KR101424185B1 - The method of a PDLC type light control body used light with long wavelength, the PDLC type light control body - Google Patents

Abstract

The present invention relates to a method of manufacturing a PDLC type light modulator using a long wavelength light and a PDLC type light modulator, and a method of manufacturing a PDLC type light modulator using a long wavelength light according to the present invention is a method of manufacturing a liquid crystal dispersion composition for manufacturing a PDLC type light modulator A step of forming a liquid crystal dispersion composition for preparing a light adjuster between two transparent base plates on which a transparent electrode layer is formed and a step of forming a liquid crystal dispersion composition for forming the light adjuster in a wavelength band ranging from 380 to 460 nm The PDLC type light modulating body according to the present invention includes two transparent substrate plates formed with transparent electrodes and a light modulating layer formed between two transparent substrate plates, The light-modulating layer is characterized in that the pendulum hardness measured after removing the transparent base plate on one side of the two transparent base plates is 30 s or more.

PDLC type light modulators, photoinitiators, dyes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PDLC type light modulator using a long wavelength light and a PDLC type light modulator,

The present invention relates to a method for producing a PDLC type light adjuster using a long wavelength light and a PDLC type light adjuster manufactured therefrom.

The PDLC (Polymer Dispered Liquid Crystal) type light modulator forms fine liquid crystal droplets in a matrix of a polymer material and reacts with a voltage applied from the outside. When the voltage is applied, the PDLC is aligned along the direction of the electric field applied to the liquid crystal, And the liquid crystal is irregularly arranged in a state in which no voltage is applied, so that light is scattered because the liquid crystal is not arranged according to the traveling direction of the light passing through the light adjuster. That is, a PDLC (Polymer Dispersed Liquid Crystal) type light modulator can be driven in two states, that is, a state in which light is transmitted and a state in which light is scattered, depending on whether a voltage is applied or not.

Unlike other liquid crystal displays using a nematic liquid crystal display, such a PDLC type light modulator has good brightness without using a polarizing plate and a rubbing process for aligning liquid crystals is omitted, so that the manufacturing process is simple, and a device such as a window shielding film Can be widely applied, and can be applied to a display device having a large area.

In general, a PDLC (Polymer Dispersed Liquid Crystal) type light adjuster is formed by forming a liquid crystal dispersion composition containing a liquid crystal, a dye, an oligomer, a monomer, and a photoinitiator between two transparent substrate plates having a transparent electrode layer formed thereon, When the ultraviolet rays are irradiated to the liquid crystal dispersion composition layer for the preparation of the light adjuster formed on the substrate, oligomer, monomer or the like is photo-cured by the photoinitiator contained in the composition to form a polymer material matrix, Crystal droplets are formed.

At this time, the photoinitiator contained in the liquid crystal dispersion composition has a maximum absorption peak near the wavelength of 300 nm, and the absorption is insignificant when the peak is mostly near 380 nm. Therefore, when the liquid crystal dispersion composition is photo- Light having a wavelength band (eg, light having a wavelength of 365 nm) is irradiated to advance the photo-curing reaction. However, most of the dyes contained in the liquid crystal dispersion composition exhibit a large absorption peak at a short wavelength band of less than 380 nm, and the dye absorbs a large amount of light to be absorbed by the photoinitiator, resulting in a relatively incomplete photo-curing reaction. When the photo-curing reaction is incompletely performed, the phase separation between the polymer matrix and the liquid crystal droplets becomes insufficient after the photo-curing reaction, and when the voltage is not applied to the PDLC type light modulator, There is a problem that the relative ratio of the applied voltage to the applied voltage is lowered. When the polymer matrix is incompletely cured, the adhesion to the transparent substrate is low. In addition, when light of a short wavelength band of less than 380 nm is irradiated to be photo-cured, the dye is broken by the light of a short wavelength band, and color difference becomes large.

The present invention improves the scattering effect of light when the voltage is not applied to the PDLC type light adjuster, increases the haze, increases the relative contrast ratio between when the voltage is applied and when no voltage is applied, A method of manufacturing a PDLC type light adjuster using the long wavelength light in which the adhesion to the base plate can be improved and the dye is less broken due to the light to be irradiated and the color difference is low, and a PDLC type light adjuster.

