WO2017199969A1

WO2017199969A1 - Plasmon resonance laminate, binder-part-forming composition, method for manufacturing plasmon resonance laminate, and information recording medium

Info

Publication number: WO2017199969A1
Application number: PCT/JP2017/018397
Authority: WO
Inventors: 翔吾久保田; 陽介上羽; 知枝佐藤; 衛藤　浩司; 山本　学
Original assignee: 大日本印刷株式会社
Priority date: 2016-05-17
Filing date: 2017-05-16
Publication date: 2017-11-23

Abstract

The present disclosure provides a plasmon resonance laminate having, on one surface of a transparent substrate, a first layer having a refractive index higher than that of the substrate, and on the surface of the first layer on the opposite side from the substrate, a second layer including a binder agent and particles. The particles include a negative dielectric material and plasmon-resonate to visible light. When the second layer is positioned above the substrate, at least a part of the surface of the second layer on the opposite side from the substrate is lower than the portion of the particles most distant from the substrate.

Description

Plasmon resonance laminate, composition for forming binder part, method for producing plasmon resonance laminate, and information recording medium

The present disclosure relates to a plasmon resonance laminate that can be easily provided with designability, anti-counterfeiting properties, and the like and has excellent durability.

Some fine particles have a function of changing parameters such as electromagnetic wave responsiveness to electromagnetic waves, for example, phase and traveling direction of electromagnetic waves, polarization, and wavelength dependency of intensity. As such fine particles, for example, fine particles that cause only plasmon resonance and scatter only electromagnetic waves of a specific wavelength are known depending on the shape such as the particle size, the constituent material, and the like.

Further, Non-Patent Document 1 discloses a laminate in which silver nanocube particles are fixed on a transparent substrate surface as fine particles capable of scattering visible light by plasmon resonance. Non-Patent Document 1 discloses that the wavelength of visible light that causes plasmon resonance differs between the surface of the fine particle on the substrate side and the surface opposite to the fine particle substrate. And it is shown that the said laminated body can display an image of a different color according to whether the light irradiation surface is the base material side surface of microparticles | fine-particles or the surface on the opposite side to the base material of microparticles | fine-particles.

However, in Non-Patent Document 1, since the fine particles dispersed on the surface of the base material are exposed to the atmosphere and fixed, for example, when the user's hand touches the fine particles, the fine particles fall off and have a desired function. May not develop.

Here, it is conceivable to form an overcoat layer covering the fine particles in order to prevent the fine particles from falling off. However, in the laminate disclosed in Non-Patent Document 1, when an overcoat layer covering fine particles is formed, the refractive index difference (refractive between fine particles and overcoat layer) on the surface opposite to the substrate of the fine particles is formed. The difference between the refractive index difference on the substrate side surface of the fine particles (the difference in refractive index between the fine particles and the substrate) becomes smaller, and the opposite of the substrate side surface of the fine particles and the substrate of the fine particles. The wavelength of the plasmon-resonant light on the side surface is close. Thereby, in the laminated body disclosed in Non-Patent Document 1, it may be difficult to display images of different colors on the front and back of the laminated body.

The present disclosure has been made in view of the above problems, and has as its main object to provide a plasmon resonance laminate that is easy to impart designability, anti-counterfeiting properties, etc., and is excellent in durability. .

In order to achieve the above object, the present disclosure provides a first layer having a refractive index higher than that of the base material on one surface of a transparent base material (hereinafter sometimes referred to as a transparent base material). (Hereinafter sometimes referred to as a high refractive index layer), and a second layer (hereinafter referred to as a binder portion) containing a binder layer and particles on the surface of the first layer opposite to the base material. And the particles include a negative dielectric material, plasmon resonate with visible light, and the second layer is positioned above the substrate. Provided is a plasmon resonance laminate in which at least a part of a surface of the two layers opposite to the substrate is lower than a portion of the particle farthest from the substrate. That is, the present disclosure has a high refractive index layer having a higher refractive index than the transparent substrate on one surface of the transparent substrate, and the surface of the high refractive index layer opposite to the transparent substrate. A binder portion including a binder layer and particles, and the particles include a negative dielectric material, plasmon-resonate with respect to visible light, and the binder portion is positioned above the transparent substrate. When it does, the plasmon resonance laminated body in which at least one part of the surface on the opposite side to the said transparent base material of the said binder part is lower than the part farthest from the said transparent base material of the said particle | grain is provided. That is, the present disclosure includes a transparent base, a high refractive index layer having a higher refractive index than the transparent base disposed on one surface of the transparent base, and the transparent base of the high refractive index layer. A binder portion disposed on the opposite surface, and the binder portion includes a binder layer containing a binder agent and particles dispersed in the binder layer, and the particles are negative. A plasmon resonance laminate including a dielectric material and plasmon resonance with respect to visible light, wherein the minimum thickness of the binder layer is smaller than the maximum height of the particles.

In the present specification, the transparent substrate may be referred to as a transparent substrate, the first layer as a high refractive index layer, the second layer as a binder portion, and the particles as fine particles.

The present disclosure includes particles, a binder agent, and a dispersion medium. The particles include a negative dielectric material, plasmon-resonates with visible light, and the concentration of the binder agent with respect to the dispersion medium (binder agent / dispersion medium). However, the composition for binder part formation which is in the range of 0.1 / 100 or more and 10/100 or less is provided. In addition, the density | concentration with respect to the dispersion medium of a binder agent means the volume ratio with respect to the dispersion medium of a binder agent.

The present disclosure provides a laminate having a first layer having a higher refractive index than that of the substrate on one surface of a substrate having transparency, and particles on the surface of the first layer of the laminate. A coating step of applying a binder part-forming composition containing a binder agent and a dispersion medium; and a drying step of drying and removing the dispersion medium from the coating film of the binder part forming composition to form a second layer; The particles contain a negative dielectric material and plasmon-resonate with visible light, and the binder part forming composition has a concentration of the binder agent with respect to the dispersion medium (binder agent / dispersion medium). A method for producing a plasmon resonance laminate that is within a range of 0.1 / 100 or more and 10/100 or less. That is, the present disclosure provides a laminate in which a high refractive index layer having a higher refractive index than that of the transparent substrate is formed on one surface of the transparent substrate, and the surface of the high refractive index layer of the laminate. On top of this, a coating step of applying a binder part forming composition containing particles, a binder agent and a dispersion medium, and drying to remove the dispersion medium from the coating film of the binder part forming composition to form a binder part. The particles include a negative dielectric material, and plasmon resonate with visible light, and the binder part forming composition has a concentration of the binder agent with respect to the dispersion medium (binder agent / dispersion). The medium is provided within the range of 0.1 / 100 or more and 10/100 or less.

The present disclosure has a first layer having a refractive index higher than that of the base material on one surface of the base material having transparency, and a binder on a surface of the first layer opposite to the base material. A second layer including a layer and a particle, wherein the particle includes a negative dielectric material, plasmon-resonates with visible light, and the second layer is positioned above the substrate. An information recording medium is provided, wherein at least a part of the surface of the second layer opposite to the substrate includes a plasmon resonance laminate that is lower than a portion of the particle farthest from the substrate. That is, this indication provides an information recording medium provided with the above-mentioned plasmon resonance layered product.

This disclosure has an effect of providing a plasmon resonance laminate that can be easily provided with designability, anti-counterfeiting properties, and the like, and has excellent durability.

It is a schematic sectional drawing which shows an example of the plasmon resonance laminated body of this indication. It is a schematic sectional drawing which shows the other example of the plasmon resonance laminated body of this indication. It is a schematic sectional drawing which shows the other example of the plasmon resonance laminated body of this indication. It is a schematic plan view which shows the other example of the plasmon resonance laminated body of this indication. It is a schematic sectional drawing which shows the other example of the plasmon resonance laminated body of this indication. It is the schematic plan view and sectional drawing which show the other example of the plasmon resonance laminated body of this indication. It is process drawing which shows an example of the manufacturing method of the plasmon resonance laminated body of this indication. It is a schematic plan view which shows an example of the information recording medium of this indication. It is a schematic sectional drawing which shows the other example of the information recording medium of this indication. It is a schematic plan view which shows the other example of the information recording medium of this indication. It is a schematic sectional drawing which shows the other example of the information recording medium of this indication.

The present disclosure relates to a plasmon resonance laminated body, a binder part forming composition capable of forming a binder part included in the plasmon resonance laminated body, a method for producing a plasmon resonance laminated body capable of producing the plasmon resonance laminated body, and the plasmon resonance laminated body. The present invention relates to an information recording medium provided.

Hereinafter, the plasmon resonance laminate, the binder portion forming composition, the method for producing the plasmon resonance laminate, and the information recording medium of the present disclosure will be described in detail.

A. Plasmon Resonance Laminate The plasmon resonance laminate of the present disclosure has a high refractive index layer having a higher refractive index than that of the transparent substrate on one surface of the transparent substrate, and the transparent base of the high refractive index layer. A binder portion including a binder layer and fine particles on a surface opposite to the material, the fine particles include a negative dielectric material, and plasmon resonate with visible light, and the binder portion is the transparent substrate. When positioned higher, at least a part of the surface of the binder portion on the side opposite to the transparent substrate is lower than the most distant portion of the fine particles from the transparent substrate. That is, the plasmon resonance laminate of the present disclosure includes a transparent base, a high refractive index layer having a higher refractive index than the transparent base disposed on one surface of the transparent base, and the high refractive index layer. A binder portion disposed on a surface opposite to the transparent substrate, and the binder portion includes a binder layer containing a binder agent and fine particles dispersed in the binder layer, The fine particles include a negative dielectric material, plasmon resonate with visible light, and the minimum thickness of the binder layer is smaller than the maximum height of the fine particles.

Such a plasmon resonance laminate of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view illustrating an example of a plasmon resonance stacked body according to the present disclosure. FIG. 2 is a schematic cross-sectional view illustrating another example of the plasmon resonance multilayer body of the present disclosure. As shown in FIGS. 1 and 2, the plasmon resonance laminate 10 of the present disclosure has a refractive index higher than that of the transparent substrate 1 and the transparent substrate 1 arranged on one surface of the transparent substrate 1. A high refractive index layer 2 and a binder portion 7 disposed on a surface of the high refractive index layer 2 opposite to the transparent substrate 1, wherein the binder portion 7 includes a binder agent. 3 and fine particles 4 dispersed in the binder layer 3. The fine particles 4 contain a negative dielectric material, plasmon-resonate with visible light, and are in contact with the high refractive index layer 2. Further, the minimum thickness a of the binder layer 3 is smaller than the maximum height b of the fine particles 4. Furthermore, when the plasmon resonance laminated body 10 is disposed so that the binder portion 7 is positioned above the transparent base material 1, at least a part of the surface 7 </ b> S on the side opposite to the transparent base material 1 of the binder portion 7 has the fine particles 4. Lower than the farthest part from the transparent substrate 1 (in the example shown in FIGS. 1 and 2, the surface S of the fine particles 4 opposite to the transparent substrate 1). FIG. 2 shows an example in which the fine particles include those that are not in direct contact with the high refractive index layer. FIG. 1 shows an example in which the surface of the fine particle opposite to the transparent substrate is not covered with the binder layer, and FIG. 2 shows an example in which the surface of the fine particle opposite to the transparent substrate is covered with the binder layer. Is shown.

According to the present disclosure, since the fine particles are dispersed in the binder layer, the plasmon resonance laminate of the present disclosure can prevent the fine particles from dropping off during use, and has excellent durability. Become. Further, since the state of the fine particles dispersed in the binder layer is a state in which the minimum thickness of the binder layer is smaller than the maximum height of the fine particles, for example, the surface of the fine particles on the side opposite to the transparent substrate is the binder. It is exposed from the layer and is in contact with the atmosphere, and can further be in contact with the high refractive index layer on the transparent substrate side. As a result, it is easy to increase the refractive index difference between the surface of the fine particle on the transparent substrate side and the surface opposite to the transparent substrate of the fine particle (hereinafter sometimes referred to as the refractive index difference between the fine particle front and back). Become. For this reason, the plasmon resonance laminated body of the present disclosure can easily display images of different colors when irradiated with visible light from the front side and when irradiated with visible light from the back side. It becomes easy to give prevention properties and the like. For these reasons, the plasmon resonance laminate of the present disclosure can be easily imparted with designability, anti-counterfeiting properties, etc., and has excellent durability.

