A kind of excimer nitrogen protection curing UV coating and its curing process

Abstract

The invention discloses a quasi-molecular nitrogen protection curing UV coating, comprising the following components in mass percentage: aliphatic polyurethane acrylate resin (six-functional resin): 20-60%, aliphatic polyurethane acrylate resin (two-functional resin): 20-40%, organosilicon modified acrylate resin: 8-30%, HDDA: 10-25%, photoinitiator: 3.5-9%, ultraviolet absorber: 0.5-2%, defoamer: 0.1-0.3%, leveling agent: 0.2-1%. The invention also discloses its curing process, the UV coating can produce a skin-feeling effect or a frosting effect, the conversion of the two different effects only requires adjusting the curing process of the UV coating without changing different paint varieties; the paint formula does not require frosting powder and matte powder, and the paint film can produce a frosting effect.

Description

Technical Field

[0001] The invention relates to the technical field of decorative articles, in particular to a quasi-molecular nitrogen protection curing UV coating and a curing process thereof. Background Art

[0002] Existing photocurable coatings refer to coating products that are activated after the photoinitiator absorbs UV energy under the irradiation of ultraviolet light (wavelength of 320-390nm), resulting in molecular rupture to form free radicals or cations, thereby initiating a chemical reaction of unsaturated double-bonded substances in the coating and curing into a film. UV paint has a fast curing speed and can achieve surface drying in a very short time through ultraviolet irradiation. When the coating changes from a wet film to a dry film, its shrinkage rate is large and the internal stress is relatively large, resulting in poor adhesion between coatings. The hardness of UV paint is generally stronger than other types of paint. Generally, the harder the coating, the more brittle and less wear-resistant it is, and the coating is also prone to cracking. When the hardness of the coating exceeds the requirement, as the surface of the coated object expands and contracts with heat or humidity, the surface paint film changes due to lack of elasticity and cannot deform with the slight deformation of the floor, resulting in cracks.

[0003] The Chinese invention with the publication number CN112175506A discloses a UV-curable coating and a preparation method thereof. The UV-curable coating comprises the following components in parts by weight: 10 to 70 parts of a difunctional aliphatic polyurethane acrylate resin; 5 to 20 parts of a difunctional polyester acrylate; 5 to 20 parts of a tetrafunctional polyurethane acrylate; 2 to 9 parts of a photoinitiator; 1 to 10 parts of a fluff powder; 0.1 to 2 parts of a hand-feeling agent; 0.5 to 2 parts of a wetting agent; 0.05 to 0.2 parts of a defoaming agent; 0.1 to 2 parts of a leveling agent; 5 to 30 parts of an active monomer; The problems existing in the UV-curable coating are: 1. One paint can only produce one decorative effect, and it cannot produce a second decorative effect by adjusting the paint curing process, such as the paint film of the excimer skin-feel UV paint can only produce a skin-feel effect, and the paint film of the excimer matte paint can only form a matte effect; 2. The matte paint on the market needs to add matte powder and matte powder. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a quasi-molecular nitrogen-protected UV curing coating and a curing process thereof that can achieve the transformation of two paint textures without changing the type of coating.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A quasi-molecular nitrogen protection curing UV coating comprises, in terms of mass percentage, 20-60% of aliphatic polyurethane acrylate resin (six-functional resin), 20-40% of aliphatic polyurethane acrylate resin (two-functional resin), 8-30% of organosilicon modified acrylate resin, 10-25% of HDDA, 3.5-9% of photoinitiator, 0.5-2% of ultraviolet absorber, 0.1-0.3% of defoamer, and 0.2-1% of leveling agent; the aliphatic polyurethane acrylate resin provides high crosslinking density and curing speed, and is conducive to deep curing; the high-functional resin undergoes polymerization and crosslinking under a light source of 175 nanometers or 185 nanometers under nitrogen protection. The cross-reaction can provide higher surface hardness and higher coating cross-linking density. Aliphatic polyurethane acrylate resin can provide a velvety touch effect because of its good elasticity and flexibility. In addition, the ultraviolet light wavelength of the excimer lamp is extremely short and single, and its penetrating power is at the nanometer level (molecular level). The thickness of the paint film formed by curing is also at the nanometer level. The nanometer-level ultra-thin paint film floats on the microgel paint liquid, and an uneven effect is produced at the microscopic level. The combination of the above two effects can produce a velvety touch. Silicone-modified acrylate resin can make the paint film have a good smooth feel. The smooth feel combined with the velvety feel can obtain a skin-feeling effect. The leveling agent mainly plays a leveling role and a smooth effect, helping to provide a smooth feel.

