Patent GB-614389-A (GB)
Title: Improvements in or relating to the preparation of polysulphide polymers
IPC: C08G75/16
Filed: 1944-07-27
Abstract: A polysulphide polymer which after curing has resistance to cold flow is prepared by reacting a mixture containing (a) an organic compound with at least three halogen atoms or mercapto groups and (b) an organic compound with only one halogen atom or mercapto group, but also containing in a terminal position or a position adjacent thereto a reaction group adapted to promote curing of but taking no part in formation of the polymer, e.g. a vinyl aldehyde, carboxyl or cyano group, with an alkaline p  polysulphide, where organic compounds containing halogen are employed or with an oxidizing agent where they contain mercapto groups.  The molar ratio of compound (a) to compound (b) is between 1 to 2 and 100 to 1.  Part of organic compound (a) may be replaced by an organic compound having two halogen atoms or mercapto groups.  The polymer first produced consists of a number of cross-linked short chains and is readily workable.  It may be cured by action upon the group in or adjacent to the terminal position in compound (b).  When this is a vinyl group, curing may be effected by heating preferably with sulphur.  Where it is a hydroxyl group, curing is by reaction with polybasic acids or aldehydes.  Where it is a carboxyl group or where carboxyl groups are produced by hydrolysis of the cyano groups, curing may be effected by reaction with diamines or polyhydric alcohols. Suitable compounds containing three functional groups are 1,2,3-trichloropropane and 1,2,3-trimercaptopropane.  Some suitable compounds with one functional group are XCH2-CH3=CH2; XCH2CH=CHCH3; XCH2CH2CH2OH; CH3CHXCH2OH; XCH2CH2OH; X(CH2)5\t COOH; X(CH2)5CHO; XCH2CH2C­N, where X denotes a halogen atom or mercapto group.  Also mentioned are 4-chlorobutene-1; 3-chlorobutene-1; 5-chloropentene-1; 4-chloropenten-2; <FORM:0614389/IV(a)/1> Where a polysulphide other than a disulphide is employed, excess sulphur may be stripped from the product, as set forth in U.S.A. Specification 2,278,128.  In example (1), allyl chloride and 1,2,3-trichloropropane are reacted with excess sodium tetrasulphide containing freshly precipitated magnesium hydroxide.  The latex obtained is stripped with caustic soda, washed and the granular dispersion separated and dried.  In example (2), the reaction mixture also contains a proportion of dichlorodiethyl formal.  The products of both examples are thermoplastics and may be worked on hot mixing rolls.  They may be vulcanized with zinc oxide or sulphur.  Examples (3), (4) are similar to (1), (2), but use sodium disulphide.  Example (3) employs more allyl chloride than example (1), and example (6) less than in example (2).  Example (7) is similar to example (2), but uses 4-chloro-butene-1 instead of allyl chloride.  The intermediate polymer may be employed as a latex, coagulum or as separated, dried granules.  They may be compounded with ingredients such as zinc oxide, sulphur, carbon black and tetramethyl or tetrabutyl thiuram disulphide, moulded or applied as a coating and cured.  The polymers may be cured together with butadiene type polymers or natural rubber. In example (10), ethylene monochlorhydrin is used instead of the allyl chloride of example (1), the polymer is mixed with zinc chloride, carbon black and trioxane and cured in a mould at 310 DEG F.  In example (11), 3-chloro-propanal-1 replaces the allyl chloride and the product cured by heating with zinc chloride, carbon black and ethylene glycol.  In example (12), 5-chloro-n-capronic acid replaces the allyl chloride and the product is cured with zinc chloride, carbon black and glycerol.  In example (13), b -chloroethyl cyanide replaces the allyl chloride, the cyano groups are hydrolysed to carboxy groups and the product is cured as in example (12). U.S.A. Specifications 1,854,423, 1,890,191, Re-issue 19,487, 2,142,144, 2,142,145, 2,195,380, 2,206,641, 2,206,643, 2,261,044, 2,221,650, 2,235,621, 2,278,127 and 2,282,287 are referred to.