Coating slurry for low-residue heat sublimation transfer paper as well as preparation method and application of coating slurry

Abstract

The invention relates to coating slurry for low-residual heat sublimation transfer paper and a preparation method of the coating slurry. The coating slurry for the low-residual heat sublimation transfer paper is prepared by taking acrylic latex, an ink absorption material, calcium carbonate, silicon dioxide, modified acrylic resin and styrene-butadiene emulsion as raw materials. The modified acrylic resin is a product obtained by polymerizing 1, 3, 5-benzene triacrylic acid, hydrophilic acrylate and long alkyl chain acrylate and neutralizing with alkali. The modified acrylic resin disclosed by the invention has a three-dimensional network structure, so that permeation and residue of printing ink on raw paper are prevented, and adverse effects of printing ink permeation on a transfer printing effect are avoided; moreover, the introduced acrylate group is a flexible organic matter, so that the modified acrylic resin has good flexibility, the hardness of a transfer printing coating is reduced to a certain extent, the transfer printing coating is favorably attached to the surface of a printing stock, and the situation that the transfer printing effect is reduced due to transverse dissipation of dye in a poor contact area is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of transfer paper, in particular to a coating slurry for low-residue thermal sublimation transfer paper, a preparation method thereof and an application thereof. Background Art

[0002] Sublimation printing is a printing technology that uses heat to convert solid dye into gas (sublimation), which then penetrates and solidifies into the target material (usually polyester fiber or items with special coatings). It is mainly used to produce images with bright colors, rich details and very durable.

[0003] The operation process of thermal sublimation transfer includes the following steps: 1. Printing the pattern: Use a thermal sublimation printer to print the pattern on special transfer paper (the ink is a sublimation dye); 2. High-temperature transfer: Cover the transfer paper on the material and use heat and pressure in a thermal transfer machine to sublimate the dye and penetrate into the interior of the material; 3. After the shaping is completed, the transfer paper is torn off after cooling, and the pattern is firmly attached with no protrusions on the surface.

[0004] Sublimation transfer printing offers many advantages, including: excellent image quality, capable of achieving photo-quality printing effects with vibrant colors, smooth transitions, and sharp details; extremely high durability, not easily detached due to friction, particularly suitable for textiles (sportswear, flags), retaining its vibrant color after multiple machine washes, not easily scratched on hard objects, and resistant to UV fading; suitable for complex shapes, and with the use of special fixtures, patterns can be transferred to special-shaped items such as cups, hats, puzzles, keychains, and phone cases.

[0005] Sublimation transfer paper is a core consumable in the sublimation transfer process. It's a specialized paper coated with a special coating. Its core function is to temporarily hold the dye during the transfer process and efficiently release the sublimated dye gas when heated, allowing it to be smoothly transferred to the target object. This special coating is what distinguishes sublimation transfer paper from ordinary paper. The coating typically contains porous inorganic particles and an organic binder, forming a fine microporous structure. The special coating must exhibit high ink absorption, fast drying, dye fixation, and excellent dye release properties at high temperatures.

[0006] At present, there are still some problems with thermal sublimation transfer paper, including: 1. The ink easily penetrates into the base paper (paper layer), reducing the amount of ink on the coating, which leads to a reduction in the ink that can be transferred to the substrate during thermal sublimation transfer. The ink remains on the base paper, especially during low-temperature transfer, which affects the transfer effect. 2. When the surface flatness of the substrate is insufficient, if the hardness of the coating is too high, the coating will not fit the substrate well, and some gaps will appear. During the thermal sublimation transfer process, the ink will escape laterally, affecting the transfer effect. 3. Apply the coating slurry to the base paper (usually the slurry dosage is 4-8g / m 2), because the paper is thin, it is easy to curl after drying, which has a serious adverse effect on the subsequent transfer process.

