KR20140085862A - Clear paint composition for rapid repairing and method of manufacturing paint film using the same - Google Patents

Abstract

Disclosed is a paint composition for repairing cars at super high speed. The paint composition comprises: 1) a first paint composition including 50-70 wt% of a two-packaged acrylic polyol resin, 0.05-2 wt% of a urethane reactive catalyst, 28-48 wt% of an organic solvent, 0.5-5 wt% of a surface modifier, and 0.5-5 wt% of a weather resistance enhancer; and 2) a second paint composition including 50-70 wt% of an isocianate compound, and 30-50 wt% of an organic solvent. The paint composition has enhanced hardening property at room temperature, thereby capable of being naturally hardened and being environmentally-friendly.

Description

TECHNICAL FIELD [0001] The present invention relates to a clear coating composition for ultra-fast repair and a method for forming a coating film using the clear coating composition. BACKGROUND ART < RTI ID = 0.0 >

TECHNICAL FIELD The present invention relates to a coating composition and a method for forming a coating film using the coating composition. More particularly, the present invention relates to a transparent coating composition for an ultra-fast repair which is excellent in curability at room temperature and can be cured naturally, and is environmentally friendly.

Development has been proceeding in view of the characteristics of appearance, drying and workability as important factors in the technique of producing a clear coating composition. Recently, much attention has been paid to the development of economical and environmentally friendly paints by reducing energy and minimizing CO ₂ gas. As a part of this research, many researches on natural curing type paints have been carried out.

In the case of a clear coating, it is usually subjected to heat treatment at a temperature of about 60 ° C for about 30 minutes, followed by cooling at room temperature for about 1 hour or more, and then the next polishing operation can be carried out. According to this process, a large amount of energy is consumed in the heat treatment and the operation takes a long time.

As a result, studies on transparent coatings capable of natural curing at room temperature have been continuing. It is required to produce a coating film which exhibits excellent appearance and does not cause problems such as lowering of gloss and lowering of drying property and which is easy to work and satisfactory and has excellent quality.

Accordingly, an object of the present invention is to provide an ultrafine clear coating composition which is excellent in natural curability and which can be dried at room temperature, is excellent in appearance and gloss, and is environmentally friendly.

Another object of the present invention is to provide a coating film forming method capable of reducing energy consumption and reducing the amount of generated carbon dioxide gas by using the above ultrafine transparent coating composition.

The transparent coating composition for realizing the object of the present invention comprises 50 to 70% by weight of a two-component type acrylic polyol resin, 0.05 to 2% by weight of a urethane reaction catalyst, 28 to 48% by weight of an organic solvent, 0.5 to 5% And 0.5 to 5% by weight of a weather resistance improver, 50 to 70% by weight of an isocyanate compound and 30 to 50% by weight of an organic solvent.

As an example, the clear coating composition may have a volatile organic solvent content of 460 to 560 g / l.

In one example, the two-pack type acrylic polyol resin comprises 10 to 40% by weight of a vinyl monomer having an aromatic group, 10 to 40% by weight of a vinyl monomer having a hydroxyl group, 1 to 10% by weight of a vinyl monomer having an organic acid group, And 10 to 40% by weight of a vinyl monomer. At this time, the two-part type acrylic polyol resin may have a number average molecular weight in the range of 6,000 to 10,000, an OH content in the range of 4 to 5% by weight on a solid basis, and a glass transition temperature in the range of 70 to 90 ° C.

As an example, the first coating composition and the second coating composition may be mixed so that the hydroxy equivalent weight in the first coating composition and the isocyanate equivalent in the second coating composition are in a ratio of 1: 0.9 to 1.1.

A method of forming a transparent coating film for achieving another object of the present invention is a method for forming a transparent coating film comprising 50 to 70% by weight of a two-component type acrylic polyol resin, 0.05 to 2% by weight of a urethane reaction catalyst, 28 to 48% by weight of an organic solvent, And a second coating composition comprising 50 to 70% by weight of an isocyanate compound and 30 to 50% by weight of an organic solvent, based on the total weight of the coating composition, And drying the applied coating composition to form a dried coating film, and polishing the dried coating film.

The ultra high-speed clear coating composition can rapidly perform urethane reaction at room temperature, and can finish the drying within about one hour at room temperature without heat treatment, and can perform subsequent work in a short time, and can form an environmentally friendly and excellent quality coating film.

Hereinafter, the present invention will be described in more detail. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are further described in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

In this application, the terms "comprises" or "having", etc. are intended to specify the presence of stated features, components, steps, processes, compositions, or combinations thereof in the specification, and not to limit the presence or addition of one or more other features or components, Steps, processes, compositions, or combinations thereof, which are not intended to be limiting.

Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, the present invention will be described in detail.

The ultrafine clear coating composition according to an embodiment of the present invention comprises 1) 2-pack type acrylic polyol resin 50-70 wt%, urethane reaction catalyst 0.05-2 wt%, organic solvent 28-48 wt%, surface modifier 0.1-3 wt% A second coating composition comprising 0.5 to 5 wt% of a weather resistance improver, and 2) 50 to 70 wt% of a hexamethylene diisocyanate trimer and 30 to 50 wt% of an organic solvent.

The two-pack type acrylic polyol resin comprises 10 to 40 wt% of a vinyl monomer having an aromatic group, 10 to 40 wt% of a vinyl monomer having a hydroxyl group, 1 to 10 wt% of a vinyl monomer having an organic acid group, By weight to 40% by weight.

Examples of the vinyl monomer having an aromatic group include styrene monomers, and examples of the vinyl monomer having a hydroxyl group include 2-hydroxy ethyl methacrylate and 2-hydroxy propyl acrylate. Examples of the vinyl monomer having an organic acid group include Meta acrylic acid and acrylic acid. Examples of the vinyl monomer having an aliphatic group include methyl methacrylate and butyl acrylate. When they are used in combination, they can promote the urethane reaction because they have a high Tg, an appropriate molecular weight and a high hydroxyl value.

Acrylic polyol resin is synthesized with n-butyl acetate as main axis for imparting flexibility of a coating film and has an average molecular weight of 6,000 to 10,000, an OH content of 4 to 5% by weight on a solid basis, a glass transition temperature of 70 to 90 Lt; 0 > C. When a resin satisfying these conditions is used, drying is quick and glossiness is good at room temperature.

The acrylic polyol resin is used in the range of 50 to 70% by weight based on the total amount of the first coating composition. If the amount is less than 50 wt%, it is undesirable to exceed the volatile organic compound (VOC) environmental standard, and if the amount is more than 70 wt%, it is not preferable because it does not meet the spray viscosity.

The urethane reaction catalyst may be added as a component to accelerate the urethane reaction, such as dibutyl tin dilaurate, zinc octoate, stannous octoate, dibutyl tin diacetate, dibutyl tin dimeride, triethyl diamine, triethylenethanol amine , 1,4-diazo cyclooctane, 2-dimethylaminoethyl, trimethylaminoethylethanolamine, pentamethyldiethylenetriamine, dimethylethanolamine, ethylmorphyrin, dimethylaminoethylmorpholine, dimethylcyclohexylamine and alkali metal At least one selected from the group consisting of carboxylates of carboxylic acids.

The urethane reaction catalyst is added in an amount of 0.05 to 2% by weight based on the total amount of the first coating composition. If the addition amount is less than 0.05% by weight, the function as a catalyst is insignificant. If the addition amount exceeds 2% by weight, the increase in the effect of the increase in content is insignificant, and there is no need to increase it.

As the organic solvent for the preparation of the first coating composition, ketones such as Acetate, Acetone, MIBK, DIBK, MAK and MIAK such as Butylacetate, PMA and Cellosolve acetate, and Aromatic such as Xylene, AROMATIC 150 and Kocosol 100 . And the amount thereof to be used is in the range of 28 to 48% by weight based on the total amount of the first coating composition. If the addition amount is less than 28% by weight, the viscosity increases and spraying becomes impossible. If the addition amount exceeds 48% by weight, the volatile organic compound (VOC) environment standard is exceeded, which is not preferable.

As the surface modifier, a silicone type, a fluorine type compound, an acrylic type compound and the like can be used. The amount of the pigment to be used is in the range of 0.1 to 3% by weight based on the total amount of the first coating composition. If the addition amount is less than 0.1% by weight, the surface modification effect becomes insufficient, which is undesirable. If the addition amount exceeds 3% by weight, repacking failure and running down may occur.

Examples of the weather resistance improver include ultraviolet absorbers (UVA) and ultraviolet stabilizers (HALS). The anti-weathering agent functions to prevent discoloration, gloss disappearance and cracking of the coating film. Particularly, ultraviolet absorbers prevent the discoloration of the coating film, and examples thereof include hydroxyphenylbenzotriazole, hydroxyphenyl-S-triazine, hydroxybenzophenone, and oxanilide. The ultraviolet stabilizer prevents gloss loss and cracking of the coating film, and examples thereof include tetramethylpiperidine compounds and the like. The amount of the pigment to be used is in the range of 0.5 to 5% by weight based on the total amount of the first coating composition. If the addition amount is less than 0.5% by weight, the effect of improving the weatherability is insignificant, and if the addition amount is more than 3% by weight, it affects the color, which is not preferable. The mixing ratio of the ultraviolet light absorber and the ultraviolet light stabilizer is not particularly limited, but is preferably 2: 1.

