JP2002166425A - Mold duplicating method and property judging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold duplicating method by which numerous long-lived molds can be duplicated and a mold property judging method which it is possible to judge in a short time whether the property of a master mold is acceptable. SOLUTION: The mold duplicating method comprises a vapor-deposited film forming step for forming a vapor-deposited film on the irregular pattern face of a finished product formed by a stamper mold, and an electroforming step for manufacturing a second stamper mold with a reverse irregular pattern formed by electroforming on the irregular pattern face, of the finished product, on which the vapor-deposited film is formed. In the descriped steps, a plating step for plating the reverse irregular pattern of the master mold, a molding step for molding the finished product directly using the master mold and a property judging step for judging the property of the directly molded finished product are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for duplicating a mold suitably used for resin molding of a lens sheet and a method for judging its properties.

[0002]

2. Description of the Related Art There is a method of replicating another mold from a mold using a resin. For example, JP-A-10-
Japanese Patent No. 323839 discloses that a first thermosetting resin is injected into a metal mold (master) provided with a reverse uneven pattern of a molding object, cured, and then released from the resin mold (mother). ), A metal or ceramic plate is laminated on a second thermosetting resin layer obtained by injecting a second thermosetting resin into the resin mold, and a primary curing mold is formed. Further, a method is disclosed in which a primary curing mold is released from the resin mold and then the primary curing mold is secondarily cured to produce a molding die (stamper).

Japanese Patent Application Laid-Open No. 5-156484 discloses that a metal master is transferred by a hot press molding method to form an electroforming mother (mother) made of a conductive resin base material, followed by electroforming. A method for obtaining a Fresnel lens molding die (stamper) from the metal layer electrodeposited on the main surface of the mother die, stacking the die and a transparent thermoplastic resin, and manufacturing a Fresnel lens by a hot press molding method. It has been disclosed.

[0004] Further, in the gazette of Japanese Patent No. 2736561, a.
2 to 0.7 chemical equivalents of anhydride curing agent c. 0.5 of total weight
There is disclosed a resin mold obtained by curing an epoxy resin composition for a resin mold, comprising up to 5% by weight of a thixotropic agent.

[0005]

However, when a resin is used as a mold, the surface of the mold is easily damaged due to troubles during manufacture or the like. In addition, UV as resin for molding
When a curable resin is used, corrosion is likely to occur due to monomers and the like in the UV resin. Therefore, there was a problem that the life of one mold was short.

On the other hand, when a metal plate is cut by a carbide tool such as diamond as a master mold used for manufacturing a lens sheet, the mold itself is large (usually 40).
８０80 inches), it is not easy to produce a plurality of identical master dies by wear of the cutting tool. Therefore, in order to mass-produce lens sheets having the same properties, it is necessary to duplicate many long-life mother dies and stampers from one master mold. In addition, in order to guarantee the properties of the copied stamper, it is also required to determine within a short time that the properties of the master mold do not cause any problem.

Accordingly, the present invention provides a mold duplication method capable of duplicating many long-life molds, and a mold property judging method capable of judging the quality of a master mold in a short time. The purpose is to provide.

[0008]

Hereinafter, the present invention will be described. In the first embodiment of the present invention, from a mother mold having a regular uneven pattern on the surface, the mold of the mold characterized by comprising an electroforming step of manufacturing a stamper having a reverse uneven pattern by electroforming The above problem is solved by a duplication method. Here, the “mother mold” refers to a mold on which a regular uneven surface of a product is formed. Further, the “stamper” is a mold in which a reverse uneven shape of a product is formed using a mother mold, which is used for resin molding of the product.

According to the present invention, since the electroforming process is used for the replication of the mold, it is possible to accurately transfer the regular uneven pattern of the product formed on the surface of the mother mold to the stamper side. .

In a second embodiment of the present invention, a first electroforming step for manufacturing a mother mold having a regular uneven pattern by electroforming from a master mold having a reverse uneven pattern formed on a surface thereof, The above object is attained by a mold duplicating method, further comprising: a second electroforming step of manufacturing a stamper mold having an inverted concavo-convex pattern by electroforming from the mold. Here, the “master mold” refers to a product in which a reverse uneven shape of a product is formed on the surface of a metal original plate. Further, in the present embodiment, the “mother mold” is a product in which the product reverse uneven pattern of the master mold is transferred, and the surface thereof has the regular uneven shape of the product.

