Polyamide-imide, resin composition, molded article, and film

Abstract

The present invention pertains to: a polyamide-imide; and a resin composition comprising said polyamide-imide and another resin. This polyamide-imide includes, as a diamine component, a diamine having a difluoromethoxy group, and includes, as a tetracarboxylic dianhydride component, at least one tetracarboxylic dianhydride selected from the group consisting of tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(trimellitic anhydride)esters. Examples of said other resin forming the resin composition include acrylic resins and polyester resins.

Description

Polyamideimide, resin composition, molded article and film

[0001] The present invention relates to a polyamideimide, a resin composition containing the polyamideimide, and a molded article such as 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] A method for producing a highly transparent polyamideimide film has been proposed that uses a polyamideimide that is soluble in organic solvents and does not require high-temperature imidization after film formation. Such soluble polyamideimides use fluorine-containing compounds as the diamine and / or tetracarboxylic dianhydride monomers to balance transparency and mechanical properties. For example, the polyamideimide disclosed in Patent Document 1 uses 2,2'-bis(trifluoromethyl)benzidine (TFMB) as the diamine and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) as the tetracarboxylic dianhydride.

[0004] Patent Document 2 describes that the transparency and other properties of the film can be improved by mixing a soluble polyamideimide with another resin.

[0005] International Publication No. WO 2013 / 048126 International Publication No. WO 2023 / 132310

[0006] 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, an object of the present invention is to provide a polyamideimide that is environmentally safe, soluble in organic solvents, and highly transparent, as well as a resin composition containing the polyamideimide, and a molded article such as a film.

[0008] The present invention relates to a polyamideimide and a resin composition containing the polyamideimide and another resin. The polyamideimide contains, as a diamine component, a diamine (specific diamine) having a difluoromethoxy group, and, as a tetracarboxylic dianhydride component, one or more tetracarboxylic dianhydrides (specific acid dianhydrides) selected from the group consisting of tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(trimellitic anhydride) esters.

[0009] Preferred examples of diamines having a difluoromethoxy group include 2,2'-bis(difluoromethoxy)benzidine, 3,3'-bis(difluoromethoxy)benzidine, and 2,3'-bis(difluoromethoxy)benzidine.

[0010] Preferred examples of the specific acid dianhydride include 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 5,5'-(9H-fluoren-9-ylidenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate], 5,5'-spiro[9H-fluorene-9,9'-[9 H[xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate, spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride, p-phenylenebis(trimellitic acid monoester anhydride), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'diyl, and bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'diyl.

[0011] The polyamideimide may contain a diamine other than the specific diamine as the diamine component, and may contain a tetracarboxylic acid dianhydride other than the specific acid dianhydride as the tetracarboxylic acid dianhydride component.

[0012] Examples of tetracarboxylic dianhydrides other than the specific acid dianhydrides include 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3',-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0013] Polyamideimide is a compound in which the carbon atoms of the aromatic ring are CF ３ - or -C(CF ３ )２ The amount of diamine having a structure in which - is directly bonded is less than 0.5 mol %, and the amount of CF on the carbon atom of the aromatic ring is less than 0.5 mol % based on the total amount of the tetracarboxylic dianhydride component. ３ - or -C(CF ３ ) ２ The amount of tetracarboxylic acid dianhydride having a structure in which - is directly bonded is less than 0.5 mol %, and the amount of tetracarboxylic acid dianhydride having a structure in which - is directly bonded to the carbon atom of the aromatic ring is less than 0.5 mol % based on the total amount of the polybasic acid component. ３ - or -C(CF ３ ) ２ The amount of polybasic acids having a structure in which - is directly bonded is preferably less than 0.5 mol %.

[0014] The polyamideimide is preferably soluble in dimethylformamide at 23°C.

[0015] The resin composition of the present invention contains the above-described polyamideimide and another resin. Examples of the other resin include an acrylic resin and a polyester resin. The resin composition may contain the polyamideimide and the other resin in a weight ratio ranging from 98:2 to 2:98.

[0016] The polyamideimide and resin composition described above can be applied to molded articles such as films.

[0017] The polyamideimide of the present invention, which contains a specific diamine as a diamine component and a specific acid dianhydride as a tetracarboxylic dianhydride component, has excellent solubility in organic solvents and transparency. Furthermore, since the specific diamine has a lower environmental persistence than organic fluorine compounds such as fluoroalkyl-substituted benzidine, the polyamideimide of the present invention has excellent environmental safety.

[0018] Furthermore, the polyamideimide is compatible with acrylic resins and polyesters. Mixed resin films of polyamideimide and other resins can reduce coloration without significantly reducing the excellent mechanical strength of polyamideimide.

[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> (Specific diamine) The polyamideimide of the present invention contains a diamine component having a difluoromethoxy group (—O—CHF ２ Hereinafter, such diamines may be referred to as "specific diamines."

[0029] Monohydrodifluoromethyl (-CHF) in specific diamines ２ ) is trifluoromethyl (-CHF ３) tend to be more degradable in the environment than carbon atoms bonded to fluorine atoms (-CHF ２ The structure in which a carbon atom to which a fluorine atom is bonded is bonded to a carbon atom (e.g., CF ３ Therefore, polyamideimides containing a specific diamine as a diamine component are expected to have significantly reduced environmental persistence compared to conventional soluble polyamideimides containing an organic fluorine compound such as a fluoroalkyl-substituted benzidine as a diamine component.

[0030] From the viewpoint of reactivity, the specific diamine is preferably one having a structure in which a difluoromethoxy group is bonded to a carbon atom of an aromatic ring, and among these, one having a structure in which a difluoromethoxy group is bonded to a carbon atom of an aromatic ring and having no fluorine atom directly bonded to the aromatic ring to which the difluoromethoxy group is bonded is preferred, and one not containing any fluorine atom other than the difluoromethoxy group is particularly preferred. Examples of the specific diamine in which a difluoromethoxy group is bonded to a carbon atom of an aromatic ring include difluoromethoxy-substituted benzidine and difluoromethoxy-substituted phenylenediamine.

