JP7413314B2 - Silver gloss film and its manufacturing method - Google Patents

Description

The present invention relates to a silver luster film for metallically decorating various objects to be decorated, and a method for manufacturing the same.

Metallic decoration is needed in a wide range of fields, such as automobile interior and exterior parts, emblems, electronic devices, cosmetic containers, and golf club shafts. A high level of metallic luster is required. In particular, silver has a beautiful metallic luster (metallicity, glitter, specularity) due to its high light reflectance, and is expected to be a metal suitable for advanced design.

Techniques for imparting metallic luster to objects to be decorated include foil stamping, vapor deposition, silver mirror plating using silver mirror reaction, and chrome plating, as well as inks using aluminum pigments as bright pigments and inks containing metal nanoparticles. Examples include a method of forming a metallic luster layer on a base material by printing or coating.

Foil stamping, vapor deposition, silver mirror plating, and chrome plating can give a metallic luster close to that of metal, but these methods are disadvantageous in terms of manufacturing costs because the manufacturing process is complicated and special equipment is required. It is. In addition, silver mirror plating has a high defect rate due to whitening, cracking, and uneven coloring that are characteristic of plating, and because parts other than those to be plated are plated. Furthermore, chrome plating has a large impact on the environment. In contrast to these methods, methods such as printing and coating using ink have lower manufacturing costs and can be applied to a wide range of base materials.

Among inks, a metallic luster layer made of an ink containing metal nanoparticles has better metallic luster than an ink using an aluminum pigment (bright pigment).

JP-A-2009-227736 (Patent Document 1) contains metal colloid particles formed of metal nanoparticles and a dispersant; and a solvent (B), and the dispersant contains an organic compound having a carboxyl group and a polymer. Inkjet printing ink compositions are described that include molecular dispersants. This document also describes that additives such as binder resins (hydrophilic polymers such as polyvinyl alcohol and polyethylene glycol) may be added.

JP 2017-149942A (Patent Document 2) discloses an ink composition for printing or printing on a printing material, which includes silver nanoparticles, a dispersant having a carboxyl group or a salt thereof, and an aqueous solvent. discloses an ink composition containing 1 to 30 parts by mass of a water-soluble or water-dispersible polymer having a film-forming ability based on 100 parts by mass of silver nanoparticles in terms of solid content. .

JP 2018-153965A (Patent Document 3) discloses an image formed product having a base material and a metallic luster layer formed on the base material, wherein the metallic luster layer includes metal nanoparticles and the metallic luster layer formed on the base material. The polymer dispersant is a compound having an acid value of 1 or more and 80 or less, and the binder resin has an SP value of 23. An image-formed product is disclosed in which the resin has a molecular weight of 0 or more and 26.0 or less. This document describes the binder resin as polyvinyl alcohol having a saponification degree of 72 or more and 85 or less.

JP 2018-145319 A (Patent Document 4) discloses that first resin particles containing water, a water-soluble organic solvent with a boiling point of 250° C. or less, a glitter pigment, and a vinyl polymer, and second resin particles are used. An ink containing the invention is disclosed. This document describes a silver colloid particle dispersion as a glittering pigment.

JP 2019-116522A (Patent Document 5) discloses an ink containing silver particles having a particle size Dav90 of 45 nm or less, a polyol, a silicone surfactant, and a resin. This document describes that the ink contains a water-soluble resin or a water-dispersible resin.

JP 2017-2219 A (Patent Document 6) discloses an alcohol solution in which a polymer dispersant is dissolved in an alcohol solvent and at least one silver compound selected from silver oxide and silver carbonate is dispersed. A composition liquid for forming a silver mirror film layer is disclosed, which is made of a dispersion solution of silver nanoparticles and obtained by irradiating ultrasonic waves into the alcohol solution.

Japanese Patent Application Publication No. 2009-227736 Japanese Patent Application Publication No. 2017-149942 Japanese Patent Application Publication No. 2018-153965 Japanese Patent Application Publication No. 2018-145319 JP2019-116522A JP 2017-2219 Publication

However, in the inks using metal nanoparticles disclosed in Patent Documents 1 to 6, if the amount of resin such as a binder is increased, metallic luster (silver luster) cannot be obtained. It was necessary to reduce the amount as much as possible. If the amount of resin is reduced, the adhesion to the base material and scratch resistance will decrease, so it has been necessary to use the resin in combination with an overcoat layer and an undercoat layer. That is, since there is a trade-off relationship between metallic luster and adhesion, it has been difficult to achieve both properties using a simple method.

Therefore, an object of the present invention is to provide a silver gloss film that can achieve both silver luster, adhesion, and scratch resistance, and a method for producing the same.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have discovered that composite nanoparticles (a) of a metal containing silver and a protective colloid are formed on a base material (or an object to be decorated). an interface layer (A), a first phase containing composite nanoparticles (b1) of a metal containing silver and a protective colloid, a first resin (b2), composite nanoparticles (b3) of silver and a protective colloid, and An intermediate layer (B) having a phase-separated structure including a second resin (b4) and a second phase containing less silver than the first phase; a composite of a metal containing silver and a protective colloid; The present invention was completed based on the discovery that by having a structure in which the surface layer (C) formed of body nanoparticles (c) is sequentially laminated, silver luster, adhesion, and scratch resistance can be achieved at the same time.

That is, the silver luster film of the present invention is a silver luster film laminated on a base material,
an interface layer (A) laminated on the base material and formed of composite nanoparticles (a) of a metal containing silver and a protective colloid;
A first phase that is laminated on this interface layer (A) and includes composite nanoparticles (b1) of a metal containing silver and a protective colloid and a first resin (b2), and a metal containing silver and a protective colloid. An intermediate layer (B) having a phase-separated structure comprising composite nanoparticles (b3) of )and,
A surface layer (C) is laminated on the intermediate layer (B) and is formed of composite nanoparticles (c) of a metal containing silver and a protective colloid.

The phase separation structure of the intermediate layer (B) may be a sea-island structure. The first phase or the second phase may be a dispersed phase, and the dispersed phase may have an average diameter of 30 to 500 nm. The surface layer (C) and the interface layer (A) may each have an average thickness of 10 to 200 nm. The average thickness of the intermediate layer (B) may be 25 to 250 times the average thickness of the surface layer (C).

The present invention includes a coating step of coating a substrate with a liquid composition containing composite nanoparticles of a metal containing silver and a protective colloid, a first resin, a second resin, and a solvent; The present invention also includes a method for producing the silvery glossy film, which includes a phase separation step of drying the formed coating film and phase-separating it by spinodal decomposition to obtain a silvery glossy film.

The present invention also includes a decorative body in which the silver luster film is laminated on a base material.

In the present invention, an interface layer (A) formed of composite nanoparticles (a) of a metal containing silver and a protective colloid is formed on a base material or an object to be decorated; A first phase containing composite nanoparticles (b1) and a first resin (b2), a composite nanoparticle (b3) of a metal containing silver and a protective colloid, and a second resin (b4), containing silver. An intermediate layer (B) having a phase-separated structure in which the second phase has a lower metal content than the first phase, and a composite nanoparticle (c) of a metal containing silver and a protective colloid. Since the surface layer (C) has a structure in which the surface layers (C) are sequentially laminated, it is possible to achieve both the silver luster, adhesion, and scratch resistance of the silver luster film. Specifically, it is possible to form a silver glossy film with high adhesion on the object to be decorated without separately forming a topcoat layer or undercoat layer, so it is possible to improve adhesion with a simple method and also improve scratch resistance. You can improve. Furthermore, since the film surface forms a dense surface layer of silver-containing nanoparticles, it has a high light shielding property (non-transmission) and can improve silver luster (mirror surface).

FIG. 1 shows a transmission electron microscope (TEM) image of a cross section of the silver glossy film obtained in Example 1. FIG. 2 is an enlarged image of the TEM image of FIG. 1 near the surface. FIG. 3 is an enlarged image of the TEM image of FIG. 1 near the interface with the base material. FIG. 4 is an enlarged image of the TEM image of FIG. 1 near the center of the film thickness. FIG. 5 shows a TEM image of a cross section of the silver glossy film obtained in Example 2. FIG. 6 is an enlarged image of the vicinity of the surface in the TEM image of FIG. FIG. 7 is an enlarged image of the vicinity of the interface with the base material in the TEM image of FIG. FIG. 8 is an enlarged image of the TEM image of FIG. 5 near the center of the film thickness. FIG. 9 shows a TEM image of a cross section of the silver glossy film obtained in Example 3. FIG. 10 is an enlarged image of the TEM image of FIG. 9 near the surface. FIG. 11 is an enlarged image of the vicinity of the interface with the base material in the TEM image of FIG. FIG. 12 is an enlarged image of the TEM image of FIG. 9 near the center of the film thickness. FIG. 13 shows a TEM image of a cross section of the silver glossy film obtained in Example 4. FIG. 14 is an enlarged image of the TEM image of FIG. 13 near the surface. FIG. 15 is an enlarged image of the TEM image of FIG. 13 near the interface with the base material. FIG. 16 is an enlarged image of the TEM image of FIG. 13 near the center of the film thickness. FIG. 17 shows a TEM image of a cross section of the silver glossy film obtained in Example 5. FIG. 18 is an enlarged image of the TEM image of FIG. 17 near the surface. FIG. 19 is an enlarged image of the TEM image of FIG. 17 near the interface with the base material. FIG. 20 is an enlarged image of the TEM image of FIG. 17 near the center of the film thickness. FIG. 21 shows a TEM image of a cross section of the silver glossy film obtained in Example 6. FIG. 22 is an enlarged image of the TEM image of FIG. 21 near the surface. FIG. 23 is an enlarged image of the TEM image of FIG. 21 near the interface with the base material. FIG. 24 is an enlarged image of the TEM image of FIG. 21 near the center of the film thickness. FIG. 25 shows a TEM image of a cross section of the silver glossy film obtained in Example 7. FIG. 26 is an enlarged image of the TEM image of FIG. 25 near the surface. FIG. 27 is an enlarged image of the TEM image of FIG. 25 near the interface with the base material. FIG. 28 is an enlarged image of the TEM image of FIG. 25 near the center of the film thickness. FIG. 29 shows a TEM image of a cross section of the silver glossy film obtained in Example 8. FIG. 30 is an enlarged image of the TEM image of FIG. 29 near the surface. FIG. 31 is an enlarged image of the TEM image of FIG. 29 near the interface with the base material. FIG. 32 is an enlarged image of the TEM image of FIG. 29 near the center of the film thickness. FIG. 33 shows a TEM image of a cross section of the silver glossy film obtained in Comparative Example 1. FIG. 34 is an enlarged image of the TEM image of FIG. 33 near the surface. FIG. 35 is an enlarged image of the vicinity of the interface with the base material in the TEM image of FIG. 33. FIG. 36 is an enlarged image of the TEM image of FIG. 33 near the center of the film thickness. FIG. 37 shows a TEM image of a cross section of the silver glossy film obtained in Comparative Example 2. FIG. 38 is an enlarged image of the TEM image of FIG. 37 near the surface. FIG. 39 is an enlarged image of the TEM image of FIG. 37 near the interface with the base material. FIG. 40 is an enlarged image of the TEM image of FIG. 37 near the center of the film thickness.

