CN111410853B - Titanium dioxide pigment and preparation method thereof - Google Patents
Titanium dioxide pigment and preparation method thereof Download PDFInfo
- Publication number
- CN111410853B CN111410853B CN201910009825.2A CN201910009825A CN111410853B CN 111410853 B CN111410853 B CN 111410853B CN 201910009825 A CN201910009825 A CN 201910009825A CN 111410853 B CN111410853 B CN 111410853B
- Authority
- CN
- China
- Prior art keywords
- titanium dioxide
- coating layer
- phosphate
- dioxide particles
- aluminum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/36—Compounds of titanium
- C09C1/3607—Titanium dioxide
- C09C1/3653—Treatment with inorganic compounds
- C09C1/3661—Coating
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/675—Oxides, hydroxides or carbonates
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Paper (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Abstract
The present invention aims to suppress the photocatalytic activity of titanium dioxide itself when titanium dioxide is used for paints, plastics, decorative papers, and the like. The invention provides titanium dioxide with a coating layer consisting of 4 components of phosphorus, cerium, aluminum and calcium and a manufacturing method thereof. The titanium dioxide particles having the coating layer of the present invention not only retain their properties as a white pigment but also suppress the photocatalytic activity possessed by titanium dioxide itself. Therefore, the coating can be stably applied to the aspects of coating, plastics, decorative paper and the like.
Description
Technical Field
The invention specifically relates to a titanium dioxide pigment and a manufacturing method thereof, belonging to the technical field of titanium dioxide pigments.
Background
The titanium dioxide pigment is used as a white pigment for paints, plastics, etc. because of its high refractive index, however, when irradiated with ultraviolet rays and in the presence of moisture and oxygen, the resin component having photocatalytic activity is discolored or decomposed. Therefore, a coating layer of a hydrous oxide such as high-density silica or alumina is generally formed on the surface of titanium dioxide particles to suppress the photocatalytic action.
A titanium dioxide pigment can also be used for the decorative paper, but when irradiated with ultraviolet rays, titanium dioxide itself turns blue black. Therefore, a coating layer of a hydrous oxide such as silica or alumina is formed on the surface of the titania particles, and then the titania particles are heated and calcined, which increases the production cost.
Therefore, titanium dioxide is used for decorative paper, and is generally coated with aluminum phosphate to improve light resistance.
For example, patent document US5,785,748 shows that-O-P-O-Al-O-P molecular chains formed by reacting an aluminum compound with a phosphoric acid compound condense with each other to form a network coating on the surface of titanium dioxide, and the coating is adhered to titanium dioxide particles to have water impermeability.
Patent document US4,239,548 discloses a method for improving the photochemical stability of titanium dioxide by forming a cerium phosphate layer inside an aluminum phosphate coating layer.
In the case of a light colored or white paper, the gray phenomenon cannot be sufficiently suppressed even by applying the above-mentioned coating technique of cerium phosphate and aluminum phosphate, and further improvement is desired.
Disclosure of Invention
The present inventors have thought to treat the titanium dioxide-coated component with calcium phosphate such as Hydroxyapatite which constitutes bones and teeth of our human body. However, various attempts have been made to chemically synthesize hydroxyapatite, and many of them are expensive methods such as the sol-gel method.
On the other hand, the reference documents describe that, in order to preserve the trails of limestone buildings made of marble, limestone or the like, an aqueous solution of diammonium hydrogen phosphate (DAP) is applied to the surface of the limestone building as shown in fig. 1, and the surface of the building is reacted according to the following reaction formula to form a similar compound of Hydroxyapatite.
10CaCO3 + 5(NH4)2HPO4 → Ca10(PO4,CO3)6(OH,CO3)2 + 5(NH4)2CO3 + 3CO2 + 2H2O
[ REFERENCE ] materials (Basel) v.11(4); 2018 Apr PMC5951441
The present inventors believe that the reaction shown in the above references is an in-situ reaction at the surface of a building, and that hydroxyapatite and similar compounds are epitaxial growth epitaxially grown and can be tried on titanium dioxide particle coatings.
Surprisingly, it was found that when cerium phosphate, aluminum phosphate, calcium phosphate and aluminum hydroxide are combined as the coating components of the titanium dioxide particles, blackening or graying of the decorative paper can be significantly suppressed.
That is, the present invention is based on titanium dioxide particles as a substrate, and has a coating layer composed of 4 components of phosphorus, cerium, aluminum, and calcium on the surface thereof.
