KR20070053498A - Metallizing of automotive plastic parts - Google Patents

Abstract

The present invention relates to a metallizing method of a plastic part for an automobile, and more particularly, an eco-friendly new process that is used to implement a metal color of a plastic part for an automobile to replace a wet surface treatment technology such as chromium plating, which is an environmental problem. By using a plasma formed of a target metal such as aluminum (Al), titanium (Ti), stainless steel (SUS) and an inert gas such as argon (Ar), the metal effect can be maximized compared to general paint and plating specifications. The present invention relates to a metal thin film manufacturing technology capable of realizing various metal colors in accordance with the development trend of automobiles, and to a metallizing method of plastic parts for automobiles, which has improved adhesion and wear resistance by using a coating material having excellent adhesion and wear resistance together with the metal thin film. It is about.

Plastic, Metallizing, Plasma, Abrasion Resistant, Adhesive

Description

Metallizing method for plastic parts for automobiles {METALLIZING OF AUTOMOTIVE PLASTIC PARTS}

The present invention relates to a flame retardant polypropylene nanocomposite having excellent long-term heat resistance, and more particularly, to a polypropylene resin as a main component, and to a specific amount of a flame retardant, an organic layered silicate, a compatibilizer, an antioxidant, and other additives. The present invention relates to a flame-retardant polypropylene nanocomposite suitable for use in electric and automotive parts due to its excellent long-term heat resistance, excellent workability and impact resistance, low specific gravity, and low price, compared to flame retardant polypropylene resin.

First, the metallizing manufacturing method of the plastic parts for automobiles is as follows.

1) injection molding a plastic part into a shape and shape designed using a resin;

2) performing pretreatment as a cleaning process for cleaning to improve adhesion between the surface of the plastic part produced by the injection molding and the metal thin film;

3) applying a primer over the entire surface of the plastic embedded parts to increase the adhesion after the pretreatment process;

4) coating the metal thin film on the plastic part using plasma after the primer coating is completed;

5) applying a clear coat mixed with a transparent or a photosensitizer (quencher) to improve wear resistance on the metal thin film, thereby completing manufacturing of a plastic part for an automobile;

In other words, a primer is applied over the entire surface of the plastic embedded part, a metal thin film is laminated on it, and a three-layer structure is formed on which the clear coat is applied to the outermost part.

The application of primers during the manufacturing process of plastic parts for metal parts such as automobiles is flexible depending on the plastic resin applied to the parts, but the clear coat applied after laminating metal thin films has abrasion resistance due to frequent contact. It is a process that must be carried out using paints in consideration of.

The present invention is applied to the plastic parts for automobiles, can maximize the metal effect than the general paint and plating specifications, it is possible to implement a variety of colors, the process of manufacturing metal thin film is more environmentally friendly than the conventional wet chrome plating method, and In order to prevent abrasion caused by external contact, the wear-resistant clear coat is used to maintain the high quality of the metal for a long time without damaging the range. Corresponds to

There are many plastic materials used in automotive parts, but polypropylene (PP), polycarbonate + acrylonitrile butadiene styrene (PC + ABS), acrylonitrile butadiene styrene (ABS), polycarbonate + polybutyl Lenterephthalate (PC + PBT), polyamide (PA), thermoplastic polyolefin (TPO) and the like are used, and polypropylene (PP) -based resins are generally used the most. Among the above-mentioned resins, resins such as polycarbonate + acrylonitrile butadiene styrene (PC + ABS) and acrylonitrile butadiene styrene (ABS) have polarity and have high surface tension, so that the top coat can be directly coated without primer in the coating process. Since it is known as a material that is excellent enough adhesion to paint, when implementing the metallizing effect, such a resin can be directly coated with a metal thin film without a primer.

Wet plating methods for obtaining a metal thin film include electroplating, electroless plating, and chemical conversion. Electroplating is a method of reducing and depositing a target metal in the form of ions on the surface of an article by using electrical energy to obtain a coating layer. Electroless plating is a method of chemically reducing metal ions in the plating bath without sending an electric current. It is a method of reducing and plating, and the chemical conversion method is a method of coating zinc phosphate. The three methods mentioned above are situations where the use of the pre-plating process is restricted by the release of legal regulations such as alkali, heavy metals, chromic acid and cyanide, which have a fatal effect on air and water pollution.

