JP2015054923A - Resin composition, resin film using the same, and method for producing the film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which makes it possible to produce a film with excellent mechanical properties with reduced cost.SOLUTION: The resin composition of the invention includes a polyamide-imide resin and an imidazole compound. In one embodiment, the above imidazole compound has a boiling point of 200°C or more. In one embodiment, the above polyamide-imide resin is obtained by reacting the following (a) and (b-1)-(b-3): in which (a) is a tricarboxylic acid anhydride, (b-1) is 3,3'-dimethylbiphenyl-4,4'-diisocyanate, (b-2) is a polyol with a terminal hydroxyl group modified with a diisocyanate, and (b-3) is an aromatic diisocyanate other than (b-1).

Description

  The present invention relates to a resin composition, a resin film using the resin composition, and a method for producing the resin film.

  Conventionally, as various conductive belts used in electrophotographic image forming apparatuses such as copying machines and printing machines, conductive belts formed from a material in which conductive carbon is dispersed in polyimide resin are widely used. . However, a conductive belt using a polyimide resin has a problem of high cost.

JP 2009-166388 A JP 2010-139925 A

  An object of the present invention is to provide a resin composition capable of producing a film having excellent mechanical properties at low cost.

The resin composition of the present invention contains a polyamideimide resin and an imidazole compound.
In one embodiment, the boiling point of the imidazole compound is 200 ° C. or higher.
In one embodiment, the polyamideimide resin is obtained by reacting the following (a) and (b-1) to (b-3):
(A) Tricarboxylic acid anhydride (b-1) 3,3′-dimethylbiphenyl-4,4′-diisocyanate (b-2) Polyols whose terminal hydroxyl groups are modified with diisocyanate (b-3) Other than (b-1) Aromatic diisocyanates.
In one embodiment, the polyamideimide resin is polymerized using a cyclic amine as a catalyst.
In one embodiment, the polyol obtained by modifying the terminal hydroxyl group with diisocyanate is obtained by reacting a polyester polyol containing a branched structure with diisocyanate.
In one embodiment, the resin composition of the present invention further comprises a conductive polymer.
In one embodiment, the conductive polymer is a conductive polyaniline.
According to another aspect of the present invention, a resin film is provided. This resin film is obtained using the above resin composition, and includes a polyamideimide resin and an imidazole compound.
According to still another aspect of the present invention, a seamless belt is provided. This seamless belt is composed of the resin film.
According to still another aspect of the present invention, a method for producing a resin film is provided. The method for producing this resin film includes a step of reacting an acid component and a diisocyanate component to obtain a polyamideimide resin, a step of preparing a resin composition by mixing the polyamideimide resin and an imidazole compound, And applying a heat treatment after applying the resin composition to the substrate.
In one embodiment, a cyclic amine is used as a catalyst in the step of obtaining a polyamide-imide resin by reacting an acid component containing the tricarboxylic acid anhydride with a diisocyanate component.

  The resin composition of the present invention contains a polyamideimide resin and an imidazole compound. Since the film obtained using the resin composition of the present invention is based on a polyamideimide resin, the cost is low and the mechanical properties (for example, folding resistance, elastic modulus, strength, elongation) are excellent. Specifically, according to the resin composition of the present invention, a film having mechanical properties equal to or higher than that of a polyimide resin film can be produced. The resin composition of the present invention can be particularly suitably used for seamless belt applications such as printing presses that require mechanical strength.

A. Resin Composition The resin composition of the present invention contains a polyamideimide resin and an imidazole compound.

A-1. Polyamideimide resin The polyamideimide resin is, for example, a diisocyanate method in which an acid component and a diisocyanate component are reacted in any appropriate solvent, an acid chloride method in which trimellitic anhydride chloride and diamine are reacted, or trimellitic anhydride. It can be synthesized by a direct polymerization method in which a product and a diamine are reacted. Of these, the diisocyanate method is preferred because of its excellent work efficiency.

  The mixing ratio of the acid component and the diisocyanate component used for the synthesis of the polyamideimide resin is preferably 0.8 to 1.4, more preferably 0.9 to 1.3 in terms of equivalent ratio (diisocyanate component / acid component). More preferably, it is 0.9-1.2.

  The number average molecular weight of the polyamideimide resin (a value measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve) is preferably 5,000 to 50,000, more preferably 10,000. 000 to 40,000, more preferably 15,000 to 35,000. When the number average molecular weight of the polyamideimide resin is outside the above range, film formation may be difficult, or the mechanical properties of the film obtained using the polyamideimide resin may be significantly reduced.

A-1-1. Acid component The acid component preferably contains a tricarboxylic acid anhydride. Examples of the tricarboxylic acid anhydride include trimellitic acid anhydride and cyclohexanetricarboxylic acid anhydride. Trimellitic anhydride is preferable from the viewpoints of cost, reactivity, solubility, and the like. A tricarboxylic acid anhydride may be used independently and may be used in combination of 2 or more type.

  The acid component may contain an acid component other than the tricarboxylic acid anhydride. Any appropriate acid component is used as the other acid component. For example, tetracarboxylic dianhydrides such as pyromellitic anhydride, biphenyltetracarboxylic dianhydride and oxydiphthalic anhydride; aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid; alicyclic dicarboxylics such as cyclohexanedicarboxylic acid Acid; aliphatic dicarboxylic acids such as adipic acid and sebacic acid; Another acid component may be used independently and may be used in combination of 2 or more type.

  The molar ratio of the tricarboxylic acid anhydride to the acid component (tricarboxylic acid anhydride / acid component) is preferably 0.5 to 1.0, more preferably 0.7 to 1.0.

A-1-2. Diisocyanate component Examples of the diisocyanate contained in the diisocyanate component include 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, tetramethylxylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, naphthalene diisocyanate, and the like. Aromatic diisocyanates; aliphatic isocyanates such as hexamethylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, norbornene diisocyanate, and dicyclohexylmethane diisocyanate. A diisocyanate may be used independently and may be used in combination of 2 or more type.

