JP2006235007A - Laminated optical element, laminated diffractive optical element, molding method thereof and optical material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element composition and an optical material which suppress deformation, fracture, cracking of a molded layer itself or breaking on the interface between a substrate and the molded layer and do not cause degradation of an optical performance, wherein the molded layer for exhibiting an optical performance is molded from energy-curable resin, and to provide an optical element, diffractive optical element, laminated optical element and laminated diffractive optical element molded by using the optical element composition and optical material. <P>SOLUTION: The laminated optical element has a plurality of relaxation layers of a low polymerization degree which is molded by using a material of the same kind with the molded layer as an intermediate layer between the molded layer molded from the energy curable resin and the transparent substrate, on at least one side surface of the transparent substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a configuration and material of an optical element used for an optical element such as a refractive optical element and a diffractive optical element, and in particular, an optical element free from defects (cracks, cracks, etc.) due to stress load such as polymerization shrinkage. In particular, the present invention relates to a laminated optical element, a laminated diffractive optical element, a molding method thereof, and an optical material.

  In recent years, from the viewpoint of excellent transferability, productivity, optical properties, etc. of molded products using energy curable resins, relief patterns, staircase shapes, kinoforms using energy curable resins on members such as glass substrates A replica lens integrated with the substrate is used and devised, and there is a diffractive optical element that reduces chromatic aberration by forming a diffraction grating using an energy curable resin on a glass substrate with a mold. (For example, refer to Patent Document 1).

  However, when a layer having a fine shape is directly formed on a glass substrate using an energy curable resin in this way, the shape formed by a stress load due to hardening shrinkage or the like of the molded layer itself is a problem such as cracks due to strain. May be included. The finer the molded shape, the greater the deviation from the design shape due to distortion, cracks, etc., the greater the optical performance (diffraction efficiency, etc.).

Therefore, in the past, as a lens material, a resin having greater flexibility after curing, or by adding a large amount of a crosslinking agent, a softening agent, etc. It has been supported by providing as a layer. Therefore, even if it is a single resin, even a resin having excellent optical properties as a lens material may be abandoned due to brittleness problems, or may be laminated with a different material, made into a hybrid, or a large amount of additives. In some cases, it was necessary to use it in an optical element at the expense of optical characteristics.
JP 2004-126499 A JP 09-127321 A JP 09-127322 A Japanese Patent Laid-Open No. 11-04808 Japanese Patent Laid-Open No. 11-044810 JP-A-60-202128 Japanese Patent Laid-Open No. 03-054217 Japanese Patent Laid-Open No. 03-054206

  In the previous example of the diffractive optical element, in order to obtain a structure having high diffraction efficiency in a wide wavelength range, a material having a relatively low refractive index dispersion and a material having a high refractive index dispersion are combined with each other facing each other. Is configured.

Specifically, in the case of Patent Document 2, BMS81 (n _d = 1.64, ν _d = 60.1: manufactured by OHARA) is used as a material having a low refractive index dispersion, and a plastic optical material is used as a material having a high refractive index dispersion. PC (n _d = 1.58, ν _d = 30.5: Teijin Chemicals) is used. Similarly, in the case of Patent Document 3, LaL14 (n _d = 1.698, ν _d = 55.5: manufactured by OHARA), acrylic resin (n _d = 1.49, ν _d = 57) are used as materials having a low refractive index dispersion. .7), Cytop (registered trademark) (n _d = 1.34149, ν _d = 93.8: manufactured by Asahi Glass Co., Ltd.), a plastic optical material PC (n _d = 1.58, ν _d ) as a material having a high refractive index dispersion. = 30.5: Teijin Kasei).

In the case of Patent Document 4 and Patent Document 5, RC-C001 (n _d = 1.525, ν _d = 50.8: manufactured by Dainippon Ink), PMMA (n _d = 1.4917) as a material having a low refractive index dispersion. , Ν _d = 57.4), BMS81 (n _d = 1.64, ν _d = 60.1: manufactured by OHARA) as a material having a high refractive index dispersion, plastic optical material PC (n _d = 1.58, ν _d = 30.5: Teijin Kasei), PS (n _d = 1.5918, ν _d = 31.1), etc. are used.

  As described above, in an optical element such as a diffractive optical element, the range of optical characteristics such as the refractive index and Abbe number of the material used is severely limited as described above. The shape of the molded diffractive optical element also affects the optical performance. Especially regarding the shape change, due to polymerization shrinkage that occurs when the energy curable resin is cured, stress load due to external environment (temperature, humidity, etc.) after molding, pressure load due to external impact that occurs at the time of mold release, There are many cases where deformation, cracking, cracking, or destruction at the interface between the substrate and the molding layer occurs in the molding layer itself molded on the substrate. Such a result becomes an optical defect, which deteriorates the optical performance.

  Therefore, an object of the present invention is to suppress deformation, cracking, cracking of the molding layer itself that exhibits the optical performance molded by the energy curable resin, or destruction at the interface between the substrate and the molding layer, and reducing optical performance. There are provided a configuration of an optical element, an optical material, an optical element molded thereby, a diffractive optical element, a laminated optical element, a laminated diffractive optical element, and a molding method thereof.

  Therefore, in order to solve the above-described problems, the present invention provides an optical element having the following configuration, a molding method of the optical element, the optical element molded by the molding method, and the molded material by the following material configuration. An optical element is provided.

