Polyamideimide

Abstract

To provide a polyamide-imide (PAI) capable of obtaining a polyamide-imide film having both high elastic modulus and high elongation when molding into a film shape.SOLUTION: A polyamide-imide (PAI) is a polyamide-imide (PAI) using trimellitic anhydride (TMA) as an acid constituent, o-tolidinediisocyanate (TODI) as an isocyanate constituent, and dimer diamine (DDA) as a diamine constituent, where the tensile strength is 60% or more, and the tensile elastic modulus is 4.5 GPa or more when turned into a film.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to polyamideimide (PAI) which is formed into a film shape and is suitably used as an intermediate transfer belt, a fixing belt, etc. of a copying machine, a printer, etc.

Background Art

[0002] As an intermediate transfer belt and a fixing belt of a copying machine and a printer that require high speed, films made of polyimide-based materials such as PAI having excellent heat resistance, mechanical properties, and dimensional stability are widely used. These belts can be obtained, for example, by applying a solution containing PAI to a mold and drying it, and are usually used as seamless belts made of a PAI film with a thickness of 30 μm to 150 μm.

[0003] As a PAI film used for these belts, a film made of PAI using trimellitic acid (TMA) as an acid component and o-tolidine diisocyanate (TODI) as an isocyanate component is known. Patent Documents 1 to ⑧ disclose that a PAI belt made of a PAI film having such a chemical structure is excellent in dimensional stability, heat resistance, and mechanical properties (especially rigidity).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

[0005] However, a belt made of PAI using trimellitic anhydride (TMA) as the acid component and tolylene-2,4-diisocyanate (TODI) as the isocyanate component described in the above patent documents has insufficient toughness as a belt, that is, insufficient elongation when formed into a film. When the belt was attached to a copying machine and used for a long time, breakage or cracking sometimes occurred. For this reason, as PAI used as a belt for a copying machine, in addition to having a high elastic modulus (rigidity) when formed into a film, it has been required to have a high elongation. That is, there has been a need for PAI that can achieve both a high elastic modulus and a high elongation, which are in a trade-off relationship.

[0006] Therefore, the present invention solves the above problems, and an object thereof is to provide a PAI capable of obtaining a PAI film having both a high elastic modulus and a high elongation when formed into a film shape. [Means for Solving the Problems]

[0007] As a result of intensive studies to solve the above problems, it has been found that by using a novel PAI having a specific chemical structure and having specific mechanical properties when formed into a film, the above problems can be solved, and the present invention has been completed.

[0008] The present invention is directed to "PAI using trimellitic anhydride (TMA) as the acid component, o-tolidine diisocyanate (TODI) as the isocyanate component, and dimer diamine (DDA) as the diamine component, characterized in that the tensile elongation when formed into a film is 60% or more and the tensile elastic modulus is 4.5 GPa or more".

Advantages of the Invention

[0009] By forming the PAI of the present invention into a film shape, a PAI film having both a high elastic modulus and a high elongation can be obtained. Therefore, the PAI belt made of this PAI film can be suitably used as an intermediate transfer belt or a fixing belt for a copying machine or a printer.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail.

[0011] The PAI of the present invention can be obtained as a solution, for example, by the following method. That is, first, in a solvent, a part of TMA and DDA are reacted to obtain a mixture composed of TMA and diimidodicarboxylic acid formed from a part of TMA and DDA. Then, without isolating this mixture, a solution containing the PAI of the present invention can be obtained by subjecting it to a polymerization reaction with TODI. The molar ratio of TMA to the total of TODI and DDA is preferably substantially equimolar, that is, TMA / (TODI + DDA)=1 / 0.95 to 1.05 (molar ratio). Here, the amount of DDA used is 、 1 mol% or more and 8 mol% or less is necessary . By setting the amount of DDA used within such a range, it is possible to achieve both mechanical property values in a trade-off relationship of high elongation and high elastic modulus. Here, DDA is an aliphatic diamine derived from a dimer acid having 24 to 48 carbon atoms, and commercially available products such as "Versamine 551" and "Versamine 552" manufactured by Cognis Japan Co., Ltd. and "Priamine 1074" and "Priamine 1075" manufactured by Croda Co., Ltd. can be used. Note that since the PAI composed only of TMA, TODI, and DDA tends to be insoluble in the reaction solvent, 10 to 60 mol% of TODI can be replaced with methylene diphenyl diisocyanate (MDI) and / or toluene diisocyanate (TDI).is necessary . Also, part of the TMA may be substituted with other acid components. Specifically, if it is 10 mol% or less of TMA, it may be substituted with pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, etc. If this substitution rate exceeds 10 mol%, it may be difficult to achieve both mechanical property values.

[0012] In the polymerization reaction, it is preferable to blend 0.01 to 1 mol% of a basic compound such as 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), triethylenediamine (DABCO), or triethylamine as a catalyst with respect to TMA. By using such a basic catalyst, a PAI with an even higher degree of polymerization can be obtained. Although these basic catalysts are known as polymerization catalysts in PAI polymerization, they are specifically effective in the polymerization reaction of PAI composed of TMA, TODI, and DDA.

[0013] There is no limitation on the solvent used in the above-described diimide dicarboxylic acid formation reaction and polymerization reaction, but it is preferable to use an amide-based solvent. Specific examples of the amide-based solvent include N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), etc. These solvents can be used alone or as a mixture. Among these, NMP, DMAc, and their mixtures are preferable. It is preferable that the water content of these polymerization solvents is dehydrated to 100 ppm or less.

