JPH05262899A - Stretched film - Google Patents

Abstract

PURPOSE:To provide a stretched film excellent in transparency, shrinkability at low temps. and elastic recovery, and improved in tensile strength at break and elastic recovery. CONSTITUTION:A raw film comprising a cyclic olefin copolymer of at most 30 deg.C in glass transition temp. (Tg) which has recurring units originating in an alpha:4-olefin and recurring units originating in a cyclic olefin is formed into a monoaxially or biaxially stretched film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretched film which is excellent in transparency, low temperature shrinkability and elastic recovery property and can be suitably used as a food packaging material, a transportation packaging material and the like.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As the polyolefin-based shrink film, uniaxially or biaxially stretched polyethylene, polypropylene or the like is widely used. In this case, in shrink wrapping, the shrinkage of the film is normally completed by fusing and sealing the film and then passing through a shrink tunnel by infrared heating or the like. Therefore, the shrink film is required to have low-temperature shrinkability so that the contents will not be adversely affected by heating when passing through the shrink tunnel.

On the other hand, JP-A-2-196832 and 2
JP-A-180976 discloses a biaxially stretched sheet and film made of a copolymer of ethylene and a cyclic olefin. However, the copolymers disclosed in these publications have a glass transition temperature of 50 to 230 ° C. and cannot be said to have excellent low temperature shrinkability. This is also clear from the fact that the heat shrinkage rate at 80 ° C. is 0%. Further, the inventors of the present invention have proposed a thin-walled molded product made of a copolymer obtained by copolymerizing an α-olefin and a cyclic olefin at a specific ratio (Japanese Patent Application No. 3-99839).
However, the molded product shown here is a non-stretched product, and the tensile breaking strength and elastic recovery rate are not always sufficient depending on the application.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stretched film which is excellent in transparency, low-temperature shrinkability, and elastic recovery, and has improved tensile breaking strength and elastic recovery. ..

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that when a cyclic olefin copolymer having a specific structure having a specific glass transition temperature (Tg) is used as a material for a stretched film. The inventors have found that the above objects can be effectively achieved, and completed the present invention.

That is, the present invention is a raw material comprising a cyclic olefin-based copolymer having a repeating unit derived from an α-olefin and a repeating unit derived from a cyclic olefin and having a glass transition temperature (Tg) of 30 ° C. or lower. Provided is a stretched film which is obtained by uniaxially or biaxially stretching a fabric.

The present invention will be described in more detail below.
The stretched film of the present invention comprises a cyclic olefin-based copolymer having an α-olefin unit and a cyclic olefin unit. Here, the above α-olefin is not necessarily limited, but for example, the following general formula [X]

[Chemical 1] (In the formula [X], R ^a represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms).

In the repeating unit represented by the above general formula [X], R ^a represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Here, as the hydrocarbon group having 1 to 20 carbon atoms, specifically, for example, methyl group, ethyl group, isopropyl group, n-propyl group, isobutyl group, n-butyl group, n-hexyl group, n-octyl group. Group, n-octadecyl group and the like. In addition, the general formula [X]
Specific examples of the α-olefin giving the repeating unit represented by are, for example, ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, Examples thereof include 1-decene and 1-eicosene.

Further, the cyclic olefin is not necessarily limited, but for example, the following general formula [Y]

[Chemical 2] (In the formula [Y], R ^{b to} R ^m are each a hydrogen atom or a carbon number 1
~ 20 represents a hydrocarbon group or a substituent containing a halogen atom, an oxygen atom or a nitrogen atom, and n represents an integer of 0 or more. R ^j or R ^k and R ¹ or R ^m may form a ring with each other. R ^{b to} R ^m may be the same or different from each other. ) And those which give a repeating unit.

In the repeating unit represented by the above general formula [Y], R ^{b to} R ^m are each a hydrogen atom or a carbon number 1
To 20 hydrocarbon groups or substituents containing a halogen atom, an oxygen atom or a nitrogen atom. Here, as the hydrocarbon group having 1 to 20 carbon atoms, specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n
-Butyl group, isobutyl group, t-butyl group, hexyl group and other alkyl groups having 1 to 20 carbon atoms, phenyl group, tolyl group, aryl group having 6 to 20 carbon atoms such as benzyl group, alkylaryl group or arylalkyl Group, methylidene group, ethylidene group, propylidene group, etc., having 1 to 2 carbon atoms
0 alkylidene group, vinyl group, allyl group, etc. with 2 carbon atoms
To 20 alkenyl groups and the like. However,
R ^b , R ^c , R ^f and R ^g exclude alkylidene groups. In addition, R
^{When any of d} , R ^e and R ^{h to} R ^m is an alkylidene group,
The carbon atom to which it is attached has no other substituents.

Specific examples of the substituent containing a halogen atom include halogen groups such as fluorine, chlorine, bromine and iodine, and halogen substitution having 1 to 20 carbon atoms such as chloromethyl group, bromomethyl group and chloroethyl group. An alkyl group etc. can be mentioned. Specific examples of the substituent containing an oxygen atom include an alkoxy group having 1 to 20 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a phenoxy group, and a carbon number 1 to 20 such as a methoxycarbonyl group and an ethoxycarbonyl group. Alkoxycarbonyl group and the like can be mentioned. Specifically as a substituent containing a nitrogen atom,
For example, a C1-C20 alkylamino group, such as a dimethylamino group and a diethylamino group, a cyano group, etc. can be mentioned.

