Fluorine-containing active energy ray-curable composition, cured product, and article

Abstract

To provide a fluorine-containing active energy ray-curable composition which can be cured by an active energy ray, can form a transparent cured product having a low refractive index and excellent steam resistance, and is excellent in handleability, a cured product thereof, and an article having the cured product.SOLUTION: (A) a fluoropolyether group-containing acrylic compound represented by the formula V1 - Rf1 - Z-Y (X) b (Rf1 is a divalent perfluoropolyether group); Z is a 2-valent organic group of a specific formula. Y is a (b + 1) - valent organic group; X is an acrylic group-containing monovalent organic group; V1 is H, F or -Z-Y (X) b. B is an integer of 1 to 10. A fluorine-containing active energy ray-curable composition comprising (B) an acrylic compound having a viscosity at 23 °C. of 5 000mPa·s or less and containing a fluoroalkyl group and an acrylic group, and (C) a photopolymerization initiator, wherein the fluorine-containing active energy ray-curable composition has a viscosity at 23 °C. of 10 to 100 000mPa·s and a refraction index at a temperature of 25 °C. and a wave length of 589nm of 1.390 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fluorine-containing active energy ray-curable composition that can form a transparent cured product having a low refractive index and excellent water vapor resistance and that is easy to handle, a cured product of the composition, and an article having the cured product. [Background technology]

[0002] Conventionally, polymerizable monomers having a perfluoroalkyl group in the side chain, such as polymers containing a fluorine-containing alkyl ester of acrylic acid or a fluorine-containing alkyl ester of methacrylic acid, have been widely known as fluorine compounds that can be cured by irradiation with light such as ultraviolet light. These fluorine-containing acrylic compounds have been widely used in optical materials, taking advantage of their excellent curing properties upon irradiation with ultraviolet light, high transparency, and low refractive index. For example, Japanese Patent Laid-Open Publication No. 6-136062 (Patent Document 1) discloses the application of fluorine-containing acrylic compounds in the side chain to antireflection coatings, and Japanese Patent Laid-Open Publication No. 5-32749 (Patent Document 2) discloses their use as coating materials for optical fibers.

[0003] On the other hand, when the fluorine content of these fluorine-containing acrylic compounds is increased for the purpose of further lowering the refractive index, etc., the solubility in non-fluorinated organic compounds decreases, and the compounds become insoluble in general photopolymerization initiators, making it impossible to obtain a transparent cured product, or the crystallinity increases, resulting in a loss of transparency, and it has been difficult to obtain a transparent cured product having a refractive index of a certain value or less.

[0004] Under these circumstances, the present inventors have been developing fluorine-containing acrylic compounds, and have proposed, for example, a fluorine-containing curable composition as disclosed in Japanese Patent Application Laid-Open No. 2006-233172 (Patent Document 3) that can be cured with ultraviolet light and can form a transparent cured product having a low refractive index.

[0005] Although these compositions can form transparent cured products with low refractive indexes, the cured products suffer from a significant deterioration in mechanical properties upon exposure to water vapor, and these compositions also have the problem of requiring the separate synthesis of a photopolymerization initiator modified with a perfluoropolyether group. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-136062 [Patent Document 2] Japanese Patent Application Publication No. 5-32749 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-233172 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluorine-containing active energy ray-curable composition that can be cured with active energy rays such as ultraviolet rays or electron beams, can form a transparent cured product that has a low refractive index and excellent water vapor resistance, and has excellent handleability, a cured product of the composition, and an article having the cured product. [Means for solving the problem]

[0008] As a result of further investigations to achieve the above object, the present inventors have found that (A) 100 parts by mass of a fluoropolyether group-containing acrylic compound represented by the following general formula (1): V 1 -Rf 1 -ZY(X) b (1) (In the formula, Rf 1is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000 and composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom. Z is a divalent organic group which may contain a cyclic structure along the chain. Y is a (b+1)-valent organic group having 1 to 20 carbon atoms. X is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains at least one of the acrylic group or α-substituted acrylic group on average per molecule. V 1 is a hydrogen atom, a fluorine atom, or -ZY(X) b and b is an integer of 1 to 10. (B) 0.1 to 300 parts by mass of an acrylic compound (excluding component (A)) having a viscosity at 23°C of 5,000 mPa s or less and containing one or two acrylic groups or α-substituted acrylic groups per molecule, and (C) Photopolymerization initiator 0.01 to 20 parts by mass The present inventors have found that a fluorine-containing active energy ray-curable composition containing the above as an essential component, having a viscosity at 23°C in the range of 10 to 100,000 mPa s, and having a refractive index of 1.390 or less at a temperature of 25°C and a wavelength of 589 nm, can be cured by active energy rays such as ultraviolet light or electron beams, can form a transparent cured product having a low refractive index and excellent water vapor resistance, and can be a fluorine-containing active energy ray-curable composition with excellent handleability, and have achieved the present invention.

[0009] Accordingly, the present invention provides the following fluorine-containing active energy ray-curable composition, a cured product of the composition, and an article having the cured product. [1] (A) a fluoropolyether group-containing acrylic compound represented by the following general formula (1): V 1 -Rf 1 -ZY(X) b (1) (In the formula, Rf 1is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000, which is composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and has perfluoroalkylene groups having 2 to 6 carbon atoms at both ends. Z is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000, which is represented by the following formula: [ka] [ka] [ka] [ka] [ka] (In the formula, R is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms. Y and X are the same as Y and X described below. In the formula, * indicates Rf 1 is the bond that bonds to , and ** is the bond that bonds to Y.) Y is a (b+1)-valent organic group having 1 to 20 carbon atoms. X is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains an average of at least one acrylic group or α-substituted acrylic group per molecule. V 1 is a hydrogen atom, a fluorine atom, or -ZY(X) b and b is an integer of 1 to 10. (B) an acrylic compound (excluding component (A)) having a viscosity of 5,000 mPa·s or less at 23°C, containing a fluoroalkyl group and one or two acrylic groups or α-substituted acrylic groups in each molecule, and (C) Photopolymerization initiator as an essential component, and has a viscosity at 23°C in the range of 10 to 100,000 mPa·s, and a refractive index at a temperature of 25°C and a wavelength of 589 nm of 1.390 or less. [2] The fluorine-containing active energy ray-curable composition according to [1], wherein the amount of the component (B) is 0.1 to 300 parts by mass and the amount of the component (C) is 0.01 to 20 parts by mass per 100 parts by mass of the component (A). [3] The fluorine-containing active energy ray-curable composition according to [1], which does not contain a non-fluorinated acrylic compound. [4] The fluorine-containing active energy ray-curable composition according to [1], which does not contain a volatile organic compound having no group reactive with an acrylic group. [5] The fluorine-containing active energy ray-curable composition according to [1], which is a solvent-free system. [6] In general formula (1), Rf 1 is expressed as follows: [ka] (In the formula, c is independently an integer of 2 to 6 for each unit. d, e, f, g, h, and i are each an integer of 0 to 200, and d+e+f+g+h+i=4 to 200. Each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.) The fluorine-containing active energy ray-curable composition according to [1], wherein the divalent perfluoropolyether group is represented by the following formula: [7] The fluorine-containing active energy ray-curable composition according to [1], wherein the component (A) is a fluoropolyether group-containing acrylic compound represented by the following general formula (2): V 2 -Rf 2 -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a (2) (In the formula, Rf 2is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000, which is composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and has perfluoroalkylene groups having 2 to 6 carbon atoms at both ends. 2 are independently (b'+1)-valent organic groups having 1 to 20 carbon atoms. 2 R is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains an average of at least one such acrylic group or α-substituted acrylic group per molecule. 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms. 2 is a hydrogen atom, a fluorine atom, or -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a a is 0 or 1, and b' is an integer of 1 to 10. [8] In general formula (2), Rf 2 is expressed as follows: [ka] (In the formula, c is independently an integer of 2 to 6 for each unit. d, e, f, g, h, and i are each an integer of 0 to 200, and d+e+f+g+h+i=4 to 200. Each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.) The fluorine-containing active energy ray-curable composition according to [7], wherein the divalent perfluoropolyether group is represented by the following formula: [9] In general formula (2), Rf 2 is the following structural formula -CF2CF2O-(CF2CF2CF2O) q -CF2CF2- (In the formula, q is an integer of 4 to 200.) [ka] (wherein r is an integer of 1 to 6, and Cr F 2r O may be linear or branched, s is an integer of 0 to 6, t and u are each an integer of 1 to 200, t+u is an integer of 2 to 200, and s+t+u is an integer of 4 to 200. v is an integer of 5 to 200. The fluorine-containing active energy ray-curable composition according to [7], wherein the divalent perfluoropolyether group is selected from divalent perfluoropolyether groups represented by the following formula:

[10] In general formula (2), R 1 [7] The fluorine-containing active energy ray-curable composition according to [7], wherein is a hydrogen atom and a is 1.

[11] In general formula (2), Y 2 The fluorine-containing active energy ray-curable composition according to [7], wherein is a hydrocarbon group having 1 to 20 carbon atoms and a valence of (b'+1).

[12] In general formula (2), Y 2 The fluorine-containing active energy ray-curable composition according to [7], wherein: [ka] (In the formula, * represents a bond bonded to N, and ** represents X 2 )

[13] In general formula (2), X 2 is the following structural formula [ka] (In the formula, R 2 are independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; W is a single bond, or a divalent or trivalent hydrocarbon group which may contain one or more bonds selected from an ether bond, an ester bond, and a urethane bond; and n is 1 or 2. The fluorine-containing active energy ray-curable composition according to [7], which is represented by the following formula:

[14] The fluorine-containing active energy ray-curable composition according to [1], wherein the component (B) is an acrylic compound represented by any one of the following formulas: [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[15] The fluorine-containing active energy ray-curable composition according to [1], wherein component (B) contains one or more perfluoroalkyl groups having 1 to 8 carbon atoms and one or two acrylic groups or α-substituted acrylic groups.

[16] The fluorine-containing active energy ray-curable composition according to [1], wherein the component (B) is an acrylic compound represented by any one of the following formulas: [ka] [ka] [ka]

[17] The fluorine-containing active energy ray-curable composition according to [1], wherein the photopolymerization initiator (C) does not contain a fluorine atom in its structure.

[18] The fluorine-containing active energy ray-curable composition according to [1], which is used as an antireflection agent or a coating agent for optical fibers.

[19] A cured product obtained by curing the fluorine-containing active energy ray-curable composition according to any one of [1] to

[18] .

[20] The cured product according to

[19] , which has a refractive index of 1.400 or less at a temperature of 25°C and a wavelength of 589 nm. [twenty one] The cured product according to

[19] , wherein the change in hardness after heating for 12 hours under conditions of 95°C and 100% RH is within ±10 points of the initial value. [twenty two] An article comprising the cured product according to

[19] as the entire or at least part of its configuration. [twenty three] The article according to

[22] , which is an optical component. [twenty four] The article according to

[22] , which is any one of a lens, an anti-reflection film, and an optical fiber. [Effects of the Invention]

[0010] The fluorine-containing active energy ray-curable composition of the present invention can be cured by active energy rays such as ultraviolet rays and electron beams, can form a transparent cured product having a low refractive index and excellent water vapor resistance, and has excellent handleability. Therefore, the fluorine-containing active energy ray-curable composition of the present invention is useful as an antireflection agent, a coating agent for optical fibers, and a material for various optical components such as lenses. DETAILED DESCRIPTION OF THE INVENTION

[0011] The fluorine-containing active energy ray-curable composition of the present invention comprises (A) 100 parts by mass of a fluoropolyether group-containing acrylic compound represented by the following general formula (1): V 1 -Rf 1 -ZY(X) b (1) (In the formula, Rf 1is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000 and composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom. Z is a divalent organic group which may contain a cyclic structure along the chain. Y is a (b+1)-valent organic group having 1 to 20 carbon atoms. X is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains at least one of the acrylic group or α-substituted acrylic group on average per molecule. V 1 is a hydrogen atom, a fluorine atom, or -ZY(X) b and b is an integer of 1 to 10. (B) 0.1 to 300 parts by mass of an acrylic compound (excluding component (A)) having a viscosity at 23°C of 5,000 mPa s or less and containing one or two acrylic groups or α-substituted acrylic groups per molecule, and (C) Photopolymerization initiator 0.01 to 20 parts by mass as an essential component, and characterized by a viscosity at 23°C in the range of 10 to 100,000 mPa·s, and a refractive index at a temperature of 25°C and a wavelength of 589 nm of 1.390 or less.

[0012] The fluorine-containing active energy ray-curable composition of the present invention can be cured by active energy rays such as ultraviolet rays and electron beams, and can form a transparent cured product having a low refractive index and excellent water vapor resistance, since the fluoropolyether group-containing acrylic compound of component (A) has a perfluoropolyether group as a group having a low refractive index and water vapor resistance, and an acrylic group or an α-substituted acrylic group.

[0013] The fluoropolyether group-containing acrylic compound of component (A), which is the first essential component in the fluorine-containing active energy ray-curable composition of the present invention, is represented by the following general formula (1). V 1 -Rf 1 -ZY(X) b (1) In the present invention, "acrylic compound" is a general term for compounds having an acrylic group or an α-substituted acrylic group, and includes compounds in which two or more acrylic groups or α-substituted acrylic groups have been introduced into the side chains or ends of various polymers by any method. Furthermore, in the present invention, "(meth)acrylate" refers to either or both of acrylate and methacrylate, "(meth)acrylic group" refers to either or both of an acrylic group and a methacrylic group, and "(meth)acrylic acid" refers to either or both of acrylic acid and methacrylic acid.

[0014] In the above formula (1), Rf 1 is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000 and consisting of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and Rf 1 The alkylene group preferably has a perfluorooxyalkylene structure having 1 to 6 carbon atoms, particularly the following perfluorooxyalkylene structure having 1 to 3 carbon atoms, as the main repeating unit. -CF2O- -CF2CF2O- -CF(CF3)CF2O- -CF2CF2CF2O- These structures may be any one homopolymer, or a random or block polymer consisting of a plurality of structures.

[0015] Rf having such a structure 1 Examples of the above include the following structures: [ka] (In the formula, c is independently an integer of 2 to 6 for each unit. d, e, f, g, h, and i are each an integer of 0 to 200, and d+e+f+g+h+i=4 to 200. Each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.)

[0016] In the above formula, c is independently for each unit an integer of 2 to 6, preferably 2 to 4. When c is 1, the water vapor resistance decreases, so c is preferably independently for each unit an integer of 2 to 6. Furthermore, d, e, f, g, h, and i are each an integer of 0 to 200, preferably d is an integer of 0 to 100, e is an integer of 5 to 100, f is an integer of 5 to 100, g is an integer of 0 to 100, h is an integer of 0 to 100, and i is an integer of 0 to 100, and d+e+f+g+h+i=4 to 200, preferably 10 to 150, and more preferably 30 to 150. In the above formula, each unit may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be randomly bonded.

[0017] Rf 1 The number-average molecular weight of the corresponding structural portion is required to be within the range of 500 to 40,000, preferably 2,000 to 25,000, and the molecular weight distribution (or polymerization degree distribution) is not particularly limited. If the number-average molecular weight is less than 500, the refractive index will increase due to a decrease in the fluorine atom content, and if it exceeds 40,000, the handleability will decrease due to an increase in viscosity, and the compatibility with the polymerization initiator will decrease to a non-negligible extent due to an increase in the fluorine atom content. In the present invention, the molecular weight (or polymerization degree or number of repeating units) may be determined as the polystyrene-equivalent number-average molecular weight (or number-average polymerization degree) by gel permeation chromatography (GPC) analysis using a fluorine-based solvent as the developing solvent, 1 H-NMR analysis and 19 It may also be a number average molecular weight (or number average degree of polymerization) calculated from the characteristic peak intensity ratio between the terminal structure and main chain structure of the fluoropolyether group-containing acrylic compound based on F-NMR analysis.

[0018] In the above formula (1), Z is a divalent organic group, which may contain a cyclic structure in the middle. Examples of Z include the structures shown below. [ka] [ka] [ka] [ka] [ka] [ka] (In the formula, R is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms. Y and X are the same as Y and X described below. In the formula, * indicates Rf 1 is the bond that bonds to , and ** is the bond that bonds to Y.)

[0019] In the above formula (1), Y is a (b+1)-valent organic group having 1 to 20 carbon atoms, preferably 1 to 8. Examples of Y include the following. [ka] [ka] (In the formula, * represents a bond bonded to Z, and ** represents a bond bonded to X.)

[0020] In the above formula (1), X is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains on average at least one such acrylic group or α-substituted acrylic group per molecule.

[0021] X is preferably a structure represented by the following formula: [ka] [ka] [ka]

[0022] In the above formula (1), V 1 is a hydrogen atom, a fluorine atom, or -ZY(X) b is a monovalent group represented by the formula: b It is a monovalent group represented by the formula: V 1 -ZY(X) b When the compound is a monovalent group represented by the formula (V), the compound contains an average of at least two acrylic groups or α-substituted acrylic groups per molecule, so that the composition forms a mesh-like network and a cured product having excellent mechanical properties can be obtained. 1 -ZY(X) b In the case where the group is a monovalent group represented by the formula (1), the plurality of Z, Y, X and b's present in the formula (1) may be the same or different.

[0023] In the above formula (1), b is an integer of 1 to 10, and is preferably 1 or 2.

[0024] The fluoropolyether group-containing acrylic compound represented by formula (1) of component (A) is preferably one represented by the following general formula (2). V 2 -Rf 2 -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a (2)

[0025] When the fluoropolyether group-containing acrylic compound of component (A) is represented by general formula (2), Rf 2 At least one of the ends of Rf is bonded to an amide structure. 2The terminal portion of the amide bond is highly reactive due to the electron-withdrawing property of the fluorine atom, and is prone to hydrolysis. On the other hand, when a cured product made from the composition of the present invention is exposed to water vapor, hydrolysis is unlikely to occur due to the high bond energy of the amide bond, resulting in particularly excellent water vapor resistance, which is preferable.

[0026] Furthermore, when the fluoropolyether group-containing acrylic compound of component (A) has an amide bond, the amide structure acts as a hydrogen bond acceptor, thereby improving compatibility with the photopolymerization initiator through interaction with hydrogen atoms in the photopolymerization initiator, and as a result, a transparent composition can be formed, which is preferable.

[0027] In the above formula (2), Rf 2 is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000 and consisting of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and Rf 1 The alkylene group preferably has a perfluorooxyalkylene structure having 1 to 6 carbon atoms, particularly the following perfluorooxyalkylene structure having 1 to 3 carbon atoms, as the main repeating unit. -CF2O- -CF2CF2O- -CF(CF3)CF2O- -CF2CF2CF2O- These structures may be any one homopolymer, or a random or block polymer consisting of a plurality of structures.

[0028] Rf having such a structure 2 Examples of the above include the following structures: [ka] (In the formula, c is independently an integer of 2 to 6 for each unit. d, e, f, g, h, and i are each an integer of 0 to 200, and d+e+f+g+h+i=4 to 200. Each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.)

[0029] In the above formula, c is independently for each unit an integer of 2 to 6, preferably 2 to 4. When c is 1, the water vapor resistance decreases, so c is preferably independently for each unit an integer of 2 to 6. Furthermore, d, e, f, g, h, and i are each an integer of 0 to 200, preferably d is an integer of 0 to 100, e is an integer of 5 to 100, f is an integer of 5 to 100, g is an integer of 0 to 100, h is an integer of 0 to 100, and i is an integer of 0 to 100, and d+e+f+g+h+i=4 to 200, preferably 10 to 150, and more preferably 30 to 150. In the above formula, each unit may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be randomly bonded.

[0030] Rf 2 The number-average molecular weight of the corresponding structural portion is required to be within the range of 500 to 40,000, preferably 2,000 to 25,000, and the molecular weight distribution (or polymerization degree distribution) is not particularly limited. If the number-average molecular weight is less than 500, the refractive index will increase due to a decrease in the fluorine atom content, and if it exceeds 40,000, the handleability will decrease due to an increase in viscosity, and the compatibility with the polymerization initiator will decrease to a non-negligible extent due to an increase in the fluorine atom content. In the present invention, the molecular weight (or polymerization degree or number of repeating units) may be determined as the polystyrene-equivalent number-average molecular weight (or number-average polymerization degree) by gel permeation chromatography (GPC) analysis using a fluorine-based solvent as the developing solvent, 1 H-NMR analysis and 19 It may also be a number average molecular weight (or number average degree of polymerization) calculated from the characteristic peak intensity ratio between the terminal structure and main chain structure of the fluoropolyether group-containing acrylic compound based on F-NMR analysis.

[0031] Rf having such a structure 2 Suitable examples of the above include the following structures: -CF2CF2O-(CF2CF2CF2O) q -CF2CF2- (In the formula, q is an integer of 4 to 200, preferably 10 to 150.) [ka] (wherein r is an integer of 1 to 6, preferably an integer of 2 to 4, and C r F 2r O may be linear or branched, s is an integer of 0 to 6, preferably an integer of 1 to 4, t is an integer of 1 to 100, preferably an integer of 5 to 80, u is an integer of 1 to 100, preferably an integer of 5 to 80, t+u is an integer of 2 to 200, preferably an integer of 10 to 150, s+t+u is an integer of 4 to 200, preferably an integer of 10 to 150, and v is an integer of 5 to 200, preferably an integer of 10 to 150.

[0032] Rf 2 The most preferred example of Rf is the following structure: 2 The terminal part of Rf is highly reactive due to the electron-withdrawing property of the fluorine atom and is prone to hydrolysis. 2 If Rf has the following structure: 2 Since the terminal portion of is shielded with a C2F4 group, more preferably a CF(CF3) group, hydrolysis is unlikely to occur, resulting in excellent water vapor resistance, which is particularly preferred. [ka] (wherein r, s, t, u, and v are the same as above.)

[0033] In the above formula (2), R 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, preferably 1 to 6. Specific examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, and octyl, cycloalkyl groups such as cyclohexyl, alkenyl groups such as vinyl, allyl, and propenyl, aryl groups such as phenyl, tolyl, and xylyl, and aralkyl groups such as benzyl and phenylethyl. 1is preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a hydrogen atom.

[0034] In the above formula (2), Y 2 are independently a (b'+1)-valent organic group having 1 to 20 carbon atoms, preferably 1 to 8, and are preferably a (b'+1)-valent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 8, which may contain an ether bond. 2 Particularly preferred structures include the following: [ka] (In the formula, * represents a bond bonded to N, and ** represents X 2 )

[0035] In the above formula (2), X 2 are independently monovalent organic groups containing an acrylic group or an α-substituted acrylic group, and contain on average at least one such acrylic group or α-substituted acrylic group per molecule.

[0036] X 2 As the alkyl group, a structure represented by the following formula is preferred. [ka] (In the formula, R 2 are independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; W is a single bond, or a divalent or trivalent hydrocarbon group which may contain one or more bonds selected from an ether bond, an ester bond, and a urethane bond; and n is 1 or 2.

[0037] In the above formula, W is a single bond or a divalent or trivalent hydrocarbon group which may contain one or more bonds selected from an ether bond, an ester bond, and a urethane bond. Examples of the divalent or trivalent hydrocarbon group include groups represented by the following formula: [ka] (where * represents Y in general formula (2) 2 is the bond to the oxygen atom, and ** is the bond to the oxygen atom.)

[0038] X 2 As the alkyl group, a structure represented by the following formula is more preferred. [ka]

[0039] In the above formula (2), V 2 is a hydrogen atom, a fluorine atom, or -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a and preferably -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a It is a monovalent group represented by the formula: V 2 -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a When the compound is a monovalent group represented by the formula (V), it contains an average of at least two acrylic groups or α-substituted acrylic groups per molecule, so that a composition using the compound forms a mesh-like network, and a cured product having excellent mechanical properties can be obtained. 2 -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a When the group is a monovalent group represented by 1 , Y 2 , X 2 , b', and a may be the same or different.

[0040] In the above formula (2), a is 0 or 1, and is preferably 1. In the above formula (2), b' is an integer of 1 to 10, and is preferably 1 or 2.

[0041] The fluoropolyether group-containing acrylic compound represented by the above formula (2) is preferably one represented by the following formula: [ka] (In the formula, X 2 , q, r, s, t, u are the same as above.)

[0042] As the fluoropolyether group-containing acrylic compound represented by the above formula (2), the compound represented by the following formula is particularly preferred. [ka] (In the formula, X 2 , r, s, t, u are the same as above.)

[0043] In the fluoropolyether group-containing acrylic compound represented by the general formula (1), which is the component (A), particularly the fluoropolyether group-containing acrylic compound represented by the formula (2), for example, V 2 -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a A monovalent group represented by the following general formula (3): Rf 2 [C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a ]2(3) (In the formula, Rf 2 , R 1 , Y 2 , X 2 , a, b' are the same as above.) A suitable method for synthesizing a fluoropolyether group-containing acrylic compound represented by the following general formula (4) is, for example, Rf 2 [C(=O)-X 3 ]2(4) (In the formula, Rf 2 is the same as above, and X 3 is a halogen atom or an unsubstituted or fluorine-substituted alkoxy group. A fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal, represented by the following general formula (5): H-NR 1 a [Y 2 [OH] b’ ] 2-a (5) (In the formula, R 1 , Y 2 , a, b' are the same as above.) An intermediate fluoropolyether group-containing alcohol compound is obtained by amidating an amino alcohol compound represented by the following formula:

[0044] Here, X in the above formula (4) 3 is a halogen atom, or an unsubstituted or fluorine-substituted alkoxy group preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. Specific examples include halogen atoms such as fluorine, chlorine, and bromine; alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, hexyloxy, and octyloxy; and fluorine-substituted alkoxy groups in which some or all of the hydrogen atoms in these groups have been substituted with fluorine atoms, such as a trifluoromethoxy group, a 2,2,2-trifluoroethoxy group, and a 1,1,1,3,3,3-hexafluoroisopropoxy group.

[0045] Specific examples of the fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal, represented by the above formula (4), include the compounds shown below. Rf 2 [C(=O)-Cl]2 Rf 2[C(=O)-F]2 Rf 2 [C(=O)-O-CH3]2 Rf 2 [C(=O)-O-C2H5]2 Rf 2 [C(=O)-O-C3H7]2 Rf 2 [C(=O)-O-C4H9]2 Rf 2 [C(=O)-O-CH 11 ]2 Rf 2 [C(=O)-O-CH 13 ]2 Rf 2 [C(=O)-O-CF3]2 Rf 2 [C(=O)-O-C2F5]2 Rf 2 [C(=O)-O-CH(CF3)2]2 (In the formula, Rf 2 is the same as above.)

[0046] Examples of the amino alcohol compound represented by the above formula (5) include the compounds shown below. [ka] [ka] [ka] [ka]

[0047] The reaction ratio of the fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal represented by formula (4) with the amino alcohol compound represented by formula (5) is preferably 1 to 12 times, and more preferably 1.2 to 6 times, the molar amount of the amino alcohol compound represented by formula (5) relative to the total number of moles of the acid halide or ester groups in the fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal represented by formula (4). If the amount of the amino alcohol compound represented by formula (5) is less than this, it may be difficult to obtain the desired fluoropolyether group-containing alcohol compound.

[0048] This amidation reaction is preferably carried out by mixing a fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal, represented by formula (4), with an amino alcohol compound represented by formula (5), and carrying out the reaction at a reaction temperature of 0 to 100°C, preferably 0 to 80°C, for 1 minute to 48 hours, and particularly 10 minutes to 12 hours. If the reaction temperature is too low, the reaction may stop before proceeding sufficiently, while if the reaction temperature is too high, undesired side reactions or decomposition of the raw materials may occur.

[0049] The amidation reaction can be carried out in the absence of a solvent, but may be diluted with a solvent if necessary. In this case, any commonly used organic solvent can be used as the dilution solvent, but it is preferable to use one whose boiling point is equal to or higher than the target reaction temperature and which does not inhibit the reaction. Examples of such solvents include partially fluorinated solvents, such as fluorinated aromatic hydrocarbon solvents (e.g., m-xylene hexafluoride, benzotrifluoride, etc.) and fluorinated ether solvents (e.g., methyl perfluorobutyl ether, etc.), with m-xylene hexafluoride being particularly preferred. When a solvent is used, the amount used is preferably 5 to 2,000 parts by mass, more preferably 50 to 500 parts by mass, relative to 100 parts by mass of the fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal, as represented by formula (4). If the amount is less than this, the effect of dilution by the solvent becomes weak, and if the amount is more, the degree of dilution becomes too high, which may lead to a decrease in the reaction rate.

[0050] After the reaction is completed, it is preferable to remove the unreacted amino alcohol compound represented by formula (5) and the dilution solvent by a known method such as vacuum distillation, extraction, or adsorption.

[0051] In this way, by subjecting a fluoropolyether group-containing compound having an acid halide or ester at the molecular chain terminal represented by general formula (4) to an amidation reaction with an amino alcohol compound represented by general formula (5), a fluoropolyether group-containing alcohol compound represented by the following general formula (6) can be obtained. Rf 2 [C(=O)-NR 1 a [Y 2 [OH] b’ ] 2-a ]2(6) (In the formula, Rf 2 , R 1 , Y 2 , a, b' are the same as above.)

