Patent GB-861835-A (GB)
Title: Improvements in co-polyester-baseo adhesive compositions
IPC: C08G63/91
Filed: 1959-02-19
Abstract: An adhesive composition for use in splicing photographic films (see Group XX) comprises a copolyester which is the esterification product of (1) hexahydroterephthalic acid in an amount of 10-90 mol. per cent of the copolyester; (2) a saturated aliphatic dicarboxylic acid represented by the formula HOOC(CH2)nCOOH, where n is 4-8, in an amount of 5-45 mol. per cent of the copolyester; (3) terephthalic or isophthalic acid in an amount of 5 to 45 mol. per cent of the copolyester; and (4) a glycol having 2 to 10 carbon atoms and 0 to 4 oxygen atoms in addition to those in the hydroxyl groups.  The copolyester may be made by reacting dialkyl esters of the acids with the glycol in the presence of an esterification catalyst (e.g. a mixture of antimony oxide, calcium acetate and, possibly, zinc borate).  Cross-linking agents (e.g. glycerol, pentaerythritol, a diisocyanate or a peroxide) may be added during or after the manufacture of the copolyester.  The adhesive composition may also contain (a) other polymers, e.g. a thermoplastic phenol/formaldehyde resin (derived, e.g., from p-phenylphenol or butylphenol), a heat-hardenable phenol/formaldehyde resin, a coumarone/indene resin (alone or in admixture with an epoxide resin), an arylsulphonamide/formaldehyde resin, polystyrene, ethyl cellulose or cellulose acetate; (b) a filler, e.g. silica (preferably of particle diameter 10-20 millimicrons), an estersil, magnesium oxide, magnesium silicate, calcium silicate, zinc oxide, litharge, barium sulphate, clay, chalk, mica, carbon black or protein meal; or (c) a plasticizer, e.g. dibutyl phthalate, dioctyl phthalate, diethyl phthalate, dioctyl sebacate, dioctyl azelate, methyl pentachlorostearate, tricresyl phosphate, trioctyl phosphate, triphenyl phosphate or tributoxy-ethyl phosphate.  The adhesive composition may be in the form of (A) a viscous thermoplastic mass; (B) a solution in a solvent (e.g. tetrahydrofuran, diethyl ether, dioxan, methyl acetate, methyl formate, ethyl acetate, ethyl formate, acetone, cyclohexanone, methyl ethyl ketone, methylene chloride, chloroform, trichlorotrifluoroethane, nitromethane or nitroethane); (C) a mono-filament or multi-filament structure; or (D) an adhesive layer.  In examples in which the copolyester is made by reacting a mixture of dimethyl hexahydroterephthalate, dimethyl sebacate, dimethyl terephthalate, and ethylene glycol, adhesives comprise (1)-(4) the copolyester, or a mixture thereof with a p-phenyl phenol/formaldehyde resin, in the form of a filament; (5) a polyethylene terephthalate film coated with a solution of the copolyester in methylene chloride together with bis - (p - isocyanatophenyl) - methane and tri-n-butylamine, followed by evaporation of the solvent; (6), (7), (8), (10), (12), (13) and (14) a solution of the copolyester in methylene chloride together with one of the following polymers, viz. a p-phenyl phenol/formaldehyde resin, a coumarone/indene resin (together, if desired, with magnesium oxide or finely-divided silica), a hard arylsulphonamide/formaldehyde resin, a liquid arylsulphonamide/formaldehyde resin (in butyl acetate), a mixture of a coumarone/indene resin and an epoxide resin (together with ethanolamine), polystyrene, ethyl cellulose, a commercial heat-hardenable phenol-formaldehyde resin or a mixture thereof with ethyl cellulose or cellulose acetate, or a mixture of a coumarone/indene resin and a p-phenyl phenol/formaldehyde resin; (9) a mixture of the copolyester, a coumarone/indene resin, finely-divided silica, methylene chloride, o-phenyl phenol and toluene diisocyanate; (15) and (16) a film made by casting a solution of the copolyester and a p-phenyl phenol/formaldehyde resin in methylene chloride, the solution containing also finely-divided silica or a mixture thereof with an estersil.  In a further example: (11) a copolyester made by heating a mixture of dimethyl hexahydroterephthalate, dimethyl sebacate, dimethyl terephthalate and pentaerythritol was made into an adhesive by dissolving it in acetone and adding a commercial heat-hardening phenol/formaldehyde resin. Specification 578,079 is referred to.