KR102618143B1 - polyamideimide - Google Patents

Abstract

The present invention provides PAI that can produce a PAI film having both a high elastic modulus and high elongation when molded into a film. The present invention uses trimellitic anhydride (TMA) and dimer acid (DA) as the acid components and o-tolidine diisocyanate (TODI) as the isocyanate component, and the moles of the sum of TMA and DA are used. Polyamideimide (PAI) in which DA is less than 30 mol% and 10 to 50 mol% of TODI is substituted with methylene diphenyl diisocyanate (MDI) and/or toluene diisocyanate (TDI). It's about.

Description

polyamideimide

The present invention relates to polyamideimide (PAI), which is molded into a film, for example, and is suitably used as an intermediate transfer belt, fixing belt, etc. for copiers, printers, etc.

Films made of polyimide-based materials such as PAI, which have excellent heat resistance, mechanical properties, and dimensional stability, are widely used as intermediate transfer belts and fixing belts for copiers and printers that require high speed.

These belts can be obtained, for example, by applying a solution containing PAI to a mold and drying it, and are usually used as a seamless belt made of a PAI film with a thickness of 30 μm to 150 μm.

As a PAI film used for these belts, a film made of PAI using trimellitic acid (TMA) as the acid component and o-tolidine diisocyanate (TODI) as the isocyanate component is known. Patent Documents 1 to 5 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 (particularly rigidity).

Japanese Patent Publication No. 2003-147199 Japanese Patent Publication No. 2004-155947 Japanese Patent Publication No. 2003-261768 Japanese Patent Publication No. 2007-16097 Japanese Patent Publication No. 2011-79965

However, the belt made of PAI using TMA as the acid component and TODI as the isocyanate component described in the above patent document does not have sufficient strength as a belt, that is, elongation when used as a film, and the belt is attached to a copier for a long time. When used, rupture or cracking may occur. In this regard, PAI used as a belt for copiers is required to have a high elastic modulus (rigidity) when turned into a film, as well as a high elongation. In other words, a PAI that can achieve both high elastic modulus and high elongation, which is a trade-off relationship, was required.

Therefore, the present invention solves the above problems and aims to provide PAI that can produce a PAI film that has both a high elastic modulus and high elongation when molded into a film.

As a result of intensive research to solve the above problems, it was discovered that the above problems could be solved by using a novel PAI with a specific chemical structure and a specific monomer composition, and the present invention was completed.

The present invention uses TMA and dimer acid (DA) as the acid components and TODI as the isocyanate component, DA is less than 30 mol% relative to the total number of moles of TMA and DA, and 10 to 50 mol% of TODI. The intent is “PAI substituted with methylene diphenyl diisocyanate (MDI) and/or toluene diisocyanate (TDI).”

By molding the PAI of the present invention into a film form, a PAI film having both a high elastic modulus and high elongation can be obtained. Therefore, the PAI belt made of this PAI film can be suitably used as an intermediate transfer belt and fixing belt for copiers and printers.

Hereinafter, the present invention will be described in detail.

PAI of the present invention can be obtained as a solution, for example, by the following method.

That is, it can be obtained by subjecting approximately equimolar amounts of TMA and DA (acid components) and an isocyanate component containing TODI to a polymerization reaction in a solvent.

The molar ratio between the acid component and the isocyanate component is preferably 1/1.00 to 1.05.

Here, since the polymer consisting only of TMA, DA, and TODI tends to be difficult to dissolve in the reaction solvent, 10 to 50 mol% of TODI is added to methylene diphenyl diisocyanate (MDI) and/or toluene diisocyanate. It is necessary to replace it with anate (TDI). (Hereinafter, the ratio in which TODI is replaced by the total amount of MDI and/or TDI is simply referred to as the “substitution ratio”.) If the substitution ratio is too low, gelation occurs during the synthesis reaction of PAI, making it impossible to prepare a solution. If the substitution ratio is too high, the elastic modulus decreases and the buckling characteristics decrease. The substitution ratio is preferably 15 to 45 mol% from the viewpoint of further improvement in elongation and elastic modulus.

