Water-based dual-curing UV finishing paint gloss oil plastic coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a water-based dual-curing UV finish paint gloss oil plastic coating which comprises a component A, a component B and water, the component A comprises, by mass, 10-15 parts of water-based bifunctional polycarbonate UV resin, 20-25 parts of water-based dual-curing UV resin, 15-20 parts of water-based bifunctional UV acrylic acid modified UV resin, 10-15 parts of water-based bifunctional UV resin, 5-8 parts of UV monomer resin and 0.1-0.2 part of defoaming agent, and the component B comprises, by mass, 5-8 parts of water-based bifunctional UV acrylic acid modified UV resin, 10-15 parts of water-based bifunctional UV acrylic acid modified UV resin, 5-8 parts of water-based bifunctional UV acrylic acid modified UV resin and 0.1-0.2 part of defoaming agent. The water-based paint is prepared from the following components in parts by weight: 0.8-2.0 parts of a thickening agent, 5-10 parts of an alcohol ether coalescing agent, 0.5-1.5 parts of a base material wetting agent, 1-2 parts of a compound photoinitiator, 0.1-0.5 part of a flatting agent, 0-0.5 part of an ammonia water neutralizer and 10-20 parts of deionized water. And the component B is a water-based curing agent. According to the invention, uniform and consistent ultrahigh gloss, high hardness and high chemical resistance effects are realized on the surface of the plastic coated with the water-based paint, and meanwhile, good anti-scratch protective requirements are also met.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a water-based dual-curing UV topcoat varnish plastic coating. Background Art

[0002] After nearly 20 years of development, the market and technology of water-based plastic coatings have been well developed. The market has gradually shifted from products that simply meet environmental and health needs to environmentally friendly products with high performance, high gloss, high decorativeness and multi-functions. Since solvent-based dual-cure coatings have been widely recognized by the market and customers in many years of practical applications, the performance and application of water-based dual-cure UV plastic coatings will be more based on the performance and application of solvent-based coatings as the research and development direction. Since solvent-based dual-cure coatings have good gloss, hardness and chemical resistance, while water-based dual-cure plastic coatings have low gloss, soft hardness, and unstable storage, the automotive interiors and home appliances 3C surfaces painted with water-based dual-cure plastic coatings have serious uneven gloss and poor chemical resistance after long-term use. The paint film is easily damaged, affecting the appearance and decorative effect. Therefore, the development of water-based dual-cure plastic coatings with similar gloss, hardness and chemical resistance as solvent-based dual-cure coatings is the key research and development direction of technicians in this field. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a water-based dual-curing plastic coating, which uses water-based resin as raw material, and solves and realizes the uniform ultra-high gloss, high hardness, and high chemical resistance effect of the water-based paint-coated plastic surface through the combination of water-based resin and UV monomer with suitable additives, while also achieving good anti-scratch protection requirements, such as good blister resistance, boiling resistance, weather resistance, and chemical resistance.

[0004] The present invention adopts the following technical solutions:

[0005] A water-based dual-curing UV topcoat varnish plastic coating comprises a component A and a component B and water in a mass ratio of 100:(5-20):(10-15),

[0006] The component A comprises the following components in parts by mass: 10-15 parts of waterborne 2-official polycarbonate UV resin, 20-25 parts of waterborne dual-curing UV resin, 15-20 parts of waterborne 2-official UV acrylic modified UV resin, 10-15 parts of waterborne 6-official UV resin, 5-8 parts of UV monomer resin, 0.1-0.2 parts of defoamer, 0.8-2.0 parts of thickener, 5-10 parts of alcohol ether film-forming aid, 0.5-1.5 parts of substrate wetting agent, 1-2 parts of compound photoinitiator, 0.1-0.5 parts of leveling agent, 0-0.5 parts of ammonia neutralizer, and 10-20 parts of deionized water;

[0007] The B component is a water-based curing agent.

