JP7590879B2 - Film forming method and laminate - Google Patents

Description

The present invention relates to a novel method for forming a coating.

Conventionally, the surfaces of buildings, civil engineering structures, etc. have been covered with urethane resin coating materials containing plasticizers ("plasticizer-containing coating materials"). Such plasticizer-containing coating materials contain a polyol component, a polyisocyanate component, and a plasticizer. In addition, a coating material may be laminated on the surface of this plasticizer-containing coating material for protection, design, etc. However, the plasticizer may migrate into the coating material over time, and the aesthetics or adhesion may be reduced due to the adhesion of contaminants to the coating material surface.

In response to this, for example, Patent Document 1 proposes a non-migratory polymer plasticizer, which is described as not migrating to the surface due to its high molecular weight.

JP 2001-226442 A

However, generally, low molecular weight plasticizers are often used in plasticizer-containing coating materials, and there is a need to develop a coating method that can be applied to such plasticizer-containing coating materials.

To solve these problems, the inventors discovered that by forming a coating by applying a second coating material containing a specific polyol component (A) to the surface of a first coating material containing a polyol component, a polyisocyanate component, and a plasticizer, it is possible to form a coating that is excellent in preventing migration of the plasticizer and has excellent adhesion, leading to the completion of the present invention.

That is, the present invention has the following features.
1. A coating forming method for applying a first coating material and a second coating material, the first coating material containing a plasticizer, the first coating material and the second coating material containing a polyol component (A) and a polyisocyanate component (B) as resin components,
the first coating material and the second coating material each contain a polyether polyol (Ax) as the polyol component (A), and the second coating material contains a polyether polyol (Ax2) having a hydroxyl value larger than the polyether polyol (Ax1) of the first coating material .
2. The method for forming a coating film according to 1., wherein the polyether polyol (Ax2) contains a polyether polyol having a hydroxyl value of 50 mg KOH/g or more.
3. A laminate having a first coating formed from a first coating material and a second coating formed from a second coating material,
The first coating material contains a plasticizer, and the first coating material and the second coating material contain a polyol component (A) and a polyisocyanate component (B) as resin components,
the first coating material and the second coating material each contain a polyether polyol (Ax) as the polyol component (A), and the second coating material contains a polyether polyol (Ax2) having a hydroxyl value larger than the polyether polyol (Ax1) of the first coating material .
4. The laminate according to claim 3, wherein the polyether polyol (Ax2) contains a polyether polyol having a hydroxyl value of 50 mg KOH/g or more.

The present invention is a method for forming a coating by applying a first coating material and a second coating material, in which the first coating material contains a plasticizer, the first coating material and the second coating material contain a polyol component (A) and a polyisocyanate component (B) as resin components, and the second coating material contains a polyol component (A2) having a higher hydroxyl value than the polyol component (A1) of the first coating material, thereby forming a coating that is excellent in preventing plasticizer migration and has excellent adhesion.

The present invention will be described in detail below based on its embodiments.

The present invention relates to a method for forming a coating in which a first coating material and a second coating material are applied in that order. Both the first coating material and the second coating material in the present invention contain a polyol component (A) and a polyisocyanate component (B) as resin components. The second coating material contains a polyol component (A2) that has a higher hydroxyl value than the polyol component (A1) of the first coating material. First, common points between the first coating material and the second coating material (hereinafter, both are collectively referred to simply as "coating materials") will be explained.

The coating material of the present invention contains a polyol component (A) and a polyisocyanate component (B), which react to form a coating.

The polyol component (A) of the present invention (hereinafter also referred to as "component (A)") may be, for example, polyether polyol, polyester polyol, castor oil, castor oil modified polyol, epoxy modified polyol, silicone modified polyol, fluorine modified polyol, acrylic polyol, polycarbonate polyol, polylactone polyol, polybutadiene polyol, polypentadiene polyol, etc. The coating material of the present invention preferably contains one or more selected from polyether polyols and acrylic polyols. These polyols are preferably liquid at 20°C, and can also be used in the form of a solvent-soluble type, a non-aqueous dispersion (NAD) type, etc.

The polyether polyol (Ax) (hereinafter also referred to as "(Ax) component") is obtained by addition polymerization of polyhydric alcohols such as trimethylolpropane, glycerin, hexanetriol, pentaerythritol derivatives, sorbitol, and neopentyl glycol with alkylene oxides such as ethylene oxide and propylene oxide. In the present invention, a polymer obtained by addition polymerization of the above-mentioned polyhydric alcohols with ethylene oxide and/or propylene oxide is preferred, and one having ethylene oxide and/or propylene oxide added to the terminal can also be used. Furthermore, in the present invention, it is preferable that the (Ax) component contains a polyether polyol having three or more functional groups (hydroxyl groups) having active hydrogen atoms (functional group number 3 or more). In this case, the crosslink density of the formed coating can be increased, and the effects of the present invention can be fully exerted.

