JP2009204833A - Optical film, polarizing plate and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film having a low-refractive index layer excellent in low reflectivity, film strength, mass productivity, or the like, and a polarizing plate and an image display device which are low in reflectivity, can minimize projection of external light and make a reflected image less visible, and have superior visibility by being provided with the optical film. <P>SOLUTION: The optical film includes at least the single low-refractive index layer on a transparent support, the low-refractive index layer being obtained by curing a composition, containing (A) at least one type among a hydrolysate and/or a condensation reaction product of organosilane and (B) a polyrotaxane compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical film having a low refractive index layer, a polarizing plate using the optical film, and an image display device using the optical film or the polarizing plate on the outermost surface of a display.

  In general, in a display device such as a cathode ray tube display (CRT), plasma display (PDP), electroluminescence display (ELD), or liquid crystal display (LCD), it prevents contrast deterioration and image reflection due to reflection of external light. For this purpose, an optical film is provided on the outermost surface of the image display device so as to provide a low refractive index layer and reduce the reflectance using the principle of optical interference.

  Since such an optical film is disposed on the outermost surface of the image display device, the low refractive index layer as the uppermost layer is required to have high scratch resistance. However, in order to realize high scratch resistance in the low refractive index layer which is a thin film, the strength of the coating itself and excellent adhesion to the lower layer are required.

  In the optical film, it is necessary to lower the refractive index of the low refractive index layer in order to realize a low reflectance. As one of the means for forming a low refractive index layer, it is known to use a condensation-cured film of an organosilane compound, and it has been studied to lower the refractive index by using hollow silica fine particles in combination. (Patent Document 1). Although a certain degree of refractive index reduction is achieved by this method, there is a problem that when the content of the hollow silica particles is increased to further decrease the refractive index, the strength of the film is reduced. In addition, the strength of the interface between the low refractive index layer and the adjacent layer is not always sufficient, and it is necessary to perform an alkali treatment on the adjacent layer in order to strengthen the bonding force of the interface, and the optical film manufacturing process is complicated and the productivity is Improvement was desired.

On the other hand, studies for imparting scratch resistance with a non-exposed surface coating have been made, and a paint containing a lipophilic polyrotaxane having a hydrophobic group introduced has been proposed (Patent Document 2). This patent document discloses that the curable non-exposed surface coating film having a film thickness of about 20 to 40 μm improves the scratch resistance against the friction cloth. However, there is no suggestion of applying this technique to a low refractive index layer for an optical film having a film thickness of less than 1 μm.
JP 2002-317152 A JP 2007-106863 A

  The object of the present invention is to provide an optical film excellent in antireflection ability first, secondly to provide an optical film excellent in coating strength, and thirdly suitable for mass production. It is to provide an optical film with a simple manufacturing process, and fourth, to provide a polarizing plate or an image display device including these optical films.

  As a result of the study, we found that the above problem can be solved by the following method.

That is, the above object of the present invention has been achieved by the following means.
(1) It has at least one low refractive index layer on a transparent support, and the low refractive index layer is (A) at least one compound of an organosilane hydrolyzate and / or condensation reaction product, And (B) an optical film obtained by curing a composition containing a polyrotaxane compound.
(2) The optical film as described in (1), wherein the organosilane of (A) is represented by the following general formula (I).
General formula ^{(I): (R 10)} m -Si (X) 4-m
(In the general formula (I), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. M represents an integer of 0 to 3. X represents a hydroxyl group or a hydrolyzable group. To express.)
(3) The optical film as described in (1) or (2), wherein the low refractive index layer further contains (C) low refractive index inorganic fine particles.
(4) The optical film according to any one of (1) to (3), wherein the low refractive index inorganic fine particles (C) are inorganic fine particles mainly composed of porous or hollow silica. .
(5) The optical film as described in any one of (1) to (4), which has at least one optical functional layer between the transparent support and the low refractive index layer.
(6) A polarizing plate, wherein the optical film according to any one of (1) to (5) is used for at least one of the two protective films of the polarizing film in the polarizing plate.
(7) An image display device, wherein the optical film according to any one of (1) to (5) or the polarizing plate according to (6) is used on the outermost surface of the display.

  According to the present invention, an optical film having a low refractive index layer excellent in at least one of low reflectivity, coating film strength, mass productivity, and the like can be provided. Further, according to the present invention, an image display device (particularly a liquid crystal display device) in which a polarizing plate using an optical film is arranged on the outermost layer has a low reflectance, little reflection of external light, and a reflected image is not conspicuous. , Has excellent visibility.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. In the present specification, a “group” such as an alkyl group may or may not have a substituent unless otherwise specified. Further, in the case of a group having a limited number of carbon atoms, the number of carbon atoms means a number including the number of carbon atoms that the substituent has.

  The optical film of the present invention has at least one low refractive index layer on a transparent support, and the low refractive index layer is at least one of (A) organosilane, a hydrolyzate thereof, or a condensation reaction product. A composition comprising a seed compound and (B) a polyrotaxane compound is cured.

  The refractive index of the low refractive index of the present invention is not limited as long as the refractive index is 0.01 or more lower than the refractive index of the transparent support, but is preferably 1.25 to 1.48, more preferably 1.30 to 1. .43, most preferably 1.30 to 1.40.

  The thickness of the low refractive index layer of the present invention is not particularly limited as long as it satisfies the conditions for reducing the reflectance by optical interference in the range of 50 to 500 nm, but is preferably 60 to 400 nm, and more preferably in the range of 70 to 350 nm. is there.

  First, at least one compound of organosilane hydrolyzate and / or condensation reaction product (organosilane, hydrolyzate thereof, or condensation reaction product) as component (A) of the present invention. Of the compound).

  The organosilane compound used in the present invention can be used as it is or as a hydrolyzate or condensate as a binder for the low refractive index layer of the present invention. The general formula is shown below.

General formula _{^{(I) :( R 10) m}} -Si (X) 4-m

In the general formula (I), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, t-butyl, sec-butyl, hexyl, decyl, hexadecyl and the like. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include a phenyl group and a naphthyl group, and a phenyl group is preferable.

X represents a hydroxyl group or a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group (an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group and an ethoxy group), a halogen atom (for example, Cl, Br, I, etc.), and R ^2. COO groups (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples include CH ₃ COO groups and C ₂ H ₅ COO groups), preferably alkoxy groups, particularly preferably. Is a methoxy group or an ethoxy group.

m represents an integer of 0 to 3. When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively. m is preferably 0, 1 or 2.

The substituent contained in R ¹⁰ is not particularly limited, but is a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl group, ethyl group, i -Propyl group, propyl group, t-butyl group etc.), aryl group (phenyl group, naphthyl group etc.), aromatic heterocyclic group (furyl group, pyrazolyl group, pyridyl group etc.), alkoxy group (methoxy group, ethoxy group) , I-propoxy group, hexyloxy group, etc.), aryloxy group (phenoxy group, etc.), alkylthio group (methylthio group, ethylthio group, etc.), arylthio group (phenylthio group, etc.), alkenyl group (vinyl group, 1-propenyl group) Etc.), acyloxy groups (acetoxy group, acryloyloxy group, methacryloyloxy group, etc.), alkoxycarbonyl groups (me Toxylcarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (phenoxycarbonyl group, etc.), carbamoyl group (carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N-methyl-N-octylcarbamoyl group) Etc.), acylamino groups (acetylamino group, benzoylamino group, acrylamino group, methacrylamino group, etc.) and the like, and these substituents may be further substituted. In the present specification, even if a hydrogen atom is replaced by a single atom, it is treated as a substituent for convenience.