[0014] When carrying out the diimide dicarboxylic acid formation reaction and the polymerization reaction, the reaction temperature is preferably 100 to 200 °C, more preferably 120 to 180 °C. In this reaction, the order of adding the monomer and the solvent is not particularly limited, and any order may be used. When producing diimide dicarboxylic acid by the reaction of TMA and DDA, it is preferable to proceed the reaction while removing water, which is a by-product during imidization, outside the reaction system.

[0015] The solution containing the PAI of the present invention obtained as described above preferably has a solution viscosity of 10 Pa·s or more and 200 Pa·s or less, and more preferably 80 Pa·s or more and 150 Pa·s or less. Here, the solution viscosity can be confirmed by measuring the rotational viscosity at 30 °C using a DVL-BII type digital viscometer (B-type viscometer) manufactured by Tokimec.

[0016] The concentration of the solution containing the PAI of the present invention is preferably more than 10% by mass and less than 25% by mass, and more preferably 16% by mass or more and 22% by mass or less.

[0017] The solution containing the PAI of the present invention obtained as described above can be made into a film composed of the PAI of the present invention by coating and drying on a substrate. There is no limitation on the substrate to be used, but metal foils such as copper foils and organic polymer films such as polyester films and polyimide films can be preferably used. Further, the solution containing the PAI of the present invention can be made into a seamless belt composed of a PAI film by coating it on a cylindrical mold, drying it, and then demolding it. In addition, as the drying conditions when obtaining a film from the PAI solution, it is preferable to pre-dry at a temperature of 50 to 180 °C and then set it at 200 to 300 °C. Also, there is no limitation on the thickness of the formed PAI film, but it is usually about 1 to 200 μm.

[0018] The PAI of the present invention needs to have a tensile elongation of 60% or more and a tensile modulus of elasticity of 4.5 GPa or more when formed into a film, and more preferably a tensile elongation of 70% or more and a tensile modulus of elasticity of 5.0 GPa or more. By doing so, for example, it can be used as a belt for a copying machine in which rigidity and toughness are both achieved. Note that the tensile modulus of elasticity and the tensile elongation of the PAI film can be confirmed by measuring in accordance with JIS K7127:1999.

Examples

[0019] Hereinafter, the present invention will be specifically described based on examples, but it is not limited by these examples.

[0020] <Example 1> Into a glass reaction vessel, under a nitrogen atmosphere, 1.000 mol of TMA and 0.015 mol of DDA (manufactured by Clariant Japan, "PRIAMINE1075") were charged together with dehydrated NMP (water content rate 80 ppm) so that the solid content concentration became 10% by mass. While stirring, the temperature was raised to 180°C, and a nitrogen gas stream was circulated through the reaction system to remove the water generated by the reaction outside the system, and the reaction was carried out at 180°C for 5 hours to obtain a TMA solution containing diimidodicarboxylic acid, which is a reaction product of TMA and DDA. Thereafter, this solution was returned to room temperature, 0.82 mol of TODI, 0.20 mol of MDI, and 0.0005 mol of DABCO were added, and after reacting at 160°C for 5 hours, the reaction solution was diluted with NMP to obtain a PAI solution having a solid content concentration of 18% by mass and a viscosity of 115 Pa·s based on the above-described measurement method. Next, the obtained PAI solution was applied onto a polyester film, dried at 80°C for 10 minutes and then at 130°C for 10 minutes, and then the coating film was peeled off from the polyester film. Thereafter, this coating film was sandwiched between metal frames and dried at 290°C for 60 minutes under a nitrogen gas atmosphere to obtain a PAI film having a thickness of 40 μm. Table 1 shows the results of measuring the tensile modulus of elasticity and the tensile elongation of the PAI film by the method based on the above-described JIS.

[0021] <Example 2~4、 6> A PAI film was obtained in the same manner as in Example 1, except that the compositions of the isocyanate component and the diamine component were as shown in Table 1. The results of measuring the film properties are shown in Table 1.

[0022] <Comparative Examples 1 and 2> A PAI film was obtained in the same manner as in Example 1, except that the compositions of the isocyanate component and the diamine component were as shown in Table 1. The results of measuring the film properties are shown in Table 1.

[0023]

Table 1

[0024] As shown in the examples, a PAI film having both a high elastic modulus and a high elongation can be obtained from the PAI of the present invention.

Industrial Applicability

[0025] The film made of the PAI of the present invention can be suitably used as a seamless PAI belt, an intermediate transfer belt of a copying machine or a printer, and a fixing belt.

Claims

【Claim 1】 A polyamideimide (PAI) using trimellitic anhydride (TMA) as the acid component, o-tolidine diisocyanate (TODI) as the isocyanate component, and diaminodiamine (DDA) as the diamine component, wherein the amount of DDA used is 1 mol% or more and 8 mol% or less based on the number of moles of TMA, and 10 to 60 mol% of TODI is substituted with methylene diphenyl diisocyanate (MDI) and / or toluene diisocyanate (TDI), and the tensile elongation when formed into a film is 60% or more and the tensile elastic modulus is 4.5 GPa or more. The polyamideimide (PAI) is characterized by the above.

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