Plasma is applied to the automotive industry, such as Germany, and is mostly limited to machinery parts, focusing on providing characteristics such as life improvement. Raw materials suppliers such as GE Plastics are conducting research and development in order to expand their applicability. Plastic suppliers and coating companies are focusing on securing new markets using new technologies in accordance with regulations on the use of hazardous substances. Currently, most of the plastic parts for automobile decoration have been subjected to wet chrome plating, and efforts to replace them with environmentally friendly processes and raw materials are being researched and developed by companies such as GE Plastics, a raw material supplier. Focusing on developing surface treatment technology using plasma. In addition, in Germany and other countries, R & D is undertaken to apply coating technology by applying vacuum plasma technology. Raw material suppliers are investing in raw material development to concentrate on developing technology to improve color and mechanical properties. Many efforts are being made to study wear resistance and decorative properties.

In Korea, plastic raw material suppliers such as Hyosung and SKC are trying to expand their market share by introducing new technologies.In the automotive industry, they are focusing on securing competitiveness in the automotive sector by pursuing high-end cars and high-end interior decoration parts. have. At present, the trend of finding new parts and designing automobiles is changing due to the tendency to pursue environmental friendliness and comfort rather than convenience. Accordingly, the use of harmless products in the interior parts is expanding. There are companies that produce automobile interior parts in Korea such as Seungwon, Woojin Alpha, Daedong, etc., but the technology for surface treatment of plastics using plasma has not been introduced. Most of the applied parts are plated using hexavalent chromium, and there is little effort to improve them technically. Due to the low quality of chromium plated products, the coating film is peeled off. It is one of the factors that lowers the quality. The color of interior materials is currently being made in the form of supplying desired characteristics from plastic raw material suppliers and injection molding companies. Plastic parts for automobile decoration have a tendency to increase with the increase in the production of automobiles, and when applied to high-end models and new models based on new technology, it can be expanded to all models produced in the future.

Metallic material implementation method used in the conventional plastic parts for automobiles is largely the wet chromium coating method and the method of using metallic paint, both of which were almost the most. As mentioned above, the wet chromium plating method is regulated due to the rise of environmental problems, and in the case of metallic paints, the metallization effect is reduced because the grain size is larger than that of the actual metal thin film coating. In addition, the present invention can additionally implement a metal feeling excellent in wear resistance than chromium plating by coating a clear coat on the metal thin film.

In addition to the wet chromium coating method, a method of coating a metal thin film can be roughly classified into a vacuum deposition method and a sputtering method according to the principle thereof. The vacuum deposition method was first performed by FARADAY in 1857, and is a method widely used in the metal thin film manufacturing method by depositing evaporated particles on the surface of a substrate by heating a metal or alloy in a vacuum and evaporating it from a molten state. Sputtering is a method of vaporizing a plating material using kinetic energy of gas. Both methods differ from wet plating in that the deposited material is not solidified in the liquid phase but solidified in the gas phase.

The wear resistance problem is a phenomenon in which the driver or passengers lose the original color or texture when contacting the interior parts more than tens of thousands of times inside the vehicle, and inside door handles, various switches, gear knobs, and other ornaments have a particularly high frequency of contact. If the metal parts are used for the high quality of the automobile as interior parts, a clear coat with excellent wear resistance must be used. In addition, in the case of exterior parts for automobiles as well, a lot of external contact occurs in the radiator grille, various logos, etc., so a clear coat having improved wear resistance should be used. Conventional wet plating does not use a clear coat and thus has a limit on abrasion resistance, and in order to improve this, it is essential to use a clear coat having excellent abrasion resistance.

The present invention is an environmentally friendly method compared to the conventional wet chromium plating method as described above, and can realize a sense close to the metal compared to the metallic paint, as a result of research efforts to express a variety of metallic colors to implement, By introducing primer and clear coat composition to improve metalizing effect, adhesion and abrasion resistance, and using plasma formed of inert gas such as metal and argon (Ar) In particular, the present invention was completed by confirming that abrasion resistance) can be improved.

Accordingly, the present invention provides a metallizing method of plastic parts for automobiles by applying a primer to increase adhesion and by using plasma to realize environmentally friendly metals of various colors, raising the clear coat to maximize wear resistance. There is a purpose.

