JP2023093172A - Aqueous anti-rusting coating composition and manufacturing method - Google Patents

Abstract

To provide an aqueous anti-rusting coating composition excellent in storage stability of coating, and further suitable for forming a coating film excellent in corrosion resistance, and a manufacturing method of the aqueous anti-rusting coating composition.SOLUTION: Provided are an aqueous anti-rusting coating composition containing an aqueous resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins and modified resins thereof is rendered water-based, an emulsifier (B) containing at least one of amphiphilic substance forming a closed vesicle and a polymerizable polymer having a hydroxyl group, and an anti-rusting pigment (C), and a manufacturing method of the aqueous anti-rusting coating composition.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a water-based rust preventive coating composition and a method for producing the water-based rust preventive coating composition.

Metal members used in buildings, civil engineering structures, ships, industrial products, etc. are coated with antirust paints for the purpose of preventing the generation of rust. Organic solvent-based paints used to be the mainstream of rust-preventive paints, but in recent years there has been a shift from organic solvent-based to water-based paints in terms of environmental conservation and work environment improvement. things are proposed.

Many water-based antirust paint compositions contain a waterborne resin and an antirust pigment. A water-based resin is a component that can be diluted with water to form a coating film, and an antirust pigment is a pigment that is added to paints for the purpose of protecting metals from corrosion by providing some kind of resistance to corrosive factors of metals. be. As an example of a water-based rust preventive paint composition, for example, Patent Document 1 discloses a water-based rust preventive paint composition containing a water-based resin having one or more carboxyl groups in one molecule, a water-based epoxy resin, and a rust-preventive pigment. there is

By the way, a three-phase emulsification method is known as an emulsification method for an aqueous composition. The three-phase emulsification method is completely different from the surfactants used in conventional emulsification methods, and is expected to be an emulsification method that utilizes the physical force (van der Waals attraction) of soft hydrophilic nanoparticles ( See Patent Documents 2 to 5, etc.).

WO2019/065939 JP 2006-239666 A JP 2013-216607 A WO2018/135108 Japanese Patent Application Laid-Open No. 2019-26708

In general, water-based antirust coating compositions are inferior in anticorrosion properties to organic solvent-based coatings. For this reason, if the amount of the rust preventive pigment compounded is increased in order to improve the anticorrosion property, a phenomenon occurs in which the storage stability of the paint is greatly reduced. Thus, in conventional water-based antirust paint compositions, paint storage stability and paint film corrosion resistance are in a trade-off relationship, and it has been difficult to achieve both.

An object of the present invention is to provide a water-based rust preventive paint composition which is excellent in paint storage stability and suitable for forming a paint film with excellent corrosion resistance, and a method for producing the water-based rust preventive paint composition. That's what it is.

Water-based resins used in water-based paints have hydrophilic groups such as carboxyl groups, or secure stability in water by the action of surfactants or the like. In addition, many rust-preventive pigments have the property of dissolving in water that enters from the outside such as rainwater, and by eluting metal ions and various ions with chelating power, they exhibit rust-preventing effects on metal surfaces. There are many things. The present inventors have found that in a water-based rust preventive paint composition, metal ions are eluted from the rust preventive pigment in the paint and ionically crosslinked with the water-based resin, impairing the stability of the paint and causing thickening and gelation. Thought.

Accordingly, the present inventors have investigated a method for suppressing ionic cross-linking between an aqueous resin and metal ions. As a result, by applying the three-phase emulsification method to the production of a water-based rust preventive paint composition, the obtained water-based rust preventive paint composition has storage stability even in an extremely unstable state of containing a water-based resin and a rust-preventive pigment. It has been found that the corrosion resistance is remarkably improved, and that the formed coating film is also excellent in anticorrosion properties.

