A kind of high whiteness barium sulfate and its preparation process

Abstract

The invention relates to the field of barium sulfate. In order to solve the problem that the existing barium sulfate coated by titanium dioxide has poor compatibility with an organic system, a high-whiteness barium sulfate and a preparation process thereof are provided. The method comprises: S100, adding superfine barium sulfate powder into water and stirring to obtain slurry; water: superfine barium sulfate powder=1:1.5-1:1; S200, adding titanium tetrachloride into the slurry and heating and reacting under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 20kHz-40kHz; the slurry: titanium tetrachloride=2:1-10:3; the heating temperature is 45-65°C, and the heating time is 0.5-2h; S300, adding a silane coupling agent into the primary reaction material for reaction, and then spray drying to obtain the high-whiteness barium sulfate. The preparation process provided by the present invention utilizes the intermediate product of titanium tetrachloride hydrolysis to coat barium sulfate under an ultrasonic environment, thereby improving the dispersibility and adsorption capacity of the barium sulfate and improving the binding force between the barium sulfate and the silane coupling agent through the coating. The presence of the silane coupling agent also enables the barium sulfate to have good compatibility in the organic system.

Description

Technical Field

[0001] The invention relates to the field of barium sulfate, and in particular to high-whiteness barium sulfate and a preparation process thereof. Background Art

[0002] Barium sulfate, as a new type of inorganic material, is widely used in many fields, such as coatings, inks, paints, plastics, papermaking, rubber and other industrial fields, because of its advantages such as high specific surface area, high activity and good dispersibility. The addition of barium sulfate can not only improve the performance of the product, but also reduce the economic cost by replacing titanium dioxide. However, barium sulfate has the properties of hydrophilicity and oleophobicity, and there is a large polarity difference between it and the polymer matrix, so it is easy to agglomerate in the polymer, and its dispersibility is poor, which reduces its mechanical properties; on the other hand, since nano barium sulfate has high surface activity, it is very easy to agglomerate or agglomerate between adjacent particles, which affects its application in production. Therefore, the prior art usually performs surface modification on barium sulfate, among which inorganic coating modification is one of the common modification methods, and metal oxides such as titanium dioxide, silicon dioxide or zinc oxide are usually selected. In order to improve the whiteness of barium sulfate, titanium dioxide is more often used for coating. However, the bonding between titanium dioxide and barium sulfate is mostly van der Waals force, which is weak, and the compatibility of titanium dioxide with organic systems is also low. Therefore, the amount of barium sulfate added needs to be controlled when preparing downstream products. Summary of the invention

[0003] The purpose of the present invention is to provide a high-whiteness barium sulfate and a preparation process thereof, so as to solve the problem that the existing barium sulfate coated with titanium dioxide has poor compatibility with an organic system.

[0004] The embodiments of the present invention are implemented by the following technical solutions:

[0005] A preparation process of high-whiteness barium sulfate, comprising:

[0006] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1.5-1:1;

[0007] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 20kHz-40kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1-10:3; the heating temperature is 45-65°C, and the heating time is 0.5-2h;

[0008] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:2-8:1.

[0009] Barium sulfate is insoluble in water and acid, has stable chemical properties, and has the function of absorbing x-rays and gamma rays. It is widely used in many industrial fields such as coatings, inks, paints, plastics, papermaking, rubber, etc., and is an indispensable functional filler. In order to further improve the performance of barium sulfate, barium sulfate is often surface modified, among which barium sulfate coated with titanium dioxide is one of the common modification methods. The use of titanium dioxide can improve the whiteness and dispersibility of barium sulfate products. However, the binding degree of titanium dioxide and barium sulfate and the compatibility of titanium dioxide with organic systems will affect the performance of subsequent products. For example, during the long-term use of plastics, titanium dioxide may precipitate from the surface of plastics. In order to improve the binding degree of titanium dioxide-coated barium sulfate in common systems while ensuring the whiteness of barium sulfate products, the applicant has improved the modification process of barium sulfate.

