WO2020138186A1

WO2020138186A1 - Coating composition kit and use thereof

Info

Publication number: WO2020138186A1
Application number: PCT/JP2019/050865
Authority: WO
Inventors: 浩章村田; 耕一郎福島; 展央三村
Original assignee: 中国塗料株式会社
Priority date: 2018-12-27
Filing date: 2019-12-25
Publication date: 2020-07-02
Also published as: JP7209015B2; CN113227267B; CN113227267A; JPWO2020138186A1

Abstract

A coating composition kit that comprises: a first agent comprising a siloxane binder (A), kaolin (B) and a pigment (C) having a Mohs hardness of 5 or higher; and a second agent comprising a zinc powder (X).

Description

Paint composition kit and use thereof

The present invention relates to a coating composition kit and its use.

The inorganic zinc-rich paint is a coating composition containing an inorganic resin such as a hydrolyzed condensate of silicate as a binder component and containing a large amount of zinc powder. For example, a one-liquid one-powder type coating composition kit is known. There is. Inorganic zinc rich paint can prevent corrosion of steel materials by sacrificial anticorrosion effect of zinc and formation of oxide film with high barrier property in corrosive environment, and it is widely used for anticorrosion of large steel structures such as ships and bridges. It is used.

It is known that one example of the inorganic zinc-rich paint contains a hydrolyzed condensate of silicate as a binder component, and curing proceeds with water.
Incidentally, the inorganic zinc-rich paint is sometimes applied to the bolted joint portion of the steel material in order to enhance the sliding frictional force of the joint surface. In such a case, the slip coefficient is generally 0.4 to 0.5, but Patent Document 1 discloses a zinc-rich coating composition having a slip coefficient of more than 0.5.

JP-A-2003-306638

As a result of studies by the present inventors, in order to increase the slip coefficient of a coating film of an inorganic zinc-rich paint, it was attempted to produce a coating composition kit having a mixed powder in which zinc powder and an extender pigment or a special pigment were mixed. In this case, it has been found that classification must be performed at the time of manufacturing the mixed powder, and mixing defects of the powders easily occur depending on the pigment, classification is difficult and time-consuming, and cost is high, which is not economical.

On the other hand, in a coating composition kit having a first agent containing a binder component and a second agent containing zinc powder, when the pigment is dispersed in the first agent, there is a problem that storage stability deteriorates. I understood it. For example, if the high hardness pigment described in Patent Document 1 is added to the first agent in order to increase the slip coefficient of the coating film, the storage stability deteriorates. As the inorganic zinc-rich paint, it may be necessary to store it for a long period of 12 months, which causes a problem that the storage stability of the first agent is deteriorated.

An object of the present invention is to provide a coating composition kit which is excellent in long-term storage stability and can form a coating film having an excellent slip coefficient at a bolted joint of a steel material, for example.

The present inventors have diligently studied to solve the above problems. As a result, they have found that the above-mentioned problems can be solved by a coating composition kit having the following constitution, and completed the present invention.
The present invention relates to the following [1] to [10], for example.

[1] A coating composition having a first agent containing a siloxane-based binder (A), kaolin (B) and a pigment (C) having a Mohs hardness of 5 or more, and a second agent containing zinc powder (X). Thing kit.

[2] The coating composition kit according to the above [1], wherein the siloxane-based binder (A) has a weight average molecular weight (Mw) of 500 to 10,000.
[3] The coating material according to [1] or [2], wherein the siloxane-based binder (A) is a condensate of at least one compound (A1) selected from tetraalkoxysilane and alkyltrialkoxysilane. Composition kit.

[4] The coating composition kit according to any one of [1] to [3], wherein the pigment (C) contains at least one selected from yellow iron oxide, potassium feldspar, and silica.
[5] A coating composition obtained by mixing at least the first agent and the second agent in the coating composition kit according to any one of [1] to [4].

[6] A method for producing a coating composition, which comprises a step of mixing at least the first agent and the second agent in the coating composition kit according to any one of [1] to [4].
[7] A coating film formed from the coating composition as described in [5] above.

[8] A coated substrate having a substrate and the coating film according to [7] above.
[9] The coated substrate according to [8], wherein the substrate is a steel material constituting a steel structure.

[10] A steel material with a coating, comprising a steel material and the coating film according to [7] formed on a joint surface of a bolted joint portion of the steel material.

