KR101970730B1 - Azobenzen compound and composition for hologram recording comprising thereof - Google Patents

Abstract

The present invention relates to an azobenzene compound, a hologram recording composition containing the same, a hologram recording medium, a hologram recording material using the same, and a hologram recording or rewriting method, wherein the azobenzene monomer compound of the present invention has optical isomerization at a wavelength of a long wavelength And contains a high refractive index portion capable of increasing the change in refractive index even with a small amount of light irradiation, so that a polymer including an azobenzene monomer compound can be usefully used as a hologram recording / rewriting material by laser irradiation.

Description

TECHNICAL FIELD [0001] The present invention relates to azobenzene compounds and hologram recording compositions containing the same. BACKGROUND ART [0002]

The present invention relates to an azobenzene compound, a hologram recording composition containing the same, a hologram recording medium, a hologram recording material using the same, and a hologram recording or rewriting method.

It is a hologram that records all the wavelength, intensity, and phase difference information that light is reflected on an object and can see complete three-dimensional information of the object. The origin of the hologram is the Greek word holos (whole) and gramm a (information, message).

Holography is a method of recording and reproducing interferograms generated by interference between object waves reflected from a subject and reference waves without subject information detected by a British physicist Dennis Gabor who was born in Hungary in 1948 . When holography was first discovered by Gabor, it was not until the development of the laser that holography was not getting much attention due to unclear results, and since the development of a laser capable of generating coherent light since the 1960s As a result, a clear hologram became possible, and it began to be studied in earnest.

Holograms are widely used in security and military fields due to the complexity of the recording process and the difficulty of duplication. In Korea and other countries, holograms are inscribed on high-denominated banknotes for the purpose of counterfeiting, and ID cards such as passports and driver's licenses are also used for the purpose of preventing forgery. Currently, the biggest market for holograms is for the activation mark attached to cosmetics, liquor, clothing, and so on. Recently, holograms have been used for restoration of artifacts and treasures, educational contents, and so on.

Materials that record holograms used in various applications are materials whose refractive index changes by light. Hologram recording materials developed so far include silver halide, dichromated gelatin (DCG), photoresist, photochromic, photopolymer, and photorefractive materials. However, most materials are materials developed in the United States, Russia, and Germany, which can only be supplied by unfair material transfer agreements (MTAs) and confidentiality agreements (NDAs), and their use is limited to research.

The hologram recording materials described above are mostly single recording materials that can not be rewritten once they are recorded. In order to display the realistic three-dimensional image, it is necessary to erase the hologram image information and to rewrite the material. In 2008 and 2010, Professor Pay Gambiane of the University of Arizona realized the world's first updatable hologram and reported it to Nature. They used a photorefractive composition using an NLO dye as a recording medium. They focused on the fact that a laser may be irradiated under an electric field to cause a difference in refractive index by an electro-optic effect. At that time, the video implementation level reported by them changed once every 2 seconds, but now research is underway to improve the screen switching speed by designing a high-power laser and optical system and optimizing a photorefractive composition.

Azobenzene, which has been used in various dyestuffs in industry, is a molecule capable of trans-cis isomerization by light. When isomerized by light, its geometrical shape is changed. Thus, the azobenzene has optical properties such as light absorption and emission, refractive index And there have been many researches on application of devices using these devices. There have been many studies using azobenzene compounds as hologram rewritable materials. However, the optical isomerization at the laser wavelength for recording and reproducing is not so large, so that the diffraction efficiency is low, or light irradiation with high energy is required for recording / rewriting.

Thus, the inventors of the present invention conducted research on a polymer compound capable of recording and rewriting holograms, and the polymer containing the azobenzene monomer according to the present invention absorbed in the wavelength of the hologram recording laser to a long wavelength and photoisomerization occurred, It is found that the difference in refractive index is increased by laser irradiation of energy, and recording and rewriting of the hologram can be performed.

Japanese Patent Publication (Tokukai) No. 60-88005

An object of the present invention is to provide an azobenzene monomer capable of isomerization in a long wavelength.

Another object of the present invention is to provide a polymer comprising a monomer having an azobenzene monomer and a vinyl acrylic group.

It is still another object of the present invention to provide a composition for hologram recording comprising the azobenzene polymer.

Another object of the present invention is to provide a hologram recording medium in which a recording layer made of the composition for hologram recording is formed on a substrate.

It is still another object of the present invention to provide a hologram recording method using the polymer.

Another object of the present invention is to provide a hologram rewriting method on the hologram recording medium.

