KR20170076971A - Thickener for tile cement and tile cement mortar comprising the same - Google Patents

Abstract

The present invention provides a thickener for tile cement and a tile cement mortar containing the same, which comprises cellulose ether and cyclodextrin.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a thickener for tile cement and a tile cement mortar containing the same.

More particularly, the present invention relates to a thickener for tile cement comprising cellulose ether and cyclodextrin, and a tile-cement mortar containing the thickener for tile cement.

Tiles have been widely used as architectural finishes for a long time due to their beautiful appearance, ease of construction, hygiene, and ease of maintenance and maintenance of buildings.

Tile adhesives for attaching tiles to walls or floors are classified into cement mortar adhesives, resin adhesives and emulsion adhesives depending on the type of main binder. Among them, cement mortar Adhesives are the most widely used, and such cement mortar adhesives are commonly referred to as tile cement mortars.

The main properties required for tile cement mortar are sag resistance, open time and adhesion strength. The deflection resistance and adhesive strength have become important as large-size tiles have recently been introduced as the finishing materials for buildings. Especially, when the open time indicating the time available for tile application after the application of mortar is not secured enough, Therefore, securing the open time in the construction environment where the proportion of labor cost is higher than the material cost is very important because it is directly related to the reduction of the labor cost due to shortening of the air.

Methods to increase this open time include reducing the amount of cement, using coarse grain aggregates, and using asbestos. However, the method of reducing the amount of cement causes deterioration of the adhesive strength, and the method of using the coarse aggregate is not compatible with the modern construction method which performs very thin quality, and the method of using asbestos It is harmful and its use is prohibited.

To solve these problems, cellulose ethers based on natural materials are widely used as building thickeners. Cellulose ether has high viscosity and water retention, and these properties of cellulose ether strengthen the adhesion of tile cement mortar to the working surface during tile construction, and strengthen the sag resistance and prevent water evaporation, So that the cement can be tightly cured.

However, the cellulose ether may be transferred to the surface of the mortar by capillary action with a water-soluble polymer to form a polymer film, which may hinder open time. In other words, the mortar is applied to the wall surface, and the moisture inside the mortar moves to the surface along the capillary pore as time passes. At this time, cement ion, hydroxide calcium hydroxide, water-soluble polymers such as polyvinyl alcohol and cellulose ether, Integrated. In this case, although the inside of the mortar is still moist and has water, a film is formed in many cases. In particular, when a high viscosity cellulose ether is used, a strong film is often formed. Therefore, high viscosity cellulose ether is effective for maintenance of water retention to exhibit sufficient adhesive strength, but it may be a disadvantage in terms of open time.

Therefore, it is required to develop a new cellulose ether additive capable of improving the deflection resistance and adhesive strength of the tile cement mortar and at the same time, prolonging the open time.

One of the technical problems to be solved by the technical idea of the present invention is to provide a thickener for tile cement which contains cellulose ether and can prolong the open time of tile cement mortar and a tile cement mortar containing the same.

The thickener for tile cement according to an embodiment of the present invention may include cellulose ether and cyclodextrin.

For example, the cyclodextrin may be at least one selected from the group consisting of? -Cyclodextrin,? -Cyclodextrin,? -Cyclodextrin, and mixtures thereof.

For example, the content of the cyclodextrin may be 5 to 30% by weight based on the total weight of the tile cement thickener.

For example, the cellulose ether may be selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxyethyl cellulose, and mixtures thereof. Lt; RTI ID = 0.0 > and / or < / RTI >

For example, the methyl cellulose has a methyl substitution degree (DS) of 0.27 to 2.0, and the hydroxypropyl methyl cellulose has a degree of methyl substitution (DS) of 0.27 to 2.50 and a degree of hydroxypropyl group substitution (MS) of 0.02 to 1.1 (MS) of 0.03 to 1.3, and the hydroxyethyl cellulose has a degree of substitution (MS) of hydroxyethyl group of 0.3 Lt; / RTI >

For example, the viscosity of the cellulose ether aqueous solution having a concentration of 2% by weight may be 10 to 200,000 mPa · s as measured by a Brookfield viscometer at 20 ° C and 20 rpm.

