JPH0120655B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a conductive polycarbonate resin composition. Specifically, the present invention relates to a conductive polycarbonate resin composition that has excellent moldability and mechanical properties. Conductive plastics are useful as parts of electrical and electronic devices such as computers and copying machines, and polycarbonate resins are particularly promising because of their high heat resistance. It is known that carbon black is added to polycarbonate resin in order to make it conductive, but if the amount of carbon black is increased to improve conductivity,
The composition has a markedly reduced melt flowability, making it difficult to melt-knead and extrude using an extruder, or to mold by injection molding, and even if it can be molded, mechanical properties such as bending strength and impact resistance are significantly deteriorated. Only ivy molded products can be obtained. The present inventors have conducted intensive research to obtain a conductive polycarbonate resin composition with excellent moldability and mechanical properties, and have found that when blending a specific resin and carbon black with polycarbonate, moldability and mechanical properties are improved. can be greatly improved,
The present invention was completed based on the discovery that a molded article with excellent mechanical properties can be obtained. That is, the present invention aims to provide a conductive polycarbonate resin composition of great industrial value, and its gist is as follows: 95 to 50% by weight of aromatic polycarbonate resin, 1 aromatic polyester resin. ~40% by weight, 50-95 mol% of ethylene and α with 3 or more carbon atoms
- an ethylene copolymer obtained by copolymerizing 50 to 5 mol% of olefin; % or less of a modified ethylene copolymer obtained by graft polymerization, and 1 to 20% by weight of one or more rubbery resins selected from the group consisting of acrylic rubber. On the other hand, it is a conductive polycarbonate resin composition containing 5 to 40 parts by weight of carbon black. The present invention will be explained in detail below. The aromatic polycarbonate resin used in the present invention can be obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate. It is a polymer or copolymer, and a typical example is 2,2-bis(4-
Examples include polycarbonate resins made from hydroxyphenyl)propane (bisphenol A). As the dihydroxydiaryl compound,
In addition to bisphenol A, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis( 4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-
hydroxy-3-methylphenyl)propane,
1,1-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-
Bis(4-hydroxy-3,5 dibromophenyl)propane, 2,2-bis(4-hydroxy-
Bis(hydroxyaryl)alkanes such as 3,5 dichlorolphenyl)propane, 1,1-
Bis(hydroxyaryl)cycloalkanes such as bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxyphenyl ether, 4,4' -dihydroxy-3,
Dihydroxy diaryl ethers such as 3'-dimethyl diphenyl ether, dihydroxy diaryl ethers such as 4,4'-dihydroxy diphenyl sulfide, and 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfide. diaryl sulfides,
4,4'-dihydroxydiphenyl sulfoxide,
Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-
Examples include dihydroxydiarylsulfones such as dimethyldiphenylsulfone. These may be used alone or in combination of two or more, and in addition to these, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, etc. may be used in combination. Aromatic polyester resins are polyalkylene terephthalates obtained through the polycondensation reaction of terephthalic acid or its dialkyl esters with aliphatic glycols, or copolymers mainly composed of polyalkylene terephthalates. Examples include terephthalate and polybutylene terephthalate. Examples of the aliphatic glycols include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, etc. Along with these aliphatic glycols, small amounts of other diols or polyhydric alcohols,
For example, cyclohexanediol, cyclohexanedimethanol, xylylene glycol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-
Bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxyethoxyphenyl)propane, 2,2-bis(4-
Hydroxyethoxy-3,5-dibromophenyl)propane, glycerin, pentaerythritol, etc. may be used in combination. In addition, together with terephthalic acid or its dialkyl ester, a small amount of other dibasic acid, polybasic acid or its alkyl ester, such as phthalic acid, isophthalic acid, naphthalene dicarboxylic acid, up to 20% by weight relative to terephthalic acid or its dialkyl ester, Diphenyldicarboxylic acid, adipic acid, sebacic acid, trimesic acid, trimellitic acid, alkyl esters thereof, and the like may be used in combination. The ethylene copolymer obtained by copolymerizing 50 to 95 mol% of ethylene and 50 to 5 mol% of α-olefin having 3 or more carbon atoms used in the present invention can be obtained by copolymerizing the ethylene and α-olefin, for example. Examples include Ziegler-Natsuta catalysts, especially those copolymerized using vanadium compounds such as vanadium oxytrichloride and vanadium tetrachloride and organoaluminium compounds. Examples of α-olefins having 3 or more carbon atoms include propylene, 1-butene, 1-hexene, and 1-decene.
