JPH0249055A - Electrically semiconducting resin composition - Google Patents

Abstract

PURPOSE:To obtain an electrically semiconducting resin composition, containing polypyrrole distributed in a matrix resin having stabilized electrical characteristics by reducing the residual amount of an oxidative polymerization catalyst for pyrrole to a specific value or below by removing the catalyst. CONSTITUTION:An electrically semiconducting resin composition obtained by dissolving (A) a matrix resin (e.g., nylon 6/nylon 66/nylon 610 terpolymer nylon) in an organic solvent (e.g., methanol), then adding (B) a pyrrole monomer (e.g., N-alkylpyrrole), stirring the resultant solution at -40 to 0 deg.C temperature, subsequently adding (C) an oxidative polymerization catalyst for polymerizing the pyrrole in an amount of 0.5-4mol based on 1mol component (B), polymerizing the monomer and dipping the obtained polymer in clean water for 1 to 2 days and nights to remove the catalyst (preferably in two stages) at (71/29)-(99/1) ratio of the component (A) to pyrrole with <=10wt.%, preferably <=5wt.% residual amount of the component (C).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductive resin composition used for conductive rolls of electrophotographic copying machines and the like.

[Conventional technology]

In recent years, conductive polymer compositions that are highly processable, lightweight, and inexpensive have attracted attention, and it is believed that such conductive polymer compositions can be applied to a wide range of fields by taking advantage of the above characteristics. There is. However, most of the conventionally known conductive polymer compositions do not yet have sufficient stability of electrical properties to be used in the above fields. Here, the conductive polymer composition refers to a resin composition containing a conductive polymer such as polyacetylene, polypyrrole, or polythiophene in a matrix resin as a conductive material. For example, in JP-A No. 60-223854, the ratio (wt%) of the thermoplastic resin solution (A) and polypyrrole CB) is (
A conductive resin composition in which A)/(B)=70/30 to 20/80 is disclosed. This composition discloses a method of obtaining a conductive resin composition by, for example, causing the above mixed solution to act as a catalyst with an oxygen-containing oxidizing agent such as a peroxoacid salt to polymerize pyrrole.

[Problem that the invention seeks to solve]

However, the conductive resin composition obtained by the above method is in a conductive region and does not exhibit a semiconductive region because the catalyst exhibits conductivity (has the action of a doping agent). However, it is unstable (its electrical characteristics fluctuate widely and is highly dependent on the environment). As described above, the reality is that conventionally it has not been possible to obtain a material having an appropriate semiconducting region.

The present invention was made in view of the above circumstances, and an object thereof is to provide a semiconductive resin composition having stable electrical properties (low environmental dependence).

[Means for solving problems]

In order to achieve the above object, the semiconductive resin composition of the present invention is a resin composition in which polypyrrole is distributed in a matrix resin, and the remaining amount of oxidative polymerization catalyst for pyrrole polymerization is reduced by removing the catalyst. is set to less than 10%.

[Effect]

That is, the present inventors did not use a conductive resin composition, but
In order to obtain semiconductive resin compositions, we investigated the factors that cause changes in electrical properties. In the course of the research, the present inventors discovered that the oxidative polymerization catalyst for virole polymerization (which has an effect of imparting conductivity) contained in the resin composition has an effect on the stability of the electrical properties of the semiconductive resin composition. It turns out that it has a big impact. In other words, oxidative polymerization catalysts usually have deliquescent properties, and therefore, the electrical properties of semiconductive resin compositions in which such deliquescent catalysts remain will vary greatly due to the water absorption effect of the catalyst. (environmental dependence increases).

As a result of further research focusing on the content of this oxidative polymerization catalyst, we found that if the resin composition in which the catalyst remains is subjected to decatalyst treatment and the residual amount of the catalyst is reduced to below a certain value, the above-mentioned The inventors have discovered that it is possible to induce a resin composition into a semiconductive region and at the same time stabilize its electrical properties, and have arrived at this invention.

The semiconductive resin composition of the present invention is obtained using a matrix resin, a virol monomer, and an oxidative polymerization catalyst for virol polymerization.