The acrylic polyol (Ay) (hereinafter also referred to as "(Ay) component") contains as constituents an alkyl (meth)acrylate ester, a hydroxyl group-containing monomer, and other monomers as necessary, and a polymer of these can be used. An alkyl (meth)acrylate ester is a compound having a (meth)acryloyl group and an alkyl group. In the present invention, an alkyl acrylate ester and an alkyl methacrylate ester are collectively referred to as an alkyl (meth)acrylate ester. A monomer is a general term for a compound having a polymerizable unsaturated double bond.

Examples of such (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, t-pentyl (meth)acrylate, 1-ethylpropyl (meth)acrylate, 2-methylbutyl (meth)acrylate, and Examples include 3-methylbutyl acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, 2-methylpentyl (meth)acrylate, 4-methylpentyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-undecyl (meth)acrylate, and n-lauryl (meth)acrylate. These can be used alone or in combination of two or more.

Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylate esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. These can be used alone or in combination of two or more.

Examples of the other monomers include aromatic monomers, carboxyl group-containing monomers, amino group-containing monomers, pyridine-based monomers, nitrile group-containing monomers, amide group-containing monomers, epoxy group-containing monomers, carbonyl group-containing monomers, alkoxysilyl group-containing monomers, fluorine-containing monomers, UV-absorbing group-containing monomers, and light-stable group-containing monomers. These can be used alone or in combination of two or more.

Furthermore, in the present invention, a polyester-containing acrylic polyol containing an acrylic polyol and a polyester can also be used as the component (Ay). The polyester-containing acrylic polyol can be obtained, for example, by reacting a polyester resin having a polymerizable unsaturated group, an alkyl (meth)acrylate ester, a hydroxyl group-containing monomer, and, if necessary, other polymerizable monomers.

A polyester resin having a polymerizable unsaturated group can be obtained by using a polybasic acid and/or a polyhydric alcohol having a polymerizable unsaturated group as part of the polybasic acid and/or polyhydric alcohol when obtaining a polyester resin by condensation reaction of the polybasic acid and the polyhydric alcohol. A polyester resin having a polymerizable unsaturated group can also be obtained by reacting a monomer capable of reacting with a hydroxyl group or a carboxyl group in the polyester resin, specifically maleic acid, (meth)acrylic acid, glycidyl (meth)acrylate, etc., with the polyester resin.

The hydroxyl value of the above component (A) is preferably 1 to 1000 mgKOH/g (more preferably 3 to 900 mgKOH/g). By including such component (A), the effects of the present invention can be fully achieved. The hydroxyl value referred to here is the value expressed in mg of potassium hydroxide equivalent to the moles of hydroxyl groups contained in 1 g of solids (KOH mg/g). In addition, in the present invention, "α to β" is synonymous with "α or more and β or less".

The polyisocyanate component (B) (hereinafter also referred to as "component (B)") in the coating material of the present invention is a component that undergoes a curing reaction with the above-mentioned component (A). In the present invention, this curing reaction produces sufficient effects in terms of adhesion, prevention of plasticizer migration, etc.

Component (B) may be, for example, toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (pure-MDI), polymeric MDI, xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), hydrogenated XDI, hydrogenated MDI, or derivatives thereof which have been allophanated, biurated, dimerized (uretidione), trimerized (isocyanurated), adducted, or carbodiimided; or blocked isocyanates which have been blocked with alcohols, phenols, ε-caprolactam, oximes, active methylene compounds, or the like. One or more of the above may be used.

In the present invention, it is preferable that component (B) contains hexamethylene diisocyanate (HMDI) and/or its derivatives (hereinafter also referred to as "HMDIs"). The content of the above HMDIs is preferably 90% by weight or more (more preferably 95% by weight or more) based on the total amount (solid content) of component (B). Also suitable is an embodiment in which component (B) consists only of HMDIs. Furthermore, a biuret body is suitable as the derivative. In such a case, the formed coating has excellent curing properties, and adhesion, prevention of plasticizer migration, etc. can be improved.

The NCO content of component (B) is preferably 10 to 35% by weight (more preferably 13 to 32% by weight, and even more preferably 15 to 30% by weight). In such a case, adhesion can be improved. The NCO content refers to the weight percentage of NCO contained in component (B).

The mixing of the above components (A) and (B) is preferably carried out in such a ratio that the NCO/OH equivalent ratio of components (A) and (B) is 0.6 to 3.5 (more preferably 1 to 3.0, and even more preferably 1.1 to 2.5). In such a case, the curing properties are excellent, and the effects of the present invention can be fully exerted.

In the present invention, a curing catalyst that promotes the reaction between the (A) component and the (B) component can be used in combination. A curing catalyst is a substance that promotes the reaction and curing of isocyanate groups. Examples of the curing catalyst include amine catalysts, organometallic catalysts, and inorganic catalysts. For example, amine catalysts include ethylenediamine, triethylenediamine, triethylamine, ethanolamine, diethanolamine, and hexamethylenediamine, or their derivatives or mixtures with solvents. Examples of organometallic catalysts include organometallic compounds such as dibutyltin dilaurate and dibutyltin diacetate; and organometallic salts such as potassium acetate, zinc stearate, calcium stearate, lead stearate, aluminum stearate, and tin octylate. Examples of inorganic catalysts include tin chloride. These can be used alone or in combination, and can also be used in a mixture with a solvent. In the present invention, it is particularly preferable to include an organometallic catalyst. In this case, curing is accelerated and sufficient effects are achieved from the early stages of film formation in terms of adhesion, prevention of plasticizer migration, etc.

