Hard-coated film, method for producing the same, and display including the hard-coated film

Abstract

To provide a flexible hard coat film which is excellent in bending restorability and a low phase difference and has both hardness and flexibility, and also to provide a method for manufacturing the hard coat film and a display including the hard coat film.SOLUTION: Provided is a hard coat film comprising a transparent resin film layer and a hard coat layer, where the hard coat film has, on at least one surface of the transparent resin film with a thickness of 20-80 μm, a hard coat layer with a thickness of 3-49 μm which is a cured product of a composition of a condensate containing a silane compound having an alicyclic epoxy group in the molecule, has a front phase difference of 0-20 nm, and has a bending restoration angle of 70-180° as measured by bending the hard coat film with a radius of 3 mm for 24 hours in an environment of 60°C and 90% RH and then removing a load therefrom.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hard coat film and a method for producing the same, and also to a display including the hard coat film. [Background technology]

[0002] In recent years, there has been a demand for more flexible displays, and studies are being conducted to replace the glass materials that have been used for display cover windows, substrates, etc. with plastic film materials that have excellent flexibility. Among such flexible displays, the cover windows and substrates used in foldable displays and rollable displays are required to have transparency, hardness, and bending resistance. In particular, flexible displays such as foldable displays that are kept folded when not in use and rollable displays that are kept rolled up when not in use are often used in a shape that is close to flat when in use, and therefore, bending recovery, which is the property that allows deformation when kept in a folded or rolled up state to be resolved when returned to a flat state, is highly required.

[0003] As a glass substitute material for cover windows and substrates, there is a hard coat film in which a hard coat layer made of a cured composition based on a siloxane compound containing an alicyclic epoxy group is laminated onto an unstretched transparent polyimide film (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-70800 Summary of the Invention [Problem to be solved by the invention]

[0005] Hard coat layers using siloxane compounds have relatively little shrinkage during UV curing, and are less likely to curl or crack when forming a thick hard coat layer. However, transparent polyimide films have a large retardation even when not stretched, which can cause a large retardation in the hard coat film. When used as a display component, this can lead to problems such as difficulty in viewing images viewed through a polarizer, such as polarized sunglasses. Therefore, an object of the present invention is to provide a flexible hard-coated film that has excellent folding recovery and low retardation, and combines hardness and flexibility, as well as a method for producing the hard-coated film and a display including the hard-coated film. [Means for solving the problem]

[0006] In light of the above, the present inventors have conducted extensive research and have found that a hard coat layer formed of a cured product of a condensate composition containing a silane compound having an alicyclic epoxy group in its molecule has a previously unknown effect of significantly improving fold recovery. This finding suggests that forming a hard coat layer formed of a cured product of a condensate composition containing a silane compound having an alicyclic epoxy group in its molecule on a transparent resin film layer significantly improves fold recovery, resulting in a flexible hard coat film that is excellent in fold recovery and low retardation, and combines hardness and flexibility. The present invention is described below.

[0007] 1) A hard coat film having a transparent resin film layer and a hard coat layer, At least one surface of a transparent resin film layer having a thickness of 20 to 80 μm, a hard coat layer having a thickness of 3 to 49 μm, which is a cured product of a condensation product composition containing a silane compound having an alicyclic epoxy group in the molecule and represented by the following general formula (1), The front phase difference is 0 to 20 nm. A hard coat film characterized in that the recovery angle after bending is 70 to 180° when measured after being bent at a radius of 3 mm in an environment of 60°C and 90% RH for 24 hours and then the load is removed. (In the formula (1), R 1 is a group containing an alicyclic epoxy group, and R 2 is a hydrogen atom or an alkyl group, and R 3 is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and x is an integer of 1 to 3. [ka]

[0008] 2) The hard coat film according to 1), wherein the ratio of the folding recovery angle of the hard coat film after forming the hard coat layer on the transparent resin film layer to the folding recovery angle of the transparent resin film layer alone is 1.20 or more.

[0009] 3) A hard coat film having a hard coat layer which is a cured product of a condensation product composition containing a silane compound represented by general formula (2) in addition to a silane compound having an alicyclic epoxy group in the molecule, The hard coat film according to 1) or 2), characterized in that the ratio of [structural unit represented by general formula (1)] / ([structural unit represented by general formula (1)]+[structural unit represented by general formula (2)]) of the condensate is 0.5 or more and 1.0 or less. (However, the silane compound represented by the general formula (2) is a silane compound different from the silane compound represented by the general formula (1), and in the general formula (2), R 4 does not contain an alicyclic epoxy group, and is a group containing a substituted or unsubstituted double bond, a group containing a substituted or unsubstituted cycloalkyl group, a group containing a substituted or unsubstituted aromatic ring, a substituted or unsubstituted alkyl group, a group containing a glycidyl group, a group containing an oxetanyl group, or a hydrogen atom. [ka]

[0010] 4) The hard coat film according to any one of 1) to 3), wherein the molar ratio of the structural unit represented by the following formula (3) contained in the condensate to the structural unit represented by the following formula (4) is [structural unit represented by formula (3)] / [structural unit represented by formula (4)] of 0.8 or more and less than 5. (In formula (3), R a is R in equation (1). 1 and R in formula (2) 4 In equation (4), R a is R in equation (1). 1 and R in formula (2) 4 where Z is a hydroxyl group or an alkoxy group having an alkyl group. [ka] [ka]

[0011] 5) The hard coat film according to any one of 1) to 4), which has a total light transmittance of 90% or more.

[0012] 6) The hard coat film according to any one of 1) to 5) above, wherein the YI value is 2.0 or less.

[0013] 7) A hard coat film according to any one of 1) to 6), which can be bent with the hard coat layer facing inner surface at a radius of 1 mm or less in a mandrel bending test according to JIS-K5600.

[0014] 8) A hard coat film according to any one of 1) to 7), characterized in that it can be bent with the hard coat layer facing outward at a radius of 5 mm or less in a mandrel bending test in accordance with JIS-K5600.

[0015] 9) A hard coat film according to any one of 1) to 8) above, which can be repeatedly bent at a radius of 2.5 mm 50,000 times or more.

[0016] 10) The hard coat film according to any one of 1) to 9), which has a hardness of 6B or more in a pencil hardness test according to JIS-K5600.

[0017] 11) A hard coat film according to any one of 1) to 10), which, when placed between two linear polarizing plates whose optical axes are parallel, does not produce rainbow unevenness in transmitted light from a white light source.

[0018] 12) The hard coat film according to any one of 1) to 11), wherein the transparent resin film is one selected from the group consisting of a (meth)acrylic resin film, a triacetyl cellulose film, and a polycarbonate film.

[0019] 13) A method for producing a hard coat film according to any one of 1) to 12), characterized in that after a step of applying a composition containing a condensate and a photocationic initiator onto a transparent resin film, a step of irradiating with active energy rays is carried out.

[0020] 14) A display comprising the hard coat film according to any one of 1) to 12). [Effects of the Invention]

[0021] The present invention provides a flexible hard-coated film that has excellent folding recovery and low retardation, and combines hardness and flexibility. It also provides a method for producing the hard-coated film and a display including the hard-coated film. DETAILED DESCRIPTION OF THE INVENTION

[0022] The hard coat film of the present invention has a transparent resin film layer and a hard coat layer, At least one surface of a transparent resin film layer having a thickness of 20 to 80 μm, a hard coat layer having a thickness of 3 to 49 μm, which is a cured product of a condensation product composition containing a silane compound having an alicyclic epoxy group in the molecule and represented by the following general formula (1), The front retardation is 0 to 20 nm, The bending angle is 70 to 180°, as measured after bending at a radius of 3 mm for 24 hours in an environment of 60°C and 90% RH and then removing the load. (In the formula (1), R 1 is a group containing an alicyclic epoxy group, and R 2 is a hydrogen atom or an alkyl group, and R 3 is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and x is an integer of 1 to 3. [ka]

[0023] The condensation product containing the silane compound having an alicyclic epoxy group in the molecule represented by general formula (1) of the present invention is also referred to as a condensation product or a silsesquioxane compound.

[0024] [Silsesquioxane compounds] The hard coat composition used in the hard coat film of the present invention contains a silsesquioxane compound as an essential component. The silsesquioxane compound is a condensation product containing a silane compound represented by the following general formula (1), in which R 1represents a group containing an alicyclic epoxy group. Examples of the group containing an alicyclic epoxy group include an alicyclic epoxy group, an alkyl group having an alicyclic epoxy group as a substituent, and an ethylene glycol group having an alicyclic epoxy group as a substituent. From the viewpoint of heat resistance and flex resistance, an alkyl group having an alicyclic epoxy group as a substituent is preferred. Specific examples of such alkyl groups having an alicyclic epoxy group as a substituent include a (3,4-epoxycyclohexyl)methyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-(3,4-epoxycyclohexyl)propyl group, a 4-(3,4-epoxycyclohexyl)butyl group, a 5-(3,4-epoxycyclohexyl)pentyl group, a 6-(3,4-epoxycyclohexyl)hexyl group, a 7-(3,4-epoxycyclohexyl)heptyl group, an 8-(3,4-epoxycyclohexyl)octyl group, a 9-(3,4-epoxycyclohexyl)nonyl group, a 10-(3,4-epoxycyclohexyl)butyl group, a 11-(3,4-epoxycyclohexyl)butyl group, a 12-(3,4-epoxycyclohexyl)butyl group, a 13-(3,4-epoxycyclohexyl)butyl group, a 14-(3,4-epoxycyclohexyl)butyl group, a 15-(3,4-epoxycyclohexyl)butyl group, a 16-(3,4-epoxycyclohexyl)butyl group, a 17-(3,4-epoxycyclohexyl)butyl group, a 18-(3,4-epoxycyclohexyl)butyl group, a 19-(3,4-epoxycyclohexyl)butyl group, a 20-(3,4-epoxycyclohexyl)butyl group, a 21-(3,4-epoxycyclohexyl)butyl group, a 22-(3,4-epoxycyclohexyl)butyl group, a 23-(3,4-epoxycyclohexyl)butyl group, a 24-(3,4-epoxycyclohexyl)butyl group, a 25-(3,4-epoxycyclohexyl)butyl group, a 26-(3,4-epoxycyclohexyl)butyl group, a 27

[0033] Examples of epoxycyclohexyl groups include 11-(3,4-epoxycyclohexyl)decyl group, 11-(3,4-epoxycyclohexyl)undecyl group, 12-(3,4-epoxycyclohexyl)dodecyl group, 13-(3,4-epoxycyclohexyl)tridecyl group, 14-(3,4-epoxycyclohexyl)tetradecyl group, 15-(3,4-epoxycyclohexyl)pentadecyl group, 16-(3,4-epoxycyclohexyl)hexadecyl group, 2-(3,4-epoxycyclohexyl)isopropyl group, 3-(3,4-epoxycyclohexyl)isobutyl group, and 6-(3,4-epoxycyclohexyl)ethylhexyl group.

[0025] In general formula (1), R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, and an ethylhexyl group. From the viewpoint of facilitating hydrolysis and condensation of a silane compound having a hydrolyzable silyl group, R 2 The alkyl group is preferably a methyl group, an ethyl group or a propyl group, and most preferably a methyl group.

[0026] In general formula (1), R 3 represents a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 25 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. Examples of such hydrocarbon groups include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, an ethylhexyl group, a benzyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a phenethyl group.

[0027] In general formula (1), x is an integer of 1 to 3, and is appropriately selected depending on the physical properties required for the hard coat.

