JP2013216856A - Polyamideimide resin, and resin composition, resin film and seamless belt using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamideimide resin capable of being fabricated into a film holding a sufficient elasticity and further excellent in other mechanical properties.SOLUTION: A polyamideimide resin composition is obtained by reacting (A) an acid component containing a tricarboxylic anhydride, and (B) a polyisocyanate component, wherein the polyisocyanate component (B) contains (b-1) an isocyanate compound obtained by modifying both terminal hydroxyl groups of a polyester polyol with a diisocyanate, and (b-2) an aromatic diisocyanate.

Description

  The present invention relates to a polyamideimide resin. More specifically, a polyamideimide resin that can provide a resin film that retains sufficient elasticity and is excellent in other mechanical properties (for example, breaking strength and breaking elongation), and a resin using the polyamideimide resin The present invention relates to a composition, a resin film, and a seamless belt.

  The polyamideimide resin is a resin having an amide bond and an imide bond in the molecular skeleton. As a method for synthesizing a polyamideimide resin, an acid chloride method in which trimellitic anhydride chloride and diamine are reacted, an isocyanate method in which trimellitic anhydride and diisocyanate are reacted, and trimellitic anhydride and diamine are reacted. Direct polymerization methods are known. Among them, from the viewpoint of productivity, an isocyanate method using trimellitic anhydride and diisocyanate is often used (for example, Patent Document 1 and Patent Document 2).

  As the polyamide-imide resin obtained by the isocyanate method, a polyamide-imide resin obtained from trimellitic anhydride and 4,4′-diphenylmethane diisocyanate is widely used for coatings and the like. However, the polyamide-imide resin composed of these components has insufficient mechanical properties to be used as a seamless belt, and has not been put into practical use.

  Among the above-mentioned mechanical properties, as a polyamideimide resin with improved tensile strength and elongation rate, a polyamideimide resin using a compound obtained by reacting both hydroxyl groups of carbonate diol with diisocyanate as a diisocyanate has been proposed (for example, Patent Documents). 3). However, with this method, the tensile modulus of the resulting polyamideimide resin may decrease. In addition, as a resin that provides a cured film having excellent flexibility, a silane-modified polyamideimide resin (Patent Document 4) using a polyisocyanate obtained by reacting a polymer polyol and a diisocyanate, or a polymer polyol of a dibasic acid is used. A modified polyamideimide resin using a carboxylic acid-terminated polymer reacted with an anhydride (Patent Document 5) has been proposed. Although these resin compositions are excellent in flexibility, there is room for improvement in other mechanical properties. Thus, in a film using a polyamideimide resin, it is difficult to achieve both sufficient elasticity and other mechanical properties.

JP-A-4-34912 JP-A-1-284555 JP 2007-16097 A JP-A-2005-146180 JP 2006-231689 A

  An object of the present invention is to provide a polyamide-imide resin that can provide a resin film that retains sufficient elasticity and is excellent in other mechanical properties (for example, breaking strength and breaking elongation).

  As a result of intensive studies, the present inventors have found that the above object can be achieved by the polyamideimide resin shown below, and have completed the present invention.

The polyamideimide resin of the present invention is obtained by reacting (A) an acid component containing a tricarboxylic acid anhydride and (B) a polyisocyanate component. The polyisocyanate component (B) includes (b-1) an isocyanate compound obtained by modifying both terminal hydroxyl groups of a polyester polyol with diisocyanate, and (b-2) an aromatic diisocyanate.
In preferable embodiment, the molar ratio of the isocyanate compound (b-1) which modified | denatured the both terminal hydroxyl group of the said polyester polyol with diisocyanate with respect to the said polyisocyanate component (B) is 0.01-0.2.
In a preferred embodiment, the polyester polyol includes a branched structure.
According to another aspect of the present invention, a resin composition is provided. This resin composition contains the polyamideimide resin.
In a preferred embodiment, the resin composition further includes a conductive filler.
According to still another aspect of the present invention, a resin film is provided. This resin film is obtained by the resin composition.
According to still another aspect of the present invention, a seamless belt is provided. This seamless belt includes the resin film.

