JPH0158481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an anti-fog lens, and more particularly to a method for manufacturing an anti-fog lens made of porous glass and hydrophilic plastic.

Generally, when the surface of glass, metal, etc. falls below the dew point temperature, moisture in the air condenses on the surface, causing cloudiness. Measures to prevent this fogging include keeping the surface temperature above the dew point and reducing the contact angle. Alternatively, it is being considered to make it water-absorbing.

It is difficult to maintain the surface temperature of eyeglass lenses always above the dew point, so attempts are being made to reduce the contact angle and make them water absorbent.

For this reason, conventional methods have been used to coat the lens surface with a hydrophilic substance such as a surfactant, or to coat the lens surface with melamine resin containing a hydrophilic compound. The latter method also has the disadvantage that, although the adhesive strength is high, the coating film may peel off or the lens surface may sag when used for a long period of time. In order to increase the adhesion strength, a method of coating the lens surface with a hydrophilic polymer after making minute irregularities (Japanese Patent Application Laid-Open No. 1983-1999)
No. 28023, etc.) have also been devised, but they do not dramatically increase the adhesive strength and do not completely overcome the drawbacks of the prior art.

An object of the present invention is to provide a method for manufacturing an anti-fog lens having excellent anti-fog properties and durability.

As a result of intensive research aimed at improving the above-mentioned drawbacks, the present inventors impregnated a hydrophilic monomer into porous glass having continuous pores, which is produced by immersing phase-separated glass in an acid solution. The present invention was achieved based on the discovery that an anti-fog lens having excellent anti-fog properties and durability can be obtained by polymerizing the compound after the polymerization. Note that continuous pores refer to loopholes that are continuous from one surface to the same surface or another surface.

The gist of the present invention is to impregnate a hydrophilic monomer into a porous glass having continuous pores, which is produced by immersing phase-separated glass in an acid solution, and then polymerize the antifogging material. It's in the manufacturing method of the lens.

The hydrophilic monomer used in the present invention is selected from acrylic acid, monoacrylates, methacrylic acid, monomethacrylates, diacrylates, and dimethacrylates, and specific examples include polyethylene glycol Monoacrylate, acrylic acid, N,N'-dimethylaminoethyl acrylate, methacrylic acid, 2-hydroxyethyl methacrylate, glycidyl methacrylate, polyethylene glycol monomethacrylate, N,N'-dimethylaminoethyl methacrylate, polyethylene glycol diacrylate, polyethylene glycol Mention may be made of dimethacrylates and mixtures thereof.

Further, the porous glass having continuous pores used in the present invention has, for example, a predetermined proportion of Na ₂ O, B ₂ O ₃
A batch of SiO _{2 and SiO 2} is roasted, formed into a lens shape, heated to a predetermined temperature to create a split-phase glass, and then immersed in dilute sulfuric acid to form a glass that is easily soluble in acids. Na ₂ O, B ₂ O ₃
It is created by eluting the phase. The porous glass thus obtained has a pore size of 50~
Preferably it is 2000 Å. If the pore size is 49Å or less,
This is not preferable because it becomes difficult to impregnate the monomer and the durability of the antifogging performance becomes poor. A pore diameter of 2001 Å or more is not preferable because the surface precision of the lens deteriorates due to polymerization shrinkage during polymerization of the impregnated monomer, making it difficult to obtain an optical surface.

The hydrophilic monomer is impregnated into the porous glass by adding a predetermined amount of a polymerization initiator such as α,α′-azobisisobutyronitrile or bis(4-t-
It is carried out by immersing porous glass in a mixture obtained by adding butylcyclohexyl) peroxydicarbonate.

Polymerization of the hydrophilic monomer impregnated into the porous glass is carried out by means such as heating or ultraviolet irradiation. Preferably, the polymerization is carried out in an inert gas atmosphere. The inert gas herein refers to a gas that does not participate in the polymerization reaction of the hydrophilic monomer, and specific examples thereof include rare gases such as nitrogen and helium.

Simply making discontinuous minute holes in the glass or plastic surface makes it difficult to sufficiently impregnate the hydrophilic monomer, and the resulting anti-fog lens also has poor durability. In contrast, in the present invention, since porous glass having continuous pores is used, the hydrophilic monomer is sufficiently impregnated into the continuous pores, and the polymer obtained by polymerization is integrated with the porous glass. As a result, an anti-fog lens with excellent anti-fog properties and durability capable of withstanding long-term use was obtained.

Next, the details of the present invention will be explained using examples. Note that all "parts" in the examples are based on weight.

Example 1 A batch of 8.5 parts of Na _{2 O} , 23 parts of B ₂ O ₃ , and 68.5 parts of SiO ₂ was roasted, molded into a lens shape, and heated to 550°C to produce a phase-separated glass. immersed in sulfuric acid,
A porous glass having a specific surface area of 200 m ² /g, a porosity of 25% by volume, a dry apparent specific gravity of 1.5, and continuous pores of about 500 Å was produced. This porous glass
-100 parts of hydroxyethyl methacrylate, α,
It was immersed for 10 hours in a mixed solution consisting of 0.2 parts of α'-azobisisobutyronitrile and 3 parts of benzoin ethyl ether. At this time, the porous glass was completely transparent.

This porous glass was taken out from the mixed solution, prepolymerized by irradiating it with ultraviolet light for 1 minute using a 400 W ultraviolet lamp in a nitrogen atmosphere, and then heat-treated at a temperature of 80° C. for 10 hours.

The obtained lens was optically transparent and did not become cloudy even after being cooled to 0° C. and left at room temperature. Even after repeating this operation 5000 times, the antifogging effect did not deteriorate.

Example 2 A mixed solution consisting of 40 parts of 2-hydroxyethyl methacrylate, 40 parts of glycidyl methacrylate, 20 parts of tetraethylene glycol dimethacrylate, 0.3 parts of α,α'-azobisisobutyronitrile, and 5 parts of benzoin methyl ether was added to the liquid mixture. Porous glass prepared in the same manner as the porous glass used in 1 was soaked for 15 hours, then prepolymerized by irradiating it with ultraviolet light for 1 minute using a 400W ultraviolet lamp in a nitrogen atmosphere, and then heated to 80°C. It was heat treated for 10 hours. The obtained lens had the same antifogging effect as Example 1.

Example 3 20 parts of 2-hydroxyethyl methacrylate, 60 parts of glycidyl methacrylate, 10 parts of triethylene glycol dimethacrylate, 10 parts of triethylene glycol monomethacrylate, bis-(4-t
- A porous glass similar to that in Example 1 was immersed in a mixed solution of 0.3 parts of (butyl cyclohexyl) peroxydicarbonate for 20 hours, and then in a nitrogen atmosphere.
Heat treatment was performed from 50°C to 70°C for 10 hours.

The obtained lens had the same antifogging effect as Examples 1 and 2.

Claims (1)

[Claims] 1. Impregnating a hydrophilic monomer into a porous glass having continuous pores produced by acid-treating phase-separated glass, and then polymerizing the hydrophilic monomer. A method for manufacturing an anti-fog lens characterized by: 2. The method according to claim 1, wherein the porous glass has a pore size of 50 to 2000 Å. 3. The method according to claim 1 or 2, wherein the hydrophilic monomer is selected from acrylic acid, monoacrylate acid, methacrylic acid, monomethacrylates, diacrylates and dimethacrylates. .