JP2008239417A - Method for removing coating film from glass mold and method for manufacturing glass mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for removing a coating film from a glass mold without damaging the surface of a mold substrate part as much as in conventional methods, and to provide a method for manufacturing the glass mold using the method for removing the coating film. <P>SOLUTION: The coating film, which is composed of at least one layer on the surface of the mold substrate part, is removed from the glass mold by blasting the surface of the glass mold using an abrasive material in which abrasive grains are dispersed in a rubber. Preferably, an Ir-containing coating film or a diamond-like carbon coating film is formed as the outermost surface of the glass mold. Optionally, at least one layer of the coating film may be formed on the exposed surface of the mold substrate part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for removing a film from a glass mold and a method for producing a glass mold.

  In various industrial fields, molding with a mold is performed in order to impart a shape to a material. Molding with a mold has advantages such as relatively easy mass production of the same shape as compared to grinding.

  In recent years, attempts have been made to press-mold a glass member using a glass mold in the field of manufacturing a glass member in order to take advantage of such molding.

  Various functional films may be laminated on the surface of the base of the glass mold. For example, a release film having a function of promoting release from glass is provided on the outermost surface of the glass mold. Sometimes.

  A metal film or the like may be used for the release film, but the release film deteriorates due to oxidation or the like due to use at a high temperature, etc., and the glass tends to be fused to the mold, making it difficult to mold. was there.

  An expensive material such as WC is often used for the base material of the glass mold. For this reason, attempts have been made to remove the deteriorated film and reuse the glass mold.

  Conventionally, as a method for removing a deteriorated film, for example, a method of chemically immersing in a cyan (CN) -based or HBr-based film remover, a method of immersing in an electrolytic solution, and using electrolysis A method of chemically dissolving a film, a method of oxidizing and removing a film by oxygen ashing, and the like have been studied, but it has been difficult to sufficiently remove a deteriorated film by these methods.

  In particular, in the case of a glass mold, the higher the adhesion between the surface of the substrate portion and the coating film, the better from the viewpoint of preventing the coating from peeling off during the production of the glass molding. For this reason, it is very difficult to peel the coating film from the glass mold because it is in a relationship contrary to improving the adhesion.

Therefore, in order to improve such a problem, for example, Patent Document 1 discloses that sandblasting is performed on the molding surface of an optical element molding die for molding glass or the like using oxide particles such as BeO, CeO ₂ and MgO. A method of performing and physically removing the degraded coating is disclosed.

JP 2002-255572 A

  However, as in Patent Document 1, in the method of removing the coating by blasting the surface of the mold base of the glass mold using only hard oxide particles, the surface of the mold base is scratched. There is a problem that the roughness of the surface of the mold base portion increases.

  Therefore, the problem to be solved by the present invention is to provide a method for removing a coating film from a glass mold in which the surface of the mold base is less likely to be damaged than in the prior art. Another object is to provide a method for producing a glass mold using the film removal method.

  In order to solve the above-mentioned problems, the method for removing a film of a glass mold according to the present invention comprises a film of a glass mold in which at least one layer of film is formed on the surface of the mold base, and abrasive grains in rubber. The gist is to blast the surface of the glass mold using a dispersed abrasive.

  An Ir-containing film or a diamond-like carbon film is preferably formed on the outermost surface of the glass mold.

  The Ir-containing film may be an Ir film, an Ir—Pt film, or an Ir—Re film.

  The abrasive grains are preferably alumina and / or silica.

  On the other hand, in the method for producing a glass mold according to the present invention, the surface of the glass mold in which at least one layer of film is formed on the surface of the mold base is formed by using an abrasive in which abrasive grains are dispersed in rubber. The gist is to have a step of blasting using and exposing the surface of the mold base part.

  Furthermore, it is preferable to have a step of forming at least one layer of film on the exposed mold base portion surface.

  According to the method for removing a film from a glass mold according to the present invention, the surface of the glass mold is blasted using an abrasive in which abrasive grains are dispersed in rubber. The surface of the part is hard to be damaged. Moreover, it can suppress that the roughness of the mold base part surface increases.

  This is because the rubber has adhesiveness, and when the abrasive is blasted onto the surface of the glass mold, the rubber adheres to the coating effectively along with the impact of the abrasive particles on the coating. This is presumably because the film can be peeled off.

  In addition, according to the above method, even if fine processing such as micron order is performed on the surface of the mold base portion of the glass mold, it is possible to suppress an increase in the roughness of the surface of the mold base portion, The film can be efficiently removed.