  In the laminated optical element and laminated diffractive optical element of the present invention, the same kind of material as that of the molded layer is used as an intermediate layer between the molded layer formed of an energy curable resin and the transparent substrate on at least one surface of the transparent substrate. It is a laminated optical element characterized by having a plurality of relaxation layers having a low degree of polymerization formed by use.

  The present invention also provides a laminated optical element characterized in that the molding layer and the relaxation layer described above are integrated with the transparent substrate.

  In the present invention, the polymerization degree of the relaxation layer described above is such that the type and addition amount of the polymerization inhibitor are within the range of 0.0005% to 5% of the total weight ratio, so that the type and addition amount of the polymerization initiator are included. Is contained in the range of 0.005 to 10% of the total weight ratio, so that it is adjusted to be lower than the molding layer, and a laminated optical element having a film thickness of 1 μm to 500 μm is provided. .

  Further, the present invention is characterized in that the above-described optical element is a laminated diffractive optical element in which the diffraction efficiency of a specific order (design order) is increased over the entire use wavelength range.

  The present invention also provides the above-described laminated diffractive optical element and different optical characteristics in the same layer configuration as the above-described laminated diffractive optical element, or different layer configurations and optical characteristics, with the diffractive surfaces facing each other. And a laminated diffractive optical element characterized by being combined.

  The present invention also provides a molding method characterized by molding using the mold when molding the optical element described above.

  The present invention also provides a molding method characterized in that in the molding method described above, a molded product is obtained by thermal polymerization or photopolymerization.

  The present invention also provides an optical material characterized in that a curable resin containing at least a substance having a carbazole skeleton is used as a main material as the material of the optical element described above.

  The present invention also provides the optical material as described above, wherein the main material is a curable resin containing at least N-vinylcarbazole.

  The present invention also provides the optical material as described above, wherein the main material is a curable resin containing at least poly (N-vinylcarbazole).

  The present invention also provides the optical material as described above, wherein the main material is a resin containing at least divinyl adipate as a crosslinking agent.

  The present invention also provides the optical material as described above, which comprises at least N-vinylcarbazole and poly (N-vinylcarbazole), divinyl adipate and a photopolymerization initiator.

  In the present invention, the composition of the optical material is in the range of 5 to 30% by weight of poly (N-vinylcarbazole): 5% to 30% of the total weight ratio of divinyl adipate: Provides optical materials.

  According to the present invention, the stress load applied to the molded layer formed by providing the intermediate layer between the transparent substrate and the molded layer with a relaxation layer containing an appropriate amount of film thickness, polymerization inhibitor, and polymerization initiator as a flat layer. Since the flat layer relaxes and the relaxed layer uses the same type of resin as the molded layer, a laminated diffractive optical element having anti-cracking properties can be realized without substantially changing the optical performance.

  Therefore, even when a highly brittle resin is used, it is possible to form an optical element by using the resin type alone without combining the resin bodies having different properties, and the optical material, the optical material It is possible to realize an optical element molding method using the optical element, an optical element molded by the molding method, and an optical system having the optical element.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  The optical element of the present invention is shown in FIG. That is, the molded layer 13 is molded by the energy curable resin 12 on at least one surface of the transparent substrate 11, and the intermediate layer between the transparent substrate 11 and the molded layer 13 is made of the same material as the molded layer 13. This is a laminated diffractive optical element in which the layer 14 is formed.

  Usually, when manufacturing a replica lens, various lens surfaces such as a prism surface, a lenticular lens surface, and a Fresnel lens surface are directly molded as a molding layer 13 using an energy curable resin 12 on one surface of the transparent substrate 11. . When the molding layer 13 is a single layer or a plurality of layers and is integrated with the transparent substrate 11, the molding layer 13 has a relatively high energy (light, heat, etc.) in order to suppress a change with time due to the internal and external environments after molding. Etc.) is preferably cured. However, at that time, the molding layer 13 generally has a high elasticity and a tendency to become brittle and hard with the degree of curing. Therefore, it is firmly fixed and molded on the substrate by internal stress due to polymerization shrinkage during curing, stress load due to external environment (temperature, humidity, etc.) after molding, or pressure load due to external impact applied during mold release, etc. The formed molded layer 13 is deformed, cracked, cracked, or broken at the interface between the transparent substrate 11 and the molded layer 13.

  In the present invention, the stress applied to the molding layer 13 can be relaxed by the above reason by forming the relaxation layer 14 made of the same kind of material as the molding layer 13 between the transparent substrate 11 and the molding layer 13. It is possible to suppress the occurrence of the problem of the molding layer 13 and prevent the optical performance from deteriorating.

  The thickness of the relaxation layer 14 is not particularly limited but is preferably in the range of 1 to 500 μm. When a fine shape such as a Fresnel lens is formed on the molding layer 13, it is preferably 1 to 100 μm, more preferably 1 to 50 μm. Range. If the thickness of the relaxation layer 14 is less than 1 μm, it is difficult to sufficiently relieve the stress applied from the molding layer 13 to the relaxation layer 14, and conversely, if the thickness is sufficiently thicker than 500 μm, the optical distortion of the relaxation layer 14 itself. In addition, it is difficult to control physical properties such as elastic modulus in the thickness direction.