(Aromatic diisocyanate)
The diisocyanate component preferably contains an aromatic diisocyanate, more preferably 3,3′-dimethylbiphenyl-4,4′-diisocyanate. If a diisocyanate component containing such an aromatic diisocyanate is used, a polyamide-imide resin capable of forming a highly elastic resin film can be synthesized. In the present specification, the aromatic diisocyanate means a diisocyanate having an aromatic group and having no polyol-derived structural unit.

  The molar ratio of the aromatic diisocyanate to the diisocyanate component (aromatic diisocyanate / diisocyanate component) is preferably 0.5 to 0.995, more preferably 0.8 to 0.995, and still more preferably 0.8. 9-0.99.

  The molar ratio of 3,3′-dimethylbiphenyl-4,4′-diisocyanate to the aromatic diisocyanate is preferably 0.3 to 0.9, more preferably 0.5 to 0.8. If the molar ratio of 3,3′-dimethylbiphenyl-4,4′-diisocyanate to aromatic diisocyanate is within the above range, a polyamideimide resin capable of forming a highly elastic resin film can be synthesized.

(Polyol whose terminal hydroxyl group is modified with diisocyanate)
The diisocyanate component preferably contains a polyol having a terminal hydroxyl group modified with diisocyanate (hereinafter also referred to as an isocyanate-modified polyol). If a diisocyanate component containing an isocyanate-modified polyol is used, a polyamide-imide resin that can form a resin film having a high tensile modulus and excellent folding resistance can be synthesized.

  The molar ratio of the isocyanate-modified polyol to the diisocyanate component (isocyanate-modified polyol / diisocyanate component) is preferably 0.005 to 0.2, more preferably 0.01 to 0.1. When the molar ratio of the isocyanate-modified polyol to the diisocyanate component is less than 0.005, the effect of improving mechanical properties may not be sufficiently obtained. When the molar ratio of the isocyanate-modified polyol to the diisocyanate component exceeds 0.2, the properties of the polyamideimide resin may not be sufficiently exhibited.

  The number average molecular weight of the isocyanate-modified polyol (a value measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve) is preferably 500 to 10,000, more preferably 1,000 to It is 9,500, More preferably, it is 1,500-9,000. When the number average molecular weight of the isocyanate-modified polyol is less than 500, the elongation at break of the film containing the obtained polyamideimide resin may be lowered. When the number average molecular weight of the isocyanate-modified polyol exceeds 10,000, the reactivity of the diisocyanate decreases, and it tends to be difficult to increase the molecular weight of the polyamideimide resin.

  The isocyanate-modified polyol can be obtained by reacting a polyol with a diisocyanate having a molar equivalent of 2 times or more with respect to the polyol in any appropriate solvent. Solvents used for the reaction include ketone solvents such as N-methyl-2-pyrrolidone, ester solvents, ether solvents, cellosolve solvents, aromatic hydrocarbon solvents, tetrahydrofuran, dioxane N, N-dimethylformamide. , N, N-dimethylacetamide, dimethyl sulfoxide and the like. The reaction temperature can be set to, for example, 100 ° C to 150 ° C. The reaction time can be set to 1 hour to 5 hours, for example.

  The number average molecular weight of the polyol (a value measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve) can be set to any appropriate value. The number average molecular weight of the polyol is preferably 500 to 8,000, more preferably 1,000 to 4,000. When the number average molecular weight of the polyol is within the above range, a polyamideimide resin composition capable of forming a resin film having excellent mechanical properties can be obtained.

  Examples of the polyol include polycarbonate polyol, polyether polyol, and polyester polyol. Of these, polyester polyol is preferable. The polyester polyol can be obtained, for example, by condensation polymerization of a dicarboxylic acid and a diol. A commercial item may be used for the polyester polyol. Examples of commercially available linear (not including a branched structure) polyester polyol include trade names “OD-X-102”, “OD-X-668”, and “OD-X-2068” manufactured by DIC. . Examples of commercially available polyester polyols having a branched structure include trade names “P-1010”, “P-2010”, “P-3010”, “P-4010”, “P-1020”, “P-” manufactured by Kuraray Co., Ltd. 2020 "," P-1030 "," P-2030 "," P-1050 "," P-2050 "," P-3050 "," P-4050 ", and the like.

  Any appropriate dicarboxylic acid can be used as the dicarboxylic acid. Examples thereof include aliphatic carboxylic acids such as adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid; aromatic carboxylic acids such as terephthalic acid and isophthalic acid.

  Any appropriate diol can be used as the diol. For example, diols having a linear structure such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, diethylene glycol; 1,2-propylene glycol, 1,3-butylene glycol, 2 -Methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentadiol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,8-octanediol, etc. Examples include diols having a branched structure.

  The hydroxyl value of the polyester polyol is set to any appropriate value. The hydroxyl value of the polyester polyol is usually 15 mgKOH / g to 230 mgKOH / g, preferably 18 mgKOH / g to 140 mgKOH / g, more preferably 25 mgKOH / g to 115 mgKOH / g. When the hydroxyl value exceeds 230 mgKOH / g, the obtained film may not have sufficient breaking strength and breaking elongation. When the hydroxyl value is less than 15 mgKOH / g, the reactivity between the polyester polyol and the diisocyanate is lowered, and it may be difficult to obtain a desired polyamideimide resin.

  As the polyester polyol, it is preferable to use a polyester polyol containing a branched structure. If the polyester polyol containing a branched structure is used, a polyamideimide resin capable of forming a resin film having excellent flexibility can be synthesized. The polyester polyol containing a branched structure can be obtained, for example, by condensation polymerization of a dicarboxylic acid and a diol containing a branched structure.

