JPS61213114A - Manufacture of composite plastics - Google Patents

Abstract

PURPOSE:To prevent a deformation and distortion from generating by enabling laying of a film element into a predetermined position of the inside of resin, by a method wherein the film element is positioned by an annular spacer, which is made to polymerize and cure under a restrained state. CONSTITUTION:A second rigid mold 2 is fixed to the lower part of a stepped part 4a of a cylindrical elastic mold 4 by fitting the same tightly in the lower part of the stepped part 4a of the cylindrical elastic mold 4 and a film element 3 having the outside diameter which is larger than the inside diameter of the stepped part of the cylindrical elastic mold 4 and smaller than the outside diameters of the rigid molds 1, 2 is mounted on the upper part of the stepped part 4a. An annular spacer 6 whose inside diameter is about the same with the inside diameter of the stepped part of the cylindrical elastic mold 4 and the outside diameter is either about the same with those of the rigid molds 1, 2 or smaller a little than those is mounted above the film element 3 and the first rigid mold 1 is fixed above the annular spacer 6 by fitting the same tightly in the cylindrical elastic mold 4. A spatial part is made to fill with a resin monomer by casting the same through a casting port, which is made to polymerize and cure. As for the titled manufacture of the composite plastics, it is suitable for manufacture of the composite plastics and a decal transferring surfaces of the first and second rigid mold are fulfiled by making use of the rigid molds of a concave surface and convex surface to those of which arbitrary diopters have been given beforehand.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing composite plastics, in which a film element such as a polarizing film is positioned in a restrained state in a resin material for plastics, and then polymerized and cured. .

[Prior Art] Among plastics, especially transparent plastics, in addition to their own transparency, they are lightweight, and also have excellent impact resistance and ease of processing, so they can be used in various ways in place of conventional glass. Applied to transparent parts. In the field of transparent plastic applications, plastic lenses are rapidly becoming popular in place of glass lenses because they are lighter, safer, and can be dyed with dyes. be. As such transparent plastic materials, homopolymers of diethylene glycol bisallyl carbonate and (meth)acrylates, or copolymers mainly composed of them, have excellent transparency and abrasion resistance, and are also highly productive, so they are suitable for plastic lenses. It is put into practical use as a product.

-On the other hand, recently, as outdoor activities have expanded, demand for polarized lenses and photochromic lenses that have polarization and photochromic functions has increased as anti-glare eyeglass lenses.

In addition, the introduction of personal computers and office automation in offices and factory automation in factories are rapidly progressing, and eye strain due to the displays of workers involved with these computers, as well as mental fatigue that may be caused by this, is becoming a problem. It has become,
The use of anti-glare lenses, anti-glare screens, etc. for computer displays is becoming essential. Under these circumstances, in place of glass products, it is necessary to develop composite plastic products such as polarized lenses, photochromic lenses, and anti-glare screens made of plastic acid, which are lightweight, have excellent impact resistance, and are highly productive. is desired.

Conventionally, when manufacturing plastic acid polarized lenses, photochromic lenses, anti-glare screens, etc. using transparent plastic materials such as those mentioned above, film elements having functions such as polarization and light control are added to the resin monomer as the plastic material. It is well known that a method is adopted in which the membrane element and the resin are integrated by embedding the membrane element and polymerizing and curing it. That is, the thickness of the lens or screen formed by fitting two types of rigid molds with transfer surfaces suitable for forming a concave (or flat) surface and a convex (or flat) surface on the plastic to be molded. In the corresponding mold space,
The periphery of the membrane element is held and fixed in a restrained state by an appropriate method, and a resin layer is injected and filled into the space on both sides of the membrane element divided into two parts. After heating and polymerizing, a rigid mold is formed. Composite plastics are manufactured by removing.

However, according to this method, there is a problem that the membrane element is deformed during the polymerization and curing process, and the membrane element peels off in the thin portion of the resin layer, which causes a decrease in productivity. In addition, the produced composite plastic has the problem that distortion remains in the membrane element due to deformation of the membrane element, making it difficult to obtain a high-quality composite plastic.

