阅读说明：本技术 一种水性润湿分散剂的制备方法、水性润湿分散剂与应用 (Preparation method of aqueous wetting dispersant, aqueous wetting dispersant and application ) 是由 王宇 来伟伟 朱广东 陈占 魏亚娜 于 2019-11-26 设计创作，主要内容包括：本发明公开了一种水性润湿分散剂的制备方法,包括：(1)、配方量的丙烯酸单体、含酰胺基的环状化合物、不饱和阴离子烯基磺酸盐化合物在引发剂和链转移剂的作用下通过自由基聚合反应制备得到聚合物,真空干燥得到固体聚合物；(2)、用适量的水溶解固体聚合物,调节pH至6～8,得到水性润湿分散剂。还公开了上述方法制备的水性润湿分散剂,水性润湿分散剂制备色浆的应用。本发明的水性润湿分散剂制备的到的色浆的粒径小,稳定性好且相容性好,同时炭黑的添加量大。(The invention discloses a preparation method of a water-based wetting dispersant, which comprises the following steps: (1) the acrylic monomer, the cyclic compound containing the amido group and the unsaturated anionic alkenyl sulfonate compound in the formula amount are subjected to free radical polymerization reaction under the action of an initiator and a chain transfer agent to prepare a polymer, and the polymer is dried in vacuum to obtain a solid polymer; (2) and dissolving the solid polymer by using a proper amount of water, and adjusting the pH value to 6-8 to obtain the water-based wetting dispersant. Also discloses the aqueous wetting dispersant prepared by the method and application of the aqueous wetting dispersant in preparing color paste. The color paste prepared by the water-based wetting dispersant has small particle size, good stability and compatibility, and large addition amount of carbon black.)

1. The preparation method of the aqueous wetting dispersant is characterized by comprising the following preparation steps:

(1) under the action of an initiator and a chain transfer agent, the acrylic monomer, the cyclic compound containing the amido group and the unsaturated anionic alkenyl sulfonate compound in the formula amount are subjected to free radical polymerization reaction in a water-containing polymerization system to prepare a viscous polymer, and the viscous polymer is dried in vacuum to obtain a solid polymer;

(2) dissolving the solid polymer obtained in the step (1) with a proper amount of water, and adjusting the pH value to 6-8 to obtain a water-based wetting dispersant;

in the step (1), the acrylic monomer, the cyclic compound containing an amide group and the unsaturated anionic alkenyl sulfonate compound are, by mass, based on 100% of the total mass of the monomers: 40 to 50 percent of acrylic monomer; 20 to 30 percent of cyclic compound containing amido; 30-40% of unsaturated anion alkenyl sulfonate compound;

the amount of the initiator is 0.1-0.8% of the mass of the acrylic monomer, and the amount of the chain transfer agent is 0.25-2.5% of the mass of the acrylic monomer;

the total mass of the monomers accounts for 29.9-50% of the total mass of the polymerization system.

2. The method for preparing an aqueous wetting dispersant according to claim 1, wherein the molecular weight of said solid polymer in said step (1) is 8000 to 20000.

3. The method of preparing the aqueous wetting dispersant according to claim 1, characterized in that the initiator is selected from the group consisting of: one or more of benzoyl peroxide, cumene hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxybenzoate, azobisisobutyronitrile and azobisisoheptonitrile;

the chain transfer agent is selected from: one or more of isopropanol, sodium bisulfite, mercaptoethanol, thioglycolic acid, mercaptopropionic acid and sodium dihydrogen phosphate.

4. The method of preparing the aqueous wetting dispersant according to claim 1, characterized in that the acrylic monomer is selected from the group consisting of: one or more of acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, tert-butyl acrylate, n-octyl acrylate, 2-ethoxyethyl acrylate, cyclohexyl acrylate, hexyl methacrylate, isooctyl methacrylate, decyl methacrylate, isobornyl acrylate, lauryl methacrylate, tetrahydrofuryl acrylate, methoxypolyethylene glycol monoester acrylate, octadecyl acrylate, alkoxylated phenol acrylate, trimethylolpropane formal acrylate;

