CN112961514B - Inorganic silicate as-cast finish concrete coating and preparation method and application thereof - Google Patents

Abstract

The invention relates to a coating and a preparation method and application thereof. The coating comprises, by mass, 5-8% of styrene-acrylic emulsion, 5-20% of potassium silicate, 15-30% of silica sol, 15-18% of titanium dioxide, 15-20% of filler, 1.6-4.5% of auxiliary agent, 0.5-1% of organosilicon hydrophobic agent, 0.2-0.4% of color mixing paste and the balance of water; wherein the potassium silicate is silane modified potassium silicate, and the modulus is 3.5-4.0; the silica sol is subjected to a stabilization treatment. The adhesive system consists of styrene-acrylic emulsion, potassium silicate and silica sol with specific content, the silicate has better permeability, can react with a cement wall body and can permeate into a wall body base material, so that the binding force is strong, the styrene-acrylic emulsion improves the wrapping property of the coating to powder, and the potassium silicate and the silica sol have synergistic effect to improve the cohesion and the crack resistance of a coating film. The coating has good stability, and the prepared paint film has weak gloss sense and good and vivid effect of imitating the clear water concrete; and the paint film has strong binding force with the base material, is not easy to peel off and has good yellowing resistance.

Description

Inorganic silicate imitation fair-faced concrete coating and preparation method and application thereof

technical field

The invention relates to the technical field of architectural decoration, in particular to an inorganic silicate imitation fair-faced concrete coating and a preparation method and application thereof.

Background technique

Fair-faced concrete is an expression method of architectural modernism, and it is also called decorative concrete because of its decorative effect. The production method of fair-faced concrete is that after the concrete is poured, there is no more coating, tile, stone and other materials, and the natural surface effect of cast-in-place concrete is directly used as the finish. , uniform color, sharp edges and corners, no damage and pollution. Due to the unique aesthetic performance of the fair-faced concrete structure, it is loved by the majority of designers.

However, there are also many problems in the manufacturing process of fair-faced concrete. For example, due to the lack of decoration works after removing the formwork, its quality is roughly determined at the stage of forming the formwork. The design of concrete ratio and the quality control of raw materials require each piece The proportion of cement used in concrete should be strictly consistent; the newly mixed concrete must have good workability and cohesion, and layering and segregation is not allowed; The particles are uniform.

In addition, cast-in-place concrete uses cement as the main inorganic binder. After the cement is mixed with water, it will form a hydration process. This hydration will generate shrinkage stress, and cracks will occur on the surface of the hydrated concrete. Crack-resistant fibers are still difficult to completely eliminate the risk of cracking.

The shortcomings of traditional fair-faced concrete mainly include the following aspects: 1) The cement-based content in the cast-in-place fair-faced concrete is high, and free calcium ions are generated during the hydration process, which is prone to the phenomenon of "pan-alkali"; 2) The cast-in-place fair-faced concrete is easy to The surface color is uneven; 3) The cast-in-place fair-faced concrete is a one-time molding, and once a defect occurs, it is difficult to repair.

In order to solve the shortcomings of the above-mentioned fair-faced concrete, a method of imitating the effect of fair-faced concrete through paint has appeared. Traditional fair-faced concrete imitation methods are mainly divided into two imitation systems: organic imitation fair-faced concrete system and inorganic dry powder veneer mortar imitation fair-faced concrete system. The organic imitation fair-faced concrete system is mostly imitated by adding color paste to the organic latex paint product. This kind of organic imitation fair-faced concrete system can only form a paint film on the concrete surface, so the bonding force is weak. Over time, some common problems of latex paint such as peeling, peeling, and yellowing appear in the paint film, which will greatly reduce the effect of imitating fair-faced concrete. In addition, the latex paint film has good sealing performance, the product is airtight, and the paint film has a strong luster, which will also cause a big difference in touch and appearance from inorganic fair-faced concrete, so it can only be viewed from a distance, not close-up. Inorganic dry powder veneer mortar imitation fair-faced concrete system uses dry powder veneer mortar to add color powder for color matching. The salt and alkali in the dry powder itself can easily lead to the problem of efflorescence, and it is difficult to control the use of color powder to color, which can easily lead to color difference between batches and stubble. question. Therefore, the general organic imitation fair-faced concrete system and the inorganic dry powder finishing mortar imitation fair-faced concrete system have unsatisfactory preventive effects.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide an inorganic silicate imitating fair-faced concrete coating with strong binding force and good imitating effect of fair-faced concrete, and a preparation method and application thereof.

