Patent GB-807948-A (GB)
Title: Photopolymerisable compositions and elements containing the same
IPC: C08F2/46
Filed: 1957-07-08
Abstract: A photopolymerizable composition comprises (1) 10-60 per cent by weight of an addition-polymerizable ethylenically unsaturated compound of molecular weight less than 1500 having a boiling point over 100 DEG  C. at normal pressure; (2) 40-90 per cent by weight of a cellulose derivative having lateral free oxyacid groups or alkali metal, ammonium or substituted ammonium oxyacid salt groups and having a total degree of substitution of 2.0-3.0 which is soluble to the extent of at least 10 per cent by weight in 1 per cent aqueous ammonia; and (3) an addition polymerization initiator activatable by actinic light, the proportions of (1) and (2) being based on the total composition exclusive of (3). The composition may also contain 5-20 per cent by weight of an inert filler material which is substantially transparent to actinic light, e.g. an organophilic silica, bentonite or glass, and there may also be present a polymerization inhibitor to prevent spontaneous polymerization, e.g. hydroquinone or tert.-butyl catechol, other addition polymers and cellulose derivatives, and a plasticizer, e.g. triacetin acetin or triethylene glycol dipropionate or diisobutyrate.  Specified components (1) include the ethylene glycol, diethylene glycol, glycerol and pentaerythritol diesters of acrylic acid, the ethylene glycol, 1:3 propylene glycol, 1:4 benzene-diol and 1:5 pentanediol diesters of methacrylic acid, methylene and ethylene bis acrylamides and methacrylamides, 1:6-hexamethylene bis-acrylamide, diethylene triamine thiomethacrylamide, bis (g -methacrylamidopropoxy) ethane, b -methacrylamidoethyl methacrylate, N - (b  - hydroxyethyl) - b  - (methacrylamido) ethyl acrylate, N:N-bis (b -methacryl oxyethyl) acrylamide, divinyl esters of succinic, adipic, phthalic, terephthalic, 1:3 benzene disulphonic and butane 1:4 disulphonic acids, and sorbaldehyde.  Specified components (2) include cellulose propionate/hydrogen sebacate, cellulose acetate/methacrylate/hydrogen succinate, cellulose acetate/crotonate/hydrogen phthalate, cellulose benzoate/hydrogen terephthalate, cellulose cyclohexanecarboxylate/hydrogen oxalate, cellulose nitrate/hydrogen phthalate, methyl cellulose/hydrogen phthalate, ethyl cellulose/hydrogen succinate, cyclohexyl cellulose/hydrogen succinate, cyanoethyl cellulose/hydrogen phthalate, allyl cellulose/hydrogen succinate, benzyl cellulose hydrogen phthalate, O - ethyl cellulose acetate/hydrogen succinate, O-cyanoethyl cellulose stearate/hydrogen phthalate, O - benzyl cellulose acetate/propionate/hydrogen succinate, O-hydroxyethyl cellulose acetate/hydrogen succinate, O-carboxymethyl cellulose acetate/hydrogen succinate, cellulose butyrate/hydrogen/succinate/hydrogen phthalate, ethyl cellulose/hydrogen succinate/hydrogen maleate, O-ethyl cellulose acetate/hydrogen succinate/hydrogen phthalate, cellulose acetate/hydrogen sulphate/hydrogen phthalate, cellulose hydrogen o-sulphobenzoate, cellulose acetate/hydrogen-p-toluenesulphonate and cellulose acetate/hydrogen thiodigylcollate.  A description is given of the preparation of cellulose acetate/butyrate/hydrogen succinate by hydrolysing commercial cellulose acetate/butyrate with dilute ammonia in aqueous dioxane, pouring the reaction mixture in excess water with stirring, filtering off the precipitate, washing and drying; the resultant product containing an increased number of free hydroxyl groups is reacted with succinic anhydride in pyridine solution, the reaction is terminated by pouring into water and the precipitate is filtered off, washed and dried.  Preferably component (3) is used in amounts of from 0.01-5.0 per cent based on the weight of component (1), is substantially inactivatable below 85 DEG  C. and emits free radicals, specified examples being diacetyl, benzil, pivaloin, benzoin methyl and ethyl ethers, a -methyl benzoin, a -allyl benzoin and a -phenyl benzoin.  Specifications 410,118, [Group IV], 741,441, 741,470, [both in Group XX], and 792,840 are referred to.