Patent GB-811951-A (GB)
Title: Coating sheet metal containers
IPC: C23F15/00
Filed: 1957-01-14
Abstract: Soldered seams of containers, e.g. tinplate or blackplate, cans for foods and beverages are coated by applying thereto a substantially unreacted mixture of a polyamine resin and a polyepoxide polyether resin dissolved in a volatile organic solvent, the proportion of the former resin being between 45 and 65 per cent of the total weight of resins, which are caused to react together, and cured, by the heat of the soldering operation. The resins may be applied before, during or immediately after the soldering operation.  The polyepoxide polyether resin may be prepared by reacting resorcinol, catechol, hydroquinone, methyl resorcinol, p-p1-dihydroxy - diphenyl - 2 - 21 - propane, 4 - 41 - dihydroxybenzophenone, bis - 4 - hydroxyphenyl methane, 1 - 11 - bis - 4 - hydroxyphenyl ethane, 2 - 21 - bis (4 - hydroxy - 2 - methyl-phenyl) propane, 2 - 21 - bis (4 - hydroxy - 2-tertiarybutylphenyl) propane, 2 - 21 - bis (2-hydroxynaphthyl) pentane or 1-5-dihydroxynaphthalene with epichlorhydrin or dichlorhydrin, or mixtures thereof in a basic medium, and its average molecular weight must be between 600 and 2300 and its epoxide equivalent value between 300 and 1500.  The polyamine resin may be prepared from a polymeric unsaturated fatty acid, e.g. di-linoleic acid and an aliphatic polyamine, e.g. ethylene diamine, propylene diamine, butylene diamine or diethylene triamine and must have an average molecular weight between 2000 and 6000, and an amine equivalent value of 200 to 800 as determined by titration with aqueous hydrochloric acid.  The compositions may include pigments, dyes and waxes.ALSO:Soldered seams of containers, e.g. tinplate or black plate cans for foods and beverages are coated by applying thereto a substantially unreacted mixture of a polyamine resin and a polyepoxide polyether resin dissolved in a volatile organic solvent, the proportion of the former resin being between 45 and 65 per cent of the total weight of resins, which are caused to react together, and cured, by the heat of the soldering operation. The resins may be applied before, during or immediately after the soldering operation. The polyepoxide polyether resin may be prepared by reacting resorcinol, catechol, hydroquinone, methyl resorcinol, p-p1-dihydroxy - diphenyl - 2 - 21 - propane, 4 - 41-dihydroxybenzo - phenone, bis - 4 - hydroxyphenyl methane, 1 - 11 - bis - 4 - hydroxyphenyl ethane, 2 - 21 - bis - (4 - hydroxy - 2-methylphenyl) propane, 2 - 21 - bis - (4 - hydroxy - 2 - tertiarybutylphenyl) propane, 2 - 21-bis - (2 - hydroxynaphthyl) pentane or 1 - 5-dihydroxynaphthalene with epichlorhydrin or dichlorhydrin or mixtures thereof in a basic medium and its average molecular weight must be between 600 and 2300.  The polyamine resin may be prepared from a polymeric unsaturated fatty acid, e.g. di-linoleic acid and an aliphatic polyamine, e.g. ethylene diamine, propylene diamine, butylene diamine or diethylene triamine and must have an average molecular weight between 2000 and 6000, and an amine equivalent value of 200 to 800 as determined by titration with aqueous hydrochloric acid.  The compositions may include pigments, dyes and waxes.