JP7024362B2 - Method for manufacturing silver nanoparticle laminate and silver nanoparticle laminate, and method for coloring silver nanoparticle laminate - Google Patents

Description

The present invention relates to a method for producing a silver nanoparticle laminate and a silver nanoparticle laminate, and a method for coloring the silver nanoparticle laminate.

Silver nanoparticles have electrical, thermal, and optical properties not found in other materials and are used in a wide range of products, from solar cells to sensors. Furthermore, unlike many other dyes and pigments, silver nanoparticles are extremely effective in absorbing and scattering light, and have colors depending on the size and shape of the particles. The strong relationship between light and silver nanoparticles is called surface plasmon resonance, which is because the conduction electrons on the metal surface cause collective vibration when excited by light of a specific wavelength, which causes unusual scattering and scattering. It causes absorption characteristics.

In general, a coating liquid in which metallic silver is dispersed is often used for metal wiring applications. For example, a pattern is formed on a wiring board with a coating liquid in which metallic silver is dispersed, and the metallic silver contained in the coating liquid is sintered to form a wiring. When metallic silver is used as a conductive material, it is known that it is necessary to sinter at a low temperature by utilizing the melting point depression due to the miniaturization of dispersed metallic silver. At present, finely divided nano-sized metal nanoparticles are expected as a material that can be sintered at low temperature.

However, the particles of metallic silver, which are so small as to show a melting point depression, tend to come into contact with each other and aggregate. In order to prevent this aggregation, it is necessary to add a dispersant to the above-mentioned coating liquid, but the addition of the dispersant inhibits the surface plasmon resonance peculiar to the metal nanoparticles and adversely affects the peculiar color development. May affect. Further, in order to produce a functional film having optical characteristics peculiar to silver nanoparticles, it is necessary to use a coating liquid having good dispersibility and not sintered at a low temperature. Further, when it is desired to produce a coating film having a metallic luster, it is necessary to give a metallic luster at a relatively low temperature after coating, and the sintering temperature must be able to be changed according to the application. Further, it is necessary to have a coating liquid composition that does not aggregate even if a resin component for improving film strength and adhesion to a substrate is added in addition to silver nanoparticles and a dispersant.

Conventionally, when trying to obtain silver nanoparticles, generally, an aqueous solution in which a silver salt such as silver nitrate or silver chloride is dissolved is used to reduce existing silver ions with some reducing agent to form a metal salt having a desired form. (Patent Document 1 to Patent Document 3). Further, particularly in the production of fine silver particles, a method of aggregating atomic silver into silver nanoparticles in a vacuum is also known (Patent Document 4).

Further, there is also known a method of producing silver nanoparticles via a silver oxalate amine complex by mixing silver oxalate and amine and thermally decomposing them (Patent Documents 5 and 6). According to this method, silver atoms generated by dissociation from the raw material compound do not go through the state of silver ions in the process of forming silver nanoparticles. Therefore, according to the above method, it is not necessary to mix a reducing agent for reducing silver ions, and it is possible to produce silver fine particles having a uniform average particle size by a simple method. Further, since the amino group of the amine molecule is coordinated on the surface of the silver particles during the decomposition of the amine complex, silver nanoparticles that can be dispersed in a certain organic solvent without adding a dispersant can be obtained.

Special Table 2012-509396 Gazette Japanese Unexamined Patent Publication No. 2012-180589 Japanese Unexamined Patent Publication No. 2012-140701 Japanese Unexamined Patent Publication No. 2002-121437 Japanese Unexamined Patent Publication No. 2012-162767 Japanese Patent No. 5574761

However, when only this silver nanoparticle dispersion liquid is applied to form a silver nanoparticle film, there is a problem that the transmitted light is limited to yellow and there are few kinds of colors that can be colored.
The present invention has been made in view of the above circumstances, and provides a silver nanoparticle laminate capable of increasing the types of colors that can be colored, a method for producing the same, and a method for coloring the silver nanoparticle laminate. The purpose is to do.

In order to solve the above problems, the silver nanoparticle laminate according to one aspect of the present invention comprises an undercoat layer and an overcoat layer formed on the undercoat layer, and the overcoat layer is a molecule. A compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule. It contains at least one of the compounds and silver nanoparticles, and the silver nanoparticles are dispersed in the overcoat layer. The "base layer" means a layer including at least one of the base material 1 and the base layer 2 described later.

Further, the method for producing a silver nanoparticles laminate according to one aspect of the invention includes a step of applying a silver nanoparticles-containing composition containing silver nanoparticles and a dispersion medium on the base layer, and at least one in the molecule. At least one of a compound having the above urethane bond and two or more polymerizable unsaturated double bonds and a compound having at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule. A step of applying the composition for an overcoat layer containing a compound that generates a polymerization initiation species by ionization radiation and a solvent onto the silver nanoparticles-containing composition coated on the base layer, and the overcoat. After the layer composition is dried, the overcoat layer composition is irradiated with the ionizing radiation to cure the overcoat layer composition to form an overcoat layer.
Further, in the method for coloring the silver nanoparticles laminate according to one aspect of the invention, at least a part of the silver nanoparticles of the silver nanoparticles laminate provided with the overcoat layer containing the silver nanoparticles is contained in the overcoat layer. The absorption wavelength of the silver nanoparticles is changed by changing the distance between the dispersed silver nanoparticles.

According to one aspect of the present invention, there is provided a method for producing a silver nanoparticle laminate and a silver nanoparticle laminate, and a method for coloring a silver nanoparticle laminate, which can increase the types of colors that can be colored. Is possible.

It is sectional drawing which shows typically the structure of the silver nanoparticle laminate which concerns on 1st and 2nd Embodiment of this invention. It is sectional drawing which shows typically the dispersion state of the silver nanoparticles in the silver nanoparticles laminated body which concerns on 1st Embodiment of this invention and the modification. It is sectional drawing which shows typically the dispersion state of the silver nanoparticles in the silver nanoparticle laminate which concerns on the 2nd Embodiment of this invention and the modification. It is a figure which shows typically the manufacturing process of the silver nanoparticle laminate which concerns on each Embodiment of this invention and each modification. It is a figure which shows typically the structure of the coating part which applies the silver nanoparticle dispersion liquid 4a and the composition 3a for an overcoat layer. It is a figure which shows typically the structure of the coating part which applies the silver nanoparticle dispersion liquid 4a and the composition 3a for an overcoat layer. It is a conceptual diagram for demonstrating the coloration in the silver nanoparticle laminate which concerns on 1st Embodiment of this invention and a modification thereof. It is a figure which shows the absorption spectrum in the silver nanoparticle laminate which concerns on the 1st Embodiment of this invention and the modification thereof. It is a conceptual diagram for demonstrating the coloration in the silver nanoparticle laminate which concerns on the 2nd Embodiment of this invention and the modified example thereof. It is an absorption spectrum of the silver nanoparticle laminated body which concerns on the 2nd Embodiment of this invention and the modification thereof. It is a figure which shows the scanning electron microscope image of the silver nanoparticles observed after applying the toluene solvent dispersion liquid of the silver nanoparticles obtained in Example 1 of this invention to a substrate and drying. It is a figure which shows the particle size distribution and the cumulative frequency (%) of the silver nanoparticles obtained in Example 1 of this invention. It is a figure which shows the structure of the monomer contained in the composition for an overcoat layer used in Examples 1 to 8 and Comparative Example 1 of this invention. It is a scanning electron microscope image of the silver nanoparticles contained in the overcoat layer which concerns on Example 9 of this invention. It is a scanning electron microscope image of the silver nanoparticles contained in the overcoat layer which concerns on Example 10 of this invention. It is a scanning electron microscope image of the silver nanoparticles contained in the overcoat layer which concerns on Example 11 of this invention. It is a scanning electron microscope image of the silver nanoparticles contained in the overcoat layer which concerns on Example 12 of this invention. It is a scanning electron microscope image of the silver nanoparticles contained in the overcoat layer which concerns on Example 13 of this invention. It is a scanning electron microscope image of the silver nanoparticles contained in the overcoat layer which concerns on Example 14 of this invention. It is an absorption spectrum of the silver nanoparticle laminate which concerns on Examples 15 to 20 of this invention.

Hereinafter, a method for producing a silver nanoparticle laminate and a silver nanoparticle laminate according to each embodiment of the present invention and each modification will be described with reference to the drawings. Here, the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, each embodiment and each modification shown below exemplify a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention is based on the material, shape, and shape of the constituent parts. And the structure etc. does not specify the following. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims described in the claims.

(Structure of silver nanoparticle laminate 5)
1. 1. First Embodiment FIG. 1 is a cross-sectional view schematically showing the structure of the silver nanoparticle laminate 5 according to the first embodiment of the present invention. The silver nanoparticle laminate 5 shown in FIG. 1 includes a base material 1, a base layer 2 formed on the base material 1, and an overcoat layer 3 formed on the base layer 2 in which silver nanoparticles 4 are dispersed. , At least. Further, the silver nanoparticle laminate 5 according to the first embodiment exhibits a yellow color. The silver nanoparticle laminate 5 according to the present embodiment and the second embodiment described later exhibits various colors. Therefore, the silver nanoparticle laminate 5 is generally also referred to as a "coloring film" or a "coloring film". Further, the "underlayer" is also called a "thin film layer" when the thickness is relatively thin, and is also called a "film" or a "thick film layer" when the thickness is relatively thick.
In addition, in this specification, "(meth) acrylate" means both "acrylate" and "methacrylate". For example, "urethane (meth) acrylate" refers to both "urethane acrylate" and "urethane methacrylate".
Hereinafter, the details of each of the above-mentioned layers will be described.

[Base material 1]
The base material 1 is a layer that supports the base layer 2. Therefore, the type of the base material does not matter as long as it can support and form the base layer 2. In the present embodiment, as the base material 1, for example, a PET (polyethylene terephthalate) film, a cellulose triacetate (TAC) film, a polymethacrylic acid ester film, or the like can be used.
The surface of the base material 1 may be treated so as to facilitate the formation of the base layer 2. Examples of the treatment applied to the surface of the base material 1 include corona treatment. Since the base material 1 is a layer that supports the base layer 2 as described above, if the base layer 2 is thick and has sufficient mechanical strength, the silver nanoparticle laminate of the present embodiment is used. Does not have to include the base material 1.

[Base layer 2]
The base layer 2 is a layer having a thickness of 4 μm to 60 μm that supports the overcoat layer 3. In the present embodiment, the base layer 2 is, for example, a layer formed by polymerizing one kind or two or more kinds of (meth) acrylic acid ester compounds. More specifically, the underlayer 2 is a layer formed by using one kind or two or more kinds of urethane acrylic oligomers, and for example, the underlayer composition 2a described later is cured in an environment purged with nitrogen. It is a layer formed by. The underlayer 2 may contain a compound that generates a polymerization initiator by ionizing radiation, for example, a photopolymerization initiator. In this embodiment, the overcoat layer 3 may be formed on the base material 1 without providing the base layer 2.

[Overcoat layer 3]
The overcoat layer 3 is a layer formed on the base layer 2 and having a thickness of 1 μm to 7 μm.
The overcoat layer 3 is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group and one or more non-polymerizable groups in the molecule. It contains at least one of the compounds having a saturated double bond and is, for example, a layer containing a three-dimensional crosslinked structure obtained by irradiation with ionizing radiation. Specifically, the overcoat layer 3 is a resin having a three-dimensional crosslinked structure in which a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds is polymerized in the molecule, particularly a urethane bond. A resin having a three-dimensional crosslinked structure and a resin having a three-dimensional crosslinked structure obtained by polymerizing at least one carboxy group and a compound having one or more polymerizable unsaturated double bonds in the molecule are included. Polymerization is preferred. The overcoat layer 3 may contain a compound that generates a polymerization initiator by ionizing radiation, for example, a photopolymerization initiator.

Further, the compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the above-mentioned molecule contains, for example, at least one of a urethane (meth) acrylate monomer and an oligomer as a main component. It is a compound. The "main component" here means the component having the largest mass ratio. Further, the compound having at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule is, for example, a compound having acrylic acid. Specific examples of the compound having an unsaturated double bond that can be used in this embodiment will be described later.
Further, the above-mentioned photopolymerization initiator is an initiator for photopolymerizing the above-mentioned polymerizable compound. Therefore, any kind of the above-mentioned polymerizable compound can be photopolymerized as long as it can be photopolymerized. Specific examples of the photopolymerization initiator that can be used in this embodiment will be described later.
Further, the overcoat layer 3 contains monodispersed silver nanoparticles 4 in addition to the above-mentioned resin.