  The polyamideimide resin of the present invention contains an isocyanate compound obtained by modifying both terminal hydroxyl groups of a polyester polyol with diisocyanate as a polyisocyanate component. Thereby, the film using the obtained polyamide-imide resin retains sufficient elasticity and is excellent in other mechanical properties (for example, breaking strength and breaking elongation). Moreover, the mechanical characteristic of the film using the obtained polyamide imide resin further improves by using the polyester polyol containing a branched structure as said polyester polyol. The polyamide-imide resin of the present invention can be particularly suitably used for seamless belt applications such as printing presses that require mechanical strength.

<A. Polyamideimide resin>
The polyamideimide resin of the present invention is obtained by reacting (A) an acid component containing a tricarboxylic acid anhydride and (B) a polyisocyanate component. The polyisocyanate component (B) comprises an isocyanate compound (b-1) obtained by modifying both terminal hydroxyl groups of a polyester polyol with diisocyanate (hereinafter also referred to as isocyanate compound (b-1)) and an aromatic diisocyanate (b-2). Including. The method for synthesizing the polyamide-imide resin of the present invention is preferably the isocyanate method because of its excellent work efficiency.

  The mixing ratio of the acid component (A) and the polyisocyanate component (B) used for the synthesis of the polyamideimide resin of the present invention is preferably 0.8 to 1.4, more preferably 0.9 to 1 in terms of equivalent ratio. .3, and more preferably 0.9 to 1.2.

  The number average molecular weight of the polyamideimide resin of the present invention is preferably 5,000 to 50,000, more preferably 10,000 to 40,000, and further preferably 15,000 to 35,000. When the number average molecular weight of the polyamideimide resin is outside the above range, it may be difficult to form a film or the mechanical properties of the film obtained using the polyamideimide resin may be significantly deteriorated.

<A-1. Acid component (A)>
The acid component (A) includes 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 (A) 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 (A) is preferably 0.5 to 1.0, more preferably 0.7 to 1.0.

<A-2. Polyisocyanate component (B)>
The polyisocyanate component (B) includes an isocyanate compound (b-1) obtained by modifying both terminal hydroxyl groups of a polyester polyol with diisocyanate, and an aromatic diisocyanate (b-2). By using the isocyanate compound (b-1) as the polyisocyanate component (B), it is possible to obtain a polyamideimide resin capable of providing a film having sufficient elasticity and excellent in other mechanical properties. Moreover, the elasticity of the film using the obtained polyamide imide resin can be improved by using aromatic diisocyanate (b-2) as a polyisocyanate component (B).

<A-2-1. Isocyanate compound (b-1) in which both terminal hydroxyl groups of polyester polyol are modified with diisocyanate>
The isocyanate compound (b-1) can be obtained by any appropriate method. For example, it can be obtained by reacting any suitable polyester polyol with any suitable diisocyanate.

  Any appropriate polyester polyol can be used as the polyester polyol. The polyester polyol can be obtained, for example, by condensation polymerization of dicarboxylic acid and diol. The polyester polyol is preferably a polyester polyol containing a branched structure. 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. The said polyester polyol may be used independently and may be used in combination of 2 or more type.

  Only a polyester polyol containing a branched structure is used as a polyester polyol because it is possible to obtain a polyamide-imide resin capable of providing both a higher degree of elasticity and strength and a film with even better mechanical properties. It is preferable to do. 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 providing a film with further excellent mechanical properties can be obtained by using a polyester polyol having a branched structure.

  Moreover, 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.

  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 number average molecular weight of the polyester polyol containing a branched structure (value measured using a standard polystyrene calibration curve by gel permeation chromatography (GPC)) can be set to any appropriate value. The number average molecular weight of the polyester polyol is preferably 500 to 8,000, more preferably 1,000 to 4,000. When the number average molecular weight of the polyester polyol is within the above range, a polyimideimide resin capable of providing a film having sufficient elasticity and excellent in other mechanical properties can be obtained.

