Patent GB-903649-A (GB)
Title: Improvements relating to photopolymerisable compositions and articles containing them
IPC: C08F251/02
Filed: 1961-01-05
Abstract: A photopolymerizable composition comprises (a) an addition-polymerizable ethylenically unsaturated compound compatible with the other constituents and having a boiling point above 100 DEG C. at normal pressure and a molecular weight less than 1,500, containing 1-4 terminal ethylenic groups, capable of forming a high polymer by photo initiated addition polymerization in the presence of an addition polymerization initiator therefor activatable by actinic light, (b) an addition polymerization initiator compatible with the other ingredients and activatable by actinic light and not active thermally below 85 DEG C., (c) a mixture of polyethylene oxides having an average molecular weight from about 100,000 to about 2,000,000 and (d) at least one essentially linear cellulose ester; said constituents being present in the respective proportions (a) 10-60, (b) 0,0001-6,0, (c) 2-25 and (d) 40-90, parts by weight. Constituent (a) may be an acrylic acid diester of a diol of formula HO(CH2CH2O)nH where n is 1 to 30.  Acrylic acid diesters of mixtures of polyethylene glycols of average molecular weight between 200 and 600 can be used.  Specified compounds include triethylene glycol diacrylate, the polyethylene glycol diacrylates referred to above, acrylic and methacrylic acid esters of diethylene glycol, triethylene glycol and higher polyalkylene glycols generally, e.g. methoxytriethylene glycol acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate and dimethacrylate, diethylene glycol diacrylate, methoxytriethylene glycol methacrylate, and the acrylates, diacrylates, methacrylates and dimethacrylates of tetraethylene glycol, dipropylene glycol, and polybutylene glycols, diacrylates and dimethacrylates of etherglycols which also contain a combined intrachain dibasic acid unit, e.g. the diacrylate and dimethacrylate of glycols of structure <FORM:0903649/IV(a)/1> where R is a divalent hydrocarbon radical, e.g. methylene or ethylene, glycerol triacrylate, 1,2,4-butanetriol trimethyacrylate and pentaerythritol tetramethacrylate, and vinyl and vinylidene monomers, especially the vinyl monomers referred to in Specifications 741,294 and 741,441.  Constituent (b), the addition polymerization initiator, is preferably employed in amount 0,001 to 0,2 parts by weight.  Specified initiators are vicinal ketaldonyl compounds, e.g. diacetyl, benzil, a -ketaldonyl alcohols, e.g. benzoin, pivaloin, acyloin ethers, e.g. benzoin methyl and ethyl ethers, a -hydrocarbon-substituted aromatic acyloins including a -methyl-benzoin, a -allylbenzoin and a -phenylbenzoin, and benzoyl and similar peroxides.  Preferred photo-initiators which are thermally inactive at temperatures below 185 DEG C. include anthraquinone, 1-chloro- and 2-chloro-anthraquinone, 2-methyl-, 2-tert-butyl- and octamethyl-anthraquinone, 1,4-naphthoquinone, 9,10-phenanthrene-quinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1,4-dimethyl and p 2,3-dimethyl-anthraquinone, 2-phenylanthraquinone, 2,3-diphenyl-anthraquinone, sodium anthraquinone-a -sulphonate, 3-chloro-2 methyl anthraquinone, retenequinone, 7,8,9,10-tetrahydronaphthacene-quinone, and 1,2,3,4 - tetrahydrobenz[a ]anthracene-7,12-dione.  Specified polyethylene oxide mixtures, constituent (c) have average molecular weights of 100,000, 500,000, and 2,000,000.  Constituent (d), the cellulose ester, may be the cellulose partial ester of a saturated monocarboxylic acid having 2 to 4 carbon atoms, e.g. cellulose acetate, cellulose acetate-propionate, cellulose acetate-butyrate, and derivatives thereof, e.g. cellulose acetate succinate, cellulose acetate glutarate, and cellulose acetate phthalate.  A thermal addition polymerization inhibitor may also be present, preferably in an amount of 0,001 to 6 parts by weight.  Those specified include p-methoxyphenol, hydroquinone, alkyl and aryl-substituted hydroquinones, tert-butyl catechol, pyrogallol, copper resinate, naphthylamines, b -naphthol, cuprous chloride, 2,6-ditert-butyl-p-cresol, phenothiazine, pyridine, nitrobenzene, dinitrobenzene, p-toluquinone, chloranil, and thiazine dyes, e.g. Thionine Blue G, Methylene Blue B and Toluidine Blue O.  In an example, diethylcyclo-hexylamine is also present as an esterification catalyst.  Inert organic or inorganic fillers, as described in Specifications 741,294 and 741,441 may also be present.  In the examples, the compositions are mixed by milling in the presence of water.  For the application of the compositions to photographic processes, see Group XX. Specifications 741,470, 786,119, 802,853, 807,948 and 864,041 also are referred to.