JP2005266780A - Optical element and optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element having an antireflection film on a synthetic resin, the optical element capable of suppressing deterioration in optical characteristics even when it is irradiated with laser light at short wavelengths, and to provide an optical pickup device using the element. <P>SOLUTION: Deterioration in the optical characteristics can be suppressed for a long time by constituting at least the antireflection film of the optical element in such a manner that a low refractive index layer comprises silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or a mixture of these and that a high refractive index layer comprises scandium oxide, niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, a mixture of tantalum oxide and titanium, silicon nitride or a mixture of these, even when the optical element is used for an optical system in an optical pickup device having a laser light source at short wavelengths. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical element and an optical pickup device, and more particularly to an optical element that allows a light beam from a light source having a short wavelength to pass therethrough and an optical pickup device using the optical element.

In recent years, research and development of a high-density optical disk system capable of recording / reproducing information using a blue-violet semiconductor laser having a wavelength of about 400 nm is rapidly progressing. As an example, an optical disc that records and reproduces information with specifications of NA 0.65 and light source wavelength 407 nm is compared with an optical disc having a diameter of 12 cm that is the same size as DVD (NA 0.6, light source wavelength 650 nm, storage capacity 4.7 GB). Thus, it is possible to record information of 20 to 30 GB per side (see Patent Document 1).
JP 2003-303436 A

  By the way, in an optical pickup device, a plastic optical element that is relatively inexpensive and can be easily mass-produced is often used. However, a short wavelength laser beam emitted from a blue-violet semiconductor laser or the like is generally used. It is known to reduce the durability of various resin materials. On the other hand, it is known that a predetermined resin material has durability against laser light having a short wavelength. However, according to the test conducted by the present inventors, when a plastic objective lens is irradiated with a short wavelength laser beam emitted from a blue-violet semiconductor laser for a certain period of time, the optical characteristics of the irradiated optical element are measured. Was found to deteriorate significantly.

  The present invention has been made in view of such problems, and an optical element in which an antireflection film is formed on a synthetic resin, which can suppress deterioration of optical characteristics even when irradiated with laser light having a short wavelength, and the same are used. An object of the present invention is to provide an optical pickup device.

  The optical element according to claim 1 is an optical element based on a resin used in an optical device provided with a light source that emits light having a wavelength λ1 that satisfies 350 nm ≦ λ1 ≦ 450 nm. A resin containing a polymer having a cyclic structure, and an antireflection film is formed on at least one optical surface of the optical element, and the antireflection film is formed when a light beam having the wavelength λ is allowed to pass through. A low refractive index layer having a refractive index of 1, and a high refractive index layer having a second refractive index higher than the first refractive index when a light beam having the wavelength λ is passed through the low refractive index layer. The refractive index layer is formed of silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or a mixture thereof, and the high refractive index layer is formed of scandium oxide. Niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, a mixture of tantalum oxide and titanium, silicon nitride or a mixture thereof It is characterized by.

  As a result of investigating an optical element having deteriorated optical characteristics, the present inventors have found that the surface of the optical element on which the antireflection film is formed has slight dents and wrinkles, which deteriorate the optical characteristics. . Furthermore, as a result of intensive studies, the present inventors have confirmed that an antireflection film generally containing, for example, titanium oxide and a predetermined resin substrate, which are generally used as a high refractive index layer, are irradiated with laser light having a wavelength of around 400 nm. Inferred that the chemical reaction caused the plastic resin to undergo oxidative degradation and shape change.

  Based on this reasoning, the present inventors have selected the material of the antireflection film by determining the compatibility with a predetermined resin base material, and even when irradiated with a short wavelength light beam, It has been found that it is possible to suppress the generation of fine dents and wrinkles on the surface and to provide optical characteristics capable of maintaining optical characteristics over a long period of time. In such an antireflection film, the low refractive index layer is formed of silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or a mixture thereof. The high refractive index layer is scandium oxide, niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, tantalum oxide and titanium mixture, silicon nitride or It is formed by a mixture of these. The “low refractive index layer” means a layer having a (first) refractive index of 1.30 to 1.55 when irradiated with a light beam having a wavelength λ1 = 405 nm. "Means a layer having a (second) refractive index of 1.70 or more when irradiated with a light beam having a wavelength of λ1 = 405 nm. Moreover, the said substance which forms a layer shall refer to the main component of each layer, and may contain several% of foreign substances.

  The optical element according to claim 2 is the invention according to claim 1, wherein the high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, praseodymium titanate, lanthanum titanate, hafnium oxide, zirconium oxide Since it is formed by tantalum, a mixture of tantalum oxide and titanium, silicon nitride, or a mixture thereof, a higher effect of suppressing deterioration of optical characteristics can be expected.

  The optical element according to claim 3 is the invention according to claim 1, wherein the high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, hafnium oxide, zirconium oxide, tantalum oxide, silicon nitride, or these. Since it is characterized by being formed of a mixture, a higher effect of suppressing the deterioration of optical properties can be expected.

  The optical element according to claim 4 is the invention according to any one of claims 1 to 3, wherein the antireflection film is laminated on a resin base material in the order of the high refractive index layer and the low refractive index layer. It is characterized by having a two-layer structure.

  The optical element according to claim 5 is the invention according to any one of claims 1 to 3, wherein the antireflection film is formed on a resin base material with the low refractive index layer, the high refractive index layer, and the low refractive index layer. A three-layer structure in which refractive index layers are stacked in order.

  An optical element according to a sixth aspect is the optical element according to any one of the first to third aspects, wherein the antireflection film is higher than the first refractive index when a light flux having the wavelength λ is passed. Has a middle refractive index layer having a third refractive index lower than the second refractive index, and the middle refractive index layer is made of lanthanum fluoride, neodymium fluoride, cerium fluoride, aluminum fluoride, lanthanum aluminate In addition, since it is formed of lead fluoride, aluminum oxide, or a mixture thereof, it is possible to provide an antireflection film having a low reflectance even with respect to light beams having different wavelengths. The “medium refractive index layer” refers to a layer having a (third) refractive index of 1.55 to 1.70 when irradiated with a light beam having a wavelength λ1 = 405 nm.

  The optical element according to claim 7 is the invention according to any one of claims 1 to 3 and 6, wherein the antireflection film has a layer structure in which four or more layers are laminated on the surface of a resin substrate. Therefore, since the wavelength region of low reflectance can be made wider than in the case of the two- or three-layer configuration, it is possible to provide an antireflection film that keeps the reflectance low even for light beams of different wavelengths. For example, in addition to light having a wavelength λ1 satisfying 350 nm ≦ λ1 ≦ 450 nm, light having a wavelength λ2 satisfying 620 nm ≦ λ2 ≦ 670 nm (light for DVD recording / playback), and wavelength λ3 satisfying 760 nm ≦ λ3 ≦ 800 nm It is possible to provide an antireflection film with a low reflectance for at least one kind of light (light for CD recording / reproducing).

An optical element according to an eighth aspect of the present invention is the optical element according to the seventh aspect, wherein the antireflection film is formed on the surface of a resin base material in a laminated structure including four layers. When the first layer is the layer closest to, and the layer number increases as you move away from the surface of the substrate,
Laminating in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n4 are the refractive index of the material, and d1 to d4 are the thickness of the material,
First layer: 1.7 ≦ n1, 15 nm ≦ d1 ≦ 36 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 25 nm ≦ d2 ≦ 40 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 150 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 90 nm ≦ d4 ≦ 115 nm
It is characterized by that.

The optical element according to claim 9 is characterized in that, in the invention according to claim 7, the antireflection film is formed on the surface of the resin base material in a laminated structure comprising five layers, When the first layer is the layer closest to, and the layer number increases as you move away from the surface of the substrate,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n5 are the refractive index of the material, and d1 to d5 are the thickness of the material. Well,
First layer: 1.2 ≦ n1 ≦ 1.55, 5 nm ≦ d1 ≦ 20 nm
Second layer: 1.7 ≦ n2, 15 nm ≦ d2 ≦ 35 nm
3rd layer: 1.2 ≦ n3 ≦ 1.55, 25 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 50 nm ≦ d4 ≦ 130 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 80 nm ≦ d5 ≦ 110 nm
It is characterized by that.

An optical element according to claim 10 is characterized in that, in the invention according to claim 7, the antireflection film is formed in a laminated structure comprising six layers on the surface of the resin base material. When the first layer is the layer closest to, and the layer number increases as you move away from the surface of the substrate,
Laminate in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, where n1 to n6 are the refractive indices of the materials, d1 d6 is the thickness of the material,
First layer: 1.7 ≦ n1, 8 nm ≦ d1 ≦ 15 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 35 nm ≦ d2 ≦ 55 nm
Third layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 60 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 10 nm ≦ d4 ≦ 17 nm
5th layer: 1.7 ≦ n5, 45 nm ≦ d5 ≦ 90 nm
6th layer: 1.2 ≦ n6 ≦ 1.55, 70 nm ≦ d6 ≦ 110 nm
It is characterized by that.

An optical element according to an eleventh aspect is characterized in that, in the invention according to the seventh aspect, the antireflection film is formed on a resin base material surface in a laminated structure comprising seven layers. When the first layer is the layer closest to, and the layer number increases as you move away from the surface of the substrate,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material. Refractive index, d1-d7 is the thickness of the material,
First layer: 1.2 ≦ n1 ≦ 1.55, 80 nm ≦ d1 ≦ 160 nm
Second layer: 1.7 ≦ n2, 10 nm ≦ d2 ≦ 25 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 33 nm ≦ d3 ≦ 45 nm
Fourth layer: 1.7 ≦ n4, 40 nm ≦ d4 ≦ 85 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 10 nm ≦ d5 ≦ 20 nm
6th layer: 1.7 ≦ n6, 6 nm ≦ d6 ≦ 70 nm
Seventh layer: 1.2 ≦ n7 ≦ 1.55, 60 nm ≦ d7 ≦ 110 nm.

  12. The optical element according to claim 8, wherein the antireflection film has a layer configuration in which four to seven layers are laminated on a resin base material surface, and a high refractive index layer and a low refractive index layer are alternately arranged. Since it is a layer structure in which the refractive index and the thickness of the layers are limited, the reflectance is not only for the wavelength λ1 but also for at least one type of light having the wavelength λ2 and the wavelength λ3. It is possible to provide a low-reflection antireflection film.

  The optical element according to claim 12 is the invention according to any one of claims 8 to 11, wherein the low refractive index layer is made of silicon oxide or a mixture of silicon oxide and aluminum oxide, or a mixture thereof. The high refractive index layer is formed of hafnium oxide, lanthanum aluminate, zirconium oxide, tantalum oxide, silicon nitride, or a mixture thereof.

  According to the present invention, the material of the low-refractive index layer and the material of the high-refractive index layer of the antireflective film is limited, so that the surface deformation or peeling of the antireflective film with respect to laser light with a wavelength of 405 to 415 nm is prevented. It is possible to provide an antireflection film that has a small amount of light absorption with respect to light of 405 nm, and that has little surface deformation and peeling even when left in a high temperature and high humidity environment.

  An optical element according to a thirteenth aspect is the optical element according to any one of the seventh to twelfth aspects, wherein the optical device has wavelengths λ2 and 760 nm ≦ λ3 satisfying 620 nm ≦ λ2 ≦ 670 nm in addition to the light source having the wavelength λ1. A light source that emits light of at least one wavelength of wavelength λ3 satisfying ≦ 800 nm is provided, and the light of the plurality of light sources is transmitted through the optical element. For example, blue light is used. Provided is an optical element that can be used not only for a high-density optical disc but also for at least one kind of light for DVD or CD.

  The optical element according to claim 14 is the optical device according to any one of claims 1 to 13, wherein the polymer having the alicyclic structure has a weight average molecular weight (Mw) of 1,000 to 1,000,000. It is represented by the repeating unit (a) having an alicyclic structure represented by the following general formula (1), the following general formula (2) and / or the following general formula (3) in all the polymer repeating units. A repeating unit (b) having a chain structure having a total content of 90% by weight or more, and further a content of the repeating unit (b) of 1% by weight or more and less than 10% by weight. Features. Particularly, in the polymer, the chain of the repeating unit (a) has a relational expression A ≦ 0.3 × B (where A = (weight average molecular weight of the chain of repeating unit having an alicyclic structure), B = ( What satisfies the weight average molecular weight (Mw) of the alicyclic hydrocarbon copolymer) × (number of repeating units having an alicyclic structure / number of all repeating units constituting the alicyclic hydrocarbon copolymer)) It is preferable that

  R1 to R13 in formula (1), formula (2), and formula (3) are each independently a hydrogen atom, chain hydrocarbon group, halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group. Chain carbonization substituted with groups, amide groups, imide groups, silyl groups, and polar groups (halogen atoms, alkoxy groups, hydroxy groups, ether groups, ester groups, cyano groups, amide groups, imide groups, or silyl groups) Represents a hydrogen group or the like. Among these, a hydrogen atom or a chain hydrocarbon group having 1 to 6 carbon atoms is preferable because of excellent heat resistance and low water absorption. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the chain hydrocarbon group substituted with a polar group include halogenated alkyl groups having 1 to 20, preferably 1 to 10, more preferably 1 to 6 carbon atoms. As the chain hydrocarbon group, for example, an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms; 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, more preferably 2 to 2 carbon atoms. 6 alkenyl groups.

  X in the general formula (1) represents an alicyclic hydrocarbon group, and the number of carbon atoms constituting the group is usually 4 to 20, preferably 4 to 10, more preferably 5 to 7. is there. Birefringence can be reduced by setting the number of carbon atoms constituting the alicyclic structure within this range. The alicyclic structure is not limited to a monocyclic structure, and may be a polycyclic structure such as a norbornane ring or a dicyclohexane ring.

  The alicyclic hydrocarbon group may have a carbon-carbon unsaturated bond, but its content is 10% or less, preferably 5% or less, more preferably 3% or less of the total carbon-carbon bonds. is there. By setting the carbon-carbon unsaturated bond of the alicyclic hydrocarbon group within this range, transparency and heat resistance are improved. The carbon constituting the alicyclic hydrocarbon group includes a hydrogen atom, a hydrocarbon group, a halogen atom, an alkoxy group, a hydroxy group, an ether group, an ester group, a cyano group, an amide group, an imide group, a silyl group, and A chain hydrocarbon group or the like substituted with a polar group (halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group, amide group, imide group, or silyl group) may be bonded. A hydrogen atom or a chain hydrocarbon group having 1 to 6 carbon atoms is preferred in terms of heat resistance and low water absorption.

