Process of dry adhesive-free thermal transfer of indicia
AssigneeMinnesota Mining and Manufacturing Company
InventorsRobert C. Fitzer, Frank L. Deyak, Charles J. Fabbrini
Life of this patent
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Abstract
A process and composition are provided that provide for thermal transfer of ink compositions and eliminate the need to prepare articles such as sign faces, particularly flexible sign faces, by painting with ink compositions that contain solvents. The present process and composition permit thermal transfer from a carrier to a receptor at low temperatures with the use of vacuum pressure. The transferred ink adheres tenaciously to the receptor and is flexible.
Claims22
A dry, adhesive-free process for transferring a dry thermally-transferable ink composition from a carrier to a receptor comprising the steps of:
- (a) providing a receptor and a carrier bearing a dry thermally-transferable ink composition and a vacuum frame having a vacuum bed, a top capable of covering the vacuum bed, a porous material on said top for contacting said carrier, and a source of heat above said porous material;
- (b) placing said receptor and said carrier on said vacuum bed so that said ink composition contact said receptor to form an interface therebetween;
- (c) adjusting said interface so that it is free from any wrinkles and closing said top so as to form a chamber;
- (d) evacuating substantially all of the air from said interface by means of vacuum to create a reduced pressure in said chamber and coform said ink composition to said ink composition to said receptor;
- (e) mantaining said reduced pressure and heating said ink composition and said receptor to a temperature, and for a time, sufficient to soften said ink composition, fuse said ink composition to said receptor and form an intimate bond thereto and transfer said ink from said carrier to said receptor;
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- (f) removing said carrier from said ink, thereby leaving said ink adhered to said receptor surface.
A process of manufacturing a sign face having a thermally-transferable ink composition applied to at least a portion of a receptor in a dry, adhesive-free manner, said process comprising the steps of:
- (a) providing a receptor and a carrier bearing a layer of a dry thermally-transferable ink composition and a vacuum frame having a vacuum bed, a top capable of covering the vacuum bed, a porous material on said top for contacting said carrier, and a source of heat above said porous material;
- (b) placing said receptor and said carrier on said vacuum bed so that said ink composition contacts said receptor to form an interface therebetween;
- (c) adjusting said interface so that it is free from any wrinkles and closing said top so as to form a chamber;
- (d) evacuating substantially all of the air from said interface by means of vacuum to create a reduced pressure in said chamber and conform said ink composition to said receptor;
- (e) maintaining said reduced pressure and heating said ink composition and said receptor surface to a temperature, and maintaining said temperature for a time, sufficient to soften said ink composition, fuse said ink composition to said receptor surface and form an intimate bond thereto and transfer said ink composition to said receptor surface;
- (f) cooling said ink composition and said receptor surface to a temperature sufficient to harden said ink composition and cause the adhesion of said ink composition to said receptor surface to be greater than the adhesion of said ink composition to said carrier;
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- (g) removing said carrier from said ink thereby leaving said ink adhered to said receptor surface.
Dependencies are inferred from the claim text.