KR101329338B1 - Resin Composition for Transparent Varnich and Transparent Varnish Composition using the Same - Google Patents

Abstract

The present invention relates to a transparent paint, the resin composition for transparent paint according to the present invention is a first acrylic resin having an acrylic monomer having a bifunctional or more than one hydroxyl group as a monomer; A second acrylic resin having a higher glass transition temperature than the first acrylic resin and having an acrylic monomer having a bifunctional or higher hydroxyl group as a monomer; solvent; And an additive, wherein the weight ratio of the first acrylic resin and the second acrylic resin is 3: 1 to 1: 1.

Description

Resin composition for transparent paint and transparent paint composition using same {Resin Composition for Transparent Varnich and Transparent Varnish Composition using the Same}

The present invention relates to a resin composition for transparent paint, and a transparent paint composition using the same.

In general, in the case of the urethane transparent paint used as a transparent paint for home use, polyisocyanate is used as an acrylic resin and a curing agent.

However, in the case of forming a dry coating film, conventional transparent paints have a disadvantage in that appearance and weather resistance worsen when emphasis is placed on dryness, and workability (sanding and polishing) becomes weak when emphasis on appearance or leveling properties. It was.

In addition, there is a problem that the weather resistance is weak or the fluctuation range is large by using only one of the ultraviolet stabilizer or the ultraviolet absorber as the ultraviolet additive.

The present invention has been made to solve the above problems, the present invention is specifically blended with acrylic resin, using a UV additive, a curing catalyst, and a retardant as an additive, weather resistance and excellent workability (sanding and polishing) at the same time And it aims to provide a resin composition for transparent paint and a transparent paint composition having physical properties.

According to an aspect of the present invention,

1st acrylic resin which uses the acryl monomer which has a bifunctional or more than one hydroxyl group as a monomer;

A second acrylic resin having a higher glass transition temperature than the first acrylic resin and having an acrylic monomer having a bifunctional or higher hydroxyl group as a monomer;

solvent; And

Contains additives,

The weight ratio of the first acrylic resin and the second acrylic resin provides a resin composition for the transparent paint is 3: 1 to 1: 1.

At this time, the additives preferably include an ultraviolet additive, a curing catalyst, and a retarder.

In addition, it is preferable that the UV additive comprises a UV stabilizer and a UV absorber in combination.

The first acrylic resin has a solid content of 40 to 80%, a weight average molecular weight of 5000 to 20000, a hydroxyl value of 80 to 180, an acid value of 10 to 30, and a glass transition temperature (Tg) of 30 to 70 ° C and 25 ° C. It is preferable that it is an acrylic resin of viscosity Z2-Z5.

In addition, the second acrylic resin has a solid content of 40 to 80%, a weight average molecular weight of 5000 to 20000, a hydroxyl value of 80 to 180, an acid value of 5 to 30, the glass transition temperature (Tg) 40 ~ 80 ℃, 25 ℃ It is preferable that they are viscosity Z2-Z4.

In addition, the curing catalyst is preferably using DBTDL (Dibutyl tin dilaulate).

In addition, it is preferable to use GDMP (GLYCOL-DIMERCAPTOPROPIONANTE).

In addition, the first acrylic resin is 40 to 50% by weight, the second acrylic resin is 15 to 30% by weight, the ultraviolet additive is preferably contained in 1 to 2% by weight, the solvent is contained in 20 to 40% by weight. .

Moreover, the 1st acrylic resin which uses the acryl monomer which has a bifunctional or more hydroxyl group as a monomer,

A second acrylic resin having a glass transition temperature higher than that of the first acrylic resin and having an acrylic monomer having a bifunctional or higher hydroxyl group as a monomer;

Solvents, and

Resin composition for transparent paint containing an additive; And

Isocyanate-based curing agent for curing the resin composition for the transparent paint,

The weight ratio of the first acrylic resin and the second acrylic resin is 3: 1 to 1: 1,

The hydroxyl group of the first acrylic resin and the second acrylic resin and the isocyanate group of the curing agent are preferably 1: 0.9 to 1: 1.2 based on the equivalent ratio.