  In the general formula (3),... Represents a carbon-carbon saturated or carbon-carbon unsaturated bond in the main chain. If transparency and heat resistance are strongly required, the inclusion of an unsaturated bond. The rate is usually 10% or less, preferably 5% or less, and more preferably 3% or less, of all the carbon-carbon bonds constituting the main chain.

  Among the repeating units represented by the general formula (1), the repeating unit represented by the following general formula (4) is excellent in terms of heat resistance and low water absorption.

  Among the repeating units represented by the general formula (2), the repeating unit represented by the following general formula (5) is excellent in terms of heat resistance and low water absorption.

  Among the repeating units represented by the general formula (3), the repeating unit represented by the following general formula (6) is excellent in terms of heat resistance and low water absorption.

  In general formula (4), general formula (5), and general formula (6), Ra, Rb, Rc, Rd, Re, Rf, Rg, Rh, Ri, Rj, Rk, Rl, Rm, and Rn are respectively A hydrogen atom or a lower chain hydrocarbon group is independently shown, and a hydrogen atom or a lower alkyl group having 1 to 6 carbon atoms is excellent in terms of heat resistance and low water absorption.

  Among the repeating units of the chain structure represented by the general formula (2) and the general formula (3), the repeating unit of the chain structure represented by the general formula (3) is more preferable in the hydrocarbon-based weight obtained. Excellent combined strength characteristics.

  In the present invention, the hydrocarbon copolymer is represented by the repeating unit (a) having an alicyclic structure represented by the general formula (1), the general formula (2) and / or the general formula (3). The total content of the chain-structured repeating unit (b) is usually 90% or more, preferably 95% or more, more preferably 97% or more, on a weight basis. By setting the total content within the above range, low birefringence, heat resistance, low water absorption, and mechanical strength are highly balanced.

  The content of the repeating unit (b) having a chain structure in the polymer having an alicyclic structure is appropriately selected according to the purpose of use, but is usually 1% or more and less than 10%, preferably 1% or more on a weight basis. The range is 8% or less, more preferably 2% or more and 6% or less. When the content of the repeating unit (b) is in the above range, low birefringence, heat resistance, and low water absorption are highly balanced.

  Further, the chain length of the repeating unit (a) is sufficiently shorter than the molecular chain length of the polymer having an alicyclic structure, specifically, A = (weight of the repeating unit chain having an alicyclic structure). Average molecular weight), B = (Weight average molecular weight of polymer having alicyclic structure (Mw) × (number of repeating units having alicyclic structure / number of all repeating units constituting the polymer having alicyclic structure)) ), A is 30% or less of B, preferably 20% or less, more preferably 15% or less, and particularly preferably 10% or less. When A is outside this range, the low birefringence is poor.

  Furthermore, it is preferable that the chain length of the repeating unit (a) has a specific distribution. Specifically, when A = (weight average molecular weight of repeating unit chain having an alicyclic structure) and C = (number average molecular weight of repeating unit chain having an alicyclic structure), A / C is preferable. Is 1.3 or more, more preferably 1.3 to 8, and most preferably 1.7 to 6. When A / C is excessively small, the degree of block increases, and when it is excessively large, the degree of randomness increases, and in any case, low birefringence is inferior.

  The molecular weight of the polymer having the alicyclic structure (also referred to as alicyclic hydrocarbon copolymer) of the present invention is polystyrene (or polyisoprene) measured by gel permeation chromatography (hereinafter, GPC). In terms of weight average molecular weight (Mw), 1,000 to 1,000,000, preferably 5,000 to 500,000, more preferably 10,000 to 300,000, most preferably 50,000 to 250,000. Range. If the weight average molecular weight (Mw) of the polymer having an alicyclic structure is excessively small, the strength characteristics of the molded product are inferior. Conversely, if the polymer is excessively large, the birefringence of the molded product increases.

  The molecular weight distribution of such a copolymer can be appropriately selected according to the purpose of use, but the ratio (Mw) of polystyrene (or polyisoprene) -converted weight average molecular weight (Mw) and number average molecular weight (Mn) measured by GPC. / Mn), usually 2.5 or less, preferably 2.3 or less, more preferably 2 or less. When Mw / Mn is in this range, mechanical strength and heat resistance are highly balanced.

  The glass transition temperature (Tg) of the copolymer may be appropriately selected according to the purpose of use, but is usually 50 ° C to 250 ° C, preferably 70 ° C to 200 ° C, more preferably 90 ° C to 180 ° C. .

(Method for producing polymer having alicyclic structure)
The method for producing a polymer having an alicyclic structure according to the present invention comprises (1) copolymerizing an aromatic vinyl compound and another monomer copolymerizable, and a carbon-carbon unsaturated bond of the main chain and aromatic ring. And (2) a method of copolymerizing an alicyclic vinyl compound with another monomer copolymerizable and hydrogenating as necessary.

  When the polymer having an alicyclic structure of the present invention is produced by the above method, other monomer (b) copolymerizable with the aromatic vinyl compound and / or the alicyclic vinyl compound (a ′). The repeating unit derived from the compound (a ′) in the copolymer is a weight average of repeating unit chains derived from D = (aromatic vinyl compound and / or alicyclic vinyl compound). Molecular weight), E = (Weight average molecular weight of hydrocarbon copolymer (Mw) × (Number of repeating units derived from aromatic vinyl compound and / or alicyclic vinyl compound / Hydrocarbon copolymer) The total number of repeating units)), D is 30% or less of E, preferably 20% or less, more preferably 15% or less, and most preferably 10% or less. Chains, aromatic rings and cycloalkenes It can be efficiently obtained by a method for hydrogenating carbon-carbon unsaturated bond - unsaturated carbon ring and the like. When D is out of the above range, the low birefringence of the resulting polymer having an alicyclic structure is inferior.

  In the present invention, the method (1) is preferable because a polymer having an alicyclic structure can be obtained more efficiently.

  The copolymer before hydrogenation further has a D / F when F = (number average molecular weight of a chain of repeating units derived from an aromatic vinyl compound and / or an alicyclic vinyl compound). A certain range is preferable. Specifically, D / F is preferably 1.3 or more, more preferably 1.3 or more and 8 or less, and most preferably 1.7 or more and 6 or less. When D / F is outside this range, the low birefringence of the resulting polymer having an alicyclic structure is inferior.

  The weight average molecular weight and number average molecular weight of the chain of repeating units derived from the above compound (a ′) are, for example, unsaturated two in the main chain of the aromatic vinyl copolymer described in the document Macromolecules 1983, 16, 1925-1928. It can be confirmed by, for example, a method of measuring the molecular weight of the aromatic vinyl chain taken out by reductive decomposition after adding a heavy bond with ozone.

  The molecular weight of the copolymer before hydrogenation is 1,000 to 1,000,000, preferably 5,000 to 500,000 in terms of polystyrene (or polyisoprene) equivalent weight average molecular weight (Mw) measured by GPC. More preferably, it is in the range of 10,000 to 300,000. When the weight average molecular weight (Mw) of the copolymer is excessively small, the strength characteristics of the molded product of the polymer having an alicyclic structure obtained therefrom are inferior. On the contrary, when the copolymer is excessively large, the hydrogenation reactivity is inferior.

  Specific examples of the aromatic vinyl compound used in the method (1) include, for example, styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-isopropylstyrene, α-t-butylstyrene. 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, monochlorostyrene , Dichlorostyrene, monofluorostyrene, 4-phenylstyrene and the like, and styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene and the like are preferable.

  Specific examples of the alicyclic vinyl compound used in the method (2) include, for example, cyclobutylethylene, cyclopentylethylene, cyclohexylethylene, cycloheptylethylene, cyclooctylethylene, norbornylethylene, dicyclohexylethylene, α -Methylcyclohexylethylene, α-t-butylcyclohexylethylene, cyclopentenylethylene, cyclohexenylethylene, cycloheptenylethylene, cyclooctenylethylene, cyclodecenylethylene, norbornenylethylene, α-methylcyclohexenylethylene, and α -T-butylcyclohexenylethylene etc. are mentioned, Among these, cyclohexylethylene and (alpha) -methylcyclohexylethylene are preferable.

  These aromatic vinyl compounds and alicyclic vinyl compounds can be used alone or in combination of two or more.

  Other monomers that can be copolymerized are not particularly limited, but chain vinyl compounds and chain conjugated diene compounds are used. When chain conjugated dienes are used, the operability in the production process is excellent. The obtained polymer having an alicyclic structure is excellent in strength properties.

  Specific examples of the chain vinyl compound include chain olefin monomers such as ethylene, propylene, 1-butene, 1-pentene and 4-methyl-1-pentene; 1-cyanoethylene (acrylonitrile), 1-cyano- Nitrile monomers such as 1-methylethylene (methacrylonitrile) and 1-cyano-1-chloroethylene (α-chloroacrylonitrile); 1- (methoxycarbonyl) -1-methylethylene (methacrylic acid methyl ester), 1- (Ethoxycarbonyl) -1-methylethylene (methacrylic acid ethyl ester), 1- (propoxycarbonyl) -1-methylethylene (methacrylic acid propyl ester), 1- (butoxycarbonyl) -1-methylethylene (methacrylic) Acid butyl ester), 1-methoxycarboni (Meth) acrylic acid such as ethylene (acrylic acid methyl ester), 1-ethoxycarbonylethylene (acrylic acid ethyl ester), 1-propoxycarbonylethylene (acrylic acid propyl ester), 1-butoxycarbonylethylene (acrylic acid butyl ester) Ester monomers, 1-carboxyethylene (acrylic acid), 1-carboxy-1-methylethylene (methacrylic acid), unsaturated fatty acid monomers such as maleic anhydride, and the like are mentioned, among which chain olefin monomers are preferable, Most preferred are ethylene, propylene and 1-butene.

  Examples of the chain conjugated diene include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. Of these chain vinyl compounds and chain conjugated dienes, chain conjugated dienes are preferable, and butadiene and isoprene are particularly preferable. These chain vinyl compounds and chain conjugated dienes can be used alone or in combination of two or more.

  These chain vinyl compounds can be used alone or in combination of two or more.

  The method for polymerizing the compound (a ′) is not particularly limited, but after the polymerization is started using a batch polymerization method (batch method), a monomer sequential addition method (a part of the total amount of monomers used), And a method of proceeding polymerization by successively adding monomers). In particular, when the monomer sequential addition method is used, a hydrocarbon copolymer having a preferable chain structure can be obtained. The copolymer before hydrogenation has a more random chain structure, so that the above-mentioned D value is smaller and / or the D / F shows a larger value. The degree of randomness of the copolymer is determined by the speed ratio between the polymerization rate of the aromatic vinyl compound and the polymerization rate of other copolymerizable monomers, and the smaller this speed ratio, the more It has a random chain structure.

  According to the monomer sequential addition method, since the uniformly mixed monomer is sequentially added into the polymerization system, unlike the batch method, the polymerization selectivity of the monomer is further lowered during the growth process by polymer polymerization. The resulting copolymer has a more random chain structure. In addition, since the accumulation of polymerization reaction heat in the polymerization system is small, the polymerization temperature can be kept low and stable.

  In the case of the monomer sequential addition method, first, the total amount of monomers used is usually 0.01 wt% to 60 wt%, preferably 0.02 wt% to 20 wt%, more preferably 0.05 wt% to 10 wt%. Polymerization is started by adding an initiator in the state in which the monomer is present in the polymerization reactor as an initial monomer. When the initial monomer amount is in such a range, the reaction heat generated in the initial reaction after the initiation of polymerization can be easily removed, and the resulting copolymer can have a more random chain structure.

  When the reaction is continued until the polymerization conversion of the initial monomer is 70% or more, preferably 80% or more, more preferably 90% or more, the chain structure of the resulting copolymer becomes more random. Thereafter, the remainder of the monomer is continuously added, and the rate of addition is determined in consideration of the consumption rate of the monomer in the polymerization system.

  Usually, when the time required for the polymerization rate of the initial monomer to reach 90% is T, and the ratio (%) of the initial monomer to the total used monomer is I, the relational expression [(100−I) × T / I ] Is determined so that the addition of the remaining monomer is completed within a range of 0.5 to 3 times, preferably 0.8 to 2 times, more preferably 1 to 1.5 times the time given by Specifically, the initial monomer amount and the rate of addition of the remaining monomer are determined so that it is usually in the range of 0.1 to 30 hours, preferably 0.5 to 5 hours, more preferably 1 to 3 hours. Further, the total monomer polymerization conversion immediately after completion of the monomer addition is usually 80% or more, preferably 85% or more, and more preferably 90% or more. When the total monomer polymerization conversion rate immediately after the completion of monomer addition is within the above range, the chain structure of the resulting copolymer becomes more random.

  The polymerization reaction is not particularly limited, such as radical polymerization, anionic polymerization, and cationic polymerization. However, the polymerization operation, the ease of the hydrogenation reaction in the post-process, and the mechanical properties of the finally obtained hydrocarbon copolymer are not limited. In view of strength, the anionic polymerization method is preferable.

  In the case of radical polymerization, methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used in the presence of an initiator, usually at 0 ° C to 200 ° C, preferably 20 ° C to 150 ° C. In particular, bulk polymerization and suspension polymerization are desirable when it is necessary to prevent impurities from being mixed into the resin. As radical initiators, benzoyl peroxide, lauroyl peroxide, organic peroxides such as t-butyl-peroxy-2-ethylhexanoate, azoisobutyronitrile, 4,4-azobis-4-cyanopentanoic acid An azo compound such as azodibenzoyl, a water-soluble catalyst typified by potassium persulfate and ammonium persulfate, a redox initiator, and the like can be used.

  In the case of anionic polymerization, bulk polymerization, solution polymerization, slurry polymerization, etc. in the temperature range of usually 0 ° C. to 200 ° C., preferably 20 ° C. to 100 ° C., particularly preferably 20 ° C. to 80 ° C. in the presence of an initiator. However, solution polymerization is preferable in view of removal of reaction heat. In this case, an inert solvent capable of dissolving the polymer and its hydride is used. Examples of the inert solvent used in the solution reaction include aliphatic hydrocarbons such as n-butane, n-pentane, iso-pentane, n-hexane, n-heptane, and iso-octane; cyclopentane, cyclohexane, methylcyclopentane, Examples include alicyclic hydrocarbons such as methylcyclohexane and decalin; aromatic hydrocarbons such as benzene and toluene. Among them, when aliphatic hydrocarbons and alicyclic hydrocarbons are used, hydrogenation reaction is also performed. It can be used as it is as an inert solvent. These solvents can be used alone or in combination of two or more, and are usually used at a ratio of 200 to 10,000 parts by weight with respect to 100 parts by weight of all the monomers used.