Therefore, various methods have been proposed as improved manufacturing methods for the above-mentioned composite plastics. For example, in a method for manufacturing a compound lens,
A method of polymerizing and curing a film element smaller than the lens diameter by placing it in a resin layer in an unrestricted state (Japanese Patent Publication No. 58-38
(Refer to Publication No. 244), or the membrane element is placed on the protrusions for membrane element a provided at several places on the inner surface of the space of the cylindrical gasket, and the space is injected and filled with resin monomer and polymerized and cured. A method of manufacturing a polarized lens by the above method (Japanese Unexamined Patent Publication No. 187819/1983) has been disclosed.

[Problems to be Solved by the Invention] As mentioned above, the problem in the manufacturing method of composite plastics is the occurrence of deformation and distortion of the membrane element embedded inside the resin, and the accompanying deformation of the membrane element from the resin. It is peeling.

As a solution to this problem, in the above-mentioned improved method for manufacturing a composite lens, a membrane element smaller than the lens diameter is placed in an unrestrained state on a resin layer filled in advance in a rigid mold, and Although the method of filling resin monomer and polymerizing and curing it reduces the strain generated by the membrane element, the actual manufacturing process is extremely complicated;
High productivity cannot be expected. In other words, the resin monomer and the membrane element have different specific gravities, and unless they match, it is difficult to embed the membrane element in the appropriate position, and a special process is required to appropriately set the specific gravity relationship. There's a problem. Incidentally, the specific gravity of a film made of polyvinyl alcohol commonly used as a polarizing film is 1.20 to 1.25, whereas the specific gravity of a resin monomer such as diethylene glycol bisallyl carbonate is 1.14.
It is. Furthermore, if the above method is followed, the molded composite lens has a membrane element smaller than the lens diameter, so there is a part at the periphery where the membrane element is not embedded, and it is costly due to the grinding process of this part and the use of excess resin monomer. There is also the problem of disadvantages.

In addition, in the above-mentioned improved manufacturing method, the method of using a cylindrical gasket with a special shape on the inner surface for mounting the film element is also difficult to manufacture various types of polarized lenses due to the complicated design of the gasket. There is a drawback that it is inevitable that it will be disadvantageous in terms of cost because it involves manufacturing.

In view of these problems, the present inventors have researched and considered a method for easily manufacturing high-quality composite plastics with high yields, in which the membrane elements are buried in predetermined positions without being deformed inside the resin. As a result, we obtained the knowledge that the objective could be achieved by positioning the membrane element with a ring-shaped spacer with a simple structure and polymerizing and curing it in a restrained state.The present invention was developed as a novel method for manufacturing composite plastics. There are some people who have come to complete this.

[Means for Solving the Problems] In the present invention, the outer periphery of the first and second rigid molds having transfer surfaces is formed entirely by a cylindrical elastic mold having a stepped portion for fitting the rigid molds therein. In a method for producing a composite plastic which is formed into a mold and polymerized and cured by being composed of a resin monomer and a membrane element embedded inside the resin monomer, a second rigid mold is placed at the lower part of the step of the cylindrical elastic mold. A membrane element having an outer diameter larger than the innermost diameter of the cylindrical elastic gas gout and smaller than the outer diameter of the rigid mold is placed on the upper part of the first step, and a membrane element whose inner diameter is smaller than the outer diameter of the rigid mold is placed on top of the first step. The outer diameter is approximately equal to the step inner diameter of the cylindrical elastic mold, and the outer diameter is approximately equal to the outer diameter of the rigid mold.
Alternatively, a slightly smaller ring-shaped spacer is placed, and the first rigid mold is tightly fitted and fixed thereon, and the space is filled with resin monomer by injecting it from the injection port,
This is a method for producing composite plastics characterized by polymerization and curing.

In the manufacturing method of the present invention, the outer peripheries of the first and second rigid molds are molded all around with a cylindrical elastic mold, a membrane element is embedded inside the resin top mold, and the composite plastic is polymerized and hardened. This method is characterized by positioning the membrane element using a ring-shaped spacer with a simple structure and polymerizing and curing it in a restrained state. By this method, the membrane element is embedded at a predetermined position inside the resin, and a high-quality composite plastic can be obtained without deforming or straining the membrane element. Although the reason for this is not clear, it is thought that the ring-shaped spacer acts to restrain the deformation of the membrane element and absorb stress.

