KR102468328B1 - Coating kit for hot-stamped metalic materials - Google Patents

Abstract

The present invention relates to a paint kit for a hot-stamped metal material, comprising 5 to 15 parts by weight of an acrylic resin, 25 to 50 parts by weight of a first acrylic polyol resin, 20 to 45 parts by weight of a second acrylic polyol resin, and 10 to 15 parts by weight of a first solvent. Resin part containing 30 parts by weight; And a curing agent part; a primer coating composition comprising a; and 10 to 50 parts by weight of a third acrylic polyol resin, 1 to 30 parts by weight of a fourth acrylic polyol resin, 5 to 40 parts by weight of a polyester polyol resin, and 10 to 40 parts by weight of a second solvent; And a curing agent part; It provides a paint kit for a hot-stamped metal material comprising a clear coat paint composition comprising a.

Description

Coating kit for hot-stamped metal materials {COATING KIT FOR HOT-STAMPED METALIC MATERIALS}

The present invention relates to a paint kit, and more particularly, to a paint kit suitable for forming a multilayer paint film on a hot-stamping material.

Among injection molding members applied to the interior or exterior of automobiles, the surface of the plastic product is plated to protect the surface from physical or chemical damage or to impart a luxurious metallic feel to the exterior. For example, in the case of an automobile grill, all parts made of an ABS (Acrylonitrile Butadiene Styrene copolymer) resin are plated with chrome, and other parts of the plated chrome are painted in color except for some areas of the plated chrome. It is manufactured in a process that allows chrome plating to remain only on the part.

In this way, when chrome plating is performed on a plastic material, serious environmental problems are emerging in the process of treating wastewater generated during the process, and a technology capable of replacing such a chrome plating process is required.

As one of the technologies that can replace the chrome plating process as described above, a hot-stamping process has been developed. The hot-stamping process is a method in which a metal thin film such as aluminum is placed on a plastic material and then pressed to attach the metal to the plastic material, thereby imparting a metallic feel to the surface of the plastic material.

However, the surface of the metal attached through the hot-stamping process as described above still has a problem in that the surface is not protected from physical and chemical damage, and it is necessary to develop a paint to protect it. In this regard, semi-glossy type paints are being mass-produced, but in terms of aesthetics, the demand for glossy type paints is gradually increasing. to be.

The present invention is to provide a paint kit for hot-stamped metal materials.

In order to achieve the above object, one aspect of the present invention is 5 to 15 parts by weight of an acrylic resin, 25 to 50 parts by weight of a first acrylic polyol resin, 20 to 45 parts by weight of a second acrylic polyol resin, and 10 to 30 parts by weight of a first solvent A resin part including a weight part; And a curing agent part; a primer coating composition comprising a; and 10 to 50 parts by weight of a third acrylic polyol resin, 1 to 30 parts by weight of a fourth acrylic polyol resin, 5 to 40 parts by weight of a polyester polyol resin, and 10 to 40 parts by weight of a second solvent; And a curing agent part; It provides a paint kit for a hot-stamped metal material comprising a clear coat paint composition comprising a.

The paint kit of the present invention can form a multi-layered protective film capable of protecting hot-stamped metal materials, has excellent adhesion and workability to metal materials, and the paint film formed using the same has water resistance, high-pressure car washability and weather resistance. There is an excellent effect on physical properties such as.

Hereinafter, the present invention will be described in detail.

The present invention provides a paint kit for hot-stamped metal materials.

The paint kit for the hot-stamped metal material of the present invention is to solve the problem of corrosion of the metal substrate, and the primer paint composition for securing adhesion and physical properties with the metal substrate and the clear for securing the appearance and durability of the coating film It contains a coat paint composition. A detailed description of the paint kit for hot-stamped metal materials of the present invention is as follows.

<Primer coating composition>

The primer coating composition included in the coating kit for hot-stamped metal materials of the present invention is a coating composition that can be coated on a metal substrate, specifically, an aluminum substrate of a hot-stamping part to form a primer layer, and is additionally formed thereon It is for improving the adhesion between the layer and the metal substrate and the physical properties of the finally formed coating film, and may be a two-component coating composition including a resin part and a curing agent part. Here, the hot-stamping part may be a material in which aluminum is attached to the plastic material by placing a metal, for example, an aluminum thin plate on the plastic material and then pressing it.

The resin part of the primer coating composition may include an acrylic resin, first and second acrylic polyol resins, and a first solvent.

acrylic resin

The acrylic resin is a component for improving the workability of the primer coating composition, and a thermoplastic acrylic resin or a thermosetting acrylic resin may be used, and in particular, a thermoplastic acrylic resin may be used.

