KR101224780B1 - Uv­curable primer composition for silver mirror coating - Google Patents

Abstract

The present invention provides a composition for forming a silver hard film comprising a bottom coat film-a silver (Ag) plated film-a (middle) top coat on a surface of a specific substrate, comprising: (a) a urethane (meth) acrylate oligomer; (b) silicon-based compounds; (c) mercaptan compounds; Provided are a UV curable undercoat composition for forming a silver film comprising the ultraviolet initiator and (e) an organic solvent, and a method for producing the silver film using the composition.
In the present invention, a novel UV-curable paint coating composition for forming a silver film is excellent in direct adhesion with a lower base material such as various plastic materials and a silver (Ag) plating film to be formed on the upper part and securing the physical properties thereof. By doing so, it is possible to increase excellent production workability, economy and mass productivity.

Description

UV curable undercoat composition for silver film formation {UV­CURABLE PRIMER COMPOSITION FOR SILVER MIRROR COATING}

The present invention can secure excellent adhesion and various physical properties with the lower base material and the upper silver (Ag) plated film, and can be cured quickly so that various coatings of the off-line and on-line methods can be performed. The present invention relates to a new UV curable undercoat composition that can be easily applied to a line.

Background Art Conventionally, as a method of imparting metallic luster to plastic molded products such as automobile interior and exterior materials and home appliance parts, a wet chromium plating and a dry vacuum deposition method are widely used. However, in the case of chromium plating, the toxic wastewater caused by hexavalent chromium is caused, and regulations are expanding around the world. In the case of vacuum deposition, productivity is low due to throughput limitations depending on facility investment cost and equipment size. As an alternative to this problem, a silver film coating and plating method using an environmentally friendly spray spray plating method has been proposed.

Spray-type silver film plating and painting method does not generate toxic waste water like chrome plating, and uses two-component spray spray plating method by dual gun and two head gun, and paints on the coating line of existing home appliances. It can be easily plated and painted in conjunction with. Therefore, many institutions at home and abroad and various companies are conducting research and development.

On the other hand, in order to secure the excellent appearance and required physical properties of the silver film product, it is very important to select the coating which is coated before the silver film coating, the coating of the film should be as smooth as possible, and the adhesion between the coating material and the silver film should be secured. do. In addition, when the hardening rate of the lower coating line during the production of the silver film product in the automatic continuous line is very long because the length of the continuous line is not secured, the development of the undercoat composition for silver curing film capable of fast curing is required.

However, most of the silver film coating products sold at home and abroad are coating products such as acrylic / urethane, alkyd / urethane, epoxy / amine or amide which are separated into two-component main parts / hardeners, and have a curing time of at least 30 minutes. As a result, there is a problem in economical line configuration. For example, when a silver film product is produced at a speed of 10 m / min, even when using a two-part type undercoat, the length of the hardened line reaches at least 300 m, resulting in a problem in economics as the line construction cost is high. On the other hand, when the hardening time of the undercoat is less than 30 minutes, a rainbow phenomenon and a blur appearance occur in the appearance of the silver film to be plated, resulting in product defects. In addition, since the viscosity of the two-part coating material mixed with the main part and the curing agent at a predetermined ratio increases gradually with time, there is a limit of pot life which becomes gel after use for a certain time and becomes unavailable. . Therefore, there is a problem that a deviation occurs in the appearance and physical properties of the initially painted product and the painted product after a lapse of time. Furthermore, even if the silver film plating is normally performed after the two-component thermosetting coating is applied, the adhesion between the coating and the silver film is good at the beginning, but after a certain time, the main part and the curing agent of the coating process continue to proceed at room temperature. As a result, shrinkage of the coat of the undercoat occurs, and thus there is a problem of change over time, in which adhesion of the undercoat and the silver film is poor.

In order to supplement the above problems of the two-component thermosetting paint, the photocuring paint, for example, an ultraviolet (UV) curing paint may be used. At this time, in order to secure the adhesion between the undercoat and the silver film, surface modification by plasma treatment was performed on the undercoat hardened film, and then the silver film coating was performed.However, in order to perform the plasma treatment, the coating material is separated from the coating line after manufacturing the undercoat film. It was difficult to apply except for the offline (OFF-LINE) method that is put into the coating line after the plasma treatment. In addition, safety problems such as a fire are caused.

In addition, there have been cases where the thermosetting powder coating has been developed as a undercoat, but since the curing temperature of the powder coating requires at least 150 ° C. or more, it is difficult to apply to materials such as plastic.

In view of the above-described problems, the inventors of the present invention provide a coating composition formed between a lower substrate and an upper silver (Ag) coating film, which is not only an ultraviolet curable type that can be cured rapidly but also between the substrate and the silver plating film. An object of the present invention is to develop a coating composition which is very excellent in adhesion and can secure various physical properties.

The present invention is based on this.

The present invention provides a composition for forming a silver hard film comprising a bottom coat film-a silver (Ag) plated film-a (middle) top coat film on a surface of a specific substrate, comprising: (a) a urethane (meth) acrylate oligomer; (b) silicon-based compounds; (c) mercaptan compounds; It provides the ultraviolet curable undercoat composition for silver film formation containing (d) an ultraviolet initiator and (e) an organic solvent.