The method for manufacturing a composite plastic of the present invention is suitable for manufacturing a composite plastic lens.

This is achieved by the use of concave and convex rigid molds in which the transfer surfaces of the first and second rigid molds are pre-given an arbitrary diopter. Further, the transfer surface of the rigid mold is not limited to an uneven surface, and either one or both may be flat, and if both are flat, a composite plastic screen can also be manufactured.

The transfer surface of the rigid mold is an optically polished surface.
It is preferable for manufacturing lenses and the like.

Hereinafter, a method for manufacturing a lens using a method for manufacturing a composite plastic according to the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view of an assembled mold for manufacturing a composite plastic lens, and its structure and assembly process are as follows. First, the cylindrical elastic mold 4 has a rigid mold fitting step 4a integrally molded on its inner surface, which has an inner circumferential surface 4b, a rigid mold fitting surface 4c, and a membrane element mounting surface 4d. A second rigid mold 2 whose transfer surface has a convex surface 2a given a diopter in advance is brought into contact with the rigid mold fitting surface 4c from below the cylindrical elastic mold 4,
Next, on the membrane element mounting surface 4d of the rigid mold fitting step part 4a of the cylindrical elastic mold 4, it is tightly fitted with the convex surface 2a and fixed to the rigid mold fitting step part 4a of the cylindrical elastic mold 4. A membrane element 3 shaped to have the same curvature as the transfer surface of the rigid mold is inserted from above the cylindrical elastic mold 4 and placed thereon. The membrane element is formed in a cylindrical elastic mold 4
It is formed to have a diameter larger than the inner diameter of the rigid mold fitting step part 4a and smaller than the outer diameter of the rigid mold, so that it can be easily placed on the membrane element mounting surface 4d of the rigid mold fitting step part 4a. 6. Then, on top of the 1M element 3, the inner diameter is approximately equal to the inner diameter of the rigid mold fitting step 4a of the cylindrical elastic mold 4, the outer diameter is approximately equal to or slightly smaller than the rigid mold, and the inner periphery is A ring-shaped spacer 6 integrally formed with a surface 8a, a membrane element contact surface 6b, and a rigid mold placement surface 8C is placed. Furthermore,
A first rigid mold having a concave surface 1a whose transfer surface is given an arbitrary diopter is brought into contact with the rigid mold a placement surface 6C of the ring-shaped spacer 6 from above the cylindrical elastic mold 4, and the concave surface 1a and They are tightly fitted and fixed using a cylindrical elastic mold. Thereby, spaces 5a and 5b partitioned by the membrane elements are formed. The mold for manufacturing the composite plastic lens thus assembled is as shown in FIG. 2 in plan view.

Next, the first and second rigid molds are sandwiched and fixed by elastic bodies such as springs 7, and the membrane elements are restrained, and a pre-prepared thermopolymerizable or energy Inject the linearly polymerizable monomer through the injection port (not shown in Figures 1 and 2), being careful not to entrap air bubbles, especially at the interface with the membrane element. Fill it up. After confirming that no air bubbles remain in the filled resin monomer or at the interface with the membrane element, the injection port is sealed, and the rigid mold is held and fixed by springs 7 and polymerized by heating or energy ray irradiation. Let it harden.

After curing, the spring 7 and the cylindrical elastic mold 4 are removed, and the first and second rigid molds are removed to take out the polymer, so that the membrane element is formed into a brim shape as shown in FIG. 3. A composite plastic lens with a unique shape can be obtained. A composite plastic lens having such a shape cannot be formed by a known manufacturing method. The brim-shaped film element of the composite plastic lens thus manufactured is cut along the outer periphery of the lens molded body, and the peripheral portion is processed and finished (1), for example, by being lightly polished, so that the film element is embedded in the entire surface of the lens. A composite plastic lens shown in FIG. 4 is obtained.

