JP2002069181A - Aromatic polyimide copolymer and aromatic polyimide composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aromatic polyimide material having mechanical strengths and molding processability which are comparable with or higher than those of conventional materials, and having improved thermal characteristics. SOLUTION: The aromatic polyimide copolymer comprises, as the principal structural units, a structural unit expressed by general formula (I): where Ar is represented by formula (III) or (IV), and a structural unit expressed by general formula (II): where Ar is represented by formula (III) or (IV) and X denotes -O-, -CH2-, -SO-, -SO2- or -CO-.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aromatic polyimide copolymer and an aromatic polyimide composition. The aromatic polyimide copolymer and aromatic polyimide composition of the present invention are excellent in mechanical properties, dimensional stability, heat resistance and the like, and are used, for example, as a film or a seamless tubular body.

[0002]

2. Description of the Related Art Conventionally, aromatic polyimides have heat resistance,
Because of its excellent mechanical and electrical properties, it is widely used in various fields such as materials for space and aircraft, electrical and electronic materials, and heat-resistant fiber materials. For example, an aromatic polyimide produced from pyromellitic dianhydride and 4,4'-diaminodiphenyl ether, or an aromatic polyimide produced from 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine Aromatic polyimide has excellent heat resistance,
It is used as a film having mechanical properties. By combining an acid component (or an amine component) exhibiting rigidity and an amine component (or an acid component) exhibiting flexibility, these aromatic polyimides have a moldability of a thin film and a high elastic modulus. The mechanical strength of this is developed.

However, the aromatic polyimide is
The material properties required for the above applications are not sufficiently satisfied. For this reason, aromatic polyimides are required to be more diverse and sophisticated. For example, an image recording material is one example of a field in which aromatic polyimides are used.In the case of an image recording material, the required characteristics have been diversified and advanced with an increase in processing speed and image quality. Improvement of thermal properties is also one of the required characteristics.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polyimide material having the same or higher mechanical strength and moldability as before, and having improved thermal properties. . Still another object of the present invention is to provide a film and a seamless tubular body using an aromatic polyimide material.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the object can be achieved by the following aromatic polyimide copolymer and aromatic polyimide composition. And completed the present invention.

That is, the present invention provides a compound represented by the general formula (I):

Embedded image And a structural unit represented by general formula (II):

Embedded image And an aromatic polyimide copolymer having a structural unit represented by the following as a main structural unit.

Further, the present invention provides a compound represented by the following general formula (I):

Embedded image An aromatic polyimide (I) having a structural unit represented by the following as a main structural unit, and a general formula (II):

Embedded image The present invention relates to an aromatic polyimide composition containing a blend of an aromatic polyimide (II) having a structural unit represented by the following as a main structural unit.

The aromatic polyimide copolymer or the aromatic polyimide composition of the present invention has the general formula (I)
, Thereby realizing mechanical strength and thermal characteristics (high heat resistance, low coefficient of thermal expansion). Further, the aromatic polyimide copolymer or the aromatic polyimide composition has a structural unit represented by the general formula (II), thereby imparting flexibility and realizing moldability. I have.

From this viewpoint, the aromatic polyimide copolymer has a structural unit represented by the general formula (I) of 10 to 9
5% by weight, and 90 units of the structural unit represented by the general formula (II)
It is preferable that the composition be in a ratio of about 5% by weight. The structural ratio is such that the structural unit represented by the general formula (I) is 15
It is more preferable that the composition unit represented by the formula (II) is contained in a proportion of 85 to 90% by weight, more preferably 20 to 85% by weight, and 85 to 10% by weight, more preferably 80 to 15% by weight. .

[0010] From the above viewpoint, the aromatic polyimide composition comprises 10 to 95% by weight of the aromatic polyimide (I) and 90 to 5% by weight of the aromatic polyimide (II). Is preferred. The composition ratio is
15 to 90% by weight of aromatic polyimide (I), further 20 to 85% by weight, and 85% of aromatic polyimide (II)
More preferably, it is constituted in a ratio of 10 to 10% by weight, more preferably 80 to 15% by weight.

As the physical properties of the aromatic polyimide copolymer or the aromatic polyimide composition, it is preferable that the tensile elastic modulus is 4.0 GPa or more and the thermal expansion coefficient is 30 ppm or less. The tensile modulus is more preferably 4.5 GPa or more, and the thermal expansion coefficient is more preferably 20 ppm or less. Those having such physical properties have excellent mechanical strength and thermal properties. Tensile modulus is JIS K
7127 (1999), the coefficient of thermal expansion is JIS K71
97 (1999).