[0028] Specific examples of the silane compound (1) include (3,4-epoxycyclohexyl)trimethoxysilane, (3,4-epoxycyclohexyl)methyldimethoxysilane, 3,4-epoxycyclohexyl)dimethylmethoxysilane, (3,4-epoxycyclohexyl)triethoxysilane, (3,4-epoxycyclohexyl)methyldiethoxysilane, (3,4-epoxycyclohexyl)dimethylethoxysilane, {(3,4-epoxycyclohexyl)methyl}trimethoxysilane, {(3,4-epoxycyclohexyl) {(3,4-epoxycyclohexyl)methyl}methyldimethoxysilane, {(3,4-epoxycyclohexyl)methyl}dimethylmethoxysilane, {(3,4-epoxycyclohexyl)methyl}triethoxysilane, {(3,4-epoxycyclohexyl)methyl}methyldiethoxysilane, {(3,4-epoxycyclohexyl)methyl}dimethylethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}trimethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}methyldimethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl {2-(3,4-epoxycyclohexyl)ethyl}dimethylmethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}triethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}methyldiethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}dimethylethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}trimethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}methyldimethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}dimethylmethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}dimethyl {3-(3,4-epoxycyclohexyl)propyl}triethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}methyldiethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}dimethylethoxysilane, {4-(3,4-epoxycyclohexyl)butyl}trimethoxysilane, {4-(3,4-epoxycyclohexyl)butyl}methyldimethoxysilane, {4-(3,4-epoxycyclohexyl)butyl}dimethylmethoxysilane, {4-(3,4-epoxycyclohexyl)butyl}triethoxysilane, {4-(3,{4-epoxycyclohexyl)butyl}methyldiethoxysilane, {4-(3,4-epoxycyclohexyl)butyl}dimethylethoxysilane, {5-(3,4-epoxycyclohexyl)pentyl}trimethoxysilane, {5-(3,4-epoxycyclohexyl)pentyl}methyldimethoxysilane, {5-(3,4-epoxycyclohexyl)pentyl}dimethylmethoxysilane, {5-(3,4-epoxycyclohexyl)pentyl}triethoxysilane, {5-(3,4-epoxycyclohexyl)pentyl}methyldiethoxysilane silane, {5-(3,4-epoxycyclohexyl)pentyl}dimethylethoxysilane, {6-(3,4-epoxycyclohexyl)hexyl}trimethoxysilane, {6-(3,4-epoxycyclohexyl)hexyl}methyldimethoxysilane, {6-(3,4-epoxycyclohexyl)hexyl}dimethylmethoxysilane, {6-(3,4-epoxycyclohexyl)hexyl}triethoxysilane, {6-(3,4-epoxycyclohexyl)hexyl}methyldiethoxysilane, {6-(3,4-epoxycyclohexyl)hexyl} Dimethylethoxysilane, {8-(3,4-epoxycyclohexyl)octyl}trimethoxysilane, {8-(3,4-epoxycyclohexyl)octyl}methyldimethoxysilane, {8-(3,4-epoxycyclohexyl)octyl}dimethylmethoxysilane, {8-(3,4-epoxycyclohexyl)octyl}triethoxysilane, {8-(3,4-epoxycyclohexyl)octyl}methyldiethoxysilane, {8-(3,4-epoxycyclohexyl)octyl}dimethylethoxysilane, {10-(3,4-epoxycyclohexyl)octyl}dimethylethoxysilane {10-(3,4-epoxycyclohexyl)decyl}trimethoxysilane, {10-(3,4-epoxycyclohexyl)decyl}methyldimethoxysilane, {10-(3,4-epoxycyclohexyl)decyl}dimethylmethoxysilane, {10-(3,4-epoxycyclohexyl)decyl}triethoxysilane, {10-(3,4-epoxycyclohexyl)decyl}methyldiethoxysilane, {10-(3,4-epoxycyclohexyl)decyl}dimethylethoxysilane, {12-(3,4-epoxycyclohexyl)dodecyl}trimethoxysilane, {12-(3,{12-(3,4-epoxycyclohexyl)dodecyl}methyldimethoxysilane, {12-(3,4-epoxycyclohexyl)dodecyl}dimethylmethoxysilane, {12-(3,4-epoxycyclohexyl)dodecyl}triethoxysilane, {12-(3,4-epoxycyclohexyl)dodecyl}methyldiethoxysilane, {12-(3,4-epoxycyclohexyl)dodecyl}dimethylethoxysilane, {14-(3,4-epoxycyclohexyl)tetradecyl}trimethoxysilane, {14-(3,4-epoxycyclohexyl)tetradecyl}methyldimethoxysilane, {14-(3,4-epoxycyclohexyl)tetradecyl}dimethylmethoxysilane, {14-(3,4-epoxycyclohexyl)tetradecyl}triethoxysilane, Examples of the epoxy group-containing silanes include {14-(3,4-epoxycyclohexyl)tetradecyl}methyldiethoxysilane, {14-(3,4-epoxycyclohexyl)tetradecyl}dimethylethoxysilane, {16-(3,4-epoxycyclohexyl)hexadecyl}trimethoxysilane, {16-(3,4-epoxycyclohexyl)hexadecyl}methyldimethoxysilane, {16-(3,4-epoxycyclohexyl)hexadecyl}dimethylmethoxysilane, {16-(3,4-epoxycyclohexyl)hexadecyl}triethoxysilane, {16-(3,4-epoxycyclohexyl)hexadecyl}methyldiethoxysilane, and {16-(3,4-epoxycyclohexyl)hexadecyl}dimethylethoxysilane.

[0029] In addition to the silane compound represented by general formula (1), the silane compound condensate can be co-condensed with a silane compound represented by general formula (2) different from the silane compound represented by general formula (1). In the case of co-condensation, it is preferable that [structural unit represented by general formula (1)] / ([structural unit represented by general formula (1)]+[structural unit represented by general formula (2)]) is 0.5 or more and 1.0 or less. Within this range, the hardness and flex resistance of the hard coat film tend to be good. [ka]

[0030] In general formula (2), R 4 is a group that does not contain an alicyclic epoxy group and contains a substituted or unsubstituted double bond, a group that contains a substituted or unsubstituted cycloalkyl group, a group that contains a substituted or unsubstituted aromatic ring, a substituted or unsubstituted alkyl group, a group that has a glycidyl group, a group that has an oxetanyl group, or a hydrogen atom. Among these, a group that has a glycidyl group may be preferred from the viewpoints of reactivity with the silane compound represented by general formula (1) and adhesion to a transparent resin film layer.

[0031] Examples of the substituted or unsubstituted double bond-containing group include a vinyl group, an allyl group, an isopropenyl group, and a (meth)acryloyl group. Examples of the substituted or unsubstituted cycloalkyl group-containing group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a cyclobutylethyl group, a cyclopentylethyl group, and a cyclohexylethyl group. Examples of the substituted or unsubstituted aromatic ring-containing group include a phenyl group, a 4-methylphenyl group, a tolyl group, and a naphthyl group. Examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isopropyl group, an isobutyl group, a cyclohexyl group, and an ethylhexyl group. Examples of the group having a glycidyl group include a glycidyloxymethyl group, a 2-glycidyloxyethyl group, a 3-glycidyloxypropyl group, a 4-glycidyloxybutyl group, a 5-glycidyloxypentyl group, a 6-glycidyloxyhexyl group, a 7-glycidyloxyheptyl group, an 8-glycidyloxyoctyl group, a 9-glycidyloxynonyl group, a 10-glycidyloxydecyl group, an 11-glycidyloxyundecyl group, a 12-glycidyloxydodecyl group, a 14-glycidyloxytetradecyl group, a 16-glycidyloxyhexadecyl group, etc. Examples of the group having an oxetanyl group include an oxetanylmethyl group, a 3-methyl-3-oxetanylmethoxymethyl group, a 3-ethyl-3-oxetanylmethoxymethyl group, etc.

[0032] The general formula (2) is not particularly limited, but may be R 4 Examples of the compound in which is an alkenyl group include vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, allyltrimethoxysilane, allylmethyldimethoxysilane, allyltriethoxysilane, and allylmethyldiethoxysilane.

[0033] R 4 Examples of the compound in which is a (meth)acryloyl group-substituted alkyl group include 1-(meth)acryloyloxymethyltrimethoxysilane, 1-(meth)acryloyloxymethylmethyldimethoxysilane, 1-(meth)acryloyloxymethyltriethoxysilane, 1-(meth)acryloyloxymethylmethyldiethoxysilane, 2-(meth)acryloyloxyethyltrimethoxysilane, 2-(meth)acryloyloxyethylmethyldimethoxysilane, 2-(meth)acryloyloxyethyltriethoxysilane, 2-(meth)acryloyloxyethylmethyldiethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyl Examples of such silane include diethoxysilane, 4-(meth)acryloyloxybutyltrimethoxysilane, 4-(meth)acryloyloxybutylmethyldimethoxysilane, 4-(meth)acryloyloxybutyltriethoxysilane, 4-(meth)acryloyloxybutylmethyldiethoxysilane, 6-(meth)acryloyloxyhexyltrimethoxysilane, 6-(meth)acryloyloxyhexylmethyldimethoxysilane, 6-(meth)acryloyloxyhexyltriethoxysilane, 6-(meth)acryloyloxyhexylmethyldiethoxysilane, 8-(meth)acryloyloxyoctyltrimethoxysilane, 8-(meth)acryloyloxyoctylmethyldimethoxysilane, 8-(meth)acryloyloxyoctyltriethoxysilane, and 8-(meth)acryloyloxyoctylmethyldiethoxysilane. In terms of reactivity with additives, etc., the (meth)acryloyl-substituted alkyl group may preferably be an acryloyl-substituted alkyl group.

[0034] R 4Examples of the compound in which is a cyclohexyl-substituted alkyl group include cyclohexylmethyltrimethoxysilane, cyclohexylmethyltriethoxysilane, 2-cyclohexylethyltrimethoxysilane, 2-cyclohexylethyltriethoxysilane, 3-cyclohexylpropyltrimethoxysilane, 3-cyclohexylpropyltriethoxysilane, 4-cyclohexylbutyltrimethoxysilane, 4-cyclohexylbutyltriethoxysilane, 5-cyclohexylpentyltrimethoxysilane, 5-cyclohexylpentyltriethoxysilane, 6-cyclohexylhexyltrimethoxysilane, and 6-cyclohexylhexyltriethoxysilane.

[0035] R 4 Examples of the compound in which is a phenyl-substituted alkyl group include benzyltrimethoxysilane, benzyltriethoxysilane, 2-phenylethyltrimethoxysilane, 2-phenylethyltriethoxysilane, 3-phenylpropyltrimethoxysilane, 3-phenylpropyltriethoxysilane, 4-phenylbutyltrimethoxysilane, 4-phenylbutyltriethoxysilane, 5-phenylpentyltrimethoxysilane, 5-phenylpentyltriethoxysilane, 6-phenylhexyltrimethoxysilane, and 6-phenylhexyltriethoxysilane.

[0036] R 4 Examples of compounds in which is a substituted aryl group include p-styryltrimethoxysilane and p-styryltriethoxysilane.

[0037] R 4is an unsubstituted alkyl group, examples of which include methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, ethyltrimethoxysilane, ethylmethyldimethoxysilane, ethyltriethoxysilane, ethylmethyldiethoxysilane, propyltrimethoxysilane, propylmethyldimethoxysilane, propyltriethoxysilane, propylmethyldiethoxysilane, butyltrimethoxysilane, butylmethyldimethoxysilane, butyltriethoxysilane, butylmethyldiethoxysilane, hexyltrimethoxysilane, hexylmethyldimethoxysilane, hexyltriethoxysilane, hexylmethyldiethoxysilane, oxyltrimethoxysilane, oxylmethyldimethoxysilane, oxyltriethoxysilane, oxylmethyldiethoxysilane, and the like.

