CN113943508A

CN113943508A - Emulsion paint for sand-coated sand multicolor coating system and preparation method thereof

Info

Publication number: CN113943508A
Application number: CN202010687827.XA
Authority: CN
Inventors: 余莉莉; 汪满意
Original assignee: Pangbeijie Coating Materials Shanghai Co ltd
Current assignee: Pangbeijie Coating Materials Shanghai Co ltd
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2022-01-18

Abstract

The invention relates to the field of building coatings, in particular to an emulsion paint for a sand-in-sand multicolor system, a sand-in-sand multicolor system containing the emulsion paint and a preparation method of the emulsion paint. The latex paint comprises: 37-55% of acrylic emulsion, a water-proofing agent and a combination of 80-200 mesh heavy calcium carbonate and 300-400 mesh heavy calcium carbonate, wherein the acrylic emulsion comprises a high-density crosslinking monomer which is selected from linear, branched or cyclic C with at least two hydroxyl groups₂‑C₁₀Alkanes, acrylic esters of polyols and alkoxylated polyolsWherein the percentages are based on the total weight of the latex paint.

Description

Emulsion paint for sand-coated sand multicolor coating system and preparation method thereof

Technical Field

The invention relates to the field of building coatings, in particular to a sand-in-sand multicolor coating system and a preparation method thereof, wherein the latex paint is used for the sand-in-sand multicolor coating system.

Background

The building exterior wall colorful coating system comprises a sand-in-sand colorful system and a sand-in-water colorful system, and the difference is that both a disperse phase and a continuous phase of the sand-in-sand colorful system contain sand, and the sand-in-water colorful system only contains sand in the continuous phase.

The building exterior wall sand-coated sand multicolor paint system is generally a four-coating system, namely, the paint system consists of seal primer, sand-coated sand multicolor middle coating, sand-coated sand multicolor and multicolor finish coat. The seal primer mainly plays a role in improving the adhesion of the coating and resisting saltpetering, but has poor weather resistance and covering power and cannot play a role in multi-color middle coating; the sand-coated sand colorful intermediate coat mainly provides a main color effect matched with the sand-coated sand colorful main coat, however, as the color points in the sand-coated sand colorful layer cannot completely cover the intermediate coat and the partial area of the intermediate coat is exposed, the intermediate coat is required to have the capability of covering the putty layer and have certain weather resistance, so that the area of the intermediate coat which is not covered by the color points can be exposed for a long time. In the market, the sand-coated sand colorful intermediate coat generally only has the performance of covering putty, the adhesion to a base material and the saltpetering resistance and salting-out capability are poor, and the problem of system saltpetering is easily caused by directly using the colorful intermediate coat on a putty base surface. Therefore, in addition to the sand-in-sand multi-color main coat and the middle coat, the system still needs a layer of seal primer to seal the alkalinity of the base layer.

For example, CN101693800A relates to water-based marble-like multicolor paints, and discloses the above four-coat system, including primers, middle coats, multicolor paints, and finishes. CN108468414A relates to a stone-like plate, which also discloses a four-coat system comprising a primer, a middle coat, a colorful stone-like paint and a finishing layer. The methods disclosed in the above-mentioned patent applications all require at least four coating processes, are cumbersome, and add to material costs, construction costs, and time costs.

In addition, although the prior art also has a concept of coating integration, it still has many disadvantages and shortcomings.

For example, CN104151969A discloses a primer-topcoat exterior wall latex paint which is used as a single coat and does not relate to the use with a multicolor, finish coat. This application is only applicable to the outer wall system of scribbling flatly, in order to guarantee the stain resistance, the surface of filming that this bottom surface unification outer wall emulsion paint formed is smooth, therefore can't satisfy the anti-sagging nature after the colored point of sand package spraying, colored point once only sprays thickly and has the risk that colored point gliding sagging, cause the colored point of sand package sand to divide 2-3 multi-gun spraying, the interval time that the colored point was mainly scribbled to every way spraying sand package sand often is 8-12 hours (depending on the weather condition), and there are colored some adhesive force scheduling problem, cause the waste of the colorful system construction cost of sand package sand, and prolong the engineering man-hour, be unfavorable for the progress of engineering to promote.

Accordingly, there is a strong need for an improved sand-in-sand multicolor paint system for exterior walls of buildings that overcomes the above-mentioned disadvantages and drawbacks of the prior art.

However, one of the technical difficulties in improving the sand-in-sand multicolor paint system for building exterior walls is to achieve a balance between the salting-out resistance and the covering power.

The coverage rate of the primer is usually low (70% -80%), the coverage rate of the finish paint is generally required to be more than or equal to 93%, and in order to ensure that the requirement on the coverage of a putty system can be realized by one-time coating, the coverage rate target of at least 95% is usually set. Thus, the prior art typically increases the amount of filler (including titanium dioxide) in the topcoat compared to the primer, and correspondingly increases the emulsion content, however, this simple increase in emulsion content is not advisable, subject to the cost and conventional design principles of the formulation.

The primer is divided into a transparent primer and a non-transparent primer (added with powder), and the permeability and the adhesion of the transparent primer are better than those of the non-transparent primer, because the introduction of the powder influences the penetration of the coating on a substrate. Therefore, from this point of view, the introduction of more powder to obtain higher covering power is disadvantageous to the technical problem to be solved by the present invention, because more filler (including titanium dioxide) causes the film to be less dense, thereby deteriorating the anti-saltpetering ability. It is therefore desirable to find a formulation of the emulsion and the filler and to achieve a balance of the anti-saltpetering properties and the hiding power.

Disclosure of Invention

The invention aims to provide the latex paint to overcome the defects of the prior art.

Specifically, the invention aims to provide the emulsion paint which simultaneously meets the performance standard requirements of a conventional primer (alkali-efflorescence-resistant salting-out and the like) and a sand-coated sand multicolor middle coating (high covering, weather resistance and the like), and can realize the purpose of primer-in-one so as to simplify construction. The latex paint has one or more, preferably all, of the following properties: excellent weatherability, saltpetering resistance, adhesion, water permeability, excellent properties in outdoor early saltpetering challenge tests, excellent sag resistance, especially in sand-in-sand multi-color coating systems, and comparable or better performance compared to traditional primer-plus-basecoat systems.

The invention also aims to simplify the traditional four-coating system into a three-coating system by utilizing the emulsion paint, thereby saving the material and construction cost of one coating, effectively improving the construction efficiency, reducing the construction time, meeting the system matching and construction requirements of the sand-in-sand colorful coating and bringing certain contribution to environmental protection.

