Pyrography transfer printing film and preparation method thereof

Abstract

The invention discloses a pyrograph transfer film and a preparation method thereof, and belongs to the technical field of transfer films, the pyrograph transfer film comprises a PET release film, a printing protection layer, a printing layer and a modified adhesive layer; the printing protective layer is formed by a printing protective agent, the printing protective agent is composed of a component A and a component B according to the mass ratio of 105-223: 100, and the component A comprises hyaluronic acid, dopamine hydrochloride and nano organic zirconium; the component B comprises ionic liquid and an anti-aging agent; the modified adhesive layer is formed by a modified adhesive, and the modified adhesive is prepared by mixing styrene-butadiene latex, starch-based microgel microspheres and an ultraviolet light absorber according to the mass ratio of (80-100): (8-15): (1-3). The adhesive force between the printing protection layer and the printing layer is high, the prepared pyrograph transfer film has the advantages of being high in adhesive force, resistant to scraping, resistant to moisture, resistant to high temperature, good in weather resistance and the like, the printing layer is not prone to aging, fading, deformation, blistering, wrinkling and the like, and the transfer decoration effect of the pyrograph transfer film is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of transfer films, and particularly relates to a heat transfer film for ironing and its preparation method. Background Art

[0002] A heat transfer film for ironing is a material used to transfer patterns, words, etc. onto the surfaces of fabrics, plastics and other materials. It generally consists of a base layer, a release layer, a printing layer and an adhesive layer.

[0003] For example, the invention patent CN111016488A discloses a transfer film for the surface of fitness equipment and its preparation method. The transfer film is composed of a base layer, a polyvinyl alcohol glue layer, a release layer, an ink absorption layer, a printing layer and an adhesive layer from bottom to top. The cured transfer film has the advantages of good scratch resistance, moisture resistance, and no cracks on the surface.

[0004] However, since it adopts a six-layer structure, the number of layers is relatively large. Since each additional layer structure adds process steps such as coating, drying, and curing of a coating layer, the production efficiency is reduced; at the same time, the ink absorption layer is prepared from hollow plastic pigments and nanoscale silica, and the adhesion between the ink absorption layer and the printing layer is low, and the weather resistance needs to be further improved. Problems such as aging, fading, and deformation may occur in the printing layer, reducing the transfer decoration effect.

[0005] Based on this, the present invention designs a heat transfer film for ironing and its preparation method to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned disadvantages existing in the prior art, the present invention provides a heat transfer film for ironing and its preparation method.

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] A heat transfer film for ironing includes a PET release film, a printing protection layer, a printing layer and a modified adhesive layer; the printing protection layer is formed by a printing protectant, and the printing protectant is composed of component A and component B in a mass ratio of 105-223:100. Component A includes: hyaluronic acid, dopamine hydrochloride, nano-organic zirconium; Component B includes: ionic liquid, anti-aging agent; the modified adhesive layer is formed by a modified adhesive, and the modified adhesive is prepared by mixing styrene-butadiene latex, starch-based microgel microspheres, and ultraviolet absorber in a mass ratio of 80-100:8-15:1-3.

[0009] Furthermore, the PET release film includes a PET base layer and a release layer coated on the PET base layer.

[0010] Furthermore, the anti-aging agent is an antioxidant, which can be antioxidant 1010 or antioxidant 246.

[0011] Further, the nano-organic zirconium is tetra-n-propyl zirconate.

[0012] Further, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or N-ethylimidazolium bis(trifluoromethylsulfonyl)imide.

[0013] Further, in component A, the mass ratio of hyaluronic acid, dopamine hydrochloride, and nano-organic zirconium is 3.1-5.4:1.5-2.2:5.7-6.6.

[0014] Further, in component B, the mass ratio of the ionic liquid to the anti-aging agent is 8.2-10.4:1.3-2.2.