In addition, as the acid component, from the viewpoint of achieving both high elongation and high elastic modulus, it is necessary to use TMA and DA, and to set DA to less than 30 mol% relative to the total number of moles of TMA and DA. If the amount of DA used is too large, the elastic modulus decreases and the buckling characteristics decrease. Here, the amount of DA used is preferably 20 mol% or less, relative to the total number of moles of TMA and DA, since high elongation can be achieved while maintaining high elastic modulus, and 0.5 mol% or more and 20 mol% or less. It is more desirable to do so.

By keeping the amount of DA used within this range, it is possible to achieve both dynamic characteristic values in the trade-off relationship of high elongation and high elastic modulus.

Here, DA (dimeric acid) is a fatty acid whose main component is a dibasic acid of C36 dicarboxylic acid produced by dimerization of C18 unsaturated fatty acid made from vegetable oils and fats, and is commercially available from Croda Japan, Tsuno Food Industry, etc. It can be obtained as.

On the other hand, part of TMA may be substituted with another acid component. Specifically, if it is 10 mol% or less of TMA, it is pyromellitic anhydride, 3,3',4,4'-benzophenonetetracarboxylic anhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride, etc. It may be substituted. If this substitution ratio exceeds 10 mol%, it may become difficult to achieve both mechanical characteristic values.

The PAI of the present invention may be obtained by mixing two or more types of PAI with different polymer compositions.

In the polymerization reaction, a basic compound such as 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) or triethylenediamine (DABCO) is added as a catalyst in an amount of 0.01 to 1 mol% relative to TMA. desirable.

By using such a basic catalyst, PAI with a higher degree of polymerization can be obtained.

Although these basic catalysts are known as polymerization catalysts for PAI polymerization, they are specifically effective in the polymerization reaction of PAI consisting of an isocyanate component including TMA, DA, and TODI.

There are no restrictions on the solvent used in the polymerization reaction, but it is preferable to use an amide-based solvent. Specific examples of amide-based solvents include N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMAc). These solvents can be used individually or as a mixture. Among these, NMP, DMAc, and mixtures thereof are preferred. These polymerization solvents are preferably dehydrated to a moisture content of 100 ppm or less.

The reaction temperature when performing the polymerization reaction is preferably 100 to 200°C, and more preferably 120 to 180°C. In this reaction, the order of addition of monomers and solvents is not particularly limited and may be any order.

The range of solution viscosity of the solution containing PAI of the present invention obtained as described above is not particularly limited, but from the viewpoint of formability into belts, etc., it is preferably 10 Pa·s or more and 200 Pa·s or less, and 80 Pa·s. It is more preferable to set it to 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 Tokimex Corporation.

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 15% by mass or more and 22% by mass or less.

The solution containing the PAI of the present invention may be obtained by mixing two or more types of PAI solutions for the purpose of adjusting the polymer composition, solvent, viscosity, concentration, etc.

When a solution containing the PAI of the present invention is used as a solution for forming a belt, a conductive filler such as carbon black or graphite particles can be added to adjust the charging characteristics of the belt.

The solution containing the PAI of the present invention obtained as described above can be applied onto a substrate and dried to form a film made of the PAI of the present invention.

There are no restrictions on the substrate used, but metal foils such as copper foil, and organic polymer films such as polyester films and polyimide films can be preferably used.

Additionally, a seamless belt made of a PAI film can be made by applying a solution containing the PAI of the present invention to a cylindrical mold, drying it, and then demolding it.

On the other hand, as drying conditions for obtaining a film from a PAI solution, it is preferable to pre-dry at a temperature of 50 to 180°C and then set to 200 to 300°C.

Additionally, there is no limitation on the thickness of the molded PAI film, but it is usually about 1 to 200 μm.

The PAI of the present invention preferably has a tensile elongation of 60% or more, a tensile modulus of elasticity of 3.5 GPa or more, and more preferably a tensile elongation of 70% or more when formed into a film. The upper limits of tensile elongation and tensile elastic modulus that can be realized when the PAI of the present invention is used as a film are approximately 200% and approximately 20 GPa, respectively.

Here, the tensile elastic modulus and tensile elongation of the PAI film can be confirmed by measuring based on JIS K7127:1999.

The PAI of the present invention has improved tear resistance (MIT count) as a copier belt by increasing the tensile elongation when used as a film to 60% or more, making it a belt when mounted on a copier and used for a long time. It can prevent breakage or cracking.