  Further, the optical characteristics such as the refractive index and Abbe number of the relaxation layer 14 vary depending on the composition of the base resin, the additive, etc., but the optical characteristics preferably do not affect the molding layer 13 that generates a function as a replica lens. It is desirable to adjust to the same optical characteristics as the molding layer 13. Specifically, the refractive index and Abbe number of the molding layer 13 and the relaxation layer 14 are preferably in the range of 1.50 to 1.80 for nd and 13 to 60 for νd, respectively.

  The energy curable resin 12 that forms the molding layer 13 and the relaxation layer 14 is not particularly limited as long as it is a monomer, oligomer, polymer, or the like that contains light (ultraviolet rays, electron beams, etc.), a thermal polymerization initiator, and cure proceeds. Although it is not a thing, For example, what mix | blended monomers and oligomers, such as ester type | system | group, an acryl type | system | group, a vinyl type | system | group, a urethane type | system | group, an amide type | system | group, a silicone type, an epoxy type, a phenol type, a urea type, a melamine type, is mentioned. If necessary, each layer constituting the laminate of the present invention has a crosslinking agent, a polymerization accelerator, a release agent, a sensitizer, a viscosity modifier, a solvent, etc., as long as optical properties such as transparency are not impaired. It is possible to blend. In addition, inorganic / organic hybrid resins and the above-described resins in which inorganic fine particles such as silicon oxide, zirconia oxide, ITO, and tin oxide that do not impair transparency are dispersed can also be used.

  The energy curable resin 12 forming the molding layer 13 and the relaxation layer 14 of the present invention is not particularly limited to the above, but is a crosslinked acrylic resin or a crosslinked vinyl resin from the viewpoint of heat resistance and solvent resistance. Is desirable. The cross-linked acrylic resin and the cross-linked vinyl resin mainly contain 50 to 99% by weight of a cross-linkable monomer and various polymers, and the unsaturated monomer 50 to 1 which may contain the polymer in a dissolved state. It is a resin obtained by polymerizing and curing a mixture consisting of% by weight. The crosslinkable monomer is preferably a monomer having at least two unsaturated ethylene groups in the molecule. For example, crosslinks described in Patent Literature 6, Patent Literature 7, Patent Literature 8, and the like It is also possible to use a crosslinkable monomer in combination. The blending amount of the crosslinking agent is particularly preferably 5.0% or more and 30.0% or less of the total weight ratio. If the addition amount of the crosslinking agent is too large, it causes white turbidity and optical scattering occurs. Therefore, it is more preferably 5.0% or more and 20.0% or less.

  The resin of the relaxation layer 14 according to the configuration of the present invention is the same material as the molding layer 13, and after curing, the degree of polymerization is sufficiently lower than that of the resin of the molding layer 13 and needs to be relatively flexible. The energy curable resin 12 forming the relaxation layer 14 is basically the same type of resin as the molding layer 13, and the difference is that it contains an appropriate amount of a polymerization inhibitor in which the resin of the relaxation layer 14 is adjusted. By adding an appropriate amount of the adjusted light and thermal polymerization initiator so that the degree of polymerization is lower than that of the resin of the molding layer 13, a flexible relaxation layer 14 capable of stress relaxation can be formed. Alternatively, the light or thermal polymerization initiator having a different energy band from the light or thermal polymerization initiator contained in the resin of the molding layer 13 contains the resin of the relaxation layer 14 to adjust the wavelength or temperature of the light source used for irradiation. Thus, a flexible relaxation layer 14 capable of stress relaxation can be formed by optimized light irradiation and heat treatment.

  Specific examples of the polymerization inhibitor include hydroquinone, 2,6-di-t-butyl-p-cresol, 2,2-methylene-bis (4-methyl-6-t-butylphenol), 1,1,3-tris (2- Suitable compounds include phenolic compounds such as methyl-4-hydroxy-5-t-butylphenyl) butane, sulfur compounds such as dilauryl thiodipropionate, phosphorus compounds such as triphenyl phosphite, and amine compounds such as phenothiazine. Can be mentioned. The addition ratio of the polymerization inhibitor to the main monomer component can be appropriately selected according to the light source, the amount of light irradiation, and the amount of oxygen present during molding, additional heating temperature, and coloring after polymerization. Two or more polymerization inhibitors can be used in combination. It can also adjust according to the polymerization degree made into the target of the obtained molded object. The addition amount of the polymerization inhibitor is preferably in the range of about 0.0005 to 5%, more preferably 0.001 to 0.5% by weight, based on the total amount of the resin used.

  Specific examples of the photopolymerization initiator include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 1-hydroxy-cyclohexyl-phenyl-ketone, bis (2, 4,6-trimethylbenzoyl) -phenylphosphine oxide, 4-phenylbenzophenone, 4-phenoxybenzophenone, 4,4′-diphenylbenzophenone, 4,4′-diphenoxybenzophenone, and the like can be mentioned as suitable ones. . In addition, the addition ratio of the photopolymerization initiator with respect to the monomer main component can be appropriately selected according to the light source, the amount of light irradiation, the amount of oxygen present at the time of molding, and the additional heating temperature. Combinations of polymerization initiators can also be used. Moreover, it can also adjust according to the polymerization degree made into the target of the molded object obtained. Regarding the addition ratio of the photopolymerization initiator, the content of the photopolymerization initiator in the entire raw material is preferably selected in the range of 0.005 to 10% of the total weight ratio.

