JP4480408B2 - Coating composition for silver plating and method for producing the same - Google Patents

Description

  The present invention relates to an ultraviolet curable coating composition for silver plating, which is excellent in the hardness of the coating film, the adhesion between the silver plating film and the transparency, and a method for producing the same.

The chemical plating method using the silver mirror reaction is a well-known method from the past. Since a silver plating film can be obtained by a simple method, various chemicals and methods have been improved. For example, by having a three-layer structure of a primer layer called an undercoat layer laminated on a base material, a silver plating layer laminated on the primer layer by a silver mirror reaction, and a top coat layer laminated on the silver plating layer, A method for obtaining a silver-plated laminate with high designability is disclosed. (For example, see Patent Document 1 and Patent Document 2)
However, the silver-plated laminate obtained by such a method has a problem that the adhesion between the layers is insufficient and the hardness of the topcoat layer is insufficient, so that only limited applications can be applied. there were. Furthermore, since it takes time to cure the undercoat layer and the topcoat layer, there is a problem that the production efficiency is also poor.

In such a situation, a method using an ultraviolet curable resin has been proposed for the problem of the hardness and the curing speed of the coating. For example, a method of obtaining a high hardness film by a method of blending colloidal silica with an ultraviolet curable resin is disclosed. (For example, see Patent Document 3)
However, according to the method described in Patent Document 3, there is a problem that colloidal silica aggregates in the ultraviolet curable resin, thereby causing haze in the cured coating.

In order to solve such problems, a method for obtaining an ultraviolet curable coating composition in which colloidal silica surface-modified with mercaptosilane is blended with a polyfunctional compound that is cured by ultraviolet rays is disclosed. (For example, see Patent Document 4)
According to this method, this mercaptosilane-modified colloidal silica has been found to improve the hardness and transparency of the cured coating because the compatibility with the polyfunctional compound is improved by the mercapto group on the surface. ing.
However, this technique mainly improves the abrasion resistance and transparency of the coating film, and no technique has been proposed for improving the adhesion between the coating film and a metal such as a plating film. Furthermore, even if the technique of the cited document 4 is applied as a coating composition for silver plating, peeling from the silver plating film, that is, adhesion is not improved. Also, the appearance of the coating composition is not preferable because the silver plating film is slightly white.

Japanese Patent Laid-Open No. 10-309774 Japanese Patent Laid-Open No. 11-250702 JP 61-181809 JP Japanese Patent Laid-Open No. 10-81839

  In order to solve the above-mentioned problems, that is, the adhesion and hardness of the coating film for silver plating are excellent, the curing rate at the time of film formation is high, and a silver plating film with excellent aesthetics can be obtained. In order to obtain a coating composition for silver plating that can be applied to both the coat layer and the top coat layer, the present inventors have made extensive studies.

  As a result, the resin composition obtained by the reaction of tetraalkoxysilane or a partial condensate thereof, a silane compound having a mercapto group, and a radical polymerizable compound having at least one carbon-carbon double bond is described above. It has been found that the present invention can be used as an excellent coating composition for silver plating that solves the above problem, and the present invention has been completed based on such knowledge.

That is, in the present invention, after reacting a tetraalkoxysilane represented by the following general formula (Chemical Formula 1) or a partial condensate thereof (a) with a silane compound (b) having a mercapto group, at least one of them is reacted. Add the radically polymerizable compound (c) having the above carbon-carbon double bond , or hydrolyze (a) and (b), or together, and then add (c) to this. The manufacturing method of the coating composition for silver plating characterized by these .

Furthermore, this invention relates to the coating composition for silver plating obtained by the said manufacturing method .

The coating composition for silver plating of the present invention is such that both the tetraalkoxysilane or its partial condensate (a) and the silane compound (b) having a mercapto group react with the radical polymerizable compound (c). The adhesion of the coating film is remarkably excellent. In addition, when this silver plating coating composition is used as an undercoat layer, the use of tetraalkoxysilane or a partial condensate thereof (a) is more effective than the case where a silica sol is used. The silver plating film which improves adhesiveness and has the more outstanding aesthetics can be created.
In addition, since the coating composition for silver plating of the present invention is excellent in film adhesion and hardness, has a fast curing speed during film formation, and is excellent in film transparency, the undercoat layer and top coat for silver plating It has the advantage that it can be applied to any of the layers.