One aspect of the present invention provides a kind of inorganic silicate imitation fair-faced concrete coating, according to mass percentage, comprises the following components:

Wherein, the potassium silicate is potassium silicate modified by silane, and the modulus of the potassium silicate is 3.5-4.0; the silica sol is stabilized; and the pH of the coating is 9-10.

In some of the embodiments, the content of the potassium silicate is 5% to 10% in terms of mass percentage.

In some of the embodiments, the content of the silica sol is 15% to 20% in terms of mass percentage.

In some embodiments, the content of the styrene-acrylic emulsion is 6%; the content of the potassium silicate is 5%; and the content of the silica sol is 15% in terms of mass percentage.

In some of these embodiments, the minimum film-forming temperature of the styrene-acrylic emulsion is not higher than 5°C.

In some of these embodiments, the titanium dioxide is of the rutile type.

In some embodiments, the filler is selected from at least one of heavy calcium and quartz powder.

In some of these embodiments, the adjuvant comprises the following components according to the mass percentage of the inorganic silicate imitation fair-faced concrete coating:

On the other hand of the present invention, also provides a kind of preparation method of inorganic silicate imitation fair-faced concrete coating, comprises the following steps:

Get each component of above-mentioned inorganic silicate imitation fair-faced concrete coating for subsequent use;

Stir and mix an appropriate amount of water and the auxiliary agent into a colloidal substance;

Add the titanium dioxide and the filler to the colloidal substance, and grind;

Add the styrene-acrylic emulsion, and mix;

Add the potassium silicate, the silica sol, the organosilicon hydrophobic agent and the remaining water in turn, and mix well;

The said coloring paste is added to obtain an inorganic silicate imitation fair-faced concrete coating.

Another aspect of the present invention also provides the application of the above-mentioned inorganic silicate imitating fair-faced concrete coating as imitating fair-faced concrete.

The inorganic silicate imitation clear-water concrete coating of the present invention comprises styrene-acrylic emulsion, potassium silicate, silica sol, titanium dioxide, filler, auxiliary agent, organic silicon hydrophobic agent toning paste and water, specific content of styrene-acrylic emulsion, silicon The organic-inorganic bonding system composed of potassium acid and silica sol, the inorganic silicate has good permeability, reacts with the concrete wall, and can penetrate into the wall substrate, so the bonding force is strong, and the styrene-acrylic emulsion improves the coating to powder The encapsulation property of the material, potassium silicate and silica sol synergistically improve the cohesion and crack resistance of the coating film. The paint has good stability, the obtained paint film has a weak gloss, and has a good and realistic imitation effect of fair-faced concrete; and the paint film has strong bonding force with the substrate, is not easy to peel off, and has good yellowing resistance.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be described more fully below. The present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the present disclosure is provided.

The weight of the relevant components mentioned in the description of the embodiment of the present invention can not only refer to the specific content of each component, but also can represent the proportional relationship between the weights of the components. It is within the scope disclosed in the description of the embodiments of the present invention that the content of the ingredients is scaled up or down. Specifically, the weight described in the description of the embodiment of the present invention may be a known weight unit in the chemical field, such as μg, mg, g, and kg.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

An embodiment of the present invention provides a kind of inorganic silicate imitating fair-faced concrete coating, according to mass percentage, comprises the following components:

Wherein, potassium silicate is potassium silicate modified by silane, and the modulus of potassium silicate is 3.5-4.0; the silica sol is stabilized; and the pH of the coating is 9-10.

