JP3149636B2 - Press-molding mold for optical glass element, method for producing the same, and press-molding method for optical glass element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing an optical glass element, and more particularly to a method for press-forming an optical glass element with high accuracy and a method for press-forming an optical glass element used in press molding. The present invention relates to a mold and a method for manufacturing the mold.

[0002]

2. Description of the Related Art In order to repeatedly mold a high-precision optical glass element by press molding, the mold material is stable even at high temperatures, has excellent oxidation resistance, is inert to glass, and is pressed. It is necessary to use a material having excellent mechanical strength so that the shape accuracy does not sometimes collapse, but on the other hand, it must be excellent in workability and easy to perform precision processing.

[0003] As a mold material which satisfies the above-mentioned conditions required for the press molding mold of an optical glass element to some extent, a mixed material of titanium carbide (TiC) and a metal (for example, JP-A-59-121126) or ultra Noble metal thin film formed on a hard alloy base material (for example, Japanese Patent Application Laid-Open No. 62-963)
No. 31) is being studied.

[0004]

However, no conventional mold material has been obtained which satisfies all of the above conditions. For example, when a mixed material of TiC and a metal is used as a mold, it is very hard and has excellent mechanical strength, but is inferior in workability and difficult to perform high-precision processing. Further, it has a drawback that it easily reacts with lead (Pb) or an alkali element which is a component of the optical glass element.

[0005] In a mold in which a noble metal thin film is formed on a cemented carbide base material, when the cemented carbide is machined using a diamond grindstone, the diamond grindstone is severely worn, and precise shape machining is difficult. Special processing equipment is required. Further, there is a problem that the processing time is long and the die cost is very high.

As a remedy, a thin film having good adhesion to a base material is formed on a cemented carbide base material, and an electroless Ni-P plating film is formed on the thin film as a film which can be easily processed precisely. A method of forming an alloy thin film as a protective film (for example, Japanese Patent Application Laid-Open No. 3-23230) has been studied.

However, in this method, electroless Ni-P
There is a problem that the heat resistance of the plating film is low and high melting glass cannot be formed.

[0008] As described above, the conventional mold material has not yet satisfied all of the requirements for the mold material described above.

The present invention solves such a conventional problem,
An object of the present invention is to provide a press-molding die capable of repeatedly press-molding a high-melting-point optical glass element having various shapes that could not be realized by conventional grinding.

[0010]

In order to achieve this object, the present invention provides a method for forming a base material comprising a cemented carbide containing WC as a main component, a cermet containing TiC or TiN as a main component, or a WC sintered body. One element is N as a cutting layer
a metal selected from i, Co, and Fe, and the other element is Si, Ti, Cu, Zr, Nb, Mo, Ru, R
A metal selected from h, Pd, Hf, Ta, W, Re, Os, and Ir, and the rest is formed of a ternary alloy thin film composed of P, and then subjected to precision machining by cutting, and then on the processed layer. Pt, Pd, Ir, Rh, Os, Ru, R
Press forming of high melting point optical glass elements having various shapes by producing a mold formed by forming a noble metal based alloy thin film containing at least one metal selected from e, W and Ta. Provide high-melting optical glass elements with a wide variety of shapes that could not be press-formed conventionally by inexpensively and in large quantities by providing a mold and repeatedly molding the high-melting optical glass using this mold. This is what made it possible.

[0011]

According to the present invention, by using a cemented carbide containing WC as a main component, a cermet containing TiC or TiN as a main component, or a WC sintered body as a mold base material, the mold base material has sufficient strength to withstand press forming. In the cutting layer, one element is a metal selected from Ni, Co, and Fe, and the other element is Si, Ti, Cu, Zr, Nb, Mo, Ru, R
A metal selected from h, Pd, Hf, Ta, W, Re, Os, and Ir. The use of a ternary alloy thin film consisting of P has excellent heat resistance and can be precisely cut into a desired shape easily. It was possible to do. Further, Pt, Pd, Ir, Rh, Os, Ru, Re, W, T
By using a noble metal-based alloy thin film containing at least one metal selected from a, fusion with glass is prevented. Therefore, the mold of the present invention satisfies all the necessary conditions required as the mold material described above. By press-molding glass using the mold of the present invention thus produced, it is possible to mass-produce high melting point optical glass elements having various shapes that could not be realized by conventional grinding. Become.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

A cemented carbide having a diameter of 6 mm and a thickness of 10 mm and containing WC as a main component is discharged into a pair of optical glass lens press-molding dies having a concave press surface with a radius of curvature of 1 mm. Roughed by processing.