In order to achieve the above object,

The present invention provides azobenzene monomers represented by the following general formula (1)

[Chemical Formula 1]

In Formula 1,

R ¹ is at least one substituent selected from the group consisting of -NO ₂ , -CN and -CF ₃ ;

R ² is hydrogen, one or more substituents that are unsubstituted or are straight or branched C ₁ -C ₂₀ alkyl substituted with one or more fluoro;

X is -NR ³ -, -O-, -S- or -S (= O) ₂ -, wherein R ³ is hydrogen, straight or branched C ₁ - C ₅ alkyl;

L is straight or branched C ₁ -C ₂₀ alkylene unsubstituted or substituted with one or more fluoro;

Q is a photopolymerizable functional group containing at least one radically polymerizable double bond in the molecule.

The present invention also relates to an azobenzene monomer represented by the above formula (1); And a monomer having a vinyl acryl group.

Further, the present invention provides a composition for hologram recording comprising an azobenzene polymer.

Furthermore, the present invention provides a hologram recording medium in which a recording layer made of the composition for hologram recording is formed on a substrate.

The present invention also relates to a method for producing a polymer, comprising: (1) preparing the polymer as a thin film; And irradiating the thin film produced in the step 1 with a laser diffraction pattern (step 2).

Furthermore, the present invention provides a hologram rewriting method including the step of irradiating only the reference light used when a hologram is recorded on the photoresist film of the hologram recording medium to the hologram recording medium.

The azobenzene monomer compound of the present invention contains a high refractive index portion capable of increasing photoinduced nitridation at a wavelength of a long wavelength and increasing a change in refractive index even with a small amount of light irradiation. The polymer containing an azobenzene monomer compound is irradiated by laser irradiation It can be used as a hologram recording / rewriting material.

1 is a graph showing an ultraviolet-visible light absorption spectrum of an azobenzene monomer and a comparative example according to the present invention.
2 is a graph showing an ultraviolet-visible light absorption spectrum of the azobenzene polymer according to the present invention.
3 is a graph showing the diffraction efficiency of a green laser-recorded hologram using the azobenzene polymer according to the present invention.

Hereinafter, the present invention will be described in detail.

The present invention provides azobenzene monomers represented by the following general formula (1)

[Chemical Formula 1]

In Formula 1,

R ¹ is at least one substituent selected from the group consisting of -NO ₂ , -CN and -CF ₃ ;

R ² is hydrogen, one or more substituents that are unsubstituted or are straight or branched C ₁ -C ₂₀ alkyl substituted with one or more fluoro;

X is -NR ³ -, -O-, -S- or -S (= O) ₂ -, wherein R ³ is hydrogen, straight or branched C ₁ - C ₅ alkyl;

L is straight or branched C ₁ -C ₂₀ alkylene unsubstituted or substituted with one or more fluoro;

Q is a photopolymerizable functional group containing at least one radically polymerizable double bond in the molecule.

In the azobenzene monomer represented by the formula (1) according to the present invention, a nitro group (-NO ₂ ) is necessarily substituted on the benzene ring, and the position to be substituted is not particularly limited, but an ortho or It is preferably substituted at the para position.

In addition, R ¹ is -NO _2, -CN, and if one or more substituents selected from the group consisting of -CF _3, but not especially limited, and a hydrogen, -NO _2, -CN or -CF _3, one of the substituents preferably , One -CN substituent is more preferable, and when one R ¹ is substituted, it is preferably substituted at the ortho position with respect to the nitro group substituted on the benzene ring.

Further, R ² is not particularly limited as long as R ² is one or more substituents which are hydrogen, unsubstituted or straight or branched C ₁ -C ₂₀ alkyl substituted with at least one fluorine, but are not limited to -CH ₃ , -CH ₂ CH ₃ , -CH ₂ It is preferably at least one substituent selected from the group consisting of F, -CHF ₂ , -CF ₃ and -CH ₂ CF ₃ , more preferably one substituent being -CH ₃ , -CH ₂ CH ₃ or -CF ₃ , And the azo (-N = N-) group substituted on the benzene ring is substituted at the meta position.

X is -NR ³ -, -O-, -S- or -S (= O) ₂ -, wherein R ³ is hydrogen, straight or branched C ₁ is -C ₅ alkyl not particularly _{limited, -NH-, -N (CH 3)} -, -N (CH 2 CH 3) - or -O- is preferable, and -N (CH ₃₎ - in that More preferable.

Further, L is not particularly limited as long as L is straight or branched C ₁ -C ₂₀ alkylene unsubstituted or substituted with one or more fluoro, but unsubstituted straight-chain C ₂ -C ₁₀ alkylene is more preferable.