Potassium silicate has good water resistance, is not easy to cause salting out, and has low cost, and is especially suitable for use in wall coatings. Silane-modified potassium silicate is to connect the silicon atoms in potassium silicate with organic groups, appropriately reducing the number of active functional groups of potassium silicate, thereby reducing the reactivity of potassium silicate and making it less prone to dehydration, condensation and self-polymerization. Reaction, when used in coatings, the viscosity is stable, it is not easy to gel, and it has good compatibility with organic emulsions, and it is not easy to produce flocculation particles. In addition to producing adhesive force, silane-modified potassium silicate can also penetrate into the cement substrate through capillary action and react with Ca(OH) ₂ in the cement substrate to generate CaSiO ₃ with adhesive properties. Gel, potassium silicate polycondensation reaction forms a -Si-O-Si-reticular skeleton gel structure with a chemical composition of silica, so it has a strong adhesion and sealing effect on the substrate, and the coating film has Good breathability, porous, matte and other advantages.

The modulus of potassium silicate adopted by the inorganic silicate imitation fair-faced concrete paint of the present invention is high, which is between 3.5 and 4.0. The low modulus potassium silicate solution has low silicate polymerization degree and small molecular weight. Under the same solid content, the lower the viscosity, the higher the reactivity, the stronger the cohesion and the better stability, but the curing speed is slower and the water resistance is poor. . At the same time, due to the high content of alkali metal ions and strong alkalinity, the phenomenon of salting out and whitening is more likely to occur. In the potassium silicate solution with a modulus of 3.5-4.0, the silicate ion has a high degree of polymerization, high molecular weight, fast curing speed, good water resistance, low alkalinity, less salting out and whitening, and the chemical stability of the coating film. Sex is better. However, due to the high viscosity, it is difficult to form a solution with high solid content, the reactivity is low, it is easy to crack and lose powder, and the stability of the coating is slightly poor. In the embodiment of the present invention, the potassium silicate adopts K100 potassium silicate from Shanghai Aorun.

The stabilized silica sol has organic groups attached to some active silanol groups, which reduces the reactivity of the silica sol. Adding silica sol to the potassium silicate solution can improve the problem of easy cracking and powder removal of high modulus potassium silicate, and improve the strength and crack resistance of the coating film. In the embodiment of the present invention, the silica sol adopts S308 of Shanghai Aorun.

Styrene-acrylic emulsion is an organic resin emulsion with good alkali resistance and low water absorption, and better compatibility with silicate in alkaline conditions.

Silicone hydrophobizing agent is a water-based, solvent-free silicone-modified organic emulsion. The silicone resin-modified polysiloxane solution is a waterproof additive for the manufacture of water-based exterior wall coatings and water-based primers. It can enhance the waterproofness and water resistance of the coating, maintain good air permeability, and improve the construction performance of water-based coatings. Plays an anti-caking effect.

The color paste can adjust the color tone of the paint, which is closer to the fair-faced concrete, and the imitation effect is better.

The inorganic silicate imitation clear-water concrete coating of the present invention comprises styrene-acrylic emulsion, potassium silicate, silica sol, titanium dioxide, filler, auxiliary agent, organosilicon hydrophobic agent, toning paste and water, styrene-acrylic emulsion with specific content, The organic-inorganic bonding system composed of potassium silicate and silica sol, inorganic silicate has good permeability, reacts with the concrete wall, can penetrate into the wall substrate and thus has strong binding force, and the styrene-acrylic emulsion improves the coating resistance. The encapsulation of powder, potassium silicate and silica sol synergistically improve the cohesion and crack resistance of the coating film. The paint has good stability, the obtained paint film has a weak gloss, and has a good and realistic imitation effect of fair-faced concrete; and the paint film has strong bonding force with the substrate, is not easy to peel off, and has good yellowing resistance.