That is, the present invention is characterized by the following items 1 to 10.
Section 1.
A water-based resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins, and modified resins thereof is made water-based;
an emulsifier (B) containing at least one of an amphiphilic substance forming a closed endoplasmic reticulum and a polycondensation polymer having a hydroxyl group;
Antirust pigment (C)
A water-based antirust paint composition containing
Section 2.
Item 2. The water-based antirust coating composition according to Item 1, wherein the water-based resin (A) contains a water-based epoxy resin as a part of its components.
Item 3.
Item 3. The waterproof waterproof according to Item 2, wherein the water-based resin (A) further contains, in addition to the water-based epoxy resin, a water-based resin in which at least one resin selected from acrylic resins, urethane resins and alkyd resins is made water-based. Rust paint composition.
Section 4.
Item 4. The water-based antirust coating composition according to any one of Items 1 to 3, wherein the amphiphilic substance is polyoxyethylene hydrogenated castor oil.
Item 5.
Item 5. The water-based antirust coating composition according to any one of Items 1 to 4, wherein the water-based resin (A) is emulsified and stabilized by the emulsifier (B).
Item 6.
A method for producing the water-based antirust paint composition according to any one of Items 1 to 5,
An aqueous resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins and modified resins thereof is rendered water-based, and has an amphiphilic substance and a hydroxyl group forming a closed vesicle. A method for producing an aqueous antirust coating composition, comprising the step of mixing with an emulsifier (B) containing at least one polycondensation polymer.
Item 7.
Item 7. A method for producing a water-based antirust coating composition according to Item 6, wherein the emulsifier (B) is added to the composition containing the water-based resin (A) under stirring.
Item 8.
A method for producing the water-based antirust paint composition according to any one of Items 1 to 5,
An emulsifier (B) containing at least one of an amphiphilic substance that forms a closed endoplasmic reticulum and a polycondensation polymer having a hydroxyl group is added to water under stirring to obtain a water dilution of the emulsifier (B). a step of obtaining
Water resistant, comprising a step of mixing a water-based resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins, and modified resins thereof has been made water-based, and the water-diluted product. A method for producing a rust coating composition.
Item 9.
Item 9. A method for producing a water-based anticorrosive coating composition according to Item 8, wherein the water-diluted product is added to the composition containing the water-based resin (A) under stirring.
Item 10.
Item 10. The method for producing a water-based antirust coating composition according to any one of items 6 to 9, further comprising a step of heating the emulsifier (B) to a temperature equal to or higher than the melting point or softening point.

According to the present invention, it is possible to provide a novel water-based anticorrosive coating composition that enables both storage stability and anticorrosion properties of the coating film.

FIG. 1 is an image diagram showing the coating state of the water-based rust preventive coating composition of the present invention.

The water-based antirust paint composition of the present invention is a composition containing a water-based resin (A), a specific emulsifier (B) and an antirust pigment (C).

<Aqueous resin (A)>
In the present invention, the water-based resin (A) is used as a coating film-forming component, and at least one organic resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins and modified resins thereof is dispersed in water. Or it dissolves and becomes water-based.

(acrylic resin)
Examples of acrylic resins include resins essentially containing a (meth)acryloyl group-containing compound and containing other vinyl compounds as polymerized units.
Here, a (meth)acryloyl group means an acryloyl group, a methacryloyl group, or both an acryloyl group and a methacryloyl group.

Examples of the (meth)acryloyl group-containing compound include
methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2- Ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tridecyl (meth)acrylate, etc. Linear and branched a (meth)acrylate containing a linear or cyclic alkyl group;
Hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 2,3-dihydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, the hydroxyalkyl (meth)acrylate Compounds obtained by ring-opening polymerization of lactones such as ε-caprolactone to acrylates, and hydroxyl group-containing (meth)acrylates such as monoesters of polyhydric alcohols such as polyethylene glycol mono(meth)acrylate and acrylic acid or methacrylic acid;
Alkoxyalkyl such as N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, methoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, ethoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate ( meth) acrylate; alkoxy group-containing (meth) acrylate such as polyalkylene glycol monoalkoxy (meth) acrylate such as polyethylene glycol monomethoxy (meth) acrylate;
epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate;
Carboxyl group-containing (meth)acrylates such as acrylic acid, methacrylic acid, half esters of hydroxyalkyl (meth)acrylates and acid anhydrides;
carbonyl group-containing (meth)acrylates such as diacetone (meth)acrylamide and acetoacetoxyethyl (meth)acrylate;
γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, β-(meth)acryloxyethyltrimethoxysilane, β-(meth)acryloxyethyltriethoxysilane, γ- (Meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, γ-(meth)acryloxypropylmethyldipropoxysilane, γ-(meth)acryloxybutylphenyldimethoxysilane, γ- (meth)acryloxyalkoxysilanes such as (meth)acryloxypropyldiethylmethoxysilane;
Hydrolyzable silyl group-containing (meth)acrylate;
sulfonic acid group-containing (meth)acrylates such as 2-acrylamido-2-methylpropanesulfonic acid;
Phosphate group-containing (meth)acrylates such as acid phosphooxyethyl (meth)acrylate and phosphoric acid mono-[(2-hydroxyethyl) (meth)acrylic acid] ester;
N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, Nt-butylaminoethyl (meth)acrylate, N,N - amino group-containing (meth)acrylates such as dimethylaminobutyl (meth)acrylate;
(meth)acrylates containing quaternary ammonium bases such as (meth)acryloyloxyethyltrimethylammonium chloride and dimethylaminoethylmethyl methacrylate;
fluoroalkyl (meth)acrylates such as hexafluoroisopropyl (meth)acrylate, perfluorooctylmethyl (meth)acrylate, perfluorooctylethyl (meth)acrylate;
and any combination thereof.

