JP2008247942A - Plastic optical element material, plastic optical element obtained using the same, and optical pickup apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic optical element material that exhibits enhanced light stability and excellent transparency and can maintain the properties for long hours, a plastic optical element obtained using the same, and an optical pickup apparatus having good pickup properties obtained using the plastic optical element. <P>SOLUTION: The plastic optical element material is a resin composition comprising an oligosiloxane-modified norbornene resin obtained by ring-opening metathesis polymerization of a mixture of a norbornene monomer having a thioacetal structure with an oligosiloxane compound bearing a vinyl group and subsequent conversion of a carbon-carbon double bond in the molecular chain into a single bond. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plastic optical element material suitably used for a plastic optical element and the like, a plastic optical element using the same, and an optical pickup device to which the plastic optical element is applied.

  2. Description of the Related Art Conventionally, recording devices such as a player, a recorder, and a drive that read and record information on an optical information recording medium (hereinafter abbreviated as a medium) such as MO, CD, and DVD are provided with an optical pickup device. 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 receives the light from a reflection layer or a light receiving element of the medium. And an optical element such as a lens for condensing light.

  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 to which optical elements can be applied, copolymers of cyclic olefins and α-olefins (for example, see Patent Document 1) are known.

  By the way, for example, in the case of an information device capable of reading and writing information on a plurality of types of media such as a CD / DVD player, the optical pickup device has a configuration corresponding to the difference in the shape of both media and the wavelength of light to be applied. It is necessary to. In this case, it is preferable from the viewpoint of cost and pickup characteristics that the optical element unit is common to any medium.

  In recent years, as a medium capable of recording information at a higher density than CD and DVD, Blu-ray which records and reproduces information at a shorter wavelength than that used in CD (λ = 780 nm) and DVD (λ = 635, 650 nm). Development of new media such as ray discs and information devices for reading and writing information on these media is underway.

  However, in so-called next-generation DVDs such as Blu-ray Discs, light having a wavelength of around 400 nm is used for recording and reproducing information, so that an optical element composed of a thermoplastic resin described in Patent Document 1 is short. Under the influence of light irradiation of the wavelength and the heat accompanying it, there is a problem that it itself becomes cloudy or the optical surface is deformed, resulting in poor durability against light and heat.

On the other hand, silicone resins are known as resins that are highly transparent and have optically superior properties and are also said to have excellent durability against light. For example, contact lenses having oxygen permeability and Rubber-like polydimethylsiloxane has been applied to special uses such as variable focus lenses, but these have been difficult to apply to general optical elements such as lenses and prisms that require mechanical strength. On the other hand, in recent years, an optical element using a silicone-based optical resin having a ladder-type silsesquioxane skeleton has been proposed (for example, see Patent Document 2). However, the silicone-based optical resin having a ladder-type silsesquioxane skeleton proposed in Patent Document 2 is still insufficient in heat resistance to be applied to the optical element using light of around 400 nm as described above. However, at present, a plastic optical element material satisfying high heat resistance as well as durability against light has not yet been obtained.
JP 2002-105131 A JP 2004-354547 A

  The present invention has been made in view of the above problems, and its purpose is to improve the light stability, to have excellent transparency, and to maintain the characteristics for a long time, and to use this plastic optical element material. It is an object of the present invention to provide a plastic optical element (hereinafter also simply referred to as an optical element) and an optical pickup device using the plastic optical element having good pickup characteristics.

  The above object of the present invention is achieved by the following configurations.

  1. A plastic optical element material, which is a resin composition containing an oligosiloxane-modified norbornene resin represented by the following general formula (1).

Wherein R ^{1 to} R ¹⁸ are each a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 10 carbon atoms, a cyano group, an amide Represents a group or an imide group and may be the same or different. R ¹⁷ and R ¹⁸ may be bonded to each other to form a monocyclic or polycyclic ring structure. R ¹⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R ²⁰ represents a single bond or a divalent organic group, and A represents an oligosiloxane group. a represents an integer of 0 to 2, and n represents an integer of 10 to 1,000,000. ]
2. The oligosiloxane group (A) of the oligosiloxane-modified norbornene resin represented by the general formula (1) is represented by the T ⁿ structural unit represented by the following general formula (2) and the following general formula (3). 2. The plastic optical element material as described in 1 above, which is a group represented by the following general formula (4) containing a ^Dm structural unit.

General formula (2)
D ^m structural _{^{units: R 26 Si (OH) 3}} -n O n / 2
General formula (3)
T ⁿ structural _{^{units: R 27 Si (OH) 2}} -m O m / 2
[Wherein, n represents an integer of 1 to 3, and m represents 1 or 2. R ²⁶ and R ²⁷ each represents a hydrogen atom or a substituent. ]
General formula (4)
_{^{- (T 3 p T l q}} D o r)
[In the formula, T represents that the number of Si siloxane bonds represented by the general formula (3) is 3, and D represents the number of Si siloxane bonds represented by the general formula (2) is 2. It represents that. l represents 1 or 2, o represents 1 or 2, p represents an integer of 4 to 20, q and r each represents an integer of 0 to 20, and p + q + r ≧ 6. ]
3. 3. The resin composition according to 1 or 2 above, wherein the resin composition comprises a polymer obtained by polymerizing an inorganic fine particle having a reactive group and a polyfunctional compound having two or more reactive groups. Plastic optical element material.

  4). The inorganic fine particles having a reactive group are inorganic oxides and have at least one reactive group selected from a vinyl group, a (meth) acryloyl group, an epoxy group, an oxetanyl group, and a mercapto group. 4. The plastic optical element material as described in 3 above.

  5. 5. A plastic optical element using the plastic optical element material according to any one of 1 to 4 above, wherein a fine structure is provided on an optical surface.

