JPH06192504A - Polypropylene composition - Google Patents

Abstract

PURPOSE:To obtain a polypropylene composition having excellent rigidity, heat resistance and impact resistance. CONSTITUTION:A polypropylene composition comprises (A) 65-75 pts.wt. highly crystalline polypropylene having >=65% crystallinity measured by X-ray diffraction method, >=0.97 pendant isotacticity 15 measured by <13>C-NMR method, >=6 molecular weight distribution obtained by GPC method and 10-40g/10 minutes melt flow rate MFR and (B) 10-25 pts.wt. styrene ethylene/butylene styrene block copolymer and (C) 5-20 pts.wt. inorganic filler.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene composition having excellent rigidity and heat resistance as well as impact resistance.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Molded articles made of crystalline polypropylene are excellent in rigidity, heat resistance and surface gloss,
It is used for a wide range of purposes.

On the other hand, polypropylene is inferior in impact resistance, especially at low temperatures, and therefore its use is limited. In order to improve the impact resistance of such polypropylene, conventionally, polypropylene has been blended with polyethylene or a rubber-like substance such as polyisobutylene, polybutadiene, or an amorphous ethylene / propylene copolymer. Of these, amorphous or low crystalline ethylene / propylene random copolymers are often used. Furthermore, as an agent for improving the reduction in rigidity due to the addition of such a rubber-like substance, a polypropylene composition in which an inorganic filler such as talc is added and mixed with polypropylene is also proposed. For example, JP-A-60-5
No. 8459, No. 60-60154, No. 61-233048, No. 61-36348.
JP-A-62-235350, JP-A-63
-122751, JP-A-63-150343, JP-A-1-149845, and JP-A-1-204.
947, Japanese Patent Laid-Open No. 1-271450, etc.

However, the present inventors have studied a polypropylene composition comprising such a crystalline polypropylene and a rubber-like substance, particularly an amorphous or low crystalline ethylene / propylene random copolymer and talc, and as a result, amorphous Or low crystallinity ethylene / propylene random copolymer has a small impact resistance improving effect, and in order to improve impact resistance, ethylene / propylene
It is necessary to contain a large amount of propylene random copolymer. Therefore, this polypropylene composition has improved impact resistance, but has a problem that rigidity, heat resistance, and surface hardness are significantly reduced, and it cannot be used in applications requiring high rigidity. It was

As an alternative to such a conventional polypropylene composition, JP-A-63-156842 discloses a polypropylene composition comprising highly stereoregular polypropylene and styrene / ethylene / butylene / styrene block copolymer. Is proposed. Although this polypropylene composition is excellent in rigidity and impact resistance, it is desired to develop a polypropylene composition which is further excellent in rigidity and impact resistance depending on the use.

As a result of earnest studies in view of the above-mentioned conventional techniques, the present inventor has found that a specific highly crystalline polypropylene and styrene having a homopolypropylene component having a molecular weight distribution (M _w / M _n ) of 6 or more. The polypropylene composition comprising ethylene / butylene / styrene block copolymer (SEBS) and an inorganic filler has excellent heat resistance, and also has significantly excellent rigidity and impact resistance, thus completing the present invention. Came to do.

[0007]

OBJECT OF THE INVENTION It is an object of the present invention to provide a polypropylene composition having excellent rigidity and heat resistance as well as impact resistance.

[0008]

SUMMARY OF THE INVENTION The polypropylene composition according to the present invention has (A) a crystallinity of 65% as measured by X-ray diffractometry.
The pentad isotacticity I ₅ obtained by ¹³ C-NMR method is 0.97 or more,
The molecular weight distribution (M _w / M _n ) determined by the GPC method is 6 or more, and the melt flow rate MFR is 10 to 10.
40 g / 10 min high crystalline polypropylene; 65-7
5 parts by weight, (B) styrene / ethylene / butylene / styrene block copolymer; 10 to 25 parts by weight, and (C) inorganic filler; 5 to 20 parts by weight.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polypropylene composition according to the present invention will be specifically described. The polypropylene composition according to the present invention comprises (A) a highly crystalline polypropylene and (B)
It is composed of styrene / ethylene / butylene / styrene block copolymer and (C) an inorganic filler.

(A) Highly crystalline polypropylene The (A) highly crystalline polypropylene used in the present invention is
It is a specific polypropylene having the following physical properties.

(1) The crystallinity measured by X-ray diffractometry is 65% or more, preferably 70 to 75%. (2) The pentad isotacticity I ₅ determined by ¹³ C-NMR method is 0.97 or more, preferably 0.
It is 98 or more.