When there are a plurality of R ¹⁰ , at least one is preferably a substituted alkyl group or a substituted aryl group. Among these, the substituted alkyl group or substituted aryl group preferably further has a vinyl polymerizable group.

  Preferred compounds in the present invention include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltri Methoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, dodecyltri Methoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecylto Methoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -Trialkoxysilanes such as glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane; Examples thereof include dialkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane.

  Among these, tetramethoxysilane, tetraethoxysilane, and γ-acryloxypropyltrimethoxysilane are preferable from the viewpoints of dispersion stability and scratch resistance of inorganic particles in the cured composition.

(Hydrolysis and condensation reaction of organosilane)
In the present invention, the organosilane compound can be used in the coating composition after hydrolysis or partial condensation thereof. It is preferable that at least one of hydrolysis and condensation reaction of organosilane is performed in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium. From the viewpoint of production stability and storage stability of the inorganic oxide fine particle liquid, an acid catalyst is used in the present invention. At least one of (inorganic acids, organic acids) and a metal chelate compound is used. Among inorganic acids, hydrochloric acid, sulfuric acid, nitric acid, and organic acids preferably have an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water. Among organic acids, methanesulfonic acid, oxalic acid, phthalic acid, and malonic acid are preferable, and oxalic acid is particularly preferable.

In the present invention, the metal chelate compound used for the formation of the hydrolyzate of organosilane and the condensation reaction is represented by the general formula R ³ OH (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms). alcohol of the general formula R ⁴ COCH ₂ COR ⁵ (wherein, the R ⁴ is an alkyl group having 1 to 10 carbon atoms, R ⁵ represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms having 1 to 10 carbon atoms. And at least one metal chelate compound having a metal selected from Zr, Ti and Al as a central metal.

  The metal chelate compound can be suitably used without particular limitation as long as it has a metal selected from Zr, Ti or Al as a central metal. Within this category, two or more metal chelate compounds may be used in combination.

  Specific examples of the metal chelate compound used in the present invention include tri-n-butoxyethyl acetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n Zirconium chelate compounds such as propylacetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium , Titanium chelate compounds such as diisopropoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum Diisopropoxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonate bis (Ethyl acetoacetate) Aluminum chelate compounds such as aluminum can be mentioned.

  Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

The hydrolysis and condensation reaction of the organosilane can be performed without a solvent or in a solvent. By this reaction, the curable composition of the present invention can be produced. When a solvent is used, the concentration of the hydrolyzate of organosilane and the partial condensate thereof can be appropriately determined. As the solvent, an organic solvent is preferably used in order to uniformly mix the components. For example, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are preferable.
The solvent preferably dissolves the organosilane and the catalyst. In addition, it is preferable in the process that an organic solvent is used as a coating solution or a part of the coating solution, and those that do not impair the solubility or dispersibility when mixed with other materials such as a fluorine-containing polymer are preferable.

  Among these, examples of the alcohols include monohydric alcohols and dihydric alcohols. Among these, monohydric alcohols are preferably saturated aliphatic alcohols having 1 to 8 carbon atoms. Specific examples of these alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol. Examples thereof include monobutyl ether and ethylene glycol monoethyl ether acetate.

  Specific examples of aromatic hydrocarbons include benzene, toluene, xylene and the like. Specific examples of ethers include tetrahydrofuran and dioxane. Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, Specific examples of esters such as diisobutyl ketone include ethyl acetate, propyl acetate, butyl acetate, and propylene carbonate. These organic solvents can be used alone or in combination of two or more. The concentration of the solid content relative to the solvent in the reaction is not particularly limited, but is usually in the range of 1% by mass to 90% by mass, and preferably in the range of 20% by mass to 70% by mass.

  In the hydrolysis and condensation reaction, usually 0.3 to 2 mol, preferably 0.5 to 1 mol of water is added to 1 mol of the hydrolyzable group of the organosilane, and in the presence or absence of the solvent. Under stirring and in the presence of an acid catalyst at 25-100 ° C. When the hydrolyzable group is an alkoxy group and the acid catalyst is an organic acid, since the carboxyl group or sulfo group of the organic acid supplies protons, the amount of water added can be reduced, such as the alkoxy group of organosilane. The amount of water added to 1 mol of the hydrolyzable group is 0 to 2 mol, preferably 0 to 1.5 mol, more preferably 0 to 1 mol, and particularly preferably 0 to 0.5 mol. When alcohol is used as the solvent, it is also preferred that substantially no water is added.

  The amount of the acid catalyst used is 0.01 to 10 mol%, preferably 0.1 to 5 mol%, based on the hydrolyzable group when the acid catalyst is an inorganic acid, and the acid catalyst is an organic acid. However, when water is added, the optimal amount of use is 0.01 to 10 mol%, preferably 0.1 to 5 mol%, based on the hydrolyzable group. When substantially no water is added, it is 1 to 500 mol%, preferably 10 to 200 mol%, more preferably 20 to 200 mol%, still more preferably 50 to 50 mol% with respect to the hydrolyzable group. 150 mol%, particularly preferably 50 to 120 mol%. The reaction is carried out by stirring at 25 to 100 ° C., but is preferably controlled by the reactivity of organosilane.

(Shape and molecular weight of organosilane hydrolyzate and condensation reaction product)
The organosilane hydrolyzate and condensation reaction product used in the present invention may have a chain or a three-dimensional network structure. Moreover, as for the mass average molecular weight of these compounds, it is preferable that the mass average molecular weight in conversion of ethylene glycol is 300-10000. When the mass average molecular weight is in the above range, the coating and storage stability of the curable composition are good, and the scratch resistance of the cured film can be sufficiently secured, which is preferable. The mass average molecular weight in terms of ethylene glycol is more preferably 300 to 9000, and particularly preferably 300 to 8000.

  The mass average molecular weight is a molecular weight expressed in terms of ethylene glycol by DMF and differential refractometer detection using a GPC analyzer using columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (both trade names manufactured by Tosoh Corporation). It is.

  Next, the polyrotaxane compound which is the component (B) of the present invention will be described. The polyrotaxane has an opening portion of a cyclic molecule pierced by a linear molecule, and a plurality of cyclic molecules include the linear molecule at both ends (both ends of the linear molecule). A blocking group is arranged so that the cyclic molecule is not liberated.

(Linear molecule)
The linear molecule contained in the compound of the present invention is not particularly limited as long as it is a molecule or substance that is included in a cyclic molecule and can be integrated non-covalently and is linear. . In the present invention, the “linear molecule” refers to a molecule including a polymer and all other substances satisfying the above requirements.
In the present invention, “linear” of “linear molecule” means substantially “linear”. That is, the linear molecule may have a branched chain as long as the cyclic molecule that is a rotor is rotatable or the cyclic molecule is slidable or movable on the linear molecule. Further, the length of the “straight chain” is not particularly limited as long as the cyclic molecule can slide or move on the linear molecule.

  As the linear molecule of the present invention, hydrophilic polymers such as polyvinyl alcohol and polyvinylpyrrolidone, poly (meth) acrylic acid, cellulose resins (carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, etc.), polyacrylamide, polyethylene oxide, polyethylene Glycol, polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch, etc. and / or copolymers thereof; hydrophobic polymers such as polyethylene, polypropylene, and other olefinic monomers Polyolefin resins such as copolymer resins, polyester resins, polyvinyl chloride resins, polystyrenes such as polystyrene and acrylonitrile-styrene copolymer resins Resins, polymethylmethacrylate, (meth) acrylic acid ester copolymers, acrylic resins such as acrylonitrile-methyl acrylate copolymer resins, polycarbonate resins, polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins, etc. And derivatives or modified products thereof.

