Patent GB-781774-A (GB)
Title: Improvements in or relating to antistatic rubber compositions
Inventor: BULGIN DOUGLAS
IPC: C08K5/17
Filed: 1954-09-04
Abstract: The electrical conductivity of synthetic rubber compositions is increased by incorporating therein, or in surface layers thereof, one or more tertiary amines containing at least one polyoxyalkylene group and at least one long-chain aliphatic radical, or quaternary salts thereof.  The synthetic rubber may comprise poly-isobutylene or a copolymer of butadiene with styrene, acrylonitrile, isobutylene, or isoprene.  The amine is preferably of the formula R-N[R1O)mH]2, wherein R represents a longchain aliphatic radical, e.g. an alkyl or alkenyl group containing 8 or more carbon atoms such as a caprylyl, oleyl, lauryl, myristyl, stearyl or cetyl radical, m has a value from 1 to 50 and R1 represents the group (CH2)p, where p is an integer greater than 1 such as an ethylene or propylene group.  The preferred quaternary salt has the formula RR11N4[(R1O)mH]2,X-, wherein R11 represents an alkyl, such as methyl, butyl or cetyl, alkenyl, or aryl group and X represents an acid radical such as a chlorine, bromine or CH3SO4 ion.  Up to 20 per cent by weight of the compound or mixture may be incorporated in the rubber mix during the preparation of the rubber composition. Alternatively the compound or mixture may be absorbed into the rubber composition if soluble in rubber or in a compounding ingredient thereof.  The absorption may be aided by heating or by applying the compound or mixture in a volatile solvent which has a swelling action on the rubber.  The synthetic rubber compositions may contain electrically conductive carbon black and may be vulcanized.  They may be used for tyres, flooring and conveyer belting.ALSO:The electrical conductivity of a natural or synthetic rubber composition is increased by incorporating therein, or in a surface layer thereof, a tertiary amine containing at least one polyoxyalkylene group and at least one long chain aliphatic radical, or a quaternary salt thereof.  The amine is preferably of the formula R-N [(R1O)mH]2, wherein R represents a long-chain aliphatic radical, e.g. an alkyl or alkenyl group containing 8 or more carbon atoms, m has a value from 1 to 50 and R1 represents the group (CH2)p, where p is an integer greater than 1.  The preferred quaternary salt has the formula R R11 N+[R1O)mH]2,X-, wherein R11 represents an alkyl, alkenyl, or aryl group and X represents an acid radical. Particularly suitable compounds are those in which R is a caprylyl, oleyl, lauryl, myristyl, stearyl or cetyl radical, R1 is an ethylene or propylene group, m has a value between 1 and 12, R11 is an alkyl group such as methyl, butyl or cetyl and X is a chlorine, bromine or CH3SO4 ion. The compounds may be used singly or in combination and there is preferably used a mixture of closely related homologous compounds of the average composition (C17H33)N [C2H4O)4,5H]2 or the quaternary salts of the average composition: (C17H33)(CH3)N [(C2H4O)4,5H]2, CH3SO4 Up to 20 per cent by weight of the compound or mixture is incorporated in the rubber mix during the preparation of the rubber composition.  Alternatively the compound or mixture may be absorbed into the rubber composition if soluble in rubber or in a compounding ingredient thereof.  The absorption may be aided by heating or by applying the compound or mixture in a volatile solvent which has a swelling action on the rubber.  The natural or synthetic rubber composition may contain electrically conductive carbon black.  The synthetic rubber may comprise polyisobutylene or a copolymer of butadiene with styrene, acrylonitrile, isobutylene, or isoprene.