JP2008132783A - Production process of resin lens and resin lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To complement demerits of an episulfide resin, in a resin lens production process which uses at least two different kinds of resin material including the episulfide resin. <P>SOLUTION: A resin lens with (a) a luminous transmittance better than episulfide resin, (b) an impact resistance better than episulfide resin, (c) a susceptibility to dyeing or (d) machining properties better than episulfide resin is obtained by: making at least one resin material, among at least two resin materials including the episulfide resin, into a molded body with no fluidity or no finished lens properties in itself; forming a cavity on its face to be adhered; injecting a resin material different from the resin material into the cavity and polymerization curing in the cavity to produce a resin molded body, in which at least two resin materials are mutually adhered and integrated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a resin lens and the lens, and more particularly, to a resin lens in which chemical, physical properties, cost, etc. are improved by molding using at least two kinds of materials.

  The resin lens is generally manufactured by injecting a flowable optical resin into a mold and curing it, and is composed of one type of optical resin. Optical resins are lighter than glass and are excellent in dyeability, impact resistance, machinability and the like, but resins having excellent optical properties are not necessarily excellent in other properties. Therefore, in the development of optical resins, efforts are made to improve the various characteristics of the lens in a well-balanced manner, but it is impossible to satisfy all with one type of resin. For example, hard resin has fragile properties on one side, so it is difficult to machine, and even with a high refractive index, the Abbe number and dyeability are low, resulting in chromatic aberration and lack of fashion. There are merits and demerits, such as defects, excellent impact resistance, but low scratch resistance. To make up for these drawbacks, it is conceivable to attach two lenses to form a two-layer structure, but it takes time and effort to match the optical axis and the joint curved surface, resulting in an increase in price.

On the other hand, in order to improve the added value of a resin lens, it has long been performed to laminate thin films having various effects. For example, a hard coat layer may be laminated or a photochromic layer may be laminated to improve the scratch resistance. As prior art documents related to the present invention, JP-A-60-205401 and JP-A-8-216271 can be mentioned. The former describes a method in which an aspherical lens is integrally molded by injecting a resin into a glass lens previously molded by an injection molding method. However, this technique does not compensate for the disadvantages of the optical or chemical properties of the glass lens itself, but improves the mass productivity by changing the shape. In the latter case, after molding the resin lens in the same manner, one side of the mold used at the time of molding is released, a cavity is formed, a photochromic material is injected into this cavity, and the resin lens is molded integrally. It is described that a photochromic layer is formed on one side. From these prior arts, it is recognized that it is well known to form a cavity on one side of a pre-molded molded article and to inject another resin into this cavity and form it integrally. However, all of these are based on the premise that the properties of the lens serving as the base material are utilized as they are, and by using a combination of two or more types of resin materials having different properties, the drawbacks of the lens itself serving as the base material are compensated. This idea is not shown in any literature.
Japanese Patent Laid-Open No. 60-205401 JP-A-8-216271

  On the other hand, the present invention is intended to compensate for the drawbacks of optical resins and thereby improve the optical characteristics or physical or chemical properties of the lens itself.

The manufacturing method of the present invention is a method of manufacturing a resin lens using at least two types of resin materials having different properties including an episulfide resin, and flows at least one type of resin material out of at least two types of resin materials. The molded product does not have the performance as a finished product lens, and a cavity is formed on the adherend surface of the molded product, and a raw material of a different type from the resin material is injected into the cavity. Then, a lens that satisfies at least one of the following conditions (a) to (d) is obtained by polymerizing and curing in the cavity to obtain a resin molded product in which at least two kinds of resin materials are in close contact with each other. Shall be manufactured;
(A) By using a resin having a lower refractive index than the episulfide resin as one of the resin materials other than the episulfide resin, the luminous transmittance is improved compared to the episulfide resin.
(B) By using a resin having higher impact resistance than episulfide resin as one of resin materials other than episulfide resin, impact resistance is improved than episulfide resin.
(C) By using a dyeable resin as one of the resin materials other than the episulfide resin, it is possible to dye.
(D) By using a resin that is less prone to defects such as burrs and cracks than the episulfide resin as one of the resin materials other than the episulfide resin, the machining characteristics are improved as compared with the episulfide resin.

  In the present specification, “polymerization adhesion” means that a monomer adheres to a molded body in the course of polymerization without using an adhesive or a coupling agent.

