JP2009186776A - Hard coating film and method of manufacturing the same, and optical function film and optical lens provided with hard coating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard coating film of high transparency having an enhanced refractive index and hardness, and a method of manufacturing the film, and to provide an optical function film and an optical lens provided with the hard coating film. <P>SOLUTION: The hard coating film has an inorganic oxide particle having 1 nm or more to 20 nm or less of average distribution diameter, and a resin having a hydrophilic group and introduced with an acrylic group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hard coat film, a method for producing the same, and an optical functional film and an optical lens provided with the hard coat film. More specifically, the light transmittance for visible light is high, and the refractive index and toughness can be improved. By providing the hard coat film and the manufacturing method thereof, the light transmittance is high by providing the hard coat film, the optical function film having excellent refractive index and toughness, and by providing the hard coat film, the light transmittance is high, The present invention relates to an optical lens having excellent refractive index and toughness.

Conventionally, polycarbonate (PC), polymethyl methacrylate (PMMA), cyclic olefin-based resins, and the like have been widely used as transparent plastic materials for optics.
However, when these transparent plastic materials are applied to optical lenses for projectors, optical lenses and substrates for optical disk pickups, substrates for flat panel displays (FPD), etc., polycarbonate has a large birefringence, Polymethylmethacrylate has high water absorption and insufficient heat resistance.
Further, the cyclic olefin-based resin that can solve these problems also has problems such as low scratch resistance and easy scratching on the surface.

In general, in order to improve the scratch resistance of the surface of these optically transparent plastic materials, there is a method of forming a hard coat layer on the surface, which has been widely used. Among them, a high refractive index hard coat layer is used for applications such as prevention of interference fringes between a plastic lens and a hard coat layer and a hard coat for an antireflection film (see, for example, Patent Documents 1 and 2).
Further, as a composite composition in which inorganic fine particles are uniformly dispersed in a resin matrix and have excellent transparency and a high refractive index, a block copolymer composed of a hydrophobic segment and a hydrophilic segment, and a number average particle An optical component such as a lens substrate made of an organic-inorganic composite composition containing inorganic fine particles having a diameter of 1 nm to 15 nm has been proposed (see, for example, Patent Document 3).
JP 2004-1393 A JP-A-11-302597 JP 2007-2111164 A

  By the way, as a material used for the conventional high refractive index hard coat layer, a composite material in which a high refractive index filler such as zirconia, titania, tin oxide or the like is contained in a resin can be given. However, since all the high refractive index fillers are agglomerated severely, even if fine particles having a primary particle size of several nanometers are kneaded in the resin in order to improve light transmittance, Therefore, the high refractive filler could not be uniformly dispersed in the resin, and the light transmittance could not be improved. In addition, since the high refractive index filler is an oxide, the polarity is strong, that is, hydrophilic, whereas the resin used for the hard coat layer is generally weak in polarity and not hydrophilic. There was also a problem that the affinity of the resin was low and a sufficient mixed state could not be obtained.

Therefore, in order to weaken the polarity of the surface of the high refractive index filler and prevent aggregation, a surface treatment agent for performing the surface treatment of the high refractive index filler is required. This surface treatment agent is also referred to as a dispersant because it is for dispersing inorganic fine particles in the resin.
For example, in the organic-inorganic composite composition forming the optical component, as described in paragraphs 0051 to 0057, paragraph 0064, etc. of Patent Document 3, a dispersant is used to disperse the inorganic fine particles in the resin. It may be used. Furthermore, in this organic-inorganic composite composition, as described in paragraph 0076 (Example) of Patent Document 3, since toluene is used to disperse the inorganic fine particles in the resin, the inorganic oxidation is performed by the dispersant. It was necessary to treat the surface of the product particles.

  However, since the refractive index of the surface treatment agent (dispersant) is lower than that of the high refractive index filler, the refractive index of the surface-treated high refractive index filler is lower than that of the filler alone, and is remarkable even when mixed with a resin. There has been a problem that the effect of increasing the refractive index cannot be obtained. For this reason, there is a problem that it is difficult to further improve the refractive index while maintaining the light transmittance and hardness of the hard coat layer with respect to visible light.

  The present invention has been made to solve the above-mentioned problems, and has a high transparency, a hard coat film with improved refractive index and hardness, a method for producing the same, an optical functional film including the hard coat film, and An object is to provide an optical lens.

