A high performance titanium dioxide pigment and preparation method thereof

Abstract

The present application relates to the technical field of chemical raw materials, and more specifically, it relates to a high-performance titanium dioxide pigment and a preparation method thereof. A high-performance titanium dioxide pigment comprises a titanium dioxide base material, the titanium dioxide base material is coated with a silicon oxide coating layer on the outside, the silicon oxide coating layer is coated with an aluminum oxide film layer on the outside, and the aluminum oxide film layer is coated with an organic film layer on the outside; the titanium dioxide base material is composed of a mixture of two unsurface-treated chloride rutile titanium dioxide semi-finished products; the silicon oxide coating layer is prepared by reacting the titanium dioxide base material with a silicate solution; the aluminum oxide film layer is prepared by reacting the silicon oxide coating layer with an aluminate solution; the organic film layer is prepared by reacting the silicon oxide film layer with an organic treatment agent; and the organic treatment agent is a polyol and / or silicone. The high-performance titanium dioxide pigment of the present application not only has good blue phase, optical properties and weather resistance, but also has good dispersibility and temperature resistance and anti-yellowing properties in plastic resin systems.

Description

Technical Field

[0001] The present application relates to the technical field of chemical raw materials, and more specifically, to a high-performance titanium dioxide pigment and a preparation method thereof. Background Art

[0002] Titanium dioxide, also known as titanium dioxide, is a non-toxic, optimal whiteness and brightness white inorganic pigment. It has stable chemical properties, excellent hiding power, strong coloring ability and high melting point. It is widely used in coatings, plastics, inks, ceramics, papermaking industry, cosmetics and other industries.

[0003] However, nano-titanium dioxide has a high surface energy and contains polar groups called hydroxyl groups on its surface, so it is easy to aggregate due to polar adsorption or moisture absorption. Therefore, when titanium dioxide is added as an additive to raw materials for preparing plastics, there is a problem of uneven dispersion of titanium dioxide in the raw materials. Summary of the invention

[0004] In order to improve the dispersibility of titanium dioxide, the present application provides a high-performance titanium dioxide pigment and a preparation method thereof.

[0005] In the first aspect, the present application provides a high-performance titanium dioxide pigment, which adopts the following technical solution:

[0006] A high-performance titanium dioxide pigment comprises a titanium dioxide base material, the titanium dioxide base material is coated with a silicon oxide coating layer on the outside, the silicon oxide coating layer is coated with an aluminum oxide film layer on the outside, and the aluminum oxide film layer is coated with an organic film layer on the outside; the titanium dioxide base material is composed of a mixture of two chloride-process rutile titanium dioxide semi-finished products that have not been surface-treated; the silicon oxide coating layer is prepared by reacting the titanium dioxide base material with a silicate solution;

[0007] The aluminum oxide film layer is prepared by reacting the silicon oxide coating layer with an aluminate solution;

[0008] The organic film layer is prepared by reacting a silicon oxide film layer with an organic treatment agent;

[0009] The organic treatment agent is polyol and / or organosilicon.

[0010] By adopting the above technical scheme, on the one hand, the high CBU (carbon black base) titanium dioxide semi-finished products produced by two different production systems are mixed, and the obtained titanium dioxide base material has a high proportion of particles close to spherical shape, a small particle size, a narrow particle size distribution, and good optical properties. On the other hand, the silicon oxide film layer, the aluminum oxide film layer and the organic film layer are coated on the titanium dioxide base material in sequence to coat the titanium dioxide particles, thereby reducing the agglomeration of the titanium dioxide particles, not only improving the weather resistance, optical properties and blue base phase of the titanium dioxide pigment, but also improving the compatibility, dispersibility and temperature resistance and anti-yellowing properties of the titanium dioxide pigment in the plastic resin system.

[0011] In a second aspect, the present application provides a method for preparing a high-performance titanium dioxide pigment, using the following technical solution:

[0012] A method for preparing a high-performance titanium dioxide pigment comprises the following preparation steps:

[0013] S1: mixing two unsurface-treated chloride-process rutile titanium dioxide semi-finished products to obtain a titanium dioxide base material; adding desalted water to the titanium dioxide base material, beating the mixture to obtain a titanium dioxide slurry;

[0014] S2: adjusting the pH value of the titanium dioxide slurry to 9.2-10.5, then adding a dispersant, stirring and mixing, to obtain a dispersed titanium dioxide slurry;

[0015] S3: grinding the dispersed titanium dioxide slurry, cyclone classification, adding desalted water, adjusting the pH value to 10.0-11.0, stirring and mixing, and obtaining a titanium dioxide slurry desalted water solution;

[0016] S4: adding the silicate solution to the desalted water solution of the titanium dioxide slurry, stirring and mixing to obtain a silicate titanium dioxide mixed slurry, adjusting the pH value of the silicate titanium dioxide mixed slurry to 7.0-7.2, and aging to obtain titanium dioxide coated with a silicon oxide coating layer;

[0017] S5: adding the aluminate solution to the titanium dioxide coated with the silicon oxide coating layer, stirring and mixing to obtain aluminate titanium dioxide mixed slurry, adjusting the pH value of the aluminate titanium dioxide mixed slurry to 6.8-7.2, and aging to obtain titanium dioxide coated with the aluminum oxide coating layer;

[0018] S6: washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, and then steam-crushing the titanium dioxide and spraying an organic treatment agent to obtain a high-performance titanium dioxide pigment coated with an organic coating layer;

[0019] The organic treatment agent is polyol and / or organosilicon.

[0020] By adopting the above technical scheme, first, the titanium dioxide base material obtained by mixing the high CBU (carbon black background) titanium dioxide semi-finished products produced by two different production systems is dispersed by beating with desalted water, and then ground, dispersed and graded, which can open the agglomerates in the titanium dioxide base material, remove large particles, and obtain a narrower particle size distribution range. Therefore, the obtained titanium dioxide pigment has good blue phase and optical properties. Secondly, the titanium dioxide base material is coated with silicate and aluminate in sequence. Under the above preparation steps, a dense silicon oxide film layer and a dense and loose aluminum oxide film layer combined with each other can be formed on the surface of the titanium dioxide base material, which can not only maintain the blue phase required by the obtained titanium dioxide pigment, but also improve its weather resistance. Finally, the coated titanium dioxide base material is filtered, washed and dried, and then pulverized by a jet mill and coated with an organic treatment agent, which enhances the compatibility, dispersibility and temperature resistance and yellowing resistance of the obtained titanium dioxide pigment in the plastic system.

[0021] Therefore, the titanium dioxide pigment prepared by the preparation method of the present application has a blue base phase in the plastic resin system, and has good dispersibility, high weather resistance and heat resistance and anti-yellowing properties, and can meet the performance requirements of the plastic resin system.

[0022] Preferably, in S1, the weight ratio of the two unsurface-treated chloride-process rutile titanium dioxide semi-finished products is 5:5 or 4:6 or 6:4.

[0023] By adopting the above technical solution, the two semi-finished products are mixed according to the above weight ratio, and the obtained titanium dioxide base material is subjected to pulping dispersion, grinding treatment and cyclone classification treatment, which is conducive to obtaining a titanium dioxide pigment with a blue phase and better optical properties.

[0024] Preferably, in S2, the dispersant is one or both of phosphate and silicate.

[0025] Preferably, in S2, the dispersant is one or two of an aqueous solution of sodium hexametaphosphate and an aqueous solution of sodium silicate.

[0026] Preferably, in S2, the amount of the dispersant added is 0.2-0.5% by weight of the titanium dioxide base material based on the effective ingredients of the dispersant.

[0027] Preferably, in S2, the dispersant is a sodium silicate aqueous solution, and the concentration of the sodium silicate aqueous solution is 180-230 g / l in terms of silicon dioxide.

[0028] Preferably, in S2, the dispersant is a sodium silicate aqueous solution, and the concentration of the sodium silicate aqueous solution is 180-230 g / l in terms of silicon dioxide.

[0029] By adopting the above technical scheme, the above two kinds of dispersion on the titanium dioxide base material are better, which can effectively reduce the agglomeration of the titanium dioxide base material, facilitate grinding treatment and cyclone classification treatment, and obtain a titanium dioxide slurry desalted water solution with a narrow particle size range, which is beneficial to improve the coating effect of silicate, aluminate and organic treatment agent on the titanium dioxide base material, and obtain a titanium dioxide pigment with a blue phase and better optical properties.

