阅读说明：本技术 一种改性纳米硫酸钡的制备方法及其应用 (Preparation method and application of modified nano barium sulfate ) 是由 郑明东 胡广齐 陈焰 候宏兵 冼慧敏 于 2021-01-06 设计创作，主要内容包括：本发明公开了一种改性纳米硫酸钡的制备方法及其应用,将原料碳酸钡和硫酸通过直接沉淀法制得硫酸钡沉淀,再将硫酸钡沉淀分散成浆液,加入改性剂对硫酸钡进行改性,最后过滤、干燥、过筛、气流分级,制得改性纳米硫酸钡。本发明制备方法简单,制得的改性纳米硫酸钡粉体分散性好、粒径小,耐热性好,应用于制备高温工程塑料的母粒,在成本和力学性能不变的情况下,能大幅度提高产品的耐高温性。(The invention discloses a preparation method and application of modified nano barium sulfate. The preparation method is simple, and the prepared modified nano barium sulfate powder has good dispersibility, small particle size and good heat resistance, is applied to preparing master batches of high-temperature engineering plastics, and can greatly improve the high-temperature resistance of products under the condition of not changing the cost and the mechanical property.)

1. A preparation method of modified nano barium sulfate is characterized by comprising the following steps: the method comprises the following steps:

(1) adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 40-60%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 10-120min, and controlling the pH value to be 0.5-3 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 6.5-10.5, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 70-90 parts by weight of the prepared barium sulfate precipitate, 90-150 parts by weight of purified water and 0.5-5 parts by weight of a dispersing agent into a high-speed mixer, stirring at a high speed of 1000-1400 revolutions/min for 30-120min, and then stirring at a low speed of 50-200 revolutions/min for 30-60min to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on the barium sulfate, wherein the weight of the modifier is 0.1-5% of the weight of the precipitated barium sulfate, stirring for 10-30 minutes at the stirring speed of 1000-;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude modified barium sulfate product, wherein the mesh number of a screen is 20-100 meshes, and the air flow classification pressure is 0.6-0.9MPa, so as to prepare the modified nano barium sulfate.

2. The preparation method of the modified nano barium sulfate according to claim 1, characterized in that: in the step (2), the dispersant is one or more of EBS, pentaerythritol ester and a composite coupling agent.

3. The preparation method of the modified nano barium sulfate according to claim 1, characterized in that: the modifier in the step (3) is selected from one or more of sodium dodecyl sulfate, sodium stearate, titanate coupling agent, sodium dodecyl sulfate and sodium dodecyl benzene sulfonate.

4. The modified nano barium sulfate applied to preparing the high-temperature engineering plastic master batch is characterized in that: prepared by the preparation method of the modified nano barium sulfate of any one of claims 1 to 3.

Technical Field

The invention relates to the technical field of preparation and application of inorganic nano powder, in particular to a preparation method and application of modified nano barium sulfate.

Background

The nano barium sulfate has important structural characteristics such as quantum effect, size effect, surface effect and the like, and has become an important novel high-grade functional filling filler in recent years. The method has wide application prospect in various industrial fields such as rubber, plastic, printing ink, coating, papermaking and the like, and also has wide application prospect in the aspects of medicine, ceramics, cement, composite materials and the like.

At present, the production process of nano barium sulfate mainly comprises two processes, one is a physical process and the other is a chemical process. The physical method is to sand the dispersant, natural barium sulfate and zirconia beads in water solution in a sand mill in first, second, third and other stages until reaching the required nanometer size, and then to filter press, dry and depolymerize to obtain the nanometer barium sulfate. The chemical method is a synthesis method in which a barium salt such as barium chloride, barium sulfide, or barium carbonate, a compound containing barium ions such as barium hydroxide, a soluble sulfate such as sodium sulfate, potassium sulfate, or ammonium sulfate, or a compound containing sulfate ions such as sulfuric acid are subjected to a substitution reaction or a neutralization reaction to produce nano barium sulfate.