,

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,

또는

인 것이 바람직하고,

,

,

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또는

인 것이 보다 바람직하다. Q is not particularly limited as long as it is a photo-crosslinkable functional group containing at least one radically polymerizable side-chain vinyl group in the molecule,

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or

, ≪ / RTI >

,

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or

Is more preferable.

The monomer according to the present invention exhibits a high absorbance at a wavelength of about 530 nm which is a green wavelength region, and thus can be effectively used as a composition for a hologram containing a green color (see FIG. 1, Experimental Example 1)

The present invention also relates to an azobenzene monomer represented by the above formula (1); And a monomer having a vinyl acryl group.

The polymer according to the present invention can form a copolymer with the monomer having an azobenzene monomer represented by the general formula (1) and a vinyl acrylate monomer.

In the polymer according to the present invention, the monomer having a vinyl acrylic group may include a monomer containing at least one unsaturated double bond which can be polymerized by a radical mechanism and a monomer containing terminal or pendant ethylenically unsaturated bond have. Specifically, the monomer is not particularly limited as long as it is a monomer capable of performing photopolymerization with the photocrosslinking functional group of X of the azobenzene monomer represented by the general formula (1), but monomers having a vinyl acryl group are preferable. Examples thereof include vinyl acrylate, Acrylate, vinyl ethyl acrylate, vinyl ethyl methacrylate, vinyl octyl methacrylate, vinyl hexyl methacrylate, and vinyl butyl methacrylate.

The polymer according to the present invention may be a block copolymer in which the copolymerization sequence of the azobenzene monomer A and the vinyl acrylate group-containing monomer represented by the formula (1) forms a block chain such as AAAAAA-BBBBBB- and a random chain such as ABAABABABBA- And the like. The arrangement of the monomers can be appropriately used in consideration of an increase in the desired refractive index and physical properties.

Further, the polymer according to the present invention, but the ratio of the monomer having an azobenzene monomer and vinyl acrylate of the formula (1) is, if the range of the refractive index change desired before and after the light irradiation to the polymer obtained is not particularly limited, and represented by the formula (1) The azobenzene monomer is used in an amount of 0.5 to 20 mol%, preferably 1 to 15 mol%, more preferably 1 to 10 mol%, based on the whole monomers. If the amount of the azobenzene monomer represented by the above formula (1) is less than 0.5 mole%, the degree of sensitivity to light is too low, so too much energy is required to record the hologram, and if it exceeds 20 mole% The efficiency can be rapidly lowered by absorbing the light.

Further, the polymer according to the present invention can be obtained through the usual polymerization reaction of the azobenzene monomer represented by the formula (1) and the vinyl acrylate monomer, but it is preferred that the monomer is prepared through a radical polymerization reaction using a radical initiator such as AIBN Do.

The polymer according to the present invention has a property that when the long wavelength light is irradiated, the azobenzene structure is cis-trans isomerized to increase and modulate the refractive index before and after the irradiation of light, wherein the refractive index change is 0.01 to 0.04. Also, the wavelength of the preferred light may be about 530 nm.

Therefore, the polymer according to the present invention includes a high refraction index portion capable of absorbing a wavelength of a long wavelength to cause optical isomerization and capable of increasing a refractive index change even by a small amount of light irradiation, It can be usefully used as a recording composition.

Further, the present invention provides a photochemically refractive-index-changing polymer composition comprising an azobenzene polymer.

As described above, the photochemically refractive-index-changing polymer composition according to the present invention is an azobenzene polymer having a high refractive index portion capable of absorbing a wavelength of a long wavelength to cause optical isomerization and capable of increasing a change in refractive index even with a small amount of light irradiation And, if necessary, one or more additives selected from photoinitiators, sensitizers, and chain transfer agents. By including these additives, it is possible to improve the crosslinking reactivity of the photo-crosslinkable functional group containing at least one radically polymerizable double bond in the molecule of the azobenzene monomer represented by the formula (1) by irradiation with light, Can be more preferably generated.

The present invention also provides a refractive index control method comprising the step of modulating the refractive index by irradiating light onto the above-mentioned optical refractive index modulation polymer composition.

Specifically, in the refractive index control method of the present invention, light can be irradiated after an appropriate molding process is performed using the photochemically refractive-index-changing polymer composition.

In the refractive index control method according to the present invention, the wavelength of the light for modulating the refractive index is preferably about 530 nm, and the intensity of light is usually 1000 mJ / cm ² to 100 mJ / cm ² , preferably 100 To 300 mJ / cm < ² >

The present invention also provides a composition for hologram recording comprising an azobenzene polymer.

