FILLER COMPOSITION

Abstract

A filler composition comprising fibrous basic magnesium sulfate particles and non-fibrous inorganic micro-particles having an average particle diameter in the range of 0.001 to 0.5 m in a ratio by weight in the range of 100:0.001 to 100:50, is used for providing a molded resin product which shows impact resistance and rigidity balanced at a high level.

Claims

1. A filler composition comprising fibrous basic magnesium sulfate particles and non-fibrous inorganic micro-particles having an average particle diameter in the range of 0.001 to 0.5 m, in a ratio by weight in the range of 100:0.001 to 100:50.

2. The filler composition of claim 1, wherein the non-fibrous inorganic micro-particles are non-fibrous inorganic micro-particles having an aspect ratio of not more than 2, which are particles of inorganic material selected from the group consisting of metal oxides, metal hydroxides and metal carbonates.

3. The filler composition of claim 1, wherein the non-fibrous inorganic micro-particles are non-fibrous inorganic micro-particles having an aspect ratio of not more than 2, which are particles of inorganic material selected from the group consisting of aluminum oxide, magnesium oxide, magnesium hydroxide and calcium carbonate.

4. The filler composition of claim 1, wherein the filler composition is for incorporation into a polyolefin resin.

Description

EXAMPLES

Reference Example

Preparation of Fibrous Basic Magnesium Sulfate Particles

[0033] 1.5 L of an aqueous fibrous basic magnesium sulfate slurry (solid content: 2.0 weight %, average fiber length: 15 m, average fiber diameter: 0.5 m, average aspect ratio: 30) was filtered under vacuum over a Bchner funnel to give 120 g of water-containing fibrous basic magnesium sulfate product (water content: 75 weight %).

[0034] The resulting water-containing fibrous basic magnesium sulfate product was processed in an extrusion granulator to give granules having a diameter of 2.4 mm and dried in a box dryer under heating at 160 C. for 24 hours to produce a basic magnesium sulfate powder (granular fibrous basic magnesium sulfate).

Comparison Example

[0035] 85 Weight parts of polypropylene resin [MFR (temp. 230 C., load 2.16 kg): 52 g/min.) and 15 weight parts of fibrous basic magnesium sulfate particles produced in Reference Example were mixed. The resulting mixture was melt-kneaded and extruded at a temperature of 230 C., rotation of screws: 90 r.p.m., by means of a double screw melt-kneading extruder (L/D=25, available from Imoto Seisakusho Co., Ltd.) to give a melt-kneaded product in the form of strands. The strands were cut to give pellets of a polypropylene resin composition containing the fibrous basic magnesium sulfate particles.

[0036] The resulting pellets of polypropylene resin composition was introduced into a small-sized injection molding machine (Handy Dry, manual-operated injection molding machine, available from Shinko Selbic, Co. Ltd.) to produce specimens (strips, 5 mm (width)2 mm(thickness)50 mm (length)).

[0037] The specimens were subjected to measurements of Izod impact strength and flexural modulus. The measurement results are set forth in Table 1.

[0038] The Izod impact strength was measured by means of an Izod impact tester (available from Maizu Tester Co., Ltd.).

[0039] The flexural modulus was measured by means of an electric measuring stand (MX-500N, Imada Corporation) and a digital force gauge (ZTA-500N, available from Imada Corporation) at a load rate of 10 mm/min., and distance between supports: 40 mm.

Example 1

[0040] Into 1.5 L of a fibrous basic magnesium sulfate slurry (solid content: 2.0 weight %, average fiber length: 15 m, average fiber diameter: 0.5 m, average aspect ratio: 30) was poured a slurry containing 0.45 g of alumina nano-particles (solid content: 10 weight %, average particle size: 31 nm, aspect ratio: 1.18), and the resulting mixture was stirred for 10 minutes and filtered under vacuum over a Bchner funnel to give a water-containing product containing fibrous basic magnesium sulfate and alumina particles. Thereafter, the resulting water-containing product was processed in the manner described in Reference Example to give a filler composition comprising fibrous basic magnesium sulfate and alumina nano-particles.

