JPS58194519A - Molding method of plastic lens for glasses - Google Patents

Abstract

PURPOSE:To obtain a lens excellent in transparency, by a method wherein liquid monomer or its prepolymer is injected between a resin gasket and 2 pieces of mold, a resin lens is molded by curing them, and the gasket is made of ionomer resin or resin mixture having ionomer resin as its main component. CONSTITUTION:When the liquid monomer or its prepolymer is injected between a resin gasket 1 and two pieces of mold 2, 3, and the plastic lens is molded by curing. The resin gasket 1 is made to be composed of ionomer resin or resin mixture having ionomer resin as its main component. The plastic lens for glasses excellent in transparency without white opaqueness can be manufactured in good workability (the dismantlement of gasket).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of molding a plastic lens for eyeglasses by cast polymerization, and more particularly, to a resin composition of a gasket used during cast polymerization.

Plastic lenses are mainly used as eyeglass lenses because they are lightweight and have excellent impact resistance and stainability. This plastic lens is usually made by injecting a liquid monomer such as diethylene glycol pisallyl carbonate between glass molds and polymerizing it in a heating furnace.
After curing, the molding P is removed and manufactured. A plastic family gasket is usually used to maintain this glass molding Pt at proper spacing and to prevent leakage of liquid monomer. This gasket requires appropriate flexibility for assembling and removing the molding r, and also requires good thermal stability so that it can be maintained at high temperatures for a long period of time. Conventionally, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and soft vinyl chloride resin have been used as slit materials that satisfy such required performance.

However, although these resins that have been conventionally used as gasket materials can be used with monomers such as diethylene glycol bisallyl carbonate, they do not have aromatic properties.
It cannot be used against a seven-pointer with J. This is because the monomer having the aromatic In has a large dissolving power for m-lipid, and since a part of the gasket is exposed during cast polymerization, the periphery of the obtained lens becomes cloudy.

An object of the present invention is to provide a molding method capable of obtaining a plastic lens for lens 11 that has good transparency without clouding even when a liquid monomer with high resin solubility is used.

Another object of the present invention is to provide a method for molding a plastic lens for spectacles, which is free from leakage of monomer during polymerization and has excellent workability (gasket removal).

Therefore, the present inventors conducted intensive research to develop a gasket material that does not have such drawbacks, and as a result, they discovered that an ionomer resin or a resin mixture containing an ionomer resin as a main component exhibits excellent gasket performance. This invention has been achieved.

The gist of the present invention is that when a liquid monomer or its solvolymer is injected between a resin gasket and two molds and cured to form a plastic lens, the resin gasket is made of an ionomer resin or an ionomer resin as a main component. A method of molding a plastic lens for eyeglasses, characterized in that the lens is made of a resin mixture of

As described above, in the present invention, an ionomer resin or a resin mixture containing an ionomer resin as a main component is used as the gasket material.

The ionomer resin used in the present invention refers to a polyolefin resin crosslinked by metal ions.

As a specific example, N is added to ethylene-methacrylic acid copolymer.
a, K, Mg, , Zn, and other metals treated with Surlyn (manufactured by DuPont), Coralen (manufactured by Asahi Dow),
Examples include Himiran (manufactured by Mikata Polychemical Co., Ltd.).

The resin mixture containing an ionomer resin as a main component used in the present invention includes a mixture of an ionomer resin and an ethylene-vinyl acetate copolymer, a mixture of an ionomer resin and an ethylene-ethyl acrylate copolymer, and a mixture of an ionomer resin and an ethylene-vinyl acetate copolymer. Examples include mixtures of soft vinyl chloride resins, mixtures of ionomer resins and low molecular weight polyethylene, mixtures of ionomer resins and chlorinated polyethylene, and mixtures of ionomer resins and chlorotrifluoroethylene low polymers. The melt index of the ionomer resin or the resin mixture mainly composed of the ionomer resin used in the present invention is 5 to 30#/10m
A range of 1n is preferred.