According to the present invention, a desired number of mother dies and stamper dies can be obtained while maintaining high precision by appropriately repeating the first electroforming step or the second electroforming step. it can.

In the first embodiment, a plating layer is formed on the surface of the regular uneven pattern formed on the mother mold prior to the electroforming step, or in the second embodiment, the master metal layer is formed before the first electroforming step. It may be configured to include a plating step of forming a plating layer on the surface of the reverse uneven pattern formed on the mold.

With this configuration, the mirror surface condition of the surface of the original die immediately after cutting is protected by the plating layer to prevent the occurrence of fine defects and causes of stains on the product surface caused by dirt. can do.

The first embodiment may further comprise a release film forming step of forming an organic release film on the plating surface of the mother mold prior to the electroforming step after the plating step. After the first electroforming step, the first release film forming step of forming an organic release film on the plating surface of the master mold, and the positive and concave pattern surface of the mother mold before the second electroforming step And a second release film forming step of forming an organic release film.

With this configuration, the master mold and the mother mold, and the mother mold and the stamper can be smoothly separated from each other, thereby avoiding a situation in which the mold is damaged. .

Further, in these embodiments, the stamper may be used for molding a lens sheet. Here, the “lens sheet” refers to a sheet-shaped member having a surface with irregularities formed in a predetermined shape and transmitting or reflecting light to condense or disperse the light in a predetermined direction. As an example of a lens sheet, see JP-A-5-156.
784, a lenticular lens sheet in which a mold for making is introduced in FIG.
There are fly-eye lens sheets, linear Fresnel lens sheets, and the like.

In this way, the invention of the above embodiment can be applied to the replication of a mold used for molding a lens sheet.

In a third aspect of the present invention, a vapor deposition film forming step of forming a vapor deposition film on a concave / convex pattern surface of a product, and a reverse concave / convex pattern by electroforming on the concave / convex pattern surface of the product on which the vapor deposited film is formed. And an electroforming step of manufacturing a stamper.

According to this aspect, since a product whose properties have been confirmed as a lens sheet has already been used as a matrix, and a time-consuming electroforming step only needs to be performed once, a mold having the same properties is used. Can be duplicated in a short time.

In the above embodiment, the product may be a lens sheet.

With this configuration, the invention of the above embodiment can be applied to the replication of a mold used for molding a lens sheet.

According to another aspect of the present invention, there is provided a first electroforming step of manufacturing a mother mold having a regular uneven pattern by electroforming from a master mold having a reverse uneven pattern formed on a surface thereof; In a mold replication process including a second electroforming process of manufacturing a stamper having a reverse uneven pattern by electroforming from the mold, a plating process of plating on the reverse uneven pattern surface of the master mold, and a plating process. A molding step of directly molding a product using the master mold, and a property determining step of determining the property of the directly molded product. To solve the above problem.

According to this aspect, the quality of the master mold is determined by a product formed by further resin molding using a stamper that is normally manufactured twice through a time-consuming electroforming process. Since the product is obtained by resin molding directly from the master mold, the quality of the master mold can be determined within a short time.

In the above embodiment, the product may be a lens sheet.

In this way, the invention of the above embodiment can be applied to the quality judgment of the master mold used for molding the lens sheet.

The operation and the gain of the present invention will be apparent from the embodiments described below.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings.

(First Embodiment) FIG. 1 shows a process diagram of a mold replication method according to a first embodiment of the present invention. Here, first, the length of one side is 1-2 m, and the thickness is 15-20 mm.
The regular irregular shape of the lens sheet is formed on the surface of the rectangular or square metal original plate by cutting, and a mother mold is manufactured. The material of the metal base plate is, for example, aluminum, from the viewpoint of ease of processing and the surface is hardly corroded.
Non-ferrous metals such as copper and brass are preferably used. The cutting operation is performed by setting a metal original plate on a large lathe and rotating it, while engraving the regular uneven pattern of the lens sheet on the surface of the original plate with a carbide tool such as a diamond tool. In this cutting operation, cutting oil is used to prevent wear of the cutting tool. It is necessary to form a large number of regular uneven patterns of a lens sheet having a complicated shape on the surface of one mother mold, and the time required for cutting is extremely long (usually 1 week to 10 days). This is because it is extremely difficult to reproduce a perfect shape.