  In the above, “a molded body that does not have flowability of at least one type of resin material and does not itself have a performance as a finished lens” means that when the material is a resin, it is a monomer or a molten material. Naturally, the material has fluidity and does not exhibit a stable shape. Therefore, it is necessary to first heat or irradiate or cure light rays (electromagnetic waves) such as ultraviolet rays, infrared rays, etc. Show. The shape of the molded body varies depending on the purpose of use. They may be referred to as “intermediate members”. Moreover, the said molded object also includes the film etc. which have special optical characteristics.

  A resin molded product obtained by closely adhering another resin monomer to the molded body can be used as a finished lens itself, but it is necessary to obtain a finished lens by processing such as grinding and polishing or cutting. It may be a semi-finished lens.

  In the present invention, lenses having different properties complement each other can be obtained by combining and integrating materials having different properties as described above. However, the selection of the resin is not limited to these, and any combination of materials that are superposed on each other may be used.

  When a resin that is more easily dyeable than an episulfide resin is used, the lens can be colored by mainly dyeing the easily dyeable resin. That is, a molded object made of a hardly dyeable resin and a dyeable resin are polymerized and adhered to one side of the molded article to form a part of the lens, and coloring it seems that the hardly dyeable part is colored. Can show. The sulfur-containing resin having an episulfide group has a refractive index of 1.74, which is the highest at present, but has poor dyeability. According to the present invention, it is possible to easily obtain a colored lens while complementing the drawbacks of such a high refractive index optical resin.

  In the case of using a resin in which defects such as burrs and cracks are likely to occur due to machining and a resin that is unlikely to occur due to episulfide resin, defects due to machining can be eliminated. In other words, hard resin lenses are prone to cracking when squeezing into a spectacle frame, and for spectacles with a method in which the spectacle frame is directly screwed to the lens with a bridge called two-point, There is a problem that burrs and cracks are likely to occur when processing a hole for inserting a screw into the lens, but a thin optical resin with good machinability is applied to at least one side of the intermediate member. By forming as, these problems can be solved. Specifically, the portion formed for this purpose is the front and rear surfaces of the lens or the periphery of the portion to be drilled.

  When a resin having a higher impact resistance than the episulfide resin is used, a lens having a high impact resistance can be obtained by complementing the weak point of the episulfide resin having a low impact resistance. That is, resin lenses with a high refractive index generally have low impact resistance, and in particular, high-refractive index episulfide resin with a refractive index of 1.74 has low impact resistance. It cannot be exceeded. According to the present invention, a thin layer of a resin having high impact resistance can be polymerized and adhered to pass the FDA standard 4 times test without further increasing the center thickness of the lens.

When a resin having a lower refractive index than episulfide resin is used, an optical resin having a lower refractive index among the high refractive index resin and the low refractive index resin is disposed on the air side, thereby reducing the surface reflected light and transmitting the light. The rate can be improved. The surface reflectivity R is given by the following Fresnel formula.
_{R = {(n g -n 0} ) / (n g + n 0)} 2

Here, _ng is the refractive index of the substrate, and n ₀ is the refractive index of air. This reflectance is similarly used at the interface between two types of optical materials. For example, when two types of optical resins are used and an intermediate member made of an optical resin having a refractive index of 1.5 and an optical resin having a refractive index of 1.74 are integrally molded, the air side and the interface between these resins The total reflectance of the lens is 4 + 0.55 = 4.55 (%), and the surface reflectance of the lens molded only with the optical resin having a refractive index of 1.74 is 7.3 (%). .75 (%) will be improved.

  Similarly, by arranging an optical resin having a low refractive index among the high refractive index resin and the low refractive index resin on the air side, occurrence of interference fringes can be prevented. In general, since resin lenses are easily scratched, a hard coat layer is formed to improve scratch resistance. However, the film thickness is about 1 to 2 μm, and if it is too thick, cracks and peeling occur due to volume expansion. For this reason, the reflected light from the surface of the hard coat layer and the lens surface interfere with each other to generate interference fringes, thereby significantly reducing the commercial value. This phenomenon is unlikely to occur when the refractive index of the hard coat substance and the lens resin are close to each other, but interference fringes become conspicuous as the difference in refractive index increases. Efforts have been made to increase the average refractive index by mixing fine particles of a high refractive index substance with the refractive index of the hard coat, but if mixed excessively, adhesion decreases and cracks due to temperature changes occur. 1.6 is the limit, and when the refractive index of the lens resin exceeds 1.7, interference fringes appear strongly. By arranging and integrating a resin having a lower refractive index on the surface of the high refractive index lens, this phenomenon can be avoided.