Here, the state where the surface opposite to the transparent base material of the fine particles is exposed from the binder layer is not limited to a fully exposed state where the binder layer does not exist on the surface opposite to the transparent base material of fine particles, To the extent that the plasmon resonance laminated body of the present disclosure can be observed by irradiating visible light from the fine particle side and when observing by irradiating visible light from the transparent substrate side, can be visually recognized. This includes a state in which the surface of the fine particle opposite to the transparent substrate is covered with a binder layer.

The state in which the fine particles are in contact with the high refractive index layer is not limited to the state in which the fine particles are in direct contact with the high refractive index layer, and the plasmon resonance laminate of the present disclosure was observed by irradiating visible light from the fine particle side. In a case where the binder layer is disposed between the fine particles and the high refractive index layer in such a thin thickness that the visible color development of the different colors is visible in the case of observing with visible light from the transparent substrate side. Is also included.

The plasmon resonance laminate of the present disclosure has a transparent substrate, a high refractive index layer, and a binder part including a binder layer and fine particles. Hereinafter, each structure of the plasmon resonance laminated body of this indication is demonstrated.

1. Binder Part The binder part in the present disclosure includes a binder layer and fine particles, and specifically includes a binder layer containing a binder agent and fine particles dispersed in the binder layer.

(1) State of fine particles in binder layer The fine particles in the present disclosure are dispersed in the binder layer.

The positional relationship between the binder layer and the fine particles in the present disclosure, that is, the state of the fine particles in the binder layer is a state where the minimum thickness of the binder layer is smaller than the maximum height of the fine particles. As for the positional relationship between the fine particles and the binder layer as described above, when the plasmon resonance laminate is disposed so that the binder portion is located above the transparent substrate, the surface of the binder portion on the side opposite to the transparent substrate is disposed. It can also be said that at least a part is lower than the part of the fine particles farthest from the transparent substrate.

Here, the minimum thickness of the binder layer is the minimum of the distance from the surface opposite to the high refractive index layer of the binder layer to the high refractive index layer, in a portion that does not overlap with the fine particles of the binder layer in plan view. Usually, it means the distance from the portion closest to the transparent substrate on the surface opposite to the high refractive index layer of the binder layer to the high refractive index layer. Specifically, the minimum thickness is a distance indicated by a in FIGS. 1 and 2 described above.

The maximum height of the fine particles refers to the maximum distance among the distances from the surface opposite to the high refractive index layer of the fine particles in the binder layer to the high refractive index layer. This is the distance from the portion farthest from the high refractive index layer.

Here, the portion of the fine particles farthest from the transparent substrate is, for example, in the case of FIG. 1 or FIG. 2, the surface S of the fine particles 4 in the binder layer 3 opposite to the high refractive index layer 2. I mean. Further, when the fine particles 4 are spherical, triangular pyramid or the like, it means a portion P farthest from the transparent substrate 1 of the fine particles 4 as shown in FIG. Further, even when the fine particles have a cubic shape, as shown in FIG. 3B, when the cubic-shaped fine particles 4 are held inclined in the binder layer 3, the cubic-shaped top part P is the fine particles 4. This is the portion farthest from the transparent substrate 1.

Therefore, specifically, the maximum height is a distance indicated by b in FIGS. 1 to 3 already described.

Of all the fine particles dispersed in the binder layer in the present disclosure, the number of fine particles whose maximum height is higher than the minimum thickness of the binder layer, that is, among the total fine particles in the binder portion, the side opposite to the transparent base material of the binder portion The number of fine particles in which at least part of the surface of the fine particles is lower than the portion of the fine particles farthest from the transparent substrate may be at least one, preferably 50% or more of the total fine particles, All fine particles are preferred. This is because the binder layer can stably increase the refractive index difference between the front and back surfaces of the fine particles when the proportion of the fine particles exhibiting the above state is in the above range.

The difference between the minimum thickness of the binder layer and the maximum height of the fine particles, that is, the difference obtained by subtracting the minimum thickness of the binder layer from the maximum height of the fine particles may be larger than 0 nm. From the viewpoint of stably increasing the difference in refractive index between the two, the larger the difference, the better. For example, the difference is preferably 2 nm or more, more preferably 10 nm or more and 200 nm or less, and particularly preferably 30 nm or more and 150 nm or less. Since the difference is within the above-described range, the binder layer can stably increase the refractive index difference between the front and back of the fine particles, and can further prevent the fine particles from falling off. is there.

The relationship between the average thickness of the binder layer and the average primary particle size of the fine particles may be any as long as the minimum thickness of the binder layer can be smaller than the maximum height of the fine particles. The average thickness of the fine particles may be larger than the average primary particle size of the fine particles, but is preferably smaller than the average primary particle size of the fine particles, and the average thickness of the binder layer is the average primary particle size of the fine particles. The particle size is preferably 95% or less of the particle size, more preferably 10% or more and 90% or less, and particularly preferably 25% or more and 50% or less. Since the average thickness is within the above-mentioned range with respect to the average primary particle size of the fine particles, the binder layer can be easily in a state where the minimum thickness of the binder layer is smaller than the maximum height of the fine particles. It is. Further, the binder layer can stably increase the refractive index difference between the front and back of the fine particles, and can stably prevent the fine particles from falling off.

Note that the average thickness of the binder layer refers to the average value of the thickness at any 10 points in the binder layer that do not overlap with the fine particles in plan view.

Further, the average primary particle size can be obtained by a method of directly measuring the size of primary particles from an electron micrograph. Specifically, a particle image was measured with a transmission electron micrograph (TEM) (for example, H-7650 manufactured by Hitachi High-Tech), and an average value of equivalent area circle equivalent diameters of 100 randomly selected primary particles was calculated. The average primary particle size can be obtained. The electron microscope may be either a transmission type (TEM) or a scanning type (SEM). The equivalent area equivalent circle diameter can be calculated from the area and circumference of the obtained particle image by 4 × area / circumference.

In addition, the average thickness of the binder portion refers to the average thickness of the portion not including the fine particles in the binder portion, and specifically, can be the same as the average thickness of the binder layer. The relationship between the average thickness of the binder portion and the average primary particle size of the fine particles can be the same as the relationship between the average thickness of the binder layer and the average primary particle size of the fine particles. Specifically, it is preferable that the average thickness of the binder portion is smaller than the average primary particle size of the fine particles, that is, the average thickness of the portion not including the fine particles of the binder portion is smaller than the average primary particle size of the fine particles. This is because the difference in refractive index between the front and back of the fine particles is stably increased.

The surface of the fine particle opposite to the transparent substrate is usually in an exposed state that is not covered with the binder layer. Here, the exposure state is not limited to a state in which the fine particles are completely exposed in which no binder layer is present on the surface, and the plasmon resonance laminate of the present disclosure is irradiated with visible light from the fine particle side. In the case of observation and the case of observation by irradiating visible light from the transparent substrate side, the surface is covered with a binder layer with such a thin thickness that it is possible to visually recognize different colors.

The thickness on the surface of the binder layer opposite to the transparent substrate when the surface opposite to the transparent substrate of the fine particles is exposed can be, for example, 10 nm or less. In particular, the thickness is preferably 5 nm or less, particularly preferably 2 nm or less, and preferably 0 nm, that is, the surface opposite to the transparent substrate of the fine particles is preferably completely exposed. . When the thickness is in the above-described range, the plasmon resonance laminate of the present disclosure has different colors when irradiated with visible light from the fine particle side and when irradiated with visible light from the transparent substrate side. This is because it can be stably displayed, and it is easy to provide designability, anti-counterfeiting properties, and the like. In addition, the thickness on the surface on the opposite side to the transparent base material of the fine particle of the said binder layer is specifically shown by d in already demonstrated FIG.

The fine particles are usually in contact with the high refractive index layer. Here, being in contact with the high refractive index layer is not limited to the state in which the fine particles are in direct contact with the high refractive index layer, and when the plasmon resonance laminate of the present disclosure is observed by irradiating visible light from the fine particle side. In addition, it includes a case where a binder layer is disposed between the fine particles and the high refractive index layer with such a thin thickness that it is possible to visually recognize the development of different colors, when observed by irradiating visible light from the transparent substrate side. .

When the fine particles are in contact with the high refractive index layer, the distance between the fine particles and the high refractive index layer can be, for example, 10 nm or less, preferably 5 nm or less, particularly 2 nm. The following is preferable, and it is preferably 0 nm, that is, it is preferable that the surface of the fine particle on the transparent substrate side is in direct contact with the high refractive index layer. It is because the said binder layer can enlarge the refractive index difference between fine particle front and back stably because the said space | interval is the above-mentioned range. As a result, the plasmon resonance laminated body of the present disclosure can stably display different colors when irradiated with visible light from the fine particle side and when irradiated with visible light from the transparent substrate side. This is because it becomes easy to impart design properties, anti-counterfeiting properties, and the like. The distance between the fine particles and the high refractive index layer is specifically shown by c in FIG.

The density of the fine particles to be dispersed in the binder layer, for example, may be any light of a specific wavelength of irradiated light as it can be scattered on a desired strength, 10 ¹⁰ 10 ⁵ / cm ² or more / Cm ² or less.

The interval between the fine particles dispersed in the binder layer may be one type of interval, that is, one that is arranged at equal intervals, but is randomly arranged and the interval becomes two or more types. It may be.

(2) Binder Layer The binder layer in the present disclosure is disposed on the surface of the high refractive index layer opposite to the transparent substrate and includes a binder agent. The binder layer is a part other than the particles in the binder part.

(A) Binder Agent Any binder agent may be used as long as the fine particles can be dispersed and held in the above-described state. As such a binder agent, a non-volatile material having a low surface tension can be used.

Here, the term “nonvolatile” means any material that is normal temperature and normal pressure (25 ° C., atmospheric pressure) and does not volatilize. More specifically, the boiling point is 100 ° C. or higher. Among them, those having a temperature of 150 ° C. or higher are preferable.

Surface tension refers to the energy (unit is mN / m or mJ / m ² ) required to create a surface with a unit area and is an index of the force attracted by the surface molecules. is there. This is the energy per unit area of the system that increases when a part of a mass of material forms a new surface.

The surface tension of the binder agent can be, for example, 80 mN / m or less, and is preferably in the range of 6 mN / m to 73 mN / m, and more preferably 15 mN / m to 50 mN / m. It is preferable to be within the range. Because the surface tension is within the above range, a thin thin film can be stably formed with respect to the high refractive index layer, and a binder layer capable of dispersing fine particles in the above state can be stably formed. is there.

When the binder agent is in a liquid state, for example, a surface free energy measuring method described in JP-A-2016-41790 can be used as a surface tension measuring method.

When the binder agent is in a solid state, the surface tension (surface free energy) is measured, for example, by measuring the contact angle of pure water, methylene iodide or α-bromonaphthalene as a reagent to the surface of the binder agent. However, a method obtained by the extended Forkes theory can be used. Specifically, the surface free energy measuring method described in JP-A-2014-98910 can be used.

Furthermore, the measurement target of the surface tension of the binder agent is measured in the state of the binder agent contained in the binder layer. For example, when the binder agent is contained in the binder layer as a mixture of two or more binder agents, the measurement object is a mixture, and when the binder agent is contained in the binder layer in a polymerized state, measurement is performed. The object is a polymer of a binder agent. More specifically, when a mixture of a resin material and a silicone compound is contained in the binder layer as the binder agent, the measurement object is a mixture of the resin material and the silicone compound, and the silicone agent is used as the binder agent. When the polymer of the compound is contained in the binder layer, the measurement object is a polymer of the silicone compound. In addition, as a measuring method of the surface tension when the measurement object is a polymer, a composition not containing fine particles, for example, a binder component containing a monomer component and other binder agent as required, and a polymerization initiator are used. A method of forming a measurement binder layer by forming a coating film of the composition containing the composition and then polymerizing the monomer components in the coating film can be used.

