KR20200018979A - Coating kit for smc materials - Google Patents

Abstract

The present invention relates to a paint kit for a sheet molding compound (SMC) material and, more specifically, to a paint kit for an SMC material, comprising a primer paint composition including: a resin containing 3 to 25 parts by weight of an alkyd resin, 5 to 35 parts by weight of a first polyester polyol resin, 5 to 30 parts by weight of a pigment and 40 to 70 parts by weight of a first solvent; and a curing agent part.

Description

Paint kit for SMC material {COATING KIT FOR SMC MATERIALS}

The present invention relates to a paint kit, and more particularly, to a paint kit suitable for forming a multilayer coating on a sheet molding compound (SMC) material.

Recently, in order to reduce the weight of automobile interior or exterior parts, a lightweight alloy mixed with various minerals such as aluminum and magnesium is applied to existing steel materials, or a thin and light plastic composite material having the same or higher strength as the existing steel materials. The scope of application is gradually expanding.

Among them, the development of various plastic composite materials is attracting attention, and in the automobile material industry, polypropylene (PP) material, sheet molding compound (SMC) material, nylon material, carbon fiber reinforced plastics (CFRP) The material attracts attention. In particular, SMC material, which is a composite sheet in the form of a sheet, is not only similar to a steel material, but also has a stiffness and strength characteristics as well as a metallic feel, and can be processed through a conventional electrodeposition process. The ability to withstand topcoat bake temperatures that can be used in the original equipment manufacturer process has the advantage that they can be easily processed on assembly lines that handle steel.

By the way, in the case of such SMC material, there is a problem that the adhesion or workability of the existing paints to this poor, limiting the utilization of the SMC material.

Korean Unexamined Patent Publication No. 2005-0063972

An object of the present invention, while showing excellent adhesion and workability to the SMC material, the coating film formed by using the coating material for SMC material excellent in the physical properties, such as water resistance, weather resistance, hardness, chemical resistance and the like, and using the same, It is to provide a multilayer coating film formed by.

In order to achieve the above object, one aspect of the present invention includes 3 to 25 parts by weight of alkyd resin, 5 to 35 parts by weight of the first polyester polyol resin, 5 to 30 parts by weight of the pigment and 40 to 70 parts by weight of the first solvent. Resin portion to be; It provides a paint kit for a sheet molding compound (SMC) material comprising a primer coating composition comprising a;

The paint kit may include a resin part including 15 to 45 parts by weight of the first acrylic polyol resin, 15 to 40 parts by weight of the second polyester polyol resin, 0.5 to 10 parts by weight of the pigment, and 10 to 45 parts by weight of the second solvent; And a curing agent portion; may further include a base coat coating composition comprising a.

The paint kit may include a resin part including 55 to 80 parts by weight of the second acrylic polyol resin, 1 to 20 parts by weight of the third polyester polyol resin, and 2 to 30 parts by weight of the third solvent; And a curing agent portion; may further comprise a clear coat coating composition comprising a.

The paint kit of the present invention is coated with excellent adhesion and workability to the SMC material, the formed coating film shows excellent effects not only durability, such as water resistance, impact resistance, weather resistance, hardness, chemical resistance, but also appearance quality, SMC material is used a lot It can be usefully used to coat the surface of the automotive parts.

Hereinafter, the present invention will be described in detail.

The present invention provides a paint kit for a sheet molding compound (SMC) material.

The paint kit for the SMC material of the present invention basically comprises a primer paint composition. In addition, the paint kit for the SMC material of the present invention may further include a base coat paint composition or a clear coat paint composition. Referring to the paint kit for SMC material of the present invention in detail.

<Primer coating composition>

The primer coating composition included in the paint kit for SMC material of the present invention is coated on a substrate made of SMC material to improve the adhesion between the layer and the substrate further formed thereon, and to improve the physical properties of the finally formed coating film For the purpose, it may be a two-part coating composition comprising a resin portion and a curing agent portion.

The resin portion of the primer coating composition may include an alkyd resin, a first polyester polyol resin, a pigment, and a first solvent.

Alkyd resin

The alkyd resin is a component for improving the workability of the primer coating composition and the surface properties of the coating film (primer layer) formed from the primer coating composition.

The alkyd resin is a polyester resin (oil free alkyd resin) obtained by condensation reaction of a polycarboxylic acid and a polyol containing a long-chain aliphatic polycarboxylic acid, or a polyester resin (oil) obtained by using an oil component such as an oil or fat or a fatty acid. Modified alkyd resin).

The polycarboxylic acid used to prepare the alkyd resin is a conventional polycarboxylic acid used for preparing polyester, for example, aromatic dicarboxylic acid or anhydrides thereof (terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, etc.). , Alicyclic dicarboxylic acid or its anhydride (tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, methyltetrahydrophthalic acid, etc.), aliphatic dicarboxylic acid or its anhydride (succinic acid, succinic anhydride, C _4-20 alkanedicarboxylic acid such as adipic acid, azeline acid, sebacic acid, itaconic acid, itaconic anhydride, maleic acid, unsaturated dicarboxylic acid such as maleic anhydride, fumaric acid, fumaric anhydride, etc.) To tetraalic acid of trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, methylcyclohexericarboxylic acid, or carboxylic acid thereof It may be one or mixture of two or more selected from an ester.

The polyols used to prepare the alkyd resins are conventional polyols used in the preparation of polyesters, for example aliphatic diols [alkanediols (ethylene glycol, propylene glycol, trimethylene glycol, diethylene glycol, triethylene glycol, di Propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl -1,3-propanediol, neopentylglycol, 1,6-hexanediol, 2,2-diethyl-1,3-propanediol, 3,3-dimethylolheptane, 2-ethyl-2-butyl-1 C _2-22 alkanediols such as, 3-propanediol, 1,12-dodecanediol, and 1,18-octadecanediol), alkenediols (2-butene-1,4-diol, 2,6-dimethyl- 1-octene-3,8-diol and the like), polyC _2-4 alkylene glycol (polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), and alicyclic diols (1,4-cyclohexanediol, Cycloal, such as 1, 4- cyclohexane dimethanol Hydrogenated, such as a diol, hydrogenated bisphenol A, bisphenols, or a C _2-4 alkylene oxide adduct and the like), aromatic diol (such as resorcinol Rezin benzene diol, an aromatic diol, a bis-hydroxy, such as xylylene glycol Polyester diols such as oxyethylene terephthalate, bisphenols such as bisphenol A, bisphenol S, bisphenol F, or C _2-4 alkylene oxide adducts thereof, and the like or trivalent or higher polyols [aliphatic polyols (glycerine, 1, 2,6-hexanetriol, trimethylolethane, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3- (hydroxymethyl) pentane, Aliphatic C _3-24 triols such as 2,2-bis (hydroxymethyl) -3-butanol, pentaerythritols such as pentaerythritol, dipentaerythritol, and the like; sugar alcohols (D-sorbitol, xylitol, D-mannitol and the like); and the like or a mixture of two or more thereof.

