JP2008256881A - Antireflective film and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflective film, wherein the density of holes can be changed by forming a plurality of fine holes of which the density is gradually changed in the film thickness direction from one side surface of the film to the other side surface of the film, and to provide its manufacturing method. <P>SOLUTION: In the antireflective film 10, the plurality of holes 20 are formed so that the hole density is gradually changed from a dense density to a coarse density, toward a first surface 12 from a second surface 14. And the holes 20 are almost uniformly dispersed in a flat plane perpendicular to the film thickness direction. Further, on the second surface 14, recessed parts 21 are formed by opening parts of the holes 20, wherein the first surface 12 is a flat surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antireflection film and a method for producing the same. In particular, in an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), or a cathode ray tube display device (CRT), an antireflection film capable of preventing reflection of external light and reflection of an image. And a manufacturing method thereof.

  Optical materials having a low refractive index are used for antireflection films, optical waveguides, lenses, prisms, and the like. In particular, it is used in an image display device as an antireflection film for reducing reflection of external light and reflection of an image.

  Conventionally, various AG films and AR (LR) films have been developed as antireflection films. AG (anti-glare) film is coated with an anti-glare (anti-glare) layer on the film surface to form irregularities on the surface, and the reflected light is reflected on the irregularities on the surface to scatter, reflecting fluorescent lights and external light. Reduce the complexity.

In addition, an AR (antireflection) film and an LR (low reflection) film are coated with a low reflection layer having a different refractive index on the film surface, and reflected light cancels each other out due to light interference, thereby reducing the amount of reflected light. In general, it is a multilayer film in which materials having a high refractive index and materials having a low refractive index are alternately laminated. In Patent Document 1, a resin monomer is polymerized, or independent foam-like closed fine bubbles are dispersed in a transparent material made of a resin varnish to make the refractive index lower than the refractive index of the transparent material itself. An antireflection porous optical material has been proposed.
Japanese Patent No. 3549108

  However, although the conventional AG film is inexpensive, it scatters reflected light and scatters transmitted light, which causes a problem that an image is blurred in white. Further, the conventional AR film and LR film have a smooth surface and can obtain a high-definition image, but have a problem that the price is very high. In particular, it was necessary to use an expensive low-refractive index material for reducing the reflectivity for the AR film.

  The present invention has been made in order to solve the above-described problems, and has a plurality of minute holes in which the hole density is gradually changed in the film thickness direction from one film surface toward the other film surface. It aims at providing the formed film for antireflection and its manufacturing method.

The following invention is provided to solve the above-mentioned conventional problems.
The antireflection film according to the first aspect of the present invention comprises a hydrophobic organic polymer and an amphiphilic substance, and the pore density is gradually increased in the film thickness direction from one film surface toward the other film surface. It has a plurality of changed fine holes, and the refractive index is changed continuously or stepwise in the film thickness direction by gradually changing the hole density.

  When the antireflection film having such a configuration is used, the one having a higher hole density (the one having a lower refractive index) is usually disposed facing the display surface of the image display device. The reason for this is that, taking into account the difference in refractive index in the film thickness direction of the antireflection film, the surface of the image display device faces the high refractive index side of the antireflection film and refracts to the atmosphere on the atmosphere side. It is necessary to arrange the antireflective film having a lower refractive index facing the lower refractive index. By arranging in this way, reflection from the antireflection film can be reduced.

  For example, when it is used as an antireflection film, the one having a lower hole density is placed in contact with the surface of the image display device. Here, the definition of the difference in pore density is: [[pore density near one film surface] − [pore density near the other film surface] | / [pore density near one film surface and hole density near the other film surface] The larger value] × 100, and the unit is%. Here, the vicinity of one film surface means a range in which 20% of the entire film thickness enters the film thickness direction from one film surface, and the vicinity of the other film surface means the entire film thickness from the other film surface. It is the range that has entered the interior by 20%.

  Here, the hole density was determined from the number of holes per unit area from the results of film cross-sectional observation using a scanning electron microscope. When a part of the outline of the hole is applied to the measurement area of the hole density, both the case where it covers more than half of the outline of the hole cross section and the case where it is less than half of the outline of the hole cross section are 0.5 Decided to calculate. Calculation was made assuming that the entire outline of the hole was included.

