JPH10180964A - Biaxially oriented multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biaxially oriented multilayer film having high speed automatic packaging suitability, and excellent transparency, blocking resistance, low temperature heat sealability and starting properties of heat sealing. SOLUTION: A layer of resin composition containing 100 pts.wt. of propylene random copolymer having a DSC melting peak temperature of 110 to 140 deg.C, DSC melting finishing temperature-DSC melting peak temperature <=8 deg.C and orthodichlorobenzene solvent 40 deg.C extract amount of 2.0wt.% or less and 0.02 to 0.5 pts.wt. of inorganic or organic fine particles having a mean particle size of 0.5 to 5μm is laminated at least on one surface of a biaxially oriented base material layer made of resin containing crystalline propylene polymer as a main component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxially stretched multilayer film, and more particularly, to a high-speed automatic packaging suitability,
The present invention relates to a biaxially stretched multilayer film having excellent transparency, improved blocking resistance, and excellent low-temperature heat sealability and heat seal rising property.

[0002]

2. Description of the Related Art Hitherto, biaxially stretched multilayer films, for example, biaxially stretched polypropylene films having a heat-sealing layer laminated thereon, have been combined with various properties such as transparency and rigidity in foods, cigarettes and cassette tapes. Although it is widely used as a film for overlap packaging, etc., due to the recent development of a high-speed automatic packaging machine, the required quality of the film for automatic packaging suitability has been more advanced than ever. That is, the most important required performance of the film for overlap packaging is low-temperature heat sealability. As a method of imparting such a low-temperature heat-sealing property, a resin having a low-temperature heat-sealing property when producing a biaxially oriented polypropylene film, for example, a propylene / ethylene random copolymer resin or propylene / ethylene / butene-
(1) A method of laminating a random copolymer or the like has been developed, and further, by adding a second component such as polybutene-1 to this layer, the low-temperature heat sealability has been greatly improved.
In addition, as a measure for improving film packaging machine characteristics in response to the recent increase in speed of automatic packaging machines, a method of adding inorganic fine particles such as silica or calcium carbonate to the above resin (Japanese Patent Publication No. Hei 4-30347). Or a method of adding organic fine particles such as a spherical silicone resin powder (Japanese Patent Application Laid-Open No.
No. 2-233248) has been proposed, and a great improvement effect has been obtained with respect to speeding up of an automatic packaging machine.

[0003]

However, conventionally known propylene-based random copolymers still have insufficient heat-sealing properties at low temperatures and rising properties of heat-sealing. -Even if the copolymerization amount of the olefin is increased, the low-temperature heat-sealing property is improved, but problems such as stickiness (blocking property), slipperiness, and deterioration of transparency over time occur. Therefore, an object of the present invention is to provide a biaxially stretched multilayer film having high-speed automatic packaging suitability, excellent in low-temperature heat sealability without heat sticking and deterioration of transparency due to aging, and excellent heat seal rising property. It is in.

[0004]

[Means for Solving the Problems]

[Constitution of the Invention] The present inventors have conducted intensive studies in view of the above problems, and as a result, using a specific amount of inorganic or organic fine particles of a specific particle size in a specific propylene random copolymer. By doing so, the present inventors have found that the above object can be achieved, and have completed the present invention.
That is, the biaxially stretched multilayer film of the present invention is composed of a crystalline propylene-based polymer or a resin containing the same as a main component. At least one surface of the biaxially stretched base material layer has the following components A and B Characterized by being laminated with a layer composed of the resin composition of (1). Component A: following (a) ~ propylene random copolymer 100 parts by weight of having the characteristics of (c) (a) DSC by melting peak temperature (T _P) is intended to satisfy the range of the following formula (I).
110 ° C. ≦ T _P ≦ 140 ° C. (I) (b) The melting end temperature (T _E ) by DSC is given by the following formula (II).
Is satisfied. _{TE
-T P ≦ 8 ℃ ...... (II} ) (c) extracting the amount of the o-dichlorobenzene was extracted at 40 ° C. as a solvent is 2.0 wt% or less. Component B: 0.02 to 0.5 parts by weight of inorganic or organic fine particles having an average particle size of 0.5 to 5 μm

[I] Biaxially stretched multilayer film The biaxially stretched multilayer film of the present invention comprises a crystalline propylene polymer or at least one surface of a base material layer comprising the same as a main component. And a surface layer formed from a composition comprising the following components A and B.

(1) Base material layer (A) Crystalline propylene polymer (essential component) The crystalline propylene polymer used in the base material layer of the biaxially stretched multilayer film of the present invention is propylene alone. Polymer or a majority proportion of propylene and other α-olefins (ethylene, butene, hexene, 4-methylpentene, octene, etc.), unsaturated carboxylic acids or derivatives thereof (acrylic acid, maleic anhydride, etc.), aromatic Examples include random, block or graft copolymers with a group IV vinyl monomer (such as styrene). The isotactic index (II) of such a crystalline propylene-based polymer is 40% or more, especially 60% or more, particularly 8%.
Those having 0% or more are preferable. Therefore, it is most preferable to use a propylene homopolymer. In particular, from the viewpoint of the stiffness of the film, the paper dropping property of the film feeding section, and the suitability for high-speed automatic packaging, It is preferable to use those having I of 90% or more, especially 95% or more, particularly 98% or more. The melt flow rate (MFR, 230 ° C,
2.16 kg load) is 0.5 to 10 g / 10 min, especially 1
５5 g / 10 min is preferred. These crystalline propylene-based polymers may be used alone or as a mixture of a plurality of types of polymers, or may be a resin containing a crystalline propylene-based polymer as a main component.

(B) Other compounding materials (optional components) The base layer of the biaxially stretched multilayer film of the present invention contains the above-mentioned crystalline propylene-based polymer as a main component, and the other compounding materials deteriorate its properties. It may be blended in an amount not to be caused, for example, in a range of 30% by weight or less, preferably in a range of 20% by weight or less. Examples of such a blending material include ethylene polymer, butene polymer, and petroleum resin. And other thermoplastic polymers such as hydrocarbon polymers (including their hydrogenated products) such as terpene resins and styrene resins. Further, to the crystalline propylene polymer of the substrate layer, of course, additives such as stabilizers such as antioxidants and weathering agents, processing aids, coloring agents, antistatic agents, lubricants, and antiblocking agents are used. May be included. Among these additives, those containing an antistatic agent generally at a ratio of generally 0.2 to 1.5% by weight are preferable. Among the antistatic agents, preferred are fatty acid esters of glycerin, alkylamines, ethylene oxide adducts of alkylamines,
And its fatty acid esters. In the case of a film to which good antistatic performance has not been imparted, static electricity may accumulate during running of the film, resulting in poor paper dropping properties.

(C) Stretching The base material layer is biaxially stretched and oriented. Those not biaxially stretched are inferior. Also, the uniaxially stretched one is inferior in stiffness. The biaxial stretching is performed in the same manner as in a normal biaxial stretching method. Specifically, 3 in the vertical direction
８8 times and 3 to 12 times in the transverse direction.

(2) Surface Layer The surface layer used in the biaxially stretched multilayer film of the present invention is one which is laminated on one or both sides of a substrate layer formed from the above-mentioned crystalline propylene polymer. These surface layers are formed from a resin composition for a surface layer comprising the following components A and B.

[0010] (A) surface layer resin composition (a) Component A: propylene random copolymer having the following properties (essential component) DSC by melting peak temperature (T _P) is, 110 ° C. ≦ T
_P ≦ 140 ° C., preferably 115 ° C. ≦ T _P ≦ 135 ° C.,
Which satisfies the formula (I). The melting end temperature (T _E ) by DSC is T _E −T _P ≦ 8 ° C., preferably T _E
-T _P ≦ 7.8 ℃, those satisfying the formula (II).
The extraction amount at 40 ° C. using orthodichlorobenzene as a solvent is 2.0% by weight or less, preferably 1.5% by weight or less.