The present invention relates to a metallizing method of a plastic part for an automobile, and more particularly, an eco-friendly new process that is used to implement a metal color of a plastic part for an automobile to replace a wet surface treatment technology such as chromium plating, which is an environmental problem. By using a plasma formed of a target metal such as aluminum (Al), titanium (Ti), stainless steel (SUS) and an inert gas such as argon (Ar), the metal effect can be maximized compared to general paint and plating specifications. The present invention relates to a metal thin film manufacturing technology capable of realizing a variety of metal colors in accordance with the development trend of automobiles, and is characterized by improved adhesion and wear resistance by using a coating material having excellent adhesion and wear resistance together with the metal thin film.

The present invention will be described in more detail as follows.

The paint and metal thin film structure of the present invention is a three-layer structure in which a primer is applied over the entire surface of a plastic part, a metal thin film is laminated thereon, and a clear coat is applied to the outermost part. The coating film thickness of each layer is about 20-25 micrometers of a primer layer, about 150-400 micrometers of metal thin film layers, and about 25-60 micrometers of a clear coat layer, and a coating film thickness is fluctuate | varied according to the plastics kind of automotive parts, and the required wear resistance. However, the metal thin film layer is preferably about 150 to 400 ° C. in view of appearance, adhesion performance and productivity.

Primers used to improve adhesion in the present invention is 30 to 40% by weight of acrylic polyol, 5 to 10% by weight of melamine resin, 0.5 to 1.5% by weight surface modifier as additives, 1 to 2% by weight curing accelerator, aromatic hydrocarbon-based organic 20 to 25 wt% solvent, 3 to 7 wt% ester organic solvent, 15 to 20 wt% alcohol organic solvent and 5 to 10 wt% ketone organic solvent, solid content of 40 to 45 wt% to be. At this time, the acrylic polyol is selected from the ester type, ether type and polycarbonate polyol, when the content thereof is less than 30% by weight, the degree of curing is poor, if it exceeds 40% by weight the problem of poor storage and adhesion have. In addition, the melamine resin is selected from butyrate, trimethyl and hexamethylol, and when the content thereof is less than 5% by weight, there is a problem that the degree of curing is lowered, and when it exceeds 10% by weight, yellowing occurs when curing. In addition, the surface modifier may be selected from polyester-based, silicone-based, and modified silicone-based, when the content thereof is less than 0.5% by weight, there is a problem that the surface leveling is falling, if the content exceeds 1.5% by weight there is a problem that the adhesion is lowered. The curing accelerator is selected from an isocyanate-based, modified polyimide-based, and peroxide-based, and if the content thereof is less than 0.5% by weight, there is a problem of uncured occurrence, and if it exceeds 2% by weight, there is a problem of poor storage. Aromatic hydrocarbon organic solvent is selected from toluene, xylene, and xylene, when the content is less than 20% by weight of the coating agent has a problem of high workability due to the high viscosity of the coating, if exceeding 25% by weight of the material There is a problem of eroding the surface. The ester organic solvent is selected from ethyl acetate, butyl acetate and propyl acetate, and when the content thereof is less than 3% by weight, there is a problem of poor solvent compatibility, and when the content exceeds 7% by weight, whitening occurs during curing. There is. Alcohol-based organic solvents are selected from isobutyl alcohol, propyl alcohol and butyl alcohol, when the content thereof is less than 15% by weight, there is a problem that the surface leveling is lowered, if the content exceeds 20% by weight whitening occurs during coating there is a problem. Ketone-based organic solvents are selected from methyl ethyl ketone, methyl propyl ketone and methyl isobutyl ketone, if the content is less than 5% by weight, there is a problem that the adhesion is lowered, if the content exceeds 10% by weight to corrode the material there is a problem.

There are many plastic materials used in automotive parts, but polypropylene (PP), polycarbonate + acrylonitrile butadiene styrene (PC + ABS), acrylonitrile butadiene styrene (ABS), polycarbonate + polybutylene Terephthalate (PC + PBT), polyamide (PA), thermoplastic polyolefin (TPO) and the like are used, and polypropylene (PP) -based resins are generally used the most. Among the above-mentioned resins, resins such as polycarbonate + acrylonitrile butadiene styrene (PC + ABS) and acrylonitrile butadiene styrene (ABS) have polarity and have high surface tension, so that the top coat can be directly coated without primer in the coating process. Since it is known as a material that is excellent enough adhesion to paint, when implementing the metallizing effect, such a resin can be directly coated with a metal thin film without a primer.

