Titanium dioxide and preparation method and application thereof

Abstract

The invention relates to the technical field of titanium dioxide production, in particular to titanium dioxide as well as a preparation method and application thereof. Comprising a titanium dioxide core, and an inorganic coating layer and an organic coating layer which sequentially coat at least part of the surface of the titanium dioxide core, the organic coating layer comprises one or a combination of more of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester. According to the invention, by reasonably selecting the variety of the coating agent of the organic coating layer and carrying out coating modification on the titanium dioxide core, the dispersibility and fluidity of titanium dioxide can be improved on the basis of ensuring better hue, covering power and glossiness, and the VOC content of titanium dioxide is obviously reduced, so that the titanium dioxide is green and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of titanium dioxide production, and in particular to titanium dioxide and a preparation method and application thereof. Background Art

[0002] Titanium dioxide is a white inorganic pigment with excellent performance. It is widely used in coatings, plastics, papermaking, printing inks, chemical fibers, rubber, cosmetics and other fields due to its non-toxicity, excellent opacity, whiteness and brightness. It is known as the "king of white pigments".

[0003] VOC is the abbreviation of Volatile Organic Compound. The World Health Organization (WHO, 1989) defines total volatile organic compounds (TVOC) as a general term for volatile organic compounds with a melting point below room temperature and a boiling point between 50-260°C. High VOC emissions in the environment will have a great impact on human health, and may induce diseases including allergies, asthma, headaches and excessive excitement. People who live and work in such an environment for a long time will face great health risks.

[0004] Titanium dioxide is an inorganic material, and its VOC mainly comes from organic coating agents. At present, when preparing titanium dioxide, in order to improve the application performance of the product, titanium dioxide is usually organically coated. Polyols (such as trimethylolpropane, trimethylolethane, etc.) are commonly used as organic coating agents for titanium dioxide in coatings. Trimethylolpropane is classified as Rep.Tox.Cat 2 and is further prepared to be classified as Repr.1B. The green eco-label of downstream customers' products may be greatly affected. Titanium dioxide prepared with it as an organic coating agent will produce VOCs, which seriously affect human health. Therefore, it is of great significance to provide a green, environmentally friendly, VOC-free titanium dioxide and a preparation method thereof.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The first purpose of the present invention is to provide a titanium dioxide, aiming to solve the technical problem that the organic coating agent of titanium dioxide used in the prior art has poor environmental protection and the titanium dioxide modified by the coating will produce VOC, which is harmful to the environment and human health; the present invention can improve the dispersibility and fluidity of titanium dioxide while ensuring good hue, hiding power and glossiness, and significantly reduce its VOC content, which is green and environmentally friendly by reasonably selecting the type of coating agent for the organic coating layer.

[0007] The second object of the present invention is to provide a method for preparing the titanium dioxide as described above. The preparation conditions of the method of the present invention are mild and controllable, the operation is simple, and it is convenient for mass production.

[0008] The third object of the present invention is to provide a use of the titanium dioxide as described above or the titanium dioxide prepared by the method for preparing the titanium dioxide as described above in preparing coatings.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] A titanium dioxide powder comprises a titanium dioxide core, and an inorganic coating layer and an organic coating layer sequentially coated on at least a portion of the surface of the titanium dioxide core; the organic coating layer comprises one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester.

[0011] Furthermore, the inorganic coating layer includes one or more combinations of zirconium oxide, aluminum oxide, silicon oxide, cerium oxide, titanium oxide, zinc oxide, boron oxide, calcium phosphate, phosphorus pentoxide, magnesium phosphate and aluminum phosphate.

[0012] A method for preparing titanium dioxide as described in any one of the aforementioned embodiments, comprising the following steps:

[0013] Titanium dioxide is subjected to an inorganic coating treatment to form an inorganic coating layer on the outer surface of the titanium dioxide, and then subjected to an organic coating treatment to form an organic coating layer on the outer side of the inorganic coating layer, thereby obtaining the titanium dioxide; in the organic coating treatment process, the organic coating agent used includes one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester.

