UV paint for SPC floor and preparation method thereof

Abstract

The invention relates to the technical field of UV paint for floors, in particular to UV paint for SPC floors and a preparation method of the UV paint. The UV paint for the SPC floor is prepared from the following raw materials in parts by mass: 50 to 100 parts of UV resin, 20 to 40 parts of 1, 6-hexanediol diacrylate, 20 to 40 parts of a mixed solvent, 5 to 15 parts of polystyrene microspheres, 1 to 5 parts of tetraethoxysilane, 0.1 to 1 part of sodium dodecyl benzene sulfonate, 0.1 to 1 part of a silane coupling agent, 1 to 2 parts of diphenylmethane diisocyanate, 1 to 2 parts of a flatting agent, 1 to 2 parts of a photoinitiator and 1 to 2 parts of a delustering agent, the UV resin comprises urethane acrylate with the functionality of 2 to 3 and urethane acrylate with the functionality of 4 to 6. The paint film obtained by the invention has the advantages of high curing speed, strong adhesive force, good flexibility and excellent wear resistance, and is especially suitable for preparing SPC floors.

Description

Technical Field

[0001] The present invention relates to the technical field of floor UV paints, and particularly relates to a UV paint for SPC floors and a preparation method thereof. Background Art

[0002] SPC floors, that is, stone plastic floors, are a new type of floor decoration material mainly made of natural stone powder and thermoplastic polymer materials. In recent years, due to their significant advantages such as environmental protection and pollution-free, waterproof and moisture-proof, wear-resistant and scratch-resistant, and convenient installation, they have been widely used in high-traffic scenarios such as commercial spaces, hospitals, and schools.

[0003] The structure of SPC floors usually includes a five-layer composite system: the bottom layer is a balance layer for moisture-proof and stability; the middle layer is a substrate layer, which is made by mixing high-density stone powder and PVC resin and determines the physical strength of the floor; the printing layer simulates wood grain or stone texture through pattern printing; the wear-resistant layer is the surface protection layer, which directly affects the service life of the floor; the outermost layer is a UV coating, which provides anti-fouling, scratch-resistant and decorative functions through ultraviolet curing.

[0004] However, the UV coatings of traditional SPC floors have shown obvious defects in long-term use. On the one hand, the conventional UV paint film has increased surface brittleness due to too high crosslinking density, insufficient adhesion to the floor substrate, and is prone to cracks due to thermal and cold deformation or mechanical stress, thereby affecting the wear resistance and decorative effect; on the other hand, existing technical solutions attempt to improve the performance by adding fillers such as organosilicon modified resin or nano-silica, but the former is difficult to be industrially promoted due to complex synthesis process and high cost, and the latter can improve the hardness but significantly reduce the flexibility of the coating film, resulting in peeling and falling off during the thermal expansion and contraction of the floor.

[0005] There is an urgent need for a UV coating solution with high wear resistance, flexibility and adhesion, which can not only meet the durability requirements of SPC floors in high-frequency use scenarios, but also overcome technical bottlenecks such as stress concentration and uneven filler dispersion in traditional processes. Summary of the Invention

[0006] The purpose of the present invention is to solve the defects existing in the prior art, and to propose a UV paint for SPC floors and a preparation method thereof.

[0007] A UV paint for SPC floors, the mass parts of its raw materials include: 50-100 parts of UV resin, 20-40 parts of 1,6-hexanediol diacrylate, 20-40 parts of mixed solvent, 5-15 parts of polystyrene microspheres, 1-5 parts of tetraethyl orthosilicate, 0.1-1 part of sodium dodecylbenzenesulfonate, 0.1-1 part of silane coupling agent, 1-2 parts of diphenylmethane diisocyanate, 1-2 parts of leveling agent, 1-2 parts of photoinitiator, and 1-2 parts of matting agent.

[0008] The UV resin includes: polyurethane acrylate with a functionality of 2 - 3 and polyurethane acrylate with a functionality of 4 - 6.

[0009] Preferably, the mass ratio of the polyurethane acrylate and the polyurethane acrylate is 5 - 10:1 - 4.

[0010] Preferably, the leveling agent is a silicone leveling agent.

[0011] Preferably, the photoinitiator is at least one of photoinitiator TPO, photoinitiator TPO - L, and photoinitiator 1173.