The inventors have surprisingly found that the above objects can be achieved by formulations and methods as described and claimed hereinafter.

In one aspect, the present invention relates to a latex paint comprising: 37-55% of acrylic emulsion, a water-proofing agent and a combination of 80-200 mesh heavy calcium carbonate and 300-400 mesh heavy calcium carbonate, wherein the acrylic emulsion comprises a high-density crosslinking monomer which is selected from linear, branched or cyclic C with at least two hydroxyl groups ₂-C₁₀Alkanes, acrylates of polyols and acrylates of alkoxylated polyols or combinations thereof, wherein the percentages are based on the total weight of the latex paint.

In another aspect, the present invention relates to a sand-in-sand multicolor coating system comprising, preferably consisting of:

a) the coating formed from the latex paint described above,

b) the coating is formed by sand-in-sand multicolor paint, and both a disperse phase and a continuous phase in the sand-in-sand multicolor paint contain sand; and

c) optionally, an overcoat formed from a finish varnish.

In a further aspect, the present invention relates to the use of the latex paints according to the invention in coating systems for building exterior walls, in particular sand-in-sand multicolor coating systems.

In yet another aspect, the present invention relates to a method of preparing the latex paint of the invention comprising mixing, preferably homogenizing with agitation, the components of the latex paint as described above.

Detailed Description

For the purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

Moreover, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, i.e., having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.

As used in the specification and the appended claims, the articles "a," "an," and "the" include plural referents unless expressly and unequivocally limited to one referent.

Furthermore, in the present description and in the appended claims, the terms "(meth) acrylic acid", "(meth) acrylic acid" or "poly (meth) acrylic acid" or similar expressions are used to refer to monomers or compounds having a group with a (meth) acryloyl group and include acrylic acid, methacrylic acid, acrylamide, methacrylamide, acrylate or methacrylate and the like and their corresponding polymers, preferably acrylic acid, methacrylic acid, acrylate or methacrylate and the like.

As used herein, the transitional term "comprising" (and other comparable terms, such as "contains" and "including") is "open-ended" and is used to refer to compositions, methods, and the respective component(s) thereof that are essential to the invention, but with the possibility that an unspecified substance may be present.

Further, the use of "or" means "and/or" unless specifically stated otherwise. As used herein, the term "polymer" refers to prepolymers, oligomers, and both homopolymers and copolymers, the prefix "poly" refers to two or more. When ranges are given, any endpoints of those ranges and/or values within those ranges can be combined within the scope of the invention.

In certain embodiments of the present invention, the latex paints according to the present invention comprise a defoamer. The production quality and the production process are affected due to the generation of a large amount of foams in the production and application processes of the coating. Defoamers are additives commonly used in the coating art to eliminate foam. Defoamers include, by chemical structure and composition, but are not limited to, mineral oil, alcohols, fatty acids and fatty acid esters, amides, phosphates, silicones, polyethers, and polyether-modified silicone defoamers. In a preferred embodiment of the invention, the antifoam is selected from mineral oils and can be supplemented with silica. In an exemplary embodiment of the invention, DISPELAIR CF 107, commercially available from BLACKBURN, and DAPRO DF 7079 CN, commercially available from hammied, may be selected to be formulated as antifoaming agents. In certain embodiments of the present invention, the amount of defoamer in the latex paint is from 0.1% to 0.9%, preferably from 0.2% to 0.7%, more preferably from 0.3% to 0.6%, based on the total weight of the latex paint. In a preferred embodiment of the invention, the defoamer comprises a water-soluble polymer in a ratio of 0.5 to 5:1, preferably 1 to 3: 1. more preferably 1.5 to 2.5:1 of the combination of DISPELAIR CF 107 from BLACKBURN and DAPRO DF 7079 CN from the hamames modesty.

In certain embodiments of the present invention, the latex paints according to the present invention comprise a thickener such as a cellulosic thickener. Cellulosic thickeners act as thickening agents by hydrating swollen long chains, and the system exhibits a pronounced pseudoplastic flow set. The cellulosic thickeners include, but are not limited to, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, and the like, and combinations thereof. In a preferred embodiment of the invention, hydroxyethyl cellulose thickeners are used in latex paints, which have thickening, delamination resistance, and sag resistance properties. In a preferred embodiment of the invention, the cellulosic thickener is selected from nonionic water soluble hydroxyethylcellulose. For example, 250HBR, commercially available from Ashland, can be used as a cellulose thickener in latex paints. In certain embodiments of the present invention, the latex paint contains from 0.05% to 0.5%, preferably from 0.08% to 0.4%, and more preferably from 0.1% to 0.25% of a cellulosic thickener, based on the total weight of the latex paint.

In certain embodiments of the present invention, latex paints according to the present invention may also contain polyurethane associative thickeners. The polyurethane associated thickener has excellent flowing and leveling properties, is an excellent rheological modifier, can provide high shear viscosity, and can effectively improve the can opening effect of the paint, the film forming thickness, the leveling property, the luster, the water resistance and the like of the paint when being mixed with a cellulose derivative thickener for use. In certain embodiments of the present invention, nonionic associative thickeners are used in latex paints. In certain embodiments of the invention, hydrophobically modified ethoxylated urethane water-soluble polymers are used in latex paints. In an exemplary embodiment of the invention, TRM-003 leveling agent, commercially available from Delume, was used as the polyurethane associative thickener in the latex paint. In certain embodiments of the present invention, the polyurethane associative thickener is present in the latex paint in an amount ranging from 0.1% to 0.4%, preferably from 0.1% to 0.3%, and more preferably from 0.12% to 0.2%, based on the total weight of the latex paint.

In certain embodiments of the present invention, the total thickener content in latex paints according to the present invention may range from 0.15% to 0.9%, preferably from 0.3% to 0.6%, based on the total weight of the latex paint.

In certain embodiments of the present invention, latex paints according to the present invention comprise a pH adjusting agent. The proper pH value has certain influence on the storage stability, the anti-putrefaction, the corrosion resistance, the viscosity and the film coating performance of the coating. Commonly used pH adjusters in the coating art include aqueous ammonia, potassium hydroxide, and alkanolamines such as dimethylethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, multifunctional adjuvant AMP-95 (2-amino-2-methyl-1-propanol as a main component), and the like. In certain embodiments of the invention, alkanolamines are used as pH adjusting agents in latex paints in view of the irritating odor of ammonia, which affects water resistance. In an exemplary embodiment of the invention, AMP-95 is used as a pH adjusting agent in latex paints. In certain embodiments of the present invention, the latex paint contains from 0.1% to 0.4%, preferably from 0.1% to 0.3%, and more preferably from 0.15% to 0.25% of the pH adjusting agent, based on the total weight of the latex paint.