FIG. 2A is a cross-sectional view schematically showing a dispersed state of silver nanoparticles 4 in the silver nanoparticles laminate 5 according to the first embodiment. As shown in FIG. 2A, the silver nanoparticles 4 have high dispersibility and are monodispersed in the overcoat layer 3.
Further, the surface of the silver nanoparticles 4 is covered with, for example, a protective molecule containing an alkyldiamine having a primary amino group and a tertiary amino group as a main component. The "main component" here means the most abundant component (molecule) among the plurality of protected molecules covering the surface of the silver nanoparticles 4. The average primary particle diameter (D50) of the silver nanoparticles 4 is, for example, in the range of 1 nm or more and 30 nm or less. Further, the above-mentioned silver nanoparticles 4 can be dispersed in an organic solvent.
The average primary particle size was determined from the particle size distribution measured with a 0.1% by mass toluene solution using a Nanotrac UPA-EX150 particle size distribution meter (dynamic light scattering method, manufactured by Nikkiso Co., Ltd.).

Hereinafter, the first modification and the second modification of the first embodiment will be described.
1.1 First Modification Example The configuration of the silver nanoparticle laminate 5 according to the first modification of the first embodiment is the same as the configuration of the silver nanoparticle laminate 5 according to the first embodiment described above. The difference is that a part of the silver nanoparticles 4 is aggregated in the overcoat layer 3.
Therefore, in this modification, the partially aggregated silver nanoparticles 4 will be described with reference to FIG. 2 (b).
FIG. 2B is a cross-sectional view schematically showing an aggregated state (dispersed state) of silver nanoparticles 4 in the silver nanoparticle laminate 5 according to the first modification of the first embodiment.
As shown in FIG. 2B, the silver nanoparticles 4 in this modification have lower dispersibility than the silver nanoparticles 4 in the first embodiment, and a part thereof is aggregated. The average secondary particle diameter (D50) of the aggregated silver nanoparticles 4 is, for example, about 10 nm to 200 nm.
The silver nanoparticle laminate 5 according to the first modification of the first embodiment has an orange color.

1.2 Second Modification Example The configuration of the silver nanoparticle laminate 5 according to the second modification of the first embodiment is the same as the configuration of the silver nanoparticle laminate 5 according to the first embodiment described above. It differs in that most of the silver nanoparticles 4 are aggregated in the overcoat layer 3.
Therefore, in this modification, the silver nanoparticles 4 in which most of them are aggregated will be described with reference to FIG. 2 (c).
FIG. 2C is a cross-sectional view schematically showing an aggregated state (dispersed state) of silver nanoparticles 4 in the silver nanoparticle laminate 5 according to the second modification of the first embodiment.
As shown in FIG. 2C, the silver nanoparticles 4 in the present modification have lower dispersibility than the silver nanoparticles 4 in the first modification, and most of them are aggregated. The average secondary particle diameter (D50) of the aggregated silver nanoparticles 4 is, for example, about 100 nm to 1000 nm.
The silver nanoparticle laminate 5 according to the second modification of the first embodiment exhibits a reddish purple color.

2. 2. Second Embodiment FIG. 1 is a cross-sectional view schematically showing the structure of the silver nanoparticle laminate 5 according to the second embodiment of the present invention. The silver nanoparticle laminate 5 shown in FIG. 1 includes a base material 1, a base layer 2 formed on the base material 1, and an overcoat layer 3 formed on the base layer 2 and containing silver nanoparticles 4. , At least. That is, the configuration of the silver nanoparticle laminate 5 according to the second embodiment is the same as the configuration of the silver nanoparticle laminate 5 according to the first embodiment described above, but the silver nanoparticles 4 overlap with the base layer 2. It differs in that it aggregates in layers along the interface with the coat layer 3.
Therefore, in the present embodiment, the aggregated state of the silver nanoparticles 4 will be described with reference to FIG.

FIG. 3A is a cross-sectional view schematically showing an aggregated state of silver nanoparticles 4 in the silver nanoparticles laminate 5 according to the second embodiment.
The silver nanoparticles 4 in the present embodiment are aggregated so as to be laminated along the interface between the base layer 2 and the overcoat layer 3. More specifically, almost all of the silver nanoparticles 4 existing in the overcoat layer 3 are aggregated so as to be laminated along the interface between the undercoat layer 2 and the overcoat layer 3. Further, in the present embodiment, the thickness of the region where the silver nanoparticles 4 are aggregated, that is, the layer thickness of the silver nanoparticles layer is about 30 nm to 80 nm. From this, it is considered that the inter-particle distance is longer than in the case of the first modification of the second embodiment described later.
The silver nanoparticle laminate 5 according to the second embodiment exhibits a reddish purple color.

Hereinafter, the first modification of the second embodiment will be described.
2.1 First Modification Example The configuration of the silver nanoparticle laminate 5 according to the first modification of the second embodiment is the same as the configuration of the silver nanoparticle laminate 5 according to the second embodiment described above. The aggregated state of the silver nanoparticles 4 in the overcoat layer 3 is different.
Therefore, in this modification, the aggregated state of the silver nanoparticles 4 will be described with reference to FIG. 3 (b).
FIG. 3B is a cross-sectional view schematically showing the aggregated state of the silver nanoparticles 4 in the silver nanoparticles laminate 5 according to the first modification of the second embodiment.
As shown in FIG. 3B, the silver nanoparticles 4 in the present modification are layered along the interface between the base layer 2 and the overcoat layer 3, similarly to the silver nanoparticles 4 according to the second embodiment. It is agglomerated. Here, the distance between the silver nanoparticles 4 in this modification is shorter than the distance between the silver nanoparticles 4 in the second embodiment. That is, the silver nanoparticles 4 in this modification have lower dispersibility than the silver nanoparticles 4 in the second embodiment, and a part thereof is further aggregated. More specifically, almost all of the silver nanoparticles 4 existing in the overcoat layer 3 are aggregated so as to be laminated along the interface between the undercoat layer 2 and the overcoat layer 3. Further, in this modification, the thickness of the region where the silver nanoparticles 4 are aggregated, that is, the layer thickness of the silver nanoparticles layer is about 20 nm to 40 nm. From this, it is considered that the inter-particle distance is shorter than that of the first embodiment described above.
The silver nanoparticle laminate 5 according to this modification has a purple color.

(Manufacturing process of silver nanoparticle laminate 5)
Before explaining the manufacturing process of each silver nanoparticle laminate 5 according to the first embodiment and its modification and the second embodiment and its modification described above, first, the underlayer used to form the underlayer 2 is formed. The preparation of the composition 2a for use will be described. Next, the synthesis of silver nanoparticles 4 will be described. Next, the preparation of the silver nanoparticles dispersion liquid (silver nanoparticles-containing composition) 4a containing the silver nanoparticles 4 will be described. Next, the preparation of the overcoat layer composition 3a used for forming the overcoat layer 3 will be described. Finally, the manufacturing process of each silver nanoparticle laminate 5 according to the above-mentioned first embodiment and its modification, and the second embodiment and its modification will be described with reference to FIG.

[Preparation of Composition 2a for Underlayer]
The composition 2a for the underlayer of the present embodiment is a coating liquid composition containing at least a (meth) acrylic acid ester compound and a compound that generates a polymerization initiator by ionizing radiation, that is, a polymerization initiator. This point will be described in detail below.
The composition 2a for the underlayer contains at least one (meth) acrylate resin as the (meth) acrylic acid ester compound.
For example, the composition 2a for the underlayer may contain at least the acrylate resin A (hereinafter, also simply referred to as “resin A”) as the (meth) acrylate resin. The resin A is, for example, TMPTA (trimethylolpropane triacrylate) or DPHA (dipentaerythritol hexaacrylate), and the composition 2a for the underlayer may contain one or more kinds of acrylic monomers.

Further, the composition 2a for the underlayer contains two types of urethane (meth) acrylate resin B (hereinafter, also simply referred to as “resin B”) and urethane (meth) acrylate resin C (hereinafter, simply referred to as “resin B”) as the (meth) acrylic acid ester compound. Hereinafter, it may simply contain at least "resin C"). Resin B is an oligomer containing two acryloyl groups or methacryloyl groups in one molecule and having a molecular weight of 2000 or less. Further, the resin C is an oligomer containing two or three acryloyl groups or methacryloyl groups in one molecule and having a molecular weight of 3000 or more and 20000 or less. In the composition 2a for the base layer containing the two types of urethane acrylate oligomers, the ratio ( _WB / _WC ) of the mass% (WB) of the resin _B to the mass% ( _WC ) of the resin C is 30 mass. It is preferably in the range of% / 70% by mass to 70% by mass / 30% by mass.

In the present embodiment, as described above, as the resin B, an oligomer containing two acryloyl groups or methacryloyl groups in one molecule is used, and as the resin C, two or three acryloyl groups or methacryloyl groups in one molecule. It is preferable to use an oligomer containing. This is because when there is only one acryloyl group or methacryloyl group, it is difficult to form the target photocurable resin film, and tack may occur due to insufficient curing. Further, when the number of acryloyl groups or methacryloyl groups is four or more, curling may occur due to the large curing shrinkage, and the tensile elongation of the coating film may be significantly lowered.

In the base layer 2 formed of the base layer composition 2a, the resin B mainly contributes to the improvement of the strength. Therefore, the photo-cured product obtained by photo-curing a coating liquid containing resin B and an ultraviolet polymerization initiator and not containing resin C has a maximum stress of 60 N / mm ² or more in a tensile test and a tensile elongation. It is preferably 10% or less. Further, in order to obtain the above tensile properties, the molecular weight of the resin B is preferably 2000 or less. If the molecular weight of the resin B is larger than 2000, the viscosity of the coating liquid becomes high and the coating becomes difficult.

Examples of the resin B include urethane acrylate C-1 (Shin Nakamura Chemical Industry Co., Ltd.), AH-600, AT-600 (Kyoeisha Chemical Co., Ltd.) and UA-1280 described in JP2013-159691. , UA-1280MK (Shin Nakamura Chemical Industry Co., Ltd.), Shikou UV6300B, UV7620A, UV7600B (Nippon Synthetic Chemical Industry Co., Ltd.), UF-8001G (Kyoeisha Chemical Co., Ltd.) and the like can be used. That is, as the resin B, an oligomer of urethane (meth) acrylate can be used. Among these, UA-1280MK can be particularly preferably used.

Further, as the resin C, for example, purple light UV7000B, purple light UV3520 (Nippon Synthetic Chemistry Co., Ltd.) and the like can be used. That is, as the resin C, an oligomer of urethane (meth) acrylate can be used. Among these, purple light UV7000B can be particularly preferably used.
Further, as the (meth) acrylic acid ester compound contained in the composition 2a for the underlayer, toughness and elongation are important in order to be easily peeled off from the base material 1 such as PET and to be formed as a self-supporting film. Parameters. Therefore, when only oligomers or monomers other than urethane (meth) acrylate are used, there may be problems such as large curl of the cured film and inability to peel off from the substrate 1.

The composition 2a for the base layer containing only the acrylic monomer, for example, the composition 2a for the base layer containing the acrylic monomer TMPTA (resin A) and the acrylic monomer DPHA (resin A) (TMPTA / DPHA =). 8/2) was cured in a nitrogen-purged environment to form a base layer 2, and a composition 3a for an overcoat layer containing UA-306I and DPE6A-MS, which will be described later, was placed on the base layer 2. The maximum absorption wavelength of the silver nanoparticles laminate 5 produced by coating and curing is 407 nm. Further, a silver nanoparticle laminate produced by applying and curing the composition 3a for an overcoat layer containing UA-306I and DPE6A-MP, which will be described later, on the base layer 2 formed in the same manner as described above. The maximum absorption wavelength of 5 is 528 nm.

Further, the underlayer composition 2a (TMPTA / DPHA = 8/2) containing TMPTA (resin A) and DPHA (resin A) is cured in the air to form the underlayer 2, and the underlayer is formed. The maximum absorption wavelength of the silver nanoparticle laminate 5 produced by applying and curing the composition 3a for an overcoat layer containing UA-306I and DPE6A-MS, which will be described later, on No. 2 is 408 nm. Further, a silver nanoparticle laminate produced by applying and curing the composition 3a for an overcoat layer containing UA-306I and DPE6A-MP, which will be described later, on the base layer 2 formed in the same manner as described above. The maximum absorption wavelength of 5 is 542 nm.
As described above, although the base layer 2 formed by using the composition 2a for the base layer containing only the acrylic monomer cannot be formed as a self-standing film, the silver nanoparticle laminate 5 provided with the base layer 2 is the same. It is possible to change the color.

A compound that generates a polymerization initiator by ionizing radiation for curing the (meth) acrylic acid ester compound, that is, a photoradical polymerization initiator similar to that of the overcoat layer composition 3a described later is used as the polymerization initiator. Can be done. Specifically, for example, Esacure ONE (Lamberti) can be used as the photopolymerization initiator.
The content of the polymerization initiator is preferably in the range of 0.5% by mass or more and 1% by mass or less based on the total solid content in the composition 2a for the base layer which is the coating liquid. If the content of the polymerization initiator is less than 0.5% by mass, the film hardness may become too low. Further, if the content of the polymerization initiator is more than 1% by mass, the film hardness may become too high.

