JPH0439623A - Patterned dimming material and production thereof - Google Patents

Abstract

PURPOSE:To prevent white turbid regions from clearing and from obscure patterns by providing a liquid crystal layer formed by dispersing a liquid crystal into a resin matrix of a curing type resin formed by compounding a specific compd. and a radical trapping agent. CONSTITUTION:The liquid crystal layer 1 is formed by uniformly dispersing the liquid crystal into the resin matrix of the curing type resin formed by compounding the liquid crystal restraining compd. expressed by formula I (X is SH, NH2, OH; R1 is H, CH3; R2 is an alkyl group, alkyl group contg. a hetero bond; R3 is H, C, alkyl group, alkyl group contg. a hetero bond; n is 1 to 4 integer) and the radical trapping agent and curing the mixture. The liquid crystal layer 1 has transparent regions 4a to 4b and white turbid regions 40 while the voltage is not impressed between transparent electrodes 2a and 2b. Since the activated radical trapping agent is incorporated into the liquid crystal layer of the white turbid regions, the white turbid regions are prevented from clearing with lapse of time and the distinct patterns having the large contrast between the transparent regions and the white turbid regions are maintained over a long period of time.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention utilizes the characteristics of liquid crystals to create differences in optical properties, thereby making it possible to use them in various applications such as displays, signboards, blinds, daylighting materials, domes, and partitions. This invention relates to a patterned light control material suitable for use in light control applications, and a method for producing the same.

[Conventional technology]

As a light control material that utilizes the characteristics of liquid crystals, ■ Nematic liquid crystals are emulsified and dispersed in an aqueous polyvinyl alcohol solution, encapsulated, coated on a transparent electrode material, dried, and then placed on the coating film. Another transparent electrode material that serves as an electrode is glued together. ■ By mixing liquid crystal into a photocurable resin such as acrylic resin, sealing it between two transparent electrode materials and irradiating it with light. (1) A liquid crystal is dispersed in an epoxy resin, and the liquid crystal is sealed between two transparent electrode materials and then thermally cured.

When a voltage is applied between the transparent electrodes of these light control materials, the liquid crystal layer changes from a cloudy light-scattering state to a transparent light-transmitting state, and thus is expected to be used in the various light control applications described above.

However, the transparent electrode material of the above-mentioned light control material is obtained by vapor-depositing a metal oxide such as IT○ or a metal such as gold, silver, copper, aluminum, or palladium on a transparent base material such as a transparent plastic film, or by depositing a transparent conductive paint. A transparent electrode is formed on one side of the transparent base material by coating it, so when a voltage is applied between the transparent electrodes, the entire liquid crystal layer changes from a cloudy state to a transparent state, causing patterns etc. to appear. I couldn't make it disappear.

Therefore, the present inventors have already proposed a light control material in which one of the transparent electrodes laminated on both sides of the liquid crystal layer is patterned into a desired pattern or design by means such as etching (Japanese Patent Application No. 1983-
No. 164530). In this light control material, when no voltage is applied between the transparent electrodes, the entire liquid crystal layer becomes cloudy like in conventional light control materials, but when a voltage is applied, the liquid crystal layer changes to the pattern shape of one transparent electrode. It becomes transparent in almost the same shape as
Since the other parts remain cloudy, a transparent watermark pattern appears, allowing for a wide variety of light control.

Furthermore, in Japanese Patent Application Laid-Open No. 63-301922, when manufacturing a light control material by sealing a photocurable resin mixed with liquid crystal between two transparent electrodes and curing the resin by irradiation with light, the transparent electrode It is described that when a portion of the material is irradiated with light while a voltage is applied therebetween, the irradiated portion is cured while remaining transparent.

[Problem to be solved by the invention]

However, when patterning a transparent electrode by etching as in Japanese Patent Application No. 63-164530, a photoresist film is first formed on the surface of the transparent electrode, and a mask plate with a pattern formed thereon is superposed. However, since the photoresist film must be exposed to light to open a window according to the pattern shape, then immersed in an etching solution, and the photoresist film must be removed after etching, it is time consuming and costly. In addition, a light control material with patterned transparent electrodes will not produce a transparent watermark pattern unless a voltage is applied between the transparent electrodes, and the entire liquid crystal layer will remain transparent no matter how much voltage is applied. Therefore, there was a problem in that it was unsuitable for light control applications that prioritize light transmission over light scattering.

On the other hand, when forming a transparent pattern using the method of JP-A No. 63-301922, the liquid crystal layer of the light control material is uncured before irradiation with light, so handling such as setting the mask plate is difficult. There is a problem that the liquid crystal flows, causing unevenness, and that the light control material cannot be cut into the desired shape if the liquid crystal layer is not hardened before pattern formation. there were.

The present invention has been made in view of the above circumstances, and its purpose is to develop a clear and even pattern consisting of transparent areas and cloudy areas when no voltage is applied, and to make the entire pattern transparent when a voltage is applied. The pattern disappears and light can pass through well, and the cloudy area does not become transparent over time and the pattern becomes unclear. Furthermore, the applied voltage can be relatively low, which improves safety and It is an object of the present invention to provide a patterned light control material that is excellent in economy, is easy to manufacture, and can be cut into a desired shape before forming a pattern, and a method for manufacturing the same.

