CN106582436B - A kind of terpolymer dispersant and its preparation process - Google Patents

Abstract

The present invention relates to a kind of copolymer dispersant, carboxylate terpolymer dispersing agent and its preparation process.The present invention is by following mass ratio material composition: 10~20 parts of styrene, itaconic acid and its 30~50 parts of derivative, 20~30 parts of hydroxyethyl methacrylate.The invention has the advantages that the carboxylate terpolymer dispersing agent simultaneously containing itaconic acid and hydroxyethyl methacrylate unit has preferable water solubility, there is good adaptability to the pH value of dispersion；Dispersing agent has the ideal degree of polymerization and carboxyl, is made by space steric effect and electrostatic repulsion by dispersed substance stably dispersing, system viscosity is low；Preparation process is simple, operation is easy, with short production cycle, low in cost, non-environmental-pollution, is suitable for industrial scale production.

Description

A kind of terpolymer dispersant and its preparation process

technical field

The invention belongs to the synthesis technology of a novel 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 inventor's research group has done a lot of work on polymer molecular weight control before, such as Chinese patent ZL200810201806.1 (styrene-sodium styrene sulfonate-hydroxypropyl acrylate terpolymer dispersant), CN201110055926. 7 (methacrylic acid-styrene-hydroxypropyl acrylate terpolymer dispersant), CN201110440872.6 (methacrylic acid-styrene binary copolymer dispersant), CN201110440854.8 (methacrylic acid-styrene- Maleic anhydride terpolymer dispersant), "Synthesis and Dispersion Properties of Acrylic Copolymer Dispersant" published in Process Engineering Journal. In addition, methods for controlling the molecular weight of polymers in this technical field include: using mercapto compounds as chain transfer agents to control polymer molecular weights, patent literature: EP1304314; using metal salts as molecular weight regulators, patent literature: CN1085570; Polymerization in a water-isopropanol mixed solvent achieves the purpose of controlling the molecular weight of the polymer, patent 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.

Existing technology has drawbacks:

The application of carboxylate copolymer dispersants is becoming more and more extensive, but the synthesis process of this kind of dispersants still has difficult technical problems such as difficult to control the molecular weight, high viscosity of the system, and unsatisfactory dispersion effect. Therefore, it is very important to invent a carboxylate terpolymer dispersant with excellent dispersibility, low preparation cost and environment-friendly and its preparation process.

Contents of the invention

The object of the present invention is to invent a carboxylate terpolymer dispersant with easy controllable molecular weight, low system viscosity, excellent dispersibility, low preparation cost and environmental friendliness and its preparation process.

The ratio of the monomers used is as follows:

Styrene 10-20 parts

Itaconic acid and its derivatives 30-50 parts

20-30 parts of hydroxyethyl methacrylate

The itaconic acid and its derivatives include itaconic acid and its esters.

The synthetic route of described carboxylate terpolymer dispersant is as follows:

The purpose of the present invention is achieved in that the steps are as follows:

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

b) Add styrene, itaconic acid and its derivatives, hydroxyethyl methacrylate and initiator solution dropwise to the above solution, complete the dropwise addition within 1 to 5 hours, and keep warm for 2 to 10 hours;

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

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 one of ammonium persulfate, potassium persulfate and hydrogen peroxide, and the dosage is 2-16% of the total mass of monomers.

The alkali is one or two of sodium hydroxide, potassium hydroxide, ammonia solution, triethylamine and triethanolamine, and the neutralization amount is 50-100% of the carboxyl moles.

The gist of the present invention is: take styrene, itaconic acid and hydroxyethyl methacrylate as main raw materials, use chain transfer agent, initiator, alkali as auxiliary raw materials, react under the condition of 60～90 ℃, then cool, use Alkali neutralization to obtain the target dispersant solution; the solid content of the dispersant solution is 20-50%.

The application technical effect of the present invention: the carboxylate terpolymer dispersant of the present invention has good dispersion effect to inorganic powders such as calcium carbonate, zinc oxide; % Atrazine SC, 5% fipronil SC, 480g/L imidacloprid SC have good dispersing properties; in addition, they can also be used in dispersing pigments, dyes, coal water slurry, etc., and also have good dispersing effects.

Compared with prior art, beneficial effect and innovation of the present invention are as follows:

1. The carboxylate terpolymer dispersant of the present invention has a novel structure and belongs to a new type of dispersant.

2. Acrylic acid homologues contain functionalized carboxylic acid groups, and itaconic acid also provides carboxylate groups, so the carboxylate terpolymer dispersant of the present invention has good water solubility, and the pH value of the dispersion system Have good adaptability.

3. The carboxylate terpolymer dispersant of the present invention has an ideal degree of polymerization and functional groups of carboxyl and sulfonate groups, and can stabilize the dispersed material through steric hindrance effect and electrostatic repulsion.

The present invention has prominent substantive technical features and significant technological progress; therefore, the present invention is inventive.

After extensively consulting public publications and patent documents at home and abroad, there is no technical data completely identical to the technical solution of the present invention, and the present invention has novelty. The invention has wide application in the field of pesticide dosage form, and the invention has practicability.

