CN100519168C - Thermal transfer image receiving sheet and method - Google Patents

Abstract

A thermal transfer image-receiving sheet (1) capable of recording thereon thermally transferred dye or ink images in a clear and sharp form. The image-receiving layer (3) comprises at least one water dispersible aliphatic polyether-polyurethane resin and at least one water dispersible aliphatic polyester-polyurethane resin or a silica dispersion or an anionic aqueous emulsion of wax.

Description

Thermal transfer image receiving plate and method

Background of the invention

1. cross-reference to related applications

The application requires provisional patent application 60/454, No. 258 proposed on March 13, 2003, and the priority of provisional patent application 60/454, No. 960 proposed on March 14, 2003, and its disclosure is hereby incorporated in its entirety Enter as a reference.

2. field of invention

[0004] The present invention relates to thermal transfer image-receiving sheets. More particularly, the present invention relates to thermally transferred image receiving polymeric sheets capable of recording thereon thermally transferred dye or ink images in a clear and accurate form.

3. the discussion of related field

[0006] In a thermal transfer recording system, an ink ribbon is heated by a heating head or a laser or the like according to image information. The heating causes thermal melting, thermal diffusion, or thermal sublimation, by which the dye is transferred from the ink ribbon to the printing plate, where an image is formed.

[0007] Printing sheets are usually made of a support film coated with a dye receiving layer. The dye-receiving layer is a layer that receives dye or ink transferred to the layer by heating from an ink ribbon, and holds an image formed by the dye. Typical dye-receiving layers for polymeric substrates include at least one dye-receptive resin dissolved in an organic solvent. Examples of such solvent borne resins include polyesters, polycarbonates, polyvinyl chlorides, vinyl chloride copolymers such as vinyl chloride-vinyl acetate copolymers, and thermoplastic resins such as polyurethane resins, poly Styrene, acrylic-styrene (AS) resin, acrylonitrile-butadiene-styrene (ABS) resin, and the like.

[0008] It is desirable to reduce or eliminate the use of volatile organic solvents during the manufacture of polymeric image receiving sheets. In particular, there is a need to apply aqueous compositions for producing image receiving layers on polyester substrates without compromising image clarity and durability.

Summary of the invention

[0009] According to one aspect of the present invention, there is provided a printing plate of the type for use in a thermal transfer recording system. The printing sheet includes a polymeric film support, and an image receiving layer formed on the film support. The image receiving layer can be made from an aqueous coating composition. In one embodiment, the aqueous coating composition may include an aqueous dispersion of aliphatic polyester-polyurethane, and an aqueous dispersion of aliphatic polyether-polyurethane. In one embodiment, the aqueous coating composition may include an aqueous dispersion of an aliphatic polyether-polyurethane resin, a silicon dispersion, and an anionic aqueous emulsion of a wax. A water crosslinking agent can be added to the aqueous coating composition before drying the aqueous coating composition.

[0010] According to another aspect of the present invention, there is provided a dye receiving coating composition. In one embodiment, the dye-receiving coating composition may include an aqueous dispersion of aliphatic polyester-polyurethane, and an aqueous dispersion of aliphatic polyether-polyurethane. In one embodiment, the dye-receiving coating composition may include an aqueous dispersion of an aliphatic polyether-polyurethane resin, a silicon dispersion, and an anionic aqueous emulsion of a wax. A water crosslinking agent can be added to the dye receiving coating composition.

[0011] According to yet another aspect of the present invention, a method of preparing a thermal transfer image receiving plate is provided. The method is provided for coating the surface of a substrate panel with an aqueous coating composition. and, drying the aqueous coating composition to form a thermal transfer image receiving sheet.

Brief description of the drawings

In accompanying drawing:

[0013] FIG. 1 is a schematic diagram illustrating a cross-sectional view of a thermal transfer image receiving plate according to the present invention.

