JP2011213005A - Molding die, reproducing method for molding die, and manufacturing method for resin product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a molding die to be repeatedly molded by reproducing the molding die in the molding die for resin molding.SOLUTION: A protective film 23 having resistance to an etching liquid and a film thickness of 10 nm or higher and 100 nm or lower is installed between an intermediate film 24 which is covalently bonded with a release film 25, and a transfer surface processing layer 22 and a body section 21 which constitute the die matrix. Therefore, when the release film 25 is removed by the etching liquid together with the intermediate film 24, the transfer surface processing layer 22 and so forth can be protected from the etching liquid. Thus, even in the molding die 40 of a type wherein the adhering property of the release film 25 has been increased by the intermediate film 24 of the substrate, the reproduction of the molding die wherein the intermediate film 24 and the release film 25 are removed once and formed again becomes possible. In this case, since the protective film 23 has the thickness of 10 nm or higher and 100 nm or lower which is comparatively thin, the shape of the matrix transfer surface 22a in the transfer surface processing layer 22 or the like is maintained, and the transfer accuracy can be increased.

Description

  The present invention relates to a molding die for resin molding, a method for regenerating the same, and a method for producing a resin product using the same, and particularly relates to a molding die for injection molding of a resin optical element.

  As a conventional mold for resin molding, insert a film that strongly binds to both the mold base material and the release film between the mold base material and the release film, so that the release film is firmly attached to the mold. In some cases, the release film is prevented from peeling off (see Patent Document 1). Specifically, a silicon dioxide film for preventing peeling is coated on a mold base material, and a release film made of a silane coupling agent having a fluoroalkyl group is coated thereon.

  Although it relates to a mold for glass molding, a method for regenerating a mold with a release film peeled off at low cost by inserting an etching resistant layer between the mold base material and the release film. (See Patent Document 2). Specifically, a chromium nitride film that is an etching resistant layer is formed on a mold base material, a titanium nitride layer that is soluble in an etching solution is formed thereon, and a multi-nitride such as titanium or aluminum is formed thereon. A release film made of is formed.

JP 2009-184117 A JP 2006-1111496 A

  In the metal mold of Patent Document 1, a large amount of resin molding can be performed by using a silicon dioxide film as a base of a release film, and the number of times of application of the release film can be reduced. However, if the resin molding is repeated in a larger amount, the underlying silicon dioxide film may be partially peeled off. In particular, the durability of the silicon dioxide film tends to be low when the adhesive strength of the resin is strong and a strong stress is applied to the silicon dioxide film.

  In addition, although the metal mold | die of patent document 2 can be reproduced | regenerated even if a release film peels, since the double nitride film | membrane is incompatible with resin and sufficient releasability cannot be obtained, it is molding for resin molding, for example. Cannot be used as a mold.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to regenerate a molding die so that it can be repeatedly molded in a molding die for resin molding.

  In order to solve the above problems, a molding die according to the present invention includes a mold base material that serves as a basis for a transfer surface for resin molding, and a base material transfer surface of the mold base material that covers the base material transfer surface. A protective film having a resistance to an etching solution and having a thickness of 10 nm to 100 nm, an intermediate film formed on the protective film, and a mold release formed on the intermediate film and covalently bonded to the intermediate film And a membrane.

  In the molding die, a protective film having a thickness of 10 nm or more and 100 nm or less between the intermediate film that is covalently bonded to the release film and the mold base material that is a base of the transfer surface and having resistance to the etching solution. Therefore, when the release film is removed together with the intermediate film by the etching solution, the mold base material can be protected from the etching solution. This makes it possible to regenerate the molding die in which the intermediate film and the release film are once removed and formed again even in the type of molding die in which the adhesion of the release film is enhanced by the underlying intermediate film. Here, since the protective film is relatively thin such as 10 nm or more and 100 nm or less, the shape of the base material transfer surface in the mold base material is maintained, and the transfer accuracy can be improved. Note that the film thickness of the protective film is preferably larger than the film thickness of the intermediate film from the viewpoint of reliably protecting the mold base material.

  Moreover, in the specific aspect or side surface of the present invention, in the molding die, the base material transfer surface has a fine shape corresponding to an optical surface having a fine shape. In this case, it can be said that peeling of the intermediate film is likely to occur due to stress at the time of mold release, but the number of moldings using the same mold base material can be dramatically increased by regenerating the mold.

  In another aspect of the present invention, the fine shape formed on the base material transfer surface has a size on the order of nanometers.

  In still another aspect of the present invention, the surface of the mold base material is formed of a plating layer formed by electroless nickel plating. In this case, a highly accurate base material transfer surface having a desired shape can be formed on the surface of the mold base material.

  In yet another aspect of the present invention, the release film is formed of a silane coupling agent having a fluoroalkyl group. In this case, it is possible to effectively prevent the resin molded product from remaining on the transfer surface, increase the yield of the resin molded product, and increase the durability of the molding die.

  In still another aspect of the present invention, the intermediate film is formed of at least one of silicon dioxide, titanium oxide, vanadium oxide, manganese oxide, and zinc oxide. In this case, the bondability with the release film such as a silane coupling agent can be enhanced, and the adhesive force of the release film such as a silane coupling agent can be increased.

  In still another aspect of the present invention, the intermediate film is formed by a vapor phase method. In this case, since the film thickness can generally be controlled with high accuracy, the intermediate film can be appropriately etched, and the possibility of excessive etching that damages the protective film can be reduced.

  In still another aspect of the present invention, the intermediate film is formed by a liquid phase method. In this case, in general, since the film coverage can be improved and a uniform film can be coated on the entire surface of the protective film, a molding die suitable for molding a transfer surface having a fine shape can be provided.

