Polymer cement-based waterproof coating containing waste stone powder and application thereof

Abstract

The application discloses a polymer cement-based waterproof coating containing waste stone powder and application thereof, and belongs to the technical field of road materials. In the product, the inorganic filler can be completely waste stone powder. The waste stone powder is pre-activated, and specific content of alginic acid and hydrophilic fumed silicon dioxide is introduced into a compounded liquid material. The obtained product completely meets the application standard of JS waterproof coating, and has good mechanical strength and protection performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of road materials, in particular to a polymer cement-based waterproof coating containing waste stone powder and application thereof. BACKGROUND

[0002] JS waterproof coating is a kind of building coating formed by compounding emulsion, cement and inorganic fillers. In use, the emulsion in the liquid material wraps the cement and inorganic fillers. With the evaporation of water in the liquid material, the emulsion particles dehydrate, deform, accumulate and adhere to form a polymer film. On the other hand, the cement and water in the liquid material undergo hydration reaction and interweave with the polymer film to solidify, finally forming a highly dense coating film structure, which has the advantages of both cement and polymer materials.

[0003] In the powder formulation of JS waterproof coating, in addition to cement, the existing inorganic fillers are mostly quartz sand, calcium carbonate and talc powder, which have good mechanical properties and good solidification effect on the coating. However, with the rise of environmental protection and recycling trend of building materials, people try to use industrial waste stone powder (such as waste calcite powder, granite powder and fly ash) as filler to prepare JS waterproof coating. However, due to the low strength, high impurity content, small particle size and uneven dispersion of such stone powder, the performance of the prepared product is difficult to meet the use standard. At present, only a small amount of waste stone powder can be doped or replaced with traditional fillers in the traditional JS waterproof coating powder formulation, and the utilization rate of waste stone powder is low. SUMMARY

[0004] Based on the defects of the prior art, the purpose of the present application is to provide a polymer cement-based waterproof coating containing waste stone powder. The inorganic filler in the product can be completely waste stone powder. By pre-activating the waste stone powder and introducing a specific amount of alginic acid and hydrophilic fumed silica into the compounded liquid material, the obtained product fully meets the application standard of JS waterproof coating and has good mechanical strength and protective performance.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A polymer cement-based waterproof coating containing waste stone powder comprises the following components by weight:

[0007] 40-60 parts of acrylic emulsion, 20-30 parts of ethylene-vinyl acetate emulsion, 10-20 parts of alginic acid, 40-60 parts of cement, 40-60 parts of modified waste stone powder and 20-40 parts of hydrophilic fumed silica.

[0008] The modified waste stone powder is methyl methacrylic acid grafted waste stone powder.

[0009] In the prior art, the application rate of waste stone powder in JS waterproof coating is low. In addition to the low strength of waste stone powder compared with sand filler, another main reason is that it cannot achieve good dispersibility and stability in the preparation of products, and it is easy to cause agglomeration, water absorption and falling off after being prepared into cement or coating products. Therefore, the inventors increase the proportion of filler based on the traditional JS waterproof coating formula, and at the same time, the waste stone powder is subjected to methacrylic acid grafting treatment. Since methacrylic acid has hydrophobicity, it can effectively isolate external water vapor or hydroxyl-containing substances prone to reaction, thereby avoiding the problem of high water absorption of waste stone powder during production and use. On the other hand, in order to solve the problem of dispersibility of small size waste stone powder during product mixing and preparation, the inventors add alginic acid with adhesion and agglomeration inhibition effect and hydrophilic fumed silica in the product formula. When the powder and liquid are mixed, the alginic acid can quickly wrap each powder and act as a buffer layer for the waste powder. Under the action of the methacrylic acid grafted on the surface of the waste stone powder, the waste stone powder can remain relatively dispersed, and the fumed silica can selectively absorb the surrounding water vapor during the dehydration and adhesion of the polymer, the cement hydration reaction and after the product is prepared, thereby avoiding the concentration of water vapor being absorbed by the waste stone powder, so as to ensure that the product has sufficient water resistance and impermeability. Under the joint action of the two, the waste stone powder is effectively and uniformly dispersed in the coating product, the product has small porosity and high density, so that the mechanical strength and protective performance can reach the level of traditional inorganic filler system JS waterproof coating, meeting the requirements of GB / T 23445-2009 standard.

