JP2013023542A - Rust preventive coating, method for forming coating film, and coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rust preventive coating having good rust preventiveness, a method for forming a coating film in which an article to be coated is coated with the rust preventive coating to form the coating film, and a coated article having good corrosion resistance obtained by coating the article with the rust preventive coating.SOLUTION: The rust preventive coating contains: a powdery alloy containing zinc and a metal other than zinc; scale-like silica; a surfactant having an HLB of 6-17, which is at least one selected from the group consisting of a polyoxyethylene alkylamine, a polyoxyethylene alkyl ether, a polyoxyethylene distyrenated phenyl ether, a polyoxyethylene sorbitan fatty acid ester, and a sorbitan fatty acid ester; and water. The mass ratio of the scale-like silica to the alloy is preferably 0.013-0.18. The rust preventive coating preferably contains an electroconductive pigment.

Description

  The present invention relates to a rust preventive paint containing a zinc alloy, a method of forming a paint film by coating the rust preventive paint on an object to be coated, and a coating formed by applying the rust preventive paint to an object to be coated. It relates to goods.

Since metal materials such as steel materials are oxidized and corroded by oxygen and moisture in the atmosphere, it is necessary to coat and protect the surfaces by applying various types of plating or coating materials.
Examples of the paint include rust preventive paints containing zinc and aluminum as metal pigments. Since zinc and aluminum have a higher ionization tendency than iron, they elute prior to iron, and an effect of suppressing corrosion of iron (sacrificial anticorrosive action) is obtained.

Patent Document 1 discloses that after coating an object to be coated with an alkyl silicate-based high-concentration zinc powder coating containing zinc dust, an alkyl silicate, and a solvent such as ethylene glycol monoethyl ether having a boiling point of 156 ° C., the coating film is made into a base. An invention of a coating film curing method for treating with an aqueous substance-containing aqueous liquid is disclosed. According to the present invention, the hydrolysis and dehydration condensation reaction of the alkyl silicate is promoted by the basic substance-containing aqueous liquid, and the curing of the coating film is promoted.
In Patent Document 2, an alkyl silicate, an alcohol containing isobutyl alcohol having a boiling point of 108 ° C., water, and a solution containing hydrochloric acid are reacted to prepare an alkyl silicate hydrolysis initial condensate, and then zinc dust is added to the anticorrosion paint. And an anticorrosion coating method for applying the anticorrosion paint on the surface of a steel material as a primer is disclosed.
Patent Document 3 discloses an invention of a rust-preventing primer which contains a partially hydrolyzed and condensed alkyl silicate, zinc powder, and a thickener.
Patent Document 4 discloses an invention of a water-diluted coating composition containing a high-boiling organic liquid having a boiling point exceeding about 100 ° C. at atmospheric pressure, a particulate metal, a thickener, and a silane binder. That is, it is disclosed that water that hydrolyzes a silane binder is blended with an alkylsilicate-based zinc powder paint.

Patent Document 5 discloses an invention of a coating material made of zinc or a zinc-based alloy such as Zn-10% Al-0.1% Mg containing zinc as a main component and containing a flake-like metal powder and a liquid medium. Has been. According to the present invention, the metal powder is flaked to increase the specific surface area, so that the contact between the metal powders becomes close, and in addition to the active anticorrosive property of the metal itself, the protective barrier based on the flake shape An effect (passive anticorrosion) is also obtained, the content of the metal powder can be reduced, and the occurrence of cracks in the coating film can be suppressed.
Patent Document 6 discloses an invention of a metal powder made of an alloy of zinc and aluminum and used for mechanical plating. Rust prevention is improved by alloying aluminum with zinc, but the adhesion of the coating film is worse than with zinc alone. According to this invention, by setting the zinc content in the alloy to about 50% by mass or more, it is possible to have both good rust prevention and adhesion of the coating film.
In Patent Document 7, as in the inventions of Patent Documents 5 and 6, a metal powder made of an alloy of zinc and a non-zinc metal containing 50% by mass or more of zinc and having a flake shape as in the invention of Patent Document 5 The invention of the coating material which has favorable rust prevention property is disclosed by using this with a liquid medium.

Patent Document 8 contains at least one particulate metal and at least one binder in a liquid medium composed of water, a glycol compound and / or an organic solvent, and the particulate metal with respect to the sum of the particulate metal and the binder. The total amount of zinc and aluminum is 70 mass% or more, and the granular metal is an aluminum having a content of less than 4 mass% with respect to the granular metal, and a zinc having a content of 50 mass% or more. An invention of a corrosion-resistant coating composition for a screw configured to contain a zinc alloy whose content is 100% by mass or less with respect to the granular metal is disclosed.
Patent Document 9 includes approximately 20 to 70% by mass of water, a low-boiling organic liquid, a granular metal, an alkoxy group, and approximately 3 to 20% by mass of a silane binder and a wetting agent that are water-soluble. In addition to corrosion resistance, an invention of a coating composition having a desired coating tackiness on an object to be coated is disclosed.

