JPH0585611U - Mold for plastic lens polymerization - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] In a plastic lens polymerization mold composed of a pair of molds and an annular gasket, the annular gasket can be shared and the mold release from the molded plastic lens is improved. To get a good mold. [Structure] A pair of molds (11,
12) a pair of cylindrical portions that are fitted and positioned from opposite sides, an annular protruding portion 13C located between the pair of cylindrical portions and having a smaller diameter than the cylindrical portions, and the annular protruding portion 13
The common mold receiving surfaces (14, 15) formed on the upper and lower end surfaces of C are provided, and the annular gasket 1 is provided in each of the pair of molds.
A common contact surface for contacting the common mold receiving surface (14, 15) of No. 3 is formed, and at least one mold is not in contact with the inner peripheral surface (13d) of the inner peripheral portion of the annular protrusion 13C. Mold for plastic lens polymerization that has a small-diameter intrusion part that enters in a state.

Description

[Detailed description of the device]

[0001]

【Technical field】

 The present invention relates to a mold used when polymerizing a plastic lens.

[0002]

[Prior art and its problems]

 A mold in which a pair of molds made of glass or ceramics are held at a predetermined interval by an annular gasket is used for polymerization molding of plastic lenses. By filling a plastic monomer in this mold and polymerizing by heating, a plastic lens having a required shape can be obtained.

Conventionally, an annular gasket is provided with a tubular portion into which a mold is fitted, at both ends thereof, and an annular protrusion having a diameter smaller than that of the tubular portion is provided at an intermediate portion. The upper and lower end surfaces of the annular protrusion, that is, the peripheral edges of the bottoms of both tubular portions, constitute a casting die receiving surface having the same curvature radius as that of the casting mold. However, according to this annular gasket, the curvature of the mold receiving surface differs depending on the lens shape, so that a gasket of the type appropriate for the lens is required. For this reason, there is a problem in that the number of types becomes extremely large and the manufacturing and management become very complicated.

To solve this problem, Japanese Examined Patent Publication No. 57-49379 discloses that the upper and lower mold receiving surfaces of the annular protrusion of the annular gasket are made flat, and the mold is also in contact with this receiving surface. The flat portion and the fitting portion that fits into the annular protrusion are provided. According to this structure, the shape of the annular gasket can be standardized, and manufacturing and management are easy.

However, in this annular gasket, a small amount of monomer flows into the gap between the inner periphery of the annular protruding portion and the fitting portion of the mold, and this monomer polymerizes and becomes an adhesive state to both of them, so that when releasing from the mold. However, there was a new problem that it became difficult to release the mold.

[0006]

[The purpose of the device]

 The present invention aims to further improve the releasability at the end of polymerization in the annular gasket proposed in Japanese Patent Publication No. 57-49379 based on the discovery of this new problem.

[0007]

[Outline of the device]

 The present invention relates to a plastic lens polymerization mold comprising a pair of molds and an annular gasket that sets a space between the pair of molds and forms a polymerization molding space for the plastic lens together with the molds. , A pair of tubular parts for fitting and positioning a pair of molds from the opposite sides, an annular projection portion having a smaller diameter than the tubular parts, which is located between the pair of tubular parts, A common mold receiving surface formed on the upper and lower end surfaces of the protruding portion is provided, and a common contact surface for contacting the common mold receiving surface of this annular gasket is formed on each of the pair of molds, and at least one of the molds In addition, it is characterized in that a small-diameter intrusion portion is formed in the inner peripheral portion of the annular protrusion so as to enter without contacting the inner peripheral surface.

According to this configuration, the pair of molds and the annular gasket can be positioned in the radial direction by the fitting relationship between the tubular portions at both ends of the annular gasket and the pair of molds. The annular gasket can be shared by the surface and the common contact surface. On the other hand, the small-diameter intrusion part that enters the inner periphery of the annular protrusion of the annular gasket forms a wedge-shaped space with the inner peripheral surface, so that even if the monomer that infiltrates into this is a polymer, a wedge-shaped protrusion is formed. Therefore, the mold release does not become difficult. The common contact surface of the mold may be, for example, a flat surface substantially orthogonal to the axial direction of the annular gasket.

Further, the common mold receiving surface of the annular gasket can be, for example, the same planar shape. In addition, the inner peripheral edge is formed to have a high cross-sectional chevron shape, or a serrated cross-section with a plurality of chevron-shaped linear contact portions to close the contact surface pressure between the common contact surface of the mold and the mold receiving surface. It is possible to more reliably prevent the leakage of the monomer for polymerization by increasing the height to a linear shape. Further, if the small-diameter introductory part of the mold forms a space having a wedge-shaped cross section with the annular projection inner peripheral surface of the annular gasket, the mold release becomes easier.

