Preparation method of UV (ultraviolet) photocureable coating environment-friendly matting powder for PVC (polyvinyl chloride) wood floor

Abstract

The invention belongs to the technical field of photocureable coatings, and particularly relates to a preparation method of UV photocureable coating environment-friendly matting powder for PVC wood floors. The preparation method comprises the following steps: S1, preparing a water glass solution and a sulfuric acid solution; s2, simultaneously injecting a water glass solution and a sulfuric acid solution into the reaction kettle to form silica sol; s3, adding caustic soda to adjust the pH value to be alkaline, adding a silane coupling agent, a performance additive and a photocatalyst according to a certain proportion, heating, boosting and aging, adjusting the pH value to be acidic, aging and washing; and S4, treating the three mixed waxes in proportion through two-stage spray drying, and performing fluid energy milling through a fluidized bed to obtain the wax. The matting powder product provided by the invention is high in matting property and excellent in viscosity control, matting property and weather resistance, the content of formaldehyde in a UV wood board is controlled to be lower than E0 level, domestic substitution is realized, and the greening process in the UV photocuring field is further accelerated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of matt coating, and particularly relates to a preparation method of an environmentally-friendly matt powder for UV light-cured coating of PVC wood floor. BACKGROUND

[0002] The UV light-cured coating has the characteristics of low curing temperature, fast curing speed, no solvent or less solvent, and no pollution, and can help enterprises save energy and improve production efficiency compared with traditional coating, so the market prospect is broad. In order to make the substrate reduce gloss to achieve a matt effect, the conventional coating needs to volatilize the solvent to form a rough surface with other components attached to the surface of the substrate, and the UV light-cured coating is not easy to shrink during the curing process due to the characteristics of no solvent or less solvent. Therefore, the particles added as matt agents in the UV coating cannot play a role, and the powder is easy to settle, producing a hard colloid, which affects the construction. At present, the silica matt powder for UV coating needs to be treated with wax to improve the anti-settling property, but the introduction of wax will make the overall viscosity of the coating high, and the improvement of the matt property is also limited, often needing other special treatment to improve the matt property.

[0003] Chinese patent CN115403955A discloses a high-matt UV light-cured coating special matt powder and a preparation method thereof, which improves the compatibility of the powder with the UV light-cured coating resin by introducing a specific acrylate monomer to treat the powder, and reduces the viscosity of the coating system by treating the powder with a defoaming agent, but the disadvantage is that the acrylate monomer is combined with the silica by a physical grafting modification method, and the stability is not high because the acrylate monomer is modified after the formation of the silica structure. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a preparation method of an environmentally-friendly matt powder for UV light-cured coating of PVC wood floor. The silica matt powder prepared by the present application has high pore volume, moderate bulk density and narrow particle size distribution. The surface of the silica is treated with a silane coupling agent, a modification aid and a photoinitiator (photocatalyst), which overcomes the defects of physical grafting modification, and the synthesized and surface-modified silica is relatively more environmentally-friendly and stable, enhances the compatibility of the powder with the UV light-cured coating resin, and improves the matt efficiency. The powder is treated with polyethylene wax to improve the anti-settling property, and has good touch and certain hydrophobicity, which is close to the performance of the Graces RAD2105 product in the application end.

[0005] The primary object of the present application is to provide a preparation method of an environmentally-friendly matt powder for UV light-cured coating of PVC wood floor. To achieve this object, the technical scheme adopted by the present application is as follows:

[0006] A preparation method of an environmentally-friendly matt powder for UV light-cured coating of PVC wood floor, comprising the following steps:

[0007] S1, configure water glass solution and sulfuric acid solution;

[0008] S2, under the condition of keeping a certain pH, inject water glass solution and sulfuric acid solution into the reaction kettle to form silica sol;

[0009] S3, add caustic soda to adjust the pH value to alkaline, then add silane coupling agent, modification aid and catalyst according to a certain proportion, and then heat and pressurize to perform aging, after aging, add sulfuric acid to adjust the pH value to acid, and then age and wash;

[0010] S4, then through two-stage spray drying, and through three kinds of mixed wax treatment, and through high-temperature airflow crushing, and then obtained.

[0011] Preferably, the modulus of the water glass in step S1 is 3.40-3.70, the silica concentration of the water glass solution is 3wt%-8wt%, and the concentration of the sulfuric acid solution is 5wt%-10wt%.

[0012] Preferably, the reaction kettle of step S2 is provided with an acid liquid injection pipe A and an alkali liquid injection pipe B, and the end of the acid liquid injection pipe A and the end of the alkali liquid injection pipe B are provided with a plurality of injection heads with injection holes; the acid liquid injection head is arranged opposite to the alkali liquid injection head; wherein the distance between the injection heads of A and B is 1-2 meters, the diameter of the injection holes is 3-5 mm, the number of the injection holes is 20-50, the flow pressure of the acid liquid injection pipe A and the alkali liquid injection pipe B is 0.2-0.3 MPa, and the pH of the acid-base reaction is kept at 1.0-3.0. Conventionally, the acid liquid injection pipe A and the alkali liquid injection pipe B are provided at their ends without the above-mentioned improvement, and the above-mentioned improvement of the present application can better realize the reaction collision of the acid-base pipe liquid.