The present invention is based on titanium dioxide particles as a substrate, and has a coating layer on the surface thereof, the coating layer being composed of cerium phosphate, aluminum phosphate, calcium phosphate and aluminum hydroxide.
The titanium dioxide particles as the base material used in the present invention are obtained by a sulfuric acid process or a chlorination process, and are rutile-type crystals.
The particle size is preferably 600 or more oriented particle diameters (interval between two parallel lines sandwiching the particle in a predetermined direction) in the field of electron microscope, and the number average is 0.15 to 0.35. mu.m. The average particle diameters described below were all measured by this method.
In a preferred embodiment of the present invention, titanium dioxide particles are used as a base material, and the titanium dioxide particles have a 1 st coating layer made of cerium phosphate, a 2 nd coating layer made of aluminum phosphate, a 3 rd coating layer made of calcium phosphate, and a 4 th coating layer made of aluminum hydroxide.
In a more preferred embodiment, the titanium dioxide particles are used as a base material, and the titanium dioxide particles have a 1 st coating layer made of cerium phosphate, a 2 nd coating layer made of calcium phosphate, a 3 rd coating layer made of aluminum phosphate, and a 4 th coating layer made of aluminum hydroxide.
The total amount of the coating layer is preferably within a range of 2 to 15% by weight in terms of oxide for titanium dioxide particles. When the content is 2% by weight or less, sufficient photochemical stability cannot be obtained. When the content is 15% by weight or more, light scattering by the titanium dioxide particles becomes weak and sufficient hiding power cannot be obtained.
CeO for titanium dioxide particles in the amount of the first coating layer 1 made of cerium phosphate2The content is preferably in the range of 0.05 to 0.5% by weight in terms of the weight. When the content is 0.05% by weight or less, sufficient photochemical stability cannot be obtained. If the weight percentage is 0.5% or more, a yellow phase is liable to develop, and the performance as a white pigment is deteriorated.
The amount of the 2 nd or 3 rd coating layer made of aluminum phosphate is based on Al for titanium dioxide particles2O3Is converted into its weightThe percentage is preferably in the range of 2 to 8%. When the content is 2% by weight or less, sufficient photochemical stability cannot be obtained. When the content is 8% by weight or more, light scattering by the titanium dioxide particles becomes weak and sufficient hiding power cannot be obtained.
The amount of the 3 rd or 2 nd coating layer made of calcium phosphate is preferably in the range of 0.5 to 5% by weight in terms of CaO with respect to the titanium dioxide particles. If the content is 0.5% by weight or less, sufficient photochemical stability may not be obtained. When the content is 5% by weight or more, the dispersibility of the titanium dioxide particles is deteriorated, and sufficient whiteness and hiding power cannot be obtained.
The amount of the 4 th coating layer made of aluminum hydroxide is equal to that of Al for titanium dioxide particles2O3The weight percentage of the compound is preferably in the range of 2 to 5% by weight. When the weight percentage is 2% or less, the isoelectric point of the titanium dioxide particles at the time of beating is significantly lower than that of ordinary titanium dioxide particles, and it is not suitable for a papermaking step which is a step of making a decorative paper. When the weight percentage is 5% or more, light scattering by the titanium dioxide particles becomes weak and sufficient hiding power cannot be obtained.
P for phosphoric acid compound for forming cerium phosphate, aluminum phosphate and calcium phosphate2O5The weight percentage of the compound is preferably in the range of 2 to 10% by weight. If the content is 2% by weight or less, sufficient photochemical stability may not be obtained. When the content is 10% by weight or more, light scattering by the titanium dioxide particles becomes weak and sufficient hiding power cannot be obtained.
In the present invention, titanium dioxide particles are dispersed in water, and then a phosphorus compound, a cerium compound, an aluminum compound, and a calcium compound are added to the dispersion to form a coating layer composed of cerium phosphate, aluminum phosphate, calcium phosphate, and aluminum hydroxide on the surface of the titanium dioxide particles in step (1).
In the coating of cerium phosphate in the step (1), the cerium compound is preferably cerium sulfate, cerium nitrate or cerium chloride. The phosphoric acid compound is preferably phosphoric acid.
In the coating of aluminum phosphate in the step (1), the aluminum compound is preferably aluminum sulfate or sodium aluminate. The phosphoric acid compound is preferably at least 1 selected from phosphoric acid, phosphate, polyphosphate, metaphosphate, ultraphosphate perphosphate.
