Lubricated tinplate for drawing and ironing operation
AssigneeNational Steel Corporation
InventorsGordon L. Peters, John R. Smith
Life of this patent
Estimating the term…
Abstract
Tinplate container stock coated with a substantially uniform film of lubricant, the lubricant film consisting essentially of a citric acid ester lubricant in an amount of at least 1.8 grams per basebox, and a method for its use in drawing and ironing operations.
Claims14
In the drawing and ironing of tinplate stock wherein the stock material is provided with a lubricant coating prior to the drawing or cupping stage, the improvement comprising
- applying to the pre-drawn stock a substantially uniform film of lubricant consisting essentially of a citric acid ester having the structural formula ##STR3## wherein R.sub.1, R.sub.2 and R.sub.3 are individually selected from the group consisting of hydrogen and alcoholic residue containing 1-10 carbon atoms, R.sub.4 is selected from the group consisting of hydrogen and carbocylic acid radicals containing 1-10 carbon atoms, and at least one of R.sub.1, R.sub.2 and R.sub.3 is an alcoholic residue, the citric acid ester being present in a coating weight amount of at least 1.8 grams per basebox.
A tinplate container stock having a substantially uniform film of lubricant on at least one surface area thereof, said film consisting essentially of a citric acid ester lubricant having the structural formula ##STR4## wherein R.sub.1, R.sub.2 and R.sub.3 are individually selected from the group consisting of hydrogen and alcoholic residue containing 1-10 carbon atoms, R.sub.4 is selected from the group consisting of hydrogen and carbocylic acid radicals containing 1-10 carbon atoms, and at least one of R.sub.1, R.sub.2 and R.sub.3 is an alcoholic residue, in a coating weight amount of at least 1.8 grams per basebox.
A method of producing lubricated tinplate container stock especially useful in drawing and ironing operations wherein the tinplate stock is coated with a substantially uniform film of lubricant, the improvement wherein the lubricant film consists essentially of a citric acid ester lubricant having the structural formula ##STR5## wherein R.sub.1, R.sub.2 and R.sub.3 are individually selected from the group consisting of hydrogen and alcoholic residue containing 1-10 carbon atoms, R.sub.4 is selected from the group consisting of hydrogen and carbocyclic acid radicals containing 1-10 carbon atoms, and at least one of R.sub.1, R.sub.2 and R.sub.3 is an alcoholic residue, the coating weight of said citric acid ester being in an amount of at least 1.8 grams per basebox.
Dependencies are inferred from the claim text.