阅读说明：本技术 一种水性聚脲复合改性单组分丙烯酸防水涂料及制备方法 (Water-based polyurea composite modified single-component acrylic acid waterproof coating and preparation method thereof ) 是由 宋爽 薛文军 于 2021-07-09 设计创作，主要内容包括：本发明涉及防水涂料技术领域,尤其涉及一种水性聚脲复合改性单组分丙烯酸防水涂料及制备方法。方法包括：石墨烯在去离子水中超声分散45～70min,得到石墨烯水性分散液；将石墨烯水性分散液依次加入分散剂、消泡剂、防霉剂,在搅拌速度800～1000r/min下,金红石型二氧化钛和无机填料,持续搅拌25～35min；再依次加入丙烯酸乳液和水性聚脲乳液,降低搅拌速度至400～600r/min,持续搅拌25～35min,静置得到水性聚脲复合改性单组分丙烯酸防水涂料。通过丙烯酸乳液改性水性聚脲乳液,并结合石墨烯和其它配料发挥协同作用,极大的提高防水涂料的力学性能,并克服了其吸水率高的问题。(The invention relates to the technical field of waterproof coatings, in particular to a water-based polyurea composite modified single-component acrylic waterproof coating and a preparation method thereof. The method comprises the following steps: carrying out ultrasonic dispersion on graphene in deionized water for 45-70 min to obtain a graphene aqueous dispersion liquid; sequentially adding a dispersing agent, a defoaming agent and a mildew preventive into the graphene aqueous dispersion liquid, and continuously stirring rutile titanium dioxide and inorganic filler at a stirring speed of 800-1000 r/min for 25-35 min; and sequentially adding the acrylic emulsion and the water-based polyurea emulsion, reducing the stirring speed to 400-600 r/min, continuously stirring for 25-35 min, and standing to obtain the water-based polyurea composite modified single-component acrylic waterproof coating. The acrylic emulsion is used for modifying the aqueous polyurea emulsion, and the graphene and other ingredients are combined to play a synergistic effect, so that the mechanical property of the waterproof coating is greatly improved, and the problem of high water absorption rate is solved.)

1. A preparation method of a water-based polyurea composite modified single-component acrylic acid waterproof coating is characterized by comprising the following steps:

s1, ultrasonically dispersing graphene in deionized water for 45-70 min to obtain a graphene aqueous dispersion liquid;

s2, sequentially adding a dispersing agent, a defoaming agent and a mildew preventive into the graphene aqueous dispersion liquid, and continuously stirring the rutile type titanium dioxide and the inorganic filler for 25-35 min at a stirring speed of 800-1000 r/min;

and S3, sequentially adding the acrylic emulsion and the water-based polyurea emulsion, reducing the stirring speed to 400-600 r/min, continuously stirring for 25-35 min, and standing to obtain the water-based polyurea composite modified single-component acrylic waterproof coating.

2. The method for preparing the aqueous polyurea composite modified single-component acrylic waterproof coating according to claim 1, wherein the aqueous polyurea composite modified single-component acrylic waterproof coating comprises the following steps: 0.1-1 part of graphene, 2-6 parts of deionized water, 0.2-0.5 part of dispersing agent, 0.5-1 part of defoaming agent, 5-10 parts of rutile titanium dioxide, 30-35 parts of inorganic filler, 0-0.1 part of mildew preventive, 45-50 parts of acrylic emulsion and 5-10 parts of water-based polyurea emulsion.

3. The method for preparing the aqueous polyurea composite modified single-component acrylic waterproof coating according to claim 1, wherein the aqueous polyurea composite modified single-component acrylic waterproof coating comprises the following steps: the acrylic emulsion is pure acrylic waterproof emulsion with the glass transition temperature of-20 ℃.

4. The method for preparing the aqueous polyurea composite modified single-component acrylic waterproof coating according to claim 1, wherein the aqueous polyurea composite modified single-component acrylic waterproof coating comprises the following steps: the water-based polyurea emulsion is water-based polyurea emulsion with the lowest film forming temperature of 0 ℃.

5. The method for preparing the aqueous polyurea composite modified single-component acrylic waterproof coating according to claim 1, wherein the aqueous polyurea composite modified single-component acrylic waterproof coating comprises the following steps: the defoaming agent is one or any combination of mineral oil defoaming agent and organic silicon defoaming agent.

6. The preparation method of the aqueous polyurea composite modified single-component acrylic acid waterproof coating material according to claim 1, wherein the inorganic filler is one or a combination of more than two of 800-mesh barium sulfate, 800-mesh heavy calcium carbonate, 800-mesh mica powder and 1000-mesh talcum powder.

7. The preparation method of the aqueous polyurea composite modified single-component acrylic waterproof coating as claimed in claim 1 comprises the following steps: the number of layers of the graphene is 1-3, and the graphene is graphene powder with the particle size of 7-12 mu m.

8. The aqueous polyurea composite modified single-component acrylic waterproof coating prepared by the preparation method of any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of waterproof coatings, in particular to a water-based polyurea composite modified single-component acrylic waterproof coating and a preparation method thereof.

Background

The aqueous polyurea composite modified single-component acrylic waterproof coating has excellent film forming property and low water absorption, can effectively deal with tiny gaps of a base layer, and ensures the continuity of a waterproof layer. Meanwhile, the adhesive has higher bonding strength with a base surface, and ensures that the product is not peeled and delaminated.

The traditional conventional single-component acrylic waterproof coating is prepared by mixing acrylic emulsion and inorganic filler serving as main components and adding functional additives, wherein the use and popularization of the materials are seriously influenced due to the performance limitation of the acrylic emulsion, more inorganic filler, low mechanical strength and high water absorption of the materials.

The publication No. CN202010702204.5 discloses a water-based EAU anticorrosive paint and a preparation method thereof, and the advantages of water-based EAU acrylic emulsion and graphene dispersion liquid are combined with the synergistic effect of other raw material components, so that the prepared anticorrosive paint has better acid resistance and weather resistance, the prepared paint can also play a better protection role on a base material in a relatively harsh environment, but the tensile strength of the prepared anticorrosive paint is still insufficient.

The publication number CN201810254270.3 discloses a preparation method of an anti-corrosion, anti-fouling and anti-protein aqueous polyurea grafted graphene coating material, which improves the strength of the coating by means of polyurea grafted acrylic acid. But the preparation process thereof is relatively complicated, resulting in an increase in cost.

Disclosure of Invention

Technical problem to be solved

In view of the defects and shortcomings of the prior art, the invention provides the aqueous polyurea composite modified single-component acrylic waterproof coating, which greatly improves the mechanical property of the waterproof coating and overcomes the problem of high water absorption rate by modifying the aqueous polyurea emulsion through the acrylic emulsion and combining the graphene and other ingredients to play a synergistic effect.

Correspondingly, the invention also provides a preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

in a first aspect, an embodiment of the present invention provides a preparation method of a water-based polyurea composite modified single-component acrylic waterproof coating, which includes the following steps:

s1, ultrasonically dispersing graphene in deionized water for 45-70 min to obtain a graphene aqueous dispersion liquid;

s2, sequentially adding a dispersing agent, a defoaming agent and a mildew preventive into the graphene aqueous dispersion liquid, and continuously stirring the rutile type titanium dioxide and the inorganic filler for 25-35 min at a stirring speed of 800-1000 r/min;

and S3, sequentially adding the acrylic emulsion and the water-based polyurea emulsion, reducing the stirring speed to 400-600 r/min, continuously stirring for 25-35 min, and standing to obtain the water-based polyurea composite modified single-component acrylic waterproof coating.

The method for compounding the acrylic emulsion with the aqueous polyurea emulsion utilizes the characteristics of excellent extensibility of the acrylic emulsion and low water absorption of the aqueous polyurea emulsion, and simultaneously adds the graphene powder which can be irregularly distributed in a coating system, and when the coating system is cured to form a film, the graphene with a lamellar structure can be fixed in a coating film structure, so that the lamellar structure can improve the shielding effect of the coating film and weaken the penetration capability of water molecules to the coating film, thereby reducing the water absorption of the coating film, further ensuring that the waterproof coating has excellent mechanical properties (tensile strength of 1.0MPa, elongation at break of 300 percent), higher solid content (65 percent) and extremely low water absorption, and greatly prolonging the waterproof life of a building.

In order to enable the obtained waterproof coating to have the lowest water absorption rate and the highest tensile strength, in an optional scheme of the preparation method, by weight, 0.1-1 part of graphene, 2-6 parts of deionized water, 0.2-0.5 part of a dispersing agent, 0.5-1 part of an antifoaming agent, 5-10 parts of rutile titanium dioxide, 30-35 parts of an inorganic filler, 0-0.1 part of a mildew preventive, 45-50 parts of an acrylic emulsion and 5-10 parts of a water-based polyurea emulsion.