[0008] The composite photoinitiator is Jiuri New Material 184, TPO, and 819 mixed in a weight ratio of 2:7:1. Among them, 184 realizes the UV surface absorption curing effect, TPO realizes the UV deep absorption curing effect, and 819 realizes the UV or LED cold light source deep absorption curing effect. The coating with the composite photoinitiator is irradiated by UV light through a UV machine after coating, absorbs the energy of light, splits into 2 to 3 active free radicals, and initiates a chain polymerization reaction between UV resin and UV monomer diluent to achieve cross-linking curing. The composite photoinitiator is obtained by the inventor after a large number of experiments. Different photoinitiators and proportions have different curing effects. This combined photoinitiator is a composite photoinitiator with the best curing effect achieved by the selected UV resin. Other components and proportions may not be fully cured, the paint film is too soft, has no hardness and no adhesion, or it is over-cured, the internal stress is too large, the paint film is too hard and brittle, and has no adhesion.

[0009] The defoamer is Digo 902W, the thickener is Hemmings 299, the alcohol ether film-forming aid is Dow DB or DPNB, the substrate wetting agent is Digo 4100, the leveling agent is BYK333, and the ammonia neutralizer is Hemmings DMEA.

[0010] The water-based curing agent of component B is specifically Bayer 2655, which is diluted to 80% concentration with diluent propylene glycol diacetate. It is mixed with component A at a ratio of 15%, and the 2655 isocyanate curing agent is dispersed in the polycarbonate resin polyol particles, and begins to react with the hydroxyl and carboxyl groups in the water-based dual-curing UV resin to form a film within 24 hours. After the cross-linking is completed, ultraviolet light curing and isocyanate dual curing are formed to achieve ultra-high hardness, ultra-high gloss, high chemical resistance and various high mechanical excellent performance effects of the coating.

[0011] The preparation method of the above-mentioned water-based dual-curing UV topcoat varnish plastic coating is as follows:

[0012] S1. Place the water-based resin and UV monomer resin in a dispersion tank, add a defoamer, a thickener and a film-forming aid thereto under low-speed stirring, and mix them evenly to obtain a first material. The low-speed stirring speed is preferably 400-500 rpm, more preferably 450-500 rpm, to ensure that the emulsion will not break.

[0013] S2, adding a leveling agent, a substrate wetting agent, and an ammonia neutralizer to the first material, and dispersing them evenly under high-speed stirring to obtain a second material with a fineness of less than 25 μm. The speed of high-speed stirring is preferably 1000 rpm to 1300 rpm, and more preferably 1000 rpm to 1100 rpm.

[0014] S3. Mix the second material with the compounded photoinitiator and deionized water, stir at medium speed, adjust the viscosity of the obtained material to 80-90KU, and obtain component A; the medium-speed stirring speed in this step is preferably 650 rpm-800 rpm, more preferably 700-750 rpm; the medium-speed stirring time is preferably 15 minutes-25 minutes, more preferably 20 minutes.

[0015] S4. Before use, component A, component B and water are mixed in a mass ratio of 100:(5-20):(10-15) to obtain a water-based dual-curing UV topcoat varnish plastic coating for coating.

[0016] The commonly used automobile interior and home appliance 3C plastic plates are treated with alcohol solvents, and the water-based dual-curing UV topcoat varnish plastic coating of the present invention is coated thereon to obtain 3C plastic plates coated with water-based dual-curing UV topcoat varnish plastic coating. The specific coating can be carried out by a spraying method well known to those skilled in the art, for example, the coating prepared by the present invention is placed in a 2.0 mm caliber spray gun and sprayed on the 3C plastic plate. The number of coatings is preferably 1; the wet film coating amount obtained by each coating is preferably 180 g / m 2 -250g / m 2 , more preferably 180-220g / m 2 ; The photocuring energy is 400-800 joules, the preheating temperature is 65°C-90°C, and the time interval between each coating is preferably 20 to 24 hours, more preferably 24 hours.