After the cutting step is completed, the mother die is subjected to a plating step after the cutting oil adhering to its surface is completely removed by a step such as solvent degreasing, alkaline electrolytic degreasing, or ultrasonic degreasing. . In the plating step, a process such as bright nickel plating, nickel plating, or chrome plating is performed for the purpose of protecting the mirror surface of the mother mold surface after cutting and improving corrosion resistance.

After the plating step is completed, an organic release film is formed on the surface of the mother mold for the purpose of facilitating separation after the subsequent electroforming step. As the organic release film, for example, "Nikka Nontack" (registered trademark) manufactured by Nippon Chemical Industry Co., Ltd. is available in the market.

Thereafter, the mother mold is immersed in the electroformed layer, and electroformed until a plating film of nickel or the like is formed to a predetermined thickness (for example, 20 mm or more) on its surface. This electroforming process requires about one week. The plating layer having a predetermined thickness is peeled off from the mother mold, backed with a reinforcing plate as necessary, and repeatedly used as a stamper for resin molding of a product.

In the above first embodiment, since the stamper is manufactured from the mother mold by the electroforming process, the irregularities of the lens surface formed on the mother mold surface can be faithfully transferred to the stamper. In addition, since the material of the stamper is a metal such as nickel, it is less likely to be damaged than a resin mold, and there is no possibility of causing corrosion or the like under the influence of low molecular components in the resin. Further, since the surface of the mother mold immediately after the cutting is protected by the plating layer, the mirror surface state can be maintained. Further, since an organic release film is formed, frictional force and adhesive force are less likely to work in a peeling step after electroforming, thereby preventing a mold from being damaged.

(Second Embodiment) FIG. 2 shows a process diagram of a mold duplicating method according to a second embodiment of the present invention. Here, first, the reverse uneven shape of the lens sheet is formed on the surface of the metal original plate as in the first embodiment, and the master mold is manufactured. The cutting operation and the degreasing step of the cutting oil are the same as in the first embodiment. Thereafter, the master mold is subjected to a plating process. In the plating step, a process such as bright nickel plating, nickel plating, or chrome plating is performed for the purpose of protecting the mirror surface of the master mold surface after cutting and improving corrosion resistance.

The master die after the plating step is subjected to a first organic release film formation on the surface thereof for the purpose of facilitating peeling after the first electroforming step. afterwards,
The master mold is immersed in the electroformed layer, and electroformed until a plating film of nickel or the like is formed to a predetermined thickness (for example, 20 mm or more) on its surface. This electroforming process requires about one week. The plating layer having a predetermined thickness is peeled from the master mold. This plating layer has a regular uneven shape of the lens sheet formed on the surface, and is called a mother mold.

The mother die manufactured in the first electroforming step is subjected to a second organic release film formation on the surface thereof for the purpose of facilitating peeling after the second electroforming step. Will be

Next, a second electroforming step is performed based on the mother mold, and electroforming is performed until a plating film of nickel or the like is formed on the surface to a predetermined thickness (for example, 20 mm or more). This electroforming step also requires about one week. The plating layer having a predetermined thickness is peeled from the mother mold. The plated layer has a lens sheet having a reverse uneven shape formed on the surface, is backed by a reinforcing plate as needed, and is repeatedly used as a stamper for resin molding of a product.

In the second embodiment, since the mother mold is manufactured from the master mold and the stamper is manufactured from the mother mold by the electroforming process, the unevenness of the lens surface formed on the surface of the master mold is reduced. It can be faithfully transferred to the stamper. Also, by repeating the first electroforming and the second electroforming as appropriate, a desired number of mother dies and stampers can be manufactured from the same master (that is, a lens surface having the same properties), and This can contribute to mass production of lens sheets. Further, since the material of the stamper is a metal such as nickel, it is less likely to be damaged as compared with a resin mold, and there is no possibility of causing corrosion or the like under the influence of low molecular components in the resin.