This pentad isotacticity I
Polypropylene having a value of ₅ but 0.97 or more has a high crystallization rate and is particularly excellent in rigidity. The pentad isotacticity I ₅ is A. Zambell.
i) et al., Macromolecules 6 , 925 (1973), that is, the isotactic fraction in the pentad unit in the polypropylene molecular chain measured by ¹³ C-NMR (nuclear magnetic resonance). .

Therefore, the pentad isotacticity (I ₅ ) is the fraction of propylene monomer units in which five propylene units are isotactically bonded in succession. The method for determining the attribution of peaks in the above NMR measurement is performed based on the description in Macromolecules 8 , 687 (1975). In addition, the measurement of NMR is performed by using a device of Fourier exchange NMR of 500 MHz (at the time of measuring hydrogen nucleus) at 125 M.
At a frequency of Hz, the signal detection limit was increased to 0.001 by I ₅ by performing integrated measurement 20000 times.

(3) The molecular weight distribution (M _w / M _n ) of the homopolypropylene component determined by the GPC method is 6 or more, preferably 8 or more, more preferably 10 to 12. The molecular weight distribution (M _w
If / M _n ) is less than 6, the rigidity of the molded product, particularly the injection molded product, obtained from the polypropylene composition containing this polypropylene will decrease.

(4) In accordance with ASTM-D1238, 2
Melt flow rate (MFR) measured at 30 ° C. under a load of 2160 g is 5 to 40 g / 10 min, preferably 15
It is desirable that the amount is -40 g / 10 min, more preferably 18-30 g / 10 min.

The polypropylene composition containing the (A) highly crystalline polypropylene having the above MFR has excellent fluidity and can easily form a large-sized molded product. A polypropylene composition containing polypropylene having a melt flow rate of more than 40 g / 10 min is inferior in impact strength.

The highly crystalline polypropylene (A) used in the present invention may be a homopolymer of propylene as long as it has such physical properties, and it is derived from an α-olefin other than propylene. It may be a propylene / α-olefin copolymer containing units in an amount of 10 mol% or less.

Examples of such α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene,
1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadodecene, 4-methyl-1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 3-methyl-1- Butene, 3,3-
Dimethyl-1-butene, diethyl-1-butene, trimethyl
-1-butene, 3-methyl-1-pentene, ethyl-1-pentene, propyl-1-pentene, dimethyl-1-pentene, methylethyl-1-pentene, diethyl-1-hexene, trimethyl-1-pentene, 3-methyl-1-hexene, dimethyl
-1-hexene, 3,5,5-trimethyl-1-hexene, methylethyl-1-heptene, trimethyl-1-heptene, dimethyloctene, ethyl-1-octene, methyl-1-nonene,
Examples thereof include vinylcyclopentene, vinylcyclohexane, vinylnorbornane and the like.

The copolymer of propylene and these α-olefins may be a random copolymer or a block copolymer. Further, propylene / α-olefin copolymers include 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1-pentene, 3-methyl-1-hexene, 3,
5,5-trimethyl-1-hexene, vinylcyclopentene,
It may be obtained by prepolymerizing a homopolymer or copolymer of vinylcyclohexane and vinylnorbornane on a catalyst and then polymerizing propylene on the prepolymerized catalyst.

In the present invention, the (A) highly crystalline polypropylene is preferably a propylene homopolymer. The polypropylene as described above can be produced by various methods, but can be produced by using an ordinary stereoregular catalyst. Specifically, it can be produced using a catalyst formed from a solid titanium catalyst component, an organometallic compound catalyst component, and optionally an electron donor.

As the solid titanium catalyst component used in this method, titanium trichloride or a titanium trichloride composition is supported on a carrier having a specific surface area of 100 m ² / g or more, or magnesium, halogen,
Examples of the titanium catalyst component include an electron donor (preferably an aromatic carboxylic acid ester or an alkyl group-containing ether) and titanium as essential components and a carrier having a specific surface area of 100 m ² / g or more and supported on a carrier. In particular, polypropylene produced by using the latter catalyst component with a carrier is suitable.

The organometallic compound catalyst component is preferably an organoaluminum compound, and specific examples of the organoaluminum compound include trialkylaluminum, dialkylaluminum halides, alkylaluminum sesquihalides, alkylaluminum dihalides and the like. The organoaluminum compound can be appropriately selected according to the type of 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 an ester compound and an ether compound having the above-mentioned atoms are preferable. Is mentioned.