In certain embodiments of the present invention, latex paints according to the present invention comprise a dispersant/wetting agent. Dispersing/wetting agents are known to those skilled in the art to reduce the time and energy required to complete the dispersion process, stabilize the dispersed pigment dispersion, modify the surface properties of the pigment particles, and adjust the mobility of the pigment particles. In a preferred embodiment of the invention, the dispersant is selected from polycarboxylate dispersants, preferably hydrophobically modified polycarboxylate dispersants. In a preferred embodiment of the present invention, the wetting agent is selected from the group consisting of silicone-based wetting agents, octylphenol polyoxyethylene-based wetting agents, EO/PO-block copolymer-based wetting agents, and the like. In an exemplary embodiment of the invention, hydrophobically modified ammonium polycarboxylate dispersant SN-DISPERSANT 5027, commercially available from Nopulidae, is used as the dispersant in latex paints. In another exemplary embodiment of the invention, the hydrophobic wetting agent GENAPOL PF 20, commercially available from clariant, was used as a wetting agent in latex paints. In certain embodiments of the present invention, the dispersant is present in the latex paint in an amount of 0.3% to 1%, preferably 0.4% to 0.9%, and more preferably 0.6% to 0.8%, based on the total weight of the latex paint. In certain embodiments of the present invention, the latex paint has a humectant content of from 0.05% to 0.4%, preferably from 0.1% to 0.3%, more preferably from 0.13% to 0.2%, based on the total weight of the latex paint.

In certain embodiments of the present invention, the latex paint according to the present invention comprises titanium dioxide, i.e., titanium dioxide. The skilled person knows that titanium dioxide is an important white pigment in the field of coatings, and plays a role in covering. Titanium dioxide has the rutile and anatase types, with the rutile type being preferred here. In an exemplary embodiment of the invention, BLR699 rutile titanium dioxide, commercially available from Bailey corporation, was used in the latex paint. In certain embodiments of the present invention, the titanium dioxide content of the latex paint is from 10 to 25%, preferably from 15 to 20%, more preferably from 16 to 19%, based on the total weight of the latex paint.

The latex paint according to the present invention comprises heavy calcium, also known as ground calcium carbonate. The heavy calcium is white powder physically processed from calcite as raw material, and its main component is CaCO₃And are commonly used as fillers in coatings. In the present invention, for the purpose of increasing the sag resistance, and in view of increasing the roughness of the coating film without affecting the appearance of the multicolor system, a combination of heavy calcium of 80-200 mesh, preferably 120-200 mesh, more preferably 180-200 mesh and heavy calcium of 200-400 mesh, preferably 300-400 mesh, more preferably 325-400 mesh is used in the emulsion paint. The use of triple superphosphate in this combination in both particle size ranges surprisingly provides better sag resistance than either alone. In certain embodiments of the present invention, the amount of triple superphosphate in the latex paint is from 8% to 30%, preferably from 10% to 22%, more preferably from 11% to 16%. In a preferred embodiment of the present invention, from 4% to 20%, preferably from 5% to 15%, more preferably from 6% to 10% of triple superphosphate of 80-200 mesh, preferably 120-200 mesh, more preferably 180-200 mesh and from 3% to 15%, preferably from 4% to 10%, more preferably from 4.5% to 7% of triple superphosphate of 300-400 mesh, preferably 325-400 mesh, are used in the latex paint, based on the total weight of the latex paint.

In certain embodiments of the present invention, the latex paint according to the present invention comprises talc. Talc contains hydrous magnesium silicate as a main component, and is usually an aggregate of lumps, leaves, radial and fibrous, and when used in the coating material of the present invention, it can improve the crack resistance of the coating film and reduce the water permeability. In a preferred embodiment of the invention, 325-1250 mesh, preferably 600-1000 mesh talcum powder is used in the emulsion paint; in certain embodiments of the present invention, the amount of talc in the latex paint is from 2% to 10%, preferably from 3% to 7%, more preferably from 4% to 6%, based on the total weight of the latex paint.

In the present invention, however, the total amount of powder present in the latex paints according to the invention is preferably not greater than 45%, more preferably not greater than 40%, based on the total weight of the latex paint. The powder material comprises heavy calcium, talcum powder, titanium dioxide and the like and a combination thereof.

In the context of the present application, mesh count is expressed as the number of screen openings in a 1 inch (25.4mm) width screen. The sieve size is the size of the opening through which the particles can pass through the sieve. The larger the mesh number is, the finer the granularity of the material is; the smaller the mesh number, the larger the particle size of the material.

In certain embodiments of the present invention, the latex paints according to the present invention comprise a coalescent. The film-forming assistant is also called a coalescing assistant, can promote the plastic flow and elastic deformation of a high molecular compound, improves the coalescing performance, can form a film in a wider construction temperature range, and is a vanishing plasticizer. In certain embodiments of the present invention, coalescents include, but are not limited to, alcohols (e.g., benzyl alcohol, etc.), alcohol ethers (e.g., ethylene glycol butyl ether, propylene glycol phenyl ether, etc.), alcohol esters (e.g., dodecyl alcohol, hexadecyl alcohol, etc.), alcohol ether lipids (e.g., hexylene glycol butyl ether acetate, etc.), wherein the low temperature film forming properties of the alcohols are poor and hydrophilic, the low temperature film forming properties of the alcohol ethers are relatively good, but also somewhat hydrophilic, and the low temperature film forming properties of the alcohol esters are best, and the hydrophobicity is good. In a preferred embodiment of the invention, alcohol ester coalescents are used in latex paints. In a more preferred embodiment of the present invention, 12-alcohol ester (also called alcohol ester twelve, and all called 2, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate) is used in the emulsion paint, which is a safe and efficient novel auxiliary agent suitable for various synthetic resin latex paints, and is an ideal auxiliary agent for green paints. Compared with the common film-forming additive, the alcohol ester twelve has the following advantages: the resin has good phase solubility, small dosage, low film forming temperature, good film leveling property, good color development, low freezing point, good hydrolytic stability, low toxicity and the like. In certain embodiments of the present invention, the latex paint contains the coalescent in an amount of 1% to 5%, preferably 1.5% to 4%, and more preferably 1.8% to 3%, based on the total weight of the latex paint.

