JPH05112682A - Polypropylene composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a propylene-based copolymer composition capable of producing a film excellent in low-temperature heat-sealing property and blocking resistance. [Structure] A propylene homopolymer having a molecular weight distribution (Mw / Mn) of 3 or less, an average elution temperature of 40 to 100 ° C., and an elution dispersity σ value of 10 or less, or propylene and ethylene, or α having 4 to 20 carbon atoms. A copolymer of 1 to 70% by weight of a copolymer (A) with an olefin and propylene and ethylene or an α-olefin having 4 to 20 carbon atoms in a molecular weight distribution (Mw / Mn) range of 3.5 to 10. Polymer (B) 30-
99% by weight.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to propylene random copolymer compositions. More specifically, it relates to a propylene polymer composition suitable for a heat-sealing film for a packaging film such as tobacco and caramel, and is obtained by blending a propylene polymer having a specific property and a propylene random copolymer in an appropriate ratio. It relates to a composition.

[0002]

2. Description of the Related Art Propylene homopolymers or copolymers (hereinafter sometimes collectively referred to as "propylene polymers") have been developed for use in a wide variety of fields because of their excellent properties. Is well known. For example, although it is widely used as a packaging film, since polypropylene has a relatively high melting point, propylene generally has ethylene or a carbon number of 4 to 20 in order to improve heat sealability at low temperatures in this type of application. A propylene random copolymer obtained by copolymerizing an α-olefin is used.

Such a conventionally known packaging film made of a propylene random copolymer is superior in transparency and scratch resistance as compared with a film made of low density polyethylene, but is still heat sealable at a low temperature. Is not enough. For the purpose of improving this, a copolymer in which the copolymerization amount of ethylene or an α-olefin having 4 to 20 carbon atoms is increased is known. However, although the low temperature heat-sealing property of this copolymer is improved, Further improvement is required because stickiness (blocking resistance) is deteriorated and rigidity of the film is reduced. Thus, in order to improve the heat-sealing property and the blocking resistance at low temperature, the appearance of a propylene random copolymer having a low melting point and a small amount of components causing stickiness is desired.

By the way, conventionally, an olefin polymerization catalyst comprising a titanium compound and an organoaluminum compound has been generally used for producing a propylene polymer. 58-1930
No. 9, No. 60-3500, No. 61-130314,
63-295607, JP-A-1-275609,
No. 1-301704 and No. 2-41303), a propylene random copolymer using these olefin polymerization catalysts and a method for producing the same (JP-A-62-1).
19215, JP-A-1-266116 and 2-17.
No. 3014, No. 2-173015, No. 2-24720
No. 7, each publication), the use of the obtained copolymer as a heat-sealing agent (JP-A-2-173016), and the like. According to these proposals, a propylene random copolymer having a low melting point and a small amount of components that cause stickiness is obtained, but on the other hand, since the molecular weight distribution is narrow, film formation cannot be practically performed. However, there is a problem that it cannot be used because it causes surface roughness.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems.

[0006]

SUMMARY OF THE INVENTION Means for Solving the Problems] <Summary> The present invention, propylene polymer following the (A) 1
To 70% by weight and 99 to 30% by weight of the propylene random copolymer (B). Propylene polymer (A) : A propylene polymer having the following characteristics (a) to (c). (A) a propylene homopolymer, or a propylene polymer containing less than 0.5 mol% of ethylene or an α-olefin having 4 to 20 carbon atoms; and (b) having a molecular weight distribution (Mw / Mn) of 3 or less. And (c) the average elution temperature (T ₅₀ ) is 4
It is in the range of 0 to 100 ° C and the elution dispersity (σ value) is 10
Being below. Propylene random copolymer (B) : A propylene random copolymer composed of propylene, ethylene and / or an α-olefin having 4 to 20 carbon atoms and having the following characteristics (d) to (e). (D) 90 to 99.5 mol% of structural units obtained from propylene, ethylene and /
Or, 0.5 to 10 mol% of a structural unit obtained from an α-olefin having 4 to 20 carbon atoms is present, and (e) the molecular weight distribution (Mw / Mn) is in the range of 3.5 to 10.

The above-mentioned molecular weight distribution (Mw / M
n) is gel permeation chromatography (G
The value by the measurement of PC) and the average elution temperature (T ₅₀ )
Temperature Rising Elution Fraction (hereinafter "TRE") using o-dichlorobenzene as a solvent
"F") means the value based on the elution curve of the polymer by the method. The details will be described later.

<Effect> The present invention makes it possible to provide a heat seal film having excellent low temperature heat sealability and blocking resistance.

Detailed Description of the Invention <Propylene Polymer (A)> The propylene polymer (A) of the present invention is a propylene homopolymer, or less than 0.5 mol% of ethylene or α- having 4 to 20 carbon atoms. It is a propylene polymer containing an olefin. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene,
3-methylbutene-1,1-hexene, 4-methylpentene-1,1-heptene, 1-octene, 1-nonene,
Examples include 1-decene and 1-hexadecene. The preferable ratio of the structural unit is slightly different depending on the kind of the monomer other than propylene, but in general, the propylene structural unit is 9
It is 2 to 99 mol%.

