Acyl-(2'-hydroxybiphenyl-2-yl)-phosphinic acid salts, their preparation and use

Abstract

The invention relates to acyl-(2'-hydroxydiphenyl-2-yl)-phosphinic acid salts of formula (I) ##STR1## in which each of the radicals R.sup.1, R.sup.2 and R.sup.3 may be included singly or multiply and in which R.sup.1 and R.sup.2 are mutually independently hydrogen, an alkyl or alkoxy radical with 1 to 6 carbon atoms or halogen with an atomic number of 9 to 35; R.sup.3 means the same as R.sup.1 or R.sup.2 ; Ar is an aromatic hydrocarbon radical with 6 to 10 carbon atoms; and Me is a cation of at least one alkaline metal or N(R.sup.4).sub.4 + in which the radicals R.sup.4 are the same or different and stand for an alkyl radical with 1 to 6 carbon atoms. The invention also relates to a process for producing these compounds (I) and their use as photoinitiators in photopolymerisable materials, preferably on an aqueous basis.

Dependencies are inferred from the claim text.