  In still another aspect of the present invention, the protective film is formed of at least one of alumina, silicon carbide, chromium, and chromium oxide. In this case, etching selectivity to the protective film can be provided as compared with an intermediate film made of silicon dioxide, titanium oxide, vanadium oxide, manganese oxide, zinc oxide, etc., and the protective film can be reliably left during etching. .

  The method for regenerating a molding die according to the present invention includes a mold base material that serves as a foundation for a transfer surface for resin molding, and a base material transfer surface that covers the base material transfer surface of the mold base material. A molding die regeneration method comprising: a protective film to be formed; an intermediate film formed on the protective film; and a release film formed on the intermediate film and covalently bonded to the intermediate film. Removing the intermediate film and the release film to expose a protective film having resistance to the etching solution; forming a new intermediate film on the protective film; and forming a new intermediate film on the new intermediate film Forming a release film.

  In the above regeneration method, when the release film is removed together with the intermediate film by the etching solution, the mold base material can be protected from the etching solution by the protective film. This makes it possible to regenerate the molding die that once removes the intermediate film and the release film and re-forms the molding die of the type in which the adhesion of the release film is enhanced by the underlying intermediate film, The number of moldings using the same mold base material can be increased.

  A method for producing a resin product according to the present invention is a method for producing a resin product using a molding die for resin molding, wherein the molding die serves as a base of a transfer surface for resin molding, And a protective film having a thickness of 10 nm or more and 100 nm or less between the release film and the intermediate film that is covalently bonded, and the resin product substantially matches the surface shape of the protective film A transfer surface to be transferred.

  In the above production method, the adhesive property of the release film is enhanced by the underlying intermediate film, and the resin product can be produced by a molding die of a type in which the intermediate film and the release film are once removed and formed again, Highly accurate and inexpensive resin products can be provided stably.

(A) is a fragmentary sectional side view explaining the structure of the molding die for optical elements according to the first embodiment, and (B) is an enlarged side view of a lens that is injection molded by the die of (A). FIG. It is an expanded sectional view which explains notionally an example of the tip structure of a core part. It is an expanded sectional view which illustrates notionally the modification of the tip structure of a core part. (A)-(D) are the figures explaining the reproduction | regeneration method of a shaping die, ie, the core parts 51 and 61. FIG. (A) is a side sectional view of the molding die, that is, the master molding die according to the first embodiment, (B) is a side sectional view showing a wafer lens as a product, (C), It is side sectional drawing of a submaster shaping | molding die. (A)-(D) are the figures explaining the manufacturing process of the wafer lens using a master shaping die.

[First Embodiment]
Hereinafter, a molding die according to a first embodiment of the present invention, a recycling method thereof, and a resin product manufacturing method will be described with reference to the drawings.

  As shown in FIG. 1A, the molding die 40 of this embodiment is composed of a fixed die 41 and a movable die 42, and both the dies 41 and 42 are opened and closed with a parting line PL as a boundary. It is possible. A cavity CV that is a mold space sandwiched between the fixed mold 41 and the movable mold 42 corresponds to the shape of a lens OL (see FIG. 1B) as an optical element that is a resin product, that is, a resin molded product. It has become. The lens OL includes a center portion OLa as an optical function portion having an optical function, and an annular flange portion OLb extending from the center portion OLa in the outer diameter direction. The lens OL is an objective lens for an optical pickup device, an imaging lens for a mobile phone, or the like.

  The fixed mold 41 includes a core part 51, a mold plate 53, and a mounting plate 54. Here, the core portion 51 is disposed to face the core portion 61 of the movable mold 42 in order to form the cavity CV. The mold plate 53 is a mold member that holds the core portion 51 from the periphery, and the mounting plate 54 is a mold member that integrally supports the mold plate 53 and the core portion 51 from behind.

  An optical surface forming surface 56a and a flange forming surface 56b are provided at the distal end portion 51a of the core portion 51 in order to define a cavity CV. The optical surface forming surface 56a is a relatively shallow concave surface, and is a transfer surface for forming one optical surface Sa of the central portion OLa constituting the lens OL. The flange forming surface 56b is an annular flat surface, and is a transfer surface on which one flange surface F1 of the flange portion OLb constituting the lens OL is molded.

  In addition, a columnar through-hole 57a is formed in the template 53 to be supported therein by inserting the core portion 51 therein. The template 53 has an end face 53a that forms a parting line PL.

  The movable mold 42 includes a core part 61, a mold plate 63, and a mounting plate 64. The movable mold 42 is movable along the axis AX and opens and closes with respect to the fixed mold 41. In the movable mold 42, the core portion 61 is disposed to face the core portion 51 of the fixed mold 41 in order to form the cavity CV. The mold plate 63 is a mold member that holds the core portion 61 from the periphery, and the mounting plate 64 is a mold member that integrally supports the mold plate 63 and the core portion 61 from behind.

  An optical surface forming surface 66a and a flange forming surface 66b are provided at the distal end portion 61a of the core portion 61 in order to define a cavity CV. The optical surface forming surface 66a is a relatively deep concave surface, and is a transfer surface for forming the other optical surface Sb of the central portion OLa constituting the lens OL. The flange forming surface 66b is an annular flat surface, and is a transfer surface for forming the other flange surface F2 of the flange portion OLb that constitutes the lens OL.

  In addition, a columnar through hole 67a is formed in the template 63 to be supported therein by inserting the core portion 61 therein. The template 63 has an end face 63a that forms a parting line PL.

  FIG. 2 is an enlarged cross-sectional view conceptually illustrating an example of the structure formed at the tip 51a of the core 51. The tip 51 a has a structure in which a transfer surface processing layer 22, a protective film 23, an intermediate film 24, and a release film 25 are sequentially stacked on the main body portion 21.

  The main body portion 21 is formed of a material such as stainless steel or low carbon steel, and its end surface has a shape corresponding to the optical surface forming surface 56a or the like. In addition, the main-body part 21 can also be formed with a ceramic or a super hard metal.

