JPH02308887A - Water resin composition for sealer - Google Patents

Abstract

PURPOSE:To provide the subject composition containing an emulsified dispersion of a specific vinyl copolymer and lithium silicate at a specific ratio, exhibiting excellent adhesivity to a substrate independent of the property and shape of the substrate and having high compatibility and shelf stability. CONSTITUTION:The objective composition contains (A) an emulsified dispersion liquid of a vinyl copolymer having carboxyl group and alkoxysilyl group and (B) lithium silicate at a weight ratio of 40:60 to 90:10 in terms of solid components. A preferable example of the component A is a copolymer produced by the emulsion copolymerization of a monomer mixture consisting of 35-99.4wt.% of (meth)acrylic acid ester, 0-64.4wt.% of styrene (derivative), 0.5-5wt.% of an alpha,beta-monoethylenic unsaturated carboxylic acid and 0.1-5wt.% of a compound having polymerizable unsaturated double bond and alkoxysilyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new and useful aqueous resin composition for sealers. More specifically, the present invention provides a sealer for use in surface coating of building materials and architectural structures, which comprises a specific emulsion copolymer and lithium silicate as essential components. The present invention relates to an aqueous composition of the invention.

[Conventional technology]

In recent years, in the fields of civil engineering and architecture, so-called building materials used for construction, structures, wall materials, etc. are being painted on-site or on factory lines to improve their durability or aesthetic appearance. is increasing.

By the way, most of the building materials used for these constructions, structures, wall materials, etc. are so-called inorganic substances such as cement and silicate, so when painting, it is difficult to adhere to the top coat. A sealer is applied to improve the properties and appearance of the finish.

However, due to their nature, such inorganic base materials are susceptible to weathering. For example, in the case of on-site painting, the surface may become brittle due to long-term weathering, or in rare cases, for many years. There are often situations where the weakened layer must be physically removed and reinforced with a sealer. However, removing the weakened layer requires a great deal of effort.

On the other hand, when painting is done on a factory line, the base material usually does not become brittle due to weathering, but depending on the method used to prepare the base material, the surface of the base material can range from brittle to extremely dense. That's how it is.

By the way, it goes without saying that the basic performance required of this sealer is, first of all, good adhesion of the sealer to these base materials and good adhesion of the top coat to the sealer surface. It is.

However, in the case of a base material with a fragile surface as mentioned above, the sealer inevitably penetrates into the inside of the base material sufficiently.
Unless it solidifies and reinforces such weak areas, good apparent adhesion cannot be obtained, and even in the case of very dense substrates as mentioned above, After all, unless the sealer penetrates and solidifies from the surface of the base material to the inside and exhibits an anchoring effect, a product with sufficient adhesion cannot be obtained.

Thus, sealers that have good adhesion to extremely brittle or extremely dense substrates are currently not available.
The reality is that it has not yet been discovered.

Incidentally, there are two methods: a method using so-called acrylic silag, in which an acrylic monomer and/or a low-molecular-weight composition made of the acrylic monomer is infiltrated into a base material, and then solidified through a radical reaction, and a method using a low-molecular-weight moisture-curing polyurethane. Although these methods have also been put into practical use, it is hard to say that any of them can exhibit sufficient adhesion to substrates.

Furthermore, whether these acrylic silage or moisture-curing polyurethane are used, the chlorine and organic solvents contained in them significantly deteriorate the working environment, and there is a high risk of fire and environmental pollution. It cannot be said that it is a preferable material.

[Problem to be solved by the invention]

However, in view of the above-mentioned drawbacks in the prior art, the present inventors have begun intensive research in order to provide an extremely useful sealer that is currently required for this type of building material.

Therefore, the problem to be solved by the present invention is to - be applicable to both cases where the substrate surface is brittle and dense, and to have good adhesion to the substrate. Furthermore, it is an object of the present invention to provide an extremely useful water-based sealer that does not deteriorate the working environment and has no concerns about fire or environmental pollution.

