JP3120926B2 - Polypropylene composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene composition having excellent rigidity and heat resistance and excellent impact resistance, especially low-temperature impact resistance and toughness.

[0002]

BACKGROUND OF THE INVENTION Crystalline polypropylene is rigid,
Although excellent in heat resistance, surface glossiness, etc., there is a problem that it is inferior in impact resistance.

For this reason, various methods for improving the impact resistance of polypropylene have been conventionally proposed. For example, a method in which a modifier such as polyethylene or a rubber-like substance is mixed with crystalline polypropylene is known. As such a rubber-like substance, amorphous or low-crystalline ethylene / propylene random copolymer (EPR), polyisobutylene, polybutadiene and the like are generally used.

[0004] The present inventors have studied a polypropylene composition containing a rubber-like substance, particularly an amorphous or low-crystalline ethylene-propylene random copolymer (EPR), as an impact modifier, In order to obtain a composition having excellent impact resistance, instead of a generally known type of polymer alloy, an ethylene / propylene random copolymer (rubber component) is used as a matrix, and polypropylene (crystal component) is used as a dispersed phase. It has been found that it is necessary to form a molecular composite alloy (polypropylene composition). However, even if an attempt is made to form such a molecular composite alloy, in the case of a conventionally known polypropylene and an ethylene / propylene random copolymer, a part of the amorphous component in the polypropylene is mixed with the rubber component, and the rubber component is mixed. The components are restricted by the amorphous components of the polypropylene, and the effect of improving the impact resistance is hardly exhibited. For this reason, in order to improve the impact resistance of the polypropylene composition, it is necessary to include a large amount of a rubber-like substance such as an ethylene-propylene random copolymer in the polypropylene composition. Although the impact resistance is improved, the resulting polypropylene composition has a problem that the rigidity, heat resistance and surface hardness are greatly reduced.

For this reason, a polypropylene composition containing an inorganic filler such as talc for imparting rigidity together with the rubbery substance as described above has been proposed (JP-A-60-58459, JP-A-60-58459). JP-A-60-60154, JP-A-61-233048, JP-A-61-3
6348, JP-A-62-235350, JP-A-63-122751, JP-A-63-1503
No. 43, JP-A-1-149845, JP-A-1-149845
-204947, JP-A-1-271450, etc.).

[0006] However, the polypropylene composition containing a large amount of rubber-like substance has a problem that the improvement of rigidity by blending the inorganic filler is limited and cannot be used for applications requiring high rigidity. .

In place of such an amorphous or low-crystalline ethylene / propylene random copolymer, another ethylene / α-olefin copolymer is blended with polypropylene to obtain a polypropylene composition having excellent impact resistance. Attempts have been made to get it. For example, Japanese Patent Publication No. 58-2569
No. 3, JP-B-58-38459 discloses a composition containing crystalline polypropylene and an ethylene / 1-butene copolymer having a constitutional unit derived from 1-butene of 15 mol% or less. And JP-A-61-243.
No. 842 discloses a polypropylene composition containing crystalline polypropylene and an ethylene / 1-butene copolymer obtained using a titanium heterogeneous catalyst. The polypropylene compositions disclosed in these publications have improved impact resistance and rigidity, but further improvement in impact resistance and toughness at low temperatures is desired.

In Japanese Patent Publication No. 63-42929,
A polypropylene composition comprising a crystalline polypropylene and an ethylene / 1-butene copolymer having a structural unit derived from 1-butene of 25 to 10% by weight and an intrinsic viscosity [η] of 1.5 dl / g or less. However, this polypropylene composition has insufficient impact resistance.

Further, in JP-A-3-250040, the structural unit derived from 1-butene is 10-90.
Ethylene / 1-butene block copolymer is used as an impact modifier for polypropylene, but the ethylene / 1-butene block copolymer is inferior in compatibility with polypropylene. The improvement effect is insufficient.

[0010] For this reason, there is a demand for the appearance of a polypropylene composition having excellent rigidity and heat resistance and excellent impact resistance, particularly, low-temperature impact resistance and toughness.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polypropylene composition which is excellent in rigidity and heat resistance and also excellent in impact resistance, particularly in low temperature impact resistance and toughness.

[0012]

