JP4254726B2 - Optical element for optical pickup device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a small optical element used for an optical pickup lens of an optical pickup device and a method for manufacturing the same.

  In recent years, large and small optical elements have been manufactured, ranging from large optical elements used as telescope lenses and microscope lenses to small optical elements used as optical pickup lenses such as CD (Compact Disc) and DVD (Digital Video Disc).・ It is sold. These optical elements are usually manufactured through a so-called “injection molding” process in which a specific resin according to the application is injected into a predetermined mold and molded, but the surface layer of the molded product is not a little due to residual stress. Birefringence occurs, and a light scattering phenomenon occurs in the surface layer, making it difficult to set the focal length to a desired design value.

In Patent Document 1, the molded product after cooling (standing) at room temperature is annealed at a temperature below the glass transition point, thereby relaxing the residual stress generated in the molded product and minimizing the birefringence generated in the molded product. It is described that it can be converted.
Japanese Patent No. 3055443

  However, the technique disclosed in Patent Document 1 performs annealing treatment in order to give a good performance to the molded article when molding a relatively large optical element, and specifies the conditions for the annealing treatment in detail. However, the conditions are not applicable to all resin optical elements manufactured through an injection molding process. For example, in a small optical element of a few mm scale used for the optical pickup lens or the like, if the annealing conditions are slightly different for each production lot, the difference in the conditions greatly affects the performance of forming a focused spot. . For this reason, the annealing process of the technique disclosed in Patent Document 1 cannot sufficiently relieve the residual stress or stably maintain the thermal equilibrium state during the annealing process, and is sufficient as an optical element for an optical pickup lens. Performance is not obtained.

An object of the present invention is an optical element for an optical pickup device that can be suitably used as a small optical element such as an optical pickup lens, and a method for manufacturing the same, and the residual stress is sufficiently relaxed to reduce astigmatism and the like. It is an object to provide an optical element for an optical pickup device and a method for manufacturing the same, which have dramatically improved optical characteristics.

In order to solve the above problems, the present invention
An optical element for an optical pickup device having a maximum length in the optical axis direction of 4 mm or less and a maximum length in the direction perpendicular to the optical axis direction of 6 mm or less,
After a resin containing a polymer having an alicyclic structure is injected into a mold and molded, the glass transition temperature of the resin (measured by a differential scanning calorimetry method based on JIS K7121 at a temperature rising rate of 10 ° C./min. Heat treatment or wet heat treatment for 16 hours or more at a temperature lower by 35 to 45 ° C.

  The heat treatment or wet heat treatment time is preferably 150 hours or longer.

  Further, the heat treatment or the wet heat treatment is specifically a wet heat treatment, and the relative humidity at the treatment temperature in the wet heat treatment is preferably 40 to 80%, and more preferably 55 to 65%. preferable.

In the optical element for the optical pickup device according to the present invention,
The resin is
The repeating unit (a) having an alicyclic structure represented by the following formula (1) in the polymer all repeating units having a weight average molecular weight (Mw) of 1,000 to 1,000,000, and the following formula (2) and / or the repeating unit (b) having a chain structure represented by the following formula (3) is contained so that the total content is 90% by weight or more, and further the repeating unit (b) is contained. The amount is preferably 1% by weight or more and less than 10% by weight, and the chain of the repeating unit (a) preferably contains an alicyclic hydrocarbon copolymer that satisfies the following relational formula (Z).
A ≦ 0.3 × B (Z)
(In the relational expression (Z), A = (weight average molecular weight of a chain of repeating units having an alicyclic structure), and B = (weight average molecular weight (Mw) of the alicyclic hydrocarbon copolymer) × ( The number of repeating units having an alicyclic structure / the total number of repeating units constituting the alicyclic hydrocarbon-based copolymer).

  (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, amide A chain hydrocarbon group substituted with a group, an imide group or a silyl group. In the formula (3), “...” Is a carbon-carbon saturated bond or an unsaturated bond.)

In the optical element for the optical pickup device according to the present invention,
The resin is
A polymer block [A] containing a repeating unit [1] represented by the following formula (11), a repeating unit [1] represented by the following formula (11) and a repeating represented by the following formula (12) A polymer block [B] containing a unit [2] or / and a repeating unit [3] represented by the following formula (13), and the repeating unit [1] in the polymer block [A] A block polymer in which the relationship between the molar fraction a (mol%) and the molar fraction b (mol%) of the repeating unit [1] in the polymer block [B] is a> b. preferable.