[Means to solve the problem]

Therefore, as a result of extensive research focusing on the unresolved problems of the prior art and the problems to be solved by the present invention, the present inventors have hereby found a specific an emulsified dispersion of a vinyl copolymer;
The inventors have discovered that an aqueous resin composition containing lithium silicate as an essential component is a sealer that has excellent adhesion to various substrates and also has good adhesion to various top coatings. As a result, we have completed the present invention.

That is, the present invention uses, as essential components, an emulsified dispersion (A) of a vinyl copolymer having both a carboxyl group and an alkoxysilyl group, and lithium silicate (B).
:(B) in a solid content weight ratio of 40:60 to 90:10.

Here, an emulsified dispersion of a vinyl copolymer having both carboxyl groups and alkoxysilyl groups (A
), but those that can meet the purpose of the present invention are particularly the following (meth)acrylic acid alkyl esters (a-1):
35 to 99.4% by weight of styrene or its derivative (a-2), 0 to 64.4% by weight of styrene or its derivative (a-2), and α,β-monoethylenically unsaturated cal? At least one polymerizable unsaturated double bond (hereinafter referred to as unsaturated bond ) and an alkoxysilyl group (hereinafter abbreviated as monomer (a-4)). It is desirable to use an emulsion copolymer (copolymer emulsion) obtained by polymerization.

Among these, we will cite only the most representative ones as the above (meth)acrylic acid alkyl ester (a-1): methyl (meth)acrylate, ethyl (meth)acrylate, and (meth)acrylic acid. -n-butyl, isobutyl (meth)acrylate, -te (meth)acrylate
Examples include rt-butyl or 2-ethylhexyl (meth)acrylate, and furthermore, cyclohexyl (meth)acrylate and the like can be used similarly.

Then, the (meth)acrylic acid alkyl ester (a
-1) is used alone or as a mixture of two or more in an amount of 35 to 99.4% by weight based on the total monomers.

Then, the above-mentioned styrene or its derivative (a-2)
Typical examples include styrene, α-methylstyrene, p-tert-butylstyrene, and vinyltoluene. The styrene derivative (a-2) is used in an amount of 0 to 64.4 mol based on the total monomers. Applicable within the range of %.

The monomer (a-2) was divided into 64% styrene.
If it is used in an amount exceeding 4% by weight, the resulting emulsion copolymer will inevitably have poor film-forming properties, which is not preferable.

In addition, the above-mentioned unsaturated carboxylic acids (a-3) are limited to particularly representative examples, such as (meth)acrylic acid, maleic acid or its half-ester, fumaric acid or its half-ester, and itacon. The monomer (a-3) may be used alone or in combination of two or more types, and the amount of the monomer (a-3) to be used is based on the total monomers. ,0
．． A range of 5 to 5% by weight is suitable.

The unsaturated carboxylic acid (a-3) is used to improve the mixing stability of the lithium silicate (B), which is another essential component of the composition of the present invention, with the emulsion copolymer dispersion (A). 0.0.
If it is less than 5% by weight, the performance improvement effect will not be exhibited, while if it exceeds 5% by weight,
Either case is unfavorable because the resulting emulsion copolymer inevitably has poor alkali resistance.

Furthermore, the monomers (a-4) mentioned above are only particularly representative examples: divinyldimethoxysilane, divinyldi-β-methoxyethoxysilane, vinyltriethoxysilane, vinyltris-β-methoxyethoxysilane. or γ-methacryloyloxyprobyltrimethoxysilane, etc., which may be used alone or in combination of two or more, and the monomer (a-
The amount used in 4) is 0.1 to 5% by weight based on the total monomers.
It is appropriate to fall within the range of .

The monomer (a-4), similar to the unsaturated caldic acid (a-3) described above, has a high stability and compatibility with the emulsion copolymer (A) of the lithium silicate (B). Dust is an essential component for the composition of the present invention to exhibit good adhesion to inorganic substrates. On the other hand, if the content exceeds 5% by weight, the effect reaches saturation, which is economically undesirable.

