WO2006054462A1

WO2006054462A1 - Optical device and optical pickup device

Info

Publication number: WO2006054462A1
Application number: PCT/JP2005/020504
Authority: WO
Inventors: Yasumitsu Fujino
Original assignee: Konica Minolta Opto, Inc.
Priority date: 2004-11-22
Filing date: 2005-11-09
Publication date: 2006-05-26
Also published as: JPWO2006054462A1

Abstract

Disclosed is an optical device which is molded by using an alicyclic hydrocarbon copolymer containing a repeating unit (a) having an alicyclic structure represented by the formula (1), a repeating unit (b) having a chain structure represented by the formula (2) and/or formula (3) and/or formula (4), and a chain unit (c) carrying a hindered amine structure represented by the formula (5) in the side chain, in which copolymer the total content of the repeating unit (a) and the repeating unit (b) is not less than 90% by weight and the content of the repeating unit (b) is not less than 1% by weight and less than 10% by weight; or a resin composition containing such an alicyclic hydrocarbon copolymer.

Description

Specification

Optical element and optical pickup device

Technical field

The present invention relates to a plastic optical element and an optical pickup device to which the optical element is applied.

Background art

[0002] Conventionally, optical pickup has been performed for information devices such as players, recorders, and drives that read and record information on M0, CD, DVD, and other optical information recording media (hereinafter abbreviated as media). A device is provided. The optical pickup device includes an optical element unit that irradiates a medium with light having a predetermined wavelength emitted from a light source, and receives the reflected light with a light receiving element. The optical element unit transmits the light to a reflection layer of the medium. It has an optical element such as a lens for condensing light by the light receiving element.

[0003] The optical element of the optical pickup device is preferably made of plastic as a material because it can be manufactured at low cost by means such as injection molding. As plastics applicable to optical elements, alicyclic hydrocarbon copolymers and the like are known (see, for example, Patent Document 1).

[0004] By the way, in recent years, as a medium capable of recording information at a higher density than CD and DVD, information is recorded and reproduced at a shorter wavelength than that of CD (λ = 780nm) and DVD (= 635 and 650nm). Development of media such as Blu_ray Disc and information devices that read and write information on these media is newly underway.

Patent Document 1: Japanese Patent Laid-Open No. 2001-48924

Disclosure of the invention

Problems to be solved by the invention

[0005] However, in so-called next-generation DVDs such as Blu_ray Discs, the power to use light with a wavelength of around 400 nm for recording and reproduction of information S, and in the case of Patent Document 1, the optical element emits light with such short wavelengths. If the optical element itself becomes cloudy or the refractive index fluctuates, the product life will be shortened. There was a match.

[0006] Therefore, an object of the present invention is to provide an optical element capable of improving light stability and maintaining its characteristics over a long period of time, and an optical pickup apparatus having good pickup characteristics using the optical element. Is to provide.

Means for solving the problem

[0007] In order to solve the above problem, the optical element of the invention according to Item 1,

The repeating unit (a) having an alicyclic structure represented by the following formula (1), and a chain structure represented by the following formula (2) and / or the following formula (3) and / or the following formula (4) And a chain unit (c) having a hindered amine structure represented by the following formula (5) in the side chain,

The total content of the repeating unit (a) and the repeating unit (b) is 90% by weight or more, and the content of the repeating unit (b) is 1% by weight or more and less than 10% by weight. It is characterized by being molded using a hydrocarbon copolymer or a resin composition containing the alicyclic hydrocarbon copolymer.

[0008] [Chemical 1]

... (Formula 1)

[0009] [Chemical 2]

■ ■ ■ (Formula 2)

[0010] [Chemical 3]

[0011] [Chemical 4]

(Formula 4)

[0012] [Chemical 5]

… Pa 5)

[In Formula (1), X is an alicyclic hydrocarbon group, and in Formula (1), Formula (2), Formula (3), and Formula (4), R1 to R13 are each independently Hydrogen atom, 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 group, imide group, or silyl group), and in formula (5), R14 to R19 each independently represents a hydrogen atom or an alkyl group. Y represents an alkylene group having from 10 to 10 carbon atoms or an ester bond. ]

The invention according to Item 2 is the optical element according to Item 1,

The alicyclic hydrocarbon copolymer includes at least one stabilizer selected from a phenol stabilizer, a hindered amine stabilizer, a phosphorus stabilizer, and a thio stabilizer. It is characterized by being contained.

[0014] The invention according to Item 3 is the optical element according to Item 1 or 2,

Melt index (Ml) value of the alicyclic hydrocarbon copolymer or the resin composition measured under the conditions of a temperature of 260 ° C and a load of 2.16 kg 20 Ml (g / 10 min) 60 In range,

It is characterized in that a predetermined fine structure is provided on at least one optical surface.

[0015] The invention according to item 4,

An optical pickup device for reproducing and / or recording information on an optical information recording medium,

A light source that emits light;

An optical element unit that irradiates the optical information recording medium with light emitted from the light source and collects light reflected by Z or the optical information recording medium;

The optical element unit is

The repeating unit (a) having an alicyclic structure represented by the following formula (1), and a chain structure represented by the following formula (2) and / or the following formula (3) and / or the following formula (4) The repeating unit (b) and a chain unit (c) having a hindered amine structure represented by the following formula (5) in the side chain, the repeating unit (a) and the repeating unit (b) The alicyclic hydrocarbon copolymer or the alicyclic hydrocarbon having a total content of 90% by weight or more and a content of the repeating unit (b) of 1% by weight or more and less than 10% by weight An optical element formed by using a resin composition containing a copolymer is provided.

[0016] [Chemical 6]

(Equation 1)

1

[0017] [Chemical 7] (Formula 2)

[0018] [Chemical 8]

(Formula 3)

[0019] [Chemical 9]

(Formula 4)

[0020] [Chemical 10]

ぱ 5)

[In Formula (1), X is an alicyclic hydrocarbon group, and in Formula (1), Formula (2), Formula (3), and Formula (4), R1 to R13 are each independently a hydrogen atom, 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, A chain hydrocarbon group substituted with a cyano group, an amide group, an imide group, or a silyl group), which has the formula (

In 5), R14 to R19 each independently represents a hydrogen atom or an alkyl group, and Y represents the number of carbon atoms.

: Represents an alkylene group of 10 to 10 or an ester bond. ]

The invention according to Item 5 is the optical pickup device according to Item 4,

The light source emits light having a wavelength of 390 to 420 [nm]. The invention's effect

[0022] According to the invention of Item 1, an alicyclic hydrocarbon copolymer in which a chain unit having a hindered amine structure in a side chain is directly bonded to a polymer molecular chain, or the alicyclic hydrocarbon copolymer. Since it is molded using a resin composition containing coalescence, bleeding out of the hindered amine moiety having a light stabilizing function is suppressed, and the hindered amine is uniformly dispersed in the resin composition. Even with continuous irradiation of light having a short wavelength such as 405 nm, it is possible to effectively suppress deterioration of the optical element such as white turbidity and refractive index fluctuation. That is, the optical stability of the optical element can be improved, and the characteristics can be maintained for a long time.

[0023] According to the invention described in Item 2, various stabilizers are appropriately selected from a phenol stabilizer, a hindered amine stabilizer, a phosphorus stabilizer, and a thio stabilizer, and an alicyclic hydrocarbon. By adding to a resin composition containing a copolymer or an alicyclic hydrocarbon copolymer, fluctuations in the optical properties of the molded optical element can be suppressed more synergistically.

[0024] According to the invention described in item 3, it is obvious that the same effect as the invention described in item 1 or 2 can be obtained, in particular, measured at a temperature of 260 ° C and a load of 2.16 kg. The alicyclic hydrocarbon copolymer or resin composition has a melt index (Ml) value of 20 to Ml (g / 10 min) to 60, and a predetermined microstructure is provided on at least one optical surface. ing. That is, since the melt index is in a range suitable for a molding method such as injection molding, the molten alicyclic hydrocarbon copolymer or resin composition has appropriate fluidity. When molding an optical element, the molten alicyclic hydrocarbon copolymer or resin composition reaches the tip of the part corresponding to the microstructure, and thus the optical element thus formed has high accuracy. The fine structure formed by is provided.

