JPH05247376A - Aqueous undercoating agent for inorganic porous substrate - Google Patents

Abstract

(57) [Summary] [Structure] In an aqueous medium, (a) ethylenically unsaturated carboxylic acid 2
20% by weight (b) selected from the group consisting of alkyl esters of acrylic acid or methacrylic acid having 1 to 10 carbon atoms, vinyl aromatic compounds, vinyl halides, saturated carboxylic acid vinyl esters, acrylonitrile, methacrylonitrile, ethylene, butadiene. Monomer 4
0-98% by weight (c) Other monomer 0-
An inorganic porous substrate in which a copolymer resin obtained by copolymerizing a monomer mixture of 40% by weight is present in an amount of 5% by weight or more solubilized by the addition of an alkali and / or an organic solvent. Water-based primer. [Effect] It is possible to provide a film which is excellent in water resistance, warm water resistance, adhesion to a substrate, and frost damage resistance and which does not cause uneven topcoating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous undercoating agent for an inorganic porous substrate having a water-absorbing fine porous surface, and in particular, an inorganic substrate excellent in water resistance, warm water resistance, frost damage resistance and substrate adhesion. The present invention relates to an aqueous undercoating agent for porous substrates.

[0002]

2. Description of the Related Art Hitherto, as a resin used for an undercoating agent for an inorganic porous substrate, a moisture-curable urethane having a relatively low molecular weight, a solvent type resin and the like have been used. However, in both cases, there is a problem of fire hazard and environmental pollution due to the use of organic solvent, and there is a strong demand for water-based one. As the water-based undercoating agent, various ones having a water-soluble resin or an aqueous resin dispersion as a main component have been studied, but those having a water-soluble resin as a main component have poor water resistance,
In addition, the aqueous resin dispersion liquid is inferior in fluidity because the polymer is present in the form of particles and has a high molecular weight of generally 500,000 to 1,000,000. There are drawbacks such as insufficient material adhesion and the inability to obtain a smooth coating film. In order to improve these drawbacks, so-called microemulsion with a small particle size, addition of a water-soluble resin, etc. Being tried. However, in order to reduce the particle size of the polymer, a large amount of emulsifier must be used, and if a large amount of emulsifier is used, the water resistance of the film will be reduced due to the effect of the emulsifier, and it will not be put to practical use. ..

There is also a method of using an aqueous dispersion of an epoxy resin, but this method has excellent impregnation property for a substrate, but since it uses a curing agent, it becomes a two-part solution, which is complicated to handle and has a long pot life. There are many problems in practical use due to problems and restrictions on the time for overcoating, so an aqueous undercoating agent that is easy to handle and has excellent water resistance, warm water resistance, frost damage resistance, substrate adhesion, etc. is desired. It is rare.

[0004]

DISCLOSURE OF THE INVENTION The present invention intends to provide an aqueous undercoating agent for an inorganic porous substrate capable of giving a film excellent in water resistance, adhesion to a substrate, hot water resistance and frost damage resistance. It is what

[0005]

As a result of various studies to solve the above problems, the inventors of the present invention have added a specific copolymer resin to an aqueous medium by adding an alkali and / or an organic solvent. According to the above, it was found that an aqueous undercoating agent in which a part or all of it was solubilized and existed could achieve the object, and completed the present invention.

That is, the aqueous primer for an inorganic porous substrate of the present invention comprises (a) an ethylenically unsaturated carboxylic acid of 2 to 20% by weight, and (b) an acrylic acid or a methacrylic acid having 1 carbon atom in an aqueous medium. 10 to 10 alkyl ester, vinyl aromatic compound, vinyl halide, saturated carboxylic acid vinyl ester, acrylonitrile, methacrylonitrile, ethylene, monomer selected from the group of 40 to 98% by weight (c) Copolymer resin obtained by copolymerization of a monomer mixture consisting of 0 to 40% by weight of other monomer is present in an amount of 5% by weight or more solubilized by the addition of an alkali and / or an organic solvent. It is characterized by

Among the unsaturated monomers as raw materials for preparing the copolymer resin of the present invention, the (a) ethylenically unsaturated carboxylic acid is a monocarboxylic acid or a polycarboxylic acid. However, it is preferably a mono- or di-olefinically unsaturated carboxylic acid having 3 to 5 carbon atoms. In particular, acrylic acid, methacrylic acid, and itaconic acid are preferable. The amount of ethylenically unsaturated carboxylic acid is 2 to 20% by weight, preferably 5 to 10% by weight, based on the total monomer mixture.
Is. If the amount of the monomer is too small, alkali and / or
Alternatively, sufficient solubilization (solubilization) cannot be performed when an organic solvent is added for solubilization treatment, and sufficient smoothness and adhesion of the film cannot be obtained. On the other hand, if the amount of the monomer is too large, the hydrophilicity of the copolymer resin becomes too high, and the water resistance of the film is lowered, so that the adhesion to the coated object as the undercoating agent is lowered.

