Uv light-resistant wood floor primer and preparation method thereof

Abstract

The application discloses a UV light-resistant wood floor primer and a preparation method thereof. The primer comprises the following components in percentage by weight: 30-60% of epoxy acrylic resin, 20-30% of active diluent, 3-6% of photoinitiator, 0.1-0.6% of defoaming agent, 0.3-1.0% of anti-settling agent, 1.0-5.0% of light stabilizer and 10-20% of filler. The preparation method comprises the following steps: uniformly dispersing the epoxy acrylic resin, the defoaming agent, the anti-settling agent, the photoinitiator, the light stabilizer and part of the active diluent; adding the filler and dispersing the filler to a fineness of less than 30 microns; and adjusting the viscosity to 4500-5500 mPa·s by using the remaining active diluent. The primer has the advantages of environmental protection, good adhesion, small odor, good yellowing resistance, UV resistance and the like, and effectively solves the problems of insufficient light aging durability and poor anti-wear synergistic protection of the existing wood floor primer.

Description

Technical Field

[0001] This invention belongs to the field of ultraviolet curable coating technology, specifically relating to a UV-resistant wood flooring primer and its preparation method. Background Technology

[0002] Wood flooring is widely used in home, commercial and public venue floor decoration due to its natural beauty, comfortable touch and good decorative effect.

[0003] However, wood flooring is exposed to indoor and outdoor light environments for a long time during use, especially under ultraviolet radiation. The chromophores such as lignin and tannin in the wood are prone to photochemical reactions, which can cause yellowing, fading or even loss of gloss on the floor surface, seriously affecting the product's appearance and service life. At the same time, the surface of wood flooring also has to withstand mechanical wear and tear from daily foot traffic and furniture movement, which further accelerates the aging of the coating.

[0004] Therefore, developing wood floor coatings that combine excellent resistance to light aging with good physical protection has become a pressing technical problem to be solved in this field.

[0005] Currently, most commercially available UV-cured primers for wood flooring use traditional light-cured resin systems, which mainly improve weather resistance by adding a small amount of light stabilizers or UV absorbers.

[0006] However, in practical applications, the following shortcomings have been found in the existing technology:

[0007] 1. Conventional formulations contain low levels of light stabilizers and lack multi-mechanism synergistic protection designs, making it difficult to maintain the color stability of the coating and underlying coloring layer under long-term, high-intensity ultraviolet irradiation. As a result, the floor surface is prone to noticeable yellowing or fading within a few months.

[0008] 2. In actual use, wood flooring is subjected to foot traffic and friction. Micro-damage to the surface coating can accelerate the penetration of ultraviolet light into the underlying layer. Most existing products are not optimized for the "wear-aging" coupled failure mode, and the protective effect decreases rapidly with the use of time.

[0009] 3. Some products use highly volatile organic solvents or aromatic diluents to improve leveling or enhance adhesion, resulting in a strong odor that makes it difficult to meet increasingly stringent indoor air quality standards.

[0010] In summary, existing UV primers for wood flooring still have significant shortcomings in terms of durability against light aging, synergistic protection against abrasion, and environmental friendliness. Designing a UV-resistant protective primer that combines high-efficiency UV shielding, good adhesion, low odor, high resistance to yellowing, and simple preparation process is a direction that urgently needs improvement in the current wood flooring coating field. Summary of the Invention

[0011] This invention addresses the problems of insufficient durability of UV primers for wood flooring in terms of light aging resistance, poor wear resistance and synergistic protection, and unsatisfactory environmental performance mentioned above. It provides a UV-resistant wood flooring primer and its preparation method.

[0012] This primer achieves a balance of high-efficiency UV shielding, good adhesion, low odor, and high resistance to yellowing through the selection and proportioning of specific components and an optimized preparation process.

