JP6019745B2 - Light control film with conductive material, and method for producing light control film with conductive material - Google Patents

Description

  The present invention relates to a light control film with a conductive material and a method for producing a light control film with a conductive material.

  In the state where no electric field is applied, the Brownian motion of the light control particles dispersed in the suspension causes most of the incident light to be reflected, scattered or absorbed by the light control particles, and only a small part is transmitted. On the other hand, in a state where an electric field is applied, a light valve, that is, a light control device, is known in which light adjusting particles are polarized and arranged parallel to the electric field, and light is transmitted between the light adjusting particles and the light adjusting particles. (For example, refer to Patent Document 1). Robert L. Sax et al. Have proposed a light control film that can be used practically (see, for example, Patent Documents 2 and 3).

  Two transparent conductive resin substrates having a conductive surface such as a conductive layer, a resin matrix sandwiched between two transparent conductive resin substrates, and a light control suspension dispersed in the resin matrix There is a light control film having a structure including a light control layer. However, the polymer resin that hardens to become a resin matrix is not designed with a molecular design that takes into account the adhesion to the transparent conductive resin substrate, so that a conductive thin film such as ITO was formed on the surface. Adhesiveness between a resin substrate such as a PET film and a resin matrix is poor and easily peeled off. In order to improve this, a primer layer made of a silicone compound or the like is provided on a resin substrate such as a PET film to improve the adhesion between the resin substrate and the light control layer (for example, Patent Document 4). reference).

US Pat. No. 1,955,923 US Pat. No. 6,114,405 US Pat. No. 6,900,923 WO2009 / 093657 Pamphlet

  A part of the conductive surface of the transparent conductive resin substrate of the light control film is attached with a lead conductive material (for example, conductive tape) for connection to an external drive power source for driving. An electrode is formed. The drive electrode of the light control film is composed of the other transparent conductive resin substrate facing the portion of the transparent conductive resin substrate that forms the drive electrode (hereinafter abbreviated as drive electrode portion). After cutting and removing the corresponding part, the light control layer on the drive electrode part is removed by scraping, etc., washed with a solvent such as hexane, and then a conductive material is joined to the drive electrode part To do.

  In this case, the resin matrix present on the surface of the primer layer that assists the adhesion between the transparent conductive resin substrate and the light control layer may be a residue that is insufficiently removed by solvent washing alone. As a result, the adhesiveness with the joined conductive material may deteriorate, and the initial adhesive strength may be reduced. Moreover, peeling of the conductive material may occur over time after joining. This peeling of the conductive material may occur even when the primer layer is not formed on the transparent conductive resin substrate.

  The present invention provides an initial adhesion force between a conductive material and a transparent conductive resin substrate, a light control film with a conductive material that is excellent in stability over time of the adhesion strength, and a method for producing a light control film with a conductive material. Let it be an issue.

Specific means for solving the above problems are as follows.
<1> two transparent conductive resin base materials having a conductive surface;
A light control layer that is sandwiched between the two transparent conductive resin substrates and includes a resin matrix and a light control suspension dispersed in the resin matrix;
A conductive material bonded to the conductive surface via a conductive film;
A light control film with a conductive material.
<2> The conductive material according to <1>, wherein the conductive material is at least one selected from the group consisting of a metal foil, a conductive tape, a flexible printed board, and a transparent conductive resin base material having a conductive surface. Light control film with conductive material.
<3> The light control film with a conductive material according to <1> or <2>, wherein the conductive film includes a thermosetting resin and conductive particles.

<4> Two transparent conductive resin base materials having conductive surfaces, and a resin matrix and a light control suspension dispersed in the resin matrix sandwiched between the two transparent conductive resin base materials Any one of <1> to <3>, including a step of thermocompression bonding a conductive material to the surface having conductivity of the transparent conductive resin substrate of the light control film having a light control layer via the conductive film The manufacturing method of the light control film with an electroconductive material of 1 item | term.
<5> The step of thermocompression bonding includes the step of thermocompression bonding the conductive film to the conductive surface of the transparent conductive resin base material, and the conductive material on the conductive film on the transparent conductive resin base material. The manufacturing method of the light control film with a conductive material as described in <4> including the process of thermocompression bonding.
<6> The step of thermocompression bonding includes a surface having conductivity of the transparent conductive resin base material and a laminate of the conductive film and the conductive material, and the conductive film side of the laminate is the transparent conductive. The manufacturing method of the light control film with a conductive material as described in <4> including the process of thermocompression bonding so that the surface which has the electroconductivity of a resin base material may be touched.

  According to the present invention, compared with the case where a conductive material such as a conductive tape is directly applied to the transparent conductive resin base material, the initial adhesion between the conductive material and the transparent conductive resin base material is excellent, and time has passed. There are provided a light control film with a conductive material that is less peeled later and has excellent adhesion strength over time, and a method for producing a light control film with a conductive material.

It is a sectional structure schematic diagram of one mode of a light control film with a conductive material of the present invention. It is sectional drawing which shows an example of the manufacturing method of the light control film with a electrically conductive material of this invention. It is sectional drawing which shows another example of the manufacturing method of the light control film with a electrically conductive material of this invention. It is a figure which shows the thermal deterioration test result of the light control film with a electrically conductive material of this invention, and the light control film which has the conventional electrode structure. It is the cross-sectional structure schematic of the sample used for the comparison of the adhesive force of the drive electrode structure of this invention, and the conventional electrode structure.

  The light control film with a conductive material of the present invention is sandwiched between two transparent conductive resin substrates having conductive surfaces and the two transparent conductive resin substrates, and dispersed in the resin matrix and the resin matrix. A light control layer including the light control suspension, and a conductive material bonded to the conductive surface via a conductive film.

  The light control film with a conductive material of the present invention has the above-described configuration, so that the conductive material and the transparent conductive resin base material are compared with the case where a conductive material such as a conductive tape is directly attached to the transparent conductive resin base material. The initial adhesion strength is excellent, and there is little peeling after a long time, and the adhesion strength is stable over time.

