Fluorine-based compound, photopolymerizable composition, hologram recording medium, method for producing the same, and optical element including the same

Abstract

The present invention relates to a fluorine-based compound, a photopolymerizable composition, a hologram recording medium, a method for producing the same, and an optical element including the same. The fluorine-based compound is contained in the photopolymerizable composition and not only has excellent optical recording characteristics, but also can provide a hologram recording medium having transparent optical characteristics and excellent reliability even in a high-temperature and high-humidity environment, and an optical element including the same.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0146091, filed on November 4, 2022, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference in their entirety.

[0002] This application relates to a fluorine - based compound, a photopolymerizable composition, a hologram recording medium, a method for manufacturing the same, and an optical element including the same.

Background Art

[0003] A hologram recording medium records information by changing the refractive index in a holographic recording layer during an exposure process, and reads the difference in the refractive index thus recorded to reproduce the information.

[0004] In this regard, a photopolymer composition can be used for manufacturing holograms. A photopolymer can easily store an optical interference pattern as a hologram by photopolymerization of a photoreactive monomer. Therefore, photopolymers can be used in various fields such as smart devices like mobile devices, components of wearable displays, vehicle supplies (e.g., head up display), holographic fingerprint recognition systems, optical lenses, mirrors, deflecting mirrors, filters, diffusing screens, diffractive members, light guides, waveguides, projection screens and / or holographic optical elements having functions of masks, media for optical memory systems and light diffusing plates, optical wavelength dividers, reflective and transmissive color filters, etc.

[0005] Specifically, a photopolymer composition for hologram production includes a polymer matrix, a photoreactive monomer, and a photoinitiator system. Then, laser interference light is irradiated onto a photopolymer layer produced from such a composition to induce local photopolymerization of the monomer.

[0006] Such a local photopolymerization process causes a refractive index modulation, and such a refractive index modulation generates a diffraction grating. The refractive index modulation value (Δn) 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.

[0007] Recently, there has been an increasing demand for the development of materials that can maintain a high diffraction efficiency and a stable hologram. Various attempts have been made to manufacture holographic recording media that have a large diffraction efficiency and a refractive index modulation value while having a thin thickness.

[0008] As part of such efforts, various plasticizers that can be added to the photopolymer composition have been developed. Plasticizers that are non-reactive and have a low refractive index can improve the moldability of the photopolymer composition while moving in the other direction with the photoreactive monomer having a high refractive index and contributing to a larger refractive index modulation.

[0009] However, as various components such as plasticizers are added to the photopolymer composition, their compatibility deteriorates, the basic physical properties of the holographic recording medium decrease, and problems such as clouding of the holographic recording medium occur. In addition, when the holographic recording medium is applied to mobile devices and vehicle supplies (e.g., Head-up display) that may be placed in a high-temperature and high-humidity environment due to a decrease in the durability of the holographic recording medium against heat and moisture, deformation of the diffraction grating occurs, resulting in problems such as image distortion and inability to exhibit the originally intended function.

[0010] Therefore, at present, it is necessary to develop a new material that is excellent in compatibility with the components of the holographic recording medium but does not reduce their durability against heat and moisture, and at the same time can improve the optical recording characteristics.

Summary of the Invention

Problems to be Solved by the Invention

[0011] According to an embodiment of the present invention, a fluorine-based compound is provided.

[0012] According to another embodiment of the present invention, a photopolymerizable composition is provided.

[0013] According to still another embodiment of the present invention, a hologram recording medium formed from the photopolymerizable composition and a method for manufacturing the same are provided.

[0014] According to still another embodiment of the present invention, an optical element including the hologram recording medium is provided.

Means for Solving the Problems

[0015] Hereinafter, a fluorine-based compound, a photopolymerizable composition, a hologram recording medium, a method for manufacturing the same, and an optical element including the same according to specific embodiments of the invention will be described.

[0016] According to one embodiment of the invention, a fluorine-based compound represented by the following Chemical Formula 1 is provided.

[0017] [Chemical Formula 1]

Chemical

[0018] In the Chemical Formula 1, Z 1 and Z 2 are each independently -O-, -S- or -NH-, R 1 ~R 4 at least one of which is a fluorine-containing substituent, an alkyl group having 1 to 20 carbon atoms substituted with 2 or more fluorines, a cycloalkyl group having 3 to 30 carbon atoms substituted with 2 or more fluorines, or an aryl group having 6 to 30 carbon atoms substituted with 2 or more fluorines, R 1 ~R 4When it is not a fluorine-containing substituent, each is independently an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a heterocycloalkyl group having 4 to 30 carbon atoms, a cycloalkylalkyl group having 7 to 40 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 4 to 30 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, or a substituent in which one or more -CH2- of the substituent is substituted with -O-, -S-, or -NH-.

[0019] Hereinafter, a fluorine-based compound according to an embodiment of the present invention, a photopolymerizable composition containing the same, a hologram recording medium formed from the photopolymerizable composition and a method for manufacturing the same, and an optical element including the hologram recording medium will be described in detail.

[0020] In the fluorine-based compound of the above embodiment, since fluorine is distributed at the end of the compound, it has excellent properties such as fluidity, diffusibility, and antifouling properties due to fluorine. As a result, the fluorine-based compound can be used in various applications such as a plasticizer, a surfactant, or an antifouling agent in various fields. Among them, the fluorine-based compound of the above embodiment can contribute to increasing the refractive index modulation when applied as a plasticizer to a hologram recording medium due to its low refractive index and non-reactive properties.

[0021] In particular, the present inventors have confirmed through experiments that the fluorine-based compound represented by the above Chemical Formula 1 is excellent in compatibility with other components forming a hologram recording medium, excellent in stability against heat and moisture, shows transparent optical properties while improving optical recording properties, and can provide a hologram recording medium showing high reliability even in a high temperature / high humidity environment, and thus completed the present invention.

[0022] In the above Chemical Formula 1, R 1 ~R 4 At least one or more of them are fluorine-containing substituents. As an example, the R 1 may be a fluorine-containing substituent.

[0023] The fluorine-containing substituent may be an alkyl group having 1 to 20 carbon atoms substituted with 2 or more fluorines, a cycloalkyl group having 3 to 30 carbon atoms substituted with 2 or more fluorines, or an aryl group having 6 to 30 carbon atoms substituted with 2 or more fluorines.

[0024] Specifically, the fluorine-containing substituent may be a linear alkyl group having 1 to 20 carbon atoms substituted with 2 or more fluorines, a cycloalkyl group having 3 to 12 carbon atoms substituted with 2 or more fluorines, or an aryl group having 6 to 14 carbon atoms substituted with 2 or more fluorines.

[0025] More specifically, the fluorine-containing substituent is -(CH2) a (CF2) b CHF2, -(CH2) a (CF2) b CF3, a decafluorocyclohexyl group, or a pentafluorophenyl group. Here, a is an integer from 0 to 3, an integer from 0 to 2, or an integer from 0 to 1, and b may be an integer from 0 to 19, an integer from 0 to 15, an integer from 0 to 14, an integer from 0 to 13, an integer from 0 to 12, or an integer from 0 to 11.

[0026] As an example, the fluorine-containing substituent may be -(CH2) a (CF2) b CHF2, -(CH2) a (CF2) b CF3, or a decafluorocyclohexyl group.

[0027] In Chemical Formula 1, when R 1 ~R 4 is not a fluorine-containing substituent, R 1 ~R 4is independently an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a heterocycloalkyl group having 4 to 30 carbon atoms, a cycloalkylalkyl group having 7 to 40 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 4 to 30 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, or a substituent in which one or more -CH2- of the substituent is substituted with -O-, -S- or -NH-.

[0028] Specifically, in the chemical formula 1, R 1 ~R 4 When is not a fluorine-containing substituent, R 1 ~R 4 is independently a linear alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a heterocycloalkyl group having 4 to 12 carbon atoms, an aryl group having 6 to 14 carbon atoms, a heteroaryl group having 4 to 12 carbon atoms, an arylalkyl group having 7 to 16 carbon atoms, or -(R 5 -Y 1 ) c -R 6 may be. In the -(R 5 -Y 1 ) c -R 6 In, R 5 is an alkylene group having 1 to 6 carbon atoms, R 6 is an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms, Y 1 is -O- or -S-, and c may be an integer of 1 to 12. When c is 2 or more, R 5 may be the same as or different from each other.

[0029] More specifically, in the chemical formula 1, R 1 ~R 4 When is not a fluorine-containing substituent, R 1 ~R 4is, independently of each other, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a phenyl group, a benzyl group, a pyridinyl group, a pyrimidinyl group, a methoxymethyl group, a methoxyethyl group, a methylmercaptoethyl group, a methylaminoethyl group, -(CH2CH2O) c1 CH3, -CH2O(CH2CH2O) c2 CH3, and may be a cyclohexyloxyethyl group, a cyclohexylmercaptoethyl group or a phenyloxyethyl group. Here, c1 is an integer of 1 to 5, and c2 is an integer of 1 to 4.

[0030] The fluorine-based compound represented by Chemical Formula 1 can contain one or more fluorine-based compounds selected from the group consisting of fluorine-based compounds represented by the following Chemical Formulas 1-1 to 1-9.

[0031] [Chemical Formula 1-1]

Chemical Structure

[0032] In Chemical Formula 1-1, Z a1 and Z b1 are, independently of each other, -O-, -S- or -NH-, R a1 and R b1 are, independently of each other, CF3 or CHF2, R c1 and R c2 are, independently of each other, an alkylene group having 1 to 6 carbon atoms, Y a1 and Y a2 are, independently of each other, -CH2-, -O-, -S- or -NH-, R d1 and R d2 are, independently of each other, an alkylene group having 1 to 4 carbon atoms, R e1 and R e2is, independently of each other, hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p1 and p2 are, independently of each other, integers from 0 to 9, and q1 and q2 are, independently of each other, integers from 0 to 3.

[0033] [Chemical Formula 1-2] [Chem.]

[0034] In the above Chemical Formula 1-2, Z a2 and Z b2 are, independently of each other, -O-, -S- or -NH-, R a2 is CF3 or CHF2, R c3 ~R c5 are, independently of each other, alkylene groups having 1 to 6 carbon atoms, Y a3 ~Y a5 are, independently of each other, -CH2-, -O-, -S- or -NH-, R d3 ~R d5 are, independently of each other, alkylene groups having 1 to 4 carbon atoms, R e3 ~R e5 are, independently of each other, hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p3 is an integer from 0 to 9, and q3 to q5 are, independently of each other, integers from 0 to 3.

[0035] [Chemical Formula 1-3] [Chem.]

[0036] In the above Chemical Formula 1-3, Z a3 and Z b3 are, independently of each other, -O-, -S- or -NH-, R a3 、R b2 and R b3 are each independently CF3 or CHF2, R c6 is an alkylene group having 1 to 6 carbon atoms, Y a6 is -CH2-, -O-, -S- or -NH-, R d6 is an alkylene group having 1 to 4 carbon atoms, R e6 is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, R f1 and R f2 are each independently hydrogen or fluorine, p4 to p6 are each independently an integer from 0 to 9, and q6 is an integer from 0 to 3.

[0037] [Chemical Formula 1-4] [Chem.]

[0038] In the above Chemical Formula 1-4, Z a4 and Z b4 are each independently -O-, -S- or -NH-, R a4 、R a5 、R b4 and R b5 are each independently CF3 or CHF2, R f3 ~R f6 are each independently hydrogen or fluorine, p7 to p10 are each independently an integer from 0 to 9.

[0039] [Chemical Formula 1-5] [Chem.]

[0040] In the above Chemical Formulas 1-5, Z a5 and Z b5 are each independently -O-, -S- or -NH-; R a6 and R a7 are each independently CF3 or CHF2; R c7 and R c8 are each independently an alkylene group having 1 to 6 carbon atoms; Y a7 and Y a8 are each independently -CH2-, -O-, -S- or -NH-; R d7 and R d8 are each independently an alkylene group having 1 to 4 carbon atoms; R e7 and R e8 are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group; p11 to p12 are each independently an integer from 0 to 9, and q7 and q8 are each independently an integer from 0 to 3.

[0041] [Chemical Formula 1-6]

Chemical Structure

[0042] In the above Chemical Formulas 1-6, Z a6 and Z b6 are each independently -O-, -S- or -NH-; R a8 ~R a10 are each independently CF3 or CHF2; R c9 is an alkylene group having 1 to 6 carbon atoms; Y a9 is -CH2-, -O-, -S- or -NH-; R d9 is an alkylene group having 1 to 4 carbon atoms; R e9 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p13 to p15 are each independently an integer of 0 to 9, and q9 is an integer of 0 to 3. [Chemical Formula 1-7]

Chem.

[0043] In the Chemical Formula 1-7, Z a7 and Z b7 are each independently -O-, -S- or -NH-, R b9 、R c10 and R d10 are each independently a decafluorocyclohexyl group, a phenyl group, a pyridinyl group, a pyrimidinyl group or a methoxyethyl group.

[0044] [Chemical Formula 1-8]

Chem.

[0045] In the Chemical Formula 1-8, Z a8 and Z b8 are each independently -O-, -S- or -NH-, R b10 、R c11 and R d11 are each independently a 2,2,3,3,4,4,5,5-octafluoro-1-pentyl group, a decafluorocyclohexyl group, a phenyl group or a methoxyethyl group.

[0046] [Chemical Formula 1-9]

Chem.

[0047] In the Chemical Formula 1-9, Z a9 and Z b9 each independently represents -O-, -S- or -NH-; R a11 and R b11 each independently represents CF3 or CHF2; R c12 and R d12 each independently represents a phenyl group or a benzyl group; p16 and p17 each independently represent an integer from 0 to 9.

[0048] On the other hand, according to another embodiment of the invention, there is provided a photopolymerizable composition containing the fluorine-based compound; the polymer matrix or its precursor; the photoreactive monomer; and the photoinitiator system.

[0049] The fluorine-based compound is the fluorine-based compound represented by Chemical Formula 1 described above, and a detailed description thereof is omitted here.

[0050] The photopolymerizable composition can be used in various technical fields. As an example, the photopolymerizable composition can be used as a photopolymer composition for forming a hologram recording medium.

[0051] Hereinafter, an example in which the photopolymerizable composition is used as a photopolymer composition for forming a hologram recording medium will be described in detail.

[0052] The photopolymer composition includes a polymer matrix or its precursor that serves as a support for the photopolymer layer to be formed therefrom.

[0053] The polymer matrix is formed by crosslinking a siloxane-based polymer containing a silane functional group (Si-H) and a (meth)acrylic polyol. Specifically, the polymer matrix is obtained by crosslinking a (meth)acrylic polyol with a siloxane-based polymer containing a silane functional group. More specifically, the hydroxy group of the (meth)acrylic polyol can form a crosslinking bond with the silane functional group of the siloxane-based polymer through a hydrosilylation reaction. The hydrosilylation reaction proceeds rapidly even at room temperature (for example, a temperature in the range of about 15 to 30 °C, which is the temperature without heating or cooling) under a Pt-based catalyst. Therefore, by adopting a polymer matrix that can be rapidly crosslinked at room temperature as a support, the manufacturing efficiency and productivity of the hologram recording medium can be improved.

[0054] The polymer matrix can enhance the mobility of components (such as photoreactive monomers or plasticizers, etc.) contained in the photopolymer layer due to the flexible main chain of the siloxane-based polymer. In addition, the siloxane bond with excellent heat and moisture-heat resistance can easily ensure the reliability of the photopolymer layer in which optical information is recorded and the hologram recording medium containing the same.

[0055] The polymer matrix can have a relatively low refractive index, thereby playing a role in enhancing the refractive index modulation of the layer formed from the photopolymer composition. For example, the upper limit of the refractive index of the polymer matrix may be 1.53 or less, 1.52 or less, 1.51 or less, 1.50 or less, or 1.49 or less. And the lower limit of the refractive index of the polymer matrix may be, for example, 1.40 or more, 1.41 or more, 1.42 or more, 1.43 or more, 1.44 or more, 1.45 or more, or 1.46 or more. In this specification, the "refractive index" may be a value measured with an Abbe refractometer at 25 °C.

[0056] The photo-polymer composition can include the polymer matrix in the cross-linked form described above, or a precursor thereof. When the photo-polymer composition includes a precursor of the polymer matrix, it can include a siloxane-based polymer, a (meth)acrylic polyol, and a Pt-based catalyst.

[0057] The siloxane-based polymer can include, as an example, a repeating unit represented by the following Chemical Formula 2 and a terminal group represented by the following Chemical Formula 3.

[0058] [Chemical Formula 2] [Chemical Structure]

[0059] In Chemical Formula 2, a plurality of R 11 and R 12 are the same as or different from each other, and each independently is hydrogen, a halogen, or an alkyl group having 1 to 10 carbon atoms, k is an integer from 1 to 10,000, [Chemical Formula 3] [Chemical Structure] In Chemical Formula 3, a plurality of R 13 ~R 15 are the same as or different from each other, and each independently is hydrogen, a halogen, or an alkyl group having 1 to 10 carbon atoms, at least one of R 11 ~R 15 of at least one of the repeating units represented by Chemical Formula 2 and the terminal group represented by Chemical Formula 3 is hydrogen.

[0060] In Chemical Formula 3, -(O)- means that when Si of the terminal group represented by Chemical Formula 3 is bonded to the repeating unit represented by Chemical Formula 2, it is bonded via oxygen (O) or directly bonded without oxygen (O).

[0061] As used herein, the "alkyl group" may be a straight-chain, branched-chain or cyclic alkyl group. By way of non-limiting example, as used herein, the "alkyl group" includes methyl, ethyl, propyl (e.g., n-propyl, isopropyl, etc.), butyl (e.g., n-butyl, isobutyl, tert-butyl, sec-butyl, cyclobutyl, etc.), pentyl (e.g., n-pentyl, isopentyl, neopentyl, tert-pentyl, 1,1-dimethyl-propyl, 1-ethyl-propyl, 1-methyl-butyl, cyclopentyl, etc.), hexyl (e.g., n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methylpentyl, 3,3-dimethylbutyl, 1-ethyl-butyl, 2-ethylbutyl, cyclopentylmethyl, cyclohexyl, etc.), heptyl (e.g., n-heptyl, 1-methylhexyl, 4-methylhexyl, 5-methylhexyl, cyclohexylmethyl, etc.), octyl (e.g., n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, etc.), nonyl (e.g., n-nonyl, 2,2-dimethylheptyl, etc.), and the like.

[0062] As an example, R 11 ~R 15 in Chemical Formulas 2 and 3 is methyl or hydrogen, and at least two of the plurality of R 11 ~R 15 may be hydrogen. More specifically, as the siloxane polymer, R 11 and R 12 in Chemical Formula 2 are methyl and hydrogen, respectively, and R 13 ~R 15 in Chemical Formula 3 are each independently methyl or hydrogen (e.g., polymethylhydrogensiloxane having a trimethylsilyl group or a dimethylhydrosilyl group as a terminal group); a part of R 11 and R 12 in Chemical Formula 2 are methyl and hydrogen, respectively, and the remaining R 11 and R 12 are all methyl, and R 13 ~R 15A compound in which each is independently methyl or hydrogen (for example, poly(dimethylsiloxane-co-methylhydrogensiloxane) having a terminal group of a trimethylsilyl group or a dimethylhydrogensilyl group); or R in the chemical formula 2 above 11 and R 12 are all methyl, and at least one of R 13 to R 15 is hydrogen and the rest are each independently methyl or hydrogen (for example, polydimethylsiloxane in which any one or all of the terminal groups are dimethylhydrogensilyl groups) may be used.

[0063] The siloxane compound can have a number average molecular weight (Mn) in the range of 200 to 4,000, for example. Specifically, the lower limit of the number average molecular weight of the siloxane polymer may be, for example, 200 or more, 250 or more, 300 or more, or 350 or more, and the upper limit thereof may be, for example, 3,500 or less, 3,000 or less, 2,500 or less, 2,000 or less, 1,500 or less, or 1,000 or less. When the number average molecular weight of the siloxane polymer satisfies the above range, problems such as the siloxane polymer volatilizing during the cross-linking process with the (meth)acrylic polyol carried out at room temperature or a higher temperature and the matrix cross-linking degree decreasing, or the siloxane polymer having poor compatibility with the components of other photopolymer compositions and phase separation occurring with such components are prevented, enabling the hologram recording medium formed from the photopolymer composition to exhibit excellent optical recording characteristics and excellent durability under high temperature / high humidity conditions.

[0064] The number average molecular weight means the number average molecular weight in terms of polystyrene (unit: g / mol) measured by the GPC method. In the process of measuring the number average molecular weight in terms of polystyrene measured by the GPC method, a commonly known analytical instrument, detectors such as a refractive index detector, and analytical columns can be used, and the usually applied temperature conditions, solvent, and flow rate can be applied. Specific examples of the measurement conditions include a temperature of 25 °C, a tetrahydrofuran solvent (Tetrahydrofuran), and a flow rate of 1 mL / min.

[0065] The (meth)acrylic polyol can mean a polymer in which one or more, specifically two or more hydroxy groups are bonded to the main chain or side chain of a (meth)acrylate polymer. In this specification, "(meth)acrylic (system)" refers to acrylic (system) and / or methacrylic (system) unless otherwise specified, and is a term that encompasses all of acrylic (system), methacrylic (system), or a mixture of acrylic (system) and methacrylic (system).

[0066] The (meth)acrylic polyol may be a homopolymer of a (meth)acrylate monomer having a hydroxy group, a copolymer of two or more (meth)acrylate monomers having a hydroxy group, or a copolymer of a (meth)acrylate monomer having a hydroxy group and a (meth)acrylate monomer having no hydroxy group. In this specification, "copolymer" refers to all of a random copolymer, a block copolymer, and a graft copolymer unless otherwise specified.

[0067] Examples of the (meth)acrylate monomer having a hydroxy group include hydroxyalkyl (meth)acrylate or hydroxyaryl (meth)acrylate. The alkyl is an alkyl having 1 to 30 carbon atoms, and the aryl may be an aryl having 6 to 30 carbon atoms. Examples of the (meth)acrylate monomer having no hydroxy group include alkyl (meth)acrylate monomer or aryl (meth)acrylate monomer. The alkyl is an alkyl having 1 to 30 carbon atoms, and the aryl may be an aryl having 6 to 30 carbon atoms.

[0068] As an example, the (meth)acrylic polyol can have a weight average molecular weight (Mw) in the range of 150,000 to 1,000,000. The weight average molecular weight means the weight average molecular weight in terms of polystyrene measured by the GPC method as described above. For example, the lower limit of the weight average molecular weight may be 150,000 or more, 200,000 or more, or 250,000 or more, and the upper limit may be, for example, 900,000 or less, 850,000 or less, 800,000 or less, 750,000 or less, 700,000 or less, 650,000 or less, 600,000 or less, 550,000 or less, 500,000 or 450,000 or less. When the weight average molecular weight of the (meth)acrylic polyol satisfies the above range, the polymer matrix can sufficiently exhibit the function of the support, and even when the use time elapses, the decrease in the recording characteristics for optical information is small. Sufficient flexibility is imparted to the polymer matrix to improve the mobility of the components (for example, photoreactive monomers or plasticizers, etc.) contained in the photopolymer composition, and the decrease in the recording characteristics for optical information can be minimized.

[0069] In order to adjust the crosslinking density of the (meth)acrylic polyol by the siloxane polymer to a level advantageous for ensuring the function of the hologram recording medium, the hydroxyl equivalent of the (meth)acrylic polyol can be adjusted to an appropriate level.

[0070] Specifically, the hydroxyl group (-OH) equivalent of the (meth)acrylic polyol may be, for example, in the range of 500 to 3,000 g / equivalent. More specifically, the lower limit of the hydroxyl group (-OH) equivalent of the (meth)acrylic polyol is 600 g / equivalent or more, 700 g / equivalent or more, 800 g / equivalent or more, 900 g / equivalent or more, 1,000 g / equivalent or more, 1,100 g / equivalent or more, 1,200 g / equivalent or more, 1,300 g / equivalent or more, 1,400 g / equivalent or more, 1,500 g / equivalent or more, 1,600 g / equivalent or more, 1,700 g / equivalent or more, or 1,750 g / equivalent or more. And the upper limit of the hydroxyl group (-OH) equivalent of the (meth)acrylic polyol is 2,900 g / equivalent or less, 2,800 g / equivalent or less, 2,700 g / equivalent or less, 2,600 g / equivalent or less, 2,500 g / equivalent or less, 2,400 g / equivalent or less, 2,300 g / equivalent or less, 2,200 g / equivalent or less, 2,100 g / equivalent or less, 2,000 g / equivalent or less, or 1,900 g / equivalent or less. The hydroxyl group (-OH) equivalent of the (meth)acrylic polyol is the equivalent (g / equivalent) per one hydroxy functional group, and is a value obtained by dividing the weight average molecular weight of the (meth)acrylic polyol by the number of hydroxy functional groups per molecule. The smaller the equivalent value, the higher the density of the functional group, and the larger the equivalent value, the lower the density of the functional group. When the hydroxyl group (-OH) equivalent of the (meth)acrylic polyol satisfies the above range, the polymer matrix has an appropriate crosslinking density and sufficiently plays the role of a support, the fluidity of the components contained in the layer formed from the photopolymer composition is improved, and there is no problem that the interface of the diffraction grating generated after recording collapses. Even as time passes, the initial refractive index modulation value can be maintained at an excellent level, and the decrease in the recording characteristics for optical information can be minimized.

[0071] The (meth)acrylic polyol can have a glass transition temperature (Tg) in the range of, for example, -60 to -10°C. Specifically, the lower limit of the glass transition temperature can be, for example, -55°C or higher, -50°C or higher, -45°C or higher, -40°C or higher, -35°C or higher, -30°C or higher, or -25°C or higher, and the upper limit can be, for example, -15°C or lower, -20°C or lower, -25°C or lower, -30°C or lower, or -35°C or lower. When the glass transition temperature range is satisfied, the glass transition temperature can be lowered without significantly reducing the modulus of the polymer matrix, enhancing the mobility (fluidity) of other components in the photopolymer composition, and also improving the moldability of the photopolymer composition. The glass transition temperature can be measured using known methods, such as methods like DSC (Differential Scanning Calorimetry) or DMA (dynamic mechanical analysis).

[0072] The refractive index of the (meth)acrylic polyol can be, for example, 1.40 or higher and less than 1.50. Specifically, the lower limit of the refractive index of the (meth)acrylic polyol can be, for example, 1.41 or higher, 1.42 or higher, 1.43 or higher, 1.44 or higher, 1.45 or higher, or 1.46 or higher, and the upper limit can be, for example, 1.49 or lower, 1.48 or lower, 1.47 or lower, 1.46 or lower, or 1.45 or lower. When the (meth)acrylic polyol has a refractive index in the above-described range, it can contribute to enhancing refractive index modulation. The refractive index of the (meth)acrylic polyol is a theoretical refractive index and can be calculated using the refractive index of the monomers used in the production of the (meth)acrylic polyol (the value measured using an Abbe refractometer at 25°C) and the fraction (molar ratio) of each monomer.

[0073] The (meth)acrylic polyol and the siloxane polymer can be used such that the molar ratio (SiH / OH) of the silane functional group (Si-H) of the siloxane polymer to the hydroxy group (-OH) of the (meth)acrylic polyol is 0.80 to 3.5. That is, when forming the polymer matrix, the types and contents of the siloxane polymer and the (meth)acrylic polyol can be selected so as to satisfy the molar ratio. The lower limit of the molar ratio (SiH / OH) may be, for example, 0.81 or more, 0.85 or more, 0.90 or more, 0.95 or more, 1.00 or more, or 1.05 or more, and the upper limit thereof may be, for example, 3.4 or less, 3.3 or less, 3.2 or less, 3.1 or less, 3.05 or less, or 3.0 or less. When the range of the molar ratio (SiH / OH) is satisfied, the polymer matrix is crosslinked at an appropriate crosslink density, and the reliability under high temperature / high humidity conditions is improved, and a sufficient refractive index modulation value can be realized.

[0074] The Pt-based catalyst may be, for example, Karstedt's catalyst or the like. The precursor of the polymer matrix may additionally contain, if necessary, in addition to the Pt-based catalyst, Rhodium-based, Iridium-based, Rhenium-based, Molybdenum-based, Iron-based, Nickel-based, alkali metal or alkaline earth metal-based, Lewis acids-based or Carbene-based non-metal-based catalysts, etc.

[0075] On the other hand, a hologram recording medium can be manufactured by irradiating an object light and a reference light to a photopolymer layer formed from the photopolymer composition. Due to the interference length of such object light and reference light, photopolymerization of the photoreactive monomer does not occur in the cancellation interference region, and photopolymerization of the photoreactive monomer occurs in the reinforcement interference region. By continuously consuming the photoreactive monomer in the reinforcement interference region, a concentration difference occurs between the photoreactive monomers in the cancellation interference region and the reinforcement interference region. As a result, the photoreactive monomer in the cancellation interference region diffuses into the reinforcement interference region. A diffraction grating is generated by the refractive index modulation thus generated.

[0076] Therefore, the photoreactive monomer can include a compound having a refractive index higher than that of the polymer matrix in order to achieve the refractive index modulation described above. However, it is not limited to the case where all the photoreactive monomers contained in the photopolymer composition have a refractive index higher than that of the polymer matrix, and at least some of the photoreactive monomers can have a refractive index higher than that of the polymer matrix so as to achieve a high refractive index modulation value. As an example, the photoreactive monomer can include monomers having a refractive index of 1.50 or more, 1.51 or more, 1.52 or more, 1.53 or more, 1.54 or more, 1.55 or more, 1.56 or more, 1.57 or more, 1.58 or more, 1.59 or more, or 1.60 or more and 1.70 or less.

[0077] The photoreactive monomer can include one or more monomers selected from the group consisting of monofunctional monomers having one photoreactive functional group and polyfunctional monomers having two or more photoreactive functional groups. At this time, the photoreactive functional group may be, for example, a (meth)acryloyl group, a vinyl group, or a thiol group. More specifically, the photoreactive functional group may be a (meth)acryloyl group.

[0078] The monofunctional monomer can include, for example, one or more selected from the group consisting of benzyl (meth)acrylate (M1182 of Miwon Co., refractive index 1.5140), benzyl 2-phenylacrylate, phenoxybenzyl (meth)acrylate (M1122 of Miwon Co., refractive index 1.565), phenol (ethylene oxide)(meth)acrylate (phenol(EO)(meth)acrylate; M140 of Miwon Co., refractive index 1.516), phenol (ethylene oxide)2(meth)acrylate (phenol(EO)2(meth)acrylate; M142 of Miwon Co., refractive index 1.510), O-phenylphenol (ethylene oxide)(meth)acrylate (O-phenylphenol(EO)(meth)acrylate; M1142 of Miwon Co., refractive index 1.577), phenylthioethyl (meth)acrylate (M1162 of Miwon Co., refractive index 1.560), and biphenylmethyl (meth)acrylate.

