JP5219136B2 - Water-based coating material - Google Patents

Description

  The present invention relates to a novel aqueous coating material.

  2. Description of the Related Art In recent years, coating materials used for construction and civil engineering structures are being changed from a solvent type using an organic solvent as a medium to an aqueous solution using water as a solvent. This is carried out for the purpose of reducing the health hazards of painters and residents, and for the purpose of reducing air pollution.

  In connection with this, the request | requirement of the performance improvement with respect to an aqueous coating material is also increasing. In order to meet such demands, functional groups having crosslinkability are introduced into the binder of the water-based coating material to provide weather resistance, water resistance, warm water resistance, alkali resistance, acid resistance, solvent resistance, and chemical resistance. The technique of improving durability, such as these, is taken. For example, JP-A-7-62188 (Patent Document 1) discloses an aqueous dispersion resin composition comprising an acrylic copolymer aqueous resin emulsion having a ketone group or an aldehyde group introduced therein and a water-soluble polyhydrazide compound. Have been described. Japanese Patent Application Laid-Open No. 11-152439 (Patent Document 2) discloses an emulsion copolymerization of a monomer mixture comprising a vinyl polymerizable monomer, a carboxyl group-containing vinyl monomer, and an unsaturated group-containing high molecular weight emulsifier. An aqueous coating composition comprising a copolymer aqueous dispersion obtained in this manner and a non-vinyl polymerizable silane coupling agent is described.

  Such a cross-linked water-based coating material can improve the durability compared with the case where a non-cross-linked water-dispersible resin is used as a binder, and can obtain a relatively advantageous effect in terms of drying of the film. Can do. However, in the case of the above-described cross-linking type aqueous coating material, even if the coating is apparently dried, it may still be insufficient from the viewpoint of coating curability. For example, after the coating is formed, it takes a considerable time until the coating reaches final curing, and stickiness may remain on the coating surface for a long time. Alternatively, since the coating itself is insufficiently cured, it may be difficult to obtain satisfactory performance in terms of wear resistance and the like.

JP-A-7-62188 Japanese Patent Laid-Open No. 11-152439

  The present invention has been made in view of the above-described problems, and has an excellent durability in the formed film, and can exhibit excellent performance in terms of curability, hardness, wear resistance, and the like. It is to obtain a covering material.

  In order to solve such problems, the present inventors, as a result of intensive studies, have developed a specific water-dispersible resin (A), an epoxy group-containing compound (B), a basic compound (C), and an amino group-containing alkoxy. The inventors have conceived an aqueous coating material containing a silane compound (D) as an essential component, and have completed the present invention.

That is, the present invention relates to the following aqueous coating materials.
1. The polymer of the monomer group containing the (meth) acrylic acid alkyl ester and the carboxyl group-containing monomer is used as a resin component, the ratio of the carboxyl group-containing monomer in the monomer group is 0.2 to 20% by weight, and the glass transition temperature is A water dispersible resin (A) having a temperature of 0 to 80 ° C.,
An epoxy group-containing compound (B) having two or more epoxy groups in one molecule;
A basic compound (C), and an amino group-containing alkoxysilane compound (D),
The mixing ratio of each component is 0.1 to 50 parts by weight of the epoxy group-containing compound (B) and 0.01% of the basic compound (C) with respect to 100 parts by weight of the solid content of the water-dispersible resin (A). 10 to 10 parts by weight and 0.1 to 50 parts by weight of the amino group-containing alkoxysilane compound (D).
2. 1. It consists of a main agent containing the water-dispersible resin (A), the epoxy group-containing compound (B), and the basic compound (C), and a curing agent containing the amino group-containing alkoxysilane compound (D). The aqueous coating material as described.

  According to the aqueous coating material of the present invention, in addition to durability such as weather resistance, water resistance, warm water resistance, alkali resistance, acid resistance, solvent resistance, chemical resistance, etc., in terms of curability, hardness, wear resistance, etc. A film having excellent performance can be formed.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The aqueous coating material of the present invention comprises a specific water-dispersible resin (A), an epoxy group-containing compound (B), a basic compound (C), and an amino group-containing alkoxysilane compound (D) as essential components. . Among these, the water-dispersible resin (A) (hereinafter also referred to as “component (A)”) is a resin component of a polymer of a monomer group including a (meth) acrylic acid alkyl ester and a carboxyl group-containing monomer. is there.

