JP2013159649A - Solvent composition and silver mirror film laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solvent composition capable of improving blistering defects generated when a top coat layer is installed on a silver mirror film, and also a silver mirror film laminate capable of improving decrease in the adhesion of the silver mirror film.SOLUTION: A solvent composition incorporated in a coating material for forming a top coat on a silver mirror film is provided by containing 7.5 to 50 mass% ketone-based solvent having 133 to 180°C boiling point. The silver mirror film laminate having the top coat layer formed by applying the coating material incorporated with the solvent composition is also provided.

Description

  The present invention relates to a solvent composition to be contained in a paint for forming a topcoat layer on a silver mirror coating, and a silver mirror coating laminate. More specifically, the present invention relates to a solvent composition from which a silver mirror coating laminate without a blister failure can be obtained, and a silver mirror coating laminate excellent in adhesiveness of the silver mirror coating.

  A laminate having a silver thin film (hereinafter referred to as a silver mirror coating) obtained by a silver mirror reaction has an excellent metallic luster, and therefore 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 mirror film has. Silver mirror coatings are often provided with a hard coat material as a topcoat layer on the coating surface because the surface is easily damaged and is easily altered in the air.

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

  However, when the above-mentioned various curable topcoat layers are provided on the silver mirror coating, a fine hole is formed in the silver mirror coating, and a defect (hereinafter referred to as a blistering defect) appears that the entire portion is swollen. There has been a problem that the designability and reflectivity are significantly lowered. Moreover, when the silver mirror film laminated body which provided the above-mentioned various curable topcoat layers on a silver mirror film was preserve | saved for a long time, there existed a problem that the adhesiveness of a silver mirror film fell.

  In Examples such as Japanese Patent Application Laid-Open No. 2004-190061, Japanese Patent Application Laid-Open No. 2008-192431, and Japanese Patent Application Laid-Open No. 2007-169585, a top coat layer is formed by mixing a commercially available top coat agent, a curing agent, and thinner. However, the composition of the thinner is not described, but it is described that a top coat layer is provided by spraying the paint onto the silver mirror coating.

  In JP 2007-23087 A (Patent Document 1), when a top coat layer is provided on a silver mirror coating, a commercially available cured resin, a leveling agent, and a diluent solvent (toluene / butyl acetate / methoxypropyl acetate = 10/20 / 70) is mixed to provide a topcoat layer. JP-A-2005-1193 (Patent Document 2) discloses n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, n-heptane, as an organic solvent contained in the coating material for forming the topcoat layer used on the silver mirror coating. Aliphatic hydrocarbons such as n-octane and mineral spirits; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and isobutyl alcohol ; Esters such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, hexyl acetate, heptyl acetate, octyl acetate, cellosolve acetate; acetone, methyl ethyl ketone, methyl isobutyl Ton, methyl amyl ketone, cyclohexanone, ketones such as isophorone, a mixture thereof or the like is described.

  On the other hand, in the thermosetting water-based paint, the main component of the solvent contained in the paint is water, and although the boiling point of this water is low, blistering defects are likely to occur due to foaming during heat curing due to large latent heat of vaporization. It is known. For example, Japanese Patent Publication No. 02-390 (Patent Document 3) and Japanese Patent Application Laid-Open No. 04-93374 (Patent Document 4) include benzoin methyl ether, benzoin ethyl ether, and benzoin-n-propyl ether. C1-C4 alkyl etherates of benzoin such as benzoin-iso-propyl ether, benzoin-n-butyl ether, and benzoin-iso-butyl ether are known.

  However, it is extremely difficult to improve the above-described blistering defects and the decrease in the adhesiveness of the silver mirror coating when stored for a long time, and a solution has been demanded.

JP 2007-23087 A JP 2005-1193 A Japanese Patent Publication No. 02-390 Japanese Patent Laid-Open No. 04-93374

  The subject of this invention is providing the solvent composition which can improve the blistering defect which arises when a topcoat layer is provided on a silver mirror film. Another object of the present invention is to provide a silver mirror coating laminate capable of improving the deterioration in adhesion of the silver mirror coating that occurs when a silver mirror coating laminate having a top coat layer provided on the silver mirror coating is stored for a long period of time.

