KR101947240B1 - Coating composition - Google Patents

Abstract

The present invention relates to a coating composition applied on a plastic material.

Description

[0001] COATING COMPOSITION [0002]

The present invention relates to a coating composition applied to a plastic substrate.

As a method of imparting a sense of beauty to a molded article formed of a plastic material, there is a method of plating chromium (Cr). At this time, trivalent chromium, which can generate a dark mirror image with less occurrence of harmful substances, is used as chromium.

However, there is a problem that the chromium plating layer is oxidized and deteriorated in function over time. Accordingly, it is possible to apply the paint on the chromium plating layer to maintain its function. At this time, the paint used must have sufficient adhesion with the chromium plating layer, and the properties such as moisture resistance, heat resistance and high brightness can be obtained at a required level .

However, conventionally, when the paint is applied 1-2 times on the chromium plated layer, the physical properties can not be obtained satisfactorily, so that the coating has to be carried out three times or more, and it is difficult to obtain sufficient adhesion with the chromium plating layer .

Korean Patent Publication No. 1995-0018326

The present invention aims to provide a coating composition excellent in adhesion, moisture resistance, heat resistance and the like and having high brightness.

The present invention relates to a paint comprising: a main part comprising 5 to 10 parts by weight of a first acrylic polyol resin, 25 to 35 parts by weight of a second acrylic polyol resin, 7 to 9 parts by weight of a metallic pigment, and 50 to 60 parts by weight of a first solvent; And 30 to 40 parts by weight of a polyisocyanate and 60 to 70 parts by weight of a second solvent.

The first acrylic polyol resin may have a weight average molecular weight (Mw) of 10,000 to 23,000.

The first acrylic polyol resin may have an OH value of 35 to 60 mgKOH / g.

The first acrylic polyol resin may have a glass transition temperature of 25 to 50 캜.

The mixing ratio of the main portion and the curing agent portion may be a weight ratio of 100: 13 to 100: 33.

The subject matter may further include 0.8 to 4 parts by weight of at least one additive selected from the group consisting of waxes, anti-settling agents, ultraviolet stabilizers, defoaming agents, and coupling agents.

The coating composition of the present invention is excellent in physical properties such as adhesiveness, moisture resistance and heat resistance and can exhibit high brightness, and when it is applied to a plastic material (in particular, a chromium-plated plastic material) An excellent coated surface can be formed.

Hereinafter, the present invention will be described.

The coating composition of the present invention contains a subject portion to which a specific acrylic polyol resin is applied and optimizes the content of each component so that the coating film having excellent adhesiveness, moisture resistance, heat resistance and high brightness is coated on a plastic material A plastic material), which will be described in detail as follows.

The coating composition of the present invention comprises a main portion and a curing agent portion.

Wherein the main portion comprises, based on 100 parts by weight of the main portion, 5 to 10 parts by weight of the first acrylic polyol resin; 25 to 35 parts by weight of a second acrylic polyol resin; 7 to 9 parts by weight of a metallic pigment; And 50 to 60 parts by weight of the first solvent.

The first acrylic polyol resin serves to improve the adhesion of the coating film, moisture resistance, and the like. Such a first acrylic polyol resin may be obtained 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, an aliphatic non-functional monomer, etc. and a thermal decomposition initiator have.

Examples of the monomer having an organic acid group include acrylic acid, methacrylic acid, maleic acid, and an anhydride thereof, which may be used alone or in combination. Examples of the monomer having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxybutyl acrylate, hydroxypropyl methacrylate and caprolactone acrylate, May be used alone or in combination.

Examples of the aromatic non-functional monomer include styrene and vinyl toluene, which may be used alone or in combination.

Examples of the aliphatic non-functional monomer include methyl methacrylate, ethyl acrylate, ethyl methacrylate, isobutyl acrylate, n-butyl methacrylate, n-butyl acrylate and isopropyl methacrylate, May be used alone or in combination.

Examples of the reaction initiator used in the radical solution polymerization include benzoyl peroxide, azoisobutyronitrile, and t-butyl peroxy-2-ethylhexanoate, which may be used alone or in combination.

