JP4008978B2 - Resin composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin composition. More specifically, the present invention relates to a resin composition characterized by adding a conductive filler and a non-conductive inorganic filler and having a volume resistivity of 10 ⁸ to 10 ¹⁵ Ω · cm.
[0002]
[Prior art]
Polyimide film has excellent heat resistance, low temperature properties, chemical resistance, mechanical properties, electrical properties, etc., so it is widely used especially as a material for electrical and electronic equipment applications. Utilizing these characteristics, they are being applied to various purposes. In contrast, fluororesins are widely used in lubricants and containers because of their excellent heat resistance, chemical resistance, and low friction coefficient.
[0003]
[Problems to be solved by the invention]
These resins are completely non-conductive, and when used for applications that require electrical conductivity, add conductive fillers to these resins or apply antistatic agents to the surface. Therefore, conductivity was obtained. However, as a characteristic of this conductive filler, there is a tendency that when a small amount is added, the conductivity is not exhibited, and when an amount exceeding a certain threshold is added, the resistance rapidly decreases. For example, when carbon black is used as a conductive filler, a volume resistivity of about 10 ¹⁵ to 10 ¹⁶ Ω · cm is shown when added to the resin at a few percent in terms of weight, but more than that is added. As the amount increases by 1% in a certain threshold region, the resistance value changes by 2 to 4 digits. Above a certain amount, the volume resistivity becomes 10 ⁶ to 10 ⁸ Ω · cm, and there is a tendency for almost no change. Indicates. Therefore, the area of 10 ⁸ to 10 ¹⁴ Ω · cm, which is required for use in laser printer transfer bodies and fixing rollers, cannot be stably achieved by simply adding carbon black, and the resin surface Alternatively, a method in which a conductive layer is formed inside and the volume resistivity in this region as a whole film is realized is the mainstream.
[0004]
However, since this method requires a plurality of layers of resin, the cost is high, and it is difficult to control a delicate resistance value.
Therefore, in view of the above situation, the present inventors have found that the above-mentioned problems can be solved by adding conductive carbon and non-conductive inorganic filler to the resin as a result of intensive studies and completed the present invention. Is.
[0005]
[Means for Solving the Problems]
The gist of the resin composition according to the present invention is that a conductive filler and at least one non-conductive inorganic filler are added to the resin, and the volume resistivity is 10 ⁸ to 10 ¹⁵ Ω · cm. The resin composition is characterized in that (Claim 1).
The resin composition according to claim 1, wherein the resin is composed of polyimide alone or polyimide and fluororesin (claim 2),
Furthermore, the structure of the polyimide has the general formula (1)
[0006]
[Chemical 6]
[0007]
3. The resin according to claim 1, wherein Ar ₁ is a tetravalent organic group, Ar ₂ is a divalent organic group, and n is an integer of 1 or more. A composition (claim 3);
Ar ₁ in the general formula (1) is
[Chemical 7]
[0009]
[Chemical 8]
[0010]
It consists of at least 1 type represented by these, It is a resin composition in any one of Claims 1-3 (Claim 4),
Ar ₂ in the general formula (1) is
[Chemical 9]
[0012]
Embedded image
[0013]
The resin composition according to any one of claims 1 to 4, wherein the resin composition is at least one type represented by the formula (Claim 5).
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The resin composition according to the present invention is mainly composed of a polyimide alone or a polyimide and a fluororesin as a main component, and particularly a resin mainly composed of a polyimide represented by the general formula (1) and a fluororesin. The polyimide that is the main component of the resin according to the present invention has excellent heat resistance, chemical resistance, and wear resistance. Of these, polyimide having an ester group exhibits thermoplasticity, has very good processability and has a characteristic of low water absorption. This polyimide can be polymerized from the monomer by a conventionally used method. Moreover, the fluororesin which is a component of this resin composition has non-adhesiveness and hydrophobicity due to its structure having a fluorine atom. In addition, it has a low coefficient of friction, chemical resistance, and heat resistance. Resins prepared using these two kinds of excellent resins as the main components exhibit excellent characteristics without impairing the excellent characteristics of both.