The role of the primer not only enhances the adhesion between the plastic molded part and the metal thin film, but also serves as an aid to conceal the appearance defects inevitably caused by the molding conditions.

Metallizing is a hybrid technology that combines the fast deposition rate obtained by evaporation and the dense thin film microstructure obtained by sputtering and the compound forming ability. In other words, it is a method of using an evaporation source used in evaporation as it is, but partially ionizing evaporation atoms (with reaction gas, if necessary) by introducing plasma to increase kinetic energy and reactivity.

Metallizing is performed by inert gas (mainly Ar, Kr, Xe, etc.) in a vacuum to form a plasma, and then hit the target metal (Al, Ti, SUS, Cr, etc.) negatively biased by the momentum transfer by the momentum transfer The DC bias is used when the target metal is a conductor to release atoms of. The released atoms move freely in the vacuum chamber and the atoms incident on the plastic molded part form a deposition layer. Since metallized atoms have relatively high kinetic energy by momentum transfer, surface diffusion occurs to a thermodynamically stable position when forming deposition on the surface of the plastic molded part, thus forming a film having a dense structure.

Metallizing is also used to plate single metals, but more important is the synthesis and plating of compounds. In particular, the production of metal thin films centered on nitrides of transition metals cannot be produced by other methods. When a reactive gas (O ₂ , N ₂ , NH ₃ , CH ₄ , C ₂ H _4, LPG, etc.) is mixed with an inert gas, the reactive gas molecules are also ionized and activated together and released from the target metal. And react to form a compound film of nitride, carbide or the like.

Conventionally, sufficient energy is required to manufacture compound films such as nitrides and carbides other than oxides. Therefore, a high temperature of 800 ° C. or higher is required to supply only the energy required for compound synthesis with heat energy. It was difficult to apply because it involves a change in mechanical properties, and of course, plastic moldings were impossible because they could not be melted and maintained in high temperature conditions.

When plasma is introduced, a portion of the gas is ionized and neutral atoms (or molecules) that are not ionized also have high kinetic energy due to the collision by electrons. In particular, when the cathode bias is applied to the target metal, the ions accelerate and enter the target metal, thereby adding more kinetic energy to compensate for the insufficient thermal energy. Can be.

Clear coat applied after laminating the metal thin film is a process that must be carried out by using a paint considering the wear resistance due to frequent contact due to the characteristics of the automotive parts.

The wear resistance problem is a phenomenon in which a driver or a passenger loses original color or texture when contacting an interior part more than tens of thousands of times in an interior of a vehicle, and inside door handles, various switches, gear knobs, and other ornaments have a particularly high contact frequency. If the metal parts are used for the high quality of the automobile as interior parts, a clear coat with excellent wear resistance must be used. In addition, in the case of exterior parts for automobiles as well, a lot of external contact occurs in the radiator grille, various logos, etc., so a clear coat having improved wear resistance should be used. Conventional wet plating does not use a clear coat and thus has a limit on abrasion resistance, and in order to improve this, it is essential to use a clear coat having excellent abrasion resistance.