The polypropylene composition according to the present invention has the following properties: (A) (1) a melt flow rate (MFR: 230 ° C., 2.16 kg load) measured according to ASTM D1238 of 10 to 60 g / 10; min and (2) ambient temperature n- decane soluble component in an amount of 3 to 13 wt%, (3) polypropylene component, MFR is 20 to 80 g / 10 min, ¹³
The pentad isotacticity (I ₅ ) determined by the C-NMR method is 0.97 or more;
-The decane soluble component has an intrinsic viscosity [η] of 4 to 12 dl / g.
Wherein the structural unit derived from ethylene is 30 to 60.
Propylene block copolymer 6 contained in an amount of mol%
(B) (1) 15 to 2 structural units derived from 1-butene;
5 mol%, (2) decalin intrinsic viscosity [η] is 1.8 to 3.5 dl / g, and (3) glass transition temperature (T
g) is −55 ° C. or less, or the melting point measured as a main peak by the DSC method is 90 ° C. or less,
(4) The crystallinity measured by the X-ray diffraction method is less than 20%, and (5) the randomness parameter (B value) determined by the ¹³ C-NMR method is 1.0 to 1.4. Ethylene / 1-butene random copolymer 10 to 25% by weight
And (C) 5 to 15% by weight of an inorganic filler; (i) a melt flow rate (MFR) of 8 g / 10 min or more;
i) Crosshead speed 2 according to ASTM D790
The flexural modulus (FM) measured under the condition of mm / min is 20
000 kg / cm ² or more, and (iii) ASTM D256
20 kg of Izod impact strength (IZ) at 23 ° C. measured on a 6.4 mm thick notched specimen according to the method of
And (iv) a heat distortion temperature (HDT) (4.6 kg load) measured under a load of 4.6 kg / cm ² according to ASTM D648 is 135 ° C. or more. It is characterized by having.

Further, the polypropylene composition according to the present invention further comprises 13
The composition may be heat-treated at 5 to 165 ° C. for 20 to 180 minutes, and the heat-treated polypropylene composition comprises (i)
Cross head speed 2mm according to ASTM D790
Flexural modulus (FM) measured under the condition of
00kg / cm ² or more, (ii) in accordance with the method of ASTM D256, Izod impact strength at 23 ° C. as measured by 6.4mm thick notched test piece (IZ) is 40 kg · cm
(Iii) a heat distortion temperature (HDT) of 150 ° C. or more measured under a load of 4.6 kg / cm ² in accordance with ASTM D648, and (iv) an ASTM D
It is characterized in that the low-temperature embrittlement temperature (BTc) measured according to 746 is -30 ° C or less, and (v) the long period measured by the small-angle X-ray scattering method is 200 ° or more.

[0014]

Polypropylene composition according to the present invention DETAILED DESCRIPTION OF THE INVENTION, (A) and the propylene block copolymer, (B) and the ethylene-1-butene random copolymer, (C) an inorganic filler (fine powder Talc) .

First, each component used for forming the polypropylene composition according to the present invention will be specifically described. (A) The propylene block copolymer (A) used in the present invention the propylene block copolymer, a highly crystalline homopolymer polypropylene component, room temperature (2
3 ° C.) It is preferable to comprise an ethylene-propylene copolymer rubber component which is an n-decane soluble component.

[0016] Such (A) used in the present invention the propylene block copolymer is satisfying specific propylene block copolymer as described below. (1) 230 ° C. according to ASTM D1238;
Melt flow rate (MF) measured under a load of 16 kg
R) is 10 to 60 g / 10 min, preferably 15 to 40 g
/ 10 minutes.

A composition formed from a propylene- based block copolymer having an MFR of less than 10 g / 10 minutes has low flowability, poor moldability, and may not be able to mold a large product, while having an MFR of 60 g. A composition formed from a propylene- based block copolymer exceeding / 10 minutes tends to have poor IZ impact strength.

(2) 23 ° C. n-decane-soluble components are contained in an amount of 3 to 13% by weight, preferably 4 to 10% by weight.
Propylene containing less than 3% by weight of n-decane soluble component at 23 ° C
The composition formed from the system block copolymer may have poor IZ impact strength, while the amount of n-decane soluble component is 13%.
A composition formed from a propylene- based block copolymer in an amount of more than 10% by weight may have poor rigidity.

(3) The polypropylene component of the propylene- based block copolymer has a melt flow rate (MFR)
But 20 to 200 g / 10 min, preferably 20 to 80 g /
It is 10 minutes, more preferably 20 to 60 g / 10 minutes.

The polypropylene component has an MFR of 20 g / 10
The composition formed from the propylene- based block copolymer having a viscosity of less than 1 minute has low fluidity, is inferior in moldability, and may not be able to mold a large product, while the MFR of the polypropylene component exceeds 200 g / 10 minutes. Compositions formed from propylene- based block copolymers may have poor IZ impact strength.

This polypropylene component has a ¹³ C-NMR
Isotacticity I determined by the method
₅ is 0.97 or more, preferably 0.98 or more.
I ₅ polypropylene component, composition formed from the propylene block copolymer is less than 0.97 tends to be inferior in rigidity.

(4) The 23 ° C. n-decane soluble component is 1
The intrinsic viscosity [η] measured in decalin at 35 ° C. is 4-1.
It is 2 dl / g, preferably 5 to 8 dl / g. A composition formed from a propylene- based block copolymer in which the intrinsic viscosity [η] of the polypropylene component is less than 4 dl / g may have poor IZ impact strength, while the intrinsic viscosity [η] of the polypropylene component is 12 dl / g. The composition formed from a propylene- based block copolymer having a viscosity of more than 10% may have low fluidity and poor moldability.