Specific examples of the cyclic olefin providing the repeating unit represented by the general formula [Y] include, for example, norbornene, 5-methylnorbornene, 5-ethylnorbornene, 5-propylnorbornene, 5,6-dimethylnorbornene, 1 -Methylnorbornene, 7-methylnorbornene, 5,5,6-trimethylnorbornene, 5-
Phenylnorbornene, 5-benzylnorbornene, 5
-Ethylidene norbornene, 5-vinyl norbornene,
1,4,5,8-dimethano-1,2,3,4,4a,
5,8,8a-octahydronaphthalene, 2-methyl-
1,4,5,8-dimethano-1,2,3,4,4a,
5,8,8a-octahydronaphthalene, 2-ethyl-
1,4,5,8-dimethano-1,2,3,4,4a,
5,8,8a-octahydronaphthalene, 2,3-dimethyl-1,4,5,8-dimethano-1,2,3,4,4
a, 5,8,8a-octahydronaphthalene, 2-hexyl-1,4,5,8-dimethano-1,2,3,4,4
a, 5,8,8a-octahydronaphthalene, 2-ethylidene-1,4,5,8-dimethano-1,2,3,4
4a, 5,8,8a-octahydronaphthalene, 2-fluoro-1,4,5,8-dimethano-1,2,3,4
4a, 5,8,8a-octahydronaphthalene, 1,5
-Dimethyl-1,4,5,8-dimethano-1,2,3
4,4a, 5,8,8a-octahydronaphthalene, 2
-Cyclohexyl-1,4,5,8-dimethano-1,
2,3,4,4a, 5,8,8a-octahydronaphthalene, 2,3-dichloro-1,4,5,8-dimethano-
1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-isobutyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a- Octahydronaphthalene, 1,2-dihydrodicyclopentadiene,
5-chloronorbornene, 5,5-dichloronorbornene, 5-fluoronorbornene, 5,5,6-trifluoro-6-trifluoromethylnorbornene, 5-chloromethylnorbornene, 5-methoxynorbornene,
Examples thereof include 5,6-dicarboxyl norbornene anhydrate, 5-dimethylamino norbornene, and 5-cyanonorbornene. Among these, norbornene or its derivative is particularly preferable.

The cyclic olefin copolymer used in the present invention is basically a copolymer of the above-mentioned α-olefin and a cyclic olefin, but it is within the range not impairing the object of the present invention. So, in addition to these two essential components,
If necessary, other copolymerizable unsaturated monomer components may be used. As such an unsaturated monomer which may be optionally copolymerized, specifically, among the above α-olefin components, those not previously used, among the above cyclic olefin components, Examples thereof include those not used, cyclic dienes such as dicyclopentadiene and norbornadiene, chain dienes such as butadiene, isoprene and 1,5-hexadiene, and monocyclic olefins such as cyclopentene and cycloheptene.

The cyclic olefin-based copolymer used in the present invention has an α-olefin unit content [x] and a cyclic olefin unit content [y] of [x] of 80 to 99.5 mol%. It is preferable that [y] is 20 to 0.5 mol%, particularly [x] is 85 to 99 mol%, and [y] is 15 to 1 mol%. If the content [x] of the α-olefin unit is less than 80 mol%, the glass transition temperature (Tg) and the tensile elastic modulus of the copolymer are increased, and the elastic recovery property and impact resistance of the obtained stretched film, The elasticity may become insufficient. On the other hand, the content rate of the cyclic olefin unit [y]
Is less than 0.5 mol%, the crystallinity of the copolymer becomes high, and the effect of introducing a cyclic olefin component such as elastic recovery may become insufficient.

The cyclic olefin copolymer used in the present invention is a substantially linear copolymer in which α-olefin units and cyclic olefin units are linearly arranged, and does not have a gel-like crosslinked structure. It is preferably one. It can be confirmed that the copolymer does not have a gel-like crosslinked structure by completely dissolving the copolymer in decalin at 135 ° C. However, when it is used as a stretched film, a film containing a copolymer partially crosslinked by heat, organic peroxide, ionizing radiation or the like can be used.

The cyclic olefin copolymer (soluble) used in the present invention preferably has an intrinsic viscosity [η] measured in decalin at 135 ° C. of 0.01 to 20 dl / g. If the intrinsic viscosity [η] is less than 0.01 dl / g, the strength may be significantly reduced, and if it exceeds 20 dl / g, the moldability may be significantly deteriorated. A more preferable intrinsic viscosity [η] is 0.05 to 10 dl / g.

The molecular weight of the cyclic olefin copolymer used in the present invention is not particularly limited, but for soluble copolymers, it was measured by gel permeation chromatography (GPC) [polyethylene conversion]. Weight average molecular weight Mw of 1,000 to 2,000,000
0, particularly 5,000 to 1,000,000, number average molecular weight Mn of 500 to 1,000,000, especially 2,000
It is preferable that the molecular weight distribution (Mw / Mn) is 1.3 to 4, particularly 1.4 to 3. When the molecular weight distribution (Mw / Mn) is greater than 4, the content of low molecular weight substances increases, which may cause stickiness of the stretched film.

The cyclic olefin copolymer used in the present invention is required to have a glass transition temperature (Tg) of less than 30 ° C. By using such a copolymer, a stretched film having excellent low temperature shrinkability can be obtained. More preferred glass transition temperature (Tg) is -30 to 20 ° C, especially -3.
It is 0 to 15 ° C. In this case, the glass transition temperature (Tg) of the cyclic olefin-based copolymer used in the present invention can be arbitrarily controlled by changing the type and composition of the monomer, and the intended use and use can be achieved. The glass transition temperature (Tg) can be arbitrarily changed according to the temperature and the like.

The cyclic olefin copolymer used in the present invention has a crystallinity of 0 to 4 as measured by X-ray diffractometry.
It is preferably 0%. When the crystallinity exceeds 40%, elastic recovery and transparency may be deteriorated. More preferable crystallinity is 0 to 30%, especially 0 to 25%.

The cyclic olefin copolymer used in the present invention preferably has a tensile elastic modulus of less than 3,000 Kg / cm ² . When the tensile elastic modulus is 3,000 Kg / cm ² or more, for example, when a stretched film is used as a packaging film, a large amount of energy is required at the time of packaging, and it is difficult to form a beautiful package conforming to the shape of the packaged article. May be. Further, the impact resistance of the stretched film may be insufficient. More preferable tensile elastic modulus is 50 to
It is 2,000 Kg / cm ² .