In addition, the curing agent preferably has a solid content of 80 to 100% by weight, and has an NCO value of 17 to 23%. .

In the resin composition for transparent coating of the present invention, the acrylic resin forms a dense and rigid coating film, thereby increasing the adhesive strength with the urethane formed on the coating layer, and excellent sanding and polishing properties.

In addition, UV additives, curing catalysts, retardants, and curing agents, which are additives, may be used together with the above-described resins to improve physical properties such as pencil hardness, wear resistance, and adhesion, and weather resistance.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is defined solely by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise stated.

Throughout the description and claims, unless the context requires otherwise, the word "comprise" is intended to include the stated article, step or group of articles, and steps; It is not meant to exclude an object, step or group of objects or a group of steps.

On the contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. In particular, any feature that is indicated to be advantageous or advantageous may be combined with any other feature or feature that is indicated to be advantageous or advantageous.

The resin composition for transparent paints according to one aspect of the present invention comprises a first acrylic resin, a second acrylic resin, a solvent, and an additive.

One. Acryl Polyol Resin

The acrylic resin according to the present invention includes a high weather resistant first acrylic resin and a second acrylic resin having a high glass transition temperature.

The first acrylic resin has a solid content of 40 to 80%, a weight average molecular weight of 5000 to 20000, a hydroxyl value of 80 to 180, an acid value of 10 to 30, and a glass transition temperature (Tg) of 30 to 70 ° C and 25 ° C. It is an acrylic resin of Z5 and has a strong weather resistance.

In one embodiment, the first acrylic resin includes (a) an acid value of 16 to 25 KOHmg / g, (b) a glass transition temperature of 64.5 ° C, and (c) 25 ° C of Gardner viscosity Z2 to Z5, (d) a weight average molecular weight of 8300 (e) It may have a property of 60% solids.

The second acrylic resin has a solid content of 40 to 80%, a weight average molecular weight of 5000 to 20000, a hydroxyl value of 80 to 180, an acid value of 5 to 30, and a glass transition temperature (Tg) of 40 to 80 ° C and 25 ° C. It is preferable that it is Z4 and a 2nd acrylic resin has a higher glass transition temperature than a 1st acrylic resin.

The second acrylic resin is, for example, (a) an acid value of 8 to 15 KOHmg / g, (b) a glass transition temperature of 71.6 ° C, (c) a Gardner viscosity of Z2 to Z4 at 25 ° C, and (d) a weight average molecular weight of 9100 (e Solids may be 65%.

The weight ratio of the first acrylic resin and the second acrylic resin is preferably 3: 1 to 1: 1. This is because when the ratio of the second acrylic resin is more than the ratio, the appearance is deteriorated, and when the second acrylic resin is smaller than the ratio, the hardness of the coating film is lowered.

On the other hand, the content of the first acrylic resin is 40 to 50% by weight of the resin composition for transparent paint, the content of the second acrylic resin is preferably 20 to 30% by weight of the resin composition for transparent paint.

On the other hand, the monomer used in the acrylic resin of the present invention is preferably 2-hydroxy (meth) acrylate, 2-hydroxy ethyl (meth) acrylate, 2-hydroxy propyl (meth) acrylate, 2-hydroxy Roxy butyl (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) Acrylic monomers having at least one hydroxyl group such as acrylate and mixtures thereof.

In addition, the acrylic monomer having at least one hydroxyl group may be selected from styrene, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, ethyl (meth) acrylate, and isobutyl (meth) acrylate. It may be copolymerized with the same monomer.

2. Solvent

The resin composition for transparent coatings of the present invention can use a common solvent used in the coating composition.

