JPWO2015111562A1 - Light control sheet and light control plate - Google Patents

Abstract

The main purpose is to provide a light control sheet and a light control plate excellent in weather resistance and durability. In the present invention, two or more regions that change the polarization state or phase state of transmitted light are disposed on a surface of one of the light control layer and a light control layer formed in a constant shape with a constant interval. A weather-resistant adhesive layer, wherein the weather-resistant adhesive layer is an adhesive polymer obtained by crosslinking an acrylic copolymer and a metal chelate crosslinking agent or an isocyanate-based crosslinking agent, and light at a wavelength of 380 nm. It is a light control sheet characterized by including an ultraviolet absorber having a transmittance of 60% or less.

Description

  The present invention relates to a light control sheet and a light control plate having a light control function.

  2. Description of the Related Art Conventionally, there is known a light control plate that adjusts the amount of incident light by changing the light transmittance by applying an external force such as a voltage.

As such a light control plate, for example, a light control sheet in which a light control layer in which a light control suspension in which oriented particles capable of responding to voltage are dispersed is dispersed in a resin matrix is sandwiched between transparent conductive substrates Is provided on the surface of the transparent substrate (see Patent Document 1). This is to switch the display by applying a voltage to the light control sheet and adjusting the amount of transmitted light according to the response of the oriented particles to the voltage.
Specifically, when a voltage is applied to the light control sheet, the oriented particles in the light control layer are oriented, so that incident light can pass through the light control sheet, and the light control plate is transparent so that the outside can be clearly seen. State (hereinafter referred to as a bright state).
On the other hand, in a state where no voltage is applied to the light control sheet, the oriented particles are not oriented, so that incident light is absorbed, scattered or reflected by the Brownian motion of the oriented particles. Therefore, light cannot pass through the light control sheet, and the light control plate is in a state where the outside cannot be visually recognized due to light shielding (hereinafter referred to as a dark state).

However, the light control sheet requires a long time to shift the oriented particles to the oriented state by applying a voltage, or to stop the application of the voltage and to move the oriented particles to a non-oriented state. There is a problem that it is difficult to instantaneously switch between the state and the bright state.
In addition, it is necessary to use together with an electrode layer having wiring or the like in order to apply a voltage, and further, since power for applying a voltage is also necessary, the cost for installing and using the light control plate increases. It was difficult to use easily.

On the other hand, development of a light control plate that does not require voltage application and can easily adjust the amount of incident light has been underway.
For example, in Patent Document 2, a transparent substrate has a pattern retardation layer in which a plurality of retardation regions different in at least one of a polarizing plate, an in-plane slow axis, and a retardation are formed in stripes at regular intervals. There is disclosed a light control glass in which two light control parts are arranged such that pattern phase difference layers of the light control parts face each other. In this case, the light control layer refers to a laminate including the polarizing plate and the pattern retardation layer.
In such a light control glass, it is possible to switch the display by sliding one of the two light control parts and changing the correspondence of the pattern of the retardation region in both pattern retardation layers. It becomes. Hereinafter, the light control glass using such a slide mechanism may be referred to as “slide light control glass”.

FIG. 6 is an explanatory diagram for explaining the light control function of the slide-type light control glass. Here, the pattern retardation layers 40A and 40B in FIG. 6 have a pattern in which the first retardation regions O1 and O1 ′ and the second retardation regions O2 and O2 ′ are alternately formed in a stripe shape. The in-plane slow axes a of the first phase difference regions O1 and O1 ′ and the second phase difference regions O2 and O2 ′ have an orthogonal relationship. Further, the in-plane retardations of the first retardation regions O1, O1 ′ and the second retardation regions O2, O2 ′ indicate λ / 4. Further, it is assumed that the polarizing plates 50A and 50B have orthogonal polarization axes. In addition, illustration is abbreviate | omitted about glass.
As shown in FIG. 6A, when light is transmitted from the light control unit 60A to the light control unit 60B, the polarizing plate 50A has the same direction as the polarization axis direction Y of the polarizing plate 50A from the incident light L1. Only the linearly polarized light L2 oscillating in the direction is transmitted. The linearly polarized light L2 is converted into circularly polarized light L3 in which the phase difference of λ / 4 is rotated in the opposite direction in the first retardation region O1 and the second retardation region O2 of the pattern retardation layer 40A. The circularly polarized light L3 is incident on the dimming unit 60B, and the phase difference of λ / 4 is further rotated in the opposite directions in the first retardation region O1 ′ and the second retardation region O2 ′ of the pattern retardation layer 40B. It is converted into linearly polarized light L4.
At this time, since the pattern retardation layers 40A and 40B have the same in-plane slow axis direction, that is, the same orientation direction, for example, the first retardation regions O1 and O1 ′ having the corresponding relationship, The direction of rotation is the same. That is, the linearly polarized light L4 is obtained by rotating the vibration direction of the linearly polarized light L2 by 90 °.
For this reason, since the vibration direction of the linearly polarized light L4 is the same as the polarization axis direction X of the polarizing plate 50B, it can be transmitted through the polarizing plate 50B, and the sliding light control glass 100 is brightened by the emitted light L5. It becomes a state.

On the other hand, FIG. 6B shows an example in which the light control unit 60B of FIG. 6A is slid in a direction orthogonal to the phase difference region pattern. In this case, in the pattern phase difference layers 40A and 40B, for example, the first phase difference region O1 and the second phase difference region O2 ′ that are in a corresponding relationship have the in-plane slow axis directions orthogonal to each other. The direction of rotation is reversed. That is, the circularly polarized light whose phase difference is rotated by λ / 4 in the first phase difference region O1 is rotated in the opposite direction by λ / 4 in the second phase difference region O2 ′, and the linearly polarized light L4 is linear. This is the same as the vibration direction of the polarized light L2.
For this reason, the vibration direction of the linearly polarized light L4 is orthogonal to the polarization axis direction X of the polarizing plate 50B, cannot pass through the polarizing plate 50B, and the sliding light control glass 100 is in a dark state.

JP 2013-210670 A International Publication No. 2012/092443 Japanese Patent No. 4881208

  By the way, the light control plate is usually used as a member on which light such as a window glass is incident, for the purpose of adjusting solar radiation and ensuring privacy. However, the above-mentioned slide-type light control glass has a problem that the light control layer easily absorbs ultraviolet rays or the like contained in the transmitted light and thus easily deteriorates, and the light control function decreases with time. Further, when a weathering agent such as an ultraviolet absorber is added to the light control layer, there is a problem that discoloration of the light control layer occurs. The reason for this is not necessarily clear, but it is considered that discoloration occurs when the weathering agent reacts with other materials constituting the light control layer in the light control layer.

For the above problem, the inventors of the present invention provide a light control sheet comprising a light control layer and an adhesive layer for bonding the light control layer to an adherend such as glass. The above-mentioned adhesive layer is made into a weather-resistant adhesive layer containing the above-mentioned weathering agent without adding any weathering agent, and studies are being made to improve the weather resistance and durability of the entire light control sheet.
This is because the light control layer does not contain a weathering agent such as an ultraviolet absorber, so that it is possible to prevent discoloration of the light control layer due to the inclusion of the weathering agent, and to the light incident on the light control sheet. Further, it is based on the idea that light deterioration of the light control layer can be prevented by absorbing light having a wavelength that causes deterioration of the light control layer such as ultraviolet rays in the weather resistant adhesive layer. In addition, since the weatherproof adhesive layer contains a weathering agent, the weatherability of the weatherproof adhesive layer itself can be improved, so it is assumed that the weather resistance and durability of the entire light control sheet are improved.

  In Patent Document 3, as a pressure-sensitive adhesive used when a light-transmitting film is bonded to a window glass or the like, a (meth) acrylic acid ester-based copolymer having a carboxyl group, a metal chelate-based crosslinking is used. It has been disclosed that by using a weather-resistant adhesive containing an agent and a triazine-based ultraviolet absorber, the ultraviolet deterioration of the weather-resistant adhesive is used to suppress the photodegradation of the bonded film.

  However, even when the one disclosed in Patent Document 3 is used as the weather-resistant adhesive layer positioned on the light incident side of the light control layer, the weather control and durability of the entire light control sheet are sufficiently improved. There is a problem that it cannot be achieved.

  The present invention has been made in view of the above circumstances, and a main object thereof is to provide a light control sheet and a light control plate that are excellent in weather resistance and durability.

  As a result of diligent studies to solve the above problems, the present inventors have found that the type of ultraviolet absorber contained in the weather resistant adhesive layer as a weather resistant agent contributes to the suppression of deterioration of the light control layer. I found it. Among them, the present inventors absorb the wavelength light that causes the deterioration of iodine, and that the main factor of the deterioration of the light control layer is due to the deterioration of iodine contained in the polarizing plate constituting the light control layer. It has been found that the weather resistance and durability of the entire light control sheet can be improved by selecting the ultraviolet absorber, and the present invention has been completed.

That is, the present invention includes a light control layer in which two or more regions that change the polarization state or phase state of transmitted light are formed in a fixed shape at a fixed interval, and is disposed on one surface of the light control layer. An adhesive polymer obtained by crosslinking an acrylic copolymer and a metal chelate crosslinking agent or a crosslinking agent of an isocyanate crosslinking agent, and a wavelength of 380 nm. Provided is a light control sheet comprising an ultraviolet absorber having a light transmittance of 60% or less.
In the present specification, the ultraviolet absorber “having a light transmittance of 60% or less at a wavelength of 380 nm” may be referred to as “(predetermined) optical properties”. .

  According to the present invention, since the weather-resistant adhesive layer includes the above-described composition, among the light incident on the light control sheet, wavelength light that causes deterioration of the material constituting the light control layer, especially the light control layer is configured. The wavelength light which causes the deterioration of iodine contained in the polarizing plate to be performed can be selectively and sufficiently absorbed in the ultraviolet absorbent exhibiting the optical characteristics in the weather-resistant adhesive layer. Thereby, it is possible to suppress the deterioration of iodine that contributes most to the deterioration of the light control layer, and as a result, it is possible to suppress the light deterioration of the light control layer. Moreover, when the weather-resistant adhesive layer contains the above-described composition, it is possible to suppress the light deterioration of the weather-resistant adhesive layer itself. Thereby, it can be set as the light control sheet | seat with high weather resistance.

  In the said invention, it is preferable that the said ultraviolet absorber is a benzotriazole type ultraviolet absorber. Since the wavelength band of light that can be absorbed by the UV absorber can overlap with the wavelength band of the wavelength light that causes deterioration of the material that constitutes the light control layer, it can more effectively improve the weather resistance of the light control layer. This is because it can be improved.

  In the said invention, the said light control layer has a pattern phase difference layer and the polarizing plate arrange | positioned at the said weather-resistant adhesion layer side rather than the said pattern phase difference layer, and the said pattern phase difference layer is a transparent film. A substrate, an alignment layer formed on the transparent film substrate, and a retardation layer formed on the alignment layer, wherein the retardation layer comprises an in-plane slow axis direction and a retardation. It is preferable that at least one of the two or more phase difference regions different from each other is formed in a constant shape at a constant interval. Since the light control layer has such a configuration, the light control plate including the light control sheet of the present invention can be easily designed as a slide mechanism, and the operation of the light control plate is facilitated. It is.