This 23 ° C. n-decane soluble component contains 30 to 60 mol%, preferably 35 to 45 mol%, of a structural unit derived from ethylene. 23 ℃ n-
A composition formed from a propylene- based block copolymer in which the constituent unit derived from ethylene in the decane-soluble component is less than 30 mol% or more than 60 mol% may have poor IZ impact strength. .

[0024] (A) used in the present invention the propylene Bed <br/> lock copolymer, the constituent units derived from ethylene, in the copolymer, 2-9 mol%, preferably from 2 to 8
Desirably, it is contained in an amount of mol%.

A composition formed from a propylene- based block copolymer having less than 2 mol% of a constituent unit derived from ethylene may have poor IZ impact strength. The composition formed from the contained propylene- based block copolymer may have poor rigidity.

[0026] Note that 23 ° C. n- decane-soluble component as described above, after the sample (propylene block copolymer) 5 g, was dissolved 5 hours immersed in a boiling n- decane 200 cc, then cooled to room temperature This is a value calculated from the weight of the solid phase, which is measured after the precipitated solid phase is filtered through a G4 glass filter, dried, and measured.

The content of the structural unit derived from ethylene can be determined by measuring the propylene- based block copolymer or the n-decane-soluble component by a conventional method such as infrared spectroscopy and NMR.

The pentad isotacticity I ₅ is
Macromolec by A. Zambelli et al.
ules 6, 925 proposed (1973) method i.e. ¹³ C-N
It is an isotactic fraction in pentad units in a polypropylene molecular chain measured by an MR method (nuclear magnetic resonance method), and is a fraction of propylene monomer units in which five consecutive propylene units are isotactically bonded. .

The assignment of peaks in the above-mentioned NMR measurement is performed based on the description in Macromolecules 8 , 687 (1975). ¹³ C-NMR is a Fourier transform NMR [5
00 MHz (at the time of hydrogen nuclei measurement)]
By performing the integration measurement at 20,000 times at 25 MHz, the measurement can be performed with the signal detection limit improved to 0.001.

The propylene block copolymer used in the present invention ethylene / propylene copolymer component in (A) (23 ℃ n- decane soluble component) is within a range that does not impair the object of the present invention, other than ethylene and propylene And a structural unit derived from a polymerizable monomer of the formula (I).

Such other polymerizable monomers include:
Specifically, for example, 1-butene, 1-pentene, 1-hexene,
Α-olefins such as 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadodecene, 4-methyl-1-pentene, vinylcyclopentene, vinylcyclohexane,
Examples include vinyl compounds such as vinyl norbornane, vinyl esters such as vinyl acetate, unsaturated organic acids such as maleic anhydride, and derivatives thereof.

The propylene block copolymer (A) used in the present invention comprises a terpolymer of ethylene, propylene and other polymerizable monomers in the rubber part, and a terpolymer of ethylene and propylene in the rubber part. It may be a mixture with a propylene-based block copolymer, which is a copolymer.

Further propylene Bro <br/> click copolymer (A) used in the invention is 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1- Pentene, 3-methyl-1-
Hexene, 3,5,5-trimethyl-1-hexene, vinylcyclopentene, vinylcyclohexane, vinyl norbornane and other homopolymers or copolymers, for example, as containing a prepolymer formed by prepolymerization, High crystallization rate.

[0034] When used in the present invention (A) propylene-based blanking <br/> locking copolymer is at MFR values as described above, the polypropylene composition formed therefrom as will be described later, excellent fluidity Also, molding of large molded products is easy. A molded article of a polypropylene composition containing a polypropylene having a melt flow rate higher than the above may have poor impact strength.

When the (A) propylene- based block copolymer contains the rubber component in the above amount, the polypropylene composition formed therefrom has excellent flexural modulus and impact strength and low-temperature toughness. (A)
When the amount of the rubber component in the propylene- based block copolymer is larger than the above amount, the composition formed therefrom may be inferior in flexural modulus, while the rubber component is too small than the above amount. The composition formed therefrom may be inferior in impact strength and low-temperature toughness.

The propylene block copolymer used in the present invention as described above, can be produced by various methods, for example, it can be produced using a stereoregular catalyst. Specifically, it can be produced using a catalyst formed from a solid titanium catalyst component, an organometallic compound catalyst component, and, if necessary, an electron donor.

In the present invention, the solid titanium catalyst component specifically includes titanium trichloride or a titanium trichloride composition supported on a carrier having a specific surface area of 100 m ² / g or more. Or magnesium, a halogen, an electron donor (preferably an aromatic carboxylic acid ester or an alkyl group-containing ether) and titanium as essential components, and these essential components have a specific surface area of 100 m ² /
g of a solid titanium catalyst component supported on a carrier having a weight of at least g. Of these, the latter solid titanium catalyst component is particularly preferred.

The organometallic compound catalyst component is preferably an organoaluminum compound. Specific examples of the organoaluminum compound include trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, and alkylaluminum dihalide. The organoaluminum compound can be appropriately selected according to the type of the titanium catalyst component used.