[0012] Preferably, the mixed solvent includes ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol monobutyl ether.

[0013] More preferably, the mass ratio of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol monobutyl ether is 5 - 10:1 - 5:1 - 2:1 - 2.

[0014] Preferably, the particle size of the polystyrene microspheres is 1 - 5 μm.

[0015] The preparation method of the above UV paint for SPC floor includes the following steps: S1. Add polystyrene microspheres, tetraethyl orthosilicate, and sodium dodecylbenzenesulfonate to an ethanol aqueous solution, stir for 10 - 30 min, adjust the pH value of the system to 4 - 5, perform ultrasonic treatment for 1 - 2 h, filter by suction, wash, and vacuum dry to obtain composite microspheres; S2. Add the composite microspheres to N,N - dimethylformamide, add KH550 coupling agent, reflux and stir at 70 - 80 °C for 1 - 2 h, add diphenylmethane diisocyanate and continue reflux and stir for 2 - 4 h, wash, filter by suction under reduced pressure, and vacuum dry to obtain activated composite microspheres; S3. Mix the UV resin, 1,6 - hexanediol diacrylate, and the mixed solvent evenly, add the activated composite microspheres thereto, stir at 60 - 80 °C for 1 - 2 h, cool to room temperature, and add the leveling agent, photoinitiator, and matting agent and mix evenly.

[0016] Preferably, in S1, the ultrasonic frequency is 40 - 60 kHz.

[0017] Preferably, in S1, 1 - 2 mol / L hydrochloric acid is used to adjust the pH value of the system to 4 - 5.

[0018] Beneficial effects:

[0019] The present invention adopts a core-shell structure of polystyrene microspheres coated with silica, which not only improves the dispersion uniformity of the filler in the resin matrix, but also absorbs the external impact stress received by the coating through the elastic deformation of the polystyrene shell. The silica provides hardness support, and the microcrack deflection structure formed at the core-shell interface can effectively prevent crack propagation, enabling the coating film to maintain integrity when subjected to rolling and friction.

[0020] The present invention uses a polyurethane acrylate with a functionality of 2-3 and a polyurethane acrylate with a functionality of 4-6 compounded as the UV resin, and reasonably controls the ratio of the two, which can effectively balance the wear resistance and adhesion of the paint film. In combination with the action of activated composite microspheres, it can effectively alleviate the volume shrinkage during the curing process of the paint film. Coating a layer of nano-silica shell on the surface of the polystyrene microspheres and then modifying with diphenylmethane diisocyanate can form a stable chemical bond with the UV resin, avoiding the phenomenon of surface peeling when the paint film is subjected to external force friction, and at the same time can form elastic deformation to effectively transfer stress, comprehensively improving the toughness of the coating film. Further combined with the action of 1,6-hexanediol diacrylate, a multi-layer network cross-linked structure can be generated during the curing process to form a uniform coating, which can not only effectively improve the adhesion of the paint film, but also make the paint film more stable.

[0021] The paint film obtained by the present invention not only has a fast curing speed, strong adhesion, but also good flexibility and excellent wear resistance. The present invention is particularly suitable for preparing SPC floors. It not only has simple preparation raw materials, but also strong adhesion, excellent flexibility, good practicability, is suitable for large-scale popularization and application, and at the same time its production process is simple and has good industrial application prospects. Specific embodiments

[0022] The present invention will be further explained below in conjunction with specific embodiments.

[0023] The polyurethane acrylate used below is from a certain chemical industry co., ltd. in Jining, with a functionality of 2 and a grade of RJ4234. The polyurethane acrylate used below is from a certain chemical materials co., ltd. in Guangzhou, with a functionality of 3 and a grade of FSP8006. The polyurethane acrylate used below is from a certain chemical industry co., ltd. in Jining, with a functionality of 4 and a grade of YC4100. The polyurethane acrylate used below is from DSM, with a functionality of 6 and a grade of AgiSyn230A2. Example 1

[0024] A UV paint for SPC floors, the raw materials of which include: 500 g of UV resin, 200 g of 1,6 - hexanediol diacrylate, 50 g of polystyrene microspheres with a particle size of 1 - 5 μm, 10 g of tetraethyl orthosilicate, 1 g of sodium dodecylbenzenesulfonate, 1 g of KH550 coupling agent, 10 g of diphenylmethane diisocyanate, 10 g of BYK - UV 3500, 10 g of photoinitiator TPO, 10 g of Bluecol L - 6314, and 200 g of mixed solvent.

