JPH1087752A - Cyclic olefin-based resin pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject pellet hardly causing undesirable black spots and burn marks in producing a molding article by using a melting and molding apparatus, comprising a specific cyclic olefinic resin which is produced in an inert gas atmosphere and maintained in an inert gas atmosphere. SOLUTION: This pellet is produced in an inert gas atmosphere, maintained in an inert gas atmosphere under <=0.1atm oxygen partial pressure and comprises a cyclic olefinic resin selected from (A) an ethylene/cyclic olefin random copolymer obtained by copolymerizing ethylene with a cyclic olefin of formula I ((n) is 0 or 1; (m) is 0 or a positive integer; (q) is 0 or 1; R<1> to R<18> , R<a> and R<6> are each H, a halogen, a hydrocarbon and R" to R" may be mutually bonded to form a monocyclic or a polycyclic ring) or formula II ((p) and (q) are each >=0; (m) and (n) are each 0-2; R<1> to R<19> are each H, a halogen, an alicyclic hydrocarbon, an aromatic hydrocarbon, etc.), (B) a cyclic olefin ring-opened polymer or copolymer of formula I or formula II, (C) a hydrogenated substance of the component B and (D) a grafted modified substance of the components A to C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cyclic olefin resin pellet which is less likely to burn during molding.

[0002]

BACKGROUND OF THE INVENTION Cyclic olefin resins are resins having excellent optical properties. That is, this cyclic olefin-based resin has excellent transparency, low birefringence, and optical properties such as high Abpe number and high refractive index, and is expected to be applied to optical applications.

However, when the cyclic olefin resin is melted and molded, black spot defects may occur with a relatively small number of shots. Since the cyclic olefin-based resin is a resin having high transparency, it is often used for applications utilizing the transparency of the cyclic olefin-based resin, and a molded article having such black spots is a defective product.

The present inventor has studied the cause of such black spot defects and found that oxygen contained in the pellets is deeply involved in the generation of black spot defects. In order to prevent the occurrence of black spot defects, it is necessary to frequently clean the apparatus (melt molding machine) for melting the cyclic olefin-based resin.

[0005] However, if the melt molding machine is frequently stopped, the productivity is reduced.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cyclic olefin-based resin pellet in which black spot defects are less likely to occur when a molded article is produced from a cyclic olefin-based resin using a melt molding apparatus.

[0007]

SUMMARY OF THE INVENTION The cyclic olefin-based resin pellet of the present invention comprises a cyclic olefin-based resin selected from the group consisting of the following [I-1], [I-2], [I-3] and [I-4]. Pellets produced in an inert gas atmosphere and stored in an inert gas atmosphere having an oxygen partial pressure of 0.1 atm or less.

[I-1] An ethylene / cyclic olefin random copolymer obtained by copolymerizing ethylene with a cyclic olefin represented by the following formula [I] or [II];
2] a ring-opening polymer or copolymer of a cyclic olefin represented by the following formula [I] or [II], [I-3] a hydride of the above [I-2] ring-opening polymer or copolymer, And [I-4] a graft-modified product of the above [I-1], [I-2] or [I-3].

[0009]

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In the above formula [I], n is 0 or 1,
m is 0 or a positive integer, 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 ¹⁵ to R ¹⁸ may form a monocyclic or polycyclic bonded to each other, and may be monocyclic or polycyclic have a double bond, also R ¹⁵ and R ¹⁶ Or R ¹⁷ and R ¹⁸ may form an alkylidene group.

[0011]

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In the above formula [II], p and q are 0 or 1
M and n are 0, 1 or 2, and R ^{1 to} R ¹⁹ are each independently a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon. R ⁹ (or R ¹⁰ )
And the carbon atom to which R ¹³ or R ¹¹ is bonded may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and n = m = 0 In this case, R ¹⁵ and R ¹² or R ¹⁵ and R ¹⁹ may be bonded to each other to form a monocyclic or polycyclic aromatic ring.