  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% to 100% of repeating units containing a branched structure. If the repeating unit containing a branched structure is 50% to 100%, the mechanical properties of the film obtained using the polyamideimide resin of the present invention can be further improved.

  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.

  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.

  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 may be reduced, and it may be difficult to obtain a desired polyamideimide resin. There is a possibility that the adhesiveness of the material will be lowered.

  Arbitrary appropriate diisocyanate can be used as diisocyanate made to react with the said polyester polyol. For example, diphenylmethane diisocyanate, tolylene diisocyanate, tetramethylxylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, aromatic diisocyanates such as naphthalene diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate; isophorone diisocyanate, water Examples include alicyclic diisocyanates such as added xylylene diisocyanate, norbornene diisocyanate, and dicyclohexylmethane diisocyanate. These diisocyanates may be used alone or in combination of two or more.

  The isocyanate compound (b-1) can be obtained, for example, by reacting the polyester polyol with a double molar equivalent of the diisocyanate of the polyester polyol in any appropriate solvent. Any appropriate solvent can be used as the solvent. For example, N-methyl-2-pyrrolidone; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate, butyl acetate and γ-butyrolactone; ether solvents such as diethylene glycol dimethyl ether and triethylene glycol dimethyl ether Cellosolv solvents such as butyl cellosolve acetate, ethyl cellosolve acetate and methyl cellosolve acetate; aromatic hydrocarbon solvents such as toluene, xylene and p-cymene; tetrahydrofuran, dioxane N, N-dimethylformamide, N, N-dimethylacetamide, Examples thereof include dimethyl sulfoxide. The said solvent may be used independently and may be used in combination of 2 or more type.

  The reaction temperature can be set to any appropriate temperature. The reaction temperature can be set to, for example, 100 ° C to 150 ° C. The reaction time can be set to any suitable time depending on the amount of material charged and the batch size. The reaction time can be set to 1 hour to 5 hours, for example.

  The number average molecular weight of the isocyanate compound (b-1) (value measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve) is preferably 500 to 10,000, more preferably. It is 1,000-9,500, More preferably, it is 1,500-9,000. When the number average molecular weight of an isocyanate compound (b-1) is less than 500, there exists a possibility that the breaking elongation of the film containing the obtained polyamide imide resin may fall. When the number average molecular weight of the isocyanate compound (b-1) exceeds 10,000, the reactivity of the diisocyanate is lowered and it is difficult to increase the molecular weight of the polyamideimide resin.

  The molar ratio of the isocyanate compound (b-1) to the polyisocyanate component (B) (isocyanate compound (b-1) / polyisocyanate component (B)) is preferably 0.005 to 0.2, more preferably. Is 0.01 to 0.1. When the molar ratio of the isocyanate compound (b-1) to the polyisocyanate component (B) is less than 0.005, the effect of improving the mechanical properties may not be sufficiently obtained. When the molar ratio of the isocyanate compound (b-1) to the polyisocyanate compound (B) exceeds 0.2, the properties of the polyamideimide resin may not be sufficiently exhibited.

<A-2-2. Aromatic Diisocyanate (b-2)>
Any appropriate aromatic diisocyanate can be used as the aromatic diisocyanate (b-2). Examples thereof include diphenylmethane diisocyanate, tolylene diisocyanate, tetramethylxylene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, naphthalene diisocyanate, and the like. It is preferable that 3,3′-dimethylbiphenyl-4,4′-diisocyanate is included as the aromatic diisocyanate from the viewpoint that the obtained film using the polyamideimide resin has excellent elasticity.

  The molar ratio of aromatic diisocyanate (b-2) to polyisocyanate component (B) (aromatic diisocyanate (b-2) / polyisocyanate component (B)) is preferably 0.8 to 0.995, More preferably, it is 0.900 to 0.990.