As the propylene random copolymer used as the component A, a scanning calorimeter (DSC, Diff
erential Scanning Calorimeter) by dissolution peak temperature T _P is required to fall within the scope of 110 - 140 ° C..
When the melting peak temperature by DSC is lower than 110 ° C., even if Component B described later is used, the suitability for high-speed automatic packaging and the stickiness of the film cannot be satisfied. Melting peak temperature T by DSC
_{When P} exceeds 140 ° C., the low-temperature heat sealability becomes poor. The melting end temperature T _E by DSC T _E -T _P ≦
8 ° C. must be satisfied. T _E -T _P rises of heat sealing becomes defective in a copolymer of more than 8 ° C.. The component A of the present invention has an extraction amount of 2.0% by weight or less when extracted at 40 ° C. using orthodichlorobenzene as a solvent. With a copolymer having an extraction amount exceeding 2% by weight, the stickiness of the film deteriorates, and improvement cannot be expected even by the addition of the component B described later.

As the propylene random copolymer used as the component A of the present invention, it is preferable to use a propylene / ethylene random copolymer or a propylene / butene-1 random copolymer. The MFR of these propylene-based random copolymer resins (230 ° C., 2.1
6 kg load) is generally 0.4 to 100 g / 10 min, preferably 0.5 to 50 g / 10 min, more preferably 1 to 10 g / 10 min.
It is 20 g / 10 min, particularly preferably 2 to 10 g / 10 min.

Production of Propylene-Based Random Copolymer (Component A) The propylene-based random copolymer component (A) used in the biaxially stretched film of the present invention comprises the following catalyst component (A):
By randomly copolymerizing propylene with a monomer copolymerizable with the propylene in the presence of the catalyst component (B) and, if necessary, a catalyst comprising the catalyst component (C), a copolymer having the above properties is obtained. Can be manufactured.

[0014] (i) a catalyst component <catalyst component _{^{(A)> Q 1 (C}} 5 H 4-a R 1 a) (C 5 H 4-b R 2 b) MeX
¹ Y ¹ [where Q ¹ is a binding group bridging two conjugated five-membered ring ligands, and is a divalent hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms. And a germylene group having a hydrocarbon group having 1 to 20 carbon atoms.
e represents zirconium or hafnium; X ¹ and Y ¹ each independently represent hydrogen, a halogen group, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and 1 carbon atom;
An alkylamide group, a trifluoromethanesulfonic acid group, a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms. R ¹ and R ² are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, an alkoxy group, a silicon-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, or a boron-containing hydrocarbon. Represents a group. In addition, two adjacent R ¹
Or two R ² may be bonded to each other to form a ring. a and b are integers satisfying 0 ≦ a ≦ 4 and 0 ≦ b ≦ 4. However, the two five-membered ring ligands having R ¹ and R ² are asymmetric with respect to the plane containing Me in terms of their relative positions via the group Q ¹ . ]

Q ¹ is, as described above, a linking group bridging the two conjugated five-membered ring ligands, and (A) has 1 to 1 carbon atoms.
20, preferably 1 to 6, divalent hydrocarbon groups, more specifically, for example, an alkylene group, a cycloalkylene group,
Unsaturated hydrocarbon groups such as arylene, (ii) 1-2 carbon atoms
A silylene group having a hydrocarbon group of 0, preferably 1 to 12, and (c) a germylene group having a hydrocarbon group of 1 to 20, preferably 1 to 12 carbon atoms. Regardless of the number of carbon atoms, the distance between the two bonds of the divalent Q ¹ group is about 4 atoms or less, particularly 3 atoms or less when Q ¹ is chain-like. ^{In the case where 1} has a cyclic group, it is preferable that the cyclic group is +2 atoms or less, particularly preferably the cyclic group alone. Therefore, in the case of alkylene, ethylene and isopropylidene (the distance between bonds is 2 atoms and 1 atom), in the case of a cycloalkylene group, cyclohexylene (the distance between bonds is only a cyclohexylene group), and in the case of alkylsilylene, And dimethylsilylene (the distance between the bonds is 1 atom) are preferred.

Me is zirconium or hafnium, preferably zirconium. X ¹ and Y
¹ may be each independently, that is, they may be the same or different; (a) hydrogen, (b) halogen (fluorine, chlorine, bromine, iodine, preferably chlorine), (c) 1 to 20 carbon atoms
A hydrocarbon group of (d) an alkoxy group having 1 to 20 carbon atoms,
(E) an alkylamide group having 1 to 20 carbon atoms, (f) a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms, or (g) 1 carbon atom
And (t) a trifluoromethanesulfonic acid group. R ¹ and R ² are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, an alkoxy group, a silicon-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, or a boron-containing hydrocarbon. Represents a group. Further, two adjacent R ¹ or two R ² may be bonded to each other to form a ring. a and b are integers satisfying 0 ≦ a ≦ 4 and 0 ≦ b ≦ 4. Non-limiting examples of the above metallocene compounds include the following.

Catalyst component (A-1) Transition metal compound having two silylene-bridged five-membered ring ligands, for example, dimethylsilylenebis (1-indenyl) zirconium dichloride, dimethylsilylenebis {1-
(4,5,6,7-tetrahydroindenyl) {zirconium dichloride, dimethylsilylenebis} 1- (2,
4-dimethylindenyl) zirconium dichloride,
Dimethylsilylene bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, dimethylsilylenebis {1- (2-methyl-4,5-benzoindenyl)} zirconium dichloride, dimethylsilylenebis [1- {2-Methyl-4- (1-naphthyl) indenyl}] zirconium dichloride, dimethylsilylenebis {1- (2-methyl-4-isopropylindenyl)}
Zirconium dichloride, dimethylsilylene bis ｛1-
(2-methyl-4,6-diisopropylindenyl)}
Zirconium dichloride, dimethylsilylene bis ｛1-
(2-methylindenyl) zirconium dichloride,
Methylphenylsilylenebis (1-indenyl) zirconium dichloride, methylphenylsilylenebis {1-
(4,5,6,7-tetrahydroindenyl) {zirconium dichloride, methylphenylsilylenebis} 1-
(2,4-dimethylindenyl) {zirconium dichloride, methylphenylsilylenebis} 1- (2-methyl-4-phenylindenyl)} zirconium dichloride, methylphenylsilylenebis {1- (2-methyl-
4,5-benzoindenyl)} zirconium dichloride, methylphenylsilylenebis [1- {2-methyl-
4- (1-naphthyl) indenyl}] zirconium dichloride, methylphenylsilylenebis {1- (2-methyl-4-isopropylindenyl)} zirconium dichloride, methylphenylsilylenebis {1- (2-methyl-4,6) -Diisopropylindenyl) {zirconium dichloride, methylphenylsilylenebis} 1- (2
-Methylindenyl) {zirconium dichloride, dimethylsilylene bis} 1- (2-methyl-4,5-benzoindenyl)} zirconium dimethyl, dimethylsilylenebis {1- (2-methyl-4,5-benzoindenyl) )}] Zirconium methyl chloride, dimethylsilylenebis {1- (2-methyl-4-phenylindenyl)} zirconium dimethyl, dimethylsilylenebis {1- (2-methyl-4-phenylindenyl)} zirconium chlorodimethylamide Dimethylsilylenebis {1- (2-methyl-4-phenyl-hydroazulenyl)} zirconium dichloride, dimethylsilylenebis {1- (2-methyl-4-phenyl-4,5,6,7,
8-pentahydroazulenyl)} zirconium dichloride, dimethylsilylenebis [1- {2-methyl-4-
(1-Naphthyl) -4-hydroazulenyl} zirconium dichloride, dimethylsilylenebis [1- {2-methyl-4- (1-naphthyl) -4,5,6,7,8-pentahydroazulenyl}] zirconium Dichloride, methylphenylsilylenebis {1- (2-methyl-4-phenyl-4,5,6,7,8-pentahydroazulenyl}] zirconium dichloride, dimethylsilylenebis {1- (2-ethyl-4, 5-benzoindenyl) {zirconium dichloride, dimethylsilylenebis} 1-
(2-ethyl-4-phenylindenyl) {zirconium dichloride, dimethylsilylenebis} 1- (2-ethyl-4-phenyl-4-hydroazulenyl)} zirconium dichloride, dimethylsilylenebis {1- (2-ethyl-4) -Phenyl-4,5,6,7,8-pentahydroazulenyl) {zirconium dichloride, dimethylsilylene} 1- (2-ethyl-4-phenylindenyl)} 1- (2,3,5-trimethyl Cyclopentadienyl) {zirconium dichloride, dimethylsilylene} 1- (2-ethyl-4-phenyl-4,5,6,7,
8-pentahydroazulenyl) {1- (2,3,5-
Trimethylcyclopentadienyl) {zirconium dichloride, dimethylsilylenebis} 1- (2-methyl-
4,4-dimethyl-sila-4,5,6,7-tetrahydroindenyl) {zirconium dichloride, dimethylsilylene bis} 1- (2-ethyl-4-phenylindenyl)} zirconium bis (trifluoromethanesulfonic acid) , Dimethylsilylenebis {1- (2-ethyl-4-)
Phenylazulenyl) {zirconium bis (trifluoromethanesulfonic acid), dimethylsilylenebis} 1-
(2-ethyl-4-phenyl-4,5,6,7,8-pentahydroazulenyl) {zirconium bis (trifluoromethanesulfonic acid), dimethylsilylenebis} 1-
(2-ethyl-4- (pentafluorophenyl) indenyl) {zirconium dichloride, dimethylsilylene bis} 1- (2-ethyl-4-phenyl-7-fluoroindenyl)} zirconium dichloride, dimethylsilylenebis {1- ( 2-ethyl-4-indolylindenyl) zirconium dichloride, dimethylsilylenebis {1- (2-dimethylborano-4-indolylindenyl)} zirconium dichloride and the like.