[0010] Ultrafine barium sulfate powder has a large specific surface area and high surface energy. When suspended in a solution, it is affected by van der Waals forces, has poor dispersibility, is easily agglomerated, and causes particle growth. The present invention adds titanium tetrachloride to the slurry twice. When adding once, the hydrolysis product of titanium tetrachloride is mainly titanium hydroxychloride by controlling the reaction conditions, and the agglomeration of titanium hydroxychloride is reduced by an ultrasonic environment and the dispersibility of barium sulfate is improved, so that titanium hydroxychloride can be evenly coated on the surface of barium sulfate. Preliminary coating of hydroxychloride on the surface of barium sulfate can improve the dispersibility and adsorption capacity of barium sulfate. In addition, the conventional silane coupling agent has a weak binding force with barium sulfate. After the preliminary coating of hydroxychloride on the surface of barium sulfate, the present invention can be combined with one end of the silane coupling agent through the hydroxyl group in the hydroxychloride, and the other end of the silane coupling agent has a high degree of binding with the organic system, so that the stability of barium sulfate in plastic or coating systems is better in the present invention, thereby reducing the precipitation of titanium dioxide on the surface of barium sulfate. In addition, by controlling the amount of silane coupling agent, the hydroxy chloride still retains a part of the hydroxyl group, thereby improving the dispersibility of barium sulfate in various systems in this case, so that the preparation of downstream products can reduce the amount of surfactant or use no surfactant. During the reaction of the silane coupling agent, the hydrolysis product of titanium tetrachloride will continue to hydrolyze. The inlet air temperature of the spray drying method can be selected as 200°C, and the outlet air temperature can be selected as 40°C. The hydrolysis product of titanium tetrachloride can be further decomposed into titanium dioxide by spray drying. In addition, since the present invention adopts the spray drying method, there are certain requirements for the fluidity of the system, and the barium sulfate in the system of the present invention has good dispersibility, so the spray drying method can also be used without using a surfactant.

[0011] Preferably, after spray drying in S300, a primary product is obtained, the primary product is mixed with water and stirred once, an organic surfactant is added during the first stirring process, and then a coupling agent is added for a second stirring, the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the first stirring rate is 700-1200r / min, and the second stirring rate is 80-150r / min.

[0012] Organic surfactant refers to a surfactant containing an organic group. In order to increase the binding force of titanium dioxide in an organic system, in addition to increasing the binding force of titanium dioxide's carrier: barium sulfate in an organic system, the present invention also increases the binding force between titanium dioxide and barium sulfate, reduces the possibility of titanium dioxide detaching from the surface of barium sulfate, and further reduces the migration of titanium dioxide in the organic system. The combination of an organic surfactant and the surface of barium sulfate allows organic groups to exist on the surface of barium sulfate, and then the organic groups and titanium dioxide are bridged by a coupling agent to increase the degree of binding between titanium dioxide and barium sulfate. Since titanium dioxide and barium sulfate are combined by physical adsorption or van der Waals force, they are soft agglomerates and the binding force is not high. Therefore, the two can be separated by reasonably controlling the primary stirring speed, and the addition of a surfactant can also prevent the separated titanium dioxide from soft agglomerating with barium sulfate again. The speed of the secondary stirring is lower, and its purpose is more to improve the uniformity of the reaction system.

[0013] Preferably, the organic surfactant added in S300 includes one or more of polyoxyethylene ether sulfate, fatty alcohol polyoxyethylene ether phosphate and sodium lauryl alcohol polyether sulfate.

[0014] Since the present invention needs to utilize the whiteness of titanium dioxide, the surfactant needs to have high selectivity in the system. The present invention screens the types of surfactants. The chloride ions in titanium hydroxychloride are not directly bonded to titanium, but are arranged in the outer coordination boundary and can be replaced by surfactants of the same charge, which can improve the selectivity and binding degree of the surfactant.

[0015] Preferably, after the organic surfactant is added, the stirring is stopped and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 4500 Hz-6000 Hz, and the reaction temperature is 90-150°C.