Oil components used to prepare the alkyd resin include fats and oils, saturated fatty acids and unsaturated fatty acids, and fats and oils include, for example, vegetable oils (cotton oil, linseed oil, castor oil, dehydrated castor oil, sapling oil), Soybean oil, rice bran oil, corn oil, sesame oil, sunflower oil, sweet sugar oil, asami oil, rapeseed oil, peanut oil, palm oil, palm oil, kaypok oil, one way oil, olive oil, tall oil, eggplant oil, paulownia oil, etc. Pork, sunny place, goat, marge, gyeji, turkey, etc.), fish oil (herring oil, flounder oil, cod oil, sesame oil, hariba oil, carp oil, trout oil, catfish oil, etc.), or hydrogenated oil thereof It may be one or a mixture of two or more selected from. As the saturated fatty acid, for example, straight chains such as caprylic acid, capric acid, pelagonic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, or the like Branched chain saturated C _8-24 fatty acids and the like can be used, and examples of the unsaturated fatty acids include myristic acid, palmitic acid, petroleic acid, oleic acid, basonic acid, linoleic acid, linolenic acid, eleostearic acid, and gart. Straight or branched chain unsaturated C _8-24 fatty acids such as lenic acid, arachidonic acid and erucic acid can be used. Said saturated or unsaturated fatty acid can be used individually or in combination of 2 or more types.

The alkyd resin may have a solid content of 50 to 80% by weight, for example, 60 to 70% by weight. When the solid content of the alkyd resin is less than 50% by weight, the solids content of the primer coating composition may be lowered, resulting in poor workability during coating, and when the solid content is more than 80% by weight, the viscosity of the alkyd resin may be increased. The production time of the composition is increased, and problems such as poor shelf life may occur.

The alkyd resin may have a hydroxyl value of 130 to 210 mgKOH / g, for example, 133 to 207 mgKOH / g. When the hydroxyl value of the alkyd resin is less than 130 mgKOH / g, the crosslinking density of the coating film may be lowered, and thus physical properties such as water resistance may be lowered. have.

The alkyd resin may have a weight average molecular weight (g / mol) of 9,000 to 17,000, for example 10,000 to 15,000. When the weight average molecular weight (g / mol) of the alkyd resin is less than 9,000, adhesion of the coating film may be reduced, and when the weight average molecular weight (g / mol) is more than 17,000, the salvability of the coating film may be reduced. .

The alkyd resin may have an iodine value of 15 to 28. For example, it may be 18 to 25. If the iodine value of the alkyd resin is less than 15, the adhesion may be inferior, and if it exceeds 28, the hardness and flexibility of the coating may be inferior.

The alkyd resin may be included in an amount of 3 to 25 parts by weight, for example, 5 to 20 parts by weight, or 8 to 15 parts by weight. When the content of the alkyd resin is less than 3 parts by weight, the drying rate of the coating film is lowered, and workability is lowered, and when it is more than 25 parts by weight, physical properties such as weather resistance may be lowered.

First Polyester Polyol Resin

The said 1st polyester polyol resin is a component for improving the external appearance characteristic and surface property of the coating film (primer layer) formed from a primer coating composition.

The first polyester polyol resin may be prepared by condensation reaction of a glycol monomer and a monomer having an acid group. As the glycol monomer, for example, neopentyl glycol, trimethylol propane, diethylene glycol, triethylene glycol, 1,6-hexanediol, 1,4-butanediol, 1,4-cyclohexaneamitanol, and the like may be used. As the monomer having an acid group, for example, terephthalic acid, maleic anhydride, fumaric acid, phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, adipic acid, and the like may be used.

The first polyester polyol resin may be a solid content of 70 to 90% by weight, for example 75 to 85% by weight. If the solid content of the first polyester polyol resin is less than 70% by weight, the solid content of the primer coating composition is lowered, so that it is difficult to form a sufficient coating film thickness, and when the solid content is more than 90% by weight, the coating film is softened to have a pencil hardness. Physical properties such as cannot be satisfied.

The first polyester polyol resin may have a hydroxyl value of 110 to 180 mgKOH / g. When the hydroxyl value of the first polyester polyol resin is less than 110 mgKOH / g, the crosslinking density of the coating film may be lowered, and thus the physical properties such as weather resistance may be lowered. Can be elevated.

The first polyester polyol resin may have a weight average molecular weight (g / mol) of 3,000 to 10,000, for example, 4,000 to 8,000. When the weight average molecular weight (g / mol) of the first polyester polyol resin is less than 3,000, adhesion of the coating film may be reduced, and when the weight average molecular weight (g / mol) exceeds 10,000, Can be degraded.

The first polyester polyol resin may have a glass transition temperature (Tg) of -35 ° C to -5 ° C, for example, -33 ° C to -7 ° C. When the glass transition temperature of the first polyester polyol resin is less than -35 ° C, the hardness of the coating film may be lowered, and when the glass transition temperature is higher than -5 ° C, workability may be reduced.

The first polyester polyol resin may be included in an amount of 5 to 35 parts by weight based on 3 to 25 parts by weight of the alkyd resin, for example, 10 to 30 parts by weight, and more specifically 16 to 25 parts by weight. May be included. If the content of the first polyester polyol resin is less than 5 parts by weight may reduce the appearance properties and physical properties of the coating film, if the content of more than 35 parts by weight increases the curing rate of the coating film may cause a problem of workability deterioration Can be.

In addition, the primer coating composition, it is preferable that the first polyester polyol resin is contained in the same or more content than the content of the alkyd resin. Specifically, the primer coating composition. The first polyester polyol resin and the alkyd resin may be included in a weight ratio of 1: 1 to 5: 1, for example, may be included in a weight ratio of 1: 1 to 3: 1. When the weight ratio of the first polyester polyol resin and the alkyd resin satisfies the above range, the coating film appearance characteristics may be improved, and physical properties such as water resistance and weather resistance may be excellent.

Pigment

Sanding is often necessary due to the characteristics of the SMC material, and the sand marks generated at this time need to be concealed to improve the appearance quality of the finally formed coating film. The pigment is a component for concealing the sand mark generated in the SMC material as described above.

The pigment may be red, yellow, orange, blue, green, black, white, pearl and metallic, but is not limited thereto. For example, barium sulfate (Ba ₂ SO ₄ ), barite, calcium carbonate (CaCO ₃ ), clay (clay, Al ₂ O ₃ · 2SiO ₂ · 2H ₂ O), bone powder (3MgO 4SiO ₂ · H ₂ 0 ), Silica powder (SiO ₂ ), diatomaceous earth (SiO ₂ · nH ₂ O), sieving pigments such as silica and bentonite; White pigments such as titanium oxide (eg, TiO ₂ ), zinc oxide (ZnO), lithopone, zinc sulfide, lead white (2PbCO ₃ · Pb (OH) ₂ ), and antimony oxide (Sb ₂ O ₃ ); Black pigments such as carbon black, graphite, iron black (Fe ₃ O ₄ ); Yellow such as sulfur lead (PbCrO ₃ ), zinc chromate, cadmium yellow (CdS), lead cyanamide (PbCN ₂ ), titanium yellow (TiO ₂ -NiO-Sb ₂ O ₃ ), strontium yellow (SrCrO ₄ ) Pigments; Iron (Fe ₂ O ₃ ), podium (Pb ₃ O ₄ ), silver (HgS), cadmium red (mixed crystal of CdS and HgS), molybdenum red (mixed crystal of PbCrO ₄ and PbMoO ₄ , PbSO ₄ ), Red pigments such as copper nitrous oxide (Cu ₂ O); Royal Blue (MFe [Fe (CN) ₆ ], M = K, NH ₄ , Na), Ultramarine Blue (2 (Al ₂ Na ₂ Si ₃ O ₁₀ ) · Na ₂ S ₄ ), Cobalt Blue (CoO · Al ₂ O ₃ Blue pigments); Green pigments such as chromium rust (a mixture of PbCrO ₄ and sensitized KFe [Fe (CN) ₆ ]), chromium oxide (Cr ₂ O ₃ ), and chromium hydroxide (Cr ₂ O ₃ · 2H ₂ O); Metal powder pigments such as aluminum powder and bronze powder; And it may be at least one selected from the group consisting of pearl pigments such as natural pearl essences, synthetic pearl pigments. The pigment may be a pigment in which black pigments, extender pigments and white pigments are mixed in a weight ratio of 1:20 to 30: 5 to 20, and preferably 1:25:10.

