KR20170012807A - Thickner for latex paint and latex paint composition including the same - Google Patents

Abstract

The present invention provides: a thickener for latex paint comprising a cross-linked cellulose ether including at least one of an acidic additive or an acidic salt additive which improves abrasion resistance and washability resistance of the latex paint; and a composition for latex paint comprising the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a thickener for latex paint, and a latex paint composition containing the latex paint composition. BACKGROUND OF THE INVENTION [0002]

The present invention relates to a thickener for latex paint and a latex paint composition containing the latex paint. More particularly, the present invention relates to a latex paint thickener for improving latex paint wearability and washability by improving the water dispersibility and solubility of latex paint thickener And a latex paint composition containing the same.

Latex paint and other finishing materials have been widely used as architectural finishes for a long time due to the protection of concrete materials, the beauty of appearance, the ease of construction, and the convenience of maintenance.

Latex paint is divided into 100% acrylic emulsion, styrene-acrylic emulsion, and vinyl emulsion depending on the type of emulsion. The market demand for eco-friendly building materials, economical efficiency and convenience of construction, The proportion of use is increasing.

In addition, latex 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. Previously, they used latex paint as exterior and interior wall coating materials. However, they continued to use eco-friendly materials, continuously regulate VOC (Volatile Organic Compounds) The finish work using latex paint is steadily increasing.

Latex paint paint is composed of resin, pigment, solvent and so on. It is very difficult to satisfactorily satisfy the required performance of the paint. In some cases, it can 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. In this case, the amount of the additive is small, but it is a very important component in the coating material.

The nature of the additive varies depending on the application and the type of the additive. However, in order to obtain a stable effect using a small amount of the additive, the additive should have compatibility with the vehicle (resin, solvent) of the paint and dispersed in the fine particles.

In particular, thickeners are used to improve the physical properties of paints during the manufacture, storage and coating of paint. When the shear rate is high as in the case of painting, the apparent viscosity is low and it should be easy to paint. The nature of the opposing paints that are not to be painted and flowed is required. That is, by adding a small amount of a thickener as an additive to the paint, it is possible to form a resin and a pigment and a net structure in the paint, and to easily break the paint by high shear force during painting. When an external force is applied, the viscosity of the additive decreases and the viscosity decreases. When the external force is removed, the net shape is restored and the viscosity rises again.

By using the thixotropy (thixotropy) phenomenon in which the structure changes with time due to a change in force externally applied and thus the structural viscosity changes, it is possible to prevent sedimentation of the pigment during storage of the paint paint or to deposit It is possible to prevent the flow and the formation of the coating at the time of coating, to control the thickness of the coating to be thick, and to improve the leveling property in the coating operation.

Existing latex paints include acrylic emulsions, pigments (extender pigments, colored pigments) and additives. To improve the workability, thickening, thixotropy, leveling, workability and water retention, , And a representative example of the water-based thickener is cellulose ether.

By adding a cellulose ether thickener to the latex paint to increase the viscosity of the emulsion, it can contribute to the stabilization of the dispersed particles like an emulsifier. In addition, it can be added to the effect of prevention of sedimentation of pigment during storage of paint, improvement of redispersibility, prevention of flow during painting, and increase of film thickness.

However, latex paints to which conventional thickener of cellulosic type is added tend to heat wear resistance and washability. Accordingly, there is a need for a thickener that improves the thick- ness, leveling, and workability of the latex paint while not deteriorating its abrasion resistance and wash-ability.

One of the technical problems to be solved by the technical idea of the present invention is to provide a thickener which does not deteriorate its abrasion resistance and washing resistance while improving the viscosity, leveling property and workability of the latex paint, and a composition for latex paint containing the thickener will be.

The thickener for latex paint according to one embodiment of the present invention may include crosslinked cellulose ether; And at least one of an acidic additive or an acidic salt additive.

As an example, the crosslinked cellulose ether may comprise from 0.01 to 2% by weight of aldehyde compound moieties.

In one embodiment, the aldehyde compound includes glyoxal, polyglyoxal, formaldehyde, pyruvaldehyde, malonaldehyde, succinaldehyde, or combinations thereof. .