As the monomer (b), an alkyl ester of acrylic acid or methacrylic acid having 1 to 10 carbon atoms (for example, methyl, ethyl, isopropyl, n-propyl, n-butyl of acrylic acid or methacrylic acid, Isobutyl, ester such as t-butyl), vinyl aromatic compound (eg styrene), vinyl halide (eg vinyl chloride, vinyl bromide, vinylidene chloride), saturated carboxylic acid vinyl ester (eg vinyl acetate, vinyl propionate), Examples thereof include acrylonitrile, methacrylonitrile, ethylene and butadiene. Particularly preferred monomer (b) is an alkyl ester of acrylic acid or methacrylic acid having 1 to 8 carbon atoms and vinyl acetate. Two or more kinds of these monomers (b) may be contained in the copolymer.

The amount of the monomer (b) is 40 to 98% by weight,
It is preferably in the range of 70 to 94% by weight. When the amount of the monomer (b) is less than the above range, the water resistance tends to decrease, and when the amount of the monomer (b) is more than the above range, the water solubility is decreased. Adhesion of the material will be reduced.

Further, the monomer (c) is other than the above-mentioned monomers (a) and (b), and the amount of the monomer (c) is 0 to 40% by weight, preferably 0. % To 20% by weight, and the monomer (c) is not an essential component. Examples of the monomer (c) include a carbonyl group-containing unsaturated monomer having at least one aldo group or keto group and one polymerizable unsaturated double bond in the molecule, such as acrolein,
Diacetone acrylamide, formyl styrene, 4-
Vinyl alkyl ketones having 7 carbon atoms (eg vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), general formula

[0011]

[Chemical 1]

(Wherein R ¹ is H or CH ₃ , R ² is H or an alkyl group having 1 to ³ carbon atoms, R ³ is an alkyl group having 1 to ³ carbon atoms, and R ⁴ is 1 to 1 carbon atoms. Acrylic (or methacryl) oxyalkylpropenal represented by 4 alkyl groups), diacetone acrylate, acetonyl acrylate, diacetone methacrylate, 2-
Hydroxypropyl acrylate acetyl acetate,
Butanediol-1,4-acrylate acetylacetate, etc., mono-olefinically unsaturated carboxylic acid amides (eg acrylic acid amide, methacrylic acid amide, itaconic acid amide, etc.), mono-olefinically unsaturated carboxylic acid amide N-alkyl and / or Or an N-alkylol derivative (for example, N-methylacrylamide, N-isobutylacrylamide, N-methylolacrylamide, N
-Methylol methacrylamide, N-ethoxymethyl acrylamide), monoolefinic unsaturated sulfonic acid (for example, vinyl sulfonic acid, methyl acrylamido propane sulfonic acid, etc.), hydroxyethyl acrylate, hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate and the like. .. Two or more kinds of these monomers (c) may be contained in the copolymer.

Copolymerization for producing a copolymer resin using each of the above-mentioned monomer mixtures (a) to (c) is carried out by solution polymerization or emulsion polymerization. The solvent used for the solution polymerization is not particularly limited, but a water-soluble or hydrophilic solvent is preferable from the viewpoint of compatibility with the produced copolymer resin and water. Specific examples thereof include monoalcohols having 1 to 4 carbon atoms, such as methyl alcohol,
Ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol and t-butyl alcohol; ethylene glycol and derivatives thereof, such as ethylene glycol monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether; diethylene glycol and derivatives thereof, Examples thereof include diethylene glycol monomethyl ether, the same monoethyl ether, the same monopropyl ether, the same monobutyl ether; and 1,4-dioxane and water. One type of these solvents may be used, or two or more types may be appropriately used in combination. As the solvent, those having a boiling point of 200 ° C. or less are generally preferable from the viewpoint of distillation after the polymerization or drying speed.