The method for producing a PDLC type light modulator using a long wavelength light according to the present invention comprises the steps of: preparing a liquid crystal dispersion composition for producing a PDLC type light adjuster; and forming a liquid crystal dispersion composition for preparing a light adjuster between two transparent plate substrates having a transparent electrode layer And a step of irradiating the liquid crystal dispersion composition layer for forming the light modulator formed between the two transparent base plates with light having a wavelength in the range of 380 to 460 nm to photo-cure the liquid crystal dispersion composition layer. Here, it is more preferable that the light irradiated in the photo-curing step is irradiated from a light emitting diode (LED) light source. In particular, it is most preferable that the light irradiated from the LED (light emitting diode) light source has a wavelength of 395 nm or 405 nm.

It is to be noted that the liquid crystal dispersion composition prepared in the step of producing the liquid crystal dispersion composition for PDLC type light adjuster includes liquid crystal, dye, oligomer, monomer and photoinitiator, and the photoinitiator has an absorption peak in the wavelength range of 380 to 460 nm desirable. Preferred examples of the photoinitiator satisfying these conditions include diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide (MAPO) (DAROCUR TPO, manufactured by Ciba Specialty Chemicals), phenylbis (2,4,6-trimethyl Benzoyl) -phosphine oxide (BAPO) (Irgacure 819 available from Ciba Specialty Chemicals), bis (etha 5-2,4-cyclopentadien-1-yl) bis [2,6- difluoro-3- 1-yl) phenyl] titanium (Metallocene, IRGACURE 784, manufactured by Ciba Specialty Chemicals).

A PDLC type light adjuster according to the present invention includes two transparent plate plates on which transparent electrodes are formed and a light control layer formed between two transparent plate plates, and the light control layer is formed by removing a transparent plate on one side of two transparent plate plates And the pendulum hardness measured after 30 seconds or more. It is preferable that the PDLC type light adjuster is manufactured by the PDLC type light adjuster manufacturing method using the long wavelength light according to the present invention.

The present invention improves the scattering effect of light when the voltage is not applied to the PDLC type light adjuster, increases the haze, increases the relative contrast ratio between when the voltage is applied and when the voltage is applied, A method of manufacturing a PDLC type light modulator using a long wavelength light which can improve the adhesion with a base plate and the dye is less likely to be broken due to the light to be irradiated and a PDLC type light modulator manufactured therefrom Respectively.

The method for producing a PDLC type light modulator using a long wavelength light according to the present invention comprises the steps of: preparing a liquid crystal dispersion composition for producing a PDLC type light adjuster; and forming a liquid crystal dispersion composition for preparing a light adjuster between two transparent plate substrates having a transparent electrode layer And a step of irradiating the liquid crystal dispersion composition layer for forming the light modulator formed between the two transparent base plates with light having a wavelength in the range of 380 to 460 nm to photo-cure the liquid crystal dispersion composition layer.

That is, as shown in the graph of FIG. 1, red (azo dye, Sigma-Aldrich product, Sudan Red), Blue (anthraquinone dye (Sudan Black, manufactured by Sigma-Aldrich) absorbs a large amount of light in the wavelength region of visible light in the visible region in the visible light region, but before that, Lt; RTI ID = 0.0 > absorbed < / RTI > Therefore, when the wavelength band causing the radical formation reaction of the photoinitiator overlaps with the wavelength band of the large absorption peak region existing in the short wavelength band of such a dye, the photoinitiator absorbs the large absorption peak existing in the short wavelength band of the ultraviolet region of the dye A large amount of light loss occurs. As a result, the radical-forming reaction of the photoinitiator becomes insufficient, and the photo-curing reaction of oligomers and monomers contained in the liquid crystal dispersion composition becomes insufficient. In general, light having a wavelength in the range of 380 to 460 nm is irradiated as a long wavelength band in a region where a large absorption peak of a short wavelength band in the ultraviolet region of the dyes used in the PDLC-type light- By curing the light, the degree of curing of the matrix of the polymer material can be improved. In addition, when light is cured by irradiation with light having a wavelength of less than 380 nm, the dye contained in the liquid crystal dispersion composition tends to be broken to a large extent, resulting in a large chrominance of the final prepared light adjuster. If it is more than 460 nm, a curing reaction due to a radical forming reaction may occur in ordinary ordinary light, and it is 460 nm or less, which makes it easier to manage the liquid crystal dispersion composition during manufacture and storage.

In this case, it is more preferable that the light is irradiated from a light emitting diode (LED) light source. In particular, it is most preferable that the light irradiated from a light emitting diode (LED) source has a wavelength of 395 nm or 405 nm.