The cyclic olefin copolymer used in the present invention preferably has an elastic recovery rate of 20% or more. When the elastic recovery rate is less than 20%, for example, when an article is wrapped with a stretched film, sagging may occur or the holding force may be reduced. A more preferable elastic recovery rate is 3
It is 0% or more, particularly 40% or more. The elastic recovery rate was measured using an autograph at a pulling speed of 62 mm / min, a width of 6 mm, and a distance between the clamps of 50 mm (L ₀ ).
% Stretch and pull, hold for 5 minutes, then
It is a value obtained by the following formula, in which the length (L ₁ ) of the sheet between the clamps was measured after 1 minute of sudden contraction without rebounding. Elastic recovery rate (%) = [1-{(L ₁ −L ₀ ) / L ₀ }] ×
100

The cyclic olefin copolymer used in the present invention preferably has a broad melting peak by DSC (temperature rise measurement) of less than 90 ° C. DSC (temperature rise measurement)
The copolymer having a sharp melting peak at 90 ° C. or higher due to the above has a wide composition distribution of the copolymer of cyclic olefin and α-olefin, and the elastic recovery of the stretched film may be insufficient. The broad melting peak by DSC (temperature rise measurement) is more preferably in the range of 10 to 85 ° C. In DSC (temperature rise measurement), the melting point (melting peak) of the cyclic olefin-based copolymer is not sharply seen, and particularly in the case of low crystallinity, it is almost a peak at the normal polyethylene measurement condition level. Does not come out. Further, the cyclic olefin-based copolymer used in the present invention preferably has one or more relatively small sub-peaks on the high temperature side of the main peak in the crystallization peak by DSC (temperature drop measurement). Due to the characteristics of the above-mentioned thermal properties, the physical properties of the stretched film can be obtained, and the molding temperature range is widened.
A stretched film can be stably obtained.

The cyclic olefin-based copolymer used in the present invention may be a copolymer having only the physical properties in the above range, and may partially include the copolymer having the physical properties outside the above range. It may be one that has been. In the latter case, all physical property values may be included in the above range.

The method for producing the cyclic olefin-based copolymer used in the present invention is not limited, but a catalyst containing the following compounds (A) and (B) as main components or the following compound (A),
It can be efficiently produced by copolymerizing the α-olefin and the cyclic olefin using a catalyst containing (B) and (C) as a main component. (A) Transition metal compound (B) Compound which reacts with transition metal compound to form an ionic complex (C) Organoaluminum compound

In this case, as the transition metal compound (A), there are IVB group, VB group, VIB group, VIIB group and VI of the periodic table.
Transition metal compounds containing transition metals belonging to Group II can be used. Specifically, titanium, zirconium, hafnium, chromium, manganese, nickel, palladium, platinum and the like are preferable as the above transition metal, and among them, zirconium, hafnium, titanium, nickel and palladium are preferable.

Examples of such a transition metal compound (A) include various compounds, but in particular, a compound containing a transition metal of IVB group or VIII group, especially a transition metal selected from IVB group of the periodic table, that is, A compound containing titanium (Ti), zirconium (Zr) or hafnium (Hf) can be preferably used, and particularly, a compound represented by the following general formula (I),
A cyclopentadienyl compound represented by (II) or (III) or a derivative thereof, or a compound represented by the following general formula (IV) or a derivative thereof is preferable. ^{_{CpM 1 R 1 a R 2 b}} R 3 c ... (I) Cp 2 M 1 R 1 a R 2 b ... (II) (Cp-A e -Cp) M 1 R 1 a R 2 b ... (III) M ¹ R ¹ _a R ² _b R ³ _c R ⁴ _d (IV)

[In the formulas (I) to (IV), M ¹ is Ti, Zr.
Or Hf atom, Cp is a cyclopentadienyl group,
A cyclic unsaturated hydrocarbon group or a chain unsaturated hydrocarbon group such as a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a tetrahydroindenyl group, a substituted tetrahydroindenyl group, a fluorenyl group or a substituted fluorenyl group is shown. R ¹ , R ² , R ³ and R ⁴ are each σ
A binding ligand, a chelating ligand, a Lewis base, or another ligand is shown. Specific examples of the σ binding ligand include a hydrogen atom, an oxygen atom, a halogen atom, and a carbon number of 1 to 1. 20 alkyl groups, 1-20 carbon alkoxy groups, 6 carbon atoms
Examples include 20 aryl groups, alkylaryl groups or arylalkyl groups, acyloxy groups having 1 to 20 carbon atoms, allyl groups, substituted allyl groups, and substituents containing a silicon atom, and examples of chelating ligands include Examples thereof include an acetylacetonate group and a substituted acetylacetonate group. A indicates crosslinking by covalent bond. a, b, c and d
Are integers of 0 to 4, respectively, and e is an integer of 0 to 6. R
Two or more of ¹ , R ² , R ³ and R ⁴ may combine with each other to form a ring. When Cp has a substituent, the substituent is preferably an alkyl group having 1 to 20 carbon atoms. In the formulas (II) and (III), the two Cp's may be the same or different from each other. ]

Examples of the substituted cyclopentadienyl group in the above formulas (I) to (III) include methylcyclopentadienyl group, ethylcyclopentadienyl group, isopropylcyclopentadienyl group, 1,2-dimethyl. Cyclopentadienyl group, tetramethylcyclopentadienyl group, 1,3-dimethylcyclopentadienyl group, 1,
2,3-trimethylcyclopentadienyl group, 1,2,
4-trimethylcyclopentadienyl group, pentamethylcyclopentadienyl group, trimethylsilylcyclopentadienyl group and the like can be mentioned. In addition, (I) ~ (I
Specific examples of R ^{1 to} R ^{4 in} the formula V) include, for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom as a halogen atom; a methyl group, an ethyl group and n-propyl as an alkyl group having 1 to 20 carbon atoms. Group, iso-propyl group,
n-butyl group, octyl group, 2-ethylhexyl group; methoxy group, ethoxy group, propoxy group, butoxy group, phenoxy group as alkoxy group having 1 to 20 carbon atoms; aryl group having 6 to 20 carbon atoms, alkylaryl group or Phenyl group, tolyl group, xylyl group, benzyl group as an arylalkyl group; heptadecylcarbonyloxy group as an acyloxy group having 1 to 20 carbon atoms; trimethylsilyl group as a substituent containing a silicon atom, (trimethylsilyl) methyl group: Lewis base As dimethyl ether,
Ethers such as diethyl ether and tetrahydrofuran, thioethers such as tetrahydrothiophene, esters such as ethylbenzoate, nitriles such as acetonitrile and benzonitrile, trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, pyridine, 2, Amines such as 2'-bipyridine and phenanthroline; phosphines such as triethylphosphine and triphenylphosphine; ethylene, butadiene, 1-pentene, isoprene, pentadiene, 1-hexene and their derivatives as chain unsaturated hydrocarbons;
Examples of the cyclic unsaturated hydrocarbon include benzene, toluene, xylene, cycloheptatriene, cyclooctadiene, cyclooctatriene, cyclooctatetraene and derivatives thereof. Examples of the cross-linking by the covalent bond of A in the formula (III) include methylene cross-link, dimethyl methylene cross-link, ethylene cross-link, 1,1′-
Examples thereof include cyclohexylene crosslinks, dimethylsilylene crosslinks, dimethylgermylene crosslinks, and dimethylstannylene crosslinks.

