JPH08313702A - Antireflection body and its production - Google Patents

Abstract

PURPOSE: To provide antireflection body having an antireflection effect by carrying out a polymn. reaction on a substrate without, requiring complicated operation for synthesis. CONSTITUTION: A coating film of a fluorine compd. is formed on at least one side of a substrate such as a film by allowing a fluorine compd. having at least one isocyanato group in one molecule to react with a compd. having a functional group which reacts with the isocyanato group. Since a low refractive index layer as the coating film is formed on the substrate, the reflection of outdoor daylight can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection body having an antireflection property due to light interference of a thin film for preventing reflection on the substrate surface by external light, fluorescent light or the like.

[0002]

2. Description of the Related Art As a method for forming an antireflection layer on a substrate, for example, a vapor deposition method, a coating method and the like can be mentioned.
The evaporation method is one layer of a low refractive index material such as MgF ₂ or SiO ₂ on the substrate, or TiO ₂ or Zr from the substrate side.
The antireflection property is imparted by laminating a plurality of layers of a substance having a high refractive index such as O ₂ and a substance having a low refractive index such as MgF ₂ or SiO ₂ and a thin film having a predetermined thickness formed by vacuum vapor deposition. is there. Here, the predetermined film thickness is a thickness required to exert an antireflection effect by interference of the thin film,
For example, when antireflection is performed by one layer, it is most preferable that the thickness thereof be ¼ of the wavelength of the light incident on the film, specifically about 0.1 μm. It is preferable. However, since the cost is high in the case of the vapor deposition method, an inexpensive coating method is required. In addition, the coating method dissolves or disperses a metal alkoxide, a fluoropolymer or the like in an appropriate solvent, and coats the substrate with a single layer or a plurality of layers to give an antireflection property so that a predetermined film thickness is obtained. To do.

When the antireflection layer is formed as a single layer on the substrate, the lower the refractive index of the antireflection layer is, the better, for example,
When the refractive index of the substrate is 1.50 to 1.70, the refractive index of the antireflection layer is preferably 1.45 to 1.20, more preferably 1.35 to 1.25. As a compound forming such a thin film having a low refractive index, for example, TE
FLON AF (made by DuPont, refractive index 1.30), CY
TOP (made by Asahi Glass, refractive index 1.35), 17FM (made by Mitsubishi Rayon, refractive index 1.34), etc. are mentioned. In order to obtain an antireflection film using these fluoropolymers, these fluoropolymers are dissolved in a solvent capable of dissolving them to form a solution, and this is applied onto the film to a predetermined film thickness at the time of film formation. After that, it can be obtained by removing the solvent.

However, conventionally, when the above-mentioned fluoropolymer is used, first, an apparatus for synthesizing the fluoropolymer, and in the synthetic reaction, addition of reagents, control of reaction temperature, reaction rate, post-treatment after reaction, production Various processes such as product refining are required, which requires great cost and labor. Further, forming the antireflective fluorine compound layer by carrying out the reaction on the substrate makes it very important to control the reaction so as to obtain a fluorine compound having a refractive index and a film thickness necessary for exhibiting the antireflective property. In many cases, it is difficult to obtain, and because it is a thin film, it is easily affected by oxygen, the polymerization reaction is suppressed, and it is difficult to form a polymer. Thus, the antireflection body obtained in this way is not known.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an antireflective body having an antireflective effect by forming a film of a fluorine compound by a reaction on a substrate, which has hitherto been considered difficult, and having the antireflection effect by the film of the fluorine compound. It is provided.

