Water-based solvent-dispersible rust-preventive paint

Abstract

To provide a water-based solvent-dispersible rust-preventive paint that exhibits high rust prevention performance and has high dispersibility in water-based solvents, thereby having a low environmental impact. [Solution] A paint containing a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group, is used as an aqueous solvent-dispersible rust-preventive paint. Step 1: A step of graft polymerization of polysiloxane components and acrylic resin components to obtain copolymer resin (G); and Step 2: A step of mixing the copolymer resin (G) with an acrylic resin (Z) having hydrolyzable silyl groups; A water-soluble solvent-dispersible resin for rust-preventive paints is manufactured by a method including the following.

Description

[Technical Field]

[0001] This invention relates to a rust-preventive coating having aqueous solvent dispersibility, and a method for producing a resin for the rust-preventive coating. [Background technology]

[0002] Conventionally, various rust prevention treatments have been applied to materials that rust over time, such as steel plates. A typical rust prevention method involves first applying a primer composition containing an epoxy compound to the surface of the steel plate or other material to form a primer layer, and then applying a rust-preventive paint. The adhesion of rust-preventive paints to surfaces such as steel plates is not always sufficient, and in rust prevention treatments using rust-preventive paints, a primer layer is often applied to the surface of the steel plate.

[0003] As such rust-preventive coatings, coatings containing alkylarylalkoxypolysiloxane, alkyltrialkoxysilane condensates, and epoxy group-containing alkoxysilane condensates as resin components have been proposed for application on a primer layer (see Patent Document 1). Patent Document 1 discloses that rust-preventive pigments can be incorporated into the coating. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2001-259523 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, conventional rust-preventive paints are dispersible in organic solvents, requiring large amounts of organic solvents during application. This not only places a significant environmental burden on the environment but also necessitates measures to prevent health hazards to the workers, resulting in longer working times and higher application costs. Furthermore, from an environmental perspective, efforts have been made to develop rust-preventive paints that are dispersible in water-based solvents. However, such water-based paints have problems with durability and weather resistance and have not yet reached practical application.

[0006] The present invention aims to provide a water-solvent-dispersible rust-preventive coating that exhibits high rust-preventive performance and has high dispersibility in water-based solvents, thereby having a low environmental impact. [Means for solving the problem]

[0007] The inventors investigated the rust prevention performance of a silicone acrylic graft copolymer resin (G) containing a water-dispersible polysiloxane component and an acrylic resin component, but were unable to obtain sufficient rust prevention performance. Therefore, after further investigation, they discovered that rust prevention performance could be improved by using an acrylic resin (Z) having hydrolyzable silyl groups in combination with the silicone acrylic graft copolymer resin (G), and thus completed the present invention.

[0008] More specifically, the present invention provides the following (1) to (6). (1) A water-based solvent-dispersible rust-preventive paint comprising a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group. (2) The rust-preventive paint according to (1), comprising a silicone acrylic graft copolymer resin (G) and an acrylic resin having hydrolyzable silyl groups (Z), wherein the acrylic resin having hydrolyzable silyl groups (Z) is an acrylic emulsion resin (Z-1). (3) The rust-preventive paint according to (1) or (2), further comprising a hardening agent component as a separate solution. (4) A method for producing a water-soluble solvent-dispersible rust-preventive coating resin, Step 1: A step of graft polymerization of a polysiloxane component and an acrylic resin component to obtain a silicone acrylic graft copolymer resin (G); and Step 2: A step of mixing the silicone acrylic graft copolymer resin (G) with an acrylic resin (Z) having hydrolyzable silyl groups; A method for manufacturing a resin for rust-preventive coatings, including [the specified component]. (5) A method for producing a water-soluble solvent-dispersible resin for rust-preventive coatings, Step 1: A step of obtaining a silicone acrylic graft copolymer resin (G) by graft polymerization of a polysiloxane component and an acrylic resin component; Step 2-1: A step of adding 0.8 to 4 equivalents of water to 1 equivalent of the silicone acrylic graft copolymer resin (G) to disperse the silicone acrylic graft copolymer resin (G) in water; and Step 3: A step to synthesize a composite resin (GZ) by generating a hydrophobic acrylic resin (Z-2) by emulsion polymerization in the presence of the water-dispersed silicone acrylic graft copolymer resin (G). A method for manufacturing a resin for rust-preventive coatings, including [the specified component]. (6) A method for obtaining a laminate by applying a one-component aqueous solvent-dispersible rust-preventive coating to a substrate, comprising a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group, followed by heating to form a coating film. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an aqueous solvent-dispersible rust-preventive coating that exhibits high rust-preventive performance and has high dispersibility in aqueous solvents, thereby having a low environmental impact. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below.

[0011] Rust-preventive paint In the aqueous solvent-dispersible rust preventive coating of the present invention, a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component as a main component is used in combination with an acrylic resin (Z) further having a hydrolyzable silyl group. Hereinafter, the silicone acrylic graft copolymer resin (G) may be simply referred to as "copolymer resin (G)".

[0012] <Silicone acrylic graft copolymer resin (G) containing polysiloxane component and acrylic resin component> The silicone acrylic graft copolymer resin (G) usable in the present invention and the preparation method thereof are disclosed in, for example, Japanese Patent Application Laid-Open No. 2024-128283. Briefly, the silicone acrylic graft copolymer resin (G) refers to a resin obtained by graft-polymerizing a water-dispersible acrylic resin onto a polysiloxane component. In the present specification, the distinction between a water-dispersible acrylic resin and a hydrophobic acrylic resin can be made based on a TOC (total organic carbon) value obtained by a water solubility test in accordance with the polymer flow scheme specified in the Act on the Evaluation of Chemical Substances and Regulation of Their Manufacture, etc. (Chemical Substance Control Law). That is, in the present specification, the term "water-dispersible acrylic resin" means an acrylic resin having a TOC value in water of 1 mg / L or more in the above water solubility test, and the term "hydrophobic acrylic resin" means an acrylic resin having a TOC value in water of less than 1 mg / L in the same test.

