JPH02196854A - Conductive resin support for electrophotographic photoreceptors - Google Patents

Abstract

PURPOSE:To provide a composition having wholly improved mechanical characteristics, processability and appearance while maintaining a high conductivity and suitable for preparing the substrates of electrophotographic sensitive materials by comprising an aromatic polycarbonate, an aromatic polyalkylene terephthalate and a specific carbon black. CONSTITUTION:A conductive resin composition comprises (A) a thermoplastic aromatic polycarbonate in an amount of 60-98wt.% based on the sum of the components A and B, (B) a thermoplastic polyalkylene terephthalate in an amount of 40-2wt.% based on the sum of the component A and B and (C) a carbon black selected from super conductive furnace black (SCF), conductive furnace black (CF), extra conductive furnace black (XCF) and super abrasion furnace black (SAF) in an amount of 3-20 pts.wt. per 100 pts.wt. of the sum of the components A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a conductive resin composition, particularly a conductive resin composition that has excellent mechanical properties, moldability, and appearance, and is suitable as a conductive support for an electrophotographic photoreceptor. The present invention relates to a synthetic resin composition.

[Prior Art J Conventionally, conductive resins have been used in various fields such as antistatic and electrostatic accident prevention. However, the conductivity required in these fields is low, and in fields where high conductivity, excellent mechanical properties, and moldability are required, there is still no conductive resin that satisfies these requirements.For example, Conventionally, in electrophotographic photoreceptor conductive supports,
Metals such as aluminum were used.

When substituted with plastic, a resin composition based on aromatic polycarbonate is known as one that can provide high conductivity and has excellent EW characteristics and moldability.

[Problems to be Solved by the Invention] However, in order to impart high conductivity to aromatic polycarbonate resin, conductive fillers such as carbon black must be blended at extremely high concentrations. Mechanical properties of group polycarbonates,
There are problems such as a marked decrease in molding processability, or an extremely poor appearance of the resulting product, and problems with the adhesion of the photosensitive layer to the surface. It was difficult to use.

[Means for Solving the Problems] The present inventors have solved the problems of highly conductive resin compositions, such as mechanical properties, moldability, product appearance, etc., while maintaining high conductivity. As a result of intensive research, we focused on the combination of aromatic polycarbonate and polyalkylene terephthalate and solved the above problem by using a unique carbon black.

That is, the conductive resin composition according to the present invention can be used for (a)
A thermoplastic resin composition characterized by comprising (C), 60 to 98% by weight of (a) based on (a) + (b), (
b) in an amount of 40 to 2% by weight based on (a) + (b), and (c) in an amount of 3 to 2% by weight based on (a) + (b) loo parts by weight.
This is a conductive resin composition containing 20 parts by weight.

(a) Thermoplastic aromatic polycarbonate (b) Thermoplastic polyalkylene terephthalate (C) Super conductive furnace black (SCF), contactive furnace black (CF), extra conductive furnace black (XCF) and super conductive furnace black (SCF) Brasion Furnace Black (SAF)
DETAILED DESCRIPTION OF THE INVENTION The conductive resin composition obtained by the present invention includes at least one type of carbon black selected from the following.

It is basically composed of various thermoplastic resins and conductive carbon black.

Tsutomu Polycarbonate Aromatic polycarbonate, which is one of the two types of thermoplastic resins used in the present invention, is one in which at least the majority of the dihydroxy compounds that should constitute the carbonate ester have two phenolic hydroxyl groups. be. Specific examples of such dihydric phenols include bisphenols, particularly bisphenol A.

Aromatic polycarbonates are produced by reacting the above-mentioned "dihydric phenols" with carbonate precursors such as phosgene, bistaroloformates, carbonic diesters, etc., but in the present invention, suitable polycarbonates can be obtained from commercially available products. can do.

Plastic Polyalkylene Terephthalate Polyalkylene terephthalate (FAT), which is another type of thermoplastic resin used in the present invention, has a glycol component that should constitute an alkylene component such as ethylene glycol,
Triethylene glycol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, 2
．． 2.4. Those consisting of aliphatic dioxy compounds such as 4-tetramethylene glycol are generally targeted. Among these, the most preferred dioxy compounds are ethylene glycol and butylene gelcol, but mixtures containing up to 40 mol% of other dioxy compounds are also preferred.

On the other hand, the terephthalic acid component of this PAT is most preferably composed only of terephthalic acid, but if desired,
Up to mol % may be replaced by other dicarboxylic acids, especially aromatic dicarboxylic acids, such as isophthalic acid.

Preferred PATs in the present invention are polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).
), but PBT is particularly preferred. PET,
Various types of FAT are available on the market, including PBT.

Carposi Black The carbon black used in the present invention is preferably one that can impart the necessary conductivity to the composition with a small amount added. Specifically, furnace black has few dull substances, and
Among them, furnace black X CF IExtracondu is preferable because it has excellent conductivity.
active Furnace Black)S CF
(Super Conductive Furnace
Black) CF (Conductive Furn)
ace BlacklJ5 and 5AF (Super A
Brasion Furnace Blackl is applicable.

Among them, the BET specific surface area due to N2 adsorption is 800 m”
XCF of 7 g or more is preferable. Examples of XCF include "Ketchen Black E CJ" from Ketsch En Black International, and "Palcan xC" from Cabot.

72], and SCFs include Cabot's Palcan SCJ and Palcan P, Degussa's Corax L, and CFs include Cabot's Palcan CJ and Co1oua+bian's Conductex SCJ. SAFs include "Asahi #9" by Asahi Carbon Co., Ltd., "Diablack AJ" by Mitsubishi Chemical Industries, Ltd., and "Pulcan 9" by Cabot. These carbon blacks may be used in combination, and if these carbon blacks are the majority, and the carbon black as a whole has a BET specific surface area due to N2 adsorption of 750 ■''/
g or more, preferably 800 ts"7 g or more, especially 90 ts"
Other carbon blacks such as acetylene black may be used in combination as long as the carbon black is 2"/g or more.

The conductive resin composition of the present invention may contain various additional components that are normally incorporated into resin compositions, as long as they do not particularly impede the properties aimed at by the present invention. Examples of such components include antioxidants, lubricants, mold release agents, and the like.

In the conductive resin composition of the present invention, the above-mentioned components are blended in the following proportions.

(a) Thermoplastic aromatic polycarbonate: (a) +
(b) 60-98% by weight, preferably 80-97% by weight
Weight% (b) Thermoplastic PAT: 40 to 3% by weight, preferably 20 to 3% by weight based on (a) + (b) (Cl carbon black: 1a above) ÷ [3 to 20% by weight based on 100 parts by weight of bl parts by weight, preferably 4 to 15 parts by weight In the above formulation, if component (a) or (b) is out of the above range, the electrical conductivity will be 10''0011 or more, which is undesirable. When the amount is less, the conductivity becomes 10"0 cm or more, which is not preferable. On the other hand, when it is more than the above range, the moldability and appearance deteriorate.

The above-mentioned components can be made into pellets by applying a conventional melt mixing method, ie, a screw extruder, a twin screw extruder, a roll extruder, a Banbury, etc.

When this crosstalk occurs, it is necessary to sufficiently control the moisture content of each component. The water content of each component is 0.5% by weight or less, preferably 0.2% by weight or less, especially 11000% by weight or less.
It is preferable that it is less than pp.

If the water content exceeds 0.5% by weight, it may adversely affect the appearance of the product. It is necessary to pay attention to this water content when storing the composition after production, and it is preferable to suppress the water content of the composition itself to 0.5% by weight or less. For this reason, hot air drying or Measures such as vacuum drying are employed.

[Example J In the following Examples and Comparative Examples, various evaluation measurements were performed by the following methods.

(1) Conductivity (specific resistance: 0 cm) Measured according to SRIS standard 2301-1969 Wheatstone Bridge method, and evaluated based on the obtained specific resistance value.

Less than 1OΩ·C■ was rated as OI, and more than that was rated as ×.

(2) Tensile strength 1kg/kaku, 21), elongation (%) J
Compliant with IS K-6758.

Tensile strength is 6 kg/■-2 or more and elongation is 1
% or more but less than 3% was evaluated as 0, and anything else was evaluated as ×.

(3) Molding processability (MFR: g710 min) JIS K-
7210-1975, 280°C, 2.16-k
The VFR at g load was determined.

0.1 g/10 minutes or more was evaluated as ○, and less than 0.1 g/10 minutes was evaluated as ×.

(4) Appearance T-die sheet formation Jf2m The surface unevenness of the sheet molded with less than 5 μm was evaluated as ◯, and other than that [− was evaluated as ×].

(5) Electrophotographic characteristics (cm2/mJ) On a conductive resin sheet, metal-free phthalocyanine treated by an acid paste method was formed into a film with a thickness of 3 μm as a charge-69 generating agent, and then further A photoreceptor was prepared by forming a photosensitive layer by depositing 30 g of p-diethylaminobenzaldehyde (diphenylhydrazone) as a charge transfer agent.

The obtained photoreceptor was corona charged using a stub-ink method at a voltage of -6 kV, kept in a dark place for 1 υ seconds, and the initial surface potential was measured by xenon lamp light using a monochromator. The rB color photoreceptor is irradiated with 780nm spectroscopy, and the time it takes for its surface potential to decay steadily is 1771.
(seconds), and the exposure amount (cm'/mJl) was calculated.

Those whose exposure meter measured 100 cm 2 /mJ or more and those whose values were less than 05 were evaluated as ×.

Example 1 Melt flow rate (MFR): 4.6 g 710 minutes (280°C) Polycarbonate (Niepilon E-20fIO manufactured by Mitsubishi Gas Chemical ■) 94.5@Motobe, MFR: 4.32r: 710 minutes (280°C) ℃) polybutylene terephthalate (Tubadol 5F120 manufactured by Ryo Kasei) 5.5
, ;TilR part, and specific surface area 'J 00 m /
Ketchen Black EC (manufactured by Ketchen Black International Co., Ltd.) 111rj+1 of g was mixed using a vented twin-screw extruder. 12 were kidnapped.

i') The resulting pellets were made into a sheet with a thickness of about 11 using a die sheet molding machine, and the conductivity, tensile strength, IN tensile strength and elongation, formed JFg, Tability, and external %M of the rolled sheet were evaluated. Rated one for each.

In addition, the photographic α characteristics of the photoreceptor obtained by forming a photosensitive layer on the conductive sheet and preparing the photoreceptor were evaluated.

These 7IlII fixed values and evaluations are shown in Table 1.

Comparative Example 1 A resin composition No. 11 was prepared in the same manner as in Example 1 except that polystyrene ("Dialex Kido 77" manufactured by Mitsubishi Monsanto ■) was used in place of polybutylene terephthalate. Various evaluations are shown in Table 1.

Comparative Example 2 A resin composition was prepared in the same manner as in Example 1, except that acetylene black (-: 3250 manufactured by Ryo Kasei Corporation) with a specific surface area of 70 m2/g was used in place of Wutzchen black EC. I got it. The -' value results for this product are shown in Table 1.

Comparative Example 3 In Example 1, the blending amount of Ketchen Black was 25%.
A resin composition was obtained as 1f m parts. The evaluation results of this product are shown in Table 1.

Table 1 [Effects of the Invention] The conductive thermoplastic resin composition of the present invention has a conductive carbon black and a specific two l! By melting and kneading a Type 1 thermoplastic resin, a relatively small amount of conductive carbon black is blended to give the thermoplastic resin high conductivity (volume resistivity = 10
2 Ωcm), excellent mechanical properties, and moldability. Such an effect makes it possible to use a conductive thermoplastic resin as the crosspiece λ made of metal aluminum or the like, especially as the conductive support for the photoreceptor of the electrophotographic 11.

Claims (1)

[Claims] (1) A thermoplastic resin composition characterized by consisting of the following (a) to (c), in which (a) is replaced by (a) + (b).
60 to 98 weight % based on the standard, 40 to 2 weight % based on (a) + (b) of (b), and 3 to 20 parts by weight of (c) based on 100 parts by weight of (a) + (b). conductive resin composition. (a) Thermoplastic aromatic polycarbonate (b) Thermoplastic polyalkylene terephthalate (c) Super conductive furnace black (SCF), conductive furnace black (C
F) at least one carbon black selected from Extra Conductive Furnace Black (XCF) and Super Appreciation Furnace Black (SAF)