JPH05112683A - Propylene copolymer composition - Google Patents

Abstract

PURPOSE:To obtain a propylene copolymer composition which can provide film having low-temperature heat-sealing and anti-blocking properties by blending two kinds of propylene random copolymers of specific properties. CONSTITUTION:The subject propylene copolymer composition comprises (A) 1 to 70wt.% of a propylene random copolymer which is obtained by copolymerization of A1: 90 to 99.5 mole% of propylene and A2: 0.5 to 10 mole% of ethylene and/or an alpha-olefin of 4 to 20 carbon atoms using a catalyst containing a specific transition metal compound and alumoxane and has less than 3, preferably 1 to 2.8 molecular weight distribution (Mw/Mn), the average elution temperature of 40 to 90 deg.C, preferably 50 to 85 deg.C and elution dispersion degree of less than 10, preferably less than 9 and (B) 30 to 99wt.% of a propylene random copolymer which is produced by copolymerization of A1 and A2 in the presence of a Ziegler type catalyst containing a titanium compound and an organoaluminum compound and has molecular weight distribution of 3.5 to 10, preferably 4 to 9.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to propylene random copolymer compositions. More specifically, regarding a propylene random copolymer composition suitable for a heat-sealing film for a packaging film such as tobacco and caramel, two kinds of propylene-based random copolymers having specific properties are obtained by blending them at an appropriate ratio. The present invention 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 Summary of the Invention <Summary> The present invention, 30 to the propylene random copolymer (A) below the 1-70% by weight, and a propylene random copolymer (B) It is a copolymer composition containing 99% by weight. Propylene random copolymer (A) : A propylene random copolymer composed of propylene, ethylene and / or an α-olefin having 4 to 20 carbon atoms and having the following characteristics (a) to (c). (A) 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, (b) a molecular weight distribution (Mw / Mn) in the range of 3 or less, (c)
The average elution temperature (T ₅₀ ) is in the range of 40 to 90 ° C., and the elution dispersion degree 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 99.5 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> According to the present invention, it is possible to provide a film having excellent low temperature heat sealability and blocking resistance.

Detailed Description of the Invention <Propylene Random Copolymer (A)> The propylene random copolymer (A) of the present invention contains 90 to 99.5 mol% of structural units obtained from propylene, ethylene and And / or a structural unit obtained from 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-octene,
Examples include 1-nonene, 1-decene, 1-hexadecene and the like. 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%.

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 85 ° C. and the σ value is 9 or less. More preferably, it is 60 to 80 ° C. and the σ value is 6 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, and if it exceeds 90 ° 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 random copolymer (A) is
It can be produced by a polymerization catalyst comprising the following component (C) and component (D). <Component (C)> component C is represented by the following formula: is _{Q (C 5 H 4-a} R 1 a) (C 5 H 4-b R 2 b) a transition metal compound represented by Mexy. Where Q is
It is a bonding group that bridges two conjugated five-membered ring ligands. Specifically, (a) alkylene groups such as methylene group, ethylene group, isopropylene group, phenylmethylmethylene group, diphenylmethylene group, and cyclohexylene group; (b) silylene group, dimethylsilylene group, phenylmethylsilylene group, diphenylsilylene group. , A 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.

(C ₅ H _4-a R ¹ _a ) and (C ₅ H _4-b R ² _b )
Although the conjugated five-membered ring ligand represented by each is defined separately, a and b, and R ¹ and R ²
It is needless to say that the two conjugated five-membered ring groups may be the same or different since the definitions themselves are the same (detailed later). One specific example of this conjugated five-membered ring group is a =
0 (or b = 0) cyclopentadienyl group (without a substituent other than the bridging group Q). When this conjugated five-membered ring group is a ≠ 0 (or b ≠ 0) and has a substituent, one specific example of R ¹ (or R ² ) is a hydrocarbon group (C ₁ to C _{1 20} , preferably C _{1 to} C ₁₂ ) but this hydrocarbon group may be bound to the cyclopentadienyl group as a monovalent group or to a cyclopentadienyl group as a divalent group. May be. A typical example of the latter is R
¹ (or R ² ) forms a condensed 6-membered ring by sharing the double bond of the cyclopentadienyl group, 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 and R ² are each the above C ₁ to
In addition to C ₂₀ , preferably C _{1 to} C ₁₂ hydrocarbon groups, halogen groups (eg, fluorine, chlorine, bromine), alkoxy groups (eg, C _{1 to} C ₁₂ ), silicon-containing hydrocarbon groups ( for example, a silicon atom ^{-Si (R 1) (R 2} )
(A group having about 1 to 24 carbon atoms in the form of (R ³ )), a phosphorus-containing hydrocarbon group (for example, a phosphorus atom is —P (R) (R)).
Group containing about 1 to 18 carbon atoms, a nitrogen-containing hydrocarbon group (for example, a group containing about 1 to 18 carbon atoms containing a nitrogen atom in the form of -N (R) (R ')) or containing boron. It is a hydrocarbon group (for example, a group containing a boron atom in the form of -B (R) (R) and having about 1 to 18 carbon atoms). When a (or b) is 2 or more and a plurality of R ¹ (or R ² ) are present, they may be the same or different. a
And b are integers that satisfy 0 ≦ a ≦ 4 and 0 ≦ b ≦ 4.