  6). 6. The plastic optical element as described in 5 above, wherein the light transmittance at a wavelength of 400 nm of a molded article having a thickness of 3 mm molded using the plastic optical element material is 85% or more.

  7. 7. The plastic optical element as described in 5 or 6 above, which is used in a light collecting device having a light collecting function.

  8). An optical pickup device that performs either reproduction or recording of information on an optical information recording medium, the light source emitting light, the irradiation of the light emitted from the light source to the optical information recording medium, and the optical information And an optical element unit that collects light reflected by the recording medium, and the optical element unit includes the plastic optical element described in any one of 5 to 7 above. Optical pickup device.

  9. 9. The optical pickup device as described in 8 above, wherein the light source emits light having a wavelength of 390 to 420 nm.

  By the above-mentioned means of the present invention, a plastic optical element material, a plastic optical element using the same, and a plastic optical element that can improve the light stability, have excellent transparency, and maintain the characteristics for a long time, and the same It was possible to provide an optical pickup device having good pickup characteristics using the.

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

  The plastic optical element material of the present invention is a resin composition containing an oligosiloxane-modified norbornene resin represented by the general formula (1). This feature is a technical feature common to the inventions according to claims 1 to 9.

  The plastic optical element material applied to the optical element in each of the inventions according to claims 1 to 4 is at least a resin composition containing at least one oligosiloxane-modified norbornene resin, or at least inorganic fine particles having a reactive group. It is characterized by being a resin composition containing a polymer obtained by polymerizing at least one of one kind and a polyfunctional compound.

  Although norbornene-based resins are resins having high transparency and excellent optical properties, in recent years, with the advancement of functions of optical devices, higher physical properties for optical elements and higher reliability have been demanded. In particular, environmental fluctuations in optical characteristics are a major issue, and improvements in physical properties such as reduction in linear expansion coefficient and improvement in heat resistance are required.

  In contrast, an optical element manufactured by using a resin composition containing a thermoplastic resin obtained by modifying a norbornene-based resin introduced with a thioacetal structure with an oligosiloxane group by examining various ring structures bonded to the norbornene skeleton, It has a high light transmittance and a high stabilization effect against light irradiation. For example, even when continuously irradiated with light having a short wavelength of about 400 nm, white turbidity and change in refractive index can be suppressed. It was found that the deformation of the optical surface under the high temperature environment before and after can be suppressed for a long time. That is, it has been found that the optical stability and thermal stability of the optical element can be improved, and an element capable of maintaining the characteristics for a long time can be manufactured. Further, a resin comprising a polymer obtained by subjecting the resin composition to a polymerization reaction of at least one kind of inorganic fine particles having a reactive group and at least one kind of a polyfunctional compound having two or more reactive groups. By using the composition, a more stable device can be produced.

  According to the fifth aspect of the present invention, at least one optical surface is provided with a fine structure, and this optical element uses the plastic optical element material according to any one of the first to fourth aspects. Therefore, it has high shape stability with respect to environmental fluctuations such as light and heat, and can appropriately suppress the deformation of the fine structure.

  According to the sixth aspect of the present invention, a molded body having a thickness of 3 mm molded using the plastic optical element material of the present invention has high shape stability and transmits light having a wavelength of about 400 nm with high energy. Even if it makes it, it can suppress that the clouding, the fluctuation | variation of a refractive index, a deformation | transformation, etc. arise in the said molded object. Thereby, the light transmittance in the vicinity of a wavelength of 400 nm can be 85% or more. Therefore, for example, it can be suitably used as an optical element for an optical information recording medium having a high information density such as Blu-ray Disc.

  According to the seventh aspect of the present invention, even if an optical element is used in a condensing device having a condensing function, the optical element has high shape stability, so that the optical characteristics of the optical element are deteriorated. Such a thing disappears. In other words, even when high energy is applied to the optical element by focusing, the high shape stability of the optical element makes it possible to suppress deformation of the optical element over a long period of time. It is possible to prevent deterioration of characteristics.

  According to the eighth aspect of the present invention, the resin composition containing the oligosiloxane-modified norbornene resin, the inorganic fine particles having a reactive group, and the polyfunctional compound are contained in the resin composition, and these are polymerized. Since the optical element is manufactured using the plastic optical element material of the present invention, which is a resin composition containing a polymer to be produced, it has a high stabilizing effect against light irradiation, for example, irradiation with light having a short wavelength around 400 nm. Even if it is continuously received, the cloudiness and refractive index fluctuation can be suppressed.

  Further, for example, the deformation of the optical surface in a high temperature environment of around 85 ° C. can be suppressed for a long time. That is, the light 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 / 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. You can get something expensive.

  According to invention of Claim 9, the wavelength of the light radiate | emitted from a light source is 390-420 nm. That is, for example, even when transmitting light in the range of 390 to 420 nm corresponding to an optical information recording medium having a high information density such as Blu-ray Disc, the resin composition applied to the optical element in the present invention is Optical element such as white turbidity and change in refractive index because it is a resin composition containing an oligosiloxane-modified norbornene resin, or a polymer obtained by copolymerizing inorganic fine particles having a reactive group and a polyfunctional compound. Can be prevented. Thereby, the lifetime of the optical element can be extended, and a highly reliable optical pickup device can be obtained.

  The plastic optical element material applied to the plastic optical element of the present invention is a polymer obtained by copolymerizing an oligosiloxane-modified norbornene resin, or inorganic fine particles having a reactive group, or a polyfunctional compound. It is the resin composition containing. In general, optical materials made of plastic have a larger coefficient of thermal expansion than inorganic materials such as glass and ceramics, so that the change in the shape of the element becomes a big problem in applications used in a high temperature environment.