The polymerization initiator for solution polymerization is preferably oil-soluble. Specific examples thereof include azo initiators such as azobisisobutyronitrile and azobisvaleronitrile; organic peroxide initiators such as benzoyl peroxide, lauroyl peroxide and t-butyl peroxide; and other peroxides. Inorganic peroxide type initiators such as hydrogen and ammonium persulfate can also be used. These initiators may be used alone or in combination of two or more as appropriate. Further, a reducing agent such as Rongalit, L-ascorbic acid, or an organic amine may be used in combination with these initiators and used as a redox initiator.

The copolymer resin can also be produced by emulsion polymerization. For the emulsion polymerization, a method in which an emulsifier is used to carry out the polymerization with a water-soluble polymerization initiator, or a soap-free polymerization is used. A method of carrying out polymerization or the like is used. Examples of the emulsifier include various anionic, cationic and nonionic emulsifiers, and further polymeric emulsifiers. A particularly preferred emulsifier is a carbonyl group-containing polymer emulsifier described in JP-A-64-48801, which is a publication of a patent application relating to the invention of the present inventors (a part).

The polymerization initiator used in emulsion polymerization is preferably an inorganic peroxide such as potassium persulfate, ammonium persulfate or hydrogen peroxide. These inorganic peroxides include
You may use together with the reducing agent as mentioned above as a redox initiator. Various methods can be used as the method for supplying the monomer in the emulsion polymerization. For example, various methods such as a batch charging method, a monomer addition method and an emulsion addition method can be used. In addition, a seed polymerization method in which the composition of the added monomer is sequentially changed, or a power fiber
A depolymerization method or the like can also be used, and when such a method is used, the copolymerization composition between the central portion of the produced copolymer resin particles and the outside can be changed and the degree of solubilization can be adjusted.

A chain transfer agent is preferably used in the emulsion polymerization. This is because the copolymer resin obtained by emulsion polymerization generally has a high molecular weight, so that when it is solubilized in water by the addition of an alkali and / or an organic solvent, it is difficult to achieve sufficient solubilization, but chain transfer This is because the use of the agent can reduce the molecular weight of the produced copolymer resin and facilitate the solubilization. Examples of the chain transfer agent include various mercaptans, α
-Methylstyrene, alkyl halides, alcohols and the like. The amount used is 0.03 to 5% by weight based on all the monomers.

The copolymer resin prepared by the solution polymerization or emulsion polymerization described in detail above should have a solubilization rate of 5% by weight or more by the addition of an alkali and / or an organic solvent. Solubilized, but solubilized (ie, addition of alkali and / or organic solvent)
May be before starting the copolymerization for producing the copolymer resin or at the time of the copolymerization. In any case, the "solubilization rate" described in the present specification means the solubilization rate measured by the following method.

Solubilization treatment was carried out under exactly the same conditions as the actual solubilization treatment to prepare a copolymer resin, and the obtained copolymer resin was diluted with water to a nonvolatile content of 15% by weight. After that, the diluted solution is subjected to centrifugal acceleration of 1.8 × 10 ⁵ g.
When the non-volatile content in the obtained supernatant is measured as w parts by weight, and the non-volatile content in the above-mentioned diluent used for centrifugation is measured as W parts by weight. The solubilization rate represented by the following formula. Solubilization rate = w / W x 100 (% by weight)

Therefore, for example, in the case where the alkali and / or organic solvent is added to the polymerization system before the polymerization for producing the copolymer resin or during the polymerization, the copolymerization is performed. If the solubilization rate of the polymerization product containing the produced copolymer resin obtained by the polymerization is already 5% by weight or more, the addition of an alkali and / or an organic solvent for the solubilization treatment is newly performed. Does not have to be performed.

The alkali used for the solubilization treatment is an inorganic water-soluble alkali, such as sodium hydroxide or potassium hydroxide; or an inorganic salt which shows alkalinity when dissolved in water, such as sodium hydrogen carbonate or pyrophosphate. Sodium and the like; other examples include aqueous ammonia and organic amines. Addition of alkali is as described above.
It does not necessarily have to be after the formation of the copolymer, and in some cases, (a) the ethylenically unsaturated carboxylic acid before copolymerization for forming the copolymer resin is neutralized by adding an alkali, Copolymerization may be performed. Also,
The addition of the alkali in the case of solution polymerization may be performed in the presence of the solvent used for the copolymerization, or the alkali is made into an aqueous solution and added partially or completely to the copolymer resin after the solvent is distilled off. It may be solubilized in water. The amount of alkali used may be an amount that completely neutralizes the carboxyl groups in the copolymer resin or an amount that partially neutralizes the carboxyl groups.