According to the present invention, it is possible to provide a coating composition kit capable of forming a coating film which is excellent in long-term storage stability and is also excellent in, for example, a slip coefficient at a bolted joint of a steel material.

Hereinafter, modes for carrying out the present invention will be described in detail.
In the present specification, the coating composition kit according to one embodiment of the present invention is also referred to as “coating composition kit of the present embodiment”, and at least the first agent and the second agent in the coating composition kit of the present embodiment are included. The coating composition obtained by mixing is also referred to as the "coating composition of the present embodiment", and the coating film formed from the coating composition of the present embodiment is also referred to as the "coating film of the present embodiment".

In the present specification, the "slip coefficient" is measured based on "Appendix 7 Slip coefficient evaluation test method" of "steel structure joint design guideline" (3rd edition, Japan Institute of Architecture, 2012). The slip coefficient.

[Paint Composition Kit and Paint Composition]
The coating composition kit of this embodiment has a first agent and a second agent.
The first agent contains a siloxane-based binder (A), kaolin (B), and a pigment (C) having a Mohs hardness of 5 or more.

The second agent contains zinc powder (X).
The coating composition kit of the present embodiment is a package type kit, and in one embodiment, a one-liquid/one-powder type kit comprising a liquid first agent and a powdery second agent.

≪First agent≫
In the present embodiment, since the first agent containing the siloxane-based binder (A) contains kaolin (B) and the pigment (C) having a Mohs hardness of 5 or more, the zinc powder ( There is no need for a step of mixing X) with kaolin (B) and a pigment (C) having a Mohs hardness of 5 or more for classification.
The first agent is preferably liquid.

<Siloxane type binder (A)>
The first agent contains a siloxane-based binder (A). The siloxane-based binder (A) is usually a silicate condensate, specifically a compound obtained by hydrolyzing and condensing the silicate.

Examples of the siloxane-based binder (A) include a condensate of at least one compound (A1) selected from tetraalkoxysilane and alkyltrialkoxysilane, and specifically, the compound (A1) and/or Alternatively, a partially hydrolyzed condensate of a low condensate thereof may be mentioned.

Examples of the tetraalkoxysilane include tetramethyl orthosilicate, tetraethyl orthosilicate, tetra-n-propyl orthosilicate, tetra-i-propyl orthosilicate, tetra-n-butyl orthosilicate and tetra-sec-butyl orthosilicate. Examples of the alkyltrialkoxysilane include methyltrialkoxysilanes such as methyltrimethoxysilane and methyltriethoxysilane.

Examples of the low condensate of the compound (A1) include low condensates of the tetraalkoxysilanes such as methyl polysilicate and ethyl polysilicate. The low condensate refers to a condensate having a condensation degree of 2 to 20 (silicon atom number of 2 to 20).

As the low condensate, a low condensate of tetraethyl orthosilicate is preferable, and as the low condensate of tetraethyl orthosilicate, for example, "ethyl silicate 45", "ethyl silicate 40" and "ethyl silicate 48" (above, corcoat) Manufactured by Asahi Kasei Wacker Silicone Co., Ltd., and “Silicate 45” and “Silicate 40” (manufactured by Tama Chemical Industry Co., Ltd.) and “TES40WN” (manufactured by Asahi Kasei Wacker Silicone Co., Ltd.). As the siloxane-based binder (A), a partially hydrolyzed condensate of ethyl silicate 40 (trade name; manufactured by Colcoat Co., Ltd.) is particularly preferable.

The weight average molecular weight (Mw) of the siloxane-based binder (A) contained in the first agent is usually 500 to 10,000, preferably 700 to 9,000, more preferably 800 to 5,000. When the Mw of the siloxane-based binder (A) is 500 or more, the coating composition of the present embodiment tends to have high drying properties, and the coating film of the present embodiment tends to have high corrosion resistance. On the other hand, when the Mw of the siloxane-based binder (A) is 10,000 or less, the storage stability of the first agent is good, and when the coating composition of this embodiment is applied to an overthick film, it is applied. Membrane cracking tends to occur less easily.

The weight average molecular weight (Mw) of the siloxane-based binder (A) can be measured by gel permeation chromatography (GPC) method. The value obtained by the GPC method is a value (polystyrene conversion value) obtained by using a calibration curve prepared using polystyrene as a standard substance.