  Thereby, the reflection of light can be reduced by changing the refractive index in the film thickness direction inside the film. Therefore, since the reflection of light occurs at the interface where the refractive index changes rapidly, for example, from the refractive index close to the refractive index of the glass substrate to the refractive index close to the refractive index of air, for preventing reflection of the glass substrate, An effective antireflection effect can be obtained by gradually changing the refractive index in the film thickness direction.

  Further, an inexpensive antireflection film can be produced with an inexpensive material without using an expensive low refractive index material.

  The antireflection film according to the second aspect of the present invention is the antireflection film according to the first aspect of the present invention, and has a recess formed by the opening of the hole on one of the film surfaces. It is characterized by.

  Thereby, fine unevenness | corrugation can be formed in the film | membrane surface and reflected light can be scattered.

  The antireflection film according to the third aspect of the present invention is the antireflection film according to the first or second aspect of the present invention, wherein the average pore diameter of the holes is 0.01 to 1.0 μm. Features.

  The antireflection film according to another aspect of the present invention is the antireflection film according to any one of the first to third aspects of the present invention, wherein the difference in pore density that is changed in the film thickness direction is 30% or more. It is characterized by being. By setting the difference in pore density to preferably 30% or more, and more preferably 50% or more, a sufficient difference in refractive index occurs in the film thickness direction, so that a desirable antireflection effect can be obtained.

  The method for producing an antireflection film according to the first aspect of the present invention comprises: (a) mixing and stirring a solution comprising at least a hydrophobic organic polymer, an amphiphilic substance, a hydrophilic solution, and a hydrophobic organic solvent. A step of generating a hydrophobic organic solvent solution in which reverse micelles are formed, and (b) applying the hydrophobic organic solvent solution generated in the step (a) on the substrate and then drying the substrate to reduce the pore density. And a step of forming a porous film having a plurality of minute pores gradually changed in the film thickness direction from the film surface toward the other film surface.

  Thereby, reflection of light can be reduced by gradually changing the refractive index in the film thickness direction inside the film. Further, an inexpensive antireflection film can be produced with an inexpensive material without using an expensive low refractive index material.

  The method for producing an antireflection film according to the second aspect of the present invention is the method for producing an antireflection film according to the first aspect of the present invention, wherein the substrate in the step (b) is a hydrophilic substrate. It is characterized by being.

  Thereby, the reverse micelle which has a hydrophobic group in the outermost layer repels the hydrophilic substrate, and the reverse micelle hardly exists in the vicinity of the hydrophilic substrate. Therefore, the pore density in the vicinity of the substrate decreases, and the pore density in the vicinity of the surface of the porous film that does not contact the substrate increases.

  The method for producing an antireflection film according to the third aspect of the present invention comprises (a) mixing and stirring a solution comprising at least a hydrophobic organic polymer, an amphiphile, a hydrophilic solution and a hydrophobic organic solvent. A step of generating a hydrophobic organic solvent solution in which reverse micelles are formed, and (c) applying the hydrophobic organic solvent solution generated in the step (a) on the substrate and then drying the substrate to reduce the pore density. Forming a porous film having a plurality of minute pores gradually changed in the film thickness direction from the film surface toward the other film surface, and forming the pores on the surface of the porous film in contact with the substrate And a step of forming a recess by the opening.

  Thereby, reflection of light can be reduced by gradually changing the refractive index in the film thickness direction inside the film. Further, an inexpensive antireflection film can be produced with an inexpensive material without using an expensive low refractive index material. In addition, fine irregularities can be formed on the film surface to scatter the reflected light.

  The method for producing an antireflection film according to the fourth aspect of the present invention is the method for producing an antireflection film according to the third aspect of the present invention, wherein the substrate in the step (c) is a hydrophobic substrate. It is characterized by being.

  Thereby, the reverse micelle having the hydrophobic group in the outermost layer is easily adsorbed on the hydrophobic substrate, and thus has a structure in which holes are arranged on the substrate side. As a result, when the film is peeled off from the substrate, a recess due to the opening of the hole is formed on the surface of the film that has been in contact with the substrate.

  The method for producing an antireflection film according to the fifth aspect of the present invention is the method for producing an antireflection film according to any one of the first to fourth aspects of the present invention, wherein the hydrophilic property in the step (a) is used. The specific gravity of the hydrophobic solution is smaller than the specific gravity of the hydrophobic organic solvent.

  Thereby, the specific gravity of a micelle becomes smaller than the surrounding organic solvent solution. Therefore, the pore density in the vicinity of the substrate decreases, and the pore density in the vicinity of the surface of the porous film that does not contact the substrate increases.

