CN111876062A - Waterproof coating for wall surface and preparation method thereof - Google Patents

Abstract

The invention discloses a waterproof coating for a wall surface, which is prepared from the following raw materials in parts by weight: 35-50 parts of modified organic silicon composite emulsion, 10-15 parts of titanium dioxide, 0.1-0.5 part of dispersing agent, 20-30 parts of propylene glycol, 100 parts of 110 parts of water, 1-3 parts of thickening agent and 3-5 parts of nano calcium carbonate; the invention also discloses a preparation method of the waterproof coating for the wall surface; in the preparation process of the modified organic silicon composite emulsion, polyurethane contains strong polar groups, so that the modified organic silicon composite emulsion has good fire resistance and water resistance, and organic silicon sol has strong hydrophobicity and stability, so that the composite emulsion can be endowed with excellent waterproof and stable performances; and the nano calcium carbonate is used as a filler and can be used as a framework in a system, so that the stability of the prepared waterproof coating is further enhanced.

Description

Waterproof coating for wall surface and preparation method thereof

Technical Field

The invention belongs to the technical field of waterproof coatings, and particularly relates to a waterproof coating for a wall surface and a preparation method thereof.

Background

A layer of film is formed on the surface of a building through volatilization of a solvent or moisture or a chemical reaction of two components, so that the surface of the building is isolated from water, and the waterproof and sealing effects are achieved; although the concrete structure position of a roof, a toilet, a balcony and a pipeline joint is coated with the conventional waterproof coating, once the concrete cracks, the water leakage phenomenon at the cracks still occurs because the existing common waterproof coating has poor impermeability, weak adhesive force, poor flexibility and poor overall elasticity and elongation.

The Chinese patent CN103351769A discloses an acrylate single-component waterproof coating, which comprises the following components in parts by weight: 50-70 parts of acrylic emulsion, 0.02-0.04 part of preservative, 5-7 parts of heavy calcium carbonate, 10-20 parts of titanium dioxide, 0.1-0.3 part of thickening agent, 3-6 parts of dibutyl ester, 0.04-0.06 part of ammonia neutralizer, 2-4 parts of cellulose, 0.01-0.03 part of defoaming agent, 6-8 parts of water and 1-2 parts of filler. The single-component high polymer water-based waterproof coating is prepared by adding high-quality p filler and an auxiliary agent into pure acrylate emulsion, has good impermeability, cohesive force and flexibility, and integral elasticity and elongation, and can realize the effect of no water seepage due to 2-3mm wide cracking of concrete when the waterproof coating is coated.

Disclosure of Invention

In order to overcome the technical problems, the invention provides a waterproof coating for a wall surface and a preparation method thereof.

The technical problems to be solved by the invention are as follows:

the silica sol has good high temperature resistance and oxidation resistance, but a large amount of hydroxyl exists on the surface of the nano calcium carbonate, so that when the silica sol is copolymerized with other substances, the silicon dioxide is easy to agglomerate, and a stable system is difficult to form.

The purpose of the invention can be realized by the following technical scheme:

a waterproof coating for a wall surface is prepared from the following raw materials in parts by weight: 35-50 parts of modified organic silicon composite emulsion, 10-15 parts of titanium dioxide, 0.1-0.5 part of dispersing agent, 20-30 parts of propylene glycol, 100 parts of 110 parts of water, 1-3 parts of thickening agent and 3-5 parts of nano calcium carbonate;

the waterproof coating for the wall surface is prepared by the following method:

firstly, mixing a dispersing agent and water, and stirring for 15-20min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding a thickening agent, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

Further, the modified organic silicon composite emulsion is prepared by the following method:

(1) putting the silica sol into a beaker, continuously adding 3g of sodium hydroxide, stirring for 5min, heating in a water bath at 60 ℃ for 2h, adding 10mL of methyl trioxyethylsilane, carrying out ultrasonic treatment for 30min, standing for reaction for 2h to obtain the silica sol, and controlling the weight ratio of the silica sol to the sodium hydroxide to the methyl trioxyethylsilane to be 5: 1: 10;

(2) adding sodium dodecyl sulfate and octylphenol polyoxyethylene ether into a beaker filled with deionized water, uniformly mixing, stirring for 30min by using a magnetic stirrer, adding polyurethane after stirring, and continuously stirring for 20min to prepare pre-emulsified polyurethane, wherein the weight ratio of the sodium dodecyl sulfate to the octylphenol polyoxyethylene ether to the deionized water to the polyurethane is controlled to be 3: 2: 25-30: 5;