As the electron donor, an organic compound having a nitrogen atom, a phosphorus atom, a sulfur atom, a silicon atom, a boron atom or the like can be used, and preferably, an ester compound and an ether compound having the above-mentioned atoms. Is mentioned.

Such a catalyst may be further activated by a method such as co-milling, or the above-mentioned olefin may be prepolymerized. (B) Ethylene / 1-butene random copolymer (1) The (B) ethylene / 1-butene random copolymer used in the present invention comprises one unit derived from 1-butene.
It is contained in an amount of 5 to 25 mol%, preferably 15 to 22 mol%.

A composition formed from a propylene-based block copolymer in which the structural unit derived from 1-butene is less than 15 mol% may have poor impact resistance, while the composition unit may contain 25 mol%. The composition formed from the propylene-based block copolymer having more than the above may have poor rigidity.

The (B) ethylene / 1-butene random copolymer used in the present invention has the following physical properties. (2) Intrinsic viscosity [η] measured in decalin at 135 ° C
But 1.8 to 3.5 dl / g, preferably 2.0 to 3.0 dl / g
dl / g.

A composition formed from an ethylene / 1-butene random copolymer having an intrinsic viscosity [η] of less than 1.8 dl / g may have poor IZ impact strength, while an intrinsic viscosity [η] of 3 A composition formed from an ethylene / 1-butene random copolymer exceeding 0.5 dl / g may have low flowability and poor moldability.

(3) The glass transition temperature is −55 ° C. or lower, preferably −60 ° C. or lower, or the melting point measured as the main peak by the DSC method is 90 ° C. or lower, preferably 80 ° C. or lower, particularly Preferably it is 70 ° C. or lower.

A composition formed from an ethylene / 1-butene random copolymer having a glass transition temperature exceeding -55 ° C. or a melting point exceeding 90 ° C. may have poor IZ impact strength.

(4) The degree of crystallinity measured by the X-ray diffraction method is 20% or less, preferably 10% or less. A composition formed from an ethylene / 1-butene random copolymer having a crystallinity exceeding 20% may have poor IZ impact strength.

(5) The ethylene (B) used in the present invention
The 1-butene random copolymer has a parameter (B value) of 1.0 to 1.4, which indicates the randomness of the copolymer monomer chain distribution determined by the ¹³ C-NMR method.

A composition formed from an ethylene / 1-butene random copolymer having a B value of less than 1.0 may have poor IZ impact strength, while an ethylene / 1-butene having a B value of more than 1.4 may be inferior.
Compositions formed from butene random copolymers may have poor rigidity.

The B value in the (B) ethylene / 1-butene random copolymer is an index indicating the composition distribution of the structural units derived from each monomer in the copolymer chain. The mole fraction of the ethylene-1-butene alternating chains relative to the total dyad chains in the figure is divided by twice the product of the ethylene content (mole fraction) and the 1-butene content (mole fraction). That is, the B value is obtained by the following equation.

[0050]

(Equation 1)

[0051] (wherein, P _E and P _B each represent mole fractions of the mole fraction and 1-butene component of the ethylene component contained in the ethylene-1-butene copolymer, P _BE is the total dyad chain 1-butene -. a molar fraction of ethylene chain) such P _E, P _B and P _bE values are specifically obtained as follows.

Approximately 200 mg of ethylene / 1-butene copolymer is uniformly dissolved in 1 ml of hexachlorobutadiene in a 10 mmφ sample tube, and the ¹³ C-NMR spectrum of this sample is measured under the following measurement conditions.

Measurement temperature: 120 ° C., measurement frequency: 125 MHz, number of integration: 5000 times.

The values of P _E , P _B and P _BE were determined from the ¹³ C-NMR spectrum measured as described above. J.
Ray (Macromolecules, 10 , 773 (1977)); C. Rand
all (Macromolecules, 15 , 353 (1982)); Polymer S
cience, Polymer Physics Ed., 11 , 275 (1973)); Ki
It can be determined based on the report of mura (Polymer, 25 , 441 (1984)).

The B value becomes 2 when the ethylene / 1-butene random copolymer is a completely alternating copolymer, and becomes 0 when it is a completely block copolymer. If the B value is 1.
A polypropylene composition containing (B) an ethylene / 1-butene random copolymer smaller than 0 tends to have a reduced impact resistance.

The ethylene / 1-butene random copolymer (B) has excellent compatibility with polypropylene,
A polypropylene composition containing this copolymer,
Since it has excellent rigidity, excellent impact resistance, and excellent fluidity, it is possible to form a molded article having excellent appearance.

The ethylene / 1-butene random copolymer (B) described above can be produced using a vanadium catalyst or a metallocene catalyst. (C) Fine powder talc As the (C) fine powder talc used in the present invention, conventionally known fine talc used as a modifier such as polyolefin is used.

In the present invention, the fine powder talc (C) has an average particle size of 0.5 to 20 μm, and a ratio of aspect ratio to aspect ratio (aspect ratio) is 2 times or more, preferably 10 times or more. Fine powder talc is preferred.