[Means to solve the problem]

In order to achieve the above object, the patterned light control material of the present invention has the following formula: R3 (X-CHz-CH-C-0-RJ-v-R3 (in the formula
is SH, NHz, OH,, R++ [1, CH3, R2
is an alkyl group, an alkyl group containing a hetero bond, R3 is H
, C, an alkyl group, an alkyl group containing a hetero bond, n is an integer of 1 to 4) and a radical scavenger, and the liquid crystal is dispersed in the resin matrix of a curable resin. The present invention is a light control material comprising a liquid crystal layer consisting of a liquid crystal layer and transparent electrodes laminated on both sides of the liquid crystal layer, and is characterized in that the liquid crystal layer has a transparent region and a cloudy region in a state where no voltage is applied.

The first manufacturing method of the present invention for manufacturing this patterned light control material is a liquid crystal in a resin matrix of a curable resin that is made by blending the compound represented by the above formula with a radical scavenger and curing it. A light control material is prepared that includes a liquid crystal layer in which a liquid crystal layer is dispersed, and transparent electrodes are laminated on both sides of the light control material, and a voltage is applied between the transparent electrodes of the light control material to emit light while keeping the liquid crystal layer transparent. After partially irradiating the light modulating material, the light is irradiated to at least a non-light-irradiated portion of the light modulating material without applying a voltage between the transparent electrodes, and the second manufacturing method is characterized in that: , a light control material is produced in the same manner as in the first manufacturing method, and after partially irradiating the light control material with light without applying a voltage between the transparent electrodes of the light control material, a voltage is applied between the transparent electrodes. This is characterized in that the light is irradiated onto at least a non-light-irradiated portion of the light control material.

Note that the "pattern" in the patterned light control material of the present invention is a broad term that includes patterns, designs, characters, symbols, etc. formed by transparent areas and cloudy areas.

[For production]

The above formula: R (X-CHg-CH-C-0-R2)ii-L (in the formula
is SH, NHz, OH, R+ is If, C) I,, R2
is an alkyl group, an alkyl group containing a hetero bond, R1 is H
, C, an alkyl group, an alkyl group containing a hetero bond, n is an integer of 1 to 4) (hereinafter referred to as a liquid crystal restraining compound) and a radical scavenger. A liquid crystal layer in which liquid crystal is dispersed in a resin matrix is in a state where the liquid crystal molecules in the liquid crystal layer can freely change their orientation before pattern formation.

Therefore, when a voltage is applied between the transparent electrodes on both sides of the liquid crystal layer to apply an electric field, the liquid crystal molecules align in the direction of the electric field and become transparent, and when no voltage is applied, the orientation of the liquid crystal molecules becomes random, scattering transmitted light. and becomes cloudy.

However, when a voltage is applied between the transparent electrodes of the light control material to partially irradiate light while keeping the liquid crystal layer transparent as in the first manufacturing method (the manufacturing method for H term (2)), the light irradiation is The liquid crystal molecules in the part are restrained (fixed) in the direction of the electric field, resulting in a transparent Fyi region that does not return to a cloudy state even if no voltage is applied, and the part that is not irradiated with light becomes a cloudy region that becomes cloudy again with no voltage applied. becomes.

The reason why only the light-irradiated portion of the liquid crystal layer becomes a transparent region is presumed to be due to the following reason.

That is, in the resin matrix of the liquid crystal layer that is cured by blending a liquid crystal restraining compound and a radical scavenger, CtLz=CR+C0OR( R is H, alkyl group,
It is thought that an acrylic acid compound (vinyl compound) represented by an alkyl group containing a hetero bond is included. Therefore, if a voltage is applied to orient the liquid crystal molecules in the direction of the electric field and a portion of the liquid crystal layer is irradiated with light while keeping it transparent, the light will pass through the resin matrix or the liquid crystal dispersed in the form of droplets in the irradiated area. , radicalizes the acrylic acid compounds present in the resin matrix and liquid crystal, and the acrylic acid compounds present near the interface with the liquid crystal, and this radicalized acrylic acid compound, especially those present in the liquid crystal and near the interface with the liquid crystal. When acrylic acid compounds react with each other or with reactive residues (epoxy groups, catalysts, etc.) present in the resin matrix or liquid crystal to generate unknown macromolecular compounds, they become entangled with liquid crystal molecules. is restrained (immobilized) while remaining oriented in the direction of the electric field. The light-irradiated portion of the liquid crystal layer also contains a radical scavenger, but since the commercially available radical scavenger used in the present invention is activated at a slower rate than the acrylic acid compound by transmitted light, this initial partial irradiation is At this stage, the radical scavenger hardly acts, and therefore, as described above, the acrylic acid compound reacts preferentially, restrains the liquid crystal molecules, and forms a transparent region.