the cyclic compound containing an amide group is selected from: n-vinylpyrrolidone, 1- (allyl) pyrrolidin-2-one, 2-vinylbenzamide, N-allyl-2-aminobenzamide, N-1-methyleneallyl-benzamide, 2-hydroxy-N- (2-hydroxyethyl) -3-methoxy-5- (2-propenyl) benzamide, one or more of N-vinyl caprolactam, N-vinyl valerolactam, N-vinyl lauryllactam, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-4-methyl-2-pyrrolidone and N-vinyl-5-methyl-2-pyrrolidone;

the unsaturated anionic alkenyl sulfonate compound is selected from the group consisting of: one or more of sodium allyl sulfonate, sodium methallyl sulfonate, sodium hydroxypropyl methacrylate, sodium 2-acrylamide-2-methylpropanesulfonate, sodium styrene sulfonate, sodium p-styrene sulfonate, sodium vinyl sulfonate, sodium methacrylamide-2-methylpropanesulfonate, sodium 2-acrylamide-n-butyl sulfonate and sodium 2-acrylamide dodecyl sulfonate.

5. The method for preparing the aqueous wetting dispersant according to claim 1, characterized in that the step (1) specifically comprises the following substeps:

a) firstly, adding a proper amount of water into the reaction container to dissolve the initiator and the chain transfer agent in the formula amount, then adding the acrylic monomer in the formula amount, stirring and reacting for 1-3 h, heating to 60-90 ℃, and carrying out heat preservation reaction for 2-4 h to obtain an acrylate polymer;

b) and b), sequentially dropwise adding the cyclic compound containing the amide group and the unsaturated anionic alkenyl sulfonate compound with the formula amount into the acrylate polymer prepared in the step a), heating while dropwise adding, controlling the dropwise adding time to be 1.5-2.5 h, controlling the final temperature to be 90-110 ℃, continuing stirring and reacting for 1-3 h after dropwise adding is finished, stopping stirring, performing heat preservation and reacting for 2-4 h to obtain a viscous polymer, taking out the polymer, and performing vacuum drying to obtain the solid polymer.

6. The method for preparing an aqueous wetting dispersant according to claim 1, wherein in the step (2), the solid polymer is dissolved with water at a solid content of 40 to 60% to obtain the aqueous wetting dispersant.

7. An aqueous wetting dispersant prepared by the method for preparing an aqueous wetting dispersant according to any one of claims 1 to 6.

8. Use of the aqueous wetting dispersant according to claim 7 for the preparation of mill bases for dispersing pigments.

9. Use of the aqueous wetting dispersant according to claim 8 for the preparation of carbon black paste for dispersing carbon black pigments.

10. The carbon black color paste is characterized by comprising the following components in percentage by mass:

5 wt% -15 wt% of water-based wetting dispersant:

40-60 wt% of carbon black pigment;

the balance of water;

the aqueous wetting dispersant is the aqueous wetting dispersant according to claim 7.

Technical Field

The invention belongs to the technical field of color paste dispersing agents, and particularly relates to a water-based wetting dispersing agent, and a preparation method and application thereof.

Background

With the rapid development of industries such as coating and ink in China, the market demand of the auxiliary agent for the water-based coating or the water-based ink is increased. It is well known that when an aqueous coating or ink is formulated for application, an aqueous wetting dispersant must be added to allow the pigment to be uniformly and stably dispersed, which is important for the later storage stability of the coating or other applications. Therefore, the market demand of the aqueous wetting dispersant is large, but the aqueous wetting dispersant in the current market has various varieties, and although each has advantages and disadvantages, the aqueous wetting dispersant cannot ensure that most organic pigments are well dispersed, and the dispersed color paste generally has the disadvantages of large viscosity, poor compatibility, poor stability and low organic pigment addition amount, so that the application range of the color paste is extremely narrow and the color paste cannot be well popularized.

Carbon black is one of inorganic pigments, and has a wide range of applications. In the prior art, the stability of the carbon black color paste is basically guaranteed on the basis of an anchoring group, steric hindrance and a solvation chain, and the carbon black color paste dispersed by the three methods is easy to generate color paste aggregation and secondary thickening phenomena along with the prolonging of time, and the carbon black is re-flocculated to become aggregates, so that the color paste has poor stability and cannot be stored for a long time.