Here, the tear resistance characteristics (MIT number) of the belt can be confirmed by measuring a film cut from the belt under a load of 9.8N in accordance with JIS-P8115 (2001), and the MIT number is 2000 or more. desirable.

In addition, the PAI of the present invention has a tensile modulus of elasticity of 3.5 GPa or more when made into a film, thereby improving the buckling characteristics as a copier belt, preventing deformation of the belt when mounted on a copier and used for a long time. there is.

Here, the buckling characteristics of the belt can be confirmed by installing the belt between two parallel metal plates and measuring the load when the belt is compressed and buckled at a speed of 1 mm/sec, and this load is 2.0 kg or more. It is desirable.

In addition to belts, the PAI of the present invention can be molded into any shape, such as a film, fiber, non-woven fabric, or filler, using any molding method, similar to conventional PAI resins.

In addition, the solution containing the PAI of the present invention can be used as a varnish for various applications such as electric wire coating, printing ink, optical fiber film, IC coating material, and heat-resistant paint.

Additionally, it is possible to manufacture a flexible printed circuit board by coating varnish on metal foil and heat treating it.

Example

Hereinafter, the present invention will be described in detail based on examples, but is not limited to these examples.

<Example 1>

In a glass reaction vessel, under a nitrogen atmosphere, TMA: 0.985 mol, DA: 0.015 mol ("PRIPOL1009", manufactured by Croda Japan), TODI: 0.82 mol, MDI: 0.20 mol, and DABCO: 0.0005 mol were added at a solid concentration of 20% by mass. was added together with dehydrated NMP (moisture content: 80 ppm), raised to 150°C with stirring, and reacted for 5 hours to obtain PAI with a solution viscosity of 135 Pa·s at 30°C and a PAI solid concentration of 18% by mass. A solution (PAI-1) was obtained.

Next, this PAI solution (PAI-1) was applied onto the polyester film, and after drying at 80°C for 10 minutes and 130°C for 10 minutes, the coating film was peeled from the polyester film. Thereafter, this coating film was placed on a metal frame and dried at 290°C for 60 minutes in a nitrogen gas atmosphere to obtain a PAI film with a thickness of 40 μm.

Table 1 shows the results of measuring the tensile elastic modulus and tensile elongation of the PAI film by the method based on the JIS described above.

<Example 2>

Except that the acid components were changed to "TMA: 0.97 mol, DA: 0.03 mol," a PAI solution (PAI-2) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 3>

Except that the acid components were changed to "TMA: 0.94 mol, DA: 0.06 mol," a PAI solution (PAI-3) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 4>

Except that "MDI: 0.20 mole" of the isocyanate component was changed to "TDI: 0.20 mole", a PAI solution (PAI-4) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 5>

Same as Example 1, except that “TODI: 0.82 mole” of the isocyanate component was changed to “TODI: 0.8 mole” and “MDI: 0.20 mole” was changed to “MDI: 0.11 mole and TDI: 0.11 mole”. A PAI solution (PAI-5) was prepared, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 6>

Except that the isocyanate components were changed to "TODI: 0.61 mol, MDI: 0.40 mol", a PAI solution (PAI-6) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 7>

Except that the isocyanate components were changed to "TODI: 0.61 mol, TDI: 0.40 mol", a PAI solution (PAI-7) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 8>

Except that the acid components were changed to "TMA: 0.90 mol, DA: 0.10 mol," a PAI solution (PAI-8) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 9>

Except that the acid components were changed to "TMA: 0.85 mol, DA: 0.15 mol," a PAI solution (PAI-9) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 10>

Except that the acid components were changed to "TMA: 0.8 mol, DA: 0.2 mol," a PAI solution (PAI-10) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 11>

Except that the isocyanate components were changed to "TODI: 0.51 mol, MDI: 0.5 mol", a PAI solution (PAI-11) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 12>

Except that the isocyanate components were changed to "TODI: 0.9 mol, MDI: 0.12 mol", a PAI solution (PAI-12) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Example 13>

A PAI solution (PAI- 13) was prepared, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Comparative Example 1>

Except that the acid component was changed to "TMA: 1.00 mole", a PAI solution (PAI-14) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Comparative Example 2>

Except that the acid components were changed to "TMA: 0.70 mol, DA: 0.30 mol," a PAI solution (PAI-15) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Comparative Example 3>

Except that the isocyanate components were changed to "TODI: 0.4 mol, MDI: 0.62 mol", a PAI solution (PAI-16) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

<Comparative Example 4>

Except that the acid component was set to “TMA: 1 mole” and the isocyanate component was set to “MDI: 1.02 mole,” a PAI solution (PAI-17) was prepared in the same manner as in Example 1, and a PAI film was made using this. got it The results of measuring the film properties are shown in Table 1.