In addition, the present invention (a) spraying the UV curable coating material composition for forming the silver film on the surface of the material to be applied, curing and drying to form a coating film; (b) forming a silver plating film on the formed undercoat; And (c) coating a curable coating material on the formed silver plated film and then drying to form a top coat or a middle coat and a top coat.

At this time, before or after any one of the steps (a) to (c), or may be injected into the distilled water, or after the injection of distilled water may include the step of removing the residue using high pressure air.

When producing a silver film coating product using the UV curable undercoat composition for silver film formation according to the present invention, a beautiful product appearance is ensured by excellent smoothness, and required by various industrial production products by excellent adhesion between the material and the silver film plating film. Its physical properties such as adhesion, corrosion resistance, durability, etc. are secured, and both on-line and off-line methods are applicable, which enables excellent production workability and economic efficiency according to mass productivity.

Hereinafter, the present invention will be described in detail.

In the present invention, the composite film including the undercoat film-the silver (Ag) plating film-the intermediate film and / or the overcoat film formed on a specific material (or substrate) will be referred to as "silver dura film".

Of the compositions for forming the silver film, the present invention is provided between the lower substrate and the upper silver plating film, and can exhibit excellent adhesion to these surfaces, respectively, and provides an ultraviolet curable undercoat coating composition capable of securing improved overall physical properties. Characterized in that.

<UV curing type undercoat composition for silver film formation>

The ultraviolet curable undercoat composition for silver film formation which concerns on this invention is a (a) urethane (meth) acrylate oligomer; (b) silicon-based compounds; (c) mercaptan compounds; (d) an ultraviolet initiator and (e) an organic solvent.

The 1st component which comprises the said ultraviolet curable paint composition is a urethane (meth) acrylate oligomer which belongs to an ultraviolet curable paint.

The urethane (meth) acrylate oligomer (a) of the present invention is a main resin for forming a coating film upon curing, and contains an unsaturated group, thereby easily forming a coating film by an ultraviolet curing reaction. In addition, it is possible to form a coating film of a flexible property can easily adsorb the ionized tin (Sn) component of the surface activator for silver hardener can exhibit excellent silver film expression and appearance properties. In addition, it is possible to exhibit excellent adhesion to the substrate (substrate), such as a plastic located in the lower portion of the undercoat due to the flexible properties. Furthermore, the plasma treatment operation and the like are unnecessary due to the excellent adhesion between the undercoat film and the silver plated film by using the urethane (meth) acrylate oligomer.

The urethane (meth) acrylate oligomer may be prepared as follows by reacting a diisocyanate compound, a polyol, and a hydroxyl-containing (meth) acrylate.

For example, a method of producing a urethane (meth) acrylate oligomer of the present application includes (i) reacting a diisocyanate compound with a polyol to synthesize a polyurethane prepolymer having an isocyanate group at both terminals, and having a hydroxyl group It can manufacture by making (meth) acrylate react. Or (ii) reacting a (meth) acrylate having a hydroxyl group with an excess of diisocyanate to synthesize a polyurethane prepolymer having an isocyanate group remaining at one end and then reacting the polyol thereto.

The diisocyanate compound may be a compound having two or more free isocyanate groups in one molecule. Non-limiting examples of diisocyanate compounds that can be used include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate , m-phenylenedi isocyanate, P-phenylenedi isocyanate, 4.4'-bisphenylenedi isocyanate, hexamethylene diisocyanate and derivatives; Aliphatic diisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, lysine diisocyanate and trimethylene diisocyanate; Alicyclic diisocyanates such as methylenebis (cyclohexyl isocyanate) and cyclohexane diisocyanate; Aromatic diisocyanates such as xylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate and biphenylene diisocyanate or mixtures of one or more thereof. Preferably aliphatic or cycloaliphatic diisocyanates; For example hexamethylene diisocyanate and derivatives, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, dicyclohexyl methane-4,4-diisocyanate, methylcyclohexane diisocyanate, trimethylhexamethylene di Isocyanates or mixtures thereof. The said compound can be used individually or in combination of 2 or more types.

As the polyol, conventional polyol compounds known in the art may be used. Aliphatic polyols can be used as an example, preferably aliphatic polyols in the range of C ₁ -C ₁₅ , more preferably C ₂ -C ₁₂ aliphatic polyols.

Non-limiting examples of polyols that can be used include neopentyl glycol, 3-methyl-1,5-pentanediol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,4-butanediol, 1, 6-hexanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,4-cyclohexanediol, 2,2-dimethyl-3-hydroxypropyl- Alkylene glycols such as 2,2-dimethyl-3-hydroxypropionate and 2,2,4-trimethyl-1,3-pentanediol; Aliphatic alcohols such as trimethylolpropane, pentaerythritol, tricyclodecanemethylol and bis- (hydroxymethyl) -cyclohexane; Polyester polyols obtained by the reaction of the aliphatic polyols with polybasic acids; Caprolactone alcohols obtained by the reaction of the aliphatic polyols with ε-caprolactone; Polycarbonate polyols such as polycarbonate diol which can be obtained by reaction of the aliphatic polyol (eg, 1,6-hexanediol) with diphenyl carbonate; Polyether polyols such as polytetramethylene ether glycol; Polycarbonate polyols such as glycerol, sorbitol, and polycarbonate diols; Polyether polyols such as polytetramethylene ether glycol; Glycerol, sorbitol, anitol, trimethylolethane, trimethylolpropane, trimethylolbutane, hexanetriol, dipentaerythritol trimethanolpropane, triethanolpropane or mixtures of one or more thereof have. In addition, the polyether polyols as polyethylene glycol, polypropylene glycol or polytetramethylene glycol, poly C ₁ -C ₆ alkylene glycol, and ethylene oxide-modified bisphenol, for example, the there may be mentioned ethylene oxide-modified bisphenol A .