[0031] Examples of difluoromethoxy-substituted benzidines include 2-(difluoromethoxy)benzidine, 3-(difluoromethoxy)benzidine, 2,3-bis(difluoromethoxy)benzidine, 2,5-bis(difluoromethoxy)benzidine, 2,6-bis(difluoromethoxy)benzidine, 2,3,5-tris(difluoromethoxy)benzidine, 2,3,6-tris(difluoromethoxy)benzidine, 2,3,5,6-tetrakis(difluoromethoxy)benzidine, 2,2'-bis(difluoromethoxy)benzidine (DFMOB), 3,3'-bis(difluoromethoxy)benzidine, 2,3'-bis(difluoromethoxy)benzidine, 2,2',3-tris(difluoromethoxy)benzidine, 2,3,3'-tris(difluoromethoxyl)benzidine, 2,2',5-tris(difluoromethoxy)benzidine, 2,2',6-tris(difluoromethoxy)benzidine, 2,3',5-tris(difluoromethoxy)benzidine, 2,3',6-tris(difluoromethoxy)benzidine, 2,2',3,3'-tetrakis(difluoromethoxy)benzidine, 2,2',5,5'-tetrakis(difluoromethoxy)benzidine, and 2,2',6,6'-tetrakis(difluoromethoxy)benzidine.

[0032] Examples of difluoromethoxy-substituted phenylenediamines include 1,2-diamino-4-(difluoromethoxy)benzene, 1,3-diamino-4-(difluoromethoxy)benzene, 1,4-diamino-2-(difluoromethoxy)benzene, 1,4-diamino-2,3-bis(difluoromethoxy)benzene, 1,4-diamino-2,5-bis(difluoromethoxy)benzene, 1,4-diamino-2,6-bis(difluoromethoxy)benzene, 1,4-diamino-2,3,5-tris(difluoromethoxy)benzene, and 1,4-diamino-2,3,5,6-tetrakis(difluoromethoxy)benzene.

[0033] From the viewpoint of the polymerizability and mechanical strength of the polyamideimide, difluoromethoxy-substituted benzidine is preferred as the specific diamine. Among them, from the viewpoint of the solubility of the polyamideimide resin in organic solvents and compatibility with other resins, those having a difluoromethoxy group at the 2- or 3-position of the biphenyl are preferred, with 2,2'-bis(difluoromethoxy)benzidine (hereinafter referred to as "DFMOB"), 3,3'-bis(difluoromethoxy)benzidine, and 2,3'-bis(difluoromethoxy)benzidine being more preferred, and DFMOB being particularly preferred. By having a difluoromethoxy group at the 2- or 3-position of the biphenyl, in addition to a decrease in π electron density due to the electron-withdrawing properties of the difluoromethoxy group, the steric hindrance of the difluoromethoxy group inhibits π-π stacking between benzene rings, thereby shifting the absorption edge wavelength to shorter wavelengths and reducing coloration of the polyamideimide. Furthermore, in the case of DFMOB, the steric hindrance between the difluoromethoxy groups at the 2- and 2'-positions of the biphenyl causes the bond between the two benzene rings of the biphenyl to twist, reducing the planarity of the π-conjugation, thereby shifting the absorption edge wavelength to shorter wavelengths and reducing the coloration of the polyamideimide.

[0034] The amount of the specific diamine relative to the total amount of the diamine components is preferably 10 mol% or more, more preferably 30 mol% or more, even more preferably 50 mol% or more, and may be 60 mol% or more, 70 mol% or more, 80 mol% or more, or 90 mol% or more, or even 100 mol%. Among these, it is particularly preferable that the amount of difluoromethoxy-substituted benzidine is within this range. The higher the ratio of the specific diamine, the more suppressed the coloring and the mechanical strength of the film, such as pencil hardness, elastic modulus, breaking strength, and breaking elongation, may be improved.

[0035] (Diamines other than the specific diamines) The polyamideimide may contain diamines other than the specific diamines as the diamine component. ３ and -C-CF ２ It is preferable that it does not contain —C—. ３ and -C-CF ２Examples of fluorine atom-containing diamines that do not contain —C— include diamines having a structure in which the oxygen atom of a trifluoromethoxy group is bonded to a carbon atom of an aromatic ring, such as 2,2′-bis(trifluoromethoxy)benzidine, 3,3′-bis(trifluoromethoxy)benzidine, and 2,3′-bis(trifluoromethoxy)benzidine.

[0036] Examples of diamines not containing fluorine atoms include 2,2'-dimethylbenzidine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, and 3,4'-diaminodiphenyl sulfone. sulfone, 4,4'-diaminodiphenyl sulfone, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-di(3-amino phenyl)propane, 2,2-di(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 1,1-di(3-aminophenyl)-1-phenylethane, 1,1-di(4-aminophenyl)-1-phenylethane, 1-(3-aminophenyl)-1-(4-aminophenyl)-1-phenylethane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene , 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(3-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl)benzene, 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene, 2,6-bis(3-aminophenoxy)benzonitrile, 2,6-bis(3-aminophenoxy)pyridine, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-amino 2,2-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]benz benzene, 1,4-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 4 ,4'-bis[4-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone, 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenyl sulfone, 3,3'-diamino-4,4'-diphenoxybenzophenone, 3,3 '-Diamino-4,4'-diviphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis(4-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(3-aminobutyl)polydimethylsiloxane, bis(aminomethyl)ether, bis(2-aminoethyl)ether, bis(3-aminopropyl)ether, bis(2-aminomethoxy)ethyl]ether, bis[2-(2-aminoethoxy)ethyl]ether, bis[2-(3-aminoprotoxy)ethyl]ether, 1,2-bis(aminomethoxy)ethane, 1,2-bis(2-aminoethoxy)ethane, 1,2-bis[2-(aminomethoxy)ethoxy]ethane, 1,2-bis[2-(2-aminoethoxy)ethoxy]ethane, ethylene glycol bis(3-aminopropyl)ether, diethylene glycol bis(3-aminopropyl)ether, triethylene glycol bis(3-aminopropyl)ether, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, trans 1,4-diaminocyclohexane, 1,2-di(2-aminoethyl)cyclohexane, 1,3-di(2-aminoethyl)cyclohexane, 1,4-di(2-aminoethyl)cyclohexane, bis(4-aminocyclohexyl)methane, isophoronediamine, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, and the like.

[0037] The use of diaminodiphenyl sulfone as the diamine in addition to the specific diamine may improve the solubility in solvents and transparency of the polyamide-imide resin. Among diaminodiphenyl sulfones, 3,3'-diaminodiphenyl sulfone (3,3'-DDS) and 4,4'-diaminodiphenyl sulfone (4,4'-DDS) are preferred, and these may be used in combination.

[0038] When diaminodiphenyl sulfone is used in addition to the specific diamine, the amount of diaminodiphenyl sulfone relative to the total amount of the diamine components may be 1 to 40 mol %, 3 to 30 mol %, or 5 to 25 mol %.