  Moreover, this invention has a 1st light control part which has a 1st light control sheet, and a 2nd light control part which has a 2nd light control sheet, The said 1st light control part and the said 2nd light control part However, the first light control sheet and the second light control sheet are arranged so as to face each other with a space, the first light control sheet and the second light control sheet, An adhesive layer and at least a light control layer formed on the adhesive layer, wherein the light control layer has a constant distance between two or more regions that change the polarization state or phase state of transmitted light. The adhesive layer of at least one of the first light control sheet and the second light control sheet is formed of an acrylic copolymer and a cross-linking agent of a metal chelate cross-linking agent or an isocyanate cross-linking agent. Polymer having a crosslinked structure, and light at a wavelength of 380 nm A weather-resistant adhesive layer containing an ultraviolet absorber having a transmittance of 60% or less, wherein at least one of the first light control part and the second light control part intersects with the region of the light control layer Provided is a light control plate that is movable in a direction.

  According to the present invention, since the light control sheet in at least one of the first light control section and the second light control section includes the weather resistant adhesive layer having the above-described composition, the weather control adhesive layer is provided. By arranging the light control part on the light incident side, wavelength light that causes deterioration of the material constituting the light control layer, particularly wavelength light that causes deterioration of iodine contained in the polarizing plate that constitutes the light control layer, First, it can be selectively and sufficiently absorbed in the ultraviolet absorbent exhibiting the optical characteristics in the weather-resistant adhesive layer. Thereby, it is possible to suppress the deterioration of iodine that contributes most to the deterioration of the light control layer, and as a result, it is possible to suppress the light deterioration of the light control layer in each light control unit. In addition, since the weather resistant adhesive layer has the above-described composition, light deterioration of the weather resistant adhesive layer itself can be suppressed, so that a light control plate having high durability and weather resistance can be obtained.

  In the said invention, the said 1st light control part is provided with the said 1st light control sheet | seat on one surface of a 1st transparent substrate, The said 2nd light control part is a 2nd transparent substrate. It is preferable that the second light control sheet is provided on one surface. This is because, for example, when the light control plate of the present invention is arranged in a wide area, it is possible to improve the mechanical strength of each light control unit.

  In the invention, the light control layer has a polarizing plate disposed on the adhesive layer side of the pattern retardation layer and the pattern retardation layer, and the pattern retardation layer comprises a transparent film substrate, It has an alignment layer formed on the transparent film substrate and a retardation layer formed on the alignment layer, and the retardation layer has at least one of the direction of the in-plane slow axis and the retardation. It is preferable that two or more different retardation regions are formed in a fixed shape with a fixed interval. By having the light control layer with such a configuration, the light control plate of the present invention can be easily designed as having a slide mechanism, and the operation of the light control plate is facilitated.

  In the light control sheet of the present invention, in the weather-resistant adhesive layer having a desired composition, the light having a wavelength that causes deterioration of the light control layer is selectively absorbed by an ultraviolet absorbent having predetermined optical characteristics, thereby adjusting the light control sheet. Since the deterioration of the light layer is suppressed and the light deterioration of the weather-resistant adhesive layer itself can be suppressed, there is an effect of having high weather resistance and durability.

It is the schematic plan view and sectional drawing which show an example of the light control sheet | seat of this invention. It is explanatory drawing for demonstrating the light control function by the light control sheet of this invention. It is a schematic sectional drawing which shows an example of the light control layer in this invention. It is a schematic sectional drawing which shows the other example of the light control sheet of this invention. It is the schematic side view and top view which show an example of the light control board of this invention. It is explanatory drawing explaining the light control function in slide type light control glass.

  Hereinafter, the light control sheet and the light control plate of the present invention will be described in detail.

A. Light control sheet The light control sheet of the present invention includes a light control layer in which two or more regions that change the polarization state or phase state of transmitted light are formed in a fixed shape with a fixed interval, and the light control layer An adhesive polymer formed by crosslinking an acrylic copolymer and a metal chelate cross-linking agent or a cross-linking agent of an isocyanate cross-linking agent. And an ultraviolet absorber exhibiting predetermined optical characteristics.

The light control sheet of this invention is demonstrated with reference to figures. FIG. 1A is a schematic plan view showing an example of the light control sheet of the present invention, and a part of the weather-resistant adhesive layer is omitted for explanation. Moreover, FIG.1 (b) is the XX sectional view taken on the line of Fig.1 (a).
The light control sheet 10 of the present invention is obtained by laminating at least a weather-resistant adhesive layer 1 and a light control layer 2. The weather-resistant adhesive layer 1 includes an adhesive polymer obtained by crosslinking an acrylic copolymer and a metal chelate crosslinking agent or an isocyanate crosslinking agent, and an ultraviolet absorber exhibiting predetermined optical characteristics.
The light control layer 2 is formed by alternately forming regions P1 and P2 for changing the polarization state or phase state of transmitted light in a constant shape (a stripe shape in FIG. 1) with a constant interval D. . That is, the plurality of regions P1 and P2 have a constant width D and a constant shape, and the plurality of regions P1 or regions P2 are alternately arranged so as to contact each other without a gap. Between the two adjacent regions P1 or between the two regions P2, there is a certain distance D corresponding to the width D of the region P2 or region P1 located between them.
The light control sheet 10 shown in FIG. 1 can exhibit the effects of the present invention by using the weather resistant adhesive layer 1 on the light L incident side rather than the light control layer 2.
In the following description, in the light control sheet and the light control layer, each region formed in a fixed shape with a fixed interval may be referred to as a “pattern region”.

As shown in FIG. 2, the light control sheet of the present invention is obtained by bonding the two light control sheets 10 </ b> A and 10 </ b> B to the adherends 11 </ b> A and 11 </ b> B such as window glass so as to face each other. It is used for a slide-type light control plate that slides one side of 10B. The light control plate changes the light transmittance and adjusts the amount of transmitted light by changing the correspondence between the pattern regions P1 and P2 in the light control sheet 10A and the pattern regions P1 and P2 in the light control sheet 10B. Thus, the display can be switched.
That is, as shown in FIG. 2A, the pattern region P1 in the light control sheet 10A and the pattern region P1 in the light control sheet 10B, and the pattern region P2 in the light control sheet 10A and the pattern region P2 in the light control sheet 10B correspond to each other. to case, the incident light L _in is transmitted through the light control plate may be a bright state more dimming plate emitted light L _out. On the other hand, as shown in FIG. 2B, the pattern region P1 in the light control sheet 10A and the pattern region P2 in the light control sheet 10B, and the pattern region P2 in the light control sheet 10A and the pattern region P1 in the light control sheet 10B correspond to each other. to case, the incident light L _in is not capable of transmitting light control plate may be a light control plate in a dark state.
In addition, in order to simplify description, in FIG. 2, illustration is abbreviate | omitted about structures other than the pattern area | regions P1 and P2 in the light modulation sheets 10A and 10B.

In the light control sheet used for the light control plate as described above, when the weather control agent such as an ultraviolet absorber is contained in the light control layer, the light control layer is usually discolored. Cannot add weathering agents.
Therefore, the inventors of the present invention have adopted a weather-resistant adhesive layer containing a weathering agent as an adhesive layer to be bonded to an adherend such as a window glass located on the light incident side, and the light control layer is deteriorated. Investigations are being made to prevent deterioration of the light control layer by first absorbing the wavelength light that causes it in the weatherproof adhesive layer. At this time, since the weather-resistant adhesive layer itself also contains a weathering agent, it is possible to improve the weather resistance, and it is expected that the light-adjusting sheet is excellent in weather resistance and durability.
However, even with the light control sheet as described above, there is a problem in that the light control layer is deteriorated over time and the light control function cannot be maintained over a long period of time.

In order to solve the above problems, the present inventors have made extensive studies on the combination of the light control layer and the weather resistant adhesive layer, and as a weathering agent contained in the weather resistant adhesive layer, the light having a specific wavelength is used. It has been found that the deterioration of the light control layer is sufficiently suppressed by selecting an ultraviolet absorber having a light transmittance of a predetermined value or less. The reason is presumed as follows.
That is, the dimming layer has a layer configuration such as a polarizing plate or a pattern retardation layer in order to change the polarization state or phase state of transmitted light. The iodine contained in the polarizer of the polarizing plate, the surface of the polarizing plate Deterioration of the polarizing plate protective film and the liquid crystal constituting the pattern retardation layer provided on the substrate is accelerated by absorbing specific wavelength light among wavelength light such as ultraviolet rays. For this reason, due to the light deterioration of the material contained in the layer which comprises a light control layer, deterioration of the whole light control layer will arise.
Among them, as a result of intensive studies on the cause of deterioration of the light control layer by the present inventors, the deterioration of iodine contained in the polarizer of the polarizing plate constituting the light control layer is the largest in the deterioration of the entire light control layer. In addition, it has been found that iodine promotes deterioration by absorbing light in the vicinity of a wavelength of 380 nm.
On the other hand, ultraviolet absorbers have different wavelength bands that can be specifically absorbed depending on the type of the ultraviolet absorbers, and deteriorate the wavelength bands that can be specifically absorbed by ultraviolet absorbers and the respective materials constituting the above-mentioned light control layer. By overlapping the wavelength band of the specific wavelength light, it is possible to selectively and sufficiently absorb the wavelength light that causes the deterioration of each layer constituting the light control layer, and to suppress the deterioration of the entire light control layer. It is guessed.
Here, as described above, since the deterioration of iodine contained in the polarizer of the polarizing plate contributes most to the deterioration of the light control layer, it promotes the deterioration of iodine as an ultraviolet absorber contained in the weather-resistant adhesive layer. By selecting an ultraviolet absorber that does not easily transmit light having a wavelength of 380 nm, the ultraviolet light absorber selectively and sufficiently absorbs the wavelength light that causes the deterioration of iodine, and iodine absorbs light having the above wavelength. Can be prevented. Further, the wavelength light that causes the deterioration of the material constituting the light control layer is also absorbed to some extent by overlapping with a part of the absorption wavelength band of the ultraviolet absorber. Thereby, it is estimated that deterioration of the whole light control layer can be suppressed.

That is, according to the present invention, since the weather-resistant adhesive layer includes the above-described composition, out of the light incident on the light control sheet, the wavelength light that causes deterioration of the material constituting the light control layer, particularly the light control layer The wavelength light which causes the deterioration of iodine contained in the polarizing plate constituting the above can be selectively and sufficiently absorbed in the ultraviolet absorbent showing the optical characteristics in the weather-resistant adhesive layer. Thereby, it is possible to suppress the deterioration of iodine that contributes most to the deterioration of the light control layer, and as a result, it is possible to suppress the light deterioration of the light control layer.
Moreover, when the weather resistant adhesive layer contains the above-described composition, the ultraviolet absorber can also suppress the light deterioration of the weather resistant adhesive layer itself. Thereby, it can be set as the light control sheet | seat with high weather resistance.

In the present specification, in the light control layer, two or more regions that change the polarization state or phase state of transmitted light are formed in a certain shape with a certain interval. It means that two or more regions that change state are continuously formed with a certain width and a certain shape. That is, each area | region has the same width | variety and shape, and each area | region is arrange | positioned continuously by adjacent areas. In addition, from the arrangement mode at this time, the fact that the regions are spaced apart from each other means that the length connecting the centers of two adjacent regions usually corresponds to the width of the region.
Specifically, the first region and the second region that change the polarization state or phase state of the transmitted light have a certain width and a certain shape, and are adjacent to each other so that both regions are alternately arranged. The three or more regions that change the polarization state or phase state of transmitted light have a certain width and a certain shape, and are formed adjacent to each other so that each region is repeatedly arranged. In addition, a plurality of regions that change the polarization state or phase state of transmitted light have a certain width and a certain shape, and are formed adjacent to each other so that the polarization state or phase state gradually changes. It means that
Regarding the definition that “two or more regions are formed in a certain shape with a certain interval”, the retardation region in the retardation layer, the alignment region in the alignment layer, and the polarizing region in the polarizing plate described later also apply. The same shall apply.

