A single-component self-healing waterproof coating and its preparation method

Abstract

This invention relates to the field of coating technology, and proposes a single-component self-healing waterproof coating and its preparation method. The single-component self-healing waterproof coating comprises the following components in parts by weight: 40-50 parts of water-based acrylic emulsion, 0.1-0.4 parts of superdispersant, 0.2-0.5 parts of water-based defoamer, 0.2-0.4 parts of bactericide, 3-5 parts of water-swellable material, 10-15 parts of cement, 10-20 parts of heavy calcium carbonate, 15-20 parts of precipitated barium sulfate, 0.3-0.5 parts of thickener, and 5-10 parts of water; the superdispersant is one or more of Solsperse 20000, Solsperse 27000, and Solsperse 47000. Through the above technical solution, the problem of poor impermeability of existing single-component self-healing waterproof coatings is solved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a single-component self-healing waterproof coating and its preparation method. Background Technology

[0002] The waterproof coatings used in building waterproofing construction are mainly rolls and coatings. Waterproof coatings are divided into two-component and single-component coatings. Among them, the two-component JS~II type waterproof coating (the model specified in GB 50108~2008) used in underground engineering has an elongation requirement of only 80%. With the settlement of buildings and changes in the surrounding environment, buildings are very prone to cracking, which leads to building leakage. Such cracks are difficult to repair by the waterproof coating.

[0003] In recent years, my country's single-component waterproof coatings have developed rapidly. They can not only meet the needs of various waterproofing projects, but also be applied in the field of civil waterproofing. However, when existing single-component waterproof coatings are used in underground engineering, they contain a large amount of volatile small-molecule aromatic oils, which can easily cause environmental and water pollution. In addition, they have poor impermeability and are prone to cracking that is difficult to repair. Therefore, in order to improve the impermeability of single-component waterproof coatings, it is extremely important to develop a single-component self-healing waterproof coating with good impermeability for its application in building waterproofing. Summary of the Invention

[0004] This invention proposes a single-component self-healing waterproof coating and its preparation method, which solves the problem of poor impermeability of single-component self-healing waterproof coatings in related technologies.

[0005] The technical solution of the present invention is as follows:

[0006] This invention proposes a single-component self-healing waterproof coating, comprising the following components in parts by weight: 40-50 parts of water-based acrylic emulsion, 0.1-0.4 parts of superdispersant, 0.2-0.5 parts of water-based defoamer, 0.2-0.4 parts of bactericide, 3-5 parts of water-swellable material, 10-15 parts of cement, 10-20 parts of heavy calcium carbonate, 15-20 parts of precipitated barium sulfate, 0.2-0.5 parts of thickener, and 5-10 parts of water;

[0007] The superdispersant is one or more of Solsperse 20000, Solsperse 27000 and Solsperse 47000.

[0008] As a further technical solution, the aqueous acrylic emulsion is a pure acrylic emulsion.

[0009] As a further technical solution, the water-based defoamer includes one or more of defoamer BYK011, defoamer BYK022, and defoamer tego825.

[0010] As a further technical solution, the bactericide is MBS bactericide.

[0011] As a further technical solution, the water-swellable material includes one or more of sodium methylsilanolate, sodium silicate, lithium magnesium silicate, sodium fluorosilicate, and organophosphonic acid.

[0012] As a further technical solution, the cement is composed of 70% to 80% silicate clinker, 15% to 20% natural gypsum, and 5% to 10% aggregate by mass percentage; the aggregate is composed of 70% to 80% granulated blast furnace slag, 15% to 20% pozzolanic mixture, and 5% to 10% fly ash by mass percentage.

[0013] As a further technical solution, the heavy calcium carbonate is one or more of dolomite calcium carbonate, calcite calcium carbonate, limestone calcium carbonate, and marble calcium carbonate.

[0014] As a further technical solution, the precipitated barium sulfate is one of chloride-process barium sulfate and sulfuric acid-process barium sulfate; the thickener is one or more of hydrophobic polyurethane, associative alkali-swelling thickener, cellulose-based thickener and bentonite-based thickener.