  On the other hand, as a result of intensive studies to solve the above problems, the present inventors have used the above-described plastic optical element material of the present invention, so that, for example, the optical surface can be deformed even in a high temperature environment of around 85 ° C. It was found that it can be suppressed for a long time. Furthermore, for example, it has high stabilization effect against light irradiation, such as maintaining transparency and suppressing white turbidity and refractive index fluctuations even when continuously irradiated with light having a short wavelength of around 400 nm. It has been found that an element capable of improving the properties and light stability and capable of maintaining the characteristics for a long time can be manufactured.

  Hereinafter, the present invention and its components will be described in more detail.

<Oligosiloxane modified norbornene resin>
The oligosiloxane-modified norbornene resin according to the present invention comprises a norbornene monomer having a thioacetal structure represented by the following general formula (5) and an oligosiloxane compound having a vinyl group represented by the following general formula (6). It is obtained by subjecting the mixture to ring-opening metathesis polymerization and then converting the carbon-carbon double bond in the molecular chain to a single bond.

In the general formula (5), R ^{1 to} R ¹⁸ are each a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 10 carbon atoms, It represents a cyano group, an amide group or an imide group and may be the same or different. R ¹⁷ and R ¹⁸ may be bonded to each other to form a monocyclic or polycyclic ring structure.

General formula (6)
_{^{CH 2 = CR 23 (R 24}} ) - (T 3 p T l q D o r)
In the general formula _{^{(6), T 3 p T}} l q D o r structure from D ^m structural unit represented by T ⁿ and a structural unit represented by the following general formula represented by the following general formula (2) (3) In the group
General formula (2)
R ²⁶ Si (OH) _3-n O _{n / 2}
General formula (3)
R ²⁷ Si (OH) _2-m O _{m / 2}
In the general formulas (2) and (3), n represents an integer of 1 to 3, and m represents 1 or 2. R ²⁶ and R ²⁷ each represent a hydrogen atom or a substituent.

R ²³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R ²⁴ is a single bond or a divalent organic group, l is 1 or 2, o is an integer of 1 or 2, and p is The integer of 4-20, q, r represents the integer of 0-20.

The oligosiloxane group is also called a T-resin, and is a compound represented by (RSiO _3/2 ), whereas ordinary silica is represented by the formula (SiO ₂ ), usually tetraethoxysilane. Polysiloxane synthesized by hydrolysis-polycondensation of (RSi (OR ′) ₃ ) compound in which one alkoxy group of tetraalkoxysilane (Si (OR ′) ₄ ) represented by formula (1) is replaced with an alkyl group or an aryl group As the shape of the molecular arrangement, an amorphous shape, a ladder shape, and a cage shape (condensed cage shape) are known. Specifically, the type represented by the chemical formula of T ³ ₈ : (RSiO _3/2 ) ₈ ((4) -1), the type represented by the chemical formula of T ³ ₁₀ : (RSiO _3/2 ) ₁₀ (( 4) -2), a type represented by a chemical formula of T ³ ₁₂ : (RSiO _3/2 ) ₁₂ ((4) -3), a type represented by a chemical formula of T ³ ₁₄ : (RSiO _3/2 ) ₁₄ Types ((4) -6, (4) -7) represented by the chemical formulas of ((4) -4, (4) -5) and T ³ ₁₆ : (RSiO _3/2 ) ₁₆ are known. Yes. These are represented by n = 3 in the general formula (2), that is, composed of only the T ³ structure. The structure of each oligosiloxane group represented by (4) -1 to (4) -7 is shown below.

These are called complete condensation cages. In addition, in general formula (4), a type called incomplete condensation cage in which q ≠ 0 or r ≠ 0 is also known. These types of compounds can also be used. Specific examples of the type called incomplete condensation cage include a type represented by T ³ ₆ T ² ₂ ((4) -8) and a type represented by T ³ ₆ T ² D ² ((4) -9. ) And T ³ ₆ D ² ₂ ((4) -10).

T ³ for ₆ T ² ₂ consists n = ie T ² structure represented by 2 are two and in the general formula (2) T ³ structure 6 in the general formula (2), T ³ ₆ T ² D ² is composed of 6 T ³ structures, 1 T ² structure, and m = 2 in the general formula (3), that is, 1 D ² structure. For T ³ ₆ D ² ₂ , the T ³ structure consists of 6 pieces and the D ² structure 2 pieces.

  The structure of each oligosiloxane group represented by (4) -8 to (4) -10 is shown below.

In the general formula (6) representing the oligosiloxane compound according to the present invention, the substituents represented by R ²⁶ and R ²⁷ in the general formula (2) and the general formula (3) representing the structural unit are as follows: Hydrogen atom, methyl group, ethyl group, cyclopentyl group, cyclohexyl group, isopropyl group, 2-ethylhexyl group, t-butyl group, 2-chloroethyl group, methacryloxypropyl group, allyl group, 3-aminopropyl group, 3- An alkyl group such as a mercaptopropyl group or a 3-glycidoxypropyl group, or an aromatic group such as an aryl group such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, or a phenanthryl group is represented. These oligosiloxane compounds may be used in combination of two or more.

The metathesis polymerization catalyst used in the present invention is not particularly limited as long as the norbornene-based monomer can be subjected to metathesis ring-opening polymerization. Examples of the metathesis polymerization catalyst include a group 4-8 transition metal carbene complex catalyst in the periodic table, and a ring-opening metathesis polymerization catalyst using a combination of a transition metal compound and an alkylating agent or a Lewis acid as a promoter. Among these, since the catalytic activity is high, it is preferable to use a group 4-8 transition metal carbene complex catalyst of the periodic table, and it is particularly preferable to use a ruthenium carbene complex catalyst. On the other hand, as the transition metal compound in the catalyst by the combination of the transition metal compound and the alkyl agent or Lewis acid, for example, MoCl ₄ , MoBr ₂ , MoBr ₃ , MoBr ₄ , WCl ₂ , WBr ₂ , WCl ₄ , WBr ₄ , WCl ₄ , WCl ₅ , WBr _{5 and the} like, and examples of the co-catalyst include methyl lithium, ethyl lithium, n-butyl lithium methyl magnesium chloride, methyl magnesium bromide and the like, and Lewis acids include trimethyl aluminum, triethyl aluminum, Examples include triisopropylaluminum, tetramethyltin, tetraethyltin, and tetrabutyltin. The amount of the ring-opening metathesis polymerization catalyst used is preferably 0.1 to 0.0000001 mol, more preferably 0.01 to 0.0000005 mol with respect to 1 mol of the norbornene-based monomer, from the viewpoint of ease of catalyst removal and polymerization activity. The amount is particularly preferably 0.001 to 0.000001 mol.

