JP2008137336A - Die for molding lens and method for producing plastic lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding die for a lens and a method for producing a plastic lens using the same, which is capable of preventing introduction of foreign materials of an adhesive tape into the molding die and of reducing generation of bubbles. <P>SOLUTION: The molding die for molding a plastic lens 1 comprises a cavity 5 formed by being equipped with a molding die 2 for molding one surface of a lens and a molding die 3 for molding the other surface of a lens, which are set forth oppositely at predetermined intervals, and an adhesive tape 4 at the outer peripheral sides of the two molding dies 2 and 3, wherein there is set forth a penetrating hole 2b for charging in a vertical direction of a molding surface 2a of the molding die 2, and this penetrating hole 2b for charging acts as an inlet for charging lens materials into the cavity 5 and also as an outlet for removing air in the cavity 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens mold used for molding a plastic lens by a casting polymerization method, and a method for producing a plastic lens using the same.

  When producing a plastic lens having excellent optical performance, a casting polymerization method is generally used. As the casting polymerization method, a molding die for molding one surface of the lens and a molding die for molding the other surface of the lens are arranged to face each other at a predetermined interval, and an adhesive tape is provided on the outer peripheral side surfaces of the two molding dies. A tape mold method in which a raw material composition is injected into a molding mold and polymerized and cured using a molding mold in which is wound is widely known.

As a method of injecting the raw material composition into the molding mold in the tape molding method, an overlap portion of the adhesive tape wound around the outer peripheral side surface is peeled off to form an opening portion, and an injection tube is inserted into the opening portion. A method that is performed by inserting or a method that is performed by piercing an injection tube or the like having a sharp tip into an adhesive tape wound around the outer peripheral side surface is used.
However, although the former injection method is used after the raw material composition is injected and the adhesive tape is again overlapped to seal the aperture, it has problems in terms of sealing performance and workability. In the latter injection method, there is a problem that a small piece of the adhesive tape or the like generated when the injection tube is pierced into the adhesive tape enters the molding mold to impair optical performance and appearance quality. In addition, the sealing method of an injection hole uses the method of sticking another adhesive tape, dripping a photocurable resin, and hardening | curing.

  In order to deal with such problems, after the compressed air heated by an air heater or the like is blown onto the adhesive tape through a metal nozzle, an injection port is provided, and then an injection tube is inserted from the injection port to inject the plastic raw material liquid. There has been proposed an injection method for performing (see, for example, Patent Document 1).

JP-A-9-85754

However, in the injection method according to Patent Document 1, although it is possible to reduce mixing of small pieces of the adhesive tape by heating and melting and providing an injection port in the adhesive tape, the base material piece of the adhesive tape blown off by compressed air And the problem that foreign materials such as adhesives enter. Moreover, the injection method of the raw material composition in the tape mold method has another problem that bubbles remain in the molding mold and the appearance quality and optical characteristics are impaired.
Therefore, the present invention has been made in view of such circumstances, and when molding a plastic lens, it prevents foreign matter from entering the adhesive tape into the cavity of the molding mold and prevents air bubbles from entering. It is an object of the present invention to provide a lens mold that can be used, and a plastic lens manufacturing method using the same.

  In order to solve the above-mentioned problems, a lens mold according to the present invention has a predetermined distance between a first mold for molding one surface of a lens and a second mold for molding the other surface of the lens. A mold for molding a plastic lens by injecting a lens raw material into a cavity formed by adhering an adhesive tape to the outer peripheral side surfaces of the first mold and the second mold A lens mold, wherein at least one of the first mold and the second mold has at least one aperture in a region other than the lens use region. It is characterized by.

  According to the present invention, the first mold for molding one surface of the lens and the second mold for molding the other surface of the lens are opposed to each other at a predetermined interval, and the first mold and In a mold for molding a plastic lens by injecting a lens raw material into a cavity formed by adhering an adhesive tape to the outer peripheral side surface of a second mold, the first mold and the second mold An injection port for injecting the lens raw material into the cavity by having at least one aperture in a region other than the lens use region of at least one of the lens molds, and It can be used as an exhaust port for exhausting air in the cavity. Therefore, it is not necessary to pierce the injection tube or the like into the adhesive tape attached to the outer peripheral side surfaces of the two lens molds, or to peel off the adhesive tape to form the opening portion. In addition to preventing entry of foreign substances such as tape base material pieces and adhesives, it is possible to prevent bubbles from remaining in the cavity, thereby preventing optical performance and appearance quality of the molded lens from being impaired.

In the lens mold according to the present invention, the area other than the lens use area is preferably in the vicinity of the peripheral edge of the lens mold.
According to this configuration, the opening provided in at least one of the first mold and the second mold is provided in an area other than the lens use area, and the area Is in the vicinity of the periphery of the lens mold, so that the lens use area of the molded lens is not narrowed.

In the lens mold according to the present invention, it is preferable that the opening portion is a through-hole penetrating in the thickness direction of the lens mold or a recess including a peripheral edge of the lens mold.
According to this configuration, the through-hole or the lens in which the opening provided in at least one of the first molding die and the second molding die penetrates in the thickness direction of the lens molding die. Due to the recess including the periphery of the molding die, it is possible to form an opening corresponding to the shape of the lens to be molded. Among these, in particular, in the case of the concave portion including the peripheral edge, the lens usage area of the molded lens can be used more widely. Further, the concave portion can be formed at the same time as the lens molding surface at the time of lens mold processing such as hot press or mold molding, so there is no need for secondary processing, which can contribute to cost reduction of the lens molding die. .

In the lens mold according to the present invention, it is preferable that at least one of the first mold and the second mold has one hole portion.
According to such a configuration, at least one of the first molding die and the second molding die has one aperture portion, so that the lens raw material is placed in the cavity. It can be used as an injection port for injection. At that time, by forming the size of the opening larger than the nozzle diameter of an injection nozzle or the like for injecting the lens raw material into the cavity, it can also serve as an exhaust port for exhausting the air in the cavity. it can. Thereby, it is possible to prevent bubbles from remaining in the cavity and impairing the appearance quality and optical characteristics of the molded lens. Further, since there is one opening, workability for sealing the opening is improved.

