JPH0535654B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a method for manufacturing plastic lenses.

"Prior Art and its Problems" Plastic lenses are lighter than inorganic glass lenses, have excellent impact resistance, and are dyeable, so they have been frequently used as lenses for glasses and cameras in recent years.

Conventionally, plastic lenses are usually manufactured by a casting method, but at that time, a glass or metal mold is coated with a mold release agent in advance.
After that, a monomer solution is injected, the monomer is polymerized and cured, and then the lens is released from the mold, and after cleaning, it is coated with a hard coat solution, and then cured by heat treatment.

When coating a plastic lens with a hard coat liquid, the wettability changes depending on the material, making it difficult to provide a hard coat film with excellent adhesion.

Furthermore, in order to improve the adhesion between the plastic lens and the hard coat film, the surface of the plastic lens is subjected to pretreatment such as activated gas treatment or chemical treatment. However, performing such processing is complicated.

Additionally, many plastic cleansers require a temperature of 120°C.
At higher temperatures, there are drawbacks such as yellowing or deformation, which limits the heat treatment conditions for the hard coat liquid.

OBJECTIVE OF THE INVENTION The present invention provides a method for producing a plastic lens with a hard coat that has excellent adhesion, in which a hard coat solution can be heat-treated at high temperatures without causing yellowing or deformation of the lens. The purpose is to

"Structure of the Invention" The method for manufacturing a plastic lens according to the present invention involves first treating the surfaces of two molds to be used with a mold release agent, then coating the hard coat liquid thereon and curing it, and then The method is characterized in that a monomer liquid is injected into the space formed by the mold and the annular gasket, and the monomer is polymerized.

In the present invention, the mold may be made of glass or metal, and the gasket may be made of any polymer such as polyvinyl chloride, polyvinyl acetate, polyethylene, or silicone rubber. I can do it.

To carry out the method of the invention, as described above,
First, the surfaces to be used of two glass or metal molds are treated with a mold release agent. There are no particular restrictions on the mold release agent that can be used in the method of the present invention, and examples include various silicone mold release agents, fluoroalkylalkoxysilanes, mineral oils, fatty acids and fatty acid esters, fatty acid phosphate esters, polyvinyl alcohol, and fluorocarbons. Examples include. Such a mold release agent is applied by a dip coating method, a spin coating method, or the like, and heat treatment is performed as necessary depending on the type of mold release agent used to harden it. Among the mold release agents, a fluorine-based silicone coating liquid (KP-801, manufactured by Shin-Etsu Chemical Co., Ltd.) is particularly preferred, and after applying this liquid by dip coating or spin coating, it is heated and cured.

Next, in the method of the present invention, a hard coat liquid is coated on the use surface of the mold that has been treated with a mold release agent as described above, and is cured to form a hard coat film.

The hard coat liquid is not particularly limited and may be any of various known hard coat liquids. For example, a liquid containing at least one of colloidal silica, colloidal antimony oxide, and colloidal titanium oxide as a refractive index adjusting component, and a silane coupling agent and a curing agent as a film forming component, dispersed in a solvent together with other additives. can be used.

Colloidal silica, colloidal antimony oxide, and colloidal titanium oxide are commercially available colloidal solutions in which ultrafine particles of silicic anhydride, antimony pentoxide, or titanium dioxide are dispersed in water or an alcohol-based dispersion medium. The amount of colloidal silica, colloidal antimony oxide and/or colloidal titanium oxide used is:
Although it is determined as appropriate depending on the refractive index to be adjusted, it is generally 5 to 70% by weight, preferably 20 to 50% by weight in the thin film to be formed.

As the silane coupling agent, any known silane coupling agent can be used, for example, one having the general formula R ¹ _n R ² _o SiX _4-(n+o) [wherein R ¹ is an alkyl group, an alkenyl group, a phenyl group] or represents a halogen, ^R2 represents an epoxy group, glycidoxy group, amino group, amide group, mercapto group, methacryloyloxy group, cyano group, or an organic group having a nuclear substituted aromatic ring, X represents a halogen,
A hydrolyzable group such as an alkoxy group, an alkoxyalkoxy group, an acyloxy group, m and n each represent a number of 0 to 2, and m+n≦3] and their hydrolysates or moieties Condensates can be used. Specific examples of these compounds include tetrafunctional silanes such as tetramethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)- γ-aminopropyltrimethoxysilane,
γ-ureidopropyltrimethoxysilane, γ-
Trifunctional silanes such as cyanopropyltrimethoxysilane, γ-morpholinopropyltrimethoxysilane, and N-phenylaminopropyltrimethoxysilane, and further, a portion of the trifunctional silane is substituted with an alkyl group, phenyl group, vinyl group, etc. Examples of difunctional silanes include dimethyldimethoxysilane, phenylmethyldimethoxysilane, vinylmethyldimethoxysilane, γ-chloropropylmethyldimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. Further, hydrolysates, partial condensates, etc. of these compounds can also be used. The film-forming components as described above are used in the formed thin film in an amount of 10 to 80% by weight, preferably 15 to 40% by weight.

