KR101540689B1 - Transparent paint composition comprising acryl resin for hardener - Google Patents

Abstract

The present invention relates to a clear coating composition containing a polyol resin, more particularly a subject containing a polyol resin; And a curing agent containing an isocyanate group-containing acrylic resin, wherein the isocyanate group-containing acrylic resin comprises an acrylic monomer represented by the following formula (1) and a non-functional acrylic monomer. According to the present invention, physical properties such as scratch resistance and drying property are improved and a more stable transparent coating composition can be provided.

Clear paint, isocyanate, polyol, dryness, scratch resistance

Description

BACKGROUND ART [0002] Transparent paint compositions containing an acrylic resin as a curing agent

The present invention relates to a clear coating composition comprising an acrylic resin as a curing agent.

Conventionally, NC lacquers, alkyd enamels, acrylic lacquers, and the like have been used as transparent paints. However, such transparent paints are inferior in quality and have been significantly obliterated or used.

In recent years, a two-component acryl-isocyanate type polyurethane paint based on an acrylic resin as a main component and a non-yellowing polyisocyanate as a curing agent has been used as a main product. Research and new product development for improving the quality of such a clear paint This is proceeding steadily.

Recently, in order to reduce the influence of air pollution caused by the emission of volatile organic compounds (VOC) in relation to environmental problems, use of organic solvents has been reduced and high solidified resins However, there is a problem in that the above-mentioned highly solidified resin may delay the drying and affect workability and physical properties of the coating film.

Disclosure of Invention Technical Problem [8] The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a transparent resin composition containing acrylic resin as a curing agent in order to shorten the drying time and improve physical properties such as scratch resistance, It is an object of the present invention to provide a coating composition.

The present invention provides, as means for solving the above problems, a subject containing a polyol resin; And a curing agent containing an isocyanate group-containing acrylic resin, wherein the isocyanate group-containing acrylic resin comprises an acrylic monomer represented by the following formula (1) and a non-functional acrylic monomer.

In Formula 1,

R ₁ is a hydrogen atom or a methyl group,

R ₂ is a C ₂ to C ₁₂ alicyclic compound, a C ₂ to C ₁₂ aliphatic compound, or a C ₂ to C ₁₂ aromatic compound.

According to the transparent coating composition of the present invention, it is possible to improve the drying property of the highly solidified resin and to improve the drying property, thereby improving the drying property and improving the physical properties such as scratch resistance.

The present invention relates to a subject containing a polyol resin; And a curing agent containing an isocyanate group-containing acrylic resin, wherein the isocyanate group-containing acrylic resin comprises an acrylic monomer represented by the following formula (1) and a non-functional acrylic monomer.

[Chemical Formula 1]

In Formula 1,

R ₁ is a hydrogen atom or a methyl group,

R ₂ is a C ₂ to C ₁₂ alicyclic compound, a C ₂ to C ₁₂ aliphatic compound, or a C ₂ to C ₁₂ aromatic compound.

Hereinafter, the transparent coating composition of the present invention will be described in more detail.

As described above, the clear coating composition of the present invention comprises a subject containing a polyol resin; And a curing agent containing an isocyanate group-containing acrylic resin containing an acrylic monomer represented by the following formula (1) and a non-functional acrylic monomer.

Wherein the clear coating composition comprises 60 to 90 parts by weight of a subject; And 10 to 40 parts by weight of a curing agent.

When the content of the subject is less than 60 parts by weight, there is a problem that physical properties such as scratch resistance may be deteriorated. When the content exceeds 90 parts by weight, gelation may occur

The polyol resin is preferably at least one selected from the group consisting of an acrylic polyol, an epoxy polyol, a polycarbonate polyol, and a low molecular weight polyol having a weight average molecular weight of 1000 or less.

The polyol resin preferably has a solid content of 40 to 80 parts by weight and a weight average molecular weight of 1,000 to 50,000.

If the solid content exceeds 40 to 80 parts by weight, the drying time may be increased When the weight average molecular weight of the polyol resin is out of the range of 1,000 to 50,000, physical properties such as scratch resistance may be deteriorated.

The polyol resin preferably has a hydroxyl value of 50 to 600 mg-KOH / g and a glass transition temperature of -20 to 60 ° C.

If the hydroxyl value of the polyol resin is out of the range of 50 to 600 mg-KOH / g, the adhesion and the water resistance may be deteriorated. If the glass transition temperature is outside the range of -20 to 60 ° C, scratch resistance may be deteriorated.