In general, when molding a resin, when the molding temperature is increased, burns are generated inside the molding machine, and the burns grow and mix into the molded body to form black spots. However, as a result of examining the cause of the occurrence of black spot defects in the cyclic olefin-based resin, in the cyclic olefin-based resin, air is dissolved in the pellets, and the generation of burns is promoted by this air, particularly oxygen in the air. . That is, as far as the molding of the cyclic olefin resin is concerned, the black point is not merely a matter of the molding temperature, but the amount of the black spot varies significantly depending on the amount of oxygen contained in the cyclic olefin resin pellet.

In the present invention, the occurrence of black spots is suppressed by reducing the oxygen partial pressure contained in the cyclic olefin resin pellets to a certain value or less. Further, the size of the cyclic olefin-based resin pellet may also affect the occurrence of black spots, and the pellet is stored in an environment where the oxygen partial pressure in the cyclic olefin-based resin pellet can be maintained at a predetermined value or less as described above. In addition, by making the cyclic olefin resin pellets a predetermined size or less,
The effect of lowering the oxygen partial pressure becomes more remarkable.

[0015]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for producing a molded article from the cyclic olefin resin of the present invention will be specifically described.

The cyclic olefin resin pellet of the present invention is a pellet comprising a cyclic olefin resin selected from the group consisting of the following [I-1], [I-2], [I-3] and [I-4]. It is necessary that the pellets are produced in an inert gas atmosphere.

[I-1] An ethylene / cyclic olefin random copolymer obtained by copolymerizing ethylene and a cyclic olefin represented by the following formula [I] or [II];
2] a ring-opening polymer or copolymer of a cyclic olefin represented by the following formula [I] or [II], [I-3] a hydride of the above [I-2] ring-opening polymer or copolymer, And [I-4] a graft-modified product of the above [I-1], [I-2] or [I-3].

This cyclic olefin-based resin has the above-mentioned [I-
The cyclic olefin-based resin of [1], [I-2], [I-3] and [I-4] may be used alone or a resin composition composed of a mixture thereof.

The degree of crystallinity of the cyclic olefin resin used in the present invention, as measured by X-ray diffraction, is usually 20% or less, preferably 10% or less. The cyclic olefin resin has an intrinsic viscosity [η] measured in decalin at 135 ° C. of usually 0.01 to 20 dl / g, preferably 0.03 to 10 dl / g, more preferably 0.05.
８8 dl / g.

The iodine value of such a cyclic olefin resin is usually 5 or less, more often 1 or less. Here, the cyclic olefin cyclic olefin represented by the formula [I] or [II] that forms the cyclic olefin resin used in the present invention will be described.

The cyclic olefin used for preparing the cyclic olefin resin can be represented by the following formula [I] or [II].

[0022]

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In the above formula [I], n is 0 or 1,
m is 0 or a positive integer, and q is 0 or 1.
When q is 1, R ^a and R ^b are each independently the following atoms or hydrocarbon groups. When q is 0, each bond is bonded to form a 5-membered ring. Form.

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, a bromine atom or an iodine atom.

Examples of the hydrocarbon group independently include an alkyl group usually 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. Is a cyclohexyl group, and the aromatic hydrocarbon group is a phenyl group, a naphthyl group or the like.

These hydrocarbon groups may be substituted with a halogen atom. Further, in the above formula [I], R
^{15 to} R ¹⁸ may be bonded to each other (together with each other) to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring thus formed has a double bond. Is also good. The monocyclic or polycyclic rings formed here are specifically exemplified below.

[0027]

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In the formula [II], p and q are 0 or a positive integer, and m and n are 0, 1 or 2. Also R
^{1 to} R ¹⁹ are each independently a hydrogen atom, a halogen atom,
It is a hydrocarbon group or an alkoxy group.

The halogen atom has the same meaning as the halogen atom in the above formula [I]. Further, as the hydrocarbon group, each independently an alkyl group having 1 to 20 carbon atoms,
Examples thereof include a halogenated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, as the alkyl group, 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;
Examples of the cycloalkyl group include a cyclohexyl group, and examples of the aromatic hydrocarbon group include an aryl group and an aralkyl group, specifically, a phenyl group, a tolyl group, a naphthyl group, a benzyl group, and a phenylethyl group. Can be mentioned.

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.