  In one embodiment, it is possible to obtain a polyamide-imide resin capable of forming a film with higher elastic modulus and strength and capable of forming a film with further excellent mechanical properties. Only the polyester polyols contained are used. By using a polyester polyol containing a branched structure, it is presumed that the cohesive force between molecular chains is weakened and flexibility is imparted to the resulting polyamideimide resin. Therefore, it is considered that a polyamideimide resin capable of forming a film having further excellent mechanical properties can be obtained by using a polyester polyol having a branched structure.

  In another embodiment, in order to adjust properties other than mechanical properties of the obtained film, a polyester polyol containing a branched structure and a polyester polyol having a linear structure (not containing a branched structure) may be used in combination. When a polyester polyol having a branched structure and a polyester polyol having a linear structure are used in combination, the molar ratio between the polyester polyol having a branched structure and the polyester polyol having a linear structure (polyester polyol having a branched structure / polyester polyol having a linear structure) ) Is, for example, 9.9 / 0.1 to 5.0 / 5.0, and preferably 9.9 / 0.1 to 7.0 / 3.0.

  The polyester polyol containing the above branched structure can be obtained by combining any suitable dicarboxylic acid and a diol containing any suitable branched structure. As a polyester polyol containing a branched structure, polyester obtained by using adipic acid as a dicarboxylic acid and 3-methyl-1,5-pentadiol as a diol containing a branched structure from the viewpoint of reactivity, handling properties, and cost Polyol polyol obtained by using adipic acid as a polyol, dicarboxylic acid and neopentyl glycol as a diol containing a branched structure, and adipic acid as a dicarboxylic acid and 2-methyl-1,8-octane as a diol containing a branched structure Polyester polyols obtained using diols are preferred.

  Arbitrary appropriate groups are contained as group (side chain of polyester polyol) which constitutes the branched structure of polyester polyol containing the above-mentioned branched structure. For example, C1-C5 alkyl groups, such as a methyl group, etc. are mentioned. From the viewpoints of reactivity, handling properties, and cost, a polyester polyol containing an alkyl group having 1 to 5 carbon atoms as a branched structure is preferable. The polyester polyol containing the above group can be obtained, for example, by condensation polymerization of a diol containing this group and any appropriate dicarboxylic acid.

  The polyester polyol containing a branched structure preferably contains 50% by weight to 100% by weight of a repeating unit containing a branched structure. When the repeating unit containing a branched structure is 50% by weight to 100% by weight, the mechanical properties of the film obtained using the polyamideimide resin can be further improved.

  Any appropriate diisocyanate can be used as the diisocyanate to be reacted with the polyol. For example, aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, tetramethylxylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, naphthalene diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate And cycloaliphatic diisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, norbornene diisocyanate, and dicyclohexylmethane diisocyanate. These diisocyanates may be used alone or in combination of two or more.

A-1-3. Synthesis of Polyamideimide Resin The polyamideimide resin can be synthesized , for example, by reacting the acid component and the diisocyanate component in any appropriate solvent (diisocyanate method).

  Examples of the solvent used for reacting the acid component with the diisocyanate component include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, and γ-butyrolactone.

  A catalyst may be used for the synthesis of the polyamideimide resin, if necessary. Any appropriate catalyst can be used as the catalyst. Examples thereof include cyclic amines such as diazabicycloundenecene, triethylenediamine, potassium fluoride, cesium fluoride, and the like. The addition amount of the catalyst can be set to any appropriate value depending on the amount of materials used for the reaction, reaction conditions, and the like.

  In the present invention, it is preferable to use a cyclic amine as the catalyst, and it is more preferable to use diazabicycloundenecene. If such a catalyst is used, a polyamidoimide resin with many amide bonds can be obtained. As will be described later, the amide bond can be a starting point of an intermolecular imide bond due to the action of an imidazole compound, and therefore, if a polyamide-imide resin having many amide bonds is used, a resin film having an excellent balance of mechanical properties can be obtained. it can.

  In the synthesis of the polyamideimide resin, the reaction temperature and reaction time may be set as appropriate. For example, the reaction temperature can be set to 100 ° C. to 250 ° C., and the reaction time can be set to 3 hours to 20 hours.

In one embodiment, a polyamidoimide resin is obtained by superposing | polymerizing using said acid component and diisocyanate component in the following combinations. The polyamideimide resin thus obtained has a good balance of mechanical properties, and can form a resin film having excellent folding resistance.
(A) Tricarboxylic acid anhydride (acid component)
(B-1) 3,3′-dimethylbiphenyl-4,4′-diisocyanate (diisocyanate component)
(B-2) Isocyanate-modified polyol (diisocyanate component)
(B-3) Aromatic diisocyanates other than (b-1) (diisocyanate component)

A-2. Imidazole-based compound The resin composition of the present invention is obtained by mixing a polymerized polyamideimide resin and an imidazole-based compound. When the resin composition of the present invention is used, the polyamideimide resin can be formed at a lower temperature or in a shorter time than when no imidazole compound is mixed due to the action of the imidazole compound when forming a molded body (for example, a film). Between the amide bonds, it becomes easy to form an imide bond. As a result, the film obtained using the resin composition of the present invention is composed of a resin having many crosslinking points. When such a film is pulled, the molecular chain extends from the cross-linking point, and the separation rate of the molecular chains decreases. Therefore, if the resin composition of the present invention is used, it is possible to obtain a film having excellent mechanical properties and particularly excellent folding resistance. The imidazole compound is a concept including imidazole and imidazole derivatives. Hereinafter, in the present specification, an imide bond between polyamideimide resins is referred to as an intermolecular imide bond, as distinguished from an imide bond in the polyamideimide resin.

  Examples of the imidazole compound include imidazole, 2-methylimidazole, 2-phenylimidazole, 1,3-dimethylimidazole, 2-ethyl 4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2- Examples include phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl 4-methylimidazole, and the like. Of these, 2-methylimidazole or 2-phenylimidazole is preferable. If such an imidazole compound is used, a resin composition capable of forming a film having excellent mechanical properties can be obtained. In addition, you may use an imidazole type compound individually or in combination of 2 or more types.