  The transfer surface processed layer 22 is a nickel phosphorus plating layer formed using, for example, an electroless nickel plating method, and has a thickness of about several tens of μm to several mm. The transfer surface processing layer 22 forms a mold base material together with the main body portion 21, and functions as a base for the optical surface forming surface 56a and the flange forming surface 56b, which are transfer surfaces. The transfer surface processing layer 22 is provided so as to cover the main body portion 21 in order to improve the machinability, and the base material transfer surface 22a which is the surface thereof is processed into a high-precision optical transfer surface. Yes. The transfer surface processed layer 22 can be omitted. In this case, the end surface of the main body portion 21 is precisely processed to form the base material transfer surface 22a.

The protective film 23 is formed of a material such as chromium (Cr), chromium oxide (Cr ₂ O ₃ ), alumina (Al ₂ O ₃ ), or silicon carbide (SiC), and has a thickness of 10 nm to 100 nm. The protective film 23 is provided so as to cover the main body portion 21 in order to protect the transfer surface processed layer 22 from an etching solution for peeling described later. For this reason, the material of the protective film 23 is selected on the basis that it has high chemical durability and can protect the transfer surface processed layer 22 and the like even if the protective film 23 is thin. With respect to the thickness of the protective film 23, resistance to the etching solution can be ensured by setting it to a certain lower limit or more, and by setting it to a certain upper limit or less, the base material transfer surface formed on the transfer surface processed layer 22 22a can be prevented from being deformed or distorted by the protective film 23, and the reproducibility of the optical transfer surface on the optical surface forming surface 56a can be secured. Since the protective film 23 is required to be strongly bonded to the underlying transfer surface processed layer 22, the protective film 23 is formed by, for example, a physical vapor deposition method such as sputtering or vacuum vapor deposition, or a physical vapor deposition method (a kind of vapor phase method). . In particular, sputtering is a method that takes a long time to form a film. However, it is a film forming method that is suitable for covering the protective film 23 because of good adhesion and film coverage. In the case where the substrate transfer surface 22a and the optical surface forming surface 56a shown in the figure are smooth and have few irregularities, the protective film 23 may be covered by vacuum deposition. Although vacuum deposition is inferior to CVD in terms of film adhesion, the film formation time, that is, the coating time can be shortened.

The intermediate film 24 is formed of, for example, a material such as silicon dioxide (SiO ₂ ), titanium oxide (TiO ₂ ), vanadium oxide (V ₂ O ₅ ), manganese oxide (MnO ₂ ), or zinc oxide (ZnO ₂ ). Is thinner than the protective film 23 and has a film thickness of, for example, 100 nm or less. The intermediate film 24 is for stably and firmly supporting a release film 25 to be described later on the protective film 23. The intermediate film 24 is firmly bonded to the intermediate film 24 and the like, so that the release film 25 It has a role to prevent peeling. Therefore, the material of the intermediate film 24 is desirably a metal oxide film having a hydroxyl group on the surface corresponding to the composition of the release film 25. By setting the thickness of the release film 25 to a certain upper limit or less, the base material transfer surface 22a formed on the transfer surface processed layer 22 can be prevented from being deformed or distorted by the protective film 23, and the optical surface forming surface can be prevented. The reproducibility of the optical transfer surface at 56a can be ensured. Further, the intermediate film 24 should be removed by the etching solution, and by making the film thickness below a certain upper limit, the time required for etching can be shortened and the mold regeneration can be made quick. I am doing so. From the viewpoint of reducing the possibility that the protective film 23 is damaged by excessive etching by controlling the film thickness with high precision, the intermediate film 24 is a vapor phase method such as CVD (a kind of chemical vapor deposition method). ). When the intermediate film 24 formed by a vapor phase method such as CVD is immersed in an etching solution, it is normally etched uniformly regardless of the shape and location. Good throwing power is required. In particular, CVD is a film forming method suitable for coating the intermediate film 24 because it has a lower adhesion than sputtering but has excellent film coverage. If the substrate transfer surface 22a and the optical surface forming surface 56a shown in the figure are smooth and have few irregularities, the intermediate film 24 may be covered by vacuum deposition. Although vacuum deposition is inferior to CVD from the viewpoint of covering the film, the film formation time, that is, the coating time can be shortened. Further, the intermediate film 24 can also be formed by a liquid phase precipitation method disclosed in Japanese Patent Application Laid-Open No. 2009-184117. Since the liquid phase deposition method is generally not easy to control the film thickness, it is inferior to CVD from the viewpoint of properly removing the intermediate film 24 by etching when the substrate transfer surface 22a is smooth and has few irregularities. it is conceivable that.

The release film 25 is formed of a material such as a silane coupling agent that is covalently bonded to the intermediate film 24, and usually forms a single layer film of about 5 nm on the intermediate film 24. As the silane coupling agent for forming the release film 25, one having a fluoroalkyl group is generally used. This is because the small surface free energy of fluorine exhibits a function of reducing the adhesion between the end face of the core portion 51 and the resin product, that is, the resin molded product. As the silane coupling agent having a fluoroalkyl group, for example, the following are common.
CF ₃ (CH ₂ ) ₂ SiCl ₃
CF ₃ (CH ₂ ) ₅ SiCl ₃
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl ₃
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃
CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) Cl ₃
CF ₃ (CH ₂ ) ₂ Si (OCH ₃ ) _{3
CF 3 (CH 2) 2 Si} (CH 3) (OHCH 3) 2
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ Si (OCH ₃ ) ₃
These substances are used after being diluted with a fluorine-based organic solvent. A solution obtained by diluting the silane coupling agent with an organic solvent is prepared, and the core portion 51 is immersed in this solution and slowly pulled up (dip coating), or droplets of this solution are applied to the end surface of the core portion 51. A thin film of a silane coupling agent is formed on the end face of the core portion 51, that is, the surface of the intermediate film 24 by dropping and spreading at high speed (spread coating). Then, it is hydrolyzed by heating under a certain humidity. At this time, the chloro group (—Cl) and methoxy group (—OCH ₃ ) of the silane coupling agent become silanol (Si—OH). The silanol immediately undergoes a dehydration condensation reaction with the hydroxy group (—OH) on the surface of the intermediate film 24, whereby the surface layer of the intermediate film 24 and the silane coupling agent are bonded by a covalent bond. As described above, the release film 25 of the silane coupling agent covalently bonded to the intermediate film 24 can be formed so as to cover the intermediate film 24 thinly.