Preferred clear coats for the present invention are 35 to 40% by weight of acrylic polyol, 5 to 10% by weight of a non-yellowing isocyanate resin, which is a curing agent, 1 to 2% by weight of a surface regulator as an additive, 2 to 5% by weight of a light stabilizer, and 1 to 2 curing accelerators. Solid content, consisting of weight%, photosensitizer (quenching agent) 0 to 3% by weight, aromatic hydrocarbon-based organic solvent 15 to 20% by weight, ester organic solvent 10 to 15% by weight and ketone organic solvent 15 to 20% by weight The content is about 45% by weight. At this time, the acrylic polyol is selected from the ester type, ether type and polycarbonate polyol, when the content thereof is less than 35% by weight, there is a problem that the degree of curing is lowered, if the content exceeds 40% by weight the problem of storage and adhesion have. In addition, the non-yellowing isocyanate resin is selected from isoprone diisocyanate and hydronized methylene diisocyanate, and if the content thereof is less than 5% by weight, there is a problem of yellowing upon curing, and when it exceeds 10% by weight, whitening and There exists a problem that water resistance falls. In addition, the surface modifier may be selected from polyester, silicone and modified silicone, and if the content thereof is less than 0.5% by weight, there is a problem that the surface leveling falls, and if it exceeds 2% by weight, the adhesion is reduced (when repainting). ) there is a problem. The light stabilizer is a mixture of UV up-based and UV Hals-based, when the content is less than 1% by weight of the yellowing and the problem of deterioration of gloss, if the content exceeds 5% by weight there is a problem of unstable coating surface . The curing accelerator is selected from isocyanate crab, modified polyimide and peroxide, and if its content is less than 0.5% by weight, there is a problem of uncuring. If the content exceeds 2% by weight, storage stability is reduced and the pot life is shortened. there is a problem. As a photosensitizer (quenching agent), one selected from silica-based, aliphatic hydrocarbon-based waxes and silica-based waxes is used. If the content thereof exceeds 3% by weight, there is a weak problem in scratching. Aromatic hydrocarbon organic solvent is selected from toluene, xylene, and xylene, when the content is less than 15% by weight of the coating agent is high viscosity problem, the workability is worsened, if it exceeds 20% by weight of the material There is a problem of eroding the surface. The ester organic solvent is selected from ethyl acetate, butyl acetate and propyl acetate, and when the content thereof is less than 10% by weight, solvent compatibility is inferior, and when it exceeds 15% by weight, the problem of whitening occurs during curing. There is. Ketone-based organic solvents are selected from methyl ethyl ketone, methyl propyl ketone and methyl isobutyl ketone, and if the content thereof is less than 15% by weight, there is a problem that the adhesion is lowered, if the content exceeds 20% by weight to corrode the material there is a problem.

In this way, the metalizing method can maximize the metal effect than general paint and plating specifications, realize various metal colors, and the process of manufacturing metal thin film is more environmentally friendly than the conventional wet chrome plating method, and is frequently used in automobiles. In order to prevent wear due to contact, the wear-resistant clear coat can be used to maintain the high quality of the metal for a long time without losing the quality of the product.

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

Example 1 and Comparative Examples 1 to 3: primer preparation

Next, the raw materials shown in Table 1 were sequentially added to TANK, stirred for about 30 minutes, and dispersed in a SAND MILL to have a particle size of 5 μm or less. Dispersion was made by dispensing about 30% of the total paint in MILL BASE and putting the rest into finishing process.

Test Example 1 Evaluation of Physical Properties of Primer Composition

The primer composition prepared according to Example 1 and Comparative Examples 1 to 3 was coated on a test piece [HT240, Hyundai EP (Engineering Plastic)] made of polypropylene material, dried at 80 ° C. for 60 minutes, and then vacuumed as in Example 5 below. After laminating an aluminum (Al) metal thin film using plasma in the state, re-coated a clear coat (Example 11) thereon, dried at 80 ° C. for 60 minutes, and allowed to stand at room temperature for 48 hours and then adhered to the following conditions. Sex test was conducted

* Room temperature adhesion test, one end of the tape was in the horizontal and vertical directions to the specimen was subjected to Cross-cut by 11 cut in 2 mm interval clean with a soft brush the surface and securely attached to the tape rule of a suitable width and length 90 ^o By pulling strongly at an angle, the number of peeled coating scales was leaked. Also called the checkerboard adhesion test, the greater the number of peelings on a total of 100 checkerboard scales, the poorer the adhesion.

* Heat resistance test: In the case of automotive interior parts, after leaving for 300 hours at 110 ℃, taken out and left for 1 hour at room temperature, the adhesion test was carried out immediately.

