CN102188929B - Carboxylate terpolymer dispersing agent and preparation process thereof - Google Patents

Abstract

The invention relates to a copolymer dispersant, a carboxylate terpolymer dispersant and a preparation process thereof. The disadvantages of the prior art are: the molecular weight is difficult to control in the synthesis process, and the dispersion effect is not ideal. The invention consists of the following substances in mass ratio: 10-50 parts of styrene, 10-80 parts of methacrylic acid, 10-50 parts of hydroxypropyl acrylate; the number-average relative molecular weight of the terpolymer is 1000-20000. The advantages of the present invention are: the carboxylate terpolymer dispersant containing methacrylic acid unit has good water solubility and good adaptability to the pH value of the dispersion system; the dispersant has ideal polymerization degree and carboxyl group Content, through the steric hindrance effect and electrostatic repulsion, the dispersed substance is dispersed and stabilized; the preparation process is simple, the operation is easy, the production cycle is short, the cost is low, no environmental pollution, and it is suitable for industrial scale production.

Description

A kind of carboxylate terpolymer dispersant and its preparation process

technical field

The invention relates to a copolymer dispersant, in particular to a carboxylate terpolymer dispersant and a preparation process thereof.

Background technique

Dispersants play a role in dispersing and stabilizing the dispersed substances, and have important applications in industries such as pigments, dyes, aqueous coal slurry, and pesticides. The disadvantages of traditional small molecule dispersants are: the adsorption on the surface of solid particles is not firm, and it is easy to dissociate from the surface to cause re-aggregation or precipitation. Carboxylate copolymer dispersants can stabilize the system through steric hindrance and electrostatic repulsion, and have better dispersion effects than small molecule dispersants; Compared with dispersants, carboxylate copolymer dispersants are not sensitive to ions, pH and temperature of the dispersion system, and can significantly reduce the viscosity of the system. When this type of copolymer is used as a dispersant, the molecular weight is low, generally between several thousand to tens of thousands, and the molecular weight is crucial to the dispersion ability of the dispersant. Due to the relatively high polymerization activity of the monomers used in the preparation of such copolymers, the control of polymer molecular weight has become a key technology for the preparation of such dispersants. The present inventor has done a lot of work on polymer molecular weight control before, such as Chinese patents CN200810201806.1, CN200810201805.7, "Synthesis and Dispersibility of Acrylic Copolymer Dispersants" published in the Journal of Process Engineering. In addition, the methods for controlling the molecular weight of polymers in this technical field also include: using mercapto compounds as chain transfer agents to control polymer molecular weights, EP1304314; using metal salts as molecular weight regulators, patent document CN1085570; Polymerization in an alcohol mixed solvent achieves the purpose of controlling the molecular weight of the polymer, such as document US4301226 and the like. The disadvantages of these methods are: substances with pungent smell are introduced into the product, pollute the environment, increase the difficulty of post-processing, and the production cost is expensive.

In the prior art, carboxylate copolymer dispersants are more and more widely used, but the synthesis process of this type of dispersants still has difficult technical problems such as difficult to control the molecular weight and unsatisfactory dispersion effect. Therefore, it is very necessary to invent a carboxylate terpolymer dispersant with excellent dispersion stability, low preparation cost and environment-friendly and its preparation process.

Contents of the invention

The object of the present invention is a carboxylate terpolymer dispersant with excellent dispersion stability, low preparation cost and environmental friendliness and its preparation process.

To achieve the above object, the technical scheme adopted in the present invention is as follows:

A kind of carboxylate terpolymer dispersant, is made up of following mass ratio material:

Styrene 10-50 parts

Methacrylic acid 10-80 parts

Hydroxypropyl acrylate 10-50 parts;

The number average relative molecular weight of the terpolymer is 1000-20000.

The preparation technology of carboxylate terpolymer dispersant, the steps are as follows:

a) Add a certain amount of double-distilled water and an aqueous solution of a chain transfer agent into the reaction flask, stir and heat to 60-90°C;

b) Adding styrene, methacrylic acid, hydroxypropyl acrylate and initiator solution dropwise to the above solution, the addition is completed within 1 to 5 hours, and the heat preservation reaction is carried out for 2 to 10 hours;

c) Stir the solution obtained in step b, cool it to room temperature, neutralize the carboxylic acid in the system with a base, and the neutralization amount is 50% to 100% of the number of moles of carboxyl groups;

d) Spray drying the carboxylate terpolymer solution prepared in step c to obtain the target dispersant powder.