[0014] Furthermore, the preparation method of titanium dioxide specifically comprises the following steps:

[0015] S1. Adding an inorganic coating agent to the sand-milled titanium dioxide slurry for inorganic coating treatment, and obtaining a titanium dioxide filter cake by filter pressing and washing;

[0016] S2. flash drying and air flow pulverizing the titanium dioxide filter cake, and adding the organic coating agent during the flash drying and / or air flow pulverizing to perform organic coating treatment to obtain.

[0017] Furthermore, the titanium dioxide slurry is a sulfuric acid process titanium dioxide slurry and / or a chloride process titanium dioxide slurry.

[0018] Furthermore, TiO 2 The mass concentration of the titanium dioxide slurry is 300-450g / L.

[0019] Furthermore, the temperature of the inorganic coating treatment process is 60-95°C.

[0020] Furthermore, the pH of the slurry during the inorganic coating treatment is 6-9.

[0021] Furthermore, the amount of the organic coating agent added is 2 0.3wt%-1.5wt%.

[0022] Use of the titanium dioxide described in any one of the aforementioned embodiments or the titanium dioxide prepared by the method for preparing titanium dioxide described in any one of the aforementioned embodiments in preparing a coating.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention selects one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester as organic coating agents to carry out coating modification on titanium dioxide. The hydroxyl groups in the organic coating agent can undergo dehydration condensation reaction with the hydroxyl groups on the surface of titanium dioxide. The organic coating agents are all combined on the surface of titanium dioxide in a chemically bonded manner, so that the organic coating agents are firmly adsorbed on the surface of titanium dioxide, and no organic matter is released to generate VOC. The invention has the advantages of being green and environmentally friendly, and does not contain VOC, which is beneficial to human health and environmental protection. In addition, the steric hindrance effect of the selected organic coating agent can effectively reduce the agglomeration between particles, so that the prepared titanium dioxide also has excellent dispersibility, dispersion stability and thermal storage stability.

[0025] The method of the invention has simple process, and the prepared titanium dioxide has better dispersibility, fluidity and environmental protection while ensuring good hue, hiding power and glossiness. DETAILED DESCRIPTION

[0026] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0027] The first aspect of the present invention provides a titanium dioxide powder, comprising a titanium dioxide core, and an inorganic coating layer and an organic coating layer sequentially coated on at least a portion of the surface of the titanium dioxide core; the organic coating agent used to form the organic coating layer comprises one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester.

[0028] The present invention selects one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester as organic coating agents to carry out coating modification on titanium dioxide. Through the dehydration condensation reaction between the organic coating agents and the hydroxyl groups on the surface of titanium dioxide, a firmly bonded organic coating layer can be formed on the surface of titanium dioxide without releasing organic matter to generate VOC. In addition, the steric hindrance effect of the selected organic coating agent can effectively reduce the agglomeration between particles, so that the titanium dioxide provided by the present invention also has excellent dispersibility, dispersion stability and thermal storage stability.

[0029] The type of organic coating agent will affect the dispersibility and VOC content of titanium dioxide products. The present invention significantly improves the dispersibility and fluidity of titanium dioxide while ensuring good hue, hiding power and gloss by reasonably selecting the type of coating agent for the organic coating layer. In addition, the titanium dioxide provided does not contain VOC and is green and environmentally friendly.

[0030] In some specific embodiments of the present invention, the inorganic coating layer includes one or more combinations of zirconium oxide, aluminum oxide, silicon oxide, cerium oxide, titanium oxide, zinc oxide, boron oxide, calcium phosphate, phosphorus pentoxide, magnesium phosphate and aluminum phosphate.

[0031] In some specific embodiments of the present invention, the titanium dioxide is coated with at least two different inorganic coating layers. The above inorganic coating is beneficial to improve the glossiness, hiding power, weather resistance and dispersibility of titanium dioxide.

