Fluorine-based compounds, photopolymerizable compositions, holographic recording media, methods for producing the same, and optical elements containing the same

Abstract

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

Description

[Technical Field] 【0001】 [Cross-reference of related applications] This application claims priority under Korean Patent Application No. 10-2022-0146092 dated November 4, 2022, and all content disclosed in the said Korean Patent Application is incorporated herein as part of this specification. 【0002】 This application relates to a fluorine-based compound, a photopolymerizable composition, a holographic recording medium, a method for producing the same, and an optical element containing the same. [Background technology] 【0003】 A hologram recording medium records information by changing the refractive index within the holographic recording layer during the exposure process, and then reproduces the information by reading the difference in refractive index recorded in this way. 【0004】 In this regard, photopolymer compositions can be used in the manufacture of holograms. Photopolymers can easily store optical interference patterns as holograms by photopolymerization of photoreactive monomers. Therefore, photopolymers can be used in a variety of fields, such as smart devices like mobile devices, components of wearable displays, automotive accessories (e.g., head-up displays), holographic fingerprint recognition systems, holographic optical elements having the functions of optical lenses, mirrors, deflectors, filters, diffusion screens, diffraction members, light guides, waveguides, projection screens and / or masks, media and light diffusion plates in optical memory systems, optical wavelength dividers, and reflective and transmissive color filters. 【0005】 Specifically, the photopolymer composition for hologram production comprises a polymer matrix, photoreactive monomers, and a photoinitiator system. A photopolymer layer produced from such a composition is then irradiated with laser interference light to induce localized photopolymerization of the monomers. 【0006】 Such localized photopolymerization processes lead to refractive index modulation, which in turn generates a diffraction grating. The refractive index modulation value (△n) is influenced by the thickness of the photopolymer layer and the diffraction efficiency (DE), and the angular selectivity widens as the thickness decreases. 【0007】 Recently, there has been a growing demand for materials that offer high diffraction efficiency and can stably maintain holograms. As a result, various attempts are being made to manufacture holographic recording media that are thin yet possess high diffraction efficiency and refractive index modulation values. 【0008】 As part of these efforts, a variety of plasticizers that can be added to photopolymer compositions have been developed. Non-reactive plasticizers with low refractive indices can improve the moldability of photopolymer compositions while migrating in other directions from photoreactive monomers with high refractive indices, contributing to even greater refractive index modulation. 【0009】 However, the more various components such as plasticizers are added to the photopolymer composition, the worse their compatibility becomes, leading to a decrease in the basic physical properties of the holographic recording medium and problems such as clouding of the holographic recording medium. In addition, the durability of the holographic recording medium against heat and humidity decreases, and when applied to mobile devices or vehicle accessories (e.g., head-up displays) where the holographic recording medium may be exposed to high temperature and high humidity environments, deformation of the diffraction grating occurs, resulting in image distortion and problems where the intended function cannot be performed. 【0010】 Therefore, there is currently a need to develop new materials that have excellent compatibility with the components of holographic recording media, do not reduce their durability against heat and moisture, and can simultaneously improve optical recording characteristics. [Overview of the project] [Problems that the invention aims to solve] 【0011】 According to one 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 yet another embodiment of the present invention, a holographic recording medium formed from the photopolymerizable composition and a method for producing the same are provided. 【0014】 According to yet another embodiment of the present invention, an optical element including the holographic recording medium is provided. [Means for solving the problem] 【0015】 The following describes specific embodiments of the invention, including fluorine-based compounds, photopolymerizable compositions, holographic recording media, methods for producing the same, and optical elements containing the same. 【0016】 According to one embodiment of the invention, a fluorine-based compound represented by the following chemical formula 1 is provided. [Chemical formula 1] [ka] In the above chemical formula 1, Z 1 is -O- or -NH-, Z 2 These are single bonds, -O- or -NH-, L 1 This is a single bond or a divalent to hexavalent organic group obtained by removing a hydroxyl group from a polyol having 2 to 6 alcohol groups. n and m are independent integers between 1 and 5, and the sum of n and m is between 2 and 6. R 1 This is a methyl group or an ethyl group, R 2 ~R 4 At least one of these is a fluorine-containing substituent, which is a C1-C20 alkyl group substituted with two or more fluorines, a C3-C30 cycloalkyl group substituted with two or more fluorines, or a C6-C30 aryl group substituted with two or more fluorines. R 2 and R 3 When R and R are not fluorine-containing substituents, they are each independently hydrogen, 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 of these -CH2- are substituted with -O-, -S-, or -NH-. R 4 When R is not a fluorine-containing substituent, it is an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 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 of these -CH2- are substituted with -O-, -S-, or -NH-. 【0017】 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, a manufacturing method thereof, and an optical element including the hologram recording medium will be described in detail. 【0018】 In the fluorine-based compound of the above embodiment, since fluorine is distributed at the ends of the compound, it has excellent properties such as fluidity, diffusibility, antifouling properties, etc., due to the effects of fluorine. Accordingly, the fluorine-based compound can be used for various applications such as a plasticizer, a surfactant, or an antifouling agent in various fields. Among them, when the fluorine-based compound of the above embodiment is applied as a plasticizer to a hologram recording medium, it can contribute to increasing the refractive index modulation due to its low refractive index and non-reactive properties. 【0019】 In particular, the inventors of the present invention have completed the present invention by confirming through experiments that the fluorine-based compound represented by chemical formula 1 has excellent compatibility with other components forming the holographic recording medium, excellent stability against heat and moisture, and exhibits transparent optical properties while improving optical recording characteristics, thereby providing a holographic recording medium that exhibits high reliability even in high temperature / high humidity environments. 【0020】 In the above chemical formula 1, L 1 This consists of a part containing a carbonyl group (moiety) and R 4 The part containing is joined together. Therefore, the sum of n and m is 2 to 6, L 1 This is the same as the number of connections. 【0021】 As an example, in the above chemical formula 1, L 1 L may be a single bond. In the above chemical formula 1, 1 If it is a single bond, then n and m are each 1, and Z 2 It may also be a single bond. In this case, the fluorine-based compound represented by chemical formula 1 may also be represented by the following chemical formula 1-1. [Chemical formula 1-1] [ka] In the above chemical formula 1-1, Z 1' , R 1' , R 2' , R 3' and R 4' These are the Z of the aforementioned chemical formula 1, respectively. 1 , R 1 , R 2 , R 3 and R 4 It is identical to the above Z 1' , R 1' , R 2' , R 3' and R 4' In this specification, Z of chemical formula 1 1 , R 1 , R 2 , R 3 and R 4 The substituents described as specific examples may also be substituents. 【0022】 As another example, in the above chemical formula 1, L 1 The hydroxyl group of the polyol having 2 to 6 alcohol groups is Z 1 and Z 2 The polyol may be a divalent to hexavalent organic group obtained by substitution, which removes the hydroxyl group. For example, glycerol having three alcohol groups. [ka] A trivalent organic group from which a hydroxyl group has been removed is [ka] It is expressed as follows. 【0023】 In the above chemical formula 1, the L 1 This may be, for example, a divalent organic group obtained by removing a hydroxyl group from a diol such as ethanediol, propanediol, or butanediol; a trivalent organic group obtained by removing a hydroxyl group from a triol such as glycerol or trimethylolpropane; a tetravalent organic group obtained by removing a hydroxyl group from a tetraol such as pentaerythritol or ditrimethylolpropane; a pentavalent organic group obtained by removing a hydroxyl group from a pentaol such as 6-methylheptanepentaol; or a hexavalent organic group obtained by removing a hydroxyl group from a hexaol such as dipentaerythritol. 【0024】 In the above chemical formula 1, L 1 If it is a single bond or a divalent organic group, then n and m are each 1. 1 If the organic group has a 3- to 6-valent valency, then n may be greater than m. For example, n may be an integer between 1 and 3, and m may be an integer of 1. 【0025】 As an example, L 1m may be a trivalent organic group obtained by removing a hydroxyl group from glycerol, which is a triol. Then, n may be 2 and m may be 1. In this case, the fluorine-based compound represented by chemical formula 1 may also be represented by the following chemical formulas 1-2. [Chemical formula 1-2] [ka] In the above chemical formulas 1 and 2, Z 1" , Z 2" , R 1" , R 2" , R 3" and R 4" These are the Z of the aforementioned chemical formula 1, respectively. 1 , Z 2 , R 1 , R 2 , R 3 and R 4 It is identical to the above Z 1" , Z 2" , R 1" , R 2" , R 3" and R 4" In this specification, Z of chemical formula 1 1 , Z 2 , R 1 , R 2 , R 3 and R 4 The substituents described as specific examples may also be substituents. 【0026】 In the above chemical formula 1, R 2 ~R 4 At least one of the is a fluorine-containing substituent. The fluorine-containing substituent may be a C1-C20 alkyl group substituted with two or more fluorines, a C3-C30 cycloalkyl group substituted with two or more fluorines, or a C6-C30 aryl group substituted with two or more fluorines. Specifically, the fluorine-containing substituent may be a C1-C20 linear alkyl group substituted with two or more fluorines. More specifically, the fluorine-containing substituent may be -(CH2) a (CF2) b CHF2 or -(CH2) a (CF2)b It may be CF3. Here, a is an integer from 0 to 3, an integer from 0 to 2, or an integer of 1, and b may be an integer from 0 to 19, an integer from 0 to 15, an integer from 0 to 12, an integer from 0 to 11, an integer from 0 to 10, or an integer from 0 to 9. 【0027】 In the chemical formula 1, R 2 and R 3 When they are not fluorine-containing substituents, R 2 and R 3 are each independently hydrogen, 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 of these -CH2- are substituted with -O-, -S-, or -NH-. 【0028】 Specifically, in the chemical formula 1, when R 2 and R 3 are not fluorine-containing substituents, R 2 and R 3 are each independently hydrogen, 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, or -(R 5 -O) p -R 6 which may also be. In the said -(R 5 -O) p -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, and p may be an integer from 1 to 12. 【0029】 More specifically, in the chemical formula 1, when R 2 and R 3 are not fluorine-containing substituents, R 2 and R 3is, independently of each other, hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, a tetrahydropyranyl group, a phenyl group or -(R 5 -O) p -R 6 and may be. Here, the R 5 may be an ethylene group, an n-propylene group or an n-butylene group, and among them, may be an ethylene group. The R 6 may be a methyl group, an ethyl group, an n-propyl group or an n-butyl group, and among them, may be a methyl group. The p may be, for example, an integer of 1 to 12, an integer of 1 to 10, an integer of 1 to 8, an integer of 1 to 6, an integer of 1 to 5, an integer of 1 to 4, or an integer of 1 to 3. 【0030】 In the chemical formula 1, when R 4 is not a fluorine-containing substituent, R 4 is an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 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-. 【0031】 Specifically, in the chemical formula 1, when R 4 is not a fluorine-containing substituent, R 4 is a linear alkyl group having 2 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms or -(R 5 -O) p -R 6 and may be. In the -(R 5 -O) p -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, and p may be an integer of 1 to 12. 【0032】 More specifically, in the chemical formula 1, R 4If R is not a fluorine-containing substituent, 4 is, -(R 5 -O) p -R 6 This may also be the case. Here, the R 5 The R may be an ethylene group, an n-propylene group, or an n-butylene group, and in particular may be an ethylene group. 6 p may be a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, and in particular may be a methyl group. For example, p may be an integer from 1 to 12, an integer from 1 to 10, an integer from 1 to 8, an integer from 1 to 6, an integer from 1 to 5, an integer from 1 to 4, or an integer from 1 to 3. 【0033】 The fluorine-based compound represented by chemical formula 1 may include the fluorine-based compound represented by chemical formula 1-1, the fluorine-based compound represented by chemical formula 1-2, or a mixture thereof. Specifically, the fluorine-based compound represented by chemical formula 1 may include one or more fluorine-based compounds selected from the group consisting of fluorine-based compounds represented by the following chemical formulas 1-1-1 to 1-1-5 and 1-2-1 to 1-2-5. [Chemical formula 1-1-1] [ka] In the aforementioned chemical formula 1-1-1, R a1 This is a methyl group or an ethyl group, R b1 and R b2 Each of these is independently hydrogen or an alkyl group having 1 to 4 carbon atoms. R c1 It is CF3 or CHF2, Z a1 is -O- or -NH-, p1 and p2 are independent integers between 0 and 3, and q1 is an integer between 0 and 9. [Chemical formula 1-1-2] [ka] In the aforementioned chemical formula 1-1-2, R a2 This is a methyl group or an ethyl group, R b3 and R b4 These are, independently, a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R c2 It is CF3 or CHF2, Z a2 is -O- or -NH-, q2 is an integer between 0 and 9. [Chemical formula 1-1-3] [ka] In the aforementioned chemical formula 1-1-3, R a3 This is a methyl group or an ethyl group, R b5 and R b6 These are, independently, CF3 or CHF2, R c3 These are alkyl groups having 1 to 4 carbon atoms. Z a3 is -O- or -NH-, p3 and p4 are independent integers between 0 and 9, and q3 is an integer between 0 and 3. [Chemical formula 1-1-4] [ka] In the aforementioned chemical formula 1-1-4, R a4 This is a methyl group or an ethyl group, R b7 It is CF3 or CHF2, R c4 and R c5 Each of these is independently an alkyl group having 1 to 4 carbon atoms. Z a4 is -O- or -NH-, p5 is an integer between 0 and 9, and q4 and q5 are independently integers between 0 and 3. [Chemical formula 1-1-5] [ka] In the aforementioned chemical formula 1-1-5, R a5 This is a methyl group or an ethyl group, R b8 It is CF3 or CHF2, R b9 This is a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R c6 These are alkyl groups having 1 to 4 carbon atoms. Z a5 is -O- or -NH-, p6 is an integer between 0 and 9, and q6 is an integer between 0 and 3. [Chemical formula 1-2-1] [ka] In the aforementioned chemical formula 1-2-1, R a6 This is a methyl group or an ethyl group, R b10 and R b11 Each of these is independently hydrogen or an alkyl group having 1 to 4 carbon atoms. R c7 and R c8 These are, independently, CF3 or CHF2, Z a6 is -O- or -NH-, p7 and p8 are independent integers between 0 and 3, and q7 and q8 are independent integers between 0 and 9. [Chemical formula 1-2-2] [ka] In the aforementioned chemical formula 1-2-2, R a7 This is a methyl group or an ethyl group, R b12 and R b13 These are, independently, CF3 or CHF2, R c9 and Rc10 Each of these is independently an alkyl group having 1 to 4 carbon atoms. Z a7 is -O- or -NH-, p9 and p10 are independent integers between 0 and 9, and q9 and q10 are independent integers between 0 and 3. [Chemical formula 1-2-3] [ka] In the aforementioned chemical formula 1-2-3, R a8 This is a methyl group or an ethyl group, R b14 and R b15 These are, independently, a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R c11 and R c12 These are, independently, CF3 or CHF2, Z a8 is -O- or -NH-, q11 and q12 are each independent integers between 0 and 9. [Chemical formula 1-2-4] [ka] In the aforementioned chemical formula 1-2-4, R a9 This is a methyl group or an ethyl group, R b16 It is CF3 or CHF2, R b17 This is a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R c13 and R c14 Each of these is independently an alkyl group having 1 to 4 carbon atoms. Z a9 is -O- or -NH-, p11 is an integer between 0 and 9, and q13 and q14 are, independently, integers between 0 and 3. [Chemical formula 1-2-5] [ka] In the aforementioned chemical formula 1-2-5, R a10 This is a methyl group or an ethyl group, R b18 It is CF3 or CHF2, R c15 ~R c17 Each of these is independently an alkyl group having 1 to 4 carbon atoms. Z a10 is -O- or -NH-, p12 is an integer between 0 and 9, and q15 to q17 are each independent integers between 0 and 3. 【0034】 On the other hand, according to another embodiment of the invention, a photopolymerizable composition is provided comprising the fluorine-based compound; a polymer matrix or its precursor; a photoreactive monomer; and a photoinitiator system. 【0035】 The aforementioned fluorine-based compound is the fluorine-based compound represented by chemical formula 1 described above, and a detailed explanation is omitted here. 【0036】 The aforementioned photopolymerizable composition can be used in a variety of technological fields. For example, the photopolymerizable composition can be used as a photopolymer composition for forming holographic recording media. 【0037】 The following describes in detail examples of how the aforementioned photopolymerizable composition can be used as a photopolymer composition for forming a holographic recording medium. 【0038】 The aforementioned photopolymer composition includes a polymer matrix or its precursor that serves as a support for the photopolymer layer formed therefrom. 【0039】 The polymer matrix is ​​formed by crosslinking a siloxane polymer containing silane functional groups (Si-H) and a (meth)acrylic polyol. Specifically, the polymer matrix is ​​formed by crosslinking a (meth)acrylic polyol with a siloxane polymer containing silane functional groups. More specifically, the hydroxyl groups of the (meth)acrylic polyol can form crosslinks with the silane functional groups of the siloxane polymer through a hydrosilylation reaction. This hydrosilylation reaction proceeds rapidly under a Pt-based catalyst, even at room temperature (for example, at a temperature in the range of approximately 15 to 30°C without heating or deheating). Therefore, by employing a polymer matrix that can be rapidly crosslinked even at room temperature as a support, the photopolymer composition can improve the manufacturing efficiency and productivity of holographic recording media. 【0040】 The polymer matrix, with its flexible main chain of siloxane polymer, can enhance the mobility of components contained in the photopolymer layer (e.g., photoreactive monomers or plasticizers). Furthermore, the siloxane bonds, which have excellent heat and moisture resistance, facilitate the assurance of reliability of the photopolymer layer on which optical information is recorded and the hologram recording medium containing it. 【0041】 The polymer matrix may 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. 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, "refractive index" may be a value measured with an Abbe refractometer at 25°C. 【0042】 The photopolymer composition may include or include a precursor of the crosslinked polymer matrix described above. If the photopolymer composition includes a precursor of the polymer matrix, it may include a siloxane polymer, a (meth)acrylic polyol, and a Pt catalyst. 【0043】 The siloxane polymer may, as an example, include a repeating unit represented by the following chemical formula 2 and a terminal group represented by the following chemical formula 3. [Chemical formula 2] [ka] In the aforementioned chemical formula 2, Multiple R 11 and R 12 These are either identical or different from each other, and each is independently hydrogen, a halogen, or an alkyl group having 1 to 10 carbon atoms. k is an integer between 1 and 10,000. [Chemical formula 3] [ka] In the aforementioned chemical formula 3, Multiple R 13 ~R 15 These are either identical or different from each other, and each is independently hydrogen, a halogen, or an alkyl group having 1 to 10 carbon atoms. At least one repeating unit of the repeating unit represented by chemical formula 2, and R of one of the terminal groups of the terminal group represented by chemical formula 3 11 ~R 15 At least one of them is hydrogen. In the aforementioned chemical formula 3, -(O)- means that when the Si of the terminal group represented by the chemical formula 3 is bonded to the repeating unit represented by the chemical formula 2, it is bonded either via oxygen (O) or directly without oxygen (O). 【0044】 In this specification, “alkyl group” may be a linear, branched, or cyclic alkyl group. Non-restrictive examples include, in this specification, “alkyl group” may be 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-dimethylpropyl, 1-ethylpropyl, 1-methylbutyl, cyclopentyl, etc.), and hexyl (e.g., n-hexyl, 1-methylpentyl, 2-methyl It may also be pentyl, 4-methylpentyl, 3,3-dimethylbutyl, 1-ethylbutyl, 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.), etc. 【0045】 As an example, R in chemical formulas 2 and 3 11 ~R 15 is methyl or hydrogen, and multiple R 11 ~R 15 At least two of them may be hydrogen. More specifically, the siloxane polymer may be R of chemical formula 2. 11 and R 12 These are methyl and hydrogen, respectively, and R of the chemical formula 3. 13 ~R 15 Compounds in which each is independently methyl or hydrogen (for example, polymethylhydrosiloxanes whose terminal group is a trimethylsilyl group or a dimethylhydrosilyl group); R of part of the above chemical formula 2 11 and R 12 These are methyl and hydrogen, respectively, and the remaining R 11 and R 12 All are methyl, and R of the above chemical formula 3 13 ~R 15Compounds in which each is independently methyl or hydrogen (for example, poly(dimethylsiloxane-co-methylhydrosiloxane) whose terminal group is a trimethylsilyl group or a dimethylhydrosilyl group; or R of the above chemical formula 2) 11 and R 12 All are methyl, and R of the above chemical formula 3 13 ~R 15 The compound may be one in which at least one of the terminal groups is hydrogen, and the rest are independently methyl or hydrogen (for example, a polydimethylsiloxane in which one or all of the terminal groups are dimethylhydrosilyl groups). 【0046】 The siloxane compound may, for example, have a number-average molecular weight (Mn) in the range of 200 to 4,000. 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 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, it prevents problems such as the siloxane polymer volatilizing during the crosslinking process with the (meth)acrylic polyol carried out at room temperature or above, resulting in a low degree of matrix crosslinking, or the siloxane polymer having poor compatibility with other components of the photopolymer composition, leading to phase separation with such components. This enables the holographic recording medium formed from the photopolymer composition to exhibit excellent optical recording characteristics and excellent durability under high temperature / high humidity conditions. 【0047】 The aforementioned number-average molecular weight refers to the number-average molecular weight (unit: g / mol) on a polystyrene basis, measured by the GPC method. In the process of measuring the polystyrene-based number-average molecular weight measured by the GPC method, commonly known analytical instruments, detectors such as differential index detectors, and analytical columns can be used, and commonly applied temperature conditions, solvents, and flow rates can be applied. Specific examples of the measurement conditions include a temperature of 25°C, tetrahydrofuran solvent, and a flow rate of 1 mL / min. 【0048】 The (meth)acrylic polyol can mean a polymer in which one or more, specifically two or more hydroxyl groups are bonded to the main chain or side chain of a (meth)acrylate polymer. In this specification, unless otherwise specified, "(meth)acrylic(system)" refers to acrylic(system) and / or methacrylic(system), and is a term that encompasses all acrylic(system), methacrylic(system), or mixtures of acrylic(system) and methacrylic(system). 【0049】 The (meth)acrylic polyol may be a homopolymer of (meth)acrylate monomers having hydroxyl groups, a copolymer of (meth)acrylate monomers having two or more hydroxyl groups, or a copolymer of (meth)acrylate monomers having hydroxyl groups and (meth)acrylate monomers not having hydroxyl groups. In this specification, unless otherwise specified, "polymer" is a term that encompasses random copolymers, block copolymers, and graft copolymers. 【0050】 Examples of the (meth)acrylate monomer having a hydroxyl group include hydroxyalkyl (meth)acrylate or hydroxyaryl (meth)acrylate, where 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 not having a hydroxyl group include alkyl (meth)acrylate monomer or aryl (meth)acrylate monomer, where the alkyl is an alkyl having 1 to 30 carbon atoms, and the aryl may be an aryl having 6 to 30 carbon atoms. 【0051】 The (meth)acrylic polyol may, for example, have a weight-average molecular weight (Mw) in the range of 150,000 to 1,000,000. The weight-average molecular weight refers to the weight-average molecular weight in polystyrene terms 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 less, or 450,000 or less. When the weight-average molecular weight of the (meth)acrylic polyol satisfies the above range, the polymer matrix fully performs its function as a support, resulting in minimal decrease in recording characteristics for optical information even after extended use. This imparts sufficient flexibility to the polymer matrix, improving the mobility of components contained in the photopolymer composition (e.g., photoreactive monomers or plasticizers), thereby minimizing the decrease in recording characteristics for optical information. 【0052】 In order to adjust the crosslinking density of the (meth)acrylic polyol by the siloxane polymer to a level advantageous for ensuring the functionality of the holographic recording medium, the hydroxyl group equivalent of the (meth)acrylic polyol can be adjusted to an appropriate level. 【0053】 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 may be 600 g / equivalent or more, 700 g / equivalent or more, 800 g / equivalent or more, 900 g / equivalent or more, 1000 g / equivalent or more, 1100 g / equivalent or more, 1200 g / equivalent or more, 1300 g / equivalent or more, 1400 g / equivalent or more, 1500 g / equivalent or more, 1600 g / equivalent or more, 1700 g / equivalent or more, or 1750 g / equivalent or more. Furthermore, the upper limit of the hydroxyl group (-OH) equivalent of the (meth)acrylic polyol may be 2900 g / equivalent or less, 2800 g / equivalent or less, 2700 g / equivalent or less, 2600 g / equivalent or less, 2500 g / equivalent or less, 2400 g / equivalent or less, 2300 g / equivalent or less, 2200 g / equivalent or less, 2100 g / equivalent or less, 2000 g / equivalent or less, or 1900 g / equivalent or less. The hydroxyl group (-OH) equivalent of the (meth)acrylic polyol is the equivalent amount (g / equivalent) per hydroxyl functional group, and is the value obtained by dividing the weight-average molecular weight of the (meth)acrylic polyol by the number of hydroxyl 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 fully performs its role as a support, improving the fluidity of the components contained in the layer formed from the photopolymer composition, and without the problem of the diffraction grating interface collapsing after recording, the initial refractive index modulation value can be maintained at an excellent level even after time has passed, minimizing the decrease in recording characteristics for optical information. 【0054】 The (meth)acrylic polyol may have a glass transition temperature (Tg) in the range of -60 to -10°C, for example. Specifically, the lower limit of the glass transition temperature may 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 may 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, thereby increasing the mobility (fluidity) of other components in the photopolymer composition and improving the moldability of the photopolymer composition. The glass transition temperature can be measured using known methods, such as DSC (Differential Scanning Calorimetry) or DMA (dynamic mechanical analysis). 【0055】 The refractive index of the (meth)acrylic polyol may be, for example, 1.40 or more and less than 1.50. Specifically, the lower limit of the refractive index of the (meth)acrylic polyol may be, for example, 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, and the upper limit may be, for example, 1.49 or less, 1.48 or less, 1.47 or less, 1.46 or less, or 1.45 or less. When the (meth)acrylic polyol has a refractive index within the range described above, 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 (value measured using an Abbe refractometer at 25°C) and the fraction (molar ratio) of each monomer. 【0056】 The (meth)acrylic polyol and 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 hydroxyl group (-OH) of the (meth)acrylic polyol is 0.80 to 3.5. In other words, when forming the polymer matrix, the type and content of the siloxane polymer and (meth)acrylic polyol can be selected to satisfy the above 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 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 above range of molar ratio (SiH / OH) is satisfied, the polymer matrix is ​​crosslinked with an appropriate crosslinking density, improving reliability under high temperature / high humidity conditions and enabling the achievement of a sufficient refractive index modulation value. 【0057】 The Pt-based catalyst may, for example, be Karstedt's catalyst. The polymer matrix precursor may, if necessary, additionally include non-metallic catalysts such as rhodium-based, iridium-based, rhenium-based, molybdenum-based, iron-based, nickel-based, alkali metal or alkaline earth metal-based, Lewis acid-based, or carbene-based catalysts, in addition to the Pt-based catalyst. 【0058】 On the other hand, a holographic recording medium can be manufactured by irradiating a photopolymer layer formed from the photopolymer composition with object light and reference light. Depending on the interference length of the object light and reference light, photopolymerization of photoreactive monomers does not occur in the canceling interference region, while photopolymerization of photoreactive monomers occurs in the reinforcement interference region. As the photoreactive monomers are continuously consumed in the reinforcement interference region, a concentration difference between the photoreactive monomers in the canceling interference region and the reinforcement interference region is created, and as a result, the photoreactive monomers in the canceling interference region diffuse into the reinforcement interference region. A diffraction grating is generated by the refractive index modulation that occurs in this way. 【0059】 Therefore, the photoreactive monomers may include compounds having a higher refractive index than the polymer matrix in order to achieve the refractive index modulation described above. However, it is not limited to all photoreactive monomers in the photopolymer composition having a higher refractive index than the polymer matrix; at least some photoreactive monomers may have a higher refractive index than the polymer matrix in order to achieve a high refractive index modulation value. For example, the photoreactive monomers may include monomers with refractive indices of 1.50 or higher, 1.51 or higher, 1.52 or higher, 1.53 or higher, 1.54 or higher, 1.55 or higher, 1.56 or higher, 1.57 or higher, 1.58 or higher, 1.59 or higher, or 1.60 or higher and 1.70 or lower. 【0060】 The photoreactive monomer may 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. In this case, 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. 【0061】 The monofunctional monomer may include, for example, one or more selected from the group consisting of benzyl (meth)acrylate (Miwon M1182 refractive index 1.5140), benzyl 2-phenyl acrylate, phenoxybenzyl (meth)acrylate (Miwon M1122 refractive index 1.565), phenol (ethylene oxide) (meth)acrylate (phenol(EO)(meth)acrylate; Miwon M140 refractive index 1.516), phenol (ethylene oxide) 2 (meth)acrylate (phenol(EO)2(meth)acrylate; Miwon M142 refractive index 1.510), O-phenylphenol (ethylene oxide) (meth)acrylate (O-phenylphenol(EO)(meth)acrylate; Miwon M1142 refractive index 1.577), phenylthioethyl (meth)acrylate (Miwon M1162 refractive index 1.560), and biphenylmethyl (meth)acrylate. 【0062】 The aforementioned polyfunctional monomer is, for example, bisphenol A (ethylene oxide) 2~10 Di(meth)acrylate (bisphenol A(EO) 2~10(meth)acrylate; Miwon's M240 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 (Miwon's PE210 refractive index 1.557, PE2120A refractive index 1.533, PE2120B refractive index 1.534, PE2020C refractive index 1.539, PE2120S refractive index 1.556), Bisful Orange (meth)acrylate (Miwon's HR6022 refractive index 1.600, HR6040 refractive index 1.600, HR604 It may contain one or more substances selected from the group consisting of (2 refractive index 1.600), modified bisphenol full orange (meth)acrylate (Miwon's HR6060 refractive index 1.584, HR6100 refractive index 1.562, HR6200 refractive index 1.530), tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate (Miwon's M370 refractive index 1.508), phenol novolac epoxy (meth)acrylate (Miwon's SC6300 refractive index 1.525), and cresol novolac epoxy (meth)acrylate (Miwon's SC6400 refractive index 1.522, SC6400C refractive index 1.522). 【0063】 The photopolymer composition may contain 50 to 300 parts by weight of a photoreactive monomer per 100 parts by weight of the polymer matrix. For example, the lower limit of the photoreactive monomer content 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 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. Satisfying the above range is advantageous in ensuring excellent optical recording characteristics and durability in high temperature / high humidity environments. 【0064】 In this specification, the polymer matrix content refers to the combined content (by weight) of the (meth)acrylic polyol and siloxane polymer that form the matrix. In other words, the polymer matrix content refers to the total content including the polymer matrix formed by the cross-linking of the (meth)acrylic polyol and siloxane polymer, and the polymer matrix precursor that is not partially cross-linked. 【0065】 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. 【0066】 The aforementioned photopolymer composition may include a photosensitizer and a co-initiator as a photoinitiator system. 【0067】 For example, a photosensitive dye can be used as the photosensitizer. Specifically, the aforementioned photosensitive dyes include, for example, silicon rhodamine compounds, sulfonium derivatives of ceramidenin, 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, and crystal violet. One or more substances selected from the group consisting of violet, Brilliant Green, Astrazon Orange G, Darrow Red, Pyronin Y, Basic Red 29, Pyrylium I (pyrylium iodide), Safranin O, Cyanine, Methylene Blue, Azure A, and BODIPY may be used. 【0068】 As an example, the photosensitive dye can be either Cy3 and Cy5 (H-Nu640, Spectra) as cyanine dyes, or safranin O can be used. 【0069】 The photopolymer composition may contain the photosensitive dye in an amount of 0.01 to 10 parts by weight per 100 parts by weight of the polymer matrix. Specifically, the lower limit of the photosensitive dye content 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 may be, for example, 5 parts by weight or less. When the above range is satisfied, it is advantageous to exhibit an appropriate polymerization reaction rate and ensure the desired optical recording characteristics. 【0070】 The co-initiator may be an electron donor, an electron acceptor, or a mixture thereof. 【0071】 As an example, the photopolymer composition may contain an electron donor as a co-initiator. The electron donor may, for example, include a borate anion represented by the following chemical formula 4. [Chemical formula 4] BX 1 X 2 X 3 X 4 In the aforementioned chemical formula 4, X 1 ~X 4 Each of these is independently a substituted or unsubstituted C1-C20 alkyl group, a C2-C20 alkenyl group, a C6-C30 aryl group, a C7-C30 arylalkyl (arylalkyl) group, a C7-C30 alkylaryl (alkylaryl) group, or an allyl group, and X 1 ~X 4 At least one of them is not an aryl group. 【0072】 When the C1-C20 alkyl group, C2-C20 alkenyl group, C6-C30 aryl group, C7-C30 arylalkyl (arylalkyl) group, C7-C30 alkylaryl (alkylaryl) group, or allyl group is substituted, it may be substituted with one or more selected from the group consisting of halogens and C1-C5 alkoxy groups. 【0073】 Specifically, X 1 ~X 3 Each of these is independently halogen-substituted or unsubstituted methyl, ethyl, propyl, n-butyl, n-pentyl, n-hexyl, cyclobutyl, cyclopentyl, cyclohexyl, ethenyl, propenyl, phenyl, methylphenyl, methoxyphenyl, naphthyl, methylnaphthyl, or methoxynaphthyl, and X 4 This may be n-butyl, n-pentyl, or n-hexyl. More specifically, the borate anion represented by chemical formula 4 may be, for example, a triphenylbutyl borate anion. 【0074】 The cation bonded to the borate anion is one that 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 four substituents, and each of the four substituents may independently be a C1-C40 alkyl group, a C6-C30 aryl group, a C6-C40 arylalkyl group, or a C2-C40 alkyl group linked via an ester bond (for example, -CH2CH2-O-CO-CH2CH2CH3). 【0075】 As the electron donor, for example, commercially available butyryl choline triphenylbutylborate (Borate V, manufacturer: Spectra group) can be used. 【0076】 As an example, the photopolymer composition may contain an electron acceptor as a co-initiator. The electron acceptor may include, for example, an onium salt such as a sulfonium salt, an iodonium salt, or a mixture thereof. 【0077】 As an example, the electron acceptor may include an iodonium salt. For example, commercially available H-Nu254 (Spectra) can be used as the electron acceptor. 【0078】 The photopolymer composition of the above embodiment may contain the co-initiator in an amount of 0.05 to 10 parts by weight per 100 parts by weight of the polymer matrix. Specifically, the lower limit of the co-initiator content may be, for example, 0.1 parts by weight or more, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, or 0.5 parts 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 exhibit an appropriate polymerization reaction rate and ensure the desired optical recording characteristics. 【0079】 The photoinitiator system may include additional photoinitiators to remove the color of the photosensitive dye and to react all unreacted photoreactive monomers after light irradiation for recording. Examples of the photoinitiators include imidazole derivatives, bisimidazole derivatives, N-arylglycine derivatives, organic azide compounds, titanocene, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, amine derivatives, diazonium salts, sulfonium salts, iodonium salts, sulfonic acid esters, imidosulfonates, dialkyl-4-hydroxysulfonium salts, arylsulfonic acid-p-nitrobenzyl esters, silanol-aluminum complexes, (η6-benzene)(η5-cyclopentadienyl)iron(II), benzoin tosylate, 2,5-dinitrobenzyl tosylate, N-tosylphthalimide, or mixtures thereof.More specifically, the photoinitiators include 1,3-di(t-butyldioxycarbonyl)benzophenone, 3,3',4,4''-tetrakis(t-butyldioxycarbonyl)benzophenone, 3-phenyl-5-isoxazolone, and 2-mercapto benzimidazole, bis(2,4,5-triphenyl)imidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one (product name: Irgacure 651 / manufacturer: BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure 184 / manufacturer: BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (product name: Irgacure 369 / manufacturer: BASF), bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium (product name: Irgacure 784 / manufacturer: BASF), Ebecryl P-115 (manufacturer: SK entis), Cyracure UVI-6970, Cyracure Examples include, but are not limited to, UVI-6974, Cyracure UVI-6990 (manufactured by Dow Chemical Co., USA), Irgacure 264, Irgacure 250 (manufactured by BASF), CIT-1682 (manufactured by Nippon Soda), or mixtures thereof. 【0080】 The aforementioned photopolymer composition contains a fluorine-based compound as a plasticizer. The fluorine-based compound is the fluorine-based compound represented by chemical formula 1, and a detailed explanation is omitted here. 【0081】 The aforementioned plasticizer facilitates refractive index modulation during the manufacturing of holographic recording media. More specifically, the plasticizer lowers the glass transition temperature of the polymer matrix, improving the fluidity of photoreactive monomers. It has low refractive index and non-reactive properties, is uniformly distributed within the polymer matrix, and contributes to refractive index modulation by moving in the opposite direction when photoreactive monomers that have not been photopolymerized move. Furthermore, the plasticizer can also contribute to improving the moldability of the photopolymer composition. 【0082】 The fluorine-based compound may have a low refractive index of 1.45 or less in order to perform the function of a plasticizer as described above. 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 lower refractive index than the photoreactive monomer described above, the refractive index of the polymer matrix can be made even lower, and the refractive index modulation with the photoreactive monomer can be made larger. 【0083】 By including the fluorine-based compound represented by chemical formula 1, the aforementioned photopolymer composition can provide a holographic recording medium that not only exhibits excellent optical recording properties but also possesses excellent reliability and high transparency even in high-temperature / high-humidity environments. 【0084】 More specifically, the fluorine-based compound represented by chemical formula 1 exhibits sufficient low refractive index to greatly increase refractive index modulation with photoreactive monomers, and can fully fulfill the role of a basic plasticizer that improves the diffusivity of components in the photopolymer composition. In addition, the fluorine-based compound represented by chemical formula 1 exhibits little migration to the surface of the photopolymer layer, even at high temperatures and high humidity environments, is resistant to heat and moisture, does not decompose well even under high temperature / high humidity conditions, and can improve reliability in high temperature / high humidity environments. Furthermore, the fluorine-based compound represented by chemical formula 1 exhibits excellent compatibility with components having a high refractive index, and ensures highly transparent optical properties through excellent resistance to heat and humidity. 【0085】 The photopolymer composition may contain 20 to 200 parts by weight of the fluorine-based compound per 100 parts by weight of the polymer matrix. Specifically, the lower limit of the fluorine-based compound content 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, it is possible to show a large refractive index modulation value after recording by a fluorine-based compound with a sufficiently low refractive index without problems such as poor compatibility with the components contained in the photopolymer composition causing some of the fluorine-based compound to dissolve onto the surface of the photopolymer layer or poor haze, which is advantageous in ensuring excellent optical recording characteristics. 【0086】 The aforementioned photopolymer composition may further contain additives such as defoaming agents. 【0087】 The photopolymer composition may contain a silicone-based reactive additive as an antifoaming agent. For example, a commercially available silicone-based reactive additive such as Tego Rad2500 can be used. 【0088】 The content of the aforementioned additive, for example, the defoaming agent, can be appropriately adjusted to a level that does not interfere with the function of the holographic recording medium. 【0089】 The aforementioned photopolymer composition may additionally contain a solvent. 【0090】 The solvent may be an organic solvent, or, as an example, 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 ethers selected from the group consisting of tetrahydrofuran or propylene glycol monomethyl ether. 【0091】 The organic solvent may be added at the time when each component of the photopolymer composition is mixed, or it may be added to the photopolymer composition in a state where each component is dispersed or mixed in the organic solvent. 【0092】 The photopolymer composition may contain a solvent such that the solid content concentration is 1 to 90% by weight. Specifically, the photopolymer composition may contain a solvent such that the solid content concentration 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 this range, the photopolymer composition can exhibit appropriate flowability, form a coating film without defects such as stripes, and form a photopolymer layer that exhibits desired physical properties and surface characteristics without defects occurring during the drying and curing process. 【0093】 On the other hand, according to yet another embodiment of the invention, a holographic recording medium is provided which includes a photopolymer layer formed from the photopolymerizable composition. 【0094】 In this specification, unless otherwise specified, “hologram recording medium” means a medium or media capable of recording optical information in the entire visible light range and ultraviolet range (e.g., 300-1,200 nm) through an exposure process. For example, the holograms described herein may include all visual holograms, such as inline (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. 【0095】 The photopolymer layer, formed from the photopolymerizable composition (photopolymer composition), exhibits a large refractive index modulation value and high diffraction efficiency despite its thin thickness, ensuring excellent optical recording characteristics and demonstrating excellent reliability even in high-temperature / high-humidity environments. 【0096】 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. 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. 【0097】 The holographic recording medium may further include a substrate on at least one surface of the photopolymer layer. The type of substrate is not particularly limited, and any known in the relevant art can be used. For example, substrates such as glass, PET (polyethylene terephthalate), TAC (triacetyl cellulose), PC (polycarbonate), and COP (cycloolefin polymer) can be used. 【0098】 The holographic recording medium can have a high diffraction efficiency. For example, when a Notch filter hologram is recorded on the holographic recording medium, it can have a diffraction efficiency of 70% or more. In this case, the thickness of the photopolymer layer may be, for example, 5 to 30 μm. Specifically, when a Notch filter hologram is recorded, the diffraction efficiency may be 71% or more, 72% or more, 73% or more, 74% or more, 75% or more, 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, 85% or more, 86% or more, 87% or more, 88% or more, 89% or more, 90% or more, or 91% or more. In this way, the holographic recording medium can achieve excellent diffraction efficiency even when it includes a thin photopolymer layer. The diffraction efficiency can be measured by the method described in the test examples later. 【0099】 Even if the thickness of the photopolymer layer of the holographic recording medium is as thin as 5 to 30 μm, it is possible to achieve refractive index modulation values ​​(△n) of 0.020 or higher, 0.025 or higher, 0.026 or higher, 0.027 or higher, 0.028 or higher, 0.029 or higher, 0.030 or higher, 0.031 or higher, 0.032 or higher, 0.033 or higher, 0.034 or higher, or 0.035 or higher. The upper limit of the refractive index modulation value is not particularly limited, but for example, it may be 0.060 or lower. The refractive index modulation value can be measured by the method described in the test examples later. 【0100】 The holographic recording medium can exhibit excellent durability in high-temperature / high-humidity environments. For example, the peak variation of the holographic recording medium, calculated by the following formula 3, may be 3% or less. [Formula 3] Peak variation = {|1-A1 / A0|} x 100 In the above equation 3, A0 is the wavelength of the holographic recording medium with the lowest transmittance in the wavelength range of 300 to 1,200 nm, and A1 is the wavelength of the holographic recording medium with the lowest transmittance measured after exposure to a temperature of 60°C and a relative humidity of 90% for 72 hours. 【0101】 The fact that the peak variation calculated by Equation 3 above is 3% or less means that the deformation (shrinkage or expansion) of the diffraction grating can be suppressed so that the peak variation remains 3% or less even when exposed to harsh conditions such as high temperature and high humidity. Such holographic recording media can provide good color reproduction and image clarity even when exposed to harsh conditions. 【0102】 The peak variation for 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. 【0103】 The aforementioned holographic recording medium not only exhibits excellent durability in high-temperature / high-humidity environments after recording, but also in high-temperature / high-humidity environments before recording. 【0104】 As an example, the hologram recording medium of the other embodiment described above may have a refractive index variation of 1.0% or less, calculated by the following formula 4. [Formula 4] Refractive index variation (%) = {|1-n1 / n0|} x 100 In Equation 4, n0 is the refractive index of a sample obtained by bleaching a hologram recording medium with a white LED after storing it at a temperature of 20-25°C and a relative humidity of 40-50% before recording, and n1 is the refractive index of a sample obtained by bleaching a hologram recording medium with a white LED after storing it at a temperature of 60°C and a relative humidity of 90% for 72 hours before recording. 【0105】 The fact that the refractive index variation is 1.0% or less means that the hologram recording medium exhibits excellent stability even when exposed to high temperature and high humidity conditions before recording, and that the difference in refractive index before and after exposure to high temperature and high humidity conditions is small, at 1.0% or less. In particular, since the plasticizer contained in the hologram recording medium before recording is fluid, it may migrate to the surface of the photopolymer layer and not exhibit the optical recording characteristics originally intended. However, the hologram recording medium of the other embodiment contains a fluorine-based compound represented by chemical formula 1 as a plasticizer, so that the refractive index variation calculated by formula 4 is very small. 【0106】 The upper limit of the refractive index variation of the hologram recording medium may be, for example, 1.0% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.25% or less, or 0.2% or less. The lower limit may be, for example, 0% or more. 【0107】 On the other hand, holographic recording media use a mixture of components with low refractive index and components with high refractive index for recording optical properties, and therefore tend to have opaque properties due to the mismatch between these components. However, by using a fluorine-based compound with a specific structure that exhibits excellent mismatch, the holographic recording media can exhibit highly transparent optical properties. 【0108】 For example, the haze of the hologram recording medium may be 2% or less. The upper limit of the haze may be, for example, 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 below. 【0109】 The aforementioned holographic recording medium is expected to provide a variety of optical elements that can be used even in environments where a lot of heat is generated or humidity is high, by exhibiting not only excellent optical recording characteristics and excellent durability in high temperature / high humidity environments, but also highly transparent optical properties. 【0110】 The aforementioned holographic recording medium is not limited to that which may have a reflective hologram or a transmissive hologram recorded on it. 【0111】 As an example, the diffraction grating of the photopolymer layer may be a reflective hologram grating. In the case of a transmissive hologram grating, since the diffraction grating is formed perpendicular to the plane of the substrate, the linear expansion coefficients of the substrate and the photopolymer have a greater influence on the deformation of the grating. In contrast, since a reflective hologram grating is formed horizontally to the plane of the substrate, the expansion or contraction of the volumetric hologram grating formed inside the photopolymer has a greater influence on the sharpness of the image than a mismatch in the linear expansion coefficients of the substrate and the diffraction grating. Therefore, a hologram recording medium having such peak variation characteristics is more suitable for a reflective hologram. 【0112】 As an example, the diffraction grating of the photopolymer layer may be formed in a direction parallel or horizontal to the bottom surface on which the substrate is placed. In this case, "parallel" or "horizontal" means substantially parallel or horizontal, and can mean that the fringe angle of the diffraction grating with respect to the bottom surface on which the substrate is placed is parallel or horizontal within an error range of ±5°, ±4°, ±3°, ±2°, or ±1°. 【0113】 The holographic recording medium may have a notch filter structure in relation to the diffraction grating structure. Having a notch filter structure in the holographic recording medium means, for example, that the diffraction grating is not tilted (non-slanted) (effectively 0°) relative to the substrate surface, such that the diffraction grating is parallel to the substrate surface. Such a holographic recording medium may 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. The two repeating layers may each have the same or different predetermined thicknesses. Recordings of such non-slanted diffraction gratings can be manufactured in a manner that makes the incident angles of the incident object light and the reference light the same with respect to the normal. In a non-slanted structure, the degree of deformation (e.g., shrinkage or expansion) under high temperature / high humidity conditions is more clearly observed than in a slantated structure, and it is less affected by the shrinkage and expansion of the substrate. 【0114】 The applications of the holographic recording medium are not particularly limited. Unrestrictive examples include applications likely to be exposed to high-temperature / high-humidity environments, specifically smart devices such as mobile devices, components for wearable displays, or automotive components (e.g., head-up displays). 【0115】 On the other hand, according to yet another embodiment of the invention, a method for manufacturing a hologram recording medium is provided, comprising the steps of: applying the photopolymerizable composition to form a photopolymer layer; and irradiating a predetermined area of ​​the photopolymer layer with a coherent laser to selectively polymerize the photoreactive monomers contained in the photopolymer layer to record optical information. 【0116】 The aforementioned photopolymerizable composition may be the photopolymer composition of the embodiment described above, and since the photopolymer composition has been explained in detail earlier, a detailed explanation will be omitted here. 【0117】 In the step of forming the photopolymer layer, a photopolymer composition containing the above-described configuration can first be manufactured. When manufacturing the photopolymer composition, any commonly known mixer, stirrer, or similar device can be used for mixing the components without any limitations. Such a mixing process may be carried out at temperatures in the range of 0°C to 100°C, 10°C to 80°C, or 20°C to 60°C. 【0118】 In the step of forming the photopolymer layer, the prepared photopolymer composition can be applied to form a coating film made from the photopolymer composition. The coating film may be dried naturally at room temperature or at a temperature in the range of 30 to 80°C. This process can induce a hydrosilylation reaction between the hydroxyl group of the unreacted (meth)acrylic polyol and the silane functional group of the siloxane polymer. 【0119】 The photopolymer layer produced in the step of forming the aforementioned photopolymer layer may have a fluorine-based compound, a photoreactive monomer and a photoinitiator system, and additives added as needed uniformly dispersed within the crosslinked polymer matrix. 【0120】 Subsequently, when the photopolymer layer is irradiated with a coherent laser during the optical information recording stage, polymerization of photoreactive monomers occurs in regions where reinforcement interference occurs, forming a photopolymer. In regions where cancellation interference occurs, polymerization of photoreactive monomers does not occur or is suppressed, resulting in the presence of photoreactive monomers. The unreacted photoreactive monomers then diffuse towards the photopolymer side where the concentration of photoreactive monomers is lower, causing refractive index modulation, which generates a diffraction grating. As a result, a hologram, or optical information, is recorded on the photopolymer layer having the diffraction grating. 【0121】 The method for manufacturing the hologram recording medium may additionally include a step of photobleaching, in which the photopolymer layer on which the optical information is recorded is irradiated with light to bleach it, after the step of recording the optical information. 【0122】 In the photobleaching step, ultraviolet light is irradiated onto the photopolymer layer on which optical information is recorded to terminate the reaction of photoreactive monomers remaining in the photopolymer layer and remove the color of the photosensitive dye. For example, in the photobleaching step, ultraviolet light (UVA) in the 320-400 nm range is irradiated to terminate the reaction of photoreactive monomers and remove the color of the photosensitive dye. 【0123】 On the other hand, according to yet another embodiment of the invention, an optical element including the holographic recording medium is provided. 【0124】 Specific examples of the optical elements include smart devices such as mobile devices, components for wearable displays, vehicle accessories (e.g., head-up displays), holographic fingerprint recognition systems, optical lenses, mirrors, deflection mirrors, filters, diffusion screens, diffraction members, light guides, waveguides, projection screens and / or masks, media and light diffusion plates for optical memory systems, optical wavelength dividers, reflective and transmissive color filters, and the like. 【0125】 An example of an optical element including the hologram recording medium is a hologram display device. The hologram display device includes a light source, an input unit, an optical system, and a display unit. 【0126】 Specifically, the light source unit is the part that emits a laser beam used to provide, record, and reproduce three-dimensional image information of an object in the input unit and the display unit. 【0127】 The aforementioned input unit is the part that pre-inputs three-dimensional image information of an object to be recorded on the display unit. Specifically, it is the part that can input three-dimensional information of an object, such as the intensity and phase of light in different spaces, to an electrically driven liquid crystal (SLM), and at this time, the input beam can be used. 【0128】 The optical system may consist of mirrors, polarizers, beam splitters, beam shutters, lenses, and the like. The optical system can distribute the laser beam emitted from the light source to an input beam sent to the input unit, a recording beam sent to the display unit, a reference beam, an erase beam, a readout beam, and the like. 【0129】 The display unit receives three-dimensional image information of an object from the input unit, records it on a hologram plate made of an optically addressed SLM (optically driven SLM), and can reproduce the three-dimensional image of the object. At this time, the three-dimensional image information of the object can be recorded by the interference of the input beam and the reference beam. The three-dimensional image information of the object recorded on the hologram plate can be reproduced as a three-dimensional image by the diffraction pattern generated by the readout beam, and the erase beam can be used to quickly remove the formed diffraction pattern. On the other hand, the hologram plate can move between the input position and the playback position of the three-dimensional image. [Effects of the Invention] 【0130】 According to one embodiment of the invention, a fluorine-based compound can be included in a photopolymerizable composition and not only exhibit excellent optical recording properties, but also provide a holographic recording medium and an optical element containing the same that exhibit transparent optical properties and excellent reliability even in high-temperature and high-humidity environments. [Brief explanation of the drawing] 【0131】 [Figure 1] This diagram schematically shows the setup of a recording device for hologram recording. Specifically, Figure 1 schematically shows the process in which a laser of a predetermined wavelength is irradiated from a light source 10, and then irradiated onto a PP (hologram recording medium) 80 located on one side of the mirror 70, after passing through mirrors 20, 20', iris 30, spatial filter 40, iris 30', collimation lens 50, and polarized beam splitter (PBS) 60. [Modes for carrying out the invention] 【0132】 The function and effects of the invention will be explained in more detail below through specific embodiments of the invention. However, these are presented as examples of the invention and do not limit the scope of the invention's rights in any way. 【0133】 In the following manufacturing examples, examples, and comparative examples, the content of raw materials, etc., refers to the content based on solid content unless otherwise specified. 【0134】 Manufacturing Example 1: Production of fluorine-based compounds 100 g of 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 42 g of potassium carbonate, and 14 g of epichlorohydrin were added to a 2 L jacketed reactor and reacted at 70°C for 24 hours. After cooling to room temperature, the reaction product was filtered, and the resulting filtrate was washed with 700 mL of chloroform and 500 mL of water to concentrate the organic layer. 63 g of the first intermediate product was obtained by high-vacuum distillation. 【0135】 In a 2L jacketed reactor, 100g of 2,2-bis(hydroxymethyl)propionic acid, 520g of 2-(2-methoxyethoxy)ethyl chloride, 340g of potassium hydroxide, 1g of DABCO, and 500mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and neutralization was performed by adding 700mL of hydrochloric acid. The organic layer was concentrated. 200g of the second intermediate compound was obtained by high-vacuum distillation. 【0136】 In a 2L jacketed reactor, 100g of the first intermediate product, 62g of the second intermediate product, 2g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 100g of a fluorinated compound represented by the following chemical formula a. [Chemical formula a] [ka] 【0137】 Manufacturing Example 2: Production of fluorine-based compounds 100 g of 2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol, 49 g of potassium carbonate, and 17 g of epichlorohydrin were added to a 2 L jacketed reactor and reacted at 70°C for 24 hours. After cooling to room temperature, the reaction product was filtered, and the resulting filtrate was washed with 700 mL of chloroform and 500 mL of water to concentrate the organic layer. 90 g of the first intermediate product was obtained by high-vacuum distillation. 【0138】 In a 2L jacketed reactor, 100g of 2,2-bis(hydroxymethyl)propionic acid, 352g of 2-methoxyethyl chloride, 340g of potassium hydroxide, 1g of DABCO, and 500mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and the mixture was neutralized with 700mL of hydrochloric acid. The organic layer was concentrated. 150g of the second intermediate compound was obtained by high-vacuum distillation. 【0139】 In a 2L jacketed reactor, 100g of the first intermediate product, 40g of the second intermediate product, 2g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 100g of a fluorinated compound represented by the following chemical formula b. [Chemical formula b] [ka] 【0140】 Manufacturing Example 3: Production of fluorinated compounds 100g of 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1-heptanol, 42g of potassium carbonate, and 14g of epichlorohydrin were added to a 2L jacketed reactor and reacted at 70°C for 24 hours. After cooling to room temperature, the reaction product was filtered, and the resulting filtrate was washed with 700mL of chloroform and 500mL of water to concentrate the organic layer. 80g of the first intermediate product was obtained by high-vacuum distillation. 【0141】 In a 2L jacketed reactor, 100g of 2,2-bis(hydroxymethyl)propionic acid, 352g of 2-methoxyethyl chloride, 340g of potassium hydroxide, 1g of DABCO, and 500mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and the mixture was neutralized with 700mL of hydrochloric acid. The organic layer was concentrated. 150g of the second intermediate compound was obtained by high-vacuum distillation. 【0142】 In a 2L jacketed reactor, 100g of the first intermediate product, 33g of the second intermediate product, 2g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the organic layer was washed with 300mL of water and concentrated. High vacuum distillation yielded 95g of a fluorinated compound represented by the following chemical formula c. [Chemical formula c] [ka] 【0143】 Manufacturing Example 4: Production of fluorinated compounds 100 g of 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 42 g of potassium carbonate, and 14 g of epichlorohydrin were added to a 2 L jacketed reactor and reacted at 70°C for 24 hours. After cooling to room temperature, the reaction product was filtered, and the resulting filtrate was washed with 700 mL of chloroform and 500 mL of water to concentrate the organic layer. 63 g of the first intermediate product was obtained by high-vacuum distillation. 【0144】 In a 2L jacketed reactor, 100g of the first intermediate product obtained, 25g of 2,2-bis(hydroxymethyl)propionic acid, 2g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 70g of a fluorinated compound represented by the following chemical formula d. [Chemical formula d] [ka] 【0145】 Manufacturing Example 5: Production of fluorinated compounds In a 2L jacketed reactor, 100g of 2,2-bis(hydroxymethyl)propionic acid, 352g of 2-methoxyethyl chloride, 340g of potassium hydroxide, 1g of DABCO, and 500mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and neutralization was performed by adding 700mL of hydrochloric acid. The organic layer was concentrated. 150g of the first intermediate compound was obtained by high-vacuum distillation. 【0146】 In a 2L jacketed reactor, 100g of 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1-heptanol, 72g of the first intermediate product obtained above, 2g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 120g of a fluorine-based compound represented by the following chemical formula e. [Chemical formula e] [ka] 【0147】 Manufacturing Example 6: Production of fluorinated compounds In a 2L jacketed reactor, 20g of 2,2-bis(hydroxymethyl)propionic acid, 295g of 7-bromo-1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoroheptane, 67g of potassium hydroxide, 1g of DABCO, and 100mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and the mixture was neutralized with 700mL of hydrochloric acid to concentrate the organic layer. 90g of the first intermediate compound was obtained by high-vacuum distillation. 【0148】 In a 2L jacketed reactor, 50g of 2-(2-methoxyethoxy)-1-ethanol, 302g of the first intermediate product obtained above, 4g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 120g of a fluorinated compound represented by the following chemical formula f. [chemical formula f] [ka] 【0149】 Manufacturing Example 7: Production of fluorine-based compounds Into a 2 L jacketed reactor, 50 g of 2,2-bis(hydroxymethyl)propionic acid, 196 g of 7-bromo-1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoroheptane, 84 g of potassium hydroxide, 1 g of DABCO, and 100 mL of toluene were added, and reflux reaction was carried out for 24 hours. After cooling to room temperature, 500 mL of water was added to separate the aqueous layer, 500 mL of ethyl acetate was added, 700 mL of hydrochloric acid was added for neutralization, and the organic layer was concentrated. 90 g of the first intermediate compound was obtained by high-vacuum distillation. 【0150】 Into a 2 L jacketed reactor, 90 g of the first intermediate product obtained above, 42 g of 2-(2-methoxyethoxy)-1-ethanol, 46 g of potassium hydroxide, 1 g of DABCO, and 100 mL of toluene were added, and reflux reaction was carried out for 24 hours. After cooling to room temperature, 500 mL of water was added to separate the aqueous layer, 500 mL of ethyl acetate was added, 700 mL of hydrochloric acid was added for neutralization, and the organic layer was concentrated. 90 g of the second intermediate compound was obtained by high-vacuum distillation. 【0151】 Into a 2 L jacketed reactor, 50 g of 2-(2-methoxyethoxy)-1-ethanol, 217 g of the second intermediate product obtained above, 4 g of sulfuric acid, and 300 mL of xylene were added to maintain a reflux state, and the generated water was removed by a Dean-Stark Trap. After cooling at room temperature, it was washed with 300 mL of water, and the organic layer was concentrated. 200 g of a fluorine-based compound represented by the following chemical formula g was obtained by high-vacuum distillation. [Chemical formula g] 【Chemical formula】 【0152】 Production Example 8: Production of a fluorine-based compound Into a 2 L jacketed reactor, 100 g of 2-methoxyethanol, 182 g of potassium carbonate, and 61 g of epichlorohydrin were charged, and reacted at 70 °C for 24 hours. After cooling at room temperature, the filtrate obtained by filtering the reaction product was washed with 700 mL of chloroform and 500 mL of water, and the organic layer was concentrated. 65 g of the first intermediate product was obtained by high-vacuum distillation. 【0153】 In a 2L jacketed reactor, 50g of 2,2-bis(hydroxymethyl)propionic acid, 196g of 7-bromo-1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoroheptane, 84g of potassium hydroxide, 1g of DABCO, and 100mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and the mixture was neutralized with 700mL of hydrochloric acid to concentrate the organic layer. 90g of the second intermediate compound was obtained by high-vacuum distillation. 【0154】 In a 2L jacketed reactor, 90g of the second intermediate product obtained above, 42g of 2-(2-methoxyethoxy)-1-ethanol, 46g of potassium hydroxide, 1g of DABCO, and 100mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and the mixture was neutralized with 700mL of hydrochloric acid, and the organic layer was concentrated. 90g of the third intermediate compound was obtained by high-vacuum distillation. 【0155】 In a 2L jacketed reactor, 50g of the first intermediate compound obtained, 126g of the third intermediate compound, 4g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 120g of a fluorinated compound represented by the following chemical formula h. [Chemical formula h] [ka] 【0156】 Manufacturing Example 9: Production of fluorinated compounds In a 2L jacketed reactor, 100g of 2-methoxyethanol, 182g of potassium carbonate, and 61g of epichlorohydrin were added and reacted at 70°C for 24 hours. After cooling to room temperature, the reaction product was filtered, and the resulting filtrate was washed with 700mL of chloroform and 500mL of water to concentrate the organic layer. 65g of the first intermediate product was obtained by high-vacuum distillation. 【0157】 In a 2L jacketed reactor, 20g of 2,2-bis(hydroxymethyl)propionic acid, 295g of 7-bromo-1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoroheptane, 67g of potassium hydroxide, 1g of DABCO, and 100mL of toluene were added and the mixture was refluxed for 24 hours. After cooling to room temperature, 500mL of water was added to separate the aqueous layer, 500mL of ethyl acetate was added, and the mixture was neutralized with 700mL of hydrochloric acid. The organic layer was concentrated. 90g of the second intermediate compound was obtained by high-vacuum distillation. 【0158】 In a 2L jacketed reactor, 30g of the first intermediate compound, 105g of the second intermediate compound, 2g of sulfuric acid, and 300mL of xylene were added and reflux was maintained. The resulting water was removed using a Dean-Stark trap. After cooling to room temperature, the mixture was washed with 300mL of water, and the organic layer was concentrated. High vacuum distillation yielded 110g of a fluorinated compound represented by the following chemical formula i. [Chemical formula i] [ka] 【0159】 Manufacturing Example 10: Manufacturing of (meth)acrylic polyols In a 2L jacketed reactor, 132g of butyl acrylate, 420g of ethyl acrylate, and 48g of hydroxybutyl acrylate were added and diluted with 1200g of ethyl acetate. The reaction temperature was set to 60-70°C, and stirring was carried out for 30 minutes to 1 hour. 0.42g of n-dodecyl mercaptan (n-DDM) was added, and stirring was continued for another 30 minutes. Subsequently, 0.24g of AIBN, a polymerization initiator, was added, and polymerization was carried out at the reaction temperature for 4 hours or more, maintaining the residual acrylate content at less than 1%, to produce a (meth)acrylate copolymer with hydroxyl groups located in branched chains (weight-average molecular weight approximately 300,000, OH equivalent approximately 1802g / equivalent). 【0160】 Example 1: Manufacture of photopolymer composition and holographic recording medium 【0161】 (1) Production of photopolymer compositions 1.27 g of poly(methylhydrosiloxane) (manufactured by Sigma-Aldrich, number average molecular weight: approximately 390, Si-H equivalent: approximately 103 g / equivalent) as a siloxane polymer, and 11.12 g of (meth)acrylic polyol produced in Production Example 10 were mixed first (molar ratio of SiH / OH = 2.0). 【0162】 Then, 20 g of HR6042 (Miwon, refractive index 1.60) and 0.08 g of the photosensitive dye H-Nu640 (Spectra) were added as photoreactive monomers, 0.3 g of Borate V and 0.05 g of H-Nu254 (Spectra) were added as co-initiators, 10 g of the fluorine-based compound prepared in Production Example 1 was added as a plasticizer, and 26 g of methyl isobutyl ketone (MIBK) was added as a solvent. The mixture was then stirred in a Paste mixer for approximately 30 minutes while blocking out light. Subsequently, a Karstedt (Pt-based) catalyst was added to crosslink the matrix and produce a photopolymer composition. 【0163】 (2) Manufacturing of holographic recording media The aforementioned photopolymer composition was coated to a predetermined thickness onto a 60 μm thick TAC substrate using a Mayer bar, and dried at 80°C for 10 minutes. After drying, the thickness of the photopolymer layer was approximately 15 μm. 【0164】 A diffraction grating was recorded using the setup as shown in Fig. 1. Specifically, after laminating the manufactured photopolymer layer on a mirror and irradiating it with a laser, an interference between the incident light L and the light L' reflected by the mirror can record a Notch filter hologram having a periodic refractive index modulation in the thickness direction. In this example, the Notch filter hologram was recorded with an incident angle of 0° (degree). The Notch filter and the 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. 【0165】 Examples 2 to 11 and Comparative Examples 1 to 4: Production of Photopolymer Compositions and Hologram Recording Media Photopolymer compositions and hologram recording media were produced in the same manner as in Example 1, except that the components and contents of the photopolymer compositions were varied as described in Table 1 below. [Table 1] [Chemical formula j] [Chemical formula] [Chemical formula k] [Chemical formula] 【0166】 Test Example: Performance Evaluation of Hologram Recording Media 【0167】 (1) Diffraction Efficiency The diffraction efficiency (η) was determined by Equation 1 below. [Equation 1] η(%) = {P D / (P D + P T )} × 100 In Equation 1 above, η is the diffraction efficiency, P D is the output power (mW / cm 2 ) of the diffracted beam of the sample after recording, and P TThis is the output power (mW / cm²) of the beam transmitted through the sample after recording. 2 ) 【0168】 (2) Refractive index modulation value (△n) The refractive index modulation value (△n) was determined using Equation 2 and Bragg's equation below. [Formula 2] 【number】 [Bragg's equation] 【number】 【0169】 In the above formula, η is the reflectance 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 angle of incidence of the incident light for recording, φ is the slant angle of the grating, △n is the refractive index modulation value, n is the refractive index of the photopolymer, and Λ represents the period of the diffraction grating. In the above examples and comparative examples, the hologram was recorded using the Notch filter method, so θ (angle of incidence) and φ (slant angle of the grating) are all 0°. 【0170】 (3) Hayes 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 holographic recording medium. 【0171】 (4) Peak variation To evaluate the reliability of holographic recording media with diffraction gratings in high-temperature / high-humidity environments, we confirmed the degree of wavelength shift in the maximum reflectance of the diffraction grating-recorded samples before and after exposure to high-temperature / high-humidity conditions. 【0172】 First, the specific wavelength (or wavelength band) (A0) exhibiting the maximum reflectance (i.e., minimum transmittance) of the sample on which the diffraction grating was recorded was analyzed (analysis was performed at room temperature and under non-high humidity conditions). A UV-Vis spectrometer was used for the analysis, and the analysis wavelength range was 300 to 1,200 nm. 【0173】 Subsequently, the same sample was stored for 72 hours at a temperature of 60°C and a relative humidity of 90%, and the wavelength (or wavelength band) (A1) with the highest reflectivity (lowest transmittance) was recorded in the same manner. The peak variation, which represents the degree of shift in the wavelength with the lowest transmittance before and after evaluation, was measured using Equation 3 below. At this time, it was assumed that the deformation of the sample (e.g., shrinkage or expansion) did not affect the surface grid (pitch) and occurred only in the direction perpendicular to the sample surface. [Formula 3] Peak variation = {|1-A1 / A0|} x 100 【0174】 (5) Refractive index variation To evaluate the stability of holographic recording media in high-temperature / high-humidity environments before diffraction grating recording, the degree of refractive index change was examined before and after exposure of the sample to high-temperature / high-humidity conditions. 【0175】 Specifically, pre-recording hologram recording media, manufactured as in the examples and comparative examples, were stored under constant temperature (20-25°C) and humidity (40-50% relative humidity) conditions. Then, they were bleached with a white LED to prepare samples that had not been exposed to the high-temperature / high-humidity environment prior to recording. The refractive index n0 of these samples was then measured using a prism coupler (SPA-3DR, SAIRON TECHNOLOGY). 【0176】 On the other hand, the hologram recording media prepared as in the examples and comparative examples were stored for 72 hours at a temperature of 60°C and a relative humidity of 90%, and then bleached with a white LED to prepare samples exposed to the high temperature / high humidity environment before recording. The refractive index n1 of these samples was also measured using a prism coupler. 【0177】 The refractive index variation was calculated by substituting n0 and n1 into Equation 4 below. [Formula 4] Refractive index variation (%) = {|1-n1 / n0|} x 100 In Equation 4, n0 is the refractive index of a sample obtained by bleaching a hologram recording medium with a white LED after storing it at a temperature of 20-25°C and a relative humidity of 40-50% before recording, and n1 is the refractive index of a sample obtained by bleaching a hologram recording medium with a white LED after storing it at a temperature of 60°C and a relative humidity of 90% for 72 hours before recording. [Table 2] 【0178】 Referring to Table 2 above, it can be confirmed that the holographic recording media manufactured in Examples 1 to 11 exhibit excellent diffraction efficiency and refractive index modulation values ​​and low haze, while also demonstrating excellent reliability even after exposure to high temperature / high humidity environments before and after recording. In contrast, the holographic recording media manufactured in Comparative Examples 2 to 4 all exhibited poor optical recording characteristics, haze, and reliability in high temperature / high humidity environments. The holographic recording media manufactured in Comparative Example 1 had excellent optical recording characteristics, but showed high haze and poor reliability in high temperature / high humidity environments before and after recording. 【0179】 This confirms that using a fluorine-based compound according to one embodiment of the invention makes it possible to provide a holographic recording medium that exhibits excellent optical recording characteristics, superior reliability even in high-temperature / high-humidity environments, and high transparency.