[0038] R 4Examples of silanes in which the glycidyl group is present include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 4-glycidyloxybutyltrimethoxysilane, 4-glycidyloxybutylmethyldimethoxysilane, 4-glycidyloxybutyltriethoxysilane, 4-glycidyloxybutylmethyldiethoxysilane, 5-glycidyloxypentyltrimethoxysilane, 5-glycidyloxypentyltriethoxysilane, and 5-glycidyloxypropylmethyldiethoxysilane. butylmethyldimethoxysilane, 5-glycidyloxypentyltriethoxysilane, 5-glycidyloxypentylmethyldiethoxysilane, 6-glycidyloxyhexyltrimethoxysilane, 6-glycidyloxyhexylmethyldimethoxysilane, 6-glycidyloxyhexyltriethoxysilane, 6-glycidyloxyhexylmethyldiethoxysilane, 7-glycidyloxyheptyltrimethoxysilane, 7-glycidyloxyheptylmethyldimethoxysilane, 7-glycidyloxyheptyltriethoxysilane, 7-glycidyloxy Heptylmethyldiethoxysilane, 8-glycidyloxyoctyltrimethoxysilane, 8-glycidyloxyoctylmethyldimethoxysilane, 8-glycidyloxyoctyltriethoxysilane, 8-glycidyloxyoctylmethyldiethoxysilane, 9-glycidyloxynonyltrimethoxysilane, 9-glycidyloxynonylmethyldimethoxysilane, 9-glycidyloxynonyltriethoxysilane, 9-glycidyloxynonylmethyldiethoxysilane, 10-glycidyloxydecyltrimethoxysilane, 10-glycidyloxydecyl silmethyldimethoxysilane, 10-glycidyloxydecyltriethoxysilane, 10-glycidyloxydecylmethyldiethoxysilane, 11-glycidyloxyundecyltrimethoxysilane, 11-glycidyloxyundecylmethyldimethoxysilane, 11-glycidyloxyundecyltriethoxysilane, 11-glycidyloxyundecylmethyldiethoxysilane, 12-glycidyloxydodecyltrimethoxysilane, 12-glycidyloxydodecylmethyldimethoxysilane, 12-glycidyloxydodecyltriethoxysilane,12-Glycidyloxydodecylmethyldiethoxysilane, 13-glycidyloxytridecyltrimethoxysilane, 13-glycidyloxytridecylmethyldimethoxysilane, 13-glycidyloxytridecyltriethoxysilane, 13-glycidyloxytridecylmethyldiethoxysilane, 14-glycidyloxytetradecyltrimethoxysilane, 14-glycidyloxytetradecylmethyldimethoxysilane, 14-glycidyloxytetradecyltriethoxysilane, 14-glycidyloxytetradecylmethyldi Examples of suitable silanes include ethoxysilane, 15-glycidyloxypentadecyltrimethoxysilane, 15-glycidyloxypentadecylmethyldimethoxysilane, 15-glycidyloxypentadecyltriethoxysilane, 15-glycidyloxypentadecylmethyldiethoxysilane, 16-glycidyloxyhexadecyltrimethoxysilane, 16-glycidyloxyhexadecylmethyldimethoxysilane, 16-glycidyloxyhexadecyltriethoxysilane, and 16-glycidyloxyhexadecylmethyldiethoxysilane. A glycidyl group may be preferred in terms of reactivity with the alicyclic epoxy group of the condensate.

[0039] R 4In the case where R is an oxetanyl group, examples thereof include 1-oxetanyloxymethyltrimethoxysilane, 1-oxetanyloxymethylmethyldimethoxysilane, 1-oxetanyloxymethyltriethoxysilane, 1-oxetanyloxymethylmethyldiethoxysilane, 2-oxetanyloxyethyltrimethoxysilane, 2-oxetanyloxyethylmethyldimethoxysilane, 2-oxetanyloxyethyltriethoxysilane, 2-oxetanyloxyethylmethyldiethoxysilane, 3-oxetanyloxypropyltrimethoxysilane, 3-oxetanyloxypropylmethyldimethoxysilane, 3-oxetanyloxypropyltriethoxysilane, and 3-oxetanyloxypropylmethyldiethoxysilane. Examples thereof include silane, 4-oxetanyloxybutyltrimethoxysilane, 4-oxetanyloxybutylmethyldimethoxysilane, 4-oxetanyloxybutyltriethoxysilane, 4-oxetanyloxybutylmethyldiethoxysilane, 6-oxetanyloxyhexyltrimethoxysilane, 6-oxetanyloxyhexylmethyldimethoxysilane, 6-oxetanyloxyhexyltriethoxysilane, 6-oxetanyloxyhexylmethyldiethoxysilane, 8-oxetanyloxyoctyltrimethoxysilane, 8-oxetanyloxyoctylmethyldimethoxysilane, 8-oxetanyloxyoctyltriethoxysilane, and 8-oxetanyloxyoctylmethyldiethoxysilane.

[0040] The number-average molecular weight of the silsesquioxane compound of the present invention is not particularly limited, but is preferably 500 or more from the viewpoint of increasing the hardness of the cured product. Furthermore, from the viewpoint of suppressing the volatilization of the siloxane compound, the number-average molecular weight of the siloxane compound is preferably 500 or more. On the other hand, if the molecular weight is excessively large, cloudiness may occur due to reduced compatibility with other compositions. Therefore, the number-average molecular weight of the siloxane compound is preferably 20,000 or less.

[0041] The number average molecular weight of the silsesquioxane compound of the present invention can be controlled by appropriately selecting the amount of water and the type and amount of catalyst used in the reaction. For example, the number average molecular weight can be increased by increasing the amount of water initially charged.

[0042] SiO contained in the silane compound represented by general formula (1) 3 / 2 (corresponding to x=3 in general formula (1)), SiO 2 / 2 (corresponding to x=2 in general formula (1)), SiO 1 / 2 When the structures (corresponding to x=1 in general formula (1)) are respectively T structure, D structure, and M structure, the ratio of [T structure] to [T structure] + [D structure] + [M structure] is not particularly limited, but is preferably 0.2 or more and 1.0 or less, more preferably 0.4 or more and 1.0 or less, and even more preferably 0.6 or more and 1.0 or less. If the ratio of [T structure] is less than 0.2, sufficient pencil hardness may not be obtained. From the viewpoint of increasing the crosslinking density and improving the hardness of the cured product, it is preferable that the residual rate of the epoxy structure in the silsesquioxane compound obtained by hydrolysis and condensation of the silane compound represented by general formula (1) is high.

[0043] The same applies to the case where the silane compound represented by the general formula (2) is co-condensed with the condensate of the silane compound. 3 / 2 (corresponding to x=3 in general formulas (1) and (2)), SiO 2 / 2 (corresponding to x=2 in general formulas (1) and (2)), SiO 1 / 2 When the structures (corresponding to x=1 in general formulas (1) and (2)) are respectively designated as T structure, D structure, and M structure, the ratio of [T structure] to [T structure] + [D structure] + [M structure] is not particularly limited, but is preferably 0.2 or more and 1.0 or less, more preferably 0.4 or more and 1.0 or less, and even more preferably 0.6 or more and 1.0 or less. If the ratio of [T structure] is less than 0.2, sufficient pencil hardness may not be obtained. From the viewpoint of increasing the crosslinking density and improving the hardness of the cured product, it is preferable that the residual rate of epoxy structures in the silsesquioxane compounds obtained by hydrolysis and condensation of the silane compounds represented by general formula (1) and general formula (2) is high.

[0044] The silsesquioxane compound of the present invention is formed by hydrolysis and condensation of a silane compound represented by general formula (1), and contains a structural unit represented by general formula (3) or (4). The ratio [T3 isomer] / [T2 isomer] of the structural unit represented by formula (3) (a structure in which all three alkoxysilanes in a silane compound having a T unit structure where x = 3 in general formulas (1) and (2) have undergone a condensation reaction to form an Si-O-Si structure; hereinafter referred to as [T3 isomer]) to the structural unit represented by formula (4) (a structure in which two of the three alkoxysilanes in a silane compound having a T unit structure where x = 3 in general formulas (1) and (2) have undergone a condensation reaction to form an Si-O-Si structure; hereinafter referred to as [T2 isomer]) is preferably 0.8 or more and less than 5, more preferably 1 or more and less than 4, and even more preferably 1.5 or more and less than 3. A hard coat film having a hard coat layer containing a cured product of the silsesquioxane compound of the present invention may exhibit excellent flex resistance by adjusting the ratio of the T3 isomer to the T2 isomer, [T3 isomer] / [T2 isomer], to less than 5. If the content of the T3 isomer in the condensate is high and the ratio [T3 isomer] / [T2 isomer] is 5 or more, the resulting condensate will have a dense structure and will have reduced flexibility, which may result in reduced flex resistance when formed into a hard coat film. [ka] [ka]

[0045] In general formula (3) and general formula (4), R a is R in equation (1). 1 is the same as

[0046] In general formulas (3) and (4), Z represents a hydroxyl group or an alkoxy group having an alkyl group of 1 to 10 carbon atoms. Examples of such an alkoxy group having an alkyl group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, and a decyloxy group.

[0047] The contents and ratios of the T3 and T2 isomers in the silsesquioxane compound of the present invention are, for example, 29 It can be calculated by Si-NMR measurement. 29 In Si-NMR measurements, the chemical shift of the silicon atom in the T3 isomer is different from that in the T2 isomer, and signals are displayed at different positions in the spectrum. Therefore, the ratio [T3 isomer] / [T2 isomer] can be calculated by calculating the integral value of each signal.

[0048] The same applies when a silane compound represented by general formula (2) is co-condensed with a silane compound condensate, and the silsesquioxane compound is formed by hydrolysis and condensation of the silane compounds represented by general formulas (1) and (2), and contains a structural unit represented by general formula (3) or (4). The ratio [T3 isomer] / [T2 isomer] of the structural unit represented by formula (3) (a structure in which all three alkoxysilanes in a silane compound having a T unit structure where x = 3 in general formulas (1) and (2) have condensed to form an Si-O-Si structure; hereinafter referred to as [T3 isomer]) to the structural unit represented by formula (4) (a structure in which two of the three alkoxysilanes in a silane compound having a T unit structure where x = 3 in general formulas (1) and (2) have condensed to form an Si-O-Si structure; hereinafter referred to as [T2 isomer]) is preferably 0.8 or more and less than 5, more preferably 1 or more and less than 4, and even more preferably 1.5 or more and less than 3. A hard coat film having a hard coat layer containing a cured product of the silsesquioxane compound of the present invention may exhibit excellent flex resistance by adjusting the ratio of the T3 isomer to the T2 isomer, [T3 isomer] / [T2 isomer], to less than 5. If the content of the T3 isomer in the condensate is high and the ratio [T3 isomer] / [T2 isomer] is 5 or more, the resulting condensate will have a dense structure and will have reduced flexibility, which may result in reduced flex resistance when formed into a hard coat film.

[0049] In general formula (3) and general formula (4), R a is R in equation (1). 1 and R in formula (2) 4 is the same as

[0050] The ratio of the T3 isomer to the T2 isomer in the silsesquioxane compound of the present invention, [T3 isomer] / [T2 isomer], can be controlled by appropriately selecting the amount of water and the type and amount of catalyst used in the reaction. For example, the ratio [T3 isomer] / [T2 isomer] can be increased by increasing the amount of catalyst initially charged. Furthermore, the use of a neutral salt catalyst makes it easy to control the ratio of the T3 isomer to the T2 isomer, [T3 isomer] / [T2 isomer], to 0.8 or more and less than 5.

[0051] The amount of water required for the hydrolysis and condensation reactions is determined by the amount of OR bonded directly to the silicon atom. 2 group (OR in general formula (1) and general formula (2) 2 The amount of water is preferably 0.3 to 3 equivalents, more preferably 0.5 to 2 equivalents, per equivalent of the group. 2 The hydrolysis of the groups may not proceed sufficiently, reducing the surface hardness of the hard coat film. If the amount exceeds 3 equivalents, the reaction rate of the hydrolysis and condensation reaction may be too high, resulting in the formation of high molecular weight condensates, which may reduce the physical properties and transparency of the cured film.

[0052] The residual ratio of the epoxy structure, i.e., the ratio of the number of moles of the epoxy structure in the silsesquioxane compound obtained by condensation to the number of moles of the epoxy structure in the raw material silane compound (1), is preferably 20% or more, more preferably 40% or more, and even more preferably 60% or more. 1 It can be calculated by H-NMR measurement.

[0053] In the present invention, the hydrolysis and condensation reactions can be carried out by known methods in the presence of a basic catalyst, an acidic catalyst, or a neutral salt catalyst. Among these, the use of a neutral salt catalyst is preferred. By carrying out the hydrolysis and condensation reactions in the presence of a neutral salt catalyst, a silsesquioxane compound can be obtained without deactivating the epoxy groups before, after, or during storage of the hydrolysis and condensation reactions.

[0054] Furthermore, because the neutral salt catalyst itself does not corrode the manufacturing or storage containers, it can be used without restrictions on the materials of the manufacturing or storage equipment. This is because, in general, acid and base catalysts react electrophilically or nucleophilically with various substances, or change the hydrogen ion or hydroxide ion concentration in the reaction solution, causing these ions to contribute to the reaction, whereas neutral salts have extremely low reactivity as described above.

[0055] Furthermore, when an acid or base catalyst is used in the hydrolysis and condensation reactions, it is necessary to go through an acid / base removal step or a neutralization step for the reasons mentioned above. These steps are undesirable because they are cumbersome and reduce the yield. To address these issues, the use of a neutral salt catalyst is preferable because it does not require these steps.