The tile cement mortar according to one embodiment of the present invention may include the thickener for the tile cement, the cement, the aggregate, and the redispersible powder polymer (RDP).

For example, the content of the thickener for tile cement may be 0.1 to 1.0 part by weight based on 100 parts by weight of the total weight of the cement, the aggregate, and the re-fusing powder resin.

The tile cement mortar containing the thickener for tile cement according to an embodiment of the present invention has excellent sag resistance and adhesive strength, and has an effect of prolonging the open time.

Hereinafter, the thickener for tile cement and the tile cement mortar according to one embodiment of the present invention will be described in detail.

The thickener for tile cement according to an embodiment of the present invention may include cellulose ether and cyclodextrin.

Cyclodextrin or cycloamylose refers to compounds consisting of cyclic sugar molecules bound together. Cyclodextrins, which can be produced by enzymatic reaction with starch as a raw material, are used in food, medicine, chemical industry, agriculture and the like.

Cyclodextrins can be made up of five or more alpha -D-glucopyranoside units. Cyclodextrins consisting of five a-D-glucopyranoside units are not present in nature. Typical cyclodextrins contain 6 to 8 glucose monomers in the ring and include those containing 6 units as? -Cyclodextrin, those containing 7 units as? -Cyclodextrin, containing 8 units Is called? -Cyclodextrin. Cyclodextrins,? -Cyclodextrins and? -Cyclodextrins are shown in the following Formulas 1 to 3, respectively.

[Chemical Formula 1]

(2)

(3)

The open time of tile cement mortar is related to the rate of evaporation of moisture moving from mortar to air, the rate of movement of moisture moving from the bottom of mortar to the air through the mortar, and the surface affinity of polymer and inorganic material in mortar. The cyclodextrin used in the present invention acts on the surface of the mortar to interfere with the bonding of the inorganic substance and the cellulose ether by intervening in the pores of the surface film formed by the bond of the inorganic substance and the cellulose ether. Thereby inhibiting the skinning of the tile cement mortar and consequently increasing the open time and wetting capability of the mortar.

The cyclodextrin added to the thickener for tile cement according to an embodiment of the present invention may be at least one selected from the group consisting of? -Cyclodextrin,? -Cyclodextrin,? -Cyclodextrin, and mixtures thereof.

The content of the cyclodextrin may be 5 to 30% by weight based on the total weight of the thickener for tile cement. When the content of cyclodextrin is less than 5% by weight based on the total weight of the tile cement thickener, it is difficult to contribute to improvement of the open time of the tile cement mortar. When the content of cyclodextrin is more than 30% by weight with respect to the total weight of the tile cement thickener The water retention of the cellulose ether is deteriorated and sufficient hydration of the cement can not be ensured.

The cellulose ether added to the thickener for tile cement according to one embodiment of the present invention is selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxyethyl Hydroxyethyl cellulose, and a mixture thereof.

The methyl cellulose may have a methyl substitution degree (DS) of 0.27 to 2.0, and the hydroxypropyl methyl cellulose may have a methyl substitution degree (DS) of 0.27 to 2.50 and a hydroxypropyl group degree of substitution (MS) of 0.02 To 1.1. The hydroxyethylmethylcellulose may have a degree of methyl substitution (DS) of 0.27 to 2.40 and a degree of substitution (MS) of hydroxyethyl group of 0.03 to 1.3, and the hydroxyethyl cellulose may be substituted with a hydroxyethyl group The MS can be 0.3 to 5.0.

In the present specification, the degree of substitution (DS) means the average number of hydroxyl groups substituted with an alkyl group per anhydroglucose unit. Since there are at most 3 hydroxyl groups per anhydrous glucose unit, the theoretical maximum degree of substitution (DS) is 3 when substituted with a monofunctional substituent. However, since the polyfunctional or polymerizable substituent reacts not only with the hydrogen of the hydroxyl group contained in the anhydroglucose unit but also with itself, the degree of substitution (DS) is not limited to 3. Also, in this specification, the degree of molar substitution (MS) means the number of moles of multifunctional or polymeric substituents per anhydroglucose unit. There is no theoretical maximum value of this degree of substitution (MS).

