KR20140092479A - Thickener for Aqueous Paint with Improved Workability and Paint Properties and Aqueous Paint Containing the Same - Google Patents

Abstract

The present invention relates to a thickener for aqueous paint and an aqueous paint composition comprising the same. The thickener for aqueous paint according to the present invention is cellulose ether blending two or more kinds from a group composed of hydroxyalkyl cellulose cross-linked by an aldehyde compound; hydroxylalkyl cellulose cross-linked by an aldehyde compound and having a substituted hydrophobic group; and hydroxyl alkylalkyl cellulose cross-linked by an aldehyde compound, wherein the aqueous paint comprising the thickener has not only workability but also excellent characteristics of paint properties like storage properties, repairing properties, leveling properties, and color expression.

Description

TECHNICAL FIELD [0001] The present invention relates to a thickener for water-based paints and a water-

The present invention relates to a thickener for an aqueous paint and an aqueous paint to which the same is applied. More particularly, the present invention relates to a thickener for water-based paints capable of improving paint properties such as storability, water retention, leveling efficiency, leveling property and water retention as well as workability through blending two or more kinds of cellulose ether thickeners crosslinked with an aldehyde compound And to a water-based paint using the same.

Water-based paint and other finishing materials have been widely used as building finishing materials for many years due to the protection of concrete materials, the beauty of appearance, the convenience of construction, and the ease of maintenance.

Water-based paints are classified into 100% acrylic emulsion, styrene-acrylic emulsion and vinyl-based emulsion depending on the type of emulsion. Due to the market demand, economic efficiency and convenience of construction materials for eco-friendly construction materials, water- The proportion of use is increasing.

Also, water-soluble paints, which are used as major finishes in the world, are divided into external and internal paints depending on the application. In the existing domestic construction market, more than 60% of the residential buildings are apartment-based. Conventionally, water-based paints are used as exterior and interior wall coating materials. However, with the enforcement of environmental regulations for environment-friendly materials, The number of finishes has increased steadily.

Water-based paints include resins, pigments, and water, which are very difficult to satisfactorily satisfy the required performance of a paint, and may not be solved by resin or pigment alone. In this case, it is possible to improve the physical properties of the coating material by using the additive. At this level, the amount of the additive to be used is small, but it is a very important component in the coating material.

The properties of the additive vary depending on the purpose and the type of use. However, in order to obtain a stable effect by using a small amount of the additive, the paint must be compatible with the vehicle (resin, solvent) or dispersed in fine particles.

In particular, thickening agents are used to improve the physical properties of paints during the manufacture, storage, and formation of paint coatings. When the shear rate is high as in coating, the viscosity is low so that it is easy to coat. On the other hand, And it is required to have opposite properties that should not flow. In other words, by adding a small amount of thickener, which is an additive to the paint, it forms a resin, pigment and net structure in the paint, which is easily broken by the high shear force at the time of coating so that the viscosity is lowered by the additive and viscosity is lowered, When removed, the net shape recovers and the viscosity rises again.

By using the thixotrophy phenomenon in which the structural viscosity changes due to a change in structure with time due to a change in force externally applied, it is possible to prevent sedimentation of the pigment during storage of the paint paint or to prevent sedimentation It is possible to prevent the flow and the flow of paint during painting and to control the thickness of the film thickly. It improves the brush workability and paint workability and improves the brush marks and leveling ability at the work.

Conventional water-based paints are produced by using acrylic emulsions, pigments (extender pigments, colored pigments), and additives. They are used for preventing layer separation of paint paints, improving workability, thickening, irregularity, leveling property, workability and water retention And a representative example of the water-based thickener is cellulose ether.

A cellulose ether thickener is added to the aqueous coating to increase the viscosity of the emulsion, which contributes to the stabilization of the dispersed particles like an emulsifier. In addition, it is effective to prevent sedimentation of the pigment during storage of the paint, improve the redispersibility, prevent the flow during painting, and increase the thickness of the film by adding it at the time of coating.

Hydroxyethylcellulose, hydroxyethylcellulose substituted with a hydrophobic group, and hydroxypropylmethylcellulose are mainly used as the cellulose ether thickener depending on the substituent. In each of these cases, specifically, the hydroxypropylmethylcellulose has an advantage of obtaining a high paint viscosity even when a small amount is used, since the hydroxypropyl methylcellulose has a good thickening efficiency. However, In the case of ethylcellulose, color development is excellent and bubble formation is advantageous. However, there is a disadvantage in that the paint is hardly developed and the viscosity is lowered at the time of roller or brushing operation. In the case of hydroxyethyl cellulose substituted with hydrophobic group, There is a drawback in that the thickening efficiency is lowered and the leveling property and storage stability are lowered. Therefore, there are differences in the properties imparted when applied to paints depending on the kind of the cellulose ether thickener.

