JP3096374B2 - Mixed granulated product of synthetic resin powder and filler and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granulated mixture of a synthetic resin powder and a filler and a method for producing the same.

[0002]

2. Description of the Related Art When modifying the properties of a resin by mixing an inorganic filler into a synthetic resin, a resin powder or a pellet and a filler powder are used alone as raw materials, or both are mixed in advance, and then directly into a molding machine. Is known. In this case, since the filler is a powder, a bridging phenomenon (so-called shelving) or poor penetration into the screw occurs in the hopper of the molding machine, which causes problems such as a reduction in productivity and a variation in quality.

[0003] Therefore, a method in which a resin pellet and a granulated filler are used alone, or a mixture of the two is supplied in advance to a molding machine (JP-A-51-90336). There has been proposed a method of obtaining a mixture of a resin and a filler by stirring the resin at a high speed to soften or melt the resin.

[0004]

However, in the former method, the filler after molding does not disperse well in the resin as when it is used as a powder, and is liable to cause quality deterioration. Tends to occur. In the latter case, depending on the type of resin or filler,
Due to the heat history and mechanical shearing, there are problems such as deterioration and eventually deterioration in quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide a granular material having excellent handleability and workability, to provide a resin with high dispersibility similar to powder, It is an object of the present invention to provide a mixed granulated product of a synthetic resin powder and a filler and a method for producing the same, which can obtain a resin molded product having a stable quality by eliminating the variation of the above.

[0006]

The present invention SUMMARY OF] has been made for achieving the above object, polypropylene, nylon
, Polystyrene, polyvinyl chloride
And one kind of synthetic resin powder and powdery inorganic filler,
A granulated product obtained by mixing and granulating the synthetic resin powder without softening or melting, wherein the particle size of the granulated product is 0.1.
A mixed granulated product of a synthetic resin powder and a filler, which is 1 to 5 mm.

[0007] Since the granulated product is obtained by granulating the synthetic resin powder without softening or melting, the granulated product is not subjected to heat history and mechanical shearing, and is not deteriorated or deteriorated in quality. Never wake up. If the particle size of the granulated material is less than 0.1 mm, sufficient fluidity cannot be obtained and it is difficult to handle. If the particle size exceeds 5 mm, the dispersibility at the time of resin molding becomes poor. It is important that the diameter be in the range of 0.1 to 5 mm.

The above-mentioned granulated product is prepared by mixing a synthetic resin powder and a powdered inorganic filler in advance, adding water or an organic solvent or a mixed solution of both as a dispersion medium, and granulating with a stirring granulator. It can be obtained by drying. In addition, it is also possible to mix | blend an additive as needed.

The synthetic resin powder used in the present invention is heat-resistant.
Powder of plastic resin, polypropylene, nylon,
At least one selected from polystyrene and polyvinyl chloride
Kind of synthetic resin powder. The particle size of the powder is 100 μm or less.

Examples of the powdery inorganic filler include:
Powders such as titanium oxide, silica, talc, and carbon black can be used, and the type is not particularly limited.
The particle size of the powder is 100 μm or less. The mixing ratio of the synthetic resin powder and the powdery inorganic filler can be set as required, and is not particularly limited.

In the method of the present invention, in addition to using water as a dispersion medium, an organic solvent and a mixed solution of both can be used. Organic solvents that are removed by drying and do not remain in the granulated material include methanol, ethanol,
Diethyl ether, benzene, benzene, toluene and the like are used. Drying cost can be reduced by using a material having a relatively low boiling point. When a hydrophobic inorganic filler or the like is used, an organic solvent is used or a mixed solution of water and an organic solvent is used. The mixing ratio of water and the organic solvent will be determined based on the viewpoints of ensuring granulation properties, reducing drying costs, reducing organic solvent costs, and the like. Organic solvents are
After granulation, it can be collected and reused.

[0012]

Embodiments will be described below with reference to embodiments. Polypropylene used as synthetic resin powder (hereinafter referred to as PP)
Means that the melt flow index (MFI) according to JIS K 7116 is 9.05 g / 10 min, and JIS K 7116
The tensile strength, flexural strength and flexural modulus measured according to JIS K 113 and JIS K 7116 are 3.10, respectively.
It is a powder having an average particle diameter of about 50 μm with PP of 3.82 and 135 kgf / mm ² .

Titanium oxide is used as the inorganic filler, rutile type powder having an average particle diameter of 0.3 μm is used as the titanium oxide powder, and potassium titanate whisker (hereinafter referred to as PTW) has an average fiber length of 20 μm. .5 μm,
The fiber diameter was 0.5 μm.