  The molar ratio of 3,3′-dimethylbiphenyl-4,4′-diisocyanate to the aromatic diisocyanate (b-2) is preferably 0.3 to 0.9, more preferably 0.5 to 0.00. 8. When the molar ratio of 3,3′-dimethylbiphenyl-4,4′-diisocyanate to aromatic diisocyanate is within the above range, a polyamideimide resin capable of providing a film having sufficient elasticity can be obtained.

<A-2-3. Other polyisocyanate (b-3)>
The polyisocyanate component (B) may contain a polyisocyanate (b-3) other than the isocyanate compound (b-1) and the aromatic diisocyanate (b-2). Arbitrary appropriate polyisocyanate can be used as said other polyisocyanate (b-3). Examples include aliphatic isocyanates such as hexamethylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, norbornene diisocyanate, and dicyclohexylmethane diisocyanate. Said other polyisocyanate (b-3) may be used independently and may be used in combination of 2 or more type.

  The polyamideimide resin of the present invention can be obtained by reacting the acid component (A) and the polyisocyanate component (B) in any appropriate solvent. The reaction of the acid component (A) and the polyisocyanate component (B) may be performed continuously with the reaction of the isocyanate compound (b-1), or the reaction may be performed by adding each material.

  Any appropriate solvent can be used as the solvent, and examples thereof include N-methyl-2-pyrrolidinone, N, N-dimethylacetamide, and γ-butyrolactone. These solvents may be used alone or in combination of two or more.

  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 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.

  What is necessary is just to set suitably about reaction temperature and reaction time. 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.

<B. Resin composition>
The resin composition of the present invention contains the polyamideimide resin. The polyamide-imide resin of the present invention can provide a film having sufficient elasticity and excellent in other mechanical properties. Therefore, the resin composition of the present invention may contain any appropriate additive depending on the use of the obtained film. For example, when a seamless belt used as an intermediate transfer belt is produced using the resin composition of the present invention, a conductive filler may be further included in order to impart semiconductivity.

  The resin composition of the present invention preferably further contains a conductive filler. When the resin composition contains a conductive filler, desired electrical characteristics can be imparted to a film obtained using the resin composition. Any appropriate conductive filler can be used as the conductive filler. Examples thereof include inorganic compounds such as carbon black, aluminum, nickel, tin oxide, and potassium titanate, and conductive polymers such as polyaniline and polypyrrole. When preparing a resin composition used for production of an intermediate transfer belt, the conductive filler is preferably carbon black or polyaniline. Polyaniline is less likely to adversely affect the original mechanical properties of the substrate than carbon black, and variation in electrical resistance is less likely to occur. Furthermore, it is particularly preferable to use polyaniline as a conductive filler from the viewpoint that good electrical characteristics can be imparted with a relatively small addition amount and that it can be uniformly dispersed in a polyamideimide resin.

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

  The solid content of the resin composition can be appropriately set according to the method for producing the film. The solid content of the resin composition can be set to 15 wt% to 35 wt%, for example.

  The solid content of the resin composition can be adjusted by adding any appropriate organic solvent to the reaction solution of the polyamideimide resin. Moreover, after removing the solvent used for the reaction from the reaction solution of the polyamideimide resin, any appropriate solvent may be added to adjust the solid content. As said organic solvent, the solvent used for reaction of a polyamideimide resin can be used, for example. Preferably, the solid content of the resin composition can be adjusted using the solvent used for the reaction of the polyamideimide resin.

<C. Resin film>
The resin film of the present invention contains the polyamideimide resin. Therefore, the resin film of the present invention retains sufficient elasticity and is excellent in other mechanical properties. Since the resin film of this invention is excellent in mechanical strength, it can be used for various uses. 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.

  The thickness of the resin film of this invention can be suitably set according to a use etc. The thickness of the resin film of the present invention is, for example, 25 μm to 150 μm, preferably 50 μm to 100 μm.

  The resin film of the present invention can be obtained by applying the resin composition to any appropriate substrate to prepare a coating film, removing the solvent from the coating film, and drying. As said base material, glass, a metal, a polymer film etc. are mentioned, for example. Any appropriate method can be used as a method of applying the resin composition to the substrate.