[0013] For the synthesis of a water-dispersible acrylic resin, an acrylic monomer having no hydrolyzable silyl group, which constitutes a structural unit of the water-dispersible acrylic resin, is used. The synthesis of an aqueous acrylic resin in the presence of a polysiloxane component is typically performed according to a well-known radical polymerization method.

[0014] An example of an acrylic monomer not having a hydrolyzable silyl group that can be used here is given below. For example, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate; nitrile group-containing radical polymerizable monomers such as (meth)acrylonitrile; epoxy group-containing radical polymerizable monomers such as glycidyl (meth)acrylate; hydroxyl group-containing radical polymerizable monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate; monomers having two or more polymerizable unsaturated bonds such as ethylene glycol di(meth)acrylate, allyl (meth)acrylate; and fluorine-containing radical polymerizable monomers such as trifluoro (meth)acrylate, pentafluoro (meth)acrylate, perfluorocyclohexyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, β-(perfluorooctyl)ethyl (meth)acrylate.

[0015] The water-dispersible acrylic resin component may be composed only of structural units derived from a monomer that does not have a hydrolyzable silyl group, but in addition to structural units derived from a monomer, it may further include a structural unit derived from a monomer having a radical polymerizable group with a (meth)acryloyl group and a hydrolyzable silyl group. By forming the water-dispersible acrylic resin component using a monomer having a radical polymerizable group and a hydrolyzable silyl group, a hydrolyzable silyl group can be introduced into the water-dispersible acrylic resin component, which reduces water permeability by the coating layer and makes it possible to improve rust prevention.

[0016] The monomer having a radical polymerizable group having a (meth)acryloyl group and a hydrolyzable silyl group is not particularly limited, but examples include hydrolyzable silyl group-containing (meth)acrylates such as 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, (meth)acryloyloxyoctyltrimethoxysilane, and (meth)acryloyloxyoctyltriethoxysilane.

[0017] Polysiloxane components that can be used in the present invention and methods for preparing them are disclosed, for example, in Japanese Patent Publication No. 2024-128283 and Japanese Patent Publication No. 2024-44177. Here, the polysiloxane component refers to a polysiloxane obtained by hydrolysis and dehydration condensation reaction of a silane compound having a hydrolyzable silyl group. In the polysiloxane component, each constituent unit is linked by a siloxane bond (Si-O-Si bond). In short, the silicone acrylic graft copolymer resin (G) used in the present invention is a copolymer containing a polysiloxane component and an acrylic resin component, and the acrylic resin component has a polymer containing constituent units derived from monomers having radical polymerizable groups. The monomers include (i) monomers having a salt structure consisting of an acid and a base, being soluble in water and not forming micelles in water, and (ii) monomers capable of forming micelles in water.

[0018] In this specification, "salt structure" refers to the structure of a neutral salt obtained by neutralizing an acid and a base. Here, the acid used for neutralization may be a strong acid or a weak acid. Similarly, the base used for neutralization may be a strong base or a weak base. Furthermore, "soluble in water" means that when an aqueous solution prepared by adding 1 g of the monomer to 10 g of water at 25°C is thoroughly stirred, left to stand for one week under conditions of 25°C, and observed visually, no precipitate, dispersion, or separation of layers is observed in the aqueous solution, and it is transparent. "Micelle" refers to an aggregate formed by the association of amphiphilic molecules through hydrophobic interactions. Here, an amphiphilic molecule is intended to be a molecule having both a hydrophobic group and a hydrophilic group within it. Therefore, "forming micelles in water" refers to a structure having both a hydrophobic group and a hydrophilic group within it.

[0019] The silicone acrylic graft copolymer resin (G), having the above-described structure, can be stably dispersed and / or dissolved (water-based) in an aqueous medium, and when water-based, it can provide a silicone acrylic graft copolymer resin (G) that has an appropriate viscosity.

[0020] In this specification, "silicone acrylic graft copolymer resin (G)" means a resin containing a polysiloxane structure as its main component. The silicone acrylic graft copolymer resin (G) is not particularly limited as long as it satisfies the above definition, but examples include resins mainly composed of a polysiloxane structure obtained by dehydration condensation of a single compound represented by the following general formula (IV), or by co-condensation of multiple compounds represented by the following general formula (IV): R 1 a R 2 b -Si-(OR 3 ) 4-a-b ...(IV) (In the formula, R 1 R is a substituted alkyl group having 1 to 10 carbon atoms having a polymerizable unsaturated group, an alkenyl group, or an aryl group having a polymerizable unsaturated group and optionally having other substituents. 2each independently represents an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, or an unsubstituted or substituted aryl group, and R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, a is an integer of 1 to 3, b is an integer of 0 to 2, and a+b is an integer of 1 to 3.) Further, in one embodiment of the present invention, the silicone acrylic graft copolymer resin (G) may be a resin mainly composed of a polysiloxane structure obtained by co-condensing a single compound or a plurality of compounds represented by the above general formula (IV) with a single compound or a plurality of compounds represented by the following general formula (III): R 4 n -Si-(OR 5 ) 4-n ···(III) (wherein, R 4 each independently represents an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, or an unsubstituted or substituted aryl group, when there are a plurality of R 4 , they may be the same or different, R 5 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 0 to 3.)

