A kind of UV coating and preparation method thereof

Abstract

The invention discloses a UV coating and a preparation method thereof. The UV coating is composed of the following raw materials in percentage: 30-35% of a film former, 60-68% of an active diluent, and 0.1-1% of a photoinitiator. The beneficial effect is that the invention uses a prepolymer prepared by polymerization of diallyl phthalate as a main film former, tripropylene glycol diacrylate as an active diluent, and phenylphosphine oxide as an ultraviolet light initiator to prepare the UV strippable coating, so that the VOC content in the UV strippable coating is extremely low, and the coating can form a film quickly under ultraviolet light, and the coating has good flexibility and hardness, good strippability, and good water resistance, acid and alkali resistance, organic solvent resistance and rust resistance, so that the coating can be used for surface protection of various metal materials and products thereof, and the coating has a simple production process, low cost, fast film formation, convenient use, and extremely low pollution, and has an excellent development prospect.

Description

Technical Field

[0001] The invention relates to the technical field of UV curable strippable metal coatings, in particular to a UV coating and a preparation method thereof. Background Art

[0002] When temporarily protecting the surfaces of instruments, electronics, automobiles, machinery, buildings and metal materials, a layer of protective paint is often applied on the surfaces of instruments, electronics, automobiles, machinery, buildings and metal materials, and then peeled off after the protective effect is completed.

[0003] The strippable coatings currently used usually use volatile organic compounds such as toluene, xylene, ethyl acetate, and acetone as solvents, and vinyl resins, polyurethane resins, and acrylate resins as the main film-forming substances. While these coatings protect the surface of the material, a large amount of organic solvents evaporate into the atmosphere, affecting human health and environmental quality. In recent years, with the increasing calls for environmental protection, restrictions on VOC emissions into the atmosphere have become increasingly stringent, so the development of this type of coating has been restricted; water-based strippable coatings are a new development direction with low pollution and high raw material utilization, but the curing film-forming time is relatively long; UV-curing coatings are environmentally friendly coatings with the characteristics of no or low VOC emissions, fast curing speed, high production efficiency, and suitability for assembly line production. Therefore, UV-curing strippable coatings have great development prospects. Summary of the invention

[0004] The purpose of the present invention is to provide a UV coating and a preparation method thereof in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A UV coating and a preparation method thereof. The UV coating is composed of raw materials with the following percentage contents: 30-35% of a film former, 60-68% of an active diluent, and 0.1-1% of a photoinitiator.

[0007] Furthermore, the gel chromatography, infrared chromatography and iodine value of the surface prepolymer all showed that it had a certain cross-linking and curing ability. At the same time, the prepolymer began to degrade when the temperature rose to nearly 320°C, and the degradation rate was only 25% at 380°C, indicating that the prepolymer had good thermal stability and had the potential to prepare powder coatings.

[0008] Furthermore, the UV coating is preferably composed of raw materials in the following percentages: 33% film former, 66% active diluent, and 1% photoinitiator.

[0009] Furthermore, the film-forming agent is a prepolymer prepared by using ethanol as solvent and azobisisobutylcyanide as initiator to initiate the polymerization of diallyl phthalate.

[0010] Furthermore, the preparation method of the prepolymer is as follows: ethanol, azobisisobutyl cyanide and diallyl phthalate are mixed in a ratio of 15:1:50, and reacted at 80° C. for 4 hours to obtain the prepolymer.

[0011] Furthermore, the active diluent is tripropylene glycol diacrylate, and the photoinitiator is phenyl phosphine oxide.

[0012] Further, the preparation method of the UV coating is as follows:

[0013] Step 1: Prepare the prepolymer, reactive diluent and photoinitiator according to a specific ratio;

[0014] Step 2: Mix the prepolymer with the reactive diluent to ensure that the prepolymer is fully dissolved in the reactive diluent;

[0015] Step 3: Add the photoinitiator to the solution mixed in step 2, stir evenly, and let it stand for defoaming to obtain the UV curable strippable coating.

[0016] Furthermore, the ratio of the prepolymer to the reactive diluent in step 2 is 1:2.

[0017] Furthermore, the amount of the photoinitiator added in step 3 is 4% of the total weight of the UV coating.

[0018] Furthermore, the prepared UV coating sample was sealed and stored at a temperature of about 50°C for 30 days. There was no orange peel, no corruption smell, and no lumps on the coating surface, and it remained a clear, transparent light yellow liquid, proving that the coating had good storage stability.

[0019] Further studies have shown that the pencil hardness of the prepared UV coating film is 4H-5H, which can meet the use requirements. This is because there are more rigid benzene ring structures in the prepolymer, which makes the coating film have a higher hardness.

[0020] Further, the study showed that the prepared UV coating had very low adhesion on the surface of temporary protective tinplate and was easily peeled off in pieces.

