MXPA99008789A

MXPA99008789A - Thermal dye diffusion coating and substrate

Info

Publication number: MXPA99008789A
Application number: MXPA/A/1999/008789A
Authority: MX
Inventors: Joseph Kronzer Francis
Original assignee: Kimberlyclark Worldwide Inc
Priority date: 1997-03-31
Filing date: 1999-09-24
Publication date: 2000-02-02

Abstract

A coating suitable for receiving an image by dye diffusion printing which includes a thermoplastic polymer having a glass transition temperature of at least about 30°C and a powdered plasticizer having a melting point of at least about 80°C. The thermoplastic polymer may have a glass transition temperature of at least about 40°C. For example, the thermoplastic polymer may be a vinyl chloride-acrylate copolymer. The plasticizer may be an aromatic carboxylicacid ester, such as cyclohexane dimethanol dibenzoate. The average particle size of the powdered plasticizer may be no greater than about 20 micrometers. The weight ratio of the thermoplastic polymer to the plasticizer typically is in a range of from about 80:20 to about 40:60. Finally, the coating includes a release agent. The release agent may be present in a range of from about 0.5 to about 10 percent by weight, based on the weight of dry coating. The present invention also provides a coated substrate suitable for receiving an image by dye diffusion printing and a coating composition which is an aqueous dispersion of a thermoplastic polymer having a glass transition temperature of at least about 30°C, a powdered plasticizer having a melting point of at least about 80°C, and a release agent.

Description

COATING OF THERMAL DYEING AND SUBSTRATE Background of the Invention The present invention relates to the printing d diffusion of thermal dye.

The thermal dye diffusion printing is a non-impact electronic printing process which is able to give almost photographic quality prints. An image is formed by using a thermal head to transfer dye from a colored ribbon to a surface of a receiver. The head consists of a line of individually steerable heated elements to which appropriate electrical impulses are fed to generate the amount of heat required to provide the amount of dye transfer needed to reproduce the corresponding pixel in the image. The temperature of the surface of the thermal head is typically 350 degrees centigrade and the duration of the heating pulse typically is up to 10 milliseconds. The depth of the shadow is governed by the length of the heating pulse and a complete colo image is constructed in a normal way by transferring the primary colors one over each other.

In general, both the tape and the receiver should have very smooth surfaces. The active layer of the tape consists of a solid solution of dye in a binder. The receiver typically consists of a polymer coating on either paper or other support material; The coating is designed to be receptive to the dye and to release gently from the tape, or from the dye layer, after printing.

The receiver is held on a plate roller and the thermal head is pressed against the surface of the belt. The two media are held together under a pressure of between 10 and 100 atmospheres. As the surfaces are very smooth, there is no air separation between the medium and the region where the thermal head is applying maximum pressure. The dye is transferred by means of a base transfer and diffusion; The dye which is dissolved in the dye layer is divided into the receptor coating by means of a molecular diffusion process. Once the dye is in the receiver coating, it is free to continue to diffuse further into the coating as long as the thermal head temperature remains high enough. In all phases, the dye molecules are surrounded by a polymer matrix; the transfer occurs from one polymer phase to another without sublimation taking place.

Because the dyes are always constrained by the polymer molecules, the dye diffusion process is very well controlled. The construction of color is defined and diffusion to the sides can not occur, as is possible in the air separation of a sublimation process.

Although the films have the required degree of smoothness, the accumulation of a static charge on the film can occur during the printing process which leads to the attraction of the dust particles on the surfaces of the film. The presence of the powder on a receiving coating prevents intimate contact over the entire area of the thermal print head which results in imperfections in the printed image. Even though papers generally do not suffer from static charge buildup, image quality may be reduced. In addition, the transfer of the printed image to another substrate can be adversely affected by the use of the paper carrier or the support for the receiver coating. Therefore, there is a need for improved thermal dye diffusion substrates, particularly for substrates intended to be used as a heat transfer material.