[0007] Furthermore, the viscosity of the produced UV coating is 1600±200 mPa.s / 25°C.

[0008] Furthermore, the ultraviolet absorber adopts auxiliary agent C; auxiliary agent C has a strong ultraviolet absorption function. Because it can absorb ultraviolet rays, it can control the curing degree of the microgel and thus control the subsequent excimer curing degree to ensure that the excimer curing can form a skin-feeling effect or a matte effect, and then achieve the transformation of the skin-feeling effect and the matte effect by adjusting the curing process.

[0009] Furthermore, the photoinitiator includes photoinitiator MBF: 2-7%, photoinitiator TPO: 0.5-2%; the photoinitiator MBF (methyl benzoylformate) mainly plays a role in curing the paint film and has good yellowing resistance, and the photoinitiator TPO (diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide) mainly plays a role in deep curing, which is beneficial to ensure the adhesion of the paint film.

[0010] Furthermore, the defoamer is a silicone defoamer or a polyether defoamer.

[0011] A curing process for UV coatings cured by excimer nitrogen protection, including a curing process divided into three stages: the first stage: pre-curing the UV coating by LED lamp or gallium lamp to form a microgel state of the UV coating; the second stage: curing by excimer lamp nitrogen protection to cure the shallow surface of the UV coating; the third stage: full curing by mercury lamp to completely cure the paint film.

[0012] Furthermore, after absorbing ultraviolet rays of ultra-short wavelengths such as 175 nanometers or 185 nanometers, the acrylic double bonds in the UV coating can generate free radicals without the need for a photoinitiator.

[0013] Furthermore, the wavelength of the excimer lamp light source is between 175 and 185 nanometers.

[0014] Furthermore, the curing energy of the mercury lamp is greater than 800 mj / cm 2 .

[0015] Furthermore, in the second stage of excimer curing, only a very thin layer of the coating on the surface is cured. The polymerization and cross-linking of the thin layer will shrink, forming an uneven surface at the microscopic level and floating on the uncured underlying liquid, creating bumps and depressions at the microscopic level.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] 1. The same paint of the present invention can produce a skin-feel effect and a frosted effect. The conversion of the two different effects only requires adjusting the curing process of the UV coating without changing different paint varieties; the paint formula does not require frosted powder and matte powder, and the paint film can produce a frosted effect.

[0018] 2. Excimer nitrogen protection curing can make the paint film formed by curing the shallow surface paint float on the uncured paint liquid below, thereby achieving the matte effect of imitating the matte agent and the frosting effect of imitating the frosting powder. The degree of microgel curing of the early paint liquid can control the degree of subsequent excimer curing to ensure that the excimer curing can form a skin-feel effect or a frosting effect and is not easy to crack. Thus, the transformation of skin-feel effect and frosting effect can be achieved by adjusting the curing process.