  FIG. 3 is an enlarged cross-sectional view for conceptually explaining a modified example of the structure formed at the distal end portion 51 a of the core portion 51. Also in this case, the front end portion 51a has a structure in which the transfer surface processed layer 22, the protective film 23, the intermediate film 24, and the release film 25 are sequentially laminated on the main body portion 21. However, the surface of the transfer surface processed layer 22 is processed into a base material transfer surface 122a provided with a fine shape having a size of nanometer order. The fine shape of the base material transfer surface 122a is reproduced or transferred to the surface of the protective film 23, and also reproduced or transferred to the surfaces of the intermediate film 24 and the release film 25. As a result, a nanometer-order fine shape FS is formed on the optical surface forming surface 56 a that is the end surface of the core portion 61. Note that the fine shape FS is not limited to the sawtooth blaze type exaggerated in the drawings, and may be various types such as a rectangular step type.

  In the case of the core portion 51 as shown in FIG. 3, it is easy to provide a nanometer order structure by providing the transfer surface processed layer 22. The protective film 23 is desirably formed by sputtering with good adhesion and film coverage. The intermediate film 24 can be coated on the entire surface by forming the intermediate film 24 by a liquid phase precipitation method that is easy to get into the shaded portion of the fine shape. The intermediate film 24 can also be formed by CVD with relatively good film coverage.

  The core part 61 of the movable mold 42 can also have the same structure as the core part 51 as shown in FIGS. That is, although the detailed description is omitted, the tip portion 61 a of the core portion 61 is formed by sequentially laminating the transfer surface processing layer 22, the protective film 23, the intermediate film 24, and the release film 25 on the main body portion 21. Has the structure.

  Hereinafter, a method for manufacturing a resin product using the molding die 40 of FIG. 1 will be described. Although not shown, the molding die 40 is used by being incorporated in an injection molding machine, and the fixed die 41 is fixed to a stationary platen of the injection molding machine, and a movable die 42 is used. Is fixed to the movable platen of the injection molding machine.

  First, both molds 41 and 42 are heated to a temperature suitable for molding by a mold temperature controller (not shown). Next, the movable platen that supports the movable die 42 is brought close to the fixed platen that supports the fixed die 41, and is moved to the die contact position where the fixed die 41 and the movable die 42 are in contact with each other to close the die. At the same time, mold clamping is performed to clamp the fixed mold 41 and the movable mold 42 with a necessary pressure. Next, an injection device (not shown) is operated to inject the molten resin into the cavity CV between the fixed mold 41 and the movable mold 42, which are clamped, at a necessary pressure. At this time, the fixed mold 41 and the movable mold 42 are appropriately heated by the mold temperature controller, and the molten resin supplied from the injection apparatus is slowly cooled. When the molten resin is cooled and sufficiently cured, the fixed mold 41 and the movable mold 42 are separated from each other by performing mold opening for retracting the movable mold 42. As a result, the lens OL as a resin molded product can be taken out between the two molds 41 and 42.

  In addition, when the above injection molding is repeated many times, the mold release film 25 on the end surfaces of the core portions 51 and 61 of both molds 41 and 42 is partially removed. Therefore, the silane coupling agent is reattached to the end faces of the core portions 51 and 61 periodically. Thereby, the protective film 23 that sufficiently covers the intermediate film 24 can be regenerated.

  Hereinafter, a method for regenerating the molding die 40 will be described with reference to FIGS. 4 (A) to 4 (D). If the injection molding using the molding die 40 is repeated many more times, the intermediate film 24 on the end faces of the core portions 51 and 61 of both molds 41 and 42 is partially removed together with the release film 25. In this case, since the molding die 40 cannot be regenerated by the reattachment process of the silane coupling agent, the core portions 51 and 61 are brought into a substantially initial state by re-forming the intermediate film 24 and the release film 25. Can be played.

  As shown in FIG. 4A, when the injection molding is repeated many times, a defect portion DF from which the intermediate film 24 and the like are peeled is formed on the end surfaces of the core portions 51 and 61. If the use of the core portions 51 and 61 is continued as it is, the resin molded product will be burned, so that the core portions 51 and 61 are regenerated.

  Specifically, first, as shown in FIG. 4B, the intermediate film 24 and the release film 25 are removed by etching. The components of the etching solution are selected according to the composition of the intermediate film 24 and the protective film 23. For example, only the intermediate film 24 is selected by using one containing hydrofluoric acid, hydrochloric acid, nitric acid, hydrogen peroxide water, or the like. Therefore, the damage to the protective film 23 can be reduced.

  Next, as shown in FIG. 4C, an intermediate film 24 that covers the protective film 23 is formed on the protective film 23 exposed on the end faces of the core portions 51 and 61. The re-covering intermediate film 24 is the same as the original intermediate film 24 and is formed of a material such as silicon dioxide, titanium oxide, vanadium oxide, manganese oxide, zinc oxide, and has a film thickness of, for example, 100 nm or less. Shall. The intermediate film 24 for re-coating is formed in the same manner as the original intermediate film 24. That is, the intermediate film 24 is formed by a vapor phase method such as CVD (a type of chemical vapor deposition method). The intermediate film 24 can also be formed by vacuum deposition. Furthermore, the intermediate film 24 can also be formed by a liquid phase deposition method.

