KR20150050744A - Thickener for tile cement mortar and tile cement mortar containing the same - Google Patents

Abstract

The present invention relates to a thickening agent for tile cement mortar and to tile cement mortar including the same, wherein the thickening agent includes cellulose ether for tile cement mortar and hydrolyzed starch. According to the present invention, starch hydrolyzed with cellulose is included in a thickening agent for tile cement mortar, thereby improving open time of tile cement mortar including the same and simultaneously enhancing viscosity and flowability.

Description

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

The present invention relates to a tile cement mortar comprising a thickener for tile cement mortar and the thickener, and more particularly to a thickener for tile cement mortar comprising cellulose ether and hydrolyzed starch, and tile cement It is about mortar.

Tiles have been widely used as architectural finishes for a long time because of their beautiful appearance, convenience of construction, hygiene, 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 the adhesive strength have recently become important as large-size tiles are introduced as 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, It is very important to secure the open time in the construction environment where the labor cost ratio is higher than the material cost because it is directly related to the reduction of the labor cost due to the 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.

In order to solve these problems, cellulose ether as a basic raw material of natural materials has been widely used as a thickener for construction, and it is believed that it strengthens sag resistance of tile cement mortar due to high viscosity and water retention, , Due to the properties of the cellulose ether which can control the flowability which has a significant influence on the workability.

That is, these properties of the cellulose ether are such that when the tile is applied, the adhesive strength of the tile cement mortar is enhanced, the sag resistance is strengthened, the water evaporation is suppressed, the moisture is smoothly supplied to the cement, It is known that the applied tile cement has higher strength.

However, when practically cellulose ether is used as a thickener for tile cement mortar, deflection resistance and water retention are improved, but open time is not improved or rather shortened.

In order to solve such problems, Patent Document 1 (Japanese Patent Laid-Open No. 2000-128617) provides a cement mortar composition using a cellulose ether, a seawater-based water-soluble polymer and a coagulation retardant in combination. This method is to keep the surplus water in the tile cement mortar for a long time by delaying the hydration of the cement and to increase the open time by reducing the hardening of the surface of the cement mortar by the hydration product of the cement. However, according to this method, the flowability of the cement mortar can be improved and the workable time can be lengthened, but the viscosity of the mortar tends to be lowered, resulting in sagging on the wall surface.

In addition, Patent Document 2 (WO 2005/105697) discloses a method of using a mixed composition comprising a cellulose ether prepared from a raw cotton liner, an anti-sagging agent, and an additive such as a coagulation retarder as a drying tile cement composition, The sag resistance was improved, but the flowability was lowered and the workability was lowered, which did not simultaneously improve conflicting properties.

Currently, a particularly desirable property of tile cement mortar is the extension of open time, and development of a new cellulose ether additive capable of satisfying the properties of tile cement mortar used in various local and working environments is required.

JP 2000-128617 A WO 2005105697 A

A problem to be solved by the present invention is to provide a thickener for tile cement mortar having improved open time by containing cellulose ether and hydrolyzed starch.

Another object of the present invention is to provide a tile cement mortar improved in viscosity and flowability by containing the thickener.

In order to solve the above problems, the present invention provides a thickener for tile cement mortar comprising cellulose ether and hydrolyzed starch.

The hydrolyzed starch is preferably 5 to 50% by weight based on the total weight of the thickener, and at least one selected from the group consisting of glucose, starch syrup, fructose and maltodextrin is used as the hydrolyzed starch.

The cellulose ether may be selected from the group consisting of methyl cellulose, hydroxypropylmethyl cellulose, hydroxyethylmethylcellulose and hydroxyethylcellulose. More preferably, the methyl cellulose has a methyl substitution degree (DS) of 0.27 Hydroxypropylmethyl 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, and the hydroxyethyl methyl cellulose has a methyl substitution degree (DS) of 0.27 To 2.40, a degree of substitution (MS) of the hydroxyethyl group is 0.03 to 1.3, and a degree of substitution (MS) of the hydroxyethyl group of the hydroxyethyl cellulose is 0.3 to 5.0.

The viscosity of the cellulose ether aqueous solution having a concentration of 2% by weight is preferably 10-200,000 mPa · s as measured by a Brookfield viscometer at 20 ° C and 20 rpm.

The thickener may further include an anti-caking agent, and the content thereof is preferably 0.0001 to 0.01% by weight based on the total weight of the thickener.

Also, the present invention provides a tile cement mortar comprising the above-mentioned thickener, cement and aggregate, wherein the content of the thickener is 0.1 to 1.0 part by weight based on 100 parts by weight of the total amount of the cement and aggregate.

According to the present invention, by incorporating hydrolyzed starch together with cellulose into a thickener for tile cement mortar, the open time of the tile cement mortar containing the starch can be improved, and the viscosity and flowability can be improved at the same time.