[Silver gloss film]
The silver luster film of the present invention has a structure in which an interface layer (A), an intermediate layer (B), and a surface layer (C) are sequentially laminated on an object to be decorated (base material). The mechanism by which such a laminated structure can achieve both metallic luster (silver luster) and scratch resistance can be estimated as follows.

That is, in the intermediate layer (B), a phase-separated structure (sea-island structure, co-continuous structure, etc.) is formed into a phase containing a relatively large amount of composite nanoparticles and a phase containing only a small amount, and The surface layer (C) and interface layer (A) have a structure in which the composite nanoparticles are arranged or oriented, which increases the shielding effect (non-transparent) and produces a high degree of silver luster (mirror surface). .

On the other hand, in conventional silver luster films containing only one type of resin component, metal particles such as silver-containing nanoparticles are uniformly dispersed throughout the film (silver-containing nanoparticles It can be inferred that since there is no concentrated area of metal particles that can block light, light easily passes through and silver luster cannot be obtained. Note that even if there is no phase separation of the resin component, the metal particles and the resin component may undergo phase separation, and in this case, it can be assumed that cloudiness occurs and the metallic luster disappears.

Furthermore, in addition to silver gloss, a silver gloss film requires adhesion and scratch resistance. Adhesion and scratch resistance can be improved by using a resin component (binder), but on the other hand, as the resin component increases, the proportion of silver decreases, so the light shielding effect of silver decreases and the silver luster decreases. descend. In the present invention, in the intermediate layer, the composite nanoparticles are unevenly distributed by the two types of resin components, and a phase that can shield light (a phase containing a relatively large amount of composite nanoparticles) is formed. High silver luster is achieved even when blended with . That is, by blending a large amount of resin component while maintaining a high degree of silver luster, adhesion and scratch resistance can be improved. Furthermore, topcoating and undercoating are no longer necessary, resulting in a simple structure that improves productivity and allows coating on various objects to be decorated (substrates or molded objects).

On the other hand, in conventional silver gloss films, when the proportion of the resin component is small (the amount of the resin component relative to silver is about 10% by mass or less), the gloss is high, but the adhesion and scratch resistance are low. Therefore, a topcoat layer and an undercoat layer were often required. On the other hand, when the proportion of the resin component was high (the amount of the resin component relative to silver was about 10% by mass or more), the adhesion and scratch resistance improved, but the gloss decreased. Therefore, in conventional silver luster inks, it is necessary to keep the amount of resin relative to silver small, and the amount of resin component relative to silver is about 10% by mass at most, and it has a simple structure with good adhesion and scratch resistance. could not be improved.

(A) Interface layer The interface layer (A) is formed of composite nanoparticles (a) of a metal containing silver (silver-containing metal) and a protective colloid, and the composite nanoparticles (a) are The metal containing silver forms a dense thin film (silver-containing metal thin film) by being aligned or oriented at the interface with the metal. In the present invention, by forming such an interface layer (A) at the interface with the base material, it is possible to improve the silver luster from the back side of the transparent base material.

The average thickness of the interface layer (A) may be 300 nm or less, for example 3 to 300 nm, preferably 10 to 200 nm, more preferably 10 to 100 nm, more preferably 15 to 50 nm, most preferably 20 to 40 nm. . If the average thickness of the interface layer (A) is too thick, there is a possibility that the adhesion will be reduced.

In addition, in this application, the average thickness of the interface layer (A) can be measured by observing the cross section of the silver glossy film with a transmission electron microscope (TEM), and in detail, it can be measured by the method described in the Examples below. .

(a) Composite nanoparticles In the composite nanoparticles (a), the composite form of the silver-containing metal and the protective colloid is not particularly limited, and is a composite attached or coordinated to the surface of the silver-containing metal nanoparticles. Alternatively, it may be a composite in which the surface of silver-containing metal nanoparticles is coated. Silver-containing metal nanoparticles have a high coordination ability with respect to protective colloids (or dispersants), so when the protective colloid coordinates to the surface of silver-containing metal nanoparticles, a composite coated with silver-containing metal nanoparticles can be formed. There may be. When the silver-containing metal nanoparticles are composited with a protective colloid, the dispersion stability of the silver-containing metal nanoparticles can be improved, and the affinity with the resin component can be easily adjusted, so that a phase-separated structure can be formed.

(Silver-containing metal nanoparticles)
The silver-containing metal nanoparticles are nanometer sized. The number average particle size (number average primary particle size) of the silver-containing metal nanoparticles is, for example, 1 to 100 nm (for example, 2 to 80 nm), preferably 3 to 70 nm (for example, 4 to 50 nm), more preferably 5 to 40 nm (especially 10-30 nm).

The silver-containing metal nanoparticles have the above average particle size and exhibit a wide particle size distribution in the range of 200 nm or less, but may contain almost no coarse particles exceeding 200 nm. Therefore, the maximum primary particle size of the silver-containing metal nanoparticles is, for example, 200 nm or less, preferably 150 nm or less, and more preferably 100 nm or less.

In the silver-containing metal nanoparticles, the proportion of particles having a primary particle diameter of 100 nm or more is, for example, 10% by mass or less (for example, 0 to 8% by mass), preferably 5% by mass or less (for example, 0.01 to 3% by mass). % by mass), more preferably 1% by mass or less (for example, 0.02 to 0.5% by mass).

In addition, in this application, the particle size and particle size distribution of silver-containing metal nanoparticles can be measured using a transmission electron microscope, and the average particle size is shown as an average value of ten arbitrary particles.

(Metals including silver)
The metal containing silver (silver-containing metal) may be simple silver or may be an alloy of silver and other metals. Other metals are not particularly limited as long as they can be alloyed with silver, and examples thereof include Cr, Mo, W, Ni, Pd, Pt, Cu, Au, Zn, In, Sn, and Pb. These other metals can be used alone or in combination of two or more. Among these other metals, Cu is preferred.

Among the silver-containing metals, the proportion of silver may be 50% by mass or more, for example 90% by mass or more, preferably 95% by mass or more, more preferably 97% by mass or more, more preferably 99% by mass or more. % by mass or more, most preferably 100% by mass (single silver). If the proportion of silver is too low, there is a risk that the silver luster will be reduced.

(protective colloid)
Protective colloids may be dispersants, and are often non-volatile dispersants. In particular, the protective colloid preferably contains a polymeric dispersant having a carboxyl group or a salt thereof. In addition, in this application, the carboxyl group also includes a carboxyl group in the form of an acid anhydride group.

The polymer dispersant (or polymer type dispersant) may have at least a carboxyl group and be capable of dispersing silver-containing metal nanoparticles, and may be an amphiphilic polymer dispersant (or oligomer type dispersant). It may be.

Examples of the polymer dispersant include polymer dispersants that are commonly used for dispersing colorants in the paint and ink fields. Typical polymeric dispersants (amphiphilic polymeric dispersants) include water-soluble or water-dispersible resins containing hydrophilic units (or hydrophilic blocks) formed from hydrophilic monomers.

Examples of the hydrophilic monomer include carboxyl group-containing monomers (unsaturated polycarboxylic acids such as (meth)acrylic acid, maleic acid, and maleic anhydride, or acid anhydrides thereof), monomers having sulfo groups, etc. addition-polymerizable monomers such as hydroxyl group-containing monomers (hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, vinyl phenol, etc.); condensation-polymerizable monomers such as ethylene oxide; For example, The condensation polymerizable monomer may form a hydrophilic unit (or block) by reaction with active hydrogen such as a hydroxyl group (for example, the hydroxyl group). The hydrophilic monomers may be used alone or in combination of two or more to form a hydrophilic unit (or block). Preferred hydrophilic monomers are (meth)acrylic acid, maleic acid, maleic anhydride, and ethylene oxide.

The polymer dispersant only needs to have at least a carboxyl group, and may have a functional group of the hydrophilic monomer, such as an acid group (sulfo group) or a hydroxyl group. These functional groups may be introduced into the polymer dispersant singly or in combination of two or more.

The polymeric dispersant may contain at least a hydrophilic unit (or hydrophilic block), may be a single or copolymer of hydrophilic monomers (for example, polyacrylic acid or a salt thereof, etc.), and may be a hydrophilic monomer. It may also be a copolymer of a hydrophobic monomer and a hydrophobic monomer. Hydrophobic monomers (nonionic monomers) include (meth)acrylic esters [methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate; , C _1-20 alkyl (meth)acrylates such as lauryl (meth)acrylate and stearyl (meth)acrylate, cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, phenyl (meth)acrylate, etc. (meth)acrylic monomers such as aryl (meth)acrylate, benzyl (meth)acrylate, aralkyl (meth)acrylate such as 2-phenylethyl (meth)acrylate]; styrene, α-methylstyrene, Styrenic monomers such as vinyltoluene; Olefinic monomers such as α-C _2-20 olefins (ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-octene, 1-dodecene, etc.); vinyl acetate, vinyl butyrate addition-polymerizable monomers such as carboxylic acid vinyl ester monomers; and condensation-polymerizable monomers such as C _3-6 alkylene oxides such as propylene oxide. The hydrophobic monomers may be used alone or in combination of two or more to form a hydrophobic unit.

