JPH09258009A - Polarizing lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing lens having a thin central thickness. SOLUTION: A polarizing film 3 is laminated on the surface of a lens 4. A PVA film which is impregnated with an iodine compd. (or dichromatic dye) as a polarizer, is uniaxially stretched and is formed by laminating with protective films (for example, polycarbonate and polyester) on both surfaces thereof is used for the polarizing film 3. The film which consists of polyester, polycarbonate, etc., as a base and is blended with the dichromatic dye is uniaxially stretched, by which the obtd. film is equally well. The lamination of the polarizing film 3 is executed by sticking with an adhesive, etc. A hard coating and antireflection coating are formed at need on the outer side of the polarizing film 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing lens in which the lens center thickness is suppressed to be almost equal to that of an ordinary lens.

[0002]

2. Description of the Related Art A polarizing lens made of plastic is composed of a polarizing film. Conventionally, as this polarizing film, a PVA (polyvinyl alcohol) impregnated with an iodine compound or a dichroic dye and uniaxially stretched has been used. Since this polarizing film has drawbacks such as brittleness and poor moisture resistance, it is necessary to protect the surface when it is used for eyeglasses. Therefore, as shown in FIG. 2, it has been indispensable for a conventional plastic polarizing lens to employ a structure (sandwich structure) in which a polarizing film is sandwiched between lenses. There are the following two types of manufacturing methods for the lens having such a structure (manufacturing method A and manufacturing method B).

Manufacturing Method A A thin lens for the R1 surface and a thick lens for the R2 surface are separately molded, and a polarizing film is sandwiched between them and bonded.

Manufacturing method B When a plastic lens is molded, a polarizing film is placed between an upper mold half and a lower mold half, and a monomer is poured. Then, it is polymerized as it is. This manufacturing method is described, for example, in Japanese Patent Publication No. 55-13009 and Japanese Patent Laid-Open No. 59-1871.
No. 9 is disclosed.

The production method A is very disadvantageous in terms of cost because it requires a step of adhering the lens and the film in addition to a step of forming two lenses. On the other hand, the manufacturing method B is
Since only one molding step is required, it is more cost effective than the manufacturing method A.

[0006]

In any of the above-mentioned manufacturing methods A and B, the conventional polarizing lens has a structure in which a polarizing film is sandwiched by plastics.
The center thickness was 1 mm or more thicker than that of a normal spectacle lens. As a result, the edge thickness and weight tend to increase significantly. In particular, in a medium-high refractive index lens, the effect of increasing the refractive index is negated, which impairs the marketability.

An object of the present invention is to provide a polarizing lens whose center thickness is suppressed to be equal to that of a normal lens.

[0008]

The present invention has been made in order to achieve the above object, and in a first aspect thereof, a plastic lens and a polarizing film laminated on the surface of the lens. There is provided a polarizing lens having:

The polarizing film is preferably one containing polyester or polycarbonate.

It is preferable to further have a hard coat provided on the polarizing film.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described with reference to FIG.

The polarizing lens of the present invention has a structure in which a polarizing film, which will be described later, is directly laminated and fixed on the lens surface as shown in FIG. This minimizes the increase in lens center thickness.

Two types (types A and B) will be given as examples of the polarizing film usable in the present invention.

Type A) Iodine compound (or dichroic dye) as a polarizer
Is a polarizing film obtained by uniaxially stretching a PVA film impregnated with and further laminating protective films on both surfaces thereof.

Type B) A base material made of polyester, polycarbonate or the like and a dichroic dye blended therewith is molded into a film,
It is a polarizing film obtained by subsequent uniaxial stretching.

In the present invention, the polarizing film has a heat resistance of 90 ° C. or higher (more preferably 100 ° C. or higher) because it is heated in the process of curing the adhesive, the process of polymerizing the monomer, and the process of forming the hard coat. Is desirable. Therefore, as the polarizer, a dichroic dye having a higher heat resistance than the iodine compound and having abundant color tone and rich fashionability is more preferable.