[0021] <Acrylic resin (Z) having a hydrolyzable silyl group> In the present invention, the hydrolyzable silyl acrylic resin (Z) refers to a resin polymerized with acrylic monomers as the main component. Hereinafter, the hydrolyzable silyl acrylic resin (Z) may be simply referred to as "acrylic resin (Z)". The hydrolyzable silyl acrylic resin (Z) is an acrylic resin that contains hydrolyzable silyl groups in its side chains or molecular ends, which can generate silanol groups through hydrolysis. Examples of hydrolyzable silyl groups include alkoxysilyl groups, acetoxysilyl groups, and aminoalkoxysilyl groups. These groups readily hydrolyze in the presence of water or a catalyst, and the resulting silanol groups condense to form a crosslinked structure. As the hydrolyzable silyl acrylic resin (Z), an acrylic emulsion resin (Z-1) or a hydrophobic acrylic resin (Z-2) produced by any known method can be used. In this specification, "acrylic emulsion resin" means a resin having emulsion-like properties in which a polymer (resin component) mainly composed of structural units derived from acrylic monomers is dispersed in water, and "acrylic emulsion resin having hydrolyzable silyl groups" means an acrylic emulsion resin in which the polymer mainly composed of structural units derived from acrylic monomers, which are the resin components, is a copolymer that includes structural units derived from monomers having hydrolyzable silyl groups in addition to structural units derived from acrylic monomers.Examples of acrylic monomers used in hydrophobic acrylic resin (Z-2) include trimethoxysilylpropyl methacrylate (TSMA), trimethoxysilylpropyl acrylate, triethoxysilylpropyl methacrylate (TESMA), triethoxysilylpropyl acrylate, methyldimethoxysilylpropyl methacrylate (DSMA), methyldimethoxysilylpropyl acrylate, methyl methacrylate (MMA), butyl acrylate (BA), butyl methacrylate (BMA), cyclohexyl acrylate (CHA), cyclohexyl methacrylate (CHMA), ethyl acrylate (EA), propyl acrylate (PA), isobutyl acrylate (iBA), tert-butyl acrylate (tBA), 2-ethylhexyl acrylate (2-EHA), 2-ethylhexyl methacrylate (2-EHMA), n-hexyl acrylate, lauryl acrylate (LA), and stearyl acrylate (SA).

[0022] Embodiment 1 An embodiment in which a silicone acrylic graft copolymer resin (G) is mixed with an acrylic resin (Z) that has been polymerized separately is described. In this embodiment, it is preferable to prepare the curing agent described separately as a separate solution and use it as a two-component paint.

[0023] <Process 1> (Method for producing silicone acrylic graft copolymer resin (G)) Step 1 is a step of synthesizing a water-dispersible acrylic resin by radical polymerization in the presence of a polysiloxane component to obtain a copolymer resin (G). In other words, Step 1 is a step of obtaining a copolymer resin (G) containing polysiloxane units and water-dispersible acrylic resin units by radical polymerization of an acrylic monomer in the presence of a polysiloxane component. Polysiloxane is a polymer of a silane compound and is also called a polyorganosiloxane. It is preferable to use a polymerization catalyst in the polymerization of Step 1. Examples of polymerization catalysts include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(isobutyrate)dimethyl, tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, and diisopropyl peroxycarbonate. These may be used individually or in combination of two or more.

[0024] <Process 2> (Method for manufacturing the rust-preventive paint resin of Embodiment 1) (Method for producing acrylic resin (Z) having hydrolyzable silyl groups) The acrylic resin (Z) that can be used in this embodiment is an acrylic emulsion resin (Z-1) manufactured by any known method. The acrylic resin (Z-1) and its manufacturing method are disclosed, for example, in Japanese Patent Application Publication No. 2024-128283, WO2013-129488, etc. The rust-preventive paint resin of Embodiment 1 can be produced by mixing the copolymer resin (G) and the acrylic resin (Z) by a known method.

[0025] (Ratio of silicone acrylic graft copolymer resin (G) to acrylic resin having hydrolyzable silyl groups (Z)) In this embodiment of the present invention, as described above, a silicone acrylic graft copolymer resin (G) and an acrylic resin (Z) are synthesized separately and then mixed to prepare the product. The weight ratio of silicone acrylic graft copolymer resin (G) to acrylic resin (Z) (silicone acrylic graft copolymer resin (G) / acrylic resin (Z)) is 30 / 70 to 95 / 5, and may also be 35 / 65 to 90 / 10, 40 / 60 to 85 / 15, 45 / 55 to 80 / 20, or 50 / 50 to 75 / 25. By setting the weight ratio of silicone acrylic graft copolymer resin (G) to acrylic resin (Z) within the above range, it is possible to provide a water-based solvent-dispersible rust-preventive coating that offers excellent freeze-thaw resistance.

[0026] Embodiment 2 Embodiment 2 includes step 2-1, in which the copolymer resin (G) obtained in step 1 is dispersed in water, and step 3, in which a hydrophobic acrylic resin (Z-2) is copolymerized in the presence of the water-dispersed copolymer resin (G).

[0027] <Process 2-1> Step 2-1 is a step in which 0.8 to 4 equivalents of water are added to 1 equivalent of the copolymer resin (G) to disperse the copolymer resin (G) in water. The medium after step 1 may contain the organic solvent added in step 1. In step 2-1, this medium is converted into a medium mainly composed of water (diluted with water), thereby atomizing the copolymer resin (G). That is, an emulsion containing the copolymer resin (G) is obtained.

[0028] The amount of water added in step 2-1 is 0.8 to 4 equivalents per equivalent of copolymer resin (G), preferably 1 to 3 equivalents, and more preferably 1 to 2 equivalents, as described above. If the amount of water is 0.8 equivalents or more, uniformly dispersed particles are easily obtained. If the amount of water is 4 equivalents or less, the concentration of the emulsion containing copolymer resin (G) does not become too low, and the reaction in the next step 3 can be carried out suitably. In addition, the time required to remove water when manufacturing paint can be shortened.

[0029] Furthermore, before carrying out emulsion polymerization in the next step 3, solvents other than water may be removed by vacuum defloration. Preferably, 80% or more of these solvents other than water are removed, more preferably 90% or more by weight, and particularly preferably 95% or more by weight. Emulsion polymerization proceeds more easily when the content of solvents other than water is low. If there are too many solvents other than water, emulsion polymerization may not proceed, or the dispersion stability of the copolymer resin (G) dispersed in the resulting water may be disrupted, causing the particles to aggregate.

[0030] <Process 3> Step 3 is a step of synthesizing a hydrophobic acrylic resin (Z-2) by emulsion polymerization in the presence of the aqueous-dispersed copolymer resin (G). In other words, Step 3 is a step of obtaining a composite resin (GZ) containing polysiloxane units, aqueous-dispersible acrylic resin units, and hydrophobic acrylic resin units by emulsion polymerization of acrylic monomers (and optionally monomers other than acrylic monomers) in the presence of the aqueous-dispersed copolymer resin (G).

