JP4458837B2 - Marking method for glass mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a marking method capable of easily forming a plurality of kinds of marks having differences in shading onto a forming surface of a glass mold forming die. <P>SOLUTION: The marking process includes: a masking process of forming, by using a coating application wax, a mask having window portions corresponding to the shapes of the respective marks on the forming surface of the glass mold forming die; an etching process of forming a plurality of kinds of recessed parts having various depths and constituting the respective marks by subjecting the forming surface of the glass mold forming die to etching treatment through the mask; and a mask removing process of removing the mask. In the etching process, the plurality of kinds of recessed parts having various depths and constituting the respective marks are formed by bringing etchants of different concentrations into contact with the forming surface for the same period of time through the window portions corresponding to the respective marks of the mask. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention uses a marking method for forming a predetermined mark on a molding surface of a glass mold for a spectacle lens, a glass mold obtained by carrying out the method, and the glass mold It is related with the spectacles lens shape | molded in this way.

  Generally, plastic spectacle lenses are made by molding. In the molding of plastic spectacle lenses, first, glass molds having lens surface-shaped molding surfaces are set above and below an annular gasket to create a space for molding spectacle lenses. Then, a plastic spectacle lens is molded by injecting a plastic monomer into a space formed between the upper and lower glass mold molds and curing it by polymerization. After molding, an external force is applied to the glass mold, and the cured molded product is peeled off to obtain a spectacle lens. In this case, the glass mold is usually used repeatedly to mold a plastic spectacle lens.

  By the way, on the spectacle lens, in order to identify the company's products and other companies' products, and to display information such as model number, standard, specific position instructions, etc., a desired identification mark or hidden mark is appropriately set. Granting is performed as necessary. For example, in a progressive-power spectacle lens, a hidden mark is provided as a reference for alignment with a lens shape such as a spectacle frame, and an identification mark is provided along the outer periphery of the lens. ing.

  Here, when a hidden mark is given to a spectacle lens, the hidden mark is required to be as inconspicuous as possible due to the nature of the product. Therefore, in general, it is not possible to recognize with the naked eye, but is given so that it can be recognized as needed (for example, by observing from a specific angle). As a method of providing such an identification mark and / or a hidden mark, there is a method of directly applying a mark on the surface of a plastic spectacle lens when the item to be produced is a wide variety and a small lot. In addition, when an arbitrary item is produced in a large quantity and efficiently, a method of transferring a mark to a spectacle lens after applying a mark on the surface of the glass mold is often employed. The present invention corresponds to a technique related to a method of transferring a mark to a spectacle lens after providing a mark on the surface of a glass mold for the purpose of the latter mass production.

  Conventionally, as a method of marking on a glass-based material surface, a method of destroying the vicinity of the surface using a laser beam and a method of an etching method using a hydrogen fluoride solution are generally known. As for the technology related to the present invention, for example, there are methods described in the following patent documents.

  In Patent Document 1, a laser beam is focused near the surface of a plastic optical component surface-treated with a hard coat film and / or an antireflection film, so that the vicinity of the surface is destroyed (melted or altered) to form a mark. A laser marking method is disclosed.

  Patent Document 2 discloses a processing method in which etching using hydrogen fluoride is performed after a pattern composed of a gold thin film layer and a paraffin layer is formed on an etching surface of a glass-based material.

  Patent Document 3 discloses a method for producing a glass intaglio having a small etching depth variation and a flat cross-sectional shape using a hydrofluoric acid mixed solution.

JP-A-6-191159 Japanese Patent Laid-Open No. 5-832 Japanese Patent Laid-Open No. 7-9652

  However, in the marking method for marking using laser light as disclosed in Patent Document 1, as shown in FIG. 8, when the substrate is a glass-based material, the concave shape of the molding surface 13 is formed. In the vicinity of the mark boundary of the groove 14, a strained layer 16 and a burr 15 are generated due to the heat of the laser beam, and burrs and cracks are generated starting from this, and the mark cannot be stably transferred for a long period of time. There has been a problem that the performance as a glass mold is remarkably lowered and the life thereof is shortened. Further, in the marking method by etching as disclosed in Patent Document 2 and Patent Document 3, a plurality of types of marks having different visual effects in the same plane (specifically, marks having a difference in shading in appearance) ) Was never thought of.

