JPH01171810A - Manufacture of resin mold having delicate unevenness - Google Patents

Abstract

PURPOSE:To obtain a resin mold more easily than by conventional methods, by selecting a thermosetting resin composition, of which the minimum viscosity and the glass transition temperature after curing have respectively a specified value, as a product master made by forming an uneven pattern having a specified value of functionality on a plane, joining it with a metal plate, heating to harden it and then removing the product master. CONSTITUTION:An addition polymerizable thermosetting resin composition without solvent, which has the minimum viscosity of 1.0X10<2>-3.0X10<3> centipoise at a temperature of or below 100 deg.C and a glass transition temperature of or above 100 deg.C, is arranged on a product master, in which an uneven pattern of a functionality of 0.05mum-1mm is formed on a plane of releasable material, while the thickness from the top of the unevenness is less than 1mm, the resin is heated to be heardened, a metal plate having a smooth plane is contacted with a prehardened resin surface, the addition polymerizable thermosetting resin composition is hardened to be integrated with the metal plate and then a model is released from the metal plate and the resin. In such a manner it is possible to copy a delicate unevenness.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a method for molding plastic molded products having fine functional irregularities on the surface of plastic flat lenses, records, compact discs, optical discs, etc. This invention relates to a simple method for manufacturing a resin mold (=stamper).

[Conventional technology and its problems]

Conventionally, plastic products that have fine functional irregularities on a flat surface are usually produced using metal molds that have the desired irregularities formed on the metal surface using methods such as machining or chemical processing.
This is attached to a normal mold and molded. For example, compact discs are manufactured by uniformly applying photoresist to a desired thickness on a smooth glass substrate, burning a desired pattern onto it with a laser beam, developing it, and then applying hard nickel plating to the surface. .

However, manufacturing metal molds with precise irregularities generally requires special equipment, is expensive, and takes a long time to manufacture the molds. development was desired.

[Means for solving problems]

As a result of intensive research into solving this problem, the inventors of the present invention selected a thermosetting resin composition that is heat resistant and capable of faithfully tracing fine functional irregularities. The present inventors have discovered a method to solve the weaknesses of thermosetting resin compositions by combining them with metal plates, and have completed the present invention.

That is, the present invention provides a product master in which a functional uneven pattern of 0.05 to 1 mm is formed on a flat surface having mold releasability or a flat surface of a removable substance, and a product master having a minimum viscosity of 1 at a temperature of 100°C or less. .0X10"~3, OXIO3
Centiboise, a solvent-free addition-polymerizable thermosetting resin composition with a glass transition temperature of 100°C or higher after curing is placed at a thickness of 1.0 mm or less from the top of the unevenness, and precured until the resin no longer flows by heating. Then, a metal plate having a smooth plane is bonded to the pre-cured resin surface, and the addition polymerization type thermosetting resin composition is cured and integrated with the metal plate, and then the model is separated from the metal plate and the resin. In a preferred embodiment, the product master has a position reference mark portion with a concavo-convex pattern, and the metal plate has a predetermined position reference mark. A thin adhesive layer of the addition polymerizable thermosetting resin composition is formed on the side of the metal plate to be bonded to the resin surface, and fine irregularities are formed. A metal layer having a thickness of 40 mm or less is formed on the surface of a resin mold by electroless plating.

The configuration of the present invention will be explained below.

First, the resin mold of the present invention is usually installed in a mold,
It includes a stamp bar used to give a desired surface shape to a resin molded product.

Plastic molded products suitably manufactured by such a method, and therefore their resin molds, are generally suitable for flat lenses (such as Fresnel lenses) having irregularities of less than 1 mm, particularly irregularities of about 100 to 500 p, less than 0.5 mm. )
Examples include compact discs, optical discs, etc., which have irregularities of about 0.1, such as record boards.

The production of the resin mold composited with the metal plate of the present invention uses a product master with a releasable surface or a removable surface, and a dust-controlled mold that can be controlled by heating, depressurization, etc. as appropriate. A metal plate that is set in a mold, in which a solvent-free liquid thermosetting resin composition is placed, precured to a non-flowing state, and then processed into a predetermined shape as desired to form an adhesive layer. After joining and crimping, curing the resin, and integrating the resin and metal plate, remove the product master, post-cure (completely cure) as necessary, and perform external processing etc. as desired. It is manufactured by

The materials used in the resin mold manufacturing method of the present invention are as follows.

