Comb copolymer and its preparation method and application

Abstract

The present invention relates to a comb-like copolymer and a preparation method and application thereof. The comb-like copolymer is synthesized by post-modification of an anhydride-containing polymer (for example, formed by free radical copolymerization of styrene and maleic anhydride), and a nitro group is introduced into the anhydride-containing polymer using a novel neutral anchoring group. By using the neutral nitro group as an anchoring group, the problem of coating instability caused by catalytic reaction is solved, thereby greatly prolonging the storage time of the coating preparation, and overcoming the technical problem of instability of the coating preparation caused by the dispersant in the prior art.

Description

Technical Field

[0001] The invention belongs to the field of polymer synthesis and application, relates to a novel comb-shaped copolymer and its application as a dispersant in the coating and ink industries, and in particular to a compound formed by modifying anhydride polymers. Background Art

[0002] In the coating, ink and paint millbase industries, effective dispersants are required to evenly distribute particulate solids in aqueous, polar or non-polar organic media (e.g. liquid adhesives). Poor pigment or ink dispersion results in flocculation, aggregation or sedimentation in organic or aqueous liquid media (e.g. inks, paints or coatings), resulting in reduced gloss, color or hue shift and poor storage stability.

[0003] To achieve effective dispersion, the premix of pigment in liquid undergoes a three-stage dispersion process.

[0004] The first stage is the wetting stage, where the wetting agent and / or dispersant must be able to surround the solid surface, interact with the solid surface to eliminate any air or moisture on the solid surface, and promote wetting. Some dispersants with anchoring groups can achieve the above functions, for example, some hydrophilic anchoring groups can include tertiary amino groups, protonated or quaternized amino groups, phosphoric acid groups, carboxylic acid groups, sulfonic acid groups or amides, urethane and / or urea groups, etc.

[0005] The second stage is the grinding stage. After the wetting stage, high shear grinding equipment is used to provide mechanical action to de-agglomerate and de-agglomerate pigment particles. The system is sheared to produce smaller particles, effectively breaking up the agglomerates into independent particles.

[0006] The third stage is the stabilization stage of the dispersion. Dispersions such as pigments should remain stable during the storage stage after paint preparation or during application and film formation. Stabilization is achieved by adsorbing stable molecules on the surface of the pigment, which gives the particles a repulsive force sufficient to prevent other particles from getting too close and causing complex coagulation and flocculation.

[0007] The dispersing effect of dispersants on pigment particles in the suspension medium is mainly achieved through three mechanisms: electrostatic stabilization mechanism, steric stabilization mechanism and electrostatic steric stabilization mechanism. When the dispersant contains charge carriers, an electrostatic stabilization effect occurs. After adsorption of the dispersant, the surface of the pigment particles will be charged. When the dispersant contains oligomers or polymer chains, steric hindrance will occur. When two pigment particles approach each other, the macromolecular structure of the dispersant penetrates each other, resulting in steric hindrance and loss of freedom. This unfavorable reduction in entropy prevents further attraction.

[0008] Generally, dispersants are amphiphilic copolymers consisting of the following two segments: a relatively hydrophobic pigment affinity anchoring chain and a relatively hydrophilic stabilizing chain. The copolymer stabilizing chain can be various microstructures of the copolymer, including but not limited to random or statistically significant structures, alternating structures, gradient structures, block structures, grafted structures or comb-like structures, star-shaped or hyperbranched structures, etc. In the prior art, the United States Patents with publication numbers US6423785 and US8129476 all describe the synthesis of comb-like block copolymers and use them as pigment dispersants. In these embodiments, random copolymers (SMA, Styrene-Maleic Anhydride) synthesized by styrene and maleic anhydride are used as anhydride-containing polymers, and the reaction between anhydride and amine and hydroxyl groups introduces polyester or polyether side chains. More importantly, alkaline tertiary amine groups are also introduced into the SMA polymer as anchoring groups. When solid pigment particles are dispersed in solvents or water, these dispersants described in the embodiments disclosed in the above patents show quite good performance. However, when using pigment dispersions dispersed by these dispersants in resins to make liquid coatings, some problems may occur. These basic tertiary amine groups can gradually catalyze undesirable crosslinking reactions of certain resins, resulting in increased viscosity of the coating. For example, basic tertiary amine groups can catalyze the ring opening reaction of epoxy resins, resulting in increased viscosity or even solidification during storage of the coating.

[0009] In view of this, how to design a new comb copolymer that can be used as a dispersant to eliminate the above-mentioned defects and shortcomings in the prior art is a problem that needs to be solved urgently by relevant technical personnel in the industry. Summary of the invention

[0010] In order to overcome the technical problem of coating instability caused by dispersants in the prior art, the technical solution of the present invention utilizes a novel neutral anchoring group to introduce nitro groups into anhydride-containing polymers, and uses the neutral nitro groups as anchoring groups to solve the problem of coating instability caused by catalytic reactions, thereby greatly extending the storage time of the coating.