(In the formula (11), R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, the R ² -R ¹² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, a carbon (It is an alkoxy group or a halogen group of the number 1-20.)

(In the formula (12), R ¹³ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

(In formula (13), R ¹⁴ and R ¹⁵ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

The optical element for an optical pickup device according to the present invention is one of preferred embodiments that is used as an optical pickup lens of an optical pickup device.

The second aspect of the present invention
A method of manufacturing an optical element for an optical pickup device having a maximum length in the optical axis direction of 4 mm or less and a maximum length in the direction perpendicular to the optical axis direction of 6 mm or less,
A resin containing a polymer having an alicyclic structure is injected into a mold and molded, and the molded resin is subjected to glass transition temperature of the resin (temperature increase rate of 10 ° C. by differential scanning calorimetry based on JIS K7121). Heat treatment or wet heat treatment for 16 hours or more at a temperature 35 to 45 ° C. lower than the temperature measured at / min).

In the method for manufacturing an optical element for an optical pickup device according to the second aspect of the present invention, the heat treatment or wet heat treatment time is preferably 150 hours or longer.

In the method for manufacturing an optical element for an optical pickup device according to the second aspect of the present invention, the heat treatment or wet heat treatment is specifically a wet heat treatment, and the relative humidity at the treatment temperature in the wet heat treatment is 40 to 40. It is preferably 80%, more preferably 55 to 65%.

In the optical element for an optical pickup device according to the present invention, after a resin containing a polymer having an alicyclic structure is injected into a mold and molded, the glass transition temperature of the resin (differential scanning based on JIS K7121) Since heat treatment or wet heat treatment (hereinafter also referred to as “annealing” or “annealing treatment”) is performed at a temperature 35 to 45 ° C. lower than the temperature measured at a heating rate of 10 ° C./min by a calorimetric analysis method) for 16 hours or more. Residual stress is sufficiently relaxed, and optical characteristics such as astigmatism are drastically improved.

In the method for manufacturing an optical element for an optical pickup device according to the second aspect of the present invention, a resin containing a polymer having an alicyclic structure is injected into a mold and molded, and the molded resin is made of the resin glass. Residual stress is sufficiently relaxed because heat treatment or wet heat treatment is performed for 16 hours or more at a temperature 35 to 45 ° C. lower than the transition temperature (temperature measured at a rate of temperature increase of 10 ° C./min by differential scanning calorimetry based on JIS K7121). Thus, it is possible to manufacture an optical element in which optical characteristics such as astigmatism are drastically improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

FIG. 1 is a cross-sectional view showing a schematic configuration of the optical pickup device 1.
As shown in FIG. 1, the optical pickup device 1 has a light source unit 2. The light source unit 2 has a box-shaped housing 3 whose upper part in FIG. 1 is formed of a light-transmitting substrate. Inside the housing 3, a CD light source 4 that emits light (laser) with a specific wavelength for CD and a DVD light source 5 that emits light (laser) with a specific wavelength for DVD are arranged. Yes. The light emitted from the CD light source 4 passes through the light-transmitting substrate of the housing 3 as a light beam indicated by a dotted line in FIG. 1 and propagates in the transmission direction as it is, and is emitted from the DVD light source 5. Is transmitted through the light-transmitting substrate of the housing 3 as it is as a light beam indicated by a solid line in FIG.

  In the optical axis direction of each light emitted from the light source 4 for CD and the light source 5 for DVD, the collimator 11, the splitter 12, the quarter wavelength plate 13, the diaphragm member 14, and the optical pickup from the lower side to the upper side in FIG. The lenses 15 are arranged in order, and a CD 20 or a DVD 30 as an information recording medium is arranged at a position facing the optical pickup lens 15. A cylindrical lens 16, a concave lens 17, and a sensor 18 are arranged in this order from the left side to the right side in FIG.

  An optical pickup lens 15 used as an optical element according to the present invention is an aspheric objective lens for an optical disk, and is disposed at a position facing a CD 20 or a DVD 30 as an information recording medium. The optical pickup lens 15 is arranged so as to be movable in the vertical direction in FIG. 1. When the information on the CD 20 is read, the optical pickup lens 15 is disposed at the position indicated by the dotted line in FIG. It is arranged at the position indicated by the solid line.