  Hydrogenation of a carbon-carbon double bond in a norbornene-based ring-opening metathesis polymer modified with oligosiloxane into a single bond is carried out by hydrogenation using hydrogen gas in the presence of a hydrogenation catalyst. Is called. The catalyst used for the hydrogenation reaction is not particularly limited, such as a heterogeneous catalyst or a homogeneous catalyst, and a catalyst generally used for a hydrogenation reaction of an olefin compound can be used. Examples of the heterogeneous catalyst include catalysts in which metals such as palladium, platinum, rhodium, ruthenium, and nickel are supported on activated carbon, silica, alumina, and the like. Specifically, palladium / activated carbon, palladium / silica, palladium / Alumina, platinum / activated carbon, platinum / alumina, rhodium / activated carbon, ruthenium / activated carbon, nickel / silica and the like can be mentioned. Examples of the homogeneous catalyst include dichlorotris (triphenylphosphine) rhodium, the ruthenium carbene complex described as the catalyst used for the ring-opening metathesis polymerization, a ruthenium complex catalyst, and the like. Among these, it is preferable to use a palladium-supported catalyst such as a rhodium complex catalyst, a ruthenium complex catalyst, and palladium / activated carbon because a carbon-carbon double bond can be selectively hydrogenated.

<< Inorganic fine particles with reactive groups >>
Examples of the inorganic fine particles used in the present invention include inorganic oxide fine particles. Specifically, for example, titanium oxide, zinc oxide, aluminum oxide, zirconium oxide, hafnium oxide, niobium oxide, tantalum oxide, magnesium oxide, oxide Calcium, strontium oxide, barium oxide, yttrium oxide, lanthanum oxide, cerium oxide, indium oxide, tin oxide, lead oxide, complex oxides composed of these oxides such as lithium niobate, potassium niobate, lithium tantalate, etc. And phosphates and sulfates formed in combination with these oxides.

  Since these inorganic fine particles exist in a state of being dispersed in the resin, when a plastic optical element material containing the inorganic fine particles is applied to an optical element, the average particle diameter is preferably 1 nm or more and 50 nm or less in order to ensure transparency. . More preferably, it is 1 nm or more and 30 nm or less, or more preferably 1 nm or more and 20 nm or less, and most preferably 1 nm or more and 10 nm or less. If the average particle size is 1 nm or more, the desired performance can be easily obtained because the dispersion of inorganic fine particles is easy at the time of production, and if the average particle size is 50 nm or less, the resulting plastic optical element material becomes cloudy. Transparency is maintained, and the light transmittance is 70% or more. The average particle diameter here is defined as the diameter when converted to a sphere having the same volume as the particles.

  The shape of the inorganic fine particles is not particularly limited, but preferably spherical fine particles are used. Further, the particle size distribution is not particularly limited, but those having a relatively narrow distribution than those having a wide distribution are preferably used.

  The inorganic fine particles used in the present invention are prepared by mixing a silane coupling agent having a reactive group such as a vinyl group, a (meth) acryloyl group, an epoxy group, an oxetanyl group, a mercapto group and the inorganic fine particles, and hydrolyzing them. Inorganic fine particles in which a reactive group is introduced by bonding both, reacting and curing in a mixed composition of this and a polyfunctional compound, and by dispersing uniformly in the resin, the transparency of the cured resin is improved. Can be secured.

  Examples of the silane coupling agent used include vinyltriacetoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and γ-glycid. Examples include xylpropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropylmethyldimethoxysilane. These inorganic fine particles may be used in combination of plural kinds.

《Polyfunctional compound》
The polyfunctional compound used in the present invention is a compound having two or more reactive groups such as vinyl group, (meth) acryloyl group, epoxy group, oxetanyl group, mercapto group, etc. It reacts with sun and inorganic fine particles having a reactive group to form a crosslinked structure in the resin.

  For example, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, tetraethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate having two or more (meth) acryloyl groups as polyfunctional (meth) acrylate Methacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate and the like are polyfunctional epoxy compounds, glycidyl ether type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, resorcinol diglycidyl ether, diglycidyl phthalate, and Dimer acid diglycidyl ester, triglycidyl ether trif Nylmethane, tetraglycidyl ether tetraphenyl ethane, bisphenol S diglycidyl ether, cresol novolac glycidyl ether, triglycidyl isocyanurate, tetrabromobisphenol A diglycidyl ether, etc., as polyfunctional oxetane compounds, reaction of polyfunctional phenol compounds and oxetane chloride Products, for example, bifunctional oxetane compounds such as bisphenol A type, bisphenol F type, bisphenol S type, biphenyl type and cardo type, trifunctional oxetane compounds such as trisphenol methane type and triskresol methane type, phenol novolac type, cresol Examples thereof include polyfunctional oxetane compounds such as novolak type and calixarene type. These polyfunctional compounds may be used in combination of two or more.

<Stabilizer>
In the plastic optical element material of the present invention, one or more stabilizers selected from hindered amine stabilizers, phenol stabilizers, phosphorus stabilizers and sulfur stabilizers may be additionally added. By appropriately selecting these stabilizers and adding them to the plastic optical element material, for example, the white turbidity when continuously irradiating light with a short wavelength such as 400 nm, and the optical characteristic fluctuations such as the refractive index fluctuations can be enhanced. Can be suppressed.