The first agent may contain one kind or two or more kinds of siloxane-based binders (A).
The siloxane-based binder (A) can be produced by using a conventionally known method. For example, the compound (A1) and/or its low condensate can be mixed with an appropriate amount of water and, if necessary, in an organic solvent. It can be produced by carrying out a partial hydrolysis condensation reaction in the presence of a catalyst so that the weight average molecular weight (Mw) becomes a desired value.

Examples of the organic solvent include organic solvents described in the section <Organic solvent> described later.
The amount of water used is usually 5 to 11 parts by mass, preferably 5.5 to 9 parts by mass, relative to 100 parts by mass of the compound (A1) and/or its low condensate.

Examples of the catalyst include inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid; formic acid; organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, dioctyltin maleate, tin octylate; Phosphoric acid or phosphoric acid ester such as phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate; diisopropoxybis Organic titanate compounds such as (acetylacetate)titanium and diisopropoxybis(ethylacetoacetate)titanium; organoaluminum compounds such as tris(ethylacetoacetate)aluminum and tris(acetylacetonato)aluminum; tetrabutylzirconate, tetrakis( Examples thereof include organic zirconium compounds such as (acetylacetonato)zirconium, tetraisobutylzirconate, and butoxytris(acetylacetonato)zirconium. Among these, inorganic acids are preferable, and hydrochloric acid is more preferable, because the storage stability of the first agent is good.

When a catalyst is used, its amount is usually 0.01 to 2.0 parts by mass, preferably 0.02 to 1.30 parts by mass based on 100 parts by mass of the compound (A1) and/or its low condensate. It is 0 part by mass.

The boron compound described below can be used during the production of the siloxane-based binder (A). By introducing a structure derived from a boron compound into the siloxane-based binder (A), the dry curability of the coating composition of this embodiment can be improved.

Examples of the boron compound include boric acid and boron trioxide.
When the boron compound is used, its amount is usually 0.3 to 11 parts by mass, preferably 1.5 to 7 parts by mass, relative to 100 parts by mass of the compound (A1) and/or its low condensate. Is.

The content ratio of the siloxane-based binder (A) is obtained by converting the mass of the siloxane-based binder (A) into the mass of SiO ₂ (that is, the mass of the siloxane-based binder (A) is If the solid content of the coating composition of this embodiment is 100% by mass, it is usually 1 to 15% by mass (converted into the mass of SiO _{2 in} the same amount as the substance amount (mol) of Si atoms contained in A)). , Preferably 2 to 10% by mass, more preferably 3 to 8% by mass.

Further, the content ratio of the siloxane-based binder (A) is obtained by converting the mass of the siloxane-based binder (A) into the mass of SiO ₂ (that is, the mass of the siloxane-based binder (A) is converted into the siloxane-based bond (A)). If the solid amount of the first agent is 100% by mass (converted to the mass of SiO _{2 in} the same amount as the substance amount (mol) of Si atoms contained in the agent (A)), usually 10 to 70% by mass, preferably Is 20 to 60% by mass, more preferably 30 to 50% by mass.

When the content ratio of the siloxane-based binder (A) is within the above range, the coating film of this embodiment is excellent in corrosion resistance, crack resistance, and adhesion to a substrate.
In addition, the solid content of the coating composition or the first agent of the present embodiment means a residue (heating after heating the coating composition or the first agent containing a volatile component such as a solvent in a hot air dryer under the following conditions. The balance). The heating residue of the coating composition and the first agent can be measured according to the standard of JIS K 5601 1-2 (heating temperature: 125° C., heating time: 60 minutes).

The hydrolysis rate of the siloxane-based binder (A) is preferably 35 to 75%, more preferably 38 to 55%. When the hydrolysis rate of the siloxane-based binder (A) is within the above range, the first agent having more excellent storage stability can be obtained, and the drying property and the case of using an overthick film can be obtained. It is possible to obtain a coating composition having more excellent crack resistance.

When the siloxane-based binder (A) is a partially hydrolyzed condensate of the compound (A1) and/or a low condensate of the compound (A1), the hydrolysis rate (%) is tetraalkoxysilane, alkyltrialkoxysilane, or It means the reaction rate of the reactive group (alkoxy group) contained in the low condensate, and can be calculated by the following formula 1.

Hydrolysis rate (%)=(W/18×2/(S/E))×100 (Formula 1)
In Formula 1, W is the mass (g) of water used in preparing the siloxane-based binder (A), S is the mass (g) of tetraalkoxysilane, alkyltrialkoxysilane, and the low condensate, and E Is the reactive group equivalent of tetraalkoxysilane, alkyltrialkoxysilane and the low condensate.