In addition, providing a conductive paste layer on the resin base material as a base layer for the conductive material is more productive than the method for preventing a decrease in the adhesion of the conductive material, which is advantageous in terms of manufacturing cost. This is because, in the present invention, it is not necessary to provide a conductive paste drying step, the time required for bonding the conductive material is short, and the material cost is lower than that of the conductive paste.
In addition, a reduction in light control performance can be suppressed as compared with a method using a conductive paste layer. This is considered to be because, for example, the heating time required for bonding the conductive material to the transparent conductive resin substrate is short, and there is no occurrence of cracks due to vibration stress, and there are few conduction failures.

<Light control layer>
The light control layer can generally be formed using a light control material. The light control material includes a polymer medium that forms a resin matrix and is cured by irradiation with energy rays, and a light control suspension in which the light control particles are dispersed in a flowable state in the polymer medium. To do. It is preferable that the dispersion medium in the light control suspension is capable of phase separation from the polymer medium and its cured product. By using a light control material, a light control film is formed by forming a light control layer in which a light control suspension is dispersed in a resin matrix formed from a polymer medium between two transparent conductive resin base materials. Is obtained. That is, in the light control layer of the light control film, the liquid light control suspension is dispersed in the form of fine droplets in a solid resin matrix in which the polymer medium is cured. The light adjusting particles contained in the light adjusting suspension are preferably rod-shaped or needle-shaped.

  When an electric field is applied to such a light control film, the light control particles having an electric dipole moment suspended and dispersed in the droplets of the light control suspension dispersed in the resin matrix By arranging them in parallel, the droplets are converted to a transparent state with respect to the incident light, and the incident light is transmitted with almost no scattering due to the viewing angle or a decrease in transparency.

(Light control material)
The light control material used for forming the light control layer includes a polymer medium forming a resin matrix and a light control suspension dispersed in the polymer medium. Specifically, first, a liquid in which light adjusting particles are dispersed in a solvent and a dispersion medium of the light adjusting suspension are mixed, and the solvent is distilled off with a rotary evaporator or the like to prepare a light adjusting suspension. Next, the light control suspension and the polymer medium are mixed to obtain a mixed liquid (light control material) in which the light control suspension is dispersed in a droplet state in the polymer medium.

  As the polymer medium and the dispersion medium (dispersion medium in the light control suspension), those in which the polymer medium and the cured product thereof and the dispersion medium can be phase-separated at least when formed into a film are used. It is preferable to use a combination of an incompatible or partially compatible polymer medium and a dispersion medium.

  The polymer medium used in the present invention contains (A) a resin having an ethylenically unsaturated bond and (B) a photopolymerization initiator, and is cured by irradiation with energy rays such as ultraviolet rays, visible rays, and electron beams. Is. (A) As a resin having an ethylenically unsaturated bond, a silicone resin, an acrylic resin, a polyester resin and the like are preferable from the viewpoints of ease of synthesis, light control performance, durability, and the like. These resins are substituted with alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, amyl group, isoamyl group, hexyl group, and cyclohexyl group, and phenyl group. It is preferable to have an aryl group such as a naphthyl group from the viewpoints of light control performance and durability.

  Examples of the silicone-based resin include a bi-terminal silanol polydimethylsiloxane, a bi-terminal silanol polydiphenylsiloxane-dimethylsiloxane copolymer, a bi-terminal silanol siloxane polymer such as a bi-terminal silanol polydimethyldiphenyl siloxane, and a trialkylalkoxysilane such as trimethylethoxysilane. An ethylenically unsaturated bond-containing silane compound such as (3-acryloxypropyl) methyldimethoxysilane is subjected to a dehydrogenative condensation reaction and a dealcoholization reaction in the presence of an organotin catalyst such as 2-ethylhexanetin. Synthesized. As the silicone resin, a solventless type is preferably used. That is, when a solvent is used for the synthesis of the silicone resin, it is preferable to remove the solvent after the synthesis reaction.

  The acrylic resin includes, for example, (meth) acrylic acid alkyl ester, (meth) acrylic acid aryl ester, (meth) acrylic acid benzyl, main chain forming monomers such as styrene, (meth) acrylic acid, (meth) acrylic A prepolymer was synthesized by copolymerizing ethylenically unsaturated bond-introducing functional group-containing monomers such as hydroxyethyl acid, isocyanatoethyl (meth) acrylate, and glycidyl (meth) acrylate. By reacting monomers such as glycidyl (meth) acrylate, isocyanatoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylic acid, etc. to the prepolymer to react with the functional group of the polymer Can be obtained.

The polyester resin can be easily produced by a known method.
The weight-average molecular weight in terms of polystyrene obtained by gel permeation chromatography of the resin having an ethylenically unsaturated bond is preferably 20,000 to 100,000, and preferably 30,000 to 80,000. More preferred.

  The ethylenically unsaturated bond concentration of the resin having an ethylenically unsaturated bond is preferably 0.3 mol / Kg to 0.5 mol / Kg. If this concentration is less than 0.3 mol / Kg, the end of the light control film cannot be easily processed, and the opposing transparent electrodes are likely to be short-circuited, resulting in poor electrical reliability. On the other hand, when the concentration exceeds 0.5 mol / Kg, the cured polymer medium is easily dissolved in the dispersion medium constituting the droplets of the light control suspension, and the dissolved polymer medium adjusts the light in the droplets. There exists a tendency for the light control performance to deteriorate by inhibiting the movement of particles. The ethylenically unsaturated bond concentration of the resin having an ethylenically unsaturated bond can be obtained from the integral intensity ratio of hydrogen in NMR. Further, when the conversion rate of the charged raw material to the resin is known, it can also be obtained by calculation.

  In addition, in the charge mixing of various raw materials at the time of production of the silicone resin, the amount of the ethylenically unsaturated bond-containing silane compound such as (3-acryloxypropyl) methoxysilane is 19 to 50 weight of the total amount of the raw material siloxane and the silane compound. %, Preferably 25 to 40% by weight. When the amount of the ethylenically unsaturated bond-containing silane compound is less than 19% by weight, the ethylenically unsaturated bond concentration of the resin finally obtained tends to be too lower than the desired concentration, and when it exceeds 50% by weight. The resulting resin has an ethylenically unsaturated bond concentration that tends to be too high.