[0016] In order to further improve the selectivity of the surfactant, the optimal parameters of the reaction system were determined through experiments.

[0017] Preferably, the coupling agent in S300 includes one or more of isopropyl tri(dioctyl pyrophosphoryl) titanate, isopropyl tri(dodecylbenzenesulfonyl) titanate or di(dioctyl pyrophosphoryl) titanium oxyacetate.

[0018] Preferably, in parts by weight, the reaction system in S300 includes: 80-120 parts of the primary product, 1-4 parts of the organic surfactant and 2-3 parts of the coupling agent.

[0019] Preferably, in S300, the reaction time after adding the silane coupling agent to the primary reaction material is 3-5 hours, and the reaction temperature is 100-150°C.

[0020] The purpose of the reaction time after adding the silane coupling agent in the present invention being longer than that of conventional technical means is to make the hydrolysis product of titanium tetrachloride tend to be more metatitanic acid by reasonably extending the reaction temperature. In addition, by narrowing the range of the reaction temperature, the reaction temperature is not only suitable for further hydrolysis of the hydrolysis product, but also suitable for the coupling reaction of the silane coupling agent, reducing the temperature change operation and simplifying the operation process.

[0021] Preferably, the particle size of the ultrafine barium sulfate powder is 0.05-1.2 μm.

[0022] By controlling the particle size of the initial raw materials, the particle size of the final product, high-whiteness barium sulfate, will not be too large, and the gaps between the slight agglomerations in the organic system will not be too large, making it difficult for the liquid in the system to enter. After drying, air gaps can be retained, increasing the refractive index difference of each substance in the system. When applied to coating systems, it can increase hiding power.

[0023] Preferably, the silane coupling agent includes one or more of KH-570, KH-550, APTMS and DL602.

[0024] A high-whiteness barium sulfate produced by the preparation process.

[0025] The present invention has at least the following beneficial effects:

[0026] The preparation process provided by the present invention utilizes the intermediate product of titanium tetrachloride hydrolysis to coat barium sulfate under an ultrasonic environment, thereby improving the dispersibility and adsorption capacity of the barium sulfate and improving the binding force between the barium sulfate and the silane coupling agent through the coating, and the presence of the silane coupling agent enables the barium sulfate to have good compatibility in the organic system; by controlling the amount of the silane coupling agent, a part of the hydroxyl chloride is retained, thereby improving the dispersibility of the product in the downstream product preparation system and making the subsequent spray drying method easier to implement. DETAILED DESCRIPTION

[0027] In order to make the purpose, method scheme and advantages of the embodiments of the present invention clearer, the method scheme in the embodiments of the present invention is clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Embodiment 1: A process for preparing high whiteness barium sulfate, comprising:

[0029] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0030] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 20kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 45°C, and the heating time is 1h;

[0031] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 8:1, and the silane coupling agent is KH-570.

[0032] Embodiment 2: A process for preparing high whiteness barium sulfate, comprising:

[0033] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0034] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 40kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 45°C, and the heating time is 1h;

[0035] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 8:1, and the silane coupling agent is KH-570.

[0036] Embodiment 3: A process for preparing high whiteness barium sulfate, comprising:

[0037] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0038] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 45°C, and the heating time is 1h;

[0039] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 8:1, and the silane coupling agent is KH-570.

[0040] Embodiment 4: A process for preparing high whiteness barium sulfate, comprising:

[0041] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0042] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 65°C, and the heating time is 1h;

[0043] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 8:1, and the silane coupling agent is KH-570.

[0044] Embodiment 5: A process for preparing high whiteness barium sulfate, comprising:

[0045] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0046] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0047] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 8:1, and the silane coupling agent is KH-570.

[0048] Embodiment 6: A process for preparing high whiteness barium sulfate, comprising:

[0049] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0050] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0051] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:2, and the silane coupling agent is KH-570.

[0052] Embodiment 7: A process for preparing high whiteness barium sulfate, comprising:

[0053] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0054] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0055] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0056] Comparative Example 1: A process for preparing high-whiteness barium sulfate, comprising:

[0057] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0058] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0059] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 3:2, and the silane coupling agent is KH-570.

