JP4869054B2 - How to remove a contact lens from a resin mold - Google Patents

Description

  The present invention relates to a method for removing a contact lens polymerized by a cast mold manufacturing method from a resin mold.

  Clinical results have pointed out that when contact lenses are worn, oxygen supply from the atmosphere decreases, resulting in suppression of corneal epithelial cell division and corneal thickening. Therefore, in order to supply a contact lens with higher safety, attempts have been made to improve the oxygen permeability of the material.

In the case of hydrous soft contact lenses, it is known that the wear feeling is good due to the suppleness of the material, but its oxygen permeability is due to the moisture content of the lens, so compared to hard contact lenses Low. For example, in the case of a hydrous soft contact lens, the oxygen permeability coefficient of a material having a moisture content of 80% is about 40 × 10 ⁻¹¹ (cm ² / sec) · (mLO ₂ / mL × mmHg), which is sufficient for the cornea It cannot be said that a sufficient amount of oxygen can be supplied.

  For this reason, in soft contact lenses, contact lenses using silicone-containing monomers and siloxane macromers for improving oxygen permeability and fluorine-containing monomers as lens components for the purpose of preventing contamination are proposed. .

  For example, Patent Document 1 discloses a soft contact lens material excellent in flexibility and oxygen permeability, using a macromer having a dimethylsiloxane structure in the side chain. However, in general, when a silicone component is used for the lens material, the lens surface is sticky, so even if the lens does not peel off when the lens is peeled off from the mold after the cast mold manufacturing method, Since static electricity is generated between the mold and the lens, foreign matters (dust, dust, etc.) in the air are adsorbed on the lens surface, which has many problems in the manufacturing process.

  Specifically, in order to peel off the contact lens to which the concave mold is attached, when the surface opposite to the surface to which the contact lens is adhered is simply hit with a press head, the contact is caused by the press head contacting the concave mold. Friction occurs between the lens and the concave mold. As a result, static electricity is generated, and the contact lens may be charged with static electricity, which is not preferable for application to an industrial production line.

  In addition, if the pulling force is separated without transmitting it in parallel (that is, when the concave and convex molds are separated in a slanting posture), the resin mold to which the lens is attached is not constant, and sometimes the concave mold. In addition, in some cases, it adheres to the convex mold, and the ring-shaped polymer adheres to the concave mold, which is not preferable for application to an industrial production line.

  Patent Document 2 discloses a method of peeling a contact lens from a mold by forming a silicon contact lens with a mold and then immersing the mold attached to the silicon contact lens in an organic solution. . However, in this method, by immersing the contact lens in an organic solvent, it becomes necessary to re-dry the lens before the subsequent surface modification step. There has been a problem that the manufacturing process becomes complicated, for example, because a foreign matter may adhere and the surface may be contaminated.

  Patent Document 3 discloses a method for improving the peelability of a polymer from a mold by applying a surfactant to the surface of one mold. However, by applying a surfactant, the surface energy of the mold surface is reduced and the peelability is improved. However, it is conceivable that the surfactant is mixed in the obtained contact lens, which is preferable from the viewpoint of safety. There was no problem.

  Patent Document 4 discloses a method in which a cryogenic substance is brought into contact with a mold having a contact lens attached thereto, and the temperature of the contact lens is lowered to reduce the adhesiveness and peel off the mold. However, this method requires a special device for bringing the cryogenic material into contact with the mold, or needs to possess a large amount of the cryogenic material. There is a problem that it is not preferable in consideration of safety.

JP 2001-311917 A Japanese Examined Patent Publication No. 58-52813 JP-A-9-183131 Special table 2003-512206 gazette

  From the above background, when contact lenses are manufactured by the cast mold manufacturing method, the development of a method to take out the polymerized contact lenses in a dry state without using a special solvent or solvent when considering the subsequent processes. Was desired.

  In consideration of the above circumstances, the present invention provides a method for taking out a contact lens that can be easily taken out of a resin mold in a clean and dry state without using a solvent or a solvent. The purpose is to provide.

  As a result of earnest investigation on the method of taking out a contact lens containing silicone as a component without adsorbing foreign matter on the lens surface without requiring a special solvent, a solvent, or an apparatus, the present inventor By pressing the concave convex outer surface using a head, the lens molding surface of the concave inner surface is deformed in a direction in which the curvature increases, thereby causing a difference in curvature between the lens and the resin mold, so that the lens The inventors have found that the resin mold spontaneously falls and came up with the present invention.