Further, the present invention relates to a film formed using the aromatic polyimide copolymer or the aromatic polyimide composition. The present invention also relates to a seamless tubular body formed using the aromatic polyimide copolymer or the aromatic polyimide composition. The aromatic polyimide copolymer or aromatic polyimide composition of the present invention is useful, for example, as a film or a seamless tubular body.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic polyimide copolymer, aromatic polyimide (I) and aromatic polyimide (II) of the present invention are obtained by reacting an acid dianhydride component with a diamine component to obtain a polyamic acid, It is produced by dehydration ring closure and imide conversion.

As the acid anhydride component, biphenyltetracarboxylic dianhydride and / or pyromellitic dianhydride are used. As biphenyltetracarboxylic acid,
3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride are exemplified.

On the other hand, as the diamine component, those which form the structural units represented by the general formulas (I) and (II) are used. As the diamine component forming the structural unit represented by the general formula (I), 2,2′-dimethylbenzidine is used. Examples of the diamine component forming the structural unit represented by the general formula (II) include 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane,
Flexible diamines such as 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminobenzophenone are exemplified.

In order to obtain an aromatic polyimide copolymer, these diamine components have the general formula (I) and the general formula (I)
2,2′-dimethylbenzidine and a flexible diamine are used so that the structural unit represented by I) has the above structural ratio. When aromatic polyimide (I) is obtained, an acid dianhydride component is reacted with 2,2′-dimethylbenzidine, and when aromatic polyimide (II) is obtained, an acid dianhydride component and The flexible diamine is reacted. Then, an aromatic polyimide composition is prepared by blending the aromatic polyimide (I) and the aromatic polyimide (II) so as to have the above composition ratio.

The polymerization or copolymerization reaction between the acid dianhydride component and the diamine component is carried out in a solvent. As the solvent, a polar solvent is preferably used from the viewpoint of solubility. Specifically, organic polar solvents such as N, N-dialkylamides are useful. As the organic polar solvent, for example, N,
N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone , Pyridine, dimethyl sulfoxide, tetramethylene sulfone, dimethyltetramethylene sulfone and the like. These organic polar solvents may be used alone or in combination. further,
Phenols such as cresol, phenol and xylenol, benzonitrile, dioxane, butyrolactone, xylene, cyclohexane, hexane, benzene and toluene can be used alone or in combination in the organic polar solvent.

[0018] Polyamic acid is produced by such a reaction. Since polyamic acid is hydrolyzed to lower molecular weight by the presence of water, the synthesis of polyamic acid is preferably performed under substantially anhydrous conditions.

The monomer concentration (the concentration of the acid dianhydride component and the diamine component in the solvent) when the polyamic acid is produced is set according to various conditions. Further, the reaction temperature is preferably set to 80 ° C or lower, particularly preferably 5 to 50 ° C. By setting the reaction temperature within the above range, the rise in solution viscosity can be adjusted as the reaction proceeds.
Solution viscosity is 25 ° C in B-type viscometer from the viewpoint of processability and the like.
Is preferably adjusted to 0.1 to 10,000 poise. Further, the solution viscosity can be adjusted by the monomer concentration.

After the polyamic acid thus produced is formed into a desired form, it is converted into an aromatic polyimide by removing the solvent, removing the dehydrated ring-closing water, and completing the imide conversion reaction. The blend of the aromatic polyimide (I) and the aromatic polyimide (II) is performed in the state of polyamic acid.

The aromatic polyimide copolymer or aromatic polyimide composition thus obtained can be used for various purposes, but is particularly used as a material for thin-walled sheet-like molded articles such as films and seamless tubular bodies. Useful to use.

A known method can be used for forming the film or the seamless tubular body. Specifically, when forming a film, after casting a polyamic acid on a glass plate, a stainless steel substrate, a substrate such as a stainless steel belt,
A method of heating and drying is generally used.

