KR20240077211A - Dye compound, photopolymer composition, holographic recording medium, optical element and holographic recording method using the same - Google Patents

Abstract

The present invention provides a compound with a novel structure, a photopolymer composition containing the compound as a dye, a holographic recording medium manufactured from the photopolymer composition, an optical element containing the holographic recording medium, and a holographic recording method using the holographic recording medium. It's about.

Description

Dye compound, photopolymer composition, holographic recording medium, optical element and holographic recording method {DYE COMPOUND, PHOTOPOLYMER COMPOSITION, HOLOGRAPHIC RECORDING MEDIUM, OPTICAL ELEMENT AND HOLOGRAPHIC RECORDING METHOD USING THE SAME}

The present invention relates to dye compounds, photopolymer compositions, holographic recording media, optical elements and holographic recording methods.

Hologram recording media records information by changing the refractive index within the holographic recording layer within the media through an exposure process, and reproduces the information by reading the change in refractive index within the recorded media.

When using photopolymer (photosensitive resin), optical interference patterns can be easily stored as holograms by photopolymerization of low-molecular monomers, so optical lenses, mirrors, deflection mirrors, filters, diffusion screens, diffraction members, light guides, and waveguides , holographic optical elements that function as projection screens and/or masks, optical memory system media and light diffusion plates, optical wavelength splitters, and reflective and transmissive color filters can be used in various fields.

Typically, a photopolymer composition for producing a hologram includes a polymer binder, a monomer, and a photoinitiator, and laser interference light is irradiated to a photosensitive film prepared from this composition to induce local photopolymerization of the monomer.

In this photopolymerization process, the refractive index increases in areas where there is a relatively large amount of monomer, and the refractive index becomes relatively low in areas where there is a relatively large amount of polymer binder, resulting in refractive index modulation. This refractive index modulation creates a diffraction grating. The refractive index modulation value n is affected by the thickness of the photopolymer layer and the diffraction efficiency (DE), and the angular selectivity becomes wider as the thickness becomes thinner.

Recently, along with the demand for the development of materials that can maintain high diffraction efficiency and stable holograms, various attempts have been made to manufacture photopolymer layers that have a small thickness and a high refractive index modulation value.

The present invention is intended to provide a dye compound, photopolymer composition, holographic recording medium, optical element, and holographic recording method that have a small thickness yet realize a large refractive index modulation value and have improved durability against temperature and humidity.

According to one embodiment of the present invention, a compound represented by the following formula (1) is provided.

[Formula 1]

In Formula 1, R ₁ to R ₅ are the same or different from each other, and each independently represents hydrogen, deuterium, halogen group, nitrile group, nitro group, hydroxy group, carboxyl group, alkyl group of 1 to 20 carbon atoms, and cycloalkyl group of 4 to 20 carbon atoms. , alkoxy group of 1 to 20 carbon atoms, aryloxy group of 6 to 20 carbon atoms, alkylthoxy group of 1 to 20 carbon atoms, arylthoxy group of 6 to 20 carbon atoms, alkylsulfoxy group of 1 to 20 carbon atoms, 6 to 20 carbon atoms An arylsulfoxy group, an alkenyl group having 2 to 20 carbon atoms, an amine group, an aryl group having 6 to 20 carbon atoms, -Y-(CH ₂ )pO-Ar ₁ , or a monovalent functional group derived from a heterocyclic aromatic compound, and the R ₁ to At least one of R ₅ is -Y-(CH ₂ )pO-Ar ₁ or a monovalent functional group derived from a heterocyclic aromatic compound, Y is an ether group or an ester group, p is an integer of 1 or more, and Ar ₁ is a carbon number It is an aromatic compound of 3 or more, and R ₆ to R ₉ are the same or different from each other, and are each independently hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, and cycloalkyl with 4 to 20 carbon atoms. is a carboxylate group or _{an aryl carboxylate group having 6 to 20 carbon atoms, and X 1 and} are the same or different from each other and are independently integers between 0 and 4.

In addition, according to another embodiment of the present invention, a polymer matrix or a precursor thereof; A dye containing the compound of the above embodiment; Photoreactive monomer; A photopolymer composition is provided, including a photoinitiator.

Additionally, according to another embodiment of the present invention, a hologram recording medium manufactured from the photopolymer composition of the above embodiment can be provided.

Additionally, according to another embodiment of the present invention, an optical element including the hologram recording medium of the above embodiment is provided.

In addition, according to another embodiment of the present invention, a holographic recording method is provided, comprising the step of selectively polymerizing the photoreactive monomer included in the photopolymer composition of the above embodiment by a coherent light source.

Hereinafter, the dye compound, photopolymer composition, holographic recording medium, optical element, and holographic recording method of specific embodiments of the invention will be described in more detail.

Unless explicitly stated herein, terminology is intended to refer only to specific embodiments and is not intended to limit the invention.

As used herein, singular forms include plural forms unless phrases clearly indicate the contrary.

Throughout this specification, unless otherwise specified, “include” or “contains” refers to the inclusion of any component (or component) without particular limitation, excluding the addition of other components (or components). cannot be interpreted as

In addition, unless it is specified that the steps constituting the manufacturing method described in this specification are sequential or continuous, or there is another special class, one step and other steps constituting one manufacturing method are performed in the order described in the specification. It is not interpreted as limited. Accordingly, the order of the structural steps of the manufacturing method can be changed within a range that can be easily understood by a person skilled in the art, and in this case, changes that are obvious to those skilled in the art are included in the scope of the present invention.

Additionally, unless otherwise stated herein, the weight average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, the prepolymer or copolymer is dissolved in chloroform to a concentration of 2 mg/ml, then 20 μl is injected into GPC, and GPC analysis is performed at 40°C. At this time, the mobile phase of GPC uses chloroform and flows at a flow rate of 1.0 mL/min, the column uses two Agilent Mixed-Bs connected in series, and the detector uses an RI Detector. The Mw value is derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weights of the polystyrene standard specimens were 2,000 g/mol, 10,000 g/mol, 30,000 g/mol, 70,000 g/mol, 200,000 g/mol, 700,000 g/mol, 2,000,000 g/mol, 4,000,000 g/mol, and 10,000,000. Nine types of g/mol were used.

In this specification, the term "substitution" means bonding with another functional group in place of a hydrogen atom in a compound, and the position to be substituted is not limited as long as it is the position where the hydrogen atom is substituted, that is, a position where the substituent can be substituted, and if two or more substitutions are made, , two or more substituents may be the same or different from each other.

As used herein, the term “substituted or unsubstituted” refers to deuterium; halogen group; Cyano group; nitro group; hydroxyl group; carbonyl group; ester group; imide group; amide group; primary amino group; carboxyl group; sulfonic acid group; sulfonamide group; Phosphine oxide group; Alkoxy group; Aryloxy group; Alkylthioxy group; Arylthioxy group; Alkyl sulphoxy group; Aryl sulfoxy group; silyl group; boron group; Alkyl group; Cycloalkyl group; alkenyl group; Aryl group; Aralkyl group; Aralkenyl group; Alkylaryl group; Alkoxysilylalkyl group; Arylphosphine group; or substituted or unsubstituted with one or more substituents selected from the group consisting of heterocyclic groups containing one or more of N, O and S atoms, or substituted or unsubstituted with two or more of the above-exemplified substituents linked. . For example, “a substituent group in which two or more substituents are connected” may be a biphenyl group. That is, the biphenyl group may be an aryl group, or it may be interpreted as a substituent in which two phenyl groups are connected.

In the present specification, the alkyl group is a monovalent functional group derived from an alkane and may be straight-chain or branched, and the number of carbon atoms of the straight-chain alkyl group is not particularly limited, but is preferably 1 to 20. Additionally, the branched chain alkyl group has 3 to 20 carbon atoms. Specific examples of alkyl groups include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n. -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl- Propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, 2,6-dimethylheptan-4-yl, etc., but are not limited to these. The alkyl group may be substituted or unsubstituted.

In the present specification, the alkylene group is a divalent functional group derived from an alkane, for example, straight chain, branched or cyclic, such as methylene group, ethylene group, propylene group, isobutylene group, sec- It may be a butylene group, tert-butylene group, pentylene group, hexylene group, etc.

In the present specification, the aryl group is a monovalent functional group derived from arene and may be a monocyclic aryl group or a polycyclic aryl group. The monocyclic aryl group may be a phenyl group, biphenyl group, terphenyl group, etc., but is not limited thereto. The polycyclic aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, perylenyl group, chrysenyl group, fluorenyl group, etc., but is not limited thereto. The aryl group may be substituted or unsubstituted.

In the present specification, the arylene group is a divalent functional group derived from arene, and the description of the aryl group described above can be applied, except that it is a divalent functional group.

In this specification, , or means a bond connected to another substituent.

In this specification, a direct bond or single bond means that no atom or atomic group exists at the corresponding position and is connected by a bond line.

In this specification, (meth)acrylate means methacrylate or acrylate.

In this specification, (co)polymer refers to a homopolymer or copolymer, and the copolymer includes random copolymer, block copolymer, and graft copolymer.

In addition, in this specification, a hologram refers to a recording medium in which optical information is recorded in the entire visible range and near-ultraviolet range (300-800 nm) through an exposure process, for example, in-line (Gabor )) hologram, off-axis hologram, full-aperture hologram, white light transmission hologram ("rainbow hologram"), Denisyuk hologram, biaxial reflection hologram, edge-literature ( Edge-literature includes all visual holograms such as holograms or holographic stereograms.

According to one embodiment of the invention, a compound represented by the following formula (1) may be provided .

