JP2019191481A - Dimming body - Google Patents

Abstract

To provide a dimming body comprising a dimming film laminated and fixed on a transparent substrate, the dimming film having a peripheral edge sealing part that solves problems of fracture, deformation or peeling due to modification in a sealing part accompanying changes with time or changes in a use environment.SOLUTION: The dimming body has a dimming film laminated and fixed on a glass substrate, where the dimming film has a dimming layer held between first and second laminates each having a transparent electrode layer on a resin film and modulates a transmission state of light by electrically controlling the dimming layer. In the dimming body, the dimming film has a sealing part in a peripheral edge of the dimming film, the sealing part covering a side end face where the laminate structure is exposed; and The sealing part comprises a sealing material applied to cover the side end face, and has a portion (a) from a side face end where the laminate structure of the dimming film is exposed to above the resin film and a portion (b) extending from the end to a peripheral direction outside the resin film, in which the (a) portion and the (b) portion are 1 mm or more and 10 mm or less and the (b) portion is 1 or more and 5 or less times as the (a) portion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light control body using a light control film including an optical element that modulates a light transmission state by electrical control.

  As the type of the optical element, a liquid crystal element, an electrochromic material, a suspended particle device (SPD: Suspended Particle Device), or the like can be appropriately selected according to the requirement of the visual effect exhibited by the light control film. Hereinafter, the liquid crystal element will be described as a representative.

  As a general display device, a liquid crystal display device is used in various fields such as an information display device such as numerical values and an image display device such as video.

  In a display device using a liquid crystal material, liquid crystal molecules are aligned and sandwiched between substrates having electrodes arranged at regular intervals, and these are sandwiched between two polarizing plates. The liquid crystal is driven to change the transmittance of the deflected light, thereby enabling display by modulation of the light transmitting state and the light blocking state in units of cells (pixels).

  On the other hand, in areas such as windows in residential spaces such as architecture and automobiles, there is a study on light control glass that has a window glass with an optical function to keep the living space comfortable according to changes in the external environment. (For example, Non-Patent Document 1).

  In the case of using a liquid crystal material for such a light control glass, unlike the method for a display device described above, a polarizing plate is not used, and a liquid crystal display element having a high light utilization efficiency is used. There is a liquid crystal display element that switches between a (transparent state) and a scattering state (opaque state), and it is arranged in a void formed inside a polymer network made of resin formed in a three-dimensional network. Polymer network type liquid crystal (PNLC) with liquid crystal molecules or polymer dispersed liquid crystal (PDLC) with liquid crystal molecules dispersed and arranged in the polymer Is known, and is employed as an element that exhibits not only translucency and light shielding but also transparency and scattering.

  The liquid crystal layer is likely to be deteriorated by acid, moisture, ultraviolet rays, etc. In particular, the sheet edge (peripheral edge) where the liquid crystal layer is sandwiched is likely to come into contact with moisture, acid, ultraviolet rays, etc., and the liquid crystal layer is deteriorated. It is likely to occur.

  As a proposal relating to a peripheral structure sealing structure in a PDLC panel in which PDLC is coated on a front substrate and a rear substrate is laminated on the front substrate, in Patent Document 1, the front substrate surface, the rear substrate side surface, and the PDLC side surface are provided. A seal structure for applying a sealant is disclosed.

  In Patent Document 1, as a characteristic required for a sealant, it is a solvent-free silicone adhesive having a viscosity of 100,000 to 500,000 CP, and the sealant is made similar in color to the color of the PDLC panel. It is disclosed that the presence of

In another form of PDLC panel,
(1) The front substrate and the rear substrate are held through a spacer, and a sealing agent is applied to the opposing surfaces of several millimeters around both substrates by printing or the like to form a panel. Injected form (for example, see Patent Document 2)
(2) Both the front substrate and the back substrate are not rigid base materials (glass, resin plate), but use a flexible resin film, and are suitable for manufacturing in a roll-to-roll method. Proposals can be seen, but a peripheral seal structure is required by means of suitable characteristics and methods.