On the other hand, in the non-irradiated areas of the liquid crystal layer, the acrylic acid compound does not turn into radicals and the liquid crystal molecules are not restrained, so when no voltage is applied, the orientation of the liquid crystal molecules becomes random and the area becomes cloudy again. .

After forming a transparent region and a cloudy region by first partial irradiation, when light is irradiated to at least the non-light-irradiated portion (cloudy region) of the light modulating material without applying a voltage, in the liquid crystal layer in the cloudy region, Since light is reflected at the interface between the resin matrix and liquid crystal and scattered within the resin matrix, the scattered light radicalizes the acrylic acid compound in the resin matrix, and simultaneously activates the radical scavenger in the resin matrix. Therefore, the radicalized acrylic acid compound reacts with the radicalized radical scavenger, and the acrylic acid compounds do not react with each other to produce a polymer. In this way, in the cloudy region, the liquid crystal is dispersed in an almost unrestricted state, and the activated radical scavenger is present in the resin matrix. The patterned light control material of the present invention manufactured by the first manufacturing method as described above has a transparent region in which the liquid crystal molecules in the liquid crystal layer are restrained in an oriented state in the direction of the electric field, and a transparent region in which the liquid crystal molecules are restrained in a state in which they are not restrained. It has a cloudy region where the radical scavenger is activated, and when a driving voltage is applied between the transparent electrodes, the liquid crystal molecules in the cloudy region align in the direction of the electric field and become transparent, so the entire liquid crystal layer becomes transparent. When the pattern disappears and no voltage is applied, only the liquid crystal molecules in the cloudy region become randomly oriented and return to the cloudy state, resulting in a clear pattern consisting of a cloudy region and a transparent region.

In addition, as in the second manufacturing method (the manufacturing method of claim (3)), when light is partially irradiated on the dimming material that is cloudy as a whole with no voltage applied, the light irradiated portion is The radical scavenger contained in the liquid crystal layer is activated, and the liquid crystal molecules remain almost unrestricted. Next, when a voltage is applied to make the entire liquid crystal layer transparent and light is irradiated to at least the non-light-irradiated part of the light control material, the liquid crystal molecules in the liquid crystal layer in that part change in the direction of the electric field based on the same principle as described above. Since it is restrained in the oriented state, a transparent region that does not become cloudy again is formed. On the other hand, the part where the radical scavenger is activated by irradiation with light for the first time, of course, if the radical scavenger is not irradiated with light the second time.
Even when light is irradiated, the activated radical scavenger described above captures the radicals of the acrylic acid compound generated by light irradiation and prevents the reaction, so that the liquid crystal molecules are hardly restrained. Therefore, when no voltage is applied to this part, it becomes a cloudy region that becomes cloudy again.

In the patterned light control material of the present invention obtained by such a second production method, the cloudy region and the transparent region are in an increased positional relationship with the patterned light control material obtained by the first production method, When a voltage is applied between the transparent electrodes, the entire surface becomes transparent, and when the voltage is removed, a pattern in which the cloudy areas and transparent areas are reversed appears.

The patterned light control material of the present invention obtained by the above-mentioned first and second manufacturing methods contains an activated radical scavenger in the liquid crystal layer in the cloudy region, so that the cloudy region changes over time. It does not become transparent over time, and maintains a clear pattern with a large contrast between transparent areas and cloudy areas over a long period of time. That is, an activated radical scavenger is included,
If not, if you make the entire light control material transparent by applying a voltage under natural light, the unreacted acrylic acid compound in the liquid crystal will be radicalized by the natural light, which will react and become liquid crystal molecules aligned in the direction of the electric field. They become entangled little by little, gradually restraining the liquid crystal molecules and making them transparent. However, when an activated radical scavenger is included as in the present invention, it captures the radicals of the acrylic acid compound generated by exposure to natural light and prevents the binding of liquid crystal molecules, resulting in a cloudy region over time. It does not become transparent and can produce a clear pattern for a long period of time even when no voltage is applied.

By the way, another way to prevent the cloudy region from becoming transparent over time is to create a light control material with a liquid crystal layer that does not contain a radical scavenger, and to control the light while keeping the entire liquid crystal layer transparent by applying a voltage. After partially irradiating the light material to form a transparent region in which liquid crystal molecules are oriented and restrained in the direction of the electric field and a cloudy region in which liquid crystal molecules are not restrained, at least the cloudy region of the light control material is irradiated with no voltage applied. It is conceivable to irradiate light to cause the acrylic acid compound near the interface between the liquid crystal and the resin matrix to react, thereby restraining the liquid crystal molecules in the cloudy region in a random state.

In this way, when no voltage is applied, the liquid crystal molecules in the cloudy region return to a randomly restrained state, thereby preventing transparentization over time. However, if the liquid crystal molecules in the cloudy region are randomly restrained, the cloudy region cannot be made transparent unless a high enough voltage is applied to overcome the restraining force and orient the liquid crystal molecules in the direction of the electric field, resulting in increased power consumption. It becomes uneconomical. In this regard, in the patterned light control material of the present invention, the activated radical scavenger present in the cloudy region captures the radicals of the acrylic acid compound and prevents it from becoming transparent over time. Since the liquid crystal molecules in the cloudy region are not restrained in a random direction and are in a free state, they are easily aligned in the direction of the electric field with a low applied voltage and become transparent. Therefore, since there is no need to apply a high voltage, power consumption can be reduced and it is economical.