Such a catalyst may be further activated by a method such as co-milling. Further, the olefin may be prepolymerized as described above. A method for producing polypropylene using the catalyst component with a carrier as described above is described in, for example, JP-A-50-108385 and JP-A-50-1265.
90, JP-A-51-20297, JP-A-51-28
No. 189, JP-A-52-151691, and the like, and the method for producing a propylene block copolymer is described in, for example, JP-A-52-98045 and JP-B-57-26613. Details are described in. Also in the present invention, the techniques described in these can be used.

(B) Styrene / Ethylene / Butylene / S
Tylene Block Copolymer The styrene / ethylene / butylene / styrene block copolymer (SEBS) (B) used in the present invention is a so-called thermoplastic elastomer composed of polystyrene block units and polyethylene / butylene rubber block units. Such (B) styrene, ethylene / butylene,
In the styrene block copolymer, the polystyrene block units, which are hard segments, form physical crosslinks (domains) and are present as bridging points of the rubber block units. The rubber block units existing between the polystyrene block units are soft. It is a segment and has rubber elasticity.

(B) Styrene / ethylene / butylene / styrene block copolymer (SEB) used in the present invention
S) usually contains polystyrene units in an amount of 10 to 70 mol% and polyethylene / polybutylene units in an amount of 90 to 30 mol%.

Such (B) styrene / ethylene / butylene / styrene block copolymer (SEBS) is 1
The intrinsic viscosity [η] measured in decalin at 35 degrees is usually 0.01 to 10 dl / g, preferably 0.08 to 7 dl / g.
and the glass transition temperature (Tg) is usually 0 ° C or lower, preferably -10 ° C or lower, and more preferably -20 ° C or lower. The crystallinity measured by the X-ray diffraction method is 0.
-10%, preferably 0-7%, more preferably 0-
5%.

This SEBS is specifically obtained by a known method described in, for example, Japanese Patent Publication No. 60-57463. More specifically, such a styrene / ethylene / butylene / styrene block copolymer (SEBS) is, for example, Kraton.
G1650, G1652, G1657, G1701 (manufactured by Shell Chemical Co., Ltd., trade name), Tuftec (manufactured by Asahi Kasei Co., Ltd., trade name), and the like.

SEBS used in the present invention is generally SB which is a styrene / non-conjugated diene block copolymer.
It is known as a hydrogenated product of S (PS-polybutadiene-PS) (where PS is polystyrene). In the present invention, SBS and other styrene / non-conjugated diene block copolymers or complete or incomplete hydrides thereof may be used together with SEBS.

Specific examples of such a styrene / non-conjugated diene block copolymer include SBR (PS-butadiene block copolymer), SBS (PS-polybutadiene-PS) and PS-polyisoprene block copolymer. Coalescence, SIS (PS-polyisoprene-PS) and SI
S hydrogenated products and the like, and more specifically, Kraton (Kraton: manufactured by Shell Chemical Co., Ltd.), Califlex TR (manufactured by Shell Chemical Co., Ltd.), Sorprene (manufactured by Philippe Petroleum Co., Ltd.), Europrene SOLT.
(Manufactured by Anich), Toughprene (manufactured by Asahi Kasei Co., Ltd.), Sorprene-T (manufactured by Nippon Elastomer Co., Ltd.), JSRTR
(Made by Japan Synthetic Rubber Co., Ltd.), electrified STR (made by Denki Kagaku Co., Ltd.),
Quintac (manufactured by Zeon Corporation), Kraton G (manufactured by Shell Chemical Co., Ltd.), Tuftec (manufactured by Asahi Kasei Co., Ltd.) (trade name) and the like.

(C) Inorganic Filler Specific examples of the (C) inorganic filler used in the present invention include fine powder talc, calcium carbonate, basic magnesium sulfate whiskers, calcium titanate whiskers, aluminum borate whiskers, and the like. Is mentioned. Among these, fine powder talc is preferable from the viewpoint of the appearance and rigidity of the molded product obtained from the polypropylene composition.

The fine powder talc used in the present invention has an average particle size of usually 1 to 3 μm, and the content of particles having a particle size of 5 μm or more is 3% by weight or less. Polypropylene composition The polypropylene composition according to the present invention comprises the above (A) highly crystalline polypropylene in an amount of 65 to 75 parts by weight, preferably 70 to 75 parts by weight, and (B) styrene / ethylene /
The butylene / styrene block copolymer is contained in an amount of 10 to 25 parts by weight, preferably 15 to 20 parts, and the inorganic filler (C) is contained in an amount of 5 to 20 parts by weight.