JP-A-6-186574 International Publication No. 2017/146039

NEW GLASS Vol. 13 No. 1 1998 P48-51 An optical element (liquid crystal material) is sandwiched between a flexible resin film substrate on which a transparent electrode (or further an alignment film) is formed. There is also a usage form in which it is bonded to a transparent substrate and put to practical use as a rigid dimmer as a whole. In this case, the optical element (liquid crystal layer) that tends to deteriorate is surely protected from contact with moisture, acid, ultraviolet rays, etc. at the film edge (peripheral edge), and the two resin film substrates are peeled off. While avoiding, it is necessary to prevent a light control film from peeling from a transparent substrate.

  When the light control body is used for a long period of time, there is a problem that the sealing material is gradually peeled off from the transparent substrate or the resin film base material and air enters, and the temperature change applied to the light control body increases. It shows a tendency that the stop part is easily peeled off. Therefore, establishment of a sealing technique that does not have poor adhesion over a long period of time is an important issue.

  In the form in which the light control film is laminated and fixed to the glass substrate, there are two types of delamination accompanying the breakdown in the sealing material due to external force due to a decrease in adhesion and strength due to the sealing material at the interface between the light control film and the glass substrate. Can be considered. Therefore, the sealing material is required to have mechanical strength in addition to adhesion.

  In the present invention, a light control film using a flexible resin film as a front substrate and a rear substrate is used over time or when it is used while being held and fixed on a rigid base material (transparent substrate) such as a glass substrate. An object of the present invention is to propose a light control body having a peripheral seal portion that is effective in solving the problems of breakage, deformation, and peeling due to the modification of the sealing portion due to environmental changes and improving the reliability.

The light control film according to the present invention comprises:
A light control layer is sandwiched between first and second laminates having at least a transparent electrode layer on a resin film, and the transmitted light is modulated by modulating the light control layer by electrical control to control transmitted light. In the light control body formed by laminating and fixing the optical film on the glass substrate,
In the peripheral part including the four corners of the rectangular light control film, it has a seal part that covers the side end face where the laminated structure is exposed,
The sealing part is formed by applying a sealing material so as to cover the side end surface,
The seal portion includes a portion (a) that extends on the resin film from the side end portion where the laminated structure of the light control film is exposed, and a portion (b) that extends from the end portion in the peripheral direction outside the resin film. The length of each part is such that (a) part and (b) part are 1 mm or more and 10 mm or less, and (b) part is 1 time or more and 5 times or less of (a) part. To do.

It is preferable that the thickness (c) of the sealing material in the lamination direction of the light control film is 1 to 2 times the thickness (f) of the light control film excluding the sealing portion.

  The strength required for peeling off the first and second laminates is preferably 4 N / 25 mm or more.

  According to the present invention, the sealing state of the seal portion of the light control film is preferably maintained, and the problems of breakage, deformation, and peeling due to the modification of the seal portion with the passage of time or use environment are solved, and the light control film There is provided a light adjuster including a peripheral seal portion that is effective in suitably maintaining the lamination and fixing to a transparent substrate.

Explanatory drawing which shows an example of the light control film which concerns on embodiment of this invention. Sectional drawing which shows the other examples of the light control film which concerns on embodiment of this invention. The top view which shows an example applied to the light control film light control apparatus which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted. Each drawing shows an example of an embodiment of the present invention and is not limited to these.

  Drawing 1 is a top view (A) and a sectional view (B) showing an example of a light control object concerning an embodiment of the present invention.

  The light control body 10 has a configuration in which a light control film 11 is laminated and fixed on a glass substrate 20 by a seal portion 12.

  As shown in FIG. 1B, the light control film 11 includes a light control layer (liquid crystal layer) 13 and a flexible transparent film 14 on which a transparent electrode 15 is formed so as to sandwich both surfaces thereof. In addition, a seal portion 12 is provided at the peripheral edge of the light control film 11, and the light control film 10 (entire) is configured.

  Any material can be used for the transparent film 14 as long as it is a substantially transparent flexible film substrate suitable for production in a roll-to-roll system. Specifically, for example, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate resins, acrylic resins, cellulose derivatives such as triacetylcellulose (TAC), and polyethersulfone (PES). A film made of a resin, a polyimide resin, a polyolefin-based resin such as polyethylene or polypropylene can be used, but is not necessarily limited thereto.