Here, the carbon atom to which R ⁹ and R ¹⁰ are bonded and the carbon atom to which R ¹³ is bonded or the carbon atom to which R ¹¹ is bonded are directly or a carbon atom having 1 to 1 carbon atoms.
And 3 may be bonded via an alkylene group. That is, when the two carbon atoms are bonded via an alkylene group, the groups represented by R ⁹ and R ¹³ , or the groups represented by R ¹⁰ and R ¹¹ cooperate with each other, 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.

Further, when n = m = 0, R ¹⁵ and R ¹² or R ¹⁵ and R ¹⁹ may combine with each other to form a monocyclic or polycyclic aromatic ring. In this case, as the monocyclic or polycyclic aromatic ring, for example, the following n = m = 0
In this case, there can be mentioned groups in which R ¹⁵ and R ¹² further form an aromatic ring.

[0033]

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Here, q has the same meaning as q in the formula [II]. The cyclic olefin represented by the above formula [I] or [II] is more specifically exemplified below.

Examples of the cyclic olefin forming the cyclic olefin resin include:

[0036]

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(In the above general formula, the numbers 1 to 7 indicate the position numbers of carbon atoms), and the compound has a hydrocarbon group in the bicyclo [2.2.1] -2-heptene (= norbornene). Substituted derivatives can be mentioned.

The hydrocarbon group includes 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- (ethylphenyl) ,Five-
(Isopropylphenyl), 5- (biphenyl), 5- (β-
Naphthyl), 5- (α-naphthyl), 5- (anthracenyl),
Groups such as 5,6-diphenyl can be exemplified.

Still other derivatives include cyclopentadiene-acenaphthylene adduct, 1,4-methano-1,4,4a, 9a-
Tetrahydrofluorene, 1,4-methano-1,4,4a, 5,10,10
Bicyclo [2.2.1]-such as a-hexahydroanthracene
A 2-heptene derivative 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
- tricyclo [4.3.0.1 ^2,5] -3- decene derivatives such as methyl tricyclo [4.3.0.1 ^2,5] -3- decene, tricyclo [4.4.0.1 ^2,5] -3- undecene, 10-methyl Tricyclo [4.4.0.1 ^2,5 ] -3-undecene and other tricyclo [4.4.
0.1 ^2,5 ] -3-undecene derivatives,

[0041]

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Tetracyclo [4.4.0.1 ^2,5 .1 represented by the [0042]
^7,10 ] -3-dodecene, a derivative obtained by substituting the compound with a hydrocarbon group, and a compound obtained by substituting at least a part of a hydrogen atom with another atom.

Here, as a hydrocarbon group or a substituent atom,
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, 9.1
1,12-trimethyl, 9-ethyl-11,12-dimethyl, 9-isobutyl-11,12-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-Propilidene-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 Examples can be given.

[0044] 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 derivatives thereof, 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, Nonashikuro [10.9.1.1 ^4,7 .1 ^{13, 20} .1 ^{15 and 18} .0
^2,10 .0 ^3,8 .0 ^12,21 .0 ^14,19] such as 5-pentacosene and its derivatives.

The specific examples of the cyclic olefin represented by the formula [I] or [II] which can be used in the present invention are as described above. Japanese Patent Application No. 196475/1993
In the present invention, those described in paragraph numbers [0032] to [0054] and exemplified in the present invention can be used as the cyclic olefin in the present invention.

The cyclic olefin represented by the above formula [I] or [II] can be produced by a Diels-Alder reaction between cyclopentadiene and an olefin having a corresponding structure.

These cyclic olefins can be used alone or in combination of two or more. The cyclic olefin resin 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 and JP-A-61-120816.
-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.

[I-1] The ethylene / cyclic olefin random copolymer is composed of a structural unit derived from ethylene in an amount of usually 20 to 95 mol%, preferably 30 to 90 mol%, derived from a cyclic olefin. The unit of construction is usually 5
It is contained in an amount of .about.80 mol%, preferably 10-70 mol%. The composition ratio of ethylene and cyclic olefin is measured by ¹³ C-NMR.

In this [I-1] ethylene / cyclic olefin random copolymer, the structural units derived from ethylene and the structural units derived from cyclic olefin are randomly arranged and bonded, It has 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, when the intrinsic viscosity [η] is measured, this copolymer is 135
It can be confirmed by complete dissolution in decalin at ° C.