As described above, in the present invention, the synergistic effect of the unsaturated carboxylic acid (a-3) as described above and the monomer (a-4) as mentioned above is exhibited, and the unresolved line layer in the prior art is solved. ,
All of the above-mentioned problems that the present invention aims to solve have been solved for the first time.

In addition to the various monomers listed above, there are other monomers that can be used to increase the polarity of the resulting emulsion copolymer, improve its compatibility with lithium silicate, or improve its adhesion with substrates, top coats, and coating materials. Various vinyl cyanides such as (meth)acrylonitrile, maleic dinitrile or vinylidene cyanide; various glycizol compounds such as glycidyl (meth)acrylate or allyl glycidyl ether; (meth)acrylamide, N-methylol ( Various amide compounds such as meth)acrylamide or dimethylolmethaconic acid amide or their alkoxy compounds; Various hydroxy group-containing compounds such as β-hydroxyethyl (meth)acrylate or β-hydroxypropyl (meth)acrylate; alkylamino(meth) Various amino group-containing compounds such as acrylate, N-alkylaminoalkyl (meth)acrylate or N-alkylaminoalkyl (meth)acrylamide; or various reactive polar group-containing monomers such as N-vinylpyrrolidone, and the resulting vinyl Divinylbenzene, ethylene glycol di(meth) Crosslinkable monomers having two or more unsaturated bonds in one molecule, such as acrylate or glycerin tri(meth)acrylate, can be used, and such monomers can be all over the body,
Preferably, it is used in an amount of 10% by weight or less.

The polymer glass transition temperature of the emulsion copolymer obtained by emulsion copolymerization using the various monomers listed above is determined by the flexibility of the target topcoat paint (topcoat coating material). From the viewpoint of balance between strength and strength,
The particle size of the emulsion copolymer thus obtained is approximately 50°C or less, preferably within the range of -50°C to +50°C. From the standpoint of mixing stability with the lithium silicate (B), which exhibits Considering the compatibility when the mixture with the emulsified dispersion (A) is formed into a film, it is preferable that the particle size is small, and from the viewpoint of balance, the particle size should be about 0. 0
Approximately 7 to about 0.7 microns is appropriate, and preferably,
A range of 0.07 to 0.3 microns is suitable.

The emulsion dispersion (A) of the vinyl copolymer, which is one essential component of the aqueous resin composition for sealers of the present invention, is obtained according to a normal emulsion polymerization method, and therefore cannot be used in such emulsion polymerization. The emulsifier used may be any known and commonly used emulsifier. Among them, only representative examples include various anionic emulsifiers such as alkylbenzene sulfonates, alkyl sulfates, and alkylaryl polyether sulfates. Emulsifiers; various nonionic emulsifiers such as polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers or polyoxyethylene-polyoxyzolopyrene block copolymers; or various cationic emulsifiers such as alkyltrimethylammonium salts or dialkyldimethylammonium salts. These are ionic emulsifiers, etc., and are selected and used as appropriate.

In this case, excessive use of the cationic emulsifier may cause the above-mentioned lithium silicate (B), which is another essential component of the composition of the present invention, to
Special care must be taken as mixing stability with

In addition, along with these emulsifiers, water-soluble oligomers,
Various protective colloids such as water-soluble polymeric compounds such as polyvinyl alcohol or hydroxyethylcellulose can also be used as dispersed stable forms.

If such emulsifiers and protective colloids are used in large amounts, they will not deteriorate the water resistance of the film of the resulting resin composition, and are therefore not preferable, but on the other hand, if they are used in small amounts, This is also undesirable, since it becomes difficult to achieve mixing stability between the resulting emulsion copolymer and lithium silicate.

From this perspective, the amount of emulsifiers and protective colloids to be used is 1 to 10% by weight of the total amount of monomers,
Preferably, a range of 2 to 8% by weight is appropriate.