[0031] The acrylic monomers that form the structural units of the hydrophobic acrylic resin may include the acrylic monomers newly added in step 3 and the acrylic monomers that remain unreacted in steps 1 and 2-1.

[0032] In step 3, other monomers besides acrylic monomers may be copolymerized. Other copolymerizable monomers include, for example, aromatic hydrocarbon vinyl monomers such as styrene, α-methylstyrene, chlorostyrene, 4-hydroxystyrene, and vinyltoluene; vinyl esters or allyl compounds such as vinyl acetate, vinyl propionate, vinyl versatate, and diallyl phthalate; nitrile group-containing vinyl monomers such as (meth)acrylonitrile; vinyl methyl ether; propylene; and butadiene. Among these, styrene is preferred because it can provide a coating film with high gloss and excellent appearance.

[0033] In the polymerization of step 3, it is preferable to use a polymerization catalyst. As the polymerization catalyst, the initiators listed in step 1 can be used. Furthermore, when using oxidizing agents such as tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, and diisopropyl peroxycarbonate from among the initiators listed in step 1, a reducing agent may also be used in addition to these oxidizing agents. Examples of reducing agents include sodium sulfite, sodium thiosulfite, sodium hydroxymethanesulfinate, ascorbic acid, sodium ascorbate, Longalit, Bruggolite® FF-6, and thiourea dioxide.

[0034] (Physical properties of composite resin (GZ)) • Structural unit ratio The structural unit ratio in the composite resin (GZ), i.e., the weight ratio of copolymer resin (G) units to hydrophobic acrylic resin units, is preferably 50:50 to 85:15, and more preferably 50:50 to 80:20. The copolymer resin (G) units refer to the sum of the aforementioned siloxane units and water-dispersible acrylic resin units. When the structural unit ratio is within the above range, there are advantages such as improved dispersion stability when the composite resin (GZ) is aqueous-based and the provision of a coating film with excellent water resistance. The structural unit ratio can be calculated based on the amount of each monomer charged, minus the weight of the generated volatile components and the weight of the unreacted monomers.

[0035] ·Weight average molecular weight The weight-average molecular weight of the composite resin (GZ) is not particularly limited, but is preferably 30,000 to 300,000, and may be 40,000 to 300,000, 50,000 to 300,000, 70,000 to 270,000, or 100,000 to 250,000. In this specification, the weight-average molecular weight of the composite resin (GZ) can be calculated in polystyrene equivalent, for example, by measuring it using a high-speed GPC instrument HLC-8320GPC manufactured by Tosoh Corporation, with columns of TSKgel superH5000, TSKgel superH4000, TSKgel superH3000, or TSKgel guardcolumn SuperH-L, mobile phase of THF (tetrahydrofuran), measurement temperature of 40°C, and flow rate of 0.6 mL / min.

[0036] <Other ingredients> The aqueous solvent-dispersible rust-preventive coating of the present invention may also contain a curing catalyst in addition to the above-mentioned resin. By including a curing catalyst in the rust-preventive coating, it becomes possible to provide a coating film that is excellent not only in freeze-thaw resistance but also in stain resistance. In this specification, a curing catalyst refers to a substance that catalyzes a reaction in which hydrolyzable silyl groups condense to form a siloxane bond.

[0037] (curing catalyst) The curing catalyst that the rust-preventive paint may contain is preferably an organotin-based curing catalyst, more specifically, dialkyltin carboxylates (dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diethylhexanolate, dibutyltin dioctate, dibutyltin dimethyl malate, dibutyltin diethyl malate, dibutyltin dibutyl malate, dibutyltin diisooctyl malate, dibutyltin ditridecyl malate, dibutyltin dibenzyl malate, dibutyltin maleate, dioctyltin diacetate, dioctyltin distearate, dioctyltin dilaurate, dioctyltin diethyl malate, dioctyltin diisooctyl malate, etc.), dialkyltin oxides (dibutyltin oxide, dioctyltin oxide, mixtures of dibutyltin oxide and phthalate esters, etc.), and tetravalent tin compounds (dialkyltin oxide, dialkyltin diacetate, etc.). Examples include reaction products of tin with alkoxysilyl group-containing low molecular weight silicon compounds (tetraethoxysilane, methyltriethoxysilane, diphenyldimethoxysilane, phenyltrimethoxysilane, etc.), divalent tin compounds (tin octoate, tin naphthenate, tin stearate, etc.), monoalkyltin compounds (monobutyltin compounds (monobutyltin trisoctoate, monobutyltin triisopropoxide, etc.), monooctyltin compounds, etc.), reaction products or mixtures of amine compounds and organotin compounds (reaction products or mixtures of laurylamine and tin octoate, etc.), chelate compounds (dibutyltin bisacetylacetonate, dioctyltin bisacetylacetonate, dibutyltin bisethylacetonate, dioctyltin bisethylacetonate, etc.), and tin alkoxides (dibutyltin nitride, dibutyltin diethylate, dioctyltin nitride, dioctyltin diethylate, etc.).

[0038] (Silicate) If the rust-preventive coating contains a curing catalyst, the rust-preventive coating may further contain silicates to improve stain resistance. In this specification, silicate is a silicon compound having four hydrolyzable silyl groups in its molecule. Examples of silicates that can be contained in rust-preventive coatings include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-iso-butoxysilane, tetra-tert-butoxysilane, and their partial hydrolysates or condensates.

[0039] (Aqueous solvent) The aqueous solvent-dispersible rust-preventive coating of the present invention has the property of being stably dispersed in an aqueous solvent such as water. When water is used as the aqueous solvent, the water content in 100% by weight of the rust-preventive paint is, for example, 5-90% by weight, 10-80% by weight, 20-70% by weight, etc. Furthermore, water-soluble organic solvents such as alcohols including methanol and ethanol; ketones including acetone; and nitrogen-containing polar organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone may be used as desired, provided that they do not impede the dispersibility of the water-based resin in water.