Further, the composition 2a for the base layer may further contain a solvent. The solvent contained in the composition 2a for the underlayer can be appropriately selected from acetone, which is a ketone solvent having good compatibility with the resin A and the resin B, or methyl ethyl ketone in consideration of coating suitability and the like.
In the present embodiment, in addition to the above-mentioned components, if necessary, compatible additives such as plasticizers, stabilizers, surfactants, leveling agents, coupling agents and the like are used as objects of the present embodiment. Can be added within a range that does not impair. However, it is preferable not to add fillers for suppressing curl or increasing hardness because they cause a decrease in transmittance and a problem in dispersibility.

[Synthesis of silver nanoparticles 4]
Among the silver-containing compounds, a silver compound that is easily decomposed by heating to produce metallic silver is preferably used as a raw material for silver constituting the silver nanoparticles 4. Examples of such a silver compound include silver carboxylic acid obtained by combining carboxylic acid such as formic acid, acetic acid, oxalic acid, malonic acid, benzoic acid and phthalic acid with silver, silver chloride, silver nitrate, silver carbonate and the like. .. Among these silver compounds, silver oxalate is preferably used from the viewpoint that a metal is easily generated by decomposition and impurities other than silver are less likely to be generated. Silver oxalate has a high silver content, and oxalate ions are decomposed and removed as carbon dioxide by heating. Therefore, it can be said that it is advantageous in that metallic silver can be obtained as it is by thermal decomposition without the need for a reducing agent, and impurities are less likely to remain. Therefore, the case where silver oxalate is used as the silver compound will be described below. However, as described above, it goes without saying that in a complex compound formed between a silver compound and a predetermined diamine, the diamine is not limited to silver oxalate as long as it is coordinated to a silver atom. ..

<Silver oxalate>
The silver oxalate used in the present embodiment is not limited, and for example, commercially available silver oxalate can be used. Further, 20 mol% or less of the oxalate ion of silver oxalate may be replaced with at least one of a carbonate ion, a nitrate ion and an oxide ion, for example. In particular, when 20 mol% or less of oxalate ion is replaced with carbonate ion, there is an effect of enhancing the thermal stability of silver oxalate. If the substitution amount exceeds 20 mol%, the complex compound may be difficult to thermally decompose. In particular, in the case of a oxalate ion, an alkyldiamine, and a silver complex compound containing an alkyldiamine having a boiling point of 250 ° C. or lower, coated silver nanoparticles can be obtained with high efficiency by thermal decomposition at a low temperature of 100 ° C. or lower.

In the present embodiment, a predetermined alkyldiamine is added to the silver compound to form a complex compound of the silver compound and the alkyldiamine. This complex compound contains silver, alkyldiamine and oxalate ions. In this complex compound, the nitrogen atom contained in the amine is coordinated to each silver atom contained in the silver compound via its unshared electron pair to form the complex compound. Inferred.
Considering the ease of coordination of the alkyldiamine to the silver atom, the amino group is preferably RNH ₂ (R is a hydrocarbon group) which is a primary group, and R ₃ N (R is a hydrocarbon group) which is a tertiary amino group. If R is a hydrocarbon group), it becomes spatially difficult. Therefore, if the alkyldiamine has a primary amino group (primary amino group) and a tertiary amino group (tertiary amino group), the primary amino group selectively coordinates with the silver atom. The tertiary amino group faces outward depending on the molecular chain. Although the secondary amino group can be coordinated, it is preferable to use a primary amino group and a tertiary amino group because they are expensive due to synthetic problems and their reactivity is lower than that of the primary group.

<Alkyldiamine>
The structure of the alkyldiamine used in the present embodiment is not particularly limited. Since the alkyldiamine reacts with silver oxalate to form the above-mentioned complex compound, it is necessary that at least one amino group is a primary amino group or a secondary amino group, and the primary amino group is used. It is preferable to have. Further, in order to enhance the affinity with the non-polar dispersion medium, it is desirable that the other amino group is a tertiary amino group. Examples of the alkyldiamine include N, N-dimethylethylenediamine, N, N-diethylethylenediamine, N, N-dimethyl-1,3-propanediamine, N, N-diethyl-1,3-propanediamine, N, N. -Dimethyl-1,5-diamino-2-methylpentane, N, N-dimethyl-1,6-hexanediamine and the like can be mentioned, but this is not the case. Further, a plurality of different alkyldiamines may be reacted with silver oxalate at the same time.

The metal-silver atoms thus coordinating with diamines rapidly aggregate after their formation and form metal bonds with each other to form silver nanoparticles. At this time, the diamine coordinated to each silver atom forms a protective film on the surface of the silver nanoparticles. Therefore, after a certain number of silver atoms gather to form silver nanoparticles, the protective film of the diamine is used. It is considered that it will be difficult for the above silver atoms to bond. Therefore, even when the decomposition of the silver compound contained in the complex compound and the formation of silver nanoparticles are carried out in a state where no solvent is present and silver atoms are present at an extremely high density, the average primary particle diameter is typically average. It is considered that silver nanoparticles having the same particle size can be stably obtained in the range of (D50) of 1 nm or more and 30 nm or less.

In the formation of the complex compound of the silver compound and the diamine, the molar ratio of the silver atom and the diamine is preferably in the range of 1: 1 to 1: 4, and preferably in the range of 1: 2 to 1: 4. Is more preferable. In the formation of the complex compound of the silver compound and the diamine, when the amount of the diamine becomes smaller than the above range, the proportion of the silver atom to which the diamine is not coordinated increases, and the obtained silver nanoparticles are enlarged. Become. Further, since the presence of diamine in an amount of twice or more the amount of silver atom makes it possible to stably obtain silver nanoparticles having an average primary particle diameter (D50) of about 30 nm or less, the amount of diamine of this degree can be used. We believe that all silver atoms can be coordinated by diamine. Further, when the amount of diamine is four times or more the amount of silver atoms, the density of silver atoms in the reaction system decreases, and the final recovery yield of silver decreases. Therefore, the amount of diamine used is four times the amount of silver atoms. The following is preferable. Further, when the molar ratio of silver atom to diamine is about 1: 1, there is no dispersion medium in which all amines are coordinated to the silver atom to form a complex compound and hold the reaction system. Therefore, it is also preferable to mix a reaction solvent such as methanol as needed.

When the complex compound of the silver compound and the diamine is heated with stirring, a suspension exhibiting a blue luster is obtained. By removing excess diamine and the like from this suspension, silver nanoparticles whose surface is coated with the protective molecule according to the present embodiment (hereinafter, also simply referred to as “silver nanoparticles”) can be obtained. The conditions for heating a complex compound of a silver compound and a diamine to obtain silver nanoparticles are such that the temperature, pressure, and atmosphere for thermal decomposition are appropriately adjusted according to the type of silver compound and diamine used. You can choose. At this time, from the viewpoint of preventing the generated silver nanoparticles from being contaminated by the reaction with the atmosphere for thermal decomposition and the protective film covering the surface of the silver nanoparticles from being decomposed, an argon atmosphere or the like is not used. It is preferable to thermally decompose the silver compound in an active atmosphere. On the other hand, when silver oxalate is used as the silver compound, the reaction space is protected by carbon dioxide generated by the decomposition of oxalate ions, so by heating the complex compound of silver oxalate and diamine in the atmosphere. Thermal decomposition of silver oxalate is possible.

The temperature at which the complex compound of the silver compound and the diamine is heated for the thermal decomposition of the silver compound is preferably equal to or lower than the boiling point of the diamine used in general from the viewpoint of preventing the desorption of the diamine. In the present embodiment, generally, by heating to about 80 to 130 ° C., silver nanoparticles having a protective film formed of diamine can be obtained.
As mentioned above, in this embodiment, the total amount of silver atom: diamine is 1: 1 (molar ratio), as compared with other methods for synthesizing silver nanoparticles which generally require an excess amount of alkylamine with respect to silver. However, since silver nanoparticles can be synthesized in high yield, the amount of alkyldiamine used can be reduced. In addition, since carbon dioxide generated by the thermal decomposition of oxalate ions is easily removed from the reaction system, there are no by-products derived from the reducing agent, and silver nanoparticles can be easily separated from the reaction system. The purity of nanoparticles is also high.

[Preparation of silver nanoparticle dispersion liquid 4a]
When the silver nanoparticles 4 according to the present embodiment are dispersed in a sol or the like used as a dispersion medium, that is, when the silver nanoparticles dispersion liquid 4a is prepared, the silver nanoparticles 4 are 2% by mass or more with respect to the dispersion medium. It is preferably in the range of 20% by mass or less. Further, under conditions that the protective film that protects the surface of the silver nanoparticles 4 is not detached, the excess alkyldiamine and the like used when forming the protective film are removed and replaced with the solvent used to protect the silver nanoparticles 4. It is preferable to obtain a dispersion liquid in which silver nanoparticles 4 having a film are dispersed. Examples of the dispersion medium for dispersing the silver nanoparticles 4 having the protective film include toluene, tarpineol C manufactured by Nippon Terpen Chemical Co., Ltd., dihydro tarpineol, and tersolve THA-90. Further, some of these solvents may be mixed and used. Further, among these dispersion media, toluene is particularly preferable. The above-mentioned dispersion medium can be present in the silver nanoparticles dispersion 4a in an amount of up to 97% by mass of the entire silver nanoparticles dispersion 4a, but if it exceeds 20% by mass, it becomes a metallic coating film and is less than 2% by mass. Then the paint film color is too light. Therefore, it is preferably in the range of 2% by mass or more and 20% by mass or less.

When the silver nanoparticles 4 according to the present embodiment are exposed to the atmosphere or the like, the protective film is detached even at a low temperature, and coagulation sintering of the silver nanoparticles 4 is started. Therefore, when the silver nanoparticles 4 are replaced with an appropriate solvent from an alkyldiamine or the like, it is preferable to select and replace the conditions under which the silver nanoparticles 4 are not exposed to the atmosphere or the like.
In the present embodiment, in addition to the above-mentioned components, if necessary, compatible additives such as plasticizers, stabilizers, surfactants, leveling agents, coupling agents and the like are used as objects of the present embodiment. Can be added within a range that does not impair.

[Preparation of composition 3a for overcoat layer]
In the present embodiment, the composition 3a for an overcoat layer is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule and at least one carboxy in the molecule. It contains at least one of the compounds having a group and one or more polymerizable unsaturated double bonds. More preferably, the composition 3a for an overcoat layer is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule and at least one carboxy group in the molecule. And compounds with one or more polymerizable unsaturated double bonds. The composition 3a for an overcoat layer contains a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group and one or more in the molecule. For an overcoat layer of a compound having at least one or more carboxy groups and one or more polymerizable unsaturated double bonds in the molecule, when both compounds having a polymerizable unsaturated double bond are included. The ratio of the composition 3a to the whole is 10% by mass or more and 40% by mass or less because the absorption wavelength of the silver nanoparticle laminate 5 does not change when the ratio is small and the curing is insufficient when the ratio is too large. It is preferably within the range, and particularly preferably 20% by mass. The composition 3a for an overcoat layer contains a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group and 1 in the molecule. When containing both compounds having more than one polymerizable unsaturated double bond, the mass of the compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule ( The mass ratio ( _WC1 / _WC2 ) of _WC1 ) to a compound ( _WC2 ) having at least one or more carboxy groups and one or more polymerizable unsaturated double bonds in the molecule is, for example, 8. It is / 2.

Examples of the compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule include the hydroxyl group of a polyhydric alcohol having two or more alcoholic hydroxyl groups in one molecule. However, those in which two or more (meth) acrylic acids are esterified are preferable. In addition, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, and the like are mentioned above, including those in which a reactive acryloyl group is bonded to an acrylic resin skeleton. Can be used as a compound of. Further, those having an acryloyl group bonded to a rigid skeleton such as melamine or isocyanuric acid can also be used. Among those compounds, in the present embodiment, particularly when at least one of a urethane (meth) acrylate monomer and an oligomer is used, the hardness and flexibility of the overcoat layer 3 formed by using the composition 3a for the overcoat layer can be determined. It can be significantly improved.

As the urethane (meth) acrylate having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, which is preferable in the present embodiment, generally, an isocyanate monomer or a prepolymer is added to a polyester polyol. Examples thereof include those formed by reacting a (meth) acrylic monomer having a hydroxyl group with a product obtained by the reaction.