When the substitution degree of the methyl group is high, the hydrophobicity is high, and when the degree of substitution of the hydroxypropyl group or the hydroxyethyl group is low, the hydrophobicity is high. Therefore, when cellulose ether having a degree of methyl group substitution exceeding the upper limit value or a degree of substitution of the hydroxypropyl group lower than the lower limit value is used, the water retention of the cellulose ether becomes insufficient and the workability of the extrusion molding cement mortar containing the cellulose ether may become poor.

The viscosity of the cellulose ether aqueous solution having a concentration of 2% by weight can be 10 to 200,000 mPa · s, preferably 2,000 to 120,000 mPa · s, as measured by a Brookfield viscometer at 20 ° C. and 20 rpm have. If the viscosity of the cellulose ether aqueous solution is less than 10 mPa.s, the thickening effect is not exhibited, and if the viscosity exceeds 200,000 mPa.s, the workability becomes very poor due to the high viscosity, which is not preferable.

The thickener for tile cement according to one embodiment of the present invention may further include an anti-caking agent. The anti-caking agent is a filler added to improve the water dispersibility of the cellulose ether in the tile cement mortar. The anti-caking agent may be at least one selected from the group consisting of calcium carbonate, magnesium carbonate, fumed silica, and precipitated silica.

The tile cement mortar according to one embodiment of the present invention may include a thickener for tile cement, cement, aggregate, and re-fired powder resin.

The content of the thickener for tile cement may be 0.1 to 1.0 part by weight based on 100 parts by weight of the total weight of cement, aggregate and re-fusing powder resin. If the content of the thickener for tile cement is less than 0.1 part by weight relative to the total amount of 100 parts by weight of the cement, aggregate and re-oiling type powder resin, the addition effect may be insufficient. If the amount is more than 1.0 part by weight, The adhesive strength can be reduced.

The cement may be hydraulic cement such as Portland cement, fly ash cement and aluminum containing cement, and color cement may be used. In addition, if desired, at least one selected from the group consisting of semi-gypsum, slaked lime, calcium carbonate and clay may be used in the tile cement mortar together with the cement. Examples of the aggregate include river sand, mountain sand, silica sand, lightweight aggregate (e.g., pearlite), and the like. In addition, an emulsion, a fibrous material and the like may be blended into the tile cement mortar.

In this specification, the term "tile cement mortar" is used in two different meanings depending on the situation. That is, the term "tile cement mortar" may mean that the aforementioned thickener for tile cement, cement and aggregate are dry beaten, or that the dry bean bean is mixed with water and kneaded.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these embodiments.

Example  1 to 2 and Comparative Example  1-2

Thickening agents for tile cements having the compositions shown in Table 1 were prepared.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Cellulose ether (% by weight) 99.0 89.0 94.0 89.0 Cyclodextrin (% by weight) 0.0 0.0 5.0 10.0 Maltodextrin (% by weight) 0.0 10.0 0.0 0.0 Caking inhibitor (% by weight) 1.0 1.0 1.0 1.0

Cellulose ether: Samsung Fine Chemicals, mecellose ^®

Cyclodextrin: Ingridian Korea, betacyclodextrin

Maltodextrin: Samyang Corporation, Genedex

Anti-caking agent: Solvay Rhodia, TIXOSIL ^®

In Table 1, the cellulose ether had a degree of methyl group substitution (DS) of 1.5, a degree of hydroxypropyl group substitution (MS) of 0.3, and a viscosity of 70,000 mPa s. Viscosity was measured in a 2.0 wt% solution at 20 [deg.] C and 20 rpm using a Brookfield viscometer.

Examples 3 to 4 and Comparative Examples 3 to 4

35% by weight of cement (a product of Dongyang Cement Co., Portland cement, KS L 5201 1), 31.5% by weight of silica sand # 6 (particle size of 600 μm or less, average particle size of 300 μm) 700 g of a preliminary tile cement mortar without a thickener for tile cement was prepared by mixing 31.5% by weight of a redispersible powder polymer (particle size 250 μm or less, average particle size 150 μm) and 2% by weight of a redispersible powder polymer (Wacker's Vinnapas 5044N) Respectively.