Accordingly, the market for architectural finishes still requires thickeners to improve workability and paint properties.

The present inventors have conducted studies to solve the problems of conventional cellulose ether thickeners and found that when blending two or more kinds of cellulose ethers cross-linked with aldehydes and using them as thickeners, not only workability but also storability, water retention, leveling property, Thereby improving the physical properties of the paint such as coloring efficiency and color development, thereby completing the present invention.

Accordingly, a problem to be solved by the present invention is to provide a thickener for water-based paint which can improve paint properties as well as workability.

Another object of the present invention is to provide an aqueous paint composition containing a thickener for water-based paint which can improve not only workability but also paint properties.

In order to solve the above-mentioned problems, the present invention provides a method for producing a hydroxyalkylcellulose crosslinked with an aldehyde compound, a hydroxyalkylcellulose substituted with a hydrophobic group crosslinked with an aldehyde compound, and a hydroxyalkylalkylcellulose crosslinked with an aldehyde compound, The present invention provides a thickener for water-based paints comprising the above blended cellulose ether.

In the thickener for aqueous paint according to the present invention, the hydroxyalkyl cellulose has a hydroxyalkyl group substitution degree of 45 to 75%, and the hydrophobic group-substituted hydroxyalkyl cellulose has a hydroxyalkyl group substitution degree of 45 to 75% , The substitution degree of the hydrophobic group is 0.1 to 3%, the hydroxyalkyl alkyl cellulose has an alkyl group substitution degree of 20 to 30%, and a hydroxyalkyl group substitution degree of 5 to 10%.

The hydroxyalkylcellulose is preferably hydroxyethylcellulose, and the hydrophobic group-substituted hydroxyalkylcellulose is preferably hydrophobic-group-substituted hydroxethylcellulose, and the hydroxyalkylcellulose may be hydroxypropylmethylcellulose or hydroxypropylmethylcellulose. Hydroxyethyl methylcellulose is preferable.

The cellulose ether preferably has a viscosity of 1,000 to 100,000 cps as measured on a Brookfield viscometer at 20 DEG C and 20 rpm based on 2 wt% aqueous solution.

The blended cellulose ether is preferably blended with hydroxyalkylcellulose and hydroxyalkylcellulose in which hydroxyalkylcellulose and hydroxyalkylcellulose are blended or substituted with a hydrophobic group. The blending ratio is preferably in the range of 50 to 10:50 to 90 by weight, and the cellulose ether used in the above should be all cellulose ether crosslinked with an aldehyde compound in order to prevent lumps when the paint is applied.

In order to solve the other problems, the present invention provides a water-based paint composition comprising a hydroxyalkylcellulose crosslinked with an aldehyde compound as a thickener, a hydroxyalkylcellulose substituted with a hydrophobic group bridged with an aldehyde compound, and a hydroxyalkylcellulose crosslinked with an aldehyde compound Wherein the water-based paint composition comprises at least two kinds of cellulose ethers blended in the group consisting of alkyl alkylcelluloses.

In the aqueous paint composition according to the present invention, the cellulose ether thickener is preferably contained in a proportion of 0.1 to 2% by weight based on the total weight of the aqueous paint composition.

The aqueous paint composition to which the thickener composition for aqueous paint according to the present invention is applied can achieve the following effects.

First, it improves workability when applying paint, especially roller, brush, and spray.

Secondly, the paint properties such as storage stability, water retention, thickening efficiency, leveling property and color development are improved excellent overall.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a cellulose ether thickener blended with at least two compounds selected from the group consisting of hydroxyalkylalkylcellulose crosslinked with an aldehyde compound, hydroxyalkylcellulose substituted with a hydrophobic group crosslinked with an aldehyde compound, and hydroxyalkylcellulose crosslinked with an aldehyde compound The present invention can provide a water-based paint which is used to improve the viscosity efficiency and improve the paint properties such as storage stability, viscosity efficiency, leveling property, water retention property, storage property and color development as a whole.