That is, the invention of claim 1 uses a resin mold comprising a concave mold and a convex mold each having a lens molding surface formed on the inner surface, and holds the concave mold with the lens molding surface facing upward. Cast material manufacturing method is carried out by injecting liquid raw material containing silicone into the concave mold and fitting the convex mold from above into the concave mold to polymerize the raw material in the concave mold and convex mold to produce contact lenses After removing the contact lens from the resin mold,
(A) a step of separating the concave mold and the convex mold after polymerization so that the contact lens adheres to the concave mold side;
(B) An outer surface having a convex curvature facing upwards on the opposite side to the concave lens molding surface, holding the concave mold with the contact lens attached in an upside down orientation so that the inner lens molding surface faces downward The center part of the lens is pressed downward relative to the peripheral part using a press head, so that the concave lens molding surface is deformed in the direction in which the curvature increases, and the contact lens attached to the inner surface is naturally A step of dropping,
It is characterized by having.

The invention of claim 2 is the invention of claim 1,
In the step (A), a claw is inserted between a peripheral flange provided on the concave mold and a peripheral flange provided on the convex mold, and the concave peripheral flange and the convex mold are parallel to each other. A force for pulling away from the peripheral flange in a direction perpendicular to the peripheral flange is applied to the claw.

The invention of claim 3 is the invention of claim 1 or 2,
In the step (B), using a press head having a pressing surface with a single curvature radius in the range of 20 to 80 mm larger than the curvature radius of the outer surface of the concave mold, the central portion of the outer surface of the concave mold is surrounded by the pressing surface. It is characterized in that the molded contact lens is naturally dropped by pressing downward relative to the part.

The invention of claim 4 is the invention of any one of claims 1 to 3,
In the step (B), the concave mold to which the contact lens is attached is held in an upside down posture so that the lens molding surface faces downward by placing the lower end of the cylindrical peripheral wall of the concave mold on the cradle. As a pedestal, it has an opening through which the dropped contact lens passes in the center, and the pedestal surface on which the lower end of the cylindrical peripheral wall around the pedestal is a flat surface or an inclined surface inclined downward from the inner peripheral side toward the outer peripheral side It is characterized by using a cradle composed of

The invention of claim 5 is the invention of any one of claims 1 to 4,
The contact lens that naturally dropped in the step (B) is further received by using a suction pad and taken out to another place.

  According to invention of Claim 1, the contact lens shape | molded with the cast mold manufacturing method can be easily taken out from a resin type | mold in a clean and dry state, without using a solvent or a solvent.

  According to the invention of claim 2, when the resin mold is opened, the contact lens after polymerization can be reliably attached to the inner surface of the concave mold, and can be applied to mass production.

  According to invention of Claim 3, a contact lens can be easily taken out from a concave mold | type without giving a damage, and can be applied to mass production.

  According to the invention of claim 4, when the pedestal surface of the pedestal is a flat surface, alignment when pressing the concave convex outer surface with the press head is properly performed, and the concave inner surface is deformed. Is stable. Further, when the pedestal surface of the pedestal is an inclined surface, when the concave convex outer surface is pressed by the press head, the concave inner surface is easily deformed in the direction of increasing the curvature, and the press load can be reduced.

  According to the fifth aspect of the present invention, the contact lens that naturally falls can be safely received and transported to another place as it is.

Hereinafter, embodiments of the present invention will be described in detail.
First, a base material for manufacturing a contact lens will be described.
The contact lens substrate may be a polymer that can maintain a contact lens shape after polymerization and can be a hydrogel, preferably a copolymer that contains silicone and can be a hydrogel. What is known as can be used as it is.

  Specifically, as such a contact lens substrate, a copolymer obtained by polymerizing at least one silicone-containing monomer or a mixture containing a silicone-containing macromonomer and at least one hydrophilic monomer is used. The contact lens base material which becomes can be mentioned. Examples of applicable silicone monomers include tris (trimethylsiloxy) -γ-methacryloxypropylsilane, and examples of silicone-containing macromonomers include polysiloxanes in the side chain as shown in the following general formula (I). Examples include macromonomers having a structure.

  In particular, in the case of a contact lens substrate having a component represented by the following general formula (I), it becomes a material excellent in impact resistance due to having a urethane bond, and the lens is scratched with respect to the method of the present invention. This is particularly effective because it can be peeled off from the mold without causing any defects.

