Patent GB-554121-A (GB)
Title: Improvements in synthetic resins
IPC: C08F8/28
Filed: 1941-07-08
Abstract: 554,121. Synthetic resins. BRITISH THOMSON-HOUSTON CO., Ltd. July 8, 1941, No. 8619. Convention date, July 10, 1940. Drawings to Specification. [Class 2 (iii)] Resinous products useful for moulding, laminating, coating, adhesive and insulating purposes and for making " safety glass are obtained by simultaneously partially or wholly hydrolyzing and acetalizing a copolymer of one or more vinyl organic esters and a minor proportion of one or more organic nitriles containing at least one vinyl grouping by heating the copolymer together with one or more aldehydes, ketones or compounds engendering an aldehyde or ketone, in a liquid medium with an acid catalyst, and neutralizing and isolating the product from the reaction mass. Included in the vinyl organic esters are vinyl esters of saturated and unsaturated, aliphatic and aromatic, monobasic and polybasic acids, also included are vinyl esters containing a second polymerizable group, viz., divinyl esters. Specified vinyl nitriles are acrylo-, methacrylo- and α-chloracrylo-nitriles, beta-vinyl acrylonitrile, vinyl acetonitrile, vinyl dimethyl acetonitrile, alpha-brom acrylonitrile, allyl acetonitrile, alpha-ethyl acrylonitrile, meta-vinyl benzonitrile, ortho-vinyl phenyl acetonitrile, atropic nitrile and phenyl allyl acetonitrile. The copolymer is prepared by mixing and interpolymerizing the components with or without the addition of a catalyst and the process may be carried out under the influence of heat. Benzoyl peroxide is the preferred catalyst ; other suitable catalysts are given in Specification 552,313. It is preferred to carry out this step at 60‹ to 120‹ C., and less than 50 per cent. of the nitrile is used in the mixture. The partial or complete acetalization is carried out simultaneously with the hydrolysis which may also be partial or' complete under acid conditions. Any acetalizing agent may be used and the process may involve more than one stage using more than one acetalizing agent; specified are particular saturated and unsaturated aldehydes and ketones. The product may be modified by carrying out the acetalization reaction in the presence of other reactants, e.g. methylol forming derivatives, i.e. phenols, alcohols, amides, amines and urea compounds ; detailed lists are given. Other specified additions may be made during or after the acetalization reaction, i.e. hydrolyzed wood products, other specified resinous condensation products, natural gums and resins, phthalate and phosphate esters, etc.; detailed lists are given. The product may be stabilized by incorporation at any stage of the process of specified inhibitors or stabilizing agents, i.e. phenolic bodies, amines, amides, &c. ; dyes and specified pigments, lubricants, fillers and opacifiers may also be incorporated. Examples involve the treatment of a copolymer of 80 parts of vinyl acetate and 20 parts of acrylonitrile by weight by reaction with sulphuric or hydrochloric acids and acetic acid in aqueous solution with (1) formaldehyde alone ; (2) acetone ; formaldehyde and (3) phenol; (7) ethyl p-hydroxybenzoate ; (9) p-tert. butyl alcohol or (10) acetamide ; (5) butyraldehyde alone or together with (8) p-chlor-m-cresol or (11) urea ; and (6) chlor-acetone.