JP4944581B2 - Aqueous resin dispersion - Google Patents

Description

  The present invention relates to an aqueous resin dispersion (dispersion or dispersion), a coating agent containing the aqueous resin dispersion, and a building substrate to which the coating agent is applied. More specifically, the present invention relates to an aqueous resin dispersion used as a rust inhibitor.

  Nonylphenyl emulsifiers can be used in the production of aqueous resin dispersions. However, the use of emulsifiers having nonylphenyl groups, which are environmental hormones, is decreasing due to increased environmental awareness. Recently, nonylphenyl emulsifiers have been used. There are many things that are not.

For example, Patent Document 1 discloses an aqueous resin dispersion using a non-nonylphenyl emulsifier. The aqueous resin dispersion described in Patent Document 1 is excellent in water resistance, but has insufficient stirring stability and can be gelled over time. Therefore, at present, development of an aqueous resin dispersion that is excellent in environmental aspects and excellent in stirring stability is eagerly desired.
In addition, aqueous resin dispersions have been conventionally used as coating agents for plastic molded products, household appliances, steel products, large structures, vehicles, building materials, buildings, roof tiles, and woodworking. Widely used. Since the coating agent can be applied to a metal such as a reinforcing bar, in recent years, excellent rust prevention performance is required for the aqueous resin dispersion.

  Patent Document 2 discloses an emulsion-based baking type rust preventive in which a specific hot-melt organic filler is blended with an aqueous emulsion mainly composed of a polymer having a coating film-forming ability. The heat-fusible organic filler is melted and fluidized by heating at a temperature of 100 to 200 ° C., filling pores and voids formed in the coating film formed from the aqueous emulsion, and exhibiting high antirust performance.

Patent Document 3 discloses an emulsion-based baking type rust preventive agent in which a hot-meltable organic filler and a xylene resin are blended in an aqueous emulsion mainly composed of a polymer having a coating film-forming ability. By blending the xylene resin, heat melting and fluidization is possible even at a lower temperature, and rust generated from pores and voids can be prevented even in a portion that tends to be a thin film.
Patent Document 4 discloses a rust preventive coating composition containing a polymer emulsion containing internally cross-linked polymer particles and an inorganic pigment. This emulsion is made to have a different phase structure in the core part / shell part, and by controlling the weight ratio of the core part / shell part and the glass transition temperature to specific values, it is possible to dry up and suppress dry spots when forming the coating film. It is disclosed that it can be done.

  However, the emulsion-type baking type rust preventive agents disclosed in Patent Documents 2 to 4 are likely to be gelled due to an increase in viscosity when stirred, and may be difficult to apply to reinforcing bars. In particular, in dipping coating in which a reinforcing bar is immersed in a rust preventive agent and the viscosity of the rust preventive agent increases, a large amount of the rust preventive agent adheres to the reinforcing bar and an appropriate film thickness cannot be obtained. Furthermore, as the viscosity rises, it becomes difficult to immerse itself in the reinforcing bar. There are means for diluting the rust preventive agent or adding a dispersant to delay the increase in viscosity, but the rust preventive performance may be lowered. Moreover, when the rust preventive agent is left without stirring, the components in the rust preventive agent can settle, and the sedimentation of the inorganic filler is particularly remarkable.

JP 2005-272727 A JP-A-62-111779 JP 2000-160064 A Japanese Unexamined Patent Publication No. 2000-17198

  The present invention has been made in view of the above situation, and is an aqueous resin dispersion excellent in stirring stability, easy to apply to a uniform film thickness, and excellent in rust prevention performance, and a coating containing the aqueous dispersion It aims at providing the base material for construction to which the agent and the coating agent were apply | coated.

  As a result of intensive research, the present inventors have obtained a water-based polymer obtained by using an emulsifier having a specific chemical structure and a specific HLB, and a granular whose particle size is controlled to a specific small value. By blending the hot-melt organic filler into the aqueous resin dispersion, the viscosity increase due to long-time stirring is suppressed (that is, excellent stirring stability), and it is easy to apply a uniform film thickness. The present inventors have found that an aqueous resin dispersion having antirust performance can be obtained, and have completed the present invention.

That is, the present invention provides, in one aspect, a new aqueous resin dispersion,
(A) an aqueous polymer obtained by emulsion polymerization using a nonionic emulsifier,
(B) an aqueous resin dispersion comprising a granular hot-melt organic filler,
The nonionic emulsifier has a styrenated phenyl group and has an HLB of 16 or more,
(B) The granular heat-fusible organic filler is an aqueous resin dispersion having an average particle diameter of 0.1 μm to 0.5 μm.

In one embodiment of the present invention, the nonionic emulsifier provides an aqueous resin dispersion having an HLB of 17.5 to 19.0.
Furthermore, in another aspect of the present invention, a coating agent comprising the above-mentioned aqueous resin dispersion is provided.
In another aspect of the present invention, there is provided a coating agent as described above for use as a rust inhibitor.
Moreover, in the preferable summary of this invention, the base material for construction to which the above-mentioned coating agent was apply | coated is provided.

The aqueous resin dispersion according to the present invention is
(A) an aqueous polymer obtained by emulsion polymerization using a nonionic emulsifier,
(B) an aqueous resin dispersion comprising a granular hot-melt organic filler,
The nonionic emulsifier has a styrenated phenyl group and has an HLB of 16 or more,
(B) Since the granular hot-melt organic filler has an average particle size of 0.1 μm to 0.5 μm,
An increase in viscosity due to long-time stirring is suppressed (that is, excellent stirring stability), and it is easy to apply a uniform film thickness, and further, an aqueous resin dispersion having rust prevention performance can be obtained. Since the resin dispersion according to the present invention is aqueous, it is excellent in environmental aspects.