Detailed description of the invention

[0014] In the following specification, the invention is described with reference to FIG. 1 . 1 is a schematic cross-sectional view of an embodiment of a thermal transfer image receiving sheet 1 according to the present invention. The thermal transfer image receiving sheet 1 may include a substrate sheet 2 (substrate sheet 2) and a dye receiving layer 3 (dye receiving layer 3), and the dye receiving layer 3 is deposited on one surface of the substrate sheet 2.

[0015] With regard to the base plate 2, the base plate 2 may be made of sheet material, which is selected with reference to the specific criteria of the application. Such criteria include, for example, desired volume (height, length, and thickness), surface texture, composition, flexibility, and other physical and economic attributes or characteristics. Suitable board materials may include, for example, synthetic papers such as polyolefins, polystyrenes; wood free papers; art papers; coat papers ; polish coated paper (cast coat paper); wallpaper (wall paper); lining paper (lining paper); Vinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, and polycarbonate.

[0016] In one embodiment, the substrate sheet 2 can be, or can include, a multilayer polymeric sheet. The multiple layers may be coextruded together, or the multiple layers may be laminated together. In one embodiment, the substrate sheet 2 includes both coextruded and laminated layers.

[0017] Furthermore, by adding a white pigment, or a similar filler, to one or more of the aforementioned synthetic resins, a white opaque film is formed, and can be used as the substrate plate 2. In one embodiment, a foam film is used as the substrate sheet 2 . Foam films can be formed by conventional foaming operations. In one embodiment, the substrate board 2 may be a laminated body formed by compounding a plurality of the aforementioned single-layer boards composed of the materials listed above. Examples of such laminates include composite cellulose fiber paper laminates compounded with synthetic paper, and composite cellulose fiber paper laminates compounded with plastic films or plastic plates.

[0018] The thickness of the substrate plate 2 formed in the manner mentioned above can be determined with reference to the specific standards of the application. This standard can include the desired end use. In one embodiment, the plate thickness ranges from about 10 microns or micrometers (μm) to about 300 μm. In one embodiment, the plate thickness ranges from about 10 micronmeters or microns (μm) to about 150 μm. In one embodiment, the plate thickness ranges from about 150 micronmeters or microns (μm) to about 300 μm.

Can apply primer treatment or corona discharge treatment on base plate 2, to increase the binding force between base plate 2 and dye receiving layer 3, dye receiving layer 3 will be on a surface of base plate 2 Formed on.

[0020] An intermediate layer (not shown) may be provided between the dye receiving layer and the substrate sheet 2 to impart preselected properties. Such properties may include adhesion properties, whiteness or brightness, cushioning properties, antistatic properties, barrier properties, anti-curling properties, and the like.

[0021] A rear surface layer (not shown) may be provided on the surface of the base plate 2 opposite to the surface on which the dye-receiving layer 3 is formed. The rear surface layer can impart preselected properties to the thermal transfer image receiving sheet 1 . Properties include, for example, enhanced shipping suitability, enhanced writing properties, anti-staining, anti-curling properties, and the like. An antistatic layer (not shown) containing a commercially available antistatic substance may be provided on the dye-receiving layer 2 or on the rear surface layer for improving the antistatic property of the thermal transfer image receiving sheet 1, if desired.

[0022] The dye-receiving layer 2 may be a coating formed of an aqueous composition. In one embodiment, the aqueous coating composition includes at least one water-dispersible aliphatic polyether-polyurethane resin and at least one water-dispersible aliphatic polyester-polyurethane resin. The polyether-polyurethane resin and the polyester-polyurethane resin may be combined in the coating composition as separate aqueous dispersions. The dispersion will typically comprise colloidally dispersed particles of polyurethane polymer. In one embodiment, the weight ratio of polyether-polyurethane resin to polyester-polyurethane resin in the dye-receiving coating composition ranges from about 1:1 to about 2:1 , or range from about 2:1 to about 3:1, based on resin solids calculations for polyether-polyurethane and polyester-polyurethane.