The acrylic resin may be prepared by radical polymerization of monomers having a double bond, such as an acrylic or vinyl monomer, and a thermal decomposition initiator in a solution. The acrylic or vinyl monomers may include non-functional monomers, carboxyl monomers, and vinyl monomers.

The non-functional monomer is, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, N-butyl acrylate, ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl meth Acrylate, lauryl methacrylate, etc. may be used, and these may be used alone or in combination.

The carboxylic acid monomer may be, for example, acrylic acid, methacrylic acid, maleic acid, itaconic acid, and chromonic acid, and these may be used alone or in combination.

Specific examples of the vinyl-based monomer include acrylamide, N-methylolacrylamide, glycidyl methacrylate, styrene, vinyltoluene, acrylonitrile, and vinyl acetate, which may be used alone or in combination. can

The acrylic resin may have a solid content of 40 to 60% by weight, for example, 43 to 56% by weight or 48 to 52% by weight. When the solid content of the acrylic resin is less than 40% by weight, the solid content is low, so workability is poor, and the appearance properties of the coating film may be deteriorated. can

The acrylic resin may have a glass transition temperature of 70 to 120 °C, for example, 75 to 115 °C or 80 to 110 °C. When the glass transition temperature of the acrylic resin is less than 70 ° C, the hardness of the coating film may be low, and when the glass transition temperature exceeds 120 ° C, the hardness of the coating film may be too high and the impact resistance may be deteriorated.

The acrylic resin may be included in an amount of 5 to 15 parts by weight. When the content of the acrylic resin is less than 5 parts by weight, the hardness of the coating film is reduced, and when it is greater than 15 parts by weight, the appearance properties of the coating film may be deteriorated.

First acrylic polyol resin

The first acrylic polyol resin is a component for improving adhesion to a substrate and surface properties of a coating film.

The first acrylic polyol resin may be prepared by radical solution polymerization of a monomer having a vinyl-type double bond, such as a monomer having an organic acid group, a monomer having a hydroxyl group, an aromatic non-functional monomer, or an aliphatic non-functional monomer, and a thermal decomposition initiator. have.

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

The monomer having the hydroxyl group is 2-hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and the like, and these They may be used alone or in combination.

The aromatic non-functional 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, etc., alone or A mixture may be used.

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 68% by weight or 55 to 65% by weight. When the solid content of the first acrylic polyol resin is less than 50% by weight, the appearance properties of the coating film may be deteriorated due to the low solid content, and when it is greater than 70% by weight, the first acrylic polyol resin has a thickening effect, resulting in workability during painting. may be lowered

The first acrylic polyol resin may have a hydroxyl value of 50 to 80 mgKOH/g, for example, 55 to 78 mgKOH/g or 60 to 75 mgKOH/g. When the hydroxyl value of the first acrylic polyol resin is less than 50 mgKOH/g, the degree of crosslinking of the coating film may decrease and thus water resistance may decrease, and when the hydroxyl value exceeds 80 mgKOH/g, the hardness of the coating film becomes too high, resulting in deterioration in high-pressure car washability. It can be.

The weight average molecular weight of the first acrylic polyol resin may be 8,000 to 16,000 g/mol, for example, 10,000 to 14,000 g/mol. When the weight average molecular weight of the first acrylic polyol resin is less than 8,000 g/mol, adhesion of the coating film may deteriorate, and when the weight average molecular weight exceeds 16,000 g/mol, painting workability may deteriorate.

The first acrylic polyol resin may have a glass transition temperature (Tg) of 0 °C to 20 °C, for example, 5 °C to 15 °C. When the glass transition temperature of the first acrylic polyol resin is less than 0°C, the hardness of the coating film may decrease, and when the glass transition temperature exceeds 20°C, painting workability may decrease.

The first acrylic polyol resin may be included in 25 to 50 parts by weight, for example, 25 to 48 parts by weight or 30 to 45 parts by weight based on 5 to 15 parts by weight of the acrylic resin. When the content of the first acrylic polyol resin is less than 25 parts by weight, adhesion of the coating film may be deteriorated, and when it is greater than 50 parts by weight, the appearance characteristics of the coating film may be deteriorated.

Second acrylic polyol resin

The second acrylic polyol resin is a component for improving the appearance and surface properties of a coating film, and may be prepared in the same way as the first acrylic polyol resin.

The second acrylic polyol resin may have a solid content of 40 to 60% by weight, for example, 42 to 58% by weight or 45 to 55% by weight. When the solid content of the second acrylic polyol resin is less than 40% by weight, appearance characteristics may deteriorate due to the low solid content, and when it exceeds 60% by weight, the hardness of the coating film may increase and cracks may occur.