[0015] This invention also proposes a method for preparing a single-component self-healing waterproof coating, comprising the following steps:

[0016] S1. Disperse and mix water, superdispersant, and water-swellable agent to obtain mixture A;

[0017] S2. Disperse and mix the water-based acrylic emulsion and the water-based defoamer to obtain mixture B;

[0018] S3. Add a bactericide to the mixture B and stir to obtain mixture C;

[0019] S4. Add cement, heavy calcium carbonate, and precipitated barium sulfate to the mixture C, stir, and degas to obtain mixture D;

[0020] S5. Add a thickener to the mixture D, mix, and obtain mixture E;

[0021] S6. Add the mixture E to the mixture A and stir to obtain a single-component self-healing waterproof coating.

[0022] As a further technical solution, in step S1, the speed of dispersion mixing is 300~400 rpm and the time is 20~30 min;

[0023] In step S2, the dispersion and mixing speed is 400~500 rpm and the time is 10~15 min;

[0024] In step S3, the stirring time is 10-15 minutes;

[0025] In step S4, the stirring speed is 600~800 rpm and the time is 25~30 min; the degassing speed is 200~250 rpm and the time is 40~50 min.

[0026] In step S5, the viscosity of the mixture E is 3000 mPa·s to 3500 mPa·s; in step S6, the stirring speed is 500 to 600 rpm and the stirring time is 20 to 30 min.

[0027] The working principle and beneficial effects of this invention are as follows:

[0028] 1. In this invention, water-based acrylic emulsion is used as the base material, and a super dispersant is added to improve the dispersibility between the water-based acrylic emulsion and the water-swellable substance. Solsperse 20000, Solsperse 27000, and Solsperse 47000 are used as super dispersants to improve the dispersibility between organic and inorganic substances in the coating, thereby significantly improving the impermeability of the waterproof coating.

[0029] 2. In this invention, a stepwise mixing process is adopted, in which a super dispersant is first used to encapsulate and pre-disperse the water-swellable material, then the water-based acrylic emulsion is used to encapsulate the powder, and then the water-based acrylic emulsion encapsulating the powder is added to the super dispersant that has encapsulated and pre-dispersed the water-swellable material. This process prevents agglomeration between particles, improves the dispersion effect of cement and other additives in the water-based acrylic emulsion, and further improves the impermeability of the waterproof coating. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] The specifications of the components used in the following examples and comparative examples are shown in Table 1.

[0032]

[0033] Example 1

[0034] The single-component self-healing waterproof coating comprises the following components in parts by weight: 44.5 parts pure acrylic emulsion, 0.3 parts super-dispersant Solsperse 20000, 0.3 parts water-based defoamer BYK011, 0.2 parts MBS bactericide, 3.5 parts sodium methylsiloxane, 11 parts cement with a fineness of 400 mesh, 15 parts dolomite calcium carbonate, 17 parts chlorinated precipitated barium sulfate, 0.2 parts hydrophobic polyurethane, and 8 parts water.

[0035] The cement with a fineness of 400 mesh is composed of 80% silicate clinker, 15% natural gypsum, 3.5% granulated blast furnace slag, 1% pozzolanic admixture and 0.5% fly ash by mass.

[0036] A method for preparing a single-component self-healing waterproof coating includes the following steps:

[0037] The components of a single-component self-healing waterproof coating are directly mixed to obtain a single-component self-healing waterproof coating.

[0038] Example 2

[0039] A single-component self-healing waterproof coating comprises the following components in parts by weight: 40 parts pure acrylic emulsion, 0.1 parts super-dispersant Solsperse 20000, 0.1 parts water-based defoamer BYK022, 0.1 parts defoamer Tego825, 0.4 parts MBS bactericide, 1.5 parts lithium magnesium silicate, 1.5 parts sodium silicate, 10 parts cement with a fineness of 400 mesh, 10 parts calcite calcium carbonate, 10 parts dolomite calcium carbonate, 20 parts barium sulfate precipitated by sulfuric acid process, 0.15 parts associative alkali-swelling thickener, 0.15 parts sodium carboxymethyl cellulose, and 5 parts water.

[0040] The cement with a fineness of 400 mesh is composed of 80% silicate clinker, 15% natural gypsum, 3.5% granulated blast furnace slag, 1% pozzolanic admixture and 0.5% fly ash by mass.

[0041] A method for preparing a single-component self-healing waterproof coating includes the following steps:

[0042] The components of a single-component self-healing waterproof coating are directly mixed to obtain a single-component self-healing waterproof coating.