Further, the subject may further include at least one member selected from the group consisting of a catalyst for controlling the curing rate, a catalyst for controlling the calcining temperature, an external conditioning agent and an ultraviolet absorber.

That is, in the present invention, the polyol resin may further include additives such as a catalyst for adjusting the curing rate or a catalyst for controlling the temperature for baking, a modifier for external appearance, or an ultraviolet absorber.

The catalyst for controlling the curing rate may be selected from the group consisting of dibutyltin dilaurate, triethylamine, diethylenetriamine, bismuth carboxylate and zirconium chelate, It is preferable that at least one is.

The curing rate controlling catalyst may be included in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the solid content of the transparent coating composition of the present invention.

When the catalyst for controlling the curing rate is contained in an amount of less than 0.001 part by weight based on 100 parts by weight of the solid content of the clear coating composition, there is a fear that the drying time is increased. If the catalyst is contained in an amount exceeding 5 parts by weight, .

The catalyst for controlling the calcining temperature may be an ammonium salt catalyst, a metal salt catalyst, an amine catalyst or a Lewis acid catalyst. The catalyst may be used in an amount of 0.01 to 5 wt% based on 100 wt% of the solid content of the clear coating composition. ≪ / RTI >

The appearance control agent may be a silicone surfactant and may be contained in an amount of 0.01 to 0.2 parts by weight based on 100 parts by weight of the solid content of the clear coating composition.

On the other hand, the ultraviolet absorber may be a Tinuvin series of Ciba and may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the solid content of the clear coating composition.

Such additives may be included in an amount of less than 10 parts by weight based on 100 parts by weight of the solid content of the transparent coating composition.

The above-mentioned subject may further include a solvent, which is used for controlling the viscosity of the coating material, and includes all solvents generally applicable to coating materials such as aromatic and aliphatic hydrocarbon solvents, And 30 to 60 parts by weight based on 100 parts by weight of the solid content.

However, the additive according to the present invention is not limited to the above exemplified materials and content ranges, and may include all additives for improving the physical properties of the transparent coating composition according to the present invention.

Next, the curing agent containing the isocyanate group-containing acrylic resin will be described.

As described above, the curing agent contains an isocyanate group-containing acrylic resin containing an acrylic monomer represented by the following formula (1) and a non-functional acrylic monomer.

[Chemical Formula 1]

In Formula 1,

R ₁ is a hydrogen atom or a methyl group,

R ₂ is a C ₂ to C ₁₂ alicyclic compound, a C ₂ to C ₁₂ aliphatic compound, or a C ₂ to C ₁₂ aromatic compound.

The acrylic monomer represented by Formula 1 is an acrylic monomer having an isocyanate group (NCO functional group), and may include all acrylic monomers having an isocyanate group and an acrylic structure, unless adversely affecting the physical properties required for the clearcoat , Preferably 2-isocyanatoethyl methacrylate or 2-isocyanatoethyl acrylate can be used.

In addition, non-functional acrylic monomers may also include all known non-functional acrylic monomers, and may include C ₁ to C ₁₂ alkyl (meth) acrylates, C ₃ to C from the group consisting of ₁₂ of the cycloalkyl (meth) acrylates and C ₆ to bicyclo-alkyl (meth) acrylates of C ₁₂ may be at least one selected.

More specifically, the non-functional acrylic monomer may be selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl And the like.

As described above, the isocyanate group-containing acrylic resin has the advantage of improving the scratch resistance of the coating film and shortening the drying time because it imparts elasticity to the cured coating film and has a large number of cured sites.

Such an isocyanate group-containing acrylic resin can be produced by a conventional polymerization method of an acrylic monomer. For example, the acrylic monomer and the non-functional monomer represented by the formula (1) are reacted at 80 to 180 ° C The isocyanate group-containing acrylic resin according to the present invention can be obtained.

Examples of the initiator that can be used to prepare the isocyanate group-containing acrylic resin according to the present invention include 2,2'-azobis (2-methylbutylonitrile), 2,2'-azobisisobutyronitrile, dibenzoyl peroxide Butyl peroxybenzoate, ditertiary butyl peroxide, tertiary butyl peroxy-2-ethyl hexanoate, tertiary butyl peroxyacetate, tertiary amyl peroxy-2-ethyl hexanoate, cumyl Hydroperoxide, dicumylperoxide, or tetramethylhydroperoxide, but the initiator that can be used in the present invention is not limited to those exemplified above.

