Preparation method of barium lanthanum phosphate pigment and filler and application of barium lanthanum phosphate pigment and filler in coating

Abstract

The invention belongs to the technical field of pigments and fillers, and particularly relates to a preparation method of a barium lanthanum phosphate pigment and filler and application of the barium lanthanum phosphate pigment and filler in a coating. The preparation method comprises the following steps: fully grinding a barium source compound, a rare earth lanthanide compound and a phosphorus source compound in proportion, calcining at a high temperature in an air atmosphere, and then fully grinding again to obtain a mixture; and performing high-temperature calcination on the mixture in the air atmosphere again, and fully grinding the product obtained by calcination to obtain the barium lanthanum phosphate pigment filler. The barium lanthanum phosphate pigment filler prepared by the invention is applied to a coating, the corrosion resistance, weather resistance, impact resistance, wear resistance and hardness of the coating can be improved, and the preparation process is simple and convenient and is easy for large-scale production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pigments and fillers, and particularly relates to a preparation method of a barium lanthanum phosphate pigment and filler and application thereof in coatings. BACKGROUND

[0002] As an effective means of protecting metals, anticorrosive coatings are widely used in various industrial fields. As a key component of anticorrosive coatings, antirust pigments play a decisive role in their corrosion resistance. Therefore, the selection and optimization of antirust pigments are of great significance and are the development direction in terms of anticorrosive performance.

[0003] Traditional heavy metal antirust pigments (mainly chromium and lead) have excellent performance and suitable prices, and are widely used in coating formulations. However, the harm of heavy metal antirust pigments has been clearly proven, which can cause harm to the ecological system and human body. The national standard GB30981-2020 clearly limits the amount of heavy metals in coatings and sets an upper limit on the amount. At present, with the control of environmental protection policies, domestic and foreign coating manufacturers are gradually eliminating such antirust pigments and developing environmentally friendly antirust pigments, especially pigments based on rare earth fillers, which are deeply rooted in the hearts of the people.

[0004] Phosphates, as a common environmentally friendly antirust pigment, have significantly lower ecological toxicity than heavy metals and are not high in cost, and are widely used in many coating formulations with low performance requirements. For example, it is applied to steel substrates, and because it is a water-based coating, it has little environmental pollution and is safe to use, so it is widely used in various industries such as petroleum and petrochemical, steel, electric power and aviation. However, its low chemical activity and single anticorrosion mechanism are far inferior to the anticorrosion performance of heavy metal antirust pigments, and cannot meet the requirements of high anticorrosion performance scenes. And the film-forming solidification of the previous phosphate inorganic coating needs to be realized at a relatively high temperature, which further limits its application and promotion.

[0005] Rare earth is a family of 17 metal elements formed by Group III (Sc, Y) and lanthanide elements (La-Lu) with the electronic configuration of [Xe]4f 0-14 5d 1-10 6S 2 As a filler added to coatings, rare earth salts impart unique electromagnetic, chemical, mechanical, thermal, surface, and photophysical properties to the coating.

[0006] As CN109593527A orange red barium yttrium phosphate fluorescent powder and its preparation method, a new type of orange red fluorescent powder is disclosed, which is activated by divalent manganese ions, sensitized by cerium ions and europium ions, and has barium yttrium phosphate as the substrate. CN110283590A lithium barium phosphate blue-green fluorescent powder and its preparation method, a blue-green luminescent lithium barium phosphate fluorescent powder is disclosed, which is prepared by calcining lithium carbonate, inorganic salt of elemental barium and phosphorus, europium oxide and cerium oxide. CN113024244A high thermal expansion coefficient orthophosphate thermal barrier coating material and its preparation method, a high thermal expansion coefficient orthophosphate is disclosed, which is prepared by calcining rare earth oxides, alkali earth metal compounds and P-containing compounds, and is used for coating materials to improve heat resistance. CN116103044A preparation of europium-doped barium borophosphate fluorescent powder self-reduced in air atmosphere, a fluorescent powder is prepared by calcining barium-containing compounds, boron-containing compounds, phosphorus-containing compounds and europium-containing compounds, which is used to solve the problem of tunable fluorescent powder of blue-green light and red light excited by ultraviolet light. CN117487553A fluorescent material, its preparation method and application, a fluorescent powder is prepared by calcining lithium source, barium source, phosphoric acid source and europium source, which is used to present cyan light under ultraviolet excitation. The existing disclosure discloses that the phosphate is prepared by mixing at least two of phosphorus source, alkali metal, alkaline earth metal, transition metal and metalloid as matrix and doping lanthanide series elements, which is used to solve the problems of fluorescent light performance and high temperature resistance, and few attention is paid to physical properties such as corrosion resistance, impact resistance, wear resistance, barrier property, hardness and weather resistance.