  The present invention has been made in view of the above points, and marks such as an identification mark and a hidden mark are applied to a glass mold mold that repeatedly applies an external force to deform and peel off in order to mold a spectacle lens. We found that it is useful to use an etching treatment with a hydrogen fluoride solution (etching solution) in the marking method that gives the appearance, and formed multiple types of marks with different visual effects without causing burrs and cracks. Marking method that can be easily formed on the same surface of a mold, a long-life glass mold mold capable of stably transferring a mark shape for a long period of time, and a spectacle lens molded using the mold The purpose is to provide.

  In the present invention, the appearance of the mark on the molding surface of the glass mold is dependent on the depth of the concave portion constituting the mark, and the etching is performed using the visual effect that the deeper concave portion is darker and the shallower concave portion appears lighter. The depth of the recess generated by the treatment is determined by controlling the concentration of the hydrogen fluoride solution and the reaction time as parameters.

The first means is a marking method for providing a plurality of types of marks having different depths on a molding surface of a glass mold for molding a spectacle lens, and the molding surface of the glass mold A masking process for forming a mask with a coating wax having a window corresponding to the shape of each mark, and a depth at which each mark is formed by performing an etching process on the molding surface of the glass mold mold through the mask An etching step of forming a plurality of types of recesses, and a mask removal step of removing the mask,
In the etching step, etching solutions having different concentrations are brought into contact with the molding surface for the same time through windows corresponding to the marks of the mask, or etching with the same concentration is performed through the windows corresponding to the marks of the mask. A plurality of types of recesses having different depths constituting each mark are formed by bringing the liquid into contact with the molding surface for different times .

The marking method on the glass mold mold according to the second means corresponds to the shape of the mark after applying a protective wax on the molding surface of the glass mold mold in the masking step in the first means . By removing the wax in the portion, the window corresponding to the shape of each mark is formed.

The marking method on the glass mold mold according to the third means is that, in the second means , when the protective wax is applied to the molding surface of the glass mold mold, the temperature is substantially equal to the melting point of the wax. The wax is applied in a state where the glass mold is heated.

According to a fourth method of the marking method on the glass mold , in any one of the first to third means , the mark is an identification mark and a hidden mark of the glass mold, or one of them. It is characterized by being.

The glass mold forming method according to the fifth means is characterized in that, in the fourth means , the depth of the recess when the hidden mark is formed is 0.6 μm to 1.0 μm.

  According to the marking method of the present invention, a plurality of types of recesses having different depths are formed on the molding surface of a glass mold by an etching method, so that marks having different contrasts with different visual effects, for example, marks that appear dark A (identification mark) and a faintly visible mark (hidden mark) can be easily given in a series of steps. Therefore, since the etching method is different from the physical mark generation method in which pressure is applied or heated, burrs are not generated in the mark, the edge portion is smooth, and the shape recognition rate is improved. In addition, since there is no distortion inside the glass, which is a cause of burrs and chips, there is an effect that the life of the glass mold is increased. In addition, since wax is used as a masking member, it is easy to handle, can be reused by repeating melting and coagulation many times, and it is useful from a cost and environmental standpoint. is there.

  In particular, when etching recesses of different depths, when using a method in which etching solutions of different concentrations are brought into contact with the molding surface through the mask window for the same time, the etching process can be completed in the same time. Easy. Further, when the method of bringing the etching solution of the same concentration into contact with the molding surface through the window portion of the mask for a different time, it is not necessary to prepare the etching solution of different concentration, and preparation is easy.