By controlling the HLB of the nonionic emulsifier to 17.5 to 19.0, the above performance can be further improved.
The coating agent containing the aqueous resin dispersion according to the present invention is excellent in stirring stability, can be easily applied to a uniform film thickness, is excellent in environmental aspects, and has rust prevention performance. Therefore, the coating agent according to the present invention can be used as a rust preventive agent as well as being used as a top coat agent and an undercoat agent.
The building base material to which the coating agent according to the present invention is applied has a uniform film and is not easily rusted.

BEST MODE FOR CARRYING OUT THE INVENTION

In this specification, “(A) water-based polymer” refers to a polymer that can be dispersed or dissolved in an aqueous medium.
“Aqueous medium” refers to general water such as tap water, distilled water or ion-exchanged water, but is a water-soluble or water-dispersible organic solvent, which is a monomer or the like of the resin relating to the present invention. It may contain organic solvents that are poorly reactive with the raw materials, such as acetone and ethyl acetate, and may further contain water-soluble or water-dispersible monomers, oligomers, prepolymers and / or resins, etc. Thus, it may contain an emulsifier, a polymerizable emulsifier, a polymerization initiator, a chain extender and / or various additives, which are usually used when producing a water-based resin or a water-soluble resin.
“Emulsion” means, for example, (A) a state in which an aqueous polymer is dispersed in an aqueous medium, more specifically, (A) an aqueous dispersion of an aqueous polymer, The description “A) Emulsion of water-based polymer” is distinguished from the description “(A) water-based polymer”.

  The “(A) water-based polymer” according to the present invention is obtained by emulsion polymerization using a nonionic emulsifier having a specific HLB and having a styrenated phenyl group as a skeleton. The HLB of the nonionic emulsifier is 16.0 or more, and preferably 17.5 to 19.0. When the HLB is lower than 16.0, the resulting aqueous resin dispersion is increased in viscosity when stirred for a long time, and is not suitable for coating.

  As a nonionic emulsifier having an HLB of 16.0 or more and having a styrenated phenyl group as a skeleton, specifically, for example, polyoxyethylene styrenated phenyl ether (Neugen EA197D, 207D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ( Emulgen A500, manufactured by Kao Corporation).

The emulsifier has both a hydrophilic group and a hydrophobic group in the molecule, and HLB (Hydrophyl Lipophil Balance) expresses the balance between hydrophilicity and hydrophobicity as a number. HLB has the basic physical properties of nonionic emulsifiers. It is one of the representative indicators. There are many equations for obtaining HLB, but in the present invention, the following Griffin equation is used.
HLB = (molecular weight of hydrophilic portion / total molecular weight) × 100/5

“Styrenated phenyl group” refers to a phenyl group to which styrene is added. A plurality of styrenes may be added to the phenyl group. Examples of the styrenated phenyl group include groups shown in the following chemical formulas 1 to 5.

  The “emulsion polymerization” can be performed using a generally-used method of emulsion polymerization, and is not particularly limited as long as (A) an aqueous polymer is obtained. As emulsion polymerization, for example, (i) a method in which a monomer having an ethylenic double bond and an emulsifier are charged in an aqueous medium for polymerization, and (ii) a monomer having an ethylenic double bond and an emulsifier are continuously used. Alternatively, a method of polymerizing by dropping dropwise into an aqueous medium and (iii) adding an ethylenic double bond monomer and an emulsifier to water to prepare an emulsion, which is continuously or intermittently aqueous Examples thereof include a method of dropping and polymerizing in a medium.

(A) The water-based polymer preferably has a minimum film-forming temperature of 50 ° C. or lower, and more preferably 20 ° C. or lower. When the minimum film-forming temperature exceeds 50 ° C., a high temperature is required for film formation, and there is a possibility that blisters or rough air holes that are difficult to repair are formed in the formed coating film during the film formation process. Particularly in concrete reinforcement applications, since the produced coating film is in contact with the alkali component of concrete for a long period of time, it is desirable to use a water-based polymer having a coating film forming ability that is not easily decomposed even if it is in contact with the alkali component for a long period of time.
The minimum film-forming temperature is usually also referred to as MFT (Minimum Film-Forming Temperature), and means the lowest temperature at which the emulsion can be dried to form a film. In the present invention, MFT refers to a value measured by the method described in JIS K 6828-2. A thermal gradient test apparatus (manufactured by Rigaku Industry Co., Ltd.) was used as a measuring instrument.

  (A) The water-based polymer is not particularly limited as long as it is obtained by emulsion polymerization using the above-mentioned specific emulsifier and has a film-forming ability. Specifically, for example, carboxyl group-containing acrylic copolymer, carboxyl group-containing styrene-acrylic copolymer, glycidyl group-containing acrylic copolymer, glycidyl group-containing styrene-acrylic copolymer and the like are exemplified. be able to. These can be used alone or in combination of two or more.

  In the present invention, “(B) granular heat-fusible organic filler” is an organic filler that is granular and melts by heat, and is particularly limited as long as the desired aqueous resin dispersion can be obtained. However, the average particle size needs to be 0.1 to 0.5 μm. When the average particle diameter is less than 0.1 μm, the fluidity of the aqueous resin dispersion decreases, and the film thickness at each part of the coated substrate becomes non-uniform. When the average particle diameter exceeds 0.5 μm, the obtained aqueous resin dispersion tends to cause sagging after coating on the base material, and therefore the film thickness becomes uneven at each part of the coated base material.