[0030] Preferably, in S3, the dispersed titanium dioxide slurry is ground and subjected to cyclone classification to obtain a titanium dioxide particle size D90 of 0.15-0.25 μm.

[0031] By adopting the above technical solution, the titanium dioxide slurry is ground and then subjected to cyclone classification to obtain the particle size within the above narrow particle size range, which can effectively improve the optical properties of the obtained titanium dioxide pigment.

[0032] Preferably, in S4, the amount of the silicate solution added is 0.6-1.0% by weight of the titanium dioxide base material based on the effective ingredients of the silicate solution.

[0033] By adopting the above technical solution, adding the above silicate solution into the desalted water solution of titanium dioxide slurry, under the condition of pH value of 7.0-7.2, it is beneficial to form a dense silicon oxide film layer on the surface of titanium dioxide, thereby improving the weather resistance of the obtained titanium dioxide pigment.

[0034] Preferably, in S4, a silicate solution is added to a desalted water solution of titanium dioxide slurry at a temperature of 75-85°C, and after stirring and mixing, a silicate titanium dioxide mixed slurry is obtained, and an inorganic acid aqueous solution with a mass fraction of 8-15% is uniformly added to the silicate titanium dioxide mixed slurry within 90-150 minutes, and the pH value of the silicate titanium dioxide mixed slurry is adjusted to 7.0-7.2, and matured to obtain titanium dioxide coated with a silicon oxide coating layer.

[0035] Preferably, in S4, the inorganic acid in the inorganic acid aqueous solution is any one of sulfuric acid, hydrochloric acid and nitric acid.

[0036] By adopting the above technical scheme, an inorganic acid aqueous solution with a mass fraction of 8-15% is uniformly added to a mixed slurry at 75-85°C within 90-150 minutes, and the pH value of the mixed slurry is adjusted to 7.0-7.2, which is conducive to the reaction of silicate with the surface of titanium dioxide and forms a dense aluminum oxide film layer on the surface of titanium dioxide, which not only improves the weather resistance of the obtained titanium dioxide pigment, but also has good optical properties.

[0037] Preferably, in S5, the amount of the aluminate solution added is 0.7-1.2% by weight of the titanium dioxide base material based on the effective ingredients of the aluminate solution.

[0038] Preferably, in S5, the aluminate solution is a sodium aluminate solution, and the concentration of the sodium aluminate solution is 175-220 g / l in terms of alumina.

[0039] Preferably, in S5, an aluminate solution is added to titanium dioxide coated with a silicon oxide coating layer within 50-90 minutes, and after stirring and mixing, an aluminate titanium dioxide mixed slurry is obtained, and a sulfate solution is added to the aluminate titanium dioxide mixed slurry, and the pH value of the aluminate solution mixed titanium dioxide slurry is adjusted to be in the range of 6.8-7.2, and ripened to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0040] By adopting the above technical scheme, the aluminate solution of the above concentration is first added to the titanium dioxide coated with the silicon oxide coating layer, and then the sulfate solution of the above concentration is added to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast. A layer of aluminum oxide film from dense to relatively loose can be coated on the surface of the titanium dioxide coated with the silicon oxide coating layer, which is beneficial to further improve the weather resistance and optical properties of the obtained titanium dioxide pigment.

[0041] Preferably, in S6, the organic treatment agent is one or more of trimethylolpropane, trimethylolethane, silicone oil and silane coupling agent.

[0042] By adopting the above technical scheme, when the titanium dioxide coated with the aluminum oxide film layer is subjected to steam flow pulverization, the above-mentioned type of polyol and / or silicone is sprayed on the titanium dioxide, and a hydrophobic organic coating layer is formed on the surface of the titanium dioxide coated with the aluminum oxide film layer, which not only improves the compatibility of the titanium dioxide pigment with the plastic resin system, but also improves its heat resistance and yellowing resistance.

[0043] In summary, this application has the following beneficial effects:

[0044] 1. Mix high CBU (carbon black base) titanium dioxide semi-finished products produced by two different production systems to form a titanium dioxide base material, and then coat the titanium dioxide base material with a silicon oxide film layer, an aluminum oxide film layer and an organic film layer in sequence. The resulting titanium dioxide pigment not only has good weather resistance, temperature resistance, anti-yellowing and dispersibility, but also has good blue phase and optical properties;

[0045] 2. In the preparation method of the present application, titanium dioxide with a narrow particle size distribution range is obtained by pulping, dispersing, grinding and cyclone classification of the titanium dioxide base material, and having good blue phase and optical properties; then, by adding silicate and aluminate, controlling the time limit, temperature and pH value of the addition of silicate and aluminate, and spraying an organic treatment agent during steam pulverization, it is beneficial for the silicate to form a dense silicon oxide film on the surface of the titanium dioxide, and the aluminate to form a dense and loose aluminum oxide film on the surface of the silicon oxide film layer, and the organic treatment agent to form a hydrophobic organic film on the surface of the aluminum oxide film layer, which improves the weather resistance, temperature resistance and yellowing resistance, compatibility and optical properties of the titanium dioxide pigment without affecting the blue phase of the titanium dioxide pigment. DETAILED DESCRIPTION

[0046] The present application is further described in detail below with reference to the embodiments.

[0047] The raw materials used in the examples and comparative examples of the present application are commercially available unless otherwise specified below.

[0048] In the embodiment of the present application, the unsurface-treated chloride-process rutile titanium dioxide semi-finished product A is commercially available, has a rutile content of 99.9%, and a carbon black base color of 14.

[0049] Type B is a chloride process rutile titanium dioxide semi-finished product without surface treatment, which is commercially available, has a rutile content of 99.8% and a carbon black base color of 15.

[0050] Performance Testing

[0051] The high-performance titanium dioxide pigment obtained in the examples of the present application and the titanium dioxide pigment obtained in the comparative examples were used as samples to be tested, and the color space, temperature resistance, yellowing resistance and weather resistance of the samples to be tested were tested, and the color space, whiteness, yellowing and filtration pressure value of the plastic products made of the samples to be tested were tested. The testing method is as follows:

[0052] Color space detection of the sample to be tested: After the sample to be tested is pressed into a cake by a manual cake press, the L value and b value are measured by a CM-2300d spectrophotometer, where the L value refers to the brightness of the titanium dioxide powder, and the higher the L value, the better; the b value refers to the blue-yellow index of the titanium dioxide powder, and the lower the b value, the bluer the hue of the titanium dioxide, and the higher the b value, the yellower the hue of the titanium dioxide.

[0053] Heat resistance and anti-yellowing test: Use CM-2300d spectrophotometer to detect the initial color difference of the sample to be tested, recorded as ΔE0, then place the sample to be tested in an electric drying oven at 200℃ and heat for 20min. Take out the sample and cool it to room temperature (20-25℃), then detect the color difference, recorded as ΔE1; use the same method to measure the color difference of the sample to be tested after heating at 240℃ and 280℃ for 20min and cooling to room temperature, recorded as ΔE2 and ΔE3, and calculate the difference between the color difference ΔE3 of the sample to be tested after heating at 280℃ and the initial color difference ΔE0, recorded as ΔE.

[0054] Weather resistance test: Referring to the acid dissolution method, after the sample to be tested and the hydrochloric acid aqueous solution are stirred and mixed, the spectrophotometer CM-2300d is used to detect the spectrophotometer. The smaller the spectrophotometer, the less the titanium dioxide is decomposed in the hydrochloric acid aqueous solution, indicating that the weather resistance of titanium dioxide is higher.

[0055] Color space, whiteness and yellowing detection of plastic products: 2g of the sample to be tested is added to 98g of PP resin, and the mixture is stirred for 5 minutes to obtain a plastic mixture; the plastic mixture is plated by a HTW-500x2 horizontal injection molding machine to obtain a plastic product, and the color space, whiteness value (WI) and yellowing index (YI) of the obtained plastic product are detected by a CM-2300d spectrophotometer when the thickness is 2mm. The larger the yellowing index YI, the yellower the plastic product.