For example, the crosslinked cellulose ether may be selected from the group consisting of crosslinked hydroxyethyl cellulose, crosslinked methyl cellulose, crosslinked hydroxypropyl methyl cellulose, May be at least one member selected from the group consisting of hydroxyethyl methyl cellulose, crosslinked ethyl hydroxyethyl cellulose and crosslinked methyl ethyl hydroxyethyl cellulose .

For example, the cross-linked cellulose ether may be hydroxyethyl cellulose, and the weight ratio of the hydroxyethoxyl group of the cross-linked hydroxyethyl cellulose may be 30 to 80% by weight.

For example, the acidic additive may be at least one selected from the group consisting of citric acid, tartaric acid, and maleic acid, and the acidic salt additive may be at least one selected from the group consisting of phosphate and citrate.

For example, the acid salt additive may be mono sodium phosphate.

For example, the acidic additive and / or the acidic salt additive may be 0.5 to 20.0 wt% based on the total weight of the thickener.

For example, the 1 wt% aqueous solution of the latex paint thickener may have a hydration time of 20 to 100 minutes when hydrated at 25 ° C and a pH of 8.

The composition for latex paint according to an embodiment of the present invention may include the latex paint thickener.

For example, the content of the thickener for latex paint may be 0.1 to 1.5% by weight based on the total weight of the latex paint composition.

The latex paint composition containing a thickener for latex paint according to an embodiment of the present invention is improved in wear resistance and washability, and thus, workability as a paint is not compromised.

In the present specification, the weight ratio of the hydroxyethyl group means the weight ratio of the hydroxyethyl group (R) in the total atomic weight of the elements constituting the repeating unit of the substituted cellulose, as shown in the following formula (1). Hereinafter, the same meaning is used.

[Chemical Formula 1]

Wherein R is independently -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ OH or -CH ₂ CHOHCH ₃ , and n is an integer of 1 or more.

Also, in this specification, the content of the aldehyde compound moiety in the crosslinked cellulose ether can be calculated according to the following equation (1).

[Equation 1]

(Wt.%) = Total weight of aldehyde compound moiety / gross weight of cross-linked cellulose ether x 100

Hereinafter, a thickener for latex paint and a latex paint composition containing the same according to an embodiment of the present invention will be described in detail.

The thickener for latex paint according to an embodiment of the present invention may include at least one of crosslinked cellulose ether and an acidic additive or an acidic salt additive.

The crosslinked cellulose ether may comprise from 0.01 to 2% by weight of an aldehyde compound moiety. Wherein the aldehyde compound is selected from the group consisting of glyoxal, polyglyoxal, formaldehyde, pyruvaldehyde, malonaldehyde, succinaldehyde, or combinations thereof. .

The crosslinked cellulose ether may be selected from the group consisting of crosslinked hydroxyethyl cellulose, crosslinked methyl cellulose, crosslinked hydroxypropyl methyl cellulose, crosslinked ethylhydroxyethyl < RTI ID = 0.0 > And may be at least one member selected from the group consisting of ethyl hydroxyethyl cellulose, crosslinked hydroxyethyl methyl cellulose, and crosslinked methyl ethyl hydroxyethyl cellulose.

Specifically, the cross-linked cellulose ether is hydroxyethyl cellulose, and the weight ratio of the hydroxyethoxyl (HEO) group of the cross-linked hydroxyethyl cellulose may be 30 to 80 wt% , Specifically from 45 to 75% by weight. When the weight ratio of HEO is 30 to 80% by weight, the hydroxyethyl cellulose can be used as a thickener for latex paint having high viscosity and water retention.

The crosslinked cellulose ether may also be 100 to 100,000 cps in a Brookfield viscometer at 25 ° C and 20 rpm in a 2 wt% solution.

In preparing the thickener for latex paint, a thickener for final latex paint is prepared by blending the acidic or acidic salt additives. When the thickener is added to the composition of latex paint, the solubility of the latex paint composition containing the thickener is delayed, and the thickening network of the composition is strengthened, so that the abrasion resistance and washability of the finally formed coating film can be improved .

Herein, the wash resistance refers to the ability of the dry film applied on the substrate to maintain the initial state without damaging the coating film on the external environment (eg water, other contaminants, air, dust, especially water, humidity, physical external force) It is enough. As a standard method for measuring the wash resistance, for example, ASTM D 2486-00 (Standard Test Method for Scrub Resistance of Wall Paints) may be used.