〔Example〕

Hereinafter, the patterned light control material of the present invention and its manufacturing method will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing the patterned light control material of the present invention, and FIG. 2 is an enlarged sectional view taken along line A-B-C-D in FIG. 1.

The patterned light control material shown in FIG. 1 and FIG. ) is a sheet-like light control material having a five-layer structure with a thickness of about 100 to 500 μm, in which the transparent electrode is stacked on the liquid crystal layer side, and the liquid crystal layer 1 is in a state where no voltage is applied. It has transparent regions 4a, 4b, 4c and a cloudy region 40. Collecting electrode portions 5a and 5b are formed on one side edge (right side edge) of one (upper) transparent electrode 2a and the other side edge (left side edge) of the other (lower side) transparent electrode 2b, respectively. The collector electrode parts 5a and 5b are covered with an insulating tape 7. Furthermore, terminal pieces 6a and 6b that protrude to the outside are attached to one ends of the collector electrode parts 5a and 5b, so that lead wires can be connected to these terminal pieces 6a and 6b. R.

The above liquid crystal layer 1 has the formula (X-CHz-CH-C-0-R
z″FF-R3 (in the formula, × is SH, NHz, OH, R-
yoH, cH, R2 is an alkyl group, an alkyl group containing a hetero bond, R3 is HlC, an alkyl group, an alkyl group containing a hetero bond, n is an integer from 1 to 4). Liquid crystals are uniformly dispersed in the resin matrix of a curable resin that is cured by blending a compound and a radical scavenger. A liquid crystal layer in which nematic liquid crystal is dispersed in the form of droplets in a resin matrix of epoxy resin by a phase separation method is suitable. In this liquid crystal layer 1, the liquid crystal dispersed in the form of droplets has a substantially uniform particle size of about 1 μm, and the liquid crystal molecules have good orientation when a voltage is applied, so the entire liquid crystal layer 1 can be made transparent by applying a voltage. This is because high transparency can be obtained.

As the above-mentioned curable resin, in addition to the above-mentioned thermosetting epoxy resin, thermosetting resins such as acrylic resins and urethane resins are used, and liquid crystals, curing agents, catalysts, microbeads, etc. are mixed therein. . The epoxy resin is preferably an aliphatic epoxy resin, and an aromatic epoxy resin may be mixed therewith as appropriate. These thermosetting resins include photocurable resins, such as acrylate monomers and oligomers such as N-butyl acrylate and trimethylolpropane triacrylate, and urethane acrylates such as carbonate urethane acrylate, polyether urethane acrylate, and polyol urethane acrylate. Monomers and oligomers may be added as appropriate.

As the curing agent for forming these epoxy resins into a matrix, various epoxy resin curing agents such as amine type, acid anhydride type, mercaptan type, etc. can be used.

Moreover, there are various kinds of liquid crystal restraining compounds mentioned above, and these compounds are used alone or in combination of two or more kinds to be blended into thermosetting resins such as epoxy resins. Specifically, X is S)I, Ro is 1). R
2 is CH2, R3 is an alkyl group containing an oxygen bond, n is 3
is trimethylolpropane tris-(β-thiopropionate), X is SR, R, is H1R2 is CH,,R
, is an alkyl group, and n is 3, such as trimethylpropane tris-(β-thiopropionate). Further, a compound in which X is NH2 or SH is desirable because it can also be used as a curing agent for epoxy resin. It is presumed that, as described above, a portion of this compound cleaves during thermosetting to produce an acrylic acid compound, which is polymerized by light irradiation and restrains (fixes) the liquid crystal molecules.

On the other hand, radical scavengers are compounded to capture the radicals of acrylic acid compounds produced by the cleavage of liquid crystal restraining compounds, as mentioned above, such as hindered amine type and hindered phenol which are commercially available A radical scavenger such as a type of radical scavenger is preferably used. The amount of the radical scavenger varies depending on the type thereof, the amount of the liquid crystal restraining compound, etc., but the preferred range is about 0.1 to 5% by weight. When the amount is less than this, the radical scavenging effect becomes insufficient and it becomes difficult to sufficiently prevent the cloudy region from becoming transparent over time.On the other hand, even if the amount is more than the above range, the radical scavenging effect hardly changes. Since there is no, it is wasted.

The amount of liquid crystal to be added may be appropriately determined in consideration of economical efficiency and degree of cloudiness, but for boat fishing, it is appropriate to add about 20 to 70% by weight.

In the transparent regions 4a, 4b, and 4c of the liquid crystal layer 1, the liquid crystal molecules are restrained in a state aligned in the direction of the electric field by the reaction of the acrylic acid compound generated by the cleavage of the liquid crystal restraining compound, as described in detail in the operation section. This is a region in which the cloud does not become cloudy again even if no voltage is applied. On the other hand, the cloudy region 40 is a region where liquid crystal molecules are not restrained,
When no voltage is applied between the transparent electrodes 2a and 2b, the direction of the liquid crystal molecules is random and the area becomes cloudy, but when a voltage is applied, the liquid crystal molecules are oriented in the direction of the electric field due to the force of the electric field, and the area becomes transparent. . In the resin matrix of the liquid crystal layer 1, the radical scavenger activated by light irradiation is uniformly dispersed and contained.