At this time, the polyol is reacted with one or more compounds selected from the group consisting of i) 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol and tetraethylene glycol and diaryl carbonate Polycarbonate polyols formed, having a weight average molecular weight (Mw) in the range of 500-2000; And / or ii) ring opening polymerization of ε-caprolactone with at least one compound selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, diethylene glycol and neopentyl glycol, Preference is given to polycaprolactone polyols having a Mw) of from 500 to 3000.

At this time, the polybasic acid that can be used when forming the polyester polyol is a polybasic acid of C ₃ -C ₁₂ . Non-limiting examples thereof include succinic acid, phthalic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic anhydride, methyltetrahydrophthalic acid, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride, trimellitic acid, pyromellitic acid, Terephthalic acid, maleic acid, fumaric acid, itaconic acid, sebacic acid, dodecenyl succinic acid, benzoic acid, cyclohexadicarboxylic acid, citric acid, tall oil fatty acid or acid anhydrides thereof. The compounds mentioned above may be used alone or in combination of two or more thereof.

On the other hand, non-limiting examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy butyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxy alkyl (meth) acryloyl phosphate, 4-hydroxy cyclohexyl (meth) Acrylates or mixtures of one or more thereof.

The reactions of steps (i) and (ii) can be made according to conventional methods known in the art, wherein the reaction conditions of these reactions can also be controlled within conventional ranges.

After the reaction between the diisocyanate compound and the hydroxyl group-containing (meth) acrylate (or polyol), the isocyanate% may be measured in order to measure the reaction progress. At this time, when the isocyanate% reaches 0%, it can be determined that the reaction is completed.

The content of the urethane (meth) acrylate oligomer is not particularly limited, but may be 20 to 40 parts by weight based on 100 parts by weight of the ultraviolet curable undercoat composition of the present invention. In the above range, it is possible to maintain an appropriate coating viscosity (14 "to 16", FORD CUP # 4) to exhibit good coating characteristics, and to exhibit good coating drying characteristics during light curing, thereby blurring the appearance during the silver-plating process, Rainbow Problems such as occurrence do not occur.

The second component constituting the ultraviolet curable undercoat composition of the present invention is a silicone compound (b).

As described above, the silicon-based compound included in the undercoat can be fixed by a direct chemical bond such as a siloxane (-Si-O-) bond on the hydroxy group on the silver (Ag) plated film formed thereon. The adhesive force with the ultraviolet curable undercoat which is much superior to the silver film manufactured by the liquid preparation and the coating method can be exhibited.

Non-limiting examples of the silicone compound that can be used include silicates such as ethyl silicate and methyl silicate, silica sol, silicone monomers, mixtures of silanes, and hydrolyzates thereof. The silicone compound described above may be used alone or in combination of two or more thereof.

Specific examples of the silicone monomers and silanes include trimethoxy silane, triethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-glycidoxypropyl trimethoxysilane, and 3-glycidoxypropyl trie. Methoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, tri (2-butanone oxime) methylsilane, tri (2-butanone oxime) vinylsilane, hexamethyldisilane, aminopropyl triethoxysilane, amino Propyl trimethoxysilane, aminopropyl methyldimethoxysilane, mixtures thereof, or hydrolyzates thereof. The silicon compound may be a compound containing no mercaptan group.

The content of the silicone compound is not particularly limited, but may be 5 to 20 parts by weight based on 100 parts by weight of the ultraviolet curable paint coating composition of the present invention. If the above content range is satisfied, the adhesion stability between the UV-curable undercoat and the silver plated film is improved, and the rainbow phenomenon and the appearance of blur may not occur during plating of the silver film due to the UV curing reaction of the undercoat. have.

The third component constituting the ultraviolet curable undercoat composition according to the present invention is a mercaptan compound (c).

When the mercaptan compound is added to the UV-curable undercoat composition of the present application, a chemical bond is formed between the mercaptan compound of the undercoat film formed through the ultraviolet curing reaction and the silver plated film plated thereon, thereby being firmly fixed to the mercaptan compound. Ultraviolet curable undercoat with excellent adhesion can be produced.

Non-limiting examples of mercaptan compounds that can be used include mercaptoacetic acid, 3-mercaptopropionic acid, 11-mercaptoundecionic acid, thiophenol, diphenyldisulfide, N- (2-hydroethyl) mercaptoa Setamide, 1,2-ethanedithiol, and 2-mercapto ethanol, glycol bis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), glycol dimercaptoacetate, Octadecyl mercaptan, disetyl disulfide, octadecyl thioglycolate, 3-mercapto propyl triethoxysilane, 3-mercapto propyl trimethoxysilane, or mixtures of one or more thereof.

The amount of the mercaptan compound used may range from 0.5 parts by weight to 5 parts by weight with respect to 100 parts by weight of the ultraviolet curable undercoat composition of the present invention, but is not particularly limited thereto.

The fourth component constituting the ultraviolet curable undercoat composition according to the present invention is the ultraviolet initiator (d).