Other vinyl compounds include aromatic vinyl compounds such as styrene and vinyl toluene; vinyl ethers such as cyclohexyl vinyl ether, nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether and t-butyl vinyl ether; allyl ethers such as ethyl allyl ether and hexyl allyl ether; carboxylic acid vinyl esters such as; olefins such as ethylene, propylene and isobutylene; .

The acrylic resin can be polymerized by any known method, for example, solution polymerization followed by aqueous conversion, emulsion polymerization, and the like.

(Epoxy resin)
Examples of the epoxy resin include epoxy group-containing resins containing an epoxy group in the molecule. Examples of epoxy group-containing resins include polyphenols such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A/F type epoxy resin, and novolac type phenol resin, and epihalohydrin such as epichlorohydrin, which are reacted to form glycidyl groups. or an aromatic epoxy resin obtained by further reacting polyphenols with this glycidyl group-introduced reaction product to increase the molecular weight; aliphatic epoxy resin, alicyclic epoxy resin, etc. be done.

Further, the epoxy resin includes a modified epoxy resin made from the epoxy group-containing resin as a raw material. The modified epoxy resin includes a resin substantially free of epoxy groups.
Modified epoxy resins include, for example, epoxy ester resins obtained by reacting epoxy group-containing resins with fatty acids. The fatty acids include those having a structure in which a carboxyl group is bonded to the end of a hydrocarbon chain, and examples thereof include drying oil fatty acids, semi-drying oil fatty acids and non-drying oil fatty acids. Drying oil fatty acids and semi-drying oil fatty acids cannot be strictly distinguished, but in general, drying oil fatty acids are unsaturated fatty acids with an iodine value of 130 or more, and semi-drying oil fatty acids have an iodine value of 100 or more and less than 130. of unsaturated fatty acids. Non-drying oil fatty acids are generally unsaturated fatty acids with an iodine value of less than 100. Drying oil fatty acids and semi-drying oil fatty acids include, for example, fish oil fatty acids, dehydrated castor oil fatty acids, safflower oil fatty acids, linseed oil fatty acids, soybean oil fatty acids, sesame oil fatty acids, poppy oil fatty acids, perilla oil fatty acids, hemp oil fatty acids, grape kernel oil fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, walnut oil fatty acid, rubber seed oil fatty acid, etc. Examples of non-drying oil fatty acids include coconut oil fatty acid, hydrogenated coconut oil fatty acid, , palm oil fatty acid, etc., and these can be used alone or in combination of two or more. In addition, caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, etc. can also be used in combination.

Further, the epoxy resin may be an acrylic-modified epoxy ester resin made from a fatty acid, an epoxy group-containing resin, and a (meth)acryloyl group-containing compound as raw materials.

(urethane resin)
Examples of the urethane resin include resins obtained by reacting diisocyanate, diol, low-molecular-weight polyhydroxy compound and dimethylolalkanoic acid.

Diisocyanates include aliphatic and alicyclic diisocyanates, and diols include polyether diols, polyester diols and polycarbonate diols.

(alkyd resin)
Examples of the alkyd resins include resins obtained by reacting polybasic acids, polyhydric alcohols and, if necessary, drying oil fatty acids and/or semi-drying oil fatty acids.

Examples of polybasic acids include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetrahydrophthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, tetrabromophthalic anhydride, and tetrachlorophthalic anhydride. , Hetic anhydride, Himic anhydride, and other unsaturated polybasic acids; Hexahydroisophthalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, sebacic acid, 1,12-dodecanedioic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid acid, 2,3-naphthalenedicarboxylic anhydride, 4,4′-biphenyldicarboxylic acid, and saturated polybasic acids such as dialkyl esters thereof;

Polyhydric alcohols include diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 2-methyl-1,3-propanediol, 1,3-butanediol, neopentyl glycol, 1,4 -butanediol, 1,6-hexanediol, 1,9-nonanediol, bisphenols or adducts of bisphenols and alkylene oxides, 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane, 1, 3-propanediol, 1,2-cyclohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, 1,4-cyclohexanedimethanol, paraxylene glycol, bicyclohexyl-4,4′-diol, 2, 6-decalin glycol, 2,7-decalin glycol and the like can be mentioned.

The organic resin is dispersed or dissolved in water. As a method for dispersing or solubilizing in water, a known method is employed. For example, a method of producing the organic resin by an emulsion polymerization method using a surfactant, a method of mixing a surfactant with the organic resin and dispersing and dissolving it in an aqueous medium, and a method in which the resin has a carboxyl group or In the case of having an ionic functional group such as an amino group, a method of neutralizing the ionic functional group with a neutralizing agent and then dispersing/dissolving it in water, combined use of the above methods, and the like can be mentioned.