  As a preferable phenol-based stabilizer, conventionally known ones can be used, 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′-methylenebis (4-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-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 pentaerythritol tetrakis (3 Alkyl substitution such as-(3,5-di-t-butyl-4-hydroxyphenylpropionate)), triethylene glycol bis (3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate) Phenolic compounds; 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3,5- Triazines such as triazine, 2-octylthio-4,6-bis (3,5-di-t-butyl-4-oxyanilino) -1,3,5-triazine Azine group-containing phenolic compounds; and the like.

  Preferred hindered amine stabilizers include, for example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (N-octoxy-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-tert-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1-acryloyl-2) 2,6,6-tetramethyl-4-piperidyl) 2,2-bis (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1,2,2,6 , 6-pentamethyl-4-piperidyl) decanedioate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4- [3- (3,5-di-t-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-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide and the like.

Further, the preferable phosphorus stabilizer 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 (nonyl) Phenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9 Monophosphite compounds such as 1,4-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4'-butylidenebis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite ), 4,4'-isopropylidene-bis (phenyl - di - alkyl (C ₁₂ -C ₁₅₎ phospha G) diphosphite compounds such as 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.

  Further, preferable sulfur stabilizers include, for example, dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3- Thiodipropionate, pentaerythritol-tetrakis (β-laurylthio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, etc. It is done.

  Although the compounding quantity of these stabilizers is suitably selected in the range which does not impair the objective of this invention, it is 0.01-2 mass parts normally with respect to 100 mass parts of resin compositions, Preferably it is 0.01-1 mass. Part.

<Surfactant>
A surfactant is a compound having a hydrophilic group and a hydrophobic group in the same molecule. The surfactant has an effect of preventing white turbidity of the plastic optical element material by adjusting the rate of moisture adhesion to the resin surface and the evaporation rate of moisture from the surface.

  Specific examples of the hydrophilic group of the surfactant include a hydroxy group, a hydroxyalkyl group having 1 or more carbon atoms, a hydroxyl group, a carbonyl group, an ester group, an amino group, an amide group, an ammonium salt, a thiol, a sulfonate, A phosphate, a polyalkylene glycol group, etc. are mentioned. Here, the amino group may be primary, secondary, or tertiary. Specific examples of the hydrophobic group of the surfactant include an alkyl group having 6 or more carbon atoms, a silyl group having an alkyl group having 6 or more carbon atoms, and a fluoroalkyl group having 6 or more carbon atoms. Here, the alkyl group having 6 or more carbon atoms may have an aromatic ring as a substituent. Specific examples of the alkyl group include hexyl, heptyl, octyl, nonyl, decyl, undecenyl, dodecyl, tridecyl, tetradecyl, myristyl, stearyl, lauryl, palmityl, cyclohexyl and the like. Examples of the aromatic ring include a phenyl group. This surfactant only needs to have at least one hydrophilic group and one hydrophobic group as described above in the same molecule, and may have two or more groups.

  More specifically, examples of such surfactants include myristyl diethanolamine, 2-hydroxyethyl-2-hydroxydodecylamine, 2-hydroxyethyl-2-hydroxytridecylamine, 2-hydroxyethyl-2- Hydroxytetradecylamine, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, di-2-hydroxyethyl-2-hydroxydodecylamine, alkyl (8-18 carbon atoms) benzyldimethylammonium chloride, ethylene Examples thereof include bisalkyl (carbon number 8 to 18) amide, stearyl diethanolamide, lauryl diethanolamide, myristyl diethanolamide, palmityl diethanolamide, and the like. Among these, amine compounds or amide compounds having a hydroxyalkyl group are preferably used. In the present invention, two or more of these compounds may be used in combination.

  The surfactant is added in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the plastic optical element material. If the addition amount of the surfactant is 0.01 parts by mass or more, white turbidity of the molded product due to temperature and humidity fluctuations can be effectively suppressed. On the other hand, if the addition amount is 10 parts by mass or less, the light transmittance of the molded product can be maintained, and it can be applied to an optical pickup device. The addition amount of the surfactant is preferably 0.05 to 5 parts by mass, and more preferably 0.3 to 3 parts by mass with respect to 100 parts by mass of the resin composition.

<< Curing and molding method for plastic optical element material >>
When the resin composition according to the present invention includes a polymer obtained by copolymerizing inorganic fine particles having a reactive group and a polyfunctional compound, these can be obtained by either ultraviolet or electron beam irradiation or heat treatment. It can be cured, and the oligosiloxane-modified norbornene-based resin, inorganic fine particles having reactive groups, and polyfunctional compounds are mixed in an uncured state, and if necessary, stabilizers, surfactants, etc. It is obtained by preparing a resin composition to which an additive has been added and then curing it. The content of the oligosiloxane-modified norbornene resin is preferably 10 to 90 parts by mass, more preferably 20 to 70 parts by mass with respect to 100 parts by mass of the resin composition. The addition amount of the inorganic fine particles is preferably 5 to 70 parts by mass, more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the resin composition. The addition amount of the polyfunctional compound is preferably 5 to 80 parts by mass and more preferably 10 to 60 parts by mass with respect to 100 parts by mass of the resin composition.

  In preparing the resin composition before curing, conventionally known methods can be employed. For example, when the properties of the resin composition to be prepared are liquid, a predetermined amount of each component is blended. It can be dissolved and mixed later, or mixed uniformly with a mixer, blender, etc. and then heat-kneaded with a kneader or roll to obtain a liquid curable resin composition, and the properties of the prepared resin composition are In the case of a solid state, each component is mixed and dissolved and mixed, or after being uniformly mixed with a mixer, a blender, etc. and then heated and kneaded with a kneader or a roll, cooled and solidified, and then pulverized into a solid state The resin composition can be obtained.

