JPH04135808A - Mold for forming optical element and manufacture of optical element using same - Google Patents

Abstract

PURPOSE:To improve releasability without using any releasant and, at the same time, improve the adhesion between glass matrix and a resin layer without applying coupling treatment by the use of a constitution wherein one or two kinds and more of films made of material selected from carbide, nitride and carbon are produced at least on the surface, which comes into contact with resin layer, of mold matrix, with which optical element with the resin layer is formed by replica technique. CONSTITUTION:When resin layer 4 is formed on glass matrix 5 out of ultraviolet-curing resin composition, one or two kinds and more of films made of material selected from carbide, nitride and carbon are produced on the surface, which comes into contact with the resin layer 4, of a mold 2. The resin composition contains 1-7 pts.wt. of silane coupling agent to 100 pts.wt. of the composition. The glass matrix used contains 27wt.% or more of SiO2. As the mold 2, a mold made of mold matrix such as steel or the like, on the surface of which carbide film made of WC, TiC, TaC, VC, ZrC, NbC, SiC, B4C, Mo2C or the like, nitride film made of TiN, CrN, TaN, BN, Si3N4 or the like or carbon film made of amorphous carbon, graphite, diamond-like carbon or the like is formed, is used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a replica molding method in which a fluid raw material such as resin or rubber is poured into a mold to form a desired shape on the surface of a molded product base material. The present invention also relates to a mold used for this purpose, and a method of manufacturing an optical element having an ultraviolet curable resin layer on a glass base material using the mold.

[Prior art] Conventionally, materials such as metal, glass, plastic, and rubber have been used for the molds used in the above-mentioned molding methods. When molding, the resin sticks or adheres to the mold surface and it is difficult to release the molded product, so heat shock method,
Methods such as ultrasonic demolding, mechanical separation, and application of a mold release agent to the mold have been used.

Conventionally, in the production of optical elements having a resin layer made of an ultraviolet curing resin on a glass base material, a silane coupling agent having an organic functional group or a reactive group is applied to the glass base material and treated. A method for improving the adhesion between the glass base material and resin 1 by forming an organic coating film on the glass base material surface via silanol groups due to the presence of water molecules bonded or adsorbed to the material surface. was used.

Further, the mold in contact with the resin layer is made of an oxide such as quartz glass, steel, or an iron-based alloy. It is also believed that the surfaces of these molds are covered with oxides in the air, and water molecules are bonded and adsorbed onto the oxides. Since these water molecules form hydrogen bonds with polar groups such as carboxyl groups, amino groups, and cyano groups in the resin layer, the adhesive force between the mold and the resin layer is strong, and therefore resin leakage into the mold is prevented. This was causing the occurrence of defective products. Therefore, in order to weaken the adhesion between the mold and the resin layer and improve mold releasability, ester-based activators and fluororesin-based mold release agents have been applied.

[Problems to be Solved by the Invention] However, the heat shock method has problems such as deformation, deterioration, and cracking of molded products due to repeated cooling and heating. Furthermore, the ultrasonic demolding method has a problem in that molded products often crack and the yield rate is low. In mechanical separation,
Problems such as deformation of the molded product due to a large force being applied to a part of the molded product, and restrictions on the shape of the molded product because the molded product must be tapered to make it easier to remove from the mold. was there.

In addition, in the coupling treatment of glass base materials, it is difficult to set conditions such as the concentration of the coupling agent in coating methods such as spin cord and dipping, and the rotation or pulling speed of the glass base material, and special equipment is also required. there were.

In addition, methods for improving mold releasability by applying a mold release agent such as fluororesin, silicone resin, fatty acid ester, phosphate ester, etc. to the mold in contact with the resin layer by dipping, etc., do not prevent the surface of the molded product from getting dirty or molding. As the number of times the mold release agent increases, the mold release agent is lost from the mold surface and the mold release effect decreases, resulting in problems such as the need to frequently apply mold release agent J.

Therefore, the first object of the present invention is to provide a mold for molding an optical element with improved mold releasability without using a mold release agent, a method for manufacturing an optical element using the mold, and an optical element manufactured by the method. An object of the present invention is to provide an optical element.

A second object of the present invention is to provide a method for manufacturing an optical element in which the adhesiveness between the glass base material and the resin layer is improved, and an optical element manufactured by the method, without subjecting the glass base material to a coupling treatment. Our goal is to provide the following.