The pigments vary in particle size from nanometers to millimeters, and in the paint, pigments having a size of less than 10 microns after dispersion are used. When the particle size of the pigment is in nanometer units, the physical properties such as color realization and workability are excellent, but the use is limited because the price is relatively expensive. Can be.

The pigment may be included in an amount of 5 to 30 parts by weight, for example 10 to 25 parts by weight, based on 3 to 25 parts by weight of the alkyd resin. When the content of the pigment is less than 5 parts by weight, the hiding power of the sand mark may be lowered, and when it is more than 30 parts by weight, physical properties such as adhesion of the primer coating composition may be lowered.

Primary solvent

The said 1st solvent is a component for improving the workability of a primer coating composition, and maintaining the thickness of the coating film (primer layer) formed from a primer coating composition.

The first solvent may be used solvents commonly used in primer coating compositions, hydrocarbon solvents such as n-heptane, toluene, xylene, petroleum compounds, or n-hexane (non-polar solvent); Ester solvents (polar solvents) such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, dibasic ester, 3-methoxy butyl acetate, amyl acetate, butyl glycol acetate; Alternatively, ketone solvents (polar solvents) such as methyl ethyl ketone, methyl isobutyl ketone, acetone, diisobutyl ketone, isophorone, or cyclohexanone may be used alone or in combination with each other.

The first solvent may be included in an amount of 40 to 70 parts by weight based on 3 to 25 parts by weight of the alkyd resin. When the content of the first solvent is less than 40 parts by weight, there is a risk that workability is lowered, and when the content of the first solvent is greater than 70 parts by weight, the use of the solvent may cause a problem that the adhesion or durability of the coating film is reduced.

In particular, when the first solvent is a mixed solvent, an ester solvent and a ketone solvent may be included, and the hydrocarbon solvent may be further included therein. In this case, the ester solvent may be included in an amount of 30 to 50 parts by weight, the ketone solvent in an amount of 1 to 10 parts by weight, and the hydrocarbon solvent may be included in an amount of 10 to 20 parts by weight.

<Base coat coating composition>

The paint kit for the SMC material of the present invention may further include a base coat paint composition. The base coat coating composition is for realizing the color of the coating film, it may be a two-component coating composition comprising a resin portion and a curing agent portion.

The resin portion of the base coat coating composition may include a first acrylic polyol resin, a second polyester polyol resin, a pigment, and a second solvent.

First acrylic polyol resin

The first acrylic polyol resin is a component for improving the workability of the base coat coating composition and the surface properties of the coating film (base coat layer) formed from the base coat coating composition.

The first acrylic polyol resin may be prepared by radical solution polymerization of a monomer having an organic acid group, a monomer having a hydroxyl group, a monomer having a vinyl double bond such as an aromatic nonfunctional monomer, an aliphatic nonfunctional monomer, and a pyrolysis initiator. have.

The monomer having an organic acid group may be acrylic acid, methacrylic acid, maleic acid, or the like, or anhydrides thereof, and may be used alone or in combination.

The monomer having a hydroxyl group may be 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxybutyl acrylate, hydroxypropyl methacrylate, caprolactone acrylate, and the like, or these alone or It can be used by mixing.

The aromatic nonfunctional monomer may be styrene, vinyltoluene, or the like, and may be used alone or in combination.

The aliphatic non-functional monomer may be methyl methacrylate, ethyl acrylate, ethyl methacrylate, isobutyl acrylate, normal butyl methacrylate, normal butyl acrylate, isopropyl methacrylate, and the like, alone or It can be used by mixing.

The reaction initiator used in the radical solution polymerization may be benzoyl peroxide, azoisobutyronitrile, t-butylperoxy 2-ethylhexanoate, or the like.

The first acrylic polyol resin may have a solid content of 50 to 70% by weight, for example, 52 to 63% by weight. If the solids content of the first acrylic polyol resin is less than 50% by weight, the solids content of the first acrylic polyol resin is low, the workability is not good, the appearance may be reduced, if the weight is greater than 70% by weight the crack of the coating film is increased This can happen.

The first acrylic polyol resin may have a hydroxyl value of 100 to 180 mgKOH / g, for example, 103 to 176 mgKOH / g. When the hydroxyl value of the first acrylic polyol resin is less than 100 mgKOH / g, the crosslinking density of the coating film is lowered, so that physical properties such as water resistance and weather resistance may be lowered. When the hydroxyl value is more than 180 mgKOH / g, the hardness of the coating film is excessive. It may become so high that cracks may occur.

The first acrylic polyol resin may have a weight average molecular weight (g / mol) of 10,000 to 25,000, for example, 12,000 to 20,000. When the weight average molecular weight (g / mol) of the first acrylic polyol resin is less than 10,000, adhesion of the coating film may be reduced, and when the weight average molecular weight (g / mol) is more than 25,000, workability may be decreased. .

The first acrylic polyol resin may have a glass transition temperature (Tg) of 15 ° C to 45 ° C, for example, 16 ° C to 43 ° C. When the glass transition temperature of the first acrylic polyol resin is less than 15 ° C., the hardness of the coating may be lowered, and when the glass transition temperature is higher than 45 ° C., the appearance characteristics of the coating may be lowered.

The first acrylic polyol resin may be included in 15 to 45 parts by weight, for example 20 to 40 parts by weight. When the content of the first acrylic polyol resin is less than 15 parts by weight, the appearance properties and physical properties of the coating film may be lowered, and when the content of the first acrylic polyol resin is greater than 45 parts by weight, physical properties such as weather resistance of the coating film may be reduced.

Second Polyester Polyol Resin

The second polyester polyol resin is a component for improving appearance characteristics and surface properties of the coating film.

The second polyester polyol resin may be obtained by condensation reaction of a glycol monomer with a monomer having an acid group. The glycol monomer may be, for example, neopentyl glycol, trimethylolpropane, diethylene glycol, triethylene glycol, 1,6-hexanediol, 1,4-butanediol, 1,4-cyclohexaneamitanol, and the like. The monomer having an acid group may be, for example, terephthalic acid, maleic anhydride, fumaric acid, phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, adipic acid and the like.