  As a method for curing the resin composition, when the resin composition is ultraviolet ray and electron beam curable, a resin composition with a photopolymerization initiator added as necessary to a light-transmitting mold having a predetermined shape is filled. Alternatively, after coating on the substrate, it may be cured by irradiation with ultraviolet rays and electron beams.

  Examples of the photopolymerization initiator used here include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, tri Phenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4- Photoradical initiation such as isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one Etc. The.

  On the other hand, if the resin composition is thermosetting, after preparing a resin composition to which a thermal polymerization initiator such as a thermal radical generator is added, if necessary, thermosetting molding by compression molding, transfer molding, injection molding, etc. can do. Examples of the thermal polymerization initiator used here include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4- Azo compounds such as methoxy-2,4-dimethylvaleronitrile), organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis (t-butylperoxy) cyclohexane, etc. It is done.

<Optical pickup device>
A preferred aspect of the optical pickup device of the present invention is an optical pickup device that performs either reproduction or recording of information on an optical information recording medium, the light source emitting light, and the light emitted from the light source. An optical element unit for either irradiating the optical information recording medium or collecting the light reflected by the optical information recording medium, and the optical element unit includes the plastic optical element of the present invention. It is characterized by. As will be described later, the plastic optical element of the present invention is preferably used in a lens having a light collecting function or a light collecting device. In a preferred embodiment, the light source is a light source that emits light having a wavelength of 390 to 420 nm.

  Next, the plastic optical element and the optical pickup device of the present invention will be described with reference to FIGS.

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

  The optical pickup device 1 allows laser light (light) emitted from a light source 2 to pass through a single lens optical element such as a collimator lens 3 and an objective lens (plastic optical element) 10 having a fine structure which will be described later. The collected light spot is formed on the information recording surface 6 of the optical information recording medium 5 above, the reflected light from the information recording surface 6 is captured by the deflecting beam splitter 7, and the beam spot is formed again on the light receiving surface of the detector 8. To do.

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

  The collimator lens 3, the objective lens (plastic optical element) 10, and the deflection beam splitter 7 constitute an optical element unit.

  The objective lens 10 according to the present invention is an optical element having a fine structure, and is produced by molding a resin composition by injection molding. As shown in FIG. 2, the objective lens 10 is a single-sided optical element having a double-sided aspheric surface, and is predetermined for predetermined light passing through the optical surface 11 on one (light source side) optical surface 11 thereof. The optical path difference providing structure 20 (fine structure) for providing the optical path difference is provided.

  The optical path difference providing structure 20 includes three annular lens surfaces whose optical surfaces 11 are centered on the optical axis 4 (hereinafter, a first annular lens surface 21, a second annular lens surface 22, and a third annular zone in order from the inside). The annular lens surfaces 21 to 23 adjacent to each other among the three annular lens surfaces 21 to 23 have different refractive powers.

  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.

  The first annular lens surface 21 transmits light having both wavelengths of 650 nm and 405 nm, the second annular lens surface 22 transmits light having a wavelength of 650 nm corresponding to the current DVD, and the third annular lens surface 23 The light of wavelength 405nm corresponding to next-generation DVD is allowed to pass through. The light that has passed through each of the annular lens surfaces 21 to 23 is collected at the same position on the information recording surface 6.

  In FIG. 2, the first annular lens surface 21 and the third annular lens surface 23 are provided on the same optical surface 11, but the first and third annular lens surfaces 21 and 23 are different from each other. The second annular lens surface 22 does not have to be provided on the same optical surface, and the second annular lens surface 22 is a surface translated from the optical surface 11. Further, the three annular lens surfaces 21 to 23 may be five, or at least three or more.

  By the action of the optical path difference providing structure 20 formed in this way, the objective lens 10 collects the light emitted from the light source 2 on the information recording surface 6 with respect to a plurality of types of optical information recording media 5 such as the current DVD and the next generation DVD. Condensing light and light reflected by the information recording surface 6 toward the detector 8 can be performed with high reliability. Moreover, since the resin composition that forms the objective lens 10 has a high light transmittance of 85% or more, the above-described light collection can be performed with high efficiency. Therefore, since the power consumption of the light source 2 can be reduced, the power consumption of the entire optical pickup device 1 can be reduced.

  The objective lens 10 according to the present invention is not limited to the one having the optical path difference providing structure 20 described above, and may be, for example, objective lenses 10a to 10e having optical path difference providing structures 20a to 20d shown in FIGS. .

  The optical path difference providing structure 20a in FIG. 3 includes a plurality of diffraction ring zones 21a with the optical axis 4 as the center, the plurality of diffraction ring zones 21a have a sawtooth cross section, and the optical surface 11a of each diffraction ring zone 21a. Is a discontinuous surface. Further, the plurality of diffraction ring zones 21 a are formed so that the thickness increases as the distance from the optical axis 4 increases. The objective lens 10a shown in FIG. 3 is a so-called diffractive lens.

  The optical path difference providing structure 20b in FIG. 4 has a plurality of annular zone-shaped 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 five surfaces of the optical surface 11b centered on the optical axis 4 (upper and lower optical surfaces centering on the optical axis 4 in FIG. 4). Adjacent ring-shaped recesses 21b are continuously integrated with each other, and the entire cross-section of each ring-shaped recess 21b is stepped. Moreover, the optical surface 22b which forms each annular zone-shaped recessed part 21b is a surface translated with respect to the optical surface 11b. The objective lens 10b shown in FIG. 4 is a so-called phase difference lens.

