An additive for improving the drying speed of polymer cement-based waterproof coating, its preparation method and application, and waterproof coating

Abstract

The application discloses an additive for improving the drying speed of a polymer cement-based waterproof coating, a preparation method and application of the additive, and the waterproof coating, and the additive is shown as formula I; wherein m is an integer of 155-159, and n is an integer of 155-159; the additive is added into the polymer cement-based waterproof coating, and the drying speed of the polymer cement-based waterproof coating can be improved. In the formula I, R is

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of additives, more particularly, relates to an additive for improving the drying speed of polymer cement-based waterproof coating, a preparation method and application thereof, and a waterproof coating. BACKGROUND

[0002] Polymer cement-based waterproof coating (JS waterproof coating for short) is a two-component water-based waterproof coating composed of liquid material (synthetic high molecular polymer emulsion such as polyacrylate emulsion and various additives) and matching powder material (composed of special cement and graded sand) through compounding. This kind of coating has the advantages of high molecular polymer material such as extensibility, waterproofness, and water-hardening material such as high strength and easy bonding with a humid base, and can adjust the flexibility and strength according to the requirements of different engineering parts, and the construction method is flexible and convenient. On the other hand, with the development of society, people's requirements for environmental protection are getting higher and higher. The VOC emission in the Beijing-Tianjin-Hebei region is strictly required (DB113005-2017 Standard for Limiting Value of Volatile Organic Compounds in Building Coatings and Adhesives). JS waterproof coating uses water as a dispersant, has excellent environmental performance, and releases very low VOC, overcomes the toxicity and environmental pollution of tar, asphalt and other solvent waterproof coatings, and is widely used and has a very fast growth rate (annual demand is more than 1 million tons).

[0003] However, due to the large latent heat of water evaporation, and the influence of objective factors such as environmental temperature and humidity, ventilation conditions, etc., the drying speed of JS coating is slow in the actual application environment, which seriously affects the construction period of the project and is not conducive to the promotion and application of the product. Therefore, the improvement of the drying speed of JS waterproof coating has great significance in the field of JS waterproof coating. SUMMARY

[0004] The purpose of the present application is to provide an additive for improving the drying speed of polymer cement-based waterproof coating, a preparation method and application thereof, and a waterproof coating. The addition of the additive of the present application in the polymer cement-based waterproof coating can improve the drying speed of the polymer cement-based waterproof coating.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application provides an additive for improving the drying speed of polymer cement-based waterproof coating, which is shown as formula I; wherein m is an integer of 155-159, n is an integer of 155-159;

[0006]

[0007] In formula I, R is

[0008] In the present application, the additive for improving the drying speed of polymer cement-based waterproof coating is shown as formula I, which is a star structure, one molecule arm is connected to each silicon atom, and the molecule arms connected to four silicon atoms are all the same, that is, the value of m in each R is the same, and the value of n is the same.

[0009] The second aspect of the present application provides a preparation method of the above-mentioned additive, which comprises:

[0010] (1) performing a photo-initiated reaction on tetramethyltetra-vinylcyclotetrasiloxane and 3-mercapto-1-propanol in the presence of a first solvent and a photo-initiator to obtain a compound shown as formula II;

[0011] (2) performing a reaction on 3-benzylmercaptothiocarbonyl propionic acid and oxalyl chloride in the presence of a protective gas and a second solvent, removing the second solvent and residual oxalyl chloride, then adding a solution of the compound shown as formula II, and performing a stirring reaction in the presence of the protective gas to obtain a compound shown as formula III;

[0012] (3) adding the compound shown as formula III, 2-methyl-2-propenoic acid-2,3-dihydroxypropyl ester, a first initiator and a third solvent into a reactor to form a protective gas environment in the reactor, and then performing a reaction on the materials in the reactor under heating and stirring to obtain a polymer shown as formula IV;

[0013] (4) adding the polymer shown as formula IV, glycidyl methacrylate, a second initiator and a fourth solvent into a reactor to form a protective gas environment in the reactor, and then performing a reaction on the materials in the reactor under heating and stirring to obtain the additive (shown as formula I);

[0014] In formula II, R1 is

[0015] In formula III, R2 is

[0016]

[0017] In formula IV, R3 is n is an integer of 155-159.

[0018] In the present application, the value of n in each R3 is the same.

[0019] According to the present application, preferably, in step (1), the first solvent is tetrahydrofuran; the photo-initiator is 2,2-dimethoxy-2-phenylpropanone; and the photo-initiated reaction is performed under ultraviolet light irradiation.

[0020] The molar ratio of the tetramethyltetravinylcyclotetrasiloxane, 3-mercapto-1-propanol and photoinitiator is 1:(4-5):2.

[0021] In the present application, preferably, step (1) is to degas the material in the reactor containing tetramethyltetravinylcyclotetrasiloxane, 3-mercapto-1-propanol, photoinitiator and first solvent to remove oxygen, then irradiate with ultraviolet light to carry out photoinitiation reaction to obtain the compound shown in formula II.

[0022] According to the present application, preferably, in step (2), the protective gas is argon; the second solvent is dichloromethane; the solution of the compound shown in formula II is tetrahydrofuran solution of the compound shown in formula II.

[0023] The reaction of the 3-benzylmercaptothiocarbonyl propionic acid and oxalyl chloride is carried out at 20-30℃; the stirring reaction is carried out at 20-30℃.

[0024] The molar ratio of the 3-benzylmercaptothiocarbonyl propionic acid and oxalyl chloride is 1:(4-4.2).

[0025] The molar ratio of the 3-benzylmercaptothiocarbonyl propionic acid and the compound shown in formula II is (4-4.2):1.

[0026] According to the present application, preferably, in step (3) and step (4), the method for forming protective gas environment in the reactor is: a. freeze the reactor in liquid nitrogen, after the material in the reactor is frozen, vacuumize the reactor to discharge air, then dissolve the material in the reactor in water bath, after dissolution, fill the protective gas into the reactor; b. repeat step a for several times, then seal the reactor.

[0027] In the present application, preferably, step a is repeated for three times.

[0028] According to the present application, preferably, in step (3), the first initiator is 2,2'-azobis(2-methylpropionitrile); the third solvent is dioxane; the reaction temperature is 65-75℃; the molar ratio of the compound shown in formula III, 2-methyl-2-propenoic acid-2,3-dihydroxypropyl ester and the first initiator is 1:(640-660):(1-3).

[0029] According to the present application, preferably, in step (4), the second initiator is 2,2'-azobis(2-methylpropionitrile); the fourth solvent is ethanol aqueous solution; the reaction temperature is 65-75℃; the molar ratio of the polymer shown in formula IV, glycidyl methacrylate and the second initiator is 1:(640-660):(1-3).

[0030] Preferably, in the aqueous ethanol solution, the volume ratio of ethanol to water is 6:4.

[0031] The third aspect of the present application provides application of the above-mentioned additive or the additive prepared by the above-mentioned preparation method in preparation of a polymer cement-based waterproof coating.

[0032] In the present application, by designing the molecular arm structure, using the RAFT strategy and emulsion polymerization method, an amphiphilic additive rich in epoxy and hydroxyl functional groups and having a special star structure is synthesized; the additive is used in different types of JS waterproof coating, which effectively improves the drying speed of the JS waterproof coating.

[0033] The principle of improving the drying speed of the present application is that as an amphiphilic polymer, the molecules of the additive of the present application exhibit hydrophilic and hydrophobic ends in the coating, and a large number of hydroxyl functional groups contained in the hydrophilic end enrich water molecules, so that the water molecules on the surface of the coating film are unevenly distributed, and the water molecules with less distribution volatilize faster, thereby accelerating the overall volatilization rate of the coating film.

[0034] The fourth aspect of the present application provides a polymer cement-based waterproof coating, which comprises: a liquid material and a powder material.

[0035] The liquid material comprises, in mass fraction: 50-100 parts of a polymer emulsion, 0-0.5 parts of a defoaming agent, 0-0.5 parts of a mildew-proof agent, and 1-20 parts, preferably 10-15 parts, of the above-mentioned additive or the additive prepared by the above-mentioned preparation method.

[0036] The powder material comprises, in mass fraction: 10-70 parts of cement, 30-90 parts of a filler, and 0.1-1 parts of a water reducing agent.

[0037] Preferably, in the present application, when the polymer cement-based waterproof coating is applied, the liquid material and the powder material are mixed in a weight ratio of 1:(1-2).

[0038] According to the present application, preferably, the polymer emulsion is at least one of a styrene-acrylic emulsion, a butadiene-styrene emulsion, a vinyl acetate emulsion, and a vinyl tertiary propylene emulsion.

[0039] The technical solution of the present application has the following beneficial effects:

[0040] (1) The additive of the present application added to the polymer cement-based waterproof coating can improve the drying speed of the polymer cement-based waterproof coating.

[0041] (2) The application takes the drying speed improvement of JS waterproof coating as the functional orientation, an amphiphilic polymer particle additive with a functional molecular arm is synthesized through molecular arm design and is applied to JS waterproof coating based on styrene-acrylic, styrene-butadiene, vinyl-acrylic and tertiary butyl-acrylic emulsion, which obviously shortens the drying time of JS waterproof coating and improves the drying speed of JS waterproof coating.

[0042] (3) The application provides a reference for the structure design and mechanism research of related functional oriented polymer particles, and provides a train of thought for the drying speed improvement of related JS waterproof coating and the research and development of fast-drying JS waterproof coating.

[0043] Other features and advantages of the application will be described in detail in the following specific embodiments. DETAILED DESCRIPTION

[0044] The preferred embodiments of the application will be described in more detail below. Although the preferred embodiments of the application are described below, it should be understood that the application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the application more thorough and complete, and to fully convey the scope of the application to those skilled in the art.

[0045] The application will be further illustrated by the following examples:

[0046] In the following examples and comparative examples: the styrene-acrylic emulsion used is purchased from BASF, with the trade name Acronal 7588; the styrene-butadiene emulsion is purchased from BASF, with the trade name Acronal ECO 7813, the vinyl-acrylic emulsion is purchased from Celanese, with the trade name LDM2301; the tertiary butyl-acrylic emulsion is purchased from BATF, with the trade name RS-9967;

[0047] BIT mildew inhibitor is 1,2-benzisothiazolin-3-one;

[0048] Cement is ordinary portland cement No. 32.5;

[0049] Heavy calcium carbonate has an average particle size of 280 mesh

[0050] The average particle size of sand is 60-120 mesh.

[0051] Example 1

[0052] As shown in the synthesis process line formula 1, the application provides an additive for improving the drying speed of polymer cement-based waterproof coating, and the specific preparation method is as follows:

[0053] 1. Synthesis of reversible-addition chain transfer core monomer (product 2):

[0054] Tetramethyltetraethenylcyclotetrasiloxane (3.45 g, 0.010 mol), 3-mercapto-1-propanol (4.42 g, 0.048 mol) and 2,2-dimethoxy-2-phenylacetone (DMPA, 0.51 g, 0.020 mol) dissolved in tetrahydrofuran (50 mL) were introduced into a Schlenk flask with a magnetic stirrer. The solution was degassed to remove oxygen, and then irradiated under ultraviolet light (UV, 365 nm) at room temperature for 15 minutes. The crude product was precipitated in n-hexane and vacuum dried at room temperature, and the product 1 was obtained after purification by column chromatography.

[0055] Under argon atmosphere, 3-benzylmercaptothiocarbonylpropanoic acid (BSPA, 1.31 g, 4.8 mmol) and dichloromethane (20 mL) were introduced into a flask with a magnetic stirrer, and then oxalyl chloride (1.7 mL, 20.0 mmol) dissolved in dichloromethane was added dropwise into the flask at room temperature 25°C, and the mixture was stirred for 6 hours. The remaining oxalyl chloride and dichloromethane were removed by rotary evaporation under vacuum. Product 1 (0.856 g, 1.2 mmol) dissolved in tetrahydrofuran (20 mL) was poured into the above flask, and the mixture was stirred under argon atmosphere at room temperature 25°C for 24 hours. After removing the tetrahydrofuran, product 2 was obtained by purification by column chromatography.

[0056] 2. Introduction of molecular arm hydrophilic block:

[0057] Product 2 (0.19 g, 0.11 mmol), 2-methyl-2-propenoic acid-2,3-dihydroxypropyl ester (11.53 g, 72 mmol), 2,2'-azobis(2-methylpropionitrile) (AIBN, 0.025 g, 0.15 mmol) and dioxane (11 mL) were weighed into a glass reaction tube, and a magnetic stirrer was added; then, the glass reaction tube was subjected to freeze-thaw cycle (vacuum / argon) treatment: the glass reaction tube was frozen in liquid nitrogen, and after the contents of the reactor were frozen, the reactor was vacuumed for 7 min to remove air, and then the reactor was placed in a water bath to dissolve the contents, and after dissolution, the reactor was filled with argon; after repeating the freeze-thaw cycle (vacuum / argon) three times, the sintered glass reaction tube was sealed; finally, the reactor was heated and stirred in an oil bath at 70°C for 90 min; after quenching in an ice bath, the tube was opened, and the polymer was precipitated in diethyl ether, and after vacuum drying at 30°C, polymer 1 was obtained, and the specific structure of polymer 1 is shown in formula IV, and n in each R3 in formula IV is 159.

[0058] 3. Introduction of molecular arm hydrophobic block: 1. Take polymer 1 (11.6 g, 0.11 mmol), glycidyl methacrylate (10.24 g, 72 mmol), 2,2'-azobis(2-methylpropionitrile) (0.025 g, 0.15 mmol) and ethanol aqueous solution (ethanol / water volume ratio 6 / 4, 40 mL) in a glass reaction tube, and add a magnet; then, perform freeze-thaw cycle (with vacuum / argon filling) treatment: freeze the glass reaction tube in liquid nitrogen, and after the material in the reactor is frozen, vacuum the reactor for 7 min to exhaust air, and then dissolve the material in the reactor in a water bath, and after dissolution, fill argon into the reactor; after repeating the above freeze-thaw cycle (with vacuum / argon filling) three times, sinter the glass reaction tube; finally, heat and stir the reaction in a 70°C oil bath for 90 min; after quenching in an ice bath, open the tube, and dialyze in deionized water for 2 d to obtain the target additive (hereinafter referred to as additive 1). The specific structure of the additive 1 is shown in formula I, and m in each R in formula I is 159, and n is 159.

[0059]

[0060] Synthetic process route formula 1

[0061] In formula 1, the structural formulas of product 1, product 2, polymer 1 and additive 1 are omitted, and the specific structural formulas of product 1, product 2, polymer 1 and additive 1 are shown in formula II, formula III, formula IV and formula I respectively.

[0062] Examples 2-9

[0063] Examples 2-9 provide a JS waterproof coating, and the specific formula is shown in Table 1, and the specific preparation method is as follows:

[0064] Mix the emulsion, defoaming agent, mildew-proof agent and additive 1 to obtain a liquid material; mix the filler, cement and water reducing agent to obtain a powder material.

[0065] Table 1 Waterproof coating formula of examples 2-9 in the application (the amount is mass fraction)

[0066]

[0067]

[0068] Comparative examples 1-5

[0069] Comparative examples 1-5 provide a waterproof coating, and the specific formula is shown in Table 2, and the specific preparation method is as follows: mix the components of the liquid material to obtain a liquid material; mix the components of the powder material to obtain a powder material.

[0070] Table 2 Waterproof coating formula of comparative examples 1-5 in the application (the amount is mass fraction)

[0071]

[0072]

[0073] Comparative Example 5-13

[0074] Comparative Example 5-13 provides a waterproof coating, the specific formula is shown in Table 3, and the specific preparation method is as follows: the components of the liquid material are mixed to obtain a liquid material; the components of the powder material are mixed to obtain a powder material.

[0075] Table 3 Waterproof coating formula of Comparative Example 5-13 in the application (all amounts are parts by mass)

[0076]

[0077] Test Example

[0078] The waterproof coatings prepared in the above examples and comparative examples are tested for performance (the liquid material and the powder material components are mixed according to a weight ratio of 1:1.8), and the specific test results are shown in the following table; wherein the tensile strength, elongation at break and adhesion strength are tested according to the standard GB / T 23445-2009 “Polymer Cement Waterproof Coating”.

[0079] The specific method for testing the drying speed is as follows: under standard conditions (temperature 23±2℃ and humidity 50±10%), a mixed and uniform coating sample is coated on an aluminum plate with a wire rod applicator to prepare a coating film, the coating area is (100×50) mm, the coating end time is recorded, after standing for a period of time, the coating film is cut with a blade within a range of not less than 10 mm from the edge of the test piece, if there is no finger sticking phenomenon in the bottom layer and the film, it is considered to be dry, and the time is recorded.

[0080] Table 4 Dry time and physical and mechanical properties of JS waterproof coating in the application

[0081] Example Tack-free time (23°C, 50%) Tensile strength (MPa) Elongation at break (%) Adhesion strength (MPa) Example 2 2h 10min 2.5 128 1.4 Example 3 2h 30min 3.0 89 1.8 Example 4 2h 8min 2.6 110 1.4 Example 5 2h 45min 2.8 104 1.5 Example 6 3h 30min 2.3 137 1.2 Example 7 1h 30min 2.5 126 1.4 Example 8 1h 20min 2.6 115 1.8 Example 9 1h 20min 2.8 108 1.8 Comparative Example 1 3h 40min 2.3 140 1.2 Comparative Example 2 3h 30min 2.8 96 1.7 Comparative Example 3 3h 10min 2.5 122 1.3 Comparative Example 4 4h 2.6 113 1.4

[0082] As can be seen from Table 4, the dry time of the JS waterproof coating of various emulsions with the aid 1 of the application is shortened to different degrees. Further according to the results of Examples 2, 6-9, it can be seen that when the amount of the aid is small (1 part), the drying speed is not obviously improved, and as the amount of the aid 1 increases, the drying speed is significantly accelerated. According to Examples 8 and 9, when the amount of the aid 1 is increased to more than 15 parts, the drying speed is no longer improved.

[0083] Table 5 Dry time and physical and mechanical properties of JS waterproof coating in Comparative Example 5-13

[0084]

[0085]

[0086] From Table 5, it can be seen that the effect of the additive 1 on the drying speed of the emulsion is further verified by selecting the styrene-acrylic emulsion. According to the comparative examples 5 and 6, the additive 1 has the effect of improving the drying speed of the styrene-acrylic emulsion, and the real drying time is shortened by 33%. According to the results of the comparative examples 7 and 8, the addition of the defoaming agent and the mildew-proof agent cannot improve the drying speed of the styrene-acrylic emulsion. According to the comparative examples 1, 9 and 10, the additive 1 has the effect of improving the drying speed of the pure styrene-acrylic emulsion and the JS waterproof coating. According to the test results of the comparative examples 11-13, the cement proportion and the addition amount of the water reducing agent have little effect on the drying speed, and have an effect on the physical and mechanical properties.

[0087] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An additive for improving the drying speed of a polymer cement-based waterproofing coating, characterized in that, The auxiliary agent is shown as formula I; wherein, m is an integer of 155-159, n is an integer of 155-159; In formula I, R is 2. A process for the preparation of the adjuvant of claim 1, characterized in that, The preparation method comprises: (1) in the presence of a first solvent and a photoinitiator, tetramethyltetra-vinylcyclotetrasiloxane and 3-mercapto-1-propanol are subjected to a photoinitiation reaction to obtain a compound shown as formula II; (2) in the presence of a protective gas and a second solvent, 3-benzyl mercaptothiocarbonyl propionic acid and oxalyl chloride are subjected to a reaction, the second solvent and residual oxalyl chloride are removed; then a solution of the compound shown as formula II is added, and in the presence of the protective gas, a stirring reaction is carried out to obtain a compound shown as formula III; (3) the compound shown as formula III, 2-methyl-2-propenoic acid-2,3-dihydroxypropyl ester, a first initiator and a third solvent are added into a reactor, a protective gas environment is formed in the reactor; then the materials in the reactor are subjected to a reaction under the conditions of heating and stirring to obtain a polymer shown as formula IV; (4) the polymer shown as formula IV, glycidyl methacrylate, a second initiator and a fourth solvent are added into a reactor, a protective gas environment is formed in the reactor; then the materials in the reactor are subjected to a reaction under the conditions of heating and stirring to obtain the auxiliary agent; In formula II, R1is In formula III, R2is In formula IV, R3is n is an integer from 155 to 159.

3. The method of making according to claim 2, wherein, In step (1), the first solvent is tetrahydrofuran; the photoinitiator is 2,2-dimethoxy-2-phenylpropanone; the photoinitiation reaction is carried out under ultraviolet light irradiation; The molar ratio of the tetramethyltetra-vinylcyclotetrasiloxane, 3-mercapto-1-propanol and the photoinitiator is 1:(4-5):

2.

4. The production method according to claim 2, wherein In step (2), the protective gas is argon; the second solvent is dichloromethane; the solution of the compound shown as formula II is a tetrahydrofuran solution of the compound shown as formula II; The reaction of the 3-benzyl mercaptothiocarbonyl propionic acid and the oxalyl chloride is carried out at 20-30℃; the stirring reaction is carried out at 20-30℃; The molar ratio of the 3-benzyl mercaptothiocarbonyl propionic acid and the oxalyl chloride is 1:(4-4.2); The molar ratio of the 3-benzyl mercaptothiocarbonyl propionic acid and the compound shown as formula II is (4-4.2):

1.

5. The production method according to claim 2, wherein In steps (3) and (4), the method for forming the protective gas environment in the reactor is: a. the reactor is frozen in liquid nitrogen, after the materials in the reactor are frozen, the reactor is vacuumized to discharge air, then the reactor is dissolved in a water bath, after dissolution, the reactor is filled with the protective gas; b. step a is repeated for multiple times, then the reactor is closed.

6. The production method according to claim 2, wherein In step (3), the first initiator is 2,2'-azobis(2-methylpropionitrile); the third solvent is dioxane; the temperature of the reaction is 65-75℃; the molar ratio of the compound shown as formula III, 2-methyl-2-propenoic acid-2,3-dihydroxypropyl ester and the first initiator is 1:(640-660):(1-3).

7. The production method according to claim 2, wherein In step (4), the second initiator is 2,2'-azobis(2-methylpropionitrile); the fourth solvent is an ethanol aqueous solution; the reaction temperature is 65-75℃; the molar ratio of the polymer of formula IV, glycidyl methacrylate, and the second initiator is 1:(640-660):(1-3).

8. Use of the adjuvant of claim 1 or prepared by the method of any one of claims 2-7 in the preparation of a polymer cement-based waterproof coating.

9. A polymer cement-based waterproofing coating, characterized by, The waterproof coating comprises: a liquid material and a powder material; The liquid material comprises, in parts by mass: 50-100 parts of a polymer emulsion; 0-0.5 parts of an antifoaming agent; 0-0.5 parts of a mildew-proof agent; 1-20 parts, preferably 10-15 parts, of the adjuvant of claim 1 or prepared by the method of any one of claims 2-7; The powder material comprises, in parts by mass: 10-70 parts of cement; 30-90 parts of a filler; and 0.1-1 parts of a water reducing agent.

10. The water repellent coating according to claim 9, wherein, The polymer emulsion is at least one of a styrene-acrylic emulsion, a styrene-butadiene emulsion, a vinyl acetate emulsion, and a vinyl tertiary propylene emulsion.

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