[0013] Preferably, the silane coupling agent added in step S3 is one or more of 3-(methacryloyloxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and 3-aminopropyltriethoxysilane. The catalyst comprises a modification aid and a photocatalyst, the modification aid is one or more of polydimethylsiloxane (PDMS), dipentaerythritol pentaacrylate (DPPA), trimethylolpropane triacrylate (TMPTA), and polyurethane acrylate, the photocatalyst is a nano-TiO2 dispersion liquid, and the ratio of the silane coupling agent to the modification aid and the TiO2 dispersion liquid is (1-2):(2-3):1, and the total amount of the three substances is 1-2% of the total content of silicon dioxide.

[0014] Preferably, the temperature of the heat aging in step S3 is 120-150℃, the pressure is 0.5-0.8 MPa, the aging pH is 9-11, and after aging, the acidification pH is 2-4.

[0015] Preferably, the two-stage spray drying of step S4, wherein the inlet temperature of the first-stage spray drying is 120-150 DEG C, the outlet temperature is 90-100 DEG C, the spray drying time is 10-30 S, the inlet temperature of the second-stage spray drying is 500-600 DEG C, the outlet temperature is 120-150 DEG C, and the spray drying time is 1-5 S; and the heating temperature of the fluidized bed jet mill is 250-350 DEG C.

[0016] Preferably, the three kinds of mixed waxes in step S4 are polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702, and the mixing ratio is (1-3):(1-2):1.

[0017] The silica synthesized in the application has large pore volume, concentrated particle size distribution and good surface treatment effect, and has good dispersibility and extinction efficiency, and in the UV photocuring system, has good anti-settling property, low viscosity, good touch and other characteristics, and the application test is close to the performance of Grace RAD2105, and the titanium catalyst can oxidize formaldehyde to a certain extent, and accelerate the green and environmental protection process in the UV field.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] 1. The UV photocuring coating environmental protection type extinction powder for PVC wood floor provided by the application, the silane coupling agent in step S3 can improve the compatibility of the silica powder with the UV photocuring coating resin and the modified additive, the extinction powder system is well dispersed in the UV curing process, the powder system shrinks slowly, the extinction efficiency is improved, the modified additive can improve the three-dimensional network structure of the UV photocuring high cross-linking density in the PVC wood floor, so that the coating has higher hardness and is more dense; on the other hand, the photocatalyst nano titanium dioxide can catalyze the formaldehyde in the PVC floor to a certain extent, so that the UV photocuring coating is further environmental protection, and the addition proportion of the photocatalyst is small enough to prevent the photocatalyst from accelerating the aging and decomposition of the PVC coating and reducing the coating film performance.

[0020] 2. The high-temperature fluidized bed is used to heat and dissolve the waxes in the application, and then the waxes are uniformly treated on the surface of the silica, wherein the heating temperature is about 250-350 DEG C, the polyethylene wax can make the system have good hand feeling, the polyamide wax can improve the anti-settling property of the UV coating system, the polytetrafluoroethylene wax can improve the scratch resistance of the UV coating, and the total amount of the three substances is 8-15% of the total content of the silica, so that the high wax content can reduce the viscosity of the coating system and facilitate construction. The problems of difficult extinction of the current UV photocuring coating and high pore volume silica extinction powder that makes the system viscosity too high and difficult to construct can be solved, and the hand feeling and scratch resistance of the UV system can be improved.

[0021] 3、The washing method of the present application adopts 40-70℃ hot pure water, 0.1-0.5% aqueous solution of ammonium salt, 40-70℃ hot pure water, and the washing sequence time interval is 2:5:3, respectively. The hot water and ammonium salt can quickly wash away Na + and SO4 -2 ions in the solution without destroying the pore volume of the silicon dioxide, thereby reducing the system conductivity. In addition, the ammonium salt can penetrate into the pore channel of the silicon dioxide particles during washing and volatilize during the subsequent drying process, thereby playing the role of pore expansion.

[0022] 4、The present application adopts two-stage spray drying equipment for drying, the inlet temperature of the first-stage spray drying is 120~150℃, the outlet temperature is 90~100℃, the spray drying time is 10~30S, the inlet temperature of the second-stage spray drying is 500~600℃, the outlet temperature is 120~150℃, and the spray drying time is 1~5S. The drying method can maintain the state of the pore structure of the silicon dioxide to a certain extent by the first-stage spray drying temperature, and can ensure that the moisture content of the silicon dioxide reaches the requirement by the second-stage spray drying temperature, and the short-time high-temperature condition can ensure that the skeleton structure of the silicon dioxide powder does not change. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 HU65 is the existing product;

[0024] Figure 2 HU70 is the existing product. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described clearly and completely below by combining the examples and comparative examples of the present application. Obviously, the described examples are only some of the examples of the present application, but not all the examples. Based on the examples in the present application, all the other examples obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0026] The test methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used are commercially available reagents and materials unless otherwise specified. The parts in the following examples are all in grams.

[0027] Example 1

[0028] The temperature is kept at 50℃, and 3wt% water glass solution and 5wt% sulfuric acid solution are respectively passed through the reaction kettle with a pressure of 0.2Mpa. The reaction kettle is provided with acid liquid injection pipe A and alkali liquid injection pipe B, and the end of the acid liquid injection pipe A and the end of the alkali liquid injection pipe B are provided with a plurality of injection holes of the injection head. The acid liquid injection head and the alkali liquid injection head are arranged opposite to each other (for making the sprayed acid liquid flow and the alkali liquid flow react with each other in the reaction kettle (container), but the connecting lines of the acid liquid and the alkali liquid are kept at a proper distance from the stirring paddle of the reaction kettle to prevent affecting the acid-base reaction), the acid and the alkali instantaneously contact to form a very small primary structure of silicon dioxide to ensure that the primary particles are as small as possible to reduce agglomeration; wherein the distance between the injection heads of A and B is 2 meters, the diameter of the injection holes is 5mm, the number of the injection holes is 20, the flow pressure of the acid and alkali pipes is 0.3MPa, and the pH of the acid-base reaction is kept at 1.0 to form the silica sol; then the pH is adjusted to 9 by adding caustic soda, and then a dispersion liquid of silane coupling agent 3-(methacryloyloxy)propyl trimethoxysilane, modified auxiliary polydimethylsiloxane and photocatalyst TiO2 is added, and the mass ratio of the three is 1:2:1, and the total amount of the three substances is 1% of the total content of silicon dioxide.