Polymeric dispersants for copolymers (e.g., copolymers of hydrophilic monomers and hydrophobic monomers) are random copolymers, alternating copolymers, block copolymers (e.g., hydrophilic blocks composed of hydrophilic monomers and hydrophobic monomers). (or a comb-shaped graft copolymer), or a comb-shaped copolymer (or a comb-shaped graft copolymer). The structure of the block copolymer is not particularly limited, and may be a diblock structure, a triblock structure (ABA type, BAB type), or the like. Further, in the comb-shaped copolymer, the main chain may be formed of the hydrophilic block or the hydrophobic block, or may be formed of the hydrophilic block and the hydrophobic block. A block copolymer of a hydrophilic block and a hydrophobic block can also improve silver luster.

Note that, as described above, the hydrophilic unit can also be formed from a hydrophilic block (such as polyalkylene oxide such as polyethylene oxide). The hydrophilic block (such as polyalkylene oxide) and the hydrophobic block (such as polyolefin block) may be bonded via a linking group such as an ester bond, amide bond, ether bond, or urethane bond. These bonds can be achieved, for example, by modifying hydrophobic blocks (such as polyolefins) with modifiers [unsaturated carboxylic acids or their anhydrides (such as maleic acid anhydride), lactams or aminocarboxylic acids, hydroxylamines, diamines, etc.] After that, it may be formed by introducing a hydrophilic block. In addition, a polymer obtained from a monomer having a hydrophilic group such as a hydroxyl group or a carboxyl group (such as the above-mentioned hydroxyalkyl (meth)acrylate) is reacted (or bonded) with the above-mentioned condensed hydrophilic monomer (such as ethylene oxide). In this way, a comb-shaped copolymer (a comb-shaped copolymer whose main chain is composed of hydrophobic blocks) may be formed.

Furthermore, the balance between hydrophilicity and hydrophobicity may be adjusted by using a hydrophilic nonionic monomer as a copolymerization component. Such components include monomers or oligomers having ethyleneoxy units such as 2-(2-methoxyethoxy)ethyl (meth)acrylate and polyethylene glycol mono(meth)acrylate (for example, number average molecular weight 200 to 1,000). Examples include: Furthermore, the balance between hydrophilicity and hydrophobicity may be adjusted by modifying (for example, esterifying) a hydrophilic group (such as a carboxyl group).

In a polymeric dispersant having a carboxyl group, the carboxyl group may be a salt or an acid anhydride group. For example, at least some of the carboxyl groups may form a salt (salt with an amine, metal salt, etc.). However, a polymeric dispersant in which acid groups such as carboxyl groups do not form salts (that is, polymeric dispersants having free carboxyl groups) can be preferably used.

The acid value of the polymer dispersant having a carboxyl group is, for example, 1 mgKOH/g or more (for example, 2 to 100 mgKOH/g), preferably 3 mgKOH/g or more (for example, 4 to 90 mgKOH/g), and more preferably 5 mgKOH/g or more ( For example, the amount may be 6 to 80 mgKOH/g), more preferably 7 mgKOH/g or more (for example, 8 to 50 mgKOH/g), and usually 3 to 30 mgKOH/g (especially 5 to 20 mgKOH/g). In addition, in such a polymeric dispersant, the amine value may be 0 (or almost 0).

In addition, in the said polymeric dispersant, the position of a functional group is not specifically limited, The main chain may be sufficient as it may be sufficient, and a side chain may be sufficient as it, and it may be located in a main chain and a side chain. Such a functional group may be, for example, a functional group derived from a hydrophilic monomer or a hydrophilic unit (for example, a functional group introduced by copolymerization of (meth)acrylic acid, maleic anhydride, ethylene oxide, etc.). good.

The polymer dispersants having carboxyl groups may be used alone or in combination of two or more.

As the polymer dispersant, a polymer dispersant (high molecular weight pigment dispersant) described in JP-A-2004-207558 and the like may be used. Further, the polymer dispersant may be synthesized or a commercially available product may be used. Specific examples of commercially available polymer dispersants (or dispersants made of at least amphiphilic dispersants) include Solsperse 13240, Solsperse 13940, Solsperse 32550, Solsperse 31845, Solsperse 24000, Solsperse 26000, Solsperse series such as Solsperse 27000, Solsperse 28000, Solsperse 41090 [manufactured by Avecia Co., Ltd.]; Disperbic 160, Disperbic 161, Disperbic 162, Disperbic 163, Disperbic 164, Disperbic 166, Disperbic 170, Disperbic Disperbic series [BIK Chemie ( EFKA-46, EFKA-47, EFKA-48, EFKA-49, EFKA-1501, EFKA-1502, EFKA-4540, EFKA-4550, Polymer 100, Polymer 120, Polymer 150, Polymer 400, Polymer 401, Polymer 402, Polymer 403, Polymer 450, Polymer 451, Polymer 452, Polymer 453 [manufactured by EFKA Chemical Co., Ltd.]; Ajisper series such as Ajisper PB711, Ajisper PAl11, Ajisper PB811, Ajisper PB821, Ajisper PW911 [Ajinomoto ( Floren series such as Floren DOPA-158, Floren DOPA-22, Floren DOPA-17, Floren TG-700, Floren TG-720W, Floren-730W, Floren-740W, Floren-745W [Kyoeisha Chemical Co., Ltd.]; (manufactured by Johnson Polymer Co., Ltd.); and Jonkryl series such as Jonkryl 678, Jonkryl 679, and Jonkryl 62 (manufactured by Johnson Polymer Co., Ltd.). Typical polymeric dispersants include Dispervic 190, Dispervic 194, Dispervic 2015, and the like.

The number average molecular weight of the polymer dispersant is, for example, 1,500 to 100,000, preferably 2,000 to 80,000 (for example, 2,000 60,000), more preferably 3,000 to 50,000 (for example 5,000 to 30,000), more preferably 7,000 to 20,000.

The polymer dispersant having a carboxyl group may be a polymer dispersant having no hydroxyl group.

The proportion of the protective colloid is, for example, 0.1 to 100 parts by weight (especially 1 to 50 parts by weight) per 100 parts by weight of the silver-containing metal. The proportion of the polymeric dispersant having a carboxyl group can be selected from a range of, for example, about 0.1 to 60 parts by mass (for example, 1 to 50 parts by mass), and usually 2 to 40 parts by mass, relative to 100 parts by mass of the silver-containing metal. parts (for example, 2.5 to 30 parts by weight), more preferably 3 to 25 parts by weight (especially 5 to 20 parts by weight).

In the present application, the proportion of the protective colloid in the composite nanoparticle (a) can be measured by a conventional method, for example, thermal analysis (for example, simultaneous thermogravimetric/differential thermal analysis).

The protective colloid may contain other dispersants, if necessary, and the other dispersants may be inorganic compounds, but are usually organic compounds. Other dispersants include, for example, alkanols ( _C6-20 alkane monools such as hexanol _, octanol, decanol, dodecanol, and octadecanol), aldehydes (C6-20 alkane monools such as capryaldehyde, laurylaldehyde, and palmitaldehyde). _-20 aliphatic aldehydes), aliphatic hydroxycarboxylic acids, higher fatty acids or their salts, and sulfonic acids (alkanesulfonic acids, benzenesulfonic acids, arenesulfonic acids such as toluenesulfonic acids, etc.). These other dispersants may be used alone or in combination of two or more.

The proportion of other dispersants is, for example, 0.1 to 100 parts by weight, preferably 0.5 to 50 parts by weight, and more preferably 1 to 30 parts by weight, based on 100 parts by weight of the polymeric dispersant.

The method for producing the composite nanoparticles is not particularly limited, and may be a conventional method. For example, when the silver-containing metal is simple silver, a silver compound corresponding to the silver nanoparticles is mixed in the presence of a protective colloid and a reducing agent, It can be prepared by reduction in a solvent. Specific manufacturing methods include, for example, the methods described in JP-A-2010-80442 and JP-A-2010-229544.

(B) Intermediate layer The intermediate layer (B) includes a first phase containing composite nanoparticles (b1) of a metal containing silver and a protective colloid and a first resin (b2), and a first phase containing a metal containing silver and a protective colloid. The composite nanoparticles (b3) and the second resin (b4) have a phase-separated structure in which the phase is separated into a second phase containing a smaller proportion of silver-containing metal than the first phase. By having a phase-separated structure in which the concentrations of silver-containing metals are different, even if the proportion of the resin component is increased, silver luster can be improved, and silver luster, adhesion, and scratch resistance can be achieved simultaneously.

(Phase 1)
In the first phase, the composite nanoparticles (b1) are the same as the composite nanoparticles (a) described in the section of the interface layer (A), including preferred embodiments, and are usually Same as nanoparticle (a).

The first resin (b2) is not particularly limited, and examples include polyolefin resins, (meth)acrylic resins, styrene resins, vinyl resins, polyvinyl acetal resins, polyester resins, polyamide resins, and polyurethane resins. Examples include resins, epoxy resins, and silicone resins. Among these, (meth)acrylic resins, polyvinyl acetal resins, and polyester resins are preferred, and (meth)acrylic resins and polyvinyl acetal resins are particularly preferred.

The (meth)acrylic resin is not particularly limited, and may be, for example, a single or copolymer of (meth)acrylic monomers, a (meth)acrylic polyol, or a modified (meth)acrylic resin.

Examples of (meth)acrylic monomers include (meth)acrylic acid; methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. , C _1-20 alkyl (meth)acrylates such as lauryl (meth)acrylate and stearyl (meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate; phenyl (meth)acrylate, etc. Aryl (meth)acrylates; Aralkyl (meth)acrylates such as benzyl (meth)acrylate and 2-phenylethyl (meth)acrylate; Hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. Examples include hydroxy C _1-4 alkyl (meth)acrylate. These (meth)acrylic monomers can be used alone or in combination of two or more. Among these, C _1-4 alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; hydroxyC _2-3 such as hydroxyethyl (meth)acrylate Alkyl (meth)acrylates are preferred.