[0056] Filtration pressure value detection: The sample to be tested and linear low-density polyethylene are added to a two-roll mill for melting and mixing to form a 70% concentration masterbatch. The 0% concentration masterbatch is diluted to a mixture containing 8% of the sample to be tested. The filtration pressure value (FPV) of the mixture is detected by a single-screw extruder. The smaller the filtration pressure value (FPV) value, the better the dispersion of the sample to be tested in the linear low-density polyethylene.

[0057] Example

[0058] Example 1

[0059] A high-performance titanium dioxide pigment comprises a titanium dioxide base material, a silicon oxide coating layer is coated on the outside of the titanium dioxide base material, an aluminum oxide film layer is coated on the outside of the silicon oxide coating layer, and an organic film layer is coated on the outside of the aluminum oxide film layer;

[0060] The titanium dioxide base material is composed of a mixture of a chloride process rutile titanium dioxide semi-finished product A without surface treatment and a chloride process rutile titanium dioxide semi-finished product B without surface treatment in a weight ratio of 4:6.

[0061] The silicon oxide coating layer is prepared by reacting a titanium dioxide base material with a silicate solution, wherein the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 0.80% by weight of silicon dioxide to the titanium dioxide base material. In the embodiment of the present application, the concentration of the sodium silicate aqueous solution is 180 g / l in terms of silicon dioxide.

[0062] The aluminum oxide film layer is prepared by the reaction of the silicon oxide coating layer and an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.8% by weight of aluminum oxide to the titanium dioxide base material. In the embodiment of the present application, the concentration of the sodium aluminate solution is 175 g / l based on aluminum oxide.

[0063] The organic film layer is prepared by reacting the silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is octyltriethoxysilane.

[0064] The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps:

[0065] S1: 400 g of type A chloride process rutile titanium dioxide semi-finished product without surface treatment and 600 g of type B chloride process rutile titanium dioxide semi-finished product without surface treatment are mixed to obtain a titanium dioxide base material; desalted water is added to the titanium dioxide base material to obtain a titanium dioxide base material desalted water solution with a mass concentration of 32%, and the mixture is beaten for 20 minutes to obtain a titanium dioxide slurry.

[0066] S2: adding a sodium hydroxide aqueous solution with a mass concentration of 20% to adjust the pH value of the titanium dioxide slurry to 9.8, then adding a dispersant, stirring and mixing for 30 minutes to obtain a dispersed titanium dioxide slurry.

[0067] In the embodiment of the present application, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.30% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 200 g / l in terms of silicon dioxide.

[0068] S3: Grind the dispersed titanium dioxide slurry, and after cyclone classification, obtain a titanium dioxide particle size D90 in the range of 0.15-0.25 μm; then add desalted water to obtain a titanium dioxide slurry desalted water solution with a mass concentration of 0.28%, and then adjust its pH value to 10.5, stir and mix for 30 minutes, and obtain an alkaline titanium dioxide slurry desalted water solution.

[0069] S4: Add the silicate solution into the alkaline titanium dioxide slurry desalted water solution at 80°C, stir and mix for 30 minutes to obtain a silicate titanium dioxide mixed slurry; add an inorganic acid aqueous solution with a mass concentration of 10% into the silicate titanium dioxide mixed slurry at a uniform speed in a countercurrent manner within 130 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.0 from slow to fast, and mature for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0070] In the embodiment of the present application, the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 0.8% by weight of silicon dioxide based on the weight of the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 180 g / l based on silicon dioxide; the inorganic acid aqueous solution is a hydrochloric acid aqueous solution.

[0071] S5: Add the aluminate solution to the titanium dioxide coated with a silicon oxide coating layer within 60 minutes to obtain an aluminate titanium dioxide mixed slurry; add the aluminum sulfate solution to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast, adjust the pH value of the aluminate titanium dioxide mixed slurry within the range of 6.8-7.2, mature for 30 minutes, continue to adjust the pH value of the aluminate titanium dioxide mixed slurry to 7.0, and continue to mature for 110 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0072] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.8% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 175 g / l based on alumina, and the concentration of the aluminum sulfate solution is 95 g / l based on alumina.

[0073] S6: After washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, the titanium dioxide is steam-pulverized and an organic treatment agent is sprayed into the titanium dioxide to obtain a high-performance titanium dioxide pigment coated with an organic coating layer having a carbon content of 0.30%.

[0074] In the embodiment of the present application, the organic treatment agent is a silane coupling agent, specifically octyltriethoxysilane.

[0075] Example 2

[0076] A high-performance titanium dioxide pigment comprises a titanium dioxide base material, a silicon oxide coating layer is coated on the outside of the titanium dioxide base material, an aluminum oxide film layer is coated on the outside of the silicon oxide coating layer, and an organic film layer is coated on the outside of the aluminum oxide film layer;

[0077] The titanium dioxide base material is composed of a mixture of a chloride process rutile titanium dioxide semi-finished product A without surface treatment and a chloride process rutile titanium dioxide semi-finished product B without surface treatment in a weight ratio of 5:5.

[0078] The silicon oxide coating layer is prepared by the reaction of titanium dioxide base material and silicate solution, wherein the silicate solution is sodium silicate aqueous solution, the amount of sodium silicate aqueous solution added is 0.9% by weight of silicon dioxide to titanium dioxide base material, wherein the concentration of sodium silicate aqueous solution is 200g / l based on silicon dioxide.

[0079] The aluminum oxide film layer is prepared by the reaction of the silicon oxide coating layer and an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of the sodium aluminate solution added is 0.7% by weight of the aluminum oxide to the titanium dioxide base material, wherein the concentration of the sodium aluminate solution is 200 g / l based on aluminum oxide.

[0080] The organic film layer is prepared by reacting the silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is octyltriethoxysilane.

[0081] The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps:

[0082] S1: 500 g of type A chloride process rutile titanium dioxide semi-finished product without surface treatment and 500 g of type B chloride process rutile titanium dioxide semi-finished product without surface treatment are mixed to obtain a titanium dioxide base material; desalted water is added to the titanium dioxide base material to obtain a titanium dioxide base material desalted water solution with a mass concentration of 32%, and the mixture is beaten for 20 minutes to obtain a titanium dioxide slurry.

[0083] S2: adding a sodium hydroxide aqueous solution with a mass concentration of 20% to adjust the pH value of the titanium dioxide slurry to 10.2, then adding a dispersant, stirring and mixing for 30 minutes to obtain a dispersed titanium dioxide slurry.

[0084] In the embodiment of the present application, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.35% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 190 g / l in terms of silicon dioxide.

[0085] S3: Grind the dispersed titanium dioxide slurry, and after cyclone classification, obtain a titanium dioxide particle size D85 in the range of 0.15-0.25 μm; then add desalted water to obtain a titanium dioxide slurry desalted water solution with a mass concentration of 0.26%, and then adjust the pH value to 11, stir and mix for 30 minutes, and obtain an alkaline titanium dioxide slurry desalted water solution.

[0086] S4: Add the silicate solution into the alkaline titanium dioxide slurry desalted water solution at 78°C, stir and mix for 40 minutes to obtain a silicate titanium dioxide mixed slurry; add an inorganic acid aqueous solution with a mass concentration of 10% into the silicate titanium dioxide mixed slurry at a uniform speed in a countercurrent manner within 130 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.2 from slow to fast, and mature for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0087] In the embodiment of the present application, the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 0.9% by weight of silicon dioxide to the weight of the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 200 g / l based on silicon dioxide; the inorganic acid aqueous solution is a hydrochloric acid aqueous solution.

[0088] S5: Add the aluminate solution to the titanium dioxide coated with a silicon oxide coating layer within 70 minutes to obtain an aluminate titanium dioxide mixed slurry; add the aluminum sulfate solution to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast, adjust the pH value of the aluminate titanium dioxide mixed slurry within the range of 6.8-7.2, mature for 30 minutes, continue to adjust the pH value of the aluminate titanium dioxide mixed slurry to 7.0, and continue to mature for 100 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0089] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.7% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 200 g / l based on alumina; the concentration of the aluminum sulfate solution is 105 g / l based on alumina.

[0090] S6: After washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, the titanium dioxide is steam-pulverized and an organic treatment agent is sprayed into the titanium dioxide to obtain a high-performance titanium dioxide pigment coated with an organic coating layer having a carbon content of 0.35%.

