JP2003011301A - Multi-layer film of polypropylene resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layer film of a polypropylene resin excellent in low temperature heat sealing properties. SOLUTION: The multi-layer film of the polypropylene resin is composed of a surface layer (A) of a propylene/α-olefin copolymer having (A-i) MFR of 0.1-30 g/10 m, (A-ii) Mw/Mn by a gel permeation chromatography method of 1.8-3.5, and (A-iii) a melting point measured by a differential scanning calorimeter of 100-140 deg.C and a layer (B) of a propylene/α-olefin copolymer having (B-i) MFR of 0.1-30 g/10 m, (B-ii) Mw/Mn by a gel permeation chromatography method of 3.6-6.0, and (B-iii) a melting point measured by a differential scanning calorimeter of 120-145 deg.C. The layer (B) is formed adjacently to the surface layer (A).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene resin multilayer film, and more particularly to a polypropylene resin multilayer film suitable as a sealant.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Polypropylene film is excellent in mechanical strength, food hygiene, chemical resistance, heat resistance and heat sealability. Therefore, it is used as a sealant by laminating with other films. There is. As a sealant, (1) excellent heat sealability, specifically, (i) heat seal at low temperature, (ii) good hot tack property up to low temperature, (iii) heat seal start temperature It is required that the change is small, (2) the blocking resistance is excellent, and (3) the slip property is excellent.

In order to be able to heat seal a polypropylene film at a low temperature, it is necessary to use polypropylene having a low melting point. Generally, to lower the melting point of polypropylene, the method of increasing the copolymerization amount of other α-olefin with propylene is adopted, but the propylene / α-olefin copolymer produced by titanium catalyst has a low molecular weight and α-olefin component. However, there is a problem that a large amount of n-decane extractables is produced, resulting in a large change with time in the heat-sealing start temperature and deterioration in blocking resistance.

Japanese Unexamined Patent Publication (Kokai) No. 11-293063 discloses that a propylene / α-olefin copolymer produced by a metallocene catalyst is preferable because it has a small amount of extracted n-decane. However, the propylene / α-olefin copolymer produced by the metallocene catalyst is not sufficient because of lack of hot tack property.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polypropylene resin multilayer film having excellent low temperature heat sealability. A second object of the present invention is to provide a polypropylene resin multi-layer film with little change in low temperature heat sealability.

Another object of the present invention is to provide a polypropylene resin multilayer film having excellent blocking resistance. Another object of the present invention is to provide a polypropylene resin multilayer film having excellent hot tack property.

[0007]

SUMMARY OF THE INVENTION The polypropylene resin multilayer film according to the present invention is (A-i) melt flow rate (ASTM D
1238, 230 ° C, load 2.16 kg) is 0.1-3
It is in the range of 0 g / 10 minutes and has an Mw / Mn of 1.8 to 3.5 by (A-ii) gel permeation chromatography.
And (A-iii) a surface layer (A) composed of a propylene / α-olefin copolymer having a melting point (Tm) measured by a differential scanning calorimeter of 100 ° C. to 140 ° C. B-i) Melt flow rate (ASTM D
1238, 230 ° C, load 2.16 kg) is 0.1-3
It is in the range of 0 g / 10 minutes and has a Mw / Mn of (B-ii) gel permeation chromatography of 3.6 to 6.0.
And a melting point (Tm) measured by a differential scanning calorimeter (B-iii) in the range of 120 ° C. to 145 ° C. and a layer (B) made of a propylene / α-olefin copolymer, It is characterized in that the layer (B) is provided adjacent to the surface layer (A).

In the present invention, the propylene / α-olefin copolymer (A) is preferably produced by a metallocene catalyst, and the propylene / α-olefin copolymer (B) is a Ziegler catalyst. It is preferable that it is manufactured by.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polypropylene resin multilayer film according to the present invention will be specifically described below. The propylene resin multilayer film according to the present invention is formed from (A) propylene / α-olefin copolymer and (B) propylene / α-olefin copolymer.

(A) Propylene / α-olefin copolymerization
Body The propylene / α-olefin copolymer (A) forming the propylene resin multilayer film according to the present invention is propylene and an α-olefin other than propylene (hereinafter, also simply referred to as “other α-olefin”). ) Is a random copolymer with. Examples of other α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadecene, 4-methyl-1-pentene. 2 and 4 carbon atoms such as
.About.20 .alpha.-olefins. These other α-
Of the olefins, ethylene and / or 1-butene are preferred.

The propylene / α-olefin copolymer (A) contains a repeating unit derived from propylene in a proportion of preferably 80 to 99 mol%, more preferably 85 to 95 mol%, and derived from another α-olefin. The repeating unit is preferably 1 to 20 mol%, more preferably 5
It is contained in the range of up to 15 mol%. The propylene / α-olefin copolymer (A) used in the present invention satisfies the following requirements (Ai) to (A-iii). (Ai) Melt flow rate (MFR; ASTM D 1
238, 230 ° C, load 2.16 kg) is 0.1-30
g / 10 minutes, preferably 1.0 to 20 g / 10 minutes, particularly preferably 3.0 to 15 g / 10 minutes.

Propylene / α having MFR within the above range
-The olefin copolymer (A) has excellent extrusion moldability,
Moreover, it is possible to provide a sealant having an appropriate sheet seal strength. (A-ii) Weight average molecular weight (Mw) and number average molecular weight (Mw) determined by gel permeation chromatography
The ratio (Mw / Mn) with n) is in the range of 1.3 to 3.5, preferably 1.5 to 3.0, and particularly preferably 1.7 to 2.7.

The propylene / α-olefin copolymer (A) has a ratio (Mz / Mz) of Z average molecular weight (Mz) to Mw.
Mw) is preferably in the range of 1.3 to 2.5, particularly preferably 1.5 to 2.4. Mw / Mn and Mz /
When the Mw is in the above range, a film having a small amount of low molecular weight components and a small change in heat sealability over time can be obtained. (A-iii) Melting point (T measured by a differential scanning calorimeter
m) is 100 to 140 ° C., particularly preferably 105 to 1
It is in the range of 30 ° C.

When the melting point is within this range, blocking is difficult and the low temperature heat sealability is excellent. Production Method of Propylene / α-Olefin Copolymer (A) The propylene / α-olefin copolymer (A) as described above can be produced using, for example, a metallocene catalyst.

