JP2012188710A - Second activation liquid for silver mirror and method for forming silver thin film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a method for forming a silver thin film, capable of forming a silver thin film layer having excellent adhesion without significant deterioration in adhesion between an undercoat layer and a silver thin film when a curable top coat is applied on the silver thin film; and a second activation liquid for a silver mirror, used in the method.SOLUTION: A method for forming a silver thin film; and a second activation liquid for a silver mirror, used for the method and containing heavy metal sulfide are provided. The method for forming a silver thin film includes the steps of: processing an undercoat layer provided on a surface of a base material with a first activation liquid for a silver mirror, the liquid containing stannous chloride; further processing the undercoat layer with the second activation liquid for a silver mirror, the liquid containing heavy metal sulfide; forming a silver thin film layer by a silver mirror reaction on the undercoat layer processed with the heavy metal sulfide; and forming a top coat on the silver thin film layer.

Description

  The present invention relates to a second active treatment liquid for silver mirror and a method for forming a silver thin film using the same, and in particular, a second active treatment liquid for silver mirror capable of forming a silver thin film layer having excellent adhesion, and excellent adhesion. The present invention relates to a method for forming a silver thin film capable of forming a silver thin film layer having properties.

  Since a coated body having a silver thin film layer has an excellent metallic luster, it is processed into a metal or plastic surface and used as a designable material or a reflective material. Moreover, it utilizes, for example as an electromagnetic wave shielding material, using the electroconductivity which a silver thin film layer has. In many cases, the silver thin film layer is provided with a hard coat material as a top coat layer on the surface because the surface is easily damaged and is easily deteriorated in the air.

  It has been conventionally known that a thermosetting resin is used as a top coat layer for protecting a silver thin film layer obtained by a silver mirror reaction. For example, JP 2000-129448 discloses a liquid epoxy resin, an unsaturated polyester resin, The use of a fluororesin, an acrylic resin, a melamine resin, a silicon resin, or the like is disclosed. Japanese Unexamined Patent Application Publication No. 2003-155580 discloses the use of a silicon acrylic resin, and Japanese Unexamined Patent Application Publication No. 2002-256445. The use of a two-component curable polyurethane resin or an acrylic-modified silicone resin is disclosed. It is also known to use an ultraviolet curable resin as a top coat layer for protecting the silver thin film layer. For example, JP 2008-110101 A and JP 2008-176050 A disclose a top protecting the silver thin film layer. It is described that an ultraviolet curable resin or an electron beam curable resin may be used as the coating layer.

  However, when such a curable topcoat layer is used on the silver thin film layer, the adhesion between the undercoat layer and the silver thin film layer is remarkably reduced when the topcoat layer is cured. There is a problem that the adhesiveness is reduced due to changes, the influence of salt water, and the like. In particular, this reduction in adhesiveness appears more prominently when the topcoat layer is an ultraviolet curable resin, and improvement has been demanded.

  As a method for improving the adhesion between the undercoat layer and the silver thin film layer obtained by the silver mirror reaction, for example, JP-A-2000-104175 (Patent Document 1) discloses that the undercoat layer includes palladium ions and tin (II). ) Catalyzer accelerator method in which an aqueous solution containing ions is brought into contact with an activated treatment solution containing sulfuric acid, and a sensitizer activator in which a hydrochloric acid-acid stannous chloride aqueous solution and a hydrochloric acid-acid palladium chloride aqueous solution are simultaneously contacted A beta method is disclosed. Japanese Patent Laid-Open No. 2004-190061 (Patent Document 2) discloses a method of performing an activation treatment with stannous ions and palladium ions on an undercoat layer, and Japanese Patent Laid-Open No. 11-335858 (Patent Document 3). Dissolve stannous chloride anhydride in appropriate concentration of hydrochloric acid to prepare a stannous chloride hydrochloric acid solution, and then dissolve anhydrous palladium chloride in appropriate concentration of hydrochloric acid to prepare a palladium chloride hydrochloric acid solution. A method of mixing and spraying a solution is disclosed. Furthermore, in JP-A-6-38860 (Patent Document 4), an activation treatment is carried out by immersing in a tin (II) chloride aqueous solution for 1 minute as a direct activation treatment in a polycarbonate resin, and then immersing in a palladium chloride aqueous solution for 1 minute. Furthermore, a method using a surfactant is disclosed.

  However, even when a method for improving the adhesion between the undercoat layer and the silver thin film layer obtained by the silver mirror reaction is used, when the top coat layer is provided, a silver thin film layer having excellent adhesion is obtained. It was not possible to improve it.