(a), Product master: The target molded product itself, which has an uneven pattern formed on a flat surface, or a model or target molded product manufactured from a material with releasability that can be precisely molded from the target molded product or a material that can be disassembled and removed. It is a mold with a precisely formed surface shape, and the material is thermoplastic such as polyolefin, silicone resin, acrylic resin, epoxy resin, etc. that can withstand temperatures of about 100°C and does not usually contain fillers. It is manufactured from heat, light or room temperature curing resin, metal, glass, etc. For example, in the case of compact discs, optical discs, etc., photoresist is coated on a smooth glass surface to a predetermined thickness using a method such as a spin code method and dried to form a thin layer (usually
An example is one obtained by forming a film with a diameter of about 0.1ρ), baking it with a laser beam, and developing it. In the case of flat lenses, etc., the molded product itself or a polishable resin is machined into the desired surface pattern, or metal is mechanically or chemically processed to produce a mold with the desired surface pattern. Examples include those obtained by transferring a concavo-convex pattern using a resin having mold releasability.

Co., Ltd., metal plate: The thermosetting resin composition that forms the surface layer can faithfully transfer fine uneven patterns, but it lacks long-distance dimensional accuracy and strength, so it is used to compensate for this. Usually, a metal plate with a smooth plane and a thickness of 0.1 mm or more is used. Various metals can be used, but those with good dimensional stability, high strength, and excellent adhesion to the thermosetting resin used are preferred, such as nickel plates, steel plates, stainless steel plates, etc. An aluminum alloy plate or the like is used, and it is particularly preferable to use one processed into a desired shape.

In addition, a thin adhesive layer is formed on the adhesive side of the metal plate with the resin in order to accurately transfer minute irregularities and to better ensure the flatness of the irregularities and positional accuracy over long distances. Alternatively, it is a preferable embodiment to form an adhesive composition layer having stress relaxation properties in order to alleviate the difference in coefficient of thermal expansion between the resin for the resin mold and the metal plate.

(C), solvent-free, unfilled liquid addition polymerizable thermosetting resin composition: 1.0X102 to 3.0X at a temperature of 100°C or less
103 centipoise, preferably 5.0 x 102 to 1.
It is a solvent-free, filler-free addition polymerization type curable resin composition having a glass transition temperature of 100° C. or higher, preferably 120° C. or higher after curing. Specifically, cyanato resin (Special Publication No. 41-1928
, 45-11712, 44-1222.0H-1,
190,184, USP-4,578,439, etc.), cyanate ester-epoxy resin (Japanese Patent Publication No. 46-4111)
2 etc.), cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin (Japanese Patent Publication No. 54-3
0440, 52-31279, USP-4,110,
cyanate ester resins such as 364; bisphenol F type epoxy resins, bisphenol A type epoxy resins,
Polyfunctional epoxy resin made using alicyclic epoxy resin, novolak type epoxy resin, epoxy resin derived from xylylene diamine, epoxy resin derived from diaminodiphenylmethane, and other polyfunctional epoxy compounds; polyfunctional A modified maleimide resin whose main components are a maleimide compound and an epoxy compound, an incyanate compound, etc.; an isocyanate-oxazolidone resin whose main components are an isocyanate compound and an epoxy compound (JP-A-5
Preferred examples include modified 1,2-polybutadiene resins, diallyl phthalate resins, silicone resins, and particularly preferred examples include cyanate ester resins.

Further, since it is necessary to be solvent-free and have a low viscosity, these resins can be used by blending a curable monomer or prepolymer and further blending a curing catalyst.

Curable monomers include polyfunctional (meth)acrylates such as polyfunctional (meth)acrylate, alkyl (meth)acrylate 1, triacryloxyisocyanurate, triacryloxycyanurate, and epoxy (meth)acrylate; Polyfunctional allyl compounds such as diallyl phthalate, divinylbenzene, and trialkenyl isocyanurate; dicyclopentadiene, cyclopentadiene and their prepolymers; aromatic vinyl compounds such as styrene and vinyltoluene; monofunctional epoxy compounds, etc. is exemplified.

Examples of catalysts include those known for each resin and resin composition, such as organic peroxides, azo compounds, imidazole and adducts of carboxylic acids or carboxylic acid anhydrides, tertiary amines, phenols, organic acid metal salts,
Adducts of organic acid metal salts with phenol and bisphenol, inorganic metal salts, metal chelate compounds, organic tin compounds,
Various compounds such as acid anhydrides are exemplified, and particularly in the case of the preferred cyanate ester composition of the present invention, organic peroxides, organic metal salts, metal chelate compounds, organic tin compounds, etc. are suitable. .