The metallocene catalyst used in the present invention is
(A) a transition metal compound as described below, and (b) (b-
1) Organoaluminum oxy compound and / or (b-
2) A metallocene catalyst composed of a compound that reacts with the transition metal compound (a) to form an ion pair and, if desired, (c) an organoaluminum compound.

(Transition Metal Compound (a)) The transition metal compound (a) (hereinafter sometimes referred to as “component (a)”) used in the present invention is represented by the following general formula (I). MLx (1) In the formula, M is a transition metal selected from Groups 4, 5 and 6 of the periodic table, and specifically, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten. And preferably titanium, zirconium or hafnium, and particularly preferably zirconium.

In the general formula (1), L is a ligand that coordinates with a transition metal, and at least one of these ligands L
Is a ligand having a cyclopentadienyl skeleton, and this ligand having a cyclopentadienyl skeleton may have a substituent. When there are a plurality of ligands L, L may be the same or different. As the ligand having a cyclopentadienyl skeleton, for example, cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclopentadienyl group, methylpropylcyclopentadienyl group, methylbutylcyclopentadienyl group, Alkyl- or cycloalkyl-substituted cyclopentadienyl group such as methylhexylcyclopentadienyl group and methylbenzylcyclopentadienyl group, further indenyl group, 4,5,
Examples include 6,7-tetrahydroindenyl group and fluorenyl group. These groups may be substituted with a halogen atom, a trialkylsilyl group or the like.

The compound represented by the general formula (1) is a ligand L
When having two or more groups having a cyclopentadienyl skeleton, the groups having two cyclopentadienyl skeletons are alkylene groups such as ethylene and propylene; substituted alkylenes such as isopropylidene and diphenylmethylene. Group: It is desirable that the group is bonded via a silylene group or a substituted silylene group such as a dimethylsilylene group, a diphenylsilylene group, and a methylphenylsilylene group.

Ligand having cyclopentadienyl skeleton
Other than L is a hydrocarbon group having 1 to 12 carbon atoms,
Alkoxy group, aryloxy group, sulfonic acid-containing group (-
SO ₃R¹), A halogen atom or a hydrogen atom (where R is
¹Is an alkyl group, alkyl substituted with a halogen atom
Group, aryl group or halogen atom or alkyl group
It is an aryl group substituted with. ) And the like.

The transition metal compound (a) represented by the general formula (1) is more specifically represented by the following general formula (2) when the valence of the transition metal is 4, for example. R ² _k R ³ _l R ⁴ _m R ⁵ _n M (2) In the general formula (2), M is a transition metal similar to M in the general formula (1), and R ² is a cyclopentadienyl skeleton. R ³ , R ⁴ and R ⁵ each independently represent a group having a cyclopentadienyl skeleton or a ligand having a cyclopentadienyl skeleton in the general formula (1). Other than L is the same. k is an integer of 1 or more, and k +
1 + m + n = 4.

In the present invention, a transition metal compound represented by the following general formula (3) can be used as the transition metal compound (a).

[0022]

[Chemical 1]

In the general formula (3), M represents a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium. In the general formula (3), R ¹¹ and R ¹² are each independently a hydrogen atom, a halogen atom, or a carbon atom number of 1 to 1.
20 hydrocarbon groups, halogenated hydrocarbon groups having 1 to 20 carbon atoms, silicon-containing groups, oxygen-containing groups, sulfur-containing groups,
Represents a nitrogen-containing group or a phosphorus-containing group, specifically, a halogen atom such as fluorine, chlorine, bromine, or iodine; methyl,
Alkyl groups such as ethyl, propyl, butyl, hexyl, cyclohexyl, octyl, nonyl, dodecyl, eicosyl, norbornyl and adamantyl, alkenyl groups such as vinyl, propenyl and cyclohexenyl, arylalkyl such as benzyl, phenylethyl and phenylpropyl. Group, a phenyl, tolyl, dimethylphenyl, trimethylphenyl, ethylphenyl, propylphenyl, biphenylyl, naphthyl, methylnaphthyl, anthryl, aryl group and other aryl groups, and other hydrocarbon groups having 1 to 20 carbon atoms; Halogenated hydrocarbon group having 1 to 20 carbon atoms substituted with a halogen atom; monohydrocarbon-substituted silyl such as methylsilyl and phenylsilyl; dihydrocarbon-substituted silyl such as dimethylsilyl and diphenylsilyl. Trihydrocarbyl-substituted silyl such as trimethylsilyl, triethylsilyl, tripropylsilyl, tricyclohexylsilyl, triphenylsilyl, dimethylphenylsilyl, methyldiphenylsilyl, tritolylsilyl, and trinaphthylsilyl, and hydrocarbyl-substituted silyl such as trimethylsilyl ether. Silicon-containing groups such as ethers, silicon-substituted alkyl groups such as trimethylsilylmethyl, silicon-substituted aryl groups such as trimethylsilylphenyl; alkoxy groups such as hydroxy group, methoxy, ethoxy, propoxy, butoxy, phenoxy, methylphenoxy, dimethylphenoxy, naphthoxy. An oxygen-containing group such as an aryloxy group such as an arylalkoxy group such as phenylmethoxy or phenylethoxy; Sulfur containing groups such substituent substituting U; amino group, methylamino, dimethylamino, diethylamino, dipropylamino, dibutylamino, alkylamino group such as dicyclohexyl amino, phenylamino, diphenylamino,
Nitrogen-containing groups such as arylamino groups or alkylarylamino groups such as ditolylamino, dinaphthylamino and methylphenylamino; phosphorus-containing groups such as phosphino groups such as dimethylphosphino and diphenylphosphino.

In the general formula (3), R ¹¹ is preferably a hydrocarbon group, and particularly preferably a hydrocarbon group having 1 to 3 carbon atoms such as methyl, ethyl and propyl. R ¹² is preferably a hydrogen atom or a hydrocarbon group,
It is particularly preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms such as methyl, ethyl or propyl.
In formula (3), R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom, a halogen atom, or a carbon atom number of 1 to 20.
And a halogenated hydrocarbon group having 1 to 20 carbon atoms.