Examples of such compounds include the following compounds and compounds obtained by substituting zirconium of these compounds with titanium or hafnium. Compound of formula (I) (pentamethylcyclopentadienyl) trimethylzirconium, (pentamethylcyclopentadienyl) triphenylzirconium, (pentamethylcyclopentadienyl) tribenzylzirconium, (pentamethylcyclopentadienyl) trichloro Zirconium, (pentamethylcyclopentadienyl) trimethoxyzirconium, (cyclopentadienyl) trimethylzirconium, (cyclopentadienyl) triphenylzirconium, (cyclopentadienyl) tribenzylzirconium, (cyclopentadienyl) trichloro Zirconium, (cyclopentadienyl) trimethoxyzirconium, (cyclopentadienyl) dimethyl (methoxy) zirconium, (methylcyclopentadienyl) trimethyldi Ruconium, (methylcyclopentadienyl) triphenylzirconium, (methylcyclopentadienyl) tribenzylzirconium, (methylcyclopentadienyl) trichlorozirconium, (methylcyclopentadienyl) dimethyl (methoxy) zirconium,
(Dimethylcyclopentadienyl) trichlorozirconium, (trimethylcyclopentadienyl) trichlorozirconium, (trimethylsilylcyclopentadienyl) trimethylzirconium, (tetramethylcyclopentadienyl) trichlorozirconium,

A compound of formula (II) bis (cyclopentadienyl) dimethyl zirconium,
Bis (cyclopentadienyl) diphenylzirconium, bis (cyclopentadienyl) diethylzirconium, bis (cyclopentadienyl) dibenzylzirconium, bis (cyclopentadienyl) dimethoxyzirconium, bis (cyclopentadienyl) dichlorozirconium , Bis (cyclopentadienyl) dihydride zirconium, bis (cyclopentadienyl) monochloromonohydride zirconium, bis (methylcyclopentadienyl) dimethylzirconium, bis (methylcyclopentadienyl) dichlorozirconium, bis (methylcyclo Pentadienyl) dibenzylzirconium, bis (pentamethylcyclopentadienyl) dimethylzirconium, bis (pentamethylcyclopentadienyl) dichlorozirconium, Scan (pentamethylcyclopentadienyl) dibenzyl zirconium, bis (pentamethylcyclopentadienyl) chloromethyl zirconium,
Bis (pentamethylcyclopentadienyl) hydridomethylzirconium, (cyclopentadienyl) (pentamethylcyclopentadienyl) dichlorozirconium,

Compound of formula (III) ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) dichlorozirconium, ethylenebis (tetrahydroindenyl) dimethylzirconium, ethylenebis (tetrahydroindenyl) dichlorozirconium, dimethylsilylenebis (cyclo) Pentadienyl) dimethyl zirconium, dimethylsilylene bis (cyclopentadienyl) dichlorozirconium, isopropylidene (cyclopentadienyl) (9-fluorenyl) dimethylzirconium, isopropylidene (cyclopentadienyl) (9-fluorenyl) dichlorozirconium , [Phenyl (methyl) methylene] (9-fluorenyl) (cyclopentadienyl) dimethylzirconium, diphenylmethylene (cyclopen Tadienyl)
(9-fluorenyl) dimethylzirconium, ethylene (9-fluorenyl) (cyclopentadienyl) dimethylzirconium, cyclohexylidene (9-fluorenyl) (cyclopentadienyl) dimethylzirconium,
Cyclopentylidene (9-fluorenyl) (cyclopentadienyl) dimethylzirconium, cyclobutylidene (9-fluorenyl) (cyclopentadienyl) dimethylzirconium, dimethylsilylene (9-fluorenyl) (cyclopentadienyl) dimethylzirconium,
Dimethylsilylenebis (2,3,5-trimethylcyclopentadienyl) dichlorozirconium, dimethylsilylenebis (2,3,5-trimethylcyclopentadienyl) dimethylzirconium, dimethylsilylenebis (indenyl) dichlorozirconium

Examples of the compounds other than the cyclopentadienyl compounds represented by the above general formulas (I), (II) and (III) include the compounds of the above formula (IV). Examples thereof include a zirconium compound, a hafnium compound, and a titanium compound having one or more of an alkyl group, an alkoxy group, and a halogen atom, such as a compound in which zirconium is replaced with hafnium or titanium. Tetramethylzirconium, tetrabenzylzirconium, tetramethoxyzirconium, tetraethoxyzirconium, tetrabutoxyzirconium, tetrachlorozirconium, tetrabromozirconium,
Butoxytrichlorozirconium, dibutoxydichlorozirconium, bis (2,5-di-t-butylphenoxy) dimethylzirconium, bis (2,5-di-t-butylphenoxy) dichlorozirconium, zirconium bis (acetylacetonate),

The transition metal compound containing a VB to VIII group transition metal is not particularly limited, and specific examples of the chromium compound include tetramethylchromium and tetra (t).
-Butoxy) chromium, bis (cyclopentadienyl) chromium, hydridotricarbonyl (cyclopentadienyl) chromium, hexacarbonyl (cyclopentadienyl) chromium, bis (benzene) chromium, tricarbonyl tris (triphenylphosphonate) Examples thereof include chromium, tris (allyl) chromium, triphenyltris (tetrahydrofuran) chromium, chromium tris (acetylacetonate) and the like.

Specific examples of manganese compounds include tricarbonyl (cyclopentadienyl) manganese, pentacarbonylmethylmanganese, bis (cyclopentadienyl) manganese, manganese bis (acetylacetonate) and the like.