The second coating composition comprises an isocyanate compound and an organic solvent. The second coating composition is obtained by mixing 50 to 70% by weight of an isocyanate compound with 30 to 50% by weight of an organic solvent.

Examples of the isocyanate compound include hexamethylene diisocyanate trimer, tolylene diisocyanate, methylene phenyl diisocyanate, xylylene diisocyanate, and the like. The amount thereof is in the range of 50 to 70% by weight based on the total amount of the second coating composition. If the amount is less than 50% by weight, the OH: NCO equivalent ratio is not more than 1: 0.8, and if the amount is more than 70% by weight, the OH: NCO equivalent ratio is not more than 1: 1.3.

As the organic solvent for preparing the second coating composition, XYLENE, TOLUENE, Kocosol # 100 and the like may be used, which is in the range of 30 to 50% by weight based on the total amount of the second coating composition.

Wherein the first coating composition and the second coating composition are mixed to produce a clear coating composition, wherein the hydroxy equivalent weight in the first coating composition and the isocyanate equivalent in the second coating composition are mixed to be 1: 0.8 to 1.3 .

To the clear coating composition, commonly used additives such as a leveling control agent and a urethane catalyst may be added as needed.

The clear coating composition to be prepared has a volatile organic solvent content of 460 to 560 g / l, preferably 490 to 500 g / l, which is much lower than that of the conventional composition.

The transparent coating composition prepared as described above can be dried at a high speed because a curing reaction occurs at a sufficiently high speed at room temperature without heat treatment.

Hereinafter, a method for forming a coating film using the above-mentioned clear coating composition will be described.

In particular, the clear coating composition according to an embodiment of the present invention can be applied to the top processing step in the coating process for automobile repair. The steps to which the clear coating composition is applied will be described in more detail.

In order to repair a damaged part of an automobile, it is divided into a surface adjustment step, a middle processing step, and a top processing step.

The surface conditioning step includes a surface preparation step including the evaluation of the damaged area, the washing of the damaged area and the removal of foreign substances, the surface polishing and cleaning steps to fill the grooves or scratches of the damaged area and smooth the surface, , Putty polishing and cleaning steps, and the like.

The intermediate stage includes a masking step of a portion where coating is not required, a degreasing step of the intermediate coating portion, a primer-to-spacer intermediate coat application step to increase the corrosiveness and surface smoothness of the damaged portion, a middle coat paint drying step, a middle polishing and cleaning step .

The upper phase processing step includes a secondary masking step in which the upper coating is unnecessary, a color paint application step in which the colors are matched, a transparent paint application step in which gloss is imparted and durability is increased, and finally, a light for finishing the exterior surface And a step of betting and evaluation.

The transparent coating composition according to an embodiment of the present invention can be suitably applied to the transparent coating step in the top processing step. This part will be described in detail.

First, the transparent coating composition to be produced is applied onto the substrate. The substrate is, for example, a front fender of a car requiring repair. The necessary surface treatment and the intermediate treatment process are carried out and the basecoat color paint is applied as the top treatment process, and then the transparent paint composition is applied. The clear coating composition is sprayed several times, for example twice, so that the film thickness is about 40 to 60 mu m.

The applied coating composition is dried to form a dried coating film. The drying may be carried out at room temperature or higher for 0.5 to 1 hour at 20 DEG C or higher, or by irradiation with infrared rays. When infrared rays are irradiated, for example, irradiation is performed for about 10 minutes at a distance of about 70 cm from the coated film, the drying operation is completed. According to the present invention, it is possible to carry out subsequent operations such as a polishing operation and a detachable operation within about one hour at room temperature, compared with the conventional drying requiring about 30 minutes of heat treatment at about 60 ° C. It can be seen that it is saved.

Of course, in the embodiment of the present invention, the drying process may be performed by a heat treatment method. In this case, if it is heat-treated at 60 ° C, sufficient drying is possible within 10 minutes.