  Of these, hydrophilic polymers are preferred. The affinity with the component (A) in the low refractive index layer is good, and the dispersibility of the inorganic fine particles as the component (C) is also excellent.

  Among the hydrophilic polymers, polyethylene glycol, polypropylene glycol, a copolymer of polyethylene glycol and polypropylene glycol, polyisoprene, polyisobutylene, polybutadiene, polytetrahydrofuran, polydimethylsiloxane, polyethylene, and polypropylene are preferable. Polyethylene glycol, polyethylene glycol, and a copolymer of polyethylene glycol and polypropylene glycol are more preferable, and polyethylene glycol is particularly preferable.

  The linear molecule of the present invention itself should have a high breaking strength. The breaking strength of the low refractive index layer depends on other factors such as the bond strength between the blocking group and the linear molecule, the bond strength between the cyclic molecule and the binder of the low refractive index layer, and the bond strength between the cyclic molecules. If the linear molecule of the present invention itself has a high breaking strength, a higher breaking strength can be provided.

  The molecular weight of the linear molecule of the present invention is 1,000 or more, such as 1,000 to 1,000,000, preferably 5,000 or more, such as 5,000 to 1,000,000 or 5,000 to 500. 1,000, more preferably 10,000 or more, for example, 10,000 to 1,000,000, 10,000 to 500,000, or 10,000 to 300,000. The linear molecule of the present invention is preferably a biodegradable molecule from the viewpoint of “environmentally friendly”.

  The linear molecule of the present invention preferably has reactive groups at both ends. By having this reactive group, it can react easily with a blocking group. The reactive group depends on the block group to be used, and examples thereof include a hydroxyl group, an amino group, a carboxyl group, and a thiol group.

(Cyclic molecule)
The cyclic molecule of the present invention can be any cyclic molecule as long as it is a cyclic molecule that can be included in the linear molecule.
In the present invention, “cyclic molecule” refers to various cyclic substances including cyclic molecules. In the present invention, “cyclic molecule” refers to a molecule or substance that is substantially cyclic. That is, “substantially ring-shaped” means that the letter “C” is not completely closed, such as the letter “C”, and one end and the other end of the letter “C” are not joined. It is intended to include those having overlapping spiral structures. Furthermore, a ring for a “bicyclo molecule” to be described later can be defined in the same manner as “substantially cyclic” in “cyclic molecule”. That is, one or both rings of the “bicyclo molecule” may not be completely closed like the letter “C”, and one end and the other end of the letter “C” are connected to each other. It may have a spiral structure that is not overlapped.

  Examples of the cyclic molecule of the present invention include various cyclodextrins (for example, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, dimethylcyclodextrin and glucosylcyclodextrin, derivatives or modified products thereof), crown ethers, and the like. Benzocrowns, dibenzocrowns, and dicyclohexanocrowns, and derivatives or modified products thereof.

  The above-mentioned cyclodextrins and crown ethers differ in the size of the opening of the cyclic molecule depending on the type. Therefore, the type of linear molecule to be used, specifically, when the linear molecule to be used is assumed to be cylindrical, the cyclic molecule to be used depends on the diameter of the cross section of the cylinder, the hydrophobicity or hydrophilicity of the linear molecule, etc. Can be selected. When a cyclic molecule having a relatively large opening and a cylindrical linear molecule having a relatively small diameter are used, two or more linear molecules can be included in the opening of the cyclic molecule. . Among these, cyclodextrins are preferable from the above-mentioned “environmentally friendly” point because they have biodegradability.

  It is preferable to use α-cyclodextrin as the cyclic molecule. When the cyclic molecule is cyclodextrin, the number of cyclic molecules included in the linear molecule (inclusion amount) is preferably 0.05 to 0.60, with the maximum inclusion amount being 1. 10-0.50 is still more preferable and 0.20-0.40 is still more preferable. If it is less than 0.05, the pulley effect may not be exhibited. If it exceeds 0.60, cyclodextrin, which is a cyclic molecule, may be arranged too densely, and the mobility of cyclodextrin may be reduced. Insolubility in the organic solvent may be strengthened, and the solubility of the resulting polyrotaxane in the organic solvent may be reduced.

  The cyclic molecule of the present invention preferably has a reactive group outside the ring. When the cyclic molecules are bonded or cross-linked, the reaction can be easily performed using this reactive group. The reactive group depends on the crosslinking agent used, and examples thereof include a hydroxyl group, an amino group, a carboxyl group, a thiol group, and an aldehyde group. Moreover, it is good to use the group which does not react with a blocking group in the above-mentioned blocking reaction.

(Block base)
As the blocking group of the present invention, any group may be used as long as the cyclic molecule maintains a form in which the cyclic molecule is skewered with a linear molecule. Examples of such a group include a group having “bulkiness” and / or a group having “ionicity”. Here, the “group” means various groups including a molecular group and a polymer group. In addition, the “ionicity” of the group having “ionicity” and the “ionicity” of the cyclic molecule influence each other, for example, by repulsion, the cyclic molecule is skewered by linear molecules. It is possible to retain the form.

  The blocking group of the present invention may be a polymer main chain or a side chain as long as it retains the skewered shape as described above. When the blocking group is the polymer A, the matrix of the present invention is included in the matrix A and the compound of the present invention is included in a part thereof. The form in which A is included may be sufficient. Thus, by combining with the polymer A having various properties, a composite material having a combination of the properties of the compound of the present invention and the properties of the polymer A can be formed.

  Specifically, as a blocking group of the molecular group, dinitrophenyl groups such as 2,4-dinitrophenyl group and 3,5-dinitrophenyl group, cyclodextrins, adamantane groups, trityl groups, fluoresceins and pyrene And derivatives or modified products thereof. More specifically, even when α-cyclodextrin is used as a cyclic molecule and polyethylene glycol is used as a linear molecule, cyclodextrins, 2,4-dinitrophenyl group, 3,5-dinitrophenyl group, etc. And dinitrophenyl groups, adamantane groups, trityl groups, fluoresceins and pyrenes, and derivatives or modified products thereof.

  Next, a modified polyrotaxane that can be preferably used in the present invention will be described. In the present invention, a polyrotaxane in which a plurality of modifications described below are used in combination can be preferably used.

<Cross-linked polyrotaxane>
A crosslinked polyrotaxane refers to a compound in which two or more polyrotaxanes are chemically bonded to each other, and the two cyclic molecules may be the same or different. At this time, the chemical bond may be a simple bond or a bond via various atoms or molecules.
In addition, a molecule in which a cyclic molecule has a bridged ring structure, that is, a “bicyclo molecule” having first and second rings can be used. In this case, for example, a “bicyclo molecule” and a linear molecule can be mixed, and the crosslinked polyrotaxane can be obtained by including the linear molecule in a skewered manner in the first and second rings of the “bicyclo molecule”.
This crosslinked polyrotaxane has viscoelasticity because the cyclic molecule skewered through the linear molecule can move along the linear shape (pulley effect). The tension can be uniformly dispersed by the pulley effect, and the internal stress can be relieved.