In the formula (I), R ₁ , R ₂ and R ₃ are independently selected from a C1-C4 alkyl group, R ₄ is selected from a C1-C6 alkyl group, R ₅ is aliphatic, A residue obtained by removing NCO from an alicyclic or aromatic diisocyanate, R ₆ , R ₇ , R ₈ and R ₉ are independently selected from C1-C3 alkylene, and n is an integer of 4-80 , M and p are each independently an integer of 3 to 40.

  Specific examples include a siloxane macromonomer having a polysiloxane structure in the side chain represented by the formula (I) and having a number average molecular weight of about 1000 to 10,000. Examples of the hydrophilic monomer include 2-hydroxyethyl methacrylate, N, N-dimethylacrylamide, N-vinyl-2-pyrrolidone and methacrylic acid. For details of the contact lens substrate that can be used in the present invention, Patent Document 1 can be referred to.

  In addition, the contact lens base material is polymerized by a cast mold manufacturing method, and the material of the mold at this time may be any material as long as it has resistance to the monomer mixture, for example, polypropylene. Can be mentioned.

The method of the present invention starts from a step of first separating a mold after polymerization (hereinafter also referred to as a resin mold). In the cast mold manufacturing method, a mold that forms a front curve (hereinafter,
Injecting a monomer mixture that forms a lens into a concave mold), combining it with a mold that forms a base curve (hereinafter referred to as a convex mold), and then irradiating it with heat or light (ultraviolet and / or visible light) Then, the monomer mixed solution in the resin mold is cured.

  In addition, the monomer mixture is poured into the concave mold in a larger amount than that for forming the lens, and excess monomer overflows when the upper mold is combined. Thereby, bubbles are not mixed in the lens after curing, and the quality is improved.

  This overflowing monomer mixture becomes a ring-shaped polymer after curing, but it is a very important problem whether this ring-shaped polymer is attached to the concave or convex after separation of the resin mold. Become. If a ring-shaped polymer is attached to the concave mold, then, as will be described later, the concave mold with the contact lens attached is reversed, and the outer surface portion having a convex curvature is pressed using a press head. This is because the lens is prevented from falling naturally, making it difficult to remove the lens from the resin mold.

  As a result of intensive studies, the present inventor inserted a claw between the peripheral flange provided in the concave mold and the peripheral flange provided in the convex mold when separating the resin mold after polymerization, and parallel to each other. By applying a force to the nail to pull away from the concave peripheral flange and the convex peripheral flange in the vertical direction, the concave mold and the convex mold are separated from each other while maintaining a parallel posture to each other. It was found that the contact lens after polymerization adhered, and a cured ring polymer of the monomer mixture overflowing into the convex shape adhered.

  Therefore, in the present invention, first, it is necessary to separate the resin mold by inserting a claw between the peripheral flanges of the uneven resin mold and applying a force to the claw. The claw is inserted between a peripheral flange provided in the concave shape and a peripheral flange provided in the convex shape. The inserted claw is applied with a force for pulling it away in the vertical direction with respect to the concave peripheral flange and the convex peripheral flange that are parallel to each other. Each of the concave mold and the convex mold separated by the nail is separated while maintaining a parallel posture. As a result, the contact lens is attached to the concave mold. This facilitates manufacturing.

  Next, in order to peel the lens from the resin mold, the concave mold to which the contact lens is attached is held upside down, and the outer surface portion having the convex curvature opposite to the lens molding surface is pressed using a press head. The resin mold is deformed in the direction in which the curvature of the lens molding surface is increased. As a result, the lens naturally falls from the resin mold.

  In short, in order to peel the contact lens from the concave mold, the difference in curvature between the generated contact lens and the concave mold is used. Specifically, the curvature of the concave mold changes due to the press head pressing the concave mold while the press head and the concave mold are in contact with each other. That is, the press head does not hit the concave mold but presses the concave mold. At that time, the press head presses the concave mold while in contact with the concave mold, so that friction does not occur and the contact lens is not charged with static electricity. As a result, the contact lens can be easily peeled from the concave mold, and foreign matter does not adhere to the contact lens surface. Thereby, the surface of the contact lens can be kept clean, and the process can easily proceed to the next step.