In the optional scheme of the preparation method, the acrylic emulsion is pure acrylic waterproof emulsion with the glass transition temperature of-20 ℃; the mechanical property of the waterproof coating can be further improved.

In an optional scheme of the preparation method, the water-based polyurea emulsion is the water-based polyurea emulsion with the minimum film forming temperature of 0 ℃; the water absorption of the waterproof coating can be further reduced.

In an optional scheme of the preparation method, the defoaming agent is one or any combination of two of a mineral oil defoaming agent and an organic silicon defoaming agent.

In the optional scheme of the preparation method, the inorganic filler is one or the combination of more than two of 800-mesh barium sulfate, 800-mesh heavy calcium carbonate, 800-mesh mica powder and 1000-mesh talcum powder. The inorganic filler preferably selected by the invention can be uniformly combined with the macromolecular chains of the acrylic emulsion and the water-soluble polyurea emulsion, the mechanical property is ensured, the viscosity of the waterproof coating can be effectively controlled, and the construction smoothness is ensured.

In an optional scheme of the preparation method, the number of layers of the graphene is 1-3, and the graphene is graphene powder with the particle size of 7-12 mu m. Only when the graphene powder with the particle size of 7-12 mu m is applied to the coating, the graphene and other components can play a good synergistic effect.

In a second aspect, the invention also provides the aqueous polyurea composite modified single-component acrylic waterproof coating prepared by the preparation method in any one of the above schemes.

(III) advantageous effects

The invention has the beneficial effects that: compared with the prior art, the aqueous polyurea composite modified single-component acrylic acid waterproof coating disclosed by the invention has the advantages that by adopting a method of mixing and synergistic effect of the acrylic acid emulsion, the aqueous polyurea emulsion and the graphene powder, the tensile strength of the obtained waterproof coating still can reach more than 1.0MPa and the elongation at break of more than 300% on the premise of 65% of higher solid content, and the waterproof coating still has extremely low water absorption rate, so that the waterproof life of a building is greatly prolonged; the viscosity is low, so that the coating has excellent construction performance;

the invention utilizes the characteristics of excellent extensibility of the acrylic emulsion and low water absorption of the aqueous polyurea emulsion and the smearing shielding effect of the graphene powder lamellar structure to weaken the penetrating power of water molecules, thereby further reducing the water absorption.

The preparation method is simple, so that the obtained waterproof coating is low in cost and low in price, and is favorable for market popularization and application.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present invention by way of specific embodiments thereof.

According to the preparation method of the aqueous polyurea composite modified single-component acrylic waterproof coating provided by the embodiment of the invention, the acrylic emulsion is used for modifying the aqueous polyurea emulsion, and the graphene and other ingredients are combined to play a synergistic effect, so that the mechanical property of the waterproof coating is greatly improved, and the water absorption of the waterproof coating is reduced.

In order to better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below. While the following shows exemplary embodiments of the invention, it should be understood that the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The following examples and comparative examples were each sourced from the following raw materials:

acrylic emulsion: (ii) the chemistry of the dow;

aqueous polyurea emulsion: wanhua chemistry;

defoaming agent: basf;

dispersing agent: (ii) the chemistry of the dow;

mildew preventive: thor;

inorganic filler: xufeng powder materials Co., Ltd;

rutile type titanium dioxide: a group of Tetrapython pythons;

graphene: kernel graphene.

Example 1

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps:

s1, ultrasonically dispersing the graphene powder with the layer number of 1 and the particle size of 12 microns in deionized water for 45min to obtain graphene aqueous dispersion liquid;

s2, sequentially adding a dispersing agent, an organic silicon defoaming agent and a mildew preventive into the graphene aqueous dispersion liquid, and continuously stirring rutile titanium dioxide, 800-mesh barium sulfate and 800-mesh heavy calcium carbonate for 35min at a stirring speed of 1000 r/min;

s3, sequentially adding pure acrylic acid waterproof emulsion with the glass transition temperature of-20 ℃ and aqueous polyurea emulsion with the lowest film forming temperature of 0 ℃, reducing the stirring speed to 600r/min, continuously stirring for 30min, and standing to obtain the aqueous polyurea composite modified single-component acrylic acid waterproof coating;

in the embodiment, by weight, 1 part of graphene, 6 parts of deionized water, 0.5 part of a dispersing agent, 1 part of an organic silicon defoaming agent, 10 parts of rutile titanium dioxide, 800-mesh barium sulfate, 30 parts of 800-mesh heavy calcium carbonate, 0.1 part of a mildew inhibitor, 45 parts of an acrylic emulsion and 10 parts of a water-based polyurea emulsion.

