JP2000129051A - Polypropylene resin composition for film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene resin compsn. improved in heat seal strength and low-temp. heat sealability and excellent in low-temp. impact strength and clarity by decreasing the particle size of a rubber component dispersed in the resin compsn. SOLUTION: This compsn, comprises (A) 50-99 wt.% polypropylene resin and (B) 50-1 wt.% rubber component which comprises (i) 95-5 wt.% ethylene random copolymer formed from ethylene and a 4-20C α-olefin and having a density of 0.850-0.875 g/cm3 and an MFR190 of 0.1-50 g/10 min and (ii) 5-95 wt.% 1-butene random copolymer formed from 1-butene and a 4-20C α-olefin other than 1-butene and having a 1-butene content of 60-99 mol% and an MFR190 of 0.1-50 g/10 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a film, for example,
Particularly, the present invention relates to a polypropylene resin composition having excellent heat sealing strength, low-temperature sealing property, low-temperature impact resistance and transparency when used as a cast film or a film for a sealant.

[0002]

2. Description of the Related Art Polypropylene resins are excellent in rigidity and heat resistance, but have the disadvantage of low impact strength, especially low-temperature impact resistance. It is well known that a rubber component composed of an ethylene random copolymer such as an ethylene / propylene random copolymer or an ethylene / butene random copolymer is mixed with a polypropylene resin for the purpose of remedying this drawback.

However, in such a conventional polypropylene resin composition, the dispersed particle diameter of a rubber component such as an ethylene / propylene random copolymer or an ethylene / butene random copolymer in the resin composition is large. The heat seal strength does not increase, so that it is generally difficult to obtain a composition having a good balance between heat seal strength and low-temperature impact resistance, and there are problems such as poor transparency.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by reducing the dispersed particles of a rubber component in a resin composition, thereby improving the heat sealing strength and improving the heat resistance. An object of the present invention is to provide a polypropylene resin composition having excellent low-temperature impact resistance and transparency.

[0005]

The present invention comprises (A) 50 to 99% by weight of a polypropylene resin and (B) 1 to 50% by weight of a rubber component.
(I) Density 0.850-0.875 g / cm ³ , MF
R ₁₉₀ 0.1 to 50 g / 10 min, an ethylene random copolymer selected from a random copolymer of ethylene and α-olefin having 4 to 20 carbon atoms, and (ii) 1-butene content of 60 to 99 mol. %, MFR ₁₉₀ 0.1-50
g / 10 min of 1-butene and a 1-butene random copolymer selected from random copolymers of α-olefins having 2 to 20 carbon atoms excluding 1-butene in a weight ratio of 9
A polypropylene resin composition, a resin composition for a film, and a film, comprising a random copolymer composition in the range of 5: 5 to 5:95.

The polypropylene resin (A) used in the present invention may be a homopolymer of propylene or a random or block copolymer of propylene with another α-olefin such as ethylene or 1-butene (usually Propylene unit content of 90 mol% or more), and boiling n
-Heptane insoluble content of 90% or more, preferably 93% or more can be used.

As such a polypropylene resin (A), there is typically used a catalyst formed from a solid titanium catalyst component and an organometallic compound component, or a catalyst formed from both components and an electron donor. Can be manufactured. As the solid titanium catalyst component, titanium trichloride or a titanium trichloride composition produced by various methods, or magnesium, a halogen, an electron donor, preferably an aromatic carboxylic acid ester or an alkyl group-containing ether and titanium are essential components. And the specific surface area is preferably 100
It is a titanium catalyst component with a carrier of not less than m ² / g. In particular, those produced using the latter catalyst component with a carrier are preferred.

As the organometallic compound, an organoaluminum compound is preferable, for example, trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, alkylaluminum dihalide and the like. These are suitable depending on the type of titanium catalyst component. Is also different. As electron donors, nitrogen,
Organic compounds containing phosphorus, sulfur, oxygen, silicon, boron and the like, and preferred examples thereof include esters and ethers.

A method for producing polypropylene using a catalyst component with a carrier is described in, for example, Japanese Patent Application Laid-Open No. 50-108385.
No., No. 50-126590, No. 51-20297,
Nos. 51-28189, 52-151691, and the like.