In addition to the above-mentioned components, various other components can be blended into the coating material of the present invention, provided that the effects of the present invention are not significantly impaired. Examples of such components include color pigments, extender pigments, flame retardants, foaming agents, carbonizing agents, thickeners, plasticizers, preservatives, antifungal agents, anti-algae agents, defoamers, leveling agents, pigment dispersants, antiskinning agents, driers, matting agents, UV absorbers, light stabilizers, antioxidants, anti-pollution agents, catalysts, etc.

In the present invention, such a coating material (first coating material and second coating material) is applied (painted) to the substrate to form a coating. In the present invention, it is preferable to apply the first coating material to the substrate, dry the coating (first coating), and then apply the second coating material. The substrate constitutes the surface of a building, a civil engineering structure, etc. Specifically, it can be applied to various substrates such as walls, pillars, floors, beams, roofs, stairs, ceilings, and doors. Applicable substrates include, for example, concrete, mortar, siding boards, extruded boards, gypsum boards, perlite boards, bricks, plastics, wood, metals, steel frames (steel materials), glass, and porcelain tiles. These substrates may have a coating already formed on their surfaces, may have been subjected to some kind of undercoating treatment (rust prevention treatment, fire retardant treatment, etc.), or may have wallpaper attached to them.

The second coating material can be applied directly to the first coating, or can be applied via some other layer (e.g., a primer layer, an intermediate coating layer, etc.). In the present invention, it is preferable to apply it directly to the first coating. This makes it possible to obtain sufficient effects in terms of preventing plasticizer migration and adhesion. Such a second coating material is effective as a coating material for preventing plasticizer migration.

Next, the characteristics of the first coating material and the second coating material will be described.
The first coating material and the second coating material contain the polyol component (A) as a resin component. Furthermore, in the present invention, the second coating material is characterized in that it contains a polyol (A2) having a larger hydroxyl value than the polyol component (A1) of the first coating material. That is, the first coating material contains a polyol component (A1) having a relatively small hydroxyl value, and the second coating material contains a polyol component (A2) having a relatively large hydroxyl value. In the present invention, by using the first coating material and the second coating material of such an embodiment, it is possible to obtain excellent plasticizer migration prevention properties and sufficient adhesion.

In the present invention, the difference in hydroxyl value between the polyol component (A1) and the polyol component (A2) is preferably 5 mgKOH/g or more (more preferably 10 mgKOH/g or more, even more preferably 50 mgKOH/g or more, particularly preferably 100 mgKOH/g or more, and most preferably 150 mgKOH/g or more). In such a case, excellent plasticizer migration prevention properties can be exhibited. Specifically, the hydroxyl value of the polyol component (A1) is preferably 1 to 200 mgKOH/g (more preferably 3 to 150 mgKOH/g). In addition, the hydroxyl value of the polyol component (A2) is preferably 30 to 1000 mgKOH/g (more preferably 35 to 900 mgKOH/g). In addition, when either or both of the first coating material and the second coating material contain multiple polyol components, at least one polyol component (A1) of the first coating material and at least one polyol component (A2) of the second coating material need only satisfy the above conditions.

Furthermore, the first and second coating materials preferably contain polyether polyol (Ax) as the polyol component (A), and the second coating material preferably contains polyether polyol (Ax2) having a hydroxyl value greater than that of the polyether polyol (Ax1) of the first coating material. Specifically, the hydroxyl value of the polyether polyol component (Ax1) contained in the first coating material is preferably 1 to 200 mgKOH/g (more preferably 3 to 180 mgKOH/g, even more preferably 5 to 150 mgKOH/g, particularly preferably 8 to 100 mgKOH/g, and most preferably 10 to 35 mgKOH/g). The hydroxyl value of the polyether polyol (Ax2) contained in the second coating material is preferably 50 mgKOH/g or more (more preferably 100 mgKOH/g or more, even more preferably 150 mgKOH/g or more, particularly preferably 200 mgKOH/g or more, and most preferably 250 mgKOH/g or more). The upper limit is not particularly limited, but is preferably 1000 mg KOH/g or less (more preferably 800 mg KOH/g or less). In such a case, the effect of the present invention can be further enhanced.

Furthermore, it is preferable that the second coating material contains a polyether polyol (Ax2) having a smaller molecular weight than the polyether polyol (Ax1) of the first coating material. That is, it is preferable that the first coating material contains a polyether polyol (Ax1) having a relatively large molecular weight, and the second coating material contains a polyether polyol (Ax2) having a relatively small molecular weight. This can further improve the plasticizer migration prevention and adhesion.