  Thereafter, as shown in FIG. 4D, a release film 25 that covers the intermediate film 24 is formed on the intermediate film 24 that covers the end faces of the core portions 51 and 61. The re-covering release film 25 is the same as the original release film 25 and is formed of a material such as a silane coupling agent. The release film 25 for re-coating is formed in the same manner as the original release film 25. Specifically, a solution of the silane coupling agent is thinly applied to the end surface of the core portion 51, and the silane coupling agent is hydrolyzed by performing a treatment such as heating, and the silane coupling agent is applied to the surface of the intermediate film 24. The release film 25 can be formed on the intermediate film 24 by covalent bonding.

  Specific examples will be described below.

[Example 1]
First, the main body portion 21 was prepared, a transfer surface processing layer 22 as a nickel phosphorus plating layer was formed by an electroless nickel plating method, and a base material transfer surface 22a having a desired shape was formed by cutting. Next, after cleaning the surfaces of the core parts 51 and 61, the end face of the core parts 51 and 61 was coated with a film thickness of about 40 nm by sputtering to form the protective film 23. On the chromium film, an intermediate film 24 was formed by coating silicon dioxide with a film thickness of about 20 nm by CVD. A release film 25 was formed by applying a silane coupling agent on the silicon dioxide film and performing a treatment such as heating. In this case, OPTOOL DSX (trade name) is used as the silane coupling agent. At this time, since the OPTOOL DSX forms a monomolecular layer, the thickness of the release film 25 is about 5 nm. By processing as described above, it is possible to cover the surface of the core portions 51 and 61, that is, the optical surface forming surfaces 56a and 66a, with an optool film having good releasability from the resin. Since the release film 25 made of the optool film is covalently bonded to the underlying SiO ₂ film intermediate film 24, the release film 25 is firmly bonded to the underlying layers of the core portions 51 and 61. Furthermore, since the total film thickness of the protective film 23, the intermediate film 24, and the release film 25 coated on the base material transfer surface 22a is as thin as about 65 nm, the outermost surfaces of the core portions 51 and 61, that is, the optical surface forming surface The shapes 56a and 66a accurately reproduce the shape of the base material transfer surface 22a.

The release film 25 made of the optool film and the intermediate film 24 made of the SiO ₂ film therebelow deteriorated when the molding was repeated, and the releasability deteriorated. Therefore, the core portions 51 and 61 deteriorated in this way were reproduced by the following processing. Specifically, a glass coat removing liquid was used as an etching liquid used for removing the intermediate film 24 and the like. The main components of this etching solution are ammonium bifluoride and hydrogen peroxide. The appropriate portions of the core portions 51 and 61 are immersed in this etching solution for 10 minutes. As a result of the compositional analysis of the surfaces of the core portions 51 and 61 after immersion, only chromium oxide is detected. This means that the release film 25 of the optool film and the intermediate film 24 of the SiO ₂ film are removed by the etching liquid, and the exposed oxide film of the chromium film is detected. Therefore, it has been found that the etching process as described above is stopped by the chromium film, and the protective film 23 made of chromium plays a role as the protective film. An intermediate film 24 and a release film 25 were sequentially formed on the exposed chromium protective film 23 by sequentially covering a silicon dioxide film and an optool film in this order. Through the above regeneration process, the core portions 51 and 61 again have releasability, and a resin molded product having a precise shape as in the original can be manufactured. That is, the core portions 51 and 61 as the molds could be regenerated without processing or polishing.

[Example 2]
Similarly to Example 1, a main body portion 21 was prepared, a transfer surface processed layer 22 was formed by an electroless nickel plating method, and a base material transfer surface 22a was formed on this surface. Next, after cleaning the surfaces of the core portions 51 and 61, the end surfaces of the core portions 51 and 61 were covered with a silicon carbide film with a thickness of about 40 nm by sputtering to form the protective film 23. On the protective film 23, an intermediate film 24 was formed by coating silicon dioxide with a film thickness of about 20 nm by CVD. A release film 25 having a thickness of about 5 nm was formed by applying a silane coupling agent (specifically, OPTOOL DSX (trade name)) on the intermediate film 24 and performing a treatment such as heating. By performing the treatment as described above, the surfaces of the core portions 51 and 61, that is, the optical surface forming surfaces 56a and 66a can be covered with a silane coupling agent having good releasability from the resin. The release film 25 is covalently bonded to the underlying SiO ₂ intermediate film 24 and is firmly bonded to the underlying portions of the core portions 51 and 61. Furthermore, since the total film thickness of the protective film 23, the intermediate film 24, and the release film 25 coated on the base material transfer surface 22a is as thin as about 65 nm, the outermost surfaces of the core portions 51 and 61, that is, the optical surface forming surface The shapes 56a and 66a accurately reproduce the shape of the base material transfer surface 22a.

The release film 25 made of a silane coupling agent and the intermediate film 24 made of SiO ₂ therebelow deteriorated when the molding was repeated, and the release properties deteriorated. Therefore, the core portions 51 and 61 deteriorated in this way were reproduced by the following processing. Specifically, a glass coat removing liquid was used as an etching liquid used for removing the intermediate film 24 and the like. The appropriate portions of the core portions 51 and 61 are immersed in this etching solution for 10 minutes. As a result of composition analysis of the surfaces of the core portions 51 and 61 after immersion, only silicon carbide is detected. That is, it has been found that the etching process as described above is stopped by the silicon carbide film, and the protective film 23 made of silicon carbide plays a role as a protective film. On the exposed protective film 23 made of silicon carbide, an intermediate film 24 and a release film 25 were sequentially formed by coating a silicon dioxide film and a film made of a silane coupling agent in this order. Through the above regeneration process, the core portions 51 and 61 again have releasability, and a resin molded product having a precise shape as in the original can be manufactured. That is, the core portions 51 and 61 as the molds could be regenerated without processing or polishing.