Synthesis of the Invention The present invention relates to some of the difficulties and problems discussed above by providing a coating suitable for receiving an image by dye diffusion printing. The coating includes a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade. For example, the thermoplastic polymer may have a glass transition temperature of at least about 40 degrees centigrade. As another example, the thermoplastic polymer can be a vinyl acrylate-chlorur polymer.

The coating also includes a powder plastificant having a melting point of at least about 80 degrees centigrade. For example, the plasticizer can be an aromatic carboxylic acid ester.

As another example, the plasticizer may be a cyclohexane dimethanol dibenzoate. As a further example, the average particle size of the powder plasticizer may not be greater than about 20 microns. The weight ratio of the thermoplastic polymer to the plasticizer is typically in a range of from about 80:20 to about 40:60. For example, the weight ratio of the thermoplastic polymer to the plasticizer can be from about 70:30 to about 50:50.

Finally, the coating includes a release agent. The release agent may be present in a range of from about 0.5 to about 10 percent per weight, based on the dry weight of the coating.

The present invention also provides a coated substrate suitable for receiving an image by dye diffusion printing. The coated substrate includes a first flexible layer which has the first and second surfaces and is selected from the group consisting of films, fibrous sheet-like materials and combinations thereof. For example, the first layer can be a movie. As another example, the first layer may be a fibrous sheet type material.

The present invention further provides a coated substrate suitable for receiving an image by dye diffusion printing which includes a first flexible layer as described; a second layer lying on the first surface of the first layer, the second layer comprises a first thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade and a first powder plasticizer having a point of melted at least about 80 degrees Celsius; and a third layer lying on the second layer, whose third layer includes a second thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, a second powder plasticizer having a melting point of at least about 80 degrees centigrade and a release agent.

The first layer has a basis weight of from about 50 to about 200 grams per square meter. For example, the first layer can be a movie. As a further example, the first layer may be a fibrous sheet type material. The second layer has a basis weight of from about 0.5 to about 10 grams per square meter, and the third layer has a basis weight of from about 0.5 to about 10 grams per square meter.

The ratio by weight of the first thermoplastic polymer to the first plasticizer is in the range of from about 80:20 to about 40:60 and the ratio by weight of the second thermoplastic polymer to the second plasticizer is in a range of about 80: 20 at around 40:60. The release agent is present in the third layer in a range of from about 0.5 to about 10 weight percent, based on the weight of the third layer coating.

By way of illustration only, the first thermoplastic layer can have a glass transition temperature of at least about 40 degrees centigrade. For example, the first thermoplastic polymer can be an acrylate-vinyl chloride copolymer. Similarly, the second thermoplastic polymer can have a glass transition temperature of at least about 40 degrees centigrade and can be an acrylate-vinyl chloride copolymer. The first powder plasticizer can be an aromatic carboxylic acid ester, such as cyclohexane dimethanol dibenzoate. The average particle size of the prime powder plasticizer can be, for example, not greater than about 20 microns. In a similar manner, the second powder plasticizer may be an aromatic carboxylic acid ester, such as cyclohexane dimethanol dibenzoate and may have an average particle size no greater than about 20 microns.

Finally, the present invention provides a coating composition which is an aqueous dispersion of a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, a powdery plasticizer having a melting point of at least about 30 degrees Celsius. at least about 80 degrees Celsius, and a release agent. The weight ratio of the thermoplastic polymer to the powder plasticizer is in a range of from about 80:20 to about 40:60, on a dry weight basis and the release agent is present in a range of from about 0.5. to about 10 percent by weight, on a dry weight basis, based on the weight of the solids content. The aqueous dispersion contains from about 10 to about 50 percent by weight solids.