  The method for producing an antireflection film according to the sixth aspect of the present invention is the method for producing an antireflection film according to any one of the first to fifth aspects of the present invention, wherein the parents in the step (a) are as follows. A weight ratio (Rw = W1 / W2), which is a ratio of the weight (W1) of the hydrophilic solution to the weight (W2) of the medium, is 0.5 to 15.

  By setting the Rw to 0.5 or more, the formation of reverse micelles can be facilitated, and by setting the Rw to 15 or less, it is possible to effectively prevent the reverse micelles from irreversibly aggregating. In addition, the micelle diameter of the reverse micelle can be controlled. That is, the hole diameter can be controlled. Therefore, the hole diameter can be increased by increasing Rw, and the hole diameter can be decreased by decreasing Rw.

  According to the present invention, the reflection of light can be reduced by gradually changing the refractive index in the film thickness direction from one film surface to the other film surface. Further, an inexpensive antireflection film can be produced with an inexpensive material without using an expensive low refractive index material. In addition, fine irregularities can be formed on the film surface to scatter the reflected light.

  An embodiment of the present invention will be described with reference to the drawings. In addition, the embodiment described below is for explanation, and does not limit the scope of the present invention. Those skilled in the art can employ embodiments in which each or all of the embodiments described below are replaced with the same types of these elements, but these embodiments are also within the scope of the present invention. include.

  FIG. 1 is an example of a schematic cross-sectional view of an antireflection film according to an embodiment of the present invention. As shown in FIG. 1, the antireflection film 10 is bonded to the surface of the antireflection target substrate 50. Hereinafter, the surface of the antireflection film 10 bonded to the antireflection target substrate 50 side is referred to as a first surface 12, and the surface of the antireflection film 10 not bonded to the antireflection target substrate 50 side is referred to as a second surface 14.

  The antireflection film 10 has a film thickness direction from one film surface to the other film surface in the direction of film thickness, that is, in the direction from the second surface 14 to the first surface 12, from dense to sparse. A plurality of holes 20 are formed so as to gradually change in the direction. Moreover, in the plane perpendicular to the film thickness direction, the holes 20 are substantially uniformly distributed. Further, the second surface 14 has a recess 21 formed by the opening of the hole 20. The first surface 12 is a smooth surface.

Next, a method for manufacturing the above-described antireflection film 10 will be described.
Drawing 2 is a figure for explaining an example of the manufacturing method of the film for antireflection concerning one embodiment of the present invention. As shown in FIG. 2, first, a reverse organic micelle 45 having a hydrophilic solution 44 therein is prepared by mixing and stirring a hydrophobic organic polymer 41, an amphiphile 42, a hydrophobic organic solvent 43, and a hydrophilic solution 44. The hydrophobic organic solvent solution 40 in which is formed is generated ((1) in the figure).

  Specifically, first, the organic polymer 41, the amphiphilic substance 42, the hydrophobic organic solvent 43, and the hydrophilic solution 44 are put into a container. Here, the blending order of the organic polymer 41, the amphiphilic substance 42, the hydrophobic organic solvent 43, and the hydrophilic solution 44 is arbitrary. Then, the mixed solution is stirred in the container by a magnetic stirrer, a rotary blade, ultrasonic waves, or the like. In particular, fine and uniform reverse micelles 45 can be formed by stirring using ultrasonic waves.

  The weight ratio Rw (hydrophilic liquid / amphiphile) of the hydrophilic liquid 44 and the amphiphilic substance 42 is preferably 0.5 to 15 although it depends on the micelle diameter design of the reverse micelle 45. By setting Rw to 0.5 or more, reverse micelle formation can be facilitated, and by setting it to 15 or less, reverse micelles can be effectively prevented from irreversibly aggregating. Furthermore, the size of the reverse micelle formed in the hydrophobic organic solvent solution can be controlled within the above range. That is, when Rw is increased, the diameter of the reverse micelle is increased. On the other hand, by decreasing Rw, the diameter of the reverse micelle can be decreased.

  Further, the volume ratio Rs of the volume of the hydrophilic liquid 44 and the total volume of the organic polymer 41, the amphiphilic substance 42 and the hydrophilic solution 44 (hydrophilic liquid / (hydrophilic liquid + organic polymer + amphiphilic substance). ) Is preferably 0.05 to 0.4. Thereby, the density of a reverse micelle can be controlled. That is, when Rs is increased, the density of reverse micelles is increased. On the other hand, by decreasing Rs, the density of reverse micelles can be decreased.

