CN111040181A

CN111040181A - Polyacrylate dispersant and preparation method thereof

Info

Publication number: CN111040181A
Application number: CN201911364471.XA
Authority: CN
Inventors: 王金; 赖观品; 孙胜利
Original assignee: Bobang New Material Technology Guangzhou Co Ltd
Current assignee: Bobang New Material Technology Guangzhou Co Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-04-21

Abstract

The present invention relates to an addition compound, a process for the preparation of the addition compound and the use of the addition compound as a wetting dispersant in coating inks. The addition compound is a branched polyacrylate polymer prepared from polyacrylate with a specific structure through transesterification. The branched polyacrylate polymer dispersing aid has a structure represented by the following formula (I). The branched polymer of the invention is prepared by introducing branched polyether component into polyacrylate polymer through ester exchange reaction to improve the wetting ability to solid particles, and simultaneously, amino residue introduced through ester exchange reaction is bonded and anchored to the surface of the solid particlesWhen used, can provide excellent overall dispersion properties to the resulting dispersion.

Description

Polyacrylate dispersant and preparation method thereof

Technical Field

The present invention relates to a branched polymer prepared from a polyacrylate polymer by transesterification, which branched polymer is useful as a wetting and dispersing agent for pigments and fillers. The invention also relates to a method for producing said substances.

Background

The method is widely applied to solid particles as coloring or filling materials in the industries of coatings, adhesives, printing ink, paint, pigments and the like. Particulate solids used as pigments or fillers generally have a relatively small particle size, for example, in the micrometer or even nanometer range. If the incorporation of solid particles in the coating ink system is not optimal, flocculation, loss of gloss, color change, settling, and poor flow properties can result. Uniform incorporation of the particulate solid into the coating-ink system is only possible with the use of suitable wetting-dispersing agents. Thus, in these systems, dispersants are often used to stabilize the particulate solids in the system, to reduce the viscosity of the system, to improve flowability, and to more optimally exhibit the properties of the particulate matter itself.

Wetting dispersing aids are generally surface-active substances having a cationic, anionic or nonionic structure. These substances can be applied directly to the particulate solid or can be added to a dispersion of the particulate solid. Dispersing aids known to promote dispersion of particulate solids and/or prevent agglomeration include fatty carboxylic acids, organosilicon compounds, alkanolamines, polyols, and the like, for example, patent CN1846833A discloses a method for dispersing pigments based on a polymer obtained after reaction of a product obtained after ring opening of a lactone with an amino group; patent CN1749288A discloses a product obtained by copolymerization of carboxylic acid derivatives based on unsaturated double bonds and allyl polyether as wetting dispersant; patent US3980602 discloses a solution for stabilizing pigments with polyacrylates containing amine groups, patent EP159678 discloses the dispersion of polymers of amine groups of polyisocyanates as dispersants, etc. Although the above-mentioned dispersant can be used as a dispersion of some solid particles, in view of the wide variety of the existing solid particles, when the pigment or coating ink system is specially required, the above-mentioned system generally requires higher solid content and at the same time requires as low viscosity as possible, so that the use of the dispersant in the fields of pigment and coating ink has great limitation, and the problems of too high viscosity and thixotropy, flocculation due to poor dispersibility, poor flowability and the like exist in most cases.

There is still a need for improved dispersing aids for effectively dispersing particulate solids.

Disclosure of Invention

In order to solve the above problems, it is an object of the present invention to provide a wetting dispersant having good properties in terms of stabilization of a dispersion containing solid particles.

One aspect of the present invention provides an adduct compound suitable as a wetting and dispersing agent, the adduct compound having the general formula:

wherein R is₁Independently at each occurrence represents-H or-CH₃Group, R₂Independently at each occurrence, represents a C4-C8 linear alkyl group, and o is an integer between 1-200; radical R₃Independently at each occurrence, represents a polyether residue containing a repeating-C-O-structure or a polyester residue containing a repeating-COO-structure in the backbone, and p is an integer between 1 and 200; r₄Each occurrence independently represents an amino residue containing an-NH-structure in the backbone, and q is an integer between 1 and 100.

Further, the polyether residue R₃Has a structure represented by the following formula:

wherein R is¹Independently at each occurrence, represents C₁-C₁₈Alkyl radical, C₂-C₁₈Alkenylene radical, C₆-C₁₈Aralkyl group; wherein- (CH)₂CH₂O)_m-m is in the range of 0 to 100; wherein- (CH)₂CH₂CH₂O)_n-n is in the range of 0 to 100; wherein each occurrence of P independently represents an active hydrogen-containing group such as a hydroxyl group, a hydroxymethyl group, a primary amino group, a secondary amino group, or the like.