In addition, only typical examples of polymerization initiators include various water-soluble radical generators such as hydrogen peroxide or persulfate; and/or 2,2'-azobisisobutyronitrile; Benzoyl peroxide (benzoyl peroxide), cumene hydroperoxide (cumene hydroperoxide) 4 L A so-called redox initiator, which is a combination of a reducing agent and a known and commonly used reducing agent, is appropriately selected and used.

Furthermore, in order to adjust and adjust the molecular weight of the emulsion copolymer, known and commonly used chain transfer agents such as various alcohols (catechols) and thiols may be used.

Therefore, the temperature of the emulsion copolymerization carried out in preparing the emulsion dispersion (A) of the vinyl copolymer is as follows:
Generally, the temperature is preferably about 30 to about 90°C, and the copolymerization reaction is preferably carried out in an inert gas such as nitrogen gas.

Next, the lithium silicate (B), which is the other essential component constituting the aqueous resin composition for a sealer of the present invention, will be described. Or alkaline earth metal salts, they behave completely differently. They do not dry well, undergo irreversible reactions, become insoluble in water, become thiaglass-like, and have excellent water resistance. , is a substance that permeates and solidifies an inorganic base material (an inorganic material base material).

The form of the lithium silicate is preferably in the form of a complete aqueous solution; on the other hand, a colloidal form is not preferable because it has poor permeability and adhesion to the substrate.

Furthermore, the content of Li (metallic lithium) in the lithium silicate is determined by the molar ratio of the anhydrous silicic acid component (StO2) to the lithium oxide component (L i 20 ) (SiO
2/Li20) is preferably in the range of 2 to 10.

If this content molar ratio is less than 2, although the resulting resin composition will have good permeability and adhesion to the base material, it will inevitably have poor water resistance.
On the other hand, if it exceeds 10, the resultant resin composition will be inferior in substrate permeability, substrate adhesion, etc., which is not preferable in any case.

A more preferable range of the molar ratio is 3 to 8.
It is.

Therefore, the aqueous resin composition for sealers of the present invention includes emulsified dispersions of vinyl copolymers listed above (
It contains A) and lithium silicate (B) as essential components, but the blending ratio is (A).
)=(B), the solid content weight ratio is 40:60 to 90:1
A value within the range of 0 is appropriate.

If the blending amount of component (A) is less than 40% by weight, the resulting resin composition is inevitably applied to a base material, and then a top coat paint (top coat material) is applied on top of the resulting resin composition. On the other hand, if the amount of component (A) exceeds 90% by weight, the resulting resin composition will inevitably have poor adhesion to the substrate. The case is also unfavorable.

More preferably, the blending ratio indicated by the above-mentioned solid content weight ratio is within the range of 50:50 to 80:20.

In addition, as a method of mixing these two essential components (A) and (B), the emulsified dispersion (A) and lithium silicate (B) may be mixed in advance.
Alternatively, both components (A) and (B) may be mixed immediately before painting, but in consideration of workability, it is recommended to use a pre-mixed product. is desirable.

The thus obtained aqueous resin composition for sealers of the present invention may further contain a film-forming agent, an antifoaming agent, a thickener,
Various known and commonly used additive components such as freeze stabilizers, wetting agents, pigments, and various water-soluble resins may be selected and blended as appropriate, provided, of course, that they do not impair the purpose of the present invention. can.

〔Effect of the invention〕

The aqueous resin composition for sealers of the present invention exhibits excellent adhesion to substrates, regardless of the properties and properties of the substrate itself, whether the substrate is brittle or dense. ,
In addition, it has excellent adhesion to top coat paints (top coat paint materials).

The reason why the composition of the present invention exhibits such excellent physical properties is presumed to be as follows.

That is, the carboxyl group contained in the emulsion copolymer shares some lithium ions with lithium silicate, or
Alternatively, a lithium salt is formed to increase the mixing stability of the emulsion copolymer and lithium silicate.

