High-range water reducing polycarboxylate superplasticizer, preparation method therefor and use thereof

Abstract

The present invention belongs to the field of additives, and particularly relates to a high-range water reducing polycarboxylate superplasticizer, a preparation method therefor and the use thereof. The high-range water reducing polycarboxylate superplasticizer comprises a polyether structure unit, a carboxylic acid structure unit, an esterification structure unit and a phosphate structure unit. The high-range water reducing polycarboxylate superplasticizer provided by the present invention has good dispersing performance and water reducing rate, and thus has a wide application prospect.

Description

A high water-reducing polycarboxylate water-reducing agent and its preparation method and application

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application with application number 202311699107.5 filed with the Patent Office of China on December 12, 2023, entitled "A Highly Water-Reducing Polycarboxylate Water-Reducing Agent, Its Preparation Method and Application", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The invention belongs to the field of admixtures, and particularly relates to a high-water-reducing polycarboxylate water-reducing agent, a preparation method thereof, and an application thereof. Background Art

[0004] Polycarboxylate water reducers are the third generation of concrete water reducers. Polycarboxylate water reducers are mainly produced by copolymerizing unsaturated polyether macromonomers with unsaturated carboxylic acids / sulfonic acids. The most common polyether macromonomers on the market include allyl polyethylene glycol ether (APEG), methyl allyl polyethylene glycol ether (HPEG), and isopentenyl polyethylene glycol ether (TPEG). This type of polyether macromonomer has a simple synthesis process, stable chemical properties, and good product quality, but it also has a number of problems. On the one hand, HPEG and TPEG products account for the vast majority of existing polyether macromonomers, and the product structure is relatively simple. On the other hand, during the application of polyether macromonomers, some problems have emerged, such as incompatibility with concrete raw materials and extreme sensitivity to the mud content in sand and gravel. In recent years, the structure of polyether macromonomers on the market has undergone significant changes. Polyether manufacturers have launched new vinyl ether macromonomers, including 2+2 and 2+4 macromonomers (EPEG and VPEG). Vinyl ether macromonomers require a low initial reaction temperature, generally below 20°C. At the same time, in existing processes, the oxidant is generally added to the substrate all at once, while the reducing agent is added dropwise. In this case, refrigeration equipment is required to control the initial reaction temperature below 20°C. If the initial reaction temperature exceeds 20°C, the dispersion and slump retention properties of the prepared polycarboxylate superplasticizer will be significantly reduced. This defect has seriously hindered the promotion and application of vinyl ether polyether macromonomers in the superplasticizer industry. In addition, polycarboxylate superplasticizers often undergo involution due to their unstable molecular structure, resulting in a serious decline in dispersibility and water reduction rate.

[0005] Summary of the Invention

[0006] The first object of the present invention is to provide a highly water-reducing polycarboxylate water-reducing agent having excellent dispersibility and water-reducing rate.

[0007] The second object of the present invention is to provide a method for preparing a highly water-reducing polycarboxylate water-reducing agent.

[0008] The third object of the present invention is to provide a highly water-reducing polycarboxylate water-reducing agent prepared by the above method.

[0009] A fourth object of the present invention is to provide application of the highly water-reducing polycarboxylate water-reducing agent in the field of construction.

[0010] The high water-reducing polycarboxylate water-reducing agent provided by the present invention comprises a polyether structural unit, a carboxylic acid structural unit, an esterification structural unit and a phosphate structural unit, wherein the polyether structural unit has a structure represented by formula (1), the carboxylic acid structural unit has a structure represented by formula (2), the esterification structural unit has a structure represented by formula (3), and the phosphate structural unit has a structure represented by formula (4);

[0011] In formula (1), R 11 is a C1-C5 alkylene group, R 12 、R 13 and R 14 Each is independently H, C1-C5 alkyl or -OH, and n is an integer from 0 to 100;

[0012] In formula (2), R 21 and R 22 Each independently represents H, C1-C5 alkyl or -R 23 -COOH and R 21 and R 22 At least one of them is -R 23 -COOH, R 23 does not exist or is a C1-C5 alkylene group; when R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 Able to bond into a ring; R 21 ` and R 22 `Each independently is H or C1-C5 alkyl;

[0013] In formula (3), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 ` does not exist or is a C1-C5 alkylene group, R 31 `` is a C1-C5 alkyl group; R 32 R is absent or is a substituted or unsubstituted C1-C5 alkylene group; 33 、R34 or R 35 Each is independently H or a C1-C5 alkyl group;

[0014] In formula (4), R 41 is O or methylene, R 42 、R 43 and R 44 Each is independently H or a C1-C5 alkyl group, and m, p and q are each independently an integer from 0 to 3.

[0015] The preparation method of the high water-reducing polycarboxylate water-reducing agent provided by the present invention comprises the steps of subjecting an unsaturated polyether macromonomer having a structure represented by formula (5), an unsaturated carboxylic acid having a structure represented by formula (6), an esterification monomer having a structure represented by formula (7), and an unsaturated phosphate monomer having a structure represented by formula (8) to a free radical polymerization reaction, wherein the obtained product is a mother liquor of the high water-reducing polycarboxylate water-reducing agent;

[0016] In formula (5), R 11 is a C1-C5 alkylene group, R 12 、R 13 and R 14 Each is independently H, C1-C5 alkyl or -OH, and n is an integer from 0 to 100;

[0017] In formula (6), R 21 and R 22 Each independently represents H, C1-C5 alkyl or -R 23 -COOH and R 21 and R 22 At least one of them is -R 23 -COOH, R 23 does not exist or is a C1-C5 alkylene group; when R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 Able to bond into a ring; R 21 ` and R 22 `Each independently is H or C1-C5 alkyl;

[0018] In formula (7), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 ` does not exist or is a C1-C5 alkylene group, R 31`` is a C1-C5 alkyl group; R 32 R is absent or is a substituted or unsubstituted C1-C5 alkylene group; 33 、R 34 or R 35 Each is independently H or a C1-C5 alkyl group;

[0019] In formula (8), R 41 is O or methylene, R 42 、R 43 and R 44 Each is independently H or a C1-C5 alkyl group, and m, p and q are each independently an integer from 0 to 3.