The organic solvent used for the solubilization treatment may be supplementarily added when it cannot be sufficiently solubilized in water only by adding an alkali, or may be solubilized by adding only an organic solvent. Further, in the case of producing a copolymer resin by solution polymerization, when the organic solvent used as the polymerization solvent can serve as an organic solvent for solubilization as it is, the addition of the organic solvent is newly added. May not be required, and in some cases, an organic solvent different from the organic solvent used as the polymerization solvent may be added. Examples of the organic solvent used include the same ones as described above as the solvent used for the solution polymerization. Particularly preferred organic solvents are texanol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether and their acetates, benzyl alcohol, butyl carbitol acetate, 2,2,2.
4-trimethyl-1,3-pentanediol and the like can be mentioned.

In order to improve the water resistance of the copolymer resin, at least one aldo group in the molecule exemplified as the other monomer of the above (c) as a constituent monomer of the copolymer resin or Copolymerization is carried out using a carbonyl group-containing unsaturated monomer having a keto group and one polymerizable unsaturated double bond, and then a hydrazine derivative having at least two hydrazino groups in the molecule is added. Is effective.

The carbonyl group-containing unsaturated monomer is preferably used in a proportion of 0.5 to 30% by weight, more preferably 1 to 20% by weight in the total monomer mixture. If the amount of the monomer is too small, the content of the aldehyde group or keto group in the copolymer resin is too small, and even if a hydrazine derivative is added, sufficient water resistance and solvent resistance can be expected to improve. Absent. On the other hand, if the amount of the monomer is too large, the alkali resistance, weather resistance, etc. of the film tend to decrease.

The hydrazine having at least two hydrazino groups in the molecule is, for example, 2 to 10,
In particular dicarboxylic acid dihydrazides having 4 to 6 carbon atoms (eg oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide,
Adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide), aliphatic water-soluble dihydrazine having 2 to 4 carbon atoms (for example, ethylene-1,2-dihydrazine, propylene-1) , 3-dihydrazine, butylene-1,4-dihydrazine, etc.).

Further, the general formula,

[0027]

[Chemical 2]

(Wherein, X is a hydrogen atom or a carboxyl group, Y is a hydrogen atom or a methyl group, A is each unit of acrylamide, methacrylamide, acrylic ester, methacrylic ester or maleic anhydride. , B is a unit of a monomer copolymerizable with acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, or maleic anhydride, and k, m, and n are 2 mol% ≦ k ≦ of the following formulas. A polymer represented by 100 mol% 0 mol% ≦ (m + n) ≦ 98 mol% (k + m + n) = 100 mol% is also used as the hydrazine derivative. Such polymers are described in detail, for example, in JP-A-55-6535.

The blending ratio of the hydrazine derivative is such that the ratio of the carbonyl group and the hydrazino group contained in the copolymer resin and other additives (specifically, the resin aqueous dispersion described below) is
(> C = O) / ( - NHNH 2) is preferably in the molar ratio 0.2 to 5.0, more preferably the ratio becomes 0.3 to 2.0. If the proportion of hydrazine derivative is too low,
Since cross-linking between resins is not sufficiently performed, improvement in water resistance cannot be expected, and even if the ratio is too large, not only the effect of improving water resistance commensurate with it cannot be obtained, but also the film is formed. It is opaque and easily fragile.

In the present invention, another resin aqueous dispersion may be added for the purpose of improving the water resistance and alkali resistance of the film, adjusting the viscosity, etc., and the resin aqueous dispersion is obtained by synthesis. The synthetic resin emulsion obtained by emulsion polymerization is preferable although it is an aqueous emulsion of a synthetic resin to be used or a wide variety of natural resins. The synthetic resin aqueous dispersion obtained by emulsion polymerization is, as is generally known, an emulsifier, a reactive emulsifier or a protective colloid as a dispersant, and an unsaturated monomer in water using a water-soluble initiator. It can be obtained by (co) polymerization. Examples of the unsaturated monomer include acrylic acid,
For the purpose of methacrylic acid, various esters thereof, vinyl aromatic compounds such as styrene, vinyl halides, acrylonitrile, methacrylonitrile, saturated carboxylic acid vinyl esters, conjugated dienes, unsaturated hydrocarbons such as ethylene and propylene. A copolymer resin aqueous dispersion, which is appropriately combined and used, is usually preferably used.

