Resin composition, molded body, and film

Abstract

This resin composition contains a polyamideimide and a polyester. The polyester has a weight average molecular weight of more than 10,000. The polyamideimide contains a diamine having a fluorene structure as a diamine component and contains one or more types selected from the group consisting of a bisphenol type tetracarboxylic acid dianhydride, a bis(trimellitic anhydride) ester, and a tetracarboxylic acid dianhydride having a fluorene structure as a tetracarboxylic acid dianhydride component. As the polyamideimide and the polyester are compatible, a molded body formed from the resin composition, such as a film, exhibits high transparency.

Description

Resin composition, molded article and film

[0001] The present invention relates to a resin composition, a molded article, and a film.

[0002] There is a demand for thinner, lighter, and more flexible electronic devices, such as display devices including liquid crystal displays, organic electroluminescence displays, and electronic paper, as well as solar cells and touch panels. By replacing the glass materials used in these devices with film materials, flexibility, thinner, and lighter devices can be achieved. Transparent polyimide films have been developed as glass replacement materials and are used for display substrates, cover films, and the like. Patent Document 1 proposes using polyamideimide as a material for cover films for flexible displays.

[0003] Although polyimide and polyamideimide have superior heat resistance compared to general-purpose resins, higher transparency is required when they are used as cover films for displays, etc. As a method for improving the transparency, etc. of polyamideimide films, the use of a resin composition in which polyamideimide is mixed with other resins has been proposed. Patent Document 2 proposes a resin composition in which polyamideimide is mixed with an acrylic resin, and Patent Document 3 proposes a resin composition in which polyamideimide is mixed with polycarbonate.

[0004] International Publication No. 2013 / 048126 International Publication No. 2023 / 132310 Japanese Patent Application Laid-Open No. 2023-159875

[0005] Patent Documents 1 to 3 use solvent-soluble polyamideimides containing fluoroalkyl-substituted benzidines such as 2,2'-bis(trifluoromethyl)benzidine (TFMB) as diamines. Polyamideimides using fluorine-containing compounds as diamines and / or tetracarboxylic dianhydrides have excellent transparency and solvent solubility.

[0006] On the other hand, in recent years, the environmental persistence of organic fluorine compounds (PFAS) has become a problem. In general, the carbon-fluorine bond contained in organic fluorine compounds has high bond energy and is difficult to decompose in the environment. In particular, the structure in which a trifluoromethyl group is bonded to a carbon atom (-C-CF ３ ), or a structure in which carbon atoms are bonded to both ends of a difluoromethylene group (—C—CF ２ Organic fluorine compounds containing fluorine atoms (C) have low decomposition properties in the environment and have been reported to have adverse effects on the human body.

[0007] In view of the above problems, the present invention aims to provide a molded article such as a film containing polyamideimide, which is environmentally safe and highly transparent, and a resin composition used for producing the same.

[0008] The present invention relates to a resin composition containing a polyamideimide and a polyester, and a molded article such as a film containing the resin composition. The polyamideimide contains, as a diamine component, a diamine having a fluorene structure, and, as a tetracarboxylic dianhydride component, one or more tetracarboxylic dianhydrides (specific acid dianhydrides) selected from the group consisting of bisphenol-type tetracarboxylic dianhydrides, bis(trimellitic anhydride) esters, and tetracarboxylic dianhydrides having a fluorene structure.

[0009] The ratio of the diamine having a fluorene structure to the total amount of the diamine-derived structure (diamine component) of the polyamideimide is preferably 50 mol % or more. The ratio of the specific acid dianhydride to the total amount of the tetracarboxylic acid dianhydride-derived structure (acid dianhydride component) of the polyamideimide is preferably 50 mol % or more.

[0010] A preferred example of the diamine having a fluorene structure is 9,9-bis(4-aminophenyl)fluorene.

[0011] Preferred examples of the specific acid dianhydride include 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 1,4-phenylenebis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate), 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate), bisphenol Z bis(trimellitic anhydride), 5,5'-[cyclododecylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate), 5,5'-spiro[9H-fluoro] fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate), 5,5'-[9H-fluoren-9-ylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate), 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, and spiro[11H-difuro[3,4-b:3',4'-i]xanthene-11,9'-fluorene]-1,3,7,9-tetraone.

[0012] In the polyamideimide, it is preferred that the ratio of fluorine atom-containing diamine to the total amount of diamine components is less than 10 mol %, the ratio of fluorine atom-containing tetracarboxylic acid dianhydride to the total amount of acid dianhydride components is less than 10 mol %, and the ratio of fluorine atom-containing polybasic acid-derived structures to the total amount of polybasic acid-derived structures is less than 10 mol %.

[0013] The weight-average molecular weight of the polyester is greater than 10,000. The polyester preferably contains, as a diol component, at least one selected from the group consisting of diols having a chain alkylene group having 3 or more carbon atoms which may be branched, diols having a chain alkenylene group having 3 or more carbon atoms which may be branched, polyalkylene glycols, and diols having a cyclic structure.

[0014] Among the above diols, diols having a fluorene structure and diols having a bisphenol derivative structure are preferred. Examples of diols having a bisphenol derivative structure include bisphenol alkylene oxide adducts such as bisphenol EO adducts and bisphenol PO adducts.

[0015] The resin composition may contain polyamideimide and polyester in a weight ratio ranging from 98:2 to 2:98.

[0016] The composition can be used to form a molded article such as a film. The film may be a stretched film stretched in at least one direction. The film may have an in-plane birefringence ΔN and a thickness-direction birefringence ΔP of less than 0.02. The film may have anisotropy in the tensile modulus in the plane.

[0017] Molded articles such as films formed from the resin composition of the present invention have high light transmittance and excellent transparency. In addition, since the polyamideimide contains a specific diamine and a specific tetracarboxylic dianhydride, and the polyamideimide and polyester are compatible with each other without substantially using a fluorine atom-containing monomer, the resin composition has low environmental residue and excellent environmental safety.

[0018] [Resin Composition] One embodiment of the present invention is a compatible resin composition containing polyamideimide and polyester. Due to the compatibility between polyamideimide and polyester, a molded article such as a film formed from the resin composition exhibits transparency.

[0019] [Polyamideimide] Polyamideimide is a polymer having an imide structural unit represented by general formula (I), an amide structural unit represented by general formula (II), and / or an amideimide structural unit represented by general formula (III).

[0020]

[0021] In general formulas (I) to (III), X is a tetravalent organic group, Y and Z are divalent organic groups, and W is a trivalent organic group. Y is a diamine residue, which is an organic group obtained by removing two amino groups from a diamine represented by the following general formula (V). X is a tetracarboxylic dianhydride (hereinafter sometimes referred to as "acid dianhydride") residue, which is an organic group obtained by removing two carboxy anhydride groups from a tetracarboxylic dianhydride represented by the following general formula (IV). Z is a dicarboxylic acid residue, which is an organic group obtained by removing two carboxy groups from a dicarboxylic acid represented by the following general formula (VI). W is a tricarboxylic acid anhydride residue, which is an organic group obtained by removing a carboxy anhydride group and a carboxy group from a tricarboxylic acid anhydride represented by the following general formula (VII).

[0022]

[0023] In other words, the polyamide-imide contains a diamine-derived structure represented by the following general formula (Va) and a tetracarboxylic dianhydride-derived structure represented by the following general formula (IVa), and further contains one or more structures selected from the group consisting of a dicarboxylic acid-derived structure represented by the following general formula (VIa) and a tricarboxylic acid anhydride-derived structure represented by the following general formula (VIIa): The diamine-derived structure (Va) and the tetracarboxylic dianhydride-derived structure (IVa) form an imide bond to form an imide structural unit represented by the general formula (I), the diamine-derived structure (Va) and the dicarboxylic acid-derived structure (VIa) form an amide bond to form an amide structural unit represented by the general formula (II), and the carboxy anhydride group moiety and the carboxy group moiety of the tricarboxylic acid anhydride-derived structure (VIIa) form an imide bond and an amide bond, respectively, with the diamine-derived structure (Va), to form an amide-imide structural unit represented by the general formula (III).

[0024]

[0025] The polyamideimide may contain multiple types of diamine residues Y, multiple types of tetracarboxylic dianhydride residues X, multiple types of dicarboxylic acid residues Z, or multiple types of tricarboxylic acid anhydride residues W.

[0026] As will be described in detail later, polyamideimides are generally obtained by synthesizing polyamic acids using diamines, tetracarboxylic dianhydrides, and polybasic acid derivatives such as dicarboxylic dichlorides and tricarboxylic anhydride chlorides as monomers, followed by cyclodehydration of the amic acids at the bond between the tetracarboxylic or tricarboxylic acid and the diamine. Polybasic acid derivatives such as dicarboxylic dichlorides and tricarboxylic anhydride chlorides are used as starting monomers, and the resulting polyamideimides have Structure Z (dicarboxylic acid residue) obtained by removing two carboxy groups from a dicarboxylic acid or Structure W obtained by removing three carboxy groups from a tricarboxylic acid. Regardless of the type of starting material (monomer) used in polyamideimide synthesis, the structure corresponding to the tetracarboxylic dianhydride residue X contained in the polyamideimide is referred to as the "tetracarboxylic dianhydride component," the structure corresponding to the diamine residue Y is referred to as the "diamine component," and the structures corresponding to the dicarboxylic acid residue Z and the tricarboxylic anhydride residue W are referred to as the "polybasic acid component."

[0027] The diamine component, tetracarboxylic dianhydride component, and polybasic acid component as monomer units constituting polyamideimide will be described below with examples.

[0028] <Diamine> (Diamine having a fluorene structure) The polyamideimide according to an embodiment of the present invention contains a diamine having a fluorene structure as a diamine component. The diamine having a fluorene structure is a compound having a fluorene structure between two amino groups. Specific examples of the diamine having a fluorene structure include diamines represented by the following group (A).