[0007] In summary, it is necessary to develop a new technical solution to overcome the defects in the existing technology. Summary of the Invention

[0008] To address the above-mentioned issues, the present invention provides a low-residue coating slurry for sublimation transfer paper, its preparation method, and application. The low-residue coating slurry is prepared using acrylic latex, an ink-absorbing material, and a modified acrylic resin as raw materials. The modified acrylic resin not only helps improve the dispersibility of ingredients such as fillers and silica in the mixed emulsion, but also effectively prevents ink penetration and adheres to the substrate. When combined with heat-resistant ingredients such as cellulose, it improves the heat resistance and sublimation transfer performance of the low-residue sublimation transfer paper, demonstrating promising application prospects.

[0009] One object of the present invention is to provide a low-residue coating slurry for thermal sublimation transfer paper, wherein the low-residue coating slurry for thermal sublimation transfer paper comprises the following components in parts by mass:

[0010]

[0011] in,

[0012] The modified acrylic resin is a product obtained by polymerizing 1,3,5-benzenetricrylic acid, hydrophilic acrylic ester and long alkyl chain acrylic ester and then neutralizing with alkali.

[0013] Furthermore, the ink-absorbing material is selected from one or more of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and sodium carboxymethyl starch.

[0014] Furthermore, the surfactant is selected from one or more of silicone surfactants, fluorocarbon surfactants, and acetylene glycol surfactants.

[0015] Furthermore, the coating slurry for low-residue thermal sublimation transfer paper also includes a solvent, and the solvent is water.

[0016] Furthermore, the moisturizing agent is selected from one or more of propylene glycol, glycerol, and diethylene glycol.

[0017] Furthermore, the long alkyl chain acrylate is selected from one or more of lauryl acrylate, tridecyl acrylate, tetradecyl acrylate, pentadecyl acrylate, hexadecyl acrylate, heptadecyl acrylate, and octadecyl acrylate;

[0018] The hydrophilic acrylate is hydroxyalkyl acrylate.

[0019] Furthermore, the mass ratio of the 1,3,5-benzenetricrylic acid, the hydrophilic acrylate, and the long alkyl chain acrylate is 1:(0.1-1):(2-6).

[0020] Furthermore, the solid content of the coating slurry for low-residue thermal sublimation transfer paper is 25-30%.

[0021] Another object of the present invention is to provide a method for preparing the coating slurry for low-residue thermal sublimation transfer paper, the method comprising the following steps:

[0022] S1. Under an inert atmosphere, 1,3,5-benzenetricrylic acid, a hydrophilic acrylate, a long alkyl chain acrylate, an emulsifier, and water are mixed and emulsified, and then an initiator is added. The mixture is heated and stirred to react, and then neutralized with alkali to obtain a modified acrylic resin;

[0023] S2. Blending the modified acrylic resin, acrylic latex, ink-absorbing material, calcium carbonate, silicon dioxide, styrene-butadiene emulsion, surfactant, and moisturizer, and dispersing them uniformly at high speed to obtain a coating slurry for low-residue thermal sublimation transfer paper.

[0024] Furthermore, in step S1, the temperature of the heating and stirring reaction is 70-90° C., and the time of the heating and stirring reaction is 1-3 hours.

[0025] Another object of the present invention is to provide a use of the low-residue thermal sublimation transfer paper coating slurry in transfer paper.

[0026] Furthermore, the method includes: coating the low-residue thermal sublimation transfer paper coating slurry on the surface of the base paper, and obtaining the low-residue thermal sublimation transfer paper after the solvent is dried.

[0027] Furthermore, the coating amount is 4-8g / m 2 .

[0028] The present invention has the following beneficial effects:

[0029] The modified acrylic resin of the present invention is obtained by polymerizing 1,3,5-benzenetricrylic acid, hydroxyalkyl acrylate, and long alkyl chain acrylate, and then neutralizing with an alkali. On the one hand, the modified acrylic resin is conducive to enhancing the dispersion and emulsification effect of components such as silicon dioxide and calcium carbonate in the mixed emulsion, thereby enhancing the stability of the system. On the other hand, the modified acrylic resin has a body network structure, which is conducive to the transfer of most ink to the surface of the substrate during the thermal transfer process. Even when transferring at low temperatures, there is very little residual ink. This is because the body network structure prevents the ink from penetrating the paper layer, so that the thermal sublimation transfer has good color saturation and clarity, and avoids the occurrence of local color spots. Moreover, the long alkyl chain acrylate used is a flexible organic substance, which gives the modified acrylic resin good flexibility, thereby reducing the hardness of the transfer coating to a certain extent, which is conducive to the transfer coating being adhered to the substrate surface, avoiding the lateral dispersion of dye in poorly contacted areas, which causes a decrease in transfer effect, etc., so that the thermal sublimation transfer has good color saturation and clarity, and can avoid the occurrence of local color spots. In addition, the modified acrylic resin, silica and cellulose ink-absorbing material of the present invention have good high temperature resistance, which ensures the heat resistance of the transfer paper. The use of propylene glycol as a moisturizer effectively prevents the transfer paper from curling when drying, has a smoother surface, and further ensures the transfer effect of the transfer paper. DETAILED DESCRIPTION

[0030] In order to more clearly illustrate the technical solutions of the present invention, the following examples are given. Unless otherwise stated, the raw materials, reactions and post-processing methods mentioned in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0031] The terms "preferred," "preferably," "more preferred," and the like, used herein, refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

[0032] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties to be obtained by the present invention.

[0033] The examples of the present invention use the following raw materials:

[0034] Acrylic latex model L-2097 was purchased from Kaiming Plastic (Dongguan) Co., Ltd.

[0035] The initiator is ammonium persulfate;

[0036] The ink-absorbing material was sodium carboxymethyl cellulose with a viscosity of 50-200 mPa.s, purchased from Aladdin;

[0037] Calcium carbonate had a particle size of 2000 mesh and was purchased from Malin Mineral Products Processing Plant in Lingshou County;

[0038] Silica, model SA580, was purchased from Guangzhou Lingwei Technology Co., Ltd.;

[0039] Styrene-butadiene emulsion, model HY203145, was purchased from Shandong Haoyao New Materials Co., Ltd.

[0040] The surfactant was tetramethyldecynediol, Evonik 104E, Germany;

[0041] The emulsifier is sodium dodecylbenzenesulfonate;

[0042] The humectant is propylene glycol.

[0043] The “parts” in the embodiments of the present invention refer to parts by mass.

[0044] Example 1

[0045] A coating slurry for low-residue thermal sublimation transfer paper, comprising the following components in parts by weight:

[0046]

[0047] The method for preparing the coating slurry for low-residue thermal sublimation transfer paper comprises the following steps:

[0048] S1. Under a nitrogen atmosphere, 100 g of 1,3,5-benzenetricrylic acid, 80 g of hydroxyethyl acrylate, 600 g of lauryl acrylate, 70 g of emulsifier, and 1000 g of water were blended, emulsified with high-speed stirring, heated to 80° C., 7 g of initiator was added, and stirred for reaction for 3 h; the pH was adjusted to 8 with 20 wt % ammonia water, and the material was discharged to obtain a modified acrylic resin (solid content 43%);

[0049] S2. Blend the modified acrylic resin, acrylic latex, ink-absorbing material, calcium carbonate, silicon dioxide, styrene-butadiene emulsion, surfactant, humectant and water according to the above-mentioned parts by mass, and disperse them evenly at high speed to obtain a coating slurry for low-residue thermal sublimation transfer paper.

[0050] Example 2

[0051] A coating slurry for low-residue thermal sublimation transfer paper, comprising the following components in parts by weight:

[0052]

[0053] The method for preparing the coating slurry for low-residue thermal sublimation transfer paper comprises the following steps:

[0054] S1. Under a nitrogen atmosphere, 100 g of 1,3,5-benzenetricrylic acid, 70 g of hydroxyethyl acrylate, 300 g of lauryl acrylate, 300 g of octadecyl acrylate, 70 g of emulsifier and 1000 g of water were blended, emulsified with high-speed stirring, heated to 80° C., 7 g of initiator was added, and stirred for reaction for 3 h; the pH was adjusted to 8 with 20 wt % ammonia water, and the material was discharged to obtain a modified acrylic resin (solid content 42%);

[0055] S2. Blend the modified acrylic resin, acrylic latex, ink-absorbing material, calcium carbonate, silicon dioxide, styrene-butadiene emulsion, surfactant, humectant and water according to the above-mentioned parts by mass, and disperse them evenly at high speed to obtain a coating slurry for low-residue thermal sublimation transfer paper.

