that does not dissolve in the film-forming doping solvent should be appropriately selected.

[0097] Heating is preferable when drying the solvent. The heating temperature is not particularly limited as long as it can remove the solvent and suppress discoloration of the resulting film, and can be appropriately set between room temperature and approximately 250°C, with 50°C to 220°C being preferred. The heating temperature may be increased in stages. To improve the efficiency of solvent removal, the resin film may be peeled from the support and dried after a certain degree of drying has progressed. Heating may be performed under reduced pressure to promote solvent removal.

[0098] Furthermore, molded articles formed from a resin composition containing polyimide and polycarbonate from a solution tend to have a lower glass transition temperature compared to molded articles formed from a solution of polyimide alone of the same shape. Therefore, when processed under the same heating conditions, the amount of residual solvent in the molded article tends to be lower. In particular, when using amide-based high-boiling point solvents, high-temperature heating of 250°C or higher or 300°C or higher may be required to remove the solvent, which may reduce the transparency of the resulting molded article. However, because the amount of residual solvent tends to be lower under the same heating conditions, discoloration during heating is suppressed, and it is easier to obtain molded articles with high transparency.

[0099] Polycarbonate films may have low mechanical strength, including toughness, modulus of elasticity, and hardness. However, the strength of the film can be improved by using a compatible system of polyimide and polycarbonate. The film may be stretched in one or more directions to improve its mechanical strength. When a film is stretched, the polymer chains orient themselves in the stretching direction, increasing the tensile modulus of elasticity in the stretching direction. This, in turn, improves mechanical strength and tends to suppress cracking and fractures in the film.

[0100] For example, films used as cover films or substrate materials for foldable displays require high mechanical strength in the direction perpendicular to the bending axis because they are repeatedly folded along the bending axis at the same point. Therefore, by arranging the film so that its stretching direction is perpendicular to the bending axis, cracks and breaks are less likely to occur at the bending point even after repeated folding, providing a device with high bending resistance.

[0101] The stretching conditions for the film are not particularly limited. For example, the stretching temperature is approximately ±40°C of the film's glass transition temperature and may be around 120-300°C, 150-250°C, or 180-230°C. The stretching ratio is approximately 1-200%, and may be 5-150%, 10-120%, or 20-100%. The larger the stretching ratio, the greater the tensile modulus in the stretching direction tends to be. On the other hand, if the stretching ratio is excessively large, the mechanical strength in the direction perpendicular to the stretching direction tends to decrease, which may reduce the handling properties of the film.

[0102] From the viewpoint of increasing strength in any direction within the plane, the film may be biaxially stretched. 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 direction perpendicular to it may be the same or different. If there is a difference in the stretching ratio, the mechanical strength tends to be relatively higher in the direction with the larger stretching ratio. When using a biaxially stretched film with anisotropic stretching ratio in a foldable device, it is preferable to position the direction with the larger stretching ratio perpendicular to the folding axis.

[0103] The film thickness is not particularly limited and can be set appropriately depending on the application. For example, the film thickness is 5 to 300 μm. From the viewpoint of achieving both self-supporting properties and flexibility, and a highly transparent film, the film thickness is preferably 20 μm to 200 μm, but may also be 30 μm to 150 μm, 40 μm to 100 μm, or 50 μm to 80 μm. For use as a cover film for displays, the film thickness is preferably 10 μm or more. When stretching the film, it is preferable that the thickness after stretching is within the above range.

[0104] The haze of the film is preferably 10% or less, more preferably 5% or less, even more preferably 4% or less, and may be 3.5% or less, 3% or less, 2% or less, or 1% or less. The lower the haze of the film, the better. As described above, polyimide and polycarbonate are compatible, so a film with low haze and high transparency can be obtained. The resin composition obtained by mixing polyimide and polycarbonate preferably has a haze of 10% or less when a film with a thickness of 50 μm is made.

[0105] The yellowness (YI) of the film is preferably 5.0 or less, but may also be 4.0 or less, 3.0 or less, 2.0 or less, 1.5 or less, or 1.0 or less. The resin composition obtained by mixing polyimide and polycarbonate preferably has a yellowness of 5.0 or less when a film with a thickness of 50 μm is produced. As described above, by mixing polyimide and polycarbonate, a film with less coloration and a lower YI can be obtained compared to when polyimide is used alone.