In the present invention, the solvent is preferably toluene (TOLUENE), xylene (XYLENE), butyl acetate (BUTYL ACETATE), ethyl acetate (ETHYL ACETATE), propylene glycol methyl ether acetate (DOWANOL PMA) or a mixture thereof may be used. . The resin composition for the transparent paint of the present invention preferably contains 20 to 40% by weight of the solvent, more preferably 25 to 35% by weight. If the solvent is contained in more than 40% by weight, not only the solid content of the paint is lowered, but also the viscosity of the paint can be lowered, and the yield can be lowered during coating.If the solvent is less than 20%, the raw material cost due to the increase of the content of the curing agent is increased.

This is because there is a rising problem.

3. Additive

The resin composition for the transparent paint of the present invention may include additional additives such as controlling the surface tension of the paint, or promoting curing.

(1) surface conditioner

Surface modifiers may be used additives commonly used in paint compositions to control the surface tension, for example from 0.05% to polyether-modified polysiloxane solution

0.1% can be used.

(2) curing catalyst

The curing catalyst may be included to promote curing of the paint, and may include, for example, about 0.01 wt% to about 0.1 wt% of DBTDL (Dibutyl tin dilaulate; dibutyl tin dilaurate).

(3) retardant

The retarder is for delaying pot life, and may include, for example, 0.05 wt% to 0.1 wt% of GLYCOL-DIMERCAPTOPROPIONANTE (GDMP).

If it exceeds 0.1%, there is a problem that the curing of the coating film becomes slow, and if it is less than 0.05%, the pot life is shortened.

At this time, the mixing ratio of the curing catalyst and the retarder can be determined experimentally within the above range to improve the curing properties and pot life.

(4) UV additives

UV additives are complex additives including ultraviolet absorbers and UV stabilizers.

UV absorbers are more resistant to UV radiation than chromophores of acrylic resins, which prevents the generation of radicals. It is effective in preventing discoloration, swelling, delamination and loss of gloss. For example, Hydroxyphenyl Benzotriazole may be included as 0.8% to 1.2%. If it exceeds 1.2%, the cost rises, and if it is less than 0.8%, there is a problem of deterioration of weather resistance.

UV stabilizers work in combination with the above-mentioned UV absorbers to treat polymer radicals generated by 100% UV blocking, and to prevent polymer degradation. For example, HALS (hindered amine light stabilizers) To 55%. If it exceeds 55%, unnecessary cost rise occurs, and if less than 45%, there is a problem in that the inhibition of photoacidification reaction is inferior.

At this time, the mixing ratio of the ultraviolet curing agent and the ultraviolet stabilizer can be determined experimentally within the above range.

The transparent coating composition according to another aspect of the present invention comprises a first acrylic resin, a second acrylic resin, a solvent, an additive, and a curing agent.

The transparent coating composition according to the present aspect is a two-component transparent coating composition used by mixing a curing agent to the resin composition for transparent coating described above.

The curing agent is to cure the resin composition for the transparent paint, the curing agent in the present invention uses 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. The polyisocyanate curing agent is preferably one having a solid content of 80 to 100% and an NCO value of 17 to 23%. One example of the polyisocyanate-based curing agent is hexamethylene diisocyanate excellent in yellowing resistance and light resistance.

The polyisocyanate-based curing agent may be diluted with a suitable solvent and stored in a separate container, followed by stirring sufficiently before use. The dilution rate of the polyisocyanate dilution solution can be determined by calculating the urethane reaction in equivalent weight equivalents by combining the hydroxyl and resin isocyanate functional groups of the resin when the main mixture and the polyisocyanate dilution solution are mixed. 1: 0.9-1: 1.2 are preferable. If it is greater than 1: 1.2, there is a problem that excess isocyanate is generated, and if less than 1: 0.9, there is a problem that the degree of curing is poor.

At this time, based on the volume of the curing agent compared to the resin composition for transparent paint 100: 26 ~ 34, if out of the ratio range, the coating film properties are lowered due to poor crosslinking.

In addition, the hardening mechanism of the coating composition of this invention is as follows.