JP-A-55-108473 JP-A-6-31245 JP-A-7-228801 Japanese Patent No. 3904669 Japanese Patent Laid-Open No. 61-123684 JP-A-55-119101 Japanese Patent No. 4198919 JP 2006-52361 A JP 2002-121485 A

In the inventions of Patent Documents 5 to 8, good rust prevention is obtained by using a zinc-aluminum alloy instead of the zinc powder of Patent Documents 1 to 4 as the metal powder of the pigment, and the invention of Patent Document 9 In No. 1, good coating adhesiveness is obtained by containing approximately 3 to 20% by mass of a silane binder in the coating composition, but further improvement in rust prevention is required. For example, it is required that red rust does not occur in a coated article in which a coating film is formed on a base material made of steel after 1000 hours have passed in a salt spray test.
In addition, it is necessary to form a coating film even on the surface of products that are used in combination with parts of different metals and have complicated shapes, such as bolts, nuts, washers, etc. The alloy must be uniformly dispersed.

  The present invention has been made in view of such circumstances, a rust-preventing paint having a good rust-preventing property, a method of forming a coating film by coating the rust-preventing paint on an article to be coated, and An object of the present invention is to provide a coated article having a good corrosion resistance, which is obtained by painting a rust preventive paint on an object to be coated.

As a result of diligent research, the present inventors applied zinc and an alloy containing a metal other than zinc in addition to scaly silica to prepare an anticorrosive paint, thereby coating the anticorrosive paint on an object to be coated. Thus, when the coating film is formed, the corrosion resistance is remarkably improved, and the present invention has been completed.
That is, the anticorrosive paint according to the first invention includes zinc, a powdered alloy containing a metal other than zinc, scaly silica, polyoxyethylene alkylamine, polyoxyethylene alkyl ether, polyoxyethylene distyrenation. It is at least one selected from the group consisting of phenyl ether, polyoxyethylene sorbitan fatty acid ester, and sorbitan fatty acid ester, and contains a surfactant having an HLB of 6 to 17 and water. .

  The rust preventive paint according to the second invention is characterized in that, in the first invention, it contains a conductive pigment.

  In the first or second invention, the anticorrosive paint according to the third invention is at least one selected from the group consisting of an epoxy group, a methacryloxy group, an acryloxy group, an amino group, a mercapto group, and a vinyl group in the molecule. A silane coupling agent having a functional group and a hydrolyzable silicon group; and a silane compound having a hydrolyzable silicon group in the molecule and not containing the functional group of the silane coupling agent. Features.

  A coating film forming method according to a fourth aspect of the present invention is characterized in that a coating film is formed by applying a rust preventive paint according to any one of the first to third aspects of the invention to an article to be coated.

  A coated article according to a fifth aspect of the present invention is characterized in that an article to be coated is coated with the rust preventive paint according to any one of the first to third aspects of the invention.

Since the rust preventive paint of the present invention contains scaly silica in addition to the zinc alloy, it has good rust preventive properties. This is because scaly silica is oriented in a laminated state in the coating film, so that the penetration of corrosive gases and corrosive substances into the coating film is blocked, and the film-forming ability of the coating film is improved and mechanical. This is thought to be due to improved physical properties.
And since it contains the above-mentioned surfactant, a zinc alloy can disperse | distribute well to water and a coating film can be formed uniformly on a to-be-coated article.

  Since the anticorrosive paint of the present invention contains a conductive pigment, the conductivity of the coating film is improved, the sacrificial anticorrosive action of zinc is smoothly generated, and the antirust paint has good antirust properties.

  Since the rust preventive paint of the present invention contains the above-mentioned silane coupling agent, silanol groups are generated by hydrolysis, and the silanol groups are bonded to the zinc alloy, so that the zinc alloy is stabilized in the rust preventive paint. At the time of forming the coating film, the silanol group is bonded to the object to be coated and the zinc alloy, and cross-linking and the like are caused by the functional group, thereby improving the adhesion of the coating film. And since it contains the above-mentioned silane compound, since a silanol group is easy to produce by hydrolysis and a silanol group couple | bonds with a zinc alloy, a zinc alloy is stabilized in a rust-proof coating material. Since the silanol group is bonded to the article to be coated and the zinc alloy at the time of forming the coating film, the adhesion of the coating film is also improved.