Examples of the (meth) acrylic acid ester in the component (A) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl. (Meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) a Relate and the like. In the present invention, the acrylic acid alkyl ester and the methacrylic acid alkyl ester are collectively referred to as (meth) acrylic acid alkyl ester.
The proportion of (meth) acrylic acid ester in the whole monomer group is usually about 60 to 99.8% by weight, preferably about 70 to 99.5% by weight.

As said (meth) acrylic acid ester, it is desirable to contain the (meth) acrylic-acid alkylester whose alkyl group is C1-C6. In particular, one or more kinds of (meth) acrylic acid alkyl esters having 1 to 2 carbon atoms in the alkyl group and one or more kinds of (meth) acrylic acid alkyl esters having 3 to 6 carbon atoms in the alkyl group are combined. It is desirable to use. In the component (A), the proportion of the alkyl group having 7 or more carbon atoms of the alkyl group in the monomer group is 20% by weight or less (preferably 10% by weight or less, more preferably 5% by weight). The following is desirable. In the monomer group of the component (A), an embodiment that does not contain a (meth) acrylic acid ester in which the alkyl group has 7 or more carbon atoms is also suitable.
Thus, by selecting and using (meth) acrylic acid ester, advantageous effects can be obtained in curability, hardness, wear resistance, durability, and the like.

  Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid, maleic acid or a monoalkyl ester thereof, itaconic acid or a monoalkyl ester thereof, fumaric acid or a monoalkyl ester thereof. Among these, at least one selected from acrylic acid and methacrylic acid is particularly preferable. The ratio of the carboxyl group-containing monomer is usually 0.2 to 20% by weight, preferably 0.5 to 10% by weight, based on the entire monomer group constituting the component (A). Such a carboxyl group plays a role of enhancing curability, hardness, wear resistance, durability, and the like by a crosslinking reaction with the component (B) described later. When the ratio of the carboxyl group-containing monomer is too low, it is difficult to obtain the effect of improving physical properties by the crosslinking reaction. When the ratio of the carboxyl group-containing monomer is too higher than 20% by weight, it is difficult to ensure sufficient physical properties in terms of durability. In addition, the viscosity of the coating material tends to increase, and there is a risk that the coating workability, finishing performance, and the like will be hindered.

  In the component (A), monomers other than those described above (hereinafter referred to as “other monomers”) can be used. Examples of other monomers include N-methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, N- (2-dimethylaminoethyl) acrylamide, and N- (2-dimethylaminoethyl) methacrylamide. Amino group-containing monomers, hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, epoxy group-containing monomers such as glycidyl (meth) acrylate, diglycidyl (meth) acrylate, allyl glycidyl ether, (meta ) Amide group-containing monomers such as acrylamide, acrolein, diacetone (meth) acrylamide, carbonyl group-containing monomers such as vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, vinyl trimethoxy Alkoxysilyl group-containing monomers such as silane, vinyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane; Examples thereof include aromatic monomers such as styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, and divinylbenzene.

  The proportion of other monomers in the entire monomer group is usually about 0 to 40% by weight, preferably about 0 to 30% by weight. Among the above monomers, for aromatic monomers, the proportion of the entire monomer group is 10% by weight or less (preferably 5% by weight or less, more preferably 3% by weight) from the viewpoint of improving durability, curability, abrasion resistance and the like. % Or less) is desirable.

  (A) The glass transition temperature (henceforth "Tg") of a component is 0-80 degreeC, Preferably it is 10-60 degreeC, More preferably, it is 20-50 degreeC. When Tg is lower than 0 ° C., the hardness of the film becomes insufficient, and it is difficult to obtain satisfactory physical properties in terms of wear resistance and the like. When Tg is higher than 80 ° C., it is difficult to ensure stable performance in film forming property, crack resistance and the like. In order to make the Tg of the component (A) within such a range, the type and ratio of the monomer components described above may be set as appropriate. In addition, Tg is a value calculated | required from the calculation formula of FOX.