As such a UV initiator, a material capable of absorbing an ultraviolet wavelength in the range of 230 nm to 390 nm, and compounds commonly known in the art such as benzoin esters, benzyl ketals, ketones, etc. may be used without limitation.

The content range of the UV initiator may be in the range of 1 to 5 parts by weight, and preferably in the range of 2 to 5 parts by weight based on 100 parts by weight of the ultraviolet curable undercoat composition of the present invention. If the content range is satisfied, poor adhesion or poor adhesion due to overcure will not occur.

The fifth component constituting the UV curable undercoat composition according to the present invention is an organic solvent (e) commonly used in the art.

The organic solvent not only uniformly mixes the elements constituting the composition, but also maintains the necessary viscosity during spray coating, and serves to stably dissolve resins, oligomers, monomers, etc. constituting the coating composition according to the present invention. .

Non-limiting examples of organic solvents that can be used include aromatic hydrocarbons, ester solvents, ether solvents, ketone solvents, acetate solvents or mixtures thereof. Hydrocarbon-based solvents, or ester-based solvents and ether-based solvents may be appropriately selected for possible workability and storage property in order to prevent uniform smoothness during uniform coating curing or spray coating.

The content of the organic solvent may be in the range of the remaining amount to satisfy 100 parts by weight of the total UV curable paint composition, for example 20 to 30 parts by weight relative to 100 parts by weight of the UV curable paint composition.

In addition to the above components, the ultraviolet curable undercoat composition of the present invention may further include a monomer, a polyfunctional oligomer, an acrylic resin, a coating film leveling agent, other additives, or the like alone or in combination.

The monomer (f) may not only assist the formation of the coating film according to the curing reaction, but also may serve to lower the viscosity when included in the ultraviolet curable undercoat composition according to the present invention.

As a monomer which can be used, the conventional monomer known in the art can be used without limitation, Preferably it contains three or more curable unsaturated functional groups. Non-limiting examples thereof include trimethylolpropanetriacrylate, ethylhexyl acrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, hexanediol diacrylate, neopentylglycol diacrylate, isobornyl acrylate , Hydroxypropyl acrylate or mixtures of one or more thereof. The content range of the above-described monomers is not particularly limited, but may be in the range of 5 to 20 parts by weight based on 100 parts by weight of the ultraviolet curable paint coating composition of the present invention.

As the multifunctional oligomer (g), conventional materials known in the art including three or more unsaturated functional groups may be used. As such, when the polyfunctional oligomer is mixed with the monomer (f), the decrease in adhesion to the substrate due to the high shrinkage of the monomer during the curing reaction can be alleviated to improve the adhesion to the substrate.

Non-limiting examples of polyfunctional oligomers that can be used include EBECRYL 1290 (Cytec, 6-functional oligomer), MIRAMER PU-340 (Miwon Corporation, 3 polyfunctional oligomer), UA-8560TL (HS Chemtron, 6-functional oligomers]. The content of the multifunctional oligomer is not particularly limited, but may be in the range of 5 to 15 parts by weight based on 100 parts by weight of the ultraviolet curable paint coating composition of the present invention. At this time, the weight average molecular weight (Mw) of the multifunctional oligomer may be 1000 or more, preferably 1000 to 5000 range. Moreover, it is appropriate that there are three or more unsaturated functional groups.

As the acrylic resin (h), a conventional acrylic resin known in the art may be used. The acrylic resin that can be used includes a glass transition temperature (T _g ) of 40 ° C. or higher, preferably 40 to 100 ° C., a molecular weight (Mw) of 3,000 or higher, preferably 3,000 to 5000, without including an unsaturated functional group. It is preferable that acid value, hydroxyl value, and amine value are 1 or more and 10 or less, respectively. Examples include PARALOID A-21 (DOW) and PARALOID B-44 (DOW).

Since the acrylic resin has no photoinitiation effect due to light, shrinkage may be prevented during the curing reaction. Therefore, it can be added to prevent the shrinkage of the coating film due to excessive curing during the ultraviolet curing reaction and the resulting film peeling, thereby improving the adhesion to the substrate.

The content of the acrylic resin may be in the range of 5 to 10 parts by weight based on 100 parts by weight of the ultraviolet curable paint coating composition of the present invention, but is not limited thereto.

In addition, the coating film leveling agent (i) can use a general coating film leveling agent known in the art, such as a polyether modified siloxane type, a polydimethylsiloxane type, a polyacrylate type, or one or more mixtures thereof, without limitation.

At this time, the content of the coating film leveling agent is not particularly limited, but may be in the range of 0.01 to 0.05 parts by weight based on 100 parts by weight of the UV curable paint coating composition.

In addition to the above components, the UV curable undercoat composition for forming a silver film of the present invention may additionally contain any additives added to the paint, such as surface modifiers, viscosity modifiers, thickeners, antioxidants, sunscreens, antifoams, and the like. . These additives may be added to the UV curable undercoat compositions as content ranges known in the art.

The ultraviolet curable undercoat composition for forming a silver film according to the present invention comprises the aforementioned components, such as a urethane (meth) acrylate oligomer, a silicone-based compound, a mercaptan compound, an ultraviolet initiator, and an organic solvent. It can be manufactured by mixing and stirring a polyfunctional oligomer, an acrylic resin, a coating film leveling agent, etc. alone or in combination.