  The operation and action of the optical pickup device 1 will be briefly described. When reading information on the CD 20, the optical pickup lens 15 is disposed at the position indicated by the dotted line in FIG. Is emitted. The light emitted from the CD light source 4 first passes through the collimator 12 to become a parallel light beam, then passes through the splitter 12 and the quarter-wave plate 13, is narrowed down by the diaphragm member 14, and is transmitted through the optical pickup lens 15. Thus, a focused spot is formed on the recording surface of the CD 20.

  The light that forms the condensed spot is modulated by the information pits on the recording surface of the CD 20 and reflected by the recording surface, and the reflected light passes through the optical pickup lens 15, the diaphragm member 14, and the quarter wavelength plate 13. The light is branched by the splitter 12, passes through the cylindrical lens 16 and the concave lens 17, and is received by the sensor 18. Thereby, the information recorded on the CD 20 is read.

  On the other hand, when reading information on the DVD 30, the optical pickup lens 15 is disposed at a position indicated by a solid line in FIG. 1, and the light source 5 for DVD emits light in this state, and thereafter, information on the CD 20 is read. Information recorded on the DVD 30 is read by the same operation and action as the case.

FIG. 2 is a drawing showing a schematic configuration of the optical pickup lens 15, FIG. 2A is a perspective view of the optical pickup lens 15, and FIG. 2B is a cross-sectional view of the optical pickup lens 15.
As shown in FIGS. 2A and 2B, the optical pickup lens 15 has a dome-shaped lens portion 15a and a ring-shaped flange portion 15b that supports the periphery of the lens portion 15a. The flange portion 15b is integrally formed. The optical pickup lens 15 has a maximum length D in the optical axis direction (here, the maximum thickness of the lens portion 15a) of 4 mm or less, and a maximum length L in the direction perpendicular to the optical axis direction (here, the flange portion 15b). The maximum length connecting the end portions) is 6 mm or less.

  The optical pickup lens 15 is composed of a resin containing a polymer having an alicyclic structure. Specifically, the resin is injected into the mold and cooled and molded at room temperature. It has been heat-treated or wet-heated for 16 hours or more at a temperature 35 to 45 ° C. lower than the glass transition temperature of the resin (temperature measured at a rate of temperature increase of 10 ° C./min by differential scanning calorimetry based on JIS K7121). .

  Here, the “resin containing a polymer having an alicyclic structure” constituting the optical pickup lens 15 will be described in detail.

The “resin containing a polymer having an alicyclic structure” is represented by the following formula (1) in all repeating units of a polymer having a weight average molecular weight (Mw) of 1,000 to 1,000,000. The total content of the repeating unit (a) having an alicyclic structure and the repeating unit (b) having a chain structure represented by the following formula (2) and / or the following formula (3) is 90% by weight. The alicyclic hydrocarbon is contained so that the content of the repeating unit (b) is 1% by weight or more and less than 10% by weight and the chain of the repeating unit (a) satisfies the following relational formula (Z): It is preferable to contain a system copolymer.
A ≦ 0.3 × B (Z)
In relational formula (Z), A = (weight average molecular weight of a chain of repeating units having an alicyclic structure), and B = (weight average molecular weight (Mw) of alicyclic hydrocarbon-based copolymer × (aliphatic). The number of repeating units having a cyclic structure / the total number of repeating units constituting the alicyclic hydrocarbon-based copolymer).

  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 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, and more preferably 5 to 7. . 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 addition, “...” In the formula (3) represents carbon-carbon saturation or carbon-carbon unsaturated bond in the main chain, but unsaturated bond is required when transparency and heat resistance are strongly required. The content of is usually 10% or less, preferably 5% or less, more preferably 3% or less, of all the carbon-carbon bonds constituting the main chain.

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

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

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

  In formula (4), formula (5) and formula (6), Ra, Rb, Rc, Rd, Re, Rf, Rg, Rh, Ri, Rj, Rk, Rl, Rm and Rn are each independently a hydrogen atom. Alternatively, it represents a lower chain hydrocarbon group, 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 having a chain structure represented by the formulas (2) and (3), the repeating unit having a chain structure represented by the formula (3) is stronger in the obtained hydrocarbon polymer. Excellent characteristics.