  Although the manufacturing method of (A) component is not specifically limited, For example, emulsion polymerization, soap free emulsion polymerization, dispersion polymerization, feed emulsion polymerization, feed dispersion polymerization, seed emulsion polymerization, seed dispersion polymerization, etc. are employable. The component (A) is obtained by dispersing resin particles in a medium containing water as a main component, and the average particle diameter is usually about 0.05 to 0.3 μm.

  The epoxy group-containing compound (B) in the present invention (hereinafter also referred to as “component (B)”) is an epoxy group-containing compound having two or more epoxy groups in one molecule. This (B) component contributes to improvement of physical properties such as durability, curability, hardness, wear resistance, etc. by a crosslinking reaction with the above-mentioned (A) component, a crosslinking reaction with the (D) component described later, and the like. is there.

  As the component (B), for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, Examples include diglycerol polyglycidyl ether, polyhydroxyalkane polyglycidyl ether, and sorbitol polyglycidyl ether. In addition, water-soluble resins and emulsions composed of polymers (homopolymers or copolymers) of epoxy group-containing monomers can also be mentioned.

  The mixing amount of the component (B) is usually 0.1 to 50 parts by weight, preferably 0.3 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the solid content of the component (A). Part. When the component (B) is too small, it is difficult to obtain sufficient physical properties in terms of durability, curability, hardness, wear resistance, and the like. When there are too many (B) components, adhesiveness tends to appear on the surface of a film, and there exists a possibility of having a bad influence on hardness, abrasion resistance, etc. In addition, the stability of the covering material is impaired, and there is a possibility that the finishing performance and the like are adversely affected.

  The basic compound (C) in the present invention (hereinafter referred to as “component (C)”) is a substance that exhibits basicity in an aqueous solution, and is a component that mainly plays a role of ensuring the stability of the coating material. In the present invention, a coating film excellent in durability, curability, hardness, abrasion resistance, etc. can be formed by the action of the component (C) even when the coating material is stored for a long time. Furthermore, the pot life during mixing of the main agent and the curing agent can be sufficiently secured. This component (C) is considered to suppress the deactivation of the component (B) during storage.

  As the component (C), for example, ammonia, alkylamine, alkanolamine, alkali metal salt, alkali metal siliconate and the like can be used. Among these, examples of the alkylamine include monoethylamine, diethylamine, triethylamine, isopropylamine, diisopropylamine and the like. Examples of the alkanolamine include aminoethanol, aminopropanol, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-methylethanolamine, N-methyldiethanolamine and the like. Examples of the alkali metal salt include alkali metal hydroxides, carbonates, bicarbonates, and the like. Specifically, lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide can be used. Iron hydroxide, potassium carbonate, potassium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate and the like.

In the present invention, it is desirable to contain at least an alkali metal siliconate as the component (C). By using such an alkali metal siliconate, performances such as curability, hardness and abrasion resistance can be further enhanced.
The alkali metal siliconate is a compound represented by R ¹ aSi (OR ² ) b (OM) c. [Wherein, a is an integer of 0 or more (preferably 1), b is an integer of 0 or more (preferably 2), c is an integer of 1 or more (preferably 1), and satisfies a + b + c = 4. R ¹ may be the same or different and represents a hydrocarbon group. R ² may be the same or different and represents a hydrogen atom or a hydrocarbon group. M may be the same or different and represents an alkali metal. ]

Examples of R ¹ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, and n-hexyl. Group, n-heptyl group, n-octyl group, isooctyl group, 2,2,4-trimethylpentyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-octadecyl group, cyclopentyl group, cyclohexyl group , Cycloheptyl group, methylcyclohexyl group, phenyl group, naphthyl group, anthryl group, phenanthryl group, tolyl group, xylyl group, ethylphenyl group, benzyl group, phenylethyl group and the like. Among these, a methyl group, an ethyl group, and a propyl group are preferable, and a methyl group is particularly preferable.
Examples of R ² include a hydrogen atom and the same group as R ¹ . Among these, a hydrogen atom, a methyl group, and an ethyl group are preferable, and a hydrogen atom is particularly preferable.
Examples of M include Li, Na, K and the like, and Na is particularly preferable.