By way of example, the thermoplastic polymer can have a glass transition temperature of at least about 40 degrees centigrade. As another example, the thermoplastic polymer can be an acrylate-vinyl chloride copolymer. As a further example, the powder plasticizer can be an aromatic carboxylic acid ester, such as cyclohexane dimethanol dibenzoate. As a further example, the average particle size of the powder plasticizer may not be greater than about 20 microns.

Detailed description of the invention As used herein, the term "sheet-type fibrous material" is intended to include any fibrous material which is typically prepared by placing by air or wetting relatively short fibers to form a sheet or non-woven fabric. Thus, the term includes non-woven fabrics prepared from a supply for making paper. Such a supply may include, by way of illustration, only cellulose fibers, a mixture of cellulosic fibers and non-cellulosic fibers, or only non-cellulosic fibers. When the supply contains only cellulosic fibers or a mixture of cellulosic fibers and non-cellulosic fibers, the resulting fabric is referred to herein as "cellulosic nonwoven fabric". Non-cellulosic fibers include, by way of illustration only, fibers and glass wool prepared from the thermosetting of thermoplastic polymers as is well known to those having ordinary skill in the art. Of course, the cellulosic nonwoven fabric may also contain additives and other materials, such as fillers, for example, clay and titanium dioxide, as well as is well known in the art of papermaking. Desirably, the fibrous sheet type material will be composed of synthetic thermoplastic fibers, examples of these materials being the Kimdura® synthetic papers manufactured by Oji-Yuka Paper Company of Japan. Such materials have desirably smooth surfaces and handle more like paper than films. In addition, such synthetic papers are readily available and are more docile and exhibit a reduced tendency to build up static that attracts dust. The powder on the coating causes print gaps since the dye diffusion tape printers require intimate contact between the substrate and the tape for a suitable dye transfer.

In general, the term "cellulosic fibers" is intended to include cellulosic fibers from any source. Sources of cellulosic fibers include, by way of illustration only, woods such as soft woods and hard woods, straws and grasses, such as rice, esparto grass, wheat, rye and sabai; bamboos, jute, flax, soft rush, hemp; linen; ramie abaca; henequen; and cotton and cotton lint. Softwoods and hardwoods are the most commonly used sources of cellulosic fibers. In addition, cellulosic fibers can be obtained by any processes commonly used for pulping, such as mechanical, chemistry, semi-chemical and chemical processes. For example, softwood and hardwood kraft pulps are desirable for their strength and tear resistance, but other pulps, such as recycled fibers, sulfite pulp and the like can be used, depending on the application.

The phrase "ratio by weight of the thermoplastic polymer to the plasticizer" refers to the parts by weight of thermoplastic polymer and plasticizer per 100 parts by weight of both components, separated :, such as 80:20 or 40:60. The weight ratio can also be expressed as a fraction, for example, 80/20 or 40/60. Thus, the ratio of 80:20 (or 80/20) is equivalent to four parts by weight of the thermoplastic polymer for each part by weight of plasticizer.