<Hydrophobic modified polyrotaxane>
When the cyclic molecule of polyrotaxane is a cyclodextrin such as α-cyclodextrin, in the present invention, at least one hydroxyl group of cyclodextrin is substituted with another organic group (hydrophobic group). Since the solubility to the solvent contained in a layer forming composition improves, it is used more preferably.

  Specific examples of hydrophobic groups include, for example, alkyl groups, benzyl groups, benzene derivative-containing groups, acyl groups, silyl groups, trityl groups, nitrate ester groups, tosyl groups, alkyl-substituted ethylenically unsaturated groups as photocuring sites, and thermosetting sites. Examples thereof include, but are not limited to, an alkyl-substituted epoxy group. Moreover, in said hydrophobic modification polyrotaxane, you may have 1 type of the above-mentioned hydrophobic group individually or in combination of 2 or more types.

The degree of modification by the hydrophobic modifying group is preferably 0.02 or more, more preferably 0.04 or more, and more preferably 0.06 or more, assuming that the maximum number of cyclodextrin hydroxyl groups that can be modified is 1. More preferably.
If it is less than 0.02, the solubility in an organic solvent will not be sufficient, and insoluble bumps (protrusions derived from adhesion of foreign matter, etc.) may be generated.
Here, the maximum number that the hydroxyl groups of cyclodextrin can be modified is, in other words, the total number of hydroxyl groups that cyclodextrin had before modification. In other words, the degree of modification is the ratio of the number of modified hydroxyl groups to the total number of hydroxyl groups.
Although at least one hydrophobic group may be used, in that case, it is preferable to have one hydrophobic group for each cyclodextrin ring.
Further, by introducing a hydrophobic group having a functional group, the reactivity with other polymers can be improved.

<Polyrotaxane having an unsaturated double bond>
An unsaturated bond group can be introduced into the portion corresponding to the cyclic molecule. By introducing this group, polymerization with a monomer having an ethylenically unsaturated group becomes possible.
Introduction of an unsaturated bond group can be carried out, for example, by substituting at least a part of a cyclic molecule having a hydroxyl group (—OH) such as cyclodextrin with an unsaturated bond group, preferably an unsaturated double bond group. .
An unsaturated bond group, for example, an unsaturated double bond group, can include an olefinyl group, and examples thereof include, but are not limited to, an acrylic group, a methacryl (methacryloyl) group, a vinyl ether group, and a styryl group. .

  The unsaturated double bond group can be introduced by the following method. That is, a method by carbamate bond formation with an isocyanate compound or the like; a method by ester bond formation by a carboxylic acid compound, an acid chloride compound or an acid anhydride; a method by silyl ether bond formation by a silane compound or the like; a carbonate bond formation by a chlorocarbonic acid compound or the like And the like.

  When a methacryloyl group is introduced as an unsaturated double bond group via a carbamoyl bond, the polyrotaxane is dissolved in a dehydrating solvent such as DMSO or DMF, and a methacryloyl reagent having an isocyanate group is added. In addition, when introducing via an ether bond or an ester bond, a methacryloyl reagent having an active group such as a glycidyl group or an acid chloride can also be used.

  The step of substituting the hydroxyl group of the cyclic molecule with an unsaturated double bond group may be before the step of preparing the pseudopolyrotaxane, between the steps, or after the step. Further, it may be before the step of preparing the polyrotaxane by blocking the pseudopolyrotaxane, between the steps, or after the step. Furthermore, when the polyrotaxane is a crosslinked polyrotaxane, it may be before the step of crosslinking the polyrotaxanes, between the steps, or after the step. It can also be provided at these two or more times. The substitution step is preferably performed after the polyrotaxane is prepared by blocking the pseudopolyrotaxane and before the crosslinking of the polyrotaxane. The conditions used in the substitution step depend on the unsaturated double bond group to be substituted, but are not particularly limited, and various reaction methods and reaction conditions can be used.

  In the present invention, the blending amount of the polyrotaxane (B) component is the mass of [(B) component / ((A) component + (B) component)] as a ratio to the (A) component in the low refractive index layer. %, Preferably 1 to 35%, more preferably 3 to 25%, and most preferably 6 to 20%. By using in this range, compared with the case of only (A) component, a coating film becomes moderately flexible and brittleness is reduced. In addition, it is possible to improve the film strength when coexisting with the low refractive index inorganic fine particles, which will be described later as the component (C), and to improve the interface adhesion with the adjacent layer.

  In the present invention, the polyrotaxane used is preferably a hydrophobized modified polyrotaxane, more preferably a polyrotaxane having an unsaturated double bond.

  Next, the low refractive index inorganic fine particles which are the component (C) of the present invention will be described. The low refractive index inorganic fine particles used in the low refractive index layer of the present invention are preferably inorganic fine particles having a refractive index of 1.10 to 1.48. The refractive index of the particles is preferably 1.10 to 1.46, more preferably 1.15 to 1.32. The particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles. The particle size is preferably 1 to 150 nm, more preferably 5 to 100 nm, and most preferably 5 to 80 nm. Here, the particle size represents the secondary particle size in the case of aggregated particles. The particle size is measured with a transmission electron microscope. Two or more types of particles (types or particle sizes) may be used. The shape of the particles is most preferably spherical, but there is no problem even if the shape is indefinite.

  For the low refractive index inorganic fine particles of the present invention, it is preferable to use particles containing silica as a main component or inorganic fluoride particles, particularly preferably particles containing porous or hollow silica as a main component, or inorganic fluoride. Particles, most preferably hollow silica particles.

  Examples of the inorganic fluoride include aluminum fluoride (refractive index: 1.38), calcium fluoride (refractive index: 1.23-1.45), lithium fluoride (refractive index: 1.30), magnesium fluoride ( (Refractive index: 1.38 to 1.40) and the like. Among these, lithium fluoride, calcium fluoride, and magnesium fluoride are preferable, and magnesium fluoride is particularly preferable. Magnesium fluoride is most preferred in terms of particle hardness, hygroscopicity, and refractive index. Examples of commercially available magnesium fluoride include Stella Chemifa's magnesium fluoride, magnesium fluoride OP, magnesium fluoride G1, magnesium fluoride H, and Sanwa polished magnesium fluoride.

The particles containing porous or hollow silica as a main component have 60% by mass or more of silica, and may contain aluminum oxide, tin oxide, antimony oxide, or the like as subcomponents.
A preferred method for producing hollow fine particles comprises the following steps. The first step is the formation of core particles that can be removed by post-treatment, the second step is the formation of a shell layer, the third step is the dissolution of core particles, and the fourth step is the formation of an additional shell phase if necessary. Specifically, the hollow particles can be produced according to the method for producing hollow silica fine particles described in, for example, JP-A-2001-233611.

  A preferred method for producing porous particles is to produce porous core particles by controlling the degree of hydrolysis and condensation of alkoxide and the type and amount of coexisting substances as the first step, and a shell layer on the surface as the second step. It is a method of forming. Specifically, the production of porous particles can be performed by the methods described in JP-A Nos. 2003-327424, 2003-335515, 2003-226516, 2003-238140, and the like. it can.

  In the present invention, hollow silica particles are most preferable from the viewpoint of high refractive index decreasing ability, and those having a refractive index of 1.15 to 1.32 and a particle size in the range of 20 to 90 nm are preferably used. Can do.

  Further, these low refractive index inorganic particles may be used by being dispersed in an organic solvent. Organic solvents that can be used as the dispersion medium include alcohols such as methanol, ethanol, isopropyl alcohol, ethylene glycol, butanol, and ethylene glycol monopropyl ether; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and aromatics such as toluene and xylene Group hydrocarbons; amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; esters such as ethyl acetate, butyl acetate and γ-butyrolactone; ethers such as diethyl ether, tetrahydrofuran and 1,4-dioxane Etc. Of these, alcohols and ketones are preferred. These organic solvents can be used alone or in combination of two or more as a dispersion medium.

