JPH06179782A - Talc-containing propylene polymer composition - Google Patents

Abstract

PURPOSE:To provide a talc-containing propylene polymer composition having highly balanced rigidity and impact resistance and suppressed mold-staining trouble. CONSTITUTION:The talc-containing propylene polymer composition is composed of 100 pts.wt. of a crystalline propylene polymer, 3-100 pts.wt. of talc having a specific surface area of >=37,000cm<2>/g, a length of essentially <=15mum, an average particle diameter of 0.8-5mum and an average aspect ratio of >=5 and 0.1-8wt.% (based on the talc) of a zinc salt expressed by the formula (RCOO)2Zn (R is univalent hydrocarbon group having a molecular weight of 250-500 and optionally containing hydroxyl group).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition suitable for a molding material, in which the balance between rigidity and impact resistance is improved, and mold contamination is suppressed.

[0002]

2. Description of the Related Art Propylene polymers containing talc are
Utilizing its excellent mechanical strength, heat resistance, molding processability, etc., it is widely used for various purposes mainly in industrial parts such as automobiles. On the other hand, with the recent widespread use, the demand for mechanical strength is increasing. In particular,
There are extremely high demands for the balance between the contradictory properties of rigidity and impact strength. Therefore, various attempts have been made in the past. For example, studies have been conducted to improve impact strength by atomizing talc, improve impact strength by blending an ethylene-propylene copolymer rubber component, and improve impact strength by adding a dispersant such as a metal salt or wax. However, atomization of talc reduces impact strength due to secondary agglomeration, not only increases cost of compounding rubber components but also decreases rigidity, and addition of existing dispersant causes problems such as mold contamination. Development of more effective methods that we have is a very important issue.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a talc-containing propylene polymer composition having a high balance of rigidity and impact resistance, and suppressing mold contamination. .

[0004]

The present inventors have completed the present invention by finding that the above object can be achieved only by combining a specific talc and a dispersant together with a propylene polymer.

That is, according to the present invention, "100 parts by weight of a crystalline propylene polymer, a specific surface area of 37,000 cm ² / g or more, a length of substantially 15 μm or less, and an average particle size of 0.8 to 0.8.
Talc 3 to 10 with 5 μm and average aspect ratio of 5 or more
0 parts by weight and (RCOO) ₂ Z based on the amount of talc
Zinc salt represented by n (wherein R has a molecular weight of 250 to 5).
00 is a monovalent hydrocarbon group which may contain a hydroxyl group. ) 0.1 to 8% by weight, talc-containing propylene polymer composition ".

The present invention will be described in detail below. The crystalline propylene polymer used in the present invention is a homopolymer of propylene, a main weight ratio of propylene and a sub-weight ratio of other α-.
Olefin (for example, ethylene, 1-butene, 1-pentene, 1-hexene, 4-methylpentene-1,1-octene, etc.), vinyl ester (for example, vinyl acetate, vinyl butyrate, etc.), unsaturated carboxylic acid or its Examples thereof include copolymers such as block copolymers, random copolymers and graft copolymers with derivatives (for example, acrylic acid or its ester, maleic anhydride, etc.) and unsaturated aromatic compounds (for example, styrene, α-methylstyrene, etc.).

Specific preferred examples include polypropylene, propylene-ethylene block or random copolymer, propylene-ethylene-butene copolymer, and the like.
Of these, a propylene-ethylene block copolymer is preferable.

MFR of this polymer (JIS-K721
0, 230 ℃, 2.16kg) is 0.1-100g / 1
0 minutes, particularly preferably 1 to 50 g / 10 minutes.

These propylene polymers are usually produced with a Ziegler-Natta catalyst, but a catalyst obtained by supporting a catalyst component on a carrier such as magnesium chloride can also be used for this catalyst. The polymerization method may be a slurry method of polymerization in a solvent, a liquid phase method of polymerization in a liquid of propylene monomer, or a gas phase polymerization method.

The talc used in the present invention has a specific surface area of 3
Talc is 7,000 cm ² / g or more, the length is substantially 15 μm or less, the average particle size is 0.8 to 5 μm, and the average aspect ratio is 5 or more. Above all, the specific surface area is 40,000
Talc having a size of 0 cm ² / g or more, a length of substantially 10 μm or less, an average particle size of 0.8 to 4 μm, and an average aspect ratio of 6 or more is preferable. Here, “substantially” means that talc having a length other than the specified length may be included so long as the effect of the invention is not significantly impaired.

