GB808629A - Photographic material - Google Patents

Abstract

A polycarbonate resin contains securing units of the formula <FORM:0808629/IV (a)/1> wherein each R1 (which may be the same or different) represents an hydrogen atom, an alkyl group of up to 5 carbon atoms or a cycloalkyl or aryl group, n is an integer greater than 20 and X is the group <FORM:0808629/IV (a)/2> or a cycloalkyl group (including decahydronaphthalene), where R1 and R2 are hydrogen atoms, alkyl groups of up to 10 carbon atoms, cycloalkyl groups, aralkyl or alkaryl groups with up to 4 carbon atoms in the side chain, or phenyl or furyl groups. The polycarbonates are derived from one or more di-(monohydroxaryl)-alkanes (many examples are given), and these may be mixed with other dihydroxy compounds such as ethylene or polyethylene glycols, specified alkane diols, xylylene glycols, cyclohexane diols, 2:2 - (4:41 - dihydroxy - dicyclohexyl)-propane, 2:6-dihydroxydecahydronaphthalene, hydroquinone, resorcinol, pyrocatechol, dihydroxydiphenyls, dihydroxynaphthalenes, dihydroxyanthracene, 2:21 - dihydroxydinaphthyl or the hydroxybenzyl alcohols. The ends of the polycarbonate chains may be terminated by the residues of phenols such as t-butylphenol, cyclohexyl-phenol or 2:2-(4-hydroxyphenyl - 41 - methoxyphenyl) - propane or by amines such as aniline or methylaniline. In Example 2, a polycarbonate film is treated on one side with a solution comprising a mixed acetal of polyvinyl alcohol, benzaldehyde and the sodium salt of benzaldehyde-2; 4-disulphonic acid, a partially saponified vinyl chloride/vinyl acetate copolymer, methanol, dimethyl formamide and methylene chloride. In Example 7, a polycarbonate film is treated on one side with a solution comprising a partially saponified vinyl chloride/vinyl acetate copolymer, gelatine, ethylene chlorohydrin, phthalic anhydride, acetone, glyoxal, methylene chloride, methanol and tetrachloroethane. Specifications 772,627, 808,485 and German Specification 958,715 is referred to.