[0040] (Other additives) In addition to the components described above, the rust-preventive paint may also contain additives commonly used in the art (particularly in the field of paints) to the extent that it achieves the effects of the present invention. Examples of such other additives include pigments, fillers, plasticizers, film-forming aids, wetting agents, dispersants, thickeners, defoaming agents, preservatives, antioxidants, anti-settling agents, leveling agents, UV absorbers, antistatic agents, antifreeze agents, antibacterial agents, antifungal and anti-algal agents, tackifiers, rust inhibitors, hydrophilic agents, etc. Only one type of other additive may be included, or two or more types may be included. Furthermore, the amount of these other additives can be appropriately determined by those skilled in the art depending on the intended use.

[0041] <Preparation of a one-component aqueous solvent-dispersible rust-preventive paint> The present invention can also be used as a one-component aqueous solvent-dispersible rust-preventive paint, comprising a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group. When used as a one-component aqueous solvent-dispersible rust-preventive paint, it is preferable to prepare a thermosetting resin composition by any known method for the main component resin composition containing a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group. When preparing a one-component, aqueous, solvent-dispersible rust-preventive paint, any component may be added to improve storage stability.

[0042] <Preparation of a two-component, aqueous, solvent-dispersible rust-preventive coating> In the present invention, it is preferable to prepare a curing agent solution separately from an aqueous dispersion of a main component (resin) containing a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group, and use it as a two-component aqueous solvent-dispersible rust-preventive paint.

[0043] (Main component: Preparation of an aqueous dispersion of resin) The present invention includes a mixing step in which a silicone acrylic graft copolymer resin (G) and an acrylic resin having hydrolyzable silyl groups (Z) are mixed in a weight ratio of 35 / 65 to 95 / 5. The amount of each component mixed in the mixing step (mixing ratio) becomes the content (content ratio) of each component in the resulting aqueous solvent-dispersible rust-preventive paint.

[0044] The weight ratio of silicone acrylic graft copolymer resin (G) / acrylic resin having hydrolyzable silyl groups (Z) is not particularly limited as long as it is in the range of 35 / 65 to 95 / 5, but may also be 45 / 55 to 90 / 10, 55 / 45 to 85 / 15, or 65 / 35 to 75 / 25.

[0045] In the mixing process, in addition to the silicone acrylic graft copolymer resin (G) / acrylic resin having hydrolyzable silyl groups (Z), other components may be further mixed.

[0046] (Preparation of hardening agent solution) When preparing a curing agent solution, the curing catalyst and silicate are dispersed in an aqueous solvent. To stabilize the dispersibility of the silicate in the aqueous solvent, additional components may be added.

[0047] <Components subject to rust prevention> The components subject to rust prevention refer to all components, regardless of their shape, that have a surface capable of rusting over time, including components used in civil engineering and construction, automotive parts, etc. The surface capable of rusting may be the entire surface of the component or only a part of it. Surface materials that can rust include various metals and alloys, typically iron or iron-containing steel plates. Examples of steel plates containing iron include carbon steel and iron-containing alloys. The carbon steel may be sub-low carbon steel, medium carbon steel, or high carbon steel. Various conventionally known alloys can be used as iron-containing alloys. Other elements that such alloys may contain include chromium, nickel, molybdenum, tungsten, cobalt, manganese, carbon, silicon, phosphorus, and sulfur.

[0048] Preferred materials include, for example, steel materials used in structures such as bridges and harbors that are particularly susceptible to sea breezes, steel materials used in ships used at sea, steel materials used in artificial reefs used on and under the sea, and pipes, valves, and tanks installed in factories.

[0049] The method of applying the rust-preventive coating is not particularly limited. Examples of application methods include spray coating, dipping, flow coating, curtain flow coating, spin coating, bar coating, and slit coating. Furthermore, the rust-preventive coating may be applied using rollers, brushes, or other similar tools.

[0050] ≪Method for obtaining a laminate≫ The method for obtaining the laminate of the present invention involves applying a one-component aqueous solvent-dispersible rust-preventive coating to a substrate, which contains a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having hydrolyzable silyl groups, and then forming a coating film by heating. The laminate according to this embodiment can be obtained by applying a one-component aqueous solvent-dispersible rust-preventive coating to one side of a substrate made of civil engineering and construction materials and curing it. The application and curing conditions are not particularly limited, but when curing, it may be left at room temperature for 3 to 14 days, or the evaporation of the solvent and the curing reaction may be accelerated by heating using a heat source. When heating using a heat source, it is preferably heated at 60°C to 160°C, more preferably at 80 to 120°C for 2 to 60 minutes. [Examples]