The term "thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade" is intended to include any thermoplastic polymer which meets the declared glass transition temperature requirement. Examples of such thermoplastic polymers include, by way of illustration only, poly (acrylonitrile); poly (methacrylonitrile); polyvinylchloride); poly (acrylic acid); poly (methacrylic acid); a poly (acrylate), such as poly (4-biphenyl acrylate), poly (2-t-butylphenyl acrylate), poly [3-chloro-2, 2-bis (chloro-methyl) propyl acrylate], poly (4-) chlorophenyl acrylate) poly (pentachlorophenyl acrylate), poly (2-ethoxycarbonylphenylacrylate), poly (2-heptyl acrylate), poly (hexadecyl acrylate) poly (3-methoxycarbonylphenyl acrylate), poly (4-methoxyphenyl acrylate), poly (3, 5-dimethylaminyl acrylate), poly (3-dimethylaminophenyl acrylate), poly (2-naphthyl acrylate), poly (phenylacrylate), poly (o-tolyl acrylate), poly (methyl methacrylate) poly (benzyl methacrylate), poly (2 - bromoethyl methacrylate), poly (2-t-butylaminoethyl methacrylate), poly (sec-butyl methacrylate) poly (t-butyl methacrylate), atactic and syndiotactic, poly (2-chloroethyl methacrylate), poly (cyclohexyl methacrylate), poly (t-butylcyclohexyl methacrylate) ), poly (ethyl methacrylate), syndiotactic atactic, poly (2-hydroxyethyl methacrylate), poly (isopropy methacrylate) atactic and syndiotactic, poly (ethyl chloroacrylate) o) and poly (ethyl fluoromethacrylate); a poly (acrylamide), such as poly (acrylamide), poly (N-butyl-acrylamide), poly (N-sec butylacrylamide), poly (Nt-butyl acrylamide), poly (NN-dibuty acrylamide), poly (isodecyl acrylamide) ), poly (isohexy acrylamide) poly (isononyl acrylamide), poly (isooctyl acrylamide), poly (N-isopropylacrylamide), poly (N, N-diisopropylacrylamide), poly (N, N-dimethylacrylamide), poly [N- (1-methylbutyl) acrylamide], poly (N-methyl-N-phenylacrylamide), poly (morphorylacrylamide), poly (N-octylacrylamide), and poly (4-ethoxycarbonylphenylmethacrylamide); or poly (styrene), such as poly (styrene), poly (4-acetylstyrene), poly (5-bromo-2-methoxystyrene), poly (4-butoxycarbonylstyrene), poly (3-chlorostyrene), poly (2-ethylstyrene) ), poly (4-methoxy styrene) and poly (3-methylstyrene); a poly (ester), such as poly (ethylene terephthalate) and poly (trimethylene terephthalate); a poly (substituted ethylene), such as poly (t-butylethylene), poly (cyclohexylethylene), atactic and isotactic, poly (2-cyclohexylether), poly i [(cyclohexyl Imetyl) ethylene], poly (cyclopentylethylene), poly [(cyclopentylmethyl) ethylene], poly (hexyldecylethylene), poly (isobutylethylene), atactic and isotactic poly (isopropyl-ethylene), poly (3, 3-dimethylbutylethylene), poly- (1,1,2-trimethyltrimethylene), poly (4, 4-dimethylpentylethylene), poly (neopentylethylene), poly (t-butoxyethylene), poly (cyclohexyloxyethylene), poly (2-methoxypropylene), poly (2-methoxypropylene), poly (benzoylidene), poly (1) , 2-difluoroethylene), poly (3-chlorobenzoyloxyethylene); in poly (phenylene), such as poly (2-methyl-1, 4-f-ethylethylene), and poly (2-chloro-1,4-f-methylene-ethylene); a . poly (oxide), such as poly (oxy-t-butylethylene), poly (oxy-1, 4-phenylene), and poly (oxyfethylethylene), - a poly (amide), such as poly (iminopentamethyleneiminoadipoyl) (or nylon 5, 6), poly (imino-1-oxo-hexamethylene) (onyl or 6), poly (iminoadipoyliminohexamethylene) or (nylon 6,6), and poly (iminohexamethyleneiminododecanedioyl) (or nylon 6,12).

As used herein, the term "acrylate" is intended to include any ester of acrylic acid or a substituted acrylic acid, such as methacrylic acid. For example, the acrylate can be one which is particularly suitable for use in the preparation of a copolymer in which one component is vinyl chloride. The term is also intended to include a single acrylate or two or more acrylates. In an analogous form, the term "poly (acrylic acid)" is intended to include polymers of acrylic acid or a substituted acrylic acid, such as methacrylic acid.

In accordance with the present invention, a coating suitable for receiving an image by dye diffusion printing is provided. The coating includes a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade. For example, the thermoplastic polymer may have a glass transition temperature of at least about 40 degrees centigrade. As another example, the thermoplastic polymer can be acrylate-vinyl chloride copolymer.