In the case of molding into a seamless tubular body, a polyamic acid is applied to the inner surface or the outer surface of the cylindrical mold by dip coating, spray coating, dispersion coating, or the like, and then the tube is formed in order to increase the film thickness accuracy. An unnecessary polyamic acid is removed by an outer mold, a bullet-shaped traveling body, a scraper, or the like, or formed by a centrifugal molding method or the like. At this time, the film thickness accuracy is determined by the monomer concentration and the solution viscosity, and the surface roughness of the inner surface of the mold determines the surface accuracy of the tubular body. Therefore, these can be determined according to the design of the tubular body. Has a monomer concentration of 3 to 50% by weight, preferably 5 to 40% by weight. The solution viscosity is 0.1 to 10,000 poise, preferably 0.5 to 7000 poise, more preferably 1 to 10,000 poise.
5000 poise. Solution viscosity is a major factor that affects dimensional accuracy such as film thickness accuracy of the tubular body, and it is not preferable because if the viscosity is less than the above, uneven thickness is likely to occur,
If the viscosity exceeds the above range, the moldability during production becomes poor, which is not preferable. Next, a seamless tubular body can be obtained by removing the solvent, removing the dehydrated ring-closing water and completing the imide conversion reaction in the same manner as in the case of the film.

The aromatic polyimide copolymer or the aromatic polyimide composition may have desired organic powder, inorganic powder, or inorganic powder depending on required characteristics such as conductivity, semi-conductivity, high thermal conductivity, and high strength. Fillers such as inorganic oxides, metals, metal oxides, surfactants and fibers can be included. Fillers are added to the polyamic acid. The content of the filler is not particularly limited and can be appropriately determined depending on the type thereof, but the content is 1 to 60 per 100 parts by weight of the polyimide resin (solid content).
It is preferable that the amount be 3 parts by weight, especially 3 to 50 parts by weight, since desired functions can be exhibited without deteriorating various properties of the novel aromatic polyimide resin. Also, if desired, on the outer surface of the tubular body,
A metal layer, a release layer of silicone rubber, fluorine rubber, fluorine resin, or the like may be provided.

Although the specific application of the aromatic polyimide resin film of the present invention is not particularly limited, it is suitably used for a circuit board of an FPC, a base of a heat-resistant tape, and the like. Further, the specific use of the aromatic polyimide resin seamless tubular body of the present invention is not particularly limited and can be used in a wide range of fields, but is particularly used for an image forming apparatus such as a copying machine and a laser beam printer. It can be suitably used as a functional belt such as a fixing belt, a transfer belt, a transport belt, and a photoreceptor belt, a transport belt for transporting a paper sheet or a card such as an ATM or a public telephone, or a base material thereof.

[0026]

EXAMPLES Hereinafter, the aromatic polyimide copolymer and the aromatic polyimide composition of the present invention, and the film and the seamless tubular body of the present invention will be described in detail with reference to examples.

Example 1 (Preparation of Aromatic Polyamic Acid (Copolymer) Solution) N-methyl-2 was placed in a 500 ml four-necked flask purged with nitrogen.
-Pyrrolidone (312 g), 2,2'-dimethylbenzidine (25.5 g, 61.4% by weight in the diamine component) and 4,4'-diaminodiphenyl ether (16.0 g, diamine) as diamine components. (38.6% by weight in the mixture) and dissolved with stirring at room temperature. Next, pyromellitic dianhydride (43.6 g) was added as an acid dianhydride, and the polymerization reaction was performed with stirring for a certain period of time. As a result, the viscosity gradually increased. This aromatic polyamic acid solution was stirred while being heated at 75 ° C. for 24 hours to obtain an aromatic polyamic acid solution (solid content concentration: 20% by weight) having a solution viscosity of 2500 poise by a B-type viscometer (25 ° C.). Was.

(Production of Aromatic Polyimide Film) The aromatic polyamic acid solution obtained above was cast on a stainless steel substrate to a thickness of about 400 μm and dried at 130 ° C. for 20 minutes. To obtain a self-supporting film. Add 350 more of this film
The solution was heated stepwise to ℃ to remove the solvent, remove the dehydrated ring-closing water and complete the reaction of imide conversion to obtain an aromatic polyimide film having a thickness of 80 μm. This film has good surface accuracy and is JIS K 7127 (1999)
The tensile modulus was measured to be 5.8 GPa according to JIS K 7197 (1999), and the thermal expansion coefficient was measured to be 12.6 ppm according to JIS K 7197 (1999).