<Kaolin (B)>
The first agent contains kaolin (B). Although the reason is not clear, long-term storage stability is improved when a pigment (C) having a Mohs hardness of 5 or more is included in the first agent containing the siloxane-based binder (A) in order to improve the slip coefficient of the coating film. When kaolin (B) is further included in the first agent, the first agent exhibits excellent long-term storage stability, and the kneadability between the first agent and the second agent becomes good. As a result, it becomes possible to stably supply the coating composition. Here, examples of the storage stability index include pigment sedimentation and/or gelation.

Kaolin (B) is usually a layered inorganic pigment produced from naturally occurring clay (mineral name: kaolinite (chemical formula: Al ₂ O ₃ .2SiO ₂ .2H ₂ O)). Kaolin (B) usually has a scaly thin flat shape. The kaolin (B) is not particularly limited, and examples thereof include wet kaolin, dry kaolin, and calcined kaolin.

The median diameter of kaolin (B) is preferably 0.1 to 10 μm, more preferably 0.2 to 5 μm. In the present specification, the median diameter is measured by a laser diffraction method.

The first agent may contain one kind or two or more kinds of kaolin (B).
The content ratio of kaolin (B) is usually 5 to 80% by mass, preferably 10 to 50% by mass in 100% by mass of the solid content of the first agent. When the content ratio of kaolin (B) is 5% by mass or more, the storage stability of the first agent tends to be better, while when it is 80% by mass or less, the coating film of the present embodiment is slippery. The coefficient tends to decrease.

Further, the content ratio of kaolin (B) is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass based on 100% by mass of the solid content of the coating composition of the present embodiment.

<Pigment (C) having a Mohs hardness of 5 or more>
The first agent contains a pigment (C) having a Mohs hardness of 5 or more (hereinafter also referred to as “pigment (C)”). By including the pigment (C) in the first agent, the slip coefficient of the coating film of the present embodiment is increased.

The Mohs hardness of the pigment (C) is 5 or more, preferably 5 or more and 8 or less, more preferably 5.5 or more and less than 7.5. The Mohs hardness can be measured according to a 10-step Mohs hardness meter.

Examples of the pigment (C) include iron oxides such as yellow iron oxide, red iron oxide, and black iron oxide; feldspars such as potassium feldspar, orthoclase, microcline feldspar, albite, and anorthite; silica and pumice. Among them, yellow iron oxide, potassium feldspar, and silica are preferable from the viewpoints of high slip coefficient and excellent storage stability.

The shape of the pigment (C) is not particularly limited, but various shapes such as spherical shape, needle shape, plate shape, scale shape, and fiber shape can be used. In one embodiment, the median diameter of pigment (C) is 0.1 to 50 μm.

Yellow iron oxide is usually acicular particles. The median diameter of the yellow iron oxide is preferably 0.1 to 30 μm, more preferably 0.2 to 20 μm.
Potassium feldspar is usually a particle having a shell-shaped fracture obtained by crushing from orthoclase. The median diameter of potassium feldspar is preferably 1 to 50 μm, more preferably 2 to 30 μm.

As the silica, fine powder silica having an average primary particle diameter of 1 μm or less is preferable. The average primary particle size of the fine powder silica is preferably 5 to 100 nm. The specific surface area of the fine powder silica is preferably 50 m ² /g or more. The finely powdered silica may be surface-treated or untreated. In the present specification, the nano-sized average primary particle diameter is the average value of the number of major axes of the primary particles observed with an electron microscope.

In one embodiment, the pigment (C) preferably contains finely divided silica, more preferably yellow iron oxide and/or potassium feldspar and finely divided silica from the viewpoint of the slip coefficient of the coating film.

The first agent may contain one kind or two or more kinds of pigments (C).
The content ratio of the pigment (C) is usually 5 to 70% by mass, preferably 10 to 50% by mass based on 100% by mass of the solid content of the first agent. If the content ratio of the pigment (C) is 5% by mass or more, the slip coefficient of the coating film of the present embodiment tends to be high, while if it is 70% by mass or less, the storage stability of the first agent is It tends to be difficult to decrease.

The content ratio of the pigment (C) is preferably 1 to 10% by mass, more preferably 2 to 6% by mass based on 100% by mass of the solid content of the coating composition of the present embodiment.

