阅读说明：本技术 粉体组合物 (Powder composition ) 是由 段瑜芳 张志亮 孙大庆 金常青 于 2019-06-10 设计创作，主要内容包括：本公开涉及一种粉体组合物,包括30-60％的可再分散乳胶粉、5-30％的水泥、20-70％的填料和0-8％的添加剂。该粉体组合物用于瓷质砖铺贴时具有优良的粘结性能特别是浸水后的粘结性能。(The disclosure relates to a powder composition comprising 30-60% of redispersible latex powder, 5-30% of cement, 20-70% of filler and 0-8% of additive. The powder composition has excellent adhesive property when being used for paving ceramic tiles, in particular to the adhesive property after being soaked in water.)

1. The powder composition is characterized by comprising the following components:

30 to 60 percent of re-dispersible latex powder,

5 to 30 percent of cement,

20-70% of filler and

0-8% of additive;

the percentages are based on the total mass of the composition.

2. A powder composition according to claim 1 wherein the polymer as the main component of the redispersible latex powder is copolymerized from monomers comprising vinyl esters and ethylene.

3. The powder composition of claim 2, wherein the redispersible latex powder has a Tg in the range of-10 ℃ to 20 ℃.

4. The powder composition of any one of claims 1-3, wherein the dispersible latex powder is present in an amount of 30-50%.

5. The powder composition according to any one of claims 1 to 4, wherein the content of the cement is 5% or more and less than 15%.

6. The powder composition according to any one of claims 1 to 4, wherein the content of the cement is 15% or more and 25% or less.

7. The powder composition according to any one of claims 1 to 6, wherein the filler has a particle size of 0.38mm or less.

8. The powder composition according to claim 7, wherein 60% or more of the filler has a particle size of 0.15mm or less, and the percentage is the percentage based on the total mass of the filler.

9. A powder composition according to any one of claims 1 to 8, wherein the filler comprises quartz sand or quartz powder and calcium carbonate.

10. Use of a powder composition according to any one of claims 1 to 9 for tile applications.

11. The use according to claim 10, wherein the powder composition is used in combination with cement mortar or tile glue for tile application.

12. The use according to claim 10 or 11, wherein the powder composition and water are mixed in a ratio of 1 (0.8-1.2) and then applied to the back of the tile.

13. The use according to claim 12, wherein the powder composition and water mixture is applied at the interface between tile and cement mortar, and at the interface between cement mortar and wall or ground, respectively.

Technical Field

The present disclosure relates to a powder composition and its use in tile tiling.

Background

The porcelain tile (commonly called vitrified tile) is a ceramic tile with smooth surface and water absorption lower than 0.5 percent. The low water absorption makes it difficult to firmly bond the porcelain tile to the wall or floor by means of cement mortar only, because the cement mortar is allowed to penetrate through the pores on the back of the porcelain tile to achieve the bonding purpose. In order to solve the problem, at present, when the porcelain tiles are pasted, polymer modified tile glue is generally used for pasting. In recent years, the ceramic tile back glue and cement mortar are matched for pasting.

The ceramic tile adhesive is a ceramic tile adhesive for short, generally refers to a product meeting the requirements of an industry standard JC/T547-containing 2017 ceramic tile adhesive, and is mainly based on cement. The main components of the mortar are cement, sand aggregate and filler, and a small amount of water retention agent, polymer and other additives can be contained. For example, the ceramic tile adhesive disclosed in CN106673553A comprises 15-25 parts of cement, 30-42 parts of river sand, 20-35 parts of ceramic tile polishing waste residue, 1-2 parts of redispersible rubber powder and 0.1-0.5 part of water-retaining agent. Compared with cement mortar, the tile glue can be constructed by a thin layer method, so that the paving thickness is greatly reduced, but because the flatness of the current base wall body cannot meet the requirement, the thick layer paving by a back coating method is mainly used in practical application, and if the tile glue is completely used for leveling and paving, the filling shortage with high cost exists. If cement is used as a leveling layer on the wall surface or the ground in advance when the porcelain tiles are pasted, a procedure and waiting time are increased, which is unacceptable in practical application.

