Patent GB-846908-A (GB)
Title: Light-sensitive polyesters and photographic reproduction processes employing them
IPC: C08G63/54
Filed: 1956-11-26
Abstract: A light-sensitive polyester is made by polyesterifying a dihydric compound of formula HO-R-OH, where R is a bifunctional group containing 2-12 carbon atoms and a substituted malonic acid of formula:  <FORM:0846908/IV(a)/1> where R1 is a radical free of constituents which are functional in the polyesterification reaction and R11 is a hydrogen atom or a lower alkyl group, or R11 and R1 together represent the atoms necessary to complete a nucleus, having another double bond conjugated with that between CR11 and R1. Instead of using the free acids, their ester-forming derivatives may be used, e.g. the di- or mono-esters, the dichlorides, the monochlorides-monoesters or the ammonium or amine salts.  Specified dihydric compounds are ethylene-, diethylene-, triethylene-, 1:3-propylene-, 1:2-propylene-, 1:4-butylene-, 2:3-butylene-, 1:5-pentylene-, 2:2-dimethyl-1:3-propylene-, decamethylene- and dodecame-thylene-glycols; also p-dihydroxymethylbenzene and hydroquinone.  Specified dicarboxylic acids are cinnamylidene-, crotonylidene-, gamma-methylcrotonylidene-, o-nitrocinnamylidene-, naphthylallylidene-, 2-furfucylidene-, N-methyl-pyridylidene-2-ethylidene-, N-methylquinolidene-2-ethylidene-, N-methylbenzothiazolylidene-, p-dimethylaminocinnamylidene-, alpha-furylally-lidene- and sulphonated 2-pentenylidene malonic acids.  Catalysts for the polyesterification reaction are sulphuric and p-toluene sulphonic acids (when using free acids) and butyl titanate or antimony oxide (when using esters of the acids).  Those polyesters containing nitrogen may be quarternized by heating with a dialkyl sulphate, an alkyl sulphonate, methyl iodide, benzyl iodide or allyl iodide but the quarternized polyesters revert to their unquarternized form when heated to about 100 DEG C.  The polyesters are soluable in organic solvents (e.g. acetone, 2-methoxylethyl acetate, methylglycol acetate, 2-methoxy-ethanol, aldehydes, aromatic solvents, methylene chloride or trichloroethylene) and those containing sulphonate or quartenary ammonium groups are soluble in water.  On exposure to light, however, they become insoluble and may then be used for photographic purposes (see Group XX).  When thus used, they may be applied to a backing dissolved in a solvent together if desired with a sensitizer (many specified) or a lacquer resin (e.g. polymethyl methacrylate or an alkyd resin). The polyester may also be used as a dielectric or as a support for pigments or dyes.  Specifications 713,947, 717,708, 717,710, 717,711, 717,712 and 743,455 are referred to.ALSO:The Specification contains examples describing the preparation of certain 2-propenylidene malonic compounds as follows:- (2) Ethyl cinnamylidene malonate is made by refluxing a mixture of ethyl malonate, cinnamaldehyde and acetic anhydride ; (6) Ethyl crotonylidene malonate is made by refluxing a mixture of ethyl malonate, crotonaldehyde, methylene chloride and piperidine ; (7)-(10) Ethyl gamma-methylcrotonylidene malonate, ethyl o-nitrocinnamylidene malonate, ethyl naphthylalkylidene malonate and ethyl alpha-furylallylidene malonate are similarly prepared but using tiglic aldehyde, o-nitrocinnamaldehyde, alpha-naphthylacrolein or alpha-furanacrolein respectively instead of crotonaldehyde ; (11) Ethyl N-methylpyridylidene-2-ethylidenemalonate is made by first reacting methyl sulphate with alpha-picolene, then adding ethyl ethoxymethylenemalonate and alcoholic caustic soda solution and further reacting ; (12) Ethyl N-methylquinolylidene-2-ethylidene malonate is made by first reacting quinaldine with methyl p-toluenesulphonate and then heating the product with ethyl ethoxymethylene malonate and pyridine ; (13) Ethyl-N-methylbenzothiazolylidene- 2-ethylidene malonate is made by refluxing a mixture of 2-methylbenzothiazole methyl iodide, ethyl ethoxymethylene malonate and pyridine ; (17) Ethyl p-dimethylaminocinnamylidene malonate is made by refluxing a mixture of p-dimethylaminocinnamaldehyde, ethyl malonate, benzene and piperidine.  a N-aphthaldehyde is obtained by reacting a -chloromethyl naphthalene with aqueous KI and hexa methylene tetramine in acetic acid under reflux ; p-dimethylamino cinnamaldehyde is obtained, by reacting the corresponding benzaldehyde with paraldehyde at below 0 DEG C. and then neutralising with aqueous sodium carbonate.  Specifications 713,947, 717,708, 717,710, 717,711, 717,712, and 743,455 are referred to.