[0013] To achieve the above objectives, the present invention adopts the following technical solution:

[0014] A UV-resistant wood flooring primer comprises the following components in weight percentage: 30%–60% epoxy acrylic resin; 20%–30% reactive diluent; 3%–6% photoinitiator; 0.1%–0.6% defoamer; 0.3%–1.0% anti-settling agent; 1.0%–5.0% light stabilizer; and 10%–20% filler.

[0015] Among them, epoxy acrylic resin, as the main film-forming material, has high UV reactivity and weather resistance, and can quickly cross-link and cure to form a dense coating, providing a solid framework for subsequent light-resistant protection.

[0016] The reactive diluent is used to adjust the viscosity of the system and participate in photocuring crosslinking, preferably DPGDA; the photoinitiator generates free radicals under ultraviolet light irradiation, which initiates the polymerization reaction between epoxy acrylate resin and reactive diluent, preferably methyl benzoylformate; the above two components work synergistically to ensure that the primer cures rapidly under low-energy ultraviolet light conditions, while reducing small molecule residues and odor.

[0017] The defoamer is used to suppress and eliminate bubbles generated during production and construction, and to avoid pinholes or craters in the coating. It is preferably a polysiloxane-polyether copolymer. The anti-settling agent is used to change the rheological properties of the system and impart thixotropy to prevent filler settling. It is preferably a modified polyurea. The introduction of these two additives ensures the storage stability and coating uniformity of the primer.

[0018] The light stabilizer is used to absorb or shield ultraviolet rays, slowing down the photodegradation and yellowing of the coating and wood flooring coloring layer, preferably T-888; the filler is used to improve the hardness and wear resistance of the coating, while reducing the shrinkage rate, preferably quartz; the light stabilizer and filler work together to block ultraviolet rays from penetrating and enhance the coating's ability to resist mechanical wear, thereby effectively addressing the "wear-aging" coupled failure mode.

[0019] The present invention also provides a method for preparing the above-mentioned UV-resistant wood flooring primer, comprising the following steps:

[0020] Step 1: Add epoxy acrylic resin, defoamer, anti-settling agent, photoinitiator, light stabilizer and part of reactive diluent into a dispersion container, and disperse at a medium speed of 1500-2500 rpm until uniform.

[0021] Step 2: Add filler to the dispersion container and continue to disperse at a medium speed of 1500-2500 rpm until the fineness is less than 30 micrometers;

[0022] Step 3: Adjust the viscosity of the system to 4500-5500 mPa·s with the remaining reactive diluent to obtain the UV-resistant wood flooring primer.

[0023] The preparation method is simple and easy to control, requiring no heating or special equipment, making it suitable for industrial production.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. By introducing sufficient light stabilizers and compounding them with highly reactive epoxy acrylic resins, the resulting coating can effectively absorb or shield ultraviolet rays. Under long-term irradiation, the yellowing value (ΔE*) is much lower than that of existing products, effectively protecting the color stability of the wood flooring stain layer.

[0026] 2. The addition of fillers improves the coating hardness and wear resistance, and reduces the accelerating effect of surface micro-damage on ultraviolet light intrusion; at the same time, the light stabilizer and the resin matrix form a dense protective layer, and the two work together to extend the service life of the floor under the combined effects of foot traffic and sun exposure.

[0027] 3. The system uses solvent-free reactive diluents, avoiding the use of highly volatile organic solvents or aromatic monomers. After curing, it has little odor and meets indoor air quality standards.

[0028] 4. The primer has moderate viscosity, is easy to apply by roller, and has good adhesion to the wood flooring substrate and subsequent topcoat.

[0029] In summary, this invention effectively overcomes the shortcomings of existing technologies, such as poor lightfastness, rapid degradation of protection, and insufficient environmental friendliness, and provides a UV-resistant wood flooring primer with superior overall performance and simple preparation. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the preparation process of the UV-resistant wood flooring primer of the present invention. Detailed Implementation

[0031] To enhance understanding of the present invention, the invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only for explaining the invention and do not constitute a limitation on the scope of protection of the invention.