The tile back glue is a product which is used for increasing unqualified bonding materials such as tiles, cement mortar and the like on the back of tiles as the name suggests and only appears in recent years. The ceramic tile back glue has various types, namely a single-component back glue prepared on the basis of polymer emulsion, and a double-component back glue used by matching cement mortar powder with polymer emulsion liquid, wherein the double-component back glue can comprise a small amount of defoaming agent, water and other auxiliary agents besides high polymer materials and inorganic silicate. The single-component tile back glue disclosed in CN105969308A comprises 20-40% of micro-nano acrylic emulsion, 20-40% of modified pressure-sensitive adhesive emulsion, 4-10% of butylbenzene emulsion, 0.1-0.2% of thickening agent, 0.2-0.5% of film-forming assistant, 0.1-0.3% of defoaming agent, 0.1-0.5% of preservative, 0.1-0.5% of mildew preventive and the balance of deionized water. In the two-component tile back glue composition disclosed in CN 105418031B, the powder components comprise 39-55% of cement, 39-55% of fine sand, 1-5% of latex powder, 1-5% of auxiliary agent, 0.1-1% of water-retaining agent and 1-2% of retarder; the liquid component comprises 40-70% of acrylic emulsion, 0.1-0.2% of defoaming agent, 28.4-59.2% of water, 0.2-0.4% of film-forming assistant and 0.5-1% of regulator.

Compared with tile glue, the tile gum is matched with cement mortar to be paved so as to reduce cost, and therefore a certain market is obtained, but the tile gum products are various in types, uneven in quality, inappropriate in use and extremely easy to form quality and potential safety hazards without practical inspection. Moreover, the construction time of the back glue of the ceramic tiles is long, and the ceramic tiles can be stuck by using the cement mortar after the back glue is dried after more than 2 hours. Also, storage and transportation of liquid adhesives are often limited by temperature, particularly in areas below 0 ℃. Therefore, there is still a need to develop a product with good adhesive property, short construction time and convenient transportation to meet the market demand.

CN103466996A discloses a powdery mosaic back adhesive, which comprises 600 parts of redispersible latex powder of 100-one materials, 600 parts of quartz sand of 200-one materials, 10-200 parts of sodium chloride, 5-100 parts of bentonite, 1-10 parts of a water reducing agent, 1-10 parts of cellulose ether, 0.5-10 parts of a defoaming agent, 1-5 parts of lignocellulose and 1-5 parts of a mildew preventive. When in use, the gum is mixed with water according to the proportion of 1 (0.2-0.3), and the mixture is spread on the wall surface or the ground surface and kneaded to obtain the mosaic. Compared with a liquid gum product, the powder gum has the advantages of easy transportation and storage, but the product is only suitable for mosaic, cannot be used for large-size ceramic tiles, has poor bonding performance, particularly the bonding performance after soaking, and has higher use cost.

Disclosure of Invention

The powder composition provided by the present disclosure can at least solve one or more of the above-mentioned technical problems, has advantages of transportation and storage, has excellent adhesive properties, particularly after soaking, when used for paving porcelain tiles, has short construction time, and also has certain cost advantages compared to the existing tile adhesive direct paving and tile back adhesive matched cement mortar paving.

In the present disclosure, the term "cement mortar" refers to ordinary cement mortar which is not modified with redispersible latex powder, and is prepared from cement, fine aggregate and water, and lime, admixture or admixture added as needed. Wherein the fine aggregate is aggregate with particle size of below 4.75mm, and comprises natural sand such as river sand, sea sand, mountain sand, and artificial sand. The admixture is divided into an active admixture and an inactive admixture, the active mineral admixture is not hardened or has a very slow hardening speed, but can be combined with calcium hydroxide separated out by cement hydration to generate cementitious hydrate, such as fly ash, granulated blast furnace slag powder, zeolite powder, silica fume and the like; the non-reactive mineral admixtures are substantially non-reactive with the cementitious components, such as limestone, ground quartz sand, and the like. The additive is an additive capable of improving the performance of cement mortar, and comprises a thickening agent, a water reducing agent, an early strength agent, a waterproof agent, a defoaming agent, an antifreeze agent and the like, wherein the additive does not comprise redispersible latex powder.