As the photopolymerization initiator, J.M. Photochem. Sci. Technol. , 2, 283 (1977), specifically 2,2-dimethoxy-1,2-diphenylethane-1-one, 1- (4- (2-hydroxyethoxy) phenyl) -2- Hydroxy-2-methyl-1-propan-1-one, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, (1- Hydroxycyclohexyl) phenyl ketone and the like can be used.
It is preferable that the usage-amount of a photoinitiator is 0.1-20 weight part with respect to 100 weight part of said resin, and it is more preferable that it is 0.2-1 weight part.

In addition to the above resins, organic solvent-soluble resins or thermoplastic resins such as polyacrylic acid having a polystyrene-equivalent weight average molecular weight of 1,000 to 100,000 measured by gel permeation chromatography, Methacrylic acid can also be used in combination.
As a dispersion medium in the light adjustment suspension used in the above combination, it plays the role of a dispersion medium in the light adjustment suspension, and selectively adheres to and coats the light adjustment particles. It is preferable to use a liquid copolymer that acts to move the light control particles to the phase-separated droplet phase during phase separation, has no electrical conductivity, and has no affinity for the polymer medium.

  For example, a (meth) acrylic acid ester oligomer having a fluoro group and / or a hydroxyl group is preferred, and a (meth) acrylic acid ester oligomer having a fluoro group and a hydroxyl group is more preferred. When such a copolymer is used, one monomer unit of either a fluoro group or a hydroxyl group is directed to the light control particles, and the remaining monomer units are stably maintained as droplets of the light control suspension in the polymer medium. Therefore, the light control particles are very uniformly dispersed in the light control suspension, and the light control particles are guided into the phase-separated droplets during the phase separation.

  Examples of the acrylic ester oligomer having a fluoro group and / or a hydroxyl group include 2,2,2-trifluoroethyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, acrylic acid 3,5, 5-trimethylhexyl / 2-hydroxypropyl acrylate / fumaric acid copolymer, butyl acrylate / 2-hydroxyethyl acrylate copolymer, 2,2,3,3-tetrafluoropropyl acrylate / butyl acrylate / 2-Hydroxyethyl acrylate copolymer, 1H, 1H, 5H-octafluoropentyl acrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate / Butyl acrylate / 2-hydroxyethyl acrylate Polymer, 2,2,2-trifluoroethyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 2,2,3,3-tetrafluoropropyl methacrylate / butyl acrylate / acrylic acid 2- Hydroxyethyl copolymer, 1H, 1H, 5H-octafluoropentyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer, 1H, 1H, 2H, 2H-heptadecafluorodecyl methacrylate / butyl acrylate / 2-hydroxyethyl acrylate copolymer. It is more preferable to have both a fluoro group and a hydroxyl group.

  These acrylate oligomers preferably have a standard polystyrene equivalent weight average molecular weight measured by gel permeation chromatography of 1,000 to 20,000, more preferably 2,000 to 10,000. .

  It is preferable that the usage-amount of the fluoro group containing monomer used as the raw material of these acrylic acid ester oligomers is 6-12 mol% with respect to the monomer total amount which is a raw material, and it is 7-8 mol% more effectively. When the amount of the fluoro group-containing monomer used exceeds 12 mol%, the refractive index tends to increase and the light transmittance tends to decrease. Moreover, it is preferable that the usage-amount of the hydroxyl-containing monomer used as the raw material of these acrylic acid ester oligomers is 0.5-22.0 mol%, and is 1-8 mol% more effectively. When the usage-amount of a hydroxyl-containing monomer exceeds 22.0 mol%, there exists a tendency for a refractive index to become large and for light transmittance to fall.

The light adjusting suspension used in the present invention is one in which light adjusting particles are dispersed in a dispersion medium so as to be flowable. As the light control particles, for example, there is no affinity for the polymer medium or the resin component in the polymer medium, that is, the above-described silicone resin having a substituent having an ethylenically unsaturated bond, and the light control particles have a dispersibility. Pyrazine-2,3-dicarboxylic acid dihydrate, pyrazine-2,5-dicarboxylic acid-2, which is a precursor (substrate-forming substance) of light control particles, in the presence of a polymer dispersant that can be enhanced A polyiodide needle-like crystal produced by reacting one substance selected from the group consisting of hydrate and pyridine-2,5-dicarboxylic acid monohydrate with iodine and iodide is used. Examples of the polymer dispersant that can be used include nitrocellulose. Examples of iodide include calcium iodide. Examples of the polyiodide thus obtained include, for example, the following general formula CaI ₂ (C ₆ H ₄ N ₂ O ₄ ) · XH ₂ O (X: 1 to 2).
CaI _a (C ₆ H ₄ N ₂ O ₄ ) b · cH ₂ O (a: 3 to 7, b: 1 to 2, c: 1 to 3)
The thing represented by is mentioned. These polyiodides are preferably acicular crystals.

  In addition to the light control particles described above, for example, inorganic fibers such as carbon fibers, phthalocyanine compounds such as τ-type metal-free phthalocyanine, metal phthalocyanine, and the like can also be used. In the phthalocyanine compound, examples of the central metal include copper, nickel, iron, cobalt, chromium, titanium, beryllium, molybdenum, tungsten, aluminum, and chromium.

  In the present invention, the size of the light adjusting particles is preferably 1 μm or less, more preferably 0.1 to 1 μm, and further preferably 0.1 to 0.5 μm. When the size of the light adjusting particles exceeds 1 μm, there is a problem that the transparency is lowered, such as light scattering, or the orientation movement in the light adjusting suspension is lowered when an electric field is applied. There is also a case. The size of the light adjusting particles is a value of a 50% volume average particle diameter measured by a photon correlation spectroscopy measured with a submicron analyzer (for example, N4MD (manufactured by Beckman Coulter)).

  The light control suspension used in the present invention preferably comprises 1 to 70% by weight of light control particles and 30 to 99% by weight of dispersion medium, 4 to 50% by weight of light control particles and 50 to 96% of dispersion medium. % Is more preferable. The difference in refractive index between the polymer medium and the dispersant in the present invention is preferably 0.002 or less, more preferably 0.001 or less, and still more preferably 0.0005 or less. The light control material of this invention contains 1-100 weight part of light adjustment suspension normally with respect to 100 weight part of polymer media, Preferably it is 6-70 weight part, More preferably, it contains 6-60 weight part.