[0079] The polyfunctional monomer is, for example, bisphenol A (ethylene oxide) 2~10 di(meth)acrylate (bisphenol A(EO) 2~10(Meth)acrylate; M240 of Miwon Co., refractive index 1.537, M241 refractive index 1.529, M244 refractive index 1.545, M245 refractive index 1.537, M249 refractive index 1.542, M2100 refractive index 1.516, M2101 refractive index 1.512), bisphenol A epoxy di(meth)acrylate (PE210 of Miwon Co., refractive index 1.557, PE2120A refractive index 1.533, PE2120B refractive index 1.534, PE2020C refractive index 1.539, PE2120S refractive index 1.556), bisfluorenyl (meth)acrylate (HR6022 of Miwon Co., refractive index 1.600, HR6040 refractive index 1.600, HR6042 refractive index 1.600), modified bisphenol fluorenyl (meth)acrylate (HR6060 of Miwon Co., refractive index 1.584, HR6100 refractive index 1.562, HR6200 refractive index 1.530), tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate (M370 of Miwon Co., refractive index 1.508), phenol novolac epoxy (meth)acrylate (SC6300 of Miwon Co., refractive index 1.525) and cresol novolac epoxy (meth)acrylate (SC6400 of Miwon Co., refractive index 1.522, SC6400C refractive index 1.522), and can contain one or more selected from the group consisting of them.

[0080] The photopolymer composition can contain 50 to 300 parts by weight of a photoreactive monomer with respect to 100 parts by weight of the polymer matrix. For example, the lower limit of the content of the photoreactive monomer may be 50 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, or 90 parts by weight or more, and the upper limit thereof may be 300 parts by weight or less, 280 parts by weight or less, 250 parts by weight or less, 220 parts by weight or less, 200 parts by weight or less, 190 parts by weight or less, or 180 parts by weight or less. When the above range is satisfied, it is advantageous for ensuring excellent optical recording characteristics and durability in a high temperature / high humidity environment.

[0081] In this specification, the content of the polymer matrix means the combined content (by weight) of the (meth)acrylic polyol and the siloxane polymer that form the matrix. That is, the content of the polymer matrix means the content including all of the polymer matrix formed by the cross-linking of the (meth)acrylic polyol and the siloxane polymer, and the polymer matrix precursor that is not partially cross-linked.

[0082] The photopolymer composition includes a photoinitiator system. The photoinitiator system can mean a photoinitiator that enables polymerization to be initiated by light, or a combination of a photosensitizer and a coinitiator.

[0083] The photopolymer composition can include a photosensitizer and a coinitiator as the photoinitiator system.

[0084] As the photosensitizer, for example, a photosensitive dye can be used. Specifically, as the photosensitive dye, for example, a silicon rhodamine compound, a sulfonium derivative of ceramidonin, new methylene blue, thioerythrosine triethylammonium, 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, pyrylium iodide, Safranin O, cyanine, methylene blue, Azure A, and BODIPY, one or more selected from the group consisting of can be used.

[0085] As an example, as the photosensitive dye, Cy3 and Cy5 (H-Nu640, manufactured by spectra) can be used as cyanine dyes, or Safranin O can be used.

[0086] The photo-polymer composition can contain the photosensitive dye in the range of 0.01 to 10 parts by weight with respect to 100 parts by weight of the polymer matrix. Specifically, the lower limit of the content of the photosensitive dye may be, for example, 0.05 parts by weight or more, 0.07 parts by weight or more, or 0.10 parts by weight or more, and the upper limit thereof may be, for example, 5 parts by weight or less. When the above range is satisfied, it exhibits an appropriate polymerization reaction rate, which is advantageous for ensuring the desired optical recording characteristics.

[0087] The co-initiator may be an electron donor, an electron acceptor, or a mixture thereof.

[0088] As an example, the photo-polymer composition of the above embodiment can contain an electron donor as the co-initiator. The electron donor can contain, for example, a borate anion represented by the following Chemical Formula 4.

[0089] [Chemical Formula 4] BX 1 X 2 X 3 X 4

[0090] In Chemical Formula 4, X 1 ~X 4 are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, an alkylaryl group having 7 to 30 carbon atoms, or an allyl group, and at least one of X 1 ~X 4 is not an aryl group.

[0091] When the alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, aryl group having 6 to 30 carbon atoms, arylalkyl group having 7 to 30 carbon atoms, alkylaryl group having 7 to 30 carbon atoms, or allyl group is substituted, it may be substituted with one or more selected from the group consisting of halogen and alkoxy groups having 1 to 5 carbon atoms.

[0092] Specifically, X 1 ~X 3 are each independently methyl, ethyl, propyl, n-butyl, n-pentyl, n-hexyl, cyclobutyl, cyclopentyl, cyclohexyl, ethenyl, propenyl, phenyl, methylphenyl, methoxyphenyl, naphthyl, methylnaphthyl or methoxynaphthyl which may be substituted or unsubstituted with halogen, and X 4 may be n-butyl, n-pentyl or n-hexyl. More specifically, the borate anion represented by the chemical formula 4 may be, for example, triphenylbutylborate anion.

[0093] The cation bonded to the borate anion does not absorb light and may be an alkali metal cation or a quaternary ammonium cation. The quaternary ammonium cation means an ammonium cation in which nitrogen (N) is substituted with 4 substituents, and the 4 substituents are each independently an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 6 to 40 carbon atoms, or an alkyl group having 2 to 40 carbon atoms linked via an ester bond (for example, -CH2CH2-O-CO-CH2CH2CH3, etc.).

[0094] As the electron donor, for example, commercially available butyryl choline triphenylbutylborate (Borate V, manufacturer: Spectra group) can be used.

[0095] As an example, the photopolymer composition can include an electron acceptor as a co-initiator. The electron acceptor can include, for example, an onium salt such as a sulfonium salt, an iodonium salt, or a mixture thereof.

[0096] As an example, the electron acceptor can include an iodonium salt. As the electron acceptor, for example, commercially available H-Nu254 (from Spectra) can be used.

[0097] The photopolymer composition can include the co-initiator in the range of 0.05 to 10 parts by weight with respect to 100 parts by weight of the polymer matrix. Specifically, the lower limit of the content of the co-initiator may be, for example, 0.1 part by weight or more, 0.2 part by weight or more, 0.3 part by weight or more, 0.4 part by weight or more, or 0.5 part by weight or more, and the upper limit may be, for example, 5 parts by weight or less. When the above range is satisfied, it is advantageous to show an appropriate polymerization reaction rate and ensure the desired optical recording characteristics.

[0098] The photoinitiator system can include an additional photoinitiator to remove the color of the photosensitive dye and react all of the unreacted photoreactive monomers after light irradiation for recording. Examples of the photoinitiator include imidazole derivatives, bisimidazole derivatives, N-aryl glycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, amine derivatives, diazonium salts, sulfonium salts, iodonium salts, sulfonic acid esters, imide sulfonates, dialkyl-4-hydroxy sulfonium salts, arylsulfonic acid-p-nitrobenzyl esters, silanol-aluminum complexes, (η6-benzene)(η5-cyclopentadienyl)iron(II), benzoin tosylate, 2,5-dinitrobenzyl tosylate, N-tosyl phthalimide, or mixtures thereof, etc. can be used.More specifically, examples of the photoinitiator include 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: Irgacure651 / manufacturer: BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184 / manufacturer: BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (product name: Irgacure369 / manufacturer: BASF), bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium (product name: Irgacure784 / manufacturer: BASF), Ebecryl P-115 (manufacturer: SK entis), Cyracure UVI-6970, Cyracure UVI-6974, Cyracure UVI-6990 (manufacturer: Dow Chemical Co. in USA), Irgacure264, Irgacure250 (manufacturer: BASF), CIT-1682 (manufacturer: Nippon Soda), or a mixture thereof, etc., but are not limited thereto.

[0099] The photopolymer composition contains a fluorine-based compound as a plasticizer. The fluorine-based compound is the fluorine-based compound represented by the chemical formula 1, and detailed description thereof is omitted here.

[0100] The plasticizer can easily achieve refractive index modulation during the production of the hologram recording medium. More specifically, the plasticizer lowers the glass transition temperature of the polymer matrix to improve the fluidity of the photoreactive monomer, has a low refractive index and non-reactive properties, and is uniformly distributed within the polymer matrix. When the unpolymerized photoreactive monomer moves, it can move in the opposite direction and contribute to refractive index modulation. In addition, the plasticizer can also contribute to improving the moldability of the photopolymer composition.

[0101] In order for the fluorine-based compound to perform the functions of the above-described plasticizer, it can have a low refractive index of 1.45 or less. Specifically, the upper limit of the refractive index may be, for example, 1.44 or less, 1.43 or less, 1.42 or less, 1.41 or less, 1.40 or less, 1.40 or less, 1.39 or less, 1.38 or less, or 1.37 or less, and the lower limit of the refractive index may be, for example, 1.30 or more, 1.31 or more, 1.32 or more, 1.33 or more, 1.34 or more, or 1.35 or more. By using a fluorine-based compound having a refractive index lower than that of the above-described photoreactive monomer, the refractive index of the polymer matrix can be made lower, and the refractive index modulation with the photoreactive monomer can be made larger.

[0102] By including the fluorine-based compound represented by the chemical formula 1, the photopolymer composition can provide a hologram recording medium having excellent optical recording characteristics, as well as excellent reliability and high transparency optical characteristics even in a high temperature / high humidity environment.

[0103] More specifically, the fluorine-based compound represented by Chemical Formula 1 exhibits sufficient low refractive index, increasing the refractive index modulation with the photoreactive monomer and fully playing the role of a basic plasticizer that improves the diffusibility of the components in the photopolymer composition. Moreover, the fluorine-based compound represented by Chemical Formula 1 has little migration to the surface of the photopolymer layer not only at high temperatures but also in a high-humidity environment, is resistant to heat and moisture, and does not easily decompose even under high-temperature / high-humidity conditions, thus improving the reliability in a high-temperature / high-humidity environment. In addition, the fluorine-based compound represented by Chemical Formula 1 exhibits excellent compatibility with components having a high refractive index, ensuring optical properties with high transparency due to excellent heat and moisture resistance.

[0104] In Chemical Formula 1, when the fluorine-containing substituent is, for example, -(CH2) a (CF2) b CHF2, -(CH2) a (CF2) b CF3 or a decafluorocyclohexyl group, it is possible to provide a hologram recording medium that contributes to increasing the refractive index modulation while having low haze.

[0105] The photopolymer composition can contain 20 to 200 parts by weight of the fluorine-based compound with respect to 100 parts by weight of the polymer matrix. Specifically, the lower limit of the content of the fluorine-based compound may be, for example, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, 45 parts by weight or more, 50 parts by weight or more, or 55 parts by weight or more, and the upper limit may be, for example, 200 parts by weight or less, 180 parts by weight or less, 150 parts by weight or less, 120 parts by weight or less, or 100 parts by weight or less. When the above range is satisfied, there are no problems such as poor compatibility with the components contained in the photopolymer composition, resulting in elution of some fluorine-based compounds to the surface of the photopolymer layer or poor haze. With a fluorine-based compound having a sufficient low refractive index, it is possible to exhibit a large refractive index modulation value after recording, which is advantageous for ensuring excellent optical recording characteristics.

[0106] The photo-polymer composition can additionally contain additives such as an antifoaming agent.

[0107] The photo-polymer composition can contain a silicone-based reactive additive as an antifoaming agent. As the silicone-based reactive additive, commercially available products such as Tego Rad2500 can be used, for example.

[0108] The content of the additive, for example, the antifoaming agent can be appropriately adjusted to a level that does not interfere with the function of the hologram recording medium.

[0109] The photo-polymer composition can additionally contain a solvent.

[0110] The solvent may be an organic solvent, and as an example, it may be one or more organic solvents selected from the group consisting of ketones, alcohols, acetates, and ethers, but is not limited thereto. Specific examples of such organic solvents include ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, or 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; and one or more selected from the group consisting of ethers such as tetrahydrofuran or propylene glycol monomethyl ether.

[0111] The organic solvent may be added when the components contained in the photo-polymer composition are mixed, or may be added in a state where the components are dispersed or mixed in the organic solvent and then contained in the photo-polymer composition.

[0112] The photo-polymer composition can contain a solvent such that the concentration of the solid content is 1 to 90% by weight. Specifically, the photo-polymer composition can contain a solvent such that the concentration of the solid content is 20% by weight or more, 30% by weight or more, 50% by weight or more, or 60% by weight or more, and 85% by weight or less, 80% by weight or less, 75% by weight or less, or 70% by weight or less. Within such a range, the photo-polymer composition exhibits appropriate fluidity and can form a coating film without defects such as streaks, and no defects occur during its drying and curing processes, and a photo-polymer layer having desired physical properties and surface characteristics can be formed.

[0113] On the other hand, according to still another embodiment of the invention, there is provided a hologram recording medium including a photo-polymer layer formed from the photopolymerizable composition.

[0114] As used herein, the term "hologram recording medium" means a medium (medium or media) capable of recording optical information in the entire visible light range and ultraviolet range (e.g., 300 to 1,200 nm) during an exposure process, unless otherwise specified. For example, the holograms in this specification may all include visual holograms such as in-line (Gabor) holograms, off-axis holograms, full-aperture transfer holograms, white light transmission holograms ("rainbow holograms"), Denisyuk holograms, off-axis reflection holograms, edge-literature holograms, or holographic stereograms.

[0115] By being formed from the photopolymerizable composition (photo-polymer composition), the photo-polymer layer can ensure excellent optical recording characteristics by showing a large refractive index modulation value and high diffraction efficiency despite its thin thickness, and can show excellent reliability even in a high temperature / high humidity environment.

[0116] The thickness of the photopolymer layer may be, for example, in the range of 5.0 to 40.0 μm. Specifically, the lower limit of the thickness of the photopolymer layer may be, for example, 6 μm or more, 7 μm or more, 8 μm or more, or 9 μm or more. And the upper limit of the thickness may be, for example, 35 μm or less, 30 μm or less, 29 μm or less, 28 μm or less, 27 μm or less, 26 μm or less, 25 μm or less, 24 μm or less, 23 μm or less, 22 μm or less, 21 μm or less, 20 μm or less, 19 μm or less, or 18 μm or less.

[0117] The hologram recording medium can further include a substrate on at least one surface of the photopolymer layer. The type of the substrate is not particularly limited, and those known in the related technical field can be used. For example, substrates such as glass, PET (polyethylene terephthalate), TAC (triacetyl cellulose), PC (polycarbonate), and COP (cycloolefin polymer) can be used.

[0118] The hologram recording medium can have a high diffraction efficiency. As an example, when the hologram recording medium records a Notch filter hologram, it can have a diffraction efficiency of 70% or more. At this time, the thickness of the photopolymer layer may be, for example, 5 to 30 μm. Specifically, when the Notch filter hologram is recorded, the diffraction efficiency may be 75% or more, 80% or more, 85% or more, 86% or more, 87% or more, or 88% or more. Thus, the hologram recording medium can achieve excellent diffraction efficiency even when including a photopolymer layer with a thin thickness. The diffraction efficiency can be measured by the method described in the test examples below.

[0119] Even if the thickness of the hologram recording medium is as thin as 5 to 30 μm, a refractive index modulation value (Δn) of 0.020 or more, 0.025 or more, 0.026 or more, 0.027 or more, 0.028 or more, 0.029 or more, 0.030 or more, 0.031 or more, 0.032 or more, 0.033 or more, 0.034 or more, or 0.035 or more can be realized. The upper limit of the refractive index modulation value is not particularly limited, and for example, it may be 0.060 or less. The refractive index modulation value can be measured by the method described in the test examples below.

[0120] The hologram recording medium can exhibit excellent durability in a high-temperature / high-humidity environment. As an example, the hologram recording medium may have a peak variation calculated by the following formula 3 of 3% or less.

[0121] [Formula 3] Peak variation = {|1 - A1 / A0|} × 100

[0122] In the above formula 3, A0 is the wavelength of the minimum transmittance of the hologram recording medium in the wavelength range of 300 to 1,200 nm, and A1 is the wavelength of the minimum transmittance measured after exposing the hologram recording medium to a temperature of 60°C and a relative humidity of 90% for 72 hours.

[0123] The fact that the peak variation calculated by the above formula 3 is 3% or less means that the deformation (shrinkage or expansion) of the diffraction grating can be suppressed so as to have a peak variation of 3% or less even when exposed to severe conditions such as high temperature / high humidity. Such a hologram recording medium can provide good color reproducibility and image sharpness even when exposed to severe conditions.

[0124] The peak variation with respect to the hologram recording medium may be, for example, 2.5% or less, 2.0% or less, 1.9% or less, 1.8% or less, 1.7% or less, 1.6% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, or 1.1% or less. The lower limit of the peak variation is not particularly limited and may be 0% or more.

[0125] The hologram recording medium of the other embodiment has high durability against heat and moisture and can exhibit high adhesive strength even after being aged in a high temperature / high humidity environment.

[0126] As an example, the hologram recording medium of the other embodiment is stored for 72 hours at a temperature of 60°C and a relative humidity of 90% in a state where a photopolymer layer is laminated so as to contact an optically transparent adhesive layer, and then measured under the conditions of a peeling angle of 180° and a peeling speed of 5 mm / sec. The adhesive strength may be 500 gf / 2.5 cm or more.

[0127] The type of the optically transparent adhesive layer is not particularly limited, and for example, it may be a rubber-based adhesive layer, an acrylic-based adhesive layer, or a silicone-based adhesive layer. The hologram recording medium of the other embodiment is not limited to exhibiting excellent adhesive strength to all types of adhesive layers. However, the hologram recording medium of the other embodiment can exhibit excellent adhesive strength to various types of adhesive layers.

[0128] The lower limit of the adhesive strength may be, for example, 530 gf / 2.5 cm or more, 550 gf / 2.5 cm or more, 600 gf / 2.5 cm or more, 700 gf / 2.5 cm or more, 800 gf / 2.5 cm or more, 850 gf / 2.5 cm or more, 900 gf / 2.5 cm or more, 950 gf / 2.5 cm or more, 1000 gf / 2.5 cm or more, 1020 gf / 2.5 cm or more, 1050 gf / 2.5 cm or more, or 1100 gf / 2.5 cm or more. The method for measuring the adhesive strength can refer to the method described in the test examples to be described later. The upper limit of the adhesive strength is not particularly limited and may be 2500 gf / 2.5 cm or less.

[0129] On the other hand, since the hologram recording medium is used by mixing a component having a low refractive index and a component having a high refractive index for optical property recording, it tends to have an opaque property due to the compatibility of these. However, the hologram recording medium can exhibit an optical property of high transparency by using a fluorine-based compound having a specific structure with excellent compatibility.

[0130] As an example, the haze of the hologram recording medium may be 2% or less. The upper limit of the haze may be, for example, 1.7% or less, 1.6% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1.0% or less, 0.9% or less, 0.8% or less, or 0.7% or less. The lower limit of the haze is not particularly limited and may be 0% or more. The haze can be measured by the method described in the test examples described later.

[0131] The hologram recording medium is expected to provide various optical elements that not only exhibit excellent optical recording characteristics and excellent durability in a high-temperature / high-humidity environment but also have high transparency optical characteristics and can be used in environments with a lot of heat generation or high humidity.

[0132] The hologram recording medium is not limited to this, but may be one on which a reflection hologram or a transmission hologram is recorded.

[0133] As an example, the diffraction grating included in the photopolymer layer may be a reflection hologram grating. In the case of a transmission hologram grating, since the diffraction grating is formed in a direction perpendicular to the plane of the substrate, the linear expansion rate of the substrate and the linear expansion rate of the photopolymer have a great influence on the deformation of the grating. In contrast, since the reflection hologram grating is formed in a direction horizontal to the plane of the substrate, the expansion or contraction of the volume hologram grating formed inside the photopolymer has a greater influence on the sharpness of the image than the linear expansion rate mismatch between the substrate and the diffraction grating. Accordingly, such a hologram recording medium having such peak variation characteristics is more suitable for a reflection hologram.

[0134] As an example, the diffraction grating included in the photopolymer layer may be formed in a direction parallel to or horizontal to the bottom surface on which the substrate is placed. At this time, parallel or horizontal means substantially parallel or horizontal, and it can be meant that the fringe angle of the diffraction grating with respect to the bottom surface on which the substrate is placed is within an error range of ±5°, ±4°, ±3°, ±2° or ±1° and is parallel or horizontal.

[0135] The hologram recording medium can have a notch filter structure in relation to the diffraction grating structure. That the hologram recording medium has a notch filter structure can mean, for example, that the diffraction grating is non-slanted (substantially 0°) with respect to the substrate surface, such as when the diffraction grating is parallel to the substrate surface. Such a hologram recording medium can have a structure in which two layers with different refractive indices (e.g., a high refractive index layer and a low refractive index layer) are alternately repeated. And the two repeated layers can each have a predetermined thickness that is the same as or different from each other. The recording of such a non-slanted diffraction grating can be manufactured by a method in which the incident angles of the object light and the reference light are made the same with respect to the normal line. In a non-slanted structure, the degree of deformation (e.g., shrinkage or expansion) under high temperature / high humidity conditions can be more clearly confirmed than in a slanted structure, and it is also less affected by the shrinkage and expansion of the substrate.

[0136] The use of the hologram recording medium is not particularly limited. As a non-limiting example, the hologram recording medium can be used in applications that are likely to be exposed to a high temperature / high humidity environment, specifically, smart devices such as mobile devices, components of wearable displays, or automotive components (e.g., head up display).

[0137] According to yet another embodiment of the invention, there is provided a method for manufacturing a hologram recording medium, including the steps of: applying the photopolymerizable composition to form a photopolymer layer; and irradiating a predetermined region of the photopolymer layer with an interferable laser to selectively polymerize the photoreactive monomer contained in the photopolymer layer to record optical information.

[0138] The photopolymerizable composition may be the photopolymer composition of the above-described embodiment. Since the photopolymer composition has been described in detail above, detailed description thereof is omitted herein.

[0139] In the step of forming the photopolymer layer, first, a photopolymer composition including the above-described configuration can be manufactured. When manufacturing the photopolymer composition, for mixing of each component, commonly known mixers, stirrers, or mixers can be used without any limitation. And such a mixing process may be performed at a temperature in the range of 0°C to 100°C, a temperature in the range of 10°C to 80°C, or a temperature in the range of 20°C to 60°C.

[0140] In the step of forming the photopolymer layer, the prepared photopolymer composition can be applied to form a coating film formed from the photopolymer composition. The coating film may be naturally dried at room temperature or dried at a temperature in the range of 30 to 80°C. By this process, a hydrosilylation reaction between the hydroxy group of the (meth)acrylic polyol remaining without reacting and the silane functional group of the siloxane polymer can be induced.

[0141] In the photopolymer layer manufactured by the step of forming the photopolymer layer, a fluorine-based compound, a photoreactive monomer and a photoinitiator system, additives added as necessary, etc. may be uniformly dispersed in the crosslinked polymer matrix.

[0142] Thereafter, when the photopolymer layer is irradiated with an interferable laser at the stage of recording optical information, polymerization of the photoreactive monomer occurs in the region where constructive interference occurs, forming a photopolymer, and in the region where destructive interference occurs, polymerization of the photoreactive monomer does not occur or is suppressed, and the photoreactive monomer exists. Then, the non-reacting photoreactive monomer diffuses to the photopolymer side where the concentration of the photoreactive monomer is low, causing a refractive index modulation, and a diffraction grating is generated by the refractive index modulation. Thereby, a hologram, that is, optical information is recorded in the photopolymer layer having the diffraction grating.

[0143] The method for manufacturing the hologram recording medium may additionally include a step of photobleaching by irradiating the entire photopolymer layer with light after the step of recording optical information.

[0144] In the photobleaching step, the photoreactive monomer remaining in the photopolymer layer can be terminated by irradiating the photopolymer layer with ultraviolet light, and the color of the photosensitive dye can be removed. As an example, in the photobleaching step, ultraviolet light (UVA) in the region of 320 to 400 nm can be irradiated to terminate the reaction of the photoreactive monomer and remove the color of the photosensitive dye.

[0145] On the other hand, according to still another embodiment of the invention, an optical element including the hologram recording medium is provided.

[0146] Specific examples of the optical element include smart devices such as mobile devices, components of wearable displays, vehicle supplies (e.g., head up display), holographic fingerprint recognition systems, optical lenses, mirrors, deflecting mirrors, filters, diffusion screens, diffraction members, light conductors, waveguides, holographic optical elements having functions of projection screens and / or masks, media of optical memory systems and light diffusing plates, optical wavelength dividers, reflective and transmissive color filters, and the like.

[0147] An example of the optical element including the hologram recording medium includes a hologram display device. The hologram display device includes a light source unit, an input unit, an optical system, and a display unit.

[0148] Specifically, the light source unit is a part that irradiates a laser beam used to provide, record, and reproduce three-dimensional video information of an object in the input unit and the display unit.

[0149] The input unit is a part that pre-inputs three-dimensional video information of an object to be recorded in the display unit. Specifically, three-dimensional information of an object such as the intensity and phase of light for each space can be input to an electrically addressed liquid crystal SLM, and at this time, it is a part where an input beam can be used.

[0150] The optical system may be composed of a mirror, a polarizer, a beam splitter, a beam shutter, a lens, etc. The optical system can distribute a laser beam emitted from the light source unit to an input beam sent to the input unit, a recording beam sent to the display unit, a reference beam, an erasing beam, a readout beam, etc.

[0151] The display unit can receive three-dimensional video information of an object from the input unit, record it on a hologram plate composed of an optically addressed SLM, and reproduce the three-dimensional video of the object. At this time, three-dimensional video information of the object can be recorded by the interference of the input beam and the reference beam. The three-dimensional video information of the object recorded on the hologram plate can be reproduced as a three-dimensional video by the diffraction pattern generated by the readout beam, and the erasing beam can be used to quickly remove the formed diffraction pattern. On the other hand, the hologram plate can move between the position where the three-dimensional video is input and the position where it is reproduced.

Advantages of the Invention

[0152] According to an embodiment of the invention, the fluorine-based compound is included in a photopolymerizable composition, and can provide a hologram recording medium having excellent optical recording characteristics, as well as excellent transparency and reliability even in high-temperature and high-humidity environments, and an optical element including the same.

Brief Description of the Drawings

[0153]

Figure 1

Modes for Carrying Out the Invention

[0154] Hereinafter, the actions and effects of the invention will be described more specifically through specific examples of the invention. However, this is presented as an example of the invention, and the scope of the rights of the invention is not limited in any way thereby.

[0155] In the following production examples, examples, and comparative examples, etc., the content of raw materials, etc. means the content based on solid matter, unless otherwise specified.

[0156] Production Example 1: Production of Fluorine-Based Compound 200 g of malonic acid, 900 g of 2,2,3,3,4,4,5,5 - octafluoro - 1 - pentanol, and 800 mL of toluene were placed in a 2L jacketed reactor and refluxed. After about 1 hour, 19 mL of sulfuric acid (H2SO4) was added dropwise. A Dean - Stark Trap was installed to remove the generated water and maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, water was added for washing, and then the organic layer was concentrated. 800 g of an intermediate product was obtained by high - vacuum distillation.

[0157] 800 g of the obtained intermediate product, 437 g of potassium carbonate, 28 g of tetra - n - butylammonium iodide, 525 g of 2 - bromoethyl methyl ether, and 800 mL of dimethylformamide were placed in a 2L jacketed reactor and maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, 800 mL of chloroform was added, stirred, and then filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and then the organic layer was concentrated. 800 g of a fluorine - based compound represented by the following chemical formula a was obtained by high - vacuum distillation.

[0158] [Chemical formula a] [Chemical formula]

[0159] Production Example 2: Production of Fluorine - based Compound 200 g of malonic acid, 820 g of 2,2,3,3,4,4,5,5,6,6 - decafluoro - 1 - hexanol, and 800 mL of toluene were placed in a 2L jacketed reactor and refluxed. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean - Stark Trap was installed to remove the generated water and maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, water was added for washing, and then the organic layer was concentrated. 600 g of an intermediate product was obtained by high - vacuum distillation.

[0160] Into a 2 L jacketed reactor, 600 g of the obtained intermediate product, 276 g of potassium carbonate, 18 g of tetra-n-butylammonium iodide, 330 g of 2-bromoethyl methyl ether, and 600 mL of dimethylformamide were added, and the temperature was maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, then 800 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and then the organic layer was concentrated. 500 g of the fluorine-based compound represented by the following chemical formula b was obtained by high-vacuum distillation.

[0161] [Chemical formula b] [Chemical formula]

[0162] Production Example 3: Production of Fluorine-based Compound Into a 2 L jacketed reactor, 200 g of malonic acid, 820 g of 2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol, and 800 mL of toluene were added, and a reflux reaction was carried out. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean-Stark Trap was provided to remove the generated water, and the reaction was maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, then water was added for washing, and the organic layer was concentrated. 600 g of the intermediate product was obtained by high-vacuum distillation.

[0163] Into a 2 L jacketed reactor, 600 g of the obtained intermediate product, 276 g of potassium carbonate, 18 g of tetra-n-butylammonium iodide, 435 g of 1-bromo-2-(2-methoxyethoxy)ethane, and 600 mL of dimethylformamide were added, and the temperature was maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, then 800 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and then the organic layer was concentrated. 490 g of the fluorine-based compound represented by the following chemical formula c was obtained by high-vacuum distillation.

[0164] [Chemical formula c] [Chem.]

[0165] Production Example 4: Production of Fluorine-based Compound Into a 2 L jacketed reactor, 200 g of malonic acid, 815 g of 2,2,3,3,4,4,5,5,6,6-decafluorohexan-1-amine, and 800 mL of toluene were charged and refluxed. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean-Stark Trap was installed to remove the generated water, and the reaction was maintained for 24 hours. After completion of the reaction, it was cooled to room temperature, water was added, washed with water, and the organic layer was concentrated. 600 g of an intermediate product was obtained by high-vacuum distillation.

[0166] Into a 2 L jacketed reactor, 600 g of the obtained intermediate product, 277 g of potassium carbonate, 18 g of tetra-n-butylammonium iodide, 436 g of 1-bromo-2-(2-methoxyethoxy)ethane, and 600 mL of dimethylformamide were charged and maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, 800 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and the organic layer was concentrated. 500 g of a fluorine-based compound represented by the following chemical formula d was obtained by high-vacuum distillation.

[0167] [Chemical formula d] [Chem.]

[0168] Production Example 5: Production of Fluorine-based Compound 200 g of malonic acid, 410 g of 2,2,3,3,4,4,5,5,6,6 - decafluoro - 1 - hexanol, and 800 mL of toluene were placed in a 2L jacketed reactor and refluxed. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean - Stark Trap was installed to remove the generated water, and the reaction was maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, then 2 - (2 - methoxyethoxy) - 1 - ethanol was added and the mixture was refluxed. After the reaction was completed, it was cooled to room temperature, water was added, and after washing with water, the organic layer was concentrated. 450 g of the intermediate product was obtained by high - vacuum distillation.

[0169] 450 g of the obtained intermediate product, 278 g of potassium carbonate, 18 g of tetra - n - butylammonium iodide, 438 g of 1 - bromo - 2 - (2 - methoxyethoxy)ethane, and 600 mL of dimethylformamide were placed in a 2L jacketed reactor and maintained at 90°C. After reacting for 24 hours, it was cooled to room temperature, then 800 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and then the organic layer was concentrated. 420 g of the fluorine - based compound represented by the following chemical formula e was obtained by high - vacuum distillation.

[0170] [Chemical formula e] [Chemical formula]

[0171] Production Example 6: Production of Fluorine - based Compound 200 g of malonic acid, 820 g of 2,2,3,3,4,4,5,5,6,6 - decafluoro - 1 - hexanol, and 800 mL of toluene were placed in a 2L jacketed reactor and refluxed. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean - Stark Trap was installed to remove the generated water, and the reaction was maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, water was added for washing, and then the organic layer was concentrated. 600 g of the intermediate product was obtained by high - vacuum distillation.

[0172] 600 g of the obtained intermediate product, 276 g of potassium carbonate, 18 g of tetra - n - butylammonium iodide, 174 g of 1 - bromo - 2 - (2 - methoxyethoxy)ethane, and 600 mL of dimethylformamide were placed in a 2L jacketed reactor and maintained at 90°C. After reacting for 24 hours, it was cooled to room temperature, 284 g of 1 - bromo - 1,{1,2,2,3,3,4,4,4 - nonafluorobutane was added, and the temperature was maintained at 90°C. After reacting for 24 hours, it was cooled to room temperature, 800 mL of chloroform was added, stirred, and then filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and then the organic layer was concentrated. 300 g of the fluorine - based compound represented by the following chemical formula f was obtained by high - vacuum distillation.

[0173] [Chemical formula f] [Chemical formula]

[0174] Production Example 7: Production of Fluorine - Based Compound 200 g of malonic acid, 820 g of 2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol, and 800 mL of toluene were placed in a 2L jacketed reactor and refluxed. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean-Stark Trap was provided to remove the generated water and maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, water was added, washed with water, and the organic layer was concentrated. 600 g of the intermediate product was obtained by high-vacuum distillation.

[0175] 400 g of the obtained intermediate product, 184 g of potassium carbonate, 12 g of tetra-n-butylammonium iodide, 473 g of 1-bromo-1,1,2,2,3,3,4,4,4-nonafluorobutane, and 600 mL of dimethylformamide were placed in a 2L jacketed reactor and maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, 400 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 800 mL of 3% hydrochloric acid, and the organic layer was concentrated. 450 g of the fluorine-based compound represented by the following chemical formula g was obtained by high-vacuum distillation.

[0176] [Chemical formula g] [Chemical formula]

[0177] Production Example 8: Production of Fluorine-Based Compound 200 g of malonic acid, 410 g of 2,2,3,3,4,4,5,5,6,6 - decafluoro - 1 - hexanol, and 800 mL of toluene were added to a 2 L jacket reactor, and reflux reaction was carried out. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean - Stark Trap was provided to remove the generated water, and the reaction was maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, then 2 - methoxyethanol was added, and reflux reaction was carried out. After the reaction was completed, it was cooled to room temperature, then water was added, washed with water, and the organic layer was concentrated. 450 g of the intermediate product was obtained by high - vacuum distillation.

[0178] 400 g of the obtained intermediate product, 273 g of potassium carbonate, 18 g of tetra - n - butylammonium iodide, 172 g of 1 - bromo - 2 - (2 - methoxyethoxy)ethane, and 600 mL of dimethylformamide were added to a 2 L jacket reactor, and the temperature was maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, then 281 g of 1 - bromo - 1,1,2,2,3,3,4,4,4 - nonafluorobutane was added, and the temperature was maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, then 800 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 1600 mL of 3% hydrochloric acid, and the organic layer was concentrated. 320 g of the fluorine - based compound represented by the following chemical formula h was obtained by high - vacuum distillation.

[0179] [Chemical formula h] [Chemical formula]

[0180] Production Example 9: Production of Fluorine - based Compound 200 g of malonic acid, 410 g of 2,2,3,3,4,4,5,5,6,6 - decafluoro - 1 - hexanol, and 800 mL of toluene were added to a 2L jacket reactor and refluxed. After about 1 hour, 14 mL of sulfuric acid (H2SO4) was added dropwise. A Dean - Stark Trap was installed to remove the generated water and maintained for 24 hours. After the reaction was completed, it was cooled to room temperature, then 2 - (2 - methoxyethoxy) - 1 - ethanol was added and refluxed. After the reaction was completed, it was cooled to room temperature, water was added, washed with water, and the organic layer was concentrated. 450 g of the intermediate product was obtained by high - vacuum distillation.

[0181] 400 g of the obtained intermediate product, 273 g of potassium carbonate, 18 g of tetra - n - butylammonium iodide, 700 g of 1 - bromo - 1,1,2,2,3,3,4,4,4 - nonafluorobutane, and 600 mL of dimethylformamide were added to a 2L jacket reactor and maintained at 90 °C. After reacting for 24 hours, it was cooled to room temperature, then 400 mL of chloroform was added, stirred, and filtered. The filtered filtrate was washed with 800 mL of 3% hydrochloric acid, and the organic layer was concentrated. 520 g of the fluorine - based compound represented by the following chemical formula i was obtained by high - vacuum distillation.

[0182] [Chemical formula i] [Chemistry]

[0183] Production Example 10: Production of (meth)acrylic polyol 132 g of butyl acrylate, 420 g of ethyl acrylate, and 48 g of hydroxybutyl acrylate were placed in a 2 L jacketed reactor and diluted with 1200 g of ethyl acetate. The reaction temperature was set to 60 - 70 °C, and stirring was carried out for about 30 minutes to 1 hour. Additionally, 0.42 g of n-dodecyl mercaptan (n-DDM) was added, and stirring was further carried out for about 30 minutes. Thereafter, 0.24 g of AIBN, which is a polymerization initiator, was added, and polymerization was carried out at the reaction temperature for 4 hours or more, maintained until the content of residual acrylate was less than 1%, to produce a (meth)acrylate copolymer in which the hydroxy group was located in the branched chain (weight average molecular weight of about 300,000, OH equivalent of about 1802 g / equivalent).

[0184] Example 1: Production of Photopolymer Composition and Hologram Recording Medium (1) Production of Photopolymer Composition First, 1.27 g of poly(methylhydrosiloxane) (manufactured by Sigma - Aldrich, number average molecular weight: about 390, Si - H equivalent of about 103 g / equivalent), which is a siloxane - based polymer, and 11.12 g of the (meth)acrylic polyol produced in Production Example 10 were mixed (SiH / OH molar ratio = 2.0).

[0185] Then, 20 g of HR6042 (Miwon, refractive index 1.60) as a photoreactive monomer, 0.08 g of photosensitive dye H - Nu640 (Spectra), 0.3 g of Borate V as a co - initiator, 0.05 g of H - Nu254 (Spectra), 10 g of the fluorine - based compound produced in Production Example 1 as a plasticizer, and 26 g of methyl isobutyl ketone (MIBK) as a solvent were added, and stirred with a Paste mixer for about 30 minutes in a light - blocked state. Thereafter, a Karstedt (Pt - based) catalyst was added for matrix cross - linking to produce a photopolymer composition.

[0186] (2) Production of Hologram Recording Medium The photopolymer composition was coated to a predetermined thickness on a TAC substrate with a thickness of 60 μm using a Mayer bar and dried at 80°C for 10 minutes. After drying, the thickness of the photopolymer layer was about 15 μm.

[0187] A diffraction grating was recorded using the setup as shown in FIG. 1. Specifically, after laminating the produced photopolymer layer on a mirror and irradiating it with a laser, a Notch filter hologram having a periodic refractive index modulation in the thickness direction can be recorded due to the interference between the incident light L and the light L' reflected by the mirror. In this example, the Notch filter hologram was recorded with an incident angle of 0° (degree). Notch filter and Bragg reflector are optical elements that reflect only light of a specific wavelength and have a structure in which two layers with a refractive index difference are periodically laminated at a constant thickness.

[0188] Examples 2 to 9 and Comparative Examples 1 to 3: Production of Photopolymer Composition and Hologram Recording Medium A photopolymer composition and a hologram recording medium were produced in the same manner as in Example 1, except that the components and contents of the photopolymer composition were varied as described in Table 1 below. <x

[0189] [Table 1]

[0190] [Chemical formula j] [Chemical structure]

[0191] [Chemical formula k] [Chemical structure]

[0192] [Chemical formula l] [Chemical structure]

[0193] Test Example: Performance Evaluation of Hologram Recording Medium (1) Diffraction Efficiency The diffraction efficiency (η) was determined by the following Equation 1.

[0194] [Equation 1] η(%) = {P D / (P D + P T )} X 100

[0195] In Equation 1 above, η is the diffraction efficiency, and P D is the output power (mW / cm 2 ) of the diffracted beam of the sample after recording, and P T is the output power (mW / cm 2 ) of the transmitted beam of the sample after recording.

[0196] (2) Refractive Index Modulation Value (Δn) The refractive index modulation value (Δn) was determined by the following Equation 2 and Bragg's equation.

[0197] [Equation 2] [Number]

[0198] [Bragg's equation] [Number]

[0199] In the above formula, η is the reflectivity diffraction efficiency (DE), d is the thickness of the photopolymer layer, λ is the wavelength of the incident light for recording (660 nm or 532 nm), θ is the incident angle of the incident light for recording, Φ is the slant angle of the grating, Δn is the refractive index modulation value, n is the refractive index of the photopolymer, and Λ means the period of the diffraction grating. In the above examples and comparative examples, since the hologram was recorded by the Notch filter method, θ (incident angle) and Φ (slant angle of the grating) are all 0°.

[0200] (3) Haze The haze was measured using a HAZE METER (Murakami Color Research Laboratory, HM-150) in accordance with JIS K7136. The measurement light was incident on the side surface of the substrate of the hologram recording medium.

[0201] (4) Peak variation First, a specific wavelength (or wavelength band) (A0) having the maximum reflectivity (i.e., the minimum transmittance) shown by the sample on which the diffraction grating was recorded was analyzed (analyzed under normal temperature and non-high humidity conditions). A UV-Vis spectrometer was used for the above analysis, and the analysis wavelength range was 300 to 1,200 nm.

