Patent GB-1332701-A (GB)
Title: Adhesive semi-cured sealing strip for automobile windshield
IPC: C03C27/04
Filed: 1970-11-13
Abstract: 1332701 Polythiol-terminated polymer compositions THIOKOL CHEMICAL CORP 13 Nov 1970 [17 March 1970] 54251/70 Heading C3R [Also in Division El] A composition curable on exposure to moisture comprises the following ingredients in parts by weight: liquid polythiol terminated polymer(s) or polymer blend: 100; extender and/or plasticizer: 0-300; alkaline earth metal carbonates: 0-300; fibrous filler: 2-65; carbon black: 2-75; curing agent for semicuring any uncured polymer: 0-7; moistureactivatable curing agent for final curing of polymer(s): 2-20; adhesive additive: 0-20; desiccant: 1-25À5; U/V stabilizer: 0-5, the polymer if uncured being curable to the semicured product, or being already a semi-cured or blended product, having a viscosity at 25‹ C. of at least 6000 poises and a M.wt. of at least 13,000. Suitable polymers include polythiopolymercaptans of formula HS(RSS) n RSH where R is a hydrocarbon, oxa- or thiahydrocarbon radical, and n = 2-70, or -SSH terminated polysulphides, or -SH terminated polyethers, e.g. polypropylene glycol, or hydrocarbon polymers, polyurethanes or polyalkylene sulphides. The polymer is preferably the polysulphide LP31 or LP32 of the formula where n = 42 and 23 respectively and must be partially cured e.g. with an organic peroxide to a polymer of the above viscosity or it may be blended with a high M.wt. organic ST polysulphide rubber of the formula  where n = 500, R is a random mixture 98% of which has the structure -CH 2 CH 2 OCH 2 OCH 2 CH 2 - and 2% the structure which is prepared from bis(2-chloroethyl) formal and sodium polysulphide with trichloropropane as a branch inducing agent. Included with or substituted for the ST-rubber may be chlorinated rubbers, acrylic resins, polyisobutylene, reclaimed natural and synthetic rubbers, epoxy resins, chlorinated biphenyls, coumarone-indene resins and polyamides. Curing agents include inorganic and organic peroxides, chromate salts, manganates, plumbates, permanganates and molybdates. Plasticizers-extenders which may also serve as desiccating and hygroscopic accelerating agents include chlorinated hydrocarbons e.g. biphenyls, phthalates, polyalkylene glycol benzoates. Fibrous fillers include synthetic fibres, nylon, rayon, polyester, asbestos, glass fibres. Non-fibrous fillers include clays, slate flour, asbestine, Al 2 O 3 , TiO 2 , ZnS, SiO 2 , iron oxide. Adhesive additives include polyurethane resins, chlorinated terphenyls, phenolic resins, epoxy resins, organosilicon compounds, acrylic resins, polyester resins, polyamides, liquid polysulphide polymers. U.V. light stabilizers include organic silicon-containing compounds substituted with at least one alkoxy, acyloxy, vinyl or amino group, benzophenones, benzotriazoles, aryl esters and substituted acrylonitriles. Other additives include pigments, fatty acid cure inhibitors such as stearic acid, thixotropic agents such as calcium silicate and anti-oxidants such as butylated hydroxy toluene. Uses.-For making a moisture curable sealing strip for adhesively fastening and sealing a windscreen to an automobile body.