In the coating of calcium phosphate in the step (1), the calcium compound is preferably calcium hydroxide, calcium chloride, calcium nitrate or calcium acetate. The phosphoric acid compound is preferably at least 1 selected from phosphoric acid, phosphate, polyphosphate, metaphosphate, ultraphosphate perphosphate.
In the coating with aluminum hydroxide in the step (1), the aluminum compound is preferably sodium aluminate or aluminum sulfate. The acid for neutralizing the acid is preferably sulfuric acid or hydrochloric acid, and the base is preferably sodium hydroxide.
The invention has the beneficial effects that: the titanium dioxide particles having the coating layer of the present invention not only retain their properties as a white pigment but also suppress the photocatalytic activity possessed by titanium dioxide itself. Therefore, the coating can be stably applied to the aspects of coating, plastics, decorative paper and the like.
Drawings
FIG. 1 is a schematic diagram of a diammonium hydrogen phosphate (DAP) aqueous solution coated on the surface of limestone buildings.
Detailed Description
The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.
Example 1
Water was added to rutile type titanium dioxide having an average particle diameter of 0.26 μm obtained by vapor phase oxidation of titanium tetrachloride, and sodium hexametaphosphate in an amount of 0.2% by weight based on the titanium dioxide was further added thereto and ground by sand milling to adjust the slurry concentration to 300 g/L. Heating to 70 deg.C, adding CeO to titanium dioxide particles2Adding 0.2% by weight of cerium sulfate aqueous solution, stirring for 20 min, and adding P2O5An aqueous solution of phosphoric acid was added in an amount of 0.3% by weight to form a 1 st coating layer. After stirring for 20 minutes, Al was added to the titanium dioxide particles2O3Stirring an aqueous solution of aluminum sulfate at a concentration of 3% by weight, adding a solution of aluminum sulfate P to the mixture for 20 minutes2O5An aqueous phosphoric acid solution was prepared in an amount of 4% by weight. After stirring for another 20 minutes, the pH of the solution was adjusted to 5.0 to 5.5 by adding an aqueous sodium hydroxide solution to form a coating layer 2. After stirring for 20 minutes, P was added2O5An aqueous solution of diammonium hydrogen phosphate was stirred for 20 minutes in an amount of 2.5% by weight, an aqueous solution of calcium chloride was added in an amount of 1.5% by weight in an amount of CaO, and after stirring for another 20 minutes, an aqueous solution of sodium hydroxide was added to adjust the pH to 9.0, thereby forming a coating layer 3. After stirring for 20 minutes, Al for titanium dioxide particles was added while maintaining pH 8.52O3Sodium aluminate solution and sulfuric acid aqueous solution were added in an amount of 3% by weight on a reduced basis to form a 4 th coating layer. Stirring and curing for 40 minutes, filtering the slurry, washing, drying by an airflow dryer, and grinding and crushing by steam.
Example 2
Water was added to rutile type silica having an average particle diameter of 0.26 μm obtained by vapor phase oxidation of titanium tetrachloride, and sodium hexametaphosphate in an amount of 0.2% by weight based on titanium dioxide was further added thereto and ground by sand milling to adjust the slurry concentration to 300 g/L. After heating to 70 ℃, 0.2% by weight of an aqueous cerium sulfate solution was added to the titanium dioxide particles in terms of CeO2, and after stirring for 20 minutes, 0.3% by weight of an aqueous phosphoric acid solution was added thereto in terms of P2O5, thereby forming the first coating layer 1. After stirring for 20 minutes, P was added2O5An aqueous solution of diammonium hydrogen phosphate was prepared in an amount of 2.5% by weight. After stirring for another 20 minutes, an aqueous solution of calcium chloride was added in an amount of 1.5% by weight in terms of CaO, and an aqueous solution of sodium hydroxide was added to adjust the pH to 9.0, thereby forming a 2 nd coating layer. After stirring for 20 minutes, Al was added to the titanium dioxide particles2O3Stirring an aqueous solution of aluminum sulfate at a concentration of 3% by weight, adding a solution of aluminum sulfate P to the mixture for 20 minutes2O5An aqueous phosphoric acid solution was prepared in an amount of 4% by weight. Stirring for another 20 minutes, adding hydrochloric acid aqueous solution to adjust the pH to 5.0-5.5Forming a 3 rd coating layer. After stirring for 20 minutes, Al for titanium dioxide particles was added while maintaining pH 8.52O3Sodium aluminate solution and sulfuric acid aqueous solution were added in an amount of 3% by weight on a reduced basis to form a 4 th coating layer. After stirring and curing for 40 minutes, filtering the slurry, washing, drying by an airflow dryer, and then grinding and crushing by steam.