[0017] The present invention has the following beneficial effects:

[0018] The present invention realizes uniform ultra-high gloss, high hardness, and high chemical resistance of the water-based paint-coated plastic surface through the compatibility of water-based resin, UV monomer, water-based curing agent, and suitable auxiliary agents, and also realizes good anti-scratch protection requirements, such as good resistance to blistering, boiling, weathering, and chemicals. The water-based 2-functional and 6-functional resins improve the gloss, the 2-functional polycarbonate resin and the dual-curing resin improve the hardness and chemical resistance, the UV monomer is used to dilute the compatible resin to improve the gloss, hardness, and chemical resistance of the paint film, the photoinitiator is selected in proportion according to the total content of the resin to improve the crosslinking density of the paint film and control the internal stress value of the paint film, and a certain proportion of the curing agent is selected to completely crosslink with the hydroxyl and carboxyl groups of the resin in the paint film within 24 hours after the paint film is cured by ultraviolet light, thereby further improving the comprehensive performance of the paint film. DETAILED DESCRIPTION

[0019] The features and performance of the present invention are further described in detail below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and are not limitations of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The water-based dual-curing UV topcoat varnish plastic coating of Examples 1-5 is composed of component A and component B in a mass ratio of 100:15:15, wherein the formula table of component A of each example is shown in 1.

[0021] Table 1 Formula of component A in each embodiment (unit: weight parts):

[0022]

[0023]

[0024] In the above embodiment, the water-based 2-official polycarbonate resin is Haohui New Material 2541, the water-based dual-curing UV resin is Wuxing Material 8254, the water-based 2-official UV acrylic modified polyurethane resin is DISEN 6321, the 6-official water-based UV resin is Wanhua 2523, the UV monomer is Allnex TMPTA, the defoamer is Digo 902, the thickener is Hemmings 299, the film-forming aid is Dow DPNB, DB, the leveling agent is BYK333, the substrate wetting agent is Digo 4100, the photoinitiator is Rijiu New Material 184 and TPO and 819 compounded in a ratio of 2:7:1, the ammonia neutralizer is Hemmings DMEA, and the deionized water is water made from a commercially available deionized water machine.

[0025] The component B used in each embodiment is a water-based curing agent, specifically Bayer 2655, which is diluted with a diluent propylene glycol diacetate to a concentration of 80%.

[0026] The preparation method of the water-based dual-curing UV topcoat varnish plastic coating of the above-mentioned embodiments 1-5 is as follows:

[0027] S1, placing a water-based resin and a UV monomer resin in a dispersion tank, adding a defoamer, a thickener and a film-forming aid thereto under low-speed stirring at 450 rpm, and mixing them evenly to obtain a first material;

[0028] S2, adding a leveling agent, a substrate wetting agent, and an ammonia neutralizer to the first material, and dispersing them evenly under high-speed stirring to obtain a second material with a fineness of less than 25 μm. The high-speed stirring speed is preferably 1100 rpm.

[0029] S3. Mix the second material with the compounded photoinitiator and deionized water, stir at medium speed, adjust the viscosity of the obtained material to 80-90 KU, and obtain component A; the medium stirring speed in this step is 700 rpm, and the time is 20 minutes.

[0030] S4. Before use, component A, component B and water are mixed in a mass ratio of 100:15:15 to obtain a water-based dual-curing UV topcoat varnish plastic coating for coating.

[0031] The present invention provides comparative examples 1-3 to test and verify the effect of the compounded photoinitiator.

[0032] The other components of Comparative Examples 1-3 are the same as those of Example 1, except that the compound photoinitiator is replaced with the following components and proportions.