  Such a transparent film may be added with an ultraviolet absorber, a stabilizer, etc., and an ultraviolet absorbing layer, a heat ray reflective layer, a barrier layer, etc. are provided on either side of the transparent film. No problem.

Further, there is no problem even if the transparent film is appropriately subjected to easy adhesion treatment, antistatic treatment, and the like.

  Any material can be used for the transparent electrode 15 as long as it is a conventionally known electrode material having transparency, for example, an indium tin oxide (ITO) conductive film, a tin oxide conductive film, a zinc oxide conductive film, and a polymer conductive film. However, the present invention is not necessarily limited thereto. Such a transparent electrode 15 is formed by using a physical vapor deposition method (PVD method) such as a vacuum deposition method or a sputtering method, various chemical vapor deposition methods (CVD method), various coating methods, or the like. Can do.

  In addition, if the transparent electrode 15 needs to be patterned as desired, it can be performed by an arbitrary method such as an etching method, a lift-off method, a laser trimming method, or a method using various masks.

  An alignment film or the like may be appropriately provided on the transparent electrode 15 (on the light control layer 13 side) as necessary. The alignment film may be either a horizontal alignment film or a vertical alignment film as long as it is a conventionally known alignment film, and can be appropriately selected according to the application.

  In the present invention, any type of liquid crystal composition of PDLC and PNLC can be used as the light control layer 13.

  Two types of normal mode and reverse mode are known for the light control layer 13 made of a liquid crystal element, depending on its usage. The normal mode is a mode in which a transmission state is obtained by applying voltage (ON) and a scattering state is obtained by removing voltage (OFF). The reverse mode is a mode in which a transmission state is obtained by voltage removal (OFF) and a scattering state is obtained by voltage application (ON). In the reverse mode, a film substrate in which an alignment film is formed on the transparent electrode 15 is required.

  In the light control layer by PNLC, there is almost no unreacted component in the phase separation, and the polymer network and the liquid crystal region are clearly separated with high purity.

  In addition, an ideal alignment state can be realized without performing a pretilt alignment process by rubbing the substrate (conductive film), and the liquid crystal molecules are aligned almost uniformly in each domain divided by the polymer network. It will be.

  The driving voltage of PNLC generally depends on the structural characteristics of the polymer network (domain size and shape, film thickness of the polymer network, etc.). The structure of the polymer network and the obtained light transmittance or light scattering In this relationship, the drive voltage is determined. In order to construct a PNLC in which sufficient light transmission or scattering is obtained in a voltage region of 100 V or less, each domain should be uniform in size and uniform in size. It is necessary to form a polymer network.

  In the present invention, the domain size depending on the polymer network structure is controlled to be 3 μm or less, preferably 2 μm or less, and more preferably about 1 μm.

  As the polymer material, any conventionally known material can be used, but an ultraviolet curable resin that can be cured by inducing a polymerization reaction by ultraviolet irradiation is preferably used.

  Specific examples include various (meth) acrylate compounds such as urethane (meth) acrylate, epoxy (meth) acrylate, and isobonyl (meth) acrylate, but are not limited thereto.

  Such an ultraviolet curable resin may be added with a polymerization initiator, a sensitizer, various stabilizers, and the like.

  As the liquid crystal material, any conventionally known liquid crystal material such as nematic liquid crystal, smectic liquid crystal, and cholesteric liquid crystal can be used. Among these, in consideration of driving at low voltage and scattering characteristics, those having a high dielectric anisotropy and a large refractive index anisotropy are preferable.

  Such a liquid crystal material may have a functional group such as an ethylene group used for the polymerization reaction of the polymer material described above, or may be introduced in advance as a side chain into the polymer material before the polymerization reaction. May be.

  Spacers may be introduced into the light control layer 13 as described above. By introducing the spacer, the thickness of the light control layer 13 can be kept uniform.

  Although it does not specifically limit as a spacer, A granular resin spacer, a granular glass spacer, etc. can be used suitably.