[0019] 3. Since the coating of the present invention can be used as both skin-feel UV coating and frosted UV coating, coating R&D and production enterprises can reduce the number of coating formula SKUs and the types of coating products, thereby reducing the amount of manufacturing costs and production costs, and providing convenience for production and warehousing. For coating users, the types of stored products can be reduced, which is conducive to inventory preparation, reduces the error rate when taking out the goods, and improves production effects and quality stability. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0022] It should be noted that the terms "include", "comprises" and "have" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0023] A quasi-molecular nitrogen protection curing UV coating comprises, in terms of mass percentage, 20-60% of aliphatic polyurethane acrylate resin (six-functional resin), 20-40% of aliphatic polyurethane acrylate resin (bifunctional resin), 8-30% of organosilicon modified acrylate resin, 10-25% of HDDA, 3.5-9% of photoinitiator, 0.5-2% of ultraviolet absorber, 0.1-0.3% of defoamer, and 0.2-1% of leveling agent; the aliphatic polyurethane acrylate resin (six-functional resin) provides high cross-linking density and curing speed, and is conducive to deep curing; the polymerization and cross-linking reaction of the high-functional resin under nitrogen protection under a light source of 175 nanometers or 185 nanometers can provide higher surface hardness and higher coating cross-linking density; the aliphatic polyurethane acrylate resin (bi ... aliphatic polyurethane acrylate resin (bifunctional resin) provides high cross-linking density and curing speed, and is conducive to deep curing; the aliphatic polyurethane acrylate resin (bifunctional resin) provides high cross-link The polyurethane acrylate resin (polyurethane acrylate resin) can provide a velvety touch effect because of its good elasticity and flexibility. The aliphatic polyurethane acrylate resin (bifunctional resin) is a resin mixed according to the production process of polyurethane and acrylate. It combines the performance of polyurethane and acrylate resins and can provide an elastic feel in the paint film. In addition, the ultraviolet light wavelength of the excimer lamp is extremely short and single, and its penetrating power is at the nanometer level (molecular level). The thickness of the paint film formed by curing is also at the nanometer level. The nanometer-level ultra-thin paint film floats on the microgel paint liquid, and an uneven effect is produced at the microscopic level. The above two effects can produce a velvety touch. The silicone-modified acrylate resin can make the paint film have a good smooth feel. The smooth feel combined with the velvety feel can obtain a skin-feeling effect. The leveling agent mainly plays a leveling role and a smooth effect, and helps to provide a smooth feel.

[0024] The viscosity of the UV coating produced by the present invention is 1600±200mPa.s / 25℃; the ultraviolet absorber adopts auxiliary agent C; the auxiliary agent C has a strong ultraviolet absorption function, and because it can absorb ultraviolet rays, it can control the curing degree of the microgel and thus control the subsequent excimer curing degree, so as to ensure that the excimer curing can form a skin feeling effect or a frosting effect, and then achieve the transformation of the skin feeling effect and the frosting effect by adjusting the curing process; the photoinitiator includes photoinitiator MBF: 2-7%, photoinitiator TPO: 0.5-2%; the photoinitiator MBF (methyl benzoylformate) mainly plays a role in curing the paint film and has good yellowing resistance, and the photoinitiator TPO (diphenyl-(2,4,6-trimethylbenzoyl) phosphine) mainly plays a role in deep curing, which is beneficial to ensure the adhesion of the paint film; the defoamer is an organic silicon defoamer or a polyether defoamer.

[0025] The acrylic acid double bonds in the UV coating can generate free radicals after absorbing ultra-short wavelength ultraviolet rays of 175 nanometers or 185 nanometers, and no photoinitiator is required; the wavelength of the excimer lamp light source is between 175 and 185 nanometers; the curing energy of the mercury lamp is greater than 800 mj / cm 2 In the second stage of excimer curing, only a very thin layer of the coating surface is cured. The polymerization and cross-linking of the thin layer will shrink, forming an uneven surface at the microscopic level, and floating on the uncured lower layer of liquid, resulting in unevenness at the microscopic level. The second stage of curing needs to be carried out under nitrogen protection to keep the oxygen concentration in the operating environment below 100ppm. This matting method is also called physical matting because it does not require the use of a matting agent. At the same time, the polymerization and cross-linking that occur under a light source of 175 nanometers or 185 nanometers can provide high surface hardness and high coating density, thereby making the coating have better physical and chemical resistance. The excimer UV coating created by the present invention can be transformed between a frosted effect and a skin-feel effect by adjusting the curing process according to the needs of the decorative effect. At the same time, the frosted effect can be produced without adding matte powder and frosted powder to the paint formula. The research of the present invention fully utilizes the curing mechanism of UV paint, and fully utilizes the microgel theory and particle floating theory in the curing process. At the same time, the matting principle of the matting agent and the gradient curing principle of the paint liquid are used. The gradient curing principle of the paint liquid is the prerequisite for realizing the particle floating theory, the microgel theory is the basis for realizing the particle floating theory, and the matting principle of the matting agent is the basic principle and principle for designing this project.