[0015] Further, the preparation method of the printing protective agent is as follows:

[0016] Step (1): Mix the ionic liquid and the anti-aging agent to obtain component B;

[0017] Step (2): Add hyaluronic acid to deionized water to prepare a 0.5-1.3% wt aqueous hyaluronic acid solution. Then slowly drop the nano-organic zirconium into the aqueous hyaluronic acid solution, with the dropping rate controlled at 20-40 drops / min. Stir while dropping. Finally, adjust the pH of the solution to 5.5-6.5 with a hydrochloric acid solution. Add dopamine hydrochloride to the mixed solution obtained in the previous step and carry out a dark reaction for 5-10 h under nitrogen protection to obtain component A;

[0018] Step (3): Mix component A and component B, and at the same time irradiate the solution with γ-rays, with the radiation dose rate controlled at 20-40 Gy / h to obtain the printing protective agent.

[0019] Further, the preparation method of the starch-based microgel microspheres is as follows: Add 8-10 parts of starch to deionized water to obtain a starch dispersion. Add 120-150 parts of liquid paraffin as the oil phase to the reaction vessel, add 5-8 parts of Span-80 emulsifier to the oil phase, stir evenly to fully dissolve the emulsifier in the oil phase, slowly drop the prepared starch dispersion into the oil phase containing the emulsifier, and stir at the same time to form a stable emulsion. Add a 10-15% wt sodium hydroxide solution to the emulsion to adjust the pH to 9.5-10.5. Then slowly drop 3-5 parts of epichlorohydrin cross-linking agent. After dropping, continue to stir and react at 40-60 °C for 2-3 h. Then separate the starch-based microgel microspheres and wash them multiple times.

[0020] To better achieve the object of the present invention, the present invention also provides a method for preparing a heat transfer film, the steps are as follows: Coating a printing protective agent on a PET release film, and drying to form a printing protective layer; then printing printing layer ink on the printing protective layer by a printing press, and drying to form a printing layer; finally, coating a modified adhesive on the printing layer, and drying to form a modified adhesive layer; the thickness of the PET release film is 20-25 μm; the thickness of the printing protective layer is 0.3-0.7 μm.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. On the basis of the four-layer basic structure, the heat transfer film of the present invention only adds a printing protective layer. Compared with the transfer film with a six-layer structure, the preparation process of the present invention is simpler, which is beneficial to improving production efficiency;

[0022] 2. The adhesion between the printing protective layer and the printing layer of the present invention is high. The prepared heat transfer film has the advantages of strong adhesion, scratch resistance, moisture resistance, high temperature resistance and good weather resistance. The printing layer is not prone to problems such as aging, fading, deformation, blistering and wrinkling, ensuring the transfer decoration effect of the heat transfer film. Specific embodiments

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment 1: In some embodiments, the method for preparing a heat transfer film includes the following steps:

[0025] Step 1: Raw material preparation:

[0026] PET release film: It includes a PET base layer and a release layer coated on the PET base layer; the release layer is formed by an organosilicon release agent; preferably, an organosilicon release agent without solvent silicone oil is used.

[0027] Printing protective agent: 8.2 parts of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1.3 parts of antioxidant 1010 are mixed to obtain component B; 3.1 parts of hyaluronic acid are added to deionized water to prepare a 0.5% wt aqueous hyaluronic acid solution. Then, 5.7 parts of tetra-n-propyl zirconate are slowly added dropwise to the aqueous hyaluronic acid solution at a dropping rate controlled at 20 drops / min while stirring. Finally, the pH of the solution is adjusted to 5.5 with a hydrochloric acid solution to obtain a mixed solution; 1.5 parts of dopamine hydrochloride are added to the mixed solution, and a dark reaction is carried out for 5 h under nitrogen protection to obtain component A; component A and component B are mixed according to a mass ratio of 105:100, and at the same time, the solution is irradiated with γ-rays at a radiation dose rate controlled at 20 Gy / h to obtain the printing protective agent.

[0028] Modified adhesive: 8 parts of starch are added to deionized water to obtain a starch dispersion; 120 parts of liquid paraffin are added to a reaction vessel as the oil phase, 5 parts of Span-80 emulsifier are added to the oil phase, and stirred evenly to fully dissolve the emulsifier in the oil phase. The prepared starch dispersion is slowly added dropwise to the oil phase containing the emulsifier while stirring (500 r / min) to form a stable oil-in-water (O / W) type emulsion; 10% wt sodium hydroxide solution is added to the emulsion to adjust the pH to 9.5; then 3 parts of epichlorohydrin crosslinking agent are slowly added dropwise, and after dropping, the reaction is continued to stir at 40 °C for 2 h; then the starch-based microgel microspheres are separated and washed multiple times. Styrene-butadiene latex, starch-based microgel microspheres, and ultraviolet absorber are mixed according to a mass ratio of 80:8:1 to obtain the modified adhesive.