  In FIG. 4, the adjacent ring-shaped recesses 21b are continuous and integrated, and the entire cross section is stepped. However, the ring-shaped recesses 21b are simply provided on the optical surface 11b. It is good also as a thing (In this case, it becomes a structure similar to the objective lens 10 shown, for example in FIG. 2). In FIG. 4, the annular concave portion 21b is concentrically formed. However, as shown in FIG. 5, the objective lens having the annular convex portion 23b on the third annular lens surface 23 of FIG. 10c may be used (in FIG. 5, the same components as those in FIG. 2 are given the same reference numerals).

  The optical path difference providing structure 20d in FIG. 6 includes 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 the optical surface 11d of each diffraction ring zone 21d. Is a discontinuous surface. The cross section of each diffraction ring zone 21d is a stepped shape of three steps 22d along the optical axis direction, and the optical surface 12d of each step 22d is a discontinuous surface and is a surface orthogonal to the optical axis 4. Yes.

  The lens 10d shown in FIG. 6 may have, for example, a hologram optical element (HOE) 10e having an optical path difference providing structure 20d similar to that shown in FIG. 6 and an objective lens 10f as shown in FIG. . In this case, the hologram optical element 10e uses a flat optical element, and the optical path difference providing structure 20d is provided on the surface of the objective lens 10f of the optical element.

  Note that the optical pickup device 1 may reproduce and record information on three types of optical information recording media 5, for example, 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.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<Manufacture of norbornene resin>
[Production Example 1]
A norbornene derivative A having a thioacetal structure shown below was obtained according to the production method described in JP-A 2007-9178.

  According to the production method described in Japanese Patent Application Laid-Open No. 2006-298957 etc., the norbornene derivative A obtained above and cage-like silsesquioxane (Methacryl-Isobutyl-POSS, Sigma-Aldrich) as oligosiloxane were opened. After ring metathesis polymerization, a hydrogenation reaction was performed to obtain oligosiloxane-modified norbornene resin A.

[Production Example 2]
An oligosiloxane-modified norbornene resin B was obtained in the same manner as in Production Example 1 except that 2-norbornene was used in place of the norbornene derivative A.

<< Preparation of inorganic fine particles >>
[Production Example 3]
To 3 L of an aqueous solution containing 0.027 mol of disodium hydrogen phosphate, 2 L of each of 3.53 mol% of aluminum sulfate aqueous solution and 7.06 mol% of disodium hydrogen phosphate aqueous solution were added by double jet method. Added over a minute. During the fine particle formation, the pH was controlled to 3.0 using sulfuric acid, and the temperature was controlled to 30 ° C. After the addition, soluble salts were desalted and removed by ultrafiltration to obtain a 10% by mass aluminum phosphate dispersion. To 100 parts by mass of this dispersion, 300 parts by mass of methanol and a 1 mol% nitric acid aqueous solution were added. While stirring this solution at 50 ° C., a mixed solution of 100 parts by mass of methanol and 6 parts by mass of γ-methacryloxypropyltrimethoxysilane was added over 60 minutes, and then the mixture was further stirred for 2 hours. The obtained transparent dispersion was suspended in ethyl acetate and centrifuged to obtain a white fine powder. According to TEM observation, this powder had an average particle size of about 20 nm. This was designated as inorganic fine particles A.

[Production Example 4]
To 5 parts by mass of aluminum oxide C (average particle size: about 13 nm) fine particles manufactured by Nippon Aerosil Co., 300 parts by mass of methanol and a 1 mol% nitric acid aqueous solution were added. While stirring this solution at 50 ° C., a mixed solution of 100 parts by mass of methanol and 6 parts by mass of γ-methacryloxypropyltrimethoxysilane was added over 60 minutes, and then the mixture was further stirred for 2 hours. The obtained transparent dispersion was suspended in ethyl acetate and centrifuged to obtain a white fine powder. According to TEM observation, this powder had an average particle size of about 15 nm. This was designated as inorganic fine particles B.

<< Preparation of thermosetting resin composition >>
[Preparation of Thermosetting Resin Compositions 1-3 (Invention), 4-6 (Comparative Example)]
According to the blend composition of each additive listed in Table 1, the additives were mixed and then kneaded using a kneader to obtain uniform thermosetting resin compositions 1-6. Each of the obtained thermosetting resin compositions was filled in a mold having dimensions of 30 mm × 30 mm × 3 mm, and then heated and pressed at 220 ° C. for 20 minutes to obtain plate-like plastic optical elements 1 to 6. .

  In Table 1, details of each component other than the inorganic fine particles are as follows. Moreover, the numerical value of Table 1 represents a mass part.

Polyfunctional compound A: Pentaerythritol tetraacrylate Multifunctional compound B: Trimethylolpropane trimethacrylate Polymerization initiator: Azobisisobutyronitrile Stabilizer A: Tetrakis (1,2,2,6,6-pentamethylpiperidyl ) Butanetetracarboxylate Stabilizer B: 2,2'-Methylenebis (4,6-di-t-butylphenyl) -2-ethylhexyl phosphite Surfactant: Pentaerythritol distearate.

<< Evaluation of plastic optical elements >>
Next, with respect to the obtained plastic optical elements 1 to 6, each optical characteristic evaluation was performed according to the following method, and the obtained results are shown in Table 2.

(Colorability and transparency evaluation)
About each said plastic optical element, the light transmittance by wavelength 400nm was measured, the color tone through the transmitted light was visually observed, and coloring property and transparency were evaluated. As a result, each optical element made of plastic had a light transmittance of 86% or more and a high transmittance.

(Evaluation of light durability)
In a constant temperature and humidity chamber of 90 ° C. and 55% RH, the optical pickup device shown in FIG. 1 is used, and light having a wavelength of 405 nm is emitted from the laser diode of the light source 2 onto each plastic optical element. As follows, after continuous irradiation for 1500 hours, the laser irradiation spot was visually observed, and transparency (coloring degree) and shape stability due to white turbidity were evaluated according to the following criteria.