  Examples of the thermal polymerization initiator include azobisoisobutyl nitrile (AIBN), benzoyl peroxide, t-butyl peroxypivalate, t-butyl peroxyneohexanoate, t-hexyl peroxyneohexanoate, t -Butylperoxyneodecanoate, t-hexylperoxyneodecanoate, cumylperoxyneohexanoate, cumylperoxyneodecanoate, etc. can be mentioned as suitable ones. The addition ratio of the thermal polymerization initiator to the monomer main component can be appropriately selected according to the heating temperature and further the amount of oxygen present at the time of molding, and two or more polymerization initiators can be used in combination. I can do it. Moreover, it can also adjust according to the polymerization degree made into the target of the molded object obtained. Regarding the addition ratio of the thermal polymerization initiator, the content of the thermal polymerization initiator in the entire raw material body is preferably selected in the range of 0.005 to 10% of the total weight ratio.

  Moreover, it is also possible to use a photopolymerization initiator or a thermal polymerization initiator properly in each layer because of the superiority of the molding procedure.

Further, the tensile elastic modulus E of the film produced under the same conditions as the relaxation layer 14 formed by curing of the molding material is not generally limited by this value, but is 1.5 to 2.6 × 10. It is preferably in the range of ⁹ Pa (frequency 10 Hz, 25 ° C. ± 2 ° C., film thickness 50 μm), more preferably 1.8 to 2.4 × 10 ⁹ Pa (frequency 10 Hz, 25 ° C. ± 2 ° C., film thickness). 50 μm) is desirable.

  As a molding order of the layers to be the optical elements, after forming the relaxation layer 14 on at least one surface on the transparent substrate 11, the molding layer 13 is molded on the relaxation layer 14.

  An outline of a mold for producing a compact is shown in FIG. An outline of the molding method of the molded body is shown in FIG.

  As a mold for molding an optical element, a mold 21 (FIG. 2A) corresponding to a target lens surface shape, for example, a shape having a planar structure, and a mold 22 corresponding to a shape having a diffraction grating (FIG. 2 [FIG. b]). As a molding method, for example, when the cross-linked vinyl resin is used for forming the molding layer 13 and a mixture of the same vinyl resin and an optimized polymerization inhibitor is used to form the relaxation layer 14, the relaxation layer 14 exhibiting fluidity. First, an appropriate amount of the resin is dropped onto the mold 21. Polymerization is performed while the prescribed transparent substrate 11 is pressed from above the resin of the relaxation layer 14 dropped onto the mold 21 and molded by light irradiation or heat. When pressure welding, it is necessary to be careful not to allow air or other bubbles to enter the resin. This is because if air bubbles are taken into the molded body, the light transmitted through the part is scattered. After polymerization, release from the mold 21 yields a relaxation layer 14 that is a flat layer integrated with the transparent substrate 11.

  At this time, since the formed relaxation layer 14 contains a preliminarily prepared polymerization inhibitor in the resin that is the raw material body, the degree of polymerization is not extremely increased by light irradiation or thermal energy, and has a relatively low elasticity. It remains. Subsequently, in forming the molding layer 13, the resin of the relaxation layer 14 is molded using a resin that does not contain a polymerization inhibitor, and an appropriate amount of the resin that forms the molding layer 13 is dropped on the mold 22. . Then, the transparent substrate 11 integrated with the relaxing layer 14 obtained earlier is pressed so that the molding layer 13 and the relaxing layer 14 overlap, and polymerization is performed while molding by light irradiation or heat. Thereafter, by releasing from the mold 22, the relaxing layer 14 that is a flat layer integrated with the transparent substrate 11 and the molding layer 13 that is a layer having a diffraction grating to which the shape of the mold 22 laminated thereon is transferred. A laminated diffractive optical element is obtained.

  Further, as a molding method, for example, the above-mentioned crosslinked vinyl resin is formed into a molding layer 13, and the same crosslinked vinyl resin is blended with a light or thermal polymerization initiator optimized so that the degree of polymerization is smaller than that of the molding layer 13. When used for forming the relaxation layer 14, an appropriate amount of the resin of the relaxation layer 14 showing fluidity is first dropped onto the mold 21. Polymerization is performed while the prescribed transparent substrate 11 is pressed from above the resin of the relaxation layer 14 dropped onto the mold 21 and molded by light irradiation or heat. After polymerization, release from the mold 21 yields a relaxation layer 14 that is a flat layer integrated with the transparent substrate 11.

  At this time, the formed relaxation layer 14 contains a polymerization initiator whose amount is adjusted in advance in the resin, so that the degree of polymerization is not extremely increased by light irradiation or thermal energy, and it remains relatively low in elasticity. is there. Subsequently, in forming the molding layer 13, the molding layer 13 is molded using a resin in which a polymerization initiator is blended so that the degree of polymerization is sufficiently larger than that of the resin of the relaxation layer 14 by light or heat curing. An appropriate amount of resin for forming the molding layer 13 is dropped. Then, the transparent substrate 11 integrated with the relaxing layer 14 obtained earlier is pressed so that the molding layer 13 and the relaxing layer 14 overlap, and polymerization is performed while molding by light irradiation or heat. Thereafter, by releasing from the mold 22, the relaxing layer 14 that is a flat layer integrated with the transparent substrate 11 and the molding layer 13 that is a layer having a diffraction grating to which the shape of the mold 22 laminated thereon is transferred. A laminated diffractive optical element is obtained.