The coating may also include a powder plasticizer having a melting point of at least about 80 degrees centigrade. In general, the plasticizer can be any plasticizer which is appropriate for the thermoplastic polymer. By way of example, when the thermoplastic polymer is acrylate-vinyl chloride copolymer, the plasticizer can be an aromatic carboxylic acid ester. As a further example, the plasticizer can be a benzoate. As another example, the plasticizer can be cyclohexane dimethanol dibenzoate.

Desirably, the average particle size of the powder plasticizer will not be greater than about 20 microns. This allows the powder plasticizer to be easily dispersed in an aqueous medium, such as an aqueous dispersion of the thermoplastic polymer. For example, the average particle size of the powder plasticizer may not be greater than about 15 microns.

The weight ratio of the thermoplastic polymer to the plasticizer is typically in a range of from about 80:20 to about 60:40. For example, the weight ratio of the thermoplastic polymer to the plasticizer can be from about 70:30 to about 50:50.

Finally, the coating includes a release agent. The release agent may be present in a range of from about 0.5 to about 10 weight percent, based on the total weight of the coating.

The present invention further provides a coated substrate suitable for receiving an image by dye diffusion printing which includes a first flexible layer as described; a second layer covering the first surface of the first layer, which second layer comprises a first thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade and a first powder plasticizer having a melting point of at least around 80 degrees Celsius; and a third layer lying on the second layer, whose third layer includes a second thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, a second powder plasticizer having a melting point of less than about 80 degrees centigrade and a releasable agent.

The first layer has a basis weight of from about 50 to about 200 grams per square meter. For example, the first layer can be a movie. As an additional example the first layer can be a fibrous sheet type material. The second layer has a basis weight of about 0.5 to about 10 grams per square meter, the third layer has a basis weight of about 0.5 about 10 grams per square meter.

Weight ratio of the first thermoplastic polymer to the first plasticizer is in a range from about 80:20 to about 40:60 and the ratio by weight of the second thermoplastic polymer to the second plasticizer is in a range of from about 80:20 at around 40:60. The releasing agent is present in the third layer in a range d from about 0.5 to about 10 weight percent based on the weight of the third layer.

By way of illustration only, the thermoplastic prime polymer may have a glass transition temperature of at least about 40 degrees centigrade. For example, the first thermoplastic polymer may be an acrylate-vinyl chloride copolymer. Similarly, the second thermoplastic polymer can have a glass transition temperature of at least about 40 degrees centigrade and can be an acrylate-vinyl chloride copolymer. The first powder plasticizer can be an aromatic carboxylic acid ester, such as cyclohexane dimethane dibenzoate. The average particle size of the prime powder plasticizer can be, for example, not greater than about 20 microns. In a similar form, the second powder plasticizer can be an aromatic carboxylic acid ester such as cyclohexane dimethanol dibenzoate and can have an average particle size no greater than about 20 microns.

Finally, the present invention provides a coating composition which is an aqueous dispersion of a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, a powder plasticizer having a melting point of at least about 80 degrees Celsius, and a release agent. The weight ratio of the thermoplastic polymer to the powder plasticizer is in a range of from about 80:20 to about 40:60, on a dry weight basis, and the release agent is present in a range of from about 0.5 to about 10 weight percent, on a dry weight basis, based on the weight of the coating solids. The aqueous dispersion contains from about 10 to about 50 percent by weight solids.

By way of example, the thermoplastic polymer can have a glass transition temperature of at least about 40 degrees centigrade. As another example, the thermoplastic polymer can be an acrylate-vinyl chloride copolymer. As a further example, the powder plasticizer can be an aromatic carboxylic acid ester such as cyclohexane dimethanol dibenzoate. As a further example, the average particle size of the plasticizer and powder may not be more than about 20 microns.

The present invention is further described by the following Examples. Such examples however should not be considered as limiting any spirit or scope of the present invention.