  In the present invention, a repeating unit (a) having an alicyclic structure represented by the formula (1) and a chain represented by the formula (2) and / or the formula (3) in the hydrocarbon copolymer. The total content with the repeating unit (b) of the shape structure 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 alicyclic hydrocarbon copolymer is appropriately selected according to the purpose of use, but is usually 1% or more and less than 10%, preferably 1% on a weight basis. It 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 alicyclic hydrocarbon copolymer, specifically, A = (repeating unit chain having an alicyclic structure). Weight average molecular weight), B = (Weight average molecular weight of alicyclic hydrocarbon copolymer (Mw) × (number of repeating units having alicyclic structure / all repeats constituting alicyclic hydrocarbon copolymer) 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 alicyclic hydrocarbon copolymer of the present invention is 1,000 in terms of polystyrene (or polyisoprene) converted weight average molecular weight (Mw) measured by gel permeation chromatography (hereinafter, GPC). In the range of ˜1,000,000, preferably 5,000 to 500,000, more preferably 10,000 to 300,000, and most preferably 50,000 to 250,000. If the weight average molecular weight (Mw) of the alicyclic hydrocarbon copolymer is excessively small, the strength characteristics of the molded product are inferior. Conversely, if the molecular weight 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 depending on the purpose of use, but is usually 50 to 250 ° C, preferably 70 to 200 ° C, more preferably 90 to 180 ° C.

  Next, a method for producing the “polymer having an alicyclic structure” will be described.

  The method for producing an alicyclic hydrocarbon-based copolymer is as follows: (1) copolymerizing an aromatic vinyl compound with another monomer that can be copolymerized, and hydrogenating the carbon-carbon unsaturated bonds 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 alicyclic hydrocarbon-based copolymer of the present invention is produced by the above-described method, the aromatic vinyl compound and / or other monomer copolymerizable with the alicyclic vinyl compound (a ′) ( b ′), the repeating unit derived from the compound (a ′) in the copolymer is D = (weight of the repeating unit chain derived from the aromatic vinyl compound and / or the alicyclic vinyl compound) Average 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) Of the copolymer having a chain structure in which D is 30% or less of E, preferably 20% or less, more preferably 15% or less, and most preferably 10% or less. Main chain, aromatic ring and cycloalkene ring Carbon of the unsaturated ring - can be obtained efficiently by a method for hydrogenating carbon-carbon unsaturated bond. When D is out of the above range, the low birefringence of the resulting alicyclic hydrocarbon copolymer is poor.

  In the present invention, the method (1) is preferable because an alicyclic hydrocarbon copolymer 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 alicyclic hydrocarbon copolymer is poor.

  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 alicyclic hydrocarbon copolymer obtained therefrom are inferior. Conversely, 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 resulting alicyclic hydrocarbon copolymer 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 to 200 ° C, preferably 20 to 150 ° C. In the case where it is necessary to prevent the contamination of impurities, etc., bulk polymerization and suspension polymerization are desirable. 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, a method such as bulk polymerization, solution polymerization, slurry polymerization is usually performed in the temperature range of 0 to 200 ° C., preferably 20 to 100 ° C., particularly preferably 20 to 80 ° C. in the presence of an initiator. Although it can be used, solution polymerization is preferred 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.

(Method of hydrogenating unsaturated bonds)
When conducting hydrogenation reactions such as carbon-carbon double bonds of unsaturated rings such as aromatic rings and cycloalkene rings of the copolymer before hydrogenation, and unsaturated bonds of the main chain, the reaction method and reaction form are special. There is no particular limitation, and it may be carried out according to a known method, but 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, for example, in an organic solvent, nickel, The method is performed using a catalyst containing at least one metal selected from cobalt, iron, 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 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 to 250 ° C., but preferably 50 to 200 ° C., more preferably, because the hydrogenation rate can be increased and the polymer chain scission reaction occurring simultaneously with the hydrogenation reaction can be reduced. Is 80-180 ° C. 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 way is determined by ¹ H-NMR, as determined by carbon-carbon unsaturated bond of the main chain, carbon-carbon double bond of aromatic ring, carbon of unsaturated ring All of the carbon 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.

  The “resin containing a polymer having an alicyclic structure” may contain an antioxidant.

  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. 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 copolymer.