JP 2000-104175 A JP 2004-190061 A JP-A-11-335858 JP-A-6-38860

  The present invention provides a second active treatment solution for a silver mirror capable of forming a silver thin film layer having excellent adhesiveness, and a silver thin film forming method capable of forming a silver thin film layer having excellent adhesiveness. Objective.

As a result of various studies to solve the above problems, it has been found that the above problems can be solved by the following invention.
1) A second active treatment solution for silver mirrors containing heavy metal sulfides.
2) A step of treating the undercoat layer provided on the surface of the substrate with a first active treatment solution for silver mirror containing stannous chloride, and treating the undercoat layer treated with the stannous chloride with a heavy metal sulfide. A step of treating with a second active treatment solution for silver mirrors, a step of forming a silver thin film layer by a silver mirror reaction on the undercoat layer treated with the heavy metal sulfide, and a top coat layer on the silver thin film layer A method for forming a silver thin film comprising at least a step of providing

  According to the present invention, it is possible to provide a second active treatment liquid for a silver mirror capable of forming a silver thin film layer having excellent adhesiveness. Moreover, the silver thin film formation method which can form the silver thin film layer which has the outstanding adhesiveness can be provided.

  The method for forming a silver thin film of the present invention comprises a step of treating an undercoat layer provided on the surface of a substrate with a first active treatment liquid for silver mirror containing stannous chloride, and an undercoat treated with the stannous chloride. Treating the coat layer with a second active treatment solution for silver mirrors containing heavy metal sulfide, forming a silver thin film layer on the undercoat layer treated with the heavy metal sulfide by a silver mirror reaction, and the silver A step of providing a topcoat layer on the thin film layer.

This will be described in more detail.
As the base material used in the present invention, various plastics, metals, glasses, rubbers and the like are used. Examples of the plastics include polycarbonate resin, acrylic resin, ABS resin, vinyl chloride resin, epoxy resin, phenol resin, polyethylene terephthalate (PET) resin, polyester resin such as polybutylene terephthalate (PBT) resin, fluorine resin, polypropylene ( PP) resin, a resin obtained by compounding these, and fiber reinforced plastic (FRP) reinforced with organic fibers such as nylon fiber and pulp fiber may be mentioned, but not particularly limited. Examples of the metal include, but are not limited to, iron, aluminum, stainless steel, copper, and brass. The glass is not particularly limited, such as inorganic glass or plastic glass.

  In order to improve the adhesion between these base materials and the undercoat layer, the base materials may be pretreated. Examples of the pretreatment method include a pretreatment by a wet method such as a cleaning treatment with detergent, solvent washing or ultrasonic washing, or a pretreatment by a dry method such as a corona treatment, an ultraviolet ray irradiation or an electron beam irradiation treatment. Moreover, you may provide the coating material (anchor agent) which has adhesiveness in both a base material and an undercoat layer.

  The undercoat layer is required to have good adhesion to the substrate and excellent adhesion to the silver thin film provided on the undercoat layer. It is also required to form a smooth surface. Examples of undercoat materials include alkyd polyols, polyester polyols, acrylic polyols and the like, polyol-based paints in which isocyanate compounds are mixed as curing agents with polymers or oligomers having terminal hydroxyl groups, and epoxy resins in which amine compounds are mixed as curing agents. A system paint or the like is selected based on the properties required for the substrate and the coated body. The thickness of the undercoat layer is preferably 5 to 30 μm, but is not particularly limited.

  Depending on the type of base material, for example, a primer layer may be provided between the base material and the undercoat layer for polypropylene, iron, and aluminum for rust prevention and adhesion. Further, when high temperature drying at 100 ° C. or higher cannot be performed due to deformation and shrinkage of the base material, a hardening accelerator may be added or a leveling agent may be used to improve the surface quality. Curing accelerators include urethane curing accelerator from Nagashima Co., Ltd., drying accelerator A from Sansei Paint Industry Co., Ltd., Nitto Bussan Co., Ltd., San Apro Co., Ltd., Nippon Chemical Industry Co., Ltd., Mitsubishi Chemical Co., Ltd., etc. Curing of 1.8-diazabicyclo [5,4,0] undecene-7 and 1,5-diazabicyclo [4,3,0] nonene-5 phenols, oleates, octylates and epoxy resins as accelerators Various amines are available as accelerators. As leveling agents, silicon leveling agents and fluorine leveling agents can be obtained from Tohshin Chemical Co., Ltd., DIC Corporation, and BYK Co., Ltd. If more leveling agents are used, adhesion between the undercoat layer and the silver mirror plating layer is possible. It is necessary to be careful because it causes a decrease in the temperature. The amount of the curing accelerator used is 0.1 to 2% by weight, preferably 0.3 to 1% by weight, based on the whole undercoat paint, and the amount of the leveling agent used is 0.001 to 1% by weight based on the whole undercoat paint. Preferably, it is 0.005-0.05 mass%.