[0056] The neutral salt used in the present invention is a normal salt consisting of a strong acid and a strong base, and is a salt consisting of a combination of a cation selected from the group consisting of Group 1 element ions and Group 2 element ions and an anion selected from the group consisting of chloride ions, bromide ions, and iodide ions.

[0057] Specific examples of the neutral salt in the present invention include lithium chloride, sodium chloride, potassium chloride, beryllium chloride, magnesium chloride, calcium chloride, lithium bromide, sodium bromide, potassium bromide, beryllium bromide, magnesium bromide, calcium bromide, lithium iodide, sodium iodide, potassium iodide, beryllium iodide, magnesium iodide, and calcium iodide.

[0058] In the present invention, the greater the amount of neutral salt used, the more the hydrolysis and condensation reaction of the silane compound is accelerated. However, when the transparency of the condensate and the purification process are taken into consideration, the smaller the amount added, the better.

[0059] The amount of the neutral salt used in the present invention is preferably 0.000001 to 0.1 mol, particularly preferably 0.000005 to 0.01 mol, per mol of the hydrolyzable silyl group of the silane compound. The amount of the neutral salt remaining in the silsesquioxane compound is preferably 1 ppm to 10,000 ppm, more preferably 50 ppm to 5,000 ppm, and even more preferably 100 ppm to 1,000 ppm. In the production of the silsesquioxane compound of the present invention, in consideration of safety during production, it is preferable to carry out the production while refluxing the dilution solvent, alcohol generated by hydrolysis, etc.

[0060] The diluent solvent used in the production of the silsesquioxane compound of the present invention is preferably a water-soluble alcohol or ether compound.

[0061] The reason for this is that the silane compound (1) used in the present invention often has low compatibility with the neutral salt and water used for hydrolysis, and therefore, in order to smoothly proceed with the reaction, it is preferable that the reaction solution is compatible with the neutral salt and water used for hydrolysis.

[0062] The boiling point of the dilution solvent used in producing the silsesquioxane compound of the present invention is preferably 40°C or higher and 200°C or lower, more preferably 50°C or higher and 200°C or lower, and even more preferably 60°C or higher and 200°C or lower.

[0063] If the boiling point of the dilution solvent is less than 40°C, the dilution solvent will reflux at low temperatures, slowing the reaction rate.If the boiling point of the dilution solvent is more than 200°C, the boiling point will be too high, making it difficult to remove the dilution solvent after the reaction, and it may be necessary to incorporate a complicated process such as liquid separation and extraction.

[0064] Specific examples of diluent solvents used in producing the silsesquioxane compound of the present invention include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, 1-methoxy-2-propanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, etc. These diluents may be used alone or in combination of two or more.

[0065] The reaction temperature in the production of the silsesquioxane compound of the present invention is preferably in the range of 40 to 200°C, more preferably in the range of 50 to 200°C, and even more preferably in the range of 60 to 200°C.

[0066] If the reaction temperature is lower than 40°C, the catalytic activity of the neutral salt tends to decrease, significantly increasing the reaction time. If the reaction temperature is higher than 200°C, there is a risk that the organic functional groups may undergo side reactions and become inactivated.

[0067] When a silane compound represented by general formula (2) is co-condensed with a silane compound condensate, the number of epoxy groups contained in one molecule of the silsesquioxane compound is preferably as large as possible in order to improve the mechanical strength of the cured product. During the reaction of the silane compounds, the molar ratio of the silane compound represented by general formula (2) to the silane compound represented by general formula (1) is preferably 1 or less, more preferably 0.5 or less. If the molar ratio of the silane compound represented by general formula (2) to the silane compound represented by general formula (1) is too high, the surface hardness of the resulting hard coat layer may decrease. The molar ratio of the silane compound represented by general formula (2) to the silane compound represented by general formula (1) may be 0.

[0068] [Hard Coat Composition] The hard coat composition of the hard coat film of the present invention is a hard coat composition containing the above-mentioned silsesquioxane compound of the present invention as an essential component. The hard coat composition of the hard coat film of the present invention may further contain other components such as a photocationic initiator, a surface conditioner, a surface modifier, etc. From the viewpoint of forming a hard coat cured film having excellent mechanical strength, the content of the silsesquioxane compound in the hard coat composition is preferably 40 parts by weight or more, more preferably 50 parts by weight or more, and even more preferably 60 parts by weight or more, per 100 parts by weight of the total solid content.

[0069] <Curing catalyst> The hard coat composition preferably contains a thermal cationic polymerization initiator or a photo-cationic polymerization initiator as a curing catalyst. The thermal cationic polymerization initiator is a compound that generates an acid upon heating (thermal acid generator), and the photo-cationic polymerization initiator is a compound that generates an acid upon irradiation with active energy rays (photo-acid generator). The acid generated by heat and the photo-acid generator promotes a ring-opening reaction and a polymerization reaction of the epoxy groups contained in the silsesquioxane compound, forming intermolecular crosslinks and curing the hard coat material.

[0070] Examples of photoacid generators include onium salts that combine anions (strong acids) such as antimony hexafluoride, boron tetrafluoride, phosphorus hexafluoride, fluoroalkyl phosphorus fluoride, and fluoroalkyl gallium fluoride with cations such as sulfonium, ammonium, phosphonium, iodonium, and selenium; iron-arene complexes; silanol-metal chelate complexes; sulfonic acid derivatives such as disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imide sulfonates, and benzoin sulfonates; and organic halogen compounds.

[0071] Among the photoacid generators, as the cation, aromatic sulfonium or aromatic iodonium is preferred, because it has high stability in the hard coat composition containing the polyorganosiloxane compound having epoxy group.Among the photoacid generators, as the anion, fluoroantimonate-based anion, fluoroborate-based anion, fluorophosphate-based anion, fluorogallium-based anion, etc. are preferred, because they have strong acid strength, and therefore can easily obtain a hard coat layer that is excellent in surface hardness and adhesion to resin substrate.

[0072] Among these, fluorophosphate-based anions, fluoroborate-based anions, fluorogallium-based anions, and the like are more preferred as counter anions that have a low environmental impact and are highly safe for the environment and the human body.

[0073] Specific examples of such photoacid generators include CPI-100P, CPI101A, CPI200K, CPI210S, CPI310B, CPI310FG, CPI410S, and IK-1 manufactured by San-Apro Co., Ltd.; WPI-113, WPI-116, WPI-170, and WPI-124 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.; and Bluesil PI2074 and Silicolyse UVCATA243 manufactured by Arakawa Chemical Industries, Ltd., but are not limited to products from these manufacturers.

[0074] The content of the photocationic polymerization initiator in the hard coat composition is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and even more preferably 0.2 to 2 parts by weight, relative to 100 parts by weight of the silsesquioxane compound.

[0075] <Leveling agent> The hard coat composition of the hard coat film of the present invention may further contain a silicone-based leveling agent and / or a fluorine-based leveling agent as a leveling agent. By including a leveling agent, it is possible to reduce the surface tension of the curable composition, improve surface smoothness, improve slipperiness, improve anti-fingerprint properties, and improve scratch resistance. The leveling agent preferably has a group reactive with an epoxy group and / or a hydrolytically condensable group. By including a group reactive with an epoxy group and / or a hydrolytically condensable group, a hard coat layer with better scratch resistance can be obtained.

[0076] The silicone-based leveling agent is not particularly limited, but examples thereof include leveling agents having a polyorganosiloxane skeleton. As with the cationically curable silicone resin, the polyorganosiloxane skeleton may be a polyorganosiloxane formed from M units, D units, T units, or Q units. Typically, a polyorganosiloxane formed from D units is used. Examples of groups bonded to silicon atoms (silicon atoms forming siloxane bonds) in the polyorganosiloxane include alkyl groups and aryl groups. The silicon atom-bonded group may be of one type or two or more types. The number of repeating siloxane units (degree of polymerization) is not particularly limited, but is preferably 2 to 3,000, more preferably 3 to 2,000, and even more preferably 5 to 1,000.

[0077] The fluorine-based leveling agent is not particularly limited, but examples thereof include leveling agents having a fluoroaliphatic hydrocarbon skeleton, etc. The fluoroaliphatic hydrocarbon skeleton is not particularly limited, but examples thereof include fluoro C 1-10 alkanes such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluoro t-butane, fluoropentane, and fluorohexane.

[0078] The fluoroaliphatic hydrocarbon skeleton may have at least some of its hydrogen atoms substituted with fluorine atoms, and from the viewpoint of improving the scratch resistance, slipperiness, and fingerprint resistance of the hard coat layer, it is more preferable that the skeleton be a perfluoroaliphatic hydrocarbon skeleton in which all of its hydrogen atoms are substituted with fluorine atoms.

[0079] The silicone-based leveling agent may have a fluoroaliphatic hydrocarbon group, and the fluorine-based leveling agent may have a polyorganosiloxane group. The leveling agent may contain a hydrolytic condensation group, an epoxy group, or the like, in order to provide various functionalities. groups reactive with groups, radical polymerizable groups, polyether groups, polyester groups, polyurethane groups The leveling agent may have a functional group such as a hydroxyl group. In particular, by using a leveling agent having a hydrolytic condensation group or an epoxy group, it is expected to react with the hydrolytic condensation group or the epoxy group in the hard coat composition, thereby further improving the scratch resistance.

[0080] As the silicone-based leveling agent, commercially available silicone-based leveling agents can be used. Examples of commercially available silicone-based leveling agents include those sold under the trade names "BYK-300", "BYK-301 / 302", "BYK-306", "BYK-307", "BYK-310", "BYK-315", "BYK-313", "BYK-320", "BYK-322", "BYK-323", "BYK-325", "BYK-330", "BYK-331", "BYK-333", "BYK-337", "BYK-341", "BYK-344", "BYK-345 / 346", "BYK-347", and BYK-348, BYK-349, BYK-370, BYK-375, BYK-377, BYK-378, BYK-UV3500, BYK-UV3510, BYK-UV3570, BYK-UV3575, BYK-3550, BYK-3565, BYK-3566, BYK-SILCLEAN3700, BYK-SILCLEAN3701, BYK-SILCLEAN3720 (all manufactured by BYK Japan Co., Ltd.), product name "AC FS 180, AC FS 360, AC S 20 (all manufactured by Algin Chemie), trade names "Polyflow KL-400X", "Polyflow KL-400HF", "Polyflow KL-401", "Polyflow KL-402", "Polyflow KL-403", "Polyflow KL-404" (all manufactured by Kyoeisha Chemical Co., Ltd.), trade names "KP-323", "KP-326", "KP-341", "KP-104", "KP-110", "KP-112" (all manufactured by Shin-Etsu Chemical Co., Ltd.), trade names "LP-7001", "LP-7002", "8032 ADDITIVE", "57 ADDITIVE", "L-7604", "FZ-2110", "FZ-2105", "67 ADDITIVE", "8618 ADDITIVE", "3 ADDITIVE", "56 ADDITIVE" (both manufactured by Toray Dow Corning Co., Ltd.) and the like.