[0202] Thereafter, the same sample was stored at a temperature of 60 °C and a relative humidity of 90% for 72 hours, and the wavelength (or wavelength band) (A1) having the maximum reflectivity (minimum transmittance) was recorded in the same manner. The peak variation, which is the degree of movement of the wavelength having the minimum transmittance before and after the evaluation, was measured by the following formula 3. At this time, it was assumed that the deformation (for example, shrinkage or expansion) of the sample did not affect the surface grating (pitch) and occurred only in the direction perpendicular to the sample surface.

[0203] [Formula 3] Peak variation = {|1 - A1 / A0|} X 100

[0204] (5) Adhesion after aging After laminating tesa (registered trademark) 61563 (thickness: 50 μm, manufactured by TESA) as a rubber-based OCA (optically clear adhesive) on a glass substrate to form an adhesive layer, the photopolymer layer of the sample on which a diffraction grating was recorded was laminated so as to contact the adhesive layer. Thereafter, the obtained sample was cut to a width of 2.5 cm to prepare a sample in which a glass substrate, an adhesive layer, a photopolymer layer, and a TAC substrate were laminated in this order.

[0205] After storing the prepared sample at a temperature of 60 °C and a relative humidity of 90% for 72 hours, the adhesive force between the photopolymer layer and the adhesive layer was measured using a Texture Analyzer. The peeling angle during the adhesive force measurement was 180°, and the peeling speed was 5 mm / sec.

[0206]

Table 2

[0207] Referring to Table 2 above, the hologram recording media manufactured in Examples 1 to 9 show excellent diffraction efficiency, refractive index modulation value, and low haze, and after being exposed to a high-temperature / high-humidity environment, there is little change in the wavelength showing the maximum reflectance, and it shows a high adhesive force and excellent reliability in a high-temperature / high-humidity environment. In contrast, the hologram recording media manufactured in Comparative Example 2 are all inferior in optical recording characteristics, haze, and reliability in a high-temperature / high-humidity environment, and the hologram recording media manufactured in Comparative Examples 1 and 3 show excellent optical recording characteristics but poor reliability in a high-temperature / high-humidity environment.

[0208] Thus, it is confirmed that by using a fluorine-based compound according to an embodiment of the invention, a hologram recording media having excellent optical recording characteristics, excellent reliability even in a high-temperature / high-humidity environment, and high transparency can be provided.

Claims

1. A fluorine-based compound represented by the following chemical formula 1: [Chemical formula 1] 【Chemical 1】 In the above chemical formula 1, Z １ and Z ２ are each independently —O—, —S— or —NH—, R １ to R ４ At least one or more of them are fluorine-containing substituents, which are alkyl groups having 1 to 20 carbon atoms substituted with 2 or more fluorines, cycloalkyl groups having 3 to 30 carbon atoms substituted with 2 or more fluorines, or aryl groups having 6 to 30 carbon atoms substituted with 2 or more fluorines, R １ ~R ４ When R and ~R are not fluorine-containing substituents, each is independently a substituent selected from an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a heterocycloalkyl group having 4 to 30 carbon atoms, a cycloalkylalkyl group having 7 to 40 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 4 to 30 carbon atoms, or an arylalkyl group having 7 to 40 carbon atoms, or a substituent in which one or more -CH ２ - is replaced by -O-, -S-, or -NH-.

2. R in the above Chemical Formula 1 １ The fluorine-based compound according to claim 1, wherein １ is a fluorine-containing substituent.

3. The fluorine-containing substituent is a linear alkyl group having 1 to 20 carbon atoms substituted with 2 or more fluorines, a cycloalkyl group having 3 to 12 carbon atoms substituted with 2 or more fluorines, or an aryl group having 6 to 14 carbon atoms substituted with 2 or more fluorines. The fluorine-based compound according to Claim 1.

4. The fluorine-containing substituent is -(CH ２ ) ａ (CF ２ ) ｂ CHF ２ , -(CH ２ ) ａ (CF ２ ) ｂ CF ３ or a decafluorocyclohexyl group, a is an integer of 0 to 3, and b is an integer of 0 to 19. The fluorine-based compound according to claim 1.

5. In the above Chemical Formula 1, R １ ~R ４ is not a fluorine-containing substituent, R １ ~R ４ are each independently a linear alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a heterocycloalkyl group having 4 to 12 carbon atoms, an aryl group having 6 to 14 carbon atoms, a heteroaryl group having 4 to 12 carbon atoms, an arylalkyl group having 7 to 16 carbon atoms, or -(R ５ -Y １ ) ｃ -R ６ ; and R ５ is an alkylene group having 1 to 6 carbon atoms, and R ６ is an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms, Y １ is -O- or -S-, c is an integer of 1 to 12, and when c is 2 or more, R ５ are the same as or different from each other, the fluorine-based compound according to claim 1.

6. The fluorine-based compound represented by the above chemical formula 1 contains one or more fluorine-based compounds selected from the group consisting of fluorine-based compounds represented by the following chemical formulas 1-1 to 1-9. The fluorine-based compound according to Claim 1: [Chemical formula 1-1] [Chemical Formula 2] In the above chemical formula 1-1, Z ａ１ and Z ｂ１ is independently, -O-, -S- or -NH- R ａ１ and R ｂ１ are each independently CF ３ or CHF ２ and R ｃ１ and R ｃ２ each independently represents an alkylene group having 1 to 6 carbon atoms, Y ａ１ and Y ａ２ each independently represents -CH ２ -, -O-, -S- or -NH- R ｄ１ and R ｄ２ are each independently an alkylene group having 1 to 4 carbon atoms, R ｅ１ and R ｅ２ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p1 and p2 are each independently an integer from 0 to 9, and q1 and q2 are each independently an integer from 0 to 3. [Chemical formula 1-2] 【Chemical Formula 3】 In the above chemical formula 1-2, Z ａ２ and Z ｂ２ are each independently —O—, —S— or —NH—, R ａ２ is CF ３ or CHF ２ and R ｃ３ ~R ｃ５ each independently represents an alkylene group having 1 to 6 carbon atoms, Y ａ３ ~Y ａ５ is, independently of each other, -CH ２ -, -O-, -S- or -NH- and R ｄ３ ~R ｄ５ each independently represents an alkylene group having 1 to 4 carbon atoms, R ｅ３ to R ｅ５ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p3 is an integer from 0 to 9, and q3 to q5 are each independently an integer from 0 to 3. [Chemical formula 1-3] 【Chemical 4】 In the above chemical formula 1-3, Z ａ３ and Z ｂ３ are each independently -O-, -S- or -NH- R ａ３ , R ｂ２ and R ｂ３ are each independently CF ３ or CHF ２ and R ｃ６ is an alkylene group having 1 to 6 carbon atoms, Y ａ６ is -CH ２ -, -O-, -S- or -NH-, and R ｄ６ is an alkylene group having 1 to 4 carbon atoms, R ｅ６ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, R ｆ１ and R ｆ２ are each independently hydrogen or fluorine, p4 to p6 are each independently an integer from 0 to 9, and q6 is an integer from 0 to 3. [Chemical formula 1-4] 【Chemical Formula 5】 In the above chemical formula 1-4, Z ａ４ and Z ｂ４ are each independently —O—, —S— or —NH—, R ａ４ , R ａ５ , R ｂ４ and R ｂ５ are each independently CF ３ or CHF ２ and R ｆ３ ~R ｆ６ are each independently hydrogen or fluorine, p7 to p10 are each independently an integer from 0 to 9. [Chemical formula 1-5] [Chemical Formula 6] In the above chemical formula 1-5, Z ａ５ and Z ｂ５ is, independently of one another, -O-, -S- or -NH-, R ａ６ and R ａ７ are each independently CF ３ or CHF ２ and R ｃ７ and R ｃ８ each independently represents an alkylene group having 1 to 6 carbon atoms, Y ａ７ and Y ａ８ are each independently, -CH ２ -, -O-, -S- or -NH-, and R ｄ７ and R ｄ８ each independently represents an alkylene group having 1 to 4 carbon atoms, R ｅ７ and R ｅ８ are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p11 to p12 are each independently an integer from 0 to 9, and q7 and q8 are each independently an integer from 0 to 3. [Chemical formula 1-6] 【Chemical Formula 7】 In the above chemical formula 1-6, Z ａ６ and Z ｂ６ is each independently —O—, —S— or —NH—, R ａ８ to R ａ１０ are each independently CF ３ or CHF ２ and R ｃ９ is an alkylene group having 1 to 6 carbon atoms, Y ａ９ is -CH ２ -, -O-, -S- or -NH-, and R ｄ９ is an alkylene group having 1 to 4 carbon atoms, R ｅ９ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group, p13 to p15 are each independently an integer from 0 to 9, and q9 is an integer from 0 to 3. [Chemical formula 1-7] [Chemical 8] In the above chemical formula 1-7, Z ａ７ and Z ｂ７ are each independently -O-, -S- or -NH- R ｂ９ 、 R ｃ１０ and R ｄ１０ are each independently a decafluorocyclohexyl group, a phenyl group, a pyridinyl group, a pyrimidinyl group or a methoxyethyl group, [Chemical formula 1-8] 【Chemical Formula 9】 In the above chemical formula 1-8, Z ａ８ and Z ｂ８ each independently represents -O-, -S- or -NH- R ｂ１０ 、 R ｃ１１ and R ｄ１１ are each independently a 2,2,3,3,4,4,5,5 - octafluoro - 1 - pentyl group, a decafluorocyclohexyl group, a phenyl group or a methoxyethyl group, [Chemical formula 1-9] 【Chemical 10】 In the above chemical formula 1-9, Z ａ９ and Z ｂ９ are each independently —O—, —S— or —NH—, R ａ１１ and R ｂ１１ are each independently CF ３ or CHF ２ and R ｃ１２ and R ｄ１２ are each independently a phenyl group or a benzyl group, p16 and p17 are each independently an integer from 0 to 9.

7. The fluorine-based compound according to any one of Claims 1 to 6; A polymer matrix or a precursor thereof; A photopolymerizable composition containing a photoreactive monomer; and a photoinitiator system.

8. A hologram recording medium including a photopolymer layer formed from the photopolymerizable composition according to Claim 7.

9. A method for manufacturing a hologram recording medium, including the steps of applying the photopolymerizable composition according to Claim 7 to form a photopolymer layer; and irradiating a predetermined region of the photopolymer layer with an interferable laser to selectively polymerize the photoreactive monomer contained in the photopolymer layer to record optical information.

10. An optical element including the hologram recording medium according to Claim 8.

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