The transparent electrode films 3a and 3b are made of a transparent resin film such as polyethylene terephthalate, polyether sulfone, or polycarbonate, and a metal oxide such as ITO or tin oxide, or a metal such as gold, silver, copper, aluminum, or palladium on one side of the film. The transparent electrode 2 is formed by vapor deposition or sputtering, or by applying a transparent conductive paint.
A and 2b are formed on the entire surface of one side.

A collecting electrode part 5a provided at the edge of the transparent electrodes 2a, 2b,
5b is for making the voltage almost uniform between the transparent electrodes 2a and 2b, and the collecting electrode part 5a on the right edge connects the right edge of the liquid crystal layer 1 and the right edge of the lower transparent electrode film 3b. Cut it out to expose the right edge of the upper transparent electrode 2a in a band shape,
By applying a conductive paste such as copper paste, silver paste, carbon paste, etc. to the exposed part, it is formed so as not to short-circuit with the lower transparent electrode 2b, and the collector electrode part 5b on the left side is formed on the liquid crystal layer. 1 and the left side edge of the upper transparent electrode film 3a to expose the lower transparent electrode 2b in a band shape, and by applying the above-mentioned conductive paste to the exposed portion, the upper transparent electrode 2a is removed. It is designed to prevent short circuits. Note that the collector electrodes 5a, 5b may be formed by pasting a metal foil tape such as a copper foil tape with a conductive adhesive on the exposed portions of the transparent electrodes 2a, 2b.

A terminal piece 6a attached to one end of the collector electrode portions 5a and 5b,
The terminal piece 6b is made of a metal foil tape such as a copper foil tape, or a thin piece of metal such as phosphor bronze, copper, or aluminum, and is bonded with a conductive adhesive or the like, and the terminal pieces 6a,
A lead wire is connected to the protruding portion of 6b.

Further, an insulating tape 7 covering the collector electrode parts 5a and 5b
This prevents moisture infiltration, electrical leakage, electric shock, and peeling of the periphery of the light control material, and uses, for example, adhesive insulating tape made of polypropylene resin, polyvinyl chloride resin, polyethylene terephthalate resin, or fluororesin. Incidentally, instead of the insulating tape 7, a transparent insulating adhesive such as an epoxy resin or silicone resin adhesive may be applied and covered.

The patterned light control material having the above structure includes transparent electrodes 2a,
When no AC voltage is applied between 2b, transparent regions 4a, 4b, 4c in which liquid crystal molecules are oriented and restrained in the direction of the electric field.
It has a cloudy region 40 in which the orientation of liquid crystal molecules is random, and these transparent regions 4a, 4b, 4c and the cloudy region 40
A pattern with good contrast is created.

This pattern is created by the restriction of the liquid crystal molecules in the transparent areas 4a and 4.
Since the outlines of b and 4c are clearly visible, they are extremely sharp, and even minute patterns cannot be measured.

The transparent electrode 2a of the light control material in which a pattern is expressed in this way,
When an AC voltage is applied between 2b and an electric field is applied to the liquid crystal layer 1, the unrestrained liquid crystal molecules in the cloudy region 40 are oriented in the direction of the electric field, and the normal optical refractive index of the liquid crystal and the optical refractive index of the resin matrix are the same or Approximately, it changes from a cloudy state to a transparent state,
The entire liquid crystal layer 1 becomes transparent and the pattern disappears. and,
When the state is returned to the state where no voltage is applied, the transparent regions 4a, 4. In contrast, in the cloudy region 40, the direction of the liquid crystal molecules becomes random, and the transmitted light is scattered due to the difference between the extraordinary light refractive index of the liquid crystal and the refractive index of the resin matrix, resulting in a cloudy state. As it returns, the vivid pattern appears again.

The patterned light control material of the present invention has the transparent region 4a as described above.
, 4b, 4c and the cloudy area 40 can be created or disappeared to achieve a wide variety of light control.In addition, when a voltage is applied, light passes through the entire surface, and when no voltage is applied, the light is transmitted through the entire surface. Since light also passes through the transparent regions 4a, 4b, and 4c, it is suitable for dimming applications where priority is given to light transmission. Furthermore, since the liquid crystal molecules in the cloudy region 40 are not restrained and are easily oriented by the force of a relatively weak electric field, it can be made transparent simply by applying a low AC voltage of about 40 to 50 V. Therefore, it is economical because even if it remains transparent for a long time, the power consumption is small. In addition, when the patterned light control material of the present invention is used in a place that receives light such as sunlight, cloudy areas 4
The acrylic acid compound present in 0 receives light and becomes radical, but the generated radicals are captured by the activated radical scavenger in the cloudy region 40, so that the liquid crystal molecules are restrained in the direction of the electric field. It disappears. Therefore, cloudy area 4
0 is sufficiently prevented from becoming transparent over time, a clear pattern with good contrast between the transparent regions 4a, 4b, 4C and the cloudy region 40 can be developed over a long period of time when no voltage is applied.