  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. The heat treatment time is preferably 10 minutes to 60 minutes.

<D. Seamless belt>
The seamless belt of the present invention includes the resin film. The polyamide-imide resin of the present invention can provide a resin film having excellent mechanical properties. Therefore, the film obtained by using the polyamideimide resin of the present invention can be particularly suitably used for applications requiring 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.

  The thickness of the seamless belt can be appropriately set depending on the application, and is usually 50 μm to 150 μm, more preferably 60 μm to 100 μm.

When the seamless belt of the present invention is obtained using the resin composition containing a conductive filler, the surface resistivity of the seamless belt is, for example, 1 × 10 ⁸ Ω / □ to 1 × 10 ¹² Ω / □, Preferably, it is 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. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. In addition, a part means a weight part.

[Example 1]
Into a four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube, a polyester polyol containing no branched structure consisting of adipic acid and hexanediol (manufactured by DIC, trade name: OD-X-2640, hydroxyl value: 58 mgKOH / g) 393.7 parts (0.20 mol) and 4,4′-diphenylmethane diisocyanate (MDI) (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Millionate MT, number average molecular weight: 250.46) 100.2 parts (0 .40 mol) and 329.3 parts of N-methyl-2-pyrrolidone (NMP), a reaction solution containing a polyester polyol in which the hydroxyl groups at both ends are modified with diisocyanate by heating and stirring at 120 ° C. for 3 hours under a nitrogen stream. 1 was obtained.
To the obtained reaction solution 1, 807.0 parts (4.20 mol) of trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Inc., number average molecular weight: 192.13) and 3,3′-dimethylbiphenyl-4,4 ′ -Diisocyanate (TODI) (Nippon Soda Co., Ltd., trade name: TODI, number average molecular weight: 250.46) 792.8 parts (3.00 moles), MDI 271.5 parts (1.08 moles) and NMP 2664.0 parts And heated up to 140 ° C. over 1.5 hours. Next, the temperature was maintained and reacted for 3 hours as it was to obtain a polyamideimide resin.

[Example 2]
Instead of a polyester polyol having no branched structure composed of adipic acid and hexanediol, a polyester polyol having a branched structure composed of adipic acid and 3-methyl-1,5-pentadiol (trade name: P-2010, manufactured by Kuraray Co., Ltd.) , Hydroxyl value: 56 mg KOH / g, number average molecular weight: 2000) was used in the same manner as in Example 1 except that 401.43 parts (0.20 mol) was used and that the amount of NMP charged was 334.4 parts. Thus, a reaction solution 2 containing a polyester polyol having hydroxyl groups at both ends modified with diisocyanate was obtained.
A polyamideimide resin was obtained in the same manner as in Example 1 except that the obtained reaction solution 2 was used.

[Example 3]
The amount of polyester polyol P-2010 containing a branched structure is 20.72 parts (0.10 mol), the amount of MDI is 150.1 parts (0.20 mol), and the amount of NMP is 167.2. A reaction solution 3 containing a polyester polyol in which the hydroxyl groups at both ends were modified with diisocyanate was obtained in the same manner as in Example 2 except that the parts were used.
Implemented except that the obtained reaction solution 3 was used, and that the amount of trimellitic anhydride charged was changed to 787.7 parts (4.10 mol) and the amount of NMP charged was changed to 2445.0 parts. A polyamideimide resin was obtained in the same manner as in Example 1.

[Example 4]
Instead of the polyester polyol having a branched structure having a number average molecular weight of 2000, a polyester polyol having a branched structure having a number average molecular weight of 1000 (manufactured by Kuraray Co., Ltd., trade name: P-1010, hydroxyl value: 114.9 mgKOH / g) ) Was used at 187.5 parts (0.19 mole), the MDI charge was 96.2 parts (0.38 mole), and the NMP charge was 189.1 parts. In the same manner as in Example 1, a reaction solution 4 containing a polyester polyol having hydroxyl groups at both ends modified with diisocyanate was obtained.
The obtained reaction solution 4 was used, the trimellitic anhydride charge was 805.4 parts (4.19 mol), and the TODI charge was 792.8 parts (3.00 mol). A polyamideimide resin was obtained in the same manner as in Example 1 except that the amount of MDI charged was changed to 271.5 parts (1.08 mol) and the amount of NMP charged was changed to 2487.5 parts.

