JP2008068412A - Plastic lens manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic lens manufacturing method for efficiently manufacturing a plastic lens by preventing the occurrence of the cut powder of the plastic lens. <P>SOLUTION: The plastic lens manufacturing method includes a molding process S101 for cutting and grinding a semifinish mold formed of a thermoplastic resin to form the lens forming surface of a first mold, a mold assembling process S102 for opposing the first mold and a second mold to each other through a cavity and connecting the peripheral edges of the first and second molds to assemble a lens mold, a lens molding process S103 for injecting a raw material resin in the cavity of the lens mold to form the plastic lens and a regeneration process S104 for recovering the cut powder formed in the molding process and the first mold used in the lens molding process to regenerate a semifinish mold. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a plastic lens used for glasses or the like.

  2. Description of the Related Art Conventionally, a plastic lens manufacturing method is known in which a plastic lens raw material resin is injected into a lens molding mold prepared in advance to manufacture a plastic lens (for example, see Patent Document 1).

  The one disclosed in Patent Document 1 selects a semi-finished lens having a shape corresponding to prescription data of a customer's spectacle lens, and cuts and polishes the semi-finished lens based on numerical control processing data. A manufacturing method for manufacturing a lens is employed.

JP 2002-283204 A (see pages 4 to 8 and FIG. 1)

  By the way, in the conventional method for manufacturing spectacle lenses as described in Patent Document 1, there is a problem that a large amount of cutting powder is generated in a process of cutting and polishing a semi-finished lens. In general, since the raw material resin composition for forming the lens uses a thermosetting resin, these cutting powders cannot be reused, and if these cutting powders are discarded, there is a risk of adversely affecting the environment. There is also the problem of being. In addition, the cost of the raw material resin composition increases with the recent increase in the refractive index of the lens, and cutting a large amount of the semifinished lens also causes an increase in manufacturing cost. Furthermore, although a method of pre-manufacturing a plurality of glass molds according to the lens shape is also conceivable, it is difficult and inefficient to manufacture such glass molds after processing them in advance. There is a problem.

  In view of the above problems, an object of the present invention is to provide a method for manufacturing a plastic lens that prevents the generation of cutting powder from the plastic lens and efficiently manufactures the plastic lens.

The plastic lens manufacturing method of the present invention is a plastic lens for manufacturing a plastic lens with a molding mold formed by connecting a first mold and a second mold to each other and connecting outer peripheral edges of the first and second molds. The structure formed by thermoplastic resin is cut and polished, and at least one of the first mold and the second mold corresponds to the surface shape of the plastic lens. A mold forming step for forming a lens forming surface, a mold assembling step for assembling the molding mold by connecting the first mold and the second mold to each other and connecting outer peripheral edges of the first mold and the second mold; A plastic lens material resin is injected into the cavity of the molding mold, polymerized and cured, and a plastic is obtained. A lens forming step of forming a tick lens, characterized by comprising a.
According to this invention, in the molding process, the structure formed by the thermoplastic resin is cut and polished to form the lens forming surface, and at least one of the first mold and the second mold is created. . Then, in the mold assembly process and the lens molding process, the first mold and the second mold are combined to assemble a molding mold, and a plastic lens is molded using the molding mold. As a result, the plastic lens formed in the lens molding process is not cut and polished, so that no cutting waste of thermosetting resin is generated and the influence on the environment is eliminated. In addition, since there is no cutting of the plastic lens, it is possible to reduce the manufacturing cost in manufacturing the plastic lens. Furthermore, since at least one of the first mold and the second mold is molded with a thermoplastic resin, the mold molded with this thermoplastic resin and the cutting powder when cutting this mold are reused. It is possible to obtain environmental effects through recycling.

In the method for producing a plastic lens of the present invention, the structure is formed of a thermoplastic resin mixed with a fibrous inorganic substance or inorganic particles.
According to this invention, the said structure is formed using the synthetic resin which mixed inorganic substances, such as a fibrous inorganic substance or an inorganic particle, with the thermoplastic resin. As a result, even when the structure is heated and the surface hardness becomes soft, for example, these fibrous inorganic materials and inorganic particles prevent the thermoplastic resin molecules from moving on the structure surface. Can be prevented. Therefore, thermal deformation of the lens forming surface due to cutting and polishing in the molding process can be prevented, and a highly accurate lens forming surface can be generated.

In the plastic lens manufacturing method of the present invention, it is preferable that in the molding step, the structure is cut and polished to form the aspherical lens forming surface.
According to this invention, an aspherical lens forming surface is formed in the molding process. As described above, conventionally used glass molds have low processability, long processing time, and increased processing costs. On the other hand, in the semi-finished mold of the thermoplastic resin as in the present invention, the surface shape can be easily processed. Therefore, a lens forming surface can be formed flexibly corresponding to a lens forming surface having a complicated surface shape such as a progressive multifocal lens.

In the plastic lens manufacturing method of the present invention, the structure is supported by a surface opposite to the surface on which the lens forming surface is formed, and the processing device is configured to cut and polish the structure. It is preferable to provide a detachable structure support part.
According to this invention, the structure includes the structure support portion, and is attached to and detached from the processing apparatus by the structure support portion. For this reason, by attaching the structure support portion of the structure to the processing apparatus, it is possible to easily carry out the cutting and polishing work of the lens forming surface of the structure in the molding process. After forming the lens forming surface, this structure support The structure can be easily removed simply by removing the part. Therefore, the working efficiency of the molding process is improved.