The chain transfer agent is sodium bisulfite and isopropanol, and the dosage is 0.5-10% of the total mass of monomers.

The initiator is ammonium persulfate, and the dosage is 2-16% of the total mass of monomers.

The alkali is one or both of sodium hydroxide, potassium hydroxide, ammonia solution, triethylamine and triethanolamine.

The gist of the present invention is: use styrene, methacrylic acid, and hydroxypropyl acrylate as main raw materials, use chain transfer agent, initiator, and alkali as auxiliary raw materials, react at 60-90°C, then cool, and neutralize with alkali. and, the target dispersant solution is prepared; the solid content of the dispersant solution is 20-50%, and then the dispersant powder is obtained through spray drying.

Experiments show that the carboxylate terpolymer dispersant of the present invention has a good dispersion effect on inorganic powders such as calcium carbonate, zinc oxide, barium sulfate and titanium dioxide and pesticides; it is widely used in pesticide preparations, pigments, dyes and aqueous coal Pulp and other industries.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1. Methacrylic acid contains functionalized carboxylic acid groups, so the carboxylate terpolymer dispersant containing methacrylic acid units has good solubility in aqueous solution and good adaptability to the pH value of the dispersion system.

2. The carboxylate terpolymer dispersant of the present invention has an ideal degree of polymerization and carboxyl content, and stabilizes the dispersion of the dispersed substance through steric hindrance effect and electrostatic repulsion.

3. The carboxylate terpolymer dispersant has simple preparation process, easy operation, short production cycle, low cost, no environmental pollution, and is suitable for industrial scale production.

Detailed ways

The present invention will be described in further detail and completely below in conjunction with the examples, but these are only exemplary illustrations of the present invention, and are not intended to limit the scope of the present invention.

Example 1:

1) Preparation of dispersant:

Get 1000 parts of double distilled water, 10 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1 join in the four-necked reaction flask, heat while stirring; When the solution in the reaction flask When the temperature rises to 60°C, add 100 parts of styrene, 800 parts of methacrylic acid, 100 parts of hydroxypropyl acrylate and 30 parts of initiator solution within 1 hour, and then keep it at 60°C for 2 hours; Cool down to room temperature while stirring, neutralize the carboxylic acid in the system with sodium hydroxide solution, and the neutralization amount is 50% of the carboxyl molar number to obtain the target dispersant solution; this dispersant solution is according to the existing spray-drying method, The target dispersant powder is obtained.

Adopt gel permeation chromatography (GPC), take aqueous solution as mobile phase, sodium polyacrylate as standard substance, measure the number-average relative molecular weight of the prepared carboxylate terpolymer dispersant to be 15000.

2) Determination of the dispersibility of the prepared dispersant to inorganic minerals:

Add 0.4g of the dispersant prepared in step (1) and 50ml of distilled aqueous solution to a 100ml stoppered measuring cylinder, add 1.00g of solid particles to be dispersed after the dispersant is dissolved, then add the aqueous solution to 100ml, and turn it upside down 30 times within 1min , first upside down 180 °, and then return to the original position for 1 time. Place the graduated cylinder vertically in a super constant temperature aqueous solution bath at 25°C, keep it still without vibration, and avoid direct sunlight. After 30 minutes, use a straw to draw out 90ml of the upper suspension, and complete within 15s. Transfer the remaining 10ml suspension to a weighed dry Petri dish with a mass of _m1 , and rinse the graduated cylinder with distilled water to ensure that all the sediment in the graduated cylinder is transferred to the Petri dish, and put the Petri dish in an oven for 80 Dry at ℃, weigh m ₂ , calculate the mass M of insoluble matter, M=m ₂ -m ₁ , and calculate the suspension rate according to the following formula:

Wherein: M is the mass (g) of the dispersant and solid particles contained in the 10ml suspension at the bottom of the 100ml stoppered measuring cylinder, and 1.400 is the total mass (g) of the dispersant and solid particles contained in the 100ml stoppered measuring cylinder.

According to the above operation steps, it is measured that the suspension rate of the prepared dispersant to the barium sulfate suspension is 99.00%, and the suspension rate of the prepared dispersant to the titanium dioxide suspension is 95.15%.

