CN101067056A - A kind of nano ecological coating - Google Patents

Abstract

The present invention relates to nanometer paint, and is especially one kind of nanometer ecological paint. The nanometer ecological paint is prepared through the following three steps: 1. preparing coating liquid through dissolving NaCl, NaHCO3, KCl, K2HPO4.3H2O, MgCl.6H2O, CaCl2 and Na2SO4 in water; 2. compounding nanometer titania dispersing liquid; and 3. compounding the paint. The present invention features that nanometer titania is dispersed in the special coating liquid under certain reaction condition so that porous hydroxyapatite film is formed on the surface of nanometer titania particle to raise the dispersivity and weather resistance of nanometer titania particle while maintaining high self-cleaning, sterilizing and air-purifying functions.

Description

A kind of nano ecological coating

(1) Technical field

The invention relates to a nano coating, in particular to a nano ecological coating.

(2) Background technology

At present, the problem of environmental pollution in our country is very prominent, especially the urban air pollution is very serious. Industrial coal burning releases a large amount of harmful gases such as sulfur dioxide and carbon monoxide; with the rapid development of the automobile industry, a large amount of nitrogen compounds and carbon monoxide are emitted from automobile exhaust, causing serious air pollution in large and medium-sized cities; many interior decoration materials and furniture will slowly release such as aldehyde Central air conditioners also produce unpleasant odors and spread pathogenic microorganisms.

Reducing pollution and protecting the environment are issues of increasing concern to the general public. Photocatalytic ecological building materials with the function of degrading pollutants will surely become mainstream products in the building materials industry in this century. In recent years, there have been more and more reports on photocatalytic coatings. Adding nano-TiO ₂ , ZnO and other nano-materials to the coating not only significantly enhances the scrub resistance, aging resistance and stain resistance of the coating; it can also purify harmful gases in the air and sterilize.

Nano-titanium dioxide photocatalyst has the advantages of stable chemical properties, oxidation resistance, safety and non-toxicity. Under the irradiation of ultraviolet light, free electron-hole pairs can be generated, which react with oxygen and water adsorbed on the surface of titanium dioxide to generate active oxygen and free radicals. These active oxygen and free radicals have a strong ability to oxidize and decompose, and can oxidize and decompose organic matter into CO ₂ and H ₂ O, and oxidize air pollutants such as NO _x , SO _x , NH ₃ and H ₂ S into harmless substances. It can also penetrate the cell walls of bacteria, molds and other microorganisms adsorbed on the surface of _TiO2 , thereby effectively killing bacteria, and then decontaminating and disinfecting the air to achieve the effect of purifying the air.

But existing nano-titanium dioxide coating also has the following deficiencies:

Adding nano-titanium dioxide to the paint can endow the paint with new functions such as self-cleaning, sterilization, and air purification. At the same time, titanium dioxide will also decompose the organic components in the paint, thereby reducing the weather resistance of the paint.

Due to the small particle size of nano-titanium dioxide, its dispersion in the coating is not good, and it is easy to agglomerate, and its cleaning and bactericidal performance cannot reach the ideal effect.

(3) Contents of the invention

In order to overcome the deficiencies of the above technologies, the present invention provides a nano-ecological coating with excellent dispersibility, stability and weather resistance, so as to improve the self-cleaning, sterilizing and air-purifying functions of the coating.

The present invention is achieved through the following measures:

Nano ecological coating of the present invention is characterized in that adopts following steps to make:

(1) Preparation of coating solution: dissolve NaCl, NaHCO ₃ , KCl, K ₂ HPO ₄ 3H ₂ O, MgCl 6H ₂ O, CaCl ₂ , Na ₂ SO ₄ in water to prepare coating solution;

The concentration of each ion in the coating solution is: Element Na ⁺ K ⁺ Ca ²⁺ Mg ^{2 Cl-} HPO ₄ ^2- HCO ₄ ^- SO ₄ ^2- concentrationmmol/l 142 5.0 2.5 1.5 147.8 1.0 4.2 0.5

(2) Preparation of nano-titanium dioxide dispersion: add nano-titanium dioxide and dispersant to the coating solution, use trishydroxyaminomethane and hydrochloric acid as buffers to adjust the pH value to about 7.3, stir, heat, and react at a constant temperature of 40°C for 2 hours. Filtrate, wash, and finally redisperse the filter cake into water to obtain a nano-titanium dioxide dispersion. The addition amount of nano-titanium dioxide and dispersant are respectively 5-20wt% and 0.1-2wt% of the dispersion liquid;

(3) Coating preparation: mix water, pigment/filler, dispersant, defoamer, film-forming aid, leveling agent, neutralizer and nano-titanium dioxide dispersion, adjust the pH value to 8-10, stir at high speed for 10 -50min, then grind for 30-60min with a sand mill or a three-roller machine to obtain a slurry; add water, emulsion, defoamer, etc. to the slurry for stirring, then add a thickener to adjust the pH value to 9-10, Adjust the coating to a suitable viscosity, stir at a low speed for 30 minutes, and finally obtain a nano-ecological coating; in the prepared coating, water, dispersant, pigment/filler, defoamer, film-forming aid, leveling agent, nano-titanium dioxide, emulsion, thickener The mass percentage of the agent and neutralizer in the coating is 20-45, 0.1-2, 20-45, 0.1-2, 1-5, 0.1-2, 0.5-5, 10-30, 0.2-4, 0.1- 2wt%.