[0015]
Any form of conductive filler may be used. For example, carbon black, metal, metal oxide, and metal nitride. The addition amount may be such a small addition amount that the volume resistivity of the resin exhibits 10 ¹² to 10 ¹⁶ Ω · cm when the non-conductive inorganic filler is not added and it is added alone. For example, in the case of carbon black, it is preferably 0.5 to 5%, more preferably 2 to 5%. Any non-conductive inorganic filler can be considered, but when added alone to the resin, when the amount of non-conductive inorganic filler contained in the resin is 20 wt%, the volume resistivity of the resin is low. It should be 10 ¹⁴ Ω · cm or higher. Preferably, mica, glass beads, smectite, boron nitride, titanate whiskers and the like are preferable. The addition amount is preferably 10 to 40%, more preferably 15 to 35%. However, the amount of conductive filler and non-conductive filler has an optimum region depending on the combination of each type. For example, in the case of a combination of carbon black and swellable mica, 3 to 5% of carbon black, swellable mica 15 ~ 25%. The fluororesin is not particularly limited. In the case of polytetrafluoroethylene, any melting point may be used, but the melting point is preferably 325 ° C. or higher. Polytetrafluoroethylene has a melting point determined by its molecular weight, but when the melting point is 325 ° C. or lower, the thermal decomposition temperature is low and the heat resistance is poor.
[0016]
Any method may be used to obtain a uniform resin by mixing these resins and fillers, but there is a difference in uniformity depending on the method, and thus there is a difference in the volume resistivity of the obtained resin. is there. For example, when polyimide is polymerized as in the conventional method to obtain a polyamic acid solution that is a precursor of the polyimide, filler is mixed with it, and then kneading is repeated with three rolls, the dispersibility of the filler is very high. The volume resistivity can be controlled effectively. Alternatively, a filler may be added in advance to a solvent for polymerizing polyimide, and polymerization may be performed using the solvent to obtain a polyamic acid solution in which the filler is dispersed. This method has an advantage that filler aggregation is less likely to occur. Further, the kneading of the polyamic acid solution with three rolls may be repeated thereafter. The polyamic acid solution obtained by these methods is imidized by a conventionally used method, and can be processed into a film, a tube, or other molded body. Alternatively, a molded body may be obtained by mixing a filler with polyimide by extrusion molding. In this case, a filler may be mixed with the polyimide powder in advance, or may be added at the time of extrusion.
[0017]
The resin composition thus obtained can be controlled to have a volume resistivity of 10 ⁸ to 10 ¹⁵ Ω · cm by changing the amount of the non-conductive inorganic filler.
In addition, if the volume resistivity does not fall outside the scope of the present application without significantly degrading the performance of polyimide and fluororesin, other than stabilizers, lubricants, surfactants, pigments, compatibilizers, polyimide resins and fluororesins These resins may be added, and this is not particularly limited.
Further, the mixing ratio of polyimide and fluororesin is not particularly specified.
[0018]
In the above, application examples have been described in order to clarify the usefulness of the resin composition according to the present invention, but the present invention is not limited thereto, and the present invention is within the scope of the gist of those skilled in the art. Based on the knowledge, the present invention can be implemented in a mode with various improvements, changes, and modifications.
[0019]
【Example】
First, the method for producing polyimide used in the examples of the present invention will be described in detail, but the present invention is not limited to these examples.
Example 1
Into a 50 ml volumetric flask (1), 15.6 g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (hereinafter referred to as BAPP) and 25.4 g of dimethylformamide (hereinafter referred to as DMF) were taken. Was sufficiently dissolved. Further, 1.0 g of BAPP and 10.0 g of DMF were taken into another 50 ml volumetric flask (2) and dissolved sufficiently. On the other hand, 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic acid dianhydride (hereinafter referred to as ESDA) 11 was added to a 500 ml three-necked flask equipped with a stirrer. .9 g, 3,3 ′, 4,4′-benzophenyltetracarboxylic acid dianhydride (hereinafter referred to as BTDA) 6.4 g, and DMF 25.0 g were added, and the atmosphere in the flask was cooled with ice water. Was stirred and dissolved sufficiently with nitrogen. First, the BAPP solution obtained in advance in the 50 ml volumetric flask (1) was gradually put into the 500 ml three-necked flask while stirring. After being left stirring for about 30 minutes, the BAPP solution in the 50 ml volumetric flask (2) was gradually put into the three-necked flask while paying attention to the viscosity of the solution in the three-necked flask. When the viscosity reached 1500 poise, 85.2 g of DMF was further added, and stirring was continued until it became uniform. Further, the BAPP solution in the 50 ml volumetric flask (2) was gradually put into the three-necked flask while paying attention to the viscosity of the solution in the three-necked flask. After reaching the maximum viscosity, the addition of the BAPP solution was terminated and the mixture was allowed to stand with stirring for 1 hour to obtain a polyamic acid polymer solution. Next, 1.40 g of conductive carbon black 3030B manufactured by Mitsubishi Chemical Corporation, 6.98 g of swellable mica Somasif ME-100 manufactured by Corp Chemical Co., and 55.7 g of DMF were taken in a 200 ml beaker and stirred well. And ultrasonic cleaning for 1 hour. Thereafter, this solution was mixed with the above-described polyamic acid polymer solution and stirred well, and then a three-roll roll with a distance between the rolls of 1000 μm was passed five times and kneaded well.