  In the present invention, the average particle diameter means a value measured by a dynamic light scattering method. PAR-III (made by Otsuka Electronics Co., Ltd.) is used as a measuring instrument. (B) When the granular hot-melt organic filler is an emulsion, the particle size means the size of micelles formed in the aqueous medium. Therefore, the particle diameter can be adjusted by the amount (or number) of micelles. When the number of micelles is small, since a large amount of polymer is contained per micelle, the volume of the micelle increases, and as a result, the particle diameter increases. When the number of micelles is large, the amount of polymer contained in one micelle is small, so that the volume of the micelle becomes small, and as a result, the particle diameter becomes small. The number of micelles in the aqueous medium can be adjusted by the amount of emulsifier added. In order to form a large amount of micelles, a large amount of emulsifier may be added to the aqueous medium, and when the amount of micelles may be small, a small amount of emulsifier may be added to the aqueous medium.

  (B) The particulate heat-fusible organic filler may be (A) one having good compatibility with the water-based polymer, or (A) one that can be dispersed in the water-based polymer. Any of emulsions may be used. And it is preferable to select and use the optimal properties and forms as appropriate according to the application. For example, when the aqueous resin dispersion is for concrete reinforcing bars, it is desirable to use (B) a granular hot-melt organic filler excellent in alkali resistance together with (A) a water-based polymer excellent in alkali resistance.

(B) Specific examples of the granular hot-melt organic filler include, for example, polystyrene, acrylonitrile / styrene (0 / 100-60 / 40) copolymer, styrene / methyl methacrylate (0 / 100-100 / 0) copolymer Examples thereof include synthetic resins such as coalescence, polypropylene, polyethylene, phenol resin initial condensate, uncured epoxy resin, rosin, petroleum resins, bituminous materials exhibiting a glass-like solid at room temperature, and the like. These specific examples are not only excellent in compatibility with the (A) water-based polymer, but also excellent in alkali resistance, and are particularly suitable in the present invention.
Note that (B) granular heat-fusible organic filler is produced by using the above-mentioned specific emulsifier used in the production of (A) an aqueous polymer even if emulsion polymerization is used. The hot-melt organic filler does not contain (A) an aqueous polymer.

  (B) The granular heat-meltable organic filler has a melting point or softening point (hereinafter also referred to as “melting point”) that is preferably at least 10 ° C. higher than the minimum film-forming temperature of the (A) water-based polymer. The (B) granular hot-melt organic filler preferably has a melting point at a temperature of 40 to 250 ° C. Here, "melting point" means that when measuring the dynamic viscoelasticity of (B) granular hot-melt organic filler under the condition of frequency 1.6 Hz, (B) granular hot-melt organic filler is The temperature that changes from the elastic region to the flow region. As a measuring device, Rheogel E-4000 (manufactured by UBM) was used.

When the melting point of (B) is lower than the minimum film-forming temperature of (A) or when the difference between the melting point of (B) and the minimum film-forming temperature of (A) is less than 10 ° C., film formation is sufficiently performed. Since the melting of (B) proceeds before it is broken, film formation may be inhibited and a dense coating film may not be obtained.
Moreover, when the minimum film-forming temperature of (B) is less than 40 degreeC, it is not practical as a coating agent, and handling becomes troublesome. On the other hand, when the melting point of (B) exceeds 250 ° C., when the coating film of the aqueous resin dispersion is baked, the physical properties of the coating film may deteriorate due to the high temperature exceeding 250 ° C. is not.
Therefore, (B) the granular hot-melt organic filler has a melting point or softening point (hereinafter also referred to as “melting point”) at least 10 ° C. higher than the minimum film-forming temperature of the aqueous polymer (A), And it is especially preferable that (B) granular heat-fusible organic filler has a melting point of the temperature of 40-250 degreeC.

  The blending amount of the (B) granular hot-melt organic filler in the aqueous resin dispersion is different depending on the type, but in general, the solid content of the aqueous polymer (A) in the aqueous resin dispersion (that is, (A) It is preferable that (B) the granular hot-melt organic filler is 3 to 500 parts with respect to 100 parts by weight (hereinafter abbreviated as “parts”) of the aqueous polymer. In order to obtain a dense coating film, it can be set to 10 to 500 parts when a bitumen emulsion is not used, and can be set to 3 to 500 parts as described above when a bitumen emulsion is used. In any case, the amount is particularly preferably 10 to 100 parts. (B) If the blending amount of the granular heat-fusible organic filler is more than 500 parts, not only the denseness and adhesion of the coating film will not be further improved, but also the mechanical properties of the coating film may be impaired in some cases. It is possible. Therefore, the blending amount of the (B) granular hot-melt organic filler is preferably set to 3 to 500 parts with respect to 100 parts of the (A) aqueous polymer.

  (B) Although the compounding quantity of a granular heat-meltable organic filler is as above-mentioned, it is used together with the inorganic filler mentioned later, and the total amount of both, (B) above-mentioned (B) granular heat-meltable organic filler You may make it satisfy | fill a compounding quantity.

The present invention provides a coating agent comprising the above aqueous resin dispersion. The coating agent can be obtained by appropriately blending the aqueous resin dispersion with an inorganic filler, a rust preventive pigment, various additives and the like as necessary. In the present invention, a bitumen emulsion is not particularly required, but a bitumen emulsion may be blended.
As "bitumen emulsion", for example, one or more bitumen products such as straight asphalt, semi-blown asphalt, natural asphalt, cut back asphalt, coal tar, oil tar, tar pitch, petroleum pitch, fatty acid pitch, emulsifier, stable Examples thereof include those obtained by emulsification in an aqueous medium using an agent, a protective colloid and the like.

  Examples of the inorganic filler include powdery materials or granular materials made of, for example, cryolite, silica sand, talc, clay, anhydrous calcium carbonate, and the like, as well as asbestos. This inorganic filler can improve the coating characteristics of the aqueous resin dispersion and can reinforce the coating film to prevent cracking over time. Further, when the aqueous resin dispersion according to the present invention is used for concrete, the inorganic filler can exhibit various preferable effects such as improving the adhesion between the coating film and the concrete.