  The mixing amount of the component (C) is usually 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight based on 100 parts by weight of the solid content of the component (A). Parts by weight. When the amount of the component (C) is too small, it is difficult to ensure the stability of the coating material, and when a coating film is formed after long-term storage, it is difficult to obtain desired coating performance. When there are too many (C) components, there exists a possibility that the performance in a weather resistance, water resistance, etc. may become inadequate. If the component (C) is volatile, the odor may be strong.

  The amino group-containing alkoxysilane compound (D) (hereinafter also referred to as “component (D)”) in the present invention is a component that contributes to improving physical properties such as durability, curability, hardness, and abrasion resistance. Such a component (D) is effective for the present invention due to a crosslinking reaction with the component (B), a condensation reaction with the component (D) itself, and in some cases, an action with the component (A) or the component (C). It is thought that it contributes greatly to

  As the amino group-containing alkoxysilane compound, a compound having one or more amino groups and one or more alkoxysilyl groups in one molecule can be used. Specifically, for example, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ. -Aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyldimethylmethoxysilane, γ-aminopropyldimethylethoxysilane, N- (β-aminoethyl) -γ -Aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldiethoxysilane, N- (6-aminohexyl) aminopropyltrimethoxysilane, N- (6-aminohexyl) aminopropyltri Ethoxysilane, N- (β-aminoethyl) -γ Aminoisobutyltrimethoxysilane, N- (β-aminoethyl) -γ-aminoisobutylmethyldimethoxysilane, γ-aminopropyldiisopropyltrimethoxysilane, γ-aminopropyldiisopropyltriethoxysilane, γ-aminopropylmethylbis (trimethylsiloxy) ) Silane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, N-benzyl-γ-amino Propyltrimethoxysilane, N-benzyl-γ-aminopropyltriethoxysilane, 3- (m-aminophenoxy) propyltrimethoxysilane, 3- (m-aminophenoxy) propyltriethoxysilane, m- Minophenyltrimethoxysilane, m-aminophenyltriethoxysilane, p-aminophenyltrimethoxysilane, p-aminophenyltriethoxysilane, aminophenyltrimethoxysilane, aminophenyltriethoxysilane, γ-aminopropyltris (methoxyethoxy) Ethoxy) silane, γ-aminopropyltris (trimethylsiloxy) silane, 2-aminoethylaminomethylbenzyloxydimethylsilane, (aminoethylaminomethyl) phenethyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane , Etc.

  The component (D) is usually mixed in the range of 0.1 to 50 parts by weight, preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight with respect to 100 parts by weight of the solid content of (A). When there are too few (D) components, it becomes difficult to obtain sufficient physical properties in terms of durability, curability, hardness, wear resistance and the like. (D) When there are too many components, stability of coating | covering material falls and there exists a possibility of having a bad influence on finish etc. In addition, the coating is liable to discolor and may adversely affect weather resistance and the like.

  In the present invention, in addition to the above components, the evaporation rate (hereinafter simply referred to as “evaporation rate”) when butyl acetate is 100 is 2 to 50 (preferably 3 to 30, more preferably 5 to 20). It is desirable to mix an organic solvent (E) (hereinafter referred to as “component (E)”) having a solubility of 2 to 80 g / 100 g (preferably 3 to 50 g / 100 g, more preferably 4 to 30 g / 100 g). By using such component (E), it is possible to obtain an aqueous coating material that exhibits excellent performance in terms of curability, hardness, wear resistance, and the like, and also has excellent film forming properties, finish properties, and the like. . In addition, the evaporation rate said here is a relative value when the evaporation rate of butyl acetate is set to 100, and measurement temperature is 20 degreeC. The solubility in water is the mass of an organic solvent that can be dissolved in 100 g of water, and the measurement temperature is 20 ° C.

  Examples of such component (E) include dipropylene glycol dimethyl ether (evaporation rate 16, solubility 53), ethylene glycol monoethyl ether acetate (evaporation rate 21, solubility 23), propylene glycol monomethyl ether acetate (evaporation rate 34, Solubility 16), methyl-1,3-butylene glycol acetate (evaporation rate 34, solubility 7), 3-methoxy-3-methyl-1-butyl acetate (evaporation rate 10, solubility 7), propylene glycol n-butyl ether (evaporation) Speed 9 and solubility 6).