[0025] The UV resin is composed of polyurethane acrylate with a functionality of 2 and polyurethane acrylate with a functionality of 4 in a mass ratio of 5:1. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol butyl ether in a mass ratio of 5:1:1:1.

[0026] The preparation method of the above - mentioned UV paint for SPC floors includes the following steps: S1. Add the polystyrene microspheres, tetraethyl orthosilicate, and sodium dodecylbenzenesulfonate to 400 g of an ethanol - aqueous solution with a mass fraction of 50%, stir at a speed of 100 r / min for 10 min, adjust the pH value of the system to 4 - 5 with 1 mol / L hydrochloric acid, perform ultrasonic treatment for 1 h with an ultrasonic frequency of 40 kHz, filter by suction, wash once with deionized water, and dry in vacuum to obtain composite microspheres; S2. Add the composite microspheres to 400 g of N,N - dimethylformamide, add the KH550 coupling agent, reflux and stir at 70 °C for 1 h with a stirring speed of 100 r / min, add diphenylmethane diisocyanate and continue reflux and stir for 2 h, wash repeatedly with N,N - dimethylformamide, filter by suction under reduced pressure, and dry in vacuum to obtain activated composite microspheres; S3. Mix the UV resin, 1,6 - hexanediol diacrylate, and the mixed solvent evenly, add the activated composite microspheres thereto, stir at 60 °C for 1 h, cool to room temperature, and add BYK - UV 3500, photoinitiator TPO, and Bluecol L - 6314 and mix evenly. Example 2

[0027] A UV paint for SPC floors, the raw materials of which include: 1000 g of UV resin, 400 g of 1,6 - hexanediol diacrylate, 150 g of polystyrene microspheres with a particle size of 1 - 5 μm, 50 g of tetraethyl orthosilicate, 10 g of sodium dodecylbenzenesulfonate, 10 g of KH550 coupling agent, 20 g of diphenylmethane diisocyanate, 20 g of BYK - UV 3500, 20 g of photoinitiator TPO, 20 g of Bluecol L - 6314, and 400 g of mixed solvent.

[0028] The UV resin is composed of polyurethane acrylate with a functionality of 2 and polyurethane acrylate with a functionality of 6 in a mass ratio of 10:4. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol butyl ether in a mass ratio of 10:5:2:2.

[0029] The preparation method of the above-mentioned UV paint for SPC floor includes the following steps: S1. Add polystyrene microspheres, tetraethyl orthosilicate, and sodium dodecylbenzenesulfonate to 600 g of an ethanol aqueous solution with a mass fraction of 65%, stir at a speed of 500 r / min for 30 min, adjust the pH value of the system to 4 - 5 with 2 mol / L hydrochloric acid, perform ultrasonic treatment for 2 h with an ultrasonic frequency of 60 kHz, filter by suction, wash with deionized water 3 times, and dry in vacuum to obtain composite microspheres; S2. Add the composite microspheres to 600 g of N,N - dimethylformamide, add KH550 coupling agent, reflux and stir at a temperature of 80 °C for 2 h with a stirring speed of 300 r / min, add diphenylmethane diisocyanate and continue reflux and stir for 4 h, wash repeatedly with N,N - dimethylformamide, filter by suction under reduced pressure, and dry in vacuum to obtain activated composite microspheres; S3. Mix the UV resin, 1,6 - hexanediol diacrylate, and the mixed solvent evenly, add the activated composite microspheres thereto, stir at a temperature of 80 °C for 2 h, cool to room temperature, and add BYK - UV 3500, photoinitiator TPO, and Bluecol L - 6314 and mix evenly. Example 3

[0030] A UV paint for SPC floor, the raw materials of which include: 700 g of UV resin, 350 g of 1,6 - hexanediol diacrylate, 120 g of polystyrene microspheres with a particle size of 1 - 5 μm, 20 g of tetraethyl orthosilicate, 7 g of sodium dodecylbenzenesulfonate, 3 g of KH550 coupling agent, 18 g of diphenylmethane diisocyanate, 12 g of BYK - UV 3500, 15 g of photoinitiator 1173, 15 g of Bluecol L - 6314, and 250 g of mixed solvent.