[0025] According to the invention of Item 4, the optical element is a chain having a hindered amine structure in the side chain. Since it is molded using an alicyclic hydrocarbon copolymer in which structural units are directly bonded in the polymer molecular chain, or a resin composition containing the alicyclic hydrocarbon copolymer, it has a light stabilizing function. Bleeding out of the hindered amine site is suppressed, and the hindered amin is uniformly dispersed in the resin composition, so that even if it is continuously irradiated with light having a short wavelength such as 405 nm, the optical element Degradation such as white turbidity and refractive index fluctuation can be effectively suppressed. That is, the optical stability of the optical element can be improved, and the characteristics can be maintained for a long time.

Therefore, for example, information can be read and written with good pickup characteristics over a long period of time on an optical information recording medium having a high information density such as a Blu-ray Disc, and the optical pickup device is reliable. Can be obtained.

[0027] According to the invention described in Item 5, the wavelength of the light emitted from the light source is 390 to 420 [nm]. That is, for example, even when light of a wavelength in the range of 390 to 420 [nm] corresponding to an optical information recording medium having a high information density such as a Blu-ray Disc is transmitted, the optical element has a hindered amine structure as a side chain. Are formed using an alicyclic hydrocarbon copolymer in which the chain units in the polymer are directly bonded to the polymer molecular chain or a resin composition containing the alicyclic hydrocarbon copolymer. It is possible to prevent the optical element from degrading, such as fluctuations in transmittance. As a result, the lifetime of the optical element can be extended, and a highly reliable optical pickup device can be obtained.

Brief Description of Drawings

FIG. 1 is a side view schematically showing an optical pickup device according to the present invention.

FIG. 2 is a sectional side view of an objective lens exemplified as an optical element according to the present invention.

FIG. 3 is a cross-sectional side view of an objective lens exemplified as an optical element according to the present invention.

FIG. 4 is a cross-sectional side view of an objective lens exemplified as an optical element according to the present invention.

FIG. 5 is a cross-sectional side view of an objective lens exemplified as an optical element according to the present invention.

FIG. 6 is a sectional side view of an objective lens exemplified as an optical element according to the present invention.

FIG. 7 is a sectional side view of a hologram optical element and an objective lens exemplified as an optical element according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION [0029] Specific embodiments of 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.

[0030] The plastic optical lens of the present invention is an alicyclic hydrocarbon copolymer having a repeating unit having an alicyclic structure and a chain unit having a hindered amine structure in the side chain. It is molded using a resin composition containing a cyclic hydrocarbon copolymer. A preferred alicyclic hydrocarbon copolymer in the present invention is a repeating unit (a) in which the repeating unit having an alicyclic structure has an alicyclic structure represented by the following formula (1): (2) and / or the repeating unit (b) having a chain structure represented by the following formula (3) and Z or the following formula (4) so that the total content is 90% by mass or more, and The content of the repeating unit (b) is 1% by mass or more and less than 10% by mass.

[0031] [Chemical 11]

(Formula 1)

[0032] [Chemical 12]

(Formula 2)

[0033] [Chemical 13]

(Formula 3)

[0034] [Chemical 14] ^H R1 3,

η4

[0035] In the formulas (1), (2), (3) and (4), R1 to R13 are each independently a hydrogen atom, a chain hydrocarbon group, a halogen atom, an alkoxy group, a 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 group, imide group, or silyl group) Represents a chain hydrocarbon group or the like substituted with. 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 a halogenated alkyl group having, for example, carbon atoms:! -20, preferably 1-10, more preferably 1-6. The chain hydrocarbon group is, 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, and more preferably. Includes 2 to 6 alkenyl groups.

[0036] X in the above formula (1) represents an alicyclic hydrocarbon group, and the number of carbon atoms constituting it is usually 4 to 20, preferably 4 to 10, more preferably 5 ~ 7 pieces. Birefringence can be reduced by setting the number of carbon atoms constituting the alicyclic structure within this range. Further, 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.

[0037] In particular, in the alicyclic hydrocarbon-based copolymer, the chain of the repeating unit (a) is represented by the relation A≤0.3 XB [where A = (the chain of the repeating unit having an alicyclic structure). Weight average molecular weight). B = (weight average molecular weight of alicyclic hydrocarbon copolymer (Mw) X (number of repeating units having alicyclic structure / number of all repeating units constituting alicyclic hydrocarbon copolymer))) It is preferable to satisfy.

(Alicyclic hydrocarbon copolymer)

The alicyclic hydrocarbon group may have a carbon-carbon unsaturated bond, but the content thereof is 10% or less of the total carbon-carbon bond, preferably 5% or less, more preferably 3% or less. is there. By making the carbon-carbon unsaturated bond of the alicyclic hydrocarbon group within this range, transparency, heat resistance Improves. 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.

[0038] Further, the above formula (3) has a carbon-carbon unsaturated bond in the main chain, and the above formula (4) has a carbon-carbon saturated bond in the main chain, When transparency and heat resistance are strongly required, the content of unsaturated bonds is usually 10% or less, preferably 5% or less, more preferably 3% of all carbon-carbon bonds constituting the main chain. % Or less.

[0039] In particular, among the repeating units represented by the formula (1), the repeating unit represented by the following formula (6) is excellent in terms of heat resistance and low water absorption.

[0040] [Chemical 15]

• ■, (Equation 6)

[0041] Among the repeating units represented by the formula (2), the repeating unit force represented by the following formula (7) is excellent in terms of heat resistance and low water absorption.

[0042] [Chemical 16]

· · ■ (Formula 7)

Among the repeating units represented by the formula (3), the repeating unit force represented by the following formula (8) is excellent in terms of heat resistance and low water absorption. [0044] [Chemical 17]

... (Formula 8)

[0045] Among the repeating units represented by the formula (4), the repeating unit force represented by the following formula (9) is excellent in terms of heat resistance and low water absorption.

[0046] [Chemical 18]

[0047] In formula (6), formula (7), formula (8) and formula (9), Ra, Rb, Rc, Rd, Re, Rf, Rg, Rh, Ri, Rj, Rk, Rl, Rm and Rn each independently represent a hydrogen atom or 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.

[0048] Among the repeating units of the chain structure represented by the formula (2) and the formula (3), the repeating unit of the chain structure represented by the formula (3) is the hydrocarbon-based weight obtained. Excellent strength characteristics of coalescence.

[0049] In the present invention, the repeating unit (a) having an alicyclic structure represented by the formula (1) in the alicyclic hydrocarbon copolymer, the formula (2) and / or the formula The total content of the chain-structured repeating unit (b) represented by (3) and Z or formula (4) is usually 90% or more, preferably 95% or more, more preferably, on a weight basis. 97% or more. By making the total content within the above range, low birefringence, heat resistance, low water absorption, and mechanical strength are highly balanced.

[0050] 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% on a weight basis. The range is preferably 1% or more and 8% or less, more preferably 2% or more and 6% or less. Repeating unit (b ) Is in the above range, low birefringence, heat resistance and low water absorption are highly balanced.

[0051] The molecular weight of the alicyclic hydrocarbon-based copolymer according to the present invention is a polystyrene (or polyisoprene) converted weight average molecular weight measured by gel “permeation” chromatography (hereinafter referred to as GPC). (Mw), 1,000 to 1,000,000, preferred <is 5,000 to 500, 00, more preferred <is 10,000 to 300,000, most preferred <is 50,000 to It is in the range of 250,000. If the weight-average molecular weight (Mw) of the alicyclic hydrocarbon copolymer is too small, the strength properties of the molded product are inferior, and conversely if it is too large, the birefringence of the molded product increases.

[0052] The molecular weight distribution of such a copolymer can be appropriately selected according to the purpose of use, but the weight average molecular weight (Mw) in terms of polystyrene or polyisoprene measured by GPC and the number average molecular weight (Mn ) And the ratio (Mw / Mn) is usually 2.5 or less, preferably 2.3 or less, more preferably 2 or less. When Mw / Mn is within this range, mechanical strength and heat resistance are highly balanced.

[0053] The glass transition temperature (Tg) of the copolymer may be appropriately selected depending on the purpose of use, but is usually 50. C-250. C, preferably 70. C ~ 200. C, more preferably 90. C ~ 180. C. (Hinderdamine-containing chain unit)

The hindered amine-containing chain unit copolymerized with the alicyclic hydrocarbon-based copolymer is represented by the following formula (5).