The nano barium sulfate prepared by the physical method has the advantages of irregular particle size, wide distribution, more impurities, low whiteness, easy secondary agglomeration, high oil absorption value, difficult dispersion, low glossiness, more process steps, poor quality stability and difficult large-scale industrialization. The nano barium sulfate prepared by a chemical method has the obvious advantages of regular spherical shape, narrow distribution, high whiteness, less impurities and the like, but still has the defects of easy agglomeration, poor dispersibility and the like, and particularly when the nano barium sulfate is applied to master batches with the filling amount of more than 80%, the defects of difficult processing, large current of processing equipment, poor dispersibility, easy yellowing and the like always appear.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a preparation method and application of modified nano barium sulfate powder which has high filling capacity, good dispersibility and no color change at high temperature.

In order to achieve the above object, the present invention adopts the following technical solutions:

a preparation method of modified nano barium sulfate comprises the following steps:

(1) adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 40-60%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 10-120min, and controlling the pH value to be 0.5-3 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 6.5-10.5, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 70-90 parts by weight of the prepared barium sulfate precipitate, 90-150 parts by weight of purified water and 0.5-5 parts by weight of a dispersing agent into a high-speed mixer, stirring at a high speed of 1000-1400 revolutions/min for 30-120min, and then stirring at a low speed of 50-200 revolutions/min for 30-60min to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on the barium sulfate, wherein the weight of the modifier is 0.1-5% of the weight of the precipitated barium sulfate, stirring for 10-30 minutes at the stirring speed of 1000-;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude modified barium sulfate product, wherein the mesh number of a screen is 20-100 meshes, and the air flow classification pressure is 0.6-0.9MPa, so as to prepare the modified nano barium sulfate.

Preferably, the dispersant in the step (2) is one or more of EBS, pentaerythritol ester and a composite coupling agent.

Preferably, the modifier in the step (3) is selected from one or more of sodium dodecyl sulfate, sodium stearate, titanate coupling agent, sodium dodecyl sulfate and sodium dodecyl benzene sulfonate.

The modified nano barium sulfate prepared by the preparation method is applied to preparing master batches of high-temperature engineering plastics.

The invention has the beneficial effects that: the modified nano barium sulfate powder prepared by the invention has good dispersibility, small particle size and good heat resistance, is applied to preparing master batches of high-temperature engineering plastics, and does not change color at high temperature.

Drawings

FIG. 1 is a TEM image of a modified nano barium sulfate powder obtained in example 1 of the present invention;

FIG. 2 is a TEM image of a modified nano barium sulfate powder obtained in example 2 of the present invention;

FIG. 3 is a TEM image of a modified nano barium sulfate powder obtained in example 3 of the present invention;

FIG. 4 is a TEM image of a modified nano barium sulfate powder obtained in example 4 of the present invention;

FIG. 5 is a TEM image of a modified nano barium sulfate powder obtained in example 5 of the present invention;

FIG. 6 is a TEM image of a modified nano barium sulfate powder obtained in example 6 of the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

The reagents or instruments used in the present invention are not indicated by manufacturers, and are all conventional products commercially available.

Example 1

(1) Adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 40%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 10min, and controlling the pH value to be 0.5 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 6.5, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 70 parts by weight of the prepared barium sulfate precipitate, 90 parts by weight of purified water and 0.5 part by weight of a dispersing agent into a high-speed mixer, stirring at a high speed of 1000 revolutions per minute for 30 minutes, and then stirring at a low speed of 50 revolutions per minute for 30 minutes to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on barium sulfate, wherein the weight of the modifier is 0.1 percent of the weight of the precipitated barium sulfate, stirring for 10 minutes at the stirring speed of 1000 revolutions per minute, then performing reduced pressure filtration, and drying at 200 ℃ to obtain a crude product of modified barium sulfate;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude modified barium sulfate product, wherein the mesh number of a screen is 20 meshes, and the air flow classification pressure is 0.6MPa, so as to prepare the modified nano barium sulfate.

Example 2

(1) Adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 60%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 30min, and controlling the pH value to be 0.8 to obtain barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 6.5, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 80 parts by weight of the prepared barium sulfate precipitate, 100 parts by weight of purified water and 1 part by weight of dispersing agent into a high-speed mixer, stirring at a high speed of 1200 revolutions per minute for 60 minutes, and then stirring at a low speed of 40 minutes at a stirring speed of 100 revolutions per minute to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on barium sulfate, wherein the weight of the modifier is 0.5 percent of the weight of the precipitated barium sulfate, stirring for 20 minutes at the stirring speed of 1200 revolutions per minute, then performing reduced pressure filtration, and drying at 250 ℃ to obtain a crude product of modified barium sulfate;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude modified barium sulfate product, wherein the mesh number of a screen is 30 meshes, and the air flow classification pressure is 0.6MPa, so as to prepare the modified nano barium sulfate.