  (E) The mixing amount of component is 0.5-30 weight part normally with respect to 100 weight part of solid content of (A) component, Preferably it is 1-20 weight part, More preferably, it is 2-10 weight part. If the mixing amount of the component (E) is within such a range, it is preferable in terms of manifestation of effects such as curability, hardness, abrasion resistance, film-forming property, and finishability.

In the present invention, in addition to the above components, an organic solvent (F) having a solubility in water of less than 1 g / 100 g (hereinafter referred to as “component (F)”) can be used. However, the mixing ratio is within the range in which (F) component / (E) component is 10 or less (preferably 0.1 or more and 5 or less, more preferably 0.2 or more and 2 or less) in weight ratio. Is desirable. If it is in such a range, the effect of this invention can be heightened, utilizing the effect | action by (E) component.
Examples of the component (F) include diethylene glycol mono 2-ethylhexyl ether, diethylene glycol dibutyl ether, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3. -Pentanediol diisobutyrate and the like.

  In addition to the above components, the aqueous coating material of the present invention includes coloring pigments, extender pigments, aggregates, plasticizers, antifreezing agents, antiseptics, antifungal agents, antibacterial agents, antifoaming agents, pigment dispersants, thickening agents. Agents, leveling agents, wetting agents, pH adjusting agents, fibers, matting agents, UV absorbers, antioxidants, light stabilizers, adsorbents, catalysts, crosslinking agents, etc. Various types of coating materials can be designed by using them in appropriate combinations. The coating material of the present invention can be produced by uniformly mixing these components by a conventional method, if necessary, in addition to the aforementioned components.

  The aqueous coating material of the present invention comprises a main agent containing a water-dispersible resin (A), an epoxy group-containing compound (B), and a basic compound (C), and a curing agent containing an amino group-containing alkoxysilane compound (D). It is desirable to use a two-component type. (E) A component, (F) component, etc. should just be mixed to the main ingredient side normally. In such a two-pack type, the characteristics of the functional group of each component can be fully utilized, which is desirable from the viewpoint of manifesting the effects of the present invention. In such a form, at the time of distribution, a two-component type consisting of a main agent and a curing agent may be used, and these may be mixed and used during coating.

The water-based coating material of the present invention can be used mainly as a finishing material for buildings, civil engineering structures, etc., but since it has excellent effects in curability, hardness, wear resistance, etc., it is particularly suitable for flooring. It is suitable as a covering material.
The base material to be coated is not particularly limited, and examples thereof include various base materials such as concrete, mortar, asphalt, metal, porcelain tile, siding board, extruded plate, and plastic. Such a substrate may have an existing coating film or the like. Specific examples of the existing coating film include an acrylic resin-based coating film, an acrylic silicon resin-based coating film, a urethane resin-based coating film, and an epoxy resin-based coating film.

In the coating of the water-based coating material of the present invention, it can be applied directly to the base material, or it can be applied after some surface treatment (primer, surfacer, filler or other primer treatment). It is. As a coating method, it can be applied by various methods such as brush coating, spray coating, and roller coating. The coating amount is usually about 0.1 to 1 kg / m ² , preferably about 0.2 to 0.5 kg / m ² . Within such a range of coating amount, it is possible to divide the coating into a plurality of times.
The coating and subsequent drying may be usually performed at room temperature (0 to 40 ° C.). The aqueous coating material of the present invention can exhibit advantageous effects even in a relatively low temperature state (0 to 20 ° C.).

When coating on a base material such as concrete, mortar, or asphalt (those that do not have an existing coating film), it is desirable to perform a surface treatment using a primer such as a primer. By this base treatment, the effect of adjusting the surface state of the base material, the effect of reinforcing the surface of the base material, etc. can be obtained, and the finish, adhesion, alkali sealability, etc. of the finally obtained film can be improved. .
As the primer, those containing various resins such as an acrylic resin, a urethane resin, an epoxy resin, and a vinyl chloride resin as a binder can be used. Among these, it is desirable to use an acrylic resin having a Tg of 10 ° C. or higher (preferably 30 ° C. or higher, more preferably 40 ° C. or higher and 80 ° C. or lower) for an undercoat material containing an acrylic resin.