[0007] The present application develops a new rare earth phosphate and applies it to water-based paint, so as to improve the physical properties of water-based paint such as corrosion resistance, weather resistance, impact resistance, wear resistance, barrier property and hardness. SUMMARY

[0008] The present application provides a preparation method of barium lanthanum phosphate pigment filler, which is applied to water-based paint, and can improve the physical properties of water-based paint such as corrosion resistance, weather resistance, impact resistance, wear resistance and hardness.

[0009] The technical scheme of the present application is a preparation method of barium lanthanum phosphate pigment filler, which comprises the following steps: (1) The barium source compound, rare earth lanthanide series element compound and phosphorus source compound are fully ground in proportion, calcined at 300-600 DEG C in air atmosphere, and the calcined product is fully ground to obtain a mixture; (2) The mixture is calcined at 500-800 DEG C in air atmosphere, and the calcined product is fully ground to obtain barium lanthanum phosphate pigment filler.

[0010] In step (1), the molar ratio of the barium source compound, the rare earth lanthanide compound, and the phosphorus source compound is 3:0.5-1:3. The barium source compound is selected from any one or any combination of barium oxide, barium carbonate, barium hydroxide, and barium nitrate, preferably barium oxide and / or barium carbonate. The phosphorus source compound is selected from any one or any combination of phosphoric acid, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate, preferably ammonium dihydrogen phosphate. The rare earth lanthanide compound is selected from oxides of rare earth lanthanides, and the rare earth lanthanides are selected from scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, etc., preferably europium oxide or erbium oxide.

[0011] Step (1): Increase the temperature to 300-600℃ at a heating rate of 5-10℃ / min, and calcine at that temperature for 200-600min. Further, increase the temperature to 500-600℃ at a heating rate of 5℃ / min, and calcine at that temperature for 500±50min.

[0012] Step (1): After calcination, first slowly cool down to 50-100℃ and then quickly cool down to 25-40℃. Then grind the calcined product thoroughly for 30-45 minutes, or grind and mix it evenly with a ball mill.

[0013] In step (1), the barium source compound, rare earth lanthanide compound and phosphorus source compound are ground thoroughly for 20-30 minutes.

[0014] Step (2): Increase the temperature to 500-800℃ at a heating rate of 5-10℃ / min, and calcine at that temperature for 500-800min. Further, increase the temperature to 800℃ at a heating rate of 5℃ / min, and calcine at that temperature for 800±50min.

[0015] Step (2): After calcination, first slowly cool down to 50-100℃ and then quickly cool down to 25-40℃. Then grind the calcined product thoroughly for 30-60 minutes, or grind it evenly with a ball mill and pass it through a 200-400 mesh sieve.

[0016] In step (2), the lanthanide element in the lanthanum barium phosphate pigment filler is selected from any one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, preferably europium or erbium. As one embodiment, the lanthanum barium phosphate pigment filler obtained in step (2) is europium barium phosphate Ba3Eu(PO4)3 or erbium barium phosphate Ba3Er(PO4)3.

[0017] This invention also provides a lanthanum barium phosphate pigment filler, prepared by the method described above. The lanthanum barium phosphate pigment filler prepared by the high-temperature solid-state method of this invention has the advantages of low impurities and fluorescence.