Example 3

(1) Adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 45%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 60min, and controlling the pH value to be 1 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 7, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 90 parts by weight of the prepared barium sulfate precipitate, 120 parts by weight of purified water and 2 parts by weight of dispersing agent into a high-speed mixer, stirring at a high speed of 1400 revolutions per minute for 90 minutes, and then stirring at a low speed of 50 minutes at a stirring speed of 150 revolutions per minute to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on barium sulfate, wherein the weight of the modifier is 5% of that of the precipitated barium sulfate, stirring for 30 minutes at the stirring speed of 1400 revolutions per minute, then performing reduced pressure filtration, and drying at 300 ℃ to obtain a crude product of modified barium sulfate;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude product of the modified barium sulfate, wherein the mesh number of a screen is 50 meshes, and the air flow classification pressure is 0.8MPa, so as to prepare the modified nano barium sulfate.

Example 4

(1) Adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 50%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 80min, and controlling the pH value to be 2 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 8, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 75 parts by weight of the prepared barium sulfate precipitate, 150 parts by weight of purified water and 3 parts by weight of dispersing agent into a high-speed mixer, stirring at a high speed of 1300 revolutions per minute for 120min, and then stirring at a low speed of 60min for 200 revolutions per minute to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on barium sulfate, wherein the weight of the modifier is 4% of the weight of the precipitated barium sulfate, stirring for 20 minutes at the stirring speed of 1100 r/min, then filtering under reduced pressure, and drying at 280 ℃ to prepare a crude modified barium sulfate product;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude product of the modified barium sulfate, wherein the mesh number of a screen is 100 meshes, and the air flow classification pressure is 0.9MPa, so as to prepare the modified nano barium sulfate.

Example 5

(1) Adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 55%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 90min, and controlling the pH value to be 3 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 9, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 85 parts by weight of the prepared barium sulfate precipitate, 140 parts by weight of purified water and 4 parts by weight of dispersing agent into a high-speed mixer, stirring at a high speed of 1100 revolutions per minute for 60 minutes, and then stirring at a low speed of 35 minutes at a stirring speed of 90 revolutions per minute to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on barium sulfate, wherein the weight of the modifier is 4% of the weight of the precipitated barium sulfate, stirring for 20 minutes at the stirring speed of 1100 r/min, then filtering under reduced pressure, and drying at 280 ℃ to prepare a crude modified barium sulfate product;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude modified barium sulfate product, wherein the mesh number of a screen is 80 meshes, and the air flow classification pressure is 0.7 MPa, so as to prepare the modified nano barium sulfate.

Example 6

(1) Adding barium carbonate powder into purified water, and stirring to form a barium carbonate suspension, wherein the mass concentration of barium carbonate in the suspension is 60%; dropwise adding sulfuric acid into 100 parts by weight of barium carbonate suspension, finishing dropwise adding at a constant speed within 120min, and controlling the pH value to be 2.5 to prepare barium sulfate slurry; adding caustic soda into the barium slurry, adjusting the pH value to 10.5, filtering, washing with water until the washing liquid is neutral, and preparing barium sulfate precipitate;

(2) adding 80 parts by weight of the prepared barium sulfate precipitate, 130 parts by weight of purified water and 5 parts by weight of dispersing agent into a high-speed mixer, stirring at a high speed of 1200 revolutions per minute for 40min, and then stirring at a low speed of 45min, wherein the stirring speed is 100 revolutions per minute, so as to prepare barium sulfate dispersed slurry;

(3) adding a modifier into the slurry to perform surface treatment on barium sulfate, wherein the weight of the modifier is 4% of the weight of the precipitated barium sulfate, stirring for 10 minutes at the stirring speed of 1200 r/min, then filtering under reduced pressure, and drying at 220 ℃ to obtain a crude product of modified barium sulfate;

(4) and (3) carrying out vibration screening and air flow classification on the prepared crude product of the modified barium sulfate, wherein the mesh number of a screen is 60 meshes, and the air flow classification pressure is 0.8MPa, so as to prepare the modified nano barium sulfate.