The liquid crystal dispersion composition for the production of the PDLC type light adjuster used in the present invention contains a liquid crystal, a dye, an oligomer, a monomer and a photoinitiator, and the photoinitiator has a radical formation reaction in a long wavelength band region longer than the wavelength range of the maximum absorption peak in the ultraviolet region of the dye It is preferable that an absorption peak is formed in the wavelength band region in the range of 380 to 460 nm.

That is, when a conventional dye is a photoinitiator which does not have a large absorption peak of a short wavelength band in the ultraviolet ray region, or which can perform a radical formation reaction even in the presence of a large wavelength region of 380 to 460 nm, for example, (Irgacure 819, manufactured by Ciba Specialty Chemicals) in the wavelength range of 380 to 460 nm, the radical-forming reaction is possible even in this region. Therefore, when a composition containing such a photoinitiator is prepared and light having a wavelength in the range of 380 to 460 nm is irradiated when the photochromic material is prepared using this composition, the photo-curing reaction of the polymer matrix of the PDLC type light- It can be done better.

Preferable examples of the photoinitiator satisfying these conditions include diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide (MAPO photoinitiator), phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide (BAPO (Metallocene-based photoinitiator), bis (2,2-difluoro-3- (1H-pyrrol-1-yl) phenyl] , And the like. That is, in the long wavelength vs. photoinitiator, the absorption curve for each wavelength band of Irgacure 819 shows the maximum absorption peak at a wavelength of about 300 nm as shown in Fig. 2, and thereafter shows an absorption peak at a wavelength band of about 380 to 460 nm The radical formation reaction may well occur.

The liquid crystals, dyes, oligomers, monomers, etc. contained in the liquid crystal dispersion composition for producing the PDLC type light adjuster of the present invention can be selected from conventional liquid crystal dispersion compositions for use in the conventional PDLC type light adjuster.

Typically, the liquid crystal used in the liquid crystal dispersion composition for producing a PDLC type light adjuster is 4-n-propyl-4'-cyanobiphenyl, 4-n-butyl- 4-n-octyloxy-4'-cyanobiphenyl, 4-trans-propylcyclohexylcyanobenzene, 4-trans-butylcyclohexyl Trans-pentylcyclohexylcyanobenzene, 4-trans-hexylcyclohexylcyanobenzene, 4-trans-heptylcyclohexylcyanobenzene, 4-cyanoheptyl-4'-trans- Butyl cyclohexyl carboxylate, 4-cyanoheptyl-4'-trans-pentyl cyclohexyl carboxylate, 4-cyanophenyl-t-butyl benzoate, 4-naphthyl-4'-cyano-p-terphenyl, 4-cyano-4'-trans-pentylcyclohexane biphenyl, 4-cyano-phenyl-4'- trans- pentylcyclohexylbenzoate , 4-trans-propylcyclohexyl 4'-ethylbiphenyl, 4'-ethylbiphenyl, 4-trans-pentylcyclohexyl-4'-ethylbiphenyl, 4- methoxymethylphenyl- 4- (trans- Trans-phenyl-4'-trans-pentylcyclohexylbenzoate, 4-ethoxyphenyl-4'-trans-pentylcyclohexylbenzoate and 4-fluoro-phenyl- Can be selected and combined.

The dye may be one or more kinds selected from azo dyes, anthraquinone dyes, phenylene dyes, melocyanine dyes, azomethine dyes, phthalo perylene dyes, indigo dyes, azulene dyes, dioxazine dyes and polythiophene dyes Can be selected and combined. At this time, the dye may be a combination of two or more dyes depending on the color intended to be expressed in the light adjuster, or may be included alone. Specifically, those described in [Dichroic Dyes for Liquid Crystal Display] (A.V. Ivashchenko, CRC Co., 1994) can be mentioned.