  The first component of the composition of the present invention is tetraalkoxysilane or a partial condensate (a) thereof, which is a compound represented by the following general formula (Formula 2).

Examples of such tetraalkoxysilane or a partial condensate thereof include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Examples of the partial condensate of tetraalkoxysilane include silicate 40 (manufactured by Tama Chemical Industry Co., Ltd.), M silicate 51 (manufactured by Tama Chemical Industry Co., Ltd.), and the like. In the present invention, one or more compounds selected from these may be used in combination.
Further, in the present invention, of these tetraalkoxysilanes or partial condensates thereof, use of silicate 40 or M silicate 51, which is a partial condensate of tetraalkoxysilane, is most preferable in terms of reactivity and coating film strength.

  Next, the 2nd component of this invention composition is a silane compound (b) which has a mercapto group, and it is preferable to use what is represented by the following general formula (Formula 3).

Examples of the silane compound (b) represented by the general formula (Chemical Formula 3) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltripropoxysilane, and 3-mercaptopropylmethyl. Dimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-mercaptopropylmethyldipropoxysilane, 3-mercaptopropyldimethylmethoxysilane, 4-mercaptobutyltrimethoxysilane, 4-mercaptobutyltriethoxylane, 4-mercaptobutyltri Propoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 2-mercaptoethyltripropoxysilane, bis (3-mercaptopropyl) dimethoxysilane, tris (3-mercaptopropyl) methoxy Silane etc. are mentioned. Moreover, these compounds can also be used combining 1 type or multiple types of a compound.
In the present invention, among these silane compounds, use of 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane is most preferable in terms of reactivity and coating film strength.

Next, the third component of the present invention is a radical polymerizable compound (c) having at least one or more carbon-carbon double bonds. Although the number of carbon-carbon double bonds in one molecule of this compound is one or more, the hardness of the film formed by the reaction increases as the number of double bonds increases, but the film tends to become brittle. It is in.
Therefore, the number of carbon-carbon double bonds is most preferably 3-6.
However, in order to impart flexibility to the film to be formed, a radical polymerizable compound having 1 to 2 carbon-carbon double bonds may be used in combination.

Examples of such radically polymerizable compounds include acrylate monomers, methacrylate monomers, epoxy acrylate oligomers, epoxy methacrylate oligomers, urethane acrylate oligomers, urethane methacrylate oligomers, silicone acrylate oligomers, and silicone methacrylate oligomers.
However, among these radically polymerizable compounds, the use of an acrylate monomer, a methacrylate monomer, a urethane acrylate oligomer, and a urethane methacrylate oligomer is most suitable for exerting the performance of the coating composition of the present invention.
The acrylate monomer and methacrylate monomer have carbon-carbon double bonds, urethane acrylate oligomers, and urethane methacrylate oligomers have carbon-carbon double bonds and urethane bonds, but additionally have various functional groups and bonds. May be. Examples of such various functional groups and bonds include a hydroxyl group, a carboxyl group, a phenyl group, a thiol group, a phosphate group, an epoxy group, a halogen, an ether bond, and an ester bond.

Examples of acrylate monomers, methacrylate monomers, urethane acrylate oligomers and urethane methacrylate oligomers that can be used in the present invention are shown below.
As acrylate monomers, 2-ethylhexyl acrylate, lauryl acrylate, isooctyl acrylate, isostearyl acrylate, cyclohexyl acrylate, tricyclodecanyl acrylate, tricyclodecanyloxyethyl acrylate, isobornyl acrylate, ethyl carbitol Acrylate, 2-ethylhexyl carbitol acrylate, methoxypropylene monoacrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, benzyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxydiethylene glycol Acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxye Tyl acrylate, phthalic anhydride-2-ethylhexyl acrylate adduct, tetrahydrophthalic anhydride-2-hydroxypropyl acrylate adduct, hexahydrophthalic anhydride-2-hydroxypropyl acrylate adduct, 1,3-butanediol di Acrylate, 1,4-butane diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol F diacrylate, ethoxylated 1,6-hexanediol diacrylate, propoxylated 1, 6-hexanediol diacrylate, ethoxylated neopentyl glycol diacrylate, neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate, 1,6-hexanediylbis [oxy (2-hydroxy Propane-1,3diyl)] diacrylate, [2- [1,1-dimethyl-2-acryloyloxyethyl] -5-ethyl-1,3-dioxane-5-yl] methyl acrylate, 3- [2 , 2-dimethyl-1-oxo-3-acryloyloxypropoxy] -2,2-dimethylpropyl acrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, Ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetra Chryrate, dipentaerythritol hydroxypentaacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol triacrylate, dipentaerythritol hexaacrylate, 2-isocyanate ethyl acrylate, imide acrylate, bisphenol S dithiol acrylate, tetra Examples thereof include bromobisphenol A acrylate, fluorine acrylate, trisacryloyloxyethyl phosphate, 3-acryloyloxypropanoic acid, and 3- (tetramethoxysilyl) propyl acrylate.