Specific examples of the non-volatile material having a low surface tension that can be used as the binder agent include silicone compounds and fluorine compounds. In the present disclosure, the binder agent preferably contains at least one of a silicone compound and a fluorine compound. This is because by using the binder agent, a binder layer in which the fine particles are in the above-described state can be easily formed. The binder agent may be a silicone compound and a fluorine compound, respectively, or a mixture of both.

Hereinafter, the silicone compound and the fluorine compound used in the present disclosure will be described.

(I) Silicone Compound As the silicone compound, a compound having a siloxane bond (—Si—O—) _n and a polysiloxane structure in which n is 1 or more as a skeleton can be used. The silicone compound may be one in which at least one of a methyl group, a phenyl group and hydrogen is bonded to the side chain or terminal of silicon constituting the polysiloxane structure. Specifically, the silicone compound includes dimethyl silicone in which all of the side chains and terminals of the polysiloxane structure are methyl groups, methyl phenyl silicone in which part of the side chains are phenyl, and part of the side chains are hydrogen. The methyl hydrogen silicone etc. which are can be used.

As the silicone compound, a modified silicone having an organic group introduced into the side chain or terminal of silicon constituting the polysiloxane structure can also be used. Examples of the modified silicone include reactive modified silicone having a reactive functional group as an organic group, and non-reactive modified silicone having a non-reactive functional group as an organic group.

The reactive functional group is not particularly limited as long as the desired reactivity can be imparted to the silicone compound. For example, the functional group capable of crosslinking the modified silicones with each other through a covalent bond includes a vinyl group, a styryl group, and a methacrylic group. And a polymerizable group such as a group and an acrylic group, an amino group, an epoxy group, a carbinol group, and a carboxyl group.

The non-reactive functional group can be, for example, a functional group capable of exhibiting an interaction due to hydrogen bonding between modified silicones, for example, a polyether group, an aralkyl group, a long-chain alkyl group, a higher chain. Examples include fatty acid ester groups and phenol groups.

Furthermore, as the silicone compound, a linear silicone having a structure in which siloxane bonds are linearly bonded, or a network silicone in which a siloxane bond has a three-dimensional network structure can be used.

Furthermore, as the network silicone, when the silicone compound has a reactive function such as a polymerizable group, a crosslinked product having a three-dimensional network structure formed by bonding of the reactive functional groups to each other is also included. Can be used.

Among these, in the present disclosure, the silicone compound is preferably a network silicone. This is because the silicone-based compound as the binder agent can stably hold the fine particles.

Various types of silicone compounds can be used depending on their properties. For example, silicone surfactants, silicone oils, silicone oligomers, silicone resins, and reactive functional groups possessed by these are bonded to each other. Can be mentioned.

The above silicone compounds may be used alone or as a mixture of two or more.

The silicone-based surfactant is not particularly limited as long as it has a surface-active ability. For example, a linear silicone can be used as a hydrophilic group on the side chain or terminal of silicon constituting the polysiloxane structure. Specific examples include those having a polyether group or amino group bonded thereto, specifically, polyether-modified silicone oil, amino-modified silicone oil, and the like. Among these, polyether-modified silicone oil is preferable. This is because the silicone-based surfactant can stably hold the fine particles.

As the silicone oil, for example, linear silicone can be used, and specifically, dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, reactive modified silicone oil, non-reactive modified silicone. An oil etc. can be mentioned, Especially, it is preferable that it is a reactive modified silicone oil etc. This is because the reactive modified silicone oil can be contained in the binder layer as a cross-linked product cross-linked with reactive functional groups, for example, and the fine particles can be stably retained.

As the silicone resin (silicone monomer polymer), for example, a siloxane bond having a three-dimensional network structure can be used. Specifically, dimethyl silicone resin, methylphenyl silicone resin, alkyd resin-modified silicone, and the like can be used. An organic resin-modified silicone resin such as a resin, a polyether-modified silicone resin, and the like can be given. Among them, a methyl silicone resin, a methylphenyl silicone resin, and the like are preferable. This is because the silicone resin can stably hold fine particles.

The organic resin-modified silicone is obtained by bonding an organic resin as an organic group, and examples of the organic resin include a polyester resin, an alkyd resin, and an epoxy resin.

Specific examples of the silicone oligomer include non-reactive alkoxysilicone oligomers, reactive functional group-containing alkoxysilicone oligomers, reactive functional group-containing silicone oligomers, etc. Among them, reactive functional group-containing alkoxy Silicone oligomers and reactive functional group-containing silicone oligomers are preferred. The reactive modified silicone oligomer containing the reactive functional group can be contained, for example, in the binder layer as a cross-linked product obtained by cross-linking reactive functional groups, and can stably hold fine particles. Because.

The silicone oligomer refers to a dimer or trimer of a silicone monomer having a molecular weight of about 1000. For example, a relatively low molecular silicone resin having a three-dimensional network structure can be used.

The non-reactive alkoxysilicone oligomer does not contain a reactive functional group, and further has an alkoxy group bonded to the side chain or terminal of silicon constituting the polysiloxane structure. In the oligomer, a reactive functional group and an alkoxy group may be bonded using a side chain or a terminal.

(Ii) Fluorine compound The fluorine compound may be any compound having fluorine. For example, a perfluoroalkyl group (—CF 3) in which all or part of the hydrogen atoms in the hydrocarbon group are substituted with fluorine atoms. _2- ) Those having a fluorine-containing group such as _n can be used. The carbon number n of the perfluoroalkyl group may be 1 or more, and can be appropriately set within a range in which the fine particles can be dispersed in the above-described state, and is adjusted according to the molecular weight of the fluorine-based compound. Is. As the perfluoroalkyl group, for example, those having a carbon number n of 30 or less can be used.

The fluorine compound may have other functional groups in addition to the fluorine-containing group. As said other functional group, you may have a lipophilic group, a hydrophilic group, an ultraviolet-ray (UV) reactive group, and the salt of an acidic group.

The lipophilic group is not particularly limited as long as it can improve the lipophilicity of the fluorine-based compound, and examples thereof include an alkyl group, a phenyl group, and a siloxane group.

The hydrophilic group is not particularly limited as long as it can improve the hydrophilicity of the fluorine-based compound. Examples thereof include an ethylene oxide group, an amide group, a ketone group, a carboxyl group, a sulfone group, an alkoxy group, and a phosphoric acid group. be able to.

The UV-reactive group is not particularly limited as long as it can be polymerized by ultraviolet rays. For example, the UV-reactive group can be the same as the polymerizable group described in the section “(a) Silicone compound”.

The acid group is not particularly limited as long as it can exhibit acidity in water, and examples thereof include a carboxyl group, a sulfone group, and phosphoric acid. Examples of the salt include sodium salt and potassium salt. be able to.

Further, as the fluorine-based compound, perfluoroether in which perfluoroalkyl groups are bonded by an ether bond can also be used. When the fluorine-based compound has a UV reactive group, it may be a cross-linked product having a three-dimensional network structure in which the UV reactive groups are bonded to each other.

As such a fluorine-based compound, various compounds can be used depending on the properties thereof, and examples thereof include a fluorine-based surfactant, a fluorine-based coating agent, etc., and others include a fluorine-based liquid, etc. Can be mentioned. Although the said fluorine-type compound may be used individually by 1 type, two or more types of mixtures may be sufficient as it. In particular, in the present disclosure, the fluorine compound is preferably a fluorine surfactant. This is because the fluorosurfactant can stably hold fine particles.

Specific examples of the fluorine-based surfactant include PFOS (perfluoroalkyl sulfonic acid), PFOA (perfluoroalkyl carboxylic acid), fluorine telomer alcohol (F (CF ₂ ) _n CH ₂ CH ₂ OH, n is 1 or more integers), hexafluoropropene (HFP) trimer derivative, perfluorobutane sulfonate (Megafac F-114 manufactured by DIC), fluorine-containing / lipophilic group-containing oligomer (Megafac F-251 manufactured by DIC) F-253, F-281, F-551, F-552, F-554, F-558, F-560, F-561, F-563, R-41, R-43), perfluoroalkyl groups Containing carboxylate (Megafac F-410 made by DIC), fluorinated group / hydrophilic group-containing oligomer (Megafac made by DIC) -430, F-569, EXP.TF-1540), perfluoroalkylethylene oxide adduct (Megafac F-444, EXP.TF-2066, manufactured by DIC), fluorine-containing group / hydrophilic / lipophilic group-containing oligomer ( DIC MegaFuck F-477, F-553, F-555, F-556, F-557, F-559, F-562, F-565, F-568, F-571, R-40, R -40-LM, EXP.TF-1760), perfluoroalkyl group-containing phosphoric acid ester type amine neutralized product (Megafac F-511, EXP.TF-2149, manufactured by DIC), fluorine-containing group, hydrophilic group, Lipophilic group / carboxyl group-containing oligomer, fluorine-containing group / hydrophilic group / lipophilic group / UV-reactive group-containing oligomer (Megafac RS-55, RS manufactured by DIC) -56, RS-72-K, RS-75, RS-76-E, RS-76-NS, RS-77, RS-78, RS-90), among others, fluorine-containing groups -It is preferably a hydrophilic group, lipophilic group, UV-reactive group-containing oligomer or the like. This is because the fluorosurfactant can be contained in the binder layer as a cross-linked product cross-linked with reactive functional groups, for example, and the fine particles can be stably retained.

Specific examples of the fluorine-based coating agent include modified perfluoroether.

Specific examples of the fluorinated liquid include hydrofluoroether. As the hydrofluoroether, for example, a separated hydrofluoroether or a non-separable hydrofluoroether described in JP-A-2015-129249 can be used.

(Iii) Others The binder agent may contain at least one of a silicone compound and a fluorine compound, and may contain only at least one of a silicone compound and a fluorine compound. In addition, a resin material other than the silicone compound and the fluorine compound may be included. That is, the binder agent may be a mixture of at least one of a silicone compound and a fluorine compound and a resin material.

The resin material may be any resin other than a silicone compound and a fluorine compound, that is, any resin that does not contain a siloxane bond and does not contain a fluorine-containing group such as a perfluoroalkyl group. Can be used. Specifically, the resin material is not particularly limited as long as it can form a binder layer capable of dispersing fine particles in the above-described state, and examples thereof include acrylic resins, urethane acrylic resins, and epoxy resins.

The content of the resin material in the binder agent can be appropriately set within a range in which a binder layer capable of dispersing fine particles in the above-described state can be formed.

The content of the binder agent in the binder layer is not particularly limited as long as the fine particles can be stably dispersed in the above-described state, and can be, for example, 90% by mass or more, and 95% by mass or more. Is preferable, and it is preferable that it is 100 mass%. In addition, the upper limit of the content of the binder agent in the binder layer is usually preferably as large as possible, but can be 99% by mass or less from the viewpoint of easy adjustment of the function of the binder layer by using an additive or the like. . In addition, content in a binder layer means content in the location which does not contain microparticles | fine-particles among binder layers.

(B) Binder layer Although the said binder layer contains a binder agent, it may contain another component as needed. Such other components include polymerization initiators, polymerization inhibitors, sensitizers, crosslinking agents, plasticizers, flame retardants, charge control agents, thermal stabilizers, light stabilizers, conductive agents, preservatives, antifoaming agents. Agents, rust inhibitors, antioxidants, fluorescent agents, fluorescent brighteners, near infrared absorbers, ultraviolet absorbers, emulsifiers and the like.

In the case where the binder agent is a polymer of monomer components, for example, after coating the binder part forming composition containing the monomer component, fine particles and dispersion medium as the binder agent on the surface of the high refractive index layer, the coating film In the case where the binder layer is formed by polymerizing the monomer components, the polymerization initiator used for the polymerization of the monomer component and the residue thereof are included as the other components. Also good.