Although the (meth)acrylic resin may be a homopolymer of these monomers, a copolymer is preferable. The copolymer may be a copolymer of two or more of the above (meth)acrylic monomers, and a copolymer of the above (meth)acrylic monomer and a copolymerizable monomer. It may be. Examples of copolymerizable monomers include styrene monomers such as styrene, α-methylstyrene, and vinyltoluene; α-C _2-20 olefins (ethylene, propylene, 1-butene, isobutylene, 1-hexene, (1-octene, 1-dodecene, etc.); and addition-polymerizable monomers such as carboxylic acid vinyl ester monomers such as vinyl acetate and vinyl butyrate. These copolymerizable monomers can be used alone or in combination of two or more. Among these, styrenic monomers such as styrene are preferred.

When the (meth)acrylic resin is a copolymer of a (meth)acrylic monomer and a styrene monomer (especially a copolymer of a methacrylic monomer and a styrene monomer), The molar ratio of the (meth)acrylic monomer to the styrene monomer is former/latter = 95/5 to 5/95, preferably 90/10 to 10/90, more preferably 80/20 to 20. /80, more preferably 70/30 to 30/70.

The (meth)acrylic polyol is not particularly limited as long as it is a (meth)acrylic polymer having two or more hydroxyl groups in the molecule. For example, hydroxy C _2- as a monomer of the (meth)acrylic resin It may also be a (meth)acrylic resin containing _3- alkyl (meth)acrylate.

Examples of modified (meth)acrylic resins include polyester modified (meth)acrylic resins such as polyester (meth)acrylate, polyurethane modified (meth)acrylic resins such as urethane (meth)acrylate, and epoxy (meth)acrylate. Examples include epoxy-modified (meth)acrylic resins such as epoxy-modified (meth)acrylic resins, and silicone-modified (meth)acrylic resins such as silicone (meth)acrylate. These modified (meth)acrylic resins can be used alone or in combination of two or more.

These (meth)acrylic resins can be used alone or in combination of two or more. Among these, (meth)acrylic resins having hydroxyl groups (especially isocyanate (meth)acrylic resins having a plurality of hydroxyl groups such as curable (meth)acrylic resins are preferred, and (meth)acrylic resins having hydroxyl groups and styrene units (for example, hydroxyalkyl (meth)acrylate-methyl (meth)acrylic resins) are preferred. ) acrylate-hydroxyalkyl (meth)acrylate-styrene copolymer, etc.) are particularly preferred. Note that the position of the hydroxyl group is not particularly limited, and it may be located on the main chain, on the side chain, or on the main chain and the side chain.

The hydroxyl value of the (meth)acrylic resin is, for example, 1 mgKOH/g or more (for example, 2 to 400 mgKOH/g), preferably 3 mgKOH/g or more (for example, 4 to 300 mgKOH/g), more preferably 5 mgKOH/g or more (for example, 6 ~200 mgKOH/g), more preferably 7 mgKOH/g or more (for example, 8 to 150 mgKOH/g), and usually 10 to 150 mgKOH/g (especially 50 to 100 mgKOH/g).

When the second resin (b4) described below is (meth)acrylic, the hydroxyl value of the (meth)acrylic resin of the first resin (b2) may be 15 mgKOH/g or more, for example, 15 to 400 mgKOH. /g, preferably 30 to 300 mgKOH/g, more preferably 50 to 200 mgKOH/g, more preferably 70 to 150 mgKOH/g, and most preferably 80 to 100 mgKOH/g.

The weight average molecular weight of the (meth)acrylic resin, when measured by gel permeation chromatography (GPC), is, for example, 1,000 to 100,000, preferably 2,000 to 80,000 (for example, 3, 000 to 50,000), more preferably 5,000 to 30,000 (for example, 10,000 to 20,000), and even more preferably 12,000 to 16,000.

The glass transition temperature of the (meth)acrylic resin is, for example, 0 to 120°C, preferably 40 to 110°C, more preferably 50 to 100°C, and most preferably 60 to 90°C. Note that in the present application, the glass transition temperature can be measured using a differential scanning calorimeter.

The (meth)acrylic resin may be a (meth)acrylic resin that does not have a carboxyl group or a salt thereof.

Polyvinyl acetal resin is obtained by reacting polyvinyl alcohol obtained by saponifying polyvinyl acetate with an aldehyde (particularly n-butyraldehyde) (acetalization reaction). In the acetalization reaction, polyvinyl alcohol cannot be completely acetalized (especially butyralized), so hydroxyl groups remain, and even during saponification, a small amount of acetyl groups remain, so polyvinyl acetal resins are , has an acetal group, a hydroxyl group, and an acetyl group in the structural unit.

That is, the polyvinyl acetal resin has, as constituent units, a vinyl acetal unit represented by the following formula (1), a vinyl alcohol unit represented by the following formula (2), and a vinyl ester represented by the following formula (3). Contains units.

(wherein R ¹ is a hydrogen atom or a hydrocarbon group).

In the formula (1), the hydrocarbon group represented by R ¹ includes an alkyl group, a cycloalkyl group, and an aryl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a hexyl group, a 2-ethylbutyl group, an octyl group, a 2-ethylhexyl group, and a nonyl group. Examples include linear or branched C _1-10 alkyl groups. Examples of the cycloalkyl group include C _5-10 cycloalkyl groups such as hexyl group. Examples of the aryl group include C _6-10 aryl groups such as phenyl group. As R, these hydrocarbon groups and hydrogen atoms can be used alone or in combination of two or more.

Among these, R ¹ is preferably a hydrogen atom or an alkyl group, more preferably a linear or branched C _1-5 alkyl group, more preferably a linear C _2-4 alkyl group, and a propyl group is more preferable. Most preferred. That is, as the polyvinyl acetal resin, polyvinyl formal resin and polyvinyl butyral resin (butyral resin) are preferable, and polyvinyl butyral resin is particularly preferable.

In addition to the structural units represented by formulas (1) to (3), the polyvinyl acetal resin may further contain other structural units. Other structural units may be units derived from copolymerizable monomers having radically polymerizable groups.

Examples of copolymerizable monomers include C _3-8 alkanoic acid-vinyl esters such as vinyl propionate, vinyl butyrate, vinyl pivalate, and vinyl caproate; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i- C _1-6 alkyl-vinyl ethers such as propyl vinyl ether and n-butyl vinyl ether; α-C _2-6 olefins such as ethylene, propylene, 1-butene, isobutene, and 1-hexene; (meth)acrylic acid and its salts; (meth)acrylic acid C _1-6 alkyl esters such as methyl meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate; (meth)acrylamide; unsaturated sulfones such as ethylenesulfonic acid and allylsulfonic acid Examples include acids. These copolymerizable monomers can be used alone or in combination of two or more.

Further, the polyvinyl acetal resin may be a polyvinyl acetal resin modified or modified by a conventional method.

The proportion of units represented by the formula (1) in the polyvinyl acetal resin (degree of acetalization) is about 5 to 95 mol% (for example, 10 to 90 mol%), and depending on the use, for example, 20 to 90 mol%. mol%, preferably 30 to 85 mol%, and 50 mol% or more (for example, 50 to 90 mol%), preferably 60 mol% or more (for example, 60 to 85 mol%), more preferably 70 mol% % or more (for example, 70 to 80 mol %). Further, the degree of acetalization may be, for example, 9 to 98% by mass, preferably 25 to 95% by mass, more preferably 35 to 90% by mass, and 55% by mass or more (for example, 55 to 95% by mass), preferably is 65% by mass or more (for example, 65 to 90% by mass), more preferably 70% by mass or more (for example, 70 to 80% by mass). If the degree of acetalization is too small, there is a risk that the silver luster will be reduced, and if the degree of acetalization is too high, there is a risk that it will be difficult to prepare a polyvinyl acetal resin.

The proportion of the unit represented by the formula (2) (unit having a hydroxyl group) in the polyvinyl acetal resin may be 10 to 50 mol% (for example, 15 to 40 mol%), preferably 20 to 35 mol%. %, more preferably 23 to 27 mol%. Further, the proportion of the units represented by formula (2) in the polyvinyl acetal resin may be 5 to 40% by mass (for example, 12 to 30% by mass), preferably 15 to 25% by mass, and more preferably is 18 to 23% by mass. If the proportion of the units represented by formula (2) is too small, there is a risk that the silver luster will decrease when polyvinyl acetal resin is used alone as a resin component, and conversely, if the proportion is too large, the same will happen. The polyvinyl acetal resin preferably contains a unit having a hydroxyl group because it has a high affinity for silver-containing metal nanoparticles (particularly composite nanoparticles) and is easily hardened with a hardening agent depending on the application.

The proportion of the unit represented by the formula (3) (unit having an acetyl group) in the polyvinyl acetal resin is, for example, 15 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less. Further, the proportion of the units represented by the formula (3) in the polyvinyl acetal resin is, for example, 20% by mass or less, preferably 10% by mass or less, and more preferably 5% by mass or less. If the proportion of the units represented by formula (3) is too large, there is a risk that silver luster may be reduced.

The total proportion of the structural units represented by formulas (1) to (3) in the polyvinyl acetal resin is, for example, 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, and more Preferably it is 100 mol%.

The proportion derived from the copolymerizable monomer in the polyvinyl acetal resin is, for example, 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less.

In the present application, the degree of acetalization and the proportion of each unit of the polyvinyl acetal resin can be measured using a conventional method, such as a titration method, an IR method, or an NMR method. In the case of a butyral resin, it can be measured by a method based on JIS K 6728 "Polyvinyl butyral test method".

The weight average molecular weight of the polyvinyl acetal resin (especially butyral resin) is, for example, 5,000 to 100,000, preferably 7,000 to 70,000, more preferably 10,000 to 40,000, and more preferably 12,000 to 20,000. If the molecular weight is too small, there is a risk that the mechanical properties of the silver glossy film will deteriorate, and if the molecular weight is too high, there is a risk that the film formability will deteriorate.