Molecular weight distribution (Mw / M) of the copolymer (A)
n) is in the range of 3 or less. The range is preferably 1 to 2.8. Generally, a polymer obtained with a catalyst composed of a metallocene compound and an alumoxane has only Mw / Mn of 3 or less, but if it exceeds 3, blocking resistance is deteriorated because the catalyst also has heterogeneity. Therefore, it is not preferable. The molecular weight of the gel permeation chromatography (GPC) copolymer was measured according to "Gel Permeation Chromatography" published by Maruzen by Takeuchi. That is, a standard polystyrene having a known molecular weight (Tosoh's monodisperse polystyrene) was used and converted into a number average molecular weight (Mn) and a weight average molecular weight (Mw) by the universal method, and the value of Mw / Mn was obtained. Measured by Waters 150C-ALC / GPC
As the column, three AD80M / S manufactured by Showa Denko KK were used. Sample is 0.2-wt% in 0-dichlorobenzene
It was diluted to 200 μl and used at 140 ° C. and a flow rate of 1 ml / min.

The average elution temperature (T ₅₀ ) by TREF is 4
It is in the range of 0 to 90 ° C., and the elution dispersity (σ value) is 10 or less. The average elution temperature (T ₅₀ ) indicates the temperature at which the integrated weight of the eluted polymer becomes 50% by weight. The elution dispersity (σ value) is calculated based on the assumption that the elution amount by TREF follows a normal probability distribution with respect to the elution temperature, and the weight-integrated elution amount I
(T) is the following formula:

[0012]

[Equation 1]

Is a σ value when it is defined as represented by
Specifically defined _{σ = T 84. 1 -T 50} . T _{84. 1} shows the temperature at which the cumulative weight becomes 84.1 wt%. still,
TREF is measured by the Journal of Applied Polymer S
cience 26, 4217-4231 (1981). The average elution temperature and elution dispersity are preferably 50 to 95 ° C. and the σ value is 9 or less. More preferably, it is 50 to 90 ° C. and the σ value is 8 or less. If the average elution temperature is less than 40 ° C, the molecular weight is too low or the melting point is too low, which causes blocking. If it exceeds 100 ° C, the molecular weight is too high for molding or the melting point is too high. It does not have heat sealability. Further, when the elution dispersity is 10 or more, the components that cause blocking increase, and therefore both the heat sealing property at low temperature and the blocking resistance cannot be satisfied.

The propylene polymer (A) can be produced with a polymerization catalyst composed of the following components (C) and (D). <Component (C)> component C, the following general _{formula: Qa (C 5 H 5-} ab R 1 b) (C 5 H 5-ac R 2 c) MeXY or the following general formula: Sa (C ₅ H _{5 -ad} R ³ _d ) A transition metal compound represented by ZMeXY. Here, Q represents a bonding group that bridges the two conjugated five-membered ring ligands, and S represents a bonding group that bridges the conjugated five-membered ring ligand and the Z group. Specifically, (i) alkylene groups such as methylene group, ethylene group, isopropylene group, phenylmethylmethylene group, diphenylmethylene group, cyclohexylene group; (b) silylene group, dimethylsilylene group, phenylmethylsilylene group, diphenylsilylene. Group, disilylene group,
A silylene group such as a tetramethyldisilylene group; (C) a hydrocarbon group containing germanium, phosphorus, nitrogen, boron or aluminum [specifically (CH ₃ ) ₂ Ge
_{Group, (C 6 H 5) 2} Ge group, (CH ₃₎ P group, (C ₆ H ₅₎ P
Group, (C ₄ H ₉ ) N group, (C ₆ H ₅ ) N group, (CH ₃ ) B
Group, (C ₄ H ₉ ) B group, (C ₆ H ₅ ) B group, (C ₆ H ₅ ) Al
Group, (CH ₃ O) Al group, etc.] and the like. Preferred are alkylene groups and silylene groups. a is 0 or 1.

In the above general formula, (C ₅ H
_5-ab R ¹ _b ), (C ₅ H _5-ac R ² _c ) and (C ₅ H _5-ad
The conjugated five-membered ring ligand represented by R ³ _d ) is defined separately, but is not limited to b, c and d, and R
It is needless to say that the three conjugated five-membered ring groups may be the same or different because the definitions themselves of ¹ , R ² and R ³ are the same (detailed later). One specific example of the conjugated five-membered ring group is a cyclopentadienyl group of b = 0 (or c = 0, d = 0) (without a substituent other than the bridging group Q or S). When this conjugated five-membered ring group is b ≠ 0 (or c ≠ 0, d ≠ 0) and has a substituent, one specific example of R ¹ (or R ² , R ³ ) is A hydrogen group (C _{1 to} C ₂₀ , preferably C _{1 to} C ₁₂ ),
This hydrocarbon group may be bonded to the cyclopentadienyl group as a monovalent group or may be bonded to a cyclopentadienyl group as a divalent group. A typical example of the latter is R
¹ (or R ² , R ³ ) share a double bond of the cyclopentadienyl group to form a condensed 6-membered ring,
That is, the conjugated 5-membered ring group is an indenyl group or a fluorenyl group. That is, typical examples of the conjugated 5-membered ring group are a substituted or unsubstituted cyclopentadienyl group, an indenyl group and a fluorenyl group.