  The surface of these inorganic particles is preferably subjected to a surface treatment such as chemical modification in order to improve dispersibility. For example, it contains a hydrolyzable silicon compound having one or more alkyl groups in the molecule or a hydrolyzate thereof. Can be reacted. Such hydrolyzable silicon compounds include trimethylmethoxysilane, tributylmethoxysilane, dimethyldimethoxysilane, dibutyldimethoxysilane, methyltrimethoxysilane, butyltrimethoxysilane, octyltrimethoxysilane, dodecyltrimethoxysilane, 1,1. , 1-trimethoxy-2,2,2-trimethyl-disilane, hexamethyl-1,3-disiloxane, 1,1,1-trimethoxy-3,3,3-trimethyl-1,3-disiloxane, α-trimethylsilyl -Ω-dimethylmethoxysilyl-polydimethylsiloxane, α-trimethylsilyl-ω-trimethoxysilyl-polydimethylsiloxane, hexamethyl-1,3-disilazane, and the like.

  Furthermore, it is also preferable to treat the inorganic fine particles in the presence of an acid catalyst or a metal chelate compound described in JP-A-2005-307158, particularly preferably an organosilane compound having an ethylenically unsaturated group. preferable. A preferred compound is (meth) acryloyloxypropyltrimethoxysilane.

  In the present invention, the content of the low refractive index inorganic fine particles of the component (C) is preferably 50 to 85% by mass ratio with respect to the total amount of the low refractive index layer forming component excluding the coating solvent, and 60 to 75%. Is more preferable. By using this range, it is possible to achieve both reduction in the refractive index of the low refractive index layer and coating strength.

  The composition for forming the low refractive index layer of the present invention is a coating composition obtained by further adding a volatile solvent to (A), (B), and (C) according to the present invention described above. be able to. Although there is no restriction | limiting in the solvent of a coating composition, It is preferable to contain at least 2 types of volatile solvents. For example, it is preferable to use a combination of at least two selected from alcohol and derivatives thereof, ethers, ketones, hydrocarbons, and esters. The solvent can be selected from the viewpoint of the solubility of the binder component, the stability of the inorganic fine particles, and the adjustment of the viscosity of the coating liquid.

  A particularly preferred combination is the use of at least two, more preferably three, of alcohol and its derivatives, ketones and esters. Preferable examples include, for example, two or three of methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-methoxypropanol, 2-butoxyethanol, methyl alcohol, isopropyl alcohol, and toluene.

  The optimum viscosity of the coating composition for a low refractive index layer of the present invention is preferably 0.1 to 20 mPa · s, more preferably 0.5 to 10 mPa · s (25 ° C.) when formed by coating. .

(Layer structure of optical film)
The optical film (antireflection film) of the present invention has at least one layer on a transparent support (hereinafter sometimes referred to as support) in consideration of refractive index, film thickness, number of layers, layer order, and the like. A low refractive index layer is laminated.

  In general, the optical film of the present invention has a simplest configuration in which only a low refractive index layer is coated on a support. In order to further reduce the reflectance, the antireflection layer is preferably composed of a combination of a high refractive index layer having a higher refractive index than the support and a low refractive index layer having a lower refractive index than the substrate. Examples of configurations include two layers of a high refractive index layer / low refractive index layer from the base material side, and three layers having different refractive indices, a medium refractive index layer (having a higher refractive index than the base material or the hard coat layer). , A layer having a refractive index lower than that of a high refractive index layer) / a layer having a high refractive index / a layer having a low refractive index, and the like. Especially, it is preferable to apply | coat in order of a middle refractive index layer / high refractive index layer / low refractive index layer on the base material which has a hard-coat layer from durability, an optical characteristic, cost, productivity, etc.

  The example of the preferable layer structure of the optical film of this invention is shown below. In the following configuration, what is described as (antistatic layer) is a configuration in which a layer having other functions also has the function of an antistatic layer. Since the number of layers to be formed can be reduced by providing the antistatic layer with a function other than antistatic, this structure is preferable because productivity is improved.

・ Support / Antistatic layer / Low refractive index layer,
-Support / low refractive index layer (antistatic layer),
Support / antiglare layer (antistatic layer) / low refractive index layer,
Support / antiglare layer / antistatic layer / low refractive index layer,
Support / hard coat layer / antiglare layer (antistatic layer) / low refractive index layer,
Support / hard coat layer / antiglare layer / antistatic layer / low refractive index layer,
Support / hard coat layer / antistatic layer / antiglare layer / low refractive index layer,
Support / hard coat layer (antistatic layer) / antiglare layer / low refractive index layer,
Support / hard coat layer / high refractive index layer / antistatic layer / low refractive index layer,
Support / hard coat layer / high refractive index layer (antistatic layer) / low refractive index layer,
Support / hard coat layer / antistatic layer / high refractive index layer / low refractive index layer,
Support / hard coat layer / medium refractive index layer / high refractive index layer (antistatic layer) / low refractive index layer,
Support / hard coat layer / medium refractive index layer (antistatic layer) / high refractive index layer / low refractive index layer,
Support / hard coat layer (antistatic layer) / medium refractive index layer / high refractive index layer / low refractive index layer,
Support / antiglare layer / high refractive index layer (antistatic layer) / low refractive index layer,
Support / antiglare layer / medium refractive index layer (antistatic layer) / high refractive index layer / low refractive index layer,
Support / antistatic layer / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Antistatic layer / support / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Support / antistatic layer / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Antistatic layer / support / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Antistatic layer / support / antiglare layer / high refractive index layer / low refractive index layer / high refractive index layer / low refractive index layer.

  As long as the reflectance can be reduced by optical interference, it is not limited to these layer configurations.

  In the present invention, the optical layer is preferably formed by applying and curing a composition containing a compound containing two or more ethylenically unsaturated groups in one molecule from the viewpoint of high productivity.

  Among these compounds, esters of polyhydric alcohol and (meth) acrylic acid are preferable. More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. For example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, EO Modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-chlorohexane tetramethacrylate, polyurethane polyacrylate Over DOO, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  When the linear molecule of the polyrotaxane compound (preferably a polyrotaxane compound modified with hydrophobicity) as the component (B) of the low refractive index layer of the present invention is a polyalkylene glycol, an optical layer adjacent to the low refractive index layer It is preferable that at least a part of the compound containing an ethylenically unsaturated group is a monomer body having two or more ethylenically unsaturated groups modified with ethylene oxide or polyethylene oxide.

  In particular, when the linear molecule of the hydrophobized polyrotaxane is polyethylene glycol, a monomer body having two or more ethylenically unsaturated groups modified with ethylene oxide is preferable. By using such a modified monomer, the interfacial adhesion between the low refractive index layer and the adjacent optical layer is improved, and practical interfacial adhesion performance without surface modification treatment such as alkali treatment. It becomes possible to manufacture an optical film that satisfies the above.

The support for the film of the present invention is not particularly limited, such as a transparent resin film, a transparent resin plate, a transparent resin sheet, or transparent glass. Transparent resin films include cellulose acylate films (for example, cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone. Film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, (meth) acrylonitrile film, cycloolefin resin film, etc. Can be used.
Among these, a cellulose acylate film, a polyethylene terephthalate film, and a cycloolefin resin film are preferable.