[0060] Comparative Example 2: A process for preparing high-whiteness barium sulfate, comprising:

[0061] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0062] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 3h;

[0063] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0064] Comparative Example 3: A process for preparing high-whiteness barium sulfate, comprising:

[0065] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0066] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 90°C, and the heating time is 1h;

[0067] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0068] Blank example: barium sulfate ultrafine powder raw material.

[0069] Test 1: The high whiteness barium sulfate and barium sulfate ultrafine powder raw materials prepared according to the preparation process of Examples 1-7 and Comparative Examples 1-3 were subjected to whiteness test and compatibility test. The test results are shown in Table 1.

[0070] The whiteness test uses a whiteness meter. The high whiteness barium sulfate produced by each process is divided into 5 groups for testing and the average value is taken.

[0071] Compatibility test steps:

[0072] Preparation of the material to be tested: By weight, 50 parts of polypropylene and 20 parts of high-whiteness barium sulfate were placed in a high-speed mixer and mixed for 5 minutes. The mixed raw materials were then placed in a screw extruder for extrusion and granulation to obtain the material to be tested. The processing temperature was 200°C and the screw speed was 500r / min.

[0073] Test: After placing the sample into the XK-8070 rubber ozone aging test chamber (Kunshan Xiangke Testing Instrument Co., Ltd.), set the experimental parameters, ozone concentration (volume fraction): 100×10 -8; Temperature in the box: 60℃; Relative humidity: 60%, gas replacement flow rate: 15mm / s; Test time: 6h, take out the sample after the test, and judge the frost spraying condition of the sample after 10min. The test results are divided into 4 levels.

[0074] Grade A: No frost, no frost is visible on the surface of the sample;

[0075] Grade B: Slight blooming, the color of the sample surface is obviously reduced, and a thin layer of frost appears;

[0076] Grade C: Moderate frost, with an obvious frost layer on the surface of the specimen;

[0077] Grade D: Severe frosting, with accumulated frost on the surface of the specimen.

[0078] The whiteness of the blank example was 97.15, and the compatibility test result was D.

[0079] Table 1

[0080]

[0081]

[0082] It can be seen from Table 1 that the barium sulfate prepared using the relevant parameters of Examples 1-7 has good whiteness and compatibility, and the product prepared using the relevant parameters of Example 7 has the best performance.

[0083] From the comparison between Comparative Example 1 and Example 7, it can be seen that when the amount of silane coupling agent used increases, the product performance decreases significantly. The applicant speculates that one of the reasons is that the hydroxyl groups on the hydroxychloride are not retained, which affects the dispersibility of barium sulfate and affects the subsequent process operations and downstream product performance.

[0084] From the comparison between Comparative Examples 2-3 and Example 7, it can be seen that the heating temperature and heating time in S200 significantly affect the product performance. The applicant speculates that one of the reasons is that the degree of hydrolysis of titanium tetrachloride increases, resulting in the intermediate no longer being mainly hydroxychloride, affecting the subsequent process.

[0085] Embodiment 8: A process for preparing high whiteness barium sulfate, comprising:

[0086] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0087] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0088] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0089] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, and during the stirring process, fatty alcohol polyoxyethylene ether phosphate is added, and the stirring is stopped and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, and the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the primary stirring rate is 1200r / min, and the secondary stirring rate is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0090] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 3 hours, and the reaction temperature is 100°C.

[0091] Embodiment 9: A process for preparing high whiteness barium sulfate, comprising:

[0092] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0093] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0094] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0095] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, and during the stirring process, fatty alcohol polyoxyethylene ether phosphate is added and the stirring is stopped once, and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, and the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the primary stirring rate is 700r / min, and the secondary stirring rate is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0096] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 3 hours, and the reaction temperature is 100°C.

[0097] Embodiment 10: A process for preparing high whiteness barium sulfate, comprising:

[0098] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0099] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0100] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0101] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, and during the stirring process, fatty alcohol polyoxyethylene ether phosphate is added and the stirring is stopped once, and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, and the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0102] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 3 hours, and the reaction temperature is 100°C.