  As a method for providing the light control layer 13, a liquid crystal composition is applied on the transparent film having the transparent electrode using various coaters and the like, and then the transparent film having the other transparent electrode is laminated. A conventionally known method such as a method or a so-called ODF (One-Drop-Fill) method in which a liquid crystal composition is dropped can be arbitrarily used.

  A seal portion 12 for protecting the light control layer 13 from moisture, acid, ultraviolet rays and the like is provided on the peripheral edge portion of the light control film 11 obtained as described above by coating.

  As a sealing material used for the seal portion 12, for example, in various resin systems such as an epoxy resin, a urethane resin, an acrylic resin, a vinyl acetate resin, an ene-thiol resin, a silicone resin, and a modified polymer, Various resin materials such as a thermosetting type, a photocuring type, a moisture curing type, and an anaerobic curing type can be used.

  Although it can be said that the seal portion 12 for obtaining such characteristics is substantially transparent, a pigment, a filler, or the like may be appropriately added depending on the situation. In the case of adding a dye, in consideration of weather resistance and the like, a pigment-based dye is desirable.

  As shown in FIGS. 1 (A) and 1 (B), the seal portion 12 includes a portion (a) that is applied on the resin film from the side end portion where the laminated structure of the light control film 11 is exposed, and the resin film outside from the end portion. Part (b) extending in the peripheral direction, and the length of each part is (a) part 10 mm or less, (b) part is 1 to 5 times the (a) part It is formed as follows. In FIG. 1, the portion (b) corresponds to the coating thickness of the sealing material (sealing material) that covers the side surface end where the laminated structure of the light control film 11 is exposed, and the width at which the sealing portion 12 is bonded to the glass substrate 20. It corresponds to.

  As shown in the cross-sectional view of FIG. 2, the seal portion 12 is made of glass rather than the coating thickness of the seal material (sealing material) that covers the side end portion where the laminated structure of the light control film 11 is exposed. A structure in which the portion (b) takes a large value as the width to be bonded to the substrate 20 can also be adopted.

  In either case of FIGS. 1 and 2, it is desirable that the strength required to peel off the first and second laminates (the resin film 14 on which the transparent electrode 15 is formed) is 4 N / 25 mm or more.

  Moreover, it is preferable that the seal portion 12 further has an ultraviolet shielding function, and the transmittance of light (ultraviolet rays) having a wavelength of 380 nm is in a range of 0% to 60%. Thereby, it can prevent that the light control layer 13 deteriorates when an ultraviolet-ray injects from the peripheral part of the light control body 10. FIG. In order to obtain the seal portion 12 having such characteristics, it is desirable that an ultraviolet absorber is added to the sealing material.

  Any conventionally known ultraviolet absorber can be used. Specifically, for example, inorganic ultraviolet absorbers such as titanium oxide, zinc oxide, cerium oxide, etc. and organic ultraviolet absorbers such as benzotriazole, triazine, and benzophenone are appropriately selected and used alone or in combination of two or more. Can be used as a mixture.

  By providing the sealing portion 12 as described above, it is possible to provide a light control film 10 and a light control device that are extremely high in design and highly reliable with problems such as deterioration suppressed.

  FIG. 3 shows an example in which the dimmer 1 is provided with an AC power supply 31 and a control unit 32 in the dimmer 10 for practical use.

  The AC power supply 31 is connected to the control unit 32, and the voltage supplied (applied) to the transparent electrode 15 provided on the light control film 10 is controlled by the control unit 32.

  For example, by turning on or off the voltage applied to the light control body 10, the alignment state of the liquid crystal material in the light control layer 13 can be controlled, and the light control film 10 can be in a transparent state or a scattering state. It becomes possible to control the haze (whiteness) of the light control film.

  The light control device 1 obtained as described above can be used for various purposes such as building windows, automobile windows, sunroofs, and partitions.

  Hereinafter, the seal portion 14 according to the invention and the comparative examples in which the adhesiveness based on the scratch test specified in JIS R 3255, the tensile elastic modulus based on the tensile test specified in JIS K 7127, and the tensile strength are different. Will be described in detail.