The difference in molecular weight between the polyether polyol (Ax1) and the polyether polyol (Ax2) is preferably 2000 or more (more preferably 3000 or more, even more preferably 4000 or more, particularly preferably 6000 or more, and most preferably 6500 or more). In such a case, excellent plasticizer migration prevention properties can be exhibited. Specifically, the molecular weight of the polyether polyol (Ax1) is preferably 1000 or more (more preferably 3000 or more, even more preferably 5000 or more, particularly preferably 6000 or more, and most preferably 6500 or more), and the upper limit is preferably 18000 or less (more preferably 15000 or less, and even more preferably 12000 or less). The molecular weight of the polyether polyol (Ax2) is preferably 4000 or less (more preferably 2000 or less, even more preferably 1000 or less, particularly preferably 900 or less, and most preferably 600 or less), and the lower limit is preferably 50 or more (more preferably 100 or more, and even more preferably 150 or more). By using such an (Ax2) component, it is possible to improve the plasticizer migration prevention property. In the present invention, the molecular weight of the polyol component is the number average molecular weight (Mn), which is the so-called polystyrene equivalent molecular weight determined by gel permeation chromatography using a polystyrene polymer as a reference.

When either or both of the first and second coating materials contain multiple polyether polyols (Ax), it is sufficient that at least one polyether polyol component (Ax1) of the first coating material and at least one polyether polyol component (Ax2) of the second coating material satisfy the above conditions, and it is more preferable that all polyether polyols (Ax2) of the second coating material satisfy the above conditions for all polyether polyols (Ax1) of the first coating material.

In the first coating material, the solid content of the polyether polyol (Ax1) in the solid content of the component (A1) is preferably 50% by weight or more (more preferably 80% by weight or more, and even more preferably 90% by weight or more). There is no particular upper limit, and the component (A1) may be only the polyether polyol (Ax1). In such a case, the effects of the present invention can be fully exerted.

On the other hand, the second coating material preferably further contains an acrylic polyol (Ay2) as the polyol component (A2). In this case, the hydroxyl value of the acrylic polyol (Ay2) is preferably 1 to 200 KOHmg/g (more preferably 3 to 100 KOHmg/g, and even more preferably 5 to 80 KOHmg/g). If the hydroxyl value of the acrylic polyol (Ay2) is within such a range, it has excellent plasticizer migration prevention properties and is also advantageous in terms of improving adhesion. In addition, the weight ratio (solid content) of the polyether polyol (Ax2) to the acrylic polyol (Ay2) is preferably 90:10 to 10:90 (more preferably 80:20 to 20:80, and even more preferably 70:30 to 50:50). In such a case, it has excellent plasticizer migration prevention properties and is also advantageous in terms of improving adhesion.

In addition, in the present invention, the solid content (total) of the polyether polyol (Ax2) and the acrylic polyol (Ay2) in the solid content of the (A2) component is preferably 50% by weight or more (more preferably 80% by weight or more, and even more preferably 90% by weight or more). There is no particular upper limit, and the (A2) component may be only the polyether polyol (Ax2) and the acrylic polyol (Ay2). In such a case, the effects of the present invention can be fully exerted.

The first coating material of the present invention contains a plasticizer as an essential component in addition to the above resin component. Such a first coating material is not particularly limited as long as it is a material that contains a plasticizer in the above resin component, but examples include coating materials, sheets, sealing materials, plastisols, etc., which may have various functionalities (e.g., waterproofness, flame retardancy, heat resistance, etc.).

The plasticizer is not particularly limited, but examples thereof include phthalate ester compounds such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dihexyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, and butyl benzyl phthalate; diethyl adipate, dibutyl adipate, diisobutyl adipate, dihexyl adipate, di-2-ethylhexyl adipate, dioctyl adipate, diisononyl adipate, and diisodecyl adipate; Aliphatic dibasic acid ester compounds such as bis(butyl diglycol) adipate, diethyl sebacate, dibutyl sebacate, dihexyl sebacate, and di-2-ethylhexyl sebacate; adipic acid polyester compounds such as 1,3-butylene glycol adipate polyester and 1,2-propylene glycol adipate polyester; maleic acid ester compounds such as dimethyl maleate, diethyl maleate, dibutyl maleate, dihexyl maleate, di-2-ethylhexyl maleate, diisononyl maleate, and diisodecyl maleate;

Phosphate ester compounds such as triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and 2-ethylhexyl diphenyl phosphate; trimellitate compounds such as tris-2-ethylhexyl trimellitate; ricinoleate compounds such as methyl acetyl risinoleate; epoxy ester compounds such as di-2-ethylhexyl epoxyhexahydrophthalate, diepoxystearyl epoxyhexahydrophthalate, epoxidized fatty acid butyl, epoxidized fatty acid 2-ethylhexyl, epoxidized soybean oil, and epoxidized linseed oil; benzoic acid ester compounds such as benzoic acid glycol ester; chlorinated paraffins; aromatic hydrocarbon compounds such as 1-phenyl-1-xylylethane and 1-phenyl-1-ethylphenylethane; lactones such as γ-butyrolactone; and mixtures of petroleum resins (polymers of aromatic hydrocarbon fractions having 8 to 10 carbon atoms) and styrylxylene. These may contain one or more types.

In the present invention, it is preferable that the first coating material contains one or more selected from a phthalate ester compound, an aliphatic dibasic acid ester compound, a phosphate ester compound, and a chlorinated paraffin. In this case, the effects of the present invention can be fully exhibited. In addition, in the present invention, even if a relatively low molecular weight plasticizer having a molecular weight of 1000 or less (preferably 100 to 800) is contained, the effects of the present invention can be fully exhibited. Note that the molecular weight of the plasticizer is a value calculated from the molecular formula.