[0103] Example 11: A process for preparing high-whiteness barium sulfate, comprising:

[0104] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0105] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0106] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0107] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, and during the stirring process, fatty alcohol polyoxyethylene ether phosphate is added and the stirring is stopped once, and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, and the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0108] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 5 hours, and the reaction temperature is 100°C.

[0109] Example 12: A process for preparing high-whiteness barium sulfate, comprising:

[0110] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0111] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0112] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0113] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, and during the stirring process, fatty alcohol polyoxyethylene ether phosphate is added and the stirring is stopped once, and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, and the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0114] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0115] Example 13: A process for preparing high-whiteness barium sulfate, comprising:

[0116] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0117] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0118] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0119] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, and after adding sodium lauryl polyether sulfate during the stirring process, the stirring is stopped and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the primary stirring rate is 1000r / min, and the secondary stirring rate is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0120] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0121] Example 14: A process for preparing high-whiteness barium sulfate, comprising:

[0122] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0123] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0124] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0125] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, polyoxyethylene ether sulfate is added during the stirring process, the stirring is stopped once and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant and 2 parts of the coupling agent.

[0126] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0127] Comparative Example 4: A process for preparing high-whiteness barium sulfate, comprising:

[0128] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0129] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0130] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0131] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, polyoxyethylene ether sulfate is added during the stirring process, the stirring is stopped once and the reaction temperature of the reaction system is set to 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant, and 2 parts of the coupling agent.

[0132] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0133] Comparative Example 5: A process for preparing high-whiteness barium sulfate, comprising:

[0134] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0135] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0136] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0137] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, polyoxyethylene ether sulfate is added during the stirring process, the stirring is stopped once and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 50°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high whiteness barium sulfate; the stirring rate is 1000r / min for the first time, and the stirring rate for the second time is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant and 2 parts of the coupling agent.

[0138] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0139] Comparative Example 6: A process for preparing high-whiteness barium sulfate, comprising:

[0140] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0141] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 1h;

[0142] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0143] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, polyoxyethylene ether sulfate is added during the stirring process, the stirring is stopped once and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant and 2 parts of the coupling agent.

[0144] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 2 hours, and the reaction temperature is 100°C.

[0145] Comparative Example 7: A process for preparing high-whiteness barium sulfate, comprising:

[0146] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0147] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 90°C, and the heating time is 1h;

[0148] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0149] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, polyoxyethylene ether sulfate is added during the stirring process, the stirring is stopped once and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant and 2 parts of the coupling agent.

[0150] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0151] Comparative Example 8: A process for preparing high-whiteness barium sulfate, comprising:

[0152] S100, adding superfine barium sulfate powder into water and stirring to obtain a slurry; in parts by weight, water:superfine barium sulfate powder=1:1; the average particle size of the superfine barium sulfate powder is 0.08 μm;

[0153] S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 30kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1; the heating temperature is 55°C, and the heating time is 3h;

[0154] S300, adding a silane coupling agent to a primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:1, and the silane coupling agent is KH-570.

[0155] In the S300, after spray drying, the primary product is obtained, the primary product is mixed with water and stirred once, polyoxyethylene ether sulfate is added during the stirring process, the stirring is stopped once and the reaction system is placed in an ultrasonic environment, the ultrasonic power is 5000Hz, the reaction temperature is 120°C, and then isopropyl tri(dodecylbenzenesulfonyl) titanate is added for secondary stirring, the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the rate of the first stirring is 1000r / min, and the rate of the second stirring is 150r / min. In terms of weight parts, the reaction system in S300 includes: 120 parts of the primary product, 2 parts of the organic surfactant and 2 parts of the coupling agent.

[0156] In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 4 hours, and the reaction temperature is 100°C.

[0157] Test 2: The high whiteness barium sulfate prepared according to the preparation process of Examples 8-14 and Comparative Examples 4-8 was subjected to whiteness test and compatibility test. The test method was the same as that of Test 1 above. The test results are shown in Table 2.