Another aspect of the present invention is to provide a wetting and dispersing agent for pigments and fillers comprising the above addition compound.

In another aspect, the present invention provides a method for preparing a wetting dispersant having a structure represented by a branched polymer prepared from a monomer mixture by transesterification.

Further, the method specifically comprises the following steps:

(i) providing at least one polyether containing active hydrogen represented by the following formula;

(ii) providing at least one compound containing amine active hydrogen;

(iii) carrying out ester exchange reaction on the polyether and the compound containing amine active hydrogen and a polyacrylate polymer to form the wetting dispersant;

In an embodiment of the present invention, the polyether compound is selected from one of polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether or polyethylene glycol monobutyl ether with a number average molecular weight of 200-3000, or one of polypropylene glycol monomethyl ether, polypropylene glycol monoethyl ether or polypropylene glycol monobutyl ether with a number average molecular weight of 200-3000, or is selected from random polyether with a number average molecular weight of 200-3000, or is selected from monoalkyl polyether amine with a number average molecular weight of 200-2000, and the monoalkyl polyether amine with a number average molecular weight of 200-2000 is from Huntsman corporation under the brand numbers of M600, M1000, M2000, M2005, M2070, and the like.

In an embodiment of the invention, the amine active hydrogen containing compound is selected from one or more of monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethylenepolyamine, polyethyleneimine, N-pyrrolidone, 1- (2-hydroxyethyl) piperazine, 2-aminopyridine, 4-aminopyridine, 2-aminoimidazole, 4-aminoimidazole, 1- (3-aminopropyl) imidazole, 1, 3-cyclohexyldimethylamine, diaminodicyclohexylmethane or isophoronediamine.

Compared with the prior art, the invention has the advantages that:

in the branched polymer based on the polyacrylate structure, the polyacrylate is used as a skeleton to provide wide compatibility of the dispersing agent and matrix resin and steric hindrance to solid particles, and meanwhile, the wetting capacity of a polyether component introduced through ester exchange reaction to the solid particles is enhanced, and amino residues are bonded and anchored to the surfaces of the solid particles.

Detailed Description

The present invention provides a branched polymer obtained by transesterification of a polyacrylate polymer, which is useful as a wetting dispersant for pigments and fillers, and for the purpose of facilitating understanding of the present invention, the present invention will now be described more fully with reference to the following examples, of which preferred examples are set forth below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Optional components not contemplated by the present invention are not contemplated to be excluded from the composition where the composition is described as including or comprising specific components, and the composition is contemplated to be comprised of or consisting of the recited components, or optional process steps not contemplated by the present invention are contemplated to be excluded from the method where the method is described as including or comprising specific process steps, and the method is contemplated to be comprised of or consisting of the recited process steps.

The terms "preferred" and "preferably" refer to embodiments of the invention that may provide certain benefits under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

As used herein, "a," "an," "the," "at least one," and "one or more" are used interchangeably. Thus, for example, a dispersion containing "a" particulate solid can be interpreted to mean that the dispersion contains "one or more" particulate solids.

For the sake of brevity, only some numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form ranges not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and similarly any upper limit may be combined with any other upper limit to form a range not explicitly recited. Also, although not explicitly recited, each point or individual value between endpoints of a range is encompassed within the range. Thus, each point or individual value can form a range not explicitly recited as its own lower or upper limit in combination with any other point or individual value or in combination with other lower or upper limits.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. At various points throughout this application, guidance is provided through a list of embodiments that can be used in various combinations. In each instance, the list serves only as a representative group and should not be construed as exhaustive.

The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are on a weight basis, and all reagents used in the examples are commercially available and can be used directly without further treatment.