Azo dyes, anthraquinone dyes and perylene dyes are preferable, and azo dyes and anthraquinone dyes are particularly preferable. The azo dye is preferably a monoazo dye, a bisazo dye, a trisazo dye, a monoazo dye, a bisazo dye, or a trisazo dye, preferably a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye or a pentakisazo dye. The azo dye usually includes a ring structure, and examples of the ring structure include a carbon ring (benzene ring, naphthalene ring and the like) and a heterocyclic ring (a quinoline ring, a pyridine ring, a thiazole ring, a benzothiazole ring, A benzooxazole ring, an imidazole ring, a benzimidazole ring, a pyrimidine ring, etc.). The anthraquinone dye preferably contains an oxygen atom, a sulfur atom or a nitrogen atom as a substituent, and it preferably contains, for example, alkoxy, aryloxy, alkylthio, arylthio, alkylamino or arylamino group. The substitution number of the substituent may be any number, and di-, tri- or tetrakis-substitution is preferable, and di- or tri-substitution is particularly preferable. The substitution position of the substituent may be any position, but is preferably 1,4-position di-substituted, 1,5-position di-substituted, 1,4,5-position tri-substituted, 1,2,5-position tri-substituted, 1,2,4,5-tetra-substituted, 1,2,5,6-tetra-substituted structure.

As the composition for forming the polymer material matrix, the oligomer may be selected from the group consisting of an achiral 3-mercaptopropionate, an alkyl thiocate, an alkyl thiol, a urethane oligomer having at least one allyl group, a urethane acrylate oligomer, a fliester acrylate oligomer, Epoxy acrylate oligomers may be used alone or in combination of two or more. The monomers can be used in combination in monofunctional or multifunctional acrylate monomers and vinyl ether monomers. For example, it is possible to use acrylic acid esters such as hydroxyethyl acrylate (HEA), hydroxyethyl methacrylate (HEMA), 1,6-hexanediol acrylate (HDDA), tripropylene glycol diacrylate (TPGDA) and trimethylolpropane triacryl (TMPTA), butanediol monovinyl ether, 1,4-cyclohexanedimethanol monovinyl ether, and triethylene glycol divinyl ether may be used alone or in combination of two or more.

Here, as an additive, an antioxidant, an ultraviolet absorber, a surfactant, a defoaming agent and the like may be further included if necessary.

The PDLC type light adjuster according to the present invention includes two transparent plate plates on which transparent electrodes are formed and a light control layer formed between the two transparent plate plates and having liquid crystal droplets dispersed in the polymer matrix and the matrix of the polymer matrix And the shading layer is characterized in that the pendulum hardness measured after removing the transparent base plate on one side of the two transparent base plates is 30 s or more. That is, the degree of curing of the matrix of the polymer material increases to such an extent that the pendulum hardness of the light-modulating layer becomes 30 s or more, and when the voltage is not applied relative to the conventional light modulator, the haze is high, The relative control ratio is high when the polymer matrix is not applied and the adhesion between the polymer matrix and the transparent substrate is improved.

The pendulum hardness is defined as the product of the number of oscillations of the pendulum and the oscillation period. The ductility of the polymer matrix is measured according to the degree of PDLC hardening. The higher the ductility of the polymer, the lower the pendulum hardness. The measurement method of pendulum hardness is as follows. The pendulum hardness was measured according to ASTM D4366 method using Sheen's K. nig ref. 707KP instrument. The K ㆆ nig pendulum has a triangular shape and weighs 200 ± 0.2 g. Two ball bearings with a diameter of 5 mm are attached to the rotating shaft. The pendulum hardness value is expressed in seconds (s), and the vibration period is 1.4 ± 0.02 s. Pendulum hardness is useful for measuring the softness of a sample.

It is preferable that the PDLC type light adjuster is produced by the manufacturing method of the present invention.

Hereinafter, examples and comparative examples of the present invention will be described, but the scope of the present invention is not limited thereto.

Example 1

- Preparation of liquid crystal dispersion composition for the manufacture of PDLC type light adjuster

As the liquid crystal, 60% by weight of E7 nematic liquid crystal compound of Merk Corp., 1% by weight of Sudan Red (azo red dye, manufactured by Sigma-Aldrich) as a dichroic dye, NOA 65 (urethane oligomer of allyl ether groups, (Irgacure 819, manufactured by Ciba Specialty Chemicals), 25 weight% of long-chain photoinitiator phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide, 10 weight% of hexanediol diacrylate %.

 - Preparation of PDLC type light modulator

The liquid crystal dispersion composition for the production of the PDLC type light adjuster thus prepared was coated on one side of a transparent base plate (175 μm, PET film, Toray Co., Ltd.) having a transparent electrode layer (ITO (Indium Tin Oxide) electrode layer) , And a transparent base plate identical to that of the transparent base plate having the transparent electrode layer formed thereon was laminated. Thereafter, light having a wavelength of 405 nm was irradiated to the liquid crystal dispersion composition layer for preparing a light modulator coated with the transparent substrate through a 405 nm LED lamp (UV energy: 1040 mJ / cm ² ) A PDLC type light adjuster of Example 1 was prepared.

