JP3164616B2 - Method for producing synthetic resin optical element having refractive index distribution and precursor polymer used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a synthetic resin optical element having a refractive index distribution and a precursor polymer used in the method.

[0002]

2. Description of the Related Art As a synthetic resin optical element having a refractive index distribution, for example, a synthetic resin lens having a refractive index distribution in an optical axis direction for correcting aberration of a spherical lens is known. As a method for producing a material having a refractive index distribution, Japanese Patent Application Laid-Open No. 60-149414 discloses a simple method containing at least two types of monomers having different refractive indices and monomer reactivity ratios when formed into a polymer. Holding the monomer mixture in a vessel, allowing the polymerization reaction to proceed ubiquitously in the mixture, causing the precipitated polymer to settle using gravity and / or inertia,
A method has been proposed in which the entire monomer mixture is made into a gel state, and this is finally heated to complete the polymerization. However, in this method, the polymerization reaction proceeds ubiquitously,
In order to sediment the precipitated polymer by gravity or inertial force, the polymerization reaction must proceed very slowly over a long period of several tens of days, and still have a material with a uniform uniform refractive index distribution surface Cannot be obtained, and improvement in accuracy is required.

JP-A-60-162611 discloses that a surface of a container containing a monomer mixture is irradiated with light or an electron beam in a direction perpendicular to the surface of the container, and a polymerization reaction is caused near the inner wall of the container. Has been proposed, and the resulting copolymer is deposited on the inner wall of the copolymer to make the entire monomer mixture into a gel state, which is finally heated to complete the polymerization. However, even with this method, it is required to make the isorefractive index distribution surface even more uniform and to improve the accuracy.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently producing a synthetic resin optical element having a uniform refractive index distribution surface and a refractive index distribution with high accuracy.

[0005]

According to the present invention, the above object has been achieved by limiting the polymerization initiation reaction in a locational manner, so that the place where the reaction occurs with the progress of the polymerization reaction moves with an increase in the polymerization conversion. . That is, the above-mentioned object is achieved by forming the outer surface portion of the optical element to be manufactured from a precursor polymer and starting and proceeding a polymerization reaction from the surface portion of the precursor polymer.

The precursor polymer of the present invention contains an undecomposed polymerization initiator and constitutes the outer surface of the optical element. In the method for producing a synthetic resin optical element having a refractive index distribution according to the present invention, two plate-like bodies of the precursor polymer are placed at an interval, or the plate-like body and another mold are used. Two or more monomers having different refractive indices and monomer reactivity ratios when formed into a polymer in a space provided at intervals or in the internal space of the pipe-shaped body of the precursor polymer. Is injected from the interface between the precursor polymer and the monomer composition by heating or irradiating light from the outside of the precursor polymer, and then proceeding It is characterized by the following.

The monomer that can be used in the present invention is preferably one that forms a transparent polymer. However, even if the homopolymer tends to be opaque, it becomes transparent when copolymerized. Anything can be used. Examples of such a monomer include compounds having at least one polymerizable double bond such as a vinyl group, an acryl group, a methacryl group, and an allyl group, for example, vinyl chloride, vinyl fluoride, vinylidene chloride, and fluoride. Vinylidene, vinyl acetate, vinyl phenyl acetate, vinyl benzoate, vinyl naphthalene, α-vinyl naphthoate, vinyl compounds such as β-vinyl naphthoate, styrene, α-methyl styrene,
styrene derivatives such as p-chlorostyrene, methyl acrylate, ethyl acrylate, 2,2,2-trifluoroethyl acrylate, benzyl acrylate, phenyl acrylate, acrylate such as naphthyl acrylate, methyl methacrylate, Allyl compounds such as methacrylates such as ethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, benzyl methacrylate, phenyl methacrylate and naphthyl methacrylate, acrylonitrile, methacrylonitrile, allyl benzoate and phenyl allyl ether Further, butadiene, 1,5-hexadiene, vinyl acrylate, vinyl methacrylate, divinyl phthalate, divinyl isophthalate, divinylbenzene, diallyl phthalate, diallyl isophthalate, allyl acrylate, allyl methacrylate Allyl acrylic acid, methacrylic acid β- methacrylate, methacrylic anhydride, diethylene glycol bis allyl ether, diethylene glycol bis allyl carbonate, tetraethylene glycol dimethacrylate, bisphenol A dimethacrylate, trimellitic acid triallyl, triallyl phosphate, triallyl phosphite,
Compounds having two or more polymerizable double bonds such as diphenyldiallylsilane and diphenyldivinylsilane are exemplified.