  Hereinafter, each part of the light control sheet of this invention is demonstrated.

1. Weather-resistant adhesive layer The weather-resistant adhesive layer in the present invention is disposed on one surface of the light control layer, and an acrylic copolymer and a metal chelate crosslinking agent or an isocyanate-based crosslinking agent are crosslinked. And an ultraviolet absorber exhibiting predetermined optical characteristics.

  By including the above-described composition, the weather-resistant adhesive layer can suppress the light deterioration of the weather-resistant adhesive layer itself and the entire light control sheet by the ultraviolet absorber. In addition, depending on the type of weathering agent contained in the weathering adhesive layer, the weathering colored layer itself may exhibit a color and the light transmittance of the light control sheet may decrease. When the layer contains an ultraviolet absorber exhibiting predetermined optical characteristics, it is possible to prevent coloration due to the weathering agent and to exhibit high light transmittance.

(1) Adhesive polymer The adhesive polymer in the weather-resistant adhesive layer is obtained by crosslinking an acrylic copolymer and a crosslinking agent of a metal chelate crosslinking agent or an isocyanate crosslinking agent.

(A) Acrylic copolymer The acrylic copolymer is an adhesive main agent, and is preferably one that is crosslinked by heating during a crosslinking reaction with a crosslinking agent described later. This is because in the case of crosslinking by light irradiation, the weather resistance of the weather-resistant adhesive layer after curing may be affected.
Examples of the acrylic copolymer include an acrylic ester copolymer obtained by copolymerizing a (meth) acrylic ester as a main component and a (meth) acrylic monomer.
In addition, (meth) acrylic acid ester means acrylic acid ester or methacrylic acid ester. The same applies to the (meth) acrylic monomer in the following description.

  Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Isobutyl, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, neopentyl (meth) acrylate, Hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate , Decyl (meth) acrylate, isodecyl (meth) acrylate, (me ) Undecyl acrylate, and (meth) dodecyl acrylate. These may be used alone or in combination of two or more. Among them, in the invention, butyl acrylate, isobutyl acrylate, t-butyl acrylate, butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate are preferable.

Examples of the (meth) acrylic monomer include monofunctional (meth) acrylate, bifunctional to tetrafunctional polyfunctional (meth) acrylate, and the like. About these (meth) acrylic monomers, what has a functional group which becomes a crosslinking point with the crosslinking agent mentioned later and copolymerizes with acrylic ester is preferable.
Examples of the functional group serving as a crosslinking point include a hydroxyl group, a carboxyl group, an amide group, an amino group, an epoxy group, and a cyano group. In the (meth) acrylic monomer, one of these functional groups is included in the molecular structure. It is preferable to have 1 type to 4 types as a whole.

  Examples of the hydroxyl group-containing (meth) acrylic monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate, and the like.

  Examples of the carboxyl group-containing (meth) acrylic monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and isocrotonic acid.

  Examples of the amide group-containing (meth) acrylic monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-methylolpropane (meth). Examples include acrylamide, N-methoxymethyl (meth) acrylamide, and N-butoxymethyl (meth) acrylamide.

  Examples of the amino group-containing (meth) acrylic monomer include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, and the like.

  Examples of the epoxy group-containing (meth) acrylic monomer include glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate.

  Examples of the cyano group-containing acrylic monomer include acrylonitrile and methacrylonitrile.

  Examples of other (meth) acrylic monomers include 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol. Di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meta) ) Acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin (Meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di (meth) acrylate, and polyfunctional monomers such as hexyl di (meth) acrylate. Furthermore, vinyl esters such as vinyl acetate, styrene monomers such as styrene and α-methylstyrene, acrylic monomers of the above-mentioned (meth) acrylic acid esters and the like can be mentioned.

  Among them, as the (meth) acrylic monomer constituting the acrylic copolymer, butyl acrylate, isobutyl acrylate, t-butyl acrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate and the like are preferably used. It is done.

The acrylic copolymer is not particularly limited with respect to the copolymerization form, and may be any of a random copolymer, a block copolymer, and a graft copolymer. Preferably there is.
In addition, the weight average molecular weight (Mw) of the acrylic copolymer is not particularly limited as long as the weather-resistant adhesive layer in the present invention can exhibit a desired adhesive force. For example, the weight average molecular weight (Mw) is, for example, in the range of 200000 to 1400000, especially 600000. It is preferable to be within a range of ˜1000000, particularly within a range of 750000 to 850,000. If the weight average molecular weight is smaller than the above range, the adhesive force may decrease with a decrease in cohesive force. On the other hand, when the weight average molecular weight is larger than the above range, the light control sheet of the present invention can be firmly bonded to the adherend, but the adhesive force is too high and it is difficult to peel off from the adherend when it is replaced. There is a case.
In addition, the said weight average molecular weight is a value of polystyrene conversion at the time of measuring by gel permeation chromatography (GPC), and three LF-804 made by Showa Denko KK is used for the measurement, and THF is used as a developing solvent. Shall be used.

  In addition, the content ratio of the acrylate ester and the (meth) acryl monomer in the acrylic copolymer is not particularly limited as long as the acrylate ester is a main component, and the weather resistant adhesive layer in the present invention has a desired adhesive strength. It can be appropriately set so as to exhibit weather resistance and optical properties.

(B) Crosslinking agent The said crosslinking agent is either a metal chelate crosslinking agent or an isocyanate type crosslinking agent.

(I) Metal chelate crosslinking agent As the metal chelate crosslinking agent, those having a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium as the central metal are preferable. Among these, an aluminum chelate cross-linking agent whose center metal is aluminum is particularly preferable.

  Examples of the aluminum chelate crosslinking agent include diisopropoxy aluminum monooleyl acetoacetate, monoisopropoxy aluminum bis oleyl acetoacetate, monoisopropoxy aluminum monooleate monoethyl acetoacetate, diisopropoxy aluminum monolauryl acetoacetate, diisopropoxy Aluminum monostearyl acetoacetate, diisopropoxy aluminum monoisostearyl acetoacetate, monoisopropoxy aluminum mono-N-lauroyl-β-alanate monolauryl acetoacetate, aluminum trisacetylacetonate, monoacetylacetonate aluminum bis (isobutylacetate Acetate) chelate, monoacetylacetonate aluminum bis (2- Ethylhexyl acetoacetate) chelate, monoacetylacetonate aluminum bis (dodecyl acetoacetate) chelate, monoacetylacetonate aluminum bis (oleyl acetoacetate) chelate, and the like.

  Other metal chelate crosslinking agents include, for example, titanium tetrapropionate, titanium tetra-n-butyrate, titanium tetra-2-ethylhexanoate, zirconium-sec-butyrate, zirconium diethoxy-tert-butyrate, tri Examples include ethanolamine titanium dipropionate, ammonium lactate ammonium salt, and tetraoctylene glycol titanate.

  The above-mentioned metal chelate crosslinking agents may be used alone or in combination of two or more.

(Ii) Isocyanate-based crosslinking agent Examples of the isocyanate-based crosslinking agent include a polyisocyanate compound, a trimer of a polyisocyanate compound, and a urethane prepolymer having an isocyanate group at the end obtained by reacting a polyisocyanate compound and a polyol compound. Or trimers of such urethane prepolymers. The polyisocyanate compound is not particularly limited, and 2,4-tolylene diisocyanate, 2,5-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4′- Examples include diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethane-2,4′-diisocyanate, and lysine isocyanate.
One of the above isocyanate-based crosslinking agents may be used alone, or two or more thereof may be used in combination.

(Iii) Others The content of the metal chelate crosslinking agent or the crosslinking agent of the isocyanate-based crosslinking agent is in the range of 1 to 30 parts by mass, particularly 3 parts by mass to 100 parts by mass of the acrylic copolymer. It is preferable to be within the range of 20 parts by mass, particularly within the range of 5 to 15 parts by mass. When the content of the above-mentioned crosslinking agent is more than the above range, the crosslinking reaction with the acrylic copolymer is excessively promoted and the curing becomes too dense, so that the weather-resistant adhesive layer is likely to deteriorate, The weather resistance as a light control sheet may fall. Moreover, there exists a possibility that a weather-resistant contact bonding layer may become cloudy.
On the other hand, when the content of the cross-linking agent is less than the above range, the cross-linking reaction is not sufficiently performed and the curing becomes too sparse, so that the curing is insufficient and the adhesive force may be reduced.

(C) Arbitrary composition The adhesive polymer is formed by crosslinking the above-mentioned acrylic copolymer and a crosslinking agent of a metal chelate crosslinking agent or an isocyanate-based crosslinking agent. Other polymers may be included and these may be crosslinked. For example, as an optional monomer, a hydroxyl group-containing (meth) acrylic monomer such as 2-hydroxypropyl acrylate can be used.

(2) Ultraviolet absorber The ultraviolet absorber contained in the weather-resistant adhesive layer has a predetermined optical characteristic, that is, a light transmittance of 60% or less at a wavelength of 380 nm. Of the wavelength light that causes deterioration of the material constituting the light control layer, the wavelength light that causes deterioration of iodine contained in the polarizing plate that constitutes the light control layer, because the transmittance is within the above-mentioned range. This is because selective and sufficient absorption can be achieved, and deterioration of the entire light control layer can be suppressed.
In particular, the transmittance of the above-mentioned wavelength light of the ultraviolet absorber is preferably 50% or less, and particularly preferably 30% or less. The lower limit of the transmittance is preferably 5% or more. When the transmittance of the wavelength light of the ultraviolet absorber is larger than the above range, deterioration of the light control sheet due to ultraviolet rays may be promoted, and the weather resistance may not be improved. On the other hand, if the transmittance of the above-mentioned wavelength light of the ultraviolet absorber is lower than the above range, the weather-resistant adhesive layer becomes yellowish due to inhibition of visible light transmission near the wavelength of 380 nm, etc. In some cases, the light transmittance at the time may be reduced.
The light transmittance of the ultraviolet absorber refers to the ratio (%) of the light intensity at the time of emission to the light intensity at the time of incidence of light of each wavelength that passes through the ultraviolet absorber, and the concentration is 0.006 mass. % Ultraviolet absorber solution (solvent: toluene) is prepared, the solution is injected into a glass cell having a width of 10 mm, and a xenon lamp is used as a light source, and measurement can be performed by a double beam photometry method. For the measurement, a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation) can be used, and the light transmittance with only the toluene solvent can be measured as a reference.

Further, in order to ensure that the weather-resistant adhesive layer has high transparency in the visible light region, and to ensure the light transmittance of the entire light control sheet, the ultraviolet absorber has a light transmittance in the visible light region. High is preferred. Specifically, the light transmittance in the visible light region of the ultraviolet absorber is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. If the transmittance of light in the visible light region by the ultraviolet absorber is lower than the above range, the weather-resistant adhesive layer becomes yellowish by absorbing visible light by the ultraviolet absorber, and the entire light control sheet In some cases, the light transmittance of the film is impaired.
The visible light region means a wavelength region of 380 nm to 780 nm, and the light transmittance in the visible light region of the ultraviolet absorber is the light transmittance in the wavelength region measured by the above method. Mean means.