Specific examples include pentaerythritol triacrylate hexadiamine isocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexadiamine isocyanate urethane prepolymer, pentaerythritol triacrylate toluenediamine isocyanate urethane prepolymer, and dipentaerythritol pentaacrylate toluenediisocyanate urethane prepolymer. Polymers, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymers, dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymers and the like can be used. In addition, these monomers can be used alone or in admixture of two or more. Further, these may be monomers or may be partially polymerized oligomers. These resins are crosslinked by applying energy such as heat, ultraviolet rays, and electron beams. These compounds are appropriately selected in consideration of film strength, adhesion to a substrate, and curl amount.

As urethane (meth) acrylate, Nagase Chemtech Co., Ltd .; (trade name "Denacol" series, etc.), Shin-Nakamura Chemical Co., Ltd .; (trade name "NK Ester" series, etc.), DIC Co., Ltd. (trade name "UNDIC" series, etc.) , Nippon Oil & Fats Co., Ltd .; (trade name "Blemmer" series, etc.), Nippon Kayakusha; (trade name "KAYARAD" series, etc.), Kyoeisha Chemical Co., Ltd .; (trade name "light ester" series, "light acrylate" series, etc.) , Daicel Ornex; (trade name "Ebecryl" series, etc.), Negami Kogyo Co., Ltd .; (trade name "Art Resin" series, etc.), Nippon Synthetic Chemical Industry Co., Ltd .; (trade name; "Shikou" series, etc.), etc. Can be used.

Specifically, U-4HA, U-6HA, UA-100A, U-6LPA, U-15HA, UA-32P, UA-33H, UA-53H, U-324A, etc. of Shin-Nakamura Chemical Co., Ltd. UA-306H, UA-306T, UA-306I, etc., Daicel Ornex's Ebecrily-1290, Ebecrily-1290K, Ebecrily-5129, etc., Negami Kogyo Co., Ltd. UN-3220H, UN-3220HB, UN-3220HS, etc. You can, but this is not the case.

Examples of the compound having at least one or more carboxy groups and one or more polymerizable unsaturated double bonds in the molecule include esters of one or more carboxy groups and one or more acrylic acids in one molecule. A monomer having a compound is preferable. Above all, in the present embodiment, particularly when a (meth) acrylate monomer having a structure of succinic acid or phthalic acid is used, the shift of the maximum absorption wavelength in the silver nanoparticles laminate 5 is remarkable.

Specific examples include dipentaerythritol pentaacrylate phthalic acid modified product, pentaerythritol triacrylate phthalic acid modified product, dipentaerythritol pentaacrylate succinic acid modified product, pentaerythritol triacrylate succinic acid modified product, 2-acrylate. Loyloxyl ethyl-phthalic acid, 2-methacryloyloxyethyl-succinic acid and the like can be used. In addition, these monomers can be used alone or in admixture of two or more. These resins are crosslinked by applying energy such as heat, ultraviolet rays, and electron beams.
As (meth) acrylate monomers having a structure of succinic acid or phthalic acid, Kyoeisha Chemical Co., Ltd .; (developed product, product name "light acrylate" series, etc.), Shin-Nakamura Chemical Co., Ltd .; (trade name "NK ester" series, etc.) Products such as can be used.

Specifically, Kyoeisha Chemical Co., Ltd.'s light ester HO-MS (N) (2-methacryloyloxyethyl succinic acid), HOA-MLP (N), HOA-MS (N) (2-acryloyloxyethyl succinic acid) ), Light acrylate HOA-HH (N) (2-acryloyloxyethyl hexahydrophthalic acid), HOA-MPL (2-acryloyloxyethyl phthalic acid), DPE6A-MS (dipentaerythritol pentaacrylate succinic acid modified product) ), PE3A-MS (pentaerythritol triacrylate succinic acid modified product), DPE6A-MP (dipentaerythritol pentaacrylate phthalic acid modified product), PE3A-MS (pentaerythritol triacrylate phthalic acid modified product), Shin-Nakamura Chemical Co., Ltd. NK ester SA and the like can be mentioned, but this is not the case.

The ratio (content ratio) of the compound having a polymerizable unsaturated double bond constituting the overcoat layer composition 3a of the present embodiment is 50% or more and 95% or less in the overcoat layer composition 3a. It is preferably within the range, and may be diluted with a (meth) acrylate monomer or a solvent as needed.
The composition 3a for an overcoat layer contains two or more compounds having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least 1 in the molecule. There may be two kinds of compounds having one or more carboxy groups and one or more polymerizable unsaturated double bonds. That is, the composition 3a for the overcoat layer may be a mixed system containing four or more kinds of the above-mentioned oligomers or monomers.

For example, the underlayer composition 2a (UA-1280MK / UV7000B = 8/2) containing UA-1280MK and UV7000B is cured in a nitrogen-purged environment to form the underlayer 2 and above the underlayer 2. 3a (UA-306I, DPE6A-MS and DPE6A-MP = 6/2/2) for an overcoat layer containing UA-306I, DPE6A-MS and DPE6A-MP is applied and cured. The maximum absorption wavelength of the silver nanoparticle laminate 5 produced in the above process is 530 nm. Further, the composition 2a for the base layer (UA-1280MK / UV7000B = 8/2) containing UA-1280MK and UV7000B is cured in the air to form the base layer 2, and the UA is placed on the base layer 2. It was produced by applying and curing a composition 3a for an overcoat layer (UA-306I / DPE6A-MS / DPE6A-MP = 6/2/2) containing -306I, DPE6A-MS and DPE6A-MP. The maximum absorption wavelength of the silver nanoparticle laminate 5 is 560 nm.

Further, the underlayer composition 2a (UA-1280MK / UV7000B = 8/2) containing UA-1280MK and UV7000B is cured in a nitrogen-purged environment to form the underlayer 2 and above the underlayer 2. 3a (UA-306I / DPE6A-MS / DPE6A-MP = 8/1 / 1) for an overcoat layer containing UA-306I, DPE6A-MS and DPE6A-MP is applied and cured. The maximum absorption wavelength of the silver nanoparticle laminate 5 produced in the above process is 522 nm. Further, the composition 2a for the base layer (UA-1280MK / UV7000B = 8/2) containing UA-1280MK and UV7000B is cured in the air to form the base layer 2, and the UA is placed on the base layer 2. It was produced by applying and curing a composition 3a for an overcoat layer (UA-306I / DPE6A-MS / DPE6A-MP = 8/1/1) containing -306I, DPE6A-MS and DPE6A-MP. The maximum absorption wavelength of the silver nanoparticle laminate 5 is 550 nm.

The composition 3a for an overcoat layer of the present embodiment further contains a compound that generates a polymerization initiator by ionizing radiation, that is, a polymerization initiator. Examples of the polymerization initiator contained in the overcoat layer composition 3a, particularly the photoradical polymerization initiator, include acetophenones, benzophenones, α-hydroxyketones, benzylmethyl ketal, α-aminoketone, monoacylphosphine oxide, and bis. Acylphosphine oxide or the like is used alone or in combination. Specifically, BASF's Irgacure 184, Irgacure 651, Irgacure 1173, Irgacure 907, Irgacure 369, Irgacure 819, Irgacure TPO, Lamberti's Esacure KIP-150, Es, etc. do not have.
The amount of the polymerization initiator used is preferably in the range of 0.5% by mass or more and 10% by mass or less, particularly 1% by mass or more and 5% by mass or less, based on the total solid content in the composition 3a for the overcoat layer. It is preferably within the range of. Even if it is at least more than this range, the hardness of the overcoat layer tends to be low.

Further, the composition 3a for the overcoat layer further contains a solvent. Examples of the solvent used in the composition 3a for the overcoat layer include methyl acetate, ethyl acetate, isopropyl acetate, tetrahydrofuran, 1,3-dioxolane, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, methanol, ethanol and 2-. Propanol, 1-butanol and the like can be used. The solvent is not limited to one type, and a plurality of solvents may be mixed and used. Further, it is preferable to contain 80 wt% or more of these solvents. Among these solvents, methyl ethyl ketone is particularly preferable.

In the present embodiment, in addition to the above-mentioned components, if necessary, compatible additives such as plasticizers, stabilizers, surfactants, leveling agents, coupling agents and the like are used as objects of the present embodiment. Can be added within a range that does not impair. However, it is preferable not to add fillers for suppressing curl or increasing hardness because they cause a decrease in transmittance and a problem in dispersibility.

[Manufacturing process of silver nanoparticle laminate 5]
Each step for manufacturing the silver nanoparticle laminate 5 according to the first embodiment and its modification and the second embodiment and its modification described above will be described with reference to FIG.
As shown in FIG. 4A, the above-mentioned composition for the base layer 2a is placed on the base material 1 such as a PET film, and for example, a bar coater is placed so that the thickness of the composition 2a for the base layer is 4 μm to 60 μm. Apply using.

Next, the composition 2a for the base layer applied on the base material 1 is placed in an environment of, for example, 90 ° C. for 100 seconds to be dried. Then, the composition 2a for the base layer is irradiated with ionizing radiation or the like to cure the composition 2a for the base layer. In the present embodiment, the composition 2a for the underlayer is cured in a nitrogen-purged environment or in the atmosphere. In this way, as shown in FIG. 4B, the base layer 2 of the present embodiment is formed. Examples of the ionizing radiation to irradiate the composition 2a for the base layer include an ultrahigh pressure mercury lamp, a xenon lamp, a UV-LED, and the like, and are appropriately selected from among them according to the irradiation wavelength and the irradiation intensity. Further, the irradiation energy of ionizing radiation is, for example, about 230 mJ / cm ² when irradiating ultraviolet light in a nitrogen-purged environment. The above-mentioned "nitrogen-purged environment" means an environment in which the nitrogen concentration is higher than the nitrogen concentration in the atmosphere. Further, the above-mentioned "atmosphere" means an environment where the nitrogen concentration is the same as or lower than the nitrogen concentration in the atmosphere.

Next, as shown in FIG. 4C, the above-mentioned silver nanoparticle dispersion liquid 4a is placed on the base layer 2, for example, # 3 to so that the wet thickness of the silver nanoparticle dispersion liquid 4a is 6 μm to 23 μm. Apply using a # 10 bar coater.
Next, as shown in FIG. 4D, the above-mentioned composition for overcoat layer 3a is placed on the silver nanoparticle dispersion liquid 4a so that the thickness of the composition for overcoat layer 3a is, for example, 1 μm to 7 μm. Apply to the skin using a bar coater. Here, after the silver nanoparticle dispersion liquid 4a applied on the base layer 2 is dried to form a silver nanoparticle layer (not shown), the above-mentioned composition 3a for an overcoat layer is applied, for example, to an overcoat layer. The composition 3a may be applied using a bar coater so that the thickness of the composition 3a is 1 μm to 7 μm. However, when the composition 3a for an overcoat layer is applied after forming a silver nanoparticle layer (not shown), The silver nanoparticle layer (not shown) may be scratched. Therefore, in the present embodiment, it is preferable to apply the composition for the overcoat layer 3a on the silver nanoparticle dispersion liquid 4a before the solvent contained in the silver nanoparticle dispersion liquid 4a evaporates. Specifically, the composition 3a for the overcoat layer is placed on the silver nanoparticles dispersion liquid 4a in a state where 50% or more of the solvent contained in the silver nanoparticles dispersion liquid 4a remains in the silver nanoparticles dispersion liquid 4a. It is preferable to apply it to. The details of the method will be described later.

Next, the composition 3a for an overcoat layer applied on the silver nanoparticle dispersion liquid 4a is placed in an environment of, for example, 90 ° C. for 60 seconds to dry.
Finally, the overcoat layer 3 is formed by irradiating the overcoat layer composition 3a with ionizing radiation or the like to cure the overcoat layer composition 3a. The overcoat layer 3 is formed by integrating the silver nanoparticles dispersion 4a and the composition 3a for the overcoat layer, and the ionizing radiation irradiating the composition 3a for the overcoat layer is, for example, Examples thereof include ultra-high pressure mercury lamps, xenon lamps, UV-LEDs, etc., which are appropriately selected according to the irradiation wavelength and irradiation intensity. Further, the irradiation energy of ionizing radiation is, for example, about 230 mJ / cm ² when irradiating ultraviolet light in a nitrogen-purged environment. In addition, surface hardening of the ionizing radiation irradiation site is promoted by performing nitrogen purging.
In this way, the silver nanoparticle laminate 5 shown in FIG. 4 (e) is manufactured.
In the above-mentioned manufacturing process, a case where an appropriately prepared coating liquid is applied using, for example, a bar coater has been described, but the present invention is not limited thereto. For example, it may be applied by using a known coating means such as a roll coater, a gravure coater, a micro gravure coater, a die coater, and a dip coater.