As described above, the composition for recording a hologram according to the present invention includes an azobenzene polymer having a high refractive index portion capable of absorbing a wavelength of a long wavelength to cause optical isomerization and capable of increasing a change in refractive index even with a small amount of light irradiation Thereby making it possible to form a volume phase hologram having high diffraction efficiency, high transparency and reproduction wavelength reproducibility.

In order to improve the weather resistance, heat resistance, chemical stability, storage stability and the like of the hologram recording medium according to the present invention, the composition for hologram recording may be a conventional hologram recording composition such as plasticizers, thickeners, thermal polymerization inhibitors and chain transfer agents known in the art Additives. At this time, the additive may be added so as not to deviate from the effect of the present invention by being unreactive with the monomer or polymer according to the present invention.

Furthermore, the present invention provides a hologram recording medium in which a recording layer made of the composition for hologram recording is formed on a substrate.

In the hologram recording medium according to the present invention, the substrate is preferably an optically transparent material and is not particularly limited. For example, a glass plate, a PET plate or film, a polycarbonate plate or film, a polymethyl methacrylate plate or a film It can be the same plastic plate or film. The thickness of the substrate may be 0.01 to 10 mm, and the substrate is usually flat, but may be curved or may have a concavo-convex structure on its surface if necessary.

The present invention also provides a process for producing a thin film of a polymer comprising the azobenzene monomer (step 1); And irradiating the thin film produced in the step 1 with a laser diffraction pattern (step 2).

In the hologram recording method according to the present invention, step 1 is a step of producing a polymer containing the azobenzene monomer as a thin film.

Specifically, the method of producing a polymer as a thin film is not particularly limited as long as it is a method of coating a substrate with a polymer such as spin coating, bar coating, dip coating, and the like. It may be prepared by coating the substrate on one side or by sandwiching the polymer between the substrate and the substrate.

In the hologram recording method according to the present invention, step 2 is a step of irradiating the thin film produced in step 1 with a laser diffraction pattern.

In this case, the diffraction pattern may be a diffraction pattern due to interference between the reference light and object light when recording an analog hologram, or a computer generated diffraction pattern when recording a digital hologram.

Furthermore, the present invention provides a hologram rewriting method including the step of irradiating only the reference light used when a hologram is recorded on the photoresist film of the hologram recording medium to the hologram recording medium.

The hologram can be rewritten by diffracting the reference light in the interference fringe. Such a hologram rewriting method is well known in the art together with the hologram recording method, and thus a detailed description thereof will be omitted.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples and Experimental Examples.

Example 1 Synthesis of 4- (N- (2-methacryloyloxyethyl) -N-methylamino) -4 '- [2-cyano-4-nitrophenyl] ethynyl- Manufacturing

Step 1: Preparation of 4- (N- (2-hydroxyethyl) -N-methylamino) -4'-bromo-3'-methyl azobenzene

To the reaction vessel were added 3 g (16.12 mmol) of 4-bromo-3-methylaniline, 12 mL of distilled water and 8.35 mL of hydrochloric acid (37%) and 1.77 g (25.79 mmol) of sodium nitrite dissolved in 3.5 mL of distilled water at 0 Slowly added to the reaction vessel, and stirred for 30 minutes. Then, 2- (methyl (phenyl) amino) ethanol was dissolved in 115 mL of methanol and the mixture was stirred at room temperature for 2 hours. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction, followed by extraction with ethyl acetate. After evaporating all the solvent, the product was separated by column chromatography (hexane / ethyl acetate = 3: 1) to obtain an orange solid (2 g, 35%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.84 (d, 2H) 7.71 (s, 1H) 7.63 (d, 1H) 7.55 (s, 1H) 6.81 (d, 2H) 3.88 (t, 2H) 3.64 (t, 2 H) 3.14 (s, 3 H) 2.43 (s, 3 H)

Step 2: Preparation of 4- (N- (2-hydroxyethyl) -N-methylamino) -3'-methyl-4'-trimethylsilylethynyl azobenzene

3.7 g (9.1 mmol) of 4- (N- (2-hydroxyethyl) -N-methylamino) -4'-bromo-3'-methyl azobenzene was dissolved in 26 mL of triethylamine, (0.91 mmol) of triphenylphosphine oxide, 0.67 g (0.91 mmol) of bis (triphenylphosphine) palladium (II) chloride and 0.36 g (1.9 mmol) of copper iodide were sequentially added dropwise After the addition, the temperature was raised to 80 캜. 2 mL (13.65 mmol) of ethynyltrimethylsilane dissolved in 2 mL of tetrahydrofuran at 80 占 폚 was slowly added to the reaction vessel and stirred for one day. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction and extracted with ethyl acetate. After evaporating all the solvent, the residue was separated by column chromatography (hexane / methylene chloride = 2: 1) to obtain a red liquid (2.1 g, 60%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.84 (d, 2H) 7.71 (s, 1H) 7.63 (d, 1H) 7.55 (s, 1H) 6.81 (d, 2H) 3.88 (q, 2H) 3.64 (t, 2 H) 3.14 (s, 3 H) 2.43 (s, 3 H) 0.28 (s, 9 H)