Catalyst component (A-2) A transition metal compound having two five-membered ring ligands bridged by an alkylene group, for example, (1) ethylene-1,2-bis (1
-Indenyl) zirconium dichloride, (2) ethylene-1,2-bis {1- (4,5,6,7-tetrahydroindenyl)} zirconium dichloride, (3) ethylene-1,2-bis {1- ( 2,4-dimethylindenyl) zirconium dichloride, (4) ethylene-1,
2-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, (5) ethylene-1,
2-bis {1- (2-methyl-4,5-benzoindenyl)} zirconium dichloride, (6) ethylene-1,
2-bis [1- {2-methyl-4- (1-naphthyl) indenyl}] zirconium dichloride.

Catalyst component (A-3) Transition metal compound having a 5-membered ring ligand bridged by a hydrocarbon residue containing germanium, aluminum, boron, phosphorus or nitrogen, for example, (1) dimethylgermylene bis (( 1-indenyl) zirconium dichloride, (2)
Dimethylgermylene bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, (3) dimethylgermylene bis {1- (2-methyl-4,5-benzoindenyl)} zirconium dichloride, ( 4) methyl aluminum bis (1-indenyl) zirconium dichloride, (5) phenylphosphinobis (1-indenyl) zirconium dichloride, (6) ethylholanobis (1-indenyl) zirconium dichloride,
(7) Phenylaminobis (1-indenyl) zirconium dichloride and the like are exemplified.

<Catalyst component (B)> As the component B,
Catalyst component (B-1): aluminum oxy compound, (B
-2): Lewis acid or catalyst component (B-3): ionic compound capable of reacting with catalyst component (A) to convert catalyst component (A) into a cation, catalyst component (B-
4): At least one compound selected from the group consisting of clay, clay minerals and ion-exchangeable layered compounds can be mentioned. Certain Lewis acids can also be regarded as "ionic compounds capable of converting the catalyst component (A) into cations by reacting with the catalyst component (A)". Therefore, a compound belonging to both the “Lewis acid” and “an ionic compound capable of converting the catalyst component (A) into a cation by reacting with the catalyst component (A)” is interpreted as belonging to either one. It shall be.

The aluminum oxy compound as the catalyst component (B-1) is specifically a compound represented by the following general formula (I), (II) or (III). ^{_{R 3 2 -Al- (O-AlR}} 3) p -OAlR 3 2 (I) - (O-AlR 3) p + 2 - (II) R 3 2 -Al- (O-BR 4) p -OAlR 3 ₂ (III) (where p is a number from 0 to 40, preferably 2 to 30, R ³ is a hydrogen or hydrocarbon residue, preferably 1 to 10 carbon atoms, particularly preferably 1 to 10 carbon atoms. 6).)

The compounds of the general formulas (I) and (II) are compounds also called alumoxanes, which are products obtained by reacting one kind of trialkylaluminum or two or more kinds of trialkylaluminum with water. is there. Specifically, (a) methylalumoxane, ethylalumoxane, propylalumoxane, butylalumoxane, isobutylalumoxane and the like obtained from one kind of trialkylaluminum and water; Examples thereof include methylethylalumoxane, methylbutylalumoxane, and methylisobutylalumoxane obtained from water. Particularly preferred among these are methylalumoxane and methylisobutylalumoxane. These alumoxanes can be used in combination of two or more in each group and between groups, and can also be used in combination with other alkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum, and dimethylaluminum chloride. It is.

These alumoxanes can be prepared under various known conditions. Specifically, the following methods can be exemplified. (I) a method in which a trialkylaluminum is directly reacted with water using an appropriate organic solvent such as toluene, benzene, or ether; (b) a salt hydrate having a trialkylaluminum and water of crystallization such as copper sulfate and aluminum sulfate; A method of reacting (a) trialkylaluminum with a compound such as the catalyst component (B), for example, water impregnated in silica gel or the like; A method of mixing and directly reacting with water in an appropriate solvent such as toluene, benzene, or ether. (Ho) Mixing trimethylaluminum and triisobutylaluminum to form a salt hydrate having water of crystallization, such as copper sulfate or aluminum sulfate Hydrate, and a method of reacting by heating. After treatment with butyl aluminum, adding treated with trimethylaluminum,
(And) a method of synthesizing methylalumoxane and isobutylalumoxane by a known method, mixing a predetermined amount of these two components and reacting by heating, (iii) benzene, toluene,
A salt having water of crystallization, such as copper sulfate pentahydrate, in an aromatic hydrocarbon solvent such as that described above, and reacting with trimethylaluminum under a temperature condition of about -40 to 40 ° C. The amount of water used in this case is usually 0.5 to 1.5 in molar ratio to trimethylaluminum. The thus obtained methylalmoquine is a linear or cyclic organoaluminum polymer.

The compound represented by the general formula (III) includes one kind of trialkylaluminum, or two or more kinds of trialkylaluminums and an alkylboronic acid represented by R ⁴ B (OH) ₂ (here, R ⁴ is carbon number 1
To 10 (preferably having 1 to 6 carbon atoms)) in a ratio of 10: 1 to 1: 1 (molar ratio). Specifically, (i) a 2: 1 reactant of trimethylaluminum and methylboronic acid, (filtrate) a 2: 1 reactant of triisobutylaluminum and methylboronic acid, and (ha) a 1: 1 reactant of trimethylaluminum, triisobutylaluminum and methylboronic acid 1: 1 reactant, (2) 2: 1 reactant of trimethylaluminum and ethylboronic acid, and (ho) 2: 1 reactant of triethylaluminum and butylboronic acid.
One reactant is exemplified. These compounds of the general formula (III) can be used in combination of two or more kinds, and can also be used in combination with other alkyl aluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum and dimethylaluminum chloride.

The ionic compound capable of converting the component (A) into a cation by reacting with the component (A) which is the catalyst component (B-3) is represented by the general formula (IV). There are things to be done. [K] ^{e +} [Z] ^e- (IV) Here, K is an ionic cation component such as a carbonium cation, a tropylium cation, an ammonium cation, an oxonium cation, a sulfonium cation, a phosphonium cation and the like. Is mentioned. In addition, cations of metals which are easily reduced by themselves, cations of organic metals, and the like can also be mentioned. Specific examples of these cations include (i) triphenylcarbonium, diphenylcarbonium, cycloheptatrienium, indenium, triethylammonium, tripropylammonium, tributylammonium, N, N-dimethylanilinium, dipropylammonium, Dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium, tri (methylphenyl) phosphonium, triphenylsulfonium, triphenyloxonium, triethyloxonium, pyrium and silver ions, gold ions, platinum ions, copper ions, palladium ions, mercury ions, Ferrocenium ion and the like.