[0014]

Example 1 PP powder: titanium oxide powder = 70: 30 w
The mixture was mixed well at a mixing ratio of t%, 5 kg of this mixture was put into a stirring granulator (Henschel mixer), 1.5 liter of water was added, and the mixture was granulated at 1,000 rpm for 5 minutes at room temperature. Then, it was dried with a fluidized drier to obtain a granulated product having a particle size shown in Table 1. The granulated product was supplied to an injection molding machine equipped with a vent, and after a test piece was molded, each physical property was measured. Table 2 shows the results
Was as shown in FIG.

[0015]

Example 2 PP powder: PTW = 70: 30 wt% was mixed well, 5 kg of this mixture was put into a stirring granulator (Henschel mixer), and water: methanol = 1: 1.
After adding 2.3 liters of the mixed solution of Example 1, 1000 rpm
At 5 rpm for 5 minutes. Then, it was dried with a fluidized drier to obtain a granulated product having a particle size shown in Table 1. The granulated product was supplied to a vented injection molding machine in the same manner as in Example 1, and after the test piece was molded, each physical property was measured. The results were as shown in Table 2.

[0016]

[Comparative Example 1] PP powder: titanium oxide granulated product = 70:30
The mixture was obtained by mixing at a blending ratio of wt% for 5 minutes in a V-type blender. This mixture was supplied to a vented injection molding machine in the same manner as in Example 1, and after the test piece was molded, each physical property was measured.
The results were as shown in Table 2. The titanium oxide granules were obtained by adding 3 kg of titanium oxide powder to a Henschel mixer, adding 0.6 liter of water, granulating at 800 rpm for 3 minutes, and drying with a fluidized drier. Yes, and Table 1 shows the particle size.

[0017]

COMPARATIVE EXAMPLE 2 PP powder: PTW = 70: 30 wt% was mixed at a mixing ratio, 5 kg of this mixture was put into a Henschel mixer, and the temperature in the tank was reduced to 1185 rpm for about 30 minutes under a nitrogen blanket until the temperature reached 185 ° C. Stir at speed to melt the polypropylene and then cool while mixing
The mixture was stirred at 00 rpm to obtain a mixture of PP powder and PTW (Table 1). This was supplied to a vented injection molding machine in the same manner as in Example 1, and after the test piece was molded, each physical property was measured. The results were as shown in Table 2.

[0018]

[Table 1]

[0019]

[Table 2]

The measuring methods in Table 2 are as follows. [Method of Measuring Mixing Ratio of Filler] A test piece was burned for 2 hours in an electric muffle furnace at 500 ° C., and the remaining white powder was weighed as a filler to calculate a mixing ratio.

[Strength measuring method] The tensile test and the bending test
It was measured according to JIS K 7113 and JIS K 7116. In addition, the preparation of the test piece was performed using an injection molding machine with a vent (screw diameter: 25 mm, nozzle temperature: 220 ° C.).
Was carried out.

[Method of measuring average fiber length after injection molding of PTW] In the same manner as in the method of measuring the compounding ratio, the resin content of the test piece was burned, and the remaining PTW was measured for fiber length by an image analyzer.

[Method of Measuring and Evaluating Dispersibility] A test piece was sliced into a film having a thickness of 50 ± 10 μm and photographed with a soft X-ray apparatus.
X), and those without aggregates were evaluated as good, and those with aggregates were evaluated as poor. The maximum diameter of the aggregates of the defective ones was about 50 μm.

[0024]

Since the granulated product of the present invention is a granulated product, it can be stably supplied without causing a shelving phenomenon in a molding machine hopper when compounded with a resin, and has good workability. Since the granules are mixed at a predetermined compounding ratio, the dispersion of the compounding ratio after molding is drastically reduced. In the production, the synthetic resin powder is not softened or melted, and the resin or filler is not subjected to heat history or shearing, so that granulation can be performed without deterioration, and a stirring granulator using water or an organic solvent as a dispersion medium. The solvent can be recovered because the granulation is carried out. Further, since water or an organic solvent is used, there is an advantage that it can be applied to both hydrophilic and hydrophobic materials. The granulated material has a dispersibility comparable to that of powder, and has effects such as improvement in efficiency of injection molding and stabilization of quality.

Claims (2)

(57) [Claims] 1. Polypropylene, nylon, polystyrene
Down, and at least one synthetic resin powder and powdered inorganic filler selected from polyvinyl chloride, a granulated product obtained by granulation is mixed at not soften or melt the synthetic resin powder, A mixed granulated product of a synthetic resin powder and a filler, wherein the granulated product has a particle size of 0.1 to 5 mm. 2. A method comprising mixing a synthetic resin powder and a powdery inorganic filler in advance, adding water or an organic solvent or a mixed solution of both as a dispersion medium, granulating with a stirring granulator, and drying. A method for producing a mixed granulated product of a synthetic resin powder and a filler according to claim 1.