[0020] The present invention also provides a high water-reducing polycarboxylate water-reducing agent prepared by the above method.

[0021] In addition, the present invention also provides the use of the high water-reducing polycarboxylate water-reducing agent in the field of construction.

[0022] The key to the present invention is to copolymerize an unsaturated polyether macromonomer having a structure shown in formula (5), an unsaturated carboxylic acid having a structure shown in formula (6), an esterification monomer having a structure shown in formula (7) and an unsaturated phosphate monomer having a structure shown in formula (8) to simultaneously introduce them into the polycarboxylic acid molecular chain, wherein the unsaturated double bond in the unsaturated polyether macromonomer is directly bonded to an oxygen atom and has a long polyoxyethylene ether chain segment, the esterification monomer simultaneously contains an unsaturated double bond, an ester group, at least one carboxyl group and an amino group, and the unsaturated phosphate monomer contains a phosphate group and the phosphate group is bonded to the unsaturated double bond via an oxygen atom or a short-chain alkylene group and has a short-chain alkoxy group. The synergistic combination of these specific structures can not only greatly improve the dispersibility of the polycarboxylic acid water-reducing agent, but also improve its water reduction rate, and has broad application prospects.

[0023] In a preferred embodiment, when the free radical polymerization method includes: S1, dissolving an unsaturated polyether macromonomer, an unsaturated phosphate monomer, an oxidant I and a reducing agent I in a solvent to obtain a substrate; S2, respectively dripping solution A, solution B, solution C and solution D into the substrate to carry out a free radical copolymerization reaction, wherein the solution A is a mixed solution of an unsaturated carboxylic acid and an esterified monomer, the solution B is an oxidant II solution, the solution C is a mixed solution of a chain transfer agent and a reducing agent II, and the solution D is a regulator solution, that is, when the oxidant and the reducing agent are added in a one-time addition and dropwise dual manner, the polymerization reaction of the vinyl ether polycarboxylic acid water reducer can be effectively regulated, and there is no need to invest in refrigeration equipment to control the initial reaction temperature below 20°C, and production can be achieved at room temperature. DETAILED DESCRIPTION

[0024] The high water-reducing polycarboxylate water-reducing agent provided by the present invention comprises a polyether structural unit, a carboxylic acid structural unit, an esterification structural unit and a phosphate structural unit. Wherein, the mass ratio of the polyether structural unit, the carboxylic acid structural unit, the esterification structural unit and the phosphate structural unit is preferably 180:(10-20):(4-10):(1-3). Based on the content of the polyether structural unit as 180 parts by weight, the content of the carboxylic acid structural unit is 10-20 parts by weight, such as 10, 12, 14, 16, 18, 20 parts by weight or any value therebetween; the content of the esterification structural unit is 4-10 parts by weight, such as 4, 6, 8, 10 parts by weight or any value therebetween; the content of the phosphate structural unit is 1-3 parts by weight, such as 1, 1.5, 2, 2.5, 3 parts by weight or any value therebetween.

[0025] In the present invention, the polyether structural unit has a structure shown in formula (1):

[0026] In formula (1), R 11 is a C1-C5 alkylene group, R 12 、R 13 and R 14 Each is independently H, C1-C5 alkyl or -OH, and n is an integer from 0 to 100. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene or neopentylene. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl or neopentyl. n can be 0, 1, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100 or any value therebetween. In a preferred embodiment, R 11 is a C1-C5 alkylene group, R 12 、R 13 and R 14 are H, and n is an integer from 20 to 80. The polyether structural unit is derived from an unsaturated polyether macromonomer, which may be ethylene glycol monovinyl polyethylene glycol ether (EPEG) and / or 4-hydroxybutyl vinyl polyoxyethylene ether (VPEG). Furthermore, the number average molecular weight of the unsaturated polyether macromonomer is preferably from 1200 to 6000, such as 1200, 1400, 1600, or any value therebetween.

[0027] In the present invention, the carboxylic acid structural unit has a structure shown in formula (2):

[0028] In formula (2), R21 and R 22 Each independently represents H, C1-C5 alkyl or -R 23 -COOH and R 21 and R 22 At least one of them is -R 23 -COOH, R 23 does not exist or is a C1-C5 alkylene group; when R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 Able to bond into a ring; R 21 ` and R 22 `Each independently represents H or a C1-C5 alkyl group. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene, or neopentylene. When R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 The carboxylic acid structural unit is formed by the polymerization of unsaturated carboxylic acids. Specific examples of the unsaturated carboxylic acids include, but are not limited to, at least one of acrylic acid, methacrylic acid, itaconic acid, and maleic anhydride.