This (C) fine powder talc has a particle size of 5 μm.
It is desirable that the content of particles having a particle size of m or more is 5% by weight or less. Polypropylene Composition The polypropylene composition according to the present invention comprises the above-mentioned (A) propylene-based block copolymer in an amount of 60 to 85% by weight, preferably 65 to 77% by weight, and (B) ethylene / 1 -Butene random copolymer in an amount of 10 to 25% by weight, preferably 15 to 25% by weight, and (C) an inorganic filler in an amount of 5 to 15% by weight, preferably 8 to 14% by weight. doing.

The polypropylene composition according to the present invention is a kneaded product of these components, and can be obtained by preparing (kneading) a conventionally known resin composition from each component. Specifically, each component is charged simultaneously or sequentially, for example, into a Henschel mixer, a V-type blender, a tumbler blender, a ribbon blender, etc., and after kneading, a single-screw extruder, a multi-screw extruder, a kneader, It is obtained by melt-kneading with a Banbury mixer or the like.

[0061] Among these, when a device having excellent kneading performance such as a multi-screw extruder, a kneader, and a Banbury mixer is used, a high-quality polypropylene composition in which each component is more uniformly dispersed can be obtained. preferable.

The polypropylene composition (kneaded product) according to the present invention satisfies the following specific conditions. (i) Melt flow rate measured according to ASTM D1238 (MFR: 230 ° C., under 2.16 kg load)
However, it is 8 g / 10 min or more, preferably 10 to 50 g / 10 min.

(Ii) The flexural modulus (FM) measured at a crosshead speed of 2 mm / min according to ASTM D790 is 20,000 kg / cm ² or more, preferably 200
It is 00 to 25000 kg / cm ² .

(Iii) According to the method of ASTM D256, the Izod impact strength (IZ) at 23 ° C. of not less than 20 kg · cm / cm measured on a 6.4 mm-thick notched test piece is as follows:
It is preferably at least 25 kg · cm / cm.

(Iv) The heat distortion temperature (HD) measured under a load of 4.6 kg / cm ² in accordance with ASTM D648
T) (4.6 kg load) is 135 ° C or more.

The polypropylene composition according to the present invention has a high crystallization rate of the propylene block copolymer (A) used as a raw material, and the polypropylene component is dispersed as many very fine crystals in the rubber component during molding. To form a molecular composite polymer alloy.

The polypropylene composition according to the present invention is excellent in rigidity, heat resistance and surface hardness, and also excellent in impact resistance. In the polypropylene composition according to the present invention, the above-mentioned polypropylene composition (kneaded material) may be further heat-treated under specific conditions. Prior to the heat treatment, the polypropylene composition may be formed by injection molding or the like.

The heat-treated polypropylene composition according to the present invention is prepared by mixing the kneaded product (or molded product) obtained as described above at 135 to 165 ° C., preferably 140 to 165 ° C.
It is obtained by heat treatment at 55 ° C. for 20 to 180 minutes, preferably 30 to 60 minutes. Such heat treatment
It can be performed by an oven or the like. This heat treatment can also be performed using a coating step of a molded article.

The heat treatment can be carried out by changing conditions such as temperature and time within the above range. If the heat treatment time is shorter than the above time, a polypropylene composition (heat treatment product) which sufficiently satisfies the following conditions may not be obtained.

The heat-treated polypropylene composition according to the present invention has the following specific properties. (i) The flexural modulus (FM) measured at a crosshead speed of 2 mm / min in accordance with ASTM D790 is 2
3000 kg / cm ² or more, preferably 23000 to 250
00kg / cm is ^2, (ii) in accordance with the method of ASTM D256, 2 measured at 6.4mm thickness with notch specimen
Izod impact strength (IZ) at 3 ° C is 40 kg · cm / cm
Or more, preferably at least 45 kg · cm / cm, particularly preferably at least 50 kg · cm / cm, and (iii) ASTM D648.
The heat distortion temperature (HDT) measured under the condition of a load of 4.6 kg / cm ² is 150 ° C. or higher in accordance with (iv) AS
Low temperature embrittlement temperature (B) measured in accordance with TM D746
Tc) is −30 ° C. or less, and (v) the long period measured by the small-angle X-ray scattering method is 200 ° or more, preferably 205 ° or more.

The long period measured by the small-angle X-ray scattering method is a scattering period derived from the crystal part (homopropylene component) of the propylene block copolymer contained in the polypropylene composition, and the period is long. It can be said that the polypropylene composition is excellent in rigidity and heat resistance, and is also excellent in impact strength and low-temperature embrittlement temperature.

The heat-treated polypropylene composition according to the present invention as described above is remarkably excellent in all of the flexural modulus, heat deformation temperature, impact strength, low-temperature impact strength, and low-temperature toughness.