  In the coating film forming method of the present invention, a coating film is formed by applying the rust preventive paint of the present invention to an object to be coated, so that the obtained coated article has good corrosion resistance.

  Since the coated article of the present invention is formed by coating the article to be coated with the rust preventive paint of the present invention, it has good corrosion resistance.

  According to the present invention, since the rust preventive paint contains scaly silica in addition to the zinc alloy, the rust preventive property is improved, and the coated article formed by coating the rust preventive paint has good corrosion resistance. .

  The anticorrosive paint according to the present invention comprises zinc and a powdered alloy containing a metal other than zinc (hereinafter referred to as zinc alloy), scaly silica, polyoxyethylene alkylamine, polyoxyethylene alkyl ether, polyoxy It contains at least one surfactant selected from the group consisting of ethylene distyrenated phenyl ether, polyoxyethylene sorbitan fatty acid ester, and sorbitan fatty acid ester, and an HLB of 6 to 17 and water.

The zinc alloy powder is preferably flaky. By making it into flakes, the specific surface area increases, the contact between the powders becomes close, and in addition to the active corrosion resistance of the metal itself, a protective barrier effect (passive corrosion resistance) based on the flake shape is also obtained. The content of the zinc alloy powder can be reduced, and the occurrence of cracks in the coating film can be suppressed.
Examples of metals other than zinc include aluminum, magnesium, tin, cobalt, and manganese. Among these, it is preferable that aluminum is contained in the alloy from the viewpoint of obtaining a good sacrificial anticorrosive action and being relatively inexpensive. One or two or more metals other than zinc can be used. For example, a zinc-aluminum-magnesium alloy or the like can be used as an alloy of three metals.

  Zinc is preferably contained in the zinc alloy in an amount of 50% by mass or more, more preferably 80% by mass or more, and still more preferably 85% by mass or more from the viewpoint of rust prevention, adhesion to an object to be coated, and cost.

It is preferable to use a zinc alloy in the form of a paste. Examples of the paste liquid include dipropylene glycol and mineral spirit.
The zinc alloy is preferably contained in the zinc alloy paste at approximately 90 to 95% by mass.
And when a zinc alloy is a zinc-aluminum alloy, it is preferable that a zinc alloy paste contains about 85-90 mass% zinc and about 3-8 mass% aluminum, and the remainder is a paste liquid.
As a specific example of the zinc alloy paste, “STAPA 4 ZnAl7” (Zn: 85% by mass, Al: 7% by mass, mineral spirit: 8% by mass), which is a Zn—Al alloy paste manufactured by Eckart, STAPA 4 ZnAl3 ”(Zn: 89 mass%, Al: 2.5 mass%, mineral spirit: 8.5 mass%) and the like. Regarding particle size, it is preferred that at least about 50% by weight of the particles have the longest dimension of less than about 15 microns.

  The anticorrosive paint of the present invention may contain a powdery single metal (flakes or non-flakes) in addition to the zinc alloy. For example, an aluminum paste containing flaky aluminum can be contained.

In the scale-like silica, the primary particles have a scale plate shape, have low crystallinity, and are excellent in properties such as spreadability, orientation, and concealment. The primary particles are composed of, for example, a scaly plate having a thickness of 0.001 to 1 μm, the ratio of the longest length of the scaly plate to the thickness (aspect ratio) is at least 10, and the minimum of the scaly plate relative to the thickness The length ratio is at least 3. The scaly primary particles agglomerate to form secondary particles, whereby self-forming properties are obtained.
Specific examples of the product containing scaly silica include “Sun Lovely LFS HN050” manufactured by AGC S-Itech Co., Ltd. This is prepared as a 15% aqueous solution of scaly silica.

Since the scaly silica has a flat flake shape with a high aspect ratio, the particles are aligned in the binder and substantially parallel to the surface of the substrate during coating and film formation. They are close to each other and densely stacked to form a fine composite structure.
Since the scaly silica is oriented in a laminated state in the coating film, the penetration of corrosive gases such as oxygen and corrosive substances is effectively blocked at the particle level. In addition, since scaly silica has a self-forming property, the film forming ability of the silane coupling agent is strengthened by blending it with a rust-preventing paint, and the mechanical properties of the resulting coating film are improved. Performance such as property, crack prevention and pinhole prevention. Therefore, the corrosion resistance of the coating film is improved.

  The mass ratio (effective component ratio) of the scaly silica to the zinc alloy is preferably 0.013 or more and 0.18 or less from the viewpoint of obtaining rust prevention properties and good storage stability. The lower limit is more preferably 0.05, and the upper limit is more preferably 0.1, still more preferably 0.09.