  As a result of intensive studies to solve the above problems, the present inventors have introduced inorganic oxide fine particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, a hydrophilic group, and an acrylic group. If a hard coat film made of a composite composition mixed with a resin is used, a surface treatment agent (dispersant) is unnecessary, and while maintaining transparency, the hard coat film has sufficient hardness while improving the refractive index. The inventors have found that a film can be produced and have completed the present invention.

  That is, the hard coat film of the present invention comprises inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, and a resin having a hydrophilic group and an acrylic group introduced therein. And

The resin is preferably a water-soluble resin.
The water-soluble resin is preferably acrylic modified polyvinyl alcohol and / or a modified product of acrylic modified polyvinyl alcohol.
The inorganic oxide particles are preferably made of zirconium oxide and / or titanium oxide.

The method for producing a hard coat film of the present invention comprises mixing inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, water, and a resin having a hydrophilic group and having an acrylic group introduced therein. A mixed liquid is prepared, the mixed liquid is applied onto a substrate to form a coating film, and water is removed from the coating film.
The method for producing a hard coat film of the present invention comprises an aqueous dispersion in which inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less are dispersed in water, a hydrophilic group, and an acrylic group. A mixed liquid is prepared by mixing with the introduced resin, and the mixed liquid is applied onto a substrate to form a coating film, and water is removed from the coating film.

The resin is preferably a water-soluble resin.
The water-soluble resin is preferably acrylic modified polyvinyl alcohol and / or a modified product of acrylic modified polyvinyl alcohol.
The inorganic oxide particles are preferably made of zirconium oxide and / or titanium oxide.

  The optical functional film of the present invention is characterized by comprising the hard coat film of the present invention at least in a light transmission region.

  The optical lens of the present invention comprises the hard coat film of the present invention at least in a light transmission region.

  According to the hard coat film of the present invention, since it contains inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, and a resin having a hydrophilic group and an acrylic group introduced, A processing agent is not required, and a hard coat film having a high refractive index and improved hardness while maintaining transparency can be obtained. Then, by using this hard coat film and forming a resin optical part such as an optical functional film or an optical lens in combination with a highly transparent / low refractive index resin such as acrylic resin, the refractive index difference is sufficiently high ( Δ0.2 or more) By controlling, it is possible to obtain an optical component with improved characteristics and easy manufacture.

  According to the method for producing a hard coat film of the present invention, an inorganic oxide particle having an average dispersed particle diameter of 1 nm or more and 20 nm or less, water, a resin having a hydrophilic group and having an acrylic group introduced therein are mixed. To prepare a mixed solution, and apply the mixed solution on a substrate to form a coating film, and remove water from the coating film. Therefore, inorganic oxidation is not carried out in the resin without using an organic solvent such as toluene. A hard coat film in which fine particles are uniformly dispersed can be produced.

  Since the optical functional film or optical lens of the present invention is provided with the hard coat film of the present invention at least in the light transmission region, the refractive index difference between the substrate and the hard coat film is sufficiently maintained while maintaining transparency. It is possible to obtain an optical functional film or optical lens that can be controlled high (Δ0.2 or more) and provided with a hard coat film having sufficient hardness.

The best mode of the hard coat film of the present invention, the production method thereof, the optical functional film provided with the hard coat film, and the optical lens will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the optical lens of the present invention.
In FIG. 1, reference numeral 10 denotes an optical lens, 20 denotes a transparent base material made of a flat transparent composite, 21 denotes a base part of the transparent base material 20, and 22 denotes a surface (one surface) 21a of the base part 21 of the transparent base material 20. A substantially convex hemispherical convex lens portion provided integrally with a part (center portion) of the lens, and 23 indicate a hard coat film formed so as to cover the entire transparent substrate 20.
In the optical lens 10, the base 21 and the entire convex lens portion 22 of the transparent base material 20 are light transmission regions.