  When the bituminous emulsion is not blended, the amount of the inorganic filler is blended so that the inorganic filler is 40 to 500 parts, preferably 80 to 400 parts per 100 parts of the aqueous polymer (solid content). It is desirable to do. Moreover, when mix | blending a bitumen emulsion, the compounding quantity of an inorganic filler can be increased more than the above, (A) 40-800 parts of inorganic fillers with respect to 100 parts of aqueous polymer (solid content), Preferably Can be blended so as to be 80 to 500 parts.

The “rust preventive pigment” is not particularly limited as long as it is blended with a normal rust preventive paint. Specific examples of the rust preventive pigment include zinc phosphate, aluminum phosphate, lead phosphate, zinc molybdate, barium metaborate, and calcium hydroxide. These rust preventive pigments can be used alone or in combination, and the rust preventive effect of the coating agent can be improved.
As for the compounding quantity of a rust preventive pigment, it is desirable to mix | blend so that a rust preventive pigment may be 10-200 parts with respect to 100 parts of (A) water-based polymer (solid content). When the blending amount is less than 10 parts, it is not possible to expect a sufficient improvement in rust prevention effect, and even if it exceeds 200 parts, the rust prevention effect is not further improved, and the storage stability of the coating agent itself is deteriorated. Etc. may be caused.

  The coating agent of the present invention can be appropriately selected and blended with other various additives such as a pigment dispersant, an antifoaming agent, a thickener, a colorant, and a solvent, if necessary, in addition to the above raw materials. . In this case, each additive is selected based on the application target of the coating agent.

As the “pigment dispersant”, for example,
Polycarboxylic acid resin;
Polyester resin;
Polyphosphate resin;
Polyethylene glycol resin;
Polyurethane resin;
Polyamine resins;
Polyacrylic resin;
Acrylic resins such as acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, acrylic acid-acrylic ester copolymer;
Styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid Styrene-acrylic acid resins such as ester copolymers;
Styrene-maleic anhydride copolymer;
Examples thereof include a styrene sulfonic acid-maleic anhydride copolymer, a vinyl acetate-maleic anhydride copolymer, and salts thereof.

As an “antifoaming agent”, for example,
Silicone-based antifoaming agents such as dimethylpolysiloxane, polyoxyalkylene-modified silicone, organic-modified polysiloxane, and fluorine silicone;
Oil-based antifoaming agents such as castor oil, sesame oil, linseed oil, animal and vegetable oils;
Fatty acid-based antifoaming agents such as stearic acid, oleic acid, palmitic acid;
Isoamyl stearic acid, diglycol lauric acid, distearyl succinic acid, distearic acid, sorbitan monolauric acid, glycerin fatty acid ester, polyoxyethylene sorbitan, butyl stearate monolaurate, sucrose fatty acid ester, ethyl acetate alkyl ester of sulfonated lithinolic acid Fatty acid ester antifoaming agents such as natural wax;
Alcohol-based antifoaming agents such as polyoxyalkylene glycol and derivatives thereof, polyoxyalkylene alcohol hydrate, diamylphenoxyethanol, 3-heptanol, 2-ethylhexanol;
Ether type antifoaming agents such as 3-heptylcellosolve and nonylcellosolve-3-heptylcarbitol;
Phosphate-based antifoaming agents such as tributyl phosphate, sodium octyl phosphate, tris (butoxyethyl) phosphate;
Amine-based antifoaming agents such as diamylamine;
Amide antifoaming agents such as polyalkylene amide, acylate polyamine, dioctadecanoyl piperidine;
Metal soap antifoaming agents such as aluminum stearate, calcium stearate, potassium oleate, calcium salt of wool olein;
Examples thereof include sulfonate ester antifoaming agents such as sodium lauryl sulfonate and sodium dodecyl sulfonate.

As a “thickener”, for example,
Gelatin, casein, alginic acid, propylene glycol alginate, triethanolamine alginate, sodium alginate, sodium alginate, guar gum, gellan gum, xanthan gum, welan gum, ethylcellulose, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylcellulose, etc. Natural polymer thickener;
Polyvinyl thickeners such as polyvinyl alcohol, polyvinyl pyrrolidone and polyvinyl benzyl ether copolymer;
Sodium polyacrylate, acrylic acid- (meth) acrylic acid ester copolymer, polysodium methacrylate, methacrylic acid- (meth) acrylic acid ester copolymer, modified polyacrylic acid sulfonate, modified polymethacrylic acid sulfonic acid Salt, styrene-acrylic acid copolymer, styrene-acrylic acid- (meth) acrylic acid ester copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid- (meth) acrylic acid ester copolymer, etc. (Meth) acrylic acid thickener;
Polyether thickeners such as pluronic polyether, polyether dialkyl ester, polyether urethane modified product, polyether dialkyl ether, polyether epoxy modified product;
Itaconic acid thickeners such as polyitaconic acid, itaconic acid- (meth) acrylic acid ester copolymer, itaconic acid-maleic acid copolymer, itaconic acid-acrylic acid copolymer, itaconic acid-methacrylic acid copolymer ;
Maleic anhydride- (meth) acrylic acid ester copolymer, maleic anhydride-acrylonitrile copolymer, maleic anhydride-vinyl acetate copolymer, vinyl methyl ether-maleic anhydride copolymer partial ester, etc. Acid thickeners;
A higher fatty acid amide type thickener etc. can be illustrated.