[0081] As the fluorine-based leveling agent, commercially available fluorine-based leveling agents can be used. Commercially available fluorine-based leveling agents include, for example, compounds with the names "Hexafluoroepoxypropane," "3-Perfluorobutyl-1,2-epoxypropane," "3-Perfluorohexyl-1,2-epoxypropane," "1,4-Bis(2',3'-epoxypropyl)-perfluoro-n-butane," and "1,6-Bis(2',3'-epoxypropyl)-perfluoro-n-hexane," trade names "OPTOOL DSX" and "OPTOOL DAC-HP" (all manufactured by Daikin Industries, Ltd.), trade names "SZ-20," "MM-RVSD," "Surflon S-242," "Surflon S-243," "Surflon S-386," "Surflon S-420," "Surflon S-431," "Surflon S-611," "Surflon S-647," "Surflon S-651," "Surflon S-653," "Surflon S-656," and "Surflon S-657." S-658," "Surflon S-693," and "Surflon S-CFJ" (all manufactured by AGC Seimi Chemical Co., Ltd.), trade names "Lumiflon LF200," "Lumiflon LF200MEK," "Lumiflon LF400," "Lumiflon LF552," "Lumiflon LF600X," "Lumiflon LF800," "Lumiflon LF810," "Lumiflon LF910LM," "Lumiflon LF936," "Lumiflon LF9010," "Lumiflon LF9716," and "Lumiflon LF9721" (all manufactured by AGC Corporation), trade name "BYK-340" (manufactured by BYK Japan Co., Ltd.), trade name "AC 110a," "AC 100a" (all manufactured by Algin Chemie), product names "Megafac F-114", "Megafac F-410", "Megafac F-444", "Megafac EXPTP-2066", "Megafac F-430", "Megafac F-472SF", "Megafac F-477", "Megafac F-552", "Megafac F-553", "Megafac F-554", "Megafac F-555", "Megafac F-556", "Megafac F-558", "Megafac F-559", "Megafac F-561", "Megafac F-562", "Megafac F-563", "Megafac F-565", "Megafac F-568", "Megafac F-570", "Megafac "Megafac F-571", "Megafac F-572", "Megafac R-40", "Megafac R-94", "Megafac RS-21", "Megafac RS-56", "Megafac RS-58", "Megafac RS-75", "Megafac RS-75-A", "Megafac RS-78", "Megafac RS-90", "Megafac RS-7054", "Megafac RS-7097", "Megafac RS-7101", "Megafac RS-72-K", "Megafac RS-76-NS", "Megafac EXP TF-1367, Megafac EXP TF-1437, Megafac EXP TF-1537 (all manufactured by DIC Corporation), product names "FC-4430" and "FC-4432" (all manufactured by Sumitomo 3M Limited), product names "Ftergent 100", "Ftergent 100C", "Ftergent 110", "Ftergent 150", "Ftergent 150CH", "Ftergent 208G", "Ftergent FTX-218", "Ftergent 222F", "Ftergent 250", "Ftergent 251", "Ftergent 300", "Ftergent 310", "Ftergent 400SW", "Ftergent 501", "Ftergent 602A", "Ftergent 602ADH2", "Ftergent 650AC", "Ftergent 710FL", "FutergentAK" (all manufactured by Neos Corporation), trade names "PF-136A", "PF-156A", "PF-151N", "PF-636", "PF-6320", "PF-656", "PF-6520", "PF-651", "PF-652", "PF-3320" (all manufactured by Kitamura Chemical Industry Co., Ltd.), trade name "F8261" (manufactured by Evonik Japan Co., Ltd.), trade names "Modiper F206", "Modiper F246", "Modiper F606", "Modiper F730", "Modiper F3636" (all manufactured by NOF Corporation), trade name "8FS-001", "8FS-009" (all manufactured by Taisei Fine Chemical Co., Ltd.), trade name "Fluorosurf FS-7031", "Fluorosurf FS-7032" (all manufactured by Fluorotechnology Co., Ltd.), trade name "F-Clear" KD3510UV", "F-CLEAR KD3900UV", "F-CLEAR KD5010UV" (all manufactured by Kanto Denka Kogyo Co., Ltd.); Examples of such polymers include those with the trade names "Fluorolink A10P," "Fluorolink AD1700," "Fluorolink E10H," "Fluorolink F10," "Fluorolink MD700," "Fluorolink P54," "Fluorolink P56," "Fluorolink S10," "Fomblin M03," "Fomblin M07," "Fomblin M15," "Fomblin M30," "Fomblin M60," "Fomblin M100," "Fomblin W150," "Fomblin W500," "Fomblin W800," "Fomblin Y04," "Fomblin Y06," "Fomblin Y15," "Fomblin Y25," "Fomblin Y45," "Fomblin YU700," "Fomblin YR," "Fomblin YPL1500," "Fomblin YR1800," "Fomblin Z03," "Fomblin Z15," "Fomblin Z25," and "Fomblin Z60" (all manufactured by Solvay Specialty Polymers Japan, Ltd.).

[0082] The content of the leveling agent in the hard coat composition of the hard coat film of the present invention is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, and even more preferably 0.05 to 1 part by weight, relative to 100 parts by weight of the silsesquioxane compound. In the hard coat layer containing the leveling agent of the present invention, preferably 30% or more of the total amount of the leveling agent added is segregated within 100 nm of the surface of the hard coat layer, more preferably 50% or more is segregated within 100 nm of the surface of the hard coat layer, and even more preferably 80% or more is segregated within 100 nm of the surface of the hard coat layer. By segregating the leveling agent on the surface, the contact angle of the surface increases and the anti-fingerprint properties are improved.

[0083] <Reactive additives> The hard coat composition of the hard coat film of the present invention may further contain, as a reactive additive, a cationically curable compound other than the silsesquioxane compound of the present invention. As the reactive additive for photocationic polymerization, a compound having a cationically polymerizable functional group is used. Examples of the cationically polymerizable functional group of the reactive additive include an epoxy group, a vinyl ether group, an oxetanyl group, and an alkoxysilyl group. From the viewpoints of compatibility and reactivity with the silsesquioxane compound of the present invention, a compound having an epoxy group is preferred. From the viewpoints of a fast reaction rate and the surface hardness of the resulting cured product, a compound having a vinyl ether is preferred. From the viewpoint of a high final reaction rate, a compound having an oxetanyl group is preferred. In the hard coat composition of the present invention, the other cationically curable compounds as reactive additives may be used alone or in combination of two or more.

[0084] Specifically, examples of reactive additives having a glycidyl group include hydrogenated compounds of bisphenol A type epoxy compounds such as 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane and 2,2-bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]propane (hydrogenated bisphenol A type epoxy compounds); bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p ... Examples include hydrogenated compounds of bisphenol F epoxy compounds such as bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane (hydrogenated bisphenol F epoxy compounds); hydrogenated biphenol epoxy compounds; hydrogenated phenol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds of bisphenol A; hydrogenated naphthalene epoxy compounds; hydrogenated epoxy compounds of epoxy compounds obtained from trisphenolmethane; and hydrogenated epoxy compounds of the aromatic epoxy compounds listed below.

[0085] Examples of reactive additives for aromatic epoxy systems include epibis-type glycidyl ether epoxy resins obtained by the condensation reaction of bisphenols [e.g., bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc.] with epihalohydrin; high molecular weight epibis-type glycidyl ether epoxy resins obtained by further addition reaction of these epibis-type glycidyl ether epoxy resins with the above-mentioned bisphenols; phenols [e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol A]; Examples include novolak alkyl type glycidyl ether epoxy resins obtained by condensing polyhydric alcohols obtained by the condensation reaction of an aldehyde (e.g., formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde, etc.) with an epihalohydrin; and epoxy compounds in which two phenolic skeletons are bonded to the 9-position of the fluorene ring, and a glycidyl group is bonded to each of the oxygen atoms obtained by removing the hydrogen atom from the hydroxyl group of each of the phenolic skeletons, either directly or via an alkyleneoxy group.

[0086] Examples of aliphatic epoxy reactive additives include Denacol EX-121, Denacol EX-171, Denacol EX-192, Denacol EX-211, Denacol EX-212, Denacol EX-313, Denacol EX-314, Denacol EX-321, Denacol EX-411, Denacol EX-421, Denacol EX-512, Denacol EX-521, and Denacol E X-611, Denacol EX-612, Denacol EX-614, Denacol EX-622, Denacol EX-810, Denacol EX-811, Denacol EX-850, Denacol EX-851, Denacol EX-821, Denacol EX-830, Denacol EX-832, Denacol EX-841, Denacol EX-861, Denacol EX-911, Denacol EX-941 , Denacol EX-920, Denacol EX-931 (manufactured by Nagase ChemteX Corporation); Epolite M-1230, Epolite 40E, Epolite 100E, Epolite 200E, Epolite 400E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 1500NP, Epolite 1600, Epolite 80MF, Epolite 100MF (manufactured by Kyoeisha Chemical Co., Ltd.), Adeka Glycilor ED-503, Adeka Glycilor ED-503G, Adeka Glycilor ED-506, Adeka Glycilor ED-523T (manufactured by ADEKA Corporation), and acrylic rubbers having only epoxy groups as functional groups include Teisan Resin SG-P3, Teisan Resin SG-80H, and Teisan Resin SG-28GL (manufactured by Nagase ChemteX Corporation, epoxy group-containing acrylic rubbers).

[0087] Examples of reactive additives for alicyclic epoxy systems include 3,4,3',4'-diepoxybicyclohexane, 2,2-bis(3,4-epoxycyclohexyl)propane, 1,2-bis(3,4-epoxycyclohexyl)ethane, 2,3-bis(3,4-epoxycyclohexyl)oxirane, bis(3,4-epoxycyclohexylmethyl)ether, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (Daicel's "Celloxide 2021P"), ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel's "Celloxide 2081"), ε-caprolactone dimer-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel's "Celloxide 2083"), and JIANGSU TETRA NEW MATERIAL Examples of epoxy-modified cyclohexylmethyl acrylate include tetramethyl acrylate (manufactured by Daicel Chemical Industry under the trade name "TTA2083"), CELLOXIDE 2085 manufactured by DAICEL, bis(3,4-epoxycyclohexylmethyl)adipate (manufactured by JIANGSU TETRA NEW MATERIAL TECHNOLOGY under the trade name "TTA26"), 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol [for example, trade name "EHPE3150" manufactured by Daicel Corporation], (3,4-epoxycyclohexyl)methyl acrylate, (3,4-epoxycyclohexyl)methyl methacrylate, an epoxy-modified linear siloxane compound (manufactured by Shin-Etsu Chemical Industry under the trade name "X-40-2669"), and an epoxy-modified cyclic siloxane compound (manufactured by Shin-Etsu Chemical Industry under the trade name "KR-470").

[0088] The vinyl ether reactive additive is not particularly limited as long as it is a compound having one or more vinyl ether groups in the molecule, and examples thereof include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxyisopropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxybutyl vinyl ether, 3-hydroxyisobutyl vinyl ether, 2-hydroxyisobutyl vinyl ether, 2-ethylhexyl vinyl ether, 1-methyl-3-hydroxypropyl vinyl ether, 1-methyl-2-hydroxypropyl vinyl ether, 1-hydroxymethylpropyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, 1,6-hexanediol monovinyl ether, 1,6-hexanediol divinyl ether, 1,8-octanediol divinyl ether, 1,4-cyclohexanedimethanol monovinyl ether, 1,4-cyclohexanedimethanol divinyl ether, 1,3-cyclohexanedimethanol monovinyl ether, 1,3-cyclohexanedimethanol divinyl ether, 1,2-cyclohexanedimethanol monovinyl ether,2-Cyclohexanedimethanol divinyl ether, p-xylene glycol monovinyl ether, p-xylene glycol divinyl ether, m-xylene glycol monovinyl ether, m-xylene glycol divinyl ether, o-xylene glycol monovinyl ether, o-xylene glycol divinyl ether, ethylene glycol divinyl ether, diethylene glycol monovinyl ether, diethylene glycol divinyl ether, triethylene glycol monovinyl ether, triethylene glycol divinyl ether, tetraethylene glycol monovinyl ether, tetraethylene glycol divinyl ether, pentaethylene glycol monovinyl ether, pentaethylene glycol divinyl ether, oligoethylene glycol monovinyl ether, oligoethylene glycol divinyl ether, polyethylene glycol monovinyl ether, polyethylene glycol divinyl ether, dipropylene glycol monovinyl ether, dipropylene glycol divinyl ether, tripropylene glycol monovinyl ether Monovinyl ether, tripropylene glycol divinyl ether, tetrapropylene glycol monovinyl ether, tetrapropylene glycol divinyl ether, pentapropylene glycol monovinyl ether, pentapropylene glycol divinyl ether, oligopropylene glycol monovinyl ether, oligopropylene glycol divinyl ether, polypropylene glycol monovinyl ether, polypropylene glycol divinyl ether, isosorbide divinyl ether, oxanorbornene divinyl ether, phenyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octyl vinyl ether, cyclohexyl vinyl ether, hydroquinone divinyl ether, 1,4-butanediol divinyl ether, cyclohexanedimethanol divinyl ether, trimethylolpropane divinyl ether, trimethylolpropane trivinyl ether, bisphenol A divinyl ether, bisphenol F divinyl ether, hydroxyoxanorbornanemethanol divinyl ether, 1,Examples include 4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, and dipentaerythritol hexavinyl ether. Among these, the use of a compound having both a hydroxy group and a vinyl ether group in one molecule can improve the reaction rate and surface hardness without impairing flex resistance.