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 solvent composition containing 7.5 to 50% by mass of a ketone solvent having a boiling point of 133 to 180 ° C., which is contained in a paint for forming a topcoat layer on a silver mirror film.
(2) A top formed by applying a paint containing a solvent composition containing 7.5 to 50% by mass of a ketone solvent having a boiling point of 133 to 180 ° C. on a silver mirror coating provided on a substrate. A silver mirror coating laminate having a coating layer.

  According to the present invention, it is possible to provide a solvent composition capable of improving blistering defects generated when a topcoat layer is provided on a silver mirror coating. Moreover, the silver mirror coating laminated body which can improve the adhesive fall of the silver mirror coating which generate | occur | produces when the silver mirror coating laminated body which provided the topcoat layer on the silver mirror coating was preserve | saved for a long period can be provided.

The present invention is described in detail below.
The solvent composition of the present invention, which is included in the paint for forming the top coat layer on the silver mirror coating, is 7.5 to 50% by mass of a ketone solvent having a boiling point of 133 to 180 ° C. with respect to 100% by mass of the solvent composition. contains. A more preferable boiling point of the ketone solvent is 150 to 170 ° C., and a more preferable content of the ketone solvent is 10 to 40% by mass. Thereby, the improvement effect of a blistering defect becomes more remarkable.

  Examples of the ketone solvent having a boiling point of 133 to 180 ° C. contained in the solvent composition of the present invention include methyl-n-amyl ketone (boiling point 150.2 ° C.) and methyl-n-hexyl ketone (boiling point 172.9 to 173.173). 5 ° C), ethyl-n-butylketone (boiling point 147.8 ° C), diisobutylketone (boiling point 168.1 ° C), diacetone alcohol (boiling point 167.9 ° C), cyclohexanone (boiling point 155.7 ° C), methylcyclohexanone ( Boiling point of 169.0 to 170.5 ° C.) and the like. These may be contained alone or in combination. However, if cyclic ketones such as cyclohexanone and methylcyclohexanone are used in a large amount, the effect of improving blistering defects may be reduced. Therefore, the cyclic ketone in the solvent composition is preferably 10% by mass or less. Further, when diacetone alcohol is used in a large amount, the top coat layer may be discolored. Therefore, it is preferably used at 20% by mass or less.

  Other organic solvents contained in the solvent composition of the present invention include, for example, cyclohexane, Solvesso 100 (trade name, manufactured by Exxon Chemical), hydrocarbons such as normal heptane, cellosolve, methyl cellosolve, butyl cellosolve, carbitol, Ethers such as diethyl carbitol, alcohols such as methanol, ethanol, isopropyl alcohol, tertiary butanol, n-butanol, cyclohexanol, 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, metho Esters such as butyl butyl acetate, methyl ethoxy acetate, ethyl ethoxy acetate, isobutyl isobutyrate, 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 Examples include ethers such as monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, etc. Absent.

  The other organic solvents described above are appropriately selected depending on the solubility of various components such as a resin component and a curing agent contained in the coating material forming the topcoat layer, but from the viewpoint of the surface quality of the formed topcoat layer, other It is desirable to use two or more organic solvents in combination, and it is preferable to use a solvent having a boiling point of 125 ° C. or higher and a solvent having a boiling point of less than 125 ° C. in combination. Moreover, in that case, it is preferable that the ratio of the solvent whose boiling point occupies in another solvent is less than 125 degreeC is 50 mass% or more.

Next, the silver mirror coating laminate of the present invention will be described.
Various plastics, metals, glasses, rubbers and the like are used as the base material of the silver mirror coating laminate of the present invention. 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.

  The silver mirror coating laminate of the present invention preferably has an undercoat layer on the substrate, but the substrate may be pretreated in order to improve the adhesion between the substrate and the undercoat layer. . 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.

  The undercoat layer is required to have good adhesion to the substrate and excellent adhesion to the silver mirror coating 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 characteristics required for the substrate or 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 the substrate cannot be dried at a high temperature of 100 ° C. or more due to deformation and shrinkage of the substrate, a curing accelerator may be added to the undercoat layer, 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 Co., Ltd., and BYK Co., Ltd. If more leveling agents are used, adhesion between the undercoat layer and the silver mirror plating layer Care must be taken because it causes a drop. 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%.