In the lens mold according to the present invention, it is preferable that at least one of the first mold and the second mold has the two opening portions.
According to such a configuration, by providing two apertures on the lens molding die surface of at least one of the first molding die and the second molding die, one of the apertures is placed in the cavity. The lens raw material can be used as an inlet and the other opening can be used as an exhaust port for discharging air from the cavity. Therefore, the air in the cavity can be efficiently exhausted, and it is possible to further prevent the appearance quality and optical characteristics of the molded lens from being deteriorated due to the bubbles remaining in the cavity. In addition, by using the two aperture portions as separate inlets and exhaust ports, the aperture portions are not enlarged, and the use of the molded lens can be reduced.

In the lens mold according to the present invention, it is preferable that the two opening portions are provided at positions substantially symmetrical with respect to the center of the surface of the lens mold.
According to such a configuration, the two opening portions provided in at least one of the first mold and the second mold are approximately the center of the surface of the lens mold. By being provided at a symmetrical position, one opening is used as an inlet for injecting lens raw material into the cavity, and the other one is used as an outlet for discharging air from the cavity. By using it, the air in the cavity can be exhausted more efficiently, and it is possible to further prevent the appearance quality and optical characteristics of the lens formed by bubbles remaining in the cavity from being impaired.

  In the method for producing a plastic lens of the present invention, a first mold for molding one surface of the lens and a second mold for molding the other surface of the lens are opposed to each other at a predetermined interval. And a plastic lens manufacturing method for molding a plastic lens by injecting a lens raw material into a cavity formed by adhering an adhesive tape to the outer peripheral side surface of the second mold and the second mold, A molding mold assembling process for assembling a molding mold for molding a plastic lens using such a lens molding die, and a lens raw material is injected into the cavity of the molding mold from the opening provided in the lens molding die. A raw material injection step, a sealing step for sealing the opening, and a polymerization hardening step for hardening the lens raw material injected into the cavity of the molding mold. Characterized by comprising in sequence.

  According to such a method of manufacturing a plastic lens, a molding mold assembling step for assembling a molding mold for molding a plastic lens using the lens molding die as described above, and a lens raw material from a hole portion in a cavity of the molding mold. The opening provided in the lens mold in the molding mold assembling step by providing in this order a raw material injection step for injecting, a sealing step for sealing the aperture, and a polymerization curing step for curing the lens raw material By injecting the lens raw material from the inside, the intrusion of foreign substances such as adhesive tape base material and adhesive into the molding mold is prevented, and the air in the cavity is discharged from the opening in the raw material injection process. It is possible to prevent bubbles from remaining on the surface. As a result, a plastic lens excellent in appearance quality and optical characteristics free from foreign matters and bubbles can be obtained.

  In the plastic lens manufacturing method according to the present invention, in the molding mold assembling step, at least one of the first molding die and the second molding die is provided with one opening portion. A molding mold is assembled using a lens molding die having the above, and in the raw material injection step, the molding mold is arranged so that a surface of the lens molding die provided with the opening portion is in a vertical direction, It is preferable to inject the lens raw material with the aperture portion on the upper side in the vertical direction.

  According to the plastic lens manufacturing method, in the molding mold assembling step, the lens molding die having one aperture portion in at least one of the first molding die and the second molding die is provided. The molding mold that is assembled using is arranged in the vertical direction in the raw material injecting step, and the aperture is made by injecting the lens raw material into the cavity from the aperture with the aperture being on the upper side in the vertical direction. Can also serve as an exhaust port for exhausting the air in the cavity. As a result, a plastic lens excellent in appearance quality and optical characteristics free from foreign matters and bubbles can be obtained.

  In the plastic lens manufacturing method according to the present invention, in the molding mold assembling step, at least one of the first molding die and the second molding die has two openings. The molding mold is assembled using a lens molding die having a portion provided at a substantially symmetrical position with respect to the center of the surface of the lens molding die, and the molding mold includes the two openings. The lens molding die provided with a portion is disposed so as to be inclined with respect to the vertical direction with the surface of the lens mold on the upper side, and one of the two opening portions is on the lower side in the vertical direction. It is preferable to inject the lens material.

  According to this method of manufacturing a plastic lens, in the molding mold assembling step, at least one of the first molding die and the second molding die is provided with two aperture portions formed as lens molding dies. A molding mold assembled using a lens mold provided at a substantially symmetrical position with respect to the center of the surface has an upper surface of the lens mold provided with two apertures in the raw material injection step. Inclined with respect to the vertical direction, by placing one of the two apertures downward and injecting the lens raw material into the cavity with the aperture as an injection port, It is possible to prevent air in the cavity from being forced out of the cavity through the opening located on the lower side and entraining bubbles in the lens material M to be injected. As a result, a plastic lens excellent in appearance quality and optical characteristics free from foreign matters and bubbles can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings shown below, the dimensions and ratios of the constituent elements are different from actual ones for convenience of explanation.

[First Embodiment]
A manufacturing method of a plastic lens (hereinafter referred to as a lens) in the present embodiment includes a molding mold assembling process for assembling a molding mold, a raw material injection process for injecting a lens raw material into a cavity of the molding mold, and a lens raw material. A sealing step for sealing the injection port used for injection, and a polymerization curing step for curing the lens raw material injected into the cavity.

First, a molding mold used for molding a lens will be described.
FIG. 1A is a schematic external view of a molding mold according to the first embodiment, FIG. 1B is a front view of the molding mold, and FIG. 1C is a cross-sectional view of the molding mold. is there. In addition, the mold for molding shown in FIGS. 1A to 1C shows a mode before injection of the lens raw material.