[0041] The procedures described in Comparison Example were repeated except for substituting the fibrous basic magnesium sulfate particles with the above-obtained filler composition to produce pellets of polypropylene resin composition containing the above-obtained filler composition.

[0042] The procedures of Comparison. Example were repeated using the pellets of a polypropylene resin composition to measure Izod impact resistance and flexural modulus.

[0043] The results of measurements are set forth in Table 1.

Example 2

[0044] Into 500 cc-volume of a plastic cylindrical vessel were poured 15 g of fibrous basic magnesium sulfate particles and 0.0225 g of high purity ultra-micro magnesium oxide particles (500 A, average diameter: 52 nm, aspect ratio: 1.21, available from Ube Material Industries, Ltd.). The resulting mixture was stirred under rotation for 10 minutes to give a filler composition comprising fibrous basic magnesium sulfate particles and high purity ultra-micro magnesium oxide particles.

[0045] The procedures described in Comparison Example were repeated except for substituting the fibrous basic magnesium sulfate particles with the above-obtained filler composition to produce pellets of polypropylene resin composition containing the above-obtained filler composition.

[0046] The procedures of Comparison Example were repeated using the pellets of a polypropylene resin composition to measure Izod impact resistance and flexural modulus.

[0047] The results of measurements are set forth in Table 1.

Example 3

[0048] Into 500 cc-volume of a plastic cylindrical vessel were poured 15 g of fibrous basic magnesium sulfate particles and 0.0225 g of high purity ultra-micro magnesium hydroxide particles (500 H, average diameter: 72 nm, aspect ratio: 1.20, available from Ube Material Industries, Ltd.). The resulting mixture was stirred under rotation for 10 minutes to give a filler composition comprising fibrous basic magnesium sulfate particles and high purity ultra-micro magnesium hydroxide particles.

[0049] The procedures described in Comparison Example were repeated except for substituting the fibrous basic magnesium sulfate particles with the above-obtained filler composition to produce pellets of polypropylene resin composition containing the above-obtained filler composition.

[0050] The procedures of Comparison Example were repeated using the pellets of a polypropylene resin composition to measure Izod impact resistance and flexural modulus.

[0051] The results of measurements are set forth in Table 1.

Example 4

[0052] Into 500 cc-volume of a plastic cylindrical vessel were poured 15 g of fibrous basic magnesium sulfate particles and 0.0225 g of high purity ultra-micro calcium carbonate particles (CS3N-A30, average diameter: 70 nm, aspect ratio: 1.35, available from Ube Material Industries, Ltd.). The resulting mixture was stirred under rotation for 10 minutes to give a filler composition comprising fibrous basic magnesium sulfate particles and high purity ultra-micro calcium carbonate particles.

[0053] The procedures described in Comparison. Example were repeated except for substituting the fibrous basic magnesium sulfate particles with the above-obtained filler composition to produce pellets of polypropylene resin composition containing the above-obtained filler composition.

[0054] The procedures of Comparison Example were repeated using the pellets of a polypropylene resin composition to measure Izod impact resistance and flexural modulus.

[0055] The results of measurements are set forth in Table 1.

TABLE-US-00001 TABLE 1 Izod impact Flexural modulus strength (kJ/m.sup.2) (GPa) Com. Ex. 2.1 2.8 Example 1 3.0 2.8 Example 2 2.4 2.9 Example 3 2.6 3.0 Example 4 2.7 2.7

[0056] The results of measurements set forth in. Table 1 indicate that molded products made from polyolefin resin compositions which comprises a filler composition of the invention show enhanced Izod impact strength as compared with molded products made from the polypropylene resin compositions containing only a polyolefin resin and fibrous basic magnesium sulfate particles, keeping the flexural modulus.