Since the ultraviolet curable undercoat composition for silver hard film formation comprised as mentioned above contains an unsaturated group, coating film formation by an ultraviolet curing reaction can be easily made. In addition, it is possible to form a flexible coating film to easily adsorb the ionized tin (Sn) component of the surface active agent for silver hardeners can exhibit excellent silver film expression and appearance characteristics, through which silver (Ag) plated on the upper layer ) It is possible to give the primary adhesion performance with the plating film.

In addition, the adhesion of the undercoat film and the silver plating film is improved by the use of the silicon-based compound, thereby securing the required physical properties of the industrial mass production level of the silver film coating product. In addition, the use of the mercaptan compound may increase the adhesion described above.

<Silver film manufacturing method>

In the present invention, the spray-type silver film can be manufactured according to a conventional method known in the art using the above-mentioned UV curable undercoat composition for forming a silver film.

Hereinafter, one preferable embodiment of the said silver film production method is shown below. However, the present invention is not limited thereto.

1) After spraying the ultraviolet curable undercoat composition of the present application on the surface of the material to be applied, it is cured and dried to form an ultraviolet curable type such as an ultraviolet (UV) undercoat.

The material or substrate on which the silver film is to be formed is not particularly limited, and examples thereof include metal, wood, ceramic, PC, plastic such as ABS, interior and exterior building materials, and the like. In addition to the materials described above, as long as the silver film can be formed, these components, forms and the like are not particularly limited.

Prior to forming the UV undercoat, the substrate may be subjected to a pretreatment step. At this time, the pretreatment method may be carried out according to a conventional method known in the art, it is not particularly limited. For example, using a solvent, ultrasonic waves, high pressure air, etc. to remove foreign material surface, bends, grooves, clean up and pretreatment.

For example, the UV undercoat film forming step may be performed by spray-coating an ultraviolet (UV) curable undercoat, irradiating IR at a tunnel line (50 to 80 ° C., 3 to 5 minutes), and performing curing drying in a UV drying furnace. (800-2000 mJ / cm <2>) can form a smooth undercoat (15-25 micrometers).

(2) A silver (Ag) plating film is formed on the formed undercoat.

Prior to forming the silver plating film, the surface activation composition may be sprayed onto the undercoat to perform surface treatment. When the surface treatment is performed in this way, the surface of the undercoat film is changed to a sensitive state so that the silver plating can be performed, thereby serving to perform the silver plating continuously.

On the lower surface-treated film, the silver-containing composition and the reducing agent composition may be sprayed at the same time to form a silver plated film. For example, the silver plating film forming step may include distilled water dilution solution of silver nitrate solution and distilled water dilution solution of reducing agent composition at the same time in a volume ratio of 1: 1 using a dual head, two head spray gun. Perform the spray. After the activated silver plated film is formed on the washed undercoat, distilled water may be sprayed again with an air spray to wash the silver mirror surface residue and foreign matter.

If necessary, after spraying a post-treatment liquid which removes foreign matters such as silver reaction reaction by-products and incomplete reactants on the formed silver plated film, the distilled water may be sprayed again with air spray to wash all residues on the silver surface. have.

(3) After coating the curable coating material on the formed silver plating film, it is dried to form a top coat or a middle coat and a top coat.

At this time, the (middle) top coat may be formed on the silver plating film alone, or both the middle coat and the top coat may be formed.

For example, an acrylic two-component transparent paint or various color dyes or transparent nano dispersion pigments may be added to the dried silver plating film to form a transparent coating. After spray coating, it may be dried in a hot air oven at 50 to 80 ° C. for 5 to 20 minutes to form a smooth intermediate film (15 to 25 μm).

Or coat an acrylic two-component or UV curable transparent paint on the intermediate coating surface formed as described above. At this time, acrylic two-component paint can be first dried in 50 ~ 80 ℃ tunnel hot air oven for 5 ~ 20 minutes and then transferred to 50 ~ 80 ℃ batch oven for curing for 2 ~ 3 hours. UV curable transparent paint is tunnel type line After irradiating IR at (50 to 80 ° C., 3 to 5 minutes), curing drying in a UV drying furnace (1000 to 2000 mJ / cm 2) may be performed to form a smooth top transparent coating film (20 to 30 μm).

It may include the step of spraying with distilled water before, after, or between any one of the steps (a) to (c), or removing the residue using high pressure air after the distilled water injection. For example, by blowing with high-pressure air (air) to shake off the distilled water remaining on the surface of the coating film, it can be dried for 5 to 20 minutes in a 50 ~ 80 ℃ tunnel-type hot air oven, wherein the pressure of the high-pressure air is 1 ~ 4 It may range from kgf / cm 2.

The UV curable undercoat composition for forming a silver film according to the present invention has excellent adhesion with various materials including plastics, wood, ceramics such as PC, ABS, and silver film coated on the surface of the undercoat when coating the undercoat. Do.

After painting and drying, silver plating can be performed without additional processing steps such as plasma treatment, and various properties required by industrial products such as adhesion between substrate and undercoat, adhesion between underpass and silver plating film, and durability can be secured. (See Table 1 below). Moreover, it has beautiful coating film smoothness and gloss, and can achieve the desired appearance quality by silver film plating. Furthermore, it is possible to build-up by fast curing by UV curing method, so that it is possible to construct an on-line coating line where manufacturing steps are continuously performed in one coating line, including offline method, and various silver film plating industrial products such as mobile phones and home appliance cases. Can be mass produced continuously. In fact, it can be confirmed that the silver film prepared in the present invention has good physical properties in all items requiring reliability (see Table 2).