  According to still another embodiment of the present invention, an organic thin film having excellent scratch resistance and a thin film having an antireflection function are provided on one or both of the outer surfaces of the resin lens obtained by any one of the manufacturing methods described above. Either of these is provided. In addition to reducing the surface refractive index of the lens itself by combining optical materials, the light transmittance can be improved by providing an antireflection layer on the surface in contact with air. As a method of forming an organic thin film having excellent scratch resistance, a urethane resin in which inorganic fine particles are dispersed is dipped, applied to a film thickness of 1 to 2 μm by a spin coating method, and heated and cured, or an ultraviolet ray by an acrylic resin. Conventional means such as a method using a curable resin can be used. Further, as the thin film having an antireflection function, a multilayer metal thin film by sputtering or the like can be formed using a normal means.

  The lens obtained by the above-described method of the present invention is a lens in which preferable characteristics are selected and integrated from various optical resins, or because of excellent processability, a high-quality resin lens is inexpensive. It becomes possible to provide.

  Next, various embodiments of the present invention will be described.

The polymerization adhesion in each example will be described with reference to FIG. FIG. 1A is a cross-sectional view of a shell, in which a mold 1 having a concave use surface and a mold 2 having a convex use surface are bonded to the periphery of the mold so that the gap at the center is t _1. 4 to form a cavity 6a to produce a shell 10a. Next, as shown in FIG. 2B, the resin 3a is partially peeled off and injected into the cavity, sealed again, subjected to processing such as heat polymerization, and gradually cooled to cure the resin 3a. Let The cured resin 3 a becomes the intermediate member 3. FIG. 2C is a cross-sectional view showing the mold 2 that is released from the mold 1 and is in close contact with the intermediate member 3. FIG (d) is a gap in the center of the mold 1 and intermediate member 3 which is releasing the sealed with adhesive tape so that t _2, is a cross-sectional view of the shell 10b forming the cavity 6b. FIG. 4E is a cross-sectional view showing a shell 10c in which another resin 5a is injected into the cavity 6b. The resin 5a is cured by heat polymerization to form a resin 5 that is in close contact with the polymerization. FIG. 2F is a cross-sectional view showing the superposed contact lens 11 according to the present invention obtained by releasing the molds 1 and 2. The intermediate member 3 and another resin 5 are integrated to form a lens having a center thickness t.

  Even in the embodiments not described with reference to the drawings, the lens can be manufactured according to the above-described method. The resin materials (monomers) used are products of Mitsui Chemicals, except for those indicated by trade names.

[Example 1]
An example in which a resin lens capable of being dyed by polymerizing and adhering a hardly dyeable lens material and an easily dyeable lens material is shown.

  Prepare a glass mold with a diameter of 80 mm (hereinafter referred to as “mold”) in such a combination that the diopter is −7.00, and the mold center interval is 1.2 mm and 0.6 mm. The surroundings were sealed with adhesive tape to create two sets of shells. In these shell cavities, an episulfide resin monomer mixed with a catalyst (HIE, refractive index 1.74) was filled, and after heat polymerization, a shell mold having a center interval of 1.2 mm was released, A 7.00D episulfide resin lens was obtained. In the case of a shell having a distance of 0.6 mm between other central portions, only the mold on the convex surface side of the molded intermediate member was released, and the mold on the concave surface side was kept in close contact. Here, the mold on the convex side which has been released first is sealed again with adhesive tape so that the gap is uniformly 0.6 mm on the convex surface side of the intermediate member, and a cavity is formed. Was mixed with a urethane resin monomer (MR-7, refractive index 1.67), and the mold was released from both the convex side and the concave side after heat polymerization. In the obtained lens, a urethane resin layer having a uniform layer thickness of 0.6 mm was polymerized and adhered to the convex surface side of the intermediate member, and the center thickness was 1.2 mm.