[0018] The lanthanum barium phosphate pigment filler prepared by the above preparation method of the present invention is used to prepare coatings, and the resulting coatings have advantages such as corrosion resistance, weather resistance, impact resistance, wear resistance, and high hardness.

[0019] A coating containing barium lanthanum phosphate pigment and filler, comprising the following components in parts by weight: Lanthanum barium phosphate pigment filler: 2-10 parts by weight, preferably 3-8 parts by weight; the lanthanum barium phosphate pigment filler is preferably derived from barium europium phosphate Ba3Eu(PO4)3 or barium erbium phosphate Ba3Er(PO4)3; Waterborne resin: 50-100 parts by weight, preferably 80-100 parts by weight; the waterborne resin is selected from any one of acrylic resin, polyurethane resin, epoxy resin, chloroether resin, and alkyd resin, preferably acrylic resin.

[0020] Furthermore, the coating also contains the following components in parts by weight: Wetting agent: 0.2-2 parts by weight, wherein the wetting agent is selected from any one of G-100, G-003, and G-007; Dispersant: 0.4-8 parts by weight, wherein the dispersant is selected from any one of G-5040, G-5100, G-5300, SILCO CT 1008, and Genapol 2158.

[0021] Furthermore, the coating also contains the following components in parts by weight: pH adjuster: 0.2-0.8 parts by weight, wherein the pH adjuster is selected from any one of ammonia, sodium hydroxide, potassium hydroxide, and organic amine; Film-forming aid: 1-1.6 parts by weight, wherein the film-forming aid is selected from any one of propylene glycol phenyl ether and alcohol ester (e.g., C12 alcohol ester); Defoamer: 0.07-0.3 parts by weight, wherein the defoamer is selected from any one of polysiloxane and polyether (e.g., defoamer 825); Leveling agent: 0.2-0.8 parts by weight, wherein the leveling agent is selected from any one of polyols (e.g., propylene glycol or butylene glycol), polyvinyl alcohol, and polyolefin fiber resins (e.g., leveling agent 3020); Thickener: 0.2-0.5 parts by weight, wherein the thickener is selected from any one of cellulose, polyacrylate, polyacrylamide, and polyurethane (e.g., thickener 105A).

[0022] Furthermore, the coating also contains the following components in parts by weight: Rust inhibitor: 0.1-0.2 parts by weight, wherein the rust inhibitor is selected from 30% NaNO3 or 1020E; Bactericide: 0.1-0.2 parts by weight, wherein the bactericide is selected from DF35 or TB2015.

[0023] Furthermore, the coating also contains deionized water and / or polyethylene glycol as solvents, in an amount of 18-25 parts by weight.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. The lanthanum barium phosphate prepared by this invention emits light corresponding to rare earth elements under ultraviolet light. For example, both europium barium phosphate and erbium barium phosphate emit red light.

[0025] 2. The rare earth pigments and fillers of the present invention are economical and practical, with a simple preparation process, low cost, no need for special equipment and harsh conditions, easy to achieve large-scale production, and the raw materials used are green and environmentally friendly, with great practical value.

[0026] 3. The rare earth pigments and fillers of the present invention can be added to coatings and can be used in the fields of anti-counterfeiting, anti-flash rust, and anti-corrosion. They can also be used as fluorescent powders. Attached Figure Description

[0027] Figure 1 The X-ray diffraction (XRD) patterns of barium europium phosphate prepared with different molar ratios of raw materials in Example 1 are shown.

[0028] Figure 2 Scanning electron microscope (SEM) images of Eu2O3 (A), Er2O3 (B), Ba3Eu(PO4)3 (C), and Ba3Er(PO4)3 (D). Figure 2 Layered structures were observed in B. Figure 2 C and D reunite briefly.

[0029] Figure 3 This is a particle size analysis diagram of barium europium phosphate prepared by BaCO3:Eu2O3:(NH4)H2PO4 in a molar ratio of 3:0.5:3 (particle size: μm).

[0030] Figure 4 This is the ultraviolet absorption spectrum of barium europium phosphate.

[0031] Figure 5 The fluorescence spectrum is for barium europium phosphate.