[0091] In the embodiment of the present application, the organic treatment agent is a silane coupling agent, specifically octyltriethoxysilane.

[0092] Example 3

[0093] A high-performance titanium dioxide pigment comprises a titanium dioxide base material, a silicon oxide coating layer is coated on the outside of the titanium dioxide base material, an aluminum oxide film layer is coated on the outside of the silicon oxide coating layer, and an organic film layer is coated on the outside of the aluminum oxide film layer;

[0094] The titanium dioxide base material is composed of a mixture of a chloride process rutile titanium dioxide semi-finished product A without surface treatment and a chloride process rutile titanium dioxide semi-finished product B without surface treatment in a weight ratio of 6:4.

[0095] The silicon oxide coating layer is prepared by the reaction of titanium dioxide base material and silicate solution, wherein the silicate solution is sodium silicate aqueous solution, the amount of sodium silicate aqueous solution added is 1.0% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of sodium silicate aqueous solution is 230g / l based on silicon dioxide.

[0096] The aluminum oxide film layer is prepared by the reaction of the silicon oxide coating layer and an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of the sodium aluminate solution added is 0.9% by weight of the titanium dioxide base material based on aluminum oxide, wherein the concentration of the sodium aluminate solution is 220 g / l based on aluminum oxide.

[0097] The organic film layer is prepared by reacting the silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is octyltriethoxysilane.

[0098] The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps:

[0099] S1: 600 g of type A chloride process rutile titanium dioxide semi-finished product without surface treatment and 400 g of type B chloride process rutile titanium dioxide semi-finished product without surface treatment are mixed to obtain a titanium dioxide base material; desalted water is added to the titanium dioxide base material to obtain a titanium dioxide base material desalted water solution with a mass concentration of 30%, and the mixture is beaten for 30 minutes to obtain a titanium dioxide slurry.

[0100] S2: adding a sodium hydroxide aqueous solution with a mass concentration of 20% to adjust the pH value of the titanium dioxide slurry to 9.5, then adding a dispersant, stirring and mixing for 30 minutes to obtain a dispersed titanium dioxide slurry.

[0101] In the embodiment of the present application, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.40% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 210 g / l in terms of silicon dioxide.

[0102] S3: Grind the dispersed titanium dioxide slurry, and after cyclone classification, obtain a titanium dioxide particle size D90 in the range of 0.15-0.25 μm; then add desalted water to obtain a titanium dioxide slurry desalted water solution with a mass concentration of 0.24%, and then adjust the pH value to 10.5, stir and mix for 30 minutes, and obtain an alkaline titanium dioxide slurry desalted water solution.

[0103] S4: Add the silicate solution into the alkaline titanium dioxide slurry desalted water solution at 82°C, stir and mix for 30 minutes to obtain a silicate titanium dioxide mixed slurry; add an inorganic acid aqueous solution with a mass concentration of 10% into the silicate titanium dioxide mixed slurry at a uniform speed in a countercurrent manner within 140 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.0 from slow to fast, and mature for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0104] In the embodiment of the present application, the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 1.0% by weight of silicon dioxide to the weight of the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 230 g / l based on silicon dioxide; the inorganic acid aqueous solution is a hydrochloric acid aqueous solution.

[0105] S5: Add the aluminate solution to the titanium dioxide coated with a silicon oxide coating layer within 80 minutes to obtain an aluminate titanium dioxide mixed slurry; add the aluminum sulfate solution to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast, adjust the pH value of the aluminate titanium dioxide mixed slurry within the range of 6.8-7.2, mature for 40 minutes, continue to adjust the pH value of the aluminate titanium dioxide mixed slurry to 7.0, and continue to mature for 120 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0106] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.9% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 220 g / l based on alumina; the concentration of the aluminum sulfate solution is 110 g / l based on alumina.

[0107] S6: After washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, the titanium dioxide is pulverized by steam flow and sprayed with an organic treatment agent to obtain a high-performance titanium dioxide pigment coated with an organic coating layer having a carbon content of 0.28%.

[0108] In the embodiment of the present application, the organic treatment agent is a silane coupling agent, specifically octyltriethoxysilane.

[0109] The high-performance titanium dioxide pigments obtained in Examples 1-3 of the present application were used as test samples, and the color space, temperature resistance and yellowing resistance and weather resistance of the test samples were tested. The color space, whiteness, yellowing and filtration pressure value of the plastic products made of the test samples were tested. The test results are shown in the following table:

[0110]

[0111] By analyzing the data in the above table, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 1-3 of the present application have an L value as high as 99.05-99.10, a b value of 1.22-1.25, a difference ΔE between the color difference ΔE3 after heating at 280°C and the initial color difference ΔE0 as low as 0.40-0.45, and a spectrophotometer as low as 1.28-1.41 nm after acid dissolution detection. This shows that the high-performance titanium dioxide pigments obtained in Examples 1-3 of the present application have the characteristics of good hue, high tinting power, strong heat resistance, anti-yellowing and strong weather resistance.

[0112] The plastic products prepared by using the high-performance titanium dioxide pigment obtained in Examples 1-3 of the present application have an L value of up to 97.38-97.52, a b value of 0.82-0.86, a whiteness of up to 96.25-96.41%, a yellowing index as low as 0.79-0.86, and a filtration pressure value as low as 0.089-0.105 bar / g. This shows that the high-performance titanium dioxide pigment obtained in Examples 1-3 of the present application has good dispersibility in plastics, and the plastic products prepared have high whiteness and low yellowness.

[0113] Example 4

[0114] A high-performance titanium dioxide pigment, which is different from Example 2 in that in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S2, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.20% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 180 g / l in terms of silicon dioxide.

[0115] Example 5

[0116] A high-performance titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S2, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.50% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 230 g / l in terms of silicon dioxide.

[0117] Example 6

[0118] A high-performance titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S2, the dispersant is a sodium hexametaphosphate aqueous solution, wherein the concentration of the sodium hexametaphosphate aqueous solution is 190 g / l in terms of sodium hexametaphosphate.

[0119] The high-performance titanium dioxide pigments obtained in Examples 4-6 of the present application were used as the test samples, and the color space detection was performed on the test samples. The color space and whiteness detection were performed on the plastic products made of the test samples. The test results are shown in the following table:

[0120]

[0121] By analyzing the data in the above table, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 2, 4, and 5 of the present application have an L value of up to 99.08-99.11 and a b value of 1.21-1.23. The plastic products prepared using the high-performance titanium dioxide pigments obtained in Examples 2, 4, and 5 of the present application have an L value of up to 97.49-97.53, a b value of 0.83-0.85, and a whiteness of up to 96.40-96.42%. This shows that in the preparation step S2 of the high-performance titanium dioxide pigment of the present application, the amount of dispersant added is 0.2-0.5% by weight of the effective ingredient of the dispersant to the titanium dioxide base material, and the obtained high-performance titanium dioxide pigment and the plastic products prepared have a higher blue phase and optical properties, and a higher whiteness.

[0122] By comparing and analyzing the test results of Example 2 and Example 6, it can be seen that the high-performance titanium dioxide and plastic products prepared by Example 2 using sodium silicate aqueous solution as a dispersant have a higher blue phase and optical properties, and a higher whiteness than the high-performance titanium dioxide and plastic products prepared by Example 6 using sodium hexametaphosphate aqueous solution as a dispersant.

[0123] Example 7

[0124] A high-performance titanium dioxide pigment is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, the particle size D90 of the titanium dioxide in the preparation step S3 is in the range of 0.15-0.25 μm.

[0125] The high-performance titanium dioxide pigment obtained in Example 7 of the present application was used as the sample to be tested, and the color space detection was performed on the sample to be tested, and the color space and whiteness detection were performed on the plastic product made of the sample to be tested. The test results are shown in the following table:

[0126]

[0127] Comparative analysis of the test results of Example 2 and Example 7 shows that the high-performance titanium dioxide and its products obtained in Example 7 have higher L value and whiteness value and lower b value. This shows that in the preparation method of high-performance titanium dioxide of the present application, in the preparation step S3, the dispersed slurry is ground, and after cyclone classification, the titanium dioxide particle size D90 is obtained to be 0.15-0.25 μm, which is beneficial to improving the blue phase, optical properties and whiteness of the obtained high-performance titanium dioxide and plastic products.