In the [I-1] ethylene / cyclic olefin random copolymer used in the present invention, the cyclic olefin represented by the above formula [I] or [II] is represented by the following formula [II]
It is considered to constitute a repeating unit represented by [I] or [IV].

[0051]

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In the above formula [III], n, m, q and R ^{1 to} R ¹⁸ and R ^a and R ^b have the same meaning as in the formula [I].

[0053]

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In the above formula [IV], n, m, p, q and R ^{1 to} R ¹⁹ have the same meaning as in the formula [II]. Further, the [I-1] ethylene / cyclic olefin random copolymer used in the present invention has a structural unit derived from another copolymerizable monomer as needed within a range not to impair the object of the present invention. May be.

Examples of such other monomers include olefins other than the above-mentioned ethylene or cyclic olefin, and specific examples thereof include propylene, 1-butene, 1-pentene, 1-hexene and 3-olefin. 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, 1-octene , 1-decene, 1-
Α- having 3 to 20 carbon atoms such as dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene
Olefin, 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.

These other monomers can be used alone or in combination. [I-1] In the ethylene / cyclic olefin random copolymer, the constituent unit derived from the other monomer as described above is usually contained in an amount of 20 mol% or less, preferably 10 mol% or less. Is also good.

The [I-1] ethylene / cyclic olefin random copolymer used in the present invention is prepared by using ethylene and a cyclic olefin represented by the formula [I] or [II] as disclosed in the above publication. It can be manufactured by a method.
Among these, this copolymerization is carried out in a hydrocarbon solvent, and using a catalyst formed from a vanadium compound and an organoaluminum compound soluble in the hydrocarbon solvent as a catalyst, [I-1] ethylene / cyclic olefin random copolymer is used. It is preferred to produce a polymer.

In this copolymerization reaction, a solid group IVB metallocene catalyst can also be used. Where solid IV
The group B 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 VI transition metal is zirconium, titanium or hafnium, and these transition metals have at least one ligand having a cyclopentadienyl skeleton. here,
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 by an alkyl group. These groups may be bonded via another group such as an alkylene group. Further, ligands other than the ligand having a cyclopentadienyl skeleton include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group and the like.

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

[I-2] In the ring-opened polymer or ring-opened copolymer of cyclic olefin, the cyclic olefin represented by the above formula [I] or [II] is represented by the following formula [V] or [VI] It is considered to constitute the repeating unit represented.

[0061]

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In the above formula [V], n, m, q and R ^{1 to} R ¹⁸ and R ^a and R ^b have the same meaning as in the formula [I].

[0063]

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In the above formula [VI], n, m, p, q and R ^{1 to} R ¹⁹ have the same meaning as in the formula [II]. Such a ring-opening polymer or a ring-opening copolymer can be produced by the production method disclosed in the above-mentioned gazette. It can be produced by polymerization or copolymerization below.

Examples of such a ring-opening polymerization catalyst include a catalyst comprising a halide, nitrate or acetylacetone compound of a metal such as ruthenium, rhodium, palladium, osmium, indium or platinum, and a reducing agent.
Alternatively, a catalyst comprising a halide or acetylacetone compound of a metal such as titanium, palladium, zirconium or molybdenum and an organoaluminum compound can be used.

The hydride of the ring-opening polymer or copolymer [I-3] used in the present invention can be obtained by synthesizing the ring-opening polymer or copolymer [I-2] obtained as described above. By hydrogenation in the presence of a hydrogenation catalyst.

In the hydride of the ring-opened polymer or copolymer [I-3], the cyclic olefin represented by the formula [I] or [II] is represented by the following formula [VII] or [VIII]. Is considered to have a repeating unit.

[0068]

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In the above formula [VII], n, m, q and R ^{1 to} R ¹⁸ and R ^a and R ^b have the same meaning as in the formula [I].

[0070]

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In the above formula [VIII], n, m, p,
q and R ^{1 to} R ¹⁹ have the same meaning as in formula [II]. [I-4] The graft-modified product of the cyclic olefin-based resin is the above-mentioned [I-1] ethylene / cyclic olefin random copolymer, [I-2] a cyclic olefin ring-opening polymer or copolymer, or [I-2]. I-3] It is a graft modified product of a hydride of a ring-opened polymer or copolymer.