[0051] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. [Polymer synthesis] 〔material〕 The following materials were used in the synthesis of the polymer. (Silane compounds) Methyltrimethoxysilane (abbreviated as "M-TMS"): "Z-6366" manufactured by Dow Toray Industries, Inc. Phenyltrimethoxysilane (abbreviated as "Ph-TMS"): "Z-6124" manufactured by Dow Toray Industries, Inc. Vinyltrimethoxysilane (abbreviated as "V-TMS"): "A-171" manufactured by Momentive Performance Materials Japan LLC. (Vinyl monomers) Methyl methacrylate (abbreviated as "MMA"): Manufactured by Mitsubishi Gas Chemical Company, Inc. Butyl acrylate (abbreviated as "BA"): Manufactured by Nippon Shokubai Co., Ltd. Butyl methacrylate (abbreviated as "BMA"): Manufactured by Fujifilm Wako Pure Chemical Corporation Styrene: Manufactured by Fujifilm Wako Pure Chemical Corporation γ-Methacryloxypropylmethyldimethoxysilane (abbreviated as "DSMA"): "Z-6033" manufactured by Dow Toray Corporation. γ-Methacryloyloxypropyltrimethoxysilane (abbreviated as "TESMA"): "Y-9936" manufactured by Momentive Performance Materials Japan LLC. γ-Methacryloxypropyltrimethoxysilane (abbreviated as "TSMA"): "A-174" manufactured by Momentive Performance Materials Japan LLC. Glycidyl methacrylate (abbreviated as "GMA"): "Bremmer G" manufactured by NOF Corporation. 2-Hydroxyethyl methacrylate (abbreviated as "HEMA"): Manufactured by Mitsubishi Chemical Corporation Sodium acrylamide-tert-butylsulfonate: "ATBS-Na" manufactured by Toagosei Co., Ltd. Methoxypolyethylene glycol methacrylate (abbreviated as "M-90G"): "NK Ester M-90G" manufactured by Shin Nakamura Chemical Industry Co., Ltd. Polyethylene glycol-monomethacrylate (abbreviated as "PE-200"): "Bremmer PE-200" manufactured by NOF Corporation. Ether sulfate type ammonium salt (abbreviated as "SR-10"): "Adekaria Soap SR-10" manufactured by ADEKA Corporation, commercially classified as "reactive anionic emulsifier", a compound represented by the following formula (A): [ka] Ether sulfate type ammonium salt (active ingredient 25%) (abbreviated as "SR-1025"): "Adekaria Soap SR-1025" manufactured by ADEKA Corporation Ethylene oxide addition type reactive nonionic surfactant (abbreviated as "ER-20"): "ADEKA Soap ER-20" manufactured by ADEKA Corporation. (others) pure water Deionized water Sodium bicarbonate: Manufactured by Fujifilm Wako Pure Chemical Corporation Dibutyl phosphate: "DBP" manufactured by Johoku Chemical Industry Co., Ltd. 2-Propanol: Manufactured by Nacalai Tesque Co., Ltd. Methanol: Manufactured by Nacalai Tesque Co., Ltd. 2,2'-Azobis(2,4-dimethylvaleronitrile): "V-65" manufactured by Fujifilm Wako Pure Chemical Corporation Mixture of 2-hydroxy-2-sulfinate disodium acetate (abbreviated as "FF-6"): "Bruggolite FF-6" manufactured by Bruggemann Chemical. tert-butyl hydroperoxide: "Kayabutyl H-70" manufactured by Kayaku Akzo Co., Ltd. Ferrous sulfate heptahydrate: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Ethylenediaminetetraacetate disodium: Manufactured by Fujifilm Wako Pure Chemical Corporation n-Dodecyl mercaptan (abbreviated as "n-DM"): Manufactured by Fujifilm Wako Pure Chemical Corporation. 2,2'-Azobis(2-methylbutyronitrile) (abbreviated as "V-59"): Manufactured by Fujifilm Wako Pure Chemical Corporation

[0052] (Synthesis Example 1) In a reaction vessel equipped with a stirrer, reflux condenser, nitrogen gas inlet tube, and dropping funnel, 312 parts by weight of deionized water, 1.3 parts by weight of SR-1025, and 2.0 parts by weight of 5% sodium bicarbonate aqueous solution were charged, and the temperature was raised to 50°C while introducing nitrogen gas. After raising the temperature, 4.0 parts by weight of 7% tert-butyl hydroperoxide aqueous solution, 2.8 parts by weight of 10% FF-6 aqueous solution, and 5.6 parts of ferrous sulfate heptahydrate (0.10%) / ethylenediaminetetraacetate disodium (0.40%) mixed aqueous solution were added, and 148 parts by weight of BA, 42 parts by weight of styrene, 10 parts by weight of DSMA, 7.7 parts by weight of SR-1025, 6.0 parts by weight of ER-20, and 72 parts by weight of deionized water were added to form an emulsified monomer emulsion, which was then added at a constant rate over 120 minutes. During this time, 2.0 parts by weight of a 7% tert-butyl hydroperoxide aqueous solution and 3.2 parts by weight of a 2.5% FF-6 aqueous solution were added in two separate additions. Polymerization was carried out 1 hour after the addition of the monomer emulsion was completed. 43.8 parts by weight of MMA, 480 parts by weight of BMA, 16 parts by weight of styrene, 10 parts by weight of TESMA, 12.8 parts by weight of GMA, 12.8 parts by weight of HEMA, 7.2 parts by weight of M-90G, 14.4 parts by weight of PE-200, 3.0 parts by weight of n-DM, 43.2 parts by weight of SR-1025, 9.0 parts by weight of ER-20, and 192 parts by weight of deionized water were added to the monomer emulsion, which was then added at a constant rate over 300 minutes. During this time, 10.0 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 15.2 parts by weight of a 2.5% FF-6 aqueous solution were added in seven separate additions. Polymerization was carried out 1.5 hours after the addition of the monomer emulsion was completed. 28 parts by weight of a 5% sodium bicarbonate aqueous solution was added to the resulting synthetic resin emulsion, and then the solid content was adjusted to 50% with deionized water to obtain an aqueous acrylic silicone resin emulsion (Z-1).

[0053] (Synthesis Example 2) (Synthesis of polysiloxane units) In a reactor equipped with a stirrer, thermometer, and reflux condenser, 2.5 parts by weight of V-TMS, 44.7 parts by weight of M-TMS, 35.4 parts by weight of Ph-TMS, 24.8 parts by weight of pure water, and 0.0024 parts by weight of DBP were charged and the mixture was reacted at a reaction temperature of 68°C for 3 hours with stirring to obtain polyorganosiloxane, which is a polysiloxane unit. (Polymerization of acrylic polymer units) To the reactor containing the aforementioned polysiloxane units, a mixture of 8.1 parts by weight of MMA, 23.5 parts by weight of BA, 10.0 parts by weight of HEMA, 2.4 parts by weight of ATBS-Na, 6.0 parts by weight of SR-10, and 0.25 parts by weight of the radical initiator V-65 was added dropwise from a dropping funnel at a constant rate over 3 hours. Next, a mixture of 0.14 parts by weight of the radical polymerization initiator V-65 and 10 parts by weight of methanol was added dropwise at a constant rate over 0.5 hours. After the addition, the mixture was stirred at 75°C for 2 hours, and then diluted with water. Subsequently, defoliation was performed using a rotary evaporator to adjust the non-volatile components to 50%, and then the mixture was cooled to room temperature to obtain an aqueous silicone acrylic graft copolymer emulsion (G-1) containing silicone acrylic graft copolymer resin and water. (Preparation of silicone acrylic resin) A mixture of 60 parts by weight of the aforementioned aqueous silicone acrylic graft copolymer resin emulsion (G-1) and 40 parts by weight of the aforementioned aqueous acrylic silicone resin emulsion (Z-1) was stirred for 0.5 hours to obtain the composite resin (GZ-1).