[0006]

Means for Solving the Problems As a result of intensive investigations on the above problems, a fluorine compound having at least one isocyanate group in one molecule on a substrate and a compound having a functional group capable of reacting with the isocyanate group have been identified. The present invention has been newly found out that it reacts under mild conditions to form a film of a fluorine compound, and the film of the resulting fluorine compound has a property of sufficiently functioning as an antireflection film in practice. . That is, the present invention has excellent antireflection properties and excellent productivity (1) a fluorine compound having at least one isocyanate group in one molecule on at least one surface of a substrate, and a functional group reactive with the isocyanate group. An antireflective body characterized by being coated with a film of a fluorine compound produced by reaction with a compound having
(2) The antireflection body of (1), wherein the substrate is a film,
(3) The antireflection body of (2), wherein the film is an optical film, and (4) the optical film is a polarizing film, a retardation film, a light condensing film or a light diffusing film (3).
An antireflection body of (2), wherein the film is a cover film for a display body (2), and (6) a fluorine compound having at least one isocyanate group in one molecule on at least one surface of the substrate. The present invention relates to a method for producing an antireflection body, which comprises reacting a compound having a functional group that reacts with an isocyanate group to form a film of a fluorine compound.

The fluorine compound having at least one isocyanate group in one molecule used for forming the above antireflection layer, and the compound reacted therewith are
Any substance can be used as long as the substrate reacts under a reaction condition that does not cause deterioration, discoloration, etc., the fluorine compound formed after the reaction forms a film, and has a refractive index sufficient to exert an antireflection effect. May be. As the fluorine compound having at least one isocyanate group in one molecule, a polymer having an average molecular weight of 100 or more, preferably 500 to 20.
A polymer of about 000 is preferable, for example, F in which two aromatic isocyanate groups are introduced into perfluoropolyether obtained by polymerizing tetrafluoroethylene and oxygen by a photochemical reaction.
OMBLIN Z DISOC (made by Ausimont), F
LUOROLINK B (fluorine content 54%: made by Ausimont) and the like can be mentioned.

The compound to be polymerized with a fluorine compound having at least one isocyanate group in one molecule is preferably a compound having a functional group capable of reacting with an isocyanate group such as an amino group, a hydroxyl group and a carboxyl group. For example, methylamine, ethylamine,
Alkylamines such as dimethylamine, diethylamine and methylethylamine, alkylenediamines such as ethylenediamine, alkylaminoalkylamines such as methylaminoethylamine, aromatic amines such as aniline and ethylaniline, water, methanol, ethanol, ethylene glycol, polyethylene glycol, etc. Examples thereof include aliphatic alcohols, aromatic alcohols such as phenol and resorcinol, fatty acids such as acetic acid and propionic acid, oxyacids such as lactic acid and citric acid, aromatic carboxylic acids such as phthalic acid, and amino acids. More preferably, a fluorine compound having a functional group such as an amino group, a hydroxyl group or a carboxyl group is preferable in order to reduce the compatibility with the fluorine compound having an isocyanate group and the refractive index of the generated fluorine compound. As such a compound, FOMB obtained by introducing four hydroxyl groups into perfluoropolyether obtained by polymerizing ethylene tetrafluoride and oxygen by a photochemical reaction.
LIN Z TETRAOL (made by Ausimont), FL
UORLINK T (average molecular weight 2300: fluorine content 58%: made by Ausimont) FOMBLIN Z DOL (average molecular weight 20 with two hydroxyl groups introduced
00: made by Ausimont), FLUORLINK D
(Average molecular weight 2000: fluorine content 62%: made by Ausimont), FLUOROLLINKE (average molecular weight 210
0: made by Ausimont) FOMBLIN Z DIAC (average molecular weight 200) in which two carboxyl groups are introduced.
0: made by Ausimont) and the like.

In the present invention, in order to form an antireflection layer on the surface of a substrate, the above compounds are diluted alone or in a mixture with a solvent to an appropriate concentration, and then coated on the substrate and then the solvent is used. And heat treatment (for example, 40 to 200 ° C.) and moist heat treatment (for example, 30 to 100 ° C. and humidity 30 to 95%) under conditions that do not cause deterioration or discoloration of the substrate to complete the polymerization reaction. be able to. In addition, after coating one of the isocyanate compound and the compound having a functional group, the other may be coated and reacted. The use ratio of both is not particularly limited as long as a film of a fluorine compound is formed after the reaction,
For example, as the isocyanated fluorine compound, FOMBL
IN Z DISOC, F as a compound having a functional group
When OMBLIN Z TETRAOL is used, the former is preferably 1 to 100 parts by weight, more preferably 2 to 50 parts by weight, still more preferably 3 to 20 parts by weight, relative to 1 part by weight of the latter.