As the acrylic resin in the undercoat material, a cationic acrylic resin emulsion is particularly suitable. Such a cationic acrylic resin emulsion is obtained by dispersing an acrylic resin having a cationic functional group such as an amino group, an ammonium group, or a phosphonium group in an aqueous medium. Specifically, for example,
(1) A polymer obtained by polymerizing a cationic monomer having a cationic functional group such as an amino group, an ammonium group or a phosphonium group together with other polymerizable monomers in an aqueous medium by a method such as emulsion polymerization;
(2) A polymerized monomer that is polymerized in an aqueous medium by a method such as emulsion polymerization in the presence of a cationic water-soluble resin having a cationic functional group such as an amino group, an ammonium group, or a phosphonium group;
(3) Polymerization of a polymerizable monomer in an aqueous medium by a method such as emulsion polymerization in the presence of a cationic surfactant having a cationic functional group such as an amino group, an ammonium group, or a phosphonium group;
(4) A cationic organic solvent-based resin having a cationic functional group such as an amino group, an ammonium group, or a phosphonium group, neutralized with an organic acid, an inorganic acid or the like, added with water, and dispersed in an aqueous medium;
(5) An organic solvent-based resin dispersed in an aqueous medium using a cationic surfactant having a cationic functional group such as an amino group, an ammonium group, or a phosphonium group;
Etc.

In the application of the primer, various methods such as brush coating, spray coating, and roller coating can be appropriately employed. Smeared amount, depending on the form of the primer material, usually 0.05 to 0.5 / ^{m 2,} preferably 0.1~0.4kg / ^{m 2} approximately. Within such a range of coating amount, it is possible to divide the coating into a plurality of times. The coating and subsequent drying may usually be performed at room temperature.

Even when coating on a substrate having an existing coating film, the base treatment can be performed with the primer as described above, but the aqueous coating material of the present invention is excellent in adhesion to various existing coating films. It can also be painted directly.
When the aqueous coating material of the present invention is directly applied to an existing coating film, it is desirable to perform roughening by polishing treatment or the like before coating. Such roughening can remove contaminants and the like adhering to the existing coating film, and the adhesion can be further improved by forming fine irregularities on the surface of the existing coating film. The roughening may be performed using a known polishing tool, grinding tool, or the like.

  Examples are given below to clarify the features of the present invention. In addition, as water-dispersible resin in each coating | covering material, the water-dispersible resin (resins 1-6) of 50 weight% of solid content obtained by emulsion polymerization by the monomer composition shown in Table 1 was used. About other raw materials, what was shown below was used.

The monomers in Table 1 are as follows. Figures in parentheses are Tg of homopolymer.
MMA: Methyl methacrylate (Tg 105 ° C)
ST: Styrene (Tg 100 ° C)
N-BA: n-butyl acrylate (Tg-54 ° C.)
2-EHA: 2-ethylhexyl acrylate (Tg-70 ° C.)
AA: acrylic acid (Tg 106 ° C)

・ Crosslinking agent 1: Epoxy group-containing compound (polyhydroxyalkane polyglycidyl ether)
Crosslinking agent 2: amino group-containing alkoxysilane compound (γ-aminopropyltrimethoxysilane)
Crosslinking agent 3: epoxy group-containing alkoxysilane compound (γ-glycidoxypropyltrimethoxysilane)
Basic compound 1: alkanolamine (2-amino-2-methyl-1-propanol)
Basic compound 2: alkali metal siliconate (sodium methyl siliconate 30% by weight solution)
Organic solvent 1: propylene glycol n-butyl ether (evaporation rate 9, solubility 6)
Organic solvent 2: 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (evaporation rate 0.2, solubility <1)
Coloring pigment: Titanium oxide dispersion (solid content 70% by weight)
・ Thickener: Polyurethane thickener ・ Defoamer: Silicone defoamer

<Manufacture of aqueous coating material>
Each raw material was uniformly mixed by a conventional method to produce a main agent, and coating materials 1 to 13 were obtained by combining the main agent and a curing agent. Tables 2 and 3 show the combinations and combinations of the main agent and the curing agent in each coating material. In each coating material, the main agent and the curing agent were mixed immediately before coating. In addition, in the mixing | blending of Table 2, 3, the mixing | blending of each raw material was shown by the weight part.