The planar view shape of the binder layer may be a shape covering the entire surface of the high refractive index layer, but is preferably a pattern shape such as a pattern or a character from the viewpoint of providing designability and anti-counterfeiting properties. This is because the shape in plan view makes it easy to impart designability and the like to the plasmon resonance laminate by the fine particles dispersed in the binder layer. The pattern shape may be a dot shape, a line shape, or the like. The dot shape may be any shape such as a circular shape or a square shape. The planar view shape may represent a symbol, a character, or the like. For example, the shape in plan view may represent a character or the like using a line-shaped binder layer, or may represent a character or the like using a dot-shaped binder layer. 1 and 2 which have already been described show an example in which the planar view shape of the binder layer 3 covers the entire surface of the high refractive index layer 2, and FIG. The example which shows a character using the binder layer 3 of a line shape in planar view is shown. FIG. 4 is a schematic plan view showing another example of the plasmon resonance laminated body of the present disclosure, and the description of fine particles dispersed in the binder layer 3 is omitted for easy explanation. FIG. 4 shows an example in which the planar view shape represents the number “123”.

The thickness of the binder layer is not particularly limited as long as the fine particles can be dispersed in the above-described state, and varies depending on the size of the fine particles to be dispersed. For example, the thickness may be in the range of 1 nm to 200 nm. it can.

(3) Fine particles The fine particles are contained in the binder portion and are dispersed in the binder layer. The fine particles include a negative dielectric material and plasmon resonate with visible light.

Here, plasmon resonance with respect to visible light means that when visible light is irradiated to the fine particles, visible light having a specific wavelength can be scattered by the localized surface plasmon resonance of the fine particles (also referred to as localized surface plasmon polaritons). It means that.

Also, the wavelength of visible light that resonates with plasmon (hereinafter sometimes simply referred to as light) is affected by the shape of the fine particles, the constituent material, and the like. For this reason, the fine particles can adjust the wavelength of the plasmon-resonant visible light by adjusting the shape and constituent materials. For example, red, blue, yellow can be used as specific colors when irradiated with white light. Etc. can be scattered.

The wavelength of light that causes plasmon resonance can be in the range of 360 nm or more and 830 nm or less, and preferably in the range of 400 nm or more and 760 nm or less. This is because light having a wavelength within this range is easily perceived in consideration of human visibility.

The average primary particle size of the fine particles may be any as long as it has plasmon resonance with respect to light, and is preferably in the range of 2 nm to 200 nm, for example, in particular, in the range of 5 nm to 150 nm. In particular, it is preferably in the range of 10 nm to 100 nm. This is because, when the average primary particle size is within the above range, the fine particles easily cause plasmon resonance to light having a wavelength within the above range. The type of the average primary particle size is not limited to one using only one type, and two or more types may be used. When there are two or more types of average primary particle sizes, for example, fine particles having an average primary particle size in the range of 100 nm and fine particles having an average primary particle size of 200 nm can be mixed and used. In addition, the average primary particle size has a particle size including a coating layer when the fine particles have negative dielectric material particles and a coating layer covering the surface thereof.

The particle size distribution of the fine particles may be a particle size distribution that enables plasmon resonance with respect to light in a specific wavelength band within the above range. For example, from the viewpoint of displaying an image of a specific color, the particle size distribution Is preferably narrow. The narrow particle size distribution can be evaluated by the value of the ratio of D90 to D50 (D90 / D50) when the particle size of 50% cumulative and 90% cumulative is D50 and D90 from the fine particle side of the cumulative particle size distribution, for example. . For example, D90 / D50 is preferably 2 or less, and particularly preferably 1.5 or less.

The shape of the fine particles is not particularly limited as long as it has plasmon resonance with respect to light.For example, a spherical shape or a cylindrical shape may be used. A shape having a disk shape or other plate-like corners is preferable. This is because the fine particles tend to cause plasmon resonance because the shape is a shape having corners. In the present disclosure, it is particularly preferable that the shape is a cubic shape or a rectangular parallelepiped shape. This is because the fine particles tend to cause plasmon resonance and are easy to manufacture because of the shape. The type of the shape is not limited to one using only one type, and two or more types may be used. When there are two or more types of shapes, for example, spherical fine particles and cubic fine particles can be mixed and used.

The negative dielectric material contained in the fine particles is a material having a negative real part of dielectric constant in a specific wavelength region where plasmon resonance is desired. As the negative dielectric material, specifically, for visible light, a metal, a metal oxide, or an impurity semiconductor can be used. In the present disclosure, the negative dielectric material is preferably a metal. This is because the above-described constituent material is easy to perform plasmon resonance with respect to visible light.

As the metal, for example, silver, gold, copper, aluminum, platinum, palladium, aluminum and the like are preferable, and silver is particularly preferable. This is because the metal can easily perform plasmon resonance in the visible light region. The metal oxide is not particularly limited as long as the real part of the dielectric constant is negative. For example, indium tin oxide (ITO) used for forming the transparent electrode layer of JP-A-2015-194799 is used. An inorganic conductive material can be mentioned. As the impurity semiconductor, for example, those described in JP-A-2015-232713 can be used. The type of the negative dielectric material is not limited to one using only one type, and two or more types may be used. When there are two or more types of negative dielectric materials, for example, fine particles containing silver as the negative dielectric material and fine particles containing gold as the negative dielectric material can be mixed and used.

The fine particles contain a negative dielectric material as a main component. Here, being contained as the main component means that the fine particles can be contained to such an extent that plasmon resonance can be performed with respect to visible light. For example, the fine particles are contained in an amount of 80% by mass or more. it can. In the present disclosure, among them, the negative dielectric material is preferably contained in the fine particles in an amount of 90% by mass or more, and particularly preferably 95% by mass or more. Further, the content of the negative dielectric material in the fine particles may be 100% by mass, that is, the fine particles may be composed of only the negative dielectric material, but may be less than 100% by mass. That is, the fine particles include a negative dielectric material, but may include other materials as necessary. For example, the fine particles may be those in which the surface of the negative dielectric material particles is covered with a coating layer, that is, the fine particles include a material that covers the surface of the negative dielectric material particles. This is because the fine particles can be prevented from being aggregated by being covered with the coating layer.

As the material constituting the coating layer, a resin material capable of binding to the surface of fine particles made of a negative dielectric material can be used. For example, polyethylene glycol (PEG), PEG derivative, polyvinyl pyrrolidone (PVP), citric acid Examples thereof include ions, carbonate ions, α-lipoic acid, branched polyethyleneimine (BPEI), silica, silica derivatives, and alkylthiols.

The thickness of the coating layer may be any thickness as long as it does not significantly interfere with the plasmon resonance of the fine particles, but from the viewpoint that the plasmon resonance laminate of the present disclosure can easily observe images of different colors on the front side and the back side. Can be, for example, 2 nm or less.

2. High refractive index layer The high refractive index layer is a layer having a higher refractive index than the transparent substrate disposed on one surface of the transparent substrate. The high refractive index layer is usually in direct contact with the binder layer.

In addition, it can be assumed that the refractive index is higher than that of the transparent substrate in the visible light region. The wavelength range of the visible light region can be the same as the wavelength of visible light described in the above section “1. Binder part (3) Fine particles”.

The high refractive index layer only needs to have a refractive index higher than that of the transparent substrate, and the higher the refractive index, the better. For example, the refractive index n _{D at} a wavelength of 589 nm (sodium D line) is 1.5. It is preferable that it is above, and it is particularly preferable that it is 2 or more. In addition, although the upper limit of the said refractive index is suitably set according to the color development observed by the front and back of the plasmon resonance laminated body of this indication, it is 4 or less normally. The refractive index can be measured by a thin film measuring apparatus using reflectance spectroscopy or a spectroscopic ellipsometer.

The high refractive index layer usually has a light transmission property capable of transmitting the light. Here, having light transmittance means that the transmittance of light having a wavelength scattered by plasmon resonance can be 70% or more, and preferably 90% or more.

The high refractive index layer may be any layer that transmits at least light having a wavelength scattered by plasmon resonance, but preferably has a visible light transmission property that transmits the entire visible light. Here, having the visible light transmittance means that the total light transmittance of the high refractive index layer can be 70% or more, and preferably 90% or more. This is because, when the total light transmittance is within the above-described range, the plasmon resonance laminated body of the present disclosure can easily observe the effect of plasmon resonance of fine particles from the transparent substrate side.

In addition, the upper limit of the light transmittance and the total light transmittance of the high refractive index layer is preferably higher, but from the viewpoint of imparting a desired strength to the high refractive index layer, the degree of freedom of material selection, etc. 95% or less.

Further, the total light transmittance can be measured according to JIS K7361-1 (Testing method for total light transmittance of plastic-transparent material).

The constituent material of the high refractive index layer may be any material as long as the refractive index difference with the transparent base material can be within a desired range, and the constituent material of the transparent base material is an organic material such as an acrylic resin described later, In the case of glass as an inorganic material, titanium oxide (IV), chromium oxide (III), zinc sulfide, aluminum oxide, barium sulfate, barium titanate, antimony trioxide, iron (III) oxide, cadmium sulfide, Inorganic compounds such as cerium (IV) oxide, lead (II) chloride, cadmium oxide, tungsten (VI) oxide, indium (III) oxide, lead (II) oxide, tantalum oxide (V), zirconium oxide (IV), Examples thereof include inorganic substances such as silicon.

The thickness of the high refractive index layer can be appropriately set according to the light transmittance required for the high refractive index layer. As said thickness, it can be in the range of 10 nm or more and 1000 nm or less, for example, It is preferable that it is in the range of 20 nm or more and 100 nm or less especially. This is because, when the thickness is equal to or greater than the lower limit, the plasmon resonance laminate of the present disclosure can easily display images of different colors on the front and back sides. Moreover, it is because it becomes easy to visually recognize the scattered light generated by plasmon resonance because the thickness is within the above-mentioned range.

The formation method of the high refractive index layer can be appropriately set according to the constituent material of the high refractive index layer. When the constituent material is an inorganic compound, a general film formation method such as a sputtering method or a sol-gel method can be used as the formation method.

3. Transparent base material The transparent base material supports the high refractive index layer and the binder layer.

The above-mentioned transparent base material usually has light transmissivity that can transmit the above light, that is, has transparency. Moreover, the transparent base material only needs to transmit at least light having a wavelength scattered by plasmon resonance, but preferably has visible light permeability that transmits the entire visible light. The light transmittance and the total light transmittance of such a transparent base material can be the same as the contents described in the above section “2. High refractive index layer”.

The constituent material of the transparent substrate may be any material as long as it has a desired transparency and does not break when the user uses the plasmon resonance laminate. Examples of the constituent material that can be used for the transparent substrate include polyethylene terephthalate (PET), acrylic resin (PMMA), polycarbonate, triacetyl cellulose (TAC), cycloolefin polymer (COP), polyethylene (PE), and polypropylene. An organic material such as (PP), silicone rubber, or polyethylene naphthalate (PEN), an inorganic material such as glass, a hybrid material of an organic material and an inorganic material, or the like can be used.

The structure of the transparent substrate may be a plate-like structure, a porous structure having a large number of pores, a nonwoven fabric structure such as paper, and the like. The transparent substrate may have a single layer structure or a laminated structure in which two or more layers are laminated.

The rigidity of the transparent substrate may be flexible so that it can be bent or may not be bent.

The surface of the transparent substrate on which the fine particles are arranged may be an uneven surface, but is preferably a flat surface. This is because the transparent substrate has less influence on the plasmon resonance of the fine particles because it is a flat surface.

The arithmetic average roughness Ra of the transparent substrate surface can be 200 nm or less, and preferably 100 nm or less. This is because, when the arithmetic average roughness Ra is within the above range, the transparent base material has less influence on the plasmon resonance of the fine particles. The arithmetic average roughness Ra refers to the arithmetic average roughness Ra defined in JIS B 0601: 2001.