* Light resistance test: For automotive interior parts, the total temperature under XENON ARC is 89 ± 3 ℃, ambient humidity 50 ㅁ 5% RH, irradiation illuminance 0.55 ± 0.02 W / m ² nm (at 340 nm). After the cumulative light amount was irradiated until it became 1050 KJ / m ² , the test piece was washed with a neutral detergent aqueous solution, dried with Air, and left at room temperature for 1 hour, and then the adhesion test was carried out.

ingredient Comparative Example 1 Comparative Example 2 Example 1 Comparative Example 3 Suzy Acrylic polyol ¹⁾ - 35 35 35 Melamine ²⁾ - 8 8 8 additive Surface conditioner ³⁾ - One One One Curing accelerator ⁴⁾ - 0.5 1.5 3 solvent Aromatic Hydrocarbon ⁵⁾ - 24.5 23.5 22 Ester system ⁶⁾ - 5 5 5 Alcohol system ⁷⁾ - 19 19 19 Ketone system ⁸⁾ - 7 7 7 Sum 0 100 100 100 Result of adhesion evaluation (number of peeled scales) Room temperature 100 2 0 0 Heat resistant adhesion 100 0 0 0 Light resistance 100 5 0 2

Note) 1: Nippollan, Japan Polyurethane Industry

    2: UVAN-21R, MITSUL (Japan)

    3: BYK-303, BYK (Germany)

    4: Sunmide, Sanwa Chemical (Japan)

    5: Toluene, Samjeon Chemistry

    6: EAc, trielectric chemistry

    7: I-PrOH, Samjeon Chemistry

    8: MPK, Samjeon Chemical

As shown in Table 1, if the primer is not used as in the case of Comparative Example 1, peeling of the entire coating film occurs in the adhesion evaluation, so the use of the primer is essential in the polypropylene material. In addition, it can be seen that the adhesion improves when the curing accelerator is contained. However, when 3% by weight or more of the curing accelerator is contained (Comparative Example 3), a problem occurs in that peeling occurs in the evaluation of light resistance.

Examples 2-7: Preparation of Metal Thin Film

Inert gas (mainly Ar, Kr, Xe, etc.) was injected to obtain the partial pressure required for the plasma, a voltage of DC -500 V was applied, and a vacuum was introduced at a level of 10 ^-6 Torr, thereby inert gas was ionized to form a plasma. . As the cations of the plasma enter the target metal to which the cathode bias is applied, the metal particles collide with the surface of the plastic molded article by the momentum transfer to form the deposition layer, and the deposition layer is continuously and repeatedly generated to improve the adhesion of the deposition layer and to close the microstructure. Can get the effect.

When a reactive gas (O ₂ , N ₂ , NH ₃ , CH ₄ , C ₂ H _4, LPG, etc.) is mixed with an inert gas, the reactive gas molecules are also ionized and activated together and released from the target metal. And reacted to form a compound film such as nitride or carbide.

division Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Vacuum degree 10 ^-6 Torr Inflow POWER DC -500V Metal type Al SUS Ti Ti Ti Cr Gas type Ar Ar Ar N ₂ + Ar O ₂ + Ar N ₂ + Ar Gas mixing ratio - - - 25: 1 25: 1 25: 1 Color implementation silver Turquoise Cobalt gold chameleon silver Deposited thin film Al SUS Ti TiN TiO ₂ CrN

It is possible to realize chameleon color by synthesizing TiO ₂ thin film having optical characteristics and catalytic effect by securing color diversity by light refractive index and interference effect by light path difference.

Examples 8-18: Preparation of Clear Coat Compositions

Next, the resin was added to TANK with the composition shown in Table 3, and then the solvent was slowly added to form a uniform composition, and then dispersed in a particle size of 5 μm or less by adding to a disperser.

Test Example 2: Evaluation of Physical Properties of Clear Coat (1)

The primer composition of Example 1 was coated on a test piece made of polypropylene [HT240, Hyundai EP (Engineering Plastic)] and dried at 80 ° C. for 60 minutes, and then aluminum (Al) was used in a vacuum state as in Example 2. ) After laminating the metal thin film, the clear coat compositions of Examples 8 to 10 and Comparative Example 4 were again coated thereon, dried at 80 ° C. for 60 minutes, and allowed to stand at room temperature for 48 hours, and then subjected to abrasion resistance test according to the following conditions. Was

* Dry wear test using double-sided canvas friction material under the condition of test load 1kgf, test speed 60 reciprocation / minute and friction stroke 100mm using reciprocating abrasion tester and checking the number of times ..

