JP2021154217A - Film formation method - Google Patents

Abstract

To provide a film formation method for coating an undercoating material to a base material, and then coating a final coating material containing a specific oxidation curable resin as an essential component thereto.SOLUTION: A film formation method for coating an undercoating material to a base material, and then coating a final coating material thereto, in which the final coating material contains an oxidation curable resin (A), a metal drier (B) and an aliphatic hydrocarbon-containing solvent, and the oxidation curable resin (A) has an amine value of 0.1 mgKOH/g or more and contains 5 wt.% or more and 50 wt.% or less of an alkyd resin.SELECTED DRAWING: None

Description

The present invention relates to a novel film forming method.

Conventionally, in buildings, civil engineering structures, etc., various covering materials (undercoating material, topcoating material, etc.) are laminated to form a film for the purpose of imparting functionality to the base material, protecting it, and improving its aesthetic appearance. The finish is done. In recent years, in the field of such coating materials, the use of aromatic hydrocarbon-containing solvents such as toluene and xylene has been suppressed in consideration of safety during painting, work hygiene, and the effect on air pollution. The movement is getting stronger. In order to cope with such movement, various environment-friendly coating materials using an aliphatic hydrocarbon-containing solvent have been proposed.

Further, as such an environment-friendly coating material, a coating material using an oxidation-curable resin is known (Patent Document 1 and the like). Patent Document 1 is a one-component crosslinkable (curable type) coating material that causes a crosslink reaction by oxidizing reactive double bonds contained in unsaturated fatty acids. A coating material containing such an oxidation-curable resin is widely used as a topcoat material because it has excellent gloss and workability.

Japanese Unexamined Patent Publication No. 2001-262855

However, when such an environment-friendly coating material is used as the topcoat material, the adhesion of the topcoat material may be insufficient depending on the type of the undercoat material, and lifting or the like may occur. In addition, there was a case where the glossiness was also taken.

The present invention has been made in view of these points, and in a film forming method in which an undercoat material is applied to a base material and then a topcoat material containing an oxidation-curable resin is applied, adhesion and resistance are achieved. The purpose is to improve the lifting property and the like.

In order to solve such a problem, as a result of diligent studies, the present inventors apply an undercoat material to the base material, and then apply a topcoat material containing a specific oxidation-curable resin as an essential component. We came up with a film forming method and completed the present invention.

That is, the present invention has the following features.
1. 1. A film forming method in which an undercoat material is applied to a base material and then a topcoat material is applied.
The topcoat material contains an oxidation-curable resin (A), a metal dryer (B), and an aliphatic hydrocarbon-containing solvent.
The film forming method, wherein the oxidation-curable resin (A) has an amine value of 0.1 mgKOH / g or more and contains an alkyd resin in an amount of 5% by weight or more and 50% by weight or less.
2. The oxidation-curable resin (A) is characterized by being an alkyd resin-modified acrylic resin. The film forming method according to.
3. 3. The undercoat material is characterized by containing an epoxy resin. Or 2. The film forming method according to.

According to the film forming method of the present invention, it is possible to form a film having excellent adhesion to the undercoat material, lifting resistance and the like. Further, it is possible to obtain an advantageous effect in terms of finish such as gloss.

Hereinafter, modes for carrying out the present invention will be described.

The present invention relates to a film forming method in which an undercoat material is applied to a base material and then a topcoat material is applied, mainly for protection of a skeleton and improvement of aesthetics in a building, a civil engineering structure, or the like. Can be applied. In particular, the present invention is characterized in that a topcoat material containing a specific oxidation-curable resin as an essential component is applied.

<Base material>
The present invention is mainly used for protecting the skeleton of buildings, civil engineering structures, etc. For example, concrete, mortar, porcelain tile, siding board, extruded plate, colored steel plate, copper plate, aluminum plate, titanium plate. , Stainless steel plate, galvanized steel plate, metal, glass, plastic, wood, plywood and other various base materials can be used for surface finishing. These base materials may have an old coating film on the surface thereof.
In the film forming method of the present invention, the undercoat material can be directly coated on the base material, but some surface treatment (base treatment with an undercoat material such as sealer, primer, surfacer, filler, putty, etc.) is applied to the base material in advance. It is also possible.

<Undercoat material>
As the undercoat material of the present invention, various known or commercially available undercoat materials can be used. Specific examples of the undercoat material include an acrylic resin undercoat material, an epoxy resin undercoat material, a urethane resin undercoat material, and a chlorinated rubber-based undercoat material. Such an undercoat material may be either a clear type or a colored type. Further, it may contain a rust preventive pigment such as phosphate-based, molybdate-based, and zinc-based.