The performance detection method comprises the following steps:

FIG. 1 is a TEM image showing modified nano-barium sulfate obtained in examples 1 to 6, and it can be seen from FIG. 1 that the obtained product is nano-sized.

The particle size of the Nano barium sulfate prepared by the invention is measured by a Malvern particle size tester (Nano-s 90);

the whiteness is measured by a whiteness meter (Kenicamidean CM2300D), and the higher the value is, the higher the whiteness is;

the dispersibility is tested by a master batch pressure tester, the master batch passes through a 1300-mesh sieve, and the pressure does not rise in the testing process.

Table 1: comparison of Properties of modified Nano barium sulfate powders obtained in examples 1 to 6

	Average particle diameter (D50)	Whiteness test (CIE 10 degree)	Dispersibility
				Example 1	65nm	98.2	The pressure does not rise
Example 2	70nm	98.0	The pressure does not rise
				Example 3	62nm	98.6	The pressure does not rise
Example 4	80nm	98.3	The pressure does not rise
				Example 5	58nm	98.3	The pressure does not rise
Example 6	75nm	98.0	The pressure does not rise

It can be known from table 1 that the modified nano barium sulfate powder prepared in examples 1-6 has good dispersibility, high whiteness, small particle size and significantly better performance than similar products in the market.

Preparing the modified nano barium sulfate prepared in the step 5 into the engineering plastic filling master batch by taking the following steps as main bodies:

weighing 50-70 parts by weight of modified nano barium sulfate powder, 0.5-3 parts by weight of dispersant, 0.1-0.5 part by weight of antioxidant and 40-50 parts by weight of carrier resin; putting the modified nano barium sulfate powder and the dispersing agent into a high-speed mixer, heating to 120 ℃ and uniformly stirring at high speed, adding the antioxidant and the carrier resin, and stirring for 3-5min to obtain a mixed material; and (3) transferring the mixed material into a double-screw extruder, controlling the temperature at 200-.

Wherein the dispersant is one or more of EBS, pentaerythritol ester and a composite coupling agent, the antioxidant is one or more of antioxidant-1010, antioxidant-168, antioxidant-264, antioxidant-BHT, antioxidant-450 and antioxidant-300, and the carrier resin is one or more of acrylonitrile-butadiene-styrene copolymer, polycarbonate, ethylene terephthalate, polybutylene terephthalate and polyamide.

The heat resistance is that the double-screw granulation does not change color in the process of processing the master batch at 200-300 ℃, the original color of the powder can be kept, the better the heat resistance is, and the test results are shown in table 2.

Table 2: examples 7 to 12 of master batches based on modified barium nanosulfate

Example 7

Example 8

Example 9

Example 10

Example 11

Example 12

Modified nano barium sulfate

50 portions of

60 portions of

65 portions of

70 portions of

55 portions of

70 portions of

Dispersing agent

0.5 part of EBS

1 part of pentaerythritol

2 parts of composite coupling agent

3 parts of EBS

2.5 parts of pentaerythritol

1 part of composite coupling agent

Antioxidant agent

0.1 part of antioxidant-1010

0.2 portion of antioxidant-168

0.3 portion of antioxidant-264

0.4 part of antioxidant BHT

0.2 part of antioxidant-450

0.5 part of antioxidant-300

Carrier resin

40 parts of acrylonitrile-butadiene-styrene copolymer

45 parts of polycarbonate

50 parts of polyethylene terephthalate

50 parts of polybutylene terephthalate

45 parts of polyamide

48 parts of polycarbonate

Temperature of high speed mixer

100℃

110℃

120℃

100℃

120℃

115℃

Granulation temperature

200℃

250℃

300℃

300℃

270℃

225℃

Screw rotation speed

300 revolutions per minute

350 revolutions per minute

400 revolutions per minute

350 revolutions per minute

450 rpm

450 rpm

Heat resistance

Does not change color

Does not change color

Does not change color

Does not change color

Does not change color

Does not change color

The data show that the modified nano barium sulfate powder prepared by the invention has good dispersibility, good heat resistance and no color change at high temperature, and the average particle size is controlled to be 58-80 nm.

Those skilled in the art to which the present invention pertains can also make appropriate alterations and modifications to the above-described embodiments, in light of the above disclosure. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.