  Next, the hydrophobic organic solvent solution 40 is applied on the substrate 60 and then dried to have a plurality of minute holes 20 that are gradually changed in the film thickness direction from one film surface toward the other film surface. The porous membrane 10 thus formed is formed ((2) in the figure). At this time, the concave portion 21 formed by the opening of the hole 20 is formed on the surface of the porous film 10 in contact with the substrate 60, that is, on the second surface 14.

  Here, using a coating machine such as a blade coater, the hydrophobic organic solvent solution 40 as the coating solution is applied onto the substrate 60 as the release film. Further, by blowing air to the hydrophobic organic solvent solution 40 applied on the substrate 60, the hydrophobic organic solvent 43 and the hydrophilic solution 44 are evaporated to form the holes 20.

  Further, when the porous organic film 10 is formed by evaporating the hydrophobic organic solvent 43 and the hydrophilic solution 44 from the hydrophobic organic solvent solution 40, it is preferable to first evaporate the hydrophobic organic solvent 43 selectively. Can be reliably formed. Therefore, it is desirable that the vapor pressure of the hydrophobic organic solvent 43 at the evaporation temperature of the hydrophobic organic solvent 43 and the hydrophilic solution 44 is higher than the vapor pressure of the hydrophilic solution 44.

  Further, the specific gravity of the hydrophobic organic solvent 43 can be used to control the vertical formation position of the holes 20 in the porous film 20 to be formed.

  In general, when it is desired to uniformly distribute the pores 20 in the porous membrane 20, it is desirable to use a nonpolar solvent. On the other hand, when water is used as the hydrophilic solution 44, for example, if a specific gravity such as chloroform is larger than that of water, the reverse micelles 45 can be distributed in a large amount upward, while the aliphatic carbonization is performed. When the specific gravity such as hydrogen or aromatic hydrocarbon is smaller than that of water, the reverse micelle 45 can be distributed in a large amount downward.

  When many reverse micelles 45 are distributed upward, the specific gravity of the organic polymer 41 is larger than the specific gravity of water except for some polyolefins such as polyethylene and polypropylene. It is also possible to use an organic solvent smaller than the specific gravity of water.

  Specific examples of the specific gravity of the hydrophobic organic solvent 43 larger than that of water include dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1,2 dichloroethylene. Chlorinated solvents such as trichloroethylene; carbon disulfide, and specific examples of hydrophobic organic solvents whose specific gravity is lighter than water include normal pentane normal hexane, cyclohexane, benzene, toluene, xylene, etc. It is done.

  These hydrophobic organic solvents 43 can be used alone, or a mixed solvent can be used when these solvents are combined to form a uniform solution.

  Further, by using a hydrophilic substrate as the substrate 60, it is possible to control the formation position in the vertical direction of the holes 20 in the porous film 20 to be formed. The reverse micelle 45 having the hydrophobic group in the outermost layer repels the hydrophilic substrate, and the reverse micelle 45 is unlikely to exist in the vicinity of the hydrophilic substrate. Therefore, many reverse micelles 45 can be distributed upward.

  In addition, by using a hydrophobic substrate as the substrate 60, it is possible to form the recess 21 by the opening of the hole 20 on the second surface 14 of the porous film 10 in contact with the substrate 60. The reverse micelle 45 having the hydrophobic group in the outermost layer is easily adsorbed on the hydrophobic substrate, and thus has a structure in which the holes 20 are arranged on the substrate side. As a result, when the film is peeled from the substrate, a recess 21 is formed by the opening of the hole 20 on the second surface 14 that has been in contact with the substrate.

  Finally, the porous film 10 peeled from the substrate 60 becomes the antireflection film 10 ((3) in the figure).

  Examples of the organic polymer 41 include olefin polymers such as polyethylene, polypropylene, poly-4-methylpentene-1, and cyclopolyolefin; polyvinyl chloride, polyvinylidene chloride chlorine resin polymer; polyalkylene oxide; polyvinyl alcohol, ethylene vinyl. Alcohol resins such as alcohol copolymer resins; Styrene resins such as polystyrene, acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin); Acrylic resins such as methacrylate ester resin and acrylate ester resin Resin; polyamide resin (polyamide 6, polyamide 46, polyamide 66, etc.), polyacetal, polycarbonate, modified polyphenylene ether, thermoplastic polyester resin (polyethylene Phthalate, at least one or more can be mentioned selected from engineering plastics polyethylene naphthalate) and the like.