In order to improve the dispersibility of nano-titanium dioxide particles, in step (2), mechanical dispersion, ultrasonic dispersion or chemical dispersion are used to disperse, and the dispersants used are polyacrylic acid salts, polyphosphates, polyethylene glycol One or more diols.

In the above-mentioned nano-ecological coating of the present invention, the surface of the nano-titanium dioxide particles forms a porous hydroxyapatite film in the coating solution.

In the above-mentioned nano-ecological coating of the present invention, the coating rate of the nano-titanium dioxide particle surface is 0.1-99%.

Titanium dioxide can decompose the adsorbed organic pollutants, and also decompose the organic components in the paint, so the rutile titanium dioxide with poor photocatalytic ability is used in the paint (especially the exterior wall paint), and its surface is covered. Override processing. Therefore, necessary surface treatment should be carried out on the nano-titanium dioxide in the nano-coating to improve the weather resistance of the nano-coating.

Hydroxyapatite is a traditional bioceramic material that has a high affinity for proteins and organic pollutants. If the hydroxyapatite coating layer of porous structure is loaded on the surface of nano-titanium dioxide particles, the dispersion and weather resistance of nano-titanium dioxide in the coating can be improved well, and at the same time because the coating layer is porous Organic molecules have a strong adsorption capacity, so the photocatalytic ability of titanium dioxide is still very strong.

The main innovation of the present invention is that nano-titanium dioxide is dispersed in a specially prepared coating solution, and certain reaction conditions are controlled to form a porous hydroxyapatite film on the surface of titanium dioxide nanoparticles, which not only improves the coating of nano-titanium dioxide particles. Dispersion and weather resistance; at the same time, a porous structure film is formed on the surface of nano-titanium dioxide particles, so that it still has high self-cleaning, sterilizing, and air-purifying functions.

(4) Specific implementation methods

Example 1:

Preparation of coating solution: Dissolve NaCl, NaHCO ₃ , KCl, K ₂ HPO ₄ ·3H ₂ O, MgCl·6H ₂ O, CaCl ₂ , Na ₂ SO ₄ in water to prepare coating solution.

The concentration of each ion in the coating solution is: Element Na ⁺ K ⁺ Ca ²⁺ Mg ^{2+ Cl-} HPO ₄ ^2- HCO ₄ ^- SO ₄ ^2- concentrationmmol/l 142 5.0 2.5 1.5 147.8 1.0 4.2 0.5

Preparation of nano-titanium dioxide dispersion liquid: recipe: 5 g of nano-titanium dioxide (anatase type), 0.10 g of potassium polyacrylate, and 50 ml of coating solution.

Add nano-titanium dioxide and dispersant to the coating solution, use trishydroxyaminomethane and hydrochloric acid as buffers to adjust the pH value to about 7.3, stir, heat, react at a constant temperature of 40°C for 2 hours, filter, wash, and finally redisperse the filter cake into 50ml of water to obtain a nano-titanium dioxide dispersion.

Coating preparation: mix water, pigment/filler, dispersant, defoamer, film-forming aid, leveling agent, neutralizer and nano-titanium dioxide dispersion, adjust the pH value to 8-10, stir at high speed for 10-50min, Then grind for 30-60 minutes with a sand mill or a three-roller machine to obtain a slurry.

Add water, emulsion, defoamer, etc. to the slurry for stirring, then add a thickener, adjust the pH value to 9-10, adjust the paint to a suitable viscosity, and stir at a low speed for 30 minutes to obtain a nano-ecological paint.

Water, dispersants, pigments/fillers, defoamers, film-forming aids, leveling agents, nano-titanium dioxide, emulsions, thickeners, and neutralizers account for 35, 0.5, 39, and 0.5 mass percentages of the paint, respectively. , 2, 0.5, 1, 20, 1, 0.5 wt%.

Example 2:

Preparation of coating solution: Dissolve NaCl, NaHCO ₃ , KCl, K ₂ HPO ₄ ·3H ₂ O, MgCl·6H ₂ O, CaCl ₂ , Na ₂ SO ₄ in water to prepare coating solution.