[0032] Figure 6 Salt spray resistance test diagrams for acrylic waterborne coatings with different mass fractions of europium barium phosphate. Detailed Implementation

[0033] The technical solution of the present invention will be further described in detail and completely below with reference to embodiments and comparative examples. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer.

[0034] Example 1 I. Preparation of barium europium phosphate a) BaCO3, Eu2O3, and (NH4)H2PO4 were placed in an alumina mortar and grouped according to different molar ratios of BaCO3:Eu2O3:(NH4)H2PO4 to prepare different barium europium phosphate pigments and fillers. For example, the molar ratio of BaCO3:Eu2O3:(NH4)H2PO4 was 3:0.5:3. The total amount of the three was set to 3g. 1.5956g of barium carbonate, 0.4743g of europium oxide, and 0.9301g of ammonium dihydrogen phosphate were weighed and ground thoroughly for 30 min to obtain a mixture. The obtained mixture was placed in a corundum crucible and placed in a muffle furnace. It was calcined in an air atmosphere, heated to 500 ℃ at a heating rate of 5℃ / min, held at that temperature for 500 min, and then slowly cooled to 75℃ before opening the muffle furnace to rapidly cool to 30℃. The product was a white solid granular powder.

[0035] b) Grind the extracted product for 30 min, then heat it to 800 °C in air at a heating rate of 5 °C / min, hold it at that temperature for 800 min, first slowly cool it to 75 °C, then open the muffle furnace to quickly cool it to 30 °C, take out the sample, grind it thoroughly for 60 min, and obtain europium barium phosphate pigment filler, which appears as a white solid powder.

[0036] Table 1 shows the particle size distribution of barium europium phosphate prepared by different molar ratios of BaCO3:Eu2O3:(NH4)H2PO4. Figure 1 The XRD patterns of barium europium phosphate prepared in this embodiment at different molar ratios are shown in the figures. As can be seen from the figures, they all conform to the barium europium phosphate standard card (presumed). Among them, the molar ratio of 3:0.5:3 is the most consistent.

[0037] Figure 3 Table 1 shows the particle size analysis of barium europium phosphate. The high-temperature solid-state method produces larger particle sizes. Ball milling reduces the particle size, resulting in more uniform dispersion in the coating. Table 1 shows that the particle size (D32) of barium europium phosphate after grinding is distributed between 1.892-3.209 μm, and D43 is distributed between 4.167-7.525 μm. The particle size distribution index is between 1.853-2.562 μm. Theoretical calculations show that smaller particle size results in a larger specific surface area. Under smaller particle size conditions, such as 1.892 μm, the specific surface area can reach 3170.785 m². 2 / kg. However, when the particle size is larger, such as 3.209μm, its specific surface area is only 1869.778 m². 2 / kg.

[0038] Figure 5 The fluorescence emission spectrum of barium europium phosphate (BEP) is shown. Under 300 nm light excitation, the emission is mainly distributed in the yellow region around 590 nm and the red region around 612 nm, with the red light emission being the strongest. It can be observed that the peak value of Ba3Eu(PO4)3 in the yellow region is higher than that of the raw material Eu2O3, while its peak value in the red region is lower than that of Eu2O3.

[0039] II. Preparation of Europium Barium Phosphate Coatings Mix 4g of dispersant (SILCO CT 1008), 1g of dispersant (Genapol® 2158), 0.1g of pH adjuster (DMAE), 5g of solvent (PEG400), and 17.9g of solvent (deionized water) until homogeneous (stirring speed 200-400 rpm, stirring time 10-15 min); add 2g of filler barium europium phosphate (molar ratio of barium europium phosphate raw materials BaCO3:Eu2O3:(NH4)H2PO4 is 3:0.5:3, stirring speed 800-1000 rpm, stirring time 60 min) to ensure uniform dispersion of the filler; finally, add 100g of acrylic D 012 emulsion, 1.6g of film-forming aid (alcohol ester twelve), 0.3g of defoamer (825), 0.4g of leveling agent (3020), and 0.1g of... Add rust inhibitor (30% NaNO3) and 0.1g bactericide (10% DF35) (stirring speed 400-500r / min, stirring time 15-20min), and finally add 0.2-0.3g thickener (105A) to obtain europium barium phosphate acrylic coating.