[0029] Printing layer ink: Color thermal transfer ink;

[0030] Step 2: The printing protective agent is coated on the PET release film and dried to form a printing protective layer; then the printing layer ink is printed on the printing protective layer by a printing machine and dried to form a printing layer; finally, the modified adhesive is coated on the printing layer and dried to form a modified adhesive layer; the thickness of the PET release film is 20 μm; the thickness of the printing protective layer is 0.3 μm.

[0031] Example 2: In some embodiments, the preparation method of the heat transfer printing film comprises the following steps:

[0032] Step 1: Raw material preparation:

[0033] PET release film: It includes a PET base layer and a release layer coated on the PET base layer; the release layer is formed by an organosilicon release agent; preferably, an organosilicon release agent without solvent silicone oil is used.

[0034] Printing protective agent: Mix 10.4 parts of N-ethylimidazole bis(trifluoromethanesulfonyl)imide salt with 2.2 parts of antioxidant 246 to obtain component B; Add 5.4 parts of hyaluronic acid to deionized water to prepare a 1.3% wt aqueous hyaluronic acid solution. Then, slowly add 6.6 parts of tetra-n-propyl zirconate to the aqueous hyaluronic acid solution at a dropping rate controlled at 40 drops / min, stirring while dropping. Finally, adjust the pH of the solution to 6.5 with hydrochloric acid solution to obtain a mixed solution; Add 2.2 parts of dopamine hydrochloride to the mixed solution and carry out a dark reaction for 10 h under nitrogen protection to obtain component A; Mix component A and component B according to a mass ratio of 223:100, and at the same time irradiate the solution with γ-rays, with the radiation dose rate controlled at 40 Gy / h to obtain the printing protective agent.

[0035] Modified adhesive: Add 10 parts of starch to deionized water to obtain a starch dispersion; Add 150 parts of liquid paraffin as the oil phase to the reaction vessel, add 8 parts of Span-80 emulsifier to the oil phase, stir evenly to fully dissolve the emulsifier in the oil phase, and slowly drop the prepared starch dispersion into the oil phase containing the emulsifier while stirring (800 r / min) to form a stable oil-in-water (O / W) emulsion; Add a 15% wt sodium hydroxide solution to the emulsion to adjust the pH to 10.5; Then, slowly drop 5 parts of epichlorohydrin crosslinking agent, and continue to stir and react at 60 °C for 3 h after dropping; Then, separate the starch-based microgel microspheres and wash them multiple times. Mix styrene-butadiene latex, starch-based microgel microspheres, and ultraviolet absorber according to a mass ratio of 100:15:3 to obtain the modified adhesive.

[0036] Printing layer ink: Color thermal transfer ink;

[0037] Step 2: Coat the printing protective agent on the PET release film, dry it to form a printing protective layer; Then, print the printing layer ink on the printing protective layer through a printing machine, and dry it to form a printing layer; Finally, coat the modified adhesive on the printing layer and dry it to form a modified adhesive layer; The thickness of the PET release film is 25 μm; The thickness of the printing protective layer is 0.7 μm.

[0038] Example 3: In some embodiments, the preparation method of the heat transfer printing film comprises the following steps:

[0039] Step 1: Raw material preparation:

[0040] PET release film: It includes a PET base layer and a release layer coated on the PET base layer; The release layer is formed by an organosilicon release agent; Preferably, an organosilicon release agent without solvent silicone oil is used.

[0041] Printing protective agent: Mix 9 parts of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide with 2 parts of antioxidant 246 to obtain Component B; Add 4 parts of hyaluronic acid to deionized water to prepare a 1% wt aqueous hyaluronic acid solution. Then slowly add 6 parts of tetra-n-propyl zirconate dropwise to the aqueous hyaluronic acid solution at a dropping rate of 30 drops / min while stirring. Finally, adjust the pH of the solution to 6 with hydrochloric acid solution to obtain a mixed solution; Add 2 parts of dopamine hydrochloride to the mixed solution and carry out a dark reaction for 7 h under nitrogen protection to obtain Component A; Mix Component A and Component B according to a mass ratio of 150:100, and at the same time irradiate the solution with γ-rays, with the radiation dose rate controlled at 30 Gy / h to obtain the printing protective agent.