Examples of the halogen atom include fluorine, chlorine, bromine and iodine. As the hydrocarbon group having 1 to 20 carbon atoms, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclohexyl, heptyl,
Chain alkyl groups and cyclic alkyl groups such as octyl, nonyl, dodecyl, eicosyl, norbornyl, adamantyl; arylalkyl groups such as benzyl, phenylethyl, phenylpropyl, tolylmethyl, etc., and hydrocarbon groups are double bonds, It may contain a triple bond.

Examples of the halogenated hydrocarbon group having 1 to 20 carbon atoms include groups in which the above hydrocarbon group is substituted with a halogen atom. Of R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ ,
Two groups including R ¹³ are preferably alkyl groups, and R ¹³ and R ¹⁵ or R ¹³ and R ¹⁶ are preferably alkyl groups. This alkyl group is preferably a secondary or tertiary alkyl group. Further, this alkyl group may be substituted with a halogen atom, a silicon-containing group or the like, and as the halogen atom or the silicon-containing group, the above R ¹¹ ,
Examples thereof include the substituents exemplified for R ¹² .

In the general formula (3), R ¹³ , R ¹⁴ and R ¹⁵
When 1 to 3 groups of R ¹⁶ and R ¹⁶ are alkyl groups, the groups other than the alkyl groups are preferably hydrogen atoms. In the general formula (3), R ¹³ ,
Two kinds of groups selected from R ¹⁴ , R ¹⁵ and R ¹⁶ may be bonded to each other to form a monocyclic or polycyclic ring other than the aromatic ring.

In the general formula (3), X ¹ and X ² are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, or oxygen. A containing group or a sulfur containing group, specifically, the same halogen atom as R ¹¹ and R ¹² , a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, oxygen The containing group can be exemplified.

Examples of the sulfur-containing group include the same groups as R ¹¹ and R ¹² described above, methyl sulfonate, trifluoromethane sulfonate, phenyl sulfonate, benzyl sulfonate, p-toluene sulfonate and trimethylbenzene sulfonate. Sulfonate groups such as phonate, triisobutylbenzene sulfonate, p-chlorobenzene sulfonate, pentafluorobenzene sulfonate, methylsulfinate, phenylsulfinate, benzylsulfinate, p-toluenesulfinate Examples thereof include sulfinate groups such as trimethylbenzenesulfinate and pentafluorobenzenesulfinate.

In the general formula (3), Y has 1 to 20 carbon atoms.
A divalent hydrocarbon group, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group, a divalent tin-containing group, -O-,- CO-,
-S -, - SO -, - SO 2 -, - NR 17 -, - P
^{(R 17) -, - P} (O) (R 17) -, - BR 17 - or AlR
^17- (provided that R ¹⁷ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a halogenated hydrocarbon group having 1 to 20 carbon atoms), and specifically, methylene and dimethylmethylene. , 1,2-ethylene, dimethyl-1,2-
Ethylene, 1,3-trimethylene, 1,4-tetramethylene, 1,
1-carbon atoms such as alkylene groups such as 2-cyclohexylene and 1,4-dichlorohexylene, aryl alkylene groups such as diphenylmethylene and diphenyl-1,2-ethylene
20 divalent hydrocarbon groups; halogenated hydrocarbon groups obtained by halogenating the above C 1-20 divalent hydrocarbon groups such as chloromethylene; methylsilylene, dimethylsilylene, diethylsilylene, di (n- Propyl) silylene,
Di (i-propyl) silylene, di (cyclohexyl) silylene, methylphenylsilylene, diphenylsilylene,
Alkylsilylenes such as di (p-tolyl) silylene and di (p-chlorophenyl) silylene, alkylarylsilylenes, arylsilylenes, alkylmethylsilylenes such as tetramethyl-1,2-disilylene, tetraphenyl-1,2-disilylene, A divalent silicon-containing group such as an alkylaryldisilirene or an aryldisilirene group; a divalent germanium-containing group obtained by substituting germanium for silicon in the divalent silicon-containing group; tin for the silicon in the divalent silicon-containing group A divalent tin-containing group substituted with
¹⁷ is the same halogen atom as R ¹¹ and R ¹² , a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, and the like.

Of these, a divalent silicon-containing group, a divalent germanium-containing group and a divalent tin-containing group are preferable, and a divalent silicon-containing group is more preferable,
Of these, alkylsilylene, alkylarylsilylene, and arylsilylene are particularly preferable. The transition metal compound represented by the above general formula (3) is specifically exemplified below. rac-Dimethylsilylene-bis {1- (2,7-dimethyl-4-ethylindenyl)} zirconium dichloride, rac-Dimethylsilylene-bis {1- (2,7-dimethyl-4-)
n-propylindenyl)} zirconium dichloride, ra
c-Dimethylsilylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7-dimethyl-4-n-butylindene) Nil)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7-dimethyl-4-sec-butylindenyl)} zirconium dichloride, rac-dimethylsilylene
-Bis {1- (2,7-dimethyl-4-t-butylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1
-(2,7-Dimethyl-4-n-pentylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7
-Dimethyl-4-n-hexylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7-dimethyl-4-cyclohexylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7-Dimethyl-4-methylcyclohexylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7
-Dimethyl-4-phenylethylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,7-
Dimethyl-4-phenyldichloromethylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1
-(2,7-Dimethyl-4-chloromethylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1-
(2,7-Dimethyl-4-trimethylsilylenemethylindenyl)} zirconium dichloride, rac-dimethylsilylene
-Bis {1- (2,7-dimethyl-4-trimethylsiloxymethylindenyl)} zirconium dichloride, rac-diethylsilylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} zirconium Dichloride, rac-di (i-propyl) silylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} zirconium dichloride, rac-di (n-butyl) silylene-bis {1- ( 2,7-Dimethyl-4-i-propylindenyl)} zirconium dichloride, rac-di (cyclohexyl) silylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} zirconium dichloride, rac -Methylphenylsilylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} zirconium dichloride, rac-methylphenylsilylene-bis {1- (2,7-dimethyl-4-t-butyl) Indenyl)} zirconium dichloride, rac-diphenyl Ren-bis {1- (2,7-dimethyl-4-t-butylindenyl)} zirconium dichloride, rac-diphenylsilylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} Zirconium dichloride, rac-diphenylsilylene-bis {1- (2,7-dimethyl-4-ethylindenyl)} zirconium dichloride, rac-di (p-tolyl) silylene-
Bis {1- (2,7-dimethyl-4-i-propylindenyl)}
Zirconium dichloride, rac-di (p-chlorophenyl)
Silylene-bis {1- (2,7-dimethyl-4-i-propylindenyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2-methyl-4-i-propyl-7-ethylindenyl) )} Zirconium dibromide rac-dimethylsilylene
-Bis {1- (2,7-dimethyl-4-i-propylindenyl)}
Zirconium dimethyl, rac-dimethylsilylene-bis {1
-(2,7-Dimethyl-4-i-propylindenyl)} zirconium methyl chloride, rac-dimethylsilylene-bis {1-
(2,7-Dimethyl-4-i-propylindenyl)} zirconium-bis (trifluoromethanesulfonato), rac-dimethylsilylene-bis {1- (2,7-dimethyl-4-i-propylindenyl) } Zirconium-bis (p-phenylsulfinato), rac-dimethylsilylene-bis {1- (2-phenyl-4-i-propyl-7-methylindenyl)} zirconium dichloride and the like.