[0089] The oxetane-based reactive additive is not particularly limited as long as it is a compound having one or more oxetanyl groups in the molecule. Examples thereof include 3,3-bis(vinyloxymethyl)oxetane, 3-ethyl-3-(hydroxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-[(phenoxy)methyl]oxetane, 3-ethyl-3-(hexyloxymethyl)oxetane, 3-ethyl-3-(chloromethyl)oxetane, 3,3-bis(chloromethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, bis{[1-ethyl ethyl(3-oxetanyl)]methyl} ether, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene, 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl)}oxetane, xylylene bisoxetane, 3-ethyl-3-{[3-(triethoxysilyl)propoxy]methyl}oxetane, oxetanyl silsesquioxane, and phenol novolac oxetane.

[0090] The content of the reactive additive in the hard coat composition of the hard coat film of the present invention is preferably 150 parts by weight or less, more preferably 100 parts by weight or less, and even more preferably 50 parts by weight or less, relative to 100 parts by weight of the silsesquioxane compound.

[0091] <Photosensitizer> In the hard coat composition of the hard coat film of the present invention, a photosensitizer may be used for the purpose of improving the photosensitivity of the photoacid generator. As the photosensitizer, either a type that improves the photosensitivity of the photoacid generator by absorbing light in a wavelength range that cannot be absorbed by the photoacid generator used, or a type that improves the photosensitivity of the photoacid generator while having a wavelength range that is not significantly different from that of the photoacid generator, may be used. When using a type that absorbs light in a wavelength range that cannot be absorbed by the photoacid generator used, it is preferable that the photosensitizer has strong absorption in a wavelength range different from the absorption wavelength range of the photoacid generator.

[0092] The photosensitizer is not particularly limited, but examples thereof include anthracene derivatives, benzophenone derivatives, thioxanthone derivatives, anthraquinone derivatives, benzoyl derivatives, and naphthalene derivatives. Specifically, anthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-dimethylanthracene, 9,10-dibutoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diethoxyanthracene, 1,4-dimethoxyanthracene, 9-methylanthracene, 2-ethylanthracene, 2-tert-butylanthracene, 2,6-di-tert-butylanthracene, 9,10-diphenyl-2,6-di-tert-butylanthracene, 9,10-bis(isopropoxycarbonylmethoxy)anthracene, 9,10-dioctanoyloxyanthracene, 1,4-diethoxynaphthalene, 1,4-dimethoxynaphthalene, 1,4-dipropoxynaphthalene, 1,4-dibutoxynaphthalene, benzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone , 4-benzoyl-4'-methyldiphenyl sulfide, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, thioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 3-acetylcoumarin, 3-acetyl-7-diethylaminocoumarin, 3-benzoylcoumarin, 3-benzoyl-7-diethylaminocoumarin, 3-benzoyl-7-methoxycoumarin, 3,3'-carbonylbiscoumarin, 3,3'-carbonylbis(7-methoxycoumarin), 3,3'-carbonylbis(5,7-dimethoxycoumarin), and the like.

[0093] The content of the photosensitizer in the hard coat composition of the hard coat film of the present invention is preferably 500 parts by weight or less, more preferably 100 parts by weight or less, and even more preferably 50 parts by weight or less, per 100 parts by weight of the photoacid generator.

[0094] <particle> The hard coat composition of the hard coat film of the present invention may contain particles for the purpose of adjusting film properties (surface hardness and flex resistance) and suppressing cure shrinkage. The particles may be appropriately selected from organic particles, inorganic particles, organic-inorganic composite particles, etc. Examples of organic particle materials include poly(meth)acrylic acid alkyl esters, crosslinked poly(meth)acrylic acid alkyl esters, crosslinked styrene, nylon, silicone, crosslinked silicone, crosslinked urethane, and crosslinked butadiene. Examples of inorganic particle materials include metal oxides such as silica, titania, alumina, tin oxide, zirconia, zinc oxide, and antimony oxide; metal nitrides such as silicon nitride and boron nitride; and metal salts such as calcium carbonate, calcium hydrogen phosphate, calcium phosphate, and aluminum phosphate. Examples of organic-inorganic composite fillers include organic particles having an inorganic layer formed on the surface thereof, and inorganic particles having an organic layer or organic fine particles formed on the surface thereof.

[0095] Examples of the particle shape include spherical, powdery, fibrous, needle-like, scale-like, etc. Spherical particles are not anisotropic and are less likely to cause uneven distribution of stress, which can suppress the occurrence of distortion and contribute to suppressing warping of the film due to curing shrinkage, etc.

[0096] The average particle size of the particles is, for example, about 5 nm to 10 μm. From the viewpoint of increasing the transparency of the hard coat layer, the average particle size is preferably 1000 nm or less, more preferably 500 nm or less, even more preferably 300 nm or less, and particularly preferably 100 nm or less. The particle size can be measured using a laser diffraction / scattering particle size distribution measuring device, and the volume-based median size is taken as the average particle size.

[0097] The hard coat composition may contain surface-modified particles. By surface-modifying the particles, the dispersibility of the particles in the siloxane compound tends to be improved. In addition, when the particle surface is modified with a polymerizable functional group that can react with an epoxy group, the functional group on the particle surface reacts with the epoxy group of the silsesquioxane compound of the present invention to form a chemical crosslink, and therefore, improvement in film strength and flex resistance can be expected.

[0098] Examples of polymerizable functional groups that can react with epoxy groups include vinyl groups, (meth)acrylic groups, hydroxyl groups, phenolic hydroxyl groups, carboxyl groups, acid anhydride groups, amino groups, epoxy groups, and oxetane groups. Among these, epoxy groups are preferred. In particular, particles surface-modified with epoxy groups are preferred because they can form chemical crosslinks between the particles and the siloxane compound when the hard coat composition is cured by photocationic polymerization.

[0099] Examples of particles having reactive functional groups on their surfaces include surface-modified inorganic particles and core-shell polymer particles. These particles may be used alone or in combination.

[0100] <Solvent> The hard coat composition of the hard coat film of the present invention may or may not contain a solvent. When a solvent is contained, it is preferable that the solvent does not dissolve the resin substrate. The content of the solvent is preferably 500 parts by weight or less, more preferably 300 parts by weight or less, and even more preferably 100 parts by weight or less, relative to 100 parts by weight of the silsesquioxane compound of the present invention.

[0101] <Additives> The hard coat composition of the hard coat film of the present invention may contain additives such as inorganic pigments, organic pigments, radical polymerization initiators, surface conditioners, surface modifiers, plasticizers, dispersants, wetting agents, thickeners, antifoaming agents, etc. The hard coat composition may also contain a thermoplastic or thermosetting resin material other than the above-mentioned silsesquioxane compound.

[0102] [Hard coat film] The hard coat film of the present invention is characterized by having a transparent resin film layer and a hard coat layer which is a cured product of a condensate composition containing a silane compound having an alicyclic epoxy group in the molecule, represented by general formula (1), formed on at least one surface of the transparent resin film layer.

[0103] The hard coat layer in the hard coat film of the present invention may be formed on only one surface (one side) of the transparent resin film layer, or on both surfaces (both sides).

[0104] The hard coat film of the present invention can be obtained by applying a hard coat composition to a transparent resin film layer, optionally drying and removing the solvent, and then curing the hard coat composition by irradiating with active energy rays or by heating. Among these, a method including a step of applying a composition containing a silane compound condensate and a photocationic initiator to a transparent resin film, followed by a step of irradiating with active energy rays, is preferred from the viewpoint of productivity. The method for applying the hard coat composition is not particularly limited, and existing coating methods such as roll coating (e.g., bar coating, gravure coating, comma coating), die coating (e.g., slot die coating, fountain die coating), spin coating, spray coating, and dip coating can be used.

[0105] Before applying the hard coat layer, the surface of the transparent resin film layer serving as the substrate may be subjected to a surface treatment such as corona treatment or plasma treatment. Corona treatment or plasma treatment improves the adhesion between the transparent resin film layer and the hard coat layer, thereby improving flex resistance. Furthermore, an easy-adhesion layer (primer layer) or the like may be provided on the surface of the transparent resin film layer. Since the hard coat layer of the present invention exhibits high adhesion to the transparent resin film layer, it is not necessary to provide an easy-adhesion layer or the like. That is, in the hard coat film of the present invention, the transparent resin film layer and the hard coat layer may be in contact with each other.

[0106] By irradiating the hard coat composition with active energy rays or by heating, an acid is generated from the cationic polymerization initiator, and the epoxy group of the silsesquioxane compound undergoes ring-opening and cationic polymerization, thereby proceeding with curing.When the hard coat composition contains a reactive additive, in addition to the polymerization reaction between siloxane compounds, the polymerization reaction between the epoxy group of the siloxane compound and the reactive additive also occurs.In addition, when the hard coat composition contains particles having reactive functional groups on their surfaces, the functional groups on the particle surface react with the epoxy group of the siloxane compound to form chemical crosslinks.

[0107] Examples of active energy rays irradiated during photocuring include visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, γ-rays, and electron beams. Ultraviolet light is preferred as the active energy ray because it has a high curing reaction rate and excellent energy efficiency. The cumulative irradiation dose of the active energy ray is, for example, 50 to 10,000 mJ / cm. 2 The curing temperature is about 150° C., and may be set depending on the type and amount of the photocationic polymerization initiator, the thickness of the hard coat layer, etc. The curing temperature is not particularly limited, but is usually 150° C. or lower.

[0108] As described above, during curing, an acid is generated from the cationic polymerization initiator (photoacid generator), and photocuring proceeds. Therefore, counter anions of the photoacid generator remain in the hard coat layer after curing. The hard coat layer may contain a fluorophosphate-based anion, a tetrakispentafluorophenylborate-based anion, a fluorogallium-based anion, or a salt thereof as the counter anion of the photoacid generator.

[0109] The transparent resin film layer in the hard coat film of the present invention preferably has a retardation of 0 to 20 nm. If the retardation exceeds this range, it is undesirable because it tends to cause a decrease in visibility when viewed through a polarizer such as polarized sunglasses when incorporated into a display.

[0110] The transparent resin film layer is not particularly limited, and examples thereof include substrates made of resin materials such as polycarbonate (PC), cyclic polyolefins, (meth)acrylic resins such as polymethyl methacrylate (PMMA), and cellulose-based resins such as triacetyl cellulose (TAC). Here, the term "(meth)acrylic resin" refers to polymers and copolymers of methacrylate and acrylate, including poly(meth)acrylic acid esters such as polymethyl methacrylate (PMMA), methyl methacrylate-(meth)acrylic acid copolymers, methyl methacrylate-(meth)acrylic acid ester copolymers, methyl methacrylate-acrylic acid ester-(meth)acrylic acid copolymers, and methyl (meth)acrylate-styrene copolymers. Furthermore, all or part of the (meth)acrylic acid structures in methacrylate and acrylate polymers and copolymers may be modified with acid anhydride structures or imide ring structures.

[0111] The resin constituting the resin substrate may be composed of one type of monomer or two or more types of monomers, and can be appropriately adjusted within a range that satisfies the characteristics of the hard coat film of the present invention. The resin may contain 0 to 49 wt%, more preferably 0 to 20 wt%, and even more preferably 0 to 5 wt% of a monomer classified as another resin. The resin substrate may be composed of only one type of resin material, or two or more types of resin materials. It may also be a laminate thereof.

[0112] From the viewpoint of the fold recovery property when a hard coat layer is formed, the transparent resin film layer is more preferably a (meth)acrylic resin such as polymethyl methacrylate (PMMA) or polycarbonate (PC). From the viewpoint of the hardness when a hard coat layer is formed, a (meth)acrylic resin such as polymethyl methacrylate (PMMA) or a cellulose-based resin such as triacetyl cellulose (TAC) is more preferred. From the viewpoint of the balance between the fold recovery property and hardness, a (meth)acrylic resin such as polymethyl methacrylate (PMMA) is particularly preferred.

[0113] The transparent resin film layer may be a single-layer structure or a multi-layer structure, and its structure is not particularly limited.For example, the transparent resin film layer may be a transparent resin film layer having a laminated structure in which a layer other than the hard coat layer of the present invention is formed on at least one surface.Examples of the layer other than the hard coat layer of the present invention include hard coat layers other than the hard coat layer of the present invention.

[0114] The thickness of the transparent resin film layer is 20 to 80 μm. It can be appropriately selected from this range, and is preferably 20 to 70 μm, more preferably 20 to 60 μm, even more preferably 20 to 50 μm, and particularly preferably 30 to 45 μm. When the transparent resin film layer is thick, the hardness tends to be good, and when it is thinner than 20 μm, the hardness is insufficient. When the transparent resin film layer is thin, the fold recovery property and flex resistance tend to be good, and when it is thicker than 80 μm, the fold recovery property and flex resistance are insufficient.