It is also possible to add a catalyst to accelerate the reaction rate. As the catalyst, an organometallic compound is preferably used, and more preferably, an organotin compound such as di-n-butyltin (IV) dilaurate is used. The amount used is not particularly limited as long as a film is formed. For example, 80 parts by weight of FOMBLIN Z DISOC as the isocyanated fluorine compound and FOMBLIN Z TETRA as the compound having a functional group are used.
When 20 parts by weight of OL is used, di-n-butyltin (IV) dilaurate is preferably used as a catalyst in an amount of 0.001-10.
The amount is preferably 0.005 to 10 parts by weight, more preferably 0.01 to 1 part by weight.

In the present invention, the method of applying the above compound to the surface of the substrate is not particularly limited, and examples thereof include a dip coating method, a gravure coating method, a lip coating method, a spin coating method, a roll coating method and a spray coating method. Can be mentioned. However, the lip coating method or the dip coating method is preferable in terms of productivity and the need to control the film thickness to about 0.1 μm in order to exhibit sufficient antireflection property.

In the present invention, in order to enhance the antireflection function of the substrate, it is possible to form a high refractive index layer between the substrate and the low refractive index layer formed of the fluorine compound produced by the reaction. Examples of the high refractive index layer include those formed by depositing a metal oxide such as TiO ₂ or ZrO ₂ to a predetermined thickness by a vapor deposition method or a coating method. Further, in order to improve the adhesion of the antireflection layer, it is possible to apply it on a film which has been treated with a primer.

In the present invention, the substrate is not particularly limited as long as it requires antireflection, and its material is, for example, a glass plate, a metal plate (foil), a plastic plate,
Examples include plastic films. Examples of plastics include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polystyrene, polyurethane, vinyl chloride, acrylic resins, polycarbonate resins, acrylate resins and the like. Further, it can be used for a plastic film whose surface is subjected to various treatments such as prism processing, Fresnel lens processing, or embossing.

In the present invention, suitable examples of the substrate include a polarizing film, a retardation film, a light condensing film,
Examples thereof include an optical film such as a light diffusion film and a cover film for a display.

As the polarizing film, for example, after a film of polyvinyl alcohol or the like is stretched, iodine,
A polarizing element is formed by a method of dyeing with a dichroic dye, or a method of dyeing with iodine or a dichroic dye and then stretching.
Further, those in which a protective layer is formed of triacetyl cellulose, acrylic resin, polycarbonate resin or the like can be mentioned. Further, the polarizing film may have a surface subjected to fine unevenness treatment (non-glare treatment), or may have a hard coat layer such as a silicone type or acrylic type formed thereon.

Examples of the retardation film include those obtained by stretching a film of polyvinyl alcohol, polycarbonate or the like. Also, the retardation film,
A protective layer such as triacetyl cellulose, acrylic resin or polycarbonate resin may be formed.

Examples of the light condensing film include a transparent plastic film having a plurality of prisms arranged in parallel on the surface thereof.

Examples of the light diffusing film include a transparent plastic film having an embossed surface, and a film having a light diffusing material having a different refractive index from that of the film base material embedded in or near the surface of the film. To be

Examples of the cover film for a display include a transparent plastic film having a hard coat layer such as silicone or acrylic formed on the surface thereof.

The film used in the present invention is not limited to the above polarizing film, retardation film, light condensing film and light diffusing film, and may be a conductive film, Fresnel lens film, lenticular film or the like.

When the antireflection member of the present invention is used as a polarizing film, a retardation film or a light condensing film of a liquid crystal display device, the light transmittance can be improved and the brightness can be improved. The power consumption of the light source of the liquid crystal display device can be reduced. Further, when the film is attached to the surface of various display devices, reflection due to external light can be reduced and the display can be easily viewed. However, it goes without saying that these application examples do not limit the present invention.