[0052] Examples of such fluoropolyether group-containing alcohol compounds represented by formula (6) include those shown below. [ka] [ka] [ka] [ka] (In the formula, Rf 2 is the same as above.)

[0053] Next, by introducing a (meth)acrylic group into the fluoropolyether group-containing alcohol compound represented by formula (6) obtained above, the desired fluoropolyether group-containing acrylic compound represented by formula (3) can be obtained.

[0054] A method for introducing a (meth)acrylic group into a fluoropolyether group-containing alcohol compound represented by formula (6) includes reacting the fluoropolyether group-containing alcohol compound represented by formula (6) with an isocyanate compound containing a (meth)acrylic group.

[0055] Examples of the isocyanate compound containing a (meth)acrylic group include the following. [ka]

[0056] The isocyanate compound containing (meth)acrylic groups may be charged in an amount equal to or greater than the total amount of hydroxyl groups in the fluoropolyether group-containing alcohol compound and reacted to react all of the hydroxyl groups. Alternatively, an average of 1 mole or more of (meth)acrylic groups may be introduced per mole of the fluoropolyether group-containing alcohol compound. By using an excess of hydroxyl groups, it is possible to prevent unreacted isocyanate compounds containing (meth)acrylic groups from remaining. Specifically, if the amount of fluoropolyether group-containing alcohol compounds in the reaction system is x moles and the total amount of hydroxyl groups in the fluoropolyether group-containing alcohol compounds is y moles, the amount of isocyanate compounds containing (meth)acrylic groups is preferably at least x moles but not more than 2y moles, and particularly preferably at least x moles but not more than 0.6y moles but not more than 1.4y moles. If the amount is too small, there is a high possibility that fluoropolyether group-containing alcohol compounds without any (meth)acrylic groups will remain. If the amount is too large, it becomes difficult to remove unreacted isocyanate compounds containing (meth)acrylic groups.

[0057] In addition, during the reaction, the reaction may be carried out by diluting with an appropriate solvent as needed. Such a solvent can be used without any particular limitation as long as it does not react with the hydroxyl group of the fluoropolyether group-containing alcohol compound or the isocyanate group of the isocyanate compound containing a (meth)acrylic group. Specific examples include hydrocarbon solvents such as toluene, xylene, and isooctane; ether solvents such as tetrahydrofuran (THF), diisopropyl ether, and dibutyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, and cyclohexanone; fluorine-modified aromatic hydrocarbon solvents such as m-xylene hexafluoride (also known as hexafluorometa-xylene) and benzotrifluoride; and fluorine-modified ether solvents such as methyl perfluorobutyl ether. The solvent may be removed after the reaction by a known method such as vacuum distillation. The amount of solvent used is not particularly limited, but is preferably 10 times or less the total mass of all the reaction components. If the amount of solvent used is too large, the reaction rate may decrease significantly.

[0058] Furthermore, during the reaction, a polymerization inhibitor may be added as necessary. There are no particular limitations on the polymerization inhibitor, but those typically used as polymerization inhibitors for acrylic compounds can be used. Specific examples include hydroquinone, hydroquinone monomethyl ether, 4-tert-butylcatechol, and dibutylhydroxytoluene. The amount of polymerization inhibitor used can be determined based on the reaction conditions, post-reaction purification conditions, and final use conditions, and is not particularly limited, but is usually 0.01 to 5,000 ppm, particularly preferably 0.1 to 500 ppm, based on the total mass of the reaction components.

[0059] During the reaction, a suitable catalyst may be added to increase the reaction rate. Examples of the catalyst include alkyltin ester compounds such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctoate, dioctyltin diacetate, dioctyltin dilaurate, dioctyltin dioctate, and stannous dioctanoate; titanate esters or titanium chelate compounds such as tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium [also known as tetrakis(2-ethylhexyl) orthotitanate], dipropoxybis(acetylacetonate)titanium, and titanium isopropoxyoctylene glycol; zirconium tetraacetylacetonate, zirconium tributoxymonoacetylacetonate, zirconium monobutoxyacetylacetonate bis(ethylacetoacetate), zirconium dibutoxybis(ethylacetoacetate), zirconium tetraacetylacetonate, zirconium chelate, and bismuth carboxylate compounds. These compounds are not limited to one type, and can be used as a mixture of two or more types. However, from the viewpoint of toxicity and reactivity, titanium compounds and bismuth compounds are particularly preferred. The reaction rate can be increased by adding these catalysts in an amount of 0.01 to 2 mass %, preferably 0.05 to 1 mass %, based on the total mass of the reaction components.

[0060] The reaction is carried out at a temperature of 0 to 120°C, preferably 10 to 100°C, for 1 minute to 500 hours, preferably 10 minutes to 48 hours. If the reaction temperature is too low, the reaction rate may be too slow, whereas if the reaction temperature is too high, polymerization of the (meth)acrylic group may occur as a side reaction.

[0061] After the reaction is completed, the unreacted isocyanate compound and the solvent are removed by distillation, adsorption, filtration, washing or other methods, to obtain the fluoropolyether group-containing acrylic compound represented by the above formula (3).

[0062] Furthermore, when the reaction is stopped, an alcohol compound such as methanol or ethanol may be added to the system to form a urethane bond with the unreacted isocyanate compound. The urethane (meth)acrylates formed can be removed in the same manner as the unreacted isocyanate compound, but they can also be used as they remain.

[0063] Another method for introducing a (meth)acrylic group into the fluoropolyether group-containing alcohol compound represented by formula (6) is to react the fluoropolyether group-containing alcohol compound represented by formula (6) with a (meth)acrylic acid halide to form an ester.

[0064] Examples of the (meth)acrylic acid halide include the following. [ka] (In the formula, X 4 is a halogen atom such as fluorine, chlorine, or bromine.) Acrylic acid chloride and methacrylic acid chloride are particularly preferred.

[0065] It is desirable to charge and react (meth)acrylic acid halide in an amount equal to or greater than the total amount of hydroxyl groups in the fluoropolyether group-containing alcohol compound, so that all of the hydroxyl groups are reacted. Specifically, it is desirable to use 1 to 6 times, and particularly 1.2 to 4 times, the amount of (meth)acrylic acid halide in the reaction system relative to the amount of hydroxyl groups in the fluoropolyether group-containing alcohol compound. If the amount is too small, there is a high possibility that some of the fluoropolyether group-containing alcohol compound will remain without (meth)acrylic groups introduced.

[0066] In the ester production reaction in which a fluoropolyether group-containing alcohol compound is reacted with a (meth)acrylic acid halide, it is preferable to use an acid acceptor, and the fluoropolyether group-containing alcohol compound represented by the above formula (6), the (meth)acrylic acid halide, and the acid acceptor are mixed and stirred. Examples of the acid acceptor that can be used include triethylamine, pyridine, and urea. The amount of acid acceptor used is preferably about 0.9 to 3 times the number of moles of (meth)acrylic acid halide. If the amount is too small, a large amount of untrapped acid remains, whereas if the amount is too large, it becomes difficult to remove the excess acid acceptor.

[0067] In addition, during the reaction, the reaction may be carried out by diluting with an appropriate solvent as needed. Such a solvent can be used without any particular limitation as long as it does not react with the hydroxyl group of the fluoropolyether group-containing alcohol compound or the halogen atom of the (meth)acrylic acid halide. Specific examples include hydrocarbon solvents such as toluene, xylene, and isooctane; ether solvents such as tetrahydrofuran (THF), diisopropyl ether, and dibutyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, and cyclohexanone; fluorine-modified aromatic hydrocarbon solvents such as m-xylene hexafluoride (also known as hexafluorometa-xylene) and benzotrifluoride; and fluorine-modified ether solvents such as methyl perfluorobutyl ether. After the reaction, the solvent may be removed by a known method such as vacuum distillation. The amount of solvent used is not particularly limited, but is preferably 10 times or less the total mass of all the reaction components. If the amount of solvent used is too large, the reaction rate may decrease significantly.

[0068] The reaction is carried out at a temperature of 0 to 120°C, preferably 10 to 100°C, for 1 minute to 500 hours, preferably 10 minutes to 48 hours. If the reaction temperature is too low, the reaction rate may be too slow, whereas if the reaction temperature is too high, polymerization of the (meth)acrylic group may occur as a side reaction.

[0069] After the reaction is completed, the unreacted (meth)acrylic acid halide and the solvent are removed by distillation, adsorption, filtration, washing, or other methods, to obtain the fluoropolyether group-containing acrylic compound represented by the above formula (3).

[0070] The fluoropolyether group-containing acrylic compound thus obtained does not contain a volatile organic compound (volatile organic solvent). The fluoropolyether group-containing acrylic compound (A) may be used alone or in combination of two or more.

[0071] The second essential component in the fluorine-containing active energy ray-curable composition of the present invention is (B) an acrylic compound having a viscosity of 5,000 mPa s or less at 23°C and containing one or two acrylic groups or α-substituted acrylic groups per molecule, excluding component (A). The acrylic compound of component (B) may contain oxygen atoms and nitrogen atoms other than the acrylic structure, and specifically may contain an ether bond, a urethane bond, an isocyanate group, or a hydroxyl group.

[0072] Due to its solubility with component (A), component (B) has a viscosity at 23°C of 5,000 mPa·s or less, preferably 0.4 to 2,000 mPa·s. If the viscosity at 23°C exceeds 5,000 mPa·s, it becomes difficult to mix with component (A) and handling becomes poor. In the present invention, viscosity can be measured using a rotational viscometer (e.g., BL type, GH type, BS type, cone-plate type, rheometer, etc.) (the same applies hereinafter).

[0073] Of such components (B), preferred examples of compounds having one (meth)acrylic group in the molecule include those represented by the following general formula (7). CH2=C(R 5 )C(=O)OR 4 (7) (In the formula, R 4 R is a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a urethane bond, an ether bond, an isocyanate group, or a hydroxyl group, and some of the hydrogen atoms bonded to the carbon atoms may be substituted with fluorine atoms. 5 is a hydrogen atom, a methyl group, a fluorine atom, or a fluoroalkyl group having 1 to 6 carbon atoms.

[0074] In the above formula (7), R 4R is a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a urethane bond, an ether bond, an isocyanate group, or a hydroxyl group, and is preferably an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, preferably 7 to 10 carbon atoms, which may be branched or cyclic, and may contain an aliphatic unsaturated (double) bond, a urethane bond, an ether bond, an isocyanate group, or a hydroxyl group. 4 Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a hexyl group, a cyclohexyl group, an octyl group, a 2-ethyl-hexyl group, an isodecyl group, a tridecyl group, an isostearyl group, a phenyl group, a benzyl group, an isobornyl group, a dicyclopentanyl group, a dicyclopentenyl group, a furfuryl group, a tetrahydrofuryl group, a tetrahydropyranyl group, a 2-(2-ethoxyethoxy)ethyl group, -CH2CH2-OH, -CH2CH(CH3)-OH, -CH2CH2CH2-OH, -CH2CH2CH2CH2-OH, -CH2CH2CH2CH2CH2-OH, -CH2CH2CH2CH2CH2-OH, a 4-hydroxycyclohexyl group, and -CH2CH2-NCO. Also, R 4 may have some of the hydrogen atoms bonded to the carbon atoms substituted with fluorine atoms.

[0075] In addition, in the above formula (7), R 5 is a hydrogen atom, a methyl group, a fluorine atom, or a fluoroalkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group, a trifluoropropyl group, or a nonafluorobutyl group, and is particularly preferably a hydrogen atom, a methyl group, a fluorine atom, or a trifluoromethyl group.

[0076] Specific examples of such compounds represented by formula (7) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethyl-hexyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, isostearyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, benzyl (meth)acrylate, 2 -hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenoxyethyl (meth)acrylate, neopentyl glycol-(meth)acrylic acid-benzoic acid ester, and the like.

[0077] Also, in equation (7), R 4Specific examples of compounds in which some of the hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms include ethyl 2-fluoro(meth)acrylate, phenyl 2-fluoro(meth)acrylate, 3-fluoropropyl(meth)acrylate, 2,2-difluoroethyl(meth)acrylate, methyl 3,3-difluoro(meth)acrylate, 2-fluoroethyl(meth)acrylate, methyl 2-fluoro(meth)acrylate, 1H,1H-perfluorononyl(meth)acrylate, methyl 2,3,3-trifluoro(meth)acrylate, pentafluoro(meth)acrylate, Perfluorobenzyl (meth)acrylate, pentafluorophenyl (meth)acrylate, tert-butyl 2-fluoro(meth)acrylate, methyl 2-fluoro(meth)acrylate, hexafluoroisopropyl (meth)acrylate, methyl 3-(4-fluorophenyl)(meth)acrylate, 3-(trifluoromethyl)benzyl (meth)acrylate, 1H,1H-perfluorooctyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, heptafluoroisopropyl (meth)acrylate, 2-(perfluoro (2E)-3-(4-fluorophenyl)(meth)acrylate, 2,2,2-trichloroethyl-2-fluoro(meth)acrylate, 1H,1H-pentafluorobutyl-2-fluoro(meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 1H,1H-pentafluoropropyl (meth)acrylate, 2,2,2-trifluoroethyl-2-fluoro(meth)acrylate, methyl 3-(2,4-difluorophenyl)(meth)acrylate, ethyl (2E)-3-(4-fluorophenyl)(meth)acrylate, 2,2,2-trichloroethyl-2-fluoro(meth)acrylate, 1H,1H-pentafluorobutyl-2-fluoro(meth)acrylate, methyl 2-(trifluoro (E)-methyl 3-(2,5-difluorophenyl)(meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, tert-butyl 2-(trifluoromethyl)(meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, (E)-methyl 3-(2,5-difluorophenyl)(meth)acrylate, (E)-methyl 3-(3,5-difluorophenyl)(meth)acrylate, 1H,1H,7H-dodecafluorophenyl (meth)acrylate, 2,2,3,4,4,4-hexafluorobutyl (meth)acrylate, and the like.Commercially available products include, for example, those with the product names "CHEMINOX FAAC-4," "CHEMINOX FAAC-6," "CHEMINOX FAMAC-4," and "CHEMINOX FAMAC-6" (all manufactured by Unimatec Co., Ltd.), "Viscoat 3F," "Viscoat 4F," "Viscoat 8F," "Viscoat 8FM," and "Viscoat 13F" (all manufactured by Osaka Organic Chemical Industry Ltd.).

[0078] In addition, compounds that do not fall under formula (7), such as (meth)acrylic compounds commercially available under names such as methoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and nonylphenol EO adduct acrylate, which have a repeating unit structure of ethylene oxide, propylene oxide, tetramethylene oxide, lactone, or the like and have various alkoxy terminals, can also be used as long as they have a viscosity of 5,000 mPa s or less at 23°C.

[0079] Furthermore, among the components (B), preferred examples of compounds having two (meth)acrylic groups in the molecule include those represented by the following general formula (8). CH2=C(R 7 )C(=O)OR 6 -O(O=)C(R 7 )C=CH2(8) (In the formula, R 6 R is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain a urethane bond, an ether bond, an isocyanate group, or a hydroxyl group, and some of the hydrogen atoms bonded to the carbon atoms may be substituted with fluorine atoms. 7 are each independently a hydrogen atom, a methyl group, a fluorine atom or a fluoroalkyl group having 1 to 6 carbon atoms.

[0080] In the above formula (8), R 6R is a divalent hydrocarbon group having 1 to 20 carbon atoms which may contain a urethane bond, an ether bond, an isocyanate group, or a hydroxyl group, and is preferably an alkylene group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, or an aralkylene group having 7 to 20 carbon atoms, preferably 7 to 10 carbon atoms, which may be branched or cyclic and may contain an aliphatic unsaturated (double) bond, a urethane bond, an ether bond, an isocyanate group, or a hydroxyl group. 6 Specific examples of the alkyl group include a methylene group, an ethylene group, a propylene group (trimethylene group, methylethylene group), a butylene group (tetramethylene group, methylpropylene group), a hexylene group (hexamethylene group), a cyclohexylene group, an octamethylene group, a nonamethylene group, a decamethylene group, -CH2CH2-O-CH2CH2-, -C3H6-O-C3H6-, a phenylene group, a dicyclopentanylene group, a dicyclopentenylene group, a furfurylene group, a tetrahydrofulrylene group, and a tetrahydropyranylene group. Also, R 6 may have some of the hydrogen atoms bonded to the carbon atoms substituted with fluorine atoms.

[0081] Also, R 7 are each independently a hydrogen atom, a methyl group, a fluorine atom, a fluoroalkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group, a trifluoropropyl group, or a nonafluorobutyl group, and are particularly preferably a hydrogen atom, a methyl group, a fluorine atom, or a trifluoromethyl group.

[0082] More specific examples of such compounds represented by formula (8) include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, nonanediol di(meth)acrylate, and 10-decanediol di(meth)acrylate.

[0083] Component (B) preferably contains a fluoroalkyl group and one or two acrylic groups or α-substituted acrylic groups. When component (B) contains a fluoroalkyl group, it has good compatibility with the fluoropolyether group-containing acrylic compound of component (A), improving the transparency of the cured product.

[0084] Specific examples of such compounds include those represented by the following formula: [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0085] Furthermore, it is particularly preferred that the component (B) contains one or more perfluoroalkyl groups having 1 to 8 carbon atoms and one or two acrylic groups or α-substituted acrylic groups.

[0086] Specific examples of such compounds include those represented by the following formula: [ka]

[0087] Component (B) may be a single compound or a mixture of multiple compounds that meet the above definition, and in the case of a mixture, the total content of the compounds that fall under component (B) can be calculated as the content of component (B). Compounds that fall under component (B) can be synthesized by known methods as needed, but various compounds are commercially available from reagent manufacturers, etc., and these can also be used as they are.

[0088] The content of component (B) is 0.1 to 300 parts by mass, and preferably 1 to 100 parts by mass, per 100 parts by mass of component (A). If the content is less than 0.1 part by mass, it becomes difficult to adjust the viscosity of the fluorine-containing active energy ray-curable composition to a range that exhibits excellent handleability, while if the content exceeds 300 parts by mass, it becomes difficult for the fluorine-containing active energy ray-curable composition to exhibit a low refractive index.

[0089] The third essential component in the fluorine-containing active energy ray-curable composition of the present invention is (C) a photopolymerization initiator. The photopolymerization initiator (C), component, is not particularly limited as long as it can cure an acrylic compound by irradiation with active energy rays. Examples thereof include acetophenone, benzophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanon-1-one, and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one. Examples of such initiators include (dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 1,2-octanedione-1-[4-(phenylthio)-2-(o-benzoyloxime)], ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(o-acetyloxime), and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one. These initiators may be used alone or in combination of two or more. Among these, alkylphenone-based photopolymerization initiators and acylphosphine oxide-based photopolymerization initiators are preferred from the viewpoint of excellent photocurability.

[0090] Furthermore, it is more preferable that the photopolymerization initiator of component (C) does not contain a fluorine atom in its structure. Photopolymerization initiators that do not contain a fluorine atom in their structure are easy to obtain, and by using various commercially available photopolymerization initiators, the absorption wavelength and curing characteristics of the fluorine-containing active energy ray-curable composition can be controlled.

[0091] The content of component (C) is 0.01 to 20 parts by mass, and preferably 0.1 to 6 parts by mass, per 100 parts by mass of component (A). If the amount added is less than this, curability will decrease, and if it is more than this, the impact on physical properties after curing will be significant.

[0092] It is particularly preferred that the fluorine-containing active energy ray-curable composition of the present invention does not contain a volatile organic compound having no group reactive with an acrylic group (particularly a non-reactive volatile organic compound (or volatile organic solvent) having no (meth)acrylic group in the molecule) (i.e., a solvent-free fluorine-containing active energy ray-curable composition). When the composition does not contain a volatile organic compound having no group reactive with an acrylic group, it becomes unnecessary to remove the solvent by heating before forming a cured product, and therefore the process can be made less energy-intensive.

[0093] The fluorine-containing active energy ray-curable composition of the present invention may also contain other active energy ray-reactive compounds other than acrylic groups, such as thiol compounds and maleimide compounds, polymerization inhibitors, antistatic agents, antifoaming agents, viscosity modifiers, light resistance stabilizers, heat resistance stabilizers, antioxidants, surfactants, colorants, and polymer or inorganic fillers, etc. These are not particularly limited in structure, and known compounds can be used as long as they do not impair the object of the present invention.

[0094] The fluorine-containing active energy ray-curable composition of the present invention can be produced by a conventionally known method. For example, it can be produced by blending predetermined amounts of components (A) to (C) and, if necessary, other components, and mixing them using a mixing means such as a mixer at a temperature of preferably 10°C to 70°C for preferably 0.1 to 5 hours. It is also preferable to produce it in a light-shielded environment.

[0095] The viscosity of the fluorine-containing active energy ray-curable composition of the present invention at 23°C is 10 to 100,000 mPa·s, preferably 10 to 70,000 mPa·s, and more preferably 10 to 40,000 mPa·s. Such a viscosity results in a curable composition with good handleability (workability). Here, handleability (workability) means, for example, that when handling the fluorine-containing active energy ray-curable composition of the present invention, phenomena such as dripping and offset due to low viscosity during coating and other operations are unlikely to occur, or that phenomena such as poor segregation and poor leveling due to high viscosity are unlikely to occur. In the present invention, in order to achieve a viscosity at 23°C within the above range, it is simple and preferable to appropriately adjust the proportion of the relatively high-viscosity component (A) and the relatively low-viscosity component (B).

[0096] The refractive index of the fluorine-containing active energy ray-curable composition of the present invention at a temperature of 25°C and a wavelength of 589 nm is preferably 1.390 or less, more preferably 1.380 or less, and even more preferably 1.370 or less. When the composition has such a refractive index, it can form a cured product with a low refractive index that is useful for optical component applications. The refractive index can be measured using a refractometer such as an Abbe refractometer. In the present invention, in order to achieve a refractive index of 1.390 or less at a temperature of 25°C and a wavelength of 589 nm, the fluoropolyether group-containing acrylic compound of component (A) must have a divalent perfluoropolyether group composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and having a number average molecular weight of 500 to 40,000.

[0097] The fluorine-containing active energy ray-curable composition of the present invention obtained as described above has an acrylic group or an α-substituted acrylic group as the active energy ray-curable group, and therefore can be cured by active energy rays such as ultraviolet light or an electron beam, and has a perfluoropolyether group as a group having a low refractive index and water vapor resistance, and therefore can form a transparent cured product having a low refractive index and excellent water vapor resistance.

[0098] Furthermore, the present invention provides a cured product of the above-mentioned fluorine-containing active energy ray-curable composition of the present invention. This cured product can be obtained by irradiating the above-mentioned fluorine-containing active energy ray-curable composition of the present invention with light such as electron beams, ultraviolet light, or visible light. The light source is not particularly limited, and examples thereof include mercury lamps, black light lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, LED lamps, fluorescent lamps, sunlight, and electron beam irradiation devices. As the light, ultraviolet light is particularly preferred, and as the ultraviolet light source, mercury lamps, metal halide lamps, and LED lamps are preferred. From the viewpoint of the properties of the cured product, the exposure dose of light irradiation is 10 to 10,000 mJ / cm. 2 , especially 100 to 4,000 mJ / cm 2 If the amount is too small, uncured components may remain, whereas if the amount is too large, the cured product may deteriorate.

[0099] To prevent curing inhibition by oxygen, the irradiation atmosphere during UV irradiation may be replaced with an oxygen-free inert gas such as nitrogen, carbon dioxide, or argon, or the surface of the cured product may be covered with a UV-transmitting protective layer that has mold-releasability and be irradiated with UV light from above, or if the substrate is UV-transmitting, the surface of the cured product may be covered with a UV-releasable protective layer and then be irradiated with UV light from the substrate side. Furthermore, to effectively level the cured product or polymerize the (meth)acrylic groups in the cured product, the cured product and substrate may be heated by any method, such as infrared radiation or a hot air drying oven, before and during UV irradiation.

[0100] As described above, the cured product obtained by curing the fluorine-containing active energy ray-curable composition of the present invention exhibits a low refractive index and excellent water vapor resistance.

[0101] The refractive index of the cured product at a temperature of 25°C and a wavelength of 589 nm is preferably 1.400 or less, more preferably 1.390 or less, and even more preferably 1.380 or less. When the cured product has such a refractive index, it is particularly useful for optical components. In the present invention, to achieve a refractive index of 1.400 or less under the above conditions, the fluoropolyether group-containing acrylic compound must have a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000 and composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom.

[0102] Furthermore, the change in hardness of the cured product after heating for 12 hours under conditions of 95°C and 100% RH is preferably within ±10 points of the initial value, more preferably within ±7 points of the initial value. If the change is within ±10 points of the initial value, the cured product has excellent steam resistance. Specifically, the hardness can be measured according to JIS K6253. In the present invention, in order to keep the change in hardness within the above range, it is necessary to select the divalent perfluoropolyether group Rf contained in component (A). 1 or Rf 2 is preferably a structure represented by the following formula: [ka] (In the formula, c, d, e, f, g, h, i, and d+e+f+g+h+i are the same as above, and each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.)

[0103] Furthermore, the present invention provides an article having, as all or at least a part of its constitution, a cured product of the above-mentioned fluorine-containing active energy ray-curable composition of the present invention. As described above, by using the fluorine-containing active energy ray-curable composition of the present invention, it is possible to impart a low refractive index and water vapor resistance to the article.

[0104] The fluorine-containing active energy ray-curable composition of the present invention can be suitably used for optical parts, specifically as an antireflection agent, a coating agent for optical fibers, a lens, etc.

[0105] Here, the method for applying the fluorine-containing active energy ray-curable composition of the present invention is not particularly limited, and for example, known application methods such as knife coating, roll coating, gravure coating, flow coating, dip coating, spray coating, spin coating, bar coating, and screen printing can be used.

[0106] After coating, the coating film is irradiated with active energy rays to cure it. Here, the active energy rays can be any light such as electron beams, ultraviolet light, or visible light, and the light source is not particularly limited, but examples include mercury lamps, black light lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, LED lamps, fluorescent lamps, sunlight, and electron beam irradiation devices. As light, ultraviolet light is particularly preferred, and as ultraviolet light sources, mercury lamps, metal halide lamps, and LED lamps are preferred. The exposure dose of light irradiation is 10 to 10,000 mJ / cm from the viewpoint of the properties of the cured product. 2 , especially 100 to 4,000 mJ / cm 2 If the amount is too small, uncured components may remain, whereas if the amount is too large, the cured product may deteriorate.

[0107] To prevent curing inhibition by oxygen, the irradiation atmosphere during UV irradiation may be replaced with an oxygen-free inert gas such as nitrogen, carbon dioxide, or argon, or the surface of the cured product may be covered with a UV-transmitting protective layer that has mold-releasability and be irradiated with UV light from above, or if the substrate is UV-transmitting, the surface of the cured product may be covered with a UV-releasable protective layer and then be irradiated with UV light from the substrate side. Furthermore, to effectively level the cured product or polymerize the (meth)acrylic groups in the cured product, the cured product and substrate may be heated by any method, such as infrared radiation or a hot air drying oven, before and during UV irradiation. [Example]

[0108] The present invention will be specifically explained below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. In the following examples, the number average molecular weight of the perfluoropolyether group is 19 The viscosity of component (B) was measured at 23°C in accordance with JIS K7117.

[0109] (A) Synthesis of fluoropolyether group-containing acrylic compound [Synthesis Example 1] Synthesis of fluoropolyether group-containing acrylic compound (A-1) In a dry nitrogen atmosphere, a reaction vessel was charged with a compound having the following average structure: [ka] (Rf A1 Number average molecular weight: approx. 4,400 100 g (0.025 mol) of compound (I) represented by the following formula [ka] 12.2 g (0.20 mol) of compound (i) represented by the formula (I) and 100 g of m-xylene hexafluoride were charged and stirred at 60°C for 3 hours under a dry nitrogen atmosphere. IR analysis of the reaction solution confirmed the disappearance of the band derived from the -C(=O)F bond. The resulting reaction solution was washed with water and then distilled under reduced pressure to obtain 92.3 g of fluoropolyether group-containing alcohol compound (II) represented by the following structural formula. [ka] (Rf A1 Number average molecular weight: approx. 4,400

[0110] In a dry air atmosphere, 50.0 g (hydroxyl group amount 0.024 mol) of the fluoropolyether group-containing alcohol compound (II) obtained by the above method was mixed with 50.0 g of THF and 3.6 g (0.024 mol) of methacryloyloxyethyl isocyanate in a reaction vessel, and the mixture was heated to 50°C. 0.15 g of bismuth carboxylate catalyst (XK-640 manufactured by Kusumoto Chemicals) was added, and the mixture was stirred at 50°C for 24 hours. After heating, the mixture was evaporated under reduced pressure to obtain 46.3 g of a highly viscous liquid substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-1) represented by the following formula. [ka] (Rf A1 Number average molecular weight: approx. 4,400

[0111] [Synthesis Example 2] Synthesis of fluoropolyether group-containing acrylic compound (A-2) In a dry nitrogen atmosphere, a reaction vessel was charged with a compound having the following average structure: [ka] (Rf A2 Number average molecular weight: approx. 5,800 100 g (0.017 mol) of compound (III) represented by the following formula [ka] 8.5 g (0.14 mol) of compound (i) represented by the formula (I) and 100 g of m-xylene hexafluoride were charged and stirred at 65°C for 8 hours under a dry nitrogen atmosphere. IR analysis of the reaction solution confirmed the disappearance of the band derived from the -C(=O)F bond. The resulting reaction solution was washed with water and then distilled under reduced pressure to obtain 94.4 g of fluoropolyether group-containing alcohol compound (IV) represented by the following structural formula. [ka] (Rf A2 Number average molecular weight: approx. 5,800

[0112] In a dry air atmosphere, 50.0 g (hydroxyl group amount 0.017 mol) of the fluoropolyether group-containing alcohol compound (IV) obtained by the above method was mixed with 50.0 g of m-xylene hexafluoride, 3.6 g (0.034 mol) of methacrylic acid chloride, and 4.4 g (0.043 mol) of triethylamine in a reaction vessel, and the mixture was stirred for 24 hours at 50° C. After heating, the mixture was washed with water and then distilled under reduced pressure to obtain 39.9 g of a highly viscous liquid substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-2) represented by the following formula. [ka] (Rf A2 Number average molecular weight: approx. 5,800

[0113] [Synthesis Example 3] Synthesis of fluoropolyether group-containing acrylic compound (A-3) In a dry air atmosphere, 50.0 g (hydroxyl group amount 0.017 mol) of fluoropolyether group-containing alcohol compound (IV) obtained in the same manner as in Synthesis Example 2 was mixed with 50.0 g of THF and 2.6 g (0.017 mol) of methacryloyloxyethyl isocyanate in a reaction vessel, and the mixture was heated to 50° C. 0.15 g of bismuth carboxylate catalyst (XK-640 manufactured by Kusumoto Chemicals) was added thereto, and the mixture was stirred at 50° C. for 24 hours. After heating, the mixture was evaporated under reduced pressure to obtain 48.3 g of a highly viscous liquid substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-3) represented by the following formula. [ka] (Rf A2 Number average molecular weight: approx. 5,800

[0114] [Synthesis Example 4] Synthesis of fluoropolyether group-containing acrylic compound (A-4) In a dry air atmosphere, 50.0 g (hydroxyl group amount 0.017 mol) of fluoropolyether group-containing alcohol compound (IV) obtained in the same manner as in Synthesis Example 2 was mixed with 50.0 g of THF and 4.1 g (0.017 mol) of 1,1-(bisacryloyloxymethyl)ethyl isocyanate in a reaction vessel, and the mixture was heated to 50°C. 0.15 g of bismuth carboxylate catalyst (XK-640 manufactured by Kusumoto Chemicals) was added, and the mixture was stirred at 50°C for 24 hours. After heating, the mixture was evaporated under reduced pressure to obtain 37.3 g of a highly viscous liquid substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-4) represented by the following formula. [ka] (Rf A2 Number average molecular weight: approx. 5,800

[0115] [Synthesis Example 5] Synthesis of fluoropolyether group-containing acrylic compound (A-5) In a dry nitrogen atmosphere, a reaction vessel was charged with a compound having the following average structure: [ka] (Rf A3 Number average molecular weight: approx. 15,300 100 g (0.0063 mol) of compound (V) represented by the following formula [ka] 3.1 g (0.05 mol) of compound (i) represented by the formula (I) and 100 g of m-xylene hexafluoride were charged and stirred at 65°C for 8 hours under a dry nitrogen atmosphere. IR analysis of the reaction solution confirmed the disappearance of the band derived from the -C(=O)F bond. The resulting reaction solution was washed with water and then distilled under reduced pressure to obtain 73.2 g of fluoropolyether group-containing alcohol compound (VI) represented by the following structural formula. [ka] (Rf A3 Number average molecular weight: approx. 15,300

[0116] In a dry air atmosphere, 50.0 g of the fluoropolyether group-containing alcohol compound (VI) (hydroxyl group amount: 0.0063 mol) obtained by the above method was mixed with 50.0 g of THF and 0.98 g (0.0063 mol) of methacryloyloxyethyl isocyanate in a reaction vessel, and the mixture was heated to 50°C. 0.15 g of a bismuth carboxylate catalyst (XK-640 manufactured by Kusumoto Chemicals) was added, and the mixture was stirred at 50°C for 24 hours. After heating, the mixture was evaporated under reduced pressure to obtain 32.8 g of a highly viscous liquid substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-5) represented by the following formula. [ka] (Rf A3 Number average molecular weight: approx. 15,300

[0117] [Synthesis Example 6] Synthesis of fluoropolyether group-containing acrylic compound (A-6) In a dry nitrogen atmosphere, a reaction vessel was charged with a compound having the following average structure: [ka] (Rf A2 Number average molecular weight: approx. 5,800 100 g (0.017 mol) of compound (III) represented by the following formula [ka] 12.8 g (0.14 mol) of compound (ii) represented by the formula (II) and 100 g of m-xylene hexafluoride were charged and stirred at 65°C for 8 hours under a dry nitrogen atmosphere. IR analysis of the reaction solution confirmed the disappearance of the band derived from the -C(=O)F bond. The resulting reaction solution was washed with water and then distilled under reduced pressure to obtain 88.7 g of fluoropolyether group-containing alcohol compound (VII) represented by the following structural formula. [ka] (Rf A2 Number average molecular weight: approx. 5,800

[0118] In a dry air atmosphere, 50.0 g (hydroxyl group amount 0.033 mol) of the fluoropolyether group-containing alcohol compound (VII) obtained by the above method was mixed with 50.0 g of THF and 5.1 g (0.033 mol) of methacryloyloxyethyl isocyanate in a reaction vessel, and the mixture was heated to 50° C. 0.15 g of bismuth carboxylate catalyst (XK-640 manufactured by Kusumoto Chemicals) was added thereto, and the mixture was stirred at 50° C. for 24 hours. After heating, the mixture was evaporated under reduced pressure to obtain 36.6 g of a liquid highly viscous substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-6) represented by the following formula. [ka] (Rf A2 Number average molecular weight: approx. 5,800

[0119] [Synthesis Example 7] Synthesis of fluoropolyether group-containing acrylic compound (A-7) In a dry nitrogen atmosphere, a reaction vessel was charged with a compound having the following average structure: [ka] (However, Rf A4 The number average molecular weight of is about 3,600, and the Rf A4 The sequence of each repeat unit enclosed in brackets is random.) 100 g (0.027 mol) of compound (VIII) represented by the following formula [ka] 13.4 g (0.22 mol) of compound (i) represented by the formula (I) and 100 g of m-xylene hexafluoride were charged and stirred at 65°C for 8 hours under a dry nitrogen atmosphere. IR analysis of the reaction solution confirmed the disappearance of the band derived from the -C(=O)F bond. The resulting reaction solution was washed with water and then distilled under reduced pressure to obtain 88.3 g of fluoropolyether group-containing alcohol compound (IX) represented by the following structural formula. [ka] (However, Rf A4 The number average molecular weight of is about 3,600, and the Rf A4 The sequence of each repeat unit enclosed in brackets is random.)

[0120] In a dry air atmosphere, 50.0 g (hydroxyl group amount 0.026 mol) of the fluoropolyether group-containing alcohol compound (IX) obtained by the above method was mixed with 50.0 g of THF and 4.0 g (0.026 mol) of methacryloyloxyethyl isocyanate in a reaction vessel, and the mixture was heated to 50°C. 0.15 g of bismuth carboxylate catalyst (XK-640 manufactured by Kusumoto Chemicals) was added, and the mixture was stirred at 50°C for 24 hours. After heating, the mixture was evaporated under reduced pressure to obtain 32.8 g of a highly viscous liquid substance. 1 From the results of H-NMR and IR, it was confirmed that the compound was a fluoropolyether group-containing acrylic compound (A-7) represented by the following formula. [ka] (However, Rf A4 The number average molecular weight of is about 3,600, and the Rf A4 The sequence of each repeat unit enclosed in brackets is random.)

[0121] The fluoropolyether group-containing acrylic compounds (A-1) to (A-7) obtained in the above Synthesis Examples 1 to 7 do not contain any volatile organic compounds.

[0122] Preparation of fluorine-containing active energy ray-curable composition [Examples 1 to 15, Comparative Example 1] Fluorine-containing active energy ray-curable compositions (F-1) to (F-16) were prepared using the fluoropolyether group-containing acrylic compounds (A-1) to (A-7) obtained in Synthesis Examples 1 to 7 above, the following acrylic compounds (B-1) to (B-5), and the following photopolymerization initiators (C-1) and (C-2) in the proportions shown in Table 1 below.

[0123] (B-1) 2-(perfluorobutyl)ethyl methacrylate (viscosity: 2.2 mPa·s) (B-2) 2-Hydroxyethyl methacrylate (viscosity: 6.1 mPa·s) (B-3) 1,6-Hexanediol diacrylate (viscosity: 6.5 mPa·s) (B-4) 2-(perfluorohexyl)ethyl methacrylate (viscosity: 3.3 mPa·s) (B-5) 1H,1H,5H-Octafluoropentyl methacrylate (viscosity: 4.1 mPa·s)

[0124] (C-1) 2-Hydroxy-2-methylpropiophenone (C-2) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

[0125] Composition ratio [Table 1]

[0126] Evaluation of the appearance of the composition The appearance of each of the fluorine-containing active energy ray-curable compositions of the Examples and Comparative Examples was visually observed and evaluated according to the following criteria. The results are shown in Table 2. ○ (Good): Uniform. × (bad): Uneven.

