Transfer paper for sublimation printing, production method thereof and method for decorating printing stock

Abstract

The invention relates to transfer paper for sublimation printing, a production method thereof and a method for decorating a printing stock. The present invention provides a transfer paper for sublimation printing having one or more alkaline earth metal salts and an organic cationic agent on at least one side wherein the side is free of other formulation or the amount of other formulation is less than 13 times the amount of the cationic agent, wherein other formula components comprise a binder, a pigment, a dispersing agent, a wetting agent, a thickening agent, an insoluble reagent, an adhesive, a brightener or a coloring agent. The invention also provides a method for producing the transfer paper, a method for printing the transfer paper and the printed transfer paper. Further, the invention provides a method for decorating a substrate.

Description

[0001] This application is a divisional application of the invention patent application filed on January 10, 2018, entitled "Transfer Paper for Sublimation Printing Containing Alkaline Earth Metal Salts" with application number 2018800066560. Technical Field

[0002] This invention relates to transfer paper for sublimation printing, and more particularly to, but not limited to, transfer paper for inkjet printing. Background Technology

[0003] Sublimation printing uses sublimable inks to create images on substrates such as metal, glass, plastic surfaces, or fabrics. Sublimation ink printing can be performed either by printing the sublimable ink directly onto the final substrate or by indirect printing. In the case of indirect printing, the ink is first printed onto paper, called transfer paper, and then the image printed on the transfer paper is transferred to the final substrate by pressing. Application US 2008 / 0229962 describes this printing process.

[0004] Applications EP 2965919 A1, WO00 / 06392, WO2008 / 006434 and WO2016 / 074671 disclose transfer paper for sublimation printing.

[0005] Specifically, application EP 2965919 A1 discloses a transfer paper comprising a reservoir having an outer surface configured to receive sublimable ink, and a barrier layer applied to an inner surface of the reservoir and configured to form a barrier for the transport of the sublimable ink. The reservoir may also contain a small portion of a cationic polymer to fix the sublimable ink pigment to the surface of the transfer paper.

[0006] Application WO00 / 06392 describes a transfer paper containing a barrier layer, wherein the porosity is a maximum of 100 ml / min.

[0007] Application WO2008 / 006434 discloses paper comprising a layer having a semi-synthetic thermoplastic polymer.

[0008] Application WO2016 / 074671 describes paper containing layers with thermoplastic particles.

[0009] Sublimation transfer paper, which can be printed by inkjet printing, typically contains a barrier layer based on a hydrophilic polymer (such as carboxymethyl cellulose, starch, or polyvinyl alcohol) and is more or less filled with low surface area pigments, such as kaolin or calcium carbonate, or high surface area pigments, such as silica.

[0010] The presence of a barrier layer based on hydrophilic polymers results in a long drying time, which limits the printing rate and causes color mixing and bleeding, affecting print quality.

[0011] Introducing fillers can mitigate the aforementioned drawbacks, but it comes at the cost of increased formulation costs and / or limitations on sublimation transfer rates.

[0012] Therefore, there remains an unmet need for a sublimation printing transfer paper that can be printed by inkjet printing, possessing good printability and limited drying time, high transfer rate and low paper weight, particularly equal to or less than 50 g / m². 2 . Summary of the Invention

[0013] The present invention aims to meet this need by using a sublimation printing transfer paper having one or more alkaline earth metal salts on at least one side.

[0014] The transfer paper according to the invention has good printability, especially due to one or more alkaline earth metal salts fixing the ink to the surface.

[0015] Fixing ink pigments to the surface using one or more alkaline earth metal salts improves the optical density after transfer and limits bleeding. This improves the limitation.

[0016] One or more alkaline earth metal salts can be used at a concentration equal to or greater than 0.2 g / m 2 Especially equal to or greater than 0.5 g / m 2 The amount of it exists on the side of the paper.

[0017] Transfer paper may contain a fibrous substrate on which one or more alkaline earth metal salts are deposited through surface treatment, particularly a single layer in a multilayer.

[0018] One or more alkaline earth metal salts may be present on one side of the transfer paper used to receive the print.

[0019] One or more alkaline earth metal salts are preferably selected from calcium salts or magnesium salts or mixtures thereof.

[0020] Alkaline earth metal salts can be calcium chloride or calcium nitrate.

[0021] Alkaline earth metal salts can be magnesium sulfate or magnesium chloride.

[0022] The side of the transfer paper containing one or more alkaline earth metal salts may also contain one or more organic cationic reagents, particularly selected from epichlorohydrin polyamines, especially polyephichlorohydrin dimethylamine, polyethyleneimine, and organic quaternary ammonium salts, preferably organic quaternary ammonium salts. The cationic reagent is, in particular, polydiallyldimethylammonium chloride, also known as PolyDadmac. The latter can improve the transfer.