[0039] The use of a diamine having a cardo structure in addition to a specific diamine as the diamine may improve the solubility in solvents, transparency, and mechanical strength of the polyamide-imide resin. The cardo structure is a structure in which four aromatic rings are bonded to the carbon atom at the 9th position of fluorene. Preferred diamines having a cardo structure are 9,9-bis(4-aminophenyl)fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, and 9,9-bis(4-amino-3-methylphenyl)fluorene, and these may be used in combination.

[0040] When a diamine having a cardo structure is used in addition to the specific diamine, the amount of the diamine having a cardo structure relative to the total amount of the diamine components may be 1 to 80 mol %, 3 to 60 mol %, or 5 to 30 mol %.

[0041] The total amount of the specific diamine, diaminodiphenylsulfone, and diamine having a cardo structure relative to the total amount of diamine components in 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%.

[0042] The polyamideimide may contain a fluorine atom-containing diamine other than the specific diamine as a diamine component, but from the viewpoint of environmental safety of the polyamideimide, the amount of the fluorine atom-containing diamine other than the specific diamine relative to the total amount of the diamine components of the polyamideimide is preferably 30 mol % or less, more preferably 20 mol % or less, even more preferably 10 mol % or less, and may be 5 mol % or less, 1 mol % or less, or 0.5 mol % or less. The polyamideimide may not contain a fluorine atom-containing diamine other than the specific diamine as a diamine component.

[0043] 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 ２ In 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.

[0044] <Tetracarboxylic acid dianhydride> (Specific acid dianhydride) The polyamideimide of the present invention contains, as an acid dianhydride component, one or more acid dianhydrides selected from the group consisting of acid dianhydrides having an ether bond, acid dianhydrides having a cardo structure, and bis(trimellitic anhydride) esters. Hereinafter, these acid dianhydrides will be referred to as "specific acid dianhydrides."

[0045] The use of an acid dianhydride having an ether bond tends to improve the solubility of the polyamideimide resin in a solvent. Examples of acid dianhydrides having an ether bond include 3,4'-oxydiphthalic anhydride (a-ODPA), 4,4'-oxydiphthalic anhydride (s-ODPA), and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA). From the viewpoints of the solubility of the polyamideimide resin and compatibility with other resins, BPADA is particularly preferred.

[0046] Use of an acid dianhydride having a cardo structure tends to improve the solubility in solvents, mechanical properties, and heat resistance of the polyamide-imide resin.

[0047] Acid dianhydrides having a cardo structure include 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (BPF-PA), N,N'-(9H-fluoren-9-ylidene-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxamide] (FDA-ATA), 5,5'-(9H-fluoren-9-ylidenebis(2-methyl) 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate) (TBIS.MPN), 5,5'-spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate (TBIS.RXN), spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride (SFDA), and the like.

[0048] The bis(trimellitic anhydride) ester is represented by the following general formula (1).

[0049]

[0050] X in the general formula (1) is any divalent organic group, and at both ends of X, a carboxy group is bonded to a carbon atom of X. The divalent organic group X is difluoromethylene (-CF ２Specific examples of the divalent organic group X include the following (i) to (viii):

[0051]

[0052] In formulas (i) and (ii), R １ , R ２ａ 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), (iv), and (v), R ３ａ and R ３ｂ 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 or a phenyl group is preferred. k1 and k2 are each independently an integer of 0 to 4. R ４ is an alkyl group, an alkoxy group, or a halogen; and j is an integer of 0 to 10.

[0053] The bis(trimellitic anhydride) ester is preferably an aromatic ester, and among the above (i) to (viii), (i) to (viii) are preferred as X in the general formula (1), with (i) to (iv) being preferred and (i) and (ii) being particularly preferred.

[0054] When X is a group represented by general formula (i), from the viewpoint of the mechanical properties of a molded product such as a film, the bis(trimellitic anhydride) ester of general formula (1) is preferably p-phenylene bis(trimellitic acid monoester acid anhydride) (TMHQ) represented by the following formula (2-1):

[0055]

[0056] When X is a group represented by formula (ii), from the viewpoint of the solubility of the polyamideimide, the bis(trimellitic anhydride) ester of general formula (1) is preferably bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diyl (TAHMBP) represented by the following formula (2-2):

[0057]

[0058] Specific examples of bis(trimellitic anhydride) esters other than those of the above formulas (2-1) and (2-2) include bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'-diyl (BP-TME), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-3,3'-dimethylbiphenyl-4,4'-diyl (OCBP-TME), tert-butylhydroquinone, Examples of suitable bisphenol Z bis(trimellitic anhydride) (TA.BHQ), trimethylhydroquinone bis(trimellitic anhydride) (TA.TMHQ), 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), and the like.

[0059] From the viewpoint of the solubility of polyamideimide, TMHQ and TAHMBP are particularly preferred as the bis(trimellitic anhydride) ester.

[0060] Polyamideimides containing the above-mentioned specific diamine as the diamine component and the specific acid dianhydride as the acid dianhydride component tend to exhibit solubility in organic solvents and have high transparency and mechanical strength.

[0061] Among the specific acid dianhydrides, from the viewpoint of solubility in organic solvents and transparency, 4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), 3,4'-oxydiphthalic anhydride (a-ODPA), 4,4'-oxydiphthalic anhydride (s-ODPA), 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF), 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (BPF-PA), 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[ ... Preferred are fluorene-9,9'-[9H]xanthene]-3',6'-diylbis(1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate (TBIS.RXN), spiro[fluorene-9,9'xanthene]-2',3',6',7'-tetracarboxylic dianhydride (SFDA), p-phenylenebis(trimellitic acid monoester anhydride) (TMHQ), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'diyl (OCBP-TME), and bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'diyl (TAHMBP).

[0062] From the viewpoints of the solubility and UV resistance of polyamideimide, among the specific acid dianhydrides, acid dianhydrides having an ether bond and acid dianhydrides having a cardo structure are preferred, with BPADA, a-ODPA, s-ODPA, BPAF, BPF-PA, and SFDA being particularly preferred.

[0063] From the viewpoint of making the polyamideimide soluble in an organic solvent, the total amount of the specific acid dianhydride relative to the total amount of the acid dianhydride components is preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and may be 30 mol% or more, 35 mol% or more, 40 mol% or more, 45 mol% or more, or 50 mol% or more. The total amount of the specific acid dianhydride relative to the total amount of the acid dianhydride components may be 100 mol%, or may be 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, 75 mol% or less, or 70 mol% or less.