The polypropylene composition according to the present invention may further comprise a heat-resistant stabilizer, a nucleating agent such as an aromatic carboxylic acid aluminum salt, an aromatic phosphate ester salt, dibenzylidene sorbitol, or an ultraviolet ray as long as the object of the present invention is not impaired. Absorbents, lubricants, antistatic agents, flame retardants, pigments, dyes, inorganic fillers other than fine powder talc, organic fillers, other polymers such as polyethylene (PE), propylene / ethylene random copolymer (EPR), etc. May be contained.

[0074]

The polypropylene composition according to the present invention comprises:
In addition to excellent rigidity and heat resistance, various properties such as impact resistance, especially low-temperature impact resistance and toughness, are remarkably superior to conventionally known polypropylene compositions.

The polypropylene composition according to the present invention can be used for a wide range of applications, and is particularly suitably used for automotive interior and exterior materials such as bumpers.

[0076]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

In the following examples, each physical property was measured as follows. (1) MFR: Measured according to ASTM D1238. Conditions: 230 ° C., 2.16 kg (2) Flexural modulus (FM): Measured in accordance with ASTM D790.

Test piece 12.7 mm (width) x 6.4 mm (thickness)
× 127mm (length) 100mm between spans Bending speed 2mm / min (3) Izod impact strength (IZ): ASTM D256
It measured according to.

Temperature 23 ° C. Test piece 12.7 mm (width) × 6.4 mm (thickness) × 64 mm (length) Notch was machined. (4) Heat distortion temperature (HDT) Measured in accordance with ASTM D648.

Load 4.6 kg / cm ² (5) Low temperature embrittlement temperature (BTc) Measured in accordance with ASTM D746.

A test piece was punched out from a 2 mm thick square plate. 4.0 mm (width) x 2.0 mm (thickness) x 38.0 mm (length) (6) How to determine long period by small-angle X-ray scattering.

The small-angle X-ray scattering intensity was measured by a model RU-200A manufactured by Rigaku Denki KK, and the long period was calculated from the scattering angle showing the peak according to the Bragg equation. The wavelength of the X-ray is 1.5418 °.

(7) The intrinsic viscosity [η] was measured at 135 ° C. in decalin. Further, the following Examples 1 to 4 and Comparative Examples 1 to
In 7, the components used in preparing the polypropylene composition are as follows. (A) Propylene block copolymer Block PP1: (1) MFR; 20 g / 10 min. (2) n-decane soluble component at normal temperature; 5 wt% (3) MFR of polypropylene component; 28 g / 10 min, pentad Isotacticity I ₅ ; 0.98 (4) Intrinsic viscosity [η] of n-decane soluble component at normal temperature: 5.5 dl
/ G, constituent unit derived from ethylene; 40 mol% Block PP2: (1) MFR; 20 g / 10 min (2) n-decane soluble component at normal temperature; 8 wt% (3) MFR of polypropylene component; 35 g / 10 minutes, pentad isotacticity I ₅ ; 0.98 (4) intrinsic viscosity of normal temperature n-decane soluble component [η]; 7.0 dl
/ G, structural unit derived from ethylene; 40 mol% Block PP3: (1) MFR; 20 g / 10 min (2) n-decane soluble component at normal temperature; 5 wt% (3) MFR of polypropylene component; 28 g / 10 minutes, pentad isotacticity I ₅ ; 0.95 (4) intrinsic viscosity [η] of n-decane soluble component at room temperature; 5.5 dl
/ G, constituent unit derived from ethylene; 40 mol% Block PP4: (1) MFR; 20 g / 10 min (2) n-decane soluble component at normal temperature; 5 wt% (3) MFR of polypropylene component; 10 minutes, pentad isotacticity I ₅ ; 0.98 (4) intrinsic viscosity [η] of n-decane soluble component at room temperature; 3.0 dl
/ G, structural unit derived from ethylene; 40 mol% homo-PP: MFR; 20 g / 10 min I ₅ ; 0.98 EBR-1: ethylene / 1-butene random copolymer (1) derived from 1-butene (2) intrinsic viscosity [η]; 2.5 dl / g (3) glass transition temperature (Tg); -64 ° C. (4) crystallinity; 5% (5) B value; 1.1 EBR-2: ethylene / 1-butene random copolymer (1) Structural unit derived from 1-butene; 11 mol% (2) Intrinsic viscosity [η]; 2.5 dl / g (3) Glass Transition temperature (Tg); -53 ° C. (4) Crystallinity; 15% (5) B value; 1.1 EPR: ethylene / propylene random copolymer Structural unit derived from propylene; 20 mol% Intrinsic viscosity [ η]; 2.6 dl / g Glass transition temperature (Tg); -54 ° C. Crystallinity; 4% B value; 1.1 PER: ethyl Propylene random copolymer Structural unit derived from propylene; 60 mol% intrinsic viscosity [η]; 3.0 dl / g Glass transition temperature (Tg); -53 ° C Crystallinity; 10% B value; 9 (C) Talc: average particle size; 2.5 μm Content of particles having a particle size of 5 μm or more; 3% by weight

[0084]

Examples 1 to 4 The components shown in Table 1 were dry blended and kneaded at 200 ° C. using a twin screw extruder to obtain a polypropylene composition. ASTM test pieces were molded from each of the obtained polypropylene compositions using an injection molding machine under the conditions of a resin temperature of 200 ° C. and a mold temperature of 40 ° C., and the above-mentioned physical properties of each test piece were measured.