[0021] The beneficial effects of the present invention are:

[0022] The invention uses a prepolymer prepared by polymerizing diallyl phthalate as a main film-forming material, tripropylene glycol diacrylate as an active diluent, and phenylphosphine oxide as an ultraviolet light initiator to prepare the UV strippable coating, so that the VOC content in the UV strippable coating is extremely low, the coating can quickly form a film under ultraviolet light, the coating has good flexibility and hardness, good strippability, and good water resistance, acid and alkali resistance, organic solvent resistance and rust resistance, so that the coating can be used for surface protection of various metal materials and products thereof, and the coating has a simple production process, low cost, fast film formation, convenient use, extremely low pollution, and excellent development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention provides a flow chart of a UV coating and a preparation method thereof. DETAILED DESCRIPTION

[0024] A UV coating and a preparation method thereof. The UV coating is composed of raw materials with the following percentage contents: 30-35% of a film former, 60-68% of an active diluent, and 0.1-1% of a photoinitiator.

[0025] In this embodiment, the gel chromatography, infrared chromatography and iodine value of the surface prepolymer all show that the prepolymer has a certain cross-linking and curing ability. At the same time, the prepolymer begins to degrade when the temperature rises to nearly 320°C, and the degradation rate is only 25% at 380°C, which shows that the prepolymer has good thermal stability and has the potential to prepare powder coatings.

[0026] In this embodiment, the UV coating is preferably composed of raw materials with the following percentages: 33% film former, 66% active diluent, and 1% photoinitiator.

[0027] In this embodiment, the film-forming agent is a prepolymer prepared by using ethanol as solvent and azobisisobutylcyanide as initiator to initiate the polymerization of diallyl phthalate.

[0028] In this embodiment, the preparation method of the prepolymer is as follows: ethanol, azobisisobutyl cyanide and diallyl phthalate are mixed in a ratio of 15:1:50, and reacted at 80° C. for 4 hours to obtain the prepolymer.

[0029] In this embodiment, the active diluent is tripropylene glycol diacrylate, and the photoinitiator is phenyl phosphine oxide.

[0030] In this embodiment, the preparation method of the UV coating is as follows:

[0031] Step 1: Prepare the prepolymer, reactive diluent and photoinitiator according to a specific ratio;

[0032] Step 2: Mix the prepolymer with the reactive diluent to ensure that the prepolymer is fully dissolved in the reactive diluent;

[0033] Step 3: Add the photoinitiator to the solution mixed in step 2, stir evenly, and let it stand for defoaming to obtain the UV curable strippable coating.

[0034] In this embodiment, the ratio of prepolymer to reactive diluent in step 2 is 1:2.

[0035] In this embodiment, the amount of the photoinitiator added in step 3 is 4% of the total weight of the UV coating.

[0036] In this embodiment, the prepared UV coating sample is sealed and stored at a temperature of about 50°C for 30 days. There is no orange peel, no corruption smell, no agglomeration on the coating surface, and it is still a clear, transparent light yellow liquid, which proves that the coating has good storage stability.

[0037] In this embodiment, the study shows that the pencil hardness of the prepared UV coating film is 4H-5H, which can reach

[0038] This is because there are more rigid benzene ring structures in the prepolymer, which makes the coating film have higher hardness.

[0039] In this embodiment, the study shows that the prepared UV coating has very low adhesion on the surface of temporary protective tinplate and is easily peeled off in pieces.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A UV coating and a preparation method thereof, characterized in that: The UV coating is composed of raw materials with the following percentages: 30-35% of a film former, 60-68% of an active diluent, and 0.1-1% of a photoinitiator.

2. A UV coating and a preparation method thereof according to claim 1, characterized in that: The UV coating is preferably composed of raw materials in the following percentages: 33% film former, 66% active diluent, and 1% photoinitiator.

3. A UV coating and a preparation method thereof according to claim 1, characterized in that: The film-forming agent is a prepolymer prepared by using ethanol as a solvent and azobisisobutylcyanide as an initiator to initiate the polymerization of diallyl phthalate.

4. A UV coating and a preparation method thereof according to claim 3, characterized in that: The preparation method of the prepolymer is as follows: ethanol, azobisisobutyl cyanide and diallyl phthalate are mixed in a ratio of 15:1:50, and reacted at 80° C. for 4 hours to obtain the prepolymer.

5. A UV coating and a preparation method thereof according to claim 1, characterized in that: The active diluent is tripropylene glycol diacrylate, and the photoinitiator is phenyl phosphine oxide.

6. A UV coating and a preparation method thereof according to any one of claims 1 to 5, characterized in that: The preparation method of the UV coating is as follows: Step 1: Prepare the prepolymer, reactive diluent and photoinitiator according to a specific ratio; Step 2: Mix the prepolymer with the reactive diluent to ensure that the prepolymer is fully dissolved in the reactive diluent; Step 3: Add the photoinitiator to the solution mixed in step 2, stir evenly, and let it stand for defoaming to obtain the UV curable strippable coating.

7. A UV coating and a preparation method thereof according to claim 6, characterized in that: In step 2, the ratio of the prepolymer to the active diluent is 1:

2.

8. A UV coating and a preparation method thereof according to claim 6, characterized in that: The amount of the photoinitiator added in step 3 is 4% of the total weight of the UV coating.

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