The present invention relates to a thickener for tile cement mortar comprising cellulose ether and hydrolyzed starch and a tile cement mortar comprising the same.

The content of the hydrolyzed starch is preferably 5 to 50 wt% based on the total weight of the thickener, and when the content of the starch is less than 5 wt%, it is difficult to contribute to the improvement of the open time of the tile cement mortar. If a sufficient open time is not secured at the time of tile construction, the work efficiency of the operator is lowered, which is not preferable. On the other hand, when the content of the starch is more than 50% by weight, the water retention of the cellulose ether deteriorates and it is difficult to ensure sufficient hydration of the cement. If sufficient hydration of the cement can not be ensured, And defects such as dropout due to insufficient adhesive strength of the applied tile may occur.

Generally, starch is a polysaccharide in which hundreds or thousands of glucose are bonded. Amylose, which is a linear polymer having an? -1,4 glucoside bond as shown in the following formula (1) 2, amylopectin, a branched polymer with α-1,6 glucosidic bonds that form branches as well as α-1,4 glucoside bonds.

Formula 1

(2)

The starch is hydrolyzed by randomly breaking glucosidic bonds by acids, alkalis and enzymes. One or more of the hydrolyzed starches, monosaccharides, disaccharides and polysaccharides produced in this way, together with cellulose ethers, together with the tile cement mortar May be included in the thickener. More preferably, the hydrolyzed starch may include at least one member selected from the group consisting of glucose, starch syrup, fructose, and maltodextrin in the thickener of the present invention.

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 hydrolyzed starch 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 cellulose ether may be selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and hydroxyethyl cellulose. However, the cellulose ether is not limited thereto. More preferably, the methyl cellulose has a methyl substitution degree (DS) of 0.27 to 2.0, and the hydroxypropyl methyl cellulose has a methyl substitution degree (DS) of 0.27 to 2.50 and a hydroxypropyl group substitution degree (MS) And the hydroxyethylmethyl cellulose 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 a hydroxyethyl group The degree of substitution (MS) may be 0.3 to 5.0.

Here, the term "degree of substitution" means the average number of hydroxyl groups substituted with an alkyl group per anhydrous glucose unit. When the degree of methyl group substitution is high, the hydrophobicity is high and the degree of substitution of hydroxypropyl group or hydroxyethyl group In the case of a small amount, the hydrophobicity becomes 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 is preferably 10-200,000 mPa · s, more preferably 2,000-120,000 mPa · s, as measured by a Brookfield viscometer at 20 ° C. and 20 rpm . If the viscosity of the cellulose ether aqueous solution is less than 10 mPa., The effect of thickening is not exhibited. On the other hand, when the viscosity exceeds 200,000 mPa s, workability becomes very poor due to high viscosity.

The thickener for tile cement mortar of the present invention may further include an anti-caking agent. The anti-caking agent may be a filler added to improve the water dispersibility of the cellulose ether in the tile cement mortar, , And the amount thereof is preferably 0.0001 to 0.01% by weight based on the total weight of the thickener. If the addition amount is less than 0.0001% by weight, it is difficult to contribute to the dispersibility of the cellulose ether. On the other hand, when the amount exceeds 0.01% by weight, it becomes a factor to deteriorate the water retention of the cellulose ether, have. As the anti-caking agent, at least one selected from the group consisting of calcium carbonate, magnesium carbonate, fumed silica and precipitated silica may be used, but is not limited thereto.

On the other hand, the present invention provides tile cement mortar comprising the above-mentioned thickener, cement and aggregate.

The content of the thickener may be 0.1-1.0 parts by weight based on 100 parts by weight of the total amount of the cement and aggregate. If the content of the thickener is less than 0.1 parts by weight, the effect of addition is insignificant. If the content of the thickener exceeds 1.0 parts by weight, Open time can be reduced.

The cement may be hydraulic cement such as Portland cement, fly ash cement or 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. The amount of the aggregate may be 100 to 400 parts by weight based on the weight of the cement.

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 above-mentioned thickener, cement and aggregate are dry-blended, or that the dry blend was mixed with water and kneaded. In this case, the thinner the thickness of the tile cement mortar used, the greater the amount of the thickener mentioned above can be used for securing water retention.

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 (For Tile Cement Mortar) Thickener  Produce)

Cellulose ether, hydrolyzed starch maltodextrin, and fumed silica as an anti-caking agent were mixed in the weight ratios shown in Table 1 below to prepare thickener for tile cement mortar.

As the cellulose ether, hydroxypropyl methylcellulose (HPMC) having a methyl group degree of substitution (DS) of 1.5, a degree of hydroxypropyl group substitution (MS) of 0.3 and a viscosity of 50,000 mPa · s was used, The viscosity of the propyl methylcellulose was measured in a 2.0 wt% solution at 20 [deg.] C and 20 rpm using a Brookfield viscometer.