[0128] Example 8

[0129] A high-performance titanium dioxide pigment, which is different from Example 2 in that the silicon oxide coating layer is prepared by reacting a titanium dioxide base material with a silicate solution, wherein the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 0.6% by weight of the titanium dioxide base material based on silicon dioxide.

[0130] Example 9

[0131] A high-performance titanium dioxide pigment, which is different from Example 2 in that the silicon oxide coating layer is prepared by reacting a titanium dioxide base material with a silicate solution, wherein the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 1.0% by weight of silicon dioxide to the titanium dioxide base material.

[0132] The high-performance titanium dioxide pigments obtained in Examples 8 and 9 of the present application were used as test samples, and weather resistance tests were performed on the test samples. The test results are shown in the following table:

[0133]

[0134] By analyzing the data in the above table, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 2, 8, and 9 of the present application have a spectrophotometry as low as 1.28-1.34 nm after acid dissolution detection. This shows that in the preparation step S2 of the high-performance titanium dioxide pigment of the present application, the amount of the dispersant added is 0.6-1.0% by weight of the effective component of the dispersant to the titanium dioxide base material, and the obtained high-performance titanium dioxide pigment and the plastic product prepared therefrom have high weather resistance.

[0135] Example 10

[0136] A high-performance titanium dioxide pigment, which is different from Example 2 in that in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S4, a silicate solution is added to a 75° C. alkaline titanium dioxide slurry desalted water solution, and stirred and mixed for 30 minutes to obtain a silicate titanium dioxide mixed slurry.

[0137] Embodiment 11

[0138] A high-performance titanium dioxide pigment, which is different from Example 2 in that in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S4, a silicate solution is added to an alkaline titanium dioxide slurry desalted water solution at 85° C., and stirred and mixed for 30 minutes to obtain a silicate titanium dioxide mixed slurry.

[0139] Example 12

[0140] A high-performance titanium dioxide pigment, which is different from Example 2 in that in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S4, a silicate solution is added to a 40° C. alkaline titanium dioxide slurry desalted water solution, and stirred and mixed for 30 minutes to obtain a silicate titanium dioxide mixed slurry.

[0141] The high-performance titanium dioxide pigments obtained in Examples 10, 11, and 12 of the present application were used as test samples, and weather resistance tests were performed on the test samples. The test results are shown in the following table:

[0142]

[0143] By analyzing the data in the above table, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 2, 10, and 11 of the present application have a spectrophotometry as low as 1.27-1.30 nm after acid dissolution detection. This shows that in the preparation method of the high-performance titanium dioxide pigment, in step S4, adding the silicate solution to the alkaline slurry desalted water solution at 75-85°C can improve the weather resistance of the obtained high-performance titanium dioxide pigment.

[0144] Embodiment 13

[0145] A high-performance titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S4, an inorganic acid aqueous solution with a mass concentration of 15% is added to a silicate titanium dioxide mixed slurry in a countercurrent manner at a uniform speed within 90 minutes, and the pH value of the silicate titanium dioxide mixed slurry is slowly adjusted from slow to fast to 7.2, and matured for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0146] Embodiment 14

[0147] A high-performance titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, in the preparation step S4, an inorganic acid aqueous solution with a mass concentration of 8% is added to a silicate titanium dioxide mixed slurry in a countercurrent manner at a uniform speed within 150 minutes, and the pH value of the silicate titanium dioxide mixed slurry is slowly adjusted from slow to fast to 7.2, and matured for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0148] The high-performance titanium dioxide pigments obtained in Examples 13 and 14 of the present application were used as test samples, and weather resistance tests were performed on the test samples. The test results are shown in the following table:

[0149]

[0150] By analyzing the data in the above table, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 2, 13, and 14 of the present application have a spectrophotometry as low as 1.28-1.30 nm after acid dissolution detection. This shows that in the preparation method of the high-performance titanium dioxide pigment, in step S4, an inorganic acid aqueous solution with a mass concentration of 8-15% is added to the silicate titanium dioxide mixed slurry in a countercurrent manner at a uniform speed within 90-150 minutes, and the pH value of the silicate titanium dioxide mixed slurry is slowly adjusted from slow to fast to 7.0-7.2, which can improve the weather resistance of the obtained high-performance titanium dioxide pigment.

[0151] The high-performance titanium dioxide obtained in Examples 8-14 was used as the test sample, and the color space detection was performed on the test sample, and the color space and whiteness detection were performed on the plastic products made of the test sample. The test results showed that the color space and whiteness test results of the test sample and its plastic product were similar to those of Example 2. This shows that in the preparation method of the high-performance titanium dioxide pigment, in step S4, silicon oxide and aluminum oxide are coated on the surface of titanium dioxide, which can improve the weather resistance of the high-performance titanium dioxide pigment without affecting the blue phase required by the final high-performance titanium dioxide pigment and its plastic product.

[0152] Embodiment 15

[0153] A high-performance titanium dioxide pigment, which is different from Example 2 in that the aluminum oxide film layer is obtained by reacting a silicon oxide coating layer with an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 1.2% by weight of the aluminum oxide to the titanium dioxide base material.

[0154] In the above-mentioned method for preparing high-performance titanium dioxide pigment, the preparation step S5 is:

[0155] The aluminate solution is added to the titanium dioxide coated with a silicon oxide coating layer within 90 minutes to obtain an aluminate titanium dioxide mixed slurry; the aluminum sulfate solution is added to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast, the pH value of the aluminate solution mixed titanium dioxide slurry is adjusted to be in the range of 6.8-7.2, and the slurry is aged for 30 minutes, and the pH value of the aluminate solution mixed titanium dioxide slurry is continuously adjusted to 7.0, and the slurry is aged for 100 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0156] In the examples of the present application, the concentration of the aluminum sulfate solution is 110 g / l in terms of aluminum oxide.

[0157] Example 16

[0158] A high-performance titanium dioxide pigment, which is different from Example 2 in that the aluminum oxide film layer is prepared by reacting a silicon oxide coating layer with an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 1.0% by weight of the aluminum oxide to the titanium dioxide base material.

[0159] In the above-mentioned method for preparing high-performance titanium dioxide pigment, the preparation step S5 is:

[0160] The aluminate solution is added to the titanium dioxide coated with a silicon oxide coating layer within 50 minutes to obtain an aluminate titanium dioxide mixed slurry; the aluminum sulfate solution is added to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast, the pH value of the aluminate solution mixed titanium dioxide slurry is adjusted to be in the range of 6.8-7.2, and the slurry is aged for 30 minutes, and the pH value of the aluminate solution mixed titanium dioxide slurry is continuously adjusted to 7.0, and the slurry is further aged for 100 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0161] In the examples of the present application, the concentration of the aluminum sulfate solution is 95 g / l in terms of aluminum oxide.

[0162] The high-performance titanium dioxide pigments obtained in Examples 15 and 16 of the present application were used as test samples, and the color space and weather resistance tests were performed on the test samples. The color space, whiteness and yellowing tests were performed on the plastic products made of the test samples. The test results are shown in the following table:

[0163]

[0164]

[0165] By analyzing the data in the above table, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 2, 15, and 16 of the present application have an L value of up to 99.08-99.13, a b value of 1.20-1.24, and after acid dissolution detection, the spectrophotometry is as low as 1.25-1.34nm. The plastic products prepared using the high-performance titanium dioxide pigments obtained in Examples 2, 15, and 16 of the present application have an L value of up to 97.49-97.55, a b value of 0.81-0.86, a whiteness of up to 96.39-96.45%, and a yellowing index as low as 0.81-0.85.

[0166] This shows that in the preparation method of the high-performance titanium dioxide pigment of the present application, in the preparation step S5, the amount of aluminum silicate solution added and the acceleration method and speed of the sulfate solution are adopted, and the obtained high-performance titanium dioxide pigment has good hue, high tinting power and strong weather resistance. At the same time, the plastic product made of the obtained high-performance titanium dioxide pigment has good hue, high whiteness and low yellowness.

[0167] Embodiment 17

[0168] A high-performance titanium dioxide pigment, which is different from Example 2 in that the organic film layer is prepared by reacting a silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is polydimethylsiloxane, model JN-201, purchased from Shandong Juneng Chemical Co., Ltd.