[0029] In the present invention, the esterification structural unit has a structure shown in formula (3):

[0030] In formula (3), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 ` does not exist or is a C1-C5 alkylene group, R 31 `` is a C1-C5 alkyl group; R 32 R is absent or is a substituted or unsubstituted C1-C5 alkylene group; 33 、R 34 or R 35Each independently represents H or a C1-C5 alkyl group. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene, or neopentylene. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. In a preferred embodiment, R 31 -R 31 `OH, -R 31 `COOH or -R 31 `CONH2, R 31 `Preferably methylene or ethylene, at this time, is more conducive to the improvement of the dispersibility of the polycarboxylate water reducer

[0031] In the present invention, the phosphate structural unit has a structure shown in formula (4);

[0032] In formula (4), R 41 is O or methylene, R 42 、R 43 and R 44 Each is independently H or a C1-C5 alkyl group, and m, p and q are each independently an integer from 0 to 3. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl or neopentyl. m, p and q can be 0, 1, 2 or 3. In a preferred embodiment, R 41 is O or methylene, R 42 、R 43 and R 44 are all H, and m, p and q are integers of 1 to 2.

[0033] In the present invention, the highly water-reducing polycarboxylate water-reducing agent is preferably a zero-reduction copolymer.

[0034] In the present invention, the number average molecular weight of the high water-reducing polycarboxylate water-reducing agent is preferably 20,000 to 80,000, such as 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000 or any value therebetween.

[0035] The preparation method of the high water-reducing polycarboxylate water-reducing agent provided by the present invention comprises subjecting an unsaturated polyether macromonomer, an unsaturated carboxylic acid, an esterification monomer and an unsaturated phosphate ester monomer to a free radical polymerization reaction, and the obtained product is a high water-reducing polycarboxylate water-reducing agent mother liquor.

[0036] In a preferred embodiment, the method for the free radical polymerization reaction comprises: S1, dissolving an unsaturated polyether macromonomer, an unsaturated phosphate monomer, an oxidant I and a reducing agent I in a solvent to obtain a substrate; S2, dripping solution A, solution B, solution C and solution D into the substrate respectively to carry out a free radical copolymerization reaction, wherein solution A is a mixed solution of an unsaturated carboxylic acid and an esterified monomer, solution B is an oxidant II solution, solution C is a mixed solution of a chain transfer agent and a reducing agent II, and solution D is a regulator solution. At this time, the oxidant and the reducing agent are added in a dual manner of one-time addition and dropwise addition, so that the polymerization reaction of the vinyl ether polycarboxylate water-reducing agent can be effectively regulated, without the need for refrigeration equipment, and production at room temperature can be achieved. Wherein, the dripping time of solution A and solution B is preferably independently 40 to 70 minutes, such as 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes or any value therebetween. The dropwise addition time of solution C and solution D is preferably independently 50 to 80 min, such as 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min or any value therebetween.

[0037] The mass ratio of the unsaturated polyether macromonomer, the unsaturated carboxylic acid, the esterification monomer, and the unsaturated phosphate ester monomer is preferably 180:(10-20):(4-10):(1-3). Based on 180 parts by weight of the unsaturated polyether macromonomer, the unsaturated carboxylic acid content is preferably 10-20 parts by weight, such as 10, 12, 14, 16, 18, 20 parts by weight, or any value therebetween; the esterification monomer content is preferably 4-10 parts by weight, such as 4, 6, 8, 10 parts by weight, or any value therebetween; and the unsaturated phosphate ester monomer content is preferably 1-3 parts by weight, such as 1, 1.5, 2, 2.5, 3 parts by weight, or any value therebetween.

[0038] In the present invention, the unsaturated polyether macromonomer has a structure shown in formula (5):

[0039] In formula (5), R 11 is a C1-C5 alkylene group, R 12 、R 13 and R 14Each is independently H, C1-C5 alkyl or -OH, and n is an integer from 0 to 100. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene or neopentylene. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl or neopentyl. n can be 0, 1, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100 or any value therebetween. In a preferred embodiment, R 11 is a C1-C5 alkylene group, R 12 、R 13 and R 14 are all H, and n is an integer from 20 to 80. The unsaturated polyether macromonomer can be ethylene glycol monovinyl polyethylene glycol ether (EPEG) and / or 4-hydroxybutyl vinyl polyoxyethylene ether (VPEG). In addition, the number average molecular weight of the unsaturated polyether macromonomer is preferably 1200 to 6000, such as 1200, 1400, 1600 or any value therebetween.

[0040] In the present invention, the unsaturated carboxylic acid has a structure shown in formula (6):

[0041] In formula (6), R 21 and R 22 Each independently represents H, C1-C5 alkyl or -R 23 -COOH and R 21 and R 22 At least one of them is -R 23 -COOH, R 23 does not exist or is a C1-C5 alkylene group; when R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 Able to bond into a ring; R 21 ` and R 22 `Each independently represents H or a C1-C5 alkyl group. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene, or neopentylene. When R 21 and R22 All are -R 23 -COOH, R 21 and R 22 The unsaturated carboxylic acid can be bonded to form a ring, in which case an acid anhydride is formed. In view of the availability of raw materials, the unsaturated carboxylic acid is particularly preferably selected from at least one of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride.

