JP2012200701A - Adhesive coating method for plastic lens molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To coat an injection auxiliary member with an adhesive so that no adhesive enters the injection auxiliary member.SOLUTION: An adhesive coating method includes a support step of supporting an injection auxiliary member 2 bonded to a plastic lens molding die with an adhesion surface 12a of a fitting piece 12 oriented up. The method also includes an adhesive supply step of supplying the adhesive to coating nozzles 21 composed of a pipe, and holding droplets 14a of the adhesive 14 at lower ends of the coating nozzles 21. Further, the method includes a coating step of sticking the droplets 14a onto the adhesion surface 12a. Furthermore, the method includes an adhesive separation step of widening intervals between the fitting piece 12 and the coating nozzles 21 by a predetermined length L1 after the coating step, and stopping the coating nozzles 21 to the fitting piece 12 until threads 31 made by being pulled by the adhesive 14 are broken.

Description

  The present invention relates to an adhesive coating method for a plastic lens mold for applying an adhesive to an injection assisting member that is bonded to a mold for molding a plastic lens.

  Conventional plastic lenses for spectacles are generally formed by cast polymerization. This casting polymerization is a method in which a plastic lens material is injected into a mold and cured by heat or energy such as ultraviolet rays to obtain a molded product. A mold used for cast polymerization is described in Patent Document 1, for example.

  The mold disclosed in Patent Document 1 includes a mold assembly in which a lens molding cavity is formed, and an injection assisting member bonded to the mold assembly. The mold assembly is composed of a pair of disk-shaped mold members that are molds for lens surface molding, and a tape that is wound around the outer periphery of these mold members so as to be a mold for edge surface molding. Yes. The tape has an injection port for injecting a plastic lens material.

  The injection assisting member is for guiding a plastic lens material into the cavity. The injection assisting member includes a cylinder for inserting a nozzle for supplying a plastic lens material, and a plate-like attachment piece integrally formed at one end of the cylinder. The mounting piece is formed in a shape along the outer peripheral surface of the mold assembly. The mounting piece is formed with an opening that communicates the inside and outside of the cylindrical body. The mounting piece is bonded to the outer peripheral surface of the mold assembly with an adhesive tape or an adhesive.

  The opening formed in the mounting piece is positioned at a position facing the inlet of the tape. The nozzle is inserted from an injection assisting member into the injection port of the tape and injects a plastic lens material into the cavity.

  In order to bond the injection assisting member to the mold assembly, an operator first attaches an adhesive tape to the mounting piece of the injection assisting member or applies an adhesive. The adhesive tape has a through hole at a position facing the opening of the mounting piece. The operator holds the injection holding member to which the adhesive tape has been applied or the adhesive has been applied in this way, and presses it against the outer peripheral surface of the mold assembly, whereby the injection auxiliary member is bonded to the mold assembly. The

International Publication WO 2010/098466

  The inventor is considering automating the process of applying the adhesive using the adhesive application device that applies the liquid adhesive to the mounting piece of the injection assisting member described above. However, when the adhesive is applied to the mounting piece with an application nozzle, there arises a problem caused by the characteristics of the adhesive as described later.

  The adhesive has viscosity so as to be held on the adhesive surface of the mounting piece. When this type of adhesive is applied to the mounting piece with an application nozzle and then the application nozzle is separated from the mounting piece, the adhesive pulls the thread. If the yarn is cut from the tip on the nozzle side in a stretched state, the yarn may enter the opening of the attachment piece. When the yarn enters the inside of the injection assisting member, the yarn is mixed into the mold assembly together with the plastic lens material. Thus, the plastic lens mixed with the adhesive becomes a defective product.

  The present invention has been made to solve such problems, and for plastic lens molds capable of applying an adhesive to the injection assisting member so that the adhesive does not enter the injection assisting member. An object is to provide an adhesive application method.

  In order to achieve this object, an adhesive coating method for a plastic lens mold according to the present invention has a mounting piece that is bonded to a peripheral wall of a hollow cylindrical mold that molds a plastic lens, and is attached to the peripheral wall. A supporting step for supporting an injection assisting member formed with a lens material supply hole communicating with an opening of the opening so that the adhesive surface of the mounting piece is directed upward; and an adhesive surface so as to be directed to the adhesive surface An adhesive supply step of supplying an adhesive to a coating nozzle formed of a pipe disposed above and holding a droplet of the adhesive at a lower end of the coating nozzle; and a space between the mounting piece and the coating nozzle is narrowed An application step for adhering the droplets to the adhesive surface, and after the application step, the interval between the attachment piece and the application nozzle is increased by a predetermined length and applied to the attachment piece. And having an adhesive separation step to stop the coating nozzle to the mounting piece to yarn produced expires by stringing of the adhesive when the nozzle is separated.