<Example 1>
Two flexible resin film base materials with an ITO layer were prepared, and a spacer was applied to one of the base materials with a thickness of 25 μm (a gap in which liquid crystal is sandwiched).

Thereafter, the following liquid crystal composition is dropped onto the spacer coating surface by the ODF method, and then bonded so that the ITO surface of the other film base faces, and a metal halide lamp with an illuminance of 60 mW with a wavelength of 350 nm or less cut. Was used to irradiate ultraviolet rays at 7 J / cm ^{2 in} terms of 365 nm to obtain a liquid crystal display element serving as a light control film. The inside of the irradiation apparatus when irradiating a liquid crystal cell with ultraviolet rays was controlled at 25 ° C.

  A feeding portion for electrically controlling the light control layer from both transparent electrode layers (ITO) was formed at the end of the light control film where the liquid crystal layer was sandwiched.

  For each transparent electrode layer (ITO) on both sides, a notch is formed in one resin film, and the ITO on the other resin film side that becomes the connection region is exposed, and then a feeding electrode portion (conductive paste, A light control film formed by forming a conductive tape and soldering lead wires) was obtained. An electrode protective layer made of an ultraviolet curable epoxy resin or an ultraviolet curable acrylic resin is formed on the power supply electrode portion so as to cover the connection region as necessary, but is omitted in the examples and comparative examples.

  The light control film was cut into small pieces of 2.5 cm × 15 cm, and laminated and fixed on blue plate glass serving as a supporting substrate.

  In laminating and fixing, a sealing material (“seal described later”) is used so that the film thickness becomes 1.5 times the film thickness of the light control film from the end 2 mm of the light control film (small sample) to the outer 100 μm of the light control film. The sealing material 1 ”) was applied to form a seal portion, and the black light was irradiated until the tackiness of the surface disappeared, and the visual inspection was performed. The seal portion has the shape shown in FIG. 1 or FIG.

<Liquid crystal composition>
The liquid crystal composition includes a liquid crystal, a curable resin, a bifunctional monomer, and a monomer having at least one polar group selected from the group consisting of a hydroxy group, a carboxy group, and a phosphate group. As the liquid crystal, nematic liquid crystal, smectic liquid crystal, or cholesteric liquid crystal can be used.

<Encapsulant>
As a sealing material to be a seal part, a photocurable resin liquid containing a polythiol compound, a polyene compound having two or more carbon-carbon double bonds in one molecule, and a photopolymerization initiator was prepared. Examples of the polyene compound include allyl compounds, propenyl compounds, (meth) acrylate compounds, and the like, and polyene-polythiol resins and (meth) acrylate compounds can be used. In the present invention, six types of sealing materials having different prescriptions are prepared and referred to as “sealing material 1” to “sealing material 6”, respectively, and the following examples (all 12) and comparative examples (all 8). ).

<Examples 2 to 11>
<Comparative Examples 1-10>
Various combinations of types of sealing material, (a) part length, (b) part length, ratio (c / f) of sealing material thickness (c) to light control film thickness (f) Samples of 20 types (including Example 1) of the seal portions according to Examples 2 to 11 and Comparative Examples 1 to 10 having data were prepared and evaluated.

  The size of the seal part serving as an index is (a) ≦ 10 mm, (b) = 1 to 5 times the (a) part, (c) = the light control film excluding the seal part (FIG. 1B) 11) to 1 to 2 times the thickness.

  Regarding the adhesion, a sample in which the adhesion between the sealing material and the resin film based on the scratch test specified in JIS R 3255 and the adhesion between the sealing material and the blue sheet glass is 1.0 mN or more was determined as a non-defective product. .

  Regarding the tensile strength, a sample in which the tensile strength of the sealing material based on the tensile test specified in JIS K 7127 was 2.0 MPa or more was determined as a good product.

  About peel strength, it pulled at the speed | rate of 300 mm / min between the transparent conductive films of a light control film using the tensile tester, and measured the peel strength between transparent conductive films. At this time, those having a peel strength of 4 N / 25 mm or more were considered good.