  When molding, if the resin used has crystallinity, etc., and its fluidity is small and it is difficult to drop, the molds 21 and 22 and the resin are appropriately heated with the heater 31, the dispenser 32, etc., and the resin remains in a molten state. It can also be used. At that time, it is desirable to adjust the temperature so that the raw material does not cure by heating. In the method of molding when the resin is dissolved in a solvent, in order to obtain a molded body that well preserves the desired shape, the solvent used is gradually removed by evaporation. Using a fluid as a main component at room temperature without using a solvent or a monomer that can be melted by heating makes it possible to produce a molded product that better preserves the desired shape in a relatively short working time.

  Resin molded bodies obtained by these molding methods can be formed in a desired shape in a single step, and high reproducibility of molding can be achieved.

  The energy curable resin 12 supplied between the molding dies 21 and 22 and the transparent substrate 11 needs to be adjusted and held at a certain viscosity in order to form a layer to be molded uniformly. Although the viscosity range varies depending on the thickness of the layer to be formed, it is generally preferable that the viscosity be in the range of 50 to 5000 mPa · s. By adjusting the viscosity within this range, the discharge amount can be stably adjusted using the dispenser 32. More preferably, it is preferable to adjust to the range of 100 to 1000 mPa · s. When the viscosity is less than 50 mPa · s, it is difficult to adjust a small amount of dripping, and a phenomenon occurs in which the liquid scatters from the dripping nozzle.

  In addition, when the viscosity is 5000 mPa · s or more, the optical material of the present invention has the yarn property, so that there is a possibility that the yarn is pulled from the nozzle and adhered to other than the desired portion. As a method for adjusting the viscosity, it is effective to make the polymer compatible with the monomer of the base resin. By doing so, the viscosity can be optimized without changing the optical characteristics. The amount of the polymer added is desirably 5% by weight or more and 30% by weight or less of the total weight ratio. If it is said range, it can adjust to the viscosity range preferable for shaping | molding.

  By adopting this configuration, the relaxation layer 14 absorbs and relaxes the stress load caused by internal stress and external force applied to the molding layer 13. Further, since the relaxation layer 14 is formed of the same kind of material as that of the molding layer 13, it has substantially the same optical characteristics, and even if it is a laminated type, the loss of optical performance such as diffraction efficiency is small as an optical element.

  Examples of the present invention will be described more specifically below, but the present invention is not limited by them.

  In the Example of this invention, resin of the composition 1-9 which mixed and adjusted each compound in the ratio of Table 1 was used. N-vinylcarbazole (Tokyo Chemical Industry Co., Ltd .: hereinafter referred to as VCz), poly N-vinylcarbazole (Tokyo Chemical Industry Co., Ltd .: hereinafter referred to as PVCz), Irgacure 184 (registered trademark) (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator : Hereinafter referred to as IC-184), divinyl adipate (manufactured by Shin-Etsu Vinyl Acetate Co., Ltd .: hereinafter referred to as ADV) as a crosslinking agent, MegaFac 1405 (manufactured by Dainippon Ink & Chemicals, Inc .: hereinafter referred to as MF-1405) as a release agent, and polymerization prohibition Nonflex F (manufactured by Seiko Chemical Co., Ltd .: NF-F) was appropriately mixed as an agent, and heated and melted at 80 ° C. for 3 hours. After confirming that it was completely melted, a photocurable resin 33 of this example was obtained.

  A mold for producing the molded body is shown in FIG. A flat mold in which copper plating was formed to a thickness of 400 μm on the surface of a cylindrical SUS type and a mold having a diffraction grating with a pitch of 80 μm, a grating height of 10 μm, and an apex angle of 45 ° were prepared. Next, electroless nickel plating was performed on the flat portion of the flat mold and on the pattern portion of the mold having the diffraction grating to obtain lens molds 21 and 22 used in the examples of the present invention. In order to give a temperature to the mold, the mold was manufactured taking into consideration the linear expansion coefficient of the transparent substrate 11, the photocurable resin 33, and the mold.

  The outline of the molding method of the molded product in the embodiment of the present invention will be described with reference to the schematic diagram of FIG. In FIG. 3, a photocurable resin 33 (compositions 1 to 9 in Table 1) is dropped onto a flat mold 21 or a mold 22 having a diffraction grating, and the transparent substrate 11 is pressed and spread from above to form a desired shape. At this point, light is emitted from the light source 34 to cure the photocurable resin 33, and molding is performed by releasing the cured product together with the transparent substrate 11. The molds 21 and 22 can be heated by a heater 31 as necessary. The mold temperature during molding in this example was 80 ° C. In the step of laminating, using the molded body integrated with the transparent substrate 11 obtained previously, the same steps as described above are repeated in place of the material and mold shape to be laminated.

  As the transparent substrate 11 in the example of the present invention, a glass material BK7, a thickness of 3 mm, and Φ40 mm were used.