[0029] The temperature is raised to 120℃, the pressure is 0.5Mpa, and the reaction is aged for 120 minutes under the pH condition. The pressure of the reaction kettle is reduced to normal pressure, and then pure water is added to cool to 70℃. Then, under the temperature condition, sulfuric acid is added to adjust the pH to 2.0 and aged for 20 minutes. After aging, the pressure filter frame is pumped in, and the water is washed according to the washing sequence time interval of 2:5:3 with 0.1% ammonium salt aqueous solution at 40℃ hot pure water, 40℃ hot pure water, and the water washing time is 6 hours. The water washing is stopped when the conductivity is below 150us / cm. After washing, drying is carried out by two-stage spray equipment, wherein the inlet temperature of the first-stage spray drying is 120℃, the outlet temperature is 90-92℃, the spray drying time is 30S, the inlet temperature of the second-stage spray drying is 500℃, the outlet temperature is 120-125℃, and the spray drying time is 5S. Then, wax surface treatment is carried out: the wax is a mixture of polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702 in a mass ratio of 1:1:1, and the total amount of the three substances is 8% of the total content of silicon dioxide. Then, the fluidized bed jet mill with a heating temperature of 250℃ is used for crushing, and the crushing particle size is 6.0-7.0um. Thus, the product is obtained.

[0030] The product physical and chemical property test method and standard are as follows:

[0031] (1) Pore volume test: full-automatic specific surface area and pore volume analyzer Mac TriStar II 3020;

[0032] (2) Bulk density test: according to the test scheme of GB / T 16913-2008, the bulk density instrument is used for detection;

[0033] (3) Ignition loss test: after drying the moisture, 1000℃ high temperature furnace is ignited until the mass is constant, and the difference before and after is calculated;

[0034] (4) Titanium element content test: inductively coupled plasma optical emission spectrometry (ICP-OES);

[0035] (5) Average particle size and D100 particle size: Malvern 3000 laser particle size analyzer;

[0036] The physical and chemical properties of the seven parallel products are shown in Table 1.

[0037] Table 1

[0038] Example 2

[0039] A preparation method of an environmentally friendly matt powder for a UV light-cured coating for a PVC wood floor, comprising the following steps:

[0040] The temperature is kept at 80℃, and 8wt% water glass solution and 10wt% sulfuric acid solution are respectively passed through the reaction kettle with a pressure of 0.3Mpa. The reaction kettle is provided with acid liquid injection pipe A and alkali liquid injection pipe B, and the end of the acid liquid injection pipe A and the end of the alkali liquid injection pipe B are provided with a plurality of injection holes of the injection head. The acid liquid injection head and the alkali liquid injection head are arranged opposite to each other (for making the sprayed acid liquid flow and the alkali liquid flow react with each other in the reaction kettle (container), but the connecting lines of the acid liquid and the alkali liquid are kept at a proper distance from the stirring paddle of the reaction kettle to prevent affecting the acid-base reaction), the acid and the alkali instantaneously contact to form a very small primary structure of silicon dioxide to ensure that the primary particles are as small as possible to reduce agglomeration; wherein the distance between the injection heads of A and B is 2 meters, the diameter of the injection holes is 5mm, the number of the injection holes is 50, the flow pressure of the acid and alkali pipes is 0.3MPa, and the pH of the acid-base reaction is kept at 3.0 to form the silica sol; then the pH is adjusted to 11 by adding caustic soda, and then a dispersion liquid of silane coupling agent 3-(methacryloyloxy)propyl trimethoxysilane, modification aid dipentaerythritol pentaacrylate and photocatalyst TiO2 is added, and the mass ratio of the three is 1:3:1, and the total amount of the three substances is 2% of the total content of silicon dioxide; then the temperature is raised to 150℃ and the pressure is 1.0Mpa, and the reaction is aged for 90 minutes under the pH condition; the pressure of the reaction kettle is reduced to normal pressure, and then pure water is added to cool to 90℃; then sulfuric acid is added to adjust the pH to 5.0 under the temperature condition, and the product is aged for 60 minutes; after aging, the product is washed by suction filtration plate frame with 70℃ hot pure water, 0.5% aqueous solution of ammonium salt, and 70℃ hot pure water in the order of 2:5:3, and the water washing time is 3 hours; the water washing is stopped when the conductivity is less than 150us / cm; after washing, the product is dried by two-stage spray equipment, wherein the inlet temperature of the first-stage spray drying is 150℃, the outlet temperature is 98-100℃, the spray drying time is 10S, the inlet temperature of the second-stage spray drying is 600℃, the outlet temperature is 145-150℃, and the spray drying time is 1S; then the product is treated by wax surface treatment: the wax is a mixture of polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702 in a mass ratio of 1:2:1, and the total amount of the three substances is 15% of the total content of silicon dioxide; then the product is crushed by a fluidized bed jet mill with a heating temperature of 350℃, and the crushed particle size is 6.0-7.0um.