[0031] The UV resin is composed of polyurethane acrylate with a functionality of 3 and polyurethane acrylate with a functionality of 6 in a mass ratio of 9:2. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol butyl ether in a mass ratio of 9:2:1.8:1.2.

[0032] The preparation method of the above-mentioned UV paint for SPC floor includes the following steps: S1. Add polystyrene microspheres, tetraethyl orthosilicate, and sodium dodecylbenzenesulfonate to 550 g of an ethanol aqueous solution with a mass fraction of 55%, stir at a speed of 400 r / min for 15 min, adjust the pH value of the system to 4 - 5 with 1.5 mol / L hydrochloric acid, perform ultrasonic treatment for 100 min with an ultrasonic frequency of 45 kHz, filter by suction, wash twice with deionized water, and dry in vacuum to obtain composite microspheres; S2. Add the composite microspheres to 550 g of N,N - dimethylformamide, add KH550 coupling agent, reflux and stir at a temperature of 73 °C for 100 min with a stirring speed of 150 r / min, add diphenylmethane diisocyanate and continue refluxing and stirring for 3.5 h, wash repeatedly with N,N - dimethylformamide, filter by suction under reduced pressure, and dry in vacuum to obtain activated composite microspheres; S3. Mix UV resin, 1,6 - hexanediol diacrylate, and a mixed solvent evenly, add the activated composite microspheres thereto, stir at a temperature of 65 °C for 100 min, cool to room temperature, and add BYK - UV 3500, photoinitiator 1173, and Bluecol L - 6314 and mix evenly. Example 4

[0033] A UV paint for SPC floors, whose raw materials include: 900 g of UV resin, 250 g of 1,6 - hexanediol diacrylate, 80 g of polystyrene microspheres with a particle size of 1 - 5 μm, 40 g of tetraethyl orthosilicate, 3 g of sodium dodecylbenzenesulfonate, 7 g of KH550 coupling agent, 12 g of diphenylmethane diisocyanate, 18 g of BYK - UV 3500, 15 g of photoinitiator 1173, 15 g of Bluecol L - 6314, and 350 g of a mixed solvent.

[0034] The UV resin is composed of a polyurethane acrylate with a functionality of 3 and a polyurethane acrylate with a functionality of 6 in a mass ratio of 7:3. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol monobutyl ether in a mass ratio of 7:4:1.2:1.8.

[0035] The preparation method of the above - mentioned UV paint for SPC floors includes the following steps: S1. Add polystyrene microspheres, tetraethyl orthosilicate, and sodium dodecylbenzenesulfonate to 450 g of an ethanol aqueous solution with a mass fraction of 60%, stir at a speed of 200 r / min for 25 min, adjust the pH value of the system to 4 - 5 with 1.5 mol / L hydrochloric acid, perform ultrasonic treatment for 80 min with an ultrasonic frequency of 55 kHz, filter by suction, wash twice with deionized water, and dry in vacuum to obtain composite microspheres; S2. Add the composite microspheres into 450 g of N,N-dimethylformamide, add KH550 coupling agent, reflux and stir at 77 °C for 80 min, with the stirring speed of 240 r / min. Then add diphenylmethane diisocyanate and continue refluxing and stirring for 2.5 h. Wash repeatedly with N,N-dimethylformamide, carry out vacuum filtration under reduced pressure, and vacuum dry to obtain activated composite microspheres; S3. Mix the UV resin, 1,6-hexanediol diacrylate and mixed solvent evenly. Add the activated composite microspheres thereto, stir at 75 °C for 80 min, cool to room temperature, and then add BYK-UV 3500, photoinitiator 1173 and Blueway L-6314 and mix evenly. Example 5

[0036] A UV paint for SPC floor, the raw materials of which include: 800 g of UV resin, 300 g of 1,6-hexanediol diacrylate, 100 g of polystyrene microspheres with a particle size of 1-5 μm, 30 g of tetraethyl orthosilicate, 5 g of sodium dodecylbenzenesulfonate, 5 g of KH550 coupling agent, 15 g of diphenylmethane diisocyanate, 15 g of BYK-UV 3500, 15 g of photoinitiator TPO-L, 15 g of Blueway L-6314, and 300 g of mixed solvent.

