Low-VOC (volatile organic compound) wood lacquer and preparation method thereof

Abstract

The invention relates to the field of wood lacquer, in particular to low-VOC wood lacquer and a preparation method thereof. The wood lacquer is prepared from the following raw materials in parts by weight: 40 to 60 parts of acrylic emulsion, 10 to 20 parts of polyurethane emulsion, 2 to 3 parts of cosolvent, 2 to 5 parts of coalescing agent, 15 to 25 parts of titanium dioxide, 0.5 to 1 part of flatting agent A, 0.5 to 1 part of thickening agent, 0.1 to 0.5 part of defoaming agent, 0.1 to 0.3 part of defoaming agent, 0.1 to 1 part of flatting agent, 0.1 to 1 part of dispersing agent, 0.1 to 1 part of wetting agent, 0.05 to 0.1 part of mildew preventive and 1 to 10 parts of water. The invention has the following beneficial effects: the mixture of acrylic acid and polyurethane is taken as a main component, the cosolvent and the mildew inhibitor are added, the leveling agent of the curing agent is replaced, and the VOC release amount is greatly reduced in cooperation with the drying process; the paint surface has good hardness, adhesive force and water resistance, and has good mildew resistance.

Description

Technical Field

[0001] The invention relates to the field of wood paint, in particular to low VOC wood paint and a preparation method thereof. Background Art

[0002] In recent years, as wood paint is increasingly used in interior decoration, the pollution and environmental issues of wood paint have attracted more and more attention. According to statistics, the amount of wood paint used in the world each year has reached millions of tons. The harmful substances contained in these wood paints are very volatile, which will cause great harm to human health and irreversible damage to the environment. Therefore, how to reduce the impact of VOC of wood paint on the environment and human health has become an important issue facing today's society.

[0003] At present, the types of wood paint mainly include polyurethane paint, polyester paint, nitro paint, alkyd paint, acrylic paint, water-based wood paint, etc. Among them, water-based wood paint is the mainstream today, and it is divided into the following three categories: acrylic water-based paint, polyurethane water-based paint, and water-based paint with acrylic acid and polyurethane as the main components. The environmental pollution of wood paint mainly comes from two aspects. One is the harmful substances contained in the paint itself, and the other is the volatile organic compounds (VOC) that may be generated during the construction of wood paint. The paint itself is composed of a variety of harmful substances, such as benzene and formaldehyde. These harmful substances can evaporate into the air and cause harm to the human body and the environment. After the construction of wood paint, volatile organic compounds (VOC) will be generated, which will be adsorbed by the indoor environment, resulting in an increase in the concentration of pollutants and forming indoor pollution. Studies have shown that when the indoor content of wood paint exceeds 0.6mg / m3, it will cause irritation to the human eyes and respiratory tract. When the indoor content exceeds 1.2mg / m3, it may even cause symptoms such as headache, drowsiness, rapid heartbeat, and nausea. Summary of the invention

[0004] In order to overcome the disadvantages of existing wood paints that may cause adverse effects on the environment and human health, the present invention provides a low-VOC wood paint and a preparation method thereof.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a low-VOC wood paint, the wood paint comprising a main paint and a curing agent; The weight proportions of various raw materials in the main paint are: acrylic emulsion: 40-60 parts, polyurethane emulsion: 10-20 parts, cosolvent: 2-3 parts, film-forming aid: 2-5 parts, titanium dioxide: 15-25 parts, leveling agent A: 0.5-1 parts, thickener: 0.5-1 parts, defoamer: 0.1-0.5 parts, deaerator: 0.1-0.3 parts, matting agent: 0.1-1 parts, dispersant: 0.1-1 parts, wetting agent: 0.1-1 parts, mildewproof agent: 0.05-0.1 parts, water: 1-10 parts; The weight proportions of various raw materials in the curing agent are as follows: dewatering agent: 0.5-1 part, isocyanate curing agent: 55-75 parts, leveling agent B: 25-45 parts, coupling agent: 0.3-1 part.

[0006] According to another embodiment of the present invention, the acrylic emulsion is an aqueous hydroxy acrylic emulsion, the polyurethane emulsion is an aqueous polyurethane resin emulsion, the cosolvent is propylene glycol butyl ether, the film-forming aid is dipropylene glycol methyl ether or dipropylene glycol butyl ether, the leveling agent A is an isocyanate-modified organic siloxane, the thickener is a polyurethane thickening and leveling agent, the defoaming agent is polydimethylsiloxane and polyether-modified polydimethylsiloxane, the defoaming agent is an organic silicone aqueous emulsion type defoaming agent, the matting agent is an aqueous silica matting powder, the dispersant is a modified styrene maleic acid copolymer solution, the wetting agent is an organic silicone twin structure surfactant, the mildew inhibitor is a SIG composite preservative or MIT+ BIT, the water is deionized water, the water remover is a polyurethane dehydrating agent, the isocyanate curing agent is based on HDI hydrophilic fatty cluster polyisocyanate, the leveling agent B is propylene glycol diacetate or propylene glycol methyl ether acetate, and the coupling agent is a silane coupling agent.