  Examples of the initiator for the anionic polymerization include monoorganolithium such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, and phenyllithium, dilithiomethane, 1,4-diobane, and 1,4-dilithio. A polyfunctional organolithium compound such as 2-ethylcyclohexane can be used.

  In the polymerization reaction, a polymerization accelerator, a randomizer (an additive having a function of preventing a long chain of one component) from being used, and the like can be used. In the case of anionic polymerization, for example, a Lewis base compound can be used as a randomizer. Specific examples of the Lewis base compound include ether compounds such as dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol diethyl ether, ethylene glycol methyl phenyl ether; tetramethylethylenediamine, trimethylamine, triethylamine, pyridine Tertiary amine compounds such as potassium; t-amyl oxide, alkali metal alkoxide compounds such as potassium t-butyl oxide; and phosphine compounds such as triphenylphosphine. These Lewis base compounds can be used alone or in combination of two or more.

  The polymer obtained by the above radical polymerization or anion polymerization can be recovered by a known method such as a steam stripping method, a direct solvent removal method, or an alcohol coagulation method. In addition, when an inert solvent is used in the hydrogenation reaction during the polymerization, the polymer is not recovered from the polymerization solution and can be used as it is in the hydrogenation step.

Hydrogenation method of unsaturated bond When conducting hydrogenation reaction such as carbon-carbon double bond of unsaturated ring such as aromatic ring or cycloalkene ring of copolymer before hydrogenation or unsaturated bond of main chain, There is no particular limitation on the reaction method and reaction form, and it may be carried out according to a known method. However, a hydrogenation method that can increase the hydrogenation rate and has little polymer chain scission reaction that occurs simultaneously with the hydrogenation reaction is preferable. And a method of using a catalyst containing at least one metal selected from nickel, cobalt, iron, titanium, rhodium, palladium, platinum, ruthenium and rhenium in an organic solvent. As the hydrogenation catalyst, either a heterogeneous catalyst or a homogeneous catalyst can be used.

  The heterogeneous catalyst can be used in the form of a metal or a metal compound or supported on a suitable carrier. Examples of the carrier include activated carbon, silica, alumina, calcium carbide, titania, magnesia, zirconia, diatomaceous earth, silicon carbide and the like. The supported amount of the catalyst is usually 0.01 to 80% by weight, preferably 0. The range is from 05 to 60% by weight. The homogeneous catalyst is a catalyst in which a nickel, cobalt, titanium or iron compound and an organometallic compound (for example, an organoaluminum compound or an organolithium compound) are combined, or an organometallic complex catalyst such as rhodium, palladium, platinum, ruthenium or rhenium. Can be used. Examples of the nickel, cobalt, titanium, or iron compound include acetylacetone salts, naphthene salts, cyclopentadienyl compounds, cyclopentadienyl dichloro compounds, and the like of various metals. As the organic aluminum compound, alkylaluminum such as triethylaluminum and triisobutylaluminum, aluminum halide such as diethylaluminum chloride and ethylaluminum dichloride, alkylaluminum hydride such as diisobutylaluminum hydride and the like are preferably used.

  As an example of the organometallic complex catalyst, a metal complex such as a γ-dichloro-π-benzene complex, a dichloro-tris (triphenylphosphine) complex, a hydrido-chloro-triphenylphosphine) complex of each of the above metals is used. These hydrogenation catalysts can be used alone or in combination of two or more, and the amount used is usually 0.01 to 100 parts, preferably on the basis of weight with respect to the polymer. 0.05 to 50 parts, more preferably 0.1 to 30 parts.

  The hydrogenation reaction is usually 10 ° C. to 250 ° C., but preferably 50 ° C. to 200 ° C. because the hydrogenation rate can be increased and the polymer chain scission reaction occurring simultaneously with the hydrogenation reaction can be reduced. More preferably, it is 80 degreeC-180 degreeC. The hydrogen pressure is usually 0.1 MPa to 30 MPa, but in addition to the above reasons, from the viewpoint of operability, it is preferably 1 MPa to 20 MPa, more preferably 2 MPa to 10 MPa.

  The hydrogenation rate of the hydride obtained in this manner is determined by 1H-NMR, as determined by carbon-carbon unsaturated bond of the main chain, carbon-carbon double bond of aromatic ring, carbon-carbon of unsaturated ring. All of the double bonds are usually 90% or more, preferably 95% or more, more preferably 97% or more. When the hydrogenation rate is low, the low birefringence, thermal stability, etc. of the resulting copolymer are lowered.

  The method for recovering the hydride after completion of the hydrogenation reaction is not particularly limited. Usually, after removing the hydrogenation catalyst residue by a method such as filtration or centrifugation, the solvent is removed directly from the hydride solution by drying, the hydride solution is poured into a poor solvent for the hydride, and the hydride A method of coagulating can be used.

(Resin composition)
In this invention, the resin composition which contains antioxidant in the polymer which has the said alicyclic structure is provided.

  Examples of the antioxidant include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among them, phenolic antioxidants, particularly alkyl-substituted phenolic antioxidants are preferable. By blending these antioxidants, it is possible to prevent coloring and strength reduction of the molded product due to oxidative degradation during molding without lowering transparency and low water absorption.

  A conventionally well-known thing can be used as a phenolic antioxidant, for example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2 , 4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate and the like, and JP-A Nos. 63-179953 and 1-168643. Acrylate compounds described in Japanese Patent Publication No. 1; octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) ), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5 Di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenylpropionate) methane [ie, pentaerythrmethyl-tetrakis] (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate), etc. Alkyl substituted phenol compounds; 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3 5-triazine, 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyanilino) -1,3,5-triazine What triazine group-containing phenol compound; and the like.

  The phosphorus antioxidant is not particularly limited as long as it is usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) Phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10 Monophosphite compounds such as dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite ), 4,4′isopropylidene-bis (phenyl-di-alkyl (C12-C15) phosphite) What diphosphite compounds and the like. Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

  Examples of the sulfur-based antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3-thiodipro Pionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate, 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane It is done.

  These antioxidants can be used alone or in combination of two or more, and the blending amount thereof is appropriately selected within a range not impairing the object of the present invention, but has an alicyclic structure. The amount is usually 0.001 to 5 parts by weight, preferably 0.01 to 1 part by weight based on 100 parts by weight of the polymer.

  In the present invention, at least one compounding agent selected from the group consisting of a polymer having the alicyclic structure, (1) a soft polymer, (2) an alcoholic compound, and (3) an organic or inorganic filler. A resin composition is provided. By blending these compounding agents, it is possible to prevent white turbidity in a high temperature and high humidity environment for a long time without degrading various properties such as transparency, low water absorption, and mechanical strength.

  Among these, (1) a soft polymer and (2) an alcoholic compound are excellent in the effect of preventing white turbidity in a high-temperature and high-humidity environment and the transparency of the resulting resin composition.

(1) Soft polymer The soft polymer used for this invention is a polymer which usually has Tg of 30 degrees C or less, and when multiple Tg exists, at least lowest Tg should just be 30 degrees C or less.

  Specific examples of these soft polymers include, for example, liquid polyethylene, polypropylene, poly-1-butene, ethylene / α-olefin copolymers, propylene / α-olefin copolymers, and ethylene / propylene / diene copolymers. (EPDM), olefin-based soft polymers such as ethylene / propylene / styrene copolymers; isobutylene-based soft polymers such as polyisobutylene, isobutylene / isoprene rubber, and isobutylene / styrene copolymers; polybutadiene, polyisoprene, butadiene / styrene Random copolymer, isoprene / styrene random copolymer, acrylonitrile / butadiene copolymer, acrylonitrile / butadiene / styrene copolymer, butadiene / styrene / block copolymer, styrene / butadiene / styrene block Copolymers, diene-based soft polymers such as isoprene / styrene / block copolymers, styrene / isoprene / styrene / block copolymers; silicon-containing soft polymers such as dimethylpolysiloxane, diphenylpolysiloxane, and dihydroxypolysiloxane Soft polymers composed of α, β-unsaturated acids such as polybutyl acrylate, polybutyl methacrylate, polyhydroxyethyl methacrylate, polyacrylamide, polyacrylonitrile, butyl acrylate / styrene copolymer; polyvinyl alcohol, polyvinyl acetate, poly Soft polymers comprising unsaturated alcohols such as vinyl stearate and vinyl acetate / styrene copolymers and amines or acyl derivatives or acetals thereof; polyethylene oxide, polypropylene oxide, Epoxy soft polymers such as chlorohydrin rubber; Fluorine soft polymers such as vinylidene fluoride rubber and tetrafluoroethylene-propylene rubber; natural rubber, polypeptide, protein, polyester thermoplastic elastomer, Other soft polymers such as vinyl chloride thermoplastic elastomers and polyamide thermoplastic elastomers may be mentioned. These soft polymers may have a cross-linked structure or may have a functional group introduced by a modification reaction.

  Of the above-mentioned soft polymers, diene-based soft polymers are preferable. In particular, hydrides obtained by hydrogenating carbon-carbon unsaturated bonds of the soft polymers are excellent in terms of rubber elasticity, mechanical strength, flexibility, and dispersibility.

(2) Alcoholic Compound The alcoholic compound is a compound having at least one non-phenolic hydroxyl group in the molecule, and preferably has at least one hydroxyl group and at least one ether bond or ester bond. Specific examples of such compounds include, for example, dihydric or higher polyhydric alcohols, more preferably trihydric or higher polyhydric alcohols, and even more preferably one of the hydroxyl groups of a polyhydric alcohol having 3 to 8 hydroxyl groups is an ether. Examples thereof include alcoholic ether compounds and alcoholic ester compounds that have been converted into or esterified.

  Examples of the dihydric or higher polyhydric alcohol include polyethylene glycol, glycerol, trimethylolpropane, pentaerythritol, diglycerol, triglycerol, dipentaerythritol, 1,6,7-trihydroxy-2,2-di (hydroxy). Methyl) -4-oxoheptane, sorbitol, 2-methyl-1,6,7-trihydroxy-2-hydroxymethyl-4-oxoheptane, 1,5,6-trihydroxy-3-oxohexanepentaerythritol, tris (2-Hydroxyethyl) isocyanurate and the like can be mentioned, and in particular, a trihydric or higher polyhydric alcohol, more preferably a polyhydric alcohol having 3 to 8 hydroxyl groups. In the case of obtaining an alcoholic ester compound, glycerol, diglycerol, triglycerol or the like capable of synthesizing an alcoholic ester compound containing α, β-diol is preferable.

  Examples of such alcoholic compounds include glycerol monostearate, glycerol monolaurate, glycerol monobehenate, diglycerol monostearate, glycerol distearate, glycerol dilaurate, pentaerythritol monostearate, pentaerythritol monolaurate. , Pentaerythritol monobeherate, pentaerythritol distearate, pentaerythritol dilaurate, pentaerythritol tristearate, dipentaerythritol distearate, and the like; 3- (octyloxy) -1,2-propane Diol, 3- (decyloxy) -1,2-propanediol, 3- (lauryloxy) -1,2-propanediol, 3- (4-nonylphenyl) Xy) -1,2-propanediol, 1,6-dihydrooxy-2,2-di (hydroxymethyl) -7- (4-nonylphenyloxy) -4-oxoheptane, p-nonylphenyl ether and formaldehyde Alcoholic ether compounds obtained by reaction of condensates with glycidol, p-octylphenyl ether and formaldehyde condensates and alcoholic ether compounds obtained by reaction of glycidol, p-octylphenyl ether and dicyclopentadiene condensates and glycidol And alcoholic ether compounds obtained by the above reaction. These polyhydric alcohol compounds are used alone or in combination of two or more. Although the molecular weight of these polyhydric alcohol compounds is not particularly limited, those having a molecular weight of usually 500 to 2000, preferably 800 to 1500, have little decrease in transparency.

(3) Organic or inorganic filler As the organic filler, ordinary organic polymer particles or crosslinked organic polymer particles can be used, for example, polyolefins such as polyethylene and polypropylene; halogen-containing materials such as polyvinyl chloride and polyvinylidene chloride. Polymers derived from α, β-unsaturated acids such as polyarylate and polymethacrylate; Polymers derived from unsaturated alcohols such as polyvinyl alcohol and polyvinyl acetate; Polyethylene oxide or bisglycidyl ether Polymers derived from: Aromatic condensation polymers such as polyphenylene oxide, polycarbonate, and polysulfone; Polyurethanes; Polyamides; Polyesters; Aldehyde-phenolic resins; Natural polymer compounds particles or cross-linked particles Can raise a child.

  Examples of the inorganic filler include group 1 element compounds such as lithium fluoride and borax (sodium borate hydrate); group 2 element compounds such as magnesium carbonate, magnesium phosphate, calcium carbonate, strontium titanate, and barium carbonate; titanium dioxide ( Titania), Group 4 element compounds such as titanium monoxide; Group 6 element compounds of molybdenum dioxide and molybdenum trioxide; Group 7 element compounds such as manganese chloride and manganese acetate; Group 8-10 element compounds such as cobalt chloride and cobalt acetate Group 11 element compounds such as cuprous iodide; Group 12 element compounds such as zinc oxide and zinc acetate; Group 13 such as aluminum oxide (alumina), aluminum fluoride, aluminosilicate (alumina silicate, kaolin, kaolinite) Elemental compounds: silicon oxide (silica, silica gel), graphite, Examples include group 14 element compounds such as carbon, graphite, and glass; particles of natural minerals such as carnal stone, kainite, mica (mica and quinumo), and villose ore.

  The compounding amount of the above compounds (1) to (3) is determined by the combination of the polymer having an alicyclic structure and the compound to be compounded. In general, if the compounding amount is too large, the glass transition temperature and the transparency of the composition are transparent. The properties are greatly reduced, making it unsuitable for use as an optical material. On the other hand, if the blending amount is too small, the molded product may become clouded under high temperature and high humidity. The blending amount is usually 0.01 to 10 parts by weight, preferably 0.02 to 5 parts by weight, particularly preferably 0.05 to 2 parts by weight with respect to 100 parts by weight of the polymer having an alicyclic structure. Mix in proportions. When the blending amount is too small, the effect of preventing white turbidity in a high temperature and high humidity environment cannot be obtained, and when the blending amount is too large, the heat resistance and transparency of the molded product are lowered.