In certain embodiments of the present invention, the latex paints according to the present invention comprise an anti-freeze agent. An antifreeze is a substance that prevents freezing of water in a material at low temperatures. In certain embodiments of the invention, the antifreeze agents include lower alcohols, glycols, alcohol ethers, chlorinated hydrocarbons, amides, and the like. In certain embodiments of the invention, the antifreeze agent comprises methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol butyl ether, propylene glycol butyl ether, ethylene glycol butyl ether acetate, methylene chloride, 1, 2-dichloroethane, dimethyl sulfoxide, formamide, calcium chloride, sodium acetate, magnesium chloride, and the like. Antifreeze agents more commonly used in the art are selected from ethylene glycol and propylene glycol. In the most preferred embodiment of the present invention, propylene glycol is used in latex paints, considering that ethylene glycol has high toxicity and is likely to pose a health hazard to humans. In certain embodiments of the present invention, the latex paint has an antifreeze content of from 0.5% to 2%, preferably from 0.5% to 1.5%, more preferably from 0.8% to 1.2%, based on the total weight of the latex paint.

In certain embodiments of the present invention, the latex paints according to the present invention comprise a water repellent. In certain embodiments of the invention, an aqueous, organic solvent-free, silicone-modified emulsion-type adjuvant is used in latex paints, which has a hydrophobic effect. The inventors of the present invention have found that the resistance to the overbasing can be particularly advantageously improved by using a water repellent, particularly in specific amounts as described below. In a preferred embodiment of the invention, the latex paint is one having aminoalkyl groups (e.g., amino C) ₁-C₁₀Alkyl) polydimethylsiloxane aqueous emulsions. For example, SILRES BS 1306CN water repellent, commercially available from wacker, may be used in the latex paint. In certain embodiments of the present invention, the water repellent is present in the latex paint in an amount of 0.1% to 1%, preferably 0.15% to 0.7%, and more preferably 0.18% to 0.3%, based on the total weight of the latex paint.

In certain embodiments of the present invention, latex paints according to the present invention comprise a mold and preservative. In certain embodiments of the invention, the mildewcide preservative comprises a nitrogen-containing heterocyclic compound. In certain embodiments of the present invention, the mildewcide preservative comprises an isothiazolinone. Preferably, the mildewcide preservative comprises 2-methyl-4-isothiazolin-3-one (MIT) and 1, 2-benzisothiazolin-3-one (BIT) and combinations thereof. Such a mildewcide preservative may be selected, for example, from ACTICIDE MBS, commercially available from THOR. In certain embodiments of the present invention, the amount of mold and preservative present in the latex paint is from 0.1% to 0.3%, preferably from 0.15% to 0.25%, and more preferably from 0.18% to 0.22%, based on the total weight of the latex paint.

From the viewpoint of solving the technical problem of the present invention, the acrylic emulsion content in the latex paint according to the present invention should be controlled to 37% to 55%, preferably 40% to 53%, more preferably 45% to 51%, based on the total weight of the latex paint.

Further, the acrylic emulsion includes a vinyl monomer, an alkyl (meth) acrylate, and a high-density crosslinking monomer. Preferably, the vinylic monomer comprises styrene and derivatives thereof. Preferably, the alkyl (meth) acrylate is (meth) acrylic acid (C)₁-C₁₀) Alkyl esters, preferably (meth) acrylic acid (C)₃-C₈) Alkyl ester, more preferably (meth) acrylic acid (C)₃-C₆) An alkyl ester. More preferably, the alkyl (meth) acrylate includes n-propyl (meth) acrylate, n-butyl (meth) acrylate, isooctyl (meth) acrylate, and combinations thereof. Preferably, the high density crosslinking monomer is selected from linear, branched or cyclic C with at least two hydroxyl groups₂-C₁₀Alkanes, acrylates of polyols and acrylates of alkoxylated polyols, or combinations thereof. In the inventionWithin the scope, the polyol comprises a linear, branched or cyclic C optionally having ether groups₁-C₁₈Preferably C₂-C₁₂An aliphatic polyol of (1). In a preferred embodiment of the invention, the C is a linear, branched or cyclic C having at least two hydroxyl groups₂-C₁₀The alkane includes dimethylolethane, trimethylolethane, trimethylolpropane, trihydroxybutane, trimethylolbutane, dimethylolcyclobutane, and combinations thereof. In a preferred embodiment of the present invention, the acrylate of the polyol comprises a diacrylate, triacrylate or higher acrylate, such as glycerol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and combinations thereof. In a preferred embodiment of the present invention, the acrylate of the alkoxylated polyol comprises a diacrylate, triacrylate or higher acrylate, such as ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate and combinations thereof. More preferably, the high density crosslinking monomer comprises trimethylolpropane, propoxylated glycerol triacrylate, dipentaerythritol hexaacrylate, or combinations thereof. Preferably, in the case of using two crosslinking monomers (for example trimethylolpropane and propoxylated glycerol triacrylate, or trimethylolpropane and dipentaerythritol hexaacrylate, or propoxylated glycerol triacrylate and dipentaerythritol hexaacrylate), their ratio may be 10: 1 to 1: 10, preferably 5: 1 to 1: 5, more preferably 3: 1 to 1: 3. preferably, in the case of using three crosslinking monomers, their ratio is preferably from 1 to 10: 1 to 10: 1 to 10, more preferably 1 to 5: 1 to 5: 1 to 5. In a preferred embodiment, the acrylic emulsion comprises 5 to 20%, preferably 10 to 15%, styrene, 5 to 20%, preferably 10 to 15%, n-butyl acrylate, 5 to 20%, preferably 10 to 15%, isooctyl acrylate, and 1 to 5%, preferably 2 to 4%, high density crosslinking monomer, based on the total weight of the acrylic emulsion.

In certain embodiments of the present invention, the latex paint according to the present invention comprises water. In a preferred embodiment of the present invention, latex paints contain 8-20% water, preferably 9-17% water, more preferably 10-15% water, in addition to water contained in other components.

In certain embodiments of the present invention, the sand-in-sand multicolor coating system comprises the latex paint as described above, and further comprises a sand-in-sand multicolor coating and an optional overcoat.

In certain embodiments of the present invention, the sand-in-sand multicolor coating system comprises, preferably consists of:

a) the coating layer formed by the latex paint as described above,

c) optionally, a finish formed from a finish varnish comprising a clear acrylic emulsion, an anti-freeze agent, a polyurethane thickener, and a defoamer.

Sand-in-SAND multicolor coatings typically comprise an elastomeric emulsion, a silicone-acrylic emulsion, a protective gum, kaolin, SAND, and the like, which are products known per se to the skilled artisan and commonly found on the market, such as the gorgeon high color PAINT commercially available from PPG (product code SSN-P8000, British name POLYCHROME PAINT-WITH SAND). The preparation of sand-in-sand multicolor coatings generally comprises the following steps: the base paint such as latex paint is mixed with sand and the prepared protective glue solution, then color paste is added according to the color of the stone for color mixing, and then granulation is carried out in the protective glue solution. Then all the colored point particles are mixed according to the proportion of the required stone effect, and the emulsion phase containing the white sand is added into the mixed phase of all the colored points. The sand used may be a ground product from natural ore or sintered color sand, white sand or color sand with other colors. Preferably, white sand is used in the sand-in-sand multicolor coating system, and is modulated by color paste, so that various colors, such as black, red, yellow and the like, are formed. In sand-in-sand multicolor coatings, the sand is distributed in both the dispersed and continuous phases and generally contains less sand than real mineral varnish products prepared by directly mixing the colored sand with an auxiliary agent such as an emulsion or a thickener, and the sand content is generally less than 40%, for example less than 35%, based on the total weight of the sand-in-sand multicolor coating.

In an exemplary embodiment, the sand-in-sand multicolor paint comprises, based on the total weight of the sand-in-sand multicolor paint, from 30% to 45%, preferably from 33% to 42%, water, from 0.15% to 0.35%, preferably from 0.2% to 0.3%, of an antifoaming agent (e.g., CF 1365 mineral oil commercially available from BLACKBURN), from 0.1% to 0.25%, preferably from 0.12% to 0.2%, of a sodium polycarboxylate dispersant (e.g., SN 5040 commercially available from nop), from 1% to 10%, preferably from 3% to 8%, kaolin clay, from 5% to 10%, preferably from 6% to 9%, an elastomeric emulsion, from 15% to 30%, preferably from 18% to 25%, a silicone emulsion, from 1.5% to 3.0%, preferably from 2% to 2.5% of a film forming aid (e.g., 12-alcohol ester), from 0.5% to 1.5%, preferably from 0.7% to 1.3% of an antifreeze agent (e.g., propylene glycol), 0.3% to 0.8%, preferably 0.4% to 0.7% of a cellulose thickener (e.g. 250HBR commercially available from ashland), 0.7% to 2%, preferably 0.9% to 1.7% of a protective gum (e.g. lithium magnesium silicate protective gum), 20% to 40%, preferably 25% to 35% of fine sand (triple superphosphate) and/or 0.2% to 0.5%, preferably 0.3% to 0.45% of a polyurethane thickener (e.g. RM-8W commercially available from dow).

Finishes, in particular suitable FOR the sand-in-sand multicolour finishes, are also known per se to the skilled worker and are commercially available, FOR example the brilliant rock special finish commercially available from PPG (product code SVN-9900, British name MATT TOPCOATING FOR POLYCHROME COATING). In an exemplary embodiment, the finish coat comprises, based on the total weight of the finish coat, 40% to 50%, preferably 42% to 58% water, 40% to 55%, preferably 43% to 52% acrylic emulsion, 2% to 3%, preferably 2.2% to 2.8% coalescent (e.g., 12-alcohol ester), 1% to 2%, preferably 1.2% to 1.8% antifreeze (e.g., propylene glycol), 0.2% to 0.5%, preferably 0.25% to 0.45% polyurethane thickener (e.g., RM-8W commercially available from dow), and/or 0.1% to 0.2%, preferably 0.12% to 0.18% defoamer (e.g., CF 107 mineral oil commercially available from BLACKBURN).

The invention also relates to a substrate, in particular a building substrate, coated with the sand-in-sand multicolor coating system, wherein the substrate comprises a wall body, such as an inner wall, an outer wall, concrete coated with a putty layer on the surface, and the like of a building.

In addition, the invention also relates to a preparation method of the emulsion paint. In an exemplary embodiment, the preparation of latex paints may include the steps of:

(a) a toothed dispersion plate is arranged on a dispersion and stirring multi-purpose machine, a clean tank is placed and clamped, water is added into the tank, a defoaming agent and a cellulose thickening agent are added under the condition of slow stirring (300-,

(b) stirring at medium speed (600-800r/min) for 3-7 min, sequentially adding pH regulator, dispersant and wetting agent,

(c) adding titanium pigment, 800-mesh talcum powder and 325-mesh heavy calcium after 3-7 minutes at medium speed (600-800r/min),

(d) the rotating speed is increased to 1100-1500r/min, the mixture is stirred for 20-30 minutes, then the emulsion, the mildew-proof preservative, the film forming additive, the antifreezing agent and the waterproofing agent are added in sequence,

(e) stirring at medium speed (600-800r/min) for 3-7 min, adding 200 mesh calcium bicarbonate, polyurethane thickener and defoamer,

(f) stirring at medium speed (600-800r/min) for 5-10 min to obtain the latex paint.

Examples

Embodiments of the present invention will be described in detail below by way of examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and are not intended to limit the scope of the present invention. Various objects and advantageous aspects of the present invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments. All parts and percentages in the examples, as well as throughout the specification, are by weight unless otherwise indicated.

The latex paint was prepared as follows:

a toothed dispersion disc is installed on a dispersion and stirring multi-purpose machine, a clean tank (2L) is placed and clamped, water is added into the tank, an antifoaming agent and a cellulose thickening agent are added under the stirring of a slow speed (400r/min), a pH regulator, a dispersing agent and a wetting agent are sequentially added after stirring of a medium speed (700r/min) for 5 minutes, titanium dioxide, 800-mesh talcum powder and 325-mesh heavy calcium are added after stirring of a medium speed (700r/min), the rotating speed is increased to 1300r/min, stirring is carried out for 25 minutes, then emulsion, a mildew-proof preservative, a film forming aid, an antifreezing agent and a waterproof agent are sequentially added, after stirring of a medium speed (700r/min) for 5 minutes, 200-mesh heavy calcium, a polyurethane thickening agent and an antifoaming agent are added, and stirring of a medium speed (700r/min) for 10 minutes, and the emulsion paint is obtained.

Key Performance comparison test

1. Screening of emulsions

The raw materials of the latex paint are as follows:

water, in a ratio of 2: DISPELAIR CF 107 from BLACKBURN and DAPRO DF 7079 CN from Hamming moded, 250HBR, AMP-95 from Ashland, hydrophobically modified ammonium polycarboxylate salt dispersant SN-DISPERSANT 5027 from Nopulidae, the hydrophobic wetting agent GENAPO PF 20 from Clarian, BLR699 rutile titanium dioxide from Bailey, 200 mesh calcium bicarbonate, 325 mesh calcium bicarbonate, 800 mesh talc, emulsions, 12-alcohol ester film formers, propylene glycol, RES BS 1306CN waterproofing agent from Wake, ACTICIDE MBS from THOR and ZELMERM 003 levelling agents.

The specific composition of formulation 3 is as follows:

which comprises the following components in percentage by weight: 10% of water, 0.5% of a water-soluble polymer in a weight ratio of 2: 85107 of BLACKBURN and DAPRO DF 7079 CN of the modest family Hamming, 0.14% of 250HBR of the modest family Hamming, 0.2% of AMP-95, 0.7% of hydrophobically modified polycarboxylate ammonium salt dispersant SN-3550284 CN of the family Nopulidae, 0.15% of a partially hydrophobic wetting agent GENAPOL PF 20 of the family Laine, 18% of BLR699 rutile titanium dioxide of the Bailey family, 7% of calcium heavy 200 mesh, 5% of calcium heavy 325 mesh, 4.26% of talc 800 mesh, 50% of an acrylic emulsion comprising 12.5% of styrene, 12.5% of n-butyl acrylate, 12.5% of isooctyl acrylate and 3% of a high density crosslinking monomer comprising trimethylolpropane, propoxylated glycerol acrylate, 2.5% of pentaerythritol hexaacrylate, 2.12 to 12% of a film-forming adjuvant, 1% propylene glycol, 0.2% SILRES BS 1306CN water repellent available from watt, 0.2% ACTICIDE MBS available from THOR, and 0.15% zelmer TRM-003 leveling agent.

The general description of emulsions 1 to 2 and 4 to 6 is as follows:

emulsion 1: the styrene/acrylate copolymer emulsion has the lowest film-forming temperature of 20 ℃, is an anionic emulsion polymer with medium viscosity, and is mainly used for emulsion paint and texture coating;

emulsion 2: styrene/acrylate copolymerization type anionic emulsion, the lowest film forming temperature is 22 ℃, and the particle size is fine (0.1-0.2 mu m), and the emulsion is mainly used in primer;

emulsion 4: the styrene/acrylate copolymerization type anionic emulsion has the lowest film forming temperature of 21 ℃, is suitable for general inner and outer wall coatings, has fine particle size (0.1-0.2 mu m), and does not contain protective colloid;

emulsion 5: the styrene/acrylate copolymerization type anionic emulsion has the lowest film forming temperature of 16 ℃, and is an alkali-resistant emulsion used in concrete;

emulsion 6: acrylic polymer emulsion, 100 percent acrylic polymer emulsion and 18 ℃ of minimum film forming temperature, and is suitable for various coating formula systems;

remarking: emulsion 3 differs primarily from emulsions 1-2 and 4-6 in that emulsions 1-2 and 4-6 are free of the crosslinking monomer in emulsion 3.

6 samples of "formulation 1" to "formulation 6" were prepared using the same method (6 formulations were made with the same parts of solids added to the emulsion, the other raw material adjuvants were kept at the same ratio, and if the total of the formulations was not equal to 100%, the fine adjustment was made using the amount of water) except for the selection of the emulsions, and then the following relevant tests were performed as shown in Table 1 below.

TABLE 1

Remarking:^awater permeability,^bThe saltpetering resistance salting-out test method and the evaluation standard are according to JGT 210-2018 primer for internal and external walls of buildings, which is incorporated by reference;

covering rate, weather resistance,^cAdhesion test methods and evaluation standards were in accordance with GB/T9755-2014 synthetic resin emulsion exterior wall coatings, which is incorporated herein by reference;

^dthe test method of the outdoor early-stage anti-whiskering challenge experiment is as follows: preparing materials: PPG flexible exterior wall putty produced by oneself (GBT 23455-; secondly, construction: the prepared putty is scraped twice on an outdoor wall (the interval is 4 hours, the total thickness is about 2mm), and after being dried for 24 hours, the putty is respectively coated once by rolling (0.13 kg/m)²) Latex paints of formulations 1 to 6 (diluted with 10% water, 3% carbon black paste) were dried for 24 h; testing: spraying tap water for 4h and observing the surface condition of the coating after 24 h; the rating for the anti-whiskering salting-out and the outdoor early anti-whiskering challenge experiments is expressed as a value from 0 to 5, where "0" represents the worst and "5" represents the best.

As can be seen from the above test results of table 1, formulation 3 using emulsion 3 exhibited the best water permeability, saltpetering resistance, adhesion, and performance in the outdoor early saltpetering challenge test. Thus, in combination, formulation 3 using emulsion 3 achieved the best overall performance.

2. Adjusting the addition amount of the emulsion

In the above formulation (formulation 3), the amount of emulsion 3 (film-forming aid 5% of the emulsion) was adjusted to give the following 4 formulations (the total formulation was not equal to 100% due to the adjustment of the emulsion amount, the amount of water was finely adjusted, and the ratios of other raw material aids were kept the same):

TABLE 2

Remarking: the test methods for the various properties are the same as those listed in the remarks of Table 1

As can be seen from the data in Table 2, formula iv exhibits excellent water permeability, resistance to saltpetering, and performance in outdoor early anti-saltpetering challenge experiments.

As can be seen from the data in Table 2, the effect of the addition amount of the emulsion on the performance such as the resistance to the efflorescence is large, mainly because when the amount of the emulsion is insufficient, the compactness of the coating film is poor, moisture is easy to permeate, and alkali and salt are brought out to the surface of the coating film; when the emulsion is in a sufficient amount, the properties such as the blocking property of the emulsion are fully embodied, so that the continuous addition of the emulsion is meaningless, and the unnecessary formulation cost is increased.