In addition to the resin aqueous dispersion obtained by emulsion polymerization, there are, for example, polyurethane resin emulsion, alkyd resin emulsion, bisphenol type epoxy resin emulsion, etc., and these resin aqueous emulsions should be used as the resin aqueous dispersion. You can

A particularly preferred aqueous resin dispersion is 0.5 to 20% by weight of the carbonyl group-containing unsaturated monomer exemplified as the component (c); the ethylenically unsaturated carboxylic acid exemplified as the component (a). Acid 0 to 10% by weight; of acrylic acid or methacrylic acid alkyl ester having 1 to 10 carbon atoms exemplified as the component (b), acrylonitrile, methacrylonitrile, vinyl aromatic compound, vinyl halide, saturated carboxylic acid By emulsion polymerization of a monomer mixture of 55 to 99.5% by weight of at least one unsaturated monomer selected from vinyl ester, ethylene and butadiene; and 0 to 15% by weight of other monomers other than them. It is an aqueous dispersion of the resulting copolymer resin.

The carbonyl group-containing unsaturated monomer used in this case is the same as the carbonyl group-containing unsaturated monomer exemplified as the preferable component (c) in the case of the above-mentioned copolymer resin. A copolymer resin obtained by copolymerizing an aqueous resin dispersion containing the unsaturated monomer as a constituent with a carbonyl group-containing unsaturated monomer as a constituent unit of the copolymer resin to be solubilized. The aqueous undercoating agent of the present invention using is a complex cross-linking bond between the copolymer resins, between the copolymer resins constituting the resin aqueous dispersion, and between the two resins through the hydrazine derivative. Therefore, the physical properties of the crosslinked film are further improved.

The mixing ratio of the copolymer resin in the present invention and the resin aqueous dispersion may be arbitrary, but is preferably 10/0 to 2/8, more preferably 10 in terms of solid content weight ratio.
/ 0 to 3/7. If the proportion of the copolymer resin is too low, the film may be formed on the surface layer of the base material, and the effect of improving the adhesion, smoothness and gloss of the film to the base material may not be sufficiently obtained.

The method of blending the copolymer resin and the resin aqueous dispersion is not particularly limited. For example, to an organic solvent solution containing a copolymer resin obtained by solution polymerization, after adding an alkaline solution, the solvent may be distilled off, and then the resin aqueous dispersion may be added, or the solvent may be distilled off. May be added without. When the copolymer resin is obtained by emulsion polymerization, the aqueous resin dispersion may be added after the alkali and / or organic solvent is added to the aqueous dispersion of the copolymer resin to solubilize it. .. Alternatively, the alkali resin and / or the organic solvent may be added after mixing the copolymer resin and the resin aqueous dispersion.

In the present invention, the solubilization treatment of the copolymer resin prepared by solution polymerization or emulsion polymerization when adding the resin aqueous dispersion or the hydrazine derivative is carried out by adding the resin aqueous dispersion and the copolymer resin to the copolymer resin. It may be before mixing the hydrazine derivative, or during the mixing, or even after the mixing.

Further, in the present invention, in the system using the copolymer resin obtained by polymerizing using the carbonyl group-containing unsaturated monomer as the component (c) and the hydrazine derivative, the reaction of the carbonyl group and the hydrazino group Progresses with drying and film formation, but gelation is likely to occur because it is slightly performed in the aqueous phase. In order to prevent this, it is preferable to add a low molecular weight compound (aldehyde or ketone) having a boiling point of 200 ° C. or less, which contains a carbonyl group based on an aldo group or a keto group. The boiling point is preferably 120 ° C. or lower, and more preferably 100 ° C. or lower.

This is because under the condition that a large amount of water is present, such as the film before storage and before drying of the water-based primer of the present invention,
The low molecular weight aldehydes and ketones compounded react with the hydrazino group of the hydrazine derivative and block the hydrazino group, so the crosslinking reaction between the polymers is effectively prevented and the gelation of the resin is stopped. It is considered that the gelation time can be extended.