[0023] In one embodiment, an aqueous coating composition includes an aqueous dispersion of an aliphatic polyether-polyurethane resin, a silicon dispersion, and an anionic aqueous emulsion of a wax.

[0024] In one embodiment, the polyester-polyurethane polymer is the reaction product of a primary aliphatic polyisocyanate component and a polyester polyol component. As used herein, the term "predominantly aliphatic" means that at least 70% by weight of the polyisocyanate component is an aliphatic polyisocyanate in which all isocyanate groups are directly bonded to aliphatic or cycloaliphatic groups , whether or not aromatic groups are also present. More preferably, the amount of aliphatic polyisocyanate is at least 85% by weight of the polyisocyanate component, and most preferably, is 100% by weight of the polyisocyanate component. Examples of suitable aliphatic polyisocyanates include: ethylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, 4,4'- Dicyclohexylmethane diisocyanate, cyclopentylene diisocyanate, p-tetramethylxylene diisocyanate (p-TMXDI) and its meta-isomer (m-TMXDI), hydrogenated 2,4-toluene diisocyanate, and 1-isocyanato-1-methyl-3(4)-isocyanatomethylcyclohexane (IMCI). Mixtures of aliphatic polyisocyanates can be used.

The polyester polyols that can be used in the polyester polyol composition include, the hydroxyl-terminated reaction products of polyhydric alcohols, such as ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, 1, 4-butanediol, 1,6-hexanediol, furandimethanol, cyclohexanedimethanol, glycerol, trimethylpropane or pentaerythritol, or mixtures thereof. Also included are polycarboxylic acids, especially dicarboxylic acids, and ester-forming derivatives thereof. Examples include, succinic acid, glutaric acid and adipic acid or their methyl esters, phthalic anhydride and dimethyl terephthalate. Polyesters obtained by polymerizing lactones, such as caprolactone, with polyols are also used. Commercially available polyester-polyurethanes useful in the present invention include those trade names of AVALURE UR-425, AVALURE UR-430, AVALURE UR-405 and AVALURE UR-410 available from Goodrich Corporation (Charlotte, NC); and NEOREZ R-989, sold by NeoResins (Waalwijk, The Netherlands).

[0026] In one embodiment, the polyether-polyurethane polymer is the reaction product of a predominantly aliphatic polyisocyanates component and a polyether polyol component. Useful aliphatic polyisocyanates are described above. Suitable polyether polyols include those obtained by polymerization of epoxides, or by adding one or more such oxides to a multifunctional initiator. Such polymeric epoxides include, for example, ethylene oxide, propylene oxide and tetrahydrofuran. Such multifunctional initiators with added oxides include, for example, water, ethylene glycol, propylene glycol, diethylene glycol, cyclohexanedimethanol, glycerol, trimethylpropane, pentaerythritol, and bisphenols (Bisphenols ) (such as A and F).

[0027] Suitable polyesters include polyoxypropylene diols and triols, poly(oxyethylene-oxypropylene) diols and triols, obtained by adding ethylene and propylene oxide simultaneously or sequentially to a suitable starter; and including Polytetramethylene glycol ether, obtained by the polymerization of tetrahydrofuran. Commercially available polyether-polyurethanes useful in the present invention include those sold by Goodrich Corporation (Charlotte, NC) under the trade names SANCURE 878, AVALURE UR-450 and SANCURE 861; Substance sold under the trade name NEOREZ R-551 by NeoResins (Waalwijk, The Netherlands).

[0028] The dye-receiving layer 3 may include a water dispersible crosslinker. Suitable water-dispersible multifunctional chemically activatable crosslinking formulations are commercially available. These crosslinking formulations include dispersible formulations of multifunctional aziridines, isocyanates, melamine formaldehyde resins, epoxy resins, oxazolines, carbodiimides, and other multifunctional crosslinking agents. In one embodiment, the crosslinking agent is added in an amount ranging from about 0.1 part to about 10 parts based on 100 parts total solids. In one embodiment, the crosslinking agent is added in an amount ranging from about 0.2 parts to about 5 parts based on 100 parts total solids. Addition of a crosslinking agent to a polyesterimine dispersion composition can form an interspersed or interconnected network having a crosslinked matrix covalently and/or non-covalently bonded to the mixed polymers.

[0029] The dye-receiving layer 3 to be formed as described above may have a predetermined thickness depending on factors such as viscosity, type of application, amount and method, desired end use and the like. In one embodiment, the thickness may range from about 1 μm to about 50 μm. In one embodiment, the thickness may range from about 1 μm to about 25 μm, and in one embodiment, the thickness may range from about 25 μm to about 50 μm.

[0030] The image receiving sheet 1 may be used in applications where thermal transfer printing is performed. Suitable uses include heat transfer plates in flat or roll form, cards and plates for the preparation of transparent artwork. The choice of parameters defining the substrate sheet 2 can assist in adapting the image-receiving layer 1 to the desired application.

Example

[0031] The following examples are intended only to illustrate methods and embodiments in accordance with the present invention and, therefore, should not be construed as limiting the claims. Unless otherwise indicated, all ingredients are commercially available from such common chemical suppliers as Sigma Aldrich, Inc. (St. Louis, MO) and/or Fisher Scientific International, Inc. (Hanover Park, IL) owned.

Embodiment 1-

[0033] Coating compositions containing the ingredients listed in Table 1 were prepared as follows. At the same time, an equal weight mixture of water and polyurethane dispersion was added, ie, 100 parts water to 100 parts dispersion.

[0034] The coating composition was then applied to a network of semi-clear, biaxially oriented polyethylene terephthalate (PET) substrates. The thickness of the network may be about 25 microns. The coating was dried at 90 degrees Celsius and a line speed of 120 meters per minute to form an image receiving layer. The dry coat weight of the image receiving layer ranges from about 0.8 g/m ² to about 1 g/m ² .

[0035] The coating composition of Example 1 was also coated on a 50 micron thick rough chrome, biaxially oriented PET substrate, and on a 50 micron thick white, biaxially oriented PET substrate of.

The composition list of table 1-embodiment 1

Element weight percent Polyurethane Dispersion (NEOREZ R-551: Aliphatic Polyester Urethane Dispersion, 35.5% Solids) 70 Polyurethane Dispersion (NEOREZ R-989: Aliphatic Polyester Urethane Dispersion, 40% Solids) 29.9 Cross-linking agent (cross-linking agent CX-100: multifunctional aziridine cross-linking agent) 0.1

Embodiment 2

[0038] Coating compositions containing the ingredients listed in Table 2 were prepared as follows. The ingredients were mixed until substantially homogeneous, and in substantially the same manner as in Example 1, the ingredients were coated on the substrate. The coated PET substrate network is suitable for laser printing with UV curable inks.

The composition list of table 2-embodiment 2

Element weight percent Polyurethane Dispersion 48.4

(NEOREZ R-563: Aliphatic Polyester Urethane Dispersion, 35.5% Solids) Silicon Dispersion (Polymer Product - FP44) 0.5 Anionic water emulsion of complex wax (AQUACER 537: aminoethanol) 1.0 Cross-linking agent (cross-linking agent CX-100: multifunctional aziridine cross-linking agent) 0.1 water 50.0

[0040] AQUACER 537, commercially available from Byk-Cera, is 2-diethylaminoethanol. Byk-Cera is a subsidiary of Byk-Chemie, a division of ALTANA AG (Bad Homburg, Germany).

[0041] While the invention has been explained in connection with the embodiments thereof, it is to be understood that various modifications of the invention will be apparent to those skilled in the art upon reading the specification. Accordingly, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims and insubstantial variations thereof.

