JP2016035597A - Method for manufacturing polarizing plastic lens for spectacle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a high-quality polarizing plastic lens for spectacles without depending on molding accuracy of a polarizing film while ensuring flexibility in mold assembling.SOLUTION: The method for manufacturing a polarizing plastic lens for spectacles includes: a step of disposing a plastic member 20 made of a UV-curable resin or a thermosetting resin to rise on at least one of a peripheral part on an inner surface of a first lens mold 16 and a peripheral part of a polarizing film 14; and a step of bringing the plastic member 20 into contact with the inner surface of the first lens mold 16 and with the polarizing film 14 and solidifying the plastic member 20 by irradiation with UV rays or by heating while leaving a given clearance between the inner surface of the first lens mold 16 and the polarizing film 14, so as to fix the polarizing film 14 to the inner surface of the first lens mold 16.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing a polarizing plastic lens for spectacles.

  In general, when a plastic lens is manufactured by a casting method, a ring-shaped gasket (jig main body) serving as a mold frame and a pair of mold members fitted to both end openings of the gasket are used. . A monomer injection port is formed through the side wall portion of the gasket, and a monomer used as a lens material is filled and injected into the gasket in which the mold members are fitted through the injection port. When the monomer is solidified in the gasket, the fitting state of the two mold members is released, and a plastic lens molded to a predetermined thickness is taken out from the gasket.

  Thus, in the past, when manufacturing a plastic lens, a gasket having a monomer injection port is used as a lens manufacturing jig, but in practice, there are many types depending on the type of plastic lens to be manufactured. Various gaskets are used properly. For example, recently, the demand for products of plastic lenses (hereinafter referred to as “functional lenses”) in which a functional film such as a polarizing film is embedded in a lens thick wall is increasing. When manufacturing, a gasket as described in Patent Document 1 is used.

  That is, in the gasket described in Patent Document 1, a support convex portion for setting and supporting the functional film is formed on the inner surface of the side wall portion over the entire circumference, and on the top surface of the support convex portion. An insertion groove into which the peripheral edge of the functional film is inserted and supported is also formed over the entire circumference. Therefore, when manufacturing the functional lens using this gasket, first, the peripheral portion of the functional film is inserted and supported in the insertion groove of the support convex portion, and the functional film is set in the gasket. Then, after a pair of front and rear mold members are fitted into the opening portions at both ends of the gasket, the monomer is injected into the gasket from the monomer injection port. Then, a monomer is filled in each void in the gasket divided into two front and rear by the functional film, and the monomer in each void is solidified in a state of sandwiching the functional film. As a result, a functional lens in which a functional film is embedded in the lens thick wall is molded.

  Patent Document 2 is an example of a method for manufacturing a polarizing plastic lens. Patent Document 2 is a technology related to a polarizing plastic lens for spectacles, in which a polarizing film is held in a mold, a monomer (polymerization raw material) prepared in a cavity in the mold is filled, and after heat curing, release is performed. It is common to manufacture so that it may make it. By such a manufacturing method, a polarizing plastic lens in which a polarizing film as in Patent Document 2 is sandwiched between front and back surfaces by a lens can be obtained.

JP 2001-318044 A Japanese Patent Laid-Open No. 2005-99687

  However, when a functional film is held using a gasket, the holding position is determined by the design and manufacturing accuracy of the gasket regardless of the shape difference of each functional film. ) Varies, and there is a problem that there is a limit to thinning the functional lens.

  In addition, it was necessary to have a gasket for each refractive index and base curve, and there was no flexibility in adapting to design changes and new materials.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A method for manufacturing a polarizing plastic lens for spectacles in which a uniaxially stretched polarizing film is held inside a plastic, wherein the first surface for forming either the front or back surface of the polarizing plastic lens for spectacles is formed. Providing a plastic member on at least one of the peripheral edge of the inner surface of the lens mold and the peripheral edge of the polarizing film; and providing the member with the inner surface of the first lens mold and the polarizing film. And the member is solidified with a predetermined gap between the inner surface of the first lens mold and the polarizing film, and the polarizing film is used as the first lens mold. A fixing step; an inner surface of a second lens mold for forming either the front or back surface of the polarizing plastic lens for spectacles; The first and second lens molds and the first and second lens molds are disposed so as to be spaced apart from each other by a predetermined distance and surround the first and second lens molds and the first and second lens molds. Forming a cavity partitioned from the outside on both sides of the polarizing film by a spacing member for holding the lens mold, filling a plastic lens monomer in the cavity, and And a step of releasing the first and second lens molds after the monomer has been cured.