[0007] According to another embodiment of the present invention, the present invention further comprises 50 parts of the acrylic emulsion, 20 parts of the polyurethane emulsion, 1 part of the cosolvent, 2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether, 15 parts of titanium dioxide, 0.8 parts of leveling agent A, 0.5 parts of thickener, 0.3 parts of defoamer, 0.1 parts of degassing agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.2 parts of wetting agent, 0.1 parts of mildewproof agent, 5 parts of water, 0.5 parts of water remover, 65 parts of isocyanate curing agent, 35 parts of leveling agent B and 0.6 parts of coupling agent.

[0008] According to another embodiment of the present invention, the present invention further comprises 50 parts of the acrylic emulsion, 20 parts of the polyurethane emulsion, 2 parts of the cosolvent, 2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether, 15 parts of titanium dioxide, 0.8 parts of leveling agent A, 0.5 parts of thickener, 0.3 parts of defoamer, 0.1 parts of degassing agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.2 parts of wetting agent, 0.1 parts of mildewproof agent, 5 parts of water, 0.5 parts of water remover, 65 parts of isocyanate curing agent, 35 parts of leveling agent and 0.6 parts of coupling agent.

[0009] According to another embodiment of the present invention, the present invention further comprises 50 parts of the acrylic emulsion, 20 parts of the polyurethane emulsion, 1 part of the cosolvent, 3 parts of dipropylene glycol methyl ether or 2 parts of dipropylene glycol butyl ether, 15 parts of titanium dioxide, 0.8 parts of leveling agent A, 0.5 parts of thickener, 0.3 parts of defoamer, 0.1 parts of degassing agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.2 parts of wetting agent, 0.1 parts of mildewproof agent, 5 parts of water, 0.5 parts of water remover, 65 parts of isocyanate curing agent, 35 parts of leveling agent and 0.6 parts of coupling agent.

[0010] According to another embodiment of the present invention, the present invention further comprises 50 parts of the acrylic emulsion, 20 parts of the polyurethane emulsion, 1 part of the cosolvent, 2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether, 15 parts of titanium dioxide, 0.8 parts of leveling agent A, 0.5 parts of thickener, 0.3 parts of defoamer, 0.1 parts of degassing agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.2 parts of wetting agent, 0.2 parts of mildewproof agent, 5 parts of water, 0.5 parts of water remover, 65 parts of isocyanate curing agent, 35 parts of leveling agent and 0.6 parts of coupling agent.

[0011] A method for preparing a low-VOC wood paint comprises the following steps: S1, adding acrylic emulsion and polyurethane emulsion into disperser 1, stirring at 40-50°C to obtain mixed solution A; S2. At room temperature, add titanium dioxide, cosolvent, defoamer, leveling agent A, wetting agent, matting agent, dispersant, defoamer and mildew preventer into disperser 2, mix evenly and homogenize to obtain mixed solution B; S3, slowly add the mixed solution B into the disperser 1, and the disperser 1 is stirred at 40-50°C; after all the mixed solution B is added, continue stirring to obtain the mixed solution C; S4, the disperser 1 where the mixed solution C is located is continuously stirred at 40-50°C and 1000 rpm, while adding a film-forming aid and a thickener to the mixed solution C in sequence; after the film-forming aid and the thickener are all added, stirring is continued for 20 minutes to obtain a mixed solution D; S5. Add water to the mixed solution D at 40-50° C. and stir to obtain the main paint; S6. Add dehydrating agent and leveling agent B to disperser 3 and stir; when the moisture content is detected to be lower than 0.05%, add isocyanate curing agent and coupling agent, and continue stirring for 30 minutes at a speed of 800 rpm to obtain a curing agent; S7. S7. Main paint: curing agent: water are mixed in a mass ratio of 10:1:1 and stirred evenly to obtain wood paint.

[0012] According to another embodiment of the present invention, the method further comprises the step S1, wherein the acrylic emulsion and the polyurethane emulsion are stirred in a disperser 1 at a speed of 500 rpm for 5 minutes; In step S3, the mixed solution B is stirred at 1000 rpm during the process of being added into the disperser 1; after all the mixed solution B is added, stirring is continued for 20 minutes to obtain a mixed solution C; In step S4, the disperser containing the mixed solution C is continuously stirred at 1000 rpm; after the film-forming aid and the thickener are all added, stirring is continued for 20 minutes to obtain a mixed solution D; In step S5, after adding water to the mixed solution D, the mixed solution is stirred at a speed of 500 rpm for 10 minutes to obtain the main paint.

[0013] According to another embodiment of the present invention, the method further comprises step S6, wherein the dehydrating agent and the leveling agent B are stirred in a disperser at a speed of 1000 rpm for 20 minutes; The film-forming aid and thickener were added to the mixed solution D and stirred for 20 minutes.

[0014] A drying process for low-VOC wood paint, wherein the wood paint is dried in a drying room after being applied; the temperature of the drying room is 39-45°C, the humidity is 30%, and the air in the drying room is replaced every 2 hours; after the article is coated with two coats of primer, it is dried in the drying room for 6 hours, then taken out and dried at room temperature for 2 hours; then, a topcoat is applied on the primer, the article is dried in the drying room for 24 hours, and then taken out and dried naturally at room temperature for 24 hours.

[0015] The beneficial effect of the present invention is that the invention uses a mixture of acrylic acid and polyurethane as the main component, and at the same time adds a co-solvent and a mildew preventer, replaces the leveling agent of the commonly used curing agent, and cooperates with the drying process of the invention to greatly reduce the VOC release after 3 days; the paint surface has good hardness, adhesion, water resistance, and good mildew resistance. DETAILED DESCRIPTION

[0016] A low-VOC wood paint, comprising a main paint and a curing agent; The weight proportions of various raw materials in the main paint are: acrylic emulsion: 40-60 parts, polyurethane emulsion: 10-20 parts, cosolvent: 2-3 parts, film-forming aid: 2-5 parts, titanium dioxide: 15-25 parts, leveling agent A: 0.5-1 parts, thickener: 0.5-1 parts, defoamer: 0.1-0.5 parts, deaerator: 0.1-0.3 parts, matting agent: 0.1-1 parts, dispersant: 0.1-1 parts, wetting agent: 0.1-1 parts, mildewproof agent: 0.05-0.1 parts, water: 1-10 parts; The weight proportions of various raw materials in the curing agent are as follows: dewatering agent: 0.5-1 part, isocyanate curing agent: 55-75 parts, leveling agent B: 25-45 parts, coupling agent: 0.3-1 part.

[0017] The acrylic emulsion is a water-based hydroxy acrylic emulsion, the polyurethane emulsion is a water-based polyurethane resin emulsion, the cosolvent is propylene glycol butyl ether, the film-forming aid is dipropylene glycol methyl ether or dipropylene glycol butyl ether, the leveling agent A is an isocyanate-modified organic siloxane, the thickener is a polyurethane thickening and leveling agent, the defoaming agent is polydimethylsiloxane and polyether-modified polydimethylsiloxane, the defoaming agent is a silicone aqueous emulsion type defoaming agent, the matting agent is an aqueous silica matting powder, the dispersant is a modified styrene maleic acid copolymer solution, the wetting agent is a silicone twin structure surfactant, the mildew inhibitor is a SIG composite preservative or MIT+ BIT, the water is deionized water, the water remover is a polyurethane dehydrating agent, the isocyanate curing agent is based on HDI hydrophilic fatty cluster polyisocyanate, the leveling agent B is propylene glycol diacetate or propylene glycol methyl ether acetate, and the coupling agent is a silane coupling agent.

[0018] Acrylic emulsion: 50 parts, polyurethane emulsion: 20 parts, cosolvent: 1 part, dipropylene glycol methyl ether 2 parts or dipropylene glycol butyl ether 1 part, titanium dioxide: 15 parts, leveling agent A: 0.8 parts, thickener: 0.5 parts, defoamer: 0.3 parts, deaerator: 0.1 parts, matting agent: 0.5 parts, dispersant: 0.3 parts, wetting agent: 0.2 parts, mildewproofing agent: 0.1 parts, water: 5 parts, dewatering agent: 0.5 parts, isocyanate curing agent: 65 parts, leveling agent B: 35 parts, coupling agent: 0.6 parts.

[0019] Acrylic emulsion: 50 parts, polyurethane emulsion: 20 parts, cosolvent: 2 parts, dipropylene glycol methyl ether 2 parts or dipropylene glycol butyl ether 1 part, titanium dioxide: 15 parts, leveling agent A: 0.8 parts, thickener: 0.5 parts, defoamer: 0.3 parts, deaerator: 0.1 parts, matting agent: 0.5 parts, dispersant: 0.3 parts, wetting agent: 0.2 parts, mildewproofing agent: 0.1 parts, water: 5 parts, dewatering agent: 0.5 parts, isocyanate curing agent: 65 parts, leveling agent: 35 parts, coupling agent: 0.6 parts.

[0020] Acrylic emulsion: 50 parts, polyurethane emulsion: 20 parts, cosolvent: 1 part, dipropylene glycol methyl ether 3 parts or dipropylene glycol butyl ether 2 parts, titanium dioxide: 15 parts, leveling agent A: 0.8 parts, thickener: 0.5 parts, defoamer: 0.3 parts, deaerator: 0.1 parts, matting agent: 0.5 parts, dispersant: 0.3 parts, wetting agent: 0.2 parts, mildewproofing agent: 0.1 parts, water: 5 parts, dewatering agent: 0.5 parts, isocyanate curing agent: 65 parts, leveling agent: 35 parts, coupling agent: 0.6 parts.

[0021] Acrylic emulsion: 50 parts, polyurethane emulsion: 20 parts, cosolvent: 1 part, dipropylene glycol methyl ether 2 parts or dipropylene glycol butyl ether 1 part, titanium dioxide: 15 parts, leveling agent A: 0.8 parts, thickener: 0.5 parts, defoamer: 0.3 parts, deaerator: 0.1 parts, matting agent: 0.5 parts, dispersant: 0.3 parts, wetting agent: 0.2 parts, mildewproofing agent: 0.2 parts, water: 5 parts, dewatering agent: 0.5 parts, isocyanate curing agent: 65 parts, leveling agent: 35 parts, coupling agent: 0.6 parts.

[0022] A method for preparing a low-VOC wood paint comprises the following steps: S1. Add acrylic emulsion and polyurethane emulsion into a disperser 1, and stir at 40-50° C. to obtain a mixed solution A; stir the acrylic emulsion and polyurethane emulsion in the disperser 1 at a speed of 500 rpm for 5 minutes.

[0023] S2. At room temperature, add titanium dioxide, cosolvent, defoamer, leveling agent A, wetting agent, matting agent, dispersant, defoamer and mildew preventer into disperser 2, mix evenly and homogenize to obtain mixed solution B; S3. Slowly add the mixed solution B into the disperser 1, and the disperser 1 is stirred at 40-50°C; after all the mixed solution B is added, continue stirring to obtain a mixed solution C; while adding the mixed solution B into the disperser 1, stir at 1000 rpm; after all the mixed solution B is added, continue stirring for 20 minutes to obtain a mixed solution C.

[0024] S4. The disperser 1 where the mixed liquid C is located is continuously stirred at 40-50°C and 1000 rpm, and a film-forming aid and a thickener are added to the mixed liquid C in sequence; after the film-forming aid and the thickener are completely added, stirring is continued for 20 minutes to obtain a mixed liquid D; the disperser where the mixed liquid C is located is continuously stirred at 1000 rpm; after the film-forming aid and the thickener are completely added, stirring is continued for 20 minutes to obtain a mixed liquid D.

[0025] S5. Add water to the mixed solution D at 40-50° C. and stir to obtain a main paint; after adding water to the mixed solution D, stir at a speed of 500 rpm for 10 minutes to obtain a main paint.

[0026] S6. Add dewatering agent and leveling agent B into disperser 3 and stir; when the moisture content is detected to be lower than 0.05%, add isocyanate curing agent and coupling agent, and continue stirring for 30 minutes at a speed of 800 rpm to obtain curing agent; stir dewatering agent and leveling agent B in disperser 3 at a speed of 1000 rpm for 20 minutes; add film-forming aid and thickener into mixed solution D and stir for 20 minutes.

[0027] S7. Main paint: curing agent: water are mixed in a mass ratio of 10:1:1 and stirred evenly to obtain wood paint.

[0028] A low-VOC wood paint drying process, the wood paint is dried in a drying room after being applied; the temperature of the drying room is 39-45°C, the humidity is 30%, and the air in the drying room is replaced every 2 hours; after the object is coated with two coats of primer, it is dried in the drying room for 6 hours, then taken out and dried at room temperature for 2 hours; then the object is coated with a topcoat on the primer and dried in the drying room for 24 hours, and then taken out and dried naturally at room temperature for 24 hours. Example

[0029] Configure the main paint: 1. Add 50 parts of aqueous hydroxy acrylic emulsion and 20 parts of aqueous polyurethane resin emulsion into a disperser 1, stir at 40-50° C. and 500 rpm for 5 minutes to obtain a mixed solution A.

[0030] 2. At room temperature, add 15 parts of titanium dioxide, 1 part of cosolvent, 0.3 parts of defoaming agent, 0.8 parts of leveling agent, 0.2 parts of wetting agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.1 parts of defoaming agent and 0.1 parts of mildewproof agent into disperser 2, mix well and homogenize to obtain mixed solution B.

[0031] 3. Slowly add mixed solution B into disperser 1. The temperature in disperser 1 is 40-50°C. Stir at a speed of 1000 rpm. After all the mixture is added, continue stirring for 20 minutes to obtain mixed solution C.

[0032] 4. The temperature in disperser 1 is 40-50°C, and the mixture is stirred at a speed of 1000 rpm. Film-forming aid (2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether) and 0.5 parts of thickener are added to mixed solution C in sequence. After all the addition is completed, stirring is continued for 20 minutes to obtain mixed solution D.

[0033] Finally, 5 parts of water were added to the mixed solution D at 40-50° C., and the mixture was stirred at 500 rpm for 10 minutes to obtain the main paint.

[0034] Preparation of curing agent: 1. First, add 0.5 parts of dehydrating agent and 35 parts of propylene glycol diacetate into disperser 3. The speed of disperser 3 is 1000r / min, and stir for 20 minutes.

[0035] 2. When the moisture content is detected to be lower than 0.05%, 65 parts of HDI hydrophilic fatty cluster polyisocyanate and 0.6 parts of silane coupling agent are added, and stirring is continued for 30 minutes at a speed of 800 r / min to obtain a curing agent.

[0036] Prepare two-component water-based wood paint: mix main paint: curing agent: water in a ratio of 10:1:1 (mass ratio), and stir evenly to obtain the two-component water-based wood paint.

[0037] Drying process: The mixed oil adopts the spraying process of two primers and one side, and is dried in a self-built constant temperature and humidity / air circulation drying room. The temperature of the drying room is controlled at 42±3℃, the humidity is controlled at 30%, and the air in the drying room is replaced every 2 hours. The two primer processes are taken out after drying in the drying room for 6 hours and dried at room temperature for 2 hours. The topcoat is taken out after drying in the drying room for 24 hours, and packaged after drying naturally at room temperature for 24 hours. Example

[0038] Configure the main paint: 1. Add 50 parts of aqueous hydroxy acrylic emulsion and 20 parts of aqueous polyurethane resin emulsion into a disperser 1, stir at 40-50° C. and 500 rpm for 5 minutes to obtain a mixed solution A.

[0039] 2. At room temperature, add 15 parts of titanium dioxide, 2 parts of cosolvent, 0.3 parts of defoamer, 0.8 parts of leveling agent, 0.2 parts of wetting agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.1 parts of defoamer and 0.1 parts of mildewproof agent into disperser 2, mix well and homogenize to obtain mixed solution B.