[0029]

[0030] (A) R in group １ａ , R １ｂ , R ２ａ , R ２ｂ , R ５ａ and R ５ｂare each independently an arbitrary substituent, and from the viewpoint of the solubility of the polyamideimide, are preferably an alkyl group having 1 to 10 carbon atoms, a phenyl group, an alkoxy group, or a halogen. m1, m2, n1, n2, k1, and k2 are each independently an integer of 0 to 4.

[0031] R ３ａ and R ３ｂ is an alkylene group, and R ３ａ and R ３ｂ may be the same or different. p1 and p2 each independently represent 0 or 1. R ６ represents a carbonyl group; q1 and q2 each independently represent 0 or 1.

[0032] Among the (A) group, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 9,9-bis(3-amino-4-hydroxyphenyl)fluorene, 9,9-bis(4-amino-3-hydroxyphenyl)fluorene, and 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene are preferred because they have a small molecular weight, a relatively high proportion of fluorene skeletons, and improve the solubility and transparency of polyamideimide and its compatibility with polyester, and among these, 9,9-bis(4-aminophenyl)fluorene (BAFL) is particularly preferred.

[0033] The amount of the diamine having a fluorene structure relative to the total amount of the diamine components of the polyamideimide is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, particularly preferably 70 mol% or more, and may be 80 mol% or more, 90 mol% or more, or even 100 mol%. The higher the ratio of the diamine having a fluorene structure, the more improved the mechanical strength of the polyamideimide and its compatibility with polyesters may be.

[0034] (Other Diamines) Polyamideimide may contain, as a diamine component, a diamine that does not have a fluorene structure. From the viewpoint of environmental safety of polyamideimide, -C-CF ３ and -C-CF ２Diamines that do not contain -C- are preferred, and those that do not contain fluorine atoms are particularly preferred. Examples of diamines that do not contain fluorine atoms and can achieve both excellent mechanical strength and transparency include alicyclic diamines, diamines having a sulfone group, diaminodiphenyl ethers, aromatic diamines, and chain aliphatic diamines.

[0035] Examples of the alicyclic diamine include isophoronediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornene, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), adamantane-1,3-diamine, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, and 1,1-bis(4-aminophenyl)cyclohexane.

[0036] When an alicyclic diamine is used in addition to a diamine having a fluorene structure, the amount of the alicyclic diamine relative to the total amount of the diamine components may be 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, 12 mol% or more, or 15 mol% or more, and is preferably 70 mol% or less, more preferably 50 mol% or less, and may be 30 mol% or less, or 20 mol% or less.

[0037] Examples of diamines having a sulfone group include 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone, and 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenyl sulfone. Among these, 3,3'-diaminodiphenyl sulfone (3,3'-DDS) and 4,4'-diaminodiphenyl sulfone (4,4'-DDS) are preferred from the viewpoint of mechanical strength. 3,3'-DDS and 4,4'-DDS may be used in combination.

[0038] When a diamine having a sulfone group is used in addition to a diamine having a fluorene structure, the amount of the diamine having a sulfone group relative to the total amount of the diamine components may be 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, 12 mol% or more, or 15 mol% or more, and from the viewpoint of the solubility of polyamideimide, it is preferably 50 mol% or less, more preferably 30 mol% or less, and may be 20 mol% or less, or 10 mol% or less.

[0039] Examples of diaminodiphenyl ethers include 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl ether. When diaminodiphenyl ether is used in addition to a diamine having a fluorene structure, the amount of diaminodiphenyl ether relative to the total amount of diamine components may be 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, 12 mol% or more, or 15 mol% or more, and from the viewpoint of the solubility of polyamideimide, it is preferably 50 mol% or less, and may be 40 mol% or less, 30 mol% or less, 20 mol% or less, or 10 mol% or less.

[0040] The total amount of the diamine having a fluorene structure, the alicyclic diamine, the diamine having a sulfone group, and the diaminodiphenyl ether relative to the total amount of the diamine components of the polyamideimide is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and may be 95 mol% or more, 99 mol% or more, or even 100 mol%.

[0041] Examples of aromatic diamines other than those mentioned above include 2,2'-dimethylbenzidine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, p-xylenediamine, m-xylenediamine, o-xylenediamine, 3,3'-diaminobenzanilide, 3,4'-diaminobenzanilide, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, and 4,4'-diaminodiphenyl. Sulfide, 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, 1,2-di(4-aminophenyl)ethane, 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 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]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, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3 6,6'-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, etc.

[0042] Examples of the chain aliphatic diamine include 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, thiazolinone ... Examples of suitable alkyl siloxanes include polyethylene 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, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, and α,ω-bis(4-aminobutyl)polydimethylsiloxane.

[0043] From the viewpoint of environmental safety of the polyamideimide, the amount of fluorine atom-containing diamine relative to the total amount of diamine components of the polyamideimide is preferably 10 mol % or less, more preferably 5 mol % or less, even more preferably 1 mol % or less, and may be 0.5 mol % or less or 0.1 mol % or less. The polyamideimide may not contain a fluorine atom-containing diamine as a diamine component.

[0044] Among fluorine atom-containing diamines, the structure in which a trifluoromethyl group is bonded to a carbon atom (—C—CF ３ ) and / or a structure in which carbon atoms are bonded to both ends of a difluoromethylene group (—C—CF ２In order to improve the transparency and solubility in solvents of polyamideimides, general soluble polyamideimides contain CF4 as a diamine component on the carbon atom of the aromatic ring. ３ - or -C(CF ３ ) ２ Although it contains diamines having a structure in which - is directly bonded (for example, trifluoromethyl-substituted benzidines such as 2,2'-bis(trifluoromethyl)benzidine, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane), from the viewpoint of environmental safety of polyamideimides, it is preferable that these diamines are not substantially contained. ３ - or -C(CF ３ ) ２ The amount of diamine to which - is directly bonded is preferably less than 0.5 mol %, and may be 0.3 mol % or less, 0.1 mol % or less, or 0.05 mol % or less, or may be 0.

[0045] <Tetracarboxylic acid dianhydride> (Specific acid dianhydride) The polyamideimide according to an embodiment of the present invention contains, as an acid dianhydride component, one or more tetracarboxylic acid dianhydrides selected from the group consisting of bisphenol-type tetracarboxylic acid dianhydrides, bis(trimellitic anhydride) esters, and tetracarboxylic acid dianhydrides having a fluorene structure. Hereinafter, these tetracarboxylic acid dianhydrides will be referred to as "specific acid dianhydrides."

[0046] The bisphenol tetracarboxylic dianhydride is a compound represented by the following general formula (1), and can be obtained, for example, by reacting two hydroxy groups of a bisphenol with iodoisobenzofuran-1,3-dione or the like.

[0047]

[0048] In general formula (1), A is any divalent organic group, and at both ends of A, a phenyl group is bonded to a carbon atom of A. p is 1 or 2. １ａ , R１ｂ , R ２ａ and R ２ｂ are each independently an arbitrary substituent, and from the viewpoint of the solubility of the polyamideimide, are preferably an alkyl group having 1 to 10 carbon atoms, a phenyl group, an alkoxy group, or a halogen. m1 and m2 are each independently an integer of 0 to 3, and n1 and n2 are each independently an integer of 0 to 4.

[0049] Examples of the divalent organic group A include the following (a), (b), and (c). ３ａ and R ３ｂ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. ４ is an alkyl group having 1 to 10 carbon atoms, and k is an integer of 0 to 10. When k is 2 or more, multiple R ４ may be the same or different.

[0050]

[0051] From the viewpoint of the solubility of polyamideimide, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA) is particularly preferred as the bisphenol tetracarboxylic dianhydride.

[0052] The bis(trimellitic anhydride) ester is represented by the following general formula (2).

[0053]

[0054] In general formula (2), B is any divalent organic group, and at both ends of B, a carboxy group is bonded to a carbon atom of B. Specific examples of the divalent organic group B include the following (i) to (x):

[0055]

[0056] The groups represented by formulas (i) to (x) are groups obtained by removing two hydroxyl groups from a diol. For example, the group represented by formula (i) is a group obtained by removing two hydroxyl groups from a hydroquinone derivative which may have a substituent on the benzene ring.

[0057] In formulas (i) and (ii), R １ , R２ａ and R ２ｂ are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a halogen atom, and m, n1, and n2 are each independently an integer of 0 to 4. In formulas (iii) to (vii), R ３ａ , R ３ｂ , R ５ａ , R ５ｂ , R ６ａ and R ６ｂ are each independently an arbitrary substituent, and from the viewpoint of the solubility of the polyamideimide, an alkyl group having 1 to 10 carbon atoms, a phenyl group, an alkoxy group, or a halogen is preferred. k1, k2, i1, and i2 are each independently an integer of 0 to 4, and h1 and h2 are each independently an integer of 0 to 4. In formula (iii), R ４ represents an alkyl group, an alkoxy group or a halogen atom, and j represents an integer of 0 to 10. In formula (viii), p represents an integer of 1 to 10.

[0058] The bis(trimellitic anhydride) ester is preferably an aromatic ester, and among the above (i) to (x), (i) to (vii) are preferred as B in the general formula (2), and among these, (i) to (vi) are preferred, with (i) and (ii) being particularly preferred.