The concentration of each ion in the coating solution is: Element Na ⁺ K ⁺ Ca ²⁺ Mg ^{2+ Cl-} HPO ₄ ^2- HCO ₄ ^- SO ₄ ^2- concentrationmmol/l 142 5.0 2.5 1.5 147.8 1.0 4.2 0.5

Preparation of nano-titanium dioxide dispersion liquid: Recipe: 5 g of nano-titanium dioxide (anatase type), 0.50 g of potassium polyacrylate, and 100 ml of coating solution.

Add nano-titanium dioxide and dispersant to 50ml of coating solution, use trishydroxyaminomethane and hydrochloric acid as buffers to adjust the pH value to about 7.3, stir, heat, and react at a constant temperature of 40°C for 2 hours, filter, wash, and finally replace the filter cake Disperse in 50ml coating liquid, carry out coating treatment again, finally obtain 50ml nano-titanium dioxide dispersion liquid.

Coating preparation: mix water, pigment/filler, dispersant, defoamer, film-forming aid, leveling agent, neutralizer and nano-titanium dioxide dispersion, adjust the pH value to 8-10, stir at high speed for 10-50min, Then grind for 30-60 minutes with a sand mill or a three-roller machine to obtain a slurry.

Add water, emulsion and defoamer to the slurry for stirring, then add a thickener, adjust the pH value to 9-10, adjust the coating to a suitable viscosity, and stir at a low speed for 30 minutes to obtain a nano-ecological coating.

Water, dispersants, pigments/fillers, defoamers, film-forming aids, leveling agents, nano-titanium dioxide, emulsions, thickeners, and neutralizers account for 35, 0.5, 39, and 0.5 mass percentages of the paint, respectively. , 2, 0.5, 1, 20, 1, 0.5 wt%.

Example 3:

Preparation of coating solution: Dissolve NaCl, NaHCO ₃ , KCl, K ₂ HPO ₄ 3H ₂ O, MgCl 6H ₂ O, CaCl ₂ , Na ₂ SO ₄ in water to prepare coating solution.

The concentration of each ion in the coating solution is: Element Na ⁺ K ⁺ Ca ²⁺ Mg ^{2+ Cl-} HPO ₄ ^2- HCO ₄ ^- SO ₄ ^2- concentrationmmol/l 142 5.0 2.5 1.5 147.8 1.0 4.2 0.5

Preparation of nano-titanium dioxide dispersion: recipe: 10 g of nano-titanium dioxide (anatase type), 1.00 g of potassium polyacrylate, and 200 ml of coating solution.

Add nano-titanium dioxide and dispersant to 100ml of coating solution, use trishydroxyaminomethane and hydrochloric acid as buffer to adjust the pH value to about 7.3, stir, heat, react at a constant temperature of 40°C for 2 hours, filter, wash, and finally filter the cake again Disperse in 100ml of coating liquid, carry out coating treatment again, finally obtain 100ml of nano-titanium dioxide dispersion liquid.

Coating preparation: mix water, pigment/filler, dispersant, defoamer, film-forming aid, leveling agent, neutralizer and nano-titanium dioxide dispersion, adjust the pH value to 8-10, stir at high speed for 10-50min, Then grind for 30-60 minutes with a sand mill or a three-roller machine to obtain a slurry.

Add water, emulsion and defoamer to the slurry for stirring, then add a thickener, adjust the pH value to 9-10, adjust the coating to a suitable viscosity, and stir at a low speed for 30 minutes to obtain a nano-ecological coating.

The mass percentages of water, dispersant, pigment/filler, defoamer, film-forming aid, leveling agent, nano-titanium dioxide, emulsion, thickener, neutralizer, etc. in the coating are 35, 0.5, 38, 0.5, 2, 0.5, 2, 20, 1, 0.5 wt%.

Example 4:

Preparation of nano-titanium dioxide dispersion: recipe: 5 g of nano-titanium dioxide (anatase type), 0.50 g of potassium polyacrylate, and 50 ml of water.

Add nanometer titanium dioxide and dispersant into water for dispersion to obtain nanometer titanium dioxide dispersion liquid.

Coating preparation: mix water, pigment/filler, dispersant, defoamer, film-forming aid, leveling agent, neutralizer and nano-titanium dioxide dispersion, adjust the pH value to 8-10, stir at high speed for 10-50min, Then grind for 30-60 minutes with a sand mill or a three-roller machine to obtain a slurry.

Add water, emulsion and defoamer to the slurry for stirring, then add a thickener, adjust the pH value to 9-10, adjust the coating to a suitable viscosity, and stir at a low speed for 30 minutes to obtain a nano-ecological coating.

