JPH0539380A - Talc-containing propylene polymer composition - Google Patents

Abstract

PURPOSE:To provide a talc-containing propylene polymer composition which has highly balanced rigidity and impact resistance and is reduced in mold contamination. CONSTITUTION:The title objective composition comprises 100 pts.wt. crystalline propylene polymer and 3-100 pts.wt. talc with a specific surface area of 37,000cm<2>/g or more, a length of substantially 15mum or less, an average size of 0.8-5mum and an average aspect ratio of 5 or more, and further comprises 0.1-8wt.% compound of formula (RCOO)nM (wherein R is a monovalent hydrocarbon group that may be hydroxylated and has a molecular weight of 250-500, (n) is the valency of metal M, and M is lithium, calcium, strontium or barium) based on the amount of the talc.

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 the cost of compounding rubber components, but also decreases rigidity, adding existing dispersants 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, a length of substantially 15 μm or less, and an average particle diameter of 0.8 to 5 μm.
And 3 to 100 parts by weight of talc having an average aspect ratio of 5 or more, and (RCOO) _n M (where R has a molecular weight of 2).
A monovalent hydrocarbon group optionally containing a hydroxy group of 50 to 500, n is a valence of metal M, and M is lithium, calcium, strontium or barium. ) A talc-containing propylene polymer composition, characterized in that the talc-containing propylene polymer composition comprises 0.1 to 8% by weight based on the talc amount of the compound represented by the formula (1).

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 derivatives (for example, acrylic acid or its ester, maleic anhydride, etc.), unsaturated aromatic compounds (for example, styrene, α-methylstyrene, etc.) and the like, such as block, random and graft.

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.

The 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 by 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 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.

For 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 talc raw stone (preferably produced in China with less metal impurity components) by, for example, an impact crusher or a micron mill type crusher, and further finely crushed by a micron mill or jet mill type crusher After that, it is manufactured by classifying and adjusting it with a cyclone or a micron separator.

The particle size of talc is a value 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 SS-100 manufactured by Shimadzu Corporation.
The length and aspect ratio are measured by a microscopic method or the like.

The (RCOO) _n M used in the present invention 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. Is. Specific examples include lithium behenate, lithium montanate, lithium hydroxystearate, calcium behenate, calcium montanate, calcium hydroxystearate, strontium behenate, barium behenate, barium montanate, barium hydroxystearate, and the like. .. Of these, calcium salts and barium salts are preferable, and calcium salts are particularly preferable. Such metal salts other than those used in the present invention do not exert the effect of suppressing mold contamination.

The mixing ratio of each of the above essential components is 3 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the crystalline propylene polymer, and 0.1 based on the amount of talc of the metal salt. ~ 8% by weight, preferably 0.3-5
% 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. On the other hand, if the amount of the metal salt is too small, the effect of improving the impact resistance is not exerted, while if it is too large, the effect of suppressing the mold contamination is not exerted, and the problem of bleeding from the molded product easily occurs.

In addition to these essential components, other additional components can be added within a range that does not significantly impair the effects of the present invention. For example, ethylene-propylene rubber,
Ethylene-butene rubber, low density polyethylene, medium and high density polyethylene, linear low density polyethylene, ultra low density polyethylene, styrene-butadiene-styrene rubber or hydrogenated product thereof, styrene-ethylene-butadiene-styrene rubber or The hydrogenated product and the like are good examples. Further, addition of a pigment is preferable in terms of improving commercial value. Specifically, as an organic pigment, a condensed azo pigment,
Isoindolinone-based, quinacridone-based, perinone-based, perylene-based, quinophthalone-based, anthraquinone-based, phthalocyanine-based, inorganic pigments include titanium oxide, titanium yellow, zinc white, iron black, carbon, rouge, ultramarine blue, etc. .. In addition, the following may be mentioned as examples of other additional components. That is, hindered phenol type,
Sulfur-based, phosphorus-based antioxidants, hindered amine-based, triazole-based, benzophenone-based, benzoate-based, nickel-based salicylic acid-based light stabilizers, antistatic agents, lubricants, peroxides, metal deactivators, organic And inorganic nucleating agents, antibacterial agents, optical brighteners, fillers other than essential components, for example, mica, glass fiber, barium sulfate, calcium carbonate, potassium titanate, inorganic such as nylon fiber,
Organic fillers are a good example.