Specific examples of nickel compounds include, for example, dicarbonylbis (triphenylphosphine) nickel, dibromobis (triphenylphosphine) nickel, dinitrogen bis (bis (tricyclohexylphosphine) nickel), and chlorohydridobis (tricyclohexyl). Phosphine) nickel, chloro (phenyl) bis (triphenylphosphine) nickel, dimethylbis (trimethylphosphine) nickel, diethyl (2,
2'-bipyridyl) nickel, bis (allyl) nickel, bis (cyclopentadienyl) nickel, bis (methylcyclopentadienyl) nickel, bis (pentamethylcyclopentadienyl) nickel, allyl (cyclopentadienyl) Nickel, (cyclopentadienyl)
(Cyclooctadiene) nickel tetrafluoroborate, bis (cyclooctadiene) nickel, nickel bisacetylacetonate, allyl nickel chloride,
Tetrakis (triphenylphosphine) nickel, nickel chloride, (C ₆ H ₅ ) Ni {OC (C ₆ H ₅ ) CH = P (C ₆ H ₅ ) ₂ } {P (C
₆ H ₅ ) ₃ }, (C ₆ H ₅ ) Ni {OC (C ₆ H ₅ ) C (SO ₃ Na) = P (C ₆ H ₅ ) ₂ } {P (C
₆ H ₅ ) ₃ } and the like.

Specific examples of the palladium compound include dichlorobis (benzonitrile) palladium, carbonyltris (triphenylphosphine) palladium,
Dichlorobis (triethylphosphine) palladium, bis (t-butyl isocyanide) palladium, palladium bis (acetylacetonate), dichloro (tetraphenylcyclobutadiene) palladium, dichloro (1,5
-Cyclooctadiene) palladium, allyl (cyclopentadienyl) palladium, bis (allyl) palladium, allyl (1,5-cyclooctadiene) palladium tetrafluoroborate, (acetylacetonate)
Examples include (1,5-cyclooctadiene) palladium tetrafluoroborate, tetrakis (acetonitrile) palladium ditetrafluoroborate, and the like.

Any compound can be used as the compound (B) as long as it reacts with the transition metal compound (A) to form an ionic complex. A compound composed of a bound anion, particularly a coordination complex compound composed of a cation and an anion in which a plurality of groups are bonded to an element can be preferably used. The compound consisting of such a cation and an anion in which a plurality of groups are bound to an element is represented by the following formula (V) or (VI)
The compound represented by can be preferably used. ([L ¹ −R ⁷ ] ^{k +} ) _p ([M ³ Z ¹ Z ² … Z ⁿ ] ^(nm)- ) _q … (V) ([L ² ] ^{k +} ) _p ([M ⁴ Z ¹ Z ² …. Z ⁿ ] ^(nm)- ) _q (VI) (where L ² is M ⁵ , R ⁸ R ⁹ M ⁶ , R ¹⁰ ₃ C or R ¹¹ M ⁶ )

[In the formulas (V) and (VI), L ¹ is a Lewis base, M ³ and M ⁴ are VB group, VIB group and V of the periodic table, respectively.
IIB, VIII, IB, IIB, IIIA, IVA and
Elements selected from Group VA, preferably elements selected from Group IIIA, Group IVA and Group VA, M ⁵ and M ⁶ are Group IIIB, Group IVB, Group VB, Group VIB, Group VIB of the periodic table, respectively.
An element selected from Group III, Group IA, Group IB, Group IIA, Group IIB and Group VIIA, Z ^{1 to} Z ⁿ are each a hydrogen atom, a dialkylamino group, an alkoxy group having 1 to 20 carbon atoms, and 6 to 20 carbon atoms. Aryloxy group, C1-C20 alkyl group, C6-C20 aryl group, alkylaryl group, arylalkyl group, C1-C20 halogen-substituted hydrocarbon group, C1-C20 acyloxy Represents a group, an organic metalloid group or a halogen atom, and two or more of Z ^{1 to} Z ⁿ may be bonded to each other to form a ring. R ⁷
Is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and 6 to 6 carbon atoms
20 represents an aryl group, an alkylaryl group or an arylalkyl group, R ⁸ and R ⁹ are each a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a fluorenyl group, and R ¹⁰ is a C 1-20 group. An alkyl group, an aryl group, an alkylaryl group or an arylalkyl group is shown. R ¹¹ is tetraphenylporphyrin,
A macrocyclic ligand such as phthalocyanine is shown. m is M ³ , M
^{4 has} an valence of 1 to 7, n is an integer of 2 to 8, k is an ionic number of [L ¹ -R ⁷ ] and [L ² ] and is an integer of 1 to 7,
p is an integer of 1 or more, and q = (p × k) / (nm). ]

Specific examples of the Lewis base include ammonia, methylamine, aniline, dimethylamine, diethylamine, N-methylaniline, diphenylamine,
Amine such as trimethylamine, triethylamine, tri-n-butylamine, N, N-dimethylaniline, methyldiphenylamine, pyridine, p-promo-N, N-dimethylaniline, p-nitro-N, N-dimethylaniline, triethylphosphine Phosphines such as fin, triphenylphosphine and diphenylphosphine,
Examples thereof include ethers such as dimethyl ether, diethyl ether, tetrahydrofuran and dioxane, thioethers such as diethyl thioether and tetrahydrothiophene, and esters such as ethyl benzoate. Specific examples of M ³ and M ⁴ include B, Al, Si, P, As and Sb.
Etc., preferably B or P, and specific examples of M ⁵ are Li,
Specific examples of Na, Ag, Cu, Br, I, I _3, etc. and M ⁶ include Mn, Fe, Co, Ni, Zn and the like.

Specific examples of Z ^{1 to} Z ⁿ include, for example, a dimethylamino group and a diethylamino group as a dialkylamino group; a methoxy group, an ethoxy group, an n-butoxy group as an alkoxy group having 1 to 20 carbon atoms; and a carbon number of 6 A phenoxy group, a 2,6-dimethylphenoxy group, a naphthyloxy group as an aryloxy group having 20 to 20 carbon atoms, a methyl group, an ethyl group, an n-propyl group having 1 to 20 carbon atoms,
iso-propyl group, n-butyl group, n-octyl group,
2-ethylhexyl group; aryl group having 6 to 20 carbon atoms,
As an alkylaryl group or an arylalkyl group, a phenyl group, a p-tolyl group, a benzyl group, a 4-tert-butylphenyl group, a 2,6-dimethylphenyl group,
3,5-dimethylphenyl group, 2,4-dimethylphenyl group, 2,3-dimethylphenyl group; p-fluorophenyl group, 3,5-difluorophenyl group as a halogen-substituted hydrocarbon group having 1 to 20 carbon atoms, Pentachlorophenyl group, 3,4,5-trifluorophenyl group, pentafluorophenyl group, 3,5-di (trifluoromethyl) phenyl group; F, Cl, Br as halogen atoms
I: Examples of the organic metalloid group include pentamethylantimony group, trimethylsilyl group, trimethylgermyl group, diphenylarsine group, dicyclohexylantimony group and diphenylboron group. Specific examples of R ⁷ and R ¹⁰ include:
Examples are the same as those listed above. R ⁸ and R ⁹
Specific examples of the substituted cyclopentadienyl group include those substituted with an alkyl group such as a methylcyclopentadienyl group, a butylcyclopentadienyl group, and a pentamethylcyclopentadienyl group. Here, the alkyl group usually has 1 to 6 carbon atoms, and the number of substituted alkyl groups can be selected by an integer of 1 to 5. (V), (V
Among the compounds of formula I), those in which M ³ and M ⁴ are boron are preferred.