  In addition, even when a metal film or a hard film is formed on the outermost surface of the glass mold, it is possible to suppress the surface of the mold base portion of the glass mold from being scratched during blasting. it can.

  Moreover, if the said abrasive grain is an alumina and / or a silica, it will be further excellent in the said effect.

  Furthermore, according to the method for producing a glass mold according to the present invention, the surface of the glass mold is blasted using an abrasive in which abrasive grains are dispersed in rubber. The surface of the material is hard to be scratched.

  And when it has the process of forming the film of at least 1 layer or more on the mold base part surface of the glass mold exposed by the blasting process, the roughness of the mold base part surface was re-formed. Hard to affect the coating. Therefore, with the glass mold regenerated by the above method, a glass molded product having almost no difference from the new glass mold can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail.

  In the method for removing a film of a glass mold according to the present invention, the film formed on the surface of the mold base portion of the glass mold is removed by blasting using an abrasive in which abrasive grains are dispersed in rubber.

  Examples of the rubber used as the base material of the abrasive include butadiene rubber (BR, NBR, SBR, etc.), natural rubber (NR), isoprene rubber (IR), ethylene-propylene rubber (EPR, EPDM). Etc. can be illustrated. Preferably, butadiene rubber can be used. The rubber is preferably crosslinked. It is because it can suppress that abrasives aggregate by giving bridge | crosslinking.

  As the abrasive used in the abrasive, those having a Vickers hardness in the range of 1000 to 5000 Hv can be used. Preferably it is in the range of 1000 to 3000 Hv. This is because if the Vickers hardness of the abrasive is 1000 Hv or more, the impact due to the collision of the abrasive grains with the coating is sufficiently applied. Moreover, if it is 5000 Hv or less, the surface of the mold base of the glass mold is hardly damaged.

 Specifically, alumina (Vickers hardness: 3000 Hv) and / or silica (Vickers hardness: 1400 Hv) may be used as the material of the abrasive grains.

  The particle diameter of the abrasive grains is not particularly limited, but preferably 1 to 10 μm, more preferably 1 to 5 μm. This is because the coating can be efficiently removed if the particle size of the abrasive is 1 μm or more. Moreover, if it is 10 μm or less, the surface of the mold base part of the glass mold is hardly damaged. The abrasive grains having the same particle diameter or different particle diameters may be used.

  The particle diameter of the abrasive comprising the rubber and abrasive grains is preferably 500 to 3000 μm, and more preferably 500 to 1500 μm. This is because if the particle size of the abrasive is 500 μm or more, the abrasive can sufficiently adhere to the coating and effectively peel off the coating. Moreover, if it is 3000 micrometers or less, it is because a film can be removed efficiently, even if micro processing of micron order etc. is given to the mold base-material part surface of a glass mold. The abrasive particles having the same particle diameter may be used, or those having different particle diameters may be used.

  The ratio of the abrasive grains in the abrasive can be appropriately changed according to the type of the base material, the film, the blasting conditions, etc., and is not particularly limited, but is preferably 10 with respect to the volume of the entire abrasive. It is good to contain in the range of -90%. More preferably, it is in the range of 20 to 60%. This is because if the ratio of the abrasive grains in the abrasive is 10% or more with respect to the volume of the entire abrasive, impact due to the collision of the abrasive grains with the coating is sufficiently applied. Further, if it is 90% or less, the surface of the mold base part of the glass mold is hardly damaged.

  Moreover, the ratio of the abrasive grains in the abrasive may be the same or a mixture of different ratios may be used.

  The abrasive can be produced by, for example, extrusion molding.

  When producing an abrasive by extrusion molding, it is preferable to first knead rubber and abrasive grains using a kneader. At this time, various fillers such as an inorganic filler and a crosslinking agent may be added.

  The kneaded material adjusted by the kneading operation is pushed out from the kneader and taken out. At this time, it may be formed into a pellet by a pelletizer. The kneaded product formed into a pellet can be cross-linked as necessary, frozen with liquid nitrogen, and then pulverized using a pulverizer or the like to obtain a particulate abrasive.

  Next, the structure of a glass mold that is blasted using the abrasive obtained as described above will be described.

  The glass mold has a mold base portion and a laminated structure as basic components. The mold base portion forms a mold body. A transfer surface that can transfer a desired shape to the molding material is usually formed on the surface of the mold base. Further, a laminated structure composed of at least one layer is provided on the transfer surface of the mold base portion surface.