The thickness of the transparent substrate is not particularly limited as long as it can stably support fine particles, and varies depending on the constituent material, required light transmittance, and the like. For example, the thickness is in the range of 10 μm to 2000 μm. It is preferable that it is in the range of 15 μm or more and 250 μm or less, and in particular, it is preferably in the range of 20 μm or more and 100 μm or less. This is because the transparent substrate can stably support the fine particles when the thickness is within the above range. In addition, the said thickness says the whole thickness, when a transparent base material is a laminated structure.

4). Other Configurations The plasmon resonance laminate of the present disclosure includes a transparent substrate, a high refractive index layer, a binder layer, and fine particles, but may have other configurations as necessary.

As such other configuration, for example, as illustrated in FIG. 5A, the high refractive index layer 2 is disposed on the surface opposite to the transparent base material 1 and is higher than the fine particles 4. Examples of the thick film member 5 include a cover layer 6 supported by the thick film member 5 as illustrated in FIG. By having the thick film member or the cover layer, it is possible to protect the user's finger from coming into contact with the fine particles when the user touches the plasmon resonance laminate of the present disclosure. is there.

(1) Thick film member The thick film member is higher in height than the fine particles. Here, “higher than the fine particles” means larger than the average primary particle size of the fine particles.

With respect to the thick film member, for example, as shown in FIG. 5A, the height and interval at which the user's finger does not touch the fine particles when the user touches the plasmon resonance laminate is described. And can be used to protect fine particles only with a thick film member (first embodiment), and used as a spacer for supporting the cover layer as shown in FIG. 5B (second embodiment). ) Etc.

(A) First Embodiment The first embodiment of the thick film member has a height and a distance at which the user's finger does not touch the fine particles when the user touches the plasmon resonance laminate. Fine particles can be protected only by the membrane member.

The height of the thick film member is higher than that of the fine particles, and the finger does not touch the fine particles when the user touches the plasmon resonance laminate. Such height is appropriately set according to the size of the fine particles and the like. As described above, the average primary particle size of the plasmon-resonant fine particles is as small as about 0.2 μm or less. In the case of fine particles, the thickness of the thick film member can be in the range of 0.3 μm to 1 mm. This is because, when the height is within the above-described range, it is possible to stably protect the user's finger from contact with the fine particles when the plasmon resonance laminate is used. Specifically, the height is indicated by e in FIG.

The distance between the thick film members is such that when the user touches the plasmon resonance laminate, the finger does not touch the fine particles. Such an interval can be wider than the average primary particle size of the fine particles. Here, in the case where the average primary particle size of the fine particles that resonate with plasmon is as small as about 0.2 μm or less as described above, the interval is, for example, in the range of 10 μm to 2 mm. be able to. In addition, the space | interval of the said thick film member means the distance between adjacent thick film members used as the shortest about each thick film member. Moreover, when the planar view shape of a thick film member is a shape which has the opening part mentioned later, it means the shortest thing among the distances between the thick film members separated by the opening part. Specifically, the interval is indicated by f in FIG.

The shape of the thick film member in plan view is not particularly limited as long as it exhibits a strength that does not cause damage when the user uses the plasmon resonance laminate, and can be a dot shape, a line shape, or the like. The shape in plan view may be a shape having openings such as a honeycomb shape or a lattice shape, or a shape having random openings. 6A and 6B are a schematic plan view and a cross-sectional view showing another example of the plasmon resonance multilayer body of the present disclosure, and FIG. 6B is a cross-sectional view taken along the line AA in FIG. ) Is a cross-sectional view taken along the line BB of FIG. 6C, and FIG. 6F is a cross-sectional view taken along the line CC of FIG. 6E. 6A and 6B, FIG. 6C and FIG. 6D, and FIG. 6E and FIG. 6F, the shape in plan view is a dot shape, a line shape, and an opening portion, respectively. An example is given.

Further, the planar view shape of the thick film member in the case of a dot shape may be a circular shape, a polygonal shape such as a triangular shape or a quadrangular shape. Note that FIG. 6A already described shows an example in which the dot-like thick film member has a square shape in plan view.

The size of the thick film member in plan view may be any size as long as it exhibits strength that does not break when the user uses the plasmon resonance laminate, and can be in the range of 0.1 μm to 100 μm. The size in plan view refers to the maximum diameter in the case of dots, the width in the short direction in the case of lines, and the shortest distance between adjacent openings in the case of having a shape with openings. . Specifically, the size in plan view is indicated by g in FIGS. 5 and 6.

The type of the thick film member can be appropriately selected according to the shape in plan view. For example, a columnar thick film member obtained by forming the constituent material of the thick film member into a pattern can be used. . As the type of the thick film member, a bead-shaped thick film member that is dispersed and disposed on the surface of the base material can be used when the shape in plan view is a dot shape. 5 and 6 which have already been described show an example in which the type of the thick film member is a columnar thick film member.

As the constituent material of the columnar thick film member, a resin material such as a cured product of a photosensitive resin can be used. As such a photosensitive resin, for example, an ultraviolet curable resin used for forming a thick film member of a liquid crystal display device such as Japanese Patent No. 2953594 can be used.

As the method for forming the columnar thick film member, any method can be used as long as it is obtained by forming the constituent material of the thick film member into a pattern. For example, the method for forming the thick film member described in Japanese Patent No. 2953594 is used. Can do. More specifically, when the constituent material is a cured product of a photosensitive resin, the above-described forming method forms a coating film of the photosensitive resin on the surface on which the fine particles of the high refractive index layer are arranged. A method of exposing the coating film through a photomask and removing the uncured photosensitive resin by development processing can be mentioned. In addition, the forming method includes preparing a transfer substrate having a columnar thick film member disposed on the surface of the support substrate, and bringing the transfer substrate into contact with the high refractive index layer, thereby causing the columnar thick film member to have the high refractive index. You may form using the transfer method which transfers to a rate layer.

The columnar thick film member is preferably bonded and fixed to the surface of the high refractive index layer.

The constituent material of the bead-like thick film member is not particularly limited as long as it has a desired strength. It can be. Specifically, an inorganic material such as glass or a resin material such as an acrylic resin can be used as the constituent material.

The method for forming the beaded thick film member may be any method as long as it is disposed on the surface of the high refractive index layer by spraying the beaded thick film member. For example, the dispersion containing the beaded thick film member is highly refracted. The method of apply | coating on a rate layer and drying and removing a dispersion medium can be used. As the dispersion liquid, one containing the fine particles and a binder agent can be used, and the forming method may be a method in which the thick film member and the binder layer in which the fine particles are dispersed are simultaneously arranged.

The bead-like thick film member may be movably arranged on the surface of the high refractive index layer, or may be bonded and fixed to the surface of the high refractive index layer.

(B) Second Embodiment The second embodiment of the thick film member is used as a spacer for supporting the cover layer.

The height and spacing of the thick film member may be any material that supports the cover layer so that the finger does not touch the fine particles when the user touches the plasmon resonance laminate.

The height may be, for example, at least a distance at which the near-field light of the fine particles is sufficiently attenuated, and can be supported at a position that is at least twice as high as the average primary particle size of the fine particles. More specifically, when it is intended to protect fine particles having an average primary particle size h = 0.08 μm against the skin of a human fingertip, the height is within a range of 0.16 μm to 300 μm. It can be.

The distance is preferably one that can be supported without bending the cover layer, and is appropriately selected in consideration of the thickness of the cover layer and the Young's modulus of the material. More specifically, the interval can be set within a range of 10 μm to 5000 μm, for example.

The above height and interval are specifically indicated by e and f in FIG.

In addition, about the content of the planar view shape of a spacer, planar view size, a kind, a constituent material, a formation method, etc., it can be set as the content similar to the content as described in the said "(a) 1st embodiment." .

(2) Cover layer The cover layer is supported by a thick film member and covers fine particles.

The cover layer is usually light transmissive so that the light can be transmitted. Further, the light-transmitting material may be any material that transmits at least light having a wavelength scattered by plasmon resonance, but preferably has visible-light transmittance that transmits the entire visible light. . This is because the degree of freedom in selecting the material constituting the cover layer is increased. The light transmittance and the total light transmittance of such a cover layer can be the same as those described in the above section “3. Transparent substrate”.

As the constituent material, structure, rigidity, and thickness of the cover layer, any material may be used as long as it exhibits a strength that does not break when a user touches the plasmon resonance laminate. It can be the same as the constituent material described in the item.

The cover layer only needs to be supported by the thick film member, and may be bonded to the thick film member or may not be bonded. Moreover, when not adhering to a thick film member, a cover layer is normally fixed with respect to a transparent base material by arbitrary fixing means. Examples of the fixing means include a resin sealing member disposed so as to cover the outer periphery of the cover layer and the transparent substrate.

The cover layer may be formed by any method as long as the cover layer is supported by the thick film member and can be disposed so as to cover the fine particles. For example, after the thick film member is disposed on the surface of the high refractive index layer, A method of disposing a cover layer on the surface of the thick film member opposite to the high refractive index layer can be used. Alternatively, a method of arranging the laminate on the high refractive index layer so that the surface of the high refractive index layer and the thick film member are in contact after the thick film member is bonded to the surface of the cover layer may be used. it can. As a method for adhering the thick film member to the cover layer surface, a method of forming a columnar thick film member directly on the cover layer surface or a method of adhering the thick film member via an adhesive layer can be used.

(3) Others As the above-mentioned other configurations, there are adhesive layers for bonding the respective components such as a transparent substrate and a high refractive index layer, a transparent substrate and a thick film member, a thick film member and a cover layer. Also good. Examples of the adhesive layer include a pressure-sensitive adhesive layer formed using a known pressure-sensitive adhesive such as an acrylic resin, a two-component curable adhesive layer, an ultraviolet curable adhesive layer, a thermosetting adhesive layer, and heat melting. A known adhesive layer such as a mold adhesive layer can be used.

5). Plasmon Resonance Laminate Applications of the plasmon resonance laminate of the present disclosure include applications that require designability and anti-counterfeiting properties, such as banknotes and other vouchers; identification cards such as driver's licenses and passports. A card such as a credit card. Specifically, the plasmon resonance laminate of the present disclosure can be incorporated into an information recording medium. The information recording medium will be described later. As a method for preventing forgery using the plasmon resonance laminate, a method using a device capable of detecting visible light, such as a charge coupled device (CCD), may be used in addition to a method for visually confirming. it can.

As a method for producing the plasmon resonance laminate of the present disclosure, any method can be used as long as the above-described configurations can be arranged with high accuracy. Preferably, the method described in “C. Method for producing plasmon resonance laminate” described later is used. Can be used.

B. Next, the binder part forming composition of the present disclosure will be described. The composition for forming a binder part of the present disclosure includes fine particles, a binder agent, and a dispersion medium. The fine particles include a negative dielectric material, plasmon-resonates with visible light, and the concentration of the binder agent with respect to the dispersion medium ( The binder agent / dispersion medium) is in the range of 0.1 / 100 or more and 10/100 or less.

According to the present disclosure, since the concentration of the binder agent with respect to the dispersion medium is within the above-described range, the binder layer in which the state of the fine particles is in the state described in the above section “A. Plasmon Resonance Laminate” is easily obtained. Can be formed. Therefore, the composition for forming a binder part of the present disclosure is applied, for example, on the surface of a high refractive index layer of a laminate in which a transparent base material and a high refractive index layer are laminated in this order to form a binder part. By doing so, it is easy to provide designability, anti-counterfeiting properties, etc., and it is possible to easily manufacture a plasmon resonance laminate that is excellent in durability. Moreover, by including a binder agent, when removing a dispersion medium from the coating film of the said binder part formation composition by drying, it can suppress that microparticles | fine-particles aggregate. Therefore, the binder part forming composition can easily form a binder layer in which fine particles are dispersed with good dispersibility.

The binder part forming composition of the present disclosure includes fine particles, a binder agent, and a dispersion medium. Hereinafter, each component of the composition for forming a binder part of the present disclosure will be described in detail. The fine particles are the same as those described in the above section “A. Plasmon Resonance Laminate 1. Binder Part (3) Fine Particles”, and the description thereof is omitted here.

1. Mixing ratio The fine particles and the binder agent in the present disclosure are dispersed or dissolved in a dispersion medium.