Z in the above general formula (IV) is an ionic anion component, which is a component (generally non-coordinating) which becomes a counter anion to the converted cation species in the catalyst component (A). And, for example, an organoboron compound anion,
Examples thereof include an organic aluminum compound anion, an organic gallium compound anion, an organic phosphorus compound anion, an organic arsenic compound anion, and an organic antimony compound anion. Specifically, (i) tetraphenylboron, tetrakis (3,4,5-trifluorophenyl) boron, tetrakis (3,5-di (trifluoromethyl) phenyl) boron, teratokis (3,5-di ( (t-butyl) phenyl) boron, tetrakis (pentafluorophenyl) boron, (filter) tetraphenylaluminum, tetrakis (3,4,5-trifluorophenyl) aluminum, tetrakis (3,5-di (trifluoromethyl)
Phenyl) aluminum, tetrakis (3,5-di (t
-Butyl) phenyl) aluminum, tetrakis (pentafluorophenyl) aluminum, (a) tetraphenylgallium, tetrakis (3,4,5-trifluorophenyl) gallium, tetrakis (3,5-di (trifluoromethyl) phenyl) Gallium and tetrakis (3
5-di (t-butyl) phenyl) gallium, tetrakis (pentafluorophenyl) gallium, (2) tetraphenyl phosphorus, tetrakis (pentafluorophenyl) phosphorus, (ho) tetraphenyl arsenic, tetrakis (pentafluorophenyl) arsenic, (F) Tetraphenylantimony, tetrakis (pentafluorophenyl) antimony, (and) decaborate, undecaborate, carbadecaborate, decachlorodecaborate and the like.

As the Lewis acid as the catalyst component (B-2), in particular, the Lewis acid capable of converting the catalyst component (A) into a cation, various organic boron compounds are exemplified.
Specifically, there are triphenylboron, tris (3,5-difluorophenyl) boron, tris (3,5-di (trimethylsilyl) phenyl) boron, and tris (pentafluorophenyl) boron. These ionic compounds and Lewis acids can be used alone, can be used in combination with the aluminum oxy compound of the general formula (I), (II) or (III), and can be trimethylaluminum, triethylaluminum, triethylaluminum or triethylaluminum. It can be used in combination with other alkylaluminum compounds such as isobutylaluminum and dimethylaluminum chloride.

The clay, clay mineral or ionic layered compound used as the catalyst component (B-4) is as shown below. The clay is usually composed mainly of a clay mineral. Further, the ion-exchangeable layered compound is a compound having a crystal structure in which surfaces formed by ionic bonds and the like are stacked in parallel with a weak binding force to each other, and means a compound whose contained ions are exchangeable. Most clay minerals are ion-exchangeable layered compounds. For example, hexagonal close packing type, antimony type, C
An ionic crystalline compound having a layered crystal structure such as dCl ₂ type CdI ₂ type and the like can be exemplified. Further, these clays, clay minerals, and ion-exchange layered compounds are not limited to natural products, and may be artificially synthesized products.

Specific examples of the clay or clay mineral of the catalyst component (B-4) include kaolin, bentonite, kibushi clay, gailome clay, allophane, hissingelite, pyrophyllite, talc, plum group, montmorillonite Group, vermiculite, lyocdeite group, palygorskite, kaolinite, nacrite, dickite, halloysite and the like.

Specific examples of the ion-exchange layered compound include α-Zr (HAsO ₄ ) ₂ .H ₂ O and α-Zr (H
PO ₄ ) ₂ , α-Zr (KPO ₄ ) ₂ .3H ₂ O, α-
Ti (HPO ₄ ) ₂ , α-Ti (HAsO ₄ ) ₂ .H ₂
O, α-Sn (HPO ₄ ) ₂ .H ₂ O, γ-Zr (H
PO ₄ ) ₂ , γ-Ti (HPO ₄ ) ₂ , γ-Ti (NH
₄ PO ₄ ) Crystalline acidic salts of polyvalent metals such as ₂ · H ₂ O.

The catalyst component (B-4) is preferably subjected to a chemical treatment. Here, the chemical treatment may be any of a surface treatment for removing impurities adhering to the surface and a treatment that affects the crystal structure of the clay. Specific examples include acid treatment, alkali treatment, salt treatment, and organic substance treatment. The acid treatment removes impurities on the surface and increases the surface area by eluting cations such as Al, Fe, and Mg in the crystal structure. Alkali treatment destroys the crystal structure of the clay, resulting in a change in the structure of the clay. In salt treatment and organic matter treatment, ion complex,
By forming a molecular complex, an organic derivative, or the like, the surface area and the interlayer distance can be changed.

By utilizing the ion exchange property and replacing the exchangeable ions between the layers with another large bulky ion, it is also possible to obtain a layered material in which the layers are expanded. That is, the bulky ions play a pillar-like role to support the layered structure, and are called pillars. Introducing another substance between layers of the layered substance is called intercalation. As the guest compound to intercalate,
A cationic inorganic compound such as TiCl ₄ or ZrCl ₄ ;
i (OR) ₄ , Zr (OR) ₄ , PO (OR) ₃ , B
Metal alcoholates such as (OR) ₃ [R is alkyl, aryl, etc.], [Al ₁₃ O ₄ (OH) ₂₄ ] ⁷⁺ , [Zr
₄ (OH) _14] ^2+, _{[Fe 3} O (OCOCH 3) _6] ⁺
And the like. These compounds may be used alone or in combination of two or more. When intercalating these compounds, Si (OR) ₄ , Al (OR) ₃ , Ge
A polymer obtained by hydrolyzing a metal alcoholate such as (OR) ₄ or the like, a colloidal inorganic compound such as SiO _2, or the like can also be allowed to coexist. Examples of pillars include oxides formed by intercalating the above hydroxide ions between layers and then heating and dehydrating. The catalyst component (B-4) may be used alone or as a mixture of two or more of the above solids. Preferred as the catalyst component (B-4) is clay or clay mineral, and most preferred is montmorillonite.

Catalyst Component (C) As the organoaluminum compound used as the catalyst component (C), a general formula (AlR ⁴ _n X _3-n ) _m (where R ⁴ is an alkyl having 1 to 20 carbon atoms) X represents a group
Shows halogen, hydrogen, alkoxy group and amino group. n is an integer of 1-3 and m is an integer of 1-2. ), Which can be used alone or in combination. Specific compounds include trimethylaluminum, triethylaluminum, trinormal propyl aluminum, trinormal butyl aluminum, triisobutyl aluminum, trinormal hexyl aluminum, trinormal octyl aluminum, trinormal decyl aluminum, diethyl aluminum chloride, diethyl aluminum sesquichloride , Diethylaluminum hydride, diethylaluminum ethoxide, diethylaluminum dimethylamide, diisobutylaluminum hydride, diisobutylaluminum chloride and the like. Of these, preferred are m = 1 and n = 3 trialkylaluminums and alkylaluminum hydrides. More preferably, R ⁴ has 1 to 1 carbon atoms.
8 tolalkyl aluminum.

(Ii) Preparation of catalyst The catalyst used in the present invention is prepared by adding the above-mentioned catalyst component (A), catalyst component (B) and, if necessary, catalyst component (C) in a polymerization tank or outside the polymerization tank. The contact can be adjusted in the presence or absence of the monomer to be polymerized. As the catalyst component (B), the catalyst component (B
-1) When using the catalyst component (B-2) and the catalyst component (B-3), it is also possible to use a particulate solid as a carrier and use it as a solid catalyst. Fine-particle solids include inorganic porous oxides such as silica and alumina, and organic compounds include ethylene, propylene, 1-
Examples thereof include polymers or copolymers formed mainly from α-olefins such as butene or styrene. Further, the catalyst used in the present invention may be one obtained by preliminarily polymerizing in the presence of an olefin. As the olefin used for the prepolymerization, propylene, ethylene, 1-butene, 3-methylbutene-1, styrene, divinylbenzene and the like are used, but a mixture of these and other olefins may be used.