Claims

[Claim 1] A plasticizer for holographic recording media containing a fluorine-based compound represented by the following chemical formula 1: [Chemical formula 1] 【Chemistry 1】 In the aforementioned chemical formula 1, Z １ is -O- or -NH-, Z ２ These are single bonds, -O- or -NH-, L １ is a single bond, or 【Chemistry 12】 And, L １ If it is a single bond, then n and m are each 1, and Z ２ It is also a single bond, L1 is 【Chemistry 12】 In this case, n is 2 and m is 1. R １ This is a methyl group or an ethyl group, R ２ ~R ４ At least one of these is a fluorine-containing substituent, which is a C1-C20 alkyl group substituted with two or more fluorines, a C3-C30 cycloalkyl group substituted with two or more fluorines, or a C6-C30 aryl group substituted with two or more fluorines. R ２ and R ３ When neither is a fluorine-containing substituent, each is independently hydrogen, 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 or -(R ５ -O) ｐ -R ６ where R ５ is an alkylene group having 1 to 6 carbon atoms, R ６ is an alkyl group having 1 to 6 carbon atoms, and p is an integer of 1 to 12. R ４ If it is not a fluorine-containing substituent, then a linear alkyl group having 2 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, or -(R ５ -O) ｐ -R ６ And R ５ R is an alkylene group having 1 to 6 carbon atoms. ６ p is an alkyl group having 1 to 6 carbon atoms, and p is an integer from 1 to 12. [Claim 2] The fluorine-containing substituent is a linear alkyl group having 1 to 20 carbon atoms substituted with two or more fluorines, as a plasticizer for a holographic recording medium according to claim 1. [Claim 3] The fluorine-containing substituent is -(CH ２ ) ａ (CF ２ ) ｂ CHF ２ or - (CH ２ ) ａ (CF ２ ) ｂ CF ３ The plasticizer for the hologram recording medium according to claim 1, wherein a is an integer from 0 to 3 and b is an integer from 0 to 19. [Claim 4] The fluorine-based compound represented by chemical formula 1 comprises one or more fluorine-based compounds selected from the group consisting of fluorine-based compounds represented by the following chemical formulas 1-1-1 to 1-1-5 and 1-2-1 to 1-2-5, wherein the plasticizer for the hologram recording medium according to claim 1: [Chemical formula 1-1-1] 【Chemistry 2】 In the aforementioned chemical formula 1-1-1, R ａ１ This is a methyl group or an ethyl group, R ｂ１ and R ｂ２ Each of these is independently hydrogen or an alkyl group having 1 to 4 carbon atoms. R ｃ１ CF ３ or CHF ２ And, Z ａ１ is -O- or -NH-, p1 and p2 are independent integers between 0 and 3, and q1 is an integer between 0 and 9. [Chemical formula 1-1-2] 【Transformation 3】 In the aforementioned chemical formula 1-1-2, R ａ２ This is a methyl group or an ethyl group, R ｂ３ and R ｂ４ These are, independently, a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R ｃ２ CF ３ or CHF ２ And, Z ａ２ is -O- or -NH-, q2 is an integer from 0 to 9. [Chemical formula 1-1-3] 【Chemistry 4】 In the aforementioned chemical formula 1-1-3, R ａ３ This is a methyl group or an ethyl group, R ｂ５ and R ｂ６ Each of them is independent of CF ３ or CHF ２ And, R ｃ３ These are alkyl groups having 1 to 4 carbon atoms. Z ａ３ is -O- or -NH-, p3 and p4 are independent integers between 0 and 9, and q3 is an integer between 0 and 3. [Chemical formula 1-1-4] 【Transformation 5】 In the aforementioned chemical formula 1-1-4, R ａ４ This is a methyl group or an ethyl group, R ｂ７ CF ３ or CHF ２ And, R ｃ４ and R ｃ５ Each of these is an alkyl group having 1 to 4 carbon atoms, Z ａ４ is -O- or -NH-, p5 is an integer between 0 and 9, and q4 and q5 are independently integers between 0 and 3. [Chemical formula 1-1-5] 【Transformation 6】 In the aforementioned chemical formula 1-1-5, R ａ５ This is a methyl group or an ethyl group, R ｂ８ CF ３ or CHF ２ And, R ｂ９ This is a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R ｃ６ These are alkyl groups having 1 to 4 carbon atoms. Z ａ５ is -O- or -NH-, p6 is an integer between 0 and 9, and q6 is an integer between 0 and 3. [Chemical formula 1-2-1] 【Transformation 7】 In the aforementioned chemical formula 1-2-1, R ａ６ This is a methyl group or an ethyl group, R ｂ１０ and R ｂ１１ Each of these is independently hydrogen or an alkyl group having 1 to 4 carbon atoms. R ｃ７ and R ｃ８ Each of them is independent of CF ３ or CHF ２ And, Z ａ６ is -O- or -NH-, p7 and p8 are each independent integers between 0 and 3, and q7 and q8 are each independent integers between 0 and 9. [Chemical formula 1-2-2] 【Transformation 8】 In the aforementioned chemical formula 1-2-2, R ａ７ This is a methyl group or an ethyl group, R ｂ１２ and R ｂ１３ Each of them is independent of CF ３ or CHF ２ And, R ｃ９ and R ｃ１０ Each of these is an alkyl group having 1 to 4 carbon atoms, Z ａ７ is -O- or -NH-, p9 and p10 are each independent integers between 0 and 9, and q9 and q10 are each independent integers between 0 and 3. [Chemical formula 1-2-3] 【Chemistry 9】 In the aforementioned chemical formula 1-2-3, R ａ８ This is a methyl group or an ethyl group, R ｂ１４ and R ｂ１５ These are, independently, a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R ｃ１１ and R ｃ１２ Each of them is independent of CF ３ or CHF ２ And, Z ａ８ is -O- or -NH-, q11 and q12 are each independent integers from 0 to 9. [Chemical formula 1-2-4] 【Chemistry 10】 In the aforementioned chemical formula 1-2-4, R ａ９ This is a methyl group or an ethyl group, R ｂ１６ CF ３ or CHF ２ And, R ｂ１７ This is a cyclohexyl group, a tetrahydropyranyl group, or a phenyl group. R ｃ１３ and R ｃ１４ are each independently an alkyl group having 1 to 4 carbon atoms, Z ａ９ is -O- or -NH-, p11 is an integer between 0 and 9, and q13 and q14 are independently integers between 0 and 3. [Chemical formula 1-2-5] 【Chemistry 11】 In the aforementioned chemical formula 1-2-5, R ａ１０ This is a methyl group or an ethyl group, R ｂ１８ CF ３ or CHF ２ And, R ｃ１５ ~R ｃ１７ Each of these is an alkyl group having 1 to 4 carbon atoms, Z ａ１０ is -O- or -NH-, p12 is an integer between 0 and 9, and q15 to q17 are each independent integers between 0 and 3. [Claim 5] Plasticizer for a holographic recording medium according to any one of claims 1 to 4; Polymer matrix or its precursor; A photopolymerizable composition comprising a photoreactive monomer and a photoinitiator system. [Claim 6] A holographic recording medium comprising a photopolymer layer formed from the photopolymerizable composition described in claim 5. [Claim 7] A method for manufacturing a hologram recording medium, comprising the steps of: applying the photopolymerizable composition described in claim 5 to form a photopolymer layer; and irradiating a predetermined region of the photopolymer layer with a coherent laser to selectively polymerize photoreactive monomers contained in the photopolymer layer to record optical information. [Claim 8] An optical element comprising a holographic recording medium as described in claim 6.

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