As the modifier, unsaturated carboxylic acids are usually used. Examples of the unsaturated carboxylic acids used here include (meth) acrylic acid, maleic acid,
Fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and endocis
Unsaturated carboxylic acids such as -bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid (Nadic acid ^™ ), and
Derivatives of these unsaturated carboxylic acids, for example, unsaturated carboxylic anhydrides, unsaturated carboxylic acid halides, unsaturated carboxylic acid amides, unsaturated carboxylic imides and ester compounds of unsaturated carboxylic acids can be mentioned.

Specific examples of the derivative of the unsaturated carboxylic acid include maleic anhydride, citraconic anhydride, maleenyl chloride, maleimide, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like.

Among these modifiers, 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 kinds.

The modification rate of the graft-modified cycloolefin resin used in the present invention is desirably 10 mol% or less. Such a graft modified product of a cyclic olefin-based resin can be produced by blending a modifier with a cyclic olefin-based resin so as to have a desired modification rate and graft-polymerizing the same, or a modified product having a high modification rate in advance. And then mixing this modified product with an unmodified cyclic olefin-based resin.

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

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, as the cyclic olefin-based resin, [I-1], [I-2], [I-3] and [I-3]
-4] can be used alone, or can be used in combination.

Of these, an ethylene / cyclic olefin random copolymer [I-1] is preferably used. In addition, the cyclic olefin resin used in the present invention includes, in addition to the resins [I-1], [I-2], [I-3] and [I-4], the cyclic olefin resin As long as the properties are not impaired, other resins may be blended, for example, a resin such as a soft polymer such as polyvinyl chloride rubber, which does not impair properties such as transparency.

The cyclic olefin-based resin used in the present invention further comprises a conventionally known heat stability, weather resistance, antistatic agent, slip agent, antiblocking agent, antifogging agent,
Lubricants, dyes, pigments, natural oils, synthetic oils, waxes and the like may be blended.

The stabilizer can be blended with the resin before forming the pellets and contained in the pellets, or the resin can be formed into pellets and then added to the pellets and mixed.

In the present invention, for example, 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′-oxamidebis [Phenolic antioxidants such as ethyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, zinc stearate, calcium stearate, 1,2-
Examples include fatty acid metal salts such as calcium hydroxystearate, and polyhydric alcohol fatty acid esters such as glycerin monostearate, glycerin distearate, pentaerythritol monostearate, pentaerythritol distearate, and pentaerythritol tristearate. These may be blended alone or in combination. For example, a combination of tetrakis [methylene-3- (3.5-di-t-butyl-4-hydroxyphenyl) propionate] methane, zinc stearate and glycerin monostearate can be exemplified. These stabilizers can be used alone or in combination of two or more.

Examples of the organic or inorganic filler include silica, diatomaceous earth, alumina, titanium oxide, magnesium oxide, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dowamite, and calcium sulfate. , Potassium titanate, barium sulfate, calcium sulfite, talc, clay, mica, asbestos, calcium silicate, montmorillonite, pentonite, graphite, aluminum powder, molybdenum sulfide and the like.

The cyclic olefin resin and other components can be mixed using a known method. For example, each component can be mixed simultaneously. The above-mentioned cyclic olefin-based resin is usually produced under an inert gas atmosphere, and in the present invention, the thus produced cyclic olefin-based resin is introduced into a pellet production apparatus such as a pelletizer under an inert gas atmosphere. To produce pellets.

The occurrence of black spot defects in the production of a molded article using a cyclic olefin resin pellet is promoted by oxygen dissolved in the cyclic olefin resin. The dissolved oxygen is often mixed when the cyclic olefin resin is produced and then pelletized in the air. Therefore, in the present invention, the step of producing pellets from the molten cyclic olefin resin is performed in an inert gas atmosphere to produce cyclic olefin resin pellets.

In the present invention, the inert gas may be any gas as long as it is inert to the cyclic olefin resin. For example, chlorine, silane, carbon monoxide and the like have reactivity and are difficult to handle. However, it is not suitable as an atmosphere gas for producing pellets.