The polypropylene composition according to the present invention has excellent heat resistance and rigidity and impact resistance, especially at low temperature. The polypropylene composition according to the present invention is a nucleating agent such as polyethylene (PE), a heat stabilizer, an aromatic carboxylic acid aluminum salt, an aromatic phosphoric acid ester salt, and dibenzylidene sorbitol as long as the object of the present invention is not impaired. , UV absorbers, lubricants, antistatic agents, flame retardants, pigments, dyes, other polymers, inorganic fillers, other organic fillers and the like.

In the polypropylene composition according to the present invention, the above-mentioned components are simultaneously or sequentially charged into, for example, a Henschel mixer, a V-type blender, a tumbler blender, a ribbon blender, etc., and after kneading, a single-screw extruder is used. It can be obtained by melt-kneading with a multi-screw extruder, kneader, Banbury mixer or the like.

Among these, when a device having excellent kneading performance such as a multi-screw extruder, a kneader, a Banbury mixer, etc. is used, a high quality polypropylene composition in which the respective components are more uniformly dispersed can be obtained. preferable.

[0036]

The polypropylene composition according to the present invention is
It has excellent rigidity and heat resistance as well as impact resistance.

Such a polypropylene composition according to the present invention can be used in a wide variety of applications, and is particularly preferably used as an interior / exterior material for automobiles.

[0038]

EXAMPLES Next, the present invention will be specifically described 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) Based on MFR ASTM D1238. Conditions: 230 ° C., 2.16 kg (2) Flexural modulus (FM) According to ASTM D790.

Specimen 12.7 (width) × 6.4 (thickness) × 127 (length) Span span 100 mm Bending speed 2 mm / min (3) Izod impact strength (IZ) Temperature -30 according to ASTM D256 ° C Test piece 12.7 (width) x 6.4 (thickness) x 64 (length) Notch is machined. Each component used in the examples is shown below. (A) Highly crystalline polypropylene PP-A : highly crystalline polypropylene produced as follows Preparation of catalyst 135.2 g of anhydrous magnesium chloride, 442 ml of decane and 390.6 g of 2-ethylhexyl alcohol
After heating at 0 ° C. for 2 hours to form a uniform solution, 21.3 g of phthalic anhydride was added to this solution, and the mixture was stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in this uniform solution. It was The thus-obtained homogeneous solution was cooled to room temperature, and then 75 ml of the homogeneous solution was added dropwise to 200 ml of titanium tetrachloride kept at -20 ° C over 1 hour. After the charging is completed, the mixed solution is used for 11 hours over 11 hours.
The temperature was raised to 0 ° C., and when it reached 110 ° C., 5.22 g of diisobutyl phthalate (DIBP) was added, and the mixture was kept at the same temperature for 2 hours with stirring. After completion of the reaction for 2 hours, a solid portion was collected by hot filtration, and the solid portion was collected at
After resuspending with 1 part of titanium tetrachloride, it was heated again at 110 ° C. for 2 hours. After the reaction was completed, the solid portion was collected again by hot filtration, and thoroughly washed with decane and hexane at 110 ° C. until no free titanium compound was detected in the washing liquid.

The solid titanium catalyst component [A] prepared by the above operation was stored as a decane slurry. Polymerization In an autoclave with an internal volume of 17 liters, under a propylene atmosphere at room temperature, 4 kg of propylene was injected, 100 ml of hydrogen was added, and the temperature was raised to 50 ° C. 0.05 mmol of the above solid titanium catalyst component [A] in terms of Ti atom was added, and a polymerization reaction was carried out at this temperature for 90 minutes.

Thereafter, the hydrogen partial pressure at 50 ° C. is 6 kg / cm ²
Was added so that the temperature became 70 ° C., and the temperature was raised to 70 ° C. to carry out polymerization for 30 minutes. Immediately after completion of the reaction, a small amount of ethanol was added to the system to decompose the catalyst, and unreacted monomers and hydrogen were removed to obtain 1.9 kg of a white powdery solid.

The polypropylene thus obtained has an MFR of 17.0 g / 10 min, an I ₅ of 0.98 and an M _w
/ M _n was 12 and the crystallinity was 68%. PP-B : HYPOL J800 manufactured by Mitsui Petrochemical Co., Ltd. was used.

This polypropylene has an MFR of 25.0.
g / 10 minutes, I ₅ 0.96, M _w / M _n 5.1, and crystallinity 61%. PP-C : Polypropylene produced as follows.

The autoclave having an internal volume of 17 liters was sufficiently replaced with propylene, 4 kg of propylene and 45 liters of hydrogen were added, and the temperature was raised to 60 ° C., after which 5.0 mmol of triethylaluminum and dicyclopentyldimethoxysilane ( DCPMS) 5.0 mmol, 0.0 in terms of Ti atom of the solid titanium catalyst component [A].
5 mmol was added, the temperature was raised to 70 ° C., and polymerization was performed for 40 minutes.