The second acrylic polyol resin may have a hydroxyl value of 40 to 110 mgKOH/g, for example, 45 to 105 mgKOH/g or 50 to 100 mgKOH/g. If the hydroxyl value of the second acrylic polyol resin is less than 40 mgKOH / g, the crosslinking density of the coating film may be reduced, resulting in poor water resistance and weather resistance. can

The second acrylic polyol resin may have a weight average molecular weight of 10,000 to 35,000 g/mol, for example, 15,000 to 28,000 g/mol. When the weight average molecular weight of the second acrylic polyol resin is less than 10,000 g/mol, adhesion of the coating film may deteriorate, and when the weight average molecular weight exceeds 35,000 g/mol, painting workability may deteriorate .

The second acrylic polyol resin may have a glass transition temperature of 15 to 70 °C, for example, 17 to 65 °C or 20 to 60 °C. When the glass transition temperature of the second acrylic polyol resin is less than 15° C., the coating film becomes soft and hardness may be defective, and when the glass transition temperature exceeds 70° C., the appearance characteristics of the coating film may be deteriorated.

The second acrylic polyol resin may be included in 20 to 45 parts by weight, for example, 22 to 45 parts by weight or 25 to 45 parts by weight based on 5 to 15 parts by weight of the acrylic resin. When the content of the second acrylic polyol resin is less than 20 parts by weight, the surface properties of the coating film may be deteriorated, and when it is greater than 45 parts by weight, the hardness of the coating film is reduced and high-pressure car washability may be deteriorated.

primary solvent

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

Solvents commonly used in primer coating compositions may be used as the first solvent, and non-polar solvents such as n-heptane, toluene, xylene, petroleum compounds and n-hexane, ethyl acetate, n-butyl acetate, iso Butyl acetate, ethylene glycol monoethyl ether acetate, dibasic esters, 3-methoxy butyl acetate, amyl acetate, butyl glycol acetate, methyl ethyl ketone, methyl isobutyl ketone, acetone, diisobutyl ketone, isophorone and cyclohexanone Such polar solvents may be used alone or in combination with each other.

The first solvent may be included in an amount of 10 to 30 parts by weight based on 5 to 15 parts by weight of the acrylic resin. If the content of the first solvent is less than 10 parts by weight, workability may deteriorate, and if it exceeds 30 parts by weight, adhesion or durability of the coating film may deteriorate due to excessive use of the solvent.

In particular, when the first solvent as described above is a mixed solvent, an ester-based solvent and a hydrocarbon-based solvent may be included. In this case, the ester-based solvent may be included in an amount of 10 to 20 parts by weight, and the hydrocarbon-based solvent may be included in an amount of 1 to 10 parts by weight.

<Clear coat coating composition>

The clear coat paint composition included in the paint kit for hot-stamped metal materials of the present invention is a paint composition capable of forming a clear coat layer by being coated on a primer layer formed by painting the primer paint composition, thereby As for improving appearance and durability, it may be a two-component coating composition containing a resin part and a curing agent part.

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

Third acrylic polyol resin

The third acrylic polyol resin is a component for improving the appearance and surface properties of a coating film, and may be the same as the first acrylic polyol resin or the second acrylic polyol resin used in the primer coating composition.

The third acrylic polyol resin used in the clear coat paint composition may be included in an amount of 10 to 50 parts by weight, for example, 15 to 45 parts by weight or 20 to 40 parts by weight. When the content of the third acrylic polyol resin is less than 10 parts by weight, the surface properties of the coating film may be deteriorated, and when it is greater than 50 parts by weight, the hardness of the coating film may be reduced.

The fourth acrylic polyol resin

The fourth acrylic polyol resin is a component for improving the appearance and surface properties of a coating film, and may be prepared in the same way as the third acrylic polyol resin.

The fourth acrylic polyol resin may have a solid content of 55 to 80% by weight, for example, 57 to 75% by weight or 60 to 70% by weight. When the solid content of the fourth acrylic polyol resin is less than 55% by weight, the appearance of the coating film may be deteriorated, and when it is greater than 80% by weight, workability may be deteriorated due to high viscosity.

The fourth acrylic polyol resin may have a hydroxyl value of 90 to 160 mgKOH/g, for example, 95 to 155 mgKOH/g or 100 to 150 mgKOH/g. When the hydroxyl value of the fourth acrylic polyol resin is less than 90 mgKOH/g, water resistance may deteriorate, and when the hydroxyl value exceeds 160 mgKOH/g, raw material cost may increase.

The fourth acrylic polyol resin may have a weight average molecular weight of 5,000 to 15,000 g/mol, for example, 7,000 to 13,000 g/mol. When the weight average molecular weight of the fourth acrylic polyol resin is less than 5,000 g/mol, adhesion of the coating film may deteriorate, and when the weight average molecular weight exceeds 15,000 g/mol, painting workability may deteriorate.