  The present invention is characterized in that, in the above invention, the predetermined length is set to be shorter than a distance between a position where the adhesive is applied on the mounting piece and the hole.

  According to the present invention, in the above invention, the determination as to whether or not the yarn generated by the threading of the adhesive is broken is performed based on an elapsed time after the application nozzle is stopped with respect to the attachment piece. Features.

  According to the present invention, the yarn generated by the threading of the adhesive is generated in a length that does not enter the injection assisting member, and is cut while the application nozzle is stopped with respect to the mounting piece. Therefore, according to the present invention, it is possible to provide an adhesive coating method for a plastic lens mold that can apply an adhesive to the injection assisting member so that the adhesive does not enter the interior of the injection assisting member. it can.

It is a side view which shows schematic structure of the adhesive agent coating apparatus used in order to implement the adhesive agent coating method for plastic lens molds which concerns on this invention. It is a disassembled perspective view of the shaping | molding die for plastic lenses. FIG. 4A is a cross-sectional view of a plastic lens mold, in which FIG. 1A is a longitudinal cross-sectional view showing the entire mold cut away, and FIG. 2B is an enlarged cross-sectional view of the main part. It is a bottom view of an application nozzle and a holder. It is the VV sectional view taken on the line in FIG. It is the VI-VI sectional view taken on the line in FIG. The side view of the principal part for demonstrating the apply | coating method, The figure (A) shows the state which hold | maintained the droplet of the adhesive agent by the application nozzle, The figure (B) attaches an adhesive agent to an attachment piece. FIG. 3C shows a state where the coating nozzle is raised by a predetermined distance. It is a flowchart for demonstrating the application | coating method.

  Hereinafter, an embodiment of an adhesive coating method for a plastic lens mold according to the present invention will be described in detail with reference to FIGS. First, the configuration of an adhesive application device for carrying out the adhesive application method according to the present invention will be described with reference to FIG.

An adhesive application device 11 shown in FIG. 1 includes a support portion 3 that supports an injection assisting member 2 that is a member to which an adhesive (not shown) is applied, and an application portion 4 that applies an adhesive to the injection assisting member 2. And.
The injection assisting member 2 constitutes a part of the plastic lens mold 5 as shown in FIGS. The plastic lens mold 5 is for molding a plastic lens. As shown in FIGS. 2 and 3A, the plastic lens mold 5 according to this embodiment includes a mold assembly 6 having a hollow cylindrical shape, and the above-described adhesive bonded to the outer peripheral surface of the mold assembly 6. The injection assisting member 2 is used.

The mold assembly 6 includes a pair of disk-shaped mold members (a first mold member 7 and a second mold member 8), and a tape 9 wound around the outer peripheral surfaces of these mold members 7 and 8. It is configured.
In the mold assembly 6, the injection assisting member 2 is bonded after the injection port 10 is formed in the tape 9.

The mold members 7 and 8 are formed in a predetermined shape by a glass material that can transmit light, and constitute a mold for forming a lens surface. In FIG. 3, the lower surface 7a of the first mold member 7 located on the upper side is a concave curved surface that is convex upward, and the upper surface 8a of the other second mold member 8 is convex upward. It is a convex curved surface.
The tape 9 constitutes a mold for forming the edge surface of the lens. The tape 9 is a so-called adhesive tape formed of a material that can transmit light. The tape 9 is wound and pasted around the outer peripheral surfaces of the first and second mold members 7 and 8 at least once.

That is, the peripheral wall of the plastic lens mold 5 is constituted by the tape 9.
The tape 9 covers the entire outer peripheral surface of the first and second mold members 7 and 8. The tape 9 is wound around the first and second mold members 7 and 8 so as not to protrude from the non-use surface of the second mold member 8. The non-use surface is a concave surface opposite to the upper surface 8a in the second mold member 8. The width of the tape 7 can be changed as long as it is a width that seals the gap between the first and second mold members 7 and 8.