Other compounding agents In the resin composition of the present invention, if necessary, as other compounding agents, ultraviolet absorbers, light stabilizers, near infrared absorbers, coloring agents such as dyes and pigments, lubricants, plasticizers, Antistatic agents, fluorescent brightening agents, and the like can be blended, and these can be used alone or in combination of two or more, and the blending amount is appropriately selected within a range that does not impair the object of the present invention. .

Molding Material The resin composition of the present invention can be obtained by appropriately mixing the above components. The mixing method is not particularly limited as long as each component is sufficiently dispersed in the hydrocarbon polymer. For example, the resin is melted with a mixer, a twin-screw kneader, a roll, a Brabender, an extruder, or the like. Examples thereof include a method of kneading in a state, a method of dissolving and dispersing in a suitable solvent and solidifying. When a twin-screw kneader is used, it is often used as a molding material that is usually extruded after being kneaded into a rod shape in a molten state, cut into an appropriate length with a strand cutter, and pelletized.

(Optical element)
The optical element of the present invention is obtained by molding a molding material comprising the polymer or resin composition having the alicyclic structure. The molding method is not particularly limited, but melt molding is preferable in order to obtain a molded product excellent in characteristics such as low birefringence, mechanical strength, and dimensional accuracy. Examples of the melt molding method include press molding, extrusion molding, and injection molding, and injection molding is preferable from the viewpoints of moldability and productivity. The molding conditions are appropriately selected depending on the purpose of use or the molding method. For example, the resin temperature in the injection molding is usually appropriately selected in the range of 150 to 400 ° C, preferably 200 to 350 ° C, more preferably 230 to 330 ° C. The If the resin temperature is too low, fluidity deteriorates, causing sink marks and distortion in the molded product. If the resin temperature is too high, silver streaks occur due to thermal decomposition of the resin, and the molded product turns yellow. Defects may occur.

  The optical element according to claim 15 is the polymer block according to claim 14, wherein the polymer having an alicyclic structure contains a repeating unit [1] represented by the following formula (11): [A] and the repeating unit [1] represented by the following formula (11) and the repeating unit [2] represented by the following formula (12) or / and the repeating unit [3] represented by the following formula (13) And a polymer block [B] containing a mole fraction a (mol%) of the repeating unit [1] in the block [A], and a repeating unit [1] in the block [B]. It is a block copolymer in which the relationship with the molar fraction b (mol%) is a> b.

（式中、Ｒ¹ は水素原子、または炭素数１〜２０のアルキル基を表し、Ｒ²−Ｒ¹²はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、ヒドロキシル基、炭素数１〜２０のアルコキシ基、またはハロゲン基である。）

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ^{2 to} R ¹² each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, or 1 carbon atom. ˜20 alkoxy groups or halogen groups.)

（式中、Ｒ¹³は、水素原子、または炭素数１〜２０のアルキル基を表す。）

(In the formula, R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

（式中、Ｒ¹⁴およびＲ¹⁵はそれぞれ独立に、水素原子、または炭素数１〜２０のアルキル基を表す。）

(In the formula, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

A preferred structure of the repeating unit [1] represented by the above formula (11) is ^{one in} which R ¹ is hydrogen or a methyl group and R ² -R ¹² are all hydrogen. When the content of the repeating unit [1] in the polymer block [A] is in the above range, transparency and mechanical strength are excellent. The remainder other than the repeating unit [1] in the polymer block [A] is a hydrogenated repeating unit derived from a chain conjugated diene or a chain vinyl compound.

  The polymer block [B] contains the repeating unit [1] and the repeating unit [12] represented by the above formula (12) or / and the repeating unit [3] represented by the above formula (13). The content of the repeating unit [1] in the polymer block [B] is preferably 40 to 95 mol%, more preferably 50 to 90 mol%. When the content of the repeating unit [1] is in the above range, transparency and mechanical strength are excellent. When the molar fraction of the repeating unit [2] in the block [B] is m2 (mol%) and the molar fraction of the repeating unit [3] is m3 (mol%), 2 × m2 + m3 is preferably It is 2 mol% or more, more preferably 5 to 60 mol%, most preferably 10 to 50 mol%.

A preferred structure of the repeating unit [3] represented by the above formula (13) is one in which R ¹⁴ is hydrogen and R ¹⁵ is a methyl group or an ethyl group.

  If the content of the repeating unit [2] or the repeating unit [3] in the polymer block [B] is too small, the mechanical strength is lowered. Therefore, when the content of the repeating unit [2] and the repeating unit [3] is in the above range, transparency and mechanical strength are excellent. The polymer block [B] may further contain a repeating unit [X] represented by the following formula (X). The content of the repeating unit [X] is an amount that does not impair the properties of the block copolymer of the present invention, and is preferably 30 mol% or less, more preferably 20 mol% or less, based on the entire block copolymer. It is.

（式中、Ｒ²⁵は水素原子、または炭素数１〜２０のアルキル基を表し、Ｒ²⁶はニトリル基、アルコキシカルボニル基、ホルミル基、ヒドロキシカルボニル基、もしくはハロゲン基を表し、Ｒ²⁷は水素原子を表す。または、Ｒ²⁶とＲ²⁷とは相互に結合して、酸無水物基、もしくはイミド基を形成してもよい。）

(In the formula, R ²⁵ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ²⁶ represents a nitrile group, an alkoxycarbonyl group, a formyl group, a hydroxycarbonyl group, or a halogen group, and R ²⁷ represents a hydrogen atom. Alternatively, R ²⁶ and R ²⁷ may be bonded to each other to form an acid anhydride group or an imide group.)

  In addition, the block copolymer used in the present invention has a molar fraction of the repeating unit [1] in the polymer block [A] and a molar fraction of the repeating unit [1] in the polymer block [B]. In the case of b, there is a relationship of a> b. Thereby, it is excellent in transparency and mechanical strength.

  Furthermore, the block copolymer used in the present invention has a ratio when the number of moles of all repeating units constituting the block [A] is ma and the number of moles of all repeating units constituting the block [B] is mb. (Ma: mb) is preferably 5:95 to 95: 5, more preferably 30:70 to 95: 5, and particularly preferably 40:60 to 90:10. When (ma: mb) is in the above range, the mechanical strength and heat resistance are excellent.

  The molecular weight of the block copolymer used in the present invention is a weight average molecular weight in terms of polystyrene (or polyisoprene) measured by gel permeation chromatography (hereinafter referred to as GPC) using tetrahydrofuran (THF) as a solvent ( Hereinafter, it is described as Mw.), Preferably 10,000 to 300,000, more preferably 15,000 to 250,000, and particularly preferably 20,000 to 200,000. When the Mw of the block copolymer is in the above range, the balance of mechanical strength, heat resistance, and moldability is excellent.

  The molecular weight distribution of the block copolymer can be appropriately selected according to the purpose of use, but the ratio (Mw) of polystyrene (or polyisoprene) converted Mw and number average molecular weight (hereinafter referred to as Mn) measured by GPC. / Mn), preferably 5 or less, more preferably 4 or less, particularly preferably 3 or less. When Mw / Mn is in this range, the mechanical strength and heat resistance are excellent.

  The glass transition temperature (hereinafter referred to as Tg) of the block copolymer may be appropriately selected depending on the purpose of use, but is measured on the high temperature side by a differential scanning calorimeter (hereinafter referred to as DSC). The value is preferably 70 ° C to 200 ° C, more preferably 80 ° C to 180 ° C, and particularly preferably 90 ° C to 160 ° C.

  The block copolymer used in the present invention has a polymer block [A] and a polymer block [B], and is a ([A]-[B]) type diblock copolymer. [A]-[B]-[A]) type or ([B]-[A]-[B]) type triblock copolymer, polymer block [A] and polymer block [ B] may be a block copolymer in which a total of 4 or more are alternately connected. Moreover, the block copolymer which these blocks couple | bonded with radial type may be sufficient.

  The block copolymer used in the present invention can be obtained by the following method. As the method, an aromatic vinyl compound or / and a monomer mixture containing an alicyclic vinyl compound having an unsaturated bond in the ring, and a vinyl monomer (excluding an aromatic vinyl compound and an alicyclic vinyl compound) are used. A block having a polymer block containing a repeating unit derived from an aromatic vinyl compound and / or an alicyclic vinyl compound, and a polymer block containing a repeating unit derived from a vinyl monomer by polymerizing the monomer mixture A copolymer is obtained. And a method of hydrogenating an aromatic ring and / or an aliphatic ring of the block copolymer, a monomer mixture containing a saturated alicyclic vinyl compound, and a vinyl monomer (aromatic vinyl compound and alicyclic vinyl compound) A block copolymer having a polymer block containing a repeating unit derived from an alicyclic vinyl compound, and a polymer block containing a repeating unit derived from a vinyl monomer And the like. Especially, what is more preferable as a block copolymer used for this invention can be obtained with the following method, for example.

(1) As a first method, first, a monomer mixture [a ′] containing 50 mol% or more of an aromatic vinyl compound and / or an alicyclic vinyl compound having an unsaturated bond in the ring is polymerized to obtain an aromatic A polymer block [A ′] containing a repeating unit derived from an aliphatic vinyl compound or / and an alicyclic vinyl compound having an unsaturated bond in the ring is obtained. A monomer mixture containing a vinyl monomer (excluding an aromatic vinyl compound and an alicyclic vinyl compound) in an amount of 2 mol% or more and an aromatic vinyl compound and / or an unsaturated bond in the ring [ a ′] by polymerizing the monomer mixture [b ′] contained in an amount smaller than the proportion in the aromatic vinyl compound or / and the repeating unit derived from the alicyclic vinyl compound and the repeating derived from the vinyl monomer. A polymer block [B ′] containing units is obtained. After obtaining the block copolymer having the polymer block [A ′] and the polymer block [B ′] through at least these steps, the aromatic ring and / or the aliphatic ring of the block copolymer is hydrogenated. Turn into.

(2) As a second method, first, a polymer containing a repeating unit derived from a saturated alicyclic vinyl compound by polymerizing a monomer mixture [a] containing 50 mol% or more of a saturated alicyclic vinyl compound. A block [A] is obtained. Contains 2 mol% or more of vinyl-based monomers (excluding aromatic vinyl compounds and alicyclic vinyl compounds), and contains saturated alicyclic vinyl compounds in a proportion smaller than the proportion in the monomer mixture [a]. The monomer mixture [b] is polymerized to obtain a polymer block [B] containing a repeating unit derived from a saturated alicyclic vinyl compound and a repeating unit derived from a vinyl monomer. At least through these steps, a block copolymer having the polymer block [A] and the polymer block [B] is obtained.

  Among the above methods, the method (1) is more preferable from the viewpoints of availability of monomers, polymerization yield, ease of introduction of the repeating unit [1] into the polymer block [B ′], and the like. .

  Specific examples of the aromatic vinyl compound in the method (1) include styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-isopropylstyrene, α-t-butylstyrene, and 2-methylstyrene. 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, monochlorostyrene, dichlorostyrene, mono Examples include fluorostyrene, 4-phenylstyrene, and the like, and those having a substituent such as a hydroxyl group or an alkoxy group. Of these, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene and the like are preferable.

  Specific examples of the unsaturated alicyclic vinyl compound in the method (1) include cyclohexenylethylene, α-methylcyclohexenylethylene, α-t-butylcyclohexenylethylene, and the like, and a halogen group and an alkoxy group. Or those having a substituent such as a hydroxyl group.

  These aromatic vinyl compounds and alicyclic vinyl compounds can be used alone or in combination of two or more. In the present invention, any one of the monomer mixtures [a ′] and [b ′] In addition, it is preferable to use an aromatic vinyl compound, and it is more preferable to use styrene or α-methylstyrene.

  The vinyl monomer used in the above method includes a chain vinyl compound and a chain conjugated diene compound.

  Specific examples of the chain vinyl compound include chain olefin monomers such as ethylene, propylene, 1-butene, 1-pentene and 4-methyl-1-pentene. Among these, chain olefin monomers are preferable, and ethylene Most preferred are propylene, 1-butene.

  Examples of the chain conjugated diene include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. Of these chain vinyl compounds and chain conjugated dienes, chain conjugated dienes are preferable, and butadiene and isoprene are particularly preferable. These chain vinyl compounds and chain conjugated dienes can be used alone or in combination of two or more.

  When polymerizing a monomer mixture containing the above monomers, the polymerization reaction may be carried out by any method such as radical polymerization, anionic polymerization, cationic polymerization, etc., but preferably by anionic polymerization in the presence of an inert solvent. Most preferably, living anionic polymerization is performed.

  Anionic polymerization is usually carried out in the temperature range of 0 ° C. to 200 ° C., preferably 20 ° C. to 100 ° C., particularly preferably 20 ° C. to 80 ° C. in the presence of a polymerization initiator. Examples of the initiator include monoorganolithium such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, and phenyllithium, dilithiomethane, 1,4-diobane, 1,4-dilithio-2-ethylcyclohexane. A polyfunctional organolithium compound such as can be used.

  Examples of the inert solvent used include aliphatic hydrocarbons such as n-butane, n-pentane, isopentane, n-hexane, n-heptane, and isooctane; cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, decalin And alicyclic hydrocarbons such as benzene, toluene and the like, and the use of aliphatic hydrocarbons and alicyclic hydrocarbons is an inert solvent for hydrogenation reaction. Can be used as is. These solvents can be used alone or in combination of two or more, and are usually used at a ratio of 200 to 10,000 parts by weight with respect to 100 parts by weight of all the monomers used.

  When polymerizing each polymer block, a polymerization accelerator, a randomizer, or the like can be used in order to prevent a chain of a certain component from becoming long in each block. In particular, when the polymerization reaction is performed by anionic polymerization, a Lewis base compound or the like can be used as a randomizer. Specific examples of Lewis base compounds include ether compounds such as dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol diethyl ether, ethylene glycol methyl phenyl ether; tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, etc. Tertiary amine compounds; alkali metal alkoxide compounds such as potassium-t-amyl oxide and potassium-t-butyl oxide; phosphine compounds such as triphenylphosphine. These Lewis base compounds can be used alone or in combination of two or more.