Examples of the matrix resin include nylon 6-nylon 66-nylon 610 ternary copolymer nylon, N-methoxymethyl nylon, polymethyl methacrylate, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, and acrylonitrile. - Butadiene-styrene copolymer resin (ABS resin), polyolefin, polyvinylidene chloride, polyvinyl alcohol, thermoplastic resin such as polyether poly-2,5-phenyl ether, unsaturated polyester, epoxy resin, diallyl phthalate resin , silicone resin, thermosetting resin such as Polyurekne resin, and the like.

Examples of the virol monomer include virol itself (7) and others! 10-hyrol, N-alkylpyrrole, N-arylvirol, virol substituted with monoalkyl or dialkyl at the 3rd and 4th carbon positions, virol substituted with monohalogen or dihalogen at the 3rd and 4th carbon positions, etc. It will be done. In this invention, virol can be used alone or as a mixture of the virol monomer and other compounds. Optionally, other heterocyclic compounds such as furan, thiophene or thiazole may be used in place of some of the virol monomers.

The blending ratio (wt%) of the matrix resin (X) and polypyrrole (Y) is (X)/(Y) 71/29
It is preferable to set X+Y=100 within the range of 99/1. That is, if it is outside the above range, a semiconductive resin composition with excellent processability etc. cannot be obtained. Therefore, when blending each raw material, it is preferable to set the blending amount of the virol monomer so as to satisfy the above (X)/(Y) value.

The oxidative polymerization catalyst for the above-mentioned pyrrole polymerization includes metal chlorides such as iron, aluminum, copper, and platinum, persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate;
Redox catalysts such as inorganic peroxides such as potassium dichromate, persulfate-acidic sodium sulfite, hydrogen peroxide-ferrous salt, cumene hydroperoxide-ferrous salt, benzoyl peroxide-dimethylanilyl, etc. can be given.

The mixing ratio of the oxidative polymerization catalyst is preferably 0.5 to 4 moles per 1 mole of the pyrrole monomer.

Furthermore, in addition to the above raw materials, an organic solvent is used to mix and dissolve the above matrix resin, pyrrole monomer, and oxidative polymerization catalyst.

Examples of the organic solvent include methanol, ethanol, 2-
Examples include alcohols such as propatool, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, and dioxane, dimethyl sulfoxide, N,N'-dimethylformamide, N-methyl-2-pyrrolidone, acetonitrile, ethylene carbonate, and formic acid. , used alone or in combination.

The semiconductive resin composition of the present invention is produced using the above-mentioned raw materials, for example, in the following manner.

That is, first, a matrix resin is dissolved in an organic solvent, virol is added thereto, and the mixture is stirred at a temperature of -40 to 0°C. Next, a polymerization catalyst is added to this solution to polymerize virole, and then this polymerization solution is poured into water to coagulate the polymer and stop the reaction.

As a decatalyst treatment, the resulting polymer is immersed in clean water (about room temperature) for one to two days and nights. If necessary, the second step is room temperature to i o o
Immersion is continued for 1 to 7 days, preferably 3 days, in clean water of 'c', and the immersion is terminated when the OpH value on the surface of the polymer becomes approximately neutral. The amount of the oxidative polymerization catalyst remaining in the semiconductive resin composition that has been subjected to the decatalyst treatment in this manner must be set to 10% by weight or less, preferably 5% by weight or less. In other words, if the remaining amount of the oxidative polymerization catalyst exceeds 10 weight, the semiconductive resin composition will not only fail to reach the predetermined semiconductive range (104 to 101°Ω·c+++), but also will not have the effect of stabilizing the electrical properties. This is because it cannot be done. Usually, by performing the above-mentioned decatalyst treatment, particularly the second-stage decatalyst treatment, the remaining amount of the oxidative polymerization catalyst comes to fall within the above range.

Since the semiconductive resin composition obtained in this way has been subjected to a decatalytic treatment, it not only exhibits a predetermined semiconductivity, but also
Since the residual amount of the oxidative polymerization catalyst in the semiconductive resin composition is small, the electrical properties are stable (environmental dependence is reduced).