  The boiling point of the imidazole compound is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, and further preferably 260 ° C. or higher. If it is such a range, it can prevent that an imidazole type compound reduces by the heating at the time of forming a molded object (for example, film). Examples of the imidazole compound having a boiling point in the above range include 2-methylimidazole (boiling point: 267 ° C.) and 2-phenylimidazole (boiling point: 340 ° C.).

  In the resin composition, the content ratio of the imidazole compound is preferably 5 mmol to 30 mmol, more preferably 8 mmol to 30 mmol, and further preferably 10 mmol to 30 mmol with respect to 100 g of the polyamideimide resin. If it is such a range, since a polyamide-imide resin can be bridge | crosslinked moderately, it can obtain the resin composition which can form the resin film which is excellent in the balance of mechanical characteristics, and is excellent in especially bending resistance.

A-3. Conductive polymer The resin composition may further contain a conductive polymer. The resin composition containing a conductive polymer can be used as a film material for forming a conductive belt such as an intermediate transfer belt.

  The content of the conductive polymer in the resin composition can be set to any appropriate value according to desired electrical characteristics and mechanical characteristics. The content of the conductive polymer is preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight with respect to 100 parts by weight of the polyamideimide resin.

  Any appropriate polymer can be used as the conductive polymer. Examples of conductive polymers include polythiophene polymers, polyacetylene polymers, polyparaphenylene polymers, polyaniline polymers, polyparaphenylene vinylene polymers, polypyrrole polymers, polyphenylene polymers, and polyester polymers modified with acrylic polymers. Examples thereof include polymers.

  Preferably, a polyaniline polymer is used as the conductive polymer. In the present invention, a molded body (for example, a film) can be formed at a lower temperature or in a shorter time by using a combination of a polyamideimide resin and an imidazole compound and a polyaniline polymer. Deterioration can be reduced. As a result, it is possible to obtain a molded body with little decrease in conductivity. Moreover, the effect of cost reduction can also be acquired.

(Conductive polyaniline)
The polyaniline-based polymer is a conductive polyaniline obtained by adding a dopant to polyaniline in an emeraldine base state having a reduced structural unit.

  Preferably, the conductive polyaniline is obtained by adding an excess of dopant to the emeraldine-based polyaniline having a reduced structural unit in an amount that can be added to the polyaniline. Specifically, it is preferable to add more than 2 mol of dopant to 1 mol of the reduced structural unit of the polyaniline to the emeraldine-based polyaniline.

（式中、ｍは繰り返し単位中の酸化型構造単位のモル分率を示し、ｎは繰り返し単位中の還元型構造単位のモル分率を示し、ｍ＋ｎ＝１であり、ｍとｎの値は略等しい。） The polyaniline in the emeraldine base state (hereinafter also simply referred to as polyaniline) repeats a basic skeleton in which an oxidized structural unit and a reduced structural unit are present in substantially equal molar fractions as represented by the following formula (1). Have as a unit.

(In the formula, m represents the molar fraction of the oxidized structural unit in the repeating unit, n represents the molar fraction of the reduced structural unit in the repeating unit, m + n = 1, and the values of m and n are Approximately equal.)

  The method for producing the polyaniline is described in, for example, JP-A-3-28229, the description of which is incorporated herein by reference.

  Any appropriate dopant can be adopted as long as the dopant can impart conductivity by doping the polyaniline. The dopant is preferably a protonic acid. The proton acid may be an organic acid or an inorganic acid.

  The acid dissociation constant pKa value of the protonic acid is preferably 4.8 or less, more preferably 1 to 4.8. Examples of such a protonic acid include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, borohydrofluoric acid, phosphorous hydrofluoric acid and perchloric acid; organic acids having an acid solubility constant pKa value of 4.8 or less. Etc. When a protonic acid having a pKa value of 1 to 4.8 is used, the smaller the pKa value, that is, the stronger the acidity, the higher the conductive resin composition can be obtained. However, usually, when the pKa value is smaller than 1, the conductivity of the resulting resin composition does not change beyond a certain level. Of course, if necessary, a protonic acid having a pKa value of 1 or less may be used.

  Examples of the organic acid include aliphatic organic acids such as organic carboxylic acids; aromatic organic acids such as phenols or araliphatic organic acids; alicyclic organic acids and the like. These organic acids may be monobasic acids or polybasic acids. The organic acid may have a substituent. Examples of the substituent include a sulfonic acid group, a sulfuric acid group, a hydroxyl group, a halogen group, a nitro group, a cyano group, and an amino group.

  Specific examples of the organic acid include acetic acid, butyric acid, octanoic acid, formic acid, oxalic acid, benzoic acid, picric acid, salicylic acid, 1,6-dinitro-4-chlorophenol, 2,6-dinitrophenol, 2,4 -Dinitrophenol, mandelic acid, phthalic acid, isophthalic acid, maleic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, α-alanine, β-alanine, glycine, glycolic acid, derivatives thereof, etc. Can be mentioned.

  Specific examples of the organic acid having a sulfonic acid group and / or a sulfuric acid group include amino naphthol sulfonic acid; metanilic acid; sulfanilic acid; allyl sulfonic acid; lauryl sulfuric acid; xylene sulfonic acid; chlorobenzene sulfonic acid; Sulfonic acid; benzenesulfonic acid; styrenesulfonic acid; p-toluenesulfonic acid; naphthalenesulfonic acid; ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, Octylbenzenesulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, octadecylbenzenesulfonic acid Alkylbenzenesulfonic acid such as rubenzenesulfonic acid; Dialkylbenzenesulfonic acid such as diethylbenzenesulfonic acid; Alkylnaphthalenesulfonic acid such as methylnaphthalenesulfonic acid, ethylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid; Dimethylnaphthalenesulfonic acid, diethylnaphthalenesulfonic acid Trialkylnaphthalenesulfonic acid; triethylnaphthalenesulfonic acid; tripropylnaphthalenesulfonic acid; tributylnaphthalenesulfonic acid; camphorsulfonic acid; acrylamide-t-butylsulfonic acid and the like.