The polypropylene thus obtained has an MFR of 15.0 g / 10 min, an I ₅ of 0.98 and an M _w
/ M _n was 5.2 and the crystallinity was 66%. PP-D : Highly crystalline polypropylene obtained by using a prepolymerization catalyst.

Prepolymerization of catalyst In a pressure resistant autoclave of 2 liter, under a nitrogen atmosphere, 20
Purified hexane 1 liter, triethylaluminum 100 mmol, methyltrimethoxysilane (TMM
S) 100 mmol and 10 mmol of the above solid titanium catalyst component [A] in terms of titanium atom were added and mixed with stirring, then 115 g of 3-methyl-1-butene was added, and prepolymerization was carried out for 2 hours while stirring at 20 ° C. The reaction was carried out. After completion of the reaction, the supernatant liquid was removed, washed twice with purified hexane, then resuspended in purified decane, and the whole amount was transferred to a catalyst bottle to obtain a prepolymerized catalyst.

Using the prepolymerization catalyst thus obtained, homo PP was polymerized in the same manner as in PP-A.
The polypropylene thus obtained has an MFR of 1
The amount was 5.5 g / 10 minutes, the I ₅ was 0.98, the M _w / M _n was 12, and the crystallinity was 72%. (B) Styrene-ethylene / butylene-styrene block copolymer (SEBS) is a product of Kraton.
n) G (manufactured by Shell Chemical Co., Ltd.) was used. (C) Talc: average particle size 2.5 μm, content of particles having a particle size of 5 μm or more 3% by weight Other polyethylene: Mitsui Petrochemical HiZex 13
00J

[0049]

Examples 1 to 4 The polypropylene compositions shown in Table 1 were
An ASTM test piece was molded with an injection molding machine under conditions of a resin temperature of 200 ° C. and a mold temperature of 40 ° C., and the above physical properties were measured.

The results are shown in Table 2.

[0051]

Comparative Examples 1 to 4 The polypropylene compositions shown in Table 1 were
Molding was performed in the same manner as in the example, and the physical properties were measured.

The results are shown in Table 2.

[0053]

[Table 1]

[0054]

[Table 2]

[Procedure amendment]

[Submission date] June 24, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction content]

Specimen 12.7 (width) × 6.4 (thickness) × 127 (length) Span span 100 mm Bending speed 2 mm / min (3) Izod impact strength (IZ) Temperature according to ASTM D256 23 ° C. Test piece 12.7 (width) x 6.4 (thickness) x 64 (length) Notch is machined Each component used in the examples is shown below. (A) Highly crystalline polypropylene PP-A : highly crystalline polypropylene produced as follows Preparation of catalyst 135.2 g of anhydrous magnesium chloride, 442 ml of decane and 390.6 g of 2-ethylhexyl alcohol
After heating at 0 ° C. for 2 hours to form a uniform solution, 21.3 g of phthalic anhydride was added to this solution, and the mixture was stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in this uniform solution. It was The thus-obtained homogeneous solution was cooled to room temperature, and then 75 ml of the homogeneous solution was added dropwise to 200 ml of titanium tetrachloride kept at -20 ° C over 1 hour. After the charging is completed, the mixed solution is used for 11 hours over 11 hours.
The temperature was raised to 0 ° C., and when it reached 110 ° C., 5.22 g of diisobutyl phthalate (DIBP) was added, and the mixture was kept at the same temperature for 2 hours with stirring. After completion of the reaction for 2 hours, a solid portion was collected by hot filtration, and the solid portion was collected at
After resuspending with 1 part of titanium tetrachloride, it was heated again at 110 ° C. for 2 hours. After the reaction was completed, the solid portion was collected again by hot filtration, and thoroughly washed with decane and hexane at 110 ° C. until no free titanium compound was detected in the washing liquid.

Claims (1)

[Claims] 1. (A) The degree of crystallinity measured by X-ray diffraction is 65% or more, and the pentad isotacticity I ₅ determined by ¹³ C-NMR is 0.97.
The above is the molecular weight distribution (M
_w / M _n ) is 6 or more and the melt flow rate M is
Highly crystalline polypropylene having an FR of 10 to 40 g / 10 minutes; 65 to 75 parts by weight, (B) styrene / ethylene / butylene / styrene block copolymer; 10 to 25 parts by weight, and (C) an inorganic filler. A polypropylene composition comprising 5 to 20 parts by weight.