[0106] From the viewpoint of strength, the tensile modulus of the film is preferably 2.5 GPa or higher, more preferably 3.0 GPa or higher, and may also be 4.0 GPa or higher. The pencil hardness of the film is preferably 4B or higher, more preferably 2B or higher, even more preferably F or higher, and may also be H or higher, 2H or higher, or 3H or higher. In compatible systems of polyimide and polycarbonate, increasing the proportion of polycarbonate tends not to significantly decrease the pencil hardness. Therefore, it is possible to provide a film with less discoloration and excellent transparency without significantly reducing the excellent mechanical strength characteristic of polyimide.

[0107] Films formed from resin compositions containing polyimide and polycarbonate are suitable for use as display materials due to their low coloration and high transparency. In particular, films with high mechanical strength can be applied to surface components such as display cover windows. For practical use, the film of the present invention may be provided with an antistatic layer, an easy-adhesion layer, a hard coat layer, an anti-reflective layer, etc., on its surface. [Examples]

[0108] The embodiments of the present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following embodiments.

[0109] [Examples of polyimide resin production] Dimethylformamide (DMF) was placed in a separable flask and stirred under a nitrogen atmosphere. Diamine and acidic dianhydride were then added in the PI composition (mol%) shown in Table 1, and the mixture was stirred under a nitrogen atmosphere for 5 to 48 hours to obtain a polyamic acid solution with a solid content of 18% by weight.

[0110] To 100 g of polyamic acid solution, 5.5 g of pyridine was added as an imidation catalyst 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, 100 g of 2-propyl alcohol (hereinafter referred to as IPA) was added at a rate of 2-3 drops / second while stirring the solution to precipitate polyimide. Further 150 g of IPA was added and stirred for about 30 minutes, after which suction filtration was performed using a Kiriyama funnel. The obtained solid was washed with IPA and then dried in a vacuum oven set to 120°C for 12 hours to obtain polyimide resin.

[0111] [Film production example] <Examples 1-4, Comparative Examples 1-4> A DMF solution with a resin content of 10% by weight was prepared by mixing dimethylformamide (DMF) with polyimide (PI) obtained in the above polyimide resin production example and commercially available polycarbonate PCZ-200 (manufactured by Mitsubishi Gas Chemical, glass transition temperature = 175°C, hereafter PC1) or FPC-2136 (manufactured by Mitsubishi Gas Chemical, weight-average molecular weight = 61,000, glass transition temperature = 131°C, hereafter PC2) in a 50:50 weight ratio. This solution was applied to an alkali-free glass plate and heated and dried in an air atmosphere for 15 minutes at 60°C, 90°C, 120°C, 15 minutes at 150°C, 15 minutes at 180°C, and 200°C to produce a film.

[0112] [evaluation] <Haze> The film was cut into 3cm squares, and the haze was measured using a Suga Test Instruments HZ-V3 haze meter in accordance with JIS K7136 and JIS K7361-1.

[0113] <(Total light) transmittance> The film was cut into 3cm squares, and the total light transmittance (%) was measured using a Suga Test Instruments HZ-V3 haze meter in accordance with JIS K7136 and JIS K7361-1.

[0114] <Yellowness (YI)> The film was cut into 3cm squares, and the yellowness (YI) was measured according to JIS K7373 using a Suga Test Instruments SC-P spectrophotometer.

[0115] <Tensile modulus> The film was cut into strips 10 mm wide, allowed to stand for 1 day at 23°C / 55%RH to adjust humidity, and then its tensile modulus was measured using Shimadzu Corporation's "AUTOGRAPH AGS-X" under the following conditions. Distance between gripping parts: 100mm Tensile speed: 20.0 mm / min Measurement temperature: 23℃

[0116] [Evaluation Results] Table 1 shows the resin composition (polyimide composition, polycarbonate type, and mixing ratio) and the film evaluation results.