The first acrylic polyol resin may have a weight average molecular weight (Mw) of 10,000 to 23,000, an OH value of 35 to 60 mgKOH / g, and a glass transition temperature of 25 to 50 ° C . Further, the ratio of the solid content of the first acrylic polyol resin may be 50 to 65% by weight.

The content of the first acrylic polyol resin is 5 to 10 parts by weight based on 100 parts by weight of the main portion, thereby improving the adhesion of the coating composition.

The second acrylic polyol resin plays a role of enhancing adhesion, heat resistance, etc. of the coating film. The second acrylic polyol resin may have a weight average molecular weight (Mw) of 10,000 to 25,000, an OH value of 50 to 80 mgKOH / g, and a glass transition temperature of 30 to 45 ° C. In addition, the ratio of the solid content of the second acrylic polyol resin may be 50 to 65% by weight.

The content of the second acrylic polyol resin is 25 to 35 parts by weight based on 100 parts by weight of the main portion, thereby improving the adhesion property and heat resistance of the coating composition.

The metallic pigment plays a role of enhancing the brightness of a coating film while forming a coating film having a metal-like feel. Examples of such metal-based pigments include aluminum paste and the like. Considering the dispersibility, the aluminum paste may be prepared by mixing a first aluminum paste having an aluminum particle size of 9 to 12.5 占 퐉 and a second aluminum paste having an aluminum particle size of 13 to 20 占 퐉. At this time, the content of the first aluminum paste may be 2 to 3 parts by weight based on 100 parts by weight of the main part, and the content of the second aluminum paste may be 5 to 6 parts by weight based on 100 parts by weight of the main part.

The content of the metal-based pigment is 7 to 9 parts by weight based on 100 parts by weight of the main portion, and when the coating composition is painted, it shows a metallic texture and can improve the aesthetics, brightness and the like of the painted surface.

The first solvent serves to adjust the viscosity of the main portion. Such a first solvent may be an acetate solvent such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl acetate, or 3-methoxybutyl acetate; Ketone solvents such as diacetone alcohol, methyl ethyl ketone, cyclohexanone, or isophorone; Glycol ether solvents; Glycol ether esters solvents; Aromatic hydrocarbon solvents such as toluene, xylene and the like; Or a mixture thereof and the like.

The content of the first solvent is 50 to 60 parts by weight based on 100 parts by weight of the main portion, thereby improving the dryness and workability of the coating composition.

The subject part may further include 0.8 to 4 parts by weight of at least one additive selected from the group consisting of waxes, anti-settling agents, ultraviolet stabilizers, defoamers, and coupling agents to improve the physical properties of the composition.

The curing agent part may contain, based on 100 parts by weight of the curing agent part, 30 to 40 parts by weight of a polyisocyanate; And 60 to 70 parts by weight of the second solvent.

The polyisocyanate reacts with the first acrylic polyol resin and the second acrylic polyol resin to form a urethane bond. Examples of such polyisocyanates include hexamethylene diisocyanate (HDI), trimethyl-HDI (TMDI), 2-methylpentane-1,5-diisocyanate (MPDI), isophorone diisocyanate (IPDI), 1,4- (Isocyanatomethyl) norbornane (NBDI), 3 (4) -isocyanatomethyl-1-methylcyclohexyl isocyanate (IMCI), 4,4'- Bis (isocyanatocyclohexyl) methane (H12MDI), or a mixture thereof.

The content of the polyisocyanate is 30 to 40 parts by weight based on 100 parts by weight of the curing agent, thereby improving the curing reactivity of the coating composition.

The second solvent serves to control the viscosity of the curing agent. Such a second solvent may be an acetate solvent such as methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl acetate, or 3-methoxybutyl acetate; Ketone solvents such as diacetone alcohol, methyl ethyl ketone, cyclohexanone, or isophorone; Glycol ether solvents; Glycol ether esters solvents; Aromatic hydrocarbon solvents such as toluene, xylene and the like; Or a mixture thereof and the like.

The content of the second solvent is 60 to 70 parts by weight based on 100 parts by weight of the curing agent, thereby improving the drying properties and workability of the coating composition.

In the metallic coating composition of the present invention, the main portion and the curing agent may be mixed in a weight ratio of 100: 13 to 100: 33. If the mixing ratio of the main portion and the curing agent portion is out of the above range, the adhesion of the coating film may be lowered or the curing reactivity of the composition may be lowered.

The coating composition of the present invention is excellent in adhesion, moisture resistance, heat resistance, and can exhibit high brightness. Therefore, it is desirable to provide a chromium-plated stand in a field where such properties are required (for example, ), And the like. In addition, since the coating composition of the present invention is excellent in adhesion, it is possible to form a coating film excellent in adhesion to a workpiece only by one to two coating processes, and to improve the efficiency of the coating process.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example  1 to 6]

One) Topic section  Produce

A subject portion having the composition shown in the following Table 1 was prepared.

2) Hardener part  Produce

A curing agent part having the composition shown in the following Table 2 was prepared.

3) Preparation of Coating Composition

The topical portion and the curing agent portion were mixed in a weight ratio of 100: 13 to prepare a coating composition.

Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 The first acrylic
Polyol resin Resin 1
(Solid content: 60% by weight,
OH value: 45,
Tg: 32 ° C
Mw: 11,258) 7.5 7.5 7.5 7.5 5 10 Resin 2
(Solid content: 60% by weight,
OH value: 66,
Tg: 20 DEG C
Mw: 25,000) - - - - - - The second acrylic polyol resin Solid content: 60% by weight,
OH value: 66,
Tg: 37 DEG C,
Mw: 12,360 27.5 12.5 17.5 22.5 30 25 Metal-based pigment Aluminum paste
(Aliminum Paste) 7.5 7.5 7.5 7.5 7.5 7.5 additive Dibutyltin dilaurate
(DIBUTYLTIN DILAURATE) 0.15 0.15 0.15 0.15 0.15 0.15 Glycol dimercaptopropionate
(GLYCOL DIMERCAPTOPROPIONATE) 0.15 0.15 0.15 0.15 0.15 0.15 Synthetic wax (anti-settling) One One One One One One The first solvent Butyl acetate (BA) 16.2 31.2 26.2 21.2 16.2 16.2 Xylene 30 30 30 30 30 30 Toluene 10 10 10 10 10 10 Sum 100 100 100 100 100 100

Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polyiso
Cyanate HDI / HEXAMETHYLENE DIISOCYNATE 37 30 25 20 37 37 The second solvent Xylene 33 40 45 50 33 33 Propylene glycol monomethyl ether acetic acid (PMA) 30 30 30 30 30 30 Sum 100 100 100 100 100 100

[ Example  7 to 9]

One) Topic section  Produce

A subject portion having the composition shown in Table 3 below was prepared.

2) Hardener part  Produce

A curing agent part having the composition shown in the following Table 4 was prepared.

3) Preparation of Coating Composition

The main portion and the curing agent were mixed in a weight ratio of 100: 23 to prepare a coating composition.

Item Example 7 Example 8 Example 9 The first acrylic
Polyol resin Resin 1
(Solid content: 60% by weight,
OH value: 45,
Tg: 32 ° C
Mw: 11,258) 7.5 5 10 Resin 2
(Solid content: 60% by weight,
OH value: 66,
Tg: 20 DEG C
Mw: 25,000) - - - The second acrylic polyol resin Solid content: 60% by weight,
OH value: 66,
Tg: 37 DEG C,
Mw: 12,360 27.5 30 25 Metal-based pigment Aluminum paste
(Aliminum Paste) 7.5 7.5 7.5 additive Dibutyltin dilaurate
(DIBUTYLTIN DILAURATE) 0.15 0.15 0.15 Glycol dimercaptopropionate
(GLYCOL DIMERCAPTOPROPIONATE) 0.15 0.15 0.15 Synthetic wax (anti-settling) One One One The first solvent Butyl acetate (BA) 16.2 16.2 16.2 Xylene 30 30 30 Toluene 10 10 10 Sum 100 100 100

Item Example 7 Example 8 Example 9 Polyiso
Cyanate HDI / HEXAMETHYLENE DIISOCYNATE 37 37 37 The second solvent Xylene 33 33 33 Propylene glycol monomethyl ether acetic acid (PMA) 30 30 30 Sum 100 100 100

[ Example  10]

The same composition as in Example 7 was applied, except that the topical portion and the curing agent portion were mixed at a weight ratio of 100: 33 to prepare a coating composition.