  The polyoxyethylene alkylamine as the above-mentioned surfactant is represented by the general formula of the following formula (1).

However, a = 1, 2, ...
b = 1, 2,
R = C _n H _{2n + 1}
n = 1, 2,

The polyoxyethylene alkyl ether is represented by the general formula of the following formula (2).
_{RO- (CH 2 CH 2 O)} n -H ··· (2)
n = 1, 2,
R = C _m H _{2m + 1}
m = 1, 2,

  Polyoxyethylene distyrenated phenyl ether is represented by the following general formula (3).

  However, n = 1, 2, ...

  The polyoxyethylene sorbitan fatty acid ester is represented by the following general formula (4).

However, a = 1, 2, ...
b = 1, 2,
c = 1, 2,
R = C _n H _{2n + 1}
n = 1, 2,

  Sorbitan fatty acid ester is represented by the following general formula (5).

However, R = C _n H _{2n + 1}
n = 1, 2,

By containing the surfactant, the dispersibility of the zinc alloy in water is improved.
From the viewpoint that this effect is effectively exhibited, the mass ratio of the surfactant to the zinc alloy is preferably 0.01 or more and 0.3 or less, and more preferably 0.01 or more and 0.2 or less. . Although the HLB is considered when determining the type and combination of surfactants, the preferred HLB range varies depending on the type and combination of surfactants, as will be described later, so it corresponds to the type and combination of surfactants. A surfactant with HLB is selected.

The rust preventive paint of the present invention preferably contains a conductive pigment.
Examples of the conductive pigment include a rutile type or anatase type titanium oxide used as a base material, a coating layer having tin oxide containing antimony formed on the surface of the base material, and a white color. The ratio of the coating layer in the pigment is preferably 8 to 22%. The antimony content of the coating layer is preferably 1.0 to 10.0%.
As a specific example of this conductive pigment, a product “W-1” manufactured by Mitsubishi Materials Electronic Chemical Co., Ltd. may be mentioned.

In addition, as an antimony-free conductive pigment that has little impact on the environment, a conductive layer containing tin oxide is formed on the surface of a substrate made of titanium oxide or potassium titanate, and an alkyl group is formed on the conductive layer. What formed the surface treatment layer containing the organic silane compound which consists of a containing silane compound and / or a fluorine-containing organic silane compound is mentioned.
When the organic silane compound is an alkyl group-containing silane compound, it preferably has an alkyl group and an alkoxy group. From the viewpoint of expression of the conductive effect, the alkyl group preferably has 1 to 10 carbon atoms, and the alkoxy group is more preferably a methoxy group, an ethoxy group, a propoxy group, or an isopropoxy group.
When the organosilane compound is a fluorine-containing organosilane compound, it preferably contains a partially fluorinated alkyl group and an alkoxy group. From the viewpoint of expression of the conductive effect, the partially fluorinated alkyl group preferably has 2 to 16 carbon atoms.

The conductive layer of the conductive pigment is preferably 5 to 40% based on the total amount of the base material and the conductive layer. The surface treatment layer is preferably 6 to 18 mmol with respect to 100 g of the total mass of the base material and the conductive layer.
As a specific example of this conductive pigment, a product “W-4” manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd. may be mentioned.

By including a conductive pigment in the rust preventive paint, the conductivity of the coating is improved, zinc becomes an anode, a reaction of Zn → Zn ²⁺ + 2e ⁻ occurs, and electrons are supplied to iron to The sacrificial anticorrosive action which prevents elution will occur smoothly and rust prevention will improve.
The mass ratio of the conductive pigment to the zinc alloy (active ingredient) is preferably 0.04 or more and 0.47 or less from the viewpoint of obtaining rust preventive properties and good storage stability. The lower limit is more preferably 0.15, still more preferably 0.22, and the upper limit is more preferably 0.3.

The anticorrosive paint of the present invention has at least one functional group selected from the group consisting of an epoxy group, a methacryloxy group, an acryloxy group, an amino group, a mercapto group, and a vinyl group in the molecule and a hydrolyzable silicon group. It preferably contains a silane coupling agent.
The hydrolyzable silicon group is not particularly limited, but an alkoxysilyl group is preferable from the viewpoint of handleability, and a methoxysilyl group and an ethoxysilyl group are particularly preferable from the viewpoint of reactivity.

As a silane coupling agent, when an epoxy group is included as a functional group, for example, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxy Examples include silane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like.
When a methacryloxy group is included as a functional group, for example, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. may be mentioned. .
When an acryloxy group is included as a functional group, for example, 3-acryloxypropyltrimethoxysilane and the like can be mentioned.

When an amino group is included as a functional group, for example, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (amino Ethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl -3-aminopropyltrimethoxysilane and the like.
When a mercapto group is included as a functional group, for example, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned.
When a vinyl group is included as a functional group, for example, vinyltrimethoxysilane, vinyltriethoxysilane and the like can be mentioned.

  From the viewpoint of improving the coating properties and stabilizing the coating composition, the silane coupling agent preferably has an alkyl group containing an epoxy group as a functional group, particularly an alkyl group containing a glycidoxy group.

The silanol group is generated by the hydrolysis of the silane coupling agent, and the silanol group is bonded to the zinc alloy. Therefore, it is considered that the zinc alloy is stabilized in the rust preventive coating. The silanol group is bonded to the object to be coated and the zinc alloy, and the coating component is cross-linked or chemically bonded by the functional group, thereby improving the adhesion of the coating film.
Since the rust preventive paint of the present invention contains scaly silica, the strength of the coating film is increased and the content of the silane coupling agent can be reduced. From the viewpoint of good adhesion of the coating film and storage stability of the paint, the mass ratio of the silane coupling agent to the zinc alloy is preferably 0.01 or more and 0.9 or less, more preferably 0.2 or more and 0. 0.8 or less, more preferably 0.25 or more and 0.8 or less.

The rust-preventing paint of the present invention preferably further contains a silane compound having a hydrolyzable silicon group in the molecule and not containing the functional group of the silane coupling agent.
The hydrolyzable silicon group is not particularly limited, but an alkoxysilyl group is preferable from the viewpoint of handleability, and a methoxysilyl group and an ethoxysilyl group are particularly preferable from the viewpoint of reactivity.
And it has the haloalkyl group etc. which substituted the alkyl group which does not contain the functional group of a silane coupling agent, a phenyl group, or a part or all of the hydrogen atom with the halogen atom.
Examples of the silane compound include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, and decyltrimethoxysilane. And trifluoropropyltrimethoxysilane.
This silane compound is likely to be hydrolyzed to form silanol groups, and the silanol groups are bonded to the zinc alloy, so that the zinc alloy is considered to be stabilized in the anticorrosive paint. Since the silanol group is bonded to the article to be coated and the zinc alloy at the time of forming the coating film, the adhesion of the coating film is also improved.
From the viewpoint of expression of this effect and the storage stability of the paint, the mass ratio of the silane compound to the zinc alloy is preferably 0.01 or more and 0.9 or less, more preferably 0.05 or more and 0.6 or less.

  The rust preventive paint of the present invention can contain an appropriate amount of water depending on the method of coating, the film thickness of the coating film, the baking conditions, etc., but 25% by weight or more and 90% by weight in the rust preventive paint. % Or less, preferably 50% by mass or more and 80% by mass or less. In addition to the organic liquid contained as a paste liquid in the zinc alloy paste, an organic liquid can be contained in the anticorrosive paint. For example, an acid such as acetic acid can be used as the organic liquid.

The anticorrosive paint of the present invention can be obtained by mixing and stirring each component according to a normal production method. At that time, in addition to the above-described components, paint additives such as a wetting and dispersing agent, a wetting agent, an antifoaming agent, a thickening agent, and a pH adjusting agent may be blended. For example, wetting agents such as polycarboxylic acid-based wet dispersing agents, organic phosphate esters, diester sulfosuccinates such as sodium bistridecyl sulfosuccinate, silicone-based or acrylic-based additives, which are general paint additives An antifoaming agent etc. can be mix | blended.
Examples of thickeners include hydroxyethyl cellulose, methyl cellulose, methyl hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, methyl ethyl cellulose ethers, and mixtures of these substances. Other thickeners include xanthan gum, urethane-based associative thickeners, and nonionic associative thickeners that do not contain urethane.
Examples of pH adjusters include alkali metals such as lithium and sodium (Group IA), alkaline earth metals such as strontium, calcium, barium and magnesium (Group IIA), and oxides of metals such as Group IIB such as zinc and cadmium. From the viewpoint that the coating bondability can be enhanced, oxides and hydroxides of alkali metals such as lithium and sodium are preferable. Moreover, the above-mentioned metal carbonate or nitrate may be sufficient.

  The anticorrosive paint of the present invention may contain a boron compound such as orthoboric acid, metaboric acid, tetraboric acid, boron oxide, and zinc borate. Further, phosphate, calcium nitrate, dibasic ammonium phosphate, aluminum tripolyphosphate, calcium sulfonate, 1-nitropropane, lithium carbonate (also used as a pH adjusting agent) and the like may be contained.