In the present invention, two or more types of monomers having different refractive indices and monomer reactivity ratios when formed into a polymer from the above-mentioned monomers are used as the target refractive index. What is necessary is just to select so that a rate distribution may be formed.

When two types of monomers are copolymerized, the following four types of growth reactions compete with each other. M ₁ ^. + M ₁ → M ₁ ^. (Reaction rate constant k ₁₁ ) M ₁ ^. + M ₂ → M ₂ ^. (Reaction rate constant k ₁₂ ) M ₂ ^. + M ₁ → M ₁ ^. (Reaction rate constant k ₂₁ ) M ₂ ^. + M ₂ → N ₂ ^. (Reaction rate constant k ₂₂ ) At this time, the monomer reactivity ratio γ is defined by the following equation. γ ₁ = k ₁₁ / k ₁₂ γ ₂ = k ₂₂ / k ₂₁

For example, when the reactivity ratio is selected so that γ ₁ > 1, γ ₂ <1, the monomer M ₁ contains M ₁ ^. For M ₂ ^. It is rich in reactivity than the monomer M ₂ against. That is, the first monomer M ₁ is preferentially polymerized with the polymerization reaction, the monomers M ₁ as the reaction proceeds will decrease., Meaning that the monomer M ₂ starts to gradually many polymerization. Therefore, if the starting point of the polymerization reaction is limited by using monomers having different refractive indices when the polymer is formed and the progress of the reaction is controlled, a refractive index distribution accompanying a change in the monomer composition is formed. .

The precursor polymer may itself be a part of the finally formed optical element, or may simply be a starting point for polymerization. In the former case, two or more monomers are appropriately selected from the viewpoint of the refractive index and the monomer reactivity ratio when the polymer is obtained, and at least one of the monomers is used. The precursor polymer used to form the outer surface of the optical element to be manufactured is manufactured.

In any case, in the present invention, together with one or more monomers necessary for producing a precursor polymer, a polymerization initiator (low-temperature polymerization initiator) required for polymerizing the monomers is used. , A photopolymerization initiator, etc.) and a polymerization initiator that is left undecomposed in the precursor polymer. Conventional additives such as a polymerization modifier and a sensitizer can be added to the composition.

As the polymerization initiator to be contained in the monomer composition for producing the precursor polymer, a polymerization initiator which initiates the polymerization of the monomer and a polymerization initiator which is not involved in the polymerization at this time, And a polymerization initiator necessary for initiating polymerization at the interface of the precursor polymer. For example, a combination of two kinds of pyrolysis polymerization initiators having different pyrolysis temperatures, a pyrolysis polymerization initiator and a photopolymerization initiator, a pyrolysis polymerization initiator and an organic peroxide having copolymerizability can be used. .
Some specific examples of the polymerization initiator that can be used in the present invention are shown below, and may be appropriately selected from these.

The thermal decomposition polymerization initiator includes an organic peroxide and an azo compound. In any case, two or more types having different thermal decomposition temperatures are used, and the polymerization initiator having a lower thermal decomposition temperature is used. Is involved in the production of the precursor polymer, and it must be selected so that the higher thermal decomposition temperature remains in the precursor polymer and helps to initiate the subsequent polymerization at the precursor polymer interface.

As the organic peroxide-based polymerization initiator which can be used, isobutyl peroxide, diisopropyl peroxydicarbonate, dimyristyl peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, di (2- Ethylhexyl) peroxydicarbonate, t-butylperoxyneodecanate, 2,
4-dichlorobenzoyl peroxide, t-butylperoxypivalate, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, t-butylperoxy (2-ethylhexanoate), benzoyl peroxide, t -Butyl peroxyisobutyrate, 1,1-
Bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, cyclohexanone peroxide, t
-Butylperoxyacetate, t-butylperoxybenzoate and the like.