Example 3
Similarly to Example 1, a main body portion 21 was prepared, a transfer surface processed layer 22 was formed by an electroless nickel plating method, and a base material transfer surface 22a was formed on this surface. Next, after cleaning the surfaces of the core portions 51 and 61, the protective film 23 was formed by coating the end faces of the core portions 51 and 61 with a film thickness of about 40 nm by sputtering. On the protective film 23, an intermediate film 24 was formed by coating silicon dioxide with a film thickness of about 20 nm by CVD. A release film 25 having a thickness of about 5 nm was formed by applying a silane coupling agent (specifically, OPTOOL DSX (trade name)) on the intermediate film 24 and performing a treatment such as heating. By performing the treatment as described above, the surfaces of the core portions 51 and 61, that is, the optical surface forming surfaces 56a and 66a can be covered with a silane coupling agent having good releasability from the resin. The release film 25 is covalently bonded to the underlying SiO ₂ intermediate film 24 and is firmly bonded to the underlying portions of the core portions 51 and 61. Furthermore, since the total film thickness of the protective film 23, the intermediate film 24, and the release film 25 coated on the base material transfer surface 22a is as thin as about 65 nm, the outermost surfaces of the core portions 51 and 61, that is, the optical surface forming surface The shapes 56a and 66a accurately reproduce the shape of the base material transfer surface 22a.

The release film 25 made of a silane coupling agent and the intermediate film 24 made of SiO ₂ therebelow deteriorated when the molding was repeated, and the release properties deteriorated. Therefore, the core portions 51 and 61 deteriorated in this way were reproduced by the following processing. Specifically, a glass coat removing liquid was used as an etching liquid used for removing the intermediate film 24 and the like. The appropriate portions of the core portions 51 and 61 are immersed in this etching solution for 10 minutes. As a result of composition analysis of the surfaces of the core portions 51 and 61 after immersion, only alumina is detected. That is, it has been found that the etching process as described above is stopped by the alumina film, and the protective film 23 made of alumina plays a role as a protective film. On the exposed protective film 23 made of alumina, an intermediate film 24 and a release film 25 were sequentially formed by covering a new silicon dioxide film and a film made of a silane coupling agent in this order. Through the above regeneration process, the core portions 51 and 61 again have releasability, and a resin molded product having a precise shape as in the original can be manufactured. That is, the core portions 51 and 61 as the molds could be regenerated without processing or polishing.

Example 4
Similarly to Example 1, a main body portion 21 was prepared, a transfer surface processed layer 22 was formed by an electroless nickel plating method, and a base material transfer surface 22a was formed on this surface. Next, after cleaning the surfaces of the core portions 51 and 61, the end surfaces of the core portions 51 and 61 were coated with a film thickness of about 40 nm by sputtering to form the protective film 23. On the protective film 23, an intermediate film 24 was formed by coating silicon dioxide with a film thickness of about 20 nm by CVD. A release film 25 having a thickness of about 5 nm was formed by applying a silane coupling agent (specifically, OPTOOL DSX (trade name)) on the intermediate film 24 and performing a treatment such as heating. By performing the treatment as described above, the surfaces of the core portions 51 and 61, that is, the optical surface forming surfaces 56a and 66a can be covered with a silane coupling agent having good releasability from the resin. The release film 25 is covalently bonded to the underlying SiO ₂ intermediate film 24 and is firmly bonded to the underlying portions of the core portions 51 and 61. Furthermore, since the total film thickness of the protective film 23, the intermediate film 24, and the release film 25 coated on the base material transfer surface 22a is as thin as about 65 nm, the outermost surfaces of the core portions 51 and 61, that is, the optical surface forming surface The shapes 56a and 66a accurately reproduce the shape of the base material transfer surface 22a.

The release film 25 made of a silane coupling agent and the intermediate film 24 made of SiO ₂ therebelow deteriorated when the molding was repeated, and the release properties deteriorated. Therefore, the core portions 51 and 61 deteriorated in this way were reproduced by the following processing. Specifically, a glass coat removing liquid was used as an etching liquid used for removing the intermediate film 24 and the like. The appropriate portions of the core portions 51 and 61 are immersed in this etching solution for 10 minutes. As a result of the compositional analysis of the surfaces of the core portions 51 and 61 after immersion, only chromium oxide is detected. That is, it has been found that the etching process as described above is stopped by the chromium oxide film, and the protective film 23 made of chromium oxide plays a role as a protective film. On the exposed protective film 23 made of chromium oxide, an intermediate film 24 and a release film 25 were sequentially formed by coating a silicon dioxide film and a film made of a silane coupling agent in this order. Through the above regeneration process, the core portions 51 and 61 again have releasability, and a resin molded product having a precise shape as in the original can be manufactured. That is, the core portions 51 and 61 as the molds could be regenerated without processing or polishing.

Example 5
Similarly to Example 1, a main body portion 21 was prepared, a transfer surface processed layer 22 was formed by an electroless nickel plating method, and a base material transfer surface 22a was formed on this surface. Next, after cleaning the surfaces of the core parts 51 and 61, the protective film 23 was formed by coating the end faces of the core parts 51 and 61 with a film thickness of about 40 nm by sputtering. On the protective film 23, an intermediate film 24 was formed by coating titanium oxide with a film thickness of about 20 nm by CVD. A release film 25 having a thickness of about 5 nm was formed by applying a silane coupling agent (specifically, OPTOOL DSX (trade name)) on the intermediate film 24 and performing a treatment such as heating. By performing the treatment as described above, the surfaces of the core portions 51 and 61, that is, the optical surface forming surfaces 56a and 66a can be covered with a silane coupling agent having good releasability from the resin. The release film 25 is covalently bonded to the underlying titanium oxide intermediate film 24 and is firmly bonded to the underlying portions of the core portions 51 and 61. Furthermore, since the total film thickness of the protective film 23, the intermediate film 24, and the release film 25 coated on the base material transfer surface 22a is as thin as about 65 nm, the outermost surfaces of the core portions 51 and 61, that is, the optical surface forming surface The shapes 56a and 66a accurately reproduce the shape of the base material transfer surface 22a.

