KR101131888B1 - Paint composition for plastics and method of preparing the same - Google Patents

Abstract

A coating composition for plastics and a method of manufacturing the same are disclosed. 30 to 55 wt% of polyurethane resin of polyester polycarbonate mixture, 2 to 20 wt% of curing agent, 1 to 10 wt% of matting agent, 1 to 15 wt% of antisettling agent, 0.5 to 2 wt% of light stabilizer and 20 to 20 wt% of solvent 65.5 wt%. The scratch resistance of the coating film formed by using this can be significantly improved, and sufficient elasticity to protect the coating surface can be realized to increase the designability of the coating material, provide soft touch, and increase the strength of the coating surface.

Description

Paint composition for plastics and method for manufacturing the same {PAINT COMPOSITION FOR PLASTICS AND METHOD OF PREPARING THE SAME}

The present invention relates to a coating composition for plastics and a method for manufacturing the same, and more particularly, to a coating composition for plastics and a method for producing the same which can provide excellent scratch resistance while having excellent physical properties such as wear resistance, adhesion and heat resistance. .

In recent years, the production of plastics has increased significantly. Plastics have a number of advantages, such as being light and pigmented without corrosion compared to metals, but when used in general products, paintability and other functionality need to be imparted to increase the value of the product.

In addition, plastics are vulnerable to deformation due to chemicals, erosion, ultraviolet rays, heat, and the like. In addition, plastics have surface area defects due to marks, surface defects and color limitations during injection. In order to solve these problems, conventionally, oily acrylic lacquer is coated to compensate for defects of plastic materials.

Such conventional oil-based acrylic lacquer paints have good physical properties such as heat resistance, moisture resistance, and adhesion, but have a poor scratch resistance, so that the texture is not cold and soft when in contact with the coating film and human skin. there was.

Therefore, the technical problem of the present invention is a paint composition for plastic materials that can realize high value-added plastic materials by realizing coating properties such as abrasion resistance, adhesion and heat resistance of oil paint, elasticity, excellent scratch resistance, and soft texture in oil paint. To provide.

Another object of the present invention is to provide an easy method for producing a coating composition for a plastic material.

Coating composition for plastics for realizing the above object of the present invention is 30 to 55% by weight of the polyurethane resin of the polyester polycarbonate mixture system; Curing agent 2-20 wt%; 1 to 10 wt% matting agent; Sedimentation inhibitor 1-15% by weight; Light stabilizer 0.5 to 2% by weight; And 20 to 65.5 wt% of a solvent.

In one embodiment, the polyurethane resin of the polyester polycarbonate mixed system is a polyol and diisocyanate obtained by mixing the polyester polyol and polycarbonate polyol in a weight ratio of 1: 9 to 9: 1 of 1.01 to 3: 1 It is obtained by reacting in molar ratio.

In one embodiment, the matting agent is a silica dispersion having a particle diameter of 1 ~ 30㎛ range, the anti-settling agent is a polyamide wax made from fatty acids and polyamines, the light stabilizer is a UV absorber (absorb ) And UV HALS (hindered amine light stabilizer) systems can be used.

In one embodiment, the polyurethane resin has a molecular weight ranging from 8,000 to 50,000.

As the solvent, at least one of ester, aromatic hydrocarbon, and ketone compounds may be used.

Another object of the present invention described above is 30 to 55% by weight of a polyurethane resin of the polyester polycarbonate mixture system; Curing agent 2-20 wt%; 1 to 10 wt% matting agent; Sedimentation inhibitor 1-15% by weight; Light stabilizer 0.5 to 2% by weight; And it is achieved by a method for producing a coating composition for plastics material comprising the step of mixing 20 to 65.5% by weight of the solvent.