  In addition, organic polymers such as polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl acetate, cellulose plastics, thermoplastic elastomers such as thermoplastic elastomers, polyphenylene sulfide, polysulfone, amorphous polyarylate, polyetherimide, poly Ether sulfone, polyether ketone, polyether ether ketone, liquid crystal polyester, polyamideimide, polyimide and the like can also be used.

  Among these, polystyrene, the acrylic resin, polycarbonate, cyclopolyolefin, fluororesin from the viewpoint of transparency, and polyamide and polyimide are preferable from the viewpoint of heat resistance from the viewpoint of cost.

The amphiphilic substance 42 is not particularly limited as long as it has a hydrophobic group and a hydrophilic group, and may be a polymer amphiphilic substance or an amphiphilic substance other than a polymer. Examples of the anion constituting the hydrophilic group in the ionic amphiphile include —COO ⁻ and —SO ₄ ^— , and examples of the cation include dimethylammonium ion, trimethylammonium ion and pyridinium ion. In addition, examples of the hydrophilic group in the nonionic amphiphile include a hydroxyl group and an ether bond. The presence of the amphiphilic substance in the multilayer structure of the present invention can be confirmed by observation using an energy dispersive X-ray fluorescence analyzer.

  Specific examples of the amphiphilic substance 42 include bis (2-ethylhexylsulfosuccinate sodium) (shown by the following chemical formula 1, sometimes referred to as AOT hereinafter), dioctylsulfosuccinate sodium, diisobutylsulfosuccinate sodium, dicyclohexylsulfosuccinate. Sodium ion, sodium dihexylsulfosuccinate, polyion complex of dihexadecyldimethylammonium and polystyrenesulfonic acid (shown by the following chemical formula 2, hereinafter sometimes referred to as PIC), block copolymer obtained from ethylene glycol and propylene glycol, ethylene Examples thereof include at least one selected from block copolymers obtained from oxide and propylene oxide.

  The PIC can be obtained as a purified product by, for example, drying and recrystallizing a white precipitate produced by reacting an ultrasonic dispersion of dihexadecyldimethylammonium bromide with an aqueous solution of sodium polystyrene sulfonate. Here, n in Chemical Formula 2 is an integer of about 300 to 500.

また、本発明で使用可能な疎水性有機溶媒４３としては、表１に示す、２０℃における誘電率が５以下であるノルマルペンタン、ノルマルヘキサン、シクロヘキサン、イソオクタン、ノルマルヘプタン、ノルマルデカン、ベンゼン、トルエン、エチルベンゼン、オルソキシレン、メタキシレン、パラキシレン、混合キシレン、四塩化炭素、クロロホルム、及びトランス１、２、−ジクロロエチレン、並びに表２に示す、２０℃における誘電率が５を越える、酢酸ブチル、ジクロロメタン、１、１、２、２−テトラクロロルエタン、シス１、２−ジクロロエタン、及びイソブチルメチルケトンまたはこれらの混合物が例示できるが、本発明で使用可能な疎水性有機溶媒はこれらに限定されるものではない。疎水性有機溶媒は、有機ポリマーの溶解能が高く、水の溶解度が低く、蒸気圧が高いことが好ましく、さらに実用性の観点から化学的に安定で、毒性が低いことが好ましい観点から、好ましい溶媒として、トルエン、クロロホルムが例示できる。

Moreover, as the hydrophobic organic solvent 43 that can be used in the present invention, normal pentane, normal hexane, cyclohexane, isooctane, normal heptane, normal decane, benzene, toluene having a dielectric constant of 5 or less at 20 ° C. shown in Table 1 are used. , Ethylbenzene, ortho-xylene, meta-xylene, para-xylene, mixed xylene, carbon tetrachloride, chloroform, and trans 1,2, -dichloroethylene, and butyl acetate and dichloromethane whose dielectric constant at 20 ° C. exceeds 5 as shown in Table 2 Examples include 1,1,2,2-tetrachloroluethane, cis 1,2-dichloroethane, and isobutyl methyl ketone, or mixtures thereof, but the hydrophobic organic solvents that can be used in the present invention are limited to these. It is not a thing. Hydrophobic organic solvents are preferred from the viewpoint that organic polymers have high solubility, low water solubility, and high vapor pressure, and are chemically stable from the viewpoint of practicality and preferably have low toxicity. Examples of the solvent include toluene and chloroform.