[0054] (Synthesis Example 3) (Synthesis of polysiloxane units) In a reactor equipped with a stirrer, thermometer, and reflux condenser, 39.9 parts by weight of monomer M-TMS of the types listed in Table 1, 31.6 parts by weight of Ph-TMS, 2.5 parts by weight of V-TMS, 24.8 parts by weight of pure water, and 0.024 parts by weight of condensation catalyst DBP were charged. The reaction was carried out at a reaction temperature of 68°C for 3 hours with stirring to obtain polyorganosiloxane, which is a polysiloxane unit.

[0055] (Polymerization of acrylic polymer units) To the reactor containing the aforementioned polysiloxane units, a mixed solution of 7.7 parts by weight of MMA, 22.3 parts by weight of BA, 9.5 parts by weight of HEMA, 2.3 parts by weight of ATBS-Na, 5.7 parts by weight of SR-10, and 0.95 parts by weight of V-65, a radical polymerization initiator, was added dropwise at a constant rate from a dropping funnel over 3 hours. Next, a mixed solution of 0.14 parts by weight of V-65, a radical polymerization initiator, and 8.3 parts by weight of methanol was added dropwise at a constant rate over 0.5 hours. After the addition, the mixture was stirred at 75°C for 2 hours, and then diluted with water. Subsequently, defoliation was performed using a rotary evaporator to adjust the non-volatile components to 50%, and the mixture was further cooled to room temperature to obtain an emulsion of silicone acrylic graft copolymer resin (G-2).

[0056] In a reactor equipped with a stirrer, thermometer, and reflux condenser, 155.5 parts by weight of the aqueous silicone acrylic graft copolymer resin emulsion (G-2) was charged. A monomer tank was prepared containing a mixture of 0.3 parts by weight of TSMA, 17.5 parts by weight of MMA, and 42.6 parts by weight of BA, which was then gradually added dropwise over 3 hours using a pump. Immediately after starting the pump, 8.45 parts by weight of FF-6 prepared as a 2% aqueous solution and 0.28 parts by weight of tert-butyl hydroperoxide prepared as a 7% aqueous solution were added. After another 30 minutes, another 0.28 parts by weight of tert-butyl hydroperoxide prepared as a 7% aqueous solution was added. After another 30 minutes, another 0.28 parts by weight of tert-butyl hydroperoxide prepared as a 7% aqueous solution was added. After another 30 minutes, another 0.28 parts by weight of tert-butyl hydroperoxide prepared as a 7% aqueous solution was added. After another 30 minutes, 1.98 parts by weight of FF-6 prepared as a 2% aqueous solution was added. The mixture was then stirred for another 30 minutes to produce a hydrophobic acrylic resin by emulsion polymerization in the presence of a silicone acrylic graft copolymer resin. The solids content was then adjusted to 50% with deionized water to obtain a composite resin (GZ-2).

[0057] (Synthesis Example 4) (Synthesis of polysiloxane units) In a reactor equipped with a stirrer, thermometer, and reflux condenser, 39.9 parts by weight of monomer M-TMS of the types listed in Table 1, 33.8 parts by weight of Ph-TMS, 4.8 parts by weight of V-TMS, 24.1 parts by weight of pure water, and 0.023 parts by weight of condensation catalyst DBP were added and the mixture was reacted at a reaction temperature of 68°C for 3 hours with stirring to obtain polyorganosiloxane, which is a polysiloxane unit. (Polymerization of acrylic polymer units) To the reactor containing the aforementioned polysiloxane units, a mixed solution of 8.1 parts by weight of MMA, 23.5 parts by weight of BA, 2.3 parts by weight of ATBS-Na, 5.7 parts by weight of SR-10, and 0.95 parts by weight of V-65, a radical polymerization initiator, was added dropwise at a constant rate from a dropping funnel over 3 hours. Next, a mixed solution of 0.14 parts by weight of V-65, a radical polymerization initiator, and 8.3 parts by weight of methanol was added dropwise at a constant rate over 0.5 hours. After the addition, the mixture was stirred at 75°C for 2 hours, and then diluted with water. Subsequently, defoliation was performed using a rotary evaporator to adjust the non-volatile components to 50%, and the mixture was further cooled to room temperature to obtain an emulsion of silicone acrylic graft copolymer resin (G-3).

[0058] (Preparation of water-based white paint base) 〔material〕 The polymer prepared above and the following materials were used to create the main component of the water-based white paint. (Formulating agent for water-based white paint main component) pure water Antifreeze: Propylene glycol manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Humectant: "Dispex Ultra FA 4437" manufactured by BASF Japan Ltd. Dispersant: Cray Valley's "SMA1440H Solution" Dispersant: "Disperbyk-2090" manufactured by BIC Chemie Japan Co., Ltd. Pigment (titanium dioxide): "Typake PFC105" manufactured by Ishihara Sangyo Co., Ltd. Preservative: "Slout 99N" manufactured by Nippon Enviro-Chemicals Co., Ltd. Antifoaming agent: "Agitan295" by MUNZING CHEMIE Film-forming aid: "CS-12" (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate) manufactured by JNC Corporation. Thickener: "SN Thickener 612NC" manufactured by Sunopco Co., Ltd. Antifungal and anti-algal agent: "Monicide AZ" manufactured by Nippon Enviro-Chemicals Co., Ltd.