Example 1

Synthesis of polyacrylate polymers

Polyacrylate Polymer 1

In a four-necked flask equipped with a thermometer, an overhead stirrer, a gas inlet and a condenser, 1196 parts of xylene, 300 parts of methyl methacrylate and 12 parts of di-t-butyl peroxide were charged. Setting the stirring speed at 200rpm, starting the stirring, introducing nitrogen, starting a temperature raising device, and setting the reaction temperature at 138 ℃. Meanwhile, 896 parts of butyl acrylate and 35.84 parts of di-tert-butyl peroxide are added into a beaker and stirred and mixed for later use. When the temperature of the materials in the flask is stabilized to 138 ℃, dropwise adding the mixed solution through a peristaltic pump, finishing dropwise adding at a constant speed within 2 hours, maintaining the temperature of 138 ℃ for reaction for 2 hours, cooling to 125 ℃, and removing the solvent xylene under reduced pressure at the temperature. Cooled to room temperature, thereby obtaining a polyacrylate polymer 1.

Polyacrylate Polymer 2

In a four-necked flask equipped with a thermometer, an overhead stirrer, a gas inlet and a condenser, 1588 parts of xylene, 300 parts of methyl methacrylate and 12 parts of di-t-butyl peroxide were charged. Setting the stirring speed at 200rpm, starting the stirring, introducing nitrogen, starting a temperature raising device, and setting the reaction temperature at 138 ℃. Meanwhile, 1288 parts of isooctyl acrylate and 51.52 parts of di-tert-butyl peroxide are added into a beaker and stirred and mixed for standby. When the temperature of the materials in the flask is stabilized to 138 ℃, dropwise adding the mixed solution through a peristaltic pump, finishing dropwise adding at a constant speed within 2 hours, maintaining the temperature of 138 ℃ for reaction for 2 hours, cooling to 125 ℃, and removing the solvent xylene under reduced pressure at the temperature. Cooled to room temperature, thereby obtaining polyacrylate polymer 2.

Polyacrylate Polymer 3

In a four-necked flask equipped with a thermometer, an overhead stirrer, a gas inlet and a condenser, 2078 parts of xylene, 300 parts of methyl methacrylate and 12 parts of di-t-butyl peroxide were charged. Setting the stirring speed at 200rpm, starting the stirring, introducing nitrogen, starting a temperature raising device, and setting the reaction temperature at 138 ℃. Meanwhile, 1778 parts of lauryl methacrylate and 71.12 parts of di-tert-butyl peroxide are added into a beaker and stirred and mixed well for later use. When the temperature of the materials in the flask is stabilized to 138 ℃, dropwise adding the mixed solution through a peristaltic pump, finishing dropwise adding at a constant speed within 2 hours, maintaining the temperature of 138 ℃ for reaction for 2 hours, cooling to 125 ℃, and removing the solvent xylene under reduced pressure at the temperature. Cooled to room temperature, thereby obtaining a polyacrylate polymer 3.

Synthesis of dispersants

Dispersant 1

1196 parts of polyacrylate polymer 1, 1500 parts of polyethylene glycol monomethyl ether (Mn. RTM. 750) were added under nitrogen protection to a four-necked flask equipped with a thermometer, overhead stirrer, gas inlet and condenser with a fractionating device and homogenized. Starting a temperature raising device, setting the reaction temperature to be 120 ℃, simultaneously starting stirring, setting the stirring speed to be 200rpm, starting the reaction when the reaction mixture reaches about 110 ℃, fractionating methanol serving as a product of the ester exchange reaction from a fractionator, collecting fractions, maintaining the temperature for reaction for 1 hour, heating the mixture to 160 ℃, keeping the temperature for reaction for 1 hour, collecting fractions, maintaining the temperature for reaction for 1 hour, and cooling to 110 ℃. The distillation temperature is controlled to be 66-70 ℃ in the whole reaction process, and 60.1 parts of fraction methanol is finally collected. Then 149 parts of triethanolamine were added, and at the beginning of the reaction at 110 ℃, methanol, which is a product of the transesterification reaction, was fractionated from the fractionator, and the fractions were collected, and the reaction temperature was maintained for 4 hours, and finally 30.2 parts of methanol, which was a fraction, were collected. The product was dissolved with propylene glycol methyl ether acetate at 1:1 to obtain dispersant 1.

Dispersant 2-9

Dispersants 2-9 were prepared similarly to dispersant 1, except that the polyacrylate polymer, polyether, and amine-containing active hydrogen compound were used in different types and amounts, as shown in table 1 below.

TABLE 1

Example 2: dispersions of particulate solids and thixotropic properties thereof

The dispersion aids 2, 5, 9 of the present invention (solid content 50%) or a commercially available dispersion aid EFKA4310 (solid content 50%) in the amounts shown in table 2 below were mixed with a hydroxyacrylic resin (solid content 60%), colored carbon black FW200 in powder form, propylene glycol methyl ether acetate, respectively, and dispersed in Dispermat with glass beads at 40 ℃ for 1 hour to obtain dispersions 1,2,3 of particulate solids and a control dispersion.