<Transmittance measurement using a spectrophotometer>
Using a spectrophotometer (U4000, Hitachi, Ltd.), the transmittance and reflectance at a wavelength of 280 to 800 nm were measured. The composition ratio of the photocurable resin 33 used in this measurement is as shown in Table 1. As a sample for measuring transmittance, about 0.15 g of the photocurable resin 33 in Table 1 kept at 80 ° C. was discharged onto the flat mold 21 at 80 ° C. using the dispenser 32. The temperature of the flat mold 21 is controlled within ± 1.0 ° C. by temperature control. A 50 μm spacer 35 is placed on the flat mold 21, the transparent substrate 11 (BK7: manufactured by OHARA) kept at 80 ° C. is placed on the discharge liquid, and the liquid is filled between the flat mold 21 and the transparent substrate 11. . Further, the substrate was irradiated with ultraviolet rays of 40 mW / cm ² with a central wavelength of 365 nm from the direction of the transparent substrate 11 for 1000 seconds (40 J) and cured, and released from the flat mold 21. The obtained molded film was integrated with the transparent substrate 11, and the temperature was naturally cooled to room temperature. Thus, a transmittance measurement sample using the photocurable resin 33 of this example was obtained.

<Measurement of shear modulus by dynamic viscoelasticity device>
Using a dynamic viscoelasticity measuring device (Rheogel E4000, UBM Co., Ltd.), the shear modulus G was measured under the conditions of temperature dependence of −20 to 250 ° C., 5 ° C./min, and a frequency of 10 Hz. The sample was 5 mm × 25 mm and the film thickness was 50 μm. The composition ratio of the photocurable resin 33 used in this measurement is as shown in Table 1. As a sample for performing dynamic viscoelasticity measurement, about 0.15 g of the photocurable resin 33 in Table 1 kept at 80 ° C. was discharged onto the flat mold 21 at 80 ° C. using the dispenser 32. The temperature of the flat mold 21 is controlled within ± 1.0 ° C. by temperature control.

A 50 μm spacer 35 is placed on the flat mold 21, the transparent substrate 11 (BK7: manufactured by OHARA) kept at 80 ° C. is placed on the discharge liquid, and the liquid is filled between the flat mold 21 and the transparent substrate 11. . Further, it was cured by irradiation with ultraviolet rays of 40 mW / cm ² with a central wavelength of 365 nm from the direction of the transparent substrate 11 for 1000 seconds (40 J), and released from the flat mold 21. The obtained molded film is integrated with the transparent substrate 11 and after the temperature is naturally cooled to room temperature, the molded film is peeled off from the transparent substrate 11 without using a cutter or the like, and then the prescribed measurement shape of 5 mm × 25 mm is used. Cut into strips. In this way, a sample for dynamic viscoelasticity measurement using the photocurable resin 33 of this example was obtained.

  Table 1 shows the transmittance at the time of curing (365 nm), confirmation of yellowing, and measurement results of shear modulus (frequency 10 Hz, 25 ° C. ± 1 ° C.) for the molded films obtained when the respective compositions 1 to 9 were cured in the same manner as described above. It is shown in 2.

  The transmittance and shear modulus decreased as the amount added increased over compositions 2 to 5 to which a polymerization inhibitor was added. In composition 5, since the addition amount of the polymerization inhibitor is large, it results in a relatively large yellowing and is not very suitable as an optical element from the aspect of transmittance. Moreover, the transmittance | permeability showed a tendency to fall, and the shear elasticity modulus showed the upward tendency, so that the photoinitiator in composition 1, 6, 7 increased.

  Hereinafter, examples in which the compositions 1 to 9 are actually combined with Experimental Examples 1 to 9 and Comparative Examples 1 to 4 and a laminated diffractive optical element is molded using a mold will be described.

[Experimental Example 1]
0.15 g of composition 1 resin kept at 80 ° C. was discharged onto a mold 22 having a diffraction grating at 80 ° C. using a dispenser 32. The temperature of the mold 22 is controlled within ± 1.0 ° C. by temperature control. A 50 μm spacer 35 was placed on the mold 22 and a transparent substrate 11 (BK7: manufactured by OHARA) kept at 80 ° C. was placed on the discharge liquid, and the liquid was filled between the mold 22 and the transparent substrate 11. Further, the film was irradiated with ultraviolet rays of 40 mW / cm ² with a central wavelength of 365 nm from the direction of the transparent substrate 11 for 1000 seconds (40 J) and cured, and released from the mold 22. The obtained molded body was integrated with the transparent substrate 11, and the temperature was naturally cooled to room temperature. As a result, a diffractive optical element of Experimental Example 1 was obtained which was a molding layer 13 having a diffraction grating using composition 1 resin (transparent substrate 11 + molding layer 13 having a diffraction grating of composition 1 resin).

[Experimental example 2]
0.15 g of the composition 2 resin kept at 80 ° C. was discharged onto the flat mold 21 at 80 ° C. using the dispenser 32. The temperature of the flat mold 21 is controlled within ± 1.0 ° C. by temperature control. A 50 μm spacer 35 is placed on the flat mold 21, the transparent substrate 11 (BK7: manufactured by OHARA) kept at 80 ° C. is placed on the discharge liquid, and the liquid is filled between the flat mold 21 and the transparent substrate 11. . Further, it was cured by irradiation with ultraviolet rays of 40 mW / cm ² with a central wavelength of 365 nm from the direction of the transparent substrate 11 for 1000 seconds (40 J), and released from the flat mold 21. The obtained molded body was integrated with the transparent substrate 11, and the temperature was naturally cooled to room temperature. As a result, a flat relaxation layer 14 using the composition 2 resin was obtained.