The resin mold (stamper) of the present invention is manufactured using the above (a), (5), and (C) as main elements. To explain this manufacturing example using an example of a method for creating a stamper for compact disc injection molding, (1) a set of casting models: a dust-controlled model that can control heating, depressurization, etc. A model with a photoresist pattern formed on a smooth glass plate is set horizontally in a casting mold.

(2) Arrangement of addition polymerizable thermosetting resin: Heat the solvent-free, unfilled, low-viscosity addition polymerizable thermosetting resin composition liquid of the present invention prepared separately in the model at a temperature usually below 100°C. A thin layer (1 to 100 cm) is applied to the base, the pressure inside the system is reduced, the surface is made as smooth as possible by ultrasonic vibration or other methods, and precuring is carried out by heating at a temperature usually below 100°C.

(3) Preparation of metal plate.

A metal plate with a desired thickness, high strength, and smooth surface with excellent dimensional stability is cut into the desired shape, and adhesive is applied to it as thinly as possible (approximately 1 to 100 mm) in a dust-controlled environment. The coating is applied, the surface is made as smooth as possible by ultrasonic vibration or other methods under appropriate reduced pressure, and the coating is precured at a temperature of usually 100° C. or less.

(4) Bonding and curing of metal plates: Hold and align the metal plate prepared in (3) above horizontally on top of the model resin in the casting mold prepared in (2) above. While stacking the metal plates and holding them so that they do not shift, the inside of the casting mold is reduced in pressure, heated, and the metal plates are pressed under low pressure (approximately 1 kg/cnf) to gel the resin. , further raise the temperature and harden.

(5) Removing the composite resin mold, etc.: Remove the model and integrated resin mold from the casting mold,
After removing excess resin attached around the resin mold, the glass plate is peeled off.

At this time, if the adhesive force between the photoresist resin and the resin for the main resin mold is strong, the photoresist is adhered to the obtained composite resin mold side, so this is removed with a resist remover.

Although an example of the method for manufacturing a resin mold (stamper) of the present invention has been described above, the method of the present invention is not limited to the above method.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 [Plastic lens] 400m length made of stainless steel with a lens pattern formed on one side
m, width 400mm, thickness 1mm, height of lens unevenness 1,
A metal plate of Omm was used as a model.

This model was fixed horizontally in a casting mold with the lens pattern surface facing upward, and a frame with a height of 20 mm was created around it.

Also, a 15 mm thick plate made of aluminum alloy was cut to have the same external shape as the plastic lens described above.

On the other hand, 2,2-bis(4-cyanatophenyl)furopane was pre-reacted at 160°C for 3 hours to obtain a liquid prepolymer, and 90 parts by weight of this prepolymer and a tetrafunctional compound derived from metaxylylenediamine were prepared. A liquid thermosetting resin composition (hereinafter referred to as Resin 1) having a temperature of 700 centipoise at 75° C. was prepared by mixing 10 parts by weight of epoxy resin (trade name: Tetrarad, manufactured by Mitsubishi Gas Chemical Company).

Similarly, 70 parts by weight of the same liquid prepolymer as above, 30 parts by weight of a substantially non-quality thermoplastic saturated polyester resin (trade name: Polyester-LP-035, manufactured by Nippon Gosei Chemical Industry Co., Ltd.), and octylic acid. An adhesive composition (hereinafter referred to as adhesive 1) was prepared by mixing 0.05 parts by weight of zinc and dissolving it in methyl ethyl ketone.

The resin 1 prepared above was heated to 60°C and applied to the model surface in a casting mold kept at 60°C, and the inside of the system was heated to 3ωm.
After completely removing air bubbles by reducing the pressure to Hg, the temperature was reduced to 75°C.
The applied resin was allowed to gel for 14 hours.

The thickness of the gelled resin layer is approximately 0 from the top of the lens unevenness.
．． It was 3 mm.

On this gelled resin, adhesive 1 was applied to one side of the aluminum plate prepared above and dried at 110°C for 10 minutes to obtain a metal plate of adhesive layer material with an adhesive layer thickness of 0.15 m + n. After stacking the objects and pressing them with a pressure of 1 kg/ctl and heating at 100°C for 24 hours, remove the model (stainless steel plate) and heat at 170°C for 3 hours to completely harden the resin. A resin mold was obtained by removing excess resin, etc.

The resin mold obtained above is set in a mold to make an injection molding mold, and using this, acrylic resin is heated to a resin temperature of 222.
Injection molded at ℃, injection pressure 72 kg/cut,
A good plastic lens molded product made of acrylic resin was obtained.

Example 2 Regarding the molding of precision surface irregularities at the submicron level,
For convenience, a model was created by the following method, and a resin mold was manufactured and evaluated.