  The release film 25 made of a silane coupling agent and the intermediate film 24 made of titanium oxide therebelow deteriorated when molding was repeated, and the release properties deteriorated. Therefore, the core portions 51 and 61 deteriorated in this way were reproduced by the following processing. Specifically, a glass coat removing liquid was used as an etching liquid used for removing the intermediate film 24 and the like. The appropriate portions of the core portions 51 and 61 are immersed in this etching solution for 10 minutes. As a result of the compositional analysis of the surfaces of the core portions 51 and 61 after immersion, only chromium oxide is detected. That is, it has been found that the etching process as described above is stopped by the chromium oxide film, and the protective film 23 made of chromium plays a role as a protective film. On the exposed chromium protective film 23, a titanium oxide film and a silane coupling agent film were newly coated in this order to form an intermediate film 24 and a release film 25 sequentially. Through the above regeneration process, the core portions 51 and 61 again have releasability, and a resin molded product having a precise shape as in the original can be manufactured. That is, the core portions 51 and 61 as the molds could be regenerated without processing or polishing.

  As described above, according to the molding die and the reproducing method thereof according to the present embodiment, the intermediate film 24 that is covalently bonded to the release film 25, the transfer surface processing layer 22 and the main body portion 21 constituting the die base material. Since the protective film 23 having resistance to the etching solution and having a film thickness of 10 nm or more and 100 nm or less is provided between the transfer film processing layer 22 and the intermediate film 24 together with the intermediate film 24, the transfer surface processed layer 22 is removed. Etc. can be protected from the etching solution. As a result, even in the molding die 40 of the type in which the adhesion of the release film 25 is enhanced by the underlying intermediate film 24, the intermediate mold 24 and the release film 25 are removed once and the molding die 40 is formed again. Playback is possible. Here, since the protective film 23 is relatively thin such as 10 nm or more and 100 nm or less, the shape of the base material transfer surface 22a in the transfer surface processed layer 22 or the like is maintained, and transfer accuracy can be improved.

[Second Embodiment]
A molding die 441 according to the second embodiment shown in FIG. 5A is a master molding die, and is used for molding or manufacturing a wafer lens WL as a resin product shown in FIG. In manufacturing the wafer lens WL, a sub-master mold 442 shown in FIG. 5C is used as a mold for molding in addition to the mold 441 shown in FIG. 5A. Note that the sub-master mold 442 has a strength increased by attaching a backing material 447 to the back side of the molding body molding part 446 having an optical surface forming surface 457a and other surfaces 457b.

  An optical surface forming surface 456a and a non-optical surface forming surface 456b are formed on the surface portion 441a of the molding die 441. The structure of the surface portion 441a of the molding die 441 is the same as that shown in FIG. 2, and the transfer surface processed layer 22, the protective film 23, the intermediate film 24, and the release film are formed on the main body portion 21. 25 are sequentially stacked.

Hereinafter, an example of a method for manufacturing the wafer lens WL using the molding die 441 of FIG. First, a molding die 441 is prepared (see FIG. 6A). The manufacturing method of the molding die 441 is the same as the manufacturing method of the core part 51 shown in FIG. That is, the base material of the molding die 441 is covered with a nickel phosphorus plating layer to form the transfer surface processed layer 22, and chromium (Cr), chromium oxide (Cr ₂ O ₃ ) or the like is formed by a vapor phase method. The protective film 23 is used. On top of that, silicon dioxide (SiO ₂ ) and titanium oxide (TiO ₂ ) are formed by a vapor phase method to form an intermediate film 24 thinner than the protective film 23. This protective film 23 is covered with a release film 25 formed of a material such as a silane coupling agent.

  Next, a sub master mold 442 is manufactured from the mold 441 (see FIG. 6B). The sub master mold 442 is made of a resin, and any of a photocurable resin, a thermosetting resin, and a thermoplastic resin may be used. Here, the optical surface forming surface 456a and the non-optical surface forming surface 456b of the molding die 441 are covered with the release film 25, so that the sub master molding die 442 can be easily released.

  Next, a glass substrate GP is prepared, and a resin is filled between the glass plate GP and the surface portion 442a of the sub master mold 442 and cured (see FIG. 6C). More specifically, the optical surface forming surface 457a that forms the concave portion of the sub master mold 442 is filled with the resin RE, the glass substrate GP is pressed from above, and the filled resin RE is cured. Instead of filling the sub master mold 442 with the resin RE, it is also possible to apply the resin RE to the glass substrate GP and press the glass substrate GP coated with the resin RE against the sub master mold 442. For the application of the resin RE, techniques such as spray coating and spin coating can be used. For curing the resin RE, for example, light irradiation to the resin RE is performed by a light source disposed behind one or both of the glass plate GP and the sub master mold 442. The lens portion LP is formed on the glass substrate GP by curing the resin RE.

  Thereafter, when the resin RE filled between the glass plate GP and the optical surface forming surface 457a of the sub master mold 442 is cured, the glass plate GP provided with the lens portion LP is removed from the sub master mold 442. Release (see FIG. 6D). Thereby, the wafer lens WL provided with the cured resin RE, that is, the lens portion LP on the glass substrate GP is obtained.