  Although the formation method of the low refractive index layer of this invention is not specifically limited, It can form with the following application | coating methods.

  Dip coating method, air knife coating method, curtain coating method, roller coating method, wire bar coating method, gravure coating method and extrusion coating method (die coating method) (see US Pat. No. 2,681,294), micro gravure coating method, etc. A well-known method is mentioned. Among these methods, the micro gravure coating method and the die coating method are preferable.

In order to supply the film of the present invention with high productivity, an extrusion method (die coating method) is preferably used. In particular, it can be preferably used in a region having a small wet coating amount (20 cm ³ / m ² or less) such as a low refractive index layer.

In the method for drying a low refractive index layer of the present invention, it is preferable that after the low refractive index layer is applied, the low refractive index layer is conveyed by a web to a heated zone to dry the solvent.
The temperature of the drying zone is preferably 25 ° C. to 140 ° C., the first half of the drying zone is relatively low temperature, and the second half is preferably relatively high temperature.

Moreover, the dry wind after apply | coating the coating composition of each layer on a support body has the wind speed of the coating-film surface of 0.1-2 m / sec while the solid content concentration of the said coating composition is 1-50%. It is preferable to be in the range in order to prevent drying unevenness.
Moreover, after apply | coating the coating composition of each layer on a support body, the temperature difference of the conveyance roll which contacts the surface opposite to the coating surface of a support body in a drying zone, and a support body is 0 to 20 degreeC or less. Then, the drying nonuniformity by the heat transfer nonuniformity on a conveyance roll can be prevented, and it is preferable.

  The curing conditions for the low refractive index layer in the present invention vary depending on the organosilane compound and the catalyst used, but are usually preferably in the range of 20 ° C to 200 ° C. More preferably, it is 60 degreeC-140 degreeC, Most preferably, it is 80 degreeC-110 degreeC. By setting it in the above range, a sufficient curing rate can be obtained and damage to the support can be reduced. The curing time is not particularly limited, but for example, it is usually preferably 1 hour to 50 hours at 60 ° C, and preferably 1 minute to 30 minutes at 140 ° C. As the curing catalyst, it is preferable to use the acid described in the above-mentioned catalyst for hydrolysis of organosilane.

  Moreover, when the radically polymerizable compound represented by the polyfunctional acrylate is contained in the lower surface of the low refractive index layer, ionizing radiation can be irradiated before, during or after the thermosetting. The interface bond between both layers is strengthened, and the scratch resistance of the coating film is improved.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

Preparation of Polyrotaxane and Crosslinked Polyrotaxane Polyrotaxane and crosslinked polyrotaxane were prepared with reference to the following preparation methods described in Japanese Patent No. 2810264 and Japanese Patent No. 3475252.

  A method for preparing a compound using α-cyclodextrin as a cyclic molecule, polyethylene glycol as a linear molecule, 2,4-dinitrophenyl group as a blocking group, and cyanuric chloride as a crosslinking agent is described.

  For subsequent blocking treatment, both ends of polyethylene glycol are modified with amino groups to obtain polyethylene glycol derivatives. A polyrotaxane is prepared by mixing α-cyclodextrin and a polyethylene glycol derivative. At the time of preparation, when the maximum inclusion amount is 1, for example, the mixing time is 1 to 48 hours so that the inclusion amount is 0.001 to 0.6 with respect to 1, and the mixing temperature is 0 ° C. to It can be 100 degreeC.

  Generally, up to 230 α-cyclodextrins can be packaged with respect to an average molecular weight of 20,000 of polyethylene glycol. Therefore, this value is the maximum inclusion amount. The above conditions are such that the average molecular weight of polyethylene glycol is 20,000, and α-cyclodextrin has an average of 60 to 65 (63), that is, a maximum inclusion amount of 0.26 to 0.29 (0.28). This is a condition for inclusion by value. The inclusion amount of α-cyclodextrin can be confirmed by NMR, light absorption, elemental analysis and the like.

The obtained polyrotaxane is reacted with 2,4-dinitrofluorobenzene dissolved in DMF to obtain a blocked polyrotaxane.
Next, the resulting blocked polyrotaxane is dissolved in an aqueous sodium hydroxide solution. By adding cyanuric chloride and reacting with this liquid, a crosslinked polyrotaxane in which α-cyclodextrins are crosslinked is obtained.

[Preparation of Unmodified Polyrotaxane (PR-1)]
<Activation of both ends of polyethylene glycol>
In a 100 ml Erlenmeyer flask, 4 g of polyethylene glycol (abbreviated as PEG; average molecular weight 20,000) and 20 ml of dry methylene chloride were added to dissolve PEG. This solution was placed under an argon atmosphere, 0.8 g of 1,1′-carbonyldiimidazole was added, and the mixture was stirred and reacted at room temperature (20 ° C.) for 6 hours under an argon atmosphere.

  The reaction product obtained above was poured into 300 ml of diethyl ether stirred at high speed. After leaving still for 10 minutes, the liquid which has a deposit was centrifuged at 10,000 rpm for 5 minutes. The precipitate was taken out and dried in vacuum at 40 ° C. for 3 hours.

  The resulting product was dissolved in 20 ml of methylene chloride. This solution was added dropwise to 10 ml of ethylenediamine over 3 hours, followed by stirring for 40 minutes. The obtained reaction product was subjected to a rotary evaporator to remove methylene chloride, then dissolved in 50 ml of water, put into a dialysis tube (molecular weight cut off 8,000), and dialyzed in water for 3 days. The obtained dialyzate was dried with a rotary evaporator, and this dried product was dissolved in 20 ml of methylene chloride and reprecipitated with 180 ml of diethyl ether. The liquid having a precipitate was centrifuged at 100,000 rpm for 5 minutes and vacuum-dried at 40 ° C. for 2 hours to obtain 2.83 g of a product having amino groups introduced at both ends of PEG.

<Preparation of polyrotaxane>
After dissolving 3.6 g of α-cyclodextrin (abbreviated as α-CD) and 0.9 g of the above-prepared compound (molecular weight of about 20,000) in 15 ml of water at 80 ° C., they were mixed and mixed for 6 hours at 5 ° C. Refrigerated to prepare a polyrotaxane. Then, it vacuum-dried at 40 degreeC for 12 hours.

<Preparation of blocked polyrotaxane>
The polyrotaxane obtained above was placed in a 100 ml Erlenmeyer flask. Separately, a solution prepared by mixing 10 ml of N, N-dimethylformamide and 2.4 ml of 2,4-dinitrofluorobenzene was prepared, and this mixed solution was dropped into a flask containing polyrotaxane. Reacted. After 5 hours, 40 ml of dimethyl sulfoxide was added to the mixture to make a clear solution. The solution was added dropwise to 750 ml of water that was vigorously stirred to obtain a pale yellow precipitate. This precipitate was redissolved in 50 ml of dimethyl sulfoxide, and this dissolved substance was added dropwise to 700 ml of a vigorously stirred 0.1% sodium chloride aqueous solution and precipitated again. This precipitate was washed with water and methanol, and then centrifuged at 10,000 rpm for 1 minute three times. The obtained substance was vacuum-dried at 50 ° C. for 12 hours to obtain a blocked polyrotaxane, that is, 3.03 g of an unmodified polyrotaxane (PR-1).