[0010] Preferably, the hydrophilic fumed silica has a mesh size of 400-800 mesh.

[0011] In addition to acting as a synergistic filler in the product, as described above, the main role of the hydrophilic fumed silica is to inhibit the water absorption of the waste stone powder. However, if the size of this component is too small, its water vapor attraction and aggregation effect will be weakened, and the water vapor attached to the hydrophilic fumed silica will still be attracted by the waste stone powder, resulting in poor waterproof performance of the product and reduced bonding strength. On the other hand, if the size of this component is too large, it may agglomerate to some extent during product preparation due to its water absorption, which will also affect the performance of the product. Therefore, the hydrophilic fumed silica with the above mesh size range has the best effect.

[0012] Preferably, the solid content of the acrylic emulsion is 40-60%.

[0013] Preferably, the solid content of the ethylene-vinyl acetate emulsion is 50-60%.

[0014] Preferably, the cement is Portland cement.

[0015] More preferably, the Portland cement is at least one of Type I Portland cement, Type II Portland cement.

[0016] More preferably, the compressive strength grade of the Portland cement is any one of 42.5, 52.5, 62.5.

[0017] Preferably, the preparation method of the modified waste stone powder comprises the following steps:

[0018] (1) dispersing the waste stone powder in water, then adding a silane coupling agent for activation treatment, drying to obtain the activated waste stone powder;

[0019] (2) dispersing the activated waste stone powder in water, then adding methyl acrylic acid, mixing and heating to 70-90℃ for 8-10h of reaction, drying to obtain the modified waste stone powder.

[0020] It should be noted that in addition to the above-mentioned activation-grafting process for preparing the modified waste stone powder, other systems can also be used for preparation, for example, when the silica content in the waste stone powder is high, inorganic acid soaking or direct heating can be used for activation of the waste stone powder, and non-aqueous phase reaction environment can also be used for modification, as long as the product meets the requirements of the present application.

[0021] More preferably, the silane coupling agent is KH550.

[0022] More preferably, the mass ratio of the waste stone powder to the silane coupling agent is 1:(0.1-1).

[0023] More preferably, the mass ratio of the waste stone powder to the methyl acrylic acid is 1:(0.1-0.2).

[0024] More preferably, the mass content of the methyl acrylic acid in the modified waste stone powder is 8-15wt%.

[0025] As the concentration of methyl acrylic acid introduced during the grafting reaction increases, the grafting rate of methyl acrylic acid in the final modified waste stone powder will also increase, but too much methyl acrylic acid will cause the hydrophobicity of the waste stone powder to be too high. Since JS waterproof coating needs to be prepared and coated in an aqueous solvent, if the hydrophobicity of the waste stone powder is too high, combined with the small size of the waste stone powder, the waste stone powder may partially precipitate and agglomerate, therefore, the modified waste stone powder with the above-mentioned preferred grafting amount of methyl acrylic acid has the best use effect.

[0026] Preferably, the waste stone powder comprises at least one of waste calcite powder, waste granite powder, waste fly ash, and waste basalt stone powder.

[0027] More preferably, the waste stone powder has a mesh size of 200-800 mesh.

[0028] In the JS waterproof coating product, the particle size of the inorganic filler has certain influence on the rigidity and toughness (specifically manifested in tensile strength and elongation at break, etc.) of the product. The smaller the particle size, the lower the tensile strength of the product, but the higher the elongation at break. With the increase of the particle size, the two performances change in opposite trends. The degree of change is different based on the type of inorganic filler. For the waste stone powder described in the present application, because the particle hardness is higher than that of general quartz sand and talc powder, but the size is relatively small, a good rigidity and toughness balance and a high level of comprehensive mechanical properties can be achieved under the above preferred mesh size.

[0029] Preferably, the mass ratio of alginic acid to hydrophilic fumed silica is 1:(2-2.5).

[0030] As described above, the alginic acid and the hydrophilic fumed silica in the present application have a great influence on the stability and dispersibility of the waste stone powder. When the ratio of the two is within the above preferred range, the mechanical strength, stability and protection performance of the product are optimal.

[0031] Preferably, the components of the waste stone powder-containing polymer cement-based waterproof coating further include 10-20 parts of a processing aid.

[0032] More preferably, the processing aid includes at least one of a film-forming agent, a preservative and a defoaming agent.