The retardation of the solubility of the composition for latex paint can be evaluated by comparing the measurement result of the hydration time of the thickener. The cross-linked cellulose ether may have a longer time to dissolve in water than the non-cross-linked cellulose ether. Accordingly, when the cross-linked cellulose ether is dissolved in water, it is more uniformly dispersed in water than in the non-cross-linked cellulose ether, and can be dissolved and dispersed uniformly in water. In addition, when blending the acidic additives and the acidic salt additives mentioned in the present invention with the crosslinked cellulose ether, the time to start dissolving in water can be further delayed. That is, the time at which the cellulose ether begins to dissolve in water and starts to exhibit viscosity is defined as the hydration time, and the latex paint containing the thickening agent of the cellulose ether in which the hydration time is delayed, The network can be strengthened to have excellent resistance to washing and abrasion.

In the case of the thickener for latex paint according to an embodiment of the present invention, the 1 wt% aqueous solution of the thickener for latex paint may have a hydration time of 20 to 100 minutes when hydrated at 25 ° C and pH 8. If the hydration time is less than 20 minutes, the washing resistance effect may not be sufficient, and if it exceeds 100 minutes, the workability and perspiration force of the latex paint may be lowered.

The acidic additive may be at least one member selected from the group consisting of citric acid, tartaric acid, and maleic acid, and specifically may be citric acid.

The acid salt additive may be at least one selected from the group consisting of phosphate and citrate. Specifically, the acid salt additive may be mono sodium phosphate or mono sodium citrate, and more specifically, may be mono sodium phosphate.

The acidic additive and / or the acidic salt additive may be 0.5 to 20.00 wt% based on the total weight of the thickener. If the content of the acidic additive and / or the acidic salt additive is less than 0.5% by weight, the effect of washing resistance may not be sufficient. If the content of the acidic additive and / or the acidic salt additive is more than 20.0% by weight, the workability and boiling point of latex paint may be lowered.

The composition for latex paint according to an embodiment of the present invention may include a thickener for latex paint according to an embodiment of the present invention.

The content of the thickener for latex paint may be 0.1 to 1.5% by weight based on the total weight of the latex paint composition. If the content of the thickener is less than 0.1% by weight, the viscosity of latex paint may not be sufficient. If the content of the thickener exceeds 1.5% by weight, the latex paint may have insufficient thixotropy.

In the latex paint composition according to an embodiment of the present invention, common additives such as emulsifiers, dispersants, defoamers and the like may be used as commonly used in this field in addition to the thickener.

Hereinafter, embodiments of the present invention will be described in detail.

The embodiments may be modified in other forms or various embodiments may be combined with each other, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments are provided so that those skilled in the art can more fully understand the present invention.

Examples 1 to 3 and Comparative Examples 1 to 3

Crosslinked hydroxyethylcellulose (Samsung Fine Chemicals, Hecellose) having an aldehyde compound moiety content of 1.0 wt% and a hydroxyethoxyl group weight ratio of 62 wt% was mixed with sodium phosphate monobasic (Youngjin Chemical) To prepare a thickener. The following Table 1 shows the viscosity measured with a Brookfield viscometer at 25 ° C and 20 rpm in a 2 wt% solution for each of the thickeners of Examples 1 to 3 and Comparative Examples 1 to 3 and the viscosity of sodium monophosphate Respectively.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Sodium Phosphate Content (wt.%) 1.0 1.5 3.0 0 0.2 0.3 Viscosity (cP) 1,540 1,500 1,355 1,184 1,344 1,495

Examples 4 to 6 and Comparative Examples 4 to 6

The compositions for latex paint of Examples 4 to 6 and Comparative Examples 4 to 6 were prepared as shown in Table 2 below. In the following Table 2, emulsifiers, dispersing agents, antifreezing agents, pH adjusting agents, antiseptics, coating film forming preparations and the like were used as additives in order to improve the physical properties of paints using emulsion resins, color pigments, extender pigments and water as a binder. .