In some of the embodiments, the content of potassium silicate is 5% to 10% in terms of mass percentage.

In some of the embodiments, the content of the silica sol is 15% to 20% in terms of mass percentage.

In some of the embodiments, in terms of mass percentage, the content of the styrene-acrylic emulsion is 6%; the content of potassium silicate is 5%; and the content of the silica sol is 15%. Under this composition, the inorganic silicate imitation fair-faced concrete coating has good compatibility of the colorant, good overall dispersion of the coating, and the coating film is not easy to crack, and has good crack resistance and stain resistance.

In some of these embodiments, the minimum film-forming temperature of the styrene-acrylic emulsion is not higher than 5°C. The styrene-acrylic emulsion at this film-forming temperature can form a film under various weather conditions, which is helpful for the overall film-forming of the coating, so there is no need to add additional film-forming aids.

In some of these embodiments, the titanium dioxide is of the rutile type. The rutile type titanium dioxide has good stability. Further, the rutile titanium dioxide is modified by silica, alumina and organically. The modified rutile titanium dioxide has better dispersibility and stability in water-based systems, and good weather resistance.

In some embodiments, the filler is selected from at least one of heavy calcium and quartz powder.

In some of the embodiments, the tinting paste is selected from at least one of iron black paste, carbon black paste and iron yellow paste. Preferably, the toning paste is a mixture of iron black paste and iron yellow paste.

In some of these embodiments, the inorganic silicate imitation fair-faced concrete coating comprises the following components in terms of mass percentage:

The coating of the above composition not only has smooth construction, good scrub resistance and stain resistance, but also has a good effect of imitating fair-faced concrete.

In some of these embodiments, the adjuvant includes the following components according to the mass percentage of the inorganic silicate imitation fair-faced concrete coating:

In some of these embodiments, the antifoaming agent is a mineral oil-based antifoaming agent.

In some of these embodiments, the dispersant is a polyacrylate dispersant.

In some embodiments, the wetting agent is an alkyl polyoxyethylene ether type wetting agent.

In some embodiments, the thickener is a cellulose thickener.

In some of the embodiments, the adjuvant further includes 0.5% to 1% of the film-forming adjuvant in terms of mass percentage. Further, the film-forming aid adopts dodecyl ester.

In some of these embodiments, the antifreeze is propylene glycol.

Another embodiment of the present invention also provides a preparation method of an inorganic silicate imitating fair-faced concrete coating, comprising the following steps S1-S6.

Step S1: Take each component of the above-mentioned inorganic silicate imitation fair-faced concrete coating for subsequent use.

Step S2: Stir and mix an appropriate amount of water and additives to form a colloidal substance.

Step S3: adding titanium dioxide and filler to the colloidal substance, and grinding.

Step S4: Continue to add the styrene-acrylic emulsion, and mix well.

Step S5: continue to sequentially add potassium silicate, silica sol, silicone hydrophobic agent and remaining water, and mix well.

Step S6: Continue adding toning color paste to obtain an inorganic silicate imitation fair-faced concrete paint.

The preparation method of the above inorganic silicate imitation clear-water concrete coating has simple preparation process, and the obtained coating has good dispersibility and stability. The formed paint film is firmly combined, not easy to be aged and peeled off, and the gloss is weak, showing a concrete tone, and the effect of imitating fair-faced concrete is good.

In some of the embodiments, the stirring speed in step S2 is 300 rpm to 500 rpm.

In some of the embodiments, the rotational speed of grinding in step S3 is 2000 rpm to 3000 rpm, and the grinding time is 20 min to 25 min.

In some of the embodiments, in step S4, mixing is performed at a rotational speed of 800 rpm to 1200 rpm.

In some of the embodiments, in step S5, mixing is performed at a rotational speed of 800 rpm to 1200 rpm.

Another embodiment of the present invention also provides the application of the above-mentioned inorganic silicate imitating fair-faced concrete coating in imitating fair-faced concrete.

