JPH07227849A - Treatment of plastic waste material - Google Patents

Abstract

PURPOSE:To simply obtain a plastic molded product by utilizing a mixture of plastic waste materials. CONSTITUTION:A mixture of two or more kinds of plastic waste materials is ground to obtain ground matter with the max. particle diameter of 3 mm or less and a material containing 50wt.% or more of the ground matter is used as a main raw material. 30wt.% or less of a binder composed.of plastic having an m.p. lower than that of any plastic constituting the main raw material is mixed with 70wt.% or more of the main raw material and the resulting mixture is molded. By this constitution, a plastic molded product having the plastic ground matter dispersed therein without melting all of plastics constituting the main raw material and excellent in design effect is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating plastic waste material, more specifically, a plastic material which can be treated and molded as it is without selecting a mixture of two or more plastic waste materials having different melting temperatures. The present invention relates to a method for treating waste materials.

[0002]

As is well known, plastic products are food products,
It is used in large quantities in a wide range of fields such as clothing and packaging for various other fields, and various plastics such as vinyl chloride are used as the material. Most of the waste materials of these plastic products are discarded in a mixed state without being classified by type.

[0003]

On the other hand, even if the waste plastic material is reused, the various materials are mixed as described above, and the mixture cannot be immediately melt-processed. For example, the same type of polypropylene (PP) and polyethylene (P) as polyolefin (PO)
Even if there is no problem with the mixture of the two kinds because those such as E) are compatible, PP, vinyl chloride (PVC), PE
When PVC is mixed like PVC with
C causes thermal decomposition to generate HCl, which further decomposes into Cl, or is carbonized by high heat. As mentioned above, P
When the VC is carbonized, a general plastic processing machine such as an extruder, an injection machine, or a press machine is clogged, and long-term operation is impossible.

Further, since a mixture of PP and polyester (PET) or polystyrene (PS) is incompatible, even if it is simply melted, the appearance and physical properties are inferior, and it is handled by a general plastic processing machine. It is difficult and the workability is poor.

Therefore, these must be individually sorted, and this sorting operation is time-consuming and 100
% Sorting is almost impossible. Furthermore, the individually selected plastics must be melted at temperatures corresponding to the melting points of the materials, which makes handling of waste complicated and not only poor workability but also high cost. There is.

As a result of various studies, the inventor of the present invention has focused on the treatment of the above-mentioned conventional plastic waste materials, and has achieved a method capable of easily producing a useful plastic molded product without any sort treatment.

[0007]

According to the invention of claim 1, 2
A mixture of at least one kind of plastic waste material is pulverized to a main raw material so that a maximum diameter of 3 mm or less is contained at 50% by weight or more, and the main raw material is composed of 70% by weight or more of the main raw material. A plastic molded product in which a crushed plastic material is dispersed is obtained by mixing a binder made of plastic in an amount of 30% by weight or less without melting any of the plastics present and then molding.

According to the second aspect of the present invention, the plastic molded article according to the first aspect is obtained in which the binder is a plastic having a melting point lower than that of any of the plastics constituting the main raw material.

Further, in the invention of claim 3, the constitution is such that a plastic molded product is obtained by using a reactive plastic in which a binder reacts at room temperature or 100 ° C. or lower.

[0010]

The present invention has the above-mentioned constitution, and is a mixture of two or more kinds of plastic waste materials (hereinafter referred to as "A").
The term "PO" means a mixture of two or more of PO such as PP and PE, PS, PVC, PET, acrylonitrile butadiene styrene (ABS) and acrylonitrile styrene (AS).

As the plastic used as the binder (hereinafter referred to as B), a plastic having a melting point relatively lower than the melting point of the pulverized material A or a reactive plastic which reacts at room temperature is used. In addition, soft PVC, low density PE, etc. are used as the low melting point plastic.

When B is a plastic having a melting point lower than that of the pulverized product A, compatibility is not a particular problem. That is, A crushed product and B
Regardless of whether or not they are compatible with each other, if heat extrusion molding is performed at the melting point of B, the pulverized product of A does not melt and
It can be molded as a uniformly dispersed product in this case. In this case, B plays a role as an adhesive, and even if high temperature decomposable plastic is present in A, the melting point of B is low, so
Does not reach the decomposition temperature.

As the plastic which reacts at room temperature, for example, methyl methacrylate resin can be used. If B is a plastic that reacts at room temperature, then A
A three-dimensional polymerization reaction occurs between B and B, and there is no risk of A falling off, and a molded product having more excellent hardness and abrasion resistance can be obtained.