[0040] 3. Slowly add mixed solution B into disperser 1. The temperature in disperser 1 is 40-50°C. Stir at a speed of 1000 rpm. After all the mixture is added, continue stirring for 20 minutes to obtain mixed solution C.

[0041] 4. The temperature in disperser 1 is 40-50°C, and the mixture is stirred at a speed of 1000 rpm. Film-forming aid (2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether) and 0.5 parts of thickener are added to mixed solution C in sequence. After all the addition is completed, stirring is continued for 20 minutes to obtain mixed solution D.

[0042] Finally, 5 parts of water were added to the mixed solution D at 40-50° C., and the mixture was stirred at 500 rpm for 10 minutes to obtain the main paint.

[0043] Preparation of curing agent: 1. First, add 0.5 parts of dehydrating agent and 35 parts of propylene glycol diacetate into disperser 3. The speed of disperser 3 is 1000r / min, and stir for 20 minutes.

[0044] 2. When the moisture content is detected to be lower than 0.05%, 65 parts of HDI hydrophilic fatty cluster polyisocyanate and 0.6 parts of silane coupling agent are added, and stirring is continued for 30 minutes at a speed of 800 r / min to obtain a curing agent.

[0045] Prepare two-component water-based wood paint: mix main paint: curing agent: water in a ratio of 10:1:1 (mass ratio), and stir evenly to obtain the two-component water-based wood paint.

[0046] Drying process: The mixed oil adopts the spraying process of two primers and one side, and is dried in a self-built constant temperature and humidity / air circulation drying room. The temperature of the drying room is controlled at 42±3℃, the humidity is controlled at 30%, and the air in the drying room is replaced every 2 hours. The two primer processes are taken out after drying in the drying room for 6 hours and dried at room temperature for 2 hours. The topcoat is taken out after drying in the drying room for 24 hours, and packaged after drying naturally at room temperature for 24 hours. Example

[0047] Configure the main paint: 1. Add 50 parts of aqueous hydroxy acrylic emulsion and 20 parts of aqueous polyurethane resin emulsion into a disperser 1, stir at 40-50° C. and 500 rpm for 5 minutes to obtain a mixed solution A.

[0048] 2. At room temperature, add 15 parts of titanium dioxide, 1 part of cosolvent, 0.3 parts of defoaming agent, 0.8 parts of leveling agent, 0.2 parts of wetting agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.1 parts of defoaming agent and 0.1 parts of mildewproof agent into disperser 2, mix well and homogenize to obtain mixed solution B.

[0049] 3. Slowly add mixed solution B into disperser 1. The temperature in disperser 1 is 40-50°C. Stir at a speed of 1000 rpm. After all the mixture is added, continue stirring for 20 minutes to obtain mixed solution C.

[0050] 4. The temperature in disperser 1 is 40-50°C, and the mixture is stirred at a speed of 1000 rpm. Film-forming aid (3 parts of dipropylene glycol methyl ether or 2 parts of dipropylene glycol butyl ether) and 0.5 parts of thickener are added to mixed solution C in sequence. After all the addition is completed, stirring is continued for 20 minutes to obtain mixed solution D.

[0051] Finally, 5 parts of water were added to the mixed solution D at 40-50° C., and the mixture was stirred at 500 rpm for 10 minutes to obtain the main paint.

[0052] Preparation of curing agent: 1. First, add 0.5 parts of dehydrating agent and 35 parts of propylene glycol diacetate into disperser 3. The speed of disperser 3 is 1000r / min, and stir for 20 minutes.

[0053] 2. When the moisture content is detected to be lower than 0.05%, 65 parts of HDI hydrophilic fatty cluster polyisocyanate and 0.6 parts of silane coupling agent are added, and stirring is continued for 30 minutes at a speed of 800 r / min to obtain a curing agent.

[0054] Prepare two-component water-based wood paint: mix main paint: curing agent: water in a ratio of 10:1:1 (mass ratio), and stir evenly to obtain the two-component water-based wood paint.

[0055] Drying process: The mixed oil adopts the spraying process of two primers and one side, and is dried in a self-built constant temperature and humidity / air circulation drying room. The temperature of the drying room is controlled at 42±3℃, the humidity is controlled at 30%, and the air in the drying room is replaced every 2 hours. The two primer processes are taken out after drying in the drying room for 6 hours and dried at room temperature for 2 hours. The topcoat is taken out after drying in the drying room for 24 hours, and packaged after drying naturally at room temperature for 24 hours. Example

[0056] Configure the main paint: 1. Add 50 parts of aqueous hydroxy acrylic emulsion and 20 parts of aqueous polyurethane resin emulsion into a disperser 1, stir at 40-50° C. and 500 rpm for 5 minutes to obtain a mixed solution A.

[0057] 2. At room temperature, add 15 parts of titanium dioxide, 1 part of cosolvent, 0.3 parts of defoamer, 0.8 parts of leveling agent, 0.2 parts of wetting agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.1 parts of defoamer and 0.2 parts of mildewproof agent into disperser 2, mix well and homogenize to obtain mixed solution B.

[0058] 3. Slowly add mixed solution B into disperser 1. The temperature in disperser 1 is 40-50°C. Stir at a speed of 1000 rpm. After all the mixture is added, continue stirring for 20 minutes to obtain mixed solution C.