In some of the embodiments, the above inorganic silicate imitating fair-faced concrete paint can be used as the main paint and the pattern paint of imitating fair-faced concrete.

In order to make the objects, technical solutions and advantages of the present invention more concise and clear, the present invention is described with the following specific embodiments, but the present invention is by no means limited to these embodiments. The embodiments described below are only preferred embodiments of the present invention, which can be used to describe the present invention, and should not be construed as limiting the scope of the present invention. It should be pointed out that any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

The content of the present invention will be further described below in conjunction with the examples. The following are specific examples.

In the following examples, the imitation of fair-faced concrete is implemented as follows: coating a transparent penetrating primer, a main coating, a patterning coating and a reinforcing finish coating on the cement substrate in sequence. The main paint provides the main color of the imitation of fair-faced concrete, and the patina paint modifies the texture of the imitation of the fair-faced concrete by rubbing and rubbing.

In the following examples, the proportion of 100% transparent penetrating primer is: 837 styrene-acrylic emulsion 10%, mineral oil defoamer 0.1%, K100 potassium silicate 28% and the balance of water.

The ratio of reinforcement finish coating is: 837 styrene-acrylic emulsion 10%, mineral oil defoamer 0.1%, K100 potassium silicate 38% and water balance.

The ratio of the pattern paint is exactly the same as that of the main paint.

Refer to Table 1 and Table 2 for the main paint ratio (wt %) of Examples and Comparative Examples.

Table 1

Table 2

The coatings of Examples 1-5 and Comparative Examples 1-8 were prepared according to the following methods:

Add water to the dispersing tank, then add dispersant, wetting agent, defoamer, film-forming aid, antifreeze, thickener, antifungal agent and pH adjuster, and stir and mix at 400 rpm to form a jelly-like substance .

Add titanium dioxide and fillers into the dispersing cylinder, beat and grind at 2500 rpm for 25 minutes to a fineness of 50 μm.

Add the styrene-acrylic emulsion to the dispersion tank, and mix at 1000 rpm.

Add potassium silicate solution, silica sol, organosilicon hydrophobic agent and remaining water in sequence to the dispersing tank, mix uniformly at 1000 rpm, and then add carbon black slurry and iron yellow slurry.

According to the standard "JG/T26-2002" of inorganic coatings for exterior walls, the imitation fair-faced concretes prepared in Examples 1 to 5 were respectively tested, and the results are shown in Table 3.

table 3

The main coatings provided in Examples 1 to 5 and Comparative Examples 1 to 8 were used to test the performance according to JG/T26-2002, focusing on the test of scrub resistance and stain resistance, as well as construction and appearance indicators. The test results are shown in Table 4.

Table 4

Referring to Table 1 and Table 2, it can be shown from the above test results that the inorganic silicate imitation fair-faced concrete coatings prepared in Examples 1 to 3 have basically no abnormality in workability, the contrast ratio is greater than 0.95, the scrubbing resistance is greater than 6000 times, and there is no abnormality in low temperature storage. , The stain resistance is less than 20, and the artificial aging resistance is 1000h.

Compared with Example 1, the potassium silicate content in the inorganic silicate imitation fair-faced concrete coating of Example 4 increases, other properties have no significant change, and the coating film has a good imitation of fair-faced concrete effect, but the stain resistance is poor. The content of silica sol in the coating of Example 5 increased, and other properties did not change significantly. The coating film had a good effect of imitating fair-faced concrete, but in the artificial aging resistance test of 1000h, chalking≤2 grades, discoloration≤2 grades, that is, slight chalking , slightly discolored.

Compared with Example 1, the coatings of Comparative Examples 1-8 adjusted the contents of styrene-acrylic emulsion, potassium silicate and silica sol. The coatings of Comparative Examples 1 to 8 are deficient in film-forming properties, adhesion to powders or stain resistance, and in particular, they cannot achieve a good imitation of fair-faced concrete in appearance.