[0041] Example 3

[0042] A preparation method of an environmentally friendly matt powder for a UV light-cured coating for PVC wood flooring, comprising the following steps:

[0043] Under the condition of 60℃, 5wt% water glass solution and 7wt% sulfuric acid solution are respectively passed through the reaction kettle with pressure of 0.25Mpa, the reaction kettle is provided with acid liquid injection pipe A and alkali liquid injection pipe B, and the end of acid liquid injection pipe A and alkali liquid injection pipe B is provided with a plurality of injection holes of injection head; the acid liquid injection head and the alkali liquid injection head are oppositely arranged (for making the sprayed acid liquid flow and the alkali liquid flow react with each other in the reaction kettle (container), but the connecting line of the acid liquid and the alkali liquid keeps proper distance from the stirring paddle of the reaction kettle, so as to prevent affecting the acid-base reaction), the acid and the alkali instantaneously contact to form extremely small primary structure of silicon dioxide, so as to ensure that the primary particles as much as possible reduce agglomeration; wherein, the distance between the injection heads of A and B is 2 meters, the diameter of the injection holes is 5mm, the number of the injection holes is 50, the flow pressure of the acid and alkali pipes is 0.3MPa, and the pH of the acid-base reaction is kept at 1.0 to form the silica sol; then, the pH is adjusted to 10 by adding caustic soda, and then a dispersion liquid of silane coupling agent 3-(2,3-epoxypropoxy) propyl trimethoxysilane, modified auxiliary trimethylolpropane triacrylate and photocatalyst TiO2 is added, the mass ratio of the three is 2:2:1, and the total amount of the three substances is 1.5% of the total content of silicon dioxide; then, the temperature is increased to 130℃, the pressure is 0.7Mpa, the reaction is aged for 100 minutes under the pH condition, the pressure of the reaction kettle is reduced to normal pressure, then pure water is added to cool to 80℃, then sulfuric acid is added to adjust the pH to 3.0 under the temperature condition, and the aging is performed for 30 minutes; after the aging is completed, the pressure filter plate frame is extracted, and the washing is performed in the order of 50℃ hot pure water, 0.3% aqueous solution of ammonium salt, and 50℃ hot pure water with time interval of 2:5:3, the water washing time is 4 hours, the water washing is performed until the conductivity is less than 150us / cm, then the drying is performed through two-stage spraying equipment, wherein the inlet temperature of the first-stage spraying drying is 130℃, the outlet temperature is 93-95℃, the spraying drying time is 15S, the inlet temperature of the second-stage spraying drying is 550℃, the outlet temperature is 135-140℃, and the spraying drying time is 3S; then, wax surface treatment is performed, the wax is polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702 mixed in the ratio of 2:1:1, the total amount of the three substances is 13% of the total content of silicon dioxide, then the fluidized bed jet mill with heating temperature of 300℃ is used for crushing, the crushing particle size is 6.0-7.0um, and the UV photocuring coating for PVC wood floor is obtained.

[0044] Example 4

[0045] A preparation method of an environmentally friendly matt powder of a UV photocuring coating for PVC wood floor, comprising the following steps:

[0046] Under the condition of 70℃, 6wt% water glass solution and 8wt% sulfuric acid solution are respectively passed through the reactor with pressure of 0.26Mpa, the reactor is provided with acid liquid injection pipe A and alkali liquid injection pipe B, and the end of acid liquid injection pipe A and alkali liquid injection pipe B is provided with a plurality of injection holes of injection head; the acid liquid injection head and the alkali liquid injection head are oppositely arranged (for making the sprayed acid liquid flow and the alkali liquid flow react with each other in the reactor (container), but the connecting line of the acid liquid and the alkali liquid keeps proper distance from the stirring paddle of the reactor, so as to prevent affecting the acid-base reaction), the acid and the alkali instantaneously contact to form extremely small primary structure of silicon dioxide, so as to ensure that the primary particles as much as possible reduce agglomeration; wherein, the distance between the injection heads of A and B is 2 meters, the diameter of the injection holes is 5mm, the number of the injection holes is 50, the flow pressure of the acid and alkali pipes is 0.3MPa, and the pH of the acid-base reaction is kept at 1.0 to form the silica sol; then, the pH is adjusted to 10 by adding caustic soda, and then a dispersion liquid of silane coupling agent 3-aminopropyl triethoxysilane, modified auxiliary polydimethylsiloxane and photocatalyst TiO2 is added, the mass ratio of the three is 2:3:1, and the total amount of the three substances is 1.2% of the total content of silicon dioxide; then, the temperature is increased to 140℃, the pressure is 0.8Mpa, and the reaction is aged for 100 minutes under the pH condition; then, the pressure of the reactor is reduced to normal pressure, and then pure water is added to cool to 75℃; then, sulfuric acid is added to adjust the pH to 4.0 under the temperature condition, and then the aging is performed for 30 minutes; after the aging is completed, the pressure filter frame is extracted, and then hot pure water, 0.2% aqueous solution of ammonium salt and hot pure water at 60℃ are sequentially washed in the order of time interval of 2:5:3, the water washing time is 5 hours, the water washing is performed until the conductivity is less than 150us / cm, and then the washing is completed; then, drying is performed through two-stage spray equipment, wherein the inlet temperature of the first-stage spray drying is 140℃, the outlet temperature is 96-98℃, the spray drying time is 15S, the inlet temperature of the second-stage spray drying is 530℃, the outlet temperature is 130-135℃, the spray drying time is 4S, and then wax surface treatment is performed; the wax is a mixture of polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702 according to the ratio of 2:2:1, the total amount of the three substances is 10% of the total content of silicon dioxide, then the fluidized bed jet mill with heating temperature of 280℃ is used for crushing, the crushing particle size is 6.0-7.0um, and then the product is obtained.