The ultraviolet absorber is not particularly limited as long as it exhibits the above-described optical characteristics, and a material generally used as an ultraviolet absorber can be used. The ultraviolet absorber may be inorganic or organic. Of these, organic ultraviolet absorbers are preferred because of their excellent transparency.
Examples of inorganic ultraviolet absorbers include titanium dioxide, cerium oxide, and zinc oxide.
On the other hand, examples of the organic ultraviolet absorber include benzotriazole ultraviolet absorbers, triazine ultraviolet absorbers, benzophenone ultraviolet absorbers, salicylate ultraviolet absorbers, benzoate ultraviolet absorbers, and cyanoacrylate ultraviolet absorbers. , Hydroxyphenyltriazine-based ultraviolet absorbers, nickel chelate-based ultraviolet absorbers, and the like. Among these ultraviolet absorbers, those showing the above-mentioned optical characteristics can be appropriately selected and used. Specifically, 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol (benzotriazole UV absorber, trade name: Tinuvin 928, manufactured by BASF), 2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3-5-triazine (Hydroxyphenyltriazine ultraviolet absorber, trade name: Tinuvin 460, manufactured by BASF), methyl-3- [3-tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate Condensate with polyethylene glycol (molecular weight 300) (benzotriazole ultraviolet absorber, trade name: Tinuvin 1130 , Manufactured by BASF).
Especially, it is preferable that the said ultraviolet absorber is a benzotriazole type ultraviolet absorber. Since the wavelength band of light that can be absorbed by the UV absorber can overlap with the wavelength band of the wavelength light that causes deterioration of the material that constitutes the light control layer, it can more effectively improve the weather resistance of the light control layer. This is because it can be improved.

  The ultraviolet absorber which shows the above-mentioned optical characteristic may be used independently, and may use 2 or more types together.

  As content of the ultraviolet absorber which shows the above-mentioned optical characteristic in a weather-resistant contact bonding layer, it is in the range of 0.1 mass part-25 mass parts with respect to 100 mass parts of acrylic copolymers, and especially 1 mass part- It is preferable to be in the range of 25 parts by mass, particularly in the range of 3 parts by mass to 20 parts by mass. When the content of the ultraviolet absorber exhibiting the above optical characteristics is larger than the above range, there may be a problem in appearance of the entire light control sheet due to coloring of the weather-resistant adhesive layer. On the other hand, if the content of the ultraviolet absorber exhibiting the above optical characteristics is less than the above range, the weather-resistant adhesive layer cannot sufficiently absorb the light having a wavelength of 380 nm, which promotes the deterioration of iodine, particularly in the ultraviolet ray. The optical layer may be easily deteriorated.

(3) Arbitrary materials The weather-resistant adhesive layer in the present invention may contain a light stabilizer and the like in addition to the above-mentioned composition from the viewpoint of further improving the weather resistance. The light stabilizer is preferably a hindered amine light stabilizer or the like, and may have a reactive group in the molecule. Examples of the light stabilizer include 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and bis (1,2 , 2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 2,4-bis [N-butyl-N- (1- Cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) amino] -6- (2-hydroxyethylamine) -1,3,5-triazine and the like.

  About content of the light stabilizer in a weather-resistant contact bonding layer, it should just exist in the range of 0 mass-7 mass parts with respect to 100 mass parts of acrylic copolymers, and is in the range of 0 mass parts-5 mass parts especially. It is preferable that it is in the range of 0 mass part-5 mass parts especially.

In addition, the weather-resistant adhesive layer in the present invention may include an infrared reflector or an infrared absorber. When using the light control sheet of this invention for a light control board, the said light control board will be in a dark state by light transmission being shielded. At this time, it is necessary to increase the black density in the dark state in order to completely shield the light, and it is necessary to suppress the transmission of wavelength light in a wide range including not only the visible light region but also the infrared region.
For this reason, it is preferable to suppress the transmission of infrared rays by adding an infrared reflecting agent or an infrared absorbing agent in the weather-resistant adhesive layer to reflect or absorb infrared rays.
Examples of the infrared reflecting agent include tin oxide, indium tin oxide, metal complex dye, and zinc oxide. Examples of the infrared absorber include titanium oxide, zinc oxide, indium oxide, tin-doped indium oxide (ITO), tin oxide, antimony-doped tin oxide (ATO), and zinc sulfide metal oxide-based infrared absorber. It is done. The kind of said infrared reflective agent and infrared absorber is an example, and is not limited to these materials.

  About content of the infrared reflector or infrared absorber in the said weather-resistant contact bonding layer, it is in the range of 0.1 mass part-20 mass parts with respect to 100 mass parts of acrylic copolymers, and 0.5 mass part-especially It is preferably within the range of 10 parts by mass, particularly within the range of 1 part by mass to 5 parts by mass. When the content of the infrared reflecting agent or the infrared absorbing agent is more than the above range, the transparency of the light control sheet of the present invention may be reduced, and the light transmittance may be reduced. In the light control board provided with the light control sheet of this invention, sufficient black density may not be obtained and shielding may be insufficient.

  Furthermore, the weather-resistant adhesive layer in the present invention may contain a silane coupling agent, an antioxidant, an adhesion-imparting agent, a filler, a leveling agent and the like as optional materials. The adhesion-imparting material is not particularly limited as long as it is generally used for a weather-resistant adhesive layer. For example, a rosin-based adhesion-imparting agent is suitable.

The weather-resistant adhesive layer in the present invention may contain an ultraviolet absorbent other than the ultraviolet absorbent exhibiting the optical characteristics described above, as long as it does not cause coloration of the weather-resistant adhesive layer. By including other ultraviolet absorbers with different absorption wavelength bands, light that causes deterioration of the materials that make up the light control layer other than iodine contained in the polarizing plate is absorbed, and light deterioration of the entire light control layer is efficiently performed. This is because it can be suppressed.
Specifically, it can be appropriately selected from the ultraviolet absorbers mentioned in the above-mentioned item “(2) Ultraviolet absorber” according to the wavelength of the wavelength light to be absorbed.
Further, for example, an ultraviolet absorber as an additive added for other uses other than the ultraviolet absorbing use such as a polymerizable compound and a polymerization initiator may be included.

(4) Others The gel fraction of the weather-resistant adhesive layer in the present invention is preferably in a range having an adhesive force capable of bonding the adherend and the light control sheet at a desired thickness, and after curing. Is preferably in the range of 50% to 90%, more preferably in the range of 60% to 85%, and particularly preferably in the range of 70% to 80%. When the gel fraction of the weather-resistant adhesive layer is larger than the above range, the crosslink density becomes high, so that the adhesive strength is high and the light control sheet of the present invention can be firmly bonded to the adherend. In some cases, the force is too high to make it difficult to peel off the adherend during reattachment. In addition, when the crosslinking density is too high, the weather-resistant adhesive layer may be easily deteriorated. On the other hand, if it is smaller than the above range, the desired adhesive strength may not be exhibited because the crosslinking density is low.
The gel fraction is a value measured by the following method.

(Measurement method of gel fraction)
A weather-resistant adhesive layer sandwiched between the separators is cut out at 10 cm × 10 cm square. The weight of the weathered adhesive layer that has been cut out is rolled and measured in a bottle, and the weight (initial weight) of the weatherable adhesive layer before treatment is measured from the difference between the weight of the separator and the bottle. Next, after immersing the weather-resistant adhesive layer in a bottle (MEK) that has been prevented from volatilizing and allowing it to stand for 3 hours, it is placed on a 100 cm net of 10 cm × 10 cm, which weighed in advance, and the waste liquid and The monomer eluted from the weather-resistant adhesive layer is discarded. Drying at 60 ° C. for 24 hours with the weather-resistant adhesive layer mounted, and measuring the total weight of the mesh mesh after drying and the weather-resistant adhesive layer after solvent immersion and drying, from the difference between the total weight and the initial weight The weight of the weather-resistant adhesive layer after drying (after treatment) excluding the weight of the mesh net is calculated, and the gel fraction is determined from the following formula.
Gel fraction (%) = {(weight of weather-resistant adhesive layer after treatment (g)) / (weight of weather-resistant adhesive layer before treatment (g))} × 100

  The thickness of the weather-resistant adhesive layer may be any size as long as it can contain the above-described desired amount of the UV absorber, for example, in the range of 5 μm to 80 μm, in particular in the range of 10 μm to 60 μm, particularly 15 μm. It is preferable to be within a range of ˜40 μm. When the thickness of the weather-resistant adhesive layer is larger than the above range, the light transmittance of the light control sheet may be deteriorated, the appearance may be deteriorated due to an increase in haze, and the bonding may be unfavorable. On the other hand, if the thickness of the weather-resistant adhesive layer is smaller than the above range, the desired amount of weathering agent cannot be included, or the desired adhesive strength cannot be obtained and the function as the light control sheet cannot be secured. There is.

The adhesive strength of the weather-resistant adhesive layer is preferably in the range of 4N / 25mm to 30N / 25mm, more preferably in the range of 4N / 25mm to 25N / 25mm, particularly in the range of 4N / 25mm to 20N / 25mm. When the adhesive strength of the weather-resistant adhesive layer is within the above range, the light control sheet of the present invention can be stably bonded to the adherend, and when the light control sheet is peeled off, the adhesion is performed. This is because it can be peeled off without causing glue residue on the body.
In addition, the said adhesive force is the value measured by 180 degree peeling method (peeling speed 300mm / min) about the sample (adherence body: blue plate glass, 3mm thickness) of 25mm width by the method based on JISZ0237. is there.

The method of forming the weather-resistant adhesive layer is not particularly limited as long as it can be formed with a desired thickness. For example, a coating solution obtained by dissolving the above-mentioned adhesive polymer material and an ultraviolet absorber exhibiting predetermined optical characteristics in a desired solvent. The method of applying to one surface of the light control layer and heating to cure the coating film can be used. Among them, it is preferable to perform an aging treatment after curing in order to promote crosslinking.
Examples of the coating method for applying the coating solution include a knife coater, an applicator coater, a die coater, a comma coater, a gravure coater, and a roll coater. Moreover, as an aging process, it is preferable to perform the heat processing for about 3 to 7 days at 40 degreeC, for example.

  The weather-resistant adhesive layer contains a UV absorber exhibiting predetermined optical characteristics, and thus can have high transparency without causing coloration due to the UV absorber. The transmittance of the weather-resistant adhesive layer in the visible light region is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. In addition, the said transmittance | permeability can be measured by JISK7361-1 (The test method of the total light transmittance of a plastic-transparent material).

2. Light Control Layer The light control layer in the present invention is one in which two or more regions that change the polarization state or phase state of transmitted light are formed in a fixed shape with a fixed interval.

  The region where the polarization state or phase state of transmitted light is changed is a region where only linearly polarized light in a specific vibration direction is transmitted among light incident on the dimming layer, or linearly polarized light incident on the dimming layer is delayed. A region in which the vibration direction is rotated in accordance with the direction of the axis or the phase difference and is converted into right circularly polarized light or left circularly polarized light.

Two or more regions that change the polarization state or phase state of the transmitted light are formed in a constant shape with a constant interval. In other words, since the two or more regions are continuously formed with a certain width and a certain shape, the two or more regions are arranged in a continuous pattern.
Examples of the shape of the region include a triangle, a square, a rectangle, a quadrangle such as a rhombus, a hexagon, and the like. Examples of the arrangement pattern of the region include a stripe shape and a staggered shape. Especially, it is preferable that the said area | region is rectangular stripe shape.
Further, as shown in FIG. 3A, for example, the arrangement pattern has the same shape and the same width D as the first region P1 and the first region P1, but is changed to a different polarization state or phase state. The two regions P2 can be an arrangement pattern formed alternately and continuously. At this time, the arrangement pattern of the plurality of first regions P1 is an arrangement pattern formed with a constant interval D corresponding to the width D of the second region located between the two first regions P1.
Moreover, although not shown in figure, it can be set as the arrangement | positioning pattern formed continuously so that three or more area | regions changed to a different polarization state or phase state may be repeatedly arrange | positioned.
Further, as shown in FIG. 3B, the plurality of regions P1 to P11 having the same shape and the same width D and having different polarization states or phase states are changed in a stepwise manner. It can be set as the arrangement pattern formed continuously. At this time, the center-to-center distance between one region and the other region adjacent to the one region has a constant distance D corresponding to the width D of the region.
3 indicate the direction of factors that change the polarization state or phase state, such as the direction of the polarization axis and the direction of the in-plane slow axis in the phase difference region.