In the present embodiment, as described above, the composition 3a for the overcoat layer may be applied onto the silver nanoparticle dispersion 4a before the silver nanoparticle dispersion 4a dries (in a wet state). An example of the method is shown in FIGS. 5 and 6.
FIG. 5 shows two coating nozzles (pre-coating nozzle and post-coating coating) in which a silver nanoparticle-containing composition (silver nanoparticle dispersion liquid) 4a and an overcoat layer composition 3a are separately provided. The method of coating by ejecting from each of the work nozzles) is shown. More specifically, the two coating liquids of the silver nanoparticle dispersion liquid 4a and the composition 3a for the overcoat layer are two single-nozzle die nozzle coaters installed at intervals as shown in FIG. 5, that is, for precoating. The thickness of the silver nanoparticle dispersion liquid 4a is 300 nm to 500 nm on the base film 13 by the coating head 10 and the coating head 11 for post-coating, and the thickness of the composition 3a for the overcoat layer is about 10 μm. It is applied so that it becomes. Then, for example, after drying at 90 ° C. in an oven on the same line, the light from the ultraviolet lamp is exposed at 240 mJ / cm ² . The "base film 13" means a film containing the base material 1 or a film containing the base material 1 and the base layer 2.

In this way, the composition 3a for the overcoat layer is cured to produce the above-mentioned silver nanoparticle laminate 5. The manufactured silver nanoparticle laminate 5 may be finally wound up. Further, in the method shown in FIG. 5, even if the pass roll 14 and the back roll 15 are provided in order to continuously form a laminate containing the silver nanoparticles-containing composition 4a and the composition for the overcoat layer 3a. good.

FIG. 6 shows a method of discharging and coating the silver nanoparticles-containing composition 4a and the overcoat layer composition 3a from two separately provided coating nozzles, as in FIG. 5. The method shown in FIG. 6 is the same as the method shown in FIG. 5 except that one double nozzle die nozzle coater, that is, the double nozzle type coating head 12 is used. Therefore, the detailed description thereof will be omitted here.

The present invention can solve the following problems by applying the composition 3a for an overcoat layer onto the silver nanoparticle dispersion 4a before the silver nanoparticle dispersion 4a dries (in a wet state). ..
When silver compounds, which are the raw materials for silver, are decomposed to produce silver nanoparticles, when they are used with an alkyldiamine having a primary amine and a tertiary amine intervening, good dispersibility is maintained in an organic solvent such as toluene. However, when this dispersion is applied and dried, its strength is so low that it can be peeled off just by rubbing it with a finger. Just touching the coating roll can cause scratches.

Regarding this point, in the above-mentioned production method according to the present embodiment, two coating nozzles in which the silver nanoparticles-containing composition 4a and the overcoat layer composition 3a are separately provided in a wet state are used. , Simultaneous multi-layer coating can be applied on the base film 13. More specifically, the silver nanoparticle laminate 5 is formed by continuously installing two single-nozzle die nozzle coaters having a constant curvature or installing one double nozzle coater. In this case, after the silver nanoparticles-containing composition 4a is applied, the composition for the overcoat layer 3a can be applied without touching anything. Therefore, when UV irradiation is performed with a high-pressure mercury lamp or the like after drying, the film strength is high. It was possible to obtain a silver nanoparticle laminate 5 having strong material adhesion.

Therefore, in the above-mentioned production method according to the present embodiment, the silver nanoparticles 4 are sufficiently dispersed during the production process and storage of the silver nanoparticles-containing composition 4a, and their aggregation is prevented. When the silver nanoparticles 4 are formed together with the silver nanoparticles 4, the film strength and the adhesion to the substrate are good, and the coating film color can be changed according to the purpose. A body 5 and a method for producing the same can be provided.

Hereinafter, the production of each silver nanoparticle laminate 5 shown in FIGS. 2 (a) to 2 (c) and FIGS. 3 (a) to 3 (b) will be specifically described.
In the case of producing the silver nanoparticle laminate 5 shown in FIG. 2A, that is, the silver nanoparticle laminate 5 according to the first embodiment, for example, in an environment where the composition 2a for an underlayer is purged with nitrogen or An overcoat layer composition 3a that is cured in the air and contains a pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer and a dipentaerythritol pentaacrylate succinic acid modified product may be used. Here, the above-mentioned pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer is not essential.

Further, in the case of producing the silver nanoparticle laminate 5 shown in FIG. 2B, that is, the silver nanoparticle laminate 5 according to the first modification of the first embodiment, for example, the composition for the base layer 2a 3a for an overcoat layer may be used, which is cured in the air and contains pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer.
Further, in the case of producing the silver nanoparticle laminate 5 shown in FIG. 2C, that is, the silver nanoparticle laminate 5 according to the second modification of the first embodiment, for example, the composition 2a for an underlayer is produced. 3a for an overcoat layer may be used, which is cured in the air and contains a pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer and a dipentaerythritol pentaacrylate phthalic acid modified product. Here, the above-mentioned pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer is not essential.

Further, in the case of producing the silver nanoparticle laminate 5 shown in FIG. 3A, that is, the silver nanoparticle laminate 5 according to the second embodiment, for example, an environment in which the composition 2a for the underlayer is purged with nitrogen. An overcoat layer composition 3a that is cured underneath and contains pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer may be used.
Further, in the case of producing the silver nanoparticle laminate 5 shown in FIG. 3 (b), that is, the silver nanoparticle laminate 5 according to the first modification of the second embodiment, for example, the composition for the underlayer 2a 3a for an overcoat layer may be used, which is cured in an environment purged with nitrogen and contains a pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer and a dipentaerythritol pentaacrylate phthalic acid modified product. Here, the above-mentioned pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer is not essential.

(Construction of other silver nanoparticle laminate 5)
In the first embodiment and its modifications, and in the second embodiment and its modifications, the base material 1, the base layer 2 formed on the base material 1, and the silver nanoparticles 4 formed on the base layer 2 are formed. Although the silver nanoparticle laminate 5 provided with the contained overcoat layer 3 has been described, the present invention is not limited thereto. For example, it may be a silver nanoparticle laminate (not shown) having a base material 1 and an overcoat layer 3 formed on the base material 1 and containing silver nanoparticles 4. That is, the base layer 2 is not an indispensable configuration in the silver nanoparticle laminate exhibiting various colors. Even in the case of the silver nanoparticle laminate not including the base layer 2, the color of the silver nanoparticle laminate can be variously changed as shown in Examples described later.
Further, the silver nanoparticle laminate 5 according to the present embodiment may be provided with, for example, a functional layer having various functions above or below the overcoat layer 3.

(Manufacturing process of other silver nanoparticle laminate 5)
The manufacturing process of the silver nanoparticle laminate not including the base layer 2 is the same as the manufacturing process of the silver nanoparticle laminate 5 including the base layer 2 described above, except that the step of forming the base layer 2 is omitted. .. Therefore, the detailed description thereof will be omitted here.

(Coloring mechanism)
The details of the coloration principle (mechanism) in this embodiment have not been clarified, but it is considered that the distribution of silver nanoparticles 4 has an influence. Hereinafter, this principle will be described with reference to FIGS. 7 to 10.
FIG. 7 schematically shows the principle of coloration when the base layer 2 is cured without nitrogen purging, that is, when the silver nanoparticles 4 are dispersed in the overcoat layer 3. It is a conceptual diagram shown. FIG. 7A is a diagram showing a dispersed state of the silver nanoparticles 4 in the first embodiment, and is a diagram corresponding to FIG. 2A. Further, FIG. 7B is a diagram showing a dispersed state of the silver nanoparticles 4 in the first modification of the first embodiment, and is a diagram corresponding to FIG. 2B. Further, FIG. 3 (c) is a diagram showing a dispersed state of the silver nanoparticles 4 in the second modification of the first embodiment, and is a diagram corresponding to FIG. 2 (c).

Further, FIG. 8 shows the absorption spectra of each silver nanoparticle laminate 5 corresponding to FIGS. 7 (a) to 7 (c). In FIG. 8, the horizontal axis indicates the wavelength and the vertical axis indicates the absorbance.
As shown in FIG. 7A, when the silver nanoparticles 4 are monodispersed in the overcoat layer 3, that is, when the silver nanoparticles 4 have high dispersibility (type I), the silver nanoparticles 4 A single surface plasmon resonance becomes dominant. Therefore, as shown in FIG. 8, the silver nanoparticle laminate 5 exhibits "yellow" due to the surface plasmon resonance.

Further, as shown in FIG. 7B, when a part of the silver nanoparticles 4 is aggregated in the overcoat layer 3 (type II), silver is formed by plasmon coupling between the silver nanoparticles 4. The absorption wavelength of the nanoparticles 4 shifts to the long wavelength side. Therefore, the silver nanoparticle laminate 5 exhibits an “orange color” as shown in FIG.
Further, as shown in FIG. 7 (c), when most of the silver nanoparticles 4 are aggregated in the overcoat layer 3 (type III), the effect of plasmon coupling between the silver nanoparticles 4 is effective. It becomes more remarkable, and the absorption wavelength of the silver nanoparticles 4 shifts to the longer wavelength side. Therefore, as shown in FIG. 8, the silver nanoparticle laminate 5 exhibits "reddish purple".

Here, although the change in the dispersibility of the silver nanoparticles 4 in the overcoat layer 3 is not clear, when the undercoat layer 2 is cured in the air (without nitrogen purging), the undercoat layer 2 is cured. Insufficient, the resin constituting the base layer 2 (composition for the base layer 2a) is eluted in the overcoat layer 3 (composition for the overcoat layer 3a), and the dispersibility of the silver nanoparticles 4 is changed. It is thought that it was.

FIG. 9 shows a case where the base layer 2 is cured in an environment where the base layer 2 is purged with nitrogen, and the silver nanoparticles 4 are dispersed in the overcoat layer 3 and the silver nanoparticles 4 are the base layer 2 and the overcoat layer. It is a conceptual diagram schematically showing the principle of color development in the case of agglomeration so as to be laminated along the interface with 3. FIG. 9A is a diagram showing a dispersed state of the silver nanoparticles 4 in the first embodiment, and is a diagram corresponding to FIG. 2A. Further, FIG. 9B is a diagram showing an aggregated state of the silver nanoparticles 4 in the second embodiment, and is a diagram corresponding to FIG. 3A. Further, FIG. 9 (c) is a diagram showing an aggregated state of the silver nanoparticles 4 in the first modification of the second embodiment, and is a diagram corresponding to FIG. 3 (b).

Further, FIG. 10 shows the absorption spectra of each silver nanoparticle laminate 5 corresponding to FIGS. 9 (a) to 9 (c). In FIG. 10, the horizontal axis indicates the wavelength and the vertical axis indicates the absorbance.
As shown in FIG. 9A, when the silver nanoparticles 4 are monodispersed in the overcoat layer 3, that is, when the silver nanoparticles 4 have high dispersibility (type IV), the silver nanoparticles 4 A single surface plasmon resonance becomes dominant. Therefore, as shown in FIG. 10, the silver nanoparticle laminate 5 exhibits "yellow" due to the surface plasmon resonance.

Further, as shown in FIG. 9B, when most of the silver nanoparticles 4 are aggregated near the interface between the base layer 2 and the overcoat layer 3 (type V), the silver nanoparticles 4 are interleaved with each other. The absorption wavelength of the silver nanoparticles 4 is shifted to the long wavelength side by the plasmon coupling. Therefore, as shown in FIG. 10, the silver nanoparticle laminate 5 exhibits "reddish purple".
Further, as shown in FIG. 9C, when most of the silver nanoparticles 4 are further aggregated in the overcoat layer 3 (type VI), the effect of plasmon coupling between the silver nanoparticles 4 is effective. Becomes more prominent, and the absorption wavelength of the silver nanoparticles 4 shifts to the longer wavelength side. Therefore, the silver nanoparticle laminate 5 exhibits "purple" as shown in FIG.

(Effect of this embodiment)
(1) The silver nanoparticle laminate 5 according to the present embodiment includes an undercoat layer 2 and an overcoat layer 3 formed on the undercoat layer 2, and the overcoat layer 3 is at least one in the molecule. At least one of a compound having the above urethane bond and two or more polymerizable unsaturated double bonds and a compound having at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule. And silver nanoparticles 4, and the silver nanoparticles 4 are dispersed in the overcoat layer 3.
With such a configuration, it is possible to change the maximum absorption wavelength of the silver nanoparticles 4, and the color variation exhibited by the silver nanoparticles laminate 5 increases.

(2) Further, the silver nanoparticle laminate 5 according to the present embodiment includes a base layer 2 and an overcoat layer 3 formed on the base layer 2, and the overcoat layer 3 is at least in the molecule. Compounds having one or more urethane bonds and two or more polymerizable unsaturated double bonds and compounds having at least one or more carboxy groups and one or more polymerizable unsaturated double bonds in the molecule. It contains at least one and silver nanoparticles 4, and the silver nanoparticles 4 are aggregated in layers along the interface between the base layer 2 and the overcoat layer 3.
With such a configuration, it is possible to change the maximum absorption wavelength of the silver nanoparticles 4, and the color variation exhibited by the silver nanoparticles laminate 5 increases.