[ Example  11]

The same composition as in Example 8 was applied, except that a paint composition was prepared by mixing the main part and the hardener in a weight ratio of 100: 33.

[ Example  12]

The same composition as in Example 9 was applied, except that a paint composition was prepared by mixing the main part and the hardener in a weight ratio of 100: 33.

[ Comparative Example  1 to 5]

One) Topic section  Produce

A subject portion having the composition shown in Table 5 below was prepared.

2) Hardener part  Produce

A curing agent part having the composition shown in the following Table 6 was prepared.

3) Preparation of Coating Composition

The topical portion and the curing agent portion were mixed in a weight ratio of 100: 13 to prepare a coating composition.

Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 The first acrylic
Polyol resin Resin 1
(Solid content: 60% by weight,
OH value: 45,
Tg: 32 ° C
Mw: 11,258) 7.5 7.5 - 2 15 Resin 2
(Solid content: 60% by weight,
OH value: 66,
Tg: 20 DEG C
Mw: 25,000) 7.5 - 7.5 - - The second acrylic polyol resin Solid content: 60% by weight,
OH value: 66,
Tg: 37 DEG C,
Mw: 12,360 - 7.5 7.5 35 22 Metal-based pigment Aluminum paste
(Aliminum Paste) 7.5 7.5 7.5 7.5 7.5 additive Dibutyltin dilaurate
(DIBUTYLTIN DILAURATE) 0.15 0.15 0.15 0.15 0.15 Glycol dimercaptopropionate
(GLYCOL DIMERCAPTOPROPIONATE) 0.15 0.15 0.15 0.15 0.15 Synthetic wax (anti-settling) One One One One One 1st
solvent Butyl acetate (BA) 36.2 36.2 36.2 14.2 14.2 Xylene 30 30 30 30 30 Toluene 10 10 10 10 10 Sum 100 100 100 100 100

Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Polyiso
Cyanate HDI / HEXAMETHYLENE DIISOCYNATE 30 25 20 37 37 The second solvent Xylene 40 45 50 33 33 Propylene glycol monomethyl ether acetic acid (PMA) 30 30 30 30 30 Sum 100 100 100 100 100

[ Comparative Example  6]

The same composition as in Comparative Example 4 was applied, except that the topical portion and the curing agent portion were mixed in a weight ratio of 100: 23 to prepare a coating composition.

[ Comparative Example  7]

The same composition as in Comparative Example 5 was applied, except that the topical portion and the hardener portion were mixed in a weight ratio of 100: 23 to prepare a coating composition.

[ Comparative Example  8]

The same composition as in Comparative Example 4 was applied, except that the topical portion and the curing agent portion were mixed in a weight ratio of 100: 33 to prepare a coating composition.

[ Comparative Example  9]

The same composition as in Comparative Example 5 was applied, except that the topical portion and the curing agent portion were mixed in a weight ratio of 100: 33 to prepare a coating composition.

[ Manufacturing example  1 to 12 and Comparative Manufacturing Example  1 to 9]

Each of the compositions prepared in Examples 1 to 12 and Comparative Examples 1 to 9 was forcibly dried at 120 캜 (based on the material surface temperature) for 50 minutes to form a film.

[ Experimental Example ]

Physical properties of the prepared coating films were evaluated as follows, and the results are shown in Tables 7 to 10 below.