The content of the plasticizer in the first coating material is preferably 5 to 200 parts by weight (more preferably 10 to 150 parts by weight) per 100 parts by weight of the total solid content of the polyol component (A1) and the polyisocyanate component (B1) (hereinafter also referred to as the "resin component (solid content)"). Thus, even when a relatively large amount of plasticizer is contained, the coating method of the present invention can provide sufficient effects in terms of preventing plasticizer migration and adhesion.

Furthermore, the first coating material may contain functional powders for imparting various functionalities. Examples of the functional powders that can be used include powders that impart heat insulation, heat resistance, ultraviolet shielding, and infrared shielding, which exhibit the desired functions. By including such functional powders, the coating can be given the desired performance. Examples of such functional powders include powders that impart heat insulation, heat resistance, and ultraviolet shielding. These can be used alone or in combination of two or more types.

The first coating material of the present invention preferably contains a heat resistance-imparting powder as a functionality-imparting powder. Such a first coating material is suitable as a foamable fire-resistant coating material to be applied to the surface coating of structures such as buildings and civil engineering structures. The heat resistance-imparting powder may be any powder that exhibits at least one of the following effects at high temperatures: dehydration and cooling effect, non-flammable gas generation effect, binder carbonization promotion effect, carbonized insulation layer formation effect, etc., and has the effect of suppressing combustion, and examples of such powder include foaming agents, carbonizing agents, and flame retardants.

Specific examples of foaming agents include melamine and its derivatives, dicyandiamide and its derivatives, azobistetrazole and its derivatives, azodicarbonamide, urea, and thiourea. These can be used alone or in combination of two or more. The content of the foaming agent is preferably 10 to 200 parts by weight (more preferably 20 to 150 parts by weight) per 00 parts by weight of the resin component (solid content). The foaming agent of the present invention imparts a foaming action to the coating due to a temperature rise during a fire or the like, and specifically, imparts a foaming action when the temperature of the coating surface is preferably 200°C or higher.

Examples of carbonizing agents include pentaerythritol, dipentaerythritol, trimethylolpropane, starch, and casein. These can be used alone or in combination of two or more. In the present invention, pentaerythritol and dipentaerythritol are particularly preferred because they have excellent dehydration and cooling effects and the ability to form a carbonized insulation layer. The content of the carbonizing agent is preferably 10 to 200 parts by weight (more preferably 20 to 120 parts by weight) per 100 parts by weight of the resin component (solid content). The carbonizing agent of the present invention imparts the ability to form a carbonized insulation layer by carbonizing the resin component and dehydrating and carbonizing it due to a temperature rise during a fire, etc.

The flame retardant may be, for example, an organic phosphorus compound such as tricresyl phosphate or diphenyl cresyl phosphate; a chlorine compound such as chlorinated polyphenyl, chlorinated polyethylene, diphenyl chloride, triphenyl chloride, chlorinated paraffin, pentachlorinated fatty acid ester, perchloropentacyclodecane, chlorinated naphthalene, or tetrachlorophthalic anhydride; an antimony compound such as antimony trioxide or antimony pentachloride; a phosphorus compound such as phosphorus trichloride, phosphorus pentachloride, ammonium phosphate, ammonium polyphosphate, melamine phosphate, melam polyphosphate, boron phosphate, boron polyphosphate, aluminum phosphate, or aluminum polyphosphate; or an inorganic compound such as zinc borate or sodium borate. These may be used alone or in combination of two or more. The content of the flame retardant is preferably 100 to 1,000 parts by weight (more preferably 200 to 800 parts by weight) per 100 parts by weight of the resin component (solid content).

Furthermore, the first coating material may contain fillers, fibers, etc. Examples of fillers include talc, calcium carbonate, sodium carbonate, aluminum oxide (alumina), titanium oxide, zinc oxide, silica, clay, clay, siliceous silica, mica, silica sand, silica powder, quartz powder, barium sulfate, aluminum hydroxide, magnesium hydroxide, etc. These may be used alone or in combination of two or more. Examples of fibers include organic fibers such as acrylic fibers, acetate fibers, aramid fibers, cuprammonium fibers (cupra), nylon fibers, novoloid fibers, pulp fibers, viscose rayon, vinylidene fibers, polyester fibers, polyethylene fibers, polyvinyl chloride fibers, polychral fibers, boronosic fibers, polypropylene fibers, and cellulose fibers, and inorganic fibers such as carbon fibers, rock wool fibers, glass fibers, silica fibers, alumina fibers, silica-alumina fibers, slag wool fibers, ceramic fibers, carbon fibers, and silicon carbide fibers. These may be used alone or in combination of two or more.