[Preparation of Hydrophobized Modified Polyrotaxane (PR-2)]
<Preparation of end-capped polyrotaxane>
4.5 g of polyethylene glycol bisamine having a number average molecular weight of 20,000 and 18.0 g of α-cyclodextrin were added to 150 mL of water and dissolved by heating to 80 ° C. The solution was cooled and allowed to stand at 5 ° C. for 16 hours. The produced white paste-like precipitate was collected and dried.

  To the dried product, a mixed solution of 12.0 g of 2,4-dinitrofluorobenzene and 50 g of dimethylformamide was added and stirred at room temperature for 5 hours. The reaction mixture was dissolved by adding 200 mL of dimethyl sulfoxide (DMSO), and then poured into 3750 mL of water to separate a precipitate. The precipitate was redissolved in 250 mL of DMSO and then poured again into 3500 mL of 0.1% saline to separate the precipitate. The precipitate was washed with water and methanol three times each, and then vacuum-dried at 50 ° C. for 12 hours, whereby polyethylene glycol bisamine was included in α-cyclodextrin in a skewered manner, and both terminal amino groups had 2 Thus, 2.0 g of an inclusion compound to which a 4-dinitrophenyl group was bonded was obtained.

The obtained inclusion compound (end-blocked blocked polyrotaxane) was subjected to ultraviolet light absorption measurement and ¹ H-NMR measurement, and the inclusion amount of α-cyclodextrin was calculated. The inclusion amount was 72. there were.

The inclusion amount can be calculated from ultraviolet absorption measurement and ¹ H-NMR measurement. Specifically, in the ultraviolet absorption measurement, the molar absorption coefficient at 360 nm of each of the synthesized inclusion compound and 2,4-dinitroaniline is calculated. The inclusion amount of cyclodextrin was calculated by measurement. Moreover, in < ¹ > H-NMR measurement, it computed from the integral ratio of the hydrogen atom of a polyethylene part, and the hydrogen atom of a cyclodextrin part.

<Acetyl modification of blocked polyrotaxane with end-capping>
1 g of the clathrate compound synthesized above (end-blocked blocked polyrotaxane) was dissolved in 50 g of a lithium chloride / N, N-dimethylacetamide 8% solution. Thereto were added 6.7 g of acetic anhydride, 5.2 g of pyridine, and 100 mg of N, N-dimethylaminopyridine, and the mixture was stirred overnight at room temperature. The reaction solution was poured into methanol, and the precipitated solid was separated by centrifugation. The separated solid was dried and then dissolved in acetone. The solution was poured into water, and the precipitated solid was separated by centrifugation and dried to obtain 1.2 g of acetyl-modified hydrophobized modified polyrotaxane (PR-2).

The obtained acetyl-modified polyrotaxane was subjected to ¹ H-NMR measurement, and the amount of acetyl introduced was calculated. The amount introduced was 75%.

[Preparation of Crosslinked Polyrotaxane Compound (PR-3)]
A solution prepared by dissolving 0.18 g of cyanuric chloride in 20 g of acetone was slowly added dropwise to 80 g of vigorously stirred ice water. Thus, a cyanuric chloride dispersion (liquid A) was obtained. Separately, a solution (liquid B) was prepared by dissolving 2.4 g of α-cyclodextrin and 0.53 g of sodium carbonate in 200 g of water.

  The liquid A was added dropwise to the liquid B being slowly stirred. Thereafter, the temperature of the liquid was raised to 50 ° C., and stirring was continued for 6 hours. Thereafter, the solution temperature was lowered to 25 ° C. to obtain a solution (Liquid C). Liquid C was mixed with a solution obtained by dissolving 10 g of polyethylene glycol (average molecular weight 20000) in 700 g of water, and the mixture was slowly stirred at 25 ° C. for 24 hours. Furthermore, this liquid was concentrated using an evaporator until the whole became 500 g to obtain a solution (liquid D). A solution (liquid E) in which 0.46 g of 1-aminododecane was dissolved in 500 g of tetrahydrofuran was mixed with the liquid D and stirred at 80 ° C. for 6 hours. Further, 0.21 g of sodium carbonate was dissolved in this liquid to obtain a solution (liquid F).

  A solution obtained by dissolving 0.21 g of methacrylic acid chloride in 20 g of tetrahydrofuran was added to the liquid F containing triethylamine, and the mixture was reacted at 50 ° C. for 6 hours with stirring. The produced triethylamine hydrochloride was filtered off to obtain a solution (liquid G). The solvent of this liquid G was removed using an evaporator to obtain a crosslinked polyrotaxane compound (PR-3).

[Preparation of polyrotaxane (PR-4) having an unsaturated double bond]
<Introduction of polymerizable group>
1 g of the acetyl-modified polyrotaxane (PR-2) synthesized above was dissolved in 50 g of an 8% solution of lithium chloride / N, N-dimethylacetamide. Thereto were added 5.9 g of acrylic acid chloride, 5.2 g of pyridine, and 100 mg of N, N-dimethylaminopyridine, and the mixture was stirred at room temperature overnight. The reaction solution was poured into methanol, and the precipitated solid was separated by centrifugation. The separated solid was dried and then dissolved in acetone. The solution was poured into water, and the precipitated solid was separated by centrifugation and dried to obtain 0.8 g of polyrotaxane (PR-4) modified with acryloyl and acetyl.

The obtained acryloyl and acetyl modified polyrotaxane (PR-4) were subjected to ¹ H-NMR measurement, and the amount of acryloyl and acetyl introduced was calculated. The amount introduced was 87%. That is, the introduction amount of acryloyl is 12%.

(Preparation of hollow silica dispersion C)
Hollow silica fine particle sol (isopropyl alcohol silica sol, average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20 mass%, silica particle refractive index 1.31) was changed in size according to Preparation Example 4 of JP-A-2002-79616. Produced.

(Preparation of coating liquid for hard coat layer (HCL-1))
A coating liquid having the following composition was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating liquid for hard coat layer (HCL-1).
───────────────────────────────────
Composition of hard coat layer coating solution (HCL-1) ───────────────────────────────────
DPHA 10.0 g
PET-30 36.0 g
Viscote 360 10.0 g
Irgacure 127 2.0 g
SP-13 0.04g
Methyl isobutyl ketone 20.0 g
Methyl ethyl ketone 10.0 g
───────────────────────────────────

(Preparation of hard coat layer coating solution (HCL-2))
A coating solution having the following composition was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution for hard coat layer (HCL-2).
───────────────────────────────────
Composition of hard coat layer coating liquid (HCL-2) --------------------------
DPHA 10.0 g
PET-30 46.0 g
Irgacure 127 2.0 g
SP-13 0.04g
Methyl isobutyl ketone 20.0 g
Methyl ethyl ketone 10.0 g
───────────────────────────────────

The compounds used are shown below.
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate [manufactured by Nippon Kayaku Co., Ltd.]
PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [manufactured by Nippon Kayaku Co., Ltd.]
・ Biscoat 360: Ethylene oxide-modified trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Co., Ltd.)
・ Irgacure 127: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
SP-13: Fluorine leveling agent

[Coating of hard coat layer]
80 μm thick triacetyl cellulose film “TAC-TD80U” {manufactured by FUJIFILM Corporation} (refractive index: 1.48) using the slot die coater described in FIG. ) In the form of a roll, the hard coat layer coating solution (HCL-1) is applied so that the dry film thickness is 13 μm, dried at 30 ° C. for 15 seconds, and at 90 ° C. for 40 seconds, and further nitrogen. Using an "air-cooled metal halide lamp" {manufactured by Eye Graphics Co., Ltd.} of 160 W / cm in an atmosphere with an oxygen concentration of 100 ppm or less, the coating layer is cured by irradiating with an irradiation dose of 70 mJ / cm ² by purging. A hard coat film (HC-101) was prepared and wound up.