((B-1) Organoaluminum Oxy Compound) The metallocene catalyst used in the present invention is formed (b-
1) Organoaluminum oxy compound (hereinafter “component (b-
1) ”. ) May be a conventionally known aluminoxane, or may be a benzene-insoluble organic aluminum oxy compound as exemplified in JP-A-2-78687.

The conventionally known aluminoxane can be produced, for example, by the following method. (1) Compounds containing adsorbed water or salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate,
A method in which an organoaluminum compound such as trialkylaluminum is added to a hydrocarbon medium suspension such as aluminum sulfate hydrate, nickel sulfate hydrate, and ceric chloride hydrate to react. (2) A method in which water, ice, or water vapor is allowed to directly act on an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran. (3) A method of reacting an organoaluminum compound such as trialkylaluminum with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a medium such as decane, benzene or toluene.

The aluminoxane may contain a small amount of organometallic component. Further, the solvent or unreacted organoaluminum compound may be removed by distillation from the recovered solution of the aluminoxane, and then redissolved in the solvent or suspended in a poor solvent for the aluminoxane. Specifically as the organoaluminum compound used in preparing the aluminoxane, trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, trisec-butylaluminum, tritert- Trialkyl aluminum such as butyl aluminum, tripentyl aluminum, trihexyl aluminum, trioctyl aluminum, tridecyl aluminum; tricycloalkyl aluminum such as tricyclohexyl aluminum and tricyclooctyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diethyl aluminum bromide Dialkyl aluminum such as diisobutyl aluminum chloride Umuharaido diethyl aluminum hydride, dialkylaluminum hydride such as diisobutylaluminum hydride; dimethyl aluminum methoxide, dialkylaluminum alkoxides such as diethylaluminum ethoxide; and dialkylaluminum Ally Loki Sid such as diethyl aluminum phenoxide and the like.

Of these, trialkylaluminum and tricycloalkylaluminum are preferable, and trimethylaluminum is particularly preferable. In addition, isoprenylaluminum can also be used as the organoaluminum compound used when preparing the aluminoxane. Solvents used for preparing a solution or suspension of aluminoxane include aromatic hydrocarbons such as benzene, toluene, xylene, cumene and cymene; fats such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane and octadecane. Group hydrocarbons; cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane, cyclooctane, and methylcyclopentane; petroleum fractions such as gasoline, kerosene, and light oil, or the above aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons And hydrocarbon solvents such as chlorides, bromides and the like. In addition, ethers such as ethyl ether and tetrahydrofuran can also be used. Of these solvents, aromatic hydrocarbons or aliphatic hydrocarbons are particularly preferable.

((B-2) Compound which reacts with the transition metal compound (a) to form an ion pair) (b-2) The transition metal compound (a) which forms the metallocene catalyst used in the present invention. Examples of the compound that reacts to form an ion pair (hereinafter sometimes referred to as “component (b-2)”) are JP-A-1-501950, JP-A-1-502036, and JP-A-3-50320. 179005, Japanese Patent Laid-Open No. 3-17
Examples thereof include Lewis acids, ionic compounds and carborane compounds described in JP-A-9006, JP-A-3-207703, JP-A-3-207704, US-5321106 and the like.

As the Lewis acid, triphenylboron,
Tris (4-fluorophenyl) boron, Tris (p-tolyl) boron, Tris (o-tolyl) boron, Tris (3,5-
Dimethylphenyl) boron, Tris (pentafluorophenyl) boron, MgCl ₂ , Al ₂ O ₃ , SiO ₂ -Al ₂
Examples include O _{3 and the} like. Ionic compounds include triphenylcarbenium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, ferrocenium tetra Examples thereof include (pentafluorophenyl) borate.

Examples of the carborane compound include dodecaborane, 1-carbaundecaborane, bis-n-butylammonium (1-carbedodeca) borate, tri-n-butylammonium (7,8-dicarbaundeca) borate and tri-n-butylammonium. (Trideca hydride-7-carbaundeca) borate etc. can be illustrated. The compound (b-2) which reacts with the transition metal compound (a) as described above to form an ion pair can be used as a mixture of two or more kinds.

((C) Organoaluminum Compound) As (c) an organoaluminum compound (hereinafter sometimes referred to as “component (c)”) that can be used when forming the metallocene catalyst used in the present invention. Specifically, the following compounds may be mentioned. Trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, tri (2-ethylhexyl) aluminum and tridecylaluminum; alkenylaluminums such as isoprenylaluminum; dimethylaluminum chloride and diethylaluminum chloride. Dialkyl aluminum halides such as diisopropyl aluminum chloride, diisobutyl aluminum chloride and dimethyl aluminum bromide; methyl aluminum sesquichloride, ethyl aluminum sesquichloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride,
Alkyl aluminum sesquihalides such as ethyl aluminum sesquibromide; alkyl aluminum dihalides such as methyl aluminum dichloride, ethyl aluminum dichloride, isopropyl aluminum dichloride and ethyl aluminum dibromide; alkyl aluminum hydrides such as diethyl aluminum hydride and diisobutyl aluminum hydride.