E j e m p l o s The substrates used in the examples were Kimdura® FPG-150 synthetic paper from Oji-Yuka Peper Company, a 4-mil white opaque polyester film (class 339/380 from Imperial Chemical Industries of Great Britain), and another paper Synthetic, Kimdura® QBZ180. These are referred to hereinafter as substrates 1, 2 and 3, respectively (or S-1, S-2, and S-3).

Various different coating compositions were also used. These are identified below.

Coater Composition 1 (C-l) The coating composition was a 50/50 mixture on a dry weight basis of Vycar® 352 and Benzoflex® 352. Vycar® 352 is a total solids latex dispersion of 56 percent of an acrylate-vinyl chloride copolymer having a glass transition temperature of 69 degrees Celsius (BF Goodrich Company, Cleveland Ohio). Benzoflex® 352 is a cyclohexane dimethanol dibenzoate from Velsicol Chemical Corporation 0- The flake form of the material was milled at an average particle size of 10 microns. In this manner it is easily dispersed in water containing 3 parts on a dry weight basis of a Triton X-100 octylphenol polyethoxylated from Rohm and Haas Company of Philadelphia, PA) 100 parts of Benzoflex® 352; the resulting dispersion contained 33 percent solids.

Coater Composition 2 (C-2) Coating composition 2 was a mixture of 46. 5 / 46.5 / 7 on a dry weight basis of Vycar® 352, Benzoflex® 352, and Dow Coming 190 silicone, a release agent.

Coater Composition 3 (C-3) Coating composition 3 had a mixture of 62/31/7 on a dry weight basis of Vycar® 352, Benzoflex5 352, and Dow Corning 190 silicone.

Coater Composition 4 (C-4) This coating composition consists of Michem2 Prime 4983.

Coater Composition 5 (C-5) This coating composition was a mixture of 100/50/25/10/5 of Vycar® 352, of Kronitex® 100, of Michem® Prime 4983, of calcium stearate (Nopcote® C-104, Henkle Corporation, of Ambler PA) ), and Xama® 7. Kronitex® 100 is any liquid aryl phosphate plasticizer (FMC Corporation). Xama® 7 is a cross-linked multifunctional aziridine linker (Sancor Industries, Leomaster, MA).

A substrate was coated with one or more coatings, by means of a Meyer rod with drying between the coatings as necessary. The resulting materials are summarized in Table 1.

Table 1 Synthesis of Dye Diffusion Substrates read. Recub imi ento 2o. Coating 3 er. Coating Coating weight in grams per square meter. Not present .

Each substrate was printed with a multicolored test pattern with three or more color graduations in each color. The resulting patterns are cut into rectangles of approximately 3 inches by 2 inches (about 7.6 centimeters by about 5 centimeters) and are taped to the laser beakers from the RPL. The beaker press used was the RPL model. The transfer to the cups was carried out at about 135 degrees centigrade for three minutes, except for Example 7. The results of the printing and beaker transfer are summarized in Table 2.

Table 2 Bead Printing and Transfer Results The utility of a release agent in a single coating was demonstrated by Examples 1 and 2, even though the coating had not been optimized. Examples 3-5 showed the improved results which can be obtained with two coatings, in which the first coating did not contain a release agent. Three coatings may be employed, if desired, as shown by Example 6; The first coating in that Example was a priming which provides a better print quality. The problem caused by the accumulation of static charge with a film was illustrated by Example 7, even though the printing and the transfer of the printed image were otherwise good.

The excellent cubilet transfer results at only 135 degrees Celsius were amazing, as were the excellent dark good prints. The results seen with Example 8 were more typical of prior art materials. The transfer material used in that Example is generally not suitable for beaker transfers due to ink staining and poor transfer of the image to the beaker.

Also surprising was the ease of making water-based coatings using the fine powder plasticizer as described in the Examples. Liquid plasticizers gave problems to make stable coatings using the coatings made with it.