According to one embodiment of the present invention, there is provided a composition comprising a hydroxyalkylcellulose crosslinked with an aldehyde compound, a hydroxyalkylcellulose substituted with a hydrophobic device crosslinked with an aldehyde compound, and a hydroxyalkylalkylcellulose crosslinked with an aldehyde compound Two or more blended cellulose ether thickeners.

According to this embodiment, the aldehyde compound crosslinking the cellulose ether is preferably selected from the group consisting of formaldehyde, acetaldehyde, glyoxal, methylglyoxal, and phenylglyoxal, and the aldehyde compound is selected from the group consisting of cellulose It is preferably used in the range of 0.1 to 2.5% by weight based on the total weight of the ether. By dissolving the aldehyde compound in the cellulose ether, the dissolution of the cellulose ether can be delayed.

When the aldehyde compound is crosslinked at less than 0.1% by weight, the amount of the aldehyde compound to be crosslinked is too small to be used as a lump when added to an aqueous paint. When the crosslinking exceeds 2.5% by weight, the dissolution delay time becomes too long, Which can lead to direct problems with paint productivity.

In the hydroxyalkylcellulose cross-linked with the aldehyde compound, the substitution degree of hydroxyalkyl is preferably 45 to 75%. Here, the degree of substitution refers to the average weight percent of hydroxyalkyl groups bonded per unit of cellulose of hydroxyalkylcellulose. When the degree of substitution is less than 45%, the endogenous degradability of the aqueous solution is poor, and when the degree of substitution is less than 75% , It is not produced because the production efficiency is lowered. Here, alkyl is methyl, ethyl, propyl and the like, and the hydroxyalkylcellulose is preferably hydroxyethylcellulose.

In the hydroxyalkylalkylcellulose crosslinked with the aldehyde compound, the substitution degree of the hydroxyalkyl group is from 5 to 10%, and the substitution degree of the alkyl group is preferably from 20 to 30%. Here, the degree of substitution means the average weight percent of the hydroxyalkyl group or alkyl group bonded per cellulose unit of hydroxyalkyl alkyl cellulose, and when the substitution degree of the hydroxyalkyl group is less than 5% or the substitution degree of the alkyl group is less than 20% When the degree of substitution of hydroxyalkyl group is more than 10% or the degree of substitution of alkyl group is more than 30%, the production efficiency is lowered, and therefore, it is not produced. Here, alkyl is methyl, ethyl, propyl and the like, and the hydroxyalkyl alkyl cellulose is preferably hydroxypropyl methylcellulose.

In the hydrophobic group-substituted hydroxyalkylcellulose crosslinked with the aldehyde compound, the degree of substitution of the hydroxyalkyl group is preferably 45 to 75%, and the degree of substitution of the hydrophobic group is preferably 0.1 to 3%. Wherein the degree of substitution refers to the average weight percent of hydroxyalkyl groups or hydrophobic groups bonded per unit cellulose of hydrophobic group substituted hydroxyalkylcellulose and wherein the degree of substitution of hydroxyalkyl groups is less than 45% and the degree of substitution of hydrophobic groups is less than 0.1% , There is little improvement in workability due to less recrystallization with latex particles, and production is difficult and productivity is inferior when the substitution degree of hydroxyalkyl group is more than 75% and the substitution degree of hydrophobic group is more than 3% . Here, alkyl is methyl, ethyl, propyl, etc., and the hydrophobic group is a long chain alkyl group, and preferably has 4 to 20 carbon atoms. When the number of carbon atoms is less than 4, the effect of improving workability is small because of less occurrence of latex particles. When the number of carbon atoms is more than 20, workability is deteriorated due to excessive associative ability and paint viscosity can be excessively high.

The cellulose ether preferably has a viscosity of 1,000 to 100,000 cps as measured on a Brookfield viscometer at 20 DEG C and 20 rpm based on 2 wt% aqueous solution. When the viscosity of the cellulose ether is 1,000 or less, the viscosity is low and the amount of the cellulose ether to be used is increased. On the other hand, in the case of cellulose ether having a weight of 100,000 or more,

More preferably, the cellulose ether thickener is blended with a hydroxyalkylcellulose blended with a hydroxyalkylalkylcellulose and a hydroxyalkylcellulose or a hydrophobic group substituted with a hydroxyalkylcellulose. When blended, the blending ratio of the hydroxyalkylcellulose and the hydroxyalkylcellulose, Is preferably from 50 to 10: 50: 90 by weight. When the amount of the hydroxyalkylcellulose substituted with the hydrophobic group is less than 50%, there is a disadvantage in that color rendering and leveling properties are poor in the physical properties of the paint, and when the hydroxyalkylalkylcellulose is used in an amount of 50% or more, The pinholes or lumps may appear on the outer surface of the paint film after the paint film is formed.