Such an organoaluminum compound (c)
Is also used as the following organoaluminum compound (e). (Catalyst Preparation Method) The metallocene catalyst used in the present invention is
It is formed from the above component (a), component (b-1) and / or component (b-2) (hereinafter also referred to as "component (b)") and, if desired, component (c). The metallocene catalyst can be prepared by mixing the component (a), the component (b) and optionally the component (c) in an inert hydrocarbon solvent or an olefin solvent.

As the inert hydrocarbon solvent used for preparing the metallocene catalyst, specifically, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosene; cyclopentane, Examples thereof include alicyclic hydrocarbons such as cyclohexane and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane, or a mixture thereof.

The order of mixing the respective components in preparing the metallocene catalyst is arbitrary, but the components (b) and (a) may be mixed, or the components (b) and (c) may be mixed. Then component (a) is mixed, component (a) and component (b) are mixed, then component (c) is mixed, or component (a) and component (c) are mixed, It is then preferred to mix component (b).

When the above components are mixed in a solvent,
It is desirable that the concentration of the component (a) is about 10 ^-8 to 10 ^-1 mol / liter, preferably 10 ^{-7 to} 5 × 10 ^-2 mol / liter. When the component (b-1) is used as the component (b), the aluminum in the component (b-1) is
Atomic ratio with transition metal in component (a) (Al / transition metal)
And usually 10 to 10,000, preferably 20 to 5,000.
And when the component (b-2) is used, the molar ratio of the component (a) and the component (b-2) (the component (a)
/ Component (b-2)) is usually used in an amount of 0.00.1-10, preferably 0.1-5.

[0044] Component (c), the atomic ratio of aluminum atom (Al _c) and component in component (c) (b-1) aluminum atom in the _{(Al b-1) (Al} c / Al b-1 ) Is usually 0.02 to 20, preferably 0.2 to 10, and can be used as necessary. The metallocene catalyst used in the present invention comprises an inorganic or organic fine particle carrier which is a granular or fine particle solid, and at least one of the above-mentioned components (a), (b) and (c). It may be a supported solid catalyst.

The inorganic carrier is preferably a porous oxide, and examples thereof include SiO ₂ and Al ₂ O ₃ . Examples of the granular or fine particle solid of the organic compound include polymers or copolymers containing ethylene, propylene, α-olefin such as ethylene, or styrene as a main component. Further, in the present invention, an olefin may be prepolymerized and used as each component forming the metallocene catalyst as described above. As the olefin used in the prepolymerization, propylene,
Ethylene, 1-butene and the like are preferable, but a mixture of these and other olefin may be used.

(Polymerization) Propylene used in the present invention
The α-olefin copolymer (A) can be produced by copolymerizing propylene and another α-olefin in the presence of the above metallocene catalyst so as to finally have the above composition ratio. . The polymerization can be carried out by any of liquid phase polymerization methods such as suspension polymerization and solution polymerization, or gas phase polymerization methods. In the liquid phase polymerization method, the same solvent as the inert hydrocarbon solvent used in the catalyst preparation described above can be used as a polymerization solvent, and propylene can also be used as a polymerization solvent.

The polymerization temperature is such that when carrying out the suspension polymerization method.
Is usually -50 to 100 ° C, preferably 0 to 90 ° C.
When carrying out the solution polymerization method,
0 to 250 ° C, preferably 20 to 200 ° C
desirable. Also, when carrying out the gas phase polymerization method, the polymerization temperature
The degree is usually 0 to 120 ° C, preferably 20 to 100 ° C.
Is desirable. The polymerization pressure is usually from atmospheric pressure to 9.8M.
Pa (100 kg / cm ²), Preferably atmospheric pressure to 4.9.
MPa (50 kg / cm²) Conditions, the polymerization reaction
Is a batch type, semi-continuous type, continuous type
Can also be done. In addition, polymerization is performed under different reaction conditions 2
It is also possible to divide into more than one step.

(B) Propylene / α-olefin copolymerization
Body The propylene / α-olefin copolymer (B) forming the propylene resin multilayer film according to the present invention is a random copolymer of propylene and an α-olefin other than propylene. Examples of the other α-olefin include those similar to the above, and among the other α-olefins, ethylene and / or 1-butene are preferable.

The propylene / α-olefin copolymer (B) has a repeating unit derived from propylene in the range of preferably 80 to 99 mol%, more preferably 90 to 97 mol%, and derived from another α-olefin. The repeating unit is preferably 1 to 20 mol%, more preferably 3
It is contained in the range of 10 mol%. The propylene / α-olefin copolymer (B) used in the present invention satisfies the following requirements (Bi) to (B-iii). (Bi) Melt Flow Rate (MFR; ASTM D 1238, 230
C., load 2.16 kg) is 0.1 to 30 g / 10 minutes, preferably 1.0 to 20 g / 10 minutes, particularly preferably 3.0 to
It is in the range of 15 g / 10 minutes. (B-ii) Weight average molecular weight (Mw) and number average molecular weight (M) determined by gel permeation chromatography
The ratio (Mw / Mn) with n) is in the range of 3.6 to 6.0, preferably 3.8 to 5.5, and particularly preferably 4.0 to 5.3. (B-iii) Melting point (Tm) by differential scanning calorimeter is 1
It is in the range of 20 ° C to 145 ° C, preferably 123 ° C to 142 ° C, and particularly preferably 125 to 140 ° C.

When the above requirements (Bi) to (B-iii) are satisfied,
It is possible to obtain a multilayer film having excellent moldability, hot tackiness, and heat sealability. (Production method of propylene / α-olefin copolymer (B))
The propylene / α-olefin copolymer (B) as described above is, for example, (d) a solid catalyst component containing magnesium, titanium, halogen and an electron donor (g) as essential components, (e) an organoaluminum compound, And (f) a Ziegler catalyst system comprising an electron donor, and can be produced by copolymerizing propylene with another α-olefin.

<Solid catalyst component (d)> The solid catalyst component (d) is prepared by a known method by bringing the following titanium compound, magnesium compound and electron donor (g) into contact with each other. As the magnesium compound used for preparing the solid catalyst component (d), a magnesium compound having a reducing ability having a magnesium-carbon bond or a magnesium-hydrogen bond, or a magnesium compound having no reducing ability can be used.