  According to this, the inner surface of the first lens mold and the polarizing film are brought into contact with the member, and the member is solidified with a predetermined gap between the inner surface of the first lens mold and the polarizing film. By fixing the polarizing film to the inner surface of the first lens mold, the polarizing film can be held in the mold without using a gasket. Flexibility can be ensured with respect to these requirements that cannot be easily switched by gasket polymerization, such as changing the thickness and changing the shape of the polarizing film.

  Application Example 2 In the method of manufacturing a polarizing plastic lens for spectacles, the predetermined interval is a distance at a center base point between the polarizing film and the first and second lens molds. A manufacturing method of a polarizing plastic lens for spectacles.

  According to this, it becomes possible to always make the position of the center of the polarizing film with respect to the mold center constant by assembling at the center base point of the polarizing film and the first and second lens molds every time it is assembled. In other words, it is no longer necessary to have more room in the center than necessary, taking into account the molding accuracy of the polarizing film, leading to a thinner plastic plastic lens for spectacles, and for high-quality glasses that do not depend on the molding accuracy of the polarizing film. A method of manufacturing a polarizing plastic lens can be provided.

  [Application Example 3] A method for manufacturing a polarizing plastic lens for spectacles, wherein the spacing member is an adhesive tape.

  According to this, shrinkage of the monomer injected into the cavity during polymerization curing occurs, but the adhesive tape shrinks following the shrinkage of the monomer to prevent the generation of voids in the cavity, and the lens chip ( Can be eliminated. That is, there is no lens to be discarded due to lens chipping. As a result, the production yield is improved, and effects such as reduction of the amount of monomer used and reduction of exhaust gas generated at the time of disposal due to combustion treatment can be obtained, and the environmental load can be greatly reduced.

  Application Example 4 A method for manufacturing a polarizing plastic lens for spectacles, wherein the member is an ultraviolet curable resin.

  According to this, since curing by ultraviolet rays is several seconds to several tens of seconds, the influence on the manufacturing cycle can be suppressed.

The figure which shows the manufacturing process of the plastic lens which concerns on this embodiment. The figure which shows the manufacturing method of the polarizing film which concerns on this embodiment. The figure which shows the adhesive agent on the 1st mold which concerns on this embodiment. The figure which shows the method of forming an adhesive agent in the 1st mold which concerns on this embodiment. The figure which shows the discharge apparatus for apply | coating the adhesive agent which concerns on this embodiment. The figure which shows the manufacturing method of the plastic lens which concerns on this embodiment. The figure which shows the manufacturing method of the plastic lens which concerns on this embodiment.

  Hereinafter, a method of manufacturing a polarizing plastic lens for spectacles (hereinafter referred to as a plastic lens) according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a manufacturing process of a plastic lens according to the present embodiment. The manufacturing method of this embodiment is roughly divided into five steps as shown in FIG. Hereafter, this process is demonstrated in order.

(Adjustment of polarizing film)
This process becomes a manufacturing process of the polarizing film used for the method of this embodiment.
FIG. 2 is a diagram showing a method for manufacturing a polarizing film according to this embodiment. As shown in FIG. 2A, two spherical surfaces of the same shape are formed by pressing a flat sheet 10 obtained by cutting a uniaxially stretched PVA (polyvinyl alcohol) film into a rectangular shape by a known pressing means. A curved surface 12 is formed. The curve of the curved surface 12 is set to be approximately the same as the base curve of the plastic lens 2 to be manufactured (see FIG. 7B). The polarizing film 14 may be formed with the same curvature as the base curve of the plastic lens 2. In the present embodiment, the polarizing film 14 is obtained by cutting along the broken line K in the figure while leaving the portion of the sheet body 10 around each curved surface 12.

  The outer diameter of the polarizing film 14 is smaller than the outer diameters of the first mold (first lens mold) 16 and the second mold (second lens mold) 18 as shown in FIG. . For example, the diameter of the polarizing film 14 is about 2 mm smaller than the diameter of the first mold 16. Thereby, at the time of injection | pouring of a plastic raw material composition (monomer), a raw material will come to the both sides of the polarizing film 14, and the injection | pouring of the monomer in a cavity can be performed smoothly.

FIG. 3 is a diagram showing an adhesive on the first mold 16 according to the present embodiment.
Next, an adhesive (member) 20 is applied to the back surface 16 a of the first mold 16. A plurality of adhesives 20 are applied to the edge of the back surface 16 a of the first mold 16. For example, it is applied to three or four places. In this embodiment, four places are applied on the borders in four orthogonal directions. For example, the ultraviolet curable adhesive 20 is applied to the outer periphery of the polarizing film 14 with a dispenser.