The second polyester polyol resin may be a solid content of 70 to 90% by weight, for example 75 to 85% by weight. When the solid content of the second polyester polyol resin is less than 70% by weight, the salvability of the coating may be lowered, and the appearance characteristics may be lowered. When the content of the second polyester polyol resin is greater than 90% by weight, the coating may be softened and the hardness may be lowered. have.

The second polyester polyol resin may have a hydroxyl value of 110 to 180 mgKOH / g, for example, may be 113 to 175 mgKOH / g. When the hydroxyl value of the second polyester polyol resin is less than 110 mgKOH / g crosslinking density of the coating film is lowered, there may be a problem in the chemical resistance after curing, when the hydroxyl value exceeds 180 mgKOH / g hardness of the coating film Too high can cause cracks.

The second polyester polyol resin may have a weight average molecular weight (g / mol) of 800 to 2,500, for example 1,000 to 2,000. When the weight average molecular weight (g / mol) of the second polyester polyol resin is less than 800, adhesion of the coating film may be reduced, and when the weight average molecular weight (g / mol) is more than 2,500, workability may be decreased. have.

The second polyester polyol resin may have a glass transition temperature (Tg) of 0 ° C to 30 ° C, for example, 2 ° C to 29 ° C. When the glass transition temperature of the second polyester polyol resin is less than 0 ° C., the hardness of the coating may be reduced, and when the glass transition temperature is more than 30 ° C., the appearance characteristics of the coating may be reduced.

The second polyester polyol resin may be included in an amount of 15 to 40 parts by weight, for example 20 to 30 parts by weight, based on 15 to 45 parts by weight of the first acrylic polyol resin. If the content of the second polyester polyol resin is less than 15 parts by weight, the appearance characteristics and physical properties of the coating film may be lowered. If the content of the second polyester polyol resin is greater than 40 parts by weight, the curing speed may be increased during coating, resulting in a problem of deterioration of workability. Can be.

Pigment

The pigment may be the same as or different from the pigment included in the primer coating composition as a component for mixing with the first acrylic polyol resin and the second polyester polyol resin component to achieve a desired color.

The pigment may be a pigment in which black pigment, extender pigment, and white pigment are mixed at a weight ratio of 1:20 to 30: 5 to 20, and preferably 1:25:10.

The pigment may be included in an amount of 0.5 to 10 parts by weight, for example, 1 to 5 parts by weight, based on 15 to 45 parts by weight of the first acrylic polyol resin. When the content of the pigment is less than 0.5 parts by weight, the color expression is insignificant, the appearance characteristics are lowered, and when it is more than 10 parts by weight, the adhesion of the coating film may be reduced.

2nd solvent

The said 2nd solvent is a component for improving the workability of a basecoat coating composition, and maintaining the thickness of the coating film (basecoat layer) formed from a basecoat coating composition.

The second solvent may be used alone or mixed with each other, the same polar or non-polar solvents as the first solvent used in the primer coating composition.

The second solvent may be included in an amount of 10 to 45 parts by weight based on 15 to 45 parts by weight of the first acrylic polyol resin. If the content of the second solvent is less than 10 parts by weight, the workability may be lowered. If the content of the second solvent is more than 45 parts by weight, the excessive use of the solvent may cause a problem of deterioration of adhesion or durability of the coating film.

In particular, when the second solvent is a mixed solvent, an ester solvent and a ketone solvent may be included, and the hydrocarbon solvent may be further included therein. In this case, the ester solvent may be contained in an amount of 5 to 15 parts by weight, the ketone solvent in an amount of 1 to 10 parts by weight, and the hydrocarbon solvent may be included in an amount of 10 to 20 parts by weight.

<Clear coat coating composition>

Paint kit for SMC material of the present invention may further comprise a clear coat paint composition. The clear coat coating composition is for improving the appearance characteristics and durability of the coating film, it may be a two-component coating composition comprising a resin portion and a curing agent portion.

The resin portion of the clear coat coating composition may include a second acrylic polyol resin, a third polyester polyol resin, and a third solvent.

2nd acrylic polyol resin

The second acrylic polyol resin is a component for improving the workability of the clear coat coating composition and the surface properties of the coating film (clear coat layer) formed from the clear coat coating composition, and is used in the base coat coating composition. May be the same as or different from each other.

The second acrylic polyol resin may have a solid content of 55 to 75% by weight, for example, 58 to 70% by weight. When the solid content of the second acrylic polyol resin is less than 55% by weight, the salvage property of the coating film may be lowered, and when the content exceeds 75% by weight, the viscosity of the second acrylic polyol resin may be increased to reduce workability. Can be.

The second acrylic polyol resin may have a hydroxyl value of 70 to 160 mgKOH / g, for example, 73 to 155 mgKOH / g. When the hydroxyl value of the second acrylic polyol resin is less than 70 mgKOH / g may be weak chemical resistance, when the hydroxyl value exceeds 160 mgKOH / g may be weak impact resistance of the coating film.

The second acrylic polyol resin may have a weight average molecular weight (g / mol) of 6,000 to 15,000, for example, 7,000 to 13,000. When the weight average molecular weight (g / mol) of the second acrylic polyol resin is less than 6,000, adhesion of the coating film may be reduced, and when the weight average molecular weight (g / mol) is more than 15,000, workability may be decreased. .

The second acrylic polyol resin may have a glass transition temperature (Tg) of 50 ° C to 85 ° C, for example, 51 ° C to 84 ° C. When the glass transition temperature of the second acrylic polyol resin is less than 50 ° C., the hardness of the coating may be reduced, and when the glass transition temperature is higher than 85 ° C., the appearance characteristics of the coating may be reduced.

The second acrylic polyol resin may be included in an amount of 55 to 80 parts by weight, for example, 60 to 75 parts by weight. When the content of the second acrylic polyol resin is less than 55 parts by weight, the appearance properties and physical properties of the coating film may be lowered. When the content of the second acrylic polyol resin is greater than 80 parts by weight, physical properties such as weather resistance of the coating film may be reduced.

Tertiary polyester polyol resin

The third polyester polyol resin may be the same as the second polyester polyol resin used in the base coat coating composition as a component for improving appearance characteristics and surface properties of the coating film, and may be different.

The third polyester polyol resin may be a solid content of 65 to 95% by weight, for example 70 to 90% by weight. If the solids content of the third polyester polyol resin is less than 65% by weight, the salvability of the coating film may be lowered, and the appearance characteristics may be lowered. If the solids content is more than 95% by weight, the coating film may be softened to decrease hardness.

The third polyester polyol resin may have a hydroxyl value of 70 to 200 mgKOH / g, for example 71 to 195 mgKOH / g. When the hydroxyl value of the third polyester polyol resin is less than 70 mgKOH / g may be weak water resistance of the coating film, if the hydroxyl value exceeds 200 mgKOH / g may be reduced pot life of the coating.

The third polyester polyol resin may be included in an amount of 1 to 20 parts by weight, for example, 3 to 15 parts by weight, based on 55 to 80 parts by weight of the second acrylic polyol resin. If the content of the third polyester polyol resin is less than 1 part by weight, the appearance properties and physical properties of the coating film may be lowered. If the content of the third polyester polyol resin is greater than 20 parts by weight, the problem of deterioration of workability may occur due to an increase in curing speed during coating. Can be.