According to another embodiment of the present invention, in the water-based paint composition, hydroxyalkylcellulose crosslinked with an aldehyde compound as a thickener, hydroxyalkylcellulose substituted with a hydrophobic group crosslinked with an aldehyde compound, and hydroxyalkyl And at least two blended cellulose ethers in the group consisting of cellulose.

According to this embodiment, it is preferable that the cellulose ether thickener is contained in the aqueous paint composition in a proportion of 0.1 to 2% by weight. When the thickener is used in an amount of less than 0.1% by weight, the amount of the thickener used is insufficient, so that no physical properties such as coating film formation, sagging and water retention can be obtained in the paint. The problem of workability and the amount of input may increase, resulting in price problems.

In addition to thickeners, water, pigment and water-soluble emulsion dispersants, defoamers, and the like can be added to the aqueous paint compositions according to this embodiment as commonly used additives in the art.

For example, the water used in the aqueous paint composition may be included within the range commonly used in the art, preferably 25 to 45 wt% water being used based on the total weight of the paint composition.

In addition, as the pigment, a coloring pigment such as titanium dioxide may be used, and may also include a body pigment such as aluminum silicate, calcium carbonate, talc, or a combination thereof.

Here, the pigment may be contained within a range generally used in this field, and is preferably included within a range of 35 to 55 wt% based on the total weight of the paint composition

As another water-soluble emulsion, a vinyl acetate emulsion or an acrylic emulsion can be used.

 The vinyl acetate emulsion or the acrylic emulsion may be prepared by emulsion polymerization of a vinyl acetate monomer composition or an acrylic monomer composition in an aqueous medium (e.g., water) in the presence of a polyvinyl alcohol-based material.

The polyvinyl alcohol-based material may include an anion-modified polyvinyl alcohol such as a sulfonic acid-modified polyvinyl alcohol, a carboxylic acid-modified polyvinyl alcohol, or a combination thereof.

The vinyl acetate-based monomer composition may include a vinyl acetate-based monomer, and the acrylic monomer composition may include an acrylic monomer.

In addition, the vinyl acetate-based monomer composition and the acrylic monomer composition may further include other components.

The vinyl acetate-based monomer may include vinyl acetate. Examples of the acrylic monomer include ethyl acrylate, ethyl methacrylate, methyl acrylate, methyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate , Butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, cyclohexyl acrylate, alkoxyethyl acrylate, or combinations thereof.

The other component may be a monomer copolymerizable with the vinyl acetate-based monomer and the acrylic monomer (e.g., divinylbenzene, divinyl adipate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) Acrylate); Water-soluble oligomers (e.g., 2-methacrylamide-2-methylpropanesulfonic acid copolymer, sodium methacrylate-4-styrene sulfonate copolymer, polyvinylpyrrolidone, poly (meth) acrylate); Polymerization initiators (for example, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide); Polymerization regulators (e. G., Methanol, ethanol, propanol, acetone, dodecyl mercaptan); Emulsifiers (e. G., Sodium lauryl sulfate), and combinations thereof.

The water-soluble emulsion may be contained within a range generally used in this field, and is preferably contained within a range of 10 to 20% by weight, based on the total weight of the paint composition.

The dispersing agent may include sodium citrate, calcium stearate, zinc stearate, distearyldimethylammonium chloride, or a combination thereof.

The defoamer may be selected from the group consisting of dimethylpolysiloxane, silicone, silica, sorbitan monostearate, silicone resin, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, mineral oil, .

Examples of the preservative include methanethiol, ethanethiol, 1-propanethiol, 2-propanethiol, butanethiol, tert-butyl mercaptan, pentanethiol, coenzyme A, glutathione, cysteine, 2- mercaptoethanol, dithioerythritol, 2-mercapto indole, transglutaminase, or a combination thereof.

The pH adjusting agent may include ammonia anhydride, ammonium phosphate, dimethylethanolamine, formic acid, sodium bicarbonate, sodium hydrogencarbonate, triethylamine or a combination thereof.