  In the silver thin film forming method of the present invention, in order to deposit silver on the surface of the undercoat layer, the undercoat layer provided on the surface of the base material is a first active treatment liquid for silver mirrors containing stannous chloride. To process. Thus, stannous ions are supported on the surface of the undercoat layer. As the method, there are a method of immersing a substrate provided with an undercoat layer in a first active treatment liquid for silver mirror, a method of applying a first active treatment liquid for silver mirror on the surface of the undercoat layer, and the like. Although it can select arbitrarily by the shape of a base material etc., as an application | coating method, the spray application which does not choose the shape of a base material especially is suitable. Furthermore, you may wash | clean the activation process liquid adhering excessively to the undercoat layer surface with deionized water or purified distilled water.

  Examples of the first active treatment solution for silver mirrors containing stannous chloride include activation treatment solutions described in JP-A-2007-197743 and JP-A-2006-274400.

  A step of performing silver ion treatment may be provided between the step of treating with the first active treatment liquid for silver mirror and the step of treating with the second active treatment liquid for silver mirror described later. For the treatment with silver ions, for example, treatment with a treatment solution containing silver nitrate is simple and preferable. The silver nitrate concentration of the aqueous silver nitrate solution used in this step is preferably 0.1 mol / kg or less and then brought into contact with the undercoat layer treated with stannous chloride. However, when this silver ion treatment is performed, excessive silver may reduce the effect of the second active treatment liquid for silver mirror, and therefore, it is preferable to wash with deionized water after the silver ion treatment. For these activation processes, spray coating in which a new solution is always supplied is suitable.

  In the method for forming a silver thin film of the present invention, the undercoat layer treated with the stannous chloride is treated with a second active treatment solution for a silver mirror containing a heavy metal sulfide. A silver thin film layer having excellent adhesiveness can be obtained by forming a silver thin film layer by a silver mirror reaction after the treatment with the second active treatment liquid for silver mirror, even when a topcoat layer is provided.

  As the heavy metal sulfide contained in the second active treatment liquid for silver mirror of the present invention, sulfides such as silver, antimony, bismuth, cadmium, cobalt, lead, nickel, palladium, rhodium, gold, platinum, polysulfides, Or a mixture, a mixed crystal, etc. are mentioned. Among them, palladium sulfide and a mixed crystal of palladium sulfide and silver are preferable because excellent adhesiveness is obtained, and a mixed crystal of palladium sulfide and silver is particularly preferable.

  The heavy metal sulfide can be obtained by mixing a heavy metal water-soluble salt and a sulfide. When mixing these, it is preferable to use a water-soluble polymer as a protective colloid. Examples of such water-soluble polymers include gelatin, starch, dialdehyde starch, carboxymethyl cellulose, gum arabic, sodium alginate, hydroxyethyl cellulose, polystyrene sulfonic acid, a copolymer of vinyl imidazole and acrylamide, polyvinyl alcohol, and Japanese Patent Application Laid-Open No. 8-21614. Can be mentioned, and stable metal colloidal fine particles can be made among these water-soluble polymers.

  A preferable result can be obtained by setting the preferred particle diameter of the heavy metal sulfide contained in the second active treatment liquid for silver mirror to 10 to 500 angstroms. More preferably, it is 50-200 angstrom. In order to obtain a heavy metal sulfide having such a particle size, it is possible to appropriately adjust the concentration of the water-soluble polymer, the mixing temperature, and the mixing time. The concentration of the water-soluble polymer during mixing is 0.01 to The mixing temperature is preferably 0.2% by mass, the mixing temperature is preferably 30 to 50 ° C., and the mixing time is preferably in the range of 3 to 30 minutes.

  The content of the heavy metal sulfide contained in the second active treatment liquid for silver mirror is preferably 0.001 to 0.3 mmol / kg, more preferably 0.01 to 0.05 mmol / kg. is there. If it exceeds 0.3 mmol / kg, the reflectivity of the silver mirror plating may decrease due to the concentration of the contained salt, and it may become yellowish. If it is less than 0.001 mmol / kg, the adhesiveness gradually increases. The improvement effect may be reduced.

  As a preferred treatment method of the second active treatment liquid for silver mirror used in the present invention, as in the treatment method of the first active treatment liquid for silver mirror described above, a method of immersing in the second active treatment liquid for silver mirror, There is a method of applying a second active treatment liquid for silver mirror to the surface treated with one active treatment liquid. Although it can select arbitrarily by the shape of a base material etc., as an application | coating method, the spray application which does not choose the shape of a base material especially is suitable.

