阅读说明：本技术 一种涂料专用改性氢氧化钙的制备方法 (Preparation method of modified calcium hydroxide special for coating ) 是由 韦明 于 2020-05-29 设计创作，主要内容包括：本发明公开了一种涂料专用改性氢氧化钙的制备方法,将石灰石粉碎后,过筛,煅烧,加入水、尿素、聚乙二醇和脂肪醇聚氧乙烯醚硫酸钠进行消化反应,过筛,除杂,陈化,制得氢氧化钙乳液加入超声波搅拌器,再加入叠氮苯并咪唑、椰油基羧甲基钠咪唑啉醋酸盐、聚甲基丙烯酸甲酯-丙烯酸丁酯共聚物和稀土偶联剂组成的复配改性剂进行超声分散,得改性氢氧化钙悬浊液；再经压滤机脱水,经干燥,得涂料专用改性氢氧化钙。本发明方法制得的氢氧化钙粉体具有大比表面积、粒径分布均匀,稳定性好、分散性好、补强效果好等优点,与涂料具有很好的相容性及粘结性,能提高在涂料的填充量,降低涂料成本,且工艺简单,成本较低,生产效率高。(The invention discloses a preparation method of modified calcium hydroxide special for paint, which comprises the steps of crushing limestone, sieving, calcining, adding water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate for digestion reaction, sieving, removing impurities, aging to prepare calcium hydroxide emulsion, adding the calcium hydroxide emulsion into an ultrasonic stirrer, adding a compound modifier consisting of azidobenzimidazole, coco-carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent, and performing ultrasonic dispersion to obtain a modified calcium hydroxide suspension; and dehydrating by a filter press, and drying to obtain the special modified calcium hydroxide for the coating. The calcium hydroxide powder prepared by the method has the advantages of large specific surface area, uniform particle size distribution, good stability, good dispersibility, good reinforcing effect and the like, has good compatibility and cohesiveness with the coating, can improve the filling amount of the coating, reduces the coating cost, and has simple process, lower cost and high production efficiency.)

1. A preparation method of modified calcium hydroxide special for paint is characterized by comprising the following steps: the method comprises the following steps:

s1, crushing limestone, sieving, calcining, adding water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate for digestion reaction, and aging to obtain calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, and then adding a compound modifier consisting of azidobenzimidazole, coco-carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent for ultrasonic dispersion, wherein the addition amount of the modifier is 1.5-3.0% of the dry weight of calcium hydroxide, so as to obtain a modified calcium hydroxide suspension;

s3: and dehydrating the modified calcium hydroxide suspension by using a filter press, and drying to obtain the modified calcium hydroxide special for the coating.

2. The preparation method of the special modified calcium hydroxide for the coating according to claim 1, which is characterized by comprising the following steps: the mass ratio of the water, the urea, the polyethylene glycol, the fatty alcohol-polyoxyethylene ether sodium sulfate and the limestone is 6-8:0.01-0.03:0.01-0.03:0.005-0.015: 1.

3. The preparation method of the special modified calcium hydroxide for the coating according to claim 1, which is characterized by comprising the following steps: in the compound modifier, the mass ratio of the azidobenzimidazole to the cocoyl sodium carboxymethyl imidazoline acetate to the polymethyl methacrylate-butyl acrylate copolymer to the rare earth coupling agent is 1-3:3-6:5-10: 1-3.

4. The preparation method of the special modified calcium hydroxide for the coating according to claim 1, which is characterized by comprising the following steps: the calcination is carried out at the temperature of 950 ℃ and 1050 ℃ for 3-5 h.

5. The preparation method of the special modified calcium hydroxide for the coating according to claim 1, which is characterized by comprising the following steps: the digestion reaction is carried out at a temperature of 80-95 ℃.

6. The preparation method of the special modified calcium hydroxide for the coating according to claim 1, which is characterized by comprising the following steps: the ultrasonic dispersion is carried out for 30-60min under the power of 200-400W.

7. The preparation method of the special modified calcium hydroxide for the coating according to claim 1, which is characterized by comprising the following steps: the drying is realized by adopting a pulse airflow dryer.

8. The preparation method of the modified calcium hydroxide specially used for the coating according to claim 7, characterized in that: the feeding speed of the pulse airflow dryer is 200-300kg/h, the drying temperature is 80-110 ℃, and the air speed is 10-15 m/s.

