IPC分类号：
B44F1/02 | B44C1/17 | B44F1/00 | D06Q1/12 | D06Q1/00 | D06Q1/10 | G02B5/128 | G02B5/12 | B44F1/12 | G08B5/00 | B32B5/16
当前申请(专利权)人：
MINNESOTA MINING AND MANUFACTURING COMPANY
原始申请(专利权)人：
MINNESOTA MINING AND MANUFACTURING COMPANY
当前申请(专利权)人地址：
P.O. BOX 33427, 55133-3427, ST. PAUL, MINNESOTA
代理机构：
GRISWOLD, GARY L. KIRN, WALTER N. HANSON, KARL G.
摘要：
A transfer sheet material for forming retroreflective graphic images on a substrate, the sheet material comprising a monolayer of transparent microspheres; a color layer printed over the microspheres in a first graphic segment of the sheet material in an imagewise pattern, the color layer comprising a colorant in a transparent resin; a reflective layer printed over the microspheres in a second graphic segment of the sheet material in an imagewise pattern, the reflective layer comprising reflective flakes in a transparent binder, wherein the microspheres are partially embedded in at least one of the color layer and the reflective layer, individual microspheres having the reflective flakes arranged in cup-like fashion about their embedded portions; and a bonding layer printed over the color layer and the reflective layer, the bonding layer being sufficiently thick to embed all exposed surfaces of the color layer and the reflective layer and being adapted for use in securing the sheet material to a substrate. Also, a method for making such a sheet material. Also, a sheet material having the color layer and the reflective layer combined as a single layer. Also, a sheet material having a graphic segment in which a specularly reflective metal layer is deposited over the microspheres.
技术问题语段：
Insofar as known, no one has previously found a practical or commercially useful way to provide such retroreflective emblems.|Some have proposed silk-screening a design onto a garment, and then while the design is still wet, cascading microspheres onto the design; but such an approach is messy, usually provides a nonuniform deposit of microspheres, and is impractical for obtaining high reflective brightness (which requires that the embedded surfaces of the microspheres be covered with a specularly reflective layer).|Still others long ago proposed the preparation of retroreflective decals comprising a layer of glass microspheres disposed over a printed design (see U.S. Pat. No. 2,422,256 (Phillippi)); but the suggested decal was a several-layer product which was likely stiff and unsuited for conformable garments.|But none of these commercial products is useful to form the complex multi-colored designs that are in fashion and are needed to maximize the use of retroreflective emblems.|The result is that, in spite of the above-described efforts, multi-colored designs or emblems on garments continue to be made non-retroreflective and the potential use of such emblems for safety purposes goes unrealized.
技术功效语段：
Sheet materials of the invention can be used to provide substrates with graphic images comprising non-reflecting colored areas and retroreflective areas, with at least some of the retroreflective areas typically being capable of brilliantly retroreflecting the color of the image provided in these areas. Fabric substrates comprising such transferred graphic images can exhibit good wash durability (i.e., launderability) and can also exhibit good drycleaning durability.
权利要求：
What is claimed is:
1. A transfer sheet material for forming retroreflective graphic images on a substrate, the sheet material comprising:
a) a monolayer of transparent microspheres;
b) a color layer printed over the microspheres in a first graphic segment of the sheet material in an imagewise pattern, the color layer comprising a colorant in a transparent resin;
c) a reflective layer printed over the microspheres in a second graphic segment of the sheet material in an imagewise pattern in such a manner that any overlapping areas of the first and second graphic segments are characterized by the color layer being disposed between the microspheres and the reflective layer, the reflective layer comprising reflective flakes in a transparent binder, wherein the microspheres are partially embedded in at least one of the color layer and the reflective layer, the reflective flakes being small enough relative to the microspheres that individual microspheres have the reflective flakes arranged in cup-like fashion about their embedded portions; and
d) a bonding layer printed over the color layer and the reflective layer, the bonding layer being sufficiently thick to embed all exposed surfaces of the color layer and the reflective layer and being adapted for use in securing the sheet material to a substrate.
2. The sheet material of claim 1 further comprising a second color layer printed in the first graphic segment in an imagewise pattern, the second color layer comprising a second colorant in a second transparent resin.
3. The sheet material of claim 1 bonded to a substrate through the bonding layer.
4. The sheet material of claim 3 wherein the substrate is a fabric.
5. The sheet material of claim 1 wherein the reflective flakes are selected from the group consisting of metal flakes, plastic flakes, metal-plated plastic flakes, and nacreous pigment particles.
