WO2001005600A1

WO2001005600A1 - Heat-shrinkable ink-jet recording material

Info

Publication number: WO2001005600A1
Application number: PCT/US2000/018721
Authority: WO
Inventors: Jodi A. Dalvey; Nabill F. Nasser
Original assignee: American Coating Technology, Inc.
Priority date: 1999-07-16
Filing date: 2000-07-10
Publication date: 2001-01-25

Abstract

The present invention includes a method for making a miniature article with a surface comprised of a water soluble polyester, and ink printed indicia, the indicia having sharp definition and having adherence to the surface. The method includes providing a heat shrinkable medium and applying a compatible, shrinkable, ink-receptive coating to the heat shrinkable medium.

Description

HEAT-SHRINKABLE INK-JET RECORDING MATERIAL

This Application is a Continuation-In-Part of U.S. Application

Ser. No. 09/416,356, filed October 12, 1999 which is a Continuation-In-Part of U.S. Application Serial No. 09/354,827, filed July 16, 1999. BACKGROUND OF THE INVENTION The present invention relates to a shrinkable medium for receiving ink and to a method for printing the shrinkable medium.

Miniature works of art, such as miniature pictures or miniature decorations on jewelry articles, date back to antiquity. The art of making miniature items of decoration is no longer generally performed by actually drawing or painting a small image on a small article. Instead, the small image, such as a photograph or a printed image, is produced by optically reducing the photograph to a much smaller scale, through a medium such as a microfilm frame.

One method of producing miniature articles takes advantage of shrink characteristics of certain heat-sensitive synthetic plastic film materials. One of these methods is described in U.S. Patent No. 4,102,456 ('456), which issued July 25, 1978. This patent describes a kit for three-dimensional plastic objects. The kit includes a pattern sheet which has an outline of a figure imprinted thereon and a shrinkable plastic sheet. The shrinkable plastic sheet is a biaxially-oriented polystyrene sheet with a thickness of about 0.01 millimeters. The shrinkable sheet is sufficiently transparent so that a figure on a pattern sheet can be seen through the plastic sheet. The outline and line details are then traced upon the upper surface of the plastic sheet with a suitable device such as permanent ink marker.

The sheet is then heated in an oven at a temperature of about 300°F for about thee minutes, whereupon the plastic softens and shrinks and the area of the plastic sheeting covered by the particulate material puffs or bulges outwardly. The object is then removed from the oven while the plastic is soft, and the areas surrounding the puffed portions are flattened, if necessary, to exaggerate and accentuate the three dimensional appearance. These shrinkable objects can be used to make play things such as humanoids or animal-like figures originating in a comic strip, a motion picture, or a television program. The character whose contours are printed on the shrinkable plastic sheet may be colored by a child using colored pencils, or other coloring articles. The coloring is performed prior to treatment in the oven.

U.S. Patent No. 4,461,793 ('793) issuing July 24, 1984, describes a printable coating for use with a heat shrinkable object such as has been described. The printable coating includes a saturated solvent-soluble polyester film forming resin, calcium carbonate, and a silicate compound. An additional pigment to produce an opaque coating in a selected color may also be included. The printable coating described in the '793 patent may receive inks that are generally used to print legends, and the coating can shrink up to 50% when applied to a plastic film without exhibiting wrinkling and without losing adhesion to the film. The coating has an excellent abrasion resistance. EP Application No. 899,121 Al, published March 3, 1999, describes a heat shrinkable ink jet recording medium and a method for preparing the medium so that the medium can be shrunk after printing to construct articles such as toys, jewelry, ornaments, art pieces, and so on. An ink jet printer is used to print the articles onto the medium using original designs created with commercially available software, images selected from clip art or downloaded from the Internet, scanned photographs, and so forth. The heat shrinkable ink jet recording media comprises a heat shrinkable base substrate, and a heat shrinkable ink jet-receptive coating layer applied to a printable surface of the base substrate. The base substrate and the ink jet-receptive coating layer, are shrinkable in uniform proportions in all directions.

The base substrate is a polystyrene or biaxially-oriented polypropylene. The ink jet ink-receptive coating layer comprises a flexible resin having a glass transition temperature which is lower than that of the substrate to which the coating is applied. The water absorptivity of the coating is greater than 50% by weight. The coating also includes an adhesion promoter that is a graft copolymer of hydroxy methylmethacrylate, or methylmethacrylate. SUMMARY OF THE INVENTION

One embodiment of the present invention includes a method for making an ink jet printed, shrinkable article. The method comprises providing a shrinkable substrate and providing a coating that comprises a film and a modified polyester resin. The coating is applied to the shrinkable substrate. Indicia are imparted to the coating with an ink jet printer. The coated substrate with the ink-based indicia is then shrunk without wrinkling. The coated substrate is capable of receiving ink from an ink jet printer.