Step 3: Preparation of 4- (N- (2-hydroxyethyl) -N-methylamino) -4'-ethynyl-3'-methylazobenzene

2.1 g (5.8 mmol) of 4- (N- (2-hydroxyethyl) -N-methylamino) -3'-methyl-4'-trimethylsilylethynylazobenzene were added to a reaction vessel, 12 mL of triethylamine, mL, calcium carbonate (1.6 g, 11.6 mmol) was added, and the mixture was stirred at room temperature for 2 hours. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction. The reaction mixture was extracted with ethyl acetate and the solvent was evaporated to obtain the target compound.

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.84 (d, 2H) 7.71 (s, 1H) 7.63 (d, 1H) 7.55 (s, 1H) 6.81 (d, 2H) 3.88 (q, 2H) 3.64 (t, 2 H) 3.14 (s, 3 H) 2.43 (s, 3 H)

Step 4: Preparation of 4- (N- (2-Hydroxyethyl) -N-methylamino) -4 '- [2-cyano-4-nitrophenyl] ethynyl-3'-methyl azobenzene

The reaction vessel was charged with 1 g (4.3 mmol) of 2-bromo-5-nitrobenzonitrile in 10 mL of triethylamine and 10 mL of tetrahydrofuran to remove oxygen, and bis (triphenylphosphine) palladium (II) chloride 0.4 g (0.52 mmol) of copper iodide and 0.2 g (1.04 mmol) of copper iodide were successively added thereto, followed by raising the temperature to 80 ° C. 1.7 g (5.7 mmol) of 4- (N- (2-hydroxyethyl) -N-methylamino) -4'-ethynyl-3'-methylazobenzene dissolved in 15 mL of tetrahydrofuran was slowly added After the addition, the mixture was stirred for one day. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction and extracted with ethyl acetate. After evaporating all the solvent, the product was separated by column chromatography (hexane / ethyl acetate = 2: 1) to obtain a brown solid (0.38 g, 21%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 8.57 (s, 1H) 8.44 (d, 1H) 7.88 (d, 2H) 7.76 (d, 1H) 7.81 (d, 1H) 7.76 (s, 2H) 6.81 (d, 2H) 3.9 (q, 2H) 3.64 (t, 2H) 3.14 (s, 3H)

Step 5: Preparation of 4- (N- (2-methacryloyloxyethyl) -N-methylamino) -4 '- [2-cyano-4-nitrophenyl] ethynyl-3'-

The reaction vessel was charged with 0.36 g (0.84 mmol) of 4- (N- (2-hydroxyethyl) -N-methylamino) -4 '- [2- cyano- ) Was dissolved in 15 mL of tetrahydrofuran, and then 10 mg (0.1 mmol) of 4- (dimethylamino) pyrrolidine was added thereto, followed by deoxygenation. At 0 < 0 > C, 0.16 mL (1.68 mmol) of methacryloyl chloride was added slowly and the mixture was stirred at room temperature for 3 hours. An excessive amount of distilled water is poured into the reaction mixture to terminate the reaction, followed by extraction with ethyl acetate. After evaporating all the solvent, the product was separated by column chromatography (hexane / ethyl acetate = 3: 1) to obtain a brown solid compound of Example 1 (40 mg, 10%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 8.56 (d, 1H) 8.43 (d, 1H) 7.89 (d, 2H) 7.82 (d, 1H) 7.77 (d, 1H) 7.76 (s, 2H) 6.81 (d, 2H), 6.08 (s, 1H), 5.57 (s, 1H)

Example 2 Synthesis of 4- (N- (6-methacryloyloxyhexyl) -N-methylamino) -4 '- [2-cyano-4-nitrophenyl] ethynyl- Produce