Examples include 1,4-methylbutene-1,4-methylpentene-1, propylene, butene-1, etc.
1 or a mixture thereof is preferred. The preferred amount of copolymerization of ethylene and the α-olefin is about 80 to 95 mol% of ethylene and 20 to 5 mol% of α-olefin. Ethylene copolymers suitable for use in the present invention have a crystallinity (determined by X-ray method as described in Journal of Polymer Science, Vol. 1955, pp. 17-26) of 75%. Below, preferably 1 to
Approximately 35%, melt index (ASTM D
1238 57T at 190°C) is about 0.01 to 50, preferably about 0.1 to 20. Examples of the above-mentioned ethylene copolymers include Tafmer A manufactured by Mitsui Petrochemical Industries, Ltd.
Tafmer A series (ethylene-butene-1 copolymer) such as 4085, A 4090, A 20090,
Tafmar P 0280, P0480, P 0680, P
Examples include Tafmer P series (ethylene-propylene copolymer) such as 0880. In addition, a modified ethylene copolymer obtained by graft polymerizing α,β-unsaturated carboxylic acid or its derivative to the ethylene copolymer in an amount of 1.5% by weight or less to the ethylene copolymer is It is produced by adding an α,β-unsaturated carboxylic acid or a derivative thereof to the mixture and performing graft polymerization by melt-kneading the mixture usually at 150 to 300°C. During this graft polymerization, α,α-bis-t-butylperoxy-
An organic peroxide such as p-diisopropylbenzene is added to the ethylene copolymer at a concentration of 0.001 to 0.05.
It may be used in an amount of about % by weight. Examples of α,β-unsaturated carboxylic acids and derivatives thereof include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, and anhydrides and esters of these acids. Among these, maleic anhydride is particularly preferred. The amount of the α,β-unsaturated carboxylic acid or its derivative to be graft-polymerized to the ethylene copolymer is 1.5% by weight or less, preferably 1% by weight or less. If this amount is too large, the modified ethylene copolymer will be easily decomposed, which may generate gas during molding and cause problems such as silver streaks. Furthermore, when a modified ethylene copolymer is used, an improvement in impact resistance is observed compared to when an ethylene copolymer is used. The amount of saturated carboxylic acid or derivative thereof is preferably 0.05% by weight or more, preferably 0.1% by weight or more. Acrylic rubber is produced by polymerizing acrylic esters,
or a rubber-like elastic body obtained by copolymerization mainly consisting of acrylic acid ester such as butyl acrylate,
Examples include rubber-like polymers obtained by graft polymerizing a graft polymerizable monomer such as methyl methacrylate to a polymer obtained by polymerizing a small amount of a crosslinkable monomer such as butylene diacrylate. Examples of the above-mentioned acrylic esters include buteracrylate, methyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and the like. In addition to butylene diacrylate, examples of crosslinking monomers include butylene dimethacrylate, polyols such as trimethylolpropane trimethacrylate, and esters of acrylic acid or methacrylic acid, divinylbenzene, vinyl acrylate, vinyl methacrylate, etc. The compounds include allyl compounds such as allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl itaconate, monoallyl maleate, monoallyl fumarate, and triallyl cyanurate. In addition, as the above graft polymerizable monomer,
In addition to methyl methacrylate, examples include methacrylic acid esters such as ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, styrene, acrylonitrile, and the like. A part of this graft polymerizable monomer can also be copolymerized by using it when producing a polymer by polymerizing the above-mentioned acrylic acid ester and a crosslinkable monomer. The above-mentioned acrylic rubbers include, for example, Kane Ace FM manufactured by Kanebuchi Chemical Co., Ltd., Vitax V-6401 manufactured by Hitachi Chemical Co., Ltd., Metablane W-300, Metablen W-530 manufactured by Mitsubishi Rayon Co., Ltd., Manufactured by Rohm and Haas, it is also commercially available as Acryloid KM-323, Acryloid KM-330, etc. There are no particular restrictions on the carbon black, but there are commercially available conductive carbon blacks such as Lion Akzo Co., Ltd., Ketsuen Black EC, Cabot Co., Ltd., and Vulcan XC-.
