JP2001353747A - Method for manufacturing optical laminated molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish manufacturing technique for economically cope with a desired subject such that the development and production of polarizing lenses having a high degree of polarization, having various lens colors, shapes and light transmissivities and comprising various materials are desired accompanied by the recent increase in use polarizing optical lenses. SOLUTION: A polarizing sheet for an LED having a degree of polariziation of 99.0% or more and a total light transmissivity of 40% or more and a plastic film comprising a material bonded to a target lens material in a molten state and having high light tranmissivity are bonded by an adhesive. This bonded sheet is subjected to press molding so as to form into the same shape as the outer surface of a target lens in such a state that the melt adhesive plastic surface of the sheet becomes inside and this press piece is inserted n a target lens mold and lens molding resins having various colors or adjusted to various transmissivities are injected in the mold to manufacture various polarizing optical lenses. That is, by selecting a molding resin and the plastic film corresponding thereto while using one kind of a polarizing film, various optical polarizing lenses can be manufactured economically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a method for manufacturing an optical spectacle lens having a high degree of polarization, and forms a sheet obtained by laminating a polarizing sheet and various plastic films by hot pressing. Then, by inserting this into the mold of the injection molding machine, polarized lenses of various materials can be molded, and by mixing various pigments etc. into the resin used for molding, one type of polarizing sheet can be used. And a variety of polarized lenses can be manufactured.

2. Description of the Related Art Polarized lenses using glass have been manufactured for a long time, and are bonded by pressure bonding between two glass lenses using an adhesive. However, in recent years, various plastic lenses have been used to reduce the weight of eyeglasses and to provide safety to the eyes due to breakage. A typical example is a polarized lens formed by injection molding using CR-39. This is generally called a casting method, in which a polarizing film preformed in a spherical shape is mounted in a gap formed by a mold having a concave surface and a convex surface (Japanese Patent Publication No. 53-29711). Also,
In Japanese Patent Publication No. 50-3656, there is a manufacturing method in which thermoplastic resins having different thicknesses are laminated on both surfaces of a polarizing thin film, and this is press-molded. Japanese Patent Publication No. 61-5609 discloses a method of manufacturing a molded lens characterized by using a polarizing sheet in which a polarizer is directly adhered to a fusible material. Further, Japanese Patent Publication No. 7-94154 discloses a polycarbonate lens on both sides of a polarizing thin film. A method of manufacturing a polarizing polycarbonate lens by laminating films or sheets to produce a laminate having a thickness of 1.5 to 2.5 mm, and subjecting the laminate to pressure and heat molding is shown. However, any of the above methods takes a long time to manufacture, or there is a problem in economy due to the special polarizing sheet used, and distortion occurs in hot bending molding from the sheet, or it meets various needs. Therefore, there are many problems that many colored sheets have to be used.

[Problems to be Solved by the Invention] The inventor of the present invention economically manufactures a high-level polarizing lens which can cope with various plastic materials developed in recent years, and furthermore, in order to cope with fashionability. The present invention contemplates a method for manufacturing a polarizing lens having various types of colors and light transmittances using one type of polarizing sheet.

[0004] In order to solve the above-mentioned various problems, the present inventor has developed a light transmittance using advanced technology for LCD, which has made great technical progress recently. High, and the degree of polarization is nearly 100%,
An optically transparent plastic film that is compatible with the target lens material on one side of a polarizing sheet sandwiching a polarizing film with a low color density and a cellulose triacetate film with a very high light transmittance on both sides Are laminated by using an adhesive, and the laminated sheet is molded into the same shape as the object to be molded by hot pressing, and the molded sheet is punched out. A solution has been found by a method of injection molding the objective lens material resin by inserting so as to be as follows.

The polarizing sheet usable in the present invention is produced by dyeing and stretching a polyvinyl alcohol film generally used as a base film with a dichroic dye having moisture and heat resistance. This is a sheet composed of a cellulose triacetate film having excellent optical transparency and sandwiched on both sides using an adhesive, the total thickness of which is 0.2 mm or less, and the total light transmittance of the sheet is 0.2 mm or less. A polarizing sheet having a polarization degree of 40% or more and a polarization degree of 99.0% or more can be used. The reason why the total thickness is 0.2 mm or less is that if the total thickness is 0.2 mm or less, it becomes easy to maintain the total light transmittance at the target of 40% or more, and the material cost is the most economical.

A plastic film having a total light transmittance of 80% or more and a thickness of 0.3 mm or less and a thickness of 0.1 mm or more is basically compatible with a molding resin as a main material constituting a lens. A film formed of a good material can be used as long as it has a fusibility. Generally, a film obtained by forming a film of a resin such as polyester, polyether, polyacryl, polycarbonate, polyamide, cellulose alone or a modified resin thereof can be used. If the film thickness in this case is 0.3 mm or more, heat bending is performed after laminating this film and the polarizing sheet. At this time, molecular distortion easily occurs in the film, and as a result, optical performance is reduced. Attempting to eliminate or even eliminate the distortion problem would increase the time required for hot bending, which would impair the economics of manufacturing. Therefore, it is preferably 0.2 mm or less. The reason why the thickness of the film is 0.1 mm or more is that a lens is molded by injection molding of a high-temperature lens molding resin after insertion into a molding die in a subsequent step. At this time, the film and the lens molding resin dissolve at the interface and are uniformly integrated, but when the film is 0.1 mm or less, the heat and pressure during molding of the lens molding resin and the resin flow in the mold. This is to break the polarizing sheet outside the film by shearing the film. Preferably 0.12 mm from the viewpoint of safety
Above is good.