[0020]
The polyamic acid polymer solution thus obtained was applied on a PET film, heated at 80 ° C. for 25 minutes, then peeled off from the PET film and fixed on a metal support, and then 150 ° C., 200 ° C., 250 ° C. Each was heated at 270 ° C. and 300 ° C. for 5 minutes to obtain a thermoplastic polyimide film. The volume resistivity of this film was measured and found to be 3.0 × 10 ¹⁰ Ω · cm.
(Example 2)
In Example 1, the amount of conductive carbon black 3030B was set to 1.05 g, and conductive carbon black and Somasif ME-100 were added in advance to a 500 ml three-necked flask in the same manner as in Example 1. A polyamic acid solution was obtained, a film was further produced, and its volume resistivity was measured and found to be 6.1 × 10 ¹⁴ Ω · cm.
(Comparative Example 1)
The polyamic acid polymer solution before adding the filler prepared in Example 1 was applied onto a PET film, and a thermoplastic polyimide film was obtained in the same manner as in Example 1. The volume resistivity of this film was 10 ¹⁶ Ω · cm or more.
(Comparative Example 2)
A thermoplastic polyimide film was prepared in the same manner as in Example 1 except that Somasif ME-100 manufactured by Co-op Chemical Co., Ltd. was not used, and its volume resistivity was measured to be 10 ¹⁶ Ω · cm or more.
[0021]
【The invention's effect】
As described above, the resin composition according to the present invention can easily control the volume resistivity that has been difficult to control by adding a conductive filler and a non-conductive inorganic filler to the resin. it can. This resin composition can be processed into a film shape, a tube shape, or a molded body by a casting method, extrusion molding, or injection molding, and can be used for various applications.
In addition, the resin composition of the present invention is particularly composed of polyimide and fluorine resin represented by the general formula (1), and thus has excellent characteristics, heat resistance, radiation resistance, mechanical properties, dimensional stability, Excellent film forming accuracy, flame retardancy, abrasion resistance, low coefficient of friction, water repellency, offset property, electrical properties, etc., especially low water absorption, and film formation by melt extrusion method further improves dimensional accuracy and film thickness accuracy Excellent film. For this reason, such resin compositions include, for example, FPC (Flexible Printed Circuit Board), insulation films for electric wires, seat belts, food trays, medical parts such as catheters, optical parts, and precision electric and electronic members using heat resistance. For example, it is suitable for various belts and fixing rollers of copying machines and printers. Further, since the dimensional accuracy is good, it can be used for a driving belt of precision equipment or the like. Furthermore, various uses can be expected in all other fields.

Claims (3)

A resin composition comprising a combination of a conductive filler and at least one non-conductive inorganic filler added to a resin,
The volume resistivity of the resin composition is controlled to 10 ⁸ to 10 ¹⁵ Ω · cm, and
The resin is made of polyimide alone,
The structure of the polyimide is the following general formula (1)
(Ar ₁ represents a tetravalent organic group, Ar ₂ represents a divalent organic group, and n represents an integer of 1 or more.)
The conductive filler is carbon black, the non-conductive inorganic filler is swellable mica,
3. A resin composition comprising 3 to 5% by weight of the carbon black and 15 to 25% by weight of the swellable mica . Ar in the general formula (1) ₁ But
It consists of at least 1 type represented by these. The resin composition of Claim 1 characterized by the above-mentioned. Ar in the general formula (1) ₂ But
It consists of at least 1 type represented by these. The resin composition of Claim 1 or 2 characterized by the above-mentioned.