In addition, in this application, the weight average molecular weight of polyvinyl acetal resin is calculated based on the molecular weight of standard polystyrene from a chromatogram measured by gel permeation chromatography (GPC) according to the method described in JIS K 0124-2011. This is the value.

The glass transition temperature of polyvinyl acetal resin (especially butyral resin) can be selected from a range of about 50 to 130°C, for example 60 to 125°C, preferably 70 to 120°C, more preferably 80 to 115°C, more preferably is 90-115°C. If the glass transition temperature is too low, there is a risk that the mechanical properties of the silver luster film will deteriorate, and if it is too high, there is a risk that film formability will deteriorate.

In this application, the glass transition temperature of the polyvinyl acetal resin can be measured using a differential scanning calorimeter (DSC).

The 10% by mass solution viscosity (solvent: toluene/ethanol (mass ratio) = 50/50) of polyvinyl acetal resin (especially butyral resin) is measured with a rotational viscosity type (BM type) at a temperature of 20 ° C. , 2 to 20,000 mPa・s (especially 10 to 10,000 mPa・s), and depending on the application, for example, 5 to 1,000 mPa・s (for example, 10 to 500 mPa・s), preferably 20 ~400 mPa·s (for example, 25 to 300 mPa·s), more preferably 50 to 250 mPa·s (for example, 70 to 200 mPa·s), and for example 3 to 150 mPa·s (for example, 5 to 100 mPa·s) , preferably 10 to 50 mPa·s (especially 10 to 30 mPa·s). If the viscosity is too low, there is a risk that the mechanical properties of the silver glossy film will deteriorate, and if the viscosity is too high, there is a possibility that the film formability will deteriorate.

Among these, (meth)acrylic resin is most preferred because of its excellent silver luster.

In the first phase, the proportion of the silver-containing metal is, for example, 20 to 20,000 parts by mass, preferably 50 to 10,000 parts by mass, more preferably 100 to 5 parts by mass, based on 100 parts by mass of the first resin (b2). ,000 parts by mass. If the proportion of the silver-containing metal is too small, there is a risk that the shielding properties will be reduced, and if it is too large, there is a possibility that the adhesion and scratch resistance will be reduced.

(Phase 2)
In the second phase, the composite nanoparticles (b3) are the same as the composite nanoparticles (a) described in the section of the interface layer (A), including preferred embodiments, and are usually Same as nanoparticle (a).

The second resin (b4) is not particularly limited, and examples thereof include the resins exemplified as the first resin (b2) of the first phase. Among the resins, resins having a lower affinity for composite nanoparticles of silver-containing metal and protective colloid than the first resin (b2) are preferred, and (meth)acrylic resins and silicone resins are particularly preferred.

Examples of the (meth)acrylic resin include the resins exemplified as the (meth)acrylic resin of the first resin (b2).

When the first resin (b2) is a (meth)acrylic resin, the (meth)acrylic resin of the second resin (b4) has a lower hydroxyl group than the (meth)acrylic resin of the first resin (b2). It is preferable that it has a value.

The hydroxyl value of the (meth)acrylic resin of the second resin (b4) may be 70 mgKOH/g or less, for example 1 to 50 mgKOH/g, preferably 2 to 30 mgKOH/g, more preferably 3 to 20 mgKOH/g. g, more preferably 5 to 15 mgKOH/g, most preferably 8 to 12 mgKOH/g.

The silicone resin is not particularly limited, and may be a silicone resin or a silicone oligomer. Among these, silicone resins are preferred because they can improve adhesion and scratch resistance.

The silicone resin may be a thermoplastic resin, a curable resin (uncrosslinked resin), or a cured resin (crosslinked resin) having a polyorganosiloxane skeleton. The polyorganosiloxane skeleton is a linear, branched or network compound having Si-O bonds (siloxane bonds), and has the formula: R ² _a SiO _(4-a)/2 (in the formula, R ² represents a substituent, and the coefficient a is a number from 0 to 3). Silicone resins include monofunctional M units (generally represented by R 2 3 SiO 1/2), which are each unit represented by the above formula, and difunctional D units (generally represented by R ² ₃ SiO _1/2 ). unit represented by R ² ₂ SiO _2/2 ), trifunctional T unit (generally represented by R ² SiO _3/2 ), tetrafunctional Q unit (generally represented by SiO _4/ Among the units represented by ₂ ), polyorganosiloxanes containing T units as main units are usually used.

In the above formula, the substituent R ² is, for example, a C _1-10 alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, etc. Halogenated C _1-10 alkyl group, C _2-10 alkenyl group such as vinyl group, allyl group, butenyl group, C _6-20 aryl group such as phenyl group, tolyl group, naphthyl group, cyclopentyl group, cyclohexyl group, etc. Examples include C _3-10 cycloalkyl groups, C _6-12 aryl-C _1-4 alkyl groups such as benzyl groups, and phenethyl groups. These substituents can be used alone or in combination of two or more.

Among these, R ² is preferably a C _1-4 alkyl group such as a methyl group or a propyl group, a C _6-10 aryl group such as a phenyl group or a naphthyl group, a C _1-3 alkyl group, or a C _6-8 alkyl group. An aryl group is more preferred, and a methyl group and a phenyl group are most preferred. Furthermore, as for R ² , it is preferable to use two or more types in combination rather than using it alone from the viewpoint of improving compatibility with the ( _meth )acrylic resin _{. A -10} aryl group is more preferred, a combination of a C _1-3 alkyl group and a C _6-8 aryl group is more preferred, and a combination of a methyl group and a phenyl group is most preferred.

When combining a C _1-4 alkyl group and a C _6-10 aryl group, the molar ratio of the two is selected from a range of approximately C _1-4 alkyl group/C _6-10 aryl group = 30/1 to 1/30. For example, 20/1 to 1/10, preferably 10/1 to 1/5, more preferably 8/1 to 1/1, more preferably 5/1 to 1.5/1, most preferably 3/1. It is 1 to 2/1.

The silicone resin may be a straight silicone resin (unmodified silicone resin) or a modified silicone resin. Examples of the modified silicone resin include silicone resins modified with other resins such as alkyd resins, phenol resins, urea resins, melamine resins, and epoxy resins.

Specifically preferred silicone resins include C _1-4 alkyl silicone resins in which the substituent R ² is a C _1-4 alkyl group such as a methyl group (for example, C _1-3 alkyl resins such as methyl silicone resins). silicone resin, etc.), C _6-10 aryl silicone resin in which substituent R ² is a C _6-10 aryl group such as phenyl group (for example, C _6-8 aryl silicone resin such as phenyl silicone resin), substituted C _1-4 alkyl C _6-10 aryl silicone resin in which the group R ² is a combination of a C _1-4 alkyl group and a C _6-10 aryl group (for example, methylphenyl silicone resin, propylphenyl silicone resin, etc.) C _1-3 alkyl C _6-8 aryl silicone resin, etc.). These silicone resins can be used alone or in combination of two or more. From the viewpoint of improving adhesion and scratch resistance, alkylaryl silicone resins such as C _1-4 alkyl C _6-10 aryl silicone resins are preferred, and C _1-2 alkyl C _6- such as methylphenyl silicone resins are preferred. Particularly preferred are _8- aryl silicone resins.

In the intermediate layer (B), the second resin (b4) has a lower affinity for composite nanoparticles of silver-containing metal and protective colloid than the first resin (b2); The content ratio of silver-containing metal (particularly silver-containing metal nanoparticles) is smaller than that of one phase.

In the second phase, the proportion of the silver-containing metal may be 10,000 parts by mass or less, for example 0 to 5,000 parts by mass, preferably 0 to 3 parts by mass, based on 100 parts by mass of the second resin (b4). ,000 parts by mass, more preferably 0 to 2,000 parts by mass. If the proportion of silver-containing metal is too high, there is a risk that adhesion and scratch resistance will decrease.

(Composition of intermediate layer (B))
The proportion of the first resin (b2) is, in terms of solid content, the silver-containing metal in the silver glossy film [i.e., the silver-containing metal contained in the composite nanoparticles (a), (b1), (b3), and (c)]. 100 parts by weight, for example, 1 to 50 parts by weight, preferably 3 to 40 parts by weight, more preferably 5 to 30 parts by weight, more preferably 10 to 25 parts by weight, most preferably is 15 to 20 parts by mass. If the proportion of the first resin (b2) is too small, there is a risk that the adhesion and scratch resistance will be reduced, and if it is too large, there is a possibility that the silver luster will be reduced.

The mass ratio of the first resin (b2) and the second resin (b4) can be selected from a range of about 97/3 to 3/97 (former/latter), for example, 95/5 to 5/95 in terms of solid content. , preferably 90/10 to 10/90 (for example 80/20 to 30/70), more preferably 75/25 to 40/60, more preferably 70/30 to 50/50 (especially 65/35 to 55/ 45). If the proportion of the first resin (b2) is too small, there is a risk that the silver luster and adhesion will deteriorate, and if the proportion is too large, the same may occur.

The total proportion of the first resin (b2) and the second resin (b4) can be selected from a range of about 1 to 500 parts by mass, for example 5 to 300 parts by mass ( For example, 10 to 250 parts by weight), preferably 5 to 200 parts by weight (for example, 10 to 200 parts by weight), more preferably 10 to 100 parts by weight (for example, 10 to 50 parts by weight), more preferably 20 to 50 parts by weight ( In particular, 25 to 35 parts by mass). If the total ratio is too small, there is a risk that the adhesion and scratch resistance will be reduced, and if it is too large, there is a risk that the silver luster will be reduced.

(b5) Curing agent In addition to the composite nanoparticles and resin, the intermediate layer may further contain a curing agent (b5). Examples of the curing agent (b5) include conventional curing agents such as isocyanate curing agents, amine curing agents, acid anhydride curing agents, and imidazole curing agents. Among these, isocyanate-based curing agents are preferred, and polyisocyanates are particularly preferred. Isocyanate curing agents such as polyisocyanate are particularly effective when the (meth)acrylic resin has a functional group (particularly a hydroxyl group).

