Reactive dye printing process
View Patent ↗A formulation and method of printing an ink or meltable ink layer having reactive dyes or mixtures of reactive dyes and disperse dyes as colorants. The ink or ink melt layer also includes an alkaline substance, a binder, and optionally, a heat-activated printing additive. Permanently bonded color images are provided by the reaction between the reactive dye and the final substrate, which may be any cellulosic, protein, or polyamide fiber material, or mixtures with polyester. Reaction occurs upon heat activation of the printed ink image.
1. A method of printing using a thermal printer, comprising the steps of:
a. applying an ink layer to a ribbon substrate, wherein said ink layer comprises a reactive dye, a binder material which is thermally meltable at an operating temperature of a thermal printer, and an alkaline material which promotes the reaction of said reactive dye with a printable substrate having an active hydrogen containing functional group available for reaction with said reactive dye;
b. supplying said thermal printer with said ribbon having said ink layer applied thereto;
c. thermally printing from said ink layer by said thermal printer and forming an image on an intermediate substrate;
d. subsequently transferring said image from said intermediate substrate to said printable substrate by the application of heat to said image and fixing said image to said printable substrate by the reaction of said reactive dye with said printable substrate.
2. A method of printing using a thermal printer as described in claim 1 , wherein said ink layer further comprises a heat activated printing additive which is not meltable at said operating temperature of said thermal printer, but which is meltable at a higher temperature than said operating temperature of said thermal printer, wherein, upon transferring the image, sufficient heat is applied to melt said heat activated printing additive, and said image is transported by said heat activated printing additive to said printable substrate.
3. A method of printing using a thermal printer as described in claim 2 , wherein said heat activated printing additive is urea.
4. A method of printing using a thermal printer as described in claim 3 , further comprising a release layer which is applied to a portion of said ribbon substrate, wherein a portion of said release layer is transferred by means of said thermal printer onto said intermediate substrate prior to printing said image onto said intermediate substrate, and wherein said portion of said release layer which is transferred onto said intermediate substrate prevents a reaction between said intermediate substrate and said reactive dye and promotes the release of the image from the intermediate substrate when the image is transferred from the intermediate substrate to the printable substrate.
5. A method of printing using a thermal printer as described in claim 1 , further comprising a release layer which is applied to a portion of said ribbon substrate, wherein a portion of said release layer is transferred by means of said thermal printer onto said intermediate substrate prior to printing said image onto said intermediate substrate, and wherein said portion of said release layer which is transferred onto said intermediate substrate prevents a reaction between said intermediate substrate and said reactive dye and promotes the release of the image from the intermediate substrate when the image is transferred from the intermediate substrate to the printable substrate.
6. A method of printing using a thermal printer as described in claim 2 , further comprising a release layer which is applied to a portion of said ribbon substrate, wherein a portion of said release layer is transferred by means of said thermal printer onto said intermediate substrate prior to printing said image onto said intermediate substrate, and wherein said portion of said release layer which is transferred onto said intermediate substrate prevents a reaction between said intermediate substrate and said reactive dye and promotes the release of the image from the intermediate substrate when the image is transferred from the intermediate substrate to the printable substrate.