  In the present invention, a silver thin film layer is formed by a silver mirror reaction on the undercoat layer treated with the second active treatment liquid for silver mirror containing the heavy metal sulfide. The silver thin film layer by silver mirror reaction is applied so that two solutions of an ammoniacal silver nitrate solution containing silver nitrate and ammonia and a reducing agent solution containing a reducing agent and a strong alkali component are mixed on the surface subjected to the above treatment. When the oxidation-reduction reaction occurs, metallic silver is deposited, and a silver coating is formed to form a silver thin film layer.

  As the reducing agent solution, an aldehyde compound such as glucose or glyoxal, an organic compound such as a hydrazine compound such as hydrazine sulfate, hydrazine carbonate or hydrazine hydrate, or an aqueous solution such as sodium sulfite or sodium thiosulfate is preferably used.

  Several additives may be added to the aqueous silver solution in order to produce good silver. For example, monoethanolamine, tris (hydroxymethyl) aminomethane, 2-amino-2-hydroxymethyl-1,3-propanediol, 1-amino-2-propanol, 2-amino-1-propanol, diethanolamine, diisopropanol Examples include amino alcohol compounds such as amine, triethanolamine and triisopropanolamine, amino acids such as glycine, alanine and sodium glycine, and salts thereof, but are not particularly limited.

  As a method of applying the two solutions of the ammoniacal silver nitrate solution and the reducing agent solution so as to be mixed on the surface of the undercoat layer, two kinds of aqueous solutions are mixed in advance, and this mixed solution is used with a spray gun or the like. A method of spraying on the surface of the coating layer, a method of spraying using a concentric spray gun having a structure in which two types of aqueous solutions are mixed and immediately discharged in the head of the spray gun, and a two-head spray having two spray nozzles for the two types of aqueous solutions There are a method of spraying and spraying each from a gun, a method of spraying two kinds of aqueous solutions simultaneously using two separate spray guns, and the like. These can be arbitrarily selected according to the situation.

  Subsequently, it is preferable to wash the surface of the silver thin film layer with deionized water or purified distilled water, and remove the solution after the silver mirror reaction remaining on the surface. In addition, before the top coat layer is provided on the silver thin film layer, for the purpose of stabilizing the deposited metal silver, a treatment such as immersion in a solution containing an organic compound that reacts with or has affinity with silver or coating the solution is performed. It can be carried out.

  As the organic compound, a nitrogen-containing heterocyclic compound having a mercapto group or a thione group is effectively used. Speaking of the heterocyclic ring of the nitrogen-containing heterocyclic compound, there are imidazole, imidazoline, thiazole, thiazoline, oxazole, oxazoline, pyrazoline, triazole, thiadiazole, oxadiazole, tetrazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine, etc. Imidazole, triazole and tetrazole are preferred. Specific examples include 2-mercapto-4-phenylimidazole, 2-mercapto-1-benzylimidazole, 2-mercapto-benzimidazole, 1-ethyl-2-mercapto-benzimidazole, 2-mercapto-1-butyl-benzimidazole. 1,3-diethyl-benzimidazoline-2-thione, 1,3-dibenzyl-imidazolidine-2-thione, 2,2'-dimercapto-1,1'-decamethylene-diimidazoline, 2-mercapto-4- Phenylthiazole, 2-mercapto-benzothiazole, 2-mercapto-naphthothiazole, 3-ethyl-benzothiazoline-2-thione, 3-dodecyl-benzothiazoline-2-thione, 2-mercapto-4,5-diphenyloxazole, 2-mercaptobenzoxazole 3-pentyl-benzoxazoline-2-thione, 1-phenyl-3-methylpyrazolin-5-thione, 3-mercapto-4-allyl-5-pentadecyl-1,2,4-triazole, 3-mercapto-5-nonyl -1,2,4-triazole, 3-mercapto-4-acetamido-5-heptyl-1,2,4-triazole, 3-mercapto-4-amino-5-heptadecyl-1,2,4-triazole, 2 -Mercapto-5-phenyl-1,3,4-thiadiazole, 2-mercapto-5-n-heptyl-oxathiazole, 2-mercapto-5-n-heptyl-oxadiazole, 2-mercapto-5-phenyl- 1,3,4-oxadiazole, 2-heptadecyl-5-phenyl-1,3,4-oxadiazole, 5-mercapto- -Phenyl-tetrazole, 2-mercapto-5-nitropyridine, 1-methyl-quinoline-2 (1H) -thione, 3-mercapto-4-methyl-6-phenyl-pyridazine, 2-mercapto-5,6-diphenyl -Pyrazine, 2-mercapto-4,6-diphenyl-1,3,5-triazine, 2-amino-4-mercapto-6-benzyl-1,3,5-triazine, 1,5-dimercapto-3,7 -Diphenyl-s-triazolino [1,2-a] -s-triazoline and the like.

