JPS6286037A - Inorganic filler-containing polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. having well-balanced physical properties with respect to rigidity, resistance to impact and heat, surface properties, etc., by blending a polyolefin with a surface-treating agent together with an inorg. filler treated or crushed with a drying or semidrying crusher. CONSTITUTION:A polyolefin resin compsn. contains a surface-treating agent together with 5-50wt% inorg. filler treated or crushed with a drying or semidrying crusher. In the above description, it is preferred that the crusher is an air jet crusher, said air jet crusher is a fluidized bed type jet crusher and the inorg. filler is talc. Examples of the polyolefin resin to be used are alpha-olefin homopolymers, copolymers of at least two alpha-olefins and mixtures of the polymers. Pref. the inorg-filler has an average particle size of 10mu or below after treatment from the viewpoints of uniformity in treatment, compatibility with the resin and the balance of the physical properties of the resin compsn.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an inorganic filler-containing polyolefin resin composition, and more specifically, an inorganic filler surface-treated by a specific method is blended with a polyolefin resin to improve rigidity, stiffness,
The present invention relates to a resin composition with an excellent balance of physical properties such as impact resistance, heat resistance, and surface properties.

[Conventional technology]

Blending various inorganic fillers into polyolefins to improve rigidity, heat resistance, etc. has been widely practiced for a long time.In particular, the surface of inorganic fillers is treated with various treatment agents to improve affinity and dispersibility with polyolefins. It is also widely known that the physical property balance between rigidity and impact resistance can be further improved by improving the properties.

As a method for surface modification of inorganic fillers, the inorganic filler and various surface treatment agents, or various solvents as needed, are placed in a Henschel mixer or the like and stirred at room temperature or high temperature. Physical surface treatment methods are well known.

[Problem that the invention seeks to solve]

However, although various physical properties such as rigidity, impact resistance, and heat resistance of polyolefin resin compositions containing inorganic fillers that have been surface-treated by such methods are improved to some extent, they are still not satisfactory, and Depending on the type of filler, it may have no effect at all or may even reduce rigidity.

In addition, since the surface treatment process is complicated, there are problems in terms of productivity, safety, etc., and there are also disadvantages in that the cost is high.

An object of the present invention is to provide an inorganic filler-containing polyolefin resin composition that solves the above-mentioned drawbacks.

[Means to solve the problem]

In order to achieve the above object, the present inventors have made extensive studies and have finally completed the present invention.

That is, the present invention is a polyolefin resin composition containing 5 to 50% by weight of an inorganic filler, in which the inorganic filler is pulverized or treated together with a surface treatment agent using a dry or semi-dry pulverizer. be.

A preferred embodiment of the present invention is that the pulverizer is a jet pulverizer, and the jet pulverizer is a fluidized bed jet pulverizer, and further includes:
The inorganic filler is talc.

The polyolefin resin used in the present invention is a homopolymer of α-olefin such as ethylene or propylene, or
These are copolymers of N or more, and mixtures of these polymers.

Inorganic fillers used in the present invention include, for example, calcium oxide, magnesium oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium sulfate, barium sulfate, and calcium sulfite. , talc, mica, clay, dolomite, basic magnesium carbonate, glass, etc. Among them, use of talc is most preferred.

The particle size of the inorganic filler used in the present invention varies depending on its type and amount used, but it depends on the uniformity of treatment, compatibility with the resin, and balance of physical properties in the resin composition, etc.
The average particle diameter after treatment is preferably 10 μm or less, more preferably 8 μm or less.

In the present invention, the content of the inorganic filler is preferably 5 to 50% by weight; if it is less than 5% by weight, the effect of improving the stiffness, heat resistance, and surface properties of the resulting composition is small; if it exceeds 50% by weight, Both cases are unfavorable because the impact resistance decreases.

Examples of the surface treatment agent used in the present invention include organic silane-based or titanium-based coupling agents, various surfactants, silicone oils, various silane compounds, metal soaps, higher alcohols, polyolefins, and unsaturated carboxylic acid-modified polyolefins. It will be done.

The ratio of the inorganic filler to the surface treatment agent is usually preferably 0.01 to 5 parts by weight per 100 parts by weight of the inorganic filler. That is, it is preferably 0.01 parts by weight or more in order to increase the surface treatment effect, and 5 parts by weight or less in terms of improving the balance of physical properties such as rigidity, impact resistance, heat resistance, and surface properties of the resulting resin composition. is preferred. If the amount exceeds 5 parts by weight, not only the rigidity, impact resistance, etc. may deteriorate, but also the cost will increase, which is not preferable in any case.

For surface treatment of these inorganic fillers, the inorganic filler and surface treatment agent are premixed or separately fed to a pulverizer.
This can be done by performing surface treatment at the same time as crushing.