On the other hand, the alkoxysilyl group contained in the emulsion copolymer and lithium silicate partially react, increasing the compatibility between the emulsion copolymer and lithium silicate, and the alkoxysilyl group and lithium silicate react with each other. Some of the hydroxyl groups present in the inorganic base material (inorganic material base material) are crosslinked, resulting in high adhesion to the base material.

In this way, the highly compatible mixture of emulsion copolymer and lithium silicate not only has excellent storage stability, but also has a high compatibility when coated on an inorganic base material (inorganic substance base material). Lithium silicate, which has particularly excellent permeability to the base material, penetrates deep into the base material and solidifies, and as it approaches the surface of the base material, the proportion of the emulsion copolymer component gradually increases. The combination firmly adheres to the base material and also exhibits a reinforcing effect.

Furthermore, by applying the top coat paint (top coat coating material) to the surface of the base material with an even larger amount of the emulsion copolymer component, top coat adhesion based on this emulsion copolymer can be obtained. being thought about.

In any case, the synergistic effect between the carboxyl group and the alkoxysilyl group in the emulsion copolymer, and the synergistic effect between the emulsion copolymer and lithium silicate, respectively,
It can be said that this is due to the so-called compounding effect.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In the following, all parts and parts are based on weight unless otherwise specified.

Example 1 A stainless steel reaction vessel was charged with 70 parts of deionized water, 1.0 part of sodium lauryl sulfate, and 5 parts of polyoxyethylene nonylphenyl ether, and heated to 75 to 80°C under a nitrogen atmosphere. It was warm.

Furthermore, after adding 0.2 parts of potassium persulfate, 45 parts of styrene, 52.5 parts of n-butyl acrylate, 0.5 parts of vinyltriethoxysilane and 2 parts of acrylic acid were added. A monomer mixture of .1 part of ammonium persulfate was added;
The temperature was maintained at the same temperature for 1 hour to complete the polymerization reaction.

Then, after cooling to 30° C., ammonia water and deionized water were used to adjust the - to 8.5 and the solid content to 50%. Hereinafter, the vinyl copolymer emulsion dispersion (A) thus obtained will be abbreviated as emulsion copolymer (A-1).

After that, 100 parts of this emulsion copolymer (A-1) was added with "lithium silica" 45JI: Nichiwa Kagaku Kogyo (
455 parts of lithium silicate (solid content: 22%, lithium content (SIO2/L120 content molar ratio) = 4.5) diluted three times with water were added and mixed. Hereinafter, this mixture will be abbreviated as aqueous resin composition (I).

Example 2 The composition of the monomer mixture was changed to 50 parts of 2-ethylhexyl acrylate, 45 parts of methyl methacrylate, 1.5 parts of γ-methacryloyloxyzolopyltrimethoxysilane, 3 parts of methacrylic acid, and divinyl 0.5 of benzene
An emulsion copolymer (A-2
) was obtained.

Next, 100 parts of this emulsion copolymer (A-2) was added with "
Lithium silicate 75” [same as above; solid content = 22%,
292 parts of a 3-fold dilution of the lithium content (same as above = 7.5) with water was added and mixed. Hereinafter, this will be abbreviated as aqueous resin composition (II).

Example 3 100 parts of the emulsion copolymer (A-2) was diluted with 20% of lithium silicate 35JI (same as above; solid content = 22%, lithium content (same as above) = 3.5) five times with water.
1 part was added and mixed. Hereinafter, this will be abbreviated as aqueous resin composition (1).

Comparative Example 1 The same procedure was carried out except that the composition of the monomer mixture was changed to 50 parts of 2-ethylhexyl acrylate, 46.5 parts of methyl methacrylate, 3 parts of methacrylic acid, and 0.5 parts of divinylbenzene. In the same manner as in Example 1, a control emulsion copolymer (A'-
1) was obtained.

Next, to 100 parts of this emulsion copolymer (A'-1),
A control aqueous resin composition was obtained by adding 292 parts of "Lithium Silicate 75" diluted to 3 parts. Hereinafter, this will be abbreviated as aqueous resin composition (IV).