The pulverized product of the main raw material A of the present invention is a solid pulverized product similar to the inorganic filler generally used in plastic compositions. However, unlike the inorganic filler, it is a plastic and is therefore compatible with B. good. However, the particle size of A crushed product is 3m
When the content of m or more is 50% by weight or more, the molded product obtained from the composition cannot achieve uniform mixing of the pulverized product of A, and the particle size of 3 mm or more is compatible with B. Since there is a problem and there is a possibility that the pulverized product A is separated from the molded product and falls off, the pulverized product A having a maximum particle size of 3 mm or less is 50% by weight or more. Incidentally, since the pulverized product A is 70% by weight,
As for the obtained molded product, the pulverized product A is the same as the conventional inorganic filler.
The action and effect of adding a filler can be imparted to a molded product.

If the above composition is appropriately molded into a plate shape by an extrusion molding machine or the like to form a floor tile, etc., the uniformly dispersed property of A contributes to the floor tile having excellent hardness and abrasion resistance. Can be In addition, the obtained molded product can show a pattern in which black (or black gray) of A and transparent B are mixed, and a floor tile or the like having a rich design can be obtained.
Further, if the plate-like material is formed into a petri dish, a chemical resistant container can be obtained.

[0016]

EXAMPLES The present invention will be described in detail below with reference to examples. Example 1 Raw Material A: Sheet Vacuum Formed Product 50% by weight of finely pulverized product in tray (3% or less pulverized product; 5% or more pulverized product 5%) and acrylic resin signboard pulverized product (3% or less pulverized product 90%; Mixture of crushed product of 5 mm or more 2%) 50% by weight B: Soft PVC (plasticizer DOP 40% by weight, compounding powder)
1mm or less 100%, melting point 120 ° C)

Molding method A mixture of 85% by weight of A and 15% by weight of B is extruded by a 90 mm single extruder, and a plate-like material having a thickness of 3 mm is formed by a T-die (width of 1000 mm), and this is glazing with three rolls. And 450mm
It was cut into corners to obtain floor tiles. The extrusion temperature in this case is
Since the temperature was 140 ° C. or lower, only A did not melt, but only B melted, and it was a floor tile having hardness and abrasion resistance, and the colors of A and B had a flow pattern design.

Example 2 A: Sheet vacuum molded product tray PP finely pulverized product (pulverized product of 3 mm or less 90%; pulverized product of 5 mm or more 5%, melting temperature 250 ° C., carbon black 2% mixed product) B: low density PE, MI = 4
0; Finely pulverized product with a melting temperature of 180 ° C, particle size 3 mm or less 90%; 5
mm or more 10%)

Molding method A mixture of 80% by weight of A and 20% by weight of B is put in a 90 mm single extruder at an extrusion temperature of 180 ° C. or lower and a T-die of 800 mm width and 5 mm thickness.
A molded product of the plate-shaped product was obtained. Since the extrusion temperature was 180 ° C. or less, A did not melt and B worked as a strong adhesive and had high strength. Since the black A and the transparent B do not mix, the molded product has a pattern excellent in design. In addition, this molded product is compressed by compressed air according to the usual molding method.
It was a shallow dish with excellent chemical resistance that could be processed into a 40 mm dish-shaped shallow dish.

[0020]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to process a plastic waste material because it can be formed by crushing the plastic waste material as it is without any sort of selection, and mixing it with a plastic as a binder. Is easy and has excellent workability. Further, the crushed material of the plastic waste material is different from the inorganic filler in that it is well compatible with the plastic as the binder, and there is no possibility that the crushed material falls off from the molded product.

Further, the obtained molded product is obtained as a pulverized product of waste plastic material dispersed in the molded product, and forms a pattern in which the colors possessed by both are respectively expressed, and a molded product having an extremely excellent design. Obtainable.

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Claims (3)

[Claims] 1. A mixture of two or more plastic waste materials is crushed to obtain a main raw material having a maximum diameter of 3 mm or less in an amount of 50% by weight or more, and the main raw material is used in an amount of 70% by weight or more. A method for treating a plastic waste material, which comprises mixing a binder made of plastic in an amount of 30% by weight or less and molding the mixture without melting any of the plastics constituting the main raw material. 2. The method for treating plastic waste material according to claim 1, wherein the binder is a plastic having a melting point lower than that of any plastic constituting the main raw material. 3. The method for treating a plastic waste material according to claim 1, wherein the binder is a reactive plastic that reacts at room temperature or 100 ° C. or lower.