[0059] 4. The temperature in disperser 1 is 40-50°C, and the mixture is stirred at a speed of 1000 rpm. Film-forming aid (2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether) and 0.5 parts of thickener are added to mixed solution C in sequence. After all the addition is completed, stirring is continued for 20 minutes to obtain mixed solution D.

[0060] Finally, 5 parts of water were added to the mixed solution D at 40-50° C., and the mixture was stirred at 500 rpm for 10 minutes to obtain the main paint.

[0061] Preparation of curing agent: 1. First, add 0.5 parts of dehydrating agent and 35 parts of propylene glycol diacetate into disperser 3. The speed of disperser 3 is 1000r / min, and stir for 20 minutes.

[0062] 2. When the moisture content is detected to be lower than 0.05%, 65 parts of HDI hydrophilic fatty cluster polyisocyanate and 0.6 parts of silane coupling agent are added, and stirring is continued for 30 minutes at a speed of 800 r / min to obtain a curing agent.

[0063] Prepare two-component water-based wood paint: mix main paint: curing agent: water in a ratio of 10:1:1 (mass ratio), and stir evenly to obtain the two-component water-based wood paint.

[0064] Drying process: The mixed oil adopts the spraying process of two primers and one side, and is dried in a self-built constant temperature and humidity / air circulation drying room. The temperature of the drying room is controlled at 42±3℃, the humidity is controlled at 30%, and the air in the drying room is replaced every 2 hours. The two primer processes are taken out after drying in the drying room for 6 hours and dried at room temperature for 2 hours. The topcoat is taken out after drying in the drying room for 24 hours, and packaged after drying naturally at room temperature for 24 hours.

[0065] Comparative Example 1: Configure the main paint: 1. Add 50 parts of aqueous hydroxy acrylic emulsion and 20 parts of aqueous polyurethane resin emulsion into a disperser 1, stir at 40-50° C. and 500 rpm for 5 minutes to obtain a mixed solution A.

[0066] 2. At room temperature, add 15 parts of titanium dioxide, 0 parts of cosolvent, 0.3 parts of defoamer, 0.8 parts of leveling agent, 0.2 parts of wetting agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.1 parts of defoamer and 0 parts of mildewproofing agent into disperser 2, mix well and homogenize to obtain mixed solution B.

[0067] 3. Slowly add mixed solution B into disperser 1. The temperature in disperser 1 is 40-50°C. Stir at a speed of 1000 rpm. After all the mixture is added, continue stirring for 20 minutes to obtain mixed solution C.

[0068] 4. The temperature in disperser 1 is 40-50°C, and the mixture is stirred at a speed of 1000 rpm. Film-forming aid (2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether) and 0.5 parts of thickener are added to mixed solution C in sequence. After all the addition is completed, stirring is continued for 20 minutes to obtain mixed solution D.

[0069] Finally, 5 parts of water were added to the mixed solution D at 40-50° C., and the mixture was stirred at 500 rpm for 10 minutes to obtain the main paint.

[0070] Preparation of curing agent: 1. First, add 0.5 parts of dehydrating agent and 35 parts of propylene glycol methyl ether acetate into disperser 3. The speed of disperser 3 is 1000r / min, and stir for 20 minutes.

[0071] 2. When the moisture content is detected to be lower than 0.05%, 65 parts of HDI hydrophilic fatty cluster polyisocyanate and 0.6 parts of silane coupling agent are added, and stirring is continued for 30 minutes at a speed of 800 r / min to obtain a curing agent.

[0072] Prepare two-component water-based wood paint: mix main paint: curing agent: water in a ratio of 10:1:1 (mass ratio), and stir evenly to obtain the two-component water-based wood paint.

[0073] Drying process: The mixed oil adopts the spraying process of two primers and one side, and is dried in a self-built constant temperature and humidity / air circulation drying room. The temperature of the drying room is controlled at 42±3℃, the humidity is controlled at 30%, and the air in the drying room is replaced every 2 hours. The two primer processes are taken out of the drying room after drying for 6 hours and dried at room temperature for 2 hours. The topcoat is taken out after drying in the drying room for 24 hours, and packaged after drying naturally at room temperature for 24 hours. Comparative Example 2 Configure the main paint: 1. Add 50 parts of aqueous hydroxy acrylic emulsion and 20 parts of aqueous polyurethane resin emulsion into a disperser 1, stir at 40-50° C. and 500 rpm for 5 minutes to obtain a mixed solution A.

[0074] 2. At room temperature, add 15 parts of titanium dioxide, 1 part of cosolvent, 0.3 parts of defoaming agent, 0.8 parts of leveling agent, 0.2 parts of wetting agent, 0.5 parts of matting agent, 0.3 parts of dispersant, 0.1 parts of defoaming agent and 0.1 parts of mildewproof agent into disperser 2, mix well and homogenize to obtain mixed solution B.

[0075] 3. Slowly add mixed solution B into disperser 1. The temperature in disperser 1 is 40-50°C. Stir at a speed of 1000 rpm. After all the mixture is added, continue stirring for 20 minutes to obtain mixed solution C.