R- (OH) n (acrylic resin having a hydroxyl group of 2 or more functionalities) + (O = C = N) n-R '(isocyanate curing agent of 2 or more functionalities)

 → R-(-NH-CO-) n-R '

(R is a hydrocarbon having an acrylic group, R 'is a methyl group and n is an integer greater than 1)

Example

The resin composition for transparent paints according to the present invention was prepared in the same ratio as in Table 1.

Example Example 1 Example 2 Example 3 First acrylic resin (1) 440 440 484 Second acrylic resin (2) 200 200 220 TOLUENE 60 60 60 DOWANOL PMA 70 70 62 ETHYL ACETATE 40 40 31 XYLENE 111.5 111.5 85 BUTYL ACETATE 36 36 36 Curing Catalyst (3) 0.3 0.3 0.3 XYLENE 1.8 1.8 1.8 UV absorbers (4) 12 14 17 BUTYL ACETATE 12 12 12 Surface conditioner (5) 0.8 0.8 0.8 BUTYL ACETATE 4.5 4.5 4.5 Retardant (6) 0.8 0.8 0.8 XYLENE 10.3 10.3 7.8 Sum 1,000 1,000 1,000

Comparative Example

Comparative Example was prepared as shown in Table 2. Comparative Example 1 and Comparative Example 2 did not include a retardant, Comparative Example 3 was prepared in the second acrylic resin is more content than the first acrylic resin.

Comparative Example Comparative Example 1 Comparative Example 2 Comparative Example 3 First acrylic resin (1) 240 240 440 Second acrylic resin (2) 400 400 200 TOLUENE 60 60 60 DOWANOL PMA 70 70 70 ETHYL ACETATE 40 40 40 XYLENE 123.6 124.5 124.5 BUTYL ACETATE 52.5 52.5 52.5 Curing Catalyst (3) 0.3 0.2 0.2 UV absorbers (4) 12 12 12 Surface conditioner (5) 0.8 0.8 0.8 Retardant (6) 0.8 0 0 Sum 1,000 1,000 1,000

In addition, using the same polyisocyanate (7) as a curing agent was mixed with the above-described embodiments of the resin composition for transparent paint to prepare a transparent paint composition.

(1) High Tg acrylic resin: weight average molecular weight 9100, hydroxyl value 113, acid value 8-15, Tg 71.6 ℃ (KCC Co., Ltd.)

(2) High weather resistant acrylic resin: weight average molecular weight 8300, hydroxyl value 119.8, acid value 16-25, Tg 64.5 ℃ (KCC Co., Ltd.)

(3) Curing catalyst: CATALYST PVC stabilizer (DBTDL) (Songwon Industrial Co., Ltd.)

(4) UV Additive: Tinuvin 5151 (manufactured by BASF Corporation)

(5) Surface conditioner: Tego glide b-1484 (EVNONIK DEGUSSA GMBH)

(6) Retardant: GLYCOL-DIMERCAPTOPROPIONANTE (THIO CHEMICAL)

(7) Polyisocyanate: Duranate PTA-90SB (ASAHI KASEI CHEMICALS CORP)

Experimental Example

Base coat (KCC product name UT578 (A): two-component urethane paint) was applied to the body (ABS specimen) at a thickness of 15 to 20㎛, and left at room temperature for 5 minutes, followed by the wet on wet method. The transparent coating composition was coated with a composition as shown in Table 1 at 30 μm, and left for 10 minutes, and thermally cured in an oven at 60 ° C. for about 30 minutes, and left at room temperature for 48 hours.