  The two sets of lenses were immersed in a staining solution having a liquid temperature of 90 ° C. for 5 minutes. As a result, the episulfide resin lens was not dyed at all, and the dyeing density was 0%. However, in the polymerization adhesion lens of urethane resin and episulfide resin, the intermediate member of the episulfide resin was not dyed, but the layer thickness was 0.6 mm. When the urethane resin portion was dyed and measured with a spectrophotometer, the whole was dyed in the same manner as a lens dyed at a concentration of about 28%.

  As described above, the resin lens made of the hardly dyeable lens material is also modified to a resin lens capable of being dyed by polymerizing and adhering the easily dyeable lens material, and another material having a uniform layer thickness on the curved surface of the lens substrate. A lens can be manufactured so that a power change does not occur by polymerizing and adhering. In addition, the superposition | polymerization contact | adherence of a different material is not limited to the convex surface side of a lens base | substrate, A concave surface side may be sufficient. In this example, since the same mold is used at a position separated by 0.6 mm, the above urethane resin portion does not have a uniform layer thickness. However, as in this example, the radius of curvature is 600 mm and −7.00 D. In this case, the difference is 0.0013 mm at the peripheral part with a diameter of 80 mm, which is negligible.

[Example 2]
An example is shown in which a resin material that is easy to process is polymerized and adhered to a resin material that is difficult to machine, such as drilling, to improve a resin lens that is easy to machine.

  An intermediate member having a center thickness of 0.6 mm was prepared in advance using episulfide resin monomer (HIE) in the same manner as in Example 1, and a urethane resin monomer having good machining characteristics as described in Example 1 ( MR-7) was polymerized and adhered to the convex surface side of the intermediate member at a layer thickness of 0.6 mm to prepare a polymerized adhesion lens of episulfide resin and urethane resin.

  Generally, a lens used for a two-point type frame is cast into a predetermined shape and then drilled for screwing in the periphery of the lens. The lens was not damaged, and no burrs or chips were generated in the hole, and a clean hole could be processed. On the other hand, in the lens molded only with episulfide resin, since the position of the hole is close to the edge where the lens is processed, cracking occurs from the position of the hole to the edge, and the hole itself is also burred. It was generated and a clean hole could not be formed.

  As described above, the lens material that is difficult to machine and the lens material with good machinability are polymerized and adhered to form a polymerized adhesion lens, thereby reducing defects caused by machining and efficiently performing sophisticated machining. Can do.

[Example 3]
An example in which impact resistance is improved by polymerizing and adhering a material with high impact resistance to a material lens with low impact resistance (in this example, a lens coated with a hard coat and a multi-coat) will be described.

  Three molds each having a concave shape and a convex shape were formed for each of three shells by sealing the periphery of the mold with an adhesive tape so that the distance between the cavity central portions was 1.10 mm and 0.5 mm. Episulfide resin monomer (HIE) was filled in the cavities of the shells and polymerized by heating. After the heat polymerization, three sets of concave and convex molds having a cavity center interval set to 1.10 mm were released, and the lens center thicknesses were 1.12 mm, 1.16 mm, and 1.17 mm, respectively. An episulfide resin lens having a refractive index of 6.00D and a refractive index of 1.74 was obtained. On the other hand, only three concave molds were released from the three sets of shells in which the distance between the cavity central portions was set to 0.5 mm, and an intermediate member with the mold attached to the concave surface side was obtained. The center thicknesses of these lens bases were 0.47 mm, 0.47 mm, and 0.50 mm, respectively. Further, the cavity is formed by sealing the periphery of the mold with an adhesive tape so that the gap at the center is 0.6 mm in the mold of the concave shape that has been released first on the convex surface side of these intermediate members. Created a shell. Urethane resin monomer (MR-7) was filled in the cavities of these shells and polymerized by heating. After the heat polymerization, the respective concave and convex molds were released to obtain three polymerized adhesion lenses in which urethane resin was polymerized and adhered to the intermediate member of episulfide resin. The center thickness of each polymerization contact lens was 1.13 mm, 1.13 mm, and 1.18 mm.

  In order to impart scratch resistance to the six lenses described above, an organic hard coat coating process was performed, and then an antireflection coating process of the metal thin film was performed. A drop ball test according to the FDA standard test was performed on the six completed lenses. The results are shown in Table 1.