Here, in the present invention, it is preferable that the structure support portion is integrally formed with the structure.
According to this invention, the structure support part and the structure are provided integrally. Thereby, when forming a structure, a structure support part can be integrally formed, for example by injection molding etc., and the operation | work which attaches or detaches a structure support part to a structure becomes unnecessary.

  Below, the manufacturing method of the plastic lens which concerns on this embodiment is demonstrated in detail using drawing.

[Plastic lens manufacturing method]
FIG. 1 is a flowchart of a plastic lens manufacturing method according to the present embodiment. FIG. 2 is a flowchart of a molding process in the plastic lens manufacturing method. FIG. 3 is a flowchart of the regeneration process in the plastic lens manufacturing method. FIG. 4 is a diagram showing an outline of the semi-finished mold in the blocking step of the molding step. FIG. 5 is a diagram showing an outline of the semi-finished mold in the outer diameter processing step (outer periphery shaping step) of the mold forming step. FIG. 6 is a diagram showing an outline of the semi-finished mold in the approximate machining rough cutting process of the mold forming process. FIG. 7 is a diagram showing an outline of the semi-finished mold in the finish cutting step of the mold forming step. FIG. 8 is a diagram showing an outline of the semi-finished mold in the mirror finishing process of the molding process. FIG. 9 is a diagram showing an outline of the semi-finished mold in the deblocking process of the molding process. FIG. 10 is a diagram showing an outline of the lens molding mold assembled in the mold assembling process. FIG. 11 is a diagram showing an outline of a plastic lens and a lens molding mold that have been released in the releasing step of the lens forming step. FIG. 12 is a diagram showing an outline of the pulverization step of the regeneration step. FIG. 13 is a diagram showing an outline of a thermoplastic resin blank that has been reblank in the base material forming step of the regeneration step. FIG. 14 is a diagram showing an outline of a thermoplastic resin blank that is re-blank into a semi-finished mold shape in the base material forming step of the regeneration step.

  In the plastic lens manufacturing method of the present embodiment, first, prescription data of a customer's plastic lens is acquired. For this purpose, for example, prescription data is input to a host computer (not shown) via input means by transmission from an online terminal or direct input. Then, the host computer transmits the input prescription data to a calculation computer (not shown), and the calculation computer designs a mold shape based on the prescription data and generates numerical control processing data. This numerical control machining data is constructed in a data structure having outer diameter machining data, approximate machining surface roughing data, finishing machining data, chamfering data, and the like.

  The outer diameter processing data is data used in an outer diameter processing step (outer periphery shaping step) S202, which will be described later, and an unnecessary outer peripheral portion of a semi-finished mold made of a thermoplastic resin is scraped to reduce the diameter to a predetermined outer diameter. It is processing data to do.

  The approximate machining surface rough machining data is data used in an approximate machining surface rough machining step S203, which will be described later, and is desired so as to cut the convex surface side of the semifinished mold so as to reduce the cutting margin in the finishing machining step S204 described later. This is processing data for creating an approximate surface shape that approximates the mold shape. More specifically, the approximate machining surface rough machining data is similar to a mold shape based on prescription data of a plastic lens, for example, and is a free curved surface shape for rough machining that is thicker by a predetermined dimension than the mold shape, or the final shape. The processing data is set so as to create the mold shape as an approximate surface shape. Here, it is preferable that the approximate processed surface rough machining data is numerically set so that an approximate surface shape in which the cutting margin in the finishing machining step S204 is 0.1 to 5.0 mm is formed.

The finish machining data is data used in a finishing machining process S204 described later. This finishing machining data is a prescription data of a plastic lens by cutting out a 0.1 to 5.0 mm cutting margin from the convex surface of the semi-finished mold having an approximate surface shape formed based on the rough machining data of the approximate machining surface. This is processing data for creating a precise mold shape.
The chamfering data is data used for a chamfering process S205 described later. This chamfering data is processing data relating to the chamfering of the edge of the processing surface of the semi-finished mold.

The numerical control machining data generated by the computer for calculation is transmitted to the host computer and recorded in a recording area (not shown) of the host computer so as to be appropriately readable.
In addition, although the example which produces | generates the processing data for numerical control with a computer for calculation is shown, it is not limited to this, You may produce | generate the processing data for numerical control with a host computer, Furthermore, in prescription data of a plastic lens, Alternatively, the numerical control machining data may be directly input to the host computer.

Thereafter, in the plastic lens manufacturing method of the present embodiment, the plastic lens is manufactured through each process as shown in FIG. That is, first, the semi-finished mold 100 (see FIGS. 4 to 8) as a structure made of a thermoplastic resin is processed to form the first mold 100A (see FIGS. 9 to 10) (mold forming step S101). . Thereafter, the lens molding mold 300 (see FIG. 10) is assembled by combining the molded first mold 100A and the previously formed second mold 200 (see FIGS. 10 and 11) (mold assembling step S102). Then, a plastic lens raw material resin is injected into the lens molding mold 300 assembled in the mold assembling step S102 to manufacture the plastic lens 400 (see FIG. 11) (lens molding step S103). After the lens molding step S103, the first mold 100A used for manufacturing the plastic lens and the semi-finished mold 100 generated in the mold molding step S101 are collected to generate a semi-finished mold (reproduction step). S104). In the present embodiment, a method for manufacturing an inner surface progressive multifocal lens is illustrated.
Hereinafter, each process S101-S104 is demonstrated in detail.