[0047] Example 5

[0048] A preparation method of an environmentally friendly matt powder of a UV photocuring coating for PVC wood floor, comprising the following steps:

[0049] In the reaction kettle with two rows of fine holes, keep the temperature at 65℃, 4wt% water glass solution and 6wt% sulfuric acid solution are respectively passed through the reaction kettle with pressure of 0.22Mpa, the reaction kettle is provided with acid liquid injection pipe A and alkali liquid injection pipe B, and the end of acid liquid injection pipe A and alkali liquid injection pipe B is provided with a plurality of injection holes of injection head; the acid liquid injection head is arranged opposite to the alkali liquid injection head (for making the sprayed acid liquid flow and alkali liquid flow react with each other in the reaction kettle (container), but the connecting line of acid liquid and alkali liquid keeps proper distance from the stirring paddle of the reaction kettle, so as to prevent affecting the acid-base reaction), the acid and alkali instantaneously contact to form extremely small primary structure of silicon dioxide, so as to ensure that the primary particles as much as possible reduce agglomeration; wherein, the distance between the injection heads of A and B is 2 meters, the diameter of the injection holes is 5mm, the number of the injection holes is 50, the flow pressure of the acid and alkali pipes is 0.3MPa, and the pH of the acid-base reaction is kept at 1.0 to form the silica sol; then, the pH is adjusted to 9.5 by adding caustic soda, and then the dispersion liquid of silane coupling agent 3-(2,3-epoxypropoxy) propyl trimethoxysilane, modified auxiliary polyurethane acrylate and photocatalyst TiO2 is added, the mass ratio of the three is 1:2:1, and the total amount of the three substances is 1.4% of the total content of silicon dioxide; then, the temperature is raised to 135℃, the pressure is 0.75Mpa, the reaction is aged for 105 minutes under the pH condition, the pressure of the reaction kettle is reduced to normal pressure, then pure water is added to cool to 85℃, then sulfuric acid is added to adjust the pH to 3.5 under the temperature condition, and the aging is carried out for 40 minutes, after the aging is completed, the pressure filter plate frame is extracted, and hot pure water, 0.4% ammonium salt aqueous solution and hot pure water at 55℃ are used for washing in the order of time interval of 2:5:3, the water washing time is 4.5 hours, the water washing is carried out until the conductivity is less than 150us / cm, after the washing is completed, drying is carried out through two-stage spraying equipment, wherein the inlet temperature of the first-stage spraying drying is 135℃, the outlet temperature is 94-96℃, the spraying drying time is 15S, the inlet temperature of the second-stage spraying drying is 570℃, the outlet temperature is 140-145℃, and the spraying drying time is 2S, then wax surface treatment is carried out, the wax is polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702 mixed according to the ratio of 3:1:1, the total amount of the three substances is 11% of the total content of silicon dioxide, then the fluidized bed jet mill is used for crushing at heating temperature of 320℃, the crushing particle size is 6.0-7.0um, and the PVC wood floor UV photocuring coating environment-friendly matt powder is obtained.

[0050] Example 6

[0051] A preparation method of a PVC wood floor UV photocuring coating environment-friendly matt powder, comprising the following steps:

[0052] At a temperature of 75°C, 7wt% water glass solution and 9wt% sulfuric acid solution were respectively passed through a reactor with a pressure of 0.28Mpa, the reactor was provided with an acid liquid injection pipe A and a lye injection pipe B, and the end of the acid liquid injection pipe A and the lye injection pipe B were provided with a plurality of injection holes of the injection head; the acid liquid injection head and the lye injection head were arranged opposite to each other (for making the sprayed acid liquid flow and the lye flow react with each other in the reactor (container), but the connecting lines of the acid and the lye kept a proper distance from the stirring paddle of the reactor, so as to prevent affecting the acid-base reaction), the acid and the lye were instantaneously contacted to form a very small primary structure of silicon dioxide, so as to ensure that the primary particles as much as possible to reduce the agglomeration; wherein the distance between the injection heads of A and B was 2 meters, the diameter of the injection holes was 5mm, the number of the injection holes was 50, the flow pressure of the acid and lye pipe was 0.3MPa, and the pH of the acid-base reaction was kept at 1.0 to form the silica sol; then the pH was adjusted to 10.5 by adding caustic soda, and then a dispersion liquid of silane coupling agent 3-(methacryloyloxy)propyl trimethoxysilane, modification aid trimethylolpropane triacrylate and photocatalyst TiO2 was added, the mass ratio of the three was 2:2:1, and the total amount of the three substances was 1.8% of the total content of silicon dioxide; then the temperature was raised to 145°C and the pressure was 0.8Mpa, the reaction was aged for 100 minutes under the pH condition, the pressure of the reactor was reduced to normal pressure, then pure water was added to cool to 80°C, then sulfuric acid was added to adjust the pH to 3.0 at the temperature condition, and the aging was carried out for 30 minutes; after the aging was completed, the pressure filter plate frame was extracted, and hot pure water, 0.3% ammonium salt aqueous solution and hot pure water at 60°C were used for washing in the order of 2:5:3 with time intervals, the water washing time was 4 hours, the water washing was stopped when the conductivity was less than 150us / cm, and then drying was carried out through two-stage spray equipment, wherein the inlet temperature of the first-stage spray drying was 145°C, the outlet temperature was 97-99°C, the spray drying time was 12S, the inlet temperature of the second-stage spray drying was 580°C, the outlet temperature was 140-145°C, and the spray drying time was 2S; then wax surface treatment was carried out, the wax was a mixture of polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401 and polytetrafluoroethylene wax Honeywell A-C6702 in a mass ratio of 3:2:1, the total amount of the three substances was 12.5% of the total content of silicon dioxide, and then the fluidized bed jet mill was used for crushing at a heating temperature of 330°C, the crushing particle size was 6.0-7.0um, and the product was obtained.