  After applying the above light-modulating material to one transparent conductive resin substrate with a certain thickness, the other transparent conductive resin substrate is overlaid and then irradiated with ultraviolet rays to cure the polymer medium. . A light control layer may be formed on both of the two transparent conductive resin substrates, and the light control layers may be laminated so that the light control layers are in close contact with each other. You may apply | coat a light control material, after providing a primer layer on the transparent conductive resin base material. The thickness of the light control layer is preferably 5 μm to 1,000 μm, and more preferably 45 μm to 150 μm.

  The droplet size (average droplet diameter) of the light control suspension dispersed in the resin matrix is usually 0.5 μm to 100 μm, preferably 0.5 μm to 20 μm, more preferably 1 μm to 5 μm. . The size of the droplets depends on the concentration of each component constituting the light control suspension, the viscosity of the light control suspension and the polymer medium, and the compatibility of the dispersion medium in the light control suspension with the polymer medium. Etc. can be adjusted.

  The average droplet diameter is calculated, for example, by taking an image such as a photograph from one surface direction of the light control film using SEM, measuring a plurality of arbitrarily selected droplet diameters, and calculating the average value thereof. Can do. It is also possible to capture a visual field image of the light control film with an optical microscope into a computer as digital data and calculate it using image processing integration software.

  For application of the light control material to be the light control layer, for example, known coating means such as a bar coater, applicator, doctor blade, roll coater, die coater, and comma coater can be used. In addition, when apply | coating, you may dilute a light control material with a suitable solvent as needed. When a solvent is used, it is preferable to dry the light-modulating material after it is applied on the transparent conductive resin substrate.

  Tetrahydrofuran, toluene, heptane, cyclohexane, ethyl acetate, ethanol, methanol, isoamyl acetate, hexyl acetate, etc. can be used as a solvent used for application of the light modulating material. In order to form a light control layer in which a liquid light control suspension is dispersed in the form of fine droplets in a solid resin matrix, the light control material is mixed with a homogenizer, an ultrasonic homogenizer, or the like. A method of finely dispersing a light control suspension in a molecular medium, a phase separation method by polymerization of resin components in a polymer medium, a phase separation method by solvent volatilization, or a phase separation method by temperature can be used. .

  According to said method, the light control film which can adjust light transmittance arbitrarily by formation of an electric field is provided. Even when no electric field is formed, the light control film maintains a clear coloring state without light scattering, and is converted into a transparent state when the electric field is formed. This ability exhibits a reversible repeat characteristic of over 200,000 times. In order to improve the light transmittance in the transparent state and the sharpness in the colored state, it is preferable to match the refractive index of the liquid light adjusting suspension with the refractive index of the resin matrix.

  The power source used for operating the light control film is alternating current, and can be in a frequency range of 10 V to 200 V (effective value) and 30 Hz to 500 Hz.

  When an electric field is not applied to the light control film, the light control particles in the light control suspension exhibit a brown motion, and thus show a clear coloring state due to light absorption of the light control particles and a dichroic effect. However, when an electric field is applied, the light adjusting particles in the droplet or the droplet connected body are arranged in parallel to the electric field and converted into a transparent state. Further, since the light control film is in the state of a film, there is a problem with the light control glass according to the prior art that uses the liquid light control suspension as it is, that is, the liquid between two transparent conductive resin substrates. Difficulty in injecting the suspension of the product, expansion phenomenon in the lower part due to the water pressure difference between the upper and lower parts of the product, local hue change due to changes in the base interval due to external environment such as wind pressure, between the transparent conductive resin base The leakage of the light control material due to the destruction of the sealing material is solved.

<Transparent conductive resin substrate>
As a transparent conductive resin substrate used for the light control film, for example, a transparent conductive layer (ITO, SnO ₂ , In ₂ O ₃ or the like) having a light transmittance of 80% or more is coated on the transparent resin substrate. A transparent conductive resin substrate having a surface resistance value of 3Ω / □ to 10 KΩ / □ can be used. The surface resistance can be measured according to JIS K 7194. On the other hand, the light transmittance can be measured according to the measurement method of the total light transmittance of JIS K7105.

  As the transparent resin substrate, for example, a polymer film or the like can be used. Examples of the polymer film include polyester films such as polyethylene terephthalate, polyolefin films such as polypropylene, polyvinyl chloride, acrylic resin films, polyethersulfone films, polyarylate films, and polycarbonate films. Can be mentioned. Among these, a polyethylene terephthalate film is preferable because it is excellent in transparency and excellent in moldability, adhesiveness, workability, and the like.

  The thickness of the conductive layer coated on the transparent resin substrate is preferably 10 nm to 5,000 nm. Although there is no restriction | limiting in particular in the thickness of a transparent resin base material, For example, in the case of a polymer film, 10 micrometers-200 micrometers are preferable. When the distance between the two transparent resin base materials is narrow, by using a transparent resin conductive base material in which a transparent insulating layer having a thickness of about several nm to 1 μm is formed on the conductive layer, a different substance can be obtained. It is possible to prevent a short circuit that occurs due to contamination of the material. Further, when the light control film is used for a reflection type light control window (for example, a rear view mirror for an automobile), a conductive metal thin film such as aluminum, gold, or silver as a reflector is used as a drive electrode. It may be used directly.

<Primer layer>
By forming a primer layer on the transparent conductive resin substrate constituting the light control film, the adhesion with the light control layer can be improved.
The material of the primer layer is not particularly limited, but a silicone resin, a material containing urethane acrylate containing a pentaerythritol skeleton, a material containing (meth) acrylate having a hydroxyl group in the molecule, and metal oxide fine particles as an organic binder resin The thin film is preferably formed of a dispersed material, a phosphate ester having one or more polymerizable groups in the molecule, a silane coupling agent having an amino group, and the like. Among these, a UV curable silicone resin is preferable from the viewpoint of forming a high hardness film.

  The primer layer can be formed, for example, by applying a material for forming the primer layer to the transparent conductive resin substrate. When applying, the material may be diluted with a suitable solvent. The thickness of the primer layer is preferably 40 nm to 100 nm from the viewpoint of adhesion, coloring, and haze increase. Moreover, you may perform a hardening process as needed after application | coating.