[0011] Specifically, the present invention relates to a comb copolymer, which can be synthesized by post-modification of an anhydride-containing polymer (for example, formed by free radical copolymerization of styrene and maleic anhydride). For example, the post-modification can refer to the reaction between the anhydride group and the amine or hydroxyl group, thereby introducing a polyether chain into the anhydride-containing polymer as a side chain. For another example, the post-modification can also introduce a small molecular weight component into the anhydride-containing polymer to act as an anchoring group on the pigment surface.

[0012] In order to achieve the above-mentioned object of the invention, the first aspect of the present invention provides a comb-like copolymer, wherein the comb-like copolymer has the following structural formula:

[0013]

[0014] in,

[0015] The A group is O or NH;

[0016] The B group has at least one repeating unit including -CH2-CH2-O-, -CH(CH3)-CH2-O- and / or -CH2-CH2-CH2-CH2-O-;

[0017] The G group is a straight or branched alkyl group having C1-C20;

[0018] The D group is -NO2;

[0019] The E group is selected from the following groups: substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C8 heterocyclyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C15 heteroaryl with 1 to 6 nitrogen, oxygen and / or sulfur atoms, or a combination thereof; wherein the substituent of the E group is selected from the following group: halogen, C1-C8 alkyl, C1-C4 alkoxy, hydroxyl, primary amino, secondary amino, tertiary amino, sulfonic acid, carboxyl or carbonyl;

[0020] n is 1 or 2 or 3;

[0021] Among them, 2≤x≤60,1≤y+z≤20,0≤p≤20,1≤q+s≤20, and the ratio of x:(y+z+p+q+s) is 1:1 to 4:1.

[0022] According to some embodiments of the present invention, when group B is a repeating unit of -CH2-CH2-O- and -CH(CH3)-CH2-O-, the molar ratio of the two is in the range of 1:10 to 10:1. Preferably, the molar ratio of the two is in the range of 1:6 to 6:1.

[0023] According to some embodiments of the present invention, group B has a molecular weight in the range of 500 to 5000 g / mol. Preferably, group B has a molecular weight in the range of 800 to 2500 g / mol. Most preferably, group B has a molecular weight in the range of 1000 to 2000 g / mol.

[0024] According to some embodiments of the present invention, group E is a benzene ring, naphthalene imine and its derivatives.

[0025] According to some embodiments of the present invention, the group G is a straight or branched alkyl group having 1 to 6 carbon atoms; preferably, the group G is a methyl group.

[0026] According to some embodiments of the present invention, the preferred ranges of x, y, z, p, q, s are 4≤x≤20, 2≤y+z≤10, 0≤p≤10, and 2≤q+s≤10.

[0027] The second aspect of the present invention provides a comb-like copolymer. A method for preparing the comb-like copolymer comprises the steps of:

[0028] (1) providing a copolymer a of styrene and maleic anhydride;

[0029] (2) providing a polyether b having an amino group or a hydroxyl group as a terminal group at one end; and

[0030] (3) providing a substituted compound c containing at least one hydroxyl group, primary amino group or secondary amino group and at least one carboxyl group, sulfonic acid group, phosphoric acid group or nitro group; and

[0031] (4) Compounds a, b and c are reacted to obtain the comb copolymer.

[0032] According to some embodiments of the present invention, copolymer a is synthesized by free radical polymerization of comonomers consisting of styrene and maleic anhydride, SMA being well known in the art.

[0033] In order to obtain a high density of modifiable sites, the molar ratio of styrene to maleic anhydride units is preferably 1:1 to 3:1. Meanwhile, in order to adjust the molecular weight of the SMA, those skilled in the art are aware that a chain transfer agent may be added.

[0034] Of course, the polymer a (SMA product) used in the present invention can be obtained commercially, such as Polyscope Cray Valley's SMA or Solenis'

[0035] According to some embodiments of the present invention, polyether b provides a stabilizing effect of copolymer a on the pigment through a steric hindrance mechanism. The first requirement of polyether b is that the molecular weight of its polymer chain is sufficient to provide sufficient steric repulsion; the second requirement is that it contains functional groups reactive to the anhydride groups of copolymer a. The polymer chain that meets the first requirement can be a polyether. The second requirement can be met by a nucleophilic functional group, which includes but is not limited to an amine, a hydroxyl group or a thiol.

[0036] Preferably, the polyether b is terminated with a primary amine group and is formed by polymerization of ethylene oxide and propylene oxide. For example, an amine-terminated polyether reacts with an anhydride group of copolymer a to form an amic acid group, which, under further heating (e.g., above 110° C.), can remove water and further be converted into a maleimide group.

[0037] The other end of the polyether b is capped with an alkyl group.