  Examples of the method for obtaining a block copolymer by living anionic polymerization include conventionally known sequential addition polymerization reaction method and coupling method. In the present invention, it is preferable to use sequential addition polymerization reaction method.

  When the block copolymer having the polymer block [A ′] and the polymer block [B ′] is obtained by the sequential addition polymerization reaction method, a step of obtaining the polymer block [A ′], and a polymer block The process of obtaining [B ′] is performed sequentially and continuously. Specifically, in the presence of the living anion polymerization catalyst in an inert solvent, the monomer mixture [a ′] is polymerized to obtain a polymer block [A ′], and then the monomer mixture [b ′] is added to the reaction system. To continue the polymerization to obtain a polymer block [B ′] connected to the polymer block [A ′]. Furthermore, if desired, the monomer mixture [a ′] is added again for polymerization, the polymer block [A ′] is connected to form a triblock body, and the monomer mixture [b ′] is added again for polymerization. Then, a tetrablock body in which the polymer blocks [B ′] are connected is obtained.

  The obtained block copolymer is recovered by a known method such as a steam stripping method, a direct desolvation method, or an alcohol coagulation method. In the polymerization reaction, when an inert solvent is used in the hydrogenation reaction, the polymerization solution can be used as it is in the hydrogenation reaction step, so that the block copolymer need not be recovered from the polymerization solution. .

  Of the block copolymer having a polymer block [A ′] and a polymer block [B ′] obtained in the method (1) (hereinafter referred to as a pre-hydrogenation block copolymer), it has the following structure: Those having a repeating unit are preferred.

  The polymer block [A ′] constituting the preferred pre-hydrogenation block copolymer is a polymer block containing 50 mol% or more of the repeating unit [4] represented by the following formula (14).

（式中、Ｒ¹⁶は水素原子、または炭素数１〜２０のアルキル基を表し、Ｒ¹⁷−Ｒ²¹は、それぞれ独立に、水素原子、炭素数１〜２０のアルキル基、ヒドロキシル基、炭素数１〜２０のアルコキシ基またはハロゲン基である。尚、上記〔Ｒ¹⁷−Ｒ²¹〕は、Ｒ¹⁷、Ｒ¹⁸、・・およびＲ²¹を表す。）

(In the formula, R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ^{17 to} R ²¹ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, or a carbon number. 20 is a alkoxy group or a halogen group. Note that the [R ¹⁷ -R ^21] represents an R ^17, R ^18, · · and R ^21.)

  A preferred polymer block [B ′] necessarily contains the repeating unit [4], and includes a repeating unit [5] represented by the following formula (15) and a repeating unit [6] represented by the following formula (16). ] A polymer block containing at least one of the above. Further, when the mole fraction of the repeating unit [4] in the polymer block [A ′] is a ′ and the mole fraction of the repeating unit [4] in the block [B ′] is b ′, a ′> b ′.

（式中、Ｒ²²は水素原子、または炭素数１〜２０のアルキル基を表す。）

(In the formula, R ²² represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

（式中、Ｒ²³は水素原子、または炭素数１〜２０のアルキル基を表し、Ｒ²⁴は水素原子、炭素数１〜２０のアルキル基またはアルケニル基を表す。）

(Wherein R ²³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ²⁴ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an alkenyl group.)

  Further, the block [B ′] may contain a repeating unit [Y] represented by the following formula (Y).

（式中、Ｒ²⁸は水素原子、または炭素数１〜２０のアルキル基を表し、Ｒ²⁹はニトリル基、アルコキシカルボニル基、ホルミル基、ヒドロキシカルボニル基、またはハロゲン基を表し、Ｒ³⁰は水素原子を表す。または、Ｒ²⁹とＲ³⁰とは相互に結合して、酸無水物基、またはイミド基を形成してもよい。）

(In the formula, R ²⁸ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ²⁹ represents a nitrile group, an alkoxycarbonyl group, a formyl group, a hydroxycarbonyl group, or a halogen group, and R ³⁰ represents a hydrogen atom. Or R ²⁹ and R ³⁰ may be bonded to each other to form an acid anhydride group or an imide group.)

  Furthermore, a preferable block copolymer before hydrogenation is a case where the number of moles of all repeating units constituting the block [A ′] is ma ′ and the number of moles of all repeating units constituting the block [B ′] is mb ′. The ratio (ma ′: mb ′) is 5:95 to 95: 5, more preferably 30:70 to 95: 5, and particularly preferably 40:60 to 90:10. When (ma ′: mb ′) is in the above range, the mechanical strength and heat resistance are excellent.

  The molecular weight of the block copolymer before hydrogenation is preferably 12,000 to 400,000, more preferably 19,000 to 350,000, in terms of polystyrene (or polyisoprene) equivalent Mw measured by GPC using THF as a solvent. Especially preferably, it is the range of 25,000-300,000. When the Mw of the block copolymer is excessively small, the mechanical strength decreases, and when it is excessively large, the hydrogenation rate decreases.

  The molecular weight distribution of the block copolymer before hydrogenation can be appropriately selected depending on the purpose of use, but is the ratio (Mw / Mn) of Mw and Mn in terms of polystyrene (or polyisoprene) measured by GPC, It is 5 or less, more preferably 4 or less, and particularly preferably 3 or less. When Mw / Mn is in this range, the hydrogenation rate is improved.

  The Tg of the block copolymer before hydrogenation may be appropriately selected depending on the purpose of use, but is a measured value on the high temperature side by DSC, 70 ° C to 150 ° C, more preferably 80 ° C to 140 ° C, Especially preferably, it is 90 degreeC-130 degreeC.

  Method and reaction for hydrogenating the carbon-carbon unsaturated bonds of unsaturated rings such as aromatic rings and cycloalkene rings, and unsaturated bonds of main chains and side chains of the block copolymer before hydrogenation There is no particular limitation on the form, and it may be performed according to a known method. However, a hydrogenation method that can increase the hydrogenation rate and has a low polymer chain scission reaction is preferable. For example, in an organic solvent, nickel, cobalt, iron, Examples thereof include a method performed using a catalyst containing at least one metal selected from titanium, rhodium, palladium, platinum, ruthenium, and rhenium. As the hydrogenation catalyst, either a heterogeneous catalyst or a homogeneous catalyst can be used.

  The heterogeneous catalyst can be used in the form of a metal or metal compound or supported on a suitable carrier. Examples of the support include activated carbon, silica, alumina, calcium carbide, titania, magnesia, zirconia, diatomaceous earth, silicon carbide and the like, and the supported amount of the catalyst is preferably 0.01 to 80% by weight, more preferably It is in the range of 0.05 to 60% by weight. The homogeneous catalyst is a catalyst in which a nickel, cobalt, titanium or iron compound and an organometallic compound (for example, an organoaluminum compound or an organolithium compound) are combined, or an organometallic complex catalyst such as rhodium, palladium, platinum, ruthenium or rhenium. Can be used. As the nickel, cobalt, titanium, or iron compound, for example, acetylacetone salt, naphthenic acid salt, cyclopentadienyl compound, cyclopentadienyl dichloro compound and the like of various metals are used. As the organic aluminum compound, alkylaluminum such as triethylaluminum and triisobutylaluminum, aluminum halide such as diethylaluminum chloride and ethylaluminum dichloride, alkylaluminum hydride such as diisobutylaluminum hydride and the like are preferably used.

  As an example of the organometallic complex catalyst, metal complexes such as γ-dichloro-π-benzene complex, dichloro-tris (triphenylphosphine) complex, hydrido-chloro-triphenylphosphine complex of the above metals are used. These hydrogenation catalysts can be used alone or in combination of two or more, and the amount used is preferably 0.01 to 100 parts by weight, more preferably 100 parts by weight of the polymer. 0.05 to 50 parts by weight, particularly preferably 0.1 to 30 parts by weight.

  The hydrogenation reaction is usually 10 ° C. to 250 ° C., but is preferably 50 ° C. to 200 ° C., more preferably 80 ° C. to 80 ° C., because the hydrogenation rate can be increased and the polymer chain cleavage reaction can be reduced. 180 ° C. The hydrogen pressure is preferably 0.1 MPa to 30 MPa, but in addition to the above reasons, it is more preferably 1 MPa to 20 MPa, and particularly preferably 2 MPa to 10 MPa from the viewpoint of operability.

  The hydrogenation rate of the block copolymer thus obtained was determined by 1H-NMR as measured by carbon-carbon unsaturated bonds in the main chain and side chains, carbon-carbon unsaturation in aromatic rings and cycloalkene rings. Any of the bonds is preferably 90% or more, more preferably 95% or more, and particularly preferably 97% or more. When the hydrogenation rate is low, the low birefringence, thermal stability, etc. of the resulting copolymer are lowered.

  After completion of the hydrogenation reaction, the block copolymer is prepared by removing the hydrogenation catalyst from the reaction solution by a method such as filtration or centrifugation, and then removing the solvent directly by drying. It can be recovered by a method such as pouring into a poor solvent and solidifying.

  Various compounding agents can be blended with the block copolymer according to the present invention obtained by the above method, if necessary. There are no particular limitations on the compounding agents that can be incorporated into the block copolymer, but stabilizers such as antioxidants, heat stabilizers, light stabilizers, weather stabilizers, ultraviolet absorbers, near infrared absorbers, lubricants, Resin modifiers such as plasticizers; colorants such as dyes and pigments; antistatic agents, flame retardants, fillers and the like. These compounding agents can be used alone or in combination of two or more, and the compounding amount is appropriately selected within a range not impairing the effects of the present invention.

  In this invention, it is preferable to mix | blend an antioxidant, a ultraviolet absorber, and a light-resistant stabilizer among the said compounding agents with a block copolymer. Examples of the antioxidant include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among them, phenolic antioxidants, particularly alkyl-substituted phenolic antioxidants are preferable. By blending these antioxidants, it is possible to prevent lens coloring and strength reduction due to oxidative degradation during molding without reducing transparency, heat resistance and the like. These antioxidants can be used singly or in combination of two or more, and the blending amount thereof is appropriately selected within a range that does not impair the object of the present invention. Preferably it is 0.001-5 weight part with respect to 100 weight part of coalescence, More preferably, it is 0.01-1 weight part.

  Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2 -Hydroxy-4-methoxy-2'-benzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2-hydroxy-4-n-octoxybenzophenone, 2,2 ', 4,4'- Benzophenone ultraviolet absorbers such as tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane; 2- (2′-hydroxy-5′-methyl-) Phenyl) benzotriazole, 2- (2H Benzotriazol-2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2H-benzotriazol-2-yl) -4-6-bis ( 1-methyl-1-phenylethyl) phenol, 2- (2′-hydroxy-3 ′, 5′-di-tert-butyl-phenyl) benzotriazole, 2- (2′-hydroxy-3′-tertiary) -Butyl-5'-methyl-phenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'- Di-tertiary-amylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methyl Benzotriazole-based UV absorbers such as benzyl] benzotriazole and 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] Etc. Among these, 2- (2′-hydroxy-5′-methyl-phenyl) benzotriazole, 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4,5,6- Tetrahydrophthalimidylmethyl) phenol, 2- (2H-benzotriazol-2-yl) -4-6-bis (1-methyl-1-phenylethyl) phenol and the like are preferable from the viewpoints of heat resistance and low volatility. .

  Examples of the light-resistant stabilizer include benzophenone-based light-resistant stabilizer, benzotriazole-based light-resistant stabilizer, hindered amine-based light-resistant stabilizer, etc., but in the present invention, from the viewpoint of lens transparency, color resistance, etc., hindered amine-based It is preferable to use a light-resistant stabilizer. Among hindered amine light-resistant stabilizers (hereinafter referred to as HALS), those having a polystyrene-equivalent Mn of 1000 to 10,000 as measured by GPC using THF as a solvent are preferred, and those having 2000 to 5000 are more preferred. What is 2800-3800 is especially preferable. When Mn is too small, when HALS is blended by heat-melting and kneading into a block copolymer, a predetermined amount cannot be blended due to volatilization, foaming or silver streak occurs during heat-melt molding such as injection molding, etc. Processing stability decreases. Further, when the lens is used for a long time with the lamp turned on, a volatile component is generated as a gas from the lens. Conversely, if Mn is too large, the dispersibility in the block copolymer is lowered, the transparency of the lens is lowered, and the effect of improving light resistance is reduced. Therefore, in the present invention, a lens excellent in processing stability, low gas generation and transparency can be obtained by setting the HALS Mn in the above range.

  Specific examples of such HALS include N, N ′, N ″, N ′ ″-tetrakis- [4,6-bis- {butyl- (N-methyl-2,2,6,6-tetra Methylpiperidin-4-yl) amino} -triazin-2-yl] -4,7-diazadecane-1,10-diamine, dibutylamine and 1,3,5-triazine and N, N′-bis (2,2 , 6,6-tetramethyl-4-piperidyl) butylamine, poly [{(1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl } {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], 1,6-hexanediamine- N, N′-bis (2,2,6,6-tetramethyl- Polypiperidyl) and morpholine-2,4,6-trichloro-1,3,5-triazine, poly [(6-morpholino-s-triazine-2,4-diyl) (2,2, 6,6, -tetramethyl-4-piperidyl) imino] -hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] and other piperidine rings are bonded via a triazine skeleton High molecular weight HALS; a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 1,2,3,4-butanetetracarboxylic acid and 1,2, Between 2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane Examples thereof include high molecular weight HALS in which piperidine rings are bonded through an ester bond, such as a mixed ester product.

  Among these, polycondensates of dibutylamine, 1,3,5-triazine and N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [{(1, 1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2 , 2,6,6-tetramethyl-4-piperidyl) imino}], a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol and the like. 5,000 to 5,000 are preferred.

  The blending amount of the UV absorber and HALS with respect to the block copolymer according to the present invention is preferably 0.01 to 20 parts by weight, more preferably 0.02 to 15 parts by weight, with respect to 100 parts by weight of the polymer. Particularly preferred is 0.05 to 10 parts by weight. If the amount added is too small, the effect of improving light resistance cannot be obtained sufficiently, and coloring occurs when used outdoors for a long time. On the other hand, when the HALS content is too large, a part of the HALS is generated as a gas, or the dispersibility in the block copolymer is lowered, and the transparency of the lens is lowered.

  In addition, by blending a soft polymer having the lowest glass transition temperature of 30 ° C. or less into the block polymer according to the present invention, without reducing various properties such as transparency, heat resistance, and mechanical strength, It can prevent cloudiness in long-term high temperature and high humidity environment.