3) described dispersant is measured to the dispersibility of pesticide:

Use the above-mentioned dispersant to prepare pesticide water-dispersible granules (WG), weigh 1.0g of this dry WG into a beaker, add 50ml of distilled aqueous solution, let it stand for 30s, stir it with a glass rod for 30s to disperse it evenly, and then use distilled aqueous solution to dissolve it. The suspension was transferred to a 100ml stoppered graduated cylinder, and distilled aqueous solution was added to 100ml. Cover the stopper and turn the stoppered cylinder upside down 30 times within 1 min. The graduated cylinder is turned upside down by 180° and then returned to the original position once. Place the graduated cylinder vertically in a 30°C super constant temperature aqueous solution bath, keep still without vibration, avoid direct sunlight, and after standing for 30 minutes, remove the upper 90ml suspension with a straw. Shake or stir up the sediment at the bottom of the graduated cylinder. Transfer the remaining 10ml suspension to a weighed Petri dish with a mass of _m1 , and rinse the graduated cylinder with distilled water to ensure that all the sediment at the bottom of the graduated cylinder is transferred to the Petri dish, and put the Petri dish in an oven at 80°C Dry, weigh m ₂ , calculate the mass of insoluble matter M=(m ₂ -m ₁ ), and then calculate the suspension rate according to the following formula:

Among them, 1.00 is the mass of the added water-dispersible granules; M is the mass of the sediment at the bottom of the stoppered measuring cylinder.

Example 2:

Take 1000 parts of double distilled water and 80 parts of chain transfer agent, the composition of chain transfer agent is 1: 1.2 sodium bisulfite and isopropanol aqueous solution; join in the four-necked reaction flask, heat while stirring; when the reaction flask When the temperature of the solution rises to 70°C, add 200 parts of styrene, 500 parts of methacrylic acid, 300 parts of hydroxypropyl acrylate and 60 parts of initiator solution within 5 hours, and then keep the temperature for 3 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 80% of the molar number of carboxyl groups, to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 2500.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 98.85%, and the suspension rate to the titanium dioxide suspension was 96.22%.

Example 3:

Take 1000 parts of double distilled water and 20 parts of chain transfer agent, the composition of chain transfer agent is 1:0.8 sodium bisulfite and isopropanol aqueous solution; join in the four-necked reaction flask, heat while stirring; when the reaction flask When the temperature of the solution rises to 80°C, add 200 parts of styrene, 600 parts of methacrylic acid, 200 parts of hydroxypropyl acrylate and 60 parts of initiator solution within 2 hours, and then keep warm for 5 hours. After the heat preservation reaction is completed, it is lowered to room temperature while stirring, and the carboxylic acid in the system is neutralized with sodium hydroxide solution, and the neutralization amount is 80% of the carboxyl moles, so as to obtain the target dispersant solution; the dispersant solution is spray-dried to obtain Target dispersant powder.

Gel permeation chromatography was used to measure the number-average relative molecular weight of the prepared carboxylate terpolymer dispersant to be 4500 with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 98.80%, and the suspension rate to the titanium dioxide suspension was 96.22%.

Example 4:

Get 1000 parts of double distilled water and 40 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1: 1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 70°C, add 100 parts of styrene, 700 parts of methacrylic acid, 200 parts of hydroxypropyl acrylate and 30 parts of initiator solution within 2 hours, and then keep the temperature for 3 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 80% of the molar number of carboxyl groups, to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

The number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 7200 by using gel permeation chromatography with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 97.82%, and the suspension rate to the titanium dioxide suspension was 96.55%.

Example 5:

Get 1000 parts of double distilled water and 40 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1: 1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 90°C, add 400 parts of styrene, 300 parts of methacrylic acid, 300 parts of hydroxypropyl acrylate and 40 parts of the initiator solution within 3 hours, and then keep the reaction for 4 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 60% of the molar number of carboxyl groups, to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Gel permeation chromatography was used to measure the number average relative molecular weight of the prepared carboxylate terpolymer dispersant to be 6500 with aqueous solution as mobile phase and sodium polyacrylate as standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 97.99%, and the suspension rate to the titanium dioxide suspension was 95.05%.