[0038] Of course, polyether polyamine products are also commercially available, for example, Huntsman Clariant or BASF

[0039] According to some embodiments of the present invention, an anchoring group is introduced by post-modification of copolymer a by compound c. The first requirement of compound c is to contain a functional group reactive to the anhydride group of copolymer a, for example, a nucleophilic functional group, including but not limited to an amine group, a hydroxyl group and a thiol group. The second requirement of compound c is to contain a functional group suitable for adhering to the surface of the pigment, i.e., an anchoring group. For example, for inorganic pigments, such functional groups are usually characterized by polar structures, such as tertiary amines, ammonium, acid-neutralized amines, carboxyl groups, sulfonic acids, phosphoric acids and nitro groups; for organic pigments, these functional groups are usually characterized by aromatic rings, such as benzene rings and heterocycles. More preferably, the nitro group connected to the aromatic ring can be used as a neutral anchoring group. As mentioned in the prior art, the alkaline functional group can gradually catalyze the undesirable cross-linking reaction of a specific resin, thereby causing the viscosity of the coating of some resin systems to increase during storage. For example, the alkaline tertiary amine group can catalyze the ring-opening reaction of the epoxy resin, which will cause the resin to solidify during the storage of the coating. The neutral anchoring group used in the present invention can solve this problem well.

[0040] Preferably, compound c contains a chemically neutral nitro group to adhere to the pigment surface, and an amine or hydroxyl group to react with the anhydride groups of copolymer a.

[0041] The compound c is a nitro-substituted aromatic compound, including but not limited to 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,4-dinitroaniline, 3,5-dinitroaniline, 2-methyl-3-nitroaniline, 2-methyl-4-nitroaniline, 4-nitro-2-(trifluoromethyl)aniline, 4-nitro-o-phenylenediamine, 2-nitro-1,4-phenylenediamine, 2-nitro-L-tyrosine, 3-nitro-L-tyrosine, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2-nitro-1-naphthol, 3-nitro-1-naphthol, 4-nitro-1-naphthol, 5-nitro-2-naphthol, 2-benzyl-4-nitro-1-naphthol, 2-(2-hydroxyethyl)-2-nitro -1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-3-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-4-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-3,6-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-4,5-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-3,5-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 8-((2-hydroxyethyl)carbamoyl) )-2-nitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-3-nitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-4-nitro-1-naphthoic acid, 8-(((2-hydroxyethyl)carbamoyl)-3,6-dinitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-4,5-dinitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-3,5-dinitro-1-naphthoic acid, 2-(3-hydroxypropyl)-2-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(3-hydroxypropyl)-3-nitro-1H-benzo[iso]quinoline-1,3(2H)-dione, 2-(3- 2-(3-Hydroxypropyl)-4-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(3-Hydroxypropyl)-3,6-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(3-Hydroxypropyl)-4,5-dinitro-1H-benzo[iso]isoquinoline-1,3(2H)-dione, 2-(3-Hydroxypropyl)-3,5-dinitro-1H-benzo[iso]isoquinoline-1,3(2H)-dione, 8-((3-Hydroxypropyl)carbamoyl)-2-nitro-1-naphthoic acid, 8-(((3-Hydroxypropyl)-3-nitro-1-naphthoic acid, 8-((3-Hydroxypropyl)-4-nitro-1-naphthoic acid, 8-((3-Hydroxypropyl)-3,6-Dinitro-1-naphthoic acid, 8-(((3-hydroxypropyl)-4,5-dinitro-1-naphthoic acid, 8-((3-hydroxypropyl)-3,5-dinitro-1-naphthoic acid.,

[0042] The third aspect of the present invention provides a composition, comprising a solid material selected from a pigment and a filler, and the comb-like copolymer as described above, wherein the weight ratio of the comb-like copolymer to the solid material is 0.005 to 1.5.

[0043] A fourth aspect of the present invention provides the use of a comb copolymer as described above as a dispersant or wetting agent.

[0044] Compared with the prior art, the technical solution provided by the present invention has the following advantages: the technical solution of the present invention adopts a novel neutral anchoring group to introduce a nitro group into anhydride-containing polymer, and uses the neutral nitro group as an anchoring group to solve the problem of coating instability caused by catalytic reaction, thereby greatly extending the storage time of the coating. DETAILED DESCRIPTION

[0045] It should be understood that the present invention is not limited to the embodiments described below, and the technical concept of the present invention can be implemented in combination with other well-known technologies or other technologies having the same functions as those well-known technologies.

[0046] Definitions of standard chemical terms can be found in references (including Carey and Sundberg "ADVANCED ORGANIC CHEMISTRY 4THED." Vols. A (2000) and B (2001), Plenum Press, New York). Unless otherwise stated, conventional methods within the technical scope of the art, such as mass spectrometry, NMR, IR and UV / VIS spectroscopy and pharmacological methods, are used. Unless specifically defined, the terms used herein in the relevant descriptions of analytical chemistry, organic synthetic chemistry, and drugs and medicinal chemistry are known in the art. Standard techniques can be used in chemical synthesis, chemical analysis, drug preparation, formulation and delivery, and in the treatment of patients. For example, the manufacturer's instructions for the use of the kit can be used, or the reaction and purification can be carried out in a manner known in the art or in accordance with the description of the present invention. The above-mentioned techniques and methods can usually be implemented according to the descriptions in the multiple summary and more specific documents cited and discussed in this specification, according to conventional methods well known in the art. In this specification, groups and substituents thereof can be selected by those skilled in the art to provide stable structural parts and compounds.

[0047] When substituents are described by conventional chemical formulas written from left to right, the substituents also include chemically equivalent substituents that would result if the formula were written from right to left. For example, -CH2O- is equivalent to -OCH2-.

[0048] The section headings used herein are only for the purpose of organizing the article and should not be interpreted as limitations on the subject matter described. All documents or portions of documents cited in this application, including but not limited to patents, patent applications, articles, books, operating manuals and papers, are incorporated herein by reference in their entirety.

[0049] Certain chemical groups defined herein are preceded by simplified symbols to indicate the total number of carbon atoms present in the group. For example, a C1-C6 alkyl group refers to an alkyl group as defined below having a total of 1 to 6 carbon atoms. The total number of carbon atoms in the simplified symbols does not include carbons that may be present in substituents of the group.

[0050] In addition to the foregoing, when used in the specification and claims of the present application, the following terms have the meanings indicated below unless otherwise specifically stated.

[0051] In the present application, the term "halogen" refers to fluorine, chlorine, bromine or iodine.

[0052] "Hydroxy" refers to an -OH group.

[0053] "Nitro" refers to -NO2.

[0054] "Cyano" refers to -CN.

[0055] In the present application, as a group or as part of other groups (for example, as used in groups such as halogen-substituted alkyl), the term "alkyl" refers to a fully saturated straight or branched hydrocarbon chain group consisting only of carbon atoms and hydrogen atoms, having, for example, 1 to 7 carbon atoms, and connected to the rest of the molecule by a single bond, including, but not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-methylbutyl, 2,2-dimethylpropyl, n-hexyl, heptyl, and the like.

[0056] In the present application, as a group or as part of other groups, the term "alkenyl" means a straight or branched hydrocarbon chain group consisting only of carbon atoms and hydrogen atoms, containing at least one double bond, having, for example, 2 to 8 (preferably 2 to 6) carbon atoms and connected to the rest of the molecule by a single bond, such as but not limited to vinyl, propenyl, allyl, but-1-enyl, but-2-enyl, pent-1-enyl, pent-1,4-dienyl, etc. As used herein, "C2-C30 (straight or branched) alkenyl" includes a single double bond, or multiple discontinuous double bonds.

[0057] In the present application, as a group or as part of other groups, the term "alkynyl" refers to a straight or branched hydrocarbon chain group consisting only of carbon atoms and hydrogen atoms, containing at least one triple bond, optionally containing at least one double bond, having, for example, 2 to 6 carbon atoms and connected to the rest of the molecule by a single bond, such as, but not limited to, ethynyl, prop-1-ynyl, but-1-ynyl, pent-1-ene-4-ynyl, etc. As used herein, "C2-C30 (straight or branched) alkynyl" includes a single triple bond, or multiple discontinuous triple bonds.

[0058] In the present application, the term "aromatic group", "aryl" as a group or part of other groups means a conjugated hydrocarbon ring system group having 6 to 18 carbon atoms (preferably 6 to 10 carbon atoms). For the purposes of the present invention, the aryl group can be a monocyclic, bicyclic, tricyclic or more ring system, and can also be fused with a cycloalkyl or heterocyclic group as defined above, provided that the aryl group is connected to the rest of the molecule through a single bond via an atom on the aromatic ring. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, etc.

[0059] In the present application, as a group or part of other groups, the term "heteroaryl" means a 5- to 16-membered conjugated ring system group having 1 to 15 carbon atoms (preferably 1 to 10 carbon atoms) and 1 to 6 heteroatoms selected from nitrogen, oxygen and sulfur in the ring. Unless otherwise specified in this specification, the heteroaryl group can be a monocyclic, bicyclic, tricyclic or more ring system, and can also be fused with a cycloalkyl or heterocyclic group as defined above, provided that the heteroaryl group is connected to the rest of the molecule through a single bond via an atom on the aromatic ring. The nitrogen, carbon or sulfur atoms in the heteroaryl group can be optionally oxidized; the nitrogen atom can be optionally quaternized. For the purpose of the present invention, heteroaryl is preferably a stable 5- to 12-membered aromatic group containing 1 to 5 heteroatoms selected from nitrogen, oxygen and sulfur, more preferably a stable 5- to 10-membered aromatic group containing 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, or a 5- to 6-membered aromatic group containing 1 to 3 heteroatoms selected from nitrogen, oxygen and sulfur. Examples of heteroaryl groups include, but are not limited to, thienyl, imidazolyl, pyrazolyl, thiazolyl, oxazolyl, oxadiazolyl, isoxazolyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, benzimidazolyl, benzopyrazolyl, indolyl, furanyl, pyrrolyl, triazolyl, tetrazolyl, triazinyl, indolizinyl, isoindolyl, indazolyl, isoindazolyl, purinyl, quinolyl, isoquinolyl, naphthazinyl, naphthyridinyl, quinoxalinyl, pteridinyl, carbazolyl, carbolinyl, phenanthridinyl, phenanthrolinyl, acridinyl, phenazinyl, isothiazolyl, benzothiazolyl, benzothiophenyl, oxatriol, oxazolyl, cinnolinyl, quinazolinyl, phenylthio, indolizinyl, o-phenanthroline, isoxazolyl, phenoxazinyl, phenothiazinyl, 4,5,6,7-tetrahydrobenzo[b]thienyl, naphthopyridinyl, [1,2,4]triazolo[4,3-b]pyridazine, [1,2,4]triazolo[4,3-a]pyrazine, [1,2,4]triazolo[4,3-c]pyrimidine, [1,2,4]triazolo[4,3-a]pyridine, imidazo[1,2-a]pyridine, imidazo[1,2-b]pyridazine, imidazo[1,2-a]pyrazine, etc.