  A release coating may be provided on the outermost surface of the glass mold as a function for promoting release from the glass. Specific examples of the release coating material include Ir, Ir alloy, diamond-like carbon (DLC), Pt, Pt alloy, Pd, Pd alloy, TiC, TiN, TiCN, (TiAl) N, and (TiCr). ) N, Cr / CrN, Cr / TiN, and the like. These may be contained alone or in combination of two or more.

  From the viewpoint of releasability, an Ir-containing film or a diamond-like carbon film is preferably used. Specific examples of the Ir-containing film include an Ir film, an Ir-Pt film, and an Ir-Re film from the viewpoint of excellent releasability.

  The said release film may be formed just on the type | mold base-material part surface. Further, a diffusion preventing film or a bond film may be provided under the release film.

  The diffusion-preventing coating is preferably provided immediately below the release coating. Basically, among the mold base material component and the bond coating component, the moldability is adversely affected, and the diffusion preventing coating is adhered to the molded product. It is only necessary to prevent the diffusion of at least one component that would reduce the commercial value of the molded product when mixed.

  Specifically, as such a component, for example, Ti, Cr, Fe, Co, Ni, Ta, W, etc., which may be included in the mold base portion, Ti which may be included in the bond film, Examples of the components include Cr, Fe, Co, Ni, Cu, Ag, Ta, W, and Au.

  Specific examples of the material for the diffusion barrier coating include at least one metal selected from Nb, Mo, Ru, Rh and Ta and / or an alloy containing one or more of these metals. it can. Preferably, Rh is good.

  Moreover, the said bond film is good to be provided between the type | mold base material part and the diffusion prevention film, and has mainly the function to couple | bond both.

  Specific examples of the material of the bond coating include at least one metal selected from Cr, Co, Ni, Cu, Ag and Au and / or an alloy containing one or more of these metals. Can do. Au is preferable.

  And as for the said laminated structure, the number of the lamination | stacking will not be specifically limited if the film of at least 1 layer or more is formed.

  The method for forming the laminated structure is not particularly limited. For example, chemical vapor deposition (CVD) such as physical vapor deposition (PVD), thermal CVD, plasma CVD, such as sputtering, vacuum deposition, ion plating, MBE, and laser ablation It may be formed by a vapor phase method such as, a plating method such as electrolytic plating or electroless plating, a liquid phase method such as an anodic oxidation method, a coating method, or a sol-gel method. Each layer may be formed using the same method, or may be formed using different methods.

  Although the material of the said mold base part is not specifically limited, Specifically, for example, WC-based cemented carbide, glassy carbon, stainless steel, ceramics made of Si and a composite thereof, and the like are exemplified. be able to. From the viewpoint of excellent durability and heat resistance, WC cemented carbide, ceramics, and the like are preferable.

  In the present invention, the coating material is removed by blasting the surface of the mold base of the glass mold using the abrasive.

  The blasting apparatus used for the blasting process of the present invention is not particularly limited, and a general-purpose machine can be used.

  As conditions for the blast treatment, the injection pressure is preferably in the range of 0.01 to 0.5 MPa. More preferably, it is in the range of 0.03 to 0.1 MPa. This is because if the spray pressure is 0.01 MPa or more, the abrasive can sufficiently collide with the surface of the mold base portion of the glass mold. Moreover, if it is 0.5 MPa or less, it is because the injection | pouring speed | rate of an appropriate abrasive | polishing material will be obtained and it will be hard to be damaged to the mold base-part surface of a glass forming die.

  And it is preferable that an injection angle exists in the range of 20-45 degree | times. More preferably, it is in the range of 30 to 45 degrees. If the said injection angle is 20 degrees or more, the number of abrasives which collide with the type | mold base-material part surface of a glass forming die is moderate. Moreover, if it is 45 degrees or less, it can suppress that an abrasive | polishing material bites into the type | mold base-material part surface of a glass forming die. Further, when there is a transfer surface such as an inclination on the surface of the mold base portion, it is possible to remove the coating on the transfer surface by adjusting the spray angle with respect to the transfer surface.

  Further, the injection amount is not particularly limited, and can be appropriately changed according to the type of the blasting apparatus to be used and the coating film.

  Further, the number of coating layers to be removed is not particularly limited. For example, only one outermost coating layer may be removed to leave one or more coating layers on the surface of the mold base portion. The entire surface may be exposed. Preferably, the mold base portion surface is exposed. This is because, if the entire mold base portion surface is exposed, the type of coating to be formed is not limited when the glass mold is reused.