Specific examples of the magnesium compound having a reducing ability include dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, dihexyl magnesium, butyl ethyl magnesium, ethyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride and butyl ethoxy magnesium. , Butyl magnesium hydride and the like. These magnesium compounds having reducing ability may be used in the form of a complex compound with an organoaluminum compound.

On the other hand, specific examples of the magnesium compound having no reducing ability include dihalogenated magnesium compounds such as magnesium dichloride, magnesium dibromide and magnesium diiodide; methoxymagnesium chloride, ethoxymagnesium chloride,
Alkoxy magnesium halide compounds such as butoxy magnesium chloride, isopropoxy magnesium chloride, phenoxy magnesium chloride; dialkoxy magnesium compounds such as diethoxy magnesium, dibutoxy magnesium, diisopropoxy magnesium, diphenoxy magnesium; magnesium laurate, magnesium stearate, etc. And magnesium carboxylic acid salts thereof. These magnesium compounds having no reducing ability may be previously synthesized or may be synthesized from a magnesium compound having reducing ability at the time of preparing the solid catalyst component by a known method.

The catalyst used in the preparation of the solid catalyst component (d)
Specific examples of the tan compound are represented by the following formula.
A tetravalent titanium compound can be mentioned. Ti (OR)_gX_4-g (In the formula, R is a hydrocarbon group, and X is a halogen atom.
And g is 0 ≦ g ≦ 4. ) As such a titanium compound, specifically, TiCl
_Four, TiBr_Four, TiI_Four Tetrahalogenated titanium such as
N; Ti (OCH₃) Cl₃, Ti (OC₂H_Five) Cl₃, Ti
(O-n-C_FourH₉) Cl₃, Ti (OC₂H_Five) Br₃, Ti (O-i
so-C_FourH₉) Br₃ Trihalogenated alkoxy titanium such as
N; Ti (OCH₃)₂Cl₂, Ti (OC₂H_Five)₂Cl₂, T
i (O-n-C_FourH₉)₂Cl₂, Ti (OC₂H_Five)₂Br₂ Such as
Dihalogenated dialkoxytitanium; Ti (OCH₃)₃C
l, Ti (OC₂H_Five)₃Cl, Ti (O-n-C_FourH₉)₃Cl,
Ti (OC₂H_Five)₃Monohalogenated Trialco such as Br
Xytitanium; Ti (OCH₃)_Four, Ti (OC₂H_Five)_Four, Ti
(O-n-C_FourH₉)_Four, Ti (O-iso-C_FourH ₉)_Four, Ti (O-2-D
(Tilhexyl)_Four Such as tetraalkoxy titanium
It can be illustrated.

The electron donor (g) used in the preparation of the solid catalyst component (d) and the electron donor (f) as the catalyst component include alcohols, phenols, ketones, aldehydes, carboxylic acids, Organic acid halide, organic acid or inorganic acid ester, ether, acid amide, acid anhydride, ammonia, amine, nitrile, isocyanate,
Examples thereof include nitrogen-containing cyclic compounds and oxygen-containing cyclic compounds. Of these, carboxylic acids, carboxylic acid anhydrides, carboxylic acid esters, carboxylic acid halides, alcohols and ethers are preferably used.

More specifically, as alcohols,
Methanol, ethanol, propanol, butanol,
Pentanol, hexanol, 2-ethylhexanol,
C1-C18 alcohols such as octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropyl alcohol, isopropylbenzyl alcohol, carbon such as trichloromethanol, trichloroethanol, trichlorohexanol, etc. Examples thereof include halogen-containing alcohols having 1 to 18 atoms.

Examples of the phenols include phenols having 6 to 20 carbon atoms which may have a lower alkyl group such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol and naphthol. . Examples of the ketones include ketones having 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone and benzoquinone.

Examples of aldehydes include aldehydes having 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde and naphthaldehyde. As carboxylic acids, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, pivalic acid, acrylic acid, methacrylic acid, crotonic acid and other aliphatic monocarboxylic acids, malonic acid, succinic acid, glutaric acid. , Adipic acid, sebacic acid, maleic acid, fumaric acid and other aliphatic dicarboxylic acids, tartaric acid and other aliphatic oxycarboxylic acids, cyclohexanemonocarboxylic acid, cyclohexenemonocarboxylic acid, cis-1,2-cyclohexanedicarboxylic acid, cis-
Alicyclic carboxylic acids such as 4-methylcyclohexene-1,2-dicarboxylic acid, benzoic acid, toluic acid, anisic acid, p-tertiary butyl benzoic acid, naphthoic acid, cinnamic acid and other aromatic monocarboxylic acids , Phthalic acid, isophthalic acid, terephthalic acid, naphthalic acid, trimellitic acid, hemimellitic acid, trimesic acid, pyromellitic acid, and aromatic polycarboxylic acids such as mellitic acid.

As the carboxylic acid anhydrides, the above-mentioned carboxylic acid anhydrides can be used. Examples of the organic acid halides include acid halides having 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride, and anisic acid chloride.

Examples of organic or inorganic acid esters include methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate,
Examples include methyl chloroacetate. Compounds containing a sulfur atom, thiophenol, thiophene, ethyl 2-thiophenecarboxylate, ethyl 3-thiophenecarboxylate, 2-methylthiophene, methyl mercaptan, ethyl mercaptan, isopropyl mercaptan, butyl mercaptan, diethyl thioether, diphenyl thioether, benzene Methyl sulfonate, methyl sulfite, ethyl sulfite and the like can be mentioned.

As the compound containing an oxygen atom, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 2-ethyltetrahydrofuran, 2,2,5,
5-tetraethyltetrahydrofuran, 2,2,5,5-tetramethyltetrahydrofuran, 2,2,6,6-tetraethyltetrahydropyran, 2,2,6,6-tetramethyltetrahydropyran, dioxane, dimethyl ether, diethyl ether, di Butyl ether diisoamyl ether, diphenyl ether, anisole, acetophenone, acetone,
Methyl ethyl ketone, acetylacetone, o-tolyl-t-
Butyl ketone, methyl-2,6-di-t-butyl phenyl ketone, ethyl 2-furarate, isoamyl 2-furarate, methyl 2-furarate, propyl 2-frurate and the like can be used.

