JP2001150452A - Mold for molding resin and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel mold for molding a resin solving various problems like charging properties, mechanical strength and deformation due to the generation of heat at the time of molding in a conventional mold for molding a resin, more precisely, to provide a mold for molding a resin comprising glass or glass ceramics suitable for molding a transparent resin optical member such as a resin lens for spectacles or an optical element lens. SOLUTION: A mold for molding a resin comprises glass or glass ceramics having a volume resistivity of 1×1013 Ωcm or less. The glass has a bending strength of 90 MPa or more and the average coefficient of thermal expansion thereof is 100×10-7 or less at 100-300 deg.C and the glass ceramics has β-quartz represented by LiXAlXSi1-XO2 (0<=X<1) or a β-quartz solid solution as a crystal phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin mold made of glass or glass ceramic and a method for producing the same.

[0002]

2. Description of the Related Art Transparent resin optical members such as resin lenses for eyeglasses and optical element lenses are usually formed using a mold made of chemically strengthened glass or crystallized glass (Japanese Patent Laid-Open No. 9-99444). No., JP-A-62-182134
No.).

[0003] However, the molding die is charged by the electric charge of the resin raw material, whereby dust and the like tend to adhere. Since it is difficult to remove the deposits due to the charging, there is a problem that the cleaning process is complicated. In addition, the residual deposits adhere to the next resin molded body, which causes a defect.

Further, in order to supplement the mechanical strength of the molding die, it is necessary to perform a chemical strengthening treatment such as ion strengthening, which causes a problem that the resin molding process becomes complicated and the production cost increases. .

[0005] Further, there is a problem that the temperature of the molding die rises non-uniformly due to the heat generated at the time of molding, the molding die is deformed by thermal expansion, and the accuracy of the shape of the resin molded body is deteriorated.

[0006]

SUMMARY OF THE INVENTION The present invention solves various problems in conventional resin molding dies, namely, problems of charging properties, problems of mechanical strength, and problems of deformation of the molding die due to heat generation during resin molding. An object of the present invention is to provide a resin molding die. More specifically, an object of the present invention is to provide a resin molding die made of glass or glass ceramics, which is suitable for molding a transparent resin optical member such as a resin lens for eyeglasses and an optical element lens.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the volume resistivity was 1 × 1.
0 ¹³ Ωcm or less, when using glass or glass ceramics with a bending strength of 90 MPa or more for the resin molding die, it is necessary to solve various problems of chargeability, mechanical strength, deformation of the molding die due to heat generation during resin molding. The present invention has been found.

That is, the invention according to claim 1 is 1 × 1
A resin molding die made of glass having a volume resistivity of not more than 0 ¹³ Ωcm.
The resin molding die according to claim 1, which has a bending strength of not less than MPa, and the invention according to claim 3, wherein the glass has an average linear expansion coefficient of 100 to 300 ° C.
The resin molding die according to claim 1 or 2, which is not more than × 10 ^-7 , and wherein the invention according to claim 4 is based on SiO _{2 in} terms of mass percentage in terms of oxide. 50-62% P ₂ O ₅ 5-10% SiO ₂ + P ₂ O ₅ 55-70% P ₂ O ₅ / SiO ₂ 0.08-0.2 Al ₂ O _{3 22~26% Li 2 O 3~5% MgO} 0.6~2% ZnO 0.5~2% CaO 0.3~4% BaO 0.5~4% TiO 2 1-4% ZrO ₂ Made of glass having a composition of _{1~4% As 2 O 3 + Sb} 2 O 3 0~2%, a resin molding die according to any one of claims 1-3.

The invention according to claim 5 is a resin molding die made of a glass ceramic having a glass phase and a crystal phase, wherein the volume resistivity of the glass ceramic is 1 × 1.
0 ¹³ Ωcm or less is a resin molding die, wherein the invention according to claim 6 is the resin molding die according to claim 5, wherein the glass ceramic has a bending strength of 90 MPa or more. The invention according to claim 7, wherein the glass ceramic has an average linear expansion coefficient of 10 to 300 ° C.
The resin molding die according to claim 5 or 6, wherein the temperature is 0 × 10 ⁻⁷ / ° C. or less. The invention according to claim 8 is characterized in that a crystal phase is precipitated in a glass continuous phase by heat-treating raw glass. A resin molding die made of glass ceramics obtained by said method, wherein said glass ceramics has β-quartz or β-quartz solid solution as a crystal phase. The invention according to claim 9 is a resin molding die made of a glass ceramic having Li _x Al _x Si _{1 -X} O ₂ (where 0 ≦ X <1) as a main crystal phase. 9. The ceramic according to claim 8, wherein the ceramics can be obtained by heat-treating raw glass having a composition not in the stoichiometric range of the main crystal phase to precipitate the main crystal phase in a glass continuous phase. Claim: A resin molding die The invention according to claim 0 is the resin molding die according to any one of claims 5 to 9, wherein the raw glass has the composition according to claim 4, and the invention according to claim 11 uses a glass raw material. After melting, shaping, and gradually cooling, the nucleation step is performed at 650 to 750 ° C. for 1 hour or more, and the crystallization step is performed at 750 to 850 ° C. for 1 hour or more. 5-10
The resin molding die according to any one of the above, and the invention according to the twelfth aspect is to melt, mold and slowly cool the glass raw material, and then perform a nucleation step at 650 to 750 ° C. for 1 hour or more. The method for producing a resin molding die according to any one of claims 5 to 11, wherein the crystallization step is heat-treated at 750 to 850 ° C for 1 hour or more.

The volume resistivity, bending strength, average linear expansion coefficient, main crystal phase, composition range, and the like of the glass or glass ceramic constituting the resin molding die of the present invention will be described.

The volume resistivity of the glass and glass ceramic constituting the resin mold of the present invention must be 1 × 10 ¹³ Ωcm or less, more preferably 6 × 10 ¹² Ωc.
m or less. If the volume resistivity of glass or glass ceramics as a resin lens mold is higher than 1 × 10 ¹³ Ωcm, the resin mold is charged and dust and other deposits tend to be formed. For this reason, in particular, in the molding of a transparent resin optical member such as an eyeglass lens, a problem of complicated cleaning process and occurrence of surface defect due to residual deposits is likely to occur. Further, the volume resistivity of the glass constituting the resin molding die of the present invention is 1 × 10
Preferably ¹² [Omega] cm or less, particularly preferably 6 × 10 ^{1 1} Ωcm.

Further, the gas constituting the resin molding die of the present invention is formed as follows.
The volume resistivity of glass or glass ceramics is 1 × 10⁸
If you try to make it smaller than Ωcm,
Glass and glass
Strength, durability, wear resistance, chemical stability of ceramics
Is significantly reduced. Therefore, the resin of the present invention
Glass and glass-ceramic bodies constituting the forming mold
The product resistivity is 1 × 10 ⁸The above is preferred.

The bending strength of the glass and glass ceramic constituting the resin molding die of the present invention prevents the molding die from cracking due to the expansion and contraction stress of the resin during the molding of the resin lens, and the resin lens molding with high dimensional accuracy. In order to enable the above, 90 MPa or more is preferable, 95 MPa or more is more preferable, and 100 MPa or more is particularly preferable. Further, the bending strength of the glass ceramic constituting the resin mold of the present invention is 130M.
It is preferably at least Pa, particularly preferably at least 140 MPa.

Although resin molding always involves a change in temperature, in molding a high-precision optical element made of a transparent resin, in order to obtain a high surface accuracy, the glass ceramic constituting the resin molding die of the present invention is formed. The average coefficient of linear expansion at 100 to 300 ° C. is preferably 100 × 10 ⁻⁷ (/ ° C.) or less, more preferably 45 × 10 ⁻⁷ (/ ° C.) or less. In particular, the average coefficient of linear expansion at 100 to 300 ° C. of the glass ceramic constituting the resin molding die of the present invention is −5.
It can be at least 10 ^-7 and at most 5 10 ^-7 (/ ° C).

A glass ceramic having an extremely small average linear expansion coefficient in the above range can be obtained by heat-treating the raw glass to form SiO ₂ —Al ₂ O ₃ —Li ₂ O in the glass continuous phase.
A crystalline phase of the system can be precipitated. The crystalline phase is
It is preferable that β-quartz or β-quartz solid solution be the main crystal phase. By using β-quartz or β-quartz solid solution as the main crystal phase, the volume resistivity is small and the mechanical strength is good.
A glass ceramic suitable for a mold for molding a transparent resin optical member such as an eyeglass resin lens and an optical element lens can be obtained.

The composition formula of β-quartz or β-quartz solid solution is
As an example, Li _x Al _x Si _1-X O ₂ (where 0 ≦ X <
It can be shown in 1). Here, X = 0, X = 0.
2, X = 0.33 and X = 0.50 correspond to the compositions of β-quartz, petalite, Li-ortholase, β-spodumene, and β-eucryptite, respectively. When the glass ceramic constituting the resin molding die of the present invention is produced by heat-treating the raw glass, the composition of the raw glass is preferably not in the stoichiometric range of the main crystal phase. By selecting the composition of the raw glass out of the stoichiometric range of the main crystal phase and appropriately, the raw glass can be melted at a relatively low temperature and easily vitrified after casting. In addition, a dense glass ceramic having an appropriate crystal morphology by heat treatment can be obtained. When a glass raw material having a stoichiometric composition ratio of the main crystal phase is used, it is necessary to raise the temperature to a relatively high temperature in order to uniformly melt, and it is difficult to vitrify depending on casting, even if a super-quenching method or the like is used. Even if vitrification is possible, pores are likely to be included during crystallization, and it is difficult to obtain dense glass ceramics.

The main crystal phase of the glass ceramic constituting the resin mold of the present invention is represented by a composition formula Li _x Al _x Si _{1 -x} O ₂
Is more preferably in the range of 0 <X <0.6. When X is in the range of 0 <X <0.6, a resin molding die having a small volume resistivity and a good bending strength can be obtained. X is particularly preferably in the range of 0 <X ≦ 0.33. When X is in the range of 0 <X ≦ 0.33, a resin molding die suitable for molding a high-precision optical element made of a transparent resin requiring high surface accuracy can be obtained.

The glass ceramic constituting the resin mold according to the present invention has a suitable volume resistivity by having a crystal phase of a suitably selected type in a glass continuous phase and having a dense form without pores. Demonstrates the characteristics of modulus, mechanical strength (bending strength) and average linear expansion coefficient.

Next, the composition of glass or glass ceramic constituting the resin molding die of the present invention will be described.

The content of the SiO ₂ component is preferably at least 50% in order to maintain good bending strength of the obtained glass and glass ceramics. In addition, the content is preferably 62% or less in order to easily melt and refine the glass and maintain the chemical homogeneity of the product. A more preferable range of the SiO ₂ component is 50% to 60%, particularly preferred range 5
3 to 57%.

The P ₂ O ₅ component has an effect of improving the melting and fining of the glass, and its amount is preferably 5% to 10%. A more preferred range of the P ₂ O ₅ component is 6 to 10%, and a particularly preferred range is
7-9%.

In order to remarkably improve the effect of improving the melt clarity, the amount of SiO ₂ + P ₂ O ₅ is preferably set to 55 to 70%. A more preferred range for the content of SiO ₂ + P ₂ O ₅ is 56 to 65%, and a still more preferred range is 60 to 65%.

In addition, the mass ratio of the P ₂ O ₅ component to the SiO ₂ component is preferably in the range of 0.08 to 0.2. It is more preferably in the range of 0.10 to 0.17, and still more preferably in the range of 0.13 to 0.17.

Al_TwoO_ThreeIngredients are glass and glass ceramic
Glass bending strength, and furthermore, the melting property and devitrification resistance of glass
It is an ingredient that improves the quality, its amount is preferably 22% to 26%
No. Al _TwoO_ThreeA more preferred range for the components is 23-25%.

The Li ₂ O component is a component that affects the volume resistivity of glass and glass ceramics and the melting property of glass, and is a component of β-quartz crystal. The amount of Li ₂ O component is 3 in that the melting property of glass and the homogeneity of the product are good, and in the case of glass ceramics, the desired crystal can be precipitated and the volume resistivity and the coefficient of thermal expansion can be designed to be small. % Or more is preferable. Further, in that the bending strength of glass and glass ceramics can be improved, Li ₂ O
The amount of the component is preferably 5% or less. A more preferred range of li ₂ O component is 3.5 to 4.8%, still more preferably in the range of 3.7 to 4.5%
It is.

The MgO component improves the melting property of the glass,
Along with this, it is a component that improves the homogeneity and bending strength of the product, and its amount is preferably 0.6 to 2%. A more preferred range of the MgO component is 0.7 to 2%, and a particularly preferred range is 0.7 to 1.
4%.

The ZnO component is also a component that improves the melting property of the glass and thereby improves the homogeneity and bending strength of the product, and is preferably 0.5 to 2%. A more preferred range of the ZnO component is 0.5 to 1.7%, and a particularly preferred range is 0.5 to 1.7%.
It is.

The total amount of the three components Li ₂ O + MgO + ZnO is 4.6
More preferably, it is in the range of about 6.5%.

The CaO component is also a component that improves the melting property of the glass and thereby improves the homogeneity and bending strength of the product, and is preferably 0.3 to 4%. A more preferred range for the CaO component is 0.3 to 3%, and a still more preferred range is 0.5 to 2.5%.

The BaO component is also a component that improves the melting property of the glass and thereby improves the homogeneity and bending strength of the product, and is preferably 0.5 to 4%. A more preferred range for the BaO component is 0.5-3%, and a still more preferred range is 0.5-1.5%.

The TiO ₂ component has the effect of lowering the volume resistivity of glass and glass ceramics, and has a role as a nucleating agent for precipitated crystals in glass ceramics together with the ZrO ₂ component. Therefore, the amount of the TiO ₂ component is preferably 1% or more. Further, in order to improve the devitrification resistance, the content is preferably 4% or less. A more preferable range of the TiO ₂ component 1.5 to 4%, particularly preferably 1.5 to 3%.

The ZrO ₂ component has the effect of improving the bending strength of glass and glass ceramics, and has a role as a nucleating agent for precipitated crystals in glass ceramics together with the TiO ₂ component. Therefore, the amount of the ZrO ₂ component is preferably 1% or more. Also, in order to improve the devitrification resistance, it is preferably at most 4%. A more preferred range for the ZrO ₂ component is 1.5-4%, particularly preferably 1-2.5%.

The As ₂ O ₃ and Sb ₂ O ₃ components can be added as a fining agent at the time of glass melting, and the amount is preferably 2% or less. More preferably, it is in the range of As ₂ O ₃ + Sb ₂ O ₃ = 0.3 to ₂ %, particularly preferably 0.3 to 1.5%.

In addition to the above components, for the purpose of improving the melting property and the devitrification property, SrO, SrO, and the like can be used as long as the desired properties of the resin molding die made of glass and glass ceramic of the present invention are not impaired. B ₂ O ₃ , F ₂ , La ₂ O ₃ , Bi ₂ O ₃ , WO ₃ , Y ₂ O ₃ ,
SnO ₂ component up to 2% in total of one or more, CoO, Ni
One or more coloring components such as O, Mn ₂ O ₃ , Fe ₂ O ₃ , and Cr ₂ O ₃ can be added up to a total of 2%.

After the glass material is melted, cast, and slowly cooled, the nucleus forming step is preferably performed at 650 to 750 ° C. for 1 hour or more, and the crystallization step is performed at 750 hours. It can be obtained by performing a heat treatment at ８850 ° C. for 1 hour or more.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described based on Tables 1 and 2. Note that the present invention is not limited to only the following examples.

The volume resistivity is as follows: temperature 20 ° C., humidity 60%.
In accordance with JIS K6911, the flexural strength is measured according to JIS R16
It was measured by the test method of 4-point bending strength of No. 01.

[0038]

[Table 1]

[0039]

[Table 2]

Table 1 (No. 1-1 to No. 1-5) shows examples of the resin lens molding die made of the glass of the present invention.
It is shown together with the volume resistivity, bending strength and average coefficient of linear expansion.

Each of the resin lens molding dies made of the glasses of Examples No. 1-1 to No. 1-5 was prepared by first using an oxide, a carbonate,
After mixing the raw materials such as nitrate and dissolving it at a temperature of about 1450 ° C to 1530 ° C using a normal dissolving equipment and stirring and homogenizing,
It was cast and cooled.

The resin molding die made of the obtained glass is
All have a volume resistivity of 1 × 10 ¹³ Ωcm or less, and 90M
It had a bending strength of Pa or more.

In the resin molding dies made of glass of these examples, there was little electrification of the mold material in the production of the resin lens, and the defect of the resin lens due to adhesion of dust and the like was extremely small. Also, the bending strength was sufficient in manufacturing a resin lens.

Table 2 (No. 2-1 to No. 2-5) shows examples of the resin lens molding die made of the glass ceramic of the present invention.
The results are shown together with the original glass composition (% by mass), the nucleation temperature, the crystallization temperature, the volume resistivity, the bending strength, and the average linear expansion coefficient when these original glasses are subjected to a crystallization treatment.

In each of the resin lens molding dies made of the glass ceramics of Examples No. 2-1 to No. 2-5, first, raw materials such as oxides, carbonates and nitrates are mixed, and this is mixed with a normal material. After melting at a temperature of about 1450 ° C. to 1530 ° C. using a melting apparatus and homogenizing with stirring, casting, cooling, and cooling at a nucleation temperature shown in Table 2
After heat-treating for 5 hours, it was crystallized by heat-treating for 5 hours at the crystallization temperature also shown in Table 2.

Each of the resin molding dies made of glass ceramics had a volume resistivity of 1 × 10 ¹³ Ωcm or less and a bending strength of 90 MPa or more. Also,
According to X-ray diffraction, all of the glass ceramics of Examples No. 2-1 to No. 2-5 are Li _x Al _x Si _{1 -X} O ₂ (where 0 <
X <0.33) was confirmed as a β-quartz solid solution. According to the TEM, all of the glass ceramics of Examples No. 2-1 to No. 2-5 showed a crystal phase of about 40 to 60 ° and a crystal phase of about 500 to 1000 °.

In the resin molding dies made of the glass ceramics of these examples, there was little electrification of the mold material in the production of the resin lens, and the defect of the resin lens due to adhesion of dust and the like was remarkably reduced. Also, the bending strength was sufficient in manufacturing a resin lens.

[0048]

As described above, the resin molding die made of glass or glass ceramic of the present invention is obtained by melting and processing raw glass having a specific composition, and has a low volume resistivity. When molding a resin, it can be used favorably without causing a failure due to charging. In addition, it has sufficient bending strength to mold various lenses and the like. Furthermore, because of its excellent mechanical strength and small thermal expansion coefficient, the resin molding die of the present invention can be suitably used for molding a high-precision optical element made of a transparent resin.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F202 AH73 AJ06 CA30 CB01 CD00 CD30 4G015 EA02 4G062 AA11 BB06 BB09 CC09 DA06 DB04 DC01 DD03 DE02 DE03 DF01 EA03 EB01 EC01 ED02 ED03 EE02 EE03 EF01 EG01 FG01 FC01 FH01 FJ01 FK01 FL01 GA01 GA10 GB01 GC01 GD01 GE01 HH01 HH03 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ04 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM40 NN26 NN33 Q33

Claims (12)

[Claims] 1. A resin molding die made of glass having a volume resistivity of 1 × 10 ¹³ Ωcm or less. 2. The resin molding die according to claim 1, wherein said glass has a bending strength of 90 MPa or more. 3. The glass according to claim 1, wherein the glass has an average linear expansion coefficient at 100 to 300 ° C. of 100 × 10 ⁻⁷ or less.
Or the mold for resin molding according to 2. 4. An oxide-based mass percentage of SiO ₂ 50-62% P ₂ O ₅ 5-10% SiO ₂ + P ₂ O ₅ 55-70% P ₂ O ₅ / SiO ₂ 0.08-0.2 Al ₂ O _{3 22~26% Li 2 O 3~5% MgO} 0.6~2% ZnO 0.5~2% CaO 0.3~4% BaO 0.5~4% TiO 2 1-4% ZrO ₂ Made of glass having a composition of _{1~4% As 2 O 3 + Sb} 2 O 3 0~2%, the resin mold of any one of claims 1 to 3. 5. A resin molding die comprising a glass ceramic having a glass phase and a crystal phase, wherein the glass ceramic has a volume resistivity of 1 × 10 ¹³ Ωcm or less. 6. The glass ceramic has a bending strength of 90MP.
The resin molding die according to claim 5, which is not less than a. 7. The glass ceramic of 100 to 300
The resin molding die according to claim 5, wherein the average linear expansion coefficient at 100 ° C. is 100 × 10 ⁻⁷ / ° C. or lower. 8. A resin molding die comprising a glass ceramic obtained by subjecting a raw glass to a heat treatment to precipitate a crystal phase in a glass continuous phase, wherein the glass ceramic has β-quartz or β-quartz as a crystal phase. The resin molding die according to any one of claims 5 to 7, comprising a quartz solid solution. 9. Li _x Al _x Si _{1 -x} O ₂ (provided that 0 ≦ X <
1) A resin molding die comprising a glass ceramic having 1) as a main crystal phase, wherein the glass ceramic is subjected to a heat treatment of an original glass having a composition not in the stoichiometric range of the main crystal phase to form a glass continuous phase. 9. The resin molding die according to claim 8, wherein said main crystal phase is precipitated therein. 10. The resin molding die according to claim 8, wherein the raw glass has a composition according to claim 4. 11. A glass raw material is obtained by melting, shaping, and slowly cooling, followed by heat treatment in a nucleation step at 650 to 750 ° C. for 1 hour or more and in a crystallization step at 750 to 850 ° C. for 1 hour or more. Made of glass ceramics,
The resin molding die according to any one of claims 5 to 10. 12. The glass raw material is melted, molded, and gradually cooled, and then heat-treated at 650 to 750 ° C. for 1 hour or more in a nucleation step and 750 to 850 ° C. for 1 hour or more in a crystallization step. The method for producing a resin molding die according to any one of claims 5 to 11, wherein