[0043] Example 3

[0044] A single-component self-healing waterproof coating comprises the following components in parts by weight: 50 parts pure acrylic emulsion, 0.4 parts super-dispersant Solsperse 20000, 0.5 parts water-based defoamer Tego825, 0.3 parts MBS bactericide, 5 parts organophosphonic acid, 15 parts cement with a fineness of 400 mesh, 10 parts limestone calcium carbonate, 15 parts barium sulfate precipitated by sulfuric acid process, 0.5 parts sodium carboxymethyl cellulose, and 10 parts water.

[0045] The cement with a fineness of 400 mesh is composed of 70% silicate clinker, 20% natural gypsum, 8% granulated blast furnace slag, 1.5% pozzolanic admixture and 0.5% fly ash by mass.

[0046] A method for preparing a single-component self-healing waterproof coating includes the following steps:

[0047] The components of a single-component self-healing waterproof coating are directly mixed to obtain a single-component self-healing waterproof coating.

[0048] Example 4

[0049] The only difference between this embodiment and Embodiment 1 is that the superdispersant Solsperse 20000 is replaced with the superdispersant Solsperse 47000.

[0050] Example 5

[0051] The only difference between this embodiment and Embodiment 1 is that the superdispersant Solsperse 20000 is replaced with the superdispersant Solsperse 27000.

[0052] Example 6

[0053] The difference between this embodiment and Embodiment 5 lies only in the use of a stepwise mixing process to prepare a single-component self-healing waterproof coating. The preparation method includes the following steps:

[0054] S1. Mix water, superdispersant, and water-swellable agent, stir at 300 rpm for 30 min to disperse, and obtain mixture A;

[0055] S2. Mix the water-based acrylic emulsion and water-based defoamer, stir at 400 rpm for 15 min to disperse, and obtain mixture B;

[0056] S3. Add bactericide to mixture B and stir for 10 minutes to obtain mixture C;

[0057] S4. Add cement, heavy calcium carbonate, and precipitated barium sulfate to mixture C, stir at 600 rpm for 30 min, and degas at 200 rpm for 50 min to obtain mixture D;

[0058] S5. Add a thickener to mixture D to obtain a mixture with a viscosity of 3000 mPa·s;

[0059] S6. Add mixture D to mixture A and stir at 500 rpm for 30 min to obtain a single-component self-healing waterproof coating.

[0060] Example 7

[0061] The difference between this embodiment and Embodiment 6 lies only in the preparation method of the single-component self-healing waterproof coating, which includes the following steps:

[0062] S1. Mix water, superdispersant, and water-swellable agent, stir at 400 rpm for 20 min to disperse, and obtain mixture A;

[0063] S2. Mix the water-based acrylic emulsion and water-based defoamer, stir at 500 rpm for 10 min to disperse, and obtain mixture B;

[0064] S3. Add bactericide to mixture B and stir for 15 minutes to obtain mixture C;

[0065] S4. Add cement, heavy calcium carbonate, and precipitated barium sulfate to mixture C, stir at 800 rpm for 25 min, and degas at 250 rpm for 40 min to obtain mixture D;

[0066] S5. Add a thickener to mixture D to obtain mixture E with a viscosity of 3500 mPa·s;

[0067] S6. Add mixture D to mixture A and stir at 600 rpm for 20 min to disperse, thus obtaining a single-component self-healing waterproof coating.

[0068] Comparative Example 1

[0069] The only difference between this comparative example and Example 1 is that the superdispersant Solsperse 20000 is replaced with the superdispersant NUOSPERSE FX 600.

[0070] Comparative Example 2

[0071] The only difference between this comparative example and Example 1 is that the superdispersant Solsperse 20000 is replaced with the superdispersant Dispers 760.

[0072] Comparative Example 3

[0073] The only difference between this comparative example and Example 1 is that the superdispersant Solsperse 20000 is replaced with the superdispersant BYK-190.

[0074] Comparative Example 4

[0075] The only difference between this comparative example and Example 1 is that the superdispersant Solsperse 20000 is not added.

[0076] According to GB 18445-2012 "Cement-based Penetrating Crystalline Waterproofing Materials", the impermeability of the single-component self-healing waterproof coatings prepared in Examples 1-7 and Comparative Examples 1-4 was determined. The test results are shown in Table 2 below:

[0077] Table 2. Results of impermeability test

[0078]

[0079] Based on the data from Examples 1-7 and Comparative Examples 1-4, it can be seen that the single-component self-healing waterproof coatings prepared in Examples 1-7 have a higher anti-seepage pressure ratio compared with Comparative Examples 1-4. This indicates that using water-based acrylic emulsion as a base material and adding super-dispersants Solsperse 20000, Solsperse 27000, and Solsperse 47000 can significantly improve the anti-seepage performance of the waterproof coating.