Among the compounds of the formulas (V) and (VI), the following can be used particularly preferably. Compound of formula (V) triethylammonium tetraphenylborate, tri (n-butyl) ammonium tetraphenylborate, trimethylammonium tetraphenylborate, tetraethylammonium tetraphenylborate, methyltri (n-butyl) ammonium tetraphenylborate, benzyltriphenylphenylborate (N-Butyl) ammonium, dimethyldiphenylammonium tetraphenylborate, methyltriphenylammonium tetraphenylborate, trimethylanilinium tetraphenylborate, methylpyridinium tetraphenylborate, benzylpyridinium tetraphenylborate, methyl tetraphenylborate (2-cyanopyridinium) ), Trimethylsulfonium tetraphenylborate, benzyldimethylsulfonium tetraphenylborate ,

Triethylammonium tetrakis (pentafluorophenyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, triphenylammonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl)
Tetrabutylammonium borate, tetrakis (pentafluorophenyl) borate (tetraethylammonium),
Tetrakis (pentafluorophenyl) borate (methyltri (n-butyl) ammonium), tetrakis (pentafluorophenyl) borate (benzyltri (n-butyl))
Ammonium), methyldiphenylammonium tetrakis (pentafluorophenyl) borate, methyltriphenylammonium tetrakis (pentafluorophenyl) borate, dimethyldiphenylammonium tetrakis (pentafluorophenyl) borate, anilinium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluoro) (Phenyl) methylanilinium borate,
Dimethylanilinium tetrakis (pentafluorophenyl) borate, trimethylanilinium tetrakis (pentafluorophenyl) borate, dimethyl (m-nitroanilinium) tetrakis (pentafluorophenyl) borate, dimethyl tetrakis (pentafluorophenyl) borate (p-bromo) Anilinium),

Pyridinium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) borate (p-cyanopyridinium), tetrakis (pentafluorophenyl) borate (N-methylpyridinium), tetrakis (pentafluorophenyl) borate (N
-Benzylpyridinium), tetrakis (pentafluorophenyl) borate (O-cyano-N-methylpyridinium), tetrakis (pentafluorophenyl) borate (p
-Cyano-N-methylpyridinium), tetrakis (pentafluorophenyl) borate (p-cyano-N-benzylpyridinium), tetrakis (pentafluorophenyl) borate trimethylsulfonium, tetrakis (pentafluorophenyl) borate benzyldimethylsulfonium, tetrakis ( Pentafluorophenyl) tetraphenylphosphonium borate, tetrakis (pentafluorophenyl) triphenylphosphonium borate, tetrakis (3,5-ditrifluoromethylphenyl) dimethylanilinium borate, triethylammonium hexafluoroarsenate,

Compound of Formula (VI) Ferrocenium tetraphenylborate, silver tetraphenylborate, trityl tetraphenylborate, tetraphenylborate (tetraphenylporphyrin-manganese), ferrocenium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) borate (1,1'-
Dimethylferrocenium), tetrakis (pentafluorophenyl) borate decamethylferrocenium, tetrakis (pentafluorophenyl) borate acetylferrocenium, tetrakis (pentafluorophenyl) borate formylferrocenium, tetrakis (pentafluorophenyl) borate Cyanoferrocenium, silver tetrakis (pentafluorophenyl) borate, trityl tetrakis (pentafluorophenyl) borate, lithium tetrakis (pentafluorophenyl) borate, sodium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) borate (tetra Phenylporphyrin manganese), tetrakis (pentafluorophenyl) boric acid (tetraphenylporphyrin iron chloride), tetrakis (pentafluoro) Phenyl) borate (tetraphenylporphyrin zinc), silver tetrafluoroborate, hexafluoroarsenate, silver hexafluoroantimonate, silver

Compounds other than those represented by formulas (V) and (VI), such as tri (pentafluorophenyl) boron, tri (3,3)
5-di (trifluoromethyl) phenyl) boron, triphenylboron and the like can also be used.

Examples of the organoaluminum compound as the component (C) include those represented by the following general formula (VII), (VIII) or (IX). R ¹² _r AlQ _3-r (VII) (R ¹² is a hydrocarbon group such as an alkyl group, an alkenyl group, an aryl group or an arylalkyl group having 1 to 20 carbon atoms, preferably 1 to ¹² carbon atoms, Q is a hydrogen atom, It represents an alkoxy group having 1 to 20 carbon atoms or a halogen atom, and r is in the range of 1 ≦ r ≦ 3. Examples of the compound of the formula (VII) include trimethylaluminum, triethylaluminum and triisopropyl. Aluminum, triisobutyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, methyl aluminum dichloride, ethyl aluminum dichloride, dimethyl aluminum fluoride, diisobutyl aluminum hydride, diethyl aluminum hydride, ethyl aluminum sesquichloride and the like can be mentioned.

[0047]

[Chemical 3] (R < ¹² > shows the same thing as a formula (VII). S shows a polymerization degree and is 3-50 normally, Preferably it is 7-40.) The chain | strand-shaped aluminoxane shown by these.

[0048]

[Chemical 4] (R ¹² represents the same as in formula (VII), s represents the degree of polymerization, and the preferred number of repeating units is 3 to 50, preferably 7 to 40.) Cyclic alkyl having a repeating unit Aluminoxane. Among the compounds represented by the formulas (VII) to (IX), an alkyl group-containing aluminum compound or aluminoxane having at least one alkyl group having 3 or more carbon atoms, and particularly having at least one branched alkyl group is preferable. Particularly preferred is triisobutylaluminum or aluminoxane having a degree of polymerization of 7 or more. When this triisobutylaluminum, aluminoxane having a degree of polymerization of 7 or more, or a mixture thereof is used, high activity can be obtained. Further, a modified aluminoxane obtained by modifying the aluminoxane represented by the formulas (VII) to (IX) with a compound having active hydrogen such as water is also preferably used.