The fourth acrylic polyol resin may have a glass transition temperature of 50 to 100 °C, for example, 55 to 95 °C or 60 to 90 °C. When the glass transition temperature of the fourth acrylic polyol resin is less than 50° C., the hardness of the coating film may be lowered, resulting in deterioration in packaging workability, and when the glass transition temperature exceeds 100° C., impact resistance may be degraded.

The fourth acrylic polyol resin may be included in an amount of 1 to 30 parts by weight, for example, 3 to 25 parts by weight or 5 to 20 parts by weight based on 10 to 50 parts by weight of the third acrylic polyol resin. If the content of the fourth acrylic polyol resin is less than 1 part by weight, the surface properties of the coating film may be deteriorated, and if it is more than 30 parts by weight, the hardness of the coating film may be reduced and the packaging workability of the product may be deteriorated.

polyester polyol resin

The polyester polyol resin is a component for improving lightening properties and surface properties of a coating film formed from the clear coat paint composition.

The polyester polyol resin may be prepared by a condensation reaction between a glycol monomer and a monomer having an acid group. As the glycol monomer, for example, neopentyl glycol, trimethylolpropane, diethylene glycol, triethylene glycol, 1,6-hexanediol, 1,4-butanediol, 1,4-cyclohexaneamitanol, etc. may be used. , As the monomer having the 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 polyester polyol resin may have a solid content of 50 to 90% by weight, for example, 55 to 85% by weight or 60 to 80% by weight. When the solid content of the polyester polyol resin is less than 50% by weight, appearance characteristics may deteriorate, and when the solid content exceeds 90% by weight, the hardness of the coating film may decrease.

The polyester polyol resin may have a hydroxyl value of 90 to 170 mgKOH/g, for example, 95 to 165 mgKOH/g or 100 to 160 mgKOH/g. When the hydroxyl value of the polyester polyol resin is less than 90 mgKOH/g, weather resistance may be deteriorated, and when the hydroxyl value is greater than 170 mgKOH/g, workability may be deteriorated.

The polyester polyol resin may have a weight average molecular weight of 4,000 to 15,000 g/mol, for example, 5,000 to 10,000 g/mol. When the weight average molecular weight of the polyester polyol resin is less than 4,000 g/mol, adhesion of the coating film may deteriorate, and when the weight average molecular weight exceeds 15,000 g/mol, the appearance properties of the coating film may deteriorate.

The polyester polyol resin may have a glass transition temperature of -20 to 30 °C, for example -15 to 25 °C or -10 to 20 °C. When the glass transition temperature of the polyester polyol resin is less than -20 ° C, the hardness of the coating film may be reduced, and when the glass transition temperature exceeds 30 ° C, appearance characteristics may be deteriorated.

The polyester polyol resin is included in an amount of 5 to 40 parts by weight, for example, 7 to 35 parts by weight or 10 to 30 parts by weight, based on 10 to 50 parts by weight of the third acrylic polyol resin used in the clear coat paint composition. can If the content of the polyester polyol resin is less than 5 parts by weight, the lightening property of the coating film may be reduced, and if it is more than 40 parts by weight, the hardness of the coating film may be reduced.

second solvent

The second solvent is a component for improving workability of the clear coat paint composition and maintaining the thickness of a coating film formed from the clear coat paint composition, and may be the same as the first solvent used in the primer paint composition.

The second solvent may be included in an amount of 10 to 40 parts by weight based on 10 to 50 parts by weight of the third acrylic polyol resin used in the clear coat paint composition. If the content of the second solvent is less than 10 parts by weight, workability may deteriorate, and if it exceeds 40 parts by weight, adhesion or durability of the coating film may deteriorate due to excessive use of the solvent.

In particular, when the second solvent as described above is a mixed solvent, an ester-based solvent and a hydrocarbon-based solvent may be included. In this case, the ester-based solvent may be included in an amount of 10 to 20 parts by weight, and the hydrocarbon-based solvent may be included in an amount of 1 to 20 parts by weight.

<The curing agent part of each composition>

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

The curing agent portion of each of the coating compositions cures the resin portion of each coating composition, and may include a polyisocyanate-based curing agent.

The isocyanate functional group of the polyisocyanate-based curing agent reacts with the hydroxyl group of the acrylic polyol resin to form a urethane bond. An example of the polyisocyanate-based curing agent is excellent in curing speed, adhesion, coating hardness, heat resistance, etc., and at least one selected from homopolymers and modified products of methylene diisocyanate, toluene diisocyanate, and xylene diisocyanate, which is inexpensive and used. In the case of using such polyisocyanate, it has excellent adhesion to various plastic molded products, moisture resistance, coating hardness, etc., and has advantages in terms of economy due to its relatively low price.