[0080] According to the data from Examples 5-7, the single-component self-healing waterproof coatings prepared in Examples 6-7 have a higher anti-seepage pressure ratio compared to Example 5. This indicates that the stepwise mixing process of first encapsulating and pre-dispersing the water-swellable material with a super dispersant, then encapsulating the powder with an aqueous acrylic emulsion, and finally adding the aqueous acrylic emulsion encapsulating the powder to the super dispersant that has been fully encapsulated and pre-dispersed can further improve the anti-seepage performance of the waterproof coating.

[0081] The self-healing performance of Example 6 was tested according to Chapter 7.14 of JC / T 2428-2017 "Non-curing rubber asphalt waterproof coating". The test result was passed and no water seepage occurred in the test area.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A one-component self-healing, water repellent coating, characterized in that, The components include the following weight parts: 40~50 parts of water-based acrylic emulsion, 0.1~0.4 parts of hyperdispersant, 0.2~0.5 parts of water-based defoaming agent, 0.2~0.4 parts of bactericide, 3~5 parts of water-swelling substance, 10~15 parts of cement, 10~20 parts of heavy calcium carbonate, 15~20 parts of precipitated barium sulfate, 0.2~0.5 parts of thickening agent, and 5~10 parts of water; The hyperdispersant is Solsperse 27000; The water-swelling substance includes one or more of sodium methylsiliconate, sodium silicate, magnesium lithium silicate, sodium fluorosilicate, and organic phosphonic acid; The preparation method of the single-component self-healing waterproof coating comprises the following steps: S1, dispersing and mixing water, hyperdispersant, and water-swelling substance to obtain a mixture A; S2, dispersing and mixing water-based acrylic emulsion and water-based defoaming agent to obtain a mixture B; S3, adding bactericide to the mixture B and stirring to obtain a mixture C; S4, adding cement, heavy calcium carbonate, and precipitated barium sulfate to the mixture C, stirring, and defoaming to obtain a mixture D; S5, adding thickening agent to the mixture D and mixing to obtain a mixture E; S6, adding the mixture E to the mixture A and stirring to obtain a single-component self-healing waterproof coating.

2. A one-component self-healing water-proof paint according to claim 1, characterized in that, The water-based acrylic emulsion is a pure acrylic emulsion.

3. A one-component self-healing water-proof paint according to claim 1, characterized in that, The water-based defoaming agent includes one or more of defoaming agent BYK011, defoaming agent BYK022, and defoaming agent tegO825.

4. A one-component self-healing water-proof paint according to claim 1, characterized in that, The bactericide is MBS bactericide.

5. A single component self-healing water-proof coating according to claim 1, characterized in that, The cement consists of 70%~80% of silicate clinker, 15%~20% of natural gypsum, and 5%~10% of aggregate in terms of mass percentage; the aggregate consists of 70%~80% of granulated blast furnace slag, 15%~20% of pozzolanic mixed material, and 5%~10% of fly ash in terms of mass percentage.

6. A one-component self-healing water-proof paint according to claim 1, characterized in that, The heavy calcium carbonate is one or more of dolomite calcium carbonate, calcite calcium carbonate, limestone calcium carbonate, and marble calcium carbonate.

7. A one-component self-healing water-proof paint according to claim 1, characterized in that, The precipitated barium sulfate is one of chlorination barium sulfate and sulfuric acid barium sulfate; the thickening agent is one or more of hydrophobic polyurethane, associated alkali-swellable thickener, cellulose thickener, and bentonite thickener.

8. A one-component self-healing water-proof paint according to claim 1, characterized in that, In step S1, the dispersing and mixing is performed at a rotation speed of 300~400 rpm for 20~30 min; In step S2, the dispersing and mixing is performed at a rotation speed of 400~500 rpm for 10~15 min; In step S3, the stirring is performed for 10~15 min; In step S4, the stirring is performed at a rotation speed of 600~800 rpm for 25~30 min, and the defoaming is performed at a rotation speed of 200~250 rpm for 40~50 min; In step S5, the viscosity of the mixture E is 3000 mPa·s~3500 mPa·s; in step S6, the stirring is performed at a rotation speed of 500~600 rpm for 20~30 min.

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