Even when the description has been made and detail with respect to the specific incorporations of the same, it will be appreciated by those skilled in the art, to achieve and understanding of the foregoing, that alterations, variations and equivalents of these additions can be conceived. Therefore, the scope of the present invention should be established as that of the appended claims and any equivalents thereof.

Claims

R E I V I N D I C A C I O N S

1. A coating suitable for receiving an image by dye diffusion printing comprising: a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade; a powder plasticizer having a melted point of at least about 80 degrees centigrade; Y a release agent; where : the weight ratio of the thermoplastic polymer to the powder plasticizer ranges from about 80:20 to about 40:60; Y the release agent is present in a range of from about 0.5 to about 10 percent by weight, based on the weight of the dried coating.

2. The coating as claimed in clause 1 characterized in that the thermoplastic polymer has a glass transition temperature of at least about 40 degrees centigrade.

3. The coating as claimed in clause 2, characterized in that the thermoplastic polymer is an acrylate-vinyl chloride copolymer.

4. The coating as claimed in clause 1 characterized in that the powder plasticizer is an aromatic carboxylic acid ester.

5. The coating as claimed in clause 4, characterized in that the powder plasticizer is cyclohexane dimethanol dibenzoate.

6. The coating as claimed in clause 1 characterized in that the average particle size of the powder plasticizer is not greater than about 20 microns.

7. A coated substrate suitable for receiving an image by dye diffusion printing comprising: a first flexible layer having the first and second surfaces and selected from the group consisting of films, fibrous sheet-like materials and combinations thereof; Y a second layer covering the first surface of the first layer, which second layer comprises a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, a powder plasticizer having a melting point of at least about 80 degrees Celsius, and a release agent; where : the first layer has a basis weight of from about 50 to about 200 grams per square meter; the second layer has a basis weight of from about 0.5 to about 10 grams per square meter; the proportion by weight of thermoplastic polymer to plasticizer is in a range of from about 80:20 to about 40:60; Y the release agent is present in a range of from about 0.5 to about 10 weight percent, based on the weight of the second layer.

8. The coated substrate as claimed in clause 7 characterized in that the thermoplastic polymer has a glass transition temperature of at least about 40 degrees centigrade.

9. The coated substrate as claimed in clause 8 characterized by the thermoplastic polymer is acrylate-vinyl chloride copolymer.

10. The coating as claimed in clause 7, characterized in that the powder plasticizer is an aromatic carboxylic acid ester.

11. The coating as claimed in clause 10 characterized in that the powder plasticizer is cyclohexane dimethanol dibenzoate.

12. The coated substrate as claimed in clause 7 characterized in that the average particle size of the powder plasticizer is not greater than about 20 microns.

13. The coated substrate as claimed in clause 7 characterized in that the first layer is a film.

14. The coated substrate as claimed in clause 7 characterized in that the first layer is a fibrous sheet type material.

15. A coated substrate suitable for receiving an image by dye diffusion printing comprising: a first flexible layer having the first and second surfaces and selected from the group consisting of films, fibrous sheet-like materials and combinations thereof; a second layer covering the first surface of the first layer, the second layer comprising a first thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, and a first powder plasticizer having a point of melted at least about 80 degrees Celsius; Y a third layer covering the second layer, which third layer comprises a second thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade, a second powder plasticizer having a melting point of less than about 80 degrees centigrade and a release agent; where : the first layer has a basis weight of from about 50 to about 200 grams per square meter; the second layer has a basis weight of from about 0.5 to about 10 grams per square meter; the third layer has a basis weight of from about 0.5 to about 10 grams per square meter; the weight ratio of the first thermoplastic polymer to the first powder plasticizer ranges from about 80:20 to about 40:60; the weight ratio of the second thermoplastic polymer to the second powder plasticizer ranges from about 80:20 to about 40:60; Y the release agent is present in the third layer in a range of from about 0.5 to about 10 weight percent, based on the weight of the third layer.