[Formula 1]

In Formula 1, R ₁ to R ₅ are the same or different from each other, and each independently represents hydrogen, deuterium, halogen group, nitrile group, nitro group, hydroxy group, carboxyl group, alkyl group of 1 to 20 carbon atoms, and cycloalkyl group of 4 to 20 carbon atoms. , alkoxy group of 1 to 20 carbon atoms, aryloxy group of 6 to 20 carbon atoms, alkylthoxy group of 1 to 20 carbon atoms, arylthoxy group of 6 to 20 carbon atoms, alkylsulfoxy group of 1 to 20 carbon atoms, 6 to 20 carbon atoms An arylsulfoxy group, an alkenyl group having 2 to 20 carbon atoms, an amine group, an aryl group having 6 to 20 carbon atoms, -Y-(CH ₂ )pO-Ar ₁ , or a monovalent functional group derived from a heterocyclic aromatic compound, and the R ₁ to At least one of R ₅ is -Y-(CH ₂ )pO-Ar ₁ or a monovalent functional group derived from a heterocyclic aromatic compound, Y is an ether group or an ester group, p is an integer of 1 or more, and Ar ₁ is a carbon number It is an aromatic compound of 3 or more, and R ₆ to R ₉ are the same or different from each other, and are each independently hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, and cycloalkyl with 4 to 20 carbon atoms. is a carboxylate group or _{an aryl carboxylate group having 6 to 20 carbon atoms, and X 1 and} are the same or different from each other, and are independently integers between 0 and 4.

The present inventors have newly synthesized a compound represented by Formula 1, and according to the novel structure described above, the compound of Formula 1 has high fluorescence efficiency, excellent light resistance, or can implement improved luminance and color gamut, The invention was completed after confirming through experiments that high refractive index modulation can be achieved in holographic media.

More specifically, the compound of Formula 1 can be used as a dye in a photopolymer composition that provides a hologram recording medium.

In Formula 1, R ₁ to R ₅ are the same or different from each other, and each independently represents hydrogen, deuterium, halogen group, nitrile group, nitro group, hydroxy group, carboxyl group, alkyl group of 1 to 20 carbon atoms, and cycloalkyl group of 4 to 20 carbon atoms. , alkoxy group of 1 to 20 carbon atoms, aryloxy group of 6 to 20 carbon atoms, alkylthoxy group of 1 to 20 carbon atoms, arylthoxy group of 6 to 20 carbon atoms, alkylsulfoxy group of 1 to 20 carbon atoms, 6 to 20 carbon atoms An arylsulfoxy group, an alkenyl group having 2 to 20 carbon atoms, an amine group, an aryl group having 6 to 20 carbon atoms, -Y-(CH ₂ )pO-Ar ₁ , or a monovalent functional group derived from a heterocyclic aromatic compound, and the R ₁ to At least one of R ₅ is -Y-(CH ₂ )pO-Ar ₁ or a monovalent functional group derived from a heterocyclic aromatic compound, Y is an ether group or an ester group, p is an integer of 1 or more, and Ar ₁ is a carbon number It may be three or more aromatic compounds.

As the compound represented by Formula 1 contains at least one -Y-(CH ₂ )pO-Ar ₁ or a monovalent functional group derived from a heterocyclic aromatic compound as a substituent, it has high fluorescence efficiency, excellent light resistance, or improved luminance. and color gamut, or high refractive index modulation in holographic media.

The aromatic compound may include an arene compound containing one or more benzene rings, or a heteroarene compound in which carbon atoms in the arene compound are replaced with heteroatoms.

In addition, the heterocyclic aromatic compound may mean an aromatic compound containing one or more heteroatoms selected from N, O, S, Se, and Si.

The monovalent functional group derived from the heterocyclic aromatic compound may mean a monovalent functional group including the heterocyclic aromatic compound and may be substituted or unsubstituted.

More specifically, the monovalent functional groups derived from the heterocyclic aromatic compound include thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, and pyrimi group. Dil group, triazine group, triazole group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, coumarinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothio pen group, benzofuranyl group, benzo Triazole group, phenanthroline group, thiazolyl group, isoxazolyl group, oxadiazolyl group, thiadiazolyl group, benzothiazolyl group, phenothiazinyl group, and dibenzofuranyl group, etc., but is limited to these. It doesn't work. As described above, the monovalent functional group derived from the heterocyclic aromatic compound may be substituted or unsubstituted.

Specifically, Ar ₁ is a multi-ring aromatic compound having 3 or more carbon atoms, and the monovalent functional group derived from the heterocyclic aromatic compound may include a monovalent functional group derived from a heteromulti-ring aromatic compound having 3 or more carbon atoms.

Ar ₁ is a multi-ring aromatic compound having 3 or more carbon atoms, and the monovalent functional group derived from the hetero-ring aromatic compound includes a monovalent functional group derived from the hetero-multi-ring aromatic compound having 3 or more carbon atoms. Therefore, the compound represented by Formula 1 is a multi-ring aromatic compound. It may contain a substituent derived from an aromatic compound or a hetero multi-ring aromatic compound.

As the compound represented by Formula 1 contains a substituent derived from a multi-ring aromatic compound or a hetero-multi-ring aromatic compound, it can have high fluorescence efficiency, excellent light resistance, improve luminance and color gamut, or be used in holographic media. High refractive index modulation can be implemented.

For example, the monovalent functional group derived from the hetero multi-ring aromatic compound may mean -Ar ₂ , and Ar ₂ may be a hetero multi-ring aromatic compound. That is, the monovalent functional group derived from the hetero multicyclic aromatic compound may mean a monovalent functional group in which substituted or unsubstituted hetero multicyclic aromatic compounds are directly linked by a bond.

More specifically, Ar ₁ and the monovalent functional group derived from the heterocyclic aromatic compound may include a monovalent functional group derived from a heteromulticyclic aromatic compound having 3 or more carbon atoms.

That is, in Formula 1, at least one of R ₁ to R ₅ is a monovalent functional group derived from a heterocyclic aromatic compound linked by a linking group of -Y-(CH ₂ )pO- or a monovalent functional group derived from a heterocyclic aromatic compound linked by a direct bond. It may contain a functional group.

As the compound represented by Formula 1 contains a monovalent functional group derived from a heterocyclic aromatic compound linked by a linking group of -Y-(CH ₂ )pO- or a monovalent functional group derived from a heterocyclic aromatic compound linked by a direct bond, a high It can have fluorescence efficiency or excellent light resistance, can achieve improved luminance and color gamut, or can implement high refractive index modulation in holographic media.

Additionally, at least one of R ₁ to R ₅ may be a monovalent functional group derived from a heterocyclic aromatic compound, and the other may be a hydroxy group.

When at least one of R ₁ to R ₅ is a monovalent functional group derived from a heterocyclic aromatic compound and the other is a hydroxy group, the monovalent functional group derived from the heterocyclic aromatic compound and the hydroxy group may each be bonded to adjacent carbons. As the monovalent functional group derived from the heterocyclic aromatic compound and the hydroxy group each bond to adjacent carbons, the hetero element contained in the heterocyclic aromatic compound and the hydrogen of the hydroxy group may form a hydrogen bond.

For example, when the monovalent functional group derived from the heterocyclic aromatic compound is a monovalent functional group derived from an aromatic compound containing an N atom, the nitrogen contained in the heterocyclic aromatic compound and the hydrogen of the hydroxy group may form a hydrogen bond. there is.

In Formula 1, R ₆ to R ₉ are the same or different from each other, and each independently represents hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, and a cycloalkyl carboxylic acid group with 4 to 20 carbon atoms. It is a boxylate group or _an aryl carboxylate group having 6 to 20 carbon atoms, and X ₁ and

Specifically, R ₆ and R ₇ are the same or different from each other, and each independently represents an alkyl carboxylate group having 1 to 20 carbon atoms, a cycloalkyl carboxylate group having 4 to 20 carbon atoms, or an aryl carboxylate group having 6 to 20 carbon atoms. group, and R ₈ and R ₉ are the same or different from each other, and are each independently hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, and a cycloalkyl carboxyl group with 4 to 20 carbon atoms. It is a late group or an aryl carboxylate group having 6 to 20 carbon atoms, and X ₁ and X ₂ may be a halogen group.

The compound represented by Formula 1 may include a compound represented by Formula 1-1 or a compound represented by Formula 1-2.

[Formula 1-1]

In Formula 1-1, Y is an ether group or an ester group, p is an integer of 1 or more, Ar ₁ is an aromatic compound having 3 or more carbon atoms, R ₈ and R ₉ are the same or different from each other, and each independently represents hydrogen or halogen. group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, a cycloalkyl carboxylate group with 4 to 20 carbon atoms, or an aryl carboxylate group with 6 to 20 carbon atoms, and m and n are the same. or different, each independently _an integer from ₀ to 4, X _{1 and} The same or different, each independently an alkyl group with 1 to 19 carbon atoms, a cycloalkyl group with 4 to 19 carbon atoms, or an aryl group with 6 to 19 carbon atoms,

[Formula 1-2]

In Formula 1-2, one of R ₁₁ and R ₁₂ is a monovalent functional group derived from a heterocyclic aromatic compound, the other is a hydroxy group, R ₈ and R ₉ are the same as or different from each other, and each independently represents hydrogen or halogen. group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, a cycloalkyl carboxylate group with 4 to 20 carbon atoms, or an aryl carboxylate group with 6 to 20 carbon atoms, and m and n are the same. or different, each independently _an integer from ₀ to 4, X _{1 and} The same or different, each independently an alkyl group with 1 to 19 carbon atoms, a cycloalkyl group with 4 to 19 carbon atoms, or an aryl group with 6 to 19 carbon atoms.

For example, the compound represented by Formula 1 may include a compound represented by Formula 1-3 or a compound represented by Formula 1-4.

[Formula 1-3]

[Formula 1-4]

.

.

Meanwhile, according to another embodiment of the invention, a polymer matrix or a precursor thereof; A dye containing a compound represented by Formula 1 above; Photoreactive monomer; A photopolymer composition containing a photoinitiator may be provided.

As described above, the present inventors have newly synthesized a compound represented by Formula 1, and when the compound represented by Formula 1 is used as a dye in a photopolymer composition that provides a hologram recording medium, it has a high The invention was completed after confirming through experiments that refractive index modulation value and high diffraction efficiency could be achieved.

In general, methods such as making certain changes to the polymer matrix or recording monomer used or using specific additives to increase the refractive index modulation value and diffraction efficiency in photopolymer compositions that provide hologram recording media are known. However, methods such as using specific additives are known. The compound represented by can more easily improve the refractive index modulation value and diffraction efficiency even by applying a not very high amount.

Information regarding the compound represented by Formula 1 includes all of the above-mentioned information.

Meanwhile, the polymer matrix or its precursor may serve as a support for the holographic recording medium and the final product manufactured therefrom, and the photoreactive monomer may serve as a recording monomer, and depending on their use, holographic recording may be performed. When the photoreactive monomer is selectively polymerized on the polymer matrix, refractive index modulation may occur due to portions with different refractive indices.