The tile cement mortar of Examples 3 to 4 and Comparative Examples 3 to 4 was prepared by adding the thickener for tile cement and water to 100 parts by weight of the preliminary tile cement mortar as shown in Table 2 below and then kneading.

Thickener for tile cement Kinds Comparative Example 3 Comparative Example 4 Example 3 Example 4 Content (parts by weight) 0.30 0.30 0.30 0.30 Water content (parts by weight) 24.0 23.0 23.5 23.0

In Table 2 above, the water content is adjusted to match the consistency of the mortar uniformly.

Evaluation example

(1) Density (wet density)

The densities of wetted tile cement mortar were measured.

(2) Viscosity (mortar viscosity)

Using a Brookfield viscometer and Helipath, the viscosity was measured at 5 rpm for 30 seconds to 1 minute for 10 seconds, and the average value was expressed as a viscosity value.

(3) Flowability (mortar flow)

Measured according to DIN 18555, and measured using a flow rate measuring device (Hengjin Precision, electric mortar flow tester).

(4) Visual open time

The tile cement mortar was applied to the concrete floor and allowed to stand at 23 ° C and 50% humidity for a certain period of time. Then, when the ceramic tile was removed after the ceramic tile was attached and the pressure was applied at 19.6 KN / m ² for 30 seconds, The visual open time was measured as the maximum time that the adhesion amount of the mortar can be maintained at 50% or more of the area.

Table 3 shows the results of measurement of density, viscosity, flowability, and visual open time of the tile-cement mortar of Examples 3 to 4 and Comparative Examples 3 to 4.

Comparative Example 3 Comparative Example 4 Example 3 Example 4 Density (g / cm ³⁾ 1.56 1.53 1.54 1.57 Viscosity (Pa · s) 412 396 402 410 Flow (mm) 144 145 145 146 Visual Open Time (min.) 20 25 30 35

Table 3 shows that the tile cement mortar of Comparative Examples 3 and 4 to which a thickener for tile cement not containing cyclodextrin was added was compared with the open time of the tile cement mortar of Example 3 in which a thickener for tile cement including cellulose ether and cyclodextrin was added And the open time of the tile-cement mortar of 4 are significantly increased.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be obvious to the person.

Claims (8)

Cellulose ether, and cyclodextrin. ≪ RTI ID = 0.0 > 21. < / RTI > The method according to claim 1,
Wherein the cyclodextrin is at least one selected from the group consisting of? -Cyclodextrin,? -Cyclodextrin,? -Cyclodextrin, and mixtures thereof. The method according to claim 1,
Wherein the content of the cyclodextrin is 5 to 30% by weight based on the total weight of the thickener for tile cement. The method according to claim 1,
The cellulose ether may be selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, hydroxyethyl cellulose, and mixtures thereof. Wherein the thickener for tile cement is at least one of the following. 5. The method of claim 4,
Wherein the methyl cellulose has a methyl substitution degree (DS) of 0.27 to 2.0, the hydroxypropyl methyl cellulose has a methyl substitution degree (DS) of 0.27 to 2.50 and a hydroxypropyl group substitution degree (MS) of 0.02 to 1.1, Hydroxyethyl methylcellulose has a methyl substitution degree (DS) of 0.27 to 2.40 and a degree of substitution (MS) of hydroxyethyl group of 0.03 to 1.3, and the hydroxyethyl cellulose has a degree of substitution (MS) of hydroxyethyl group of 0.3 to 5.0 Wherein the thickener for tile cement is a thickener for tile cement. The method according to claim 1,
Wherein the viscosity of the aqueous solution of cellulose ether having a concentration of 2% by weight is 10 to 200,000 mPa · s as measured by a Brookfield viscometer at 20 ° C and 20 rpm. A tile cement mortar characterized by comprising a thickener for tile cement according to any one of claims 1 to 6, cement, aggregate and redispersible powder polymer (RDP). 8. The method of claim 7,
Wherein the content of the thickener for tile cement is 0.1 to 1.0 part by weight based on 100 parts by weight of the total weight of the cement, the aggregate and the re-oiled powder resin.