  As the organic acid, a polyfunctional organic sulfonic acid having two or more sulfonic acid groups in the molecule can also be used. Specific examples of the polyfunctional organic sulfonic acid include alkyl disulfonic acids such as ethanedisulfonic acid and propanedisulfonic acid; benzene disulfonic acid; alkylbenzene disulfonic acids such as naphthalenedisulfonic acid; dialkylbenzenes such as dimethylbenzene disulfonic acid and diethylbenzene disulfonic acid. Examples include disulfonic acid; alkyl naphthalene disulfonic acid such as methyl naphthalene disulfonic acid and ethyl naphthalene disulfonic acid; dialkyl naphthalene sulfonic acid such as diethyl naphthalene disulfonic acid and the like. When the polyfunctional organic sulfonic acid has an aromatic ring, any appropriate position can be selected as the position of the sulfonic acid group in the aromatic ring.

  The organic acid may be a polymer acid. Specific examples of the polymer acid include polyvinyl sulfonic acid, polyvinyl sulfuric acid, polystyrene sulfonic acid, sulfonated styrene-butadiene copolymer, polyallyl sulfonic acid, polymethallyl sulfonic acid, poly-2-acrylamido-2-methylpropane. Examples include sulfonic acid, polyhalogenated acrylic acid, polyisoprene sulfonic acid, N-sulfoalkylated polyaniline, and nuclear sulfonated polyaniline. A fluorine-containing polymer known as naphthion (registered trademark of DuPont, USA) is also preferably used as the polymer acid.

  Among the organic acids exemplified above, an organic acid having a sulfonic acid group is preferable, more preferably dodecylbenzenesulfonic acid or camphorsulfonic acid, and still more preferably dodecyl because it is inexpensive and has excellent handleability. Benzenesulfonic acid.

  In one embodiment, the conductive polyaniline is obtained by stirring and mixing the polyaniline and the dopant and heating the mixture. The stirring time is preferably 1 minute to 60 minutes, more preferably 2 minutes to 20 minutes, and further preferably 3 minutes to 10 minutes. The heating time is preferably 1 minute to 60 minutes, more preferably 2 minutes to 20 minutes, and even more preferably 3 minutes to 10 minutes. The heating temperature is preferably 120 ° C to 200 ° C, particularly preferably 140 ° C to 180 ° C.

  In another embodiment, the conductive polyaniline is obtained by heat-kneading the polyaniline and the dopant. It is considered that the conductive polyaniline obtained by heating and kneading is entangled in molecular chains. The conductive polyaniline obtained by heating and kneading is excellent in storage stability without being gelated even when dissolved in a polar solvent and stored for a long period of time (for example, 1 month or longer). Examples of the apparatus that can be used for the heat kneading include a closed kneading apparatus such as a Banbury mixer, a kneader, and a roll, or a batch kneading apparatus; a continuous kneading apparatus such as a single screw extruder and a twin screw extruder. .

  The kneading temperature in the heat kneading is preferably 120 ° C. to 200 ° C., particularly preferably 140 ° C. to 180 ° C. If the kneading temperature is in such a range, the molecular chains of the polyaniline are entangled, and as a result, a conductive polyaniline sufficiently doped with the dopant can be obtained, and further, it is difficult to gel in a polar solvent. It is estimated that a resin composition can be obtained.

  The kneading time in the above heat kneading is preferably 1 minute to 60 minutes. When the kneading time is in such a range, the conductive polyaniline sufficiently doped with the proton acid can be obtained, and further, a resin composition that is hardly gelled in a polar solvent can be obtained.

  As described above, the addition amount of the dopant is preferably more than 2 mol with respect to 1 mol of the reduced structural unit of the polyaniline. The amount of the dopant added is more preferably 3 mol to 6 mol with respect to 1 mol of the reduced structural unit of the polyaniline.

  Theoretically, 2 mol of dopant can be added to 1 mol of the reduced structural unit of the polyaniline. In the present invention, the conductive polyaniline can be sufficiently obtained by adding an excessive amount of dopant to the polyaniline beyond the theoretically possible amount. If the resin composition which fully contains electroconductive polyaniline is used, the electroconductive material (for example, electroconductive film) excellent in electroconductivity and a softness | flexibility can be obtained. On the other hand, even if the amount of dopant added is too large, the actual amount of dopant added to polyaniline does not exceed the theoretical value. When the amount of dopant added per mol of reduced structural unit of polyaniline is more than 6 mol, the resin composition There exists a possibility that the residual dopant in it cannot be removed efficiently.

  By preparing as described above, most of the reduced structural unit of the polyaniline is doped (that is, most of the polyaniline is converted into conductive polyaniline). The ratio of the doped reduced structural unit is preferably 80 mol% or more, more preferably 90 mol% or more, based on the total of the doped reduced structural unit and the undoped reduced structural unit. More preferably, it is 98 mol% or more, and particularly preferably 100 mol%.

  Further, the ratio of the doped reduced structural unit is preferably 40 mol% or more, more preferably, based on the total of the oxidized structural unit and the reduced structural unit in the polyaniline (that is, before the addition of the dopant). It is 45 mol% or more, more preferably 49 mol% or more, and most preferably 50 mol%.

  It is preferable that the dopant added excessively as described above is removed by any appropriate method. If a resin composition containing conductive polyaniline prepared by adding the above-mentioned amount of dopant and substantially free of residual dopant is used, a conductive material having both conductivity and mechanical strength (for example, A conductive film) can be formed. In the present specification, the phrase “substantially free of residual dopant” means that the content ratio of residual dopant in the resin composition is 10 parts by weight or less with respect to 100 parts by weight of conductive polyaniline. The content ratio of the dopant in the resin composition is preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and further preferably 1 part by weight or less with respect to 100 parts by weight of the conductive polyaniline. Most preferably, the resin composition of the present invention contains no residual dopant.