Step 1: Preparation of N- (6-hydrooxyhexyl) -N-methylaminobenzene

13.53 mL (125.07 mmol) of N-methylaniline was added to the reaction vessel and 46 mg (0.27 mmol) of potassium iodide and 6.0 g (150 mmol) of sodium hydroxide were added to the reaction vessel. 17 mL (137.58 mmol) was slowly added to the reaction vessel, followed by stirring at 150 DEG C for one day. An excess of distilled water was poured into the reaction mixture to terminate the reaction and extracted with methylene chloride. After evaporating all the solvent, the product was separated by column chromatography (hexane / ethyl acetate = 3: 1) to obtain a white liquid (27.8 g, 84%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.22 (q, 2H) 6.68 (q, 4H) 3.63 (t, 2H) 3.33 (q, 2H) 2.90 (s, 3H) 1.58 (m, 4H) 1.36 (m, 4H)

Step 2: Preparation of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -4'-bromo-3'-

3 g (16.12 mmol) of 4-bromo-3-methylaniline, 12 mL of distilled water and 8.35 mL of hydrochloric acid (37%) were added to the reaction vessel and 1.77 g (25.79 mmol) of sodium nitrite dissolved in 3.5 mL of distilled water Added to the reaction vessel, and stirred for 30 minutes. 3.3 g (16.12 mmol) of N- (6-hydrooxyhexyl) -N-methylaminobenzene was dissolved in 115 mL of methanol and slowly added to the reaction vessel, followed by stirring at room temperature for 2 hours. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction and extracted with ethyl acetate. After evaporating all the solvent, the residue was separated by column chromatography (hexane / ethyl acetate = 3: 1) to obtain a red liquid (4.8 g, 73%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.88 (d, 2H) 7.77 (s, 1H) 7.6 (d, 1H) 7.4 (d, 1H) 6.7 (d, 2H) 4.1 (q, 2H) 3.6 (t, 2H) 3.0 (s, 3H) 2.4 (s, 3H) 1.6 (m, 4H)

Step 3: Preparation of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -3'-methyl-4'-trimethylsilylethynyl azobenzene

3.9 g (9.6 mmol) of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -4'-bromo-3'-methyl azobenzene was dissolved in 26 mL of triethylamine, (0.96 mmol) of triphenylphosphine oxide, 0.67 g (0.96 mmol) of bis (triphenylphosphine) palladium (II) chloride and 0.36 g (1.32 mmol) of copper iodide were sequentially added After that, the temperature was raised to 80 ° C. Ethynyltrimethylsilane (2 mL, 14.4 mmol) dissolved in 2 mL of tetrahydrofuran at 80 ° C was added slowly to the reaction vessel and stirred for one day. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction and extracted with ethyl acetate. After evaporating all the solvent, the residue was separated by column chromatography (hexane / methylene chloride = 2: 1) to obtain a red liquid (3.3 g, 82%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.88 (d, 2H) 7.77 (s, 1H) 7.6 (d, 1H) 7.4 (d, 1H) 6.7 (d, 2H) 4.1 (q, 2H) 3.6 (s, 3H) 1.6 (m, 4H) 0.28 (s, 9H)

Step 4: Preparation of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -4'-ethynyl-3'-methyl azobenzene

3.3 g (7.8 mmol) of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -3'-methyl-4'-trimethylsilylethynylazobenzene was added to a reaction vessel, to which 15 mL , Dissolved in methanol (15 mL), calcium carbonate (2.1 g, 15.6 mmol) was added, and the mixture was stirred at room temperature for 2 hours. An excess of distilled water was poured into the reaction mixture to terminate the reaction. The reaction mixture was extracted with ethyl acetate and the solvent was evaporated.

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.88 (d, 2H) 7.77 (s, 1H) 7.6 (d, 1H) 7.4 (d, 1H) 6.7 (d, 2H) 3.6 (q, 2H) 3.4 (m, 3 H) 1.4 (m, 5 H)

Step 5: Preparation of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -4 '- [2-cyano-4-nitrophenyl] ethynyl-3'-

The reaction vessel was charged with 1.5 g (6.6 mmol) of 2-bromo-5-nitrobenzonitrile dissolved in 10 mL of triethylamine and 10 mL of tetrahydrofuran, and oxygen was removed, and bis (triphenylphosphine) palladium 0.5 g (0.66 mmol) of copper iodide and 0.25 g (1.32 mmol) of copper iodide were successively added thereto, followed by increasing the temperature to 80 ° C. 3 g (8.5 mmol) of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -4'-ethynyl-3'-methylazobenzene dissolved in 20 mL of tetrahydrofuran was added to the reaction vessel After the addition slowly, the mixture was stirred for one day. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction and extracted with ethyl acetate. After evaporating all the solvent, the product was separated by column chromatography (hexane / methylene chloride = 1: 1) to obtain a brown solid (1.25 g, 39%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 7.88 (d, 2H) 7.77 (s, 1H) 7.63 (d, 1H) 7.41 (d, 1H) 6.72 (d, 2H) 3.62 (q, 2H) 3.41 (s, 3H), 2.45 (s, 3H), 1.66 (m, 3H), 1.43 (m, 5H)