[0032] A second aspect of the present invention provides a method for preparing titanium dioxide as described in any one of the aforementioned embodiments, comprising the following steps:

[0033] Titanium dioxide is subjected to an inorganic coating treatment to form an inorganic coating layer on the outer surface of the titanium dioxide, and then subjected to an organic coating treatment to form an organic coating layer on the outer side of the inorganic coating layer, thereby obtaining the titanium dioxide; in the organic coating treatment process, the organic coating agent used includes one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester.

[0034] The method of the present invention has simple process, mild and controllable preparation conditions, and is convenient for mass production; inorganic coating is performed first and then organic coating, which is conducive to uniform coating, thereby improving the dispersibility of the product; the hydroxyl groups in the organic coating agent used can undergo dehydration condensation reaction with the hydroxyl groups on the surface of titanium dioxide, so that the hydroxyl groups are firmly adsorbed on the surface of titanium dioxide, and no organic matter is released to generate VOC, which has the advantage of being green and environmentally friendly.

[0035] In some specific embodiments of the present invention, the method for preparing titanium dioxide specifically comprises the following steps:

[0036] S1. Adding an inorganic coating agent to the qualified titanium dioxide slurry after sand milling, performing inorganic coating treatment to obtain a composite material having an inorganic coating layer, and obtaining a titanium dioxide filter cake by filter pressing and washing;

[0037] S2. Flash drying and air flow pulverizing are performed on the titanium dioxide filter cake, and an organic coating agent is added during the flash drying and / or air flow pulverizing to perform an organic coating treatment to obtain a final titanium dioxide product.

[0038] In some specific embodiments of the present invention, the polyglycerol used may be polyglycerol-6; and the polyglycerol ester used may be polyglycerol-6 caprylate.

[0039] In some preferred embodiments of the present invention, polyglycerol-6 and polyglycerol-6 caprylate are used in combination for better effect. When used in combination, the mass ratio of polyglycerol-6 and polyglycerol-6 caprylate is 2-3:1. For example, it can be any point value among 2:1, 2.2:1, 2.5:1, 2.8:1, 3:1, or a range value consisting of any two point values.

[0040] In some specific embodiments of the present invention, the inorganic coating agent can be one or more combinations of sodium aluminate, zirconium oxychloride, and sodium silicate.

[0041] In some specific embodiments of the present invention, the titanium dioxide slurry used is sulfuric acid process titanium dioxide slurry and / or chloride process titanium dioxide slurry.

[0042] In some specific embodiments of the present invention, the titanium dioxide slurry is prepared by diluting a qualified titanium dioxide base material.

[0043] In some specific embodiments of the present invention, TiO 2 The mass concentration of the titanium dioxide slurry used is 300-450g / L, for example, it can be any point value among 300g / L, 330g / L, 350g / L, 370g / L, 400g / L, 420g / L, 450g / L, or a range value consisting of any two point values.

[0044] In some specific embodiments of the present invention, the temperature of the inorganic coating treatment process is 60-95°C, for example, it can be any point value among 60°C, 63°C, 65°C, 67°C, 70°C, 72°C, 75°C, 77°C, 80°C, 82°C, 85°C, 87°C, 90°C, 92°C, 95°C, or a range value consisting of any two point values.

[0045] In some specific embodiments of the present invention, the pH of the slurry during the inorganic coating treatment is 6-9. For example, the pH of the slurry can be any point value among 6, 6.3, 6.5, 6.7, 7, 7.3, 7.5, 7.8, 8, 8.3, 8.5, 8.7, 9, or a range value consisting of any two point values.

[0046] In some specific embodiments of the present invention, during the organic coating treatment, the amount of organic coating agent added is: 2 0.3wt%-1.5wt%, for example, it can be any point value among 0.3wt%, 0.5wt%, 0.7wt%, 0.8wt%, 1wt%, 1.2wt%, 1.3wt%, 1.5wt% or a range value composed of any two point values.

[0047] A third aspect of the present invention provides a use of the titanium dioxide as described in any one of the aforementioned embodiments or the titanium dioxide prepared by the method for preparing the titanium dioxide as described in any one of the aforementioned embodiments in preparing a coating.