Table 1 shows the results.

[0086]

Comparative Examples 1 to 7 ASTM test pieces were molded in the same manner as in Example 1 except that the polypropylene composition shown in Table 1 was used, and the physical properties of each test piece were measured.

Table 1 shows the results.

[0088]

[Table 1]

FIG. 1 shows the balance between IZ impact strength and FM with respect to the physical properties of the examples and comparative examples shown in Tables 1 to 3. It can be seen that the polypropylene composition according to the present invention obtained in the examples has a better balance of physical properties than the polypropylene composition obtained in the comparative example.

[0090]

Examples 5 to 10 The following Examples 5 to 10 and Comparative Examples 8 to
In 10, the components used in preparing the polypropylene composition are as follows.

[0091] PP-A ^{* 1):} propylene block copolymer (1) MFR; structural unit derived from 20 g / 10 min ethylene; 5.9 mol% (2) 23 ℃ n- decane soluble content 8% by weight (3) MFR of polypropylene component; 28 g / 10 min Pentad isotacticity I ₅ ; 0.98 (4) Intrinsic viscosity [η] of 23 ° C. n-decane soluble component; 5.5 dl / g constituent units derived from ethylene; 40 mol% PP-B ^{* 2):} propylene block copolymer (1) MFR; structural unit derived from 20 g / 10 min ethylene; 7.0 mol% (2) 23 (3) MFR of homopolypropylene component; 31 g / 10 min. Pentad isotacticity I ₅ ; 0.98 (4) Intrinsic viscosity of 23 ° C n-decane soluble component [Η]; a structural unit derived from 5.5 dl / g ethylene; 40 mol% homo PP ^{* 3)} : 0 mol% of structural units derived from ethylene MFR; 20 g / 10 min Pentad isotacticity I ₅ ; 0.98 EBR ^{* 4)} : ethylene / 1-butene random copolymer MFR: 0.8 g / 10 min Structural unit derived from 1-butene; 18 mol% Structural unit derived from ethylene; 82 mol% Decalin intrinsic viscosity [η]; 2.3 dl / g Melting point (Tm); ° C Crystallinity; 6% B value; 1.1 EPR ^{* 5)} : ethylene / propylene random copolymer Structural unit derived from propylene; 19 mol% Structural unit derived from ethylene; 81 mol% MFR; 0.8 g / 10 min Talc: average particle size 2.5 μm Content of particles having a particle size of 5 μm or more 3 wt%

[0092]

Example 5 PP-A, EBR and talc were dry-blended in the proportions shown in Table 1 and then 200 ° C. using a twin-screw extruder.
To obtain a polypropylene composition. The obtained polypropylene composition was injection molded at a cylinder temperature of 200 ° C. and a mold temperature of 40 ° C. using a 55-ton in-line screw injection molding machine manufactured by Toshiba Machine Co., Ltd. to obtain a test piece of the polypropylene composition. This test piece was heat-treated in an air oven at 155 ° C. for 1 hour.

Table 2 shows the results. The polypropylene composition (heat-treated product) obtained as described above was excellent in impact resistance (IZ), rigidity (FM), low-temperature toughness (BTc), and heat resistance (HDT). The long period determined by the small-angle X-ray scattering method was 210 °.

[0094]

In Example 6-10 Example 5, a propylene-based blanking <br/> lock copolymer, except that the blending ratio and heat treatment conditions were changed as shown in Table 2, polypropylene composition in the same manner as in Example 5 A heat-treated product was obtained.

Table 2 shows the results. The polypropylene composition (heat-treated product) obtained as described above was excellent in impact resistance (IZ), rigidity (FM), low-temperature toughness (BTc), and heat resistance (HDT). The long periods obtained by the small-angle X-ray scattering method were all 200 ° or more.

[0096]

Comparative Example 8 A test piece of a polypropylene composition was obtained in the same manner as in Example 5, except that EBR was replaced with EPR and no heat treatment was performed.

Table 2 shows the results. As compared with the test piece of Example 2, the sample was inferior in impact resistance, rigidity, heat resistance, and low-temperature toughness. The long period obtained by the small-angle X-ray scattering method is 1
It was 60 degrees.

[0098]

Comparative Example 9 A test piece of a polypropylene composition was obtained in the same manner as in Example 5, except that EBR was changed to EPR.

Table 2 shows the results. As compared with the test piece of Example 5, the impact resistance, rigidity, heat resistance, and low-temperature toughness were inferior. The long period obtained by the small-angle X-ray scattering method is 1
It was 96Å.