For the above reasons, in the present invention, for example, helium, neon, nitrogen, argon, xenon, krypton, carbon dioxide, etc. are used as the inert gas without causing the problems described above.

Further, the inert gas used in the present invention desirably has a boiling point of -100 ° C. or less. That is, when an inert gas having a boiling point exceeding -100 ° C. is used, the inert gas is dissolved in the cyclic olefin-based resin, and the dissolved gas is vaporized at the time of producing a molded article, whereby the cyclic gas is vaporized. Helium, neon, nitrogen, argon, and xenon are particularly preferred because the olefin resin may foam and the molded article may have silvers and leaks or bubbles.

When producing the cyclic olefin resin pellets of the present invention, the above-mentioned inert gas is used, and it is desirable that such an inert gas does not contain oxygen. When contained, the permissible amount of mixed oxygen is usually 0.1 atm or less, preferably 0.07 atm or less, more preferably 0.05 atm or less, when expressed as oxygen partial pressure.

In the present invention, if the cyclic olefin resin pellets have a predetermined size, black spot defects are less likely to occur. That is, if the dissolved oxygen amount is the same, the smaller the cyclic olefin-based resin pellet, the larger the ratio of the surface area per volume, and the more easily the gas dissolved in the pellet can be diffused. Therefore, by reducing the size of the pellet, it is possible to suppress the occurrence of burning when the pellet is melted. Therefore, in the present invention, the size of the cyclic olefin-based resin pellet is 0.1 g / 1.
It is preferable to adjust within the range of 00 to 5 g / 100,
Further, it is particularly preferable that the amount be in the range of 0.5 g / 100 to 4.5 g / 100. If the cyclic olefin-based resin pellets of the present invention are smaller than the above values, the pellets may become dust and adhere to various places, resulting in reduced workability.

According to the present invention, the cyclic olefin-based resin pellets produced under the above conditions are mixed with an oxygen partial pressure of 0.1 atm.
Hereafter, it is stored in an inert gas atmosphere of preferably 0.07 atm or less, more preferably 0.05 atm or less. For example, the cyclic olefin-based resin pellet obtained as described above is placed in an airtight container such as an airtight bag on which aluminum is deposited, and the air in the airtight container is replaced with an inert gas and sealed and stored. .

The inert gas used here includes:
Helium, nitrogen, neon, argon, xenon, krypton, carbon dioxide and the like used in the above pelletizing can be exemplified. Note that the inert gas used for pelletizing and the inert gas used for storage need not be the same, and may be different. However, it is preferred to use the same inert gas for pelletization and pellet storage. Thus, it is economical to use the same inert gas. As described above, it is desirable that the inert gas used here does not contain oxygen, but the oxygen partial pressure is usually 0.1 atm or less,
Preferably 0.07 atm or less, more preferably 0.05a
It is possible to use an inert gas of tm or less. Further, in the present invention, after producing the cyclic olefin-based resin pellets in an inert gas atmosphere, it is preferable to store the pellets in an inert gas without contacting the pellets with the air. After production, even if it is brought into contact with air for a short time, since the oxygen partial pressure in the pellet does not rise rapidly, it may be stored in an inert gas after being left in air for a short time. . In this case, the cyclic olefin-based resin pellets that have been left in the air for a short period of time can be stored in an inert gas as it is,
Before storing in an inert gas atmosphere, degassing is performed under reduced pressure under heating, and after processing this cyclic olefin resin pellet to release oxygen contained in the pellet as much as possible,
Preferably, the treated pellets are stored in an inert gas atmosphere. In this case, the heating temperature is 70
It is preferable that the treatment is performed under the conditions of up to 180 ° C., a degree of reduced pressure of 200 torr or less, and a treatment time of 4 hours or more.

The thus-stored cyclic olefin resin pellets of the present invention are not oxidized by dissolved oxygen when they are put into a melting device and melted, and black spots are extremely unlikely to occur. Accordingly, the cleaning cycle of the melting device can be lengthened, so that a molded body can be manufactured efficiently. In addition, the occurrence of black spot defects in the obtained molded body is significantly reduced.

The molding conditions for producing a molded article using the cyclic olefin-based resin pellets of the present invention can be appropriately set. However, the molded article is produced in a shorter cycle by setting the heating temperature higher than in the past. It becomes possible.