  The “resin containing a polymer having an alicyclic structure” includes the alicyclic hydrocarbon-based copolymer, (1) a soft polymer, (2) an alcoholic compound, and (3) an organic compound. Alternatively, at least one kind of compounding agent selected from the group consisting of inorganic fillers may be contained. 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 Copolymer, diene-based soft polymer such as isoprene / styrene / block copolymer, styrene / isoprene / styrene / block copolymer;

  Silicon-containing soft polymers such as dimethylpolysiloxane, diphenylpolysiloxane, dihydroxypolysiloxane; α, such as polybutyl acrylate, polybutyl methacrylate, polyhydroxyethyl methacrylate, polyacrylamide, polyacrylonitrile, butyl acrylate / styrene copolymer Soft polymer made of β-unsaturated acid; soft polymer made of unsaturated alcohol such as polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, vinyl acetate / styrene copolymer and amine or acyl derivative or acetal thereof; Epoxy soft polymers such as ethylene oxide, polypropylene oxide and epichlorohydrin rubber; Fluorine such as vinylidene fluoride rubber and tetrafluoroethylene-propylene rubber And other soft polymers such as natural rubber, polypeptide, protein, polyester thermoplastic elastomer, vinyl chloride thermoplastic elastomer, polyamide thermoplastic elastomer, and the like. 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, and 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 It can be mentioned.

  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 compounds (1) to (3) is determined depending on the combination of the compound blended with the alicyclic hydrocarbon copolymer, but generally, if the compounding amount is too large, the glass transition temperature of the composition or Transparency is 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 alicyclic hydrocarbon-based copolymer. It mixes in the ratio. 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.

  In addition, in the above-mentioned “resin containing a polymer having an alicyclic structure”, as required, other compounding agents such as ultraviolet absorbers, light stabilizers, near-infrared absorbers, dyes and pigments are colored. Agents, lubricants, plasticizers, antistatic agents, fluorescent whitening agents, and the like can be blended, and these can be used alone or in admixture of two or more. The blending amount impairs the object of the present invention. It is appropriately selected within a range that does not exist.

  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 Mn in terms of polystyrene measured by GPC using THF as a solvent are preferably 1000 to 10,000, and more preferably 2000 to 5000. Particularly preferred is 2800-3800. If Mn is too small, when HALS is blended by heat-melting and kneading into the block copolymer, a predetermined amount cannot be blended due to volatilization, foaming or silver streaks occur 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.

  Moreover, the composition of the above-mentioned “resin containing a polymer having an alicyclic structure” 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.

  More specifically, the “resin containing a polymer having an alicyclic structure” includes a polymer block [A] containing a repeating unit [1] represented by the following formula (11) and the following formula (11). A polymer block [B] containing a repeating unit [1] represented by the following formula (12) and / or a repeating unit [3] represented by the following formula (13): And a mole fraction a (mol%) of the repeating unit [1] in the polymer block [A] and a mole fraction b (mol) of the repeating unit [1] in the polymer block [B]. %) Is preferable to contain a block polymer in which a> b.

In Formula (11), R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ^{2 to} R ¹² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, or a carbon number. 1 to 20 alkoxy groups or halogen groups.

In Formula (12), R ¹³ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

In Formula (13), R ¹⁴ and R ¹⁵ are each independently 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 [2] represented by the following formula (12) or / and the repeating unit [3] represented by the following 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 preferable. 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 [2] represented by the above formula (12) is one in which R ¹³ is hydrogen or a methyl group.

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.

In the formula (X), 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 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.

  Further, 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 referred to as “Mw”), preferably in the range of 10,000 to 300,000, more preferably 15,000 to 250,000, 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 depending on the purpose of use, but is the ratio of Mw in terms of polystyrene (or polyisoprene) measured by GPC and the number average molecular weight (hereinafter referred to as “Mn”) ( Mw / 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 according to the purpose of use, but it is determined on the high temperature side by a differential scanning calorimeter (hereinafter referred to as “DSC”). The measured value is preferably 70 to 200 ° C, more preferably 80 to 180 ° C, and particularly preferably 90 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, a monomer mixture containing an aromatic vinyl compound or / and 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). A polymer block containing a repeating unit derived from an aromatic vinyl compound or / and an alicyclic vinyl compound, and a polymer block containing a repeating unit derived from a vinyl monomer A block 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 polymer block containing a repeating unit derived from an alicyclic vinyl compound, and a block copolymer having a polymer block containing a repeating unit derived from a vinyl monomer. Examples include a method for obtaining a coalescence. 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. Monomer mixture of vinyl monomer (excluding aromatic vinyl compound and alicyclic vinyl compound) of 2 mol% or more, and aromatic vinyl compound and / or alicyclic vinyl compound having an unsaturated bond in the ring The monomer mixture [b ′], which is contained in an amount smaller than the proportion in [a ′], is polymerized to repeat the aromatic vinyl compound or / and the alicyclic vinyl compound-derived repeating unit and the vinyl monomer. A polymer block [B ′] containing repeating 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 carried out in the presence of a polymerization initiator in the temperature range of usually 0 to 200 ° C, preferably 20 to 100 ° C, particularly preferably 20 to 80 ° C. 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 dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol diethyl ether, ethylene glycol methyl phenyl ether, and other ether compounds; tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, and the like. 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 the polymer block [A ′] and the polymer block [B ′] obtained in the method (1) (hereinafter referred to as “pre-hydrogenation block copolymer”), the following structure is provided. Those having a repeating unit of

  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).

In the formula (14), 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, It is a C1-C20 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 ′.

In the formula (15), R ²² represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

In Formula (16), 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).

In the formula (Y), 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 Represents a hydrogen atom. Alternatively, 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 according to the purpose of use, but it is 70 to 150 ° C., more preferably 80 to 140 ° C., particularly preferably as measured on the high temperature side by DSC. Is 90-130 ° C.

  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 to 250 ° C., but preferably 50 to 200 ° C., more preferably 80 to 180 ° C., because the hydrogenation rate can be increased and the polymer chain scission reaction can be reduced. is there. 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 obtained in this way is determined by ¹ H-NMR as measured by carbon-carbon unsaturated bonds of the main chain and side chains, carbon-carbon unsaturation of aromatic rings and cycloalkene rings. Any of the saturated 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.

  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 the transparency of the block copolymer are greatly lowered 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 be used as the material of the optical pickup lens 15.

  Next, a method for manufacturing the optical pickup lens 15 will be described.

  First, the above-described “resin containing a polymer having an alicyclic structure” is injected and filled into a mold heated to a predetermined temperature, and the filled resin is allowed to stand and cool in the mold. Solidify. After standing for a predetermined time, the solidified resin (molded product) is taken out from the mold, and the molded product is allowed to cool at room temperature. When a predetermined time has passed in this state, the molded product is transferred to a thermostatic bath, and the glass transition temperature of the resin constituting the molded product (measured at a rate of temperature increase of 10 ° C./min by differential scanning calorimetry based on JIS K7121). The molded product is heat-treated or wet-heated for 16 hours or more at a temperature lower by 35 to 45 ° C. Thereby, the optical pickup lens 15 in which the residual stress is sufficiently relaxed and the optical characteristics such as astigmatism are drastically improved can be manufactured.

  In the above embodiment, the optical pickup lens 15 has a glass transition temperature of the resin that forms the molded product after injection molding (temperature increase rate of 10 ° C./min by differential scanning calorimetry based on JIS K7121). Since the heat treatment or wet heat treatment is performed at a temperature 35 to 45 ° C. lower than the temperature measured in step 3), the residual stress is sufficiently relaxed, and optical characteristics such as astigmatism and spherical aberration are drastically improved. Birefringence generated in the surface layer of the optical pickup lens 15 is also greatly reduced.

The present invention is not limited to the above embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, in the above embodiment, the optical element and the manufacturing method thereof according to the present invention are applied to the optical pickup lens 15. However, the optical element and the manufacturing method according to the present invention constitute the optical pickup lens device 1. May be applied to the collimator 11, the separator 12, the quarter wavelength plate 13, the cylindrical lens 16, the concave lens 17, or the like, or may be applied to an optical element used for purposes other than the optical pickup lens device 1, Eventually, it is applicable to all small optical molded products having a maximum length in the optical axis direction of 4 mm or less and a maximum length in the direction perpendicular to the optical axis direction of 6 mm or less.

  In this example, a plurality of types of samples (optical pickup lenses) were produced, the outer shape of each of the produced samples was observed, and spherical aberration and astigmatism were further measured.

(1) Preparation of Sample As “resin containing a polymer having an alicyclic structure” described in the above embodiment, ZEONEX 340R (glass transition temperature 122 ° C .; differential scanning calorimetry (DSC) of JIS K7121 ), The resin was injected and molded with a predetermined mold, and the molded product was allowed to stand at room temperature and cooled to obtain a CD / DVD compatible optical pickup. A plurality of types of molded products were obtained assuming a lens. Each of the molded products had a diffractive structure on the entire optical functional surface, and the numerical aperture (NA) of CD was 0.45 and the numerical aperture (NA) of DVD was 0.65. As shown in FIG. 2, each molded product has a lens portion and a flange portion surrounding the lens portion, and the maximum length in the optical axis direction (maximum thickness of the lens portion) is 2.00 mm. The maximum length in the direction perpendicular to the optical axis direction (the maximum length connecting the ends of the flange portion) was 5.00 mm.

  With respect to these plural types of molded products, heat treatment or wet heat treatment was performed under the conditions shown in Table 1 below using an oven or a thermo-hygrostat, and "Samples 1 to 12, 21 to 26" were produced.

(2) Observation of external shape About each sample 1-12, 21-26, the difference with the target shape at the time of design was observed visually with the microscope. The observation results of Samples 1 to 12 and 21 to 26 are shown in Table 1 below. As shown in Table 1, the outer diameter shapes of the samples 1, 3 to 12, 21 to 26 other than the sample 2 were as designed, but the sample 2 was greatly deformed.

(3) Measurement of spherical aberration and astigmatism For each of samples 1 to 12, 21 to 26, spherical aberration and astigmatism are measured with an interferometer (use wavelength is 650 nm) that can be numerically analyzed using a known method. Was measured. The measurement results of Samples 1 to 12 and 21 to 26 are shown in Table 1 below. As shown in Table 1, the heat treatment or wet heat treatment temperature was obtained by subtracting 35 ° C. from the glass transition temperature (122 ° C.) of each of the samples 1 to 12 and 21 to 26 (122 ° C.−35 ° C. = 87 in this example). When the temperature was higher than (° C.), the deformation was so great that the aberration could not be measured (see Sample 22).

  Further, the heat treatment or wet heat treatment temperature is lower than the temperature obtained by subtracting 45 ° C. from the glass transition temperatures (122 ° C.) of the samples 1 to 12 and 21 to 26 (122 ° C.−45 ° C. = 77 ° C. in this embodiment). In the case where heat treatment or wet heat treatment was not performed, a large value that could not withstand actual use was obtained because the residual stress in the sample was not sufficiently relaxed (samples 23 and 24). , 26).

In Table 1, each aberration measurement result of “spherical aberration, astigmatism” is evaluated according to the following criteria.
0.02 or more: Unbearable in actual use 0.01 or more and less than 0.02: Useable but unfavorable level 0.005 or more and less than 0.01: Usable Less than 0.005: Sufficient Can be used and is at a preferred level

  As shown in Table 1, even when the heat treatment or wet heat treatment temperature is in the range of 35 to 45 ° C. lower than the glass transition temperature (122 ° C.) of the resin constituting each sample 1 to 12, 21 to 26, When the treatment time was less than 16 hours, sufficient stress relaxation could not be obtained, and the aberration level was actually unusable (see Samples 21 and 25). Further, it was found that when the heat treatment or the wet heat treatment was performed for 150 hours or more, a more preferable aberration level was obtained from the sample used for the treatment (see Samples 1, 2, 4, and 5).

  Moreover, the processing temperature of heat processing or wet heat processing is in the range of 35-45 degreeC lower than the glass transition temperature (122 degreeC) of resin which comprises each sample 1-12, 21-26, and the processing time is 16 times. If it is longer than the time, there is no practical problem with the level of aberration under any humidity condition. However, in the heat treatment or wet heat treatment, the relative humidity at the treatment temperature is preferably 40 to 80% in terms of lens performance (see Samples 6 to 9), and particularly preferred when the relative humidity is 55 to 65%. A result was obtained (see Sample 1).

  From the above, the molded product after injection / molding is 35 to 35 from the glass transition temperature of the resin constituting it (glass transition temperature measured at a heating rate of 10 ° C./min by differential scanning calorimetry based on JIS K7121). It has been found that heat treatment or wet heat treatment at a temperature of 45 ° C. for 16 hours or longer, preferably 150 hours or longer is useful for sufficiently relaxing residual stress in a small optical element. It has been found that it is more useful to set the relative humidity at the treatment temperature to 40 to 80%, more preferably 55 to 65%.