Here, as the above-mentioned pulverizer, it is sufficient that it can be finely pulverized or finely pulverized in a dry or semi-dry type, for example,
Examples of pulverizers include micron mills, jet stream pulverizers, ball mills, micronizers, turbo mills, and atomizers, but from the viewpoint of pulverization efficiency, grinding time, and workability,
Jet stream crushers such as macronizer type, reductionizer type, impact type, opposed type, and fluidized bed type are preferred;
Among these, a fluidized bed type jet pulverizer is particularly preferable because surface treatment can be performed more uniformly.

In the present invention, antioxidants, lubricants, ultraviolet absorbers,
Various additives such as ultraviolet stabilizers, heat stabilizers, antistatic agents, nucleating agents, organic and inorganic pigments may be added alone or in combination. Examples of these various additives include those commonly added to polyolefin resins, and they may be used within a range that does not significantly impair the effects of the present invention. Further, if necessary, resins other than the polyolefin resin used in the present invention can also be used in combination.

The resin composition of the present invention is usually obtained by premixing the components in a Henschel mixer or the like, and then melt-kneading them in a l-shaft or two-sleeved extruder to form pellets.
The pellets can be molded into a product by a molding method such as extrusion molding, injection molding, rotational molding, compression molding, or the like.

〔Effect of the invention〕

The inorganic filler-containing polyolefin resin composition according to the present invention has an excellent balance of physical properties such as rigidity, impact resistance, heat resistance, and surface properties, and is therefore suitable for industrial parts such as automobile parts and home appliance parts.

〔Example〕

EXAMPLES The present invention will be specifically explained below using Examples.

In the following description, melt flow index (lv
ll') is ASTM D 1238, flexural modulus is ASTM D-190, Izod impact strength is ASTM MD-256, overheating distortion temperature is ASTM
Measured according to MD-648.

Moreover, the surface characteristics were visually determined by the following method.

Sample 80x160x2mm grained flat plate (
(Colored with 1 part by weight of red iron: carbon black = 5:l pigment) Grain shape Convex area: approx. 3 +u+' elliptical depth: approx. 0
．． One shoulder measurement method Using a pencil scratch test device specified in JIS-K 5401, a brass frame with a tip of 0.5R was attached instead of a pencil, and scratches were made on the surface of the sample at a load of 1.0 to 9. and the extent of the injury was determined.

Judgment criteria ◎: No scratches observed ○: 〃 Hardly observed △: 〃 Slightly recognized Mica has a normal particle size distribution of shoulders: 15 μl in terms of average particle size Calcium carbonate: Heavy calcium carbonate with an average particle size of 3 μm (2) Grinding machine and grinding conditions Grinding machine; Fluidized bed Type counter jet mill (Model 400AFG manufactured by West German Alpine) Grinding conditions Air volume: 1 6 2 (1 + 3/Hr Grinding pressure: 6 to 9/am" (using compressed air) Classifier rotation speed: 400
0 rpm (3) Surface treatment agent and amount added are shown in Table 1.

(4) Treatment method The raw materials described in (1) above and the surface treatment agent described in (3) are
2) Grinding and surface treatment were performed while separately feeding the materials into the grinder described above.

Examples and Comparative Examples Contains ethylene ff16.8% by weight, MI 89/1 (]
+in ethylene/propylene block copolymer (pp
), density 0.963, M I 89/ 10o+in
high-density polyethylene (PE), inorganic filler AA-
Add a small amount of antioxidant, metal soap, etc. to L in the ratio shown in Tables 2 to 4, mix with a Henschel mixer, and then
Pelletization was performed at 30°C using a 40zxφl screw extruder, and the resulting pellets were molded into predetermined test pieces using an injection molding machine at 230°C, and various physical properties were measured.

The results obtained are shown in Tables 2-4.

As is clear from Tables 2 to 4 below, it can be seen that only the cases according to the present invention have good bending elasticity, impact strength, thermal deformation resistance, and surface properties.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd. Representative Patent Attorney: Nobuaki Sakaguchi (and 1 other person)

Claims (4)

[Claims] (1) A polyolefin resin composition containing 5 to 50% by weight of an inorganic filler, characterized in that the inorganic filler is pulverized or treated together with a surface treatment agent using a dry or semi-dry pulverizer. Polyolefin resin composition. (2) The inorganic filler-containing polyolefin resin composition according to claim 1, wherein the pulverizer is a jet stream type pulverizer. (3) The inorganic filler-containing polyolefin resin composition according to claim 2, wherein the jet stream type crusher is a fluidized bed type jet crusher. (4) Claim 3 in which the inorganic filler is talc
The inorganic filler-containing polyolefin resin composition described in 1.