As the azo compound-based polymerization initiator that can be used, 2,2, -azobis (4-methoxy-2,
4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis [2-
(2-imidazolin-2-yl) propane], 1,1 '
-Azobis (cyclohexane-1-carbonitrile) and the like.

The photopolymerization initiator that can be used includes:
4-phenoxydichloroacetophenone, diethoxyacetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, and the like.

Further, an organic peroxide having copolymerizability can be used, and one example thereof is t-butylperoxyallyl carbonate.

The polymerization initiator necessary for the polymerization of the monomer to form the precursor polymer of the present invention is usually added to the monomer composition in an amount of 0.01 to 5% by weight. The amount of the polymerization initiator to be left in the precursor polymer is usually 0.05
10 to 10% by weight, preferably 0.1 to 5% by weight. If this amount is less than 0.05% by weight, the effect of the residual polymerization initiator will not be exhibited, and it will be incomplete to restrict the polymerization initiation reaction locally. In this case, the polymerization initiation reaction and the growth reaction tend to occur rapidly, making it difficult to control the target refractive index distribution.

In order to produce the precursor polymer of the present invention, the above monomer composition is heated to a relatively low temperature to initiate polymerization, and the polymerization reaction is allowed to proceed gradually. .
As a method for producing this precursor polymer, generally, first, a monomer composition containing a monomer, a low-temperature polymerization initiator, a polymerization initiator and a polymerization regulator left in the polymer is heated. The polymerization may be carried out. Further, a monomer composition containing a monomer, a low-temperature polymerization initiator and a polymerization regulator is preliminarily polymerized for about one hour in advance to form a viscous liquid mixture. A method in which a polymerization initiator to be left undecomposed in a precursor polymer such as a polymerization initiator or a polymerization initiator having copolymerizability is added, and the obtained mixture is further polymerized and a method of molding is also preferable. .

The polymerization temperature can be appropriately determined depending on the type of the monomer and the polymerization initiator used, but should be selected so that the polymerization reaction does not proceed rapidly but proceeds gradually. In addition, the polymerization time may be such that the polymerization reaction is not completed, but a polymer having self-shape retention is obtained.
Usually 10 to 30 hours.

When producing a precursor polymer containing a photopolymerization initiator, it is necessary to carry out the polymerization reaction in a dark place in order to prevent the decomposition of the photopolymerization initiator.

Similarly, the polymerization of the monomers constituting the precursor polymer may be carried out by using a photopolymerization initiator to obtain a precursor polymer in which the thermally decomposable polymerization initiator remains.

The precursor polymer of the present invention is formed into a plate or pipe. The molding method is not particularly limited, and a casting method depending on the shape of the precursor polymer to be produced,
A centrifugal polymerization molding method or the like can be applied. When it is desired to form a pipe, a centrifugal polymerization molding method is suitable.
Further, the thickness of the precursor polymer can be appropriately designed according to the size and the refractive index distribution of the optical element to be manufactured.

When an optical element having a refractive index distribution is produced using the precursor polymer of the present invention thus obtained, two plates of the precursor polymer are placed at an interval. Or, in a space where the plate-shaped body and another mold are installed at an interval, or in a pipe-shaped body of the precursor polymer, a space, a refractive index and a monomer when the polymer is formed. A monomer composition containing two or more monomers having different reactivity ratios is injected, and the precursor polymer and the monomer composition are heated or irradiated with light from the outside of the precursor polymer. The polymerization proceeds from the interface with the substance.

When the monomer composition is injected according to the method of the present invention, the inner wall surface of the precursor polymer swells slightly, and the polymer remaining in the precursor polymer upon heating or irradiation with light is irradiated. The initiator acts on the monomer composition, causes a polymerization reaction at the interface between the precursor polymer and the monomer composition, and gradually moves to the place of the polymerization reaction. At this time, the polymerization of the precursor polymer is also completed. Thus, according to the present invention, the polymerization initiation site can be geometrically limited by the production of the precursor polymer as the first step, and the interface between the precursor polymer and the monomer composition as the second step. Since it can be limited to the portion, the equirefractive index surface is formed uniformly.