[0054] [Chemical 19]

(Formula 5) In the above formula (5), R14 to R19 are each independently a hydrogen atom, or a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a t-butyl group, or a pentyl group. Base Represents an alkyl group such as a hexyl group, and Y represents an alkylene group having 1 to 10 carbon atoms or an ester bond.

[0056] The amount copolymerized in the alicyclic hydrocarbon copolymer is 0.01 to 50 parts by mass of the hindered amine-containing chain unit with respect to 100 parts by mass of the repeating unit having an alicyclic structure. .

[0057] When molding is performed using the alicyclic hydrocarbon-based copolymer having a hindered amine-containing chain unit, the copolymer can be used alone or an alicyclic hydrocarbon-based copolymer that does not include a hindered amine site. It may also be used as a resin composition to which additives such as various stabilizers are added as required.

(Method for producing alicyclic hydrocarbon copolymer)

The production method for producing the alicyclic hydrocarbon copolymer is as follows: (1) Aromatic vinyl compound is copolymerized with another monomer that can be copolymerized, and the main chain and aromatic ring are not carbon-carbon. Examples thereof include a method of hydrogenating a saturated bond, and (2) a method of copolymerizing an alicyclic vinyl compound with another monomer copolymerizable and hydrogenating if necessary.

[0058] When the hindered amine-containing chain unit is copolymerized, a polymerizable hindered amine compound having a vinyl group may be copolymerized with the above monomer. At this time, the copolymer can be copolymerized with the above monomer. If it is a thing, you may use it individually or in combination of 2 or more types.

[0059] The weight average molecular weight and the number average molecular weight of the repeating unit chain derived from the compound (a ') are, for example, the main chain of the aromatic bur copolymer described in the document Macromorecules 1983, 16, 1925-1928 This can be confirmed by, for example, measuring the molecular weight of the aromatic bur chain taken out by reductive decomposition after ozone addition of the middle unsaturated double bond.

[0060] The molecular weight of the copolymer before hydrogenation is a weight average molecular weight (Mw) in terms of polystyrene or polyisoprene measured by GPC, and is 1,000 to 1,000,000, preferably 5,000. 0 to 500,000, more preferred <is in the range of 10,000 to 300,000. If the weight average molecular weight (Mw) of the copolymer is too small, the strength characteristics of the resulting alicyclic hydrocarbon copolymer molded product will be inferior, and conversely if it is too large, the hydrogenation reactivity will be inferior. .

[0061] Specific examples of the aromatic vinyl compound used in the method (1) above include, for example, styrene, a-methylol styrene, monoethyl styrene, monopropino styrene, Isopropylstyrene, _a- t butylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-tert-butylstyrene, 5-tert-butyl-2-methylstyrene, Monochlorostyrene, dichlorostyrene, monofluorostyrene, 4-phenylstyrene, etc. are mentioned, and styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, etc. are preferred.

[0062] Specific examples of the alicyclic vinyl compound used in the method (2) include, for example, cyclobutylethylene, cyclopentylethylene, cyclohexylethylene, cycloheptylethylene, cyclooctylethylene, norbornyl. Nylethylene, dicyclohexyleneethylene, 1-methylcyclohexylethylene, _t-butylcyclohexylethylene, cyclopentenyleneethylene, cyclohexenyleneethylene, cycloheptenyleneethylene, cyclooctenoleethylene, cyclodecenyleneethylene, Nonolebonenolenylene ethylene, a-methylcyclohexenylethylene, and _t-butylcyclohexenylethylene are exemplified, and among these, cyclohexylethylene and _α- methylcyclohexylethylene are preferable.

[0063] These aromatic vinyl compounds and alicyclic vinyl compounds can be used alone or in combination of two or more.

[0064] Other monomers that can be copolymerized are not particularly limited, but chain bull compounds, chain conjugation compounds, and the like are used. Excellent operability and excellent strength characteristics of the resulting alicyclic hydrocarbon copolymer.

[0065] Specific examples of the chain bur compound include chain olefin monomers such as ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, etc .; 1-cyanoethylene (acrylonitrile), 1 —Cyano-1-methylethylene (methacrylonitrile), 1-Ciano

_ 1 _ Nitryl monomers such as ethylene (acrylic acrylonitrile); 1- (methoxycarbonyl) -1-methylethylene (methylesterol methacrylate), 1- (ethoxycarbonyl) 1- Methylethylene (ethyl ester methacrylate), 1- (propoxy carbonyl) -1-methylethylene (propyl methacrylate), 1- (butoxycarbonyl ester) 1-methylethylene (butyl ester methacrylate), 1 —Methoxycarbo (Meth) acrylate monomers such as nylethylene (acrylic acid methyl ester), 1 ethoxycarbonylethylene (acrylic acid ethyl ester), 1 propoxycarbonylethylene (acrylic acid propyl ester), 1 butoxycarbonylethylene (acrylic acid butyl ester), Examples include unsaturated fatty acid monomers such as 1_carboxyethylene (acrylic acid), 1_carboxy-1-methylethylene (methacrylic acid), and maleic anhydride. Among them, ethylene, in which chain olefin monomers are preferred, Propylene and 1-butene are most preferred.

[0066] Examples of the chain conjugation include 1,3_butadiene, isoprene, 2,3-dimethyl_1,3-butadiene, 1,3_pentagen, and 1,3_hexagen. Of these chain vinyl compounds and chain conjugate gens, butadiene and isoprene are particularly preferable, where chain conjugate gens are preferred. These chain bull compounds and chain conjugation gens can be used alone or in combination of two or more.

[0067] These chain vinyl compounds can be used alone or in combination of two or more.

[0068] Specific examples of polymerizable hindered amine compounds include 1, 2, 2, 6, 6 pentamethyl.

4-piveridyl methacrylate, 2, 2, 6, 6 tetramethyl-4-piperidyl methacrylate, 4 (5-hexenyl) 2, 2, 6, 6 tetramethylpiperidine and the like are preferably used.

[0069] The method for polymerizing the compound (a ') is not particularly limited. However, the batch polymerization method (batch method), the monomer sequential addition method (polymerization is performed using a part of the total amount of monomers used). After the start, the remaining monomers are added successively and polymerization is carried out to obtain a method. In particular, when the monomer sequential addition method is used, a hydrocarbon copolymer having a preferred chain structure can be obtained.

[0070] According to the monomer sequential addition method, the uniformly mixed monomer is sequentially added into the polymerization system, and therefore, unlike the batch method, the monomer polymerization is performed in the growth process by polymer polymerization. Since the selectivity can be further lowered, the resulting copolymer has a more random chain structure. In addition, since the heat of polymerization reaction in the polymerization system can be kept small, the polymerization temperature can be kept low and stable.

[0071] 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% of the monomer as the initial monomer in the polymerization reactor in advance. Addition to initiate polymerization. When the amount of the initial monomer 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.

[0072] The polymerization conversion of the initial monomer is 70% or more, preferably 80% or more, more preferably

If the reaction is continued until 90% or more, the chain structure of the resulting copolymer becomes more random. Thereafter, the rate of force for continuously adding the remainder of the monomer is determined in consideration of the consumption rate of the monomer in the polymerization system.

[0073] Usually, the polymerization addition rate of the initial monomer is 90. When the time required to reach / o is T and the ratio of initial monomer to the total monomer used (.) is I, the time given by the relational expression [(100—1) ΧΤ / Ι] It is determined so that the addition of the remaining monomer is completed within a range of 3 times, preferably 0.8 to 2 times, more preferably 1 to 1.5 times. 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 monomer addition is within the above range, the chain structure of the resulting copolymer becomes more random.

[0074] The polymerization reaction is not particularly limited, such as radical polymerization, anion polymerization, cationic polymerization, etc., but the polymerization operation, the ease of the hydrogenation reaction in the subsequent steps, and the hydrocarbon-based copolymer finally obtained In view of the mechanical strength, the anion polymerization method is preferred.

[0075] In the case of radical polymerization, in the presence of an initiator, usually at 0 ° C to 200 ° C, preferably 20 ° C to 150 ° C, bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc. In particular, bulk polymerization and suspension polymerization are desirable when it is necessary to prevent impurities from being mixed into the resin. Examples of radical initiators include benzoyl peroxide, lauroyl peroxide, organic peroxides such as t_butyl-peroxy_2_ethylhexanoate, azoisobutyronitrile, 4,4-azobis-1,4_cianopentanoic acid, and azodibenzoyl. Water-soluble catalysts such as azo compounds, potassium persulfate and ammonium persulfate can be opened. An initiator or the like can be used.