Hereinafter, the present invention will be described in detail with reference to Examples, but the following Examples and Experimental Examples are merely illustrative of one embodiment of the present invention, and the scope of the present invention is not limited to the following Examples and Experimental Examples.

Preparation Example 1. Preparation of urethane (meth) acrylate oligomer (A)

Two equivalents of isophorone diisocyanate were added to a four-necked flask equipped with a thermometer, a condenser, a dropping funnel, and a stirrer, and 500 ppm of hydroquinone, a polymerization inhibitor, was added. After raising the temperature to 60 ° C, 1 equivalent of polycarbonate polyol (reactant of 1,6-hexanediol and diphenylcarbonate, weight average molecular weight Mw = 1000) was added dropwise, and the reaction was maintained at 70 ° C for 1 hour. When the theoretical NCO% was reached, 1 equivalent of 2-hydroxy propyl acrylate was added dropwise for 1 hour, and then 100 ppm of dibutyltin dilaurate was added, and the temperature was raised to 80 ° C. to maintain the reaction for 4 hours. After confirming that there was no NCO peak by infrared spectrophotometry (IR), it cooled to 60 degreeC and prepared the urethane (meth) acrylate oligomer (A).

Preparation Example 2 Preparation of Urethane (meth) acrylate Oligomer (B)

A urethane (meth) acrylate oligomer (B) was prepared in the same manner as in Preparation Example 1, except that hexamethylene diisocyanate was used in the same amount instead of isophorone diisocyanate.

Preparation Example 3 Preparation of Urethane (meth) acrylate Oligomer (C)

Polyurethane (meth) acrylic acid using the same method as Preparation Example 1, except that polycaprolactone polyol (reactant of neopentyl glycol and ε-caprolactone, molecular weight 1000) was used in the same equivalent instead of polycarbonate polyol. The rate oligomer (C) was prepared.

Example  1. Preparation of UV curable undercoat composition (A-1)

10 parts by weight of toluene, 5 parts by weight of ethyl acetate, 8 parts by weight of solvent MIBK (Methyl Isobutyl ketone), 3 parts by weight of UV initiator IRGACURE 184 (manufacturer: CIBA), 0.7 parts by weight of IRGACURE 907 (manufacturer: CIBA) After the addition, the mixture was stirred and dissolved uniformly.

After slowly adding 30 parts by weight of the urethane (meth) acrylate oligomer (A) prepared in Preparation Example 1 while stirring, 3 parts by weight of MIRAMER PU-340 (manufactured by Miwon Co., Ltd., multifunctional oligomer), UA-8560TL (manufacturer) : 5 parts by weight of HS chemtron, polyfunctional oligomer), 10 parts by weight of trimethylolpropane triacrylate, and 7 parts by weight of PARALOID B40 (manufacturer: DOW, acrylic resin) were added to dissolve uniformly. Then, 5 parts by weight of tetramethoxysilicate as a silicon compound, 10 parts by weight of 3-glycidoxypropyl triethoxysilane and 3 parts by weight of 3-mercaptopropionic acid as a mercaptan compound were added, and BYK 306 (manufacturer as a film smoothing agent) was prepared. : BYK) 0.3 parts by weight of the solution was added and then stirred uniformly to prepare an ultraviolet curable undercoat composition (A-1) for silver film.

Example  2. Preparation of UV curable undercoat composition (B-1)

Using the same method as in Example 1, except that the urethane (meth) acrylate oligomer (B) prepared in Preparation Example 2 was used instead of the urethane (meth) acrylate oligomer (A) prepared in Preparation Example 1. The ultraviolet curable undercoat composition (B-1) for silver film was manufactured.

Example  3. Preparation of UV curable undercoat composition (C-1)

Using the same method as in Example 1, except that the urethane (meth) acrylate oligomer (C) prepared in Preparation Example 3 was used instead of the urethane (meth) acrylate oligomer (A) prepared in Preparation Example 1. The ultraviolet curable undercoat composition (C-1) for silver film was manufactured.

Example 4 Preparation of Silver Film Coating Specimen

1) PC / ABS composite plastic material (7cm × 7cm) was surface-washed with isopropyl alcohol, and surface massage was performed with vibration damping gloves to pretreat the material.

2) Spray the ultraviolet (UV) curable undercoat of Examples 1 to 3 onto the pretreated material, irradiate with IR (60 ° C, 3 minutes), and perform curing drying in a tunnel type UV drying furnace (1600 mJ / ㎠ ) To form a smooth undercoat (20 μm).

3) Spray 2% dilution of distilled water of surface activator (Product name: MagicSilver AC1020, manufacturer: Samwha Paint) onto the coating surface by spraying the surface activation treatment on the surface of the coating film, and then spray spraying distilled water on the surface treatment liquid again. The residue was washed.

4) Double-necked dilution of 4% distilled water of silver solution (Product Name: Magic Silver SN1040, Manufacturer: Samwha Paint) and 12% dilution solution of distilled water of Reducing Agent (Product Name: Magic Silver RD1080, Manufacturer: Samwha Paint) (Dual Gun, Two head spray gun) was used to simultaneously perform air spraying at a volume ratio of 1: 1 to form a silver film. Thereafter, distilled water was sprayed again with air spray to wash foreign matter residues on the surface of the silver film.