  Specific examples of the soft polymer include olefin-based soft polymers such as polyethylene, polypropylene, ethylene-α-olefin copolymer, ethylene-propylene-diene copolymer (EPDM); polyisobutylene, isobutylene-isoprene rubber, Isobutylene-based soft polymers such as isobutylene-styrene copolymer; polybutadiene, polyisoprene, butadiene-styrene random copolymer, isoprene-styrene random copolymer, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer Butadiene-styrene block copolymer, styrene-butadiene-styrene block copolymer, isoprene-styrene block copolymer, styrene-isoprene-styrene block copolymer -Based soft polymers; silicon-containing soft polymers such as dimethylpolysiloxane and diphenylpolysiloxane; acrylic soft polymers such as polybutyl acrylate, polybutyl methacrylate, and polyhydroxyethyl methacrylate; polyethylene oxide, polypropylene oxide, epichlorohydrin rubber, etc. Epoxy soft polymer; Fluorine soft polymer such as vinylidene fluoride rubber and tetrafluoroethylene-propylene rubber; natural rubber, polypeptide, protein, polyester thermoplastic elastomer, vinyl chloride thermoplastic elastomer, polyamide Other soft polymers such as thermoplastic elastomers can be mentioned. These soft polymers may have a cross-linked structure or may have a functional group introduced by a modification reaction.

  Among the above-mentioned soft polymers, diene-based soft polymers are preferable. In particular, hydrides obtained by hydrogenating carbon-carbon unsaturated bonds of the soft polymers are advantageous in terms of rubber elasticity, mechanical strength, flexibility, and dispersibility. Excellent. The blending amount of the soft polymer varies depending on the type of the compound, but generally, if the blending amount is too large, the glass transition temperature and transparency of the block copolymer are greatly reduced, and cannot be used as a lens. On the other hand, if the blending amount is too small, the molded product may become clouded under high temperature and high humidity. The amount is preferably 0.01 to 10 parts by weight, more preferably 0.02 to 5 parts by weight, and particularly preferably 0.05 to 2 parts by weight with respect to 100 parts by weight of the block copolymer.

  The method of forming the block copolymer composition by blending the above-mentioned compounding agent with the block copolymer used in the present invention is, for example, block copolymerization using a mixer, a twin-screw kneader, a roll, a Brabender, an extruder, etc. Examples thereof include a method in which the coalescence is melted and kneaded with the compounding agent, and a method in which it is dissolved and dispersed in a suitable solvent and solidified. When a twin-screw kneader is used, it is often used after being kneaded and usually extruded in the form of a strand in a molten state and cut into a pellet by a pelletizer.

  In addition to the above resins, for example, a resin containing a norbornene-based ring-opening (hydrogen) polymer described in JP-A-2003-73460 can also be used as the material of the optical element of the present invention.

The optical pickup device according to claim 16, wherein a light source that emits light having a wavelength λ1 that satisfies 350 nm ≦ λ1 ≦ 450 nm, an optical element that is disposed at a position through which a light beam emitted from the light source passes, and the optical An optical pickup device for recording and / or reproducing information, comprising an objective lens for condensing a light beam from the light source that has passed through an element onto an information recording surface of an optical information recording medium,
The optical element is based on a resin,
The resin is a resin containing a polymer having an alicyclic structure,
An antireflection film is formed on at least one optical surface of the optical element, and the antireflection film has a low refractive index layer having a first refractive index when a light beam having the wavelength λ is passed, and the wavelength. a high refractive index layer having a second refractive index higher than the first refractive index when passing a light beam of λ,
The low refractive index layer is formed of silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or a mixture thereof, and the high refractive index layer is Scandium oxide, niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, tantalum oxide and titanium mixture, silicon nitride or a mixture thereof It is characterized by that.

  The optical pickup device according to claim 17 is the optical pickup device according to claim 16, wherein the high refractive index layer includes scandium oxide, lanthanum oxide, lanthanum aluminate, praseodymium titanate, lanthanum titanate, hafnium oxide, and zirconium oxide. , Tantalum oxide, a mixture of tantalum oxide and titanium, silicon nitride, or a mixture thereof.

  The optical pickup device according to claim 18 is the optical pickup device according to claim 16, wherein the high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, hafnium oxide, zirconium oxide, tantalum oxide, silicon nitride, or the like. It is formed by the mixture of these.

  The optical pickup device according to claim 19 is the invention according to any one of claims 16 to 18, wherein the antireflection film is formed on a resin base material in the order of the high refractive index layer and the low refractive index layer. It is characterized by having a laminated two-layer structure.

  An optical pickup device according to a twentieth aspect is the invention according to any one of the sixteenth to eighteenth aspects, wherein the antireflection film is formed on a resin base material with the low refractive index layer, the high refractive index layer, It has a three-layer structure in which low refractive index layers are stacked in this order.

  An optical pickup device according to a twenty-first aspect is the invention according to any one of the sixteenth to eighteenth aspects, wherein the antireflective film further causes the light beam having the wavelength λ to pass through the first refractive index. A medium refractive index layer having a third refractive index that is higher but lower than the second refractive index, the medium refractive index layer being lanthanum fluoride, neodymium fluoride, cerium fluoride, aluminum fluoride, lanthanum aluminum It is characterized in that it is formed of nate, lead fluoride, aluminum oxide, or a mixture thereof.

  An optical pickup device according to a twenty-second aspect is the invention according to any one of the sixteenth to eighteenth and twenty-first aspects, wherein the antireflection film has a layer configuration in which four or more layers are laminated on a resin base material surface. Features.

An optical pickup device according to a twenty-third aspect is the invention according to the twenty-first aspect, wherein the antireflection film is formed in a laminated structure including four layers on a resin base material surface. When the layer closest to the surface is the first layer, and the layer number increases as you move away from the surface of the base material,
Laminating in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n4 are the refractive index of the material, and d1 to d4 are the thickness of the material,
First layer: 1.7 ≦ n1, 15 nm ≦ d1 ≦ 36 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 25 nm ≦ d2 ≦ 40 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 150 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 90 nm ≦ d4 ≦ 115 nm
It is characterized by that.

An optical pickup device according to a twenty-fourth aspect is the invention according to the twenty-first aspect, wherein the antireflection film is formed in a laminated structure including five layers on a resin base material surface. When the layer closest to the surface is the first layer, and the layer number increases as you move away from the surface of the base material,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n5 are the refractive index of the material, and d1 to d5 are the thickness of the material. Well,
First layer: 1.2 ≦ n1 ≦ 1.55, 5 nm ≦ d1 ≦ 20 nm
Second layer: 1.7 ≦ n2, 15 nm ≦ d2 ≦ 35 nm
3rd layer: 1.2 ≦ n3 ≦ 1.55, 25 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 50 nm ≦ d4 ≦ 130 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 80 nm ≦ d5 ≦ 110 nm
It is characterized by that.

An optical pickup device according to claim 25 is characterized in that, in the invention according to claim 21, the antireflection film is formed in a laminated structure comprising six layers on the surface of the resin substrate. When the layer closest to the surface is the first layer, and the layer number increases as you move away from the surface of the base material sequentially,
Laminate in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, where n1 to n6 are the refractive indices of the materials, d1 d6 is the thickness of the material,
First layer: 1.7 ≦ n1, 8 nm ≦ d1 ≦ 15 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 35 nm ≦ d2 ≦ 55 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 60 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 10 nm ≦ d4 ≦ 17 nm
5th layer: 1.7 ≦ n5, 45 nm ≦ d5 ≦ 90 nm
Sixth layer: 1.2 ≦ n6 ≦ 1.55, 70 nm ≦ d6 ≦ 110 nm
It is characterized by that.

An optical pickup device according to a twenty-sixth aspect is the optical pickup device according to the twenty-first aspect, wherein the antireflection film is formed in a laminated structure including seven layers on a resin base material surface. When the layer closest to the surface is the first layer, and the layer number increases as you move away from the surface of the substrate in sequence,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material. Refractive index, d1-d7 is the thickness of the material,
First layer: 1.2 ≦ n1 ≦ 1.55, 80 nm ≦ d1 ≦ 160 nm
Second layer: 1.7 ≦ n2, 10 nm ≦ d2 ≦ 25 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 33 nm ≦ d3 ≦ 45 nm
Fourth layer: 1.7 ≦ n4, 40 nm ≦ d4 ≦ 85 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 10 nm ≦ d5 ≦ 20 nm
6th layer: 1.7 ≦ n6, 6 nm ≦ d6 ≦ 70 nm
Seventh layer: 1.2 ≦ n7 ≦ 1.55, 60 nm ≦ d7 ≦ 110 nm
It is characterized by that.

In an optical pickup device according to a twenty-seventh aspect, in the invention according to any one of the twenty-second to twenty-fifth aspects, the low refractive index layer is silicon oxide or a mixture of silicon oxide and aluminum oxide, or a mixture thereof. And is formed by
The high refractive index layer is formed of hafnium oxide, lanthanum aluminate, zirconium oxide, tantalum oxide, silicon nitride, or a mixture thereof.

  An optical pickup device according to a twenty-eighth aspect is the invention according to any one of the sixteenth to twenty-seventh aspects, wherein the pickup device has a wavelength λ2 and 760 nm satisfying 620 nm ≦ λ2 ≦ 670 nm in addition to a light source having a wavelength λ1. A light source that emits light of at least one wavelength of wavelength λ3 that satisfies ≦ λ3 ≦ 800 nm is provided, and the light from the plurality of light sources is transmitted through the optical element.

  An optical pickup device according to a twenty-ninth aspect is the invention according to any one of the sixteenth to twenty-eighth aspects, wherein the optical element is an objective lens. However, the “optical element” is not limited thereto, and examples thereof include a collimator lens, an expander lens, a lens, a prism, a diffraction grating optical element (a diffraction lens, a diffraction prism, a diffraction plate, a chromatic aberration correction element), an optical filter (a spatial low-pass filter, Wavelength bandpass filter, wavelength lowpass filter, wavelength highpass filter, etc.), polarizing filter (analyzer, optical rotator, polarization separating prism, etc.), phase filter (phase plate, hologram, etc.), etc. .

  The optical pickup device according to claim 30 is the invention according to any one of claims 16 to 29, wherein the polymer having an alicyclic structure has a weight average molecular weight (Mw) of 1,000 to 1,000. , 000 in all the repeating units of the polymer, the repeating unit (a) having an alicyclic structure represented by the following general formula (1), the following general formula (2) and / or the following general formula (3) The repeating unit (b) having a chain structure represented by the formula (1) is contained so that the total content is 90% by weight or more, and the content of the repeating unit (b) is 1% by weight or more and less than 10% by weight. It is characterized by being. Particularly, in the polymer, the chain of the repeating unit (a) has a relational expression A ≦ 0.3 × B (where A = (weight average molecular weight of the chain of repeating unit having an alicyclic structure), B = ( What satisfies the weight average molecular weight (Mw) of the alicyclic hydrocarbon copolymer) × (number of repeating units having an alicyclic structure / number of all repeating units constituting the alicyclic hydrocarbon copolymer)) It is preferable that

〔式（１）中、Ｘは脂環式炭化水素基であり、式（１）、式（２）、及び式（３）中、Ｒ１〜Ｒ１３は、それぞれ独立に水素原子、鎖状炭化水素基、ハロゲン原子、アルコキシ基、ヒドロキシ基、エーテル基、エステル基、シアノ基、アミド基、イミド基、シリル基、及び極性基（ハロゲン原子、アルコキシ基、ヒドロキシ基、エーテル基、エステル基、シアノ基、アミド基、イミド基、又はシリル基）で置換された鎖状炭化水素基である。式（３）中……は炭素−炭素飽和結合、又は不飽和結合である。〕

[In Formula (1), X is an alicyclic hydrocarbon group, and in Formula (1), Formula (2), and Formula (3), R1 to R13 are each independently a hydrogen atom or a chain hydrocarbon. Group, halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group, amide group, imide group, silyl group, and polar group (halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group , An amide group, an imide group, or a silyl group). In formula (3),... Is a carbon-carbon saturated bond or an unsaturated bond. ]

  The optical pickup device according to claim 31 is the polymer according to claim 30, wherein the polymer having the alicyclic structure includes a repeating unit [1] represented by the following formula (11): Block [A], a repeating unit [1] represented by the following formula (11) and a repeating unit [2] represented by the following formula (12) or / and a repeating unit represented by the following formula (13) [ 3] containing the polymer block [B], the mole fraction a (mol%) of the repeating unit [1] in the block [A], and the repeating unit [1] in the block [B]. ] Is a block copolymer in which a> b in relation to the molar fraction b (mol%).

（式中、Ｒ¹ は水素原子、または炭素数１〜２０のアルキル基を表し、Ｒ²−Ｒ¹²はそれぞれ独立に、水素原子、炭素数１〜２０のアルキル基、ヒドロキシル基、炭素数１〜２０のアルコキシ基、またはハロゲン基である。）

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ^{2 to} R ¹² each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, or 1 carbon atom. ˜20 alkoxy groups or halogen groups.)

（式中、Ｒ¹³は、水素原子、または炭素数１〜２０のアルキル基を表す。）

(In the formula, R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

（式中、Ｒ¹⁴およびＲ¹⁵はそれぞれ独立に、水素原子、または炭素数１〜２０のアルキル基を表す。）

(In the formula, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

  ADVANTAGE OF THE INVENTION According to this invention, the optical element which formed the antireflection film in the synthetic resin which can suppress deterioration of an optical characteristic even if it irradiates with a short wavelength laser beam, and an optical pick-up apparatus using the same can be provided.

  FIG. 1 is a schematic sectional view of an optical pickup apparatus capable of recording / reproducing information with respect to a BD (Blu-ray Disc) or AOD (Advanced Optical Disc) as an information recording medium (also referred to as an optical disc).

  As shown in FIG. 1, the optical pickup device PU includes a semiconductor laser LD serving as a light source. The semiconductor laser LD is a GaN blue-violet semiconductor laser or SHG blue-violet laser that emits a light beam having a wavelength of about 400 nm. The divergent light beam emitted from the semiconductor laser LD passes through the polarization beam splitter BS, becomes a circularly polarized light beam through the quarter-wave plate WP, and then becomes a parallel light beam by the collimator lens COL.

  This parallel light beam is incident on the expander lens EXP. The light beam that has passed through the expander lens EXP becomes a condensed spot formed on the information recording surface DR via the protective layer DP of the optical disk OD by the objective lens OBJ after the diameter of the light beam is enlarged and the aperture stop ST. The objective lens OBJ is driven in the focus direction and the tracking direction by a biaxial actuator AC1 disposed around the objective lens OBJ.