As the concentration of the binder agent with respect to the dispersion medium (binder agent / dispersion medium), when the binder part forming composition of the present disclosure is applied, the dispersion medium is dried and removed from the coating film, and the binder part is formed. Any binder layer and fine particles can be used as long as they can be in the above-described state. For example, the binder layer and the fine particles can be in a range of 0.1 / 100 or more and 10/100 or less. It is preferably within the range of 100 or more and 5/100 or less, and particularly preferably within the range of 0.5 / 100 or more and 2/100 or less. It is because it is easy to make the state of a binder layer and fine particles into the above-mentioned state by the said density | concentration being in the above-mentioned range.

In addition, the density | concentration (binder agent / dispersion medium) with respect to the dispersion medium of a binder agent means the volume ratio (binder agent / dispersion medium) with respect to the dispersion medium of a binder agent. Specifically, the concentration of the binder agent relative to the dispersion medium refers to the volume ratio of the binder agent to the dispersion medium at 25 ° C. and atmospheric pressure before mixing. The same may be said of the density | concentration with respect to the dispersion medium of the below-mentioned fine particle.

The volume of the binder agent and the dispersion medium is a method of separating the binder agent and the dispersion medium from the binder part forming composition and measuring the volume ratio at 25 ° C. and atmospheric pressure, respectively. Can be used.

Here, the method for separating the binder agent and the dispersion medium from the binder part forming composition is not particularly limited as long as the binder agent and the dispersion medium can be separated with high accuracy. As a method for separating the dispersion medium from the binder part forming composition, for example, GC-MS (Gas Chromatography Mass Spectrometer) can be used. In addition, as a method for separating the binder agent from the binder part forming composition, GC-MS or HPLC (high performance liquid chromatography) can be used. In the case of HPLC, more specifically, when the dispersion medium is an organic solvent, separation is performed in a normal phase mode (for example, a silica gel column is used for the stationary phase and an organic solvent is used for the mobile phase). In the case of (2), the separation can be performed in the reverse phase mode (for example, a column of ODS-modified silica gel is used for the stationary phase and water / methanol is used for the mobile phase). In HPLC, as a detector used for detecting a dispersion medium and a binder agent, for example, an ultraviolet-visible spectrophotometer can be used.

The method for measuring the volume of each of the binder agent and the dispersion medium is not particularly limited as long as it can accurately measure the volume of the separated binder agent and dispersion medium. For example, (a) About the separated binder agent and dispersion medium, respectively, a method of directly measuring at 25 ° C. and atmospheric pressure, (b) measuring each mass, and calculating from the density (document values and measured values of bulk). The method can be used. In addition, as a method for measuring the volume of the binder agent and the dispersion medium, the components of the binder agent and the dispersion medium are known, but for example, when it is difficult to separate both of them so that the volume can be measured, etc. For example, a mixed solution of a binder agent and a dispersion medium is prepared in a plurality of levels by changing the volume ratio, a calibration curve is prepared by HPLC or the like, and the calibration curve and measurement of the binder portion forming composition by HPLC or the like are prepared. You may use the method of calculating | requiring a result by comparing.

As the concentration of the fine particles with respect to the dispersion medium (fine particles / dispersion medium), that is, the volume ratio of the fine particles to the dispersion medium (fine particles / dispersion medium), the binder part forming composition of the present disclosure is applied, and the coating film When the dispersion medium is removed by drying to form a binder part, the dispersion medium can be appropriately set according to the density of fine particles dispersed in the binder layer. Specifically, the concentration (fine particles / dispersion medium), that is, the volume ratio (fine particles / dispersion medium) can be in the range of 0.000001 / 100 or more and 10/100 or less.

2. Dispersion medium The dispersion medium used in the present disclosure disperses or dissolves each component such as fine particles and a binder agent. As such a dispersion medium, for example, water, an organic solvent, and a mixture thereof can be used.

Examples of the organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, glycerol and other alcohols, toluene, xylene and other aromatic hydrocarbons, acetone, Ketones such as methyl ethyl ketone and methyl isobutyl ketone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, esters such as propylene glycol monomethyl ether acetate (PGMEA), tetrahydrofuran, dioxane, ethylene glycol monomethyl ether (methyl cellosolve) , Ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monobutyl ether (butyl cello Ethers such as cellosolve), hexane, decane, dodecane, aliphatic hydrocarbons tetradecane, alicyclic hydrocarbons such as cyclohexane and the like. In the present disclosure, it is particularly preferable that the organic solvent is an alcohol or an aromatic hydrocarbon. This is because it is easy to disperse or dissolve the binder agent by using the organic solvent.

3. Binder Agent Regarding the binder agent, it is possible to easily form a binder layer in which the state of fine particles is the above-described state when the binder portion is formed using the binder portion forming composition of the present disclosure. That's fine. Such a binder agent can be the same as that described in the above section “A. Plasmon Resonance Laminate 1. Binder Part (2) Binder Layer”.

Further, as the binder agent, when the binder agent is a polymer in which the monomer component is polymerized, the binder agent may be included as a polymer, or a binder agent capable of constituting a polymer as a binder agent. It may be included as a monomer component.

Specifically, as the monomer component of the binder agent, for example, a siloxane having a three-dimensional network structure such as a silicone monomer or silicone oligomer when the binder agent is a silicone resin, or a silicone monomer when the binder agent is a silicone oligomer. Examples thereof include those having a silanol group or an alkoxysilyl group for constituting a bond.

As the monomer component, when the binder agent is a cross-linked product of a silicone compound having a reactive function such as a polymerizable group or a fluorine-based compound having a UV reactive group, the reactive function before the cross-linked product is formed. Examples thereof include a silicone compound having UV and a fluorine compound having a UV reactive group.

In addition, examples of the monomer component include monomer components capable of constituting the resin material by polymerization when the binder agent includes the resin material. As the monomer component of the resin material, for example, when the resin material is an acrylic resin, a urethane acrylic resin, an epoxy acrylate resin, or the like, a monofunctional acrylate monomer, a urethane acrylate monomer, an epoxy acrylate monomer, or a polyfunctional monomer, respectively. Monomer components having a methacrylic group and an acrylic group, such as acrylate monomers, urethane acrylate monomers, and epoxy acrylate monomers.

Further, the monomer component may form a polymer by any curing method such as UV curing type, EB curing type, and thermosetting type. Furthermore, the monomer component may be a monofunctional monomer component having one polymerizable group, reactive group, or the like, or a polyfunctional monomer component having two or more reactive groups. Good.

4). Other components Although the composition for binder part formation of this indication contains fine particles, a binder agent, and a dispersion medium, it may contain other components as needed. Examples of the other components include other components described in the section “A. Plasmon Resonance Laminate 1. Binder Part (2) Binder Layer”.

In addition, when the binder agent is included as a monomer component of the binder agent, a polymerization initiator or the like for use in polymerization may be included as the other components. In addition, about a polymerization initiator, well-known polymerization initiators, such as a photoinitiator and a thermal-polymerization initiator, can be used according to the kind etc. of monomer component. Moreover, as a polymerization initiator of the monomer component having a silanol group or an alkoxysilyl group, for example, a curing catalyst in which polymerization proceeds at room temperature may be used.

5). Binder part forming composition The manufacturing method of the binder part forming composition of the present disclosure may be any method that can mix the above-described components so as to obtain a desired blending amount. These components can be added to the dispersion medium sequentially or simultaneously and mixed.

The binder part forming composition may be a curable binder part forming composition containing a monomer component of the binder agent as the binder agent. Examples of the curable binder part forming composition include, for example, a photocurable binder part forming composition capable of forming a polymer by polymerizing the monomer component of the binder agent by light irradiation, and heating the binder. It can be set as the thermosetting binder part formation composition etc. which the monomer component of an agent can superpose | polymerize and can form a polymer. Further, the curable binder part forming composition may be cured at room temperature.

C. Method for Manufacturing Plasmon Resonance Laminate Next, a method for manufacturing a plasmon resonance laminate of the present disclosure will be described. The manufacturing method of the plasmon resonance laminate of the present disclosure provides a laminate in which a high refractive index layer having a refractive index higher than that of the transparent substrate is formed on one surface of the transparent substrate, On the surface of the high refractive index layer, a coating step of applying a binder part forming composition containing fine particles, a binder agent and a dispersion medium, and drying and removing the dispersion medium from the coating film of the binder part forming composition, A drying step of forming a binder part, wherein the fine particles include a negative dielectric material and plasmon-resonate with respect to visible light, and the binder part forming composition is based on the dispersion medium of the binder agent. The concentration (binder agent / dispersion medium) is in the range of 0.1 / 100 to 10/100.

Such a plasmon resonance laminate manufacturing method of the present disclosure will be described with reference to the drawings. FIG. 7 is a process diagram illustrating an example of a method for producing a plasmon resonance laminate according to the present disclosure. As illustrated in FIG. 7, in the method for manufacturing a plasmon resonance laminate according to the present disclosure, a high refractive index layer 2 having a higher refractive index than that of the transparent substrate 1 is formed on one surface of the transparent substrate 1. A laminate is prepared, and a binder part forming composition 20a containing fine particles, a binder agent and a dispersion medium is applied onto the surface of the high refractive index layer 2 of the laminate (FIG. 7 (a)), and the binder By heating the coating film 20b of the part forming composition, the dispersion medium is dried and removed from the coating film 20b (FIG. 7B), and the binder part 7 including the binder layer 3 and the fine particles 4, that is, the fine particles 4 This is a method of obtaining the plasmon resonance laminated body 10 by forming the binder layer 3 in which is dispersed (FIG. 7C). The fine particles contain a negative dielectric material and plasmon-resonate with visible light. The binder part forming composition has a concentration of the binder agent with respect to the dispersion medium (binder agent / dispersion medium). Is within the above-mentioned range. 7A and 7B show the coating process, and FIGS. 7B and 7C show the drying process.

According to the present disclosure, by performing the coating step and the drying step using the binder part forming composition, the binder is in the state described in the section “A. Plasmon Resonance Laminate”. Layers can be easily formed. Therefore, the manufacturing method of the present disclosure can easily provide a plasmon resonance laminate that is easily imparted with designability, anti-counterfeiting properties, and the like and excellent in durability.

The manufacturing method of the plasmon resonance laminated body of this indication has a coating process and a drying process. Hereinafter, each process of the manufacturing method of the plasmon resonance laminated body of this indication is demonstrated in detail.

1. Coating process The coating process in this indication prepares the layered product by which the high refractive index layer whose refractive index is higher than the above-mentioned transparent substrate was formed in one side of a transparent substrate, and the above-mentioned high of the above-mentioned layered product In this step, a binder part forming composition containing fine particles, a binder agent and a dispersion medium is applied onto the surface of the refractive index layer.

As a method of applying the binder part forming composition on the surface of the high refractive index layer of the laminate in this step, any method can be used as long as it can be applied to a place where a binder layer in which fine particles are dispersed is formed. For example, various printing methods such as ink jet method, micro contact printing method, screen printing, gravure printing, offset printing, flexographic printing, and coating methods such as die coating method, spray coating method, spin coating method, dip coating method, etc. Can be mentioned. In this step, when the plan view shape of the binder layer is a pattern shape, the application method is preferably a method of applying the binder part forming composition to the pattern shape, more specifically. Is preferably the printing method described above.

In addition, the laminated body used for this process has a transparent base material and a high refractive index layer. Such a transparent base material and a high refractive index layer can be the same as the contents described in the above-mentioned section “A. Plasmon Resonance Laminate”, and thus description thereof is omitted here. Further, the binder part forming composition used in this step can be the same as that described in the above section “B. Binder part forming composition”, and thus the description thereof is omitted here.

2. Drying Step The drying step in the present disclosure is a step of forming the binder part by drying and removing the dispersion medium from the coating film of the binder part forming composition.

Here, as a method of drying and removing the dispersion medium from the coating film, a general drying method can be used. Examples thereof include a method of heating the coating film, a method of blowing hot air, and a method of reducing the pressure. it can. Moreover, the said drying method may use only one type of method, and may use 2 or more types of methods together.