Tertiary solvent

The third solvent is a component for improving the workability of the clear coat coating composition and maintaining the thickness of the coating film (clear coat layer) formed from the clear coat coating composition.

The third solvent may be used alone or mixed with each other, either polar or nonpolar solvents such as the first solvent or the second solvent used in the primer coating composition or the base coat coating composition.

The third solvent may be included in an amount of 2 to 30 parts by weight, for example, in an amount of 10 to 30 parts by weight, based on 55 to 80 parts by weight of the second acrylic polyol resin. When the content of the third solvent is less than 2 parts by weight, there is a risk that workability is lowered, and when the content of the third solvent is greater than 30 parts by weight, a problem of deterioration of adhesion or durability of the coating due to excessive use of the solvent may occur.

In particular, when the third solvent is a mixed solvent, an ester solvent and a ketone solvent may be included, and the hydrocarbon solvent may be further included. In this case, the ester solvent may be contained in an amount of 1 to 15 parts by weight, the ketone solvent may be included in an amount of 1 to 15 parts by weight, and the hydrocarbon solvent may be included in an amount of 1 to 10 parts by weight.

<Hardener part of each composition>

Each of the primer coating composition, the base coat coating composition, and the clear coat coating composition includes a curing agent portion.

Each of the curing agent parts included in the primer coating composition, the base coat coating composition, and the clear coat coating composition may be the same as or different from each other.

The hardening | curing agent part of each said coating composition hardens the resin part of each coating composition, and can contain a polyisocyanate type hardening | curing agent.

The isocyanate functional group of the polyisocyanate-based curing agent reacts with the hydroxyl group of the first acrylic polyol resin, the second acrylic polyol resin, the first polyester polyol resin, the second polyester polyol resin, the third polyester polyol resin, or the alkyd resin. To form a urethane bond.

As an example of the polyisocyanate-based curing agent, one or more selected from homopolymers and modified bodies of methylene diisocyanate, toluene diisocyanate and xylene diisocyanate which are excellent in curing rate, adhesion, coating hardness, heat resistance, etc. When the polyisocyanate is used, it is excellent in adhesiveness and moisture resistance to various plastic molded articles, coating hardness, etc., and has an advantage in terms of economy due to relatively low price.

In addition, at least one of hexamethylene diisocyanate, isophorone diisocyanate and modified substances may be selected and used to prevent yellowing of the coating film although it is relatively expensive.

The polyisocyanate curing agent may be diluted with a suitable diluent to form a curing agent composition, and then stored in a separate container and sufficiently stirred before use. Here, the diluent may use a thinner for dilution, which is commonly used, and the dilution rate of the polyisocyanate diluent is a hydroxyl equivalent of the resin and an isocyanate functional group of the curing agent when the dilution ratio of the polyisocyanate diluent is mixed with the main mixture and the polyisocyanate diluent. It may be calculated and determined to occur, and the mixing of the hydroxyl group and the isocyanate functional group is preferably 1: 0.9 to 1: 1.2 based on the equivalent ratio. This is because when the mixed equivalent ratio is greater than 1: 1.2, excess isocyanate is generated and when less than 1: 0.9, there is a problem that the degree of curing is poor.

<Additive of resin part or hardening | curing agent part of each composition>

Meanwhile, the primer coating composition, the base coat coating composition, and the clear coat coating composition of the present invention may further include an additive in the resin portion or the curing agent portion for the purpose of adjusting the surface properties of the coating material, or promoting curing. Here, the additive may be a surface conditioner, a curing accelerator, an ultraviolet absorber, a wetting agent, an antifoaming agent, a thickener, and the like, and may further include materials known in the art.

The surface modifier is a component for adjusting the surface tension. The surface modifier may be a compound generally used in the coating composition, for example, may include a mixture of at least one of a polysiloxane surface modifier and a non-silicone surface modifier. The polysiloxane-based surface modifiers include silicone oils, silicone-based surfactants, silicone-based synthetic lubricants, and the like, and the non-silicone-based surface modifiers substantially free of silicon (Si) include lower alcohols, mineral oils, oleic acid, polypropylene glycol, and glycerin. Higher fatty acid esters, fluorine-containing surfactants, and the like. The content of the surface modifier is not particularly limited, but may be included in 0.1 to 1 part by weight. When the content of the surface modifier is included in less than 0.1 part by weight, the appearance characteristics of the coating film is lowered, and when included in excess of 1 part by weight, physical properties such as adhesion of the coating film may be reduced.

The said hardening accelerator is a component for promoting hardening of a coating composition, and shortening coating film drying and hardening time. The curing accelerator may be selected from, for example, tetramethyl butane diamine, bicyclooctane, dibutyltin dilaurate, triethylene diamine, and mixtures thereof. The content of the curing accelerator is not particularly limited, but may be included in an amount of 0.01 to 1 part by weight. When the content of the curing accelerator is included in less than 0.01 parts by weight may reduce the coating film drying and physical properties of the coating film, when included in more than 1 part by weight may reduce the appearance properties of the coating film and the pot life.

The ultraviolet absorber is a component for preventing surface defects and gloss loss of the coating film and increasing weather resistance. As an example of the ultraviolet absorbent may be mentioned hydroxy phenyl benzotriazole (Hydroxyphenyl Benzotriazole). The amount of the ultraviolet absorbent is not particularly limited, but may be included in an amount of 1 to 10 parts by weight. When the content of the ultraviolet absorber is included in less than 1 part by weight, a problem of deterioration of weather resistance of the coating may occur, and when included in excess of 10 parts by weight, a problem of cost increase may occur.

The wetting agent is a component for improving the wettability and leveling property of the coating film by controlling the surface tension of the coating composition, and the wetting agent may be a conventional wetting agent used in paints in the art. The amount of the wetting agent is not particularly limited, but may be included in an amount of 0.5 to 3 parts by weight. When the content of the humectant is included outside the range, the wettability and leveling property of the coating film may be lowered.

The antifoaming agent is a mixture of lipophilic and polysiloxane, which is a component that improves the appearance characteristics of the coating film by breaking bubbles generated during coating. The amount of the antifoaming agent is not particularly limited, but may be included in an amount of 0.1 to 1.5 parts by weight. When the content of the antifoaming agent is included outside the above range, bubbles are generated when coating the coating composition containing the antifoaming agent may reduce the appearance characteristics of the coating film.

The thickener is a component for controlling the viscosity of the coating composition and imparting thixotropy to prevent the flow of the coating composition during coating, and the thickener may be a conventional thickener used in paints in the art. The amount of the thickener is not particularly limited, but may be included in an amount of 0.1 to 1 part by weight. When the content of the thickener is included outside the above range it may be difficult to prevent the flow when painting the coating composition.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are intended to specifically illustrate the present invention, the contents of the present invention is not limited by the following examples.

[Examples and Comparative Examples]

Example 1

Primer coating composition

The 1-1 polyester polyol resin and the pigment were placed in a container, mixed at a low speed using a stirrer, and the pigment was dispersed using a ring mill disperser, followed by alkyd resin 1-1, a surface conditioner, a curing accelerator, and a first A solvent was added and stirred for 30 minutes, and a solvent was further used as needed to adjust the viscosity to 25 to 35 sec (FORD CUP # 4) to prepare a resin part (topic). Thereafter, a polyisocyanate curing agent (MDI) was added to the mixture in a ratio of 1: 1 of the equivalent: curing agent to prepare a primer coating composition. The viscosity of the prepared primer coating composition was adjusted to 12 to 13 seconds (FORD CUP # 4) with dilution thinner.

Base Coat Paint Composition

After the 2-1 polyester polyol resin and the pigment were put in a container and mixed at a low speed using a stirrer, the pigment was dispersed using a ring mill disperser, and then the 1-1 acrylic polyol resin, an ultraviolet absorber, a surface conditioner, A curing accelerator and a second solvent were added thereto, stirred for 30 minutes, and, if necessary, a solvent was further used to adjust the viscosity to 25 to 35 sec (FORD CUP # 4) to prepare a resin part (topic). Thereafter, a polyisocyanate curing agent (HDI Trimer) was added to the mixture in a ratio of 1: 1 by weight of the main agent: curing agent to prepare a base coat coating composition. The viscosity of the prepared base coat coating composition was adjusted to 14 to 17 seconds (FORD CUP # 4) with dilution thinner.

Clear coat coating composition

After putting the 2-1 acrylic polyol resin and the 3-1 polyester polyol resin into the container and mixing at a low speed using a stirrer, a UV absorber, a surface conditioner, a curing accelerator and a third solvent were added thereto, followed by stirring for 30 minutes, As necessary, a solvent was further used to adjust the viscosity to 25 to 35 sec (FORD CUP # 4) to prepare a resin part (topic). Thereafter, a polyisocyanate curing agent (HDI Trimer) was added to the mixture in a ratio of 1: 1 by weight of the main agent: curing agent to prepare a clear coat coating composition. The viscosity of the prepared clear coat coating composition was adjusted to 14 to 17 seconds (FORD CUP # 4) with dilution thinner.

[Examples 2 to 9]

In Example 1, the primer coating composition, the base coat coating composition, and the clear coat coating composition were manufactured in the same manner as in Example 1, except that the compositions described in Tables 1 to 3 were followed.

division Example 1 Example 2 Example 3 primer Base clear primer Base clear primer Base clear 1-1 polyester polyol resin 22 17 22 2-1 polyester polyol resin 26 26 2-3-3 polyester polyol resin 26 3-1 polyester polyol resin 5 12 12 Alkyd Resin 1-1 10 15 Alkyd Resin 1-2 10 1-1 acrylic polyol resin 30 30 1-2 acrylic polyol resin 30 2-1 acrylic polyol resin 67 60 2-3 acrylic polyol resin 60 Pigment 15 3 15 3 15 3 Primary solvent 52.7 52.7 52.7 2nd solvent 37.3 37.3 37.3 Tertiary solvent 25.3 25.3 25.3 UV absorbers 3 2.4 3 2.4 3 2.4 Surface conditioner 0.2 0.5 0.2 0.2 0.5 0.2 0.2 0.5 0.2 Curing accelerator 0.1 0.2 0.1 0.1 0.2 0.1 0.1 0.2 0.1 Total (% by weight) 100 100 100 100 100 100 100 100 100

division Example 4 Example 5 Example 6 primer Base clear primer Base clear primer Base clear 1-2 polyester polyol resin 22 1-3 polyester polyol resin 17 1-4 polyester polyol resin 22 2-1 polyester polyol resin 26 26 2-2 polyester polyol resin 26 3-1 polyester polyol resin 5 3-2 polyester polyol resin 12 3-3 polyester polyol resin 5 Alkyd Resin 1-1 15 Alkyd Resin 1-5 10 Alkyd Resin 1-7 10 1-1 acrylic polyol resin 30 1-3 Acrylic Polyol Resin 30 1-4 acrylic polyol resin 30 2-1 acrylic polyol resin 60 2-4 acrylic polyol resin 67 2-5 acrylic polyol resin 67 Pigment 15 3 15 3 15 3 Primary solvent 52.7 52.7 52.7 2nd solvent 37.3 37.3 37.3 Tertiary solvent 25.3 25.3 25.3 UV absorbers 3 2.4 3 2.4 3 2.4 Surface conditioner 0.2 0.5 0.2 0.2 0.5 0.2 0.2 0.5 0.2 Curing accelerator 0.1 0.2 0.1 0.1 0.2 0.1 0.1 0.2 0.1 Total (% by weight) 100 100 100 100 100 100 100 100 100

division Example 7 Example 8 Example 9 primer Base clear primer Base clear primer Base clear 1-1 polyester polyol resin 17 1-3 polyester polyol resin 22 1-5 polyester polyol resin 17 2-3-3 polyester polyol resin 26 2-4 polyester polyol resin 26 2-5 polyester polyol resin 26 3-1 polyester polyol resin 12 3-2 polyester polyol resin 5 3-3 polyester polyol resin 12 Alkyd Resin 1-3 10 Alkyd Resin 1-4 15 Alkyd Resin 1-6 15 1-1 acrylic polyol resin 30 1-4 acrylic polyol resin 30 1-5 acrylic polyol resin 30 2-2 acrylic polyol resin 67 2-4 acrylic polyol resin 60 2-5 acrylic polyol resin 60 Pigment 15 3 15 3 15 3 Primary solvent 52.7 52.7 52.7 2nd solvent 37.3 37.3 37.3 Tertiary solvent 25.3 25.3 25.3 UV absorbers 3 2.4 3 2.4 3 2.4 Surface conditioner 0.2 0.5 0.2 0.2 0.5 0.2 0.2 0.5 0.2 Curing accelerator 0.1 0.2 0.1 0.1 0.2 0.1 0.1 0.2 0.1 Total (% by weight) 100 100 100 100 100 100 100 100 100

[Comparative Examples 1 to 6]

In Example 1, except that according to the composition shown in Table 4 and Table 5, the primer coating composition, base coat coating composition, clear coat coating composition of Comparative Examples 1 to 6 in the same manner as in Example 1 Prepared.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 primer Base clear primer Base clear primer Base clear 1-1 polyester polyol resin 12 12 22 2-1 polyester polyol resin 26 26 26 3-1 polyester polyol resin 5 15 5 Alkyd Resin 1-1 20 20 Alkyd Resin 1-8 10 1-1 acrylic polyol resin 30 30 30 2-1 acrylic polyol resin 67 57 67 Pigment 15 3 15 3 15 3 Primary solvent 52.7 52.7 52.7 2nd solvent 37.3 37.3 37.3 Tertiary solvent 25.3 25.3 25.3 UV absorbers 3 2.4 3 2.4 3 2.4 Surface conditioner 0.2 0.5 0.2 0.2 0.5 0.2 0.2 0.5 0.2 Curing accelerator 0.1 0.2 0.1 0.1 0.2 0.1 0.1 0.2 0.1 Total (% by weight) 100 100 100 100 100 100 100 100 100

division Comparative Example 4 Comparative Example 5 Comparative Example 6 primer Base clear primer Base clear primer Base clear 1-1 polyester polyol resin 22 17 1-2 polyester polyol resin 17 2-1 polyester polyol resin 26 2-2 polyester polyol resin 26 2-3-3 polyester polyol resin 26 3-1 polyester polyol resin 12 3-2 polyester polyol resin 5 3-3 polyester polyol resin 5 Alkyd Resin 1-9 10 Alkyd Resin 1-10 15 Alkyd Resin 1-11 15 1-1 acrylic polyol resin 30 30 1-2 acrylic polyol resin 30 2-2 acrylic polyol resin 67 2-3 acrylic polyol resin 60 2-5 acrylic polyol resin 67 Pigment 15 3 15 3 15 3 Primary solvent 52.7 52.7 52.7 2nd solvent 37.3 37.3 37.3 Tertiary solvent 25.3 25.3 25.3 UV absorbers 3 2.4 3 2.4 3 2.4 Surface conditioner 0.2 0.5 0.2 0.2 0.5 0.2 0.2 0.5 0.2 Curing accelerator 0.1 0.2 0.1 0.1 0.2 0.1 0.1 0.2 0.1 Total (% by weight) 100 100 100 100 100 100 100 100 100

The components used in the Examples and Comparative Examples are as follows.