Of these, in the present invention, a remarkable effect can be obtained when an epoxy resin undercoat material is used. Usually, when a topcoat material containing an oxidation-curable resin and a metal dryer is coated on an epoxy resin undercoat material, the reactivity of the topcoat material may decrease due to the interaction between the undercoat material and the metal dryer. Therefore, when the topcoat material is applied twice or more, the phenomenon that the topcoat material coating film of the lower layer is melted or the phenomenon of floating (lifting) is likely to occur. On the other hand, in the present invention, by using a specific topcoat material, it is possible to suppress the occurrence of such a defect, to have excellent adhesion and lifting resistance, and to improve the finish.

As the epoxy resin undercoat material, a material containing one or more kinds of epoxy resins as a binder component can be used. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, alkyl ether type epoxy resin, hydrogenated bisphenol A type epoxy resin, and modified products thereof.
The form of the epoxy resin undercoat material may be either a one-component type or a two-component type. In the case of the two-component type, a curing agent containing an amine compound or the like can be used.

The undercoat material may contain the above binder component as an essential component, and may contain various components to the extent that it does not affect the effects of the present invention. Examples of such components include coloring pigments, extender pigments, rust preventives, thickeners, film-forming aids, leveling agents, plasticizers, antifreeze agents, pH adjusters, diluents, preservatives, and fungicides. Examples thereof include agents, algae-proofing agents, antibacterial agents, dispersants, antifoaming agents, ultraviolet absorbers, antioxidants, light stabilizers, fibers, catalysts, cross-linking agents and the like.

Such an undercoat material can be coated by using various methods such as brush coating, roller coating, spray coating, roll coater, and flow coater. The amount to be applied depends on the form of the undercoat material, but is preferably 0.05 to 3 kg / m ² (more preferably 0.05 to ² kg / m 2).

<Topcoat material>
The topcoat material of the present invention contains an oxidation-curable resin (A), a metal dryer (B), and an aliphatic hydrocarbon-containing solvent, and is a so-called weak solvent type coating material.

The oxidatively curable resin (A) of the present invention (hereinafter, also referred to as “component (A)”) is air-oxidized and cured and dried by an oxidatively polymerizable double bond (oxidatively polymerizable group). The component (A) is not particularly limited as long as it has an oxidatively polymerizable group, but the resin type thereof is not particularly limited, and examples thereof include acrylic resin, polyester resin, polyurethane resin, and epoxy resin. can.

The present invention preferably contains an oxidation-curable acrylic resin as the component (A). In the present invention, the oxidatively curable acrylic resin preferably contains an alkyd resin-modified acrylic resin, and specifically, the following resins can be used.
1) A resin obtained by polymerizing an alkyd resin with a vinyl monomer copolymerizable and / or graft-polymerizable with the alkyd resin.
2) A resin obtained by reacting an alkyd resin with an acrylic resin having a group (carboxyl group, hydroxyl group, epoxy group, etc.) reactive with the alkyd resin.

As the alkyd resin in 1) and 2) above, a resin obtained by subjecting a polyhydric alcohol, a polybasic acid, an unsaturated fatty acid and / or a fat or oil to a condensation reaction can be used.

Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and hexanediol, and 3 such as glycerin and trimethylolpropane. Convalent alcohols, such as tetrahydric alcohols such as pentaerythritol, and hexahydric alcohols such as dipentaerythritol, mannitol, D-sorbitol and the like can be mentioned. These can be used alone or in combination of two or more.

Examples of the polybasic acid include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, succinic anhydride, maleic acid, maleic anhydride, adipic acid, sebacic acid, tetrahydrophthalic anhydride and the like. These can be used alone or in combination of two or more.

The unsaturated fatty acid is not particularly limited as long as it is a fatty acid having at least one oxidatively polymerizable group (unsaturated carbon bond) in the molecule, and examples thereof include known unsaturated fatty acids. Examples of unsaturated fatty acids include drying oil fatty acids and semi-drying oil fatty acids. In the present invention, the drying oil fatty acid refers to a fatty acid having a solid iodine value of 130 or more, and the semi-drying oil fatty acid refers to a fatty acid having a solid iodine value of 100 or more and less than 130.