A stamper for a compact disc is placed in close contact with a smooth glass plate, a photoresist solution is applied thereto, and the stamper is kept under reduced pressure to completely remove air bubbles, etc., and then a photoresist film is crimped and photocured. A photoresist film with a layer thickness of 0.1 mm was obtained by peeling it off from the stamper, and this was used as a model, and this model was temporarily glued and fixed horizontally with the uneven surface facing up on a horizontally rotatable table in a casting mold. .

On the other hand, 2,2-bis(4-cyanatophenyl)propane was pre-reacted at 160°C for 3 hours to obtain a liquid prepolymer, and 80 parts by weight of this prepolymer and bisphenol A type epoxy resin (trade name: Epicoat 871) were prepared. , made of Yuka Shell Epoxy ■, epoxy equivalent 390-470,
A liquid thermosetting resin composition (hereinafter referred to as resin 2) having a viscosity of 4 to 9 voids (at, 25°C) and having a temperature of 1.0 x 102 centipoise at a temperature of 75°C was prepared. .

In addition, a 10 mm thick aluminum alloy plate was stamped.
After cutting into a donut plate with the same diameter, one side was precisely polished, and the above-mentioned resin 2 was applied to the polished surface and heated to prevent the resin from flowing.

The resin 2 prepared above was heated to 60°C and dripped onto the surface of the model in a casting mold maintained at 60°C, and while rotating the table, the pressure inside the system was reduced to 3 mmHg to completely remove air bubbles. After applying the resin uniformly, the temperature was set to 75°C to eliminate the fluidity of the applied resin. The thickness of the resin layer was about 50 mm.

On this resin surface that has lost its fluidity, Resin 1 is applied in the same manner as on the polished surface of the aluminum alloy plate prepared above, and dried at 110°C for 10 minutes to form an adhesive layer with a thickness of approximately 50°C.
Layer the metal plates made of resin layer material and apply a pressure of 1
kg/cut and heated at 100℃ for 24 hours, then heated at 170℃ for 3 hours to completely harden the resin, remove excess resin etc. around it, then take it out and apply photoresist. was removed with a release agent to obtain a resin mold (stamper).

When the stamper and resin mold (stamper) were examined using a scanning electron microscope, it was found that the reproduction of fine irregularities was good. In addition, when comparing the dimensional accuracy of long-distance unevenness with a photoresist model, the dimensional tolerance can be explained by a difference proportional to the thermal expansion coefficient of the aluminum alloy plate, and the dimensional accuracy of long-distance is also excellent. It was confirmed that it was.

In addition, when using a thin metal plate, it is necessary to apply the resin layer as thinly and uniformly as possible in order to eliminate the occurrence of distortion.

[Operation and effects of the invention]

As is clear from the detailed description of the invention and the examples, the resin mold produced by the method of the present invention is extremely easy to make (stamper mold) compared to conventional metal cutting and polishing methods, metal plating methods, etc. ) can be manufactured.

Therefore, items that were conventionally only economical for mass-produced products due to expensive molds (stampers) can now be manufactured economically, and this has led to industrial and even It has enormous cultural significance.

Patent applicant: Mitsubishi Gas Chemical Co., Ltd.

Claims (1)

[Claims] 1. A product master in which a functional uneven pattern of 0.05 μm to 1 mm is formed on a flat surface having mold releasability or a flat surface of a removable substance, which has a minimum viscosity of 1 at a temperature of 100° C. or less. .0 x 10^2 to 3.0 x 10^3 centipoise, a solvent-free addition polymerizable thermosetting resin composition with a glass transition temperature of 100°C or higher after curing, with a thickness of 1.0 mm or less from the top of the unevenness. A metal plate having a smooth plane is bonded to the pre-cured resin surface, and the addition polymerization type thermosetting resin composition is cured to bond the metal plate and the metal plate. A method for manufacturing a resin mold having fine irregularities, which comprises removing the model from the metal plate and the resin after integrating them. 2. The manufacturing method according to claim 1, wherein the product master has a position reference mark portion having a functional uneven pattern. 3. The manufacturing method according to claim 2, wherein the metal plate is previously processed into a desired shape. 4. The manufacturing method according to claim 1, wherein the metal plate is formed by forming an adhesive thin layer of the addition polymerizable thermosetting resin composition on the side of the metal plate that is to be bonded to the resin surface. . 5. The manufacturing method according to claim 1, wherein a metal layer having a thickness of 40 μm or less is formed on the surface of the resin mold having fine irregularities by electroless plating.