1-1-1 polyester polyol resin: 80 weight% of solid content, 145 mgKOH / g of hydroxyl value, 6,000 g / mol of weight average molecular weight, -20 degreeC of glass transition temperature.

1-2 polyester polyol resin: solid content 75 wt%, hydroxyl value 112 mgKOH / g, weight average molecular weight 7,000 g / mol, glass transition temperature -22 ° C

1-3 polyester polyol resin: 85 weight% of solid content, hydroxyl value 177 mgKOH / g, weight average molecular weight 5,000g / mol, glass transition temperature -19 degreeC

1-4 polyester polyol resin: solid content of 80% by weight, hydroxyl value of 136 mgKOH / g, weight average molecular weight 6,500g / mol, glass transition temperature of -7 ° C

1-5 polyester polyol resin: solid content of 80% by weight, hydroxyl value of 164 mgKOH / g, weight average molecular weight 7,500 g / mol, glass transition temperature of -33 ° C

2-1 polyester polyol resin: 79 weight% of solid content, 145 mgKOH / g hydroxyl value, weight average molecular weight 1,500 g / mol, glass transition temperature 17 degreeC

2-2 polyester polyol resin: Solid content 74 weight%, hydroxyl value 113 mgKOH / g, weight average molecular weight 2,000 g / mol, glass transition temperature 16 degreeC

2-3 polyester polyol resin: 80 weight% of solid content, 175 mgKOH / g of hydroxyl value, 1,000 g / mol of weight average molecular weight, 18 degreeC of glass transition temperature

2-4 polyester polyol resin: 80 wt% of solid content, 142 mgKOH / g hydroxyl value, 1,400 g / mol weight average molecular weight, glass transition temperature 2 ° C

2-5 polyester polyol resin: 80 weight% of solid content, 148 mgKOH / g of hydroxyl value, 1,800 g / mol of weight average molecular weight, glass transition temperature of 29 degreeC

3-1 Polyester Polyol Resin: 80 wt% Solids, 125 mgKOH / g hydroxyl value

2-3-2 polyester polyol resin: 70 weight% of solid content, 71 mgKOH / g hydroxyl value

3-3 polyester polyol resin: 90 wt% of solid content, 195 mgKOH / g hydroxyl value

Alkyd Resin 1-1: 65 wt% solids, 182 mgKOH / g hydroxyl value, 12,000 g / mol weight average molecular weight, 21 iodine value

Alkyd Resin 1-2: 60 wt% Solids, 174 mgKOH / g hydroxyl value, 9,500 g / mol weight average molecular weight, 18 iodine

Alkyd Resin 1-3: 60 wt% solids, 169 mgKOH / g hydroxyl value, 11,000 g / mol weight average molecular weight, 15 iodine value

Alkyd Resin 1-4: 70 wt% of solid content, 186 mgKOH / g hydroxyl value, 16,000 g / mol weight average molecular weight, 25 iodine value

Alkyd Resin 1-5: 70 wt% solids, 190 mgKOH / g hydroxyl value, 11,500 g / mol weight average molecular weight, 28 iodine

Alkyd Resin 1-6: 65 wt% solids, 133 mgKOH / g hydroxyl value, 13,000 g / mol weight average molecular weight, 20 iodine

Alkyd Resin 1-7: 65 wt% solids, 207 mgKOH / g hydroxyl value, 14,000 g / mol weight average molecular weight, 21 iodine value

Alkyd Resin 1-8: 65 wt% solids, 120 mgKOH / g hydroxyl value, 12,000 g / mol weight average molecular weight, 12 iodine value

 Alkyd Resin 1-9: 65 wt% solids, 225 mgKOH / g hydroxyl value, 10,000 g / mol weight average molecular weight, 31 iodine

Alkyd Resin 1-10: 65 wt% solids, 185 mgKOH / g hydroxyl value, 12,500 g / mol weight average molecular weight, 13 iodine value

Alkyd Resin 1-11: 65 wt% solids, 127 mgKOH / g hydroxyl value, 13,000 g / mol weight average molecular weight, 25 iodine

1-1-1 acrylic polyol resin: 58 weight% of solid content, 138 mgKOH / g hydroxyl value weight average molecular weight 16,000 g / mol, glass transition temperature 30 degreeC

1-2 acrylic polyol resin: 52 weight% of solid content, 103 mgKOH / g of hydroxyl value weight average molecular weight 20,000 g / mol, glass transition temperature 32 degreeC

1-3 acrylic polyol resin: 63 weight% of solid content, 176 mgKOH / g hydroxyl value weight average molecular weight 12,000 g / mol, glass transition temperature 33 degreeC

1-4 acrylic polyol resin: 60 weight% of solid content, hydroxyl value 142 mgKOH / g weight average molecular weight 18,000 g / mol, glass transition temperature 16 degreeC

1-5 acrylic polyol resin: 55 weight% of solid content, 133 mgKOH / g hydroxyl value weight average molecular weight 17,000 g / mol, glass transition temperature 43 degreeC

2-1 Acrylic polyol resin: 64 weight% of solid content, 113 mgKOH / g hydroxyl value weight average molecular weight 9,000 g / mol, glass transition temperature 67 degreeC

2-2 acrylic polyol resin: 58 weight% of solid content, 73 mgKOH / g hydroxyl value weight average molecular weight 13,000 g / mol, glass transition temperature 65 degreeC

2-3 acrylic polyol resin: solid content 70 weight%, hydroxyl value 155 mgKOH / g weight average molecular weight 7,000 g / mol, glass transition temperature 69 degreeC

2-4 acrylic polyol resin: 65 wt% of solid content, 115 mgKOH / g of hydroxyl value weight average molecular weight 9,500 g / mol, glass transition temperature of 51 ° C

2-5 acrylic polyol resin: 65 weight% of solid content, hydroxyl value 117 mgKOH / g weight average molecular weight 8,500 g / mol, glass transition temperature 84 degreeC

Ultraviolet Light Absorber: Hydroxyphenyl Benzotriazole

Pigment: Black pigment (MONARCH 1300): Constitution pigment (BSM-MC): White pigment (CR-97) = 1: 25: 10

Surface regulator: Polysiloxane-based surface modifier (BYK306)

Curing Accelerator: Dibutyltin Dilaurate

1st solvent: xylene: butyl acetate: toluene: ethyl acetate: methyl isobutyl ketone = 5: 34: 11: 7: 1

Second solvent: butyl acetate: toluene: xylene: methyl isobutyl ketone = 10: 12: 6: 1

Third solvent: butyl acetate: toluene: xylene: methyl isobutyl ketone = 4: 1: 3: 1

Experimental Example Evaluation of Appearance and Physical Properties of Coating Film

After coating the primer coating composition (dry coating film thickness: 20-25 microns) obtained in the above Examples and Comparative Examples on the raw material (SMC), it was allowed to stand at room temperature for 5 minutes. The base coat coating composition (dry coating film thickness: 25-30 micron) was apply | coated on it, and was left to stand at room temperature for 5 minutes. The clear coat coating composition (dry coating film thickness: 30-35 microns) obtained in the above Examples and Comparative Examples was coated thereon, and the final multilayer coating film was cured with hot air at 80 ° C. for 30 minutes.