In addition, although relatively expensive, one or more of hexamethylene diisocyanate, isophorone diisocyanate, and modified products may be selected and used to prevent yellowing of the coating film.

The reaction ratio (NCO/OH) of the isocyanate and the acrylic polyol resin of the polyisocyanate curing agent and the hydroxyl group in the acrylic resin or polyester polyol resin may be 1.03 to 1.07, and when lower than the above range, the coating film such as hardness and water resistance Physical properties may be deteriorated, and when higher than the above range, coating film drying properties may be deteriorated.

The polyisocyanate curing agent may be diluted with an appropriate diluent to form a curing agent composition, then stored in a separate container and sufficiently stirred immediately before use. Here, the diluent may use a commonly used thinner for dilution, and the dilution rate of the polyisocyanate diluent is such that when the main mixture and the polyisocyanate diluent are mixed, the hydroxyl group of the resin and the isocyanate functional group of the curing agent are combined, so that the urethane reaction is equivalent to equivalent. It can be determined by calculation so that it can occur, and the mixing is preferably 1:0.9 to 1:1.2 based on the equivalence ratio. This is because when the mixing equivalence ratio is greater than 1:1.2, excessive isocyanate is generated, and when the ratio is less than 1:0.9, the curing degree is lowered.

<Additives of resin part or curing agent part of each composition>

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

The surface adjusting agent is a component for adjusting surface tension. The surface conditioner may use a compound commonly used in paint compositions, and may include, for example, a mixture of at least one selected from the group consisting of a polysiloxane-based surface conditioner and a non-silicone-based surface conditioner. The polysiloxane-based surface conditioner may include silicone oil, silicone-based surfactant, silicone-based synthetic lubricant, and the like, and the non-silicone-based surface conditioner that does not substantially contain silicon (Si) is lower alcohol, mineral oil, oleic acid, polypropylene glycol, glycerin Higher fatty acid esters, fluorine-containing surfactants, and the like are exemplified. The content of the surface conditioner is not particularly limited, but may be included in an amount of 0.1 to 1 part by weight based on a total of 100 parts by weight of each paint composition. When the content of the surface conditioner is less than 0.1 parts by weight, the appearance properties of the coating film are deteriorated, and when it is included in more than 1 part by weight, physical properties such as adhesion of the coating film may be deteriorated.

The curing accelerator is a component for accelerating the curing of the coating composition to shorten the drying and curing time of the coating film. 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 based on 100 parts by weight of each paint composition. When the content of the curing accelerator is less than 0.01 parts by weight, drying of the coating film and physical properties of the coating film may be reduced, and when it is included in an amount exceeding 1 part by weight, the appearance properties of the coating film and pot life may be reduced.

The ultraviolet absorber is a component for preventing surface defects and gloss loss of a coating film and increasing weather resistance. An example of the UV absorber is hydroxyphenyl benzotriazole. The amount of the UV absorber is not particularly limited, but may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of each paint composition. If the content of the UV absorber is less than 1 part by weight, a problem of lowering the weather resistance of the coating film may occur, and if it is included in more than 10 parts by weight, a problem of cost increase may occur.

The wetting agent is a component for improving the wettability and leveling properties of a coating film during painting by adjusting the surface tension of the coating composition, and the wetting agent may be a conventional wetting agent used for paints in the art. The content of the wetting agent is not particularly limited, but may be included in an amount of 0.5 to 3 parts by weight based on 100 parts by weight of each paint composition. When the content of the wetting agent is included out of the above range, wettability and leveling properties of the coating film may be deteriorated.

The antifoaming agent is a mixture of a lipophilic agent and polysiloxane, and is a component that improves the appearance characteristics of a coating film by destroying air bubbles generated during painting. The content of the antifoaming agent is not particularly limited, but may be included in an amount of 0.1 to 1.5 parts by weight based on 100 parts by weight of each paint composition. When the content of the antifoaming agent is included outside the above range, air bubbles may be generated during painting of the coating composition including the antifoaming agent, and thus the appearance characteristics of the coating film may be deteriorated.

The thickener is a component for controlling the viscosity of the paint composition and imparting thixotropic properties to prevent flow of the paint composition during painting, and the thickener may use a conventional thickener used in paints in the art. The content of the thickener is not particularly limited, but may be included in an amount of 0.1 to 1 part by weight based on a total of 100 parts by weight of each paint composition. When the content of the thickener is included out of the above range, it may be difficult to prevent flow during painting of the coating composition.

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

However, the following examples specifically illustrate the present invention, and the content of the present invention is not limited by the following examples.

[Examples and Comparative Examples]

Paint compositions of Examples and Comparative Examples were prepared according to the compositions of Tables 1 and 2 below.