<Test method>
Each aqueous coating material was tested for the following curability, wear resistance, finish, and durability.

(1) Curability A fiber-reinforced cement board (100 mm x 100 mm) pre-coated with a primer (coating amount 0.2 kg / m ² ) is placed horizontally, and a coating material is applied 0.3 kg to this board. / M ² , and then cured for 6 hours at a temperature of 23 ° C. and a relative humidity of 50% (hereinafter referred to as “standard state”). A cylindrical metal body (mass 150 g) was placed on the test piece obtained by the above method, and after 10 seconds, the metal body was gently lifted. At this time, “◎” indicates that the metal body is easily separated from the test piece, and “×” indicates that the test piece is lifted together with the metal body, and evaluation is based on four levels (excellent ◎>○>Δ> × poor). Went.

(2) Abrasion resistance A fiber-reinforced cement board (100 mm × 100 mm) preliminarily coated with a primer (coating amount 0.2 kg / m ² ) is placed horizontally, and a coating material is applied to this board in an amount of 0. It was roller-coated at 3 kg / m ² and cured for 7 days in the standard state. About the test piece obtained by the above method, the abrasion resistance test was done according to JISK59707.8. In this test, CS-17 was used as the wear wheel, and the rotation speed was set to 100 rotations, the rotation speed was 1.00 S ⁻¹ , and the load was 4.90 N / wheel. The evaluation criteria are as follows.
A: Less than 10 mg wear loss ○: Less than 10 mg wear loss and less than 15 mg Δ: Less than 15 mg wear loss and less than 20 mg x: More than 20 mg wear loss

  In addition, each coating material was sealed in a container, stored for 14 days in a 50 ° C. environment, and then allowed to cool to room temperature.

(3) Finishing property A fiber-reinforced cement board (900 mm x 900 mm) pre-coated with a primer (coating amount 0.2 kg / m ² ) is placed horizontally, and a coating material is applied 0.3 kg to this board. / M ² and roller-coated, and cured under standard conditions for 7 days. The finish appearance of the test piece obtained by the above method is observed, and “◎” indicates that the coating surface has high smoothness and gloss, and “×” indicates that the coating surface has low smoothness and gloss. Evaluation was performed with excellent ◎>○>△> × poor).

(4) Durability advance undercoat material with the coating (smeared weight 0.2 kg / ^{m 2)} fiber-reinforced cement boards to (150 mm × 70 mm), roller coating with smeared weight 0.3 kg / ^{m 2} of coating material And held for 7 days under standard conditions. The test piece obtained by the above method was exposed for 200 hours with an accelerated weathering tester (“Metal Weather Meter”, manufactured by Daipura Wintes Co., Ltd.), and the appearance of the coated film after the exposure was visually confirmed. The evaluation criteria are “◎” when no abnormality (discoloration, cracking, peeling, swelling, etc.) is recognized in the coating film, and “×” when abnormality is recognized, and four levels (excellent ◎>○> Evaluation was carried out with Δ> x inferior).

<Test results>
The test results are shown in Tables 2 and 3. In the covering materials 1 to 7, good results could be obtained in any test.

Claims (2)

The polymer of the monomer group containing the (meth) acrylic acid alkyl ester and the carboxyl group-containing monomer is used as a resin component, the ratio of the carboxyl group-containing monomer in the monomer group is 0.2 to 20% by weight, and the glass transition temperature is A water dispersible resin (A) having a temperature of 0 to 80 ° C.,
An epoxy group-containing compound (B) having two or more epoxy groups in one molecule;
A basic compound (C), and an amino group-containing alkoxysilane compound (D),
The mixing ratio of each component is 0.1 to 50 parts by weight of the epoxy group-containing compound (B) and 0.01% of the basic compound (C) with respect to 100 parts by weight of the solid content of the water-dispersible resin (A). 10 to 10 parts by weight and 0.1 to 50 parts by weight of the amino group-containing alkoxysilane compound (D).   The said water-dispersible resin (A), the said epoxy group containing compound (B), and the main ingredient containing the said basic compound (C), and the hardening agent containing the said amino group containing alkoxysilane compound (D) are comprised. The aqueous coating material as described.