It is sectional drawing which shows schematic structure of an optical pick-up apparatus. It is (a) perspective view (b) sectional drawing which shows schematic structure of an optical pick-up lens.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up apparatus 2 Light source unit 3 Case 4 CD light source 5 DVD light source 11 Collimator 12 Splitter 13 1/4 wavelength plate 14 Diaphragm member 15 Optical pick-up lens 15a Lens part 15b Flange part 16 Cylindrical lens 17 Concave lens 18 Sensor 20 CD
30 DVD

Claims (11)

An optical element for an optical pickup device having a maximum length in the optical axis direction of 4 mm or less and a maximum length in the direction perpendicular to the optical axis direction of 6 mm or less,
After a resin containing a polymer having an alicyclic structure is injected into a mold and molded, the glass transition temperature of the resin (measured by a differential scanning calorimetry method based on JIS K7121 at a temperature rising rate of 10 ° C./min. An optical element for an optical pickup device, which is heat-treated or wet-heated for 16 hours or more at a temperature lower by 35 to 45 ° C. The optical element for an optical pickup device according to claim 1,
An optical element for an optical pickup device, wherein the heat treatment or wet heat treatment time is 150 hours or more. The optical element for an optical pickup device according to claim 1 or 2,
The heat treatment or wet heat treatment is a wet heat treatment,
An optical element for an optical pickup device, wherein the relative humidity at the treatment temperature in the wet heat treatment is 40 to 80%. The optical element for an optical pickup device according to claim 3,
An optical element for an optical pickup device, wherein the relative humidity is 55 to 65%. In the optical element for optical pickup devices according to any one of claims 1 to 4,
The resin is
The repeating unit (a) having an alicyclic structure represented by the following formula (1) in the polymer all repeating units having a weight average molecular weight (Mw) of 1,000 to 1,000,000, and the following formula (2) and / or the repeating unit (b) having a chain structure represented by the following formula (3) is contained so that the total content is 90% by weight or more, and further the repeating unit (b) is contained. For an optical pickup device, comprising an alicyclic hydrocarbon-based copolymer having an amount of 1% by weight or more and less than 10% by weight, wherein the chain of repeating units (a) satisfies the following relational formula (Z): optical element of.
A ≦ 0.3 × B (Z)
(In the relational expression (Z), A = (weight average molecular weight of a chain of repeating units having an alicyclic structure), and B = (weight average molecular weight (Mw) of the alicyclic hydrocarbon copolymer) × ( The number of repeating units having an alicyclic structure / the total number of repeating units constituting the alicyclic hydrocarbon-based copolymer).

(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, amide A chain hydrocarbon group substituted with a group, an imide group or a silyl group. In the formula (3), “...” Is a carbon-carbon saturated bond or an unsaturated bond.) The optical element for an optical pickup device according to claim 5,
The resin is
A polymer block [A] containing a repeating unit [1] represented by the following formula (11), a repeating unit [1] represented by the following formula (11) and a repeating represented by the following formula (12) A polymer block [B] containing a unit [2] or / and a repeating unit [3] represented by the following formula (13), and the repeating unit [1] in the polymer block [A] A block polymer in which the relationship between the molar fraction a (mol%) and the molar fraction b (mol%) of the repeating unit [1] in the polymer block [B] is a> b. An optical element for an optical pickup device .

(In the formula (11), R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, the R ² -R ¹² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a hydroxyl group, a carbon (It is an alkoxy group or a halogen group of the number 1-20.)

(In the formula (12), R ¹³ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

(In formula (13), R ¹⁴ and R ¹⁵ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.) In the optical element for the optical pickup device according to any one of claims 1 to 6,
An optical element for an optical pickup device, which is used as an optical pickup lens of an optical pickup device . A method of manufacturing an optical element for an optical pickup device having a maximum length in the optical axis direction of 4 mm or less and a maximum length in the direction perpendicular to the optical axis direction of 6 mm or less,
A resin containing a polymer having an alicyclic structure is injected into a mold and molded, and the molded resin is subjected to glass transition temperature of the resin (temperature increase rate of 10 ° C. by differential scanning calorimetry based on JIS K7121). A method for producing an optical element for an optical pickup device, comprising heat treatment or wet heat treatment for 16 hours or more at a temperature 35 to 45 ° C. lower than the temperature measured at / min). In the manufacturing method of the optical element for optical pickup devices according to claim 8,
A method for producing an optical element for an optical pickup device, wherein the heat treatment or wet heat treatment time is 150 hours or longer. In the manufacturing method of the optical element for optical pickup devices according to claim 8 or 9,
The heat treatment or wet heat treatment is a wet heat treatment,
A method for producing an optical element for an optical pickup device, wherein the relative humidity at the treatment temperature in the wet heat treatment is 40 to 80%. In the manufacturing method of the optical element for optical pickup devices according to claim 10,
The method of manufacturing an optical element for an optical pickup device, wherein the relative humidity is 55 to 65%.

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