The cyclic olefin-based resin pellets of the present invention are used by a method of melting the cyclic olefin-based resin pellets and molding them into a desired shape, such as injection molding, injection compression molding, extrusion molding, extrusion hollow molding, and inflation molding. be able to.

The cyclic olefin-based resin pellets of the present invention are excellent in transparency, so that they can be used for lenses, prisms,
It is suitable as a raw material for producing a molded article used for optical applications such as a light guide plate, a reflection plate, a disk, and an optical recording medium.

Further, specific examples of the molded article using the cyclic olefin resin pellet of the present invention include an eyeglass lens, a Fresnel lens, a condenser lens, a finder lens in a camera, a photographing lens, a contact lens, and a projection lens. , VTR zoom lens, CD objective lens, image sensor lens, copier plate lens, LCD light guide plate, diffuser plate, reflector plate, indicator prism for automobiles, CD, DVD, DRAW, WORM, magneto-optical Recording disks, optical cards and the like can be mentioned.

The cyclic olefin resin pellets of the present invention are also suitable as a raw material for producing molded articles used in the medical field. Examples of such molded articles in the medical field include vials, prefilled syringes, and analytical instruments. A cell, a vial tube, etc. can be mentioned.

In other fields, various transparent panels such as an iron, a water tank of a coffee maker, and a stereo front panel can be mentioned.

[0100]

According to the present invention, the cyclic olefin resin pellets are produced in an inert gas atmosphere, and the oxygen partial pressure in the pellets produced in the inert gas atmosphere is not increased. Specifically, pellets stored in an inert atmosphere. Therefore,
Because the oxygen partial pressure in the cyclic olefin-based resin pellets of the present invention is low, the influence of oxygen is reduced when the cyclic olefin-based resin pellets are melted, and so-called black spot defects due to burning in a melting device are reduced. Less likely to occur. Moreover, since the burning is less likely to occur, the cleaning cycle of the melting device can be lengthened, so that a molded article made of a cyclic olefin-based resin can be efficiently produced.

[0101]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

[0102]

EXAMPLE 1 Ethylene and tetracyclo [4.4.0.1 ^{2, 5} .1
^7,10 ] -3-dodecene (hereinafter simply referred to as “tetracyclododecene”
Cyclic olefin-based random copolymer (intrinsic viscosity [η] measured in decalin at 135 ° C .: 0.48 dl / g, softening temperature (TM
A): A resin of 140 ° C., MFR: 40 g / 10 min] is pelletized with a pelletizer in N ₂ so as to have a pellet size of 4.5 g / 100 to obtain a cyclic olefin-based resin pellet. produced, and stored the pellets (hereinafter O ₂ partial pressure 0.05 atm) N ₂ 2 months, in airtight bag formed of an aluminum foil in.

Using the cyclic olefin-based resin pellets stored as described above, under the molding conditions described below,
200 shot molding was performed, the molding machine was disassembled, the screw was visually observed, and the state of occurrence of burning was evaluated on a five-point scale as described below.

[0104]Molding condition Molding machine; Toshiba Corporation, IS-50 Cylinder temperature: 320 ° C Back pressure: 0 kg / cm^Two Screw rotation speed; 250rpm  Weighing: 21.5mm Cooling time: 7 seconds Filling time: 0.5 seconds Molding cycle: 20 secondsEvaluation of burning condition AA: There is almost no burning in the area where the resin is plasticized.

BB: Burning occurred at a half pitch. CC: Burning occurred at one pitch. DD: Burning occurred at two pitches.

EE: Burning occurred at three pitches. Table 1 shows the results.

[0107]

Comparative Example 1 The cyclic olefin-based resin pellets produced in Example 1 under a nitrogen atmosphere were stored in air for two months.

Using the cyclic olefin-based resin pellets left in the air for 2 months as described above, 1200 shot molding was performed in the same manner as in Example 1, and the occurrence of burning was evaluated in the same manner.

Table 1 shows the results.

[0110]

Example 2 In Example 1, the cyclic olefin-based resin pellets produced under a nitrogen atmosphere were once left in the air for 2 years, then degassed at 120 ° C. and 1 Torr for 120 hours. To N ₂ (O ₂ partial pressure 0.05 atm
2) for 2 months in an airtight bag made of aluminum foil.