[0037] The UV resin is composed of a polyurethane acrylate with a functionality of 3 and a polyurethane acrylate with a functionality of 6 according to a mass ratio of 8:2.5. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether and propylene glycol monobutyl ether according to a mass ratio of 8:3:1.5:1.5.

[0038] The preparation method of the above-mentioned UV paint for SPC floor includes the following steps: S1. Add the polystyrene microspheres, tetraethyl orthosilicate and sodium dodecylbenzenesulfonate into 500 g of an ethanol aqueous solution with a mass fraction of 58%, stir at a speed of 300 r / min for 20 min, adjust the pH value of the system to 4-5 with 1.5 mol / L hydrochloric acid, carry out ultrasonic treatment for 90 min with an ultrasonic frequency of 50 kHz, carry out suction filtration, wash twice with deionized water, and vacuum dry to obtain composite microspheres; S2. Add the composite microspheres into 500 g of N,N-dimethylformamide, add KH550 coupling agent, reflux and stir at 75 °C for 90 min, with the stirring speed of 200 r / min. Then add diphenylmethane diisocyanate and continue refluxing and stirring for 3 h. Wash repeatedly with N,N-dimethylformamide, carry out vacuum filtration under reduced pressure, and vacuum dry to obtain activated composite microspheres; S3. Mix the UV resin, 1,6 - hexanediol diacrylate, and the mixed solvent evenly. Add the activated composite microspheres thereto, stir at 70 °C for 90 min, cool to room temperature, and then add BYK - UV 3500, photoinitiator TPO - L, and Blueway L - 6314 and mix evenly.

[0039] Comparative Example 1 A UV varnish for SPC floors, the raw materials of which include: 800 g of UV resin, 300 g of 1,6 - hexanediol diacrylate, 100 g of polystyrene microspheres with a particle size of 1 - 5 μm, 30 g of tetraethyl orthosilicate, 5 g of sodium dodecylbenzenesulfonate, 5 g of KH550 coupling agent, 15 g of diphenylmethane diisocyanate, 15 g of BYK - UV 3500, 15 g of photoinitiator TPO - L, 15 g of Blueway L - 6314, and 300 g of mixed solvent.

[0040] The UV resin is composed of a polyurethane acrylate with a functionality of 3 and a polyurethane acrylate with a functionality of 6 in a mass ratio of 8:2.5. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol monobutyl ether in a mass ratio of 8:3:1.5:1.5.

[0041] The preparation method of the above - mentioned UV varnish for SPC floors includes the following steps: S1. Add tetraethyl orthosilicate and sodium dodecylbenzenesulfonate to 500 g of an ethanol aqueous solution with a mass fraction of 58%, stir at a speed of 300 r / min for 20 min, adjust the pH value of the system to 4 - 5 with 1.5 mol / L hydrochloric acid, perform ultrasonic treatment for 90 min with an ultrasonic frequency of 50 kHz, filter by suction, wash twice with deionized water, dry in vacuum, and then add polystyrene microspheres and mix evenly to obtain composite microspheres; S2. Add the composite microspheres to 500 g of N,N - dimethylformamide, add the KH550 coupling agent, reflux and stir at 75 °C for 90 min with a stirring speed of 200 r / min, add diphenylmethane diisocyanate and continue reflux and stir for 3 h, wash repeatedly with N,N - dimethylformamide, filter by suction under reduced pressure, and dry in vacuum to obtain activated composite microspheres; S3. Mix the UV resin, 1,6 - hexanediol diacrylate, and the mixed solvent evenly. Add the activated composite microspheres thereto, stir at 70 °C for 90 min, cool to room temperature, and then add BYK - UV 3500, photoinitiator TPO - L, and Blueway L - 6314 and mix evenly.

[0042] Comparative Example 2 A UV paint for an SPC floor, whose raw materials include: 800g of UV resin, 300g of 1,6-hexanediol diacrylate, 100g of polystyrene microspheres with a particle size of 1-5μm, 30g of tetraethyl orthosilicate, 5g of sodium dodecylbenzenesulfonate, 5g of KH550 coupling agent, 15g of diphenylmethane diisocyanate, 15g of BYK-UV 3500, 15g of photoinitiator TPO-L, 15g of Lancolu L-6314, and 300g of a mixed solvent.