(Production of a Seamless Tubular Body Made of Aromatic Polyimide) The aromatic polyamic acid solution obtained above was applied to the inner surface of a cylindrical mold having an inner diameter of about 40 mm and a length of 500 mm with a dispenser by about 150 mm from above. Next, the bullet-shaped traveling body is dropped from inside into the mold by its own weight,
The thickness was uniform (400 μm). The mold was heated and cured stepwise from room temperature to 350 ° C. to remove the solvent, remove the dehydration ring-closing water and complete the imide conversion reaction, and then cooled to room temperature to cure the mold from the cylindrical mold. A tubular body (film thickness 74 μm) was obtained. This tubular body has good surface accuracy on both the inner surface and the outer surface. When this is cut out and measured for the tensile modulus in accordance with JIS K7127 (1999), it is 5.3 GPa and JIS K719.
7 (1999).
It was 1.8 ppm.

Example 2 (Preparation of Aromatic Polyamic Acid (Blend) Solution) In a 500 ml four-necked flask purged with nitrogen, N-methyl-
2-Pyrrolidone (312 g) was added, and 2,2′-dimethylbenzidine (25.5 g) was added as a diamine component, and the mixture was dissolved with stirring at room temperature. Then, pyromellitic dianhydride was used as an acid dianhydride. (43.6 g) and the polymerization reaction was carried out with stirring for a certain period of time.
The viscosity gradually increased. By stirring this aromatic polyamic acid solution while heating at 75 ° C. for 24 hours, B
An aromatic polyamic acid solution (solid content concentration: 20% by weight) having a solution viscosity of 2000 poise by a mold viscometer (25 ° C) was obtained. Separately, 2,2′-dimethylbenzidine (25.5)
g) instead of 4,4'-diaminodiphenyl ether (16.0 g), and an aromatic polyamic acid solution (solid content: 2000 poise) having a solution viscosity of 2000 poise by a B-type viscometer (25 ° C.) Concentration of 20% by weight). The obtained aromatic polyamic acid solution was mixed to obtain an aromatic polyamic acid solution (solid content concentration: 20% by weight). Thereafter, in the same manner as in Example 1, an aromatic polyimide film,
An aromatic polyimide seamless tubular body was produced.

The obtained film had good surface accuracy, and its tensile modulus was measured according to JIS K 7127 (1999) to be 5.4 GPa.
The coefficient of thermal expansion was measured according to 7197 (1999) and found to be 12.3 ppm. This tubular body has good surface accuracy on both the inner surface and outer surface.
The tensile modulus was measured in accordance with K 7127 (1999) and found to be 5.1 GPa.
11. The coefficient of thermal expansion was measured according to (1999).
It was 1 ppm.

[0032]

According to the present invention, there is provided a novel aromatic polyimide having mechanical strength equal to or higher than that of a conventional aromatic polyimide, and having excellent thermal properties such as high heat resistance and a low coefficient of thermal expansion. It is possible to provide a resin and a film and a seamless tubular body having the above excellent properties.

Continued on the front page (72) Inventor Shu Mochizuki 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Yoshiki Ikeyama 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko stock In-company F-term (reference) 4F071 AA60 AA83 AF15 AF20 AF62 AH12 AH13 AH17 BA02 BB02 BC01 BC05 BC17 4J002 CM04W CM04X GM00 GM01 GQ01 4J043 PA01 PA05 PA08 PC016 QB31 RA23 RA34 SA06 SB03 TA22 TB01 UA122 UA131 UA131 UA131 UA131 UA131 ZA32 ZA35 ZB04 ZB11 ZB50

Claims (7)

[Claims] 1. A compound of the general formula (I): And a structural unit represented by the general formula (II): An aromatic polyimide copolymer having a structural unit represented by the following as a main structural unit. 2. The structural unit represented by the general formula (I) is 10
The aromatic polyimide copolymer according to claim 1, wherein the proportion of the structural unit represented by the general formula (II) is from 90 to 5% by weight. 3. A compound of the general formula (I): An aromatic polyimide (I) having a structural unit represented by the following as a main structural unit, and a general formula (II): An aromatic polyimide composition containing a blend of an aromatic polyimide (II) having a structural unit represented by the following as a main structural unit. 4. The aromatic polyimide composition according to claim 3, wherein the content of the aromatic polyimide (I) is 10 to 95% by weight and the content of the aromatic polyimide (II) is 90 to 5% by weight. 5. The aromatic polyimide copolymer according to claim 1 or 2, wherein the tensile modulus is 4.0 GPa or more and the thermal expansion coefficient is 30 ppm or less.
The aromatic polyimide composition according to the above. 6. A film formed using the aromatic polyimide copolymer or the aromatic polyimide composition according to claim 1. 7. A seamless tubular body formed by using the aromatic polyimide copolymer or the aromatic polyimide composition according to claim 1.