The solvent which can be used for the reaction is not particularly limited as long as it does not adversely affect the reaction, but aromatic solvents such as toluene and xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, ethyl propyl ketone, Ketone solvents such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, isopropyl acetate, butyl acetate, methyl cellosolve acetate, cellosolve acetate, butyl cellosolve acetate, Ester solvents such as carbitol acetate, and alcohol solvents such as n-propanol, isopropanol, n-butanol, isobutanol, and tertiary butanol.

Also, the isocyanate group-containing acrylic resin may contain 5 to 80 parts by weight of the acrylic monomer represented by the general formula (1); And 20 to 95 parts by weight of a non-functional acrylic monomer.

When the amount of the acrylic monomer represented by the formula (1) is less than 5 parts by weight, there is a problem that the anti-hatching property can be reduced. When the acrylic monomer is contained in an amount exceeding 80 parts by weight, gelation may occur.

The isocyanate group-containing acrylic resin preferably has a solid content of 40 to 80 parts by weight and a weight average molecular weight of 1,000 to 50,000.

If the solid content exceeds 40 to 80 parts by weight, workability may be deteriorated.

When the weight average molecular weight is less than 1,000, there is a possibility that physical properties such as scratch resistance and drying property are lowered. When the weight average molecular weight is more than 50000, gelation may occur.

The isocyanate group-containing acrylic resin preferably has an NCO content of 0.5 to 30 parts by weight, and a glass transition temperature of -20 to 60 ° C, based on 100 parts by weight of the solid content.

When the content of the NCO is out of the range of 0.5 to 30 parts by weight based on 100 parts by weight of the solid content of the isocyanate group-containing acrylic resin, or when the glass transition temperature of the isocyanate group-containing acrylic resin is out of -20 to 60 ° C, There is a problem that adhesion may be deteriorated.

Here, the isocyanate group-containing acrylic resin may further include a vinyl-based monomer, and the vinyl-based monomer is preferably contained in an amount of 40 parts by weight or less. The vinyl-based monomer If it exceeds 40 parts by weight, physical properties such as scratch resistance of the isocyanate group-containing acrylic resin may be deteriorated.

The vinyl-based monomer is preferably at least one selected from the group consisting of styrene, -methylstyrene, vinyltoluene, and vinyl acetate.

In addition, the curing agent preferably further comprises a polyfunctional isocyanate.

The polyfunctional isocyanate is advantageous in that the viscosity can be lowered by being included in the curing agent.

The curing agent may be used by mixing 20 to 100 parts by weight of an isocyanate group-containing acrylic resin and 0 to 80 parts by weight of a polyfunctional isocyanate and mixing a suitable solvent with 50 parts by weight or less.

Further, the polyfunctional isocyanate is at least one selected from the group consisting of toluene diisocyanate, diphenol methane diisocyanate, crude methane diisocyanate, naphthylene diisocyanate, isophorone diisocyanate, hydrogene methane diisocyanate and hexamethylene diisocyanate .

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to those described in the following examples.

Synthesis Example 1: Preparation of polyol resin (A)

Necked flask equipped with a thermometer and a condenser was charged with 222.0 g of Cocosol # 100 and 28.0 g of xylene in a nitrogen atmosphere, and the temperature was raised to 160 ° C.

144.0 g of methyl methacrylate, 144.0 g of n-butyl methacrylate, 288.0 g of styrene, 35.0 g of acrylic acid, 294.0 g of hydroxyethyl acrylate and 145.0 g of ethylhexyl acrylate and 144.0 g of tertiary amyl peroxy-2 -Ethyl nucleosanoate (105.0 g) was added dropwise over 3 hours.

Subsequently, the mixture was maintained at 165 占 폚 for 2 hours, and then a mixed solution prepared by dissolving 2.1 g of initiator amyl peroxy-2-ethylnucleosanoate in 69.0 g of xylene was added dropwise over 10 minutes.

Next, the reaction was maintained for 1 hour and 30 minutes, then 35.0 g of xylene was introduced at 80 DEG C or lower, and then cooled to room temperature to obtain an acrylic polyol resin (A).

The obtained acrylic polyol resin (B) was a transparent resin having a weight average molecular weight of 4000, a hydroxyl value of 135.4 mg KOH / g, a solid content of 70.3% by weight, and a viscosity (Gardner viscosity) of Z1-Z2.

Comparative Synthetic Example

Desmodur N 3300 (HDI-based Polyisocyanate) from Bayer was used as the raw material (C) for the subject prepared according to the comparative synthesis example. Desmodur N 3300 is an isocyanurate type multifunctional isocyanate having an NCO content of 21.8 parts by weight based on 100 parts by weight of the solid content.

