Carbodiimides and/or oligomeric polycarbodiimides based on 1,3-bis (1-methyl-1-isocyanatoethyl)benzene, their preparation, and their use as hydrolysis stabilizers

Claim 1

A process for the preparation of a carbodiimide or oligomeric polycarbodiimide of the formula; ##STR4## where the R radicals are identical or different and are selected from the group consisting of --NCONHR 1 , --NHCONR 1 R 2 --, and --NHCOOR 3 --, where R 1 and R 2 may be identical or different and are alkyl, cycloalkyl, or aralkyl, and R 3 is identical to R 1 or is alkoxypolyoxyalkylene, and n is an integer from 0 to 10, which comprises a) condensing 1,3-bis(1-methylisocyanatoethyl)benzene in the presence of catalysts with elimination of carbon dioxide, subsequently reacting all or some of the free terminal isocyanate groups of the resultant (poly)carbodiimide with at least one aliphatic, cycloaliphatic or araliphatic amine, alcohol and/or alkoxypolyoxyalkylene alcohol, and then removing or deactivating the catalysts, or b) reacting up to 50% of the isocyanate groups of 1,3-bis(1-methyl-1-isocyanatoethyl)benzene with at least one aliphatic, cycloaliphatic or araliphatic amine, alcohol and/or alkoxypolyoxyalkylene alcohol, subsequently condensing all or some of the free isocyanate groups in the presence of catalyst with elimination of carbon dioxide, and then removing or deactivating the catalysts.