[0043] The UV resin is composed of polyurethane acrylate with a functionality of 3 and polyurethane acrylate with a functionality of 6 in a mass ratio of 4:5. The mixed solvent is composed of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether and propylene glycol butyl ether in a mass ratio of 8:3:1.5:1.5.

[0044] The preparation method of the above-mentioned UV paint for SPC floor comprises the following steps: S1. Add polystyrene microspheres, tetraethyl orthosilicate and sodium dodecylbenzene sulfonate to 500 g of 58% ethanol aqueous solution, stir at 300 r / min for 20 min, adjust the pH value of the system to 4-5 with 1.5 mol / L hydrochloric acid, perform ultrasonic treatment for 90 min at an ultrasonic frequency of 50 kHz, filter, wash twice with deionized water, and vacuum dry to obtain composite microspheres; S2, adding the composite microspheres to 500g N,N-dimethylformamide, adding KH550 coupling agent, refluxing and stirring at a temperature of 75°C for 90min, stirring at a speed of 200r / min, adding diphenylmethane diisocyanate and continuing to reflux and stir for 3h, repeatedly washing with N,N-dimethylformamide, filtering under reduced pressure, and vacuum drying to obtain activated composite microspheres; S3. Mix UV resin, 1,6-hexanediol diacrylate and mixed solvent evenly, add activated composite microspheres thereto, stir at 70°C for 90 minutes, cool to room temperature, add BYK-UV 3500, photoinitiator TPO-L and Lancolu L-6314 and mix evenly.

[0045] Tinplate was used as the substrate, and the UV paint obtained in Example 5 and Comparative Example 1-2 was sprayed on the substrate surface with a spraying thickness of 25 μm; leveling treatment was performed at 40°C for 2 min, and the irradiation energy was 800 mJ / cm 2 Cured under UV light for 40 seconds and left at room temperature for 12 hours.

[0046] The hardness of the above-mentioned UV paint films was measured by GB / T 6739-2022 "Determination of paint film hardness by pencil method for paints and varnishes"; the flexibility of the above-mentioned UV paint films was measured by referring to GB / T 1731-2020 "Determination of flexibility of paint and putty films". The results are shown in Table 1.

[0047] Table 1 Hardness and flexibility of UV coatings in each group Hardness Flexibility (mm) UV paint film obtained in Example 5 4H 2 UV paint film obtained in Comparative Example 1 3H 4 UV paint film obtained in Comparative Example 2 2H 3 As can be seen from Table 1, the UV coating film obtained in Example 5 has the highest hardness and the best flexibility.

[0048] Using an SPC floor without a UV coating as the substrate, spray the UV paints obtained in Example 5 and Comparative Examples 1-2 on the surface of the substrate to a thickness of 25 μm; perform a leveling treatment at 42 °C for 3 min, and cure under ultraviolet light with an irradiation energy of 800 mJ / cm 2 for 60 s, and leave it at room temperature for 15 h.

[0049] Refer to GB / T 15036.1-2018 "Solid Wood Flooring - Part 1: Technical Requirements" to test the wear resistance of the above-mentioned UV coating films in each group; refer to GB / T 9286-2021 "Cross-Cut Test for Paints and Varnishes" to test the adhesion of the above-mentioned UV coating films in each group. The results are shown in Table 2.

[0050] Among them, the adhesion evaluation criteria are from grade 0 to grade 5, specifically as follows: Grade 0: No peeling; Grade 1: A little coating peeling, with the peeling area less than 5%; Grade 2: The peeling area is greater than 5% and less than 15%; Grade 3: The peeling area is greater than 15% and less than 35%; Grade 4: The peeling area is greater than 35% and less than 65%; Grade 5: The peeling area is greater than 65% and less than or equal to 100%.

[0051] Table 2 Wear resistance and adhesion of UV coating films in each group Abrasion resistance (g / 100r) Adhesion UV paint film obtained in Example 5 0.025, the paint film was not worn through Grade 0 UV paint film obtained in Comparative Example 1 0.081, the paint film was slightly worn through Grade 2 UV paint film obtained in Comparative Example 2 0.046, the paint film was slightly worn through Grade 1 As can be seen from Table 2, the wear resistance and adhesion of the UV coating film obtained in Example 5 are better than those of Comparative Examples 1-2.