  The first mold 16 is a mold for forming either the front or back surface of the plastic lens 2. In the present embodiment, the first mold 16 is a mold for forming the surface of the plastic lens 2. The first mold 16 is a glass circular plate. The back surface 16a of the first mold 16 is a curved surface for molding the surface (object side) of the plastic lens to be molded. The first mold 16 is not particularly limited as long as it is a material that transmits ultraviolet rays. In the present embodiment, crown glass is used for the first mold 16. In addition, since a light-transmitting organic substance (for example, resin) is deteriorated by irradiation with ultraviolet rays, it is not suitable for a mold for molding a large amount of plastic lenses. However, using the advantage of low cost, for example, it may be used for a mold for molding a small amount of sample product.

  The adhesive 20 used in the present embodiment is an ultraviolet curable resin material. As is well known, the ultraviolet curable resin material has a characteristic of scientifically changing from a liquid to a solid in response to light energy of ultraviolet rays. This ultraviolet curable resin material is made of a synthetic resin containing a prepolymer, a monomer, a photopolymerization initiator and additives. In addition, although the kind in particular is not limited as an ultraviolet curable resin material used for this embodiment, A suitable thing is selected according to the specification of a monomer.

  FIG. 4 is a diagram illustrating a method for forming the adhesive 20 on the first mold 16 according to the present embodiment, and FIG. 5 is a diagram illustrating a discharge device for applying the adhesive 20 according to the present embodiment. It is. Based on FIG.4 and FIG.5, the outline of the discharge apparatus 22 for forming the adhesive agent 20 is demonstrated. The discharge device 22 includes a main body 24 in which a motor device (not shown) is incorporated, a rotary shaft 26 protruding upward from the main body 24, and a turntable 28 disposed on the upper end of the rotary shaft 26. On the upper surface of the turntable 28, a flexible ring-shaped fixing pad 30 that is in contact with the vicinity of the periphery of the surface 16b of the first mold 16 is set. The reason why the ring-shaped fixing pad 30 is used is to prevent the fixing means of the first mold 16 from contacting the light transmitting surface of the surface 16b as much as possible. A syringe 36 is attached to a rod 32 extending upward from the main body 24 via a slider 34. The syringe 36 discharges a viscous ultraviolet curable epoxy resin P from the needle 38 at the tip at a constant discharge amount by pneumatic control by a dispenser device in the main body 24 (not shown).

  Actually, a plurality of turntables 28 and syringes 36 in the discharge device 22 are prepared, and many processes can be performed simultaneously.

  Next, a method for applying the adhesive 20 using such a discharge device 22 will be briefly described. An ultraviolet curable adhesive 20 is applied to the outer periphery of the first mold 16 with a dispenser. After centering the first mold 16, an adhesive is applied to the border. As shown in FIGS. 4 and 5, the first mold 16 is placed on the fixed pad 30 of the turntable 28, the position of the syringe 36 is appropriately adjusted, and the needle 38 is placed on the back surface 16 a of the first mold 16. And it arrange | positions above the position close | similar to the periphery of the back surface 16a. Then, the ejection device 22 is driven. That is, the turntable 28 is rotated to rotate the first mold 16 in the circumferential direction, and the dispenser device is driven to discharge the ultraviolet curable epoxy resin P from the tip of the needle 38 toward the periphery of the back surface 16a in the circumferential direction. The adhesive 20 is applied along. The height of the adhesive 20 is formed at the same height over the entire circumference.

(Mold assembly)
6 and 7 are diagrams showing a method for manufacturing the plastic lens 2 according to the present embodiment. First, the center height of the first mold 16 to be assembled and the center height of the held polarizing film 14 are measured. In measuring the height of the polarizing film 14, since the polarizing film 14 is soft, the apex height of the polarizing film 14 is measured using a non-contact type sensor (for example, Keyence CCD transmissive digital laser sensor IG series).
When measuring the height of the first mold 16, the first mold 16 is rigid, so that the apex height of the mold can be obtained with a device having a contact type measurement probe (for example, Nikon Digimicro MF series or Mitutoyo Digimatic Indicator 543 series). Measure.
Next, as shown in FIG. 6A, the first mold 16 is placed on the polarizing film 14 from the front direction of the polarizing film 14. Alternatively, the polarizing film 14 held on the fixing base 51 is brought close to the first mold 16 held on the fixing pad 52.