R ¹ , R ² and R ³ are, in addition to the above-mentioned C _{1 to} C ₂₀ , preferably C _{1 to} C ₁₂ hydrocarbon groups,
Halogen groups (for example, fluorine, chlorine, bromine), alkoxy groups (for example, those of C _{1 to} C ₁₂ ), silicon-containing hydrocarbon groups (for example, silicon atom to —Si (R ¹ )).
(A group having about 1 to 24 carbon atoms in the form of (R ² ) (R ³ )),
A phosphorus-containing hydrocarbon group (for example, a phosphorus atom is -P (R))
(R) group having about 1 to 18 carbon atoms, nitrogen-containing hydrocarbon group (for example, group containing nitrogen atom in the form of -N (R) (R ') and having about 1 to 18 carbon atoms) Alternatively, a boron-containing hydrocarbon group (for example, a boron atom represented by -B (R) (R)
It is a group having about 1 to 18 carbon atoms). b (or c, d) is 2 or more and R ¹ (or R ² ,
When a plurality of R ³ ) are present, they may be the same or different. b, c and d are 0 when a is 0
It is an integer that satisfies ≦ b ≦ 5, 0 ≦ c ≦ 5, 0 ≦ d ≦ 5, and when a is 1, 0 ≦ b ≦ 4, 0 ≦ c ≦ 4, 0 ≦ d ≦ 4.

Me is a transition metal of Group IVB to VIB of the Periodic Table, preferably titanium, zirconium, and hafnium. Z is oxygen (-O-), sulfur (-S-) carbon number 1 to
20, preferably 1-10 alkoxy groups, 1-carbon
20, preferably 1-12 thioalkoxy group, 1-40 carbon atoms, preferably 1-18 silicon-containing hydrocarbon group, 1-40 carbon atoms, preferably 1-18 nitrogen-containing hydrocarbon group, carbon number 1 to 40, preferably 1 to 18 phosphorus-containing hydrocarbon groups. X and Y are each hydrogen, a halogen group, a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an amino group, and 1 carbon atom. ~ 20, preferably 1 ~
12, a phosphorus-containing hydrocarbon group (specifically, for example, a diphenylphosphine group) or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 (specifically, for example, a trimethylsilyl group). is there. X and Y may be the same or different. Of these, a halogen group and a hydrocarbon group are preferable.

Specific examples of this transition metal compound when Me is zirconium are as follows. (A) A transition metal having no conjugated bridging group and two conjugated five-membered ring ligands, such as (1) bis (cyclopentadienyl) zirconium dichloride, (2) bis (methylcyclopentadienyl) Zirconium dichloride, (3) bis (dimethylcyclopentadienyl) zirconium dichloride, (4) bis (trimethylcyclopentadienyl) zirconium dichloride, (5) bis (tetramethylcyclopentadienyl) zirconium dichloride,

(6) Bis (pentamethylcyclopentadienyl) zirconium dichloride, (7) Bis (indenyl) zirconium dichloride, (8) Bis (fluorenyl) zirconium dichloride, (9) Bis (cyclopentadienyl) zirconium monochloride Chloride monohydride, (10) bis (cyclopentadienyl) methyl zirconium monochloride,

(11) Bis (cyclopentadienyl) ethylzirconium monochloride, (12) Bis (cyclopentadienyl) phenylzirconium monochloride, (13)
Bis (cyclopentadienyl) zirconium dimethyl, (14) bis (cyclopentadienyl) zirconium diphenyl, (15) bis (cyclopentadienyl) zirconium dineopentyl,

(16) Bis (cyclopentadienyl) zirconium dihydride, (17) (Cyclopentadienyl) (indenyl) zirconium dichloride, (18)
(Cyclopentadienyl) (fluorenyl) zirconium dichloride and the like.

(B) a transition metal compound having two five-membered ring ligands bridged by an alkylene group, such as (1) methylenebis (indenyl) zirconium dichloride, (2) ethylenebis (indenyl) zirconium dichloride, (3) Ethylenebis (indenyl) zirconium monohydride monochloride, (4) ethylenebis (indenyl) methylzirconium monochloride,
(5) ethylenebis (indenyl) zirconium monomethoxymonochloride,

(6) ethylenebis (indenyl) zirconium diethoxide, (7) ethylenebis (indenyl) zirconium dimethyl, (8) ethylenebis (4,4)
5,6,7-Tetrahydroindenyl) zirconium dichloride, (9) ethylenebis (2-methylindenyl) zirconium dichloride, (10) ethylene (2,4
-Dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) zirconium dichloride,

(11) Ethylene (2-methyl-4-tert-butylcyclopentadienyl) (3'-tert-butyl-5 '
-Methylcyclopentadienyl) zirconium dichloride, (12) ethylene (2,3,5-trimethylcyclopentadienyl) (2 ', 4', 5'-trimethylcyclopentadienyl) zirconium dichloride, (13) isopropyl Ridenebis (indenyl) zirconium dichloride, (14) isopropylidenebis (2,4-dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) zirconium dichloride, (15) isopropylidenebis (2- Methyl-4-tert-butylcyclopentadienyl) (3′-tert-butyl-5-methylcyclopentadienyl) zirconium dichloride,

(16) Methylene (cyclopentadienyl)
(3,4-Dimethylcyclopentadienyl) zirconium dichloride, (17) methylene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) zirconium chloride hydride, (18) methylene (cyclopentadienyl) ( 3,4-dimethylcyclopentadienyl) zirconium dimethyl, (19) methylene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) zirconium diphenyl, (20) methylene (cyclopentadienyl) (trimethylcyclo Pentadienyl)
Zirconium dichloride,

(21) Methylene (cyclopentadienyl)
(Tetramethylcyclopentadienyl) zirconium dichloride, (22) isopropylidene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) zirconium dichloride, (23) isopropylidene (cyclopentadienyl) (2, 3,4,5-Tetramethylcyclopentadienyl) zirconium dichloride, (24) isopropylidene (cyclopentadienyl) (3-methylindenyl) zirconium dichloride, (25) isopropylidene (cyclopentadienyl) (fluorenyl) ) Zirconium dichloride,

(26) Isopropylidene (2-methylcyclopentadienyl) (fluorenyl) zirconium dichloride, (27) Isopropylidene (2,5-dimethylcyclopentadienyl) (3,4-dimethylcyclopentadienyl) Zirconium dichloride, (28) isopropylidene (2,5-dimethylcyclopentadienyl) (fluorenyl) zirconium dichloride, (29) ethylene (cyclopentadienyl) (3,5-dimethylcyclopentadienyl) zirconium dichloride, ( 30) ethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride,

(31) ethylene (2,5-dimethylcyclopentadienyl) (fluorenyl) zirconium dichloride, (32) ethylene (2,5-diethylcyclopentadienyl) (fluorenyl) zirconium dichloride,
(33) Diphenylmethylene (cyclopentadienyl)
(3,4-diethylcyclopentadienyl) zirconium dichloride, (34) diphenylmethylene (cyclopentadienyl) 3,4-diethylcyclopentadienyl)
Zirconium dichloride, (35) Cyclohexylidene (cyclopentadienyl) (fluorenyl) Zirconium dichloride, (36) Cyclohexylidene (2,5-dimethylcyclopentadienyl) (3 ', 4'-dimethyldimethylcyclopentadiene (Enyl) zirconium dichloride and the like.

(C) a transition metal compound having a silylene group-bridged five-membered ring ligand, such as (1) dimethylsilylene bis (indenyl) zirconium dichloride, (2) dimethylsilylene (4,5, 6,
7-tetrahydroindenyl) zirconium dichloride, (3) dimethylsilylene (2,4-dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) zirconium dichloride, (4) phenylmethylsilylene bis (indenyl) ) Zirconium dichloride, (5) phenylmethylsilylene bis (4,5, 6,
7-tetrahydroindenyl) zirconium dichloride,

(6) Phenylmethylsilylene (2,4-
Dimethylcyclopentadienyl) (3 ′, 5′-dimethylcyclopentadienyl) zirconium dichloride,
(7) Phenylmethylsilylene (2,3,5-trimethylcyclopentadienyl) (2,4,5-trimethylcyclopentadienyl) zirconium dichloride, (8)
Phenylmethylsilylenebis (tetramethylcyclopentadienyl) zirconium dichloride, (9) Diphenylsilylenebis (indenyl) zirconium dichloride, (10) Tetramethyldisilylenebis (indenyl)
Zirconium dichloride,

(11) Tetramethyldisilyne bis (cyclopentadienyl) zirconium dichloride, (12) Tetramethyldisilyne (3-methylcyclopentadienyl) (indenyl) zirconium dichloride, (13) Dimethylsilylene (cyclopentadiene) Dienyl) (3,4-dimethylcyclopentadienyl) zirconium dichloride, (14) dimethylsilylene (cyclopentadienyl)
(Trimethylcyclopentadienyl) zirconium dichloride, (15) dimethylsilylene (cyclopentadienyl) (tetramethylcyclopentadienyl) zirconium dichloride,

(16) Dimethylsilylene (cyclopentadienyl) (3,4-diethylcyclopentadienyl) zirconium dichloride, (17) Dimethylsilylene (cyclopentadienyl) (triethylcyclopentadienyl) zirconium dichloride, ( 18) dimethylsilylene (cyclopentadienyl) (tetraethylcyclopentadienyl) zirconium dichloride, (19) dimethylsilylene (cyclopentadienyl) (fluorenyl) zirconium dichloride, (20) dimethylsilylene (cyclopentadienyl) (2) , 7-Di-t-butyl rufluorenyl) zirconium dichloride,

(21) dimethylsilylene (cyclopentadienyl) (octahydrofluorenyl) zirconium dichloride, (22) dimethylsilylene (2-methylcyclopentadienyl-fluorenyl) zirconium dichloride, (23) dimethylsilylene (2) , 5-Dimethylcyclopentadienyl) (fluorenyl) zirconium dichloride, (24) Dimethylsilylene (2-ethylcyclopentadienyl) (fluorenyl) zirconium dichloride, (25) Dimethylsilylene (2,5-diethylcyclopentadienyl) ) (Fluorenyl) zirconium dichloride,

(26) Diethylsilylene (2-methylcyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, (27) Dimethylsilylene (2,5-dimethylcyclopentadienyl) (2,7
-Di-t-butylfluorenyl) zirconium dichloride, (28) dimethylsilylene (2-ethylcyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, (29) dimethylsilylene ( Diethyl cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride, (30) dimethylsilylene (methylcyclopentadienyl) (octahydrofluorenyl) zirconium dichloride, (31) dimethylsilylene (Dimethylcyclopentadienyl) (octahydrofluorenyl) zirconium dichloride, (3
2) Dimethylsilylene (ethylcyclopentadienyl)
(Octahydrofluorenyl) zirconium dichloride, (33) dimethylsilylene (diethylcyclopentadienyl) (octahydrofluorenyl) zirconium dichloride and the like.

(D) Transition metal compounds having a five-membered ring ligand bridged by a hydrocarbon group containing germanium, aluminum, boron, phosphorus or nitrogen, such as (1) dimethylgermanium bis (indenyl) zirconium dichloride, ( 2) Dimethyl germanium (cyclopentadienyl) (fluorenyl) zirconium dichloride, (3) Methylaluminum bis (indenyl)
Zirconium dichloride, (4) Phenylaluminum bis (indenyl) zirconium dichloride, (5) Phenylphosphinobis (indenyl) zirconium dichloride, (6) Ethylholanobis (indenyl) zirconium dichloride, (7) Phenylaminobis (indenyl) zirconium dichloride, (8) Phenylamino (cyclopentadienyl) (fluorenyl) zirconium dichloride, etc. are exemplified.

(E) Transition metal compounds having one five-membered ring ligand, such as (1) pentamethylcyclopentadienyl-bis (phenyl) aminozirconium dichloride (2) indenyl-bis (phenyl) aminozirconium dichloride (3) Pentamethylcyclopentadienyl-bis (trimethylsilyl) aminozirconium dichloride (4) Pentamethylcyclopentadienylphenoxyzirconium dichloride (5) Dimethylsilylene (tetramethylcyclopentadienyl) phenylaminozirconium dichloride (6) Dimethyl Silylene (tetrahydroindenyl) decylaminozirconium dichloride (7) Dimethylsilylene (tetrahydroindenyl)
(Bis (trimethylsilyl) amino) zirconium dichloride (8) Dimethylgermane (9) Tetramethylcyclopentadienyl (phenyl)
Amino zirconium dichloride and the like are exemplified.

(F) Further, it is also possible to use the compounds (a) to (e) in which chlorine is replaced by bromine, iodine, hydride, methyl, phenyl or the like. Further, in the present invention, as the component (C), compounds in which the central metal of the zirconium compounds exemplified in the above (a) to (e) are changed from zirconium to titanium, hafnium, niobium, molybdenum or tungsten can also be used. Among these, zirconium compounds, hafnium compounds and titanium compounds are preferable. More preferred are zirconium compounds and hafnium compounds crosslinked with alkylene groups or silylene groups.

<Component D> The component (D) is alumoxane. Alumoxane is a product obtained by reacting one type of trialkylaluminum or two or more types of trialkylaluminum with water. Specifically, methylalumoxane, ethylalumoxane, butylalumoxane, isobutylalumoxane, etc. obtained from one type of trialkylaluminum, and methylethylalumoxane, methylbutylalumoxane obtained from two types of trialkylaluminum and water. Examples include xane and methylisobutylalumoxane. It is possible to use a plurality of these alumoxanes in combination, and it is also possible to use in combination with other alkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum chloride. Further, it is also possible to use alumoxane modified by reacting two kinds of alumoxane or one kind of alumoxane with another organoaluminum compound. Of these, preferred are methylalumoxane, isobutylalumoxane, methylisobutylalumoxane, and mixtures of these alumoxane and trialkylaluminum. Particularly preferred are methylalumoxane and methylisobutylalumoxane.

These alumoxanes can be prepared under various known conditions. Specifically, the following methods can be exemplified. (A) A method in which a trialkylaluminum is directly reacted with water using a suitable organic solvent such as toluene, benzene or ether, (b) a salt hydrate having trialkylaluminum and water of crystallization, such as copper sulfate or aluminum sulfate. Method of reacting with hydrate, (c) Method of reacting trialkylaluminum with water impregnated in silica gel, etc. (d) Mixing trimethylaluminum and triisobutylaluminum, toluene,
A method of directly reacting with water using an appropriate organic solvent such as benzene or ether, (e) a hydrate of a salt having crystal water by mixing trimethylaluminum and triisobutylaluminum, for example, copper sulfate, aluminum sulfate hydrate And (f) impregnating silica gel with water, treating with triisobutylaluminum, and then additionally treating with trimethylaluminum, (to) synthesize methylalumoxane and isobutylalumoxane by known methods. A method of mixing a predetermined amount of these two components and reacting with heating.

<Catalyst formation> The catalyst used in the present invention comprises the above components (C) and (D) in the polymerization tank or outside the polymerization tank in the presence or absence of a monomer to be polymerized. It can be prepared by contacting. The amounts of the components (C) and (D) used in the present invention are arbitrary, but generally, the atomic ratio of the aluminum atom in the component (D) to the transition metal of the component (C) (Al / Me).
At 0.01-100,000, preferably 0.1-30,0
00. Any contacting method may be used, and they may be introduced separately at the time of polymerization and contacted, or those contacted in advance may be used.

The catalyst of the present invention comprises components (C) and (D).
Other than the above, it is possible to include other components as described above, but as the third component (optional component) that can be added to the components (C) and (D), for example, water, methanol, Active hydrogen-containing compounds such as ethanol and butanol; electron-donating compounds such as ethers, esters and amines; phenyl borate, dimethylmethoxyaluminum,
Examples thereof include alkoxy-containing compounds such as phenyl phosphite, tetraethoxysilane and diphenyldimethoxysilane; and organic boron compounds such as triphenylboron and tributylboron.

<Method for Producing Propylene Polymer (A)> The propylene polymer (A) using the polymerization catalyst comprising the components (C) and (D) can be produced by using propylene alone or with propylene and ethylene or carbon atoms. It is carried out by mixing and contacting with 4 to 20 α-olefin. In the case of copolymerization, the amount ratio of each monomer in the reaction system does not need to be constant over time, it is convenient to supply each monomer at a constant mixing ratio, and the mixing ratio of the monomers to be supplied is It is also possible to change it with time. Further, one of the monomers may be added in divided 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 efficiently contacted with each other. 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 a method in which each monomer is substantially gaseous without using a liquid solvent. A vapor phase method or the like can be used. Further, it is also applied to a method of carrying out continuous polymerization, batch polymerization or preliminary polymerization. In the case of slurry polymerization, a saturated aliphatic or aromatic hydrocarbon such as hexane, heptane, pentane, cyclohexane, benzene, or toluene is used alone or as a mixture as a polymerization solvent. The polymerization temperature is about −78 ° C., preferably 0 ° C. to 150 ° C., and hydrogen can be supplementarily used as a molecular weight regulator at that time. The amount of component (C) used during slurry polymerization is
A range of 0.001 to 1.0 grams component (C) / liter solvent is preferred. 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 / c.
m ² G is suitable.

Further, for the purpose of improving the activity, extinguishing the solvent-soluble by-produced polymer or preventing the melting point from lowering, it is preferable to use a catalyst obtained by previously polymerizing propylene alone prior to the copolymerization. The molecular weight of the polymer is
It can be controlled by adding hydrogen into the polymerization system.

<Propylene Random Copolymer (B)>
In the propylene random copolymer (B) of the present invention, the structural unit obtained from propylene is 90 to 99.5 mol%,
The structural unit obtained from ethylene and / or an α-olefin having 4 to 20 carbon atoms is present in an amount of 0.5 to 10 mol%. As the α-olefin having 4 to 20 carbon atoms, 1
-Butene, 1-pentene, 3-methylbutene-1,1-
Hexene, 4-methylpentene-1,1-heptene, 1
Examples include octene, 1-nonene, 1-thecene and 1-hexadecene. Although the preferable ratio of the structural unit is somewhat different depending on the kind of the monomer other than propylene, the ratio of the propylene structural unit is generally 92 to 99 mol%.

The ratio of Mw / Mn measured by gel permeation chromatography (GPC) is 3.5-10.
The range is, preferably 4-9. Mw / Mn> 1
When it is 0, the blend with the copolymer (A) is difficult to be uniformly mixed, and the transparency is deteriorated and the surface is roughened. on the other hand,
When Mw / Mn <3.5, the film moldability of the entire polymer is deteriorated and the effect of improving the moldability of the composition of the present invention cannot be obtained.

<Production of Propylene Random Copolymer (B)> The present polymer can be polymerized using a generally known Ziegler type catalyst composed of a titanium compound and organic aluminum. As a non-limiting example thereof, a catalyst comprising a TiCl ₃ composition manufactured by Marubeni Solvay and diethylaluminum chloride, or a highly active catalyst component containing titanium, magnesium and halogen as essential components and triethylaluminum, and optionally A catalyst consisting of an electron-donating compound used accordingly can be mentioned.

<Production of Propylene Polymer Composition> The composition of the present invention is obtained by blending the propylene polymer (A) and the propylene random copolymer (B). The blending ratio of the polymer (A) is 1 to 70% by weight,
Preferably 3-50% by weight, more preferably 5-50
% By weight. If it is less than 1% by weight, the effect of improving the low-temperature heat-sealing property and blocking resistance cannot be obtained, and if it is more than 70% by weight, the moldability cannot be improved and film formation is substantially impossible. In the composition of the present invention, in addition to the above-mentioned essential components, additional components may be further added within a range that does not significantly impair the effects of the present invention. As those additional components, antioxidants, neutralizing agents, ultraviolet absorbers, which are usually used for polyolefins,
Examples thereof include antifoaming agents, dispersants, antistatic agents, lubricants, molecular weight modifiers (peroxides), various auxiliaries such as other nucleating agents, rubber components and colorants.

As the method for producing the composition of the present invention, generally used Henschel mixer, super mixer, V
Blender, tumbler mixer, ribbon blender,
It is preferable to mix for a predetermined time using a mixer or kneader such as a Banbury mixer, a kneader blender, or an extruder, and pelletize the mixture with an ordinary extruder. This composition is processed into various molded articles through extrusion molding, hollow molding, film molding, injection molding, compression molding and the like. In particular, the extruded body exhibits the effects of the present invention to a great extent.

[0050]

【Example】

Experimental Example Production of Propylene Polymer (A) : [ Production of Catalyst Component (C) -1] Fully nitrogen-substituted 50
After introducing 200 ml of THF and 5 g of fluorene into a 0 ml flask and cooling to -50 ° C or lower, 67 ml of a dilute solution of methyllithium diethyl ether (1.4M) was added dropwise over 30 minutes, and then the temperature was gradually raised to room temperature. Reacted for hours. Then, after cooling to -50 ° C or lower again, 10 g of 6,6-dimethylfulvene was added dropwise over 30 minutes. After completion of the dropping, the temperature was slowly raised to room temperature and the reaction was performed for 2 days and nights. After the reaction was completed, 60 ml of H ₂ O was added to stop the reaction, the ether layer was separated, dehydrated with anhydrous MgSO ₄ , and the ether was evaporated to dryness to give 2-cyclopentadienyl 2-fluorene. Nylpropane crude crystal 17.6
g was obtained.

Next, 10 g of the above-mentioned crude crystal was added to THF100.
The mixture was diluted to ml and cooled to below -50 ° C, and 46.0 ml (0.0736 mol) of n-butyllithium was added dropwise over 10 minutes.
The mixture was returned to room temperature over 1 hour and reacted at room temperature for 2 hours.
Next, under a nitrogen stream, after evaporating the solvent and drying,
100 ml of dichloromethane was added, and the mixture was cooled to -50 ° C or lower. Next, a solution prepared by previously mixing 8.16 g of zirconium tetrachloride in 50 ml of dichloromethane at low temperature was fed all at once. After mixing, the temperature was slowly raised over 3 hours, and the reaction was carried out at room temperature for one day. After completion of the reaction, the solid matter was removed by filtration, and the filtrate was concentrated and recrystallized to give 4.6
8 g of red isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dichloride component (C) -1 was obtained.

[Production of catalyst component (C) -2] All reactions were carried out in an inert gas atmosphere. The reaction solvent used was previously dried. In a 500 ml glass reaction vessel, 5.0 g (33 mmol) of 2-methylindene
Was dissolved in 80 ml of tetrahydrofuran and, under cooling, n-
21 ml of 1.6 M hexane solution of butyllithium was slowly dropped into the reaction vessel. After stirring at room temperature for 1 hour, the mixture was cooled again, 3.1 g of 1,2-dibromone was slowly added dropwise, and after stirring at room temperature for 12 hours, 50 ml of water was added, and the organic phase was separated and dried. Further washed with heptane several times and dried to give bis- (2-methylindenyl) ethane 2.9.
g was obtained.

2.1 g (7.3 mmol) of bis- (2-methylindenyl) ethane obtained by the above method was dissolved in 70 ml of tetrahydrofuran, and 1.N of n-butyllithium was cooled.
5.2 ml of 6M hexane solution was slowly added dropwise. After stirring at room temperature for 3 hours, 1.6 g of zirconium tetrachloride (7.0 mm
ol) / tetrahydrofuran 60 ml solution was slowly added dropwise, and the mixture was stirred for 5 hours, blown with hydrogen chloride gas, and then dried. Subsequently, toluene was added to separate the soluble portion and crystallize at low temperature to obtain 0.95 g of a yellow powder. The obtained compound is ethylene bis- (2-methylindenyl).
It was confirmed by ¹ H-NMR that it was zirconium dichloride, and that both 2-methylindenyl groups were asymmetrical, that is, that they did not have a mirror image of the plane containing the zirconium atom.

[Production of catalyst component (D)] 48.2 g of trimethylaluminum in a reaction vessel and 565 m of a toluene solution.
50 g of copper sulfate pentahydrate with stirring at 0 ° C.
It was charged into the container at minute intervals. After finishing, slowly 25 ℃
To 25 ° C for 2 hours and then to 35 ° C for 2 hours.
Reacted for a day. The remaining copper sulfate solid was separated by filtration to obtain a toluene solution of alumoxane. The concentration of methylalumoxane was 27.3 mg / ml (2.7 w / v%).

Production of Propylene Polymer (A) -1 After thoroughly replacing the inside of a stirring autoclave with an internal volume of 15 liters with propylene, it was thoroughly dehydrated and deoxygenated.
-Introducing 5 liter of heptane, introducing 100 mmol of methylalumoxane as the component (D) in terms of alumo atom, and introducing 100 mmol of isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dichloride of the component (C) -1. Is introduced at 15 ℃ at 20 ℃
Polymerized for minutes. Further, propylene was introduced and polymerization was carried out at 40 ° C. for 2 hours at an autoclave internal pressure of 7 kg / cm ² G. After the reaction was completed, 500 ml of butanol was added, and the mixture was detouched at 50 ° C. for 1 hour, then pressure-fed into the steam stripping tank little by little over 30 minutes to evaporate the solvent, and then the polymer was separated and recovered, and dried to obtain 430 g of propylene. Polymer (A) -1 was obtained. As a result of GPC measurement, the number average molecular weight was 64,000, Mw / Mn = 2.21, MFR was 7.93,
As a result of DSC measurement, two peaks were obtained at 141.0 ° C and 135.7 ° C. As a result of TREF measurement, the average elution temperature was 81 ° C. and the elution dispersity was 3.5.

Production of Propylene Polymer (A) -2 All were carried out under the same conditions as in the production of propylene polymer (A) -1 above except that the polymerization temperature was 50 ° C. As a result, 490 g of a propylene polymer (A) -2 was obtained. The polymer has a number average molecular weight of 51,000, Mw / Mn = 2.10,
Two peaks were obtained at MFR = 13.5 g / 10 minutes and melting points of 134.2 ° C. and 127.0 ° C. As a result of TREF measurement, the average elution temperature (T ₅₀ ) was 63 ° C., and the elution dispersity was 4.7.

Preparation of Propylene Polymer (A) -3 After thoroughly replacing the inside of a stirring autoclave with an internal volume of 15 liters with propylene, it was thoroughly dehydrated and deoxygenated.
Introduce 5 liters of heptane, and as component (D), 100 mmol in terms of Al atom of methylalumoxane, ethylene bis-
After introducing 10.0 mmol of (2-methylindenyl) zirconium dichloride component (C) -2, propylene was introduced and polymerization was carried out at 20 ° C. for 15 minutes. When propylene was further introduced and the internal pressure of the autoclave was 7 kg / cm ² G, 4
Polymerization was carried out at 0 ° C for 2 hours. After the reaction, butanol 500
After adding 1 ml and detouching at 50 ° C. for 1 hour, the solution was pressure fed little by little to the steam stripping tank over 30 minutes to evaporate the solvent, and the polymer was separated and recovered. As a result, 860 g of propylene polymer (A)- Got 3. The number average molecular weight of this product is 23,500 Mw / Mn = 2.05 and the melting point is 135.2 ° C.
Met. As a result of TREF measurement, the average elution temperature was 87.
The degree of elution dispersion at ° C was 3.6.