  Examples of the organic solvent used for providing the undercoat layer include a ketone solvent having a boiling point of 133 to 180 ° C. and other organic solvents that can be used in combination with the coating material for forming the topcoat layer. However, it is not limited to this. These organic solvents are selected from the viewpoint of the solubility of the components contained in the undercoat layer, the surface quality of the undercoat layer, and the like, and can be used alone, but can be used in combination of two or more. preferable.

  In order to form a silver mirror coating on the undercoat layer, the surface of the substrate, preferably the undercoat layer provided on the substrate surface, is treated with a first active treatment solution for silver mirrors containing stannous chloride. Thereby, stannous ions are supported on the surface of the substrate, preferably on the surface of the undercoat layer. As the method, there are a method of immersing the substrate in the first active treatment liquid for silver mirror, a method of applying the first active treatment liquid for silver mirror to 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.

  You may provide the process of performing silver ion processing following the process of processing with the 1st active processing liquid for silver mirrors. 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.

  Further, the undercoat layer treated with the treatment solution containing stannous chloride and silver nitrate was treated with a second active treatment solution for silver mirror containing 0.001 to 0.3 mmol / kg of heavy metal sulfide. Also good.

  Heavy metal sulfides contained in the second active treatment liquid for silver mirror include sulfides such as silver, antimony, bismuth, cadmium, cobalt, lead, nickel, palladium, rhodium, gold, platinum, polysulfides, or those A mixture, a mixed crystal, etc. are mentioned. Among these, 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. For these activation processes, spray coating in which a new solution is always supplied is suitable.

  A silver mirror film is formed on the substrate treated with the above active treatment liquid, preferably on the undercoat layer. The silver mirror coating is applied by applying two solutions, an ammoniacal silver nitrate solution containing silver nitrate and ammonia, and a reducing agent solution containing a reducing agent and a strong alkali component so that they are mixed on the surface that has been subjected to the above treatment. As a result, metallic silver is deposited to form a silver mirror coating.

  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 mirror coating with deionized water or purified distilled water to remove the solution after the silver mirror reaction remaining on the surface. Further, before the top coat layer is provided on the silver mirror coating, in order to stabilize the deposited metallic silver, a treatment such as immersion in a solution containing an organic compound that reacts with or has affinity with silver is applied. be able to.

  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-mercapto-benzoxazo 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 1-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 mirror coating. A thermosetting resin is generally used as the resin composition constituting the top coat layer, 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 (meth) Acrylates of phenolic alkylene oxide adducts such as acrylates and their halogen nucleus substitutes; mono- or di (meth) acrylates of ethylene glycol, mono (meth) acrylates of methoxyethylene glycol, mono- or di (meth) of tetraethylene glycol Mono- or di (meth) acrylates of glycol, such as acrylate, mono- or di (meth) acrylate of tripropylene glycol; trimethylolpropane tri (meth) acrylate, (Meth) acrylic ester of polyols such as taerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate and dipentaerythritol hexaacrylate and alkylene oxides thereof, 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-tertiary butyl anthraquinone, 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 20 μm. If the layer is too thin, the function of protecting the silver mirror film 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 top coat layer can be toned by further containing a colorant such as a pigment or a dye. It is more preferable that the absorption wavelength of the color material does not include the absorption wavelength of the photopolymerization initiator because it does not hinder the activity of the photopolymerization initiator. 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 amount of the dye added is not particularly limited because the concealability varies depending on the type of the dye, but is preferably 0.005 to 4% by mass, and 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.

  In the present invention, as a method for providing the topcoat layer on the silver mirror coating, a solvent composition containing 7.5 to 50% by mass of a ketone solvent having a boiling point of 133 to 180 ° C. in the paint forming the topcoat layer. It is preferable to provide a topcoat layer by coating the paint on the silver mirror coating. As a coating method, a conventionally known coating method may be used. For example, 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 be used. The undercoat layer described above can also be applied by these application methods.

  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 transparent polycarbonate plate was degreased, washed with water and dried. Commercially available undercoat paint (under clear No. 0128 manufactured by Ohashi Chemical Co., Ltd.) and isocyanate curing agent (under clear curing agent -N manufactured by Ohashi Chemical Co., Ltd.) and thinner (methyl ethyl ketone and butyl cellsolve in a ratio of 1: 1. Were mixed at a ratio (mass ratio) of 10: 2: 10, respectively, and applied to the surface of the transparent polycarbonate plate using a spray gun. Thereafter, it was heated and dried at 80 ° C. for 1 hour to form an undercoat layer having a thickness of 20 μm.