<Curing accelerator (D)>
The first agent can contain a curing accelerator (D).
Examples of the curing accelerator (D) include boric acid, boron compounds such as boron trioxide, oxalic acid, ferric chloride, and zinc chloride. Of these, boron compounds such as boric acid and boron trioxide are preferable from the viewpoint of storage stability and crack resistance.

The curing accelerator (D) acts, for example, as a curing catalyst when the coating composition applied on the substrate is cured to form a coating film.
The 1st agent can contain 1 type(s) or 2 or more types of hardening accelerator (D).

When the curing accelerator (D) is used, its content is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass based on 100% by mass of the solid content of the first agent. When the content ratio of the curing accelerator (D) is within the above range, the storage stability of the siloxane-based binder (A) is improved, and the drying property of the coating composition of the present embodiment and the crack resistance of the coating film are also improved. It tends to be excellent.

<Organic resin (E)>
The first agent may contain an organic resin (E) other than the siloxane-based binder (A) within a range that does not impair the objects and effects of the present invention. Examples of the organic resin (E) include butyral resin such as polyvinyl butyral resin and acrylic resin.

Examples of the polyvinyl butyral resin include S-REC BM-1, S-REC BM-2, and S-REC BL-1 (trade name; manufactured by Sekisui Chemical Co., Ltd.), and examples of the acrylic resin include DIALAL BR-106 ( Trade name: manufactured by Mitsubishi Chemical Corporation.

The 1st agent can contain 1 type(s) or 2 or more types of organic resin (E).
When the organic resin (E) is used, its content is preferably 0.1% in 100 mass% of the solid content of the first agent from the viewpoint of the coating workability of the coating composition and the crack resistance of the coating film. It is 1 to 10% by mass, more preferably 0.5 to 8% by mass.

<Thickener (F)>
The first agent may contain a generally known thickener (F). The thickener (F) can improve the kneadability between the first agent and the second agent described later.

As the thickener (F), conventionally known thickeners can be used without limitation. Examples of the thickener (F) include organic thickeners such as polyamide wax, polyethylene wax, and oxidized polyethylene wax; and inorganic substances such as bentonite (organic bentonite) whose surface is treated with quaternary ammonium salt. Examples include system thickeners.

The 1st agent can contain 1 type(s) or 2 or more types of thickener (F).
When the thickening agent (F) is used, its content is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass based on 100% by mass of the solid content of the coating composition of the present embodiment. %.

<Organic solvent>
The first agent usually contains an organic solvent for the purpose of dilution, improvement of storage stability, improvement of pot life, and the like.

The organic solvent includes, for example, at least one organic solvent (S1) selected from glycol ether solvents, ketone solvents and acetic acid ester solvents. Compared with the first agent containing no organic solvent (S1), the first agent containing an organic solvent (S1) has improved storage stability of the siloxane-based binder (A). It is speculated that this is because the silanol groups that the siloxane-based binder (A) may have are stabilized by hydrogen bonds with the oxygen atoms of the organic solvent (S1), and the condensation reaction thereof is suppressed.

Examples of glycol ether solvents include propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, with propylene glycol monomethyl ether being preferred. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and methyl ethyl ketone is preferable. Examples of the acetic acid ester solvent include ethyl acetate and butyl acetate, and ethyl acetate is preferable. Among these, glycol ether solvents are preferable, and propylene glycol monomethyl ether is more preferable.

The 1st agent can contain 1 type(s) or 2 or more types of organic solvent (S1).
The first agent may contain an organic solvent (S2) other than the organic solvent (S1) in order to adjust the drying property of the coated composition.

Examples of the organic solvent (S2) include organic solvents that are normally used in the paint field, such as alcohol solvents, aromatic solvents and cellosolve solvents. Examples of alcohol solvents include methanol, ethanol, isopropanol, and butanol. Examples of aromatic solvents include benzene, xylene, and toluene. Examples of the cellosolve solvent include methyl cellosolve, ethyl cellosolve, and butyl cellosolve.

The first agent may contain one kind or two or more kinds of organic solvents (S2).
The content ratio of the organic solvent in the first agent is not particularly limited, but is usually 10 to 80% by mass, preferably 25 to 60% by mass.

<Preparation of the first agent>
The first agent is, for example, a siloxane-based binder (A), kaolin (B) and a pigment (C) having a Mohs hardness of 5 or more, and if necessary, the above-mentioned components (D) to (F), an organic solvent and the like. Obtained by mixing.