Technical Field

The invention relates to the technical field of preparation of inorganic nonmetallic minerals, in particular to a preparation method of modified calcium hydroxide special for paint.

Background

Calcium hydroxide, also known as slaked or hydrated lime, is formed by the digestion of quicklime with water, usually as a white powdered solid. With the rapid development of industrial modernization and the increasing emphasis of the country on environmental protection, calcium hydroxide has been widely used. For example: the fields of plastics, coatings, environmental protection and the like in the petrochemical industry and the pharmaceutical and food industry. The existing production method of calcium hydroxide in China mainly takes lime as a raw material, hydrochloric acid is added for dissolution, and alkali is added into a calcium chloride solution after impurity removal for precipitation to prepare the calcium hydroxide, but the prepared calcium hydroxide has the defects of low purity, uneven particle size distribution, low activity, instability, specific surface area and the like, and is difficult to meet the requirements of industrial production.

Calcium hydroxide is an important filler in building coatings, but because the calcium hydroxide is unstable, is easy to react with carbon dioxide in the air, and has poor compatibility with the coatings, the uniformity and the dispersibility are difficult to realize in the preparation process of the materials, so that the performance of the materials is reduced. Therefore, the calcium hydroxide needs to be reasonably modified so as to have a large filling amount in the coating and endow the coating with more excellent performance.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method of modified calcium hydroxide special for paint. The calcium hydroxide powder prepared by the method has the advantages of large specific surface area, good stability, good dispersibility, good reinforcing effect and the like, has good compatibility and cohesiveness with the coating, improves the filling amount in the coating, and reduces the coating cost.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a preparation method of modified calcium hydroxide special for paint comprises the following steps:

s1, crushing limestone, sieving, calcining, adding water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate for digestion reaction, and aging to obtain calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, and then adding a compound modifier consisting of azidobenzimidazole, coco-carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent for ultrasonic dispersion, wherein the addition amount of the modifier is 1.5-3.0% of the dry weight of calcium hydroxide, so as to obtain a modified calcium hydroxide suspension;

s3: and dehydrating the modified calcium hydroxide suspension by using a filter press, and drying to obtain the modified calcium hydroxide special for the coating.

Further, the mass ratio of the water, the urea, the polyethylene glycol and the fatty alcohol-polyoxyethylene ether sodium sulfate to the limestone is 6-8:0.01-0.03:0.01-0.03:0.005-0.015: 1.

Furthermore, in the compound modifier, the mass ratio of the azidobenzimidazole to the cocoyl sodium carboxymethyl imidazoline acetate to the polymethyl methacrylate-butyl acrylate copolymer to the rare earth coupling agent is 1-3:3-6:5-10: 1-3.

Further, the calcination is carried out at the temperature of 950-1050 ℃ for 3-5 h.

Further, the digestion reaction is carried out at a temperature of 80-95 ℃.

Further, the ultrasonic dispersion is performed for 30-60min under the power of 200-400W.

Further, the drying is drying by using a pulse airflow dryer. The feeding speed of the pulse airflow dryer is 200-300kg/h, the drying temperature is 80-110 ℃, and the air speed is 10-15 m/s.

Compared with the prior art, the invention has the advantages and beneficial effects that:

1. according to the method, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate are added in the digestion reaction, so that the specific surface area of calcium hydroxide can be increased, the prepared powder is good in stability, and the dispersibility of calcium hydroxide can be improved by polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate.

2. According to the invention, the compound agent consisting of the azidobenzimidazole, the cocoanut oil sodium carboxymethyl imidazoline acetate, the polymethyl methacrylate-butyl acrylate copolymer and the rare earth coupling agent is added for ultrasonic modification, so that the dispersibility of the calcium hydroxide can be improved, an organic-inorganic hybrid network structure is formed, the compatibility and the cohesiveness of the calcium hydroxide and the coating are improved, the binding force between materials is enhanced, the reinforcing effect is improved, and the addition amount of the calcium hydroxide can be increased.

3. The method adopts the pulse airflow dryer to dry the calcium carbonate, so that the drying and heating are uniform, the efficiency is high, the modifier can be better wrapped on the surface of the calcium hydroxide, and the dispersion of the calcium hydroxide powder is facilitated.