As an adhesive for bonding the polarizing sheet and the plastic film, the adhesive has not only high transparency but also elongation to withstand a heat bending process, heat resistance to withstand molding, and performance capable of coping with various lens use conditions. Adhesive is required. In addition, it is necessary that the adhesive be capable of imparting an adhesive force that withstands mechanical strength between various plastic films and cellulose triacetate of a polarizing sheet. In the present invention, in order to obtain these properties, a polyester resin or a polyether urethane resin having an average molecular weight of 10,000 or more and 200,000 or less, and a polyol mainly composed of a polyester polyether urethane resin and the like, and a polyether as a crosslinking curing agent. A two-part curable adhesive containing isocyanate can be used.

As the resin material for molding a lens, a polycarbonate resin, a polyacryl resin, a polyamide resin, a cellulosic resin, a polyester resin, a polyarylate resin and the like can be selectively used according to the purpose.

[Embodiment of the Invention] An embodiment of the invention will be described in detail based on an embodiment. Example 1 Example 1 Obtained by bonding a 0.08 mm cellulose triacetate film to both surfaces of a 0.02 mm thick polarizing film made of polyvinyl alcohol having a degree of polarization of 99.95% using an iodine dye. A polarizing sheet (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumikaran SQ-1852AP) having a thickness of 0.18 mm and a total light transmittance of 43.7% and a polycarbonate film having a total light transmittance of 92% and a thickness of 0.15 mm. Are bonded and laminated using a two-component curing type polyether polyurethane. The thickness of the obtained sheet is about 0.
34 mm. This sheet is press-molded at 135 ° C. for 2 minutes using a concave-convex hot press mold having the same shape as the target lens mold with the polycarbonate side as the concave side, and the molded part is die-cut. The obtained die-cut product was mounted in a mold of an injection molding machine for lens molding, and a polycarbonate resin for lens molding was injection-molded to obtain a target polycarbonate polarized lens. The polarizing sheet part of this lens is composed of a polycarbonate film, which is a bonding part of the polarizing sheet, and a polycarbonate for molding a lens in a molten state, forming a strong integral molded product. I got it. The degree of polarization of this lens was 99.0% or more, and its total light transmittance was 40.0%. Example 2 In Example 1, pigment coloring was performed on the polycarbonate resin for lens molding, and molding was performed in the same manner as in Example 1 using a resin having a total light transmittance of 60%. A color polarizing lens having a polarization degree of 25% and a polarization degree of 99.0% was obtained. Example 3 The same polarizing sheet as that of Example (manufactured by Sumitomo Chemical Co., Ltd .: trade name: Sumikaran SQ-1852AP) and a thickness of 0.18 m
m, and a polyester film having a total light transmittance of 85% was bonded and laminated using a two-component curable polyester polyurethane resin. The sheet was subjected to heat and pressure molding at 130 ° C. for 2 minutes using a hot press molding machine having an irregular surface having the same shape as the intended lens mold. The obtained molded sheet was punched out, inserted into a molding die of an injection molding machine in the same manner as in Example 1, and an optical polyester resin was injected and molded to obtain an optical polyester polarized lens. This lens has a degree of polarization of 9
The light transmittance was 9.2% and the total light transmittance was 39.5%. [Effects of the Invention] As is apparent from the above detailed description and Examples, the optical polarizing lens obtained by the manufacturing method of the present invention is easier to mass-produce than conventional products,
In the past, the materials involved in its production had been prepared with expensive polarizing sheets colored in various colors.
Since it can be dealt with simply by coloring the resin for lens molding, it has succeeded in economically producing a lens with a high degree of polarization.

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Claims (1)

[Claims] 1. A polarizing sheet having a thickness of 0.2 mm or less and a polarizing film formed by sandwiching a cellulose triacetate film from both sides with an adhesive, and having a total light transmittance of 40% or more and a degree of polarization of 99%. A polarizing sheet having 0.0% or more and a plastic film having a total light transmittance of 80% or more and a thickness of 0.3 mm or less and a thickness of 0.1 mm or more are laminated using an adhesive, and this laminated sheet is molded. The polarizing sheet is molded by hot press processing so that the cellulose triacetate surface of the polarizing sheet becomes an outer surface in a shape close to the outer shape of the product, and after inserting this into the inner surface of the mold, a lens molding resin material that is fused with the plastic film is formed. A production method for producing an optical laminated molded product having the desired polarization performance by injection molding.