  The width (interval) of each region in the light control layer is usually equidistant, and is not particularly limited as long as it is a size capable of changing the polarization state or phase state of transmitted light. Within the range of 5.0 cm, in particular, within the range of 0.8 cm to 3.0 cm, particularly within the range of 1.0 cm to 1.5 cm is preferable. When the width of the region is smaller than the above range, the joints of the respective regions increase, and the light shielding plate provided with the light control sheet of the present invention may deteriorate the shielding property, but is larger than the above range. In the light control plate provided with the light control sheet of the present invention, the slide width becomes large, and it is necessary to increase the size of the light incident surface of the light control plate, so that the product appearance or operability may be deteriorated. . Note that the width of the region refers to the length of the region in the short direction when the region is in a stripe shape. Other shapes can be defined by the length between the centers.

As the layer configuration of the light control layer, for example, an embodiment (first embodiment) having a pattern retardation layer and a polarizing plate disposed closer to the adhesive layer than the pattern retardation layer, the light is directly applied to the polarizing plate. Examples include a mode (second mode) in which a region for changing a polarization state (hereinafter sometimes referred to as a polarization region) is formed in a pattern.
Hereinafter, each aspect of the light control layer will be described.

(1) 1st aspect The light control layer of this aspect has a pattern phase difference layer and the polarizing plate arrange | positioned rather than the said pattern phase difference layer at the weather-resistant adhesion layer side. Among them, the pattern retardation layer has a transparent film substrate, an alignment layer formed on the transparent film substrate, and a retardation layer formed on the alignment layer. It is preferable that two or more retardation regions different in at least one of the in-plane slow axis direction and the phase difference are formed in a constant shape with a constant interval. Since the light control layer has such a configuration, the light control plate including the light control sheet of the present invention can be easily designed as a slide mechanism, and the operation of the light control plate is facilitated. It is.
The retardation region in the retardation layer corresponds to the above-described pattern region in the light control layer. Further, in the above-mentioned retardation layer, two or more retardation regions different in at least one of the in-plane slow axis direction and the phase difference are “formed in a certain shape with a certain interval”. This phase difference region is synonymous with “consecutively formed with a constant width and a constant shape”.

An example of a light control sheet provided with such a light control layer is demonstrated with reference to FIG. FIG. 4 is a schematic cross-sectional view showing another example of the light control sheet. The light control layer 2 of this aspect has the pattern phase difference layer 40 and the polarizing plate 50 arrange | positioned rather than the pattern phase difference layer 40 at the weather-resistant adhesion layer 1 side. The pattern retardation layer 40 is formed by laminating a transparent film substrate 33, an alignment layer 32, and a retardation layer 31 in at least this order, and the retardation layer 31 includes an in-plane slow axis direction and a retardation. Two or more phase difference regions Q1 and Q2 that are different from each other are continuously formed with a constant width D and a constant shape.
In addition, the aspect of the phase difference layer 31 in FIGS. 4A and 4B will be described later.

  The retardation layer in the pattern retardation layer may be one in which the orientation of each retardation region is fixed, and the pattern retardation layer may not include the alignment layer. The pattern retardation layer not including the alignment layer was obtained by, for example, separately forming a retardation layer fixed on the temporary substrate by photo-curing by regulating the alignment with the alignment layer and irradiating ultraviolet rays or the like. It is obtained by transferring the retardation layer to a transparent film substrate.

(A) Polarizing plate The polarizing plate in this aspect is arrange | positioned in the weather control adhesion layer side rather than a pattern phase difference layer in a light control layer.
The polarizing plate is not particularly limited as long as the transmitted light can be linearly polarized light. For example, a polarizing plate generally used in a liquid crystal display device can be used.

  Such a polarizing plate is not particularly limited as long as it contains at least a polarizer. For example, the polarizing plate is an embodiment comprising a polarizer and a polarizing plate protective film disposed on at least one surface of the polarizer. Alternatively, the polarizer may be laminated or fixed on the pattern retardation layer to form a polarizing plate.

  The polarizer is not particularly limited as long as the transmitted light can be linearly polarized light. Usually, the polarizer contains iodine. Specifically, there can be mentioned a polarizer in which a film made of polyvinyl alcohol is impregnated with iodine and uniaxially stretched to form a complex of polyvinyl alcohol and iodine.

  The direction of the polarization axis in the polarizing plate is not particularly limited, and can be appropriately selected according to the orientation of the retardation region in the pattern retardation layer described later.

  In addition, the polarizing plate protective film in the polarizing plate is not particularly limited as long as it can protect the polarizer and has a desired transparency, but particularly in the visible light region. Those having a transmittance of 80% or more are preferred, and those having a transmittance of 90% or more are more preferred. In addition, the said transmittance | permeability of a polarizing plate protective film can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

Examples of the material constituting the polarizing plate protective film include cellulose derivatives, cycloolefin resins, polymethyl methacrylate, polyvinyl alcohol, polyimide, polyarylate, polyethylene terephthalate, polysulfone, polyethersulfone, amorphous polyolefin, acrylic resin, Examples thereof include modified acrylic polymers, polystyrene, epoxy resins, polycarbonates and polyesters. Among these, it is preferable to use a cellulose derivative, a cycloolefin resin, or an acrylic resin as the resin material.
In addition, about the specific example of the cellulose derivative, cycloolefin type resin, and acrylic resin as a material of a polarizing plate protective film, the material of the polarizing plate protective film described in Unexamined-Japanese-Patent No. 2012-198522 is mentioned, for example. . Among these, triacetyl cellulose (TAC) which is a cellulose derivative is preferable. This is because TAC is widely used as a polarizing plate protective film, but is easily deteriorated by ultraviolet rays, so that the effect of the present invention by using the above-mentioned weather-resistant adhesive layer is more exhibited.

  The polarizing plate protective film may be subjected to a surface treatment. For example, when triacetyl cellulose (TAC), which is a cellulose derivative, is used as a material for a polarizing plate protective film, adhesion to a polarizer containing polyvinyl alcohol can be improved by saponifying the surface.

  The thickness of the polarizing plate protective film is not particularly limited as long as it has a desired light transmittance, but is usually within a range of 5 μm to 200 μm, particularly within a range of 15 μm to 150 μm, particularly within a range of 30 μm to 100 μm. Preferably there is.

The polarizing plate protective film is disposed on at least one surface of the polarizer, and among them, it is preferably disposed at least on the surface of the polarizer on the adhesive layer side.
Moreover, when the said polarizing plate protective film is arrange | positioned on both surfaces of the said polarizer, the polarizing plate protective film of the surface of the said polarizer may be the same, and may differ. Especially, it is preferable that the polarizing plate protective film arrange | positioned at the surface by the side of the contact bonding layer of a polarizer is a triacetyl cellulose (TAC). This is because the effect of the present invention by using the weather-resistant adhesive layer is more exhibited.

(B) Pattern retardation layer The said pattern retardation layer has a transparent film base material, the orientation layer formed on the said transparent film base material, and the retardation layer formed on the said orientation layer. is there.

(I) Retardation layer The retardation layer is formed on the alignment layer, and two or more retardation regions different in at least one of the in-plane slow axis direction and the phase difference have a constant shape with a constant interval. Is formed. That is, two or more phase difference regions are formed in a fixed shape with a fixed interval. The retardation of the retardation layer is fixed for each retardation region.

(Phase difference region)
The phase difference region is different in at least one of the direction of the in-plane slow axis and the phase difference.
About the width | variety etc. of a phase difference area | region, it can be made to be the same as that of the pattern area | region in the light control layer mentioned above.

(When the direction of the in-plane slow axis of the phase difference region is different)
In the retardation layer, the direction of the in-plane slow axis of the retardation region is different, for example, as illustrated in FIG. 4A, the retardation region showing the same in-plane retardation value is constant. It is formed continuously with a width and a constant shape, and means that the direction of one in-plane slow axis and the direction of the other in-plane slow axis of adjacent phase difference regions are orthogonal to each other. In FIG. 4A, the arrow direction in each of the retardation regions Q1, Q2 of the retardation layer 31 indicates the direction of the in-plane slow axis.

  When the in-plane slow axis direction is different, the in-plane retardation value (Re) of the retardation region can be appropriately set according to the material, pattern, etc. constituting the retardation layer, for example, 100 nm. It is preferable to be within a range of ˜160 nm, particularly within a range of 110 nm to 150 nm, and particularly within a range of 120 nm to 140 nm.

The in-plane retardation value is an index indicating the degree of birefringence in the in-plane direction of the refractive index anisotropic body, and the refractive index in the slow axis direction having the largest refractive index in the in-plane direction is represented by Nx, When the refractive index in the fast axis direction orthogonal to the slow axis direction is Ny, and the thickness in the direction perpendicular to the in-plane direction of the refractive index anisotropic body is d,
Re [nm] = (Nx−Ny) × d [nm]
It is a value represented by. The in-plane retardation value (Re value) can be measured by, for example, a parallel Nicol rotation method using KOBRA-WR manufactured by Oji Scientific Instruments. Moreover, the in-plane retardation value of a micro area | region can also be measured using a Mueller matrix by AxoScan made from AXOMETRICS (USA). In the present invention, the Re value means a value at a wavelength of 589 nm unless otherwise specified.

(When the phase difference in the phase difference area is different)
In the retardation layer, the phase difference in the retardation region is different. For example, as illustrated in FIG. 4B, the retardation region indicating the same in-plane slow axis direction has a constant width and a constant width. The phase difference value (in-plane retardation) corresponding to the film thickness difference is indicated by the difference in thickness for each phase difference region.
In the following description, a thick retardation region may be referred to as a thick film region, and a small retardation region may be referred to as a thin film region. The thick film region and the thin film region correspond to portions indicated by Q2 and Q1 in FIG.

When the phase difference of the retardation region is different, the thickness difference between the thick film region and the thin film region is appropriately determined according to the material of the retardation layer, the pattern of the retardation region, and the like.
In particular, when the thick film region and the thin film region are alternately striped as illustrated in FIG. 3A, the film thickness difference is the in-plane retardation value in the thick film region and the in-plane retardation in the thin film region. It is preferable that the difference from the retardation value is a distance corresponding to λ / 2 minutes. Thereby, the in-plane retardation value of the thin film region can be equivalent to λ / 4 minutes, and the in-plane retardation value of the thick film region can be equivalent to λ / 4 + λ / 2 minutes. This is because the linearly polarized light that passes through the phase difference region can be circularly polarized light that are orthogonal to each other.

  The thickness of the thick film region and the thin film region is not particularly limited as long as the difference between the thick film region and the thin film region is a predetermined range. For example, when the thickness of the thick film region is 3.0 μm and the thickness of the thin film region is 1.0 μm, the difference is 2.0 μm, but the thickness of the thick film region is 13.0 μm and the thickness of the thin film region is May be 11.0 μm, and the difference may be 2.0 μm. In particular, the thickness of the thick film region is preferably in the range of 1.6 μm to 20 μm, more preferably in the range of 2.5 μm to 10 μm, and particularly preferably in the range of 1.5 μm to 5 μm. The thickness of the thin film region is preferably in the range of 0.1 μm to 17 μm, more preferably in the range of 1 μm to 7 μm, and particularly preferably in the range of 1 μm to 4 μm.