Examples of the polyisocyanate include aliphatic polyisocyanates [diisocyanates such as propylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMDI), and lysine diisocyanate (LDI); , 11-undecane triisocyanate methyl octane, 1,3,6-hexamethylene triisocyanate and other tri- or polyisocyanates], alicyclic polyisocyanates [cyclohexane 1,4-diisocyanate, isophorone diisocyanate (IPDI), hydrogenated xylylene di isocyanates, diisocyanates such as hydrogenated bis(isocyanatophenyl)methane; tri- or polyisocyanates such as bicycloheptane triisocyanate], aromatic polyisocyanates [phenylene diisocyanate, tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), Diisocyanates such as tetramethylxylylene diisocyanate (TMXDI), naphthalene diisocyanate (NDI), bis(isocyanatophenyl)methane (MDI), toridine diisocyanate (TODI), 1,3-bis(isocyanatophenyl)propane; isocyanate] and the like.

Polyisocyanates include derivatives such as multimers (dimers, trimers, tetramers, etc.), adducts, modified products (biuret modified products, allophanate modified products, urea modified products, etc.), and derivatives containing multiple isocyanate groups. It may also be a urethane oligomer having Modified products or derivatives of polyisocyanates include, for example, adducts of polyisocyanates (aliphatic polyisocyanates such as hexamethylene diisocyanate, etc.) and polyhydric alcohols (trimethylolpropane, pentaerythritol, etc.), and biuret products of the polyisocyanates. , a multimer of the polyisocyanate (for example, aliphatic polyisocyanate) (for example, a polyisocyanate having an isocyanurate ring such as a trimer of hexamethylene diisocyanate), and the like.

These polyisocyanates can be used alone or in combination of two or more. Among these polyisocyanates, aliphatic polyisocyanates or derivatives thereof (eg, HDI or its trimer, etc.), aromatic polyisocyanates (TDI, MDI, etc.), and the like are commonly used.

The proportion of the curing agent (b5) is, for example, 10 to 200 parts by weight, preferably 20 to 150 parts by weight, and more preferably 25 to 100 parts by weight, based on 100 parts by weight of the first resin (b2).

(b6) Other metal nanoparticles In addition to the composite nanoparticles and resin, the intermediate layer (B) may further contain other metal nanoparticles (b6). Examples of other metal nanoparticles (b6) include metals from group 8 of the periodic table (iron, nickel, cobalt, ruthenium, rhodium, palladium, rhenium, iridium, platinum, etc.), metals from group 1B of the periodic table (copper, gold, etc.). ), Group 3B metals of the periodic table (aluminum, gallium, indium, etc.), metals of Group 4B of the periodic table (germanium, tin, lead, etc.), and the like. Note that the metal (metal atom) is often a metal that has a high degree of coordination with the protective colloid, such as a metal from group 8 of the periodic table or a metal from group 1B of the periodic table. The proportion of the other metal particles (b6) is 100 parts by mass or less, preferably 50 parts by mass or less, and more preferably 10 parts by mass or less, based on 100 parts by mass of the silver-containing metal of the silver luster film.

(b7) Other components The intermediate layer (B) contains conventional additives as other components (b7), such as plasticizers (or film-forming aids), gloss imparting agents, to the extent that the effects of the present invention are not impaired. agents, metal corrosion inhibitors (rust inhibitors), stabilizers (antioxidants, ultraviolet absorbers, light stabilizers, etc.), surfactants (anionic surfactants, cationic surfactants, nonionic surfactants) , amphoteric surfactants, in particular anionic and/or nonionic surfactants), dispersion stabilizers, thickeners or viscosity modifiers, humectants, thixotropic agents, leveling agents, penetrants, Contains antifoaming agents, pH adjusting agents, chelating agents, surface tension adjusting agents, coloring agents (dyes and pigments, etc.), hue improvers, dye fixing agents, bactericidal agents, antifungal agents, preservatives, oxygen absorbers, etc. Good too. Note that the surfactant may be an acetylene glycol surfactant, a polysiloxane surfactant, a fluorine surfactant, or the like. These additives can be used alone or in combination of two or more. The proportion of the other component (b7) is 50 parts by mass or less, preferably 30 parts by mass or less, and more preferably 10 parts by mass or less, based on 100 parts by mass of the silver-containing metal of the silver luster film.

(Structure of middle layer (B))
The intermediate layer (B) may have a phase-separated structure in which the first phase and the second phase have a smaller content of silver-containing metal than the first phase.

The ratio of the first phase to the second phase (area ratio in the cross section) can be selected from the range of first phase/second phase = 97/3 to 10/90, for example, 95/5 to 20/80, preferably is 90/10 to 30/70, more preferably 80/20 to 40/60, more preferably 70/30 to 50/50, most preferably 65/35 to 55/45. If the proportion of the first phase is too small, there is a risk that the silver luster and adhesion will deteriorate, and if the proportion is too large, the same may occur.

In addition, in this application, the said ratio can be measured based on the transmission electron microscope (TEM) image of the cross section of a silver luster film, and can be measured in detail by the method described in the Example mentioned later.

The phase separation structure may be a sea-island structure or a co-continuous structure. Among these, the sea-island structure is preferred.

When the intermediate layer (B) has a sea-island structure, the continuous phase (matrix phase) constituting the sea portion may be the first phase or the second phase. Among these, it is preferable that the second phase is a continuous phase. By forming a continuous phase with the second phase containing a small proportion of silver-containing metal, the composite nanoparticles (b1) can be aggregated in the dispersed phase to improve the shielding property.

In the sea-island structure, the average diameter of the dispersed phase is, for example, 5 to 3,000 nm, preferably 10 to 1,000 nm, more preferably 100 to 800 nm, more preferably 300 to 600 nm, most preferably 400 to 500 nm. If the average diameter of the dispersed phase is too small, there is a risk that the shielding properties will be reduced, and if it is too large, there is a risk that the adhesiveness and scratch resistance will be reduced. In the present application, when the shape of the dispersed phase is anisotropic, the average value of the major axis and the minor axis is defined as the diameter of each dispersed phase.

The average pitch of the dispersed phases (the average value of the distance between the centers of adjacent dispersed phases) is, for example, 5 to 2,500 nm, preferably 10 to 2,000 nm, more preferably 100 to 1,500 nm, and more preferably 300 to 2,000 nm. 1,000 nm, most preferably 500-700 nm. If the average pitch of the dispersed phase is too small, there is a risk that the adhesion and abrasion resistance will be reduced, and if it is too large, there is a risk that the shielding performance will be reduced.

The method for observing the cross section of the silver glossy film is not particularly limited, and any method used for ordinary structural analysis can be used. Observation methods include morphology and structure observation using transmission electron microscopes (TEM), scanning electron microscopes (SEM), electron beam microanalyzers (EPMA), scanning probe microscopes (SPM), etc.; fluorescent X-rays and energy dispersive Constituent elements can be analyzed by X-ray spectroscopy (EDX), wavelength dispersive X-ray spectroscopy (WDX), electron energy-loss spectroscopy (EELS), or the like. Among these, transmission electron microscopy (TEM) observation is particularly preferred since it allows observation of even the fine structure. A sample to be subjected to observation can be appropriately processed and used to make it suitable for observation and analysis. For example, a thin section sample may be prepared using a microtome or the like.

Therefore, in this application, the structure, size, and distribution state of the island structure in the cross section of the silver glossy film can be observed and measured based on the TEM image of the cross section of the silver gloss film, and the size is the average value of arbitrary 10 locations. . In detail, it can be measured by the method described in Examples below. Furthermore, in the TEM image, the silver-containing metal nanoparticles are dark-colored and can be easily confirmed, and in the intermediate layer, the aggregated portions of the silver-containing metal nanoparticles serve as the dispersed phase.

The average thickness of the intermediate layer (B) is, for example, 0.05 to 100 μm, preferably 0.1 to 30 μm, more preferably 0.5 to 20 μm, more preferably 1 to 10 μm, and most preferably 5 to 7 μm. If the average thickness of the intermediate layer (B) is too thin, there is a risk that the light shielding property will be reduced, and the adhesion and scratch resistance will be reduced, and if it is too thick, there is a risk that the silver luster will be reduced.

The average thickness of the intermediate layer (B) may be twice or more (for example, 3 to 1,000 times) the average thickness of the surface layer (C), for example, 5 to 500 times, preferably 10 to 300 times. times, more preferably 25 to 250 times, more preferably 25 to 100 times, and most preferably 30 to 50 times. If the thickness ratio of the intermediate layer (B) is too small, there is a risk that the adhesion and scratch resistance will be reduced, and if it is too large, there is a risk that the silver luster will be reduced.

In addition, in this application, the average thickness of the intermediate layer (B) can be measured by observing the cross section of the silver glossy film with a transmission electron microscope (TEM), and is the average value of three arbitrary locations.

(C) Surface layer The surface layer (C) is formed of composite nanoparticles (c) of a metal containing silver and a protective colloid, and the composite nanoparticles (c) are formed on the surface of the silver glossy film. By being arranged or oriented, the silver-containing metal forms a dense thin film (silver thin film). In the present invention, silver luster can be improved by forming such a surface layer (C) on the surface of the silver luster film.

The composite nanoparticles (c) are the same as the composite nanoparticles (a) described in the section of the interface layer (A), including preferred embodiments, and are usually the same as the composite nanoparticles (a). is the same as

The average thickness of the surface layer (C) is, for example, 3 to 300 nm (for example, 10 to 250 nm), preferably 5 to 200 nm, more preferably 10 to 100 nm, more preferably 15 to 50 nm, most preferably 20 to 40 nm. If the average thickness of the surface layer (C) is too thin, there is a possibility that the silver luster will be reduced, and if it is too thick, there is a possibility that the scratch resistance will be reduced.

In addition, in this application, the average thickness of the surface layer (C) can be measured by observing the cross section of the silver glossy film with a transmission electron microscope (TEM), and in detail, it can be measured by the method described in the Examples below. .

[Method for manufacturing silver gloss film]
The silver luster film of the present invention is produced by applying a liquid composition containing composite nanoparticles of a silver-containing metal and a protective colloid, a first resin, a second resin, and a solvent onto an object to be decorated (substrate). step, the coating film formed from the liquid composition is dried and phase separated by spinodal decomposition to obtain a silver glossy film.