  Since the metallic silver thus formed is easily damaged, a top coat layer is further provided on the surface of the silver thin film layer. The topcoat resin composition constituting the topcoat layer is generally a thermosetting resin, but an ultraviolet curable resin can also be used. The use of an ultraviolet curable resin is particularly suitable because the manufacturing process time is short. In the ultraviolet curable resin, a photopolymerization initiator is used as necessary. These topcoat layers may be used in combination with coloring materials and additives as necessary.

  Examples of the thermosetting resin constituting the top coat layer include liquid epoxy resins, unsaturated polyester resins, fluororesins, acrylic resins, melamine resins, and silicon resins described in Japanese Patent Application Laid-Open No. 2000-129448. Examples thereof include silicon acrylic resins described in JP-A-155580, two-component curable polyurethane resins described in JP-A-2002-256445, and acrylic-modified silicone resins.

  As the ultraviolet curable resin, monomers and oligomer compounds mainly containing an ethylenically unsaturated group are preferably used, which include an electron curable resin and is cured with ultraviolet rays. Specific examples include amide monomers, (meth) acrylate monomers, urethane acrylates, polyester (meth) acrylates and epoxy (meth) acrylates, and acrylic silicon oligomers. Examples of the amide monomer include amide compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, and acryloylmorpholine. Examples of (meth) acrylate monomers include: hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxy-3-phenylpropyl acrylate; phenoxyethyl (meta ) Acrylates of alkylene oxide adducts of phenols such as acrylates and their halogen nucleus substitution products; mono- or di (meth) acrylates of ethylene glycol, mono (meth) acrylates of methoxyethylene glycol, mono- or di (meta) of tetraethylene glycol ) Acrylates, mono- or di (meth) acrylates of glycols, such as mono- or di (meth) acrylates of tripropylene glycol; trimethylolpropane tri (meth) acrylates, Poly (pentaerythritol) tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexaacrylate, etc., and (meth) acrylic acid ester of alkylene oxide, isocyanuric acid EO modified di- or tri (meth) acrylate, etc. Is mentioned.

  Examples of the urethane (meth) acrylate oligomer include a reaction product obtained by further reacting a hydroxyl group-containing (meth) acrylate with a polyol and an organic polyisocyanate reaction product. Here, examples of the polyol include a low molecular weight polyol, polyethylene glycol, and polyester polyol, and examples of the low molecular weight polyol include ethylene glycol, propylene glycol, cyclohexanedimethanol, and 3-methyl-1,5-pentanediol. Examples of the polyether polyol include polyethylene glycol and polypropylene glycol. Examples of the polyester polyol include these low molecular weight polyols and / or polyether polyols, adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid and terephthalic acid. And a reaction product with an acid component such as a dibasic acid or an anhydride thereof. Examples of the organic polyisocyanate include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of the hydroxyl group-containing (meth) acrylate include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

  As a polyester (meth) acrylate oligomer, the dehydration condensate of a polyester polyol and (meth) acrylic acid is mentioned. Examples of the polyester polyol include low molecular weight polyols such as ethylene glycol, polyethylene glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, propylene glycol, polypropylene glycol, 1,6-hexanediol and trimethylolpropane, and these And a reaction product from a polyol such as an alkylene oxide adduct and an acid component such as a dipic acid such as adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid and terephthalic acid, or an anhydride thereof. Epoxy acrylate is obtained by addition reaction of unsaturated carboxylic acid such as (meth) acrylic acid to epoxy resin. Epoxy (meth) acrylate of bisphenol A type epoxy resin, epoxy (meth) of phenol or cresol novolac type epoxy resin Examples thereof include (meth) acrylic acid addition reactants of acrylate and polyether diglycidyl ether.

  The acrylic silicon-based oligomer is composed of an acrylic oligomer as a main agent and a silane coupling agent as a curing agent.

  Photopolymerization initiators include benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenyl Acetophenones such as acetophenone, 1,1-dichloroacetophenone, 1-hydroxyacetophenone, 1-hydroxycyclohexyl phenyl ketone and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one; 2 -Anthraquinones such as methyl anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone; 2,4-dimethylthioxa Thioxanthone such as benzene, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylpyroxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; 2,4,6-trimethylbenzoyl diphenylphosphine oxide and the like Monoacylphosphine oxide or bisacylphosphine oxide; benzophenones such as benzophenone; and xanthones. These photopolymerization initiators can be used alone or in combination with a benzoic acid-based or amine-based photopolymerization initiation accelerator.