[0026] Embodiment 1

[0027] A quasi-molecular nitrogen protection curing UV coating comprises, by mass percentage, 25% of aliphatic polyurethane acrylate resin (six-functional resin), 30% of aliphatic polyurethane acrylate resin (two-functional resin), 25% of organosilicon modified acrylate resin, 16% of HDDA, 2% of photoinitiator MBF, 0.5% of photoinitiator TPO, 1.2% of ultraviolet absorber, 0.1% of defoamer and 0.2% of leveling agent.

[0028] Embodiment 2

[0029] A quasi-molecular nitrogen protection curing UV coating comprises, by mass percentage, 31% of aliphatic polyurethane acrylate resin (six-functional resin), 26% of aliphatic polyurethane acrylate resin (two-functional resin), 20% of organosilicon modified acrylate resin, 18% of HDDA, 2% of photoinitiator MBF, 1% of photoinitiator TPO, 1.5% of ultraviolet absorber, 0.2% of defoamer and 0.3% of leveling agent.

[0030] Embodiment 3

[0031] A quasi-molecular nitrogen protection curing UV coating comprises, by mass percentage, 50% of aliphatic polyurethane acrylate resin (six-functional resin), 20% of aliphatic polyurethane acrylate resin (two-functional resin), 8% of organosilicon-modified acrylate resin, 10% of HDDA, 7% of photoinitiator MBF, 2% of photoinitiator TPO, 2% of ultraviolet absorber, 0.3% of defoamer and 0.7% of leveling agent.

[0032] Embodiment 4

[0033] A quasi-molecular nitrogen protection curing UV coating comprises, by mass percentage, 55% of aliphatic polyurethane acrylate resin (six-functional resin), 15% of aliphatic polyurethane acrylate resin (two-functional resin), 12% of organosilicon modified acrylate resin, 10% of HDDA, 3% of photoinitiator MBF, 2% of photoinitiator TPO, 2% of ultraviolet absorber, 0.3% of defoamer and 0.7% of leveling agent.

[0034] Embodiment 5

[0035] A quasi-molecular nitrogen protection curing UV coating comprises, by mass percentage, 60% of aliphatic polyurethane acrylate resin (six-functional resin), 12% of aliphatic polyurethane acrylate resin (two-functional resin), 8% of organosilicon modified acrylate resin, 10% of HDDA, 5% of photoinitiator MBF, 2% of photoinitiator TPO, 2% of ultraviolet absorber, 0.3% of defoamer and 0.7% of leveling agent.

[0036] The above five embodiment formulas are cured respectively, and excimer skin-feel paint and excimer matte paint are obtained respectively through different curing processes;

[0037] A curing process for UV coatings cured by excimer nitrogen protection, including a curing process divided into three stages: the first stage: pre-curing the UV coating by LED lamp or gallium lamp to form a microgel state of the UV coating; the second stage: curing by using excimer lamp nitrogen protection to cure the shallow surface of the UV coating; the third stage: full curing by using mercury lamp to completely cure the paint film, the microgel curing degree of the early UV coating liquid can control the subsequent excimer curing degree to ensure that the excimer curing can form a skin-feeling effect or a matte effect, wherein the model of the aliphatic polyurethane acrylate resin (six-functional resin) used in the present application is BC-601; the model of the aliphatic polyurethane acrylate resin (two-functional resin) is B-261; the model of the silicone-modified acrylate resin is ZC6562; the model of the auxiliary agent C is 400.

[0038] The performance of each embodiment cured into a skin-feel paint was tested:

[0039] Adhesion test: Tested in accordance with GB / T9286-1998;

[0040] Yellowing test: Energy 400mj / cm 2 , record the number of times the paint film starts to yellow;

[0041] Odor determination: Place the board in a sealed bag, and after 2 hours, open the bag and smell the odor;

[0042] Matte degree measurement: The glossiness of the paint film was tested using a gloss meter (60°).

[0043] Adhesion Number of yellowing after machine odor Matte Embodiment 1 0 13 none 5 Embodiment 2 0 16 none 4 Embodiment 3 0 14 none 6 Embodiment 4 0 15 none 7 Embodiment 5 0 14 none 7 Comparative Example 2 8 Low odor 13

[0044] The comparative example is Example 1 in CN112175506A. The difference between the comparative example and Examples 1 to 5 is that it contains plush powder, tetrafunctional polyurethane acrylate resin, and does not contain silicone modified acrylate resin. The paint film prepared in Comparative Example 1 is not fully cured, has a strong odor, and has a poor skin feel. At the same time, the yellowing resistance and adhesion are reduced.