The polymer matrix or its precursor is a compound commonly used in photopolymer compositions that provide hologram recording media and can be used without major limitations.

Specific examples of the polymer matrix or its precursor include 1) a reaction product between a compound containing at least one isocyanate group and a polyol; Or 2) it may include a polymer matrix containing a (meth)acrylate-based (co)polymer in which the silane-based functional group is located in the branch chain and a silane crosslinking agent.

A hologram formed from a photopolymer composition containing a polymer matrix or a precursor thereof containing a (meth)acrylate-based (co)polymer in which the silane-based functional group is located in the branch chain and a silane crosslinker is a previously known hologram even in a thinner thickness range. Compared to , it is possible to achieve greatly improved refractive index modulation value and excellent durability against temperature and humidity.

As a polymer matrix containing the silane crosslinking agent and a (meth)acrylate-based (co)polymer in which the silane-based functional group is located in the branch chain or a precursor thereof is used, the crosslinking density is increased when producing a coating film or hologram from the photopolymer composition. has been optimized to ensure excellent durability against temperature and humidity compared to existing matrices. In addition, through the optimization of the crosslinking density described above, recording characteristics can be improved by maximizing refractive index modulation by increasing the mobility between the photoreactive monomer with a high refractive index and the component with a low refractive index.

In particular, a cross-linking structure mediated by siloxane bonds can be easily introduced through a sol-gel reaction between a modified (meth)acrylate-based (co)polymer containing a silane-based functional group and a silane cross-linker containing a terminal silane-based functional group. , Excellent durability against temperature and humidity can be secured through this siloxane bond.

On the polymer matrix, the (meth)acrylate-based (co)polymer and the silane cross-linking agent, in which the above-mentioned silane-based functional group is located in the branch chain, may each exist as separate components, and may also exist in the form of a complex formed by reacting with each other. It can exist.

In the (meth)acrylate-based (co)polymer, the silane-based functional group may be located in the branch chain. The silane-based functional group may include a silane functional group or an alkoxy silane functional group. Preferably, a trimethoxysilane group may be used as the alkoxy silane functional group.

The silane-based functional group may form a siloxane bond through a sol-gel reaction with the silane-based functional group included in the silane crosslinking agent, thereby crosslinking the (meth)acrylate-based (co)polymer and the silane crosslinking agent.

The silane crosslinking agent may be a compound or a mixture thereof having an average of one or more silane-based functional groups per molecule, and may be a compound containing one or more silane-based functional groups. The silane-based functional group may include a silane functional group or an alkoxy silane functional group. Preferably, a triethoxysilane group may be used as the alkoxy silane functional group. The silane-based functional group can form a siloxane bond through a sol-gel reaction with the silane-based functional group contained in the (meth)acrylate-based (co)polymer, thereby crosslinking the (meth)acrylate-based (co)polymer and the silane crosslinking agent. there is.

At this time, the silane crosslinking agent may have an equivalent weight of the silane-based functional group of 200 g/equivalent to 1000 g/equivalent. Accordingly, the crosslinking density between the (meth)acrylate-based (co)polymer and the silane crosslinking agent is optimized, ensuring excellent durability against temperature and humidity compared to the existing matrix. In addition, through the optimization of the crosslinking density described above, recording characteristics can be improved by maximizing refractive index modulation by increasing the mobility between the photoreactive monomer with a high refractive index and the component with a low refractive index.

If the equivalent weight of the silane-based functional group contained in the silane crosslinking agent is excessively increased to 1000 g/equivalent or more, the diffraction grating interface after recording may collapse due to a decrease in the crosslinking density of the matrix, resulting in a loose crosslinking density and a low glass transition temperature. As a result, monomers and plasticizer components may be eluted to the surface and generate haze. If the equivalent weight of the silane-based functional group contained in the silane crosslinking agent is excessively reduced to less than 200 g/equivalent, the crosslinking density becomes too high, impeding the fluidity of the monomer and plasticizer components, and resulting in a problem of significantly lowering the recording characteristics. You can.

More specifically, the silane crosslinking agent includes a linear polyether main chain having a weight average molecular weight of 100 g/mol to 2000 g/mol, or 300 g/mol to 1000 g/mol, or 300 g/mol to 700 g/mol, and It may include a silane-based functional group bound to the terminal or branch chain of the main chain.

The linear polyether main chain having a weight average molecular weight of 100 g/mol to 2000 g/mol may include a repeating unit represented by the following formula (3).

[Formula 3]

-(R ₃₀ O) _q -R ₃₀ -

In Formula 3, R ₃₀ is an alkylene group having 1 to 10 carbon atoms, and q is an integer of 1 or more, or 1 to 50, or 5 to 20, or 8 to 10.

The silane crosslinking agent can improve the fluidity of components by controlling the glass transition temperature and crosslinking density of the matrix by introducing flexible polyether polyol into the main chain.

Meanwhile, the bond between the silane-based functional group and the polyether main chain may be mediated through a urethane bond. Specifically, the silane-based functional group and the polyether main chain may form a bond with each other through a urethane bond, and more specifically, the silicon atom included in the silane-based functional group is directly connected to the nitrogen atom of the urethane bond or has 1 to 10 carbon atoms. It bonds through an alkylene group, and the R ₃₀ functional group included in the polyether main chain can directly bond with the oxygen atom of the urethane bond.

In this way, the silane-based functional group and the polyether main chain are bonded through a urethane bond, and the silane crosslinking agent is an isocyanate compound containing a silane-based functional group and a linear polyether polyol with a weight average molecular weight of 100 g/mol to 2000 g/mol. This is because it is a reaction product manufactured through a reaction between compounds.

More specifically, the isocyanate compound is aliphatic, cycloaliphatic, aromatic or araliphatic mono-isocyanate, di-isocyanate, tri-isocyanate or poly-isocyanate; or oligo-isocyanates of di-isocyanates or triisocyanates having the structure of urethane, urea, carbodiimide, acylurea, isocyanurate, allophanate, biuret, oxadiazinetrione, uretdione or iminooxadiazinedione. or poly-isocyanate; may be included.

Specific examples of the isocyanate compound containing the silane-based functional group include 3-isocyanatopropyltriethoxysilane.

In addition, the polyether polyol includes, for example, polyaddition products of styrene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, and epichlorohydrin, mixed adducts and graft products thereof, and polyether polyols obtained by condensation of polyhydric alcohols or mixtures thereof, and those obtained by alkoxylation of polyhydric alcohols, amines and amino alcohols.

Specific examples of the polyether polyol include an OH functionality of 1.5 to 6 and a number average molecular weight between 200 and 18000 g/mol, preferably an OH functionality of 1.8 to 4.0 and a number average molecular weight of 600 to 8000 g/mol, Particularly preferred are poly(propylene oxide), poly(ethylene oxide) and combinations thereof in the form of random or block copolymers, having an OH functionality of 1.9 to 3.1 and a number average molecular weight of 650 to 4500 g/mol, or poly(tetrahydrofuran) and mixtures thereof.

In this way, when the silane-based functional group and the polyether main chain are combined through a urethane bond, a silane crosslinking agent can be synthesized more easily.

The weight average molecular weight (GPC measurement) of the silane crosslinking agent may be 1000 g/mol to 5,000,000 g/mol. The weight average molecular weight means the weight average molecular weight (unit: g/mol) in terms of polystyrene measured by GPC method. In the process of measuring the weight average molecular weight of polystyrene equivalent measured by the GPC method, commonly known analysis devices, detectors such as differential refractive index detectors, and analytical columns can be used, and the commonly applied temperature Conditions, solvent, and flow rate can be applied. Specific examples of the measurement conditions include a temperature of 30° C., chloroform solvent, and a flow rate of 1 mL/min.

Meanwhile, the (meth)acrylate-based (co)polymer may include a (meth)acrylate repeating unit and a (meth)acrylate repeating unit in which the silane-based functional group is located in the branch chain.

An example of a (meth)acrylate repeating unit in which a silane-based functional group is located in a branch chain may include a repeating unit represented by the following formula (4).

[Formula 4]

In Formula 4, R ₁ to R ₃ are each independently an alkyl group having 1 to 10 carbon atoms, R ₄ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ₅ is an alkylene group having 1 to 10 carbon atoms.

Preferably, in Formula 4, R ₁ to R ₃ are each independently a methyl group having 1 carbon atom, R ₄ is a methyl group having 1 carbon atom, and R ₅ is a propylene group having 3 carbon atom, derived from 3-Methacryloxypropyltrimethoxysilane (KBM-503) The repeating unit or R ₁ to R ₃ may each independently be a methyl group having 1 carbon number, R ₄ is hydrogen, and R ₅ is a propylene group having 3 carbon atoms, a repeating unit derived from 3-Acryloxypropyltrimethoxysilane (KBM-5103).

Additionally, examples of the (meth)acrylate repeating unit include a repeating unit represented by the following formula (5).

[Formula 5]

In Formula 5, R ₆ is an alkyl group having 1 to 20 carbon atoms, R ₇ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and preferably, in Formula 2, R ₆ is a butyl group having 4 carbon atoms, and R ₇ is It may be a repeating unit derived from hydrogen or butyl acrylate.

The molar ratio between the repeating unit of Formula 5 and the repeating unit of Formula 4 may be 0.5:1 to 14:1. If the molar ratio of the repeating unit of Formula 4 is excessively reduced, the cross-linking density of the matrix becomes too low and cannot serve as a support, which may lead to a decrease in recording characteristics after recording. If the molar ratio of the repeating unit of Formula 4 is excessively low, the matrix cannot function as a support. If it increases, the crosslinking density of the matrix becomes too high and the fluidity of each component decreases, which may cause a decrease in the refractive index modulation value.

The weight average molecular weight (GPC measurement) of the (meth)acrylate-based (co)polymer may be 100,000 g/mol to 5,000,000 g/mol, or 300,000 g/mol to 900,000 g/mol. The weight average molecular weight means the weight average molecular weight (unit: g/mol) in terms of polystyrene measured by GPC method. In the process of measuring the weight average molecular weight of polystyrene equivalent measured by the GPC method, commonly known analysis devices, detectors such as differential refractive index detectors, and analytical columns can be used, and the commonly applied temperature Conditions, solvent, and flow rate can be applied. Specific examples of the measurement conditions include a temperature of 30° C., chloroform solvent, and a flow rate of 1 mL/min.