  As is apparent from the table, in the lens made only of the episulfide resin, the steel ball penetrated the lens in the first or second test in the test four times the FDA standard test. On the other hand, a polymerized adhesion lens in which a urethane resin having a layer thickness of 0.64 to 0.68 mm was polymerized and adhered to the convex surface of an intermediate member made of episulfide resin was subjected to the same falling ball test. It was only generated and did not penetrate. Thus, a highly refractive resin lens excellent in impact resistance can be produced by polymerizing and adhering a high impact resistance urethane resin to an episulfide resin lens that is brittle in impact resistance.

  The FDA standard test is for a 16.2 g steel ball to drop naturally from a height of 1.27 m onto the lens surface and break the lens (when the steel ball penetrates the lens or the lens separates into two or more pieces. ) Is a test to check if the lens is broken, it is rejected if the lens is broken, and a star (if cracked in a star shape) indicates a pass. The FDA quadruple test means a test using a steel ball in which the weight of a 16.2 g steel ball is quadrupled to 64.8 g.

[Example 4]
The case where the surface reflectance is reduced by polymerizing and adhering the low refractive index resin material to the intermediate member using the high refractive index resin material will be described.

  A high refractive index lens has a high YI value due to high temperature polymerization due to the characteristics of the material, and the amount of UV absorber added to the raw material is increased in order to improve the UV absorption function. The value (yellowness) increases. Further, as the refractive index of the material itself increases, the luminous transmittance in the visible light region decreases because the surface reflectance of the material itself increases. As a result of diligent examination of these problems, it has been found that the YI value can be lowered and the luminous transmittance in the visible light region can be increased by polymerizing and adhering a low refractive index material to a high refractive index material lens. An example is shown below.

  The periphery of the concave and convex molds was sealed with an adhesive tape, and a shell having a central gap of 1.2 mm was produced. In addition, two sets of shells having the same configuration and a gap of 0.5 mm at the center were prepared, and the following materials were mixed and filled in the cavities of these three sets of shells.

(A) thioepisulfide monomer (HIE-1) as monomer 90 parts thiol monomer (HIE-2) 10 parts (b) N, N-dimethylcyclohexylamine as polymerization catalyst 0.04 parts N, N-dicyclohexylmethylamine 0.1 part acetic anhydride 0.08 part (c) Seesorb 704 (manufactured by Sipro Kasei Co., Ltd.) 3.0 part as an ultraviolet absorber

  After heat polymerization of the filled shell, the concave and convex molds with a center gap of 1.2 mm are released to release a high refractive index lens with a center thickness of 1.17 mm and a refractive index of 1.74 ( A prototype lens 1) was obtained.

  For the shell having a gap of 0.5 mm at the center, only the concave mold was released to obtain an intermediate member having a center thickness of 0.49 mm. The intermediate member was kept in close contact without releasing the convex mold. Next, on the convex surface side of this intermediate member, a uniform mold with a central gap of 0.7 mm is made using a concave mold that has been released first, and the periphery of the mold is sealed with adhesive tape to form a cavity. Two shells were made. The following materials were mixed and filled in the cavity of one of the shells.

(D) As a monomer,
Polyisocyanate (MR-7A) 52 parts Polythiol (MR-7B) 48 parts (e) As a polymerization catalyst,
Dibutyltin dichloride 0.10 parts (f) As an ultraviolet absorber,
Benzotriazole 1.5 parts

  After heat-polymerizing the filled shell, both concave and convex glass molds were released to obtain a lens. This lens is a lens in which an optical material having a refractive index of 1.67 is polymerized and adhered to a convex surface of an intermediate member having a refractive index of 1.74 and a center thickness of 0.49 mm with a layer thickness of 0.66 mm. Is a high refractive index lens (prototype lens 2) of 1.15 mm.

  In another shell made in the same shape, the following materials were blended and filled into the shell cavity.

(A) As a monomer,
Polyisocyanate (MR-8A) 50.5 parts Polythiol (MR-8B) 49.5 parts (b) As a polymerization catalyst,
Dibutyltin dichloride 0.1 parts (c) As an ultraviolet absorber,
Benzotriazole 1.5 parts

  After the shell filled with these materials was heated and polymerized, both concave and convex molds were released to obtain lenses. This lens is a lens in which an optical material having a refractive index of 1.60 is polymerized and adhered to a convex surface of an intermediate member having a refractive index of 1.74 and a center thickness of 0.49 mm at a layer thickness of 0.67 mm. Was a high refractive index lens (prototype lens 3) of 1.16 mm.