Specific examples will be described below with reference to the drawings.
FIG. 1 is an explanatory diagram when a contact lens is manufactured by a cast mold manufacturing method. In the cast mold manufacturing method, a resin mold composed of a concave mold 10 and a convex mold 20 each having lens molding surfaces 11 and 21 formed on the inner surface is used, and the concave mold 10 is held with the lens molding surface 11 facing upward. By injecting a liquid raw material containing silicone into the concave mold 10 and fitting the convex mold 20 into the concave mold 10 from above, the raw material is polymerized in the concave mold 10 and the convex mold 20, and the contact lens 100. Manufacturing.

  The lens molding surface 11 of the concave mold 10 is a surface that molds a front curve, and the outer surface 12 opposite to the lens molding surface 11 is a convex spherical surface having a predetermined curvature. In addition, a cylindrical peripheral wall 14 that fits the convex mold 20 is provided outside the lens molding surface 11, and a peripheral flange 13 is provided in a bowl shape on the outer side.

  The lens molding surface 21 of the convex mold 20 is a surface for molding a base curve, and the outer surface 22 opposite to the lens molding surface 21 is a concave spherical surface having a predetermined curvature. A cylindrical peripheral wall 24 that fits with the inner periphery of the cylindrical peripheral wall 14 of the concave mold 10 is provided on the outer side of the lens molding surface 21, and a peripheral flange 23 is provided on the outer side thereof in a bowl shape. When the concave mold 10 and the convex mold 20 are fitted together, an appropriate gap is formed between the peripheral flanges 13 and 23.

  After the contact lens 100 is polymerized by fitting the concave mold 10 and the convex mold 20, when the contact lens 100 is taken out from the resin mold, first, the superimposed concave mold 10 and convex mold 20 are placed on the inner surface side of the concave mold 10. To separate.

  That is, as shown in FIG. 2, in this example, the claws 31 a and 32 a of the jigs 31 and 32 are separated between the peripheral flanges 13 and 23 of the concave mold 10 and the convex mold 20 with the resin mold turned upside down. Is inserted into the claws 31a and 32a, and the concave mold 10 and the convex mold 20 are separated from each other while being parallel to each other. The separating jigs 31 and 32 are divided in half or in two parts so that the claws 31a and 32a can be inserted between the peripheral flanges 13 and 23 later.

  When the concave mold 10 and the convex mold 20 are separated as described above, the contact lens 100 is attached to the inner surface of the concave mold 10 as shown in FIG. Further, a ring-shaped polymer (not shown) remains on the convex mold 20 side.

  Next, as shown in FIG. 4, the concave mold 10 to which the contact lens 100 is attached is placed on the pedestal surface 41 of the pedestal 40 with the inner lens molding surface 11 facing downward. The cradle 40 has an opening 45 through which the dropped contact lens 100 passes in the center, and a pedestal surface 41 on the lower end of the cylindrical peripheral wall 14 of the concave mold 10 around the pedestal 40. The annular standing wall 42 with which the inner periphery of the lower end of the cylindrical peripheral wall 14 of the concave mold 10 is fitted to the peripheral portion is provided.

  As shown in FIG. 4, when the concave mold 10 to which the contact lens 100 is attached is placed on the pedestal surface 41 of the cradle 40 with the lens molding surface 11 facing downward, the lens molding surface of the concave mold 10 in that state. 11 is pushed down by the concave spherical pressing surface 51 of the press head 50 descending from above.

  That is, as shown in FIG. 5, the central portion of the outer surface 12 of the concave mold 10 is pressed downward relative to the peripheral portion supported by the cradle 40. Then, the concave portion 10 is deformed as indicated by arrows B1 and B2 in FIG. 6 by pressing the central portion with the downward force P1 with respect to the force P2 that supports the peripheral portion upward. That is, the lens molding surface 11 of the concave mold 10 is deformed in a direction in which the curvature increases, and a difference in curvature is generated between the contact lens 100 attached to the inner surface, and the attached contact lens 100 is thus formed into the concave mold. 10 is peeled off from the lens molding surface 11 and spontaneously falls as indicated by an arrow C.

The contact lens 100 that has fallen naturally is received by the suction surface 61 of the suction pad 60 that has been waiting in advance, and is taken out elsewhere. Here, the suction surface 61 of the suction pad 60 is configured as a convex curved surface along the base curve of the contact lens 100, and by applying suction pressure to the suction surface 61 via the air passage 62, the contact lens 100 is It can be sucked and held in a stable state.