[0059] (Example of preparation of water-based white paint base) Using the silicone acrylic resin emulsions (GZ-1, 2, G-3, Z-1) from Synthesis Examples 1-4, a water-based white paint base was prepared by blending each component shown in Table 1 in the weight parts indicated. Specifically, 16.55 parts by weight of water, 6.9 parts by weight of propylene glycol, 1.72 parts by weight of Dispex Ultra FA 4437, 2.41 parts by weight of SMA1440H Solution, 1.72 parts by weight of Disperbyk-2090, 69.66 parts by weight of Typeque PFC105, 0.69 parts by weight of Slaut 99N, 0.34 parts by weight of Agitan 295, and 50 parts by weight of glass beads with a particle size of approximately 2 mm were added to a metal container. The mixture was kneaded at 1000 rpm for 1 hour using an Imex sand grinder, and the glass beads were removed by filtration through a wire mesh to obtain mill base (M-1). The obtained mill base was mixed with the components listed in Table 1, stirred at 2000 rpm for 15 minutes using an IKA homogenizer, and then mixed with water-based white paint main components (WT-1~4).

[0060] [Table 1]

[0061] (Preparation of the hardening agent) 〔material〕 The following materials were used to prepare the hardening agent. (solvent) Polyethylene glycol fatty acid ester type nonionic surfactant: "Ionet DO-600" manufactured by Sanyo Chemical Industries, Ltd. Ethyl polysilicate: "Silicate 40" manufactured by Tama Chemical Industry Co., Ltd. Dipropylene glycol dimethyl ether: "ProGlide DMM" manufactured by Ando Parachemy Co., Ltd. Dibutyltin bis(acetylacetonate): "Neostan U-220H" manufactured by Nitto Kasei Co., Ltd. n-Dodecyl mercaptan (abbreviated as "n-DM"): Manufactured by Fujifilm Wako Pure Chemical Corporation. Hindered amine light stabilizer: "TINUVIN 5100" manufactured by BASF Japan Ltd. Hydrophilic modified aliphatic polyisocyanate: "Baihijur 401-70" manufactured by Covestro Co., Ltd.

[0062] (Example of hardening agent preparation 1) To a glass container, 10.7 parts by weight of Ionet DO-600, 53.4 parts by weight of Silicate 40, 17.5 parts by weight of Proglide DMM, 3.5 parts by weight of Neostan U-200H, 1.4 parts by weight of n-DM, 3.2 parts by weight of TINUVIN 5100, and 10.2 parts by weight of Bahijur 401-70 were added and stirred at room temperature for 30 minutes to obtain curing agent (B-1).

[0063] (Creating a coating layer) 〔material〕 The above white paint base and the following materials were used to create the coating layer. (base material) Cold-rolled steel sheet test specimen manufactured by TP Giken Co., Ltd. (Examples of coating layer fabrication) (Examples 1-3, Comparative Examples 1 and 2) For the white paint main components WT-1 to WT-4 prepared in Table 1, apply 0.1 kg / m² to the cold-rolled steel sheet test specimens, which are the substrates, using an air spray. 2 The paint was applied evenly to achieve the desired result, and the coating layer was obtained by curing under the conditions (temperature (°C), time) described in Table 2. In Examples 1 and 2 and Comparative Example 2, a two-component paint was used, and the coating layer was formed by mixing the hardener (B-1) with the white paint base before painting. On the other hand, in Example 3 and Comparative Example 1, a one-component paint was used, and the coating layer was formed by painting only the white paint base without using the hardener (B-1).

[0064] [Measurement and evaluation methods] Measurements and evaluations in the examples and comparative examples were performed using the following methods. (Salt spray test) A neutral salt spray test according to JIS K5600-7-1 was conducted for 480 hours. After the test, the area of ​​the normal portion (without blistering or cracking) was calculated from the observed portion of the sample, excluding the cross-cut portion and the 1 cm edge of the test specimen. The calculation formula is as follows. Percentage of normal area (%) = Area of ​​normal area ÷ Total area of ​​observed area

[0065] [Table 2]

[0066] In Comparative Examples 1 and 2, blistering and cracking caused by rust occurred throughout the test specimen, but this was improved in Examples 1 to 3. The improvement was particularly significant in Example 1, and the two-component type including the curing agent exhibited a high rust-preventive effect. Furthermore, a higher rust-preventive effect was observed when using a mixed resin (GZ-1) of silicone acrylic graft copolymer resin and acrylic silicone emulsion, compared to a copolymer resin (GZ-2) obtained by emulsion polymerization of hydrophobic acrylic monomer in the presence of silicone acrylic graft copolymer resin.

Claims

1. A water-based solvent-dispersible rust-preventive paint comprising a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group.

2. The rust-preventive paint according to claim 1, comprising the silicone acrylic graft copolymer resin (G) and the hydrolyzable silyl group-containing acrylic resin (Z), wherein the hydrolyzable silyl group-containing acrylic resin (Z) is an acrylic emulsion resin (Z-1).

3. Furthermore, the rust-preventive paint according to claim 1 or 2, further comprising a hardening agent component as a separate solution.

4. A method for producing a water-soluble solvent-dispersible rust-preventive coating resin, Step 1: A step of graft polymerization of a polysiloxane component and an acrylic resin component to obtain a silicone acrylic graft copolymer resin (G); and Step 2: A step of mixing the silicone acrylic graft copolymer resin (G) with an acrylic resin (Z) having hydrolyzable silyl groups; A method for manufacturing a resin for rust-preventive coatings, including [the specified component].

5. A method for producing a water-soluble solvent-dispersible rust-preventive coating resin, Step 1: A step of graft polymerization of a polysiloxane component and an acrylic resin component to obtain a silicone acrylic graft copolymer resin (G); Step 2-1: A step of adding 0.8 to 4 equivalents of water to 1 equivalent of the silicone acrylic graft copolymer resin (G) to disperse the silicone acrylic graft copolymer resin (G) in water; and Step 3: A step to synthesize a composite resin (GZ) by generating a hydrophobic acrylic resin (Z-2) by emulsion polymerization in the presence of the water-dispersed silicone acrylic graft copolymer resin (G). A method for manufacturing a resin for rust-preventive coatings, including [the specified component].

6. A method for obtaining a laminate by applying a one-component aqueous solvent-dispersible rust-preventive coating to a substrate, comprising a silicone acrylic graft copolymer resin (G) containing a polysiloxane component and an acrylic resin component, and an acrylic resin (Z) having a hydrolyzable silyl group, followed by heating to form a coating film.

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