(Retardation layer)
As a material for the retardation layer, a rod-like compound having refractive index anisotropy is preferable. This is because it can be regularly oriented and the retardation layer has a desired retardation. Among these, a liquid crystalline material exhibiting liquid crystallinity is preferable. This is because the liquid crystalline material has a large refractive index anisotropy, so that the retardation layer tends to have a desired retardation.

  As said liquid crystalline material, the material which shows liquid crystal phases, such as a nematic phase and a smectic phase, can be mentioned, for example. Among these, it is preferable to use a liquid crystalline material exhibiting a nematic phase. This is because a liquid crystalline material exhibiting a nematic phase is easily aligned regularly as compared with liquid crystalline materials exhibiting other liquid crystal phases.

  Further, as the liquid crystalline material exhibiting the nematic phase, a material having spacers at both ends of the mesogen is preferable. This is because a liquid crystalline material having spacers at both ends of the mesogen has excellent flexibility and high transparency.

Further, the rod-like compound is preferably one having a polymerizable functional group in the molecule, particularly one having a polymerizable functional group capable of three-dimensional crosslinking. This is because when the rod-shaped compound has a polymerizable functional group, the rod-shaped compound is polymerized and fixed, so that the retardation layer is excellent in alignment stability and hardly changes with time in retardation. When a rod-shaped compound having a polymerizable functional group is used, the retardation layer contains a rod-shaped compound crosslinked with a polymerizable functional group.
The “three-dimensional cross-linking” means that liquid crystal molecules are polymerized three-dimensionally to form a network (network) structure.

  Examples of the polymerizable functional group include polymerizable functional groups that are polymerized by irradiation with ionizing radiation such as ultraviolet rays and electron beams, or heating. Representative examples of these polymerizable functional groups include radical polymerizable functional groups and cationic polymerizable functional groups. About the said polymerizable functional group, it can be made to be the same as that of the polymerizable functional group in the rod-shaped compound shown by description, such as Unexamined-Japanese-Patent No. 2012-137725.

Furthermore, the rod-like compound is a liquid crystalline material exhibiting liquid crystallinity, and the one having the polymerizable functional group at the terminal is particularly preferable. This is because the rod-shaped compound is three-dimensionally polymerized in the retardation layer to have a network structure, and has orientation stability and excellent optical characteristics.
Even when a liquid crystalline material having a polymerizable functional group at one end is used, the alignment can be stabilized by crosslinking with other molecules.

In addition, as a specific example about the said rod-shaped compound, the compound described in Unexamined-Japanese-Patent No. 2012-137725 can be mentioned, for example.
Moreover, the said rod-shaped compound may use only 1 type, and may mix and use 2 or more types.

  About the thickness of the said phase difference layer, it can set suitably according to the kind of material, and the aspect of phase difference area | region.

(Ii) Orientation layer The orientation layer has a function of orienting the rod-shaped compound contained in the retardation layer when fixing the orientation state of the retardation region. In the alignment layer, two or more regions (alignment regions) are formed on the surface in a fixed shape with a fixed interval. That is, two or more alignment regions are continuously formed with a certain shape at a certain interval, and the retardation regions of the retardation layer are arranged at the same interval so as to correspond to the alignment region. , Allowing them to be arranged in shapes and patterns.

The material of the alignment layer is not particularly limited as long as the alignment region can be formed in a desired pattern in a desired shape. Examples of such a constituent material include a cured resin cured by irradiation with ionizing radiation such as heat or ultraviolet rays or electron beams. Examples of the curable resin include an ultraviolet curable resin, a thermosetting resin, and an electron beam curable resin. Among these, an ultraviolet curable resin is preferable.
Specific examples of the ultraviolet curable resin before curing the ultraviolet curable resin include, for example, a polymerizable oligomer or monomer having an acryloyl group such as urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, melamine acrylate, acrylic acid, Examples include acrylamide, acrylonitrile, styrene and other polymerizable oligomers or monomers having a polymerizable vinyl group, which are added alone or in combination with a photopolymerization initiator and optional additives.

  Each alignment region in the alignment layer has a corresponding relationship with each retardation region in the above-described retardation layer. The width of the alignment region can be the same as the width of the retardation region in the retardation layer.

The alignment region may have a fine uneven shape on the surface thereof. This is because, when forming the retardation region, the rod-shaped compound in the retardation layer provided on the alignment layer can be oriented in a certain direction due to the fine unevenness formed on the surface of each orientation region.
For example, in the retardation layer, when it is desired to change the direction of the in-plane slow axis for each retardation region, the orientation direction of the rod-shaped compound changes by changing the longitudinal direction of the fine concavo-convex shape for each corresponding orientation region. The direction of the in-plane slow axis can be changed for each phase difference region.
In addition, about the fine uneven | corrugated shape formed in the surface of an orientation area | region, it can be made to be the same as that of the fine uneven | corrugated shape of the surface of the orientation area | region described in Unexamined-Japanese-Patent No. 2012-137725, for example.

In addition, the orientation region may have a shape with a different thickness for each region. This is because when the alignment region has a different thickness for each region, the phase difference region corresponding to the alignment region also has a different thickness, and the phase difference can be changed for each phase difference region.
Furthermore, the alignment region may have a multi-stage shape.

  The thickness of the alignment layer is not particularly limited as long as a desired alignment regulating force can be expressed in the retardation layer, and is preferably within a range of 0.01 μm to 1.0 μm, for example.

(Iii) Transparent film substrate The material of the transparent film substrate is preferably a resin having high permeability. Specifically, acetyl cellulose resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, olefin resins such as polyethylene and polymethylpentene, acrylic resins, polyurethane resins, and polyether sulfone. , Polycarbonate, polysulfone, polyether, polyetherketone, (meth) acrylonitrile, cycloolefin polymer, cycloolefin copolymer, and other resins. Of these, acetyl cellulose resins, cycloolefin polymers, cycloolefin copolymers, and other resins, and acrylic resins are preferred because the in-plane retardation of the transparent film substrate tends to approach zero.

  The thickness of the transparent film substrate is not particularly limited as long as it can support a desired retardation region without impairing light transmittance, but is usually in the range of 20 μm to 188 μm, and in particular, in the range of 30 μm to 90 μm. It is preferable to be within.

  It is preferable that the transparent film substrate has a low retardation. This is because if the retardation of the transparent film substrate is large, the retardation of the retardation layer is affected and the light control function of the light control sheet of the present invention may be impaired. Specifically, the in-plane retardation value (Re value) of the transparent film substrate is preferably in the range of 0 nm to 10 nm, more preferably in the range of 0 nm to 5 nm, and particularly preferably in the range of 0 nm to 3 nm.

  Moreover, it is preferable that the said transparent film base material has high transparency, and it is preferable that the transmittance | permeability in visible region is 80% or more, especially 90% or more. In addition, the said transmittance | permeability in the visible light area | region of a transparent film base material can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

In addition, when the said orientation layer consists of ultraviolet curable resin, you may form the primer layer for improving the adhesiveness of a transparent film base material and ultraviolet curable resin on a transparent film base material.
The primer layer is not particularly limited as long as it has adhesiveness to both the transparent film substrate and the alignment layer, is visible optically transparent, and allows ultraviolet light to pass through. For example, a vinyl chloride-vinyl acetate copolymer system A layer made of a urethane-based resin material can be used.

(Iv) Others The pattern retardation layer has at least the transparent film substrate, the alignment layer, and the retardation layer, but may have other configurations as necessary.

  The thickness of the said pattern phase difference layer will not be specifically limited if the above-mentioned function is exhibited, It can set suitably according to a layer structure.

(2) Second Mode In the light control layer in this mode, two or more regions that change the polarization state of transmitted light are formed in a fixed shape with a fixed interval directly on the polarizing plate. That is, the two or more polarizing regions are continuously formed with a certain width and a certain shape.

In this aspect, having two or more regions that change the polarization state of transmitted light means having two or more regions having different polarization axis directions. Depending on the direction of the polarization axis, the light of one linearly polarized light component can be transmitted with high transmittance, and the light of the other linearly polarized light component that vibrates in the direction orthogonal to the one linearly polarized light component can be absorbed. Therefore, the polarizing plate in this embodiment does not need to be used in combination with the pattern retardation layer.
About the detail of a polarizing area | region, it can be made to be the same as that of the pattern area | region in the said light control layer.

  Further, other details of the polarizing plate in the present embodiment are the same as those of the polarizing plate described in the above-mentioned section “(1) First embodiment”, and thus the description thereof is omitted here.

3. Arbitrary member The light control sheet of this invention may have arbitrary members other than the above-mentioned member as needed.
Hereinafter, arbitrary members assumed in the light control sheet of the present invention will be described.

(1) Peeling layer It is preferable that the light control sheet of this invention has a peeling layer on a weather-resistant contact bonding layer. By having the release layer, it is possible to prevent adhesion of dust and the like to the weather-resistant adhesive layer until the light control sheet is bonded to the adherend, and to prevent the visibility of the light control sheet from being deteriorated due to dirt. . Moreover, it is because it can prevent that the surface of a weather-resistant contact bonding layer becomes rough and unwinding defect generate | occur | produces when unwinding the light control sheet wound up in roll shape.

  The material of the release layer is not particularly limited as long as it is generally used. Examples thereof include acrylic and methacrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl chloride resin, cellulose resin, silicon resin, chlorinated rubber, casein, various surfactants, and metal oxides. These materials may be used alone or in combination of two or more.

(2) Infrared reflecting layer or infrared absorbing layer The light control sheet of the present invention may have an infrared reflecting layer or an infrared absorbing layer. Regarding the reason for providing the infrared reflecting layer or the infrared absorbing layer, and the materials used for these layers, the reason for adding the infrared reflecting agent or infrared absorbing agent described in the above-mentioned section of “1. Weather-resistant adhesive layer”, Since these can be the same as the examples of these materials, description thereof is omitted here.
The arrangement position of the infrared reflection layer or the infrared absorption layer is not particularly limited, but it is usually preferable to arrange the infrared reflection layer or the infrared absorption layer on the weather-resistant adhesive layer side of the light control layer.
In addition, when providing an infrared reflective layer or an infrared absorption layer, an infrared reflective agent or an infrared absorber does not need to be contained in a weather-resistant contact bonding layer.
The thickness of the infrared reflecting layer or the infrared absorbing layer may be a thickness that does not impair the light transmittance of the light control sheet of the present invention and can exhibit the infrared reflecting function or the infrared absorbing function, for example, 0.1 μm. It is preferably in the range of 10 μm, particularly in the range of 0.1 μm to 5 μm.

(3) Others The light control sheet of the present invention may have a scratch-resistant layer, a self-cleaning layer, a light diffusion layer, an overcoat layer, a protective film, and the like as necessary.

4). Others The thickness of the light control sheet of the present invention is not particularly limited as long as it has a desired light transmission property. For example, the thickness is preferably in the range of 100 μm to 800 μm, and more preferably in the range of 200 μm to 400 μm. If the thickness of the light control sheet is larger than the above range, the light control sheet may be warped at the time of bonding. On the other hand, if the thickness is smaller than the above range, the light control sheet may be wrinkled at the time of bonding. There may be a problem such as entering.

  The transmittance in the visible light region of the light control sheet of the present invention is preferably 20% or more, and particularly preferably 30% or more. The transmittance in the visible light region can be measured according to JIS K7361-1 (a test method for the total light transmittance of plastic-transparent material).

  The light control sheet of the present invention only needs to be used in such a manner that the weather-resistant adhesive layer is disposed on the light incident side (light source side) of the light control layer. For example, a window glass for a building, a vehicle, etc. Used for bonding to interiors and furniture.