Claims (20)

1. thermal transfer image receiving sheet comprises:

Backing material plate supports image and receives resin bed, is used to receive the image of transfer, and wherein image receiving layer is formed by dry aqueous coating compositions,

Aqueous coating compositions, comprise (1) (a) at least a water dispersible aliphatic polyether-polyurethane resin and at least a water dispersible aliphatic polyester-polyurethane resin, perhaps the anionic aqueous emulsion of (b) at least a water dispersible aliphatic polyether-polyurethane resin, silicon dispersion and wax; (2) water crosslinking agent.

2. the described thermal transfer image receiving sheet of claim 1, wherein said backing material plate comprises polyester.

3. the described thermal transfer image receiving sheet of claim 2, wherein said backing material plate comprise poly-terephthalic acids second diester.

4. the described thermal transfer image receiving sheet of claim 1, wherein said polyethers-polyurethane resin comprises the product of aliphatic polymeric isocyanate composition and polyether polyol composition.

5. the described thermal transfer image receiving sheet of claim 1, wherein said polyester-polyurethane carbamate resin comprises the product of aliphatic polymeric isocyanate composition and polyester polyol composition.

6. the described thermal transfer image receiving sheet of claim 1, the thickness that wherein said image receives resin bed is to 50 micrometer ranges from 1 micron.

7. dyestuff receives coating composition, comprising:

(a) at least a water dispersible aliphatic polyether-polyurethane resin; With

(b) at least a water dispersible aliphatic polyester-polyurethane resin.

8. the described dyestuff of claim 7 receives coating composition, further comprises polyfunctional crosslinking agent.

9. the described dyestuff of claim 8 receives coating composition, and wherein said polyfunctional crosslinking agent comprises multi-functional aziridine.

10. the described dyestuff of claim 7 receives coating composition, and wherein said coating composition is not contain organic solvent.

11. the described dyestuff of claim 7 receives coating composition, wherein, based on (a) and the calculating of resin solid (b), resin (a) than the weight ratio scope of resin (b) be 1: 1 to 3:1.

12. the described dyestuff of claim 7 receives coating composition, wherein said aliphatic polyether-polyurethane resin (a) comprises the product of aliphatic polymeric isocyanate composition and polyether polyol composition.

13. the described dyestuff of claim 7 receives coating composition, wherein said aliphatic polyester-polyurethane resin (b) comprises the product of aliphatic polymeric isocyanate composition and polyester polyol composition.

14. dyestuff receives coating composition, comprising:

The aqueous dispersion of at least a water dispersible aliphatic polyether-polyurethane resin;

The silicon dispersion; With

The anionic aqueous emulsion of wax.

15. the described dyestuff of claim 14 receives coating composition, further comprises polyfunctional crosslinking agent.

16. the described dyestuff of claim 15 receives coating composition, wherein said polyfunctional crosslinking agent comprises multi-functional aziridine.

17. the described dyestuff of claim 15 receives coating composition, wherein said coating composition is not contain organic solvent.

18. the described dyestuff of claim 14 receives coating composition, the anionic aqueous emulsion of wherein said wax comprises 2-diethylaminoethanol.

19. the described dyestuff of claim 14 receives coating composition, wherein said aliphatic polyether-polyurethanes comprises the product of aliphatic polymeric isocyanate composition and PPG composition.

20. a method that forms thermal transfer image receiving sheet comprises:

With aqueous coating compositions coated substrate plate surface, described aqueous coating compositions comprises

(a) at least a water dispersible aliphatic polyether-polyurethane resin, at least a water dispersible aliphatic polyester-polyurethane resin and water crosslinking agent; Perhaps

(b) anionic aqueous emulsion of the aqueous dispersion of at least a water dispersible aliphatic polyether-polyurethane resin, silicon dispersion, wax and water crosslinking agent; With

Dry aqueous coating compositions, thereby and formation thermal transfer image receiving sheet.

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