[0010]

[Example of device]

 The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a sectional view of a plastic lens molding mold 10 according to the present invention. The mold 10 is composed of a pair of flat circular glass molds 11 and 12 and an annular gasket 13 that holds the glass molds 11 and 12 at a predetermined interval.

The annular gasket 13 has a large-diameter cylindrical portion 13a into which the upper glass mold 11 in the figure is fitted and a large-diameter cylindrical portion 13b into which the lower glass mold 12 is fitted, at both ends thereof. However, between the large-diameter cylindrical portions 13a, 13b 13a, 13b, an annular protrusion 13c having a smaller diameter than these is provided. The upper and lower end surfaces of the large-diameter cylindrical portion 13b constitute common mold receiving surfaces 14 and 15 which are planes orthogonal to the axis O of the annular gasket 13.

A common contact surface 11 a that contacts the common mold receiving surface 14 is formed on the lower surface edge of the glass mold 11 of the concave type (forming a convex surface on the molded plastic lens) in the figure. The common contact surface 11a, like the common mold receiving surface 14, is a flat surface orthogonal to the axis O 2.

On the other hand, a common abutment surface 12 a that comes into contact with the common mold receiving surface 15 is formed on the peripheral edge of the upper surface of the glass mold 12 that is a convex surface type (a concave surface is formed on the molded plastic lens). A small-diameter inflow portion 12b is formed continuously with the inner peripheral end portion of the contact surface 12a, and enters the inner peripheral surface 13d of the annular protrusion 13c in a non-contact state. The small diameter entrance portion 12b forms a wedge-shaped space 16 between itself and the inner peripheral surface 13d.

The glass mold 11 is not formed with a small-diameter intrusion part corresponding to the small-diameter intrusion part 12b, because the glass mold 11 is a concave type. If the glass mold 11 is a convex type, a small-diameter intrusion part is formed, as in the glass mold 12. That is, in the convex surface type, when the common contact surface 12a is formed, it is indispensable to form a small diameter entrance portion that enters the inner peripheral surface 13d, but in the present invention, the small diameter entrance portion 12b is One of the features is that it has a shape that does not contact the inner peripheral surface 13d. If the small diameter entrance portion 12b does not contact the inner peripheral surface 13d, the glass mold 12 cannot be positioned in the radial direction depending on the small diameter entrance portion 12b. To compensate for this, the radial positioning of the glass casting mold 12 is performed by the fitting relationship between the glass casting mold 12 and the large-diameter cylindrical portion 13b.

The common contact surfaces 11a and 12a and the small-diameter indented portion 12b are formed by grinding and removing a part of the mold surfaces Q and R as molds, and these have different shapes. It is commonly formed on many glass molds 11 and 12 having mold surfaces Q and R. Therefore, the annular gasket 13 can be commonly used for many kinds of glass molds 11 and 12.

In the main mold 10 having the above-mentioned configuration, the glass mold 11 and the large-diameter cylindrical portion 13a of the annular gasket 13 are fitted to each other to position them in the radial direction. Similarly, the glass mold 12 and the large-diameter cylindrical portion 13a are similarly positioned. The fitting of 13b positions the two in the radial direction. The distance between the glass molds 11 and 12 is determined by the contact position between the common contact surface 11a and the common mold receiving surface 14 and the contact position between the common contact surface 12a and the common contact surface 15. At this time, the small diameter entry portion 12b of the glass mold 12 enters the inner peripheral surface 13d of the annular protrusion 13c of the annular gasket 13, but is not in contact with the inner peripheral surface 13d.

The mold space 17 formed by the glass molds 11 and 12 and the annular gasket 13 described above is filled with a pre-measured plastic monomer and heat-polymerized. The molded plastic lens is removed by removing the annular gasket 13 from the glass molds 11 and 12, and at the same time, at the periphery of the molding lens, a wedge-shaped portion corresponding to the shape of the wedge-shaped space 16 is formed. As a result, the mold release is facilitated. That is, when the glass mold 12 is heated and polymerized in a state in which the glass mold 12 is closely fitted to the inner surface of the inner surface 13d of the annular gasket 13, a small amount of the monomer wrapping around in the space of the fitting portion is polymerized and integrated with the molded lens. Therefore, it becomes difficult to release the glass mold. On the other hand, if a space is positively formed by the small-diameter indented portion 12b and the inner peripheral surface 13d, the monomer that has penetrated into the space is Since it is a large projection that is integrated, mold release becomes easy. In particular, when the space has a wedge-shaped cross section as in the illustrated example, a draft can be obtained, which facilitates mold release.

As described above, even if there is a gap between the small-diameter inlet portion 12b and the inner peripheral surface 13d, the glass mold 12 and the annular gasket 13 are positioned in the radial direction by the glass mold 12 and the large-diameter cylinder. Since it is made by the fitting relationship with the shape portion 13b, the problem of positioning in the radial direction does not occur. Further, the common contact surface 11a of the glass mold 11, and the common contact surface 12a and the small-diameter indented portion 12b of the glass casting mold 12 can be common to many kinds of glass molds 11 and 12. The annular gasket 13 having the receiving surfaces 14 and 15 may have a common shape.

2 and 3 show another embodiment of the present invention. These examples show other examples of the shapes of the common mold receiving surfaces 14 and 15 of the annular gasket 13, and are the same as the first embodiment except for the shapes of the common mold receiving surfaces 14 and 15. Is.

The embodiment shown in FIG. 2 is an example in which the common mold receiving surfaces 14A and 15A of the annular gasket 13A are formed in a mountain shape whose inner peripheral end is high. That is, chevron-shaped contact portions 14a and 15a are formed at the inner peripheral end portions of the common mold receiving surfaces 14A and 15A.

In the embodiment shown in FIG. 3, the common mold receiving surface 14B of the annular gasket 13B is composed of a contact portion 19 having a serrated cross section having a plurality of chevron-shaped linear contact portions 18 continuously. The surface 15B is composed of the trapezoidal cross-section contact portion 20 having a narrow flat portion.

According to these embodiments, when the mold closing force P is applied between the glass molds 11 and 12 by a clip or the like (not shown), the chevron contact parts 14a, 15a or the linear contact parts 18 are common. Since it comes into contact with the contact surface 11a or 12a with a high contact surface pressure and is elastically deformed, it is possible to more reliably prevent the monomer from leaking. Of course, the elastic deformation allowance (shrinkage allowance) is calculated in advance. As described above, the common mold receiving surfaces 14 (14A, 14B) and 15 (15A, 15B) formed on the annular gasket 13 (13A, 13B) have flexibility.

[0023]

[Effect of the device]

 As described above, according to the plastic lens polymerization mold of the present invention, while sharing the annular gasket, it is possible to form the molded plastic without sacrificing the radial positional accuracy between the annular gasket and the pair of molds. The releasability from the lens can be improved.

[Brief description of drawings]

1 is a cross-sectional view showing an embodiment of a plastic lens polymerization mold of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a sectional view showing still another embodiment of the present invention.

[Explanation of symbols]

 10 mold 11 12 glass mold 11a 12a common contact surface 13 13A 13B annular gasket 13a 13b large diameter cylindrical portion 13c annular protrusion 13d inner peripheral surface 14 15 14A 15B common mold receiving surface 14a 15a chevron contact portion 18 linear contact portion 19 Serrated contact

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Morio Takamizawa 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Inside Asahi Kogaku Kogyo Co., Ltd.

Claims (7)

[Scope of utility model registration request] 1. A plastic lens polymerization mold comprising a pair of molds and an annular gasket that sets a space between the pair of molds and forms a polymerization molding space for the plastic lens together with the molds. A pair of cylindrical parts for fitting and positioning the pair of molds from opposite sides; an annular protruding part located between the pair of cylindrical parts and having a diameter smaller than the cylindrical parts; And a common mold receiving surface formed on the upper and lower end surfaces of each of the pair of molds, and a common contact surface that contacts the common mold receiving surface of the annular gasket, and at least one of the molds. A plastic lens polymerization mold characterized in that a small-diameter intrusion portion is formed in an inner peripheral portion of the annular protruding portion so as to enter without contacting the inner peripheral surface. 2. The mold according to claim 1, wherein the one mold is
Mold for plastic lens polymerization, which is a convex type that forms a concave surface on a plastic lens. 3. The plastic lens polymerization mold according to claim 1 or 2, wherein the common contact surface of the mold is flat in a direction substantially orthogonal to the axis of the annular gasket. 4. The plastic lens polymerization mold according to claim 1, wherein the common mold receiving surface of the annular gasket is flat in a direction substantially orthogonal to its axis. 5. The plastic lens polymerization mold according to claim 1, wherein the common mold receiving surface of the annular gasket has a mountain-shaped cross section with a high inner peripheral end. 6. The plastic lens polymerization mold according to claim 1, wherein the common mold receiving surface of the annular gasket has a serrated cross section having a plurality of chevron-shaped linear contact portions. 7. The plastic lens polymerization mold according to claim 1, wherein a small-diameter portion of the mold which forms a space having a wedge-shaped cross section is formed between the small diameter portion of the mold and the inner peripheral surface of the annular protrusion of the annular gasket. .