As a “colorant”, for example,
Insoluble azo pigments such as fast yellow, diazo yellow, diazo orange and naphthol red;
Phthalocyanine pigments such as copper phthalocyanine;
Dyeing lakes such as Fanar Lake, Tannin Lake and Katanol;
Isoindolino pigments such as isoindolino yellow greenish and isoindolino yellow reddish;
Quinacridone pigments;
Perylene pigments such as perylene scarlet and perylene maroon;
Carbon black, lead white, red lead, yellow lead, silver vermilion, ultramarine, cobalt oxide, titanium dioxide, titanium yellow, strontium chromate, molybdenum red, molybdenum white, iron black, ritbon, emerald green, guinea green, cobalt blue, etc. Examples thereof include pigments.

As a “solvent”, for example,
Methanol, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, ethylene glycol, ethylene glycol mono (di) alkylene ether, ethylene glycol monoacetyl monoalkyl ether, diethylene glycol, diethylene glycol mono (di) alkyl ether, diethylene glycol monoacetyl monoalkyl Ether, propylene glycol, propylene glycol mono (di) alkyl ether, propylene glycol monoacetyl monoalkyl ether, dipropylene glycol, dipropylene glycol mono (di) alkyl ether, dipropylene glycol monoacetyl monoalkyl ether, dialkyl ketone, N- Alkylpyrrolidone, (alkyl) benzyl alcohol, tetrahydroph Emissions can be exemplified 2,2,4-trimethyl-1,3-pentanediol mono-butylate.

The coating agent according to the present invention is preferably used as 50 to 80% by weight.
The concentration of the coating agent is a percentage of the nonvolatile component weight relative to the total weight of the coating agent. Specifically, the weight of the coating agent including all components such as component (A), component (B), other additives, and aqueous medium is weighed, and then the volatile components such as the aqueous medium are evaporated to remove the evaporation residue. By measuring the weight of the minute, the concentration of the coating agent is calculated.

The viscosity of the coating agent is preferably 100 to 7000 (mPa.s) within the above concentration range. In the present invention, the viscosity refers to a value measured at a temperature of 30 ° C. with a BM viscometer.
It is preferable to adjust the coating agent so that the pH is 8.0 to 14.0. The pH is measured with a pH meter.

  The specific gravity of the coating agent is preferably 1.0 to 1.8. The specific gravity of the coating agent described in the present specification is calculated using water as a standard substance, and refers to the ratio of the mass of the coating agent to the mass of water. Specific gravity is measured by the cup method. In the cup method, a standard material (water) and a sample (coating agent) are filled in a cup of the same volume, and the weight of the coating agent with respect to the weight of water is measured.

The coating agent according to the present invention is useful as a rust inhibitor, particularly as a seizure type rust inhibitor. The stoving type rust preventive can be produced by using the above-mentioned raw materials according to a usual method for producing an emulsion-based coating agent.
The rust prevention treatment with the baking type rust inhibitor is usually performed as follows. First, a baking type rust preventive agent is applied to an object to be processed such as a concrete rebar using an appropriate means such as roller coating or dip coating, followed by preliminary drying.
The temperature of the preliminary drying is preferably 20 to 100 ° C, more preferably around 80 ° C. When the temperature of the preliminary drying is less than 20 ° C., the heat flow property of the coating film is not sufficient, and pores and the like at the site where the coating film tends to become a thin film cannot be sufficiently filled. When the preliminary drying temperature exceeds 100 ° C., the coating film may be swollen or coarse pores, and it may be difficult to form a uniform and dense rust-proof coating film.

The time required for the preliminary drying may be a long time, but is preferably 5 to 60 minutes. By the preliminary drying, the (A) water-based polymer contained in the rust preventive agent is formed into a film. Next, by performing this drying (baking), a polymer film containing (B) granular heat-fusible organic filler and other components (inorganic filler, rust preventive pigment, etc.) or binding is obtained. It is formed on the workpiece. The main drying is performed by heat treatment at a temperature at which the hot-meltable organic filler melts and fluidizes, generally in the range of 100 to 200 ° C. for 5 to 30 minutes or more. As a result, the hot-melt organic filler is melted and fluidized, filling the pinholes and voids of the coating film, and an extremely dense rust-proof coating film is obtained.
In addition, when the solid content of (A) and (B) is defined as organic solid content, and the inorganic filler and the rust preventive pigment are defined as inorganic solid content, the inorganic solid content / organic solid content is 2 to 5, particularly 3 to 4. It is preferable to become.

  The coating agent according to the present invention can be used in various applications, for example, for plastic molded products, home appliances, steel products, large structures, vehicles (for example, solid colors for repairing automobiles and metallic bases). Can be used for various undercoats, intermediate coats, top coats, etc. The coating agent having anti-corrosion performance is particularly preferably used for a building base material, and more preferably, it is contained in a building structural member for assembling a reinforcing bar or member contained in the building structural member for reinforcement. It can be used for metal fittings.

  Examples of the building structural member include concrete, PC panel, cement mortar, ALC panel, concrete block, slate board, asbestos cement siding, and the like. Although it does not specifically limit as a reinforcing bar contained in a building structural member, For example, a deformed reinforcing bar, a wire net called a rasami or a metal lath, a lattice reinforcing bar called a mesh, etc. can be illustrated. Examples of the metal fittings included in the building structural member include an iron plate processed into a flat, L-shaped, C-shaped piece or the like for assembly.

Examples of the method for applying the coating agent include dip coating (dipping coating), air spray, airless spray, electrostatic coating, roll coater coating, flow coater coating, roller coating, brush coating, and the like. In particular, dip coating is preferred as a method of applying to reinforcing bars or metal fittings in building structural members.
Further, a cement-based rust preventive agent or the like may or may not be further applied to the reinforcing bar or metal fitting to which the coating agent has been applied.

The present invention will be described below with reference to examples and comparative examples, but these examples are for explaining the present invention and do not limit the present invention in any way.
First, each component shown below was prepared.
[emulsifier]
・ Polyoxyethylene styrenated phenyl ether (HLB 17.5)
(Neugen EA197D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (hereinafter also referred to as “EM1”)
・ Polyoxyethylene styrenated phenyl ether (HLB 18.7)
(Neugen EA207D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (hereinafter also referred to as “EM2”)
・ Polyoxyethylene styrenated phenyl ether (HLB 15.6)
(Neugen EA177D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (hereinafter also referred to as “EM'3”)
・ Polyoxyethylene isodecyl ether (HLB 17.9)
(Neugen SD300, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (hereinafter also referred to as “EM'4”)
・ Polyoxyethylene nonylphenyl ether (HLB 17.5)
(Emulgen 935, manufactured by Kao Corporation) (hereinafter also referred to as “EM'5”)
[Reactive emulsifier]
・ Alkylallylsulfosuccinic acid sodium salt (Eleminol JS-2, manufactured by Sanyo Chemical Industries)

[Emulsion of water-based polymer (A-1)]
1 part by weight of an emulsifier (Neugen EA197D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is dissolved in 30 parts by weight of distilled water, 43 parts by weight of styrene (manufactured by Wako Pure Chemical Industries), 2-ethylhexyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 54 parts by weight and 3 parts by weight of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were blended and emulsified to prepare an emulsion. On the other hand, 60 parts by weight of distilled water and 1 part by weight of an emulsifier (Neugen EA197D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube, and nitrogen gas is added. The liquid temperature was adjusted to 75 ° C by heating with stirring. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. After cooling the obtained reaction mixture, aqueous ammonia was added to adjust the pH to 9, and 0.2 parts by weight of an antiseptic (ACTICIDE MBS, manufactured by So Japan), an antifoaming agent (Nopco 8034, San Nopco) (Product) 0.1 part by weight was added to obtain an aqueous emulsion of a carboxyl group-containing styrene-acrylic copolymer. The MFT was 0 ° C.

[Emulsion of water-based polymer (A-2)]
Emulsifier (Neugen 207D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.1 parts by weight is dissolved in distilled water 29.9 parts by weight, styrene (Wako Pure Chemical Industries, Ltd.) 43 parts by weight, 2-ethylhexyl acrylate (Wako Pure Chemical Industries, Ltd.) 54 parts by weight manufactured by Kogyo Co., Ltd. and 3 parts by weight methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were blended and emulsified to prepare an emulsion. Meanwhile, 59.9 parts by weight of distilled water and 1.1 parts by weight of an emulsifier (Neugen 207D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were added to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet tube. The mixture was heated with stirring while blowing nitrogen gas, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. After cooling the obtained reaction mixture, aqueous ammonia was added to adjust the pH to 9, and 0.2 parts by weight of an antiseptic (ACTICIDE MBS, manufactured by So Japan), an antifoaming agent (Nopco 8034, San Nopco) (Product) 0.1 part by weight was added to obtain an aqueous emulsion of a carboxyl group-containing styrene-acrylic copolymer. The MFT was 0 ° C.

[Emulsion of water-based polymer (X-1)]
Emulsifier (Neugen EA177D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.6 parts by weight is dissolved in distilled water 30.4 parts by weight, styrene (Wako Pure Chemical Industries, Ltd.) 43 parts by weight, 2-ethylhexyl acrylate (Wako Pure Chemical Industries, Ltd.) 54 parts by weight manufactured by Kogyo Co., Ltd. and 3 parts by weight methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were blended and emulsified to prepare an emulsion. Meanwhile, 60.4 parts by weight of distilled water and 0.6 parts by weight of an emulsifier (Neugen EA177D, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen introduction tube. The mixture was heated with stirring while blowing nitrogen gas, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. After cooling the obtained reaction mixture, aqueous ammonia was added to adjust the pH to 9, and 0.2 parts by weight of an antiseptic (ACTICIDE MBS, manufactured by So Japan), an antifoaming agent (Nopco 8034, San Nopco) (Product) 0.1 part by weight was added to obtain an aqueous emulsion of a carboxyl group-containing styrene-acrylic copolymer. The MFT was 0 ° C.

[Emulsion of water-based polymer (X-2)]
An emulsifier (Neugen SD300, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is dissolved in 30.4 parts by weight of distilled water, 43 parts by weight of styrene (manufactured by Wako Pure Chemical Industries, Ltd.), 2-ethylhexyl acrylate (Wako Pure Chemical Industries, Ltd.). 54 parts by weight manufactured by Kogyo Co., Ltd. and 3 parts by weight methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were blended and emulsified to prepare an emulsion. Meanwhile, 60.4 parts by weight of distilled water and 0.6 parts by weight of an emulsifier (Neugen SD300, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube. The mixture was heated with stirring while blowing nitrogen gas, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. After cooling the obtained reaction mixture, aqueous ammonia was added to adjust the pH to 9, and 0.2 parts by weight of an antiseptic (ACTICIDE MBS, manufactured by So Japan), an antifoaming agent (Nopco 8034, San Nopco) (Product) 0.1 part by weight was added to obtain an aqueous emulsion of a carboxyl group-containing styrene-acrylic copolymer. The MFT was 0 ° C.