Comparative Example 2 The composition of the monomer mixture was changed to 50 parts of 2-ethylhexyl acrylate, 48 parts of methacrylic acid, 1.5 parts of γ-methacryloyloxyglobyltrimethoxysilane, and 0.5 parts of divinylbenzene. Same as Example 1 except that the solid content was 50% and - was 8.5.
A control emulsion copolymer (A'-2) was obtained.

Next, to 100 parts of this emulsion copolymer (A'-2),
A control aqueous resin composition was obtained by adding 292 parts of "Lithium Silicate 75" diluted 3 times with water. Hereinafter, this will be abbreviated as aqueous resin composition (V).

Comparative Example 3 The same procedure as Example 1 was carried out, except that the composition of the monomer mixture was changed to 50 parts of 2-ethylhexyl acrylate and 50 parts of methyl methacrylate, with a solid content of 50%,
A control emulsion copolymer (A'-3) in which - is 8.5
) was obtained.

Next, no matter how an aqueous lithium silicate solution was added to 100 parts of this emulsion copolymer (A'-3), a shock occurred and the mixture instantly glued. Therefore, it could not be used for subsequent performance evaluation tests.

Comparative Example 4 The composition of the monomer mixture was 39 parts of styrene, 52.5 parts of n-butyl acrylate, 2 parts of acrylic acid, 6 parts of methacrylic acid, and 0.5 parts of vinyltriethoxysilane.
A control emulsion copolymer (A'-4) having a solid content of 50% and a voice of 8.5 was obtained in the same manner as in Example 1, except that the solid content was changed to 8.5%.

Next, to 100 parts of this emulsion copolymer (A'-4),
A control aqueous resin composition was obtained by adding 455 parts of "Lithium Silicate 45" diluted 3 times with water.

Hereinafter, this will be abbreviated as aqueous resin composition (VI).

Comparative Example 5 To 100 parts of the emulsion copolymer (A-1), 36 parts of a 3-fold water dilution of "Lithium Silicate 45" was added to obtain a control aqueous resin composition. Hereinafter, this will be abbreviated as an aqueous resin composition (■).

Comparative Example 6 To 100 parts of emulsion copolymer (A-2), 1,591 parts of a 3-fold water dilution of "Lithium Silicate 75" was added to obtain a control aqueous resin composition. Hereinafter, this will be abbreviated as an aqueous resin composition (■).

Table 1 summarizes the monomer compositions of the respective emulsion copolymers, that is, the emulsion dispersions of vinyl copolymers obtained in the above Examples and Comparative Examples.

Separately, Table 2 summarizes the results of a comparative study of the storage stability of each aqueous resin composition obtained in each Example and Comparative Example, as well as the adhesion to the substrate and the top coat. The comparison and study of adhesion properties are summarized in the same table.

That is, first, to evaluate the storage stability of aqueous resin compositions, two aqueous resin compositions prepared according to the composition ratio shown in the table were placed in 200 d sample bottles.
00. ! Collect F, put it in, seal it, and heat it to 50℃ for 1 hour.
After being left for a month, the stability of the product was visually judged.

Furthermore, a comprehensive evaluation was made by taking into consideration changes in the state when each content was returned to room temperature.

Next, various adhesion evaluations were carried out using the respective aqueous resin compositions obtained in the respective Examples and Comparative Examples as shown in the same table, and also the emulsion copolymer (A-1). and,"
A total of 10 samples of Lithium Silicate 45 were diluted with water so that the solid content was 9 to 10%, and the coating amount was 150 to 180,117 m2.
The following types of substrates were coated separately with a brush, and each of the coated materials thus obtained was subjected to a test.
~is.