[0115] The thickness of the hard coat layer of the present invention is 3 to 49 μm. It can be appropriately selected from this range, preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, preferably 48 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 25 μm or less. A thick hard coat layer tends to improve fold recovery, hardness, and impact resistance, while a thickness of less than 3 μm may result in insufficient fold recovery, hardness, and impact resistance. Here, impact resistance refers to resistance to impact applied to a display when the hard coat film of the present invention is incorporated into the display, and a thick hard coat layer improves impact resistance. A thin hard coat layer tends to improve flex resistance, while a thickness of more than 49 μm results in insufficient flex resistance. Furthermore, a hard coat layer thicker than 49 μm may also result in reduced fold recovery.

[0116] The total thickness of the hard coat film of the present invention can be appropriately selected from the range of 23 to 129 μm, and is preferably 55 to 100 μm. If the total thickness is less than 23 μm, the hardness may be insufficient. If the total thickness exceeds 129 μm, the flex resistance may be insufficient.

[0117] In the hard coat film of the present invention, the ratio of the thickness of the hard coat layer to the thickness of the transparent resin film layer (thickness of hard coat layer / thickness of transparent resin film layer) is not particularly limited and may be appropriately selected, for example, from between 49 / 20 and 3 / 80.

[0118] [Hard coat film characteristics] The hard-coated film of the present invention is characterized by a low retardation, resulting in excellent visibility when used in a display. In the hard-coated film of the present invention, both the hard-coat layer and the transparent resin film layer are controlled to have a low retardation, and the polarization state of light emitted from the display is hardly changed. This prevents discoloration of the image or changes in the amount of light when the display is viewed through a polarizer, resulting in the advantageous effect of obtaining good image quality. The front retardation of the hard-coated film of the present invention is 0 to 20 nm, preferably 0 to 10 nm, more preferably 0 to 5 nm, and even more preferably 0 to 3 nm. When the hard-coated film of the present invention is placed between linear polarizing plates arranged in parallel, it is preferable that rainbow unevenness due to discoloration of the image and changes in the amount of light does not occur.

[0119] The hard-coated film of the present invention is characterized by having a low retardation as described above and excellent fold recovery. The fold recovery is defined as the angle obtained by measuring the included angle at the folded portion of the hard-coated film after holding it in a 60°C, 90% RH environment in a folded state with a radius of 3 mm for 24 hours, removing the bending load, and holding it in a 23°C, 50% RH environment for 20 minutes. Flexible displays, such as foldable displays and rollable displays, are held in a folded or wound state when not in use, but are often used in a shape close to flat. Therefore, fold recovery is highly required, which is the property of eliminating deformation when held in a folded or wound state when returned to a flat state. However, transparent resin films with low retardation do not necessarily have high fold recovery, and have often exhibited insufficient fold recovery when used in flexible displays. The hard coat film of the present invention has a hard coat layer, which is a cured product of a condensate composition containing a silane compound represented by general formula (1) having an alicyclic epoxy group in the molecule. The hard coat layer has three-dimensional siloxane bonds resulting from the condensation of the silane compound and ether bonds resulting from the curing reaction of the epoxy group, and is highly crosslinked. This makes the hard coat layer less susceptible to creep when subjected to a bending load, and provides excellent fold recovery. This makes it possible to significantly improve the fold recovery of a transparent resin film layer having this hard coat layer. The fold recovery tends to improve with a thicker hard coat layer. The fold recovery angle of the hard coat film of the present invention is 70 to 180°, preferably 90 to 180°, and more preferably 130 to 180°. Because the hard coat film of the present invention has high fold recovery, it can also be used for components of flexible displays that do not necessarily require high hardness, other than the outermost layer of a cover window.

[0120] The hard-coated film of the present invention can significantly improve its fold recovery property by laminating a hard-coat layer to a transparent resin film layer. The ratio of the fold recovery angle of the hard-coated film after forming a hard-coat layer on the transparent resin film layer to the fold recovery angle of the transparent resin film layer alone, defined as the fold recovery angle of the hard-coated film on which a hard-coat layer is formed, to the fold recovery angle of the transparent resin film layer alone without the hard-coat layer, is preferably 1.20 or more, more preferably 5.0 or more, and even more preferably 24.00 or more. A large ratio of the fold recovery angle of the hard-coated film after forming a hard-coat layer on the transparent resin film layer to the fold recovery angle of the transparent resin film layer alone means that the hard-coat layer has a significant effect in improving the fold recovery angle.

[0121] The hard coat film of the present invention preferably has a total light transmittance of 90% or more. A high total light transmittance can improve the visibility of a display and reduce power consumption. A total light transmittance of 91% or more is more preferable, and 92% or more is even more preferable.

[0122] The hard coat film of the present invention preferably has a YI of 2.0 or less. A low YI can improve the visibility of the display and improve the color tone. A YI of 1.5 or less is more preferable.

[0123] The hard coat film of the present invention has a hard coat layer, which is a cured product of a condensate composition containing a silane compound having an alicyclic epoxy group in the molecule, represented by general formula (1), and has excellent flex resistance because the presence of the epoxy group improves adhesion to the transparent resin film layer, making it less likely to peel from the transparent resin film layer when bent.The hard coat film of the present invention is preferably capable of being bent to a radius of 1 mm or less in a mandrel flex test in accordance with JIS-K5600, with the hard coat layer facing inner.

[0124] The hard coat film of the present invention, with the hard coat layer facing outward, can be bent preferably to a radius of 5 mm or less in a mandrel bending test in accordance with JIS-K5600, more preferably to a radius of 2.0 mm or less, and particularly preferably to a radius of 1.5 mm or less.

[0125] The hard coat film of the present invention can be repeatedly bent preferably at a radius of 2.5 mm with the hard coat layer facing inward at 50,000 times or more, and more preferably at least 100,000 times.

[0126] The hard coat film of the present invention preferably has a hardness of 6B or more in a pencil hardness test in accordance with JIS-K 5600. The pencil hardness is more preferably 3B or more, even more preferably HB or more, particularly preferably H or more, and most preferably 3H or more.

[0127] [Applications of hard coated films] The hard coat film may have various functional layers on the hard coat layer or on the surface of the transparent resin film layer where the hard coat layer is not formed. Examples of functional layers include an antireflection layer, an antiglare layer, an antistatic layer, and a transparent electrode. The hard coat film may also have a transparent pressure-sensitive adhesive layer attached thereto.

[0128] The hard-coated film of the present invention has high transparency and excellent mechanical strength, and therefore can be suitably used as a cover window provided on the surface of an image display panel, a transparent substrate for a display, a transparent substrate for a touch panel, a substrate for a solar cell, etc. The hard-coated film of the present invention further has a low retardation and particularly excellent fold recovery, and therefore can be suitably used particularly as a cover window or substrate film for a curved display, a flexible display, etc. The hard-coated film of the present invention has excellent fold recovery compared to a low-retardation transparent resin film alone, which has traditionally been difficult to use in flexible displays due to insufficient fold recovery, and enables the application of low-retardation films to flexible displays.

Example

[0129] Hereinafter, based on Examples and Comparative Examples, the present invention will be described more specifically, but the present invention is not limited to the following Examples. The evaluation method of the condensate obtained in the following Synthesis Examples is as follows.

[0130] <Measurement of number average molecular weight Mn> The number average molecular weight was measured by GPC. Using a GPC device HLC-8220GPC manufactured by Tosoh Corporation (columns: TSKgel GMHXL × 2, TSKgel G3000HXL, TSKgel G2000HXL), THF was used as the solvent, and it was calculated in terms of polystyrene.

[0131] <Calculation of the ratio of T3 form to T2 form [T3 form] / [T2 form]> Using a 600MHz-NMR manufactured by Agilent Technologies 29 By performing Si-NMR measurement, the contents of the T3 form and the T2 form and their ratio [T3 form] / [T2 form] were calculated respectively.

[0132] <Evaluation of the residual rate of epoxy groups> Using a 400MHz-NMR manufactured by Bruker, with deuterated acetone as the solvent 1 By performing 1H-NMR measurement, the remaining amount of epoxy groups in the condensate obtained after the reaction was calculated.

[0133] [Synthesis of silsesquioxane compound (condensate of silane compound)] (Synthesis Example 1) A 200 mL flask reaction vessel equipped with a thermometer, stirrer, and reflux condenser was charged with 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (SILQUEST A-186, Momentive Performance Materials) (66.5 g; 270 mmol) and 1-methoxy-2-propanol (PGME) (16.5 g) and stirred until homogeneous. A solution of magnesium chloride (0.039 g; 0.405 mmol) dissolved in a mixture of water (9.7 g; 539 mmol) and methanol (5.8 g) was added dropwise to the mixture over 5 minutes and stirred until homogeneous. The mixture was then heated to 80°C and stirred for 6 hours. After completion of the reaction, the mixture was devolatilized and concentrated under reduced pressure using a rotary evaporator to remove the methanol and water from the condensate. Analysis of the resulting condensate revealed that it had a number average molecular weight Mn of 1,700, 29 The ratio of T3 to T2 isomers [T3 isomer] / [T2 isomer] calculated by Si-NMR measurement was 2.3. The content of magnesium chloride (neutral salt catalyst) calculated based on the above-mentioned charged weight was 814 ppm.

[0134] [Preparation of transparent polyimide film 1] (Preparation of Polyamic Acid Solution 1) A separable flask was charged with 2,2'-bis(trifluoromethyl)benzidine (4.48 g; 14.0 mmol), 3,3'-diaminodiphenyl sulfone (1.49 g; 6.0 mmol), and N,N-dimethylformamide (DMF) (64.6 g) and stirred under a nitrogen atmosphere to obtain a diamine solution. To this solution, p-phenylenebis(trimellitic acid monoester anhydride) (2.29 g; 5.0 mmol), 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropanoic dianhydride (4.44 g; 10.0 mmol), and 3,3',4,4'-biphenyltetracarboxylic dianhydride (1.47 g; 5.0 mmol) were added and stirred for 12 hours to obtain polyamic acid solution 1.

[0135] (Imidization and isolation of polyimide resin) To the polyamic acid solution 1, 28.9 g of DMF and pyridine (4.75 g; 60.0 mmol) as an imidization catalyst were added and completely dispersed. After that, acetic anhydride (6.13 g; 60.0 mmol) was added and stirred at 80°C for 4 hours. The solution was cooled to room temperature, and while stirring, 400 g of 2-propyl alcohol (IPA) was added. After stirring for approximately 30 minutes, the mixture was suction filtered using a Kiriyama funnel. The resulting solid was washed with 100 g of IPA. This washing process was repeated six times, and then the mixture was dried in a vacuum oven set at 120°C for 8 hours to obtain polyimide resin 1.

[0136] (Preparation of transparent polyimide film 1) The polyimide resin 1 was dissolved in dichloromethane to obtain a polyimide solution with a solids concentration of 10% by weight. The polyimide solution was applied to a non-alkali glass plate using a bar coater and heated in air at 40°C for 60 minutes, 80°C for 30 minutes, 150°C for 30 minutes, and 170°C for 30 minutes to remove the solvent, yielding a transparent polyimide film 1 with a thickness of 50 μm.

[0137] [Preparation of transparent polyimide film 2] (Preparation of Polyamic Acid Solution 2) A reaction vessel was charged with 383 parts by weight of N,N-dimethylformamide (DMF) and stirred under a nitrogen atmosphere. 36.3 parts by weight of 2,2'-bis(trifluoromethyl)benzidine, 12.0 parts by weight of 3,3'-diaminodiphenyl sulfone, 15.8 parts by weight of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 35.9 parts by weight of 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride were sequentially added and stirred under a nitrogen atmosphere to obtain polyamic acid solution 2.

[0138] (Imidization and isolation of polyimide resin) To polyimide acid solution 2 (100 parts by weight of polyamic acid solids), 38.4 parts by weight of pyridine was added as an imidization catalyst. After stirring, 49.5 parts by weight of acetic anhydride was added. The mixture was stirred at 120°C for 2 hours and then cooled to room temperature to obtain a polyimide solution. While stirring the solution, 1 L of isopropyl alcohol was added dropwise to precipitate a polyimide resin. The filtered polyimide resin was then washed three times with IPA and dried at 120°C for 12 hours to obtain a white polyimide resin 2.