The second coating material of the present invention preferably contains, in addition to the resin component, a powder component such as a color pigment or an extender pigment. This enhances the cohesive force during coating formation, and provides better adhesion and other effects. To achieve such effects, it is desirable to use an embodiment in which the powder component is contained in an amount of 1 to 200 parts by weight (preferably 5 to 150 parts by weight) per 100 parts by weight of the total solid content of the polyol component (A2) and the polyisocyanate component (B2). Examples of color pigments include titanium oxide, zinc oxide, carbon black, graphite, black iron oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, copper-magnesium composite oxide, bismuth-manganese composite oxide, red iron oxide, molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, fast yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine blue, Prussian blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigments, and pearl pigments. These can be used alone or in combination of two or more. Examples of extender pigments include heavy calcium carbonate, clay, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon, and diatomaceous earth.

The coating material of the present invention can be applied by mixing the base agent containing the polyol component (A) and the hardener containing the polyisocyanate component (B) immediately before painting. The solvent can be contained in either the base agent or the hardener, or in both. In addition, in the present invention, a solvent can be mixed as a diluent at the time of painting, separate from the base agent and the hardener. In particular, it is desirable that the solvent of the second coating material is contained in an amount of 5 to 500 parts by weight (preferably 10 to 400 parts by weight, more preferably 20 to 300 parts by weight) per 100 parts by weight of the total solid content of the (A) component and the (B) component. If the content of the solvent is within this range, it is preferable in terms of preventing plasticizer migration, the finish of the topcoat material, and the like. In particular, it is desirable that the solid content of the coating material of the present invention after dilution is 25 to 90% by weight (more preferably 30 to 85% by weight). If it is within this range, the above-mentioned effects can be further enhanced.

The coating material of the present invention can be applied by various methods, such as brush coating, roller coating, spray coating, etc. The amount of coating and the number of coats of the first coating material when applied may be set according to the functionality of each coating material. The amount of coating of the first coating material when applied is preferably 0.5 to 5.0 kg/m ² (more preferably 0.8 to 3.0 kg/m ² ). The number of coats of the first coating material is preferably 1 to 2.
On the other hand, the amount of the second coating material applied is preferably 30 to 500 g/m ² (more preferably 50 to 300 g/m ² ). The number of coats of the second coating material may be appropriately determined depending on the surface condition of the film formed by the first coating material, and is preferably 1 to 2 coats. The coating material of the present invention can sufficiently exhibit plasticizer migration prevention properties even when applied once.

In the present invention, in order to protect the coating formed by the above-mentioned coating materials (first coating material and second coating material), a topcoat material can be applied as necessary. Such a topcoat material can be formed by applying a known topcoat material. As the topcoat material, for example, any of clear or colored types, glossy or matte types, hard or elastic types, thin or thick film types, etc. can be used. In addition, either water-based or solvent-based may be used, and can be appropriately selected according to the desired purpose.

The topcoat material of the present invention preferably contains a resin component. Examples of the form of such resin include solvent-soluble resin, non-aqueous dispersion resin, solventless resin, water-dispersed resin, water-soluble resin, etc. Examples of the type of resin include acrylic resin, urethane resin, epoxy resin, vinyl chloride resin, vinyl acetate resin, acrylic silicone resin, fluororesin, silicon resin, polyvinyl alcohol, cellulose derivatives, etc., or composites thereof. These can be used alone or in combination of two or more. In the present invention, it is particularly preferable to include one or more types selected from urethane resin, epoxy resin, acrylic resin, acrylic silicone resin, and fluororesin.

Furthermore, the resin component may have crosslinking reactivity. When the resin component is a crosslinking reaction type resin, the water resistance, durability, and adhesion of the formed coating are improved, and the occurrence of swelling and peeling of the coating due to rainfall, condensation, etc. can be suppressed. Furthermore, when the first coating material contains a functional powder, various functionalities (for example, heat resistance, etc.) can be stably maintained. Such a crosslinking reaction type resin may be either one that causes a crosslinking reaction by itself or one that causes a crosslinking reaction by a crosslinking agent that is mixed separately. Such crosslinking reactivity can be imparted by combining reactive functional groups such as, for example, a hydroxyl group and an isocyanate group, a carbonyl group and a hydrazide group, an epoxy group and an amino group, an aldo group and a semicarbazide group, a keto group and a semicarbazide group, alkoxyl groups, a carboxyl group and a metal ion, a carboxyl group and a carbodiimide group, a carboxyl group and an epoxy group, a carboxyl group and an aziridine group, or a carboxyl group and an oxazoline group. Among these, it is preferable to use a crosslinking reactive resin that generates one or more crosslinking reactions selected from the group consisting of a hydroxyl group and an isocyanate group, a carbonyl group and a hydrazide group, and an epoxy group and an amino group.

As components other than the resin component of the above-mentioned topcoat material, for example, color pigments, extender pigments, aggregates, etc. can be mixed. By appropriately mixing such components, it is possible to express the desired color and texture. There are no particular restrictions on the amount of color pigments, extender pigments, aggregates, etc. mixed, so long as it does not impair the effect of the above-mentioned coating material, but it is preferably 1 to 2000 parts by weight (more preferably 5 to 1000 parts by weight) per 100 parts by weight of the solid content of the resin component.

In the present invention, it is particularly preferable to use pigments that are infrared reflective and/or infrared transparent as the color pigments and extender pigments. This can further increase the durability of the formed coating.