Thereafter, the dried coating film is polished. That is, the polishing operation is performed. Conventionally, when the coating film is dried by the heat treatment process at about 60 ° C for about 30 minutes, the coating process is performed after cooling the coating film at room temperature for about 1 hour or more. However, if the coating film is dried at room temperature as in the embodiment of the present invention, the polishing operation can be performed immediately after drying.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

≪ Example 1 >

Based on the total amount of the first coating composition, 56 wt% of two-component type acrylic polymer, 0.05 wt% of urethane reaction catalyst (dibutyl tin dilaurate), 0.5 wt% of zinc octoate, 41 wt% of organic solvent (XYLENE) 1% by weight of an ultraviolet light absorber (polysilicon), 1% by weight of (hydroxyphenylbenzotriazole) as an ultraviolet absorber and 0.5% by weight of an ultraviolet stabilizer (tetramethylpiperidine compound) were mixed to prepare a first coating composition.

Based on the total amount of the second coating material, 67 parts by weight of hexamethylene diisocyanate trimer and 33 parts by weight of xylene were mixed to prepare a second coating composition.

≪ Example 2 >

Based on the total amount of the first coating composition, 56 wt% of two-component type acrylic polymer, 0.05 wt% of urethane reaction catalyst (dibutyl tin dilaurate), 41 wt% of organic solvent (XYLENE), 1 wt% of surface modifier (polysilicon) , 1% by weight of an ultraviolet absorber (hydroxyphenylbenzotriazole) and 0.5% by weight of an ultraviolet stabilizer (tetramethylpiperidine compound) were mixed to prepare a first coating composition.

Based on the total amount of the second coating composition, 65 wt% of hexamethylene diisocyanate trimer and 35 wt% of xylene were mixed to prepare a second coating composition.

≪ Comparative Example 1 &

(1) by weight based on the total amount of the first coating composition, 70% by weight of a two-component type acrylic polymer, 0.05% by weight of a urethane reaction catalyst (dibutyltin dilaurate), 41% by weight of an organic solvent (XYLENE) , 1% by weight of an ultraviolet absorber (hydroxyphenylbenzotriazole) and 0.5% by weight of an ultraviolet stabilizer (tetramethylpiperidine compound) were mixed to prepare a first coating composition.

39% by weight of hexamethylene diisocyanate trimer and 61% by weight of xylene were mixed based on the total amount of the second coating composition to prepare a second coating composition.

Each of the first and second coating compositions prepared in Examples 1 and 2 was mixed at a volume ratio of 4: 1 to prepare a clear coating composition. Also, the first and second coating compositions prepared in Comparative Example 1 were mixed at a volume ratio of 3: 1 to prepare a clear coating composition. The mixture was allowed to stand at 25 캜 for 14 to 16 seconds with a Porous Cup # 4 viscometer at a relative humidity (RH) of 60% and an ambient temperature of 25 캜. The prepared clear coating composition was applied to the specimen as follows. And dried and cured at room temperature without setting the painting time and the set time.

As a specimen surface-treated with zinc phosphate, a primer-surfacer for automobile repair was painted to a thickness of 50 to 60 μm on the front fender of a car. Dried at about 70 ° C for about 20 minutes, and dry-polished with a # 400 abrasive paper. Thereafter, the base coat color paint was applied to a thickness of 15 to 20 탆, and after about 10 minutes, the transparent paint composition according to each of the above Examples and Comparative Examples was applied. Spray coating was performed twice to obtain a coating film thickness of 40 to 60 占 퐉. The coating film performance was evaluated after drying at room temperature (25 ° C) while changing the time according to the conditions.

The results of physical properties of the cured coating film specimens are shown in Table 1. The physical properties evaluation method is as follows.

Solids: 1 to 3 g of the sample was collected after mixing the base and the hardener to a viscosity capable of spraying, heated at 150 캜 for 2 hours, and then the solid content was measured.

Pot life: We measured the time required for the viscosity to reach twice as high as the spray viscosity.

Drying (pendulum hardness): measured with a Braive instrument test fixture. The measurement method was measured in terms of time (s) of the Konig according to DIN 53157. It was applied to a glass plate at 76 탆 and measured after 30, 60, and 120 minutes of natural drying at 25 캜 at room temperature. When the pendulum hardness was measured for 30 s or more, it was judged that a subsequent process was possible.

Immersion water resistance: Impregnation was carried out in a constant temperature bath at 40 캜 for 7 days to measure the surface state and adhesion of the coating film. ? Indicates excellent,? Indicates somewhat defective, and X indicates defective.

Impact resistance: The degree of damage of the film was measured by dropping a weight of 500 g at 30 ° C at 20 ° C.

Polishing time: The time taken for the polishing operation to become possible when curing at room temperature was measured.