Primer paint composition

The acrylic resin, the first acrylic polyol resin and the second acrylic polyol resin were placed in a container and mixed at low speed using a stirrer. Thereafter, an ultraviolet absorber, a surface conditioner, a curing accelerator, and a first solvent were added and stirred for 30 minutes, and the viscosity was adjusted to 59 to 65 KU by additionally using a solvent if necessary. Then, a primer coating composition was prepared by adding a polyisocyanate curing agent (HDI Trimer) to the mixture in an equivalence ratio of 1:1 based on the base:curing agent. The viscosity of the prepared paint composition was adjusted with a diluted thinner for 15 to 18 seconds (FORD CUP # 4).

clear coat paint composition

The third acrylic polyol resin, the fourth acrylic polyol resin, and the polyester polyol resin were put into a container and mixed at low speed using a stirrer. Thereafter, an ultraviolet absorber, a surface conditioner, a curing accelerator, and a second solvent were added and stirred for 30 minutes, and the viscosity was adjusted to 59 to 65 KU by additionally using a solvent if necessary. Then, a polyisocyanate curing agent (HDI Trimer) was added to the mixture in an equivalence ratio of 1:1 based on the base:curing agent to prepare a clear coat paint composition. The viscosity of the prepared paint composition was adjusted with a diluted thinner for 15 to 18 seconds (FORD CUP # 4).

(weight%) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 primer clear primer clear primer clear primer clear primer clear primer clear acrylic polyol resin 1-1 32 - 27 - - - - - - - - - 1-2 - - - - 42 - - - 27 - 42 - 1-3 - - - - - - 32 - - - - - Article 2-1 32 - 37 - - - 32 - 37 - 22 - Article 2-2 - - - - 22 - - 22 - - - - Article 3-1 - 27 - 22 - 27 - - - - - - Article 3-2 - - - - - - - - - 17 - 30 Article 4-1 - 14 - 14 - - - - - - - - Article 4-2 - - - - - 14 - - - 17 - - Article 4-3 - - - - - - - 14 - - - 16 acrylic resin 1-1 9 - - - - 9 - - - - - 1-2 - - 9 - - - - - - - 13 - 1-3 - - - - 13 - - - 9 - - - polyester polyol resin 1-1 - 22 - 27 - 22 - 23 - - - - 1-2 - - - - - - - - - 29 - - 1-3 - - - - - - - - - - - 20 UV absorber 3 1.5 3 1.5 3 1.5 3 1.5 3 1.5 3 1.5 surface conditioner 0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 hardening accelerator 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 primary solvent 23.7 - 23.7 - 19.7 - 23.7 - 23.7 - 19.7 - second solvent - 34.6 - 34.6 - 34.6 - 38.6 - 34.6 - 31.6 Sum 100 100 100 100 100 100 100 100 100 100 100 100

(weight%) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 primer clear primer clear primer clear primer clear primer clear primer clear acrylic polyol resin 1-1 20 - 20 - 64 - - - - - - - 1-4 - - - - - - 32 - 27 - 32 - Article 2-1 49 - 49 - - - 32 - - - - - 2-3 - - - - - - - - 37 22 32 27 Article 3-1 - 27 - 20 - - - 27 - - - - Article 4-1 - 14 - 33 - 41 - 14 - 14 - 14 acrylic resin 1-1 4 - 4 - 9 - 9 - - - - - 1-4 - - - - - - - - 9 - 9 - polyester polyol resin 1-1 - 22 - 10 - 22 - - - 27 - - 1-4 - - - - - - - 22 - - - 22 UV absorber 3 1.5 3 1.5 3 1.5 3 1.5 3 1.5 3 1.5 surface conditioner 0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 0.2 0.8 hardening accelerator 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 primary solvent 23.7 - 23.7 - 23.7 - 23.7 - 23.7 - 23.7 - second solvent - 34.6 - 34.6 - 34.6 - 34.6 - 34.6 - 34.6 Sum 100 100 100 100 100 100 100 100 100 100 100 100

1-1 acrylic polyol resin: solid content 60% by weight, hydroxyl value 66mgKOH / g, weight average molecular weight 12,000 g / mol, glass transition temperature (Tg) 10 ℃

1-2 acrylic polyol resin: solid content 65% by weight, hydroxyl value 78mgKOH / g, weight average molecular weight 10,000 g / mol, glass transition temperature (Tg) 19 ℃

1-3 acrylic polyol resin: solid content 55% by weight, hydroxyl value 51mgKOH / g, weight average molecular weight 14,000 g / mol, glass transition temperature (Tg) 3 ℃

1-4 acrylic polyol resin: solid content 60% by weight, hydroxyl value 40mgKOH / g, weight average molecular weight 12,000 g / mol, glass transition temperature (Tg) 25 ℃