Next, referring to FIG. 3, the first manufacturing method of the present invention (
The manufacturing method according to claim (2) will be explained.

According to the first manufacturing method, transparent electrode films 3a and 3b are first placed on both upper and lower surfaces of a sheet-like light control material having a five-layer structure as shown in FIG. A sheet-like light control material having a structure in which the light control material is laminated so as to face the liquid crystal layer is produced. As the resin liquid for forming the liquid crystal layer 1, for example, the above-mentioned liquid crystal restraining compound and radical scavenger are blended with uncured epoxy resin, and appropriate amounts of nematic liquid crystal, the above-mentioned curing agent, catalyst, microbeads, etc. are mixed. are preferably used. The sheet-like light control material is produced by sandwiching this resin liquid in a thin layer between transparent electrode films 3a and 3b and heating and curing it. When the epoxy resin is cured by heating, the liquid crystal gradually becomes insoluble and undergoes phase separation as the cross-linking and curing of the epoxy resin progresses, and when the curing is completed, the liquid crystal becomes approximately spherical with a uniform particle size of about 1 μm. Since it is uniformly dispersed in the form of droplets, a light control material having a liquid crystal layer 1 with high transparency when voltage is applied can be obtained.

At the same time, the liquid crystal restraining compound contained in the epoxy resin is cleaved by some action, and acrylic acid compounds (vinyl compounds) represented by CH2.CR and C00R are generated. However, the radical scavenger contained in the epoxy resin is not activated at this point. The sheet-like light control material produced in this way can be freely cut into a desired shape because the liquid crystal layer 1 is hardened.

In the next collector electrode forming step, the fabricated sheet-like light control material is removed by cutting off one side edge (right side edge) of the lower transparent electrode film 3b, as shown in FIG. 3 (b). At the same time, peel off the liquid crystal layer and remove the other (upper) transparent electrode film 3.
The transparent electrode 2a of a is exposed in a strip shape, and a conductive paste is applied to the exposed part of the electrode as shown in FIG.
A is formed, and a terminal piece 6a is adhered to the collector electrode portion 5a using a conductive adhesive or the like. Then, in the same way, as shown in FIG.
The liquid crystal layer is peeled off by cutting off the left side edge), the collector electrode part 5b is formed on the exposed part of the transparent electrode film 2b, and the terminal piece 6b is adhered.

After forming the collector electrodes 5a and 5b and attaching the terminal pieces 6a and 6b, connect the lead wires to both terminal pieces 6a and 6b of the light control material as shown in the same figure (e), and connect the upper and lower transparent Electrode 2
An AC voltage is applied between a and 2b to change the liquid crystal H1 from a cloudy state to a transparent state, and in this state, a mask plate 10 with a cutout pattern 9 formed thereon is placed on one side of the light control material, and light is emitted from the light source 1). is partially irradiated through the mask plate 10. In this way, when a portion of the liquid crystal layer 1 is irradiated with light while the entire liquid crystal layer 1 is made transparent, the light passes through the resin matrix and the liquid crystal dispersed in the form of droplets in the irradiated portion of the liquid crystal layer 1, and enters the resin matrix and liquid crystal. Not only the existing acrylic acid compounds but also the acrylic acid compounds existing near the interface with the liquid crystal are radicalized. At this time, the radical scavenger contained in the light irradiated area is also radicalized (activated) by the light irradiation, but this radical scavenger has a slower activation rate than the acrylic acid compound, so it reacts with the radicals of the acrylic acid compound. cannot be captured before. Therefore, this radicalized acrylic acid compound, especially the radicalized acrylic acid compound near the interface with the liquid crystal, reacts with each other or with reactive residues present in the resin matrix or liquid crystal, resulting in polymer molecules. When creating an unknown compound, it becomes entangled with liquid crystal molecules,
Since the liquid crystal molecules are restrained in an oriented state in the direction of the electric field by this entanglement, a transparent region 4 that is always transparent is formed in the liquid crystal layer 1, as shown in FIG. On the other hand, in the part of the liquid crystal layer 1 that is not irradiated with light, the acrylic acid compound does not turn into radicals and the liquid crystal molecules are not restrained, so when no voltage is applied, the orientation of the liquid crystal molecules becomes random, and as shown in the figure (f). As shown, a cloudy region 40 becomes cloudy again.

The voltage applied between the transparent electrodes 2a and 2b may be equal to or higher than the voltage at which the liquid crystal layer 1 becomes transparent, and the light irradiation conditions should be such that a sufficient amount of light is applied to make the liquid crystal layer 1 transparent. Any irradiation conditions that allow for this may be used. However, harsh irradiation conditions such that light penetrates into the masked portion of the liquid crystal layer 1 should be avoided. Further, as the light source 1), an ultraviolet irradiation lamp such as a mercury lamp, a xenon lamp, a simulated sunlight, or the like is used.