<Comparative Example 5>

A PAI solution (PAI-18) was prepared in the same manner as in Example 1, except that the acid component was "TMA: 0.95 mol, DA: 0.05 mol" and the isocyanate component was "MDI: 1.02 mol". A PAI film was obtained using this method. The results of measuring the film properties are shown in Table 1.

<Comparative Example 6>

A PAI solution (PAI-19) was prepared in the same manner as in Example 1, except that the acid component was "TMA: 0.9 mol, DA: 0.1 mol" and the isocyanate component was "MDI: 1.02 mol". A PAI film was obtained using this method. The results of measuring the film properties are shown in Table 1.

<Comparative Example 7>

Except that the isocyanate component was changed to "TODI: 1.02 mol", a PAI solution (PAI-20) was prepared in the same manner as in Example 1, and a PAI film was obtained using this. The results of measuring the film properties are shown in Table 1.

The PAI solutions (PAI-1 to PAI-20) obtained in Examples 1 to 13 and Comparative Examples 1 to 7 were applied with a dispenser to the outer surface of a cylindrical mold with an outer diameter of 200 mm and a circumference length of 330 mm, and then rotated to create a uniformly coated surface. got it After blowing hot air at 80°C for 30 minutes from the outside of the mold, it was dried at 130°C for 60 minutes and then at 260°C for 90 minutes in a nitrogen gas atmosphere. Afterwards, it was returned to room temperature (25°C) and peeled from the mold to obtain a PAI belt with a thickness of 70 μm.

Table 1 shows the results of evaluating the folding resistance and buckling characteristics of this PAI belt using the above-mentioned method based on the following criteria.

<Evaluation criteria>

Resistance characteristics: The number of MITs between 2000 and 3000 times was designated as “○”, and the number of MITs less than 2000 times was designated as “×”. The number of MITs over 3000 was set to “◎”.

Buckling characteristics: The load at the time of buckling was set to “○” for 2.0 kg or more, and “×” for less than 2.0 kg.

In addition, Table 1 shows the results of evaluating the tensile elongation and tensile modulus of the PAI belt based on the following standards.

<Evaluation criteria>

Tensile elongation: Tensile elongation of 60% or more and less than 70% was designated as “○”, and less than 60% was designated as “×”. Tensile elongation of 70% or more was set to “◎”.

Tensile elastic modulus: Tensile elastic modulus of 3.5 GPa or more and less than 4.5 GPa was designated as “○”, and less than 3.5 GPa was designated as “×”.

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

In addition, it can be seen that the belt made of PAI of the present invention has good tear resistance and buckling characteristics.

The film made of PAI of the present invention is a seamless PAI belt and can be suitably used as an intermediate transfer belt and fixing belt for copiers and printers.

Claims (6)

Trimellitic anhydride (TMA) and dimer acid (DA) were used as the acid components, and o-tolidine diisocyanate (TODI) was used as the isocyanate component, and DA was 30 relative to the total number of moles of TMA and DA. Polyamideimide (PAI) in which 10 to 50 mol% of TODI is substituted with methylene diphenyl diisocyanate (MDI) and/or toluene diisocyanate (TDI). According to claim 1,
A PAI characterized by a tensile elongation of 60% or more and a tensile modulus of elasticity of 3.5 GPa or more when made into a film. According to claim 1,
PAI where the amount of DA used is 0.5 mol% or more and 20 mol% or less relative to the total number of moles of TMA and DA. A copier belt using the PAI according to any one of claims 1 to 3. A PAI solution comprising the PAI according to any one of claims 1 to 3 and an organic solvent. According to claim 5,
A PAI solution in which the organic solvent is an amide-based solvent.