16. The coated substrate as claimed in clause 15 characterized in that the first thermoplastic polymer has a glass transition temperature of at least about 40 degrees centigrade.

17. The coated substrate "as claimed in clause 16, characterized in that the first thermoplastic polymer is an acrylate-vinyl chloride copolymer.

18. The coated substrate as claimed in clause 15 characterized in that the second thermoplastic polymer has a glass transition temperature of at least about 40 degrees centigrade.

19. The coated substrate as claimed in clause 18 characterized in that the second thermoplastic polymer is an acrylate-vinyl chloride copolymer.

20. The coating as claimed in clause 15 characterized in that the first powder plasticizer is an aromatic carboxylic acid ester.

21. The coating as claimed in clause 20 characterized in that the first powder plasticizer is cyclohexane dimethanol dibenzoate.

22. The coated substrate as claimed in clause 15 characterized in that the average particle size of the first powder plasticizer is not greater than about 20 microns.

23. The coating as claimed in clause 15 characterized in that the second powder plasticizer is an aromatic carboxylic acid ester.

24. The coating as claimed in clause 23 characterized in that the second powder plasticizer is cyclohexane dimethanol dibenzoate.

25. The coated substrate as claimed in clause 15 characterized in that the average particle size of the second powder plasticizer is not greater than about 20 microns.

26. The coated substrate as claimed in clause 15 characterized in that the first layer is a film.

27. The coated substrate as claimed in clause 15 characterized in that the first layer is a fibrous sheet type material.

28. A coating composition comprising an aqueous dispersion of: a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade; a powder plasticizer having a melting point of at least about 80 degrees centigrade; Y a release agent; where : the weight ratio of the thermoplastic polymer to the powder plasticizer ranges from about 80:20 to about 40:60; the release agent is present in a range of from about 0.5 to about 10 percent by weight, based on the weight of the dry coating composition; Y the aqueous dispersion contains from about 10 to about 50 percent by weight solids.

29. The coating composition as claimed in clause 28 characterized in that the thermoplastic polymer has a glass transition temperature of at least about 40 degrees centigrade.

30. The coating composition as claimed in clause 29 characterized in that the thermoplastic polymer is an acrylate-vinyl chloride copolymer.

31. The coating composition as claimed in clause 28 characterized in that the powder plasticizer is an aromatic carboxylic acid ester.

32. The coating composition as claimed in clause 31, characterized in that the powder plasticizer is a cyclohexane dimethanol dibenzoate.

33. The coating composition as claimed in clause 31 characterized in that the average particle size of the powder plasticizer is not greater than about 20 microns. U M N A coating suitable for receiving an image by dye diffusion printing which includes a thermoplastic polymer having a glass transition temperature of at least about 30 degrees centigrade and a powder plasticizer having a melting point of at least about 30 degrees Celsius. at least around 80 degrees Celsius. The thermoplastic polymer can have a glass transition temperature of at least about 40 degrees centigrade. For example, the thermoplastic polymer can be an acrylate-vinyl chloride copolymer. The plasticizer can be an aromatic carboxylic acid ester, such as a cyclohexane dimethanol dibenzoate. The average particle size of the powder plasticizer may not be greater than about 20 microns. The weight ratio of the thermoplastic polymer to the plasticizer is typically in a range of from about 80:20 to about 40:60. Finally, the coating includes a releasing agent. The releasing agent may be present in a range of from about 0.5 to about 10 weight percent, based on the weight of the dry coating. The present invention also provides a coated substrate suitable for receiving an image by dye diffusion printing and a coating composition which is an aqueous dispersion of a thermoplastic polymer having a glass transition temperature of at least about 30 degrees. centigrade a powder plasticizer having a melting point of at least about 80 degrees centigrade and a release agent.