After the first partial irradiation is completed, a second light irradiation is performed with no voltage applied, as shown in FIG. 3(G)D. This second light irradiation may be performed on the entire surface of the light modulating material as in the illustrated embodiment, or it may be performed only on the part (cloudy part 40) that was not irradiated with light in the first partial irradiation. In other words, it is sufficient that at least the first non-light-irradiated portion is irradiated with light. When the first non-irradiated area (cloudy area 40) is irradiated with light, the light is reflected at the interface between the resin matrix and the liquid crystal and scattered within the resin matrix.This scattered light causes the acrylic in the resin matrix to The acid compound becomes a radical, and at the same time the radical scavenger is also activated.

Therefore, the radicalized acrylic acid compound reacts with the radicalized radical scavenger, and the acrylic acid compounds do not react with each other to produce a polymer. When this second light irradiation is completed, activated radical scavengers become scattered within the resin matrix.

The patterned light control material in which the transparent area 4 and the cloudy area 40 are formed as described above is made into a final product by covering the collecting electrode parts 5a and 5b on the side edges of the image with an insulating tape 7, as shown in FIG. Become.

Next, referring to FIG. 4, the second manufacturing method (i
The manufacturing method for the range (3) for f is explained.

In this second manufacturing method, a light control material is created and the terminal pieces 6a, 6 are
The process up to the step of attaching b is the same as the first manufacturing method described above, but the pattern formation method thereafter is different. That is, as shown in FIG. 4 (A), the mask plate 10 is placed on one side of the light control material, and the light control material is partially irradiated with light from the light source 1) without applying a voltage, and then as shown in FIG. 4 (B). As shown, a voltage is applied and light is irradiated from the light source 1) while keeping the light control material transparent. This second light irradiation may be performed on the entire surface of the light control material as shown in FIG. In short, it is sufficient to irradiate at least the first non-irradiated portion with light.

As mentioned above, when the entire light control material is initially in a cloudy state without applying any voltage and is partially irradiated with light, the radical scavenger contained in the liquid crystal layer in the light irradiated area is activated, and the liquid crystal molecules are similar to those described above. Maintains a state that is almost unrestricted based on the principle of

Therefore, when a voltage is applied between the transparent electrodes 2a and 2b of this light control material, the entire liquid crystal layer 1 becomes transparent as shown in FIG. 4(b). When the second light irradiation was performed with the entire surface made transparent by applying a voltage, the liquid crystal molecules in the parts that were not irradiated with light in the first partial irradiation were oriented in the direction of the electric field using the same principle as above. Figure 4 (
As shown in c), a transparent region 4 is formed that does not become cloudy again even if no voltage is applied. However, since the part that is first irradiated with light contains an activated radical scavenger in the resin matrix, even if the acrylic acid compound becomes a radical due to the second light irradiation, it is immediately captured by the radical scavenger. Therefore, in the first light irradiation area, the liquid crystal molecules are hardly restrained, so that when no voltage is applied, a cloudy region 40 becomes cloudy again as shown in FIG. 4(c).

Therefore, according to this second manufacturing method, a patterned light control material is obtained in which the transparent region 4 and the cloudy region 40 have an arrangement relationship opposite to that in the first manufacturing method. Similar to the patterned light control material described above, this patterned light control material also has a clear pattern consisting of the transparent region 4 and the cloudy region 40, and the entire pattern can be made transparent without applying a high voltage. This is economical because the cloudy region 40 does not become transparent over time, and a clear pattern with good contrast can be produced for a long period of time without any voltage being applied.

In all of the above embodiments, the pattern is formed after the collector electrode parts 5a, 5b are formed and the terminal pieces 6a, 6b are attached, but the pattern may be formed first. Further, in all of the above embodiments, the collector electrode parts 5a and 5b are covered with the insulating tape 7 after the pattern is formed, but the collecting electrode parts 5a and 5b may be covered with the insulating tape 7 before the pattern is formed.

Furthermore, in all of the above examples, light was irradiated in a cloudy state or a transparent state, but in addition to this, if a voltage lower than the voltage that makes the transparent state is applied to make the part semi-turbid and light is irradiated to the unirradiated part, Depending on the number of volts of voltage, the liquid crystal is restrained and fixed in various semi-turbid states, making it possible to create multi-tiered patterns. Instead of the above-mentioned voltage, it is also possible to create a multi-stage pattern by controlling the amount of light.

As above, the patterned light control material of the present invention and the manufacturing method thereof have been described in detail with reference to examples, but the present invention is not limited thereto. Transparent plastic plates and glass plates such as acrylic resin plates, polycarbonate resin plates, polystyrene resin plates, and vinyl chloride resin plates can be bonded using adhesives or adhesives such as epoxy, acrylic, vinyl acetate, silicone, and urethane. It can be pasted by means such as room temperature curing, heat curing, ultraviolet irradiation curing, etc., or it can be pasted using hot melt sheets, butyral sheets, etc., and it can also be pasted using heat ray-cutting films, ultraviolet-cutting films, weather-resistant films, etc. It is also possible to add various functions by laminating improved films and the like.