  The content of the photopolymerization initiator is preferably 0.01 to 20% by mass, particularly preferably 0.5 to 7% by mass with respect to 100% by mass of the ultraviolet curable resin.

  In order to cure the top coat composition, it is sufficient to irradiate with an electron beam, ultraviolet rays or the like, and it is preferable to cure by irradiation with ultraviolet rays from the viewpoint of cost. The light source used for ultraviolet irradiation preferably has a light emission distribution at a wavelength of 420 nm or less. For example, a lamp light source such as a xenon lamp, a halogen lamp, a tungsten lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a medium pressure mercury lamp, or a low pressure mercury lamp. And laser light sources such as argon ion laser, YAG laser, excimer laser, and nitrogen laser. The amount of ultraviolet irradiation is appropriately selected as necessary.

  The thickness of the thermosetting resin top coat layer is preferably in the range of 10 to 25 μm, and the ultraviolet curable resin top coat is preferably in the range of 3 to 10 μm. If the layer is too thin, the function of protecting the silver thin film layer cannot be obtained, and a uniform coating film cannot be formed. On the other hand, if it is too thick, the peripheral portion is locally thickened further. Furthermore, since the light transmission distance becomes longer and the light loss increases, the reflectance of the silver mirror plating layer is lowered, which is not preferable.

  The colorant added to the topcoat layer can be color-tuned by further containing a colorant such as a pigment or dye. It is more preferable that the absorption wavelength of the color material does not include the absorption wavelength of the photoinitiator because it does not hinder the activity of the photoinitiator. Examples of pigments include organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyanine green, and hansa yellow; inorganics such as titanium oxide, aluminum oxide, calcium carbonate, barium sulfate, mica, petal, and composite metal oxides. Examples thereof include, but are not limited to, pigments. One or a combination of two or more selected from these pigments can be used. The dispersion of the pigment is not particularly limited, for example, a method of directly dispersing the pigment powder by a usual method, for example, dyno mill, paint shaker, sand mill, ball mill, kneader, roll, dissolver, homogenizer, ultrasonic vibration, stirrer, etc. Is used. At that time, it is possible to use a dispersant, a dispersion aid, a thickener, a coupling agent and the like. The amount of pigment added is not particularly limited because the concealability varies depending on the type of pigment, but is preferably 0.01 to 5% by mass, more preferably 0.05%, based on the total solid content of the topcoat layer, for example. It is -2 mass%. When the added amount of the pigment is less than 0.01% by mass, there is almost no coloring property, and when it exceeds 5% by mass, the brightness of the silver mirror plating layer may be lowered.

  Examples of dyes include azo, anthraquinone, indoidoid, sulfide, triphenylmethane, xanthene, alizarin, acridine, quinoneimine, thiazole, methine, nitro, and nitroso dyes. Although it is mentioned, it is not limited to these. One or a combination of two or more selected from these dyes can be used. The addition amount of the dye is not particularly limited because the concealability varies depending on the type of the dye, but is preferably 0.005 to 4% by mass, more preferably 0.01 to 4% by mass with respect to the total solid content of the topcoat layer. 2% by mass. When the addition amount of the dye is less than 0.005% by mass, there is almost no coloring property, and when it exceeds 4% by mass, the brightness of the silver mirror plating layer may be lowered.

  The topcoat layer may further contain a leveling agent, metal powder, glass powder, antibacterial agent, antioxidant, ultraviolet absorber, and the like as additives.

  As a method for providing the top coat layer, it is common to apply each coating composition by dissolving it in an organic solvent. The coating method may be a conventionally known coating method, such as gravure roll method, reverse roll method, dip roll method, bar coater method, knife coater method, air spray method, airless spray method, dip method, etc. Can also be used. The undercoat layer described above can also be applied by these application methods.

  Examples of the organic solvent for the top coat layer and the undercoat layer include hydrocarbons such as cyclohexane and Solvesso 100 (trade name, manufactured by Exxon Chemical), cellosolve, methyl cellosolve, butyl cellosolve, carbitol, diethylcarbitol, and the like. Ethers, methanol, ethanol, isopropyl alcohol, butyl alcohol, cyclohexanol and other alcohols, ethyl acetate, n-butyl acetate, isobutyl acetate, amyl formate, isoamyl acetate, isobutyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate Butyl butyrate, alkyl esters, methyl lactate, ethyl lactate, methyl oxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, ethoxyacetic acid Esters such as chill, ethyl ethoxyacetate, diethylene glycol dimethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl Examples include ethers such as ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone. It is not intended to be limiting. These organic solvents are selected depending on the solubility of the undercoat composition and the topcoat composition, but are selected from the viewpoint of improving the coating surface condition, etc., and can be used alone, but are used in combination of two or more. There are many cases.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the content of this invention is not restricted to an Example. % Is based on mass.