[0169] Embodiment 18

[0170] A high-performance titanium dioxide pigment, which is different from Example 2 in that the organic film layer is prepared by reacting a silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is composed of trimethylolpropane and octyltriethoxysilane mixed in a weight ratio of 1:1.

[0171] The high-performance titanium dioxide pigments obtained in Examples 17 and 18 of the present application were used as test samples, and the heat resistance and yellowing resistance test was performed on the test samples. The filtration pressure value test was performed on the plastic products made of the test samples. The test results are shown in the following table:

[0172]

[0173] Comparative analysis of the test results of Examples 2, 17, and 18 shows that the high-performance titanium dioxide pigment obtained in Example 18 has a smaller ΔE value and a smaller filtration pressure value. This indicates that in the total raw materials for preparing the high-performance titanium dioxide pigment, the organic treatment agent configured with trimethylolpropane and a silane coupling agent is used to coat the silicon oxide film layer, which can improve the heat resistance and yellowing resistance of the obtained high-performance titanium dioxide pigment as well as its compatibility and dispersibility in plastic products.

[0174] Comparative Example

[0175] Comparative Example 1

[0176] A titanium dioxide pigment comprises a titanium dioxide base material, the titanium dioxide base material is coated with a silicon oxide coating layer on the outside, the silicon oxide coating layer is coated with an aluminum oxide film layer on the outside, and the aluminum oxide film layer is coated with an organic film layer on the outside;

[0177] The titanium dioxide base material is a type A chloride-processed rutile titanium dioxide semi-finished product without surface treatment.

[0178] The silicon oxide coating layer is prepared by the reaction of titanium dioxide base material and silicate solution, wherein the silicate solution is sodium silicate aqueous solution, the amount of sodium silicate aqueous solution added is 1.0% by weight of silicon dioxide to titanium dioxide base material, wherein the concentration of sodium silicate aqueous solution is 200g / l based on silicon dioxide.

[0179] The aluminum oxide film layer is prepared by the reaction of the silicon oxide coating layer and an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of the sodium aluminate solution added is 0.3% by weight of the aluminum oxide to the titanium dioxide base material, wherein the concentration of the sodium aluminate solution is 200 g / l based on aluminum oxide.

[0180] The organic film layer is prepared by reacting the silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is octyltriethoxysilane.

[0181] The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps:

[0182] S1: 1000 g of type A unsurface-treated chloride rutile titanium dioxide semi-finished product is mixed to obtain a titanium dioxide base material; deionized water is added to the titanium dioxide base material to obtain a desalted water solution of the titanium dioxide base material with a mass concentration of 30%, and the solution is beaten for 30 minutes to obtain a titanium dioxide slurry.

[0183] S2: adding a sodium hydroxide aqueous solution with a mass concentration of 20% to adjust the pH value of the titanium dioxide slurry to 9.5, then adding a dispersant, stirring and mixing for 30 minutes to obtain a dispersed titanium dioxide slurry.

[0184] In the comparative example of the present application, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.30 by weight based on silicon dioxide to titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 190 g / l based on silicon dioxide.

[0185] S3: Grind the dispersed titanium dioxide slurry to a particle size of 0.15-0.25 μm, and then add deionized water to obtain a titanium dioxide slurry aqueous solution with a mass concentration of 0.28%.

[0186] S4: Add the silicate solution into the aqueous solution of titanium dioxide slurry at 60°C, stir and mix for 40 minutes to obtain a silicate titanium dioxide mixed slurry; add the aluminum sulfate aqueous solution to the silicate titanium dioxide mixed slurry at a uniform speed in a countercurrent manner within 100 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.0, and mature for 40 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0187] In the embodiment of the present application, the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 1.0% by weight of silicon dioxide to the weight of titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 200 g / l in terms of silicon dioxide, and the concentration of the aluminum sulfate aqueous solution is 105 g / l in terms of aluminum oxide.

[0188] S5: Add the aluminate solution to the titanium dioxide coated with a silicon oxide coating layer within 30 minutes, and at the same time, add the aluminum sulfate solution in a downstream manner to obtain an aluminate titanium dioxide mixed slurry with a pH value of 6.8, mature for 30 minutes, continue to adjust the pH value of the aluminate titanium dioxide mixed slurry to 7.0, and continue to mature for 100 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0189] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.3% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 200 g / l based on alumina; the concentration of the aluminum sulfate solution is 105 g / l based on alumina.

[0190] S6: After washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, the titanium dioxide is pulverized by steam flow and sprayed with an organic treatment agent to obtain a high-performance titanium dioxide pigment coated with an organic coating layer having a carbon content of 0.20%.

[0191] In the embodiment of the present application, the organic treatment agent is a silane coupling agent, specifically octyltriethoxysilane.

[0192] Comparative Example 2

[0193] A titanium dioxide pigment comprises a titanium dioxide base material, the titanium dioxide base material is coated with a silicon oxide coating layer on the outside, the silicon oxide coating layer is coated with an aluminum oxide film layer on the outside, and the aluminum oxide film layer is coated with an organic film layer on the outside;

[0194] The titanium dioxide base material is a type B chloride-processed rutile titanium dioxide semi-finished product without surface treatment.

[0195] The silicon oxide coating layer is prepared by the reaction of titanium dioxide base material and silicate solution, wherein the silicate solution is sodium silicate aqueous solution, the amount of sodium silicate aqueous solution added is 0.8% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of sodium silicate aqueous solution is 200g / l based on silicon dioxide.

[0196] The aluminum oxide film layer is prepared by the reaction of the silicon oxide coating layer and an aluminate solution, wherein the aluminate solution is a sodium aluminate solution, and the amount of the sodium aluminate solution added is 0.5% by weight of aluminum oxide to the titanium dioxide base material, wherein the concentration of the sodium aluminate solution is 200 g / l based on aluminum oxide.

[0197] The organic film layer is prepared by reacting the silicon oxide film layer with an organic treatment agent, wherein the organic treatment agent is octyltriethoxysilane.

[0198] The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps:

[0199] S1: 1000 g of type B unsurface-treated chloride rutile titanium dioxide semi-finished product is mixed to obtain a titanium dioxide base material; deionized water is added to the titanium dioxide base material to obtain a desalted water solution of the titanium dioxide base material with a mass concentration of 28%, and the solution is beaten for 30 minutes to obtain a titanium dioxide slurry.

[0200] S2: adding a sodium hydroxide aqueous solution with a mass concentration of 20% to adjust the pH value of the titanium dioxide slurry to 9.8, then adding a dispersant, stirring and mixing for 30 minutes to obtain a dispersed titanium dioxide slurry.

[0201] In the comparative example of the present application, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.40 based on the weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 180 g / l based on silicon dioxide.

[0202] S3: Grind the dispersed titanium dioxide slurry to a particle size of 0.15-0.25 μm, and then add deionized water to obtain a titanium dioxide slurry aqueous solution with a mass concentration of 0.26%.

[0203] S4: Add the silicate solution into the aqueous solution of titanium dioxide slurry at 55°C, stir and mix for 40 minutes to obtain a silicate titanium dioxide mixed slurry; add the aluminum sulfate aqueous solution to the silicate titanium dioxide mixed slurry at a uniform speed in a countercurrent manner within 100 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.0, and mature for 40 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0204] In the embodiment of the present application, the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 1.0% by weight of silicon dioxide to the weight of titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 200 g / l in terms of silicon dioxide, and the concentration of the aluminum sulfate aqueous solution is 100 g / l in terms of aluminum oxide.

[0205] S5: Add the aluminate solution to the titanium dioxide coated with a silicon oxide coating layer within 30 minutes, and at the same time, add a sulfuric acid aqueous solution with a mass concentration of 15% in a downstream manner to obtain an aluminate titanium dioxide mixed slurry with a pH value of 6.8, mature for 30 minutes, continue to adjust the pH value of the aluminate titanium dioxide mixed slurry to 7.0, and continue to mature for 120 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0206] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of the sodium aluminate solution added is 0.5% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 200 g / l based on alumina.

[0207] S6: After washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, the titanium dioxide is pulverized by steam flow and sprayed with an organic treatment agent to obtain a high-performance titanium dioxide pigment coated with an organic coating layer having a carbon content of 0.25%.

[0208] In the embodiment of the present application, the organic treatment agent is a silane coupling agent, specifically octyltriethoxysilane.

[0209] The titanium dioxide pigment obtained in Comparative Examples 1-2 of the present application was used as the sample to be tested, and the color space, temperature resistance and yellowing resistance and weather resistance of the sample to be tested were tested, and the color space, whiteness, yellowing and filtration pressure value of the plastic products made of the sample to be tested were tested. The test results are shown in the following table:

[0210]

[0211] By comparing the test results of Examples 1-3 with those of Comparative Examples 1-2, it can be seen that the high-performance titanium dioxide pigments obtained in Examples 1-3 of the present application used in the Examples have the characteristics of good hue, high tinting strength, strong heat resistance, anti-yellowing and strong weather resistance. At the same time, the high-performance titanium dioxide pigments obtained in Examples 1-3 have good dispersibility in plastics, and the plastic products made therefrom have high whiteness and low yellowness.

[0212] Comparative Example 3

[0213] A titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, the preparation steps S3 and S4 are:

[0214] S3: grinding the dispersed titanium dioxide slurry, and performing cyclone classification to obtain a titanium dioxide particle size D85 in the range of 0.15-0.25 μm; then adding desalted water to obtain a titanium dioxide slurry desalted water solution with a mass concentration of 0.26%.

[0215] S4: Add the silicate solution into the desalted water solution of titanium dioxide slurry at 78°C, stir and mix for 40 minutes to obtain a silicate titanium dioxide mixed slurry; add an inorganic acid aqueous solution with a mass concentration of 10% to the silicate titanium dioxide mixed slurry in a countercurrent manner at a uniform speed within 130 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.2 from slow to fast, and mature for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0216] Comparative Example 4

[0217] A titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, the preparation step S3 is:

[0218] The dispersed titanium dioxide slurry is ground to a particle size of 0.15-0.25 μm; desalted water is then added to obtain a titanium dioxide slurry desalted water solution with a mass concentration of 0.26%, and then the pH value is adjusted to 11, and stirred and mixed for 30 minutes to obtain an alkaline titanium dioxide slurry desalted water solution.

[0219] The titanium dioxide pigments obtained in Comparative Examples 3 and 4 of the present application were used as the samples to be tested, and the color space and weather resistance tests were performed on the samples to be tested. The color space, whiteness and yellowing tests were performed on the plastic products made of the samples to be tested. The test results are shown in the following table:

[0220]

[0221] By comparing the test results of Example 2 with the test results of Comparative Examples 3 and 4, it can be seen that, relative to the titanium dioxide pigment obtained in Comparative Example 3, the high-performance titanium dioxide pigment obtained in Example 2 has a relatively increased L value of 0.12% and a relatively decreased b value of 8.2%; relative to the plastic product in Comparative Example 3, the plastic product in Example 2 has a relatively increased L value of 0.38%, a relatively decreased b value of 5.95%, a relatively increased whiteness of 0.40%, and a relatively decreased yellowing index of 14.46%.

[0222] Compared with the titanium dioxide pigment obtained in comparative example 4, the high-performance titanium dioxide pigment obtained in example 2 has an L value increased by 0.1% and a b value decreased by 6.56%; compared with the plastic product in comparative example 4, the plastic product in example 2 has an L value increased by 0.31%, a b value decreased by 3.57%, a whiteness increased by 0.33%, and a yellowing index decreased by 10.48%.

[0223] This shows that in the preparation method of high-performance titanium dioxide of the present application, in step S3, the dispersed titanium dioxide slurry is ground, cyclone-classified, and then the pH value is adjusted, and the obtained high-performance titanium dioxide slurry has a blue phase and good optical properties.

[0224] Comparative Example 5

[0225] A titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, the preparation step S5 is:

[0226] The aluminate solution is added to the titanium dioxide coated with a silicon oxide coating layer within 30 minutes. At the same time, the aluminum sulfate solution is added in a downstream manner to obtain an aluminate titanium dioxide mixed slurry with a pH value of 6.8. The mixed slurry is matured for 30 minutes, and the pH value of the aluminate titanium dioxide mixed slurry is continuously adjusted to 7.0. The slurry is further matured for 100 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0227] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.3% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 200 g / l based on alumina; the concentration of the aluminum sulfate solution is 105 g / l based on alumina.

[0228] Comparative Example 6

[0229] A titanium dioxide pigment, which is different from Example 2 in that, in the preparation method of the high-performance titanium dioxide pigment, the preparation step S5 is:

[0230] The aluminate solution is added to the titanium dioxide coated with a silicon oxide coating layer within 30 minutes. At the same time, a sulfuric acid aqueous solution with a mass concentration of 15% is added in a downstream manner to obtain an aluminate titanium dioxide mixed slurry with a pH value of 6.8. The mixed slurry is matured for 30 minutes, and the pH value of the aluminate titanium dioxide mixed slurry is continuously adjusted to 7.0. The slurry is further matured for 120 minutes to obtain titanium dioxide coated with an aluminum oxide coating layer.

[0231] In the embodiment of the present application, the aluminate solution is a sodium aluminate solution, and the amount of the sodium aluminate solution added is 0.5% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 200 g / l based on alumina.

[0232] The titanium dioxide pigments obtained in Comparative Examples 5 and 6 of the present application were used as the test samples, and the weather resistance test was performed on the test samples. The test results are shown in the following table:

[0233]

[0234] Comparative analysis of the test results of Example 2 and Comparative Examples 5 and 6 shows that the titanium dioxide pigments obtained in Comparative Examples 5 and 6, after being tested by the acid dissolution method, have a relative increase of 84.38-93.75% in spectrophotometry. This indicates that in the preparation method of high-performance titanium dioxide pigments, in step S5, an aluminate solution is first added to titanium dioxide coated with a silicon oxide coating layer to obtain an aluminate titanium dioxide mixed slurry, and then an inorganic acid aqueous solution is added in a downstream manner from slow to fast to adjust the pH value to within the range of 6.8-7.2, which can form a dense and loose aluminum oxide film layer on the surface of the aluminum oxide coating layer, which is beneficial to improving the weather resistance of the obtained high-performance titanium dioxide.

[0235] Comparative Example 7

[0236] A titanium dioxide pigment, which is different from Example 2 in that the outer side of the titanium dioxide base material is coated with an aluminum oxide coating layer, the outer side of the aluminum oxide coating layer is coated with a silicon oxide film layer, and the outer side of the silicon oxide film layer is coated with an organic film layer.

[0237] The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps:

[0238] S1: 500 g of type A chloride process rutile titanium dioxide semi-finished product without surface treatment and 500 g of type B chloride process rutile titanium dioxide semi-finished product without surface treatment are mixed to obtain a titanium dioxide base material; desalted water is added to the titanium dioxide base material to obtain a titanium dioxide base material desalted water solution with a mass concentration of 32%, and the mixture is beaten for 20 minutes to obtain a titanium dioxide slurry.

[0239] S2: adding a sodium hydroxide aqueous solution with a mass concentration of 20% to adjust the pH value of the titanium dioxide slurry to 10.2, then adding a dispersant, stirring and mixing for 30 minutes to obtain a dispersed titanium dioxide slurry.

[0240] In the comparative example of the present application, the dispersant is a sodium silicate aqueous solution, and the amount of the sodium silicate aqueous solution added is 0.35% by weight of silicon dioxide to the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 190 g / l in terms of silicon dioxide.

[0241] S3: Grind the dispersed titanium dioxide slurry, and after cyclone classification, obtain a titanium dioxide particle size D85 in the range of 0.15-0.25 μm; then add desalted water to obtain a titanium dioxide slurry desalted water solution with a mass concentration of 0.26%, and then adjust the pH value to 11, stir and mix for 30 minutes, and obtain an alkaline titanium dioxide slurry desalted water solution.

[0242] S4: Add the aluminate solution to the alkaline titanium dioxide slurry desalted water solution within 70 minutes to obtain an aluminate titanium dioxide mixed slurry; add the aluminum sulfate solution to the aluminate titanium dioxide mixed slurry in a downstream manner from slow to fast, adjust the pH value of the aluminate solution mixed titanium dioxide slurry within the range of 6.8-7.2, mature for 30 minutes, continue to adjust the pH value of the aluminate solution mixed titanium dioxide slurry to 7.0, and continue to mature for 100 minutes to obtain titanium dioxide coated with an alumina coating layer.

[0243] In the comparative example of the present application, the aluminate solution is a sodium aluminate solution, and the amount of sodium aluminate solution added is 0.7% by weight of the titanium dioxide base material based on alumina, wherein the concentration of the sodium aluminate solution is 200 g / l based on alumina; the concentration of the aluminum sulfate solution is 105 g / l based on alumina.

[0244] S5: Add the silicate solution to the titanium dioxide with an alumina coating layer at 78°C, stir and mix for 40 minutes to obtain a silicate titanium dioxide mixed slurry; add an inorganic acid aqueous solution with a mass concentration of 10% to the silicate titanium dioxide mixed slurry in a countercurrent manner at a uniform speed within 130 minutes, and slowly adjust the pH value of the silicate titanium dioxide mixed slurry to 7.2 from slow to fast, and mature it for 50 minutes to obtain titanium dioxide coated with a silicon oxide coating layer.

[0245] In the comparative example of the present application, the silicate solution is a sodium silicate aqueous solution, and the amount of sodium silicate aqueous solution added is 0.9% by weight of silicon dioxide to the weight of the titanium dioxide base material, wherein the concentration of the sodium silicate aqueous solution is 200 g / l based on silicon dioxide; the inorganic acid aqueous solution is a hydrochloric acid aqueous solution.

[0246] S6: After washing, filtering, dehydrating and drying the titanium dioxide coated with the silicon oxide coating layer, the titanium dioxide is pulverized by steam flow and sprayed with an organic treatment agent to obtain a high-performance titanium dioxide pigment coated with an organic coating layer having a carbon content of 0.35%.

[0247] In the comparative example of the present application, the organic treatment agent is a silane coupling agent, specifically octyltriethoxysilane.

[0248] Comparative Example 8

[0249] A titanium dioxide pigment, which is different from Example 2 in that the organic treatment agent is tributyl citrate.

[0250] The titanium dioxide pigments obtained in Comparative Examples 7 and 8 of the present application were used as test samples, and the heat resistance, yellowing resistance and weather resistance of the test samples were tested. The filtration pressure value of the plastic products made of the test samples was tested. The test results are shown in the following table:

[0251]

[0252] Comparative analysis of the test results of Example 2 and Comparative Example 7 shows that the spectrophotometric value of the titanium dioxide pigment obtained in Comparative Example 7 is increased by 108.59% relative to the high-performance titanium dioxide pigment obtained in Example 2. This shows that the titanium dioxide base material is sequentially coated with a silicon oxide coating layer, an aluminum oxide film layer and an organic film layer from the inside to the outside, which can improve the weather resistance of the obtained high-performance titanium dioxide pigment.

[0253] Comparative analysis of the test results of Example 2 and Comparative Example 8 shows that the ΔE value of the titanium dioxide pigment obtained in Comparative Example 8 is relatively increased by 50.00%, and the filtration pressure value is relatively increased by 58.10% relative to the high-performance titanium dioxide pigment obtained in Example 2. This shows that in the total raw materials for preparing the high-performance titanium dioxide pigment of the present application, the organic treatment agent is one or more of trimethylolpropane, trimethylolethane, silicone oil and silane coupling agent, which can improve the heat resistance and yellowing resistance of the obtained high-performance titanium dioxide pigment and its dispersibility when preparing plastic products.

[0254] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high performance titanium dioxide pigment, characterized in that: It comprises a titanium dioxide base material, the titanium dioxide base material is coated with a silicon oxide coating layer on the outside, the silicon oxide coating layer is coated with an aluminum oxide film layer on the outside, and the aluminum oxide film layer is coated with an organic film layer on the outside; The titanium dioxide base material is composed of a mixture of two chloride-process rutile titanium dioxide semi-finished products that have not been surface treated; The silicon oxide coating layer is prepared by reacting a titanium dioxide base material with a silicate solution; The aluminum oxide film layer is prepared by reacting the silicon oxide coating layer with an aluminate solution; The organic film layer is prepared by reacting a silicon oxide film layer with an organic treatment agent; The organic treatment agent is polyol and / or organosilicon; The preparation method of the high-performance titanium dioxide pigment comprises the following preparation steps: S1: mixing two unsurface-treated chloride-process rutile titanium dioxide semi-finished products to obtain a titanium dioxide base material; adding desalted water to the titanium dioxide base material, beating the mixture to obtain a titanium dioxide slurry; S2: adjusting the pH value of the titanium dioxide slurry to 9.2-10.5, then adding a dispersant, stirring and mixing, to obtain a dispersed titanium dioxide slurry; S3: grinding the dispersed titanium dioxide slurry, cyclone classification, adding desalted water, adjusting the pH value to 10.0-11.0, stirring and mixing, and obtaining a titanium dioxide slurry desalted water solution; S4: adding the silicate solution to the desalted water solution of the titanium dioxide slurry, stirring and mixing to obtain a silicate titanium dioxide mixed slurry, adjusting the pH value of the silicate titanium dioxide mixed slurry to 7.0-7.2, and aging to obtain titanium dioxide coated with a silicon oxide coating layer; S5: adding the aluminate solution to the titanium dioxide coated with the silicon oxide coating layer, stirring and mixing to obtain aluminate titanium dioxide mixed slurry, and then adding an inorganic acid aqueous solution in a downstream manner from slow to fast to adjust the pH value of the aluminate titanium dioxide mixed slurry to a range of 6.8-7.2, and aging to obtain titanium dioxide coated with the aluminum oxide coating layer; S6: washing, filtering, dehydrating and drying the titanium dioxide coated with the aluminum oxide coating layer, and then steam-crushing the titanium dioxide and spraying an organic treatment agent to obtain a high-performance titanium dioxide pigment coated with an organic coating layer; The organic treatment agent is polyol and / or organosilicon.

2. The high performance titanium dioxide pigment according to claim 1, characterized in that In S1, the weight ratio of the two unsurface-treated chloride-process rutile titanium dioxide semi-finished products is 5:5 or 4:6 or 6:

4.

3. The high performance titanium dioxide pigment according to claim 1, characterized in that: In the S2, the dispersant is one or both of phosphate and silicate.

4. The high performance titanium dioxide pigment according to claim 1, characterized in that: In S3, the dispersed titanium dioxide slurry is ground and subjected to cyclone classification to obtain a titanium dioxide particle size D90 of 0.15-0.25 μm.

5. The high performance titanium dioxide pigment according to claim 1, characterized in that: In S4, the amount of the silicate solution added is 0.6-1.0% by weight of the titanium dioxide base material based on the effective ingredients of the silicate solution.

6. The method for preparing a high-performance titanium dioxide pigment according to claim 5, characterized in that: In the S4, a silicate solution is added to a desalted water solution of titanium dioxide slurry at a temperature of 75-85° C., and after stirring and mixing, a silicate titanium dioxide mixed slurry is obtained, and an inorganic acid aqueous solution with a mass fraction of 8-15% is uniformly added to the silicate titanium dioxide mixed slurry within 90-150 minutes, and the pH value of the silicate titanium dioxide mixed slurry is adjusted to 7.0-7.2, and the mixture is aged to obtain titanium dioxide coated with a silicon oxide coating layer.

7. The high performance titanium dioxide pigment according to claim 1, characterized in that: Preferably, in S5, the amount of the aluminate solution added is 0.7-1.2% by weight of the titanium dioxide base material based on the effective ingredients of the aluminate solution.

8. The method for preparing a high-performance titanium dioxide pigment according to claim 6, characterized in that: In S5, an aluminate solution is added to titanium dioxide coated with a silicon oxide coating layer within 50-90 minutes, and after stirring and mixing, an aluminate titanium dioxide mixed slurry is obtained, and a sulfate solution is added to the aluminate titanium dioxide mixed slurry, and the pH value of the aluminate solution mixed titanium dioxide slurry is adjusted to be in the range of 6.8-7.2, and ripened to obtain titanium dioxide coated with an aluminum oxide coating layer.

9. The high performance titanium dioxide pigment according to claim 1, characterized in that: In the step S6, the organic treatment agent is one or more of trimethylolpropane, trimethylolethane, silicone oil and a silane coupling agent.

Images