[0045] In this case, Example 2 is selected as the best ratio, and the obtained UV coating has the best effect. Example 2 is compared with the UV paint currently on the market.

[0046] The coating of the present invention has the following advantages when used as excimer skin-feel paint compared to other UV skin-feel paints, as shown in Table 1.

[0047] Table 1: Comparison between this excimer skin-feel paint and other UV skin-feel paints

[0048] Paint film odor Skin effect Matte effect Scratch resistance Environmental impact Excimer skin-feel paint No odor Fluffy and refreshing feeling Matt surface is even and delicate Nail scratches without shiny marks Nitrogen protection, ozone free Other UV skin-feel paint Low odor Smooth skin feeling Delicate and slight blooming There are bright marks on the nail paint film Ozone pollution

[0049] The coating of the present invention has the following advantages when used as excimer frosted paint compared to other frosted paints, as shown in Table 2.

[0050] Table 2: Comparison between this excimer frosted paint and other frosted paints

[0051] Construction method Construction efficiency Coating components Coating solid content Paint film odor This excimer frosted paint Roller coating, solvent-free High, instant curing No scrub powder 100％ No odor Other matte paint Spray, with solvent Low, need to dry With sanding powder 60-80％ Smell

[0052] Tables 1 and 2 show that the UV coating of the present invention is environmentally friendly, the skin-feel paint has no odor when applied, and has a velvety and smooth texture to the touch, with a more delicate effect and a higher texture than the skin-feel paint on the market. The matte paint of the present application has high construction efficiency, short curing time, no odor, and is easy to construct.

[0053] It should be noted that with the development of technology, newly developed materials may replace the resin. Auxiliary agent C is a UV absorber and can be replaced by UV absorbers of other brands. Therefore, the use of this material is replaceable. The above specific implementation methods are only preferred embodiments of the present invention and the technical principles used. Within the technical scope disclosed by the present invention, any changes, modifications, substitutions, combinations, and simplifications made by any technician familiar with the technical field without departing from the spirit and principles of the present invention should be equivalent replacement methods and should be covered within the protection scope of the present invention.

Claims

1. An excimer nitrogen protection curing UV coating, characterized in that, in terms of mass percentage: It is composed of hexafunctional aliphatic polyurethane acrylate resin: 20-60%, bifunctional aliphatic polyurethane acrylate resin: 20-40%, silicone modified acrylate resin: 8-30%, HDDA: 10-25%, photoinitiator: 3.5-9%, ultraviolet absorber: 0.5-2%, defoamer: 0.1-0.3%, leveling agent: 0.2-1%; The viscosity of the UV coating is 1600±200 mPa•s / 25℃; The ultraviolet absorber adopts the auxiliary agent Tinuvin®400; The photoinitiator comprises photoinitiator MBF: 2-7% and photoinitiator TPO: 0.5-2%.

2. The excimer nitrogen protection curing UV coating according to claim 1, characterized in that: The defoamer is an organosilicon defoamer or a polyether defoamer.

3. A curing process for a UV coating cured by excimer nitrogen protection according to any one of claims 1 to 2, characterized in that: It includes three stages: the first stage: pre-curing the UV coating by LED lamp or gallium lamp to make the UV coating form a microgel state; The second stage: Use nitrogen protection curing with an excimer lamp to cure the shallow surface of the UV coating; The third stage: Use a mercury lamp for full curing to completely cure the paint film. In the second stage of excimer curing, only a very thin layer of the coating on the surface is cured. The polymerization and cross-linking of the thin layer will shrink, forming an uneven surface at the microscopic level and floating on the uncured lower layer of liquid, creating bumps and depressions at the microscopic level.

4. The curing process according to claim 3, characterized in that: After absorbing ultraviolet rays with an ultra-short wavelength of 175 nanometers or 185 nanometers, the acrylic acid double bonds in the UV coating can generate free radicals without the need for a photoinitiator.

5. The curing process according to claim 3, characterized in that: The wavelength of the excimer lamp light source is between 175 and 185 nanometers.

6. The curing process according to claim 5, characterized in that: The mercury lamp curing energy is greater than 800mj / cm 2 .