CN102049214A discloses a dispersing agent and color paste prepared by the same, wherein a dispersing agent prepared from block polyether L61/L64/F68 is used for dispersing carbon black pigment, and the dispersed carbon black color paste is applied to coloring of viscose fiber stock solution, so that the problems of discontinuous production and much foam are solved.

CN105368160A discloses an aqueous carbon black color paste dispersing agent and application thereof in preparation of carbon black color paste, wherein green and environment-friendly sodium carboxymethyl hemicellulose is adopted as the dispersing agent, but the addition amount of carbon black is lower and is 10-25% when the paste is ground, and the particle size of the color paste is about 200nm, the particle size is still larger, which is very unfavorable for the storage stability of the color paste. However, as known to those skilled in the art, the pigment addition amount in the color paste is high, so that the cost is relatively low, and when the color paste is applied to the field of subsequent emulsion, the addition proportion can be relatively reduced, so that the influence on an application system is less, and meanwhile, the formula of the subsequent application system has a larger adjustment space.

In summary, in the prior art, the carbon black color paste has large particle size, poor stability and compatibility, and small addition amount of carbon black, which directly affects subsequent industrial applications, so it is necessary to develop a novel aqueous wetting dispersant to overcome the above technical problems in the prior art.

Disclosure of Invention

A first aspect of the present invention is to provide a method for preparing an aqueous wetting dispersant to overcome the above technical problems in the prior art.

In order to realize the purpose, the following technical scheme is adopted:

a preparation method of the aqueous wetting dispersant comprises the following preparation steps:

(1) under the action of an initiator and a chain transfer agent, the acrylic monomer, the cyclic compound containing the amido group and the unsaturated anionic alkenyl sulfonate compound in the formula amount are subjected to free radical polymerization reaction in a water-containing polymerization system to prepare a viscous polymer, and the viscous polymer is dried in vacuum to obtain a solid polymer;

(2) dissolving the solid polymer obtained in the step (1) with a proper amount of water, and adjusting the pH value to 6-8 to obtain a water-based wetting dispersant;

in the step (1), the acrylic monomer, the cyclic compound containing an amide group and the unsaturated anionic alkenyl sulfonate compound are, by mass, based on 100% of the total mass of the monomers: 40 to 50 percent of acrylic monomer; 20 to 30 percent of cyclic compound containing amido; 30-40% of unsaturated anion alkenyl sulfonate compound;

the dosage of the initiator is 0.1-0.8% of the mass of the acrylic monomer, and the dosage of the chain transfer agent is 0.25-2.5% of the mass of the acrylic monomer.

The total mass of the monomers accounts for 29.9-50% of the total mass of the polymerization system.

The water-soluble wetting dispersant prepared by the technical scheme can be used for dispersing carbon black pigment, and the prepared carbon black color paste has small particle size, good stability and good compatibility with resin.

Through detection, the molecular weight of the solid polymer prepared by the technical scheme is 8000-20000.

It is well known to those skilled in the art that carbon black, as one of inorganic pigments, is a pigment that is more difficult to disperse. Therefore, the water-soluble wetting dispersant prepared by the technical scheme can be equally applied to the dispersion of other inorganic or organic pigments to prepare pigment paste as is easily understood by a person skilled in the art.

As will be readily understood by those skilled in the art, the initiator is a water soluble initiator and the chain transfer agent is a water soluble chain transfer agent.

According to the invention, the initiator is selected from: one or more of benzoyl peroxide, cumene hydroperoxide, di-tert-butyl peroxide, tert-butyl peroxybenzoate, azobisisobutyronitrile and azobisisoheptonitrile;

the chain transfer agent is selected from: one or more of isopropanol, sodium bisulfite, mercaptoethanol, thioglycolic acid, mercaptopropionic acid and sodium dihydrogen phosphate.

It will be readily understood by those skilled in the art that the acrylic monomer may be one commonly used in the coating and ink art. Preferably, the acrylic monomer is selected from: one or more of acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, tert-butyl acrylate, n-octyl acrylate, 2-ethoxyethyl acrylate, cyclohexyl acrylate, hexyl methacrylate, isooctyl methacrylate, decyl methacrylate, isobornyl acrylate, lauryl methacrylate, tetrahydrofuryl acrylate, methoxypolyethylene glycol monoester acrylate, octadecyl acrylate, alkoxylated phenol acrylate, and trimethylolpropane formal acrylate.