Examples of dry oil fatty acids and semi-dry oil fatty acids include fish oil fatty acids, dehydrated castor oil fatty acids, safflower oil fatty acids, flaxseed oil (linseed oil) fatty acids, tung oil fatty acids, soybean oil fatty acids, sesame oil fatty acids, poppy oil fatty acids, and eno oils. Fatty acids, hemp oil fatty acids, grape kernel oil fatty acids, corn oil fatty acids, tall oil fatty acids, sunflower oil fatty acids, cottonseed oil fatty acids, walnut oil fatty acids, rubber seed oil fatty acids, hygiene acid fatty acids, oleic acid, linoleic acid, linolenic acid, etc. Be done. These can be used alone or in combination of two or more.

Further, if necessary, a drying oil fatty acid and / or a semi-drying oil fatty acid can be used in combination with a non-drying oil fatty acid. In the present invention, the non-drying oil fatty acid refers to a fatty acid having a solid iodine value of less than 100. Examples of the non-drying oil fatty acid include coconut oil fatty acid, hydrogenated coconut oil fatty acid, palm oil fatty acid, caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and the like. These can be used alone or in combination of two or more.

Examples of fats and oils include fats and oils having an unsaturated carbon bond. Dry or semi-dry oils such as hemp seed oil, grape kernel oil, corn oil, tall oil, sunflower oil, cotton seed oil, walnut oil and rubber seed oil can be mentioned. These can be used alone or in combination of two or more.

As the alkyd resin in 1) and 2) above, a alkyd resin having an oxidative polymerizable group in which an unsaturated carbon bond derived from an unsaturated fatty acid and / or an oil or fat is introduced can also be used.

The component (A) of the present invention is characterized in that the content of the alkyd resin is 5% by weight or more and 50% by weight or less (preferably 10% by weight or more and 40% by weight) as a solid content in the solid content of the component (A). do. In such a case, excellent adhesion, lifting resistance and the like can be exhibited.

As the vinyl monomer constituting the vinyl monomer in 1) above or the vinyl monomer constituting the acrylic resin in 2) above, for example, (meth) acrylic acid alkyl ester is an essential component, preferably an aromatic monomer, and others. It contains vinyl monomer and the like.

Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and n-amyl (meth). Acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) Meta) Acrylate and the like can be mentioned. These can be used alone or in combination of two or more.

Examples of the aromatic monomer include styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene and the like. These can be used alone or in combination of two or more.

The component (A) of the present invention is characterized by having an amine value of 0.1 mgKOH / g or more (preferably 0.3 to 10 mgKOH / g, more preferably 0.5 to 8 mgKOH / g). The amine value of the component (A) can exert a remarkable effect on the adhesion with various undercoat materials and the improvement of lifting resistance, particularly when the epoxy resin is contained as the resin component of the undercoat material. The amine value is a value represented by the number of mg of potassium hydroxide equivalent to the acid group contained in 1 g of the solid content of the component (A).

In order to set the amine value of the component (A) within the above range, for example, it is preferable to use an amino group-containing vinyl monomer as the vinyl monomer during the polymerization of the component (A). As a result, adhesion and lifting resistance can be improved. Examples of the amino group-containing vinyl monomer include N-methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminoethyl vinyl ether, N- (2-dimethylaminoethyl) acrylamide, and N- (2). -Dimethylaminoethyl) Methacrylamide and the like can be mentioned. These can be used alone or in combination of two or more.

In the present invention, as other vinyl monomers, for example, a hydroxyl group-containing vinyl monomer, a carboxyl group-containing vinyl monomer, an epoxy group-containing vinyl monomer and the like can also be used.
Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate;
Examples of the carboxyl group-containing vinyl monomer include acrylic acid, methacrylic acid, crotonic acid, maleic acid or its monoalkyl ester, itaconic acid or its monoalkyl ester, fumaric acid or its monoalkyl ester;
Examples of the epoxy group-containing vinyl monomer include glycidyl (meth) acrylate, diglycidyl (meth) acrylate, allyl glycidyl ether, diglycidyl fumarate, 3,4-epoxycyclohexyl (meth) acrylate, and 3,4-epoxide vinyl. Cyclohexane, ε-caprolactone-modified glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, etc.;
Can be mentioned. These can be used alone or in combination of two or more.

In addition to the alkyd resin, the component (A) of the present invention may further introduce an oxidatively polymerizable group. In this case, for example, when polymerizing the component (A), a vinyl monomer having an oxidative polymerizable group is used, or a vinyl monomer in which an unsaturated fatty acid is added to an epoxy group-containing vinyl monomer is used. It is possible by such means. It is also possible to add unsaturated fatty acids to the epoxy group-containing resin obtained by copolymerizing the epoxy group-containing vinyl monomer and another vinyl monomer copolymerizable with this monomer. ..