Production of Propylene Random Copolymer (B)
As the copolymer (B) -1, a propylene random copolymer having an ethylene content of 2.5% by weight was used. MFR is 9.
2. The molecular weight distribution (Mw / Mn) was 6.50. The melting point was 147.7 ° C., the average elution temperature (T ₅₀ ) was 95 ° C., and the elution dispersity was 7.2.

Comparative Propylene Polymer (A) -4 A propylene polymer having an MFR of 7.6 and containing no ethylene was used. Mw / Mn = 6.2 Melting point was 169.6 ° C. Average elution temperature (T ₅₀ ) was 120 ° C. Elution dispersity was 5.1.

Example 1 As a base material layer, MFR 2.3 g / 10 min and II9
100 parts of 8% polypropylene [FL6S (trade name) manufactured by Mitsubishi Petrochemical Co., Ltd.] was mixed with 0.6 part by weight of glycerin monostearate and 0.1 part by weight of N, N'bis (2-hydroxyethyl) alkylamine. I used one. Further, as the surface layer, the above-mentioned propylene polymer (A) -1, 10
Parts by weight, and copolymer (B) -1, 90 parts by weight, 2,6-di-t-butyl-p-cresol as an antioxidant 0.10 part by weight, and calcium stearate 0.05 as a hydrochloric acid catching agent. 0.1 parts by weight silica with an average particle size of 3μ
5 parts by weight was added, and the mixture was mixed and pelletized.

These compositions were laminated under the following conditions and sequentially biaxially stretched to obtain a biaxially stretched polypropylene multilayer film. The polypropylene as the base material layer and the composition of the present invention as the surface layer are made into a three-layer structure of surface layer composition / polypropylene / surface layer composition using a three-layer die from an extruder with a diameter of 115 mm and a diameter of 35 mm, respectively. Similarly, a sheet was formed by melt coextrusion at 250 ° C. Subsequently, the film was stretched 5 times in the radial direction at 115 ° C. by utilizing the difference in roll peripheral speed. Next, the film was stretched 10 times in the transverse direction in a tenter oven at 168 ° C., heat-set at 155 ° C., and then one side of the film was subjected to corona discharge treatment to obtain a biaxially stretched multilayer film. The thickness constitution was 1 μ / 23 μ / 1 μ.

The heat-sealing temperature and blocking resistance of this film were measured under the following conditions. The results are shown in Table-1. Heat-sealing temperature : Using a heat-sealing bar of 5 mm x 200 mm, at each set temperature, the heat-sealing pressure is 1 kg /
A 20 mm wide sample is cut out from the sample sealed under the heat sealing condition of cm ² and heat sealing time of 0.5 seconds and separated at a pulling speed of 500 mm / min using a Shopper type tester to obtain a temperature of 100 g strength. The heat sealing temperature was used. Blocking resistance : Two films (corona discharge treated surfaces) are stacked so that the contact area is 10 cm ² , sandwiched between the two glass plates, and a load of 50 g / cm ² is applied under an atmosphere of 40 ° C. After being left to stand for 24 hours, the maximum load during peeling was measured with a Shopper type tester.

Examples 2 and 3 and Comparative Example 1 The blending ratios of the propylene polymer (A) -1 and the propylene ethylene random copolymer (B) -1 of Example 1 are shown in Table-1.
Evaluation was performed in the same manner as in Example 1 except that the change was made as shown in FIG.

Examples 4 and 5 and Comparative Example 2 Except that (A) -2, (A) -3, (A) -4 was used instead of the propylene polymer (A) -1 of Example 1.
All were evaluated in the same manner as in Example 1. The results are shown in Table-1.

Comparative Example 3 The same evaluation as in Example 1 was carried out except that only 100 parts by weight of propylene-ethylene random copolymer (B) -1 was used as the surface layer of Example 1. The above results are shown in Table-1.
However, since the film of Comparative Example 1 had severe surface roughness and was not put to practical use, the heat sealing temperature and blocking resistance could not be measured.

[0066]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hidefumi Uchino 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Petrochemical Co., Ltd. Yokkaichi Research Institute

Claims (1)

[Claims] 1. The following propylene polymer (A) is used in an amount of 1 to 7:
0% by weight, and propylene-based random copolymer (B)
A polypropylene composition containing 99 to 30% by weight. Propylene polymer (A) : A propylene polymer having the following characteristics (a) to (c). (A) a propylene homopolymer, or a propylene polymer containing less than 0.5 mol% of ethylene or an α-olefin having 4 to 20 carbon atoms; (b) a molecular weight distribution (Mw / Mn) of 3 or less. (C) The average elution temperature (T ₅₀ ) is in the range of 40 to 100 ° C., and the elution dispersity (σ value) is 10 or less. Propylene random copolymer (B) : A propylene random copolymer composed of propylene, ethylene and / or an α-olefin having 4 to 20 carbon atoms and having the following characteristics (d) to (e). (D) 90 to 99 structural units obtained from propylene.
5 mol%, 0.5 to 10 mol% of a structural unit obtained from ethylene and / or an α-olefin having 4 to 20 carbon atoms are present, and (e) a molecular weight distribution (Mw / Mn) is 3.5 to 10 Be in the range.