  The pressing surface 51 of the press head 50 is configured as a concave spherical surface having a single curvature radius in a range of 20 to 80 mm larger than the curvature radius of the outer surface 12 of the concave mold 10. More preferably, the radius of curvature is set in the range of 25 to 60 mm.

  Incidentally, when the pressing surface 51 of the press head 50 is a flat surface having an infinite radius of curvature, the outer surface 12 of the concave mold 10 and the press head 50 are in point contact with each other, so that the force is excessively concentrated on one point. As a result, there is a high possibility that the contact lens 100 is broken or cracked. Further, when the radius of curvature of the pressing surface 51 is as small as 20 mm or less, the concave mold 10 cannot be sufficiently deformed, and as a result, the contact lens 100 may not spontaneously fall. Further, when the radius of curvature of the pressing surface 51 is 80 mm or more, the deformation speed of the concave mold 10 becomes faster than the speed suitable for the separation of the contact lens 100, and a forced force is applied. The center portion or the peripheral portion of the lens may be stressed and cracks may occur on the lens surface. In either case, it is not preferable, and it is preferably set in the range of 20 to 80 mm.

  When the difference in thickness between the lens center portion and the peripheral portion in the dry state is large (for example, 0.09 mm or more), stress is concentrated on the lens center portion by pressing with the press head 50. There is a case. In such a case, as shown in FIG. 9, a contact lens having a higher quality can be collected by using a perforated press head having a circular hole 52 in the center of the press head 50. preferable. Although it depends on the lens design, it is preferable to use a perforated press head when specifically peeling off a lens of −5.00 D or more.

  There is no limitation on the power of the lens to which the method of the present invention can be applied, and it is possible to deal with any power such as a positive power to a negative power, for example, a range of + 10.00D to -15.00D.

  Moreover, as a kind of surface shape of the base surface 41 of the receiving stand 40 which mounts the concave mold | type 10, what is shown to Fig.8 (a)-(c) is employable, for example. In the cradle 40A, 40B of (a), (b), the pedestal surfaces 41A, 41B on the lower end of the cylindrical peripheral wall 14 of the concave mold 10 are configured with inclined surfaces that are inclined downward from the inner peripheral side toward the outer peripheral side. Yes. In particular, in (a), the gradient of the inclined surface is set to a linear shape, and in (b), the gradient of the inclined surface is set to a concave curve. In the cradle 40C of (c), the pedestal surface 41C is a flat surface.

  When the pedestal surface 41C of the cradle 40C is a flat surface as shown in (c), the centers are properly aligned when the convex outer surface 12 of the concave mold 10 is pressed by the press head 50. The deformation of the inner surface (lens molding surface 11) of the concave mold 10 is stabilized. Further, when the pedestal surfaces 41A and 41B of the cradle 40B are inclined surfaces as in (a) and (b), when the convex outer surface 12 of the concave mold 10 is pressed by the press head 50, the inner surface of the concave mold 10 The (lens molding surface 11) is easily deformed in the direction of increasing the curvature. That is, the deformation can be advantageously advanced.

  In addition, by providing the annular upright wall 42 on the innermost peripheral portion of the pedestal surface 41 (41 </ b> A to 41 </ b> C), it is possible to reliably prevent the lateral displacement of the concave mold 10 placed on the pedestal surface 41.

As described above, when the shape of the pedestal surface 41 of the cradle 40 is appropriately selected from (a) to (c), it is desirable to adjust the pressure applied to the press head 50 according to the selected type. . For example, in the case of mass production specifications, the flat surface type (c) sets the press pressure in the range of 160 to 200 kg, and the inclined surface type is set in the range of 150 to 180 kg smaller than the flat surface type.

  Further, as a method of collecting the contact lens 100 that naturally falls from the circular opening 45 of the cradle 40, in addition to the method of receiving by the suction pad 60 as described above, a collection box is installed under the cradle 40, A method of installing the belt conveyor and receiving it naturally is conceivable. However, in any case, if the depth of the opening of the cradle 40 (corresponding to the thickness of the cradle 40) exceeds 5 mm, the contact lens 100 becomes easy to be divided into inversion and non-inversion, and it becomes impossible to obtain a certain law in the directionality at the time of lens collection.

  Therefore, it is preferable to install a suction pad, a recovery elevator, or the like between the distance of the lens “sag value height” within a depth of 5 mm of the opening (hole cylinder) of the cradle 40 when the lens naturally falls. By doing so, it is possible to collect the lens in a fixed upward direction of the convex surface, and for example, it is possible to collect the lens without being restricted by a transport tray or the like in the next surface modification process or inspection process.