  Table 3 summarizes the properties of the prototype lenses 1, 2, and 3 described above. Each data is a numerical value based on a raw lens that is not subjected to coating processing such as hard coating or antireflection film on the lens surface. The spectrophotometer (made by Hitachi, Ltd.) was used for the measurement.

  The prototype lens 1 is a lens having a refractive index of 1.74, which is the highest as a high-refractive-index plastic lens currently on the market. However, a lens made of this high refractive index optical material has a problem in weather resistance, and a large amount of an ultraviolet absorber is added to the material in order to improve the weather resistance. As a result, it is a very high-accuracy UV-absorbing lens that substantially absorbs UV rays up to 400 nm and transmits only about 7% of UV rays at 400 nm. In addition, since the raw material is thioepisulfide resin (HIE), the polymerization requires a long period of polymerization at a high temperature part, and furthermore, a large amount of UV absorber is added to improve weather resistance. The influence of polymerization in the high temperature part is large, resulting in an increase in yellowness (YI value), and the prototype lens 1 has a YI value of 2.59. In addition, since the YI value and the material itself are high refractive index materials, the surface reflectance of the lens increases, and the luminous transmittance in the visible light region is 86.51%. The luminous transmittance of a plastic lens made of general diethylene glycol bisallyl carbonate resin is around 90%, and the YI value is 1.0 or less.

  In the prototype lens 2, the YI value and luminous transmittance of the prototype lens 1 described above are improved. The prototype lens 2 is obtained by polymerizing and adhering a 1.67 urethane resin having a refractive index lower than that of the base resin to the convex surface portion of the intermediate member having a refractive index of 1.74 as described above. Since the refractive index of the material adhered by polymerization is lower than that of the base material, the surface reflectance is lowered, and since the YI value is also lower than that of the base material, the luminous transmittance is 87.84% and the YI value is 2.33. Yes. The prototype lens 3 is obtained by polymerizing and adhering a urethane resin having a lower refractive index to the intermediate member, and shows better numerical values than the prototype lens 2 in terms of luminous transmittance and YI value.

  In this way, the YI value of the high refractive index material lens is obtained by polymerizing and adhering a material lower than the base material refractive index to the lens surface with a certain uniform layer thickness on the high refractive index material lens having a high YI value and surface reflectance. The value and luminous transmittance can be improved, and it is possible to provide a lens with high added value that is very transparent in appearance. In addition, it is not limited to one of the convex surface or the concave surface of the intermediate member to be polymerized and adhered to the intermediate member of the high refractive index material with a constant layer thickness. It becomes.

[Example 5]
An example will be described in which a material with less interference fringes is superposed and adhered to the lens surface of the material with much interference fringes.

  In general, when thin film processing such as hard coating is applied to the surface of a lens using a high refractive index material, interference fringes are generated. The cause of the occurrence is that the film thickness is not uniform during thin film processing on the lens surface, and if the lens is a high refractive index material, the refractive index of the hard coat film applied to the lens surface is the refractive index of the lens material. The rate may vary greatly. As a solution to this, a thin film is processed using a spin coater and processed to a uniform film thickness, or a metal oxide is used to make the refractive index of the hard coat film close to the refractive index of the lens material. It is conceivable to introduce fine particles into the hard coat solution. However, the production with a spin coater is not suitable for mass production of stock lenses and the like, and when metal oxide fine particles are introduced into the hard coat solution, the weather resistance adhesion between the lens surface and the hard coat film is difficult. There is a tendency to peel off. Under these circumstances, the present inventors have found a solution for preventing the occurrence of interference fringes by increasing the refractive index of the surface of the high refractive index lens closer to the refractive index of the hard coat solution, rather than increasing the refractive index of the hard coat solution.

  Prepare two sets of concave and convex glass molds with the same radius of curvature, and bond the periphery of the mold so that one set has a central gap of 0.6mm and the other set has 1mm. Two sets of shells were made by sealing with tape and forming cavities. Each cavity was filled with episulfide resin monomer (HIE) and subjected to heat polymerization. Thereafter, both the concave and convex glass molds of the shell having a cavity center of 1 mm were released to obtain a high refractive index lens having a center thickness of 1 mm, a refractive index of 1.74, and a power of −4.00 D. For the other set of shells having a central portion of 0.6 mm, only the concave glass mold was released to obtain an intermediate member, but the convex mold was kept in close contact.

  Next, the periphery of the mold is sealed with adhesive tape so that the gap between the center of the released concave mold and the center of the convex surface of the intermediate member is 0.4 mm, and a shell is formed by forming a cavity. did. This cavity was filled with a urethane resin monomer (MR-8) having a refractive index of 1.60, and after heat polymerization, both concave and convex glass molds were released to obtain lenses. That is, this lens is obtained by polymerizing and adhering a monomer having a refractive index of 1.60 having a uniform thickness of 0.4 mm to the convex surface side of an intermediate member having a refractive index of 1.74 and a center thickness of 0.6 mm.

  These lenses were coated by a dipping method using a hard coat liquid having a refractive index of 1.62 and heat-polymerized to form a hard coat layer, and then each lens convex surface was observed with a zircon lamp. The polymerized close-contact lens had no interference fringes and was a beautiful lens with a transparent feeling. On the other hand, the lens molded only with the episulfide resin is a lens that is difficult to see due to the conspicuous interference fringes. Both lenses have the same external shape, and the edge thickness and the center thickness are the same.

  Table 3 shows the results of the polymerization adhesion test for various optical materials. By selecting an appropriate material based on this list, a low-cost half-product lens can be manufactured. However, the resin material used in the present invention is not limited to the materials listed in Table 3, and may be any material that has optical characteristics as a lens and can be superposed and adhered to each other.

note. ○ Even if it was sandwiched with a vise, it was firmly in contact. × When it was sandwiched with a vise, the polymerization adhesion part was peeled off. Cloudiness The polymer in the monomer part was cloudy.

  In Table 3, MR-6, 7, and 8 are trade names of urethane resins manufactured by Mitsui Chemicals, HIE is a trade name of episulfide resins manufactured by Mitsui Chemicals, and CR-39 is PPG. It is a diethylene glycol bisallyl carbonate resin produced, PC indicates a polycarbonate resin, and PMMA indicates a polymethyl methacrylate resin.

  The resin lens of the present invention can be used as a high-performance spectacle lens, and according to the manufacturing method of the present invention, such a high-performance spectacle lens can be provided at low cost.

  That is, according to the present invention, a lens having excellent performance can be obtained by combining and integrating resins having different optical characteristics or other physical characteristics and chemical characteristics and compensating for the insufficient characteristics. Since different resin materials are closely adhered in the polymerization process and no optical adhesive or primer is required, special optical characteristics on the joint surface need not be considered.

1A is a cross-sectional view of the shell, FIG. 1B is a cross-sectional view of the shell filled with resin, FIG. 1C is a cross-sectional view of the intermediate member, and FIG. A sectional view in which another resin is injected into the cavity, FIG. 8E is a sectional view in which a resin different from the intermediate member is cast into the cavity, and FIG. 8F is a sectional view of the resin lens of the present invention. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Concave-shaped mold, 2 ... Convex-shaped mold, 3 ... Intermediate member 4 ... Adhesive tape, 10 ... Shell, 11 ... Polymerization adhesion lens

Claims (3)

A method for producing a resin lens using at least two kinds of resin materials having different properties including an episulfide resin,
Among the at least two types of resin materials, at least one type of resin material has no fluidity and itself is a molded body that does not have performance as a finished product lens,
By forming a cavity in the adherend surface of the molded body, injecting a raw material of a type different from the resin material into the cavity and polymerizing and curing in the cavity, at least two types of resin materials are adhered to each other. By obtaining an integrated resin molding,
A method for producing a resin lens, comprising producing a lens that satisfies at least one of the following conditions (a) to (d):
(A) By using a resin having a lower refractive index than the episulfide resin as one of the resin materials other than the episulfide resin, the luminous transmittance is improved compared to the episulfide resin.
(B) By using a resin having higher impact resistance than episulfide resin as one of resin materials other than episulfide resin, impact resistance is improved than episulfide resin.
(C) By using a dyeable resin as one of the resin materials other than the episulfide resin, it is possible to dye.
(D) By using a resin that is less prone to defects such as burrs and cracks than the episulfide resin as one of the resin materials other than the episulfide resin, the machining characteristics are improved as compared with the episulfide resin.   The method for producing a resin lens according to claim 1, wherein a urethane resin is used as one of resin materials other than the episulfide resin.   A resin lens manufactured by the manufacturing method according to claim 1.

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