Example 3
The same procedure as in example 1 was carried out except that the coating layer 3 composed of calcium phosphate of example 1 was not coated. This operation was the same as in example 2, in which no 2 nd coating made of calcium phosphate was applied.
[ evaluation of light resistance of decorative paper ]
25g of bleached kraft pulp was added to 750mL of deionized water and vigorously agitated for 2 minutes using a coater-refinder beater refiner. The number of revolutions of the refiner was reduced, and 7.5g of a titanium dioxide sample (30% by weight based on the pulp) and 0.03g of aluminum sulfate were added and stirred for 5 minutes. The slurry was poured into a 5000mL beaker, and deionized water was added to 4500mL for beating. A paper sample 1 of 140g/m2 was prepared by sucking the slurry through a paper machine equipped with an 80-mesh screen of 16cm in diameter under reduced pressure while passing 400ml of the slurry. This paper sample 1 was pressed at 3kg/cm2 for 3 minutes and then dried at 50 ℃ for 10 minutes to prepare a paper sample 2. After immersing paper sample 2 in a heated Melamine formaldehyde resin 50% aqueous solution, the mixture was air-dried by one hour to prepare paper sample 3. The light-resistant sample was prepared by laminating a paper sample 3, a core-stock core material impregnated with a phenol resin, and 7 layers of a laminate paper prepared by laminating them at 140 ℃ and 80kg/cm2 for 15 minutes. The upper half of the light-resistant test specimen was covered with an aluminum plate and subjected to light resistance test using an ATLAS Ci4000 Xenon Weather Ometer under the following test conditions: 30 ℃, humidity of 50 percent, 340nm and illumination intensity of 0.5W/m2And the test time is 360 h. L, a and b before and after xenon lamp irradiation were measured to obtain L-value change Δ L and color difference Δ E.
Light resistance evaluation results
Comparative examples 1 and 2 were used for the current decorative paper chlorination process products.
According to the present invention, it is considered that the titanium dioxide pigment having the 1 st coating layer composed of cerium phosphate, the 2 nd coating layer composed of aluminum phosphate, the 3 rd coating layer composed of calcium phosphate and the 4 th coating layer composed of aluminum hydroxide, and the 1 st coating layer composed of cerium phosphate, the 2 nd coating layer composed of calcium phosphate, the 3 rd coating layer composed of aluminum phosphate and the 4 th coating layer composed of aluminum hydroxide is much more excellent in light resistance than the titanium dioxide pigment product used for decorative paper at present.
Claims (3)
1. A titanium dioxide pigment characterized by: a titanium dioxide pigment comprising titanium dioxide particles as a base material and having a 1 st coating layer composed of cerium phosphate, a 2 nd coating layer composed of aluminum phosphate, a 3 rd coating layer composed of calcium phosphate and a 4 th coating layer composed of aluminum hydroxide on the surface thereof;
or a titanium dioxide pigment comprising titanium dioxide particles as a base material and having a 1 st coating layer composed of cerium phosphate, a 2 nd coating layer composed of calcium phosphate, a 3 rd coating layer composed of aluminum phosphate and a 4 th coating layer composed of aluminum hydroxide on the surface thereof;
the total amount of the coating layer is 2-15% in terms of the weight percentage of oxide for titanium dioxide particles;
the amount of the first coating layer 1 made of cerium phosphate was set to be CeO for titanium dioxide particles2The converted weight percentage is in the range of 0.05-0.5%;
the amount of the 2 nd or 3 rd coating layer made of aluminum phosphate is such that Al is used for titanium dioxide particles2O3The converted weight percentage is within the range of 2-8%;
the amount of the 3 rd or 2 nd coating layer made of calcium phosphate is in the range of 0.5 to 5% by weight in terms of CaO relative to the titanium dioxide particles;
the amount of the 4 th coating layer made of aluminum hydroxide is Al for the titanium dioxide particles2O3The converted weight percentage is within the range of 2-5%;
phosphoric acid compounds for forming cerium phosphate, aluminium phosphate and calcium phosphate, with P2O5The converted weight percentage is within the range of 2-10%.
2. The titanium dioxide pigment of claim 1, wherein: the phosphoric acid compound for forming cerium phosphate, aluminum phosphate and calcium phosphate is at least 1 selected from the group consisting of phosphoric acid, phosphate, polyphosphate, metaphosphate and perphosphate.