Using the cyclic olefin-based resin pellets stored as described above, 120
0 shot molding was performed, and the occurrence of burning was evaluated in the same manner.

Table 1 shows the results.

[0113]

Comparative Example 2 In Example 1, the cyclic olefin resin pellets produced under a nitrogen atmosphere were once left in the air for 2 years, then degassed at 120 ° C. and 1 Torr for 120 hours, and then degassed in the air. For 2 months.

Using the cyclic olefin-based resin pellets stored as described above, 120
0 shot molding was performed, and the occurrence of burning was evaluated in the same manner.

The results are shown in Table 1.

[0116]

Comparative Example 3 In Example 1, after the cyclic olefin-based resin pellets produced in a nitrogen atmosphere were left in the air for 2 years, 1200 shot molding was performed in the same manner as in Example 1 without degassing. The burn condition was evaluated in the same manner.

Table 1 shows the results.

[0118]

Example 3 Cyclic olefin random copolymer formed from ethylene and tetracyclododecene [Intrinsic viscosity [η] measured in decalin at 135 ° C .: 0.48 dl /
g, softening temperature (TMA): 140 ° C, MFR: 40 g / 10
min] resin in N ₂ , pellet size 3.4 g / 100
The pellet was pelletized using a pelletizer so as to obtain the weight of the individual pellets to produce a cyclic olefin-based resin pellet. This cyclic olefin-based resin pellet was stored in air for two months.

Using the cyclic olefin-based resin pellets stored as described above, 120
0 shot molding was performed, and the occurrence of burning was evaluated in the same manner.

Table 1 shows the results. The size of the cyclic olefin resin pellets stored in Example 3 was 3.4 g / 100.
And smaller than the pellets (4.5 g / 100) used in Example 1 and Comparative Example 1.

When producing a molded product, the 3.4 g / 100 pellets were used in an amount of 4.5 g used in Example 1 and Comparative Example 1.
Melts more easily than / 100 pellets. Therefore, burning is slightly more likely to occur than the pellets of Example 1 stored in nitrogen for 2 months. However, the pellets of Comparative Example 1 in which 4.5 g / 100 pellets were stored in air for 2 months were used. Less occurrence of burning than when used.

[0122]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08G 61/08 C08G 61/08 // (C08F 232/00 210: 02) (C08F 210/02 232: 00)

Claims (2)

[Claims] 1. A pellet comprising a cyclic olefin resin selected from the group consisting of the following [I-1], [I-2], [I-3] and [I-4], wherein the pellet is an Pellets produced in an active gas atmosphere and stored in an inert gas atmosphere having an oxygen partial pressure of 0.1 atm or less; [I-1] Ethylene and represented by the following formula [I] or [II] Ethylene obtained by copolymerizing cyclic olefin
Cyclic olefin random copolymer, [I-2] ring-opened polymer or copolymer of cyclic olefin represented by the following formula [I] or [II], [I-3] ring-opening of [I-2] above A hydride of a polymer or a copolymer, and [I-4] a graft-modified product of the above [I-1], [I-2] or [I-3]; (In the formula [I], n is 0 or 1, m is 0 or a positive integer, 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 ^{15 to} R ¹⁸ may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring has a double bond; R ¹⁵ and R ¹⁶ or R ¹⁷ and R ¹⁸ may form an alkylidene group.), (In the formula [II], p and q are 0 or an integer of 1 or more, m and n are 0, 1 or 2, and R ^{1 to} R ¹⁹ are each independently a hydrogen atom, a halogen atom, an aliphatic carbon atom, A hydrogen group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group or an alkoxy group, wherein a carbon atom to which R ⁹ (or R ¹⁰ ) is bonded and a carbon atom to which R ¹³ or R ¹¹ is bonded; May be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when n = m = 0, R ¹⁵ and R ¹² or R ¹⁵ and R ¹⁹ are bonded to each other to form a monocyclic or It may form a polycyclic aromatic ring.). 2. The cyclic olefin resin pellet 10
2. The cyclic olefin-based resin pellet according to claim 1, wherein the weight of zero is in the range of 0.1 to 5.0 g.