Example  2 to 3 and Comparative Example  1 (For Tile Cement Mortar) Thickener  Produce)

A thickener for tile cement mortar was prepared in the same manner as in Example 1, except that the content of cellulose ether, maltodextrin and fumed silica was adjusted as shown in Table 1 below.

Contents (wt%) Example 1 Example 2 Example 3 Comparative Example 1 HPMC 84.5 79.5 74.5 99.5 Maltodextrin 15.0 20.0 25.0 0.0 Fumed silica 0.5 0.5 0.5 0.5

Example  4 (Manufacture of tile cement mortar)

35% by weight of cement (product of Dongyang Cement Co., Portland cement, KS L 5201 1), 31.5% by weight of silica sand # 6 (particle size less than 600 탆, average particle size 300 탆), silica sand # 7 31.5% by weight, particle size 250 μm or less, average particle size 150 μm) and 2% by weight of redispersible powder polymer (Wacker's Vinnapas 5044N) were mixed to prepare 700 g of a tile cement mortar composition to which no cellulose ether was added. Subsequently, 0.3 part by weight of the thickener prepared in Example 1 was added to 100 parts by weight of the tile-cement mortar composition. 23.0 parts by weight of water was added to 100 parts by weight of the cement mortar composition, followed by kneading to prepare a tile cement mortar.

Example  5 to 6 and Comparative Example  2 (Production of tile cement mortar)

Tile-cement mortar was prepared in the same manner as in Example 4, except that water was added to 100 parts by weight of the tile-cement mortar composition by the amount shown in Table 2 below.

The water content was then adjusted to uniformly adjust the mortar viscosity of the examples, which is a general method for objectively evaluating tile cement mortars.

Example 4 Example 5 Example 6 Comparative Example 2 Water content (parts by weight) 23.0 22.0 21.8 24.0

Properties of the tile-cement mortar prepared in Examples 4 to 6 and Comparative Example 2 were evaluated by the following methods, and the evaluation results are shown in Table 3 below.

(1) Viscosity (mortar viscosity, Pa · s)

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.

(2) Flowability (mortar flow, mm)

The flowability was measured in accordance with DIN 18555 and measured using a flow rate measuring device (electric mortar flow tester, Hengjin Precision).

(3) Open time (minute)

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. After the ceramic tile was removed and the ceramic tile was removed and the pressure was applied at 19.6 KN / m ² for 30 seconds, The adhesive amount was measured as the longest time to maintain at least 50% of the area.

Example 4 Example 5 Example 6 Comparative Example 2 Viscosity (Pa · s) 528 565 545 514 Flow (mm) 136 136 137 135 Open time (minutes) 25 30 30 20

Referring to Table 3, in the case of the tile-cement mortar prepared according to Examples 4 to 6 of the present invention, the open time was significantly increased as compared with the tile-cement mortar of Comparative Example 2 in which the hydrolyzed starch was not added, And flowability are also improved at the same time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments but is to be construed as being limited only by the appended claims. Should be construed as being included in the scope of the present invention.

Claims (10)

A thickener for tile cement mortar comprising cellulose ether and hydrolyzed starch. The method according to claim 1,
Wherein the hydrolyzed starch content is 5 to 50% by weight based on the total weight of the thickener. The method according to claim 1,
Wherein the hydrolyzed starch comprises at least one member selected from the group consisting of glucose, starch syrup, fructose and maltodextrin. The method according to claim 1,
Wherein the cellulose ether comprises at least one member selected from the group consisting of methyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl methyl cellulose, and hydroxyethyl cellulose. 5. The method of claim 4,
Wherein 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, Ethyl methyl cellulose has a degree of methyl substitution (DS) of 0.27 to 2.40, a degree of substitution (MS) of hydroxyethyl group of 0.03 to 1.3, and a degree of substitution (MS) of hydroxyethyl group of hydroxyethyl cellulose of 0.3 to 5.0 Thickener for tile cement mortar. The method according to claim 1,
Wherein the aqueous solution of cellulose ether having a concentration of 2% by weight has a viscosity of 10 to 200,000 mPa.s as measured by a Brookfield viscometer at 20 캜 and 20 rpm. The method according to claim 1,
Wherein the thickener further comprises an anti-caking agent. ≪ RTI ID = 0.0 > 21. < / RTI > 8. The method of claim 7,
Wherein the content of the anti-caking agent is 0.0001 to 0.01% by weight based on the total weight of the thickener. A tile cement mortar comprising a thickener according to any one of claims 1 to 8, cement and aggregate. 10. The method of claim 9,
Wherein the content of the thickener is 0.1 to 1.0 part by weight based on 100 parts by weight of the total amount of the cement and aggregate.