2-1 acrylic polyol resin: solid content 51% by weight, hydroxyl value 66 mgKOH / g, weight average molecular weight 21,000 g / mol, glass transition temperature (Tg) 40 ℃

2-2 acrylic polyol resin: solid content 45% by weight, hydroxyl value 108 mgKOH / g, weight average molecular weight 15,000 g / mol, glass transition temperature (Tg) 15 ℃

2-3 acrylic polyol resin: solid content 50% by weight, hydroxyl value 120 mgKOH / g, weight average molecular weight 17,000 g / mol, glass transition temperature (Tg) 10 ℃

3-1 acrylic polyol resin: solid content 50% by weight, hydroxyl value 70 mgKOH / g, weight average molecular weight 20,000 g / mol, glass transition temperature (Tg) 42 ℃,

3-2 acrylic polyol resin: solid content 55% by weight, hydroxyl value 40 mgKOH / g, weight average molecular weight 23,000g / mol, glass transition temperature (Tg) 70 ℃

4-1 acrylic polyol resin: solid content 65% by weight, hydroxyl value 115mgKOH / g, weight average molecular weight 10,000g / mol, glass transition temperature (Tg) 70 ℃,

4-2 acrylic polyol resin: solid content 60% by weight, hydroxyl value 157mgKOH / g, weight average molecular weight 13,000g / mol, glass transition temperature (Tg) 51 ℃

4-3 acrylic polyol resin: solid content 70% by weight, hydroxyl value 90mgKOH / g, weight average molecular weight 8,000g / mol, glass transition temperature (Tg) 98 ℃

Acrylic resin 1-1: solid content 50% by weight, glass transition temperature (Tg) 95 ℃,

Acrylic resin 1-2: solid content 48% by weight, glass transition temperature (Tg) 71 ℃

Acrylic resin 1-3: solid content 48% by weight, glass transition temperature (Tg) 120 ℃

Acrylic resin 1-4: solid content 52% by weight, glass transition temperature (Tg) 60 ℃

Polyester polyol resin 1-1: Solid content 70% by weight, hydroxyl value 140mg KOH / g, weight average molecular weight: 7,500g / mol Glass transition temperature (Tg) 10 ℃,

Polyester polyol resin 1-2: Solid content 65% by weight, hydroxyl value 168mg KOH / g, weight average molecular weight: 5,100g / mol Glass transition temperature (Tg) 0 ℃

Polyester polyol resin 1-3: Solid content 75% by weight, hydroxyl value 91mg KOH / g, weight average molecular weight: 9,500g / mol Glass transition temperature (Tg) 18 ℃

Polyester polyol resin 1-4: Solid content 70% by weight, hydroxyl value 85mg KOH / g, weight average molecular weight: 4,500g / mol Glass transition temperature (Tg) -10 ℃

Surface conditioner: Polysiloxane surface conditioner (BYK306)

First solvent: ethyl acetate: AROMATIC 100: AROMATIC 150= 8:1.5:1

Second solvent: ethyl acetate: AROMATIC 150 = 3.5 : 1

UV absorber: Benzotriazole

Hardener: Dibutyltin dilaurate

[Experimental Example] - Evaluation of appearance and physical properties of coating film

After painting the primer coating composition (dry film thickness: 15 to 20 microns) obtained in the above Examples and Comparative Examples on the material (hot stamping), it was left at room temperature for 5 minutes. The clear coat coating composition (dry coating film thickness: 30 to 35 microns) obtained in Examples and Comparative Examples was applied thereon, and the final coating was cured with hot air at 80° C. for 30 minutes.

Workability during painting, appearance and physical properties of the final multilayer coating were measured as follows and evaluated according to the following evaluation criteria, and the results are shown in Tables 3 and 4 below.

<Evaluation Criteria>

◎-Excellent, ○-Good, △-Average, X-Poor,

1) Painting workability

A 30cm x 40cm thin plate was coated twice with 61 IWATA cases, and the degree of atomization of the paint during painting, the degree of smoothness, and the paint film thickness were compared.

2) Appearance

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

3) Adhesion

In accordance with the ASTM D3359 tape adhesion test method, the degree of peeling off after the tape adhesion test among 100 1 mm x 1 mm scales was observed.

4) Water resistance

After immersing the finished coating film in a 40 ° C thermostat for 10 days, an adhesion test and appearance evaluation were performed.

5) High pressure car washing

After spraying at a spray pressure of 6900 KPa, a spray distance of 100 mm, a spray angle of 45 degrees, and a spray time of 30 seconds, the appearance of the coating film was visually compared.

6) Weatherability

After exposure to the energy of 2500 kJ in a xenon weatherometer tester environment, the coating film appearance, color difference, and adhesion were compared.