<Evaluation of coloring>
○: Slight turbidity is observed at the laser irradiation location after continuous irradiation. Δ: Turbidity is observed at the laser irradiation location after continuous irradiation. ×: White turbidity is observed at the laser irradiation location after continuous irradiation. It is within the allowable range.

<Evaluation of shape stability>
◎: After the continuous irradiation, no deformation of the laser irradiated portion is observed. ○: After the continuous irradiation, the laser irradiated portion is slightly deformed. Δ: After the continuous irradiation, the laser irradiated portion is slightly deformed. After irradiation, deformation is observed at the laser irradiation point. If it is Δ or more, it is practically acceptable.

  As is clear from the results shown in Table 2, the plastic optical element of the present invention molded using the resin composition according to the present invention is obtained by continuously irradiating light of a short wavelength for a long time with respect to the comparative example. No coloration or white turbidity occurred, and no deformation occurred, and high shape stability could be maintained.

Example 2
<Production of optical pickup device>
An optical element (objective lens) having the same composition as the plastic optical elements 1 to 6 described in Example 1 and the structure illustrated in FIGS. 2 to 7 is manufactured by injection molding, and the structure illustrated in FIG. Thus, the optical pickup devices 1 to 3 of the present invention and the optical pickup devices 4 to 6 of the comparative example were produced. Next, using each optical pickup device, recording and reproduction on a DVD were performed using light of a wavelength of 405 nm by a laser diode.

<Evaluation of optical pickup device>
The optical pickup devices 1 to 3 manufactured using the plastic optical elements 1 to 3 of the present invention showed good pickup characteristics with no deformation or the like even after continuous irradiation for a long time.

  On the other hand, the optical pickup devices 4 to 6 manufactured using the plastic optical elements 4 to 6 of the comparative example are deformed as the structure of the optical surface is made finer (complex), and the pickup characteristics are increased. Decrease was observed.

The side view which shows the outline of the optical pick-up apparatus 1 which concerns on this invention Sectional view of the objective lens 10 according to the present invention Sectional view of objective lens 10a according to the present invention Sectional view of the objective lens 10b according to the present invention Sectional view of objective lens 10c according to the present invention Sectional side view of the objective lens 10d according to the present invention Cross-sectional side view of hologram optical element 10e and objective lens 10f according to the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up apparatus 2 Light source 3 Collimator lens 4 Optical axis 5 Optical information recording medium 6 Information recording surface 7 Polarizing beam splitter 8 Detector 10, 10a, 10b, 10c, 10d, 10f Objective lens (Plastic optical element, objective optical element )
11, 11a, 11d, 12d, 22b Optical surface 20, 20a, 20b, 20c, 20d Optical path difference providing structure 21 First annular lens surface (annular lens surface)
22 Second annular lens surface (annular lens surface)
23 Third annular lens surface (annular lens surface)
23b Ring-shaped convex part

Claims (9)

A plastic optical element material, which is a resin composition containing an oligosiloxane-modified norbornene resin represented by the following general formula (1).

Wherein R ^{1 to} R ¹⁸ are each a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 10 carbon atoms, a cyano group, an amide Represents a group or an imide group and may be the same or different. R ¹⁷ and R ¹⁸ may be bonded to each other to form a monocyclic or polycyclic ring structure. R ¹⁹ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, R ²⁰ represents a single bond or a divalent organic group, and A represents an oligosiloxane group. a represents an integer of 0 to 2, and n represents an integer of 10 to 1,000,000. ] The oligosiloxane group (A) of the oligosiloxane-modified norbornene resin represented by the general formula (1) is represented by the T ⁿ structural unit represented by the following general formula (2) and the following general formula (3). The plastic optical element material according to claim 1, wherein the plastic optical element material is a group represented by the following general formula (4) including a D ^m structural unit:
General formula (2)
D ^m structural _{^{units: R 26 Si (OH) 3}} -n O n / 2
General formula (3)
T ⁿ structural _{^{units: R 27 Si (OH) 2}} -m O m / 2
[Wherein, n represents an integer of 1 to 3, and m represents 1 or 2. R ²⁶ and R ²⁷ each represents a hydrogen atom or a substituent. ]
General formula (4)
_{^{- (T 3 p T l q}} D o r)
[In the formula, T represents that the number of Si siloxane bonds represented by the general formula (3) is 3, and D represents the number of Si siloxane bonds represented by the general formula (2) is 2. It represents that. l represents 1 or 2, o represents 1 or 2, p represents an integer of 4 to 20, q and r each represents an integer of 0 to 20, and p + q + r ≧ 6. ] The said resin composition contains the polymer obtained by carrying out the polymerization reaction of the inorganic fine particle which has a reactive group, and the polyfunctional compound which has two or more reactive groups. Plastic optical element material. The inorganic fine particles having a reactive group are inorganic oxides and have at least one reactive group selected from a vinyl group, a (meth) acryloyl group, an epoxy group, an oxetanyl group, and a mercapto group. The plastic optical element material according to claim 3. A plastic optical element using the plastic optical element material according to any one of claims 1 to 4 and having a fine structure on an optical surface. 6. The plastic optical element according to claim 5, wherein a light transmittance at a wavelength of 400 nm of a molded article having a thickness of 3 mm molded using the plastic optical element material is 85% or more. 7. The plastic optical element according to claim 5, wherein the plastic optical element is used in a light collecting device having a light collecting function. An optical pickup device that performs either reproduction or recording of information on an optical information recording medium, the light source emitting light, the irradiation of the light emitted from the light source to the optical information recording medium, and the optical information An optical element unit that performs any of the collection of light reflected by the recording medium, and the optical element unit includes the plastic optical element according to any one of claims 5 to 7. A characteristic optical pickup device. The optical pickup device according to claim 8, wherein the light source emits light having a wavelength of 390 to 420 nm.

Images