<Conductive film>
The conductive film used for joining the driving electrode of the light control film is not particularly limited as long as it is a film-like material having conductivity capable of thermocompression bonding the transparent conductive resin base material and the conductive thin film material. For example, a thermosetting resin in which conductive particles are dispersed can be molded into a tape shape.
Examples of the thermosetting resin that can be used for the conductive film include an epoxy resin and an acrylic resin, and among them, a thermosetting resin mainly composed of an acrylic resin is preferable from the viewpoint of low temperature and short time curing.

Examples of the conductive particles include metal coated particles such as resin particles subjected to nickel plating and gold plating, nickel particles subjected to gold plating, and copper particles subjected to silver plating, nickel particles, silver particles, and the like. Metal particles can be used.
The particle diameter of the conductive particles is preferably 0.01 to 50 μm from the viewpoint of preventing aggregation of the conductive particles, and more preferably 0.1 to 5 μm.
From the viewpoint of uniform dispersion of the conductive particles, the content of the conductive particles in the conductive film is preferably 0.01 to 20%, and more preferably 0.1 to 10%.

The thickness of the conductive film is preferably 0.1 μm to 100 μm from the viewpoint of conductivity, and more preferably 1 μm to 50 μm.
As an example of a conductive film, it is preferable to consist of an adhesive composition containing, for example, an adhesive component and conductive particles. As the adhesive component, for example, a material showing curability by heat or light can be widely applied. The use of a crosslinkable material is preferred because of excellent heat resistance and moisture resistance after connection. An epoxy adhesive containing an epoxy resin, which is a thermosetting resin, as a main component is preferable because it can be cured for a short time, has good connection workability, and has excellent adhesion in terms of molecular structure. A radical curing adhesive composition as described in International Publication No. 2009/063827 can also be used. Epoxy adhesives are, for example, high molecular weight epoxy, solid epoxy or liquid epoxy, or those mainly composed of epoxy modified with urethane, polyester, acrylic rubber, nitrile rubber (NBR), synthetic linear polyamide or the like. Can be used. The epoxy adhesive is generally obtained by adding a curing agent, a catalyst, a coupling agent, a filler, or the like to the above-mentioned epoxy which is a main component.

  Examples of the conductive particles include particles of metals such as Au, Ag, Pt, Ni, Cu, W, Sb, Sn, solder, and carbon. Further, coated particles in which non-conductive glass, ceramic, plastic, or the like is used as a core and the core is coated with the above metal or carbon may be used. The average particle diameter of the conductive particles is preferably 1 μm to 18 μm from the viewpoint of dispersibility and conductivity. Insulating coating particles obtained by coating conductive particles with an insulating layer may be used, and conductive particles and insulating particles may be used in combination from the viewpoint of improving the insulation between adjacent electrodes.

  The content ratio of the conductive particles is preferably 0.1 to 30 parts by volume, and more preferably 0.1 to 10 parts by volume with respect to 100 parts by volume of the adhesive component contained in the conductive film. If this content is less than 0.1 part by volume, the connection resistance between the opposing electrodes tends to increase, and if it exceeds 30 parts by volume, a short circuit between adjacent electrodes tends to occur. In addition, about the component contained in these electrically conductive films, its content, a compounding method, etc., the component, its content, the compounding method, etc. which are described in international publication 2009/063827 can be used.

<Conductive material>
The conductive material used for producing the drive electrode for the light control film is not particularly limited as long as it is a material that can connect the light control film and an external drive power source. Examples thereof include a conductive tape having a surface resistance value of 1 mΩ / □ to 100 mΩ / □ to which a conductive adhesive material is applied, a flexible printed circuit board, and the above transparent conductive resin base material.
Examples of the metal foil include copper foil, aluminum foil, lead foil, etc. However, soldering is necessary when wiring from a conductive thin film material when connecting to the drive power source of the light control film. A copper foil that is easy to attach is preferable.

As the conductive adhesive material, an acrylic adhesive material containing any of metal fine particles such as nickel, silver and copper, fibers or fine particles made of carbon, and conductive particles obtained by coating metal with resin fine particles is preferable.
Examples of the flexible printed circuit board include PI (polyimide) and PEN (polyethylene naphthalate).
As a transparent conductive resin base material, the transparent conductive resin base material which forms an above-described light control film can be mentioned.

The conductive material is preferably in the form of a thin film. Although there is no restriction | limiting in particular in thickness, The range which does not exceed the thickness of the transparent conductive resin base material used for a light control film is preferable, 10 micrometers-200 micrometers are more preferable, It is more preferable that it is 50-100 micrometers.
The resistivity of the conductive material preferably from the viewpoint of keeping small contact resistance between 1~100mΩ / cm ² and it is transparent electroconductive resin substrates, and more preferably 0.1~1Ω / cm ^2.

<Manufacturing method of light control film with conductive material>
The light control film with a conductive material of the present invention is sandwiched between two transparent conductive resin substrates having conductive surfaces and the two transparent conductive resin substrates, and dispersed in the resin matrix and the resin matrix. By the method including the step of thermocompression bonding a conductive material through the conductive film to the conductive surface of the transparent conductive resin substrate of the light control film having a light control layer containing the light control suspension Manufactured.

Specifically, for example, it is formed through the following steps.
(1) Desirable part corresponding to a part (drive electrode part) for forming a drive electrode of one of the two transparent conductive resin bases facing the other transparent conductive resin base Cut and remove the electrode shape.
(2) The light control layer exposed after the removal of the transparent conductive resin substrate is removed by scraping or the like. (3) The primer layer 3 (driving electrode portion) exposed by removing the light control layer is wiped and washed with a solvent such as hexane.
It is preferable from the viewpoint of adhesion to perform UV ozone cleaning after solvent cleaning. The UV ozone cleaning method is not particularly limited, and examples thereof include a low pressure mercury lamp and an excimer lamp.

(4) A conductive film and a conductive material such as a conductive tape are sequentially attached to the drive electrode portion. Prior to attaching the conductive material, the conductive film may be thermocompression bonded to the driving electrode portion. In this case, the thermocompression bonding condition is preferably 60 to 200 ° C. from the viewpoint of dimensional change during heating of the driving electrode portion, and more preferably 70 to 90 ° C. The time is preferably 1 to 10 seconds from the viewpoint of distortion and warpage due to heat of the drive electrode portion, and more preferably 1 to 3 seconds. The pressure is preferably 0.5 to 3 MPa from the viewpoint of adhesion, and more preferably 1 to 2 MPa. Or you may affix the conductive film side of the laminated body which bonded the conductive film and the electrically conductive material beforehand to the electrode part for a drive.