[0042] Modified adhesive: Add 9 parts of starch to deionized water to obtain a starch dispersion; Add 130 parts of liquid paraffin as the oil phase to a reaction vessel, add 6 parts of Span-80 emulsifier to the oil phase, and stir evenly to fully dissolve the emulsifier in the oil phase. Slowly add the prepared starch dispersion dropwise to the oil phase containing the emulsifier while stirring (700 r / min) to form a stable oil-in-water (O / W) emulsion; Add a 12% wt sodium hydroxide solution to the emulsion to adjust the pH to 10; Then slowly add 4 parts of epichlorohydrin crosslinking agent, and continue to stir and react at 50 °C for 2.5 h after dropping; Then separate the starch-based microgel microspheres and wash them multiple times. Mix styrene-butadiene latex, starch-based microgel microspheres, and ultraviolet absorber according to a mass ratio of 90:11:2 to obtain the modified adhesive.

[0043] Printing layer ink: Color thermal transfer ink;

[0044] Step 2: Coat the printing protective agent on a PET release film, dry it to form a printing protective layer; Then print the printing layer ink on the printing protective layer through a printing machine, dry it to form a printing layer; Finally, coat the modified adhesive on the printing layer, dry it to form a modified adhesive layer; The thickness of the PET release film is 22 μm; The thickness of the printing protective layer is 0.4 μm.

[0045] Comparative Example 1: Different from Example 3, it does not contain a printing protective layer.

[0046] Comparative Example 2: Different from Example 3, γ-rays are not used to irradiate the solution during the preparation process of the printing protective layer.

[0047] The preparation method of the printing protective agent is as follows: Mix 9 parts of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide with 2 parts of antioxidant 246 to obtain component B; Add 4 parts of hyaluronic acid to deionized water to prepare a 1% wt aqueous hyaluronic acid solution. Then, slowly drop 6 parts of tetra-n-propyl zirconate into the aqueous hyaluronic acid solution at a dropping rate controlled at 30 drops / min, stirring while dropping. Finally, adjust the pH of the solution to 6 with hydrochloric acid solution to obtain a mixed solution; Add 2 parts of dopamine hydrochloride to the mixed solution and carry out a dark reaction for 7 h under nitrogen protection to obtain component A; Mix component A and component B according to a mass ratio of 150:100 to obtain the printing protective agent.

[0048] Experimental example: After transferring the heat transfer printing films prepared in Examples 1-3 and Comparative Examples 1-2 to plastic parts and completely curing them, adhesion, scratch resistance, moisture resistance, high temperature resistance, and weather resistance tests were carried out. The results are shown in Table 1.

[0049] Adhesion test: GB / T 9286-2021.

[0050] Scratch resistance test: ASTM D4060, 500 g load, 1200 cycles. There are four grades: excellent, good, general, and poor.

[0051] Moisture resistance test: Place the plastic parts in an environment of 38°C × 100% RH for 144 h and observe the appearance changes.

[0052] High temperature resistance test: Place the plastic parts in an environment of 95°C for 168 h and observe the appearance changes.

[0053] Weather resistance test: ISO 105-B06, using a xenon lamp accelerated aging chamber, total irradiation dose 1240.8 KJ / m 2 .

[0054] Table 1 Performance test results

[0055] Project Adhesion Scratch resistance Moisture resistance High temperature resistance Weather resistance Example 1 Grade 0 Excellent No change No change No change Example 2 Grade 0 Excellent No change No change No change Example 3 Grade 0 Excellent No change No change No change Comparative Example 1 Grade 1 Poor Wrinkling, discoloration Bubbling, discoloration Fading, deformation Comparative Example 2 Grade 0 Average Wrinkling Bubbling Deformation

[0056] Based on the four-layer basic structure, the heat transfer printing film of the present invention only adds a layer of printing protection layer. Compared with the six-layer structure transfer film, the preparation process of the present invention is simpler, which is beneficial to improving production efficiency;