In addition, additives common to this field can be used within the general scope used in this field.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

Examples 1 to 4

Manufacture of cellulose ether thickener

Cellulose ether thickeners 1 and 2 were prepared by mixing 50 wt.% And 30 wt.% Of HPMC and 50 wt.% And 70 wt.% Of HEC, respectively, among the respective cellulose ethers listed in Table 1 below. Cellulose ether thickeners 3 and 4 were then prepared by mixing 50 wt.% And 30 wt.% Of HMHEC with 50 wt.% And 70 wt.% Of HEC, respectively.

MeO (%) HPO (%) HEO (%) Cetyl (%) Viscosity (cps) HPMC 25 7.5 - - 52,000 HMHEC - - 66 0.5 4,100 HEC - - 63 - 13,660

HPMC: hydroxypropylmethylcellulose

HMHEC: hydrophobic (cetyl) substituted hydroxyethylcellulose

HEC: Hydroxyethylcellulose

Viscosity: Based on the viscosity of a 2 wt% aqueous solution measured at 20 캜 and 20 rpm by Brookfield viscometer

Preparation of aqueous paint composition

Using the cellulose ether thickener prepared above, water-based paint compositions were prepared by blending with the components shown in Table 2 below in a blending ratio. That is, an emulsifier, a dispersant, a defoaming agent, a cryoprotectant, a pH adjuster, an antiseptic agent, a film-forming aid, a thickener, etc. are added as an additive in order to improve the physical properties of the paint using acrylic emulsion resin, colored white pigment, extender pigment, To prepare a water-based paint. In Table 2, the unit of the content of each component is% by weight.

Aqueous paint composition Water Paint Composition Ratio (wt%) water 37 Wetting agent 0.2 Dispersant 0.4 Defoamer 0.2 Cryoprotectant 1.5 Titanium dioxide (white pigment) 15.1 Aluminum silicate (extender pigment) 7.1 Calcium carbonate (extender pigment) 14.8 Talc (extender pigment) 5.0 antiseptic 0.2 Styrene-acrylic emulsion 17.1 pH adjusting agent 0.2 Coating formulation 0.8 Cellulose ether thickener 0.4 all 100

* Wetting agent: Product name CF-10 sold by DOW

Dispersant: Product name 44S sold by Sanocof Co., Ltd

* Antifoaming agent: Product name SN-1300 sold by Sanocof Co., Ltd

* Freezing agent: Ethylene glycol

* Color pigments: Titanium oxide (TiO ₂ )

* Extention Pigment: Calcium carbonate, talc,

* Styrene acrylic emulsion (Acronal ^® S559 sold by BASF)

* Preservative: Troysan 174 available from Troy chemical corp.

* pH adjusting agent: AMP-95 ^® sold by Eastman chemical company

* Coating formulation: Texanol ™ sold by Eastman chemical company

Comparative Examples 1 to 3

An aqueous paint composition was prepared in the same manner as in the above Example except that hydroxypropylmethylcellulose, hydroxyethylcellulose substituted with a hydrophobic group, and hydroxyethylcellulose were used alone as a thickener.

Evaluation example

The properties of the aqueous paint compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated by the following physical property evaluation methods. The results are shown in Table 3 below.

(Storability)

After each aqueous paint composition was stored at room temperature for 1 month, the degree of occurrence of the precipitate was evaluated as grade 3 as follows. The smaller the degree of occurrence of sediment, the better the storability.

?: Excellent,?: Good,?: Fair

(Thickening efficiency)

Means the viscosity of the paint KU obtained by adding the same amount of the cellulose ether thickener, and the higher the value, the better the thickening efficiency.

(Leveling property)

Using the leveling measuring apparatus (Leveling Measurement of Sheen Instruments Limited), the spreadability of each of the aqueous paint compositions was evaluated as grade 3 as follows. The greater the spreadability, the better the leveling property.

?: Excellent,?: Good,?: Fair

(Workability)

Each of the above aqueous paint compositions was applied to a slate (bare slat) using an aqueous roller (aqueous roller of artisan brush). During the coating operation, the degree of splashing of each of the aqueous paint compositions to the periphery was visually observed, and the workability was evaluated as grade 3 as follows. The more the water-based paint composition does not bounce well to the periphery, the better the workability.

?: Excellent,?: Good,?: Fair

(Conservative)

A 5A filter (manufactured by Toyo Roshi Kaisha, Ltd.) Was placed on the lower end of a ring having a diameter of 100 mm and a height of 10 mm on a glass plate. The ring was filled with a sufficiently kneaded paste, and after 30 minutes, a 5A filter (filter size: Water was absorbed and the spreading diameter was measured to evaluate water retention.