6. The sheet material of claim 1 wherein the reflective flakes have a thickness in the range of about 0.03 to about 0.8 microns.
7. The sheet material of claim 1 further comprising a carrier comprising a base sheet and a heat-softenable layer on the base sheet, the microspheres being embedded in the heat-softenable layer to a depth averaging between about 25 and about 50 percent of their diameters.
8. The sheet material of claim 7 wherein the microspheres are embedded in the heat-softenable layer to a depth averaging between about 40 and about 50 percent of their diameters.
9. The sheet material of claim 1 wherein the colorant comprises a transparent pigment.
10. The sheet material of claim 1 wherein the colorant comprises a transparent dye.
11. The sheet material of claim 1 wherein the transparent resin is selected from the group consisting of polyester resins and polyurethane resins.
12. The sheet material of claim 1 wherein the transparent binder is selected from the group consisting of polyester binders and polyurethane binders.
13. The sheet material of claim 1 wherein the color layer and the reflective layer at least partially overlap, the color layer being disposed between the microspheres and the reflective layer to provide a segment of the sheet material which is capable of retroreflecting the color of the color layer when the microspheres in this segment are illuminated with a beam of incident light.
14. The sheet material of claim 1 wherein the bonding layer comprises an extender resin and a heat-activatable, hot-melt adhesive powder fused into the extender resin.
15. The sheet material of claim 14 wherein the extender resin is selected from the group consisting of polyester extender resins and polyurethane extender resins.
16. The sheet material of claim 14 wherein the hot-melt adhesive powder comprises a polymeric material selected from the group consisting of polyesters and polyamides.
17. A transfer sheet material for forming retroreflective graphic images on a substrate, the sheet material comprising:
a) a monolayer of transparent microspheres;
b) a first colored reflective layer printed over the microspheres in a first graphic segment of the sheet material in an imagewise pattern, the first colored reflective layer comprising a colorant and reflective flakes in a transparent resin, wherein the microspheres are partially embedded in the first colored reflective layer, the reflective flakes being small enough relative to the microspheres such that individual microspheres have reflective flakes arranged in a cup-like fashion about the embedded portions of the microspheres;
c) a second colored reflective layer printed over the microspheres in a second graphic segment of the sheet material in an imagewise pattern, the second colored reflective layer comprising a colorant and reflective flakes in a transparent resin, wherein the microspheres are partially embedded in the second colored reflective layer, the reflective flakes being small enough relative to the microspheres such that individual microspheres have reflective flakes arranged in a cup-like fashion about the embedded portions of the microspheres; and
d) a bonding layer printed over the first and second colored reflective layers, the bonding layer being sufficiently thick to embed all exposed surfaces of the colored reflective layers and being adapted for use in securing the sheet material to a substrate.
18. The sheet material of claim 17 wherein the reflective flakes comprise metal flakes.
19. The sheet material of claim 17 wherein the reflective flakes comprise aluminum flakes.
20. The sheet material of claim 17 further comprising:
e) a layer of specularly reflective metal adhered to the microspheres in a third graphic segment of the sheet material in an imagewise pattern, the bonding layer being printed over the specularly reflective metal in the third graphic segment, the bonding layer being sufficiently thick to embed all exposed surfaces of the specularly reflective metal layer.
21. The sheet material of claim 20 wherein the specularly reflective metal comprises aluminum.
22. A transfer sheet material for forming retroreflective graphic images on a substrate, the sheet material comprising:
a) a monolayer of transparent microspheres;
b) a layer of specularly reflective metal adhered to the microspheres in a first graphic segment of the sheet material in an imagewise pattern;
c) a color layer printed-over the microspheres in a second graphic segment of the sheet material in an imagewise pattern, the color layer comprising a colorant in a transparent resin;
d) a reflective layer printed over the microspheres in a third graphic segment of the sheet material in an imagewise pattern in such a manner that any overlapping areas of the second and third graphic segments are characterized by the color layer being disposed between the microspheres and the reflective layer, the reflective layer comprising reflective flakes in a transparent binder, wherein the microspheres in the second and third graphic segments are partially embedded in at least one of the color layer and the reflective layer, the reflective flakes being small enough relative to the microspheres that individual microspheres have the reflective flakes arranged in a cup-like fashion about their embedded portions; and
e) a bonding layer printed over the color layer, the reflective layer, and the specularly reflective metal layer, the bonding layer being sufficiently thick to embed all exposed surfaces of the color layer, the reflective layer, and the specularly reflective metal layer, and being adapted for use in securing the sheet material to a substrate.
23. The transfer sheet material of claim 17, wherein the colorant comprises a pigment or dye.