(5) The thermocompression bonding head heated from above the conductive material is pressed to thermally bond the conductive film and the conductive material to the driving electrode portion.
The temperature of thermocompression bonding is preferably 160 to 190 ° C. from the viewpoint of distortion and warpage due to heat of the driving electrode portion, and more preferably 70 to 100 ° C.
The time for thermocompression bonding is preferably 5 to 60 seconds from the viewpoint of preventing cracks due to thermal stress in the driving electrode portion, and more preferably 10 to 20 seconds.
The pressure for thermocompression bonding is preferably 1 to 5 MPa from the viewpoint of adhesion with the driving electrode portion, and more preferably 2 to 3 MPa.
The method of thermocompression bonding is not particularly limited as long as heat and pressure can be applied to the conductive material and the conductive film, and examples thereof include a method of pressing a thermocompression bonding head against the conductive material and the conductive material.
These series of steps are performed on both of the two transparent conductive resin substrates facing each other.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Production example of light control particles)
In order to produce light-controlling particles, a 500 ml four-necked flask equipped with a stirrer and a condenser tube was charged with 15% by mass of nitrocellulose 1 / 4LIG (trade name, manufactured by Bergerac NC) isoamyl acetate (special reagent grade, Wako Pure Chemical Industries, Ltd.) diluted solution 87.54 g, isoamyl acetate 44.96 g, dehydrated CaI ₂ (chemical, Wako Pure Chemical Industries, Ltd.) 4.5 g, absolute ethanol (for organic synthesis, Wako Pure) Yield (JIS reagent special grade, Wako Pure Chemical Industries, Ltd.) 4.5g was dissolved in a solution of 2.0g of Yakuhin Co., Ltd. and 0.6g of purified water (manufactured by Wako Pure Chemical Industries, Ltd.). Then, 3 g of pyrazine-2,5-dicarboxylic acid dihydrate (manufactured by PolyCarbon Industries), which is a base forming substance of the light control particles, was added. After stirring at 45 ° C. for 3 hours to complete the reaction, the mixture was dispersed with an ultrasonic disperser for 2 hours. At this time, the hue of the mixed solution changed from brown to dark blue.

  Next, in order to take out light control particles having a constant size from the reaction solution, the light control particles were separated using a centrifuge. The reaction solution was centrifuged at a speed of 750 G for 10 minutes to remove precipitates, and further centrifuged at 7390 G for 2 hours to remove suspended matters, and precipitate particles were collected. The precipitate particles were needle-like crystals having an average particle diameter of 0.36 μm as measured with a submicron particle analyzer (product name: N4MD, manufactured by Beckman Coulter, Inc.). The precipitate particles were used as light control particles.

(Production example of light control suspension)
45.5 g of the light control particles obtained in the above (Example of manufacturing light control particles) were used as a dispersion medium for the light control suspension butyl acrylate (Wako Special Grade, manufactured by Wako Pure Chemical Industries, Ltd.) / Methacrylic acid. 2,2,2-trifluoroethyl (for industrial use, manufactured by Kyoeisha Chemical Industry Co., Ltd.) / 2-hydroxyethyl acrylate (Wako Grade 1, manufactured by Wako Pure Chemical Industries, Ltd.) copolymer (monomer molar ratio: 18 /1.5/0.5, weight average molecular weight: 2,000, refractive index 1.4719) In addition to 50 g, the mixture was mixed with a stirrer for 30 minutes. Subsequently, isoamyl acetate was removed under reduced pressure at 80 ° C. for 3 hours at a vacuum of 133 Pa using a rotary evaporator to produce a stable liquid light-conditioning suspension free from precipitation and aggregation of light-conditioning particles.

(Example of production of energy ray curable silicone resin)
In a four-necked flask equipped with a Dean-Stark trap, condenser, stirrer, and heating device, 17.8 g of both-end silanol polydimethylsiloxane (reagent, manufactured by Chisso Corporation), both-end silanol polydimethyldiphenylsiloxane (reagent, 62.2 g of Chisso Corp.), 20 g of (3-acryloxypropyl) methyldimethoxysilane (reagent, Chisso Corp.), 0.1 g of 2-ethylhexane tin (Wako Pure Chemical Industries Ltd.) The reaction was carried out by refluxing in heptane at 100 ° C. for 3 hours.

  Next, 25 g of trimethylethoxysilane (reagent, manufactured by Chisso Corporation) was added, refluxed for 2 hours, dealcoholized, and heptane was removed under reduced pressure at 80 ° C. for 4 hours at 100 Pa using a rotary evaporator. An energy ray curable silicone resin having a weight average molecular weight of 35000 and a refractive index of 1.4745 was obtained. The obtained energy ray curable silicone resin was used as a polymer medium. From the hydrogen integration ratio of NMR, the ethylenically unsaturated bond concentration of this resin was 0.31 mol / kg. The ethylenically unsaturated bond concentration was measured by the following method.

[Measurement method of ethylenically unsaturated bond concentration]
The ethylenically unsaturated bond concentration (mol / kg) was calculated from the hydrogen integral ratio of NMR (integral value of hydrogen of ethylenically unsaturated bond near 6 ppm, integral value of phenyl group hydrogen near 7.5 ppm, and Use the integral value around 0.1 ppm of hydrogen of the methyl group). Measurement solvent was CDCl _3. In the resin produced above, the mass ratio calculated from the hydrogen integral ratio of NMR is methyl group: phenyl group: ethylenically unsaturated bond group = 11: 6.4: 1, ethylenically unsaturated bond group in the whole. The number of ethylenically unsaturated bonding groups per molecule was 9.35 from the molecular weight of each, and the number of moles per kg was calculated to be 0.31 mol / kg.