Workability during coating, appearance and physical properties of the final multilayer coating film were measured as follows and evaluated according to the following evaluation criteria, and the results are shown in Tables 6 and 7 below.

<Evaluation Criteria>

◎-Excellent, ○-Good, △-Normal, X-defect

1) Painting workability

Two round trips were applied to a 30 cm x 40 cm tin plate with 61 IWATA cases to compare the degree of atomization, smoothness, and film salinity of the coating.

2) Appearance

The degree of bubbles, foreign matters, spots, grooves, hiding power, salinity and smoothness of the coating film surface was compared.

3) adhesion

Based on the ASTM D3359 tape adhesion test method, the degree of peeling after the tape adhesion test was observed in 100 1 mm x 1 mm scales.

4) water resistance

After coating the finished coating film in a 40 ℃ thermostat for 10 days, the adhesion test and appearance evaluation were carried out.

5) Impact resistance

After the 0.5 kg weight was dropped from the height of 30 cm with the specified impact resistance tester, the appearance was visually compared.

6) Weather resistance

The film appearance, color difference, and adhesion after exposure to an energy of 2,500 kJ in a Xenon Weatherometer tester environment were compared.

7) hardness

Apply a standard pencil (penal hardness 2B to HB) on the test piece, draw a straight line of about 5 cm, and check the surface state of the coating film.

8) Chemical resistance

A weight of 4.9 N load (4 cm in diameter) was wrapped with gauze, and the surface was visually inspected by rubbing the surface of the coating film 10 times with enough gasoline, polished wax, glass cleaner, ethyl alcohol, and acetone, respectively. After 1 hour at room temperature, and after leaving for 3 hours in a constant temperature chamber of 80 ± 2 ℃ condition to take out the surface state of the coating film.

Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Painting workability ◎ ◎ ◎ ◎ ○ ○ ◎ ◎ ◎ Exterior ◎ ◎ ○ ○ ○ ◎ ◎ ○ ◎ Adhesion ◎ ◎ ◎ ◎ ○ ○ ◎ ◎ ○ Water resistance ◎ ◎ ○ ○ ◎ ◎ ○ ◎ ◎ Impact resistance ◎ ◎ ○ ◎ ◎ ◎ ◎ ◎ ◎ Weather resistance ◎ ◎ ○ ○ ◎ ◎ ◎ ◎ ◎ Hardness ◎ ◎ ○ ○ ◎ ○ ◎ ○ ○ Chemical resistance 10 round trips ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ 1 hour later ◎ ◎ ◎ ◎ ○ ◎ ○ ◎ ◎

Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Painting workability ◎ ◎ ◎ ◎ △ ◎ Exterior ○ △ ◎ △ ○ △ Adhesion ○ ○ △ ◎ △ ◎ Water resistance △ △ △ ○ ○ X Impact resistance ◎ ◎ ○ ○ ○ ◎ Weather resistance △ △ ○ ○ △ ◎ Hardness ○ ○ ◎ △ △ X Tolerance
Character 10 round trips ○ ○ ○ ○ ○ ○ 1 hour later △ △ △ △ △ △

As shown in Table 6 and Table 7, the coating film prepared by using the coating composition of Examples 1 to 9 according to the present invention has excellent coating workability and appearance, adhesion, water resistance, impact resistance, weather resistance, hardness, While excellent durability, such as chemical resistance, the coating film prepared using the coating composition of Comparative Examples 1 to 6 was inferior to the coating properties, such as appearance characteristics, adhesion, water resistance, weather resistance, hardness, chemical resistance.

Claims (8)

A resin part comprising 3 to 25 parts by weight of alkyd resin, 5 to 35 parts by weight of the first polyester polyol resin, 5 to 30 parts by weight of the pigment, and 40 to 70 parts by weight of the first solvent; And a curing agent portion; a paint kit for an SMC material comprising a primer coating composition comprising a. The method according to claim 1,
The first polyester polyol resin has a solid content of 70 to 90% by weight, a hydroxyl value of 110 to 180 mgKOH / g, a weight average molecular weight of 3,000 to 10,000, a glass transition temperature of -35 to -5 ° C, and the alkyd resin is a solid content 50 to 80% by weight, hydroxyl value is 130 to 210 mgKOH / g, weight average molecular weight of 9,000 to 17,000, iodine value 15 to 28 paint kit for SMC material. The method according to claim 1,
A resin portion comprising 15 to 45 parts by weight of the first acrylic polyol resin, 15 to 40 parts by weight of the second polyester polyol resin, 0.5 to 10 parts by weight of the pigment, and 10 to 45 parts by weight of the second solvent; And a curing agent portion; a paint kit for an SMC material further comprising a base coat coating composition comprising a. The method according to claim 3,
The first acrylic polyol resin has a solid content of 50 to 70% by weight, a hydroxyl value of 100 to 180 mgKOH / g, a weight average molecular weight of 10,000 to 25,000, a glass transition temperature of 15 to 45 ° C, and the second polyester polyol resin Solid content 70 to 90% by weight, hydroxyl value of 110 to 180 mgKOH / g, weight average molecular weight of 800 to 2,500, glass transition temperature 0 to 30 ℃ coating kit for materials. The method according to claim 1,
A resin part comprising 55 to 80 parts by weight of the second acrylic polyol resin, 1 to 20 parts by weight of the third polyester polyol resin, and 2 to 30 parts by weight of the third solvent; And a curing agent portion; a paint kit for an SMC material further comprising a clear coat coating composition comprising a. The method according to claim 5,
The second acrylic polyol resin has a solid content of 55 to 75% by weight, a hydroxyl value of 70 to 160 mgKOH / g, a weight average molecular weight of 6,000 to 15,000, a glass transition temperature of 50 to 85 ° C, and the third polyester polyol resin Paint kit for SMC material having a solid content of 65 to 95% by weight, hydroxyl value of 70 to 200 mgKOH / g. The method according to any one of claims 1 to 6,
The resin part and the curing agent part further comprises at least one selected from the group consisting of surface modifiers, ultraviolet absorbers, curing accelerators, wetting agents, defoamers and thickeners, SMC material paint kit. The method according to any one of claims 1 to 6,
The hardener is a coating kit for SMC material containing a polyisocyanate-based hardener.