  Also, when performing the masking process, after applying wax on the molding surface and removing the wax corresponding to the shape of the mark to form the window, the wax is shaved off to the shape of the mark after applying the wax. Therefore, it is possible to easily work by using an NC stamping device or the like. In addition, when the wax is applied in a state where the glass mold is heated to a temperature substantially equal to the melting point of the wax, the wax can be applied thinly, smoothly and easily.

  In addition, by using a glass mold with a mark provided by the marking method of the present invention, an identification mark displaying information such as identification, model number, standard, specific position indication, etc. having a difference in shading on the same molding surface It is possible to easily and stably manufacture a spectacle lens with a hidden mark.

Embodiments of the present invention will be described below.
The mark such as the identification mark or the hidden mark is assumed to be a mark formed of a curved line or a straight line having a concave groove width of about 0.3 mm, or a pattern mark such as a circle or square. The identification mark is a mark for displaying information such as model number and standard in order to distinguish between the company's product and the other company's product, and is often attached along the outer periphery of the lens and is relatively easily visible. It is a mark that can be. There are two types of hidden marks: those that give indication information for specific positions and those that give identification information, and are often given inside the lens. Usually, they cannot be recognized with the naked eye and can be recognized as needed. It is a mark made like this.

  1 is a process diagram of the marking method of the embodiment, FIG. 2 is a diagram showing an example of an identification mark and a hidden mark made by the marking method, and FIG. 3 is a diagram showing a reference line of the glass mold before the marking is performed. 4 is a plan view showing a holder jig for holding a glass mold, FIG. 5 is a cross-sectional view showing a state in which the glass mold is mounted and fixed on the holder jig and stamped by an NC stamping apparatus, FIG. Fig. 7 is a characteristic diagram showing the relationship between the concentration of hydrogen fluoride solution and the reaction time and the depth of the recess when the recess is etched by contacting the glass material with a hydrogen fluoride solution (etching solution). It is sectional drawing of the part which gave this marking method.

  FIG. 6 shows the relationship between the concentration of the hydrogen fluoride solution and the reaction time measured in a room temperature and humidity (for example, 23 ° C., 50%) and the depth of the concave portion (concave groove-shaped mark) formed on the glass surface. From this characteristic diagram, it can be seen that a deep groove can be formed at a specific reaction time as the concentration of the hydrogen fluoride solution is high, and a deep groove can be formed almost in proportion to the reaction time. The marking method of the present invention uses this relationship to form a plurality of types of recesses with different depths on the molding surface of the glass mold, and the recesses constitute an identification mark and a hidden mark having a difference in shading. To do.

  In the marking method according to the first embodiment, first, the depth of each recess according to two types of marks (recognition mark and hidden mark) is preset on the same molding surface of the glass mold, and the depth of the recess. The concentration of two types of hydrogen fluoride solutions and the reaction time for obtaining the same in the same reaction time are determined by basic experiments.

  Then, as a series of steps for marking, first, a masking step is performed. In the masking step, first, the glass mold is heated to a temperature slightly lower than the melting point of the wax to be used. This is to prevent the liquid wax from solidifying immediately, so that the wax can be applied to a uniform thickness. In such a heated state, a wax that has been heated to a liquid state is applied with a brush or the like so that bubbles, unevenness, and gaps are not formed on the surface of the glass mold forming side on which the mark is applied ( Wax application process). And let it stand and let it solidify naturally. This wax is used to protect the portion other than the mark generating portion on the surface of the mold from the etching process using the hydrogen fluoride solution used in the next step.

  Next, in the marking step, the wax applied to the molding surface of the glass mold is peeled into the shape of the mark with an NC (numerical control) marking device, thereby forming an etching window. As a result, the mask made of the applied wax is formed on the molding surface of the glass mold. Here, the NC marking device stores information on the shape, size, reference position, etc. of the recognition mark and hidden mark determined for each item of various spectacle lenses, and the operator selects the spectacle lens item. To determine the recognition mark and / or the hidden mark.