In this step, when the binder component monomer component is included as the binder agent contained in the binder part forming composition, that is, when the binder part forming composition is a curable binder part forming composition, It is preferable to perform a polymerization treatment that polymerizes monomer components to form a binder agent as a polymer. Here, as a method for the polymerization treatment, when the curable binder part forming composition is a photocurable binder part forming composition, a method of performing light irradiation can be exemplified. When the composition is a composition for forming a thermosetting binder part, a heating method can be mentioned. In addition, about a light irradiation method and a heating method, it can be made to be the same as that of the hardening method of a general photocurable resin and a thermosetting resin. In addition, when the monomer component of the binder agent is cured at room temperature in the presence of a catalyst, a method of leaving it at room temperature for a predetermined time may be used as the polymerization treatment.

The binder portion formed by this process includes a binder layer and fine particles. The binder layer includes a binder agent and fine particles are dispersed. Such a binder layer and fine particles, and the state of the fine particles dispersed in the binder layer can be the same as the contents described in the above section “A. Plasmon Resonance Laminate”. Is omitted.

3. Other Steps The method for producing a plasmon resonance laminate of the present disclosure includes a coating step and a drying step, but may include other steps as necessary. For example, a columnar thick film member forming step for forming a columnar thick film member, a cover layer forming step for forming a cover layer, and the like can be given.

D. Information Recording Medium Next, the information recording medium of the present disclosure will be described. The information recording medium of the present disclosure has a high refractive index layer having a higher refractive index than the transparent substrate on one surface of the transparent substrate, and the opposite side of the high refractive index layer from the transparent substrate. And a binder part including a binder layer and particles, the particles contain a negative dielectric material, and plasmon resonate with visible light, and the binder part is located above the transparent substrate. When it does, at least one part of the surface on the opposite side to the said transparent base material of the said binder part is equipped with the plasmon resonance laminated body lower than the part most distant from the said transparent base material of the said particle | grain. That is, the information recording medium of the present disclosure includes the above-described plasmon resonance laminated body.

The information recording medium of the present disclosure can improve anti-counterfeiting by including the above-described plasmon resonance laminate. The plasmon resonance laminate can display images of different colors when irradiated with visible light from the front side of the information recording medium and when irradiated with visible light from the back side. In addition, the plasmon resonance laminate can display images including information such as characters, symbols, and patterns, and can display images including predetermined information in different colors on the front and back of the information recording medium. Therefore, it is possible to determine the authenticity of the information recording medium by irradiating the information recording medium with visible light from both sides and checking the images displayed by the plasmon resonance laminate on the front and back of the information recording medium.

Hereinafter, each configuration of the information recording medium of the present disclosure will be described.

1. Plasmon Resonance Laminate The plasmon resonance laminate can display an image including information on characters, symbols, and patterns, for example. Specifically, the plasmon resonance laminate can display images including predetermined information in different colors on the front and back of the information recording medium.

The plasmon resonance laminated body may be disposed on the outermost surface of the information recording medium, may be disposed between the members constituting the information recording medium, and is fitted into the opening of the member constituting the information recording medium. It may be. The information recording medium usually includes a support on at least one surface side of the plasmon resonance laminate. When the information recording medium includes a support, for example, as shown in FIGS. 8, 9A, 9B, 10, and 11A, the

information recording media

30A and 30B have one support 31. And the plasmon resonance laminate 10 may be disposed on one surface side of the support 31 as shown in FIGS. 8, 9 (c), 9 (d), 10, and 11 (b). As described above, the

information recording media

30A and 30B include two supports, that is, the first support 31a and the second support 31b, and the plasmon resonance laminate 10 is disposed between the first support 31a and the second support 31b. As shown in FIG. 8, FIG. 9 (e), and FIG. 9 (f), the support 31 constituting the information recording medium 30A has an opening 32, and a plasmon resonance lamination is formed in the opening 32. The body 10 may be fitted. 9A to 9F are sectional views taken along the line DD of FIG. 8, and FIGS. 11A to 11B are sectional views taken along the line EE of FIG. 8 to 11 will be described later.

When the plasmon resonance laminated body is arranged on the outermost surface of the information recording medium, specifically, the information recording medium includes one support, and the plasmon resonance laminated body is arranged on one surface side of the support. In this case, the plasmon resonance laminate may be separately disposed on one surface side of the support, and the transparent substrate of the plasmon resonance laminate may be integrated with the support. In addition, that the transparent base material of a plasmon resonance laminated body is integral with a support means that the transparent base material of a plasmon resonance laminated body also functions as a support body.

When the plasmon resonance laminate is disposed on the outermost surface of the information recording medium, specifically, as shown in FIGS. 9A, 9B, and 11A, the

information recording media

30A and 30B are used. Is provided with one support 31, and the plasmon resonance laminate 10 is disposed on one surface side of the support 31, and the plasmon resonance laminate 10 is a thick film as shown in FIG. 5B, for example. When the member 5 and the cover layer 6 are provided, the arrangement of the plasmon resonance laminate is not particularly limited, and the transparent substrate side of the plasmon resonance laminate may be arranged on the support side of the information recording medium. The cover layer side of the plasmon resonance laminate may be disposed on the support side of the information recording medium. On the other hand, in the above case, when the plasmon resonance laminate does not have a cover layer, the transparent substrate side of the plasmon resonance laminate is disposed on the support side of the information recording medium. With such an arrangement, the fine particles of the plasmon resonance laminate can be prevented from coming into contact with the support, and in the plasmon resonance laminate, the refractive index difference on the surface opposite to the transparent substrate of the fine particles is increased. Can do.

Further, when the plasmon resonance laminated body is disposed between the members constituting the information recording medium, specifically, as shown in FIGS. 9 (c), 9 (d), and 11 (b), information is provided. When the

recording media

30A and 30B include two supports, that is, the first support 31a and the second support 31b, and the plasmon resonance laminate 10 is disposed between the first support 31a and the second support 31b. And when the plasmon resonance laminated body 10 has the thick film member 5 and the cover layer 6 as shown, for example in FIG.5 (b), as arrangement | positioning of a plasmon resonance laminated body, it does not specifically limit. On the other hand, in the above case, when the plasmon resonance laminate does not have a cover layer, so that there is a space between the surface of the plasmon resonance laminate opposite to the transparent substrate and the support, A plasmon resonance laminate is disposed. With such an arrangement, the fine particles of the plasmon resonance laminate can be prevented from coming into contact with the support, and in the plasmon resonance laminate, the refractive index difference on the surface opposite to the transparent substrate of the fine particles is increased. Can do. For example, when the information recording medium includes a support having an opening as described later, a part of the plasmon resonance laminate overlaps with the opening of the support in a plan view, and the transparent substrate of the plasmon resonance laminate The plasmon resonance laminate can be arranged so as to have a space between the opposite surface and the opening of the support. For example, in the information recording medium 30A shown in FIG. 9D, a space 40 is formed between the surface of the plasmon resonance laminate 10 opposite to the transparent substrate and the opening 32 of the first support 31a. Thus, the plasmon resonance laminated body 10 is arrange | positioned.

Further, when the plasmon resonance laminated body is fitted in the opening of a member constituting the information recording medium, specifically, as shown in FIGS. 9 (e) and 9 (f), the information recording medium 30A is provided. The support 31 to be configured has an opening 32, and the plasmon resonance laminated body 10 is fitted into the opening 32, and the plasmon resonance laminated body 10 has a thickness as shown in FIG. 5B, for example. When the membrane member 5 and the cover layer 6 are provided, the arrangement of the plasmon resonance laminate is not particularly limited. On the other hand, in the above case, when the plasmon resonance laminate does not have a cover layer, the plasmon resonance laminate is arranged so that the surface of the plasmon resonance laminate opposite to the transparent substrate is in contact with the air layer. Is done. For example, by arranging the plasmon resonance laminate so that the surface opposite to the transparent substrate of the plasmon resonance laminate fitted in the opening of the support faces the outside, the transparent substrate of the plasmon resonance laminate The surface on the opposite side can be in contact with the air layer. In addition, in the opening of the support, the surface of the plasmon resonance laminate that is fitted in the opening of the support is the side that is opposite to the transparent substrate, and the layer that constitutes the support, and does not have an opening. By disposing the plasmon resonance laminate so that there is a space between the layers, the surface of the plasmon resonance laminate opposite to the transparent substrate can be in contact with the air layer. With such an arrangement, the fine particles of the plasmon resonance laminate can be prevented from coming into contact with the support, and in the plasmon resonance laminate, the refractive index difference on the surface opposite to the transparent substrate of the fine particles is increased. Can do.

As will be described later, when the information recording medium further includes a support having an opening, it is preferable that at least a part of the plasmon resonance laminate overlaps the opening in plan view. This is because it becomes easier to observe the image displayed by the plasmon resonance laminate from the opening. Moreover, it is because a plasmon resonance laminated body can be applied to various information recording media.

When at least a part of the plasmon resonance laminate overlaps with the opening of the support in plan view, the entire plasmon resonance stack may overlap with the opening of the support in plan view. A part of the opening may overlap the opening of the support in plan view. Moreover, the plasmon resonance laminated body may be arrange | positioned in the whole region of the opening part of a support body, and may be arrange | positioned in a part of opening part of a support body.

As a method of arranging the plasmon resonance laminate on one surface side of the support, for example, a method of adhering the support and the plasmon resonance laminate via an adhesive layer, the plasmon resonance laminate is arranged on the support Thereafter, there is a method of fusing the support and the plasmon resonance laminate by applying heat or pressure. Moreover, as a method of disposing a plasmon resonance laminate between two supports, for example, a method of adhering at least one support and a plasmon resonance laminate via an adhesive layer, between the two supports A method of arranging a plasmon resonance laminate and bonding two supports via an adhesive layer. After arranging a plasmon resonance laminate between two supports, two supports by applying heat or pressure And a method of fusing. The adhesive layer can be the same as the adhesive layer used in the plasmon resonance laminate described above. Moreover, in the case of the method of fitting a plasmon resonance laminated body in the opening part of a support body, the plasmon resonance laminated body of the same shape as an opening part is used.

Since the plasmon resonance laminated body is described in detail in the above-mentioned section “A. Plasmon Resonant Laminate”, description thereof is omitted here.

2. Support The information recording medium usually has a support on at least one surface side of the plasmon resonance laminate.

As described above, the information recording medium includes one support body 31 as shown in FIGS. 9A, 9B, and 11A, and the plasmon resonance laminate 10 is one of the support bodies 31. As shown in FIGS. 9C, 9D, and 11B, the

information recording media

30A and 30B include two supports, and a plasmon resonance laminated body 10 may be disposed between the two supports, that is, between the first support 31a and the second support 31b, and includes the support 31 as shown in FIGS. 9 (e) and 9 (f). The plasmon resonance laminate 10 may be fitted into the opening 32 of the support 31. Further, as described above, the transparent substrate of the plasmon resonance laminate may be integral with the support.

The support may or may not have transparency. When the support has transparency, it usually has the same light transmittance as that of the transparent substrate of the plasmon resonance laminate, and can have the same visible light transmittance as that of the transparent substrate. .

Further, the support may have an opening. When a support body does not have transparency, it is preferable to have an opening. The opening is provided for observing an image displayed by the plasmon resonance laminate from both sides of the information recording medium. At least a part of the plasmon resonance laminated body is disposed so as to overlap the opening of the support in plan view.

The support only needs to have a support layer, for example, may have only a support layer, or may have a functional layer on at least one surface side of the support layer. When the support has a support layer and a functional layer, the support may have one support layer and one functional layer, or may have a plurality of at least one of the support layer and the functional layer.

Examples of the material for the support layer and the functional layer include paper, resin, metal, and synthetic fiber. As the support layer, the transparent substrate of the plasmon resonance laminate described above can also be used. Moreover, as a functional layer, an opaque layer, a printing layer, an image receiving layer, a hologram layer etc. are mentioned, for example.

