Thermally expandable sheet

Patent metadata

Field	Value
Publication number	US-11097565-B2
Application number	US-201916389521-A
Country	US
Kind code	B2
Filing date	Apr 19, 2019
Priority date	Apr 27, 2018
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A thermally expandable sheet includes a base, a thermally expansive layer, and a color adjustment layer. The thermally expansive layer is provided on a first side of the base and includes a thermally expandable material that distends in accordance with an amount of heat absorbed, the heat being generated from a thermal conversion layer that includes a thermal conversion material that converts electromagnetic waves to heat. The color adjustment layer is provided on at least one of the thermally expansive layer and a second side of the base and includes a color adjusting agent. When the thermal conversion layer is provided on the color adjustment layer, the color adjustment layer reduces a visual difference in color between a first region where the thermal conversion layer is provided and a second region where the thermal conversion layer is not provided.

First claim

What is claimed is:

1. A thermally expandable sheet, comprising:
a base;
a thermally expansive layer provided on a first side of the base and including a thermally expandable material that distends in accordance with an amount of heat absorbed;
a color adjustment layer provided on at least one of the thermally expansive layer or a second side of the base and including a color adjusting agent; and
a thermal conversion layer provided on part of the color adjustment layer, the thermal conversion layer including a thermal conversion material that converts electromagnetic waves to heat,
wherein a color difference ΔE*ab between a first region where the thermal conversion layer is provided on the color adjustment layer and a second region of the color adjustment layer where the thermal conversion layer is not provided is 13.0 or less, the color difference ΔE*ab being calculated using an L*a*b* color system.

2. The thermally expandable sheet according to claim 1 , wherein the color difference ΔE*ab between the first region and the second region is 3.2 or less.

3. The thermally expandable sheet according to claim 1 , wherein the thermal conversion material includes at least one of carbon, lanthanum hexaboride, or cesium tungsten oxide.

4. A thermally expandable sheet, comprising:
a base;
a thermally expansive layer provided on a first side of the base and including a thermally expandable material that distends in accordance with an amount of heat absorbed;
a first ink receiving layer provided on the thermally expansive layer and including a color adjusting agent; and
a thermal conversion layer provided on part of the first ink receiving layer, the thermal conversion layer including a thermal conversion material that converts electromagnetic waves to heat,
wherein a color difference ΔE*ab between a first region where the thermal conversion layer is provided on the first ink receiving layer and a second region of the first ink receiving layer where the thermal conversion layer is not provided is 13.0 or less, the color difference ΔE*ab being calculated using an L*a*b* color system.

5. The thermally expandable sheet according to claim 4 , wherein the color difference ΔE*ab between the first region and the second region is 3.2 or less.

6. The thermally expandable sheet according to claim 4 , wherein the thermal conversion material includes at least one of carbon, lanthanum hexaboride, or cesium tungsten oxide.

7. The thermally expandable sheet according to claim 4 , further comprising:
a color adjustment layer provided on a second side of the base and including a color adjustment agent.

8. The thermally expandable sheet according to claim 4 , further comprising:
a second ink receiving layer provided on a second side of the base and including a color adjusting agent.

9. The thermally expandable sheet according to claim 4 , wherein:
the thermally expansive layer includes a plurality of layers, and
a layer located closest to the first ink receiving layer among the plurality of layers includes a color adjusting agent.

10. The thermally expandable sheet according to claim 4 , wherein the base includes a color adjusting agent.

11. A thermally expandable sheet, comprising:
a base; and
a thermally expansive layer provided on a first side of the base and including a thermally expandable material that distends in accordance with an amount of heat absorbed, the thermally expansive layer further including a color adjusting agent; and
a thermal conversion layer provided on part of the thermally expansive layer,
wherein a color difference ΔE*ab between a first region where the thermal conversion layer is provided on the thermally expansive layer and a second region of the thermally expansive layer where the thermal conversion layer is not provided is 13.0 or less, the color difference ΔE*ab being calculated using an L*a*b* color system.

12. The thermally expandable sheet according to claim 11 , wherein:
the thermally expansive layer includes a plurality of layers that include the thermally expandable material, and
the plurality of layers includes a layer located farthest from the base, and at least the layer located farthest from the base includes the color adjusting agent.

13. The thermally expandable sheet according to claim 11 , wherein the color difference ΔE*ab between the first region and the second region is 3.2 or less.

14. The thermally expandable sheet according to claim 11 , wherein the thermal conversion material includes at least one of carbon, lanthanum hexaboride, or cesium tungsten oxide.

15. The thermally expandable sheet according to claim 11 , wherein:
the base includes a colorant or a fluorescent brightener.

16. The thermally expandable sheet according to claim 1 , wherein the color difference ΔE*ab between the first region and the second region is 6.5 or less.

17. The thermally expandable sheet according to claim 1 , wherein the color difference ΔE*ab between the first region and the second region is 1.6 or less.

18. The thermally expandable sheet according to claim 4 , wherein the color difference ΔE*ab between the first region and the second region is 6.5 or less.

19. The thermally expandable sheet according to claim 4 , wherein the color difference ΔE*ab between the first region and the second region is 1.6 or less.

20. The thermally expandable sheet according to claim 11 , wherein the color difference ΔE*ab between the first region and the second region is 6.5 or less.

21. The thermally expandable sheet according to claim 11 , wherein the color difference ΔE*ab between the first region and the second region is 1.6 or less.

Assignees

• Casio Computer Co Ltd

Inventors

• Takahashi Hideki
• Horiuchi Yuji
• Motoyanagi Yoshimune
• Mitsui Satoshi

Classifications

• B41M3/06 Primary

  Veined printings; Fluorescent printings; Stereoscopic images; Imitated patterns, e.g. tissues, textiles · CPC title

• B32B29/007

  next to a foam layer · CPC title

• B29C44/3415

  Heating or cooling · CPC title

• B29K2105/048

  Expandable particles, beads or granules · CPC title

• B41M5/392

  Additives, other than colour forming substances, dyes or pigments, e.g. sensitisers, transfer promoting agents · CPC title