Synthesis Example 2: Preparation of isocyanate group-containing acrylic resin (B1)

250.0 g of butyl acetate was added to a four-necked flask equipped with a thermometer and a condenser under a nitrogen atmosphere, and the temperature was raised to 125 占 폚.

78.6 g of 2-isocyanatoethyl acrylate as a monomer, 570.5 g of methyl methacrylate, 217.0 g of ethylhexyl acrylate, 183.4 g of Desmodur N 3300 and 18.3 g of Desmodur N 3300 as a initiator and tertiary amyl peroxy-2-ethylhexanoate 77.1 g was added dropwise over 3 hours.

Then, the mixture was maintained at 130 캜 for 30 minutes, and then a mixed solution prepared by dissolving 2.1 g of tertiary amyl peroxy-2-ethylhexanoate in 69.0 g of butyl acetate was added dropwise over 10 minutes.

Subsequently, the reaction mixture was maintained for 1 hour and 30 minutes, and then 30.0 g of butyl acetate was added at 80 ° C or lower, followed by cooling to room temperature to obtain an isocyanate group-containing acrylic resin (B1).

The obtained isocyanate group-containing acrylic resin (B1) had a weight average molecular weight of 6,000, a solid content of 70.3% by weight, an NCO content of 7.44 parts by weight based on 100 parts by weight of the solid content, Resin.

Synthesis Example 3: Preparation of isocyanate group-containing acrylic resin (B2)

250.0 g of butyl acetate was added to a four-necked flask equipped with a thermometer and a condenser under a nitrogen atmosphere, and the temperature was raised to 125 占 폚.

78.6 g of 2-isocyanatoethyl acrylate, 539.5 g of methyl methacrylate, 195.5 g of ethylhexyl acrylate, 220.5 g of Desmodur N 3300 and 10.0 g of tertiary amyl peroxy-2-ethylhexanoate 105.0 g was added dropwise over 3 hours.

Then, the mixture was maintained at 130 캜 for 30 minutes, and then a mixed solution prepared by dissolving 2.1 g of tertiary amyl peroxy-2-ethylhexanoate in 69.0 g of butyl acetate was added dropwise over 10 minutes.

Subsequently, the mixture was maintained for 1 hour and 30 minutes, and 30.0 g of butyl acetate was added thereto at 80 DEG C or lower, followed by cooling to room temperature to obtain an isocyanate group-containing acrylic resin (B2).

The resulting isocyanate group-containing acrylic resin (B2) was a transparent resin having a weight average molecular weight of 7,500, a solid content of 70.3% by weight, an NCO content of 8.93 parts by weight, and a viscosity (Gardner viscosity)

Examples 1 and 2 and Comparative Example 1: Preparation of clear coating composition

As shown in Table 1 below, the resin of Synthesis Example 1 was mixed with a catalyst, an additive and a solvent to prepare a subject, and Curing agents 1, 2 and 3 were respectively prepared as shown in Table 2 below.

In the case of the curing agents 1 and 2, Desmodur N 3300 was mixed at a weight ratio of 3: 7 to each of the resins prepared in Synthesis Examples 2 and 3, and in the case of Curing Agent 3, the resin .

Thus prepared transparent coating compositions of Examples 1 and 2 and Comparative Example 1 were prepared by mixing the prepared themes and curing agents at an equivalent ratio of 1: 1 as shown in Table 3 below, and in Examples 1 and 2 and Comparative Example 1 Was applied to transparent paints used in automobile repair coatings as one of various fields in which transparent paints can be applied.

Raw material name subject The polyol resin (A) according to Synthesis Example 1 73.0 Catalyst-DBTBL (0.5% in MIBK) 8.5 UV absorber - Tinuvin 1130 1.4 Lightan Tablet - Tinuvin 292 0.7 Glycol ether acetate 2.0 Methyl isobutyl ketone 6.17 Ethoxyethyl propionate 8.23 Sum 100

※ Unit: Weight%

Hardener 1 Hardener 2 Hardener 3 Synthesis Example 2 (B1) 30 - - Synthesis Example 3 (B2) - 30 - Comparative Synthesis Example (C) 70 70 100 total 100 100 100

※ Unit: Weight%

Raw material name Example 1 Example 2 Comparative Example 1 subject 76.40 76.73 80.75 Hardener 1 23.60 - - Hardener 2 - 23.27 - Hardener 3 - - 19.25 total 100 100 100

※ Unit: Weight%

Experimental Example: Measurement of physical properties of the obtained clear coating composition

First, the clear coating composition prepared above was mixed and then coated on a 0.1 mm-thick tin plate specimen, which had been sanded and degreased, to have a coating thickness of about 35 μm using a heavy duty automobile repair coating material (KCC product UU-2727) Followed by curing at 60 DEG C for 20 minutes. Thereafter, the base paint (UT5900, manufactured by KCC) was sprayed to a thickness of about 25 mu m, and about 5 minutes later, the coating was coated with a transparent clearcoat mixed to a thickness of about 40 mu m, followed by curing at 60 DEG C in an oven.