(Example) YH300 manufactured by Tobu Kasei was used as the epoxy resin, trimethylolpropane tris-(β-thiopropionate) represented by the structural formula % as the curing agent, 1,8-diazabicyclo(5,4 ,0) undec-7-ene, BDH as liquid crystal
Company 1) E8 (epoxy resin) vs. (curing agent + catalyst) vs.
Liquid crystal) were weighed so that the weight ratio was 1:0.7:1.2, and then dimethyl succinate, which was on the radical scavenging side,
1-(2-hydroxyethyl)-4-hydroxy-2,
A small amount of 2,6,6-titramethylbiveridine polycondensate and crosslinked follistyrene microbeads (particle size 20 μm) were added and mixed uniformly, and the mixture was placed between ITO films and heated at 70°C in an oven. A light control material was obtained by heating and curing for a period of time.

When a collector electrode is formed on the obtained light control material, a lead wire is tied to it, and a voltage of 30 to 40 V is applied, the light control material becomes transparent.
When the voltage application was stopped, the condition returned to a cloudy state. A masking material with a cutout pattern formed on one side of this light control material was placed over the light control material, and light from simulated sunlight was irradiated for 10 minutes while a voltage of 30V was applied to the light control material. As a result, even after the application of voltage was stopped, the areas irradiated with light did not return to a cloudy state and remained transparent, and a clear pattern of cloudy areas and transparent areas appeared.

This patterned light control material was irradiated with light from a high-pressure mercury lamp for 5 minutes without applying any voltage to cause the photoreactive substance in the cloudy part to react and stabilize.

When a voltage of 60 V or more was applied to the thus obtained patterned light control material, the entire surface became transparent, and when the voltage application was stopped, a pattern appeared. In addition, when this patterned light control material was exposed to sunlight inside an east-facing window while a voltage of 60V was applied, a clear pattern appeared even after 6 months when the voltage application was stopped, impairing its function. Never happened.

〔Effect of the invention〕

As is clear from the above description, the patterned light control material of the present invention is capable of performing a wide variety of light control by creating or disappearing a clear pattern with good contrast consisting of transparent areas and cloudy areas. Moreover, when no voltage is applied, light passes through the transparent region, and when a voltage is applied, light passes through the entire surface, making it suitable for light control applications where priority is given to light transmission. In addition, the entire structure can be made transparent without applying high voltage, so
It is economical because it consumes less power even if it is used transparent for a long time. Furthermore, since the cloudy region does not become transparent over time, a clear pattern with good contrast between the transparent region and the cloudy region can be produced over a long period of time when no voltage is applied. In addition, in terms of manufacturing, it is extremely easy to form patterns, so compared to the conventional etching process of patterning transparent electrodes, it is possible to significantly reduce the effort and cost. It has excellent effects such as being able to be cut into desired shapes and being convenient to handle.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the patterned light control material of the present invention, Fig. 2 is an enlarged sectional view taken along line A-B-C-D in Fig. 1, and Fig. 3 (A). -(G) are cross-sectional views explaining one embodiment of the first manufacturing method of the present invention in the order of steps, and FIGS. It is sectional drawing which shows the first tip partial irradiation process in an example, the second light irradiation process, and the manufactured patterned light control material. 1... Liquid crystal layer, 2a, 2b... Transparent electrode, 3a, 3b... Transparent electrode film, 4.4a, 4b, 4cm... Transparent area, 40... Cloudy area.

Claims (3)

[Claims] (1) Formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, X is SH, NH_2, OH, R_1 is H, CH_
3. R_2 is an alkyl group, an alkyl group containing a hetero bond, R_3 is H, C, an alkyl group, an alkyl group containing a hetero bond, n is an integer from 1 to 4) and a radical scavenger are combined. A light control material comprising a liquid crystal layer formed by dispersing liquid crystal in a resin matrix of a curable resin that is cured by heating, and transparent electrodes laminated on both sides of the liquid crystal layer, the liquid crystal layer being in a state where no voltage is applied. A patterned light control material characterized by having a transparent area and a cloudy area. (2) A liquid crystal layer in which liquid crystal is dispersed in a resin matrix of a curable resin that is cured by blending the compound represented by the formula of claim (1) with a radical scavenger, and a transparent electrode laminated on the screen thereof. A voltage is applied between the transparent electrodes of the light control material to partially irradiate the light control material with the liquid crystal layer being transparent, and then a voltage is applied between the transparent electrodes. A method for producing a patterned light control material, which comprises irradiating at least a non-light-irradiated portion of the light control material with light without applying any light. (3) A liquid crystal layer formed by dispersing liquid crystal in a resin matrix of a curable resin that is cured by blending the compound represented by the formula of claim (1) with a radical scavenger, and a transparent electrode laminated on the screen thereof. After producing a light control material comprising: and partially irradiating light to the light control material without applying a voltage between the transparent electrodes of the light control material, applying a voltage between the transparent electrodes to control the light. A method for producing a patterned light control material, which comprises irradiating at least a non-irradiated portion of the light material.