(3) Further, the surface of the silver nanoparticles 4 contained in the silver nanoparticles laminate 5 according to the present embodiment is covered with a plurality of protective molecules, and the surface of the plurality of protective molecules covering the silver nanoparticles 4 is covered. The most abundant molecule may be an alkyldiamine having a primary amino group and a tertiary amino group.
With such a configuration, when the silver nanoparticles 4 are dispersed in a non-polar solvent such as toluene, the dispersibility is good.
(4) Further, the average primary particle diameter (D50) of the silver nanoparticles 4 contained in the silver nanoparticles laminate 5 according to the present embodiment may be in the range of 1 nm or more and 30 nm or less.
With such a configuration, when the silver nanoparticles 4 are dispersed in a solvent, the dispersibility is further improved.

(5) Further, the overcoat layer 3 contained in the silver nanoparticles laminate 5 according to the present embodiment has at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule. It may contain a resin having a three-dimensional crosslinked structure obtained from the compound and a compound having at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule.
With such a configuration, the mechanical strength of the silver nanoparticle laminate 5 can be increased.
(6) Further, the base layer 2 contained in the silver nanoparticle laminate 5 according to the present embodiment may contain a compound having at least two or more polymerizable unsaturated double bonds.
With such a configuration, it is possible to change the maximum absorption wavelength of the silver nanoparticles 4, and the color variation exhibited by the silver nanoparticles laminate 5 is further increased.

(7) Further, the compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule contained in the silver nanoparticles laminate 5 according to the present embodiment is (meth). ) It is an acrylic acid ester compound and may contain urethane acrylate.
With such a configuration, it is possible to change the maximum absorption wavelength of the silver nanoparticles 4, and the color variation exhibited by the silver nanoparticles laminate 5 is further increased.

(8) The method for producing the silver nanoparticles laminate 5 according to the present embodiment includes a step of applying a silver nanoparticles-containing composition 4a containing silver nanoparticles 4 and a dispersion medium on the base layer 2 and intramolecular. A compound having at least one urethane bond and two or more polymerizable unsaturated double bonds and having at least one or more carboxy groups and one or more polymerizable unsaturated double bonds in the molecule. A step of applying a composition 3a for an overcoat layer containing at least one of the compounds, a compound that generates a polymerization initiation species by ionizing radiation, and a solvent onto the silver nanoparticles-containing composition 4a coated on the base layer 2. After the composition 3a for the overcoat layer is dried, the composition 3a for the overcoat layer is irradiated with ionizing radiation to cure the composition 3a for the overcoat layer to form the overcoat layer 3. The overcoat layer 3 is formed by integrating the silver nanoparticle dispersion liquid 4a and the composition for the overcoat layer 3a.
With such a configuration, it is possible to manufacture a silver nanoparticle laminate 5 capable of exhibiting a color.

(9) Further, in the method for producing the silver nanoparticles laminate 5 according to the present embodiment, the composition 3a for an overcoat layer has at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule. It may contain both a compound having a double bond and a compound having at least one or more carboxy groups and one or more polymerizable unsaturated double bonds in the molecule.
With such a configuration, the silver nanoparticle laminate 5 having increased mechanical strength can be manufactured.
(10) Further, in the method for producing the silver nanoparticle laminate 5 according to the present embodiment, the silver nanoparticle-containing composition 4a and the overcoat layer composition 3a may be coated in a wet state, respectively.
With such a configuration, it is possible to manufacture a silver nanoparticle laminate 5 capable of exhibiting a uniform color.

(11) Further, in the method for producing the silver nanoparticles laminate 5 according to the present embodiment, after the step of applying the silver nanoparticles-containing composition 4a and before the step of applying the composition for the overcoat layer 3a. Further having a step of drying the silver nanoparticle-containing composition 4a applied on the base layer 2 to form a silver nanoparticle layer, and in a step of applying the overcoat layer composition 3a, on the base layer 2. The composition 3a for an overcoat layer may be applied onto the formed silver nanoparticle layer. Even with such a configuration, the silver nanoparticle laminate 5 capable of exhibiting color can be produced.

(12) Further, in the method for producing the silver nanoparticle laminate 5 according to the present embodiment, the silver nanoparticle-containing composition 4a and the overcoat layer composition 3a are separately provided from two coating nozzles, respectively. It may be discharged and coated.
With such a configuration, it is possible to manufacture a silver nanoparticle laminate 5 capable of exhibiting a more uniform color.

(13) Further, in the method for producing the silver nanoparticle laminate 5 according to the present embodiment, for the base layer applied on the base layer 1 before the step of applying the silver nanoparticle-containing composition 4a on the base layer 2. A step of curing the composition 2a in an environment purged with nitrogen to form a base layer 2, or a step of curing the composition 2a for a base layer applied on the base material 1 in the air to form a base layer 2. May further have.
With such a configuration, the silver nanoparticle laminate 5 with increased color variations can be manufactured.

(14) Further, in the method for producing the silver nanoparticle laminate 5 according to the present embodiment, the solvent may be methyl ethyl ketone.
With such a configuration, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule and at least one carboxy group and one or more carboxy groups in the molecule. A compound having a polymerizable unsaturated double bond can be easily dissolved.
(15) Further, in the method for producing the silver nanoparticles laminate 5 according to the present embodiment, the silver nanoparticles-containing composition 4a contains silver nanoparticles 4 in a range of 2% by mass or more and 20% by mass or less with respect to the dispersion medium. It may be a dispersion liquid contained therein.
With such a configuration, it is possible to manufacture the silver nanoparticle laminate 5 having improved dispersibility of the silver nanoparticles 4.

(16) Further, in the method for producing a silver nanoparticle laminate 5 according to the present embodiment, the base layer 2 may contain a compound having at least two or more polymerizable unsaturated double bonds.
With such a configuration, the silver nanoparticle laminate 5 with increased color variations can be manufactured.
(17) Further, in the method for producing the silver nanoparticles laminate 5 according to the present embodiment, the compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule is (17). It is a meta) acrylic acid ester compound and may contain urethane acrylate.
With such a configuration, the silver nanoparticle laminate 5 with increased color variations can be manufactured.

(18) The method for coloring the silver nanoparticle laminate 5 according to the present embodiment covers at least a part of the silver nanoparticles 4 of the silver nanoparticles laminate 5 provided with the overcoat layer 3 containing the silver nanoparticles 4. The absorption wavelength of the silver nanoparticles 4 is changed by dispersing the particles in the coat layer 3 and changing the distance between the dispersed silver nanoparticles 4.
With such a configuration, the maximum absorption wavelength of the silver nanoparticles 4 can be changed, and various colors can be developed in the silver nanoparticles laminate 5.

(19) The method for coloring the silver nanoparticles laminate 5 according to the present embodiment is a method of coloring silver nanoparticles having a base layer 2 and an overcoat layer 3 formed on the base layer 2 and containing silver nanoparticles 4. At least a part of the silver nanoparticles 4 of the laminate 5 is aggregated in a layered manner along the interface between the base layer 2 and the overcoat layer 3, and the distance between the aggregated silver nanoparticles 4 is changed to change the distance between the aggregated silver nanoparticles 4. The absorption wavelength of the particles 4 is changed.
With such a configuration, the maximum absorption wavelength of the silver nanoparticles 4 can be changed, and various colors can be developed in the silver nanoparticles laminate 5.
Hereinafter, as the first to third embodiments, evaluations of a method for producing silver nanoparticles, dispersibility in a solvent, preparation of a coating film for forming a coating film, physical properties of a coating film, and the like are shown. Is not limited to these.

(First Example)
[Example 1]
[Silver oxalate synthesis]
Add 60 mL of distilled water to 9.92 g of oxalic acid dihydrate (Kanto Kagaku Co., Ltd.), dissolve it while heating, and stir in an oil bath at 110 ° C. to add 20 mL to 26.7 g of silver nitrate (Kanto Kagaku Co., Ltd.). Distilled water was added, and the solution was added while heating, and heating and stirring were continued for 1 hour. The precipitated silver oxalate was recovered by natural filtration, further filtered and washed with 200 mL of hot water and 50 mL of methanol (Kanto Chemical Co., Inc.), and then dried at room temperature while reducing the pressure in a light-shielding desiccator. The yield of silver oxalate thus obtained was 21.6 g (yield 90.4%).

[Synthesis of silver nanoparticles 4]
To 3.26 g of N, N-diethyl-1,3-diaminopropane (Tokyo Kasei Co., Ltd.) and 0.13 g of oleic acid, 1.90 g of silver oxalate obtained in the above step was added, and the temperature was 110 ° C. It was heated and stirred in an oil bath. Carbon dioxide foaming occurred within 1 minute and turned into a brown suspension after a few minutes. After heating for 5 minutes, 30 mL of methanol was added to the place where the mixture was cooled, and the precipitate obtained by centrifugation was air-dried to obtain 1.48 g of a blue solid (silver standard yield 97.0).

When the obtained silver nanoparticles 4 were observed in S-TEM mode (acceleration voltage 30 kV) using a scanning electron microscope (Hitachi High Technology, SEM S-4800), they were spherical with a particle diameter of about 5 to 20 nm. Particles were observed. The result is shown in FIG. More specifically, FIG. 11 shows a scanning electron microscope image of the silver nanoparticles 4 observed after the toluene solvent dispersion of the silver nanoparticles 4 obtained in Example 1 was dropped on a substrate (copper mesh microgrid) and dried. Is.

Next, the dispersibility of the obtained silver nanoparticles 4 in a solvent was evaluated. As a result, it was well dispersed in a mixed solvent of toluene, tarpineol C (Nippon Terpen Chemical Co., Ltd.), dihydroterpineol (Nippon Terpen Chemical Co., Ltd.), and hexane containing these as the main component. Dynamic light scattering particle size measurement of the toluene dispersion solution (Nanotrac UPA-EX150, Nikkiso Co., Ltd.) revealed that the obtained coated silver nanoparticles were well dispersed with an average particle diameter of 15 nm. The results are shown in FIG. The solid line shown in FIG. 12 indicates the cumulative frequency (%).

[Formation of silver nanoparticle laminate 5]
0.2 g of the blue solid obtained in the above step was dispersed in 4.0 g of toluene (Kanto Chemical Co., Inc.) and stirred well to prepare a coating liquid, that is, a silver nanoparticle-containing composition 4a.
The coating liquid containing the silver nanoparticles 4 obtained in the above step was applied to PET as the base material 1 using a # 3 bar coater, and then the solvent was volatilized in an oven at 90 ° C. for 1 minute.

[Formation of overcoat layer 3]
Next, 9.5 g of urethane acrylate oligomer UA-306I (Kyoeisha Chemical Co., Ltd.) and 0.50 g of Irgacure 184 (BASF) as an initiator dissolved in 12.0 g of methyl ethyl ketone (A) and urethane acrylate oligomer UA-. 306I (Kyoeisha Chemical Co., Ltd.): DPE6A-MP (dipentaerythritol pentaacrylate phthalic acid modified product, Kyoeisha Chemical Co., Ltd.) = 7.6 g: 1.9 g mixture, Irgacure 184 (BASF) 0.50 g as an initiator (B) dissolved in 12.0 g of methyl ethyl ketone was applied on a silver nanoparticles layer containing silver nanoparticles 4 coated and dried on the above-mentioned PET film, respectively, and dried with a # 10 bar coater. After that, each coating film is put in a purge box and filled with nitrogen gas, and then exposed at 180 mJ / cm ² with a UV conveyor (Heraeus, CV-110Q-G type, light source: Light Hammer 10MerkII, H bulb). , The above "A" and "B" were cured to form the overcoat layer 3. Both of the silver nanoparticle laminates (hereinafter, also simply referred to as "cured film") 5 thus obtained show metallic luster, but here, based on the transmitted light of the cured film of "A" (color is magenta), The cured film transmitted light of "B" containing a carboxy group-containing monomer exhibited a bluish purple color and showed a different absorption wavelength. Table 1 is a table showing the maximum absorption wavelength (λ _MAX ) of the silver nanoparticle laminate 5 obtained in Examples 1 to 7, respectively. The measurement of λ _MAX was carried out by Shimadzu Corporation, an ultraviolet-visible spectrophotometer UV-2600, and a transmission mode.

(Example 2)
Of the "B" (composition for overcoat layer 3a) used in Example 1, instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.), PE3A-MP (pentaerythritol triacrylate phthalic acid modified product, Kyoeisha Co., Ltd.) When a cured film layer (overcoat layer 3) was obtained by operating in the same manner as in Example 1 except that the mixture (C) using (Chemical Co., Ltd.) was used, absorption different from that of the transmitted light of the cured film of "A" was obtained. The wavelength is shown. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 2 is shown in Table 1.