〔Effect of the invention〕

As described above, the semiconductive resin composition of the present invention has stable electrical properties (environmentally dependent ). Moreover, since the oxidative polymerization catalyst exhibiting conductivity in this semiconductive resin composition has been reduced by the decatalyst treatment, it is in an appropriate semiconductive region. Therefore, this semiconductive resin composition is suitable as a material for forming the surface layer of a conductive roll of an electrophotographic copying machine.

Next, examples will be described together with comparative examples.

[Example 1] Virol was added to a solution of 50 g of 6/66/610 ternary copolymerized nylon (manufactured by Toshi Co., Ltd., NI-80) polyurethane resin dissolved in methanol 325 at a ratio of 9% by weight of virol. The temperature was maintained at -20°C while stirring. Add 10% of a 2 molar aqueous solution of sodium beroxodisulfate to this solution.
0d was added dropwise over about 30 minutes while stirring at a stirring speed of 400 rpm. After 6 hours, the above polymerization solution is poured into water and coagulated to create a rubbery mass to stop the reaction, and after recovery, the rubbery mass that is the polymer is not left as it is, but is slightly loosened or spread thin to swell. It was made into a state where it could be easily washed and immersed in running water (temperature 60''C) for 72 hours.Next,
After air drying at room temperature for 24 hours, further drying at 50°C for 2
Vacuum drying was performed for 4 hours to obtain a semiconductive resin composition in the form of a rubber block. The recovery rate was 98%. The amount of residual catalyst was determined by measuring a test solution of the semiconductive resin composition prepared by the flask combustion method using an atomic absorption spectrometer. As a result, the residual catalyst (■) was 3.8% based on the matrix polymer. Further, the obtained semiconductive resin composition in the form of a rubber lump was dissolved in methanol (solvent), spread on a glass plate, and observed under a microscope. As a result, the average particle size of the polypyrrole in the composition was 0.
It was 4 μm. Next, the volume resistivity of the obtained semiconductive resin composition was measured (measurement conditions: high temperature (30°C
85RH%), low temperature and low humidity (10'CX 23RH%)
), and the influence on environmental dependence was investigated.

[Examples 2 and 3] The weight ratio of virol was changed to 13% and 17%. Other than that, a semiconductive resin composition was obtained in the same manner as in Example 1, and the amount of residual catalyst and environmental dependence were examined. The amount of remaining catalyst is 2.1 each.
%, 6.3%.

[Comparative Example 1] Decatalyst treatment (immersion in running water for 72 hours) was not performed. Other than that, a semiconductive resin composition was obtained in the same manner as in Example 1, and the amount of residual catalyst and environmental dependence were examined. The amount of remaining catalyst is 18
．． It was 7%.

(Comparative Example 2.3) Decatalyst treatment (immersion in running water for 72 hours) was not performed.Other than that, a semiconductive resin composition was obtained in the same manner as in Example 2, and the amount of residual catalyst and environmental dependence were examined. The remaining catalyst amounts were 20.3% and 21.2%, respectively.

The measurement results of environmental dependence obtained in this way are shown in the figure. The variation range A is as in Example 1. The variation range B is as in Example 2. The variation width C is as in Example 3. The fluctuation range is in Comparative Example 1, and the fluctuation range E is in Comparative Example 2. The fluctuation range F is the third comparative example.

From the above results, the range of variation in volume resistivity is smaller for all the implemented products than for the comparative products. Therefore, it can be seen that the electrical characteristics are stable and the environmental dependence is small.

[Brief explanation of the drawing]

The figure is a diagram showing the relationship between electrical characteristics depending on the presence or absence of decatalyst treatment. Patent applicant: Tokai Rubber Industries Co., Ltd. Agent: Yukihiko Nishifuji, patent attorney

Claims (1)

[Claims] (1) A resin composition in which polypyrrole is distributed in a matrix resin, characterized in that the residual amount of the oxidative polymerization catalyst for pyrrole polymerization is set to 10% by weight or less by decatalyzing. Semiconductive resin composition.