Heat-Sensitive record material
The invention describes a heat sensitive recording material comprising a paper or film substrate having coated thereon a thermally sensitive color forming composition. The thermally sensitive color forming composition comprises a chromogenic dye precursor, and an acidic developer material. A high hydrolysis adhesive material is advantageously employed as a basecoat or in the color forming composition. The high hydrolysis adhesive material has a hydrolysis of at least 99% and yields a heat sensitive recording material of low background discoloration which is useful in wet offset UV cured printing.
1 . A non-topcoated heat-sensitive recording material comprising a substrate having coated thereon a thermally sensitive color forming composition in one or more layers, the thermally sensitive color forming composition comprising a chromogenic dye precursor, and an acidic developer material, and a binder material, the binder material comprising a high hydrolysis adhesive material having a hydrolysis degree of at least 99%.
2 . The heat sensitive recording material according to claim 1 wherein the binder material comprises a basecoat positioned between the thermally sensitive color forming composition and the substrate.
3 . The heat sensitive recording material according to claim 2 wherein-the basecoat comprises a blend of a high hydrolysis adhesive and a latex.
4 . The heat sensitive recording material according to claim 1 wherein the high hydrolysis adhesive material is a hydrolyzed polyvinyl alcohol.
5 . The heat sensitive recording material according to claim 1 wherein the high hydrolysis adhesive material has a hydrolysis of at least 99.3%.
6 . The heat sensitive recording material according to claim 4 wherein the high hydrolysis adhesive material has a hydrolysis of at least 99.5%.
7 . The heat sensitive recording material according to claim 1 wherein the high hydrolysis adhesive material is blended into one or more layers of the thermally sensitive color forming composition.
8 . The heat sensitive recording material according to claim 1 wherein the high hydrolysis adhesive material comprises a basecoat under the thermally sensitive color forming composition.
9 . The heat sensitive recording material according to claim 1 wherein one or both of the color forming composition and basecoat comprises in addition an oil absorptive pigment having an oil absorption of at least 50 ml/100 g.
10 . The heat sensitive recording material according to claim 1 wherein one or both of the color forming composition and basecoat comprises in addition an insulating hollow sphere material or porous plastic pigment.
11 . A non-topcoated heat-sensitive recording material comprising a substrate having coated thereon a thermally-sensitive color forming composition in one or more layers, the thermally sensitive color forming composition comprising a chromogenic dye precursor, an acidic developer material and a binder material, and at least 4% by weight of the binder material comprising a hydrolyzable vinyl ester having a hydrolysis of degree of 99% or greater.
12 . The heat sensitive recording material according to claim 11 wherein the binder material is a hydrolysable vinyl ester and comprises in addition a basecoat under the thermally sensitive color forming composition, the basecoat comprising a hydrolysable vinyl ester having a degree of hydrolysis of 99% or greater.
13 . The heat sensitive recording material according to claim 11 wherein the binder material is a hydrolyzed polyvinyl alcohol.
14 . The heat sensitive recording material according to claim 11 wherein the binder material has a hydrolysis of at least 99.3%.
15 . The heat sensitive recording material according to claim 13 wherein the binder material has a hydrolysis of at least 99.5%.
16 . The heat sensitive recording material according to claim 11 wherein the binder material is blended into one or more layers of the thermally sensitive color forming composition.
17 . The heat sensitive recording material according to claim 12 wherein one or both of the color forming composition and basecoat comprises in addition an oil absorptive pigment.
18 . The heat sensitive recording material according to claim 12 wherein one or both of the color forming composition and basecoat comprises in addition an insulating hollow sphere material with a void volume of at least 40%.
19 . The heat sensitive recording material according to claim 12 wherein the basecoat comprises as oil absorptive pigment or insulating hollow sphere material.
20 . The heat sensitive recording material according to claim 12 wherein the basecoat comprises in addition a latex material.
21 . The heat sensitive recording material according to claim 11 wherein the heat sensitive composition comprises in addition a basecoat positioned between the thermally sensitive color forming composition and the substrate.