  Since the rust preventive paint according to the present invention contains the above-mentioned silane coupling agent and silane compound, when coated with the rust preventive paint, the adhesion between the zinc alloy and the object to be coated is good, and chromic anhydride It is not necessary to contain a water-soluble chromium compound such as sodium chromate, potassium chromate, sodium dichromate or potassium dichromate. Therefore, there is no environmental problem.

Below, the method of forming a coating film in a to-be-coated article using the rust preventive paint of this invention is explained in full detail.
The article to be coated with the anticorrosive paint of the present invention is not particularly limited, and may be a ceramic article or the like, but is suitable for an article made of an iron-based material such as steel. Can be painted. The object to be coated with the iron-based material may be in the form of an alloy or an intermetallic mixture.
Examples of the iron-based material to be coated include all products using iron-based materials, such as chains, gears, speed reducers, and linear cylinder bodies or cases. As a chain, a pair of outer plates connected by two pins and a pair of inner plates connected by two bushes are alternately connected with the pins loosely fitted to the bushes. Is mentioned. The anticorrosive paint of the present invention can also be suitably applied to automobile bolts, nuts, washers, pins, screws, and the like that may be exposed to water.

It is preferable to remove foreign substances from the substrate surface by washing and / or degreasing the object to be coated. Degreasing can be performed, for example, with hexane or the like. Moreover, you may use the well-known chemical | medical agent containing a metasilicate, caustic soda, carbon tetrachloride, trichloroethylene, etc.
And as a process of the surface of a to-be-coated object, you may decide to perform the shot blast process which spouts a shot (small steel ball) toward this surface with high-pressure air, and touches this surface and finishes the surface. Furthermore, the base film may be formed on the surface of the object by plating with zinc or a zinc alloy.

  The anticorrosive paint of the present invention can be applied to an object by immersion treatment such as immersion drain (dip drain) and immersion rotation (dip spin), brush coating, spraying, or the like.

  After applying the rust preventive paint of the present invention to the article to be coated, it is preferable to heat cure the rust preventive paint. It is preferable to evaporate the volatile component of the anticorrosive paint in advance by drying before curing. The drying temperature is preferably about 100 ° C to 180 ° C. The drying time is preferably about 2 to 25 minutes.

  Heat curing of the anticorrosive paint can be performed by high temperature air oven curing, but infrared baking and induction curing can also be employed. The heat curing can be performed in a range of approximately 280 ° C to 370 ° C. The curing time is approximately 10 minutes to 45 minutes.

From the viewpoint of the development of good corrosion resistance and cost, the coating amount of the object to be coated is preferably 5 g / m ^{2 to} 100 g / m ² , more preferably 10 g / m ^{2 to} 50 g / m ² , and even more preferably 12 g / m. ^{2 to} 40 g / m ² .

The anticorrosive paint of the present invention may be applied to an object to be coated a plurality of times.
Further, it may be overcoated using another top coating material. Examples of the top coat include those containing a silane compound such as silicate and silicate ester, colloidal silica and the like.

  In the rust preventive paint of the present invention configured as described above, the zinc alloy is well dispersed in water, the rust preventive paint has a good rust preventive property, and the rust preventive paint is applied to an object to be coated. The resulting coated article has good corrosion resistance.

  Hereinafter, although an example and a comparative example of the present invention are explained concretely, the present invention is not limited to this example.

1. Examination of surfactants We investigated surfactants added to disperse zinc alloys well in anti-corrosion paints.
The surfactants studied are as follows.
Polyoxyethylene alkylamine of the above formula (1) Trade name “Zontes AL” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)
Product name "Amate 105" (manufactured by Kao Corporation)
Product name "AMIET 102" (manufactured by Kao Corporation)

Polyoxyethylene alkyl ether of the formula (2) Trade name “Marpon ACF-12” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)
Product name “Marpon ACF-9” (Matsumoto Yushi Seiyaku Co., Ltd.)
Product name "Marpon B-9W" (Matsumoto Yushi Seiyaku Co., Ltd.)
Product name "Marpon ACF-7" (Matsumoto Yushi Seiyaku Co., Ltd.)
Product name "Marpon B-5" (Matsumoto Yushi Seiyaku Co., Ltd.)
Product name “Emulgen 106” (manufactured by Kao Corporation)
Product name “Emulgen 102KG” (manufactured by Kao Corporation)

Polyoxyethylene distyrenated phenyl ether of the formula (3) Trade name “Emulgen A-60” (manufactured by Kao Corporation)
Product name "Emulgen A-90" (manufactured by Kao Corporation)

Polyoxyethylene sorbitan fatty acid ester of the formula (4) Trade name “Leodol TW-S106V” (manufactured by Kao Corporation)
Product name "Leodoll TW-L120" (manufactured by Kao Corporation)

Sorbitan fatty acid ester of the formula (5) Trade name “Leodol SP-L10” (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.)

  The HLB of each surfactant is shown in Tables 1 to 3 below.

[Formulation Example 1]
According to the composition (shown in parts by mass) in Table 1, water, a surfactant (said “Zontes AL”), and a Zn—Al alloy paste (said “STAPA 4 ZnAl7”, manufactured by Ecart) were stirred at room temperature for 1 hour. By mixing, the composition of Formulation Example 1 was obtained.
[Composition Examples 2 to 10]
In accordance with the composition shown in Table 1, the compositions of Composition Examples 2 to 10 were obtained in the same manner as Formulation Example 1. [Composition Example 11]
A composition of Formulation Example 11 was obtained in the same manner as Formulation Example 1 except that the surfactant was not added.

[Composition Examples 12-16]
In accordance with the formulation shown in Table 2, the formulations were obtained in the same manner as in Formulation Example 1 except for Formulation Examples 12-16.

[Composition Examples 17-24]
According to the formulation shown in Table 3, two or three surfactants were used, and the compositions of Formulation Examples 17 to 24 were obtained in the same manner as Formulation Example 1. In addition, in the blending examples 17-24, it mix | blends in order of water, surfactant, zinc alloy, and water, and mix | blends water twice.

[Evaluation of dispersibility]
The dispersibility in the composition of the Zn-Al alloy after preparation of the composition was evaluated as follows.
A ... very good B ... good C ... bad D ... zinc alloy repels water This evaluation result is shown in the said Tables 1-3.

From Table 1, it can be seen that in the case of the polyoxyethylene alkylamine of the formula (1), any surfactant exhibits good dispersibility (HLB 6.3 to 9.5).
In the case of the polyoxyethylene alkyl ether of the formula (2), “Marpon ACF-9” showing the same HLB13.3 has a dispersibility evaluation of C, and “Marpon B-9W” has an evaluation of B. “Marpon ACF-7” of HLB12.1 is also rated B, “Marpon B-5” and “Emulgen 106” of HLB10.9 and 10.5 are both rated A, and “ "Emulgen 102KG" is rated C. Therefore, in the case of polyoxyethylene alkyl ether, it is guessed that HLB10-13 is preferable and HLB10-11 is more preferable.

From Table 2, when the surfactants of formulas (3) to (5) (polyoxyethylene distyrenated phenyl ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester) are used alone, “Emulgen A-60” It can be seen that only (HLB12.8) is evaluation B, and the other surfactant is evaluation C.
From Table 3, dispersibility does not improve even if two surfactants of formula (3) and two surfactants of formula (4) are mixed, and the surfactants of formulas (4) and (5) It was confirmed that the evaluation was B when HLB13 to 15 was mixed and the evaluation was A when the surfactant of formula (2) was further mixed to HLB13.6.
When a rust preventive paint is prepared using a surfactant having a dispersibility evaluation of B or higher, it is considered that the zinc alloy is well dispersed in any rust preventive paint.

2. Preparation of rust preventive paint [Example 1]
In accordance with the formulation (shown in parts by mass) shown in Table 4 below, a Zn-Al alloy paste (said “STAPA 4 ZnAl7”), n-hexyltrimethoxysilane (“HTS-M” manufactured by JNC Corporation), a surfactant ( “Zontes AL” manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), wetting and dispersing agent, conductive pigment (1) (“W-1” manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.), scaly silica aqueous solution (“Sunlabry”) LFS HN050 "), acetic acid, silane coupling agent (" S510 "manufactured by JNC Corporation, 3-glycidoxypropyltrimethoxysilane), water, thickener (" BYK-425 "manufactured by Big Chemie Japan Co., Ltd.), urethane System thickener (rheology control agent))), antifoaming agent ("BYK-011" manufactured by Big Chemie Japan KK), and wetting agent at 4 o'clock By mixing stirring, to obtain anticorrosive coating compositions of Examples 1.

  In Table 4, “flaky silica / alloy”, “conductive pigment / alloy”, “n-hexyltrimethoxysilane / alloy”, and “silane coupling agent / alloy” are respectively scaly silica (flaky) Active component of silica aqueous solution), conductive pigment, n-hexyltrimethoxysilane, mass ratio of silane coupling agent to Zn-Al alloy (effective component of Zn-Al alloy paste, 92% of Zn-Al alloy paste) ( %).

[Examples 2 to 9]
According to the composition of Table 4, the antirust paints of Examples 2 to 9 were obtained in the same manner as Example 1. In Table 4, the conductive pigment (2) is “W-4” manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.

[Comparative Examples 1-3]
N-hexyltrimethoxysilane, conductive pigment, and scaly silica were not added, and the other components were obtained in the same manner as in Example 1 in accordance with the formulation of Table 4 above, thereby obtaining anticorrosive paints of Comparative Examples 1 to 3. It was.

3. Preparation of corrosion-resistant surface-treated bolts After degreasing and shot blasting on the surface of bolts (M8: steel), the rust-preventive paints of Examples 1 to 9 and Comparative Examples 1 to 3 were used for the dip spin method. After coating and drying at 150 ° C. before curing, it was cured at 330 ° C. to form a coating film. Again, painting was performed using the same anticorrosive paint. That is, the coating was performed twice. The coating amount was 200 mg / dm ² .

4). Production of Corrosion Resistant Surface Treated Plate After degreasing the surface of a cold rolled steel sheet (SPCC-SD, manufactured by Nippon Test Panel Co., Ltd., 0.8 mm × 70 mm × 150 mm), Examples 1 to 9 and Comparative Example 1 A coating film was formed by coating with a rust preventive paint of ~ 3 by dip spin method, drying at 150 ° C before curing, and curing at 330 ° C. Again, painting was performed using the same anticorrosive paint. That is, the coating was performed twice. The coating amount was 200 mg / dm ² .

5. Performance evaluation [salt spray test (corrosion resistance evaluation test)]
About the above-mentioned corrosion-resistant surface treatment bolt and corrosion-resistant surface treatment plate, the salt spray test was done based on "JIS-K5600-7-1". The presence or absence of red rust generation after 1000 hours was evaluated as follows. The results are shown in Table 4 above.
A: No red rust occurs B: Red rust occurs

[Summary]
From Table 4, the anticorrosive paints of Examples 1 to 3, which contain silane compounds (n-hexyltrimethoxysilane) other than flaky silica and silane coupling agents, flaky silica, conductive pigments, and the above When the coating film is formed using the anticorrosive paint of Examples 4 to 9 containing the silane compound (the mass ratio of the scaly silica aqueous solution to the Zn-Al alloy is 1.3% to 17%), scaly Corrosion-resistant surface compared to the case where a coating film is formed using the anticorrosive paints of Comparative Examples 1 to 3 that do not contain silica, a conductive pigment, and the silane compound (all of which generate red rust before 500 hours have elapsed). It can be seen that both the treated bolt and the corrosion-resistant surface-treated plate have improved corrosion resistance.
In the case of the anticorrosive paint of Example 3, it has been confirmed that the storage stability is poor compared to other examples. This is probably because the surfactant “Zontes AL” is alkaline, and scaly silica is weak in alkalinity, so that the storage stability is deteriorated by increasing the content of scaly silica. Therefore, the mass ratio of the scaly silica to the Zn—Al alloy is more preferably 5% to 10%.
Similarly, it can be seen that the mass ratio of the conductive pigment to the Zn—Al alloy is preferably 4% to 47%, more preferably 15% to 30%.

As described above, the anticorrosive paint of the present invention containing scaly silica and a conductive pigment has good anticorrosive properties, and a coated article formed by coating the anticorrosive paint on an object to be coated has good corrosion resistance. It was confirmed.
In addition, since the anticorrosive paint of the present invention contains the above-mentioned surfactant, it was also confirmed that the zinc alloy was well dispersed in water and a coating film could be uniformly formed on the surface of the object to be coated.

Claims (5)

A powdered alloy containing zinc and a metal other than zinc; and
Scaly silica,
It is at least one selected from the group consisting of polyoxyethylene alkylamine, polyoxyethylene alkyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene sorbitan fatty acid ester, and sorbitan fatty acid ester, and HLB is 6 or more and 17 A surfactant which is:
An anticorrosive paint characterized by containing water.   The rust preventive paint according to claim 1, further comprising a conductive pigment. A silane coupling agent having in the molecule at least one functional group selected from the group consisting of an epoxy group, a methacryloxy group, an acryloxy group, an amino group, a mercapto group, and a vinyl group, and a hydrolyzable silicon group;
The rust preventive paint according to claim 1, comprising a hydrolyzable silicon group in a molecule and a silane compound not containing a functional group of the silane coupling agent.   A coating film forming method comprising coating a rust preventive paint according to any one of claims 1 to 3 onto an article to be coated to form a coating film.   A coated article obtained by coating the object to be coated with the rust preventive paint according to any one of claims 1 to 3.