As a result, the physical test results of the cured coating film specimen are shown in Table 4 below.

The method of measuring the physical properties is as follows.

- Viscosity: measured using Ford cup # 4 at 25 ° C.

- Pot life: Measures the viscosity which is twice the initial viscosity.

- Drying: After painting, carry out a touch test while drying in oven at 60 ℃, and visually check that fingerprints are formed on the coating film.

- Pencil Strength: MITSUBISHI Pencil measured by hardness.

- Scratch resistance: It was checked 20 times with ANTEK automatic car washer equipment after 20 repetitions.

Comparative Example 1 Example 1 Example 2 VOC (g / L) 393 394 393 Initial viscosity (sec) 18.7 23.2 19.3 Housework time 50 minutes 50 minutes 50 minutes Flash off 7 minutes 6 minutes 6 minutes Drying (60 ° C) 18 minutes 17 minutes 14 minutes Pencil Strength HB F F Gloss retention 70% 75% 78%

As shown in Table 4, in Examples 1 and 2, the initial viscosity was somewhat higher than that in Comparative Example 1. In addition, the drying time was shorter than that of Comparative Example 1, the strength was excellent, and the gloss retention was high.

Claims (14)

60 to 90 parts by weight of a subject containing at least one polyol resin selected from the group consisting of an acrylic polyol, an epoxy polyol, a polycarbonate polyol and a low molecular weight polyol having a weight average molecular weight of 1000 or less; And 10 to 40 parts by weight of a curing agent containing an isocyanate group-containing acrylic resin, The isocyanate group-containing acrylic resin is preferably an isocyanate group- 5 to 80 parts by weight of an acrylic monomer represented by the following formula (1); And (Meth) acrylate selected from the group consisting of C ₁ to C ₁₂ alkyl (meth) acrylates, C ₃ to C ₁₂ cycloalkyl (meth) acrylates and C ₆ to C ₁₂ bicycloalkyl 20 to 95 parts by weight of an acrylic monomer, Wherein the isocyanate group-containing acrylic resin has a solid content of 40 to 80 parts by weight and an NCO content of 0.5 to 30 parts by weight based on 100 parts by weight of the solid content; [Chemical Formula 1]

In Formula 1, R ₁ is a hydrogen atom or a methyl group, R ₂ is a C ₂ to C ₁₂ aliphatic compound. delete delete The method according to claim 1, Wherein the polyol resin has a solid content of 40 to 80 parts by weight and a weight average molecular weight of 1000 to 50,000. The method according to claim 1, Wherein the polyol resin has a hydroxyl value of 50 to 600 mg-KOH / g and a glass transition temperature of -20 to 60 ° C. The method according to claim 1, Wherein the subject further comprises at least one additive selected from the group consisting of a catalyst for controlling the curing rate, a catalyst for controlling the calcining temperature, an external modifier, an ultraviolet absorber, a modifier and a solvent. The method according to claim 6, Wherein the catalyst for controlling the curing rate is at least one selected from the group consisting of dibutyltin dilaurate, triethylamine, diethylenetriamine, bismuth carboxylate and zirconium chelate. The method according to claim 1, Wherein the acrylic monomer represented by the formula (1) is 2-isocyanatoethyl methacrylate or 2-isocyanatoethyl acrylate. The method according to claim 1, The non-functional acrylic monomer may be selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, isobornyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl Wherein the transparent coating composition is at least one transparent coating composition. delete The method according to claim 1, Wherein the isocyanate group-containing acrylic resin further comprises a vinyl-based monomer. 12. The method of claim 11, Wherein the vinyl-based monomer is at least one selected from the group consisting of styrene,? -Methylstyrene, vinyltoluene, and vinyl acetate. The method according to claim 1, Wherein the curing agent further comprises a polyfunctional isocyanate. 14. The method of claim 13, The polyfunctional isocyanate is at least one selected from the group consisting of toluene diisocyanate, diphenol methane diisocyanate, crude methane diisocyanate, naphthylene diisocyanate, isophorone diisocyanate, hydrogene methane diisocyanate, and hexamethylene diisocyanate .