The transparent substrate 20 may be a substrate having transparency with respect to light in a predetermined wavelength band such as visible light or near infrared, and is thermoplastic, thermosetting, light by visible light, ultraviolet light, infrared light, or the like ( A substrate made of a curable resin such as (electromagnetic wave) curable and electron beam curable by electron beam irradiation is preferably used.
Examples of the resin constituting the base material include acrylates such as polymethyl methacrylate (PMMA) and polycyclohexyl methacrylate; polycarbonate (PC); polystyrene (PS); polyether; polyester; polyarylate; Polyamide; phenol-formaldehyde (phenol resin); diethylene glycol bisallyl carbonate; acrylonitrile / styrene copolymer (AS resin); methyl methacrylate / styrene copolymer (MS resin); poly-4-methylpentene; norbornene polymer; Examples thereof include polyurethane; epoxy; silicone and the like.

  The hard coat film 23 is a thin film containing inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less and a resin having a hydrophilic group and an acrylic group introduced therein.

  The inorganic oxide particles include titanium oxide (2.3 to 2.7) having a refractive index of 2.0 or more, potassium titanate (2.68), barium titanate (2.3 to 2.5), oxidation Zirconium (2.05 to 2.4), zinc oxide (2.01 to 2.03) and the like can be mentioned. These may be used alone or in combination of two or more. Among these inorganic oxide particles, preferred are titanium oxide and zirconium oxide, which can be obtained with a small particle size when used as a filler. However, titanium oxide may have surface activity (organic matter decomposability). Particularly preferred is zirconium oxide.

  The reason why the refractive index of the inorganic oxide particles is preferably 2.0 or more is that even if the content of the inorganic oxide particles in the hard coat film 23 is lowered, the refractive index of the hard coat film 23 is sufficiently adjusted. It is possible. Further, when the content of the inorganic oxide particles in the hard coat film 23 is increased, the resin properties are hindered due to a decrease in the transmittance of the hard coat film 23, embrittlement, cracking, and the like, so the content is small. Is preferred.

The reason why the average dispersed particle size of the inorganic oxide fine particles is 1 nm or more and 20 nm or less is that when the average dispersed particle size is less than 1 nm, the crystallinity becomes poor and the refractive index decreases, This is because if the average dispersed particle size of the inorganic oxide fine particles exceeds 20 nm, light scattering (Rayleigh scattering) by the inorganic oxide fine particles becomes remarkable, and the transparency of the transparent composite is lowered.
Thus, since the inorganic oxide fine particles are nano-sized particles, even when the inorganic oxide fine particles are dispersed in the resin to form the hard coat film 23, light scattering is small and the hard coat film 23 It is possible to maintain transparency.

The content of the inorganic oxide fine particles in the hard coat film 23 is preferably 1% by mass to 90% by mass, more preferably 10% by mass to 60% by mass, and still more preferably 20% by mass to 40% by mass. It is as follows.
Here, the reason why the content of the inorganic oxide fine particles in the hard coat film 23 is preferably 1% by mass or more and 90% by mass or less is that the content of the inorganic oxide particles is less than 1% by mass in the hard coat film 23. On the other hand, if the content of the inorganic oxide particles exceeds 90% by mass, the resin properties (( This is because flexibility and specific gravity are hindered.

The resin having a hydrophilic group is preferably a water-soluble resin.
Here, having a hydrophilic group is an essential condition for dispersing inorganic oxide particles not subjected to surface treatment in the resin. Furthermore, if the resin is water-soluble, the resin can be dissolved in the aqueous dispersion of inorganic oxide particles, so that the inorganic oxide particles and the resin can be easily mixed uniformly in water. Then, by removing water after mixing, a transparent composite in which inorganic oxide particles are uniformly dispersed in the resin can be easily formed.

Examples of the water-soluble resin include acrylic-modified polyvinyl alcohol (PVA). Furthermore, while maintaining the water-solubility of acrylic-modified polyvinyl alcohol, it is modified (substituents of substituents) for high transparency, high strength, suppression of water-soluble state, improvement of water resistance after curing, control of change over time, etc. A modified product of acrylic modified polyvinyl alcohol introduced) is also used. These may be used alone or in combination of two.
Examples of the acrylic-modified polyvinyl alcohol include P-147, P-297, P-298 manufactured by Chukyo Yushi Co., Ltd.
Examples of the substituent introduced as a modified product of acrylic-modified polyvinyl alcohol include an amide group, an amino group, an alkoxyl group, a carboxyl group, a silyl group, a hydroxyl group, and a sulfoxide group.

In addition to the above, the hard coat film 23 may contain other inorganic oxide particles, resin monomers, and the like as long as the characteristics are not impaired.
Examples of the inorganic oxide particles other than the above include metal composite oxides such as antimony-added tin oxide (ATO) and tin-added indium oxide (ITO).

