GB1410005A - Polyamide - Google Patents

Abstract

1410005 Polyamides BP CHEMICALS INTERNATIONAL Ltd 15 Sept 1972 [15 Sept 1971] 42967/71 Heading C3R A polyamide contains acid residues, more than 80 mol. per cent of which are residues of an aromatic or alicyclic acid wherein n = 0 or 1 and the ring is unsubstituted or substituted by methyl, and amine residues which comprise residues of (I) between 10 and 80 moles per cent of optionally methyl-substituted m- or p-xylylene diamine and (II) over 20 and up to 90 moles per cent of an aliphatic diamine wherein q, s, t, u and w are integers totalling not more than 14 and R<SP>1</SP> to R<SP>4</SP> are each H or methyl with at least 2 on the same carbon atom being methyl. It may also contain up to 30 mol. per cent of (III) residues of a diamine wherein R 5 and R 6 are H or methyl and x+y+z #12. It is preferred that not more than 10 mol. per cent of residues of any other diamine is present. Specified acids are terephthalic, 1,4- phenylene diacetic and 1,4-cyclohexane dicarboxylic and diacetic acids as the essential acids, and adipic, suberic, sebacic, dodecane dioic, isophthalic, 1,2- or 1,3-cyclohexanol dicarboxylic or diacetic, and 1,2- or 1,3-phenylene diacetic acids as optional acids. Specified diamines are (II) 2,2,4- and 2,4,4-trimethyl hexamethylene diamine, 2,2,7,7-tetramethyl octamethylene diamine and 2,2-dimethyl pentamethylene diamine, and (III) hexa- and dodecamethylene, 5-methyl nonane 2-methyl pentamethylene, and 2- or 3-methyl or 2,5-dimethyl hexamethylene diamines. Up to 10 mol. per cent of residues of amino-acids or their lactams may also be present, e.g. capro- or lauro-lactam or #-amino hexanoic, undecanoic or dodecanoic acids. Conventional additives such as stabilizers, e.g. the stearyl ester of 3-(4-hydroxy-3,5-di-tbutylphenyl) propionic acid, triphenyl, diethyl hexyl or trisnonyl phosphite or ammonium hypophosphite, and plasticizers, e.g. N-butyl benzene sulphonamide, may be incorporated with the polymer during or after its preparation. In all the specific examples the acid is terephthalic, diamine (I) is a mixture of 70% meta, 30% para-xylylene diamines and (II) is a 50/50 mixture of 2,2,4- and 2,4,4-trimethyl hexamethylene diamines; some also include units of hexa- or dodeca-methylene diamine or caprolactam. It is stated that the selected combination of acid and amine residues in the specified proportions provides polyamides having a high impact strength, generally of at least 44 k JM<SP>-2</SP> while retaining good overall mechanical properties. Reference is made to Specifications 905,475; 1,176,985; 1,225,483 and 1,128,761.