また、逆ミセル４５を形成する際に使用する親水性液体４４として、水の使用がもっとも好ましいが、本発明において両親媒性物質、有機ポリマー、疎水性有機溶媒及び親水性液体からなる疎水性有機溶媒を撹拌して、疎水性有機溶媒溶液中で逆ミセルを形成するものであれば、水以外の親水性液体、又は水に水以外の親水性液体を配合して、親水性液体の比重、蒸気圧、溶解性等を調整することが可能である。水以外の親水性液体として、メタノール、エタノール、エチレングリコール、プロピレングリコール、ギ酸等が例示できる。

Further, water is most preferably used as the hydrophilic liquid 44 used in forming the reverse micelle 45, but in the present invention, a hydrophobic organic material comprising an amphiphilic substance, an organic polymer, a hydrophobic organic solvent, and a hydrophilic liquid. If the solvent is stirred to form reverse micelles in a hydrophobic organic solvent solution, a hydrophilic liquid other than water, or a hydrophilic liquid other than water is blended in water, the specific gravity of the hydrophilic liquid, Vapor pressure, solubility, etc. can be adjusted. Examples of hydrophilic liquids other than water include methanol, ethanol, ethylene glycol, propylene glycol, and formic acid.

  Examples of the hydrophobic substrate used in the present invention include glass substrates, metal substrates, inorganic substrates such as ceramics, plastic substrates, wood, paper, reinforced plastic substrates, enamel substrates, water glass substrates, and the like.

  Plastic substrates include polyolefins such as polypropylene and polyethylene, polyester resins such as polyethylene terephthalate, polymethyl methacrylate resins, fluororesins such as polyfluorinated ethylene, polyetherketone, polystyrene, ABS resin, polycarbonate, urethane resin, and vinyl chloride resin. And thermosetting or thermoplastic plastics such as epoxy resins, phenol resins, vinyl ester resins, and fiber reinforced plastics obtained by reinforcing these plastics with inorganic or organic fibers.

  Examples of the metal substrate include aluminum, aluminum alloy, copper, zinc, iron, and steel (such as galvanized steel and stainless steel). Examples of the glass substrate include quartz glass, sodium glass, and alkali-free glass. Examples of the inorganic substrate include alumina, zirconia, silicon carbide, and silicon nitride. The substrate surface may be coated with a cured film of acrylic, alkyd, polyester, urethane, phenol, or melamine resin.

  The hydrophilic substrate used in the present invention includes polyvinyl alcohol, polyacrylic acid and salts thereof, polyester polyol, polyurethane polyol, polyacrylic acids and salts thereof, vinyl acetate-maleic acid copolymers, styrene-maleic acid. Acid copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate homopolymers and copolymers, hydroxypropyl acrylate homopolymers And copolymers, homopolymers and copolymers of hydroxybutyl methacrylate, hydroxybutyl methacrylate Homopolymers and copolymers such as the relations are exemplified. As the hydrophilic substrate, an organosiloxane polymer compound having a hydrophilic group, a quartz substrate, a glass substrate, or the like can be used.

  Among the above-mentioned substrates, at least one selected from glass, metal, ceramics, polypropylene, polyethylene, polyethylene terephthalate, polymethyl methacrylate resin, polyfluorinated ethylene, polyether ketone, polyvinyl alcohol, polyacrylic acid, or these A composite substrate can be suitably used in the present invention.

  Next, several preferred embodiments of the present invention will be described.

Example 1
In Example 1, 1.08 g of polystyrene as an organic polymer and 0.12 g of an amphiphilic substance AOT are mixed, this mixture is dissolved in 6 ml of toluene, 0.3 ml of water is further added, and ultrasonic dispersion is performed for 5 minutes. A coating solution in which reverse micelles were formed was prepared.

  This coating solution was applied to a PVA (polyvinyl alcohol) substrate to a thickness of 300 μm using a blade coater, and dried air (temperature 25 ° C., relative humidity 17%) was applied at a flow rate of 1 L / min. The organic solvent was dried by blowing air to produce a porous film on the PVA substrate.