[Emulsion of water-based polymer (X-3)]
Emulsifier (Emulgen 935, manufactured by Kao Corporation) 0.6 parts by weight is dissolved in distilled water 30.4 parts by weight, styrene (Wako Pure Chemical Industries) 43 parts by weight, 2-ethylhexyl acrylate (Wako Pure Chemical Industries, Ltd.) ) 54 parts by weight and 3 parts by weight of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were mixed and emulsified to prepare an emulsion. Meanwhile, 60.4 parts by weight of distilled water and 0.6 parts by weight of an emulsifier (Emulgen 935, manufactured by Kao Corporation) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube, and nitrogen is added. While blowing gas, the mixture was heated with stirring, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. After cooling the obtained reaction mixture, aqueous ammonia was added to adjust the pH to 9, and 0.2 parts by weight of an antiseptic (ACTICIDE MBS, manufactured by So Japan), an antifoaming agent (Nopco 8034, San Nopco) (Product) 0.1 part by weight was added to obtain an aqueous emulsion of a carboxyl group-containing styrene-acrylic copolymer. The MFT was 0 ° C.

[Emulsion of granular hot-melt organic filler (B-1)]
1 part by weight of a reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) was dissolved in 30 parts by weight of distilled water, and 100 parts by weight of styrene was blended and emulsified to prepare an emulsion. Meanwhile, 60 parts by weight of distilled water and 1 part by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Kasei Kogyo Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube, and nitrogen is added. While blowing gas, the mixture was heated with stirring, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an emulsion in which polystyrene resin particles having a particle diameter of 0.2 μm were dispersed. The melting point of the dry film was 100 ° C.

[Emulsion of granular hot-melt organic filler (B-2)]
1 part by weight of a reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) was dissolved in 30 parts by weight of distilled water, and 100 parts by weight of styrene was blended and emulsified to prepare an emulsion. Meanwhile, 60 parts by weight of distilled water and 1 part by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Kasei Kogyo Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube, and nitrogen is added. While blowing gas, the mixture was heated with stirring, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 10% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an emulsion in which polystyrene resin particles having a particle diameter of 0.1 μm were dispersed. The melting point of the dry film was 100 ° C.

[Emulsion of hot-meltable organic filler (B-3)]
Reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) 1.3 parts by weight was dissolved in 30 parts by weight of distilled water, 100 parts by weight of styrene was mixed and emulsified to prepare an emulsion. Meanwhile, 60 parts by weight of distilled water and 0.7 parts by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube. The mixture was heated with stirring while blowing nitrogen gas, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 2% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 parts by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an emulsion in which polystyrene resin particles having a particle diameter of 0.5 μm were dispersed. The melting point of the dry film was 100 ° C.

[Emulsion of hot-meltable organic filler (B-4)]
1 part by weight of a reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Kasei Kogyo Co., Ltd.) is dissolved in 30 parts by weight of distilled water, and 78 parts by weight of styrene and 22 parts by weight of 2-ethylhexyl acrylate are mixed and emulsified. It was adjusted. Meanwhile, 60 parts by weight of distilled water and 1 part by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Kasei Kogyo Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube, and nitrogen is added. While blowing gas, the mixture was heated with stirring, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an emulsion in which polystyrene resin particles having a particle diameter of 0.2 μm were dispersed. The melting point of the dried film was 40 ° C.

[Emulsion of Hot-meltable Organic Filler (B-5)]
1 part by weight of a reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) is dissolved in 30 parts by weight of distilled water, 50 parts by weight of styrene and 50 parts by weight of 2-ethylhexyl acrylate are mixed and emulsified, It was adjusted. Meanwhile, 60 parts by weight of distilled water and 1 part by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Kasei Kogyo Co., Ltd.) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube, and nitrogen is added. While blowing gas, the mixture was heated with stirring, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 5% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an aqueous dispersion of polystyrene resin particles having a particle diameter of 0.2 μm. The melting point of the dry film was 0 ° C.

[Emulsion of Hot-meltable Organic Filler (Y-1)]
A reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) was dissolved in 30 parts by weight of distilled water, and 100 parts by weight of styrene was mixed and emulsified to prepare an emulsion. Meanwhile, 60 parts by weight of distilled water and 1.2 parts by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube. The mixture was heated with stirring while blowing nitrogen gas, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 10% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 part by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an emulsion in which polystyrene resin particles having a particle size of 0.08 μm were dispersed. The melting point of the dry film was 100 ° C.

[Emulsions of heat-meltable organic filler (Y-2)]
A reactive emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) was dissolved in 30 parts by weight of distilled water, and 100 parts by weight of styrene was mixed and emulsified to prepare an emulsion. Meanwhile, 60 parts by weight of distilled water and 0.5 parts by weight of an emulsifier (Eleminol JS-2, manufactured by Sanyo Chemical Industries) are added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube. The mixture was heated with stirring while blowing nitrogen gas, and the liquid temperature was adjusted to 75 ° C. In this state, first, about 2% by volume of the previously prepared emulsion and 10% by volume of an aqueous initiator solution (0.2 parts by weight of sodium persulfate dissolved in 10 parts by weight of distilled water) were added. Then, after stirring, the remaining emulsion and the aqueous initiator solution were added dropwise over about 3 hours to react, and a complete reaction was performed at the same temperature (75 ° C.) for about 1 hour. The obtained reaction mixture was cooled to obtain an emulsion in which polystyrene resin particles having a particle diameter of 0.7 μm were dispersed. The melting point of the dry film was 100 ° C.

[Silica sand]
Silica sand (Takehara Chemical Co., Ltd.)
[Anhydrous calcium carbonate powder]
Anhydrous calcium carbonate (first grade heavy calcium carbonate, manufactured by Takehara Chemical Co., Ltd.)
[Zinc phosphate]
Zinc phosphate tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
[Bengara]
Bengala (Santetsu SR-840, made by Gokoku Dye)
[Dispersant]
Styrene / maleic anhydride copolymer (NARLEX D72, manufactured by National Starch and Chemical Co., Ltd.)
[Thickener]
Hydroxyethyl cellulose (HEC SP600, manufactured by Daicel Chemical Industries)
[Propylene glycol]
Propylene glycol (Wako Pure Chemical Industries)
[Sodium hydroxide]
Sodium hydroxide (Wako Pure Chemical Industries)
[Preservative]
Complex type isothiazoline preservative (ACTICIDE MBS, manufactured by So Japan)
[Defoaming agent]
Nopco NXZ (manufactured by San Nopco)

<Examples 1-6>
As shown in Table 1, each component was blended to prepare a coating agent having an antirust effect.
<Comparative Examples 1-5>
The types and blending ratios of the respective components were blended as shown in Table 2 to prepare a coating agent having an antirust action.