In FIG. 1, a molding mold 1 includes a first mold 2 for molding one surface of a lens (hereinafter referred to as a mold 2) and a second mold for molding the other surface of the lens. 3 (hereinafter referred to as a mold 3) and two lens molds (hereinafter also referred to as a mold), and an adhesive tape 4 wound around the outer peripheral side surfaces of the molds 2 and 3 It is configured.
In the molding mold 1, the two molding dies 2 and 3 are arranged opposite to each other at a predetermined interval, and the adhesive tape 4 is wound around the outer peripheral side a little more than one round, so that the molding die 2 and the molding die 3 are connected. At the same time, the gap between the mold 2 and the mold 3 is closed, and the cavity 5 is formed.

The mold 2 and the mold 3 are glass lens molds having a circular shape in plan view, and have substantially the same outer diameter.
The molding die 2 has, for example, a molding surface 2a as a lens surface for molding a convex surface, and an injection port as an opening that penetrates in the thickness direction of the molding die 2 in a region other than the lens use region of the molding surface 2a. 2b is provided. When the lens to be molded is a spectacle lens, the region other than the lens use region is a processing region that is rimmed to match the shape of the inner peripheral edge of the spectacle frame, for example, in the case of other various optical lenses And an area that is guided and held by a mirror body or a housing. Therefore, the inlet 2b is preferably as small as possible and provided near the periphery (outer periphery) of the mold, and more preferably in the range of about 7 mm to 8 mm from the outer periphery.

  The injection port 2 b is a hole through which an injection nozzle for injecting the lens material into the cavity 5 is passed, and is an exhaust port for discharging the air in the cavity 5 when the lens material is injected. It also has a function as an outlet from which the filled lens material overflows.

  Also, the inlet 2b has a size of, for example, a hole diameter of about 5 mm, and is formed by hot pressing or punching a die using a diamond drill or the like. The injection port 2b is at least larger than the outer diameter of the injection nozzle inserted into the injection port 2b, and the gap between the injection port 2b and the injection nozzle exhausts the air in the cavity 5 and further into the cavity 5. The size and shape are not limited as long as the filled lens material can overflow.

The mold 3 has a molding surface 3a as a lens surface for molding a concave surface, for example.
The injection port may be provided in the mold 3 instead of the mold 2. The molding surface 2a of the molding die 2 and the molding surface 3a of the molding die 3 are optical surfaces formed with shapes such as a spherical surface, a rotationally symmetric aspherical surface, a toric surface, a progressive surface, or a curved surface obtained by combining these. .

The pressure-sensitive adhesive tape 4 has, for example, a pressure-sensitive adhesive layer (not shown) having a thickness of about 30 μm on a tape-shaped tape substrate having a width of about 25 mm.
The tape base material has sufficient strength to hold the two molds 2 and 3, chemical resistance not affected by the liquid lens raw material M, and sufficient heat resistance against heating during polymerization and curing. Desirable materials include polyolefins such as polyethylene and polypropylene, or polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, and polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyamides, polyimides, Polycarbonates can be exemplified. Among these, polyethylene terephthalate can be preferably used from the viewpoints of strength and heat resistance.

Moreover, the thickness of a tape base material is 100 micrometers-220 micrometers, Preferably the range of 125 micrometers-200 micrometers is used preferably. When the thickness is 100 μm or less, the strength of the lens material cannot be withstood by the shrinkage of the lens raw material during polymerization and curing, and a number of partially wrinkled tape wrinkles may occur. When the thickness is 220 μm or more, the workability of winding around the side surfaces of the molds 2 and 3 is remarkably reduced, and leakage of the lens material injected into the cavity occurs from the overlap wound slightly more than one round. In addition, bubbles may be generated in the molded lens.
Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer include pressure-sensitive adhesives applied to general adhesive tapes such as acrylic, rubber-based, and silicon-based adhesives.

Such a molding mold 1 is assembled in a molding mold assembling process.
The molding mold 1 is assembled by arranging the molding surface 2a of the molding die 2 provided with the inlet 2b and the molding surface 3a of the molding die 3 so as to face each other at a predetermined interval. The adhesive tape 4 is wound a little more than one turn around the outer peripheral side surface, and the mold 2 and the mold 3 are bonded and fixed. When the adhesive tape 4 is wound, the one end surface in the width direction of the adhesive tape 4 is adhered to a position substantially coincident with the end of the outer peripheral side surface of the mold 3 on the non-molded surface (opposite surface of the molded surface 3a) side. Is done.

The molding mold 1 can be assembled using a tape winding device (not shown) that winds the adhesive tape 4 around the outer peripheral side surfaces of the two molds 2 and 3 and fixes them.
The tape winding device includes, for example, a spindle provided opposite to a central axis in the vertical direction, a linear device that moves the spindle in the central axis direction, and the like, and a molding die 2 that molds the convex surface of the lens on one spindle. The non-molding surface (the opposite surface of the molding surface 2a) is sucked and held, and the non-molding surface of the molding die 3 for molding the concave surface of the lens is sucked and held on the other spindle, and then the linear device is operated to form the molding surface 2a. And the molding surface 3a is moved to a position where the distance becomes a predetermined dimension, the adhesive tape 4 is wound around the outer peripheral side surfaces of the molding dies 2 and 3, and the molding dies 2 and 3 are adhered and fixed. Thereby, the molding mold 1 is assembled. The distance of the predetermined dimension between the molding surface 2a and the molding surface 3a corresponds to the center thickness of the lens to be molded.
Then, the molding mold 1 assembled in the molding mold assembling process shifts to the raw material injection process.

In the raw material injection step, the lens raw material M is injected into the cavity 5 of the molding mold 1 from the injection port 2 b provided in the molding die 2.
The lens raw material M is not particularly limited, and examples thereof include diethylene glycol bisallyl carbonate (CR-39). Further, as a lens material for a high refractive index, a material mainly composed of a polymerizable monomer mainly composed of a polyisocyanate having two or more isocyanate groups and a compound having two or more active hydrogens. It can be illustrated.