Next, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.
First, an example of manufacturing a contact lens will be described.

<Production Example A: Synthesis of Macromer>
In a three-necked flask, 8.88 g of isophorone diisocyanate, 0.025 g of dibutyltin dilaurate as a catalyst and 45 mL of methylene chloride were placed, and stirred under a nitrogen stream. Next, 20 g of ω-butyl-α- [3- (2,2- (dihydroxymethyl) butoxy) propyl] polydimethylsiloxane was precisely weighed and dropped into the flask over about 3 hours to react.

  After reacting at room temperature for 48 hours, 0.025 g of dibutyltin dilaurate and 23.3 g of polyethylene glycol monomethacrylate (PE-350) were precisely weighed and dropped into the flask over about 30 minutes.

The mixture was covered with aluminum foil and stirred until the absorption band (2260 cm ⁻¹ ) derived from isocyanate disappeared in IR (infrared absorption spectrum) analysis (reaction for about 48 hours at room temperature). Further methylene chloride was added to this solution, followed by washing with a large amount of water, dehydration and filtration, and then the solvent was distilled off to obtain a macromer having a number average molecular weight of 2,000 (polystyrene conversion).

<Production Example A-1: Production of Contact Lens>
About 3.9 g of the siloxane macromonomer obtained in Production Example A, about 15 g of tris (trimethylsiloxy) -γ-methacryloxypropylsilane, about 11.1 g of N, N-dimethylacrylamide, and 1-anilino-4-4 as a colorant About 0.003 g of (4-vinylbenzyl) aminoanthraquinone and about 0.18 g of phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide as a polymerization initiator were stirred at room temperature for about 20 hours to prepare a monomer mixture. . Next, this monomer mixed solution is filled in a contact lens-shaped resin mold made of polypropylene, and an upper mold (convex mold) and a lower mold (concave mold) are assembled, and then an ultraviolet to visible light of about 35 mW / cm ^2. (380 to 450 nm) was irradiated for 20 minutes to complete the polymerization.

<Production Example A-2: Production of contact lens>
About 4.5 g of the siloxane macromonomer obtained in Production Example A, about 15 g of tris (trimethylsiloxy) -γ-methacryloxypropylsilane, about 10.5 g of N, N-dimethylacrylamide, phenylbis (2,4,6- About 0.18 g of trimethylbenzoyl) phosphine oxide was stirred at room temperature for about 20 hours to prepare a monomer mixture. Next, this monomer mixed solution is filled in a contact lens-shaped resin mold made of polypropylene, and an upper mold (convex mold) and a lower mold (lower mold) are assembled, and then an ultraviolet to visible light of about 35 mW / cm ^2. (380 to 450 nm) was irradiated for 20 minutes to complete the polymerization.

<Production Example B-1: Production of contact lens not containing silicone>
About 0.03 g of phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide as a polymerization initiator was added to about 5 g of 2-hydroxyethyl methacrylate, and the mixture was stirred at room temperature for about 20 hours to prepare a monomer mixture. Next, this monomer mixed solution is filled in a contact lens-shaped resin mold made of polypropylene, and an upper mold (convex mold) and a lower mold (concave mold) are assembled, and then an ultraviolet to visible light of about 35 mW / cm ^2. (380 to 450 nm) was irradiated for 20 minutes to complete the polymerization.

<Production Example B-2: Production of contact lens not containing silicone>
About 4.9 g of 2-hydroxyethyl methacrylate, about 0.1 g of methacrylic acid and about 0.03 g of phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide as a polymerization initiator were added and stirred at room temperature for about 20 hours. A monomer mixture was prepared. Next, this monomer mixed solution is filled in a contact lens-shaped resin mold made of polypropylene, and an upper mold (convex mold) and a lower mold (concave mold) are assembled, and then an ultraviolet to visible light of about 35 mW / cm ^2. (380 to 450 nm) was irradiated for 20 minutes to complete the polymerization.

<Example 1>
Fifty resin molds (lens power: −3.00 D) obtained by polymerizing the lenses obtained in Production Example A-1 were prepared, and the uneven resin molds were separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 180 kg using a press head 50 having a concave spherical pressing surface 51 having a curvature radius of 20 mm. As a result, all the lenses spontaneously dropped from the concave mold 10, and the obtained lenses were clean and free from scratches, nicks and cracks.