(Example 3)
Of the "B" (composition 3a for overcoat layer) used in Example 1, instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.), DPE6A-MS (dipentaerythritol pentaacrylate succinic acid modified product, Kyoeisha Chemical Co., Ltd.) When a cured film layer (overcoat layer 3) was obtained by operating in the same manner as in Example 1 except that the mixture (D) using 1.9 g was used, the cured film of "A" had light. It showed a different absorption wavelength from. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 3 is shown in Table 1.

(Example 4)
Of the "B" (composition 3a for overcoat layer) used in Example 1, instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.), PE3A-MS (dipentaerythritol triacrylate succinic acid modified product, Kyoeisha Chemical Co., Ltd.) When a cured film layer (overcoat layer 3) was obtained by operating in the same manner as in Example 1 except that the mixture (E) using 1.9 g was used, the cured film of "A" had light. It showed a different absorption wavelength from. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 4 is shown in Table 1.

(Example 5)
Of "B" (composition 3a for overcoat layer) used in Example 1, instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.), HOA-MPL (N) (2-acryloyloxyethyl phthal) Acid, Kyoeisha Kagaku Co., Ltd.) When a cured film layer (overcoat layer 3) was obtained by the same operation as in Example 1 except that the mixture (F) using 1.9 g was used, the cured film of "A" was obtained. It showed an absorption wavelength different from that of transmitted light. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 5 is shown in Table 1.

(Example 6)
Of the "B" (composition 3a for overcoat layer) used in Example 1, instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.), light acrylate HOA-HH (N) (2-acryloyloxy). Ethylhexahydrophthalic acid, Kyoeisha Kagaku Co., Ltd.) When a cured film layer (overcoat layer 3) was obtained by the same operation as in Example 1 except that the mixture (G) using 1.9 g was used, "A" was obtained. It showed an absorption wavelength different from that of the transmitted light of the cured film. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 6 is shown in Table 1.

(Example 7)
In "B" (composition 3a for overcoat layer) used in Example 1, instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.), NK ester SA (2-methacrylloyloxyethyl-succinic acid, Kyoeisha Chemical Co., Ltd.) When a cured film layer (overcoat layer 3) was obtained by operating in the same manner as in Example 1 except that the mixture (H) using 1.9 g was used, the cured film of "A" had light. It showed a different absorption wavelength from. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 7 is shown in Table 1.

(Example 8)
MEK12 in a mixture of urethane acrylate compound (UA-1280MK (manufactured by Shin-Nakamura Chemical Co., Ltd.): UV7000B (manufactured by Nippon Synthetic Chemical Co., Ltd.) = 25.40 g: 8.63 g) on PET used as a base material in Example 1. After applying .96 g and 0.34 g of the photopolymerization initiator EsacureONE to and dissolved the base material coating liquid (composition 2a for the base layer) on a 75 μm thick PET film (Lumirror T60, manufactured by Toray Co., Ltd.) using a # 50 bar coater. , 90 ° C. dried, exposed and cured at 240 mJ / cm ² with a UV conveyor (Hereus, CV-110Q-G type, light source: light hammer 10MerkII, H valve, hereinafter UV irradiation) to form a UV-cured base layer. .. When a silver nanoparticle laminate was obtained by the same operation as in Example 1 except that the UV curing base layer was used, the transmitted light of the cured films of "A" and "B" showed different absorption wavelengths. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Example 8 is shown in Table 1.

(Comparative Example 1)
Of the "B" (composition for overcoat layer 3a) used in Example 1, 1.9 g of light acrylate POB-A (Kyoeisha Chemical Co., Ltd.) was used instead of 1.9 g of DPE6A-MP (Kyoeisha Chemical Co., Ltd.). When the cured film layer (overcoat layer 3) was obtained by the same operation as in Example 1 except that the mixture (I) used was used, the transmitted light of the cured film of "A" and the cured film of "I" were obtained. Both transmitted lights were magenta and showed similar absorption wavelengths. The maximum absorption wavelength of the silver nanoparticle laminate obtained in Comparative Example 1 is shown in Table 1.
The structures of the monomers used in Examples 1 to 8 and Comparative Example 1 are shown in FIG.
From the results of Examples 1 to 8 and Comparative Example 1 shown in Table 1, the overcoat layer 3 contains a compound having at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule. It can be seen that the absorption wavelength of the silver nanoparticle laminate 5 is significantly shifted.
From the results of Example 8 shown in Table 1, it can be seen that the base material 1 does not affect the absorption wavelength of the silver nanoparticle laminate 5.

(Second Example)
(Example 9)
The composition 2a for the underlayer used in Example 8 was dried in the air, exposed and cured to obtain a UV-curable underlayer (underlayer) 2. Further, the overcoat layer 3 was formed of the same composition 3a for the overcoat layer as "D" used in Example 3. Other than that, it was the same as in Example 8. The maximum absorption wavelength of the silver nanoparticle laminate 5 obtained in Example 9 is shown in Table 2.
Note that FIG. 14A is a scanning electron microscope image of the silver nanoparticles 4 contained in the overcoat layer 3 constituting the silver nanoparticles laminate 5 of Example 9. Note that FIG. 14 (b) is a scanning electron microscope image obtained by enlarging a part of FIG. 14 (a).

(Example 10)
The composition 2a for the underlayer used in Example 8 was dried in the air, exposed and cured to obtain a UV-curable underlayer (underlayer) 2. Further, the overcoat layer 3 was formed of the same composition 3a for the overcoat layer as "A" used in Example 1. Other than that, it was the same as in Example 8. The maximum absorption wavelength of the silver nanoparticle laminate 5 obtained in Example 10 is shown in Table 2.
Note that FIG. 15A is a scanning electron microscope image of the silver nanoparticles 4 contained in the overcoat layer 3 constituting the silver nanoparticles laminate 5 of Example 10. Note that FIG. 15B is a scanning electron microscope image obtained by enlarging a part of FIG. 15A.

(Example 11)
The composition 2a for the underlayer used in Example 8 was dried in the air, exposed and cured to obtain a UV-curable underlayer (underlayer) 2. Further, the overcoat layer 3 was formed of the same composition 3a for the overcoat layer as "B" used in Example 1. Other than that, it was the same as in Example 8. The maximum absorption wavelength of the silver nanoparticle laminate 5 obtained in Example 11 is shown in Table 2.
Note that FIG. 16A is a scanning electron microscope image of the silver nanoparticles 4 contained in the overcoat layer 3 constituting the silver nanoparticles laminate 5 of Example 11. Note that FIG. 16B is a scanning electron microscope image obtained by enlarging a part of FIG. 16A.

(Example 12)
The composition 2a for the underlayer used in Example 8 was dried in a nitrogen-purged environment, exposed and cured to obtain a UV-curable underlayer (underlayer) 2. Further, the overcoat layer 3 was formed of the same composition 3a for the overcoat layer as "D" used in Example 3. Other than that, it was the same as in Example 8. The maximum absorption wavelength of the silver nanoparticle laminate 5 obtained in Example 12 is shown in Table 2.
Note that FIG. 17A is a scanning electron microscope image of the silver nanoparticles 4 contained in the overcoat layer 3 constituting the silver nanoparticles laminate 5 of Example 12. Note that FIG. 17B is a scanning electron microscope image obtained by enlarging a part of FIG. 17A.

(Example 13)
The composition 2a for the underlayer used in Example 8 was dried in a nitrogen-purged environment, exposed and cured to obtain a UV-curable underlayer (underlayer) 2. Further, the overcoat layer 3 was formed of the same composition 3a for the overcoat layer as "A" used in Example 1. Other than that, it was the same as in Example 8. The maximum absorption wavelength of the silver nanoparticle laminate 5 obtained in Example 13 is shown in Table 2.
Note that FIG. 18A is a scanning electron microscope image of the silver nanoparticles 4 contained in the overcoat layer 3 constituting the silver nanoparticles laminate 5 of Example 13. Note that FIG. 18B is a scanning electron microscope image obtained by enlarging a part of FIG. 18A.

(Example 14)
The composition 2a for the underlayer used in Example 8 was dried in a nitrogen-purged environment, exposed and cured to obtain a UV-curable underlayer (underlayer) 2. Further, the overcoat layer 3 was formed of the same composition 3a for the overcoat layer as "B" used in Example 1. Other than that, it was the same as in Example 8. The maximum absorption wavelength of the silver nanoparticle laminate 5 obtained in Example 14 is shown in Table 2.
Note that FIG. 19A is a scanning electron microscope image of the silver nanoparticles 4 contained in the overcoat layer 3 constituting the silver nanoparticles laminate 5 of Example 14. Note that FIG. 19B is a scanning electron microscope image obtained by enlarging a part of FIG. 19A.
From the results of Examples 9 to 14 shown in Table 2, by changing the environment for forming the UV-curable base layer (base layer) 2 and changing the combination of the types of resins constituting the overcoat layer 3. It can be seen that the absorption wavelength of the silver nanoparticle laminate 5 is significantly shifted.

(Third Example)
(Example 15)
First, the composition containing silver nanoparticles (pre-coated silver layer) 4a was liquefied using the following materials.
・ Silver nanoparticles 1 part by mass ・ Toluene (manufactured by Kanto Chemical Co., Inc.) 20 parts by mass The composition for the overcoat layer (post-coating overcoat layer) 3a was liquefied using the following materials.
・ UA-306I (manufactured by Kyoeisha Chemical Co., Ltd.) 100 parts by mass ・ Irgacure 184 (manufactured by BASF) 5 parts by mass ・ MEK (manufactured by Kanto Chemical Co., Inc.) 122 parts by mass

The two obtained coating liquids were applied to a PET film (Lumirror T60, 75 μm thick, manufactured by Toray Co., Ltd.) with a silver layer of 300 to 500 nm using two single-nozzle die nozzle coaters installed at intervals as shown in FIG. , Apply to an overcoat layer of 10 μm, dry at 90 ° C in an oven on the same line, and then UV lamp (Hereus, CV-110Q-G type, light source: Light Hammer 10MerkII, H valve, hereinafter UV irradiation. ) Was exposed and cured at 240 mJ / cm ² , and the silver nanoparticle laminate (color-developing film) 5 was wound up.

Here, in FIG. 5, 10 is a coating nozzle for pre-coating (web tension method for thin film coating), 11 is a coating nozzle for post-coating (back roll method for thick film coating), and 13 is a base film. 3a indicates a silver nanoparticle dispersion liquid, and 4a indicates a composition for an overcoat layer. In the figure, the arrow indicates the traveling direction of the base film 13. The coating speed was 10 m / min.
The absorption spectrum of the obtained silver nanoparticle laminate 5 is shown in FIG. Table 3 shows the evaluation results such as the maximum value (λ _MAX ) of the absorption spectrum of the silver nanoparticle laminate 5.
This measurement was performed using Shimadzu Corporation, an ultraviolet-visible spectrophotometer UV-2600, and a transmission mode.

(Example 16)
A silver nanoparticle laminate 5 was obtained in the same manner as in Example 15 except that one double nozzle die nozzle coater shown in FIG. 6 was used instead of the two coating nozzles of Example 15. The absorption spectrum of the obtained silver nanoparticle laminate 5 was almost the same as that of Example 15. The evaluation results are shown in Table 3.

(Example 17)
UA-306I: 100 parts by mass of the post-coating overcoat layer composition 3a used in Example 15 UA-306I: dipentaerythritol pentaacrylate succinic acid modified product (DPE6A-MS, developed product, Kyoeisha Chemical Co., Ltd.) = The operation was carried out in the same manner as in Example 15 except that the setting was 80:20, to obtain a silver nanoparticle laminate 5. The absorption spectrum of the obtained silver nanoparticle laminate 5 is shown in FIG. The evaluation results are shown in Table 3.

(Example 18)
UA-306I: 100 parts by mass of the composition 3a for the post-coating overcoat layer used in Example 15 UA-306I: dipentaerythritol pentaacrylate phthalic acid modified product (DPE6A-MP, developed product, Kyoeisha Chemical Co., Ltd.) = The operation was carried out in the same manner as in Example 15 except that the setting was 80:20 to obtain a silver nanoparticle laminate 5. The absorption spectrum of the obtained silver nanoparticle laminate 5 is shown in FIG. The evaluation results are shown in Table 3.