Examples of the polyisocyanate having two or more isocyanate groups include m-xylylene diisocyanate, p-xylylene diisocyanate, tetrachloro-m-xylylene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenation. Diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, 2,5-bis (isocyanatomethyl) bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) bicyclo [2.2.1] Heptane, 3,8-bis (isocyanatomethyl) tricyclo [5.2.1.0 ^2.6 ] -decane, 3,9-bis (isocyanatomethyl) tricyclo [5.2.1.0 ^2.6 ] -decane, 4,8-bis (isocyanatomethyl) tricyclo [5.2.1.0 ^2.6] - decane, 4,9 Scan (isocyanatomethyl) tricyclo [5.2.1.0 ^2.6] - decane, allophanate-modified products of polyisocyanate compounds and their compounds such as dimer acid diisocyanate, 1,3-bis (alpha, alpha- Dimethylisocyanatomethyl) benzene, 1,4-bis (α, α-dimethylisocyanatomethyl) benzene, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate Narate, tolidine diisocyanate, naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, biuretation reaction product of hexamethylene diisocyanate, adduct formation of hexamethylene diisocyanate and trimethylolpropane Examples of the compound include 4,4′-dicyclohexylmethane diisocyanate, isocyanurate-modified products, and the like. These compounds can be used alone or in admixture of two or more.

  Examples of the compound having two or more active hydrogens include a polyol having two or more hydroxyl groups, a polythiol having two or more thiol groups, and a compound having one or more hydroxyl groups and thiol groups in each molecule. Can be mentioned.

  Examples of the polyol having two or more hydroxyl groups include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, trimethylol ethane, trimethylol propane, butane triol, and 1,2-methyl. Glucoside, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol, erythritol, threitol, ribitol, arabinitol, xylitol, allitol, mannitol, dorscitol, iditol, glycol, inositol, hexanetriol, triglycerol, diglycerol, triethylene glycol, Polyethylene glycol, tris (2-hydroxyethyl) isocyanur , Cyclobutanediol, cyclopentanediol, cyclohexanediol, cycloheptanediol, cyclooctanediol, cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo [5,2,1,0,2,6] decane-dimethanol, bicyclo [4,3,0] -nonanediol, dicyclohexanediol, tricyclo [5,3,1,1] dodecanediol, bicyclo [4,3,0] nonanedimethanol, tricyclo [5,3,1,1] Dodecane-diethanol, hydroxypropyltricyclo [5,3,1,1] dodecanol, spiro [3,4] octanediol, butylcyclohexanediol, 1,1'-bicyclohexylidenediol, cyclohexanetriol, maltitol, lactito Dihydroxynaphthalene, trihydroxynaphthalene, tetrahydroxynaphthalene, dihydroxybenzene, benzenetriol, biphenyltetraol, pyrogallol, (hydroxynaphthyl) pyrogallol, trihydroxyphenanthrene, bisphenol A, bisphenol F, xylylene glycol, Aromatic polyols such as tetrabromobisphenol A, di- (2-hydroxyethyl) sulfide, 1,2-bis- (2-hydroxyethyl mercapto) ethane, bis (2-hydroxyethyl) disulfide, 1,4-dithiane 2,5-diol, bis (2,3-dihydroxypropyl) sulfide, tetrakis (4-hydroxy-2-thiabutyl) methane, tetrabromobisphenol S, teto Examples include polyols containing sulfur atoms such as methyl bisphenol S, 4,4′-thiobis (6-tert-butyl-3-methylphenol), 1,3-bis (2-hydroxyethylthioethyl) -cyclohexane. .

  Examples of polythiol having two or more thiol groups include 4-mercaptomethyl-3,6-dithio-1,8-octanedithiol, pentaerythritol tetrakis (3-mercaptopropionate), and tetrathiol. be able to.

  Examples of the compound having one or more hydroxyl groups and thiol groups in one molecule include 2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerol di (mercaptoacetate), 1-hydroxy-4- Mercaptocyclohexane, 2,4-dimercaptophenol, 2-mercaptohydroquinone, 4-mercaptophenol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3 -Butanediol, pentaerythritol tris (3-mercaptopropionate), pentaerythritol mono (3-mercaptopropionate), pentaerythritol bis (3-mercaptopropionate), pentaerythritol tris (thioglycolate) Pentaerythritol pentakis (3-mercaptopropionate), hydroxymethyl-tris (mercaptoethylthiomethyl) methane, 1-hydroxyethylthio-3-mercaptoethylthiobenzene, 4-hydroxy-4'-mercaptodiphenylsulfone, 2 Examples include-(2-mercaptoethylthio) ethanol, dihydroxyethyl sulfide mono (3-mercaptopropionate), dimercaptoethane mono (sulcylate), hydroxyethylthiomethyltris (mercaptoethylthio) methane, and the like.

  Furthermore, as another lens material M for high refractive index, a compound having one or more disulfide bonds (SS) in the molecule and having an epoxy group and / or a thioepoxy group can be exemplified. .

  These lens raw materials M can be blended with a polymerization catalyst. Examples of the polymerization catalyst include urethanization reaction catalysts such as dibutyltin dilaurate, dibutyltin dichloride, tin compounds such as dimethyltin dichloride, amine compounds such as tertiary amines, tertiary phosphines, and Lewis acids. It can be used alone or in combination. In addition, various chain extenders, crosslinkers, light stabilizers, UV absorbers, antioxidants, anti-coloring agents, bluing agents, dyes, pigments, leveling agents, fillers, internal release agents, etc., as necessary Can be added.

For injecting the lens material M into the cavity 5 of the molding mold 1, a lens material injection device 50 shown below can be used.
FIG. 2 is a block diagram showing a schematic configuration of the lens raw material injection apparatus. FIG. 2 partially includes a schematic cross-sectional view showing a mode of a molding mold in the lens raw material injection step.

In FIG. 2, a lens material injection device 50 includes a material supply device 51, an injection control valve 52, an injection nozzle 53, a flow rate adjustment device 54, which stores and supplies the lens material M injected into the cavity 5 of the molding mold 1. A control device 55, a suction nozzle 56, a vacuum generator 57, and a proximity sensor 58 are provided.
The lens raw material injection device 50 includes a moving device (not shown), and moves the injection nozzle 53 and the suction nozzle 56 independently in the vertical direction and the horizontal direction (vertical and horizontal directions with respect to the paper surface of FIG. 2). It has a mechanism to do.