As the resin material for the protective film and the base, polyester (for example, polyethylene terephthalate) and polycarbonate, which have high heat resistance and excellent transparency, are preferable.

The thickness of the polarizing film is about 10 to 500 μm. If the thickness is further reduced, the degree of polarization and mechanical strength will be insufficient. On the other hand, if the thickness is further increased, the object of the present invention of reducing the thickness of the lens cannot be sufficiently achieved. From the viewpoint of making the lens thinner, the polarizing film of type B (film based on polyester etc.) can be thinner than the polarizing film of type A (with protective film). More preferable.

The polarizing film usable in the present invention is not limited to the above-mentioned two types (types A and B).
Other polarizing films may be used as long as they have sufficient strength. Further, although the life is shortened, it is possible in principle to use the conventional polarizing film as it is.

Examples of the material of the plastic lens on which the polarizing film of the present invention can be laminated include the following thermoplastic resins and thermosetting resins.

Examples of the thermoplastic resin include polystyrene, polymethylmethacrylate, cellulose acetate and the like.

As the thermosetting resin, an allyl resin (for example, allyl diglycol carbonate and its copolymer, diallyl phthalate and its copolymer), fumaric acid resin (for example, benzyl fumarate copolymer),
Polyurethane resin (for example, addition polymer of polyvalent isocyanate and polyvalent thiol), acrylic resin (for example,
Polymers of polyvalent thioacrylic acid or polyvalent thiomethacrylic acid ester) and the like.

As a method for laminating a polarizing film on a plastic lens, the following two methods can be considered.

Manufacturing Method 1) Manufacturing method 1 is a method of bonding the lens and the polarizing film with an adhesive.

First, the polarizing film is bent according to the curvature of the lens surface to which the polarizing film is attached.
This bending process can be performed by a method such as vacuum forming, pressure forming, and press forming.

Next, the bent polarizing film is attached to the lens surface with an adhesive (or an adhesive). In this case, the adhesive or the like is cured by applying heat or light as needed. At the time of curing, it is preferable to place weight on the stone or to apply pressure by an autoclave or the like to cure. By doing so, the thickness of the adhesive layer can be made uniform over the entire adhesive surface. In addition, it is possible to prevent bubbles from entering between the polarizing film and the lens, and to discharge the trapped bubbles.

As the adhesive (or pressure-sensitive adhesive), epoxy resin, urethane resin, unsaturated polyester resin, cyanoacrylate resin, spirane resin, polyacrylic acid ester resin, silicone resin, etc. should be used. You can

In some cases, the lens itself to which the polarizing film is attached may be used as a mold for bending the polarizing film (manufacturing method 1 '). In this case, if the film and the lens are processed after being applied with an adhesive or the like, the bending and the bonding can be simultaneously performed at the same time.

Manufacturing Method 2) In Manufacturing Method 2, a polarizing film is attached to a lens-molding die with an adhesive or the like, and a monomer is directly added to the die and polymerized to form a lens and attaching a polarizing film ( (Fixed) is a method to carry out collectively. The polarizing film is bent beforehand according to the curvature of the inner surface of the lens mold.

When the polarizing film is strong enough to withstand polymerization, the polarizing film itself can be used as one mold to form a plastic lens by a cast polymerization method. That is, a mold is created with the polarizing film, the other mold and the gasket (or tape). Then, inject the monomer into this mold,
Polymerize while applying heat and light as needed. After completion of the polymerization, the gasket (or tape) is removed and the polarizing lens is taken out from the mold. In order to increase the adhesion strength with the monomer (or adhesive), the polarizing film may be subjected to a pretreatment (eg, primer treatment, corona discharge treatment, plasma treatment) as necessary.

Since the polarizing film is uniaxially stretched in most cases, it has a property of being easily torn in one direction. Therefore, when the surface of the polarizing film is used as in the present invention, it is more preferable to form a hard coat for protecting the polarizing film.