The aqueous resin (A) may be produced or may be a commercially available product.

In the present invention, from the viewpoint of anticorrosiveness of the coating film to be obtained, it is preferable that the water-based resin (A) contains, as a part of its components, a water-based epoxy resin obtained by rendering the epoxy resin water-based. When the water-based epoxy resin is contained, the non-volatile content of the water-based epoxy resin is preferably 50 parts by mass or more based on 100 parts by mass of the total non-volatile content of the water-based resin (A), and more preferably 60 parts by mass or more. preferable.

Further, when the water-based resin (A) contains a water-based epoxy resin, a water-based resin in which at least one resin selected from acrylic resins, urethane resins, and alkyd resins has been rendered water-based may be used in combination with the water-based epoxy resin. good. In this case, the nonvolatile content of the other combined resin is preferably 50 parts by mass or less based on 100 parts by mass of the total nonvolatile content of the aqueous resin (A), and the amount of the other combined resin is preferably 40 parts by mass or less. more preferred.

As used herein, the term "non-volatile matter" refers to the residue after excluding volatile ingredients such as water and organic solvents, and is a component that forms a coating film. As drying conditions for the sample when measuring the non-volatile content mass, for example, a method of heating 1 gram of the sample in a drier at 110° C. for 1 hour can be mentioned.

In the present invention, the water-based resin (A) is a water-based rust preventive paint composition based on 100 parts by mass of the non-volatile content of the water-based rust preventive paint composition, from the viewpoint of the storage stability in the paint state and the corrosion resistance of the paint film. It is preferably contained in an amount of 10 parts by mass or more, more preferably 20 parts by mass or more. On the other hand, the water-based resin (A) is preferably contained in the water-based rust preventive paint composition in an amount of 90 parts by weight or less, more preferably 80 parts by weight or less, based on 100 parts by weight of the nonvolatile matter of the water-based rust preventive paint composition. is more preferable.

<Emulsifier (B)>
The water-based antirust coating composition of the present invention contains an emulsifier (B) containing at least one of an amphiphilic substance that forms a closed vesicle and a polycondensation polymer having a hydroxyl group.

(Amphiphilic substances forming closed endoplasmic reticulum)
Amphiphilic substances that form closed vesicles (vesicles) are not particularly limited. Dialkylammonium derivatives, trialkylammonium derivatives, tetraalkylammonium derivatives, dialkenylammonium derivatives, trialkenylammonium derivatives, or halogen salt derivatives of tetraalkenylammonium derivatives can be mentioned.

general formula 1

In general formula 1, E, which is the average number of added moles of ethylene oxide, is an integer of 3 to 200, and L, M, N, X, Y and Z are integers of 0 to 100, respectively.

general formula 2

In general formula 2, R ₁ and R ₂ are each independently an alkyl group or alkenyl group having 8 to 22 carbon atoms, and R ₃ and R ₄ are each independently a hydrogen atom or a an alkyl group and X is F, Cl, Br or I;

As the amphiphilic substance, derivatives of polyoxyethylene hydrogenated castor oil are preferable, and "HCO-10", "HCO-20", "HCO-30" and "HCO-40" of the NIKKOL series manufactured by Nikko Chemicals Co., Ltd. , “HCO-50”, “HCO-60”, “HCO-100” and the like can also be used.

As the amphipathic substance, a phospholipid, a phospholipid derivative, or the like, in particular, a substance in which a hydrophobic group and a hydrophilic group are ester-bonded may be employed.

Phospholipids include, for example, compounds represented by the following general formula 3. Among the compounds represented by the general formula 3, DLPC with a carbon chain length of 12 (1,2-Dilauroyl-sn-glycero-3-phospho-rac-1-choline), DMPC with a carbon chain length of 14 (1,2- Dimyristoyl-sn-glycero-3-phospho-rac-1-choline) and DPPC with a carbon chain length of 16 (1,2-Dipalmitoyl-sn-glycero-3-phospho-rac-1-choline) are preferred.

general formula 3

In general formula 3, n is an integer of 11-17.

Furthermore, lecithin such as egg yolk lecithin or soybean lecithin may be employed as the phospholipid.

A fatty acid ester may be employed as the amphipathic substance. Examples of fatty acid esters include glycerin fatty acid esters (tetraglyceryl monostearate, decaglyceryl tristearate, etc.), sucrose fatty acid esters (sucrose stearate, etc.), sorbitan fatty acid esters, propylene glycol fatty acid esters, and the like. can be done. Among these, glycerin fatty acid esters and sucrose fatty acid esters are particularly preferred.