The mass percentages of water, dispersant, pigment/filler, defoamer, film-forming aid, leveling agent, nano-titanium dioxide, emulsion, thickener, neutralizer, etc. in the coating are 35, 0.5, 39, 0.5, 2, 0.5, 1, 20, 1, 0.5 wt%.

Nano-ecological coating weather resistance test

The weather resistance test of nano-coatings is carried out according to GB/T1865-1997 "Paints and Varnishes Artificial Weathering and Artificial Radiation Exposure (Filtered Xenon Arc Radiation)", and the results are evaluated according to GB/T1766-1995 "Paints and Varnishes Coating Aging Evaluation Method", wherein the evaluation of discoloration grade is carried out according to 4.2.2 in GB/T 1766-1995, and the measurement results are shown in Table 1.

The weather resistance test result of table 1 nano coating project Example 1 Example 2 Example 3 Example 4 aging time 600h 600h 600h 600h chalking Level 1 Level 1 Level 1 level 2 discoloration Level 1 Level 1 Level 1 level 2 Appearance changes No change in paint film No change in paint film No change in paint film No change in paint film

Degradation performance test of nano-ecological coatings on organic pollutants:

The degradation performance of nano-coatings on formaldehyde was tested in a self-made quartz reactor under the irradiation of ultraviolet lamps, and its photocatalytic performance and photodegradation efficiency on air pollutants were evaluated. The test results are shown in Table 2.

Antibacterial performance test of nano-ecological coatings:

Since the antibacterial test standards for antibacterial coatings in my country are still being formulated, hereby refer to JC/T 897-2002 "Antibacterial Ceramic Products Antibacterial Properties" and QB/T 2591-2003 "Antibacterial Plastic Antibacterial Performance Test Methods and Antibacterial Effects" test preparation Antimicrobial properties of coatings. Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria) were used as test bacteria, the bacteria were cultured by the contact method, and the viable bacteria rate was calculated. The test results are shown in Table 2.

Photocatalytic performance and antibacterial performance test result of table 2 coating project Example 1 Example 2 Example 3 Example 4 Formaldehyde degradation rate (%) 43.2 55.7 66.9 40.0 Antibacterial rate (%) 93.2 94.9 97.5 90.6

Claims (4)

1, a kind of nanometer ecological paint, it is characterized in that adopting following steps to make: (1) Preparation of coating solution: dissolve NaCl, NaHCO ₃ , KCl, K ₂ HPO ₄ 3H ₂ O, MgCl 6H ₂ O, CaCl ₂ , Na ₂ SO ₄ in water to prepare coating solution; The concentration of each ion in the coating solution is: Composition Na ⁺ K ⁺ Ca ²⁺ Mg ²⁺ Cl HPO ₄ ^2- HCO ₄ ^- SO ₄ ^2- Concentration mmol/l 142 5.0 2.5 1.5 147.8 1.0 4.2 0.5 (2) Preparation of nano-titanium dioxide dispersion: add nano-titanium dioxide and dispersant to the coating solution, use trishydroxyaminomethane and hydrochloric acid as buffers to adjust the pH value to about 7.3, stir, heat, and react at a constant temperature of 40°C for 2 hours. Filtrating, washing, and finally redispersing the filter cake into water to obtain a nano-titanium dioxide dispersion; the additions of nano-titanium dioxide and dispersant are respectively 5-20wt% and 0.1-2wt% of the dispersion; (3) Coating preparation: mix water, pigment/filler, dispersant, defoamer, film-forming aid, leveling agent, neutralizer and nano-titanium dioxide dispersion, adjust the pH value to 8-10, stir at high speed for 10 -50min, then grind for 30-60min with a sand mill or three-roller machine to obtain a slurry; add water, emulsion, and defoamer to the slurry for stirring, then add a thickener to adjust the pH value to 9-10, and The paint is adjusted to a suitable viscosity, stirred at a low speed for 30 minutes, and finally a nano-ecological paint is obtained; water in the paint, dispersant, pigment/filler, defoamer, film-forming aid, leveling agent, nano-titanium dioxide, emulsion, thickener, medium The mass percent of the blending agent in the paint is 20-45, 0.1-2, 20-45, 0.1-2, 1-5, 0.1-2, 0.5-5, 10-30, 0.2-4, 0.1-2 wt%. 2. nanometer ecological paint according to claim 1 is characterized in that: in step (2), adopt mechanical force dispersion method, ultrasonic dispersion method or chemical dispersion method to disperse, the dispersant that adopts is polyacrylic acid salt, One or more of polyphosphates and polyethylene glycol. 3. The nano-ecological coating according to claim 1, characterized in that: the surface of the nano-titanium dioxide particles forms a porous hydroxyapatite film in the coating solution. 4. The nano-ecological coating according to claim 3, characterized in that: the coating rate of the nano-titanium dioxide particle surface is 0.1-99%.