[0060] In the present application, "optionally" or "optionally" means that the event or situation described subsequently may or may not occur, and the description includes both the occurrence and non-occurrence of the event or situation. For example, "optionally substituted aryl" means that the aryl is substituted or unsubstituted, and the description includes both substituted aryl and unsubstituted aryl. The "optionally" substituents described in the claims and the specification of the present invention are selected from alkyl, alkenyl, alkynyl, halogen, haloalkyl, haloalkenyl, haloalkynyl, cyano, nitro, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted cycloalkyl, and optionally substituted heterocycloalkyl.

[0061] As used herein, the terms "part", "moiety", "chemical moiety", "group", "chemical group" refer to a specific fragment or functional group in a molecule. A chemical moiety is generally considered to be a chemical entity embedded in or attached to a molecule.

[0062] When the compounds of the present invention contain olefinic double bonds, and unless specified otherwise, it is intended that the compounds of the present invention include both E- and Z- geometric isomers.

[0063] The term "anhydride group" refers herein to a group of atoms according to the formula: ... -C(=O)-OC(=O)-...

[0064] The term "solid material may be a pigment or a filler.

[0065] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly specified.

[0066] Unless clearly indicated to the contrary, each aspect or embodiment defined herein may be combined with any other aspect or embodiments. In particular, any feature indicated as preferred or advantageous may be combined with any other feature indicated as preferred or advantageous.

[0067] Preparation of intermediates

[0068] Intermediate 1

[0069] First, 120 g of methoxypropyl acetate and 23.2 g of 2,4-diphenyl-4-methyl-1-pentene were added to the reaction bottle, and the temperature was raised to 140°C. Then, 9.3 g of styrene was added to the reaction bottle. Next, 72.8 g of maleic anhydride was dissolved in 83.1 g of methoxypropyl acetate, and within 1.5 hours, 151.9 g of the above solution and 11 g of 2,2-azobis(2-methylbutyronitrile) were added. Within the same 1.5 hours, 84.6 g of styrene was added to the reaction bottle. Before the reaction was completed, the temperature of 140°C was maintained for 1 hour. Stirring was performed throughout the reaction. Finally, a transparent yellow-brown liquid SMA copolymer solution was obtained, and methoxypropyl acetate solvent was added to adjust the solid content to 50%, that is, intermediate 1, Mn=1800 g / mol.

[0070] Intermediate 2

[0071] First, 20 g of 3-nitro-1,8-naphthalene dicarboxylic anhydride was dissolved in dimethylacetamide, and then 5.52 g of ethanolamine was added to the mixture. Then, the mixture was refluxed at 160°C under a nitrogen atmosphere. After 4 hours, dimethylacetamide was removed under vacuum. Stirring was performed throughout the reaction process, and finally a dark red powder of 2-(2-hydroxyethyl)-6-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, namely intermediate 2, was obtained.

[0072] Preparation of dispersants

[0073] Example 1: Dispersant 1

[0074] Under nitrogen atmosphere, 20 g of intermediate 1 was added to 27 g of methoxypropyl acetate in an oil bath at 160°C. Next, 20 g of Genamin m41 / 2000 was added to the mixture. After 10 minutes, 1.78 g of 4-nitroaniline was added to the mixture. After the mixture was magnetically stirred for 1 hour, the methoxypropyl acetate was removed under vacuum. The magnetic stirring was continued and the oil bath temperature was kept constant. The reaction was terminated after 4 hours. Finally, the product was diluted in water to a solid content of 40% after cooling to obtain dispersant 1.

[0075] Example 2: Dispersant 2

[0076] Under nitrogen atmosphere, 10 g of Xiran 1000 (Polyscope, SMA synthetic resin) was dissolved in 47 g of methoxypropyl acetate in a 160°C oil bath. Next, 34.3 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 3.26 g of 4-nitroaniline was added to the mixture. After the mixture was magnetically stirred for 1 hour, methoxypropyl acetate was removed under vacuum. Magnetic stirring was continued, and the oil bath temperature was kept constant, and the reaction was terminated after 4 hours. Finally, after cooling, the product was diluted in water to a solid content of 40% to obtain dispersant 2.

[0077] Example 3: Dispersant 3

[0078] Under nitrogen atmosphere, 10 g of Xiran 1000 (SMA synthetic resin) was dissolved in 47 g of methoxypropyl acetate in a 160°C oil bath. Next, 34.3 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 3.26 g of 3-nitroaniline was added to the mixture. After the mixture was magnetically stirred for 1 hour, the methoxypropyl acetate was removed under vacuum. The magnetic stirring was continued and the oil bath temperature was kept constant. The reaction was terminated after 4 hours. Finally, the product was diluted in water to a solid content of 40% after cooling to obtain dispersant 3.

