JPH0911237A - Reprocessing method of synthetic resin material with coating film - Google Patents

Abstract

(57) [Summary] [Objective] The purpose of the present invention is to make the coating film harmless regardless of the type of coating film or base resin without changing the processing conditions, and to have the same performance as the original synthetic resin waste material. It is possible to recycle materials, reduce running costs by simplifying equipment and omitting the number of steps, and to provide a method of reprocessing a synthetic resin material with a coating that can be reused for its original purpose. . [Structure] In the regeneration treatment method of the present invention, the synthetic resin waste material 1 having the coating film 2 is subjected to flame treatment to carbonize only the coating film 2, and then the flame-treated synthetic resin waste material 1 is roughly crushed. At the same time, the coarsely pulverized product 6 is melted and extruded to be re-raw material, and thereafter, the regenerated resin material pellets 11 are used to form the regenerated resin product 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reprocessing a synthetic resin material with a coating film, and in particular, a coating film is made harmless, and a material having the same performance as the discarded original synthetic resin material is reprocessed. It is about the method.

[0002]

2. Description of the Related Art Generally, a coated synthetic resin material (plastic) is discarded after being used as a product, but is reused for saving resources and preventing environmental pollution.
A melt filtration method, for example, has been proposed as a conventional technique for recycling (recycling) the coated synthetic resin waste material. That is, in this melt filtration method, a waste material pulverized product with a coating film is heated in an extruder to be melted, and a coating film of a thermoplastic resin of a base material in a liquid state and a thermosetting resin in a solid state is appropriately used. The raw material is reused by filtering and separating with a wire mesh (screen) having a large number of meshes. This is also used as the final finishing step of the coating film removing method described below.

There are various coating film removing methods for performing the pretreatment for recycling, and one of them is the blasting method.
This is a method in which the coating film is peeled and removed by impacting the coated surface of a synthetic resin waste material with various powders such as sand injected at high speed and high pressure, or a liquid such as water. This blast method is classified into a sand blast method, a plastic blast method, a baking soda blast method, a dry ice blast method, and a water jet blast method depending on the abrasive to be injected. In addition, there is a vibration compression method as a mechanical coating film removal method, in which a pulverized waste material is subjected to vibration compression, shearing, and surface polishing in a vibration compressor to remove the coating film, and then in the next step. The residual coating film is removed by applying impact, shear heat generation and polishing in a pin mill.

Further, in the chemical method for removing a coating film, a pulverized product of a waste material with a coating film is put into a coating film decomposing agent (water / ethanol / organic salt), and a thermosetting resin coating film is formed by using an organic salt ion as a catalyst. There is an alcohol / organic salt method that chemically decomposes and removes. Further, by the same chemical method, the pulverized waste material with coating film is pressurized and heated in water at 160 ° C to hydrolyze the thermosetting resin coating film without using a catalyst to lower the coating film. There is a method (Japanese Unexamined Patent Publication No. 6-134763) in which the material is made into a molecular weight and kneaded into the base resin.

[0005]

However, among the above-mentioned conventional regeneration treatment methods, the dissolution filtration method for removing the coating film is a single use without pretreatment (coating peeling and separation). The removal efficiency is poor, and the screen is quickly clogged, and the replacement frequency must be extremely high, which makes practical application difficult. Therefore, it can be said that it is better to utilize the dissolution filtration method as a final finishing step of other coating film removal methods. In addition, since various blasting methods remove the coating film by injecting an abrasive, it is common that it is difficult to remove the coating film of a complicated shape part such as a deep recess, the processing speed is slow, and there is a problem in productivity. there were. In addition, when moldings of various shapes are mixed, automation is also difficult. Furthermore, since the abrasives such as dry ice to be used including the dry ice blast method are expensive, there is a problem that they are not economically viable. Moreover, in the sandblasting method, the abrasive material is embedded in the base material of the molded product, which may hinder the re-production of the raw material.

On the other hand, among the conventional recycling methods, in the vibration compression method, it is necessary to individually optimize the setting of apparatus conditions depending on the properties of the coating film and the base resin, so that moldings of all kinds are mixed. It was difficult to deal with each under the circumstances. In addition, depending on the type of coating film, it may be difficult to remove the coating film. In addition, the alcohol / organic salt method, which is one of the chemical methods, requires a decomposing agent recovery process and the material of the target coating film is limited, resulting in high production costs and a narrow application range. There was a problem. In addition, the underwater pressure heating method has a problem that the process is complicated and the apparatus becomes large because a pressure vessel is required.