The ethylene random copolymer (i) constituting the rubber component (B) is composed of ethylene and C 4 -C 2.
0 is a random copolymer rubber with α-olefin, which is mainly composed of ethylene. The ethylene-based random copolymer (i) has a density of 0.850 to 0.5.
875 g / cm ³ , preferably 0.850 to 0.870
g / cm ³ , particularly preferably 0.855 to 0.868 g
/ Cm ³ , MFR ₁₉₀ (Melt index: ASTM
D 1238, 65T, 190 ° C, and so on.)
0.1 to 50 g / 10 min, preferably 0.5 to 20
g / 10 min, crystallinity 40% or less, preferably 20
% Or less, an ethylene / α-olefin random copolymer having 4 to 20, preferably 4 to 10, and more preferably 4 to 8 carbon atoms of the α-olefin can be used. These ethylene-based random copolymers (i) may be used alone or in combination.
A mixture of more than one species can be used.

When the density of the ethylene-based random copolymer (i) is in the range of 0.850 to 0.875 g / cm ³ , the effect of improving the handleability and low-temperature impact resistance of the resin due to blocking or the like is reduced. large. When the MFR ₁₉₀ is within the above range, the dispersibility in polypropylene is good.
When the crystallinity is less than 40%, the effect as an impact modifier is great. When the carbon number of the α-olefin is 20 or less, the rubbery properties of the polymer are increased, and the effect as an impact modifier is excellent.

The 1-butene random copolymer (ii) constituting the rubber component (B) is a random copolymer of 1-butene and an α-olefin having 2 to 20 carbon atoms excluding 1-butene. A rubber mainly composed of 1-butene. The 1-butene random copolymer (ii) has a 1-butene content of 60 to 99 mol%, preferably 7
0 to 99 mol%, MFR ₁₉₀ 0.1 to 50 g / 10 mi
n, preferably 0.5 to 20 g / 10 min, 1-butene · α- having 2 to 20, preferably 2 to 10, and more preferably 2 to 6 carbon atoms of the α-olefin except 1-butene.
An olefin random copolymer can be used. These one
-The butene random copolymer (ii) can be used alone or as a mixture of two or more.

The ethylene-based random copolymer (i) can be produced by randomly polymerizing a plurality of monomers using a known catalyst system comprising a soluble vanadium catalyst and an alkylaluminum halide compound, or a metallocene catalyst system. .

The soluble vanadium compound used as the polymerization catalyst includes, for example, vanadium tetrachloride, vanadium oxytrichloride, vanadium triacetylacetonate, oxyvanadium triacetylacetonate and the like. Examples of the alkylaluminum halide compound constituting the polymerization catalyst in combination with the soluble vanadium compound include, for example, ethylaluminum dichloride, diethylaluminum monochloride, ethylaluminum sesquichloride, diethylaluminum monobromide, diisobutylaluminum monochloride, isobutylaluminum dichloride, isobutyl Aluminum sesquichloride and the like can be mentioned.

The polymerization using a soluble vanadium catalyst comprises
The reaction can be carried out in the form of a solution or suspension or in the intermediate region, and in any case, it is preferable to use an inert solvent as the reaction medium. As the solvent used for the polymerization, a carbon number of 3 to
About 12 aliphatic hydrocarbons, for example, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, kerosene or halogenated hydrocarbons such as methyl chloride, ethyl chloride, ethylene dichloride, etc. Can be used alone or as a mixture. The polymerization temperature is usually 0 to
100 ° C.

As the metallocene catalyst, the following formula (1)
(A) a bridge type transition metal compound (hereinafter sometimes simply referred to as a transition metal compound), and (a) a compound capable of activating the transition metal compound, and (b) an organoaluminum compound , (C) an organic aluminum oxy compound, and (d) an ionized ionic compound that forms an ion pair by reacting with the (a) transition metal compound. Metallocene-based catalysts containing the above compounds are preferred.

Embedded image

In the above formula (1), M is the periodic table Nos. IV to VIB
Group transition metals, specifically, titanium, zirconium, hafnium, vanadium, niobium, tantalum,
Chromium, molybdenum, and tungsten are preferable, and titanium, zirconium, and hafnium are preferable, and zirconium is particularly preferable.

In the above formula (1), R 1, R 2, R 3 and R 4 may be the same or different from each other, and may be a hydrogen atom, a halogen atom or a hydrocarbon having 1 to 20 carbon atoms which may be substituted by halogen. Group, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group, and a part of adjacent groups is bonded to form a ring together with the carbon atom to which the group is bonded. You may.
It is to be noted that two R1 to R4 in the formula each indicate that, when they are bonded to each other to form a ring, they are preferably bonded to each other by a combination of the same symbols. It shows that it is preferable to combine them to form a ring.