[0079] Example 4: Dispersant 4

[0080] Under nitrogen atmosphere, 10 g of Xiran 1000 (SMA synthetic resin) was dissolved in 47 g of methoxypropyl acetate in a 160°C oil bath. Next, 34.3 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 4.32 g of 2,4-dinitroaniline was added to the mixture. After the mixture was magnetically stirred for 1 hour, the methoxypropyl acetate was removed under vacuum. The magnetic stirring was continued and the oil bath temperature was kept constant. The reaction was terminated after 4 hours. Finally, the product was diluted in water to a solid content of 40% after cooling to obtain dispersant 4.

[0081] Example 5: Dispersant 5

[0082] Under nitrogen atmosphere, 5 g of Xiran 1000 (SMA synthetic resin) was dissolved in 15 g of methoxypropyl acetate and 15 g of dimethylacetamide in a 160°C oil bath. Next, 23.6 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 1.84 g of intermediate 2 was added to the mixture. After the mixture was magnetically stirred for 1 hour, methoxypropyl acetate was removed under vacuum conditions. Magnetic stirring was continued, and the oil bath temperature was kept constant, and the reaction was terminated after 4 hours. Finally, after cooling, the product was diluted in water to a solid content of 40% to obtain dispersant 5.

[0083] Example 6: Dispersant 6

[0084] Under nitrogen atmosphere, 10 g of Xiran 1000 (SMA synthetic resin) was dissolved in 47 g of methoxypropyl acetate in a 160°C oil bath. Next, 17 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 2.16 g of 2,4-dinitroaniline was added to the mixture. After the mixture was magnetically stirred for 4 hours, the oil bath temperature was lowered to 60 degrees, and 17 g of Genamin m41 / 2000 was added to the mixture again. After 30 minutes, 2.16 g of 2,4-dinitroaniline was added to the mixture again, and the reaction was continued for 2 hours. Then methoxypropyl acetate was removed under vacuum conditions. Finally, after cooling, the product was diluted in water to a solid content of 40% to obtain dispersant 6.

[0085] Example 7: Dispersant 7

[0086] Under nitrogen atmosphere, 10 g of Xiran 2000 (SMA synthetic resin) was dissolved in 47 g of methoxypropyl acetate in a 160°C oil bath. Next, 17 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 1.5 g of 4-nitroaniline was added to the mixture. After the mixture was magnetically stirred for 4 hours, the oil bath temperature was lowered to 60 degrees, and 17 g of Genamin m41 / 2000 was added to the mixture again, and stirring was continued for 2 hours. Then, methoxypropyl acetate was removed under vacuum conditions. Finally, after cooling, the product was diluted in water to a solid content of 40% to obtain dispersant 7.

[0087] Comparative Example 1: Dispersant C1

[0088] Under nitrogen atmosphere, 20 g of Xiran 1000 (SMA synthetic resin) was dissolved in 50 g of methoxypropyl acetate in a 160°C oil bath. Next, 60 g of Genamin m41 / 2000 was added to the mixture. After 30 minutes, 1.9 g of N,N-dimethylaminopropylamine was added to the mixture. After the mixture was magnetically stirred for 1 hour, methoxypropyl acetate was removed under vacuum. Magnetic stirring was continued, and the oil bath temperature was kept constant, and the reaction was terminated after 4 hours. Finally, after cooling, the product was diluted in water to a solid content of 40% to obtain dispersant C1.

[0089] Table 1 below gives the number and molecular weight information of different structural units of dispersants 1-7. The different structural units are calculated based on the feed and reaction conditions. The comparative dispersant has a basic tertiary amino group as an anchoring group. The molecular weight is measured by GPC instrument (Agilent 1200) with tetrahydrofuran as the eluent.

[0090] As shown in Table 1 below, Mn is the number average molecular weight; Mw is the weight average molecular weight; and PDI is the polymer dispersion index.

[0091] Table 1 Structural units and molecular weights of dispersants 1-7

[0092] x y z p q s Mn M PDI Dispersant 1 8 0 2 4 0 2 7930 14195 1.79 Dispersant 2 9 0 3 2 0 4 8780 15189 1.73 Dispersant 3 9 0 3 2 0 4 8880 16339 1.84 Dispersant 4 9 0 3 2 0 4 8700 14703 1.69 Dispersant 5 9 0 4 2 0 3 9110 14849 1.63 Dispersant 6 9 2 2 1 2 2 9350 15615 1.67 Dispersant 7 14 2 2 1 0 2 9620 15488 1.61 Dispersant C1 7 0 2 5 0 0 6990 12932 1.85

[0093] The following uses the dispersants of Examples 1-7 and Comparative Example 1 to prepare pigment dispersions to evaluate the color strength and glossiness of the pigment dispersions in the resin system.