Specifically, in Comparative Example 1, the styrene-acrylic emulsion was not added, and the paint film obtained was less resistant to washing, and the surface of the paint film was powdered. In contrast, 12% styrene-acrylic emulsion was added in Comparative Example 6. Although the workability, scrub resistance and stain resistance were not significantly affected, the coating film had a strong luster and could not achieve the effect of imitating fair-faced concrete.

Comparative Example 2 does not add potassium silicate, and the paint film obtained has a low washing resistance and a slight cracking of the paint film. On the other hand, the comparative example 7 added 25% potassium silicate, although the workability, scrub resistance and appearance were not obviously bad, but the stain resistance was poor.

In Comparative Example 3, without adding silica sol, the surface of the coating film prepared was powdery, uneven in color, and flowered, and the imitation effect was poor. On the other hand, the coating of Example 8 to which 35% of silica sol was added had poor film-forming properties, the paint film was slightly cracked, and the stain resistance was poor.

Comparative examples 4 to 5 only use potassium silicate or silica sol single bonding system, and the scrub resistance, stain resistance and appearance performance of the coating film are not good to varying degrees.

This fully shows that inorganic silicate imitation fair-faced concrete coatings need to combine the three, through the synergistic effect of the three, improve the cohesion and strength of the coating film, improve scrub resistance, reduce internal stress, and reduce the risk of cracking. Complementary effect with silica sol to improve stain resistance.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (8)

1. The inorganic silicate as-cast finish concrete imitation coating is characterized by comprising the following components in percentage by mass:

5% -8% of styrene-acrylic emulsion;

5% -10% of potassium silicate;

15% -20% of silica sol;

15% -18% of titanium dioxide;

15% -20% of a filler;

1.6% -4.5% of an auxiliary agent;

0.5% -1% of organic silicon hydrophobing agent;

0.2% -0.4% of color-mixing paste; and

the balance of water;

wherein the potassium silicate is silane-modified potassium silicate, and the modulus of the potassium silicate is 3.5-4.0; stabilizing the silica sol; the pH value of the coating is 9-10;

the silica sol is subjected to stabilizing treatment, namely: and organic groups are connected on part of active silanol groups in the silica sol.

2. The inorganic silicate as clear water imitation concrete coating as claimed in claim 1, wherein the content of the styrene-acrylic emulsion is 6% by mass; the content of the potassium silicate is 5%; the content of the silica sol was 15%.

3. The inorganic silicate as dry-cast-imitation concrete coating of claim 1, wherein the styrene-acrylic emulsion has a minimum film-forming temperature of not higher than 5 ℃.

4. The inorganic silicate as clear water imitation concrete coating as claimed in any one of claims 1 to 3, wherein the titanium dioxide is rutile type.

5. The inorganic silicate as clear water imitation concrete coating of any one of claims 1 to 3, wherein the filler is at least one selected from heavy calcium carbonate and quartz powder.

6. The inorganic silicate as clear water imitation concrete coating as claimed in any one of claims 1 to 3, wherein the assistant comprises the following components in percentage by mass:

0.5% -1% of an antifreezing agent;

0.3% -0.5% of a dispersant;

0.1% -0.2% of wetting agent;

0.1% -0.2% of defoaming agent;

0.3% -0.5% of thickening agent; and

0.2-0.3% of mildew preventive.

7. A preparation method of an inorganic silicate as-cast finish concrete coating is characterized by comprising the following steps:

taking the components of the coating of any one of claims 1 to 6 for later use;

stirring and mixing a proper amount of water and the auxiliary agent to form a colloidal substance;

adding the titanium dioxide and the filler into the colloidal substance, and grinding;

adding the styrene-acrylic emulsion and uniformly mixing;

sequentially adding the potassium silicate, the silica sol, the organic silicon hydrophobic agent and the rest water, and uniformly mixing;

and adding the color paste to obtain the coating.

8. Use of the inorganic silicate as defined in any one of claims 1 to 6 as a coating for imitating fair-faced concrete.