  Although not shown, the tape 9 includes a belt-like base material and an adhesive layer formed on one surface of the base material (a surface facing the mold members 7 and 8). Examples of the base material include polyester. The material forming the adhesive layer is preferably one that does not dissolve into the plastic lens material or inhibit the polymerization, and examples thereof include a silicone-based adhesive.

By winding the tape 9 around the pair of mold members 7 and 8, the mold assembly 6 is assembled with the lens forming cavity 11 (see FIG. 3) inside.
The inlet 10 formed in the tape 9 is for injecting a plastic lens material into the cavity 11. The injection port 10 is formed by, for example, a cutter (not shown) on the tape 9 wound around the first and second mold members 7 and 8.

  As shown in FIGS. 2 and 3, the injection assisting member 2 is formed integrally with a mounting piece 12 formed in a shape that can be overlapped with the outer peripheral portion of the mold assembly 6, and the mounting piece 12. And the auxiliary member main body 13. The injection assisting member 2 is made of a plastic material. The mounting piece 12 is formed in a plate shape curved with a curvature along the outer peripheral surface of the mold assembly 6. In the assembled state shown in FIG. 3, the mounting piece 12 is bonded to the mold assembly 6 with an adhesive 14.

  The auxiliary member main body 13 is a cylinder having a quadrangular cross section, and is formed so as to extend from the mounting piece 12 to the side opposite to the mold assembly 6. As shown in FIG. 3, the auxiliary member main body 13 according to this embodiment includes a flat plate portion 13a extending in parallel with the radial direction of the mold assembly 6, and an inclined portion 13b facing the flat plate portion 13a. . The inclined portion 13b is inclined so as to gradually approach the flat plate portion 13a toward the mounting piece 12. A flange 15 is provided at the end of the auxiliary member body 13 opposite to the mounting piece 12.

The inside of the auxiliary member main body 13 becomes a passage 16 through which a molten plastic lens material (not shown) flows. The attachment piece 12 is formed with a slit-like hole 17 (see FIG. 3) serving as an opening at one end of the passage 16. The hole 17 is formed to extend in parallel with the flat plate portion 13a when the mounting piece 12 is viewed from the mold assembly 6 side.
After the injection port 10 is formed in the tape 9, the injection assisting member 2 is bonded to the mold assembly 6 with the hole 17 facing the injection port 10.

As shown in FIG. 1, the support portion 3 of the adhesive application device 1 is configured to support the injection assisting member 2 with the mounting piece 12 exposed. The support part 3 shown in FIG. 1 supports the attachment piece 12 in a state where the adhesive surface 12a of the attachment piece 12 is directed upward.
The application unit 4 of the adhesive application device 1 includes a plurality of application nozzles 21 facing the mounting piece 12, an adhesive supply device 22, and a drive device 23.
Each application nozzle 21 is formed of a pipe as shown in FIGS. These application nozzles 21 are positioned above the mounting piece 12 so as to extend in the vertical direction. The lower end of the application nozzle 21 is opened downward. The distance D between the tip (lower end) of each application nozzle 21 and the adhesive surface 12a (the upper surface in FIG. 1) of the mounting piece 12 is formed uniformly in all the application nozzles 21.

  The adhesive supply device 22 supplies the liquid adhesive 14 to the application nozzle 21. Further, as shown in FIG. 7, the adhesive supply device 22 is configured to maintain a state in which the adhesive 14 is held as droplets 14 a at the tip of the application nozzle 21. The adhesive 14 used in this embodiment is of an ultraviolet curable type and has a predetermined viscosity. The adhesive 14 is not limited to the ultraviolet curable type, and can be changed as appropriate.

As shown in FIGS. 4 to 6, the application nozzle 21 according to this embodiment is supported by a single holder 24, and is supported by the adhesive supply device 22 through the holder 24. The holder 24 includes a box-shaped main body 25 that opens upward, and a lid body 26 that closes the opening of the main body 25.
The lid 26 is attached to the lower end of the adhesive supply device 22. The adhesive passage 22 a of the adhesive supply device 22 opens into an adhesive storage chamber 27 formed inside the holder 24.