In the present invention, in the method for manufacturing a composite plastic lens described above, it is of course possible to manufacture the composite plastic lens by reversing the fitting positions of the first and second rigid molds to the cylindrical elastic mold.

The desired lens thickness as a composite plastic lens is
Inner peripheral surface 4 of the rigid mold fitting step part of the cylindrical elastic mold
b, the thickness of the inner circumferential surface 8a of the ring-shaped spacer, and the thickness of the membrane element 3, and these can be arbitrarily selected. Moreover, the buried position of the membrane element can also be set to a desired position by arbitrarily selecting the respective thicknesses of the inner circumferential surface 4b of the rigid mold fitting step and the inner circumferential surface 8a of the ring-shaped spacer.

In the present invention, it is appropriate to use a conventionally used rigid mold made of glass, and the external shape can be any shape desired for the composite plastic, such as a circle, oval, square, or other polygon. The outer shape of the cylindrical elastic mold is not particularly limited as long as it can fit tightly around the entire circumference of the rigid mold according to the shape of the rigid mold, but The inside of the cylindrical elastic mold, which preferably resembles the outer shape of the rigid mold in some respects, has a rigid mold fitting step 4a, as shown in FIG.
However, it is preferable that the rigid mold fitting surface 4c of the stepped portion be provided with a slope that matches the curvature of the transfer surface of the rigid mold in order to prevent leakage of the resin monomer. It is preferable that the membrane element mounting surface 4d is also provided with a slope that matches the curvature of the membrane element.The material of the cylindrical elastic mold needs to be one that cannot be dissolved in the resin monomer. Examples of such elastic materials include synthetic rubber, ethylene-acid picopolymer, and polypropylene blended with ethylene-acid picopolymer.

The outer shape of the ring-shaped spacer is selected depending on the shape of the rigid mold, but its structure is extremely simple.

Its cross-sectional shape is rectangular as shown in FIG. Further, the membrane element mounting surface 6b and the rigid mold mounting surface 6c are preferable from the viewpoint of ease of processing and finishing the peripheral edge.
It is preferable that the ring-shaped spacer is made of a cylindrical elastic mold.The material of the ring-shaped spacer is preferably a cylindrical elastic mold. It is preferable to use one of the same quality.

The membrane elements are made of various materials having functions suitable for use as composite plastics.For example, as a polarizing film, a polyvinyl film that gives a polarizing effect such as a stretched or dyed film of polyvinyl alcohol, A sheet or the like is used. These are molded to have a curvature that matches the curved surface given to the transfer surface of the rigid mold, and the surface of the membrane element is surface-treated to improve adhesion. Good too.

As the resin monomer, for example, methyl methacrylate, styrene, diethylene glycol bisallyl carbonate, diallyl phthalate, etc., which give a transparent resin, are used alone or in combination, and a suitable thermal polymerization initiator or ultraviolet curing catalyst is mixed and dissolved. It is prepared by

It is also possible to use a prepolymer that has been prepolymerized in advance to the extent that it does not interfere with injection and filling.

[Example] Next, a typical method for manufacturing a composite plastic of the present invention will be specifically explained with reference to Examples, but it goes without saying that the present invention is not limited only to the Examples.

Example 1 Diameter 75++ with convex surface equivalent to 5.00 diopters
A circular second rigid mold 2 made of glass with a size of
It is inserted from below the cylindrical elastic mold 4 made of ethylene-vinyl acetate copolymer integrally molded into the mold, and is brought into contact with the mold fitting surface 4c of the fitting step, and is tightly fitted into the cylindrical elastic mold. On the membrane element mounting surface 4d of the fitting step part of the 0-order cylindrical elastic mold referred to in FIG. A polarizing film 3 made by A. Co., Ltd. was cut into a circular shape with a diameter of 74 mm and placed thereon. Furthermore, a ring-shaped spacer 6 made of ethylene-vinyl acetate copolymer molded to have an inner circumferential surface 6a with a thickness of 1 mm, an inner diameter of 70 cm, and an outer diameter of 74 m1 is placed, and a concave surface equivalent to 4.9133 diopters is placed on top of it. What diameter does it have? A 5+sm glass circular first rigid mold 1 is inserted from above the cylindrical elastic mold,
It was mounted and tightly fitted into a cylindrical elastic mold.