In one embodiment, the polyester polyol has a molecular weight ranging from 500 to 3,000, a condensation reaction product of an alcohol compound containing diethylene glycol and methyl propanediol and an acid containing adipic acid and isophthalic acid is used, The polycarbonate polyol has a molecular weight in the range of 500 to 3,000, and a condensation reaction product of an alcohol compound containing hexanediol and cyclohexanedimethanol and a carbonate compound containing diethyl carbonate is used.

In one embodiment, the diisocyanate is at least one selected from the group consisting of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate having 80% by weight of 2,4-toluene diisocyanate and diphenylmethane diisocyanate Use it.

According to such a plastic composition, since the coating properties, elasticity, excellent scratch resistance, and soft texture, such as wear resistance, adhesion, and heat resistance of the conventional oil-based paint can be realized, they can be used for high value-added plastic materials. Do.

Hereinafter, the present invention will be described in more detail. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, ingredient, step, process, composition, or combination thereof described on the specification, one or more other features or ingredients, It is to be understood that it does not preclude the presence or possibility of addition of steps, processes, compositions or combinations thereof.

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 the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and, unless expressly defined in this application, are construed in ideal or overly formal meanings. It doesn't work.

In the present invention, in order to solve the problem that the plastic material is easily deformed due to chemicals, heat, surface defects due to surface defects or color limitations, etc., the coating composition is excellent in elasticity and excellent in scratch resistance.

Such a plastic coating composition is 30 to 55% by weight of polyurethane resin of polyester polycarbonate mixture, 2 to 20% by weight of curing agent, 1 to 10% by weight of matting agent, 1 to 15% by weight of antisettling agent, 0.5 to 2 light stabilizer It comprises 20% by weight and 20% to 65.5% by weight of solvent, and the type and role of each component will be described in more detail.

<Polyurethane resin of polyester polycarbonate mixture type>

The polyester polyol used to prepare the polyurethane resin as a main component can be prepared by condensation reaction of an alcohol compound and an acid. Specifically, a polyester having a molecular weight of 500 to 3,000 based on diethylene glycol and adipic acid can be preferably used, and 500 is obtained by condensation reaction of an alcohol compound such as methylpropanediol with an acid such as adipic acid or isophthalic acid. Polyester polyols having a molecular weight of ˜3,000 can be preferably used.

Polycarbonate polyol is prepared by condensation reaction of an alcohol compound and a carbonate compound. Specifically, a polyol synthesized by condensation reaction of an alcohol compound, such as hexanediol and cyclohexanedimethanol, with a carbonate containing diethyl carbonate, has a molecular weight of 500 to 3,000. It is preferably usable.

In order to prepare a mixed polyurethane resin, a polyester polyol and a polycarbonate polyol prepared according to the above-described method are mixed, wherein the mixing ratio of the two polyols is 1: 9 to 9: 1 by weight. Polyester polyol has the advantage of having a smooth texture and excellent slip resistance, but has the disadvantage of physical properties such as water resistance, chemical resistance and the like. In order to compensate for this, a polycarbonate polyol is added and used, and by this mixing, physical properties of the polyester polyol can be supplemented, and in addition, elasticity can be given.

Diisocyanates for use in preparing polyurethanes in combination with polyol compounds include non-yellowing types such as isophorone diisocyanate, hexamethylene diisocyanate, and the like, toluene diisocyanate with di 2,4-toluene diisocyanate, diisocyanate Phenylmethane diisocyanate can be used. In addition, it is preferable to use N-methylpyrrolidinone as a solvent for reaction rate and viscosity control and uniform reaction.

The molar ratio of the polyol and the diisocyanate for producing the mixed polyurethane were used so that the molar ratio of the polyol was 1.01 to 3: 1 so that the molar ratio of the polyol was slightly excessive. This is to ensure that the diisocyanate used is used in almost all reactions.

As a polyurethane resin of the polyester polycarbonate mixture system manufactured, the thing of the molecular weight 8,000-50,000 is used suitably when considering a physical property and other performance.