(Example 19)
Instead of PET which is the base film 13 of Example 15, MEK12 is added to a mixture of urethane acrylate compound (UA-1280MK (manufactured by Shin-Nakamura Chemical Co., Ltd.): UV7000B (manufactured by Nippon Synthetic Chemical Co., Ltd.) = 25.40 g: 8.63 g). The composition 2a for the underlayer, which was dissolved by adding .96 g and 0.34 g of the photopolymerization initiator EsacureONE, was applied to PET (Lumilar T60, 75 μm thick, manufactured by Toray Co., Ltd.) with one single die nozzle coater, and then dried at 90 ° C. Then, the base film was exposed and cured at 240 mJ / cm ² by a UV conveyor (Heleus, CV-110Q-G type, light source: light hammer 10MerkII, H valve, hereinafter UV irradiation). A silver nanoparticle laminate 5 was obtained in the same manner as in Example 17 except that the value was 13. The absorption spectrum of the obtained silver nanoparticle laminate 5 is shown in FIG. The evaluation results are shown in Table 3.

(Example 20)
Dipentaerythritol pentaacrylate phthalic acid modified product (DPE6A-MS, developed product, Kyoeisha Chemical Co., Ltd.) instead of the dipentaerythritol pentaacrylate succinic acid modified product (DPE6A-MS, developed product, Kyoeisha Chemical Co., Ltd.) of the overcoat layer composition 3a used in Example 18. The silver nanoparticle laminate 5 was obtained in the same manner as in Example 19 except that MP, a developed product, and Kyoeisha Chemical Co., Ltd. were used. The absorption spectrum of the obtained silver nanoparticle laminate 5 is shown in FIG. The evaluation results are shown in Table 3.

(Comparative Example 2)
The silver nanoparticle-containing composition 4a of Example 15 was applied to PET (Lumilar T60, 75 μm thick, manufactured by Toray Co., Ltd.) with one single die nozzle coater, dried at 90 ° C., wound, and then silver nano. The composition 3a for an overcoat layer was applied onto a PET film on which a particle layer was formed with one single die nozzle coater, dried at 90 ° C., and dried on a UV conveyor (Heleus, CV-110Q-G type, light source). : Light hammer 10 MerckII, H valve, hereinafter UV irradiation) exposed and cured at 240 mJ / cm ² to obtain a silver nanoparticles laminate 5. The absorption spectrum of the silver nanoparticle laminate 5 thus obtained was almost the same as that of Example 15. The evaluation results are shown in Table 3.
Table 3 shows the evaluation results (appearance, steel wool test) of each of the silver nanoparticle laminates 5 obtained in Examples 15 to 20.

From the results of Examples 15 to 20 shown in Table 3, a silver nanoparticle-containing composition 4a and a composition for an overcoat layer were used using two single-nozzle die nozzle coaters or one double-nozzle die nozzle coater. When 3a is applied, the scratches on the silver nanoparticle layer generated in Comparative Example 2 can be reduced, and the scratch resistance of the silver nanoparticle laminate 5 can be enhanced.

(evaluation)
In Examples 15 to 20 and Comparative Example 2, the presence or absence of scratches on the silver layer was visually confirmed.
The scratch resistance (steel wool test) was visually evaluated for the presence or absence of scratches when making 10 round trips using # 0000 steel wool with a load of 500 g / cm ² and 250 g / cm ² . 500g load no scratches ◎, 250g load no scratches ○, scratches ×).

As described above, the silver nanoparticle laminate 5 containing the silver nanoparticles 4 in the present invention can produce a functional film having optical characteristics peculiar to the silver nanoparticles 4 and a coating film having a metallic luster, and can be used. The color can be changed according to.

1 ... Base material 2 ... Base layer 2a ... Composition for base layer 3 ... Overcoat layer 3a ... Composition for overcoat layer 4 ... Silver nanoparticles 4a ... Silver nanoparticles dispersion 5 ... Silver nanoparticles laminate 10 ... Destination Coating head for coating 11 ... Coating head for post-coating 12 ... Double nozzle type coating head 13 ... Base film 14 ... Pass roll 15 ... Back roll

Claims (16)

Underlayer and
The overcoat layer formed on the base layer is provided.
The overcoat layer is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group and one or more polymerizable groups in the molecule. It contains at least one of the compounds having an unsaturated double bond and silver nanoparticles.
The silver nanoparticles are dispersed in the overcoat layer, and the silver nanoparticles are dispersed in the overcoat layer .
In the overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one or more carboxy groups and one or more in the molecule. The total content with the compound having a polymerizable unsaturated double bond is in the range of 98% by mass or more and 99% by mass or less.
The content of the silver nanoparticles in the overcoat layer is in the range of 1% by mass or more and 2% by mass or less.
In the overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one or more carboxy groups and one or more in the molecule. The mass ratio with the compound having a polymerizable unsaturated double bond is in the range of 10: 0 to 6: 4.
A silver nanoparticle laminate characterized in that the average primary particle diameter (D50) of the silver nanoparticles is in the range of 1 nm or more and 30 nm or less . Underlayer and
The overcoat layer formed on the base layer is provided.
The overcoat layer is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group and one or more polymerizable groups in the molecule. It contains at least one of the compounds having an unsaturated double bond and silver nanoparticles.
The silver nanoparticles are aggregated in layers along the interface between the base layer and the overcoat layer .
In the overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one or more carboxy groups and one or more in the molecule. The total content with the compound having a polymerizable unsaturated double bond is in the range of 98% by mass or more and 99% by mass or less.
The content of the silver nanoparticles in the overcoat layer is in the range of 1% by mass or more and 2% by mass or less.
In the overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one or more carboxy groups and one or more in the molecule. The mass ratio with the compound having a polymerizable unsaturated double bond is in the range of 10: 0 to 6: 4.
A silver nanoparticle laminate characterized in that the average primary particle diameter (D50) of the silver nanoparticles is in the range of 1 nm or more and 30 nm or less . The surface of the silver nanoparticles is covered with a plurality of protective molecules, and the surface of the silver nanoparticles is covered with a plurality of protective molecules.
Claim 1 or claim 2 is characterized in that the most abundant molecule among the plurality of protected molecules covering the surface of the silver nanoparticles is an alkyldiamine having a primary amino group and a tertiary amino group. The silver nanoparticle laminate according to. The overcoat layer comprises a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one or more carboxy groups and one or more in the molecule. The silver nanoparticle laminate according to any one of claims 1 to 3 , which comprises a resin having a three-dimensional crosslinked structure obtained from a compound having a polymerizable unsaturated double bond. .. The silver nanoparticle laminate according to any one of claims 1 to 4 , wherein the underlayer contains a compound having at least two or more polymerizable unsaturated double bonds. The compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule is a (meth) acrylic acid ester compound, and is characterized by containing urethane acrylate. The silver nanoparticles laminate according to any one of claims 1 to 5 . The step of curing the composition for the underlayer applied on the substrate in a nitrogen-purged environment to form the underlayer, or the composition for the underlayer applied on the substrate is cured in the atmosphere to form the underlayer. And the process of forming
A step of applying a silver nanoparticle-containing composition containing silver nanoparticles and a dispersion medium onto the base layer, and a step of applying the composition.
Compounds having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule and at least one carboxy group and one or more polymerizable unsaturated double bonds in the molecule. A composition for an overcoat layer containing at least one of the compounds having the above, a compound that generates a polymerization initiation species by ionizing radiation, and a solvent is applied onto the silver nanoparticles-containing composition coated on the undercoat layer. Process and
After the composition for the overcoat layer is dried, the composition for the overcoat layer is irradiated with the ionizing radiation to cure the composition for the overcoat layer to form the overcoat layer. death,
In the composition for an overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The total content with the compound having one or more polymerizable unsaturated double bonds is in the range of 50% by mass or more and 95% by mass or less with respect to the total mass of the composition for the overcoat layer.
The content of the compound that generates the polymerization initiation species by the ionizing radiation in the composition for the overcoat layer is 0.5% by mass or more and 10% by mass or less with respect to the total solid content in the composition for the overcoat layer. Within range,
In the composition for an overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The mass ratio to the compound having one or more polymerizable unsaturated double bonds is in the range of 10: 0 to 6: 4.
The average primary particle diameter (D50) of the silver nanoparticles is in the range of 1 nm or more and 30 nm or less.
The silver nanoparticles-containing composition is a dispersion liquid containing the silver nanoparticles in a range of 2% by mass or more and 20% by mass or less with respect to the dispersion medium. Method. The composition for an overcoat layer includes a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The method for producing a silver nanoparticles laminate according to claim 7 , wherein the compound contains both compounds having two or more polymerizable unsaturated double bonds. The method for producing a silver nanoparticles laminate according to claim 7 or 8 , wherein the silver nanoparticles-containing composition and the overcoat layer composition are coated in a wet state, respectively. After the step of applying the silver nanoparticles-containing composition and before the step of applying the composition for the overcoat layer, the silver nanoparticles-containing composition applied on the base layer is dried to make silver nanoparticles. Further having a step of forming a particle layer,
The seventh or eighth aspect of the step of applying the composition for an overcoat layer is characterized in that the composition for an overcoat layer is applied onto the silver nanoparticles layer formed on the undercoat layer. The method for producing a laminate of silver nanoparticles according to the above. 7 . The method for producing a silver nanoparticle laminate according to claim 1. The method for producing a silver nanoparticles laminate according to any one of claims 7 to 11, wherein the solvent is methyl ethyl ketone. The production of the silver nanoparticles laminate according to any one of claims 7 to 12, wherein the underlayer contains a compound having at least two or more polymerizable unsaturated double bonds. Method. The compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule is a (meth) acrylic acid ester compound, and is characterized by containing urethane acrylate. 7. The method for producing a silver nanoparticles laminate according to any one of claims 13 to 3 . An underlayer that is a UV-curable underlayer formed by drying, exposing, and curing in the air, or an underlayer that is a UV-curable underlayer formed by drying, exposing, and curing in a nitrogen-purged environment. At least a part of the silver nanoparticles of the silver nanoparticles laminate formed on the base layer and provided with the overcoat layer containing the silver nanoparticles is dispersed in the overcoat layer, and the dispersed silver. By changing the distance between the nanoparticles, the absorption wavelength of the silver nanoparticles is changed , and
The composition for an overcoat layer for forming the overcoat layer is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule and at least one in the molecule. It contains at least one of the above compounds having a carboxy group and one or more polymerizable unsaturated double bonds, a compound that generates a polymerization initiation species by ionizing radiation, and a solvent.
In the composition for an overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The total content with the compound having one or more polymerizable unsaturated double bonds is in the range of 50% by mass or more and 95% by mass or less with respect to the total mass of the composition for the overcoat layer.
The content of the compound that generates the polymerization initiation species by the ionizing radiation in the composition for the overcoat layer is 0.5% by mass or more and 10% by mass or less with respect to the total solid content in the composition for the overcoat layer. Within range,
In the composition for an overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The mass ratio to the compound having one or more polymerizable unsaturated double bonds is in the range of 10: 0 to 6: 4.
The average primary particle diameter (D50) of the silver nanoparticles is in the range of 1 nm or more and 30 nm or less.
The silver nanoparticles-containing composition for dispersing the silver nanoparticles in the overcoat layer is a dispersion containing the silver nanoparticles in a range of 2% by mass or more and 20% by mass or less with respect to the dispersion medium. A method for coloring a laminate of silver nanoparticles, which is characterized by being present. An underlayer that is a UV-curable underlayer formed by drying, exposing, and curing in the air, or an underlayer that is a UV-curable underlayer formed by drying, exposing, and curing in a nitrogen-purged environment . At least a part of the silver nanoparticles of the silver nanoparticles laminate formed on the base layer and provided with the overcoat layer containing the silver nanoparticles is placed along the interface between the base layer and the overcoat layer. By aggregating in layers and changing the distance between the aggregated silver nanoparticles, the absorption wavelength of the silver nanoparticles is changed , and
The composition for an overcoat layer for forming the overcoat layer is a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule and at least one in the molecule. It contains at least one of the above compounds having a carboxy group and one or more polymerizable unsaturated double bonds, a compound that generates a polymerization initiation species by ionizing radiation, and a solvent.
In the composition for an overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The total content with the compound having one or more polymerizable unsaturated double bonds is in the range of 50% by mass or more and 95% by mass or less with respect to the total mass of the composition for the overcoat layer.
The content of the compound that generates the polymerization initiation species by the ionizing radiation in the composition for the overcoat layer is 0.5% by mass or more and 10% by mass or less with respect to the total solid content in the composition for the overcoat layer. Within range,
In the composition for an overcoat layer, a compound having at least one urethane bond and two or more polymerizable unsaturated double bonds in the molecule, and at least one carboxy group in the molecule. The mass ratio to the compound having one or more polymerizable unsaturated double bonds is in the range of 10: 0 to 6: 4.
The average primary particle diameter (D50) of the silver nanoparticles is in the range of 1 nm or more and 30 nm or less.
The silver nanoparticles-containing composition for dispersing the silver nanoparticles in the overcoat layer is a dispersion containing the silver nanoparticles in a range of 2% by mass or more and 20% by mass or less with respect to the dispersion medium. A method for coloring a laminate of silver nanoparticles, which is characterized by being present.

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