Next, on the pressed surface, Ni-Mo-P was formed as a cutting layer with a thickness of 15 μm by sputtering. As a Ni-Mo-P sputtering method, first, a Ni-P chip is prepared by plating a Ni chip of 10 mm × 10 mm with a thickness of about 0.5 mm by an electroless plating method, and these chips having a diameter of 6 inches are formed. Forty sheets were arranged on a Mo disk target to form a Ni-Mo-P target, and sputtering was performed.

Next, this Ni-Mo-P film was finished to a very high precision surface by cutting with a diamond cutting tool. By cutting the Ni-Mo-P alloy thin film in this manner, a mold having a concave shape with a radius of curvature of 1 mm, which was conventionally difficult to manufacture by grinding, can be easily obtained.

Next, 3 .mu.m
A Pt-Ir alloy thin film was coated with a thickness of 5 mm to prepare a press mold.

Similarly, another ternary alloy thin film was formed by a sputtering method to produce a press mold. Note For the target can not be formed by an electroless plating method, such as Fe-P, using a compound such as Fe _x P _y in the target.

FIG. 1 is a cross-sectional view of an example of a press-forming die manufactured as described above, in which a Ni—Mo—P alloy thin film is used for a cutting layer. In FIG. 1, reference numeral 11 denotes a Pt-Ir alloy protective film coated on a press surface, 12 denotes a Ni-Mo-P alloy cut film, and 13 denotes a cemented carbide base material.

These molds are set in the press molding machine shown in FIG. In FIG. 2, 21 is a fixed block for the upper die,
22 is an upper mold heater, 23 is an upper mold, 24 is a glass material, 25 is a lower mold, 26 is a lower mold heater, 27 is a lower mold fixed block, 28 is an upper mold thermocouple, and 29 is a lower mold. A mold thermocouple, 210 is a plunger, 211 is a positioning sensor, 212 is a stopper, and 213 is a cover.

Next, a softening point 6 processed into a spherical shape having a radius of 1 mm
A heavy crown-based glass (SK-12) 24 at 13 ° C. is placed on a lower mold 25, and an upper mold 23 is placed thereon. The temperature is raised to 650 ° C. as it is, and about 40 kg / cm ² in a nitrogen atmosphere.
The press pressure is maintained for 2 minutes, and then cooled to 550 ° C. as it is, the molded optical glass element is taken out, and the step of press molding the optical glass element is completed.

At the end of the 10000th press by repeating the above steps, the upper and lower dies 23 and 25 are removed from the press molding machine, the state of the pressed surface is observed with an optical microscope, and the surface roughness of the pressed surface at that time ( RMS values, Δ) were measured to evaluate the accuracy of each mold. These results are shown in (Table 2) to (Table 5). (Table 2) to (Table 5)
What is to be displayed in one table is divided into four tables based on the space of the paper.

Further, as a comparative experiment, an attempt was made to produce a mold having a similar shape using a conventionally used SiC sintered body and a mold in which a Pt thin film was coated on a cemented carbide base material. Processing was not possible due to chipping. Also, for a mold in which a Ni-P film is formed as a cutting layer on a cemented carbide base material by an electroless plating method and a Pt-Ir alloy thin film is coated as a protective film,
Since a mold having a similar shape could be produced, the mold was set in the press molding machine shown in FIG. 2, and the above-described press molding process was repeated to evaluate the same mold accuracy. This result is shown in Table 1.
Shown in

[0023]

[Table 1]

Sample No. In the mold as shown in FIG. 1 in which an electroless Ni—P plating film is formed on the cutting layer and coated with a Pt—Ir alloy thin film, glass adhesion does not occur.
Cracking of the plating film progressed by the press molding a number of times, and the crack was transferred to the lens, so that further press molding was not possible. This is because the heat resistance of Ni—P in the cutting layer is poor,
This is because i-P cannot withstand.

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Table 5]

On the other hand, the sample No. 2-No. In the mold of Example 46, even when repeatedly pressed 10,000 times, the surface state hardly changes, the surface roughness hardly changes from that before pressing, and high-melting glass such as SK-12 is repeatedly press-formed. We can see that we can do it. That is, by press-molding glass using the press-molding die obtained by the method of the present invention, it has become possible to press-mold a large amount of high-melting-point optical glass elements having a shape that is difficult to grind.

As described above, the mold of the present invention satisfies all of the requirements for directly press-molding the above-described high-precision optical glass element, and provides a high-melting-point optical glass element having a shape that could not be produced by molding. It became possible to press-mold in large quantities.

In order to explain the present invention, a cemented carbide containing WC as a main component was used as a base material of a die for press molding in Examples, but a cermet or a WC containing TiN or TiC as a main component was used. Exactly the same results were obtained when the sintered body was used as the base material.

As for the protective film, P
t-Ir was used, but other Pt, Pd, Ir, Rh,
At least one selected from Os, Ru, Re, W, and Ta
Exactly the same results were obtained when a noble metal based alloy thin film containing more than one kind of metal was used.

Further, in this embodiment, the manufacture of a concave mold having a radius of curvature of 1 mm has been described. However, it is possible to machine a mold that is difficult to machine by conventional grinding, for example, a mold such as an axially asymmetric lens or a microprism array. Needless to say,

[0034]

As described above, the present invention uses a cemented carbide, a cermet, and a WC sintered body as a base material in producing a press mold for an optical glass element, and forms a cut layer on the base material. One element is a metal selected from Ni, Co, and Fe, and the other element is Si, Ti, Cu,
Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta,
W is a metal selected from W, Re, Os, and Ir, and the rest is formed of a ternary alloy thin film composed of P and subjected to precision processing by cutting, and then Pt, Pd,
By forming a noble metal-based alloy thin film containing at least one metal selected from the group consisting of Ir, Rh, Os, Ru, Re, W, and Ta, all the necessary conditions required for a glass forming mold material are satisfied, The present invention provides molds for press-molding high-melting optical glass elements of various shapes, and by repeatedly press-molding optical glass using these molds, high-melting optical glass having shapes not obtained by conventional press-molding. The device can be manufactured inexpensively and in large quantities.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a press mold according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a press molding machine used in one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Pt-Ir alloy protective film 12 Ni-Mo-P alloy cutting film 13 Base material 21 Upper block fixed block 22 Upper block heater 23 Upper block 24 Glass material 25 Lower block 26 Lower block heater 27 Lower block Fixed block 28 Upper die thermocouple 29 Lower die thermocouple 210 Plunger 211 Positioning sensor 212 Stopper 213 Cover

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Inoue 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A-6-279036 (JP, A) JP-A-4- 170331 (JP, A) JP-A-3-242335 (JP, A) JP-A-3-50127 (JP, A) JP-A-3-23230 (JP, A) JP-A-62-96331 (JP, A) JP-A-59-121126 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C03B 11/08 C03B 11/00 C04B 41/88

Claims (5)

(57) [Claims] 1. A cemented carbide containing tungsten carbide (WC) as a main component, a cermet containing titanium carbide (TiC) or titanium nitride (TiN) as a main component, or a WC sintered body as a base material. A cutting layer made of a ternary alloy containing phosphorus (P) is provided on the material, and the cutting layer is processed into a desired shape to form a molding surface, and platinum (Pt), Palladium (P
d), iridium (Ir), rhodium (Rh), osmium (Os), ruthenium (Ru), rhenium (R
e) A press-molding die for an optical glass element, wherein a noble metal-based alloy containing at least one metal selected from the group consisting of tungsten (W) and tantalum (Ta) is formed. 2. A ternary alloy thin film containing P, wherein one element is a metal selected from nickel (Ni), cobalt (Co), and iron (Fe), and the other element is silicon (S).
i), titanium (Ti), copper (Cu), zirconium (Z
r), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd),
It is characterized by using a ternary alloy thin film that is a metal selected from hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), and iridium (Ir), with the balance being P. 2. The mold for press-molding an optical glass element according to claim 1. C. A cemented carbide mainly containing tungsten carbide (WC) as a base material, a cermet mainly containing titanium carbide (TiC) or titanium nitride (TiN), or a WC sintered body. Is formed in a thin film, and the thin film is precisely machined into a desired shape by cutting, and then Pt, Pd, I as a protective layer on the thin film.
Production of a press-molding die for an optical glass element, characterized in that a precious metal-based alloy containing at least one metal selected from the group consisting of r, Rh, Os, Ru, Re, W and Ta is formed as a thin film. Method. 4. A ternary alloy thin film containing P, wherein one element is a metal selected from Ni, Co, and Fe, and the other element is Si, Ti, Cu, Zr, Nb, Mo, Ru,
4. The method for producing a press-molding die according to claim 3, wherein a ternary alloy thin film made of a metal selected from Rh, Pd, Hf, Ta, W, Re, Os, and Ir and the balance being P is used. 5. When forming an optical glass element using a high melting point glass having a softening point of 600 ° C. or higher, a cemented carbide whose base material is tungsten carbide (WC) as a main component, titanium carbide (TiC) or titanium On a cermet or a WC sintered body containing nitride (TiN) as a main component, one element is Ni, Co,
Fe is a metal selected from the group consisting of Si,
Ti, Cu, Zr, Nb, Mo, Ru, Rh, Pd, H
f, a metal selected from the group consisting of Ta, W, Re, Os, and Ir, with the remainder forming a ternary alloy thin film composed of P, forming the thin film into a molding surface of a desired shape by cutting, and then forming the thin film. Pt, Pd, Ir, Rh, Os, R
press molding of an optical glass element characterized by using a press molding die for an optical glass element produced by forming a noble metal based alloy thin film containing at least one metal selected from u, Re, W and Ta. Method.