[0158] Table 2

[0159]

[0160] From the comparison between Examples 1-7 and Examples 8-14, it can be seen that the subsequent operation of the initial product further improves the performance of the product, especially the compatibility. The optimal test parameters provide relevant data for Example 14.

[0161] From the comparison between Comparative Examples 4-5 and Example 14, it can be seen that after adding the organic surfactant, the presence of the ultrasonic environment and the choice of reaction temperature have little effect on the whiteness of the product, but affect the compatibility of barium sulfate in the organic system. The applicant speculates that the ultrasonic environment and temperature can improve the selectivity of the organic surfactant.

[0162] From the comparison between Comparative Example 6 and Example 14, it can be seen that the reaction time after adding the silane coupling agent affects the compatibility of the product. The applicant speculates that one of the reasons is that the reaction time affects the type of the final hydrolysis product.

[0163] From the comparison between Comparative Example 7 and Comparative Example 3 and the comparison between Comparative Example 8 and Comparative Example 2, it can be seen that when the hydrolysis intermediate of titanium tetrachloride is no longer mainly titanium hydroxychloride, the subsequent process of the initial product has little effect on its performance improvement. The applicant speculates that one of the reasons is that the release of chloride ions after further hydrolysis of hydroxychloride will affect the selectivity of the surfactant.

[0164] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for preparing high whiteness barium sulfate, characterized in that: include: S100, adding ultrafine barium sulfate powder into water and stirring to obtain slurry; In parts by weight, water: barium sulfate ultrafine powder = 1:1.5-1:1; S200, adding titanium tetrachloride to the slurry and heating the slurry under an ultrasonic environment to obtain a primary reaction material; the power of the ultrasound is 20kHz-40kHz; in parts by weight, the slurry: titanium tetrachloride = 2:1-10:3; the heating temperature is 45-65°C, and the heating time is 0.5-2h; S300, adding a silane coupling agent to the primary reaction material for reaction, and then spray drying to obtain high-whiteness barium sulfate; in parts by weight, the primary reaction material: silane coupling agent = 5:2-8:1; In the S300, after spray drying, a primary product is obtained, the primary product is mixed with water and stirred once, an organic surfactant is added during the first stirring process, and then a coupling agent is added for a second stirring, and the solution after the reaction is filtered, washed, and dried to obtain high-whiteness barium sulfate; the first stirring rate is 700-1200r / min, and the second stirring rate is 80-150r / min.

2. The preparation process according to claim 1, characterized in that: The organic surfactant added in S300 includes one or more of polyoxyethylene ether sulfate, fatty alcohol polyoxyethylene ether phosphate and sodium lauryl alcohol polyether sulfate.

3. The preparation process according to claim 1, characterized in that: After the organic surfactant is added, the stirring is stopped and the reaction system is placed in an ultrasonic environment. The power of the ultrasound is 4500 Hz-6000 Hz and the reaction temperature is 90-150°C.

4. The preparation process according to claim 1, characterized in that: The coupling agent in S300 includes one or more of isopropyl tri(dioctyl pyrophosphoryl) titanate, isopropyl tri(dodecylbenzenesulfonyl) titanate or di(dioctyl pyrophosphoryl) titanium oxyacetate.

5. The preparation process according to claim 4, characterized in that: In parts by weight, the reaction system in S300 includes: 80-120 parts of the primary product, 1-4 parts of the organic surfactant and 2-3 parts of the coupling agent.

6. The preparation process according to any one of claims 1 to 5, characterized in that: In S300, the reaction time after adding the silane coupling agent to the primary reaction material is 3-5 hours, and the reaction temperature is 100-150°C.

7. The preparation process according to claim 6, characterized in that: The particle size of the ultrafine barium sulfate powder is 0.05-1.2 μm.

8. The preparation process according to claim 6, characterized in that: The silane coupling agent includes one or more of KH-570, KH-550, APTMS and DL602.

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