JPS61106211A - Mold for manufacturing hydrophilic plastic lens and manufacture of the same by employing the mold - Google Patents

Abstract

PURPOSE:To reduce the frequency of replacement of the mold and obtain the lens having prominent optical surface stably and easily by a method wherein the hydrophilic plastic lens is manufactured by casting and polymerizing method by employing the mold made of fluorine series glass. CONSTITUTION:The mixture of monomer, consisting of 60 parts by weight of 2,3-dihydroxypropylmethacrylate, 30 parts by weight of tetraethylene glycol dimethacrylate, 10 parts by weight of ethylene glycol dimethacrylate and 0.3 parts by weight of azobisisobutyronitrile, is poured into a frame consisting of the template of fluorine series glass FCD-1, which is finished to mirror surface by grinding work, and a gasket of polyvinyl chloride. The lens is separated from the frame after heating the template from 45 deg.C to 80 deg.C under spending 24hr. Lens thus obtained has no retention of the material of the mold, no fin of molded product of lens and no surface defect due to bubbles or the like and is provided with the prominent optical surface. No abnormality exists in the lens and the mold is stable for forming multitude of lenses continuously.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a mold for manufacturing a hydrophilic plastic lens and a method for manufacturing a hydrophilic plastic lens using this mold. The present invention relates to a mold used when molding a hydrophilic plastic by cast polymerization of a mixture containing the same, and a method for manufacturing a hydrophilic plastic lens using this mold.

[Conventional technology]

When producing plastic lenses by cast polymerization, a combination mold consisting of a glass mold made of silicate or borate glass and a resin gasket is usually used. Although such a template is suitable for cast polymerization of hydrophobic plastic lenses such as polydiethylene glycol bisallyl carbonate and polymethyl methacrylate, it cannot be used for cast polymerization of plastic lenses having hydrophilic groups. The reason for this is that a plastic lens having a hydrophilic group has high adhesion to ordinary glass, so that it becomes extremely difficult to take out the plastic lens from the glass mold at the end of polymerization. Therefore, when casting-polymerizing a plastic lens containing such a hydrophilic group, an example has been proposed in which a mold made of a specific material is used.

That is, Japanese Patent Publication No. 55-2605 and Japanese Patent Publication No. 57-1
No. 89114 discloses a mold made of polyethylene, polypropylene, etc., published in Japanese Patent Publication No. 57-46734.
The publication describes the use of polyallyl diglycol carbonate as a template.

[A shortcut to solving problems]

The present invention provides good releasability from the hydrophilic plastic lens when producing a plastic lens having a hydrophilic group by a cast polymerization method, and can provide the plastic lens with an excellent optical surface. Production of a hydrophilic plastic that can stably produce hydrophilic plastic lenses using a mold with excellent durability, surface precision, and rigidity, and a π-forming process similar to the cast polymerization method for ordinary plastic lenses using this mold. The purpose is to provide a method.

The present invention is characterized by the fact that the mold itself made of fluorine-based glass is durable and
Focusing on its high surface precision and rigidity, the molecules of fluorine-based glass are less likely to form a primary bond due to a chemical reaction with the raw material monomer of the hydrophilic plastic, and the adhesion between the two is achieved through attraction due to intermolecular force. This was achieved by focusing on the characteristics such as low adhesive force based on electrostatic attraction between the fluorine glass mold and the raw material monomer of the hydrophilic plastic, and low wettability between the two. The casting mold for cast polymerization of a mixture containing a monomer having a hydrophilic group is made of fluorine glass. It is characterized by manufacturing plastic lenses.

In the present invention, as raw materials for plastic lenses having hydrophilic groups, Japanese Patent Publication No. 52-47427,
Hydroxy lower alkyl acrylate, hydroxy lower alkyl methacrylate, hydroxy lower alkoxy lower alkyl acrylate, hydroxy lower alkoxy lower alkyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate described in JP 55-6062, JP 57-46764, etc. , polyethylene glycol cyacrylate, polyethylene glycol dimethacrylate, phosphoric acid acrylate, phosphoric acid methacrylate, acrylic acid,
Representative examples include methacrylic acid, acrylamide, methacrylamide, etc., but are not limited thereto. Examples of hydroxy lower alkyl acrylate include 2-hydroxyethyl acrylate, 2-
Typical examples include hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, etc., and examples of hydroxy lower alkyl methacrylate include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2,3-dihydroxypropyl acrylate. Representative examples include methacrylate and the like.

In the present invention, cast polymerization includes not only the commonly used method using a polymerization initiator, but also polymerization using ultraviolet rays or radiation irradiation.

The mold used in such cast polymerization is made of fluorine glass. Examples of the fluorine-based glass include fluoride phosphate glass, fluoride silicate glass, and fluoride borosilicate glass.

The content of fluorine in these fluorine glasses is preferably 1% by weight or more. Fluorine content in glass is 1% by weight
If it is less than this, primary bonding due to chemical reaction between the raw material monomer of the hydrophilic plastic lens and the molecules in the fluorine-based glass and attraction between the two due to intermolecular attraction tend to occur, and wettability tends to decrease. Fluorides added to glass include Be F2, cap2% MgF2
．． 8 r F2, BaF2, AA! F3, (eF'
2. Examples include LaF3, PI)72, ThF'2, and the like.

Preferred composition examples of the fluorine-based glass used as the mold of the present invention are shown below.