3. Proportioning of heavy calcium powder (anti-sagging property)

In the formula (formula 3), the addition amounts of 325-mesh and 200-mesh coarse whiting are further adjusted to obtain the following 3 formulas (the mixture ratios of other raw material auxiliaries are kept the same):

TABLE 3

Remarking:^aanti-sagging test method, namely, spraying sand-coated sand with multiple colors (the dosage is 1.2 Kg/m) on 3A 4 cement boards which are roll-coated and dried for 48 hours²) Immediately thereafter, the plate was kept nearly upright (3 plates were kept at the same upright angle as much as possible), and sagging was observed after 24 hours. Sag resistance evaluation criterion- "0" means worst, all dropped; "5" means best, no sagging.

When the emulsion paint is used in cooperation with sand bag sand in a colorful mode, after colorful spraying is carried out, colorful dots cannot flow down, and particularly, the spraying amount at one time is large (1.2 kg/m)²-1.5kg/m²) In the case of (1). Experimental tests prove that the coating has a rough coating surface effect and the best anti-sagging performance.

4. Addition amount of the water repellent

In the formula (formula 3), the amount of the water repellent was further adjusted to obtain the following 4 formulas (the total amount of the formulas was not equal to 100% due to the adjustment of the amount of the water repellent, the amount of water used was finely adjusted, and the ratios of other raw material auxiliaries were kept the same):

TABLE 4

Remarking: the above properties are referred to in tables 1 and 3 for remarks

The water repellent was SILRES BS 1306CN water repellent available from wacker. As can be seen from the data in Table 4, the addition of the water repellent can lower the water permeability value, further improve the corresponding saltpetering resistance, and even enable challenging experiments by outdoor extremes. Specifically, when the water repellent was added in an amount of 0.20% (formulation b), the optimum saltpetering resistance, outdoor early saltpetering challenge test and sag resistance, and water permeability close to formulations c and d were achieved. When the addition amount of the waterproofing agent is 0.8 percent (formula d), the anti-sagging performance is obviously reduced relative to the formula b, because when the addition amount of the waterproofing agent is more, the surface tension of a coating film becomes smaller, so that the anti-sagging performance is reduced because the coating film is not easy to spread when the sprayed sand-coated sand is colorful.

5. Performance comparison test with conventional primer/multicolor basecoat

The formulation of example 1 was the same as formulation 3 above;

traditional priming paint: PPG multifunctional seal primer (product code SNP-1000, English name NEOPRIM)

Colorful intermediate coating: pompe 900 of PPG (product code SPX-P100N, British name PANTEX 900 NF (P));

TABLE 5

Remarking: the water permeability, the saltpetering resistance, the adhesion testing method and the evaluation standard are all according to the primer for the inner and outer walls of the building of JGT 210-2018; the test method and the evaluation standard of the covering rate and the weather resistance are both in accordance with GB/T9755-2014 synthetic resin emulsion exterior wall coating; the test method of the outdoor early-stage anti-whiskering challenge experiment refers to the remark part in table 1; the sag resistance test method is remarked with reference to table 3, and the rating criteria are expressed by numerical values of 0 to 5, "0" for worst, "5" for best.

From the comparative data in Table 5 above, it can be seen that the overall performance of the latex paint of the present invention (example 1) is significantly better than that of the conventional primer (comparative example 1) and the multicolor basecoat (comparative example 2), and the performance of the conventional primer plus multicolor basecoat composite layer (comparative example 3) can be achieved, even better in terms of water permeability and sag resistance.

Thus, it can be seen from the above experimental results that the latex paints of the present invention possess the excellent properties described above and are therefore suitable for use in sand-in-sand multicolor systems.

6. Sand-in-sand multi-color system key performance test

The application of the coating of the system of the invention comprises the following steps:

a concrete substrate was prepared, a putty layer was applied thereon, and then the latex paint, sand-in-sand multicolor paint, and finishing varnish of formulation 3 of the present invention were applied by roll coating, spray coating, and roll coating, respectively.

The application of the conventional system comprises the following steps:

preparing a concrete substrate, applying a putty layer on the concrete substrate, and then applying a primer, a colorful middle coat, a sand-in-sand colorful and a finishing varnish through roll coating, spraying and roll coating respectively.

Conventional system (comparative example a): primer (PPG multifunctional seal primer (product code SNP-1000, English name NEOPRIM)) + multicolor middle coat (PPG product code SPX-P100N, English name PANTEX 900 NF (P)) + SAND-coated SAND colorful (PPG colorful rock precious color PAINT (product code SSN-P8000, English name POLYCHROME PAINT-WITH SAND)) + overcoat varnish (PPG rock special overcoat (product code SVN-9900, English name MATT TOPCOATING FOR POLYCHROME COATING))

Inventive system 1 (example B): latex PAINT (formula 3) + Sand-in-SAND multicolor (PPG gorgeous rock refined color PAINT (product code number SSN-P8000, English name POLYCHROME PAINT-WITH SAND)) + finishing varnish (PPG gorgeous rock special finishing PAINT (product code number SVN-9900, English name MATT TOPCOATING FOR POLYCHROME COATING))

TABLE 6

Remarking: the above test methods are described in HG/T4343-.

From the test results in Table 6, the performance of example B is equivalent to that of comparative example A, and both can meet the relevant national standards (HG/T4343-.

Each feature and embodiment described above and combinations thereof may be referred to as being included in the invention. Accordingly, the present invention is directed to the following non-limiting aspects:

1. a latex paint comprising: 37-55% of acrylic emulsion, a water-proofing agent and a combination of 80-200 mesh heavy calcium carbonate and 300-400 mesh heavy calcium carbonate, wherein the acrylic emulsion comprises a high-density crosslinking monomer which is selected from linear, branched or cyclic C with at least two hydroxyl groups₂-C₁₀Alkanes, acrylates of polyols and acrylates of alkoxylated polyols or combinations thereof, wherein the percentages are based on the total weight of the latex paint.

2. The latex paint of aspect 1, wherein said latex paint further comprises at least one auxiliary selected from the group consisting of: defoaming agents, thickeners such as cellulose thickeners and polyurethane associative thickeners, pH regulators, dispersants, wetting agents, rutile titanium dioxide, talc, film-forming aids, anti-freeze agents, and/or mildew-proof preservatives.

3. The latex paint according to any one of the preceding aspects, wherein said C is linear, branched or cyclic and has at least two hydroxyl groups₂-C₁₀The alkane includes dimethylolethane, trimethylolethane, trimethylolpropane, trihydroxybutane, trimethylolbutane, dimethylolcyclobutane, and combinations thereof.