Me is a transition metal of Group IVB to VIB of the Periodic Table, preferably titanium, zirconium, and hafnium. X and Y are each hydrogen, a halogen group, and a carbon number 1 to
20, preferably 1 to 10 hydrocarbon groups, having 1 to 1 carbon atoms
20, preferably 1 to 10 alkoxy groups, amino groups,
Phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 (specifically, for example, diphenylphosphine group) or silicon-containing hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 (specifically, Is, for example, a trimethylsilyl group). 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) transition metal compounds having a five-membered ring ligand bridged with 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) ethylene bis (indenyl) zirconium diethoxide, (7) ethylene bis (indenyl) zirconium dimethyl, (8) ethylene bis (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.

(B) Transition metal compounds 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.

(C) a transition metal compound having a five-membered ring ligand bridged by a hydrocarbon group containing germanium, aluminum, boron, phosphorus or nitrogen, for example (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.

(D) It is also possible to use the compounds of (a) to (c) 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 (D) 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 an 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; and (b) a salt hydrate containing trialkylaluminum and water of crystallization, such as copper sulfate or aluminum sulfate. A method of reacting with a hydrate, (c) a method of reacting trialkylaluminum with water impregnated in silica gel, etc., (d) a mixture of trimethylaluminum and triisobutylaluminum, and mixing with toluene, benzene, ether or the like. A method of directly reacting with water using an organic solvent,
(E) A method in which trimethylaluminum and triisobutylaluminum are mixed and heated to react with a salt hydrate having water of crystallization, for example, copper sulfate, aluminum sulfate hydrate,
(F) A method in which silica gel or the like is impregnated with water, treated with triisobutylaluminum, and then additionally treated with trimethylaluminum, and (to) methylalumoxane and isobutylalumoxane are synthesized by a known method. A method of quantitatively mixing and reacting by heating.

<Catalyst Formation> The catalyst used in the present invention comprises the above components (C) and (D) in a 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.

<Production Method of Propylene Random Copolymer (A)> The propylene random copolymer (A) is produced using a polymerization catalyst comprising components (C) and (D).
It is carried out by mixing and contacting propylene with ethylene and / or an α-olefin having 4 to 20 carbon atoms. The amount ratio of each monomer in the reaction system does not have to be constant over time, it is convenient to supply each monomer at a constant mixing ratio, and the mixing ratio of the supplied monomers can be changed over time. Is also possible. 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 substantially no inert solvent as propylene and α-olefin as a solvent, a solution polymerization method or substantially each monomer without using a liquid solvent. A gas phase method that keeps the gas in a gaseous state can be adopted. 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 -48 ° C, preferably 0 ° C to 15 ° C.
It is 0 ° C., at which time hydrogen can be used supplementarily as a molecular weight regulator. In the slurry polymerization, the amount of the component (C) used is 0.001 to 1.0 g of the component (C).
A range of / liter solvent is preferred. 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 is suitable.

For the purpose of improving the activity, extinguishing the solvent-soluble by-product polymer or preventing the melting point from falling, it is preferable to use a catalyst prepared by previously polymerizing propylene alone prior to the copolymerization. At this time, the proportion of the propylene homopolymer portion in all the copolymers is usually 10% by weight or less, preferably 5% by weight or less, and a DSC peak due to the propylene homopolymer is observed in the product polymer. It is preferable that it is not high. In this case, the polymerization temperature during propylene homopolymerization is generally the same as or lower than the temperature of the copolymerization to be carried out thereafter. Therefore, the temperature during homopolymerization of propylene is −30 to 70 ° C., preferably 0 to 50 ° C. Usually, the pressure can be from normal pressure to 20 kg / cm ² G, but it is not necessarily limited to this as long as the ratio of the propylene homopolymer part to the target copolymer is within the above-mentioned predetermined range. The molecular weight of the copolymer 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)> This polymer can be polymerized by 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 Copolymer Composition> The composition of the present invention is obtained by blending the propylene random copolymer (A) and the copolymer (B). The mixing ratio of the copolymer (A) is 1 to 70% by weight, preferably 3 to 5%.
It is 0% by weight, more preferably 5 to 40% by weight. 1
If it is less than 70% 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 improvement of moldability cannot be obtained 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, antifoaming agents, dispersants, antistatic agents, lubricants, molecular weight modifiers (peroxides), etc. which are commonly used for polyolefins are used. Examples thereof include various auxiliaries such as nucleating agents, rubber components, colorants and the like.