[0040] III. Film Formation of Europium Barium Phosphate Coatings (Solvothermal Evaporation Method) The coating containing europium barium phosphate is ultrasonically dispersed and then coated onto the substrate. It is dried at 20°C for 5-10 minutes, during which solvent molecules diffuse outward from the coating. The coating is then placed in a 50°C drying oven for 30-60 minutes, where the solvent decreases and the polymer molecule concentration increases, forming a tightly connected and uniform continuous coating film, thus obtaining the coating containing europium barium phosphate.

[0041] Example 2 I. Preparation of Barium Erbium Phosphate Filler a) BaCO3, Er2O3, and (NH4)H2PO4 were placed in an alumina mortar, with a molar ratio of BaCO3:Er2O3:(NH4)H2PO4 of 3:0.5:3. The total amount of the three was set to 3g. 1.5740g of barium carbonate, 0.5085g of erbium oxide, and 0.9175g of ammonium dihydrogen phosphate were weighed out and ground thoroughly for 30 min to obtain a mixture. The mixture was placed in a corundum crucible and placed in a muffle furnace. It was calcined in air atmosphere, heated to 500 ℃ at a heating rate of 5℃ / min, held at that temperature for 500 min, and then slowly cooled to 75℃ before opening the muffle furnace to rapidly cool to 30℃. The product was a pink solid granular powder.

[0042] b) Grind the extracted product for 30 min, then heat it to 800 °C in air at a heating rate of 5 °C / min, hold it at that temperature for 800 min, first slowly cool it to 75 °C, then open the muffle furnace to quickly cool it to 30 °C, take out the sample, grind it thoroughly for 60 min, and obtain barium erbium phosphate pigment filler, which appears as a pink solid powder.

[0043] II. Preparation of Barium Erbium Phosphate Coatings Mix 0.4g dispersant (5100), 0.2g pH adjuster (DMAE), 0.2g wetting agent (G-100), 0.2g defoamer (825), and 24ml deionized water until homogeneous (stirring speed 200-400r / min, stirring time 10-15min); add 2.0g barium erbium phosphate filler (stirring speed 800-1000r / min, stirring time 60min) to ensure uniform dispersion of the filler; finally, add 100g acrylic D 012 emulsion, 1.6g film-forming aid (alcohol ester twelve), 0.3g defoamer (825), 0.4g leveling agent (3020), and 0.1g... Add rust inhibitor (30% NaNO3) and 0.1g bactericide (10% DF35) (stirring speed 400-500r / min, stirring time 15-20min), and finally add 0.2-0.3g thickener (105A) to obtain erbium barium phosphate acrylic coating.

[0044] III. Film Formation of Barium Erbium Phosphate Coatings (Solvothermal Evaporation Method) The coating containing barium erbium phosphate is ultrasonically dispersed and then coated onto the substrate. It is dried at 20°C for 5-10 minutes, during which solvent molecules diffuse outward from the coating. The coating is then placed in a 50°C drying oven for 30-60 minutes, which reduces the solvent concentration and increases the polymer molecule concentration, forming a tightly connected and uniform continuous coating film, thus obtaining the coating containing barium erbium phosphate.

[0045] Example 3 I. Preparation of barium europium phosphate a) BaCO3, Eu2O3, and (NH4)H2PO4 were placed in an alumina mortar, with a molar ratio of BaCO3:Eu2O3:(NH4)H2PO4 of 3:1:3. The total amount of the three was set to 3g. 1.3951g of barium carbonate, 0.8294g of europium oxide, and 0.8132g of ammonium dihydrogen phosphate were weighed out and ground thoroughly for 30 min to obtain a mixture. The mixture was placed in a corundum crucible and placed in a muffle furnace. It was calcined in air atmosphere, heated to 500 ℃ at a heating rate of 5℃ / min, held at that temperature for 500 min, and then slowly cooled to 75℃ before opening the muffle furnace to rapidly cool to 30℃. The product was a white solid granular powder.