  Further, as the methacrylate monomer, tetrahydrofurfuryl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, 2-phenoxyethyl methacrylate, polypropylene glycol monomethacrylate, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, neopentyl dimethacrylate, Examples include ethoxylated bisphenol A dimethacrylate, trimethylolpropane trimethacrylate, tributylsilyl methacrylate, 2- (trimethylsiloxy) ethyl methacrylate, and methacrylamide.

  As urethane acrylate oligomers, trade names of Arakawa Chemical Industries, Ltd., Beam Set 502H, Beam Set 504H, Beam Set 505A-6, Beam Set 551B (above bifunctional), Beam Set 550B (trifunctional), Beam Set 575CB, beam set 575 (more than 6 functionalities), and the like. In addition, it is also available from Kayaku Sartomer Co., Ltd., and its trade name is CN-983, CN-985, CN-963, CN-9893, CN-9788, CN-964, CN-965, CN-966, CN9178, CN-961, CN-962, CN-980, CN-973, CN-9783, CN-977, CN-978, CN-9782 (above bifunctional), CN-970, CN-971 CN-972 (above trifunctional), CN-968, CN-975 (above trifunctional), and the like.

As urethane methacrylate oligomers, Kayaku Sartomer Co., Ltd. product names, SB-401, SB-402, SB-404, SB-500 (above 6 functionals), SB-510, SB-520 (above trifunctional) Etc.
The acrylate monomer, methacrylate monomer, urethane acrylate oligomer, and urethane methacrylate oligomer as described above can be used alone or in combination of a plurality of types.

  In addition, the silver plating treatment can be performed on any material, and further, it is desired that it can be used in any environment, but by selecting and combining the radical polymerizable compound (c) used in the present invention, Performance suitable for each material and environment can be given.

In the coating composition for silver plating of the present invention, tetraalkoxysilane or a partial condensate thereof (a), a silane compound (b) having a mercapto group, and radical polymerization having at least one carbon-carbon double bond The proportion of the compound (c) used is not particularly limited, but 3 to 100 parts by mass of a silane compound (b) having a mercapto group and radical polymerization with respect to 100 parts by mass of a tetraalkoxysilane or a partial condensate (a) thereof. The active compound (c) is preferably 15 to 470 parts by mass.
That is, when the silane compound (b) having a mercapto group is less than 3 parts by mass or more than 100 parts by mass, it becomes difficult to obtain adhesion with the silver plating film.
On the other hand, when the amount of the radical polymerizable compound (c) is less than 15 parts by mass, the flexibility of the coating film is lowered and the coating film is likely to be cracked. On the other hand, if it exceeds 470 parts by mass, it becomes difficult to obtain adhesion with the silver plating film.
As a more preferred use ratio, 5 to 50 parts by mass of the silane compound (b) having a mercapto group and 40 radically polymerizable compounds (c) with respect to 100 parts by mass of the tetraalkoxysilane or its partial condensate (a). -350 parts by mass.

  The coating composition of the present invention uses tetraalkoxysilane or a partial condensate thereof (a), a silane compound (b) having a mercapto group, and a radical polymerizable compound (c) as essential raw materials. It exhibits its performance by reacting and curing. The production method is not particularly limited, but the tetraalkoxysilane or the partial condensate thereof (a) and the silane compound (b) having a mercapto group are subjected to hydrolysis reaction respectively or together, and then a radical polymerizable compound ( The method of adding c), applying this, and reacting and curing by irradiating with ultraviolet rays is more preferable because the best coating composition can be obtained.