Embodiment 6:

Get 1000 parts of double distilled water and 80 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 80°C, add 400 parts of styrene, 200 parts of methacrylic acid, 400 parts of hydroxypropyl acrylate and 60 parts of initiator solution within 4 hours, and then keep the temperature for 5 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 90% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 2500.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 98.86%, and the suspension rate to the titanium dioxide suspension was 97.05%.

Embodiment 7:

Take 1000 parts of alcohol solution and 100 parts of chain transfer agent, the composition of chain transfer agent is 1:1 sodium bisulfite and isopropanol aqueous solution, join in the four-necked reaction flask, heat while stirring; when the solution in the reaction flask When the temperature rises to 70°C, add 200 parts of styrene, 200 parts of methacrylic acid, 600 parts of hydroxypropyl acrylate and 30 parts of initiator solution within 3 hours, and then keep the reaction for 1 hour; after the heat preservation reaction is completed, stir while Cool down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 90% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder.

The number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 5300 by means of gel permeation chromatography with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 96.60%, and the suspension rate to the titanium dioxide suspension was 93.35%.

Embodiment 8:

Get 1000 parts of alcohol solution and 60 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1, join in the four-necked reaction flask, heat while stirring; When the solution in the reaction flask When the temperature rises to 60°C, add 300 parts of styrene, 500 parts of methacrylic acid, 200 parts of hydroxypropyl acrylate and 160 parts of initiator solution within 3 hours, and then keep the reaction for 3 hours; after the heat preservation reaction is completed, stir while Cool down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 80% of the carboxyl moles, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder.

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was measured to be 1800.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 98.60%, and the suspension rate to the titanium dioxide suspension was 95.82%.

Embodiment 9:

Get 1000 parts of double distilled water and 80 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 80°C, add 400 parts of styrene, 500 parts of methacrylic acid, 100 parts of hydroxypropyl acrylate and 80 parts of initiator solution within 2 hours, and then keep the temperature for 3 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 70% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Gel permeation chromatography was used to measure the number-average relative molecular weight of the prepared carboxylate terpolymer dispersant to be 3300 with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 95.82%, and the suspension rate to the titanium dioxide suspension was 93.35%.

Example 10:

Take 1000 parts of double distilled water and 100 parts of chain transfer agent, the composition of chain transfer agent is 1:1 sodium bisulfite and isopropanol aqueous solution, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 90°C, add 100 parts of styrene, 700 parts of methacrylic acid, 200 parts of hydroxypropyl acrylate and 50 parts of initiator solution within 1 hour, and then keep the temperature for 4 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 70% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

The number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 5600 by using gel permeation chromatography with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 91.60%, and the suspension rate to the titanium dioxide suspension was 90.06%.

Example 11:

Take 1000 parts of double distilled water and 10 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 80°C, add 200 parts of styrene, 700 parts of methacrylic acid, 100 parts of hydroxypropyl acrylate and 20 parts of initiator solution within 1 hour, and then keep the temperature for 2 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 80% of the molar number of carboxyl groups, to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 19500.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 96.80%, and the suspension rate to the titanium dioxide suspension was 93.26%.

Example 12:

Get 1000 parts of double distilled water and 50 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1: 1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 60°C, add 300 parts of styrene, 600 parts of methacrylic acid, 100 parts of hydroxypropyl acrylate and 30 parts of the initiator solution within 2 hours, and then keep the reaction for 4 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, and the neutralization amount is 100% of the carboxyl moles to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Gel permeation chromatography was adopted, with aqueous solution as mobile phase and sodium polyacrylate as standard, and the number-average relative molecular weight of the prepared carboxylate terpolymer dispersant was measured to be 15,000.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 90.00%, and the suspension rate to the titanium dioxide suspension was 95.24%.

Example 13:

Get 1000 parts of double distilled water and 50 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1: 1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 70°C, add 400 parts of styrene, 500 parts of methacrylic acid, 100 parts of hydroxypropyl acrylate and 100 parts of the initiator solution within 4 hours, and then keep the reaction for 4 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 90% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Gel permeation chromatography was used to measure the number average relative molecular weight of the prepared carboxylate terpolymer dispersant to be 4200 with aqueous solution as mobile phase and sodium polyacrylate as standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 93.00%, and the suspension rate to the titanium dioxide suspension was 94.07%.