7) Hardness

On the test piece, apply force using a standard pencil (pencil hardness 2B to HB) to draw a straight line about 5 cm, and then check the surface condition of the coating film.

8) Impact resistance

Using the weight drop tester of ISO6272-2 with the coating surface of the test piece facing up, a weight of 0.5 kgf is dropped from a height of 20 cm to give an impact to the coating surface and examine the state of the coating film.

Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Painting workability ◎ ◎ ○ ○ ○ ○ Exterior ◎ ◎ ◎ ◎ ○ ◎ adhesiveness ◎ ◎ ○ ◎ ○ ○ water resistance ◎ ◎ ◎ ○ ○ ○ high pressure car wash ◎ ◎ ○ ◎ ○ ○ weatherability ◎ ◎ ◎ ◎ ○ ◎ Hardness ◎ ◎ ○ ○ ◎ ○ impact resistance ◎ ◎ ○ ○ ○ ○

Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Painting workability ◎ △ ◎ △ △ ○ Exterior ◎ ○ △ ◎ ◎ ◎ adhesiveness △ △ ○ ○ ◎ ◎ water resistance ◎ ◎ △ ◎ ◎ ◎ high pressure car wash △ △ △ X △ X weatherability ◎ ◎ ○ ◎ X Hardness ◎ ◎ △ ◎ X X impact resistance ◎ ◎ △ ◎ ◎ ◎

As shown in Tables 3 and 4, the coating films prepared using the coating compositions of Examples 1 to 6 according to the present invention have excellent painting workability and appearance, as well as adhesion, water resistance, high-pressure car washability and weather resistance. While the physical properties were excellent, the coating films prepared using the coating compositions of Comparative Examples 1 to 6 had inferior physical properties such as painting workability, adhesion, water resistance, high-pressure car washability, and weather resistance.

Claims (7)

A resin part comprising 5 to 15 parts by weight of an acrylic resin, 25 to 50 parts by weight of a first acrylic polyol resin, 20 to 45 parts by weight of a second acrylic polyol resin, and 10 to 30 parts by weight of a first solvent; And a curing agent; Primer coating composition comprising a; and
A resin part comprising 10 to 50 parts by weight of a third acrylic polyol resin, 1 to 30 parts by weight of a fourth acrylic polyol resin, 5 to 40 parts by weight of a polyester polyol resin, and 10 to 40 parts by weight of a second solvent; and a curing agent;
A paint kit for a hot-stamped metal material comprising a clear coat paint composition comprising: The method of claim 1,
The primer coating composition,
The acrylic resin has a solid content of 40 to 60% by weight, a glass transition temperature of 70 to 120 ° C,
The first acrylic polyol resin has a solid content of 50 to 70% by weight, a hydroxyl value of 50 to 80 mgKOH / g, a weight average molecular weight of 8,000 to 16,000 g / mol, a glass transition temperature of 0 to 20 ° C,
The second acrylic polyol resin has a solid content of 40 to 60% by weight, a hydroxyl value of 40 to 110 mgKOH / g, a weight average molecular weight of 10,000 to 35,000 g / mol, and a glass transition temperature of 15 to 70 ° C. Paint kit for phosphorus hot-stamped metal materials. The method of claim 1,
The clear coat paint composition,
The solid content of the third acrylic polyol resin is 40 to 60% by weight, the hydroxyl value is 40 to 110 mgKOH / g, the weight average molecular weight is 10,000 to 35,000 g / mol, and the glass transition temperature is 15 to 70 ° C,
The solid content of the fourth acrylic polyol resin is 55 to 80% by weight, the hydroxyl value is 90 to 160 mgKOH / g, the weight average molecular weight is 5,000 to 15,000 g / mol, and the glass transition temperature is 50 to 100 ° C,
The polyester polyol resin has a solid content of 50 to 90% by weight, a hydroxyl value of 90 to 170 mgKOH / g, a weight average molecular weight of 4,000 to 15,000 g / mol, and a glass transition temperature of -20 to 30 ° C. Paint kit for phosphorus hot-stamped metal materials. The method of claim 1,
The primer paint composition and the clear coat paint composition further comprise 0.01 to 1 part by weight of a hardening accelerator, 0.1 to 1 part by weight of a surface conditioner, and 1 to 10 parts by weight of an ultraviolet absorber, respectively. The method of claim 4,
The surface conditioner comprises at least one selected from the group consisting of polysiloxane-based compounds and non-silicone-based compounds. The method of claim 1,
Wherein the first solvent and the second solvent include an ester-based solvent, an ether-based solvent, a hydrocarbon-based solvent, or a mixed solvent thereof, respectively. The method of claim 1,
The curing agent part is a paint kit for a hot-stamped metal material comprising a polyisocyanate-based curing agent.