If it is less than 5 g/10 min, the resin will become hard, resulting in poor workability and sealing properties, and if it exceeds 30 g/10 m1n, heat resistance and monomer resistance will deteriorate, which is particularly preferred. Furthermore, it is of course possible to add antioxidants, plasticizers, mold release agents, ultraviolet inhibitors, stabilizers, antistatic agents, etc., which are usually added to plus snacks, as needed.

The method for forming the gasket used in the present invention includes compression molding, transfer molding, injection molding, etc., but injection molding is preferable from the viewpoint of shape accuracy and productivity of the gasket.

The shape of the gasket used may be any commonly used shape, and a typical one is shown in FIG. To use this, as shown in Figure 2, liquid monomer or its prepolymer is injected between the two moldings 2 and 3 through the gasket 1, and the molding is held by the spring 4. Then, polymerize and harden. However, although the socket is shown in the figure, it is an example, and the present invention is not limited thereto.

Further, as the material for the molding r used in the present invention, glass, metal, ceramics, plastics, etc. can be used, but glass is particularly preferable in order to obtain an excellent optical surface.

As the liquid monomer or its prepolymer used in the present invention, various types of materials that can be polymerized and cured to form a plastic lens are used, but the liquid monomer or its prepolymer used can be radically polymerized to have an aromatic mt- The effects of the present invention are particularly noticeable when the monomer contains a specific monomer. These aromatic mt-containing radically polymerizable monomers include styrene-11 conductors such as styrene, chlorstyrene, α-methylstyrene, dichlorostyrene, and bromustyrene, phenyl methacrylate, chlorphenyl methacrylate, dichlorophenyl methacrylate, and trichlorostyrene. Phenyl methacrylate 1 de7 phenyl methacrylate, phenyl methacrylate conductors such as methoxyphenyl methacrylate, benzyl methacrylate,
Chlorobenzyl methacrylate, bromobenzyl methacrylate, trichlorobenzyl methacrylate, tribromobenzyl methacrylate, methoxybenzyl methacrylate, benzyl methacrylate derivatives, 1-vinylnaphthalene, 2-vinylnaphthalene, α-naphthyl methacrylate, β-naphthyl methacrylate, 2,6-
Naphthalene derivatives such as allyl nisnal dicarmenate, allyl cinnamate, allyl 0-chlorocinnamate,
Allyl cinnamate conductors such as allyl 0-bromocinnamate and allyl 0-methoxycinnamate, bisphenol A-dimethacrylate, 2,3,5.6-titrachlorbisphene +1nol A-dimethacrylate, 2, 3,5
．． Bisphenol A-dimethacrylate rust conductor such as 6-thitraderomobisphenol A-dimethacrylate, 0
- Diallyl phthalates such as diallyl phthalate, diallyl isoheptalate, diallyl terephthalate, phenoxyethyl methacrylate, vinylpyridine, allylbenzene, 4-methoxyallylbenzene, 1-allyl-6
, 4-dimethoxybenzene and the like. These monomers may be used alone or in combination with other radically polymerizable monomers. In addition, the liquid monomer according to the present invention refers to one that is liquid at 60° C. alone or as a mixture.

A polymerization initiator is used to polymerize and cure the monomer, and examples of the polymerization initiator that can be used include di-secondary decyl peroxy dicarbonate, diisozolopyl peroxy dicarbonate, bis(4-tertiary)
Commonly used products such as (butyl cyclohexyl) peroxydicarbonate, di-6-medoxydecyl peroxyzocarbonate, di-2-ethylhexyl oxydicarbonate, benzoyl peroxide, lauroyl peroxide, azopis isodethyronitrile, etc. can use things.

The plastic lens produced by the method of the present invention is
It has good transparency, and dyeability does not cause color unevenness unlike when conventional gasket tubes are used. In addition, the gasket has sufficient flexibility and is excellent in workability (removal of the slit).

Next, the present invention will be explained in more detail with reference to Examples. All parts in the examples are based on weight. still,
The following examples are intended to better illustrate the invention, but the invention is not limited thereto.

Example 1 Ionomer resin (Dupont Rin AD-8102
, melt index 14 g/10 m1n) As a raw material, an annular slit was produced by injection molding.

A mixture of 70 parts of diallyl isophthalate, 60 parts of benzyl methacrylate, and 6 parts of diisoderovir peroxydicarmenate was injected into the mold consisting of an annular slot and two glass moldings P. ℃ to 8
The temperature was increased to 0° C. over 24 hours. After polymerization, the lens was removed from the mold and heat treated at 120° C. for 1 hour. The sket could be easily removed from the mold. The obtained lens had a transmittance of 91% and had good transparency, and no skets were observed to adhere to the periphery of the lens. Sumikarondel-F! -BL (Sumitomo Chemical tu)": When the obtained lens was immersed for 5 minutes in a dye solution at 80°C in which rg was dispersed in distilled water 11, it turned out to be a blue lens with no color unevenness (transmittance 7096, 585 nm). )
was gotten.

Example 2 A mixture with 30 parts of ionomer resin (DuPont Su-Rin φ1555 Unicar! 11! DPDJ9169, melt index 20 fl/10 min) was used as a raw material to produce an annular gasket by injection molding.

A mixed solution consisting of 70 parts of θ-chlorophenyl methacrylate, 50 parts of bisphenol A-dimethacrylate, and 0.2 parts of di-secondary decyl peroxydiconate was placed in a mold consisting of two glass molds P and the above gasket. The mixture was injected and heated from 60°C to 80°C over 24 hours.

After polymerization, the lens was taken out from the mold and heat treated at 100° C. for 1 hour. The gasket could be removed from the mold and the lens very easily.The resulting lens had a transmittance of 90%, had good transparency, and no gasket adhesion was observed around the lens. When the obtained lens was immersed for 10 minutes in a dyeing solution at 80°C prepared by dispersing 5 g of Sumikarondel-E-BL (manufactured by Sumitomo Chemical) and 20.9 g of benzyl alcohol in 11 g of distilled water, it turned out to be a uniform blue color. A lens (transmittance: 754,585 nm) was obtained.

Made by Ichi, NU○6460, Melt index 20y/1
An injection-molded foam-like gasket was produced using a material with a diameter of 0 mm ) as a raw material. The same monomer tube as in Example 1 was injected into a mold consisting of this gasket and two glass moldings, and polymerized and cured under the same conditions.

The obtained lens had a cloudy periphery and was translucent. In addition, when the lens was dyed in the same manner as in Example 1, the dyeing density was different at the periphery and center of the lens, resulting in a blue lens with uneven color.
169, melt index 20p/10 min
) As a tHA material, an s-shaped gasket was produced by injection molding. The same monomer as in Example 1 was injected into a mold consisting of this gasket and two glass moldings P, and polymerized and cured under the same conditions. The obtained lens had a cloudy periphery and was translucent. Further, when the lens was dyed in the same manner as in Example 1, the degree of dyeing was different between the periphery and the center of the lens, resulting in a blue lens with uneven color.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a gasket used in the method of molding plastic lenses for eyeglasses of the present invention, and FIG. 2 is a sectional view of an apparatus suitable for carrying out the method of molding plastic lenses for eyeglasses of the present invention. be. 1: Gasket, 2, 3: Molding r14: Molding retaining spring. Representatives: Asamura and 4 people

Claims (1)

[Claims] (Li) When a liquid monomer or its prepolymer is injected between a resin gasket and two moldings and cured to mold a plastic lens, the resin gasket is made of an ionomer resin or an ionomer resin. A method for molding a plastic lens for eyeglasses, characterized in that it is made of a resin mixture containing as a main component. (2) Claims in which the liquid monomer or its prepolymer contains a radically polymerizable monomer having an aromatic ring. The method for molding a plastic lens for eyeglasses according to claim 1. (3) Claim 1, wherein the ionomer resin is a polyolefin resin cross-linked by metal ions.
A method for molding a plastic lens for eyeglasses according to item 1 or 2. (4) A resin mixture whose main component is an ionomer resin,
Both the ionomer resin and ethylene-vinyl acetate are used in the method for molding plastic lenses for eyeglasses as described in Section 2. (5) A method for molding a plastic lens for eyeglasses according to item 1 or 2 of the resin mixture containing an ionomer resin as a main component.