(Coating process)
In the coating process, the type of base material is not particularly limited, and resin substrates, metal substrates, glass substrates, ceramic substrates, paper, etc. can be used depending on the purpose.

The liquid composition can be prepared by mixing the composite nanoparticles, the first resin, the second resin, and the solvent in a conventional manner. As a mixing method, a conventional stirring device may be used, for example, a stirring defoaming device may be used. By adding a solvent to the liquid composition, phase separation due to spinodal decomposition can be promoted, and film-forming properties can also be improved.

Preferably, the solvent comprises a polar organic solvent. Examples of polar organic solvents include alcohols (C _1-4 alkanols such as methanol, ethanol, propanol, and isopropanol, 3-methoxy-3-methyl-1-butanol, etc.), polyhydric alcohols (ethylene glycol, propylene glycol, etc.), and polyhydric alcohols (ethylene glycol, propylene glycol, etc.). alkanediols such as glycerin, alkanetriols such as trimethylolpropane, alkanetetraols such as pentaerythritol), amides (acylamides such as formamide and acetamide, N-methylformamide, N-methylacetamide, N,N- dimethylformamide, mono- or di-C _1-4 acylamides such as N,N-dimethylacetamide, etc.), pyrrolidones (2-pyrrolidone, 3-pyrrolidone, N-methyl-2-pyrrolidone, N-methyl-3-pyrrolidone, etc.) ), ketones (acetone, diacetone alcohol, methyl ethyl ketone, isophorone, etc.), ethers (dioxane, tetrahydrofuran, etc.), organic carboxylic acids (acetic acid, etc.), esters (methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, acetic acid) acetate esters such as amyl), alkylene glycol monoalkyl ethers (methyl cellosolve, ethyl cellosolve, propylene glycol methyl ether, C _2-6 alkylene glycol mono C _1-4 alkyl such as 3-methoxy-3-methyl-1-butanol) ethers, etc.), dialkylene glycol monoalkyl ethers (di-C _2-6 alkylene glycol mono-C _1-4 alkyl ethers such as methyl carbitol, ethyl carbitol, propyl carbitol, butyl carbitol, etc.), cellosolve acetates (ethyl Examples include C _1-4 alkyl cellosolve acetates such as cellosolve acetate), carbitol acetates (C _1-4 alkyl carbitol acetates such as methyl carbitol acetate and butyl carbitol acetate), and dimethyl sulfoxide. These polar organic solvents can be used alone or in combination of two or more.

The proportion of the polar organic solvent in the solvent may be 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass. Good too.

In addition to the polar solvent, the solvent may further include a non-polar solvent. Examples of the nonpolar solvent include aliphatic hydrocarbons such as hexane, octane, and decane, and alicyclic hydrocarbons such as cyclohexane and tetralin. The proportion of the nonpolar organic solvent may be 50 parts by mass or less (for example, about 0.1 to 50 parts by mass), preferably 30 parts by mass or less, and more preferably 10 parts by mass based on 100 parts by mass of the polar organic solvent. below.

Among these solvents, it is preferable that the solvent contains one or more selected from alcohols, esters, alkylene glycol monoalkyl ethers, and dialkylene glycol monoalkyl ethers, and includes aliphatic carboxylic acid C _1-6 alkyl esters, alkylene glycols, etc. It is more preferable to contain one or more selected from monoalkyl ethers and dialkylene glycol monoalkyl ethers. Among these, the solvent is preferably a combination of an alkylene glycol monoalkyl ether and a dialkylene glycol monoalkyl ether, and a combination of a C _2-6 alkylene glycol mono-C _1-3 alkyl ether and a di-C _2-6 alkylene glycol mono-C _1-3 A combination with an alkyl ether is more preferred, and a combination of a C _4-6 alkylene glycol mono-C _1-2 alkyl ether and a di-C _2-4 alkylene glycol mono-C _1-2 alkyl ether is most preferred.

When the solvent is a combination of an alkylene glycol monoalkyl ether and a dialkylene glycol monoalkyl ether, the composite nanoparticles are in the form of a dispersion in the dialkylene glycol monoalkyl ether, the first resin and the second resin. May be mixed with resin and alkylene glycol monoalkyl ether.

When the solvent is a combination of alkylene glycol monoalkyl ether and dialkylene glycol monoalkyl ether, the proportion of dialkylene glycol monoalkyl ether may be 100 parts by mass or less based on 100 parts by mass of alkylene glycol monoalkyl ether. Often, for example, 0.01 to 50 parts by weight, preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, most preferably 2 to 10 parts by weight. be. If the proportion of dialkylene glycol monoalkyl ether is too high, the effect of promoting a phase-separated structure may be reduced. The dialkylene glycol monoalkyl ether may be a polar solvent derived from a dispersion medium for dispersing composite nanoparticles as a raw material.

The proportion of the solvent is, for example, 50 to 500 parts by weight, preferably 80 to 400 parts by weight, more preferably 100 to 300 parts by weight, and more preferably 120 to 300 parts by weight, based on 100 parts by weight of the silver-containing metal of the composite nanoparticles. 250 parts by weight, most preferably 150-200 parts by weight. If the proportion of the solvent is too small, it will be difficult to form a phase-separated structure and there is a risk that film-forming properties will be reduced, and if it is too large, there is a possibility that productivity and film-forming properties will be reduced.

The application method is not particularly limited and may include any conventional coating method, such as flow coating method, dispenser coating method, spin coating method, spray coating method, screen printing method, flexographic printing method, casting method, bar coating method, curtain coating method. method, roll coating method, gravure coating method, dipping method, slit method, photolithography method, inkjet method, offset printing method, etc. can be used.

The average thickness (dry thickness) of the coating film is, for example, 0.05 to 100 μm, preferably 0.1 to 30 μm, more preferably 0.5 to 10 μm, and even more preferably 1 to 5 μm.

In addition, in the present invention, it is possible to achieve both silver luster, adhesion, and scratch resistance without forming an undercoat layer or a topcoat layer, but depending on the application, an undercoat layer and/or a topcoat layer may also be used in combination. good.

(Phase separation process)
In the phase separation step, by drying the coating film, as the solvent evaporates, spinodal decomposition causes phase separation into a first phase containing a large amount of silver-containing metal and a second phase containing a small amount of silver-containing metal. .

As a method for drying the coating film, a method of heating and drying is preferable, and a method of heating and drying in two stages combining a preliminary heat treatment and a main heat treatment is preferable since it is easy to form a phase-separated structure. .

In the preheating treatment, the preheating temperature is, for example, 40 to 80°C, preferably 45 to 70°C, more preferably 45 to 60°C, and more preferably 45 to 55°C. The preheating time is, for example, 1 to 100 minutes, preferably 3 to 60 minutes, and more preferably 5 to 30 minutes.

In the main heat treatment, the main heating temperature is, for example, 60 to 150°C, preferably 65 to 120°C, more preferably 70 to 90°C, and more preferably 75 to 85°C. The main heating time is, for example, 30 to 240 minutes, preferably 80 to 180 minutes, and more preferably 100 to 150 minutes.

The present invention will be explained in more detail below based on Examples, but the present invention is not limited by these Examples. In the following examples, the preparation method of the ink composition and the measurement method of the evaluation test are shown below.

[Materials used]
Acrylic resin A: “ARUFON UH2170” manufactured by Toagosei Co., Ltd., styrene acrylic resin, non-volatile content 98% or more, hydroxyl value 88 mgKOH/g, glass transition temperature 60°C
Acrylic resin B: “WXU-880” manufactured by DIC Corporation, isocyanate-curing acrylic resin, non-volatile content 50%, hydroxyl value 10 mgKOH/g, glass transition temperature 90°C
Acrylic resin C: “ZU-582” manufactured by DIC Corporation, isocyanate-curing acrylic resin, non-volatile content 50%, hydroxyl value 46 mgKOH/g
Polyvinyl butyral resin: "S-LEC KS-10" manufactured by Sekisui Chemical Co., Ltd., degree of acetalization 70 mol% or more, acetyl group 3 mol% or less, hydroxyl group 25 mol%, 10% by mass Solution viscosity (temperature 20 ° C., rotational viscosity Type (BM type), solvent = toluene/ethanol = 50/50 (mass ratio)) 10 to 30 mPa・s, glass transition temperature 106°C, weight average molecular weight 17,000
Silicone resin A: "KR211" manufactured by Shin-Etsu Chemical Co., Ltd., methylphenyl silicone resin Silicone resin B: "RSN6018" manufactured by DOW Toray Industries, Inc., propylphenyl silicone resin Curing agent: "Burnock DN902S" manufactured by DIC Corporation ”, isocyanate compounds.

[Glossiness]
The 20° glossiness was measured using an appearance analyzer ("Rhopoint IQ-S" manufactured by Konica Minolta Japan, Inc.) and ranked (A, B, C) according to the following criteria. Note that when the glossiness value is 400 or more, metallic luster (mirror surface) can be visually confirmed, so ranks A and B were determined to be acceptable.

Rank A: Gloss level is 600 or higher (passed)
Rank B: Glossiness is 400 or more and less than 600 (pass)
Rank C: Glossiness is less than 400 (fail).

[Light opacity]
Visible light transmittance in the wavelength range of 380 to 780 nm was measured using an ultraviolet-visible near-infrared spectrophotometer ("UV-3100PC" manufactured by Shimadzu Corporation) and an integrating sphere ISR-3100. The integral value of the transmittance with respect to the integral value of the blank measurement (atmosphere) was determined by integrating the transmittance in the wavelength range of 380 to 780 nm, and evaluated according to the following criteria. The smaller the integral value of the transmittance for the blank measurement, the lower the permeability of the membrane, which is better.

○: Integral value of transmittance is 1.0% or less (pass)
△: Integral value of transmittance is greater than 1.0% and less than 5.0% (pass)
x: The integral value of transmittance is larger than 5.0% (fail).

[Adhesion]
Cellotape (registered trademark) was applied to the cured film, peeled off vigorously, and evaluated based on the following criteria.