4. The calcium hydroxide powder prepared by the method has the advantages of large specific surface area, good stability, good dispersibility, good reinforcing effect and the like, has good compatibility and cohesiveness with the coating, improves the filling amount in the coating, reduces the coating cost, and has simple process, lower cost, high production efficiency and good market popularization prospect.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments. It should be emphasized that the following description is merely exemplary in nature and is not intended to limit the scope of the invention or its application.

Example 1

A preparation method of modified calcium hydroxide special for paint comprises the following steps:

s1, crushing limestone to a particle size of 4mm, sieving, calcining at 1000 ℃ for 4h, carrying out digestion reaction on water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate according to a mass ratio of the limestone to the lime of 6:0.02:0.015:0.01 at 90 ℃, and aging to obtain calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, adding a compound modifier consisting of azidobenzimidazole, cocoyl carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent in a mass ratio of 2:5:7:1, and performing ultrasonic dispersion for 40min under the power of 250W, wherein the addition amount of the modifier is 2.5% of the dry weight of calcium hydroxide, so as to obtain a modified calcium hydroxide suspension;

s3: and (3) dehydrating the modified calcium hydroxide suspension by using a filter press, and drying by using a pulse airflow dryer, wherein the feeding speed of the pulse airflow dryer is 250kg/h, the drying temperature is 90 ℃, and the air speed is 12m/s, so that the modified calcium hydroxide special for the coating is obtained.

The calcium hydroxide of this example was found to have a specific surface area of 32.43m²The oil absorption value is 0.126 mL/g. 100g of modified calcium hydroxide is put into 300ml of water, stirred evenly and has no sedimentation phenomenon after being placed for 15 days. Thus, the modified calcium hydroxide can be used as an excellent filler for water-based coating materials.

Example 2

A preparation method of modified calcium hydroxide special for paint comprises the following steps:

s1, crushing limestone to 8mm, sieving, calcining at 1050 ℃ for 3h, carrying out digestion reaction on water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate according to the mass ratio of the limestone to the lime of 7:0.015:0.02:0.008 at 85 ℃, and aging to prepare calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, adding a compound modifier consisting of azidobenzimidazole, cocoyl carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent in a mass ratio of 2:5:8:3, and performing ultrasonic dispersion for 50min under the power of 300W, wherein the addition amount of the modifier is 1.8 percent of the dry weight of calcium hydroxide to obtain a modified calcium hydroxide suspension;

s3: and (3) dehydrating the modified calcium hydroxide suspension by using a filter press, and drying by using a pulse airflow dryer, wherein the feeding speed of the pulse airflow dryer is 300kg/h, the drying temperature is 100 ℃, and the air speed is 15m/s, so that the modified calcium hydroxide special for the coating is obtained.

The calcium hydroxide of the present example was found to have a specific surface area of 29.18m²The oil absorption value is 0.135 mL/g. 100g of modified calcium hydroxide is put into 300ml of water, stirred evenly and has no sedimentation phenomenon after being placed for 15 days. Thus, the modified calcium hydroxide can be used as an excellent filler for water-based coating materials.

Example 3

A preparation method of modified calcium hydroxide special for paint comprises the following steps:

s1, crushing limestone to a particle size of 4mm, sieving, calcining at 1000 ℃ for 4h, carrying out digestion reaction on water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate according to a mass ratio of the limestone to the lime of 6:0.025:0.01:0.012 at 90 ℃, and aging to obtain calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, adding a compound modifier consisting of azidobenzimidazole, cocoyl carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent in a mass ratio of 1:4:9:2, and performing ultrasonic dispersion for 30min under the power of 350W, wherein the addition amount of the modifier is 2.4% of the dry weight of calcium hydroxide, so as to obtain a modified calcium hydroxide suspension;

s3: and (3) dehydrating the modified calcium hydroxide suspension by using a filter press, and drying by using a pulse airflow dryer, wherein the feeding speed of the pulse airflow dryer is 250kg/h, the drying temperature is 100 ℃, and the air speed is 15m/s, so that the modified calcium hydroxide special for the coating is obtained.