(Third Embodiment) FIG. 3 shows a process chart of a mold replication method according to a third embodiment of the present invention. Here, a product (plastic lens) that has already been confirmed to have good properties as a lens sheet,
Use as a prototype. The details are as follows.

First, nickel, nickel and chromium, ITO, gold or the like is coated on the surface of the plastic lens.
Deposit to a thickness of 000-3000 °. Next, a plating layer having a predetermined thickness (20 mm or more) is formed on the vapor deposition surface by electroforming, and is peeled off. The peeled plating layer has a reverse uneven shape of the lens sheet formed on the surface, and can be backed with a reinforcing plate as necessary, and can be repeatedly used as a stamper for resin molding of a product. Moreover,
Since the properties of the prototype have already been guaranteed, it can be used as a stamper for resin molding a lens sheet having substantially the same properties as the original, which can contribute to improvement in mass productivity.

(Fourth Embodiment) FIG. 4 is a diagram showing a method for determining the quality of a master mold in a short time.
Here, a master mold that has undergone a plating process is directly used for resin molding to obtain a lens sheet as a product. Details of the effect are as follows. That is, as described above, one electroforming step requires about one week. However, in order to finally confirm the quality of the properties of the master mold, it is necessary to inspect the defects by transmitting light through a lens sheet manufactured as a product. Therefore, according to the mold replication method according to the first embodiment or the third embodiment, it takes at least one week to confirm the properties of the master mold. According to the mold duplication method of the second embodiment in which the electroforming step is repeated twice, at least two weeks are required for confirming the properties of the master mold. However, if a product is obtained by the method shown in FIG. 4, since the electroforming step is not performed, the property of the product can be confirmed within a very short time, that is, the quality of the master mold can be determined. In such a case, it is needless to say that the master mold can be used again in the electroforming step after the surface of the master mold is sufficiently cleaned.

The present invention is suitably used for duplicating a lens sheet mold. It is considered that the most used lens sheet is a Fresnel lens sheet.However, the method of the present invention can also be applied to molds such as lenticular lens sheets, fly-eye lens sheets, and linear Fresnel lens sheets. It is suitably used for duplication and property determination. Among these, FIG. 5A shows the shape of a stamper for a lenticular lens sheet, FIG. 5B shows the shape of a stamper for a fly-eye lens sheet, and FIG. 5C shows the shape of a stamper for a linear Fresnel lens sheet. ing.

In each embodiment of the present invention, the master die and the mother die subjected to the electroforming step are then neutralized with a plating solution while completely removing the release film formed before the electroforming by alkali washing. At the same time, and then a new release film is formed again and used again in the electroforming process.

The present invention is not limited to the above-described embodiment, but can be appropriately modified without departing from the spirit or spirit of the invention which can be read from the claims and the entire specification. A method for replicating a mold and a method for determining properties are also included in the technical scope of the present invention.

[0044]

As described above, a method of replicating a mold includes an electroforming step of manufacturing a stamper having a reverse uneven pattern by electroforming from a mother mold having a normal uneven pattern on the surface. If this is the case, the regular concave / convex pattern of the lens sheet formed on the surface of the mother mold can be accurately transferred to the stamper side.

As another method of duplicating a mold, a first electroforming step of manufacturing a mother mold having a regular uneven pattern by electroforming from a master mold having a reverse uneven pattern formed on its surface, A second electroforming step of manufacturing a stamper mold having a reverse uneven pattern by electroforming from the mold, and by repeating the electroforming step, a desired number of mother dies and stamper dies are obtained. Can be obtained while maintaining high accuracy.

Further, a plating layer is formed on the surface of the regular uneven pattern formed on the mother mold prior to the electroforming step, or the surface of the reverse uneven pattern formed on the master mold is formed prior to the first electroforming step. If it is configured to include a plating step of forming a plating layer on the surface, the mirror surface state of the original sheet mold surface immediately after cutting can be protected by the plating layer, thereby preventing the occurrence of a cause of spotting on the lens surface. it can.