[0046] b) Grind the extracted product for 30 min, then heat it to 800 °C in air at a heating rate of 5 °C / min, hold it at that temperature for 800 min, first slowly cool it to 75 °C, then open the muffle furnace to quickly cool it to 30 °C, take out the sample, grind it thoroughly for 60 min, and obtain europium barium phosphate pigment filler, which appears as a white solid powder.

[0047] II. Preparation of Europium Barium Phosphate Coatings Wetting agent and dispersant are mixed in a 1:1 mass ratio, i.e., 3.0g of GAXSN® G-100 and GAXSN5300, 0.8g of pH adjuster DMAE, 1.0g of film-forming aid alcohol ester 12, and 20.0g of deionized water are mixed evenly. Then, 0.07g of defoamer 825, 0.8g of leveling agent propylene glycol, and 2.0g of europium barium phosphate are added and stirred until evenly mixed. Finally, 50.0g of waterborne acrylic resin and 0.5g of thickener polyacrylamide are added and stirred until evenly mixed to obtain the europium barium phosphate acrylic coating.

[0048] III. Film Formation of Europium Barium Phosphate Coatings (Solvothermal Evaporation Method) The coating containing europium barium phosphate is ultrasonically dispersed and then coated onto the substrate. It is dried at 20°C for 5-10 minutes, during which solvent molecules diffuse outward from the coating. The coating is then placed in a 50°C drying oven for 30-60 minutes, where the solvent decreases and the polymer molecule concentration increases, forming a tightly connected and uniform continuous coating film, thus obtaining the coating containing europium barium phosphate.

[0049] Comparative Example 1 I. Preparation of barium europium phosphate (Method 2) a) Weigh barium carbonate and europium oxide powders according to the optimal ratio of 3:0.5:3, mix them in an alumina mortar, and grind them thoroughly for 30 min. After grinding, dissolve them in phosphoric acid and stir until the powder is completely dissolved. Place the resulting mixture in an alumina crucible, place the crucible in a muffle furnace, and calcine it in air. Increase the temperature to 600 °C at a rate of 5 °C / min, hold for 500 min, then slowly cool it to 75 °C before opening the muffle furnace to rapidly cool it to 30 °C. The product is a white solid powder.

[0050] b) Grind the extracted product for 30 min, then heat it to 800 °C in air at a heating rate of 5 °C / min, hold it at that temperature for 800 min, first slowly cool it to 75 °C, then open the muffle furnace to quickly cool it to 30 °C, take out the sample, grind it thoroughly for 60 min, and obtain europium barium phosphate pigment filler, which appears as a white solid powder.

[0051] II. Preparation of coatings containing freshly prepared barium europium phosphate Mix 0.4g dispersant (5040), 0.2g pH adjuster (ammonia), 0.2g wetting agent (G-100), 0.2g defoamer (825), and 24ml deionized water until homogeneous (stirring speed 200-400r / min, stirring time 10-15min); add 2g of filler (europium barium phosphate) (stirring speed 800-1000r / min, stirring time 60min) to ensure uniform dispersion of the filler; finally, add 100g of acrylic D 012 emulsion, 1.6g of film-forming aid (alcohol ester twelve), 0.3g of defoamer (825), 0.4g of leveling agent (3020), and 0.1g of... Add rust inhibitor (30% NaNO3) and 0.1g bactericide (10% DF35) (stirring speed 400-500r / min, stirring time 15-20min), and finally add 0.2-0.3g thickener (105A) to obtain europium barium phosphate acrylic coating.

[0052] III. Film formation of coatings containing freshly prepared barium europium phosphate (solvent thermal evaporation method) The coating containing europium barium phosphate is ultrasonically dispersed and then coated onto the substrate. It is dried at 20°C for 5-10 minutes, during which solvent molecules diffuse outward from the coating. The coating is then placed in a 50°C drying oven for 30-60 minutes, where the solvent decreases and the polymer molecule concentration increases, forming a tightly connected and uniform continuous coating film, thus obtaining the coating containing europium barium phosphate.