Another embodiment of the present invention includes a miniature printed article. The miniature printed article comprises a shrinkable substrate and a shrinkable coating adhered to the substrate. The coating is comprised of a film and a modified polyester resin. The miniature also includes ink jet indicia on the coating. The coating is smooth and unwrinkled when the article is shrunken. One other embodiment of the present invention includes an ink j et printable coating that comprises a film and a modified polyester that overlays the film.

Another embodiment of the present invention includes a kit such as a kit for making jewelry or ornaments. The kit comprises a container and shrinkable ink jet printed articles that are enclosed within the container. Another embodiment of the present invention includes a miniature printed article that comprises a hollow shrinkable substrate with internal and external surfaces and a shrinkable coating adhered to the substrate on all of the surfaces. The coating is comprised of a film and a modified polyester resin. The miniature includes ink jet indicia on the coating. The coating is smooth and unwrinkled on the internal and external surfaces when the article is shrunken.

DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of one embodiment of a shrinkable article of the present invention.

Figure 2 is a cross-sectional view of another embodiment of a shrinkable article of the present invention. DETAILED DESCRIPTION

One embodiment of the present invention includes a method for making a miniature article with a surface comprised of a water soluble modified polyester, a film and ink printed indicia, the indicia having sharp definition and having adherence to an underlying heat shrinkable medium. The method includes providing the heat shrinkable medium and applying a compatible, shrinkable, ink-receptive coating to the heat shrinkable medium. The method includes optionally corona treating the surface of the heat shrinkable medium prior to application of the shrinkable coating. The shrinkable coating comprises a modified water soluble polyester resin material comprised of about 7 to 55% of a modified-polyethylene resin or polyester resin, 90% of which is at a glass transition temperature of 100° Centigrade and 10% of which is greater than the glass transition temperature of 100° Centigrade and a film. In one embodiment, the shrinkable coating comprises an ink receptive coating. The ink receptive coating comprisies a polyester polymer that is modified with polyvinyl alsohol and acrylic resin and cationic resinas a die fixing agent with a range of 0 to 70 percent by weight. One range embodiment is 0 to 40 percent. The shrinkable coating is applied to the shrinkable medium. The method further includes printing the applied shrinkable coating with an ink such as ink from an ink jet process. The method additionally includes heating the heat shrinkable medium and the shrinkable coating for about 2 to 10 minutes at a temperature within a range of about 300 +/- 10° F or subjecting to baking condisions to shrink the heat shrinkable medium and the shrinkable coating to a degree that is about 50 percent of their original size or less.

Another embodiment of the present invention includes a miniature article with an outer surface comprised of a substantially smooth, modified water soluble polyester. Miniature ink-printed indicia with a sharp definition are on the smooth outer surface. The ink-printed indicia include ink jet printed indicia. One cross-sectional view of the miniature article, illustrated at 10 in Fig. 1 comprises a heat shrinkable substrate 12, and a coating that comprises a film 14 that overlays the substrate 12 and a modified polyester overlay 16 that overlays the film 14. The coating and heat shrinkable medium shrink together so that the outer coated surface is smooth and not wrinkled and remains adhered to the substrate. The ink jet printed indicia on the coating have sharp definition both before and after shrinkage. The ink jet printed indicia are believed to be bound to the coating.

The shrinkable substrate 12 is, in one embodiment, in a form of a sheet of a shrinkable material such as polystyrene or biaxially-oriented polypropylene. The substrate is shrinkable in an "X" dimensional direction in an amount of up to about 61% and is shrinkable in a "Y" dimensional direction in an amount of up to about 41% after heating the base substrate at about 120 to 170° C typically and, for some embodiments, 300°C, for about five minutes. The "X" dimensional direction and the "Y" dimensional direction are perpendicular to each other and are in a plane formed by the substrate.

Concurrent with its shrinkage in the "X" and "Y" dimensional directions, is an expansion of the base substrate in a "Z" dimension direction that is perpendicular to the plane formed by the substrate. Upon heating, the base substrate not only shrinks in both the "X" and "Y" dimensional directions, but expands in a "Z" dimensional direction to become both dimensionally smaller in the "X" and "Y" dimensional directions, and thicker in the "Z" dimensional direction. The shrinkable coating must also shrink in accordance with this shrinkage pattern in order to avoid wrinkling.