As a curing agent, organic amines such as triethylamine and n-butylamine, amino acids such as glycine, metal acetylacetonates such as aluminum acetylacetonate, chromium acetylacetonate, titania acetylacetonate, and cobalt acetylacetonate, sodium acetate, and naphthene. Organic acid metal salts such as zinc acid, cobalt naphthenate, zinc octylate, tin octylate, Lewis acids such as tin chloride, aluminum chloride, ferric chloride, titanium chloride, zinc chloride, antimony chloride, etc. . Among these, aluminum acetylacetonate is particularly preferred.

Taking coating workability into consideration, it is preferable to dissolve the various components described above in an appropriate solvent to form a hard coat liquid. As a solvent, alcohol,
Ketones, cellosolves, formamides, water,
Various Freon solvents can be used.
Generally, it is preferable to use these solvents as a solution containing 1 to 45% by weight of solids, but the solvent is not limited to this range and can be appropriately selected depending on the situation.

In addition, a surfactant,
UV absorbers, antioxidants, thixotropic agents,
Pigments, dyes, antistatic agents, conductive particles, etc. can be added.

A hard coat liquid containing the various components described above is applied to the use surfaces of two molds by a known method and cured to form a hard coat film. Application can be performed by, for example, flow coating, dip coating, spin coating, roll coating, spray coating, or the like. Drying and curing are appropriately selected depending on the components used, but are preferably carried out by heating at 100 to 300°C for 40 minutes to 3 hours.

Further, in order to promote the crosslinking reaction and polymerization reaction of the reactive groups in the components used, curing can also be carried out by irradiation with infrared rays, ultraviolet rays, γ rays, or electron beams. The film thickness can be adjusted by using a solvent or a coating method, and is usually 2 to 10 μm, preferably 2 to 5 μm.

After forming a hard coat film on the use surfaces of the two molds in this way, a monomer liquid, which is the raw material for the plastic lens, is injected into the space formed by the two molds and the annular gasket.
Polymerization and curing are performed by a method known per se.

Plastics for lenses include, for example, acrylic resin, polycarbonate, diethylene glycol bisallyl carbonate polymer, di(meth)acrylate polymer of (halogenated) bisphenol A and its copolymer, urethane-modified (meth) of (halogenated) bisphenol A, etc. ) Acrylate polymers and copolymers thereof, polyurethane resins such as urethane resins made of diisocyanate and mercaptoalkyl ester of polyol, etc., but there are no particular limitations.

FIG. 1 shows the state of the mold release agent when producing a plastic lens by the method of the present invention. As shown in FIG. 1, a release agent layer 2 and a hard coat film 3 are provided on the use surfaces of two molds 1, and the mold 1 having the hard coat film and the gasket 4 A plastic lens 5 is cast into the space formed by the molding.

The plastic lens taken out from the mold after polymerization and curing of the monomers according to the method of the present invention is a product lens that already has a hard coat film, and can be dyed if necessary.

"Examples of the Invention" Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, in the examples, "parts" means "parts by weight" unless otherwise specified.

Example 1 (1) Preparation of hard coat liquid with refractive index n=1.60 20 parts of β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 60 parts of γ-glycidoxypropyltrimethoxysilane, and γ-glycid Xypropylmethyldiethoxysilane 20
1 part was hydrolyzed with 25 parts of 0.1N hydrochloric acid and stirred overnight. Next, 250 parts of methanol-dispersed antimony oxide sol (manufactured by Nissan Chemical Co., Ltd.), 0.1 part of Zonyl FSN (manufactured by DuPont) as a surfactant, and aluminum acetylacetonate as a hardening agent.
0.5 part and isopropyl alcohol as solvent
A hard coat solution was prepared by mixing 300 parts.
This liquid is hereinafter referred to as hard coat liquid X.