Talc whose specific surface area, length and average aspect ratio are out of the above ranges and whose average particle size exceeds the above range,
A high degree of balance between rigidity and impact resistance of the composition is not achieved. Further, talc having an average particle size of less than the above range has a drawback of poor impact resistance due to poor dispersion. The talc used in the present invention is obtained by crushing rough talc (preferably produced in China with less metal impurity components) by, for example, an impact type crusher or a micron mill type pulverizer, and further finely pulverized by a micron mill or jet mill type pulverizer. After that, it is manufactured by classifying and adjusting it with a cyclone or micron separator.

The particle size of talc is a value obtained by using a laser light scattering type particle size distribution meter, and as a measuring device, for example, LA-500 manufactured by Horiba Ltd. is desirable because of its excellent measuring accuracy. The specific surface area is measured by the air permeation method, and a measuring device is, for example, model SS-100 manufactured by Shimadzu Corporation. The length and aspect ratio are measured by a microscope method or the like.

The zinc salt represented by the above (RCOO) ₂ Zn used in the present invention (wherein R has a molecular weight of 250 to 500).
Is a monovalent hydrocarbon group which may contain a hydroxyl group. ) Is a metal salt of an organic acid such as arachidic acid, behenic acid, cerotic acid, montanic acid, melissic acid, abietic acid, dextropimaric acid and hydroxystearic acid. Specific examples include zinc behenate, zinc montanate, and zinc hydroxystearate. Above all,
Zinc behenate is preferred.

The blending ratio of each of the above essential components is 3 to 100 parts by weight, preferably 5 to 50 parts by weight, of talc with respect to 100 parts by weight of the crystalline propylene polymer, and a zinc salt of 0. 1 to 8% by weight, preferably 0.3 to
It is 5% by weight.

If the amount of talc is too small, the rigidity becomes insufficient,
On the other hand, if the amount is too large, it is not preferable in terms of impact resistance and moldability. Further, if the amount of zinc salt is too small, the effect of impact resistance is not exhibited, while if it is too large, the effect of suppressing die contamination is not exhibited and the problem of bleeding easily occurs.

In addition to these essential components, the composition of the present invention may contain other additional components as long as the effects of the present invention are not significantly impaired. Other additional components include, for example, ethylene resins such as low density polyethylene, medium or high density polyethylene, linear low density polyethylene, and ultra low density polyethylene; ethylene-propylene rubber, ethylene-butene rubber, styrene. -Butadiene rubber (including its hydrogenated product), styrene-isoprene rubber (including its hydrogenated product), etc .; Rubber component; condensed azo type, isoindolinone type, quinacridone type, perinone type, perylene type, quinophthalone type , Anthraquinone series,
Phthalocyanine-based organic pigments; inorganic oxides such as titanium oxide, titanium yellow, zinc white, iron black, carbon black, rouge, ultramarine blue; phenol-based, sulfur-based and phosphorus-based antioxidants; amine-based pigments Triazole-based, benzophenone-based, benzoate-based, nickel-based, salicylic acid-based light stabilizers; mica, silica, clay, calcium carbonate, glass fiber, barium sulfate fiber, potassium titanate fiber, nylon fiber or other inorganic or organic essential Fillers other than components; organic or inorganic nucleating agents; antistatic agents; lubricants; molecular weight modifiers (peroxides); metal deactivators; antibacterial agents; fluorescent brighteners; antiblocking agents, etc. Is mentioned.

The effects of the present invention are particularly enhanced in the above-mentioned pigment compounding system. The amount of pigment is usually
0.1 to 100 parts by weight of crystalline propylene polymer
It is about 30 parts by weight.

The composition of the present invention can be manufactured by a conventional method. For example, powdered propylene polymer, talc and zinc salt, and if necessary, other additional components are mixed, mixed with a Henschel mixer or the like, and then melt-kneaded with a uniaxial or biaxial kneading extruder to form pellets. Turn into. The pellets are processed by a molding machine such as an injection molding machine to form a desired molded body. The zinc salt can be made even more effective by previously mixing it with the talc component using a Henschel mixer or the like.