The physical properties of the transparent coating film thus obtained were measured as follows, and the results are shown in Table 2.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Coating appearance ◎ ◎ ◎ ◎ ◎ ◎ Adhesion ◎ ◎ ◎ ◎ ◎ ◎ Pencil hardness F F F F F F Water resistance ◎ ◎ ◎ ◎ ◎ ◎ Moisture resistance ◎ ◎ ◎ ◎ ◎ ◎ Acid resistance ◎ ◎ ◎ ◎ ◎ ◎ Alkali resistance ◎ ◎ ◎ ◎ ◎ ◎ Heat resistance ◎ ◎ ◎ ◎ ◎ ◎ Weatherability ○ ○ ○ ◎ ◎ ◎ Initial Curing Degree ○ ○ ◎ ◎ ◎ ◎ Sanding △ △ ◎ ◎ ◎ ◎

According to this, it can be seen that in Comparative Examples 1 and 2 without using a retardant, weather resistance and sanding resistance are insufficient, and in Comparative Example 3, weather resistance is somewhat insufficient.

In addition, the test method of each physical property at this time is as follows.

1) Appearance of the film: The projections and luster of the film surface were visually evaluated.

 ◎: Excellent, ○: Normal, △: Lack

2) Adhesiveness: Draw a perforation line with a cutter to reach the surface of the coating film, the size of 2mm * 2mm

100 square cells were made, adhere | attached on the surface with adhesive cellophane tape, and it dripped rapidly at 90 degrees, and evaluated the number of remaining coating films of squares.

◎: No peeling off scale

○: There is no peeling off the scale, but there is a small crack at the cut part

△: some scale peeling

×: There is peeling of many partial scales

3) Pencil Hardness: Place the pencil at an angle of 45˚ on the surface of the sample with a drawing pencil (MITSU-BISHI,), scrape at 0.5mm / sec speed with 1000g load, and erase the fine marks when erased with isopropyl alcohol (IPA). Evaluated

   (SOFT one direction) 3B-> 2B-> B-> HB-> F-> H-> 2H-> 3H (HARD direction)

4) Water resistance: After 240 hours of immersion in hot water at 40 ℃, it was left for 1 hour at room temperature, and then tested for appearance and adhesion.

(Double-circle): There is no peeling of the scale (appearance good)

(Circle): There is no peeling of scale, but there is a minute crack in the cut part (good appearance)

(Triangle | delta): There exists some scale peeling (appearance defect)

X: There is peeling of many partial scales (appearance defect)

5) Moisture resistance: After exposure to 168 hours in a chamber at 50 ° C. and a relative humidity of 98%, the resultant was left at room temperature for 1 hour and then subjected to an appearance and adhesion test.

(Double-circle): There is no peeling of the scale (appearance good)

(Circle): There is no peeling of scale, but there is a minute crack in the cut part (good appearance)

(Triangle | delta): There exists some scale peeling (appearance defect)

X: There is peeling of many partial scales (appearance defect)

6) Acid resistance: 0.2 ml of 0.1 N hydrochloric acid was dropped on the surface of the coating film, left at room temperature for 24 hours, washed with water, and then removed from the surface by air blow. Adhesion test was done.

(Double-circle): There is no peeling of the scale (appearance good)

(Circle): There is no peeling of scale, but there is a minute crack in the cut part (good appearance)

(Triangle | delta): There exists some scale peeling (appearance defect)

X: There is peeling of many partial scales (appearance defect)

7) Alkali resistance: 0.1N of sodium hydroxide is dropped on the surface of the coating film 0.2ml, left at room temperature for 24 hours, washed with water, air surface is removed by AIR BLOW, and left for 1 hour at sing Irradiation and adhesion tests were performed.

(Double-circle): There is no peeling of the scale (appearance good)

(Circle): There is no peeling of scale, but there is a minute crack in the cut part (good appearance)

(Triangle | delta): There exists some scale peeling (appearance defect)

X: There is peeling of many partial scales (appearance defect)

8) Heat-Cycle Resistance: CYCLE Condition (80 ± 2 ℃ × 3 h → Room temperature 1h → -40 ℃ × 3 h → Room temperature 1h

→ 50 ± 2 ° C., 95% RH × 7 ~ 15 h → room temperature 1h) After performing 5CYCLE, it was left at room temperature for 1 hour, and then the surface state of the coating film was examined and the adhesion test was carried out.