[0059] When B is a group represented by general formula (i), from the viewpoint of the mechanical properties of the resin composition, the bis(trimellitic anhydride) ester of general formula (2) is preferably 1,4-phenylenebis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) (TMHQ) represented by the following formula (2-1):

[0060]

[0061] When B is a group represented by formula (ii), from the viewpoint of the solubility of the polyamideimide, the bis(trimellitic anhydride) ester of general formula (2) is preferably 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) (TAHMBP) represented by the following formula (2-2):

[0062]

[0063] When B is a group represented by formula (iii), from the viewpoint of the solubility of the polyamideimide, the bis(trimellitic anhydride) ester of general formula (2) is preferably bisphenol Z bis(trimellitic anhydride) (BPZ-TME) represented by the following formula (2-3):

[0064]

[0065] When B is a group represented by formula (iv), from the viewpoint of the solubility of the polyamideimide, the bis(trimellitic anhydride) ester of general formula (2) is preferably 5,5'-[cyclododecylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) (TBIS-DMPN) represented by the following formula (2-4):

[0066]

[0067] When B is a group represented by formula (v), from the viewpoint of the solubility of the polyamideimide, the bis(trimellitic anhydride) ester of general formula (2) is preferably 5,5'-[9H-fluoren-9-ylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) (TBIS-MPN) represented by the following formula (2-5):

[0068]

[0069] When B is a group represented by formula (vi), from the viewpoint of the solubility of the polyamideimide, the bis(trimellitic anhydride) ester of general formula (2) is preferably 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) (TBIS-RXN) represented by the following formula (2-6):

[0070]

[0071] A tetracarboxylic acid dianhydride having a fluorene structure is a compound having a fluorene structure between two acid anhydride groups. However, when the bisphenol-type tetracarboxylic acid dianhydride of the above general formula (1) has a fluorene structure, the acid dianhydride is treated as a bisphenol-type tetracarboxylic acid dianhydride. Similarly, when the bis(trimellitic anhydride) ester of the above general formula (2) has a fluorene structure, the acid dianhydride is treated as a bis(trimellitic anhydride) ester.

[0072] Examples of tetracarboxylic dianhydrides having a fluorene structure include the acid dianhydrides represented by the following group (B) and N,N'-(9H-fluoren-9-ylidene-di-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxamide].

[0073]

[0074] (B) R in group １ａ , R １ｂ , R ２ａ , R ２ｂ , R ３ａ , R ３ｂ , R ４ａ and R ４ｂ are each independently an arbitrary substituent, and from the viewpoint of the solubility of the polyamideimide, an alkyl group having 1 to 10 carbon atoms, a phenyl group, an alkoxy group, or a halogen is preferred. m1 and m2 are each independently an integer of 0 to 3. n1 and n2 are each independently an integer of 0 to 4. k1 and k2 are each independently an integer of 0 to 2. j1 and j2 are each independently an integer of 0 to 4.

[0075] R ５ａ and R ５ｂ is an alkylene group, and R ５ａ and R ５ｂ may be the same or different. p1 and p2 each independently represent 0 or 1. R ６ represents a carbonyl group; q1 and q2 each independently represent 0 or 1.

[0076] Among the (B) group, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, and spiro[11H-difuro[3,4-b:3',4'-i]xanthene-11,9'-fluorene]-1,3,7,9-tetraone are preferred as tetracarboxylic acid dianhydrides having a fluorene structure, because they have a small molecular weight, a relatively high proportion of fluorene structures, and can improve the solubility and transparency of polyamideimide and compatibility with polyester.

[0077] Polyamideimides containing the above-described diamine having a fluorene structure as the diamine component and the specific acid dianhydride as the acid dianhydride component tend to exhibit solubility in organic solvents, as well as have high transparency and compatibility with polyesters.

[0078] Among specific acid dianhydrides, from the viewpoints of solubility in organic solvents, transparency, and compatibility with polyesters, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), 1,4-phenylenebis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) (TMHQ), 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) (TAHMBP), bisphenol Z bis(trimellitic anhydride) (BPZ-TME), 5,5'-[cyclododecylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) (TBIS-DMPN), 5,5'-[9H-fluoren-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) Preferred are 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (TBIS-RXN), 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (BPF-PA), and spiro[11H-difuro[3,4-b:3',4'-i]xanthene-11,9'-fluorene]-1,3,7,9-tetraone (SFDA).

[0079] From the viewpoint of UV resistance of polyamideimide, among the specific acid dianhydrides, bisphenol-type tetracarboxylic dianhydrides and acid dianhydrides having a fluorene structure (excluding those having an ester structure) are preferred. These acid dianhydrides do not have an ester bond and do not undergo Friess transition due to UV light, so polyamideimide is less likely to become discolored when exposed to UV light. From the viewpoint of compatibility between polyamideimide and polyester, bisphenol-type tetracarboxylic dianhydrides and bis(trimellitic anhydride) esters are preferred. Bisphenol-type tetracarboxylic dianhydrides are preferred because they have excellent UV resistance and compatibility with polyester, and among them, BPADA is particularly preferred.

[0080] From the viewpoint of the solubility of the polyamideimide in organic solvents and the compatibility with polyesters, the total amount of the specific acid dianhydride relative to the total amount of the acid dianhydride components is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, particularly preferably 70 mol% or more, and may be 80 mol% or more, 90 mol% or more, 95 mol% or more, or 100 mol%. The total amount of the specific acid dianhydride relative to the total amount of the acid dianhydride components 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.

[0081] (Tetracarboxylic acid dianhydride other than specific acid dianhydride) Polyamideimide may contain an acid dianhydride other than the specific acid dianhydride as an acid dianhydride component. ３ and -C-CF ２ Those which do not contain -C- are preferred, and those which do not contain a fluorine atom are particularly preferred. Examples of such acid dianhydrides include alicyclic tetracarboxylic acid dianhydrides, aromatic tetracarboxylic acid dianhydrides, and chain aliphatic tetracarboxylic acid dianhydrides.

[0082] The alicyclic tetracarboxylic dianhydride may 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 polycyclic or may have a spiro structure. Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,1'-bicyclohexane-3,3',4,4'tetracarboxylic acid-3,4:3',4', 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 acid dianhydride, 2,2'-binorbornane-5,5',6,6'-tetracarboxylic acid 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 acid dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)- 1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 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 1,3,6,7-tetracarboxylic dianhydride, tricyclo[6.4.0.0(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-tetraone, ethylene glycol bis(hydrogenated trimellitic anhydride) ester, decahydro[2]benzopyrano[6,5,4,-def][2]benzopyran-1,3,6,8-tetraone, and the like.The inclusion of an alicyclic tetracarboxylic dianhydride as an acid dianhydride component in addition to a specific acid dianhydride tends to improve the mechanical strength of the polyamideimide. In addition, the inclusion of an alicyclic tetracarboxylic dianhydride as an acid dianhydride component in the polyamideimide may improve the compatibility between the polyamideimide and polyester.

[0083] Among the alicyclic tetracarboxylic dianhydrides, from the viewpoint of the transparency and mechanical strength of the polyamideimide, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA), and 1,1'-bicyclohexane-3,3',4,4'tetracarboxylic-3,4:3',4'-dianhydride (H-BPDA) are preferred.

[0084] When an alicyclic tetracarboxylic dianhydride is used in addition to the specific acid dianhydride, the amount of the alicyclic tetracarboxylic dianhydride relative to the total amount of the acid dianhydride components may be 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, 12 mol% or more, or 15 mol% or more. The greater the amount of the alicyclic tetracarboxylic dianhydride, the higher the transparency tends to be. From the viewpoint of ensuring the solubility of the polyamideimide in organic solvents, the amount of the alicyclic tetracarboxylic dianhydride relative to the total amount of the acid dianhydride components is preferably 50 mol% or less, more preferably 40 mol% or less, and may be 30 mol% or less, or 20 mol% or less.

[0085] Examples of aromatic tetracarboxylic dianhydrides other than the specific acid dianhydrides include pyromellitic dianhydride, mellophanic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,4'-oxydiphthalic anhydride (3,4'-ODPA), 4,4'-oxydiphthalic anhydride (4, 4'-ODPA), 3,3'-oxydiphthalic anhydride (3,3'-ODPA), 5,5'-dimethylmethylenebis(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, 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic dianhydride, 4-( 2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)methane dianhydride

[0044] Examples of the dianhydride include 4,4'-bis(3,4-dicarboxybenzoyl)benzene dianhydride, 1,4-bis(3,4-dicarboxybenzoyl)benzene dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)benzophenone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracenetetracarboxylic acid dianhydride, and 1,2,7,8-phenanthrenetetracarboxylic acid dianhydride.

[0086] Among these aromatic tetracarboxylic acid dianhydrides, 3,4'-oxydiphthalic anhydride and 4,4'-oxydiphthalic anhydride are preferred from the viewpoint of the solubility of polyamideimide, and pyromellitic dianhydride and mellophanic dianhydride are preferred from the viewpoint of mechanical strength, with pyromellitic dianhydride being particularly preferred.

[0087] When an aromatic tetracarboxylic dianhydride other than the specific acid dianhydride is used in addition to the specific acid dianhydride, the amount of the aromatic tetracarboxylic dianhydride other than the specific acid dianhydride relative to the total amount of the acid dianhydride components may be 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, 12 mol% or more, or 15 mol% or more. From the viewpoint of ensuring the solubility of the polyamideimide in organic solvents, the amount of the aromatic tetracarboxylic dianhydride other than the specific acid dianhydride relative to the total amount of the acid dianhydride components is preferably 50 mol% or less, more preferably 40 mol% or less, and may be 30 mol% or less or 20 mol% or less.

[0088] Examples of the chain aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, 1,2,3,4-butane tetracarboxylic dianhydride, and meso-butane-1,2,3,4-tetracarboxylic dianhydride.

[0089] From the viewpoint of environmental safety of the polyamideimide, the amount of the fluorine atom-containing acid dianhydride relative to the total amount of the acid dianhydride components of the polyamideimide is preferably 10 mol % or less, more preferably 5 mol % or less, even more preferably 1 mol % or less, and may be 0.5 mol % or less or 0.1 mol % or less. The polyamideimide may not contain a fluorine atom-containing acid dianhydride as an acid dianhydride component.