[0019]

【Example】

Examples 1 to 4 and Comparative Examples 1 to 6 In 100 parts by weight of propylene-ethylene block copolymer having MFR of 10 g / 10 minutes and ethylene content of 3.0% by weight,
Specific surface area of 41,000 cm ² / g, length less than 10 μm 98.2% and 15 μm or less 100%, average particle diameter 3.8 μm, talc having average aspect ratio 6 and zinc salt represented by the following abbreviations: Add the compounding amount shown in Table 1,
After mixing with a Henschel mixer, 2 with an extruder with a diameter of 30 mm
The mixture was kneaded at 30 ° C. and granulated into pellets. The pellets are molded with an injection molding machine at 240 ° C. and have a length of 80 mm,
A test piece having a width of 10 mm and a thickness of 4 mm was molded. The flexural modulus (according to JIS-K7203) was measured using this test piece. Also, length 120 mm, width 80 mm, thickness 2 m
m sheet was injection molded under the same conditions, and a dart having a diameter of 20 mm was dropped on the sheet to measure the impact energy (DIT) required for breaking.

Further, at a temperature of 220 ° C., about 50% of the basis weight of the injection-molded article was continuously molded, and the number of shots until the mold contamination started to be visible at the end of the filled resin was observed. The larger this value is, the better the effect of suppressing die contamination is.

<Content of Abbreviated Components Used> Zinc salt defined in the present invention BZ: Zinc behenate MZ: Zinc montanate HSZ: Zinc hydroxystearate Other metal salts RZ: Zinc laurate SZ: Zinc stearate SM: Magnesium stearate

In the above granulation, the following stabilizers and pigments were added and granulated. That is, as a stabilizer,
Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (trade name "IR1010") and tris (2,4-
Di-t-butylphenyl) phosphite (trade name "I
R168 ") for each 100 parts by weight of the propylene polymer, 0.11 parts by weight for each composition of Examples 1 to 3 and Comparative Examples 1 to 5, and Example 4 and Comparative Example 6 0.13 parts by weight was added to each composition. Moreover, as a pigment, Examples 1 to 3 and Comparative Examples 1 to 1
In each composition of No. 5, 0.22 part by weight of titanium oxide, 0.33 part by weight of phthalocyanine blue, 0.33 part by weight of ultramarine blue and 0.11 part by weight of quinacridone, based on 100 parts by weight of the propylene polymer, Example 4 and Comparative Example 6
In each composition, 0.25 part by weight of titanium oxide, 0.38 part by weight of phthalocyanine blue, 0.38 part by weight of ultramarine blue and 0.13 part by weight of quinacridone were added to 100 parts by weight of the propylene polymer. Table 1 shows the evaluation results.
As of.

Comparative Examples 7 and 8 Talc had a specific surface area of 28,600 cm ² / g and a length of 1
The evaluation was performed in the same manner as in the above example, instead of talc having a portion exceeding 5 μm of 34%, an average particle diameter of 12 μm, and an average aspect ratio of 4. The stabilizer and the pigment were added and granulated in the same manner as in the above example. The evaluation results are shown in Table 1.

[0024]

[Table 1]

[0025]

EFFECTS OF THE INVENTION According to the present invention, the propylene polymer composition having an improved balance between rigidity and impact resistance and suppressing mold contamination is obtained, which is a remarkable effect. The effect of the present invention is particularly great in injection-molded articles, for example, automobile bumpers, exterior parts such as instrument panels, interior parts, washing machine panels, refrigerator panels, home appliance parts such as TV housings, high-rigidity containers, Injection molded products such as food containers for microwave ovens, margarine and butter containers are effective.

Claims (6)

[Claims] 1. A crystalline propylene polymer of 100 parts by weight,
3 to 100 parts by weight of talc having a specific surface area of 37,000 cm ² / g or more, a length of substantially 15 μm or less, an average particle size of 0.8 to 5 μm and an average aspect ratio of 5 or more, and
A zinc salt represented by (RCOO) ₂ Zn with respect to the amount of talc (wherein R is a monovalent hydrocarbon group having a molecular weight of 250 to 500 and optionally containing a hydroxyl group).
A talc-containing propylene polymer composition, characterized by comprising 0.1 to 8% by weight. 2. The composition according to claim 1, wherein the crystalline propylene polymer is a propylene polymer selected from polypropylene, a propylene-ethylene block or random copolymer, and a propylene-ethylene-butene copolymer. . 3. The composition according to claim 2, wherein the crystalline propylene polymer is a propylene-ethylene block copolymer. 4. The crystalline propylene polymer is MFR1 to MFR1.
The composition of claim 1, which is a propylene polymer at 50 g / 10 minutes. 5. Talc has a specific surface area of 40,000 cm.
The composition according to claim 1, which is talc having a ratio of ² / g or more, a length of substantially 10 µm or less, an average particle size of 0.8 to 4 µm, and an average aspect ratio of 6 or more. 6. The composition according to claim 1, wherein the zinc salt is zinc behenate, zinc montanate or zinc hydroxystearate.