[0048] The water-based latex paint prepared by using the titanium dioxide provided by the invention has excellent hue, hiding power, glossiness and dispersibility, can reduce its VOC content, and has better environmental protection.

[0049] The following is a detailed description of some embodiments of the present invention in conjunction with specific application examples. The raw materials used in the examples can be purchased from the market unless otherwise specified.

[0050] Example 1

[0051] S1. Take the sand-milled titanium dioxide slurry with a mass concentration of 300 g / L, and add 0.45% zirconium oxychloride and 3.0% sodium aluminate (TiO 2 The temperature of the mixed slurry in the inorganic coating process is controlled to be 60° C. and the pH value is 7.0 to 7.5, and an inorganic coating treatment is performed to obtain a composite material having a zirconium coating layer and an aluminum coating layer, and then pressure filtration and water washing are performed in sequence to obtain a titanium dioxide filter cake;

[0052] S2. Flash drying and air flow pulverization of the titanium dioxide filter cake, and adding polyglycerol-6 (molecular formula: C 18 H 38 O 13 , the addition amount is TiO 2 0.5wt%) is subjected to organic coating treatment to obtain the final titanium dioxide product.

[0053] The titanium dioxide prepared in this embodiment includes a titanium dioxide core, and a zirconium oxide inorganic coating layer, an aluminum oxide inorganic coating layer and a polyglycerol-6 organic coating layer sequentially coated on the surface of the titanium dioxide core from the inside to the outside.

[0054] Example 2

[0055] S1. Take the sand-milled titanium dioxide slurry with a mass concentration of 350g / L, and add 0.55% zirconium oxychloride and 2.8% sodium aluminate (TiO 2 The temperature of the mixed slurry in the inorganic coating process is controlled to be 70° C. and the pH value is 7.5 to 8.0, and an inorganic coating treatment is performed to obtain a composite material having a zirconium coating layer and an aluminum coating layer, and then filter pressing and washing are performed in sequence to obtain a titanium dioxide filter cake;

[0056] S2. Flash drying and air flow pulverization of the titanium dioxide filter cake, and adding polyglycerol-6 caprylate (molecular formula: C 26 H5 2 O 14 , the addition amount is TiO 2 0.8wt%) is subjected to organic coating treatment to obtain the final titanium dioxide product.

[0057] The titanium dioxide prepared in this embodiment includes a titanium dioxide core, and a zirconium oxide inorganic coating layer, an aluminum oxide inorganic coating layer and a polyglycerol-6 caprylate organic coating layer sequentially coated on the surface of the titanium dioxide core from the inside to the outside.

[0058] Example 3

[0059] S1. Take the sand-milled titanium dioxide slurry with a mass concentration of 400g / L, and add 2.5% sodium silicate and 3.0% sodium aluminate (TiO 2 The temperature of the mixed slurry in the inorganic coating process is controlled to be 85° C. and the pH value is 7.0-8.0, and an inorganic coating treatment is performed to obtain a composite material having a silicon coating layer and an aluminum coating layer, and then filter pressing and washing are performed in sequence to obtain a titanium dioxide filter cake;

[0060] S2. Flash drying and air flow pulverization of the titanium dioxide filter cake, and adding polypropylene glycol (molecular formula: H(C 3 H 6 O) n OH, molecular weight 400, added in an amount equal to the amount of TiO 2 1.2wt%) was organically coated to obtain the final titanium dioxide product.

[0061] The titanium dioxide prepared in this embodiment includes a titanium dioxide core, and a silicon oxide inorganic coating layer, an aluminum oxide inorganic coating layer and a polypropylene glycol organic coating layer sequentially coated on the surface of the titanium dioxide core from the inside to the outside.

[0062] Example 4

[0063] S1. Take the sand-milled titanium dioxide slurry with a mass concentration of 450g / L, and add 2.5% sodium silicate and 2.8% sodium aluminate (TiO 2 The temperature of the mixed slurry in the inorganic coating process is controlled to be 95°C and the pH value is 6.0-7.0, and an inorganic coating treatment is performed to obtain a composite material having a silicon coating layer and an aluminum coating layer, and then pressure filtration and water washing are performed in sequence to obtain a titanium dioxide filter cake;

[0064] S2. Flash dry and air flow pulverize the titanium dioxide filter cake, and add PEG-26 glycerol ether (molecular formula: HO(CH 2 CH 2 O) n CH[CH 2 (OCH 2 CH2) n OH] 2 , molecular weight 610.71, added amount is TiO 2 1.0wt%) is subjected to organic coating treatment to obtain the final titanium dioxide product.