[0053] Comparative Example 1.

[0054] Compared with Example 1, the difference lies in that the silane coupling agent 3-(methacryloyloxy)propyl trimethoxysilane, dipentaerythritol pentaacrylate and photocatalyst TiO2 are not added, and the other operations are the same as those of Example 1.

[0055] Comparative Example 2

[0056] The difference compared with Example 1 is that the proportion of the dispersion of the silane coupling agent 3-(methacryloyloxy)propyl trimethoxysilane, dipentaerythritol pentaacrylate and the photocatalyst TiO2 is 3:4:1 instead of 1:2:1, and other operations are the same as those in Example 1.

[0057] Comparative Example 3

[0058] The difference compared with Example 1 is that the total amount of the silane coupling agent, the modification aid and the photocatalyst exceeds 1-2% of the total content of the silica, and the amount added is 3% of the total content of the silica, and other operations are the same as those in Example 1.

[0059] Comparative Example 4

[0060] The difference compared with Example 1 is that after the aging is completed, the filter frame is washed with normal temperature water for 6 hours, and the hot pure water at 40-70℃, the 0.1-0.5% ammonia salt aqueous solution, the hot pure water at 40-70℃ are not used, and the washing sequence and time interval are 2:5:3, respectively, and other operations are the same as those in Example 1.

[0061] Comparative Example 5

[0062] The difference compared with Example 1 is that after the washing is completed, the two-stage spray drying equipment is not used for drying, and an imported spray dryer with an inlet temperature of 400-500℃ and an outlet temperature of 105-125℃ is directly used for drying, and other operations are the same as those in Example 1.

[0063] Comparative Example 6

[0064] The difference compared with Example 1 is that after the three kinds of wax surface treatment, the fluidized bed airflow pulverizer with a heating temperature of 250-350℃ is not used for pulverization, but a conventional fluidized bed airflow pulverizer with a heating temperature of 100℃ is used for pulverization, and other operations are the same as those in Example 1.

[0065] Comparative Example 7

[0066] The difference compared with Example 1 is that in the wax surface treatment, the polyethylene wax Honeywell A-C6, the polyamide wax Honeywell A-C6401 and the polytetrafluoroethylene wax Honeywell A-C6702 are not added according to the ratio of (1-2):(2-3):1, but only the polyethylene wax is added, and the amount added is unchanged, and other operations are the same as those in Example 1.

[0067] The product physical property test method and standard are the same as those in Example 1, and the physical properties of the seven parallel products are shown in Table 2.

[0068] Table 2

[0069] Result analysis

[0070] The detection data of Comparative Example 1 and the above five examples can be seen that the product produced according to the technical solution of the application is basically close in the physical and chemical indexes, indicating that the technical solution is stable in production.

[0071] From Comparative Examples 1 and 2, it can be seen that, without adding the silane coupling agent, the modification aid and TiO2, and other conditions being unchanged, the pore volume of the product of Comparative Example 1 increases and the bulk density decreases. The reason is that, after the treatment of the silane coupling agent, the modification aid and TiO2, the hydroxyl groups on the surface of the structure of the silica are replaced by the organic functional groups, the dispersibility of the primary silica is improved, the pore volume increases, the modification aid and TiO2 enter the pore, the pore volume of the silica particles decreases, and the bulk density increases. On the contrary, without adding the three aids, the pore volume increases and the bulk density becomes stronger, and the product does not contain titanium element. In Comparative Example 2, the amount of the three aids is changed, and the bulk density and the pore volume are within the index range of the examples, but the content of the titanium element is slightly lower than that of the examples.

[0072] From Comparative Example 3, it can be seen that, when the total amount of the silane coupling agent, the modification aid and the photocatalyst accounts for 3% of the total content of the silica, which exceeds 2% of the total content of the silica, and other conditions being unchanged, the pore volume of the product decreases, and the bulk density, the loss on ignition and the titanium content increase. The reason is that the content of the added aids is too high, which causes some aid molecules to enter the pore structure of the silica, weakens the steric hindrance effect caused by the modification, and prevents the further growth of the pore volume, so that the overall pore volume decreases, and the bulk density, the loss on ignition and the titanium content increase.

[0073] From Comparative Example 4, it can be seen that, when the silica is washed with normal temperature water, and not washed with 40-70℃ hot pure water, 0.1-0.5% aqueous solution of ammonium salt and 40-70℃ hot pure water according to the washing sequence and time interval of 2:5:3, and other conditions being unchanged, the pore volume of the product decreases. The reason is that the washing method of using hot pure water, ammonium salt solution and hot pure water can accelerate the rapid separation of sodium sulfate salt in the silica structure, and the ammonium salt can enter the pore structure of the silica, and then be decomposed and volatilized in the subsequent high-temperature drying process, so that the pore volume is expanded and the bulk density is decreased.