In the above formula (1), X 1 and X 2 may be the same or different from each other, and may be a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms which may be substituted by halogen, Or a sulfur-containing group. As these atoms or groups, specifically, R1 to R4
And the same atoms and groups as those shown in the above.

In the above formula (1), Y is a divalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted by halogen;
Divalent silicon-containing group, divalent germanium-containing group, -O
-, -CO-, -S-, -SO-, -SO2-, -NR5
-, -P (R5)-, -P (O) (R5)-, -BR5- or -AlR5-. Here, R5 is a hydrogen atom, a halogen atom as described above, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted by halogen.

Specific examples of the bridge type transition metal compound (a) represented by the above formula (1) are described below. Bis (cyclopentadienyl) zirconium dichloride, bis (indenyl) zirconium dichloride, bis (fluorenyl) zirconium dichloride, bis (n-propylcyclopentadienyl) zirconium dichloride, bis (t-butylcyclopentadienyl) zirconium dichloride,
Bis (trimethylsilylcyclopentadienyl) zirconium dichloride, bis (neopentylcyclopentadienyl) zirconium dichloride, rac-dimethylsilylene-bis (1-cyclopentadienyl) zirconium dichloride, rac-dimethylsilylene-bis ｛1- ( 3-methylcyclopentadienyl) zirconium dichloride, rac-
Dimethylsilylene-bis {1- (2,4-dimethylcyclopentadienyl)} zirconium dichloride, rac-dimethylsilylene-bis {1- (2,3,5-trimethylcyclopentadienyl)} zirconium dichloride and the like.

Further, there may be mentioned transition metal compounds in which zirconium of the above transition metal compounds is replaced by titanium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten.

The polymerization using the metallocene catalyst can be carried out by any of liquid phase polymerization such as suspension polymerization and solution polymerization or gas phase polymerization. In the liquid phase polymerization method, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons,
Inert hydrocarbon solvents such as halogenated hydrocarbons, petroleum fractions and mixtures thereof, or α-
An olefin solvent or the like can be used. The polymerization can be performed by any of a batch system, a semi-continuous system, and a continuous system. Further, the polymerization can be performed in two or more stages having different reaction conditions. The molecular weight of the obtained copolymer can be adjusted by allowing hydrogen to exist in the polymerization system or by changing the polymerization temperature and the polymerization pressure.

1-butene random copolymer (ii)
Can be produced by randomly polymerizing a plurality of monomers by the same operation using the same catalyst as in the case of the polypropylene resin (A).

The rubber component (B) of the present invention has a weight ratio of the ethylene random copolymer (i): 1-butene random copolymer (ii) of 95: 5 to 5:95, preferably 80. : 20 to 20:80, which is a random copolymer composition.

The polypropylene resin composition of the present invention contains 50 to 99% by weight, preferably 70 to 95% by weight of the polypropylene resin (A) and the rubber component (B) 1 to 50% by weight.
%, Preferably 5 to 30% by weight.

The polypropylene resin composition of the present invention comprises:
Other resin components such as a polyethylene resin can be blended within a range that does not impair the purpose of the present invention, and an antioxidant,
Various additives such as an ultraviolet absorber, a lubricant, a nucleating agent, an antistatic agent, a flame retardant, a pigment, a dye, and an inorganic or organic filler can be blended.

The polypropylene resin composition of the present invention can be prepared by any known method, for example, a method of mixing with a mixer such as a V-type blender, a ribbon blender, a Henschel mixer, and / or an extruder. Kneading methods using a kneading machine such as a mixing roll, a Banbury mixer, or a kneader can be used in combination or alone. There are no particular restrictions on the order in which the components are mixed, but the ethylene-based random copolymer (i) and 1
-Butene-based random copolymer (ii) is first mixed,
A method of mixing the polypropylene resin (A) later or a method of mixing the three components at a time can be adopted.

Since the 1-butene random copolymer is present as the rubber component in the polypropylene resin composition thus obtained, the dispersibility of the ethylene random copolymer in the polypropylene resin is good, and the dispersion particle size is small. And a molded product such as a film having improved heat seal strength and excellent low-temperature impact resistance and transparency can be obtained.

