Patent GB-838547-A (GB)
Title: A reproduction process using light-sensitive polyesters
IPC: C08L67/06
Filed: 1957-03-14
Abstract: A light-sensitive polycondensation product has carbon chains predominantly linked through ester bonds and has at least one -C=C-CO-group in the molecule, the vinyl side of which is linked to an aromatic nucleus.  The polyester preferably has a molecular weight of at least 750 and may contain amide, ether and/or thioether linking groups in addition to the ester groups. On exposure to light the polyester dimerizes or polymerizes through the double bonds and becomes insoluble and the unexposed portion may then be dissolved away with a solvent (e.g. acetone) to produce a negative (see Group XX).  The polyester is made by reacting a polycarboxylic acid (or an anhydride, chloride or ester thereof), a polyhydric alcohol (or an ester thereof) and, if desired, a modifying agent, any of which may contain the desired -C=C-CO group.  When using a modifying agent, it may be present during the polycondensation of the polycarboxylic acid with the polyhydric alcohol or it may be reacted with a polyester obtained from these substances.  Specified substances containing the -C= C-CO- are cinnamic acid and its alkyl esters and acid chloride, cinnamic acid ethanolamide, p-methoxy cinnamic acid diethanolamide, 3- and 4-nitrocinnamic acids and their esters or acid chlorides, 3- and 4-aminocinnamic acids, 3- and 4-alkoxy cinnamic acids, 3,31-azocinnamic acid, 3- and 4-carboxy cinnamic acids, 3- and 4-hydroxy cinnamic acids, 1,4-phenylene di-acrylic acid and bis-glycol esters thereof, the condensation product of 1 mol. of cyanuric chloride and 3 mols. of 3-aminocinnamic acid, the condensation product of epichlorhydrin and 3-hydroxycinnamic acid ethyl ester, (N,N-bis-b -hydroxyethyl)-aminoethyl-cinnamate, ethyl-(2,4-dimethyl)-cinnamate, pentaerythritol dicinnamic ester and chalcone compounds of formula <FORM:0838547/IV (a)/1> Specified reactants not containing this group are:-polyhydric alcohols-ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, thiodiglycol, oxalkylated thiodiglycol, glycerine, trimethylol propane, pentaerythritol, sorbitol and mannitol; polycarboxylic acids-succinic, adipic, o-, m- and p-phthalic, citric, aconitic, maleic and tartaric acid; modifying agents-tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, o-, m- and p-phenylene diamine, ethanolamine, propanolamine, butanolamine, aminopropionic acid, aminobutyric acid and amino caproic acid.  The polyesters are particularly sensitive to ultraviolet light and may be made more sensitive, particularly with respect to visible light, by adding sensitizers, e.g. cyanides or dyestuffs of the triphenylmethane, benzanthrone, quinone or anthraquinone series.  Examples describe the manufacture of polyesters from (1) phthalic anhydride, adipic acid, glycerine and cinnamic acid; (2) phthalic anhydride, adipic acid, pentaerythritol and 4-nitrocinnamic acid; (3) phthalic anhydride, adipic acid, glycerine and 4-methoxy cinnamic acid; (4) phthalic acid, adipic acid and pentaerythritol dicinnamic acid ester; (5) glycol diacetate and p-carboxycinnamic acid dimethyl ester; (6) phthalic anhydride, adipic acid and p-methoxycinnamic acid diethanolamide.  All of the above polyesters are coated on a support to make a film and the film exposed, whereby the exposed portions of the polyester are rendered insoluble.  The invention of Specification 822,861 is disclaimed.