Example 1
The surface of the polycarbonate plate was degreased, washed with water and dried. A commercially available undercoat paint (under clear No. 0128 manufactured by Ohashi Chemical Industries) was added to the thinner together with a curing agent (under clear curing agent-N manufactured by Ohashi Chemical Industry) in a ratio of 10: 2: 10 (mass ratio). The paint obtained by mixing in the above was spray applied using a spray gun. An undercoat layer having a thickness of 20 μm was formed by heating and drying at 80 ° C. for 1 hour.

  First activation solution for silver mirror containing 0.15 mol hydrochloric acid and 0.06 mol stannous chloride is made up to 1 kg with water, sprayed onto the layer with a spray gun, and then activated with deionized water. Washed with

  Subsequently, 0.03 mmol of sodium thiosulfate pentahydrate dissolved in 1% with deionized water was added to 10 g of a 0.1% solution of the water-soluble polymer P-2 exemplified in JP-A-8-21614. To a solution kept at 40 ° C., 0.03 mmol of palladium chloride dissolved in 0.5% in a phosphoric acid solution was added, fine particle growth was performed at 40 ° C. for 10 minutes, and a second silver mirror mirror containing 0.03 mmol of palladium sulfide was added. A concentrated solution (stock solution) of the active treatment solution was obtained. The concentrated solution was made up to 1 kg with deionized water, and the substrate surface treated with the first activation treatment solution for silver mirror was sprayed with a spray gun for activation treatment.

  The silver mirror plating solution was prepared as follows. Separately from a silver nitrate solution obtained by dissolving 20 g of silver nitrate in 1000 g of deionized water, 100 g of 28% aqueous ammonia solution and 5 g of monoethanolamine were dissolved in 1000 g of deionized water to prepare an ammonia solution. Prior to use, the silver nitrate solution and the ammonia solution were mixed one-to-one to obtain an ammoniacal silver nitrate solution. Next, 10 g of hydrazine sulfate, 5 g of monoethanolamine and 10 g of sodium hydroxide were dissolved in 1000 g of deionized water to prepare a reducing agent solution.

  The ammoniacal silver nitrate solution and the reducing agent solution thus obtained were sprayed simultaneously on the surface of the substrate treated with the second active treatment liquid for silver mirror using a double-head spray gun to form a silver thin film, After washing with deionized water, it was dried in a dryer at 70 ° C. for 30 minutes.

Next, a top coat layer was provided on the silver mirror plating layer. 100 g of acrylic silicon oligomer and 3 g of photopolymerization initiator (Irgacure 184) are sufficiently dissolved in 280 g of thinner (mixing methylethylketone and butylcellsolve in a ratio of 1: 1) to form a top coat paint and sprayed onto the silver thin film layer Sprayed with a gun. The top coat was cured by irradiating with an ultraviolet ray having an irradiation energy of about 800 mJ / cm ^{2 with} an ultraviolet ray irradiation apparatus (made by Eye Graphics Co., Ltd., model ECS-151U) using a xenon lamp after being heated and dried at 80 ° C. for 15 minutes. A top coat layer was formed. Thus, the silver mirror plating coating body was obtained on the polycarbonate plate surface.

(Example 2)
As a second active treatment solution for silver mirror of Example 1, a thiol dissolved in 1% with deionized water in 10 g of a 0.1% solution of a water-soluble polymer P-2 exemplified in JP-A-8-21614 To a solution that was added 0.03 mmol of sodium sulfate pentahydrate and kept at 40 ° C., 0.03 mmol of palladium chloride dissolved in 0.5% in a phosphoric acid solution was added, and silver nitrate dissolved in 1% with deionized water. Fine particles were grown at 40 ° C. for 10 minutes by adding 0.03 mmol to obtain a concentrated solution (stock solution) of a second active treatment solution for silver mirror containing 0.03 mmol of a mixed crystal solution of palladium sulfide and silver. This concentrated solution is made up to 1 kg in total with deionized water to produce a second active treatment solution for silver mirror, and the substrate surface treated with the first activation treatment solution for silver mirror produced in Example 1 is sprayed with a spray gun to activate. The treatment was performed. Later, silver mirror plating and top coating were performed in the same manner as in Example 1 to obtain a silver mirror plating coated body on the polycarbonate plate surface.

(Example 3)
Between the step of treating with the first active treatment solution for silver mirror of Example 2 and the step of treating with the second activation treatment solution for silver mirror, a 1% silver nitrate solution dissolved in deionized water is sprayed with a spray gun, and thereafter A silver mirror plating coated body was obtained on the surface of the polycarbonate plate in the same manner as in Example 2 except that washing with deionized water was added.