In the above-mentioned method, when an organic peroxide having copolymerizability is used as a residual polymerization initiator when producing a precursor polymer, the peroxide mainly comprises the precursor polymer. As a copolymerization component with the monomer which is not decomposed and fixed in the polymer. Therefore, when the monomer composition is subjected to a polymerization reaction using the precursor polymer,
There is no diffusion of residual polymerization initiator due to slight swelling of the inner wall,
The initiation point of the second stage polymerization is more precisely defined.

The monomer composition to be injected may contain, if necessary, a polymerization regulator, a polymerization initiator, a sensitizer and the like.

The polymerization temperature and the polymerization time can be appropriately selected according to the type of the monomer and the polymerization initiator used. Further, when using a photopolymerization initiator,
After the photopolymerization, it is preferable to further heat to fix the composition distribution formed by the photopolymerization.

Next, an embodiment of a method for manufacturing an optical element according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a process for producing a cylindrical optical element material of the present invention by heat polymerization. The bottom plug 3 is attached to the lower end of the pipe-shaped precursor polymer 1, the monomer composition 2 is injected into the internal space, and the heating device 4
To initiate and advance the polymerization reaction. The heating device 4 needs to have a configuration capable of equally heating the outer surface of the pipe-shaped precursor polymer 1. In this embodiment, the pipe-shaped precursor polymer 1 swells at the contact portion with the monomer composition 2, and a part of the high-temperature thermally decomposable polymerization initiator remaining in the polymer becomes a monomer. It is in a state that it easily acts on the monomer by dissolving in the body composition 2 or the like. Therefore, when heated by the heating device 4, the polymerization reaction starts at the interface 1A between the pipe-shaped precursor polymer 1 and the monomer composition 2, and the place moves as the polymerization reaction proceeds. The distribution of the monomer composition is generated according to the reactivity ratio of the monomer, and an optical element material having a refractive index distribution is obtained.

FIG. 2 is a cross-sectional view showing a production process of the columnar optical element material of the present invention by photopolymerization. In FIG. 2, the monomer composition 2 injected into the internal space of the pipe-shaped precursor polymer 1 is irradiated with light by the light source 5,
Since light of the same intensity must be irradiated to the same thickness in order to proceed the polymerization uniformly, the optical system is set so that the surface of the pipe-shaped precursor polymer 1 is irradiated with the parallel light 7 vertically. 6 is preferably installed. In this embodiment, the photopolymerization initiator contained in the pipe-like precursor polymer 1 in an undecomposed state is the interface 1A of the swollen precursor polymer.
At the interface 1A, the polymerization reaction starts at the interface 1A by light irradiation, and moves to the center of the polymerization reaction. As the light source, for example, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or the like can be used.

FIG. 3 is a cross-sectional view showing a process for producing the plate-shaped optical element material of the present invention by thermal polymerization. In FIG.
The monomer composition 2 is injected between the plate-like precursor polymer 8 and the glass plate 9 and plugged with the spacer 10. Monomer composition 2
Is a heating device 1 installed below the plate-like precursor polymer 8.
Heated by 1. In this case, the polymerization reaction is started at the interface 8A by the action of the high-temperature thermally decomposable polymerization initiator contained in the precursor polymer and gradually moves toward the glass plate.

[0033]

Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

Example 1 Methyl methacrylate was used as a low-temperature polymerization initiator as t-butylperoxyneodecanate (10-hour half-life temperature 46.
5 ° C.) and 0.2% by weight of n-butyl mercaptan as a polymerization regulator were added and prepolymerized at 60 ° C. for 1 hour to obtain a viscous syrup.

As a high-temperature polymerization initiator,
0.5% by weight of 1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane (10-hour half-life temperature 90 ° C.) was added, and the mixture was poured into a nitrogen-substituted glass tube having an inner diameter of 10 mm and centrifuged. After a polymerization reaction at 60 ° C. for 20 hours by a polymerization molding method, it is taken out of the glass tube and has an outer diameter of 10 μm.
A pipe-shaped precursor polymer having a diameter of 5 mm and an inner diameter of 5 mm was obtained.

Next, a mixture of 80 parts by weight of methyl methacrylate and 20 parts by weight of vinyl benzoate was added to 0.2% by weight of n-butyl mercaptan and 1,1-bis (t-butylperoxy) 3,3,5- Trimethylcyclohexane 0.0
The monomer composition to which 5% by weight was added was injected into the internal space of the pipe-shaped precursor polymer, and heated from the periphery at 80 ° C. for 20 hours and then at 100 ° C. for 10 hours to obtain a cylindrical polymer. Was.

The obtained polymer had a refractive index distribution in which the refractive index gradually decreased from the central axis to the periphery, and was effective as an optical element material. FIG. 4 shows the refractive index distribution of the obtained optical element material.

Example 2 To methyl methacrylate, 0.5% by weight of benzoyl peroxide (10-hour half-life temperature: 74 ° C.) as a thermal decomposition polymerization initiator and 0.2% of n-butyl mercaptan as a polymerization regulator were added.
% By weight and prepolymerized at 70 ° C. for 1 hour to obtain a viscous syrup.

To this syrup was added 0.5% by weight of benzyl dimethyl ketal as an ultraviolet polymerization initiator, and the mixture was poured into a nitrogen-substituted glass tube having an inner diameter of 5 mm. After the reaction, the mixture was taken out of the glass tube to obtain a pipe-shaped precursor polymer having an outer diameter of 5 mm and an inner diameter of 3 mm.

Next, a monomer composition obtained by adding 0.01% by weight of benzyldimethyl ketal to a mixture of 80 parts by weight of methyl methacrylate and 20 parts by weight of vinyl benzoate was injected into the internal space of the pipe-shaped polymer. A resin having a refractive index distribution was formed by uniformly irradiating ultraviolet rays from the periphery using an ultrahigh pressure mercury lamp. Then again 90
Heating at 10 ° C. for 10 hours fixed the composition distribution formed by photopolymerization.

The obtained polymer had a refractive index distribution in which the refractive index gradually decreased from the central axis to the periphery, and was effective as an optical element material.

Example 3 A mixture of 95 parts by weight of methyl methacrylate and 5 parts by weight of t-butylperoxyallyl carbonate was added with 0.5% by weight of t-butylperoxyneodecanate as a polymerization initiator and n-type as a polymerization regulator. 0.2% by weight of butyl mercaptan was added, and prepolymerization was performed at 60 ° C. for 1 hour to obtain a viscous syrup.

The syrup was purged with nitrogen and had an inner diameter of 10 m.
m, and polymerized at 60 ° C. for 20 hours by a centrifugal polymerization molding method, and then taken out of the glass tube to obtain a pipe-shaped precursor polymer having an outer diameter of 10 mm and an inner diameter of 5 mm.

Then, a mixture of 80 parts by weight of methyl methacrylate and 20 parts by weight of vinyl benzoate was added to 0.2% by weight of n-butylmercaptan and 1,1-bis (t-butylperoxy) 3,3,5- Trimethylcyclohexane 0.0
The monomer composition to which 5% by weight was added was injected into the internal space of the pipe-shaped precursor polymer, and heated from the periphery at 80 ° C. for 20 hours and then at 100 ° C. for 10 hours to obtain a cylindrical polymer. Was.

The obtained polymer had a refractive index distribution in which the refractive index gradually decreased from the central axis to the periphery, and was effective as an optical element material.

Example 4 0.5% by weight of t-butylperoxyneodecanate as a low-temperature polymerization initiator was added to methyl methacrylate, and 1,1-bis (t-butylperoxy) 3,3 was used as a high-temperature polymerization initiator.
0.05% by weight of 3,5-trimethylcyclohexane,
0.2% by weight of n-butyl mercaptan was added as a polymerization regulator, and the resulting mixture was poured into a reaction vessel composed of two glass plates and a gasket, reacted at a temperature of 50 ° C. for 20 hours, and heated at a high temperature inside. 3mm thickness where polymerization initiator remains
To obtain a plate-like precursor polymer.