[0076] In the case of anionic polymerization, in the presence of an initiator, usually in a temperature range of 0 ° C to 200 ° C, preferably 20 ° C to 100 ° C, particularly preferably 20 ° C to 80 ° C, Although methods such as bulk polymerization, solution polymerization, and slurry polymerization can be used, solution polymerization is preferable in view of removal of heat of reaction. 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 ^ anthane, n-hexane, n-heptane, and iso-octane; cyclopentane, cyclohexane, Alicyclic hydrocarbons such as methylcyclopentane, methylcyclohexane, and decalin; aromatic hydrocarbons such as benzene and toluene, etc. are mentioned, among which aliphatic hydrocarbons and alicyclic hydrocarbons are used. Further, it can be used as it is as a solvent inert to the hydrogenation reaction. 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 mass with respect to 100 parts by mass of all the monomers used.

[0077] Examples of the anion polymerization initiator include mono-organic lithium such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, and phenyllithium, dilithiomethane, 1,4-dibutane, A polyfunctional organolithium compound such as 1,4-dirich-2-ethylcyclohexane can be used.

[0078] In the polymerization reaction, a polymerization accelerator, a randomizer (an additive having a function of preventing a chain of a certain component from becoming long), or 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, for example, dimethyl ether, jetyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, diphenyl ether, ethylene glycol retino enoenoate, ethylene glycono methino enoeno enoenoate. Etherol compounds; tertiary amine compounds such as tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, etc .; alkali metal alkoxide compounds such as potassium _ t _ amyloxide, potassium _ t _ butyloxide; triphenyl And phosphine compounds such as phosphine. These Lewis base compounds can be used alone or in combination of two or more. [0079] The polymer obtained by the above radical polymerization or canyon polymerization can be recovered by a known method such as a steam stripping method, a direct desolvation method or an alcohol coagulation method. Further, when a solvent inert to the hydrogenation reaction is used during the polymerization, the polymer is not recovered from the polymerization solution and can be used as it is in the hydrogenation step.

(Method for hydrogenating unsaturated bonds)

When carrying out hydrogenation reactions such as carbon-carbon double bonds and unsaturated bonds of the main chain of unsaturated rings such as aromatic rings or cycloalkene rings of the copolymer before hydrogenation, the reaction method and reaction form are special. However, a hydrogenation method that can increase the hydrogenation rate and has little polymer chain scission reaction that occurs simultaneously with the hydrogenation reaction is preferable. For example, in an organic solvent, nickel, Examples thereof include a method 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.

[0080] 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 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 usually 0.01 to 80% by weight, preferably 0. It is in the range of 05-60% by weight. Homogeneous catalysts are catalysts that combine nickel, cobalt, titanium, or iron compounds with organometallic compounds (eg, organoaluminum compounds, organolithium compounds), or organometallic complex catalysts such as rhodium, palladium, platinum, ruthenium, rhenium, etc. Can be used. As the nickel, cobalt, titanium, or iron compound, for example, acetyl acetone salt, naphthene salt, cyclopentagenyl compound, cyclopentadienyl diclonal compound of various metals and the like are used. As the organoaluminum compound, alkyl aluminum such as triethylaluminum and triisobutylaluminum, aluminum halide such as jetylaluminum chloride and ethylaluminum dichloride, alkylaluminum hydride such as diisobutylaluminum halide and the like are preferably used. .

[0081] Examples of organometallic complex catalysts include _Ί -dichroic-π-benzene complexes, dichloro-tris ( _{triphenylphosphine} ) complexes, hydrido- _{monochromic-triphenylphosphines of} the above metals. N) complexes and the like are used. These hydrogenation catalysts can be used alone or in combination of two or more, and the amount used is usually from 0.01 to 100 on a weight basis relative to the polymer. Parts, preferably 0.05 to 50 parts, more preferably 0.:! To 30 parts.

[0082] The hydrogenation reaction is preferably performed at a temperature of 10 ° C to 250 ° C, preferably 50 ° C because the hydrogenation rate can be increased and the polymer chain scission reaction that occurs simultaneously with the hydrogenation reaction can be reduced. C to 200 ° C, more preferably 80 ° C to 180 ° C. The hydrogen pressure is usually 0. IMPa to 30 MPa. In addition to the above reasons, from the viewpoint of operability, it is preferably lMPa to 20 MPa, more preferably 2 MPa to:! OMPa.

[0083] The hydrogenation rate of the hydride obtained in this way is measured by ¹ H_NMR as follows: main chain carbon-carbon unsaturated bond, aromatic carbon-carbon double bond, unsaturated ring carbon —All of 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.

[0084] 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 directly removed from the hydride solution by drying, and the hydride solution is poured into a poor solvent for the hydride, A method of solidifying the hydride can be used.

(Resin composition)

The plastic optical element of the present invention may be molded using a resin composition containing various stabilizers in the alicyclic hydrocarbon copolymer.

[0085] Examples of the stabilizer according to the present invention include a phenol stabilizer, a hindered amine stabilizer, a phosphorus stabilizer, and a thio stabilizer. By combining these stabilizers with an appropriate amount of resin, synergistically enhances the deterioration-inhibiting effect against short-wavelength light irradiation, together with hindered amine moieties bound in the resin molecules without reducing transparency and low water absorption. It is possible to obtain a highly reliable optical pickup device.

As the preferred phenol-based stabilizer, conventionally known ones can be used. For example, 2-t-butyl-1-6- (3_t_butyl_2-hydroxy-5-methylbenzyl) _4-methylol Japanese Patent Laid-Open No. 63-179953 and Japanese Patent Application Laid-Open No. 63-179953 and 2,4 di-tert-amyl 6- (1- (3,5-di-tert-aminol-2-hydroxyphenyl) phenyl) phenyl acrylate 1— Atallate compounds described in Japanese Patent No. 168643; Octadecinole 3— (3,5-di-t_butyl _4-hydroxyphenyl) propionate, 2,2′-methylene monobis (4-methyl mono-6— t-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethylol 2,4,6-tris (3,5 — Di _t_butyl _4—hydroxybenzyl) benzene, tetrakis (methylene 1 3 _ (3 ', 5, 1 di _t_butyl 1 4'-hydroxyphenyl propionate) methane [ie penta erythrimethyl-tetrakis ( 3— (3, 5—di _t_butyl _4—hydride Alkyl substituted phenolic compounds such as trioxyglycol bis)), triethylene glycol bis (3_ (3_t_butyl_4-hydroxy-1-5_methylphenyl) propionate); 6_ (4-hydroxyl 3,5_di-tert-butylanilino) -1,2,4_bisoctylthio-1,3,5_triazine, 4 bisoctylthio 1,3,5 triazine, 2 octylthio 4,6 bis (3,5-ditert-butyl) 4-Oxanilino) 1,3,5-Triazine-containing phenolic compounds such as triazine.

Preferred hindered amine stabilizers include bis (2, 2, 6, 6 tetramethyl-4-piperidyl) sebacate, bis ((2, 2, 6, 6 tetramethyl-4-piperidyl) succinate, bis (1, 2, 2, 2, 6, 6 Pentamethyl-4-piperidyl) sebacate, bis (N-tatoxy-1,2,2,6,6 Tetramethyl-4-piperidyl) sebacate, bis (N-benzyloxy-2,2,6,6 tetramethyl-4-piperidyl) sebacate , Bis (N cyclohexyloxy 2, 2, 6, 6 tetramethyl-4-piperidyl) sebacate, bis (1, 2, 2, 6, 6 _pentamethyl _4-piperidyl) 2 _ (3,5-di-t_butyl _4 —Hydroxybenzyl) _ 2_butyl malonate, bis (1-acryloyl_ 2, 2, 6, 6-tetramethyl _4 —piperidyl) 2, 2_bis (3,5-di-t_butyl _4-hydroxybenzyl _ 2— Tilmalonate, bis (1, 2, 2, 6, 6 _pentamethyl _4-piperidyl) decaneate, 2, 2, 6, 6-tetramethinole 4-piperidinoremetatalylate, 4_ [3— (3, 5_di-tert-butyl _4-hydroxyphenyl) propionyloxy] _ 1 _ [2_ (3 _ (3, 5-di-t_butyl _4-hydroxyphenyl) propionyloxy) ethyl] _ 2, 2 , 6, 6- Tetramethylpiperidine, 2-methyl-2- (2, 2, 6, 6 tetramethyl-4-piperidyl) amino 1-N— (2, 2, 6, 6 tetramethyl-4-piperidyl) propionamide, tetrakis (2, 2, 6, 6 tetramethyl-4-piperidyl) 1, 2, 3, 4 butanetetracarboxylate, tetrakis (1, 2, 2, 6, 6 _pentamethinole _4-piperidinole) 1, 2, 3, 4_butanetetracarbonate Is mentioned.

