JP2001074915A - Toric lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make decreasabe a region where harmful double refraction is generated near the surface of a lens molded body, and as a result, to avoid unnecessary increase in the width of the molded product and to decrease the cooling period for molding and to improve the productivity. SOLUTION: The toric lens consists cof an injection-molded product of a synthetic resin having a stress optical coefficient CR satisfying |CR|<=10-9 Pa-1, and is used as a lens for laser rays having a rectangular cross section with length L and width W satisfying L>W and having >=5 mm maximum thickness. The lens is molded in such a manner that the region at 2.8 mm distance from the end of the W direction, interference fringes with <=0.5 mm interval are not observed. The synthetic resin is preferably at least one kind of cyclic olefin resin selected from the group consisting of α-olefin-cyclic olefin random copolymer [A-1] derived from 2-20C α-olefin and cyclic olefin of a specified structure, ring-opening polymer or copolymer [A-2] of cyclic olefin, hydrogenated compound of [A-2] [A-3], and grafted modified produce [A-4] of [A-1], [A-2] or [A-3].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toric lens used in a laser optical system, and more particularly, to an f.theta. Lens which is hardly affected by birefringence up to a lens end.

[0002]

BACKGROUND OF THE INVENTION Polycarbonates, polymethyl methacrylate, polyethylene terephthalate and the like have been known as resins having excellent transparency. This polycarbonate is excellent in rigidity, heat resistance, heat aging resistance, and impact resistance, but is inferior in chemical resistance, and has a large birefringence when molded into optical parts and used. Is also not sufficiently small. Polymethyl methacrylate has excellent mechanical properties, but has poor chemical resistance, heat resistance, and weather resistance.Polyethylene terephthalate has excellent heat resistance and mechanical properties. However, there is a problem that it has poor chemical resistance and is susceptible to hydrolysis.

Polyolefin is also known as a resin having excellent transparency, and a cyclic olefin polymer derived from a bulky cyclic olefin has been proposed as a polyolefin having a good balance between rigidity and transparency.
For example, as a random copolymer of this bulky cyclic olefin and ethylene, a copolymer of ethylene and 2,3-dihydroxydicyclopentadiene (US Pat. No. 2,883,
No. 372), or a copolymer of ethylene and 5-ethylidene norbornene.

The present applicant has also studied such a cyclic olefin-based polymer. In particular, an amorphous cyclic olefin-based polymer such as a copolymer of ethylene and a cyclic olefin has been found to have an α-olefin (co) polymer. Excellent in various properties compared to coalescence, such as transparency, low birefringence, moisture resistance (low water absorption), heat resistance, chemical resistance, solvent resistance, precision molding processability, dielectric properties, etc. It is found that it has excellent mechanical properties, mechanical properties and rigidity. For this reason, cyclic olefin-based polymers can be used for a wide variety of applications. In particular, by utilizing their excellent transparency, they can be used for, for example, optical applications, medical / pharmaceutical containers, and food containers. Is considered.

[0005] In recent years, printing and copying of a document once digitized by a computer, a scanner, or the like using a laser beam has been actively performed. This largely depends on the development of semiconductor lasers and their optical systems. Among optical systems,
A rotating polygon mirror (polygon mirror) that scans a laser beam and an fθ lens that condenses and forms an image of the reflected light are important.

The fθ lens is one of the toric lenses having a toric surface. The fθ lens converts a laser beam, which is reflected from a rotating polygon mirror and whose incident angle changes with time, on the screen at a constant scanning speed. Focus so that For the fθ lens, a transparent plastic material which is lightweight and has excellent moldability has been used. For example, polymethyl methacrylate, cyclic olefin polymers, and the like are used. However, polymethyl methacrylate has the above-mentioned problems, and a lens molded body made of these materials has a region where birefringence occurs in the periphery thereof, and the shape of condensed dots is formed into an elliptical shape. In some cases, the quality of printed matter is deteriorated due to image formation.

The cause of the birefringence is considered to be mainly the effect of the shearing force applied to the resin at the time of molding and the residual strain caused by shrinkage when the molding resin solidifies. This residual strain is often seen especially near the surface of the molded product, and therefore it is necessary to form a lens having a wide shape from a region to be used by passing a laser beam, and the thickness of the molded product also increases, During injection molding or injection compression molding, the cooling time until the molten resin solidifies becomes longer, and the productivity tends to decrease.

[0008]

SUMMARY OF THE INVENTION The present invention has been made under the above-mentioned background, and it is possible to narrow a region where harmful birefringence occurs near the surface of a lens molded body. It is an object of the present invention to provide a toric lens in which the width of a molded product is not unnecessarily increased and the cooling time is shortened to improve productivity.

[0009]

The toric according to the present invention
The lens has a stress optical coefficient C_RBut | C_R| ≦ 10^-9Pa ^-1
Consisting of a synthetic resin injection molded product satisfying
Laser with a maximum thickness of 5 mm or more with a rectangular cross section of L> W
A light beam lens, 2.8 mm from the end in the W direction
No interference fringes of 0.5 mm or less are observed in
It is characterized by:

In the present invention, the synthetic resin is at least one type of cyclic olefin polymer selected from the group consisting of the following [A-1], [A-2], [A-3] and [A-4]. It is preferable that they are united and have a stress optical coefficient C _R satisfying | C _R | ≦ 10 ⁻⁹ Pa ⁻¹ .

[A-1] α-olefin / cyclic olefin random obtained by copolymerizing an α-olefin having 2 to 20 carbon atoms with a cyclic olefin represented by the following formula (I) or (II): Copolymer,

Embedded image (In the formula, n is 0 or 1, m is 0 or an integer of 1 or more, q is 0 or 1, R ^{1 to} R ¹⁸ and R ^a and R ^b are each independently a hydrogen atom, a halogen atom or a hydrocarbon group, R ^{1 5} to R ¹⁸ may form a monocyclic or polycyclic bonded to each other, and also monocyclic or polycyclic have a double bond good, and R ¹ is ⁵ and the R ^{1 6,} or R ^{1 7} and R ^{1 8} and in may form an alkylidene group.)

[0012]

Embedded image (Where p and q are 0 or an integer of 1 or more;
And n is 0, 1 or 2, each R ¹ to R ^{1 9} independently represent a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group,
Alicyclic hydrocarbon group, an aromatic hydrocarbon group or an alkoxy group, the carbon atom to which R ⁹ and R ^{1 0} are attached,
The carbon atom to which R ^{1 3} or R ^{1 1} is bonded may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when the ^{n = m = 0, R 1} 5 and R ^{1 2} or R ^{1 5} and R ^{1 9} and may form a monocyclic or polycyclic aromatic ring bonded to each other. ),

[A-2] a ring-opened polymer or copolymer of a cyclic olefin represented by the above formula (I) or (II),
3] A hydride of the above-mentioned [A-2] ring-opening polymer or copolymer, and [A-4] a graft-modified product of the above [A-1], [A-2] or [A-3].

Further, in the present invention, the cyclic olefin polymer is preferably an ethylene / tetracyclododecene random copolymer.

Further, according to the present invention, there is provided an fθ lens formed from the synthetic resin.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The synthetic resin used in the present invention and a toric lens made of an injection molded article thereof will be specifically described below. The synthetic resin according to the present invention is a resin having transparency to a laser beam to be used, and has a stress optical coefficient C _R satisfying | C _R | ≦ 10 ⁻⁹ Pa ⁻¹ . Here, the stress optical coefficient is a constant inherent to a polymer relating to birefringence due to the orientation of the polymer chain, and the birefringence due to the orientation increases as this value increases. The stress optical coefficient is measured using a combination of a viscoelasticity measuring device and a birefringence measuring device. In the present invention, the transparency means that the light transmittance (according to ASTM D1003) is 70% or more,
Preferably it is 80% or more.

Examples of such a synthetic resin include polyolefins such as cyclic olefin polymers and polycyclohexylethylene, such as polyalicyclic ethylene and polycycloalkane, having an alicyclic hydrocarbon group in the main chain or side chain. Among the unions, those having a stress optical coefficient C _R satisfying | C _R | ≦ 10 ⁻⁹ Pa ⁻¹ are exemplified. Of these, the following cyclic olefin polymers are preferred. First, the cyclic olefin polymer will be described.

Cyclic Olefin Polymer In the present invention, [A-1]:
Α-olefin having 2 to 20 carbon atoms and the following formula (I)
Or a random copolymer with a cyclic olefin represented by (II), [A-2]: a ring-opened polymer or copolymer of a cyclic olefin represented by the following formula (I) or (II), -3]:
[A-2] a hydride of the ring-opened polymer or copolymer, and [A-4]: a graft-modified product of the above [A-1], [A-2] or [A-3]. At least one selected from the group is used.

The cyclic olefin polymer used in the present invention has a glass transition temperature (Tg) of 70 measured by DSC.
C. or higher, more preferably 70 to
The temperature is 250C, and particularly preferably 120 to 180C.

The cyclic olefin polymer used in the present invention is amorphous or low-crystalline and has a crystallinity, as measured by X-ray diffraction, of usually 20% or less, preferably 10% or less. %, More preferably 2% or less.

The intrinsic viscosity [η] of the cyclic olefin polymer measured in decalin at 135 ° C. is usually 0.0
1 to 20 dl / g, preferably 0.03 to 10 d
1 / g, more preferably 0.05 to 5 dl / g, and a melt flow index (melt flow rate; MFR) measured at 260 ° C. under a load of 2.16 kg according to ASTM D1238.
Is usually 0.1 to 200 g / 10 min, preferably 1 to 100 g / 10 min, more preferably 5 to 50 g / 1.
0 minutes.

Further, the softening point of the cyclic olefin polymer is determined by the softening point measured by a thermal mechanical analyzer.
(TMA) is usually 30 ° C. or higher, preferably 70 ° C. or higher, more preferably 80 to 260 ° C.

Among the polymers having these physical properties, a polymer having a low stress optical coefficient is characterized in that the monomer or comonomer is bulky in the side chain direction or has a high content of a comonomer that is bulky in the side chain direction. It is preferable to use

First, the general cyclic olefin represented by the formula (I) or (II) for forming the cyclic olefin polymer used in the present invention will be described. Cyclic olefin The cyclic olefin used in the present invention is represented by the following formula (I) or (II).

Embedded image

In the above formula (I), n is 0 or 1,
m is 0 or an integer of 1 or more, and q is 0 or 1. When q is 1, R ^a and R ^b are each independently an atom or a hydrocarbon group shown below, and q
Is 0, the respective bonds are combined to form a 5-membered ring.

R ^{1 to} R ¹⁸ and R ^a and R ^b are each independently a hydrogen atom, a halogen atom or a hydrocarbon group. Here, the halogen atom is a fluorine atom, a chlorine atom,
It is a bromine atom or an iodine atom.

The hydrocarbon groups each independently include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group. And the aromatic hydrocarbon group includes a phenyl group and a naphthyl group.
These hydrocarbon groups may be substituted with a halogen atom. In addition the above formula (I), the attached R ^{1 5} to R ¹⁸ are each (jointly with each other) may form a monocyclic or polycyclic, moreover, monocyclic or formed in this manner The polycyclic ring may have a double bond.

[0028]

Embedded image In the formula (II), p and q are 0 or an integer of 1 or more, and m and n are 0, 1 or 2. Also, R ^{1 to} R ^1
9 is each independently a hydrogen atom, a halogen atom, a hydrocarbon group or an alkoxy group.

The halogen atom has the same meaning as the halogen atom in the above formula (I). As the hydrocarbon group, each independently represents an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms,
15 cycloalkyl groups or aromatic hydrocarbon groups. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group. A cyclohexyl group is mentioned, and an aromatic hydrocarbon group is an aryl group and an aralkyl group, specifically, a phenyl group, a tolyl group, a naphthyl group, a benzyl group and a phenylethyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group and a propoxy group. These hydrocarbon groups and alkoxy groups may be substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

[0031] Here, the carbon atom to which R ⁹ and R ^{1 0} is attached, the carbon atom to which R ^{1 3} carbon atoms or R ^{1 1} are bonded is bonded, directly or number of carbon atoms 1 to
And 3 may be bonded via an alkylene group. That is, when the two carbon atoms are linked via an alkylene group, a group represented by R ⁹ and R ^{1 3} is, or a group represented by R ^{1 0} and R ^{1 1,} together jointly, a methylene group (-CH ₂ -), ethylene group (-CH ₂ CH ₂ -) or propylene group _{(-CH 2 CH 2 CH 2 -} ) to form one alkylene group of the.

Furthermore, when ^{n = m = 0, R 1} 5 and R ^{1 2} or R ^{1 5} and R ^{1 9} and may form an aromatic ring bonded to a monocyclic or polycyclic one another . As monocyclic or polycyclic aromatic ring in this case, for example, R ¹ as described below ⁵ and R ^{1 2}
Is a group further forming an aromatic ring.

[0033]

Embedded image Here, q has the same meaning as q in the formula (II).

The cyclic olefins represented by the above formula (I) or (II) are more specifically exemplified below.
As an example,

Embedded image (In the above general formula, the numbers 1 to 7 indicate the position numbers of carbon atoms) and a derivative obtained by substituting a hydrocarbon group for the compound. No.

As the substituted hydrocarbon group, 5-methyl, 5,
6-dimethyl, 1-methyl, 5-ethyl, 5-n-butyl, 5-isobutyl, 7-methyl, 5-phenyl, 5-methyl-5-phenyl, 5-benzyl, 5-tolyl, 5- (ethyl Phenyl), 5-
(Isopropylphenyl), 5- (biphenyl), 5- (β-naphthyl), 5- (α-naphthyl), 5- (anthracenyl), and 5,6-diphenyl.

Still other derivatives include cyclopentadiene-acenaphthylene adduct, 1,4-methano-1,4,4a, 9a-tetrahydrofluorene, 1,4-methano-1,4,4a, 5,10,10a -
Bicyclo [2.2.1] -2-heptene derivatives such as hexahydroanthracene can be exemplified.

In addition, tricyclo [4.3.0.1 ^2,5 ] -3-decene, 2-methyltricyclo [4.3.0.1 ^2,5 ] -3-decene, 5-methyltricyclo [4.3.0.1 ^2,5 ] -3-decene and other tricyclo [4.3.0.1 ^2,5 ] -3-decene derivatives, tricyclo [4.4.0.1
^2,5 ] -3-undecene, 10-methyltricyclo [4.4.0.1 ^2,5 ]
Tricyclo [4.4.0.1 ^2,5 ] -3-undecene derivatives such as -3-undecene,

Embedded image In tetracyclo shown [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene, and this hydrocarbon group include derivatives substituted.

The hydrocarbon groups include 8-methyl, 8-ethyl, 8-propyl, 8-butyl, 8-isobutyl, 8-hexyl, 8-cyclohexyl, 8-stearyl, 5,10-dimethyl, 2,10 -Dimethyl, 8,9-dimethyl, 8-ethyl-9-methyl, 11,12-dimethyl, 2,7,9-trimethyl, 2,7-dimethyl
-9-ethyl, 9-isobutyl-2,7-dimethyl, 9,11,12-trimethyl, 9-ethyl-11,12-dimethyl, 9-isobutyl-11,1
2-dimethyl, 5,8,9,10-tetramethyl, 8-ethylidene, 8
-Ethylidene-9-methyl, 8-ethylidene-9-ethyl, 8-ethylidene-9-isopropyl, 8-ethylidene-9-butyl, 8-
n-propylidene, 8-n-propylidene-9-methyl, 8-n-propylidene-9-ethyl, 8-n-propylidene-9-isopropyl, 8-n-propylidene-9-butyl, 8-isopropylidene, 8 -Isopropylidene-9-methyl, 8-isopropylidene-9-ethyl, 8-isopropylidene-9-isopropyl, 8-
Isopropylidene-9-butyl, 8-chloro, 8-bromo, 8-
Fluoro, 8,9-dichloro, 8-phenyl, 8-methyl-8-phenyl, 8-benzyl, 8-tolyl, 8- (ethylphenyl),
8- (isopropylphenyl), 8,9-diphenyl, 8- (biphenyl), 8- (β-naphthyl), 8- (α-naphthyl), 8- (anthracenyl), 5,6-diphenyl and the like are exemplified. be able to.

[0039] Furthermore, - tetracyclo such (cyclopentadiene acenaphthylene adduct) and adduct of cyclopentadiene [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene derivatives, pentacyclo [6.5.1.1 ^{3, 6.0 2,7} .0 ^9,13] -4-pentadecene and its derivatives, pentacyclo [7.4.0.1 ^2,5 .1
^9,12 .0 ^8,13] -3-pentadecene and its derivatives, pentacyclo ^{[8.4.0.1 2,5 .1 9,12 .0 8,13]} -3- hexadecene and derivatives thereof, pentacyclo [6.6.1.1 ^{3 , 6.0} 2,7.0 ^9,14 ]-
4-hexadecene and its derivatives, hexacyclo [6.6.
1.1 ^3,6 .1 ^10,13 .0 ^2,7 .0 ^9,14] -4-heptadecene and its derivatives, heptacyclo ^{[8.7.0.1 2,9 .1 4,7 .1 11,17 .0} 3, ⁸ .0
^12,16 ] -5-Eicosene and its derivatives, heptacyclo
^{[8.7.0.1 3,6 .1 10,17 .1 12,15 .0} 2,7 .0 11,16] -4- eicosene and its derivatives, heptacyclo [8.8.0.1 ^2,9 .1 ^4,7. 1
^11,18 .0 ^3,8 .0 ^12,17] -5-heneicosene and its derivatives, octacyclo ^{[8.8.0.1 2,9 .1 4,7 .1 11,18 .1} 13,16 .0
^3,8 .0 ^{12, 17} ] -5-docosene and its derivatives, nonacyclo
^{[10.9.1.1 4,7 .1 13,20 .1 15,18 .0} 2, 10 .0 3,8 .0 12,21 .0
^14,19] -5-pentacosene and derivatives thereof.

Specific examples of the above formula (I) or (II) which can be used in the present invention are as described above, and more specific structures of these compounds are described in the applicant's application. And paragraphs [0032] to [0054] of JP-A No. 7-145213, and in the present invention, those exemplified in the above specification may be used as the cyclic olefin of the present invention. it can.

As a method for producing the cyclic olefin represented by the general formula (I) or (II) as described above, for example,
A Diels-Alder reaction between cyclopentadiene and an olefin having a corresponding structure can be mentioned.

These cyclic olefins can be used alone or in combination of two or more. The cyclic olefin polymer used in the present invention can be prepared by using the cyclic olefin represented by the formula (I) or (II) as described above, for example, in JP-A-60-168708, JP-A-61-120816, Id 61
-115912, 61-115916, 61-271308, 61-2722
Nos. 16, 62-252406, 62-252407, etc., according to the method proposed by the present applicant, and by appropriately selecting conditions, it can be produced.

[A-1] α-olefin / cyclic olefin la
The random copolymer [A-1] α-olefin / cyclic olefin random copolymer contains 20 to 95 mol%, preferably 20 to 95 mol%, of structural units derived from α-olefin having 2 to 20 carbon atoms. In a quantity of 30 to 90 mol%, the structural unit derived from the cyclic olefin is usually 5 to 80 mol%, preferably 1 to 80 mol%.
It is contained in an amount of 0 to 70 mol%. The composition ratio of the α-olefin and the cyclic olefin is measured by ¹³ C-NMR.

Here, the α-olefin / cyclic olefin random copolymer [A-1] has 2 to 2 carbon atoms.
20 α-olefins will be described. The α-olefin may be linear or branched, and may be ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene , 1-octadecene, 1-eicosene and the like, linear α-olefins having 2 to 20 carbon atoms; 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4 -Methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl
-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-
Hexene, 3-ethyl-1-hexene, etc. with 4 carbon atoms
To 20 branched α-olefins. Among these, linear α-olefins having 2 to 4 carbon atoms are preferred, and ethylene is particularly preferred. Such linear or branched α-olefins can be used alone or in combination of two or more.

In this [A-1] α-olefin / cyclic olefin random copolymer, the number of carbon atoms is 2
Structural units derived from α-20 olefins and structural units derived from cyclic olefins are randomly arranged and bonded to have a substantially linear structure. The fact that the copolymer is substantially linear and does not have a substantially gel-like cross-linked structure means that when the copolymer is dissolved in an organic solvent, the solution contains an insoluble component. You can confirm by not having. For example, intrinsic viscosity [η]
Can be confirmed by completely dissolving this copolymer in decalin at 135 ° C.

In the [A-1] α-olefin / cyclic olefin random copolymer used in the present invention, at least a part of the cyclic olefin represented by the above formula (I) or (II) has the following formula (IV) ) Or (V).

[0047]

Embedded image In the formula (IV), n, m, q, R ^{1 to} R ¹⁸ and R ^a
And R ^b have the same meaning as in formula (I).

[0048]

Embedded image In formula (V), n, m, p, q and R ¹ to R ^{1 9} are the same meaning as in formula (II).

The [A-1] α-olefin / cyclic olefin random copolymer used in the present invention may be derived from other copolymerizable monomers as necessary within a range not to impair the object of the present invention. May be included.

Examples of such other monomers include olefins other than the above α-olefins having 2 to 20 carbon atoms or cyclic olefins. Specific examples include cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene and cyclooctene, 3a, 5,6,7a-tetrahydro-4,7-methano-
Cycloolefins such as 1H-indene, 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene, dicyclopentadiene and 5-vinyl-2- Non-conjugated dienes such as norbornene can be mentioned. These other monomers can be used alone or in combination.

[A-1] In the α-olefin / cyclic olefin random copolymer, the amount of the structural unit derived from the above other monomer is usually 20 mol% or less, preferably 10 mol% or less. May be contained.

The [A-1] α-olefin / cyclic olefin random copolymer used in the present invention has 2 carbon atoms.
To α-20 and a cyclic olefin represented by formula (I) or (II) by the production method disclosed in the above-mentioned publication. Among these, this copolymerization is carried out in a hydrocarbon solvent, and a catalyst formed from a vanadium compound and an organoaluminum compound soluble in the hydrocarbon solvent is used as a catalyst [A-
1] It is preferable to produce an α-olefin / cyclic olefin random copolymer.

In this copolymerization reaction, a solid group IV metallocene catalyst can also be used. Where solid IV
The group metallocene-based catalyst is a catalyst comprising a transition metal compound containing a ligand having a cyclopentadienyl skeleton, an organic aluminum oxy compound, and an organic aluminum compound optionally added. Here, the group IV transition metal is zirconium, titanium or hafnium, and these transition metals have a ligand containing at least one cyclopentadienyl skeleton. Examples of the ligand having a cyclopentadienyl skeleton include a cyclopentadienyl group or an indenyl group, a tetrahydroindenyl group, and a fluorenyl group which may be substituted with an alkyl group. These groups may be bonded via another group such as an alkylene group. Examples of the ligand other than the ligand having a cyclopentadienyl skeleton include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group.

As the organoaluminum oxy compound and the organoaluminum compound, those usually used for producing an olefin resin can be used. As such a solid group IV metallocene catalyst, those described in, for example, JP-A-61-221206, JP-A-64-106, and JP-A-2-173112 can be used.

[A-2] Ring-opened polymer of cyclic olefin or
Is a copolymer [A-2] a ring-opening polymer of a cyclic olefin or a copolymer is a ring-opening polymer of a cyclic olefin represented by the formula (I) or (II); And / or a copolymer containing a ring-opening polymerization unit of a cyclic olefin represented by (II). In the case of a copolymer, two or more different cyclic olefins are used in combination.

In the ring-opened polymer or ring-opened copolymer of cyclic olefin, at least a part of the cyclic olefin represented by the above formula (I) or (II) is represented by the following formula (VI) or (VII). It is considered to constitute a repeating unit to be performed.

Embedded image In the formula (VI), n, m, q and R ^{1 to} R ¹⁸ and R ^a and R ^b have the same meaning as in the formula (I).

[0057]

Embedded image In formula (VII), n, m, p, q and R ¹ to R ^{1 9} are the same meaning as in formula (II).

Such a ring-opening polymer or ring-opening copolymer can be produced by the production method disclosed in the above-mentioned publication, for example, by subjecting a cyclic olefin represented by the above formula (I) to ring-opening polymerization. It can be produced by polymerization or copolymerization in the presence of a catalyst. As the ring-opening polymerization catalyst, ruthenium, rhodium, palladium, osmium,
A catalyst comprising a metal halide selected from indium or platinum, a nitrate or acetylacetone compound and a reducing agent, or a metal halide or acetylacetone compound selected from titanium, palladium, zirconium or molybdenum, and an organoaluminum compound Can be used.

[A-3] Hydrogen of ring-opened polymer or copolymer
The hydride of the ring-opening polymer or copolymer [A-3] used in the present invention is obtained by converting the ring-opening polymer or copolymer [A-2] obtained as described above into a conventionally known hydrogen-containing compound. It is obtained by hydrogenation in the presence of an added catalyst.

In the hydride of the ring-opened polymer or copolymer [A-3], at least a part of the cyclic olefin represented by the formula (I) or (II) is represented by the following formula (VII)
It is considered to constitute the repeating unit represented by (I) or (IX).

[0061]

Embedded image In the formula (VIII), n, m, q and R ^{1 to} R ¹⁸ and R ^a and R ^b have the same meaning as in the formula (I).

[0062]

Embedded image N in formula (IX), m, p, q, R 1 ~R 1 9 formula (I
It has the same meaning as I).

[A-4] Graft Modified Product The graft modified product of the cyclic olefin-based polymer is the above-mentioned [A-1] α-olefin / cyclic olefin random copolymer, [A-2] ring-opening of cyclic olefin. It is a graft-modified product of a polymer or copolymer, or a hydride of [A-3] a ring-opening polymer or copolymer.

Examples of the modifier used herein include unsaturated carboxylic acids. Specific examples thereof include (meth) acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid and the like. , Isocrotonic acid, endocis-bicyclo [2.2.1] hept-5-ene-
Unsaturated carboxylic acids such as 2,3-dicarboxylic acid (Nadic acid ^TM ), and derivatives of these unsaturated carboxylic acids such as unsaturated carboxylic anhydrides, unsaturated carboxylic halides,
Examples thereof include unsaturated carboxylic acid amides, unsaturated carboxylic acid imides, and unsaturated carboxylic acid ester compounds.

As the derivatives of unsaturated carboxylic acids, more specifically, maleic anhydride, citraconic anhydride, maleyl chloride, maleimide, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like can be mentioned.

Of these, α, β-unsaturated dicarboxylic acids and α, β-unsaturated dicarboxylic anhydrides such as maleic acid, nadic acid and anhydrides of these acids are preferably used. These modifiers can be used in combination of two or more.

Such a graft-modified product of a cyclic olefin polymer can be produced by blending a modifier with the cyclic olefin polymer so as to obtain a desired modification rate and graft-polymerizing the same, or it can be prepared in advance by a high modification. The modified product may be prepared by preparing a modified product having a desired modification ratio, and then mixing the modified product with an unmodified cyclic olefin-based polymer so as to obtain a desired modification ratio.

In order to obtain a graft-modified product of a cyclic olefin polymer from a cyclic olefin polymer and a modifier, a conventionally known polymer modification method can be widely applied. For example, a graft modified product is obtained by adding a modifying agent to a cyclic olefin polymer in a molten state and performing graft polymerization (reaction), or by adding a modifying agent to a solvent solution of the cyclic olefin polymer and performing a graft reaction. Can be obtained.

Such a graft reaction is usually carried out at 60 to 3
It is performed at a temperature of 50 ° C. The graft reaction can be performed in the presence of a radical initiator such as an organic peroxide and an azo compound.

In the present invention, the above-mentioned [A-1], [A-2], [A-3] and [A-3]
-4] can be used alone, or can be used in combination. Among them, α-olefin / cyclic olefin random copolymer [A-1], and further, ethylene / cyclic olefin random copolymer are preferably used. In particular, ethylene
Tetracyclododecene random copolymer is preferred.

In the present invention, a resin composition obtained by blending another resin with the above-mentioned cyclic olefin polymer, if necessary, can be used. Other resins are added within a range that does not impair the purpose of the present invention. Here, the polymer (resin component) that can be added to the cyclic olefin polymer is exemplified below.

Other Resin Components That Can Be Added (1) A polymer derived from a hydrocarbon having one or two unsaturated bonds. Specifically, for example, polyethylene,
Polyolefins such as polypropylene, polymethylbutene-1, poly4-methylpentene-1, polybutene-1, and polystyrene. These polyolefins may have a crosslinked structure.

(2) Halogen-containing vinyl polymer. Specific examples include polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polychloroprene, and chlorinated rubber.

(3) Polymers derived from α, β-unsaturated acids and their derivatives. Specifically, polyacrylate, polymethacrylate, polyacrylamide, polyacrylonitrile, or a copolymer with a monomer constituting the polymer, for example, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, acrylonitrile Styrene / acrylate copolymers and the like can be mentioned.

(4) Polymers derived from unsaturated alcohols and amines, or acyl derivatives of unsaturated alcohols or acetals. Specifically, polyvinyl alcohol, polyvinyl acetate, polyvinyl polythreate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, polyallyl phthalate, polyallyl melamine,
Alternatively, a copolymer with a monomer constituting the polymer, such as an ethylene / vinyl acetate copolymer, may be used.

(5) A polymer derived from an epoxide. Specific examples include a polymer derived from polyethylene oxide or bisglycidyl ether.

(6) Polyacetal. Specific examples thereof include polyoxymethylene, polyoxyethylene, and polyoxymethylene containing ethylene oxide as a comonomer.

(7) Polyphenylene oxide. (8) Polycarbonate. (9) Polysulfone. (10) Polyurethane and urea resins.

(11) Diamine and dicarboxylic acid and / or
Or polyamides and copolyamides derived from aminocarboxylic acids or the corresponding lactams. Specifically, nylon 6, nylon 66, nylon 11, nylon 1
2 and the like.

(12) Polyesters derived from dicarboxylic acids and dialcohols and / or oxycarboxylic acids or the corresponding lactones. Specifically, polyethylene terephthalate, polybutylene terephthalate, poly 1,
4-dimethylol and cyclohexane terephthalate.

(13) A polymer having a crosslinked structure derived from aldehyde and phenol, urea or melamine. Specifically, phenol / formaldehyde resin, urea / formaldehyde resin, melamine / formaldehyde resin and the like can be mentioned.

(14) Alkyd resin. Specific examples include glycerin / phthalic acid resin. (15) An unsaturated polyester resin derived from a copolyester of a saturated and unsaturated dicarboxylic acid and a polyhydric alcohol and obtained by using a vinyl compound as a crosslinking agent, and a halogen-containing modified resin.

(16) Natural polymers. Specifically, cellulose,
Examples include rubber, protein, and derivatives thereof such as cellulose acetate, cellulose propionate, and cellulose ether.

(17) Flexible polymer. For example, a soft polymer containing a cyclic olefin component, an α-olefin-based copolymer,
Examples include olefin / diene-based copolymers, aromatic vinyl hydrocarbon / conjugated diene-based soft copolymers, and soft polymers or copolymers of isobutylene or isobutylene / conjugated diene.

Other Additives The cyclic olefin polymer used in the present invention may further contain, in addition to the components described above, known weather stabilizers, heat stabilizers, antistatic agents, and the like, as long as the object of the invention is not impaired. Flame retardants, slip agents, anti-blocking agents, anti-fogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, organic or inorganic fillers and the like may be incorporated.

For example, as a UV absorber of a weathering stabilizer incorporated as an optional component, a benzophenone compound, a benzotriazole compound, a nickel compound,
There are hindered amine compounds, specifically, 2,2 ',
4,4'-tetrahydroxybenzophenone, 2- (2'-hydroxy-3'-t-butyl-5'-butylphenyl) -5-chlorobenzotriazole and 2- (2'-hydroxy-3'-t- Butyl-5'-butylphenyl) benzotriazole, nickel salt of bis (3,5-di-t-butyl-4-hydroxybenzoylphosphonic acid ethyl ester, bis (2,2 ', 6,6'-tetra Methyl-4-piperidine) sebacate and the like.

The heat stabilizer incorporated as an optional component includes tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane.
β- (3,5-di-t-butyl-4-hydroxyphenyl) propionic acid alkyl ester, 2,2′-oxamidobis [ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) Phenolic antioxidants such as propionate, fatty acid metal salts such as zinc stearate, calcium stearate, calcium 1,2-hydroxystearate, glycerin monostearate, glycerin distearate, pentaerythritol monostearate, pentaerythritol distearate And polyhydric alcohol fatty acid esters such as pentaerythritol tristearate, and the like, and also distearyl pentaerythritol diphosphite, phenyl-4,4'-isopropylidene diphenol-pentaerythritol diphosphite, bis
Phosphorus stabilizers such as (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite may be used. These may be blended alone or in combination. For example, tetrakis [methylene-3- (3.5-
Di-t-butyl-4-hydroxyphenyl) propionate]
Examples include a combination of methane, zinc stearate, and glycerin monostearate. These stabilizers can be used alone or in combination of two or more.

As a method for mixing the cyclic olefin polymer used in the present invention with other resin components and additives, a method known per se can be applied. For example, there is a method of simultaneously mixing the components.

Toric Lens The toric lens according to the present invention has a length L and a width W, where L> L.
This lens has a toric surface having a rectangular cross section of W and a maximum thickness H of 5 mm or more. An example is shown in FIG. The size of the toric lens of the present invention is usually L ≧ 50 mm,
It is desirable that W ≧ 5 mm and (H / W) ≧ 0.6. In the present invention, it is preferable that the toric lens is an fθ lens.

FIG. 2 is an explanatory diagram showing interference fringes appearing when visible light is transmitted from the H direction (optical axis direction) of the lens and the surface A in FIG. 1 is observed using a polariscope. Birefringence occurs in an area where the interference fringes appear densely, and the shape of dots transmitted through this area and condensed forms an elliptical shape, thereby deteriorating the quality of printed matter in a laser printer or the like. . In the toric lens of the present invention, the distance from the end in the W direction (a in FIG. 2) is 2.8.
mm, preferably at 2.5 mm, more preferably at 2 mm, dense interference fringes with a spacing of 0.5 mm or less are not observed, and the area where birefringence occurs can be narrowed compared to conventional products, so that molded products It is not necessary to increase the width of the toric lens, and the cooling time can be shortened, and the molding productivity of the toric lens can be increased.

The toric lens of the present invention can be obtained by injection molding or injection compression molding of the above synthetic resin. As a method for producing the injection molded body, any known method can be adopted.

The toric lens as described above transmits laser light such as a lens used in a printer such as an fθ lens and an arc-sin lens, a lens used in a copying machine, a projection lens of office equipment, and a plastic lens for medical examination. Used for parts and other applications.

[0093]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.
In addition, the physical property measuring method in an Example is shown below. (1) Melt flow index (MFR) 260 ° C., load 2.16 k according to ASTM D1238
g. (2) Glass transition temperature (Tg) The glass transition temperature was measured at a heating rate of 10 ° C./min using SEIKO Electronics Co., Ltd. DSC-20. (3) Stress optical coefficient (C _R ) A viscoelasticity measuring device was combined with a birefringence measuring device, and hot press-molded at Tg + 100 ° C. of the resin, thickness 0.5 m
The complex elastic modulus (E _R ^* ) and the strain optical ratio (O _R ^* ) were simultaneously measured in an atmosphere of Tg + 10 to Tg + 30 ° C. using a press sheet of m, and the stress optical coefficient C _R was calculated by the following equation. C _R = O _R ^* / E _R ^*

Example 1 Ethylene / tetracyclododecene random copolymer (E.TD (1)) obtained using a Ziegler catalyst (tetracyclododecene unit content: 3)
7 mol%, MFR: 42 g / 10 min, Tg: 130 ° C.
Using a stress optical coefficient: 3 × 10 ⁻¹⁰ Pa ⁻¹ ) and an injection molding machine (IS-50EP manufactured by Toshiba Machine Co., Ltd.), 80 (L) at a cylinder temperature of 290 ° C. and a mold temperature of 120 ° C. ) mm
A test piece of × 30 (H) mm × 10 (W) mm was injection molded. This test piece was irradiated with visible light from the H direction, and observed from the opposite side using a polariscope (MODEL PS-5 manufactured by RIKEN KEIKI). The interval between the interference fringes was 0.5 mm or less.
The distance from the end in the direction (a in FIG. 2) was measured with a caliper. Table 1 shows the results.

Example 2 Ethylene / tetracyclododecene random copolymer (E · TD (2)) (tetracyclododecene unit content: 30 mol%, MFR: 22 g / 10
Min, Tg: 105 ° C., stress optical coefficient: 5 × 10 ⁻¹⁰ Pa
^{Using -1} ), a test piece was molded and evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 Polycarbonate (Teijin Co., Ltd.)
AD5503), the cylinder temperature was 320 ° C,
Evaluation was performed in the same manner as in Example 1 except that injection molding was performed at a mold temperature of 130 ° C. Table 1 shows the results.

[0097]

[Table 1]

[0098]

According to the toric lens made of the injection molded article of the present invention, the area where harmful birefringence occurs near the surface of the molded article can be narrowed. As a result, the width of the molded article can be increased more than necessary. Thus, it is possible to provide a toric lens having improved productivity by shortening the cooling time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a toric lens according to the present invention.

FIG. 2 is an explanatory diagram showing interference fringes that appear when the plane A in FIG. 1 is observed with a polariscope.

[Explanation of symbols]

 L Length of toric lens W Width of toric lens H Maximum thickness of toric lens 1 Optical axis of toric lens 2 Interference fringes a Distance from end of dense portion of interference fringes

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08F 255/00 C08F 255/00 277/00 277/00 283/14 283/14 C08G 61/08 C08G 61 / 08 G02B 1/04 G02B 1/04 // B29K 23:00 45:00 B29L 11:00

Claims (4)

[Claims] 1. The stress optical coefficient C _R is | C _R | ≦ 10 ^-9 P
a- ¹ consisting of an injection molded body of a synthetic resin satisfying a- ¹
A laser beam lens having a width W and a rectangular cross section of L> W and having a maximum thickness of 5 mm or more, which is 2.8 from the end in the W direction.
A toric lens characterized in that no interference fringes of 0.5 mm or less are observed in mm. 2. The synthetic resin according to the following [A-1], [A-
2], [A-3] and [comprises at least one cyclic olefin polymer selected from the group consisting of A-4], the stress optical coefficient C _{R ^{is, | C R | ≦ 10 -9}} Pa -1 [A-1] A copolymer of an α-olefin having 2 to 20 carbon atoms and a cyclic olefin represented by the following formula (I) or (II): Α-olefin / cyclic olefin random copolymer obtained by (In the formula, n is 0 or 1, m is 0 or an integer of 1 or more, q is 0 or 1, R ^{1 to} R ¹⁸ and R ^a and R ^b are each independently a hydrogen atom, a halogen atom or a hydrocarbon group, R ^{1 5} to R ¹⁸ may form a monocyclic or polycyclic bonded to each other, and also monocyclic or polycyclic have a double bond good, and R ¹ is ⁵ and the R ^{1 6,} or R ^{1 7} and R ^{1 8} and in may form an alkylidene group.) [Chemical Formula 2] (Where p and q are 0 or an integer of 1 or more;
And n is 0, 1 or 2, each R ¹ to R ^{1 9} independently represent a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group,
Alicyclic hydrocarbon group, an aromatic hydrocarbon group or an alkoxy group, the carbon atom to which R ⁹ and R ^{1 0} are attached,
The carbon atom to which R ^{1 3} or R ^{1 1} is bonded may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when the ^{n = m = 0, R 1} 5 and R ^{1 2} or R ^{1 5} and R ^{1 9} and may form a monocyclic or polycyclic aromatic ring bonded to each other. ), [A-2] a ring-opening polymer or copolymer of a cyclic olefin represented by the above formula (I) or (II), [A-3] a ring-opening polymer or copolymer of the above [A-2]. [A-4] a graft-modified product of the above [A-1], [A-2] or [A-3]. 3. The toric lens according to claim 2, wherein the cyclic olefin polymer is an ethylene / tetracyclododecene random copolymer. 4. The toric lens according to claim 1, wherein said lens is an fθ lens.