The amounts of the catalyst components (A), (B) and (C) used in the present invention are arbitrary,
In general, the preferred range of the amount used differs depending on what is selected as the catalyst component (B). When the catalyst component (B-1) is used as the catalyst component (B), the atomic ratio (Al / Me) of the aluminum atom in the catalyst component (B-1) to the transition metal in the catalyst component (A) is 1 to 100,000, preferably 1
0 to 10,000, more preferably 50 to 5,000
Range. As the catalyst component (B), the catalyst component (B-
1) When the catalyst component (B-2) and the catalyst component (B-3) are used, the transition metal in the catalyst component (A), the catalyst component (B-1), the catalyst component (B-2), and the catalyst Component (B-3)
0.1 to 1,000, preferably 0.5 to 1 in a molar ratio of
00, particularly preferably in the range of 1 to 50. If the catalyst component (C) is used, the amount used is preferably in the range of 10 ⁵ or less, more preferably 10 ⁴ or less, particularly preferably 10 ³ or less in terms of molar ratio to the component (A). Catalyst component (B)
When the catalyst component (B-4) is used as the catalyst component (B-4) is a clay or a clay mineral, the transition metal in the catalyst component (A) and the hydroxyl group of the clay or the clay mineral and the catalyst component ( The molar ratio of aluminum of C) is 1: 0.1
~ 100,000: 0.1 ~ 10,000,000, especially 1: 0.5 ~ 10,000: 0.5 ~
It is preferable to make contact at 1,000,000. When the catalyst component (B-4) is other than clay or clay mineral, the weight ratio of the transition metal in the component (A) to the aluminum in the catalyst component (C) is the same as that of the catalyst component (B-4). 1g
Per unit, 0.00001 to 1 (g): 0.001 to 10
It is preferable that the contact be made to be 0 (g).

Among these catalyst components (B), the clay, clay mineral or ion-exchange layered compound of the catalyst component (B-4) is preferred. The propylene-based random copolymer obtained by the catalyst using the catalyst component (B-4) as the catalyst component (B) has a narrow molecular weight distribution but a molecular weight distribution (weight average molecular weight obtained by GPC: Mw). And a number average molecular weight: Mn ratio) are wider than the propylene-based random copolymer using a catalyst using another catalyst component (B), and the moldability during film formation is good.

Random copolymerization The propylene-based random copolymerization carried out using a polymerization catalyst comprising the catalyst component (A), the catalyst component (B), and, if necessary, the catalyst component (C) comprises propylene, ethylene or carbon. It is carried out by mixing and contacting a number of 4 to 20 α-olefins. In the case of copolymerization, the quantitative ratio of each monomer in the reaction system does not need to be constant over time, and it is convenient to supply each monomer at a constant mixing ratio. It is also possible to change over time. Further, any of the monomers can be added in portions in consideration of the copolymerization reaction ratio. The polymerization mode may be any mode as long as the catalyst component and each monomer are in efficient contact. Specifically, a slurry method using an inert solvent, a slurry method using propylene as a solvent without substantially using an inert solvent, a solution polymerization method, or each monomer is substantially gaseous without using a substantially liquid solvent. Gas phase method or the like can be adopted. Also, continuous polymerization,
A method of performing batch polymerization or prepolymerization is also applied. In the case of slurry polymerization, a single or a mixture of saturated aliphatic or aromatic hydrocarbons such as hexane, heptane, pentane, cyclohexane, benzene, and toluene is used as a polymerization solvent. The polymerization temperature is from 0 ° C to 150 ° C,
At that time, hydrogen can be used as a molecular weight regulator in an auxiliary manner. The polymerization pressure is 0 to 90 kg / cm ² G, preferably 0 to 60 kg / cm ² G, particularly preferably 1 to 50 kg / cm ² G.
kg / cm ² G is appropriate.

(B) Component B: Inorganic or organic fine particles (essential component) The fine particles used as the above component B have an average particle diameter of 0.
Inorganic or organic fine particles of 5 to 5 μm, preferably 1.0 to 4.5 μm. As the inorganic fine particles,
For example, silica, zeolite, talc, kaolin and the like can be mentioned. Among them, it is preferable to use silica. Further, the shape is preferably spherical because it is excellent in the effect of improving the suitability for packaging. Examples of the organic fine particles include non-melting type polysiloxane powder, polyamide powder, acrylic resin powder, and condensation type resin powder having a triazine ring. It is preferable to use siloxane powder and crosslinked polymethyl methacrylate powder. It is also preferable to use a spherical shape similarly to the inorganic fine particles. Inorganic or organic fine particles having an average particle size less than the above range cannot improve packaging suitability. Further, in the case of inorganic or organic fine particles having an average particle size exceeding the above range, transparency is deteriorated. The blending amount of the inorganic or organic fine particles blended as the component B in the propylene random copolymer is 0.02 to 0.5 with respect to 100 parts by weight of the propylene random copolymer.
Parts by weight, preferably 0.05 to 0.4 parts by weight. If the amount is less than the above range, packaging suitability cannot be imparted. Further, when the amount exceeds the above range, the transparency of the film is deteriorated.

(C) Other compounding materials (optional components) In addition to these essential components, the surface layer of the biaxially stretched multilayer film of the present invention may further comprise: Alternatively, additional components other than the above essential components can be added for other purposes. As the additional component, for example, the low-temperature heat sealability can be further improved by adding 5 to 45 parts by weight of a crystalline butene-1 polymer to 100 parts by weight of the above component A. Examples of such a crystalline butene-1 polymer include a homopolymer of butene-1 and a copolymer of butene-1 with another α-olefin such as ethylene or propylene.

In order to improve suitability for high-speed packaging, it is preferable to add an organic lubricant such as various silicone oils and silicone gums. As a particularly preferred lubricant, 0.1 to 2 parts by weight of a polydiorganosiloxane gum having a polymerization degree n of 3,500 to 8,000 or 0.1 to 2 parts by weight of a silicone oil having a viscosity of 100 to 100,000 centistokes And the like.

Furthermore, in order to prevent the fine particles from falling off during packaging of the component B, the number average molecular weight is 800 to 20,000.
It is preferable that the acid-modified polypropylene be blended in an amount of 00, preferably 1,000 to 18,000 (hereinafter sometimes simply referred to as “acid-modified low molecular weight PP”). The acid-modified low-molecular-weight PP is obtained by chemically adding an unsaturated carboxylic acid and / or an anhydride thereof to a low-molecular-weight polypropylene having a terminal double bond, or lowering the molecular weight of ordinary acid-modified polypropylene. As a result, the compound is synthesized, and at least a part thereof is acid-modified at the terminal. The acid-modified polypropylene obtained by the acid modification generally has a softening point of 130 to 17
It indicates a temperature of 0 ° C, preferably 140 to 160 ° C, and generally has an acid value of 3 to 80 mgKOH / g, preferably 10 to 60 mgKOH / g. Preferred low molecular weight polypropylene having a terminal double bond,
It has 1 to 10, preferably 2 to 7, terminal double bonds per 1,000 carbons, and has a number average molecular weight of 800 to 20,000.
0, preferably 1,000 to 18,000. If the terminal double bond is less than the above range, desired acid modification may not be performed. If the terminal double bond exceeds the above range, the heat resistance of the acid-modified low molecular weight PP tends to decrease. . If the number average molecular weight is less than the above range, falling off of the fine particles cannot be prevented. On the other hand, when the number average molecular weight exceeds the above range, the heat sealing property and the prevention of falling off of the fine particles tend to decrease.

Specific examples of the unsaturated carboxylic acid and / or anhydride thereof used in the acid-modified low molecular weight PP include maleic anhydride, itaconic anhydride, citraconic anhydride, allylsuccinic anhydride and the like. Can be. Among these, it is particularly preferable to use maleic anhydride. The compounding amount of the acid-modified low-molecular-weight PP mixed with the propylene-based random copolymer is 0.5 to 10 parts by weight, preferably 2 to 7 parts by weight, based on 100 parts by weight of the propylene-based random copolymer. is there. If the amount is less than the above range, falling off of the fine particles cannot be prevented. Also,
If the compounding amount exceeds the above range, not only is the heat sealing property deteriorated, but also the cost is increased, such being undesirable. In addition, among the above-mentioned components B, a spherical fine particle having a large effect of improving the suitability for packaging can further exert the effect of preventing falling off.

(D) Production of Resin Composition for Surface Layer The resin composition for the surface layer constituting the surface layer of the biaxially stretched multilayer film of the present invention is obtained by mixing the above components A and B with a Henschel mixer, a V blender, After mixing with a mixer such as a ribbon blender, it is preferable to prepare by kneading with a kneader such as an extruder.