[0064] (Acid dianhydride other than the specific acid dianhydride) Polyamideimide may contain an acid dianhydride other than the specific acid dianhydride as the acid dianhydride component. Examples of such acid dianhydrides include alicyclic tetracarboxylic acid dianhydrides and aromatic tetracarboxylic acid dianhydrides. From the viewpoint of environmental safety of polyamideimide, -C-CF 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.

[0065] 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-dimethylcyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,1'-bicyclohexane-3,3',4,4'tetracarboxylic acid-3,4:3',4'-dianhydride, and 1,1'-bicyclohexane-3,3',4,4'tetracarboxylic acid-3,4:3',4'-dianhydride. hydrate, 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, cyclohexane-1,4-diylbis(methylene)bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylate), 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 5,5'-[cyclohexylidenebis(4,1-phenyleneoxy)]bis-1,3-isobenzofurandione, 5-isobenzofurancarboxylic acid, 1,3-dihydro-1,3-di Oxo-,5,5'-[1,4-cyclohexanediylbis(methylene)]ester, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid 2,3:5,6-dianhydride, decahydro-1,4,5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic dianhydride, tricyclo[6.4.0.0(2,7)]dodecane-1,8:2,Examples of suitable dianhydrides include 7-tetracarboxylic acid 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, etc. By including an alicyclic tetracarboxylic acid dianhydride as the dianhydride component in addition to a specific dianhydride, the mechanical strength of the polyamideimide tends to be improved. Furthermore, by including an alicyclic tetracarboxylic acid dianhydride as the dianhydride component in the polyamideimide, the compatibility of the polyamideimide with other resins may be improved.

[0066] Among alicyclic tetracarboxylic dianhydrides, from the viewpoint of transparency and mechanical strength of polyamideimide, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetracarboxylic dianhydride (P ... Tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA-100), bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BEDA), bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride (BODA), and 1,1'-bicyclohexane-3,3',4,4'tetracarboxylic acid-3,4:3',4'-dianhydride (H-BPDA) are preferred. Among these, from the viewpoint of mechanical strength, tetracarboxylic anhydrides in which two acid anhydride groups are bonded to one alicyclic ring are preferred, and CBDA is particularly preferred.

[0067] 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 mechanical strength 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 80 mol% or less, more preferably 60 mol% or less, even more preferably 50 mol% or less, and may be 40 mol% or less, 30 mol% or less, or 20 mol% or less.

[0068] Examples of aromatic tetracarboxylic dianhydrides other than the specific acid dianhydrides include pyromellitic dianhydride (PMDA), 1,2,3,4-benzenetetracarboxylic dianhydride (MPDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4' 2,3,3',4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), 2,2',3,3',-biphenyltetracarboxylic dianhydride (i-BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), 5,5'-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, and bis(3,4-dicarboxyphenyl)sulfone dianhydride. Among these aromatic tetracarboxylic dianhydrides, a-BPDA, s-BPDA, i-BPDA, PMDA, MPDA, and DSDA are preferred from the viewpoint of improving mechanical strength.

[0069] 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 80 mol% or less, more preferably 60 mol% or less, even more preferably 50 mol% or less, and may be 40 mol% or less, 30 mol% or less, or 20 mol% or less.

[0070] The polyamideimide may contain, as an acid dianhydride component, a chain aliphatic tetracarboxylic dianhydride such as ethylene tetracarboxylic dianhydride, 1,2,3,4-butane tetracarboxylic dianhydride, or meso-butane-1,2,3,4-tetracarboxylic dianhydride.

[0071] The amount of the fluorine atom-containing acid dianhydride relative to the total amount of the acid dianhydride components of the polyamideimide is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and may be 5 mol% or less, 1 mol% or less, or 0.5 mol% or less. The polyamideimide may not contain a fluorine atom-containing acid dianhydride as an acid dianhydride component.

[0072] 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(CF ３ ) ２Acid 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) are poorly degradable in the environment, and therefore, from the viewpoint of environmental safety of polyamideimide, 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.

[0073] (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.

[0074] 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.

[0075] Examples of tricarboxylic acid anhydrides include trimellitic anhydride, 2-fluorotrimellitic anhydride, 5-fluorotrimellitic anhydride, 6-fluorotrimellitic anhydride, 2,5-difluorotrimellitic anhydride, 2,6-difluorotrimellitic anhydride, 5,6-difluorotrimellitic anhydride, and 2,5,6-trifluorotrimellitic anhydride derivatives.

[0076] 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 aromatic dicarboxylic acid and trimellitic anhydride 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.

[0077] From the viewpoint of environmental safety of polyamideimide, polyamideimide is a polybasic acid component containing CF ３ - or -C(CF ３ ) ２ It is preferable that the polyamideimide does not substantially contain a polybasic acid having a structure in which - is directly bonded to a carbon atom of an aromatic ring. 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.

[0078] 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.

[0079] <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).

[0080] 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.

[0081] 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.

[0082] 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.

[0083] <Content of specific fluorine structure in polyamideimide> As described above, polyamideimide containing, as the diamine component, a diamine (specific diamine) having a difluoromethoxy group, and, as the acid dianhydride component, one or more acid dianhydrides (specific acid dianhydrides) selected from the group consisting of acid dianhydrides having an ether bond, acid dianhydrides having a cardo structure, and bis(trimellitic anhydride) esters, has a -C-CF ３ , -C-CF ２ It is substantially free of structures such as —C— and exhibits solubility in organic solvents.

[0084] In order to reduce the environmental persistence of fluorine-containing compounds, it is preferable that the polyamideimide contains a small amount of monomers having a specific fluorine structure. The specific fluorine structure is a monomer having at least one completely fluorinated methyl group (CF ３ -) or methylene (-CF ２ -) A structure containing a carbon atom (not bonded to any of H, Cl, Br, or I) excluding those having only the components of the following structural formula (i) or (ii): CF ３ -X (i) X-CF ２ -X' (ii)

[0085] X in formula (i) and (ii) is —OR or —NRR′, and X′ in formula (II) is —CH ３ , -CH ２ R, R', R'' and R''' are each independently -H, -CH ３ , -CH ２ -, aromatic, or -C(O)-.

[0086] 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.

[0087] <Preparation of Polyamideimide> The method for preparing polyamideimide is not particularly limited. In general, a polyamide acid as a polyamideimide precursor is prepared 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 a polyamideimide. As described above, by adjusting the monomer composition constituting the polyamideimide, i.e., the types and ratios of the acid dianhydride, polybasic acid or its derivative, and diamine, a polyamideimide having solubility in organic solvents and transparency can be obtained.