(Polycondensation polymer having hydroxyl group)
Examples of the polycondensation polymer having hydroxyl groups include compounds in which hydrophobic groups are introduced into some of the hydroxyl groups represented by the following general formula 4.

general formula 4

In general formula 4, each R is independently a hydrogen atom, a methyl group, —[R′O] _m H (wherein R′ is an alkyl group, m is an integer of 1 or more), or —R ''OC _p H _2p+1 (wherein, R'' is an alkyl group having a hydroxyl group in the side chain, p is an integer of 8 or more and 22 or less), and n is an integer of 100 or more. If n is too small, it is difficult to form stable particles, but in the present invention, a hydrophobic group is introduced to facilitate the formation of stable particles, so a value lower than the conventional value can be taken. A specific value of n may be set as appropriate, and may be, for example, 500 or more, 1000 or more, 1500 or more, or 2000 or more. R' and R'' are merely groups used when synthesizing the emulsifier (B), and may be various. For example, R' may be an alkyl group having about 1 to 3 carbon atoms, R'' may be a hydroxypropyl group.

Specific examples of the polycondensation polymer having a hydroxyl group include hydrophobized hydroxypropylmethylcellulose (e.g., stearoxyhydroxypropylmethylcellulose), and the "Sangelose" (registered trademark) series manufactured by Daido Kasei Kogyo Co., Ltd. (" 60L", "90L", "60M", "90M", etc.) can also be used.

From the viewpoint of paint storage stability, the mixing ratio of the emulsifier (B) is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the nonvolatile content of the aqueous resin (A). preferable. On the other hand, the content of the emulsifier (B) is preferably 15 parts by mass or less, more preferably 10 parts by mass or less based on 100 parts by mass of the non-volatile matter of the aqueous resin (A).

<Antirust pigment (C)>
As the rust preventive pigment (C), it is possible to use a rust preventive pigment known in the paint field, which may be an inorganic compound or an organic compound, and may be a single compound, a composite compound, or a composition in which a plurality of these compounds are used in combination. There are no restrictions on the form of things, etc. In particular, the effects of the present invention can be maximized when the antirust pigment is capable of eluting polyvalent metal ions into water.

Specific examples of the antirust pigment (C) include, for example, at least one metal selected from Mg, Ca, Ba, Zn and Al, a metal phosphate compound, a metal phosphite compound, a metal silicate compound, polyphosphoric acid At least one selected from metal compounds and metal oxides is included.

Examples of metal phosphate compounds include zinc phosphate, magnesium phosphate, magnesium/ammonium phosphate eutectoid, magnesium monohydrogen phosphate, magnesium dihydrogen phosphate, magnesium/calcium phosphate eutectoid, and magnesium phosphate. - cobalt eutectoid, magnesium/nickel eutectoid, calcium phosphate, calcium ammonium phosphate, calcium monohydrogen phosphate, calcium dihydrogen phosphate, calcium fluoride phosphate chloride, aluminum phosphate, aluminum hydrogen phosphate, etc.; Combinations of these are included.

Examples of metal phosphite compounds include magnesium phosphite, calcium phosphite, magnesium phosphite/calcium eutectoid, basic zinc phosphite, barium phosphite, manganese phosphite, calcium hypophosphite, and the like; and combinations thereof.

Examples of metal silicate compounds include calcium silicate, zinc silicate, aluminum silicate, aluminum orthosilicate, aluminum silicate hydrate, aluminosilicate, calcium aluminum silicate, sodium aluminum silicate, beryllium aluminum silicate, Sodium silicate, calcium orthosilicate, calcium metasilicate, sodium calcium silicate, zirconium silicate, magnesium orthosilicate, magnesium metasilicate, magnesium/calcium silicate, manganese silicate, barium silicate, magnesium ion-exchanged silica, calcium ion exchanged silica, etc.; and combinations thereof.

Metal polyphosphate compounds include, for example, aluminum dihydrogen tripolyphosphate, magnesium tripolyphosphate, aluminum tripolyphosphate, zinc dihydrogen tripolyphosphate, and the like; and combinations thereof.

Examples of metal oxides include zinc oxide, magnesium oxide, and aluminum oxide.

These may be used alone or in combination of two or more, or may be a composite of two or more.

The rust preventive pigment (C) described above is commercially available and can be used.

From the viewpoint of improving the storage stability of the paint and the anti-corrosion properties of the formed coating film, the mixing ratio of the antirust pigment (C) is 1 part by mass or more with respect to 100 parts by mass of the non-volatile content of the aqueous resin (A). is preferred, and 3 parts by mass or more is more preferred. On the other hand, the content of the rust preventive pigment (C) is preferably 70 parts by mass or less, more preferably 60 parts by mass or less based on 100 parts by mass of the non-volatile matter of the aqueous resin (A).

<Water-based rust preventive paint composition>
The water-based anticorrosive paint composition of the present invention contains the above-mentioned water-based resin (A), specific emulsifier (B) and anticorrosive pigment (C), and in addition to these components, optional ingredients as necessary. can contain. Other optional components include, for example, pigments such as coloring pigments and extender pigments known in the field of coatings; a curing agent having a functional group capable of reacting with the aqueous resin (A); a pigment dispersant, a curing agent, a conventional interface Additives such as activators, curing catalysts, surface modifiers, antifoaming agents, thickeners, film-forming aids, preservatives, antifungal agents, antifreeze agents, pH adjusters, aldehyde scavengers, lamellar viscosity minerals, etc. is mentioned.

The water-based antirust coating composition of the present invention preferably has a non-volatile content concentration of 10 mass % or more, more preferably 20 mass % or more, from the viewpoint of coating storage stability. On the other hand, the non-volatile content of the water-based anticorrosive coating composition is preferably 80% by mass or less, more preferably 70% by mass or less.

Although the reason why the water-based anticorrosive coating composition of the present invention is excellent in storage stability is not clear, the present inventors believe as follows.
FIG. 1 is an image diagram showing the coating state of the water-based rust preventive coating composition of the present invention. In FIG. 1, reference numeral 1 denotes an organic resin phase of an aqueous resin, and reference numeral 2 denotes a stabilized phase by closed endoplasmic reticulum or polycondensation polymer particles having hydroxyl groups. Here, the polycondensation polymer particles include both monoparticles of the polycondensation polymer and a series of the monoparticles, while aggregates (having a network structure) before being monoparticles ) are not included. In FIG. 1, reference numeral 3 denotes metal ions eluted from the antirust pigment into the aqueous phase.
The stabilized phase 2 made up of closed vesicles or polycondensed polymer particles that have been produced in advance or during the paint production stage is interposed at the interface between the aqueous phase and the organic resin phase 1, and constitutes an emulsified state via van der Waals forces. Therefore, a good emulsified state can be formed regardless of the composition and conditions of the organic resin phase 1 and the aqueous phase. It is believed that such an emulsified state not only stabilizes the organic resin phase 1 itself, but also effectively suppresses the reaction between the organic resin phase 1 and the metal ions 3 contained in the aqueous phase.

In order to form such an emulsified stable state in the present invention, a step of dispersing (forming into vesicles) the amphiphilic substance in the closed endoplasmic reticulum or a step of granulating the polycondensation polymer having hydroxyl groups is required. be. This requires various measures depending on the material used, but for example, a step of diluting the amphiphilic substance and/or the polycondensation polymer having a hydroxyl group with water, a step of heating to a temperature above the melting point or softening point, This can be accomplished by either adding a cleaving agent such as urea to break hydrogen bonds, adjusting the pH to 5 or less, or a combination thereof.

<Method for producing water-based anticorrosive paint composition>
In the present invention, the aqueous resin (A) is emulsified and stabilized by the emulsifier (B) specified in the present invention.

A first production method for producing a water-based anticorrosive coating composition includes a method of mixing a water-based resin (A) and an emulsifier (B). The first production method is suitable when an emulsifier containing an amphipathic substance that forms closed endoplasmic reticulum is used as the emulsifier (B). According to this first production method, the aqueous resin (A) can be emulsified and stabilized while the closed endoplasmic reticulum is being produced or produced.

In the first production method, it is preferable to add the emulsifier (B) to the composition containing the aqueous resin (A) while stirring. The composition containing the water-based resin (A) may contain additives such as antifoaming agents, leveling agents, dryers, etc., in addition to the water-based resin (A).

In addition, as a second manufacturing method for manufacturing the water-based anticorrosive coating composition of the present invention, the step of adding the emulsifier (B) to water under stirring to obtain a water-diluted product of the emulsifier (B) ( water dilution step) and a step of mixing the aqueous resin (A) with the water dilution (mixing step). According to this second production method, polycondensation polymer particles having closed endoplasmic reticulum or hydroxyl groups are produced in advance in the water dilution step, and mixed with the aqueous resin (A) to obtain the aqueous resin (A) in the paint. The emulsion stabilization of is improved, and a water-based anticorrosive coating composition can be produced stably.
In the second production method, when an emulsifier made from a polycondensation polymer having a hydroxyl group is used as the emulsifier (B), an emulsifier obtained by the method described in Japanese Patent No. 5652920 can be preferably used.

Also in the second production method, it is preferable to add the water-diluted emulsifier (B) to the composition containing the aqueous resin (A) under stirring. The composition containing the water-based resin (A) may contain additives such as antifoaming agents, leveling agents, dryers, etc., in addition to the water-based resin (A).

The stirring speed when adding the emulsifier (B) or the water-diluted product of the emulsifier (B) to the aqueous resin (A) is not particularly limited, and the speed is such that the outside of the vortex generated by stirring collides with the inner wall of the stirring vessel. should be stirred with Stirring at such a speed ensures uniform mixing of all components. Specifically, the stirring speed is preferably 200 to 4000 rpm, more preferably 500 to 3000 rpm.

Further, the reaction temperature for mixing the aqueous resin (A) and the emulsifier (B) or the water-diluted product of the emulsifier (B) is preferably 5 to 40°C, more preferably 10 to 30°C, from the viewpoint of the storage stability of the paint. is more preferred.

Further, the reaction time for mixing the aqueous resin (A) and the emulsifier (B) or the water-diluted product of the emulsifier (B) is preferably 0.1 to 24 hours, and 0.1 to 24 hours from the viewpoint of the storage stability of the paint. 2 to 8 hours is more preferred.

In addition, when the raw material constituting the emulsifier (B), that is, the amphiphilic substance forming the closed endoplasmic reticulum or the polycondensation polymer having a hydroxyl group is solid at room temperature, the raw material is heated to a temperature above the melting point or softening point. A step of heating to 20°C may be provided in advance.

The water-based antirust coating composition obtained as described above can be applied to the surface of metal substrates such as iron and aluminum, or to the surface of old coatings on metal substrates. As the old coating film, acrylic resin, acrylic urethane resin, polyurethane resin, fluorine resin, silicon acrylic resin, vinyl acetate resin, epoxy resin, alkyd resin, etc., provided on these substrates can be used. membranes. After applying the water-based rust preventive paint composition of the present invention as an undercoat to these surfaces to be coated, it is also possible to apply a known water-based topcoat.

The water-based anticorrosive coating composition of the present invention can be diluted with water or the like to a viscosity suitable for coating as required, and can be used for air spray coating, airless spray coating, electrostatic coating, brush coating, roller coating, ricing gun, and universal gun. It can be painted by other methods. The drying method may be normal temperature drying or heat drying. Normal temperature refers to the temperature at which temperature manipulation such as forced heating or cooling is not performed, although it varies depending on the atmospheric temperature of the environment where the coating is performed. Heat drying is forced heating manipulation using equipment such as a drying oven refers to the temperature at which

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited only to these examples. "Parts" and "%" in the following examples mean "mass parts" and "mass%" respectively.

<Production of water-based anticorrosive paint composition>
(Example 1)
40.0 parts of clean water, 5.0 parts of pigment dispersant, 40.0 parts of antirust pigment (C-1), 75.0 parts of titanium oxide, and 20.0 parts of talc are charged in order into a 225 ml container, and the paint is prepared. Stirring was continued with a shaker for 30 minutes until uniform to obtain a pigment paste.
Next, in another container of 500 ml, 175.0 parts of the aqueous resin (A-1) with a nonvolatile concentration of 40%, 60.0 parts of the aqueous resin (A-2) with a nonvolatile concentration of 50% and a nonvolatile concentration of 25.0 parts of a 12% emulsifier (B-4), 2.0 parts of a cobalt dryer as a curing catalyst, and 15.0 parts of clean water are charged, stirred and mixed well, and all of the pigment paste is added while stirring at 800 rpm. Then, the whole was stirred and mixed at 23° C. for 0.5 hour to produce a water-based rust preventive coating composition (No. 1).
The emulsifier (B-4) was prepared as follows. First, in a container of 300 ml, an amount of clean water to achieve the desired concentration was stirred at 800 rpm with a disper, and under stirring, stored in a constant temperature room of 50 ° C. for 12 hours to dissolve "NIKKOL HCO-60. (manufactured by Nikko Chemicals Co., Ltd., trade name, polyoxyethylene hydrogenated castor oil, E=60 in general formula 1).

(Example 2)
40.0 parts of clean water, 5.0 parts of pigment dispersant, 40.0 parts of antirust pigment (C-1), 75.0 parts of titanium oxide, and 20.0 parts of talc are charged in order into a 225 ml container, and the paint is prepared. Stirring was continued with a shaker for 30 minutes until uniform to obtain a pigment paste.
Next, 175.0 parts of the aqueous resin (A-1) having a non-volatile content of 40% and 60.0 parts of the aqueous resin (A-2) having a non-volatile content of 50% were charged in another 500 ml container, and While stirring at 1500 rpm, "NIKKOL HCO-60" (manufactured by Nikko Chemicals Co., Ltd., trade name, polyoxyethylene hydrogenated castor oil, general 3 parts of E=60 in Formula 1 were added for dilution.
Thereafter, the entire amount of the pigment paste, 2 parts of a cobalt dryer as a curing catalyst, and 15.0 parts of clean water were added thereto, and the whole was stirred and mixed at 23° C. for 0.5 hour to obtain a water-based anticorrosive coating composition (No. 2). ) was manufactured.

