STEEL SHEET HAVING ALKALI-SOLUBLE LUBRICATING FILM, METHOD FOR PRODUCING SAME, AND COMPOSITION

摘要

The present invention provides a steel sheet which has an alkali-soluble lubricating film on the surface, wherein the lubricating film has a first layer that contains (A) a polyethylene oxide having a weight average molecular weight of 50,000-500,000 and (B) a copolymer of (X) a styrene hydrocarbon compound or an olefin hydrocarbon compound having 3 or more carbon atoms and (Y) a polymerizable unsaturated compound having a carboxylic acid anhydride group and/or a polymerizable unsaturated compound having a carboxy group, said compounds being copolymerizable with the compound (X), wherein some or all of the carboxylic acid anhydride groups and the carboxy groups contained in the copolymer may be ammonia-modified, imidized or blocked by an alcohol.

主权项

1. A steel sheet having an alkali-soluble lubricating film on a surface,
wherein the lubricating film has: a first layer which contains (A) polyethylene oxide with a weight average molecular weight of 50,000 to 500,000 and (B) a copolymer of (X) a styrene-based hydrocarbon compound or an olefin-based hydrocarbon compound with three or more carbon atoms and (Y) either or both of a polymerizable unsaturated compound having a carboxylic anhydride group and a polymerizable unsaturated compound having a carboxy group that is copolymerizable with (X), with carboxylic anhydride groups or carboxy groups in the copolymer being partially or wholly ammonia-modified, imidized, or blocked with an alcohol in some cases, and which contains (B) at a weight ratio relative to a total of (A) and (B) of greater than 5% by weight but less than 50% by weight; and a second layer which is formed of an oil layer containing an oil component with a kinematic viscosity of 3 to 32 mm2/s (at 40° C.) and provided on the first layer, and wherein a total adhesion amount of (A) and (B) is 0.1 to 1.0 g/m2, and an adhesion amount of the oil layer is 0.1 to 3.0 g/m2.