The calcium hydroxide of the present example was found to have a specific surface area of 34.65m²The oil absorption value is 0.123 mL/g. 100g of modified calcium hydroxide is put into 300ml of water, stirred evenly and has no sedimentation phenomenon after being placed for 15 days. Thus, the modified calcium hydroxide can be used as an excellent filler for water-based coating materials.

Example 4

A preparation method of modified calcium hydroxide special for paint comprises the following steps:

s1, crushing limestone to a particle size of 4mm, sieving, calcining at 1050 ℃ for 4h, carrying out digestion reaction on water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate according to a mass ratio of 8:0.015:0.03:0.01 to lime at 95 ℃, and aging to prepare calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, adding a compound modifier consisting of azidobenzimidazole, cocoyl carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent in a mass ratio of 2:5:8:1, and performing ultrasonic dispersion for 60min under the power of 200W, wherein the addition amount of the modifier is 2.5% of the dry weight of calcium hydroxide, so as to obtain a modified calcium hydroxide suspension;

s3: and (3) dehydrating the modified calcium hydroxide suspension by using a filter press, and drying by using a pulse airflow dryer, wherein the feeding speed of the pulse airflow dryer is 200kg/h, the drying temperature is 90 ℃, and the air speed is 12m/s, so that the modified calcium hydroxide special for the coating is obtained.

The calcium hydroxide of this example was found to have a specific surface area of 45.81m²The oil absorption value is 0.108 mL/g. 100g of modified calcium hydroxide is put into 300ml of water, stirred evenly and has no sedimentation phenomenon after being placed for 15 days. Thus, the modified calcium hydroxide can be used as an excellent filler for water-based coating materials.

Comparative example 1

S1, crushing limestone to a particle size of 4mm, sieving, calcining at 1050 ℃ for 4h, carrying out digestion reaction at 95 ℃ according to a water-cement ratio of 6:1, and aging to obtain calcium hydroxide emulsion;

s2: adding an ultrasonic stirrer into a calcium hydroxide emulsion, adding a compound modifier consisting of azidobenzimidazole, cocoyl carboxymethyl sodium imidazoline acetate, polymethyl methacrylate-butyl acrylate copolymer and a rare earth coupling agent in a mass ratio of 2:5:8:1, and performing ultrasonic dispersion for 60min under the power of 200W, wherein the addition amount of the modifier is 2.5% of the dry weight of calcium hydroxide, so as to obtain a modified calcium hydroxide suspension;

s3: and (3) dehydrating the modified calcium hydroxide suspension by using a filter press, and drying by using a pulse airflow dryer, wherein the feeding speed of the pulse airflow dryer is 200kg/h, the drying temperature is 90 ℃, and the air speed is 12m/s, so that the modified calcium hydroxide special for the coating is obtained.

The specific surface area of the calcium hydroxide in the example is 5.86m²The oil absorption value is 0.187 mL/g. 100g of modified calcium hydroxide is put into 300ml of water, evenly stirred and has the phenomenon of layered settlement after being placed for 15 days.

Comparative example 2

S1, crushing limestone to a particle size of 4mm, sieving, calcining at 1050 ℃ for 4h, carrying out digestion reaction on water, urea, polyethylene glycol and fatty alcohol-polyoxyethylene ether sodium sulfate according to a mass ratio of 8:0.015:0.03:0.01 to lime at 95 ℃, and aging to prepare calcium hydroxide emulsion;

s2: and (3) dehydrating the modified calcium hydroxide suspension by using a filter press, and drying by using a pulse airflow dryer, wherein the feeding speed of the pulse airflow dryer is 200kg/h, the drying temperature is 90 ℃, and the air speed is 12m/s, so that the modified calcium hydroxide special for the coating is obtained.

The specific surface area of the calcium hydroxide in the example is 42.19m²The oil absorption value is 0.379 mL/g. 100g of modified calcium hydroxide is put into 300ml of water, stirred evenly and placed for 5 hours, and then the phenomenon of layered settlement occurs.

The foregoing is a more detailed description of the invention in connection with specific/preferred embodiments and is not intended to limit the practice of the invention to those descriptions. It will be apparent to those skilled in the art that various substitutions and modifications can be made to the described embodiments without departing from the spirit of the invention, and such substitutions and modifications are to be considered as within the scope of the invention.