[Means for Solving the Problems] That is, the present invention provides: (1) In a mold for molding an optical element used for forming an optical element having a resin layer by the replica method, at least the surface of the mold base material in contact with the resin layer is , a mold for molding an optical element, characterized in that one or more films selected from carbides, nitrides, and carbon are formed; In the method for manufacturing an optical element in which a resin layer is formed on a base material, one or more films selected from carbides, nitrides, and carbon are formed on the surface of the mold that is in contact with the resin layer; The resin composition is the composition 10
5i0 containing 1 to 7 parts by weight of a silane coupling agent to 0 parts by weight, and the glass base material is 27% by weight or more
(2) A method for manufacturing an optical element characterized by containing (2) and (1) an optical element manufactured by the method.

In the mold for molding an optical element of the present invention, releasability is improved by the mold having a film of carbide, nitride, or carbon formed on the surface of the mold base material.

In the method for manufacturing an optical element of the present invention, glass containing 27% by weight or more of SiO□ is used as the glass base material, and 1%
By containing ~7 parts by weight of the silane coupling agent, the adhesion between the glass base material and the resin M is improved without subjecting the glass base material to a silane coupling treatment.

Furthermore, carbide, which is a material having a property of having low reactivity to a silane coupling agent, that is, a property of having a small adhesive force to a resin layer containing a silane coupling agent because there are few water molecules bonded and adsorbed to the surface; By using a mold with a nitride or carbon film formed on its surface, the mold releasability from the resin layer is improved without performing mold release treatment on the mold.

In the present invention, molds on which a carbide film is formed include WC, TiC, TaC, and VCZ on the surface of the mold base material such as steel.
A film formed of rC, NbC, SiC, B4C, Mo2C, etc. by a film forming method such as ion blating, sputtering, CVD, or vacuum evaporation is used. Preferred in terms of mold releasability are WC, TiC, 5iC1B, and C. For molds with a nitride film formed, a film of TiN, CrN, TaN, BN, Si3N4, etc. is formed on the surface of a mold base material such as steel by a film forming method such as ion blasting, sputtering, CVD, or vacuum evaporation. etc. are used. Also,
A mold on which a 5isN4-SiC film is formed, similar to the above-mentioned carbide or nitride film, can also be used. The mold with a carbon film formed thereon is one in which amorphous carbon, graphite, or diamond-like carbon is deposited on the surface of a mold base material such as steel by a film formation method such as an in-beam scattering method.

In the present invention, as the ultraviolet curable resin, epoxy, urethane, polyester, vinyl, silicone, acrylate such as polyene, etc., and a combination of a monomer or oligomer such as epoxy, polyimide, unsaturated polyester, and a polymerization initiator are used.

In the present invention, as the silane coupling agent, epoxy silane, methacrigoxy silane, isocyanate silane, amino silane, mercapto silane, etc. are used. These silane coupling agents are contained in an amount of 1 to 7 parts by weight per 100 parts by weight of the composition containing the ultraviolet curable resin.

Preferably it is 2 to 5 parts by weight. If the amount of the silane coupling agent is less than 1 part by weight, the adhesion between the glass base material and the resin layer will be reduced, and if it is more than 7 parts by weight, the releasability between the resin layer and the mold will be reduced.

In the present invention, glass containing 27% by weight or more of 5i02 is used as the glass base material in order to improve adhesion to the resin layer. Preferably the 5i02 content is 40
Overlapping % or more. glass. Specifically, the material is BKl
, No. 7 optical glass is used for No. 13.

In addition, the optical element in the present invention includes an aspherical lens, a Fresnel lens, a camera focusing device, a repeating mountain shape as seen in a beam splitter element, a diffraction grating,
It can be applied to applications such as linear encoders where repeated uneven shapes are formed.

[Example] Next, the present invention will be explained in more detail with reference to Examples.

FIG. 1 is a schematic cross-sectional view showing a replica method for forming an aspherical resin layer on a glass surface. 2 is a mold holder, 2 is a mold having a thin film layer made of carbide formed by ion blasting, 3 is a gasket, mold 1
A resin is injected into the gap of the glass lens 5, and light is irradiated from the lens side to harden the resin and form the resin layer 4 on the lens 5. The manufacturing process is shown in FIG. In the manufacturing process using the mold for molding an optical element of the present invention, mold release treatment is not necessary.

A 2 μm thick film of TiN was formed by sputtering on a mold base material made of SOS Al5I420 (product name: Starbac, manufactured by Daido Steel) into an aspherical concave shape with a diameter of 30+ nm, a reference radius of curvature of 50 mm, and a maximum deviation of 100 μm. It was created. Next, ultraviolet light consisting of 40 parts by weight of dicyclopentyloxyethyl acrylate, 20 parts by weight of tris(2-acryloxy) incyanate, 40 parts by weight of polyurethane acrylate, and 2 parts by weight of hydroxyhexylphenyl ketone as an ultraviolet curing agent was applied onto the mold using a dispenser. A cured resin composition is dropped, and an optical glass lens SF6 (containing 27% SLOz) is placed on top of the cured resin composition as a glass base material.
, diameter 33mm, radius of curvature 15.8mm, effective beam diameter 3
A 0 mm convex lens was placed and fixed. Next, light of 320 r+m from an ultra-high pressure mercury lamp was irradiated from the glass base material side for 30 minutes to form a lens having an aspherical resin layer on one side of the glass base material.