B. Light control plate Next, the light control plate of the present invention will be described. The light control board of this invention has the 1st light control part which has a 1st light control sheet, and the 2nd light control part which has a 2nd light control sheet, The said 1st light control part and the said 2nd light control part The light part is a light control plate arranged at an interval so that the first light control sheet and the second light control sheet face each other, wherein the first light control sheet and the second light control sheet Has at least an adhesive layer and a light control layer formed on the adhesive layer, and the light control layer has two or more regions that change the polarization state or phase state of transmitted light at regular intervals. The adhesive layer of at least one of the first light control sheet and the second light control sheet is formed of a certain shape and is a crosslink of an acrylic copolymer and a metal chelate crosslinker or an isocyanate crosslinker. Adhesive polymer that is cross-linked with an agent, and exhibits predetermined optical properties A weather-resistant adhesive layer containing an ultraviolet absorber, wherein at least one of the first dimming part and the second dimming part is movable in a plane direction intersecting with the region of the dimming layer. It is a feature.

The light control plate of this invention is demonstrated with reference to figures. 5A and 5B are a schematic side view and a top view of the light control plate of the present invention. FIG. 5 illustrates a mode in which the first light control unit and the second light control unit have a light control sheet and a transparent substrate.
The light control plate 30 of the present invention includes a first light control unit 20A having a first transparent substrate 11A and a first light control sheet 10A, and a second light control unit having a second transparent substrate 11B and a second light control sheet 10B. 20B is arranged with a desired interval W so that the first light control sheet 10A and the second light control sheet 10B face each other.
The first light control sheet 10A has at least the adhesive layer 3A and the light control layer 2A formed on the adhesive layer 3A, and is bonded to the first transparent substrate 11A via the adhesive layer 3A. Moreover, the 2nd light control sheet 10B has at least the light control layer 2B formed on the contact bonding layer 3B and the contact bonding layer 3B, and is bonded with the 2nd transparent substrate 11B through the contact bonding layer 3B. . The light control layers 2A and 2B can be the same as the light control layer 2 described in FIG.
In the example shown in FIG. 5, the adhesive layer 3 </ b> A of the first light control sheet 10 </ b> A is an adhesive polymer in which an acrylic copolymer and a metal chelate crosslinking agent or an isocyanate crosslinking agent are crosslinked. And a weather-resistant adhesive layer 1A containing an ultraviolet absorber exhibiting predetermined optical characteristics. That is, the first light control sheet 10A is the same as the light control sheet of FIG.
In the light control plate 30 of the present invention, the first light control unit 20A and the second light control unit 20B move at least one in a plane direction (lateral direction X) intersecting the pattern of the striped regions P1 and P2. Is possible. As a result, the polarization state or phase state of the transmitted light changes according to the correspondence between the pattern of the light control layer 2A in the first light control unit 20A and the pattern of the light control layer 2B in the second light control unit 20B. Switching between the state and the dark state can be performed instantaneously.
In addition, in the example shown in FIG. 5, the effect of this invention mentioned later can be show | played when the light L injects from the 1st light control part 20A side.

  According to the present invention, since the light control sheet in at least one of the first light control unit and the second light control unit is the one described in the above “A. Light control sheet”, the first light control unit and Among the second light control parts, the light control part having the light control sheet described in the section “A. Light control sheet” is disposed on the light incident side, thereby causing deterioration of the material constituting the light control layer. Wavelength light, particularly wavelength light that causes deterioration of iodine contained in the polarizing plate constituting the light control layer, is selectively and sufficiently absorbed in the ultraviolet absorbent that exhibits the optical characteristics in the weather-resistant adhesive layer first. be able to. Thereby, it is possible to suppress the deterioration of iodine that contributes most to the deterioration of the light control layer, and as a result, it is possible to suppress the light deterioration of the light control layer in each light control unit. Moreover, when a weather-resistant contact bonding layer has the above-mentioned composition, the light deterioration of the weather-resistant contact bonding layer itself can also be suppressed. For this reason, the light control board of this invention can be made into a thing with durability and high weather resistance.

The light control plate of the present invention has the above-described effects by arranging the light control unit having the light control sheet described in the section “A. Light control sheet” on the light incident side according to the application. It is.
For example, when the light control plate of the present invention is used as a window glass or the like at the boundary between indoor and outdoor, the light control unit having the light control sheet described in the section “A. Light control sheet” is disposed on the outdoor side. It is preferred that Outdoor light such as sunlight from the outside contains a lot of wavelength light that causes deterioration of the material constituting the light control layer, and in particular, ultraviolet light having a wavelength that causes deterioration of iodine contained in the polarizing plate constituting the light control layer. By making the light incident on the weather-resistant adhesive layer before the light-modulating layer of each light-modulating part, the light-resistant adhesive layer sufficiently absorbs the wavelength light and prevents the wavelength light from entering the light-modulating part. Because it can be done.
When the light control plate of the present invention is used in an environment where the incident direction of light is not specified in one direction with respect to the light control plate, such as when used as a partition indoors, the first light control unit and the second light control unit May have the light control sheet described in the section “A. Light control sheet”. Since both the first dimming part and the second dimming part have a weather-resistant adhesive layer, the weather-resistant adhesive layer can be used regardless of whether light enters from the first dimming part or the second dimming part. This is because it is possible to prevent deterioration of the light control section due to the above.

  Hereinafter, each structure of the light control board of this invention is demonstrated.

1. 1st light control part and 2nd light control part The 1st light control part in this invention has a 1st light control sheet at least. Moreover, the 2nd light control part in this invention has a 2nd light control sheet at least.

(1) 1st light control sheet and 2nd light control sheet The 1st light control sheet and 2nd light control sheet in this invention have an adhesive layer and the light control layer formed on the said adhesive layer at least. In the light control layer, two or more regions that change the polarization state or phase state of transmitted light are formed in a constant shape with a constant interval.
In the present invention, the adhesive layer of at least one of the first light control sheet and the second light control sheet is formed by crosslinking an acrylic copolymer and a metal chelate crosslinking agent or a crosslinking agent of an isocyanate crosslinking agent. A weather-resistant adhesive layer comprising an adhesive polymer and an ultraviolet absorber having predetermined optical properties.

In the first light control sheet and the second light control sheet, at least one of the adhesive layers may be a weather-resistant adhesive layer, and among them, both the first light control sheet and the second light control sheet have an adhesive layer. A weather-resistant adhesive layer is preferred. That is, it is preferable that both the first light control sheet and the second light control sheet are the light control sheets described in the section “A. Light control sheet”.
The effect of the present invention is exhibited when the weather-resistant adhesive layer is disposed on the light incident side of the light control layer, so that both the first light control sheet and the second light control sheet are weather resistant. This is because the effect of the present invention can be exhibited regardless of which of the first dimming portion and the second dimming portion is disposed on the light incident side by using the adhesive layer.
The weather-resistant adhesive layer is the same as that described in the section “1. Weather-resistant adhesive layer” described above, and a description thereof will be omitted here.

  Moreover, one adhesive layer of the said 1st light control sheet and the 2nd light control sheet has a composition different from the above-mentioned weather resistant adhesive layer (henceforth a non-weather resistant adhesive layer may be called). There may be. As the adhesive in the non-weather resistant adhesive layer, general adhesives such as acrylic adhesives, silicon adhesives, ester adhesives, urethane adhesives, and the like can be used. The non-weather resistant adhesive layer may include any material as necessary. Especially, it is preferable that an infrared reflective agent or an infrared reflective agent is included as arbitrary materials. The reason and the infrared reflective agent or the type of the infrared reflective agent are the same as those described in the above-mentioned section “A. Light control sheet”, and thus the description thereof is omitted here.

Other details of the light control layer in the first light control sheet and the second light control sheet can be the same as the contents described in the section “A. Light control sheet”, and thus description thereof is omitted here. To do.
In addition, the light control layer in a 1st light control sheet and a 2nd light control sheet normally has the same pattern area | region.

(2) Others The first light control part in the present invention may be any one having at least a first light control sheet, but the first light control sheet is provided on one surface of the first transparent substrate. It is preferable that Similarly, the second light control section in the present invention is preferably provided with the second light control sheet on one surface of the second transparent substrate. When each light control part is provided with a transparent substrate in addition to the light control sheet, it is possible to improve the mechanical strength of each light control part, for example, when the light control plate of the present invention is arranged in a wide area. Because.
In addition, a 1st transparent substrate is arrange | positioned on the surface facing the surface which faces a 2nd light control sheet among the surfaces of a 1st light control sheet. Moreover, a 2nd transparent substrate is arrange | positioned on the surface facing the surface facing a 1st light control sheet among the surfaces of a 2nd light control sheet.

  The constituent materials of the first transparent substrate and the second transparent substrate are not particularly limited as long as they can support the first light control sheet and the second light control sheet and have high light transmittance. And inorganic materials such as glass, polyester resins such as polyethylene terephthalate, acrylic resins, and resin materials such as polycarbonate.

  The first transparent substrate and the second transparent substrate preferably have high light transmittance, and the transmittance in the visible light region is preferably 80% or more, and particularly preferably 90% or more. In addition, the transmittance | permeability in the visible light area | region of a 1st transparent substrate and a 2nd transparent substrate can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

  The thicknesses of the first transparent substrate and the second transparent substrate are strong enough to hold the first light control sheet and the second light control sheet, and can exhibit the above light transmittance. For example, the thickness is preferably about 0.1 mm to 10 mm, and more preferably about 1.0 mm to 5 mm.

Moreover, it is good also as a 1st light control part and a 2nd light control part by itself, without bonding the 1st light control sheet and 2nd light control sheet in this invention to adherends, such as the above-mentioned transparent substrate.
In this case, a 1st light control sheet and a 2nd light control sheet shall have a protective film etc. on a weather-resistant contact bonding layer.

2. Others The light control plate of the present invention moves at least one of the first light control unit and the second light control unit in a plane direction intersecting the pattern region of the light control layer, and the pattern region in the first light control unit It is possible to change from the bright state to the dark state or vice versa by associating it with the pattern area in the dimmer unit. Here, “corresponding to the pattern region” means that the pattern of the region in the first dimming unit and the pattern of the region in the second dimming unit are overlapped with each other in plan view.
Further, the mode of the intermediate state when changing from the bright state to the dark state or vice versa can be changed according to the pattern of each light control layer. For example, when each light control layer of the first light control unit and the second light control unit has the stripe-shaped pattern region shown in FIG. 3A described above, the light control plate of the present invention has a bright state and a dark state. The state has an intermediate state that exists in stripes. On the other hand, when each light control layer of the 1st light control part and the 2nd light control part has the stripe-shaped pattern area | region shown in FIG.3 (b), the light control density | concentration of this invention is light-blocking density | concentration in steps. It has an intermediate state that changes.
Furthermore, a pattern, a picture, a character, etc. may be displayed according to the correspondence of the pattern area | region of each light control layer.
Note that “moving in the direction of the plane intersecting the region” means moving in a direction that intersects the pattern direction of the region and is parallel to the surface on which the region of the light control layer is formed. That is, it means moving in the surface direction in which the relative position of the pattern area of the first dimming unit and the pattern area of the second dimming unit changes. For example, if the pattern region is a stripe shape, it refers to a direction (X direction in FIG. 5) that intersects the long direction of the stripe and is parallel to the surface of the light control layer on which the pattern region is formed.

  In the light control plate of the present invention, as an interval between the first light control sheet and the second light control sheet, at least one of the first light control part and the second light control part can be moved in a desired direction, There are no particular limitations as long as the light control function can be exhibited. For example, it is preferable to be within a range of 0.01 mm to 5.0 mm, particularly within a range of 0.01 mm to 3.0 mm, and particularly within a range of 0.01 mm to 0.5 mm. If the distance between the first light control sheet and the second light control sheet is larger than the above range, deflection may occur when light is transmitted through the light control plate of the present invention. If it is small, the first light control sheet and the second light control sheet may contact and wear.