[Example 5]
375.0 parts (0.38 mol) of a charged amount of a polyester polyol having a branched structure having a number average molecular weight of 1000 (manufactured by Kuraray Co., Ltd., trade name: P-1010, hydroxyl value: 114.9 mgKOH / g), The hydroxyl groups at both ends were modified with diisocyanate in the same manner as in Example 1 except that the amount of MDI charged was changed to 192.4 parts (0.77 mol) and the amount of NMP charged was changed to 378.22 parts. A reaction solution 5 containing a polyester polyol was obtained.
Using the obtained reaction solution 5, the amount of trimellitic anhydride charged to 842.3 parts (4.38 mol), and the amount of TODI charged to 792.8 parts (3.00 mol), A polyamideimide resin was obtained in the same manner as in Example 1 except that the amount of MDI charged was changed to 272.4 parts (1.09 mol) and the amount of NMP charged was changed to 2755.3 parts.

[Example 6]
Instead of the polyester polyol having a branched structure having a number average molecular weight of 2000, a polyester polyol having a branched structure having a number average molecular weight of 4000 (manufactured by Kuraray Co., Ltd., trade name: P-4010, hydroxyl value: 28.7 mgKOH / g) ) 195.5 parts (0.05 mol), and the MDI charge was changed to 25.1 parts (0.10 mol) and the NMP charge was changed to 147.0 parts. In the same manner as in Example 1, a reaction solution 6 containing a polyester polyol in which the hydroxyl groups at both ends were modified with diisocyanate was obtained.
The obtained reaction solution 6 was used, and the amount of trimellitic anhydride charged was 778.1 parts (4.05 mol), and the amount of TODI was 792.8 parts (3.00 mol). A polyamideimide resin was obtained in the same manner as in Example 1 except that the amount of MDI charged was changed to 270.8 parts (1.08 mol) and the amount of NMP charged was changed to 2411.6 parts.

[Example 7]
390.9 parts (0.10 mol) of a charged amount of a polyester polyol having a branched structure having a number average molecular weight of 4000 (manufactured by Kuraray Co., Ltd., trade name: P-4010, hydroxyl value: 28.7 mgKOH / g), The hydroxyl groups at both ends were modified with diisocyanate in the same manner as in Example 1, except that the amount of MDI charged was changed to 50.1 parts (0.20 mol) and the amount of NMP charged was changed to 294.0 parts. A reaction solution 7 containing a polyester polyol was obtained.
Using the obtained reaction solution 7, the amount of trimellitic anhydride charged to 787.7 parts (4.10 mol), and the amount of TODI charged to 792.8 parts (3.00 mol), A polyamideimide resin was obtained in the same manner as in Example 1 except that the amount of MDI charged was changed to 271.0 parts (1.08 mol) and the amount of NMP charged was changed to 2603.6 parts.

(Comparative Example 1)
A four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube was charged with 1152.8 parts (6.00 mol) of trimellitic anhydride, 1502.8 parts (6.00 mol) of MDI, and 2445 parts of NMP. It heated up to 1.5 degreeC over 1.5 hours. Next, the temperature was maintained and reacted for 3 hours as it was to obtain a polyamideimide resin.

(Comparative Example 2)
To a four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube, 416.3 parts (0,6 hexanediol-based polycarbonate polyol (trade name: CD220, hydroxyl value: 54 mgKOH / g, manufactured by Daicel Chemical Industries, Ltd.)) .20 moles), 100.2 parts (0.40 moles) of MDI and 344.3 parts of NMP, a mixture of polycarbonate polyol in which the hydroxyl groups at both ends are modified with diisocyanate by heating and stirring at 120 ° C. for 3 hours under a nitrogen stream. Solution c1 was obtained.
A polyamideimide resin was obtained in the same manner as in Example 1 except that the obtained reaction solution c1 was used and that the amount of NMP charged was 2682.8 parts.