[0057] The adhesion between the printing protection layer and the printing layer of the present invention is high. The prepared heat transfer printing film has the advantages of strong adhesion, scratch resistance, moisture resistance, high temperature resistance, and good weather resistance. The printing layer is not prone to problems such as aging, fading, deformation, blistering, and wrinkling, ensuring the transfer decoration effect of the heat transfer printing film.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat transfer film, characterized in that: It includes a PET release film, a printing protection layer, a printing layer and a modified adhesive layer; The printing protection layer is formed by a printing protection agent, which is composed of component A and component B in a mass ratio of 105-223:100, component A includes: hyaluronic acid, dopamine hydrochloride, nano-organic zirconium; component B includes: ionic liquid, anti-aging agent; the modified adhesive layer is formed by a modified adhesive, which is prepared by mixing butadiene-styrene latex, starch-based microgel microspheres, and ultraviolet absorbers in a mass ratio of 80-100:8-15:1-3.

2. The heat transfer film according to claim 1, characterized in that: The PET release film comprises a PET base layer and a release layer coated on the PET base layer.

3. The heat transfer film according to claim 1, characterized in that: The anti-aging agent is an antioxidant, which may be antioxidant 1010 or antioxidant 246.

4. The heat transfer film according to claim 1, characterized in that: The nano organic zirconium is tetra-n-propyl zirconate.

5. The heat transfer film according to claim 1, characterized in that: The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt or N-ethylimidazolium bis(trifluoromethanesulfonyl)imide salt.

6. The heat transfer film according to claim 1, characterized in that: In component A, the mass ratio of hyaluronic acid, dopamine hydrochloride and nano-organic zirconium is 3.1-5.4:1.5-2.2:5.7-6.

6.

7. The heat transfer film according to claim 1, characterized in that: In component B, the mass ratio of ionic liquid to anti-aging agent is 8.2-10.4:1.3-2.

2.

8. The heat transfer film according to claim 1, characterized in that: The preparation method of the printing protective agent is: Step (1): mixing the ionic liquid and the anti-aging agent to obtain component B; Step (2): adding hyaluronic acid to deionized water to prepare a 0.5-1.3%wt hyaluronic acid aqueous solution, then slowly dropping nano-organic zirconium into the hyaluronic acid aqueous solution, controlling the dropping speed at 20-40 drops / min, stirring while dropping, and finally adjusting the pH of the solution to 5.5-6.5 with a hydrochloric acid solution; adding dopamine hydrochloride to the mixed solution obtained in the previous step, and reacting in the dark under nitrogen protection for 5-10 hours to obtain component A; Step (3): Component A and component B are mixed, and the solution is irradiated with gamma rays at a radiation dose rate of 20 to 40 Gy / h to obtain a printing protective agent.

9. The heat transfer film according to claim 1, characterized in that: The preparation method of starch-based microgel microspheres is as follows: 8 to 10 parts of starch are added to deionized water to obtain a starch dispersion; 120 to 150 parts of liquid paraffin are added to a reaction container as an oil phase, 5 to 8 parts of Span-80 emulsifier are added to the oil phase, and stirred evenly to fully dissolve the emulsifier in the oil phase, and the prepared starch dispersion is slowly dripped into the oil phase containing the emulsifier while stirring to form a stable emulsion; 10 to 15% wt of sodium hydroxide solution is added to the emulsion to adjust the pH to 9.5 to 10.5; then 3 to 5 parts of epichlorohydrin crosslinking agent are slowly dripped, and after the dripping is completed, the reaction is continued to stir at 40 to 60° C. for 2 to 3 hours; then the starch-based microgel microspheres are separated and washed multiple times.

10. A method for preparing a heat transfer film according to any one of claims 1 to 9, characterized in that: The steps are: coating a printing protective agent on a PET release film, and forming a printing protective layer after drying; then printing a printing layer ink on the printing protective layer through a printing machine, and forming a printing layer after drying; finally coating a modified adhesive on the printing layer, and forming a modified adhesive layer after drying; the thickness of the PET release film is 20 to 25 μm; the thickness of the printing protective layer is 0.3 to 0.7 μm.