The invention has the advantages of simple preparation process, easy operation, short production period, low cost, no environmental pollution and suitable for industrial scale production.

Detailed ways

Below in conjunction with embodiment, the present invention is described in further detail and completely:

Example 1:

1) Preparation of dispersant:

Add 1000 parts of double distilled water, 10 parts of chain transfer agent, and the composition of the chain transfer agent is 1:1 sodium bisulfite and isopropanol aqueous solution into a four-necked reaction flask, and heat while stirring; when the solution in the reaction flask When the temperature rises to 60°C, add 200 parts of styrene, 500 parts of itaconic acid, 250 parts of hydroxyethyl methacrylate and 30 parts of initiator solution within 3 hours, and then keep it at 60°C for 2 hours; After finishing, drop 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 mole number, so that the target dispersant solution is obtained.

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

Add 0.4 g of the dispersant prepared in step (1) and 50 ml of distilled aqueous solution to a 100 ml stoppered measuring cylinder, add 1.00 g of solid particles to be dispersed after the dispersant is dissolved, then add the aqueous solution to 100 ml, within 1 min Upside down 30 times, first upside down 180 °, and then return to the original position for 1 time. Place the graduated cylinder vertically in a constant temperature water bath at 25°C, keep it still without vibration, and avoid direct sunlight. At 30 minutes, use a straw to draw out 90 ml of the upper suspension, and complete within 15 seconds. Transfer the remaining 10 ml 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 into the oven Dry at 80°C, weigh m ₂ , and calculate the mass M of insoluble matter,

M = m ₂ - m ₁ , calculate the suspension rate according to the following formula:

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

According to the above operation steps, the suspension rate of the prepared dispersant to the calcium carbonate suspension is 98.50%, and the suspension rate of the prepared dispersant to the aluminum oxide suspension is 98.08%.

3) Determination of the dispersibility of the dispersant to pesticides:

Use the above dispersant to prepare pesticide water suspension (SC), weigh 1.0 g of this pesticide SC into a beaker, add 50 ml of distilled aqueous solution, let it stand for 30 s, stir with a glass rod for 30 s to disperse it evenly, and then dissolve it with distilled aqueous solution Transfer this suspension to a 100 ml stoppered measuring cylinder, add distilled aqueous solution to 100 ml. Cover the stopper, turn the stoppered measuring cylinder upside down 30 times within 1 min, and turn the measuring cylinder upside down 180° and then return to the original position once. Place the graduated cylinder vertically in a super constant temperature aqueous solution bath at 30 °C, keep still without vibration, avoid direct sunlight, and after standing still for 30 min, remove the upper 90 ml suspension with a straw. This process makes the tip of the tube a few millimeters below the liquid surface, Make sure not to shake or stir up the sediment at the bottom of the graduated cylinder. Transfer the remaining 10 ml 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 for 80 Dry at ℃, 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, 1.0 is the mass of the added water suspension concentrate (SC); the effective content is the percentage of pesticide in SC; M is the mass of the sediment at the bottom of the stoppered measuring cylinder.

According to the above operation steps, the suspension ratio of the above-mentioned dispersant to the 43% tebuconazole aqueous suspension concentrate is 96.04%.

Example 2:

Add 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 1:1.2 into a four-necked reaction flask, and heat while stirring; when the solution in the reaction flask When the temperature rises to 70°C, add 200 parts of styrene, 300 parts of itaconic acid, 400 parts of hydroxyethyl methacrylate and 60 parts of initiator solution within 5 hours, and then keep the reaction for 3 hours; Cool down to room temperature while stirring, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 75% of the carboxyl moles, and obtain the target dispersant solution.

By the operation step described in embodiment 1, record above-mentioned dispersant to the suspending rate of calcium carbonate suspension 96.24%, to the suspending rate of aluminum oxide suspension 96.49%, to 43% tebuconazole aqueous suspending agent The suspension rate was 97.12%.

Example 3:

Add 1000 parts of double distilled water and 20 parts of chain transfer agent, the composition of chain transfer agent is sodium bisulfite and isopropanol aqueous solution of 1:0.8 into a four-necked reaction flask, and heat while stirring; when the solution in the reaction flask When the temperature rises to 80°C, add 200 parts of styrene, 250 parts of hydroxyethyl methacrylate, 450 parts of methacrylic acid and 60 parts of initiator solution within 2 hours, and then keep the reaction for 5 hours; Cool down to room temperature while stirring, neutralize the carboxylic acid in the system with sodium hydroxide solution, the neutralization amount is 85% of the carboxyl moles, and obtain the target dispersant solution.

By the operation procedure described in embodiment 1, record above-mentioned dispersant to the suspension rate of calcium carbonate suspension 97.37%, to the suspension rate of aluminum oxide suspension 97.22%, to the suspension rate of 43% tebuconazole suspension. The suspension rate was 96.04%.

The above descriptions 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 modifications and variations. All modifications, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (1)

1. a kind of carboxylate terpolymer dispersing agent, by following mass ratio material composition:

10~20 parts of styrene

Itaconic acid and its 30~50 parts of derivative

20~30 parts of hydroxyethyl methacrylate.