Further, the method may further include a release film forming step of forming an organic release film on the plating surface of the mother mold before the electroforming step after the plating step, or may be provided before the first electroforming step after the plating step. A first release film forming step of forming an organic release film on the plating surface of the master mold, and a second step of forming an organic release film on the regular uneven pattern surface of the mother mold prior to the second electroforming step. And the master mold and mother mold, and between the mother mold and the stamper, are smoothly separated, and a situation that damages the mold is avoided. can do.

Further, in these embodiments, if the stamper is used for molding a lens sheet, the invention of the above-described embodiment can be applied to a replication of a mold used for molding a lens sheet.

Also, a vapor deposition film forming step of forming a vapor deposition film on the concave / convex pattern surface of the product, and an electroforming process of manufacturing a stamper having an inverse concave / convex pattern on the concave / convex pattern surface of the product on which the vapor deposited film is formed by electroforming And a mold duplication method comprising a mold, a lens sheet of which properties have already been confirmed as a master mold, and a time-consuming electroforming process may be performed once. Can be duplicated in a short time.

Further, as a method for determining the properties of the master mold, a first electroforming step of manufacturing a mother mold having a regular uneven pattern by electroforming from a master mold having a reverse uneven pattern formed on its surface; In a mold replication process including a second electroforming process of manufacturing a stamper having a reverse concavo-convex pattern by electroforming from the mother mold, a plating process for plating the reverse concavo-convex pattern surface of the master mold, If a molding step of directly molding a product using a plated master mold and a property judgment step of judging the property of a directly molded product are provided, the time-consuming electroforming step is usually performed twice. The quality of the master mold was judged based on the product created by further resin molding using a stamper manufactured through the process. However, since the product is obtained by resin molding directly from the master mold, the quality of the master mold is good. Determination can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a method of determining the quality of a master mold in a short time.

FIG. 5 (A) is for a lenticular lens sheet,
(B) is a diagram showing the shape of a fly-eye lens sheet stamper, and (C) is a diagram showing the shape of a linear Fresnel lens sheet stamper.

Claims (11)

[Claims] 1. A method of duplicating a mold, comprising an electroforming step of manufacturing a stamper having an inverted concavo-convex pattern by electroforming from a mother die having a regular concavo-convex pattern on the surface. 2. The mold according to claim 1, further comprising a plating step of forming a plating layer on the surface of the regular uneven pattern formed on the mother mold prior to the electroforming step. Replication method. 3. After the plating step and before an electroforming step,
3. A release film forming step of forming an organic release film on a plating surface of the mother mold.
The mold duplication method described in the above. 4. A first electroforming step of manufacturing a mother mold having a regular uneven pattern by electroforming from a master mold having a reverse uneven pattern formed on the surface, and further electroforming from the mother mold. A second electroforming step of producing a stamper having an inverted concavo-convex pattern by using the method. 5. The method according to claim 4, further comprising, prior to the first electroforming step, a plating step of forming a plating layer on a surface of the reverse uneven pattern formed on the master mold. Mold replication method. 6. A first release film forming step of forming an organic release film on a plating surface of the master mold after the plating step and prior to the first electroforming step, and A second release film forming step of forming an organic release film on the regular uneven pattern surface of the mother mold prior to the electroforming step. Duplication method. 7. The method according to claim 1, wherein the stamper is used for molding a lens sheet. 8. An electroforming method for forming a vapor deposition film on a concave-convex pattern surface of a product, and an electroforming method for producing a stamper having a reverse concave-convex pattern on the concave-convex pattern surface of the product on which the vapor-deposited film is formed by electroforming. And a method of replicating a mold comprising: 9. The method according to claim 8, wherein the product is a lens sheet. 10. A first electroforming step of manufacturing a mother mold having a normal uneven pattern by electroforming from a master mold having a reverse uneven pattern formed on the surface, and further electroforming from the mother mold. A second electroforming step of manufacturing a stamper having an inverted concavo-convex pattern, and a mold replicating step comprising: a plating step of plating the inverted concavo-convex pattern surface of the master mold; and the plated master A property determination method for a master mold, comprising: a molding step of directly molding a product using a mold; and a property determination step of determining properties of the directly molded product. 11. The method according to claim 10, wherein the product is a lens sheet.