  FIG. 5 shows a specific example of the marking process. As shown in this figure, in the marking process, the tip of the sharp marking pin 12 having a spherical tip shape of about 0.15R is formed with a uniform force from a direction perpendicular to the reference plane 10 of the holder jig 6. 1 is pressed against the molding surface 1 and in that state, the marking pin 12 is moved to the position indicated by 12 'by NC control to remove the wax 11 applied to the glass mold 1 and mark (actually At this stage, the window portion 11A) corresponding to the mark shape is formed. The mark projected on the plane can be stamped regardless of the surface shape of the glass mold 1. In addition, since the contrast of the mark (difference that looks darker or lighter) is determined in the subsequent hydrogen fluoride solution treatment step, the stamping pin is simply pressed here.

  Next, in the etching step, a hydrogen fluoride solution adjusted to the concentration for forming the identification mark and a hydrogen fluoride solution adjusted to the concentration for forming the hidden mark are prepared, and the hydrogen fluoride solution of each concentration is prepared. The identification mark portion (window portion) and the hidden mark portion (window portion) are applied from above the mask (wax). At the same time, time measurement starts. After a predetermined time, the next step is washed to complete the reaction. Thereafter, the wax is melted and removed to obtain a glass mold with a mark by the recess.

  Thus, a plurality of concave portions (concave grooves) are formed by applying a plurality of hydrogen fluoride solutions of a predetermined concentration to the engraved portion (window portion) of the glass mold and reacting for the same predetermined time. ). Thereby, for example, an identification mark that looks dark as shown in FIG. 2 and a hidden mark that looks pale can be applied to the glass mold.

  The glass used for the mold is not particularly limited, but optical glass such as crown glass is preferable. The kind of wax to be used is not particularly limited as long as, for example, paraffin wax or beeswax is preferable, and its melting point is 40 ° C to 70 ° C. Wax is used as a masking material because it has the property that it melts and liquefies when heated and solidifies when cooled, and it can be easily deformed by temperature control as a usage condition. It is highly moisture-proof and waterproof, is easily decomposed by microorganisms, is environmentally friendly and hygienic, and is easy to handle.

  Further, depending on the type of glass used in the mold and the type of wax used, the relationship between the hydrogen fluoride solution concentration and reaction time and the depth of the recess may not match the characteristics shown in FIG. However, in that case, new conditions may be set by conducting a basic experiment. When a wax having a melting point different from the above is used, the temperature at which the glass mold is heated in the masking step needs to be appropriately changed according to the melting point of the wax. When obtaining new conditions, the reaction time is preferably 25 to 30 seconds in consideration of work efficiency, and a hydrogen fluoride solution having a concentration such that a desired recess depth can be obtained with the reaction time. Is preferably set.

  A general spectacle lens has a meniscus shape, but according to the marking method of the present invention, a mark can be formed on either the convex surface or the concave surface of the meniscus spectacle lens. When the mark is formed on the convex surface side of the spectacle lens, the concave mark may be formed on the concave glass mold for molding the convex surface side of the spectacle lens. Further, when forming a mark on the concave side of the spectacle lens, the mark formed by the concave portion may be formed on a convex glass mold for molding the concave side of the spectacle lens.

  In this embodiment, optical glass that is also used as a material for spectacle lenses is used as the material for the glass mold. This is because the finish of the molding surface as a mold is good and the durability is excellent. The wax used is beeswax, and its melting point is about 58 ° C.

The following is a case where a mark is provided on the convex side of a plastic spectacle lens, and the glass mold for use has a concave shape. FIG. 1 shows a process of applying a character and / or mark consisting of a recess to the molding surface of a concave glass mold, and will be described in the order of the processes (1) to (12).
In general, (1) and (2) are preparation steps, (3) to (7) are masking steps, (3) and (4) are wax coating steps, and (5) , (6), (7) are marking steps. Further, (8) and (9) are etching processes, (10) is a wax removing process, and (11) and (12) are end processes.