1. Color: Measured with a colorimeter (DE? 0.5:?, 0.5? DE? 1:?, 1? DE? 1.5:?, DE> 1.5:

2. Storage stability: The composition was evaluated after standing for 4 weeks in an oven at 40 占 폚 (when 5 volume% or less of the total volume of the composition was precipitated:? / 5 to 10 volume% ? / 10 to 15% by volume of the total volume of the composition was precipitated? / 15% or more of the total volume of the composition was precipitated.

3. Gloss: Measured with a gloss meter (measured value ≥90%: ◎ / 90%> measured value ≥85%: ∘ / 85%> measured value ≥ 80%: △ / ×).

4. Salt resistance: The coating film was sprayed with a 5% solution of NaCl at 30-40 ° C for 8 hours and allowed to stand for 16 hours. After the water was removed by a cotton swab, the mixture was allowed to stand for 30 minutes and subjected to a cross cutting test. (Adhesive 5B: ⊚ / Adhesive 4B: O / Adhesive 3B: ).

5. Hot water resistance: The coated film was eroded for 30 minutes in a constant-temperature and constant-humidity chamber at 60 ° C, and then allowed to stand for 2 hours and subjected to a cross cutting test. (Adherence 5B: Attachment 3B:? / Attachment 2B:?).

Production Example 1 Production Example 2 Production Example 3 Production Example 4 Production Example 5 Production Example 6 color ◎ ○ ○ ○ ○ ○ Storage stability ◎ ◎ ◎ ◎ ◎ ◎ Polish ◎ ○ ○ ○ ○ ○ Saltwater ◎ ◎ ◎ ◎ ◎ ○ My hot water castle ◎ ◎ ◎ ◎ ◎ ○ ?: Excellent,?: Good,?: Fair, X: Bad

Production Example 7 Production Example 8 Production Example 9 Production Example 10 Production Example 11 Production Example 12 color ◎ ○ ○ ◎ ○ ○ Storage stability ◎ ◎ ◎ ◎ ◎ ◎ Polish ◎ ○ ○ ◎ ○ ○ Saltwater ◎ ◎ ○ ◎ ◎ ○ My hot water castle ◎ ◎ ○ ◎ ◎ ○ ?: Excellent,?: Good,?: Fair, X: Bad

compare
Production Example 1 compare
Production Example 2 compare
Production Example 3 compare
Production Example 4 compare
Production Example 5 compare
Production Example 6 compare
Production Example 7 color × × × × × × × Storage stability ◎ ◎ ◎ ◎ ◎ ◎ ◎ Polish × × × × × × × Saltwater × △ × × △ × △ My hot water castle × △ × × △ × △ ?: Excellent,?: Good,?: Fair, X: Bad

compare
Production Example 8 compare
Production Example 9 color × × Storage stability ◎ ◎ Polish × × Saltwater × △ My hot water castle × △ ?: Excellent,?: Good,?: Fair, X: Bad

Referring to Tables 7 to 10, it can be confirmed that the coating composition of the present invention has excellent overall physical properties.

Claims (6)

5 to 10 parts by weight of a first acrylic polyol resin, 25 to 35 parts by weight of a second acrylic polyol resin, 7 to 9 parts by weight of a metallic pigment, and 50 to 60 parts by weight of a first solvent; And
30 to 40 parts by weight of a polyisocyanate, and 60 to 70 parts by weight of a second solvent,
And the second acrylic polyol resin has a hydroxyl value of less than 80 mgKOH / g and a glass transition temperature of more than 30 ° C. The method according to claim 1,
Wherein the first acrylic polyol resin has a weight average molecular weight (Mw) of 10,000 to 23,000. The method according to claim 1,
Wherein the first acrylic polyol resin has an OH value of 35 to 60 mgKOH / g. The method according to claim 1,
Wherein the first acrylic polyol resin has a glass transition temperature of 25 to 50 占 폚. The method according to claim 1,
Wherein the mixing ratio of the main portion to the curing agent portion is 100: 13 to 100: 33. The method according to claim 1,
Further comprising 0.8 to 4 parts by weight of at least one additive selected from the group consisting of waxes, anti-settling agents, ultraviolet stabilizers, antifoaming agents and coupling agents.