In preparing the coating composition, the amount of the polyurethane resin to be in the range of 30 to 55% by weight based on the total amount of the composition. If the amount thereof is less than 30% by weight, there is a problem that the physical properties of the coating film such as adhesion, scratch resistance, etc. is lowered. If the amount thereof is more than 55% by weight, storage and elasticity are deteriorated.

<Hardener>

The curing agent added for curing the coating composition is preferably a hexamethylene diisocyanate trimer system having excellent yellowing resistance and weather resistance, and preferably contained in a range of 2 to 20% by weight based on the coating composition. If the content is less than 2% by weight, there is a problem that it is difficult to secure the physical properties of the coating film because hardening of the paint does not occur, and if it exceeds 20% by weight, the amount of the hardener is too large and the pot life is shortened, resulting in operational problems. Because it can cause.

<Quenching agent>

As the matting agent that serves to reduce or eliminate the gloss of the material, silica gel, precipitated silica, titanium dioxide and the like can be used. In particular, in the present invention, it is preferable to use a micronitized silica dispersion having an average particle diameter of about 1 to 30 µm. If the average particle diameter thereof exceeds 30 μm, a problem may occur in that the surface of the coating film becomes rough and the appearance of the coating film is poor and the scratchability may be deteriorated. Therefore, it is preferable to use a dispersion having the above particle size range.

The microized silica dispersion having an average particle diameter of about 1 to 30 μm is preferably included in the coating composition in the range of 1 to 10 wt%, and when the content is in the above range, the effect of improving the photosensitive (quenching) surface texture may be obtained. There is. The amount of the quencher is in the range of 1 to 10% by weight, based on the total amount of the composition. If its content is less than 1% by weight, it is difficult to obtain a matting effect, and if it exceeds 10% by weight, there is a weak problem in scratching.

<Sedimentation inhibitor>

As the antisettling agent added to prevent sedimentation of heavy components such as white pigments in the coating composition, various kinds such as aluminum stearate, silica, organoclay, polyamide wax, and the like can be used. In the present invention, in particular, polyamide waxes prepared from fatty acids and polyamines are preferably used. It is added to the paint to form a flake structure, thereby exhibiting a sedimentation prevention effect. In addition, due to the network structure of the swelling particles, it is excellent in strong thixotropy and thermal stability. Anti-settling agents such as polyamide wax may be included in the coating composition in an amount of 1 to 15% by weight, and if it is within this range, a scratch improvement effect may be obtained. If the content thereof is less than 1% by weight, the sedimentation prevention effect is difficult to be obtained, and if it exceeds 15% by weight, there is a problem of being weak to scratches.

<Light stabilizer>

The light stabilizer is effective to prevent aging, color change, etc. of the coating film generated by exposure to light for a long time, and performs UV blocking, light energy absorption and conversion, and free radical removal. UV absorbers and UV hindered amine light stabilizers, which are organic amine compounds with steric hindrance, should be mixed and used. As the ultraviolet absorbing light stabilizer, various kinds such as benzophenone series, oxanilide series, benzotriazole series and triazine series can be used. As the organic amine light stabilizer, 4-benzoyloxy-2,2,6,6-tetramethylbiferidine, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-hydroxybenzoide Etc. can be used. Preferably, it is suitable to mix and use the ratio of an ultraviolet absorber and an ultraviolet-inhibited amine light stabilizer system in a weight ratio of 2: 1. If the content thereof is less than 0.5% by weight, there is a problem that the coating film is easily yellowed and gloss is degraded over time, and when the content is more than 2% by weight, the paint storage stability becomes unstable.

<Solvent>

Solvent is one or more selected from the group consisting of ester, aromatic hydrocarbon, and ketone, which are excellent in terms of dispersion stability, and the content of such solvent may be changed depending on the material and the required thickness of the coating film and the method of forming the coating film. 20 to 65.5% by weight is suitable.