Specific examples of the aldehydes or ketones include formaldehyde (boiling point-21 ° C.),
β-hydroxyethyl methyl ketone (at 182 ° C), acetaldehyde (at 21 ° C), propionaldehyde (at 49 ° C), butyraldehyde (at 75 ° C), valeraldehyde (at 103 ° C), isovaleraldehyde (at 93 ° C). ), Pivalinaldehyde (at 75 ° C), capronaldehyde (at 131 ° C), heptaldehyde (at 15 ° C)
3 ° C), glyoxal (51 ° C in the same), succindialdehyde (170 ° C in the same), acrolein (52 ° C in the same), propiolaldehyde (60 ° C in the same), crotonaldehyde (105 ° C in the same), acetone (56 ° C in the same) , Ethyl methyl ketone (at 80 ℃), methyl propyl ketone (at 10
2 ° C.), isopropyl methyl ketone (95 ° C. same), butyl methyl ketone (127 ° C. same), isobutyl methyl ketone (117 ° C. same), pinacolone (106 ° C. same), diethyl ketone (102 ° C. same), butyron (144 same) C.), diisopropyl ketone (124.degree. C.), methyl vinyl ketone (81.degree. C.), acetoin (148.degree. C.) and the like. These aldehydes or ketones may be used alone or in combination of two or more.

A film forming aid, a pigment, a filler, a wetting agent and the like can be added to the aqueous undercoating agent of the present invention.

[0041]

EXAMPLES Hereinafter, copolymer resin preparation examples, resin aqueous dispersion preparation examples, examples and comparative examples will be described in detail. The "parts" and "%" described in these examples are on a weight basis. Preparation Example 1 of Copolymer Resin Temperature controller, anchor type stirrer, reflux condenser, supply container,
After the inside of the reaction vessel equipped with a thermometer and a nitrogen introducing tube was replaced with nitrogen, 130 parts of ethylene glycol monobutyl ether was charged.

Separately, the following composition was prepared as a feed. Feed material Ethylene glycol monobutyl ether 110 parts Acrylic acid 5 parts Diacetone acrylamide 5 parts 2-Hydroxyethyl acrylate 5 parts Butyl acrylate 25 parts Methyl methacrylate 60 parts Benzoyl peroxide 3 parts Next, the reaction vessel is kept at 80 ° C. However, the above feed was continuously fed thereto in small portions over 3 hours.
After the end of the supply, the same temperature was maintained for 2 hours to complete the polymerization.

This solution was concentrated by distillation until the nonvolatile content became 60%, and then 23 g of a 10% aqueous sodium hydroxide solution was added to obtain an ethylene glycol monobutyl ether solution of a copolymer resin having a nonvolatile content of 54%. Then, 30 parts of a mixture of ethylene glycol monobutyl ether and water was distilled off from the obtained solution using a rotary evaporator, and then water was added to the non-volatile part 20%, p.
A copolymer resin solution of H9 was obtained.

Copolymer Resin Preparation Examples 2 and 3 The same procedure as in Preparation Example 1 was carried out except that the monomer composition of the feed and the polymerization solvent were changed as shown in Table 1.

Copolymer Resin Preparation Example 4 Into the same reaction vessel as used in Preparation Example 1 above, the following materials were charged. Water 50 parts Ethylene oxide 20 mol addition p-nonylphenol sulfuric acid half ester sodium salt of 35% aqueous solution (referred to as "anionic emulsifier A") 2 parts Ethylene oxide 25 mol addition p-nonylphenol (referred to as "nonionic emulsifier B") The following mixture was prepared as a feed I separately from 1 part of 20% aqueous solution of

Feed I Water 50 parts 35% aqueous solution of the above anionic emulsifier A 4 parts 20% aqueous solution of the above nonionic emulsifier B 2 parts Methyl methacrylate 55 parts Butyl acrylate 30 parts Diacetone acrylamide 5 parts Acrylic Acid 5 parts Methacrylic acid 5 parts t-Dodecyl mercaptan 0.7 parts Separately, an aqueous solution prepared by dissolving 0.7 parts of potassium persulfate in 20 parts of water was prepared as a feed II.

After purging the inside of the reaction vessel with nitrogen gas, 10% of the feed I was added to the charge, and the mixture was heated to 90 ° C. Then, 10% of the feed II was injected into the reaction vessel, and then the remaining feeds I and II were fed in parallel little by little over 3.5 hours. After the end of the supply, the temperature was kept at 90 ° C. for 1.5 hours to complete the emulsion polymerization.

The aqueous resin dispersion obtained as described above was diluted with water so that the nonvolatile content was 20%, and then 2
A 5% aqueous ammonia solution was added to adjust the pH to 9.

Copolymer Resin Preparation Examples 5 to 8 The same procedure as in Preparation Example 4 was conducted except that the monomer composition of the feed and the chain transfer agent present in the polymerization system were changed as shown in Table 2.

Copolymer Resin Preparation Example 9 The following was charged into a reaction vessel similar to that used in Preparation Example 1 above. Water 50 parts Na lauryl sulfonate 2 parts 35% aqueous solution of anionic emulsifier A 3 parts Separately, the following mixture was prepared as a feed I.

Water 50 parts Na lauryl sulfonate 1 part 35% aqueous solution of the above anionic emulsifier A 2 parts Styrene 50 parts Butyl acrylate 30 parts Acrylic acid 5 parts Methacrylic acid 5 parts Diacetone acrylamide 10 parts t-dodecyl mercaptan 0.1. 5 parts Separately, as a feed II, an aqueous solution prepared by dissolving 0.5 parts of potassium persulfate in 20 parts of water was prepared.

After purging the inside of the reaction vessel with nitrogen gas, 10% of the feed I was added to the charge, and the mixture was heated to 90 ° C. Then, 10% of the feed II was injected into the reaction vessel, and then the remaining feeds I and II were fed in parallel little by little over 3.5 hours. After the end of the supply, the temperature was kept at 90 ° C. for 1.5 hours to complete the emulsion polymerization.

The resin aqueous dispersion obtained as described above was diluted with water so that the nonvolatile content was 20%, and then 1
Add 0% sodium hydroxide to a pH of 9,
Furthermore, 3 parts of ethylene glycol monobutyl ether was added.

Copolymer Resin Preparation Examples 10 to 12 The same procedure as in Preparation Example 9 was conducted except that the monomer composition of the feed was changed as shown in Tables 2 and 3.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

Resin Aqueous Dispersion Preparation Example A The following was charged into a reaction vessel similar to that used in Preparation Example 1 above. Water 200 parts 35% aqueous solution of anionic emulsifier A 5 parts 20% aqueous solution of nonionic emulsifier B 20 parts Separately, the following mixture was prepared as a feed I.

Feed I Water 200 parts 35% aqueous solution of the above anionic emulsifier A 25 parts Acrylic acid 10 parts Diacetone acrylamide 23 parts Butyl acrylate 198 parts Styrene 235 parts Separately, as a supply II, in 85 parts water A solution having 2.5 parts of potassium persulfate dissolved therein was prepared.

After purging the reaction vessel with nitrogen gas, 10% of feed I was added to the charge and the mixture was heated to 90.degree. Then, 10% of the feed II was injected into the reaction vessel, and the remaining feeds I and II were fed into the reaction vessel in small amounts uniformly in parallel over 3 to 3.5 hours. After the end of the supply, the temperature was raised to 90 ° C. and the temperature was kept for another 1.5 hours to carry out emulsion polymerization. The produced resin aqueous dispersion had a nonvolatile content of 47% and a minimum film-forming temperature of 20 ° C.

Aqueous Resin Dispersion Preparation Examples B and C The monomer composition of the feed I in the above Preparation Example A was changed to that shown in Table 4, and the emulsification was performed in the same manner as in Preparation Example A. Polymerization was performed to obtain a copolymer resin aqueous dispersion.

[0062]

[Table 4]

Example 1 70 parts of an ethylene glycol monobutyl ether solution having a nonvolatile content of 20% obtained in Preparation Example 1 of a copolymer resin, and an aqueous dispersion 3 of a copolymer resin obtained in Preparation Example A of a resin aqueous dispersion.
0 parts and 20% aqueous solution of adipic dihydrazide 20
The parts were mixed. The dried film of the obtained water-based undercoating agent was tested for adhesion, uneven topcoating, water resistance, warm water resistance and frost damage resistance by the following test methods, and the evaluation results are shown in Table 5.
It was as shown in.

As a test piece, a 5 cm × 10 cm calcium silicate plate was applied such that the coating amount after drying was 20 g / m ^2, and dried at 100 ° C. for 10 minutes to form a film.

Adhesion: The test piece was cut into 5 × 5 crosses with a cutter knife at intervals of 3 mm, a polyester adhesive tape was pressure-bonded thereto, and then peeled off to examine the remaining state of the coating film. ⊚: The coating film does not peel at all ◯: The coating film peels slightly Δ: The coating film partially peels ×: The coating film completely peels

Topcoat unevenness: As a topcoat paint on a test piece, a paint obtained by blending as follows was applied so that the film thickness after drying was 50 μm, and dried at 100 ° C. for 10 minutes to form a film. The appearance was visually evaluated.

Topcoat paint composition Water 64.6 parts Demol EP (manufactured by Kao) 20 parts Nopco 8034 (manufactured by San Nopco) 0.3 parts Titanium oxide (rutile type) 54.0 parts Kaolin 6.0 parts Acronal YJ- 2770D (manufactured by Mitsubishi Yuka Birdish Co., Ltd.) 146.7 parts Texanol (manufactured by Eastman Kodak Company) 9.5 parts 5% -Adecan UH-420 (manufactured by Asahi Denka Co.) 1.0 part

◎: No unevenness ○: Some unevenness △: Unevenness ×: Lifting

Water resistance: The test piece was immersed in water at 20 ° C. for 5 days and then dried at room temperature for 2 days, and the same evaluation as the adhesion was performed.

Warm water resistance: The test piece was immersed in warm water at 40 ° C. for 5 days, dried at room temperature for 2 days, and the adhesion was examined by the same method as above.

Freezing damage resistance: immersion in water at 10 ° C. for 2 hours → -2
Adhesion was examined by the same method as above, after 200 cycles of 1 cycle of freezing in the air at 0 ° C. for 2 hours were carried out, followed by drying at room temperature for 2 days.

Examples 2 to 13 and Comparative Examples 1 to 4 The kinds and amounts of the copolymer resin, the resin aqueous dispersion and the hydrazine derivative were changed as shown in Tables 5 to 8 and the formulation was changed to ethylene glycol mono. Aqueous undercoating agents were prepared in the same manner as in Example 1 except that butyl ether was blended in the respective amounts, and the film physical properties were tested in the same manner.

Tables 5 to 8 show the composition ratios (parts) and the like of the aqueous undercoating agents obtained in each of these Examples and Comparative Examples, and the test results of the film physical properties.

[0074]

[Table 5]

[0075]

[Table 6]

[0076]

[Table 7]

[0077]

[Table 8]

Note in Tables 5 to 8 * 1 ... Adipic acid dihydrazide * 2 ... Maleic acid dihydrazide As is clear from Tables 5 to 8, the undercoating agents of Examples are compared with those of Comparative Examples. , Adhesion, uneven topcoating, water resistance, warm water resistance, and frost damage resistance are comprehensively judged and excellent.

[0079]

The water-based undercoating agent of the present invention is excellent in water resistance, warm water resistance, adhesion to a substrate and frost damage resistance, and can give an excellent film which does not cause unevenness of the top coating.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C09D 127/06 PFE 9166-4J 131/02 PFV 6904-4J 133/06 PGC 7921-4J 133/18 PGC 7921-4J 147/00 PGN 8218-4J (72) Inventor Yoshinori Kato 1000 Kawajiri-cho, Yokkaichi-shi, Mie Prefecture In Mitsubishi Yuka Birdishe Co., Ltd. (72) Ryutaro Hayashi 1000 Kawajiri-cho, Yokkaichi-shi, Mie Mitsubishi Oil In Kadashi Birdishe Co., Ltd.

Claims (3)

[Claims] 1. In an aqueous medium, (a) ethylenically unsaturated carboxylic acid 2 to 20 wt% (b) acrylic acid or methacrylic acid alkyl ester having 1 to 10 carbon atoms, vinyl aromatic compound, halogenated Monomer selected from the group consisting of vinyl, saturated carboxylic acid vinyl ester, acrylonitrile, methacrylonitrile, ethylene, and butadiene 40 to 98% by weight (c) Other monomer 0 to 40% by weight The copolymer resin obtained by the copolymerization of the body mixture is present in an amount of 5% by weight or more thereof solubilized by the addition of an alkali and / or an organic solvent. Undercoat. 2. The (c) other monomer in the monomer mixture contains at least one carbonyl group based on an aldo group or keto group in the molecule, and has one polymerizable double bond. A carbonyl group-containing unsaturated monomer having a bond, the amount of which is 0.5 to 30% by weight, and the primer is a hydrazine derivative having at least two hydrazino groups in the molecule. The water-based undercoating agent for an inorganic porous substrate according to claim 1, which is mixed. 3. The ratio of the aldo group or keto group contained in the copolymer resin to the hydrazino group contained in the hydrazine derivative is 0.2 in terms of (> C═O) / (— NHNH ₂ ) molar ratio.
It is -5.0, The water-based undercoating agent for inorganic porous substrates of Claim 2.