The conservatism formula is as follows.

(%) = (1 - ((diameter of wet filter paper after 30 minutes (mm) -100) / 100)) * 100 "

(Color development)

The color development was carried out by making white paint and then comparing the degree of color developed according to the difference of the thickener by adding the same amount of colored pigment. In the experiment, 5% of colored pigment was added to the white paint prepared by using the paint formulation of Table 2 And uniformly stirred, and a 100 micron coating film is formed on the cover paper using a film applicator. After drying the coating for more than 40 hours, prepare the specimen and record the color difference between standard and standard using a colorimeter.

?: Excellent,?: Good,?: Fair

Cellulose ether Zhejiang Province Thickening
efficiency Leveling ability Workability Conservative
(%) Color development HPEC / HMHEC HEC Example 1 HPEC 50% HEC 50% ◎ 105 △ ○ 90 ○ Example 2 HPEC 30% HEC 70% ○ 99 ○ ◎ 87 ◎ Example 3 HMHEC 50% HEC 50% ○ 104 ○ ○ 90 ○ Example 4 HMHEC 30% HEC 70% ○ 101 ○ ○ 88 ◎ Comparative Example 1 HPMC 100% - ◎ 110 △ △ 95 △ Comparative Example 2 - HEC 100% ○ 102 ○ ○ 88 ◎ Comparative Example 3 HMHEC 100% - △ 95 ◎ ◎ 84 ◎

In the case of the aqueous paint compositions prepared in Comparative Examples 1 to 3, since the cellulose ether thickener was used alone, the physical properties were superior to the physical properties, and the physical properties tended to be different from those of the physical properties, In Examples 1 to 4 in which the cellulose ether thickener was blended in two kinds, it was generally excellent in overall physical properties such as storage stability, thickening efficiency, leveling property, workability, water retention and color development.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (9)

Hydroxyalkylcellulose crosslinked with an aldehyde compound; Hydroxyalkylcellulose substituted with a hydrophobic group crosslinked with an aldehyde compound; And a hydroxyalkyl alkylcellulose crosslinked with an aldehyde compound. 2. The aqueous thickener according to claim 1, The method according to claim 1,
Wherein the hydroxyalkyl cellulose has a degree of substitution of hydroxyalkyl groups of 45 to 75% and the substitution degree of hydroxyalkyl groups of the hydrophobic group is 45 to 75% and the substitution degree of the hydrophobic group is 0.1 to 3% , The hydroxyalkyl alkylcellulose has an alkyl group degree of substitution of 20 to 30% and a hydroxyalkyl group degree of substitution of 5 to 10%. The method according to claim 1,
Examples of the hydroxyalkylcellulose include hydroxyethylcellulose, the hydrophobic group-substituted hydroxyalkylcellulose is hydrophobic group-substituted hydroxethylcellulose, and the hydroxyalkylalkylcellulose is hydroxypropylmethylcellulose or hydroxyethylmethylcellulose. Examples of the hydroxyalkylcellulose include hydroxypropylcellulose, Thickener for aqueous paint, cellulose. The method according to claim 1,
Wherein the cellulose ether has a viscosity of from 1,000 to 100,000 cps as measured on a Brookfield viscometer at 20 DEG C and 20 rpm on a 2 wt% aqueous solution. The method according to claim 1,
Wherein the blended cellulose ether is a blend of hydroxyalkyl alkyl cellulose and hydroxyalkyl cellulose. The method according to claim 1,
Wherein the cellulose ether to be blended is a blend of a hydroxyalkyl cellulose substituted with a hydrophobic group and a hydroxyalkyl cellulose. The method according to claim 5 or 6,
Wherein the blending ratio is 50 to 10: 50 to 90 based on weight. In the water-based paint composition, at least two kinds of blending in the group consisting of hydroxyalkylcellulose crosslinked with an aldehyde compound as a thickener, hydroxyalkylcellulose substituted with a hydrophobic group crosslinked with an aldehyde compound, and hydroxyalkylalkylcellulose crosslinked with an aldehyde compound Lt; RTI ID = 0.0 > cellulose ether < / RTI > as a thickener. 9. The method of claim 8,
Wherein the cellulose ether thickener comprises from 0.1 to 2% by weight based on the total weight of the aqueous paint composition.