[0053] Comparative Example 2 I. Preparation of barium europium phosphate a) BaCO3, Eu2O3, and (NH4)H2PO4 were placed in an alumina mortar, with a molar ratio of BaCO3:Eu2O3:(NH4)H2PO4 of 3:0.7:3. The total amount of the three was set to 3g. 1.4386g of barium carbonate, 0.5987g ​​of europium oxide, and 0.9627g of ammonium dihydrogen phosphate were weighed out and ground thoroughly for 30 min to obtain a mixture. The mixture was placed in a corundum crucible and then placed in a muffle furnace. The crucible was calcined in air atmosphere, heated to 500 ℃ at a heating rate of 5℃ / min, held at that temperature for 500 min, and then slowly cooled to 75℃ before the muffle furnace was opened to rapidly cool to 30℃. The product was a white solid granular powder.

[0054] b) Grind the extracted product for 30 min, then heat it to 800 °C in air at a heating rate of 5 °C / min, hold it at that temperature for 800 min, first slowly cool it to 75 °C, then open the muffle furnace to quickly cool it to 30 °C, take out the sample, grind it thoroughly for 60 min, and obtain europium barium phosphate pigment filler, which appears as a white solid powder.

[0055] II. Preparation of Europium Barium Phosphate Coatings Mix 0.6g of dispersant (5300), 0.4g of wetting agent (G-100), 0.2g of defoamer (825), and 28ml of deionized water until homogeneous (stirring speed 200-400r / min, stirring time 10-15min); add 5g of filler barium europium phosphate (stirring speed 800-1000r / min, stirring time 60min) to ensure uniform dispersion of the filler; finally, add 50g of polyurethane resin, 2.2g of film-forming aid (alcohol ester twelve), 0.2g of defoamer (825), 0.2g of leveling agent (3020), 0.1g of rust inhibitor (30%NaNO3), and 0.1g of bactericide (10%DF35) (stirring speed 400-500r / min, stirring time 15-20min), and finally add 0.4g of thickener (105A) to obtain barium europium phosphate polyurethane coating.

[0056] III. Film formation of coatings containing freshly prepared barium europium phosphate (solvent thermal evaporation method) The coating containing europium barium phosphate is ultrasonically dispersed and then coated onto the substrate. It is dried at 20°C for 5-10 minutes, during which solvent molecules diffuse outward from the coating. The coating is then placed in a 50°C drying oven for 30-60 minutes, where the solvent decreases and the polymer molecule concentration increases, forming a tightly connected and uniform continuous coating film, thus obtaining the coating containing europium barium phosphate.

[0057] Comparative Example 3 I. Preparation of Lanthanum Barium Phosphate-Free Coatings Mix 0.8g of wetting agent GAXSN@G-007, 0.8g of dispersant GAXSN-5040, 0.7g of pH adjuster ammonia, 1.6g of film-forming aid alcohol ester 12, and 27.0g of deionized water until homogeneous. Then add 0.1g of defoamer 825 and 1.2g of leveling agent propylene glycol, and stir until homogeneous. Finally, add 50.0g of water-based acrylic resin and 0.2g of thickener polyacrylamide, and stir until homogeneous to obtain a lanthanum barium phosphate-free coating.

[0058] A lanthanum barium phosphate-free coating is uniformly applied to the substrate surface and dried and cured at 50°C to form a film, thus obtaining a lanthanum barium phosphate-free comparative coating.

[0059] In the above applications, the film-forming aid (alcohol ester 12) needs to be mixed with water in a 1:1 ratio.

[0060] The coating films prepared for application cases were evaluated using GB / T 9286-2021, GB / T 6739-2022, GB / T 6742-2007, and GB / T 1732-2020. The adhesion, pencil hardness, flexibility, and impact resistance of the coating films were examined.

[0061] The prepared water-based coating was applied to the substrate, dried and cured to form a film, and the performance of the coating after film formation was tested. The test results are shown in Table 2.