  The injection control valve 52 is disposed on a supply flow path connecting the raw material supply device 51 and the injection nozzle 53, and starts and ends injection of the lens raw material M based on a control signal from the flow rate adjustment device 54. Switch the injection flow rate during injection.

The injection nozzle 53 is a nozzle for injecting the lens raw material M from the injection port 2b provided at the peripheral edge of the mold 2, and the outer diameter of the nozzle is about 2 mm.
The injection nozzle 53 is moved toward the injection port 2 b when the moving device is activated at the start of injection of the lens raw material M, and the nozzle tip enters the predetermined position in the cavity 5.
The flow rate adjusting device 54 controls the injection flow rate based on the control signal input from the control device 55.

The control device 55 controls each device constituting the lens raw material injection device 50.
The suction nozzle 56 is connected to the vacuum generator 57, and has a function of sucking the lens material M overflowing from the injection port 2b of the molding mold 1 into the nozzle when the lens material M injected into the cavity 5 is fully filled. Have Similar to the injection nozzle 53, the suction nozzle 56 is held at a predetermined position near the injection port 2 b provided in the mold 2 by operating the moving device at the start of injection of the lens material M. The suction nozzle 56 is always kept in a suction state by the vacuum generator 57 while the lens material injection device 50 is in operation.

  The proximity sensor 58 is a capacitance type proximity sensor, and is disposed on the suction nozzle 56 connected to the vacuum generator 57 and detects the lens material M sucked from the suction nozzle 56. The detected signal (full signal) is output to the control device 55.

  Next, an injection method for injecting the lens material M into the cavity 5 of the molding mold 1 using the lens material injection device 50 configured as described above will be described with reference to FIG.

First, the molding mold 1 assembled in the molding mold assembling process is held by the chuck (not shown) of the lens material injection device 50 with the surfaces of the molding dies 2 and 3 in the vertical direction. At that time, the injection port 2b provided in the mold 2 is positioned and held at the highest position (upper side) in the vertical direction. This is to make it easy to exhaust the air in the cavity 5 of the molding mold 1 when the lens material M is injected.
Therefore, the injection port 2b is positioned in a substantially horizontal direction with respect to the mold 2 held by the chuck.

Then, the moving device is operated and the injection nozzle 53 is moved toward the injection port 2b of the molding mold 1 held by the chuck so that the nozzle tip portion enters the cavity 5 and the nozzle tip portion of the suction nozzle 56. Is moved to a predetermined position in the vicinity of the inlet 2b provided in the mold 2 and held.
Then, the lens raw material M is injected from the raw material supply device 51 into the cavity 5 of the molding mold 1 through the injection control valve 52 and the injection nozzle 53. The start and end of injection and the switching of the injection flow rate during the injection are performed by the injection control valve 52, the flow rate adjusting device 54, and the control device 55.

  The injection pattern for injecting the lens material M into the cavity 5 is appropriately set based on the capacity of the cavity 5, the curvature of the lens surface of the lens to be molded, etc., but about 0.5 cc / sec to 10 cc / sec. It is desirable to set a small to large amount to a small amount of injection pattern between the initial injection and the final injection within the range of the injection flow rate. This is to reduce entrainment of air in the cavity 5 into the lens material M when the lens material M is injected.

  Then, as the lens material M is injected into the cavity 5 from the injection nozzle 53, the liquid level of the lens material M gradually rises, and when the cavity 5 is filled with the lens material M, the lens material M is injected from the injection port 2b. Overflows. The lens material M overflowing from the cavity 5 is sucked from the suction nozzle 56 connected to the vacuum generator 57 together with the air in the cavity 5.

When the lens material M sucked by the suction nozzle 56 reaches the proximity sensor 58 arranged on the suction nozzle 56, the proximity sensor 58 detects the presence of the lens material M. That is, it is detected that the lens material M is filled in the cavity 5 of the molding mold 1. When the lens raw material M is detected by the proximity sensor 58, a full signal is output to the control device 55.
Then, the control device 55 outputs a signal for stopping the injection of the lens material M to the flow rate adjusting device 54, the injection control valve 52 is closed via the flow rate adjusting device 54, and the supply of the lens material M is stopped.

  At the time of such injection of the lens material M, the outer diameter of the nozzle passing through the injection port 2b is about 2 mm while the diameter of the injection port 2b provided in the mold 2 is about 5 mm. The air in the cavity 5 that has lost its destination is discharged from the inlet 2b, and the lens material M filled in the cavity 5 is discharged. Thereby, it is possible to prevent bubbles from being entrained in the lens material M. Furthermore, since the suction state of the suction nozzle 56 is maintained during the operation of the lens raw material injection device 50, the air in the cavity 5 is forcibly sucked to prevent air bubbles from being entrained in the lens raw material M. be able to. Further, the lens raw material M is easily drawn into the cavity 5, and the injection time for filling the cavity 5 can be shortened.

Then, after the moving device is operated and the injection nozzle 53 and the suction nozzle 56 are retracted from the cavity 5 of the molding mold 1 and the vicinity of the injection port 2b of the molding die 2, the lens raw material M is fully filled in the cavity 5. The filled molding mold 1 is removed from the lens material injection device 50, and the injection of the lens material M is completed.
The molding mold 1 removed from the lens raw material injection device 50 moves to the sealing step.

In the sealing step, the injection port 2b of the molding mold 1 filled with the lens material M is sealed.
The injection port 2b is sealed by dropping a sufficient amount of ultraviolet curable resin onto the injection port 2b so as to cover the injection port 2b, and then using an ultraviolet irradiation device or the like to the dropped ultraviolet curable resin. Then, an ultraviolet ray having an output of about 200 W is irradiated for about 15 seconds, and the ultraviolet curable resin is fixed to the surface of the mold 2 to seal the injection port 2b.