(3) adding deionized water, sodium carbonate and epichlorohydrin into a four-neck flask, heating to 80 ℃, uniformly stirring, reacting for 30min, heating to 85 ℃, adding pre-emulsified polyurethane and half of 10% by mass of potassium persulfate aqueous solution, reacting for 45min at the temperature, heating to 90 ℃, continuously adding the other half of 10% by mass of potassium persulfate aqueous solution, reacting for 3h at the temperature, standing for 1h after the reaction is finished, and adding sodium hydroxide and organic silica sol to prepare the modified organic silicon composite emulsion, wherein the weight ratio of the deionized water, the sodium carbonate, the epichlorohydrin, the pre-emulsified polyurethane, the 10% by mass of potassium persulfate aqueous solution, the sodium hydroxide and the organic silica sol is controlled to be 100: 0.5: 2: 10: 3: 0.1: 8.

The silica sol has good high temperature resistance and oxidation resistance, but a large number of hydroxyl groups exist on the surface of the nano calcium carbonate, so that when the silica sol is copolymerized with other substances, the silica is easy to agglomerate, and a stable system is difficult to form; and (3) mixing the organic silica sol and the pre-emulsified polyurethane to prepare a composite emulsion, wherein the polyurethane contains strong polar groups, so that the polyurethane has good fire resistance and water resistance, and the organic silica sol has strong hydrophobicity and stability, so that the composite emulsion can be endowed with excellent waterproof and stable performances.

Further, the dispersing agent is one or two of barium stearate and polyethylene wax.

Further, the thickening agent is one or more of gelatin, polyvinylpyrrolidone and polyacrylate copolymer emulsion.

Further, the silica sol is liquid silica sol with the silica content of 10% -60%, and the particle size of the silica is 100 nm.

A preparation method of waterproof paint for wall surfaces comprises the following steps:

firstly, mixing a dispersing agent and water, and stirring for 15-20min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding a thickening agent, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

The invention has the beneficial effects that:

the invention relates to a waterproof coating for a wall surface, which is prepared from raw materials such as modified organic silicon composite emulsion and titanium dioxide, wherein in the preparation process of the modified organic silicon composite emulsion, step (1) is to modify silica sol through methyl trioxyethyl silane, the methyl trioxyethyl silane is subjected to hydrolytic condensation reaction in the modification process, and then is subjected to crosslinking reaction with a large amount of hydroxyl groups on the surface of silicon dioxide to wrap silica sol particles, and an Si-O-Si structure contains organic groups, so that the silicon dioxide particles are uniformly dispersed in the emulsion to increase the hydrophobicity and stability of the silica sol; mixing the organic silica sol and the pre-emulsified polyurethane in the step (3) to prepare a composite emulsion, wherein the polyurethane contains strong polar groups, so that the polyurethane has good fire resistance and water resistance, and the organic silica sol has strong hydrophobicity and stability, so that the composite emulsion can be endowed with excellent waterproof and stable performances; and the nano calcium carbonate is used as a filler and can be used as a framework in a system, so that the stability of the prepared waterproof coating is further enhanced.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A waterproof coating for a wall surface is prepared from the following raw materials in parts by weight: 35 parts of modified organic silicon composite emulsion, 10 parts of titanium dioxide, 0.1 part of barium stearate, 20 parts of propylene glycol, 100 parts of water, 1 part of polyvinylpyrrolidone and 3 parts of nano calcium carbonate;

the waterproof coating for the wall surface is prepared by the following method:

step one, mixing barium stearate and water and stirring for 15min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding polyvinylpyrrolidone, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

The modified organic silicon composite emulsion is prepared by the following method:

(1) putting the silica sol into a beaker, continuously adding 3g of sodium hydroxide, stirring for 5min, heating in a water bath at 60 ℃ for 2h, adding 10mL of methyl trioxyethylsilane, carrying out ultrasonic treatment for 30min, standing for reaction for 2h to obtain the silica sol, and controlling the weight ratio of the silica sol to the sodium hydroxide to the methyl trioxyethylsilane to be 5: 1: 10;

(2) adding sodium dodecyl sulfate and octylphenol polyoxyethylene ether into a beaker filled with deionized water, uniformly mixing, stirring for 30min by using a magnetic stirrer, adding polyurethane after stirring, and continuously stirring for 20min to prepare pre-emulsified polyurethane, wherein the weight ratio of the sodium dodecyl sulfate to the octylphenol polyoxyethylene ether to the deionized water to the polyurethane is controlled to be 3: 2: 25: 5;

(3) adding deionized water, sodium carbonate and epichlorohydrin into a four-neck flask, heating to 80 ℃, uniformly stirring, reacting for 30min, heating to 85 ℃, adding pre-emulsified polyurethane and half of 10 mass percent potassium persulfate aqueous solution, reacting for 45min at the temperature, heating to 90 ℃, continuously adding the other half of 10 mass percent potassium persulfate aqueous solution, reacting for 3h at the temperature, standing for 1h after the reaction is finished, and adding sodium hydroxide and organic silica sol to prepare the modified organic silicon composite emulsion, wherein the weight ratio of the deionized water, the sodium carbonate, the epichlorohydrin, the pre-emulsified polyurethane, the 10 percent of potassium persulfate aqueous solution, the sodium hydroxide and the organic silica sol is controlled to be 100: 0.5: 2: 10: 3: 0.1: 8.

Example 2

A waterproof coating for a wall surface is prepared from the following raw materials in parts by weight: 40 parts of modified organic silicon composite emulsion, 12 parts of titanium dioxide, 0.3 part of barium stearate, 22 parts of propylene glycol, 102 parts of water, 2 parts of polyvinylpyrrolidone and 4 parts of nano calcium carbonate;

the waterproof coating for the wall surface is prepared by the following method:

firstly, mixing barium stearate and water, stirring for 15min at the rotating speed of 120r/min to prepare a mixed solution A,

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding polyvinylpyrrolidone, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

Example 3

A waterproof coating for a wall surface is prepared from the following raw materials in parts by weight: 45 parts of modified organic silicon composite emulsion, 14 parts of titanium dioxide, 0.3 part of barium stearate, 26 parts of propylene glycol, 108 parts of water, 2 parts of polyvinylpyrrolidone and 4 parts of nano calcium carbonate;

the waterproof coating for the wall surface is prepared by the following method:

step one, mixing barium stearate and water and stirring for 15min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding polyvinylpyrrolidone, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

Example 4

A waterproof coating for a wall surface is prepared from the following raw materials in parts by weight: 50 parts of modified organic silicon composite emulsion, 15 parts of titanium dioxide, 0.5 part of barium stearate, 30 parts of propylene glycol, 110 parts of water, 3 parts of polyvinylpyrrolidone and 5 parts of nano calcium carbonate;

the waterproof coating for the wall surface is prepared by the following method:

step one, mixing barium stearate and water and stirring for 15min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding polyvinylpyrrolidone, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

Comparative example 1

Compared with the example 1, the preparation method of the comparative example, which replaces the modified organosilicon composite emulsion with the organosilicon emulsion, is as follows:

step one, mixing barium stearate and water and stirring for 15min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the organic silicon emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding polyvinylpyrrolidone, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

Comparative example 2

This comparative example is a water-resistant coating in the market.

The workability, water resistance and weather resistance of examples 1 to 4 and comparative examples 1 to 2 were examined, and the results are shown in the following table;

water resistance: the water resistance of examples 1 to 4 and comparative examples 1 to 2 was examined in accordance with GB/T1733 to 93;

weather resistance: GB/T1865-89 stipulates that a 6000W water-cooled tubular xenon lamp is adopted, the distance between a sample plate and a light source is 350-400 mm, the air temperature of a laboratory is 45 +/-2 ℃, the relative humidity is 70 +/-5%, the rainfall period is 12min per hour, the sample plate is inspected once every 48 hours in the early stage, and is inspected once every 96 hours after 192 hours. And (3) each time the position of the test plate is checked and changed until reaching any one of 'poor' in GB/T1766-95 paint film weather resistance comprehensive rating method, terminating the test and observing the time required for reaching the 'poor'.

	Workability	Water resistance	Weather resistance
				Example 1	Two-pass painting	No abnormality	1012h
Example 2	Two-pass painting	No abnormality	1018h
				Example 3	Two-pass painting	No abnormality	1015h
Example 4	Two-pass painting	No abnormality	1022h
				Comparative example 1	Apply a brush in one	Falling off	912h
Comparative example 2	Apply a brush in one	Falling off	885h

From the above table, it can be seen that the coating of examples 1-4 has no obstacle for two passes, no abnormality in the water resistance test, the time required for reaching the difference level in the weather resistance test is 1012-912 h, the coating of comparative examples 1-2 has no obstacle, the peeling occurs in the water resistance test, and the time required for reaching the difference level in the weather resistance test is 885-912 h; the polyurethane contains strong polar groups, so that the polyurethane has good fire resistance and water resistance, and the organic silica sol has strong hydrophobicity and stability, so that the composite emulsion can be endowed with excellent waterproof and stable performances; and the nano calcium carbonate is used as a filler and can be used as a framework in a system, so that the stability of the prepared waterproof coating is further enhanced.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.

Claims (6)

1. The waterproof coating for the wall surface is characterized by being prepared from the following raw materials in parts by weight: 35-50 parts of modified organic silicon composite emulsion, 10-15 parts of titanium dioxide, 0.1-0.5 part of dispersing agent, 20-30 parts of propylene glycol, 100 parts of 110 parts of water, 1-3 parts of thickening agent and 3-5 parts of nano calcium carbonate;

the waterproof coating for the wall surface is prepared by the following method:

firstly, mixing a dispersing agent and water, and stirring for 15-20min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding a thickening agent, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.

2. The waterproof coating for the wall surface, according to claim 1, is characterized in that the modified organosilicon composite emulsion is prepared by the following method:

(1) putting the silica sol into a beaker, continuously adding 3g of sodium hydroxide, stirring for 5min, heating in a water bath at 60 ℃ for 2h, adding 10mL of methyl trioxyethylsilane, carrying out ultrasonic treatment for 30min, standing for reaction for 2h to obtain the silica sol, and controlling the weight ratio of the silica sol to the sodium hydroxide to the methyl trioxyethylsilane to be 5: 1: 10;

(2) adding sodium dodecyl sulfate and octylphenol polyoxyethylene ether into a beaker filled with deionized water, uniformly mixing, stirring for 30min by using a magnetic stirrer, adding polyurethane after stirring, and continuously stirring for 20min to prepare pre-emulsified polyurethane, wherein the weight ratio of the sodium dodecyl sulfate to the octylphenol polyoxyethylene ether to the deionized water to the polyurethane is controlled to be 3: 2: 25-30: 5;

(3) adding deionized water, sodium carbonate and epichlorohydrin into a four-neck flask, heating to 80 ℃, uniformly stirring, reacting for 30min, heating to 85 ℃, adding pre-emulsified polyurethane and half of 10% potassium persulfate aqueous solution, reacting for 45min at the temperature, heating to 90 ℃, continuously adding the other half of 10% potassium persulfate aqueous solution, reacting for 3h at the temperature, standing for 1h after the reaction is finished, and adding sodium hydroxide and organic silica sol to prepare the modified organic silicon composite emulsion, wherein the weight ratio of the deionized water, the sodium carbonate, the epichlorohydrin, the pre-emulsified polyurethane, the 10% of potassium persulfate aqueous solution, the sodium hydroxide and the organic silica sol is controlled to be 100: 0.5: 2: 10: 3: 0.1: 8.

3. The waterproof paint for wall surfaces as claimed in claim 1, wherein the dispersant is one or both of barium stearate and polyethylene wax.

4. The waterproof paint for the wall surface as claimed in claim 1, wherein the thickener is one or more of gelatin, polyvinylpyrrolidone and polyacrylate copolymer emulsion.

5. The waterproof paint for the wall surface according to claim 2, wherein the silica sol is a liquid silica sol containing 10% -60% of silica, and the particle size of the silica is 100 nm.

6. The method for preparing the waterproof coating for the wall surface according to claim 1, characterized by comprising the following steps:

firstly, mixing a dispersing agent and water, and stirring for 15-20min at a rotating speed of 120r/min to prepare a mixed solution A;

and secondly, adding the modified organic silicon composite emulsion, the nano calcium carbonate and the titanium dioxide into propylene glycol to form a liquid mixture B, pouring the liquid mixture B into a ball mill, carrying out high-speed ball milling at the rotating speed of 1500r/min, transferring the mixture into the mixed solution A after carrying out ball milling for 15min, adding a thickening agent, heating in a 70 ℃ water bath, magnetically stirring for 30min, and standing for 2h to obtain the waterproof coating for the wall surface.