[0117] In Table 1, the compounds are listed using the following abbreviations. <Acid dianhydride> BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride PMDA: Pyromelit acid dianhydride BPAF: 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride BPADA: 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride

[0118] <Diamine> TFMOB: 2,2'-Bis(trifluoromethoxy)benzidine 3,3'-DDS:3,3'-diaminodiphenylsulfone 4,4'-ODA:4,4'-diaminodiphenyl ether

[0119] When the properties of the film obtained in Example 1 (cast in DMF solvent with PI:PC1=50:50) were measured, the total light transmittance was 89.4%, the haze was 0.75, and the yellowness (YI) was 2.52.

[0120] These results indicate that in Examples 1-4, the polyimide contains an acid dianhydride having an ether bond or an acid dianhydride having a fluorene structure as the tetracarboxylic dianhydride component, and the diamine component is CF3-O-,-(CF2-O) n -, -O-(CF2-CF2-O) n It can be seen that by including a diamine having a structure selected from (where n is an integer from 1 to 20), a film with high compatibility between polyimide and polycarbonate and high transparency can be obtained. [Table 1]

Claims

1. It contains polyimide and polycarbonate. The polyimide is a polyimide resin composition having a structure derived from a tetracarboxylic dianhydride component and a diamine component, wherein the diamine is CF ３ -O-, -(CF ２ -O) ｎ -, -O-(CF ２ -CF ２ -O) ｎ A resin composition characterized by containing a diamine having one or more structures selected from any of the following (where n is an integer from 1 to 20).

2. The resin composition according to claim 1, characterized in that the tetracarboxylic dianhydride component includes one or more acidic dianhydrides selected from tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a fluorene structure, tetracarboxylic dianhydrides having a xanthene structure, and bis(trimellitic anhydride) esters.

3. One or more acidic dianhydrides selected from the ether-bonded tetracarboxylic dianhydrides, fluorene-containing tetracarboxylic dianhydrides, xanthene-containing tetracarboxylic dianhydrides, and bis(trimellitic anhydride) esters include 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, and 9,9-bis(3,4-dicarboxyphenyl ) Fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 5,5'-(9H-fluorene-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate],spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride, 5,5'-spiro[9H-fluorene-9,9' The resin composition according to claim 2, comprising at least one of -[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate, p-phenylenebis(trimellitate anhydride), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'diyl, and bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'diyl.

4. The above CF ３ -O-, -(CF ２ -O) ｎ -,-O-(CF ２ -CF ２ -O) ｎ -selected diamine having a structure (where n is an integer from 1 to 20) is selected from 2,2'-bis(trifluoromethoxy)benzidine, 3,3'-bis(trifluoromethoxy)benzidine, 2,3'-bis(trifluoromethoxy)benzidine, The resin composition according to claim 1, characterized in that

5. CF directly connected to the aromatic ring of the aforementioned polyimide ３ - Directly attached to the group or aromatic ring - C (CF ３ ) ２ The content of tetracarboxylic dianhydride components having - is less than 0.5 mol% of the total tetracarboxylic dianhydride components. CF directly connected to the aromatic ring of the polyimide resin composition ３ - Directly attached to the group or aromatic ring - C (CF ３ ) ２ The resin composition according to claim 1, characterized in that the content of the diamine component having - is less than 0.5 mol% of the total diamine components.

6. The resin composition according to claim 1, wherein the polyimide includes a tetracarboxylic dianhydride having a fluorene structure as the tetracarboxylic dianhydride, and the ratio of the structure derived from the tetracarboxylic dianhydride having a fluorene structure to the total amount of the structure derived from the tetracarboxylic dianhydride is 50 to 100 mol%.

7. The resin composition according to claim 1, characterized in that the glass transition temperature (Tg) of the polycarbonate is 150°C or higher.

8. The resin composition according to claim 1, characterized in that the weight-average molecular weight (Mw) of the polycarbonate is 50,000 or more.

9. The resin composition according to claim 1, wherein the polyimide and the polycarbonate are in a composition ratio (weight ratio) in the range of 2:98 to 98:

2.

10. A molded article comprising the resin composition according to any one of claims 1 to 9.

11. A film comprising the resin composition according to any one of claims 1 to 9.

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