[0074] By Comparative Example 5, it can be concluded that, without using two-stage spray drying equipment, directly using spray drying equipment with an inlet temperature of 400-500°C and an outlet temperature of 105-125°C, and with other conditions unchanged, the pore volume of the product decreases significantly, the bulk density increases, and other indicators remain basically unchanged. The primary spray drying temperature can maintain the state of the pore structure of the silicon dioxide to a certain extent, and the secondary high-temperature spray drying can reduce the moisture in the silicon dioxide. If the inlet temperature is too high and the continuous spray drying time is long, the rapid removal of adsorbed water and hydroxyl water inside the powder will accelerate, resulting in a pressure difference inside the particles, and the rich pore structure will be squeezed and collapsed, leading to a decrease in pore volume.

[0075] By Comparative Example 6, it can be concluded that, without using a fluidized bed jet mill with a heating temperature of 250-350°C for crushing, but using conventional temperature crushing, and with other conditions unchanged, the product's pore volume increases, the bulk density decreases, the D100 particle size increases, and the particle size distribution widens. The reason is that at room temperature, the wax cannot melt into the pore volume of the silicon dioxide, but only mechanically breaks the D50 particle size to the range, and the broken particles are not uniform in size, resulting in a wider particle size distribution. Figure 1 and Figure 2 From the two graphs, Figure 1 HU65 product of our company, i.e., using a 250-350°C fluidized bed jet mill to crush the sample, Figure 2 HU70 product of our company, using conventional temperature crushing of the sample. From the data, it can be concluded that the product distribution of conventional crushing is narrower.

[0076] By Comparative Example 7, it can be concluded that the structure of the silicon dioxide treated with a single wax powder has no difference from the example, and the main reason is that the wax can meet the process conditions of the example, but the subsequent application performance is significantly different from the example, as shown in Table 4 Comparative Example 7. Due to the significant difference in application performance of the three waxes in the system, a single polyethylene wax has good anti-settling properties, while polyamide wax and polytetrafluoroethylene wax can provide good scratch resistance and defoaming properties.

[0077] Application Performance Test

[0078] 1. Application Performance Test Formula: The test formula for the UV light-cured coating environmental protection type matt powder for PVC wood floor testing is as follows in Table 3:

[0079] Table 3

[0080] 2. Application Performance Test Steps:

[0081] (1) Prepare the coating: prepare the UV light oil according to the scheme, and prepare the UV light-cured coating according to the mass ratio of UV light oil:matt powder of 88:12;

[0082] (2) Dispersion treatment: the prepared UV light curing paint is dispersed in a dispersion machine at a speed of 1200-1500 rpm for 15 minutes;

[0083] (3) Viscosity test: the dispersed paint is treated in a water bath to a temperature of 25°C, and then the product viscosity is tested by a rotor viscometer;

[0084] (4) Gloss test and other tests: the dispersed paint is added to a UV roller coater, the parameters and the position of the bottom plate are adjusted, the UV bottom plate coating amount is 6-8 g / m 2 over the lamp, and then the bottom plate gloss is tested by a gloss meter, and other properties of the bottom plate are tested.

[0085] 3. Application test of the experimental product:

[0086] The six product examples 1, 3, 5 of the present application and the comparative product examples 2, 4, 6, as well as the Graces RAD2105 and the blank control sample without extinction powder, are compared in terms of the application of the UV light curing paint environment-friendly extinction powder, and the results of the physical and chemical indexes and application tests are shown in Table 4:

[0087] Test methods and standards for the physical and chemical properties and application of the product:

[0088] (1) Gloss test: using a scale instrument BGD516 / 3 to test at an incident angle of 60°;

[0089] (2) Viscosity test: using a rotary viscometer NDJ-5S with a 2# rotor to test the paint viscosity at 25°C;

[0090] (3) Scratch resistance test: according to the EN 13329 standard to divide the grades;

[0091] (4) Anti-settling test: the dispersed UV light curing paint is filled into a paint can, and after 48 hours, the volume height of the precipitate is observed, and the standard solution is 20 cm;

[0092] (5) Weather resistance test: after irradiation for 72 hours using a UV fluorescent lamp aging test box, the surface condition of the plate is observed;

[0093] (6) Defoaming test: the coated plate is heated, and after the temperature reaches 50°C, the heating is stopped, and after 2 hours, the surface condition of the plate is observed;

[0094] (7) Formaldehyde content test: according to GB 18580-2025, using a 1 m 3 climate chamber method for testing.

[0095] Table 4

[0096] Note: the larger the value, the better, with 10 being the best. The larger the anti-settling number, the softer the sediment; the larger the weather resistance number, the better the stability; the larger the defoaming number, the better the additivity;

[0097] 4. Experimental Conclusion

[0098] Based on the data in Table 2 and Table 4, it can be concluded that the physical and chemical indicators of each example change little, the application situation fluctuates within the allowable range, and the scheme is basically stable. In Comparative Example 2, the addition ratio of silane coupling agent, modification aid and TiO2 is changed, and in the case of increasing the content of silane coupling agent and modification aid, the titanium content decreases overall, the UV application causes slight poor weather resistance, extinction, and increased formaldehyde content. In Comparative Example 4, under the condition of using normal temperature water washing for 6 hours, the sample hole volume decreases, the bulk density increases, the UV application test shows that the gloss increases, the extinction becomes worse, the viscosity decreases significantly, but the anti-settling property becomes worse; in Comparative Example 6, high-temperature crushing is not used, so that the D100 of the comparative example is larger, the uniformity of the particle size is not enough, the viscosity of the UV application is higher than that of the examples, thereby causing poor weather resistance and defoaming property, and the other performance differences are not large. As shown in Table 4, Comparative Example 7, it can be concluded that the application performance of the single wax powder treated silicon dioxide is quite different from that of the examples. As shown in Table 4, Comparative Example 7, because the application performance of the three waxes in the system is quite different, the single polyethylene wax has good anti-settling property, while the polyamide wax and the polytetrafluoroethylene wax can provide good scratch resistance and defoaming property.