The composition of the present invention can be manufactured by a conventional method. For example, a powdery propylene polymer is charged with the other two essential components of the present invention and, if necessary, other additional components, blended with a Henschel mixer, and then melted with a uniaxial or biaxial kneading extruder. Mix into pellets. The pellets are processed by an injection molding machine or the like to obtain a desired molded product. By mixing the metal salt component with the talc component in advance with a Henschel mixer or the like, the effect can be more effectively exhibited.

[0018]

【Example】

Examples 1 to 6 and Comparative Examples 1 to 7 MFR 10 g / 10 minutes, 100 parts by weight of a propylene-ethylene block copolymer having an ethylene content of 3% by weight, a specific surface area of 41,000 cm ² / g and a length of less than 10 μm 9
8.2% and 15% or less portion 100%, average particle size 3.
8 μm, talc having an average aspect ratio of 6 and metal salts represented by the following abbreviations were added in the amounts shown in Table 1, mixed with a Henschel mixer, and then heated at 230 ° C. with an extruder having a diameter of 30 mm.
And kneaded into pellets. The pellets are molded at 240 ° C. by an injection molding machine to have a length of 80 mm, a width of 10 mm,
A test piece having a thickness of 4 mm was molded. The bending elastic modulus (JIS-K7203 conformity) was measured using this test piece. Also, a sheet having a length of 120 mm, a width of 80 mm and a thickness of 20 mm is injection-molded under the same conditions, and the sheet has a diameter of 20 mm.
Energy required for destruction by dropping the dirt of
T) was measured.

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

(Metal salt used in the present invention) BL: Lithium behenate ML: Lithium montanate BC: Calcium behenate HSC: Calcium hydroxystearate HSB: Barium hydroxystearate (other metal salts) SC: Calcium stearate SM: Stearin Magnesium acid SZ: Zinc stearate SN: Sodium stearate

As a stabilizer, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (IR101
0) and tris (2,4-di-t-butylphenyl) phosphite (IR168), respectively.
In the compositions of 5 and Comparative Examples 1 to 6, 0.11 parts by weight each (based on 100 parts by weight of the propylene polymer), and in Examples 6 and Comparative Example 7, 0.13 parts by weight each ( (Added to the same weight part) and molded. The evaluation results are shown in Tables 1 and 2.

Comparative Examples 8 to 10 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. IR1010 and IR16 as stabilizers
8 was added to each 0.11 part by weight (based on 100 parts by weight of the propylene polymer) and molded. The evaluation results are shown in Tables 1 and 2.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

INDUSTRIAL APPLICABILITY The present invention has a remarkable effect that the balance between rigidity and impact resistance is improved and the mold contamination is suppressed by using the specified talc and the metal salt of the molecular weight and the metal species. It is an invention to be played. The effect of the present invention is particularly exerted effectively in an injection molded product, and specific examples of the molded product include interior and exterior parts of automobile bumpers, instrument panels, home appliances, and the like. Parts such as refrigerators, high-rigidity containers, food containers for microwave ovens, and injection molded products such as margarine and butter containers.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiko Ichikawa 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Petrochemical Co., Ltd. Yokkaichi Research Institute

Claims (1)

[Claims] 1. A crystalline propylene polymer 100 parts by weight,
Specific surface area of 37,000 cm²/ G or more, substantial length
15 μm or less, average particle size 0.8 to 5 μm, and average diameter
3 to 100 parts by weight of talc having a spectrum ratio of 5 or more, and
(RCOO) _nM (where R has a molecular weight of 250 to 50)
Monovalent hydrocarbons which may contain 0 hydroxy groups
Group, n is the valence of metal M, M is lithium, calcium,
Strontium or barium. ) Of the compound represented by
Characterized by 0.1 to 8% by weight based on the amount of talc
And a talc-containing propylene polymer composition.