In this way, when a tetraalkoxysilane or its partial condensate (a) and a silane compound (b) having a mercapto group are subjected to a hydrolysis reaction, a silanol group is formed, which is gradually unstable because it is relatively unstable. Although a reaction is caused, there is no problem even if such a condensation reaction is caused in the present invention.
Furthermore, an acid catalyst is used as a catalyst in the hydrolysis reaction of tetraalkoxysilane or a partial condensate thereof (a) and a silane compound (b) having a mercapto group. As such an acid catalyst, for example, hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, acrylic acid, methacrylic acid, p-toluenesulfonic acid and the like can be used.

In the production process of the silver plating coating composition of the present invention, a solvent is used for the purpose of appropriately maintaining the viscosity and stability of the liquid. As such a solvent, a solvent having compatibility with water is preferable. For example, alcohols such as methanol, ethanol, n-propanol, i-propanol, and n-butanol, ethyl acetate, and butyl acetate are used. And esters such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethers such as tetrahydrofuran, dioxane and diethyl ether, and cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve.
A plurality of these solvents may be used in combination.
Alternatively, if the amount is small, a solvent which is not completely compatible with water such as xylene and toluene can be used in combination with the above-mentioned solvent.

The coating composition for silver plating of the present invention exhibits the target performance of the present invention by reacting the raw materials containing the above-mentioned essential three components. In addition to these three components, tetraalkoxysilane or a partial condensation thereof Silane compounds other than the product (a) and the silane compound (b) having a mercapto group may be included.
For example, such silane compounds include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, hexyltri Chlorosilanes such as methoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, and other alkoxysilanes, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, and diphenyldichlorosilane Etc. These may be used after being hydrolyzed, or can be hydrolyzed together with tetraalkoxysilane or a partial condensate thereof (a) a silane compound (b) having a mercapto group.

  Furthermore, the coating composition of the present invention is preferably reacted by adding a photopolymerization initiator to the raw material in advance during the reaction. As such a photopolymerization initiator, a commercially available one can be used, for example, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy -2-methyl-1-phenylpropan-1-one, benzophenone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-methyl-1-propan-1-one, 2-methyl-1- [ 4- (Methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, bis (2,4,6 -Trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the like.

Furthermore, the coating composition for silver plating of the present invention includes a stabilizer such as an ultraviolet absorber, an antioxidant, a polymerization inhibitor, a leveling agent, an antifoaming agent, a thickening agent, and an anti-settling agent as necessary. Further, a curing catalyst selected from a pigment, a dispersant, an antistatic agent, an antifogging agent, an inhibitor for inhibiting corrosion of silver, an acid, an alkali, a salt, and the like may be appropriately used.
The silver plating coating composition of the present invention can be applied to silver plating films prepared by various methods. For example, examples of the silver plating method include vapor deposition plating, electrolytic plating, and electroless plating.

  By the way, the curing time for obtaining the coating composition of the present invention can be very short by irradiating with strong ultraviolet rays. In order to make use of this curing speed and to make a silver-plated laminate in a short time, it is desirable that the silver plating process is also performed in a short time. Among the silver plating methods described above, electroless plating is a simple method, and is particularly preferable because silver can be instantly deposited on a substrate.

  The electroless silver plating method will be described by taking an example of the electroless silver plating method. For example, the electroless silver plating method is performed by treating a substrate on which silver plating is performed with an aqueous solution containing stannous chloride and hydrochloric acid (activation processing step). ) After thoroughly washing the substrate with water, silver is precipitated on the substrate by adding an ammonia-containing silver salt aqueous solution and a reducing agent solution so as to be mixed on the substrate. Examples of the silver salt to be used include silver nitrate, silver chloride, and silver sulfate. As the reducing agent, aqueous solutions of formaldehyde, glucose, glyoxal, hydroquinone, and the like are preferably used. In addition, amines such as tetramethylammonium hydroxide, 2-aminoethanol, 2,2'-iminodiethanol, 2,2 ', 2' '-nitrilotriethanol can be added to the ammonia-containing silver salt aqueous solution. .