In the present disclosure, the term "ceramic tile" refers to a tile having a water absorption of 0.5% or less, particularly a tile having a water absorption of 0.5% or less and having an alkali-resistant property.

In the present disclosure, "free" or "excluding" means that the content of a certain ingredient in the material is less than 0.1 wt%, for example less than 0.05 wt%, or even less than 0.01 wt%.

A first aspect of the present disclosure provides a powder composition comprising the following components:

30 to 60 percent of re-dispersible latex powder,

5 to 30 percent of cement,

20 to 70% of filler, and

0-8% of additive;

the percentages are based on the total mass of the composition.

Redispersible latex powder

The redispersible emulsion powder is polymer powder obtained by spray drying the polymer emulsion, can be redispersed in water when being mixed with water, is reduced into an emulsion state, and has the performance equivalent to or similar to that of the original emulsion. The redispersible latex powders are mainly composed of polymers and also contain small amounts of protective colloids, such as polyvinyl alcohol, and optionally additives, such as plasticizers, film-forming aids, defoamers, and optionally antiblocking agents, such as fine mineral fillers. The polymer content is generally around 80-90%, said percentages being based on the total mass of the dispersible latex powder. In one embodiment, the redispersible latex powder comprises as main components a polymer and a protective colloid, and a fine mineral filler, and is free of plasticizers and film-forming aids.

Suitable polymers are polymerized from monomers comprising one or more of the following: vinyl esters of straight-chain or branched alkyl carboxylic acids having 1 to 15 carbon atoms, such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl laurate; olefins, such as ethylene, propylene, 1, 3-butadiene, isoprene; methacrylic esters or acrylic esters of alcohols having 1 to 10 carbon atoms, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate; vinyl aromatic hydrocarbons such as styrene, methyl styrene, vinyl toluene; vinyl halides, such as vinyl chloride.

The polymer is preferably copolymerized from monomers comprising vinyl esters and ethylene. In one embodiment, the polymer is obtained by copolymerizing vinyl ester and ethylene monomers, more specifically vinyl acetate and ethylene monomers, wherein the ethylene monomer is a hydrophobic monomer, and the higher the content of the ethylene monomer, the more favorable the powder composition is for improving the adhesion performance after soaking when the powder composition is used for tile paving. In another embodiment, the polymer is copolymerized from vinyl ester, ethylene and a third monomer, more specifically, vinyl acetate, ethylene and a third monomer, and in order to obtain more excellent adhesion after immersion in water, the third comonomer preferably includes a hydrophobic group-containing monomer such as vinyl butyrate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl laurate, vinyl chloride, and the like.

If desired, the polymers may also contain from 0.1 to 10% by weight, based on the total weight of the polymer, of functional comonomers, such as ethylenically unsaturated carboxylic acids and derivatives thereof, such as fumaric acid, maleic anhydride, acrylamide, acrylonitrile; pre-or post-crosslinking comonomers, such as divinyl adipate, diallyl maleate, allyl methacrylate, triallyl cyanurate, acrylamidoglycolic acid (AGA), methyl methacrylamidoglycolate (MAGME), N-methylolacrylamide (NMA), N-methylolmethacrylamide (NMMA), N-methylolallyl carbamate, the isobutoxy ether or ester of N-methylolacrylamide, the isobutoxy ether or ester of N-methylolmethacrylamide, the isobutoxy ether or ester of N-methylolallyl carbamate; epoxy functional comonomers such as glycidyl methacrylate (GAM), glycidyl acrylate; silicon-functional comonomers, such as vinyltrialkoxysilane, vinylmethyldialkoxysilane. Preferably, the polymer does not contain other functional comonomers.