The polypropylene resin composition of the present invention is suitable for films, sheets and the like which are required to have heat sealability, low-temperature impact resistance and transparency, such as packaging films, but can be used as other molded products.

[0031]

As described above, since the polypropylene resin composition of the present invention contains a rubber component composed of an ethylene random copolymer and a 1-butene random copolymer, the low-temperature heat sealability and the seal strength are improved. Can be
And it has excellent low-temperature impact resistance and transparency. In particular, since it is excellent in terms of film impact and heat sealing start temperature, it is suitably used as a film, particularly as a cast film.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The excellent effects of the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 The density was 0.860 g / cm ³ ,
MFR ₁₉₀ 3.6 g / 10 min ethylene / 1-butene random copolymer (EBR) 70 parts by weight, and 1-
Butene content 95 mol%, MFR ₁₉₀ 4.0 g / 10 m
In, 30 parts by weight of 1-butene-ethylene random copolymer (BER) having a Tm of 104 ° C. was mixed with a Henschel mixer and pelletized using a 40 mφ extruder. 20 parts by weight of this pelletized EBR / BER mixture, 3.5 mol% ethylene content, MFR ₂₃₀ = 6.5 g / 10 mi
n, 80 parts by weight of a propylene / ethylene random copolymer having a Tm of 141 ° C. were mixed with a Henschel mixer and formed into a film to form a film having a thickness of 50 μm.

Next, the film impact, haze, and gloss at 0 ° C. of the obtained film were measured.
And heat seal properties were measured. Here, the film impact was measured using a pendulum type film impact measuring device. As for the heat sealing property, the film was heat-sealed at a pressure of 0.2 MPa for 1 second,
The properties of the heat sealing start temperature (HS starting temperature) and the heat sealing strength at 150 ° C. (HS strength) at which a strength of 5 N / 15 mm occurs when T peeling at mm / min were measured. Table 1 shows the results.

Examples 2 to 4 and Comparative Examples 1 to 4 Films were formed in the same manner as in Example 1 according to the compositions shown in Table 1, and measurements were made. Table 1 shows the results.

[0036]

[Table 1]

Claims (3)

[Claims] 1. A composition comprising (A) 50 to 99% by weight of a polypropylene resin and (B) 1 to 50% by weight of a rubber component,
The rubber component (B) contains (i) a density of 0.850 to 0.8.
75 g / cm ³ , MFR ₁₉₀ 0.1-50 g / 10 min
An ethylene random copolymer selected from random copolymers of ethylene and α-olefin having 4 to 20 carbon atoms, and (ii) 1-butene content of 60 to 99 mol%, MF
R ₁₉₀ 0.1 to 50 g / 10 min 1-butene and 1-
A random copolymer containing a 1-butene-based random copolymer selected from random copolymers with α-olefin having 2 to 20 carbon atoms excluding butene in a weight ratio of 95: 5 to 5:95. A polypropylene resin composition comprising the composition. 2. A composition comprising (A) 50 to 99% by weight of a polypropylene resin and (B) 1 to 50% by weight of a rubber component.
The rubber component (B) contains (i) a density of 0.850 to 0.8.
75 g / cm ³ , MFR ₁₉₀ 0.1-50 g / 10 min
An ethylene random copolymer selected from random copolymers of ethylene and α-olefin having 4 to 20 carbon atoms, and (ii) 1-butene content of 60 to 99 mol%, MF
R ₁₉₀ 0.1 to 50 g / 10 min 1-butene and 1-
A random copolymer containing a 1-butene-based random copolymer selected from random copolymers with α-olefin having 2 to 20 carbon atoms excluding butene in a weight ratio of 95: 5 to 5:95. A polypropylene resin composition for a film, comprising the composition. 3. A method comprising: (A) 50 to 99% by weight of a polypropylene resin; and (B) 1 to 50% by weight of a rubber component.
The rubber component (B) contains (i) a density of 0.850 to 0.8.
75 g / cm ³ , MFR ₁₉₀ 0.1-50 g / 10 min
An ethylene random copolymer selected from random copolymers of ethylene and α-olefin having 4 to 20 carbon atoms, and (ii) 1-butene content of 60 to 99 mol%, MF
R ₁₉₀ 0.1 to 50 g / 10 min 1-butene and 1-
A random copolymer containing a 1-butene-based random copolymer selected from random copolymers with α-olefin having 2 to 20 carbon atoms excluding butene in a weight ratio of 95: 5 to 5:95. A film comprising a composition.