Toagosei Chemical Industry, Co., Ltd.

Nippon Steel Corporation

Yuko Takeuchi

Takashi Matsubara

Toshiro Hirose

Tadashi Tanaka

Tatsuro Obi

Akio Watanabe

A coated steel plate suitable for bonding with a polyamide adhesive comprising a steel plate having coated thereon (a) a composition comprising a thermosetting phenol resin and a bisphenol A type epoxy resin, the thermosetting phenol resin comprising the condensation product obtained on reacting under refluxing a phenol and formaldehyde in less than one mol per equivalent of the phenolic hydroxyl group in the presence of an alkali catalyst; (b) a composition comprising a thermosetting phenol resin and a bisphenol A type epoxy resin, the thermosetting phenol resin comprising the condensation product obtained by washing with water the condensation product obtained by reacting under refluxing a phenol and formaldehyde in less than one mol per equivalent of the phenolic hydroxyl group in the presence of an alkali catalyst and then heating the condensation product to temperatures above about 60.degree. C; (c) a composition comprising a thermosetting phenol resin and a bisphenol A type epoxy resin, the thermosetting phenol resin comprising the condensation product obtained by washing with water a condensation product obtained by reacting a phenol and formaldehyde in an amount more than about one mol per equivalent of the phenolic hydroxyl group under refluxing in the presence of an alkali catalyst and, then, further heating the condensation product to a temperature higher than about 60.degree. C with the addition of a phenol in an amount such that the total amount of the phenolic hydroxyl group is greater than one equivalent per mol of formaldehyde; or (d) mixtures thereof.

Steel plate coated with thermosetting phenol resin and bisphenol A type

A process for bonding steel sheets, e.g., into metallic cans, which comprises applying first a primer comprising 0.1 to 2.5 weight parts of a bisphenol type A epoxy resin having a mean molecular weight of more than about 800, preferably 2000 to 4000, and 1 weight part of thermosetting phenolic resin, which is obtained by heating an aqueous solution comprising phenol, orthocresol and formaldehyde in the presence of a catalyst and reacting them with each other under refluxing conditions, on the surface of the steel sheets, heating the resultant steel sheets, and then bonding the steel sheets with a polyamide, and a primer composition for use in the process.

Steel plate bonding process and primer composition

A coated metallic sheet adapted for use in making a can for foodstuff or other container. This sheet can be made by coating, upon a material sheet, a composition of a resol-type thermosetting phenolformaldehyde resin and a bisphenol 'A' type epoxy resin. In said phenol-formaldehyde resin, the ratio by weight of orthocresol to phenol is between 60:40 and 10:90. Said epoxy resin has a mean molecular weight of 800 or more and is used in an amount of 0.2 to 1.5 part by weight per 1 part by weight of said phenol-formaldehyde resin in said composition. This composition used for the sheet displays an excellent adhesiveness particularly with respective to the use of a polyamide type adhesive.

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Nagoya, Japan

Yuko Takeuchi