  Next, based on the center height between the first mold 16 and the polarizing film 14, the adhesive 20 is brought into contact with the polarizing film 14 by bringing the first mold 16 and the polarizing film 14 close to an arbitrary distance. Thereafter, the first mold 16 and the polarizing film 14 are held at a predetermined interval, and then the adhesive 20 is irradiated with ultraviolet rays to maintain the distance between the first mold 16 and the polarizing film 14. Solidify. Although the time for irradiating the ultraviolet rays depends on the type of the selected adhesive 20, a short time (several seconds to several tens of seconds) is sufficient, so that the influence on the manufacturing cycle can be suppressed. For example, ultraviolet rays are irradiated at 500 mW for 15 seconds. In addition, when it is judged that the amount of ultraviolet irradiation is insufficient, it is also possible to continue to irradiate the formed adhesive 20 with ultraviolet rays as appropriate.

  Next, the second mold 18 is disposed so as to face the set center thickness. The second mold 18 is a glass circular plate. The front surface 18a of the second mold 18 is a curved surface for molding the back surface (eyeball side) of the plastic lens 2 to be molded. The first and second molds 16 and 18 are sandwiched between the polarizing film 14 from the front and back directions of the polarizing film 14.

  Next, as shown in FIG. 6B, the pair of first and second molds 16 and 18 are held at a necessary interval, and the two first and second molds 16 and 18 are held. The adhesive tape (space-retaining member) 46 having an adhesive layer on one side is wound around the side surface slightly more than one round. At this time, the first and second molds 16 and 18 are set on the fixed pad 52. The fixed pad 52 is rotationally driven by a rotating shaft 54 protruding from a motor device (not shown).

  The material of the adhesive tape 46 is not particularly limited. In view of ease of use and economy, it is preferable to use a plastic adhesive tape. For example, a base material made of polypropylene and a polyethylene terephthalate material are prepared by combining acrylic, natural rubber, and silicon materials as the adhesive. The adhesive tape 46 may be provided with an injection hole (not shown) for injecting the monomer.

  The state of the first and second molds 16 and 18 and the adhesive tape 46 assembled with the polarizing film 14 interposed therebetween is taken as a mother die 48.

(Monomer injection)
Next, as shown in FIG. 7 (A), the monomer prepared for the mother mold 48 assembled in this way is degassed under reduced pressure, and then this pair is used from the injection hole using an injector. The monomer is filled in the cavity 50 formed by the first and second molds 16 and 18 and the adhesive tape 46 so that no bubbles remain in the cavity 50.

(Heating / curing)
Thereafter, the mother mold 48 filled with the plastic raw material composition is put into a heating furnace and heated. Here, the heating temperature is preferably 0 to 150 ° C., more preferably 10 to 130 ° C., and the heating is preferably performed for 5 to 50 hours, more preferably 10 to 25 hours to perform polymerization. . For example, it hold | maintained at 30 degreeC for 7 hours, and heated up over 30 hours after that to 30-120 degreeC.

(Demolding)
When the heat treatment is completed, the monomer is solidified and a cured plastic raw material composition in which the polarizing film 14 is built in the matrix 48 is formed. The mother die 48 is taken out of the heating furnace, the adhesive tape 46 is peeled off, the first and second molds 16 and 18 and the cured plastic raw material composition are separated, and as shown in FIG. Is cut to obtain the plastic lens 2 as a finished product.

  According to this embodiment, the back surface 16a of the first mold 16 and the polarizing film 14 are brought into contact with the adhesive 20 so that a predetermined gap is provided between the back surface 16a of the first mold 16 and the polarizing film 14. In this state, the adhesive 20 is solidified, and the polarizing film 14 is fixed to the back surface 16a of the first mold 16, thereby changing the design of the first and second molds 16 and 18 and changing the thickness of the plastic lens 2. In addition, it is possible to ensure flexibility with respect to these requirements that cannot be easily switched by gasket polymerization, for example, corresponding to the shape change of the polarizing film 14.

  In addition, by assembling the polarizing film 14 and the first and second molds 16 and 18 at a predetermined interval each time assembling, the position of the center of the polarizing film 14 with respect to the centers of the first and second molds 16 and 18 is set. It becomes possible to always make it constant. In other words, since it is not necessary to allow more room for the central portion than necessary in consideration of the molding accuracy of the polarizing film, the plastic lens 2 can be made thinner and the high-quality plastic lens 2 that does not depend on the molding accuracy of the polarizing film 14. Can be provided.