Examples of pigments that are infrared reflective include aluminum flakes, titanium oxide, barium sulfate, zinc oxide, iron oxide, calcium carbonate, silicon oxide, magnesium oxide, zirconium oxide, yttrium oxide, indium oxide, alumina, iron-chromium composite oxide, manganese-bismuth composite oxide, manganese-yttrium composite oxide, black iron oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, etc., and one or more of these can be used.

Examples of pigments that are infrared transparent include perylene pigments, azo pigments, yellow lead, titanium red, cadmium red, quinacridone red, isoindolinone, benzimidazolone, phthalocyanine green, phthalocyanine blue, cobalt blue, indanthrene blue, ultramarine, and Prussian blue, and one or more of these can be used.

Furthermore, the topcoat material can also contain various additives that can be used in regular paints. Examples of such additives include thickeners, film-forming agents, leveling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, preservatives, antifungal agents, anti-algae agents, antibacterial agents, dispersants, defoamers, adsorbents, UV absorbers, light stabilizers, antioxidants, fibers, anti-pollution agents, hydrophilic agents, water repellents, coupling agents, catalysts, etc.

The topcoat material may be applied by a known application method, for example, by using various methods such as brush coating, roller coating, and spray coating. The amount of coating is preferably 30 to 5000 g/m ² (more preferably 50 to 3000 g/m ² ). The number of coats of the topcoat material may be set appropriately, but is preferably 1 to 2 times. In addition, drying may be preferably performed at room temperature.

According to the present invention, a laminate having a first coating formed from the above-mentioned first coating material and a second coating formed from the above-mentioned second coating material is obtained. The laminate of the present invention is excellent in preventing migration of plasticizers and can exhibit excellent adhesion. Furthermore, the laminate of the present invention has a topcoat layer formed from a topcoat material on the second coating, and thus is excellent in preventing migration of plasticizers and exhibits excellent adhesion, as well as improved aesthetics and weather resistance.

The following examples will clarify the features of the present invention. However, the present invention is not limited to these examples.

<Coating material>
(Main ingredients 1 to 15)
According to the formulation shown in Table 1, component (A), color pigment, curing catalyst, and additives were mixed in a conventional manner to prepare a base resin.
The following raw materials were used:

Polyol (A)
Polyether polyol (Ax)
(Ax-1) Polyether polyol (hydroxyl value 17 mg KOH/g, number of functional groups 3, number average molecular weight 10,000, solid content 100% by weight)
(Ax-2) Polyether polyol (hydroxyl value 24 mg KOH/g, number of functional groups 3, number average molecular weight 7000, solid content 100% by weight)
(Ax-3) Polyether polyol (hydroxyl value 55 mg KOH/g, number of functional groups 3, number average molecular weight 3000, solid content 100% by weight)
(Ax-4) Polyether polyol (hydroxyl value 160 mg KOH/g, number of functional groups 3, number average molecular weight 1000, solid content 100% by weight)
(Ax-5) Polyether polyol (hydroxyl value 230 mg KOH/g, number of functional groups 3, number average molecular weight 700, solid content 100% by weight)
(Ax-6) Polyether polyol (hydroxyl value 400 mg KOH/g, number of functional groups 3, number average molecular weight 400, solid content 100% by weight)
Acrylic polyol (Ay)
(Ay-1) Acrylic polyol (hydroxyl value 40 KOHmg/g, solid content 50% by weight, medium: aromatic hydrocarbon compound, ester compound)
(Ay-2) Polyester-containing acrylic polyol (hydroxyl value 40 KOH mg/g, polyester ratio 10 wt%, solid content 50 wt%, medium: aromatic hydrocarbon compound, ester compound)
The component (A) is a liquid at 20°C.

Plasticizer 1: Diisononyl phthalate (molecular weight 419)
Plasticizer 2: Diisononyl adipate (molecular weight 399)
・Functional powder: flame retardant, foaming agent, carbonizing agent, etc. ・Coloring pigment: titanium oxide, average particle size 0.3 μm
・Curing catalyst: organometallic catalyst ・Additive 1: dispersant, defoamer, etc. ・Additive 2: Dilution solvent (aromatic hydrocarbon)

(Curing agent 1)
A curing agent was prepared by mixing 80 parts by weight of polyisocyanate (B) (biuret type hexamethylene diisocyanate, NCO content 23.5%) and 20 parts by weight of a dilution solvent (aromatic hydrocarbon).

(Preparation of Coating Material)
The base materials 1 to 15 shown in Table 1 and the curing agent were mixed so that the NCO/OH equivalent ratio of the polyol component and the polyisocyanate component was 1.2, to obtain coating materials 1 to 15.

<Topcoat material>
Acrylic polyol (hydroxyl value 20 KOHmg/g, solid content 50% by weight, medium: aliphatic hydrocarbon compound) 100 parts by weight, titanium dioxide 40 parts by weight, additives (thickener, defoamer) 10 parts by weight were uniformly mixed and stirred in a conventional manner to prepare the base material. Next, polyisocyanate (adduct type hexamethylene diisocyanate, NCO content 12%) 50 parts by weight, dilution solvent (aliphatic hydrocarbon) 50 parts by weight were mixed to prepare the hardener. The base material and the hardener were mixed so that the NCO/OH equivalent ratio of the polyol component and the polyisocyanate component was 1.0, respectively, to prepare the topcoat material.