[0127] Evaluation of the viscosity of the composition The viscosity of each of the fluorine-containing active energy ray-curable compositions of Examples and Comparative Examples was measured in accordance with JIS K7117-1, Z8803 at 23° C. The results are shown in Table 2.

[0128] Evaluation of the refractive index of the composition The refractive index of each of the fluorine-containing active energy ray-curable compositions of Examples and Comparative Examples was measured using an Abbe refractometer (DR-A1 manufactured by Atago Co., Ltd.) at a temperature of 25° C. and a wavelength of 589 nm. The results are shown in Table 2.

[0129] [Table 2]

[0130] Coating and curing Each of the fluorine-containing active energy ray-curable compositions of Examples and Comparative Examples was knife-coated onto a glass sheet (spacer thickness: 2.0 mm). After vacuum degassing, the composition was irradiated with a conveyor-type UV-LED irradiator (manufactured by Eye Graphics, wavelength: 365 nm) in a nitrogen atmosphere at a peak intensity of 490 mW / cm. 2 , cumulative irradiation dose 1,000mJ / cm 2 The composition was cured by irradiating it with ultraviolet light twice, once from the coated surface and once from the glass surface, to obtain a cured product having a thickness of about 2 mm.

[0131] Evaluation of refractive index of cured material The refractive index of the cured products of the examples and comparative examples prepared above was measured using an Abbe refractometer (DR-A1 manufactured by Atago Co., Ltd.) at a temperature of 25° C. and a wavelength of 589 nm. The results are shown in Table 3.

[0132] Evaluation of hardness, tensile strength, and elongation at break of cured product The hardness, tensile strength, and elongation at break of the cured products prepared in the Examples and Comparative Examples were measured in accordance with JIS K6250, 6251, and 6253. The hardness was measured using a Durometer A hardness tester. The results are shown in Table 3.

[0133] Steam resistance test of cured product The cured products of the examples and comparative examples prepared above were heated in an air atmosphere at 95°C and 100% RH for 12 hours. After the test, the hardness, tensile strength, and elongation at break of the cured products were measured. The results are shown in Table 3.

[0134] [Table 3]

[0135] Examples 1 to 15 were produced using fluorine-containing active energy ray-curable compositions (F-1) to (F-15) prepared by blending specific proportions of the fluoropolyether group-containing acrylic compounds (A-1) to (A-7) of the present invention, which are the component (A), the acrylic compound (B) containing one or two acrylic groups or α-substituted acrylic groups per molecule, and the photopolymerization initiator (C). These compositions produced cured products exhibited low refractive indices and showed small changes in hardness, tensile strength, and elongation at break after a water vapor resistance test, demonstrating excellent water vapor resistance. On the other hand, in Comparative Example 1, a fluorine-containing active energy ray-curable composition (F-16) was prepared by blending only the fluoropolyether group-containing acrylic compound (A) and the photopolymerization initiator (C) without blending the acrylic compound (B) containing one or two acrylic groups or α-substituted acrylic groups per molecule. In Comparative Example 1, the viscosity of the composition was extremely high and the handling properties were poor.

Claims

1. (A) a fluoropolyether group-containing acrylic compound represented by the following general formula (1): V 1 -Rf 1 -Z-Y(X) b (1) (wherein, Rf 1 is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000, which is composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and has perfluoroalkylene groups having 2 to 6 carbon atoms at both ends. Z is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000, which is represented by the following formula: 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 【Transformation 5】 (In the formula, R is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms. Y and X are the same as Y and X described below. In the formula, * indicates Rf 1 is a bond bonding to , and ** is a bond bonding to Y. Y is a (b+1)-valent organic group having 1 to 20 carbon atoms. X is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains at least one acrylic group or α-substituted acrylic group on average per molecule. V 1 is a hydrogen atom, a fluorine atom, or -Z-Y(X) b and b is an integer of 1 to 10. (B) an acrylic compound (excluding component (A)) having a viscosity of 5,000 mPa·s or less at 23°C, containing a fluoroalkyl group and one or two acrylic groups or α-substituted acrylic groups in one molecule, and (C) Photopolymerization initiator as an essential component, and has a viscosity at 23°C in the range of 10 to 100,000 mPa·s, and a refractive index at a temperature of 25°C and a wavelength of 589 nm of 1.390 or less.

2. 2. The fluorine-containing active energy ray-curable composition according to claim 1, wherein the amount of the component (B) is 0.1 to 300 parts by mass and the amount of the component (C) is 0.01 to 20 parts by mass, relative to 100 parts by mass of the component (A).

3. 2. The fluorine-containing active energy ray-curable composition according to claim 1, which does not contain a non-fluorinated acrylic compound.

4. 2. The fluorine-containing active energy ray-curable composition according to claim 1, which does not contain a volatile organic compound having no group reactive with an acrylic group.

5. 2. The fluorine-containing active energy ray-curable composition according to claim 1, which is a solvent-free composition.

6. In general formula (1), Rf 1 is expressed as follows: 【Transformation 6】 (In the formula, c is independently an integer of 2 to 6 for each unit; d, e, f, g, h, and i are each integers of 0 to 200, and d+e+f+g+h+i=4 to 200. Each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.) 2. The fluorine-containing active energy ray-curable composition according to claim 1, wherein the divalent perfluoropolyether group is represented by the formula:

7. 2. The fluorine-containing active energy ray-curable composition according to claim 1, wherein component (A) is a fluoropolyether group-containing acrylic compound represented by the following general formula (2): V 2 -Rf 2 -C(=O)-NR 1 a [Y 2 (X 2 ) b’ ] 2-a (2) (wherein, Rf 2 is a divalent perfluoropolyether group having a number average molecular weight of 500 to 40,000, which is composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and has perfluoroalkylene groups having 2 to 6 carbon atoms at both ends. 2 are independently (b'+1)-valent organic groups having 1 to 20 carbon atoms. 2 R is independently a monovalent organic group containing an acrylic group or an α-substituted acrylic group, and contains at least one acrylic group or α-substituted acrylic group on average per molecule. 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms. 2 is a hydrogen atom, a fluorine atom, or —C(═O)—NR 1 a [Y 2 (X 2 ) b’ ] 2-a a is 0 or 1, and b' is an integer from 1 to 10.

8. In general formula (2), Rf 2 is expressed as follows: 【Transformation 7】 (In the formula, c is independently an integer of 2 to 6 for each unit; d, e, f, g, h, and i are each integers of 0 to 200, and d+e+f+g+h+i=4 to 200. Each of these units may be linear or branched, and each repeating unit shown in parentheses with d, e, f, g, h, and i may be bonded randomly.) 8. The fluorine-containing active energy ray-curable composition according to claim 7, wherein the divalent perfluoropolyether group is represented by the following formula:

9. In general formula (2), Rf 2 is the following structural formula -CF 2 CF 2 O-(CF 2 CF 2 CF 2 O) q -CF 2 CF 2 - (In the formula, q is an integer of 4 to 200.) 【Transformation 8】 (wherein r is an integer from 1 to 6, C r F 2r O may be linear or branched, s is an integer of 0 to 6, t and u are each an integer of 1 to 200, t+u is an integer of 2 to 200, and s+t+u is an integer of 4 to 200. v is an integer of 5 to 200.

8. The fluorine-containing active energy ray-curable composition according to claim 7, wherein the divalent perfluoropolyether group is selected from the group consisting of:

10. In general formula (2), R 1 The fluorine-containing active energy ray-curable composition according to claim 7, wherein is a hydrogen atom and a is 1.

11. In the general formula (2), Y 2 8. The fluorine-containing active energy ray-curable composition according to claim 7, wherein is a hydrocarbon group having 1 to 20 carbon atoms and a valence of (b'+1).

12. In the general formula (2), Y 2 8. The fluorine-containing active energy ray-curable composition according to claim 7, wherein: 【Chemistry 9】 (In the formula, * is a bond bonded to N, ** is X 2 is the bond that bonds with

13. In general formula (2), X 2 is the following structural formula 【Chemistry 10】 (In the formula, R 2 are independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; W is a single bond, or a divalent or trivalent hydrocarbon group which may contain one or more bonds selected from an ether bond, an ester bond, and a urethane bond; and n is 1 or 2.

8. The fluorine-containing active energy ray-curable composition according to claim 7, which is represented by the formula:

14. 2. The fluorine-containing active energy ray-curable composition according to claim 1, wherein the component (B) is an acrylic compound represented by any one of the following formulas: 【Chemistry 11】 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 【Chemistry 16】 【Chemistry 17】

15. The fluorine-containing active energy ray-curable composition according to claim 1, wherein component (B) contains one or more perfluoroalkyl groups having 1 to 8 carbon atoms and one or two acrylic groups or α-substituted acrylic groups.

16. 2. The fluorine-containing active energy ray-curable composition according to claim 1, wherein the component (B) is an acrylic compound represented by any one of the following formulas: [Chemistry 18] 【Chemistry 19】 【Chemistry 20】

17. 2. The fluorine-containing active energy ray-curable composition according to claim 1, wherein the photopolymerization initiator (C) does not contain a fluorine atom in its structure.

18. 2. The fluorine-containing active energy ray-curable composition according to claim 1, which is used as an antireflection agent or a coating agent for optical fibers.

19. A cured product obtained by curing the fluorine-containing active energy ray-curable composition according to any one of claims 1 to 18.

20. 20. The cured product according to claim 19, which has a refractive index of 1.400 or less at a temperature of 25°C and a wavelength of 589 nm.

21. 20. The cured product according to claim 19, wherein the change in hardness after heating for 12 hours under conditions of 95°C and 100% RH is within ±10 points of the initial value.

22. 20. An article comprising the cured product according to claim 19 as the entire or at least a part of its configuration.

23. 23. The article of claim 22, which is an optical component.

24. 23. The article according to claim 22, which is one of a lens, an anti-reflective coating, and an optical fiber.

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