4. The latex paint according to any of the preceding aspects, wherein the acrylate of the polyol comprises a diacrylate, triacrylate or higher acrylate, such as glycerol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and combinations thereof.

5. The latex paint according to any of the preceding aspects, wherein the acrylate of the alkoxylated polyol comprises a diacrylate, triacrylate or higher acrylate, such as ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate and combinations thereof.

6. The latex paint according to any one of the preceding aspects, wherein the content of the water repellent is 0.1% to 1%, preferably 0.15% to 0.7%, more preferably 0.18% to 0.3%.

7. The latex paint of any of the previous aspects, wherein the water repellent comprises an aqueous, organic solvent-free, silicone-modified emulsion-type adjuvant.

8. The latex paint of aspect 7 wherein said water repellent comprises an aqueous emulsion of polydimethylsiloxane.

9. The latex paint of aspect 8, wherein the polydimethylsiloxane bears aminoalkyl groups.

10. The latex paint of any of the preceding aspects, wherein the acrylic emulsion further comprises a vinyl monomer and an alkyl (meth) acrylate.

11. The latex paint of aspect 10, wherein said vinylic monomer comprises styrene and its derivatives.

12. The latex paint of aspect 10 or 11, wherein the alkyl (meth) acrylate comprises n-propyl (meth) acrylate, n-butyl (meth) acrylate, isooctyl (meth) acrylate, and combinations thereof.

13. The latex paint according to any of the preceding aspects, wherein said high density crosslinking monomer comprises trimethylolpropane, propoxylated glycerol triacrylate, dipentaerythritol hexaacrylate, or combinations thereof.

14. The latex paint according to any one of aspects 1 to 11, characterized in that the acrylic emulsion comprises 5-20%, preferably 10-15% of styrene, 5-20%, preferably 10-15% of n-butyl acrylate, 5-20%, preferably 10-15% of isooctyl acrylate and 1-5%, preferably 2-4% of high density crosslinking monomer based on the total weight of acrylic emulsion.

15. The latex paint according to any one of the preceding aspects, characterized in that the acrylic emulsion is present in an amount of 40% to 53%, preferably 45% to 51%, based on the total weight of the latex paint.

16. The latex paint according to any one of the preceding aspects, wherein the content of the combination of 80-200 mesh heavy calcium carbonate and 300-400 mesh heavy calcium carbonate is 12-25%, preferably 13-18%, based on the total weight of the latex paint.

17. The latex paint according to any of the preceding aspects, characterized in that said latex paint comprises 4% -20%, preferably 5% -15%, more preferably 6% -10% of triple superphosphate of 80-200 mesh and 4% -10%, more preferably 4.5% -7% of triple superphosphate of 300-400 mesh, based on the total weight of said latex paint.

18. A sand-in-sand multicolor coating system comprising:

a) a coating formed from the latex paint of any one of aspects 1 to 17,

b) the coating is formed by sand-in-sand multicolor paint, and both a disperse phase and a continuous phase in the sand-in-sand multicolor paint contain sand.

19. The sand-in-sand multicolor coating system of aspect 18, further comprising:

c) an overcoat formed from an overcoat varnish.

20. The sand-in-sand multicolor coating of aspect 19, wherein the overcoat varnish comprises a acrylic emulsion.

21. The sand-in-sand multicolor coating of aspect 18 or 19, consisting of:

a) a coating formed from the latex paint of any one of aspects 1 to 17,

b) the coating is formed by sand-in-sand multicolor paint, and both a disperse phase and a continuous phase in the sand-in-sand multicolor paint contain sand;

c) and (6) an overcoat layer.

22. A method of making a latex paint comprising mixing the components of the latex paint of any of aspects 1 to 17.

23. Use of the latex paint according to any one of aspects 1 to 14 in a coating system for an exterior wall of a building, preferably in a sand-in-sand multicolor coating system, wherein the sand-in-sand multicolor coating system is in particular according to any one of aspects 18 to 21.

24. A substrate, in particular a building substrate, coated with the sand-in-sand multicolor coating system of any of aspects 18 to 21.

While specific embodiments of the invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A latex paint comprising: 37-55% of acrylic emulsion, a water-proofing agent and a combination of 80-200 mesh heavy calcium carbonate and 300-400 mesh heavy calcium carbonate, wherein the acrylic emulsion comprises a high-density crosslinking monomer which is selected from linear, branched or cyclic C with at least two hydroxyl groups ₂-C₁₀Alkanes, acrylates of polyols and acrylates of alkoxylated polyols or combinations thereof, wherein the percentages are based on the total weight of the latex paint.

2. The latex paint of claim 1 wherein said latex paint further comprises at least one auxiliary selected from the group consisting of: defoaming agents, thickeners such as cellulose thickeners and polyurethane associative thickeners, pH regulators, dispersants, wetting agents, rutile titanium dioxide, talc, film-forming aids, anti-freeze agents, and/or mildew-proof preservatives.

3. The latex paint according to any of the preceding claims, characterized in that said C, linear, branched or cyclic, having at least two hydroxyl groups₂-C₁₀The alkane includes dimethylolethane, trimethylolethane, trimethylolpropane, trihydroxybutane, trimethylolbutane, dimethylolcyclobutaneAnd combinations thereof.

4. The latex paint according to any of the preceding claims wherein the acrylate of polyol comprises diacrylate, triacrylate or higher acrylates such as glycerol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate and combinations thereof.

5. The latex paint according to any of the preceding claims, wherein the acrylate of said alkoxylated polyol comprises diacrylate, triacrylate or higher acrylates, such as ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate and combinations thereof.

6. The latex paint according to any one of the preceding claims, characterized in that the content of water repellent is 0.1% to 1%, preferably 0.15% to 0.7%, more preferably 0.18% to 0.3%.

7. The latex paint of any one of the preceding claims in which the water repellent agent comprises an aqueous, organic solvent-free silicone-modified emulsion-type adjuvant.

8. The latex paint of claim 7 in which said water repellent comprises an aqueous emulsion of polydimethylsiloxane.

9. The latex paint of claim 8 in which the polydimethylsiloxane bears aminoalkyl groups.

10. The latex paint of any of the previous claims in which the acrylic emulsion further comprises a vinyl monomer and an alkyl (meth) acrylate.