Step 6: Preparation of 4- (N- (6-methacryloyloxyhexyl) -N-methylamino) -4 '- [2-cyano-4-nitrophenyl] ethynyl-

The reaction vessel was charged with 1.25 g (2.5 mmol) of 4- (N- (6-hydrooxyhexyl) -N-methylamino) -4 '- [2- cyano- ) Was dissolved in 35 mL of tetrahydrofuran, and 30 mg (0.1 mmol) of 4- (dimethylamino) pyrrolidine was added thereto, followed by deoxygenation. At 0 < 0 > C, 0.5 mL (5.2 mmol) of methacrolein chloride was added slowly and the mixture was stirred at room temperature for 3 hours. An excess amount of distilled water was poured into the reaction mixture to terminate the reaction and extracted with ethyl acetate. After evaporating all the solvent, the product was separated by column chromatography (hexane / ethyl acetate = 4: 1) to obtain a red solid (1.25 g, 39%).

^{1 H NMR (400 MHz, CDCl} 3), δ = 8.56 (s, 1H) 8.42 (d, 1H) 7.87 (d, 2H) 7.81 (d, 1H) 7.75 (s, 1H) 7.71 (s, 2H) 6.75 (s, 3H) 1.95 (s, 3H), 1.72 (m, 2H), 6.95 (s, , ≪ / RTI > 4H) 1.54 (m, 4H)

≪ Example 3 > Preparation of hologram recording composition according to the present invention

The reaction vessel was charged with methyl methacrylate (1.35 g, 13.49 mmol), 2,2'-azobis (2-methylpropionitrile) (0.019 g 0.5 wt% Methyl azobenzene (0.4 g, 0.71 mmol) was added to a solution of N-methyl (3-methylacryloxyhexyl) -N-methylamino) -4'- Pyrrolidone, and the mixture was stirred at 75 DEG C for 48 hours under a nitrogen atmosphere. The reaction mixture was precipitated in an excess amount of methanol to terminate the reaction. After the filtration, the reaction mixture was dissolved in a small amount of tetrahydrofuran and then re-precipitated in an excess amount of methanol to obtain 0.27 g.

GPC Mn 21,378, Mw 40,769, PDI 1.9, UV-vis (μ _max , nm) 485

¹ H NMR (CDCl ₃隆): 0.85 (s, 3H), 1.23 (s, 3H), 1.41 (s, 8H) ), 3.63 (d, 34H), 3.95 (t, 2H), 6.73 (s, 2H), 7.69-7.86 (m, 6H), 8.41

COMPARATIVE EXAMPLE 1 Preparation of (E) -6- (4 - ((4 - ((4-nitrophenyl) ethynyl) phenyl) diazenyl) phenoxy) hexyl methacrylate

(E) -6- (4 - ((4 - ((4-nitrophenyl) ethynyl) phenyl) diazenyl) phenoxy) hexyl methacrylate was prepared by a method similar to that of Example 2.

Comparative Example 2 Preparation of (E) -6- (4 - ((4 - ((4-cyanophenyl) ethynyl) phenyl) diazenyl) phenoxy) hexyl methacrylate

By a method similar to that of Example 2 (E) -6- (4 - ((4 - ((4-cyanophenyl) ethynyl) phenyl) diazenyl) phenoxy) hexyl methacrylate.

COMPARATIVE EXAMPLE 3 Preparation of (E) -6- (methyl) -4 - ((4 - ((4-nitrophenyl) ethynyl) phenyl) diazenyl) phenyl) amino) hexyl methacrylate

By a method similar to that of Example 2 (E) -6- (Methyl (4 - ((4 - ((4-nitrophenyl) ethynyl) phenyl) diazenyl) phenyl) amino) hexyl methacrylate.

EXPERIMENTAL EXAMPLE 1 Experiment for Measuring Absorbance of Monomer Compound According to the Present Invention

To examine the absorbance of the azobenzene monomer according to the present invention, the compounds of Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 2 were dissolved in a dichloromethane solvent and UV-Vis. The absorbance of each wavelength was measured from 300 nm to 700 nm in a cell for absorption spectrum measurement, and the results are shown in FIG.

1 is a graph showing the absorbance of the compounds of Comparative Example 1, Comparative Example 2, Comparative Examples 3 and 2 according to wavelengths.