<<Second agent>>
<Zinc powder (X)>
The second agent contains zinc powder (X). The zinc powder (X) is not particularly limited in shape, size, etc., and those conventionally known in the paint field can be used.

Examples of the zinc powder (X) include powder of metallic zinc and powder of zinc alloy. Examples of the zinc alloy include an alloy of zinc and at least one selected from aluminum, magnesium and tin. Examples of the shape of the particles forming the zinc powder (X) include various shapes such as spherical shape and scale shape.

The median diameter of the zinc powder (X) is 1 to 30 μm.
The second agent can contain one kind or two or more kinds of zinc powder (X).
The content of the zinc powder (X) is usually 30 to 98% by mass, preferably 50 to 97% by mass, and more preferably 65 to 95% by mass in 100% by mass of the solid content of the coating composition of the present embodiment. is there. When the content ratio of the zinc powder (X) is within the above range, the coating film of the present embodiment has excellent rust preventive properties over a long period of time. Therefore, the coating composition of the present embodiment is useful as a so-called inorganic zinc rich paint.

≪Other ingredients≫
The first agent and/or the second agent, or the coating composition of the present embodiment, the pigment dispersant, an extender other than kaolin (B) and the pigment (C), and a coloring agent for the purpose of ensuring various coating properties. Other components such as pigments, rust preventive pigments and adhesion-imparting agents can be further contained. The other components may be used alone or in combination of two or more.

[Usage form of coating composition kit, manufacturing method of coating composition]
In one embodiment, the paint composition kit of the present embodiment manufactures a first agent and a second agent by a paint manufacturer and provides them separately to a painter, and the painter prepares the first agent and the second agent. And are mixed before coating, and the resulting coating composition is coated. The coating composition kit of the present embodiment may further include, for example, a third agent containing at least one component selected from the above components and the like.

In the present embodiment, kaolin (B) and pigment (C) are included in the first agent. When these pigments are included in the second agent containing the zinc powder (X), a step of mixing and classifying the pigment powders may be necessary, and a step of classifying the powders after storage may be necessary. In one embodiment, this embodiment does not require a step of mixing zinc powder (X) with kaolin (B), a pigment (C), or the like in the second agent, and thus simplifies the manufacturing process. it can.

The coating composition of the present embodiment can be obtained by mixing at least the first agent and the second agent in the coating composition kit of the present embodiment. For example, the first agent and the second agent are sufficiently stirred and homogenized by using a stirrer.

The coating composition of this embodiment has excellent dryness. By using the coating composition, it is possible to form a coating film having excellent corrosion resistance and crack resistance in a thick film and having a high slip coefficient.

The coating film of the present embodiment is formed from the coating composition of the present embodiment and is useful as an anticorrosion/rustproof coating film. The base material with a coating film of the present embodiment has a base material and the coating film of the present embodiment. For example, the coating composition and the coated substrate of the present embodiment can be obtained by applying the coating composition of the present embodiment on the surface of the substrate and curing the coating composition.

Examples of the base material include conventionally known base materials such as steel materials, and specific examples thereof include ship structures such as ships, civil engineering structures such as bridges and tanks, plant structures such as oil drilling plants, and pipes. Steel structures such as lines; building structures such as houses and buildings; outdoor equipment such as guard fences and industrial machines. The coating composition of the present embodiment is applied to the surface of these base materials as the first anticorrosion coating film. Generally, the base material to which the coating composition of the present embodiment is applied is subjected to the blast treatment under the conditions corresponding to the degree of rust removal Sa21/2 or more in ISO8501-1. Further, if necessary, an undercoat paint, an intermediate coat paint and a top coat paint are applied onto the coating film obtained from the coating composition of the present embodiment.

In one embodiment, specifically, the base material includes a steel material that can be bolted, and the coating composition of the present embodiment is applied to a joint surface of a steel material at a bolted joint portion. At this joint surface, other paint is not coated on the coating film coated with the coating composition of the present embodiment, and the joint surfaces coated with the coating film of the coating composition of the present embodiment are bonded to each other. As a result, a frictional force with a slip coefficient of 0.5 or more is exhibited.

As a coating method of the coating composition of the present embodiment, air spray and airless spray are usually mentioned. The curing method of the coating composition after coating is not particularly limited, and a conventionally known curing method can be applied. For example, when a coating composition applied on a substrate is left to stand in the air (while being heated if necessary), the solvent volatilizes, and the siloxane-based binder (A) becomes water or air in the coating composition. It is cured by a hydrolysis-condensation reaction due to the water content (moisture) therein. In one embodiment, the coating conditions are typically 5-40°C.

