A hydrophobic modified emulsion thickener for waterproof coating and preparation method thereof

Abstract

The present invention belongs to the technical field of thickeners, and specifically relates to a hydrophobic modified emulsion thickener for waterproof coatings and a preparation method thereof. It is prepared from effective raw material components and water in a mass ratio of 1: (2-5); by weight, the effective raw material components include: 100 parts of hydrophilic vinyl monomers, 15-40 parts of vinyl imidazole ionic liquid monomers, 40-100 parts of vinyl hydrophobic monomers, 2-8 parts of polyolefin acrylic acid monomers, 3-10 parts of emulsifiers, and 0.1-1.5 parts of initiators. The thickener in the present invention has excellent hydrophobicity. When used in waterproof coatings, it can significantly improve the performance of waterproof coatings, and at the same time has excellent salt resistance and high temperature resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of thickeners, and in particular relates to a hydrophobic modified emulsion thickener for waterproof coatings and a preparation method thereof. Background Art

[0002] A coating thickener is an additive used to increase the viscosity of the coating. It can improve the rheological properties of the coating and enhance the coating's coating and stability. In the coating formulation, the use of thickeners can prevent pigment sedimentation and improve the uniformity and hiding power of the coating. Common coating thickeners include cellulose, polyacrylate, bentonite, etc. Choosing the right thickener is crucial to the final performance of the coating.

[0003] There are mainly the following types of thickeners for coatings: 1. Cellulose thickeners: such as hydroxypropyl methylcellulose (HPMC) and carboxymethyl cellulose (CMC). Their advantages are good thickening effect, high stability and environmental friendliness. However, water-soluble or water-swelling polymers, although they can effectively adjust the viscosity, may not be satisfactory in improving the waterproof performance, especially in a continuously humid environment, which will affect the waterproofness of the coating; 2. Polymer thickeners: including polyacrylates and polyurethanes. The advantages of this type of thickener are good weather resistance and a wide range of applications, but they may not be satisfactory in improving the waterproof performance; 3. Inorganic thickeners: such as bentonite and magnesium silicate. Their advantages are low cost and good stability, but the thickening effect may not be as good as that of organic thickeners, and may affect the gloss and leveling of the coating; 4. Natural gum thickeners: such as xanthan gum and guar gum. The advantages of this type of thickener are good biodegradability and environmental friendliness, but they may be affected by microbial degradation and have poor stability; 5. Silicone thickeners: Their advantages are good high and low temperature resistance and good shear stability. The disadvantages are high cost and may affect the thixotropy of the coating. Currently, the most commonly used are polymer thickeners. For example, the patent with authorization announcement number CN112898530B provides a weakly ionic polyurethane thickener with a side long-chain alkyl group and a preparation method thereof, which includes the steps of raw material preparation, prepolymerization, chain extension and end-capping, wherein the polymerized monomers include components such as diisocyanate, polyethylene glycol, chain extender and end-capping agent. The weakly ionic polyurethane thickener with long-chain side alkyl groups prepared by the method has high thickening ability and salt resistance, and has longer side chain alkyl groups, which improves its emulsification and dispersion properties. Although the longer side chain alkyl groups can increase the thickening hydrophobicity to a certain extent, the single long-chain side alkyl groups have limited effect on enhancing the salt resistance. The monomers containing longer side chain alkyl groups have poor polymerization activity in the polymerization system, resulting in poor stability of the thickener.

[0004] Therefore, there is an urgent need for a hydrophobic modified emulsion thickener for waterproof coatings with excellent hydrophobicity and salt resistance. Summary of the invention

[0005] The object of the present invention is to provide a hydrophobic modified emulsion thickener for waterproof coatings, which has excellent salt resistance and hydrophobicity.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a hydrophobic modified emulsion thickener for waterproof coatings, which is prepared from effective raw material components and water in a mass ratio of 1: (2-5); in parts by weight, the effective raw material components include: 100 parts of hydrophilic vinyl monomers, 15-40 parts of vinyl imidazole ionic liquid monomers, 40-100 parts of vinyl hydrophobic monomers, 2-8 parts of polyolefin acrylic acid monomers, 3-10 parts of emulsifiers, and 0.1-1.5 parts of initiators.

[0008] Furthermore, the mass ratio of the effective raw material component to water is 1:(2.8-3.2).

[0009] Furthermore, the effective raw material components include, by weight: 100 parts of hydrophilic vinyl monomer, 18-23 parts of vinyl imidazole ionic liquid monomer, 65-70 parts of vinyl hydrophobic monomer, 4.2-5 parts of polyolefin acrylic monomer, 6-8 parts of emulsifier, and 0.6-1 part of initiator.

[0010] The hydrophilic vinyl monomer is a type of vinyl compound containing a hydrophilic group, which can introduce a hydrophilic group in the polymerization reaction, thereby giving the polymer good water solubility or water dispersibility. Further, the hydrophilic vinyl monomer is selected from at least one of acrylic acid, methacrylic acid, hydroxyethyl methacrylate, methacrylamide, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, vinyl pyrrolidone, crotonic acid and aconitic acid.

[0011] Furthermore, the hydrophilic vinyl monomer is a composition of acrylic acid and 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate.

[0012] In the prior art, the thickener prepared by adding vinyl hydrophobic monomers has a certain salt resistance, but the anti-ion effect of the hydrophobic segments in the vinyl hydrophobic monomers is limited. In the present invention, it is found through research that the addition of 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate can not only increase the dispersibility of the thickener in water, but also further increase the salt resistance of the thickener. This may be because the phosphate group reacts with ions (such as Ca 2+) has a certain complexing ability, thereby increasing the salt resistance of the thickener. And after research, it was found that when 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate was used alone as a hydrophilic vinyl monomer, the overall performance of the thickener was reduced. This may be because the single 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate cannot form the main chain of the thickener well and cannot be well copolymerized with other monomers.

[0013] Furthermore, in order to enable 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate to better increase the salt resistance of the thickener in the polymerization system, the weight ratio of acrylic acid to 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate is 1:(0.2-0.8), for example, 1:0.2, 1:0.3, 1:0.35, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, preferably 1:(0.35-0.4).

[0014] Vinyl hydrophobic monomers are compounds containing vinyl groups (-CH=CH2), which are hydrophobic in chemical properties, i.e., repellent to water. Such monomers can be copolymerized with other monomers in the polymerization reaction to form polymers with hydrophobic properties. In order to better increase the hydrophobicity of the thickener, the vinyl hydrophobic monomer is further selected from a combination of a long-chain alkyl acrylate and a phenyl-containing vinyl hydrophobic monomer, and the weight ratio of the long-chain alkyl acrylate to the phenyl-containing vinyl hydrophobic monomer is 1: (0.1-0.5), for example, 1: 0.1, 1: 0.15, 1: 0.2, 1: 0.25, 1: 0.3, 1: 0.35, 1: 0.4, 1: 0.45, 1: 0.5, preferably 1: (0.35-0.4).

[0015] Furthermore, the long-chain alkyl acrylate is selected from C8-C20 alkyl (meth)acrylate, preferably selected from C12-C18 alkyl (meth)acrylate.

[0016] Examples of the C12-C18 alkyl (meth)acrylates that can be used in the present invention include dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, and the like.

[0017] Furthermore, the phenyl-containing vinyl hydrophobic monomer is selected from styrene and / or α-methylstyrene, preferably styrene.

[0018] In the present invention, the combination of a long-chain alkyl acrylate and a phenyl-containing vinyl hydrophobic monomer is used as the introduction of a benzene ring into the vinyl hydrophobic monomer, which can increase the temperature resistance of the thickener to a certain extent.

[0019] The alkenyl imidazolium ionic liquid monomer is an ionic liquid containing an alkenyl group and an imidazole ring structure. Such compounds are generally composed of an imidazolium cation and a corresponding anion, and the structure of the imidazolium cation contains one or more alkenyl substituents. Further, the alkenyl imidazolium ionic liquid monomer is selected from at least one of 1-allyl-3-methylimidazolium tetrafluoroborate, 1-propenyl-2,3-dimethylimidazolium p-toluenesulfonate and 1-vinyl-3-butylimidazolium hexafluorophosphate, preferably 1-vinyl-3-butylimidazolium hexafluorophosphate.

[0020] The present invention introduces the structural unit provided by the vinyl imidazole ionic liquid monomer into the molecular chain of the polymer, which can not only increase the salt resistance of the thickener, but also increase the high-temperature stability of the thickener. On the one hand, it can better undergo polymerization reaction, and on the other hand, its special imidazole structure can hinder the curling of molecules under high salt conditions, thereby improving the salt resistance of the thickener. At the same time, imidazole has a certain steric hindrance effect, which can hinder the thermal motion of the molecular chain at high temperature, thereby improving the stability of the thickener.

[0021] Polyolefin acrylic monomers are a class of acrylic compounds containing multiple double bonds, which contain two or more acrylic groups in the chemical structure. Such compounds can make the thickener have a network structure or a multi-scale dendritic structure because of their multiple reactive double bonds. Further, the polyolefin acrylic monomer is selected from at least one of tetraallyl pentaerythritol ether, diallyl phthalate, N,N-methylenebisacrylamide, trimethylolpropane diallyl ether and polyethylene glycol dimethacrylate.

[0022] Furthermore, the polyalkenyl acrylic acid monomer is a combination of tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether.

[0023] Furthermore, the weight ratio of tetraallyl pentaerythritol ether to trimethylolpropane diallyl ether is 1:(0.6-2), for example, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, preferably 1:(0.8-1.2).

[0024] In the present invention, it is found through experiments that the use of tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether as polyolefin acrylic monomers makes the thickener have better hydrophobicity. When used in waterproof coatings, the waterproof coatings can have better waterproof properties. This may be because the polymerization reaction has different reactivity at the polymerization site during the polymerization process. Tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether contain four alkenyl groups and two double bond alkenyl groups, respectively, and have different reactivity. The synergistic effect of the two can promote polymerization between polymer molecules, especially promote the hydrophobic association of long-chain alkyl acrylates in vinyl hydrophobic monomers in the polymerization system, and enhance the tendency of the thickener to form a hydrophobic three-dimensional network structure.

[0025] Furthermore, the emulsifier is selected from at least one of Span-80, Tween, mono- and di-glycerides, sodium pentadecylbenzene sulfonate, sodium diisobutylnaphthalene sulfonate and sodium dodecylbenzene sulfonate, preferably a combination of mono- and di-glycerides and sodium pentadecylbenzene sulfonate.

[0026] Furthermore, the weight ratio of the mono- and di-glycerides to sodium pentadecylbenzene sulfonate is 1:(0.5-1), for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, preferably 1:(0.6-0.7).

[0027] After research, it was found that the use of mono- and di-glycerides and sodium pentadecylbenzene sulfonate as emulsifiers can further ensure the overall performance of the thickener. This may be because the emulsion system formed by mono- and di-glycerides and sodium pentadecylbenzene sulfonate helps the specific monomers in the present invention to undergo polymerization reactions smoothly, thereby avoiding the instability of the emulsion during the reaction, which leads to a low reaction conversion rate and affects the overall performance of the thickener.

[0028] Initiators are compounds used to start or accelerate the polymerization process. In the polymerization reaction, monomer molecules form polymer chains through the action of the initiator. Further, the initiator is a persulfate initiator, preferably ammonium persulfate or potassium persulfate.

[0029] In a second aspect, the present invention provides a method for preparing the hydrophobic modified emulsion thickener for waterproof coatings according to the first aspect of the present invention, the preparation method comprising the following steps:

[0030] (1) first mixing the emulsifier with water accounting for 65-70% of the total amount of water to obtain an emulsifier solution;

[0031] (2) mixing the initiator with water accounting for 5-10% of the total amount of water for a second time to obtain an initiator solution;

[0032] (3) a hydrophilic vinyl monomer, an vinyl imidazole ionic liquid monomer, a vinyl hydrophobic monomer and a polyolefin acrylic acid monomer are mixed for a third time to obtain a mixed monomer;

[0033] (4) Weighing 5-8% of the total weight of the mixed monomer and the emulsifier solution for a fourth mixing to obtain a seed emulsion;

[0034] (5) Add the initiator solution to the seed emulsion at 82-95°C. When 1 / 4-2 / 5 of the weight of the initiator solution remains, start adding the remaining mixed monomers. After the addition of the remaining mixed monomers and the initiator solution is complete, keep the mixture warm for 2-3 hours. Then, cool the reaction product to 50-65°C and add the remaining water for the fifth mixing. Filter to obtain a hydrophobic modified emulsion thickener for waterproof coatings.

[0035] Furthermore, in step (1), the first mixing condition is stirring at a speed of 300-500 r / min for 30-60 min.

[0036] Furthermore, in step (2), the second mixing condition is stirring at a speed of 300-500 r / min for 5-20 min.

[0037] Furthermore, in step (3), the third mixing condition is stirring at a speed of 300-500 r / min for 30-60 min.

[0038] Furthermore, in step (4), the fourth mixing condition is stirring at a speed of 300-500 r / min for 30-60 min.

[0039] Furthermore, in step (5), the initiator solution is added at a rate of 30-35 drops / minute, and the remaining mixed monomers are added at a rate of 50-60 drops / minute.

[0040] The filtering method in step (5) of the present invention can be a conventional method in the art, for example, using a 340-600 mesh filter cloth to filter the material.

[0041] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0042] 1. Although the thickeners in the prior art can effectively adjust the viscosity when used in coatings, they may not be satisfactory in improving the waterproof performance, especially in a continuous humid environment. In addition, these thickeners may reduce the overall hydrophobicity of the coating. The hydrophobic modified emulsion thickener prepared by the present invention, which contains a specific effective raw material component of a vinyl hydrophobic monomer, makes the thickener have better hydrophobicity. Using it in waterproof coatings can significantly improve the performance of waterproof coatings.

[0043] 2. The present invention introduces structural units brought by vinyl imidazolium ionic liquid monomers into the modified emulsion thickener, so that the hydrophobic modified emulsion thickener has excellent high-temperature stability.

[0044] 3. The reaction system of the present invention uses water as a medium, which has significant advantages in processes and products with high requirements for environmental performance. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0046] Example 1

[0047] This embodiment provides a hydrophobic modified emulsion thickener for waterproof coatings, which is prepared from effective raw material components and water in a mass ratio of 1:3; in parts by weight, the effective raw material components include: 100 parts of hydrophilic vinyl monomer, 20 parts of vinyl imidazole ionic liquid monomer, 68 parts of vinyl hydrophobic monomer, 4.5 parts of polyolefin acrylic acid monomer, 7.2 parts of emulsifier, and 0.7 parts of initiator;

[0048] The hydrophilic vinyl monomer is a composition of acrylic acid and 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate; the weight ratio of acrylic acid to 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate is 1:0.38;

[0049] The vinyl hydrophobic monomer is a combination of a long-chain alkyl acrylate and a phenyl-containing vinyl hydrophobic monomer; the weight ratio of the long-chain alkyl acrylate to the phenyl-containing vinyl hydrophobic monomer is 1:0.4; the long-chain alkyl acrylate is octadecyl (meth)acrylate; the phenyl-containing vinyl hydrophobic monomer is styrene;

[0050] The vinyl imidazolium ionic liquid monomer is 1-vinyl-3-butyl imidazolium hexafluorophosphate;

[0051] The polyalkenyl acrylic monomer is a combination of tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether; the weight ratio of tetraallyl pentaerythritol ether to trimethylolpropane diallyl ether is 1:1;

[0052] The emulsifier is a combination of mono- and di-glycerides and sodium pentadecylbenzene sulfonate; the weight ratio of mono- and di-glycerides to sodium pentadecylbenzene sulfonate is 1:0.65;

[0053] The initiator is ammonium persulfate.

[0054] The preparation method of the hydrophobic modified emulsion thickener for waterproof coating is as follows:

[0055] (1) first mixing the emulsifier with water accounting for 70% of the total amount of water to obtain an emulsifier solution;

[0056] (2) mixing the initiator with water accounting for 8% of the total amount of water for a second time to obtain an initiator solution;

[0057] (3) a hydrophilic vinyl monomer, an vinyl imidazole ionic liquid monomer, a vinyl hydrophobic monomer and a polyolefin acrylic acid monomer are mixed for a third time to obtain a mixed monomer;

[0058] (4) Weighing 6% of the mixed monomers and the emulsifier solution to perform a fourth mixing to obtain a seed emulsion;

[0059] (5) At 88° C., the initiator solution is added dropwise to the seed emulsion. When 1 / 4 of the weight of the initiator solution remains, the remaining mixed monomer is added dropwise. After the remaining mixed monomer and the initiator solution are added dropwise, the mixture is kept warm for 2.5 hours. After that, the reaction product is cooled to 55° C. and the remaining water is added for the fifth mixing. The mixture is filtered to obtain a hydrophobic modified emulsion thickener for waterproof coatings.

[0060] In step (1), the first mixing condition is stirring at a speed of 400 r / min for 40 minutes; in step (2), the second mixing condition is stirring at a speed of 400 r / min for 10 minutes; in step (3), the third mixing condition is stirring at a speed of 400 r / min for 30 minutes; in step (4), the fourth mixing condition is stirring at a speed of 400 r / min for 50 minutes; in step (5), the initiator solution is added at a dripping speed of 30 drops / minute, and the remaining mixed monomers are added at a dripping speed of 55 drops / minute; in step (5), the filtering method is to filter the material using a 400-mesh filter cloth.

[0061] Example 2

[0062] This embodiment provides a hydrophobic modified emulsion thickener for waterproof coatings, which is prepared from effective raw material components and water in a mass ratio of 1:4; in parts by weight, the effective raw material components include: 100 parts of hydrophilic vinyl monomer, 23 parts of vinyl imidazole ionic liquid monomer, 70 parts of vinyl hydrophobic monomer, 5 parts of polyolefin acrylic acid monomer, 8 parts of emulsifier, and 0.8 parts of initiator;

[0063] The hydrophilic vinyl monomer is a composition of acrylic acid and 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate; the weight ratio of acrylic acid to 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate is 1:0.4;

[0064] The vinyl hydrophobic monomer is a combination of a long-chain alkyl acrylate and a phenyl-containing vinyl hydrophobic monomer; the weight ratio of the long-chain alkyl acrylate to the phenyl-containing vinyl hydrophobic monomer is 1:0.4; the long-chain alkyl acrylate is octadecyl (meth)acrylate; the phenyl-containing vinyl hydrophobic monomer is styrene;

[0065] The vinyl imidazolium ionic liquid monomer is 1-vinyl-3-butyl imidazolium hexafluorophosphate;

[0066] The polyolefin acrylic monomer is a combination of tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether; the weight ratio of tetraallyl pentaerythritol ether to trimethylolpropane diallyl ether is 1:1.2;

[0067] The emulsifier is a combination of mono- and di-glycerides and sodium pentadecylbenzene sulfonate; the weight ratio of mono- and di-glycerides to sodium pentadecylbenzene sulfonate is 1:0.7;

[0068] The initiator is ammonium persulfate.

[0069] The preparation method of the hydrophobic modified emulsion thickener for waterproof coating is as follows:

[0070] (1) first mixing the emulsifier with water accounting for 70% of the total amount of water to obtain an emulsifier solution;

[0071] (2) mixing the initiator with water accounting for 10% of the total amount of water for a second time to obtain an initiator solution;

[0072] (3) a hydrophilic vinyl monomer, an vinyl imidazole ionic liquid monomer, a vinyl hydrophobic monomer and a polyolefin acrylic acid monomer are mixed for a third time to obtain a mixed monomer;

[0073] (4) Weighing 8% of the total weight of the mixed monomers and the emulsifier solution for a fourth mixing to obtain a seed emulsion;

[0074] (5) At 90° C., the initiator solution is added dropwise to the seed emulsion. When 2 / 5 of the weight of the initiator solution remains, the remaining mixed monomer is added dropwise. After the remaining mixed monomer and the initiator solution are added dropwise, the mixture is kept warm for 3 hours. After that, the reaction product is cooled to 65° C. and the remaining water is added to perform the fifth mixing. The mixture is filtered to obtain a hydrophobic modified emulsion thickener for waterproof coatings.

[0075] In step (1), the first mixing condition is stirring at a speed of 400 r / min for 40 minutes; in step (2), the second mixing condition is stirring at a speed of 400 r / min for 10 minutes; in step (3), the third mixing condition is stirring at a speed of 400 r / min for 30 minutes; in step (4), the fourth mixing condition is stirring at a speed of 400 r / min for 50 minutes; in step (5), the initiator solution is added at a dripping speed of 30 drops / minute, and the remaining mixed monomers are added at a dripping speed of 55 drops / minute; in step (5), the filtering method is to filter the material using a 400-mesh filter cloth.

[0076] Comparative Example 1

[0077] The difference between this comparative example and Example 1 is:

[0078] The hydrophilic vinyl monomer is a composition of acrylic acid and methacrylic acid; the weight ratio of acrylic acid to methacrylic acid is 1:0.38.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 1 is:

[0081] The hydrophilic vinyl monomer is acrylic acid.

[0082] Comparative Example 3

[0083] The difference between this comparative example and Example 1 is:

[0084] The hydrophilic vinyl monomer is 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate.

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 1 is:

[0087] The amount of vinyl imidazolium ionic liquid monomer is 0 parts.

[0088] Comparative Example 5

[0089] The difference between this comparative example and Example 1 is:

[0090] The polyalkenyl acrylic monomer is tetraallyl pentaerythritol ether.

[0091] Comparative Example 6

[0092] The difference between this comparative example and Example 1 is:

[0093] The polyalkenyl acrylic monomer is trimethylolpropane diallyl ether.

[0094] Comparative Example 7

[0095] The difference between this comparative example and Example 1 is:

[0096] The emulsifiers are mono- and di-glycerides.

[0097] Comparative Example 8

[0098] The difference between this comparative example and Example 1 is:

[0099] The emulsifier is sodium pentadecylbenzene sulfonate.

[0100] Performance Testing

[0101] 1. Stability test: The thickeners in the examples and comparative examples were placed at 55°C for 24 hours. If there was no stratification, it was qualified; otherwise, it was unqualified.

[0102] 2. Salt resistance test: First, use rotor No. 6, use NB-3 digital viscometer at 5 rpm and room temperature to test the viscosity of the thickener, recorded as ηbefore, then add 0.05wt% calcium chloride to the thickener and stir evenly, then use the same method to test the viscosity, recorded as ηafter, and calculate the viscosity reduction rate; viscosity reduction rate = (ηbefore - ηafter) / ηbefore × 100%.

[0103] 3. Use the thickeners in the examples and comparative examples to prepare polymer cement waterproof coatings according to the following method:

[0104] (1) Prepare the liquid material by weight: 65 parts of Yoshida water-based fluorocarbon resin emulsion model F13-0801, 0.3 parts of defoamer, 6 parts of water, 0.1 parts of thickener, and 3 parts of alcohol ester twelve;

[0105] (2) Preparation of liquid material: Add Yoshida water-based fluorocarbon resin emulsion, defoamer, water, thickener and alcohol ester twelve into a stirring kettle, start the stirring kettle, stir for 15 minutes, and obtain a liquid material after being evenly dispersed;

[0106] (3) Prepare the powder materials by weight: 66 parts of 32.5 white cement, 36 parts of quartz sand, 48 parts of heavy calcium carbonate and 1 part of melamine high-efficiency water reducer;

[0107] (4) Preparation of powder: 32.5 white cement, quartz sand, heavy calcium carbonate and melamine high-efficiency water reducing agent are placed in a mortar mixer to fully disperse the powder and stir for 15 minutes to obtain powder;

[0108] (5) Preparation of polymer cement waterproof coating: Liquid and powder were stirred in a container at a mass ratio of 1:1.2 at 600 rpm for 10 minutes to obtain a polymer cement waterproof coating.

[0109] Then, the impermeability of polymer cement waterproof coating was tested according to GB / T23445-2009.

[0110] The test results are shown in Table 1:

[0111] Table 1 Performance test results

[0112]

[0113] It can be seen from the above performance test results that Examples 1-2 have excellent water resistance, salt resistance and high temperature stability, especially the comprehensive performance of Example 1 is the most outstanding. It is speculated that the structural unit brought by the introduction of vinyl imidazolium ionic liquid monomers into the modified emulsion thickener makes the hydrophobic modified emulsion thickener have excellent high temperature stability. At the same time, the hydrophobic modified emulsion thickener prepared from the specific effective raw material components of the vinyl hydrophobic monomer makes the thickener have better hydrophobicity. Using it in waterproof coatings can significantly improve the performance of waterproof coatings. However, the comparative examples are obviously inferior to the examples in the corresponding performance tests because they do not adopt the necessary technical solutions. In comparative example 1, 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate is replaced with methacrylic acid, and it can be seen that the salt resistance decreases. In comparative example 2, the hydrophilic vinyl monomer is only acrylic acid, and it can be seen that the salt resistance decreases. In comparative example 3, the hydrophilic vinyl monomer is only 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate, and it can be seen that the salt resistance and high temperature stability are both reduced, that is, the specific hydrophilic vinyl monomers acrylic acid and 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate from comparative examples 1-3 can synergistically increase the salt resistance of the thickener. In comparative example 4, no alkenyl imidazolium ionic liquid monomer is added, and the salt resistance and high temperature stability of the thickener are both reduced, proving that the addition of alkenyl imidazolium ionic liquid monomers has an effect on the high temperature stability and salt resistance of the thickener. In Comparative Example 5, the polyolefinic acrylic acid monomer only has tetraallyl pentaerythritol ether. When the thickener is used in the coating, the water resistance of the coating is reduced. In Comparative Example 6, the polyolefinic acrylic acid monomer only has trimethylolpropane diallyl ether. When the thickener is used in the coating, the water resistance of the coating is reduced. Comparative Examples 5-6 illustrate that the use of tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether as polyolefinic acrylic acid monomers makes the thickener have better hydrophobicity. When used for waterproof coatings, the waterproof coating can have better water resistance. The emulsifier in Comparative Example 7 only has mono- and di-glycerides, and the overall effect is reduced. The emulsifier in Comparative Example 8 only has pentadecylbenzene sulfonic acid, and the overall effect is reduced. Comparative Examples 7-8 illustrate that the use of mono- and di-glycerides and sodium pentadecylbenzene sulfonate as emulsifiers can further ensure the overall performance of the thickener. The above experimental results further prove the importance of the technical scheme defined in the present invention for its technical effect.

[0114] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A hydrophobic modified emulsion thickener for waterproof coating, characterized in that: The invention is prepared from effective raw material components and water in a mass ratio of 1:(2-5); the effective raw material components include, by weight: 100 parts of hydrophilic vinyl monomer, 15-40 parts of vinyl imidazole ionic liquid monomer, 40-100 parts of vinyl hydrophobic monomer, 2-8 parts of polyolefin acrylic acid monomer, 3-10 parts of emulsifier, and 0.1-1.5 parts of initiator; The hydrophilic vinyl monomer is a composition of acrylic acid and 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate, and the weight ratio of the two is 1: (0.2-0.8); The vinyl hydrophobic monomer is a combination of a long-chain alkyl acrylate and a phenyl-containing vinyl hydrophobic monomer, the weight ratio of the two being 1:(0.1-0.5); the long-chain alkyl acrylate is selected from C8-C20 alkyl (meth)acrylate; the phenyl-containing vinyl hydrophobic monomer is selected from styrene and / or α-methylstyrene; The polyalkenyl acrylic acid monomer is a combination of tetraallyl pentaerythritol ether and trimethylolpropane diallyl ether, and the weight ratio of the two is 1: (0.6-2); The emulsifier is a combination of mono- and di-glycerides and sodium pentadecylbenzene sulfonate, and the weight ratio of the two is 1: (0.5-1).

2. A hydrophobic modified emulsion thickener for waterproof coating according to claim 1, characterized in that: The effective raw material components include, by weight: 100 parts of hydrophilic vinyl monomer, 18-23 parts of vinyl imidazole ionic liquid monomer, 65-70 parts of vinyl hydrophobic monomer, 4.2-5 parts of polyolefin acrylic monomer, 6-8 parts of emulsifier, and 0.6-1 part of initiator.

3. A hydrophobic modified emulsion thickener for waterproof coating according to claim 1 or 2, characterized in that: The vinyl imidazolium ionic liquid monomer is selected from at least one of 1-allyl-3-methylimidazolium tetrafluoroborate, 1-propenyl-2,3-dimethylimidazolium p-toluenesulfonate and 1-vinyl-3-butylimidazolium hexafluorophosphate.

4. A method for preparing a hydrophobic modified emulsion thickener for waterproof coatings according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: (1) first mixing the emulsifier with water accounting for 65-70% of the total amount of water to obtain an emulsifier solution; (2) mixing the initiator with water accounting for 5-10% of the total amount of water for a second time to obtain an initiator solution; (3) a hydrophilic vinyl monomer, an vinyl imidazole ionic liquid monomer, a vinyl hydrophobic monomer and a polyolefin acrylic acid monomer are mixed for a third time to obtain a mixed monomer; (4) Weighing 5-8% of the total weight of the mixed monomer and the emulsifier solution for a fourth mixing to obtain a seed emulsion; (5) Add the initiator solution to the seed emulsion at 82-95°C. When 1 / 4-2 / 5 of the weight of the initiator solution remains, start adding the remaining mixed monomers. After the addition of the remaining mixed monomers and the initiator solution is complete, keep the mixture warm for 2-3 hours. Then, cool the reaction product to 50-65°C and add the remaining water for the fifth mixing. Filter to obtain a hydrophobic modified emulsion thickener for waterproof coatings.

5. The method for preparing a hydrophobic modified emulsion thickener for waterproof coating according to claim 4, characterized in that: In step (1), the first mixing condition is stirring at a speed of 300-500 r / min for 30-60 min; in step (2), the second mixing condition is stirring at a speed of 300-500 r / min for 5-20 min; in step (3), the third mixing condition is stirring at a speed of 300-500 r / min for 30-60 min; in step (4), the fourth mixing condition is stirring at a speed of 300-500 r / min for 30-60 min; in step (5), the initiator solution is added at a dripping speed of 30-35 drops / min, and the remaining mixed monomers are added at a dripping speed of 50-60 drops / min.

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