[0076] 4. The temperature in disperser 1 is 40-50°C, and the mixture is stirred at a speed of 1000 rpm. Film-forming aid (2 parts of dipropylene glycol methyl ether or 1 part of dipropylene glycol butyl ether) and 0.5 parts of thickener are added to mixed solution C in sequence. After all the addition is completed, stirring is continued for 20 minutes to obtain mixed solution D.

[0077] Finally, 5 parts of water were added to the mixed solution D at 40-50° C., and the mixture was stirred at 500 rpm for 10 minutes to obtain the main paint.

[0078] Preparation of curing agent: 1. First, add 0.5 parts of dehydrating agent and 35 parts of propylene glycol diacetate into disperser 3. The speed of disperser 3 is 1000r / min, and stir for 20 minutes.

[0079] 2. When the moisture content is detected to be lower than 0.05%, 65 parts of HDI hydrophilic fatty cluster polyisocyanate and 0.6 parts of silane coupling agent are added, and stirring is continued for 30 minutes at a speed of 800 r / min to obtain a curing agent.

[0080] Prepare two-component water-based wood paint: mix main paint: curing agent: water in a ratio of 10:1:1 (mass ratio), and stir evenly to obtain the two-component water-based wood paint.

[0081] Drying process: The mixed oil adopts the spraying process of two primers and one side, and is dried in a self-built constant temperature and humidity / air circulation drying room. The temperature of the drying room is controlled at 42±3℃, the humidity is controlled at 40%, and the air in the drying room is replaced every 5 hours. The two primer processes are dried in the drying room for 4 hours without drying. The topcoat is dried in the drying room for 12 hours, then taken out and packaged after being naturally dried at room temperature for 2 hours.

[0082] Performance test and result description table of this application:

[0083] (1) It can be seen from Example 1, Example 2 and Comparative Example 1 that the addition of a cosolvent can improve the hardness of the paint film of the system, but excessive addition will lead to an increase in the amount of VOC volatilization; the VOC volatilization amount of propylene glycol diacetate, a leveling agent in the curing agent, is much smaller than that of propylene glycol methyl ether acetate; the addition of a mildew inhibitor is beneficial to the mildew-proof effect; (2) It can be seen from Examples 1 and 3 that the addition of too much film-forming agent is not conducive to the hardness of the paint film and the amount of VOC volatilization, and also prolongs the drying time; (3) It can be seen from Examples 1 and 4 that the addition of too much mildew inhibitor has little effect on the mildew-proof effect, but will reduce the adhesion of the paint film; It can be seen from Example 1 and Comparative Example 2 that the increase of the humidity in the drying room is not conducive to the drying time; the increase of the ventilation frequency in the drying room and the extension of the drying time are very beneficial to the reduction of the VOC volatilization amount.

Claims

1. A low VOC wood paint, characterized in that: The wood paint comprises a main paint and a curing agent; The weight proportions of various raw materials in the main paint are: acrylic emulsion: 40-60 parts, polyurethane emulsion: 10-20 parts, cosolvent: 2-3 parts, film-forming aid: 2-5 parts, titanium dioxide: 15-25 parts, leveling agent A: 0.5-1 parts, thickener: 0.5-1 parts, defoamer: 0.1-0.5 parts, deaerator: 0.1-0.3 parts, matting agent: 0.1-1 parts, dispersant: 0.1-1 parts, wetting agent: 0.1-1 parts, mildewproof agent: 0.05-0.1 parts, water: 1-10 parts; The weight proportions of various raw materials in the curing agent are as follows: dewatering agent: 0.5-1 part, isocyanate curing agent: 55-75 parts, leveling agent B: 25-45 parts, coupling agent: 0.3-1 part.

2. The low VOC wood paint according to claim 1, characterized in that: The acrylic emulsion is an aqueous hydroxy acrylic emulsion, the polyurethane emulsion is an aqueous polyurethane resin emulsion, the cosolvent is propylene glycol butyl ether, the film-forming aid is dipropylene glycol methyl ether or dipropylene glycol butyl ether, the leveling agent A is an isocyanate-modified organic siloxane, the thickener is a polyurethane thickening and leveling agent, the defoaming agent is polydimethylsiloxane and polyether-modified polydimethylsiloxane, the defoaming agent is an organic silicone aqueous emulsion type defoaming agent, the matting agent is an aqueous silica matting powder, the dispersant is a modified styrene maleic acid copolymer solution, the wetting agent is an organic silicone twin structure surfactant, the mildewproof agent is a SIG composite preservative or MIT+BIT, the water is deionized water, the water remover is a polyurethane dehydrating agent, the isocyanate curing agent is based on HDI hydrophilic fatty cluster polyisocyanate, the leveling agent B is propylene glycol diacetate or propylene glycol methyl ether acetate, and the coupling agent is a silane coupling agent.

3. The low VOC wood paint according to claim 2, characterized in that: The acrylic emulsion: 50 parts, the polyurethane emulsion: 20 parts, the cosolvent: 1 part, the dipropylene glycol methyl ether: 2 parts or the dipropylene glycol butyl ether: 1 part, the titanium dioxide: 15 parts, the leveling agent A: 0.8 parts, the thickener: 0.5 parts, the defoamer: 0.3 parts, the deaerator: 0.1 parts, the matting agent: 0.5 parts, the dispersant: 0.3 parts, the wetting agent: 0.2 parts, the mildewproof agent: 0.1 parts, the water: 5 parts, the water removing agent: 0.5 parts, the isocyanate curing agent: 65 parts, the leveling agent B: 35 parts, and the coupling agent: 0.6 parts.