In one embodiment, the shrinkable substrate 12 is corona treated. Corona treatment may, for some embodiments, improve adherence of the coating to the substrate. One embodiment of the method of the present invention includes applying a coating to the substrate that can receive an ink jet print, that is shrinkable, and that comprises a water-based polyester material. In one embodiment, the polyester resin coating overlay 16 employed is designated, NS- 244LX, or NS-282 or WAC-10 and is manufactured by Takamatsu Oil and Fat Company, Ltd., of Osaka, Japan. This material includes an n-propanol concentration of about 1.8% by weight, a modified polyester resin concentration of about 15% by weight, and a water concentration of about 83.2% by weight. This coating material has a boiling point of 100° C and a specific gravity of 1.032 at 20° C. The material is a white emulsion that has a slightly alcoholic odor.

Other embodiments of the present invention apply a coating which includes a polyester resin and a urethane resin and is known as WAC-15, also manufactured by Takamatsu Oil & Fat Co., Ltd. The WAC-15 is free of organic solvent. The viscosity of the coating is about 500 cps and is adjustable with care.

Another modified polyester resin overlay material that may be employed in the method of the present invention include a modified polyester resin designated NS-282LX, manufactured by Takamatsu Oil and Fat Company, Ltd., of Osaka, Japan. This coating material has a modified polyester concentration that forms a clear layer after drying and that has good jet ink absorption. The modified polyester has a good adhesion to polyester and polyvinyl chloride films. The coating is applied to a thickness of about 8 to 12 microns.

The 282 LX modified polyester resin has an appearance of a white emulsion and a modified polyester concentration of 15% +/-1 percent by weight. The viscosity of the modified polyester resin is less than 1000 centipoise at 25 °C. The resin pH at 25 °C is 4-6. The 282 LX resin is nonionic and may, for some embodiments, include n-propyl alcohol in a concentration of 2.0% by weight. At low temperatures, the viscosity increases dramatically. The viscosity is reduced by heating at 40°C.

Another coating embodiment utilizes a modified polyester resin known as NS-244LX, also manufactured by Takamatsu Oil and Fat Company, Ltd., of Osaka, Japan. This material has an n-propanol concentration of about 1.8% by weight, a modified polyester resin concentration of about 15% by weight, and water in a concentration of about 83.2% by weight. The specific gravity of this material is 1.032. The vapor density of the material is 5 +1- 1. The modified polyester resin material is soluble in water. All of the resins utilized in the present invention are water soluble and water based.

Another coating embodiment utilizes an emulsion resin that includes a linear polyester of high molecular weight, known as NS-246LX. The NS-246LX is also manufactures by Takamatsu Oil & Fat, Ltd. Of Osaka, Japan. The NS-246LX coating has good ink absorption and good ink fixation. The coating also includes polyvinylalcohol and resin, NS-246LX. This coating has a non-volatile content of about 15% by weight, a viscosity of 1000 cps at 25 degrees Centigrade, a color of milky white, a pH of 4 to 6. The coating is a nonionic coating and includes about 2% n-propyl alcohol. The coating is dried in a still environment at about 110 degrees Centigrade.

Another coating embodiment utilizes a linear polyester of high molecular weight, polyvinylalcohol and acrylic resin which is known as NS- 286LX and is manufactured by Takamatsu Oil & Fat Co., Ltd., of Kyutaro- machi Chuoh-ku, Osaka, Japan. The NS-286LX coating has good ink absorption and good ink fixation, especially for direct and acid dyes. The coating has a good adhesion to films such as polyester and does not bronze. The coating has a good water resistance, is resistant to curl after coating and has a lustrous surface. The coating is applicable as a thin layer, 4 to 12 microns. The coating has a non- volatile content of about 15% by weight; a viscosity of 1000 cps at 25 degrees Centigrade; a pH of 4-6 and contains about 2% normal propyl alcohol. This coating is dried at a temperature of about 110 degrees Centigrade, in still air. The coating is applicable by die coating, roller coating knife coating, blade coating, and kiss roll coating. Other modified polyester resin coating formulations that may be employed in the method and coating of the present invention include NS-63W, manufactured by Takamatsu Oil and Fat Company, as well as PES-513E, also manufactured by Takamatsu Oil and Fat Company. These modified polyester materials make a clear layer after drying on a substrate. Coatings prepared with the modified polyester resin materials have good ink absorption, including good absorption of ink used in ink jet printing. The coating embodiments prepared with these resins have good adhesion to films such as polyester and polyvinyl chloride. Coatings have good water resistance and may be layered to a relatively thin thickness, such as about eight to twelve microns. One other coating usable in the method of the present invention is a color changeable coaitng that is activated by temperatures , thermochromic, or UV light, photochromic, with and without ink jet receptive coating. Inks are obtained from Matsui in coatings activiated thermochromically. Photopia inks from Matsui are used in coatings activated photochromically.