[0032] like Figure 1As shown, the preparation process of the UV-resistant wood flooring primer of the present invention is as follows:

[0033] 1. Weigh the raw materials according to the following weight percentages: epoxy acrylate resin 30%–60%, reactive diluent (DPGDA) 20%–30%, photoinitiator (methyl benzoylformate) 3%–6%, defoamer (polysiloxane-polyether copolymer) 0.1%–0.6%, anti-settling agent (modified polyurea) 0.3%–1.0%, light stabilizer (T-888) 1.0%–5.0%, and filler (quartz) 10%–20%.

[0034] The reactive diluent is used in two parts: one part is used for initial mixing, and the other part is reserved for viscosity adjustment.

[0035] 2. Add epoxy acrylic resin, defoamer, anti-settling agent, photoinitiator, light stabilizer and the first part of reactive diluent to the dispersion container in sequence. Start the disperser and stir at a medium speed of 1500-2500 rpm until all components are mixed evenly and there is no visible agglomeration or stratification in the system.

[0036] In this step, the dispersion container is preferably made of stainless steel or plastic to avoid interference from metal ions with the photoinitiator.

[0037] 3. While keeping the disperser speed constant, slowly add the weighed packing material to the dispersion container and continue dispersing at a medium speed of 1500-2500 rpm. Use a scraper fineness meter to check the fineness of the system every 5 minutes until the fineness is less than 30 micrometers.

[0038] At this point, the filler is fully depolymerized and evenly distributed in the resin matrix.

[0039] 4. Stop the dispersion and take a small sample to measure the viscosity of the system using a rotational viscometer.

[0040] Based on the measured viscosity value, add the remaining reactive diluent to adjust the viscosity to 4500–5500 mPa·s (measured at 25°C).

[0041] Continue stirring at low speed for 5 minutes to make it uniform, and the UV-resistant wood flooring primer is obtained.

[0042] The above preparation method is carried out at room temperature, without the need for heating or vacuuming, and is simple to operate and suitable for large-scale production.

[0043] It should be noted that the proportion of reactive diluent can be flexibly adjusted according to the actual viscosity. Usually, the first part is 70% to 90% of the total amount of reactive diluent, and the remaining part is used for final adjustment to ensure that the viscosity can be precisely controlled after the fineness meets the standard.

[0044] Implementation Example

[0045] Example:

[0046] Weigh the raw materials according to the following weight percentages (total amount is 100%): epoxy acrylic resin (Kailin RY1101) 48.0%, reactive diluent (Zhanxin DPGDA) 24.0%, photoinitiator (double bond MBF) 4.5%, defoamer (Digo 920) 0.3%, anti-settling agent (BYK 410) 0.5%, light stabilizer (Tuan T-888) 3.0%, and filler (Liansheng PG-5 quartz) 19.7%.

[0047] Of the total amount of reactive diluent, 80% (i.e., 19.2%) is used for initial mixing, and the remaining 20% ​​(i.e., 4.8%) is reserved for viscosity adjustment.

[0048] The preparation is carried out according to steps 1 to 4 described in the specific implementation method: First, epoxy acrylic resin, defoamer, anti-settling agent, photoinitiator, light stabilizer and the first part of reactive diluent are added to a dispersion container and dispersed at 2000 rpm for 15 minutes until uniform; then filler is added and dispersion is continued at 2000 rpm for 30 minutes, and the fineness is detected as 25 micrometers; finally, the remaining reactive diluent is added and the viscosity is adjusted to 5100 mPa·s. The resulting primer is a uniform bluish-gray liquid.

[0049] Comparative example:

[0050] The only difference between the comparative example and the embodiment is that the light stabilizer (T-888) is not added, and the amount of epoxy acrylate resin is increased to 51.0% accordingly, while the other components and their amounts remain unchanged (24.0% reactive diluent, 4.5% photoinitiator, 0.3% defoamer, 0.5% anti-settling agent, and 19.7% filler).