  In producing the hard coat film (HC-101), a hard coat film (HC-102) was produced in the same manner except that the type of the hard coat layer coating solution was changed to (HCL-102).

  The obtained hard coat film was immersed in a 1.5 mol / L, 50 ° C. NaOH aqueous solution for 2 minutes for alkali treatment, washed with water, neutralized with 0.05 mol / L sulfuric acid aqueous solution for 30 seconds, and then washed with water. -It dried and saponified. In this way, saponified hard coat films (HCL-1K, HCL-2K) were obtained.

(Preparation of coating solution for low refractive index layer (Ln-1))
A mixture of 32.1 g of normal ethyl silicate (SiO ₂ concentration 28 wt%) and 1.22 g of nonadecafluorododecyltrimethoxysilane in 55.0 g of isopropyl alcohol, 10 g of pure water and 1.69 g of nitric acid with a concentration of 61 wt%. The mixture was mixed and stirred at 50 ° C. for 1 hour to prepare a matrix-forming component liquid (M-1) having a solid concentration of 10% by weight.

  Next, 1.0 g of methyl ethyl ketone and 1.0 g of cyclohexanone are added to 10.0 g of the matrix-forming component liquid (M-1), and further diluted with isopropyl alcohol to obtain a low refractive index layer having a solid content concentration of 1.0% by weight. Coating solution (Ln-1) was prepared.

(Preparation of coating solution for low refractive index layer (Ln-2 to Ln-10))
In preparing the coating liquid for low refractive index layer (Ln-1), the components other than the solvent were changed as shown in Table 1, and the amount of isopropyl alcohol was adjusted so that the solid content concentration was 1.0%. A coating solution for a low refractive index layer was prepared.

On the hard coat (HC-101), using the coating liquids Ln-1 to Ln-17 for the low refractive index layer, adjusting the thickness of the low refractive index layer to 95 nm, and applying with a die coater. After drying at 30 ° C. for 15 seconds and at 80 ° C. for 120 seconds, curing was further performed at 110 ° C. for 15 minutes. After that, using an “air-cooled metal halide lamp” {manufactured by Eye Graphics Co., Ltd.) of 240 W / cm under an atmosphere with an oxygen concentration of 100 ppm or less by nitrogen purge, ultraviolet rays with an irradiation amount of 500 mJ / cm ² were irradiated. Film samples 101-117 were produced. Also, optical film samples 118 to 123 in which the combinations of the hard coat and the low refractive index layer were changed as shown in Table 2 were produced.

(Evaluation of optical film)
The following evaluation was performed using said optical film.
(1) Average reflectance After the surface of the antireflection hard coat film on which the hard coat layer is not laminated is roughened with sandpaper, light absorption treatment with black ink (transmittance at 380 to 780 nm is less than 10%) ) Was performed on a black table under the following conditions.
A spectrophotometer “V-550” (manufactured by JASCO Corporation) is fitted with an adapter “ARV-474” and has a specular reflectance with an output angle of −5 ° at an incident angle of 5 ° in the wavelength region of 380 to 780 nm. The average reflectance of 450 to 650 nm was used for the result.

(2) Pencil hardness evaluation Pencil hardness evaluation described in JIS K 5400 was performed as an index of scratch resistance. After conditioning the anti-reflective hard coat film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, using a pencil for HB to 5H specified in JIS S 6006, with a load of 4.9 N with a pencil The scratch test was repeated 5 times, and the sample was allowed to stand for 24 hours under conditions of a temperature of 25 ° C. and a humidity of 60% RH, and then evaluated according to the following criteria.
OK: No more than 2 scratches in the evaluation of n = 5 NG: No less than 3 scratches in the evaluation of n = 5 The pencil hardness reflects the hardness of the low refractive index layer itself and is adjacent to the low refractive index layer It also reflects the adhesion strength of the interface.

(3) Eraser scratch resistance evaluation By using a rubbing tester and a rubbing test under the following conditions, it can be used as an index for the eraser scratch resistance.
Evaluation environmental conditions: 25 ° C., 60% RH
Rubbing material: Plastic eraser (dragonfly pencil MONO)
Fixed to the tip (1 cm x 1 cm) of the scraper of the tester that comes into contact with the sample.
Rubbing speed: 2 cm / second,
Load: 500 g / cm ²
Tip contact area: 1 cm × 1 cm,
Number of rubs: 100 round trips.
Oily black ink was applied to the back side of the rubbed sample, the scratches on the rubbing portion were visually observed with reflected light, and the scratches on the rubbing portion were evaluated according to the following criteria.
○: Even if you look very carefully, no scratches are visible.
○ △: Slightly weak scratches are visible when viewed very carefully.
Δ: Weak scratches are visible.
Δ ×: moderate scratches are visible.
X: There is a scratch that can be seen at first glance.
XX: Single-sided film is damaged.
The eraser scuff resistance mainly reflects the hardness of the low refractive index layer itself.

  The evaluation results are shown in the following table.

  According to the said table | surface, adhesion | attachment with an adjacent lower layer is strengthened by using together an organosilane compound and a rotaxane compound in a low-refractive-index layer, and pencil hardness is rising. Furthermore, even when low refractive index inorganic fine particles are used in combination to reduce the refractive index, the effect is remarkable. Moreover, the effect is remarkable with the rotaxane which has a hydrophobic treatment and an unsaturated double bond. It can also be seen that the use of an alkylene oxide-modified monomer in the layer adjacent to the low refractive index layer enhances the adhesion at the interface.

<Production of polarizing plate, liquid crystal display device>
Iodine is adsorbed on polyvinyl alcohol and stretched on one side of a polarizer prepared by dipping in a 1.5 mol / L, 55 ° C. NaOH aqueous solution for 2 minutes, neutralized, washed with water, and 80 μm thick triacetyl. A cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) was adhered, and the optical films of the samples 101 to 123 were bonded to the other surface of the polarizer to produce a polarizing plate.

  Using this polarizing plate, a liquid crystal display device in which a low refractive index layer was arranged as the outermost layer was produced. As a result, the liquid crystal had low reflectivity, little reflection of external light, and the reflected image was not noticeable and had excellent visibility. A display device was obtained.

Claims (7)

  And having at least one low refractive index layer on the transparent support, wherein the low refractive index layer is (A) at least one compound of hydrolyzate of organosilane and / or condensation reaction product, and (B ) An optical film obtained by curing a composition containing a polyrotaxane compound. The optical film according to claim 1, wherein the organosilane (A) is represented by the following general formula (I).
General formula ^{(I): (R 10)} m -Si (X) 4-m
(In the general formula (I), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. M represents an integer of 0 to 3. X represents a hydroxyl group or a hydrolyzable group. To express.)   The optical film according to claim 1 or 2, wherein the low refractive index layer further contains (C) low refractive index inorganic fine particles.   The optical film according to claim 1, wherein the low refractive index inorganic fine particles (C) are inorganic fine particles mainly composed of porous or hollow silica.   5. The optical film according to claim 1, comprising at least one optical functional layer between the transparent support and the low refractive index layer.   The optical film in any one of Claims 1-5 is used for at least one of the two protective films of the polarizing film in a polarizing plate, The polarizing plate characterized by the above-mentioned.   An optical display according to any one of claims 1 to 5 or the polarizing plate according to claim 6 is used on the outermost surface of a display.