When the support has an opening, the support layer may have an opening, the functional layer may have an opening, and the support layer and the functional layer may have an opening. .

When the functional layer has an opening, the opening of the functional layer may be a hole, and a transparent layer having the same shape as the opening may be fitted into the opening of the functional layer. The transparent layer usually has the same light transmittance as that of the transparent substrate of the plasmon resonance laminate described above, and can further have the same visible light transmittance as that of the transparent substrate.

The size of the opening is not limited as long as at least a part of the plasmon resonance laminate can be arranged so as to overlap the opening in plan view, and depends on the size of the plasmon resonance laminate, the size of the information recording medium, and the like. Are adjusted accordingly.

The thickness of the support is appropriately selected according to the use and type of the information recording medium, and can be, for example, in the range of 10 μm to 2000 μm, and more preferably in the range of 50 μm to 1000 μm.

Examples of the method of arranging the functional layer on at least one side of the support layer include, for example, a method of bonding the support layer and the functional layer through an adhesive layer, and fusing the support layer and the functional layer by applying heat or pressure. And a method of forming a functional layer on the support layer. Further, when the support has a plurality of support layers, the method of laminating the plurality of support layers is, for example, a method of bonding a plurality of support layers via an adhesive layer, a plurality of support layers by applying heat or pressure, etc. And the like. In this case, a functional layer may be disposed between the support layers. The adhesive layer can be the same as the adhesive layer used in the plasmon resonance laminate described above.

An example is given and demonstrated about the case where a support body has a support layer and a functional layer. 8 to 11 are examples in which the support has a support layer and a functional layer. 9A to 9F are sectional views taken along the line DD of FIG. 8, and FIGS. 11A to 11B are sectional views taken along the line EE of FIG. Each example will be described below.

The information recording medium 30A shown in FIG. 8 and FIG. 9A includes a single support 31, and the plasmon resonance laminate 10 is disposed on one surface side of the support 31. In the support 31, the first support layer 33, the opaque layer 34, and the second support layer 35 are sequentially stacked. The opaque layer 34 has an opening 32, and the plasmon resonance laminated body 10 is disposed so as to overlap the opening 32 in plan view. In this example, the plasmon resonance laminate 10 is disposed on the surface of the support 31 on the second support layer 35 side, but the plasmon resonance laminate 10 is disposed on the surface of the support 31 on the first support layer 33 side. It may be arranged.

The information recording medium 30A shown in FIG. 8 and FIG. 9B includes a single support 31, and the plasmon resonance laminate 10 is disposed on one surface side of the support 31. In the support 31, the first support layer 33, the first print layer 36, the second support layer 35, the second print layer 37, and the third support layer 38 are laminated in order. The first print layer 36 and the second print layer 37 each have an opening 32, and the plasmon resonance laminate 10 is disposed so as to overlap the opening 32 in plan view. In this example, the plasmon resonance laminate 10 is disposed on the surface of the support 31 on the third support layer 38 side, but the plasmon resonance laminate 10 is disposed on the surface of the support 31 on the first support layer 33 side. It may be arranged.

The information recording medium 30A shown in FIGS. 8 and 9C includes two supports, that is, a first support 31a and a second support 31b, and is provided between the first support 31a and the second support 31b. Plasmon resonance laminate 10 is arranged. In the first support 31a, the first support layer 33 and the opaque layer 34 are sequentially laminated. Further, the second support 31 b has a second support layer 35. The opaque layer 34 has an opening 32, and the plasmon resonance laminated body 10 is disposed so as to overlap the opening 32 in plan view.

The information recording medium 30A shown in FIGS. 8 and 9D includes two supports, that is, a first support 31a and a second support 31b, and is provided between the first support 31a and the second support 31b. Plasmon resonance laminate 10 is arranged. In the first support 31a, the first support layer 33 and the opaque layer 34 are sequentially laminated. In the second support 31b, the second support layer 35 and the print layer 39 are sequentially stacked. The opaque layer 34 and the printed layer 39 each have an opening 32, and the plasmon resonance laminate 10 is disposed so as to overlap the opening 32 in plan view. In this example, the printed layer 39 is disposed on the plasmon resonance laminate 10 side of the second support layer 35, but is disposed on the opposite side of the plasmon resonance laminate 10 of the second support layer 35. Also good.

The information recording medium 30A shown in FIG. 8 and FIG. 9 (e) includes one support 31, and the plasmon resonance laminate 10 is fitted in the opening 32 of the support 31. In the support 31, the first support layer 33, the opaque layer 34, and the second support layer 35 are sequentially stacked. Each of the second support layer 35 and the opaque layer 34 has an opening 32, and the plasmon resonance laminate 10 is fitted into the opening 32 of the second support layer 35.

The information recording medium 30A shown in FIG. 8 and FIG. 9 (f) includes a single support 31, and the plasmon resonance laminate 10 is fitted into the opening 32 of the support 31. In the support 31, the first support layer 33, the first print layer 36, the second support layer 35, the second print layer 37, and the third support layer 38 are laminated in order. The third support layer 38, the first print layer 36, and the second print layer 37 each have an opening 32, and the plasmon resonance laminate 10 is fitted into the opening 32 of the third support layer 38.

10 and 11 are examples in which the information recording medium is a banknote. An information recording medium 30 </ b> B shown in FIGS. 10 and 11A includes a single support 31, and the plasmon resonance laminate 10 is disposed on one surface side of the support 31. In the support 31, the first print layer 42 and the second print layer 43 are disposed on both sides of the support layer 41, respectively. Each of the first printed layer 42 and the second printed layer 43 has an opening 32, and the plasmon resonance laminate 10 is disposed so as to overlap the opening 32 in plan view.

The information recording medium 30B shown in FIGS. 10 and 11B includes two supports, that is, a first support 31a and a second support 31b, and is provided between the first support 31a and the second support 31b. Plasmon resonance laminate 10 is arranged. In the first support 31 a, the first print layer 42 is disposed on one side of the first support layer 44. In the second support 31b, the second print layer 43 is disposed on one side of the second support layer 45. Each of the first printed layer 42 and the second printed layer 43 has an opening 32, and the plasmon resonance laminate 10 is disposed so as to overlap the opening 32 in plan view.

3. Information recording medium In the present disclosure, it is possible to determine the authenticity by irradiating the information recording medium with visible light from both sides and confirming the images displayed by the plasmon resonance laminate on the front and back of the information recording medium. It is. The visible light applied to the information recording medium may be any light that includes the wavelength of visible light that causes plasmon resonance, as described in the section “A. Plasmon Resonance Laminate” above. For example, the information recording medium can be irradiated with white light. The method for confirming the image displayed by the plasmon resonance laminate can be the same as the method for preventing forgery using the plasmon resonance laminate.

Examples of the information recording medium include a medium having a monetary value and a medium on which various information such as personal information and confidential information is recorded. Specifically, a bill, a cash voucher, a ticket, an ID card, a passport , Magnetic cards, IC cards, official documents and the like. Examples of the ID card include a national ID card, a driver's license, a membership card, an employee card, and a student card.

The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present disclosure will be described in more detail with reference to examples.

[Comparative Example 1]
An aqueous dispersion (Sigma Aldrich) of 100 nm diameter silver nanoparticles surface-modified with ethylene glycol was fractionated into a centrifuge tube. An excess amount of acetone was added, silver nanoparticles were precipitated with a centrifugal force of 2000 G using a centrifuge, and the supernatant was removed. This was repeated several times and re-dispersed in ethanol to obtain a silver nanoparticle ethanol dispersion. Next, titanium oxide was deposited on a PET film (Lumirror, Toray) by sputtering to form a substrate having a titanium oxide film as a high refractive index layer. It was 40 nm when the film thickness of the high refractive index layer was measured with the stylus type level difference meter. About 1 mL of the silver nanoparticle ethanol dispersion was sprayed on the titanium oxide surface of the substrate with a disposable pipette and dried to obtain a plasmon resonance laminate.

When this plasmon resonance laminate was illuminated with a white halogen lamp and visually observed, different colors were observed on the front and back sides. In addition, when the silver nanoparticle spreading | diffusion surface of the plasmon resonance laminated body was wiped off with the wipe, the color transfer estimated to be attributed to the silver nanoparticle in the wipe was confirmed.

[Example 1]
Silver nanoparticles were redispersed in ethanol, and silicone resin LPS-5558 (Shin-Etsu Chemical Co., Ltd.) was added as a binder agent at a concentration of 1/99 (binder agent / dispersion medium) with respect to ethanol as the dispersion medium. Furthermore, using a silver nanoparticle ethanol dispersion prepared by adding a thermosetting agent C-5558 (Shin-Etsu Chemical Co., Ltd.) as a curing catalyst capable of curing the silicone resin, the binder layer was thermally cured by heating the substrate. Except for the above, a plasmon resonance laminate was obtained in the same manner as in Example 1.

When this plasmon resonance laminate was illuminated with a white halogen lamp and visually observed, different colors were observed on the front and back sides as in Comparative Example 1. Further, when the state of the silver nanoparticles in the binder layer was confirmed by SEM cross-sectional observation, the state of the fine particles dispersed in the binder layer was such that the minimum thickness of the binder layer was thinner than the maximum height of the fine particles, It was confirmed that the fine particles were in contact with the high refractive index layer, and that the average thickness of the binder layer was smaller than the average primary particle size of the fine particles. Further, when the silver nanoparticle-spreading surface of the plasmon resonance laminate was wiped with a wipe, the degree of color transfer was significantly reduced as compared with Comparative Example 1.

DESCRIPTION OF SYMBOLS 1 ... Transparent base material 2 ... High refractive index layer 3 ... Binder layer 4 ... Fine particle 5 ... Thick film member 6 ... Cover layer 7 ... Binder part 10 ... Plasmon resonance laminated

body

30A, 30B ... Information recording medium 31 ... Support 31a ... 1st support 31b ... 2nd support 32 ... Opening part

Claims

On one side of the substrate having transparency, the first layer having a higher refractive index than the substrate,
A second layer including a binder layer and particles on the surface of the first layer opposite to the substrate;
The particles include a negative dielectric material and plasmon resonate with visible light,
When the second layer is positioned above the base material, at least a part of the surface of the second layer opposite to the base material is a part of the particle farthest from the base material. Lower plasmon resonance laminate.
The plasmon resonance laminate according to claim 1, wherein an average thickness of the second layer is smaller than an average primary particle size of the particles.
The plasmon resonance laminate according to claim 1 or 2, wherein the binder agent contains at least one of a fluorine compound and a silicone compound.
Including particles, binder agent and dispersion medium,
The particles include a negative dielectric material and plasmon resonate with visible light,
The composition for binder part formation whose density | concentration (binder agent / dispersion medium) with respect to the said dispersion medium of the said binder agent exists in the range of 0.1 / 100 or more and 10/100 or less.
A laminate having a first layer having a refractive index higher than that of the substrate is prepared on one surface of the substrate having transparency, and particles, a binder agent, and a binder are formed on the surface of the first layer of the laminate. An application step of applying a binder part-forming composition containing a dispersion medium;
A drying step of drying and removing the dispersion medium from the coating film of the binder part forming composition to form a second layer;
Have
The particles include a negative dielectric material and plasmon resonate with visible light,
The binder part forming composition is a method for producing a plasmon resonance laminate, wherein a concentration of the binder agent with respect to the dispersion medium (binder agent / dispersion medium) is in a range of 0.1 / 100 or more and 10/100 or less.
On one side of the substrate having transparency, the first layer having a higher refractive index than the substrate,
A second layer including a binder layer and particles on the surface of the first layer opposite to the substrate;
The particles include a negative dielectric material and plasmon resonate with visible light,
When the second layer is positioned above the base material, at least a part of the surface of the second layer opposite to the base material is a part of the particle farthest from the base material. An information recording medium comprising a lower plasmon resonance laminate.
The information recording medium according to claim 6, wherein the plasmon resonance laminate displays an image including information.
Further comprising a support having an opening,
The information recording medium according to claim 6 or 7, wherein at least a part of the plasmon resonance laminate overlaps the opening of the support in a plan view.