Latex paint composition Example 4 (% by weight) Example 5 (% by weight) Example 6 (% by weight) Comparative Example 4 (% by weight) Comparative Example 5 (% by weight) Comparative Example 6 (% by weight) water 36.00 36.00 36.00 36.00 36.00 36.00 Wetting agent 0.20 0.20 0.20 0.20 0.20 0.20 Dispersant 0.40 0.40 0.40 0.40 0.40 0.40 Defoamer 0.20 0.20 0.20 0.20 0.20 0.20 Cryoprotectant 1.50 1.50 1.50 1.50 1.50 1.50 Titanium dioxide
(Colored pigment) 15.10 15.10 15.10 15.10 15.10 15.10 clay 7.10 7.10 7.10 7.10 7.10 7.10 Calcium carbonate
(Extender pigment) 16.20 16.20 16.20 16.20 16.20 16.20 Talc (extender pigment) 5.00 5.00 5.00 5.00 5.00 5.00 antiseptic 0.20 0.20 0.20 0.20 0.20 0.20 Emulsion resin 17.10 17.10 17.10 17.10 17.10 17.10 Coating formulation 0.80 0.80 0.80 0.80 0.80 0.80 pH adjusting agent 0.20 0.20 0.20 0.20 0.20 0.20 Thickener Kinds Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 content 0.51 0.50 0.53 0.55 0.54 0.52

Wetting agent: TRITON (TM) CF-10 (Dow)

Dispersant: 44S (San Nopco)

Defoamer: SN-1300 (San Nopco)

Anti-freezing agent: Ethylene glycol

Preservative: Troysan 174 (Troy chemical)

Emulsion resin: Acronal® S559 (BASF)

Coalescing agent: Texanol (Eastman chemical)

pH controller: AMP-95® (Eastman chemical)

Examples 7 to 9 and Comparative Examples 7 to 9

The compositions for latex paint of Examples 7 to 9 and Comparative Examples 7 to 9 were prepared as shown in Table 3 below. In Table 3, emulsifiers, dispersing agents, antifreezing agents, pH adjusting agents, antiseptics, coating film forming preparations and the like are added as additives in order to improve the physical properties of the paints using emulsion resins, colored pigments, extender pigments and water as a binder. .

Latex paint composition Example 7 (% by weight) Example 8 (% by weight) Example 9 (% by weight) Comparative Example 7 (% by weight) Comparative Example 8 (% by weight) Comparative Example 9 (% by weight) water 30.00 30.00 30.00 30.00 30.00 30.00 Wetting agent 0.20 0.20 0.20 0.20 0.20 0.20 Dispersant 0.30 0.30 0.30 0.30 0.30 0.30 Defoamer 0.20 0.20 0.20 0.20 0.20 0.20 Cryoprotectant 0.90 0.90 0.90 0.90 0.90 0.90 Titanium dioxide
(Colored pigment) 9.20 9.20 9.20 9.20 9.20 9.20 Calcium carbonate
(Extender pigment) 42.00 42.00 42.00 42.00 42.00 42.00 Talc (extender pigment) 4.20 4.20 4.20 4.20 4.20 4.20 antiseptic 0.20 0.20 0.20 0.20 0.20 0.20 Emulsion resin 11.00 11.00 11.00 11.00 11.00 11.00 Coating formulation 1.50 1.50 1.50 1.50 1.50 1.50 pH adjusting agent 0.30 0.30 0.30 0.30 0.30 0.30 Thickener Kinds Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 content 0.37 0.37 0.37 0.39 0.38 0.37

Wetting agent: TRITON (TM) CF-10 (Dow)

Dispersant: 44S (San Nopco)

Defoamer: SN-1300 (San Nopco)

Anti-freezing agent: Ethylene glycol

Preservative: Troysan 174 (Troy chemical)

Emulsion resin: Acronal® S559 (BASF)

Coalescing agent: Texanol (Eastman chemical)

pH controller: AMP-95® (Eastman chemical)

Evaluation example 1

Table 4 below shows the measurement of the hydration time of the thickener prepared with the compositions of Examples 1 to 3 and Comparative Examples 1 to 3. The hydration time was measured at 25 캜 for the first time after the viscosity of 1% by weight of each of the thickeners of Examples 1 to 3 and Comparative Examples 1 to 3 was mixed in an aqueous solution of pH 8 and the viscosity was started to develop.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Hydration time (minutes) 34 52 75 11 19 22

As shown in Table 4, the hydration times of Examples 1 to 3 containing 0.5 to 20.0% by weight of sodium phosphate monobasic with respect to the total weight of the thickener were comparable to those of Comparative Examples 1 to 3 You can see longer. Thus, it can be seen that the solubility of the thickener can be retarded by adding 0.5 to 20.0% by weight of the acid salt additive to the thickener.