In addition to the above components, the plastic coating composition having excellent elasticity and excellent scratch resistance may further include various additives such as a wetting agent, an antifoaming agent, and the amount of these additives may be appropriately added or subtracted according to the desired end use and various factors. Can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by these Examples.

&Lt; Example 1 >

First, the polyurethane resin of the polyester polycarbonate mixing system was prepared as follows. First, 450 g of polyester polyol having a molecular weight of 500 to 3,000 obtained by using 94 g of N-methylpyrrolidone, 78 g of diethylene glycol, and 100 g of adipic acid in a reaction vessel provided with a reflux condenser, a nitrogen gas inlet tube, a thermometer, a stirrer, 80 g of hexanediol and 100 g of diethyl carbonate were condensed to mix 300 g of a polycarbonate polyol having a molecular weight of 500 to 3,000. Polyester polyol and polycarbonate polyol were mixed at a weight ratio of about 1.5: 1 and sufficiently stirred under nitrogen stream for about 30 minutes.

48 g of hexamethylene diisocyanate was added to a polyester polycarbonate mixed polyol, and heated to about 60 to 100 ° C., followed by stirring for about 6 hours to prepare a polyurethane resin of a polyester polycarbonate mixture.

The coating composition which concerns on Example 1 was manufactured using each component with the obtained polyurethane resin of the molecular weight 8,000-50,000 polyester polycarbonate mixing system, and a composition as shown in Table 1. That is, 45% by weight of polyurethane resin of the polyester polycarbonate mixture, 6.5% by weight of hexamethylene diisocyanate, 6.5% by weight of matting agent, 1.5% by weight of light stabilizer, 6% by weight of antisettling agent, flow inhibitors, antifoaming agents, A coating composition according to the present invention was prepared by mixing and dispersing 5.9 wt% of a slip agent and 28.6 wt% of a solvent.

The coating composition according to Comparative Examples 1 and 2 was prepared by changing the amount of polyurethane resin used in the polyester polycarbonate mixed system and changing the amount used for other components as shown in Table 1, respectively.

The light stabilizer was used by mixing the UV absorber and the UV HALS system in a weight ratio of 2: 1, and the solvent contained xylene, MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), and butyl acetate at 1: 2: 8: 10. The mixture was used by weight ratio.

TABLE 1

The following tests were carried out using samples of the coating composition for plastics prepared according to the above Examples and Comparative Examples.

<Test Example: Evaluation of Coating Film Properties>

In order to improve the adhesion to the raw materials of the paints prepared according to Example 1 and Comparative Examples 1 and 2, the oily primer was coated to a thickness of 12 to 25 μm on a polypropylene test piece and dried at room temperature for about 10 minutes. Then, each coating composition prepared in the composition shown in Table 1 was coated with a thickness of 20 ~ 80㎛, left for 5 minutes at room temperature and dried for 30 minutes at 80 ℃ to complete the sample. Using the completed sample, various evaluation tests were performed for each of the following items.

Adhesion test at room temperature: After 11-cut cross-cuts at 2mm intervals in the horizontal and vertical directions on the specimen, the surface is cleaned with a soft brush and firmly attached with a prescribed tape of the appropriate width and length. The number of peeled coating scales was counted by pulling strongly at an angle of 90 degrees. Also referred to as a checker board adhesion test, the greater the number of peeling on a total of 100 checkerboard scale was evaluated as poor adhesion.

Heat test: After leaving for 300 hours at 110 ° C, taken out, and left for 1 hour at room temperature, the adhesion test was performed immediately.

Light test: Under XENON ARC, irradiate until the total cumulative light amount is 1050KJ / m ² under the condition of black panel temperature 89 ± 3 ℃, in-house humidity 50 ± 5%, RH illuminance 340 nm The adhesive test was carried out after washing with water, dried with air, and left at room temperature for 1 hour.