[0033] Preferably, the components of the waste stone powder-containing polymer cement-based waterproof coating further include water.

[0034] Another object of the present application is to provide the application of the waste stone powder-containing polymer cement-based waterproof coating in building protection.

[0035] The waste stone powder-containing polymer cement-based waterproof coating described in the present application uses pure waste stone powder as the inorganic filler to prepare the product. Under the specific modification and component collocation, the product not only has lower production cost, but also has the same grade of mechanical properties and stability as the existing JS waterproof coating, and is even better in protection effect, with excellent impermeability and waterproofness.

[0036] The present application has the advantage that the present application provides a waste stone powder-containing polymer cement-based waterproof coating. The inorganic filler in the product can be completely waste stone powder. Through pre-activation treatment of the waste stone powder, and introduction of specific content of alginic acid and hydrophilic fumed silica in the compounded liquid, the obtained product completely meets the application standard of JS waterproof coating, and has good mechanical strength and protection performance. DETAILED DESCRIPTION

[0037] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific examples and comparative examples, which aims to understand the content of the present application in detail, rather than limiting the present application. All other examples obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present application. The experimental reagents and instruments involved in the implementation of the present application are all common reagents and instruments unless otherwise specified.

[0038] Example 1

[0039] An embodiment of the polymer cement-based waterproof coating containing waste stone powder and the application thereof according to the present application is shown in Table 1.

[0040] In each component, the waste stone powder 1 is a mixture of waste granite powder and fly ash produced by a factory in Huadu, Guangzhou, with a mass ratio of about 7:3, and the mesh size after grinding is 325-400 mesh.

[0041] The waste stone powder 2 is a mixture of waste calcite powder and waste basalt powder produced by a factory in Nansha, Guangzhou, with a mass ratio of about 5:5, and the mesh size after grinding is 325-400 mesh.

[0042] The talc powder is a 325 mesh product produced by Shengfei Mineral Products.

[0043] The quartz sand is a 200 mesh product produced by Donghai Xiangzhi.

[0044] The acrylic emulsion is ACRONAL 7237 product produced by BASF, with a solid content of 50%.

[0045] The ethylene-vinyl acetate emulsion is VAE707 product produced by Dongfang Oil, with a solid content of 54%.

[0046] The alginic acid is a commercially available product with a purity of more than 99%.

[0047] The carboxymethyl cellulose is a commercially available product with a purity of more than 99%.

[0048] The cement is a commercially available Portland cement with a compressive strength grade of 42.5.

[0049] The modified waste stone powder 1 is a self-made product, and the preparation method comprises the following steps:

[0050] (1) The waste stone powder 1 is dispersed in water according to a mass ratio of 1:10, and then a silane coupling agent KH550 is added and stirred to activate for 60 min, and then the water phase is filtered and dried to obtain the activated waste stone powder; the mass ratio of the waste stone powder to KH550 is 1:0.5;

[0051] (2) The activated waste stone powder is dispersed in water at a ratio of 1:20, then methyl methacrylate is added and mixed and heated to 80°C for 10h, the water phase is filtered and dried to obtain the modified waste stone powder with a grafting rate of about 10%; the mass ratio of the waste stone powder to methyl methacrylate is 1:0.15.

[0052] The modified waste stone powder 2 is a self-made product, and the preparation method is the same as that of the modified waste stone powder 1, except that the waste stone powder 1 is replaced by the waste stone powder 2.

[0053] The modified waste stone powder 3 is a self-made product, and the preparation method is the same as that of the modified waste stone powder 1, except that the mass ratio of the waste stone powder to methyl methacrylate is 1:0.1, and the grafting rate is about 8%.

[0054] The modified waste stone powder 4 is a self-made product, and the preparation method is the same as that of the modified waste stone powder 1, except that the mass ratio of the waste stone powder to methyl methacrylate is 1:0.2, and the grafting rate is about 14%.

[0055] The modified waste stone powder 5 is a self-made product, and the preparation method is the same as that of the modified waste stone powder 1, except that the mass ratio of the waste stone powder to methyl methacrylate is 1:0.05, and the grafting rate is about 6%.

[0056] The modified waste stone powder 6 is a self-made product, and the preparation method is the same as that of the modified waste stone powder 1, except that the mass ratio of the waste stone powder to methyl methacrylate is 1:0.25, and the grafting rate is about 18%.