  Further, the first mold 16, the polarizing film 14, and the second mold 18 are arranged in this order and are simply taped with the adhesive tape 46 to fill (enclose) the cavity 50 filled with the monomer in which the polarizing film 14 is disposed. As a result, the construction of the cavity for manufacturing the plastic lens 2 can be made much faster and easier than before, which contributes to the cost reduction as a whole.

  It should be noted that the present invention can be modified and embodied as follows. In the said embodiment, although the adhesive agent 20 was solidified by irradiating an ultraviolet-ray using photocuring resin, you may make it solidify by heating using a thermosetting resin.

  In the above-described embodiment, the adhesive 20 is formed by rotating the polarizing film 14 side. However, the configuration may be such that the syringe 36 moves to form the adhesive 20.

  The object to which the adhesive 20 is applied in the embodiment is not limited to the first mold 16 and may be applied to the polarizing film 14. Further, when the first mold 16 and the polarizing film 14 are brought close to each other, not only the polarizing film 14 is moved, but also the method of moving the first mold 16 and both the first mold 16 and the polarizing film 14. May be moved closer together.

  In the above embodiment, the polarizing film 14 curved in a spherical shape has been described as an example. However, the polarizing film 14 may be applied to a flat polarizing film 14. Moreover, the polarizing film 14 does not necessarily need to be comprised by the surrounding circular shape.

  The material of the polarizing film 14 of the said embodiment is not limited above. In the above embodiment, PVA is used, but other plastics such as polyethylene terephthalate can also be used. It is also possible to use a film in which both surfaces of a polarizing film such as PVA are sandwiched between triacetyl cellulose and polycarbonate, or a film in which triacetyl cellulose or polycarbonate is attached to one side of a polarizing film such as PVA.

  The configuration of the ejection device 22 of the above-described embodiment is an example, and it is free to appropriately change to means for applying the other adhesive 20 realized by other configurations.

  The method for holding the first and second molds 16 and 18 in the above embodiment illustrates the adhesive tape 46, but a gasket may be used as an application.

  DESCRIPTION OF SYMBOLS 2 ... Plastic lens (polarized plastic lens for spectacles) 10 ... Sheet body 12 ... Curved surface 14 ... Polarizing film 16 ... 1st mold (1st lens mold) 16a ... Back surface 16b ... Front surface 18 ... 2nd mold ( Second lens mold) 18a ... surface 20 ... adhesive (member) 22 ... discharge device 24 ... main body 26 ... rotary shaft 28 ... turntable 30 ... fixing pad 32 ... rod 34 ... slider 36 ... syringe 38 ... needle 46 ... Adhesive tape (space-holding member) 48 ... Mother mold 50 ... Cavity 51 ... Fixing base 52 ... Fixing pad 54 ... Rotating shaft.

Claims (3)

A method for producing a polarizing plastic lens for spectacles in which a uniaxially stretched polarizing film is held inside a plastic,
An ultraviolet curable resin or a thermosetting resin on at least one of the peripheral edge of the inner surface of the first lens mold and the peripheral edge of the polarizing film for forming either the front or back surface of the polarizing plastic lens for spectacles Providing a plastic member composed of
After the plastic member is brought into contact with the inner surface of the first lens mold and the polarizing film and held between the inner surface of the first lens mold and the polarizing film at a predetermined interval, Fixing the polarizing film to the first lens mold by solidifying the plastic member with ultraviolet irradiation or heating while maintaining the predetermined interval; and
The inner surface of the second lens mold for forming either the front or back surface of the polarizing plastic lens for spectacles and the polarizing film are disposed with a predetermined gap therebetween, and the first and first Two lens molds and an interval holding member which surrounds the first and second lens molds and holds the first and second lens molds are partitioned from the outside on both sides of the polarizing film. Forming a cavity,
Filling the cavity with a monomer for a plastic lens; and
Releasing the first and second lens molds after curing the monomer;
The manufacturing method of the polarizing plastic lens for spectacles characterized by including these. In the manufacturing method of the polarizing plastic lens for spectacles of Claim 1,
The predetermined distance between the inner surface of the first lens mold and the polarizing film is a distance between the center of the polarizing film and the center of the first lens mold. For manufacturing polarized plastic lenses for use in medical applications. In the manufacturing method of the polarizing plastic lens for spectacles of Claim 1 or 2,
The method for manufacturing a polarizing plastic lens for spectacles, wherein the spacing member is an adhesive tape.

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