  In the production of the wafer lens WL as described above, when the use of the molding die 441 is repeated many times, the release film 25 on the surface of the molding die 441 is partially removed. Therefore, the silane coupling agent is reattached to the surface of the molding die 441 periodically. Thereby, the protective film 23 that sufficiently covers the intermediate film 24 can be regenerated.

  Further, when the production of the wafer lens WL using the molding die 441 is repeated many more times, the intermediate film 24 on the end face of the molding die 441 is partially removed together with the release film 25. In this case, since the molding die 40 cannot be regenerated by the reattachment process of the silane coupling agent, the core portions 51 and 61 are brought into a substantially initial state by re-forming the intermediate film 24 and the release film 25. Can be played. The specific process is the same as the regeneration of the core portions 51 and 61 of the molding die 40 described in the first embodiment (see FIGS. 4A to 4D).

  In the above second embodiment, the wafer lens WL is completed by providing the lens portion LP only on one surface of the glass plate GP. However, both surfaces of the glass plate GP are formed using a molding die similar to the molding die 441. A lens portion LP can also be provided. Further, the number and arrangement of the lens portions LP can be changed as appropriate according to the application.

  Also according to the second embodiment described above, when the release film 25 is removed together with the intermediate film 24 by the etching solution, the transfer surface processed layer 22 and the like can be protected from the etching solution. As a result, even in the molding die 441 of the type in which the adhesion of the release film 25 is enhanced by the underlying intermediate film 24, the intermediate mold 24 and the release film 25 are removed once and the molding die 441 is formed again. Playback is possible.

  In addition, although detailed description is abbreviate | omitted also about the shaping die 441 of 2nd Embodiment, the result similar to Examples 1-5 of the said 1st Embodiment was obtained.

  Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications are possible. For example, in the first embodiment, the transfer surface processing layer 22, the protective film 23, the intermediate film 24, and the release film 25 are provided at the tip portions 51a and 61a of the core parts 51 and 61. When the fixed mold 41 and the movable mold 42 are integrated molds that do not have the core portions 51 and 61, the transfer surface processing layer shown in FIG. 2 or the like at the end of the fixed mold 41 or the movable mold 42. 22, a protective film 23, an intermediate film 24, a release film 25, and the like can be provided.

  Further, in the core portions 51 and 61 and the molding die 441, an additional film or layer can be formed between the main body portion 21 and the transfer surface processed layer 22.

  In addition, the shape of the cavity CV provided in the injection mold composed of the fixed mold 41 and the movable mold 42 is not limited to the illustrated one, and various shapes can be used. That is, the shape of the cavity CV formed by the core portions 51, 61 and the like is merely an example, and can be appropriately changed according to the use of the lens OL. Further, the shape of the optical surface forming surface 456a formed on the surface portion 441a of the molding die 441 is not limited to the shape shown in the figure, and various shapes can be used.

DESCRIPTION OF SYMBOLS 21 ... Main-body part, 2 ... Transfer surface processed layer, 2a ... Base material transfer surface, 3 ... Protective film, 4 ... Intermediate film, 25 ... Release film, 40 ... Molding die, 41 ... Fixed die, 42 ... Movable 51 ... Core part, 51a ... Tip part, 51a, 61a ... Tip part, 53 ... Mold plate, 54 ... Mounting plate, 56a ... Optical surface forming surface, 56b ... Flange forming surface, 57a ... Through hole, 61 ... Core part, 61a ... tip part, 63 ... template, 64 ... mounting plate, 66a ... optical surface forming surface, 66b ... flange forming surface, AX ... shaft, CV ... cavity, FS ... fine shape, OL ... lens, OLa ... Center part, PL ... Parting line, Sa, Sb ... Optical surface

Claims (11)

A mold base material that is the basis of a transfer surface for resin molding;
A protective film formed on the base material transfer surface of the mold base material so as to cover the base material transfer surface, having resistance to an etching solution, and having a film thickness of 10 nm or more and 100 nm or less;
An intermediate film formed on the protective film;
A molding die having a release film formed on an intermediate film and covalently bonded to the intermediate film.   The molding die according to claim 1, wherein the base material transfer surface has a fine shape corresponding to an optical surface having a fine shape.   3. The molding die according to claim 2, wherein the fine shape formed on the base material transfer surface has a size on the order of nanometers.   The surface of the said mold base material is formed with the plating layer formed by electroless nickel plating, The molding die as described in any one of Claim 1- Claim 3 characterized by the above-mentioned.   The mold according to any one of claims 1 to 4, wherein the release film is formed of a silane coupling agent having a fluoroalkyl group.   6. The intermediate film according to claim 1, wherein the intermediate film is made of at least one of silicon dioxide, titanium oxide, vanadium oxide, manganese oxide, and zinc oxide. Molding mold.   The molding die according to claim 6, wherein the intermediate film is formed by a vapor phase method.   The molding die according to claim 6, wherein the intermediate film is formed by a liquid phase method.   The molding die according to any one of claims 1 to 8, wherein the protective film is formed of at least one of alumina, silicon carbide, chromium, and chromium oxide. A mold base material serving as a base of a transfer surface for resin molding, a protective film formed on the base material transfer surface of the mold base material so as to cover the base material transfer surface, and on the protective film A method for regenerating a molding die comprising: an intermediate film to be formed; and a release film formed on the intermediate film and covalently bonded to the intermediate film,
Exposing the protective film having resistance to the etching solution by immersing in the etching solution and removing the intermediate film and the release film; and
Forming a new intermediate film on the protective film;
And a step of forming a new release film on the new intermediate film. A method for producing a resin product using a molding die for resin molding,
The molding die has a resistance to an etching solution between a mold base material serving as a base of a transfer surface for resin molding and an intermediate film covalently bonded to a release film, and is a film having a thickness of 10 nm to 100 nm. Having a protective film having a thickness;
The method for producing a resin product, wherein the resin product has a transferred surface that substantially matches a surface shape of the protective film.

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