The average dry film thickness of the coating film of the present embodiment is preferably 40 μm or more, more preferably 40 to 120 μm. The average dry film thickness of the coating film may be less than 40 μm, which is a thin film, depending on the state of the substrate to be coated and the application. The coating film of the present embodiment is excellent in crack resistance even when the average dry film thickness is more than 120 μm, for example, more than 120 μm and 200 μm or less.

The slip coefficient of the coating film of this embodiment is preferably 0.5 or more, more preferably 0.55 or more, and the upper limit is not particularly limited, but may be 0.8. Due to the coating film having a high slip coefficient of 0.5 or more, it is not necessary to increase the size of the reinforcing material such as the splicing plate used for the joint portion of the steel material for the sake of safety at the time of bolting and joining work, and the bolt to be tightened. Since it is not necessary to increase the number, it is preferable in terms of work cost.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In the following description, "parts by mass" will be referred to as "parts" unless otherwise specified.

Details of each component described in the table are as follows.
・Alkyl silicate "Ethyl silicate 40": made by Colcoat Co., Ltd. ・Zinc powder "F-500": made by Honjo Chemical Co., Ltd. ・Kaolin "ASP 200": made by BASF Japan Ltd. ・Talc "FC-1 talc" : Mica "Mica powder 325 mesh" manufactured by Fukuoka Talc Industry Co., Ltd.: Calcium carbonate "Calfine 200M-C" manufactured by Fukuoka Talc Industry Co., Ltd.: Yellow iron oxide "TSY-" manufactured by Maruo Calcium Co., Ltd. 1": Potash feldspar "UNISPAR PG-K10" manufactured by Toda Kogyo Co., Ltd.:
Sibelco Malaya Sdn Bhd-Fine powder silica "AEROSIL R972": Nippon Aerosil Co., Ltd.-Acrylic resin "Dianal BR-106": Mitsubishi Chemical Co., Ltd.-Polyvinyl butyral resin "ESREC BM-2": Sekisui Chemical Polyamide wax "Disparon A630-20X" manufactured by Kusumoto Kasei Co., Ltd. Organic bentonite "BENTONE SD-2" manufactured by Kusumoto Kasei Co., Ltd.: Elementis Specialties, Inc. Made

[Preparation example]
28.00 parts of ethyl silicate 40, 39.42 parts of propylene glycol monomethyl ether (PGM), 6.92 parts of ethanol (technical ethanol), 1.56 parts of deionized water and 0 as a catalyst. 10 parts of 35% hydrochloric acid was charged in the container (1), 1.00 parts of boron trioxide was charged in the container (1), and the mixture was stirred at 25° C. for 1 hour and 30 minutes, and then left to cool for 16 hours. ..

Further, in another container (2), 1.00 parts of acrylic resin and 5.00 parts of xylene were charged and stirred at 25° C. for 30 minutes to prepare an acrylic resin varnish.
Next, 10.00 parts of kaolin, 6.00 parts of yellow iron oxide, and 1.00 parts of finely powdered silica were charged into a container (1) that had been allowed to cool for 16 hours while stirring at 25° C., Finally, 6.00 parts of the acrylic resin varnish prepared in advance in the container (2) was charged, and the mixture was stirred at 25° C. until it became uniform to prepare the first agent (I-1).

Further, the same operation as in the preparation of the first agent (I-1) was performed except that the kind and the charging amount of each raw material were changed as shown in Tables 1-1 and 1-2, and the first agent (I- 2) to (I-16) and (cI-1) to (cI-4) were prepared.

<Weight average molecular weight (Mw) of siloxane-based binder (A)>
Weight average molecular weight of the siloxane-based binder (A) in the first agents (I-1) to (I-16) and (cI-1) to (cI-4) in the initial stage (about 1 day after preparation) (Mw) was measured by gel permeation chromatography (GPC) method.

The measurement conditions of GPC are as follows. A small amount of each of the first agents was taken and diluted with tetrahydrofuran, and the resulting solution was filtered through a membrane filter to obtain a GPC measurement sample.
・Apparatus: 2695 Separation Module (Aliance GPC Multi System) manufactured by Japan Waters Co., Ltd.
・Column: TOSgel Super H4000 manufactured by Tosoh Corporation
TSKgel Super H2000
TSKgel Super H2000
Measured by connecting the above three in series.
・Eluent: Tetrahydrofuran (THF)
・Flow rate: 0.6 ml/min ・Detector: Shodex RI-104
・Column constant temperature bath temperature: 40℃
・Standard substance: polystyrene

<Hydrolysis rate of siloxane-based binder (A)>
The hydrolysis rate of the siloxane-based binder (A) was calculated based on the above-mentioned formula 1.

[Examples 1 to 16 and Comparative Examples 1 to 4]
The second agent and the first agent, which was stored at 23° C. for 1 month after preparation, were charged in a polyethylene container at a ratio (parts by mass) shown in Tables 1-1 and 1-2, and a high-speed disperser was used for 10 A dispersion treatment was carried out for a minute to prepare a coating composition.

[Evaluation test]
<Storage stability>
The first agents (I-1) to (I-16) and (cI-1) to (cI-4) obtained in Preparation Example are shown in Table 2 from the state after storage at 23° C. for 12 months. The storage stability was evaluated according to the standard.

In addition, the siloxane-based binder (A) in the first agents (I-1) to (I-16) and (cI-1) to (cI-4) that have been stored for 1 month, 6 months, and 12 months at 23°C. The weight average molecular weight (Mw) of was measured by the GPC method.

<Drying property>
Each coating composition obtained in Examples and Comparative Examples was applied to a sandblasted steel plate (150 mm×70 mm×2.3 mm, Sa2 1/2 or more) by air spraying so that the dry film thickness was 75 μm, and the temperature was 25° C. While drying under the condition of 70% relative humidity, the coating film is rubbed with methyl ethyl ketone (MEK) 50 times every hour to measure the time until the coating film does not dissolve, and dried according to the criteria shown in Table 2. The sex was evaluated.

<Corrosion resistance>
Each coating composition obtained in Examples and Comparative Examples was applied to a sandblasted steel plate (150 mm×70 mm×2.3 mm, Sa2 1/2 or more) by air spraying so that the dry film thickness was 75 μm, and the temperature was 25° C. After drying for 7 days under the condition of 70% relative humidity, a test coated plate was prepared, and exposed to the outdoors (Otake City, Hiroshima Prefecture) for 2 years. The degree of occurrence was evaluated according to the criteria shown in Table 2.

<Crack resistance>
Each coating composition obtained in Examples and Comparative Examples was applied to a sandblasted steel plate (150 mm×70 mm×2.3 mm, Sa2 1/2 or more) by air spraying so that the dry film thickness was 200 μm, and the temperature was 25° C. , 70% relative humidity, and dried for 7 days to prepare a coated plate for a crack resistance test. The surface condition was observed, and the crack resistance was evaluated according to the criteria shown in Table 2.

<Slip coefficient>
Each of the coating compositions obtained in Examples and Comparative Examples was applied by air spray to both sides of the grid-blasted SM490 plate by air spraying to a dry film thickness of 75 μm, followed by drying for one month, and a coating test. Got the body The prepared coated test piece was tightened with a torcia-type high-strength TC bolt (M22), the slip coefficient was measured using a tensile tester, and evaluation was performed according to the criteria shown in Table 2.

Claims

A first agent containing a siloxane-based binder (A), kaolin (B) and a pigment (C) having a Mohs hardness of 5 or more;
A coating composition kit having a second agent containing zinc powder (X).
The coating composition kit according to claim 1, wherein the siloxane-based binder (A) has a weight average molecular weight (Mw) of 500 to 10,000.
The coating composition kit according to claim 1 or 2, wherein the siloxane-based binder (A) is a condensate of at least one compound (A1) selected from tetraalkoxysilane and alkyltrialkoxysilane.
The coating composition kit according to any one of claims 1 to 3, wherein the pigment (C) contains at least one selected from yellow iron oxide, potassium feldspar, and silica.
A coating composition obtained by mixing at least the first agent and the second agent in the coating composition kit according to any one of claims 1 to 4.
A method for producing a coating composition, comprising a step of mixing at least the first agent and the second agent in the coating composition kit according to any one of claims 1 to 4.
A coating film formed from the coating composition according to claim 5.
A substrate with a coating, which comprises the substrate and the coating according to claim 7.
The base material with a coating according to claim 8, wherein the base material is a steel material constituting a steel structure.
A steel material with a coating, comprising a steel material and the coating film according to claim 7 formed on a joint surface of a bolted joint portion of the steel material.