Acid resistance: 0.1 to 1 g of a stock solution of sulfuric acid was dropped into a dropper to confirm swelling of the film in a state of being dipped in a 20% aqueous H ₂ SO ₄ solution for 24 hours and in a state of harsh conditions . ? Indicates excellent,? Indicates somewhat defective, and X indicates defective.

Scratch resistance: Measured using a lab-scale car wash apparatus. The water pressure was 3 bar, the brush speed was 110 rpm, the wash cycle was 10, and the wash mixture was 1.5 g / liter of quartz powder ). The water temperature was tested at 20 to 25 ° C, and the gloss retention was measured at an angle of 25 ° and an angle of 20 °.

<Table 1>

From the results shown in Table 1, it can be seen that the clear coating composition prepared according to the embodiment of the present invention has a hardness (dried composition) of the coating film increased by more than two times after 1 hour at room temperature. Also, it can be confirmed that the polishing operation is possible after about 30 minutes at room temperature.

By using the ultrafine clear coating composition of the present invention as described above, it is possible to form a coating film having satisfactory dryness even by natural drying for a short time. Therefore, it is an environmentally friendly composition which can reduce the amount of carbon dioxide gas while reducing the energy and time required for the operation. Especially, it can be easily applied to the product field of automobile repair.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. You will understand.

Claims (12)

A first coating composition comprising 50 to 70% by weight of a two-pack type acrylic polyol resin, 0.05 to 2% by weight of a urethane reaction catalyst, 28 to 48% by weight of an organic solvent, 0.5 to 5% by weight of a surface modifier, and 0.5 to 5% ; And
A second coating composition comprising 50 to 70% by weight of an isocyanate compound and 30 to 50% by weight of an organic solvent. The clear coating composition for ultra fast repair according to claim 1, wherein the clear coating composition has a volatile organic solvent content of 460 to 560 g / l. The acrylic resin composition according to claim 1, wherein the two-pack type acrylic polyol resin comprises 10 to 40% by weight of an aromatic vinyl-based monomer, 10 to 40% by weight of a vinyl-based monomer having a hydroxyl group, 1 to 10% And 10 to 40% by weight of a vinyl monomer having a vinyl group. The two-component acrylic polyol resin according to claim 3, wherein the two-part type acrylic polyol resin has a number average molecular weight in the range of 6,000 to 10,000, an OH content in the range of 4 to 5% by weight on a solid basis, and a glass transition temperature in the range of 70 to 90 ° C By weight based on the total weight of the transparent coating composition. The process according to claim 1, wherein the urethane reaction catalyst is selected from the group consisting of dibutyltin dilaurate, zinc octoate, stannous octate, dibutyl tin diacetate, dibutyl tin dimeride, triethyl diamine, triethylethanolamine, 1,4 - diazo cyclooctane, 2-dimethylaminoethyl, trimethylaminoethylethanolamine, pentamethyldiethylenetriamine, dimethylethanolamine, ethylmorphyrin, dimethylaminoethylmorpholine, dimethylcyclohexylamine and an alkali metal carboxylate Wherein the transparent coating composition is at least one selected from the group consisting of the following. The clear coating composition for ultra fast repair according to claim 1, wherein the isocyanate compound is hexamethylene diisocyanate trimer. The clear coating composition for ultra fast repair according to claim 1, wherein the weather resistance improver comprises an ultraviolet absorber and a UV stabilizer. The method of claim 1, wherein the first coating composition and the second coating composition are mixed such that the hydroxy equivalent weight in the first coating composition and the isocyanate equivalent in the second coating composition are in a ratio of 1: 0.9 to 1.1 A transparent coating composition for ultra-fast repair. A first coating composition comprising 50 to 70% by weight of a two-pack type acrylic polyol resin, 0.05 to 2% by weight of a urethane reaction catalyst, 28 to 48% by weight of an organic solvent, 0.5 to 5% by weight of a surface modifier, and 0.5 to 5% A second coating composition comprising 50 to 70% by weight of an isocyanate compound and 30 to 50% by weight of an organic solvent, on a substrate;
Drying the applied coating composition to form a dried coating film; And
And polishing the dried coating film. The method for forming a coating film according to claim 9, wherein the drying is carried out at a room temperature of 20 ° C or more for 0.5 to 1 hour, at 60 ° C for 10 minutes, or by irradiation of infrared rays. The method for forming a coating film according to claim 9, wherein the coating film has a thickness ranging from 40 to 60 mu m. The method for forming a coating film according to claim 9, wherein the clear coating composition is a composition for repairing an automobile, which is applied on top of a base coat color paint by spraying.