Scratch test: When the coated specimens according to Example 1 and Comparative Example 1-2 were moved perpendicular to the coating surface by using a sapphire scratcher under a load of 100 mm and 0.5 kgf in stroke according to JIS K 6718, the coating film was evaluated for damage. The result was confirmed. At this time, evaluation of the scratch property was shown to be excellent (5)-poor (1) according to the grade.

Coating properties were taken after the evaluation of the five specimens for each composition and the results are shown in Table 2.

Table 2

As shown in Table 2, when the content of the polyester polycarbonate mixed polyurethane resin is about 45% by weight, as in Example 1, excellent elasticity and scratchability can be realized. In Comparative Examples 1 and 2, it can be confirmed that the adhesion at room temperature, the heat resistance, and the light resistance are excellent, but the elasticity and the scratch resistance are not satisfactory.

As described above, the plastic coating composition of the present invention can significantly improve the scratch resistance of the conventional oil paint, and in addition, to realize a sufficient elasticity in the oil paint to protect the paint surface, The high added value of plastic materials can be realized by improving the properties, providing soft touch and increasing the strength of the painted surface.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (11)

30 to 55% by weight of polyurethane resin in the polyester polycarbonate mixed system; Curing agent 2-20 wt%; 1 to 10 wt% matting agent; 1-15 wt% of at least one antisettling agent selected from the group consisting of aluminum stearate, organoclays and polyamide waxes prepared from fatty acids and polyamines; Light stabilizer 0.5 to 2% by weight; And Coating composition for plastic materials containing 20-65.5 weight% of solvents. The method according to claim 1, wherein the polyurethane resin of the polyester polycarbonate mixed system is a polyol and diisocyanate obtained by mixing a polyester polyol and a polycarbonate polyol in a weight ratio of 1: 9 to 9: 1 of 1.01 to 3: 1 A coating composition for plastic materials, characterized by being obtained by reacting at a molar ratio. The plastic material as claimed in claim 1, wherein the matting agent is a silica dispersion having a particle size in the range of 1 to 30 µm, and the light stabilizer is a mixture of a UV absorber and a UV hindered amine light stabilizer system. Paint composition for use. The coating composition for a plastic material according to claim 1, wherein the polyurethane resin has a molecular weight in the range of 8,000 to 50,000. The coating composition for a plastic material according to claim 1, wherein the solvent is at least one of an ester-based, aromatic hydrocarbon-based, and ketone-based compound. 30 to 55% by weight of polyurethane resin in the polyester polycarbonate mixed system; Curing agent 2-20 wt%; 1 to 10 wt% matting agent; 1-15 wt% of at least one antisettling agent selected from the group consisting of aluminum stearate, organoclays and polyamide waxes prepared from fatty acids and polyamines; Light stabilizer 0.5 to 2% by weight; And 20 to 65.5% by weight of a solvent. The method according to claim 6, wherein the polyurethane resin has a molecular weight in the range of 8,000 to 50,000. The method of claim 6, wherein the polyurethane resin of the polyester polycarbonate mixed system is a polyol and diisocyanate obtained by mixing a polyester polyol and a polycarbonate polyol in a weight ratio of 1: 9 to 9: 1 of 1.01 to 3: 1 It is obtained by making it react by molar ratio. The method of claim 8, wherein the polyester polyol has a molecular weight in the range of 500 ~ 3,000, characterized in that the condensation reaction product of an alcohol compound containing diethylene glycol and methyl propanediol and an acid containing adipic acid and isophthalic acid Manufacturing method. The method of claim 8, wherein the polycarbonate polyol has a molecular weight in the range of 500 ~ 3,000, characterized in that the condensation reaction product of an alcohol compound comprising hexanediol and cyclohexane dimethanol and a carbonate compound comprising diethyl carbonate Way. The diisocyanate of claim 8, wherein the diisocyanate comprises at least one selected from the group consisting of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate having 80% by weight of 2,4-toluene diisocyanate. Manufacturing method characterized in that.