As the electron donor (g) and the electron donor (f), an organosilicon compound represented by the following formula (4) can be used. As the organic silicon compound, R _n Si (OR ′) _4-n (4) (wherein R and R ′ are hydrocarbon groups, and 0 <n <4
Specific examples of the organosilicon compound represented by the general formula (4) include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, and diphenyldimethoxysilane. , Phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis o-
Tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, bisethylphenyldimethoxysilane,
Ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, Methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, n-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane , Ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxy
Examples thereof include silane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, and dimethyltetraethoxydisiloxane.

(Polymerization) Propylene used in the present invention
The α-olefin copolymer (B) comprises propylene and another α-olefin in the presence of the above Ziegler catalyst.
Finally, it can be produced by copolymerizing so as to have the above composition ratio. The polymerization can be carried out by any of liquid phase polymerization methods such as suspension polymerization and solution polymerization, or gas phase polymerization methods. In the liquid phase polymerization method, the above-mentioned inert hydrocarbon solvent can be used as the polymerization solvent, and propylene can also be used as the polymerization solvent.

During the polymerization, the solid catalyst component (d) is usually 0.001 to 1.0 mmol, preferably 0.005 to 0.005, in terms of titanium atom, per liter of the polymerization volume.
Used in an amount of 0.5 mmol. The organoaluminum compound (e) is used in an amount in the range of 5 to 1000 in terms of molar ratio per mole of Ti atoms in the solid catalyst component (d).

The electron donor (f) is an organoaluminum compound.
The molar ratio per mole of the substance (e) is preferably 0.002 to
Used in amounts in the range of 0.5. Polymerization temperature is slurry
When carrying out the polymerization, usually -50 to 100 ° C, preferably
It is preferable that the temperature is 0 to 90 ° C.
When applied, it is usually 0 to 250 ° C., preferably 20 to 2
It is preferably 00 ° C. In addition, carry out gas phase polymerization
The polymerization temperature is usually 0 to 120 ° C., preferably 2
It is preferably 0 to 100 ° C. The polymerization pressure is
Normal pressure to 9.8 MPa (100 kg / cm ²), Preferred
Ordinary pressure to 4.9 MPa (50 kg / cm²) Conditions
Below, the polymerization reaction is batch type, semi-continuous type, continuous type.
The offset method can also be used. Further polymerization
It is also possible to divide the reaction into two or more stages with different reaction conditions.
It

Polypropylene Resin Multilayer Film In the polypropylene resin multilayer film of the present invention, the above-mentioned two kinds of propylene / α-olefin copolymer (A) and propylene / α-olefin copolymer (B) are laminated side by side. It is a film. In order to manufacture such a polypropylene resin multilayer film, various known methods can be adopted. For example, propylene / α-olefin copolymer (A) and propylene / α-olefin copolymer (B) are separately melted by an extruder, extruded from a coextrusion die joined at the tip, and cooled and solidified by a cooling roll. Examples include a method of winding.

As another method for producing the polypropylene resin multilayer film of the present invention, a film of propylene / α-olefin copolymer (B) (or (A)) is previously produced by a known method, and The propylene / α-olefin copolymer (A) (or (B)) is melted, extruded from a die, and extruded on the film of the propylene / α-olefin copolymer (B) (or (A)), Examples include a method of winding after cooling and solidifying with a cooling roll.

The thickness of each layer constituting the polypropylene resin multilayer film of the present invention is not particularly limited as long as it can achieve the object of the present invention, but propylene.α-
The layer comprising the olefin copolymer (A) is preferably 1
To 100 μm, particularly preferably 5 to 50 μm, and the layer comprising the propylene / α-olefin copolymer (B) is preferably 1 to 100 μm, particularly preferably 5
˜50 μm.

The polypropylene resin multilayer film of the present invention has excellent low-temperature heat-sealing properties and hot tack properties, and therefore can be used as various films. Therefore, it can be suitably used as a sealant for a food packaging film. The propylene / α-olefin copolymers (A) and (B) used in the polypropylene resin multilayer film of the present invention include a crystal nucleating agent, a weather resistance stabilizer, and a heat resistance stabilizer as long as the object of the present invention is not impaired. If necessary, additives such as antistatic agents, antislip agents, antiblocking agents, antifog agents, lubricants, pigments, dyes, plasticizers, antiaging agents, hydrochloric acid absorbents, antioxidants, etc. are added. Good. Further, other synthetic resins can be blended in small amounts without departing from the spirit of the present invention.

The polypropylene resin multilayer film according to the present invention comprises a base material, a layer made of the propylene / α-olefin copolymer (A) as described above, and a propylene / α-olefin.
It may be formed of a layer composed of the olefin copolymer (B). Such a multilayer film can be obtained, for example, by extrusion-coating a propylene / α-olefin copolymer (B) and a propylene / α-olefin copolymer (A) on a substrate in this order.

The base material is not particularly limited as long as it has a film forming ability, and any synthetic resin or paper,
Aluminum foil, cellophane, etc. can be used. Examples of such synthetic resin include high density polyethylene, medium or low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, ionomer, polypropylene, poly-1-butene, poly-4. -Olefin polymers such as methyl-1-pentene; Vinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, polyacrylonitrile and other vinyl polymers; nylon 6, nylon 66, nylon 1
0, nylon 11, nylon 12, nylon 610, polyamides such as polymeta-xylylene adipamide; polyethylene terephthalate, polyethylene terephthalate /
Polyesters such as isophthalate and polybutylene terephthalate; polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polycarbonate and the like can be mentioned.

When the base material is a synthetic resin film (sheet), the synthetic resin film may be non-oriented or uniaxially or biaxially stretched. These base materials can be appropriately selected depending on the application and the article to be packaged. For example, when the object to be packaged is a perishable food, a resin having excellent transparency, rigidity and gas permeation resistance such as polyamide, polyvinylidene chloride, ethylene / vinyl alcohol copolymer, polyvinyl alcohol and polyester. Can be used. When the article to be packaged is a confectionery product or a textile product, it is preferable to use polypropylene or the like, which has good transparency, rigidity, and water permeation resistance.

[0073]

EXAMPLES Next, the present invention will be explained with reference to examples, but the present invention is not limited to these examples. In addition, each physical property in an Example was measured by the following method. Melting point (Tm) The temperature at the apex of the maximum peak in the chart during crystal melting when the sample was heated at a temperature rising rate of 10 ° C./min with a differential scanning calorimeter (DSC) was taken as the melting point.