○: No peeling in the film (passed)
×: There is peeling in the film (fail).

[Abrasion resistance]
The cured film was subjected to a friction test using a friction and abrasion tester with dry cotton under a load of 500 g and 10 reciprocations. The 20° glossiness of the cured film after the friction test was measured, the rate of decrease in glossiness before and after the friction test was determined, and the scratch resistance was evaluated according to the following criteria.

〇: Decrease rate of glossiness is less than 20% (pass)
△: Decrease rate of glossiness is 20% or more and less than 50% (pass)
×: Decrease rate of glossiness is 50% or more (fail).

[Comprehensive judgment]
Judgments were made based on the results of glossiness, light opacity, adhesion, and abrasion resistance, and grades A and B were considered acceptable.

A rating: Glossiness is rank A, light opacity, adhesion, and scratch resistance pass B rating: Glossiness is rank B, light opacity, adhesion, and scratch resistance pass C rating: Glossiness is rank B Rank C, or failure in any one of light opacity, adhesion, and scratch resistance.

[Cross-sectional observation of membrane]
A sample was cut out from the obtained shiny silver film, embedded in an epoxy resin which is a general-purpose embedding resin, and the cut cross section was exposed using a microtome and subjected to SEM observation. Furthermore, in order to observe the fine structure, after exposing the cut cross section with a microtome, we prepared ultrathin sections with a thickness of about 100 nm or less, performed TEM observation, and determined the size of the dispersed phase (average diameter and average pitch).

(Average thickness of surface layer and interface layer)
The thickness of the layer in which the silver nanoparticles were arranged was measured in the TEM enlarged image near the surface and near the interface. The average value of the layer thicknesses measured at three arbitrary locations was defined as the average thickness.

(Average diameter of dispersed phase)
The long axis and short axis of the dispersed phase (island) in which silver nanoparticles were aggregated were measured, and the average value was taken as the diameter of the dispersed phase (island). Then, the average value of the diameters calculated for ten arbitrary dispersed phases (islands) was taken as the average diameter of the dispersed phase.

(Average pitch of dispersed phase)
The intersection between the long axis and the short axis of the dispersed phase was set as the center of the dispersed phase, and the distance between the centers of adjacent dispersed phases was measured. The average value of the distances between the centers measured at arbitrary 10 locations was defined as the average pitch of the dispersed phase.

(Ratio of 1st phase and 2nd phase)
The first phase and second phase of the cross-sectional TEM image were binarized using image processing software "ImageJ" (available from https://imagej.Nih.gov/ij/). The areas of the first phase and the second phase were determined from the binarized image processed image, and the ratio between the first phase and the second phase was calculated. In this example, the ratio was calculated without excluding the surface layer and the interface layer, so the ratio of the first phase also includes the areas of the surface layer and the interface layer.

Examples 1 to 8 and Comparative Examples 1 to 2
(Method for preparing silver nanoparticle dispersion)
66.8 g of silver nitrate, a polymer dispersant having a carboxyl group ("Disperbic 190" manufactured by BIC Chemie), a solution of a high molecular weight block copolymer having a pigment affinity group, solvent: water, non-volatile components 40%, acid value 10 mg KOH /g, amine value 0) was added to 100 g of ion-exchanged water and vigorously stirred to obtain a suspension. To this suspension, 100 g of dimethylaminoethanol (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was gradually added so that the water temperature did not exceed 50°C, and then placed in a water bath at a water temperature of 50°C for 4 hours. The mixture was heated and stirred.

An excess amount of methanol was added to the silver nanoparticle dispersion and stirred, and then the silver nanoparticles were precipitated by centrifugation, and the supernatant liquid was removed. Methanol was added and stirred again, and then the silver nanoparticles were precipitated by centrifugation, and the supernatant liquid was removed. Diethylene glycol monobutyl ether was added to the methanol solution containing the obtained precipitate, and the mixed methanol was removed using an evaporator to obtain a silver nanoparticle dispersion having a silver content of 70% by mass. Regarding this dispersion, when the particle size of the silver nanoparticles was confirmed using a transmission electron microscope (manufactured by JEOL Ltd.), the number average particle size of the primary particles was about 20 nm.

(Method for preparing metallic ink composition)
The obtained silver nanoparticle dispersion, resin, and solvent were stirred and mixed in the proportions shown in Table 1 using a stirring defoaming device ("Mazel Star" manufactured by Kurabo Industries, Ltd.) to prepare a metallic ink composition. Note that the amount of acrylic resin in the table is the content in terms of solid content. The metallic ink composition was applied to a glass substrate using a 20 μm applicator. Thereafter, it was heated on a 50°C hot plate for 10 minutes, and then heated on an 80°C hot plate for 120 minutes.

Table 1 shows the evaluation results of the obtained silver gloss film.

As is clear from the results in Table 1, the silver luster film of the example was able to achieve both silver luster and light non-transparency, as well as adhesion and scratch resistance, whereas the silver luster film of the comparative example , silver luster and light transmittance were low.

Specifically, the silver luster films of Examples 1 to 5 and 8 were able to achieve both silver luster and light non-transmission, as well as adhesion and scratch resistance. In addition, the silver gloss films of Examples 6 and 7 were able to achieve both silver gloss and light non-transmittance, as well as adhesion and scratch resistance at a practical level.

Cross-sectional photographs of the silver luster films obtained in Examples 1 to 4 are shown in FIGS. 1 to 16. In the silver glossy films of Examples 1 to 4, as is clear from FIGS. 1, 5, 9, and 13 showing the overall image and FIGS. 4, 8, 12, and 16 showing enlarged images of the inside of the film, there was no silver There was phase separation into a region where nanoparticles (dark colored particles in the photo) aggregated (dispersed phase) and a region where silver nanoparticles were less aggregated (continuous phase). That is, as is clear from the overall image and the enlarged image of the inside of the membrane, there is phase separation inside the membrane into a region where silver nanoparticles aggregate (first phase) and a region where silver nanoparticles are less agglomerated (second phase). It had a phase-separated structure (silver nanoparticles had a structure in which they were unevenly distributed in the dispersed phase). The phase separation structure was a sea-island structure, in which the first phase in which silver nanoparticles aggregated formed a dispersed phase, and the second phase in which silver nanoparticles aggregated less formed a continuous phase. Furthermore, as is clear from FIGS. 2, 6, 10, and 14, which are enlarged images of the vicinity of the surface, and FIGS. 3, 7, 11, and 15, which are enlarged images of the vicinity of the interface with the base material, the surface and the interface with the base material In this case, silver nanoparticles were aligned to form a thin continuous layer (thin layer). The average thickness of the continuous layer ranged from 19 to 171 nm. The minimum average thickness of the intermediate layer was 27 times that of the surface layer.

Cross-sectional photographs of the silver luster films obtained in Examples 5 to 8 are shown in FIGS. 17 to 32. In the silver glossy films of Examples 5 to 8, as is clear from FIGS. 17, 21, 25 and 29 showing the overall image and FIGS. 20, 24, 28 and 32 showing enlarged images of the inside of the film, there was no silver There was phase separation into a region where nanoparticles (dark particles in the photo) aggregated (continuous phase) and a region where silver nanoparticles were less aggregated (dispersed phase). Furthermore, as is clear from FIGS. 18, 22, 26, and 30, which are enlarged images of the vicinity of the surface, and FIGS. 19, 23, 27, and 31, which are enlarged images of the vicinity of the interface with the base material, the surface and the interface with the base material In this case, silver nanoparticles were aligned to form a thin continuous layer (thin layer). In other words, the inside of the membrane has a phase separation structure with a sea-island structure, in which the first phase in which silver nanoparticles aggregate forms a continuous phase, and the second phase in which silver nanoparticles aggregate less forms a dispersed phase. was. The maximum average thickness of the intermediate layer was 200 times that of the surface layer.

The silver luster films of Comparative Examples 1 and 2 had lower silver luster and light opacity than the silver luster films of Examples.

Cross-sectional photographs of the silver luster films obtained in Comparative Examples 1 and 2 are shown in FIGS. 33 to 40. As is clear from FIGS. 33 to 40, in Comparative Examples 1 and 2, the silver nanoparticles were uniformly dispersed throughout the film, and the arrangement of silver nanoparticles on the surface and the interface with the base material was different from that inside the film. was not seen.

The silver luster film of the present invention can be used to improve the decorativeness of various objects to be decorated (molded objects), such as interior and exterior parts of automobiles, emblems, mobile phones, notebook computers, and shafts of golf clubs. It can be used to decorate cosmetic containers, etc., and for painting purposes.

Claims (6)

A silver glossy film laminated on a base material,
an interface layer (A) laminated on the base material and formed of composite nanoparticles (a) of a metal containing silver and a protective colloid;
A first phase that is laminated on this interface layer (A) and includes composite nanoparticles (b1) of a metal containing silver and a protective colloid and a first resin (b2), and a metal containing silver and a protective colloid. An intermediate layer (B) having a phase-separated structure comprising composite nanoparticles (b3) of )and,
A silver glossy film laminated on the intermediate layer (B) and a surface layer (C) formed of composite nanoparticles (c) of a metal containing silver and a protective colloid. The silver luster film according to claim 1, wherein the phase separation structure of the intermediate layer (B) is a sea-island structure. The silver luster film according to claim 2, wherein the first phase or the second phase is a dispersed phase, and the average diameter of the dispersed phase is 30 to 500 nm. The average thickness of the surface layer (C) and the interface layer (A) is 10 to 200 nm, respectively, and the average thickness of the intermediate layer (B) is 25 nm with respect to the average thickness of the surface layer (C). The silver luster film according to any one of claims 1 to 3, which is 250 times larger. A coating step of applying a liquid composition containing composite nanoparticles of a metal containing silver and a protective colloid, a first resin, a second resin, and a solvent onto a substrate, and a coating film formed with the liquid composition. The method for producing a silver luster film according to any one of claims 1 to 4, comprising a phase separation step of drying and phase separation by spinodal decomposition to obtain a silver luster film. A decorative body in which the silver luster film according to any one of claims 1 to 4 is laminated on a base material.