[0094] First, a pigment dispersion with the formula shown in Table 2 was prepared. The pigment dispersion process was carried out using Lau Disperser DAS200 (Germany LAUDAS200 high-speed ink oscillator) with 0.8 mm zirconium oxide beads as grinding media. Mitsubishi carbon black pigment (MA100) and Ti-Pure titanium dioxide (R960) were used as black and white pigments to evaluate dispersants, and BASF's FormStart SI2280 and Evonik's Surfynol 440 were used as defoamers and wetting agents, respectively.

[0095] Table 2: Pigment dispersion formulation

[0096]

[0097]

[0098] Then, the epoxy resin emulsion and the pigment dispersion prepared above are used to prepare a liquid coating. The preparation method is as follows: 2.5 grams of the carbon black pigment dispersion and 30 grams of the titanium white pigment dispersion are added to 90 grams of the epoxy resin emulsion under stirring, and the liquid coating is prepared after stirring for 30 minutes. Before coating, a curing agent accounting for about 40% of the total weight needs to be added.

[0099] The liquid coating was applied to a black and white paint card using a 150 μm film applicator to obtain a wet film with a thickness of 150 μm. The wet film was flash-dried at room temperature for 15 minutes and then cured at 80° C. for 30 minutes to obtain a cured dry film.

[0100] The color coordinates (L, a, b) of the dry film were measured using a BYK Gardner Spectro-Guide color spectrophotometer. The gloss (20° and 60°) of the dry film was measured using a BYK Gardner micro-TRI gloss meter. The results are shown in Table 3 below.

[0101] Table 3: Color strength and gloss results of paint films prepared with different dispersants

[0102] Dispersants L a b Gloss (20°) Gloss (60°) Dispersant 1 48.7 -1.0 -3.7 90 98 Dispersant 2 48.4 -0.9 -3.8 94 100 Dispersant 3 48.3 -1.2 -4.2 93 99 Dispersant 4 48.9 -1.4 -3.7 91 98 Dispersant 5 48.1 -0.8 -3.9 93 97 Dispersant 6 48.4 -1.0 -3.5 95 99 Dispersant 7 48.1 -1.4 -3.1 91 99 Dispersant C1 48.2 -0.9 -4.1 92 99

[0103] As can be seen from Table 3, the dispersants prepared in the embodiments and comparative examples of the present invention have almost the same color development effect in terms of the color development of the pigment. The measurement range of the L value is 0 to 100. The smaller the L value, the darker the paint film (the higher the blackness), which corresponds to the better dispersion of the pigment. The gloss of the paint film is also related to the dispersion degree of the pigment. When the pigment particles are aggregated, the gloss of the paint film will usually decrease. Therefore, the larger the gloss value, the better the dispersion effect of the pigment.

[0104] The dispersant in the invention not only has a color development effect similar to that of the comparative example, but also solves the problem of increased viscosity of epoxy resin system liquid coating preparations during storage.

[0105] Table 4 shows the viscosity data comparison of epoxy emulsion blank (without pigment dispersion and curing agent) and liquid coating (with white and black dispersions prepared with different dispersants and without curing agent) after storage at 50°C for two weeks.

[0106] By comparison, it can be seen that although the viscosity of the blank sample and the liquid coating to which the dispersion prepared by the embodiment of the present invention is added increases slightly, the increase in viscosity is within an acceptable range.

[0107] In contrast, the viscosity of the liquid coating to which the dispersion prepared in the comparative example was added increased more greatly, reaching a level that affected its use.

[0108] Therefore, the use of neutral anchoring groups can effectively solve the problem of increased viscosity of epoxy emulsion coatings during storage caused by alkaline dispersants, and even product deterioration.

[0109] The viscosity data were measured using an Anton Paar MCR302 viscometer, and the viscosity data are shown in Table 4 below.

[0110] Table 4: Viscosity data of liquid coating after storage at 50°C for two weeks (0.1s -1 )contrast

[0111] Dispersants Before storage (mpa s) After storage Blank 2500 3200 Dispersant 1 1600 2100 Dispersant 2 1800 2000 Dispersant 3 1800 2200 Dispersant 4 1600 2000 Dispersant 5 1500 2300 Dispersant 6 1700 2500 Dispersant 7 1900 2900 Dispersant C1 1700 20300

[0112] Unless otherwise specified, the qualifiers similar to "first" and "second" appearing in this article do not refer to the limitation of time sequence, quantity, or importance, but are only used to distinguish one technical feature from another technical feature in the technical solution. Similarly, the qualifiers similar to "one" appearing in this article do not refer to the limitation of quantity, but describe the technical features that have not appeared in the previous text. Similarly, modifiers similar to "approximately" and "approximately" appearing before the numerals in this article usually include the number itself, and their specific meanings should be understood in conjunction with the context. Similarly, unless it is a noun modified by a specific quantitative quantifier, it should be regarded as including both singular and plural forms in this article, and the technical solution can include both the singular and plural technical features.

[0113] The preferred specific embodiments of the present invention are described in this specification. The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Any technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments according to the concept of the present invention should be within the scope of the present invention.