The thickness of the porous film obtained using a transmission electron microscope was 19.9 μm, the average pore diameter was 0.29 μm, and the pore density near the film surface was 23.2 / 100 μm ² , from the film surface to the vicinity of the substrate. Shows a tendency for the pore density to gradually decrease, and the pore density near the substrate was 9.6 / 100 μm ² . When this film was measured for spectral reflectance at an incident angle of 5 ° in the wavelength region of 380 to 780 nm using a spectrophotometer, the average reflectance at 450 to 650 nm was 1.3%.

(Example 2)
In Example 2, 1.08 g of polystyrene as an organic polymer and 0.12 g of an amphiphilic substance AOT were mixed, this mixture was dissolved in 6 ml of toluene, and 0.05 ml of water and 0.25 ml of methanol were further added. A coating solution in which reverse micelles were formed was prepared by ultrasonic dispersion for minutes.

  This coating solution was applied to a PET (polyethylene terephthalate) substrate to a thickness of 300 μm using a blade coater, and dry air (temperature 25 ° C., relative humidity 17%) was applied at a flow rate of 1 L / min. And the organic solvent was dried to produce a porous film on the PET substrate.

The thickness of the porous film obtained using a transmission electron microscope was 22.4 μm, the average pore diameter was 0.37 μm, the pore density near the membrane surface was 50.8 / 100 μm ² , and the pore density near the substrate was 31 2/100 μm ² . When this film was measured for spectral reflectance at an incident angle of 5 ° in the wavelength region of 380 to 780 nm using a spectrophotometer, the average reflectance at 450 to 650 nm was 1.8%.

(Example 3)
In Example 3, 1.08 g of polystyrene as an organic polymer and 0.12 g of an amphiphilic substance AOT are mixed, this mixture is dissolved in 6 ml of chloroform, 0.3 ml of water is further added, and ultrasonic dispersion is performed for 5 minutes. A coating solution in which reverse micelles were formed was prepared.

  This coating solution was applied to a PET substrate to a thickness of 300 μm using a blade coater, and dry air (temperature 25 ° C., relative humidity 17%) was applied at a flow rate of 1 L / min. And the organic solvent was dried to produce a porous film on the PET substrate.

The thickness of the porous film obtained using a transmission electron microscope was 17.2 μm, the average pore diameter was 0.26 μm, the pore density near the membrane surface was 95.2 / 100 μm ² , and the pore density near the substrate was 23 2/100 μm ² . When this film was measured for spectral reflectance at an incident angle of 5 ° in the wavelength region of 380 to 780 nm using a spectrophotometer, the average reflectance at 450 to 650 nm was 1.2%.

Example 4
In Example 4, 1.08 g of polystyrene as an organic polymer and 0.12 g of an amphiphilic substance AOT are mixed, this mixture is dissolved in 6 ml of toluene, and further 0.3 ml of water is added and ultrasonically dispersed for 5 minutes. A coating solution in which reverse micelles were formed was prepared.

  This coating solution was applied to a PET substrate to a thickness of 300 μm using a blade coater, and dry air (temperature 25 ° C., relative humidity 17%) was applied at a flow rate of 1 L / min. And the organic solvent was dried to produce a porous film on the PET substrate.

The thickness of the porous film obtained using a transmission electron microscope was 21.0 μm, the average pore diameter was 0.37 μm, the pore density near the membrane surface was 11.2 / 100 μm ² , and the pore density near the substrate was 25 2/100 μm ² . Moreover, when this film was immersed in ethanol and peeled from the substrate, an opening having an average pore diameter of 0.34 μm was found on the back surface of the film (the surface that was in contact with the substrate). When this film was measured for spectral reflectance at an incident angle of 5 ° in the wavelength region of 380 to 780 nm using a spectrophotometer, the average reflectance at 450 to 650 nm was 0.5%.

(Comparative Example 1)
In Comparative Example 1, 1.08 g of polystyrene as an organic polymer and 0.12 g of the amphiphilic substance AOT were mixed, this mixture was dissolved in 6 ml of toluene, and ultrasonically dispersed for 5 minutes to prepare a coating solution.

  This coating solution was applied to a PET substrate to a thickness of 300 μm using a blade coater, and dry air (temperature 25 ° C., relative humidity 17%) was applied at a flow rate of 1 L / min. The organic solvent was dried by blowing and the film produced on the PET substrate was observed with a transmission electron microscope. As a result, no porous structure was found inside the film. When this film was measured for spectral reflectance at an incident angle of 5 ° in the wavelength range of 380 to 780 nm using a spectrophotometer, the average reflectance at 450 to 650 nm was 4.8%.