Meanwhile, the (meth)acrylate-based (co)polymer has an equivalent weight of the silane-based functional group of 300 g/equivalent to 2000 g/equivalent, or 500 g/equivalent to 2000 g/equivalent, or 550 g/equivalent to 1800 g. /equivalent, or 580 g/equivalent to 1600 g/equivalent, or 586 g/equivalent to 1562 g/equivalent.

The silane-based functional group equivalent is the equivalent weight (g/equivalent) for one silane-based functional group, and is the weight average molecular weight of the (meth)acrylate-based (co)polymer divided by the number of silane-based functional groups per molecule. The smaller the equivalent value, the higher the density of functional groups, and the larger the equivalent value, the smaller the functional group density.

Accordingly, the crosslinking density between the (meth)acrylate-based (co)polymer and the silane crosslinking agent is optimized, ensuring excellent durability against temperature and humidity compared to the existing matrix. In addition, through the optimization of the crosslinking density described above, recording characteristics can be improved by maximizing refractive index modulation by increasing the mobility between the photoreactive monomer with a high refractive index and the component with a low refractive index.

If the equivalent weight of the silane-based functional group contained in the (meth)acrylate-based (co)polymer is excessively reduced to less than 300 g/equivalent, the crosslinking density of the matrix becomes too high, impairing the fluidity of the components, thereby impairing the recording characteristics. A decrease may occur. In addition, if the equivalent weight of the silane-based functional group contained in the (meth)acrylate-based (co)polymer is excessively increased to more than 2000 g/equivalent, the crosslinking density is so low that it cannot serve as a support, resulting in The boundaries of the diffraction gratings may collapse and the refractive index modulation value may decrease over time.

Meanwhile, based on 100 parts by weight of the (meth)acrylate-based (co)polymer, the silane crosslinker content may be 10 parts by weight to 90 parts by weight, or 20 parts by weight to 70 parts by weight, or 22 parts by weight to 65 parts by weight. there is.

In the reaction product, if the silane crosslinker content is excessively reduced relative to 100 parts by weight of the (meth)acrylate-based (co)polymer, the curing speed of the matrix is significantly slowed, losing its function as a support, and the diffraction grating boundary surface after recording. This can easily collapse, and in the reaction product, if the silane crosslinker content is excessively increased relative to 100 parts by weight of the (meth)acrylate-based (co)polymer, the curing speed of the matrix becomes faster, but the reactive silane group content decreases. Excessive increase causes compatibility problems with other ingredients and causes haze.

Additionally, the modulus (storage modulus) of the reaction product may be 0.01 MPa to 5 MPa. As a specific example of the modulus measurement method, the storage modulus (G') value can be measured at a frequency of 1 Hz at room temperature (20 ℃ to 25 ℃) using TA Instruments' DHR (discovery hybrid rheometer) equipment.

Additionally, the glass transition temperature of the reaction product may be -40°C to 10°C. As a specific example of the glass transition temperature measurement method, a photopolymerization composition is coated in the range of -80 ℃ to 30 ℃ under the setting conditions of strain 0.1%, frequency 1 Hz, and temperature increase rate of 5 ℃/min using DMA (dynamic mechanical analysis) measuring equipment. One method is to measure the change in phase angle (loss modulus) of the film.

Another example of the polymer matrix or its precursor may be a polymer matrix containing a reaction product between a compound containing at least one isocyanate group and a polyol.

The compound containing one or more isocyanate groups may be a known compound or a mixture thereof having an average of one or more NCO functional groups per molecule, and may be a compound containing one or more isocyanate groups.

More specifically, the compound containing one or more isocyanate groups is an aliphatic, cycloaliphatic, aromatic or araliphatic mono-di-, tri- or poly-isocyanate. In addition, the compound containing one or more isocyanate groups is a monomer having a urethane, urea, carbodiimide, acylurea, isocyanurate, allophanate, biuret, oxadiazinetrione, urethedione, or iminooxadiazinedione structure. It can be a relatively high molecular weight secondary product of type di- and/or triisocyanate (oligo- and polyisocyanate).

Specific examples of compounds containing one or more isocyanate groups include butylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 1,8-diisocyanato-4-(isocyanatomethyl )octane, 2,2,4- and/or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis(4,4'-isocyanatocyclohexyl)methane and its having any desired isomer content Mixture, isocyanatomethyl-1,8-octane diisocyanate, 1,4-cyclohexylene diisocyanate, isomeric cyclohexanedimethylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and/or 2,6-toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,4'- or 4,4'-diphenylmethane diisocyanate and/or triphenylmethane 4,4',4"-triisocyanate, etc. can be mentioned.

The polyol that reacts with the compound containing one or more isocyanate groups to form a polymer matrix may be an aliphatic, araliphatic, or cycloaliphatic diol, triol, and/or higher polyol having 2 to 20 carbon atoms.

The polyol may have a hydroxyl equivalent weight of 300 g/mol to 10,000 g/mol and a weight average molecular weight of 100,000 g/mol to 1,500,0000 g/mol.

Examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl. Glycol, 2-ethyl-2-butylpropanediol, trimethylpentanediol, diethyloctanediol positional isomer, 1,3-butylene glycol, cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol , 1,2- and 1,4-cyclohexanediol, hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), 2,2-dimethyl-3-hydroxypropyl, 2,2- There is dimethyl-3-hydroxypropionate.

Additionally, examples of the triol include trimethylolethane, trimethylolpropane, or glycerol. Suitable high-functional alcohols are ditrimethylolpropane, pentaerythritol, dipentaerythritol or sorbitol.

In addition, the polyols include aliphatic and cycloaliphatic polyols of relatively high molecular weight, such as polyester polyol, polyether polyol, polycarbonate polyol, hydroxy-functional acrylic resin, hydroxy-functional polyurethane, hydroxy- Functional epoxy resin, etc. can be used.

The polyester polyol is for example ethanediol, di-, tri- or tetraethylene glycol, 1,2-propanediol, di-, tri- or tetrapropylene glycol, 1,3-propanediol, 1,4-butanediol , 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-dihydroxycyclohexane, Polyhydric alcohols such as 1,4-dimethylolcyclohexane, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol or mixtures thereof are used, and optionally trimethylolpropane or glycerol. Polyols of higher functionality can be used simultaneously, for example succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, terephthalic acid. aliphatic, cycloaliphatic or aromatic, such as isophthalic acid, o-phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid or trimellitic acid, and acid anhydrides such as o-phthalic anhydride, trimellitic anhydride or succinic anhydride, or mixtures thereof. linear polyester diols, such as those which can be prepared in a known manner from di- or polycarboxylic acids or anhydrides thereof. Of course, cycloaliphatic and/or aromatic di- and polyhydroxy compounds are also suitable as polyhydric alcohols for the production of polyester polyols. Instead of free polycarboxylic acids, it is also possible to use corresponding polycarboxylic acid anhydrides of lower alcohols or corresponding polycarboxylates, or mixtures thereof, in the preparation of polyesters.

In addition, polyester polyols that can be used in the synthesis of the polymer matrix include homo- or copolymers of lactones, preferably lactones such as butyrolactone, ε-caprolactone and/or methyl-ε-caprolactone. or by addition reaction of lactone mixtures with suitable difunctional and/or higher functional initiator molecules, such as the polyhydric alcohols of small molecular weight mentioned above, for example as synthetic components for polyester polyols.

In addition, polycarbonates with hydroxyl groups are also suitable as polyhydroxy components for the synthesis of prepolymers, for example diols such as 1,4-butanediol and/or 1,6-hexanediol and/or 3-methyl These can be prepared by reaction of pentanediol with diaryl carbonates such as diphenyl carbonate, dimethyl carbonate or phosgene.

In addition, polyether polyols that can be used in the synthesis of the polymer matrix include, for example, polyaddition products of styrene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, and epichlorohydrin, and their mixed adducts and graft products, and polyether polyols and polyhydric alcohols obtained by condensation of polyhydric alcohols or mixtures thereof, and those obtained by alkoxylation of amines and amino alcohols. Specific examples of the polyether polyol include an OH functionality of 1.5 to 6 and a number average molecular weight between 200 and 18000 g/mol, preferably an OH functionality of 1.8 to 4.0 and a number average molecular weight of 600 to 8000 g/mol, Particularly preferred are poly(propylene oxide), poly(ethylene oxide) and combinations thereof in the form of random or block copolymers, having an OH functionality of 1.9 to 3.1 and a number average molecular weight of 650 to 4500 g/mol, or poly(tetrahydrofuran) and mixtures thereof.

Meanwhile, the photoreactive monomer may include a polyfunctional (meth)acrylate monomer or a monofunctional (meth)acrylate monomer.

As described above, during the photopolymerization process of the photopolymer composition, monomers are polymerized and the refractive index increases in areas where there is a relatively large amount of polymer, and the refractive index is relatively low in areas where there is a relatively large amount of polymer binder, resulting in refractive index modulation. , a diffraction grating is created by this refractive index modulation.

Specifically, an example of the photoreactive monomer is a (meth)acrylate-based α,β-unsaturated carboxylic acid derivative, such as (meth)acrylate, (meth)acrylamide, (meth)acrylonitrile, or (meth)acrylonitrile. Examples include acrylic acid, etc., or compounds containing a vinyl group or thiol group.

An example of the photoreactive monomer may be a polyfunctional (meth)acrylate monomer having a refractive index of 1.5 or more, or 1.53 or more, or 1.5 to 1.7, and the refractive index may be 1.5 or more, or 1.53 or more, or 1.5 to 1.7. The functional (meth)acrylate monomer may contain a halogen atom (bromine, iodine, etc.), sulfur (S), phosphorus (P), or an aromatic ring.

More specific examples of the polyfunctional (meth)acrylate monomer with a refractive index of 1.5 or more include bisphenol A modified diacrylate series, fluorene acrylate series (HR6022, etc. - Miwon), and bisphenol fluorene epoxy acrylate series (HR6100, HR6060, HR6042, etc. - Miwon). ), halogenated epoxy acrylate series (HR1139, HR3362, etc. - Miwon), etc.

Another example of the photoreactive monomer may be a monofunctional (meth)acrylate monomer. The monofunctional (meth)acrylate monomer may contain an ether bond and a fluorene functional group inside the molecule, and specific examples of such monofunctional (meth)acrylate monomer include phenoxy benzyl (meth)acrylate, o-phenyl. Examples include phenol ethylene oxide (meth)acrylate, benzyl (meth)acrylate, 2-(phenylthio)ethyl (meth)acrylate, or biphenylmethyl (meth)acrylate.

Meanwhile, the photoreactive monomer may have a weight average molecular weight of 50 g/mol to 1000 g/mol, or 200 g/mol to 600 g/mol. The weight average molecular weight refers to the weight average molecular weight in terms of polystyrene measured by GPC method.

Meanwhile, the hologram recording medium of the above embodiment may further include a photoinitiator. The photoinitiator is a compound that is activated by light or actinic radiation and initiates the polymerization of a compound containing a photoreactive functional group such as the photoreactive monomer.

As the photoinitiator, commonly known photoinitiators can be used without significant limitations, but specific examples thereof include radical photopolymerization initiators, photocationic polymerization initiators, or photoanionic polymerization initiators.

Specific examples of the photo radical polymerization initiator include imidazole derivatives, bisimidazole derivatives, N-aryl glycine derivatives, organic azide compounds, titanocene, aluminate complexes, organic peroxides, N-alkoxy pyridinium salts, and thioxanthone. Derivatives, amine derivatives, etc. can be mentioned. More specifically, the photo radical polymerization initiator includes 1,3-di(t-butyldioxycarbonyl)benzophenone, 3,3',4,4''-tetrakis(t-butyldioxycarbonyl)benzophenone, 3-phenyl-5-isoxazolone, 2-mercapto benzimidazole, bis(2,4,5-triphenyl)imidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one (Product name: Irgacure 651 / Manufacturer: BASF), 1-hydroxy-cyclohexyl-phenyl -ketone (product name: Irgacure 184 / manufacturer: BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (product name: Irgacure 369 / manufacturer: BASF), and bis(5-2, 4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium (Product name: Irgacure 784 Manufacturer: BASF), Ebecryl P-115 (Manufacturer: SK entis), etc.

Examples of the photocationic polymerization initiator include diazonium salt, sulfonium salt, or iodonium salt, such as sulfonic acid ester, imide sulfonate, and dialkyl-4. -hydroxy sulfonium salt, aryl sulfonic acid-p-nitrobenzyl ester, silanol-aluminum complex, (η6-benzene)(η5-cyclopentadienyl)iron (II), etc. Additionally, benzoin tosylate, 2,5-dinitro benzyl tosylate, N-tosylphthalic acid imide, etc. are also included. More specific examples of the photocationic polymerization initiator include Cyracure UVI-6970, Cyracure UVI-6974 and Cyracure UVI-6990 (manufacturer: Dow Chemical Co. in USA), Irgacure 264 and Irgacure 250 (manufacturer: BASF), or CIT-1682. (Manufacturer: Nippon Soda) and other commercially available products.

Examples of the photoanionic polymerization initiator include borate salt, for example, butyryl chlorine butyltriphenylborate (BUTYRYL CHOLINE BUTYLTRIPHENYLBORATE). More specific examples of the photoanionic polymerization initiator include commercially available products such as Borate V (manufacturer: Spectra group).

Additionally, the photopolymer composition of the above embodiment may use a monomolecular (Type I) or bimolecular (Type II) initiator. (Type I) systems for free radical photopolymerization include, for example, aromatic ketone compounds in combination with tertiary amines, such as benzophenones, alkylbenzophenones, 4,4'-bis(dimethylamino)benzophenone (Michler's ) ketones), anthrones and halogenated benzophenones or mixtures of the above types. The bimolecular (Type II) initiators include benzoin and its derivatives, benzyl ketals, acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bisacylophosphine oxide, phenylgly Oxyl esters, camphorquinone, alpha-aminoalkylphenone, alpha-,alpha-dialkoxyacetophenone, 1-[4-(phenylthio)phenyl]octane-1,2-dione 2-(O-benzoyloxime) and alpha -Hydroxyalkylphenone, etc. can be mentioned.

The photopolymer composition of the above embodiment includes 1% to 80% by weight of the polymer matrix or its precursor based on the total weight of the photopolymer composition; 1% to 80% by weight of the photoreactive monomer; 0.0001% to 10% by weight of the dye; and 0.1% to 20% by weight of photoinitiator. As described later, when the photopolymer composition further includes an organic solvent, the content of the above-mentioned components is based on the total of these components (total of components excluding the organic solvent).

Meanwhile, the hologram recording medium may further include at least one selected from the group consisting of a catalyst, a phosphate-based compound, and a low-refractive-index fluorine-based compound.

The phosphate-based compound and the low-refractive-index fluorine-based compound have a lower refractive index than the photoreactive monomer, and can maximize the refractive index modulation of the photopolymer composition by lowering the refractive index of the polymer matrix. Moreover, the phosphate-based compound acts as a plasticizer, lowering the glass transition temperature of the polymer matrix to increase the mobility of photoreactive monomers and low-refractive components, and can also contribute to improving the moldability of the photopolymer composition.

More specifically, the low refractive index fluorine-based compound is Since it has stability with little reactivity and a low refractive index, when added to the photopolymer composition, the refractive index of the polymer matrix can be lowered, thereby maximizing refractive index modulation with the monomer.

The fluorine-based compound may include at least one functional group selected from the group consisting of an ether group, an ester group, and an amide group, and at least two difluoromethylene groups. More specifically, the fluorine-based compound may have a structure represented by the following formula (6) in which a functional group including an ether group is bonded to both ends of a central functional group including a direct bond or an ether bond between two difluoromethylene groups.

[Formula 6]

In Formula 6, R ₁₁ and R ₁₂ are each independently a difluoromethylene group, R ₁₃ and R ₁₆ are each independently a methylene group, R ₁₄ and R ₁₅ are each independently a difluoromethylene group, R ₁₇ and R ₁₈ are each independently a polyalkylene oxide group, and m is an integer of 1 or more, or 1 to 10, or 1 to 3.

Preferably, in Formula 6, R ₁₁ and R ₁₂ are each independently a difluoromethylene group, R ₁₃ and R ₁₆ are each independently a methylene group, and R ₁₄ and R ₁₅ are each independently a difluoromethylene group. group, R ₁₇ and R ₁₈ are each independently a 2-methoxyethoxymethoxy group, and m is an integer of 2.

The fluorine-based compound may have a refractive index of less than 1.45, or more than 1.3 and less than 1.45. As described above, since the photoreactive monomer has a refractive index of 1.5 or more, the fluorine-based compound has a lower refractive index than the photoreactive monomer, thereby lowering the refractive index of the polymer matrix, thereby maximizing refractive index modulation with the monomer.

Specifically, the fluorine-based compound content may be 30 to 150 parts by weight, or 50 to 110 parts by weight, based on 100 parts by weight of the photoreactive monomer.

If the fluorine-based compound content is excessively reduced relative to 100 parts by weight of the photoreactive monomer, the refractive index modulation value after recording is lowered due to a lack of low-refractive components, and the fluorine-based compound content is excessively increased relative to 100 parts by weight of the photoreactive monomer. If this happens, haze may occur due to compatibility issues with other ingredients, or some fluorine-based compounds may elute to the surface of the coating layer.

The fluorine-based compound may have a weight average molecular weight (GPC measurement) of 300 g/mol or more, or 300 g/mol to 1000 g/mol. The specific method of measuring weight average molecular weight is as described above.

Meanwhile, specific examples of the phosphate-based compounds include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, and tributyl phosphate.

The phosphate-based compound may be added with the above-mentioned fluorine-based compound at a weight ratio of 1:5 to 5:1. The phosphate-based compound may have a refractive index of less than 1.5 and a molecular weight of 700 g/mol or less.

The photopolymer composition may further include other additives, catalysts, etc. For example, the photopolymer composition may include a commonly known catalyst to promote polymerization of the polymer matrix or photoreactive monomer. Examples of the catalyst include tin octanoate, zinc octanoate, dibutyltin dilaurate, dimethylbis[(1-oxoneodecyl)oxy]stanane, dimethyltin dicarboxylate, and zirconium bis(ethylhexadecyl). noate), zirconium acetylacetonate, p-toluenesulfonic acid or tertiary amines such as 1,4-diazabicyclo[2.2.2]octane, diazabicyclononane, diazabicycloundecane , 1,1,3,3-tetramethylguanidine, 1,3,4,6,7,8-hexahydro-1-methyl-2H-pyrimido (1,2-a) pyrimidine, etc. .

Examples of the other additives include anti-foaming agents, and as the anti-foaming agents, silicone-based reactive additives can be used, and an example of this is Tego Rad 2500.

Meanwhile, the photopolymer composition of the above embodiment may further include a different photoreactive dye in addition to the compound represented by Formula 1 described above.

The photosensitive dye serves as a sensitizing dye that sensitizes the photoinitiator. More specifically, the photosensitive dye also acts as an initiator that initiates polymerization of monomers and crosslinking monomers by being stimulated by light irradiated on the photopolymer composition. can do.

Examples of photosensitive dyes different from the compound represented by Formula 1 are not greatly limited, and various commonly known compounds can be used. Specific examples of the photosensitive dye include sulfonium derivative of ceramidonin, new methylene blue, thioerythrosine triethylammonium, and 6-acetylamino-2-methylcera. 6-acetylamino-2-methylceramidonin, eosin, erythrosine, rose bengal, thionine, basic yellow, pinacyanol chloride ), rhodamine 6G, gallocyanine, ethyl violet, Victoria blue R, Celestine blue, Quinaldine Red, Crystal violet, brilliant green, Astrazon orange G, darrow red, pyronin Y, basic red 29, blood Examples include pyrylium iodide, Safranin O, cyanine, methylene blue, Azure A, or a combination of two or more thereof.

Meanwhile, organic solvents may be used when manufacturing the hologram recording medium. Non-limiting examples of the organic solvent include ketones, alcohols, acetates, and ethers, or mixtures of two or more thereof.

Specific examples of such organic solvents include ketones such as methyl ethyl canone, methyl isobutyl ketone, acetylacetone, and isobutyl ketone; Alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, or t-butanol; Acetates such as ethyl acetate, i-propyl acetate, or polyethylene glycol monomethyl ether acetate; ethers such as tetrahydrofuran or propylene glycol monomethyl ether; Or a mixture of two or more types thereof may be mentioned.

The organic solvent may be added at the time of mixing each component included in the photopolymer composition for manufacturing the hologram recording medium, or may be included in the photopolymer composition while each component is added in a dispersed or mixed state in the organic solvent. If the content of the organic solvent in the photopolymer composition is too small, the flowability of the photopolymer composition may decrease and defects such as streaks may occur in the final manufactured film. In addition, when an excessive amount of the organic solvent is added, the solid content is lowered, and coating and film formation are not sufficiently performed, which may deteriorate the physical properties or surface characteristics of the film, and defects may occur during drying and curing processes. Accordingly, the photopolymer composition may include an organic solvent so that the total solid concentration of the components included is 1% to 70% by weight, or 2% to 50% by weight.

Meanwhile, the hologram recording medium can implement a refractive index modulation value (n) of 0.020 or more, 0.021 or more, 0.022 or more, or 0.0225 to 0.035 even at a thickness of 5 μm to 30 μm.

Additionally, the hologram recording medium can achieve a diffraction efficiency of 50% or more, or 85% or more, or 85% to 99% at a thickness of 5 μm to 30 μm.

The photopolymer composition for producing the hologram recording medium is uniformly mixed with each component included, dried and cured at a temperature of 20° C. or higher, and then exposed to the entire visible range and near-ultraviolet range ( It can be produced as a hologram for optical applications in the wavelength range (300 to 800 nm).

The hologram formation process can be prepared by first mixing the components forming the polymer matrix or its precursor among the photopolymer composition homogeneously, and then mixing the above-mentioned silane crosslinking agent with the catalyst.

The photopolymer composition can use a commonly known mixer, stirrer, or mixer without any restrictions to mix each of the components contained therein, and the temperature during the mixing process is 0 ℃ to 100 ℃, preferably 10 ℃. to 80°C, particularly preferably 20°C to 60°C.

Meanwhile, the photopolymer composition may first be homogenized and mixed with components forming the polymer matrix or its precursor, and then cured at a temperature of 20° C. or higher to form a liquid formulation. The temperature of the curing may vary depending on the composition of the photopolymer and is accelerated, for example, by heating to a temperature of 30° C. to 180° C.

During the curing, the photopolymer may be injected or coated on a predetermined substrate or mold.

Meanwhile, as a method of recording a visual hologram on a hologram recording medium manufactured from the photopolymer composition, commonly known methods can be used without significant limitations, and the method described in the holographic recording method of the embodiment described later can be adopted as an example. You can.

Meanwhile, according to another embodiment of the invention, a holographic recording method may be provided, including the step of selectively polymerizing the photoreactive monomer included in the photopolymer composition by a coherent laser.

As described above, a medium in which no visual hologram is recorded can be manufactured through a process of mixing and curing the photopolymer composition, and a visual hologram can be recorded on the medium through a predetermined exposure process.

A visual hologram can be recorded on a medium provided through the process of mixing and curing the photopolymer composition using known devices and methods under commonly known conditions.

Meanwhile, according to another embodiment of the invention, an optical element including a hologram recording medium can be provided.

Specific examples of the optical elements include optical lenses, mirrors, deflecting mirrors, filters, diffusion screens, diffraction members, light guides, waveguides, holographic optical elements having the functions of projection screens and/or masks, media and light of optical memory systems. Examples include diffusion plates, optical wavelength splitters, reflective and transmissive color filters, etc.

An example of an optical element including the hologram recording medium may be a hologram display device.

The holographic display device includes a light source unit, an input unit, an optical system, and a display unit. The light source unit is a part that emits a laser beam used to provide, record, and reproduce 3D image information of an object from the input unit and the display unit. In addition, the input unit is a part that pre-inputs 3D image information of the object to be recorded on the display unit. For example, the input unit inputs 3D image information of the object, such as the intensity and phase of light for each space, into an electrically addressed liquid crystal SLM (SLM). Dimensional information can be input, and an input beam can be used in this case. The optical system may be composed of a mirror, polarizer, beam splitter, beam shutter, lens, etc., and the optical system may include an input beam that sends the laser beam emitted from the light source to the input unit, a recording beam that sends the laser beam to the display unit, a reference beam, an erase beam, and a reader. It can be distributed through chulbim, etc.

The display unit can receive 3D image information of an object from an input unit, record it on a hologram plate made of an optically driven SLM (optically addressed SLM), and reproduce the 3D image of the object. At this time, 3D image information of the object can be recorded through interference between the input beam and the reference beam. The 3D image information of the object recorded on the hologram plate can be reproduced as a 3D image by a diffraction pattern generated by the read beam, and an erase beam can be used to quickly remove the formed diffraction pattern. Meanwhile, the hologram plate can be moved between a position where a 3D image is input and a position where it is played.

According to the present invention, a dye compound, photopolymer composition, holographic recording medium, optical element, and holographic recording method can be provided that have a small thickness yet realize a large refractive index modulation value and have improved durability against temperature and humidity.

The invention is explained in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

[Manufacturing example]

Preparation Example 1: Synthesis of dye compound 1

A mixture of sodium hydride (NaH; 60% w/v oil, 4 g, 0.1018 mol), tetrahydrofuran (THF; 500 ml), and ethanol (EtOH, 1 ml) was cooled to 0 °C. Ethyl formate (11.3 g, 0.1528 mol) and cyclohexanone (compound 1, 10 g, 0.1018 mol) were added dropwise to the solution, and the reaction was stirred for 6 hours and stored at room temperature overnight.

Then, the solution that became clear by adding 500 ml of water was extracted three times with 100 ml of ethyl acetate. The aqueous layer was separated and acidified with high concentration hydrochloric acid (HCl) to pH ~ 1. Product 2 was extracted with ethyl acetate (100 ml × 2), the organic layer was separated, dried over magnesium sulfate (MgSO ₄ ), and concentrated in vacuo to obtain 11.6 g of product 2 in 90% yield.

Product 2 (11.6g, 0.0920 mol) was dissolved in 150ml of methanol, then glycine methyl ester hydrochloride (11.5g, 0.0920 mol) and triethylamine (trimethylamine; 12.8g, 0.0920mol) were added. After addition, the reaction was stirred at room temperature overnight and then concentrated in vacuo.

300ml of water was added to the concentrated reaction product, and the aqueous solution was extracted with chloroform (200ml x 2). The organic layer was separated, washed with 100 ml of brine, dried over magnesium sulfate, and concentrated to obtain 15.1 g of product 3 in 83% yield.

Product 3 (15.1 g, 0.0765 mol) was dissolved in 50 ml of methanol, then 30% sodium methoxide (NaOMe; 14.2 ml, 0.0765 mol) and 50 ml of methanol were added, and the mixture was reacted at 90°C for 3 hours. After the reaction was cooled to room temperature, the solution was diluted with 300 ml of water and extracted with ethyl acetate (100 ml x 3). The organic layer was dried over magnesium sulfate and concentrated in vacuo. The residue was purified by column chromatography (hexane / ethyl acetate (volume ratio) = 9 / 1) to obtain 4.5 g of product 4 in 33% yield.

1H NMR (CDCl ₃ ): 8.8 (1H, s, NH), 6.65 (1H, s, Ar), 3.83 (3H, s, CH ₃ ), 2.82-2.79 (2H, t, CH ₂ ), 2.56-2.53 (2H, t, CH ₂ ), 1.79-1.70 (4H, m, 2CH ₂ ).

Terephthalaldehydic acid (Compound 5; 1 g, 0.0066 mol) dissolved in 20ml dichloromethane, DCC (N,N'-Dicyclohexylcarbodiimide, 1.9g, 0.0093 mol) and DMAP (4-Dimethylaminopyridine, 0.08 mol) g, 0.0006 mol) was added at room temperature, 4-(3-hydroxypropoxy)-2H-chromen-2-one (0.22 g, 0.001 mol) was further added, and the mixture was stirred at room temperature overnight for reaction.

After filtering the precipitate and concentrating the filtrate in vacuo, the residue was stirred in 20ml ethanol for 30 minutes, filtered, and dried to obtain 2.0g product 6 in 88% yield.

1H NMR (CDCl ₃ ): 9.91 (s, 1H), 8.0-7.5 (m, 8H), 5.5 (s, 1H), 4.4 (t, 2H), 4.1 (t, 2H), 2.4 (m, 2H)

To the above synthesized product 4 (1.7g, 0.0095 mol) dissolved in 30 ml dichloromethane, toluene sulfonic acid monohydride (0.09g, 0.00047 mol) and tetrabutyl ammonium iodide ( tetrabutylammonium iodide (0.03g, 0.00009 mol) and the synthesized product 6 (2.5g, 0.0071mol) were added, and the mixture was stirred at room temperature under a nitrogen environment overnight.

The mixture was then washed with saturated sodium bicarbonate (50 ml) and brine (50 ml) and then dried over magnesium sulfate. The solvent was removed under vacuum and the residue was recrystallized from ethanol to give product 7 (yield ca. 70%/4.6 g).

DDQ (2,3-Dichloro-5,6-dicyano-p-benzoquinone, 1.1 g, 0.0049 mol) was added to the solution of the synthesized product 7 (2.1 g, 0.0031 mol) dissolved in dichloromethane at 0 ° C. , the mixture was stirred for 20 minutes under nitrogen environment.

To the mixture, triethylamine (3.4 ml, 0.0246 mol) and BF ₃ OEt ₂ (5 ml, 0.041 mol) were added dropwise at 0°C, and the reaction was stirred at 0°C for 20 minutes and then stirred at room temperature overnight. . The mixture was then washed with 50 ml saturated sodium bicarbonate and 50 ml brine and dried over magnesium sulfate. The solvent was removed under vacuum, and the residue was purified by column chromatography (hexane / ethyl acetate (volume ratio) = 2 / 1) to obtain dye compound 1, denoted as compound 8 (yield was about 83%, 1.9 g).

1) 1H NMR (CDCl ₃ ): 7.88-7.85 (d, 1H), 7.61-7.56 (t, 1H), 7.37-7.28 (m, 2H), 7.18-7.15 (d, 2H), 7.08-7.05 (d) , 2H), 5.78 (s, 1H), 4.45-4.41 (t, 2H), 4.32-4.28 (t, 2H), 3.99 (s, 6H), 2.60-2.58 (m, 4H), 2.51-2.47 (m , 2H), 1.69-1.57 (m, 8H), 1.43-1.39 (m, 4H)

2) UV-VIS spectrum: λmax=535 nm

Using a UV-Vis Spectrophotometer, the dye synthesized in methyl ethyl ketone (MEK) solvent was diluted to 0.001 wt% and the absorption (%) in the 380 nm to 780 nm wavelength range was measured to determine the maximum absorption wavelength.

Preparation Example 2: Synthesis of dye compound 2

o-Nitroaniline (2.78 g, 0.02 mol) was added to HCl (7.5 ml) and stirred, the temperature was lowered to 0°C, and a diluted solution of NaNO ₂ (1.6 g, 0.0231 mol) dissolved in 4 ml distilled water was slowly added. At this time, care was taken to ensure that the temperature did not exceed 5°C. After removing the precipitated material through a filter using a cooled flask, NaOH aqueous solution (60mL, 0.8 g), Na ₂ CO ₃ (6 g), and p-hydroxybenzaldehyde (2.44g, 0.02mol) were added to the filtrate diazonium salt solution for 30 minutes. Added. After stirring at room temperature for 2 hours, the mixture was filtered with distilled water to obtain product 9 (yield: about 57%, 3.1 g).

Product 9 (3.1 g, 0.0114 mol) was dissolved in 1M NaOH aqueous solution (2.4 g, 0.06 mol), and then Zn powder (6 g, 0.0917 mol) was added over 10 minutes. The mixed solution was stirred at 60°C for 4 hours and then filtered with 10% NaOH aqueous solution to obtain a solid. Afterwards, HCl was added dropwise at 0°C to adjust pH to 2, and the precipitate was filtered, and then extracted and concentrated using water and ethyl acetate. This was separated by column with hexane:ethyl acetate (volume ratio = 9:1) to obtain product 10 (yield about 22%, 0.6g).

Product 10 (0.58 g, 0.0024 mol) was mixed with dichloromethane (30 mL), toluene sulfonic acid monohydride (0.46 g, 0.0024 mol), tetrabutylammonium iodide (0.017 g, 0.000048 mol), and methyl 4,5,6,7-tetrahydro-2H. It was mixed with -isoindole-1-carboxylate (0.86 g, 0.0048 mol) and stirred overnight in a nitrogen atmosphere at room temperature. DDQ (0.65 g, 0.0028 mol) was added to the mixture cooled to 0°C and stirred for 20 minutes in a nitrogen atmosphere. Similarly, Triethylamine (4 mL, 0.0288 mol) and BF ₃ OEt ₂ (5.8 ml, 0.048 mol) were slowly added dropwise to the mixture maintained at 0°C and stirred for 20 minutes, and then stirred overnight at room temperature. Afterwards, the reaction was terminated and extracted using NaHCO ₃ (50 mL), brine (50 mL), and MgSO ₄ , and the dye compound 2, denoted as compound 11, was obtained through column purification (hexane:ethyl acetate (volume ratio) = 2:l). Obtained (yield 65%, 0.96 g).

1H NMR: 11.72 (s, 1H), 8.39 (d, 1H), 7.96-7.94 (dd, 2H), 7.54-7.51 (dd, 2H), 7.40-7.38 (d, 1H), 7.25-7.22 (m, 1H), 3.99 (s, 6H), 2.60-2.57 (t, 4H), 1.82-1.78 (t, 4H), 1.61-1.56 (m, 4H), 1.44-1.41 (t, 4H).

Preparation Example 3: Synthesis of dye compound 3

To the above synthesized product 4 (1.7g, 0.0095 mol) dissolved in 30 ml dichloromethane, toluene sulfonic acid monohydride (0.09g, 0.00047 mol) and tetrabutyl ammonium iodide ( tetrabutylammonium iodide (0.03 g, 0.00009 mol) and 2,4,6-trimethylbenzaldehyde (0.7 g, 0.0048 mol) were added, and the mixture was stirred overnight at room temperature in a nitrogen environment.

The mixture was then washed with saturated sodium bicarbonate (50 ml) and brine (50 ml) and then dried over magnesium sulfate. The solvent was removed under vacuum and the residue was recrystallized from ethanol to give product 12 (yield ca. 58%/1.4 g).

DDQ (2,3-Dichloro-5,6-dicyano-p-benzoquinone, 1.1 g, 0.0049 mol) was added to the solution of the synthesized product 12 (1.2 g, 0.0025 mol) dissolved in dichloromethane at 0 ° C. , the mixture was stirred for 20 minutes under nitrogen environment.

To the mixture, triethylamine (3.4 ml, 0.0246 mol) and BF ₃ OEt ₂ (5 ml, 0.041 mol) were added dropwise at 0°C, and the reaction was stirred at 0°C for 20 minutes and then stirred at room temperature overnight. . The mixture was then washed with 50 ml saturated sodium bicarbonate and 50 ml brine and dried over magnesium sulfate. The solvent was removed under vacuum, and the residue was purified by column chromatography (hexane / ethyl acetate = 2 / 1) to obtain dye compound 3, denoted as compound 13 (yield was about 72%, 0.96 g).

1) 1H NMR (CDCl ₃ ): δ 6.97 (s, 2 H), 3.98 (6H, s, 2OCH ₃ ), 2.58-2.55 (4H, m, 2CH ₂ ), 2.35 (3H, s, CH ₃ ), 2.06 (6H, s, 2CH ₃ ), 1.63-1.54 (8H, m, 4CH ₂ ), 1.47-1.39 (4H, m, 2CH ₂ ).

2) UV-VIS spectrum: λmax=539 nm

Using a UV-Vis Spectrophotometer, the dye synthesized in methyl ethyl ketone (MEK) solvent was diluted to 0.001 wt% and the absorption (%) in the 380 nm to 780 nm wavelength range was measured to determine the maximum absorption wavelength.

Preparation Example 4: Preparation of non-reactive low refractive index material

Add 20.51 g of 2,2'-((oxybis(1,1,2,2-tetrafluoroethane-2,1-diyl))bis(oxy))bis(2,2-difluoroethan-1-ol) into a 1000ml flask. After being dissolved in 500 g of tetrahydrofuran, 4.40 g of sodium hydride (60% dispersion in mineral oil) was carefully added several times while stirring at 0°C. After stirring at 0°C for 20 minutes, 12.50 ml of 2-methoxyethoxymethyl chloride was slowly dropped. When it was confirmed by ¹ H NMR that all of the reactants were consumed, the pressure was reduced to remove all of the reaction solvent. Extraction was performed three times with 300 g of dichloromethane, the organic layer was collected, filtered with magnesium sulfate, and the pressure was reduced to remove all dichloromethane, thereby obtaining 29 g of a liquid product with a purity of 95% or higher with a yield of 98%.

Preparation Example 5: Preparation of (meth)acrylate-based (co)polymer with silane-based functional group located in the branch chain

69.3 g of butyl acrylate and 20.7 g of KBM-503 (3-methacryloxypropyltrimethoxysilane) were added to a 2L jacketed reactor, and diluted with 700 g of ethyl acetate. The reaction temperature was set to about 70°C, and stirring was performed for about 1 hour. An additional 0.02 g of n-dodecyl mercaptan was added, and stirring was continued for another 30 minutes. Afterwards, 0.06 g of AIBN, a polymerization initiator, was added, and polymerization was carried out at the reaction temperature for more than 4 hours until the residual acrylate content was less than 1%, thereby forming a (meth)acrylate-based (meth)acrylate-based silane-based functional group located in the branch chain. A co)polymer (weight average molecular weight of approximately 900,000, Si-(OR) ₃ equivalents of 1019 g/equivalent) was prepared.

Preparation Example 6: Preparation of silane crosslinking agent

19.79 g of KBE-9007 (3-isocyanatopropyltriethoxysilane), 12.80 g of PEG-400, and 0.57 g of DBTDL were added to a 1000 ml flask, and diluted with 300 g of tetrahydrofuran. After stirring at room temperature until TLC confirmed that all of the reactants were consumed, the pressure was reduced to remove all of the reaction solvent.

A silane crosslinking agent was obtained by separating 28 g of a liquid product with a purity of 95% or more in a yield of 91% through column chromatography under the eluent condition of dichloromethane:methyl alcohol = 30:1.

[Examples and Comparative Examples]

As shown in Table 1 below, a (meth)acrylate-based (co)polymer in which the silane-based functional group of Preparation Example 5 is located in the branched chain, a photoreactive monomer (highly refractive acrylate, refractive index 1.600, HR6022 [Miwon]), prepared Non-reactive low refractive index material of Example 4, tributyl phosphate [TBP], molecular weight 266.31, refractive index 1.424, manufactured by Sigma Aldrich, Ethyl Violet and Eosin (dye, manufactured by Sigma Aldrich), dye compound, Ebecryl P- Mix 115 (SK entis), Borate V (Spectra group), Irgacure 250 (Onium salt, BASF), and methyl isobutyl ketone (MIBK) while blocking light, and stir with a paste mixer for about 10 minutes to create a transparent coating solution. Obtained.

The silane crosslinking agent described in Preparation Example 6 was added to the coating solution and stirred for an additional 5 to 10 minutes. Afterwards, DBTDL, a catalyst, was added to the coating solution and stirred for about 1 minute. Then, using a Meyer bar, the coating was coated to a thickness of 7 ㎛ on an 80 ㎛ thick TAC substrate and dried at 40° C. for 1 hour to prepare a hologram recording medium.

[Experimental example: holographic recording]

(1) The photopolymer (holographic recording medium) coated surface prepared in each of the above examples and comparative examples was laminated to a glass slide and fixed so that the laser passes through the glass surface first during recording.

(2) Diffraction efficiency (η) measurement

Holographic recording is performed through the interference of two coherent lights (reference light and object light), and in transmission type recording, both beams are incident on the same plane of the sample. Diffraction efficiency changes depending on the angle of incidence of the two beams, and when the angle of incidence of the two beams is the same, it becomes non-slanted. In non-slanted recording, the angle of incidence of both beams is the same relative to the normal, so the diffraction grating is generated perpendicular to the film.

Recording was performed in a transmissive non-slanted manner (2θ=45°) using a laser with a 532nm wavelength or a laser with a 633nm wavelength, and the diffraction efficiency (η) was calculated using the following general formula 1.

[General Formula 1]

In General Formula 1, η is the diffraction efficiency, P _D is the output amount of the diffracted beam of the sample after recording (mW/cm2), and P _T is the output amount of the transmitted beam of the recorded sample (mW/cm2).

(3) Measurement of refractive index modulation value (n)

For the Lossless Dielectric grating of a transmissive hologram, the refractive index modulation value (△n) can be calculated from the following general formula 2.

[General Formula 2]

In General Formula 2, d is the thickness of the photopolymer layer, Δn is the refractive index modulation value, η(DE) is the diffraction efficiency, and λ is the recording wavelength.

(4) Heat resistance and moist heat stability (%)

The photopolymer film prepared in the example was stored in an oven at 60°C for 72 hours, and then heat stability was calculated based on the rate of change in transmittance. The transmittance was measured using a UV/VIS spectrometer for the hologram recording media manufactured in each of the examples and comparative examples.

[General Formula 3]

In General Formula 3, T ₀ refers to the initial transmittance, and T ₇₂ refers to the transmittance measured after storage in an oven at 60° C. for 72 hours.

In addition, after storage in a constant temperature and humidity chamber at 65°C 95% for 72 hours, heat and moisture stability was confirmed by the rate of change in permeability.

[General Formula 4]

In General Formula 4, T ₀ refers to the initial transmittance, and T ₇₂ refers to the transmittance measured after storage in an oven at 60° C. for 72 hours.

Experimental measurement results of the photopolymer composition (unit: g) of the example and the holographic recording medium prepared therefrom division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative example 2 Comparative Example 3 (Meth)acrylate-based copolymer Manufacturing example 4 21.5 21.5 21.5 21.5 21.5 21.5 21.5 Linear silane crosslinking agent Manufacturing example 5 6.1 6.1 6.1 6.1 6.1 6.1 6.1 Photoreactive monomer HR6022 40.2 40.2 40.2 40.2 40.2 40.2 40.2 Dye Manufacturing Example 1 0.1 0.1 Manufacturing example 2 0.1 0.1 Manufacturing example 3 0.1 Ethyl Violet (Aldrich) 0.1 Eosin (Aldrich) 0.1 initiator Amine (Ebecryl P-115) 1.5 1.5 1.5 Borate salt (Borate V) 0.12 0.12 0.26 0.26 0.26 0.26 0.26 Onium salt (Irgacure 250) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Non-reactive low-index material Manufacturing example 3 30 30 30 30 30 30 30 catalyst DBTDL (dibutyltin dilaurate) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 additive Tego Rad 2500 0.22 0.22 0.22 0.22 0.22 0.22 0.22 menstruum MIBK 295 295 295 296 300 300 300 Coating thickness (unit: ㎛) 10 10 10 10 10 10 10 diffraction efficiency 68 78 75 82 60 32 24 △n 0.021 0.024 0.023 0.025 0.018 0.010 0.011 Heat resistance stability (%) 95 92 95 92 90 75 62 Moist and heat resistance stability (%) 81 79 82 79 75 50 44

As shown in Table 1, it was confirmed that the hologram recording media of Examples 1 to 4 could achieve a diffraction efficiency of 68 or more and a refractive index modulation value (Δn) of 0.02 or more at a thickness of 6.5 μm. In addition, it was confirmed that heat resistance stability and moist heat resistance stability were excellent, with heat resistance stability of more than 92% and moist heat resistance stability of more than 79%.

In contrast, it was confirmed that the hologram recording media of Comparative Examples 1 to 3 had relatively low diffraction efficiency compared to the Examples. In addition, it was confirmed that heat resistance stability and moist heat resistance stability were poor compared to the examples, with heat resistance stability being 90% or less and moist heat resistance stability being 75% or less.

Claims (17)

Compound represented by Formula 1:
[Formula 1]

In Formula 1,
R ₁ to R ₅ are the same or different from each other, and each independently represents hydrogen, deuterium, halogen group, nitrile group, nitro group, hydroxy group, carboxyl group, alkyl group with 1 to 20 carbon atoms, cycloalkyl group with 4 to 20 carbon atoms, and 1 to 20 carbon atoms. alkoxy group, aryloxy group having 6 to 20 carbon atoms, alkylthioxy group having 1 to 20 carbon atoms, arylthioxy group having 6 to 20 carbon atoms, alkylsulfoxy group having 1 to 20 carbon atoms, arylsulfoxy group having 6 to 20 carbon atoms, carbon number It is an alkenyl group of 2 to 20 carbon atoms, an amine group, an aryl group of 6 to 20 carbon atoms, -Y-(CH ₂ )pO-Ar ₁ , or a monovalent functional group derived from a heterocyclic aromatic compound,
At least one of R ₁ to R ₅ is -Y-(CH ₂ )pO-Ar ₁ or a monovalent functional group derived from a heterocyclic aromatic compound,
Y is an ether group or an ester group,
p is an integer greater than or equal to 1,
Ar ₁ is an aromatic compound having 3 or more carbon atoms,
R ₆ to R ₉ are the same or different from each other, and each independently represents hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, a cycloalkyl carboxylate group with 4 to 20 carbon atoms, or a carbon number. It is an aryl carboxylate group of 6 to 20,
X _{1 and}
m and n are the same as or different from each other, and are each independently integers from 0 to 4.
According to paragraph 1,
In Formula 1,
Ar ₁ is a multi-ring aromatic compound having 3 or more carbon atoms,
A compound in which the monovalent functional group derived from a heterocyclic aromatic compound includes a monovalent functional group derived from a heteromulticyclic aromatic compound having 3 or more carbon atoms.
According to paragraph 1,
The compound wherein Ar ₁ and the monovalent functional group derived from the heterocyclic aromatic compound include a monovalent functional group derived from a heteromulticyclic aromatic compound having 3 or more carbon atoms.
According to paragraph 1,
A compound wherein at least one of R ₁ to R ₅ is a monovalent functional group derived from a heterocyclic aromatic compound, and the other is a hydroxy group.
According to paragraph 1,
R ₆ and R ₇ are the same or different from each other, and each independently represents an alkyl carboxylate group having 1 to 20 carbon atoms, a cycloalkyl carboxylate group having 4 to 20 carbon atoms, or an aryl carboxylate group having 6 to 20 carbon atoms,
The compound wherein X ₁ and X ₂ are halogen groups.
According to paragraph 1,
The compound represented by Formula 1 includes a compound represented by the following Formula 1-1 or a compound represented by Formula 1-2:
[Formula 1-1]

In Formula 1-1,
Y is an ether group or an ester group,
p is an integer greater than or equal to 1,
Ar ₁ is an aromatic compound having 3 or more carbon atoms,
R ₈ and R ₉ are the same or different from each other, and are each independently hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, a cycloalkyl carboxylate group with 4 to 20 carbon atoms, or a carbon number It is an aryl carboxylate group of 6 to 20,
m and n are the same or different from each other and are each independently an integer between 0 and 4,
X _{1 and}
R ₂₀ and R ₂₁ are the same as or different from each other, and are each independently an alkyl group with 1 to 19 carbon atoms, a cycloalkyl group with 4 to 19 carbon atoms, or an aryl group with 6 to 19 carbon atoms,
[Formula 1-2]

In Formula 1-2,
One of R ₁₁ and R ₁₂ is a monovalent functional group derived from a heterocyclic aromatic compound, and the other is a hydroxy group,
R ₈ and R ₉ are the same or different from each other, and are each independently hydrogen, a halogen group, an alkyl group with 1 to 10 carbon atoms, an alkyl carboxylate group with 1 to 20 carbon atoms, a cycloalkyl carboxylate group with 4 to 20 carbon atoms, or a carbon number It is an aryl carboxylate group of 6 to 20,
m and n are the same or different from each other and are each independently an integer between 0 and 4,
X _{1 and}
R ₂₀ and R ₂₁ are the same as or different from each other, and each independently represents an alkyl group with 1 to 19 carbon atoms, a cycloalkyl group with 4 to 19 carbon atoms, or an aryl group with 6 to 19 carbon atoms.
polymer matrix or precursor thereof;
A dye comprising the compound of claim 1;
Photoreactive monomer; and
A photoinitiator; a photopolymer composition containing a.
In clause 7,
The polymer matrix or its precursor is 1) a reaction product between a compound containing at least one isocyanate group and a polyol; or 2) a polymer matrix comprising a (meth)acrylate-based (co)polymer in which the silane-based functional group is located in the branch chain and a silane crosslinking agent. A photopolymer composition comprising a.
According to clause 8,
The silane crosslinking agent is a photopolymer composition comprising a linear polyether main chain having a weight average molecular weight of 100 g/mol to 2000 g/mol and a silane-based functional group bonded to an end or branch chain of the main chain.
According to clause 8,
The (meth)acrylate-based (co)polymer in which the silane-based functional group is located in the branch chain is
It includes a (meth)acrylate repeating unit and a (meth)acrylate repeating unit in which the silane-based functional group is located in the branch chain,
A photopolymer composition having a weight average molecular weight of 100,000 g/mol to 1,000,000 g/mol.
According to clause 8,
A photopolymer composition wherein the photoreactive monomer includes a polyfunctional (meth)acrylate monomer or a monofunctional (meth)acrylate monomer.
According to clause 8,
1% to 80% by weight of the polymer matrix or its precursor based on the total weight of the photopolymer composition; 1% to 80% by weight of the photoreactive monomer; 0.0001% to 10% by weight of the dye; And 0.1% to 20% by weight of photoinitiator; a photopolymer composition comprising a.
According to clause 8,
The photopolymer composition further includes at least one selected from the group consisting of a catalyst, a phosphate-based compound, and a low-refractive-index fluorine-based compound.
According to clause 13,
A photopolymer composition wherein the low refractive index fluorine-based compound includes at least one functional group selected from the group consisting of an ether group, an ester group, and an amide group, and at least two difluoromethylene groups.
A hologram recording medium prepared from the photopolymer composition of claim 8.
An optical element including the hologram recording medium of claim 15.
A holographic recording method comprising the step of selectively polymerizing the photoreactive monomer contained in the photopolymer composition of claim 8 by a coherent light source.