<Preparation process>
(1) A glass mold mold with a concave molding surface is prepared.
(2) The surface of the glass mold is washed to remove dirt, foreign matter, adhered matter, and the like.

<Masking process (first half = wax application process)>
(3) The glass mold is heated to 38 ° C. to 42 ° C. so that the liquid wax does not immediately solidify and is applied to a uniform thickness.
(4) Apply a wax that has been heated in a liquid state to a uniform thickness so that bubbles, unevenness, and gaps are not formed on the molding surface of the glass mold that provides the mark, and leave it to stand for spontaneous solidification. Let

<Masking process (second half = stamping process)>
(5) Vertical and horizontal reference lines 5 on the convex surface not used for molding of the glass mold 4 before engraving shown in FIG. 3, and vertical and horizontal reference lines 7 and centering pins of the holder jig 6 shown in FIG. 8 is matched and fixed by the spring force of the lens retainer 9. A rubber-like pressing portion (not shown) is attached to the distal end portion of the lens pressing portion 9 and does not damage the molding surface of the glass mold. The reason why the reference line 5 of the glass mold 4 before engraving is on the convex side that is not used for molding is to directly contact the reference line 7 of the holder jig 6 so as to eliminate the parallax and suppress the displacement error. is there.

(6) The operator selects an eyeglass lens item and determines a recognition mark and / or a hidden mark. Set the holder jig to which the glass mold is mounted and fixed on the NC stamping device. The holder jig and NC marking device are provided with a mechanism that cannot be set in any direction other than the designated direction by the positioning pins, thereby preventing setting errors. Wax applied to the glass mold by pressing a sharp marking pin with a spherical tip of 0.15R with a uniform force from the vertical direction against the reference surface of the holder jig and moving it with NC control. Is removed to form a mark (window). This completes a mask for the next etching step.
(7) Remove the glass mold from the holder jig.

<Etching process (mark formation process)>
(8) A hydrogen fluoride solution adjusted to a concentration of about 10% for forming an identification mark and a hydrogen fluoride solution adjusted to a concentration of about 5% for forming a hidden mark And prepare.
(9) After applying a hydrogen fluoride solution having a concentration of about 10% to the identification mark portion, a hydrogen fluoride solution having a concentration of about 5% is applied to the hidden mark portion, and at the same time, time measurement is started. The application method may be applied with a brush or by spraying. Since the depth of the concave groove in the hidden mark portion is desired to be 0.6 μm to 1.0 μm, the next step is washed after about 25 seconds from the characteristic diagram of FIG. 6 to complete the reaction. At that time, the depth of the concave portion on the identification mark side is about 1.6 μm.

  In this way, a plurality of hydrogen fluoride solutions having a predetermined concentration are applied to the engraved portion of the glass mold and allowed to react for a predetermined time. In order to make the contrast of the hidden mark inconspicuous, the conditions (hydrogen fluoride solution concentration and reaction time) for generating the depth of the corresponding recess are set as a reference. On the other hand, the contrast of the identification mark may be relatively rough. After a predetermined time has passed, the hydrogen fluoride solution is washed away with water to terminate the reaction.

<Wax removal process>
(10) Next, the molding surface is washed with warm water of about 85 ° C. higher than the melting point to dissolve and remove the wax. The re-coagulated wax is recovered and reused.

<End process>
(11) The surface of the glass mold is washed to remove wax stains and deposits.
(12) A glass mold with a concave portion (mark) having a desired depth corresponding to the light and shade contrast is completed.

  FIG. 2 is an example of the identification mark 2 and the hidden mark 3 formed on the molding surface by this method. As shown in FIG. 7, a concave groove 14 having no distortion layer or crack layer is finished.