  The objective lens OBJ is integrally assembled by fitting flange portions FL1 and FL2 formed integrally with the optical surfaces of the respective lens groups E1 and E2. And it can attach to optical pick-up apparatus PU with high precision by the flange part FL1 of the 1st lens group E1. The reflected light beam modulated by the information pits on the information recording surface DR again passes through the objective lens OBJ, the aperture stop ST, and the expander lens EX, and then becomes a converged light beam by the collimating lens COL. This convergent light beam is linearly polarized by the quarter-wave plate WP, then reflected by the polarization beam splitter BS, and given astigmatism by passing through the cylindrical lens CY and the concave lens NL, and received by the photodetector PD. Converge on the surface. Information can be recorded / reproduced with respect to the optical disc OD using a focus error signal and a tracking error signal generated based on the output signal of the photodetector PD.

  The information recording / reproducing apparatus includes the above-described optical pickup apparatus PU and an optical information recording medium support means (not shown) that supports the optical disk OD so that information can be recorded / reproduced by the optical pickup apparatus. Can. The optical information recording medium support means is constituted by a rotation operation device that holds and rotates the center portion of the optical disc OD.

For example, when forming a film on the optical surface of the expander lens EX or the collimator lens COL as well as the objective lens OBJ used in the optical pickup apparatus shown in FIG. 1, the surface of the substrate is formed by a vacuum deposition method, a sputtering method, or a CVD method. An antireflection film is formed. In the case of the vacuum vapor deposition method, an electron gun heating apparatus that heats a predetermined vapor deposition material is used as a vapor deposition source, and an electron gun heating apparatus is heated while heating the substrate with a halogen lamp or a sheathed heater so as to be 70 ° C to 130 ° C. In the vacuum for holding the deposition material and the substrate, oxygen gas, inert gas (eg, argon gas or nitrogen gas), hydrogen gas, CF4 gas or the like is introduced alone or in a mixed state, and 0.2 to 5E ⁻² Pa. While maintaining the degree of vacuum, film formation can be performed while controlling the thickness of the layer deposited on the surface of the substrate by a crystal film thickness control method, an optical monitor control method, or the like.

The film configuration is shown below. Here, ni represents the refractive index of the i-th layer, and di represents the thickness of the i-th layer.
(1) Two-layer structure: laminated in the order of resin base material / high refractive index material / low refractive index material family.
First layer: 1.7 ≦ n1, 15 nm ≦ d1 ≦ 91 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 30 nm ≦ d2 ≦ 118 nm
(2) Three-layer structure: laminated in the order of resin base material / low refractive index material / high refractive index material / low refractive index material.
First layer: 1.2 ≦ n1 ≦ 1.55, 10 nm ≦ d1 ≦ 130 nm
Second layer: 1.7 ≦ n2, 20 nm ≦ d2 ≦ 110 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 35 nm ≦ d3 ≦ 90 nm
(3) Three-layer structure: laminated in the order of resin base material / medium refractive index material / high refractive index material / low refractive index material.
First layer: 1.55 ≦ n1 ≦ 1.7, 40 nm ≦ d1 ≦ 110 nm
Second layer: 1.7 ≦ n2, 35 nm ≦ d2 ≦ 90 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 45 nm ≦ d3 ≦ 85 nm
(4) Four-layer configuration: laminated in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material.
First layer: 1.7 ≦ n1, 15 nm ≦ d1 ≦ 36 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 25 nm ≦ d2 ≦ 40 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 150 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 90 nm ≦ d4 ≦ 115 nm
(5) Five-layer structure: laminated in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material.
First layer: 1.2 ≦ n1 ≦ 1.55, 5 nm ≦ d1 ≦ 20 nm
Second layer: 1.7 ≦ n2, 15 nm ≦ d2 ≦ 35 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 25 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 50 nm ≦ d4 ≦ 130 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 80 nm ≦ d5 ≦ 110 nm
(6) Six-layer configuration: laminated in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material.
First layer: 1.7 ≦ n1, 8 nm ≦ d1 ≦ 15 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 35 m ≦ d2 ≦ 55 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 60 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 10 nm ≦ d4 ≦ 17 nm
5th layer: 1.7 ≦ n5, 45 nm ≦ d5 ≦ 90 nm
Sixth layer: 1.2 ≦ n6 ≦ 1.55, 70 nm ≦ d6 ≦ 110 nm
(7) 7-layer configuration: laminated in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material .
First layer: 1.2 ≦ n1 ≦ 1.55, 80 nm ≦ d1 ≦ 140 nm
Second layer: 1.7 ≦ n2, 10 nm ≦ d2 ≦ 25 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 30 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 40 nm ≦ d4 ≦ 60 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 10 nm ≦ d5 ≦ 20 nm
6th layer: 1.7 ≦ n6, 6 nm ≦ d6 ≦ 70 nm
Seventh layer: 1.2 ≦ n7 ≦ 1.55, 60 nm ≦ d7 ≦ 100 nm

  In order to investigate the specifications of the antireflection film and the optical characteristics of the optical element do not deteriorate, the inventors of the present invention applied a vacuum deposition method or a sputtering method to a test resin substrate having a diameter of 30 mm and a thickness of 3 mm. As shown in Tables 1 to 11, samples of Examples 1 to 40 and Comparative Examples 1 to 10 are prepared as shown in Tables 1 to 11, and laser irradiation tests, light absorption measurements, and environmental resistances are prepared. A sex test was conducted and evaluated. As a resin material for the test resin substrate, an acrylic resin and a polycarbonate resin were used for comparison in addition to “resin 1” described in detail below.

Resin 1
(Manufacture of polymer)
A stainless steel polymerization vessel equipped with a stirrer and thoroughly dried and purged with nitrogen was charged with 320 parts of dehydrated cyclohexane, 60 parts of styrene, and 0.38 part of dibutyl ether, and stirred at 60 ° C. to obtain an n-butyllithium solution. (15% containing hexane solution) 0.36 parts is added to initiate the polymerization reaction. After carrying out the polymerization reaction for 1 hour, 20 parts of a mixed monomer composed of 8 parts of styrene and 12 parts of isoprene was added to the reaction solution, and after further carrying out the polymerization reaction for 1 hour, 0.2 parts of isopropyl alcohol was added to the reaction solution. Add the portion to stop the reaction. Mw of the block copolymer obtained at this time is 102,100, and Mw / Mn is 1.11.

  Next, 400 parts of the polymerization reaction solution was transferred to a pressure-resistant reactor equipped with a stirrer, and a silica-alumina supported nickel catalyst (manufactured by JGC Chemical Industry Co., Ltd .; E22U, nickel supported amount 60%) 10 as a hydrogenation catalyst. Add portion and mix. Hydrogen is supplied to the aromatic ring by replacing the inside of the reactor with hydrogen gas, supplying hydrogen while stirring the solution, setting the temperature to 160 ° C., and reacting at a pressure of 4.5 MPa for 8 hours. . After completion of the hydrogenation reaction, the reaction solution is filtered to remove the hydrogenation catalyst, and then diluted by adding 800 parts of cyclohexane and the reaction solution is filtered with 3500 parts of isopropanol (class 1000 clean room with a filter having a pore size of 1 μm. The block copolymer is precipitated by filtration into a filtered product), separated and recovered by filtration, and dried under reduced pressure at 80 ° C. for 48 hours. The block copolymer thus obtained is a binary comprising a block containing a repeating unit derived from styrene (hereinafter referred to as St) and a block containing a repeating unit derived from styrene and isoprene (hereinafter referred to as St / Ip). It is a block copolymer, and the molar ratio of each block is St: St / Ip = 69: 31 (St: Ip = 10: 21). The block copolymer has an Mw of 85,100, Mw / Mn of 1.17, a hydrogenation rate of the main chain and the aromatic ring of 99.9%, and Tg of 126.5 ° C.

(Manufacture of resin)
With respect to 100 parts of the block copolymer obtained by the production of the above polymer, 0.1 part of styrene-ethylene-butylene-styrene block copolymer (manufactured by Kuraray Co., Septon 2002) and tetrakis as an antioxidant [Methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] 0.1 part of methane (manufactured by Ciba Specialty Chemicals, Irganox 1010), and benzotriazole-based ultraviolet rays As an absorbent, 0.1 part of 2- (2′-hydroxy-5′-methyl-phenyl) benzotriazole (manufactured by Ciba Specialty Chemicals, TINUVIN P), further HALS, dibutylamine and 1,3,3 5-Triazine / N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) -1 , 6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate [HALS (A), Mn = 3,000] 0.1 parts were added respectively. Kneading with a twin-screw kneader (Toshiba Machine Co., Ltd., TEM-35B, screw diameter 37 mm, L / D = 32, screw rotation speed 150 rpm, resin temperature 240 ° C., feed rate 10 kg / hour), and extruded into a strand shape This is cooled with water, cut with a pelletizer, and pelletized to obtain resin 1.

  In addition to the resin 1 obtained as described above, each pellet of acrylic resin and polycarbonate resin was dried at 70 ° C. for 2 hours using a hot air dryer in which air was circulated to remove moisture, and then injected. The resin base material for a test was obtained by molding.

(Laser irradiation test 1)
FIG. 2 is a diagram showing an outline of a laser beam irradiation test apparatus conducted by the present inventors. In FIG. 2, a laser beam having a wavelength λ = 405 to 415 nm is emitted from a semiconductor laser LD, and is condensed on an antireflection film M of the example and the comparative example on the substrate S while being condensed using a condenser lens L. The surface was irradiated with laser light for a time and the surface was observed with a microscope. At this time, the power density on the substrate S was 120 mW / mm ² , the heating temperature of the substrate S was 85 ° C., and the humidity of the atmosphere was 5%. As a result of the observation, ◎ indicates that the surface was almost free of wrinkles and the film was not peeled off, and ◯ indicates that the surface was observed to have very small wrinkles but no film was peeled off. Evaluations were made by assuming that fine wrinkles or the like were observed but the film was not peeled off as Δ, and changes in shape such as wrinkles or cracks were clearly observed and the film was peeled off as x.

(Laser irradiation test 2)
Under the same conditions as in the laser light irradiation test 1, the irradiation time was 250 hours, and then the surface of the sample was observed with a microscope. As a result of observation in the same manner, the surface where almost no wrinkles or the like was observed on the surface and the film was not peeled was marked with ◎, and the surface where very small wrinkles were confirmed but the film was not peeled off was marked with ○, Evaluation was made by assuming that a fine wrinkle or the like was observed on the surface but there was no film peeling, and that a change in shape such as wrinkles or cracks was clearly observed and a film peeling occurred as x. .

(Light transmittance measurement)
A light flux having a wavelength of λ = 405 nm is incident on the sample, and the transmittance T and reflectance R (total reflectance of the incident surface and the exit surface) are measured with a spectrophotometer (manufactured by Hitachi, Ltd., product name UP-4000). The light absorption (%) was measured and calculated by 100-TR. As a result, when the light absorption amount is less than 0.1%, ◎, when the light absorption amount is 0.1% or more and less than 0.5%, ○, and the light absorption amount is 0.5% or more and 2 Evaluations were made with Δ being less than% and Δ with light absorption being 2% or more. FIG. 3 shows a graph showing the reflection characteristics of Examples 10, 16, and 28, and FIG. 4 shows a graph showing the reflection characteristics of Examples 32, 36, and 39.

(Environmental test)
The sample was allowed to stand for 168 hours in a high temperature (60 ° C.) and high humidity (90%) environment, and then the appearance was visually observed. As a result, ◎ indicates that there is no abnormal appearance such as film peeling or cracking, and ◯ indicates that there is no film peeling but very small cracks (streaks), and there is no film peeling. Evaluations were made by making a case where a slight crack was seen as Δ and a case where peeling of the film or a crack (tortoid shape) was clearly seen as x.

  Based on these evaluation results, the present inventors performed a comprehensive evaluation as to whether or not the optical element has characteristics suitable for an optical pickup device using a short-wavelength laser beam. In the overall evaluation, when used in an optical pickup device using a laser beam with a short wavelength, ◎ indicates that the reliability is very high, and ○ indicates that the reliability can be determined when used in the same manner. For the time being, Δ was determined to be usable for an optical pickup device using a short-wavelength laser beam. Table 12 summarizes the above evaluation results.

  From the above test results, at least of the antireflection film of the optical element, the low refractive index layer is silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or these The high refractive index layer is formed of a mixture and is composed of scandium oxide, niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, silicon nitride or In the case of being formed of these mixtures, it can be seen that even when used in an optical system of an optical pickup device having a short-wavelength laser light source, deterioration of optical characteristics can be suppressed over a long period of time.

  The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate.

1 is a schematic sectional view of an optical pickup device capable of recording / reproducing information with respect to an optical disc. FIG. 2 is a diagram showing an outline of a laser beam irradiation test apparatus conducted by the present inventors. It is a graph which shows the reflective characteristic of Example 10, 16, 28, and shows a reflectance on a vertical axis | shaft and shows a wavelength on a horizontal axis. It is a graph which shows the reflective characteristic of Example 32, 36, 39, and shows a reflectance on a vertical axis | shaft and shows a wavelength on a horizontal axis.