[0088] In addition, the preferred phosphorus stabilizer is not particularly limited as long as it is a substance usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphate, phenyl. Diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinolphenyl) phosphite, tris (2,4 di-tert-butylphenyl) phosphite, 10- (3,5-di-t_butyl _4-hydroxybenzyl) _ 9 , 10-dihydro_ 9-oxa 10-phosphaphenanthrene 1-monophosphite compounds such as 10-oxide; 4, 4'-butylidene-bis (3-methyl _ 6 _ t _ butylphenyl di-tridecylphos Diphosphite compounds such as phyto), 4, 4, isopropylidene bis (phenyl didialkyl (C12-C15) phosphite). It is. Among these, tris (noelphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite and the like, which are preferred for monophosphite compounds, are particularly preferable.

[0089] In addition, preferred thio stabilizers include, for example, dilaurinole 3,3 thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3-thio. Dipropionate, Pentaerythritol Tetrakito (i3-lauryl thiopropionate, 3, 9-bis (2-dodecylthioethyl) -2, 4, 8, 10-tetraoxaspiro [5,5] undecane Etc.

[0090] These stabilizers can be used singly 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. It is usually 0.00 :! to 5 parts by weight, preferably 0.01 to :!

[0091] Further, in the present invention, at least selected from the group consisting of the alicyclic hydrocarbon-based copolymer, (1) a soft polymer, (2) an alcoholic compound, and (3) an organic or inorganic filler. Also provided is a resin composition comprising one compounding agent. Add these ingredients Therefore, it is possible to prevent white turbidity in a high-temperature and high-humidity environment for a long time without lowering 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 in the present invention is usually a polymer having a Tg of 30 ° C or lower, and when there are a plurality of Tg's, at least the lowest Tg is 30 ° C or lower. Good.

(1) Soft polymer

Specific examples of the soft polymer is, for example, liquid polyethylene, polypropylene, poly _ 1 - butene, ethylene _a -.. Orefuin copolymer, propylene 'shed one Orefuin copolymer, ethylene' propylene diene copolymer (EPDM ), Olefin-based soft polymers such as ethylene 'propylene' styrene copolymer; isobutylene-based soft polymers such as polyisobutylene, isobutylene.isoprene rubber, isobutylene.styrene copolymer; polybutadiene, polyisoprene, butadiene 'styrene random copolymer Polymer, isoprene 'styrene random copolymer, acrylonitrile' butadiene copolymer, acrylonitrile.Butadiene styrene copolymer, butadiene 'styrene' block copolymer, styrene 'butadiene' styrene 'block copolymer, isoprene. styrene. Gen-based soft polymers such as lock copolymers, styrene'isoprene.styrene.block copolymers; soft polymers containing silicon such as dimethylpolysiloxane, diphenylpolysiloxane, dihydroxypolysiloxane; polybutylatari Soft polymers composed of α, β unsaturated acids such as poly (butyl methacrylate), poly (hydroxyethyl methacrylate), poly (hydroxyethyl methacrylate), poly (acrylo amide), poly (acrylonitrile), butyl acrylate / styrene copolymer; polyvinyl alcohol, poly Soft polymers composed of unsaturated alcohols such as vinyl acetate, butyl stearate, butyl acetate styrene copolymer, and amines or their acyl derivatives or acetals; polyethylene oxide, polypropylene oxide, epichloronohydrin rubber , Such as epoch Fluorine-based soft polymers such as vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, natural rubber, polypeptide, protein, polyester-based thermoplastic elastomer, chlorinated bur-type thermoplastic Other soft polymers such as elastomers and polyamide thermoplastic elastomers can be mentioned. These soft polymers have a crosslinked structure. It may also be one having a functional group introduced by a modification reaction.

[0093] Among the above-mentioned soft polymers, a gen-based soft polymer is preferred. Particularly, a hydride obtained by hydrogenating a carbon-carbon unsaturated bond of the soft polymer has rubber elasticity, mechanical strength, flexibility, and dispersibility. Excellent in terms.

(2) Alcoholic compounds

The alcoholic compound is a compound having at least one nonphenolic 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 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 to or esterified.

[0094] Examples of the dihydric or higher polyhydric alcohol include polyethylene glycol, glycerol, trimethylolpropane, pentaerythritol, diglycerol, triglycerol, dipentaerythritol, 1, 6, 7 trihydroxy-2,2 di ( Hydroxymethyl) 4-oxoheptane, sorbitol, 2-methyl 1, 6, 7 trihydroxy-1,2 hydroxymethanol 4 oxoheptane, 1,5,6-trihydroxy-3-oxohexanepentaerythritol, tris ( 2 Hydroxyethyl) isocyanurate and the like S, particularly a trihydric or higher polyhydric alcohol, more preferably a polyhydric alcohol having 3 to 8 hydroxyl groups. In order to obtain an alcoholic ester compound, glycerol, diglycerol, triglycerol or the like capable of synthesizing an alcoholic ester compound containing α and -diol is preferable.

[0095] Examples of such alcoholic compounds include glycerin monostearate, glycerin monolaurate, glycerin monobehenate, diglycerin monostearate, glycerin distearate, glycerin dilaurate, and pentaerythritol monostearate. Polyvalents such as rate, pentaerythritolol monolaurate, pentaerythritolol monoberate, pentaerythritolinoresire stearate, pentaerythritolinoresiliate laurate, pentaerythritoloretristearate, dipentaerythritol distearate Alcoholic esterified products; 3— (octyloxy) — 1, 2_propanediol, 3_ (decyloxy) — 1, 2_propanedi All, 3- (lauryloxy) 1,2-propanediol, 3- (4-noelphenyloxy) 1,2 propanediol, 1,6 dihydroxy 2,2 di (hydroxymethinole) -7- (4-nonylphenyl) Oxy) 4-oxoheptane, an alcoholic ether compound obtained by the reaction of p-nonylphenyl ether and formaldehyde and glycidol, and a reaction of p-octylphenyl ether and formaldehyde condensate and glycidol. And alcoholic ether compounds obtained by the reaction of a condensate of p-octylphenyl ether and dicyclopentagen with glycidol. These polyhydric alcohol compounds are used alone or in combination of two or more. The molecular weight of these polyhydric alcoholic compounds is not particularly limited, but usually 500 to 2000, preferably 800 to 1500, with little decrease in transparency.

(3) Organic or inorganic filler Organic filler

As an organic filler for organic or inorganic fillers, ordinary organic polymer particles or crosslinked organic polymer particles can be used. For example, polyolefins such as polyethylene and polypropylene; polysalt-vinyl, polysalt-vinyl. Halogen-containing vinyl polymers such as redene; polymers derived from α, β unsaturated acids such as polyarylate and polymetatalylate; unsaturated alcohol forces such as polyvinyl alcohol and polyacetate vinyl; polymers derived from poly; Polymers derived from liethylene oxide or bisglycidyl ethers; Polyolefins Aromatic condensation polymers such as dilenoxides, polycarbonates and polysulfones; Polyurethanes; Polyamides; Polyesters; Aldehyde / phenolic resins; Natural polymer compounds Such as particles or cross-linked particles Rukoto can.

Examples of inorganic fillers 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 sodium carbonate; Group 4 element compounds such as titanium dioxide (titania) and titanium monoxide; Group 6 element compounds of molybdenum dioxide and molybdenum trioxide; Group 7 element compounds such as manganese chloride and manganese acetate; : Group 10 element compounds; Group 11 element compounds such as cuprous iodide; Group 12 element compounds such as zinc oxide and zinc acetate; Aluminum oxide (alumina), aluminum fluoride, Al Group 13 element compounds such as minosilicate (alumina silicate, kaolin, kaolinite); Group 14 element compounds such as silicon oxide (silica, silica gel), graphite, carbon, graphite, glass; carnal stone, kainite, mica (my And natural mineral particles such as vylose ore.