(Manufacturing example of light control material)
10 g of energy ray curable silicone resin obtained in the above (Production example of energy ray curable silicone resin), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Ciba Specialty) as a photopolymerization initiator・ To 0.2 g of Chemicals Co., Ltd.) and 0.3 g of dibutyltin dilaurate as a coloring inhibitor, 2.5 g of the light control suspension obtained in the above (Production Example of Light Control Suspension) was added, Using a Polytron homogenizer Model K (manufactured by KINEMATICA), the mixture was mechanically mixed for 1 minute to produce a light-modulating material.

(Production example of transparent conductive resin substrate with primer layer)
Transparent conductive film comprising a PET film (300R, manufactured by Toyobo Co., Ltd., thickness 125 μm) having a surface electrical resistance value of 200 to 400Ω / □ coated with an ITO (indium tin oxide) transparent conductive film (thickness 3000 nm). UV curable silicone resin coating agent (trade name: AY42-151, manufactured by Toray Dow Corning Co., Ltd.) on isopropyl resin: 1-methoxy-2-propanol = 1: 1 A solution dissolved in a mixed solvent so as to be 1.0% by mass was applied on the entire surface using a micro gravure method (mesh # 150). After drying at 50 ° C./30 s, 60 ° C./30 s, and 70 ° C./1 min, UV curing was performed with 1,000 mJ / cm 2 (metal halide lamp) to form a primer layer. AY42-151 contains a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone). The thickness of the primer layer measured using an instantaneous spectrophotometer F-20 (manufactured by Filmetrics Co., Ltd.) was 73 nm.

(Manufacturing example of light control film)
Apply the light control material obtained in the above (Manufacturing Example of Light Control Material) to the entire surface of the primer layer of the transparent conductive resin substrate with the primer layer by a coating method using a die coater, and then attach the other primer layer. The transparent conductive resin base material was laminated and adhered so that the primer layer faced the surface to which the light control material was applied. Using a metal halide lamp, ultraviolet rays of 3,000 mJ / cm ² were irradiated from the PET film sides on both sides of the laminated transparent conductive resin substrate. As a result, a structure in which a film-shaped light control layer having a thickness of 90 μm formed in a state where the light control suspension is dispersed as a spherical droplet in a UV-cured resin matrix is sandwiched between transparent conductive resin bases is formed. A light control film having a thickness of 340 μm was produced.

Example 1
The light control film with a conductive material of Example 1 was produced according to an example of the production method of the present invention. Hereafter, each process is demonstrated, referring FIG. Since the conductive material needs to be bonded to each of the two transparent conductive resin base materials, each step is performed on each of the two transparent conductive resin base materials.

(1) The light control film obtained in the above (Manufacturing Example of Light Control Film) is cut into 50 mm × 100 mm, and the transparent conductive resin base material 4 in a range of 50 mm × 5 mm is cut off at both ends of the side having a length of 50 mm. The light control layer was exposed. Next, the exposed light control layer was scraped off with a plastic spatula. Furthermore, the primer layer 3 in the scraped portion was solvent-washed with a nonwoven fabric impregnated with hexane to obtain a driving electrode portion (FIG. 2A). Thereafter, the driving electrode part was UV cleaned for 90 seconds with a UV ozone cleaning device (manufactured by Oak Manufacturing Co., Ltd., UV dry processor).
(2) Conductive film 5 (with separator 7) cut to a width of 50 mm × 1.5 mm (MF-311, manufactured by Hitachi Chemical Co., Ltd.) was attached to the drive electrode portion (FIG. 2B). .

(3) A thermocompression bonding head was pressed from above the separator 7 of the conductive film 5 to perform thermocompression bonding (FIG. 2C). At this time, the temperature of the thermocompression bonding head was 140 ° C. (the temperature of the conductive film 5 was 80 ° C.), the pressure during thermocompression bonding was 1 MPa, and the pressure bonding time was 1 second.
(4) The separator 7 of the conductive film 5 was peeled and removed, and the conductive material 6 (Sony Chemical & Information Device copper tape, CU7636) was attached to the exposed surface of the conductive film 5 (FIG. 2D).
(5) The thermocompression bonding head 8 was pressed from above the conductive material 6 to perform thermocompression bonding (FIG. 2E). At this time, the temperature of the thermocompression bonding head 8 was 150 ° C., the pressure during thermocompression bonding was 2 MPa, and the pressure bonding time was 20 seconds.
The above process was performed with respect to the two transparent conductive resin base materials 4, and the light control film with a conductive material was obtained (FIG.2 (F)).

(Example 2)
The light control film with a conductive material of Example 2 was manufactured according to another example of the manufacturing method of the present invention. Hereafter, each process is demonstrated, referring FIG. Since the conductive material needs to be bonded to each of the two transparent conductive resin base materials, each step is performed on each of the two transparent conductive resin base materials.

(1) The light control film obtained in the above (Manufacturing Example of Light Control Film) is cut into 50 mm × 100 mm, and the transparent conductive resin base material 4 in a range of 50 mm × 5 mm is cut off at both ends of the side having a length of 50 mm. The light control layer was exposed. Next, the exposed light control layer was scraped off with a plastic spatula. Furthermore, the primer layer 3 in the scraped portion was solvent-washed with a nonwoven fabric impregnated with hexane to obtain a driving electrode portion (FIG. 3A). Thereafter, the driving electrode part was UV cleaned for 90 seconds with a UV ozone cleaning device (manufactured by Oak Manufacturing Co., Ltd., UV dry processor).

(2) Conductive film 5 and conductive material 6 (Sony Chemical & Information Device copper tape, CU7636) laminated in advance and cut into a width of 50 mm × 1.5 mm, and the laminated conductive film 5 side was affixed on the drive electrode surface (FIG. 3B).
(3) A thermocompression bonding head was pressed from above the conductive material 6 to perform thermocompression bonding (FIG. 3C). At this time, the temperature of the thermocompression bonding head 8 was 150 ° C., the pressure during thermocompression bonding was 2 MPa, and the pressure bonding time was 20 seconds.
The above process was performed with respect to the two transparent conductive resin base materials 4, and the light control film with a conductive material was obtained (FIG.3 (D)).

(Example 3)
A light control film with a conductive material was produced by changing the pressure during thermocompression bonding of Example 2 (3) to 3 MPa.

