Patent GB-568565-A (GB)
Title: Manufacture of vinyl compounds, synthetic resins and other products derived therefrom
IPC: C08F28/00
Filed: 1940-05-08
Abstract: Esters of vinyl thiol are prepared by pyrolysis of compounds having the formula XCH2CH2 SCOR wherein X is a residue of a carboxylic or thiocarboxylic acid and SCOR the residue of a thiocarboxylic acid. Resinous materials are obtained by polymerising the products either alone or in admixture with polymerisable ethenoid compounds, and the polymers may be hydrolised.  Both the polymers and their hydrolysed products may be subjected to oxidation.  In examples: (1) 2-acetoxyethylthioacetate is heated in the presence of carbon dioxide to give vinylthioacetate; 2-acetylthioethylthioacetate gives the same product; (2) vinylthioacetate is polymerised using benzoylperoxide and ether-borontrifluoride as catalyst; (3) vinylthioacetate is polymerised at ordinary temperature, with exclusion of air by allowing it to stand for 5 days; polymerisation is also effected by heating and by exposure to ultraviolet light; (4) vinylthioacetate is interpolymerised with vinyl acetate, methylmethacrylate and styrene; (5) polyvinylthioacetate is hydrolised by means of caustic soda, the polyvinylthiol is precipitated by means of acetic acid and dried; (6) an alkali solution of polyvinythiol is oxidised to the disulphide by bubbling in oxygen; (7) polyvinyldisulphide is oxidised with nitric acid to form a product containing sulphonic acid groups; (8) polyvinylsulphonic acid is prepared directly from polyvinyl thioacetate by means of nitric acid.  Interpolymers may similarly be subjected to hydrolysis and oxidation.  The following acids may be used for the preparation of starting materials; propionic, butyric, valeric, chloracetic and lactic acids, the esters being prepared by treating the acids, their halides or anhydrides with 2-mercaptoethanol.  Catalysts for the polymerisation are: hydrogen peroxide, urea, peroxide, lauryl peroxide, succinic peroxide, metal halides, sulphur dioxide and borontrifluoride.  Hydroquinone, naphthoquinone, anthaquinone and copper sulphate stabilise the monomeric vinylthio esters. Specified ethenoid compounds which may be used for interpolymerisation are: ethyl, propyl, octyl and dodecyl esters of acrylic and methacrylic acids, chlor-2-butadiene-1 : 3, butadiene-1 : 3, vinylsuccinimide and vinyl phthalimide. Polyvinyl thioacetate and its interpolymers are useful in the coating, moulding, impregnating and adhesive industries. p  Interpolymers of vinyl thioacetate and methacrylic acid are tanning agents.  Polyvinyl sulphonic acid is a tanning agent for hides, gelatin and protein films.  The properties of the products may be modified by the addition of plasticisers, resins, cellulose esters and ethers, pigments, fillers and dyes.  The production of polyvinyl mercaptols, mercaptans, sulphonic acid and sulphonylchloride is mentioned. 2-Acetoxyethylthiolacetate is prepared by heating ethylenesulphide and acetic anhydride in pyridine.  2-Acetylthioethylthiolacetate is prepared by heating diacetylsulphide with ethylenesulphide in pyridine.  The Provisional Specification includes the preparation of vinylthiolester by reacting thiolacetic acid with acetylene, by dehydrohalogenation of 2-chlorethylacetate and by the pyrolysis of any 2-mercaptoethanol di-carboxylic ester; esters derived from benzoic, toluic, naphthoic, fusoic and quinolinic acid being mentioned.