The glass transition temperature (Tg) of the redispersible latex powder is not particularly limited by the present disclosure, with a preferred Tg in the range of-10 deg.C to 20 deg.C, e.g., -10 deg.C to 15 deg.C, -10 deg.C to 10 deg.C. In one embodiment of the present disclosure, the redispersible latex powder is a rubber powder having a Tg of-10 to 10 ℃. In another embodiment, the redispersible latex powder comprises a latex powder having a Tg of from-10 ℃ to 10 ℃ and a latex powder having a Tg of from 0 ℃ to 20 ℃. In the present disclosure, Tg is determined by Differential Scanning Calorimeter (DSC) measurement of a scan rate of 10 deg.C/min in a temperature range of-70 deg.C to 100 deg.C, unless otherwise specified. The Tg values of the present disclosure are temperature values in degrees celsius that correspond to the median value of the slope change in the heat flow rate-temperature curve, more specifically the temperature value of the intersection of the equidistant middle line of the two parallel baselines before and after glass transition and the heat flow rate-temperature curve.

The amount of the redispersible latex powder is 30 to 60 percent, preferably 30 to 50 percent. The using amount of the redispersible latex powder is lower than the range, and the bonding property of the obtained powder composition after soaking when the powder composition is used for paving and pasting ceramic tiles is not ideal; above this range, the cost of the powder composition is high, and the application thereof is limited.

Cement

The cement is ordinary portland cement conventionally used in the art, and may be, for example, 42.5 grade cement, 42.5R grade cement, 52.5 grade cement.

The amount of cement used is 5-30%, for example 5%, 10%, 15%, 20%, 25%, 30%. The cement content is lower than the range, and the soaking binding property of the obtained powder composition is not ideal when the powder composition is used for paving ceramic tiles; above this range, the pot life of the powder composition after mixing with water is short, which is not favorable for construction. In one embodiment of the present disclosure, the cement content is 5% or more and 15% or less, and the powder composition has good workability after mixing with water and has improved water-impregnated adhesion properties when used for tile tiling. In another embodiment, the cement content is greater than or equal to 15% and less than or equal to 25%, more specifically greater than or equal to 20% and less than or equal to 25%, and the powder composition has excellent water-soaking binding performance and better workability when used for tile paving.

Filler material

Non-limiting examples of such fillers include quartz sand, quartz powder, calcium carbonate, dolomite, aluminum silicate, talc, mica, or light fillers such as pumice, foam glass, aerated concrete, perlite, vermiculite or other fillers based on natural or synthetic fibers, and mixtures of the above fillers. "mixtures" here comprise mixtures of fillers of different substance classes and mixtures of fillers of the same substance class with different particle sizes.

Since the particle size of the filler is related to the settling property of the slurry obtained by mixing the powder composition with water, the particle size of the filler is preferably 0.38mm or less, more preferably 0.15mm or less, in order to obtain a good anti-settling property. In a preferred embodiment, 60% or more of the filler has a particle size of 0.15mm or less, and the percentage is the percentage of the total mass of the filler. In another preferred embodiment, more than 60% of the filler has a particle size of less than 0.075mm, the remainder of the filler having a particle size in the range of 0.075 to 0.15mm, the percentages being percentages by mass of the total filler.

In a more specific embodiment, the filler comprises quartz sand/quartz powder having a particle size of 0.075 to 0.27mm and calcium carbonate having a particle size of less than 0.075 mm.

The fillers may be used in amounts of 20%, 30%, 40%, 50%, 60%, 70%, preferably 30-60%.

Additive agent

The powder composition of the present disclosure may further include an additive as long as it does not impair achievement of the object of the present invention. The additive can be a thickening agent, a film forming additive, a water reducing agent, a defoaming agent, a mildew preventive, a preservative and the like.

In one embodiment, the additive is a thickener; non-limiting examples of thickeners include unmodified/modified cellulose ethers such as methyl hydroxypropyl cellulose ether, methyl hydroxyethyl cellulose ether; the thickener is preferably used in an amount of 0.05 to 2%, more preferably 0.05 to 1%, and particularly preferably 0.1 to 0.5%.

