Patent Number: 047044136
Section: claims

1. A resin composition having an electromagnetic wave shielding effect, comprising: 35 to 90 wt% of a copolymer of an ethylenic unsaturated nitrile, a diene rubber and an aromatic vinyl compound or a mixture of said copolymer with another copolymer of an ethylenic unsaturated nitrile and an aromatic vinyl compound;  1 to 25 wt% of a plasticizer;  an electrically conductive filler consisting essentially of 5 to 25 wt% of carbon fibers with metallized surfaces; and 2 to 30 wt% of carbon black. 2. The resin composition according to claim 1, wherein said ethylenic unsaturated nitrile is selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile and methyl methacrylonitrile, said diene rubber is selected from the group consisting of butadiene, isoprene, 2-chloro-1,3-butadiene, 1-chloro-1,3-butadiene, piperylene and mixtures thereof, and said aromatic vinyl compound is selected from the group consisting of styrene, .alpha.-methylstyrene, vinyltoluene, divinylbenzene, chlorostyrene and mixtures thereof. 3. The resin composition according to claim 1, wherein said copolymer of said ethylenic unsaturated nitrile, said diene rubber and said aromatic vinyl compound is a graft copolymer prepared by graft-copolymerizing 20 to 75 parts by weight of a diene rubber or a diene-containing polymer containing not less than 50 wt% of diene rubber with 80 to 25 parts by weight of a mixture of an ethylenic unsaturated nitrile and an aromatic vinyl compound. 4. The resin composition according to claim 1, wherein said composition is a mixture of 25 to 99 parts by weight of said copolymer of said ethylenic unsaturated nitrile, said diene rubber and said aromatic vinyl compound and 1 to 75 parts by weight of said another copolymer of the ethylenic unsaturated nitrile and the aromatic vinyl compound. 5. The resin composition according to claim 1, wherein said plasticizer is selected from the group consisting of phthalic acid esters, fatty acid esters, epoxides, phosphoric acid esters, ethers, polyesters and chlorinated plasticizers. 6. The resin composition according to claim 5, wherein said phthalic acid esters are one or more of dibutyl phthalate and di-2-ethylhexyl phthalate; said fatty acid esters are one or moe of di-2-ethylhexyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate and di-2-ethylhexyl azelate; said epoxides are one or more of epoxidized fatty acid monoesters, epoxidized soybean oil and epoxidized linseed oil; said phosphoric acid esters are one or more of tricresyl phosphate, tri-2-ethylhexyl phosphate and tributoxyethyl phosphate; said ethers are one or more of triethyleneglycol di-2-ethyl butylate, dibutylcarbitol adipate and dibutylcarbitol formal; said polyesters are one or more of adipic acid polyesters, sebacic acid polyesters and azelaic acid polyesters; and said chlorinated plasticizers are one or more of chlorinated aliphatic esters and chlorinated paraffins. 7. The resin composition according to claim 1, wherein said plasticizer is selected from the group consisting of flame-retarding plasticizers of phosphoric acid derivatives and ethylene/propylene terpolymers. 8. The resin composition according to claim 7, wherein said flame-retarding plasticizers are selected from the group consisting of tri(2-ethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, isodecyl diphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, mixed aryl phosphates, phenyl/isopropyl phenyl phosphate, mixed triaryl phosphates and tris(chloroethyl) phosphate. 9. The resin composition according to claim 7, wherein said terpolymer has a composition containing 50 to 80 mol% of ethylene, 20 to 50 mol% of propylene and 0.5 to 10 mol% of an unsaturated compound having a double bond. 10. The resin composition according to claim 9, wherein said unsaturated compound is selected from the group consisting of 1,4-hexadiene, dicyclopentadiene and ethylidene norbornene. 11. The resin composition according to claim 1, wherein each of said carbon fibers has a length of 0,.5 to 20 mm and a diameter of 3 to 25.mu. and said carbon fibers have a bundle count of 1,000 to 20,000. 12. The resin composition according to claim 1, further comprising 0.5 to 10 wt% of an alkylamine antistatic agent. 13. The resin composition according to claim 12, wherein said alkylamine antistatic agent is an amine compound having hydroxyethyl groups and represented by the following formula of: ##STR2## wherein R.sub.1 is an alkyl or alkenyl group having 8 to 22 carbon atoms, and m and n are integers of 1 to 10. 14. The resin composition according to claim 13, wherein said amine compound is selected from the group consisting of N,N-bis( 2-hydroxyethyl) tallow amine, polyoxyethylene lauryl amine and fatty acid esters of polyoxyethylene lauryl amine. 15. The resin composition according to claim 1, further comprising 2 to 35 wt% of a halogen-containing organic flame retarder and 0.4 to 21 wt% of an auxiliary flame-retarding agent, the amount of added auxiliary flame-retarding agent being 6/10 to 2/10 of the weight of said halogen-containing organic flame retarder. 16. The resin composition according to claim 15 wherein said halogen-containing organic flame retarder is selected from the group consisting of chlorinated paraffins, tetrabromobisphenol-A and oligomers thereof, decabromobiphenyl ethers, hexabromobiphenyl ethers, pentabromobiphenyl ethers, pentabromotoluene, pentabromoethylbenzene, hexabromobenzene, pentabromophenol, tribromophenol derivatives, perchloropentanecyclodecane, hexabromocyclododecane, tris(2,3-dibromopropyl)-1)isocyanurate, tetrabromobisphenol-S and derivatives thereof, 1,2-bis(2,3,4,5,6-pentabromophenoxy)ethane, 1,2-bis(2,4,6-tribromophenoxy)ethane, brominated styrene oligomers, 2,2-bis-(4-(2,3-dibromopropyl)-3,5-dibromophenoxy)propane, tetrachlorophthalic anhydride, tetrabromophthalic anhydride and mixture thereof. 17. The resin composition according to claim 15, wherein said auxiliary flame-retarding agent is selected from the group consisting of antimony trioxide, sodium antimonate, zinc borate, and oxides and sulfides of zirconium and molybdenum. 18. The resin composition according to claim 1, further comprising any one or more of antioxidants, internal and external lubricants, and stabilizers.