[0090] Among fluorine atom-containing acid dianhydrides, the structure in which a trifluoromethyl group is bonded to a carbon atom (-C-CF ３ ) and / or a structure in which carbon atoms are bonded to both ends of a difluoromethylene group (—C—CF ２ -C-) has low decomposition properties and is a concern for environmental safety. ３ - or -C(CF３ ) ２ Acid dianhydrides having a structure in which - is directly bonded (for example, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 9,9-bis(trifluoromethyl)xanthenetetracarboxylic dianhydride, 9-trifluoromethylxanthenetetracarboxylic dianhydride, 2,2'-bis(trifluoromethyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride) are poorly degradable in the environment, and therefore, from the viewpoint of environmental safety of polyamideimides, it is preferable that these acid dianhydrides are substantially not contained. ３ - or -C(CF ３ ) ２ The amount of acid dianhydride to which - is directly bonded is preferably less than 0.5 mol %, and may be 0.3 mol % or less, 0.1 mol % or less, or 0.05 mol % or less, or may be 0.

[0091] <Polybasic Acid> As described above, by using a dicarboxylic acid and / or a tricarboxylic acid anhydride as a polybasic acid component in addition to a diamine and a tetracarboxylic acid dianhydride, a polyamideimide containing a dicarboxylic acid-derived structure represented by general formula (VIa) and / or a tricarboxylic acid anhydride-derived structure represented by general formula (VIIa) can be obtained.

[0092] Examples of dicarboxylic acids include aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and 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, 4,4'-biphenyldicarboxylic acid, and 2-fluoroterephthalic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-hexahydroterephthalic acid, hexahydroisophthalic acid, 1,3-cyclopentanedicarboxylic acid, and bi(cyclohexyl)-4,4'-dicarboxylic acid; and heterocyclic dicarboxylic acids such as 2,5-thiophenedicarboxylic acid and 2,5-furandicarboxylic acid.

[0093] Examples of tricarboxylic acid anhydrides include trimellitic anhydride and its derivatives.

[0094] From the viewpoint of the solubility of the polyamideimide, the polybasic acid is preferably an aromatic dicarboxylic acid, an alicyclic dicarboxylic acid, or trimellitic anhydride, with an aromatic dicarboxylic acid being particularly preferred. Among the aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, 4,4'-biphenyldicarboxylic acid, and 4,4'-oxybisbenzoic acid are preferred, with terephthalic acid and isophthalic acid being particularly preferred, and terephthalic acid being particularly preferred. Among the alicyclic dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid and bi(cyclohexyl)-4,4'-dicarboxylic acid are preferred, with 1,4-cyclohexanedicarboxylic acid being particularly preferred.

[0095] The total amount of terephthalic acid, isophthalic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-oxybisbenzoic acid, 1,4-cyclohexanedicarboxylic acid bi(cyclohexyl)-4,4'-dicarboxylic acid, and trimellitic anhydride relative to the total amount of polybasic acid components of the polyamideimide is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, and may be 75 mol% or more, 80 mol% or more, 85 mol% or more, 90 mol% or more, or 95 mol% or more. The total amount of terephthalic acid and isophthalic acid relative to the total amount of polybasic acid components of the polyamideimide may be 50 mol% or more, 60 mol% or more, 70 mol% or more, 75 mol% or more, 80 mol% or more, 85 mol% or more, 90 mol% or more, or 95 mol% or more, and the amount of terephthalic acid may be within this range.

[0096] From the viewpoint of environmental safety of the polyamideimide, the amount of the fluorine atom-containing polybasic acid relative to the total amount of the acid dianhydride components of the polyamideimide is preferably 10 mol % or less, more preferably 5 mol % or less, even more preferably 1 mol % or less, and may be 0.5 mol % or less or 0.1 mol % or less. The polyamideimide may not contain a fluorine atom-containing polybasic acid as an acid dianhydride component.

[0097] Among fluorine atom-containing polybasic acids, those with CF on the carbon atom of the aromatic ring ３- or -C(CF ３ ) ２ Since those having a structure in which - is directly bonded have low decomposability and concern about environmental safety, it is preferable that the polyamideimide does not substantially contain these polybasic acids. ３ - or -C(CF ３ ) ２ The amount of polybasic acids directly bonded with - is preferably less than 0.5 mol %, and may be 0.3 mol % or less, 0.1 mol % or less, or 0.05 mol % or less, or may be 0.

[0098] In the preparation of polyamideimide and polyamic acid as its precursor, polybasic acid derivatives such as dicarboxylic acid dichlorides, dicarboxylic acid esters, dicarboxylic acid anhydrides, and tricarboxylic acid anhydride chlorides may be used in place of the polybasic acid.

[0099] <Ratio of Amide Structures in Polyamideimide> The polyamideimide preferably contains 90 to 110 molar parts of the tetracarboxylic dianhydride-derived structure represented by general formula (IVa), the dicarboxylic acid-derived structure represented by general formula (VIa), and the tricarboxylic anhydride-derived structure represented by general formula (VIIa) relative to 100 molar parts of the diamine-derived structure represented by general formula (Va). The total of the structures of general formulas (IVa), (VIa), and (VIIa) may be 93 to 107 molar parts, 95 to 105 molar parts, 97 to 103 molar parts, or 99 to 101 molar parts relative to 100 molar parts of the structure of general formula (Va).

[0100] The ratio of the total of the structures of general formula (VIa) and general formula (VIIa) to the total of the structures of general formula (IVa), (VIa), and (VIIa) is 1 to 99 mol %. The ratio of the structures of general formula (IVa) to the structures of general formula (VIa) is approximately equal to the ratio of the imide structures of general formula (I) to the amide structures of general formula (II), and the ratio of the structures of general formula (IVa) to the structures of general formula (VIIa) is approximately equal to the ratio of the imide structures of general formula (I) to the amide-imide structures of general formula (III). The ratio of the total of the structure of general formula (VIa) and the structure of general formula (VIIa) to the total of the structure of general formula (IVa), the structure of general formula (VIa), and the structure of general formula (VIIa) may be 5 mol% or more, 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, or 50 mol% or more, and may be 80 mol% or less, 75 mol% or less, 70 mol% or less, 65 mol% or less, or 60 mol% or less.

[0101] The higher the ratio of the structures of general formulae (VIa) and (VIIa), that is, the higher the ratio of the amide structure, the more improved the solubility of the polyamideimide in organic solvents may be.

[0102] The amount of polybasic acid relative to the diamine component of the polyamideimide used in this embodiment, i.e., the total ratio of the structural units of general formulae (VI) and (VII) to the structural unit of general formula (V), may be 5 mol% or more, 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, or 50 mol% or more, and may be 80 mol% or less, 75 mol% or less, 70 mol% or less, 65 mol% or less, or 60 mol% or less.

[0103] <Content of specific fluorine structure in polyamideimide> As described above, a polyamideimide containing a diamine having a fluorene structure as the diamine component and a specific acid dianhydride as the acid dianhydride component exhibits solubility in organic solvents and compatibility with polyesters without substantially containing a fluorine atom-containing monomer.

[0104] In order to reduce the environmental persistence of fluorine-containing compounds, it is preferable that the polyamideimide contains a small amount of monomers (diamines, acid dianhydrides, and polybasic acids) having a specific fluorine structure. The specific fluorine structure is a trifluoromethyl group (CF ３ -), excluding those containing only the components of the following structural formula (i), and a difluoromethylene group (-CF ２ -), excluding those having only the components of the following structural formula (ii): CF ３ -X (i) X-CF ２ -X' (ii)

[0105] X in formula (i) and (ii) is —OR or —NRR′, and X′ in formula (ii) is —H, —CH ３ , aromatic, —C(O)—, —OR″, —SR″, and NR″R′″. R, R′, R″, and R′″ each independently represent —H, —CH ３ , -CH ２ -, aromatic, or -C(O)-.

[0106] From the viewpoint of improving environmental degradability, the amount of fluorine atoms contained in the specific fluorine structure per 1 kg of polyamideimide is preferably less than 500 mg, more preferably less than 300 mg, even more preferably less than 100 mg, and particularly preferably less than 50 mg. In order to achieve excellent environmental degradability, the amount of fluorine atoms per 1 kg of polyamideimide is preferably within the above range.

[0107] <Preparation of Polyamideimide> The method for preparing polyamideimide is not particularly limited. In general, a polyamide acid is prepared as a polyamideimide precursor by reacting a diamine with a tetracarboxylic dianhydride and a polybasic acid or its derivative, and the polyamide acid is then cyclized (imidized) to obtain polyamideimide. The method for preparing polyamide acid is not particularly limited, and any known method can be used. For example, a polyamide acid solution can be obtained by dissolving the total of the acid dianhydride and the polybasic acid or its derivative in approximately equimolar amounts to the diamine (molar ratio of 90:100 to 110:100) in an organic solvent and stirring the mixture.

[0108] 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.

[0109] In the polymerization of polyamic acid, a method of adding an acid dianhydride to a diamine is preferred to suppress ring-opening of the acid dianhydride. When adding multiple types of diamines or multiple types of acid dianhydrides, they may be added all at once or in multiple portions. The physical properties of the polyamideimide can also be controlled by adjusting the order of addition of the monomers.

[0110] The organic solvent used in the polymerization of polyamic acid is not particularly limited, as long as it does not react with diamines, acid dianhydrides, and polybasic acids or their derivatives 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 tetramethyl sulfone; amide-based 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 dichloromethane; aromatic hydrocarbon 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 typically used alone or in combination as needed. From the viewpoint of the solubility and polymerization reactivity of polyamic acid, DMAc, DMF, NMP, etc. are preferably used.