[0022]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but it goes without saying that these examples do not limit the present invention.

Preparation Example 1 of coating liquid FOMBLIN Z DISOC (manufactured by Ausimont)
0.4 g, FOMBLIN Z TETRAOL (manufactured by Ausimont), 1,4-bis (trifluoromethyl) benzene 20 g, and Fluorinert FC-75
It was dissolved in 60 g (Sumitomo 3M). 0.1 to this solution
% A solution A was prepared by adding 0.5 g of a trifluorotoluene solution of di-n-butyltin (VI) dilaurate.

Preparation Example 2 of coating liquid FOMBLIN Z DISOC (manufactured by Ausimont)
0.4 g, FOMBLIN Z DOL (manufactured by Ausimont), 20 g of 1,4-bis (trifluoromethyl) benzene, and Fluorinert FC-75 (Sumitomo 3
It was dissolved in 60 g. A solution B was prepared by adding 0.6 g of a 0.1% solution of di-n-butyltin dilaurate (VI) in trifluorotoluene to this solution.

Example 1 Solution A was applied by a dip coating method to a polarizing film having a hard coat layer formed of an acrylic resin, and then 10
A thin film of the reaction product was formed on the surface of the film by heating at 0 ° C. for 1 hour. The refractive index of this thin film was 1.349. Further, the reflectance of this film at 550 nm and the light transmittance in the visible light region were measured. The results are shown in Table 1.

Example 2 Solution A was applied by a dip coating method to a polarizing film having its surface subjected to a non-glare treatment, and then heated at 100 ° C. for 1 hour to form a thin film of a reaction product on the surface of the film. The reflectance of this film at 550 nm and the light transmittance in the visible light region were measured. The results are shown in Table 1.

Example 3 Solution A was applied to a transparent film made of polyethylene terephthalate by a dip coating method, and then heated at 100 ° C. for 1 hour to form a thin film of a reaction product on the surface of the film. The reflectance of this film at 550 nm and the light transmittance in the visible light region were measured. The results are shown in Table 1.

Example 4 Solution B was applied to a polarizing film having a hard coat layer formed of an acrylic resin by a dip coating method, and then 10
A thin film of the reaction product was formed on the surface of the film by heating at 0 ° C. for 1 hour. The refractive index of this thin film was 1.349. Further, the reflectance of this film at 550 nm and the light transmittance in the visible light region were measured. The results are shown in Table 1.

[0029]

[Table 1] Table 1 Examples Reflectance (%) Visible light transmittance (%) 1 Before coating 4.3 41.5 After coating 1.1 43.5 2 Before coating 4.2 43.5 After coating 1. 1 45.5 3 Before coating 6.5 88.7 After coating 1.7 92.3 4 Before coating 4.3 41.7 After coating 1.1 43.4

From this table, the film coated with the antireflection coating by the method of the present invention has a low reflectance and a high light transmittance in the visible light region as compared with the untreated film, which is excellent. It can be seen that an excellent antireflection film was obtained.

[0031]

EFFECTS OF THE INVENTION The present invention proposes an antireflection film obtained by carrying out a reaction on a substrate without requiring a complicated operation for synthesis. Further, by using this antireflection film, the antireflection property can be imparted to the surface of the optical article by a simple method.

Claims (6)

[Claims] 1. A film of a fluorine compound formed by the reaction of a fluorine compound having at least one isocyanate group in one molecule with a compound having a functional group capable of reacting with an isocyanate group is present on at least one surface of a substrate. An antireflection body characterized by being. 2. The antireflection body according to claim 1, wherein the substrate is a film. 3. The antireflection body according to claim 2, wherein the film is an optical film. 4. The antireflection body according to claim 3, wherein the optical film is a polarizing film, a retardation film, a light condensing film or a light diffusing film. 5. The antireflection body according to claim 2, wherein the film is a display cover film. 6. A fluorine compound film is formed by reacting a fluorine compound having at least one isocyanate group in one molecule with a compound having a functional group capable of reacting with an isocyanate group on at least one surface of a substrate. A method of manufacturing an antireflection body, comprising: