JP2003192780A - Molding material for optical part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding material for optical part excellent in transparency, having low water absorption property, high refractive index, and low double refraction, excellent in chemicals resistance, and good in thermal characteristic (glass transition temperature), melt and fluidity property (molding and processing property), and mechanical characteristic, and high precision and high quality optical parts therefrom (for example, optical plastic lenses represented by an optical plastic lens for image pickup equipment, a pickup lens, etc.). <P>SOLUTION: This molding material for optical part has a specific weight average molecular weight and comprises a polycarbonate or a polycarbonate copolymer having repeating structural units represented by formulae (1-a) and (2-a). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a molding material for optical parts, which comprises a polycarbonate copolymer having a specific repeating structural unit. Further, it is represented by an optical component made of the molding material, specifically, an optical plastic lens for an imaging device such as a camera or a VTR, or a laser optical plastic lens such as a pickup lens used for optical information recording. It relates to various optical plastic lenses.

[0002]

2. Description of the Related Art Inorganic glass is used in a wide range of fields as a transparent optical material because it has excellent transparency and various physical properties such as small optical anisotropy. However, there are problems such as being heavy and easily broken, and having poor productivity, and in recent years, optical resins (organic optical materials) that replace inorganic glass have been actively developed.

One of the most important properties of an optical resin is transparency. To date, polymethylmethacrylate (PMMA), polycarbonate, polycycloolefin (COP) and the like have been known as typical optical resins having good transparency. In recent years, cameras,
Film-integrated camera (film with lens), various cameras for shooting and imaging such as video cameras; CD (compact disc), CD-ROM, CD-R, CD-R
An optical pickup device used for recording and reading information recording media such as W, CD-VIDEO, MO, and DVD;
An optical plastic lens manufactured by injection molding the above-mentioned optical resin is used for an optical system used in various devices such as a copying machine such as a copying machine and a printer.

PMMA is excellent in transparency and weather resistance and has good moldability, and is widely used as one of typical optical resins. However, the refractive index (nd) is 1.4
It has a relatively low value of 9 and has a large water absorption, which limits the fields of use. Polycycloolefin (COP) is excellent in transparency, low water absorption, and heat resistance, but its use as an optical component is limited because of its low refractive index (nd = 1.47 to 1.53).

Polycarbonate produced from 2,2-bis (4'-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) (hereinafter referred to as general-purpose polycarbonate) has transparency, heat resistance and impact resistance. It has a well-balanced characteristic such as dimensional stability, has a relatively high refractive index (nd = 1.59), and is used in optical applications represented by optical disk substrates for information recording.
However, it has drawbacks such as relatively large chromatic aberration (refractive index dispersion) and birefringence, and high melt viscosity and somewhat difficult moldability, so its application field as an optical resin is limited. There is. That is, for example, when general-purpose polycarbonate is used, birefringence (orientation) caused by residual stress due to thermal stress, molecular orientation, volume change in the vicinity of the glass transition point, etc. generated in the process of cooling and flowing the resin during injection molding The occurrence of birefringence and stress birefringence) and the large optical nonuniformity due to this birefringence is an important problem for optical components such as pickup lenses. Further, since the general-purpose polycarbonate has a high viscosity when melted, it is difficult to obtain a pickup lens or a small or thin plastic lens for precision optics by injection molding. .

As a method for solving the above-mentioned various problems, a novel polymer or a molding material has been proposed, for example, a polycarbonate containing a specific repeating structural unit derived from a specific bisphenol. It is disclosed that the copolymer is useful as a material for optical information recording medium substrates (Japanese Patent Laid-Open No. 63-223034).
Issue Bulletin). However, it cannot be said that it has sufficient characteristics as the above-mentioned material for optical plastic lenses.

On the other hand, recently, development of image pickup devices such as VTRs and digital still cameras (DSCs) has been promoted in search of higher resolution images. In these devices, a moire fringe may occur due to the relationship between the CCD array and the frequency of the shooting scene, and a striped pattern may appear in the image pickup. To prevent this phenomenon, a low pass filter is used. In general, general-purpose polycarbonate is used for plastic lenses of imaging equipment, and the optical anisotropy of the lens itself is large, so a single low-pass filter cannot eliminate the striped pattern and it is possible to use two or more sheets. is doing. The low-pass filter is expensive because it is manufactured using crystal, but there is a problem that the cost becomes higher if two or more filters are used.

Conventionally known polymers or molding materials are required to have transparency, water absorption, refractive index, and birefringence for use in various optical plastic lenses represented by optical plastic lenses for image pickup devices as described above. In terms of various physical properties such as refractive index (optical anisotropy), thermal properties (glass transition temperature), melt flowability (molding processability), mechanical properties, etc. Therefore, it has been strongly desired to develop an optical resin or a molding material for an optical component which satisfies these characteristics.

Further, a polycarbonate copolymer itself of α, α'-bis (4-hydroxyphenyl) -1,3-diisopropylbenzene (hereinafter referred to as bisphenol M) and bisphenol A is disclosed in, for example, JP-A-63 / 1988.
-89539, Japanese Patent Laid-Open No. 2-99521, Japanese Patent Laid-Open No. 2-208840, and the like. However, according to a study by the present inventors, when various polycarbonate copolymers suggested in these publications and the like were used as molding materials for optical plastic lenses, the optical properties obtained by injection molding were obtained. The chemical resistance of molded products such as plastic lenses to organic solvents was insufficient.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to overcome the above problems and to provide transparency, water absorption, refractive index, birefringence index, thermal index for optical parts, especially optical plastic lenses. Polycarbonate copolymer with good repeatability, which has well-balanced physical properties (glass transition temperature), melt flowability (molding processability), mechanical properties, etc. It is intended to provide a molding material for an optical component, which is a united body, and an optical component obtained by molding the molding material for an optical component.

[0011]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above-mentioned problems, and as a result, formed a polycarbonate copolymer having a specific repeating structural unit and a constant copolymerization ratio. The material has excellent transparency, low water absorption, high refractive index and low birefringence, and has good thermal properties (glass transition temperature), melt flowability (molding processability) and mechanical properties. It was found that the chemical resistance was excellent, and the present invention was reached.

That is, the present invention has a repeating structural unit represented by the formula (1-a) (formula 3) and the formula (2-a) (formula 4), and has the formula (1-a)
And the molar ratio of the repeating structural unit represented by the formula (1-a) and the repeating structural unit represented by the formula (2-a) in the repeating structural unit represented by the formula (2-a). ,
A molding material for optical parts, which is composed of a polycarbonate copolymer having a ratio of 90:10 to 35:65,

[0013]

[Chemical 3]

[0014]

[Chemical 4]

Weight average content of polycarbonate copolymer
The amount of gel permeation chromatography (G
PC) 20 in terms of standard polystyrene
× 10 ³~ 200 × 10³Which is a molding material for optical parts
Fee, Obtained by molding the molding material for optical parts described above
Optical components, Obtained by molding the molding material for optical parts described above
Optical plastic lens, Molding the optical component molding material described in the above
Pickup lens obtained by
Light for imaging equipment obtained by molding the molding material for optical components
Gaku plastic lenses.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The molding material for optical parts of the present invention has a repeating structural unit represented by formula (1-a) and formula (2-a),
And a repeating structural unit represented by the formula (1-a) and a repeating structural unit represented by the formula (2-a) in the repeating structural units represented by the formula (1-a) and the formula (2-a). Is a molding material containing a polycarbonate copolymer having a molar ratio of repeating structural units of 90:10 to 35:65, and is suitable as a molding material for optical parts, particularly optical plastic lenses. Used for. The molding material for optical parts of the present invention preferably contains a phosphorus atom-containing antioxidant or / and a phenolic antioxidant in addition to containing the above polycarbonate copolymer as an essential constituent component. Is a molding material. The molding material for optical parts of the present invention is injection molded,
Molding can be performed by various known molding methods such as injection compression molding and extrusion molding.

In the polycarbonate copolymer according to the molding material for optical parts of the present invention, the molar ratio of the repeating structural unit represented by the formula (1-a) to the repeating structural unit represented by the formula (2-a). Is 90:10 to 40:60, preferably 85:15 to 45:55, and more preferably 80:20 to 50:50.

Regarding the molecular weight of the polycarbonate copolymer according to the present invention, the weight average molecular weight is 10 × 10 ^{3 to} 300 as a standard polystyrene-equivalent molecular weight measured by GPC (gel permeation chromatography).
× 10 ³ , preferably 20 × 10 ³ to 200 × 1
0 ³ and more preferably 25 × 10 ^{3 to} 150 × 1
0 ³ and more preferably 30 × 10 ^{3 to} 100 ×
It is 10 ³ . When the weight average molecular weight is less than 10 × 10 ³ , the water absorption of the optical component obtained by molding the polycarbonate increases, the mechanical properties are weak and insufficient, and the desired effects of the present invention are impaired. Not preferable. On the other hand,
When the weight average molecular weight exceeds 300 × 10 ³ , the melt flowability of the resin is extremely lowered, so molding processing is required when molding optical parts such as pickup lenses that require small and precise shapes and dimensional accuracy. Poor nature, moreover,
This is not preferable because it causes problems such as high birefringence of the obtained optical component.

The polydispersity index of the polycarbonate according to the present invention, which is expressed as the ratio of the weight average molecular weight to the number average molecular weight, is usually 1.5 to 25.0, preferably 1.5 to 20. 0, and more preferably
It is 2.0 to 15.0.

The molding material for optical parts of the present invention is the above-mentioned GP.
In the C analysis, the content (area%) of the oligomer in the region where the weight average molecular weight is 5 × 10 ³ or less is preferably 12% or less. If the content of the oligomer exceeds 12%, problems such as contamination of the mold surface during molding and deterioration of releasability from the mold occur, which is not preferable. On the other hand, it is very difficult to completely remove the oligomer, but when the content of the oligomer is less than 0.1%, the melt fluidity of the molding material for optical parts of the present invention tends to decrease. However, the effect of the present invention is not sufficiently obtained, which is not preferable. The molding material for optical parts of the present invention more preferably has a content of the oligomer of 0.1% to 10%.
And more preferably 0.5 to 8%.

The molding material for optical parts of the present invention is ASTM
The water absorption rate measured by the water absorption rate according to D-0570 is 0.
It is preferably not more than 35% by weight, more preferably not more than 0.3% by weight, still more preferably not more than 0.3.
It is particularly preferable that it is 25% by weight or less and the water absorption rate is 0.2% by weight or less.

The molding material for optical parts of the present invention is preferably highly purified, and it is preferable that a certain amount or more of insoluble particles are not present in the molding material. The insoluble particles are a general term for impurities such as dust, dust, and foreign substances contained in the molding material. If the molding material or the molding (optical part) is incompatible with the molding material, the It causes scattering and causes deterioration of transparency.

Specifically, the insoluble particles measured with a liquid particle counter in a solution prepared by dissolving the molding material for optical parts of the present invention in dichloromethane have a particle-converted diameter of 0.5 μm per 1 g of the molding material. The above number is preferably 3 × 10 ⁴ or less, more preferably 2.5 × 10 ⁴ or less, and further preferably
It is 2 × 10 ⁴ or less. Further, in the molding material for optical parts, it is preferable that substantially no insoluble particles having a particle-converted diameter of 50 μm or more are detected. Further preferably less insoluble particles particle equivalent diameter 0.5μm is 3 × 10 ⁴ or less, more preferably, is 3 × 10 ⁴ or less.

In the polycarbonate according to the present invention,
The terminal group may be a reactive terminal group such as a hydroxy group, a haloformate group or a carbonic acid ester group, or may be an inactive terminal group capped with a molecular weight modifier as described below. . Preferred is an inactive end group sealed with a molecular weight regulator. Examples of the structural unit of the terminal group include structural units derived from a molecular weight regulator as described below. The amount of terminal groups in the polycarbonate according to the present invention is not particularly limited, but is generally related to the molecular weight of the polymer, and usually relative to the total number of moles of the structural unit,
0.001 to 10 mol%, preferably 0.01
˜5 mol%, and more preferably 0.05 to 3 mol%.

The polycarbonate copolymer itself according to the present invention can be produced by various known polycarbonate polymerization methods [for example, Experimental Chemistry Lecture 4th Edition (28) Polymer Synthesis, 231-
242, Maruzen Shuppan (1988), solution polymerization method, transesterification method or interfacial polymerization method, etc.]
It is preferably manufactured.

When the polycarbonate copolymer according to the present invention is produced by a polymerization reaction according to the above-mentioned method, it is preferable to carry out the polymerization in the presence of a molecular weight modifier for the purpose of controlling the molecular weight. The molecular weight regulator is not particularly limited, and known molecular weight regulators used in polycarbonate polymerization can be used. For example, a monovalent hydroxy aliphatic compound or a hydroxy aromatic compound, or a derivative thereof (for example, an alkali metal or alkaline earth metal salt of a monovalent hydroxy aliphatic compound or a hydroxy aromatic compound, a monovalent hydroxy aliphatic compound Compound or hydroxyaromatic compound haloformate compound, monovalent hydroxyaliphatic compound or hydroxyaromatic compound carbonate ester, etc.), 1
Carboxylic acids or derivatives thereof (for example, alkali metal or alkaline earth metal salts of monovalent carboxylic acids, 1
Acid halide of monovalent carboxylic acid, ester of monovalent carboxylic acid, etc.) and the like.

Among these molecular weight regulators, a monovalent hydroxyaromatic compound or a derivative thereof is preferable, and a phenol or a phenol substituted with an alkyl group or a derivative thereof is more preferable. The amount of the molecular weight regulator used is not particularly limited,
It may be used as desired in order to adjust the molecular weight to a desired value. Usually, it is 0.001 to 10 mol%, preferably 0.01 to 5 mol% based on the total number of moles of dihydroxy compounds to be polymerized.

The polycarbonate copolymer of the present invention has the formula (1-) within the range that does not impair the desired effects of the present invention.
In addition to the repeating structural unit represented by a) and the formula (2-a), other repeating structural units may be contained.

In this case, the formula (1
-A) and the proportion of the repeating structural unit represented by the formula (2-a) are usually 50 mol% or more, preferably 70 mol%, more preferably 80 mol%.
It is above, and more preferably 90 mol% or above.

The repeating structural unit other than the formula (1-a) and the formula (2-a) used in the present invention means the formula (1)
Bisphenol M represented by (Chemical Formula 5) and formula (2)
It is a repeating structural unit derived from a dihydroxy compound other than bisphenol A represented by the chemical formula (6).
As such a dihydroxy compound, various known aromatic dihydroxy compounds or aliphatic dihydroxy compounds can be exemplified.

[0031]

[Chemical 5]

[0032]

[Chemical 6]

Specific examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane,
1,1-bis (4'-hydroxyphenyl) ethane, 1,2-bis (4'-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4 -Hydroxyphenyl) -1-naphthylmethane, 1,1-bis (4'-hydroxyphenyl) -1-phenylethane, 2- (4'-hydroxyphenyl) -2- (3'-hydroxyphenyl) propane, 2 , 2-bis (4'-hydroxyphenyl) butane, 1,1-bis (4'-hydroxyphenyl) butane, 2,2-bis (4'-hydroxyphenyl) -3-methylbutane, 2,2-bis ( 4'-hydroxyphenyl) pentane, 3,3-bis (4'-hydroxyphenyl) pentane, 2,2-bis (4'-hydroxyphenyl) hexane, 2,2-bis (4'-hydroxyphenyl) octane, 2,
2-bis (4'-hydroxyphenyl) -4-methylpentane, 2,
2-bis (4'-hydroxyphenyl) heptane, 4,4-bis
(4'-hydroxyphenyl) heptane, 2,2-bis (4'-hydroxyphenyl) tridecane, 2,2-bis (4'-hydroxyphenyl) octane, 2,2-bis (3'-methyl-4 ' -Hydroxyphenyl) propane, 2,2-bis (3'-ethyl-
4'-hydroxyphenyl) propane, 2,2-bis (3'-n
-Propyl-4'-hydroxyphenyl) propane, 2,2-
Bis (3′-isopropyl-4′-hydroxyphenyl) propane, 2,2-bis (3′-sec-butyl-4′-hydroxyphenyl) propane, 2,2-bis (3′-tert-butyl-4) '-Hydroxyphenyl) propane, 2,2-bis (3'
-Cyclohexyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-allyl-4'-hydroxyphenyl)
Propane, 2,2-bis (3'-methoxy-4'-hydroxyphenyl) propane, 2,2-bis (3 ', 5'-dimethyl-4'-hydroxyphenyl) propane, 2,2-bis (2 ', 3', 5 ', 6'-
Tetramethyl-4'-hydroxyphenyl) propane, bis (4-hydroxyphenyl) cyanomethane, 1-cyano
Bis (hydroxyaryl) alkanes such as -3,3-bis (4'-hydroxyphenyl) butane and 2,2-bis (4'-hydroxyphenyl) hexafluoropropane;

1,1-bis (4'-hydroxyphenyl) cyclopentane, 1,1-bis (4'-hydroxyphenyl) cyclohexane, 1,1-bis (4'-hydroxyphenyl) cycloheptane, 1,1 -Bis (3'-methyl-4'-hydroxyphenyl) cyclohexane, 1,1-bis (3 ', 5'-dimethyl-
4'-hydroxyphenyl) cyclohexane, 1,1-bis (3 ', 5'-dichloro-4'-hydroxyphenyl) cyclohexane, 1,1-bis (3'-methyl-4'-hydroxyphenyl) -4- Methylcyclohexane, 1,1-bis (4'-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,
2-bis (4'-hydroxyphenyl) norbornane, 2,2-
Bis (hydroxyaryl) cycloalkanes such as bis (4'-hydroxyphenyl) adamantane; 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,
Bis (hydroxyaryl) ethers such as 3'-dimethyldiphenyl ether and ethylene glycol bis (4-hydroxyphenyl) ether; 4,4'-dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide , 3,3'-dicyclohexyl-
Bis (hydroxyaryl) sulfides such as 4,4'-dihydroxydiphenyl sulfide and 3,3'-diphenyl-4,4'-dihydroxydiphenyl sulfide; 4,4'-dihydroxydiphenyl sulfoxide, 3,3'-dimethyl- Four,
Bis (hydroxyaryl) sulfoxides such as 4'-dihydroxydiphenyl sulfoxide; Bis (hydroxyaryl) sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone; Bis (hydroxyaryl) ketones such as bis (4-hydroxyphenyl) ketone and bis (4-hydroxy-3-methylphenyl) ketone;
α, α′-bis (4-hydroxyphenyl) -1,4-
Diisopropylbenzene (bisphenol P), 6,6'-
Dihydroxy-3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, 7,7'-dihydroxy-3,3', 4,4'-tetrahydro-4,4,4 ', 4'-Tetramethyl-2,2'-spirobi (2H-1
-Benzopyran), trans-2,3-bis (4'-hydroxyphenyl) -2-butene, 9,9-bis (4'-hydroxyphenyl) fluorene, 3,3-bis (4'-hydroxyphenyl)- Examples of the dihydroxy compound include 2-butanone, 1,6-bis (4'-hydroxyphenyl) -1,6-hexanedione, 4,4'-dihydroxybiphenyl, hydroquinone and resorcin. Also included are aromatic dihydroxy compounds containing an ester bond which can be prepared, for example, by reacting 2 mol of bisphenol A with 1 mol of isophthaloyl chloride or terephthaloyl chloride.

Specific examples of the aliphatic dihydroxy compound include 1,2-dihydroxyethane, 1,3-dihydroxypropane, 1,4-dihydroxybutane and 1,5-
Dihydroxypentane, 3-methyl-1,5-dihydroxypentane, 1,6-dihydroxyhexane, 1,7
-Dihydroxyheptane, 1,8-dihydroxyoctane, 1,9-dihydroxynonane, 1,10-dihydroxydecane, 1,11-dihydroxyundecane, 1,
12-dihydroxydodecane, dihydroxyneopentyl, 2-ethyl-1,2-dihydroxyhexane, 2-
Dihydroxyalkanes such as methyl-1,3-dihydroxypropane; 1,3-dihydroxycyclohexane,
Mention may be made of dihydroxycycloalkanes such as 1,4-dihydroxycyclohexane and 2,2-bis (4′-hydroxylcyclohexyl) propane. Furthermore, o-dihydroxyxylylene, m-dihydroxyxylylene, p-dihydroxyxylylene, 1,4-bis (2'-hydroxyethyl) benzene, 1,4-bis (3'-hydroxypropyl) benzene, 1, 4-bis (4'-hydroxybutyl) benzene, 1,4-bis (5'-hydroxypentyl) benzene, 1,4-bis (6'-hydroxyhexyl) benzene, 2,2-bis [4 '-( 2 "-hydroxyethyloxy) phenyl]
Propane, 2,2-bis [4 '-(2 "-hydroxyepropyloxy) phenyl] propane, 6,6'-bis (2
"-Hydroxyethyloxy) -3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane, 6,6'-bis (2" -hydroxypropyloxy) -3,3,3', 3 '-Tetramethyl-1,1'-
Dihydroxy compounds such as spirobiindane may be mentioned.

In order to obtain the desired effect of the present invention to the maximum, another repeating structural unit containing only the repeating structural unit represented by the formula (1-a) and the formula (2-a) is contained. The non-polycarbonate binary copolymer is particularly preferred.

In order to adjust the amount of the insoluble particles in the polycarbonate copolymer according to the present invention to a preferable range as the molding material for optical parts as described above, the polymerization reaction step, the isolation step and the pelletization step (preparation step) are performed. In the granulation step), it is necessary to carry out an operation and a method in which the insoluble particles are not mixed or can be removed.

As such an operation and method, for example, an operation of filtering a polymer solution or a liquid polymer using various known filters after the polymerization reaction and / or before the polymer isolation step, insoluble particles Examples include, but are not limited to, a method of using a granulating device equipped with a removing device (such as a pelletizer) and a method of performing the above-described series of operations in a clean room.

As described above, the molding material for optical parts of the present invention contains, in addition to the polycarbonate copolymer of the present invention as an essential component, a phosphorus atom-containing antioxidant and / or a phenolic antioxidant. Is preferably added and contained, and the molding material is composed of these constituent components.

The addition amount of the phosphorus atom-containing compound compounded in the molding material for optical parts of the present invention is usually 100 parts by weight of the polycarbonate copolymer of the present invention.
0.01 to 5 parts by weight, preferably 0.02 to 2
Parts by weight, and more preferably 0.05 to 1 parts by weight.

As such phosphorus atom-containing antioxidant,
Examples include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid and ester derivatives thereof. Specific examples of such compounds include, for example, trimethylphosphite, triethylphosphite, tributylphosphite, trioctylphosphite, tris (2-ethylhexylphosphite), trinonylphosphite, tridecylphosphite, tris (tridecyl). Phosphite, trioctadecyl phosphite, tristearyl phosphite, tris (2-chloroethyl) phosphite, tris (2,3-dichloropropyl phosphite), tricyclohexyl phosphite, triphenyl phosphite,
Tricresyl phosphite, tris (ethylphenyl)
Phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, phenyl-didecylphosphite, diphenyl-
Isooctyl phosphite, diphenyl-2-ethylhexyl phosphite, diphenyl-decyl phosphite, diphenyl-tridecyl phosphite, bis (tridecyl) -pentaerythyryl-diphosphite, distearyl-pentaerythyryl-diphosphite, diphenyl-pentaeryth Styryl-diphosphite, bis (nonylphenyl) -pentaerystyryl-diphosphite, bis (2,4-di-tert-butylphenyl)
-Pentaerystyryl-diphosphite, bis (2,6
-Di-tert-butyl-4-methylphenyl) -pentaerythyryl-diphosphite, tetraphenyl-dipropylene glycol-diphosphite, tetra (tridecyl) -4,4'-isopropylidene diphenyl-diphosphite, tetra (2,4- Phosphorous acids such as di-tert-butylphenyl) -4,4′-diphenylphosphite, tetraphenyltetra (tridecyl) pentaerythyryltetraphosphite, trilauryltrithiophosphite; trimethylphosphate, triethylphosphate, tributylphosphate, Phosphoric acids such as triphenyl phosphate, diphenyl mono-orthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate; tetrakis (2,4-di) tert- butylphenyl) -
Examples thereof include phosphonous acids such as 4,4-diphenylenephosphonite; and phosphonic acids such as dimethyl benzenephosphonate, diethyl benzenephosphonate, and diisopropyl benzenephosphonate, but are not limited thereto. Among these phosphorus atom-containing compounds, phosphorous acid derivatives are preferable, and phosphoric acid ester derivatives are preferable.
These phosphorus compounds may be used alone or in combination of two or more kinds.

The amount of the phenolic antioxidant added to the molding material for optical parts of the present invention is usually 0.0001 to 2 parts by weight based on 100 parts by weight of the polycarbonate copolymer of the present invention. Yes, preferably 0.
001 to 1 part by weight, and more preferably 0.01 to
0.5 parts by weight. Moreover, as a phenolic antioxidant, for example, octadecyl-3- (3,5-di-t
ert-Butyl-5-methyl-4-hydroxyphenyl) propionate, triethyleneglycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythritol-tetrakis [3- (3,3
5-Di-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) ) Benzene, N, N-hexamethylenebis (3,5-di-tert-butyl-4-
Hydroxy-hydrocinnamide), 3,5-di-te
Examples thereof include various known phenolic antioxidants such as rt-butyl-4-hydroxybenzylphosphonate diethyl ester and tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, but are not limited thereto. It is not something that will be done. These phenolic antioxidants may be used alone or in combination of two or more kinds.

Furthermore, in the molding material for optical parts of the present invention, higher fatty acid esters of monohydric or polyhydric alcohols are added, if necessary, for the purpose of improving the mold releasability from the mold during melt molding. Is preferable. The amount of the higher fatty acid ester added to the molding material for optical parts of the present invention is determined by the polycarbonate copolymer according to the present invention.
It is usually 0.0001 to 2 parts by weight, preferably 0.001 to 1 part by weight, and more preferably 0.01 to 0.5 part by weight, relative to 100 parts by weight. The higher fatty acid esters are more preferably monohydric or polyhydric alcohols having 1 to 20 carbon atoms and 10 to 3 carbon atoms.
It is a partial or total ester of saturated fatty acid of 0. Specific examples of the higher fatty acid esters include stearic acid monoglyceride, stearic acid monosorbate, behinic acid monoglyceride, pentaerythritol monostearate, pentaerythritol tetrastearate, propylene glycol monostearate, and steryl stearate. Palmityl palmitate,
Butyl stearate, methyl laurate, isopropyl palmitate, 2-ethylhexyl stearate and the like can be mentioned, but not limited thereto. These higher fatty acid esters may be used alone or in combination of two or more.

The molding material for optical parts of the present invention contains various known additives other than the above-mentioned antioxidants, such as an ultraviolet absorber, during the production or molding, so long as the desired effects of the present invention are not impaired. , Release agents, lubricants, flame retardants (for example, organic halogen compounds, phosphorus compounds, etc.), fluidity improvers, antistatic agents, heat stabilizers (for example, phenolic compounds, sulfur compounds, metal phosphate salts, and (Metal phosphate metal salt, etc.) may be contained.

The above-mentioned additives can be added to the molding material for optical parts of the present invention by any method. As such a method, for example, a tumbler mill,
A method of mixing with a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, an extruder and the like can be mentioned.

The molding material for optical parts of the present invention is thermoplastic and can be injection-molded, injection-compression-molded, extrusion-molded, blow-molded in a molten state, and further known by various methods such as compression molding and solution casting. It can be molded by a molding method. Optical parts such as the optical plastic lens of the present invention are preferably manufactured by these molding methods.

The optical parts obtained by molding the molding material for optical parts of the present invention are typically a camera, a VTR.
Examples include optical plastic lenses for imaging devices, pickup objective lenses, collimation lenses, Fresnel lenses, fθ lenses, and other various optical plastic lenses. These optical components are suitably molded and manufactured by the conventionally known various molding methods described above (preferably injection molding, injection compression molding, etc.).

[0048]

The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. The polycarbonate copolymer produced in the following Production Examples and Examples, and the measurement of the physical properties of the molding material for optical parts containing the polycarbonate copolymer,
The following method was used. [Measurement of weight average molecular weight and oligomer amount] GPC was used to prepare a 0.2 wt% chloroform solution of the polycarbonate obtained in each of Production Examples, Examples and Comparative Examples described below.
(Gel Permeation Chromatography) [System-11, Showa Denko KK]
The weight average molecular weight (Mw) was determined. The measured values are standard polystyrene equivalent values. Further, in the GPC analysis chart, the ratio (percentage) of the peak area showing a weight average molecular weight of 5,000 or less to the total peak area of the polymer was calculated to obtain the amount of oligomer. [Measurement of Water Absorption] It was measured according to ASTM D-0570. [Refractive index, Abbe number] The obtained molding material is press-molded by a press machine at 260 ° C to prepare a sheet-shaped test piece,
It measured at 20 degreeC using the Pulfrich refractometer. [Birefringence] A 5 μm-thick thin film of the obtained molding material was formed on a silicon wafer. That is, a 1,1,1-trichloroethane solution (20% concentration) of each molding material was filtered through a Teflon (registered trademark) filter having a pore diameter of 0.45 μm, and then rotated on a silicon wafer (diameter 5 inches) at a rotation speed of 2000 rpm, Spin coating was performed for 5 seconds. Then, it dried at 70 degreeC for 15 minutes, the solvent was distilled off, and the 5-micrometer-thick thin film of this molding material was created. A 632 nm laser light source was used using a prism coupler (Metricon model 2020) to measure the refractive index of the thin film with TE mode light and TM mode light, and the birefringence was calculated as the difference between them. [Measurement of glass transition temperature] Differential scanning calorimeter (DSC-
3100, manufactured by Mac Science Co., Ltd., 0 ° C to 300 ° C
The differential thermal analysis (DSC method) was performed and measured in the temperature range of. [Chemical resistance] The molded product obtained by molding the molding material for optical parts of the present invention was immersed in isopropanol at room temperature for 12 hours, and then the condition of the molded product was visually observed.

Production Example 1 (Production of Polycarbonate Copolymer) A baffled flask having an internal volume of 2 liters was equipped with a stirrer equipped with a lattice blade, a reflux condenser, and a dip tube for blowing phosgene. In this flask, α, α′-bis (4-hydroxyphenyl) -1,3-diisopropylbenzene (bisphenol M) 86.63 g (0.25 mol), 2,2-bis (4′-hydroxyphenyl) propane (Bisphenol A) 57.08 g (0.25 mol), sodium hydroxide 56 g (1.40 mol), phenol 0.942 g (0.010 mol; 2 mol% based on the total number of moles of dihydroxy compounds) and Ion-exchanged water (600 g) was charged to prepare a sodium salt slurry solution of the bisphenol mixture. 600 ml of dichloromethane was added to the slurry solution, and the mixture obtained was stirred vigorously while adding 5 ml to the mixture.
9.4 g (0.60 mol) of carbonyl chloride 10 g /
It was fed at a feed rate of minutes. After the carbonyl chloride feed was complete, 0.08 g of triethylamine was added to the reaction mixture and stirred and mixed for an additional 90 minutes. Then, the stirring was stopped, the reaction mixture was separated, the dichloromethane phase was neutralized with an aqueous hydrochloric acid solution, and ion-exchanged water was used for washing until no electrolyte was substantially detected in the aqueous washing liquid.
Then isolation of the polycarbonate from the dichloromethane solution and granulation (pelletization) of the polycarbonate
Was carried out in a clean room (class 1000).
The solvent (methanol, acetone, etc.) and ion-exchanged water used were filtered with a filter having a pore diameter of 0.45 μm to remove suspended matters, foreign matters and the like. Further, the instruments and devices used were washed with the solvent or water purified by the above method. The dichloromethane solution described above was applied to a Teflon (registered trademark) filter (pore size 0.4
5 μm) and then add 4 to 1 liter of deionized water.
The solution was dropped very slowly at 5 ° C., and the precipitated white powdery polymer was collected by filtration and dried under reduced pressure. Formula (1-a)
130 g of a polycarbonate copolymer containing a repeating structural unit represented by the formula (2-a) was obtained. When the GPC analysis of the obtained polycarbonate was performed according to the above method, the weight average molecular weight was 50 × 10 ³ in terms of standard polystyrene, and the weight average molecular weight was 5 × 10 ³ or less. It was 0.0%. D
Glass transition temperature (Tg) measured by SC method is 133 ° C
Met. ¹ H-NMR of the obtained polycarbonate
(1 wt% deuterated chloroform solution) and IR measurement results are shown below. IR (KBr method): 1780 cm-1 [-O-C (=
O) -O-] ¹ H-NMR measurement result, and from the integral ratio of the proton of the isopropylidene group in the bisphenol M structure and the proton of the propylidene group in the bisphenol A structure, the formula ( The ratio (molar ratio) of the structural unit represented by 1-a) to the structural unit represented by the formula (2-a) is 5
It was confirmed to be 0:50.

Production Example 2 In Production Example 1, α, α'-bis (4-hydroxyphenyl) -1,3-diisopropylbenzene (bisphenol M) 86.63 g (0.25 mol), 2,2-
Instead of using bis (4′-hydroxyphenyl) propane (bisphenol A) 57.08 g (0.25 mol), α, α′-bis (4-hydroxyphenyl)
69.30 g (0.20 mol) of -1,3-diisopropylbenzene (bisphenol M) and 68.50 g (0.30 mol) of 2,2-bis (4'-hydroxyphenyl) propane (bisphenol A) are used. Except for the above, the same procedure as in Production Example 1 was carried out. GPC
Analysis showed that the weight average molecular weight was 60 × 10 ³ in terms of standard polystyrene and the weight average molecular weight was 5 × 10 ³
The amount of oligomers (area%) below was 6.5%. The glass transition temperature (Tg) is 1 as measured by the DSC method.
It was 26 ° C. As a result of 1 H-NMR measurement, the ratio (molar ratio) of the structural unit represented by the formula (1-a) and the structural unit represented by the formula (2-a) contained in the copolymer was 4
It was confirmed to be 0:60.

Comparative Production Example 1 According to a known method for producing a general-purpose polycarbonate,
A polycarbonate of bisphenol A was produced. That is, in Production Example 1, α, α′-bis (4-hydroxyphenyl) -1,3-diisopropylbenzene (bisphenol M) 86.63 g (0.25 mol), 2,
Instead of using 57.08 g (0.25 mol) of 2-bis (4′-hydroxyphenyl) propane (bisphenol A), 114.2 g (0.50) of bisphenol A
The same procedure as in Preparation Example 1 was carried out except that the bisphenol A polycarbonate was used. The weight average molecular weight was 50 × 10 ³ . The glass transition temperature (Tg) is 1 as measured by the DSC method.
It was 50 ° C.

Comparative Production Example 2 In Production Example 1, α, α'-bis (4-hydroxyphenyl) -1,3-diisopropylbenzene (bisphenol M) 34.65 g (0.10 mol), 2,2-
Instead of using 91.32 g (0.40 mol) of bis (4′-hydroxyphenyl) propane (bisphenol A), α, α′-bis (4-hydroxyphenyl)-
1,3-diisopropylbenzene (bisphenol M)
8.66 g (0.025 mol), 2,2-bis (4 '
-Hydroxyphenyl) propane (bisphenol A)
Other than using 108.44 g (0.475 mol)
The same procedure as in Production Example 3 was carried out. By GPC analysis, the weight average molecular weight is 5 in terms of standard polystyrene.
The amount of oligomer (area%) of 5 × 10 ³ and the weight average molecular weight of 5 × 10 ³ or less was 5.0%. The glass transition temperature (Tg) is 1 as measured by the DSC method.
It was 44 ° C. As a result of 1 H-NMR measurement, the ratio (molar ratio) of the structural unit represented by the formula (1-a) and the structural unit represented by the formula (2-a) contained in the copolymer was 5 :
It was confirmed to be 95.

Example 1 (Production of molding material for optical parts of the present invention using the polycarbonate copolymer produced in Production Example 1) Polycarbonate copolymer produced in Production Example 1 100
Parts by weight, tris (2,4-di-tert-butylphenyl) phosphite 0.1 parts by weight and pentaerystyryl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] 0. 1 part by weight,
After mixing with a Henschel mixer, a single screw extruder (65
mm) at a cylinder temperature of 235 ° C. while being melted and kneaded, and extruded into pellets to obtain a molding material for optical parts (pellet-like material) of the present invention.

Example 2 (Production of Molding Material for Optical Parts of the Present Invention Using Polycarbonate Copolymer Produced in Production Example 2) Polycarbonate Copolymer produced in Production Example 2 100
Parts by weight, tetraphenyltetra (tridecyl) pentaerystyryl tetraphosphite 0.1 parts by weight and pentaerythyryl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] 0.1 parts by weight Were mixed in a Henschel mixer, and then melt-kneaded with a single screw extruder (65 mm) at a cylinder temperature of 230 ° C. while being degassed, and extruded into pellets to obtain a molding material for optical parts (pellet-like material). Got

Comparative Example 1 (Production of Molding Material for Optical Parts of the Present Invention Using Polycarbonate Produced in Comparative Production Example 1) General-purpose Polycarbonate 100 produced in Comparative Production Example 1
Parts by weight, tris (2,4-di-tert-butylphenyl) phosphite 0.1 parts by weight and pentaerythyryl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] 0. After mixing 1 part by weight with a Henschel mixer, a single screw extruder (65 m
m) was melt-kneaded while degassing at a cylinder temperature of 260 ° C., and extruded into pellets to obtain a molding material (pellet-like material).