Comparative Example 1

Except that 4 wt% of 1-hydroxy-cyclohexyl-phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals) as a photoinitiator was used to prepare a liquid crystal dispersion composition for PDLC type light adjuster preparation To prepare a PDLC type light adjuster.

Comparative Example 2

In the same manner as in Example 1, a liquid crystal dispersion composition for producing a PDLC type light adjuster was prepared, and light having a wavelength of 365 nm was irradiated using a 365 nm metal halide lamp (UV energy: 1050 mJ / cm ² ) , A PDLC type light adjuster was prepared in the same manner as in Example 1.

Comparative Example 3

Except that 4 wt% of 1-hydroxy-cyclohexylphenylketone (Irgacure 184, manufactured by Ciba Specialty Chemicals), which is a short-wavelength photoinitiator, was used as a photoinitiator. The liquid crystal dispersion composition for PDLC type light- And a light having a wavelength of 365 nm was used by using a 365 nm metal halide lamp (UV energy: 1050 mJ / cm ² ) light source in the step of irradiating light, a PDLC type light adjuster was produced in the same manner as in Example 1 .

Example 2

A liquid crystal dispersion composition for the production of a PDLC type light adjuster was prepared in the same manner as in Example 1, except that 1 wt.% Of a dichroic dye, Oil Blue (an anthraquinone type blue dye, manufactured by Sigma-Aldrich) .

Comparative Example 4

In the same manner as in Example 2, a liquid crystal dispersion composition for producing a PDLC type light adjuster was prepared and light having a wavelength of 365 nm was irradiated using a 365 nm metal halide lamp (UV energy: 1050 mJ / cm ² ) , A PDLC type light adjuster was produced in the same manner as in Example 2. [

Example 3

A liquid crystal dispersion composition for the production of a PDLC type light adjuster was prepared in the same manner as in Example 1, except that 1 wt% of a dichroic dye, Sudan Black (azo type black dye, manufactured by Sigma-Aldrich) .

Comparative Example 5

A liquid crystal dispersion composition for the production of a PDLC type light modulator was prepared in the same manner as in Example 3, and light having a wavelength of 365 nm was irradiated using a 365 nm metal halide lamp (UV energy: 1050 mJ / cm ² ) , A PDLC type light adjuster was produced in the same manner as in Example 2. [

Example 4

A liquid crystal dispersion composition for the production of a PDLC type light adjuster was prepared in the same manner as in Example 1 except that 1 wt% of a mixed dye obtained by mixing 2: 7: 1 of Red, Blue, and Black contained in Examples 1 to 3 as a dye was used To prepare a PDLC type light adjuster.

Comparative Example 6

A liquid crystal dispersion composition for the production of a PDLC type light adjuster was prepared in the same manner as in Example 4, and a 365 nm metal halide lamp (UV intensity: 75 mW / cm ² , UVenergy: 1050 mJ / cm ² ) PDLC type light modulator was produced in the same manner as in Example 2. The light intensity of the PDLC type light modulator was measured in the same manner as in Example 2. [

The light absorption spectra of the dyes and photoinitiators in the examples or comparative examples of the present invention were obtained using a Cary 3 Bio UV-visible spectrophotometer. Samples were prepared by dilution in methylene chloride to a concentration of 0.02 g / l and absorbance was measured using 1 cm long quarts cells.

The PDLC type light adjuster adhesion strength, pendulum hardness, haze, control ratio, color difference and the like produced from Examples 1 to 4 and Comparative Examples 1 to 6 were evaluated as follows, and the results are shown in Table 1. The PDLC type light adjuster adhesion, pendulum hardness, haze, contrast ratio and color difference measurement method are as follows.

  1) peel adhesion strength test

     Peel adhesion was measured using an H5KS instrument from Tinus Olsen according to ASTM D3654 method. At this time, the peeling angle was 180 ㅀ and the peeling speed was 300 mm / min.

  2) Pendulum hardness test

     The pendulum hardness was measured according to ASTM D4366 method using Sheen's K. nig ref. 707KP instrument. The K ㆆ nig pendulum has a triangular shape and weighs 200 ± 0.2 g. Two ball bearings with a diameter of 5 mm are attached to the rotating shaft. The pendulum hardness value is expressed in seconds (s), and the vibration period is 1.4 ± 0.02 s. Pendulum hardness is useful for measuring the softness of a sample.