(Examples 3-22 and Comparative Examples 1-4)
Water-based antirust paint compositions (No. 3 to No. 26) were produced in the same manner as in Example 1 except that the materials used in Example 1 were changed as shown in Tables 1 to 3 below.

Then, each water-based antirust paint composition was subjected to the following tests for evaluation. The results are also shown in Tables 1-3.

(*) Storage stability 1 kg of each water-based antirust paint composition obtained in Examples and Comparative Examples was placed in a 1-liter inner-surface-coated can, sealed with nitrogen, and stored at 50°C for 1 week. Thereafter, the temperature was returned to room temperature, and the state and viscosity change in the container were evaluated according to the following criteria.
〔Evaluation criteria〕
◎: Remains in the initial state, no change 〇: Viscosity change, sediment is slightly, but it returns to the original state by stirring △: Viscosity change and sediment are observed, and it does not return to the original state even if it is stirred ×: gelled

(*) Corrosion resistance Each water-based rust preventive paint composition obtained in Examples and Comparative Examples was applied to an untreated mild steel plate with an applicator so that the dry film thickness was 40 μm, and after curing at 25 ° C. for 10 days. A test plate was prepared by cross-cutting the coating film surface with a cutter. Each obtained test plate was exposed to salt spray for 120 hours according to the JIS Z2371 salt spray test. After that, the degree of occurrence of rust and blisters on each test plate was evaluated according to the following criteria.
〔Evaluation criteria〕
◎: The rust width of the cut part is less than 1 mm, and no rust, blisters, etc. are observed in the general part. The rust width of the cut part is 1 to 3 mm, but rust and blisters occur slightly in the general part. ×: The rust width of the cut part exceeds 3 mm, and rust and blisters occur remarkably.

From the results in Tables 1 to 3, it was found that all of Examples 1 to 22 were able to achieve both storage stability and corrosion resistance, and had excellent effects.

REFERENCE SIGNS LIST 1 organic resin phase 2 stabilized phase 3 metal ion

Claims (10)

A water-based resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins, and modified resins thereof is made water-based;
an emulsifier (B) containing at least one of an amphiphilic substance forming a closed endoplasmic reticulum and a polycondensation polymer having a hydroxyl group;
Antirust pigment (C)
A water-based antirust paint composition containing 2. The water-based antirust coating composition according to claim 1, wherein said water-based resin (A) comprises a water-based epoxy resin as part of its components. 3. The water-based resin according to claim 2, wherein the water-based resin (A) further comprises, in addition to the water-based epoxy resin, a water-based resin in which at least one resin selected from acrylic resins, urethane resins, and alkyd resins is rendered water-based. Antirust paint composition. A water-based antirust coating composition according to any one of claims 1 to 3, wherein said amphiphilic substance is polyoxyethylene hydrogenated castor oil. 5. The water-based antirust coating composition according to any one of claims 1 to 4, wherein the water-based resin (A) is emulsified and stabilized by the emulsifier (B). A method for producing the water-based anticorrosive paint composition according to any one of claims 1 to 5,
An aqueous resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins and modified resins thereof is rendered water-based, and has an amphiphilic substance and a hydroxyl group forming a closed vesicle. A method for producing an aqueous antirust coating composition, comprising the step of mixing with an emulsifier (B) containing at least one polycondensation polymer. 7. The method for producing a water-based antirust paint composition according to claim 6, wherein the emulsifier (B) is added to the composition containing the water-based resin (A) under stirring. A method for producing the water-based anticorrosive paint composition according to any one of claims 1 to 5,
An emulsifier (B) containing at least one of an amphiphilic substance that forms a closed endoplasmic reticulum and a polycondensation polymer having a hydroxyl group is added to water under stirring to obtain a water dilution of the emulsifier (B). a step of obtaining
Water resistant, comprising a step of mixing a water-based resin (A) in which at least one resin selected from acrylic resins, epoxy resins, urethane resins, alkyd resins, and modified resins thereof has been made water-based, and the water-diluted product. A method for producing a rust coating composition. 9. The method for producing a water-based antirust paint composition according to claim 8, wherein the water-diluted product is added to the composition containing the water-based resin (A) under stirring. The method for producing a water-based antirust coating composition according to any one of claims 6 to 9, further comprising a step of heating the emulsifier (B) to a temperature above its melting point or softening point.

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