[0052] Place the UV coating films on the surface of the above-mentioned floor substrates in environments of 80 °C and -20 °C for 72 h respectively, and evaluate according to the cracking grade in GB / T 1766-2008 "Rating Method for the Degradation of Paints and Varnishes Coatings". The results are shown in Table 3.

[0053] Table 3 Cracking grades of UV coating films in each group 80℃ -20℃ UV paint film obtained in Example 5 Crack number: Grade 0, crack size: S Grade 0 Crack number: Grade 0, crack size: S Grade 0 UV paint film obtained in Comparative Example 1 Crack number: Grade 2, crack size: S Grade 1 Crack number: Grade 1, crack size: S Grade 2 UV paint film obtained in Comparative Example 2 Crack number: Grade 1, crack size: S Grade 1 Crack number: Grade 1, crack size: S Grade 1 As can be seen from Table 3, the cracking grade of the UV coating film obtained in Example 5 is lower than that of Comparative Examples 1-2, which proves that the aging resistance of the UV coating film obtained in Example 5 is better than that of Comparative Examples 1-2.

[0054] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A UV paint for SPC floors, characterized in that, The parts by mass of its raw materials include: 50 - 100 parts of UV resin, 20 - 40 parts of 1,6 - hexanediol diacrylate, 20 - 40 parts of mixed solvent, 5 - 15 parts of polystyrene microspheres, 1 - 5 parts of tetraethyl orthosilicate, 0.1 - 1 part of sodium dodecylbenzenesulfonate, 0.1 - 1 part of silane coupling agent, 1 - 2 parts of diphenylmethane diisocyanate, 1 - 2 parts of leveling agent, 1 - 2 parts of photoinitiator, 1 - 2 parts of matting agent; The UV resin includes: polyurethane acrylate with a functionality of 2 - 3 and polyurethane acrylate with a functionality of 4 - 6.

2. The UV paint for SPC floor according to claim 1, characterized in that, The mass ratio of polyurethane acrylate to polyurethane acrylate is 5 - 10:1 - 4.

3. The UV paint for SPC floor according to claim 1, characterized in that, The leveling agent is an organosilicon leveling agent.

4. The UV paint for SPC floor according to claim 1, characterized in that, The photoinitiator is at least one of photoinitiator TPO, photoinitiator TPO - L, and photoinitiator 1173.

5. The UV paint for SPC floor according to claim 1, characterized in that, The mixed solvent includes ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol monobutyl ether.

6. The UV paint for SPC floor according to claim 5, characterized in that, The mass ratio of ethyl acetate, butyl acetate, ethylene glycol monobutyl ether, and propylene glycol monobutyl ether is 5 - 10:1 - 5:1 - 2:1 - 2.

7. The UV paint for SPC floor according to claim 1, wherein The particle size of the polystyrene microspheres is 1 - 5 μm.

8. A preparation method of the UV paint for SPC floor according to any one of claims 1-7, characterized in that, It includes the following steps: S1. Add polystyrene microspheres, tetraethyl orthosilicate, and sodium dodecylbenzenesulfonate to an ethanol aqueous solution, stir for 10 - 30 min, adjust the pH value of the system to 4 - 5, perform ultrasonic treatment for 1 - 2 h, filter by suction, wash, and dry in vacuum to obtain composite microspheres; S2. Add the composite microspheres to N,N - dimethylformamide, add KH550 coupling agent, reflux and stir at 70 - 80 °C for 1 - 2 h, add diphenylmethane diisocyanate and continue reflux and stir for 2 - 4 h, wash, filter by suction under reduced pressure, and dry in vacuum to obtain activated composite microspheres; S3. Mix the UV resin, 1,6 - hexanediol diacrylate, and mixed solvent evenly, add the activated composite microspheres thereto, stir at 60 - 80 °C for 1 - 2 h, cool to room temperature, and add the leveling agent, photoinitiator, and matting agent and mix evenly.

9. The preparation method of the UV paint for SPC floor according to claim 8, characterized in that In S1, the ultrasonic frequency is 40 - 60 kHz.

10. The preparation method of the UV paint for SPC floor according to claim 8, characterized in that, In S1, 1 - 2 mol / L hydrochloric acid is used to adjust the pH value of the system to 4 - 5.