 3) Optical property measurement

     Off haze and contrast ratio were measured using an Avaspec-2048 visible spectrometer from Avantes. The light source was a halogen lamp (Avalight-HAL, Avantes).

   4) Color difference test

The color difference was measured using a CM-3500D spectrophotometer from Minolta according to the CIE L * a * b * system (Commission Internationale de l'Eclairage, 1976). A color difference (DELTA E ) is calculated according to the following equation.

Δ E = [(ΔL *) ² + (Δ a *) ² + (Δ b *) ² ] ^1/2

Where L * is the lightness, a * and b * are the chromaticity coordinates.

division lamp Photoinitiator dyes Pendulum hardness
(s) Peel adhesion
(N / in) Hayes
(%) Control ratio
(T _on / T _off ) Color difference
(ΔE) Example 1 LED Irga 819 Red 42 1.3 51.2 9.5 12.1 Comparative Example 1 LED Irga 184 Red - - - - - Comparative Example 2 Metal
halide Irga 819 Red 19 0.8 22.3 1.9 43.9 Comparative Example 3 Metal
halide Irga 184 Red - - - - - Example 2 LED Irga 819 Blue 49 1.9 62.4 13.8 8.3 Comparative Example 4 Metal
halide Irga 819 Blue 24 1.1 28.7 2.9 28.8 Example 3 LED Irga 819 Black 31 1.0 45.1 4.5 15.2 Comparative Example 5 Metal
halide Irga 819 Black 15 0.7 16.9 1.7 36.6 Example 4 LED Irga 819 (R / B / BL)
(2/7/1) 45 1.6 59.5 10.1 9.8 Comparative Example 6 Metal
halide Irga 819 (R / B / BL)
(2/7/1) 21 1.0 26.3 2.1 33.5

As shown in Table 1, when irradiated with light having a wavelength of 405 nm or 365 nm including a photoinitiator of a short wavelength band as in Comparative Examples 1 and 3, hardening was hardly carried out, .

Further, in the light modulators of Examples 1 to 4, the pendulum hardness of the light modulating layer was 42s, 49s, 31s, and 45s, respectively, and the light curing was good enough to satisfy 30s or more. The light modulating agent of short wavelength band was used or the metal halide lamp light source The peel adhesion, the haze and the control ratio, which are superior to those of the comparative examples in which light is cured using light having a wavelength of 365 nm, are shown.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing absorbance of a dye included in an embodiment or a comparative example of the present invention by wavelength band. FIG.

FIG. 2 is a graph showing the absorbance of a photoinitiator according to wavelengths in Examples and Comparative Examples of the present invention. FIG.

Claims (7)

Preparing a liquid crystal dispersion composition for producing a PDLC type light adjuster; Forming a liquid crystal dispersion composition for preparing the light adjuster between two transparent base plates having a transparent electrode layer; And irradiating light to the liquid crystal dispersion composition layer for light adjusting body formation, which is formed between the two transparent plate substrates, in a wavelength range of 380 to 460 nm to photo- Wherein the light to be irradiated in the photo-curing step is a long wavelength light emitted from a light emitting diode (LED) light source. delete The method of claim 1, wherein the light emitted from the light emitting diode (LED) is a long wavelength light having a wavelength of 395 nm or 405 nm. The liquid crystal dispersion composition according to claim 1, wherein the liquid crystal dispersion composition prepared in the step of producing the liquid crystal dispersion composition for PDLC type light control comprises liquid crystal, dye, oligomer, monomer and photoinitiator, and the photoinitiator has a wavelength range of 380 to 460 nm A method of manufacturing a PDLC type light adjuster using long wavelength light in which an absorption peak is formed. 5. The composition of claim 4 wherein the photoinitiator is selected from the group consisting of diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide, phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide, bis PDLC-type light modulator using one or more long wavelength light selected from the group consisting of 4-cyclopentadien-1-yl) bis [2,6-difluoro-3- (1H- ≪ / RTI > Two transparent substrate plates on which transparent electrodes are formed; And a light control layer formed between the two transparent base plates and having liquid crystal droplets dispersed in the polymer matrix and the matrix of the polymer matrix, Wherein the light modulating layer has a pendulum hardness of 30 s or more measured after removing the transparent base plate on one side of the two transparent base plates, The PDLC type light adjuster according to any one of claims 1 to 5, wherein the PDLC type light adjuster is a PDLC type light adjuster. delete

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