[0088] The method for preparing polyamic acid is not particularly limited, and any known method can be used. For example, a polyamic acid solution can be obtained by dissolving the acid dianhydride and the polybasic acid or its derivative in an organic solvent in approximately equimolar amounts (molar ratio of 90:100 to 110:100) with the diamine, followed by stirring. The concentration of the polyamic acid solution is typically 5 to 35 wt %, preferably 10 to 30 wt %. A concentration within this range ensures that the polyamic acid obtained by polymerization has an appropriate molecular weight and that the polyamic acid solution has an appropriate viscosity.

[0089] 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, or polybasic acids 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 methylene chloride; 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.

[0090] 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.

[0091] The molecular weight of the polyamideimide (weight average molecular weight in terms of polyethylene oxide 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 resin and its compatibility with other resins may be poor.

[0092] 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.

[0093] [Resin Composition] The polyamideimide of the present invention contains a specific diamine and a specific acid dianhydride, and therefore exhibits solubility in organic solvents and compatibility with other resins. The polyamideimide of the present invention is particularly compatible with acrylic resins and polyesters, and can be used as a resin composition containing the polyamideimide and these resins. Furthermore, the polyamideimide of the present invention can be made into a resin composition by adding various additives.

[0094] <Acrylic Resin> Examples of acrylic resins include poly(meth)acrylic acid esters such as polymethyl methacrylate, methyl methacrylate-(meth)acrylic acid copolymers, methyl methacrylate-(meth)acrylic acid ester copolymers, methyl methacrylate-acrylic acid ester-(meth)acrylic acid copolymers, methyl (meth)acrylate-styrene copolymers, etc. The stereoregularity of the polymer is not particularly limited, and may be any of isotactic, syndiotactic, and atactic.

[0095] From the viewpoints of transparency, compatibility with polyamideimide, and mechanical strength of molded articles such as films, the acrylic resin is preferably one having methyl methacrylate as a main structural unit. The amount of methyl methacrylate relative to the total amount of monomer components in the acrylic resin is preferably 60% by weight or more, and may be 70% by weight or more, 80% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more. The acrylic resin may be a methyl methacrylate homopolymer.

[0096] The acrylic resin may be one into which an imide structure or a lactone ring structure has been introduced. Such modified polymers are preferably those into which an imide structure or a lactone ring structure has been introduced into an acrylic polymer having a methyl methacrylate content within the above range. That is, in the acrylic resin modified by the introduction of an imide structure or a lactone ring structure, the total amount of methyl methacrylate and the modified structure of methyl methacrylate is preferably 60% by weight or more, and may be 70% by weight or more, 80% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more. The modified polymer may be one into which an imide structure or a lactone ring structure has been introduced into a methyl methacrylate homopolymer.

[0097] Introducing an imide structure into an acrylic polymer such as methyl methacrylate tends to increase the glass transition temperature of the acrylic resin. Furthermore, since the acrylic resin contains an imide structure, its compatibility with polyamideimide may be improved. For example, even if a specific polyamideimide resin is not compatible with polymethyl methacrylate, it may be compatible with an acrylic resin having a glutarimide structure.

[0098] Acrylic resins having a glutarimide structure can be obtained by heating and melting polymethyl methacrylate resin and treating it with an imidizing agent, as described in, for example, JP 2010-261025 A. Commercially available imide-modified polymethyl methacrylates, such as "PLEXIMID TT70" and "PLEXIMID 8805" manufactured by EVONIK, can also be used.

[0099] When the acrylic resin has a glutarimide structure, the glutarimide content may be 3% by weight or more, 10% by weight or more, 20% by weight or more, 30% by weight or more, or 50% by weight or more. １ The introduction rate of the glutarimide structure (imidization rate) is determined from the H-NMR spectrum, and the imidization rate is calculated by converting it into weight. For example, in the case of methyl methacrylate into which a glutarimide structure has been introduced, the O—CH ３ The area A of the peak due to protons (around 3.5 to 3.8 ppm) and the N-CH ３ The imidization rate Im=B / (A+B) can be calculated from the area B of the peak due to protons (around 3.0 to 3.3 ppm).

[0100] From the viewpoint of the heat resistance of the resin composition and the molded article, the glass transition temperature of the acrylic resin is preferably 100°C or higher, more preferably 110°C or higher, and may be 115°C or higher or 120°C or higher.

[0101] From the viewpoints of solubility in organic solvents, compatibility with the polyamideimide, and strength of molded articles, the weight-average molecular weight (polystyrene equivalent) of the acrylic resin is preferably 5,000 to 5,000,000, more preferably 10,000 to 2,000,000, and may be 30,000 to 1,000,000 or 50,000 to 500,000. If the molecular weight of the acrylic resin is too small, the durability of the resulting film may be reduced. If the molecular weight of the acrylic resin is too high, film formability may be poor.

[0102] <Polyester> Polyester is a condensation product of dicarboxylic acid and diol, and has a structure derived from dicarboxylic acid and a structure derived from diol. The dicarboxylic acid component and diol component of the polyester are not particularly limited, but from the viewpoint of solubility in organic solvents, they are preferably amorphous. Polyethylene terephthalate (PET), a typical polyester, is a condensation product of ethylene glycol and terephthalic acid, and is highly crystalline and has low solubility in organic solvents, whereas amorphous polyester is soluble in organic solvents and exhibits high compatibility with the above-mentioned polyamideimide.

[0103] (Diol) From the viewpoint of imparting solubility to the polyester in an organic solvent, 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."

[0104] 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.

[0105] Examples of polyalkylene glycols include diethylene glycol, triethylene glycol, dipropylene glycol, and polytetramethylene ether glycol.

[0106] 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 cardo structure; and diols having a bisphenol derivative structure.

[0107] Among these, butanediol, neopentyl glycol, polytetramethylene ether glycol, diols having a cardo structure, and diols having a bisphenol derivative structure are preferred from the viewpoint of the solubility of polyester and compatibility with polyamideimide.

[0108] Specific examples of diols having a cardo structure 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.

[0109] The diol having a bisphenol derivative structure is a diol in which an alkylene oxide is added to two phenolic hydroxy groups of a bisphenol (a bisphenol alkylene oxide adduct), and an ethylene oxide (EO) adduct or a propylene oxide (PO) adduct of a bisphenol is preferred. Note that the diol having a cardo structure includes diols having a bisphenol derivative structure, but even if a diol having a cardo structure has a bisphenol derivative structure, it is still considered to be a diol having a cardo structure.