<Evaluation method>
Evaluation of the coating agent of an Example and a comparative example was performed as follows.
[concentration]
About 1 g of a sample is precisely weighed in an aluminum foil dish with a constant weight in advance, put in an electric constant temperature dryer maintained at 105 ° C. to 110 ° C., heated for 3 hours, then taken out from the electric constant temperature dryer and allowed to cool in a desiccator. . The weight of the sample after drying is obtained and calculated from the following formula.
Concentration (%) = (A / S) 100
[S: Weight before drying sample (g), A: Weight after drying sample (g)]

[viscosity]
The viscosity at 30 ° C. is measured with a BM viscometer (manufactured by Tokyo Keiki Co., Ltd .: rotor No. 4).
[PH]
It is measured with a pH meter (PH METER Horiba, Ltd.).
[specific gravity]
Samples and test equipment are tempered to 25 ° C ± 5 ° C. The weight of the cup with an internal volume of 105 ml is weighed with a direct balance. Carefully fill the cup with sample to avoid air bubbles and level the surface along the edges of the cup. The weight after sample filling is weighed with a direct balance and the specific gravity is determined by the following calculation.
Specific gravity = (B−A) / C
A: Weight of cup (g)
B: Weight of cup after sample filling (g)
C: 105 (g)
(Weight of water when filling a 105ml cup with water)

[Stirring stability]
250 g of each coating agent is put in a commercially available polypropylene container (250 ml) and kept at 40 ° C. The coating agent is stirred with a stirrer, and the time until the coating agent thickens and gels is measured. Gels with a gelation time of 60 minutes or less were indicated as x, those having a time of 1 hour to 4 hours or less as Δ, and those above 4 hours as ◯.
[Sag of coating agent]
5mm diameter and 50cm long rebars are vertically immersed using water that has been diluted by adding water to each coating agent so that it has a predetermined film thickness (150μm). I checked the sex. The case where there was little sagging was indicated as ◯, the case where there was a slight sagging was indicated as Δ, and the case where the sagging was significant was indicated as x.

[Uniformity of coating film]
Each coating agent was diluted by adding water to adjust the viscosity so as to have a predetermined film thickness of 150 μm, and 5 mm diameter and 20 cm long reinforcing bars were subjected to vertical dip coating and horizontal dip coating. Next, after baking this at 100 ° C. for 10 minutes, the coating thickness was measured and the appearance was inspected to check the uniformity of the coating. And, the film with good uniformity of the coating film ◎, the film with almost uniform coating film ◯, the film with a thin film thickness portion △, the coating film is too thin, Those where the surface of the material was seen were indicated as x.
[Base material adhesion]
The coating agent is applied to a commercial mild steel plate with a 10 mil applicator and then dried at 100 ° C. for 10 minutes. The surface of the coating film is cut into a 4 mm square × 25 with a cutter, the gum tape is strongly attached and peeled off, and the residual ratio of the coating film is measured. Those with a residual rate of 95 to 100% are indicated as ◎, those with 90 to 95% as ○, and those with 85 to 90% as Δ.

[Coating hardness]
Using the test piece prepared in the above-described uniformity test of the coating film, the coating film hardness was evaluated by touch. Then, “A” indicates that there is no tackiness, “A” indicates that the thick film portion has a slight tackiness, and “Δ” indicates that there is a little tackiness overall.
[Rust prevention]
A salt spray test was performed in accordance with JIS K 5400 using the test piece prepared in the uniformity test of the coating film, and the rusting state after 10 days was observed. ◎ where rusting is hardly seen, slightly rusting is seen, 略 is almost good, △ is partially rusting, overall rusting is noticeable Was displayed as x.

  As shown in Table 1, water-based polymers (A-1 and A-2) obtained by emulsion polymerization using specific emulsifiers and specific granular hot-melt organic fillers (B-1 to B-5) ) And the coating agents of Examples 1 to 5 are excellent in each performance. On the other hand, the coating agents of Comparative Examples 1 to 3 using aqueous polymers (X-1 to X-3) obtained by emulsion polymerization using an emulsifier that does not correspond to the constituent requirements of the present invention are stable in stirring. The property is remarkably inferior. The coating agents of Comparative Examples 4 and 5 using granular hot-melt organic fillers (Y-1 and Y-2) that do not correspond to the constituent requirements of the present invention are sagging or difficult to apply uniformly. It was confirmed that

Claims (5)

(A) an aqueous polymer obtained by emulsion polymerization using a nonionic emulsifier,
(B) an aqueous resin dispersion comprising a granular hot-melt organic filler,
The nonionic emulsifier is a polyoxyethylene styrenated phenyl ether having a styrenated phenyl group and an HLB of 16 or more,
(B) The granular heat-fusible organic filler has an average particle diameter of 0.1 μm to 0.5 μm, and is an aqueous resin dispersion. The aqueous resin dispersion according to claim 1, wherein the nonionic emulsifier is a polyoxyethylene styrenated phenyl ether having an HLB of 17.5 to 19.0.   A coating agent comprising the aqueous resin dispersion according to claim 1.   The coating agent of Claim 3 used as a rust preventive agent.   A building base material to which the coating agent according to claim 3 or 4 is applied.