5) After-treatment agent (Product Name: Magic Silver ST1040, Manufacturer: Samwha Paint) was sprayed with 4% diluent of distilled water to wash the silver film. Then, distilled water was sprayed with air spray to remove all residues on the silver film surface. Water washing was performed.

6) A high pressure air of 1 to 4 kgf / cm 2 was injected onto the washed silver film surface to shake off distilled water remaining on the silver film surface, and then dried in an 80 ° C. tunnel hot air oven for 10 minutes.

7) Spray the acrylic silver two-component transparent coating on the dried silver film surface [Product name: Magic Silver SM2100 (Part A): 2200 (Part B) = 10: 1 (Weight)), Manufacturer: Samwha Paint Industry Co., Ltd. Then, it was dried for 10 minutes in an 80 ℃ hot air oven to form a smooth intermediate film (15 ㎛).

8) Apply UV curable transparent paint (Product Name: Magic Silver SM4300, Manufacturer: Samwha Paint Industry) on the intermediate coating surface, irradiate IR at tunnel line (60 ℃, 3 minutes), and then perform curing drying in UV drying furnace ( 1000 mJ / cm 2) to form a smooth top transparent coating film (25 μm) to prepare a silver film coating specimen.

Comparative Example 1. Preparation of UV curable undercoat composition (D)

A UV curable undercoat composition (D-1) was prepared by the same method as Example 1 except that 3 parts by weight of 3-mercaptopropionic acid of Preparation Example 1 was used and 8 parts by weight of ethyl acetate was used. And, the same method as in Example 4 was carried out to prepare a silver film specimen (D-2).

Comparative Example 2. Preparation of UV curable undercoat composition (E)

Except for using 3 parts by weight of 3-mercaptopropionic acid of Preparation Example 1, 13 parts by weight of 3-glycidoxy propyl triethoxysilane was carried out in the same manner as in Example 1 for the silver film UV curable undercoat composition (E-1) was prepared, and the same procedure as in Example 4 was carried out to prepare a silver film specimen (E-2).

Experimental Example 1. Comparative evaluation of physical properties of silver film specimens coated with UV curable undercoat composition for silver film

According to the method of Example 4, the ultraviolet curable undercoat compositions (A-1), (B-1) and (C-1) for the silver film of the Examples 1 to 3 were prepared according to the method of Example 4 (A-2), ( B-2) and (C-2) were each produced and the reliability test was done. As the control group, silver film specimens (D-2) and (E-2) were prepared using the undercoat compositions of Comparative Example 1 and Comparative Example 2, respectively, and subjected to a reliability test.

As a result, silver film specimens (A-2), (B-2), and (C-2) prepared from the compositions of Examples 1 to 3 of the present application were generally good in appearance, adhesion, hot water resistance, and the like. The silver film specimens (D-2) and (E-2) prepared from the undercoat compositions of Comparative Example 1 and Comparative Example 2 were found to have very low reliability (see Table 1 below).

Experimental Example  2. Silver curtain  UV curable undercoat composition Painted Silver curtain  Evaluation of the Physical Properties of the Specimen

Silver film specimens (A-2), (B-2), (C) using the ultraviolet curable undercoat compositions (A-1), (B-1), and (C-1) for the silver film of Examples 1 to 3, respectively. -2) was fabricated and then tested for reliability as shown in Table 2 below.

As a result of the experiment, it was found that the silver film-coated specimens prepared using the undercoat composition prepared according to the method of the present invention showed good results in all items (see Table 2 below).

As a result, by using the UV-curable undercoat composition for silver film of the present invention, all problems caused by using the conventional two-component thermosetting undercoat have been solved, and the surface modification process such as plasma treatment is not necessary, which is not only safe for fire, but also continuous. It was confirmed that it was optimized for the on-line production method that consists of regular paint lines.

responsibility
Item Test Methods Criteria Example 1
(A-2) Example 2
(B-2) Example 3
(C-2) Exterior Metallic feeling is clear and there should be no appearance defect such as haze, black side No abnormality Good Good Good Adhesion 1mm Cross Cut, 5 Taps No peeling Good Good Good Salt water spray resistance 5% NaOH, 35 ℃, 100hrs exposure → washing with water and removing water → left at room temperature for 1 hour, 2mm cross cut, taping once Appearance and Attachment
No problem Good Good Good Acid resistance pH 4.6 solution 48Hrs Precipitate → washing with water and removing water → standing at room temperature for 1 hour, 2mm cross cut, taping once Appearance and Attachment
No problem Good Good Good Impact resistance 500 g, 50 cm, 6 drops once Like glass
Not broken Good Good Good Wear resistance 500g load applied to the eraser → 1500 round trips (40 round trips / min) to the film surface Do not peel off Good Good Good RCA wear RCA wear tester, paper should be 275g or more than 30 times (33 times / min) No base metal exposure Good Good Good Surface hardness Mitsubishi Uni, 10 mm  (No Scratch in F) Good Good Good Cosmetic resistance Sunscreen Cream (NIVEA, SPF30)
→ 80 ℃, 80% thermostat 24hr exposure
→ 1 hour at room temperature, 2mm Cross Cut, 1 time taping Attachment failure
No Good Good Good UV resistance UV B, 20cm, 72hrs → stand at room temperature for 4 hours, 2mm cross cut, taping once Appearance and Attachment
No problem Good Good Good Moisture resistance 60 ℃, 95% chamber 72hrs → left at room temperature for 1 hour, 2mm cross cut, taping once Appearance and Attachment
No problem Good Good Good Thermal shock resistance (-) 40 ℃, 2hrs → 85 ℃ 2hrs → Leave at room temperature for 1 hour, 2mm Cross Cut, Taping once Appearance and Attachment
No problem Good Good Good