(3) Thickness of Biaxially Stretched Film The thickness of the biaxially stretched multilayer film of the present invention is determined according to its use, but is usually 5 to 100 μm, preferably 1 to 100 μm.
The range is from 0 to 60 μm. The ratio of the surface layer to the intermediate layer is usually 1 to 20%, preferably 1.5 to 10%. The thickness of the surface layer of the biaxially stretched multilayer film is generally 0.2 to 5 μm, preferably 0.3 to 3 μm. If the thickness of the surface layer exceeds the above range, the suitability for packaging tends to be poor.
If the thickness is less than the above range, uniform heat seal strength tends not to be provided.

[II] Production of Biaxially Stretched Multilayer Film (1) Lamination The above biaxially stretched multilayer film of the present invention comprises at least one of the crystalline propylene-based polymer and a base material layer comprising the same as a main component. This is a multilayer film that can be produced by laminating and stretching a surface layer formed from the resin composition for a surface layer composed of the components A and B on one surface.
As a method of laminating the resin composition for a surface layer comprising the component A and the component B on the crystalline propylene polymer of the biaxially stretched base material layer, for example, a method of laminating the crystalline propylene polymer of the base material layer A method in which the resin composition for a surface layer is melt-coextruded on one or both sides to form a sheet and then biaxially stretched is preferred because this composition can be easily, uniformly and thinly laminated. However, it is also possible to employ a method in which the unstretched or uniaxially stretched base layer sheet is melt-extruded and coated with the surface layer resin composition, and then biaxially stretched or uniaxially stretched in a direction perpendicular to the stretching direction of the base layer. it can.

(2) Extension First of the above-mentioned biaxial stretching, longitudinal stretching can be carried out by utilizing a difference in roll peripheral speed. That is, 90-
140 ° C., preferably 3 to 8 at a temperature of 105 to 135 ° C.
, Preferably 4 to 6 times, and subsequently in a transverse direction in a tenter oven 3 to 12 times, preferably 6 times.
Stretch up to 11 times. In order to prevent heat shrinkage at the time of heat sealing, it is desirable to heat set at a temperature of 120 to 170 ° C. subsequent to the transverse stretching.

(3) Other Treatments Further treatments such as corona treatment can be performed for the purpose of promoting printability and bleeding of the antistatic agent.

[III] Applications Since the biaxially stretched multilayer film of the present invention has suitability for high-speed automatic packaging, and has good transparency, low-temperature heat sealability and heat-sealing startability. It is suitable for high-speed automatic packaging and can be widely used as a packaging film for foods, cigarettes, cassette tapes and the like.

[0049]

【Example】

[I] Evaluation method (1) melting by DSC peak temperature T _P, and using the melting end temperature T _E Seiko Co. DSC, taking a sample amount 5.0 mg, was held at 200 ° C. 5 min, 10 to 40 ° C. ° C /
The melting peak temperature and the melting end temperature were measured when the crystal was crystallized at a temperature lowering speed of 10 minutes and melted at a temperature increasing speed of 10 ° C./minute. The melting end temperature was defined as the intersection of the baseline and the extrapolation line of the linear part in the latter half of the melting peak. (2) Amount extracted at 40 ° C. by the cross fractionation method Apparatus: CFC T150A type, manufactured by Mitsubishi Chemical Corporation Column: AD80M / S, 3 columns manufactured by Showa Denko Co., Ltd. Concentration: 40 mg / 10 ml Solvent: orthodichlorobenzene (3 ) Measurement conditions of GPC Ratio of weight average molecular weight to number average molecular weight by GPC (molecular weight distribution) Apparatus: GPC 150C type column manufactured by Waters Column: AD80M / S manufactured by Showa Denko KK Measurement temperature: 140 ° C Concentration: 20 mg / 10 ml Solvent: orthodichlorobenzene (4) 230 ° C., 2.16 in accordance with MFR ASTM-D-1238
It measured using the load of kg.

(5) Haze The values were measured immediately after the film was formed and after 14 days at 40 ° C. according to ASTM-D-1003. (6) Heat seal starting temperature A 20 mm wide sample from a sample sealed under a heat seal condition of a heat seal pressure of 1 kg / cm ² and a heat seal time of 0.5 second at each set temperature using a heat seal bar of 5 mm × 200 mm. Was cut off at a tensile speed of 500 mm / min using a Shopper type tester, and the temperature at which the strength reached 100 g was defined as the heat sealing start temperature. (7) Rise of heat seal
The rising property of the heat seal was evaluated based on the difference between the temperature indicating the strength of 400 grams and the heat seal start temperature.
It should be noted that the smaller the temperature difference, the faster the rise of the heat seal strength, and it can be said that the film has a good heat seal rise property. (8) Blocking resistance Two films are stacked so that the contact area is 10 cm ² , sandwiched between two glass plates, and treated with a load of 50 g / cm ² for 72 hours in an atmosphere of 40 ° C. The maximum load when peeling was measured with a shopper type testing machine. (9) High-speed automatic packaging suitability Using a packaging machine made by Tokyo Automatic Machinery, cigarettes were packed at 300 pieces / min, and the packaging suitability was evaluated.

[II] Examples and Comparative Examples <Example 1> [Synthesis of (r) -dimethylsilylenebis (2-methylbenzoylindenyl) zirconium dichloride] Organo
It was synthesized according to the method described in the literature of metallics 1994, 13, 964. [Preparation of catalyst] WITCO silica-supported MAO was placed in a glass reactor having an inner volume of 0.5 liter and equipped with a stirring blade.
(MAO ON SiO ₂ : TA0279 / HL103)
2.4 g (20.7 mmol-Al) was added, 50 ml of n-heptane was introduced, and 20.0 ml of a (r) -dimethylsilylenebis (2-methylbenzoindenyl) zirconium dichloride solution previously diluted in toluene.
(0.0637 mmol), followed by isobutylaluminum (TlBA) · n-heptane solution 4.14 m
1 (3.03 mmol) was added. Then at room temperature 2
The reaction was allowed to proceed for a period of time, and propylene was further allowed to flow to carry out prepolymerization to obtain a solid catalyst.

[Polymerization] After thoroughly replacing the inside of a 200-liter stirred autoclave with propylene, 3 g of a triethylaluminum / n-heptane solution, 45 kg of liquefied propylene and 1.2 kg of ethylene were introduced, and the internal temperature was raised to 30 ° C. Maintained. Next, 0.8 g of a solid catalyst (as an amount excluding a polymer component due to prepolymerization) was added.
Thereafter, the temperature was raised to 65 ° C. to start polymerization, and the temperature was maintained for 3 hours. Here, 100 ml of ethanol was added to stop the reaction. Residual gas was purged and the polymer was dried. As a result, 14.1 kg of a propylene / ethylene random copolymer having an MFR of 9.3 g / 10 min and an ethylene content of 3.7% by weight was obtained. When this polymer was analyzed, the melting peak temperature (T
_P ) is 118.9 ° C., the melting end temperature (T _E ) by DSC is 126.7 ° C., T _E −T _P is 7.8 ° C.,
The amount extracted at 40 ° C. using orthodichlorobenzene as a solvent was 0.7% by weight. Further, the ratio of the weight average molecular weight to the number average molecular weight by GPC was 2.30.

[Production of biaxially stretched film]
FR of 1.9 g / 10 min. A mixture comprising 100 parts by weight of a crystalline polypropylene homopolymer having an I of 98% and 0.9 parts by weight of a fatty acid ester of polyoxyethylene alkylamine was used. In the surface layer, the propylene / ethylene random copolymer 10 described above as the component A was used.
A resin composition in which 0.2 parts by weight of spherical silica having an average particle size of 1.5 μm as Component B was added to 0 parts by weight. The crystalline polypropylene mixture serving as the base material layer and the surface layer resin composition were each 0.15 mm / 1 mm from a 115 mm diameter and a 30 mm diameter extruder using a two-layer die.
And extruded to form a laminated sheet having a two-layer thickness. The laminated sheet is stretched 5 times in the longitudinal direction at a temperature of 115 ° C. using a difference in roll peripheral speed, and then horizontally stretched in a tenter oven at a temperature of 165 ° C. to form a biaxially stretched multilayer. A film was produced. The film had a thickness of 3 μm and a thickness of 20 μm.
Table 1 shows the results of the obtained films.