[0111] Polyamideimide is obtained by dehydration cyclization of polyamic acid. One method for preparing polyamideimide from a polyamic acid solution involves adding a dehydrating agent, an imidization catalyst, etc. to the polyamic acid solution and allowing imidization to proceed in the solution. The polyamic acid solution may be heated to accelerate the imidization process. By mixing a solution containing polyamideimide produced by imidization of polyamic acid with a poor solvent, a polyamideimide resin precipitates as a solid. Isolating the polyamideimide resin as a solid allows impurities generated during polyamic acid synthesis, residual dehydrating agents, imidization catalysts, etc., to be washed and removed with the poor solvent, preventing discoloration of the polyamideimide and increased yellowness. Furthermore, isolating the polyamideimide resin as a solid allows the use of solvents suitable for film formation, such as low-boiling point solvents, when preparing a solution for film production.

[0112] The molecular weight of the polyamideimide (weight average molecular weight in terms of polystyrene measured by gel permeation 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 small, the strength of the film may be insufficient. If the molecular weight is too large, the solubility of the polyamideimide and its compatibility with polyester may be poor.

[0113] The polyamideimide is preferably soluble in an organic solvent. Specifically, the polyamideimide is preferably soluble in dimethylformamide (DMF) at 23°C at a concentration of 1% by weight or more. In addition to being soluble in amide solvents such as DMF, the polyamideimide is preferably soluble in non-amide solvents. Examples of non-amide solvents include ketone solvents such as acetone and methyl ethyl ketone, alkyl halide solvents such as chloroform and dichloromethane, and ester solvents such as ethyl acetate and γ-butyrolactone. Non-amide solvents have a lower boiling point than amide solvents, making it easier to remove residual solvent during film production. Therefore, polyamideimides soluble in non-amide solvents are expected to improve film productivity. It is particularly preferable that the polyamideimide is soluble in dichloromethane.

[0114] [Polyester] The polyester is a condensate of a dicarboxylic acid and a glycol, and has a structure derived from a dicarboxylic acid and a structure derived from a diol. From the viewpoint of ensuring the mechanical strength of a molded article such as a film formed from the resin composition, a polyester having a weight average molecular weight (Mw, polystyrene equivalent) of more than 10,000 is used. The weight average molecular weight of the polyester is preferably 15,000 or more, more preferably 20,000 or more, and may be 30,000 or more. From the viewpoint of ensuring compatibility with polyamideimide and moldability of the resin composition into a film or the like, the weight average molecular weight of the polyester is preferably 200,000 or less, more preferably 150,000 or less, even more preferably 100,000 or less, and may be 80,000 or less.

[0115] Polyethylene terephthalate (PET), a typical polyester, is a condensation product of ethylene glycol and terephthalic acid, and has high crystallinity and low solubility in organic solvents. In this embodiment, a polyester soluble in organic solvents is used. The polyester is preferably soluble in organic solvents common to polyamideimides, and is particularly preferably soluble in highly polar solvents such as amide-based solvents.

[0116] The polyester may have a weight average molecular weight of more than 10,000 and be soluble in an organic solvent, and the dicarboxylic acid component and the diol component are not particularly limited. From the viewpoint of solubility in an organic solvent, amorphous polyesters are preferred.

[0117] <Diol> From the viewpoint of imparting solubility to the polyester in organic solvents, the diol component of the polyester is preferably a diol having a chain alkylene group having 3 or more carbon atoms which may be branched, a diol having a chain alkenylene group having 3 or more carbon atoms which may be branched, a polyalkylene glycol, or a diol having a cyclic structure. Hereinafter, these diols will be referred to as "specific diols."

[0118] Examples of diols having a chain alkylene structure of 3 or more carbon atoms which may have a branch include propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, etc. Among these, diols having a chain alkylene structure of 5 or more carbon atoms are preferred, and diols having an alkylene group with a branched structure such as neopentyl glycol are particularly preferred. Examples of diols having a chain alkenylene group of 3 or more carbon atoms which may have a branch include 2-butene-1,4-diol, etc.

[0119] Examples of polyalkylene glycols include diethylene glycol, triethylene glycol, dipropylene glycol, and polytetramethylene ether glycol.

[0120] Examples of diols having a cyclic structure include diols having a cycloalkylene structure such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol; diols having a cyclic ether structure such as isosorbide; diols having a fluorene structure; and diols having a bisphenol derivative structure.

[0121] Among these, butanediol, neopentyl glycol, polytetramethylene ether glycol, diols having a fluorene structure, and diols having a bisphenol derivative structure are preferred from the viewpoint of the solubility of polyester and compatibility with polyamideimide.

[0122] The diol having a fluorene structure has a fluorene skeleton between two hydroxy groups and is represented by the following general formula (3).

[0123]

[0124] In general formula (3), Ar1 and Ar2 are aromatic hydrocarbon rings. １ａ and R １ｂ are each independently an alkyl group having 1 to 10 carbon atoms or a phenyl group, and n1 and n2 are each independently an integer of 0 or more. ２ａ and R ２ｂ are each independently an alkyl group having 1 to 10 carbon atoms or a phenyl group, and n1 and n2 are each independently an integer of 0 to 4. ３ａ and R ３ｂ is an alkylene group, and R ５ａ and R ５ｂ may be the same or different. p1 and p2 each independently represent an integer of 0 or more. q1 and q2 are 1.

[0125] Specific examples of the diol represented by general formula (3) include 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, 9,9-bis[4-(2-hydroxypropoxy)phenyl]fluorene, 9,9-bis[4-[2-(2-hydroxyethoxy)ethoxy]phenyl]-9H-fluorene, 2,2'-[(9H-fluorene-9,9-diyl)bis(naphthalene-6,2-diyloxy)]diethanol, 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene, 9,9-bis[4-(2-hydroxypropoxy)-3-phenylphenyl]fluorene, and 9,9-bis{4-[2-(2-hydroxyethoxy)ethoxy]-3-phenylphenyl}fluorene. Among these, from the viewpoint of improving heat resistance, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, 9,9-bis[4-(2-hydroxypropoxy)phenyl]fluorene, and 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene are preferred.

[0126] The diol having bisphenol derivative structure is the one in which alkylene oxide is added to two phenolic hydroxyl groups of bisphenol (bisphenol alkylene oxide adduct), and preferably the ethylene oxide (EO) adduct and propylene oxide (PO) adduct of bisphenol.In addition, the diol having fluorene structure of the above general formula (3) includes the diol having bisphenol derivative structure, but the diol having fluorene skeleton is treated as the diol having fluorene structure even if it has bisphenol derivative structure.

[0127] Examples of bisphenols without a fluorene skeleton include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP), 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), bis(4-hydroxyphenyl)diphenylmethane (bisphenol BP), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C), 1,1-bis(4-hydroxyphenyl)ethane (bisphenol E), bis(4-hydroxyphenyl)methane (bisphenol F), and 2,2-bis(4-hydroxy-3-isopropyl bisphenol G), 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol M), bis(4-hydroxyphenyl)sulfone (bisphenol S), 1,4-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol P), 5,5'-(1-methylethylidene)-bis[1,1'(bisphenyl)-2-ol]propane (bisphenol PH), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC), 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), and the like.

[0128] Among the bisphenol alkylene oxide adducts, from the viewpoint of solubility in polyester, ethylene oxide adducts of bisphenol A, ethylene oxide adducts of bisphenol S, and ethylene oxide adducts of bisphenol Z are preferred.

[0129] The polyester may contain a diol other than the above-mentioned specific diol as a diol component. An example of a diol other than the specific diol is ethylene glycol. When the specific diol and ethylene glycol are used in combination, from the viewpoint of compatibility between the polyester and polyamideimide, the molar ratio of the specific diol to ethylene glycol is preferably 90:10 to 10:90, and may be 80:20 to 20:80, or 60:40 to 40:60. In other words, the amount of the specific diol relative to the total amount of the diol component is preferably 10 mol% or more, and may be 20 mol% or more, or 40 mol% or more.

[0130] <Dicarboxylic Acid> The dicarboxylic acid component of the polyester is not particularly limited, and various aromatic dicarboxylic acids and aliphatic dicarboxylic acids can be used. As the dicarboxylic acid, an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid can be used in combination.

[0131] Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and biphenyldicarboxylic acid.Further examples of aromatic dicarboxylic acids include dicarboxylic acids having a fluorene structure, such as 9,9-bis(carboxymethyl)fluorene and 9,9-bis(2-carboxyethyl)fluorene.

[0132] From the viewpoint of improving the solubility and mechanical strength of the polyester, terephthalic acid and isophthalic acid are preferred. Terephthalic acid and isophthalic acid may be used alone or in combination. When terephthalic acid and isophthalic acid are used in combination, from the viewpoint of the solubility of the polyester, the molar ratio of terephthalic acid to isophthalic acid is preferably 90:10 to 10:90, and may be 25:75 to 75:25 or 60:40 to 40:60. From the viewpoint of the solubility and mechanical strength of the polyester, the total amount of terephthalic acid and isophthalic acid relative to the total amount of dicarboxylic acid components of the polyester is preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 60 mol% or more, and may be 80 mol% or more.

[0133] Examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and tetrahydrophthalic acid.

[0134] Inclusion of an aliphatic dicarboxylic acid as the dicarboxylic acid component of the polyester may improve the compatibility between the polyester and polyamideimide. From the viewpoint of improving compatibility with polyamideimide, the aliphatic dicarboxylic acid is preferably a dicarboxylic acid having 6 to 12 carbon atoms, particularly 6 to 10 carbon atoms, and among these, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid are preferred because they can also contribute to improving the solubility of the polyester.