* Wet abrasion test: The test method is the same as the dry abrasion test, and the test was conducted every 500 times by applying artificial sweat solution.

ingredient Example 8 Example 9 Example 10 Comparative Example 4 Suzy Acrylic polyol ¹⁾ 38 38 38 38 Hardener Non-yellowing isocyanates ²⁾ 7.6 7.6 7.6 7.6 additive Light stabilizer ³⁾ 3 3 3 3 Surface modifier ⁴⁾ 1.5 1.5 1.5 1.5 Curing accelerator ⁵⁾ One One One One Photosensitizers ⁶⁾ 0 One 3 5 solvent Aromatic Hydrocarbon ⁷⁾ 18.9 17.9 15.9 13.9 Ester series ⁸⁾ 12 12 12 12 Ketone system ⁹⁾ 18 18 18 18 Sum 100 100 100 100 Glossiness measurement result (60 ^o method) Not measurable 125 77 21 Wear resistance evaluation result Dry wear 24,000 times 19,000 times 13,000 times 8,000 times Wet wear 8,500 times 6,500 times 4,000 times 2,500 times

Note) 1: Nippollan, Japan Polyurethane Industry

    2: IPDI, Bayer (Germany)

    3: tinuvin, shivagaigi (japan)

    4: BYK-303, BYK

    5: Sunmide, Sanwa Chemical (Japan)

    6: Aerosil200, Degussa (Germany)

    7: EAc, Samjeon Chemistry

    8: I-PrOH, Samjeon Chemistry

9: MPK, Samjeon Chemical

As shown in Table 3, after laminating a metal thin film on the primer, after applying a clear coat prepared by varying the content of the photosensitizer (quencher), the gloss and wear resistance of the coating film formed was evaluated. At this time, only a small amount of aromatic hydrocarbon solvent was changed and the remaining items were fixed to compare the degree of glossiness and abrasion resistance according to the photosensitive agent (quencher) content ratio. As a result, as the content ratio of the photosensitizer (quenching agent) was confirmed that the gloss was lowered, excellent wear resistance results were obtained under the conditions of Example 8. Abrasion resistance was the weakest in Comparative Example 4 having a photosensitive agent (quenching agent) content of 5% by weight, which shows that the photosensitive agent (quenching agent) that reduces light plays an adverse role in wear resistance as its content is increased. . This demonstrates that the glossy form in which light is alive in the same color using the same target metal is more advantageous in wear resistance than the semi-glossy or matte form with reduced light.

Test Example 3 Evaluation of Physical Properties of Clear Coat (2)

The primer composition of Example 1 was coated on a test piece made of a polypropylene material, dried at 80 ° C. for 60 minutes, and laminated with an aluminum (Al) metal thin film using plasma in a vacuum state as in Example 2, followed by The clear coat composition of Example 8 was again coated, dried at 80 ° C. for 30 minutes, and left at room temperature for 48 hours, and then subjected to the above abrasion resistance test. In Examples 11 to 14, the clear coat composition was the same, and the wear resistance test was conducted with only the coating thickness being changed to 30 to 60 µm.

ingredient Example 11 Example 12 Example 13 Example 14 Suzy Acrylic polyol ¹⁾ 38 38 38 38 Hardener Non-yellowing isocyanates ²⁾ 7.6 7.6 7.6 7.6 additive Light stabilizer ³⁾ 3 3 3 3 Surface modifier ⁴⁾ 1.5 1.5 1.5 1.5 Curing accelerator ⁵⁾ One One One One Photosensitizers ⁶⁾ - - - - solvent Aromatic Hydrocarbon ⁷⁾ 18.9 18.9 18.9 18.9 Ester series ⁸⁾ 12 12 12 12 Ketone system ⁹⁾ 18 18 18 18 Sum 100 100 100 100 Coating thickness (μm) 30 40 50 60 Wear resistance evaluation result Dry wear 24,000 times 31,500 times 41,000 times 45,000 times Wet wear 8,500 times 10,500 times 12,000 times 15,000 times Result of adhesion evaluation (number of peeled scales) Room temperature 0 0 0 One Heat resistant adhesion 0 0 0 3 Light resistance 0 0 0 3

Note) 1: Nippollan, Japan Polyurethane Industry

    2: IPDI, Bayer (Germany)

    3: tinuvin, shivagaigi (japan)

    4: BYK-303, BYK

    5: Sunmide, Sanwa Chemical (Japan)

    6: Aerosil200, Degussa (Germany)

    7: EAc, Samjeon Chemistry

    8: I-PrOH, Samjeon Chemistry

9: MPK, Samjeon Chemical

As shown in Table 4, the content of the clear coat composition was fixed and the coating resistance was increased while increasing the coating thickness. It can be seen that the wear resistance is gradually improved as the thickness of the coating film is increased, and the difference in the number of holding exposures between 30 and 60 μm, which doubles the thickness of the coating film, is also approximately doubled. However, in Example 14 having a coating thickness of 60 μm, the wear resistance was the best, but a problem occurred in that the checkerboard scale was peeled off when the adhesiveness was evaluated. This is a phenomenon due to the lack of denseness due to excessive increase in the thickness of the coating film.

As described above, according to the present invention is applied to the plastic parts for automobiles, it is possible to maximize the metal effect than the general paint and plating specifications, it is possible to implement a variety of metal colors, the process of manufacturing metal thin film is conventional wet chrome It is more environmentally friendly than the plating method, and the wear-resistant clear coat is used to prevent wear due to frequent contact of the car, so that the quality of the metal can be maintained for a long time without being damaged, thereby improving the quality and quality of the product.

Claims (5)

In the metallizing method of forming a three-layer structure in which a primer is applied over the entire surface of a plastic part, a metal thin film is laminated on it, and a clear coat is applied to the outermost part. 1) The primer is 30 to 40% by weight of acrylic polyol, 5 to 10% by weight of melamine resin, 0.5 to 1.5% by weight of surface modifier as an additive, 1 to 2% by weight of curing accelerator, 20 to 25% by weight of aromatic hydrocarbon-based organic solvent , 3-7 wt% ester organic solvent, 15-20 wt% alcohol organic solvent and 5-10 wt% ketone organic solvent, having a layer thickness of 20-25 μm, 2) The metal thin film is made of a plasma formed of an inert gas, the layer is 150 ~ 400 ,, 3) The clear coat is 35 to 40% by weight of acrylic polyol, 5 to 10% by weight of a non-yellowing isocyanate resin as a curing agent, 1 to 2% by weight of a surface regulator as an additive, 2 to 5% by weight of a light stabilizer, and 1 to 2% by weight of a curing accelerator. %, Photosensitive agent (quenching agent) 0 to 3% by weight, aromatic hydrocarbon organic solvent 15 to 20% by weight, ester organic solvent 10 to 15% by weight and ketone organic solvent 15 to 20% by weight of the layer 25 ~ A metallizing method for plastic parts for automobiles, characterized in that 60㎛. According to claim 1, wherein the acrylic polyol of 1) is selected from ester type, ether type and polycarbonate type, melamine resin is selected from butyrate, trimethyl and hexamethylol, surface modifiers polyester, silicone and modified Selected from silicone, the curing accelerator is selected from isocyanate, modified polyimide and peroxide, aromatic hydrocarbon-based organic solvent is selected from toluene, xylene and xylene, ester-based organic solvent is ethyl acetate, butyl acetate And propyl acetate, the alcohol-based organic solvent is selected from isobutyl alcohol, propyl alcohol and butyl alcohol, and the ketone-based organic solvent is selected from methyl ethyl ketone, methyl propyl ketone and methyl isobutyl ketone. The method of claim 1 wherein the inert gas of 2) is Ar, Kr or Xe. The method of claim 1, wherein 2) O ₂ , N ₂ , NH ₃ , CH ₄ , C ₂ H _4, and And introducing a reactive gas selected from LPG by mixing. The method of claim 1, wherein the acrylic polyol of 3) is selected from ester type, ether type and polycarbonate polyol, the curing agent is selected from isopron diisocyanate, hydronated and methylene diisocyanate, the surface modifier is polyester-based , Selected from silicone and modified silicone, light stabilizer is a mixture of UV absorber and UV Hals, curing accelerator is selected from isocyanate, modified polyimide and peroxide, photosensitizer (quenching agent) is silica Selected from the group consisting of an aliphatic hydrocarbon aliphatic wax and a silica wax, an aromatic hydrocarbon-based organic solvent selected from toluene, xylene and xylene, an ester organic solvent selected from ethyl acetate, butyl acetate and propyl acetate, Organic solvents in methyl Ketones, characterized in that selected from the group consisting of methyl propyl ketone and methyl isobutyl ketone.