  The removal of the residual dopant can be performed, for example, by adding a solvent capable of dissolving only the residual dopant to the mixture containing the conductive polyaniline and the residual dopant, washing the mixture, and then filtering. Examples of the solvent include water, methanol and the like.

  The resin composition may contain any appropriate additive depending on the purpose and the like. Examples of the additive include a slidable filler, a heat conductive filler, a heat insulating filler, and an abrasion resistant filler. The additive may be added during the preparation of the conductive polyaniline, or may be added after the residual dopant removing step.

B. Resin film The resin film of this invention is formed using the said resin composition, and contains the said polyamidoimide resin. Therefore, the resin film of the present invention retains sufficient elasticity and is excellent in other mechanical properties. Moreover, when the resin film obtained using the resin composition of the present invention is formed, the polyamideimide resin is appropriately cross-linked by the action of the imidazole compound, and is excellent in folding resistance. Since the resin film of the present invention is excellent in mechanical properties, it can be used for various applications. Of these, seamless belts such as intermediate transfer belts, fixing belts, and transport belts used in copying machines and the like that particularly require excellent mechanical properties can be suitably used. Moreover, if the resin composition containing the said conductive polymer is used, electroconductivity can be provided to these belts. In one embodiment, the resin film of the present invention may contain the imidazole compound in addition to the polyamideimide resin.

  The resin film of this invention can be obtained by apply | coating the said resin composition to arbitrary appropriate base materials, producing a coating film, removing a solvent from this coating film, and heat-processing. Any appropriate method can be used as a method of applying the resin composition to the substrate. The method for producing the resin composition is as described in the above section A. That is, the method for producing a resin film of the present invention prepares a resin composition by mixing an acid component and a diisocyanate component to obtain a polyamideimide resin, and mixing the polyamideimide resin and an imidazole compound. And a step of performing a heat treatment after applying the resin composition to the substrate.

  In the step of obtaining a polyamideimide resin by reacting an acid component with a diisocyanate component, it is preferable to use a cyclic amine as a catalyst. It is preferable to use diazabicycloundenecene as the cyclic amine.

  As said base material, glass, a metal, a polymer film etc. are mentioned, for example. Moreover, the resin film for seamless belts can be produced by using a cylindrical metal mold | die as said base material. The resin film for the seamless belt is produced, for example, by supplying the resin composition into a cylindrical mold to form a coating film on the inner surface of the mold, and then removing the solvent by heat treatment and drying. .

  Any appropriate method is adopted as a method of forming the coating film when the resin film for the seamless belt is produced. For example, a method of supplying a coating liquid into a rotating mold and forming a uniform coating film by centrifugal force, inserting a nozzle along the inner surface of the mold, and discharging the coating liquid from the nozzle into the rotating mold. A method of applying a spiral while running a nozzle or a mold, or a method of running a traveling body (bullet shape, spherical shape) having a certain clearance between the mold after the spiral application is performed roughly After immersing the mold in the coating liquid to form a coating film on the inner surface, a method of forming a film with a cylindrical die or the like, after supplying the coating liquid to one end of the inner surface of the mold, between the mold Examples thereof include a method of traveling a traveling body (bullet shape, spherical shape) having a certain clearance.

  The temperature of the heat treatment is preferably 100 ° C to 300 ° C, more preferably 150 ° C to 250 ° C, and further preferably 150 ° C to 200 ° C. The heat treatment time is preferably 10 minutes to 60 minutes. In the present invention, the polyamideimide resin is appropriately crosslinked by the action of the imidazole compound during the heat treatment.

The degree of cross-linking of the polyamide-imide resin can be determined by the amount of intermolecular imide bonds. The amount of intermolecular imide bond can be measured using infrared spectroscopy as follows.
(I) The FT-IR absorption spectrum of the resin film is measured.
(Ii) The peak intensity B (peak area) of the C═C bond peak of the benzene ring derived from the diisocyanate component is determined. In addition, when 2 or more types of isocyanate is included, the value which averaged each peak intensity is made into peak intensity B.
(Iii) The peak intensity I ₁ (peak area) of the peak (near 1780 cm ⁻¹ ) derived from the C═O bond of the imide bond (intramolecular imide bond) constituting the molecular chain of the polyamideimide resin is determined.
(Iii) The peak intensity I _a (peak area) of the peak (near 1380 cm ⁻¹ ) derived from the C═O bond of all imide bonds (that is, the sum of intramolecular imide bonds and intermolecular imide bonds) in the resin film. Ask.
(Iv) The ratio of the peak intensity I _{1 to} the peak intensity B is defined as the amount of intramolecular imide bond.
(V) the ratio of the peak intensity I _a to the peak intensity B, and the amount of total imide bond in the resin film.
(Vi) (amount of total imide bond) − (amount of intramolecular imide bond), that is, a value calculated from (peak intensity I _a / peak intensity B) − (peak intensity I ₁ / peak intensity B), The amount of intermolecular imide bond.

  In the resin film, the amount of the intermolecular imide bond is preferably 0.75 or more, more preferably 0.8 or more, and further preferably 0.85 or more.

  The thickness of the resin film can be set to any appropriate thickness depending on the application. Typically, it is 25 μm to 150 μm, and more preferably 50 μm to 100 μm.

  The folding resistance of the resin film according to MIT test according to JIS P8115 is preferably 3000 times or more, more preferably 3500 times or more, further preferably 4000 times or more, and particularly preferably 4000 times to 10,000. Times. In the resin film formed using the resin composition of the present invention, the polyamideimide resin is appropriately cross-linked and has excellent folding resistance. Moreover, when providing electroconductivity to a resin composition, as above-mentioned, it contains the fully doped electroconductive polyaniline, and it is made not to contain a residual dopant substantially, The polyamide by a dopant Deterioration of the imide resin can be prevented. As a result, a conductive film having excellent mechanical properties (specifically, having a large number of folding times as described above) can be obtained.