[0139] (Preparation of transparent polyimide film 2) Polyimide resin 2 was dissolved in methyl ethyl ketone to obtain a polyimide solution with a solids concentration of 17%. The polyimide solution was applied to a non-alkali glass plate using a coater and dried in the air at 40°C for 10 minutes, 80°C for 30 minutes, 150°C for 30 minutes, and 170°C for 1 hour. The film was then peeled off from the non-alkali glass plate to obtain a transparent polyimide film 2 with a thickness of 80 μm.

[0140] The method for preparing the hard coat composition and the method for producing the hard coat film are as follows.

[0141] [Preparation of hard coat composition and production of hard coat film] (Example 1: Preparation of hard coat film 1) Hard coat composition 1 was obtained by blending 100 parts by weight of the silsesquioxane compound obtained in Synthesis Example 1 with 2 parts by weight (solids) of a 50% propylene carbonate solution of diphenyl(4-phenylthiophenyl)·SbF6 salt (manufactured by San-Apro Co., Ltd.: CPI-101A) as a photocationic polymerization initiator and 0.25 parts by weight (solids) of a silicone-based leveling agent (manufactured by BYK-Chemie Japan Co., Ltd.: BYK-300) as a leveling agent.

[0142] Hard coat composition 1 was applied to the main surface of a 40 μm-thick polymethyl methacrylate film used as a transparent resin film layer using a bar coater so that the dry film thickness would be 20 μm, and the coating was heated for 10 minutes at 120° C. After that, the coating was gradually cooled to 60° C., and then ultraviolet light was irradiated using a high-pressure mercury lamp so that the integrated UVA light intensity was 400 mJ / cm2, curing the hard coat composition and obtaining hard coat film 1.

[0143] Example 2 A hard coat film 2 was obtained in the same manner as in Example 1, except that a triacetyl cellulose film having a thickness of 40 μm was used as the transparent resin film layer.

[0144] Example 3 Hard coat film 3 was obtained in the same manner as in Example 1, except that a triacetyl cellulose film having a thickness of 60 μm was used as the transparent resin film layer.

[0145] Example 4 Hard coat film 4 was obtained in the same manner as in Example 1, except that a triacetyl cellulose film having a thickness of 80 μm was used as the transparent resin film layer.

[0146] Example 5 Hard coat film 5 was obtained in the same manner as in Example 1, except that a polycarbonate film having a thickness of 45 μm was used as the transparent resin film layer.

[0147] Example 6 A hard coat film 6 was obtained in the same manner as in Example 1, except that a polycarbonate film having a thickness of 66 μm was used as the transparent resin film layer.

[0148] Example 7 Hard coat film 7 was obtained in the same manner as in Example 1, except that the dry film thickness of hard coat composition 1 was adjusted to 10 μm.

[0149] Example 8 A hard coat film 8 was obtained in the same manner as in Example 1, except that the dry film thickness of the hard coat composition 1 was adjusted to 5 μm.

[0150] (Comparative Example 1) A hard coat film 9 was obtained in the same manner as in Example 1, except that a transparent polyimide film 1 having a thickness of 50 μm was used as the transparent resin film layer.

[0151] (Comparative Example 2) A hard coat film 10 was obtained in the same manner as in Example 1, except that a transparent polyimide film 2 having a thickness of 80 μm was used as the transparent resin film layer.

[0152] (Comparative Example 3) A hard coat film 11 was obtained in the same manner as in Example 1, except that a polyethylene naphthalate film having a thickness of 50 μm was used as the transparent resin film layer.

[0153] Comparative Example 4 A hard coat film 12 was obtained in the same manner as in Example 1, except that a polyethylene terephthalate film having a thickness of 50 μm was used as the transparent resin film layer.

[0154] (Comparative Example 5) A hard coat film 13 was obtained in the same manner as in Example 1, except that a polyethylene terephthalate film having a thickness of 125 μm was used as the transparent resin film layer.

[0155] (Comparative Example 6) A hard coat film 14 was obtained in the same manner as in Example 1, except that a polymethyl methacrylate film having a thickness of 160 μm was used as the transparent resin film layer.

[0156] The physical properties of the hard coat films obtained in the examples and comparative examples were evaluated as follows: The evaluation results of each example and comparative example are shown in Tables 1 and 2.

[0157] <Bending recovery (bending recovery angle)> A hard-coated film or a transparent resin film layer without a hard-coated layer was bent to a radius of 3 mm and held in a 60°C, 90% RH environment for 24 hours. After the bending load was removed and the film was held in a 23°C, 50% RH environment for 20 minutes, the included angle at the bent portion of the film was measured and used as the folding recovery angle. A larger value indicates higher folding recovery. For hard-coated films, the test was performed by folding the film with the hard-coated layer facing inward.

[0158] <Bending recovery (bending recovery angle ratio)> The recovery angle of the hard-coat film having a hard-coat layer formed thereon was divided by the recovery angle of the transparent resin film layer alone without a hard-coat layer formed thereon, and the larger this value, the greater the effect of improving the recovery of the hard-coat layer.

[0159] <Flexibility (cylindrical mandrel (radius))> In accordance with JIS K5600, a cylindrical mandrel test was carried out using a Type 1 testing machine with the hard coat layer formed on the resin substrate facing outward. A smaller mandrel diameter indicates better flex resistance.

[0160] <Flexibility (repeated bending test (radius))> The hard-coated film was placed in a Yuasa System DMLHB U-shaped bending durability tester and repeatedly bent at a bending radius of 2.5 mm at a rate of 1 bend / second, and the presence or absence of cracks or breaks was confirmed after the specified number of bends. The test was conducted in a constant temperature and humidity environment set at 23°C and 55% humidity. If there are no cracks or breaks even after many repeated bends, it indicates excellent bending resistance. If there are no cracks or breaks after 100,000 repeated bends, it is stated as having a durability of over 100,000 bends. The test was conducted with the hard-coated layer bent inward.

[0161] <Surface hardness (pencil hardness)> According to JIS K5600, the pencil hardness of the surface on which the hard coat layer was formed was measured under a load of 750 g to evaluate the surface hardness.

[0162] <Rainbow unevenness> A hard coat film and a linear polarizer were laminated in that order on a liquid crystal display, and the presence or absence of color unevenness was checked on a white screen. Those with color unevenness were marked with an X, and those without color unevenness were marked with an O. The polarizer of the liquid crystal display and the linear polarizer on the hard coat film were positioned so that their optical axes were aligned. The absence of color unevenness indicates excellent visibility.

[0163] <(Front) phase difference> The retardation of the hard coat film was measured using a retardation measuring device OPTIPRO (MODEL 21-255MA) manufactured by Syntec Co., Ltd. The smaller the retardation value, the better the visibility.

[0164] <Total light transmittance and haze> Measurements were made using a haze meter HZ-V3 manufactured by Suga Test Instruments according to the methods described in JIS K7361-1: 1999 and JIS K7136: 2000. The measurement was made using a D65 light source, and the total light transmittance was calculated as the ratio of the total transmitted light flux (parallel light component and diffuse light component) to the parallel incident light flux on the film.

[0165] <yi> Measurements were taken in transmission mode using a Suga Test Instruments colorimeter SC-P. A D65 light source was used for measurements. The closer the YI is to 0, the better the colorlessness. [Table 1] [Table 2] In the table, the materials of the transparent resin film layer are indicated by the following abbreviations: Polymethyl methacrylate: PMMA Triacetyl cellulose: TAC Polycarbonate: PC Polyimide: PI Polyethylene naphthalate: PEN Polyethylene terephthalate: PET

[0166] The hard-coated films of Examples 1 to 8 have excellent optical properties due to low retardation and no rainbow unevenness, and also have significantly better fold recovery properties than transparent resin films alone. Therefore, they can be suitably used as cover windows or substrates for flexible displays. Focusing on the thickness of the hard-coat layer, Example 1, which has a thick hard-coat layer, had the best fold recovery properties, and a tendency was observed in which the fold recovery properties decreased as the hard-coat layer became thinner.

[0167] The hard coat films of Comparative Examples 1 to 5 had a large retardation and rainbow unevenness, which may cause visibility problems when used in a display. Furthermore, a comparison of Comparative Examples 4 and 5 shows that if the transparent resin film layer is too thick, the fold recovery property tends to deteriorate. The hard coat film of Comparative Example 6 had a low retardation and no rainbow unevenness, so the optical properties were good. However, the transparent resin film layer was too thick, so the hard coat film broke during the fold recovery test, and the flex resistance was inferior to that of the Examples.< / yi>

Claims

1. A hard coat film having a transparent resin film layer and a hard coat layer, On at least one surface of a transparent resin film layer having a thickness of 20 to 80 μm, a hard coat layer having a thickness of 3 to 49 μm, which is a cured product of a condensation product composition containing a silane compound having an alicyclic epoxy group in the molecule, represented by the following general formula (1): the transparent resin film is a (meth)acrylic resin film, The front retardation is 0 to 20 nm, A hard coat film characterized in that the recovery angle after bending is 70 to 180° when measured after being bent at a radius of 3 mm for 24 hours in an environment of 60°C and 90% RH and then the load is removed. (In the formula (1), R １ is a group containing an alicyclic epoxy group, and R ２ is a hydrogen atom or an alkyl group, and R ３ is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and x is an integer of 1 to 3. 【Chemical 1】

2. 2. The hard coat film according to claim 1, wherein the ratio of the folding recovery angle of the hard coat film after forming the hard coat layer on the transparent resin film layer to the folding recovery angle of the transparent resin film layer alone is 1.20 or more.

3. The hard coat film has a hard coat layer which is a cured product of a condensation product composition containing a silane compound represented by general formula (2) in addition to a silane compound having an alicyclic epoxy group in the molecule, The hard coat film according to claim 1 or 2, characterized in that the ratio of [structural unit represented by general formula (1)] / ([structural unit represented by general formula (1)]+[structural unit represented by general formula (2)]) of the condensate is 0.5 or more and 1.0 or less. (However, the silane compound represented by general formula (2) is a silane compound different from the silane compound represented by general formula (1), and R in general formula (2) ４ does not contain an alicyclic epoxy group, and is a group containing a substituted or unsubstituted double bond, a group containing a substituted or unsubstituted cycloalkyl group, a group containing a substituted or unsubstituted aromatic ring, a substituted or unsubstituted alkyl group, a group containing a glycidyl group, a group containing an oxetanyl group, or a hydrogen atom. 【Chemistry 2】

4. The hard coat film according to any one of claims 1 to 3, characterized in that the molar ratio of the structural unit represented by the following formula (3) to the structural unit represented by the following formula (4) contained in the condensate of the silane compound [structural unit represented by formula (3)] / [structural unit represented by formula (4)] is 0.8 or more and less than 5. (In formula (3), R a is R 1 in formula (1) and R ４ In formula (4), R ａ represents R 1 in formula (1) and R ４ and Z is a hydroxyl group or an alkoxy group having an alkyl group. 【Chemistry 3】 【Chemistry 4】

5. 5. The hard coat film according to claim 1, wherein the total light transmittance is 90% or more.

6. 6. The hard coat film according to claim 1, wherein the YI value is 2.0 or less.

7. 7. The hard coat film according to claim 1, which can be bent with a radius of 1 mm or less in a mandrel bending test in accordance with JIS-K5600 with the hard coat layer facing inner surface.

8. 8. The hard coat film according to claim 1, which can be bent with the hard coat layer facing outward at a radius of 5 mm or less in a mandrel bending test in accordance with JIS-K5600.

9. 9. The hard coat film according to claim 1, which can be repeatedly bent at a radius of 2.5 mm 50,000 times or more.

10. 10. The hard coat film according to claim 1, which has a hardness of 6B or more in a pencil hardness test in accordance with JIS-K5600.

11. 11. The hard coat film according to claim 1, wherein when the hard coat film is placed between two linear polarizing plates whose optical axes are parallel, rainbow unevenness does not occur in transmitted light from a white light source.

12. 12. A method for producing a hard coat film according to claim 1, characterized in that after a step of applying a composition containing a condensate and a photocationic initiator onto a transparent resin film, a step of irradiating with active energy rays is carried out.

13. A display comprising the hard coat film according to any one of claims 1 to 11.

Images