  Further, the average roughness Ra of the mold base part surface after the blast treatment is preferably 0.1 μm or less. More preferably, it is 0.07 μm or less. If the average roughness Ra of the mold base part surface after blasting is 0.1 μm or less, the roughness of the mold base part surface hardly affects the film re-formed on the mold base part surface, This is because a good molded body is easily obtained.

  The method for producing a glass mold according to the present invention includes a step of exposing the substrate part surface of the glass mold by the film removing method.

  Moreover, the manufacturing method of the glass mold which concerns on this invention is good to have the process of forming an at least 1 layer or more layer film on the type | mold base-material part surface exposed by the said film removal method.

  The exposed mold base portion may be subjected to a cleaning treatment to remove dust adhering to the surface before forming a film.

  Specific examples of the method for forming the coating include physical vapor deposition (PVD) such as sputtering, vacuum deposition, ion plating, MBE, and laser ablation, thermal CVD, and plasma. Examples include vapor phase methods such as chemical vapor deposition (CVD) such as CVD, liquid phase methods such as electroplating and electroless plating, anodization, coating, and sol-gel. can do. In addition, each layer may be formed using the same method, or may be formed using different methods.

  The thickness of the coating film to be formed is not particularly limited. However, if the thickness is excessively thick, the uneven pattern formed on the surface of the mold base becomes difficult to transfer to the molded product. It is good to change appropriately according to the height.

  Hereinafter, the present invention will be described in detail using examples.

1.1. Preparation of glass mold The mold base part of the glass mold has a plate shape (φ34 mm, plate thickness 5 mm) and a cemented carbide mold (manufactured by Fuji Dice Co., Ltd., “J05”) mainly composed of WC. Using.

1.2. Formation of coating (1)
After cleaning the surface of the mold base part, an Au coating was formed to a thickness of 100 nm directly on the surface of the mold base part by sputtering. Then, an Rh film having a thickness of 300 nm was formed directly on the Au film by plating. Furthermore, an Ir—Pt film made of an Ir—Pt alloy (Ir: 50 wt%, Pt: 50 wt%) was formed to a thickness of 300 nm by sputtering to produce a glass mold. (Hereinafter, this glass mold is referred to as “Ir—Pt film mold (1)”.)

1.3. Formation of film (2)
After cleaning the surface of the mold base part, a diamond-like carbon film having a thickness of 100 nm was formed on the surface of the mold base part by sputtering. (Hereinafter, this glass mold is referred to as “DLC film mold (2)”.)

1.4. Removal of coating The coating formed on the surface of the mold base of the glass mold is blasted with a predetermined abrasive using a blasting machine ("Sirius LDQ-SR-3" manufactured by Fuji Seisakusho). Removed by treatment.

  The blasting conditions were an injection pressure of 0.05 MPa, an injection angle of 30 degrees, an injection amount of 200 g / min, an injection distance of 150 mm, and an injection time of 5 to 20 min.

Example 1
In Example 1, the Ir—Pt film type (1) was sprayed using an abrasive having a particle size of 500 μm in which alumina having an average particle size of 2 μm and a particle size of # 8000 was dispersed in acrylonitrile butadiene rubber (NBR). Blasting was performed for 20 minutes to remove the film.

(Example 2)
In Example 2, the Ir—Pt film type (1) was sprayed using an abrasive having a particle diameter of 500 μm in which alumina having an average particle diameter of 5 μm and a particle diameter of # 3000 was dispersed in acrylonitrile butadiene rubber (NBR). Blasting was performed for 5 minutes to remove the film.

(Example 3)
In Example 3, the Ir—Pt film type (1) was sprayed using an abrasive having a particle diameter of 500 μm in which alumina having an average particle diameter of 5 μm and a particle diameter of # 3000 was dispersed in acrylonitrile butadiene rubber (NBR). Blasting was performed for 10 minutes to remove the coating.

Example 4
In Example 4, the DLC film type (2) was used with an abrasive having an average particle size of 5 μm and a particle size of # 3000 dispersed in acrylonitrile butadiene rubber (NBR), and an injection time of 10 min. The film was removed by blasting.

(Comparative Example 1)
In this comparative example 1, the Ir-Pt film type (1) was subjected to a blasting treatment with an injection time of 20 minutes using an abrasive having a particle diameter of 500 μm made only of acrylonitrile butadiene rubber (NBR), and the film was removed. .

(Comparative Example 2)
In this comparative example 2, the Ir-Pt film type (1) was subjected to a blasting treatment with an injection time of 5 minutes using an abrasive having a particle diameter of 5 μm made only of alumina, and the film was removed.