In general, since a silver plating film has low wear resistance and is easily oxidized or sulfided in the air, a top coat is applied on the silver plating film as a protective film. Further, in many cases, a primer layer called an undercoat is formed and silver plating is performed on the primer layer for the purpose of eliminating adhesion between the silver plating film and the substrate or for removing scratches on the substrate.
The coating composition for silver plating of the present invention has good adhesion to the base material and silver, has excellent wear resistance, and can make the silver plating highly glossy. Both undercoat and topcoat Can be applied to.
For example, the coating composition of the present invention is formed on various substrates as an undercoat layer, silver-plated thereon, and then the coating composition of the present invention is further formed thereon as a topcoat layer. A silver-plated laminate can be obtained, and this laminate is characterized by excellent design properties and excellent silver plating protection capabilities such as wear resistance and adhesion.

When the coating composition of the present invention is applied to the undercoat, the base material on which the coating film is to be formed is not particularly limited, but various synthetic resins are preferable.
Examples of such a synthetic resin include vinyl chloride, epoxy, ABS, polycarbonate, and polypropylene.
In addition, the application of the composition of the present invention to the topcoat layer is carried out on the silver plating film. In this case, the composition of the present invention can be used regardless of the type of the substrate. .

  The silver plating coating composition of the present invention is a method such as spin coating method, dip coating method, spray coating method, flow coating method, bar code method, gravure coating method on the above-mentioned various substrates or silver plating films. It can be obtained by coating with, volatilizing the solvent used, and then curing by irradiating with ultraviolet rays.

  Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto. In the examples, “%” means “% by mass” unless otherwise specified.

[Examples 1 to 6]
90 parts by mass of silicate 40 (manufactured by Tama Chemical Co., Ltd.), 10 parts by mass of 3-mercaptopropyltrimethoxysilane and 20 parts by mass of ethanol were added, 20 parts by mass of 0.4% hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes. . 150 mass parts of ethanol was further added to this, and it hydrolyzed by making it age | cure | ripen at room temperature for 48 hours.

  1 part by weight of beam set 575CB (manufactured by Arakawa Chemical Co., Ltd.), which is a urethane acrylate oligomer containing a photopolymerization initiator, is added to 5 parts by weight of this hydrolyzate, and 1 part by weight of ethanol is added (Example) 1) Addition of 8.2 parts by mass of beam set 575CB to 5 parts by mass of hydrolyzate, and further addition of 8.2 parts by mass of ethanol (Example 2), dipentaerythritol pentaacrylate to 5 parts by mass of hydrolyzate (Acrylate monomer) KAYARAD D-310 (manufactured by Nippon Kayaku Co., Ltd.) and 1 part by weight of ethanol (Example 3), 5 parts by weight of hydrolyzate, KAYARAD D- 310 parts (manufactured by Nippon Kayaku Co., Ltd.), 0.7 parts by mass of NPGDA (manufactured by Nippon Kayaku Co., Ltd.), neopentyl glycol diacrylate, 1 part by mass of ethanol, and a photopolymerization initiator IRGACURE 184 (Ciba Special) Lithium Chemicals Co., Ltd.) (0.004 parts by mass) (Example 4), 5 parts by mass of the hydrolyzate, 0.7 parts by weight of beam set 575CB, 0.3 parts by mass of 2-phenoxyethyl acrylate and 1 ethanol 1 part by weight of KAYARAD D-310, 1 part by weight of ethanol and IRGACURE 184 (manufactured by Ciba Specialty Chemicals Co., Ltd.) with respect to 5 parts by weight of the hydrolyzate (Example 5) 0.004 parts by mass and a silver corrosion inhibitor added with 0.072 parts by mass of benzothiazole thiol (Example 6) were produced.

Each of these coating compositions of Examples 1 to 6 was applied to a 3 × 3 cm ² ABS resin substrate by a spin coating method, and was put in a dryer at 60 ° C. and dried. This was irradiated with ultraviolet rays using a high-pressure mercury lamp (integrated amount of ultraviolet rays: 3000 mJ / cm ² ) to form an undercoat layer. A silver plating film was formed by a silver mirror reaction on the substrate on which the undercoat layer was formed.
In addition, the formation method of the silver plating film by silver mirror reaction is as follows. The surface of the coat layer was activated by immersing the base material on which the undercoat layer was formed in a tin chloride aqueous solution containing 2% stannous chloride and 0.9 parts by mass of hydrochloric acid. After thoroughly washing it with water, it is immersed in a 1: 1 mixture of a 2% aqueous silver nitrate solution and a 4% aqueous ammonia solution, and a 5% glyoxal aqueous solution is added thereto to form a silver plating film on the undercoat layer. It was.