When this hard coat liquid was heated at 150°C for 1 hour, a film with a refractive index of 1.60 was produced.

(2) Manufacturing of plastic lenses Fluorine-based silicone coating liquid (manufactured by Shin-Etsu Chemical Co., Ltd., KP-801) is applied to the two surfaces of the glass mold mold.
was applied using the dip coating method and coated at 120°C.
Cured by heating for hours. Apply approximately 3.0 μm of hard coat liquid X to the glass mold having this mold release agent layer.
The film was coated to a thickness of 150°C and heat treated at 150°C for 1 hour.

In this way, m-xylylene diisocyanate and pentaerythritate tetrakis (3-mercaptopropionate) were mixed in a ratio of 1:1.3 in a space surrounded by two glass molds provided with a release agent layer and a hard coat film and an annular gasket. Contains dibutyltin dilaurate as an initiator in a weight ratio of
Inject the monomer mixture with the addition of 1000ppm,
Polymerization was performed at 30°C for 8 hours, at 40°C for 5 hours, and at 120°C for 4 hours to obtain a hard coated plastic lens. The refractive index of the obtained plastic lens molded product was 1.60.

Example 2 (1) Preparation of hard coat liquid with refractive index n=1.50 50 parts of γ-glycidoxypropyltrimethoxysilane and 50 parts of γ-glycidoxypropylmethyldiethoxysilane were added with 25 parts of 0.1N hydrochloric acid. Disassemble and stir overnight. Next, 250 parts of isopropyl alcohol-dispersed silica sol (manufactured by Catalyst Kasei Co., Ltd., OSCAL1432), 0.1 part of Zonyl FSN as a surfactant, 0.5 part of aluminum acetylacetonate as a hardening agent, and 300 parts of isopropyl alcohol as a solvent were mixed to harden the mixture. A coating solution was prepared. This liquid is hereinafter referred to as hard coat liquid Y.

This hard coat liquid produced a film with a refractive index of 1.50 when heated at 150°C for 1 hour.

(2) Manufacturing of plastic lenses Fluorine-based silicone coating liquid (manufactured by Shin-Etsu Chemical Co., Ltd., KP-801) is applied to the two surfaces of the glass mold mold.
was applied using the dip coating method and coated at 120°C.
Cured by heating for hours. Apply approximately 4.0 μm of hard coat liquid Y to the glass mold having this mold release agent layer.
The film was coated to a thickness of 150°C and heat treated at 150°C for 1 hour.

Diethylene glycol bisallyl carbonate monomer was injected into the space surrounded by the two hard-coated glass molds and the annular gasket as described above, and the mixture was heated at 40°C for 8 hours and then heated at 50°C.
Polymerization was performed for 2 hours at 70℃, 2 hours at 80℃, and 3 hours at 80℃ to produce a hard coated plastic lens. The refractive index of both the resin and hard coat film was 1.50.

"Effects of the Invention" According to the method of the present invention, since the hard coat film on which the lens is to be provided is attached and formed on the surface of the mold to be used, the heat treatment conditions during the formation of these films are not limited, and the conventional method Even if heat treatment is performed at a higher temperature than in the case of plastic lenses, the plastic lens will not be deformed or yellowed, and the heat treatment time can be shortened.

Furthermore, in the conventional method of applying a hard coat liquid to a plastic lens, the wetting characteristics vary depending on the material, but according to the method of the present invention, the wetting characteristics of the hard coat liquid are good. Furthermore, in the method of the present invention, a mold type 2 having a hard coat film is used.
Since the lens is molded by injecting the monomer liquid into the space formed by the lens film and the gasket, the adhesion between the hard coat film and the lens is improved compared to the conventional method of applying hard coat liquid to the lens molded body. Are better.

The product obtained by the method of the present invention is hard-coated, so it is easy to handle, and it is also resistant to heat, so it can be dyed.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a plastic lens manufactured by the method of the present invention before being released from the mold. Explanation of symbols 1...mold type, 2...mold release agent layer,
3...Hard coat film, 4...Gasket, 5...Plastic lens.

Claims (1)

[Claims] 1. First, the surfaces to be used of the two molds are treated with a mold release agent, and then a hard coat liquid is coated and cured, and then monomer is injected into the space formed by the molds and the annular gasket. A method for producing a plastic lens, characterized by injecting a liquid and polymerizing monomers.