The rigid mold is clamped and fixed by the spring 7,
A diethylene glycol bisallyl carbonate monomer prepared by mixing and dissolving a thermal polymerization initiator in advance is injected into the spaces 5a and 5b from the injection port to ensure that no air bubbles are trapped. After confirming this, the injection port was sealed, and the mixture was placed in a heating polymerization furnace, and the temperature was gradually raised from 30° C. to 80° C. over 18 hours to polymerize and harden.

After slow cooling, the mold was released and a polymer as shown in FIG. 3 was taken out. The flange-shaped polarizing film was cut and the peripheral edge was rubbed to obtain a polarized plastic lens.

As a result of measuring the optical properties of the obtained polarizing plastic lens, the refractive power was 0.00 diopter, the transmittance of visible light was 40 to 60%, and the degree of polarization was 80 to 97%. Furthermore, when this lens was cut along the center line and the position of the polarizing film was confirmed, it was located 1 mm from the surface of the convex spherical surface, which was the originally designed position, and was buried in the correct position without any fluctuation or deformation. Ta.

[Effects of the Invention] According to the manufacturing method of the present invention, there is no deformation or distortion of the composite plastic membrane element manufactured as in the conventional example, and of course, there is no peeling of the membrane element from the resin. Instead, the membrane element is embedded exactly inside the resin in its original design position. Therefore, it has the effect that high quality composite plastics can be manufactured with high productivity.

Furthermore, the produced composite plastics usually require finishing of the periphery, especially grinding and polishing of the resin, which results in loss of resin, but the finishing of the periphery of the composite plastic produced by the method of the present invention is extremely simple. Moreover, there is no loss of resin, and therefore, it is recognized to be effective in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an assembled mold in the method for manufacturing a composite plastic lens according to the present invention, FIG. 2 is a plan view showing the assembled mold, and FIG. 3 is a cross-sectional view showing the assembled mold, and FIG. A sectional view of the composite plastic lens immediately after, and FIG. 4 is a sectional view of the same completed composite plastic lens. 1--First rigid mold, 2--Second rigid mold, 3--One film element (polarizing film), 4--One cylindrical elastic mold, 4a-m-Rigid mold fitting step part , 4b--11 step part inner peripheral surface, 4C--1 step part rigid mold contact surface, 4
d--One step membrane element storage surface, 6--ring-shaped spacer, 6a-m-spacer inner peripheral surface, 6b-m-spacer membrane element contact surface, 8cm--spacer rigid mold i & placement surface, 5a, 5b--One space.

Claims (3)

[Claims] (1) The outer peripheries of the first and second rigid molds having transfer surfaces are molded over the entire periphery by a cylindrical elastic mold that has a step inside for fitting the rigid molds, and the resin monomer and the resin monomer are molded together. In a method for producing a composite plastic that is polymerized and cured by a membrane element embedded inside, a second rigid mold is tightly fitted and fixed at the lower part of the stepped part of the cylindrical elastic mold, and a cylindrical part is fixed to the upper part of the stepped part of the cylindrical elastic mold. A membrane-like element having an outer diameter larger than the inner diameter of the stepped part of the cylindrical elastic gasket and smaller than the outer diameter of the rigid mold is placed thereon, and a rigid mold whose inner diameter is approximately equal to the inner diameter of the stepped part of the cylindrical elastic mold and an outer diameter is placed thereon. Place a ring-shaped spacer that is approximately equal to or slightly smaller than the outer diameter of the
Furthermore, a first rigid mold is tightly fitted and fixed thereon, and a resin monomer is injected into the space through an injection port to fill the space, and then polymerized and hardened. (2) The method for manufacturing a composite plastic according to claim 1, wherein the composite plastic is a plastic lens. (3) The method for manufacturing a composite plastic according to claim 1 or 2, wherein the first and second rigid molds are rigid molds having concave and convex transfer surfaces.