(Comparative Example 3)
In this comparative example 3, the Ir—Pt film type (1) was subjected to blasting treatment with a spraying time of 5 min using an abrasive having a particle diameter of 5 μm made only of SiC, and the film was removed.

2. Hardness measurement Hardness of cemented carbide molds mainly composed of Ir-Pt coating, diamond-like carbon coating, alumina, SiC, and WC formed on the surface of the mold base of the glass mold is measured according to JIS Z2244. did. At this time, “Nano Hard Nestester NHT” manufactured by Nanotech Co., Ltd. was used as the hardness measuring apparatus. Alumina and SiC were measured in bulk shape before being finely divided into abrasive grains.

  As a result, each Vickers hardness was Ir-Pt coating: 200 Hv, diamond-like carbon coating: 4000 Hv, alumina: 3000 Hv, SiC: 1400 Hv, cemented carbide mold mainly composed of WC: 2040 Hv.

3. Surface Roughness Measurement Using a surface roughness measuring device (Taylor Bobson, “Form Talysurf Series 2”), the average roughness Ra of the surface of the mold base after blasting is measured according to JIS B0601. The surface roughness was evaluated. Moreover, average roughness Ra of the mold base part surface before forming a film was 0.030 micrometer.

4). Film removal evaluation The surface composition of the mold base after blasting was analyzed using an energy dispersive X-ray analyzer (EDX) (Hitachi, Ltd., “E-MAX”), and the film was removed. Evaluated whether or not. The case where only W, C, and Co derived from the mold base part component were detected was regarded as acceptable. Moreover, since the glass forming die in which the diamond-like carbon film of (Example 4) is formed contains C in both the film and the mold base part component, if the W and Co components are uniformly detected, Passed.

  Table 1 shows the types of glass molds used in Examples and Comparative Examples, blasting conditions, results of surface roughness measurement, and results of film removal evaluation.

  From Table 1, it was found from the results of the surface composition analysis that Ir and Pt were detected in the glass mold according to Comparative Example 1, and the film was not sufficiently removed. This is presumably because the impact due to the collision was not sufficiently applied to the coating because the blast treatment was performed using an abrasive made of acrylonitrile butadiene rubber alone.

  In addition, the average roughness Ra of the glass mold according to Comparative Example 2 was 0.950 μm, and the glass mold according to Comparative Example 3 was 0.350 μm, which greatly increased the roughness of the mold base portion surface. This is presumably because the surface of the mold base was scratched because it was blasted using an abrasive consisting only of alumina or SiC.

  In contrast, in the glass molds according to Examples 1 to 4, the average roughness Ra was as small as 0.1 μm or less, and an increase in the roughness of the mold base portion surface could be suppressed. Moreover, from the results of the surface composition analysis, it was confirmed that the coating film was removed in the glass molds according to Examples 1 to 4.

  From the above, if the coating formed on the surface of the mold base of the glass mold is removed by blasting using an abrasive in which abrasive grains are dispersed in rubber, the surface of the mold base will be damaged. It was confirmed that it was difficult to attach.

  In addition, a new coating film was formed on the surface of the base part of the glass mold from which the coating film was removed in Examples 1 to 4 under the conditions of “1.2. The mold was regenerated. Then, when the glass material was actually molded using the regenerated glass mold, a glass molded article molded with a new glass mold was obtained.

  As mentioned above, although the film removal method of the glass forming die concerning this embodiment and an example and the manufacturing method of a glass forming die were explained, the present invention is not limited to the above-mentioned embodiment and an example at all. Various modifications can be made without departing from the spirit of the invention.

Claims (6)

A method of removing a film from a glass mold in which at least one layer of a film is formed on the surface of a mold base part,
A method of removing a film from a glass mold, comprising: blasting the surface of the glass mold using an abrasive in which abrasive grains are dispersed in rubber.   The method for removing a film from a glass mold according to claim 1, wherein an Ir-containing film or a diamond-like carbon film is formed on the outermost surface of the glass mold.   The method for removing a film from a glass mold according to claim 2, wherein the Ir-containing film is an Ir film, an Ir-Pt film, or an Ir-Re film.   4. The method for removing a coating film from a glass mold according to claim 1, wherein the abrasive grains are alumina and / or silica.   The surface of the glass mold having at least one layer of film formed on the surface of the mold base is blasted with an abrasive in which abrasive grains are dispersed in rubber to expose the surface of the mold base The manufacturing method of the glass shaping | molding die characterized by having a process.   6. The method for producing a glass mold according to claim 5, further comprising a step of forming at least one layer of film on the exposed mold base part surface.