[Molding process]
The molding step S101 is performed based on numerical control machining data transmitted from the host computer by a shape creation device (NC machining machine) (not shown) provided to be communicable with the host computer. In the mold forming step S101, the first mold 100A is formed by processing the semi-finished mold 100 (see FIGS. 4 to 14) as a structure.

  Here, the semi-finished mold 100 is formed of a thermoplastic resin. The semi-finished mold 100 is injection-molded so as to be thicker than the finished thickness dimension by filling a mold with a softened thermoplastic resin by applying an injection pressure. In the present embodiment, the semi-finished mold 100 generates the first mold 100A having a convex surface that forms the concave surface side of the inner surface progressive multifocal lens. Therefore, the first mold 100A has a convex shape according to the shape of the first mold 100A. Although the semifinished mold 100 formed in the shape which has a shape surface is illustrated, it is not restricted to this. For example, when the second mold 200 (see FIG. 10) having a concave surface that forms the convex surface of the lens is generated, the semifinished mold 100 having a concave surface corresponding to the shape of the second mold 200 can be used. Further, both the first mold 100A and the second mold 200 may be formed from the semi-finished mold 100. In this case, for example, a cylindrical semi-finished mold may be used.

Moreover, as a thermoplastic resin which comprises the semifinished mold 100, what has the favorable mechanical strength and cutting workability which is disclosed by patent 3462249, for example can be utilized. Specifically, for example, polyphenylene ether, modified polyphenylene ether blended with polystyrene, aromatic polyester such as polyethylene terephthalate, polybutylene terephthalate, polybutylene naphthalate, polyphenylene sulfide, polyetherimide, polyether ether ketone, nylon 6, Examples thereof include thermoplastic polyamides such as nylon 6,6, nylon 4,6, and nylon MXD6, polysulfone, polyallylsulfone, polyethersulfone, and polythioethersulfone. Moreover, a thermoplastic resin may be used individually by 1 type, and may be used in combination of 2 or more type. When two or more types of thermoplastic resins having poor compatibility are used in combination, a known compatibilizer may be used.
Moreover, the thermoplastic resin which comprises the semifinished mold 100 contains the inorganic fibrous reinforcement as a fibrous inorganic substance. As this inorganic fibrous reinforcing material, for example, known materials other than glass fiber, carbon fiber, rock fiber and the like can be used. For example, fibrous potassium titanate, fibrous calcium silicate, fibrous magnesium borate, fibrous sulfuric acid Examples include whiskers such as magnesium, fibrous calcium sulfate, fibrous calcium carbonate, and fibrous aluminum borate. These inorganic fibrous reinforcing materials may be used alone or in combination of two or more.
In addition, it is good also as a structure which contains the inorganic particulate filler as an inorganic particle in a thermoplastic resin. In this case, examples of the inorganic particulate filler include talc, calcium carbonate, calcium pyrophosphate, and the like. These inorganic particulate fillers may be used alone or in combination of two or more. Further, the above-described inorganic fibrous reinforcing material and inorganic particulate filler may be used in combination.

  Such semi-finished molds 100 are pre-formed in a plurality of types corresponding to the shape of the plastic lens to be manufactured. In the molding process, one optimum semi-finished mold 100 is selected from the plurality of types of semi-finished molds 100 based on the numerical control processing data. That is, based on the numerical control machining data, the semi-finished mold 100 having a shape in which the cutting amount of the semi-finished mold 100 in the approximate machining surface rough cutting step S203 is minimized is selected. As this selection method, for example, a method of automatically selecting an appropriate semi-finished mold 100 based on machining data for numerical control may be used, or a method of manually selecting an optimal semi-finished mold 100 may be used. Good.

  Then, in the molding step S101, as shown in FIG. 2, the blocking step S201, the shape creation step S210, the mirror finishing step S206, the deblocking step S207, and the cleaning step S208 are added to the semifinished mold 100 selected as described above. The first mold 100A is generated by performing the above.

In the blocking step S201, as shown in FIG. 4, a block jig 120 as a structure support portion is attached to the selected semi-finished mold 100.
Specifically, in the blocking step S201, the block jig 120 is fixed to the surface opposite to the lens forming surface of the semi-finished mold 100 via, for example, a low melting point alloy 110. As this low melting point alloy 110, an alloy having a melting point lower than the melting point of the thermoplastic resin forming at least the semifinished mold 100 is used, and is bonded to the semifinished mold 100 and the block jig 120 by heat melting.
The fixing of the block jig 120 is not limited to the fixing with the low melting point alloy 110 as described above, and for example, an adhesive, a fastener, wax or the like may be used. Moreover, the semifinished mold 100 and the block jig 120 may be integrally formed of a thermoplastic resin, and in this case, the blocking step S201 can be omitted.
One end of the block jig 120 is connected and fixed to the semi-finished mold 100, and the other end of the block jig 120 polishes the semi-finished mold installation part and the semi-finished mold 100 (not shown) of a shape creation device (not shown) that cuts the semi-finished mold 100. It is detachably attached to a semi-finished mold installation section (not shown) of a polishing apparatus (not shown).
The semi-finished mold 100 to which the block jig 120 is attached is installed in the processing apparatus by, for example, detachably fixing the block jig 120 to a mold processing unit (not shown) of the processing apparatus.

In the shape creation step S210, the shape creation device creates the shape of the first mold 100A by cutting the semi-finished mold 100 based on the numerical control machining data. In this shape creation step S210, in order to prevent deterioration of workability and surface roughness due to the influence of heat generated during processing of the semifinished mold 100, it is preferable to perform wet processing using a cutting fluid or cutting oil. . The shape creation step S210 includes an outer diameter machining step (peripheral shaping step) S202, an approximate machining surface rough grinding step S203, a finishing grinding step S204, and a chamfering step S205.

  The outer diameter machining step (peripheral shaping step) S202 is a step performed at the beginning of the shape creation step S210, and based on the outer diameter machining data of the numerical control machining data, as shown in FIG. 5, a semi-finished mold The outer periphery of 100 is cut and reduced to a predetermined outer diameter L1.

  After this outer diameter machining step (outer periphery shaping step) S202, the shape creation device performs an approximate machining surface rough cutting step S203. In this approximate machining surface rough cutting step S203, as shown in FIG. 6, an approximate lens forming surface R1 having an approximate surface shape that approximates the surface shape of the plastic lens to be manufactured based on the approximate processing surface processing data of the numerical control processing data. Create. At this time, the approximate lens forming surface R1 is formed so that the thickness dimension difference between the approximate lens forming surface R1 and the lens forming surface R of the first mold 100A to be generated, that is, the surface roughness is 100 μm or less.

  Then, after this approximate machining surface rough cutting step S203, a finishing cutting step S204 is performed. In the finishing machining step S204, as shown in FIG. 7, the approximate lens forming surface R1 is cut based on the finishing machining data of the numerical control machining data to form the finished lens forming surface R2. At this time, the approximate lens forming surface R1 is created by cutting so that the finished lens forming surface R2 has a surface roughness of 0.1 to 10 μm.

  Thereafter, the shape creation apparatus performs a chamfering step S205. In the chamfering step S205, chamfering of the edge of the semifinished mold 100 is performed based on the chamfering data of the numerical control processing data. By this chamfering step S205, it is possible to prevent the edge of the semifinished mold 100 from being chipped after the finish cutting step S204, and to reduce the risk of sharp edges. When the second mold 200 is formed from the semi-finished mold 100, sharp edges are likely to be formed at the edges, so that it is possible to effectively prevent chipping of the edges by the chamfering step S205. When forming from the semi-finished mold 100, since a sharp edge is hard to be formed, the manufacturing method which abbreviate | omits chamfering process S205 may be taken.

  In the shape creation step S <b> 210 described above, the shape creation device collects cutting powder generated by cutting the semifinished mold 100 by the collection means. The collecting means is not particularly limited, but it is preferable to collect the cutting powder in a state where dirt or the like is not attached. Specifically, for example, a configuration in which cutting powder or cutting oil is collected through a filter and the cutting powder is collected, and a configuration in which the cutting fluid and cutting oil are separated and collected by a centrifugal separator can be raised. Further, when no cutting fluid or cutting oil is used in the shape creation step S210, a duct connected to a dust collector is provided near the machining portion of the machining process, and the cutting powder is collected using the negative pressure generated by the dust collector. Examples include the configuration. Here, the collected cutting powder is recycled in the regeneration step S104 described later.

And after shape creation process S210, a shape creation apparatus implements mirror surface finishing process S206. In this mirror surface finishing step S206, as shown in FIG. 8, the finish lens forming surface R2 of the semifinished mold 100 is polished using a scanning polishing tool 500 to create a lens forming surface R.
Here, the configuration of the copying polishing tool 500 will be described. As shown in FIG. 8, the copying polishing tool 500 includes a substantially container-shaped tool housing 510 and a rubber sheet 520 provided in an opening of the tool housing 510. The rubber sheet 520 is formed in a hemispherical shape having flexibility, and is provided in a state of closing the opening of the tool housing 510. In a sealed space formed between the tool housing 510 and the rubber sheet 520, for example, pressure gas or liquid is press-fitted. Thereby, pressure is applied to the rubber sheet 520 from the sealed space, and the hemispherical form of the rubber sheet 520 is maintained. Further, an abrasive cloth 530 such as a non-woven fabric is attached on the surface of the rubber sheet 520 opposite to the sealed space.
In the mirror surface finishing step S206, the copying polishing tool 500 is pressed against the semifinished mold 100 such that the finishing lens forming surface R2 of the semifinished mold 100 is brought into contact with the polishing cloth 530 of the copying polishing tool 500, or the semifinished mold 100 is semifinished. The finish mold 100 is pressed against the copying polishing tool 500, and the polishing liquid 540 is supplied between the semi-finished mold 100 and the rubber sheet 520, and at least one of the copying polishing tool 500 and the semi-finished mold 100 is rotated and rotated. Swing to perform mirror finish polishing. In the mirror surface finishing step S206 using such a copying polishing tool 500, the rubber sheet 520 contacts the finished lens forming surface R2 with uniform pressure, so that the finished lens forming surface R2 forms, for example, a concave surface of an inner surface progressive multifocal lens. Even if it is formed in a complicated surface shape, it can be uniformly polished following the shape of the finished lens forming surface R2. Thereby, the mirror surface finishing process is performed on the finished lens forming surface R2 of the semi-finished mold 100, and the lens forming surface R is formed. In this mirror finishing step S206, a final optical surface having a surface roughness of less than 100 nm is formed.
In addition, although the method using the copying polishing tool 500 was illustrated in the mirror finishing step S206, it is not limited to this. For example, using a numerical control polishing apparatus, relative positioning of the polisher head and the finish lens forming surface R2 is performed based on the numerical control processing data, and the polisher head is aligned in the normal direction at the processing point of the finish lens forming surface R2. For example, a method may be employed in which an arbitrary part of the surface is made to coincide and the polisher head is strongly pressed from this normal direction to perform polishing.

  Thereafter, a deblocking step S207 is performed in which the block jig 120 is removed from the mold setting part from the shape creation device, and the first mold 100A is removed from the block jig 120 and the low melting point alloy 110 that are no longer needed. Thereby, the first mold 100A is formed.

  Then, after the deblocking step S207, a cleaning step S208 is performed to clean the first mold 100A and remove attached dirt and the like.

[Mold assembly process]
And in the manufacturing method of the plastic lens of this Embodiment, mold assembly process S102 is implemented after mold formation process S101. In this mold assembly process S102, the lens mold 300 is assembled by combining the first mold 100A molded in the mold molding process S101 and the second mold 200 made of glass. The second mold 200 is formed by pouring molten glass into a mold, for example, and has a concave lens forming surface R3 that forms the convex surface side of the inner surface progressive multifocal lens. In the present embodiment, the second mold 200 uses a preformed glass mold. However, as with the first mold, for example, a second mold 200 made of a thermoplastic resin molded in the molding process S101 is used. Two molds 200 may be used.

  In this mold assembling step S102, as shown in FIG. 10, the first mold 100A and the second mold 200 are arranged and held with the lens forming surface R and the lens forming surface R3 facing each other and spaced apart by a predetermined distance. To do. Next, the adhesive tape 310 is wound over the peripheral portions of the first mold 100 </ b> A and the second mold 200. Thereby, the cavity 320 enclosed by the lens formation surfaces R and R3 and the adhesive tape 310 is formed, and the lens molding mold 300 can be assembled.

The adhesive tape 310 has a structure in which an adhesive layer is formed on a tape base material. The tape base material is polyolefin such as polyethylene and polypropylene, polyvinyl chloride,
Polyvinyl halides such as polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate, polyesters such as polyethylene naphthalate, polyamides, polyimides, polycarbonates, and the like are used. As the pressure-sensitive adhesive, acrylic, rubber, silicone or the like is used. A pressure-sensitive adhesive that does not dissolve in the resin composition or inhibits polymerization is selected.
The width of the adhesive tape 310 is not limited as long as the gaps can be sealed by holding both side surfaces of the first mold 100A and the second mold 200, and may be wide enough to protrude from these.

[Lens molding process]
Next, a lens molding step S103 for manufacturing a plastic lens is performed using the lens molding mold 300 assembled in the mold assembly step S102. The lens molding step S103 includes a raw material resin injection step, a curing step, and a release step.

In the raw resin injection process, the plastic lens raw resin is injected into the cavity 320 of the lens molding mold 300.
Here, examples of the raw material resin for the plastic lens include a photocurable resin composition that is polymerized and cured by light such as ultraviolet rays, and a thermosetting resin composition that is polymerized and cured by heat. The photocurable resin composition contains a photocurable monomer and a photopolymerization initiator, and the thermosetting resin composition contains a thermosetting monomer and a thermopolymerization initiator. is there. Examples of such raw materials include a resin composition containing an allyl monomer, a resin composition containing a methacrylate monomer, a resin composition containing a thiourethane monomer, and a thioepoxy monomer. A resin composition is mentioned.

  In this raw material resin injection step, for example, a small opening to the cavity 320 is formed in a part of the adhesive tape 310 of the lens molding mold 300, and this opening is adjusted in advance through a thin injection tube such as an injection needle. The curable resin composition is poured into the cavity 320. Thereafter, the adhesive tape 310 is again attached to the opening, and the cavity 320 is sealed. Moreover, you may take the method of apply | coating an adhesive agent to an opening part and sealing an opening part.

In the curing step, the plastic lens raw resin injected into the cavity 320 is cured. For example, when an ultraviolet curable resin composition is used, the ultraviolet curable resin composition in the cavity 320 is irradiated with ultraviolet rays through a mold.
A thermosetting resin can also be used suitably. In this case, no ultraviolet irradiation equipment is required, and the thermosetting resin in the cavity 320 is polymerized by heating.

  After the material resin in the cavity 320 is sufficiently cured and molded, a mold release step is performed as shown in FIG. For example, the first mold 100A and the second mold 200, and the first mold that is bonded to the cured resin layer (plastic lens) 400 by applying a force so that a wedge is accurately driven between the cured resins. 100A and the second mold 200 are detached. During this mold release process, if heated locally, such as by applying warm air to the surface layer of the first mold 100A and the second mold 200 and the cured resin layer (plastic lens) 400, the force applied to the wedge is reduced. Can be made.

  In addition, an annealing process for performing an annealing process or a thin film forming process for performing a thin film forming process may be provided on the plastic lens 400 after release.

  The annealing process is a process aimed at reducing polymerization strain. Polymerization distortion can be reduced by performing a heat treatment for about 30 minutes to 2 hours in a temperature atmosphere slightly lower than the glass transition point of the cured resin, preferably in a temperature atmosphere lower by 2 to 3 ° C. than the glass transition point. .

  In the thin film forming process, after the above-described annealing process, a scratch-preventing hard coat layer and an antireflection film for antireflection are laminated on both sides of the plastic lens 400.

  The plastic lens 400 is manufactured through the above steps.

[Regeneration process]
In the plastic lens manufacturing method of the present invention, the regeneration step S104 is performed after the lens molding step S103. As shown in FIG. 3, the regeneration step S104 includes a thermoplastic resin recovery step S301, a cleaning step S302, a pulverizing step S303, a substrate forming step S304, a semi-finished mold processing step S305, and the like. Yes.

  In the regeneration step S104, first, a thermoplastic resin recovery step S301 is performed. In this thermoplastic resin recovery step S301, the first mold 100A formed of a thermoplastic resin and / or cutting powder generated when the first mold 100A is formed is recovered. Specifically, the cutting of the semifinished mold 100 that occurs in the first mold 100A after the plastic lens 400 is released in the releasing step of the lens forming step S103 and / or the shape creation step S210 in the mold forming step S101. Collect the flour. In addition, in this Embodiment, although the 2nd mold 200 was manufactured with glass, when the 2nd mold 200 is shape | molded, for example with the thermoplastic resin, the 2nd mold 200 is also collect | recovered.

  In the cleaning step S302, the recovered thermoplastic resin composition is cleaned.

  Thereafter, as shown in FIG. 12, a crushing step S303 is performed. That is, among the thermoplastic resin composition cleaned in the cleaning step S302, the first mold 100A is pulverized by a pulverizer so as to be put into a hopper of an injection molding machine.

  Then, the substrate forming step S304 is performed, and the first mold 100A crushed in the pulverizing step S303, the cutting powder of the thermoplastic resin, and the abrasive powder are melted, and then injected into the mold at a predetermined injection pressure. The thermoplastic resin blank 100B or the semifinished mold 100 is injection molded.

[Operational effects of the plastic lens manufacturing method in the present embodiment]
As described above, in the plastic lens manufacturing method of the above-described embodiment, in the molding step S101, the first mold having the lens forming surface R by cutting and polishing the semi-finished mold 100 formed of the thermoplastic resin. 100A is formed. In the mold assembling step S102, the first mold 100A and the glass-made second mold 200 are opposed to each other through the cavity 320, and the peripheral edges of the first mold 100A and the second mold 200 are connected to form a lens molding mold. Assemble 300. After the mold assembling step S102, in the lens molding step S103, a plastic lens material resin is injected into the lens molding mold 300 and cured to manufacture a plastic lens. Thereafter, in the regeneration step S104, the first mold 100A after the plastic lens 400 is manufactured in the lens molding step S103 and / or the semi-finished mold cutting powder generated in the mold molding step S101 are recovered and recovered. The semi-finished mold 100 is formed again by melting the thermoplastic resin composition.
For this reason, since the plastic lens 400 formed of the thermosetting resin is not cut and polished, generation of cutting waste of the thermosetting resin can be avoided and adverse effects on the environment can be eliminated. Further, since the manufactured plastic lens 400 is not cut, the plastic lens 400 can be manufactured using only a minimum amount of raw material resin, and the manufacturing cost in manufacturing the plastic lens 400 can be reduced.

Moreover, the semifinished mold 100 is formed of a thermoplastic resin containing at least one of an inorganic fibrous reinforcing material and an inorganic particulate filler.
For this reason, thermal deformation of the semifinished mold 100 can be satisfactorily prevented by these inorganic fibrous reinforcing materials and inorganic particulate fillers. Therefore, in the molding process, it is possible to prevent thermal deformation during cutting of the lens forming surfaces R, R1, and R2 of the semifinished mold 100, so that the first mold 100A having the lens forming surface R with high accuracy can be generated. it can. Therefore, a high-precision progressive multifocal lens can be manufactured by manufacturing the plastic lens 400 using the lens molding mold 300 using the first mold 100A.

Further, in the molding step S101, the closest approximation to the first mold 100A corresponding to the lens shape of the plastic lens 400 to be manufactured based on numerical control processing data from a plurality of types of semi-finished molds that are generated and stocked in advance. The semi-finished mold 100 having the shape as described above is selected.
For this reason, the cutting amount of the semifinished mold 100 in the molding step S101 can be further reduced, and the working time required for cutting can be shortened. Therefore, it is possible to improve the work efficiency of each work in the molding step S101, and it is possible to manufacture the lens efficiently. Therefore, the cycle from the order of the plastic lens 400 to the manufacturing and ordering can be further accelerated.

  In the molding process, an aspherical lens forming surface R corresponding to the inner surface progressive multifocal lens is created based on the numerical control processing data. That is, a plastic lens 400 having a complicated surface shape such as a progressive multifocal lens can be manufactured.

  In the molding step S101, the block jig 120 is attached to the semifinished mold 100, and the block jig 120 is attached to the mold setting part of the shape creation apparatus. Thereby, attachment to the shape creation apparatus of the semifinished mold 100 becomes easy, and work efficiency can be improved. Further, since the semi-finished mold 100 can be reliably fixed to the mold installation part of the numerical control processing machine by the block jig 120, the cutting and polishing work of the semi-finished mold 100 in the shape creation step S210 can be performed with high accuracy.

  Further, in the mirror finishing step S206, the rubber sheet 520 formed in a hemispherical shape having flexibility is installed in a state of closing the opening of the tool casing, and the sealing between the tool casing 510 and the rubber sheet 520 is performed. For example, a copying polishing tool 500 in which, for example, pressurized gas or liquid is press-fitted into the space is used. For this reason, the finish lens forming surface R2 of the semifinished mold 100 is pressed against the rubber sheet 520, and the copying polishing tool 500 and the semifinished mold 100 are swung and rotated with each other, whereby the rubber sheet 520 is finished with the finished lens forming surface R2. Can be uniformly polished by following the shape of the finished lens forming surface R2. Therefore, even if the lens forming surface R is formed in a complicated surface shape that forms, for example, a concave surface of an inner surface progressive multifocal lens, mirror finishing can be easily performed.

[Other embodiments]
The present invention has been described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the scope of the present invention. Is possible.

For example, in the above embodiment, the outer diameter machining step (outer periphery shaping step) S202 is first performed in the shape creation step S210. For example, the outer diameter machining step (outer circumference shaping step) S202 is performed before and after the finish cutting step S204. You may implement. Further, when the outer diameter of the semifinished mold substantially matches the outer diameter of the plastic lens to be manufactured or when it substantially matches the diameter of the second mold, the outer diameter machining step (outer periphery shaping step) S202 is not performed. It is good also as a manufacturing method.

  Moreover, although the mirror surface finishing process S206 was implemented after the shape creation process S210, and the manufacturing method which mirror-finishes the lens formation surface R of the semifinished mold 100 was illustrated, it is not limited to this. For example, in the lens molding step S103, after the plastic lens is released, the surface of the plastic lens may be mirror-finished. In this case, the mirror-finishing step S206 of the semifinished mold 100 can be omitted.

  Further, in the mold forming step S101, the configuration in which the semi-finished mold 100 and the block jig 120 are detachably attached by the low melting point alloy in the blocking step S201 is shown. As described above, the block jig 120 is bonded, for example, It may be attached to the semi-finished mold with an agent, a fastener, wax, or the like, or a block jig 120 and a semi-finished mold 100 integrally formed with a thermoplastic resin may be used. By using the semifinished mold 100 integrated with such a block jig 120, the blocking step S201 and the deblocking step S207 can be omitted, and the first mold 100A can be generated more efficiently. As a result, the plastic lens 400 can also be manufactured more efficiently.

  In the above embodiment, it is preferable to use the copying polishing tool 500 as described above in order to form the lens forming surface R that forms the concave surface of the inner surface progressive multifocal lens. Thus, for example, a method of polishing with a numerical control polishing apparatus based on numerical control machining data may be used. In addition, it is also possible to adopt a conventional polishing method using a processing dish for polishing a mold for a concave surface of a single focus lens or a mold for forming a concave surface of a lens having a progressive surface on the convex surface side. .

  Further, in the above method, an example in which a predetermined semi-finished mold 100 is selected from a plurality of types of semi-finished molds 100 and the first mold 100A is generated by cutting and polishing the semi-finished mold 100 has been shown. Not exclusively. For example, in the molding process, a method of forming the first mold 100A by directly cutting and polishing a blank made of a thermoplastic resin as shown in FIG. 13 may be adopted. Even in this case, the cutting powder and the used first mold 100A can be collected and recycled again, and the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the method of manufacturing the inner surface progressive multifocal lens having the aspherical shape is exemplified. However, the method can be applied to a method of manufacturing a plastic lens having a spherical lens surface, for example.

Furthermore, as described above, the method of manufacturing the first mold 100A from the semi-finished mold 100 of the thermoplastic resin has been shown. However, the second mold 200 and both the first mold 100A and the second mold 200 are thermosetting. A method of generating from a resin semi-finished mold 100 may be adopted.
And although the example which forms the semifinished mold 100 by injection molding was shown in the said embodiment, it is not restricted to this. For example, the semifinished mold 100 may be manufactured by forming a substantially disc-shaped thermoplastic blank 100B as shown in FIG. 13 in the base material forming step S304 and cutting the thermoplastic blank 100B. In this case, the thermoplastic blank 100B is mounted on, for example, a semi-finished mold molding apparatus (not shown), and a lens forming surface having a spherical shape with a predetermined diameter is formed by performing a cutting process, thereby forming the semi-finished mold 100. . At this time, the cutting powder generated by cutting the thermoplastic blank 100B is recovered and can be used again in the regeneration step S104.

Although the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

  The following examples further illustrate the invention, but the invention is not limited thereto.

[Example 1]
The plastic lens 400 was manufactured by the plastic lens manufacturing method described above.

Mold forming step: A semi-finished mold 100 having a thermoplastic resin as a base material is aspherically processed into a convex shape by a shape creation device, and polished using a copying polishing tool 500 to obtain a first mold 100A that can obtain a final optical surface. Generated.
Mold assembly process: As the second mold 200, a glass mold having a spherical surface so that the lens forming surface R3 has a curvature radius of 167.5 mm was used. The first mold 100A and the second mold 200 formed by this mold forming step are arranged to face each other at an interval of a center thickness of 1.7 mm, and the outer peripheral edge of each mold 100A, 200 is wound with an adhesive tape to form the lens molding mold 300. Assembled.
Lens molding process: A plastic lens raw material resin was filled in the cavity 320 of the lens molding mold 300 assembled in the mold assembly process, and the temperature was raised in an atmospheric polymerization furnace for 15 hours. After the polymerization and curing, a mold release step was performed to obtain an inner surface progressive plastic lens having a refractive index of 1.67, S power of 0.00D, C power of 0.00D, and addition power of 0.5D.

Reproduction process: The cutting powder generated in the shape creation process of the mold forming process and the first mold 100A made of the thermoplastic resin used in the lens forming process are collected and passed through a washing process, a pulverizing process, and a substrate forming process. A semi-finished mold 100 was produced again. In each step, loss occurred and the regeneration rate was about 90%.
[Comparative example]
A spherical glass mold having a curvature radius of 167.5 mm on the convex surface side and a spherical glass mold having a curvature radius of 120.0 mm on the concave surface are opposed to each other so that the center thickness is 5.8 mm, and the outer peripheral edge is covered with an adhesive tape. The lens mold was produced by coupling. The lens molding mold was filled with a plastic lens raw material resin, heated in an atmospheric polymerization furnace for 25 hours, and subjected to a mold release step after polymerization and curing to obtain a semi-finished lens. The concave surface of this semi-finished lens is cut by a shape creation device, and an inner surface progressive plastic lens having a center thickness of 1.7 mm, a refractive index of 1.67, S power of 0.00D, C power of 0.00D, and addition power of 0.5D is obtained. Obtained.

〔result〕
As shown in Table 1, the amount of the raw material resin used for the plastic lens in the examples was 12 g, whereas the amount of the raw material resin used in the comparative example was 47 g. In the example,
The amount of plastic lens discarded was 0 g, while that of the comparative example was 35 g. Furthermore, while the polymerization lens heating time of the plastic lens in the example is 15 hours, in the comparative example, it took 25 hours to polymerize the plastic lens. From the above results, it can be seen that in the examples, the raw material resin of the plastic lens is greatly reduced and there is no amount of waste. It can also be seen that the polymerization curing time of the plastic lens can be shortened, and the working efficiency is improved.

  The present invention can be used in a manufacturing method for manufacturing a plastic lens used for glasses or the like.

The flowchart of the manufacturing method of the plastic lens which concerns on this Embodiment. The flowchart of the molding process in the manufacturing method of a plastic lens. It is a flowchart of the reproduction | regeneration process in the manufacturing method of a plastic lens. The figure which shows the outline of the semifinished mold in the blocking process of a molding process. The figure which shows the outline of the semifinished mold in the outer-diameter process (outer periphery shaping process) of a mold formation process. The figure which shows the outline of the semifinished mold in the approximate process rough cutting process of a mold formation process. The figure which shows the outline of the semifinished mold in the finish cutting process S204 of a mold formation process. The figure which shows the outline of the semifinished mold in the mirror surface finishing process S206 of a molding process. The figure which shows the outline of the semifinished mold in deblocking process S207 of a molding process. The figure which shows the outline of the lens shaping | molding mold assembled at the mold assembly process. The figure which shows the outline of the mold-released plastic lens and lens molding mold in the mold release process of a lens shaping | molding process. The figure which shows the outline of the grinding | pulverization process of a reproduction | regeneration process. The figure which shows the outline of the thermoplastic resin blank re-blanked in the base material formation process of a reproduction | regeneration process. The figure which shows the outline of the thermoplastic resin blank by which the semi-finished mold shape was re-blank in the base material formation process of a reproduction | regeneration process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Semi-finished mold as a structure, 100A ... 1st mold, 120 ... Block jig as a structure support part, 200 ... Second mold, 300 ... Lens molding mold as a molding mold, 320 ... Cavity, 400 ... plastic lens,
R ... lens forming surface, S101 ... mold forming step, S102 ... mold assembling step, S103 ... lens forming step, S104 ... regenerating step

Claims (5)

A plastic lens manufacturing method for manufacturing a plastic lens with a molding mold formed by opposing a first mold and a second mold and connecting outer peripheral edges of the first and second molds,
A mold that cuts and polishes a structure formed of a thermoplastic resin to form a lens forming surface corresponding to the surface shape of the plastic lens in at least one of the first mold and the second mold. Molding process;
A mold assembly step of assembling the molding mold by opposing the first mold and the second mold and connecting outer peripheral edges of the first mold and the second mold;
A lens molding step for injecting a plastic lens raw resin into the cavity of the molding mold and polymerizing and curing to form a plastic lens,
A method for producing a plastic lens, comprising: It is a manufacturing method of the plastic lens of Claim 1, Comprising:
The structure is formed of a thermoplastic resin in which a fibrous inorganic material or inorganic particles are mixed. It is a manufacturing method of the plastic lens of Claim 1 or Claim 2, Comprising:
In the molding step, the structure is cut and polished to form the lens forming surface having an aspherical shape. A method for producing a plastic lens according to any one of claims 1 to 3,
The structure includes a structure support section that supports the structure on a surface opposite to a surface on which the lens forming surface is formed, and is attachable to and detachable from a processing apparatus that cuts and polishes the structure. A method of manufacturing a plastic lens. It is a manufacturing method of the plastic lens of Claim 4, Comprising:
The method of manufacturing a plastic lens, wherein the structure support portion is integrally formed with the structure.

Images