  In the above embodiment, the case where the concave portions having different depths are formed by bringing the hydrogen fluoride solutions having different concentrations into contact with the molding surface of the glass mold for the same reaction time has been described. The concentration of the hydrogen fluoride solution is applied to the stamped part of the glass mold, and the hidden mark stamped part reacts for a shorter period of time than the stamped part of the identification mark. You may make it let.

  For example, using the hydrogen fluoride solution of about 5% concentration in the characteristic diagram of FIG. 6, the marking portion of the hidden mark stops the reaction in 25 seconds and forms a recess at a depth of about 0.8 μm. The stamped portion stops the reaction in 43 seconds and forms a recess at a depth of about 1.6 μm. As a method for stopping the reaction, the hydrogen fluoride solution may be washed with water and dropped.

  As described above, according to the marking method of the glass mold mold according to the embodiment, it is possible to form a plurality of types of groove-shaped marks having different shades on the glass mold mold in a series of steps. As a result, the mark shape recognition rate is improved, and the lifetime of the glass mold itself can be extended. In addition, since wax is used as a masking member for the etching process, it is easy to handle and can be reused, which is useful from the viewpoint of cost and environmental consideration. Furthermore, if a glass mold die obtained by such a method is used, an identification mark or a hidden mark indicating information related thereto such as identification, model number, standard, specific position indication, etc. is applied on the same molding surface. The spectacle lens can be manufactured easily, in large quantities, and stably.

It is process drawing of the marking method of embodiment of this invention. It is a figure which shows an example of the identification mark and hidden mark which were given with the marking method. It is a figure which shows the reference line of the glass mold shaping die before giving marking. It is a top view which shows the holder jig for hold | maintaining a glass mold shaping die. It is sectional drawing which shows the state which mounts and fixes a glass mold shaping | molding die to a holder jig, and is stamped with NC stamping apparatus. Characteristic diagram showing the relationship between the concentration of hydrogen fluoride solution and reaction time and the depth of the recess when etching a recess (concave groove-shaped mark) by bringing a hydrogen fluoride solution (etching solution) into contact with the glass material It is. It is sectional drawing of the part which gave the marking method of this invention. It is a figure which shows the cross section by a laser marking method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass mold mold 2 Identification mark 3 Hidden mark 4 Glass mold mold before engraving 5 Reference line 6 Holder jig 7 Reference line 8 Centering pin 9 Lens holder 10 Reference surface 11 Wax 12 Engraving pin (before movement)
12 'engraved pin (after movement)
13 Forming surface 14 Concave (concave groove)
15 Return 16 Strain layer

Claims (5)

A marking method for providing a plurality of types of marks with different depths on a molding surface of a glass mold for molding a spectacle lens,
A masking step of forming a mask with a coating wax having a window corresponding to the shape of each mark on the molding surface of the glass mold, and an etching process on the molding surface of the glass mold through the mask An etching step of forming a plurality of types of recesses having different depths constituting each mark, and a mask removal step of removing the mask,
In the etching step, etching solutions having different concentrations are brought into contact with the molding surface for the same time through windows corresponding to the marks of the mask, or etching with the same concentration is performed through the windows corresponding to the marks of the mask. A marking method for a glass mold, characterized by forming a plurality of types of recesses having different depths constituting each mark by bringing the liquid into contact with the molding surface for different times.   In the masking step, a protective wax is applied to the molding surface of the glass mold, and then a portion of the window corresponding to the shape of each mark is formed by removing the wax corresponding to the shape of the mark. The marking method for a glass mold according to claim 1, wherein:   The wax is applied in a state in which the glass mold is heated to a temperature substantially equal to the melting point of the wax when the protective wax is applied to the molding surface of the glass mold. The marking method to the glass mold shaping | molding die of 2.   The marking method for a glass mold according to any one of claims 1 to 3, wherein the mark is an identification mark and / or a hidden mark of the glass mold.   The marking method for a glass mold according to claim 4, wherein a depth of the concave portion in the case of forming the hidden mark is 0.6 µm to 1.0 µm.

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