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.

[0045]

【Example】

Experimental Example Production of Propylene Random Copolymer (A) : [ Production of Catalyst Component (C)] Dimethylsilylbis (tetrahydroindenyl) zirconium dichloride was added to J.Orgm.
et. Chem. (342) 21-29 1988 and J. Orgmet. Chem. (369) 359.
Synthesized according to 370 1989 . Specifically, in a 300 ml flask whose atmosphere was replaced with nitrogen, 5.4 g of bis (indenyl) dimethylsilane was diluted to 150 ml of tetrahydrofuran and cooled to 50 ° C. or lower, and then n-butyllithium (1.6 M / L) was added to 23. 6 ml was added dropwise over 30 minutes. After the dropping was completed, the temperature was raised to room temperature over 1 hour, and the reaction was performed at the elevated temperature for 4 hours to synthesize a reaction solution A.

200 ml of tetrahydrofuran was introduced into a 500 ml flask purged with nitrogen, cooled to -50 ° C. or lower, and 4.38 g of zirconium tetrachloride was slowly introduced. Then, after the entire amount of the reaction solution A was introduced, the temperature was slowly raised to room temperature over 3 hours. After reacting at room temperature for 2 hours, the temperature was further raised to 60 ° C. and reacted for 2 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and the residue was dissolved in 100 ml of toluene and redistilled to obtain 3.86 g of dimethylsilylbis (indenyl) zirconium dichloride crude crystal. Then
The crude crystals were dissolved in 150 ml of dichloromethane,
Introduced into 0 ml autoclave, platinum / carbon (0.
After introducing 5 g of a catalyst (supported by 5 wt% platinum), hydrogenation reaction was carried out at a temperature of 50 ° C. for 5 hours under a hydrogen pressure of 50 kg / cm ² G.
After completion of the reaction, the catalyst was filtered off, the solvent was distilled off under reduced pressure, the residue was extracted with toluene and recrystallized to obtain 1.26 g of the desired dimethylsilylbis (tetrahydroindenyl) zirconium dichloride.

[Production of catalyst component (D)] 100 ml of dehydrated and deoxygenated toluene was introduced into a 1000 ml flask equipped with a stirrer and a reflux condenser, which were sufficiently replaced with nitrogen. Next, 0.72 g (10 mmol) of trimethylaluminum and 1.96 g (10 mmol) of triisobutylaluminum were added to 50 m of toluene in one of the two dropping funnels.
The mixture was diluted to 1 and saturated water-containing toluene was introduced into the other one, and the mixed aluminum solution and the saturated water-containing toluene were fed under the condition of 30 ° C. in equimolar amounts of Al and water over 3 hours. After completion of the feeding, the temperature was raised to 50 ° C. and the reaction was performed for 2 hours. After the reaction was completed, the solvent was distilled off under reduced pressure to obtain 1.9 g of a white solid.

[Production of Copolymer (A) -1] 5 L of sufficiently dehydrated and deoxidized n-heptane was added to a stainless steel autoclave having an internal volume of 15 L equipped with a stirring and temperature control device. C) 4.6 mg, methyl isobutyl alumoxane 30 mm in terms of aluminum atom
Propylene was fed at a rate of 360 g / hr and ethylene was fed at a rate of 7.4 g / hr for 4 hours under the polymerization conditions of 40 ° C. The pressure inside the system at the end of the feed was 3.5 kg / cm ² G. As a result of continuous polymerization for 3 hours after completion of the feed,
The pressure dropped to 1.7 kg / cm ² G. The residual gas was purged, 400 ml of butanol was added, and the mixture was detouched at 50 ° C. for 1 hour, then pressure-fed gradually to a steam stripping tank over 1 hour to evaporate the solvent, and then the polymer was separated and recovered, and dried. As a result, 1.10 kg of copolymer (A) -1 was obtained. The polymer contained 2.5% by weight of ethylene. GPC measurement result number average molecular weight is 23,
000 and Mw / Mn = 2.00. As a result of DSC measurement, the melting point was 128.6 ° C. As a result of TREF measurement, the average elution temperature was 74 ° C. and the elution dispersity was 3.5.