When sealing the injection port 2b, the ultraviolet curable resin can simultaneously cure the lens raw material M adhering to the surface of the mold 2 by functional group crosslinking reaction, thereby sealing the injection port 2b. The functional group is a reactive vinyl group, allyl group, (meth) acryl group, organic acid ester group, isocyano group, isothiocyano group, hydroxyl group, amino group, cyano group, mercapto group, carboxyl group, epoxy group alone Also refers to mixed monomers and prepolymers. As the ultraviolet curable resin used for sealing, any type of resin can be selected and used as long as the lens raw material M to be molded and the functional group cause a crosslinking reaction.
Then, the molding mold 1 in which the injection port 2b is sealed moves to the polymerization curing step.

In the polymerization curing step, polymerization curing of the lens raw material M filled in the cavity 5 of the molding mold 1 is performed.
In the polymerization curing, the molding mold 1 is heated and the lens material M in the cavity 5 is cured. In the polymerization curing, the molding mold 1 with the inlet 2b sealed is placed in a heating furnace, and the temperature in the furnace is gradually increased from about 30 ° C. to about 120 ° C. over about 20 hours. Done.

Thereafter, after the polymerization-cured molding mold 1 is taken out from the heating furnace, the adhesive tape 4 is peeled off from the molding dies 2 and 3, the molding dies 2 and 3 are removed, and the molding die 2 is molded on the convex surface. A plastic lens having the surface 2a transferred and the molding surface 3a of the mold 3 transferred to the concave surface is obtained.
As a plastic lens molded using such a molding mold 1, for example, it can be applied to various optical lenses such as a plastic spectacle lens, a digital still camera, a video camera, a telescope, and a binocular.

This embodiment has the following effects.
(1) By having the injection port 2b as an opening in the vicinity of the periphery of the molding surface 2a of the mold 2, the lens material M can be injected from the injection port 2b into the cavity 5 of the molding mold 1. . Therefore, there is no need to pierce the injection tape or the like into the adhesive tape 4 adhered to the outer peripheral side surfaces of the molds 2 and 3, or to peel off the adhesive tape 4 to form an opening, and the adhesive 5 is adhered to the cavity 5. Intrusion of foreign matter such as a base material piece of the tape 4 and an adhesive can be prevented, and optical performance and appearance quality can be prevented from being impaired. Further, since the injection port 2b provided in the mold 2 is in the vicinity of the peripheral portion of the molding surface 2a, which is an area other than the lens usage area, the lens usage area of the lens to be molded is not narrowed.

  (2) By setting the size of the injection port 2b to be at least larger than the nozzle diameter of the injection nozzle 53 for injecting the lens raw material M into the cavity 5, it serves as an exhaust port for exhausting the air in the cavity 5. Can also function. Therefore, it is possible to prevent the appearance quality and optical characteristics of the lens formed by bubbles remaining in the cavity 5 from being impaired.

  (3) The molding mold 1 assembled in the molding mold assembling process using the molding die 2 provided with the inlet 2b is arranged in the vertical direction with the inlet 2b facing upward in the raw material injecting process. By injecting the lens raw material M from the injection port 2 b into the nozzle 5, the injection port 2 b can also function as an exhaust port for exhausting the air in the cavity 5. As a result, a plastic lens excellent in appearance quality and optical characteristics free from foreign matters and bubbles can be obtained.

  (4) An injection port in which the suction nozzle 56 having a function of sucking the lens material M overflowing from the cavity 5 of the molding mold 1 into the nozzle also serves as an exhaust port for discharging the air in the cavity 5. By being held at a predetermined position in the vicinity of 2b, the air in the cavity 5 can be forcibly sucked and air bubbles can be further prevented from being entrained in the lens material M. Further, the lens raw material M is easily drawn into the cavity 5, and the injection time for filling the cavity 5 can be shortened.

[Second Embodiment]
FIG. 3A is a front view of a molding mold according to the second embodiment, and FIG. 3B is a cross-sectional view of the molding mold.
The second embodiment is different from the first embodiment only in the arrangement of the apertures provided in the mold and the method of injecting the lens raw material into the cavity 5 of the mold for molding. This is the same as in the first embodiment. Therefore, in FIGS. 3 and 4, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. The same applies to the lens manufacturing method other than the lens raw material injection step (lens raw material injection method), and the detailed description thereof is omitted or simplified.

In FIG. 3, a molding mold 10 includes a first molding die 12 (hereinafter referred to as a molding die 12) that molds one surface of a lens and a second molding die that molds the other surface of the lens. 13 (hereinafter referred to as a mold 13) and two lens molds (hereinafter also referred to as a mold), and an adhesive tape 4 wound around the outer peripheral side surfaces of the molds 12 and 13 It is configured.
The molding mold 10 has two molding dies 12 and 13 arranged opposite to each other at a predetermined interval, and the adhesive tape 4 is wound a little more than one round on the outer peripheral side surface. At the same time, the gap between the mold 12 and the mold 13 is closed to form the cavity 5.

  The molding die 13 has, for example, a molding surface 13a as a lens surface for molding a concave surface, and an injection port 13b and an exhaust port as openings that penetrate in the thickness direction of the molding die 13 in a region other than the lens use region. 13c. The injection port 13b and the exhaust port 13c are provided in a region other than the lens use region, and are provided, for example, at a position approximately equidistant from the center of the circle on the center line of the circular mold 13. That is, it is provided at a position that is substantially symmetrical with respect to the center of the molding surface 13 a of the mold 13.

  The injection port 13 b is a hole through which the injection nozzle 53 for injecting the lens raw material M into the cavity 5 is passed. The exhaust port 13 c has both a function of discharging the air in the cavity 5 when the lens material M is injected and a function of a discharge port from which the lens material M filled in the cavity 5 overflows. The diameters of the inlet 13b and the exhaust port 13c are, for example, about 4 mm, respectively, and are formed by hot press processing or punching using a diamond drill or the like in a molded glass mold.

  The diameters of the injection port 13b and the exhaust port 13c are not limited to this, and can be set as appropriate according to the thickness of the injection nozzle 53 for injecting the lens material, the suction force of the vacuum generator 57, and the like. Further, the injection port and the exhaust port may be provided in the mold 12 instead of the mold 13.