Preferably, the cyclic compound containing an amide group is selected from: n-vinylpyrrolidone, 1- (allyl) pyrrolidin-2-one, 2-vinylbenzamide, N-allyl-2-aminobenzamide, N-1-methyleneallyl-benzamide, 2-hydroxy-N- (2-hydroxyethyl) -3-methoxy-5- (2-propenyl) benzamide, one or more of N-vinyl caprolactam, N-vinyl valerolactam, N-vinyl lauryllactam, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-4-methyl-2-pyrrolidone and N-vinyl-5-methyl-2-pyrrolidone.

Preferably, the unsaturated anionic alkenyl sulfonate compound is selected from: one or more of sodium allyl sulfonate, sodium methallyl sulfonate, sodium hydroxypropyl methacrylate, sodium 2-acrylamide-2-methylpropanesulfonate, sodium styrene sulfonate, sodium p-styrene sulfonate, sodium vinyl sulfonate, sodium methacrylamide-2-methylpropanesulfonate, sodium 2-acrylamide-n-butyl sulfonate and sodium 2-acrylamide dodecyl sulfonate.

According to a preferred technical scheme of the invention, the step (1) specifically comprises the following sub-steps:

a) firstly, adding a proper amount of water into the reaction container to dissolve the initiator and the chain transfer agent in the formula amount, then adding the acrylic monomer in the formula amount, stirring and reacting for 1-3 h, heating to 60-90 ℃, and carrying out heat preservation reaction for 2-4 h to obtain an acrylate polymer;

b) and b), sequentially dropwise adding the cyclic compound containing the amide group and the unsaturated anionic alkenyl sulfonate compound with the formula amount into the acrylate polymer prepared in the step a), heating while dropwise adding, controlling the dropwise adding time to be 1.5-2.5 h, controlling the final temperature to be 90-110 ℃, continuing stirring and reacting for 1-3 h after dropwise adding is finished, stopping stirring, performing heat preservation and reacting for 2-4 h to obtain a viscous polymer, taking out the polymer, and performing vacuum drying to obtain the solid polymer.

Under the preferable technical conditions, when the prepared water-based wetting dispersant is used for dispersing pigment to prepare color paste, the particle size of the color paste is smaller, and the stability and the subsequent compatibility are better.

According to the invention, in the step (2), the solid polymer in the step (1) is dissolved by deionized water according to the solid content of 40-60% to obtain the aqueous wetting dispersant.

Preferably, in the step (2), the solid polymer in the step (1) is dissolved with water according to a solid content of 45-50% to obtain the aqueous wetting dispersant.

Preferably, the water is deionized water.

According to the invention, in the step (1), the amount of the water is 50 to 70% by mass of the total mass of the polymerization system.

More preferably, in the step (1), the total mass of the monomers is 29.9 to 49.8 percent of the total mass of the polymerization system; the amount of the water is 49.8-69.7% of the total mass of the polymerization system.

The second object of the present invention is to provide an aqueous wetting dispersant prepared by the above method for preparing an aqueous wetting dispersant.

The amount of water used to dissolve the solid polymer can be adjusted as needed to obtain aqueous wetting dispersants of different solids content. The solids content of the aqueous wetting dispersant may generally be in the range of 40% to 60% by weight. Within the above solid content range, an aqueous wetting dispersant having good stability can be obtained.

Preferably, the solid content of the aqueous wetting dispersant is 45 wt% to 50 wt%.

The third purpose of the invention is to provide the application of the aqueous wetting dispersant for preparing color paste by dispersing pigment.

Preferably, the above-described aqueous wetting dispersant is used to disperse carbon black pigment to prepare a carbon black paste.

According to the invention, in the carbon black color paste, the addition amount of the carbon black is 40-60 wt%. The addition range is larger than that of the conventional carbon black color paste.

Preferably, in the carbon black color paste, the addition amount of the carbon black is 45 wt% -60 wt%.