Claims (13)

In the composition which forms the silver film containing a undercoat film-silver (Ag) plating film-(middle) topcoat film on the surface of a specific base material,
(a) urethane (meth) acrylate oligomers;
(b) silicon-based compounds;
(c) mercaptan compounds;
(d) ultraviolet initiators; And
(e) organic solvent
Ultraviolet curable undercoat composition for silver film formation containing a. The method of claim 1, wherein the urethane (meth) acrylate oligomer
(i) reacting a diisocyanate compound with a polyol to synthesize a polyurethane prepolymer containing an isocyanate group at both ends, and reacting the synthesized polyurethane prepolymer with a (meth) acrylate having a hydroxyl group, or
(ii) forming a silver film by reacting a (meth) acrylate having a hydroxyl group with a diisocyanate compound to synthesize a prepolymer having an isocyanate group remaining at one end thereof, and reacting the synthesized prepolymer and a polyol. UV curable undercoat composition. The isocyanate compound according to claim 2, wherein the isocyanate compound is hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate, dicyclohexyl methane-4,4-diisocyanate, methylcyclohexane diisocyanate. An ultraviolet curable undercoat composition for forming a silver film, characterized in that it is selected from the group consisting of isocyanate and trimethylhexamethylene diisocyanate. The polyol of claim 2, wherein the polyol reacts with at least one compound selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol and tetraethylene glycol and a diaryl carbonate. UV-curable undercoat composition for silver film formation, which is formed by forming a polycarbonate polyol having a weight average molecular weight (Mw) of 500 to 2000. The polyol of claim 2, wherein the polyol is formed by ring-opening polymerization of ε-caprolactone with at least one compound selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, diethylene glycol and neopentyl glycol, The ultraviolet curable undercoat composition for silver film formation which is characterized by being a polycaprolactone polyol whose average molecular weight (Mw) is 500-3000. The hydroxyl group-containing (meth) acrylate of claim 2 is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy. With oxy-3-phenyloxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxy alkyl (meth) acryloylphosphate and 4-hydroxycyclohexyl (meth) acrylate The ultraviolet curable undercoat composition for silver film formation which is characterized by being selected from the group which comprised. The method of claim 1, wherein the silicon compound is trimethoxy silane, triethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxy Silane, phenyltrimethoxysilane, vinyltrimethoxysilane, tri (2-butanone oxime) methylsilane, tri (2-butanone oxime) vinylsilane, hexamethyldisilane, aminopropyl triethoxysilane, aminopropyl An ultraviolet curable undercoat composition for forming a silver film, which is selected from the group consisting of trimethoxysilane and aminopropyl methyldimethoxysilane. The method of claim 1, wherein the mercaptan compound is mercapto acetic acid, 3-mercaptopropionic acid, 11-mercapto-undecyl acid, thiophenol, diphenyl disulfide, N- (2-hydroethyl) mercaptoacet Amide, 1,2-ethanedithiol, and 3-mercaptopropyl trimethoxysilane, glycol bis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), 2-mercapto Ethanol, glycol dimercaptoacetate, octadecyl mercaptan, disetyl disulfide and octadecyl thioglycolate, 3-mercapto propyl triethoxysilane, 3-mercapto propyl trimethoxysilane Ultraviolet curing type undercoat composition. The method of claim 1, wherein the composition further comprises at least one compound selected from the group consisting of monomers, polyfunctional oligomers, acrylic resins and coating film leveling agents, UV curable undercoat composition for forming a silver film. The method of claim 9, wherein the monomer is trimethylolpropane triacrylate, ethylhexyl acrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, iso An ultraviolet curable undercoat composition for forming a silver film, which is selected from the group consisting of carbonyl acrylate and hydroxypropyl acrylate. The method of claim 9, wherein the UV curable undercoat composition is compared to 100 parts by weight of the composition
(a) 20 to 40 parts by weight of urethane (meth) acrylate oligomer;
(b) 5 to 20 parts by weight of the silicone compound;
(c) 0.5 to 5 parts by weight of the mercaptan compound;
(d) 1 to 5 parts by weight of an ultraviolet initiator;
(e) a residual organic solvent that satisfies 100 parts by weight of the composition;
(f) 5 to 20 parts by weight of monomers;
(g) 5 to 15 parts by weight of a multifunctional oligomer;
(h) 5 to 10 parts by weight of acrylic resin; And
(i) 0.01-0.05 weight part of coating film leveling agents
UV-curable undercoat composition for silver film formation, characterized in that it comprises a. (a) spraying the ultraviolet curable undercoat composition according to any one of claims 1 to 11 onto the surface of the material to be applied, followed by curing and drying to form a undercoat;
(b) forming a silver plating film on the formed undercoat; And
(c) coating a curable coating material on the formed silver plated film and then drying to form a top coat or a middle coat and a top coat. The method of claim 12, wherein the method is sprayed with distilled water before, after, or between any one of the steps (a) to (c), or the residue is removed using high pressure air after the distilled water is sprayed. Method for producing a silver film comprising the step of.