[0065] The titanium dioxide prepared in this embodiment includes a titanium dioxide core, and a silicon oxide inorganic coating layer, an aluminum oxide inorganic coating layer and a PEG-26 glycerol ether organic coating layer sequentially coated on the surface of the titanium dioxide core from the inside to the outside.

[0066] Example 5

[0067] S1. Take the sand-milled titanium dioxide slurry with a mass concentration of 450g / L, and add 2.8% sodium silicate and 2.8% sodium aluminate (TiO 2 The temperature of the mixed slurry in the inorganic coating process is controlled to be 95°C and the pH value is 6.0-7.0, and an inorganic coating treatment is performed to obtain a composite material having a silicon coating layer and an aluminum coating layer, and then pressure filtration and water washing are performed in sequence to obtain a titanium dioxide filter cake;

[0068] S2. Flash dry and air flow crush the titanium dioxide filter cake, and add polyglycerol-6 caprylate (the amount added is the amount of TiO2 in the slurry) to the feed port of the flash dryer. 2 0.2wt%), polyglycerol-6 (the amount added is the amount of TiO in the slurry) was added during the air flow milling. 2 0.5wt%) is subjected to organic coating treatment to obtain the final titanium dioxide product.

[0069] The titanium dioxide prepared in this embodiment includes a titanium dioxide core, and a silicon oxide inorganic coating layer, an aluminum oxide inorganic coating layer, and an organic coating layer of polyglycerol-6 caprylate and polyglycerol-6, which are sequentially coated on the surface of the titanium dioxide core from the inside to the outside. Adding them during flash evaporation can increase the fluidity of the material, make the production feeding more stable, and make the later coating more uniform.

[0070] Example 6

[0071] Example 6 is similar to Example 1, except that in step S2, a mixture of polyglycerol-6 and polyglycerol-6 caprylate in a mass ratio of 2.2:1 is used as the organic coating agent, the total amount of the organic coating agent remains unchanged, and the other conditions are the same as those in Example 1.

[0072] Comparative Example 1

[0073] Comparative Example 1 is similar to Example 1, except that in step S2, polyglycerol-6 is replaced by an equal amount of trimethylolpropane, and the other conditions are the same as those in Example 1.

[0074] Test example

[0075] (1) The VOC content in the titanium dioxide prepared in each embodiment and comparative example was tested respectively, and the test method was as follows:

[0076] Weigh 1g of titanium dioxide, add 10ml of methanol, vortex shake for 2min, then ultrasonic for 30min, and vortex shake for 2min again. Then centrifuge at 4000rpm for 20min to obtain a sample, which is tested by gas chromatography. The sample is filtered through a 0.45μm membrane and then injected. Whether it is VOC is determined based on the peak time, and the VOC content is calculated based on the peak area. The test results are shown in Table 1.

[0077] (2) The titanium dioxide prepared in each embodiment and comparative example was prepared into a water-based latex paint, wherein the water-based latex paint formula included 15 parts of titanium dioxide and 56 parts of acrylic emulsion by weight; the hue, hiding power, glossiness and dispersibility of each water-based latex paint were tested respectively. The dispersibility was tested using a scraper fineness meter. The smaller the paint fineness, the better the dispersibility. The test results are shown in Table 1.

[0078] (3) The fluidity of the titanium dioxide prepared in each embodiment and each comparative example was characterized by testing its Hausner ratio. The smaller the Hausner ratio, the better the fluidity. The test results are shown in Table 2.