As a method for producing the aluminoxane, there may be mentioned a method in which an alkylaluminum and a condensing agent such as water are brought into contact with each other, but the means therefor is not particularly limited, and the reaction may be carried out according to a known method. For example, a method in which an organoaluminum compound is dissolved in an organic solvent and brought into contact with water, a method in which an organoaluminum compound is initially added at the time of polymerization, and water is added later, water of crystallization contained in a metal salt, etc. There are a method of reacting water adsorbed on an inorganic substance or an organic substance with an organoaluminum compound, a method of reacting a tetraalkyldialuminoxane with a trialkylaluminum, and further reacting with water.

The catalyst used in the production of the olefinic copolymer of the present invention comprises the above-mentioned components (A) and (B) or (A),
The components (B) and (C) are the main components. In this case, the use conditions of the component (A) and the component (B) are not limited, but the ratio (molar ratio) of the component (A) to the component (B) is 1:
It is preferably 0.01 to 1: 100, particularly 1: 0.5 to 1:10, and particularly preferably 1: 1 to 1: 5. The operating temperature is preferably in the range of -100 to 250 ° C, and the pressure and time can be set arbitrarily.

The amount of the component (C) used is usually 0 to 2,000 mol, preferably 5 to 1 mol of the component (A).
The amount is 1,000 mol, particularly preferably 10 to 500 mol. When the component (C) is used, the polymerization activity can be improved, but if it is too much, a large amount of the organoaluminum compound remains in the polymer, which is not preferable.

The mode of use of the catalyst component is not limited, and for example, the components (A) and (B) may be contacted in advance, or the contact product may be separated and washed before use. You may use it by making a contact. Further, the component (C) may be used by being brought into contact with the contact product of the component (A), the component (B) or the component (A) and the component (B) in advance.
The contact may be made in advance or in the polymerization system. Further, the catalyst component can be added to the monomer or the polymerization solvent in advance, or can be added to the polymerization system. The catalyst component can be used by supporting it on an inorganic or organic carrier, if necessary.

The ratio of the catalyst to the reaction raw material is 1 to 10 ^{9 of} raw material monomer / component (A) (molar ratio) or raw material monomer / component (B) (molar ratio), especially 1
It is preferably from 00 to 10 ⁷ .

Polymerization methods include bulk polymerization, solution polymerization,
Any method such as suspension polymerization or gas phase polymerization may be used.
Further, a batch method or a continuous method may be used. When a polymerization solvent is used, for example, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane,
Aliphatic hydrocarbons such as pentane, hexane, heptane and octane, halogenated hydrocarbons such as chloroform and dichloromethane can be used. These solvents may be used alone or in combination of two or more. Further, a monomer such as α-olefin may be used as a solvent.

Regarding the polymerization conditions, the polymerization temperature is -100 to 2
The temperature is preferably 50 ° C, particularly preferably -50 to 200 ° C.
The polymerization time is usually 1 minute to 10 hours, and the reaction pressure is atmospheric pressure to 10
0 Kg / cm ² G, preferably normal pressure to 50 Kg / cm ² G
Is. The method for controlling the molecular weight of the copolymer can be selected by the amount of each catalyst component used, the polymerization temperature, and the polymerization reaction in the presence of hydrogen.

The stretched film of the present invention is obtained by uniaxially or biaxially stretching the original fabric (sheet or film) made of the above-mentioned cyclic olefin copolymer. In this case, in the stretched film of the present invention, the original fabric is 0 in the machine (MD) direction.
To 20 times, and preferably in the transverse (TD) direction from 0 to 20 times.

Here, as a method of forming the original fabric (sheet or film), a general sheet or film forming method such as a T-die method or an inflation method can be adopted. At this time, the thickness of the formed original fabric is not particularly limited, but the wall thickness is 0.01 to 5 mm, particularly 0.02 to 3 m.
It is preferably m. It should be noted that various additives and fillers can be added to the cyclic olefin-based copolymer forming the raw fabric (sheet or film). Examples of additives include heat resistance stabilizers, weather resistance stabilizers, antistatic agents, slip agents, antiblocking agents, antifogging agents, lubricants, foaming agents, dyes, pigments, natural oils, synthetic oils, waxes, and the like. The blending amount may be an appropriate amount. By stretching the thus formed raw fabric in the machine direction (MD) in the range of 0 to 20 times and in the transverse (TD) direction in the range of 0 to 20 times, the low temperature shrinkability of the present invention is excellent. It is possible to obtain a stretched film.

The stretching is carried out uniaxially or sequentially or simultaneously in the longitudinal direction and / or the transverse direction at a stretching temperature not lower than the glass transition temperature (Tg) and not higher than the softening point of the cyclic olefin copolymer. The stretching ratio in the longitudinal and transverse directions can be arbitrarily selected according to the required physical properties. In this case, in the production of the stretched film of the present invention, the stretching temperature is not particularly limited and Tg + 3
0 ° C to Tg + 150 ° C, especially Tg + 40 ° C to Tg + 10
The temperature is preferably 0 ° C. When the original fabric made of the cyclic olefin-based copolymer is stretched at a stretching temperature of Tg to Tg + 60 ° C. or Tg + 40 ° C. which is a normal stretching temperature, elastic recovery after the stretching is large and the stretching may not be performed sufficiently. is there. As the stretching means, general stretching means such as roll stretching, tenter stretching and inflation method can be adopted.

The preferred method for producing the stretched film of the present invention will be described in detail. First, a cyclic olefin copolymer is subjected to a T-die molding method, an inflation molding method or the like to have a wall thickness of 0.01 to 5 mm, preferably 0.02. ~ 3 mm
The original film or sheet is molded. Then, this raw fabric is uniaxially or sequentially or simultaneously stretched in the machine direction and / or the transverse direction at the above-mentioned stretching temperature.

Since the stretched film of the present invention has a low temperature shrinkability, it can be easily adjusted to any shape and can be effectively used as a packaging material for foods, medical products, transportation and the like. You can In this case, the stretched film of the present invention is excellent in transparency and also has a strength to protect an object to be packaged from external force such as shock, vibration, compression in the distribution process. The thickness of the stretched film of the present invention is not particularly limited, and the stretched film of the present invention includes a sheet form.