As can be seen from FIG. 1, in the case of Comparative Example 1 and Comparative Example 2, the absorbance was high at a wavelength of about 380 nm which is an ultraviolet wavelength region. In addition, in the case of Comparative Example 3, the absorbance at a wavelength of 460 nm, which is a blue color wavelength region, is high. Meanwhile, in the case of Example 2, which is a monomer compound according to the present invention, it can be confirmed that the absorbance is high at a wavelength of about 530 nm which is a green wavelength region.

Therefore, the compound according to the present invention exhibits a high absorbance in the green wavelength range, which hitherto can not be obtained by the monomer for hologram, and thus can be effectively used as a composition for preparing a hologram including a green color.

Experimental Example 2: Measurement of absorbance of a polymer compound according to the present invention

In order to examine the absorbance of the azobenzene polymer compound according to the present invention, the azobenzene polymer compound of Example 3 was dissolved in a solvent such as toluene and anisole, and then spin-coated on a glass substrate to obtain a thin film having a thickness of 1 micrometer or less. To 700 nm, and the results are shown in Fig.

2 is a graph showing the absorbance of the azobenzene polymer according to the present invention

As can be seen from FIG. 2, the polymeric compound according to the present invention has maximum absorption at 480 nm green and absorption up to 550 nm.

Therefore, the compound according to the present invention exhibits high absorbance in the green wavelength range, which hologram recording polymer can not provide, and thus can be usefully used as a composition for preparing a hologram including a green color.

Experimental Example 3 Measurement of Diffraction Efficiency of Polymer According to the Present Invention

Four wave mixing (FWM) measurements were used to characterize the diffraction efficiency of the polymer according to the present invention. The FWM measurement setup consists largely of a part for recording a hologram on a film using a recording beam and a part for measuring the diffraction efficiency value of the azobenzene polymer film in real time in synchronism with it. The diffraction pattern was recorded using a 532 nm laser and the readout beam was designed to be incident at the same angle as the laser beam incident on the normal direction of the film in order to measure the diffraction efficiency of the recorded hologram. The readout beam incident on the sample is diffracted by the recorded hologram and can measure the intensity of the beam diffracted through the photodiode in real time. The diffraction efficiency can be obtained from the ratio of the intensity of the incident beam to the intensity of the diffracted beam. A conceptual diagram of the FWM is shown in Fig.

3 is a graph showing the diffraction efficiency of the hologram recorded with the green laser of the azobenzene polymer film according to the present invention.

As can be seen from FIG. 3, the diffraction efficiency of the green laser-recorded hologram of the azobenzene polymer film according to the present invention is excellent.

Therefore, the polymer containing the azobenzene monomer compound according to the present invention can be usefully used as a hologram recording / rewriting material by laser irradiation.

Claims (10)

An azobenzene monomer represented by the following formula (1); And
A monomer having a vinyl acryl group; In the polymer formed by the polymerization of
Wherein the polymer is formed by polymerization of a double bond of Q in an azobenzene monomer represented by the following formula (1) and a vinyl group in a monomer having a vinyl acryl group:
[Chemical Formula 1]

(In the formula 1,
X is -NR ³ -, -O-, -S- or -S (= O) ₂ -, wherein R ³ is hydrogen, straight or branched C ₁ - C ₅ alkyl;
L is straight or branched C ₁ -C ₂₀ alkylene unsubstituted or substituted with one or more fluoro;
Q is a photo-crosslinkable functional group containing at least one radically polymerizable double bond in the molecule).
The method according to claim 1,
X is -NH-, -N (CH ₃ ) -, -N (CH ₂ CH ₃ ) - or -O-;
L is straight or branched C ₂ -C ₁₀ alkylene unsubstituted or substituted with one or more fluoro;
Q is a photo-crosslinkable functional group containing at least one radically polymerizable side-chain vinyl group in the molecule.
The method according to claim 1,
Q is

,

,

,

,

,

,

,

,

,

or

.
delete A photochemically refractive-index-changing polymer composition comprising the polymer of claim 1.
A hologram recording composition comprising the polymer of claim 1.
The method according to claim 6,
Wherein the composition for hologram recording absorbs a wavelength of 400-600 nm.
A hologram recording medium in which a recording layer made of the composition for hologram recording of claim 6 is formed on a substrate.
A process for producing a thin film of the polymer of claim 1 (step 1); And
And irradiating the thin film produced in the step 1 with a laser diffraction pattern (step 2).
A hologram recording method comprising the steps of: irradiating only the reference light used when recording a hologram on the hologram recording medium of claim 8 to the hologram recording medium.

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