Fragile base material: Commercially available calcium silicate board for wall materials (specific gravity = 0.92, thickness = 5 cm), hereinafter referred to as "base material A". Normal base material: Ordinary Portland cement. Mortar (water/cement ratio = 80%) prepared with a weight ratio of 1:3 of cement and Toyoura standard sand was 30X30X1
After molding to crn size, JIS A-5
A dense base material, hereinafter abbreviated as "base material B", which is cured until the 28th day of the material age in accordance with 021, and has a specific gravity of 2.08 and a thickness of 5 m.
A commercially available flexible cement gate, hereinafter abbreviated as "base material C", is a embrittled base material...The above base material B is placed in a pressure-tight airtight container, and o. This material was subjected to accelerated aqueous conversion at 20° C. for 14 days in an atmosphere of high pressure carbon dioxide, and is hereinafter abbreviated as “substrate D”.

In addition, evaluation of various adhesion properties was performed as follows.

That is, first of all, as for the adhesion of the sealer to the substrate, each specimen (Tsumashi, solid content diluted with water to 9 to 10%) is applied to various substrates such as those that have been lifted. Each layer was painted with a brush so that the amount was 150 to 1 s o ti/m, and 48°C was applied at 20°C and 60% RH.
Dry for 9 hours.Next, draw 25 Gopan marks at 2m intervals on the surface of each coating film, and make cuts along the Gopan marks until they reach the base material together with the sealer coating. Insert with a cutter knife, apply cellophane tape to the cut, then peel off the cellophane tape at once. Out of the 25 holes, indicate the number of holes where sealer remains on the surface. For example, a sealer labeled r25/25J means that the sealer has completely adhered to the base material and remains.
'' means that the sealer has completely peeled off.

Next, to evaluate the adhesion of the top coat paint, in the same manner as in the case of evaluating the adhesion of the sealer to the base material described above, each coat was applied on the coated film of the sealer coated product that was applied to various base materials and dried. , ■ Commercially available solvent-based acrylic white lacquer paint, ■ Commercially available 7Rat Paint (vinyl acetate free water-based paint for interior use), ■ Commercially available Gloss from India (acrylic-styrene water-based paint), and ■ Commercially available glue paint. Pace of paint (acrylic-styrene sand spray is a paint, and it is before adding aggregate) Four types of paint were applied separately with a brush at a coating rate of 3001/m2. The coating was then dried at 20°C and 60% RH for 7 days, and each coated product thus obtained was then subjected to a test to determine the adhesion of the sealer to the substrate described above. In the same manner as in the case above, a gonomite adhesion test using cellophane tape was conducted.

Of course, those labeled r25/25J mean that the top coat has completely adhered and remains, while rO/25
The designation J means that the top coat has completely peeled off.

The results of these various adhesion tests are summarized in Table 3.

/'/' Thus, the aqueous resin composition for sealers of the present invention has excellent substrate adhesion, regardless of the properties and properties of the substrate.
It has good adhesion to the top coat (top coat coating material), and also has good storage stability due to the good compatibility of both the essential components of the emulsion copolymer and lithium silicate. It has certain industrial effects and advantages.

Claims (1)

[Claims] 1. An emulsified dispersion of a vinyl copolymer having both a carboxyl group and an alkoxysilyl group (A) and lithium silicate (B) in a mixing ratio of (A):(B), An aqueous resin composition for a sealer, comprising a solid content in a weight ratio of 40:60 to 90:10. 2. The emulsified dispersion (A) of a vinyl copolymer having both a carboxylyl group and an alkoxysilyl group as described above,
35 to 99.4% by weight of acrylic acid alkyl ester and/or methacrylic acid alkyl ester (a-1)
and 0 to 64. of styrene or its derivative (a-2).
4% by weight, 0.5 to 5% by weight of α,β-monoethylenically unsaturated carboxylic acid (a-3), at least one polymerizable unsaturated double bond in one molecule, and alkoxysilyl The aqueous resin composition for a sealer according to claim 1, which is obtained by emulsion copolymerizing a monomer mixture consisting of 0.1 to 5% by weight of the compound (a-4) having both groups. .