  First activation treatment 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 on the undercoat layer with a spray gun, and then activated. Washed with ionic water.

  Following the step of treating with the first active treatment solution for silver mirror described above, silver ion treatment was performed. A 0.05 mol / kg silver nitrate aqueous solution was used for the silver ion treatment, and the aqueous solution was sprayed onto the surface treated with the silver mirror first activation treatment solution with a spray gun in the same manner as the silver mirror first activation treatment solution.

  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 simultaneously sprayed onto the surface of the silver ion-treated substrate using a double-head spray gun to form a silver mirror film, and washed with deionized water. Then, it was dried in a dryer at 70 ° C. for 30 minutes.

  Next, a top coat layer was provided on the silver mirror coating. Omak No. 2 based on two-component curable acrylic silicon resin manufactured by Ohashi Chemical Industries 100 (E), obtained by mixing the solvent composition (A) of the present invention described in Table 1 and Omak curing agent E (for high hardness) at a ratio (mass ratio) of 4: 4: 1, respectively. The coated paint was used as a top coat paint, and the paint was spray applied onto the silver mirror film using a spray gun. Then, it heat-dried at 80 degreeC for 30 minutes, and obtained the silver mirror film laminated body which has a 15-micrometer-thick topcoat layer.

(Examples 2 to 7)
In Example 1, it replaces with the solvent composition (A) which a topcoat paint contains, It carries out similarly to Example 1 except using the solvent composition (B)-(G) of Table 1, respectively. A silver mirror coating laminate was obtained.

(Comparative Examples 1-9)
In Example 1, it replaced with the solvent composition (A) which a topcoat paint contains, and it carried out similarly to Example 1 except using the solvent composition (H)-(P) of Table 1, respectively. A silver mirror coating laminate was obtained.

<Evaluation test method>
The following evaluation tests were performed on the silver mirror coating laminates obtained in Examples 1 to 7 and Comparative Examples 1 to 9. The results are shown in Table 2.

1) Evaluation A (blowing failure)
The topcoat layer of the silver mirror coating laminate was observed using an optical microscope KEYENCE DIGITAL MICROSCOPE VHX-500F. In order to discriminate between a blister failure and a failure due to dust, observation was performed while confirming whether or not the silver mirror coating appeared to have a hole. Moreover, since the thing of 30 micrometers or more size can also be confirmed with the naked eye, it determined based on the following reference | standard.
○: Good with no bulging failure even with the naked eye or optical microscope.
Δ: Swelling failure is not visible with the naked eye, but can be slightly confirmed with an optical microscope.
X: Swelling can be confirmed with the naked eye.

2) Evaluation B (Adhesiveness after wet heat resistance test)
Use Advantech's CONSTANT LOW TEMPERATURE / HUMIDITY CHAMBER THN054PB, store it at 65 ° C and 95% RH for 3 days, leave it at room temperature for 2 hours, and then apply it to the transparent polycarbonate plate from the overcoat layer surface of the silver mirror coating laminate. Using a super cutter guide of TAIYU EQUIPMENT Co., Ltd., crosscuts were made at intervals of 2 mm, cellophane tape was strongly pressed, peeled, and judged based on the following criteria.
○: No peeling of the silver mirror film.
Δ: Slight peeling of the silver mirror film is confirmed.
X: Peeling of the silver mirror film is confirmed.

3) Evaluation C (Adhesiveness after salt spray test)
A salt spray tester, Model STP-90, from Suga Test Co., Ltd. was sprayed with 5% saline in a 35 ° C. environment to conduct a salt spray test for 3 days.

  As is apparent from the evaluation results, the solvent composition of the present invention can improve the blistering failure that occurs when the topcoat layer is formed on the silver mirror coating. Moreover, it turns out that the silver mirror film laminated body of this invention is excellent in the adhesiveness of a silver mirror film.

Claims (2)

  A solvent composition which is contained in a paint for forming a topcoat layer on a silver mirror coating, and contains 7.5 to 50% by mass of a ketone solvent having a boiling point of 133 to 180 ° C.   A top coat layer formed by applying a paint containing a solvent composition containing 7.5 to 50% by mass of a ketone solvent having a boiling point of 133 to 180 ° C. on a silver mirror film provided on a substrate. A silver mirror coating laminate.