  As a characteristic of the hard coat film 23, the refractive index of the hard coat film in which the resin and the inorganic oxide particles are combined is set to increase by 0.2 or more with respect to the refractive index of the resin alone. This is because, as a function of the hard coat film 23, a high refractive index is required to prevent interference fringes between the plastic lens and the hard coat film 23, a hard coat for an antireflection film, or the like.

In the hard coat film 23, the visible light transmittance is preferably 90% or more, more preferably 95% or more.
This is because the function of the optical element provided with the hard coat film deteriorates when the transmission characteristics of the hard coat film deteriorate, but in the case of the hard coat film, an optical lens for a projector, an optical lens for pickup of an optical disk, etc. Therefore, since the reduction of the transmittance becomes a problem, it is set to 90%.
The visible light transmittance varies depending on the content of the inorganic oxide fine particles, and decreases as the content of the inorganic oxide fine particles increases. Therefore, it is not preferable to contain the inorganic oxide fine particles more than necessary.

"Method of manufacturing hard coat film"
Next, the manufacturing method of the hard coat film of the present invention will be described.
The method for producing an optical composite composition of the present invention comprises mixing inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, water, a resin having a hydrophilic group and having an acrylic group introduced therein. Then, a mixed solution is prepared, the mixed solution is applied onto a substrate to form a coating film, and water is removed from the coating film to produce the above hard coat film.
Specifically, the method for producing a hard coat film of the present invention is a method for preparing inorganic oxide particles prepared by dispersing the inorganic oxide fine particles in water so that the average dispersed particle size is 1 nm or more and 20 nm or less. An aqueous dispersion and a resin having a hydrophilic group and an acrylic group are mixed to prepare a mixed solution, and this mixed solution is applied onto a substrate to form a coating film. This is a method for producing the above hard coat film by removing water from the film.

  In this method for producing a hard coat film, the above-described resin having a hydrophilic group is used. Therefore, in order to uniformly disperse the inorganic oxide fine particles in the resin, a surface treatment agent for surface-treating the surface of the inorganic oxide fine particles. (Dispersant) need not be used. Further, only water is used as the solvent, and there is no need to use an organic solvent as in the conventional case.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

[Preparation of zirconia transparent dispersion, production of hard coat film]
Example 1
(Preparation of zirconia particles)
To a zirconium salt solution in which 2615 g of zirconium oxychloride octahydrate is dissolved in 40 L (liter) of pure water, dilute ammonia water in which 344 g of 28% ammonia water is dissolved in 20 L of pure water is added with stirring, and the zirconia precursor slurry is added. It was adjusted. Next, an aqueous sodium sulfate solution in which 300 g of sodium sulfate was dissolved in 5 L of pure water was added to this slurry with stirring. The amount of sodium sulfate added at this time was 30% by mass with respect to the zirconia-converted value of zirconium ions in the zirconium salt solution.
Next, this mixture was dried in the air at 130 ° C. for 24 hours using a dryer to obtain a solid.
Next, this solid material was pulverized with an automatic mortar and then baked in the air at 500 ° C. for 1 hour using an electric furnace.
Next, the fired product is put into pure water, stirred to form a slurry, washed using a centrifuge, and after sufficiently removing the added sodium sulfate, dried in a drier. Zirconia particles (A) were prepared.

(Preparation of zirconia aqueous dispersion)
Next, 70 g of water was added to 30 g of the zirconia particles (A) and mixed to prepare a zirconia aqueous dispersion (B).
Subsequently, the average dispersed particle diameter of the zirconia particles in this zirconia aqueous dispersion (B) was measured.
For the measurement of the average dispersed particle size of the zirconia particles, a dynamic light scattering particle size distribution analyzer (manufactured by Malvern) was used, and the content of zirconia particles in the zirconia aqueous dispersion (B) was adjusted to 1% by mass. This was used as a measurement sample.
As a result, the average dispersed particle diameter of the zirconia particles in the zirconia aqueous dispersion (B) was 6 nm.