Other method embodiments include a phosphorescent pigment that is coated without an ink receiving layer; a product with an ink jet coating on one side that incorporates the phosphorescent pigments; and a product with ink jet coating on one side and the phosphorescent pigments incorporated in a polymer matrix on the other side.

Phosphorescent pigments usable in the present invention include doped zinc sulfide pigments and strontium sulfide pigments. Manufacturers include Allied Signal, UMC, USR, Matsui and WC Manufacturing.

In the method of the present invention, a film 14 such as polyester or polyvinyl chloride is overlayed on the shrinkable substrate 12. The modified polyester 16 is applied over the film. The film aids in adhering the modified polyester to the shrinkable medium. The modified polyester permits the shrinkable article to be ink jet printed.

The viscosity of the modified polyester resin coating material is less than 1,000 cps at 25°C. Viscosity modifiers may be added for some embodiments. Particular coating methods require viscosities that range from about 25 cps to as great as about 20,000 cps. The pH of the modified polyester resin-based coating ranges from about 4 to 6 for the NS244LX and NS282LX coating formulations, which are nonionic resins. The pH for the NS122L modified polyester resin-based coating, which comprises an anionic polyester resin, is about 7. The anionic polyester resins may be altered by addition of a surfactant such as n-propanol in a concentration of about 2.0% by weight. The nonionic resins do not include an n-propanol composition. Coatings made with the modified polyester resins dry at about 110° C in about three minutes.

The modified polyester resin coating formulations may optionally be altered with an addition of a surfactant or a pigment or a plasticizer for special colors or effects. A surfactant may be used in order to enhance wetting properties and adhesive properties of the coating. The coating may be shrunk to a maximum of about 50% of its application area in an X-Y plane. In particular, the modified polyester resin coating is compatibly shrinkable to the shrinkable substrate. In one embodiment illustrated at 20 in Figure 2, the substrate 12a is coated as shown at 16a and 16b. The coating 16a and 16b overlays film 14 a and 14b. The coating 16a is an internal coating. The coating 16b is an external coating. The coating may be uniform or different coatings may be used on different sides. Coating on both sides provides improved shrinkage balance over the entire substrate 12a.

Inkjet printing uses jets of colored ink, similar in appearance and consistency to fountain pen ink. The ink is ejected through a nozzle under pressure and is transformed into uniform droplets by vibration of a piezoelectric crystal. The droplets are charged electrostatically and are deflected by a computer or other digital image-generating device. Any type of ink jet printing may be used in the method of the present invention. Methods include a computer activated single nozzle, a bank of nozzles, bubblejet and phase-change technology. Indicia printed on the shrinkable coated surface include letters as well as color or luminescent images. Ink for the color images includes dyes that have different spectral and reflective characteristics from pigments. Images also include holographic images and images that glow in the dark.

Inkjet printing typically requires a surface that has a capacity to dry the impinging drops of ink by absorption without wicking or spreading of the ink for maximum printing density and sharpness. It has surprisingly been found that the coating used in the process and article of the present invention receives ink jet print and does not require a material such as silica or calcium carbonate to impart clarity and sharpness of the indicia. Ink jet printing may be used to make indicia such as letters, symbols, or dots used to make an image such as a face or an animal or other image. Print from the ink jet printing may have a variety of colors. Print may be used to make holograms. Print, for some embodiments, glows in the dark.

In another embodiment, a magnetic substrate is laminated to the back of the film. In another embodiment, a magnetic coating is applied to the back of the film.

Articles made with the method of the present invention include but are not limited to articles such as toys, figures, two-dimensional images, and other articles that may be miniaturized. Other articles include kits such as jewelry kits and ornaments and ornament kits such as Christmas tree ornament kits. A jewelry kit and ornament kit comprises a shrinkable article of the present invention, a container for the shrinkable article and, optionally coloring agents such as crayons or paint, fastening devices, and other kit components, such as components that attach one shrinkable article to another.

One other embodiment is made by laminating a magnetic substrate to the back of a film or coating or applying a magnetic coating to the back of a film or coating. Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is understood that other variations are contemplated as being within the scope of the present invention. Accordingly, the present invention is not limited in the particular embodiments which have been described in detail therein. Rather, reference should be made to the appended claims as indicative of the scope and content of the present invention.