The releasability of the lens after molding was very good, with no resin remaining on the mold, and the mold surface maintained its pre-molding condition. Furthermore, no resin peeling from the lens surface occurred. Continued 10
Although molding was performed 0 times, the lens surface had sufficient optical precision, and there was no resin adhesion to the mold surface. Furthermore,
When the adhesion between the glass base material of the lens and the resin layer was evaluated by a tape peeling test (cutting with a razor into 10×10 substrate grids at 1 mm intervals), no peeling of the resin from the lens was observed.

In addition, a resin layer was formed in the same manner as above except that a glass lens treated with a silane coupling agent was used, and the resin layer and TiN coating 5 were formed in accordance with JIS K6849.
When we measured the adhesive breaking force with the IJS type, it was 1.2 kg.
/cm2.

L school plate] Except that the mold was the mold of Example 1 before TiN coating,
When molding was performed under the same conditions as in Example 1, resin remained on the mold surface after the third molding, and when the mold surface was observed under a microscope after 10 moldings, numerous scratches were found on the mold surface. did. Furthermore, when molding continued, resin remained on the scratches on the mold surface, making it necessary to repolish the mold surface.

In addition, a resin layer was formed in the same manner as above except that a glass base material subjected to silane coupling treatment was used, and the adhesive breaking force between the resin layer and the 5IJS type was measured according to JIS K6849. .2 kg/am”.

Specificity λ Molding was carried out under the same conditions as in Example 1, except that the mold was the mold of Example 1 before TiN coating, and a fluororesin was further applied as a mold release agent on the mold by dipping.
Resin remained on the mold at the 12th time, and the optical precision of the molded product surface decreased.

Furthermore, when a mold release agent was applied every time molding was performed, the optical precision of the molded product decreased due to the concentration distribution of the molding agent on the mold surface.

In addition, when the adhesive breaking force between the resin layer and the SOS mold coated with a fluororesin mold release agent was measured according to JIS KB849, the first time it was 4.8 kg/cm2, which was a low value, but the mold release If molding was continued without reapplying the mold release agent, the mold release agent had no effect at 17.8 kg/cm2 at the 10th time.

Same as Example 1, except that a 5K12 optical glass lens (containing 43% SiO2) was used, and 5 parts by weight of γ-methacryloxypropyltrimethoxysilane was added as a silane coupling agent to the ultraviolet curable resin composition. Molding was performed under the same conditions. The manufacturing process is shown in FIG. 4, and the conventional manufacturing process is shown in FIG. 2 for comparison. The manufacturing process of the present invention does not require mold release treatment or treatment of the glass base material with a silane curving agent.

The releasability of the lens after molding was very good, with no resin remaining on the mold surface and no resin peeling from the lens surface. Molding was subsequently performed 100 times, but the lens surface maintained sufficient optical precision, and no resin residue was observed on the mold surface. Furthermore, when the adhesion between the glass base material and the surface resin layer was evaluated by a tape peeling test in the same manner as in Example 1, no resin peeling from the lens surface was observed.

In addition, according to JIS K6849, the resin layer and TiN coating S
When we measured the adhesive breaking force with the US type, it was 3.1 kgf.
/am2.

A 2 x 10 - 'Torr, argon gas flow rate 30S
After ionizing argon using CCM, a graphite plate was sputtered at an accelerating voltage of 800 cm to form a carbon thin film of 0.5 μm thick consisting of Murakami amorphous carbon, graphite, and diamond-like carbon (WCC type material). Molding was carried out under the same conditions as in Example 1, except that the mold was changed as described above and 2 parts by weight of γ-methacryloxybrobyltrimethoxysilane was added as a silane coupling agent to the ultraviolet curable resin composition.

The releasability of the lens after molding was very good, and even after repeated molding for one month, no resin remained on the mirror mold, and no resin peeled off from the lens surface.

In addition, as in Example 1, the adhesive breaking force between the resin layer and the carbon-coated WC mold was measured according to JIS K6849.
It was 2.9 kgf/c+n2.

LfLL FIG. 5 is a schematic cross-sectional view showing a replica method for forming an uneven resin layer on the surface of a glass plate.