A second aspect of the present disclosure provides the use of a powder composition according to the first aspect of the present disclosure in tile tiling, in particular in conjunction with cement mortar or tile glue, especially cement mortar, for tile tiling. The specific application method is as follows:

1) mixing the powder composition and water according to the proportion of 1 (0.8-1.2), wherein the mixing mode has no special requirement as long as the powder composition and the water can be uniformly mixed;

2) applying the obtained slurry to the back of the ceramic tile, and smearing cement mortar after the slurry is dried or directly smearing the cement mortar without waiting for the slurry to be dried so as to shorten the construction time;

3) the resulting slurry is applied to a wall or floor, typically a wall, and the tile, coated with the slurry and cement mortar, is then applied thereto.

When the powder composition is used for paving ceramic tiles, the adhesive force of the ceramic tiles and cement mortar can be enhanced, particularly the adhesive property after soaking, and the cost is greatly reduced (about 0.3-0.4 RMB/m)²The paving area) is obviously lower than the back adhesive cost (about 0.7-0.8 RMB/m) of the porcelain tiles on the market²The area of the tile).

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Pull out bond strength test

Mixing the powder composition with water according to the proportion shown in the table 1, uniformly stirring, applying the obtained slurry to the back of the porcelain tile and the surface of the concrete substrate by using a roller respectively, and airing for 24 hours for later use; a strong ceramic tile adhesive (5 generation quick-drying type) (namely a back adhesive defined in the disclosure, hereinafter abbreviated as LB) produced by Qingyuan Shanghai building materials science and technology Limited company is directly applied to the back of a ceramic tile and the surface of a concrete substrate by a roller respectively and is aired for 24 hours for standby.

And then preparing cement mortar according to section 7.4.1 of standard JC/T547-2017 of ceramic wall and floor tile adhesive, smearing the cement mortar on the surface of the ceramic tile coated with the slurry or LB by using a spatula, then paving the cement mortar on the surface of the concrete base material coated with the slurry or LB, and controlling the thickness of the cement mortar to be about 5mm by using a mould. After molding, the molded product was cured under the following curing conditions.

Standard maintenance: maintaining for 14 days under the standard conditions of the temperature of 23 +/-2 ℃ and the relative humidity of 50 +/-5%.

Soaking and maintaining: the mixture was cured for 7 days under standard conditions and then cured for 7 days in water at 20. + -. 2 ℃.

And (3) before the maintenance is finished, adhering the drawing head to the porcelain tile by using an epoxy adhesive 24 hours in advance, continuously placing the porcelain tile to the end of the age under corresponding conditions, and measuring the drawing adhesive strength.

The starting materials in table 1 are all commercially available with the following specific information:

redispersible latex powder 1, which is a latex powder based on vinyl acetate and ethylene, containing fine mineral antiblocking agents but no plasticizers and film-forming auxiliaries, -10 ℃ < Tg <10 ℃, supplied by wacker chemical company.

Redispersible latex powder 2, which is a latex powder based on vinyl acetate and ethylene and a third comonomer, contains fine mineral antiblocking agents but no plasticizers and film-forming auxiliaries, 0 ℃ < Tg <20 ℃, supplied by wacker chemical company.

Methyl hydroxypropyl cellulose ether, viscosity 10,000 and 100,000 mPa.s.

In Table 1, the amounts are expressed in parts by weight.

Powder compositions of examples and comparative examples were prepared according to table 1, and then the powder compositions were mixed with water in the following ratio, and after stirring uniformly, the resulting slurry was applied to the back of a porcelain tile, and the pull-tack strength after curing under different conditions was measured, using LB as a reference.

TABLE 1

TABLE 2

It can be seen that the powder compositions of examples 1-5 have significantly improved pull-out tack strengths after different curing conditions compared to the commercial liquid floor tile backsize. Comparing examples 1-2 with comparative examples 1-2, it can be seen that the amount of redispersible latex powder is less than 30%, the pullout adhesion strength after the water immersion curing of the obtained paste is significantly reduced, and the pullout adhesion strength after the standard curing is also significantly reduced. As is clear from comparison of examples 3 to 5 with comparative example 3, the cement content was less than 5%, and the pull-out adhesion strength after the water immersion curing of the resulting slurry was significantly reduced. The formula of comparative example 4 refers to the formula of the tile adhesive, and the pull-out adhesive strength of the obtained slurry after curing under different conditions is obviously reduced.