[0097] The compounding amount of the compounds (1) to (3) is determined depending on the combination of the compound compounded with the alicyclic hydrocarbon copolymer, but generally, if the compounding amount is too large, the composition The glass transition temperature and transparency of this material are greatly reduced, making it unsuitable for use as an optical material. If the amount is too small, the molded product may become cloudy at high temperature and high humidity. The amount of the compound is usually from 0.01 to 10 parts by weight, preferably from 0.02 to 5 parts by weight, particularly preferably from 0.05 to 100 parts by weight based on 100 parts by weight of the alicyclic hydrocarbon copolymer. Add 2 parts by weight. When the blending amount is too small, the effect of preventing white turbidity in a high temperature and high humidity environment cannot be obtained. When the blending amount is too large, the heat resistance and transparency of the molded product are lowered.

(Other ingredients)

In the resin composition of the present invention, as necessary, as other compounding agents, an ultraviolet absorber, a light stabilizer, a near infrared absorber, a coloring agent such as a dye or a pigment, a lubricant, a plasticizer, an antistatic agent, Optical brighteners and the like can be blended, and these can be used alone or in admixture of two or more, and the blending amount is appropriately selected within a range that does not impair the purpose of the present invention.

(Molding material)

The resin composition of the present invention can be obtained by appropriately mixing the above components. The mixing method is not particularly limited as long as each component is sufficiently dispersed in the hydrocarbon polymer. For example, the resin is melted in a mixer, a twin-screw kneader, a roll, a Brabender, an extruder, or the like. And kneading with a suitable solvent, and dissolving and dispersing in a suitable solvent to solidify. When a biaxial 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.

[0098] In addition, the resin composition preferably has a melt index Ml measured under the conditions of a temperature of 260 ° C and a load of 2.16 kg within a range of 20 <MI (gZlO content) 60. . Where Ml The measuring method is based on ASTM D1238. Ml is more preferably 30 <MI (g / 10 minutes) <60.

Here, the above Ml is, for example, control of crystallinity by selection of the types of α-olefin and cyclic olefins and the composition ratios of structural units derived from α-olefin and cyclic olefins, and plasticizers. It can adjust by well-known methods, such as addition of.

[0100] Plasticizers to be added include bis (2-ethylhexyl) adipate, bis (2-butoxycheil) adipate, bis (2-ethylhexyl) azelate, dipropylene glycol dibenzoate, tribenzoate — Η-Butyl, Tri-Cenate, η-Butylacetyl, Epoxylated soybean oil, 2-ethylhexyl epoxidized tall oil, Chlorinated paraffin, Triethyl hexyl phosphate, Tricredinole phosphate, Phosphorus Acid-___________________________________________________ 0_______________________ 0___________________ 0__ 2 Diisonoel, diisodecyl phthalate, ditridecyl phthalate, butylbenzyl phthalate, phthalic acid Cyclohexyl, di-2-ethylhexyl sebacate, tri-2-trimethyltrimellitic acid, Santicizer 278, Paraplex G40, Dra pex 334F, Plastolein 9720, Mesamoll, DNODP-610, HB-40, etc. Are applicable. Selection of the plasticizer and determination of the addition amount are appropriately performed on the condition that the permeability of the cyclic olefin and the resistance to environmental changes are not impaired.

(Plastic optical element)

The plastic optical element according to the present invention is obtained by molding a molding material made of the alicyclic hydrocarbon copolymer or resin composition. The molding method is not particularly limited, but melt molding is preferred in order to obtain an optical element having excellent characteristics such as low birefringence, mechanical strength, and dimensional accuracy. Examples of the melt molding method include press molding, extrusion molding, and injection molding, and injection molding is preferable from the viewpoints of moldability and productivity. The molding conditions are appropriately selected depending on the purpose of use or molding method. For example, the tree temperature in injection molding is usually 150 to 400. Yes, preferably 200-350. C, more preferably in the range of 230 to 330 ° C. If the resin temperature is too low, the fluidity will deteriorate, causing sink marks and distortion in the molded product. If the resin temperature is too high, silver will be decomposed due to thermal decomposition of the resin. There is a risk of forming defects such as occurrence of a trek or yellowing of the optical element.

[0101] The plastic optical element according to the present invention can be used in various forms such as a spherical shape, a rod shape, a plate shape, a columnar shape, a tubular shape, a tube shape, a fiber shape, a film shape or a sheet shape. Moreover, it is excellent in low birefringence, transparency, mechanical strength, heat resistance, and low water absorption.

[0102] Specific examples of the plastic optical element include the following. Optical lenses and optical prisms include: camera imaging lenses; microscopes, endoscopes, telescope lenses, etc .; full-light transmission lenses such as eyeglass lenses; CDs, CD-ROMs, WORM (write-once optical discs) , MO (rewritable optical disc; magneto-optical disc), MD (mini disc), DVD (digital video disc) and other optical disc pickup lens; laser beam printer f 0 lens, sensor lens, etc. Lenses: Prism lenses for camera finders. Optical disc applications include CD, CD-ROM, WORM (recordable optical disc), MO (rewritable optical disc; magneto-optical disc), MD (mini disc), DVD (digital video disc), and the like. Other optical applications include light guide plates such as liquid crystal displays; optical films such as polarizing films, retardation films, and light diffusion films; light diffusion plates; optical cards; and liquid crystal display element substrates.

Among these, an optical lens constituting an optical pickup device requiring low birefringence is suitable as a laser scanning system lens, and is most suitable as an optical system lens of the optical pickup device.

[0104] As an optical system lens of the optical pickup device, for example, an objective lens, an objective lens unit, a coupling lens (collimator), a beam expander, a beam shaper, a correction plate, and the like can be used.

[0105] The objective lens unit is a lens group configured by integrally combining a plurality of single lens optical lenses in the optical axis direction, and as at least one single lens optical lens among the plurality of single lens optical lenses. It is preferable to use the plastic optical element of the present invention. (Optical pickup device)

Next, the optical pickup device of the present invention will be described with reference to FIG. 1 and FIG. Figure 1 FIG. 2 is a schematic configuration diagram of the overall configuration of the optical pickup device, and FIG. 2 is a side view of the main part showing the structure of the objective lens.

[0106] The optical pickup device 1 of the present invention includes a current DVD that applies light having a wavelength of 650 nm (hereinafter referred to as current DVD) and a so-called next-generation DVD that applies light having a wavelength of 405 nm (hereinafter referred to as next-generation DVD). This is a device for reproducing and recording information on the two types of optical information recording media 5.

The optical pickup device 1 of the present invention allows laser light (light) emitted from a laser oscillator (light source) 2 to pass through a collimator lens 3 and an objective lens (plastic optical element) 10 to be described later. A focused spot is formed by collecting on the information recording surface 6 of the optical information recording medium 5 on the axis 4, and the reflected light from the information recording surface 6 is captured by the deflecting beam splitter 7 and re-beamed on the light receiving surface of the detector 8. A spot is formed.

The light source 2 is configured to have a laser diode, and is configured to be able to select and emit light of two types of wavelengths of 650 nm and 405 nm by a known switching method.

[0109] The objective lens 10 according to the present invention is produced by molding the above-described resin composition by injection molding. As shown in FIG. 2, the objective lens 10 is a single lens having a double-sided aspheric surface, and has a predetermined light flux passing through the optical surface 11 on one of the optical surfaces 11 (light source side) in advance. It has an optical path difference providing structure (fine structure) 20 that provides a predetermined optical path difference.

[0110] The optical path difference providing structure 20 includes three annular lens surfaces whose optical surface 11 is centered on the optical axis 4 (hereinafter, the first annular lens surface 21, the second annular lens surface 22, Of the three annular lens surfaces 21 to 23, the adjacent annular lens surfaces 21 to 23 have different refractive powers.

[0111] The first annular lens surface 21 and the third annular lens surface 23 are on the same optical surface 11, and the second annular lens surface 22 is a surface translated from the optical surface 11. Yes. The first ring-shaped lens surface 21 transmits light of both wavelengths 650 nm and 405 nm, and the second ring-shaped lens surface 22 transmits light of wavelength 650 nm corresponding to the current DVD, and the third ring-shaped lens surface 23 Passes light with a wavelength of 405nm, which is compatible with next-generation DVDs. The light that has passed through each of the annular lens surfaces 21 to 23 is condensed at the same position on the information recording surface 6.