Comparative Example 2 (Production of Molding Material for Optical Parts of the Present Invention Using Polycarbonate Copolymer Produced in Comparative Production Example 2) Polycarbonate Copolymer Produced in Comparative Production Example 2 1
00 parts by weight, tris (2,4-di-tert-butylphenyl) phosphite 0.1 parts by weight and pentaerythyryl [3- (3,5-di-tert-butyl-4-
0.1 parts by weight of (hydroxyphenyl) propionate] was mixed in a Henschel mixer, and then melt-kneaded with a single screw extruder (65 mm) at a cylinder temperature of 250 ° C. while degassing, and extruded into pellets to obtain a molding material ( Pellets) were obtained. The above results are shown in Table 1 (Table 1).

Example 3 (Production of Lens Using Molding Material for Optical Parts of the Present Invention) 3 pellets of the molding material for optical parts manufactured in Example 1 were used.
Molding temperature 270 ° C, mold temperature 7 with 0t direct pressure molding machine
Injection molding at 0 ℃, colorless and transparent, plus lens (convex lens; diameter 75mm, center thickness 4.2mm, edge thickness 1.0m)
m, +2.00 D) shaped molded body was obtained. When this molded product was observed between polarizing plates, striae, distortion, etc. were not observed, and it was an optically homogeneous one with low birefringence. As described above, by using the molding material of the present invention, the temperature (260
It was possible to favorably manufacture an optically homogeneous lens that was moldable at (° C). The chemical resistance of the obtained molded product (lens) was good.

Comparative Example 3 (Manufacture of Lens Using Molding Material Produced in Comparative Example 1) The molding material (pellets) made of the general-purpose polycarbonate manufactured in Comparative Example 1 was molded at a molding temperature of 300 tons with a 30t direct pressure molding machine. Injection molding at a mold temperature of 110 ° C. to obtain a colorless and transparent molded product having a plus lens (convex lens; diameter 75 mm, center thickness 4.2 mm, edge thickness 1.0 mm, +2.00 D). When this molded product was observed between polarizing plates, birefringence, which is thought to be derived from resin orientation, stress distortion, etc. during molding, was observed, and it was optically inhomogeneous. Further, when a chemical resistance test was conducted using the obtained molded product (lens), the surface was corroded by the solvent after the test and became cloudy in white, and the chemical resistance was not sufficient.

Comparative Example 4 (Production of Lens Using Molding Material Produced in Comparative Example 2) The molding material (pellet) produced in Comparative Example 2 was molded by a 30t direct pressure molding machine at a molding temperature of 295 ° C. and a mold. Temperature 110 ℃
Injection-molded with a colorless, transparent, plus lens (convex lens;
Diameter 75 mm, center thickness 4.2 mm, edge thickness 1.0 mm,
A molded product having a shape of +2.00 D) was obtained. When this molded product was observed between polarizing plates, birefringence, which is thought to be derived from resin orientation, stress distortion, etc. during molding, was observed, and it was optically inhomogeneous. Further, when a chemical resistance test was conducted using the obtained molded product (lens), the surface was corroded by the solvent after the test and became cloudy in white, and the chemical resistance was not sufficient.

[0060]

[Table 1]

[0061]

The molding material for optical parts comprising the polycarbonate copolymer having the specific repeating structural unit of the present invention has excellent transparency and low birefringence, and particularly excellent chemical resistance. With such a molding material, high precision and high quality optical parts (for example, optical plastic lenses for imaging devices such as cameras and VTRs, laser optical plastic lenses such as pickup lenses used for optical information recording media, etc.) The optical plastic lens typified by 1) can be suitably manufactured and provided.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichi Fujii             32 Mitsui Chemicals, 580 Nagaura, Sodegaura City, Chiba Prefecture             Within the corporation (72) Inventor Hiromasa Marubayashi             32 Mitsui Chemicals, 580 Nagaura, Sodegaura City, Chiba Prefecture             Within the corporation F-term (reference) 4J029 AA10 AB07 AC02 AD01 AE04                       BB13A BB16A HA01 HC01                       JA091 JB191 JC031 JF031                       KC01 KE09

Claims (6)

[Claims] 1. A formula (1-a) (Formula 1) and a formula (2-
a) having the repeating structural unit represented by the chemical formula 2 and occupying in the repeating structural unit represented by the formula (1-a) and the formula (2-a), A molding material for optical parts, comprising a polycarbonate copolymer having a molar ratio of the repeating structural unit represented by the formula (2-a) to 90:10 to 35:65. [Chemical 1] [Chemical 2] 2. The weight average molecular weight of the polycarbonate copolymer is determined by gel permeation chromatography (G
PC) 20 in terms of standard polystyrene
The molding material for optical parts according to claim 1, which has a density of × 10 ³ to 200 × 10 ³ . 3. An optical component obtained by molding the molding material for optical components according to claim 1. 4. An optical plastic lens obtained by molding the molding material for optical parts according to claim 1. 5. A pickup lens obtained by molding the molding material for optical parts according to claim 1. 6. An optical plastic lens for an imaging device obtained by molding the molding material for optical parts according to claim 1.