[0033] Comparative Example 1: Rijiu New Material 184: TPO: 819 = 30%: 30%: 40%,

[0034] Comparative Example 2: TPO 100%

[0035] Comparative Example 3: 184: TPO: 819 = 50%: 25%: 25%

[0036] The methods of use of the above-mentioned Examples 1-3 and Comparative Examples 1-3 are as follows:

[0037] Conventional home appliance 3C, automobile interior and other plastic sheets are treated with alcohol and other solvents, and the above-mentioned water-based dual-curing UV topcoat varnish plastic coating is applied on them to obtain 3C plastic sheets coated with water-based dual-curing UV topcoat varnish plastic coating and complete the 3C plastic sheet coating. The coating is evenly sprayed using a 2.0mm caliber Iwata NEW-101 gravity spray gun, and the coating amount is 200g / m 2 , the drying temperature is 70℃, the drying time is 1-2 hours, and then placed at room temperature, and the performance test is carried out after 7 days. The test method and performance test results are as follows:

[0038]

[0039] It can be seen from the test results in the above table that when used with a water-based curing agent, the water-based dual-curing UV topcoat varnish coating of the present invention has more obvious advantages than ordinary water-based plastic coating topcoat in both sensory tests and resistance tests. In addition, the composite photoinitiator of the present invention is a composite photoinitiator with the best curing effect achieved according to the selected UV resin compared to other types and ratios of photoinitiators. The paint film is moderately soft and hard, and has better adhesion on the plastic panel. The water-based dual-curing UV topcoat varnish plastic coating of the present invention has excellent performance and is extremely widely used in common household appliances 3C and automotive interior plastic products without affecting their performance.

[0040] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0041] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0042] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A water-based dual-curing UV topcoat varnish plastic coating, characterized by: It includes component A, component B and water in a mass ratio of 100:(5-20):(10-15), The component A comprises the following components in parts by mass: 10-15 parts of waterborne 2-official polycarbonate UV resin, 20-25 parts of waterborne dual-curing UV resin, 15-20 parts of waterborne 2-official UV acrylic modified UV resin, 10-15 parts of waterborne 6-official UV resin, 5-8 parts of UV monomer resin, 0.1-0.2 parts of defoamer, 0.8-2.0 parts of thickener, 5-10 parts of alcohol ether film-forming aid, 0.5-1.5 parts of substrate wetting agent, 1-2 parts of compound photoinitiator, 0.1-0.5 parts of leveling agent, 0-0.5 parts of ammonia neutralizer, and 10-20 parts of deionized water; The B component is a water-based curing agent.

2. The water-based dual-curing UV topcoat varnish plastic coating according to claim 1, characterized in that: The compound photoinitiator is Jiuri New Material 184, TPO, and 819 mixed in a weight ratio of 2:7:

1.

3. The water-based dual-curing UV topcoat varnish plastic coating according to claim 1, characterized in that: The defoamer is Digo 902W, the thickener is Hemmings 299, the alcohol ether film-forming aid is Dow DB or DPNB, the substrate wetting agent is Digo 4100, the leveling agent is BYK333, and the ammonia neutralizer is Hemmings DMEA.

4. The water-based dual-curing UV topcoat varnish plastic coating according to claim 1, characterized in that: The B component is preferably Bayer 2655, which is diluted with propylene glycol diacetate as a diluent to a concentration of 80%.

5. A method for preparing the water-based dual-curing UV topcoat varnish plastic coating according to any one of claims 1 to 4, characterized in that: S1, placing a water-based resin and a UV monomer resin in a dispersion tank, adding a defoamer, a thickener and a film-forming aid thereto under low-speed stirring, and mixing them evenly to obtain a first material; S2, adding a leveling agent, a substrate wetting agent, and an ammonia neutralizer to the first material, and stirring at high speed to obtain a second material; S3, mixing the second material with a composite photoinitiator, a leveling agent and deionized water, and adjusting the viscosity of the obtained material to 80-90 KU to obtain component A; S4. Before use, component A, component B and water are mixed in a mass ratio of 100:5-20:10-15 to obtain a water-based dual-curing UV topcoat varnish plastic coating for coating.

6. The method for preparing the water-based dual-curing UV topcoat varnish plastic coating according to any one of claims 1 to 4, characterized in that: The low-speed stirring speed described in S1 is 400-500 rpm.

Images