(Comparative Example 3)
Polycarbonate polyol Compared to CD220, except that the charge amount was 732.7 parts (0.35 mol), the MDI charge amount was 176.3 parts (0.70 mol), and the NMP charge amount was 606.0 parts. In the same manner as in Example 2, a reaction solution c2 containing a polycarbonate polyol in which the hydroxyl groups at both ends were modified with diisocyanate was obtained.
In the obtained reaction solution c2, trimellitic anhydride 682.5 parts (3.55 mol), TODI 634.3 parts (2.40 mol), MDI 218.7 parts (0.87 mol), NMP 2590.9 parts, And heated up to 140 ° C. over 1.5 hours. Next, the temperature was maintained and reacted for 8 hours as it was to obtain a polyamideimide resin.

[Evaluation]
NMP was added to the reaction solution containing the polyamideimide resin obtained in Examples 1 to 7 and Comparative Examples 1 to 3, and the solid content was adjusted to 25% by weight. The adjusted solution was applied on a glass substrate. The coated glass substrate was heated in a high temperature bath at 80 ° C. for 15 minutes and 150 ° C. for 15 minutes, and cooled to room temperature. Subsequently, the film was released from the glass substrate to obtain a self-supporting film having a thickness of 80 μm. The edge part of the film containing the obtained polyamideimide resin of Examples 1-7 and Comparative Examples 1-2 was fixed, and it heated further at 240 degreeC for 15 minute (s), and obtained the polyamideimide film. The film containing the polyamideimide resin of Comparative Example 3 fixed the end of the film and further heated at 200 ° C. for 30 minutes to obtain a polyamideimide film.
The following evaluation was performed using the obtained polyamideimide film. 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 m / min. If the tensile modulus is 2500 MPa or more, it has sufficient elasticity. If the breaking strength is 150 MPa or more, it has sufficient strength. If the elongation at break is 30% or more, it has sufficient flexibility.

  As is clear from Table 1, the films using the polyamideimide resins of Examples 1 to 7 retained a sufficient tensile elastic modulus and had excellent breaking strength and breaking elongation. Moreover, in the film using the polyamide imide resin of Examples 2-7 using the polyester polyol containing a branched structure, the tensile elasticity modulus improved further and the film which has the further outstanding mechanical strength was obtained. Especially, in the film using the polyamideimide resin of Examples 2, 3, 4 and 6, the breaking strength was further improved, and a film having very excellent mechanical strength was obtained.

  The polyamide film of Comparative Example 1 had a low tensile modulus and breaking strength, and the mechanical strength was insufficient for use in a seamless tubular body such as a copying machine. Further, Comparative Example 2 using polycarbonate polyol had insufficient breaking strength and breaking elongation, and Comparative Example 3 had insufficient breaking strength and tensile elastic modulus.

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

Claims (7)

(A) a polyamide-imide resin obtained by reacting an acid component containing a tricarboxylic acid anhydride and (B) a polyisocyanate component,
Polyamideimide resin in which the polyisocyanate component (B) includes (b-1) an isocyanate compound in which both terminal hydroxyl groups of the polyester polyol are modified with diisocyanate, and (b-2) an aromatic diisocyanate.   The polyamide-imide resin according to claim 1, wherein the molar ratio of the isocyanate compound (b-1) obtained by modifying both terminal hydroxyl groups of the polyester polyol with diisocyanate with respect to the polyisocyanate component (B) is 0.01 to 0.2. .   The polyamide-imide resin according to claim 1, wherein the polyester polyol includes a branched structure.   A resin composition comprising the polyamideimide resin according to claim 1.   The resin composition according to claim 4, further comprising a conductive filler.   A resin film obtained using the resin composition according to claim 4.   A seamless belt using the resin film according to claim 6.