[0135] <Other Components> Monomers other than diols and dicarboxylic acids may be used as monomer components constituting the polyester, as long as the effects of the present invention are not impaired. Examples of monomers other than diols and dicarboxylic acids include polyols having three or more hydroxy groups (e.g., trimethylolpropane, glycerin), monoalcohols (e.g., octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, 2-phenoxyethanol), polycarboxylic acids having three or more carboxy groups (e.g., 1,3,4-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, pyromellitic acid, trimellitic acid, tetrahydrophthalic acid), monocarboxylic acids (e.g., lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexanoic acid), and hydroxycarboxylic acids (e.g., methyl methyl esters). Examples of such an acid include compounds having one or more hydroxy groups and / or one or more carboxy groups, such as lactic acid, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxyvaleric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, 10-hydroxystearic acid, 4-hydroxyphenylstearic acid, and 4-(β-hydroxy)ethoxybenzoic acid), lactones (e.g., β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone), and oxiranes (e.g., ethylene oxide), as well as compounds that generate one or more hydroxy groups and / or one or more carboxy groups upon hydrolysis.

[0136] <Preparation of Polyester> The polymerization method for the polyester is not particularly limited, and various known methods can be used, such as a method in which an oligomer is obtained by a transesterification method or a direct esterification method, and then melt polymerization or solid-phase polymerization is performed. In the polymerization of the polyester, a dicarboxylic acid derivative such as an acid anhydride may be used as the dicarboxylic acid component.

[0137] From the viewpoint of the heat resistance and moldability of the resin composition and the molded article, the glass transition temperature (Tg) of the polyester is preferably −25 to 200° C., more preferably 15 to 180° C., still more preferably 40 to 150° C., and may be about 60 to 130° C.

[0138] Commercially available polyester resins may be used as the polyester. Examples of commercially available polyester resins containing a diol having a fluorene structure as a diol component include OKP4HT (manufactured by Osaka Gas Chemicals, Mw: 38,000, Tg: 142°C) and OKP4 (manufactured by Osaka Gas Chemicals, Mw: 40,000, Tg: 121°C). Examples of commercially available polyester resins containing a diol having a bisphenol derivative structure as a diol component include Elitel UE3600 (manufactured by Unitika, Mw: 60,000, Tg: 75°C), Elitel UE3690 (manufactured by Unitika, Mw: 46,000, Tg: 90°C), Elitel UE9100 (manufactured by Unitika, Mw: 77,000, Tg: 19°C), and Vylon 290 (manufactured by Toyobo, Mw: 61,000, Tg: 72°C).

[0139] Examples of commercially available polyester resins containing specific diols other than those mentioned above as diol components include Elitel UE3200G (manufactured by Unitika, Mw: 43,000, Tg: 65°C), Elitel UE3210 (manufactured by Unitika, Mw: 62,000, Tg: 45°C), Elitel UE3240 (manufactured by Unitika, Mw: 50,000, Tg: 40°C), Elitel UE3500 (manufactured by Unitika, Mw: 83,000, Tg: 15°C), Elitel UE3 510 (manufactured by Unitika, Mw: 63,000, Tg: -25°C), Elitel UE9200 (manufactured by Unitika, Mw: 39,000, Tg: 65°C), Elitel UE9800 (manufactured by Unitika, Mw: 40,000, Tg: 85°C), Vylon 200 (manufactured by Toyobo, Mw: 42,000, Tg: 67°C), Vylon 240 (manufactured by Toyobo, Mw: 35,000, Tg: 60°C), and Vylon 600 (manufactured by Toyobo, Mw: 38,000, Tg: 47°C).

[0140] [Preparation of Resin Composition] The polyamideimide and polyester are mixed to prepare a resin composition. Polyamideimides generally do not exhibit compatibility with other polymers, but as described above, polyamideimides containing specific diamines as diamine components exhibit compatibility with solvent-soluble polyesters.

[0141] Whether a specific polyamideimide and a specific polyester are compatible with each other is confirmed by preparing a 10 μm thick film containing the polyamideimide and the polyester. If the film is transparent and has a haze of 10% or less, the polyamideimide and the polyester are judged to be compatible with each other, and if the film's haze exceeds 10%, the polyamideimide and the polyester are judged to be incompatible with each other.

[0142] The ratio of polyamideimide to polyester in the resin composition is not particularly limited. The composition ratio (weight ratio) of polyamideimide to polyester may be 2:98 to 98:2, 10:90 to 90:10, 25:75 to 75:25, or 40:60 to 60:40. The higher the ratio of polyamideimide, the higher the mechanical strength of molded articles such as films tends to be. The higher the ratio of polyester, the less coloring and the higher the transparency of molded articles such as films tends to be.

[0143] In order to fully exert the effect of improving transparency by mixing polyamideimide and polyester, the ratio of polyester to the total of polyamideimide and polyester 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.

[0144] The resin composition may be a simple mixture of a polyamideimide resin precipitated as a solid content and a polyester resin, or may be a mixture of a polyamideimide resin and a polyester resin. Furthermore, when a polyamideimide solution is mixed with a poor solvent to precipitate a polyamideimide resin, a polyester resin may be mixed with the solution, and a resin composition obtained by mixing polyamideimide and polyester may be precipitated as a solid (powder).

[0145] The resin composition may be a mixed solution containing polyamideimide and polyester. The method for mixing the resins is not particularly limited, and the resins may be mixed in a solid state or in a liquid state to form a mixed solution. A polyamideimide solution and a polyester solution may be prepared separately, and then the two may be mixed to prepare a mixed solution of polyamideimide and polyester.

[0146] The solvent for the solution containing polyamideimide and polyester is not particularly limited as long as it can dissolve both polyamideimide and polyester. 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 methylcyclohexanone, and alkyl halide solvents such as chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, dichlorobenzene, and dichloromethane.

[0147] Generally, polyamideimides have low solubility in solvents and are often soluble only in highly polar solvents. Therefore, from the viewpoints of the solubility of polyamideimides and the compatibility of polyamideimides with polyesters in solution, amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone are preferred, while from the viewpoint of the removability of the solvent when producing a molded product such as a film, low-boiling non-amide solvents are preferred. Ketone solvents and alkyl halide solvents are preferred because they have excellent solubility in both polyamideimides and polyesters, have low boiling points, and allow easy removal of residual solvent when producing a film.

[0148] The resin composition may contain organic or inorganic low molecular weight compounds, polymeric compounds (e.g., epoxy resins), etc. The resin composition may contain flame retardants, ultraviolet absorbers, crosslinking agents, dyes, pigments, surfactants, leveling agents, plasticizers, fine particles, sensitizers, etc. The fine particles 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 includes carbon fiber, glass fiber, aramid fiber, etc.

[0149] [Molded Articles and Films] The above-mentioned compositions can be used to form various molded articles. Molding methods include melt methods such as injection molding, transfer molding, press molding, blow molding, inflation molding, calendar molding, and melt extrusion molding. Resin compositions containing polyamideimide and polyester tend to have lower melt viscosity than polyamideimide alone, and are excellent in moldability in injection molding, transfer molding, press molding, melt extrusion molding, and the like.

[0150] Furthermore, a solution of a resin composition containing polyamideimide and polyester tends to have a lower solution viscosity than a solution of polyamideimide alone at the same solid content concentration, which is advantageous in terms of ease of handling during transportation and the like, high coatability, and reduction of unevenness in film thickness.

[0151] In one embodiment, the molded article is a film. The film molding method may be either a melting method or a solution method, but the solution method is preferred from the viewpoint of producing a film excellent in transparency and uniformity. In the solution method, a solution containing the above-mentioned polyamideimide and polyester is applied to a support, and the solvent is dried and removed to obtain a film.

[0152] The resin solution can be applied to a support by a known method using a bar coater, a comma coater, or the like. The support may be a glass substrate, a metal substrate such as SUS, a metal drum, a metal belt, a plastic film, or the like. From the viewpoint of improving productivity, it is preferable to use an endless support such as a metal drum or a metal belt, or a long plastic film as the support and produce the film by a roll-to-roll method. When using a plastic film as the support, it is sufficient to appropriately select a material that is insoluble in the solvent of the film-forming dope.

[0153] It is preferable to heat the film when drying the solvent. The heating temperature is not particularly limited as long as it can remove the solvent and can suppress coloration of the resulting film, and is appropriately set between room temperature and about 250°C, with 50°C to 220°C being preferred. The heating temperature may be increased in stages. In order to increase the efficiency of solvent removal, the resin film may be peeled off from the support and dried after drying has progressed to a certain extent. Heating may be performed under reduced pressure to promote solvent removal.

[0154] A resin composition containing polyamideimide and polyester has a lower glass transition temperature than polyamideimide alone because the polyamideimide and polyester are compatible with each other, making it possible to mold and process the resin at low temperatures and reducing the discoloration of molded products such as films.

[0155] The film may be stretched in one or more directions for the purpose of improving the mechanical strength of the film. Stretching the film orients the polymer chains in the stretching direction, improving the strength of the film in the in-plane direction and tending to suppress the occurrence of breakage or cracking in the film. In a compatible system of polyamideimide and polyester, the tensile modulus in the stretching direction tends to increase, and as a result, the flex resistance tends to improve.

[0156] For example, films used as cover films or substrate materials for foldable displays are repeatedly folded along the folding axis at the same location, and therefore are required to have high mechanical strength in a direction perpendicular to the folding axis. Therefore, by arranging the film so that the stretching direction is perpendicular to the folding axis, even when the film is repeatedly folded, breakage or cracking of the film at the folding location is unlikely to occur, and a device with high bending resistance can be provided.

[0157] The film stretching conditions are not particularly limited. As the stretching method, free-end stretching, fixed-end stretching, free-end shrinkage, fixed-end shrinkage, etc. can be applied. From the viewpoint of orienting the molecules of the film in one direction, free-end stretching, typified by a method in which the film being transported is stretched in the transport direction by the difference in peripheral speed between nip rolls before and after the film (so-called longitudinal stretching), or fixed-end stretching, typified by a method in which the film being transported is stretched in a direction perpendicular to the transport direction using a tenter clip device (so-called transverse stretching), is preferred.

[0158] The film may be biaxially stretched to increase the strength in any in-plane direction. 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 perpendicular direction may be the same or different. When a difference in stretching ratio is made, the mechanical strength in the direction with the larger stretching ratio tends to be relatively larger. When a biaxially stretched film with anisotropic stretching ratio is used in a foldable device, it is preferable to arrange it so that the direction with the larger stretching ratio is perpendicular to the folding axis.