[0051] The preparation steps were exactly the same as in the example, and the final viscosity was 5150 mPa·s. The appearance was also a bluish-gray uniform liquid.

[0052] Performance testing:

[0053] The primers prepared in the examples and comparative examples were each rolled onto the surface of the same batch of wood flooring substrates at a coating amount of 60 g / m², and then cured completely by irradiation with a UV curing lamp (energy 200 mJ / cm²).

[0054] After curing, the sample was placed in an accelerated aging test chamber and continuously irradiated for 7 days (simulating about 1 year of natural outdoor light).

[0055] After the test, the fading of the sample surface was observed, and the yellowing value (ΔE*, calculated with reference to the CIELab color difference formula) was measured using a colorimeter. The test results are summarized in Table 1.

[0056] Table 1 Comparison of performance test results between the examples and the comparative examples.

[0057] Example Slight fading 1.147 Qualified (≤2) Comparative Example Severe fading 4.204 Unqualified

[0058] As can be seen from the data in Table 1, after adding 3.0% of the light stabilizer T-888 in the examples, the photoaging resistance of the primer was significantly better than that of the control group without the addition. The yellowing value of the examples was only 1.147, which was far below the acceptance standard (ΔE*≤2), and only slight fading was observed. In contrast, the yellowing value of the control group was as high as 4.204, with obvious fading, and was judged to be unqualified. This shows that the light stabilizer selected in this invention can effectively absorb or shield harmful radiation under ultraviolet light irradiation, protecting the wood flooring coloring layer from rapid photodegradation.

[0059] In addition, the primer in this embodiment has little odor during construction, is smooth to apply by roller, and the adhesion of the coating after curing reaches level 0 in the cross-cut test. Furthermore, the addition of quartz filler increases the hardness of the coating to level HB to F (pencil hardness test), demonstrating good wear resistance potential.

[0060] In summary, the UV-resistant wood flooring primer provided by this invention is superior to existing products without light stabilizers in terms of yellowing resistance, adhesion, environmental friendliness, and wear resistance synergistic protection.

[0061] 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 principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A UV-resistant wood flooring primer, characterized in that, It contains the following components by weight percentage: Epoxy acrylic resin 30%–60%; 20%–30% reactive diluent; Photoinitiator 3%–6%; Defoamer 0.1%–0.6%; Anti-settling agent: 0.3%–1.0%; Light stabilizer 1.0%–5.0%; Filler content: 10%–20%.

2. The UV-resistant wood flooring primer according to claim 1, characterized in that: The active diluent is DPGDA.

3. The UV-resistant wood flooring primer according to claim 1, characterized in that: The photoinitiator is methyl benzoate.

4. The UV-resistant wood flooring primer according to claim 1, characterized in that: The defoamer is a polysiloxane-polyether copolymer.

5. The UV-resistant wood flooring primer according to claim 1, characterized in that: The anti-settling agent is a modified polyurea.

6. The UV-resistant wood flooring primer according to claim 1, characterized in that: The light stabilizer is T-888.

7. The UV-resistant wood flooring primer according to claim 1, characterized in that: The filler is quartz.

8. A method for preparing a UV-resistant wood flooring primer according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Add epoxy acrylic resin, defoamer, anti-settling agent, photoinitiator, light stabilizer and part of reactive diluent into a dispersion container, and disperse at a medium speed of 1500-2500 rpm until uniform. Step 2: Add filler to the dispersion container and continue to disperse at a medium speed of 1500-2500 rpm until the fineness is less than 30 micrometers; Step 3: Adjust the viscosity of the system to 4500-5500 mPa·s with the remaining reactive diluent to obtain the UV-resistant wood flooring primer.

9. The preparation method according to claim 8, characterized in that: The viscosity mentioned in step three is 4500–5500 mPa·s.

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