Claims

What is claimed is:

1. A method for making an ink jet printed, shrinkable article, comprising: providing a shrinkable substrate; providing a coating comprising a water soluble modified polyester resin; applying the coating to the shrinkable substrate; imparting indicia to the coating with an ink jet printer; and shrinking the coated substrate with the ink-based indicia without wrinkling.

2. The method of claim 1 wherein the shrinking occurs when the coated substrate is heated.

3. The method of claim 1 and further comprising drying the coated substrate after shrinking.

4. The method of claim 1 wherein the coating is applied to a thickness of about seven microns.

5. The method of claim 1 wherein the coated substrate is shrunk to a size that is about one-half of its original size.

6. The method of claim 1 wherein the coating further comprises a film.

7. The method of claim 1 wherein the film is applied to the shrinkable substrate under the modified polyester resin.

8. The method of claim 1 wherein the imparted indicia comprise holographic images or glow in the dark images.

9. The method of claim 1 wherein the coating comprises a phosphorescent pigment.

10. The method of claim 1 and further comprising using a polyester polymer and modifying the polymer with polyvinyl alcohol and acrylic resin and cationic resin as a dye fixing agent to make a coating composition.

11. The method of claim 10 wherein the dye fixing agent has a concentration of up to 70 percent by weight of the polyester polymer.

12. The method of claim 1 wherein the coating comprises color changeable capability with changes in temperature or with changes in UV light.

13. The method of claim 12 wherein the coating is usable with an ink jet receptive coating.

14. The method of claim 12 wherein the coating is usable without an ink jet receptive coating.

15. The method of claim 1 and further comprising laminating a magnetic substrate to the back of the film.

16. The method of claim 1 and further comprising applying a magnetic coating to the back of the film.

17. A miniature, printed article, comprising: a shrinkable substrate; a shrinkable coating adhered to the substrate, the coating comprised of a water soluble polyester resin; and ink jet indicia on the coating; wherein the coating is smooth and unwrinkled when the article is shrunken.

18. The miniature article of claim 17 wherein the coating is free of a pigment.

19. The miniature article of claim 17 wherein the ink jet indicia have a sharp appearance.

20. The miniature of claim 17 wherein the coating has a thickness of not more than about 10 microns.

21. The miniature of claim 17 wherein the indicia are comprised of colored ink.

22. The miniature of claim 17 wherein the indicia are comprised of letters.

23. A shrinkable, ink j et printable coating comprising: a film and a modified polyester resin that overlays the film.

24. The coating of claim 23 wherein the film comprises polyester

25. The coating of claim 23 wherein the film comprises polyvinyl chloride.

26. The coating of claim 23 wherein the modified polyester resin is ink jet printable.

27. The miniature of claim 17 wherein the article is a toy.

28. A kit comprising: a container; and and an ink jet printable, shrinkable article enclosed within the container.

29. The kit of claim 28 wherein the kit is a jewelry kit.

30. The kit of claim 28 wherein the kit is an ornament kit.

31. The miniature of claim 17 wherein the ink j et indicia make a holographic image.

32. The miniature of claim 17 wherein the ink jet indicia make an image that glows in the dark.

33. The method of claim 1 wherein the article is coated on all surfaces.

34. The method of claim 1 wherein the article is coated on one surface.

35. A method for making an ink jet printed, hollow shrinkable article, comprising: providing a hollow shrinkable substrate with an internal surface and an external surface; providing a coating comprising a water soluble modified polyester resin; applying the coating to the hollow shrinkable substrate on or over the internal surface and the external surface; imparting indicia to the coating with an ink jet printer; and shrinking the coated hollow substrate with the ink-based indicia without wrinkling.

36. A miniature, printed article, comprising: a hollow, shrinkable substrate with an internal surface and an external surface; a shrinkable coating adhered to the substrate, on or over the internal surface and the external surface; and ink jet indicia on the coating wherein the coating is smooth and unwrinkled when the article is shrunken.

37. The printed article of claim 17 and 36 wherein the coating comprises a polyester polymer that is modified with polyvinyl alcohol and acrylic resin and cationic resins as dye fixing agents.

38. The printed article of claim 17 and 36 and further comprising a phosphorescent pigment in the coating.

39. The printed article of claim 38 wherein phosphorescent pigments are in one coating portion of the article.

40. The printed article of claim 17 and 36 and further comprising a magnetic substrate laminated to the coating.

41. The printed article of claim 17 and 36 and further comprising a magnetic coating applied to the coating.