[0057] The modified waste stone powder 7 is a self-made product, and the preparation method comprises the following steps:

[0058] The waste stone powder 1 is dispersed in water at a ratio of 1:10, then the silane coupling agent KH550 is added and stirred and mixed for activation treatment for 60min, then the water phase is filtered and dried to obtain the modified waste stone powder 6; the mass ratio of the waste stone powder to KH550 is 1:0.5.

[0059] The hydrophilic fumed silica 1 is a 400-mesh precipitated hydrophilic white carbon black produced by Kinmin.

[0060] The hydrophilic fumed silica 2 is a 600-mesh precipitated hydrophilic white carbon black produced by Mozhu Building Materials.

[0061] The hydrophilic fumed silica 3 is a 325-mesh precipitated hydrophilic white carbon black produced by Kinmin.

[0062] The hydrophilic fumed silica 4 is a 1000-mesh N20 hydrophilic white carbon black produced by Wacker, Germany.

[0063] The hydrophobic fumed silica 1 is 400 mesh precipitated hydrophobic white carbon black produced by Quickmill.

[0064] The hydrophobic fumed silica 2 is 1000 mesh H20 hydrophobic white carbon black produced by Wacker, Germany.

[0065] The defoaming agent is a commercially available silicone defoaming agent.

[0066] The film forming agent is a commercially available ethylene glycol.

[0067] Table 1

[0068]

[0069] Table 2

[0070]

[0071] Example 1

[0072] In order to verify the use effect of the polymer cement-based waterproof coating according to the present application, the components of each example and comparative example are divided into liquid materials (acrylic emulsion, ethylene-vinyl acetate emulsion, alginic acid, defoaming agent, film forming agent, water) and powder materials (cement, modified / non-modified waste stone powder, hydrophilic / hydrophobic fumed silica, talc powder, quartz sand), and after good batching, the powder materials are poured into the liquid materials and directly mixed uniformly, and then construction and testing are carried out according to GB / T23445-2009, the construction temperature is 26℃, and the material mixing time is ≥30 min to ensure uniform stirring. The results are shown in Table 1.

[0073] Table 1

[0074]

[0075]

[0076] As can be seen from Table 1, the polymer-based waterproof coating containing waste stone powder according to the present application has good application performance. Compared with the product prepared by using conventional inorganic fillers according to Comparative Example 1, the inorganic fillers in the product of each example can be completely waste stone powder, and the prepared product reaches the same level in terms of mechanical properties, protective properties or bonding properties, indicating that the product can completely replace the existing similar products on the market, and the product completely meets the requirements of GB / T 23445-2009 standard. However, the product system prepared by using waste stone powder as inorganic fillers needs to have specific limitations. As shown in Comparative Example 2, if waste stone powder is directly used to prepare the product, the obtained product does not meet the requirements in terms of mechanical strength, protection and bonding due to the mechanical properties, uneven dispersion and water permeability of the waste stone powder. The product shown in Comparative Example 3 is modified by silane on the basis of waste stone powder, which effectively improves the dispersion of components during preparation, and the mechanical properties and bonding properties meet the requirements, but the product has poor impermeability and waterproof effect, indicating that only improving the dispersion cannot inhibit the water permeability in the product, and further grafting modification needs to be performed on the waste stone powder. As can be seen from the product properties of Example 1 and Examples 4-8, the grafting of methacrylic acid not only makes the waste stone powder have hydrophobicity, but also improves the dispersion uniformity of the waste stone powder in the component system under the joint action of alginic acid. However, the balance between the hydrophobicity and the alginic acid is tilted, which may lead to the agglomeration of part of the waste stone powder, so the grafting rate of 6-18%, preferably 8-15%, is the best. In Comparative Examples 4 and 5, the fumed silica used in the product is not hydrophilic but hydrophobic. In theory, the waterproof and impermeable effect of the product prepared by using hydrophobic fumed silica should be better than that of the product prepared by using hydrophilic fumed silica. However, in practice, the two products have poor impermeability and water permeability, indicating that the waterproofness of fumed silica itself is not the determining factor of the waterproofness of the final product, and even the effect of smaller hydrophobic fumed silica is worse. Since the role of fumed silica is mainly to make the water separate from the waste stone powder during the preparation reaction to uniformly disperse the waste stone powder and finally improve the compactness of the product, only hydrophilic fumed silica can achieve this effect. Further, as can be seen from the comparison of the products of Example 1 and Examples 9-11, since fumed silica also belongs to fillers, the size change will affect the mechanical properties and bonding strength of the product to some extent. However, too large or too small size will still make it unable to achieve the best water adsorption effect, thereby weakening the bonding properties and impermeability to some extent. In Comparative Example 6, the alginic acid in the product components is replaced by carboxymethyl cellulose, which also has certain hydrophilicity and viscosity. The prepared product meets the requirements, but the performance of each aspect is lower than that of Example 1 with a single variable, indicating that only alginic acid can be used as a complex component to achieve the expected effect of the waste stone powder system JS waterproof coating.According to the embodiment 1, the embodiment 12-14 and the comparative examples 7-8, it can be seen that when the proportion of the introduced hydrophilic fumed silica is too small, the mechanical properties of the product are poor, and the waterproof and impermeable effects are poor. With the increase of the proportion of the component, the mechanical properties of the product are gradually improved, and the waterproof and impermeable effects are also improved, but after reaching a certain limit, the waterproof and impermeable effects of the product begin to decline due to the dispersion problem of the component, and the hydrophilic effect of the component is significantly multiplied with too much amount, the impermeability of the comparative example 8 is low and not waterproof. The addition amount of the alginic acid in the product of the comparative example 9 is too much, as described above, the alginic acid itself has hydrophilic property, and when too much is introduced, the hydrophilic effect is multiplied, which leads to the product even having certain water absorption, so the waterproof and impermeable properties of the product are sharply decreased, which shows that the introduction of the alginic acid should not be too much.