[0061]

EXAMPLES Next, the present invention will be specifically shown by Examples and Comparative Examples, but the present invention is not limited to the following Examples. First, prior to the production of the multilayer material, the following reference example 1,
A cyclic olefin-based copolymer of 2 was produced.

Reference Example 1 (Copolymerization of Ethylene and 2-Norbornene) Under a nitrogen atmosphere, at room temperature, 15 liters of toluene, 23 mmol of triisobutylaluminum (TIBA), 0.038 mmol of zirconium tetrachloride were added to a 30 liter autoclave. 0.060 mmol of anilinium tetra (pentafluorophenyl) borate was added in this order, and then 2.4 liters of a toluene solution containing 70% by weight of 2-norbornene (1 part as 2-norbornene was added).
6.0 mol) was added. After the temperature was raised to 80 ° C., the reaction was carried out for 110 minutes while continuously introducing ethylene so that the ethylene partial pressure became 8 kg / cm ² . After the reaction,
The polymer solution was poured into 15 liters of methanol to precipitate the polymer. This polymer was collected by filtration and dried to obtain a cyclic olefin-based copolymer (a1). The yield of the cyclic olefin-based copolymer (a1) was 2.93 Kg. The polymerization activity was 846 Kg / gZr.

The resulting cyclic olefin copolymer (a
The physical properties of 1) were as follows. 30 of ¹³ C-NMR
The sum of the peaks based on ethylene and the peaks based on methylene at the 5th and 6th positions of norbornene appearing around ppm and 3
The norbornene content calculated from the ratio with the peak based on the methylene group at the 7-position of norbornene appearing at around 2.5 ppm was 7.7 mol%. The intrinsic viscosity [η] measured in decalin at 135 ° C. was 1.01 dl / g, and the crystallinity determined by X-ray diffractometry was 1.0%. Vibron 11-EA manufactured by Toyo Boulding Co., Ltd. is used as a measuring device, and a measuring piece having a width of 4 mm, a length of 40 mm and a thickness of 0.1 mm is measured at a heating rate of 3 ° C./min and a frequency of 3.5 Hz. The glass transition temperature (Tg) was determined from the peak of the loss elastic modulus (E ″) of Tg was 0 ° C. ALC / GPC150C manufactured by Waters was used as a measuring device, and 1,2,4-trichlorobenzene solvent was used. When the weight average molecular weight Mw, the number average molecular weight Mn, and the molecular weight distribution (Mw / Mn) were calculated in terms of polyethylene at 135 ° C.,
Mw is 58,100, Mn is 30,400, Mw / Mn
Was 1.91. Perkin Elmer 7 series DSC at a temperature rising rate of 10 ° C./min.
The melting point (Tm) was measured in the range of 150 ° C.
Was 72 ° C. (broad peak) ° C.

Reference Example 2 (Copolymerization of Ethylene with 2-Norbornene) In Reference Example 1, 300 mmol of ethylaluminum sesquichloride was used instead of triisobutylaluminum, and VO (OC ₂ H ₅ ) C was used instead of zirconium tetrachloride.
l ₂ of 30 mmol and no anilinium tetra (pentafluorophenyl) borate were used, the amount of 2-norbornene used was 3 mol, the polymerization temperature was 30 ° C., the ethylene partial pressure was 1 Kg / cm ² , and the polymerization time was A cyclic olefin-based copolymer (a2) was obtained in the same manner as in Reference Example 1 except that the period was 30 minutes. The yield of the cyclic olefin-based copolymer (a2) was 480 g. Further, the norbornene content determined in the same manner as in Reference Example 1 was 24.6 mol%, the intrinsic viscosity [η] was 1.21 dl / g, and the melting point (Tm) was 100 ° C.
(Sharp peak), glass transition temperature (Tg) is 50
C., Mw / Mn was 4.26.

Next, examples and comparative examples using the cyclic olefin-based copolymer obtained in the above reference example will be shown. Examples 1-7, Comparative Examples 1-2 Cyclic olefin-based copolymers a1 and a2 were added at 190 ° C. for 1 hour.
Heat pressed at 00kg / cm ² for 3 minutes, thickness 100μm
I got the original film. From now on, length 20mm, width 10
A 0 mm test piece was cut out. After the test piece was uniaxially stretched at the stretching temperature and the stretching ratio shown in Table 1 and held for 1 minute,
Cooled. The stretching ratio of the test piece after releasing the stretching tension and the mechanical properties of the stretched film were measured. The results are shown in Table 1.

Here, each item was measured as follows. It was performed according to JIS-K7113 using a tensile modulus autograph. The tensile rupture strength autograph was performed according to JIS-K7113. Tensile elongation at break Autograph was performed according to JIS-K7113. Elastic recovery autograph, pulling speed 62mm / min, width 6m
m, 50 mm (L ₀ ) between clamps was stretched and stretched by 150%, held for 5 minutes, and then contracted suddenly without rebounding, and after 1 minute, the sheet length between clamps (L ₁ ) was measured and determined by the following formula. Elastic recovery rate (%) = [1-{(L ₁ −L ₀ ) / L ₀ }] ×
100 In this case, good elastic recovery is 10% or more, especially 30%
Above all, above 60%. Haze Digital Haze Computer (DIGITAL HAZE COMPU
TER) (manufactured by Suga Test Instruments Co., Ltd.) using JIS-K
The measurement was performed according to 7105. Heat shrinkage rate 6 mm wide, 40 mm long test piece with warm water (60 ℃ and 7
The length L ₂ (mm) after immersion in (0 ° C.) for 5 seconds was measured and determined by the following formula. Heat shrinkage (%) = [1- (L 2/40)] × 100

[0067]

[Table 1]

[0068]

As described above, the stretched film of the present invention is excellent in transparency, low temperature shrinkability and elastic recovery property, and further improved in tensile breaking strength and elastic recovery rate.

Claims (2)

[Claims] 1. A raw material comprising a cyclic olefin copolymer having a repeating unit derived from α-olefin and a repeating unit derived from cyclic olefin and having a glass transition temperature (Tg) of 30 ° C. or lower, uniaxially or A stretched film which is biaxially stretched. 2. The content of the repeating unit derived from a cyclic olefin in the cyclic olefin-based copolymer is 0.5 to
The stretched film according to claim 1, which is 20 mol%.