  About the designability, the sample was observed with naked eyes from a distance of 1 m, and the designability was determined to be good when the sealing material was not noticeable.

  The evaluation results are shown in Table 1.

  In Examples 1 to 11, the above (a), (b), and (c / f) of the seal part are within the range of the indicators, and all the evaluation items of adhesion, tensile strength, peel strength, and designability are cleared. Yes.

  In Comparative Example 1, (a), (b), and (c / f) of the seal part are within the index numerical value range, but there is a problem with the physical properties of the sealing material 5, and it passes the evaluation items of tensile strength and peel strength. The judgment value has not been reached.

  In Comparative Example 2, (a), (b), and (c / f) of the seal portion are within the index numerical value range, but there is a problem with the physical properties of the sealing material 6, and the adhesion between the sealing material and the resin film, The evaluation value of peel strength has not reached the acceptance judgment value.

  In Comparative Example 3, (b) of the seal part is outside the index numerical value range (insufficient: 0.5 times a), and has not reached the pass determination value in the evaluation item of peel strength.

  In Comparative Example 4, (b) of the seal part is out of the index numerical value range (excess: 6 times a), and the pass evaluation is not performed in the design property evaluation item.

  In Comparative Example 5, (b) of the seal part is out of the index numerical value range (insufficient: 0.4 times a), and the pass evaluation is not performed in the design property evaluation item.

 In Comparative Example 6, (a) of the seal portion is out of the index numerical value range (excess: more than 10 mm), and the pass determination is not made in the design property evaluation item.

  In Comparative Example 7, (b) of the seal part is out of the index numerical value range (excess: more than 10 mm), and the pass determination is not made in the design property evaluation item.

  In Comparative Example 8, (a) and (b) of the seal portion are outside the index numerical value range (insufficient: less than 10 mm), and have not reached the pass judgment value in the evaluation item of peel strength.

  In Comparative Example 9, (c / f) of the seal part is outside the index numerical value range (insufficient: less than 1), and has not reached the pass judgment value in the evaluation item of the peel strength.

  In Comparative Example 10, (c / f) of the seal portion is out of the index numerical value range (excess: more than 2), and the pass evaluation is not performed in the design property evaluation item.

DESCRIPTION OF SYMBOLS 1 ... Light control apparatus 10 ... Light control film 11 ... Light control film (except a seal part)
12 ... Sealing part 13 ... Light control layer (liquid crystal layer)
DESCRIPTION OF SYMBOLS 14 ... Transparent film 15 ... Transparent electrode 20 ... AC power supply, support member of control part 31 ... AC power supply 32 ... Control part

Claims (6)

A light control layer is sandwiched between first and second laminates having at least a transparent electrode layer on a resin film, and the transmitted light is modulated by modulating the light control layer by electrical control to control transmitted light. In the light control body formed by laminating and fixing the optical film on the glass substrate,
In the peripheral part including the four corners of the rectangular light control film, it has a seal part that covers the side end face where the laminated structure is exposed,
The sealing part is formed by applying a sealing material so as to cover the side end surface,
The seal portion includes a portion (a) that extends on the resin film from the side end portion where the laminated structure of the light control film is exposed, and a portion (b) that extends from the end portion in the peripheral direction outside the resin film. The length of each part is such that (a) and (b) are 1 mm or more and 10 mm or less, and (b) is 1 to 5 times as long as (a). Dimmer to do.   The thickness (c) of the sealing material in the laminating direction of the light control film is 1 to 2 times the thickness (f) of the light control film excluding the sealing portion. The light control body of 1.   The light control body according to claim 1 or 2, wherein the strength required for peeling off the first and second laminates is 4 N / 25 mm or more.   The light control body according to any one of claims 1 to 3, wherein the adhesiveness between the sealing material and the resin film based on the scratch test defined in JIS R 3255 is 1.0 mN or more.   The light control body according to any one of claims 1 to 4, wherein the tensile strength of the sealing material based on a tensile test specified in JIS K 7127 is 2.0 MPa or more.   The light control body according to claim 1, further comprising an alignment layer between the light control layer and the transparent conductive film.