[0112] In FIG. 2, the first annular lens surface 21 and the third annular lens surface 23 are the same optical surface. The first and third annular lens surfaces 21 and 23 do not have to be provided on the same optical surface, and the second annular lens surface 22 is parallel to the optical surface 11. Force on the moved surface It is not necessary that the surface is moved in parallel. Further, the number of the three annular lens surfaces 21 to 23 may be five or at least three or more.

[0113] Since the lens 10 uses the resin composition described above, the first annular lens surface 21 and the second annular lens surface of the mold are formed when the lens 10 is melted and injected into the mold. 22, The resin has surely spread to the part corresponding to the boundary part of the third annular lens surface 23. Therefore, the lens 10 is provided with the optical path difference providing structure 20 with high accuracy.

[0114] By the action of the optical path difference providing structure 20 formed in this way, the lens 10 can record the information recording surface of the light emitted from the light source 2 against a plurality of types of optical information recording media 5 such as the current DVD and the next-generation DVD. It is possible to collect light toward 6 and to collect light reflected by the information recording surface 6 toward the detector 8 with high reliability.

[0115] Further, since the resin composition contains an antioxidant, even when light of 405 nm for reproducing and recording information of the next-generation DVD is transmitted, white turbidity and refractive index fluctuation hardly occur. . Therefore, the optical pickup device 1 can be operated with high pickup characteristics over a long period of time.

[0116] The objective lens 10 according to the present invention is not limited to the one having the optical path difference providing structure 20, but may be used as the lenses 10a to 10e having the structures 20a to 20d shown in FIGS. .

[0117] The optical path difference providing structure 20a in Fig. 3 is composed of a plurality of diffraction ring zones 21a with the optical axis 4 as the center, and the plurality of diffraction ring zones 21a have a sawtooth cross section and each diffraction ring zone 21a. The optical surface 1 la is a discontinuous surface. Further, the plurality of diffraction ring zones 21a are formed so as to increase in thickness due to the force S away from the optical axis 4. The lens 10a shown in FIG. 3 is a so-called diffraction lens.

[0118] The optical path difference providing structure 20b in FIG. 4 has a plurality of annular recesses 21b that cause a phase difference around the optical axis 4 in a concentric manner. The ring-shaped concave portions 21b are formed on each of the optical surfaces ib around the optical axis 4 (five upper and lower optical surfaces around the optical axis 4 in FIG. 4). Adjacent ring-shaped recesses 21b are continuously integrated with each other, and each ring-shaped recess 21b has a step-like cross section as a whole. Also, each annular recess 2 The optical surface 22b forming lb is a surface translated from the optical surface l ib. The lens 10b shown in FIG. 4 is a so-called phase difference lens.

[0119] In Fig. 4, the adjacent annular zone recesses 21b are continuous and integrated, and the entire cross section is stepped. However, the annular zone recess 21b is simply formed on the optical surface l ib. May be provided individually (in this case, for example, the lens 10 has the same structure as the lens 10 shown in FIG. 2). In FIG. 4, the annular recess 21b is concentrically formed. However, as shown in FIG. 5, the lens 10c having the protrusion 23b on the third annular lens surface 23 of FIG. Good, (In Fig. 5, components similar to those in Fig. 2 are given the same reference numerals).

[0120] The optical path difference providing structure 20d in Fig. 6 is composed of a plurality of diffraction ring zones 21d centered on the optical axis 4, the plurality of diffraction ring zones 21d have a sawtooth cross section, and each diffraction ring zone 21d The optical surface l id is a discontinuous surface. The cross section of each diffraction zone 21d is a three-step 22d step shape along the optical axis direction, and the optical surface 12d of each step 22d is a discontinuous surface that is perpendicular to the optical axis 4. ing.

[0121] Note that the lens 10d shown in FIG. 6 includes, for example, a hologram optical element (HOE) 10e having an optical path difference providing structure 20d similar to FIG. 6 and an objective lens 1 Of as shown in FIG. It may be configured. In this case, the hologram optical element 10e uses a plate-like optical element, and the optical path difference providing structure 20d is provided on the surface of the objective lens 10f of the optical element. The optical pickup device 1 according to the present invention may reproduce and record information on three types of optical information recording media 5 such as a CD, a current DVD, and a next-generation DVD. The combination of the optical information recording medium 5 for reproducing and recording information with the optical pickup device 1 is a design matter and is set as appropriate.

[0122] As described above, the plastic optical element of the present embodiment includes an alicyclic hydrocarbon copolymer in which a chain unit having a hindered amine structure in the side chain is directly bonded to a polymer molecular chain, or the alicyclic ring. Since it is molded using a resin composition containing a hydrocarbon copolymer, bleeding out of the hindered amine site having a light stabilizing function is suppressed, and the hindered amine is uniformly dispersed in the resin composition. As a result, even when irradiation with light having a short wavelength such as 405 nm is continuously received, it is possible to effectively suppress the white turbidity and refractive index fluctuation and deterioration of the optical element. In other words, improve the light stability of the optical element This characteristic can be maintained and the characteristics can be maintained for a long time.

Therefore, for example, information can be read and written with good pickup characteristics over a long period of time on an optical information recording medium having a high information density, such as a Blu-ray Disc, and the optical pickup device is reliable. Can be obtained.

[0124] In addition, an optical element formed by appropriately selecting various stabilizers from a phenol-based stabilizer, a hindered amine-based stabilizer, a phosphorus-based stabilizer, and a thio-based stabilizer and adding them to the resin composition. It is possible to suppress the fluctuation of the optical characteristics of the film more synergistically.

[0125] Further, since the melt index is in a range suitable for a molding method such as injection molding, the melted resin composition has an appropriate fluidity. For example, the optical element is molded by injection molding or the like. In this case, the molten resin composition reaches the tip of the portion corresponding to the fine structure, and the optical element thus molded is provided with a predetermined fine structure formed with high accuracy. .

It should be noted that 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.

[0127] Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

(Production Example 1)

The inside of the stainless steel reactor equipped with a stirrer was thoroughly dried and purged with nitrogen, and then charged with 300 parts by mass of dehydrated cyclohexane, 60 parts by mass of styrene, and 0.38 parts by mass of dibutyl ether, 60 ° C While stirring at 0, 36 parts by mass of n-butyllithium solution (15% hexane solution) was added to initiate the polymerization reaction. After conducting the polymerization reaction for 1 hour, 8 parts by mass of styrene, 12 parts by mass of isoprene, and 1, 2, 2, 6, 6 _pentamethyl _4-piveridyl methacrylate in an amount of 0.8 parts by mass in the reaction solution. After adding a mixed monomer consisting of 1 and a polymerization reaction for 1 hour, 0.2 part by mass of isopropyl alcohol was added to the reaction solution to stop the reaction.

[0128] Next, 300 parts by mass of the polymerization reaction solution was transferred to a pressure-resistant reactor equipped with a stirrer, and a silica-alumina supported nickel catalyst (manufactured by JGC Chemical Industry Co., Ltd .; E22 U, Nikkenore) was used as the hydrogenation catalyst. (Supported amount 60%) 10 parts by mass were added and mixed. Hydrogen gas inside the reactor Then, hydrogen was supplied while stirring the solution, and the temperature was set to 160 ° C. Then, a hydrogenation reaction was performed at a pressure of 4.5 MPa for 8 hours.

[0129] After completion of the reaction, the reaction solution is filtered to remove the hydrogenation catalyst, and after diluting with 800 parts by mass of cyclohexane, the reaction solution is poured into 3500 parts by mass of isopropanol. Was precipitated. Next, this copolymer was collected by filtration and dried under reduced pressure at 80 ° C. for 48 hours to obtain Resin 1. Mw of the obtained copolymer was 86,400, MwZMn was 1.15, hydrogenation rate of the main chain and aromatic ring was 99.9%, and Tg was 127.2 ° C.

(Production Example 2)

Manufacture in the same way, except that 1, 2, 2, 6, 6 _pentamethinole _4-piperidyl methacrylate was added from 0.8 parts by weight to 8 parts by weight. Polymerization was performed to obtain Resin 2. The copolymer obtained had an Mw of 84, 400, an MwZMn of 1.18, a hydrogenation rate of the main chain and the aromatic ring of 99.9%, and a Tg of 126.8 ° C.