  Next, a top coat layer was formed on the silver plating film. The top coat layer used the same coating agent as the undercoat layer, and the coating method and curing conditions were the same. By such a method, a silver plating laminate having a three-layer structure of coating composition-silver film-coating composition was prepared on an ABS resin substrate.

[Example 7]
35 parts by mass of silicate 40, 1 part by mass of 3-mercaptopropyltrimethoxysilane and 7.2 parts by mass of ethanol were mixed, 7.2 parts by mass of 0.4% hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes. 50 mass parts of ethanol was further added to this, and it hydrolyzed by making it age | cure | ripen at room temperature for 48 hours.
1 part by weight of beam set 575CB was added to 5 parts by weight of this hydrolyzate, and 2 parts by weight of ethanol was further produced. Using this coating agent, a silver plating laminate was prepared in the same manner as in Examples 1-6.

[Example 8]
8 parts by mass of silicate 40, 1 part by mass of 3-mercaptopropyltrimethoxysilane, 1 part by mass of methyltrimethoxysilane and 2 parts by mass of ethanol were added, and 2.0 parts by mass of 0.4% hydrochloric acid was added. Stir. An additional 15 parts by mass of ethanol was added thereto, and hydrolysis was performed by aging at room temperature for 48 hours.
A product obtained by adding 1 part by mass of KAYARAD D-310 (manufactured by Nippon Kayaku) and 0.004 parts by mass of IRGACURE 184 to 5 parts by mass of the hydrolyzate was produced. Using this coating agent, a silver plating laminate was prepared in the same manner as in Examples 1-6.

[Example 9]
2 parts by mass of ethanol was mixed with 9 parts by mass of silicate 40, 1.8 parts by mass of 0.4% hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes. 14 mass parts of ethanol was further added to this, and it hydrolyzed by making it age | cure | ripen at room temperature for 48 hours (A).
1 part by mass of 3-mercaptopropyltrimethoxysilane and 1 part by mass of ethanol were mixed, 0.2 part by mass of 0.4% hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes. 1 mass part of ethanol was further added to this, and it hydrolyzed by making it age | cure | ripen at room temperature for 48 hours (B).
To 4.5 parts by mass of the hydrolyzate (A), 0.5 parts by mass of the hydrolyzate (B) and 1 part by mass of the beam set 575CB were added, and 1 mass part of ethanol was further added. Using this coating agent, a silver plating laminate was prepared in the same manner as in Examples 1-6.

[Example 10]
9 parts by mass of silicate 40, 1 part by mass of mercaptoethyltrimethoxysilane, and 2 parts by mass of ethanol were mixed, 2.0 parts by mass of 0.4% hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes. An additional 15 parts by mass of ethanol was added thereto, and hydrolysis was performed by aging at room temperature for 48 hours.
A product obtained by adding 1 part by mass of beam set 575CB and 1 part by mass of ethanol to 5 parts by mass of the hydrolyzate was produced. Using this coating agent, a silver plating laminate was prepared in the same manner as in Examples 1-6.

[Comparative Examples 1-2]
1 part by weight of beam set 575CB with 1 part by weight of ethanol (Comparative Example 1), 1 part by weight of KAYARAD D-310 with 0.03 parts by weight of IRGACURE184 and 1 part by weight of ethanol (Comparative Example 2) ) Was used to prepare silver-plated laminates in the same manner as in Examples 1 to 6, respectively.

[Comparative Example 3]
2 parts by mass of ethanol was mixed with 10 parts by mass of silicate 40, 1.8 parts by mass of 0.4% hydrochloric acid was added, and the mixture was stirred at room temperature for 30 minutes. An additional 15 parts by mass of ethanol was added thereto, and hydrolysis was performed by aging at room temperature for 48 hours. 1.1 parts by mass of beam set 575CB and 1.1 parts by mass of ethanol were added to 5 parts by mass of this hydrolyzate, and a silver-plated laminate was prepared in the same manner as in Examples 1-6.