4. The low VOC wood paint according to claim 1, characterized in that: The acrylic emulsion: 50 parts, the polyurethane emulsion: 20 parts, the cosolvent: 2 parts, the dipropylene glycol methyl ether 2 parts or the dipropylene glycol butyl ether 1 part, the titanium dioxide: 15 parts, the leveling agent A: 0.8 parts, the thickener: 0.5 parts, the defoamer: 0.3 parts, the deaerator: 0.1 parts, the matting agent: 0.5 parts, the dispersant: 0.3 parts, the wetting agent: 0.2 parts, the mildewproof agent: 0.1 parts, the water: 5 parts, the water removing agent: 0.5 parts, the isocyanate curing agent: 65 parts, the leveling agent: 35 parts, and the coupling agent: 0.6 parts.

5. The low VOC wood paint according to claim 1, characterized in that: The acrylic emulsion: 50 parts, the polyurethane emulsion: 20 parts, the cosolvent: 1 part, the dipropylene glycol methyl ether: 3 parts or the dipropylene glycol butyl ether: 2 parts, the titanium dioxide: 15 parts, the leveling agent A: 0.8 parts, the thickener: 0.5 parts, the defoamer: 0.3 parts, the deaerator: 0.1 parts, the matting agent: 0.5 parts, the dispersant: 0.3 parts, the wetting agent: 0.2 parts, the mildewproof agent: 0.1 parts, the water: 5 parts, the water removing agent: 0.5 parts, the isocyanate curing agent: 65 parts, the leveling agent: 35 parts, and the coupling agent: 0.6 parts.

6. The low VOC wood paint according to claim 1, characterized in that: The acrylic emulsion: 50 parts, the polyurethane emulsion: 20 parts, the cosolvent: 1 part, the dipropylene glycol methyl ether: 2 parts or the dipropylene glycol butyl ether: 1 part, the titanium dioxide: 15 parts, the leveling agent A: 0.8 parts, the thickener: 0.5 parts, the defoamer: 0.3 parts, the deaerator: 0.1 parts, the matting agent: 0.5 parts, the dispersant: 0.3 parts, the wetting agent: 0.2 parts, the mildewproof agent: 0.2 parts, the water: 5 parts, the water removing agent: 0.5 parts, the isocyanate curing agent: 65 parts, the leveling agent: 35 parts, and the coupling agent: 0.6 parts.

7. A method for preparing a low VOC wood paint according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, adding acrylic emulsion and polyurethane emulsion into disperser 1, stirring at 40-50°C to obtain mixed solution A; S2. At room temperature, add titanium dioxide, cosolvent, defoamer, leveling agent A, wetting agent, matting agent, dispersant, defoamer and mildew preventer into disperser 2, mix evenly and homogenize to obtain mixed solution B; S3, slowly add the mixed solution B into the disperser 1, and stir the disperser 1 at 40-50°C; after all the mixed solution B is added, continue stirring to obtain a mixed solution C; S4, the disperser 1 where the mixed solution C is located is continuously stirred at 40-50°C and 1000 rpm, while adding a film-forming aid and a thickener to the mixed solution C in sequence; after the film-forming aid and the thickener are all added, stirring is continued for 20 minutes to obtain a mixed solution D; S5. Add water to the mixed solution D at 40-50° C. and stir to obtain the main paint; S6. Add dehydrating agent and leveling agent B to disperser 3 and stir; when the moisture content is detected to be lower than 0.05%, add isocyanate curing agent and coupling agent, and continue stirring for 30 minutes at a speed of 800 rpm to obtain a curing agent; S7. Main paint: curing agent: water are mixed in a mass ratio of 10:1:1 and stirred evenly to obtain wood paint.

8. The method for preparing a low VOC wood paint according to claim 7, characterized in that the steps In S1, the acrylic emulsion and the polyurethane emulsion are stirred in a disperser 1 at a speed of 500 rpm for 5 minutes; In step S3, the mixed solution B is stirred at 1000 rpm during the process of being added into the disperser 1; After all the mixture B is added, continue stirring for 20 minutes to obtain a mixture C; In step S4, the disperser containing the mixed solution C is continuously stirred at 1000 rpm; after the film-forming aid and the thickener are all added, stirring is continued for 20 minutes to obtain a mixed solution D; In step S5, after adding water to the mixed solution D, the mixture is stirred at a speed of 500 rpm for 10 minutes to obtain the main paint.

9. The method for preparing a low VOC wood paint according to claim 7, characterized in that: In step S6, the dewatering agent and leveling agent B are stirred in a disperser at a speed of 1000 rpm for 20 minutes; The film-forming aid and thickener were added to the mixed solution D and stirred for 20 minutes.

10. The drying process of a low VOC wood paint according to claim 7, characterized in that: After the wood paint is applied, it is dried in a drying room; the temperature in the drying room is 39-45°C, the humidity is 30%, and the air in the drying room is replaced every 2 hours; after the article is coated with two coats of primer, it is dried in the drying room for 6 hours, then taken out and dried at room temperature for 2 hours; then the article is coated with a topcoat on the primer and dried in the drying room for 24 hours, and then taken out and dried naturally at room temperature for 24 hours.

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