  The light control board of this invention may have arbitrary members as needed. Examples of the optional member include a scattering prevention film, a diffusion film, ground glass, an antireflection film, an antifouling layer, a housing, and a slide mechanism.

  The light control plate of the present invention can be used for architectural windows, ceiling windows, daylighting windows such as terraces, roofs and side walls of greenhouses, partitions, interiors, furniture, automobile sunroofs, and the like.

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

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Example 1]
A light control sheet was obtained by the following method.

(Formation of light control layer)
The light control layer was formed by the following method.
A copper plate having a size of 10 cm × 10 cm was prepared, polished in the left-right direction with an abrasive (Kaneyo ^TM manufactured by Kaneyo Soap Co., Ltd.), and washed. Thereafter, cutting was performed in a vertical direction with a diamond bit having an unevenness with a pitch of 200 nm produced by FIB processing so that the stripe spacing was 0.5 inch. After that, a UV curable resin (Unidic manufactured by DIC Corporation) is applied on the copper plate, and a TAC film (triacetylcellulose, Fujitac manufactured by Fuji Film) is placed on the copper plate as a transparent film base, and UV rays are applied. Irradiated to cure.
Next, the alignment layer was formed on the said TAC film base material by peeling a TAC film base material from a copper plate, and shaping uneven | corrugated shape on a TAC film base material. When the cross-sectional shape of the alignment layer was observed with an SEM, irregularities with a pitch of 200 nm and irregular irregularities were observed alternately.
Next, 5% by weight of a photopolymerization initiator (Irgacure 184 manufactured by BASF Corporation) was added to a solution of a liquid crystal (licrive (registered trademark) RMS03-013C (trade name) manufactured by Merck Co., Ltd.) material dissolved in a cyclohexanone solvent. The patterned solution is applied to the TAC film substrate on which the alignment layer is formed with a spin coater, dried at 80 ° C. for 10 minutes, and cured by irradiating with ultraviolet rays to form a pattern retardation film (pattern retardation layer). Was made. The prepared pattern retardation layer was bonded to a Sanritsu polarizing plate (HLC2-5618S) to obtain a light control layer.
In addition, although the abrasive | polishing agent was used for this rubbing, you may use the cloth for rubbing currently used for LCD manufacture.

(Formation of weather-resistant adhesive layer)
Benzotriazole-based UV absorber (100% by weight) based on an acrylic ester copolymer (product name: SK Dyne 1429DT, solid content 30%, manufactured by Soken Chemical Co., Ltd.) Product name: Tinuvin 928 (manufactured by BASF) 4 parts by mass (solid content 1.18 parts by mass) was stirred and dissolved with a stirrer at 50 rpm for 30 minutes. Further, 10 parts by mass (3 parts by mass in solid content) of an aluminum chelate crosslinking agent (product name: AD-5A, manufactured by Soken Chemical Co., Ltd.) was added as a crosslinking agent and stirred for 10 minutes to obtain a weather-resistant adhesive layer coating solution. It was.
Thereafter, the above weather-resistant adhesive layer coating solution is applied on one surface of the light control layer with an applicator so as to have a wet thickness of 83 μm, and dried at 80 ° C. for 2 minutes. A weather-resistant adhesive layer (thickness after drying: 25 μm) containing a triazole ultraviolet absorber was formed.

(Formation of light control sheet)
A light release separator film having a low silicon transferability (product name: P381031, thickness 38 μm, manufactured by Lintec Corporation) was laminated on the weatherproof adhesive layer, and aged at 40 ° C. for 5 days to obtain a light control sheet.

[Example 2]
A light control sheet was obtained in the same manner as in Example 1 except that the crosslinking agent in the weather-resistant adhesive layer coating solution was an isocyanate crosslinking agent (product name: L-45, manufactured by Soken Chemical Co., Ltd.).

[Example 3]
A light control sheet was obtained in the same manner as in Example 2 except that the ultraviolet absorber in the weather-resistant adhesive layer coating solution was a hydroxyphenyltriazine-based ultraviolet absorber (product name: Tinuvin 460, manufactured by BASF).

[Example 4]
A light control sheet was obtained in the same manner as in Example 2, except that the ultraviolet absorber in the weather-resistant adhesive layer coating solution was a benzotriazole ultraviolet absorber (product name: Tinuvin 1130, manufactured by BASF).

[Comparative Example 1]
A light control sheet was obtained in the same manner as in Example 2 except that the ultraviolet absorbent in the weather-resistant adhesive layer coating solution was a hydroxyphenyltriazine ultraviolet absorbent (product name: Tinuvin 479, manufactured by BASF).

[Comparative Example 2]
A light control sheet was obtained in the same manner as in Example 2 except that the ultraviolet absorber in the weather-resistant adhesive layer coating solution was a hydroxyphenyl triazine ultraviolet absorber (product name: Tinuvin 400, manufactured by BASF).

[Evaluation]
(Optical properties of UV absorber)
About the various ultraviolet absorbers used in Examples 1-4 and Comparative Examples 1-2, the light transmittance at a wavelength of 380 nm was measured.
In the measurement method, various ultraviolet absorbers are dispersed in toluene, a measurement solution having a concentration of 0.006% is prepared, the solution is injected into a glass cell having a width of 10 mm, and a spectrophotometer (Shimadzu Corporation UV-3150) is prepared. ) And a xenon lamp as a light source and measured by a double beam photometry method. The light transmittance at a wavelength of 380 nm with a toluene solvent alone was used as a reference.

(UV resistance test)
The light control sheets of the examples and comparative examples were bonded to glass (manufactured by Tokyo Special Glass) having a length of 100 mm, a width of 100 mm, and a thickness of 2.8 mm to prepare test pieces. Each test piece was subjected to a UV resistance test according to the following procedure, and an appearance evaluation and a holding power evaluation after the deterioration were performed.
The ultraviolet degradation resistance test is performed using the following super-accelerated ultraviolet degradation resistance tester (Iwasaki Electric Co., Ltd., trade name: iSuper UV tester, model number: SUV-W23), using the following (A), (B), 42 cycles were repeated with (C) as one cycle.
(A) In an atmosphere having a temperature of 63 ° C. and a humidity of 50% RH, ultraviolet rays having an illuminance of 60 mW / cm ² and a peak wavelength of 365 nm are irradiated from the glass side for 20 hours.
(B) Watering treatment by shower is performed for 30 seconds.
(C) Hold in an atmosphere of a temperature of 63 ° C. and a humidity of 98% RH for 4 hours without performing ultraviolet irradiation.

<Appearance evaluation>
A color difference measurement was performed on each test piece after the UV resistance test. The measurement was performed using a spectrophotometer (manufactured by Shimadzu Corporation, model number: UV-3100PC), and the ΔE ^* ab value was measured by a transmission method in accordance with JIS K7105. The ΔE ^* ab value is a color difference formula (ΔE ^* ab = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* )) according to the (L ^* , a ^* , b ^* ) space color system of the CIE 1976 standard. ² } ^1/2 ). A ΔE ^* ab value of less than 3 was marked with ◯, and a value of 3 or more was marked with ×. When the ΔE ^* ab value was less than 3, yellowing was not confirmed, indicating good weather resistance, and when the ΔE ^* ab value was 3 or more, yellowing at a level causing a practical problem was visually recognized.

<Retention force evaluation>
For each test piece after the UV degradation resistance test, Tensilon (product name: RTG-1205, manufactured by A & D Co., Ltd.) is used, and a head with a maximum weight capacity of 0.5 kN is used according to JIS A5759. The holding force was measured. A holding force of 4N or more was rated as “◯”, and a holding force of less than 4N was marked as “X”. The test piece having a holding force of less than 4N was lightly peeled by the UV resistance test.

  Table 1 shows the optical characteristics of the ultraviolet absorber used, and the results of appearance evaluation and holding power evaluation of the light control sheets of Examples and Comparative Examples.

From the result of Table 1, in Examples 1-4 using the ultraviolet absorber which shows a predetermined | prescribed optical characteristic, compared with Comparative Examples 1-2 using the ultraviolet absorber which does not show a predetermined | prescribed optical characteristic, ultraviolet-ray deterioration resistance The ΔE ^* ab value after the test was low and the holding power was good.
From the above results, it was shown that a light control sheet excellent in weather resistance and durability can be obtained by selecting an ultraviolet absorber.

DESCRIPTION OF SYMBOLS 1, 1A, 3A ... Weatherproof adhesive layer 2, 2A, 2B ... Light control layer 3B ... Adhesive layer 10 ... Light control sheet 10A ... 1st light control sheet 10B ... 2nd light control sheet 20A ... 1st light control part 20B ... 2nd light control part 30 ... Light control board 40 ... Pattern retardation layer 50 ... Polarizing plate

Claims (6)

A dimming layer in which two or more regions that change the polarization state or phase state of the transmitted light are formed in a constant shape at regular intervals;
A weather-resistant adhesive layer disposed on one surface of the light control layer,
The weather-resistant adhesive layer has an adhesive polymer obtained by crosslinking an acrylic copolymer and a metal chelate crosslinking agent or an isocyanate crosslinking agent, and a light transmittance of 60% or less at a wavelength of 380 nm. A light control sheet comprising an ultraviolet absorber.   The light control sheet according to claim 1, wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber. The light control layer has a pattern retardation layer and a polarizing plate disposed on the weather-resistant adhesive layer side than the pattern retardation layer,
The pattern retardation layer has a transparent film substrate, an alignment layer formed on the transparent film substrate, and a retardation layer formed on the alignment layer,
The phase difference layer is characterized in that two or more phase difference regions different in at least one of the direction of the in-plane slow axis and the phase difference are formed in a constant shape with a constant interval. The light control sheet | seat of the range 1st term | claim or 2nd term | claim. A first light control unit having a first light control sheet, and a second light control unit having a second light control sheet,
The first dimming unit and the second dimming unit are dimming plates arranged with an interval so that the first dimming sheet and the second dimming sheet face each other,
The first light control sheet and the second light control sheet have at least an adhesive layer and a light control layer formed on the adhesive layer,
In the light control layer, two or more regions that change the polarization state or phase state of transmitted light are formed in a constant shape with a constant interval,
An adhesive polymer in which the adhesive layer of at least one of the first light control sheet and the second light control sheet is cross-linked with an acrylic copolymer and a cross-linking agent of a metal chelate cross-linking agent or an isocyanate cross-linking agent; And a weather-resistant adhesive layer containing an ultraviolet absorber having a light transmittance of 60% or less at a wavelength of 380 nm,
At least one of said 1st light control part and said 2nd light control part is movable to the surface direction which cross | intersects the said area | region which the said light control layer has, The light control board characterized by the above-mentioned. The first light control part is provided with the first light control sheet on one surface of the first transparent substrate,
The said 2nd light control part is a thing with which the said 2nd light control sheet | seat was provided on one surface of the 2nd transparent substrate, The light control board of Claim 4 characterized by the above-mentioned. The light control layer has a polarizing plate disposed on the adhesive layer side of the pattern retardation layer and the pattern retardation layer,
The pattern retardation layer has a transparent film substrate, an alignment layer formed on the transparent film substrate, and a retardation layer formed on the alignment layer,
The phase difference layer is characterized in that two or more phase difference regions different in at least one of the direction of the in-plane slow axis and the phase difference are formed in a constant shape with a constant interval. The light control board of the range 4th term | claim or 5th term | claim.

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