Examples of the vinyl monomer having an oxidatively polymerizable group include a dicyclopentadieneoxyalkyl group-containing vinyl monomer such as dicyclopentadieneoxyalkyl (meth) acrylate and an allyl group-containing vinyl simpler such as allyl (meth) acrylate. Monomers can also be used. These can be used alone or in combination of two or more.

A vinyl monomer in which an unsaturated fatty acid is added to an epoxy group-containing vinyl monomer is obtained by reacting an epoxy group with a carboxyl group in an unsaturated fatty acid. Examples of the epoxy group-containing vinyl monomer include the same as above. Moreover, as the unsaturated fatty acid, the same thing as above can be mentioned.

The component (A) of the present invention may have an acid value. The acid value is preferably 0.1 to 30 mgKOH / g (more preferably 0.5 to 10 mgKOH / g, more preferably 1 to 8 mgKOH / g). With such an acid value of the component (A), the curability can be improved and the suitability for recoating can be improved. The acid value is a value represented by the number of mg of potassium hydroxide equivalent to the acid group contained in 1 g of the resin solid content. In order to set the acid value in the component (A) within the above range, for example, an alkyd resin having an acid value is used as the alkyd resin, or the carboxyl group-containing vinyl monomer or the like is used as the vinyl monomer. You can use it.

The metal dryer (B) in the coating material of the present invention is a component that acts as a curing catalyst for the component (A). As the component (B), for example, known organic metal compounds such as cobalt-based, manganese-based, zirconium-based, tin-based, lead-based, zinc-based, copper-based, iron-based, calcium-based, and barium-based can be used. Specifically, for example, cobalt octylate, cobalt naphthenate, manganese octylate, manganese naphthenate, zirconium octylate, zirconium naphthenate, tin octylate, lead naphthenate, zinc naphthenate, copper naphthenate, iron naphthenate, Examples thereof include calcium octylate, calcium naphthenate, barium octylate, barium naphthenate, and the like. These can be used alone or in combination of two or more.

The mixing ratio of the component (B) is preferably 0.001 to 10 parts by weight (more preferably 0.01 to 5 parts by weight) in terms of metal content with respect to 100 parts by weight of the solid content of the component (A).

The aliphatic hydrocarbon-containing solvent of the present invention is a non-aqueous solvent having lower toxicity, higher work safety, and less influence on air pollution than the aromatic hydrocarbon-containing solvent. Examples of the aliphatic hydrocarbon include n-hexane, n-pentane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane and the like. Further, in the present invention, terpin oil, mineral spirit, or the like can be used as the aliphatic hydrocarbon-containing solvent.

In the topcoat material of the present invention, in addition to the above-mentioned components, various components can be blended to the extent that the effects of the present invention are not affected. Examples of such components include coloring pigments, extender pigments, thickeners, film-forming aids, leveling agents, plasticizers, antifreeze agents, pH adjusters, diluents, preservatives, fungicides, and algae-proofing agents. Examples thereof include agents, antibacterial agents, dispersants, antifoaming agents, ultraviolet absorbers, antioxidants, light stabilizers, fibers, catalysts, cross-linking agents and the like.

The topcoat material of the present invention can be produced by uniformly stirring and mixing each of the above components by a conventional method. The topcoat material of the present invention can be used in the form of a one-component type.

The topcoat material of the present invention can be applied to the base material via the undercoat material coating film. At this time, the composition of the present invention can be appropriately diluted with an aliphatic hydrocarbon solvent. As a coating method, for example, various methods such as brush coating, roller coating, spray coating, roll coater, and flow coater can be used. The amount to be applied is preferably about ^{0.1 to 0.5 kg / m 2.} Further, the topcoat material may be finished with one layer, or two or more layers may be laminated for finishing.

Examples are shown below to clarify the features of the present invention.

(Top coating materials 1 to 5)
Using the raw materials shown below, they were mixed by a conventional method according to the formulation shown in Table 1 to produce topcoat materials 1 to 5.

The following raw materials were used for each topcoat material.
・ Oxidation-curable resin 1
Alkyd resin modified acrylic resin [Alkyd resin, styrene, isobutyl methacrylate, 2-ethylhexyl acrylate, dimethylaminoethyl methacrylate copolymer mineral spirit solution, amine value: 0.4 mgKOH / g, acid value: 3 mgKOH / g, solid content : 50% by weight (alkyd resin content in solid content: 22% by weight)]
・ Oxidation-curable resin 2
Alkyd resin modified acrylic resin [Alkyd resin, styrene, isobutyl methacrylate, 2-ethylhexyl acrylate, dimethylaminoethyl methacrylate copolymer mineral spirit solution, amine value: 2 mgKOH / g, acid value: 3 mgKOH / g, solid content: 50 Weight% (Alkyd resin content in solid content: 18% by weight)]
・ Oxidation-curable resin 3
Alkyd resin modified acrylic resin [Alkyd resin, styrene, isobutyl methacrylate, 2-ethylhexyl acrylate, dimethylaminoethyl methacrylate copolymer mineral spirit solution, amine value: 0.4 mgKOH / g, acid value: 3 mgKOH / g, solid content : 50% by weight (alkyd resin content in solid content: 8% by weight)]
・ Oxidation-curable resin 4
Alkyd resin modified acrylic resin [Alkyd resin, styrene, isobutyl methacrylate, 2-ethylhexyl acrylate copolymer mineral spirit solution, amine value: 0 mgKOH / g, acid value: 3 mgKOH / g, solid content: 50% by weight (solid content) Alkyd resin content in: 3% by weight)]
・ Oxidation-curable resin 5
Alkyd resin modified acrylic resin [Alkyd resin, styrene, isobutyl methacrylate, 2-ethylhexyl acrylate copolymer mineral spirit solution, amine value: 0 mgKOH / g, acid value: 3 mgKOH / g, solid content: 50% by weight (solid content) Alkyd resin content in: 8% by weight)]
-Metal dryer: A mixture of cobalt naphthenate and zirconium naphthenate (mineral spirit solution, Co content 0.3% by weight, Zr content 3% by weight)
・ Color pigment: Titanium oxide ・ Additives: Defoamers, dispersants, light stabilizers, etc. ・ Solvents: Non-aqueous solvents containing aliphatic hydrocarbons (mixture of mineral spirit and petroleum mixed solvent containing aromatic hydrocarbons, aliphatic hydrocarbons) Hydrogen content ratio: 65% by weight)

(Examples 1 to 3 and Comparative Examples 1 to 2)
A two-component reaction-curable epoxy resin undercoat material [main component: phenol novolac type epoxy resin with epoxy equivalent of 1350 g / eq, curing agent component: polyamide amine with active hydrogen equivalent of 360 g / eq] is applied to a 200 x 150 mm tin plate. It was brush-coated at an application rate of 0.1 kg / m ² and dried and cured for 24 hours under standard conditions.
Next, the topcoat material obtained by the above method is brush-coated with a coating amount of 0.12 kg / m 2, and after drying and curing for a predetermined time (24 hours, 48 hours), the same topcoat material is applied with a ^{coating amount of 0.12 kg / m 2.} those brushed with m ² and specimens were subjected to the following evaluation. The results are shown in Table 1.

(Evaluation of lifting resistance)
The surface condition of the test piece prepared by the above method was observed and evaluated in the following four stages.
・ "A" for those for which no abnormality was found
・ "B" for those with almost no abnormalities (those with slight shrinkage)
・ "C" for those with a lifting phenomenon (shrinkage on the entire surface)
・ "D" for those with a dissolution phenomenon

(Adhesion)
A crosscut was made into the coating film of the test piece prepared by the above method with a cutter knife, and the adhesiveness was evaluated by attaching a tape to the crosscut portion and peeling it off. The evaluation was carried out in four stages (excellent: A>B>C> D: inferior), in which no abnormality was observed was “A” and those in which peeling was observed were “D”.

(Finishness)
The finished appearance (color tone, gloss, etc.) of the test body prepared by the above method was visually confirmed. The evaluation was carried out in four stages (excellent: A>B>C> D: inferior) in which the one having excellent finish was "A" and the one having inferior finish was "D".

Claims (3)

A film forming method in which an undercoat material is applied to a base material and then a topcoat material is applied.
The topcoat material contains an oxidation-curable resin (A), a metal dryer (B), and an aliphatic hydrocarbon-containing solvent.
The film forming method, wherein the oxidation-curable resin (A) has an amine value of 0.1 mgKOH / g or more and contains an alkyd resin in an amount of 5% by weight or more and 50% by weight or less. The film forming method according to claim 1, wherein the oxidation-curable resin (A) is an alkyd resin-modified acrylic resin. The film forming method according to claim 1 or 2, wherein the undercoat material contains an epoxy resin.