<Example 2> [Polymerization] <Example 1> except that the amount of the solid catalyst (excluding the amount of the polymer component obtained by the preliminary polymerization) was 1.0 g and the amount of ethylene gas introduced into the polymerization tank was 0.9 kg. The polymerization was carried out in the same manner as in the above. As a result, the MFR was 7.0 g / 10
As a result, 16.0 kg of a propylene / ethylene random copolymer having an ethylene content of 2.6% by weight was obtained. Was analyzed for the polymer, DSC by melting peak temperature (T _P) is 127.1 ° C., DSC due to melting completion temperature (T _E) is 133.6 ℃, T _E -T _P 6.5
The amount extracted at 40 ° C. using orthodichlorobenzene as a solvent at 0 ° C. was 0% by weight. Further, the ratio of the weight average molecular weight to the number average molecular weight by GPC was 2.38.

[Production of biaxially stretched film]
Using the same resin as in Example 1, 100 parts by weight of the propylene / ethylene random copolymer described above as Component A for the surface layer, and spherical spherical crosslinked polymethacrylic acid with an average particle size of 3 μm as Component B for the surface layer The same operation as in Example 1 was performed except that the amount of methyl powder was changed to 0.25 parts by weight. Table 1 shows the results.

<Example 3> [Polymerization] 1.0 g of a solid catalyst (as an amount excluding a polymer component by pre-polymerization) and 1.35 kg of liquefied 1-butene were introduced instead of ethylene gas introduced into a polymerization tank. Except for the above, polymerization was carried out in the same manner as in <Example 1>. As a result, a propylene / butene random copolymer having an MFR of 2.8 g / 10 min and a butene content of 3.7% by weight was 9.5.
kg. Analysis of this polymer showed that D
The melting peak temperature (T _P ) by SC is 138.4 ° C.
SC due to melting completion temperature (T _E) is 143.1 ℃, T _E -T _P is 4.7 ° C., extracted amount extracted at 40 ° C. The orthodichlorobenzene as a solvent was 0.2 wt%. The ratio of the weight average molecular weight to the number average molecular weight determined by GPC was 2.35.

[Production of biaxially stretched film]
Using the same resin as in Example 1, 100 parts by weight of the propylene / ethylene random copolymer described above as Component A for the surface layer, and a spherical non-melting polysiloxane having an average particle size of 4 μm as Component B for the surface layer An experiment was conducted in the same manner as in Example 1 except that the powder was changed to 0.1 part by weight. Table 1 shows the results.

<Example 4> [Synthesis of (r) -dimethylsilylenebis (2-methyl-4-phenylazulenyl) zirconium dichloride] Synthesis was carried out by the method described in JP-A-62-207232. -2.22 g of methylazulene in hexane 3
The solution was dissolved in 0 ml, and 15.6 ml (1.0 equivalent) of a solution of phenyllithium in cyclohexane-diethyl ether was added little by little at 0 ° C. After stirring this solution at room temperature for 1 hour, 30 ml of tetrahydrofuran cooled to −78 ° C.
Was added. 0.95 of dimethyldichlorosilane was added to this solution.
Then, the mixture was heated to room temperature, and further heated at 50 ° C. for 1.5 hours. Thereafter, an aqueous ammonium chloride solution was added thereto, and the mixture was separated. The organic phase was dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The obtained crude product is subjected to silica gel column chromatography (hexane / dichloromethane = 5 /
When purified in 1), dimethylbis {1- (2-methyl-4)
1.48 g of -phenyl-1,4-dihydroazulenyl) @silane were obtained.

The dimethylbis [1- (2-) obtained above was obtained.
Methyl-4-phenyl-1,4-dihydroazulenyl)] silane (768 mg) was dissolved in diethyl ether (15 ml), and normal butyllithium hexane solution (1.98 ml, 1.64 mol / L) was added dropwise at -78 ° C. The mixture was heated and stirred at room temperature for 12 hours. After evaporating the solvent under reduced pressure, the obtained solid was washed with hexane and dried under reduced pressure. Toluene / diethyl ether (40/1) 2
0 ml, and zirconium tetrachloride 325 m at -60 ° C.
g was added, the temperature was gradually raised, and the mixture was stirred at room temperature for 15 minutes. The obtained solution was concentrated under reduced pressure, and reprecipitated by adding hexane. A mixture of diastereomers of dimethylsilylenebis (2-methyl-4-phenyldihydroazulenyl) zirconium dichloride showing the following spectral data was obtained. was gotten.

Diastereomer A: ¹ H NMR (300
MHz, C ₆ D ₆ ) δ 0.51 (s, 6H, Si (CH
_{3) 2), 1.92 (s} , 6H, CH 3), 5.30
(Brd, 2H), 5.75-5.95 (m, 6H),
6.13 (s, 2H), 6.68 (d, J = 14 Hz,
2H), 7.05-7.20 (m, 2H, arom),
7.56 (d, J = 7 Hz, 4H) Diastereomer B: ¹ H NMR (300 MHz, C ₆
D ₆ ) δ 0.44 (s, 3H, Si (CH ₃ )), 0.
59 (s, 3H, Si (CH ₃ )), 1.84 (s, 6
_{H, CH 3), 5.38 (} br d, 2H), 5.75
-6.00 (m, 6H), 6.13 (s, 2H), 6.
78 (d, J = 14 Hz, 2H), 7.05-7.20
(M, 2H, arom), 7.56 (d, J = 7 Hz,
4H)

Mixture of diastereomers A and B 887 m
g was dissolved in 30 ml of methylene chloride and introduced into a pyrex glass reflector having a 100 W high-pressure mercury lamp. This solution was irradiated for 30 minutes under normal pressure while stirring (30
After that, methylene chloride was distilled off under reduced pressure. The obtained yellow solid was washed with toluene, hexane and the like and then dried to obtain 437 mg of (r) -dimethylsilylenebis (2-methyl-4-phenyldihydroazulenyl) zirconium dichloride showing the spectral data of diastereomer A. Was done.

[Preparation of catalyst] Chemical treatment of clay mineral Demineralized water in which 1.25 kg of magnesium chloride is dissolved
1 kg of commercially available montmorillonite (“Kunipia F” manufactured by Kunimine Industries) was dispersed in 3 liters, and stirred at 80 ° C. for 1 hour. After washing this solid with water, an 8% hydrochloric acid aqueous solution 7
Dispersed in 1 liter, stirred at 90 ° C. for 2 hours, and washed with demineralized water. This aqueous slurry of montmorillonite was adjusted to a solid concentration of 15%, and spray granulation was performed using a spray drier to obtain spherical particles. Thereafter, the particles were dried under reduced pressure at 200 ° C. for 2 hours.

Preparation of Catalyst Component In a glass reactor having an inner volume of 0.5 liter and equipped with a stirring blade, (r) -dimethylsilylenebis (2-methyl-4-
Phenylaznyl) zirconium dichloride 0.15m
mol and 0.3 mmol of a toluene solution of triisobutylaluminum were mixed, and 1.5 g of the chemically treated clay obtained above was added thereto, followed by stirring and mixing at room temperature for 5 minutes to obtain a toluene slurry of a solid catalyst.

[Polymerization] <Example 1> except that 1.5 g of a solid catalyst was added instead of the solid catalyst and 5 g of triisobutylaluminum was used instead of triethylaluminum.
The polymerization was carried out in the same manner as in the above. As a result, the MFR is 1
16.1 kg of a propylene / ethylene random copolymer having 3.4 g / 10 minutes and an ethylene content of 2.7% by weight was obtained. When this polymer was analyzed, the melting peak temperature (T _P ) by DSC was 129.3 ° C., the melting end temperature (T _E ) by DSC was 134.9 ° C., and T _{E was found.}
-T _P is 5.6 ° C., extracted amount extracted at 40 ° C. The orthodichlorobenzene as a solvent was 0 wt%.
The ratio between the weight average molecular weight and the number average molecular weight by GPC was 3.15.