(Comparative Example 1)
As Comparative Example 1, only the solvent cleaning with hexane was performed on the driving electrode portion of the transparent conductive resin substrate 4 exposed in the same manner as in Examples 1 to 3. Then, the light control film was produced by affixing the electrically conductive material 6 (Sony Chemical & Information Device copper tape, CU7636) on the drive electrode part without passing through the conductive film. This structure is a simple conventional structure example.

(Comparative Example 2)
As Comparative Example 2, solvent driving with hexane was performed on the driving electrode portion of the transparent conductive resin base material 4 exposed in the same manner as in Examples 1 to 3, and then UV ozone cleaning was performed for 90 seconds. After that, a conductive paste (manufactured by Taiyo Ink Manufacturing Co., Ltd., ECM-100 AF4810) was applied to the driving electrode part with a rubber squeegee to a thickness of 100 μm within a range of 50 mm × 5 mm, and the temperature was adjusted to 90 ° C. with a dryer 30 It hardened for minutes and formed the conductive paste base. Conductive material 6 (Sony Chemical & Information Device copper tape, CU7636) was affixed on the obtained conductive paste base to produce a light control film. This structure is an example of a structure with excellent adhesion.

  In the above Examples and Comparative Examples, the time required to join the conductive material 6 to the drive electrode portion of one (one side) transparent conductive resin base material 4 is about 4 minutes in Examples 1 and 2. In Example 3, it was about 2 minutes 30 seconds. These values are close to about 2 minutes of Comparative Example 1 and are greatly shortened from 45 minutes of Comparative Example 2 which has excellent adhesion.

(Heat aging test)
A heat aging test was performed on the samples prepared in Examples 1 to 3 and Comparative Examples 1 and 2. Specifically, the change over time in the transmittance retention rate during energization was measured under heating conditions of 100 ° C. That is, a heat aging test was performed by charging and heating a sample in a constant temperature and temperature controlled air oven (DKM600, manufactured by Yamato Kagaku Co., Ltd.) whose temperature was adjusted to 100 ° C. A sample was taken out every predetermined time, and transmittance retention was measured. The test was conducted with about 1000 hours as a guide.

The transmittance retention of the light control film with a conductive material when energized was measured as follows. That is, a sample driving electrode (conductive material) is connected to an AC power source (PCR500M, manufactured by Kikusui Electronics Co., Ltd.), and a 100 V / 50 Hz signal is applied to drive a light control film while a haze meter (Tokyo Denshoku, TC -1800H) was used to measure the total line transmittance. This total line transmittance was defined as the transmittance. The initial transmittance was set to 100%, and the transmittance retention for each time the sample was taken out was observed according to the following formula.
Transmittance retention ratio during energization (%) = transmittance at the time when a sample is taken out / initial transmittance × 100

  As a result, as shown in FIG. 4, there was no significant difference in heat aging characteristics between the light control films with conductive material of Examples 1 to 3 of the present invention and the light control films with conductive material of Comparative Examples 1 and 2. . Moreover, although a part of the electrode of Comparative Example 1 was peeled off, the electrodes of Examples 1 to 3 and Comparative Example 2 were not peeled off.

(Thermal shock test)
In order to evaluate the adhesion strength of the drive electrode structure of the light control film with conductive material prepared in Examples 1 to 3 and Comparative Examples 1 and 2, a thermal shock test was performed as follows.
The transparent conductive resin base material 4 before producing the light control film is cut into 50 mm × 100 mm, and the same production procedure as in Examples 1 to 3 and Comparative Examples 1 and 2 is performed on both sides of the length of 50 mm. Driving electrodes (conductive film and conductive material, only conductive material, or conductive paste base and conductive material) were formed (FIG. 5). Thereafter, the sample was put into a small thermal shock device (manufactured by ESPEC, TSE-11-A), and a thermal shock test was performed in a cycle of −20 ° C./20 minutes holding and 80 ° C./20 minutes holding. The number of cycle tests was 240 cycles.

  Before and after the test, the interelectrode resistance of the sample was measured using a digital multimeter (manufactured by Sanwa Denki Keiki Co., Ltd., RD701). As a result, as shown in Table 1, in Comparative Example 1, an increase in resistance was observed. This is due to peeling of the conductive tape. On the other hand, in the electrode structures of Examples 1 to 3, the interelectrode resistance did not increase rapidly even after the thermal shock test, and good adhesion was obtained.

DESCRIPTION OF SYMBOLS 1 Resin matrix 2 Droplet 3 Primer layer 4 Transparent conductive resin base material 4a Transparent conductive film 4b Transparent resin base material 5 Conductive film 6 Conductive material 7 Conductive film separator 8 Thermocompression head 9 Receiving base 10 Driving electrode

Claims (6)

Two transparent conductive resin substrates having a conductive surface;
A light control layer that is sandwiched between the two transparent conductive resin substrates and includes a resin matrix and a light control suspension dispersed in the resin matrix;
A conductive material bonded to the conductive surface via a conductive film;
A light control film with a conductive material.   The conductive material according to claim 1, wherein the conductive material is at least one selected from the group consisting of a metal foil, a conductive tape, a flexible printed circuit board, and a transparent conductive resin base material having a conductive surface. Light control film.   The light control film with a conductive material according to claim 1 or 2, wherein the conductive film contains a thermosetting resin and conductive particles.   A dimming layer comprising two transparent conductive resin substrates having conductive surfaces, and a light adjustment suspension sandwiched between the two transparent conductive resin substrates and dispersed in the resin matrix 4. The method according to claim 1, comprising a step of thermocompression bonding a conductive material to the conductive surface of the transparent conductive resin substrate of the light control film having a conductive film via the conductive film. The manufacturing method of the light control film with a conductive material of description.   The step of thermocompression bonding includes the step of thermocompression bonding the conductive film to the conductive surface of the transparent conductive resin base material, and the thermocompression bonding of the conductive material to the conductive film on the transparent conductive resin base material. The manufacturing method of the light control film with an electrically conductive material of Claim 4 including a process.   The step of thermocompression bonding includes a surface having conductivity of the transparent conductive resin base material and a laminate of the conductive film and the conductive material, and the conductive film side of the laminate is the transparent conductive resin base material. The manufacturing method of the light control film with a conductive material of Claim 4 including the process of thermocompression-bonding so that the surface which has the electroconductivity may be touched.