[0159] The stretching temperature is about ±40°C of the glass transition temperature of the film, and may be about 120 to 300°C, 150 to 250°C, or 180 to 230°C. The stretching ratio is about 1 to 200%, and may be 5 to 150%, 10 to 120%, or 20 to 100%. The higher the stretching ratio, the higher the tensile modulus in the stretching direction tends to be. On the other hand, if the stretching ratio is excessively high, the mechanical strength in the direction perpendicular to the stretching direction tends to decrease, and the handleability of the film may be reduced.

[0160] The thickness of the film is not particularly limited and may be appropriately set depending on the application. The film thickness is, for example, 5 to 300 μm. From the viewpoint of obtaining a film that is both self-supporting and flexible and has high transparency, the film thickness is preferably 10 μm to 200 μm, and may be 30 μm to 150 μm, 40 μm to 100 μm, or 50 μm to 80 μm. The thickness of a film used as a cover film for a display is preferably 10 μm or more. When the film is stretched, the thickness after stretching is preferably within the above range.

[0161] The haze of the film is preferably 5% or less, more preferably 4% or less, and may be 3.5% or less, 3% or less, 2% or less, or 1% or less. As described above, since polyamideimide and polyester are compatible with each other, a film with low haze and high transparency can be obtained. The resin composition obtained by mixing polyamideimide and polyester preferably has a haze of 5% or less when a film with a thickness of 30 μm is produced.

[0162] The total light transmittance of the film is preferably 85% or more, more preferably 86% or more, even more preferably 87% or more, particularly preferably 88% or more, and may be 89% or more or 90% or more. The resin composition obtained by mixing polyamideimide and polyester preferably has a total light transmittance of 85% or more when formed into a film having a thickness of 30 μm.

[0163] The yellowness index (YI) of the film is not particularly limited, but is preferably 20.0 or less, more preferably 10.0 or less, even more preferably 5.0 or less, and may be 4.0 or less, 3.0 or less, 2.0 or less, 1.0 or less, or 0.0 or less. The resin composition obtained by mixing polyamideimide and polyester preferably has a yellowness index of 20.0 or less when a film having a thickness of 30 μm is produced. As described above, by mixing polyamideimide and polyester, a film with less coloration and a small YI can be obtained compared to when polyamideimide is used alone.

[0164] The tensile modulus of the film is not particularly limited, but from the viewpoint of strength, the tensile modulus of the film at room temperature is preferably 2.0 GPa or more, more preferably 3.0 GPa or more, and even more preferably 4.0 GPa or more. The tensile modulus may be anisotropic, and the tensile modulus in at least one direction may be 4.0 GPa or more, 5.0 GPa or more, 5.5 GPa or more, 6.0 GPa or more, 6.5 GPa or more, or 7.0 GPa or more.

[0165] The film may have an anisotropic in-plane tensile modulus. As described above, the anisotropy of the tensile modulus can be imparted by stretching the film. The difference between the modulus of elasticity in the direction (first direction) in which the tensile modulus is greatest in the film plane and the tensile modulus in the direction (second direction) perpendicular to the first direction in the film plane may be 5% or more. When the difference between the tensile modulus of elasticity in the first direction and the tensile modulus of elasticity in the second direction is large, the orientation of the polymer chains may improve mechanical properties such as bending resistance and pencil hardness.

[0166] The pencil hardness of the film is preferably 6B or higher, more preferably 4B or higher, and may be 2B or higher, F or higher, or 2H or higher. In a compatible system of polyamideimide and polyester, the pencil hardness is unlikely to decrease even if the proportion of polyester is increased. Therefore, a film with little coloration and excellent transparency can be provided without significantly reducing the excellent mechanical strength specific to polyamideimide.

[0167] The in-plane birefringence ΔN of the film is preferably less than 0.020, more preferably less than 0.015, even more preferably less than 0.010, and particularly preferably less than 0.006. The birefringence ΔP through the thickness of the film is preferably less than 0.020, more preferably less than 0.015, even more preferably less than 0.010, and particularly preferably less than 0.006.

[0168] The in-plane birefringence ΔN is the refractive index n in the direction in which the in-plane refractive index is maximum (the slow axis direction). ｘ and the refractive index n in the direction perpendicular to the slow axis in the plane (the fast axis direction) ｙThe in-plane birefringence ΔN is multiplied by the film thickness to give the in-plane retardation of the film. The birefringence ΔP in the thickness direction is calculated by multiplying the refractive index n ｘ and the refractive index in the fast axis direction n ｙ and the refractive index in the thickness direction n ｚ Difference from: (n ｘ +n ｙ ) / 2-n ｚ The thickness retardation of the film is calculated by multiplying the birefringence ΔN in the thickness direction by the thickness of the film. The smaller the birefringence ΔN and ΔP of the film, the higher the visibility when applied to a display.

[0169] Films formed from resin compositions containing polyamideimide and polyester are suitable for use as display materials because they exhibit little coloration and high transparency. In particular, films with high mechanical strength can be applied to surface components such as display cover windows. Films formed from the resin compositions containing polyamideimide and polyester exhibit little birefringence even after stretching, so they can achieve both high strength and low birefringence while maintaining high transparency. When used in practice, the film of the present invention may be provided on its surface with an antistatic layer, an easy-adhesion layer, a hard coat layer, an antireflection layer, or the like.

[0170] The following examples will be used to further explain the present invention, but the present invention is not limited to these examples.

[0171] [Preparation of Polyamide-imide Resin] <Preparation of Polyamic Acid> Dimethylformamide (DMF) was placed in a separable flask and stirred under a nitrogen atmosphere. The diamine, tetracarboxylic dianhydride, and polybasic acid derivative were added in the ratios (mol %) shown in Table 1, and acetic acid was then added. The mixture was stirred under a nitrogen atmosphere for 5 to 10 hours to react, yielding a polyamic acid solution with a solids concentration of 13 wt %.

[0172] <Imidization and isolation of polyamide-imide resin> Pyridine was added to the polyamic acid solution and completely dispersed, followed by the addition of acetic anhydride and stirring at 90°C for 3 hours to carry out imidization. The solution after imidization was cooled to room temperature, and then 2-propyl alcohol (IPA) was added dropwise while stirring the solution to precipitate a polyamide-imide resin. Further IPA was added, and after stirring for about 30 minutes, the solution was subjected to suction filtration using a Kiriyama funnel. The obtained solid was washed with IPA and then dried for 12 hours in a vacuum oven set at 120°C to obtain a polyamide-imide resin.

[0173] [Preparation of Resin Composition (Solution) and Film Fabrication] <Reference Example: Fabrication of Polyamideimide Film> The polyamideimide resin obtained above was dissolved in DMF to prepare a polyamideimide solution with a solids concentration of 10 wt %. The polyamideimide solution was applied to an alkali-free glass plate and heated and dried in air at 60°C, 90°C, 120°C, 150°C, 180°C, and 200°C in that order for 15 minutes at each temperature to produce films of Reference Examples 1, 3, and 4 shown in Table 2.

[0174] Examples and Comparative Examples: Preparation of Resin Compositions of Polyamideimide (PAI) and Polyester (PEs) and Fabrication of Films Polyamideimide resins Nos. 1 to 15 in Table 1 and the following commercially available polyester resins were dissolved in DMF in a weight ratio of 1:1 to prepare resin solutions with a solid content of 10% by weight.

[0175] PEs1: Eliter UE9200 (polyester containing neopentyl glycol as a diol component; manufactured by Unitika; weight average molecular weight: 39,000, glass transition temperature: 65°C) PEs2: Eliter UE3600 (polyester containing a bisphenol alkylene oxide adduct as a diol component; manufactured by Unitika; weight average molecular weight: 60,000, glass transition temperature: 75°C) PEs3: OKP4HT (polyester containing a diol having a fluorene structure as a diol component; manufactured by Osaka Gas Chemicals; weight average molecular weight: 38,000, glass transition temperature: 142°C)

[0176] The weight-average molecular weight of the polyester resin was measured using a gel permeation chromatography (HLC-8220GPC equivalent) manufactured by Tosoh Corporation under the following conditions: Eluent: LiBr (30 mM) + H3PO4 (30 mM) DMF solution Sample concentration: 0.15 wt% Flow rate: 0.6 mL / min Column configuration: From upstream, TSK guard column Super AW-H, TSK gel AWM-H, TSK gel AWM-H Column temperature: 40°C Detection conditions: RI, UV Molecular weight standard: Polystyrene (manufactured by Tosoh Corporation)

[0177] The resin solution was applied to an alkali-free glass plate and heated and dried in the air for 15 minutes at each temperature in the order of 60°C, 90°C, 120°C, 150°C, 180°C, and 200°C to produce the films shown in Table 2. In Comparative Examples 15-1 and 15-2, cloudiness of the film was confirmed visually, and therefore the following evaluations were not performed.

[0178] [Measurement of Haze, Total Light Transmittance, and Yellowness Index] The films of the Reference Examples and Examples were cut into 3 cm squares to prepare measurement samples. Haze and total light transmittance (TT) were measured using a haze meter "HZ-V3" manufactured by Suga Test Instruments in accordance with JIS K7136 and JIS K7361-1, and yellowness index (YI) was measured using a spectrophotometer "SC-P" manufactured by Suga Test Instruments in accordance with JIS K7373.

[0179] [Evaluation Results] The compositions of the polyamideimides are shown in Table 1. The types and amounts of polyamideimide resins and polyester resins, the types of solvents, as well as the film thickness, haze, total light transmittance, and yellowness index in the Reference Examples, Examples, and Comparative Examples are shown in Table 2. In Tables 1 and 2 and Table 3 described below, the compounds are described by the following abbreviations.