[Production of biaxially stretched film]
MFR of 2.3 g / 10 min and I.P. 100 parts by weight of polypropylene having an I content of 95.5%, 0.6 parts by weight of glycerin monostearate, 0.1 part by weight of N, N'-bis (2-hydroxyethyl) alkylamine and a fatty acid ester of polyoxyethylene alkylamine Polypropylene mixed with 0.3 parts by weight was used. Also, in the surface layer,
100 parts by weight of the propylene / ethylene random copolymer described above as the component A and 2 μm in average particle size as the component B
A low molecular weight polypropylene having 4.2 terminal double bonds per 1,000 carbons modified with maleic anhydride in 0.2 part by weight of a spherical crosslinked polymethyl methacrylate powder having a number average molecular weight of 5,000, A resin composition containing 3 parts by weight of maleic anhydride-modified low molecular weight polypropylene having a value of 50 mgKOH / g and 0.9 part by weight of a silicone oil having a viscosity of 10,000 centistokes (hereinafter referred to as "α-layer resin") Abbreviated as "). As the surface layer on the other side, only the propylene / ethylene random copolymer resin of the α layer resin (hereinafter abbreviated as β layer resin) was used. The crystalline polypropylene mixture of the base layer and the α-layer resin and the β-layer resin were each 115 mm.
Using a three-layer die from an extruder having a diameter of 20 mm, and a diameter of 30 mm, α layer resin / base layer / β layer resin: 0.05 m
It was extruded and formed into a three-layer laminated sheet having a thickness of m / 1 mm / 0.05 mm. The laminated sheet is stretched 5 times in the longitudinal direction at a temperature of 115 ° C. using a difference in roll peripheral speed, and then horizontally stretched in a tenter oven at a temperature of 165 ° C. to form a biaxially stretched multilayer. A film was produced. The thickness configuration of this film is as follows: surface α layer / base layer / surface β layer: 0.9 μm / 20 μm / 1.1 μ
m. After performing corona discharge treatment on the surface side of the β-layer resin of the obtained biaxially stretched multilayer film, and performing cigarette packaging so that the corona discharge treatment surface is inside, without any trouble, smoothly The film could be packaged and had high-speed automatic packaging suitability.

Example 5 [Preparation of Catalyst] 1.5 g of a solid catalyst, 2.25 kg of liquefied 1-butene instead of ethylene gas introduced into a polymerization tank
Polymerization was carried out in the same manner as in <Example 4>, except that was introduced. As a result, 8.4 kg of a propylene / butene random copolymer having an MFR of 2.7 g / 10 min and a butene content of 5.1% by weight was obtained. When this polymer was analyzed, the melting peak temperature ( _TP ) by DSC was 13
4.9 ° C., melting end temperature (T _E ) by DSC is 13
Was 9.5 ℃, T _E -T _P is 4.6 ° C., extracted amount extracted at 40 ° C. The orthodichlorobenzene as a solvent was 0.3 wt%. The ratio between the weight average molecular weight and the number average molecular weight determined by GPC was 3.42.

[Production of Biaxially Stretched Film] A substrate layer similar to that used in Example 4 was used, and a propylene / butene-1 random copolymer 10 described above as component A was used for the surface layer.
Example 4 except that 0 parts by weight, 0.25 parts by weight of a spherical non-melting polysiloxane powder having an average particle diameter of 2 μm as Component B and 10 parts by weight of a butene-1 · ethylene copolymer were further added. A similar resin composition (hereinafter abbreviated as “α-layer resin”) was used. A film was formed in the same manner as in Example 4 except that only the propylene / butene-1 random copolymer resin of the α-layer resin (hereinafter abbreviated as “β-layer resin”) was used as the surface layer on the other side. I got When cigarette packaging was performed using this film, the packaging was successful without any trouble.

[0068] <Comparative Example 1> [Preparation of Catalyst] sufficiently introducing n- heptane 200 ml of dehydrated and deoxygenated nitrogen-purged flask, then MgCl ₂ 0.4 moles, Ti (O-nC ₄
0.8 mol of H ₉ ) ₄ was introduced, and reacted at 95 ° C. for 2 hours. After completion of the reaction, the temperature was lowered to 40 ° C., and then 48 ml of methyl hydrogen polysiloxane (of 20 centistokes) was introduced, followed by a reaction for 3 hours. The resulting solid component was washed with n-heptane. Next, the purified n-
50 ml of heptane was introduced, and 0.24 mol of the solid component synthesized above was introduced in terms of Mg atoms. Then, 25 ml of n-heptane was added to SiCl ₄₀ .
Four moles were mixed and introduced into the flask over 60 minutes while maintaining the temperature at 30 ° C., and reacted at 90 ° C. for 3 hours. To this, 0.016 mol of phthalic acid chloride was further mixed with 25 ml of n-heptane, and the mixture was kept at 90 ° C. for 30 minutes.
The mixture was introduced into the flask over a period of minutes, and reacted at 90 ° C. for 1 hour. After the completion of the reaction, the resultant was washed with n-heptane. Then, 0.24 mmol of SiCl ₄ was introduced thereinto,
For 3 hours. After the completion of the reaction, the resultant was sufficiently washed with n-heptane. 50 ml of sufficiently purified n-heptane was introduced into a flask sufficiently purged with nitrogen, then 5 g of the solid component obtained above was introduced, and further, (CH ₃ ) ₃
0.81 ml of CSi (CH ₃ ) (OCH ₃ ) ₂ was introduced and contacted at 30 ° C. for 2 hours. N-
Washed thoroughly with heptane. Furthermore, propylene was introduced and prepolymerization was performed to obtain a solid catalyst.

[Polymerization] Instead of the solid catalyst, 0.3 g of a solid catalyst (excluding the amount of the polymer component obtained by the preliminary polymerization) was used, and the amount of ethylene gas introduced into the polymerization tank was 1.9 k.
g, 10.6 g of triethylaluminum, and 2.
Polymerization was carried out in the same manner as in <Example 1> except that 25 mol was added. As a result, the MFR was 8.9 g / 10 minutes,
13.8 kg of a propylene / ethylene random copolymer having an ethylene content of 4.6% by weight was obtained. Was analyzed for the polymer, DSC by melting peak temperature (T _P) is 137.1 ° C., melting by DSC end temperature (T _E) is 146.4 ℃, T _E -T _P 9.3
The amount extracted at 40 ° C. using orthodichlorobenzene as a solvent was 8.4% by weight.

[Production of Biaxially Stretched Film] The same resin as in Example 1 was used for the base material layer, and 100 parts by weight of the propylene / ethylene random copolymer described above as Component A was used for the surface layer. A biaxially stretched film was produced in the same manner as in Example 1, except that the component B was changed to 0.15 parts by weight of amorphous silica having an average particle size of 2 μm. Table 1 shows the results.

[0071]

[Table 1]

[0072]

According to the present invention, suitable for high-speed automatic packaging,
Less stickiness of the film and decrease in transparency due to aging, improved blocking resistance, and low-temperature heel properties,
In particular, there is provided a biaxially stretched film having improved heat seal rising properties.

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Claims (3)

[Claims] A layer comprising a resin composition of the following components A and B is provided on at least one surface of a biaxially stretched base material layer comprising a crystalline propylene polymer or a resin containing the same as a main component. A biaxially stretched multilayer film characterized by being laminated. Component A: following (a) ~ propylene random copolymer 100 parts by weight of having the characteristics of (c) (a) melting by DSC peak temperature T _P is one that satisfies the range of the following formula (I). _{110 ℃ ≦ T P ≦ 140 ℃} ...... (I) (b) melting by DSC end temperature T _E is one that satisfies the range of the following formula (II). _{T E -T P ≦ 8 ℃ ......} (II) (c) extracting the amount extracted in 40 ° C. The o-dichlorobenzene as the solvent is 2.0 wt% or less. Component B: 0.02 to 0.5 parts by weight of inorganic or organic fine particles having an average particle size of 0.5 to 5 μm 2. The biaxially stretched multilayer film according to claim 1, wherein the propylene random copolymer is a propylene / ethylene random copolymer or a propylene / butene-1 random copolymer. 3. The method according to claim 1, wherein the inorganic or organic fine particles are selected from the group consisting of silica, a non-melting type polysiloxane powder, and a cross-linked polymethyl methacrylate powder.
Or the biaxially stretched multilayer film according to 2.