[0100]

In Comparative Example 10] Example 5, a propylene-based block <br/> click copolymer instead of homopolypropylene, except that the EBR and talc were used in a blend ratio shown in Table 2, in the same manner as in Example 5 Thus, a test piece of the polypropylene composition was obtained.

Table 2 shows the results. As compared with the sample obtained in Example 5, a sample inferior in impact resistance, rigidity, heat resistance and low-temperature toughness was obtained. The long period obtained by the small-angle X-ray scattering method was 198 °.

[0102]

[Table 2]

[Brief description of the drawings]

FIG. 1 shows the balance between IZ impact strength and FM of a polypropylene composition.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mikio Hashimoto 1-2-1, Waki, Waki-machi, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Petrochemical Industry Co., Ltd. 6-1-2 Kimachi Waki Mitsui Petrochemical Industry Co., Ltd. (56) References JP-A-62-150 (JP, A) JP-A-62-256856 (JP, A) JP-A-5-98126 ( JP, A) JP-A-5-59250 (JP, A) JP-A-5-98127 (JP, A) JP-A-64-66263 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) C08L 53/00 C08K 3/34 C08L 23/04-23/08

Claims (2)

(57) [Claims] (A) (1) A melt flow rate measured according to ASTM D1238 (MFR: 230 ° C.,
2.16 kg load) is 10 to 60 g / 10 min, (2)
Containing normal temperature n-decane soluble components in an amount of 3 to 13% by weight;
(3) The polypropylene component has an MFR of 20 to 80 g / 10
Pentad isotacticity (I ₅ ) determined by ¹³ C-NMR method is 0.97 or more;
(4) The n-decane soluble component at room temperature has an intrinsic viscosity [η] of 4-1.
2 dl / g, and the structural unit derived from ethylene is 3
(B) (1) 15 to 2 structural units derived from 1-butene;
5 mol%, (2) decalin intrinsic viscosity [η] is 1.8 to 3.5 dl / g, and (3) glass transition temperature (T
g) is −55 ° C. or less, or the melting point measured as a main peak by the DSC method is 90 ° C. or less,
(4) The crystallinity measured by the X-ray diffraction method is less than 20%, and (5) the randomness parameter (B value) determined by the ¹³ C-NMR method is 1.0 to 1.4. Ethylene / 1-butene random copolymer 10 to 25% by weight
And (C) 5 to 15% by weight of an inorganic filler; (i) a melt flow rate (MFR) of 8 g / 10 min or more; (ii) a crosshead speed of 2 mm / min in accordance with ASTM D790. The flexural modulus (FM) measured under the condition of min is 2
(Iii) 6.4 mm / cm ² according to the method of ASTM D256.
Has an Izod impact strength (IZ) at 23 ° C. of not less than 20 kg · cm / cm measured on a thick notched specimen, and (iv) a load of 4.6 kg / cm according to ASTM D648.
Heat distortion temperature (HDT) measured under the conditions of ² (4.6k
g load) is 135 ° C. or more. (A) (1) a melt flow rate (MFR: 230 ° C., measured according to ASTM D1238);
2.16 kg load) is 10 to 60 g / 10 min, (2)
Containing normal temperature n-decane soluble components in an amount of 3 to 13% by weight;
(3) The polypropylene component has an MFR of 20 to 80 g / 10
Pentad isotacticity (I ₅ ) determined by ¹³ C-NMR method is 0.97 or more;
(4) The n-decane soluble component at room temperature has an intrinsic viscosity [η] of 4
(B) (1) 1-butene derived from 1-butene, and 60 to 85% by weight of a propylene block copolymer containing a structural unit derived from ethylene in an amount of 30 to 60% by mole. 15 to 2 structural units
5 mol%, (2) decalin intrinsic viscosity [η] is 1.8 to 3.5 dl / g, and (3) glass transition temperature (T
g) is −55 ° C. or less, or the melting point measured as a main peak by the DSC method is 90 ° C. or less,
(4) The crystallinity measured by the X-ray diffraction method is less than 20%, and (5) the randomness parameter (B value) determined by the ¹³ C-NMR method is 1.0 to 1.4. Ethylene / 1-butene random copolymer 10 to 25% by weight
And (C) a polypropylene composition (1) comprising 5 to 15% by weight of an inorganic filler, which is obtained by heat-treating at 135 to 165 ° C for 20 to 180 minutes. (I) According to ASTM D790 And the flexural modulus (FM) measured under the condition of a crosshead speed of 2 mm / min is 2
And at 3000 kg / cm ² or more, (ii) in accordance with the method of ASTM D256, Izod impact strength at 23 ° C. as measured by 6.4mm thickness with notch test piece (IZ) is 40 kg · cm / kg or more (Iii) According to ASTM D648, a load of 4.6 kg /
The heat distortion temperature (HDT) measured under cm ² conditions is 15
0 ° C. or higher, (iv) the low-temperature brittleness temperature (BTc) measured according to ASTM D746 is −30 ° C. or lower, and (v) the long period measured by the small-angle X-ray scattering method is 200 °. The above is a polypropylene composition.