The average elution temperature (T ₅₀ ) of the copolymer by the TREF method was measured as follows. A sample was dissolved in o-dichlorobenzene to prepare a 0.4 wt% solution, and 2 mg of the solution was injected into a cross fractionation device (CFC-101-L manufactured by Mitsubishi Petrochemical Co., Ltd.) and the temperature was 1 ° C / After cooling from 140 ° C. to 0 ° C. at a rate of 1 minute, the sample was loaded on the TREF column. Then 0,10,20,30,4
0,45,52,55,58,61,64,67,70,73,76,79,82,85,88,91,94,
The temperature was gradually raised to 97, 100, 102, 105, 120, 140 ° C, and the polymer eluted at each temperature was extracted from the column at a rate of 1.0 cm ³ / min, and each eluate was automatically sent to the GPC column for separation and infrared detection. The eluted polymer concentration was quantified at a wavelength of 3.42μ. The peak data processing was performed using the program attached to the device. Based on the curve thus obtained, the elution temperature when the integrated weight of the eluted polymer was 50% was expressed as the average elution temperature (T ₅₀ ).

[Production of Copolymer (A) -2] Polymerization reaction was carried out under the same conditions as in the production of Copolymer (A) -1 except that the ethylene feed rate was changed to 15.0 g / hour. I went. As a result, 1,150 g of Polymer (A) -2 was obtained. The ethylene content of the copolymer was 5.7% by weight, the number average molecular weight was 22,600, the Mw / Mn was 2.15, and the melting point was 114 ° C. The average elution temperature by TREF was 58 ° C., and the elution dispersity was 8.8.

Production of Propylene Random Copolymer (B)
As the copolymer (B) -1, the ethylene content is 2.5% by weight.
The propylene ethylene random copolymer of was used. This product has an MFR of 9.2 and a molecular weight distribution (Mw / Mn) of 6.5.
It was 0. The melting point was 147.7 ° C., the average elution temperature (T ₅₀ ) was 95 ° C., and the elution dispersity was 7.2. As the copolymer (B) -2, a propylene ethylene random copolymer having an ethylene content of 4.5% by weight [F manufactured by Mitsubishi Petrochemical Co., Ltd.
X4 (trade name)] was used. The MFR was 6.2 and the molecular weight distribution (Mw / Mn) was 5.9. The melting point was 140 ° C., the average elution temperature (T ₅₀ ) was 87 ° C., and the elution dispersity was 10.5.

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, 10 parts by weight of the above copolymer (A) -1, and 90 parts by weight of the copolymer (B) -1 as a surface layer, and 2,6-di-t-butyl-p as an antioxidant. -Cresol 0.10
Parts by weight, 0.05 parts by weight of calcium stearate as a hydrochloric acid catching agent, and 0.15 parts by weight of silica having an average particle size of 3 μ were added, and the mixture was pelletized after use.

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 seal 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 to 3 and Comparative Example 1 Implementation was carried out except that the mixing ratios of the copolymer (A) -1 and the copolymer (B) -1 of Example 1 were changed as shown in Table 1. Evaluation was performed in the same manner as in Example 1. The results are shown in Table-1. In addition,
Since the film of Comparative Example 1 had severe surface roughness and was not put to practical use, the heat seal temperature and blocking resistance could not be measured.

Example 4 Evaluations were made in the same manner as in Example 1 except that the copolymer (A) -1 in Example 1 was changed to the copolymer (A) -2. The results are shown in Table-1.

Comparative Example 2 As the surface layer of Example 1, 10% of the above copolymer (B) -2 was used.
Evaluation was made in the same manner as in Example 1 except that 0 part by weight was used. The results are shown in Table-1.

[0058]

[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. A copolymer composition comprising 1 to 70% by weight of the following propylene-based random copolymer (A) and 30 to 99% by weight of the propylene-based random copolymer (B). Propylene random copolymer (A) : A propylene random copolymer composed of propylene, ethylene and / or an α-olefin having 4 to 20 carbon atoms and having the following characteristics (a) to (c). (A) 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 (b) the molecular weight distribution (Mw / Mn) is 3 or less. (C) The average elution temperature (T ₅₀ ) is in the range of 40 to 90 ° C., and the elution dispersion degree 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.