[0099] The physical and chemical indicators of the UV light-cured coating environmentally friendly extinction powder example synthesized by the method are roughly close to those of the competitive product Grace RAD2105. In terms of application performance test, the test sample has stronger extinction, lower formaldehyde content, slightly higher viscosity, and basically similar scratch resistance, anti-settling property, weather resistance and defoaming property compared with the competitive product. Overall, the product performance is close to that of the competitive product Grace RAD2105, and is more environmentally friendly than the competitive product, has lower formaldehyde content when applied to wood floor, and can be applied to the promotion of UV field greenization.

[0100] The above are only some experimental data, but the specific implementation of the present application cannot be limited to these examples and these application tests. Obviously, the above examples of the present application are only examples for clearly illustrating the technical solutions of the present application, and are not a limitation on the specific implementation of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the claims of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for preparing an environmentally friendly matt powder for a UV light-cured coating for PVC wood flooring, characterized by, It comprises the following steps: S1, configure water glass solution and sulfuric acid solution; S2, under the condition of keeping a certain pH, inject water glass solution and sulfuric acid solution into the reaction kettle to form silica sol; S3, add caustic soda to adjust the pH value to alkaline, then add silane coupling agent, modification aid and catalyst in proportion, and then heat and pressurize to perform aging, after the aging is completed, add sulfuric acid to adjust the pH value to acid, age, and wash; S4, dry through two-stage spray drying, and then treat with three kinds of mixed wax, and then perform airflow pulverization to obtain the product.

2. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder according to claim 1, characterized in that, The modulus of the water glass in step S1 is 3.40-3.70, the concentration of silicon dioxide in the water glass solution is 3wt%-8wt%, and the concentration of the sulfuric acid solution is 5wt%-10wt%.

3. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder according to claim 1, characterized in that, The reaction kettle in step S2 is provided with an acid liquid injection pipe A and an alkali liquid injection pipe B, and the end of each of the acid liquid injection pipe A and the alkali liquid injection pipe B is provided with a plurality of injection holes of an injection head; the acid liquid injection head and the alkali liquid injection head are arranged opposite to each other; wherein the distance between the injection heads of A and B is 1-2 meters, the diameter of the injection holes is 3-5 mm, the number of the injection holes is 20-50, the flow pressure of the acid liquid injection pipe A and the alkali liquid injection pipe B is 0.2-0.3 MPa, and the pH of the acid-base reaction is kept at 1.0-3.

0.

4. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder according to claim 1, characterized in that, The coupling agent of the silane coupling agent added in step S3 is 3-(methacryloyloxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, or 3-aminopropyltriethoxysilane, the modification aid is polydimethylsiloxane, dipentaerythritol pentaacrylate, trimethylolpropane triacrylate, or polyurethane acrylate, the photocatalyst is a nano TiO2 dispersion liquid, and the proportion of the silane coupling agent, the modification aid and the TiO2 dispersion liquid is (1-2):(2-3):1, and the total amount of the three substances accounts for 1%-2% of the total content of silicon dioxide.

5. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder according to claim 1, characterized in that, In step S3, the temperature and pressure of the aging are 120-150℃ and 0.5-0.8 MPa respectively, the pH of the aging is 9-11, and after the aging is completed, the pH of the acidification is 2-4.

6. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder according to claim 1, characterized in that, In step S4, the drying is performed through two-stage spray equipment, wherein the inlet temperature of the first-stage spray drying is 120-150℃, the outlet temperature is 90-100℃, the spray drying time is 10-30S, the inlet temperature of the second-stage spray drying is 500-600℃, the outlet temperature is 120-150℃, and the spray drying time is 1-5S.

7. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder of claim 1, characterized in that, In the wax surface treatment in step S4, the wax is polyethylene wax Honeywell A-C6, polyamide wax Honeywell A-C6401, and polytetrafluoroethylene wax Honeywell A-C6702, and the wax is mixed in the proportion of (1-3):(1-2):1 in sequence, and the total amount of the three kinds of wax accounts for 8%-15% of the total content of silicon dioxide.

8. The preparation method of the PVC wood floor UV photocuring coating environment-friendly matt powder according to claim 1, characterized in that, In step S4, the heating temperature of the fluidized airflow pulverization is 250-350℃.

9. The environmentally friendly matt powder of the UV light-cured coating for PVC wood floor prepared by the method of any one of claims 1-8, characterized in that, The pore volume of the matting powder is 1.50 cm 3 / g~1.80 cm 3 / g, the bulk density is 0.20 g / cm 3 ~0.25 g / cm 3 , the ignition loss is 12~18%, the titanium element content is 0.15~0.50%, the D50 particle size is 6.0~7.0 microns, and the D100 particle size is ≤18 microns.

10. The use of the matt powder in claim 9 in the preparation of a UV photocuring coating for PVC wood floor.

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