(Preparation of zirconia transparent dispersion)
Next, 5 g of acrylic-modified polyvinyl alcohol resin (P-147, solid content 20 mass%, refractive index 1.52, manufactured by Chukyo Yushi Co., Ltd.) is added to 30 g of this zirconia aqueous dispersion (B) (solid content 30 mass%). And mixed to prepare a zirconia transparent dispersion (C).
When mixed in this amount, the zirconia content in the hard coat film after curing is 40% by volume. This is because, when the zirconia transparent dispersion (C) is cured, it can maintain the properties as a cured product. This is because the maximum content was 40% by volume.

(Preparation of hard coat film)
Next, this zirconia transparent dispersion (C) was applied on a PET film (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) by the doctor blade method, and then heated at 80 ° C. for 10 minutes in an electric furnace to remove water. Then, it was cured by irradiating ultraviolet rays with a high pressure mercury lamp to obtain a zirconia-containing hard coat film (D) having a thickness of 10 μm.
Next, the visible light transmittance of this zirconia-containing hard coat film (D) was measured using a spectrophotometer (manufactured by JASCO Corporation). As a result, when the transmittance of the PET film alone was 100%, the visible light transmittance was 92%.
Next, the refractive index of the zirconia-containing hard coat film (D) was measured.
A multi-angle ellipsometer (M-2000D, manufactured by JA Woollam Japan) was used for the measurement of the refractive index. As a result, the refractive index was 1.77.
Next, the hardness of the zirconia-containing hard coat film (D) was measured in accordance with Japanese Industrial Standard: JIS K 5600-5-4 “Mechanical properties of coating film—scratch hardness (pencil method)”. As a result, the hardness was H-2H.

"Example 2"
A zirconia aqueous dispersion (B) was prepared in the same manner as in Example 1.
(Preparation of zirconia transparent dispersion)
Next, 5 g of acrylic-modified polyvinyl alcohol resin (P-297, solid content 20 mass%, refractive index 1.52, manufactured by Chukyo Yushi Co., Ltd.) is added to 30 g of this zirconia aqueous dispersion (B) (solid content 30 mass%). And mixed to prepare a zirconia transparent dispersion (E). The molecular weight of the acrylic-modified polyvinyl alcohol resin (P-297) used in Example 2 is about twice the molecular weight of the acrylic-modified polyvinyl alcohol resin (P-147) used in Example 1.
When mixed in this amount, the zirconia content in the hard coat film after curing is 40% by volume. This is because, when the zirconia transparent dispersion (E) is cured, it can maintain the properties as a cured product. This is because the maximum content was 40% by volume.

(Preparation of hard coat film)
Next, this zirconia transparent dispersion (E) was applied on a PET film (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) by the doctor blade method, and then heated at 80 ° C. for 10 minutes in an electric furnace to remove water. Then, it was cured by irradiating ultraviolet rays with a high pressure mercury lamp to obtain a zirconia-containing hard coat film (F) having a thickness of 10 μm.
Next, the visible light transmittance of this zirconia-containing hard coat film (F) was measured using a spectrophotometer (manufactured by JASCO Corporation). As a result, when the transmittance of the PET film alone was 100%, the visible light transmittance was 91%.
Next, the refractive index of the zirconia-containing hard coat film (F) was measured.
A multi-angle ellipsometer (M-2000D, manufactured by JA Woollam Japan) was used for the measurement of the refractive index. As a result, the refractive index was 1.77.
Next, the hardness of the zirconia-containing hard coat film (F) was measured in accordance with Japanese Industrial Standard: JIS K 5600-5-4 “Mechanical properties of coating film—scratch hardness (pencil method)”. As a result, the hardness was about 2H.

"Comparative Example 1"
A zirconia aqueous dispersion (B) was prepared in the same manner as in Example 1.
(Preparation of zirconia transparent dispersion)
Next, 1 g of water-soluble polyvinyl alcohol resin (CP-1000, solid content of 100% by mass, manufactured by Kuraray Co., Ltd.) is added to 30 g of this zirconia aqueous dispersion (B) (solid content of 30% by mass) and mixed, and zirconia is transparently dispersed. Liquid (G) was prepared.
When mixed in this amount, the zirconia content in the zirconia-containing high refractive index film after curing is 40% by volume. This is because when the zirconia transparent dispersion (G) is cured, the properties as a cured product are obtained. This is because the maximum amount of zirconia that can be maintained was 40% by volume.