1. TiC was deposited on a glass base material with excellent flatness by matrix method ion blasting. A film was formed to a thickness of OLLm, and the pitch length was 1.6μtn, a by dry etching.
? A mold 11 processed into an uneven shape having an i of 0.13 μm was created. Next, an ultraviolet curable resin composition prepared by adding 2 parts by weight of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent to 100 parts by weight of photocurable urethane acrylate (manufactured by Nippon Kayaku) was placed on the mold using a dispenser. A thoroughly cleaned quartz glass plate 14 with a flatness accuracy of 5 newtons or less was placed on top of the resin, and the resin was cured by irradiating it from above with a 40 W/ca" high-pressure mercury lamp for 2 minutes. 12 is a spacer. The diffraction grating made of the resin layer 13 thus formed on the quartz glass plate has a pitch length of 1.6±005 μm and a groove depth of 0.13 μm.
It had excellent molding accuracy of ±0.02 μm. The manufacturing process is shown in FIG. 4, FIG. 3 shows the manufacturing process without mixing a silane coupling agent for reference, and FIG. 2 shows the conventional manufacturing process for comparison.

Next, Cu was deposited to a thickness of 0.15 μm as a reflective film by vacuum evaporation.
By forming a 0.2 μm thick film of SiO□ as a protective film, it became possible to use it as an optical precision scaler.

[Effect of the invention] As explained above in detail, the mold used in the replica method,
By using a mold in which one or more films selected from carbide, nitride, and carbon are formed on the surface in contact with the resin layer of the mold base material, ■ the molded product can be easily released without deforming it. (1) The durability of the mold is improved because it is easy to release from the mold, and (2) the mold is released without using a mold release agent, so the process of cleaning the mold and molded product can be omitted.

In addition, in a method for manufacturing an optical element having an ultraviolet curable resin layer on a glass base material, 1 to 7 parts by weight of a silane coupling agent is blended into the resin layer, and the glass base material contains 27% or more of SiO□. By using a mold made of glass, the surface in contact with the resin layer is coated with one or two films of carbides, nitrides, and carbon that have release properties from the resin layer. Coupling treatment can improve the adhesion between the glass base material and the resin layer.

■Molded products can be easily released from the mold without having to undergo mold release treatment.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a state in which a resin layer is formed on a lens. FIG. 2 is a diagram of a conventional optical element manufacturing process. FIG. 3 is a process diagram for manufacturing an optical element using the mold for molding an optical element of the present invention. FIG. 4 is a process diagram for manufacturing the optical element of the present invention. FIG. 5 is a schematic cross-sectional view showing a state in which an uneven resin layer is formed on the surface of a glass plate. Mold holder mold, gasket, resin layer, glass lens 1, mold 1, spacer, resin layer 1, quartz glass plate.

Claims (1)

[Scope of Claims] (1) In an optical element mold used to form an optical element having a resin layer by the replica method, at least the surface of the mold base material in contact with the resin layer contains carbides, nitrides, and carbon. A mold for molding an optical element, characterized in that one or more films selected from the following are formed. (2) The carbide is WC, TiC, TaC, VC, ZrC, Nb
1 selected from C, B_4C, SiC and Mo_2C
The mold for molding an optical element according to claim 1, wherein the mold is one or more kinds. (3) The mold for molding an optical element according to claim 1, wherein the nitride is one or two selected from TiN, CrN, TaN, BN, and Si_3N_4. (4) The mold for molding an optical element according to claim 1, wherein the carbon is one or more selected from amorphous carbon, graphite, and diamond-like carbon. (5) In a method for manufacturing an optical element in which a resin layer is formed on a glass base material using an ultraviolet curable resin composition using a mold for molding an optical element, the surface of the mold in contact with the resin layer contains carbides, nitrides, and carbon. The resin composition contains 1 to 7 parts by weight of a silane coupling agent based on 100 parts by weight of the composition, and the glass base material contains 27 parts by weight of a silane coupling agent. SiO_2 of weight% or more
A method for manufacturing an optical element, characterized in that it contains. (6) The carbide is WC, TiC, TaC, VC, Z
6. The method for manufacturing an optical element according to claim 5, wherein the material is one or more selected from rC, NbC, B_4C, SiC, and Mo_2C. (7) The method for manufacturing an optical element according to claim 5, wherein the nitride is one or two selected from TiN, CrN, TaN, BN, and Si_3N_4. (8) The method for manufacturing an optical element according to claim 5, wherein the carbon is one or more selected from amorphous carbon, graphite, and diamond-like carbon. (9) A glass base material containing 27% by weight or more of SiO_2, and an ultraviolet curable resin composition 100% on the glass base material.
An optical element having a resin layer formed by curing a composition containing 1 to 7 parts by weight of a silane coupling agent. (10) The optical element according to claim 9, wherein the glass base material is formed from two optical surfaces, and the resin layer has an aspherical shape on at least one optical surface.