3. A process for producing a titanium dioxide pigment according to any one of claims 1 or 2, characterized in that: base titanium dioxide particles are dispersed in water, and components containing phosphorus, cerium, aluminum, and calcium are added and combined to form a coating layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910009825.2A CN111410853B (en) | 2019-01-05 | 2019-01-05 | Titanium dioxide pigment and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910009825.2A CN111410853B (en) | 2019-01-05 | 2019-01-05 | Titanium dioxide pigment and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111410853A CN111410853A (en) | 2020-07-14 |
| CN111410853B true CN111410853B (en) | 2021-07-06 |
Family
ID=71488815
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910009825.2A Active CN111410853B (en) | 2019-01-05 | 2019-01-05 | Titanium dioxide pigment and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111410853B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112175420A (en) * | 2020-10-09 | 2021-01-05 | 安徽金星钛白（集团）有限公司 | Rutile type titanium dioxide crude product with high light resistance and preparation method and application thereof |
| CN114736536A (en) * | 2022-04-28 | 2022-07-12 | 河南佰利联新材料有限公司 | Preparation method of titanium dioxide for decorative paper |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103224717A (en) * | 2013-03-18 | 2013-07-31 | 中国科学院宁波材料技术与工程研究所 | Preparation method of composite coating titanium dioxide pigment |
| CN104073052A (en) * | 2014-06-15 | 2014-10-01 | 安徽奥邦新材料有限公司 | Novel composite white pigment and preparation method thereof |
| CN105658731A (en) * | 2013-12-13 | 2016-06-08 | 克罗内斯国际公司 | Titanium dioxide composite pigments containing calcium phosphate and method for the production thereof |
| CN106752109A (en) * | 2016-11-18 | 2017-05-31 | 漯河兴茂钛业股份有限公司 | A kind of preparation method of titanium dioxide used for decorative paper |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7304011B2 (en) * | 2004-04-15 | 2007-12-04 | W.R. Grace & Co. -Conn. | Compositions and processes for reducing NOx emissions during fluid catalytic cracking |
-
2019
- 2019-01-05 CN CN201910009825.2A patent/CN111410853B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103224717A (en) * | 2013-03-18 | 2013-07-31 | 中国科学院宁波材料技术与工程研究所 | Preparation method of composite coating titanium dioxide pigment |
| CN105658731A (en) * | 2013-12-13 | 2016-06-08 | 克罗内斯国际公司 | Titanium dioxide composite pigments containing calcium phosphate and method for the production thereof |
| CN104073052A (en) * | 2014-06-15 | 2014-10-01 | 安徽奥邦新材料有限公司 | Novel composite white pigment and preparation method thereof |
| CN106752109A (en) * | 2016-11-18 | 2017-05-31 | 漯河兴茂钛业股份有限公司 | A kind of preparation method of titanium dioxide used for decorative paper |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111410853A (en) | 2020-07-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5237830B2 (en) | Titanium dioxide pigment having high opacity and method for producing the same | |
| JP5199894B2 (en) | Titanium dioxide pigment coated with hollow body and method for producing the same | |
| JP5363459B2 (en) | Preparation of titanium dioxide pigments treated with coprecipitated mixed oxides | |
| EP0406194B2 (en) | Process for coating titanium dioxide pigments | |
| AU2003251000B2 (en) | Method for surface treatment of a titanium dioxide pigment | |
| CN110698883B (en) | Titanium dioxide pigment and preparation method thereof | |
| CN111334092B (en) | Titanium dioxide for decorative paper and preparation method | |
| US20060078485A1 (en) | Process of making a water dispersible titanium dioxide pigment useful in paper laminates | |
| CN107574711B (en) | Production method of titanium dioxide for decorative paper | |
| CN111410853B (en) | Titanium dioxide pigment and preparation method thereof | |
| US5700318A (en) | Durable pigments for plastic | |
| CN110669359A (en) | Surface treatment process of special titanium dioxide for papermaking | |
| EP2742180B1 (en) | Pigment for paper and paper laminate | |
| US9096762B2 (en) | Method for surface treatment of inorganic pigment particles | |
| CA2849773C (en) | Treated inorganic core particles having improved dispersability | |
| JP7228601B2 (en) | Treated titanium dioxide pigment, its method of manufacture, and its use in papermaking | |
| AU2013206052B2 (en) | Surface treatment method for making high durability universal titanium dioxide rutile pigment | |
| US3676167A (en) | Rutile titanium dioxide pigment for paper laminates | |
| CN114456621A (en) | Preparation method of titanium dioxide for decorative paper |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |