Patent GB-742975-A (GB)
Title: Hydrocarbontin derivatives of tris-mercapto borate esters
Inventor: RAMSDEN HUGH EDWIN
IPC: C08K5/58
Filed: 1953-11-26
Abstract: Polyvinyl chloride compositions containing a plasticizer such as 2-ethyl hexyl phthalate are stabilized against heat deterioration by addition of a hydrocarbontin derivative of a trismercapto borate ester, such as compounds of formula (R2Sn)3[B(OR1S)3]2 wherein R is alkyl, alkenyl, aryl or aralkyl, R1 is an alkylene or arylene radical and wherein each tin atom is bonded to two sulphur atoms.  Mono-and tri-hydrocarbon tin derivatives are included in the scope of the invention.  Specified stabilizers include tri(dibutyltin) - di(S,S1,S11 tris - mercaptoethyl borate), tri(diphenyltin) - di(S,S1,S11 tris - mercaptoethyl borate), tri(dimethyl tin) - di(S,S1, S11 tris - mercaptophenyl borate), tri(diphenyl-ethyltin) - di(S,S1,S11 - tris - b  - phenyl - b  - mercaptoethyl borate) and tri(dilauryltin)-di-(S,S1, S11-tris-o-mercaptoethyl phenyl borate).ALSO:The invention comprises hydrocarbon tin derivatives of trismercapto-borate esters, such as compounds of formula (R2Sn)3[B(OR1S)3]2 wherein R is alkyl, alkenyl, aryl or aralkyl and R1 is an alkylene or arylene radical and wherein each tin atom is bonded to two sulphur atoms.  Mono-and tri-hydrocarbon tin derivatives are included in the scope of the invention.  R may be methyl, ethyl, propyl, butyl, hexyl, lauryl, allyl, methallyl, phenyl, tolyl, benzyl or phenylethyl.  R1 may be derived from a mercaptoalkanol or mercaptophenol such as o- and p-mercaptophenol, o-mercaptobenzyl alcohol, p-hydroxybenzyl mercaptan, b -phenyl-b -mercaptoethanol, 2-mercaptopropanol-1, 3-mercaptopropanol - 1, 1 - mercaptopropanol - 2,2 - mercaptobutanol - 1 and 5 - mercapto - n - pentanol.  The compounds of the invention may be prepared by reacting a hydrocarbon tin compound with a tris-mercapto alkyl or aryl borate, in the presence of toluene or benzene.  To obtain products of the above formula a hydrocarbon tin oxide may be used.  The mercaptoborate esters may be prepared by reacting boric acid with the mercapto alcohol.  The hydrocarbon tin derivatives may be used for stabilizing polyvinyl chloride compositions against heat deterioration (see Group IV (a)) as rubber accelerators and rubber antioxidants (see Group V) as oil additives and polymerization accelerators.  In an example tris-mercaptoethyl borate is prepared by reacting boric acid and mercaptoethanol in the presence of toluene. The product is reacted with dibutyl tin oxide in the presence of toluene to give tri(dibutyl tin)-di-(S,S1,S11 tris - mercapto - ethyl borate).  Other examples describe the preparation of tri(diphenyltin) - di - (S,S1,S11 tris - mercaptoethyl borate), tri(dimethyl tin) - di - (S,S1S11 tris - mercaptophenyl borate), tri(diphenylethyl tin) - di - (S,S1,S11 tris - b  - phenyl - b -mercaptoethyl borate) and tri(dilauryl tin)-di-(S,S1,S11 - tris - o - mercaptoethylphenyl borate).ALSO:Hydrocarbontin derivatives of tris-mercapto borate ester (see Group IV(b)) are used as rubber antioxidants and vulcanization accelerators.  Mono-, di-, and tri-hydrocarbon derivatives are included in the scope of the invention; the di-hydrocarbon derivatives have the general formula (R2Sn)3[B(OR1S)3]2 wherein R is alkyl, alkenyl, aryl or aralkyl, R1 is an alkylene or arylene radical and wherein each tin atom is bound to two sulphur atoms.  Specified compounds include tri (dibutyltin) - di (S, S1, S11 tris-mercaptoethyl borate), tri (diphenyltin) - di (S, S1, S11 tris-mercaptoethyl borate), tri (dimethyltin) - di (S, S1, S11 tris-mercaptophenyl borate), tri (diphenylethyltin) - di( S, S1, S11 tris-b -phenyl-b -mercaptoethyl borate) and tri (dilauryltin) - di (S, S1, S11-tris-o-mercaptoethylphenyl borate).