<Example 2>
Fifty resin molds (lens frequency: −3.00 D) in which the lens obtained in Production Example A-1 was polymerized were prepared, and the uneven resin mold was separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 160 kg using a press head 50 having a concave spherical pressing surface 51 having a curvature radius of 30 mm. As a result, all the lenses spontaneously dropped from the concave mold 10, and the obtained lenses were clean and free from scratches, nicks and cracks.

<Example 3>
Fifty resin molds (lens frequency: -1.00 D) in which the lens obtained in Production Example A-1 was polymerized were prepared, and the uneven resin mold was separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 160 kg using a press head 50 having a concave spherical pressing surface 51 having a curvature radius of 60 mm. As a result, all the lenses spontaneously dropped from the concave mold 10, and the obtained lenses were clean and free from scratches, nicks and cracks.

<Example 4>
50 resin molds in which the lens obtained in Production Example A-2 was polymerized (lens power: −3.00 D) were prepared, and the uneven resin mold was separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 180 kg using a press head 50 having a concave spherical pressing surface 51 having a curvature radius of 80 mm. As a result, all the lenses naturally fell from the concave shape, and the obtained lenses were clean and free from scratches, nicks and cracks.

<Example 5>
Fifty resin molds (lens frequency: −7.00 D) in which the lens obtained in Production Example A-2 was polymerized were prepared, and the uneven resin mold was separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, a pressing load is applied by using the press head 50 having the concave mold 10 placed on the cradle 40 and having the concave spherical spherical pressing surface 51 shown in FIG. 9. Pressed at 170 kg. As a result, all the lenses spontaneously dropped from the concave mold 10, and the obtained lenses were clean and free from scratches, nicks and cracks.

<Example 6>
Fifty resin molds (lens frequency: -5.00 D) in which the lenses obtained in Production Example A-2 were polymerized were prepared, and the uneven resin molds were separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, a pressing load is applied by using the press head 50 having the concave mold 10 placed on the cradle 40 and having the concave spherical spherical pressing surface 51 shown in FIG. 9. Pressed at 150 kg. As a result, all the lenses spontaneously dropped from the concave mold 10, and the obtained lenses were clean and free from scratches, nicks and cracks.

<Comparative Example 1>
Fifty resin molds (lens frequency: −3.00 D) in which the lens obtained in Production Example A-1 was polymerized were prepared, and the uneven resin mold was separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 180 kg using a press head 50 having a concave spherical pressing surface 51 having a curvature radius of 10 mm. However, no change was found in the curvature of the concave mold 10, and no difference in curvature from the lens occurred, so that all 50 lenses were not peeled off from the concave mold 10.

<Comparative example 2>
50 resin molds in which the lens obtained in Production Example A-2 was polymerized (lens power: −3.00 D) were prepared, and the uneven resin mold was separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 180 kg using a press head 50 having a concave spherical pressing surface 51 having a curvature radius of 100 mm. However, the deformation speed of the concave mold 10 became faster than the speed suitable for releasing the lens, and stress was applied to the center part or the peripheral part of the obtained lens, and a crack was generated on the lens surface.

<Comparative Example 3> (When the lens material does not contain silicone)
Fifty resin molds (lens power: −3.00 D) in which the lenses obtained in Production Example B-1 were polymerized were prepared, and the uneven resin molds were separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 180 kg using a press head 50 having a concave spherical pressing surface 51 with a curvature radius of 20 mm. As a result, half of the 25 could be removed, but the remaining 25 could not be recovered because the lens was damaged.

<Comparative Example 4> (When the lens material does not contain silicone)
Fifty resin molds (lens power: −3.00 D) in which the lenses obtained in Production Example B-2 were polymerized were prepared, and the uneven resin molds were separated as shown in FIGS. Of the 50 lenses, all the lenses remained in the concave mold 10, and all of the excess ring-shaped polymer remained in the convex mold 20 and were well separated. Next, as shown in FIG. 4, the concave mold 10 was placed on the cradle 40 and pressed with a press load of 180 kg using a press head 50 having a concave spherical pressing surface 51 with a curvature radius of 20 mm. As a result, half of the 25 could be removed, but the remaining 25 could not be recovered because the lens was damaged.

  As in Comparative Examples 1 and 2, when 10 mm and 100 mm press heads were used, the lens could not be peeled off, or the central part or the peripheral part of the lens was damaged and could not be used as a contact lens. . Further, as in Comparative Examples 3 and 4, when a contact lens material not containing silicone was used, almost half were damaged and could not be recovered.

  On the other hand, when a press head having a curvature in the range of 20 to 80 mm is used as shown in the examples, the lens exhibits good separation from the resin mold, and the separated lens is clean, and further, scratches and scratches are observed. It was a crack-free one. In particular, it showed a remarkable effect on contact lenses containing silicone.

It is a sectional side view for explanation of a cast mold manufacturing method performed as a premise for carrying out the method of the present invention. It is a side view for description of the process of separating the concave mold and the convex mold of the embodiment of the present invention. It is a sectional side view showing the state where the contact lens after polymerization has adhered to the inner surface of the concave mold as a result of separating the concave mold from the convex mold. It is a sectional side view which shows the state which is putting the said recessed mold | die isolate | separated on a receiving stand and is going to press the outer surface of a concave mold with a press head. It is a sectional side view which shows the relationship of the force at the time of pressing a concave convex outer surface with the said press head. FIG. 6 is a side sectional view showing a phenomenon in which the concave mold is deformed and the contact lens naturally falls as a result of pressing the concave outer surface with the press head as shown in FIG. 5. It is a sectional side view for explanation of an operation principle of naturally dropping a contact lens by pressing a concave outer surface with a press head and taking it out from the concave mold. It is principal part sectional drawing which shows the example (a)-(c) of the shape of the base surface of a receiving stand. It is a sectional side view which shows the shape of the press surface of a press head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Concave type 11 Lens molding surface 12 Outer surface which consists of convex spherical surface 13 Peripheral flange 14 Cylindrical peripheral wall 20 Convex 21 Lens molding surface 23 Peripheral flange 31a, 32a Claw 40, 40A, 40B, 40C Receptacle 41, 41A, 41B, 41C Base surface 45 Opening 50 Press head 51 Press surface 60 Suction pad 100 Contact lens

Claims (5)

Using a resin mold comprising a concave mold and a convex mold each having a lens molding surface formed on the inner surface, the concave mold is held with the lens molding surface facing upward, and a liquid raw material containing silicone in the concave mold And the convex mold is fitted into the concave mold from above, and the contact lens is taken out from the resin mold after performing the cast mold manufacturing method in which the raw material is polymerized in the concave mold and the convex mold to produce the contact lens. A method,
(A) a step of separating the concave mold and the convex mold after polymerization so that the contact lens adheres to the concave mold side;
(B) An outer surface having a convex curvature facing upwards on the opposite side to the concave lens molding surface, holding the concave mold with the contact lens attached in an upside down orientation so that the inner lens molding surface faces downward The center part of the lens is pressed downward relative to the peripheral part using a press head, so that the concave lens molding surface is deformed in the direction in which the curvature increases, and the contact lens attached to the inner surface is naturally A step of dropping,
A method of taking out a contact lens from a resin mold. In the step (A), a claw is inserted between a peripheral flange provided on the concave mold and a peripheral flange provided on the convex mold, and the concave peripheral flange and the convex mold are parallel to each other. 2. The method for removing a contact lens from a resin mold according to claim 1, wherein a force is applied to the claw in a direction perpendicular to the peripheral flange.   In the step (B), using a press head having a pressing surface with a single curvature radius in the range of 20 to 80 mm larger than the curvature radius of the outer surface of the concave mold, the central portion of the outer surface of the concave mold is surrounded by the pressing surface. 3. The method of removing a contact lens from a resin mold according to claim 1, wherein the molded contact lens is naturally dropped by pressing downward relative to the portion.   In the step (B), the concave mold to which the contact lens is attached is held in an upside down posture so that the lens molding surface faces downward by placing the lower end of the cylindrical peripheral wall of the concave mold on the cradle. As a pedestal, it has an opening through which the dropped contact lens passes in the center, and the pedestal surface on which the lower end of the cylindrical peripheral wall around the pedestal is a flat surface or an inclined surface inclined downward from the inner peripheral side toward the outer peripheral side The method of taking out the contact lens of any one of Claims 1-3 characterized by using the receiving stand comprised by these.   The contact lens according to any one of claims 1 to 4, further comprising a step of receiving the contact lens naturally dropped in the step (B) using a suction pad and taking it out to another place. To remove the resin from the resin mold.

Images