[0110] Examples of bisphenols that do not have a cardo structure 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 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.

[0111] 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.

[0112] 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.

[0113] (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.

[0114] 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 skeleton, such as 9,9-bis(carboxymethyl)fluorene and 9,9-bis(2-carboxyethyl)fluorene.

[0115] From the viewpoint of improving the solubility and mechanical strength of the polyester, terephthalic acid and isophthalic acid are preferred as aromatic dicarboxylic acids. 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.

[0116] 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.

[0117] 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.

[0118] (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.

[0119] (Preparation of Polyester) The polymerization method for 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, interfacial polymerization, or further solid-phase polymerization. In the polymerization of polyester, a dicarboxylic acid derivative such as an acid anhydride may be used as the dicarboxylic acid component.

[0120] From the viewpoint of ensuring the mechanical strength of a molded article such as a film formed from the resin composition, the weight average molecular weight of the polyester is preferably greater than 10,000, more preferably 15,000 or more, even 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.

[0121] 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.

[0122] Commercially available polyester resins may be used as the polyester. Examples of commercially available polyester resins containing a specific diol as a diol component include OKP4HT (manufactured by Osaka Gas Chemicals, Mw: 38,000, Tg: 142°C), OKP4 (manufactured by Osaka Gas Chemicals, Mw: 40,000, Tg: 121°C), 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 UE3510 (manufactured by Unitika, Mw: 63,000, Tg: -25°C), Elitel UE3 600 (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), Elitel UE9200 (manufactured by Unitika, Mw: 39,000, Tg: 65°C), Elitel UE980 ...800 (manufactured by Unitika, Mw: 46,000, Tg: 90°C), Elitel UE9800 (manufactured by Unitika, Mw: 46,000, Tg: 90°C), Elitel UE9800 (manufactured by Unitika, Mw: Examples of such copolymers include Vylon 200 (manufactured by Nichika, 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), Vylon 290 (manufactured by Toyobo, Mw: 61,000, Tg: 72°C), and Vylon 600 (manufactured by Toyobo, Mw: 38,000, Tg: 47°C).

[0123] <Preparation of Resin Composition Containing Polyamideimide and Other Resins> The above polyamideimide is mixed with other resins to prepare a resin composition. The above polyamideimide and acrylic resin may be compatible at any ratio. Furthermore, the above polyamideimide and polyester may be compatible at any ratio. Therefore, the ratio of resins in the resin composition is not particularly limited. The mixing ratio (weight ratio) of the polyamideimide resin to the other resin may be 98:2 to 2:98, 95:5 to 10:90, or 90:10 to 15:85.

[0124] The higher the proportion of polyamide-imide, the higher the elastic modulus of the film and the greater the tendency for mechanical strength to be excellent.The higher the proportion of other resins (acrylic resin or polyester), the less coloring there is in the film and the greater the tendency for transparency to be high.

[0125] In order to fully exert the effect of improving transparency by mixing polyamideimide with other resins, the ratio of the other resins to the total of polyamideimide and other resins 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.

[0126] Polyamideimides are polymers with a special molecular structure, and generally have low solubility in organic solvents and are not compatible with other polymers. However, as described above, polyamideimides containing specific diamine components and acid dianhydride components exhibit high solubility in organic solvents and are compatible with acrylic resins and polyesters.

[0127] A resin composition containing polyamideimide and other resins preferably has a single glass transition temperature in differential scanning calorimetry (DSC) and / or dynamic mechanical analysis (DMA). When a resin composition has a single glass transition temperature, it can be considered that the polyamideimide and other resins are completely compatible with each other. A film containing polyamideimide and other resins also preferably has a single glass transition temperature.

[0128] The resin composition may be a simple mixture of the polyamideimide resin precipitated as a solid with another resin, or may be a mixture of polyamideimide and another resin. Furthermore, when a polyamideimide solution is mixed with a poor solvent to precipitate the polyamideimide resin, another resin may be mixed into the solution, and the resin composition obtained by mixing the polyamideimide and another resin may be precipitated as a solid (powder).

[0129] The resin composition may be a mixed solution containing polyamideimide and another resin. 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 another resin.

[0130] The solvent for the solution containing polyamideimide and other resins is not particularly limited as long as it exhibits solubility in both polyamideimide and other resins. Examples of the solvent include amide-based solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; ether-based solvents such as tetrahydrofuran and 1,4-dioxane; ketone-based 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 methylene chloride. From the viewpoints of the solubility of polyamideimide and the compatibility of polyamideimide with other resins in the solution, amide-based solvents are preferred.

[0131] 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.

[0132] [Molded Articles and Films] The above-mentioned polyamideimides and resin compositions containing polyamideimides and other resins 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.

[0133] In one embodiment, the molded article is a film. The film may be molded by either a melting method or a solution method, but the solution method is preferred from the viewpoint of producing a film with excellent transparency and uniformity. In the solution method, a solution containing the polyamideimide is applied to a support, and the solvent is then dried and removed to obtain a film. Since the polyamideimide is compatible with acrylic resins and polyesters, it is possible to produce a highly transparent film by the solution method by using the polyamideimide in combination with other resins.

[0134] 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.

[0135] 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.

[0136] The film may be stretched in one or more directions for the purpose of improving the mechanical strength, etc. When the film is stretched, the polymer chains are oriented in the stretching direction, which tends to improve the strength of the film in the in-plane direction and suppress the occurrence of breakage or cracks in the film.

[0137] 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.

[0138] The conditions for stretching the film are not particularly limited. For example, the stretching temperature is about ±40°C of the glass transition temperature of the film. The stretching temperature 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, which may result in a decrease in the handleability of the film.

[0139] 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.

[0140] 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 20 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.

[0141] The haze of the film is not particularly limited, but is preferably 10% or less, more preferably 5% or less, even more preferably 4% or less, and may be 3.5% or less, 3% or less, 2% or less, or 1% or less. The lower the haze of the film, the better. As described above, polyamideimide is compatible with acrylic resins and polyesters, so a mixed resin film containing polyamideimide and other resins has low haze and excellent transparency, similar to a film made of polyamideimide alone.

[0142] The total light transmittance of the film is not particularly limited, but is preferably 60% or more, more preferably 80% or more, even more preferably 85% or more, and may be 87% or more, 88% or more, 89% or more, or 90% or more. A mixed resin film containing polyamideimide and another resin has a higher total light transmittance than a film made of polyamideimide alone, and can exhibit a total light transmittance of 90% or more.

[0143] The yellowness index (YI) of the film is not particularly limited, but is preferably 20 or less, more preferably 10 or less, and even more preferably 5.0 or less, and may be 4.0 or less, 3.0 or less, 2.0 or less, 1.5 or less, or 1.0 or less. The yellowness index of the film may be 0 or less (a negative value). A mixed resin film containing polyamideimide and another resin tends to have a smaller YI than a film of polyamideimide alone.

[0144] From the viewpoint of strength, the tensile modulus of the film is preferably 2.0 GPa or more, more preferably 2.5 GPa or more, even more preferably 3.0 GPa or more, and may be 3.5 GPa or more or 4.0 GPa or more. The pencil hardness of the film is preferably 4B or more, more preferably 2B or more, and even more preferably F or more, and may be H or more, 2H or more, or 3H or more.

[0145] The polyamideimide-containing film of the present invention is suitable for use as a display material due to its low coloration and high transparency. In particular, films with high mechanical strength can be applied to surface components such as display cover windows. Furthermore, since the polyamideimide is substantially free of specific fluorine structures, it is highly degradable and environmentally safe. When used in practice, the film of the present invention may be provided with an antistatic layer, an easy-adhesion layer, a hard coat layer, an antireflection layer, etc., on its surface.

[0146] The following examples will be used to further explain the present invention, but the present invention is not limited to these examples.

[0147] [Preparation of Polyamide-imide Resin] N,N-dimethylacetamide (DMAc) was placed in a separable flask and stirred under a nitrogen atmosphere. Diamine, tetracarboxylic dianhydride, and polybasic acid chloride were then added in the ratios shown in Tables 1 and 2, and the mixture was stirred under a nitrogen atmosphere for 5 to 48 hours to react, yielding a polyamic acid solution with a solids concentration of 18 wt %.

[0148] To 100 g of the polyamic acid solution, 5.5 g of pyridine was added as an imidization catalyst, and after complete dispersion, 8 g of acetic anhydride was added and the mixture was stirred at 90° C. for 3 hours to carry out imidization.

[0149] After the imidization, the solution was cooled to room temperature, and then 100 g of 2-propyl alcohol (hereinafter referred to as IPA) was added at a rate of 2 to 3 drops per second while stirring, causing polyamideimide to precipitate. 150 g of IPA was then added, and after stirring for approximately 30 minutes, the solution was subjected to suction filtration using a Kiriyama funnel. The resulting solid was washed with IPA and then dried for 12 hours in a vacuum oven set at 120°C, yielding a polyamideimide resin.

[0150] [Preparation of Polyamideimide Film] The polyamideimide resin described above was dissolved in dimethylformamide (DMF) to prepare a polyamideimide solution with a solids concentration of 5 to 30 wt %. In Comparative Examples 1 to 3 in Table 2, the polyamideimide was insoluble in DMF, and films could not be prepared, so further evaluations were not performed. The polyamideimide solution was applied to a non-alkali glass plate and dried by heating in the air for 15 minutes at 60°C, 15 minutes at 90°C, 15 minutes at 120°C, 150°C, 15 minutes at 180°C, and 15 minutes at 200°C to prepare a film with a thickness of approximately 50 μm.

[0151] [Evaluation] <Molecular Weight> The weight-average molecular weight (Mw) of the polyamideimide resins of Examples 1 to 10 was measured using a gel permeation chromatograph (HLC-8420GPC) manufactured by Tosoh Corporation under the following conditions: Eluent: LiBr (30 mM) + H3PO4 (30 mM) DMF solution sample concentration: 0.1 wt % Injection pressure: Approximately 1.3 to 1.7 MPa Injection volume: 10 μL Flow rate: 0.6 mL / min Guard column: TSK guard column Super AW-H Column: TSK gel AWM-H × 2 Column temperature: 40°C Detection conditions: RI, UV Molecular weight standard sample: Polystyrene (manufactured by Tosoh Corporation) Calibration curve order: 1st dimension

[0152] <Haze and Total Light Transmittance> The film was cut into a 3 cm square, and the 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.

[0153] <Yellowness Index> The film was cut into a 3 cm square, and the yellowness index (YI) was measured according to JIS K7373 using a spectrophotometer "SC-P" manufactured by Suga Test Instruments.

[0154] <Tensile modulus> The film was cut into a 10 mm wide strip and allowed to stand at 23°C / 55% RH for 1 day to condition the humidity. The tensile modulus was then measured using an AUTOGRAPH AGS-X manufactured by Shimadzu Corporation under the following conditions: Grip distance: 100 mm, Pulling speed: 20.0 mm / min, Measurement temperature: 23°C.

[0155] [Evaluation Results] The compositions of the polyamideimides of the Examples and Comparative Examples, and the evaluation results of the polyamideimide films of the Examples, are shown in Tables 1 and 2. In Comparative Examples 1 to 3, solvent-soluble polyamideimides were not obtained, so Table 2 shows only the compositions.

[0156] In Tables 1 and 2, and Tables 3 and 4 described below, the polyamideimide compositions (amounts of diamine, tetracarboxylic dianhydride, and polybasic acid) are shown as molar ratios where the total amount of diamine is taken as 100 parts by mole, and the compounds are described by the following abbreviations.

[0157] <Diamine> DFMOB: 2,2'-bis(difluoromethoxy)benzidine <Acid dianhydride> BPADA: 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride BPAF: 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride PMDA: pyromellitic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride <Polybasic acid chloride> TPC: terephthalic acid chloride TMAC: trimellitic anhydride chloride

[0158]

[0159]

[0160] The polyamideimides of Examples 1 to 5, which contained a specific diamine as the diamine component and a specific acid dianhydride as the acid dianhydride component, were soluble in organic solvents and could be used to prepare transparent films.On the other hand, the polyamideimides of Comparative Examples 1 to 3, which contained a specific diamine but no specific acid dianhydride, were insoluble in organic solvents.

[0161] These results demonstrate that by using a difluoromethoxy group-containing diamine, which is a diamine that does not contain a specific fluorine structure, as the diamine component and by appropriately selecting an acid dianhydride, it is possible to obtain a polyamideimide that is highly environmentally safe and has excellent solubility in organic solvents and transparency.

[0162] [Preparation of Resin Composition of Polyamideimide and Acrylic Resin, and Fabrication of Film] The polyamideimides of Examples 3, 4, and 5 and a commercially available polymethyl methacrylate resin ("Parapet HM1000" manufactured by Kuraray, glass transition temperature: 120°C, acid value: 0.0 mmol / g, hereinafter referred to as "HM") were mixed in a weight ratio of 50:50 in DMF to prepare a solution with a resin content of 10 to 20 wt %. This solution was applied to an alkali-free glass plate and dried by heating in air at 60°C for 15 minutes, 90°C for 15 minutes, 120°C for 15 minutes, 150°C for 15 minutes, 180°C for 15 minutes, and 200°C for 15 minutes to prepare a film with a thickness of approximately 50 μm.

[0163] The mixed resin film of polyamideimide and acrylic resin was evaluated in the same manner as the polyamideimide film. The composition of the polyamideimide, the type of acrylic resin, and the evaluation results of the film are shown in Table 3.

[0164]

[0165] The films of Examples 103, 104, and 105, which were mixed resin films of polyamideimide and acrylic resin, tended to have improved transparency compared to the polyamideimide-only films of Examples 3, 4, and 5. For example, the polyamideimide film of Example 5 had a YI of 9.1, whereas the YI of the film of Example 105 was reduced to 3.0, demonstrating improved total light transmittance and significantly improved transparency compared to films made of polyamideimide alone.

[0166] [Preparation of Polyamideimide and Polyester Resin Composition and Film Fabrication] The polyamideimides of Examples 1, 2, and 5 and a commercially available polyester resin were dissolved in DFM at a weight ratio of 50:50 to prepare a solution with a solids concentration of 10 to 20 wt %. The polyester resin used was Unitika's "Elitel UE3200" (weight average molecular weight: 16,000, glass transition temperature: 65°C; copolymer of terephthalic acid, isophthalic acid, neopentyl glycol, and ethylene glycol, hereinafter referred to as "UE3200") or Osaka Gas Chemicals' "OKP4HT" (weight average molecular weight: 38,000, glass transition temperature: 142°C, polyester containing a diol having a fluorene structure as a diol component).

[0167] The mixed resin solution was applied to a non-alkali glass plate and dried by heating in the atmosphere for 15 minutes at 60°C, 15 minutes at 90°C, 15 minutes at 120°C, 15 minutes at 150°C, 15 minutes at 180°C, and 15 minutes at 200°C to prepare a film approximately 30 μm thick. The polyamideimide composition, polyester resin type, and film evaluation results are shown in Table 4.

[0168]

[0169] It can be seen that the films of Examples 201 and 211, which are mixed resin films of polyamideimide and polyester resin, have smaller YI, higher total light transmittance, and significantly improved transparency compared to the film of Example 1, which is a film of polyamideimide alone. A comparison between Example 2 and Example 202, and a comparison between Example 5 and Example 205 also shows that the mixed resin films of polyamideimide and polyester resin have higher transparency than films of polyamideimide alone.

[0170] From the evaluation results of the mixed resin films of polyamideimide and acrylic resin in Examples 103, 104, and 105, and the mixed resin films of polyamideimide and polyester resin in Examples 201, 211, 202, and 205, it is clear that polyamideimides that use a difluoromethoxy group-containing diamine as the diamine component and that have an appropriately selected acid dianhydride exhibit solubility in organic solvents, have excellent compatibility with acrylic resins and polyesters, and can produce films with high transparency.

Claims

1. A polyamideimide having a diamine component, a tetracarboxylic dianhydride component, and a polybasic acid component, wherein the diamine component includes a diamine having a difluoromethoxy group, and the tetracarboxylic dianhydride component includes one or more tetracarboxylic dianhydrides selected from the group consisting of tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(trimellitic anhydride) esters.

2. The polyamideimide according to claim 1, wherein the diamine having a difluoromethoxy group is 2,2'-bis(difluoromethoxy)benzidine, 3,3'-bis(difluoromethoxy)benzidine, or 2,3'-bis(difluoromethoxy)benzidine.

3. The one or more tetracarboxylic dianhydrides selected from the group consisting of tetracarboxylic dianhydrides having an ether bond, tetracarboxylic dianhydrides having a cardo structure, and bis(trimellitic anhydride) esters are selected from the group consisting of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 5,5'-(9H-fluorene-9- The polyamideimide according to claim 1, wherein the polyamideimide is one or more selected from the group consisting of p-phenylenebis(2-methyl-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylate], p-phenylenebis(trimellitic acid monoester anhydride), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-biphenyl-4,4'-diyl, and bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)-2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diyl.

4. The polyamideimide according to claim 1, further comprising, as the tetracarboxylic dianhydride component, one or more tetracarboxylic dianhydrides selected from the group consisting of 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

5. The amount of CF on the carbon atom of the aromatic ring relative to the total amount of diamine components ３ - or -C(CF ３ ) ２ The amount of the diamine having a structure in which - is directly bonded is less than 0.5 mol %, and the amount of the diamine having a structure in which - is directly bonded to a carbon atom of an aromatic ring is less than 0.5 mol % based on the total amount of the tetracarboxylic dianhydride component. ３ - or -C(CF ３ ) ２ The amount of tetracarboxylic acid dianhydride having a structure in which - is directly bonded is less than 0.5 mol %, and the amount of CF bonded to the carbon atom of the aromatic ring is less than 0.5 mol % based on the total amount of the polybasic acid component. ３ - or -C(CF ３ ) ２ The polyamideimide according to claim 1, wherein the amount of the polybasic acid having a structure in which - is directly bonded is less than 0.5 mol %.

6. The polyamideimide according to claim 1, which is soluble in dimethylformamide at 23°C.

7. A molded article comprising the polyamideimide according to any one of claims 1 to 6.

8. A film comprising the polyamideimide according to any one of claims 1 to 6.

9. A resin composition comprising the polyamideimide according to any one of claims 1 to 6 and an acrylic resin.

10. The resin composition according to claim 9, wherein the polyamideimide and the acrylic resin are contained in a weight ratio ranging from 98:2 to 2:

98.

11. A molded article comprising the resin composition according to claim 9.

12. A film comprising the resin composition according to claim 9.

13. A resin composition comprising the polyamideimide according to any one of claims 1 to 6 and a polyester resin.

14. The resin composition according to claim 13, wherein the polyamideimide and the polyester resin are contained in a weight ratio ranging from 98:2 to 2:

98.

15. A molded article comprising the resin composition according to claim 13.

16. A film comprising the resin composition of claim 13.

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