TABLE 2

Note: the viscosity of the dispersion of particulate solids was measured using a Brookfield LVDV-I Prime viscometer using spindle number 3

The results show that the pigment particle solid dispersion containing the dispersant of the present invention exhibits lower viscosity and thixotropy, exhibiting more excellent dispersibility.

Example 3: dispersion of particulate solids and dispersion stability properties thereof

The 1,2,3 dispersion of example 2 was mixed with a hydroxy acrylic resin, a curing agent, according to the following dispersion: hydroxy acrylic resin: the curing agents were mixed uniformly in a ratio of 40:40:20 and applied to a BYK-Gardner comparative paper in a wet film thickness of 100 μm. After the coating material was dried at room temperature, the gloss of the coating film was measured and the L value of the coating film was measured using a color difference meter of BYK-Gardner at a test angle of 60 °.

Product source	Degree of gloss	Value of L
			Control	86	8.92
Dispersion 1	91	6.54
			Dispersion 2	92	6.33
Dispersion 3	95	4.89

The results show that the solid dispersion of pigment particles comprising the dispersant of the present invention exhibits higher gloss and lower L value (the black pigment appears darker), exhibiting more excellent dispersibility.

Claims

1. A wetting and dispersing agent is characterized in that the wetting and dispersing agent is an addition compound and has the following general formula:

wherein R is₁Independently at each occurrence represents-H or-CH₃Group, R₂Independently at each occurrence, represents a C4-C8 linear alkyl group, and o is an integer between 1-200;radical R₃Independently at each occurrence, represents a polyether residue containing a repeating-C-O-structure or a polyester residue containing a repeating-COO-structure in the backbone, and p is an integer between 1 and 200; r₄Each occurrence independently represents an amino residue containing an-NH-structure in the backbone, and q is an integer between 1 and 100.

2. The addition compound of claim 1, wherein the polyether residue R₃Has a structure represented by the following formula:

wherein R is¹Independently at each occurrence, represents C1-C18 alkyl, C2-C18 alkenylene, C6-C18 aralkyl; wherein- (CH)₂CH₂O)_m-m is in the range of 0 to 100; wherein- (CH)₂CH₂CH₂O)_n-n is in the range of 0 to 100; wherein P independently at each occurrence represents a hydroxyl, hydroxymethyl, primary amine or secondary amine group active hydrogen containing group.

3. The addition compound of claim 1, wherein the polyether residue has a number average molecular weight in the range of 200 to 3000 g/mol.

4. A process for the preparation of an adduct as claimed in any of claims 1 to 3, characterized in that a polyacrylate polymer of a specific structure is prepared, which is subsequently transesterified with a polyether containing active hydrogen and finally transesterified with an amine containing active hydrogen to give a branched polymer.

5. The method according to claim 4, characterized in that it comprises in particular the steps of:

(ii) carrying out ester exchange reaction on the polyether and a polyacrylate polymer with a specific structure to form a branched polymer;

(iii) (iii) reacting the branched polymer of step (ii) with a compound containing amine active hydrogens to form said addition compound;

6. Process according to claim 5, characterized in that the polyether residue R₃The polyether compound is selected from one of polyethylene glycol monomethyl ether, polyethylene glycol monoethyl ether or polyethylene glycol monobutyl ether with the number average molecular weight of 200-3000, also can be selected from one of polypropylene glycol monomethyl ether, polypropylene glycol monoethyl ether or polypropylene glycol monobutyl ether with the number average molecular weight of 200-3000, or is selected from random polyether with the number average molecular weight of 200-3000, or is selected from monoalkyl polyether amine with the number average molecular weight of 200-2000.

7. The method of claim 5, wherein the amine-active hydrogen containing compound is selected from one or more of monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethylenepolyamine, polyethyleneimine, N-pyrrolidone, 1- (2-hydroxyethyl) piperazine, 2-aminopyridine, 4-aminopyridine, 2-aminoimidazole, 4-aminoimidazole, 1- (3-aminopropyl) imidazole, 1, 3-cyclohexyldimethylamine, diaminodicyclohexylmethane, or isophoronediamine.

8. Use of the addition compounds according to any of claims 1 to 3 as wetting dispersants for solid particles.