(a) Composition example of fluoride phosphate glass AIF132
0~35 1 YF3Q~5 BaF2+SrF2+0aF2+MgF222~55
'NaF + KIF + Llp O
~25 p(b) Fluoride silicate glass composition 5i02 30-50% by weight 2T
ill'45 5~52 lTiO
20-62 〃 200-32 1 Ag2O30,1-6 Commercial products of fluorine-based glass used as the mold of the present invention include PC-1, FC-3, FC-5, P manufactured by Hoya Glass ■.
C-1, FOD-'l, FOD-3, FCD-5, FC
! Examples include D-10.

Cast polymerization molds are subjected to extremely large forces during shrinkage and mold release during polymerization, so the molds must have durability, surface precision, and rigidity, and the glass mold surface must have minimal scratches. Even if there is such a problem, it will cause serious defects in the resulting lens, and furthermore, these scratches will grow further due to the pressure, pressing force, etc. applied during mold release, and the lens will need to be polished, cleaned, and dried.

Although fluorine-containing glasses can satisfy these requirements, in particular, 72%
P205-1/2 B2O3-Me(F) [here M9
(F) refers to the above-mentioned fluoride) type optical glass is preferably used.

The above fluorocarbon glass material is sanded and polished,
The mold of the present invention is obtained by surface processing the mold into a shape having a desired constant curvature. Note that this mold is preferably air-cooled and strengthened.

〔Effect of the invention〕

The mold of the present invention has good mold releasability for hydrophilic plastics, is rich in durability, surface precision, and rigidity, and is also excellent in workability. According to the method for producing a hydrophilic plastic lens, it is possible to stably and easily produce a hydrophilic plastic lens having an excellent optical surface while reducing the frequency of mold replacement.

[Embodiments of the invention]

Example 1 60 parts of 2.6-dihydroxypropyl methacrylate,
A fluorine-based glass FCD made by polishing a monomer mixture consisting of 30 parts of tetraethylene glycol methacrylate, 10 parts of ethylene glycol dimethacrylate, and 0.3 parts of azobisin butyronitrile to a mirror finish.
1 (manufactured by Hoya Glass) and a polyvinyl chloride gasket, the mold was heated from 45°C to 80°C over 24 hours, and then the mold and the lens were separated. 0FCD-1 The mold and lens were separated by blowing air between the two using an air gun, applying cooling and pressure to the contact surface between the two.
The aD-1 mold was easily peeled off from the lens. Next, when we performed an external and internal inspection of the surface of the lens using a condensing irradiator, we found that mold material remained on the lens due to partial contact between the mold and the lens, and that mold material remained on the lens during lens molding. It was confirmed that the lens had no surface defects such as flakes or bubbles and had an excellent optical surface, and there were no abnormalities inside the lens, making it suitable as a mold for producing hydrophilic plastics. The mold was also stable for continuous and large amounts of lens molding. It consists of a part mold made of fluorine-based glass YEN-5 (Hoya Glass Department) made of a monomer mixture consisting of 0.5 parts of (butyl peroxyzocarbonate) polished to a mirror finish, and a polyethylene gasket. Pour into the mold and heat at 40℃ for 20 hours, then at 60℃ for 2 hours.
After holding at 80° C. for 2 hours, the mold and the lens were separated. The separation between the IPCD-1 mold and the lens and the surface and interior of the obtained lens were as excellent as in Example 1.

Comparative Example 1 60 parts of 2.3-dihydroxiderovir methacrylate,
Borosilicate glass Boo is made by polishing a monomer mixture consisting of 30 parts of tetraethylene glycol dimethacrylate, 10 parts of ethylene glycol dimethacrylate, and 0.3 parts of azobisisobutyronitrile to a mirror finish.
-7 (Hoya Glass Membrane) Pour the mold into a mold made of a mold and a polyvinyl chloride gasket.
The temperature was increased from .degree. C. to 80.degree. C. over 24 hours. Thereafter, the gasket was removed and an attempt was made to separate the B-day A-7 mold and the lens in the same manner as in Example 1, but this was not possible. In addition, I drove a V-shaped wedge into the contact surface between the SSO-7 mold and the lens and tried to separate them again, but the two did not separate.When I applied pressure to the wedge and drove it in, the BSO-7 mold broke. At the same time, scratches appeared on the lens surface.

Claims (6)

[Claims] (1) A mold for producing a hydrophilic plastic lens, characterized in that the mold is made of fluorine-based glass, in a mold for cast polymerization of a mixture containing a monomer having a hydrophilic group. (2) The mold for producing a hydrophilic plastic lens according to claim 1, wherein the fluorine-based glass is glass having a fluorine content of 1% by weight or more. (3) The mold for producing a hydrophilic plastic lens according to claim 1, wherein the fluorine-based glass is a tempered glass. (4) A method for manufacturing a hydrophilic plastic lens by injecting a mixture containing a monomer having a hydrophilic group into a mold and polymerizing the hydrophilic plastic, wherein the mold is made of fluorine-based glass. How to manufacture lenses. (5) The method for producing a hydrophilic plastic lens according to claim 4, wherein the fluorine-based glass is glass having a fluorine content of 1% by weight or more. (6) The method for manufacturing a hydrophilic plastic lens according to claim 4, wherein the fluorine-based glass is tempered glass.