(Examples 1 to 12, Comparative Examples 1 to 3)
The following evaluations were carried out for each coating material. The results are shown in Table 2.

- Preparation of test specimen [I] The first coating material was sprayed onto a 150 mm x 70 mm steel plate at 1.5 kg/ ^m2 and cured for 7 days. Next, the second coating material was brushed onto the plate at a coating amount of 100 g/ ^m2 and cured for 24 hours to prepare test specimen [I]. The combination of the first coating material and the second coating material is shown in Table 2. All painting and curing were performed under standard conditions (temperature 23°C, relative humidity 50%).
<Evaluation of Plasticizer Migration Prevention Property>
The prepared specimen [I] was left in an incubator at 50° C. or 80° C. for one week. The specimen was taken out of the incubator, placed horizontally, and black silica sand was sprinkled on it. The specimen was then immediately stood upright and the black silica sand was allowed to fall naturally. The extent of the attached black silica sand was visually confirmed to evaluate the plasticizer migration prevention property.
The evaluation was done on a four-level scale (A>B>C>D), with "A" being a rating for samples with almost no black silica sand adhering and "D" being a rating for samples with significant black silica sand adhering.

<Adhesion Evaluation 1>
The prepared specimen [I] was evaluated for adhesion to the surface of the plasticizer-containing material by the cross-cut tape method in accordance with JIS K 5600-5-6. The evaluation criteria were as follows:
A: The area of the defective portion is less than 10%. B: The area of the defective portion is 10% or more and less than 25%. C: The area of the defective portion is 25% or more and less than 50%. D: The area of the defective portion is 50% or more.

In Examples 1 to 12, good plasticizer migration prevention properties were obtained, and a coating with good adhesion was formed. In particular, in Examples 6 to 11, excellent plasticizer migration prevention properties were exhibited, and furthermore, in Examples 5 to 11, a coating with excellent adhesion was formed.

Next, the following evaluations were carried out for Examples 6 to 11. The results are shown in Table 2.
Preparation of specimen [II] The first coating material was sprayed onto a 150 mm x 70 mm steel plate at 1.5 kg/ ^m2 and cured for 7 days. Next, the second coating material was brushed onto the steel plate at a coating amount of 100 g/ ^m2 and cured for 24 hours. The combination of the first coating material and the second coating material is shown in Table 2.
Next, the topcoat material was spray-painted at a coating amount of 0.3 kg/ ^m2 and cured for 72 hours to prepare a test specimen. Note that painting, curing, etc. were all performed under standard conditions (temperature 23 ° C., relative humidity 50%).

<Adhesion Evaluation 2>
The prepared specimen [II] was evaluated for adhesion to the coating material and topcoat material by the cross-cut tape method according to JIS K 5600-5-6. The evaluation criteria were the same as those in Adhesion Evaluation 1 above.

<Heat resistance protection evaluation>
The prepared specimen [II] was left in an incubator at 80°C for one week, and then the resulting specimen was subjected to radiant heat of 50 kW/m2 for 15 minutes on the surface of the specimen using an electric heater (CONEIII, manufactured by Toyo Seiki Co., Ltd.) according to ISO 5660-1 cone calorimeter method, and the expansion ratio and the steel plate backside temperature were measured. The evaluation criteria are as follows. The results are shown in Table 2.
(Expansion Ratio)
AA: Expansion ratio over 35 times A: Expansion ratio over 25 times and less than 35 times B: Expansion ratio over 20 times and less than 25 times C: Expansion ratio over 15 times and less than 20 times D: Expansion ratio less than 15 times (reverse surface temperature)
AA: Less than 430°C A: 430°C or more and less than 470°C B: 470°C or more and less than 500°C C: 500°C or more and less than 550°C D: 550°C or more

In Examples 6 to 11, a carbonized heat insulating layer was formed with excellent foaming properties, and heat-resistant protection of the substrate was obtained.

Claims (4)

A coating forming method for applying a first coating material and a second coating material, the first coating material containing a plasticizer, the first coating material and the second coating material containing a polyol component (A) and a polyisocyanate component (B) as resin components,
the first coating material and the second coating material each contain a polyether polyol (Ax) as the polyol component (A), and the second coating material contains a polyether polyol (Ax2) having a hydroxyl value larger than the polyether polyol (Ax1) of the first coating material . 2. The method for forming a coating film according to claim 1, wherein the polyether polyol (Ax2) contains a polyether polyol having a hydroxyl value of 50 mg KOH/g or more. A laminate having a first coating formed of a first coating material and a second coating formed of a second coating material,
The first coating material contains a plasticizer, and the first coating material and the second coating material contain a polyol component (A) and a polyisocyanate component (B) as resin components,
the first coating material and the second coating material each contain a polyether polyol (Ax) as the polyol component (A), and the second coating material contains a polyether polyol (Ax2) having a hydroxyl value larger than the polyether polyol (Ax1) of the first coating material . The laminate according to claim 3, wherein the polyether polyol (Ax2) contains a polyether polyol having a hydroxyl value of 50 mg KOH/g or more.