(Preparation of hard coat film)
Next, this zirconia transparent dispersion (G) was applied onto a PET film (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) by the doctor blade method, and then heated at 80 ° C. for 10 minutes in an electric furnace to remove water. And cured to obtain a zirconia-containing hard coat film (H) having a thickness of 10 μm.
Next, the visible light transmittance of this zirconia-containing hard coat film (H) was measured using a spectrophotometer (manufactured by JASCO Corporation). As a result, when the transmittance of the PET film alone was 100%, the visible light transmittance was 91%.
Next, the refractive index of the zirconia-containing hard coat film (H) was measured.
A multi-angle ellipsometer (M-2000D, manufactured by JA Woollam Japan) was used for the measurement of the refractive index. As a result, the refractive index was 1.74.
Next, the hardness of the zirconia-containing hard coat film (H) was measured in accordance with Japanese Industrial Standard: JIS K 5600-5-4 “Mechanical properties of coating film—scratch hardness (pencil method)”. As a result, the hardness was F to H.

"Comparative Example 2"
In the same manner as in Example 1, zirconia particles (A) were prepared.
(Preparation of zirconia dispersion)
Next, 24 g of the zirconia particles (A), 6 g of a silane coupling agent (KBM-3103C, manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface treatment agent, and 70 g of toluene were added and mixed to prepare a zirconia dispersion (I).
Subsequently, the average dispersed particle diameter of the zirconia particles in this zirconia dispersion (I) was measured.
For the measurement of the average dispersed particle size of the zirconia particles, a dynamic light scattering type particle size distribution measuring device (manufactured by Malvern) was used, and the content of zirconia particles in the zirconia dispersion liquid (I) was adjusted to 1% by mass. The sample was used as a measurement sample.
As a result, the average dispersed particle diameter of the zirconia particles in the zirconia dispersion (I) was 8 nm.

(Preparation of zirconia transparent dispersion)
Next, 30 g of this zirconia dispersion (I) (solid content: 30% by mass) was added to 1 g of acrylic resin (KAYARD DPHA, solid content: 100% by mass, manufactured by Nippon Kayaku Co., Ltd.), photopolymerization initiator (I-2959, Ciba). (Specialty Chemicals) 0.05g was added and mixed to prepare a zirconia transparent dispersion (J).
When mixed in this amount, the zirconia content in the hard coat film after curing is 40% by volume. This is because, when the zirconia transparent dispersion (J) is cured, it can maintain the properties as a cured product. This is because the maximum content was 40% by volume.

(Preparation of hard coat film)
Next, this zirconia transparent dispersion (J) was applied onto a PET film (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) by a doctor blade method, and then heated at 60 ° C. for 5 minutes in an electric furnace to volatilize toluene. The zirconia-containing hard coat film (K) having a thickness of 10 μm was obtained.
Next, the visible light transmittance of this zirconia-containing hard coat film (K) was measured using a spectrophotometer (manufactured by JASCO Corporation). As a result, when the transmittance of the PET film alone was 100%, the visible light transmittance was 90%.
Next, the refractive index of the zirconia-containing hard coat film (K) was measured.
A multi-angle ellipsometer (M-2000D, manufactured by JA Woollam Japan) was used for the measurement of the refractive index. As a result, the refractive index was 1.69.
Next, the hardness of the zirconia-containing hard coat film (K) was measured in accordance with Japanese Industrial Standard: JIS K 5600-5-4 “Mechanical properties of coating film—scratch hardness (pencil method)”. As a result, the hardness was H-2H.

“Comparative Example 3”
(Preparation of zirconia dispersion)
27 g of zirconia particles (RC-100, manufactured by Daiichi Rare Element Co., Ltd.), 3 g of a silane coupling agent (KBM-3103C, manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface modifier, and 70 g of toluene were added and mixed to obtain a zirconia dispersion (L ) Was prepared.
Subsequently, the average dispersed particle diameter of the zirconia particles in this zirconia dispersion (L) was measured.
For the measurement of the average dispersed particle size of the zirconia particles, a dynamic light scattering type particle size distribution measuring device (manufactured by Malvern) was used, and the content of zirconia particles in the zirconia dispersion liquid (L) was adjusted to 1% by mass. The sample was used as a measurement sample.
As a result, the average dispersed particle diameter of the zirconia particles in the zirconia dispersion (L) (including the surface treatment layer made of the surface treatment agent) was 40 nm.