Examples of the hard coating agent include fine particles of inorganic substances (for example, silicon oxide, tungsten oxide, antimony oxide, tin oxide, tantalum oxide, aluminum oxide,
Examples thereof include a silicone-based hard coating agent containing iron oxide) alone or in a composite state, a polyfunctional acrylate-based hard coating agent, and the like. To improve the adhesion of the hard coat,
If necessary, the polarizing film may be subjected to pretreatment (for example, application of a primer, corona discharge treatment, plasma treatment).

The hard coat on the polarizing lens may be formed after the lens is completed, or may be formed in advance on the polarizing film before being attached to the lens.

It is also possible to further form an antireflection coat or a mirror coat on the hard coat.

A primer layer may be provided between the hard coat and the polarizing film (or between the substrate and the polarizing film) to absorb impact and improve adhesion.
As the material for the primer layer, urethane-based or polyvinyl butyral-based materials can be used. In addition, by adding inorganic oxide particles that can be added to the above hard coat to the primer layer, hardness, refractive index, adhesion, etc. can be controlled.

It is also possible to form an antireflection film of an inorganic substance (for example, aluminum oxide, silicon oxide, zinc oxide, titanium oxide) on the hard coat. A vacuum evaporation method (or a sputtering method, a CVD method) can be used for forming the antireflection film.

On the antireflection film, a water stain prevention layer for preventing water stain can be further formed. This anti-water stain layer can be formed by using a dipping method (or a vacuum deposition method, a sputtering method, a CVD method) using an organic silicon compound containing fluorine as a material.

[0038]

EXAMPLES The center thickness of the lens in each of the following examples was measured using a dimensional measuring instrument (trade name "Digimicro ME-501", manufactured by Nikon Corporation).

[Example 1] Polarizing film: type B, manufacturing method 1 For a polarizing film of type B prepared in advance (material: polyethylene terephthalate, thickness: 60 μm), a curvature type (material: aluminum, curvature) : 105R, external shape: 7
Bending was performed by the drape forming method using a vacuum forming machine using 0φ). At this time, the temperature of the polarizing film was 190 ° C and the mold temperature was 100 ° C. The curvature of the polarizing film after molding was 88R.

Separately prepared spectacle lens (material: allyl diglycol carbonate, front surface side curvature: 105R, rear surface side curvature: 88R, center thickness: 1.8 mm, diameter: 70
A two-component epoxy adhesive was dropped on the surface of φ) and this polarizing film was attached. A glass lens (curvature 88R, mass: 100 g) was placed on this as a weight and heated in an oven (80 ° C., 1 hour) to cure the adhesive.

Thereafter, a silicone hard coat containing a silicon dioxide sol was coated on the polarizing film by a dipping method. Further, an antireflection coat made of an inorganic oxide was coated thereon.

The center thickness of the polarizing lens obtained as described above was 1.9 mm, which was equivalent to that of a normal lens of the same class.

[Example 2] Polarizing film: type B, manufacturing method 1 A type B polarizing film prepared in advance (material: polyethylene terephthalate, thickness: 100 microns) was drape-molded using a vacuum molding machine. Bending was performed by the method. A semi-finished aspherical lens for spectacles (material: plastic, surface vertex curvature: 300R, outer diameter: 80φ) was used as a mold for this bending process. The temperature of the polarizing film during this bending process is 19
The mold temperature was 0 ° C and the mold temperature was 70 ° C. The vertex curvature of the polarizing film after molding was 300R.

Separately prepared sulfur-containing urethane lens (front surface side curvature: 300R, back surface side curvature: 125R, center thickness:
A two-component epoxy adhesive was uniformly applied to the surface of 1.1 mm, diameter: 80φ) with a spinner, and then the polarizing film was attached. A glass lens (vertex curvature: 300 R, mass: 100 g) was placed on this as a weight and heated in an oven (80 ° C., 1 hour) to cure the adhesive.

Thereafter, a silicone-based hard coat containing tungsten oxide sol is further formed on the uneven hardness film.
An antireflection coat consisting of an inorganic oxide was formed.