Next, 0.15 g of the composition 1 resin kept at 80 ° C. was discharged onto the mold 22 having the diffraction grating at 80 ° C. using the dispenser 32. The temperature of the mold 22 is controlled within ± 1.0 ° C. by temperature control. A relaxing layer 14 (transparent substrate 11 + relaxation of composition 2 resin) formed by using a composition 2 resin integral with the above-mentioned transparent substrate 11 placed on the mold 22 with a spacer 35 of 50 μm and kept at 80 ° C. in advance. The layer 14) was placed so that the relaxation layer 14 side was attached to the discharge liquid on the mold 22, and the liquid was filled between the mold 22 and the (transparent substrate 11 + composition 2 resin relaxation layer 14). Further, the film was irradiated with ultraviolet rays of 40 mW / cm ² with a central wavelength of 365 nm from the direction of the transparent substrate 11 for 1000 seconds (40 J) and cured, and released from the mold 22. The obtained molded body was integrated with the transparent substrate 11, and the temperature was naturally cooled to room temperature.
As a result, a molding layer 13 having a diffraction grating using composition 1 resin integrated with a relaxation layer 14 using composition 2 resin (transparent substrate 11 + relaxation layer 14 of composition 2 resin + molding layer having a diffraction grating of composition 1 resin) The laminated diffractive optical element of Experimental Example 2 as 13) was obtained.

[Experimental Example 3]
In the same process as in Experimental Example 2, composition 3 resin was used as relaxation layer 14 (transparent substrate 11 + relaxation layer 14 of composition 3 resin + molded layer 13 having diffraction grating of composition 1 resin). A diffractive optical element was obtained.

[Experimental Example 4]
In the same process as in Experimental Example 2, a laminate type of Experimental Example 4 is used in which the composition 4 resin is used as the relaxing layer 14 (transparent substrate 11 + releasing layer 14 of composition 4 resin + molding layer 13 having a diffraction grating of composition 1 resin). A diffractive optical element was obtained.

[Experimental Example 5]
In the same process as in Experimental Example 2, the laminated type of Experimental Example 5 is that the composition 5 resin is used as the relaxing layer 14 (transparent substrate 11 + releasing layer 14 of composition 5 resin + molding layer 13 having a diffraction grating of composition 1 resin). A diffractive optical element was obtained.

[Experimental Example 6]
In the same process as in Experimental Example 2, composition 6 resin was used as relaxation layer 14 (transparent substrate 11 + relaxation layer 14 of composition 6 resin + molding layer 13 having diffraction grating of composition 1 resin). A diffractive optical element was obtained.

[Experimental Example 7]
In the same process as in Experimental Example 2, composition 7 resin was used as relaxation layer 14 (transparent substrate 11 + relaxation layer 14 of composition 7 resin + molded layer 13 having diffraction grating of composition 1 resin). A diffractive optical element was obtained.

[Experimental Example 8]
In the same process as in Experimental Example 2, composition 8 resin was used as relaxation layer 14 (transparent substrate 11 + relaxation layer 14 of composition 8 resin + molded layer 13 having diffraction grating of composition 1 resin). A diffractive optical element was obtained.

[Experimental Example 9]
The laminated type of Experimental Example 9 using composition 9 resin as the relaxing layer 14 (transparent substrate 11 + releasing layer 14 of composition 9 resin + molding layer 13 having a diffraction grating of composition 1 resin) as the relaxing layer 14 by the same process as in Experimental Example 2 A diffractive optical element was obtained.

[Comparative Example 1]
The experimental example 2 was followed except that the thickness of the relaxation layer 14 was changed to 100 μm.

[Comparative Example 2]
Except that the thickness of the relaxation layer 14 was 100 μm, the same procedure as in Experimental Example 3 was performed.

[Comparative Example 3]
Except for the thickness of the relaxation layer 14 being 100 μm, the same procedure as in Experimental Example 6 was followed.

[Comparative Example 4]
Experimental Example 9 was followed except that the thickness of the relaxation layer 14 was 100 μm.

  Table 3 shows the cracking state of the optical element obtained as described above. Each optical element obtained by molding is allowed to stand at room temperature (23 to 24 ° C.) for 24 hours, and then put into a high temperature and high humidity environment test (temperature 60 ° C., humidity 90%) for a certain time (0 to 240, 480, 1000 hours). The occurrence of cracks was confirmed.

  When the composition 1 resin was used as the molding layer 13 in Experimental Example 1, cracks occurred on the entire molding layer 13 after standing at room temperature for about half a day after molding before being put into the high temperature and high humidity environment test.

  In Experimental Examples 2 to 5, when the composition 2 to 5 resin is the relaxation layer 14 and the composition 1 resin is the molding layer 13, the durability of the molding layer 13 with respect to the high temperature and high humidity durability test is increased with an increase in the amount of the polymerization inhibitor. Increased. At that time, regarding the crack, the molded layer 13 obtained in Experimental Example 2 was taken out in 240 hours and then cracked on the entire surface. The molded layer 13 obtained in Experimental Example 3 and Experimental Example 4 was cracked after being taken out after 480 and 1000 hours, respectively, and cracked or cracked along the lattice shape. The molding layer 13 obtained in Experimental Example 5 did not crack even after 1000 hours of the high temperature and high humidity environment durability test.