[0056] Example 3

[0057] A coating slurry for low-residue thermal sublimation transfer paper, comprising the following components in parts by weight:

[0058]

[0059]

[0060] The method for preparing the coating slurry for low-residue thermal sublimation transfer paper comprises the following steps:

[0061] S1. Under a nitrogen atmosphere, 100 g of 1,3,5-benzenetricrylic acid, 70 g of hydroxyethyl acrylate, 500 g of octadecyl acrylate, 70 g of emulsifier, and 1000 g of water were blended, emulsified with high-speed stirring, heated to 80° C., 7 g of initiator was added, and stirred for reaction for 3 h; the pH was adjusted to 8 with 20 wt % ammonia water, and the material was discharged to obtain a modified acrylic resin (solid content 43%);

[0062] S2. Blend the modified acrylic resin, acrylic latex, ink-absorbing material, calcium carbonate, silicon dioxide, styrene-butadiene emulsion, surfactant, humectant and water according to the above-mentioned parts by mass, and disperse them evenly at high speed to obtain a coating slurry for low-residue thermal sublimation transfer paper.

[0063] Comparative Example 1

[0064] The difference between Comparative Example 1 and Example 1 is that the mass of lauryl acrylate in step S1 is replaced by butyl acrylate, and the rest of the preparation method and ingredients are the same as those in Example 1.

[0065] Comparative Example 2

[0066] The difference between Comparative Example 2 and Example 1 is that the mass of 1,3,5-benzenetricrylic acid in step S1 is replaced by 1,4-benzenedicarboxylic acid, and the rest of the preparation method and ingredients are the same as those in Example 1.

[0067] Comparative Example 3

[0068] The difference between Comparative Example 3 and Example 1 is that the moisturizing agent is replaced by water, and the rest of the preparation method and ingredients are the same as those of Example 1.

[0069] Application Examples

[0070] The thermal sublimation transfer paper prepared in Example 1-3 and Comparative Example 1-3 was coated on the surface of the base paper with a coating amount of 6 g / m 2 , dried to obtain coated paper for thermal sublimation.

[0071] Test Example 1

[0072] The thermal sublimation coated papers prepared based on the examples and comparative examples were tested for thermal sublimation transfer effect and ink residue rate.

[0073] Test method:

[0074] The ink was printed on the low-residue sublimation coated paper prepared in the examples and comparative examples, and then transferred to cotton fabric by sublimation at a transfer temperature of 190° C. The color saturation, clarity, and local color spots were compared.

[0075] Use 22.5ml of DMF and 2.5ml of hydrochloric acid (1mol / L) solution to extract the ink on a 2cm×2cm low-residue sublimation coated paper. Then measure the absorbance A of the extract at the maximum absorption wavelength (λmax) on a UV-visible spectrophotometer (including before and after sublimation transfer). Then calculate the absorbance A as follows:

[0076] Ink transfer rate (%) = (A before - A after) / A before × 100%

[0077] Ink residual rate (%) = 100% - ink transfer rate (%).

[0078] The test results are shown in Table 1.