Explanation of symbols

PU Optical pickup device LD Semiconductor laser OD Optical disc PD Photodetector BS Beam splitter COL Collimator lens OBJ Objective lens CY Cylindrical lens

Claims (31)

An optical element based on a resin used in an optical device including a light source that emits light having a wavelength λ1 that satisfies 350 nm ≦ λ1 ≦ 450 nm,
The resin is a resin containing a polymer having an alicyclic structure,
An antireflection film is formed on at least one optical surface of the optical element, and the antireflection film has a low refractive index layer having a first refractive index when a light beam having the wavelength λ is passed, and the wavelength. a high refractive index layer having a second refractive index higher than the first refractive index when passing a light beam of λ,
The low refractive index layer is formed of silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or a mixture thereof,
The high refractive index layer is scandium oxide, niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, a mixture of tantalum oxide and titanium, silicon nitride or An optical element characterized by being formed of a mixture thereof.   The high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, praseodymium titanate, lanthanum titanate, hafnium oxide, zirconium oxide, tantalum oxide, a mixture of tantalum oxide and titanium, silicon nitride, or a mixture thereof. The optical element according to claim 1.   2. The optical element according to claim 1, wherein the high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, hafnium oxide, zirconium oxide, tantalum oxide, silicon nitride, or a mixture thereof.   4. The optical system according to claim 1, wherein the antireflection film has a two-layer structure in which the high refractive index layer and the low refractive index layer are laminated in this order on a resin base material. element.   The antireflection film has a three-layer structure in which the low refractive index layer, the high refractive index layer, and the low refractive index layer are laminated in this order on a resin base material. The optical element in any one.   The antireflection film further includes a middle refractive index layer having a third refractive index higher than the first refractive index but lower than the second refractive index when the light flux having the wavelength λ is allowed to pass through, The medium refractive index layer is formed of lanthanum fluoride, neodymium fluoride, cerium fluoride, aluminum fluoride, lanthanum aluminate, lead fluoride, aluminum oxide, or a mixture thereof. The optical element in any one of 1-3.   The optical element according to claim 1, wherein the antireflection film has a layer structure in which four or more layers are laminated on the surface of a resin base material. The antireflection film is characterized in that it is formed in a laminated structure consisting of four layers on the surface of the resin base material, the layer closest to the surface of the base material is the first layer, and gradually away from the surface of the base material, When the layer number increases,
Laminating in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n4 are the refractive index of the material, and d1 to d4 are the thickness of the material,
First layer: 1.7 ≦ n1, 15 nm ≦ d1 ≦ 36 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 25 nm ≦ d2 ≦ 40 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 150 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 90 nm ≦ d4 ≦ 115 nm
The optical element according to claim 7, wherein: The antireflection film is characterized in that it is formed in a laminated structure consisting of five layers on the surface of the resin substrate, the first layer is the layer closest to the substrate surface, and as the distance from the substrate surface sequentially, When the layer number increases,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n5 are the refractive index of the material, and d1 to d5 are the thickness of the material. Well,
First layer: 1.2 ≦ n1 ≦ 1.55, 5 nm ≦ d1 ≦ 20 nm
Second layer: 1.7 ≦ n2, 15 nm ≦ d2 ≦ 35 nm
3rd layer: 1.2 ≦ n3 ≦ 1.55, 25 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 50 nm ≦ d4 ≦ 130 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 80 nm ≦ d5 ≦ 110 nm
The optical element according to claim 7, wherein: The antireflection film is characterized in that it is formed in a laminated structure consisting of 6 layers on the surface of the resin base material, the layer closest to the surface of the base material is the first layer, and gradually away from the surface of the base material, When the layer number increases,
Laminate in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, where n1 to n6 are the refractive indices of the materials, d1 d6 is the thickness of the material,
First layer: 1.7 ≦ n1, 8 nm ≦ d1 ≦ 15 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 35 nm ≦ d2 ≦ 55 nm
Third layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 60 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 10 nm ≦ d4 ≦ 17 nm
5th layer: 1.7 ≦ n5, 45 nm ≦ d5 ≦ 90 nm
6th layer: 1.2 ≦ n6 ≦ 1.55, 70 nm ≦ d6 ≦ 110 nm
The optical element according to claim 7, wherein: The antireflection film is characterized in that it is formed in a laminated structure consisting of 7 layers on the surface of the resin base material, the first layer is the layer closest to the surface of the base material, and sequentially away from the surface of the base material, When the layer number increases,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material. Refractive index, d1-d7 is the thickness of the material,
First layer: 1.2 ≦ n1 ≦ 1.55, 80 nm ≦ d1 ≦ 160 nm
Second layer: 1.7 ≦ n2, 10 nm ≦ d2 ≦ 25 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 33 nm ≦ d3 ≦ 45 nm
Fourth layer: 1.7 ≦ n4, 40 nm ≦ d4 ≦ 85 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 10 nm ≦ d5 ≦ 20 nm
6th layer: 1.7 ≦ n6, 6 nm ≦ d6 ≦ 70 nm
The seventh layer: 1.2 ≦ n7 ≦ 1.55, 60 nm ≦ d7 ≦ 110 nm, The optical element according to claim 7.   The low refractive index layer is made of silicon oxide or a mixture of silicon oxide and aluminum oxide, or a mixture thereof, and the high refractive index layer is made of oxide hafnium, lanthanum aluminate, zirconium oxide, oxidation The optical element according to claim 8, wherein the optical element is formed of tantalum, silicon nitride, or a mixture thereof.   In addition to the light source of wavelength λ1, the optical device includes a light source that emits light of at least one wavelength of wavelength λ2 satisfying 620 nm ≦ λ2 ≦ 670 nm and wavelength λ3 satisfying 760 nm ≦ λ3 ≦ 800 nm, The optical element according to claim 7, wherein light from the light source is transmitted through the optical element. The polymer having an alicyclic structure is an alicyclic compound represented by the following general formula (1) in a polymer repeating unit having a weight average molecular weight (Mw) of 1,000 to 1,000,000. The total content of the repeating unit (a) having a structure and the repeating unit (b) having a chain structure represented by the following general formula (2) and / or the following general formula (3) is 90% by weight or more. The optical element according to any one of claims 1 to 13, further comprising: a repeating unit (b) having a content of 1% by weight or more and less than 10% by weight.

[In Formula (1), X is an alicyclic hydrocarbon group, and in Formula (1), Formula (2), and Formula (3), R1 to R13 are each independently a hydrogen atom or a chain hydrocarbon. Group, halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group, amide group, imide group, silyl group, and polar group (halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group , An amide group, an imide group, or a silyl group). In formula (3),... Is a carbon-carbon saturated bond or an unsaturated bond. ] The polymer having an alicyclic structure includes a polymer block [A] containing a repeating unit [1] represented by the following formula (11) and a repeating unit [1] represented by the following formula (11). And a polymer block [B] containing a repeating unit [2] represented by the following formula (12) or / and a repeating unit [3] represented by the following formula (13), and the block [A A block in which the relationship between the molar fraction a (mol%) of the repeating unit [1] and the molar fraction b (mol%) of the repeating unit [1] in the block [B] is a> b. The optical element according to claim 14, wherein the optical element is a copolymer.

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ^{2 to} R ¹² each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, or 1 carbon atom. ˜20 alkoxy groups or halogen groups.)

(In the formula, R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

(In the formula, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.) A light source that emits light having a wavelength λ1 that satisfies 350 nm ≦ λ1 ≦ 450 nm, an optical element that is disposed at a position where a light beam emitted from the light source passes, and a light beam from the light source that has passed through the optical element, An optical pickup device for recording and / or reproducing information, comprising an objective lens for focusing on an information recording surface of an optical information recording medium,
The optical element is based on a resin,
The resin is a resin containing a polymer having an alicyclic structure,
An antireflection film is formed on at least one optical surface of the optical element, and the antireflection film has a low refractive index layer having a first refractive index when a light beam having the wavelength λ is passed, and the wavelength. a high refractive index layer having a second refractive index higher than the first refractive index when passing a light beam of λ,
The low refractive index layer is formed of silicon oxide, aluminum fluoride, yttrium fluoride, magnesium fluoride, a mixture of silicon oxide and aluminum oxide, or a mixture thereof, and the high refractive index layer is Scandium oxide, niobium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide, tantalum oxide, tantalum oxide and titanium mixture, silicon nitride or a mixture thereof An optical pickup device characterized by that.   The high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, praseodymium titanate, lanthanum titanate, hafnium oxide, zirconium oxide, tantalum oxide, a mixture of tantalum oxide and titanium, silicon nitride, or a mixture thereof. The optical pickup device according to claim 16, wherein   17. The optical pickup device according to claim 16, wherein the high refractive index layer is formed of scandium oxide, lanthanum oxide, lanthanum aluminate, hafnium oxide, zirconium oxide, tantalum oxide, silicon nitride, or a mixture thereof. .   The light according to claim 16, wherein the antireflection film has a two-layer structure in which the high refractive index layer and the low refractive index layer are laminated in this order on a resin base material. Pickup device.   The antireflection film has a three-layer structure in which the low refractive index layer, the high refractive index layer, and the low refractive index layer are laminated in this order on a resin base material. The optical pick-up apparatus in any one.   The antireflection film further includes a middle refractive index layer having a third refractive index higher than the first refractive index but lower than the second refractive index when the light flux having the wavelength λ is allowed to pass through, The medium refractive index layer is formed of lanthanum fluoride, neodymium fluoride, cerium fluoride, aluminum fluoride, lanthanum aluminate, lead fluoride, aluminum oxide, or a mixture thereof. The optical pick-up apparatus in any one of 16-18.   The optical pickup device according to any one of claims 16 to 18, wherein the antireflection film has a layer structure in which four or more layers are laminated on a resin base material surface. The antireflection film is characterized in that it is formed in a laminated structure consisting of four layers on the surface of the resin base material, the layer closest to the surface of the base material is the first layer, and gradually away from the surface of the base material, When the layer number increases,
Laminating in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n4 are the refractive index of the material, and d1 to d4 are the thickness of the material,
First layer: 1.7 ≦ n1, 15 nm ≦ d1 ≦ 36 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 25 nm ≦ d2 ≦ 40 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 150 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 90 nm ≦ d4 ≦ 115 nm
The optical pickup device according to claim 21, wherein The antireflection film is characterized in that it is formed in a laminated structure consisting of five layers on the surface of the resin substrate, the first layer is the layer closest to the substrate surface, and as the distance from the substrate surface sequentially, When the layer number increases,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, n1 to n5 are the refractive index of the material, and d1 to d5 are the thickness of the material. Well,
First layer: 1.2 ≦ n1 ≦ 1.55, 5 nm ≦ d1 ≦ 20 nm
Second layer: 1.7 ≦ n2, 15 nm ≦ d2 ≦ 35 nm
3rd layer: 1.2 ≦ n3 ≦ 1.55, 25 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 50 nm ≦ d4 ≦ 130 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 80 nm ≦ d5 ≦ 110 nm
The optical pickup device according to claim 21, wherein The antireflection film is characterized in that it is formed in a laminated structure consisting of 6 layers on the surface of the resin base material, the layer closest to the base material surface is the first layer, and as the distance from the surface of the base material sequentially increases , When the layer number increases,
Laminate in the order of resin base material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material, where n1 to n6 are the refractive indices of the materials, d1 d6 is the thickness of the material,
First layer: 1.7 ≦ n1, 8 nm ≦ d1 ≦ 15 nm
Second layer: 1.2 ≦ n2 ≦ 1.55, 35 nm ≦ d2 ≦ 55 nm
3rd layer: 1.7 ≦ n3, 40 nm ≦ d3 ≦ 60 nm
Fourth layer: 1.2 ≦ n4 ≦ 1.55, 10 nm ≦ d4 ≦ 17 nm
5th layer: 1.7 ≦ n5, 45 nm ≦ d5 ≦ 90 nm
Sixth layer: 1.2 ≦ n6 ≦ 1.55, 70 nm ≦ d6 ≦ 110 nm
The optical pickup device according to claim 21, wherein The antireflection film is characterized in that it is formed in a laminated structure consisting of 7 layers on the surface of the resin base material, the first layer is the layer closest to the surface of the base material, and sequentially away from the surface of the base material, When the layer number increases,
Laminate in the order of resin base material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material. Refractive index, d1-d7 is the thickness of the material,
First layer: 1.2 ≦ n1 ≦ 1.55, 80 nm ≦ d1 ≦ 160 nm
Second layer: 1.7 ≦ n2, 10 nm ≦ d2 ≦ 25 nm
Third layer: 1.2 ≦ n3 ≦ 1.55, 33 nm ≦ d3 ≦ 45 nm
Fourth layer: 1.7 ≦ n4, 40 nm ≦ d4 ≦ 85 nm
5th layer: 1.2 ≦ n5 ≦ 1.55, 10 nm ≦ d5 ≦ 20 nm
6th layer: 1.7 ≦ n6, 6 nm ≦ d6 ≦ 70 nm
Seventh layer: 1.2 ≦ n7 ≦ 1.55, 60 nm ≦ d7 ≦ 110 nm
The optical pickup device according to claim 21, wherein The low refractive index layer is formed of silicon oxide or a mixture of silicon oxide and aluminum oxide, or a mixture thereof,
The optical pickup device according to any one of claims 22 to 25, wherein the high refractive index layer is formed of hafnium oxide, lanthanum aluminate, zirconium oxide, tantalum oxide, silicon nitride, or a mixture thereof. .   In addition to the light source of wavelength λ1, the pickup device includes a light source that emits light of at least one wavelength of wavelength λ2 satisfying 620 nm ≦ λ2 ≦ 670 nm and wavelength λ3 satisfying 760 nm ≦ λ3 ≦ 800 nm, The optical pickup device according to any one of claims 16 to 27, wherein light from a plurality of light sources is transmitted through the optical element.   The optical pickup device according to any one of claims 16 to 28, wherein the optical element is an objective lens. The polymer having an alicyclic structure is an alicyclic compound represented by the following general formula (1) in a polymer repeating unit having a weight average molecular weight (Mw) of 1,000 to 1,000,000. The total content of the repeating unit (a) having a structure and the repeating unit (b) having a chain structure represented by the following general formula (2) and / or the following general formula (3) is 90% by weight or more. The optical pickup device according to any one of claims 16 to 29, further comprising: a repeating unit (b) having a content of 1 wt% or more and less than 10 wt%.

[In Formula (1), X is an alicyclic hydrocarbon group, and in Formula (1), Formula (2), and Formula (3), R1 to R13 are each independently a hydrogen atom or a chain hydrocarbon. Group, halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group, amide group, imide group, silyl group, and polar group (halogen atom, alkoxy group, hydroxy group, ether group, ester group, cyano group , An amide group, an imide group, or a silyl group). In formula (3),... Is a carbon-carbon saturated bond or an unsaturated bond. ] The polymer having an alicyclic structure includes a polymer block [A] containing a repeating unit [1] represented by the following formula (11) and a repeating unit [1] represented by the following formula (11). And a polymer block [B] containing a repeating unit [2] represented by the following formula (12) or / and a repeating unit [3] represented by the following formula (13), and the block [A A block in which the relationship between the molar fraction a (mol%) of the repeating unit [1] and the molar fraction b (mol%) of the repeating unit [1] in the block [B] is a> b. The optical pickup device according to claim 30, wherein the optical pickup device is a copolymer.

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ^{2 to} R ¹² each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, or 1 carbon atom. ˜20 alkoxy groups or halogen groups.)

(In the formula, R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

(In the formula, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

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