A novel polycarboxylic acid collapse-preventing agent and preparation method thereof

Abstract

The present invention relates to a novel polycarboxylic acid collapse retaining agent and a preparation method thereof, wherein the novel polycarboxylic acid collapse retaining agent is generated by polymerization reaction of compound A, compound B, unsaturated macromonomer, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, and unsaturated carboxylic acid ester under the action of an initiator and a molecular weight regulator; the mass ratio of the unsaturated macromonomer, compound A, compound B, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, and unsaturated carboxylic acid ester is 180:(1-5):(1-10):(5-30):(10-40). The present invention introduces compound A into the molecular structure of the polycarboxylic acid collapse retaining agent through copolymerization reaction, so that the main chain side group has a benzene ring and a carboxyl group or a sulfonic acid group, and the carboxyl group or the sulfonic acid group provides an electrostatic repulsion, thereby enhancing the initial water-reducing effect; the benzene ring makes the obtained polycarboxylic acid collapse retaining agent molecule more stretched after being adsorbed on the surface of cement particles, the steric hindrance effect is more obvious, and it is more difficult to form intercalation adsorption with mud, so that the collapse retaining and mud resistance performance of the product are more excellent.

Description

Technical Field

[0001] The invention relates to the field of admixtures, and in particular to a novel polycarboxylic acid collapse-preventing agent and a preparation method thereof. Background Art

[0002] Polycarboxylic acid collapse preventer has the characteristics of good collapse prevention, strong performance designability, and convenient production. In addition, polycarboxylic acid collapse preventer does not produce harmful substances such as formaldehyde and ammonia during the synthesis and production process, and can be synthesized without heat source. The production process is energy-saving and environmentally friendly. Due to the energy-saving and environmentally friendly production process of polycarboxylic acid collapse preventer, it has been vigorously promoted and applied in the past decade. It has become an important component of polycarboxylic acid admixtures and is widely used in engineering fields such as roads, railways, bridges, nuclear power, dams, tunnels, marine engineering and high-rise buildings.

[0003] The problem of insufficient collapse prevention of polycarboxylic acid collapse inhibitors used in concrete is becoming increasingly prominent. Therefore, it is necessary to continuously improve the structure of polycarboxylic acid collapse inhibitors to make them have higher collapse prevention performance, which is the development direction of the polycarboxylic acid collapse inhibitor industry. Summary of the invention

[0004] In view of the prior art, the present invention develops a novel polycarboxylic acid collapse-preventing agent and a preparation method thereof, which can use a relatively convenient process method to prepare a high-performance polycarboxylic acid collapse-preventing agent with excellent collapse-preventing effect.

[0005] Based on this, the present invention provides a novel polycarboxylic acid collapse-preventing agent, which is generated by a polymerization reaction of compound A, compound B, unsaturated macromonomer, unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, and unsaturated carboxylic acid ester under the action of an initiator and a molecular weight regulator;

[0006] The structural formula of the compound A is as follows:

[0007]

[0008] Wherein, R1 is an alkylene group with 0-4 carbon atoms, R2 is COOM or SO3M or PO3M2, and M is H or an alkylene group with 0-4 carbon atoms or Na, K, or NH4;

[0009] The structural formula of the compound B is as follows:

[0010]

[0011] Wherein, R3 is H or CH3, R4 is an alkylene group of 0-4 carbon atoms, X is O or S, R5 is an alkylene group of 0-4 carbon atoms, R6 is an alkylene group of 0-4 carbon atoms, R7 is COOM or SO3M or PO3M2 or SO2NH2, and M is H or an alkylene group of 0-4 carbon atoms or Na, K, or NH4;

[0012] The unsaturated carboxylic acid ester is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-propylene glycol diacrylate, 1,5-pentanediol dimethacrylate, glycerol 1,3-dimethacrylate, glycidyl acrylate, glycidyl methacrylate, and 4-hydroxybutyl acrylate glycidyl ether.

[0013] Furthermore, the mass ratio of the unsaturated macromonomer, compound A, compound B, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, and unsaturated carboxylic ester is 180:(1-5):(1-10):(5-30):(10-40).

[0014] Further, the compound A is at least one of (4-vinylphenyl)methanesulfonic acid, sodium (4-vinylphenyl)methanesulfonate, 4-vinylphenylacetic acid, 4-vinylbenzoic acid, 2-methyl-2-(4-vinylphenyl)propionic acid, 4-vinyl-benzoic acid methyl ester, 4-vinyl-benzoic acid ethyl ester, 4-vinylphenylethyl ester, and 4-vinylphenyl diethyl phosphate.

[0015] Further, the compound B is at least one of 4-vinyloxybenzenesulfonic acid, 4-vinyloxybenzoic acid, 4-vinyloxyphenylacetic acid, sodium 4-vinyloxybenzenesulfonate, potassium 4-vinyloxybenzenesulfonate, methyl 4-vinyloxybenzoate, ethyl 4-vinyloxybenzoate, methyl 4-vinyloxyphenylacetate, ethyl 4-vinyloxyphenylacetate, 4-(allyloxy)benzenesulfonamide, 4-(vinyloxy)benzenesulfonamide, 2-(vinyloxy)benzenesulfonamide, and 4-(allyloxy)benzoic acid.

[0016] Furthermore, the molecular weight of the unsaturated macromonomer is 600-6000, and the unsaturated macromonomer is at least one of 3-methyl-3-butene-1-polyethylene glycol, 2-methylallyl polyethylene glycol, ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutyl vinyl polyoxyethylene ether, methoxy polyethylene glycol methacrylate, and methoxy polyethylene glycol acrylate.

[0017] Furthermore, the unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is at least one of acrylic acid, methacrylic acid and maleic anhydride.

[0018] Furthermore, the amount of the initiator is 0.5-3.0% of the total mass of the reactants; the amount of the molecular weight regulator is 0.2-3.0% of the total mass of the reactants.

[0019] Furthermore, the initiator includes a water-soluble redox initiator system or a water-soluble peroxide initiator system reagent.

[0020] Furthermore, the initiator is at least one of hydrogen peroxide-ascorbic acid, hydrogen peroxide-bleaching powder, hydrogen peroxide-ascorbic acid-ferrous sulfate, hydrogen peroxide-bleaching powder-ferrous sulfate, hydrogen peroxide-BRUGGOLITE E51-ferrous sulfate, and ammonium persulfate.

[0021] Furthermore, the molecular weight regulator includes at least one of thioglycolic acid, mercaptoethanol, mercaptopropionic acid, sulfonated mercaptopropionic acid, and sodium hypophosphite.

[0022] Another object of the present invention is to provide a method for preparing the novel polycarboxylic acid collapse-preventing agent, comprising at least the following steps:

[0023] The unsaturated macromonomer, compound A, compound B and water are added into a reactor and stirred. After the materials are evenly mixed, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, unsaturated carboxylic ester, initiator and molecular weight regulator are added dropwise. The dropping time is 0.5-2h, the initial reaction temperature is 10-25°C, and the material temperature is controlled at 10-30°C during the dropping process. After the dropping is completed, the temperature is kept at 0.5-1h to obtain a copolymer product. In the copolymer product, a base is added to adjust the pH value of the product to 5-7 or no base is added to adjust the pH value, so as to obtain the novel polycarboxylic acid collapse retaining agent.

[0024] In summary, the present invention has the following beneficial effects:

[0025] 1. The present invention introduces compound A into the molecular structure of the polycarboxylic acid slump retaining agent through copolymerization, so that the main chain side group has a benzene ring and a carboxyl group or a sulfonic acid group. The carboxyl group or the sulfonic acid group provides electrostatic repulsion and enhances the initial water-reducing effect. The benzene ring makes the side chain of the obtained polycarboxylic acid slump retaining agent molecule more stretched after being adsorbed on the surface of cement particles, the steric hindrance effect is more obvious, and it is less likely to form intercalation adsorption with mud, so that the product has better slump retaining and anti-mud performance.

[0026] 2. The ester monomers and unsaturated carboxylic acid esters in compound A and compound B of the present invention are introduced into the molecular structure of the polycarboxylic acid collapse inhibitor through copolymerization, so that after the obtained polycarboxylic acid collapse inhibitor is added to the alkaline concrete system, it will gradually hydrolyze to produce carboxylic acid, sulfonic acid and phosphoric acid groups, so that the product has excellent collapse-preventing performance.

[0027] 3. The present invention also uses other different types of macromonomers to match different types of small monomers, which is more conducive to copolymerization and also makes the performance of the final product more excellent.

[0028] 4. The raw materials used in the present invention are widely available and the preparation process is simple, so that the prepared product is more in line with the application requirements of the polycarboxylic acid collapse-preventing agent. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials and reagents used in the following examples are commercially available unless otherwise specified. The quantitative tests in the following examples were repeated three times, and the data are the average or average ± standard deviation of the three repeated experiments.

[0031] In addition, the "and / or" in the full text includes three solutions. Taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention. Example 1

[0032] (1) 180.00 g of 3000 molecular weight ethylene glycol monovinyl polyethylene glycol ether, 2.00 g of 4-vinyl-methyl benzoate, 4.00 g of 4-vinyloxybenzenesulfonic acid, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were mixed evenly, a mixed aqueous solution of acrylic acid and hydroxyethyl acrylate (including 7.00 g of acrylic acid, 20.00 g of hydroxyethyl acrylate and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including BRUGGOLITE E51 0.25g, water 20.00g), the initial reaction temperature is 15°C, the dropping time is 1.0h, the material temperature is controlled to be ≤30°C during the dropping process, and the temperature is kept for 1h after the dropping is completed to obtain a copolymer product;

[0033] (2) Add 3 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain a novel polycarboxylic acid collapse-preventing agent KZJ-1. Example 2

[0034] (1) 180.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 3000, 2.00 g of sodium (4-vinylphenyl) methanesulfonate, and 2.00 g of 4-(vinyloxy)benzenesulfonamide, 1.00g ethylene glycol diacrylate, 0.005g ferrous sulfate and 145.00g water were added to the reactor, and the agitator and temperature control device were turned on. After the materials were evenly mixed, a mixed aqueous solution of acrylic acid, hydroxyethyl acrylate and hydroxypropyl acrylate (including 8.00g acrylic acid, 12.00g hydroxyethyl acrylate, 10.00g hydroxypropyl acrylate and 20.00g water), a hydrogen peroxide aqueous solution (including 1.30g hydrogen peroxide and 20.00g water), a thioglycolic acid aqueous solution (including 0.90g thioglycolic acid and 20.00g water), and a bleaching solution (including 0.30 bleaching solution and 20.00g water) were added dropwise. The initial reaction temperature was 13°C, the dropping time was 0.75h, and the material temperature was controlled to be ≤25°C during the dropping process. After the dropping was completed, the mixture was kept warm for 1h to obtain a copolymer product.

[0035] (2) Add 3 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid collapse retaining agent KZJ-2. Example 3

[0036] (1) 180.00 g of ethylene glycol monovinyl polyglycol ether with a molecular weight of 2400, 1.00 g of 4-vinylphenyl diethyl phosphate, 1.50 g of 2-methyl-2-(4-vinylphenyl) propionic acid, 4.00 g of 4-(allyloxy)benzoic acid, 2.50g sodium hypophosphite, 0.005g ferrous sulfate and 145.00g water were added to the reactor, and the agitator and temperature control device were turned on. After the materials were evenly mixed, a mixed aqueous solution of acrylic acid, maleic anhydride and hydroxypropyl acrylate (including 5.00g acrylic acid, 2.00g maleic anhydride, 28.00g hydroxypropyl acrylate and 20.00g water), a hydrogen peroxide aqueous solution (including 1.50g hydrogen peroxide and 20.00g water) and an ascorbic acid aqueous solution (including 0.40 ascorbic acid and 20.00g water) were added dropwise. The initial reaction temperature was 12°C, the dropping time was 1h, and the material temperature was controlled to be ≤30°C during the dropping process. After the dropping was completed, the mixture was kept warm for 1h to obtain a copolymer product.

[0037] (2) Add 4 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid collapse retaining agent KZJ-3. Example 4

[0038] (1) 120.00 g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 60.00 g of 2-methylallyl polyethylene glycol with a molecular weight of 2400, 1.50 g of (4-vinylphenyl) methanesulfonic acid, 1.50 g of 4-vinyl-ethyl benzoate, 2.00 g of 4-vinyloxybenzenesulfonic acid, 3.00 g of 4-(allyloxy)benzoic acid, 1 g of glycidyl acrylate, 3.00 g of sodium hypophosphite, 0.004 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were mixed evenly, a mixed aqueous solution of acrylic acid and hydroxypropyl acrylate (including 5.00 g of acrylic acid, 32.00 g of hydroxypropyl acrylate and 20.00 g of water), a hydrogen peroxide solution (including 1.20 g of hydrogen peroxide and 20.00 g of water) and BRUGGOLITE were added dropwise. E51 aqueous solution (including 0.28g BRUGGOLITE E51 and 20.00g water), the initial reaction temperature is 18°C, the dropping time is 1.5h, the material temperature is controlled to be ≤30°C during the dropping process, and the temperature is kept for 0.5h after the dropping is completed to obtain the copolymer product;

[0039] (2) Add 3 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid collapse retaining agent KZJ-4. Example 5

[0040] (1) 100.00 g of ethylene glycol monovinyl polyethylene glycol ether with a molecular weight of 3000, 80.00 g of 3-methyl-3-butene-1-polyethylene glycol with a molecular weight of 2400, 2.40 g of (4-vinylphenyl)methanesulfonic acid, 2.00 g of 4-(allyloxy)benzoic acid, 2.00 g of 4-(allyloxy)benzenesulfonamide, 1.00 g of 4-Hydroxybutyl acrylate glycidyl ether, 0.004g ferrous sulfate and 145.00g water are added to the reactor, and the stirrer and temperature control device are turned on. After the materials are evenly mixed, acrylic acid aqueous solution, hydroxyethyl acrylate, hydroxypropyl methacrylate mixed aqueous solution (including 10.00g acrylic acid, 18.00g hydroxyethyl acrylate, 2.00g hydroxypropyl methacrylate, and 20.00g water), hydrogen peroxide aqueous solution (including 1.50g hydrogen peroxide and 20.00g water), mercaptopropionic acid aqueous solution (including 0.70g mercaptoethanol and 20.00g water), ascorbic acid aqueous solution (including 0.40 ascorbic acid and 20.00g water) are added dropwise. The initial reaction temperature is 15°C, the dropping time is 1.0h, the material temperature is controlled to be ≤25°C during the dropping process, and the temperature is kept for 0.5h after the dropping is completed to obtain a copolymer product;

[0041] (2) Add 4 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain the novel polycarboxylic acid collapse retaining agent, which is denoted as KZJ-5.

[0042] Comparative Example 1

[0043] (1) 180.00 g of 3000 molecular weight ethylene glycol monovinyl polyethylene glycol ether, 4.00 g of 4-vinyloxybenzenesulfonic acid, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were mixed evenly, a mixed aqueous solution of acrylic acid and hydroxyethyl acrylate (including 7.00 g of acrylic acid, 20.00 g of hydroxyethyl acrylate and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including BRUGGOLITE E51 0.25g, water 20.00g), the initial reaction temperature is 15°C, the dropping time is 1.0h, the material temperature is controlled to be ≤30°C during the dropping process, and the temperature is kept for 1h after the dropping is completed to obtain a copolymer product;

[0044] (2) Add 3 g of 32% sodium hydroxide aqueous solution to the copolymer product obtained in step (1) to obtain comparative sample PCE-1.

[0045] Comparative Example 2

[0046] (1) 180.00 g of 3000 molecular weight ethylene glycol monovinyl polyethylene glycol ether, 2.00 g of 4-vinyl-methyl benzoate, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were mixed evenly, a mixed aqueous solution of acrylic acid and hydroxyethyl acrylate (including 7.00 g of acrylic acid, 20.00 g of hydroxyethyl acrylate and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including BRUGGOLITE E51 0.25g, water 20.00g), the initial reaction temperature is 15°C, the dropping time is 1.0h, the material temperature is controlled to be ≤30°C during the dropping process, and the temperature is kept for 1h after the dropping is completed to obtain a copolymer product;

[0047] (2) Add 3 g of 32% aqueous sodium hydroxide solution to the copolymer product obtained in step (1) to obtain sample PCE-2.

[0048] Comparative Example 3

[0049] (1) 180.00 g of ethylene glycol monovinyl polyglycol ether with a molecular weight of 3000, 0.006 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were evenly mixed, a mixed aqueous solution of acrylic acid and hydroxyethyl acrylate (including 7.00 g of acrylic acid, 20.00 g of hydroxyethyl acrylate and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.50 g of hydrogen peroxide and 20.00 g of water), a mercaptopropionic acid aqueous solution (including 0.70 g of mercaptopropionic acid and 20.00 g of water), and a BRUGGOLITE E51 aqueous solution (including 0.25 g of BRUGGOLITE E51 and 20.00 g of water) were added dropwise. The initial reaction temperature was 15° C. The dropping time was 1.0 h. The material temperature was controlled to be ≤30° C. After the dropping was completed, the mixture was kept warm for 1 h to obtain a copolymer product.

[0050] (2) Add 3 g of 32% aqueous sodium hydroxide solution to the copolymer product obtained in step (1) to obtain sample PCE-3.

[0051] Comparative Example 4

[0052] (1) 180.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 3000, 2.00 g of sodium (4-vinylphenyl) methanesulfonate, 2.00 g of 4-(vinyloxy)benzenesulfonamide, 0.005 g of ferrous sulfate and 145.00 g of water were added to a reactor, and the agitator and temperature control device were turned on. After the materials were evenly mixed, an acrylic acid aqueous solution (including 8.00 g of acrylic acid and 20.00 g of water), a hydrogen peroxide aqueous solution (including 1.30 g of hydrogen peroxide and 20.00 g of water), a thioglycolic acid aqueous solution (including 0.90 g of thioglycolic acid and 20.00 g of water), and a bleaching agent aqueous solution (including 0.30 g of bleaching agent and 20.00 g of water) were added dropwise. The initial reaction temperature was 13° C., the dropping time was 0.75 h, and the material temperature was controlled to be ≤25° C. During the dropping process, the temperature was kept at 1 h after the dropping was completed to obtain a copolymer product;

[0053] (2) Add 3 g of 32% aqueous sodium hydroxide solution to the copolymer product obtained in step (1) to obtain sample PCE-4.

[0054] Concrete performance test:

[0055] Using the concrete raw materials and mix ratio shown in Table 1, and the admixture formula shown in Table 2, the performance tests were conducted on the novel polycarboxylic acid slump retaining agents prepared in Examples 1 to 5 and the comparative samples prepared in Comparative Examples 1 to 3. The test environment temperature was 30±2° C. The test results are shown in Table 3:

[0056] Table 1 Concrete mix ratio

[0057]

[0058] Table 2 Admixture formula

[0059]

[0060] Note: The concentration of the slump retaining agent is diluted to a solid content of 20%, the water reducer is the mother liquor of Point-S504 polycarboxylate water reducer of KZJ with a solid content of 50%, the air entraining agent is KZJ-AE30 air entraining agent, and the defoaming agent is KZJ-X20 defoaming agent.

[0061] Table 3 Concrete properties of different collapse-preventing agents

[0062]

[0063] Note: “×” in Table 3 indicates that the expansion is very small.

[0064] As shown in Table 1:

[0065] The results of the comparison between KZJ-1 and PCE-1 show that after removing 4-vinyl-methyl benzoate from KZJ-1, the fluidity of concrete at the initial, 1h, 2h, and 3h levels decreased slightly (Note: when there is expansion, the fluidity of concrete mainly depends on the expansion; when there is no expansion, the fluidity of concrete mainly depends on the slump);

[0066] The results of the comparison between KZJ-1 and PCE-2 showed that after removing 4-vinyloxybenzenesulfonic acid from KZJ-1, the fluidity of the concrete at initial, 1h, 2h, and 3h decreased slightly;

[0067] The results of the comparison between KZJ-1 and PCE-3 show that after removing 4-vinyl-benzoic acid methyl ester and 4-vinyloxybenzenesulfonic acid from KZJ-1, the fluidity of concrete at the initial, 1h, 2h, and 3h levels decreased significantly;

[0068] The results of the comparison between KZJ-2 and PCE-4 showed that after removing 1.00 g of ethylene glycol diacrylate, 12.00 g of hydroxyethyl acrylate, and 10.00 g of hydroxypropyl acrylate from KZJ-2, the fluidity of the concrete at the initial, 1 h, 2 h, and 3 h levels decreased significantly;

[0069] The product synthesized according to the technical solution of the present invention enables the concrete to have higher initial and 1h, 2h, and 3h fluidity, indicating that the product has better initial water-reducing and dispersing effect and 1h, 2h, and 3h collapse-preserving effect.

[0070] Using the concrete raw materials and mix ratio shown in Table 4 and the admixture formula shown in Table 2, the performance tests were conducted on the novel polycarboxylic acid slump retaining agents prepared in Examples 1 to 5 and the comparative samples prepared in Comparative Examples 1 to 3. The test environment temperature was 30±2° C. The test results are shown in Table 5:

[0071] Table 4 Concrete mix ratio

[0072]

[0073] Table 5 Concrete properties of different collapse-preventing agents

[0074]

[0075] Note: “×” in Table 5 indicates that the expansion is very small.

[0076] Comparing Table 3 and Table 5, the 50kg / m 3 After the artificial sand was replaced by the mud washed and dried from the artificial sand, the initial and 1h, 2h and 3h decrease values ​​of the fluidity of the concrete of KZJ-1 to KZJ-5 affected by the mud were significantly smaller than the initial and 1h, 2h and 3h decrease values ​​of the fluidity of the concrete of PCE-1 to PCE-4 affected by the mud, indicating that the product synthesized according to the technical solution of the present invention has better anti-mud effect.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polycarboxylic acid collapse-preventing agent, characterized in that: A polycarboxylic acid collapse-preventing agent produced by polymerization reaction of compound A, compound B, unsaturated macromonomer, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, and unsaturated carboxylic ester under the action of an initiator and a molecular weight regulator; The unsaturated carboxylic acid ester is at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-propylene glycol diacrylate, 1,5-pentanediol dimethacrylate, glycerol 1,3-dimethacrylate, glycidyl acrylate, glycidyl methacrylate, and 4-hydroxybutyl acrylate glycidyl ether; The compound A is at least one of (4-vinylphenyl)methanesulfonic acid, sodium (4-vinylphenyl)methanesulfonate, 4-vinylphenylacetic acid, 4-vinylbenzoic acid, 2-methyl-2-(4-vinylphenyl)propionic acid, 4-vinyl-benzoic acid methyl ester, 4-vinyl-benzoic acid ethyl ester, 4-vinylphenylethyl ester, and 4-vinylphenyl diethyl phosphate; The compound B is at least one of 4-vinyloxybenzenesulfonic acid, 4-vinyloxybenzoic acid, 4-vinyloxyphenylacetic acid, sodium 4-vinyloxybenzenesulfonate, potassium 4-vinyloxybenzenesulfonate, methyl 4-vinyloxybenzoate, ethyl 4-vinyloxybenzoate, methyl 4-vinyloxyphenylacetate, ethyl 4-vinyloxyphenylacetate, 4-(allyloxy)benzenesulfonamide, 4-(vinyloxy)benzenesulfonamide, 2-(vinyloxy)benzenesulfonamide, and 4-(allyloxy)benzoic acid; and the mass ratio of the unsaturated macromonomer, compound A, compound B, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, and unsaturated carboxylic ester is 180:(1-5):(1-10):(5-30):(10-40).

2. A polycarboxylic acid collapse-preventing agent according to claim 1, characterized in that: The molecular weight of the unsaturated macromonomer is 600-6000, and the unsaturated macromonomer is at least one of 3-methyl-3-butene-1-polyethylene glycol, 2-methylallyl polyethylene glycol, ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutyl vinyl polyoxyethylene ether, methoxy polyethylene glycol methacrylate, and methoxy polyethylene glycol acrylate.

3. A polycarboxylic acid collapse-preventing agent according to claim 1, characterized in that: The unsaturated carboxylic acid and / or unsaturated carboxylic anhydride is at least one of acrylic acid, methacrylic acid and maleic anhydride.

4. A polycarboxylic acid collapse-preventing agent according to claim 1, characterized in that: The amount of the initiator used is 0.5-3.0% of the total mass of the reactants; the amount of the molecular weight regulator used is 0.2-3.0% of the total mass of the reactants.

5. A polycarboxylic acid collapse-preventing agent according to claim 1, characterized in that: The initiator is a water-soluble redox initiator system or a water-soluble peroxide initiator system reagent.

6. A polycarboxylic acid collapse-preventing agent according to claim 1, characterized in that: The molecular weight regulator is at least one of thioglycolic acid, mercaptoethanol, mercaptopropionic acid, sulfonated mercaptopropionic acid, and sodium hypophosphite.

7. A method for preparing a polycarboxylic acid collapse-preventing agent according to any one of claims 1 to 6, characterized in that: At least the following steps are included: The unsaturated macromonomer, compound A, compound B and water are added to the reactor and stirred. After the materials are evenly mixed, unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, unsaturated carboxylic ester, initiator and molecular weight regulator are added dropwise. The dropping time is 0.5-2h, the initial reaction temperature is 10-25°C, and the material temperature is controlled at 10-30°C during the dropping process; after the dropping is completed, the temperature is kept for 0.5-1h to obtain a copolymer product; in the copolymer product, a base is added to adjust the pH value of the product to 5-7 or no base is added to adjust the pH value, so as to obtain the polycarboxylic acid collapse retaining agent.

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