[0062] Table 2. Performance test results of the coatings prepared in Examples 1-3 and Comparative Examples 1-3 As shown in Table 2, the water-based coating containing barium lanthanum phosphate pigment provided by the present invention has excellent impact resistance, solvent resistance, high hardness and corrosion resistance (solvent scrub resistance), and its pencil hardness and impact resistance are higher than those of coatings without barium lanthanum phosphate. An acrylic waterborne coating was prepared according to the description in Example 1. The content of europium barium phosphate in the acrylic waterborne coating was adjusted to 0 wt%, 1 wt%, 2 wt%, 3 wt%, and 5 wt%, respectively, to prepare acrylic waterborne coatings with different europium barium phosphate contents. The salt spray resistance of each acrylic waterborne coating with different europium barium phosphate contents was tested, and the results are as follows: Figure 6 As shown, the water-based coating containing lanthanum barium phosphate pigment and filler provided by this invention has excellent salt spray resistance. The coating containing lanthanum barium phosphate has higher flash rust prevention ability than the coating without lanthanum barium phosphate, and its corrosion resistance time is longer; moreover, all physical indicators meet the relevant national standards.

[0063] In summary, this invention prepares barium lanthanum phosphate from barium, rare earth lanthanum, and phosphoric acid sources via a high-temperature solid-state method. The prepared barium lanthanum phosphate has high purity and good compatibility. When added to coatings, it is easily and uniformly dispersed, closely compatible with the resin matrix of the coating, and can significantly improve the physical properties of water-based coatings, such as flash rust prevention, impact resistance, wear resistance, and hardness, thus expanding the application range of water-based coatings. It can also be prepared as a color paste to provide anti-counterfeiting fluorescent properties for coatings. Furthermore, the amount of rare earth used in the prepared barium lanthanum phosphate is low, reducing production costs. No toxic or harmful substances are added during the preparation process, making it non-toxic, harmless, safe, and environmentally friendly. The process is simple, economical, and practical, requiring no special equipment or harsh conditions, and has low impurity content. After coating, it exhibits red light under ultraviolet light.

[0064] Finally, it should be noted that the above are only some preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a lanthanum barium phosphate pigment filler, characterized in that the steps include... include: (1) The barium source compound, rare earth lanthanide element compound and phosphorus source compound are ground thoroughly in proportion, calcined in air at 300-600℃, and the calcined product is ground thoroughly to obtain a mixture; (2) The mixture is calcined in air at 500-800℃. The calcined product is then thoroughly ground to obtain lanthanum barium phosphate pigment filler.

2. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of barium source compound, rare earth lanthanide element compound and phosphorus source compound is 3:0.5-1:

3.

3. The preparation method according to claim 2, characterized in that, The barium source compound is selected from any one or any combination of barium oxide, barium carbonate, barium hydroxide, and barium nitrate; the phosphorus source compound is selected from any one or any combination of phosphoric acid, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate; and the rare earth lanthanide compound is selected from oxides of rare earth lanthanides.

4. The preparation method according to claim 1, characterized in that, Step (1): Heat to 300-600℃ at a heating rate of 5-10℃ / min, and calcine for 200-600min.

5. The preparation method according to claim 1, characterized in that, Step (1): After calcination, first slowly cool down to 50-100℃ and then quickly cool down to 25-40℃, and then grind the calcined product thoroughly.

6. The preparation method according to claim 1, characterized in that, Step (2): Increase the temperature to 500-800℃ at a rate of 5-10℃ / min, and calcine at that temperature for 500-800min.

7. The preparation method according to claim 1, characterized in that, Step (2): After calcination, first slowly cool down to 50-100℃ and then quickly cool down to 25-40℃, and then grind the calcined product thoroughly.

8. A lanthanum barium phosphate pigment filler, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. A coating containing barium lanthanum phosphate pigment and filler, characterized in that, Contains the following components in parts by weight: Lanthanum barium phosphate pigment filler: 2-10 parts by weight; Water-based resin: 50-100 parts by weight.

10. The coating according to claim 1, characterized in that, The waterborne resin is selected from any one of acrylic resin, polyurethane resin, epoxy resin, chloroether resin, and alkyd resin.

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