Example 2

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps:

s1, ultrasonically dispersing 3 layers of graphene powder with the particle size of 7 microns in deionized water for 60min to obtain graphene aqueous dispersion liquid;

s2, sequentially adding a dispersing agent, a mineral oil defoaming agent and a mildew preventive into the graphene aqueous dispersion, and continuously stirring the rutile type titanium dioxide, 800-mesh barium sulfate, 800-mesh mica powder and 1000-mesh talcum powder for 25min at the stirring speed of 800 r/min;

s3, sequentially adding pure acrylic acid waterproof emulsion with the glass transition temperature of-20 ℃ and aqueous polyurea emulsion with the lowest film forming temperature of 0 ℃, reducing the stirring speed to 500r/min, continuously stirring for 25min, and standing to obtain the aqueous polyurea composite modified single-component acrylic acid waterproof coating;

in the embodiment, by weight, 0.5 part of graphene, 4 parts of deionized water, 0.2 part of a dispersing agent, 0.5 part of a mineral oil defoaming agent, 5 parts of rutile titanium dioxide, 10 parts of 800-mesh barium sulfate, 10 parts of 800-mesh mica powder, 15 parts of 1000-mesh talcum powder, 0.05 part of a mildew inhibitor, 48 parts of acrylic emulsion and 5 parts of water-based polyurea emulsion.

Example 3

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps:

s1, ultrasonically dispersing 2 layers of graphene powder with the particle size of 10 microns in deionized water for 70min to obtain graphene aqueous dispersion liquid;

s2, sequentially adding a dispersing agent, a mineral oil defoaming agent and an organic silicon defoaming agent into the graphene aqueous dispersion liquid, and continuously stirring the rutile type titanium dioxide, 800-mesh barium sulfate, 800-mesh heavy calcium carbonate, 800-mesh mica powder and 1000-mesh talcum powder for 30min at the stirring speed of 900 r/min;

s3, sequentially adding pure acrylic acid waterproof emulsion with the glass transition temperature of-20 ℃ and aqueous polyurea emulsion with the lowest film forming temperature of 0 ℃, reducing the stirring speed to 400r/min, continuously stirring for 35min, and standing to obtain the aqueous polyurea composite modified single-component acrylic acid waterproof coating;

in the embodiment, by weight, 1 part of graphene, 2 parts of deionized water, 0.4 part of a dispersant, 1 part of a mineral oil defoaming agent, 7 parts of rutile titanium dioxide, 18 parts of 800-mesh barium sulfate, 12 parts of 800-mesh heavy calcium carbonate, 3 parts of 800-mesh mica powder, 50 parts of an acrylic emulsion and 10 parts of a water-based polyurea emulsion.

Comparative example 1

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps: the other steps are the same as the example 3, and the difference is that: the aqueous polyurea emulsion was replaced with an acrylic emulsion, and no graphene was added in step S1.

Comparative example 2

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps: the other steps are the same as the example 3, and the difference is that: the acrylic emulsion is replaced by the aqueous polyurea emulsion, and graphene is not added in step S1.

Comparative example 3

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps: the other steps are the same as the example 3, and the difference is that: the aqueous polyurea emulsion was replaced with an acrylic emulsion.

Comparative example 4

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps: the other steps are the same as the example 3, and the difference is that: the acrylic emulsion is replaced by an aqueous polyurea emulsion.

Comparative example 5

The preparation method of the water-based polyurea composite modified single-component acrylic acid waterproof coating comprises the following steps: the other steps are the same as the example 3, and the difference is that: in step S1, no graphene is added.

The aqueous polyurea composite modified single-component acrylic waterproof coatings obtained in the above examples 1-3 and comparative examples 1-4 were subjected to performance tests, and the results shown in Table 1 were obtained according to JC/T864-2008 "Polymer emulsion building waterproof coating":

TABLE 1 Performance testing of aqueous polyurea composite modified monocomponent acrylic waterproof coatings

As can be seen from the data in Table 1, examples 1-3 have a stronger combination of properties, including tensile strength, elongation at break, and water resistance, and are significantly stronger than comparative examples 1-4. From a comparison of the data of comparative examples 1 to 4 and example 3, it can be seen that: the acrylic emulsion, the water-based polyurea emulsion and the graphene have a synergistic effect on the performances of the waterproof coating in the aspects of tensile strength and waterproofness.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.