(Comparative Example 1)
A solution obtained by dissolving 0.03 mmol of palladium chloride in phosphoric acid was added to 0.06 mol of stannous chloride solution dissolved in 0.15 mol of hydrochloric acid as the first active treatment solution for silver mirror in Example 1, and deionized water was added. A first active treatment solution for silver mirror was prepared with a total of 1 kg. The polycarbonate was treated in the same manner as in Example 1 except that the first active treatment for silver mirror containing stannous chloride and palladium chloride was performed, and the silver mirror plating was performed without performing the second active treatment for silver mirror containing palladium sulfide. A silver mirror plating coating was obtained on the plate surface.

(Comparative Example 2)
0.03 mmol of palladium sulfide of Example 1 was added to 0.06 mol of stannous chloride solution dissolved in 0.15 mol of hydrochloric acid as the first active treatment solution for silver mirror of Example 1, and the total was added with deionized water. First active treatment liquid for silver mirror was prepared as 1 kg. The polycarbonate was treated in the same manner as in Example 1 except that the first active treatment for silver mirror containing stannous chloride and palladium sulfide was performed, and the silver mirror plating was performed without performing the second active treatment for silver mirror containing palladium sulfide. A silver mirror plating coating was obtained on the plate surface.

(Comparative Example 3)
After performing the first active treatment solution for silver mirror of Example 1 and thoroughly washing with deionized water, subsequently, a solution in which 0.03 mmol of palladium chloride was dissolved in phosphoric acid was made into 1 kg with deionized water. A silver mirror-plated coated body was obtained on the polycarbonate plate surface in the same manner as in Example 1 except that the treatment was performed and silver mirror plating was performed without performing the second active treatment for silver mirrors containing palladium sulfide.

(Comparative Example 4)
The surface of the polycarbonate plate in the same manner as in Comparative Example 1 except that the catalyzer accelerator method in which an activation treatment solution containing sulfuric acid was contacted after the first activation treatment containing stannous chloride and palladium chloride in Comparative Example 1 was performed. A silver mirror plating coating was obtained.

<Evaluation Test Method> The following evaluation tests were conducted on the silver mirror plating coated bodies obtained in Examples 1-3 and Comparative Examples 1-4. The results are shown in Table 1.

1) Evaluation A (Adhesiveness)
Using a super cutter guide of TAIYU EQUIPMENT CO., LTD., Using a super cutter guide from the overcoat layer surface of the silver mirror plating coating body before the evaluation test, the cellophane tape was pressed strongly to reach the polycarbonate substrate. Then, it peeled and judged based on the following reference | standard.
○: Good without peeling.
(Triangle | delta): The coating film peeled slightly.
X: The coating film was peeled off.

2) Evaluation B (Adhesiveness after wet heat resistance test)
Using CONSTANT LOW TEMPERATURE / HUMIDITY CHAMBER THN054PB manufactured by Advantech, it was stored in an environment of 65 ° C. and 95% RH for 10 days, left at room temperature for 2 hours, then subjected to cross-cutting in the same manner as in Evaluation A, and evaluated in the same manner.

3) Evaluation C (Adhesiveness after salt spray test)
A 5% saline solution was sprayed in a 35 ° C. environment with a salt spray tester, model STP-90, from Suga Test Co., Ltd., and a 5 day salt spray test was conducted.

4) Evaluation D (Adhesiveness after salt spray test)
The coated body in which a cross cut was put in the same manner as in the evaluation A was subjected to a salt spray test in the same manner as in the evaluation C. The cellophane tape was pressed and peeled in the same manner as in the above evaluation A, and the evaluation was similarly performed.

  As is apparent from the evaluation results, the present invention makes it possible to obtain a silver mirror-plated coated body with almost no decrease in adhesion between the undercoat layer and the silver mirror-plated layer with respect to heat, humidity, and salt water. It can be widely used indoors and outdoors as a material with excellent design properties, a reflective material, an electromagnetic shielding material, and the like.

Claims (2)

  Second active treatment liquid for silver mirror containing sulfide of heavy metal.   The step of treating the undercoat layer provided on the surface of the substrate with a first active treatment solution for silver mirror containing stannous chloride, the undercoat layer treated with the stannous chloride containing a heavy metal sulfide A step of treating with a second active treatment solution for a silver mirror, a step of forming a silver thin film layer by a silver mirror reaction on the undercoat layer treated with the heavy metal sulfide, and a top coat layer on the silver thin film layer A silver thin film forming method comprising at least a step.