Evaluation example 2

Table 5 below shows the results of the paint viscosity and washability test of each of the compositions for latex paint of Examples 4 to 6 and Comparative Examples 4 to 6. The paint viscosity was measured by ASTM D 562-10 and the washfastness test by ASTM D 2486-00.

Paint viscosity (KU) Washability test (cycle) Example 4 100.1 1700 Example 5 99.5 1800 Example 6 98.9 2000 Comparative Example 4 100.2 950 Comparative Example 5 101.2 980 Comparative Example 6 100.3 1000

Examples 4 to 6 in which sodium phosphate monobasic acid was added in an amount of 0.5 to 20.0% by weight based on the total weight of the thickener were similar to those of Comparative Examples 4 to 6, 4 ~ 6. ≪ / RTI > Therefore, by adding the acid salt additive to the thickener in an amount of 0.5 to 20.0% by weight based on the total weight of the thickener, the wear resistance can be improved without deteriorating the workability and other physical properties of the paint.

Table 6 below shows the results of the paint viscosity and washability test of each of the compositions for latex paint of Examples 7 to 9 and Comparative Examples 7 to 9. The paint viscosity and the washfastness test method were the same as those applied in Table 5 above.

Paint viscosity (KU) Washability test (cycle) Example 7 102.0 850 Example 8 103.2 950 Example 9 103.5 1050 Comparative Example 7 98.5 500 Comparative Example 8 99.5 550 Comparative Example 9 98.1 580

Referring to Table 6, in Examples 7 to 9 in which sodium phosphate monobasic acid was added in an amount of 0.5 to 20.0% by weight based on the total weight of the thickener, the paint viscosity was similar to that of Comparative Examples 7 to 9, 7 ~ 9. Therefore, it can be seen that the abrasion resistance can be improved without deteriorating the workability of the paint by adding the acid salt additive to the thickener in an amount of 0.5 to 20.0% by weight based on the total weight of the thickener.

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 (11)

Crosslinked cellulose ethers; And
At least one of an acidic additive or an acidic salt additive. The method according to claim 1,
Wherein the crosslinked cellulose ether comprises from 0.01 to 2% by weight of an aldehyde compound moiety. 3. The method of claim 2,
The aldehyde compound is characterized in that it comprises glyoxal, polyglyoxal, formaldehyde, pyruvaldehyde, malonaldehyde, succinaldehyde, or a combination thereof Thickener for latex paint. The method according to claim 1,
The crosslinked cellulose ether may be selected from crosslinked hydroxyethyl cellulose, crosslinked methyl cellulose, crosslinked hydroxypropyl methyl cellulose, crosslinked hydroxyethyl methyl < RTI ID = 0.0 > Wherein the latex is at least one selected from the group consisting of hydroxyethyl methyl cellulose, crosslinked ethyl hydroxyethyl cellulose and crosslinked methyl ethyl hydroxyethyl cellulose. Thickener for paints. The method according to claim 1,
The crosslinked cellulose ether is crosslinked hydroxyethyl cellulose,
Wherein the weight ratio of the hydroxyethoxyl group of the cross-linked hydroxyethyl cellulose is 30 to 80% by weight. The method according to claim 1,
The acidic additive is at least one member selected from the group consisting of citric acid, tartaric acid and maleic acid,
Wherein the acid salt additive is at least one selected from the group consisting of phosphate and citrate. The method according to claim 6,
Wherein the acid salt additive is mono sodium phosphate. The method according to claim 6,
Wherein the acidic additive and / or the acidic salt additive is 0.5 to 20.0% by weight based on the total weight of the thickener. The method according to claim 1,
Wherein the 1 wt% aqueous solution of the thickener for latex paint has a hydration time of 20 to 100 minutes when hydrated at 25 ° C and a pH of 8. A latex paint composition comprising the latex paint thickener according to any one of claims 1 to 9. 11. The method of claim 10,
Wherein the content of the thickener for latex paint is 0.1 to 1.5% by weight based on the total weight of the composition for latex paint.