Next, an injection method (lens raw material injection step) for injecting the lens raw material M into the cavity 5 of the molding mold 10 thus configured will be described with reference to FIG.
FIG. 4 is a block diagram showing a schematic configuration of a lens raw material injection apparatus according to the second embodiment, including a schematic cross-sectional view showing an aspect of a molding mold in the lens raw material injection step.

First, the molding mold 10 assembled in the molding mold assembling process is held on the chuck of the lens raw material injection device 60 with the molding die 13 on the upper side and inclined with respect to the vertical direction. Further, at that time, the position of the exhaust port 13c is higher than that of the injection port 13b, and the exhaust port 13c is positioned and held in a state where it is positioned at the uppermost side. That is, the exhaust port 13c is positioned and held in a state where it is located on the lower side in the vertical direction.
The inclination angle of the molding mold 10 may be set so that the distance α in the vertical direction between the inlet 13b and the outlet 13c shown in FIG. 4 exceeds at least 0 (zero). It is set appropriately in consideration of the type and viscosity of the polymer composition of the lens material M injected into the cavity 5 of the molding mold 10.

Then, the moving device is operated and the injection nozzle 53 is moved toward the injection port 13b provided in the molding die 13 of the molding mold 10 held by the chuck, and the nozzle tip portion enters the cavity 5, The nozzle tip of the suction nozzle 56 is moved to a predetermined position near the exhaust port 13c and held.
Then, the lens material M is injected from the material supply device 51 into the cavity 5 of the molding mold 10 through the injection control valve 52 and the injection nozzle 53.

Then, the lens material M is filled into the cavity 5 from the injection nozzle 53, and when the cavity 5 is filled with the lens material M, the lens material M overflows from the exhaust port 13c. The lens material M overflowing from the cavity 5 is sucked by the suction nozzle 56 connected to the vacuum generator 57.
When the lens raw material M sucked by the suction nozzle 56 reaches the proximity sensor 58 provided on the suction nozzle 56, the proximity sensor 58 detects the presence of the lens raw material M, and a signal indicating the completion of filling is indicated by the control device 55. Then, the injection control valve 52 is closed via the flow rate adjusting device 54 and the supply of the lens material M is stopped.

  Then, after the moving device is operated and the injection nozzle 53 and the suction nozzle 56 are lifted and separated from the cavity 5 of the molding mold 10 and the exhaust port 13 c of the molding die 13, the lens material M is placed in the cavity 5. Is completely removed from the lens material injection device 60, and the injection of the lens material M is completed.

Then, the molding mold 10 is removed from the lens raw material injection device 60, and the process proceeds to the sealing process and the polymerization curing process.
In the sealing step, after the injection port 13b and the exhaust port 13c are sealed using an ultraviolet curable resin, the polymerization curing of the lens material M filled in the cavity 5 of the molding mold 10 is performed in the polymerization curing step. Thus, a plastic lens is obtained in which the molding surface 12a of the molding die 12 is transferred to the convex surface and the molding surface 13a of the molding die 13 is transferred to the concave surface.

According to the second embodiment, in addition to the effects (1) and (4) of the first embodiment, the following effects can be achieved.
(1) By providing an injection port 13b for injecting the lens raw material M into the cavity 5 and an exhaust port 13c for exhausting the air in the cavity 5 on the molding surface 13a of the mold 13, Air in the cavity 5 can be efficiently exhausted, and bubbles can remain in the cavity 5 to prevent the appearance quality and optical characteristics of the molded lens from being impaired. In addition, by providing the two opening portions of the injection port 13b and the exhaust port 13c, the opening portion is not enlarged, and it is possible to reduce the narrowing of the lens use area to be molded.

  (2) Molding mold assembly using the molding die 13 in which two opening portions of the injection port 13b and the exhaust port 13c are provided on the molding surface 13a of the molding die 13 at positions substantially symmetrical with respect to the center of the surface. The molding mold 10 assembled in the process is disposed so as to be inclined with respect to the vertical direction with respect to the molding die 13 provided with two apertures on the upper surface side, and the injection port 13b on the lower side in the vertical direction ( That is, the lens raw material M is injected into the cavity 5 from the injection port 13b in the raw material injection step with the exhaust port 13c being on the lower side in the vertical direction), so that the air in the cavity 5 can be comfortably out of the cavity 5. It is possible to further prevent air bubbles from being entrained in the lens material M to be exhausted and injected. As a result, a plastic lens excellent in appearance quality and optical characteristics free from foreign matters and bubbles can be obtained.

[Modification of Embodiment]
The present invention is not limited to the first and second embodiments described above, but includes modifications and improvements as long as the object of the present invention can be achieved. Even if it is a form which is mentioned as a modification below, the same effect as the above-mentioned embodiment can be acquired.

  (1) Injection port 2b as an opening provided in the first mold 2 in the first embodiment, and injection port as an opening provided in the second mold 13 in the second embodiment Although 13b and the exhaust port 13c demonstrated in the case where the through-hole penetrated in the thickness direction of each shaping | molding die was provided, it is not limited to a through-hole. For example, it can be formed as follows.

FIG. 5 is a plan view of a mold showing a modification of the mold.
As for the shaping | molding die 22 as a 1st shaping | molding die or a 2nd shaping | molding die, the recessed part 22a is formed on the circular periphery. For example, the recess 22 a is formed in a shape in which an arc having a radius of about 2.5 mm is recessed about 4 mm from the outer periphery in the center direction of the mold 22. The concave portion 22a can be easily formed by providing a nest or the like in a processing die such as hot press processing or die forming for forming the molding die 22.

When the lens raw material M is injected into the cavity 5 of the molding mold assembled using the molding die 22, the injection nozzle 53 is formed in the region formed between the recess 22 a of the molding die 22 and the adhesive tape 4. Inserted and done.
When an exhaust port composed of a recess is provided, the suction nozzle 56 is held in the vicinity of the region formed between the recess and the adhesive tape 4 to exhaust the air in the cavity 5 and overflow from the cavity 5. The lens material M is sucked.