[0079] Table 1 Test results of thermal sublimation transfer effect and ink residual rate

[0080] sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Transfer paper appearance Smooth and flat Smooth and flat Smooth and flat Smooth and flat Smooth and flat Obvious curl Color saturation better better better slightly worse slightly worse / Clarity better better better slightly worse slightly worse / Localized spots none none none Small amount Small amount / Ink residual rate (%) 10 9 11 12 15 /

[0081] As can be seen from Table 1, Comparative Example 3, in which no moisturizer was added, showed severe curling after slurry coating and drying, which had a great impact on the subsequent thermal transfer process. The thermal sublimation transfer effect of Example 1-3 was better than that of Comparative Example 1-2. This is because Comparative Example 1 replaced lauryl acrylate with butyl acrylate, which reduced the flexibility relative to the lauryl acrylate group, reduced the flexibility of the modified acrylic resin, and increased the rigidity and hardness. When the flatness of the substrate surface was poor, the transfer coating could not fit the substrate well, and the ink escaped laterally, resulting in a poor thermal transfer effect, and the ink residue rate was slightly higher than that of Example 1-3; Comparative Example 2 replaced 1,3,5-benzenetriacrylate with 1,4-benzenedicarboxylic acid, reducing the double bonds that can react, reducing the crosslinking degree of the modified acrylic resin, and some ink penetrated from the transfer coating into the base paper, reducing the ink that was thermally sublimated to the substrate, resulting in a poor thermal transfer effect, and the ink residue rate was higher than that of Example 1-3.

[0082] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0083] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A coating slurry for low-residue thermal sublimation transfer paper, characterized in that: The coating slurry for low-residue thermal sublimation transfer paper includes the following components in parts by mass: in, The modified acrylic resin is a product obtained by polymerizing 1,3,5-benzenetricrylic acid, hydrophilic acrylic ester and long alkyl chain acrylic ester and then neutralizing with alkali.

2. The low-residue coating slurry for thermal sublimation transfer paper according to claim 1, characterized in that: The ink-absorbing material is selected from one or more of sodium carboxymethyl cellulose, hydroxyethyl cellulose, and sodium carboxymethyl starch.

3. The low-residue coating slurry for thermal sublimation transfer paper according to claim 1, characterized in that: The surfactant is selected from one or more of silicone surfactants, fluorocarbon surfactants, and acetylene glycol surfactants.

4. The low-residue coating slurry for thermal sublimation transfer paper according to claim 1, characterized in that: The coating slurry for low-residue thermal sublimation transfer paper further includes a solvent, and the solvent is water.

5. The low-residue coating slurry for thermal sublimation transfer paper according to claim 1, characterized in that: The moisturizing agent is selected from one or more of propylene glycol, glycerol, and diethylene glycol.

6. The low-residue coating slurry for thermal sublimation transfer paper according to claim 1, characterized in that: The long alkyl chain acrylate is selected from one or more of lauryl acrylate, tridecyl acrylate, tetradecyl acrylate, pentadecyl acrylate, hexadecyl acrylate, heptadecyl acrylate, and octadecyl acrylate; The hydrophilic acrylate is hydroxyalkyl acrylate.

7. The low-residue coating slurry for thermal sublimation transfer paper according to claim 1, characterized in that: The mass ratio of the 1,3,5-benzenetricrylic acid, the hydrophilic acrylate and the long alkyl chain acrylate is 1:(0.1-1):(2-6).

8. The method for preparing the coating slurry for low-residue thermal sublimation transfer paper according to any one of claims 1 to 7, characterized in that: The method for preparing the coating slurry for low-residue thermal sublimation transfer paper comprises the following steps: S1. Under an inert atmosphere, 1,3,5-benzenetricrylic acid, a hydrophilic acrylate, a long alkyl chain acrylate, an emulsifier, and water are mixed and emulsified, and then an initiator is added. The mixture is heated and stirred to react, and then neutralized with alkali to obtain a modified acrylic resin; S2. Blending the modified acrylic resin, acrylic latex, ink-absorbing material, calcium carbonate, silicon dioxide, styrene-butadiene emulsion, surfactant, and moisturizer, and dispersing them uniformly at high speed to obtain a coating slurry for low-residue thermal sublimation transfer paper.

9. The method for preparing the coating slurry for low-residue thermal sublimation transfer paper according to claim 8, characterized in that: In step S1, the temperature of the heating and stirring reaction is 70-90° C., and the time of the heating and stirring reaction is 1-3 hours.

10. Use of the low-residue coating slurry for thermal sublimation transfer paper according to any one of claims 1 to 7 in transfer paper.

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