[0079] Table 1

[0080] sample <![CDATA[L * ]]> <![CDATA[b * ]]> Covering power 20° glossiness Water dispersibility / μm VOC / ppm Example 1 95.35 1.21 92.58 51.8 25 0 Example 2 95.41 1.23 92.53 52.9 25 0 Example 3 95.38 1.22 92.45 51.8 25 0 Example 4 95.47 1.23 92.84 53.1 20 0 Example 5 95.53 1.19 92.98 55.6 20 0 Example 6 95.65 1.18 93.20 58.7 17.5 0 Comparative Example 1 95.36 1.24 92.43 51.5 35 2180

[0081] It can be seen from the data in Table 1 that the titanium dioxide prepared by the method of the present invention does not contain VOC and is a green and environmentally friendly titanium dioxide. Moreover, by comparing the experimental results of the embodiment and the comparative example, it can be seen that the titanium dioxide prepared by the present invention has better dispersibility, and other properties such as hue, hiding power and glossiness are not reduced compared with the comparative example, and has better comprehensive performance.

[0082] Table 2

[0083] sample <![CDATA[Bulk density g / cm 3 > <![CDATA[Tap density g / cm 3 > Hausner Example 1 0.5434 1.013 1.864 Example 2 0.5413 1.002 1.851 Example 3 0.5560 1.011 1.818 Example 4 0.5633 1.006 1.786 Example 5 0.5642 1.003 1.778 Example 6 0.5675 0.998 1.759 Comparative Example 1 0.5244 1.002 1.911

[0084] It can be seen from the data in Table 2 that the titanium dioxide prepared by the method of the present invention has better fluidity.

[0085] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A titanium dioxide, characterized in that: It comprises a titanium dioxide core, and an inorganic coating layer and an organic coating layer sequentially coated on at least a part of the surface of the titanium dioxide core; the organic coating layer comprises one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester.

2. The titanium dioxide according to claim 1, characterized in that The inorganic coating layer includes one or more combinations of zirconium oxide, aluminum oxide, silicon oxide, cerium oxide, titanium oxide, zinc oxide, boron oxide, calcium phosphate, phosphorus pentoxide, magnesium phosphate and aluminum phosphate.

3. The method for preparing titanium dioxide according to claim 1 or 2, characterized in that: The steps include: Titanium dioxide is subjected to an inorganic coating treatment to form an inorganic coating layer on the outer surface of the titanium dioxide, and then subjected to an organic coating treatment to form an organic coating layer on the outer side of the inorganic coating layer, thereby obtaining the titanium dioxide; in the organic coating treatment process, the organic coating agent used includes one or more combinations of polypropylene glycol, polyglycerol, polyglycerol, polyglycerol ether and polyglycerol ester.

4. The method for preparing titanium dioxide according to claim 3, characterized in that: The specific steps include: S1. Adding an inorganic coating agent to the sand-milled titanium dioxide slurry for inorganic coating treatment, and obtaining a titanium dioxide filter cake by filter pressing and washing; S2. flash drying and air flow pulverizing the titanium dioxide filter cake, and adding the organic coating agent during the flash drying and / or air flow pulverizing to perform organic coating treatment to obtain.

5. The method for preparing titanium dioxide according to claim 4, characterized in that: The titanium dioxide slurry is a sulfuric acid process titanium dioxide slurry and / or a chloride process titanium dioxide slurry.

6. The method for preparing titanium dioxide according to claim 4, characterized in that: Calculated in terms of TiO2, the mass concentration of the titanium dioxide slurry is 300-450 g / L.

7. The method for preparing titanium dioxide according to claim 4, characterized in that: The temperature of the inorganic coating treatment process is 60-95°C.

8. The method for preparing titanium dioxide according to claim 4, characterized in that: The pH of the slurry during the inorganic coating treatment is 6-9.

9. The method for preparing titanium dioxide according to claim 3, characterized in that: The amount of the organic coating agent added is 0.3wt%-1.5wt% of the TiO2 in the titanium dioxide slurry.

10. Use of the titanium dioxide according to claim 1 or 2 or the titanium dioxide prepared by the method for preparing the titanium dioxide according to any one of claims 3 to 9 in preparing coatings.