The shape of the recess 22a may be any shape such as a rectangular shape or an elliptical arc as long as it is a recess provided on the circular periphery of the mold. The size of the recess 22a is desirably as small as possible, and can be appropriately set in consideration of the nozzle diameter of the injection nozzle 53 that injects the lens material M into the cavity 5. For example, when one concave portion 22a is provided as an injection port, the gap between the injection nozzle inserted into the concave portion 22a and the concave portion 22a discharges the air in the cavity 5 and further fills the cavity 5 with the lens material. If it is possible to overflow, it will not be limited.
Moreover, when providing two opening parts, an injection port and an exhaust port, either one opening part may be formed with a through-hole, and the other one opening part may be formed with a recessed part.

  Thus, by using the molding die 22 in which the concave portion 22a is formed on the circular periphery as the opening portion, the lens usage region can be used more widely. In addition, since the mold 22 having the recess 22a can be formed simultaneously with the molding surface during mold processing such as hot press or mold molding, there is no need to perform secondary processing such as drilling, and the lens mold This can contribute to cost reduction.

  (2) In the sealing step in the first embodiment and the second embodiment, the injection port 2b provided in the molding mold 1 and the injection port 13b and the exhaust port 13c provided in the molding mold 10 emit ultraviolet rays. As described in the case where the resin is fixed and sealed on the surface of each mold using an ultraviolet curable resin that is cured by irradiation, hot melt, epoxy adhesive, silicon adhesive, rubber adhesive, or A thermosetting adhesive or the like can be used.

  (3) In the plastic lens, the molding surfaces of the two molding dies are formed on the final optical surface, and the final lens is transferred only on the molding surface of one of the two molding dies. There is a semi-finished lens in which the shape of the molding surface side that does not have the other optical characteristic is formed by polishing or the like, and further, a convex lens and a concave lens, and two types of lens raw materials in order Although there exists a hybrid lens etc. which were shape | molded, it can apply similarly to the lens shaping | molding die which shape | molds any plastic lens.

(A) is an external appearance schematic diagram of the molding mold which concerns on 1st Embodiment. FIG. 2B is a front view of the molding mold according to the first embodiment. (C) is sectional drawing of the mold for shaping | molding which concerns on 1st Embodiment. The block diagram which shows schematic structure of the lens raw material injection apparatus which concerns on 1st Embodiment. (A) is a front view of the mold for molding concerning a 2nd embodiment. (B) is sectional drawing of the mold for shaping | molding which concerns on 2nd Embodiment. The block diagram which shows schematic structure of the lens raw material injection apparatus which concerns on 2nd Embodiment. The top view of the shaping | molding die which shows the modification of a shaping | molding die.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,10 ... Mold for shaping | molding, 2, 12, 22 ... 1st shaping | molding die, 2a, 3a, 12a, 13a ... Molding surface, 2b, 13b ... Injection hole as opening part, 3 ... 2nd shaping | molding die DESCRIPTION OF SYMBOLS 4 ... Adhesive tape, 5 ... Cavity, 13c ... Exhaust port as an opening part, 22a ... Recessed part as an opening part, 50, 60 ... Lens raw material injection apparatus, 51 ... Raw material supply apparatus, 52 ... Injection control valve, 53 ... Injection nozzle, 54 ... Flow rate adjusting device, 55 ... Control device, 56 ... Suction nozzle, 57 ... Vacuum generator, 58 ... Proximity sensor, M ... Lens raw material.

Claims (9)

A first mold that molds one surface of the lens and a second mold that molds the other surface of the lens face each other at a predetermined interval, and the first mold and the second mold In a cavity formed by sticking an adhesive tape to the outer peripheral side of the lens, a lens molding die for molding a plastic lens by injecting a lens raw material,
At least one of the first mold and the second mold has at least one aperture in a region other than the lens use region. . The lens mold according to claim 1,
An area other than the lens use area is near the periphery of the lens mold. In the lens mold according to claim 1 or 2,
The lens mold, wherein the opening is a through-hole penetrating in the thickness direction of the lens mold or a recess including a peripheral edge of the lens mold. In the lens shaping | molding die as described in any one of Claims 1-3,
At least one lens molding die of the first molding die and the second molding die has one opening portion. In the lens shaping | molding die as described in any one of Claims 1-3,
A lens molding die comprising two aperture portions in at least one of the first molding die and the second molding die. In the lens mold according to claim 5,
2. The lens mold according to claim 1, wherein the two apertures are provided at substantially symmetrical positions with respect to the surface center of the lens mold. A first mold that molds one surface of the lens and a second mold that molds the other surface of the lens face each other at a predetermined interval, and the first mold and the second mold A plastic lens manufacturing method for injecting a lens raw material into a cavity formed by adhering an adhesive tape to the outer peripheral side surface of a plastic lens,
A molding mold assembling step for assembling a molding mold for molding a plastic lens using the lens molding die according to any one of claims 1 to 6;
A raw material injecting step of injecting a lens raw material from the aperture provided in the lens mold in the cavity of the molding mold;
A sealing step for sealing the opening,
A polymerization curing step for curing the lens material injected into the cavity of the molding mold;
In this order. A method for producing a plastic lens. In the manufacturing method of the plastic lens of Claim 7,
In the molding mold assembling step, a molding mold is assembled using the lens mold according to claim 4,
In the raw material injection step, the molding mold is arranged so that the surface of the lens mold provided with the aperture is in the vertical direction, and the aperture is positioned on the upper side in the vertical direction. A method of manufacturing a plastic lens, wherein the lens raw material is injected from a portion. In the manufacturing method of the plastic lens of Claim 7,
In the molding mold assembling step, a molding mold is assembled using the lens molding die according to claim 5 or 6,
In the raw material injection step, the molding mold is disposed so as to be inclined with respect to the vertical direction with the surface of the lens molding die provided with the two apertures on the upper side, and the two apertures A method of manufacturing a plastic lens, comprising injecting the lens raw material with one of the apertures being downward in the vertical direction.

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