  As shown in FIGS. 5 and 6, the application nozzle 21 is attached to the lower wall 25 a so as to penetrate the lower wall 25 a of the main body 25. That is, the adhesive storage chamber 27 is communicated with each application nozzle 21. The volume of the adhesive storage chamber 27 is large enough to store the adhesive 14 in a predetermined amount so that the adhesive 14 supplied to the adhesive storage chamber 27 is distributed to all the application nozzles 21. Is set to

  The length of the application nozzle 21 according to this embodiment is changed in accordance with the horizontal position of each application nozzle 21 because the lower wall 25a is formed to extend in the horizontal direction. That is, the coating nozzle 21 corresponding to the center in the longitudinal direction of the mounting piece 12 is the longest, and the coating nozzle 21 corresponding to both ends in the longitudinal direction of the mounting piece 12 is the shortest. The distance between the tip (lower end) of these application nozzles 21 and the adhesive surface 12a of the mounting piece 12 is formed so as to be equal in all the application nozzles 21 in this embodiment.

  As shown in FIG. 7, these application nozzles 21 are arranged in a rectangular shape when viewed from below. The rectangle formed by arranging these application nozzles 21 is formed in a size that surrounds the hole 17 of the attachment piece 12 when the attachment piece 12 is viewed from above. That is, the plurality of application nozzles 21 are arranged so as to surround the hole 17 when viewed from above.

  The driving device 23 is configured to be able to change the interval between the coating nozzle 21 and the mounting piece 12. The drive device 23 shown in FIG. 1 is configured to move the application nozzle 21 up and down. The droplet 14a of the adhesive 14 held at the tip of the application nozzle 21 by the adhesive supply device 22 adheres to the adhesive surface 12a of the mounting piece 12 when the application nozzle 21 descends from the initial position shown in FIG. To do.

Next, the adhesive application method of the present invention using the adhesive application device 1 will be described with reference to FIGS. 7A to 7C and the flowchart shown in FIG.
The adhesive applicator 1 according to this embodiment performs a preparatory operation before starting the operation of applying the adhesive 14. This preparatory operation is an operation in which the driving device 23 raises the application nozzle 21 and the adhesive supply device 22 to the initial positions shown in FIG. This preparatory operation can be performed immediately after the application of the adhesive 14 is completed.

  In order to apply the adhesive 14, first, in the support step S <b> 1 of the flowchart shown in FIG. 8, the operator or the automatic feeding device supports the injection assisting member 2 on the support portion 3. At this time, when the adhesive passage 22 a and the adhesive storage chamber 27 of the adhesive supply device 22 are not filled with the adhesive 14, the adhesive supply device 22 is operated, and the adhesive 14 is applied to the application nozzle 21. Supply. The adhesive supply device 22 is stopped in a state where the adhesive 14 flows out from all the application nozzles 21.

  Thereafter, the adhesive supply device 22 operates, and a droplet 14a of the adhesive 14 is formed at the lower end of the application nozzle 21, as shown in FIG. In this way, the droplet 14a is formed at the lower end of the application nozzle 21, whereby the adhesive supply step S2 of the flowchart shown in FIG. 8 is completed.

  Next, in the application step S3 of the flowchart shown in FIG. 8, the driving device 23 lowers the adhesive supply device 22 and the application nozzle 21 to the lowered position. As shown in FIG. 7 (B), the lowered position in this embodiment refers to the application nozzle 21 and adhesion when the droplet 14a of the adhesive 14 adheres to the upper surface (adhesion surface 12a) of the mounting piece 12. This is the vertical position of the agent supply device 22.

That is, by performing the application step S <b> 3, the droplet 14 a of the adhesive 14 adheres to the adhesive surface 12 a of the mounting piece 12. The adhesive 14 is applied to a position surrounding the hole 17 of the attachment piece 12 by a plurality of application nozzles 21 in a so-called stamp type.
After the adhesive 14 adheres to the mounting piece 12, the drive device 23 performs an operation of separating the adhesive 14 from the application nozzle 21 in the adhesive separation step S <b> 4 of the flowchart shown in FIG. 8.

When the application nozzle 21 rises in a state where the lower end of the application nozzle 21 is connected to the attachment piece 12 via the adhesive 14, the adhesive 14 extends upward by pulling the thread. After the yarn is stretched, the viscosity decreases and the yarn breaks. If the long stretched yarn breaks at the upper end (connection portion with the application nozzle 21) and falls down, the thread 17 may enter the hole 17 of the mounting piece 12.
In order to prevent the yarn made of the adhesive 14 from entering the hole 17 as described above, the driving device 23 first sets the coating nozzle 21 and the adhesive supply device 22 to the yarn as shown in FIG. Is increased by a length L1 that is short enough to extend.

In this ascending stroke, a thread 31 made of the adhesive 14 having a length corresponding to the length L1 is formed. The length L1 is set to be shorter than the distance L2 (see FIG. 4) between the position where the adhesive 14 is applied on the mounting piece 12 and the hole 17. For this reason, even if the thread 31 having the length L1 is cut at the upper end and falls down, the thread 31 does not enter the hole 17.
The driving device 23 stops the application nozzle 21 and the adhesive supply device 22 until the yarn 31 is broken because the viscosity of the yarn 31 is lost after the ascent process.
The timing at which the thread 31 is cut also depends on the length of the thread 31 when the adhesive 14 is stretched and the liquid viscosity of the adhesive 14 itself. For this reason, the stop time of the adhesive supply device 22 is appropriately set in consideration of the length of the yarn 31 and the liquid viscosity of the adhesive 14.

The determination as to whether or not the yarn 31 has been broken is made based on the elapsed time after ascent. That is, the drive device 23 stands by until the time necessary for the yarn 31 to break after the first ascending stroke is completed. When this standby operation ends, the adhesive separation step S4 ends.
After the yarn 31 is broken, the drive device 23 raises the application nozzle 21 and the adhesive supply device 22 to the initial positions shown in FIG. 1 in the return step S5 of the flowchart shown in FIG.

  As described above, the injection assisting member 2 to which the adhesive 14 is applied is taken out from the support 3 by an injection assisting member transfer device (not shown) or an operator and sent to the next step. The injection assisting member 2 is adhered to a predetermined position of the mold assembly 6 in the next step.

  According to the adhesive application method according to this embodiment, the thread 31 generated by the threading of the adhesive 14 is generated in a length that does not enter the injection assisting member 2, and the application nozzle is applied to the mounting piece 12. It cuts while 21 is stopped. Therefore, according to this embodiment, the adhesive application for the plastic lens mold that can apply the adhesive 14 to the injection assisting member 2 so that the adhesive 14 does not enter the interior of the injection assisting member 2 is performed. A method can be provided.

  In this embodiment, the determination as to whether or not the thread 31 generated by the threading of the adhesive 14 has been broken is made based on the elapsed time after the application nozzle 21 is stopped with respect to the mounting piece 12. Yes. For this reason, in making the determination, it is only necessary to stop the apparatus for the time during which the yarn 31 is cut, so that the determination can be made at a low cost.

  DESCRIPTION OF SYMBOLS 1 ... Adhesive coating device, 2 ... Injection | pouring auxiliary member, 5 ... Plastic lens shaping | molding die, 6 ... Mold assembly, 9 ... Tape, 12 ... Mounting piece, 14a ... Droplet, 17 ... Hole, 21 ... Application | coating nozzle, 22 ... adhesive supply device, 24 ... holder, 31 ... thread.

Claims (3)

The injection auxiliary member having an attachment piece bonded to a peripheral wall of a hollow cylindrical mold for molding a plastic lens and having a hole for supplying a lens material communicating with an injection port opened in the peripheral wall A support step for supporting the adhesive surface of the piece so as to face upward;
An adhesive supply step of supplying an adhesive to an application nozzle composed of a pipe disposed above the adhesive surface so as to be directed to the adhesive surface, and holding a droplet of the adhesive at a lower end of the application nozzle;
An application step of narrowing the interval between the mounting piece and the application nozzle to adhere the droplets to the adhesive surface;
After the application step, the distance between the attachment piece and the application nozzle is increased by a predetermined length, and attachment is performed until the yarn generated by threading of the adhesive when the application nozzle is separated from the attachment piece is cut. An adhesive coating method for a plastic lens mold, comprising: an adhesive separating step for stopping the coating nozzle with respect to the piece.   The method for applying an adhesive for a plastic lens mold according to claim 1, wherein the predetermined length is set to be shorter than a distance between the position where the adhesive is applied to the mounting piece and the hole. A method for applying an adhesive for a plastic lens mold.   3. The method for applying an adhesive for a plastic lens mold according to claim 1 or 2, wherein the determination of whether or not the yarn generated by the threading of the adhesive has broken is made by stopping the application nozzle with respect to the mounting piece. An adhesive coating method for a plastic lens mold, which is performed based on the elapsed time after the treatment.

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