The center thickness of the polarizing lens obtained as described above was 1.2 mm, which was equivalent to that of a normal lens of the same class.

[Example 3] Polarizing film: type A, production method 2 A polycarbonate film (thickness: 100) on both sides of a PVA film (thickness: 40 microns) impregnated with a dichroic dye and uniaxially stretched. Micron)
A type A polarizing film was prepared.

Then, this type A polarizing film was bent by a straight molding method using a pressure molding machine. An aspherical glass lens (apex curvature: 300R, shape diameter: 80φ) was used as a mold in this bending process. The temperature of the polarizing film during this bending process is 16
The mold temperature was 0 ° C and the mold temperature was 100 ° C. The vertex curvature of the polarizing film after molding was 300R.

This polarizing film was used as a mold on the front side, a glass mold (curvature: 125R) was used as a mold for the back side, and together with a gasket (material: polyethylene vinyl acetate copolymer), a mold for casting polymerization ( A center thickness: 1.3 mm, a diameter: 80φ) was created. Chlorostyrene and a monomer for 2,2-bis (3,5-dibromo-4-methacryloyloxyethoxyphenyl) propane copolymer were injected into this, and the temperature was gradually raised in an oven (35 ° C. → 160).
C., required time: 16 hours) to polymerize by heating.

After curing, the gasket was removed and the glass mold was removed to obtain a polarized plastic lens.

After plasma treatment of both sides of this lens,
A silicone-based hard coat containing antimony oxide and an antireflection coat were formed.

The center thickness of the polarizing lens obtained as described above was 1.2 mm. This is the same thickness as a normal lens of the same class.

[Example 4] Polarizing film: type B, manufacturing method 1'A type B polarizing film (material: polyethylene terephthalate, thickness: 100 micron) prepared in advance was coated with a silicone adhesive. It was applied using a roll coater so that the thickness would be 20 microns.

After that, the polarizing film was bent and the lens was adhered simultaneously by the drape molding method using a vacuum shaping machine. That is, the aspherical lens for eyeglasses to which the polarizing film is attached (material: plastic, vertex curvature: 300R, back surface side curvature: 125R,
An outer shape: 80φ, a central thickness: 1.1 mm) was used as a mold for bending. As a matter of course, when setting the polarizing film in the vacuum forming device, the polarizing film was set so that the adhesive side was the lens side. The temperature of the polarizing film during this processing was 190 ° C, and the mold temperature was 70 ° C. The vertex curvature of the polarizing film after processing was 300R.

After the processing, a silicone hard coat and an antireflection coat were formed on the surface.

The center thickness of the polarizing lens obtained as described above was 1.2 mm. This is the same thickness as a normal lens of the same class.

[0057]

As described above, according to the present invention, it is possible to provide a polarized lens having a center thickness equivalent to that of an ordinary plastic lens.

When the adhesive method (manufacturing method 1) is used,
A polarizing lens is obtained by bonding a polarizing film to a finished product of an ordinary plastic lens. Therefore, there is no need to have a stock as a polarized lens, which is very economically advantageous. Furthermore, there is an advantage that various types of lenses and optical characteristics (color tone, degree of polarization) of the polarizing film can be developed.

Polycarbonate having excellent impact resistance,
Since the polyethylene terephthalate or the like is laminated, the polarizing lens of the present invention is excellent in impact resistance as compared with a normal lens.

[Brief description of drawings]

FIG. 1 is a schematic view showing a structure of a polarizing lens of the present invention.

FIG. 2 is a schematic diagram showing a structure of a conventional polarizing lens.

[Explanation of symbols]

 1 ... Polarizing film 2 ... Lens 3 ... Polarizing film 4 ... Lens

Claims (3)

[Claims] 1. A polarizing lens comprising a plastic lens and a polarizing film formed on the surface of the lens. 2. The polarizing lens according to claim 1, wherein the polarizing film contains polyester or polycarbonate. 3. The polarizing lens according to claim 1, wherein a hard coat is formed on the polarizing film.