72, Denki Kagaku Kogyo Co., Ltd., Denka Acetylene Black, City Service Co., Ltd., Conductex SC
Carbon black, which is a by-product when producing synthesis gas containing hydrogen and carbon monoxide by partially oxidizing hydrocarbons such as naphtha in the presence of steam and oxygen, or carbon obtained by oxidizing this Examples include black, but
Among these, those with a specific surface area (low-temperature nitrogen adsorption method using the BET method) of 600 m ² /g or more, particularly 800 m ² /g or more are preferable, and oil absorption (amount of linseed oil adsorbed by 100 g of carbon black) is 200 ml. /100
gram or more, especially 250ml/100g or more is suitable. The preparation of the polycarbonate resin composition of the present invention can be carried out at any stage up to the production of the final molded article.
This can be achieved by blending the above-mentioned components by various means. For example, the above-mentioned components are mixed, melt-kneaded using an extruder, etc., and extruded to form pellets, and the above-mentioned resin components are melt-kneaded and extruded to form pellets, and carbon black is used when producing the final molded product. Examples include a method of blending, a method of melt-kneading carbon black with the above resin other than polycarbonate resin, and then blending polycarbonate resin.
A molded product with superior mechanical properties can be obtained by a compounding method in which there is less direct contact between the polycarbonate resin and carbon black, so carbon black is melt-mixed with a resin other than polycarbonate resin and then compounded with the polycarbonate resin. The method of doing so is preferable. The conductive polycarbonate resin composition of the present invention includes 95 to 50% by weight of aromatic polycarbonate resin,
Preferably 85 to 55% by weight, aromatic polyester resin 1 to 40% by weight, preferably 5 to 38% by weight, ethylene copolymer, modified ethylene copolymer,
and 1 to 20% by weight of one or more rubbery resins selected from the group consisting of acrylic rubber,
5 to 40 parts by weight, preferably 7 to 35 parts by weight of carbon black per 100 parts by weight of the resin mixture, preferably 2 to 15% by weight.
It is a combination of. In the conductive polycarbonate resin composition of the present invention, if the amount of the aromatic polycarbonate resin is too large, the blending of carbon black will significantly reduce the melt fluidity and the mechanical properties of the molded article. Conversely, if the amount is too small, the heat resistance and mechanical properties of the polycarbonate resin will be impaired. If the amount of the aromatic polyester resin is too large, it will tend to deteriorate during melt molding and the mechanical properties of the molded product will deteriorate. On the other hand, if the amount is too small, the melt fluidity and mechanical properties will be greatly reduced. If the amount of rubbery resin is too large, it may cause problems such as deterioration of the surface condition of the molded product, such as peeling on the surface of the molded product, or worsening of heat resistance and yellowing of the molded product. On the other hand, if the amount is too small, the effect of improving impact resistance will be reduced. The rubbery resin is one or a combination of two or more selected from the group consisting of the above-mentioned ethylene copolymer, modified ethylene copolymer, and acrylic rubber, and usually the amount in the resin mixture is , ethylene copolymer or modified ethylene copolymer should be used in an amount of about 1 to 10% by weight, preferably about 2 to 8% by weight, and acrylic rubber should be used in an amount of about 0 to 10% by weight, preferably about 2 to 8% by weight. . If the amount of carbon black is too large, the melt fluidity will decrease and it will be impossible to obtain a molded article with excellent mechanical properties. On the other hand, if it is too small, a product with sufficient conductivity cannot be obtained. The composition of the present invention can be molded into articles of various shapes by various molding methods such as extrusion, injection, and compression. Molded articles produced from the composition of the present invention are lightweight and have excellent conductivity and mechanical properties, so they are useful as industrial materials for electrical, electronic devices, automobiles, aircraft, and other industrial materials in place of metals. EXAMPLES The present invention will be specifically explained below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the examples, "parts" and "%" indicate "parts by weight" and "% by weight," respectively. In addition, bending strength is ASTM D 790, Izod impact strength is ASTM D 256, and volume resistivity is
Values measured according to ASTM D 46-54T. Production example of modified ethylene copolymer Ethylene-butene-1 copolymer with a crystallinity of 20%, a melt index of 3.6, and a butene-1 content of 14 mol% (Mitsui Petrochemical Co., Ltd., Tafmer A20090) 100
α,α′-bis-t dissolved in a small amount of acetone
0.025 part of -butylperoxy-p-diisopropylbenzene and 0.5 part of maleic anhydride are blended in a Henschel mixer and the blend is
The mixture was melt-kneaded and extruded at 230°C using a 40 mm extruder, and pelletized to obtain a modified ethylene copolymer. A portion of this pellet was crushed, unreacted maleic anhydride was extracted with acetone, and after press molding, maleic anhydride was quantified by infrared spectroscopy, and it was found that 0.37% of maleic anhydride had undergone graft polymerization. . Example 1 and Comparative Examples 1 to 2 24 parts of polyethylene terephthalate (manufactured by Mitsubishi Chemical Industries, Ltd., Novapet 1075B) with an intrinsic viscosity of 0.75,
6 parts of acrylic rubber (Acryloid FM-330, manufactured by Rohm & Haas), 3 parts of the modified ethylene copolymer produced in the above production example, and 15 parts of carbon black (Ketsutien Black EC, manufactured by Lion Akzo Co., Ltd.) The mixture was melt-kneaded at 240°C using a 40 mm extruder and extruded into pellets. Polycarbonate (manufactured by Mitsubishi Chemical Corporation, Novarex) with an average molecular weight of 23,500 was added to the pellets.
7025A) Blend 67 parts and use a 40mm extruder
The mixture was melt-kneaded at 280°C and extruded into pellets.
This melt-kneading extrusion could be performed smoothly. This pellet was molded at a resin temperature of 280°C and a mold temperature of 80°C using a 3.6 oz injection molding machine (IS-75S manufactured by Toshiba Machinery Co., Ltd.) and a test piece mold specified by ASTM. The bending strength, Izot impact strength and volume resistivity of the molded product obtained were as shown in Table 1 below. In addition, when blending only polycarbonate with carbon black, polycarbonate 100
Even with 5 parts of carbon black per 1 part of carbon black, the extruded strands were brittle and stable melt-kneading was difficult, but injection molding was performed using the obtained pellets. The properties of this molded product are shown in Comparative Example 1 in Table 1 below.
It was as shown in. Furthermore, when carbon black is blended with a resin mixture consisting of 97 parts of polycarbonate and 3 parts of the above-mentioned modified ethylene copolymer, carbon black
Melt-kneading extrusion is possible at 10 parts or less, but
The properties of a molded article obtained by injection molding using a pellet obtained by blending 10 parts of carbon black were as shown in Comparative Example 2 in Table 1 below.

[Table] Example 2 The same polycarbonate, polyethylene terephthalate, acrylic rubber, and carbon black used in Example 1 were mixed with 67 parts, 24 parts, 6 parts, and 15 parts, respectively, and an ethylene copolymer (Mitsui Petrochemical Co., Ltd.).
Blend 3 parts of Tafmer A20090 (manufactured by Co., Ltd.) and 40
The mixture was melt-kneaded and extruded into pellets at 280°C using a mm extruder. The pellets were injection molded as in Example 1. The molded product obtained had a bending strength of 620 Kg/cm ² , an Izod impact strength of 15 Kg·cm/cm, and a volume resistivity of 5×10 ³ Ω·cm.

Claims (1)

[Scope of Claims] 1. 95-50% by weight of aromatic polycarbonate resin, 1-40% by weight of aromatic polyester resin, ○ 50-95% by mole of ethylene and α having 3 or more carbon atoms.
- an ethylene copolymer obtained by copolymerizing 50 to 5 mol% of olefin; % or less of modified ethylene copolymer obtained by graft polymerization, and one or more rubber-like resins selected from the group consisting of acrylic rubber.
A conductive polycarbonate resin composition comprising 5 to 40 parts by weight of carbon black per 100 parts by weight of a resin mixture consisting of % by weight.