[0042] In the present invention, the esterification monomer has a structure shown in formula (7):

[0043] In formula (7), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 ` does not exist or is a C1-C5 alkylene group, R 31 `` is a C1-C5 alkyl group; R 32 R is absent or is a substituted or unsubstituted C1-C5 alkylene group; 33 、R 34 or R 35 Each independently represents H or a C1-C5 alkyl group. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene, or neopentylene. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. In a preferred embodiment, R 31 -R 31 `OH, -R 31 `COOH or -R 31 `CONH2, R 31 `Preferably methylene or ethylene, at this time, is more conducive to the improvement of the dispersibility and water reduction rate of the polycarboxylate water reducer.

[0044] In the present invention, the esterification monomer can be obtained commercially or prepared according to various methods in the art. In one embodiment, the esterification monomer is prepared according to the following method: a polycarboxylic acid monomer having a structure represented by formula (9) and an unsaturated alcohol represented by formula (10) are subjected to a condensation reaction in the presence of a catalyst and a polymerization inhibitor;

[0045] In formula (9), R 31 is H, C1-C5 alkyl, -R31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 ` does not exist or is a C1-C5 alkylene group, R 31 `` is a C1-C5 alkyl group;

[0046] In formula (10), R 32 R is absent or is a substituted or unsubstituted C1-C5 alkylene group; 33 、R 34 or R 35 Each is independently H or a C1-C5 alkyl group.

[0047] In the preparation process of the above esterification monomer, R 31 Preferably -R 31 `OH, -R 31 `COOH or -R 31 `CONH2, R 31 `Preferably methylene or ethylene, at this time, is more conducive to the improvement of the dispersibility and alkaline water performance of the polycarboxylate water reducer.

[0048] In the preparation process of the above-mentioned esterification monomer, specific examples of the unsaturated alcohol include but are not limited to: at least one of 2-methyl-3-butene-1-ol, 2-methyl-2-propene-1-ol and 2-methoxy-3-butene-1-ol.

[0049] In the preparation process of the esterification monomer, the molar ratio of the polycarboxylic acid monomer to the unsaturated alcohol is preferably 1:(0.9-1.1), such as 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1 or any value therebetween.

[0050] In the preparation process of the above-mentioned esterification monomer, the conditions of the condensation reaction preferably include a temperature of 90-100°C, such as 90°C, 92°C, 94°C, 96°C, 98°C, 100°C or any value therebetween; and a time of 3-4h, such as 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h or any value therebetween.

[0051] In the preparation process of the esterification monomer, the catalyst may be, for example, benzenesulfonic acid. The amount of the catalyst used is preferably 0.1 to 2 wt% of the total amount of the polycarboxylic acid monomer and the unsaturated alcohol, such as 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt% or any value therebetween.

[0052] In the preparation process of the esterification monomer, the polymerization inhibitor may be, for example, hydroquinone. The amount of the polymerization inhibitor used is preferably 0.2-2 wt% of the total amount of the polycarboxylic acid monomer and the unsaturated alcohol, such as 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt% or any value therebetween.

[0053] In the present invention, the unsaturated phosphate monomer has a structure shown in formula (8):

[0054] In formula (8), R 41 is O or methylene, R 42 、R 43 and R 44 Each is independently H or a C1-C5 alkyl group, and m, p and q are each independently an integer from 0 to 3. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl or neopentyl. m, p and q can be 0, 1, 2 or 3. In a preferred embodiment, R 41 is O or methylene, R 42 、R 43 and R 44 are all H, and m, p and q are integers of 1 to 2.

[0055] In the preparation process of the above-mentioned high-water-reducing polycarboxylate water-reducing agent, the types of oxidant I and oxidant II can be the same or different, and can each be independently selected from at least one of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, cumene hydroperoxide, dibenzoyl peroxide, and tert-butyl peroxide, preferably a mixture of two or more. The types of reducing agent I and reducing agent II can be the same or different, and can each be independently selected from at least one of L-ascorbic acid, azobisisopropylimidazoline hydrochloride, azobiscyclohexylcarbonitrile, sodium bisulfite, sodium sulfite, sodium metabisulfite, bleaching agent, ferrous sulfate heptahydrate, sodium hypophosphite, sodium phosphite, and ferrous ammonium sulfate, preferably a mixture of two or more. The total amount of oxidant I and oxidant II is preferably 0.3% to 3.0% of the total mass of the unsaturated polyether macromonomer, such as 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or any value therebetween. The weight ratio of the oxidizing agent I to the oxidizing agent II is preferably (0.2-1.5):1, such as 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1.0:1, 1.2:1, 1.4:1, 1.5:1, or any value therebetween. The total amount of the reducing agent I and the reducing agent II is preferably 0.3%-3.0% of the total mass of the unsaturated polyether macromonomer, such as 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or any value therebetween. The weight ratio of the reducing agent I to the reducing agent II is preferably (0.001-1.2):1, such as 0.001:1, 0.005:1, 0.01:1, 0.05:1, 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1.0:1, 1.2:1, or any value therebetween. Among them, "Ⅰ" and "Ⅱ" are only used to distinguish different oxidants or reducing agents for the convenience of description and have no other special meanings.

[0056] In the preparation of the highly water-reducing polycarboxylate water-reducing agent, the chain transfer agent is preferably a mercaptan chain transfer agent, more preferably at least one selected from the group consisting of thioglycolic acid, mercaptopropionic acid, mercaptoethanol, and mercaptopropanol. Furthermore, the amount of the chain transfer agent used is preferably 0.1 to 2.0% of the total mass of the unsaturated polyether macromonomer, unsaturated carboxylic acid, esterification monomer, and unsaturated phosphate ester monomer, such as 0.1%, 0.3%, 0.5%, 1%, 1.5%, 2%, or any value therebetween.

[0057] In the preparation of the highly water-reducing polycarboxylate water-reducing agent, specific examples of the regulator include, but are not limited to, at least one of trisodium phosphate, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, triethanolamine, diethanol monoisopropanolamine, diisopropanol monoethanolamine, triisopropanolamine, tetraethanol ethylenediamine, and tetraisopropanol ethylenediamine. Furthermore, the regulator is used in an amount of 0.3% to 3.0% of the total mass of the unsaturated polyether macromonomer, such as 0.3%, 0.6%, 1%, 1.5%, 2%, 2.5%, 3%, or any value therebetween.

[0058] In the preparation process of the above-mentioned high water-reducing polycarboxylate water-reducing agent, the conditions of the free radical copolymerization reaction preferably include the initial dropwise addition temperature is preferably 20 to 40°C, such as 20°C, 25°C, 30°C, 35°C, 40°C or any value therebetween; the reaction time after the solution is added dropwise is preferably 0.5 to 1h, such as 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h or any value therebetween.

[0059] The present invention also provides a high water-reducing polycarboxylate water-reducing agent prepared by the above method.

[0060] In addition, the present invention also provides the use of the high water-reducing polycarboxylate water-reducing agent in the field of construction.

[0061] The present invention will be described in detail below through examples.

[0062] Preparation Example 1 This preparation example is used to illustrate the preparation of the esterification monomer provided by the present invention.

[0063] 72.0 g of polycarboxylic acid monomer (having the structure shown in formula (9), R 31 (-CH2CH2OH), 35.0g of 2-methyl-3-butene-1-ol and 1.4g of hydroquinone were added into the reaction vessel and mixed evenly. Under nitrogen protection, 2.3g of benzenesulfonic acid was added, and the system temperature was adjusted to 90°C for 4h. After the reaction was completed, it was cooled to room temperature to obtain the esterified monomer.

[0064] Preparation Example 2 This preparation example is used to illustrate the preparation of the esterification monomer provided by the present invention.

[0065] 72.0 g of polycarboxylic acid monomer (having the structure shown in formula (9), R 31 -CH2CONH2), 32.6g of 2-methyl-3-butene-1-ol and 1.1g of hydroquinone were added to a reaction container and mixed. Under nitrogen protection, 2.0g of benzenesulfonic acid was added, and the system temperature was adjusted to 100°C for reaction for 3h. After the reaction was completed, it was cooled to room temperature to obtain an esterified monomer.

[0066] Preparation Example 3 This preparation example is used to illustrate the preparation of the esterification monomer provided by the present invention.

[0067] 72.0 g of polycarboxylic acid monomer (having the structure shown in formula (9), R 31 -H), 46.60g of 2-methyl-3-butene-1-ol and 1.8g of hydroquinone were added to the reaction vessel and mixed evenly. Under nitrogen protection, 2.9g of benzenesulfonic acid was added, and the system temperature was adjusted to 90°C for 4h. After the reaction was completed, it was cooled to room temperature to obtain an esterified monomer.

[0068] Example 1

[0069] S1, 180g of ethylene glycol monovinyl polyglycol ether with a number average molecular weight of 3000, 2.0g of unsaturated phosphate monomer (having the structure shown in formula (8), R 41 O, R 42 、R 43 and R 44 is H, m, p and q are 1), 0.7 g of hydrogen peroxide, 0.8 g of sodium hypophosphite, 0.001 g of ferrous sulfate and 120 g of deionized water were added to a reaction container and mixed to obtain a substrate;

[0070] S2. Solution A (a mixed solution of 6 g of the esterified monomer obtained in Preparation Example 1, 13.0 g of acrylic acid, 2.0 g of methacrylic acid and 10.0 g of water), solution B (a mixed solution of 0.5 g of hydrogen peroxide, 0.5 g of dibenzoyl peroxide and 10.0 g of water), solution C (a mixed solution of 0.20 g of ascorbic acid, 0.3 g of mercaptopropionic acid and 20.0 g of water), and solution D (a mixed solution of 1.0 g of trisodium phosphate, 1.0 g of triethanolamine and 20 g of water) were respectively added dropwise to the reaction vessel to react. The initial reaction temperature was 30 ° C. The dropwise addition time of AB solution was 50 min, and the dropwise addition time of CD solution was 60 min. After the dropwise addition was completed, the temperature was kept warm for 1 h. After the insulation was completed, the temperature was cooled to room temperature to obtain a high water-reducing polycarboxylate water-reducing agent mother liquor.

[0071] Example 2

[0072] S1, 180g of 4-hydroxybutyl vinyl polyoxyethylene ether with a number average molecular weight of 3000, 3.0g of unsaturated phosphate monomer (having the structure shown in formula (8), R 41 is methylene, R 42 、R 43 and R 44 is H, m, p and q are 1), 1.0 g of hydrogen peroxide, 0.002 g of ferrous sulfate and 150 g of deionized water were added to a reaction container and mixed to obtain a substrate;

[0073] S2. Solution A (a mixed solution of 7 g of the esterified monomer obtained in Preparation Example 1, 12.0 g of acrylic acid and 10.0 g of water), solution B (a mixed solution of 1.0 g of isopropylbenzene hydroperoxide and 10.0 g of water), solution C (a mixed solution of 0.20 g of ascorbic acid, 0.5 g of sodium hypophosphite, 0.5 g of mercaptopropionic acid and 20.0 g of water), and solution D (a mixed solution of 1.0 g of trisodium phosphate, 0.5 g of sodium hydroxide and 20 g of water) were respectively added dropwise to the reaction vessel to react. The initial reaction temperature was 25 ° C. The dropwise addition time of AB solution was 50 min, and the dropwise addition time of CD solution was 60 min. After the dropwise addition was completed, the temperature was kept warm for 1 h. After the insulation was completed, the temperature was cooled to room temperature to obtain a high water-reducing polycarboxylate water-reducing agent mother liquor.

[0074] Example 3

[0075] S1, 180g of ethylene glycol monovinyl polyglycol ether with a number average molecular weight of 3000, 2.0g of unsaturated phosphate monomer (having the structure shown in formula (8), R 41 is methylene, R 42 、R 43 and R 44 is H, m, p and q are 1), 0.5 g of hydrogen peroxide, 150 g of deionized water, 0.7 g of sodium hypophosphite, and 0.002 g of ferrous sulfate were added to a reaction container and mixed to obtain a substrate;

[0076] S2. Solution A (a mixed solution of 8 g of the esterified monomer obtained in Preparation Example 2, 13.0 g of acrylic acid, 2.0 g of methacrylic acid, and 10.0 g of water), solution B (a mixed solution of 0.8 g of hydrogen peroxide, 1.0 g of potassium persulfate, and 10.0 g of water), solution C (a mixed solution of 0.5 g of sodium bisulfite, 0.15 g of bleaching powder, 0.3 g of mercaptopropionic acid, and 20.0 g of water), and solution D (a mixed solution of 1.5 g of trisodium phosphate, 1.5 g of diethanol monoisopropanolamine, and 20 g of water) were respectively added dropwise to the reaction vessel to react, the initial reaction temperature was 40 ° C, the AB solution was added dropwise for 40 min, the CD solution was added dropwise for 50 min, and the mixture was kept warm for 1 h after the addition was completed. After the insulation was completed, the mixture was cooled to room temperature to obtain a high water-reducing polycarboxylate water-reducing agent mother liquor.

[0077] Example 4

[0078] S1, 180g of ethylene glycol monovinyl polyglycol ether with a number average molecular weight of 3000, 2.0g of unsaturated phosphate monomer (having the structure shown in formula (8), R 41 O, R 42 、R 43 and R 44 is H, m, p and q are 1), 0.5 g of hydrogen peroxide, 0.7 g of sodium hypophosphite and 150 g of deionized water were added to a reaction container and mixed to obtain a substrate;

[0079] S2. Solution A (a mixed solution of 6 g of the esterified monomer obtained in Preparation Example 3, 15.0 g of acrylic acid, and 10.0 g of water), solution B (a mixed solution of 1.2 g of hydrogen peroxide and 10.0 g of water), solution C (a mixed solution of 0.40 g of sodium metabisulfite, 0.2 g of bleaching powder, 0.5 g of mercaptopropionic acid, and 20.0 g of water), and solution D (a mixed solution of 0.3 g of trisodium phosphate, 0.5 g of diethanol monoisopropanolamine, and 20 g of water) were respectively added dropwise to the reaction vessel to react, the initial reaction temperature was 20 ° C, the AB solution was added dropwise for 70 min, the CD solution was added dropwise for 80 min, and the temperature was kept warm for 1 h after the addition was completed. After the insulation was completed, the temperature was cooled to room temperature to obtain a high water-reducing polycarboxylate water-reducing agent mother liquor.

[0080] Example 5

[0081] A highly water-reducing polycarboxylate water-reducing agent was prepared according to the method of Example 1, except that the oxidant was added to the substrate at one time. The other conditions were the same as those of Example 1. The specific steps were as follows:

[0082] S1, 180g of ethylene glycol monovinyl polyglycol ether with a number average molecular weight of 3000, 2.0g of unsaturated phosphate monomer (having the structure shown in formula (8), R 41 O, R 42 、R 43 and R 44 is H, m, p and q are 1), 1.2 g of hydrogen peroxide, 0.8 g of sodium hypophosphite, 0.001 g of ferrous sulfate, 0.5 g of dibenzoyl peroxide and 130 g of deionized water were added to a reaction container and mixed to obtain a substrate;

[0083] S2. Solution A (a mixed solution of 6 g of the esterified monomer obtained in Preparation Example 1, 13.0 g of acrylic acid, 2.0 g of methacrylic acid and 10.0 g of water), solution C (a mixed solution of 0.20 g of ascorbic acid, 0.3 g of mercaptopropionic acid and 20.0 g of water), and solution D (a mixed solution of 1.0 g of trisodium phosphate, 1.0 g of triethanolamine and 20 g of water) were respectively added dropwise to the reaction vessel to react. The system needed to be refrigerated to control the initial reaction temperature at 18°C. The dropwise addition time of solution A was 50 min, and the dropwise addition time of solution CD was 60 min. After the dropwise addition was completed, the temperature was kept warm for 1 h. After the insulation was completed, the temperature was cooled to room temperature to obtain a high water-reducing polycarboxylate water-reducing agent mother liquor.

[0084] Comparative Example 1

[0085] A high water-reducing polycarboxylate water-reducing agent was prepared according to the method of Example 1, except that no esterified monomer was added. The other conditions were the same as in Example 1 to obtain a reference high water-reducing polycarboxylate water-reducing agent mother liquor.

[0086] Comparative Example 2

[0087] A high water-reducing polycarboxylate water-reducing agent was prepared according to the method of Example 1, except that no unsaturated phosphate monomer was added. The other conditions were the same as in Example 1 to obtain a reference high water-reducing polycarboxylate water-reducing agent mother liquor.

[0088] Comparative Example 3

[0089] S1, 150g of 3000 number average molecular weight ethylene glycol monovinyl polyethylene glycol ether, 5g of triisopropanolamine, 3.3g of potassium bicarbonate and 57g of water were added to a reaction vessel and mixed to obtain a substrate;

[0090] S2. Solution A (a mixed solution of 15.0 g of acrylic acid, 3.0 g of triisopropanolamine and 10.0 g of water) and solution B (a mixed solution of 1.5 g of potassium persulfate and 10.0 g of water) were respectively added dropwise into the reaction vessel to react. The initial reaction temperature was 30° C., the dropping time of AB solution was 50 min, and the mixture was kept warm for 1 h after the addition was completed. After the insulation was completed, the mixture was cooled to room temperature to obtain a reference high water-reducing polycarboxylate water-reducing agent mother liquor.

[0091] Test Case

[0092] Concrete was prepared according to the mix ratio in Table 1. The mother liquor obtained in the above examples and comparative examples was diluted to a 10% solid water-reducing agent dilution solution before concrete testing. The water-reducing agent dilution solution was added at a dosage of 1.8%. The performance indicators were then tested according to GB / T 50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures". The results are shown in Table 2.

[0093] Table 1 (parts by weight)

[0094] Table 2

[0095] The results in Table 2 show that, on the one hand, the 0h and 1h slump and spread values ​​of the polycarboxylate water-reducers obtained in each example are higher than those of the comparative example, indicating that the polycarboxylate water-reducers obtained in each of the above examples have good dispersibility. On the other hand, the flow rate of the polycarboxylate water-reducers obtained in each example is relatively fast, indicating that the polycarboxylate water-reducers obtained in each of the above examples have high water reduction rates. In addition, a comparison of Example 1 with Comparative Examples 1-3 shows that when no esterified monomer and / or unsaturated phosphate ester monomer is added, the dispersibility of the resulting polycarboxylate water-reducers is poor, and the water reduction rate may also be affected.

[0096] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A high water-reducing polycarboxylate water-reducing agent, characterized in that: The highly water-reducing polycarboxylate water-reducing agent comprises a polyether structural unit, a carboxylic acid structural unit, an esterification structural unit and a phosphate structural unit, wherein the polyether structural unit has a structure as shown in formula (1), the carboxylic acid structural unit has a structure as shown in formula (2), the esterification structural unit has a structure as shown in formula (3), and the phosphate structural unit has a structure as shown in formula (4); In formula (1), R 11 is a C1-C5 alkylene group, R 12 , R 13 and R 14 Each is independently H, C1-C5 alkyl or -OH, and n is an integer from 0 to 100; In formula (2), R 21 and R 22 Each independently represents H, C1-C5 alkyl or -R 23 -COOH and R 21 and R 22 At least one of them is -R 23 -COOH, R 23 does not exist or is a C1-C5 alkylene group; when R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 Able to bond into a ring; R 21 ` and R 22 `Each independently is H or a C1-C5 alkyl group; In formula (3), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 `Not present or C1-C5 alkylene, R 31 `` is a C1-C5 alkyl group; R 32 R is absent or is substituted or unsubstituted C1-C5 alkylene; 33 , R 34 or R 35 Each is independently H or a C1-C5 alkyl group; In formula (4), R 41 is O or methylene, R 42 , R 43 and R 44 Each is independently H or a C1-C5 alkyl group, and m, p and q are each independently an integer of 0 to 3.

2. The high water-reducing polycarboxylate water-reducing agent according to claim 1, characterized in that: The mass ratio of the polyether structural unit, the carboxylic acid structural unit, the esterification structural unit and the phosphate structural unit is 180:(10-20):(4-10):(1-3).

3. The high water-reducing polycarboxylate water-reducing agent according to claim 1, characterized in that: The high water-reducing polycarboxylate water-reducing agent is a random copolymer; preferably, the high water-reducing polycarboxylate water-reducing agent has a number average molecular weight of 20,000 to 80,000.

4. A method for preparing a high water-reducing polycarboxylate water-reducing agent, characterized in that: The method comprises: subjecting an unsaturated polyether macromonomer having a structure shown in formula (5), an unsaturated carboxylic acid having a structure shown in formula (6), an esterification monomer having a structure shown in formula (7) and an unsaturated phosphate monomer having a structure shown in formula (8) to a free radical polymerization reaction, wherein the obtained product is a high water-reducing polycarboxylic acid water-reducing agent mother liquor; In formula (5), R 11 is a C1-C5 alkylene group, R 12 , R 13 and R 14 Each is independently H, C1-C5 alkyl or -OH, and n is an integer from 0 to 100; In formula (6), R 21 and R 22 Each independently represents H, C1-C5 alkyl or -R 23 -COOH and R 21 and R 22 At least one of them is -R 23 -COOH, R 23 does not exist or is a C1-C5 alkylene group; when R 21 and R 22 All are -R 23 -COOH, R 21 and R 22 Able to bond into a ring; R 21 ` and R 22 `Each independently is H or a C1-C5 alkyl group; In formula (7), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 `Not present or C1-C5 alkylene, R 31 `` is a C1-C5 alkyl group; R 32 R is absent or is substituted or unsubstituted C1-C5 alkylene; 33 , R 34 or R 35 Each is independently H or a C1-C5 alkyl group; In formula (8), R 41 is O or methylene, R 42 , R 43 and R 44 Each is independently H or a C1-C5 alkyl group, and m, p and q are each independently an integer of 0 to 3.

5. The method for preparing a highly water-reducing polycarboxylate water-reducing agent according to claim 4, characterized in that: The free radical polymerization method comprises: S1, dissolving an unsaturated polyether macromonomer, an unsaturated phosphate monomer, an oxidizing agent I and a reducing agent I in a solvent to obtain a substrate; S2. Solution A, solution B, solution C and solution D are respectively dropped into the substrate to carry out free radical copolymerization reaction, wherein solution A is a mixed solution of unsaturated carboxylic acid and esterification monomer, solution B is an oxidant II solution, solution C is a mixed solution of chain transfer agent and reducing agent II, and solution D is a regulator solution.

6. The method for preparing the highly water-reducing polycarboxylate water-reducing agent according to claim 4, characterized in that: The mass ratio of the unsaturated polyether macromonomer, the unsaturated carboxylic acid, the esterification monomer and the unsaturated phosphate ester monomer is 180:(10-20):(4-10):(1-3).

7. The method for preparing the highly water-reducing polycarboxylate water-reducing agent according to claim 4, characterized in that: The unsaturated polyether macromonomer is ethylene glycol monovinyl polyethylene glycol ether and / or 4-hydroxybutyl vinyl polyoxyethylene ether; the number average molecular weight of the unsaturated polyether macromonomer is 1200-6000.

8. The method for preparing the highly water-reducing polycarboxylate water-reducing agent according to claim 4, characterized in that: The unsaturated carboxylic acid is at least one selected from acrylic acid, methacrylic acid, itaconic acid and maleic anhydride.

9. The method for preparing the highly water-reducing polycarboxylate water-reducing agent according to claim 4, characterized in that: The esterification monomer is prepared by the following method: a polycarboxylic acid monomer having a structure represented by formula (9) and an unsaturated alcohol represented by formula (10) are subjected to a condensation reaction in the presence of a catalyst and an inhibitor; In formula (9), R 31 is H, C1-C5 alkyl, -R 31 `OH, -R 31 `COOH, -R 31 `CONH2 or -R 31 `OR 31 ``, R 31 `Not present or C1-C5 alkylene, R 31 `` is a C1-C5 alkyl group; In formula (10), R 32 R is absent or is substituted or unsubstituted C1-C5 alkylene; 33 , R 34 or R 35 Each is independently H or a C1-C5 alkyl group; Preferably, the molar ratio of the polycarboxylic acid monomer to the unsaturated alcohol is 1:(0.9-1.1); Preferably, the conditions of the condensation reaction include a temperature of 90 to 100° C. and a time of 3 to 4 h; Preferably, the unsaturated alcohol is selected from at least one of 2-methyl-3-butene-1-ol, 2-methyl-2-propene-1-ol and 2-methoxy-3-butene-1-ol.

10. The method for preparing the highly water-reducing polycarboxylate water-reducing agent according to claim 5, characterized in that: The oxidant I and the oxidant II are each independently selected from at least one of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, cumene hydroperoxide, dibenzoyl peroxide and tert-butyl peroxide; Preferably, the reducing agent I and the reducing agent II are each independently selected from at least one of L-ascorbic acid, azobisisopropylimidazoline hydrochloride, azobiscyclohexylcarbonitrile, sodium bisulfite, sodium sulfite, sodium pyrosulfite, bleaching agent, ferrous sulfate heptahydrate, sodium hypophosphite, sodium phosphite and ammonium ferrous sulfate; Preferably, the chain transfer agent is a mercaptan chain transfer agent, more preferably at least one selected from thioglycolic acid, mercaptopropionic acid, mercaptoethanol and mercaptopropanol; Preferably, the regulator is selected from at least one of trisodium phosphate, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, triethanolamine, diethanol monoisopropanolamine, diisopropanol monoethanolamine, triisopropanolamine, tetraethanol ethylenediamine and tetraisopropanol ethylenediamine; Preferably, the total amount of the oxidant and oxidant II is 0.3% to 3.0% of the total mass of the unsaturated polyether macromonomer; Preferably, the total amount of reducing agent I and reducing agent II is 0.3% to 3.0% of the total mass of the unsaturated polyether macromonomer; Preferably, the amount of the chain transfer agent is 0.1 to 2.0% of the total mass of the unsaturated polyether macromonomer, the unsaturated carboxylic acid, the esterification monomer and the unsaturated phosphate ester monomer; Preferably, the amount of the regulator is 0.3% to 3.0% of the total mass of the unsaturated polyether macromonomer; Preferably, the dropwise addition time of the solution A and the solution B is independently 40 to 70 minutes; Preferably, the dropping time of the C solution and the D solution is independently 50 to 80 minutes; Preferably, the conditions of the free radical copolymerization reaction include an initial dropwise addition temperature of 20 to 40° C. and a reaction time of 0.5 to 1 h after the solution is added dropwise.

11. A highly water-reducing polycarboxylate water-reducing agent prepared by the method according to any one of claims 4 to 10.

12. Use of the highly water-reducing polycarboxylate water-reducing agent according to any one of claims 1 to 3 and 11 in the field of construction.

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