(Preparation of zirconia transparent dispersion)
Next, 30 g of this zirconia dispersion (L) (solid content: 30% by mass) was added to 1 g of acrylic resin (KAYARD DPHA, solid content: 100% by mass, 1.51, manufactured by Nippon Kayaku Co., Ltd.), photopolymerization initiator (I -2959, manufactured by Ciba Specialty Chemicals) was added and mixed to prepare a zirconia transparent dispersion (M).
When mixed in this amount, the zirconia content in the composite after curing is 35% by volume (including the surface treatment agent). This is a cured product when the zirconia transparent dispersion (M) is cured. This is because the maximum amount of the zirconia content capable of maintaining the above characteristics was 35% by volume (including the surface treatment agent).

(Preparation of hard coat film)
Next, this zirconia transparent dispersion (K) was applied onto a PET film (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) by a doctor blade method, and then heated in an electric furnace at 60 ° C. for 5 minutes to volatilize toluene. The zirconia-containing hard coat film (N) having a thickness of 10 μm was obtained.
Next, the visible light transmittance of this zirconia-containing hard coat film (N) was measured using a spectrophotometer (manufactured by JASCO Corporation). As a result, when the transmittance of the PET film alone was 100%, the visible light transmittance was 61%.
Next, the refractive index of the zirconia-containing hard coat film (N) was measured.
A multi-angle ellipsometer (M-2000D, manufactured by JA Woollam Japan) was used for the measurement of the refractive index. As a result, the refractive index was 1.73.
Next, the hardness of the zirconia-containing hard coat film (N) was measured in accordance with Japanese Industrial Standard: JIS K 5600-5-4 “Mechanical properties of coating film—scratch hardness (pencil method)”. As a result, the hardness was H to 2H.
In Table 1, “visible light transmittance” is the transmittance of the PET film with a hard coat film relative to the transmittance of the PET film alone, and “○” indicates that the visible light transmittance is 90% or more. The case where the transmittance refractive index was less than 90% was defined as “x”.
“Refractive index difference” refers to the case where the refractive index increase Δ when containing zirconia is 0.2 or more with respect to a single resin, “◯”, and the refractive index increase Δ is less than 0.2. The case was set as “x”.
“Hardness” is an evaluation based on Japanese Industrial Standards: JIS K 5600-5-4 “Mechanical properties of coating film—scratch hardness (pencil method)”. , H or less was designated as “x”.

From the results in Table 1, it is confirmed that the hard coat films of Examples 1 and 2 are excellent in all the properties of visible light transmittance, refractive index increase and hardness, and can be sufficiently used as a high refractive index hard coat film. It was done.
On the other hand, it is confirmed that the hard coat films of Comparative Examples 1 to 3 are not sufficient as a high refractive index hard coat film because of insufficient properties of visible light transmittance, refractive index increase, and hardness. It was.

"Example 3"
(Optical function film)
As the optical functional film, an optical filter used for a plasma display panel (PDP) was used. This optical filter is provided by laminating an electromagnetic wave shielding layer, a color correction layer, and a near infrared light shielding layer on a PET substrate.
The hard coat layer of Example 1 was formed on the surface of the optical filter.
The thickness of the hard coat film and the film formation method were the same as in Example 1.
The adhesion between the hard coat film and the optical filter was good, and no peeling or bubbles were generated between the hard coat film and the optical filter.
About this optical filter with a hard coat film, visible light transmittance, reflectance and hardness were measured. Moreover, this measurement result (characteristic) was compared with the characteristic of the optical filter which provided the antireflection film on the surface by the conventional method.
As a result, in the optical filter with a hard coat film, a decrease in light amount and a deterioration in color balance due to the visible light transmittance of the hard coat film were not confirmed.
Moreover, in the optical filter with a hard coat film, there was no difference in the amount of reflection of external light, and it was confirmed that the hard coat film acts effectively as an antireflection film.
Moreover, the result of having measured the hardness of the hard coat film was H to 2H as in Example 1.
Therefore, it was shown that the high refractive index hard coat layer is effectively applied to the optical functional film.