Claims

1. A comb copolymer, characterized in that The comb copolymer has the following structural formula: in, The A group is O or NH; The B group is a repeating unit comprising at least one -CH2-CH2-O-, -CH(CH3)-CH2-O- and / or -CH2-CH2-CH2-CH2-O-; The G group is a straight or branched alkyl group having C1-C20; The D group is -NO2; The E group is selected from the following groups: substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C8 heterocyclyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C15 heteroaryl with 1 to 6 nitrogen, oxygen and / or sulfur atoms, or a combination thereof; wherein the substituent of the E group is selected from the following group: halogen, C1-C8 alkyl, C1-C4 alkoxy, hydroxyl, primary amino, secondary amino, tertiary amino, sulfonic acid, carboxyl or carbonyl; n is 1 or 2 or 3; Among them, 2≤x≤60,1≤y+z≤20,0≤p≤20,1≤q+s≤20, and the ratio of x:(y+z+p+q+s) is 1:1 to 4:1; The comb copolymer is used as a dispersant or a wetting agent in an epoxy resin system liquid coating.

2. The comb copolymer according to claim 1, characterized in that When group B is a repeating unit of -CH2-CH2-O- and -CH(CH3)-CH2-O-, the molar ratio of the two is in the range of 1:10 to 10:

1.

3. The comb copolymer according to claim 1, characterized in that The group B has a molecular weight in the range of 500 to 5000 g / mol.

4. The comb copolymer according to claim 1, characterized in that The group E is a benzene ring or naphthalene imine.

5. The comb copolymer according to claim 1, characterized in that The group G is a straight or branched chain alkyl group having 1 to 6 carbons.

6. The comb copolymer according to claim 5, characterized in that The group G is a methyl group.

7. The comb copolymer according to claim 1, characterized in that 4≤x≤20, 2≤y+z≤10, 0≤p≤10, and 2≤q+s≤10.

8. A method for preparing the comb copolymer according to any one of claims 1 to 7, comprising the steps of: (1) providing a copolymer a of styrene and maleic anhydride; (2) providing a polyether b having an amino group or a hydroxyl group as a terminal group at one end; (3) providing a nitro-substituted aromatic compound or a compound c of naphthalene imine and its derivatives; and (4) Compounds a, b and c are reacted to obtain the comb copolymer.

9. The method according to claim 8, characterized in that In the copolymer a, the molar ratio of the styrene unit to the maleic anhydride unit is 1:1 to 4:

1.

10. The method according to claim 8, characterized in that The polyether b has a primary amine end cap and is formed by polymerization of ethylene oxide and propylene oxide.

11. The method according to claim 8, characterized in that The other end of the polyether b is capped with an alkyl group.

12. The method according to claim 8, characterized in that The compound c is at least one compound selected from the group consisting of 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,4-dinitroaniline, 3,5-dinitroaniline, 2-methyl-3-nitroaniline, 2-methyl-4-nitroaniline, 4-nitro-2-(trifluoromethyl)aniline, 4-nitro-o-phenylenediamine, 2-nitro-1,4-phenylenediamine, 2-nitro-L-tyrosine, 3-nitro-L-tyrosine, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2-nitro-1-naphthol, 3-nitro-1-naphthol, 4-nitro-1-naphthol, 5-nitro-2-naphthol, 2-benzyl-4-nitro-1-naphthol, 2-(2- 2-(2-Hydroxyethyl)-2-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-3-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-4-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-3,6-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-4,5-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(2-hydroxyethyl)-3,5-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 8-(2-hydroxyethyl)- )carbamoyl)-2-nitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-3-nitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-4-nitro-1-naphthoic acid, 8-(((2-hydroxyethyl)carbamoyl)-3,6-dinitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-4,5-dinitro-1-naphthoic acid, 8-((2-hydroxyethyl)carbamoyl)-3,5-dinitro-1-naphthoic acid, 2-(3-hydroxypropyl)-2-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(3-hydroxypropyl)-3-nitro-1H-benzo[iso]quinoline-1,3(2H)-dione, 2- (3-Hydroxypropyl)-4-nitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(3-hydroxypropyl)-3,6-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione, 2-(3-hydroxypropyl)-4,5-dinitro-1H-benzo[iso]isoquinoline-1,3(2H)-dione, 2-(3-hydroxypropyl)-3,5-dinitro-1H-benzo[iso]isoquinoline-1,3(2H)-dione, 8-((3-hydroxypropyl)carbamoyl)-2-nitro-1-naphthoic acid, 8-(((3-hydroxypropyl)-3-nitro-1-naphthoic acid, 8-((3-hydroxypropyl)-4-nitro-1-naphthoic acid, 8-((3-hydroxypropyl)-3,6-dinitro-1-naphthoic acid, 8-(((3-hydroxypropyl)-4,5-dinitro-1-naphthoic acid, or 8-((3-hydroxypropyl)-3,5-dinitro-1-naphthoic acid.

13. A composition, characterized in that The composition comprises a solid material selected from pigments and fillers, and the comb copolymer according to any one of claims 1 to 7.

14. The composition according to claim 13, characterized in that The weight ratio of the comb copolymer to the solid material is 0.005 to 1.5.

Images