[0077] In addition, since the waste stone powder used in the present application has high hardness, especially the waste granite powder and the waste basalt stone powder, both of which have higher "pozzolanic effect" when mixed with cement, the hardness and wear resistance of the prepared product are better than those of the product described in the comparative example 1 (the hardness of the product of each embodiment can reach 5-6H, and the hardness of the product of the embodiment 4 reaches 6H, and the hardness of the product of the comparative example 1 is only 4H), so in fact, the practicality of the JS waterproof coating described in the present application is stronger than that of the commercially available product.

[0078] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A polymer-cement-based waterproof coating containing waste stone powder, characterized in that, The components include the following parts by weight: Acrylic emulsion 40-60 parts, ethylene-vinyl acetate emulsion 20-30 parts, alginic acid 10-20 parts, cement 40-60 parts, modified waste stone powder 40-60 parts, hydrophilic fumed silica 20-40 parts. The modified waste stone powder is methacrylic acid-grafted waste stone powder.

2. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The hydrophilic fumed silica has a mesh size of 400-800 mesh.

3. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The method for preparing the modified waste stone powder includes the following steps: (1) Disperse waste stone powder in water, then add silane coupling agent for activation treatment, and dry to obtain activated waste stone powder; (2) Disperse the activated waste stone powder in water, then add methacrylic acid, mix and heat to 70~90℃ for 8~10h, dry to obtain the modified waste stone powder.

4. The polymer cement-based waterproof coating containing waste stone powder as described in claim 3, characterized in that, In the method for preparing the modified waste stone powder, the mass ratio of the waste stone powder to the silane coupling agent is 1:(0.1~1), and / or the mass ratio of the waste stone powder to methacrylic acid is 1:(0.1~0.2).

5. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The modified waste stone powder contains 8-15 wt% methacrylic acid.

6. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The waste stone powder includes at least one of waste calcite powder, waste granite powder, waste fly ash, and waste basalt powder.

7. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The mass ratio of alginic acid to hydrophilic fumed silica is 1:(2~2.5).

8. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The polymer cement-based waterproof coating containing waste stone powder also includes 10-20 parts of processing aids; the processing aids include at least one of film-forming agents, preservatives, and defoamers.

9. The polymer cement-based waterproof coating containing waste stone powder as described in claim 1, characterized in that, The acrylic emulsion has a solid content of 40-60%, and / or the ethylene-vinyl acetate emulsion has a solid content of 50-60%, and / or the cement is silicate cement.

10. The application of the polymer cementitious waterproof coating containing waste stone powder as described in any one of claims 1 to 9 in building protection.

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