(Production Example 3)

Production In the first column, copolymerization was carried out in the same manner as above except that 1,2,2,6,6-pentamethinole 4-piperidylmethacrylate was not added, and resin 3 was obtained. The copolymer obtained had an Mw of 87,200, an Mw / Mn of 1.17, a hydrogenation rate of the main chain and the aromatic ring of 99.9%, and a Tg of 127.8 ° C.

Example 1

[0130] A biaxial kneader (manufactured by Toshiba Machine Co., Ltd.) at a composition ratio of 0.5 parts by mass of pentaerythritol distearate as a surfactant with respect to 100 parts by mass of the resin 1 obtained in Production Example 1. TEM-35B, screw diameter 37 mm, L / D = 32, screw rotation speed 150 rpm, resin temperature 240 ° C., feed rate 10 kg), kneaded, and pelletized. The obtained pellets were dried for 2 hours at 70 ° C using a hot air dryer in which air was circulated to remove moisture, and then the cylinder temperature was 280 ° C using an injection molding machine (FANUC AUTOSHOT MODEL 30A). C, mold temperature 80 ° C, primary injection pressure 98.lMPa, secondary injection pressure 78.4MPa were injection-molded to obtain a resin substrate, molded plate 1 having a thickness of 30mm and a thickness of 3mm.

Example 2

[0131] In Example 1, tetrakis (2, 2, 6, 6) was used as a hindered amine stabilizer during kneading. 6-Tetramethyl-4-piperidyl) 1, 2, 3, 4-butanetetracarboxylate 1.0 A molded plate 2 was obtained in the same manner except that a mass part was added.

Example 3

[0132] In Example 1, instead of the resin 1, the same operation was carried out except that 20 parts by mass of the resin 2 and 80 parts by mass of the resin 3 were mixed together, whereby a molded plate 3 was obtained. .

(Comparative Example 1)

With a composition ratio of 0.5 parts by mass of pentaerythritol distearate as a surfactant with respect to 100 parts by mass of the resin 3 obtained in Production Example 3, a biaxial kneader (Toshiba Machine Co., Ltd., TEM-35B , Screw diameter 37 mm, L / D = 32, screw rotation speed 150 rpm, resin temperature 240 ° C., feed rate 10 kg / hour), kneaded, and pelletized. The obtained pellets were dried for 2 hours at 70 ° C using a hot air dryer in which air was circulated to remove moisture, and then the cylinder temperature was 280 ° C using an injection molding machine (FANUC AUTOSHOT MODEL 30A). C, mold temperature 80 ° C, primary injection pressure 98.lMPa, secondary injection pressure 78.4MPa were injection molded to obtain a resin substrate, molded plate 4 of 30mm and thickness 3mm.

(Comparative Example 2)

In Comparative Example 1, tetrakis (2, 2, 6, 6-tetramethyl _4-piperidyl) 1, 2, 3, 4_butanetetracarboxylate is added as a hindered amine stabilizer during kneading. A molded plate 5 was obtained in the same manner as in the above.

[Evaluation of resin molded plate]

The molded plates obtained in Examples 1 to 3 and Comparative Examples 1 and 2:! To 5 were evaluated for melting characteristics and optical characteristics by the following methods.

(Melt index measurement)

For each plastic optical element (molded plate):! To 5, the melt index at a temperature of 260 ° C. and a load of 2.16 kg was measured according to the method defined in ASTM D1238. (Evaluation of coloring and transparency of molded products)

With respect to the molded plates 1 to 5, the light transmittance was measured at a wavelength of 400 nm, and the color tone via the transmitted light was visually observed, and the colorability and transparency were evaluated according to the following criteria.

[0133] A: The light transmittance is 90% or more, and coloring is not observed. [0134] ○: The light transmittance is 85% or more and less than 90%, and coloring is not seen.

[0135] Δ: Light transmittance is 85% or more and less than 90%.

[0136] X: The light transmittance is less than 85%, and coloring is observed, which causes a practical problem.

(Evaluation of light durability)

In a constant temperature and humidity chamber at 80 ° C and 55% RH, use the optical pickup device shown in Fig. 1, the laser diode force of the light source 2 on each of the molding plates 1 to 5, and light with a wavelength of 405 nm. Was subjected to continuous irradiation for 250 hours as a circular spot light with a diameter of 1 cm, and then the laser irradiation spot was visually observed and the durability was evaluated according to the following criteria.

[0137] A: After continuous irradiation, no alteration was observed in the laser irradiated portion.

[0138] Δ: Slight turbidity is observed in the laser irradiated part after continuous irradiation, but it is within the allowable range for practical use.

[0139] X: After continuous irradiation, a white turbidity phenomenon is observed at the laser irradiation site, but there is a problem in practical use.

[0140] Table 1 shows the results of evaluation of melting characteristics and optical characteristics of each molded plate:!

[0141] [Table 1]

[0142] As shown in Table 1, the molded plate formed using the resin composition of the present invention does not cause coloring or cloudiness even when continuously irradiated with light having a short wavelength for a long time, and has high transparency. Was able to be maintained.

Example 4

[0143] A plastic optical element (objective lens) having the same composition as that of the plastic optical element of the present invention described in Examples 1 to 3 and having the configuration illustrated in Figs. 2 to 7 was manufactured by injection molding. Each optical pickup device was manufactured with the configuration shown in FIG. Next, using each optical pick-up device, recording and reproduction on a DVD were performed using light of a wavelength of 405 nm by a laser diode.

As a result, all the optical pickup devices using the plastic optical element of the present invention showed good pickup characteristics.

Claims

The repeating unit (a) having an alicyclic structure represented by the following formula (1) and the following formula (2) and Z or the following formula (3) and Z or the following formula (4) A repeating unit (b) having a chain structure and a chain unit (c) having a hindered amine structure represented by the following formula (5) in a side chain, and the repeating unit (a) and the repeating unit The total content of (b) is 90% by weight or more, and the content of the repeating unit (b) is 1% by weight or more and less than 10% by weight or the alicyclic An optical element formed by molding using a resin composition containing a hydrocarbon-based copolymer. [Chemical 1]

(Formula 1)

[Chemical 2]

2)

[Chemical 3]

(Formula 3)

[Chemical 4] (Formula 4)

^H R1 3 n4

[Chemical 5]

… Pa 5)

[In Formula (1), X is an alicyclic hydrocarbon group, and in Formula (1), Formula (2), Formula (3), and Formula (4), R1 to R13 are each independently a hydrogen atom, 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, cyan group, amide group, imide group, or silyl group), and in formula (5), R14 to R19 each independently represents a hydrogen atom or an alkyl group, Y Represents an alkylene group having from 10 to 10 carbon atoms or an ester bond. ]

[2] The alicyclic hydrocarbon copolymer contains at least one stabilizer selected from a phenol stabilizer, a hindered amine stabilizer, a phosphorus stabilizer, and a thio stabilizer. 2. The optical element according to claim 1, wherein the optical element is formed.

[3] Melt index (Ml) value of the alicyclic hydrocarbon copolymer or the resin composition measured at a temperature of 260 ° C and a load of 2.16 kg 20 Ml (g / 10 min) In the range of 60,

The optical element according to claim 1 or 2, wherein a predetermined fine structure is provided on at least one optical surface. An optical pickup device that reproduces and / or records information on an optical information recording medium.

A light source that emits light;

The optical element unit is

A repeating unit (a) having an alicyclic structure represented by the following formula (1) and a chain structure represented by the following formula (2) and Z or the following formula (3) and Z or the following formula (4) The repeating unit (b) and a chain unit (c) having a hindered amine structure represented by the following formula (5) in the side chain, the repeating unit (a) and the repeating unit (b) The alicyclic hydrocarbon copolymer or the alicyclic hydrocarbon having a total content of 90% by weight or more and a content of the repeating unit (b) of 1% by weight or more and less than 10% by weight An optical pickup device comprising an optical element formed by using a resin composition containing a copolymer.

[Chemical 6]

(Formula 1)

[Chemical 7]

(Formula 2)

[Chemical 8] 3)

[Chemical 9]

(Formula 4)

[Chemical 10]

(Formula 5)

[5] The optical pickup device according to [4], wherein the light source emits light having a wavelength of 390 to 420 [nm].