(Double-circle): There is no peeling of the scale (appearance good)

(Circle): There is no peeling of scale, but there is a minute crack in the cut part (good appearance)

(Triangle | delta): There exists some scale peeling (appearance defect)

X: There is peeling of many partial scales (appearance defect)

9) Initial Curing Degree: Leave at room temperature for 30 minutes after drying, tilt the sample surface at 45˚ with a drawing pencil (MITSU-BISHI,), scrape at a speed of 0.5mm / sec with 1000g load, and then isopropyl alcohol ( Fine marks were evaluated when erased with IPA)

          ◎: Excellent, ○: Normal, △: Lack

10) Sanding: After drying, the sand was left at room temperature for 30 minutes and sanded with sandpaper # 800 to evaluate the sanding properties.

          ◎: Excellent, ○: Normal, △: Lack

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

Claims (10)

As a transparent paint resin composition used in the two-component transparent coating composition for households in which the transparent paint resin composition and the isocyanate curing agent are separately stored,
The transparent paint resin composition,
Acrylic monomer having a bifunctional or higher hydroxyl group as a monomer, the solid content is 40 ~ 80%, the weight average molecular weight 5000 ~ 20000, the hydroxyl value 80 ~ 180, acid value 10 ~ 30, glass transition temperature (Tg) 30 ~ 70 ℃ A first acrylic resin having a Gardner viscosity of Z2 to Z5 at 25 ° C;
A glass monomer having a higher glass transition temperature than the first acrylic resin and having a bifunctional or higher hydroxyl group is a monomer, the solid content is 40 to 80%, the weight average molecular weight is 5000 to 20000, the hydroxyl value is 80 to 180, the acid value is 5 to 30, glass transition temperature (Tg) second acrylic resin having a Gardner viscosity Z2 to Z4 at 40 ~ 80 ℃, 25 ℃;
solvent; And
An additive having an ultraviolet stabilizer and an ultraviolet absorber,
The weight ratio of the first acrylic resin and the second acrylic resin is 3: 1 to 1: 1 resin composition for transparent paint.
The method of claim 1,
The additive is a resin composition for a transparent paint comprising a UV additive, a curing catalyst, and a retarder. delete delete delete 3. The method of claim 2,
The curing catalyst is a resin composition for transparent paint using DBTDL (Dibutyl tin dilaulate). 3. The method of claim 2,
The retardant is a resin composition for transparent paint using GDMP (GLYCOL-DIMERCAPTOPROPIONANTE). 3. The method of claim 2,
The first acrylic resin is 40 to 50% by weight, the second acrylic resin is 15 to 30% by weight, the ultraviolet additive is 1 to 2% by weight, the solvent is 20 to 40% by weight of the resin composition for the transparent coating composition . A transparent coating resin composition and a hardening agent are two-component transparent coating composition for home use,
The transparent paint resin composition,
The first acrylic resin has a solid content of 40 to 80%, a weight average molecular weight of 5000 to 20000, a hydroxyl value of 80 to 180, an acid value of 10 to 30, and a glass transition temperature. Tg) a first acrylic resin having a Gardner viscosity Z2 to Z5 at 30 to 70 ° C and 25 ° C;
A glass monomer having a higher glass transition temperature than the first acrylic resin and having a bifunctional or higher hydroxyl group is a monomer, the solid content is 40 to 80%, the weight average molecular weight is 5000 to 20000, the hydroxyl value is 80 to 180, the acid value is 5 to 30, glass transition temperature (Tg) second acrylic resin having a Gardner viscosity Z2 to Z4 at 40 ~ 80 ℃, 25 ℃;
solvent; And
An additive having an ultraviolet stabilizer and an ultraviolet absorber,
The weight ratio of the first acrylic resin and the second acrylic resin is 3: 1 to 1: 1,
The curing agent includes an isocyanate curing agent for curing the resin composition for the transparent paint,
The hydroxyl composition of the first acrylic resin and the second acrylic resin and the isocyanate group of the curing agent are 1: 0.9 to 1: 1.2 based on the equivalent ratio.


delete