Environment-friendly water transfer printing peelable coating and use method thereof

Abstract

The invention relates to an environment-friendly water transfer printing peelable coating and a use method thereof, and belongs to the technical field of coating preparation and use. In order to further improve the performance of the coating, the filler diatomite is modified, and the specific surface area and the pore structure of the modified diatomite are optimized through the steps of grinding, dispersing and the like, so that the adsorbability and the dispersity of the modified diatomite are improved; due to the larger specific surface area and pore structure of the modified diatomite, components such as pigment and filler in the coating can be better adsorbed, and the uniformity and stability of the coating are improved; the coating is sprayed on the surface of a base material after being printed through a polyester screen or diluted, operation is easy and fast, the coating is suitable for large-scale production, hot air drying is adopted in the curing process, and the coating is more efficient and easy to control. After the protection task of the coating is completed, the coating can be directly peeled off in a hand tearing mode, the coating does not cause residues or damage to the surface of the base material, and follow-up machining and using of the base material are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation and use, and relates to an environmentally friendly water transfer peelable coating and a use method thereof. Background Art

[0002] With the increasing global environmental awareness, the application of traditional solvent-based coatings is gradually being restricted because they contain a large amount of volatile organic compounds (VOCs), which will have adverse effects on the environment and human health during manufacturing and use. In this context, water-based coatings have become an important direction for the development of the coatings industry due to their advantages such as low VOCs emissions, environmental friendliness and easy operation. As a decorative process widely used on the surfaces of various materials such as plastics, metals, and glass, the environmental performance of its coatings is also highly concerned.

[0003] Traditional water transfer coatings mostly use solvent-containing resin systems, which may release harmful substances during production and use. In addition, during the peeling process after transfer, the coating is often too strong in adhesion to the substrate or the peeling performance is poor, which leads to peeling difficulties or damage to the substrate surface, affecting the product's aesthetics and reprocessing performance. In addition, traditional coatings also face great environmental pressure during disposal.

[0004] In view of this, it is particularly important to develop a water transfer coating that meets environmental requirements and has good strippability. The present invention aims to provide an environmentally friendly water transfer strippable coating, which adopts a new water-based resin formula and combines specific functional additives to achieve excellent decorative effects while having good strippability and environmental friendliness. Summary of the invention

[0005] The purpose of the present invention is to provide an environmentally friendly water transfer peelable coating and a use method thereof, which has the characteristics of being scratch-resistant and peelable.

[0006] Press down on the panel surface. The hardness decreases from 3H to 3B. Record the hardness of the pen tip when a 3mm scratch appears. The results are used to rate the scratch resistance.

[0007] The water resistance of the embodiments and comparative examples was tested. 2 / 3 of the area of ​​the substrate after coating was placed in distilled water at a temperature of 23°C ± 2°C. After a certain period of time, it was taken out and the surface of the sample was observed to see whether there was blistering, gloss loss, discoloration, etc. The water resistance was ranked from high to low: no gloss loss, no discoloration > gloss loss, discoloration > blistering.

[0008] The peelability test was performed on the examples and comparative examples to observe whether there were residues or edge marks on the substrate surface after peeling.

[0009]

[0010] It can be seen from the examples and comparative examples that modification of diatomaceous earth effectively improves the scratch resistance, water resistance and peelability of the coating.

[0011] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An environmentally friendly water transfer peelable coating, characterized in that: The coating formula is as follows: by mass percentage, 50-60% waterborne polyurethane, 10-20% natural rubber, 5-10% polytetrahydrofuran, 4-7% modified diatomaceous earth, 1-3% organic silicon defoamer, 1-3% leveling agent, 2-3% dispersant, 10-15% deionized water, The preparation method of modified diatomite is as follows: S1.1: diatomaceous earth, alumina and graphene oxide were mixed in a mass ratio of (3-5):1:5, and ground in a ball mill at a speed of 400 r / min for 2 h to obtain a mixture A; S1.2: Dissolve corn starch in deionized water to obtain a corn starch solution with a mass fraction of 50-60%, disperse mixture A in the corn starch solution, the mass ratio of mixture A to corn starch is 1:1, and ultrasonicate for 2 hours to obtain a solid-liquid mixture B; S1.3: freezing the solid-liquid mixture B in liquid nitrogen for 15 to 20 minutes, drying it at -70 to -50°C under vacuum for 3 to 5 hours, and allowing it to stand at room temperature to obtain a solid mixture, and grinding the solid mixture in a ball mill at a speed of 500 r / min for 1 hour to obtain the modified diatomaceous earth; The coating is prepared as follows: S2.1: Mix waterborne polyurethane and polytetrahydrofuran according to the formula ratio, heat to 40°C, and stir in a mixer at a speed of 150 r / min for 3 hours to obtain a mixed component I; S2.2: Disperse the modified diatomaceous earth in deionized water, ultrasonicate for 2 h, heat to 140 °C, add natural rubber, stir at 200 r / min for 6 h in a mixer, cool to 60 °C at 5 °C / min after stirring, and obtain mixed component II; S2.3: After slowly heating the mixed component I to 60° C., add the mixed component II, and then add the silicone defoamer, the leveling agent and the dispersant, and continue to stir in the mixing mixer at a speed of 150 r / min for 1 hour to obtain the coating.

2. The environmentally friendly water transfer peelable coating according to claim 1, characterized in that: The organosilicon defoamer is one of BYK-141, BYK-077 and BYK-066N.

3. The environmentally friendly water transfer peelable coating according to claim 1, characterized in that: The leveling agent is one of GLIDE 450W and GLIDE 411.

4. The environmentally friendly water transfer peelable coating according to claim 1, characterized in that: The dispersant is polyethylene glycol, and the number average molecular weight is 20,000 to 30,000.

5. The environmentally friendly water transfer peelable coating according to claim 1, characterized in that: The rate of slow heating in S2.3 is 2°C / min.

6. A method for using an environmentally friendly water transfer peelable coating, based on the environmentally friendly water transfer peelable coating according to any one of claims 1 to 5, characterized in that: The coating is used as follows: S3.1: First, the surface of the substrate to be protected is purged with nitrogen at 40°C for 2 to 3 hours at a nitrogen flow rate of 20 m / s to obtain a substrate with a dry surface; S3.2: Print the coating on the surface of the substrate using a polyester screen or spray it on the surface of the substrate after dilution, let it stand, and obtain a cured coating after drying; S3.3: After use, the coating can be directly torn off by hand to complete the protection of the substrate surface.

7. The method for using the environmentally friendly water transfer peelable coating according to claim 6, characterized in that: The screen pores of the polyester screen printing in S3.2 are 50 to 100 meshes.

8. The method for using the environmentally friendly water transfer peelable coating according to claim 6, characterized in that: The parameters for spraying after dilution in S3.2 are: the volume ratio of deionized water to coating is (1-3):1, the spraying distance is 60 mm, and the spraying rate is 50 mm / s.

9. The method for using the environmentally friendly water transfer peelable coating according to claim 6, characterized in that: The coating thickness in S3.2 is 20 to 30 μm.

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