  The tensile elastic modulus at 25 ° C. of the resin film is preferably 1 GPa or more, more preferably 2 GPa or more, and further preferably 3 GPa to 20 GPa. A method for measuring the tensile modulus will be described later.

  The breaking strength at 25 ° C. of the resin film is preferably 50 MPa or more, more preferably 80 MPa or more, further preferably 100 MPa or more, particularly preferably 140 MPa to 500 MPa, and most preferably 150 MPa to 500 MPa. is there. A method for measuring the breaking strength will be described later.

  The elongation at break of the resin film at 25 ° C. is preferably 5% or more, more preferably 10% or more, still more preferably 20% to 60%, and particularly preferably 20% to 40%. A resin film having a break elongation in such a range is excellent in durability. A method for measuring the breaking elongation will be described later.

The surface resistivity (ρs) of the resin film can be set to any appropriate value depending on the application. When the resin composition contains a conductive polymer, the surface resistivity (ρs) of the resin film is, for example, 1 × 10 ⁸ Ω / □ to 1 × 10 ¹² Ω / □, and preferably 1 × 10 ^9. Ω / □ to 1 × 10 ¹² Ω / □. The volume resistivity of the seamless belt is, for example, 1 × 10 ⁸ Ω · cm to 1 × 10 ¹² Ω · cm, preferably 1 × 10 ⁹ Ω · cm to 1 × 10 ¹² Ω · cm. .

C. Seamless belt The seamless belt of the present invention includes the resin film. According to the present invention, a resin film having excellent mechanical properties can be provided. Therefore, the resin film of the present invention can be used particularly suitably for applications that require excellent mechanical properties. Therefore, the seamless belt of the present invention can be suitably used for applications requiring excellent mechanical properties such as seamless belts for printing presses and the like. The seamless belt of the present invention may include any other layer other than the resin film, depending on the application.

  Examples of the optional other layer include a thin layer of an inorganic metal oxide for imparting abrasion resistance, or a layer containing a fluororesin powder or a ceramic powder for adjusting slipperiness. Moreover, when using a seamless belt as a release belt, the release layer which consists of a fluororesin or silicone rubber etc. is mentioned.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all.

[Example 1]
A polyester polyol containing a branched structure obtained from adipic acid and 3-methyl-1,5-pentanediol (trade name: P-2010, manufactured by Kuraray Co., Ltd.) in a four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube. Hydroxyl value: 56 mg KOH / g) 31.28 g (0.008 mol), 4,4′-diphenylmethane diisocyanate (MDI) 4.01 g (0.016 mol) and N-methyl-2-pyrrolidone (NMP) 23.52 g. The reaction solution 1 containing the polyester polyol which prepared and stirred under nitrogen stream at 120 degreeC for 3 hours, and modified the hydroxyl group of both ends with diisocyanate was obtained.
To the obtained reaction solution 1, trimellitic anhydride 124.5 g (0.648 mol), 3,3′-dimethylbiphenyl-4,4′-diisocyanate (TODI) 126.85 g (0.48 mol) and MDI 43 .32 g (0.173 mol), diazabicycloundenecene (DBU) 1.52 g (0.01 mol) and NMP 385.86 g were charged, and the temperature was raised to 85 ° C. over 1.5 hours. Next, the temperature was maintained and the reaction was allowed to proceed for 1 hour. Thereafter, NMP was further added so that the solid content concentration was 25% by weight, and reacted at 85 ° C. for 4 hours to obtain a varnish containing a polyamideimide resin.
A resin composition was obtained by adding 0.8211 g (10 mmol) of 2-methylimidazole (2-Mz) to 400 g of varnish containing the polyamideimide resin (solid content: 100 g). The resin composition was applied on a glass substrate, heated at 80 ° C. for 15 minutes and 150 ° C. for 15 minutes, and then cooled to room temperature to form a resin film precursor. After the resin film precursor was peeled from the glass substrate, the resin film precursor was further heated at 200 ° C. for 15 minutes with the ends of the resin film precursor fixed, to obtain a resin film (thickness 80 μm).

[Example 2]
In the same manner as in Example 1, a reaction solution 1 containing a polyester polyol having hydroxyl groups at both ends modified with diisocyanate was obtained.
In the obtained reaction solution 1, trimellitic anhydride 124.5 g (0.648 mol), 3,3′-dimethylbiphenyl-4,4′-diisocyanate (TODI) 126.85 g (0.48 mol) and 4 4,4′-diphenylmethane diisocyanate (MDI) 43.32 g (0.173 mol) and NMP 385.86 g were charged, and the temperature was raised to 140 ° C. over 1.5 hours. Next, the temperature was maintained and the reaction was allowed to proceed for 1 hour. Thereafter, NMP was further added so that the solid content concentration was 20% by weight and reacted at 140 ° C. for 4 hours to obtain a varnish containing a polyamideimide resin.
A resin composition was obtained by adding 0.8211 g (10 mmol) of 2-methylimidazole (2-Mz) to 500 g of varnish containing the polyamideimide resin (solid content: 100 g). The resin composition was applied on a glass substrate, heated at 80 ° C. for 15 minutes and 150 ° C. for 15 minutes, and then cooled to room temperature to form a resin film precursor. After the resin film precursor was peeled from the glass substrate, the resin film precursor was further heated at 200 ° C. for 15 minutes with the ends of the resin film precursor fixed, to obtain a resin film (thickness 80 μm).

[Example 3]
A resin film (thickness 80 μm) was obtained in the same manner as in Example 2 except that the amount of 2-methylimidazole added was 0.4105 g (5 mmol).

[Example 4]
A resin film (thickness 80 μm) was obtained in the same manner as in Example 2 except that the amount of 2-methylimidazole added was 1.642 g (20 mmol).