The obtained polymer and a glass plate were placed at an interval of 3 mm (see FIG. 3), and a mixture of 80 parts by weight of methyl methacrylate and 20 parts by weight of vinyl benzoate was mixed with n-butyl mercaptan. 0.2% by weight and 1.1
-A monomer composition to which 0.05% by weight of bis (t-butylperoxy) 3,3,5-trimethylcyclohexane was added was injected at 70 ° C for 20 hours, and then at 100 ° C for 10 hours.
After heating for an hour, the mold was released to obtain a plate-shaped polymer having a refractive index distribution.

Example 5 A mixture was obtained by adding 0.5% by weight of benzyl dimethyl ketal as an ultraviolet polymerization initiator and 0.5% by weight of tert-butyl peroxyneodecanate as a thermal decomposition polymerization initiator to methyl methacrylate. The mixture was poured into a reaction vessel composed of two quartz plates and a gasket, and irradiated with ultraviolet rays from both sides to obtain a plate-like precursor polymer having a thickness of 2 mm in which the pyrolytic polymerization initiator remained.

The obtained polymer and a glass plate were placed at an interval of 3 mm, and methyl methacrylate 80
A monomer composition obtained by adding 0.2% by weight of n-butyl mercaptan and 0.05% by weight of tert-butyl peroxyneodecane to a mixture of 20 parts by weight of vinyl benzoate and 60 parts by weight was added. After heating for 20 hours and then at 90 ° C. for 10 hours, the resultant was released from the mold to obtain a plate-shaped polymer having a refractive index distribution.

[0050]

According to the present invention, when a precursor polymer containing an undecomposed polymerization initiator is used, a synthetic resin optical element having a refractive index distribution can be easily and efficiently manufactured. Further, the time required for the production is conventionally reduced from several tens of days to only 20 to 60 hours, which is remarkably reduced. Furthermore, the resulting optical element has a very uniform isorefractive index surface and high accuracy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a process for manufacturing a cylindrical optical element by thermal polymerization according to the present invention.

FIG. 2 is a cross-sectional view illustrating a process of manufacturing a columnar optical element by photopolymerization according to the present invention.

FIG. 3 is a cross-sectional view illustrating a process of manufacturing a plate-shaped optical element by thermal polymerization according to the present invention.

FIG. 4 is a graph showing a refractive index distribution of a cylindrical optical element obtained in Example 1 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe-shaped precursor polymer 1A interface 2 Monomer composition 4 Heating device 5 Light source 6 Optical system 7 Parallel light 8 Plate-shaped precursor polymer 8A Interface 9 Glass plate 10 Spacer 11 Heating device

Claims (4)

(57) [Claims] 1. A space in which two plates of a precursor polymer containing an undecomposed polymerization initiator are placed at an interval or the plate and another molding die are placed at an interval. Inside, a monomer composition containing two or more monomers having different refractive indices and monomer reactivity ratios when formed into a polymer is heated from the outside of the precursor polymer or A method for producing a synthetic resin optical element having a refractive index distribution, wherein polymerization is started and progressed from the interface between the precursor polymer and the monomer composition by irradiating light. 2. A method according to claim 1, at least one of two or more monomers is identical to the monomer constituting the precursor polymer
A method for producing the synthetic resin optical element according to the above. Wherein the interior space of the pipe-shaped body before precursor polymer containing undecomposed polymerization initiator, the refractive index of when it becomes a polymer and monomer reactivity ratios of two or more different single Inject the monomer composition containing the monomer, start polymerization from the interface between the precursor polymer and the monomer composition by heating or irradiating light from the outside of the precursor polymer, A method for producing a synthetic resin optical element having a refractive index distribution, characterized by proceeding. Wherein the at least one of two or more monomers is identical to the monomer constituting the precursor polymer according to claim 3
A method for producing the synthetic resin optical element according to the above.