According to the invention, the particle size of the carbon black color paste is 20 nm-100 nm. Preferably, the particle size is 21nm to 76 nm.

The fourth purpose of the invention is to provide a carbon black color paste, which comprises the following components in percentage by mass:

5 wt% -15 wt% of water-based wetting dispersant:

40-60 wt% of carbon black pigment;

the balance of water;

the aqueous wetting dispersant is the aqueous wetting dispersant.

Preferably, the carbon black color paste comprises the following components in percentage by mass:

5 wt% -15 wt% of water-based wetting dispersant:

45-60 wt% of carbon black pigment;

the balance of water;

the aqueous wetting dispersant is the aqueous wetting dispersant.

Compared with the prior art, the invention has the following beneficial technical effects:

(1) the water-based wetting dispersant with a comb-shaped structure is prepared by free radical polymerization. The main component of the aqueous dispersant is an anionic polymer of modified acrylate, anions and cations contained in a sulfonic group on a side chain of the polymer can generate a large amount of positive and negative charges through ionization in an aqueous solution, the anions are connected to the side chain of the polymer, a large amount of negative charges are arranged on the surface of the polymer, and a certain electric potential is generated by the positive charges carried by free cations; due to the multi-electron conjugation between the amide group on the branched chain in the polymer and the adjacent group, the potential of the dispersant is further expanded on the basis of the potential generated by anions and cations, and the dispersant provided by the invention has strong potential through the two aspects of functions. Meanwhile, part of functional groups in the aqueous wetting dispersant of the invention improve the stability of the carbon black color paste by the assistance of steric hindrance.

In the grinding process of the carbon black color paste, the group of the substance on the inner branched chain of the water-based wetting dispersant can generate larger potential due to the action of charges between positive and negative, under the action of high potential, the carbon black easily aggregates are firstly separated, after the carbon black particles are separated by dissociation and dispersion, the dispersant can directly wet the carbon black particles after contacting with the carbon black particles and then anchor and combine the carbon black particles, the carbon black particles after anchoring are not only acted by the van der Waals force of the dispersant, but also generate strong electrokinetic potential due to mutual repulsion between the same charges, and the high electrokinetic potential ensures that the color paste has high stability. By the dispersion mechanism of firstly dissociating the carbon black aggregate and then combining the carbon black particles, the stability of the color paste formed by the carbon black pigment after dispersion is obviously improved compared with the existing carbon black color paste.

Therefore, compared with other water-based wetting dispersants, the water-based wetting dispersant provided by the invention can be used for dispersing carbon black particles in the above modes, so that the stability of the obtained carbon black color paste is remarkably improved, and the particle size of the carbon black color paste is greatly reduced. And the addition amount of the carbon black is more and accounts for about 45 to 60 weight percent of the carbon black color paste.

(2) In addition, the water-based wetting dispersant disclosed by the invention has a good wetting effect, not only can act as a wetting agent when the carbon black particles are dissociated and dispersed, but also can show good wetting property in the application of the color paste, and the prepared carbon black color paste can strongly reduce the surface tension when matched with other substances, so that the adhesive force with other substances is remarkably increased. After the hydrophilic group of the water-based wetting dispersant is contacted with other substances (such as three types of emulsions), the surface tension of the other substances is reduced, so that the color paste can be well dissolved with the other substances, and the excellent compatibility of the carbon black color paste is shown, thereby ensuring that the carbon black color paste obtained by dispersing the water-based wetting dispersant has wider application. Meanwhile, the fluidity and the color spreading effect of the carbon black color paste are good.

(3) The process of the aqueous wetting dispersant is not complex, the production efficiency is high, and the obtained aqueous wetting dispersant does not contain VOC and is healthy and environment-friendly.

Detailed Description

The present invention will be further described with reference to the following examples. It should be understood that the following examples are illustrative only and are not intended to limit the scope of the present invention.

In the following examples:

styrene acrylic emulsion, purchased from Dow chemical company, model AS-2010A.

Acrylate emulsion, purchased from BASF corporation, model Acronal 7016G.

Butylbenzene emulsion, available from BASF corporation, model SD-623.

An outsourcing carbon black paste, model BK9007, from Guangdong.

The other raw materials are all sold in the market.