[Comparative Example 4]
Hydrolysis was performed by adding 0.3 parts by mass of 0.4% hydrochloric acid to 2 parts by mass of 3-mercaptopropyltrimethoxysilane, stirring at room temperature for 30 minutes, and then aging at room temperature for 48 hours. A silver-plated laminate was prepared in the same manner as in Examples 1 to 6, using 1 part by mass of this hydrolyzate and 5 parts by mass of beam set 575CB and 5 parts by mass of ethanol.

[Comparative Example 5]
10 parts by mass of silica sol IPA-ST (SiO ₂ solid content 30%, manufactured by Nissan Chemical Industries, Ltd.) is mixed with 1 part by mass of 3-mercaptopropyltrimethoxysilane, and 0.3 parts by mass of 0.4% hydrochloric acid is added to room temperature. And stirred for 30 minutes. 13 mass parts of ethanol was further added to this, and it hydrolyzed by making it age | cure | ripen at room temperature for 48 hours. A silver-plated laminate was prepared in the same manner as in Examples 1 to 6, using 5.5 parts by mass of the hydrolyzate and 1 part by mass of Beam Set 575CB and 1 part by mass of ethanol.

  Using the silver-plated laminates obtained in these Examples and Comparative Examples, the performance evaluation (coating adhesion, coating hardness, silver plating appearance, coating film appearance) test of the coating composition was performed. In addition, each performance evaluation was performed with the following method. The evaluation results are shown in Table 1.

<Coating adhesion>
On the surface of the test laminate, razors were used to make 11 cuts at 1 mm intervals in both vertical and horizontal directions to form 100 grids. A cellophane tape was closely adhered to this surface. Next, the cellophane tape was abruptly peeled perpendicularly to the plated surface, and the number of cells remaining without peeling of the coating was calculated. From the calculation results, the remaining number (X) was expressed as X / 100.

<Coating hardness>
The pencil lead with the cylindrical core left behind was left as it was, and the pencil lead from which only the wood part was shaved was pressed against the silver-plated surface at a load of 750 g in a direction of 45 degrees. With the load applied, the pencil lead was pressed and moved. The film hardness was determined by the core hardness based on whether or not the film was damaged.

<Silver plating appearance>
The gloss, unevenness, color, etc. of the silver plating film after the formation of the silver plating layer were visually observed, and evaluated with ○ (good), Δ (slightly bad), and x (bad).

<Appearance of coating film>
The appearance of the coating film after forming the undercoat layer with the coating composition was visually observed, and evaluated with ○ (good), Δ (slightly bad), and × (poor).

Claims (6)

After reacting a tetraalkoxysilane represented by the following general formula (Chemical Formula 1) or a partial condensate thereof (a) with a silane compound (b) having a mercapto group, it is reacted with at least one carbon-carbon dioxygen. Silver plating characterized by adding a radically polymerizable compound (c) having a heavy bond , or by hydrolyzing (a) and (b), or together, and then adding (c) thereto Method for manufacturing coating composition.

Tetraalkoxysilane or a partial condensate thereof per 100 parts by weight of (a), a silane compound having a mercapto group (b) is 3 to 100 parts by mass, at least one carbon - radical having a carbon-carbon double bond The method for producing a coating composition for silver plating according to claim 1 , wherein the polymerizable compound (c) is in the range of 15 to 470 parts by mass. The method for producing a coating composition for silver plating according to claim 1 or 2, wherein the silane compound (b) having a mercapto group is a compound represented by the following general formula (Formula 2).

4. The method for producing a coating composition for silver plating according to claim 1, wherein the silane compound (b) having a mercapto group is 3-mercaptopropyltrimethoxysilane or 3-mercaptopropyltriethoxysilane. The radically polymerizable compound (c) having at least one carbon-carbon double bond is a compound selected from an acrylate monomer, a methacrylate monomer, a urethane acrylate oligomer, and a urethane methacrylate oligomer. The manufacturing method of the coating composition for silver plating of 1 item | term. The coating composition for silver plating obtained by the manufacturing method of any one of Claims 1-5.