Patent GB-578966-A (GB)
Title: Improvements in the preservation of rubber compositions
IPC: C08K5/18
Filed: 1943-11-24
Abstract: Anti-oxidants for incorporation in natural or artificial rubber compositions of the general formula <FORM:0578966/IV/1> wherein "aryl" and "arylene" each represent a benzene, naphthalene or biphenyl nuclear residue, optionally containing as substituents alkyl, aryl, aralkyl, alkenyl, alkoxy, aryloxy, alkenyloxy, secondary or tertiary alkylamino, secondary arylamino or alkylmercapto radicals, or halogenatoms, are obtained by treating with phosgene the sodium salt of the corresponding phenolic derivative in solution or suspension in an appropriate liquid medium, e.g. water, acetone, dioxane, benzene, carbon tetrachloride, chloroform or ether.  The products from a mixture of arylamino phenols, e.g. a mixture of phenylamino cresols, are unsymmetrical.  In other cases, there are obtained symmetrical diaryl carbonate derivatives such as the 4 : 41-di-(phenylamino)-, 3 : 31-(phenylamino)-, 2 : 21-di-(phenylamino)-, 4 : 41-di-(b -naphthylamino)-, 4 : 41-di-(p-biphenylamino)-, 3 : 31-di-(p-tolylamino)-, 4 : 41-di-(o-tolylamino)-, 4 : 41-di-(p - benzylphenylamino)-, 4 : 41 - di - (phenylamino) - 2 : 21 - dimethyl-, 3 : 31-di-b -naphthylamino) - 2 : 21 - dichloro-, 4 : 41 - di - (p - anisylamino)-4 : 41 - di - (p - phenetylamino)-, 4 : 41 - di - (p - biphenylamino)-, 3 : 31 - dibromo-, 3 : 31 - di - (phenoxyphenylamino)-, 4 : 41-di-(p-allyloxy - phenylamino)-, 2 : 21-di-(p-chlorophenylamino)-, 4 : 41 - di-(p-phenylaminophenylamino)-, 3 : 31-di - (m - phenylaminophenylamino)-, and 4 : 41 - di-(p-dimethylaminophenylamino)-, derivatives of diphenylcarbonate, 4 : 41-diphenylamino-di-a -naphthyl carbonate, 4 : 41-di-(p-tolylamino)-di-b -naphthyl carbonate and 4 : 41-di-b -naphthylamino-2 : 21-diphenyl diphenyl carbonate.  In examples: (1) 4 : 41-diphenylamino-diphenyl carbonate is prepared by adding 4-hydroxydiphenylamine to sodium ethoxide solution and treating the ice-cooled suspension in acetone with phosgene; (2) 4 : 41-di-b -naphthylaminodiphenyl carbonate is prepared by adding sodium to p-hydroxyphenyl-b -naphthylamine in acetone and treating the stirred mixture with phosgene at 10 DEG  C.ALSO:Natural or artificial rubber compositions of all types, including polychoroprene, olefine polysulphides, butadiene polymers, Buna N and Buna S (the word "Buna" being a Registered Trade Mark), and reclaims and latices of such compositions, are preserved by incorporating therein as antioxidants, with or without other desired filling and compounding ingredients, carbonates of the general formula:-  <FORM:0578966/V/1> wherein "aryl" and "arylene" each represent a benzene naphthalene or biphenyl nuclear residue, optionally containing as substituents alkyl, aryl, aralkyl, alkenyl, alkoxy, aryloxy, alkenyloxy, secondary or tertiary alkylamino, secondary arylamino or alkylmercapto radicals or halogen atoms.  The antioxidants may suitably be incorporated in proportions of from 0.1 to 5 per cent.  Specified diaryl carbonate derivatives used are the 4 : 41-di(phenylamino-, 3 : 31-di(phenylamino)-, 2 : 21-di(phenylamino)-, 4 : 41-di-(b -naphthylamino)-, 4 : 41-di-(p-biphenylamino)-, 3 : 31-di-(p-tolylamino)-, 4 : 41-di-(o-tolylamino)-, 4 : 41-di-(p-benzylphenylamino)-, 4 : 41-di(phenylamino)-2 : 21-dimethyl-, 3 : 31-di-(b -naphthylamino)-2 : 21-dichloro-, 4 : 41-di-(p-anisylamino)-, 4 : 41-di-(p-phenetylamino)-, 4 : 41-di-(p-biphenylamino)-3 : 31-dibromo-, 3 : 31di-(p-phenoxyphenylamino)-, 4 : 41-di-(p-allyloxyphenylamino)-, 2 : 21-di-(p-chlorophenylamino)-, 4 : 41-di-(p-phenylamino-phenylamino)-, 3 : 31-di-(m-phenylamino phenylamino)-, and 4 : 41-di-(p-dimethylamino phenylamino) - derivatives of diphenyl carbonate; 4 : 41-diphenylamino-di-a -naphthyl carbonate, 4 : 41-di-(p-tolylamino)-di-b -naphthyl carbonate and 4 : 41-di-(p-naphthylamino 2 : 21 - diphenyl - diphenyl carbonate.  In Examples: (1) 4 : 41-diphenylamino-diphenyl carbonate; (2) 4 : 41-di-(b -naphthylamino)-diphenyl carbonate and unsymmetrical products obtainable by the action of phosgene on mixtures of sodium arylaminophenolates, e.g. a mixture of sodium phenylamino cresolates are incorporated in a rubber composition comprising pale crepe rubber, zinc oxide, lithopone, whiting, sulphur and tetramethyl thiuram monosulphide.