[0180] <Diamines> BAFL: 9,9-bis(4-aminophenyl)fluorene 3,3'-DDS: 3,3'-diaminodiphenyl sulfone 3,4'-ODA: 3,4'-diaminodiphenyl ether 4,4'-ODA: 4,4'-diaminodiphenyl ether TFMB: 2,2'-bis(trifluoromethyl)benzidine

[0181] <Tetracarboxylic acid dianhydrides> BPAF: 9,9-bis(3,4-dicarboxyphenyl)fluorene anhydride BPF-PA: 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride BPADA: 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride TAHMBP: 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) TMHQ: 1,4-phenylenebis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate) TBIS-RXN: 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) TBIS-MPN: 5,5'-(9H-fluoren-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate] TBIS-DMPN: 5,5'-[cyclododecylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride 4,4'-ODPA: 4,4'-oxydiphthalic anhydride BT-100: 1,2,3,4-butanetetracarboxylic dianhydride PMDA: pyromellitic dianhydride

[0182]

[0183]

[0184] It was found that polyamideimides Nos. 1 to 14, which contain BPAF, a diamine having a fluorene structure, as the diamine component and a specific acid dianhydride as the acid dianhydride component, are soluble in organic solvents and compatible with polyester resins, and can form transparent films having a haze of 5% or less and a total light transmittance (TT) of 80% or more.

[0185] A comparison of Reference Example 1 and Example 1-1 shows that by mixing polyamideimide and polyester, a film with improved transparency and higher total light transmittance and lower yellowness can be obtained compared to a film made of polyamideimide alone. A similar trend was observed in a comparison of Reference Example 3 and Examples 3-1 to 3-3, and a comparison of Reference Example 4 and Examples 4-1 to 4-3, etc. These results show that by employing a compatible system of polyamideimide and polyester, a film with higher total light transmittance and superior transparency can be obtained compared to a film made of polyamideimide alone.

[0186] [Preparation of Stretched Films] In the same manner as in the above Examples, films were prepared from mixed solutions of polyamideimide resin and polyester resin, and fixed-end stretching was performed at the stretching temperatures and stretch ratios listed in Table 3 to obtain the stretched films of Examples 51 to 54. A polyimide film was prepared using a polyimide resin containing TFMB as the diamine component and BPADA as the acid dianhydride component (Reference Example 56). A film was prepared using a polyimide having the same composition as Reference Example 56, and fixed-end stretching was performed under the conditions listed in Table 3 to obtain the stretched film of Comparative Example 55.

[0187] [Evaluation] <Glass transition temperature> A strip-shaped test piece measuring 25 mm in length and 5 mm in width was cut out from the unstretched film, and dynamic viscoelasticity measurement was performed using a dynamic viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM) in tension mode, with an initial chuck distance of 15 mm, a frequency of 10 Hz, and a heating rate of 10°C / min, while the temperature was raised from 30°C to 300°C, to measure the loss tangent tanδ. When tanδ was plotted against temperature, the temperature at which tanδ showed a maximum value was taken as the glass transition temperature (Tg).

[0188] <Tensile modulus> The film was cut into a 10 mm wide strip with the long side in the stretching direction (first direction), and after standing at 23°C / 55% RH for 1 day to condition the humidity, a tensile test was performed using an "AUTOGRAPH AGS-X" manufactured by Shimadzu Corporation under the following conditions, with the stretching direction as the tensile direction, to measure the tensile modulus in the first direction. Using a sample cut into a strip with the long side in the direction perpendicular to the stretching direction (second direction), a tensile test was performed with the second direction as the tensile direction, and the tensile modulus in the second direction was also measured. Grip distance: 100 mm, Pulling speed: 20.0 mm / min, Measurement temperature: 23°C

[0189] <Birefringence> The front retardation R0 and thickness retardation Rth were measured using a phase difference measurement device KOBRA manufactured by Oji Scientific Instruments. The thickness retardation was calculated using the program attached to the device from the retardation value measured at an inclination angle of 40°, the R0 value, the film thickness, and the average refractive index measured by the prism coupler method. The front retardation R0 and thickness retardation Rth were divided by the film thickness, respectively, to obtain the birefringence ΔN and ΔP.

[0190] Table 3 shows the type and amount of polyamideimide (or polyimide) resin, polyester resin, type of solvent, film thickness, glass transition temperature, and film evaluation results.

[0191]

[0192] The polyimide film of Comparative Example 55 (Reference Example 56) had a small front birefringence ΔN of 0.0003 before stretching, but ΔN increased significantly after stretching. Furthermore, the polyimide film of Comparative Example 55 had a large thickness direction birefringence ΔP before stretching, and ΔP increased further after stretching.

[0193] On the other hand, the films of Examples 51 to 54 containing polyamideimide and polyester were stretched to achieve an in-plane tensile modulus difference of 5% or more, but the stretched films had low birefringence, with in-plane birefringence ΔN and thickness direction birefringence ΔP both less than 0.02. Furthermore, the films of the examples maintained high transparency (low haze and high light transmittance) even after stretching.

[0194] These results show that a film containing polyamideimide and polyester can be stretched to increase the tensile modulus in the stretching direction and improve the mechanical strength while maintaining high transparency and low birefringence.

Claims

1. A resin composition comprising a polyamideimide and a polyester, the polyester having a weight average molecular weight of more than 10,000, the polyamideimide having a structure derived from a diamine, a structure derived from a tetracarboxylic dianhydride and a structure derived from a polybasic acid, the diamine comprising a diamine having a fluorene structure, and the tetracarboxylic dianhydride comprising at least one selected from the group consisting of a tetracarboxylic dianhydride represented by general formula (1), a tetracarboxylic dianhydride represented by general formula (2) and a tetracarboxylic dianhydride having a fluorene structure: In the general formula (1), A is any divalent organic group, and at both ends of A, a phenyl group is bonded to a carbon atom of A, p is 1 or 2, and R １ａ , R １ｂ , R ２ａ and R ２ｂ are each independently any substituent, m1 and m2 are each independently an integer of 0 to 3, and n1 and n2 are each independently an integer of 0 to 4, and in general formula (2), B is any divalent organic group, and at both ends of B, a carboxy group and a carbon atom of B are bonded to each other.

2. The resin composition according to claim 1, wherein the polyamideimide has a ratio of a structure derived from a diamine having a fluorene structure of 50 mol % or more based on the total amount of structures derived from diamine.

3. The resin composition according to claim 1, wherein the polyamideimide has a total of a structure derived from the tetracarboxylic dianhydride represented by general formula (1), a structure derived from the tetracarboxylic dianhydride represented by general formula (2), and a structure derived from the tetracarboxylic dianhydride having a fluorene structure, which is 50 mol % or more relative to the total amount of structures derived from tetracarboxylic acid.

4. The resin composition according to claim 1, wherein the diamine having a fluorene structure is 9,9-bis(4-aminophenyl)fluorene.

5. The one or more tetracarboxylic dianhydrides selected from the group consisting of tetracarboxylic dianhydrides represented by the general formula (1), tetracarboxylic dianhydrides represented by the general formula (2), and tetracarboxylic dianhydrides having a fluorene structure are 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 1,4-phenylenebis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate), 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diylbis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate), bisphenol Z bis(trimellitic anhydride), 5,5'-[cyclododecylidenebis(2-methyl-4,1-phenylene)]bis(1,3-dihydro-1,3-dioxo-5 ... isobenzofuran carboxylate), 5,5'-spiro [9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis (1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate), 5,5'-[9H-fluoren-9-ylidenebis (2-methyl-4,1-phenylene)] bis (1,3-dihydro-1,3-dioxo-5-isobenzofuran carboxylate), 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride, 9,9-bis [4- (3,4-dicarboxyphenoxy) phenyl] fluorene dianhydride, and spiro [11H-difuro [3,4-b: 3', 4'-i] xanthene-11,9'-fluorene] -1,3,7,9-tetraone, the resin composition according to claim 1.

6. The resin composition according to claim 1, wherein the polyamide-imide has a ratio of fluorine atom-containing diamine-derived structures to the total amount of diamine-derived structures of less than 10 mol%, a ratio of fluorine atom-containing tetracarboxylic acid dianhydride-derived structures to the total amount of tetracarboxylic acid dianhydride-derived structures of less than 10 mol%, and a ratio of fluorine atom-containing polybasic acid-derived structures to the total amount of polybasic acid-derived structures of less than 10 mol%.

7. The resin composition according to claim 1, wherein the polyester has a structure derived from a dicarboxylic acid and a structure derived from a diol, and the diol comprises at least one selected from the group consisting of a diol having a chain alkylene group having 3 or more carbon atoms which may be branched, a diol having a chain alkenylene group having 3 or more carbon atoms which may be branched, a polyalkylene glycol, and a diol having a cyclic structure.

8. The resin composition according to claim 1, wherein the polyester has a structure derived from a dicarboxylic acid and a structure derived from a diol, and the diol includes at least one selected from the group consisting of a diol having a fluorene structure and a diol having a bisphenol derivative structure.

9. The resin composition according to claim 1, wherein the polyester has a structure derived from a dicarboxylic acid and a structure derived from a diol, and the diol contains a bisphenol alkylene oxide adduct.

10. The resin composition according to claim 1, comprising said polyamideimide and said polyester in a weight ratio ranging from 2:98 to 98:

2.

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

12. A film comprising the resin composition according to any one of claims 1 to 10.

13. The film of claim 12, which is a stretched film stretched in at least one direction.

14. The film according to claim 12, wherein the in-plane birefringence ΔN and the thickness direction birefringence ΔP are both less than 0.

02.

15. The film of claim 12, wherein the difference between the tensile modulus in a first direction in the plane of the film, in which the modulus is greatest, and the tensile modulus in a second direction in the plane of the film perpendicular to the first direction is 5% or more.

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