Patent GB-954110-A (GB)
Title: Terephthalate copolyester adhesive compositions
IPC: D06Q1/04
Filed: 1962-02-27
Abstract: An adhesive composition, suitable for the manufacture of polyester/metal laminates (see Division B5) comprises a solution in an organic solvent of (A) a linear copolyester of at least one diol and a mixture of dicarboxylic acids including 25 to 85 mol % of terephthalic acid, (B) a diepoxide having at least two cycloaliphatic rings per molecule, two of said rings each having an oxirane oxygen atom joining adjacent carbon atoms of the ring, and one or both of (C) an adduct of pyromellitic dianhydride and a polyol having two hydroxyl subsitituents therof condensened with two mole of the dianhydride, and (D) an adduct obtained from an organic diisocyanate and one or more triols or a mixture thereof with one of more diols, the molar proportion of diisocyanate being sufficient to provide more than one and up to two isocyanate group per hydroxyl substituent. The preferred proportions are (A) 100 parts, (B) 2-70 parts, (C) up to 10 parts, (D) up to 25 parts.  In the copolyester A, the diol component may include a polymethylene glycol of formula HO (CH2)n OH, where n=2.10 or an alkyl substituted derivative thereof (e.g. neopentylene glycol), propylene glycol, 1: 2- or 1: 3-butylene glycol, a di- or higher polyethylene glycol, dipropylene glycol, polytetramethylene glycol or cyclohexanediol-1: 4; the dicarboxylic acid used in addition to the terephthalic acid may be a straight chain aliphatic saturated bicarboxylic acid which may contain oxygen atoms in the chain or may be alkyl substituted, or it may be cyclohexane-1:4-dicarboxylic acid or an aromatic dicarboxylic acid such as orthophthalic, isopahthalic bibenzoic, tetramethylene bis-p-oxybenzoic, ethylene-bis-poxybenzoic or 2: 6-naphthalic acid. The diepoxide (B) is preferably one having the formula: <FORM:0954110/C3/1> wherein X is a divalent radical of formula: <FORM:0954110/C3/2> or <FORM:0954110/C3/3> <FORM:0954110/C3/4> wherein-R-is an aliphatic or aromatic divalent hydrocarbon group, -R1-is a lower aliphatic hydrocarbon or oxyalkylene group and R1-R6 are hydrogen atoms or lower alkyl groups. The adduct (c) has the formula: <FORM:0954110/C3/5> where Y is an aliphatic, cycloaliphatic or aromatic residue of a polyol.  The organic solvent may be 1: 1: 2-trichloroethane, chloroform, methylene chloride, tetrachloroethane dioxane or tetrahydrofurane or a mixture thereof with cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol, toluol, xylol or benzol.  The adhesive composition may also contain (E) a plasticizer e.g. dibutyl phthalate, di-a -ethylhexylphthalate, tricresyl phosphate, butyl-phthalyl butyl glycolate, a polyethylene glycol a polypropylene glycol or a polytetramethylene glycol or (F) a pigment or dye.  Examples are given in which the copolyester (A) is derived from (a) ethylene glycol, terephthalic acid (40%), imphthalic acid (40%), adipic acid (10%) and sebacic acid (10%), (b) ethylene glycol, terephthalic acid (55%) and sebacic acid (45%), (c) ethylene glycol, terephthalic acid (33%), imphthalic acid (17%) and sebacic acid (50%), (d) ethylene glycol, terephthalic acid (55%) and "isosebacic acid", i.e. a mixture of 2-ethyl-suberic,2:5-diethyladipic and sebacic acids (45%), (e) ethylene glycol (99%), polyethylene glycol 1000 (1%), terephthalic acid (55%), isophthalic acid (25%) and "isosebacic acid" (20%), (f) ethylene glycol (99%), polytetramethylene glycol 1000 (1%), terephthalic acid (55%), imphthalic acid (25%) and "isosebacic acid" (20%), (g) ethylene glycol (85%), polyethylene glycol 400 (15%), terephthalic acid (83%), imphthalic acid (17%).  Also in the examples, the diepoxide (B) used is 3, 4-epoxy, 6-methyl-cyclohexylmethyl 3, 4-epoxy, 6-methylcyclohexene carboxylate, the adduct (c) used is that of two moles of pyromellitic anhydride and 1 mole of 2, 2-bis [4-(2-hydroxyethanoxy) phenyl] propane and the isocyanate adduct used is that of 5 moles of toluylene diisocyanate and 3 moles of trimethylol propane. Specifications 603,827, 711,279, 711,280, 783,555, 813,212 and 886,601 are referred to.