[0023] On the side containing alkaline earth metal salts, the transfer paper may be free of other formulation components such as binders, pigments, dispersants, wetting agents, thickeners, insoluble reagents, adhesives, gloss agents, or colorants; or the transfer paper may contain other formulation components on this side, such as binders, pigments, dispersants, wetting agents, thickeners, insoluble reagents, adhesives, gloss agents, or colorants, in g / m 2 The total amount, individually or preferably, is equal to or less than 13 times the amount of one or more cationic reagents, for example, equal to or less than 12 times, or 10 times, or 8 times or 5 times.

[0024] The absence or minimal presence of these components allows for an optimal trade-off between ink fixation (color fixing) and ink drying.

[0025] The transfer paper may have at least one side containing one or more alkaline earth metal salts without the other formulation components described above, or may contain other formulation components on this side, the total amount of which, individually or preferably, is equal to or less than 10 g / m². 2 .

[0026] When the transfer paper contains mineral fillers, these may be selected from calcium carbonate, kaolin, calcined kaolin, talc, TiO2, hydroxides, especially aluminum Al(OH)3 or magnesium hydroxides, sulfates, especially BaSO4 or CaSO4, natural or synthetic aluminum silicate, alumina, or mixtures thereof.

[0027] Mineral fillers block surface inks. The presence of one or more alkaline earth metal salts according to the invention eliminates the need for mineral fillers, or at least limits their quantity.

[0028] The transfer paper may have no binder on at least the side containing one or more alkaline earth metal salts, or may contain one or more binders on that side in an amount equal to or less than 8 g / m². 2 .

[0029] One or more binders may be selected from water-soluble binders, such as polyvinyl alcohol, starch, gelatin, soy or casein, or mixtures thereof.

[0030] Transfer paper is preferably printed using inkjet printing.

[0031] Transfer paper can also be printed using a rotary press.

[0032] The transfer paper preferably has a Bendtsen air permeability of 100 ml / min or more, particularly 200 ml / min or more (according to standard ISO 5636-3).

[0033] This air permeability gives the paper an open structure. This ensures that the ink applied to the transfer paper dries quickly. Therefore, by increasing the ink drying rate, the yield is increased compared to lower air permeability.

[0034] The transfer paper preferably has a paper weight of 25 to 150 g / m³. 2 Between 30 and 75 g / m 2 Between, or better equal to or less than 50 g / m 2 .

[0035] Transfer paper is typically used only once.

[0036] The present invention also relates to a method for preparing transfer paper for sublimation printing, particularly as described above, wherein a surface treatment is used to deposit one or more alkaline earth metal salts, or one or more compounds, on at least one side of a fiber substrate, wherein the one or more compounds are formed in situ in the presence of one or more other compounds carried by the fiber substrate.

[0037] Surface treatment can be a single layer or multiple layers.

[0038] The method according to the present invention may include the production of a fiber substrate.

[0039] Surface treatment can be performed online or offline.

[0040] One or more alkaline earth metal salts can be deposited or formed on one side of a fibrous substrate.

[0041] The fiber substrate may contain natural and / or synthetic fibers, especially long and short cellulose fibers.

[0042] A composition comprising one or more alkaline earth metal salts can be deposited on the side of a fiber substrate by surface treatment, and the amount of the composition deposited on the fiber substrate can be between 0.2 and 15 g / m³ on a dry weight basis. 2 Between 0.5 and 8 g / m 2 between.

[0043] Surface treatment can be performed using a sizing press, film transfer press, or coating system, particularly curtain coating, doctor blade coating, air knife coating, crayon coating, or by engraving rollers.

[0044] The fiber substrate before treatment may contain one or more compounds for forming one or more alkaline earth metal salts during the production of transfer paper.

[0045] One or more alkaline earth metal salts can be formed during the production of transfer paper by reacting compounds deposited on the fiber substrate by surface treatment with other compounds introduced in batches during the production of the fiber substrate.

[0046] For example, one or more alkaline earth metal salts can be formed during the production of transfer paper through an acid-base reaction of calcium carbonate, which is introduced in batches during the production of the fiber substrate by coating through an acidic glue press.

[0047] The present invention also relates to printed sublimation printing transfer paper, comprising the transfer paper as defined above and at least one print on the side of the transfer paper containing one or more alkaline earth metal salts, particularly inkjet printing with at least one sublimable ink.

[0048] The present invention also relates to a printing method for transfer paper for sublimation printing, wherein at least one ink is used, particularly by inkjet printing, to print on the side of the previously defined transfer paper containing one or more alkaline earth metal salts.

[0049] As a variation, printing can be performed using a rotary press.

[0050] For example, printing can be four-color printing, where the ink cartridges contain primary color inks, specifically black, cyan, yellow, and magenta, and may also contain synthetic colors (mixed colors). The inks are formulated with water-based sublimable pigments.

[0051] The present invention also relates to a method for decorating a substrate, wherein a print on a transfer paper as described above is transferred to the substrate.

[0052] The substrate can be metal, glass, plastic surface or fabric, especially fabric containing polyester, preferably fabric mainly containing polyester. Detailed Implementation

[0053] Examples 1 to 6 The compositions described in the table below are each deposited on one side of a fibrous substrate having the composition and properties described below using a Mayer rod. The fibrous substrate is then treated with these compositions for transfer paper.

[0054] Base paper before coating Fiber composition: 30% cork + 70% mixed short fibers Basis weight = 60 g / m 2 Cobb value 60s = 15 g / m 2 Bentson porosity = 1500 ml / min Coating rules: Based on the composition and coating in the table below. Printing tests were conducted on paper using a SAWGRASS SG400 printing press, and the transfer was performed by pressing on polyester fabric at 200°C for one minute.

[0055] Black ink (SAWGRASS Sublijet Black) is deposited on one side of the fiber substrate treated with the composition. This results in a pure black area. The transfer paper treated with the ink forms printed transfer paper.

[0056] The optical density after transfer to polyester fabric was measured using an X-rite 500 spectrometer.

[0057] The proportion is expressed as dry weight.

[0058] The amounts of calcium carbonate, aluminum silicate, polyvinyl alcohol, sorbitol, PolyDADMAC, and alkaline earth metal salts are expressed as percentages on a dry weight basis (% dry weight).

[0059]

[0060] The printed transfer paper described in Examples 1, 2, 3, 4 and 5 is paper according to the invention, which has a higher optical density than the printed transfer paper according to Example 6 which is not according to the invention.

[0061] Examples A, B and C In Examples 1, 2, and 3, the black ink was replaced in Examples A, B, and C with the color of the pure red areas formed by printing yellow and magenta (SAWGRASS Sublijet). The results are shown in the table below.

[0062]

[0063] Calcium chloride has excellent optical density and a pure red color.

Claims

1. A transfer paper for sublimation printing, having one or more alkaline earth metal salts and an organic cationic reagent on at least one side, wherein the side has no other formulation components or the amount of such other formulation components is less than 13 times the amount of the cationic reagent, wherein the other formulation components are binders, pigments, dispersants, wetting agents, thickeners, insoluble reagents, adhesives, gloss agents, or colorants.

2. The transfer paper according to claim 1, wherein, The alkaline earth metal salt has a concentration equal to or greater than 0.2 g / m 2 The amount exists on at least one side.

3. The transfer paper according to claim 1 or 2, wherein, The at least one side containing the alkaline earth metal salt and the organic cationic reagent has no other surface treatment formulation components.

4. The transfer paper according to claim 1 or 2, wherein, The transfer paper can be printed using inkjet printing.

5. The transfer paper according to claim 1, wherein, The alkaline earth metal salt is calcium chloride or calcium nitrate.

6. The transfer paper according to claim 1, wherein, The alkaline earth metal salt is magnesium sulfate or magnesium chloride.

7. The transfer paper according to claim 1 or 2, having a Bentson air permeability equal to or greater than 100 ml / min according to standard ISO 5636-3.

8. The transfer paper according to claim 1 or 2, having a paper weight of 25 and 150 g / m³. 2 between.

9. A method for producing transfer paper according to any one of claims 1 to 8, comprising depositing on at least one side of a fiber substrate a composition comprising one or more alkaline earth metal salts or one or more compounds, wherein the one or more compounds are formed in situ in the presence of one or more other compounds carried by the fiber substrate.

10. The method according to claim 9, wherein, The fiber substrate is manufactured and the surface treatment is applied online or offline.

11. The method according to claim 9 or 10, wherein, The amount of the composition deposited on the side of the fiber substrate is between 0.2 and 15 g / m² on a dry weight basis. 2 between.

12. The method according to claim 9 or 10, wherein, The composition is applied using a sizing press, film transfer press, or coating system, or by means of a sculpting roller.

13. A printed transfer paper comprising the transfer paper according to any one of claims 1 to 8, and at least one print on the at least one side of the transfer paper having the alkaline earth metal salt.

14. A method comprising printing a sublimable ink on at least one side of a transfer paper containing the alkaline earth metal salt according to any one of claims 1 to 8.

15. The method according to claim 14, wherein, The printing is performed using inkjet printing.

16. A method for decorating a printing substrate, comprising: A transfer paper is provided according to any one of claims 1 to 8, wherein a sublimable ink is printed on at least one side of the transfer paper having the alkaline earth metal salt, and the printed ink is transferred to the substrate by sublimation.

17. A method for producing a fiber substrate, comprising introducing calcium carbonate in batches via coating through an acidic adhesive press, wherein one or more alkaline earth metal salts are formed during the production of transfer paper by an acid-base reaction of a compound deposited on the fiber substrate by a surface treatment with the calcium carbonate.

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