  In Experimental Example 6, the composition 6 resin containing less photopolymerization initiator than the composition 1 resin was used as the relaxation layer 14, and the composition 1 resin was used as the molding layer 13, the experimental example using the composition 3 resin containing the polymerization inhibitor. The results of the high-temperature and high-humidity durability test almost the same as those in No. 3 The molding layer 13 was cracked by causing cracks or cracks in the ring body along the lattice shape.

  In Experimental Example 7, when the composition 7 resin containing more photopolymerization initiator than the composition 1 resin is used as the relaxation layer 14 and the composition 1 resin is used as the molding layer 13, half a day after molding before being put into the high temperature and high humidity environment test. Cracks were generated on the entire surface of the molding layer 13 when left at room temperature.

  In Experimental Example 8, when the photopolymerization initiator is contained less than the composition 1 resin and the composition 8 resin containing the polymerization inhibitor is the relaxation layer 14 and the composition 1 resin is the molding layer 13, the composition does not contain the polymerization inhibitor. The durability strength was higher than that of Experimental Example 6 using 6 resins. Regarding the crack, the molded layer 13 using the composition 1 resin partially cracked due to a crack or a ring-shaped crack along the lattice shape.

  In Experimental Example 9, when the composition 9 resin containing more photopolymerization initiator than the composition 1 resin and the polymerization inhibitor containing the composition 9 resin was used as the relaxation layer 14 and the composition 1 resin was used as the molding layer 13, it was put into a high temperature and high humidity environment test. Cracks were generated on the entire surface of the molding layer 13 by standing at room temperature for about half a day after molding before molding.

  In Comparative Examples 1 and 2, when the thickness of each of the experimental examples 2 and 3 is set as the relaxation layer 14, the comparative examples 1 and 2 each having a double thickness are compared with the experimental examples 2 and 3 High durability test results were shown.

  In Comparative Example 3, when the thickness of the double layer of Experimental Example 6 was used as the relaxation layer 14, compared with Experimental Example 6, Comparative Example 3 having a double thickness showed a higher durability test result.

  In the comparative example 4, when the thickness of the double layer of the experimental example 9 was used as the relaxation layer 14, the durability test result was higher in the comparative example 4 having the double thickness than in the experimental example 9.

  As is clear from the results of Table 3, by providing the relaxation layer 14 containing an appropriate amount of a polymerization inhibitor and a polymerization initiator as a flat layer on the intermediate layer between the transparent substrate 11 and the molding layer 13 based on Experimental Example 1. Further, the stress relaxation of the molding layer 13 molded with the composition 1 is relaxed by the flexible relaxation layer 14, and a laminated diffractive optical element having crack prevention properties can be realized.

It is a figure which shows the structure of the optical element of this invention. The figure which shows the shape of the lens type | mold used for the Example, [a] shows a flat type | mold, [b] shows the type | mold which has a diffraction grating. In the example of this invention, it is a schematic diagram about the shaping | molding method of the molded article, [a] shows a flat type | mold, [b] shows the type | mold which has a diffraction grating.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Transparent substrate 12 Energy curable resin 13 Molding layer 14 Relaxation layer 21 Flat mold | type 22 Type | mold 31 heater which has a diffraction grating,
32 Dispenser 33 Photo-curing resin 34 of the present invention Light source 35 Spacer

Claims (13)

  At least one surface of the transparent substrate has a plurality of relaxation layers having a low degree of polymerization formed by using the same kind of material as the molding layer as an intermediate layer between the molding layer molded from the energy curable resin and the transparent substrate. A laminated optical element characterized by the above.   A laminated optical element, wherein the molding layer and the relaxation layer according to claim 1 are integrated with the transparent substrate.   The polymerization degree of the relaxation layer according to claim 1 or 2 is such that the type and addition amount of the polymerization inhibitor are within the range of 0.0005% to 5% of the total weight ratio, A laminated optical element characterized in that the amount is adjusted to be lower than that of the molding layer by containing it in the range of 0.005 to 10% of the total weight ratio, and the film thickness is 1 μm to 500 μm.   A laminated diffractive optical element, wherein the optical element according to any one of claims 1 to 3 is a diffractive optical element in which diffraction efficiency of a specific order is increased over the entire use wavelength range.   The laminated diffractive optical element according to claim 4 is different from the laminated diffractive optical element according to claim 4 in the same layer configuration, or optical elements having different layer configurations and optical performances. A laminated diffractive optical element, characterized by being configured by combining diffractive surfaces in opposition.   6. A method of molding an optical element, wherein the optical element according to claim 1 is molded using a molding die.   The method for molding an optical element according to claim 6, wherein a molded product is obtained by thermal polymerization or photopolymerization.   8. An optical material comprising, as a main material, a curable resin containing a substance having at least a carbazole skeleton as a material of the optical element according to claim 1.   The optical material according to claim 8, wherein a curable resin containing at least N-vinylcarbazole is used as a main material.   9. The optical material according to claim 8, wherein the main material is a curable resin containing at least poly (N-vinylcarbazole).   9. The optical material according to claim 8, wherein the main material is a resin containing at least divinyl adipate as a crosslinking agent.   The optical material according to claim 8, comprising at least N-vinylcarbazole and poly (N-vinylcarbazole), divinyl adipate, and a photopolymerization initiator.   13. The optical material according to claim 12, wherein the composition of the optical material is in a range of 5 to 30% by weight of poly (N-vinylcarbazole) and 5 to 30% of divinyl adipate: total weight ratio. .