Example 14:

Get 1000 parts of double distilled water and 50 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1: 1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 60°C, add 400 parts of styrene, 200 parts of methacrylic acid, 400 parts of hydroxypropyl acrylate and 120 parts of initiator solution within 4 hours, and then keep the reaction for 3 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 70% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Gel permeation chromatography was used to measure the number-average relative molecular weight of the prepared carboxylate terpolymer dispersant to be 4000 with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 97.80%, and the suspension rate to the titanium dioxide suspension was 96.56%.

Example 15:

Get 1000 parts of double distilled water and 30 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1: 1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 60°C, add 400 parts of styrene, 100 parts of methacrylic acid, 500 parts of hydroxypropyl acrylate and 60 parts of initiator solution within 2 hours, and then keep the temperature for 5 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 60% of the molar number of carboxyl groups, to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

The number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 6700 by using gel permeation chromatography with aqueous solution as the mobile phase and sodium polyacrylate as the standard.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 92.84%, and the suspension rate to the titanium dioxide suspension was 93.28%.

Example 16:

Get 1000 parts of double distilled water and 80 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 80°C, add 400 parts of styrene, 300 parts of methacrylic acid, 300 parts of hydroxypropyl acrylate and 10 parts of initiator solution within 1 hour, and then keep the temperature for 2 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, and the neutralization amount is 50% of the carboxyl moles to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was measured to be 18800.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 92.85%, and the suspension rate to the titanium dioxide suspension was 93.29%.

Example 17:

Take 1000 parts of double distilled water and 100 parts of chain transfer agent, the composition of chain transfer agent is 1:1 sodium bisulfite and isopropanol aqueous solution, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 90°C, add 200 parts of styrene, 200 parts of methacrylic acid, 600 parts of hydroxypropyl acrylate and 20 parts of initiator solution within 3 hours, and then keep the temperature for 3 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 70% of the molar number of carboxyl groups, and obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was determined to be 16500.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 90.81%, and the suspension rate to the titanium dioxide suspension was 89.82%.

Example 18:

Get 1000 parts of double distilled water and 80 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:1, join in the four-necked reaction flask, heat while stirring; When the temperature of the solution rises to 70°C, add 100 parts of styrene, 300 parts of methacrylic acid, 600 parts of hydroxypropyl acrylate and 80 parts of initiator solution within 2 hours, and then keep the reaction for 2 hours; stir after the heat preservation reaction is completed While cooling down to room temperature, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 80% of the molar number of carboxyl groups, to obtain the target dispersant solution; spray dry the dispersant solution to obtain the target dispersant powder .

Using gel permeation chromatography, using aqueous solution as mobile phase and sodium polyacrylate as standard, the number average relative molecular weight of the prepared carboxylate terpolymer dispersant was measured to be 5500.

According to the operation steps described in Example 1, the suspension rate of the above-mentioned dispersant to the barium sulfate suspension was measured to be 98.85%, and the suspension rate to the titanium dioxide suspension was 97.28%.

The above-mentioned embodiments are only preferred examples of the present invention, and are not intended to limit the present invention. Any modifications and changes made within the principles of the present invention are within the protection scope of the present invention.

Claims (3)

1. a carboxylate terpolymer dispersing agent, is made up of than material following quality:

10～50 parts of styrene

10～80 parts of methacrylic acids

10～50 parts of hydroxypropyl acrylates;

The equal relative molecular weight of number of terpolymer is 1000～20000;

Its preparation technology's step is as follows:

A) in reaction bulb, add the aqueous solution of distilled water and chain-transferring agent, stir, be heated to 60～90 ℃;

B) in above-mentioned solution, drip styrene, methacrylic acid, hydroxypropyl acrylate and initiator solution, in 1～5 hour, dropwise insulation reaction 2～10 hours;

C) step b gained solution is stirred, is cooled to room temperature, with the carboxylic acid in alkali and in system, dosis neutralisata is 50～100% of carboxyl molal quantity; Described alkali is one or both in NaOH, potassium hydroxide, ammonia spirit, triethylamine, triethanolamine;

D) the dry target dispersant powder that makes of metal carboxylate terpolymer solution spray of being prepared by step c.

2. carboxylate terpolymer dispersing agent according to claim 1, is characterized in that: described chain-transferring agent is sodium hydrogensulfite and isopropyl alcohol, and consumption is 0.5～10% of monomer gross mass.

3. carboxylate terpolymer dispersing agent according to claim 1, is characterized in that: described initator is ammonium persulfate, and consumption is 2～16% of monomer gross mass.