Melt Flow Rate (MFR) The melt flow rate (MFR) was measured according to the method of ASTM D 1238 under the conditions of 230 ° C. and a load of 2.16 kg. Heat-sealing strength of the film Sample film is 2kg / with a Toyo Seiki heat sealer
Using a sample sealed at a pressure of cm ² for 1 second, cut the seal part with a width of 15 mm, and use an Instron tensile tester to measure 10
T-shaped peeling was performed at a speed of mm / min. From the peel strength at each temperature, find the seal temperature that reaches 6 N / 15 mm,
This was used as the heat sealing temperature.

Hot Tack Property of Film Using a heat sealer having a seal bar having a length of 300 mm and a width of 10 mm, a peel test was carried out immediately after sealing under a load of 90 g, and the peel distance at each temperature was measured.

[0076]

[Production Example 1] Propylene / ethylene random copolymer
Preparation of (A-1) 900 ml of hexane and 6 g of ethylene were charged into an autoclave having a capacity of 2 liters, which had been sufficiently purged with nitrogen, 1 mmol of triisobutylaluminum was added, the temperature was raised to 70 ° C., and propylene was supplied to complete the addition. Pressure 7kg / cm ²
G, 0.30 mmol of methylaluminoxane, rac
-Dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride was added in an amount of 0.001 mmol in terms of Zr atom, and propylene was continuously supplied to give a total pressure of 7 kg / cm ^2. Polymerization was carried out for 30 minutes while maintaining at G. After the polymerization, the mixture was degassed and the propylene / ethylene random copolymer (A-1) was recovered in a large amount of methanol and dried under reduced pressure at 110 ° C. for 12 hours.

The resulting propylene / ethylene random copolymer (A-1) had a content of repeating units derived from ethylene of 6.5 mol% and an MFR of 2.0 g / 10.
The Mw / Mn measured by gel permeation chromatography was 2.1 and the melting point was 117 ° C.

[0078]

[Production Example 2] Propylene / ethylene random copolymer
Production of (B-1) Into an autoclave having a capacity of 2 liters, which had been sufficiently purged with nitrogen, 830 ml of hexane and 100 g of ethylene were charged, and 1 mmol of triisobutylaluminum was added.
After the temperature was raised to 0 ° C, propylene was supplied to give a total pressure of 7 kg /
cm ² G, 1 mmol of triethylaluminum and 0.005 mmol of titanium catalyst supported on magnesium chloride in terms of Ti atoms were added, and propylene was continuously supplied to keep the total pressure at 7 kg / cm ² G. While 3
Polymerization was carried out for 0 minutes. After polymerization, degas and propylene-ethylene random copolymer (B-1) in a large amount of methanol
Was collected and dried under reduced pressure at 110 ° C. for 12 hours.

The yield of the obtained propylene / ethylene random copolymer (B-1) was 33.7 g. The polymerization activity was 14 kg · polymer / mmol Zr · hr. The propylene / ethylene random copolymer (B-1) has a content of structural units derived from ethylene of 8 mol%,
The MFR was 2.8 g / 10 minutes, the Mw / Mn measured by gel permeation chromatography was 4.0, and the melting point was 130 ° C.

[0080]

Example 1 The propylene / ethylene random copolymer (A-1) produced in Production Example 1 and the propylene / ethylene random copolymer (B-1) produced in Production Example 2 were each extruded from an extruder ( 40 mmφ) and melted at the tip 2
Width 3 by co-extruding from layer T die at 250 ° C
A film having a thickness of 00 mm, a layer (A-1) of 10 μm and a layer (B-1) of 20 μm was formed.

A heat-sealing test was conducted using the (A-1) layer of the film obtained by the above method as a sealing surface. The measurement results are shown in Table 1.

[0082]

[Comparative Example 1] Thickness of 30 μm consisting only of the propylene / ethylene random copolymer (A-1) produced in Production Example 1
Example 1 was repeated except that the film No. The results are shown in Table 1.

[0083]

[Comparative Example 2] Thickness of 40 μm consisting only of the propylene / ethylene random copolymer (B-1) produced in Production Example 2
Example 1 was repeated except that the film No. The results are shown in Table 1.

[0084]

[Table 1]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mikio Hashimoto             580-30 Nagaura, Sodegaura, Chiba Prefecture             Within Land Polymer F term (reference) 4F100 AK62 AK66A AK66B AL03                       BA02 BA14 GB15 JA04A                       JA04B JA06A JA06B JA07A                       JA07B JA11 JL00                 4J028 AC01A AC03A AC23A AC31A                       AC32A AC41A AC42A AC44A                       BA01B BB01B EB04 EC02                       GA06 GA07 GA19                 4J100 AA00Q AA02Q AA03P AA04Q                       AA15Q AA16Q AA17Q AA19Q                       AA21Q CA04 DA01 DA04                       DA24 FA10 FA19 JA58

Claims (3)

[Claims] 1. (A-i) Melt flow rate (ASTM
D1238, 230 ℃, load 2.16kg) is 0.1
It is in the range of 30 g / 10 minutes, and the Mw / Mn by (A-ii) gel permeation chromatography is 1.8 to 3.
5 (A-iii), the melting point (Tm) measured by a differential scanning calorimeter is in the range of 100 ℃ ~ 140 ℃ surface layer (A) consisting of a propylene-α-olefin copolymer, (B-i) Melt flow rate (ASTM D
1238, 230 ° C, load 2.16 kg) is 0.1-3
It is in the range of 0 g / 10 minutes and has a Mw / Mn of (B-ii) gel permeation chromatography of 3.6 to 6.0.
And a melting point (Tm) measured by a differential scanning calorimeter (B-iii) in the range of 120 ° C. to 145 ° C. and a layer (B) made of a propylene / α-olefin copolymer, A polypropylene resin multilayer film, wherein the layer (B) is provided adjacent to the surface layer (A). 2. A propylene / α obtained by producing the propylene / α-olefin copolymer (A) with a metallocene catalyst.
1. An olefin copolymer.
The polypropylene resin multilayer film described. 3. A propylene / α obtained by producing the propylene / α-olefin copolymer (B) with a Ziegler type catalyst.
1. An olefin copolymer.
Alternatively, the polypropylene resin multilayer film according to the item 2.