Example 4
(Optical lens)
As the optical lens, a convex lens generally used for a projector or a magnifying glass was used. As the lens material, polymethyl methacrylate (PMMA, refractive index 1.49), which is an acrylic resin generally used for plastic optical lenses, was selected. The hard coat layer of Example 1 was formed on the lens surface.
The method was the same as Example 1 except that the method of forming the hard coat film was a dip coating method and the thickness of the hard coat film was 5 μm.
With respect to this optical lens with a hard coat film, the visible light transmittance, reflectance and hardness were measured. Further, the measurement results (characteristics) were compared with the characteristics of an optical lens in which a film made of titania sol was provided on the surface by a conventional method.
The hard coat film in this example had no peeling or bubbles. Moreover, the hardness of the film was H to 2H as in Example 1. And it was confirmed that this optical lens with a hard coat film has the same characteristics as a conventional lens material.

"Example 5"
(Lens for glasses)
Another example of the optical lens is a spectacle lens. The spectacle lens is made of a material having a higher refractive index than that of a normal optical lens in order to reduce the thickness of the lens itself and improve the appearance. Therefore, for the spectacle lens hard coat film, the difference in refractive index between the lens material and the high refractive hard coat film is small, and the high refractive hard coat film has scratch resistance, light resistance, temperature resistance, Adhesion is required. Therefore, although it does not satisfy the criteria for determining the hard coat film of the present application that the difference in refractive index between the lens material (base material) and the hard coat film is controlled sufficiently high (Δ0.2 or more), it is a high refractive index film. Since is not changed, it is described as an example.
A high refractive index acrylic material (refractive index 1.74) was selected as the lens material for spectacles, and the hard coat layer of Example 1 was formed on this surface.
The method was the same as Example 1 except that the method of forming the hard coat film was a dip coating method and the thickness of the hard coat film was 1.5 μm.
About this spectacle lens with a hard coat film, visible light transmittance, reflectance and hardness were measured. In addition, the measurement results (characteristics) were compared with the characteristics of a spectacle lens provided with a film made of titania sol on the surface by a conventional method.
As a result, it was confirmed that this spectacle lens with a hard coat film had the same characteristics as a conventional lens material.

  The hard coat film of the present invention comprises inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, and a resin having a hydrophilic group and having an acrylic group introduced therein. Since the surface of the film was not modified by the surface treatment agent, it was possible to maintain transparency and improve the refractive index and hardness. Various cameras such as video cameras, CD, CD-ROM, MD, CD-R, CD-Video, DVD and other optical pickups, copiers, printers and other OA equipment, as well as hard coat film The effect is also great in various industrial fields to which it is applied.

It is a schematic sectional drawing which shows one Embodiment of the optical lens of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical lens 20 Transparent base material 21 Base 22 Convex lens part 23 Hard-coat film

Claims (11)

  A hard coat film comprising inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less, and a resin having a hydrophilic group and an acrylic group introduced therein.   The hard coat film according to claim 1, wherein the resin is a water-soluble resin.   The hard coat film according to claim 2, wherein the water-soluble resin is acrylic modified polyvinyl alcohol and / or a modified product of acrylic modified polyvinyl alcohol.   The hard coat film according to any one of claims 1 to 3, wherein the inorganic oxide particles are made of zirconium oxide and / or titanium oxide.   An inorganic oxide particle having an average dispersed particle size of 1 nm or more and 20 nm or less, water, and a resin having a hydrophilic group and an acrylic group are mixed to prepare a mixed solution. A method for producing a hard coat film, comprising: coating on a material to form a coating film, and removing water from the coating film.   An aqueous dispersion in which inorganic oxide particles having an average dispersed particle diameter of 1 nm or more and 20 nm or less are dispersed in water and a resin having a hydrophilic group and an acrylic group are mixed to prepare a mixed solution. The method for producing a hard coat film according to claim 5, wherein the mixed solution is applied onto a substrate to form a coating film, and water is removed from the coating film.   The method for producing a hard coat film according to claim 5, wherein the resin is a water-soluble resin.   The method for producing a hard coat film according to claim 7, wherein the water-soluble resin is acrylic modified polyvinyl alcohol and / or a modified product of acrylic modified polyvinyl alcohol.   The method for producing a hard coat film according to claim 5, wherein the inorganic oxide particles are made of zirconium oxide and / or titanium oxide.   An optical functional film comprising the hard coat film according to any one of claims 1 to 4 at least in a light transmission region. An optical lens comprising the hard coat film according to any one of claims 1 to 4 at least in a light transmission region.

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