[Example 5]
A resin film (thickness: 80 μm) was obtained in the same manner as in Example 2 except that the amount of 2-methylimidazole added was 3.284 g (40 mmol).

[Example 6]
Resin film (thickness: 80 μm) in the same manner as in Example 2 except that 1.142 g (10 mmol) of 2-phenylimidazole (2-Pz) was used instead of 0.8211 g (10 mmol) of 2-methylimidazole. Got.

[Example 7]
A resin film (thickness 80 μm) was obtained in the same manner as in Example 5 except that the amount of 2-phenylimidazole added was 0.5709 g (5 mmol).

[Example 8]
A resin film (thickness 80 μm) was obtained in the same manner as in Example 4 except that the amount of 2-phenylimidazole added was 2.284 g (20 mmol).

[Comparative Example 1]
A resin film (thickness 80 μm) was obtained in the same manner as in Example 1 except that 2-methylimidazole was not added.

[Comparative Example 2]
A resin film (thickness 80 μm) was obtained in the same manner as in Example 2 except that 2-methylimidazole was not added.

[Evaluation]
The resin films obtained in Examples 1 to 8 and Comparative Examples 1 and 2 were subjected to the following evaluation. The results are shown in Table 1.
(1) Tensile elastic modulus, breaking strength, breaking elongation The obtained film was punched with dumbbell No. 3 and used as a test piece. Using a Tensilon universal testing machine (manufactured by Toyo Baldwin), the tensile modulus, breaking strength, and breaking elongation were measured at a tensile speed of 100 mm / min.
(2) Folding resistance A 15 mm × 110 mm test piece was cut out from the obtained resin film. Using a tester industry folding resistance tester, the folding strength (MIT folding strength) was evaluated according to JIS-P8115 (2001) (load: 9.8 N). The number of times until the test piece broke after the start of the test was defined as the number of folding times.
(3) Amount of intermolecular imide bond (i) FT-IR apparatus, more specifically, using an FT-IR apparatus (Perkin Elmer, trade name: Spectrum One) equipped with a one-time reflection ATR accessory, The absorption spectrum of the obtained resin film was measured. At the time of measurement, a sample was placed so as to cover the Ge crystal of the ATR accessory. The number is ^measured, 4000cm ^{-1 ~650cm -1,} wavenumber resolution ^{4 cm -1,} the number of integrations was 8 times. Using the obtained absorption spectrum, the amount of intermolecular imide bond was determined by the following method.
(Ii) MDI component peak intensity (peak area) from the benzene ring C = C bond peak (1563～1505Cm around ^-1) and TODI component from the benzene ring of the C = C bond peak (1497～1465Cm around ^-1 ) Peak intensity (peak area) was determined as peak intensity B (peak area).
(Iii) The peak intensity I ₁ (peak area) of the peak (near 1780 cm ⁻¹ ) derived from the C═O bond of the imide bond (intramolecular imide bond) constituting the molecular chain of the polyamideimide resin was determined.
(Iii) the total imide bonds in the resin film (i.e., the sum of the intramolecular imide bond and intermolecular imide bond) was calculated and the peak intensity _{I a} of C = O bonds derived peak (1380 cm around ^-1).
(Iv) The ratio of the peak intensity I _{1 to} the peak intensity B was defined as the amount of intramolecular imide bond.
The (v) the ratio of the peak intensity I _a to the peak intensity B, and the amount of total imide bond in the resin film.
(Vi) (amount of total imide bond) − (amount of intramolecular imide bond), that is, a value calculated from (peak intensity I _a / peak intensity B) − (peak intensity I ₁ / peak intensity B), It was set as the amount of intermolecular imide bonds.

  As is clear from Table 1, the resin composition of the present invention can form a resin film that is excellent in the balance of mechanical properties and particularly excellent in folding resistance. Such an effect becomes more remarkable by appropriately setting the content ratio of the imidazole compound.

  The resin composition of the present invention can provide a film having excellent mechanical properties. Therefore, it can be particularly suitably used for a seamless belt represented by an intermediate transfer belt, a fixing belt, a conveying belt, etc. used in a copying machine or the like that requires excellent mechanical characteristics.

Claims (11)

  A resin composition comprising a polyamideimide resin and an imidazole compound.   The resin composition according to claim 1, wherein the imidazole compound has a boiling point of 200 ° C. or higher. The resin composition according to claim 1 or 2, wherein the polyamideimide resin is obtained by reacting the following (a) and (b-1) to (b-3):
(A) Tricarboxylic acid anhydride (b-1) 3,3′-dimethylbiphenyl-4,4′-diisocyanate (b-2) Polyols whose terminal hydroxyl groups are modified with diisocyanate (b-3) Other than (b-1) Aromatic diisocyanates   The resin composition according to any one of claims 1 to 3, wherein the polyamide-imide resin is a polyamide-imide resin polymerized using a cyclic amine as a catalyst.   The resin composition according to claim 3 or 4, wherein the polyol obtained by modifying the terminal hydroxyl group with a diisocyanate is obtained by reacting a polyester polyol containing a branched structure with a diisocyanate.   The resin composition according to claim 1, further comprising a conductive polymer.   The resin composition according to claim 6, wherein the conductive polymer is conductive polyaniline.   A resin film obtained using the resin composition according to claim 1 and comprising a polyamideimide resin and an imidazole compound.   A seamless belt comprising the resin film according to claim 8. A step of reacting an acid component with a diisocyanate component to obtain a polyamideimide resin;
Mixing the polyamideimide resin and an imidazole compound to prepare a resin composition;
And a step of performing a heat treatment after applying the resin composition to a substrate.
A method for producing a resin film. The method for producing a resin film according to claim 10, wherein a cyclic amine is used as a catalyst in the step of obtaining a polyamideimide resin by reacting an acid component containing the tricarboxylic acid anhydride with a diisocyanate component.