(Comparative Example 2)
In Comparative Example 2, 1.08 g of polystyrene as an organic polymer and 0.01 g of an amphiphilic substance AOT are mixed, this mixture is dissolved in 6 ml of toluene, 0.3 ml of water is further added, and ultrasonic dispersion is performed for 5 minutes. A coating solution in which reverse micelles were formed was prepared.

  This coating solution was applied to a PET substrate to a thickness of 300 μm using a blade coater, and dry air (temperature 25 ° C., relative humidity 17%) was applied at a flow rate of 1 L / min. And the organic solvent was dried to produce a porous film on the PET substrate.

The thickness of the porous film obtained using a transmission electron microscope was 18.7 μm, the average pore diameter was 4.31 μm, the pore density near the membrane surface was 12.8 / 100 μm ² , and the pore density near the substrate was 23 2/100 μm ² . When this film was measured for spectral reflectance at an incident angle of 5 ° in the wavelength region of 380 to 780 nm using a spectrophotometer, the average reflectance at 450 to 650 nm was 3.8%. Thereby, when the hole diameter of the hole was too large, it turned out that an average reflectance does not fall.

  According to Examples 1 to 4 and Comparative Example 1, it was found that the average reflectance is decreased by dispersing the holes so as to change in the film thickness direction.

  In addition, it was found from Examples 1 to 4 and Comparative Example 2 that the average reflectance is decreased by making the hole diameter minute (1 μm or less).

  In FIG. 1 and FIG. 2 described above, the second surface 14 of the antireflection film 10 that is a porous film forms a recess 21 by the opening of the hole 20, but in the present invention, a smooth surface is formed. It may be.

It is an example of the schematic cross section of the film for reflection prevention concerning one Embodiment of this invention. It is a figure for demonstrating an example of the manufacturing method of the film for reflection prevention concerning one Embodiment of this invention.

Explanation of symbols

10 Antireflection film (porous film)
12 First surface 14 Second surface 20 Hole 21 Recess 50 Antireflection target substrate

Claims (9)

In an antireflection film comprising a hydrophobic organic polymer and an amphiphile,
The antireflection film, wherein the antireflection film has a plurality of minute holes, and the density of the holes is gradually changed in the film thickness direction from one film surface to the other film surface.   2. The antireflection film according to claim 1, wherein a concave portion formed by the opening of the hole is formed on one of the film surfaces.   The average hole diameter of the said hole is 0.01-1.0 micrometer, The film for reflection prevention of Claim 1 or 2 characterized by the above-mentioned. (A) a step of mixing and stirring a solution comprising at least a hydrophobic organic polymer, an amphiphilic substance, a hydrophilic solution and a hydrophobic organic solvent to produce a hydrophobic organic solvent solution in which reverse micelles are formed;
(B) The hydrophobic organic solvent solution generated in the step (a) is applied on the substrate and then dried, and the pore density is gradually changed in the film thickness direction from one film surface to the other film surface. Forming a porous film having a plurality of minute pores, and
A method for producing an antireflection film, comprising:   The method for producing an antireflection film according to claim 4, wherein the substrate in the step (b) is a hydrophilic substrate. (A) a step of mixing and stirring a solution comprising at least a hydrophobic organic polymer, an amphiphilic substance, a hydrophilic solution and a hydrophobic organic solvent to produce a hydrophobic organic solvent solution in which reverse micelles are formed;
(C) The hydrophobic organic solvent solution produced in the step (a) is applied on a substrate and then dried, and the pore density is gradually changed in the film thickness direction from one film surface to the other film surface. Forming a porous film having a plurality of microscopic holes, and forming a recess by an opening of the hole on the surface of the porous film in contact with the substrate;
A method for producing an antireflection film, comprising:   The method for producing an antireflection film according to claim 6, wherein the substrate in the step (c) is a hydrophobic substrate.   The method for producing an antireflection film according to any one of claims 4 to 7, wherein the specific gravity of the hydrophilic solution in the step (a) is smaller than the specific gravity of the hydrophobic organic solvent.   The weight ratio (Rw = W1 / W2), which is the ratio of the weight (W1) of the hydrophilic solution to the weight (W2) of the amphiphile in the step (a), is 0.5 to 15. The manufacturing method of the film for antireflection of any one of Claim 4 to 8 characterized by the above-mentioned.

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