The present invention has been made in view of the above circumstances, and its purpose is to make the coating film harmless regardless of the type of coating film or base resin without changing treatment conditions. It is possible to recycle materials with the same performance as resin waste materials, reduce running costs by simplifying equipment and omitting the number of steps, and use synthetic film materials with a coating that can be reused for their original purposes. To provide a recycling method.

[0008]

In order to solve the above problems of the prior art, in the present invention, a synthetic resin material having a coating film is subjected to flame treatment to carbonize only the coating film, The flame-treated synthetic resin material is roughly crushed, and the coarsely crushed material is melted and extruded to be recycled as a raw material, after which a resin product is molded using the recycled raw material. .

In the regeneration treatment method of the present invention, the synthetic resin material having a coating film is carbonized only in the flame treatment step,
Coarse crushing is performed in the coarse crushing process, and then the resin product is molded in the productizing process through the melting, extruding process, and re-pelletizing process, so the carbonized coating becomes carbon black and becomes an additive material. This makes it harmless, retains the original material performance, and eliminates the need for disposal and collection processes of processing liquids, abrasives, etc., and makes it possible to obtain recycled synthetic resin products with high coating film removal efficiency.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

1 to 9 show an embodiment of a method for recycling a synthetic resin material with a coating film according to the present invention. In the figure, reference numeral 1 denotes a synthetic resin waste material having a coating film 2. The synthetic resin waste material 1 is composed of a resin product such as a bumper arranged in the front and rear portions of a vehicle body of an automobile. Polypropylene (PP) is mainly used as the base resin 3 of the waste synthetic resin material 1. A coating film 2 is formed on the surface of the synthetic resin waste material 1 by applying polyurethane paint or the like. Reference numeral 21 in the drawing denotes a recycled (recycled) resin product molded from the waste synthetic resin material 1.

The recycled resin product 21 of this embodiment is molded through the steps (1) to (5) shown in FIG. 1 in order.

(1) Flame Treatment Step First, the synthetic resin waste material 1 to be the recycled resin product 21 is arranged in relation to the flame radiating device 4 such as a gas burner. And
As shown in FIGS. 2 and 3, within a short time within a range in which heat of a high output flame is not transmitted from the flame radiating device 4 to the base resin 3 toward the surface of the coating film 2 attached to the synthetic resin waste material 1. To carbonize only the coating film 2. At this time, as the fuel of the flame radiating device (gas burner) 4 that radiates a flame, a combustible gas such as acetylene, argon, propane, or other fuel that generates a flame of high thermal power is used. Regarding the flame temperature, 1000 to 3000 ° C (preferably 200 ° C)
0 ° C). If the flame temperature is 1000 ° C or lower, the coating film 2 cannot be carbonized sufficiently, while if the flame temperature is 3000 ° C or higher, the base resin 3 is damaged. is there. Furthermore, the distance L between the nozzle 4a of the flame radiating device 4 and the coating film 2 is 50 to 30.
It is set to 0 mm (preferably 150 mm). The radiation time is preferably 0.1 to 2 seconds per radiation surface, and the damage to the base resin 3 can be reduced by such setting conditions.

(2) Coarse pulverizing step Next, the flame-treated synthetic resin waste material 1 obtained through this flame treating step is sent to the coarse pulverizing step and charged into the pulverizer 5 as shown in FIG. Then, the synthetic resin waste material 1 is crushed by the crusher 5 to a particle size of 1 to 10 mm (preferably 3 to 10 mm).
When roughly crushed to a size of 5 mm, a roughly crushed product 6 is produced. If the particle size of the coarsely pulverized product 6 is 10 mm or more, it takes a long time to melt the coarsely pulverized product 6, which is not suitable.

(3) Melting / Extruding Step The coarsely pulverized material 6 sent from the coarsely pulverizing step is put into the melting / extruding machine 7 shown in FIG. 5, and the coarsely pulverized material 6 melted by the extruder 7 is shaped into a thin rod. Strands (hundreds to thousands of filaments bundled with a binder) 8 are processed and molded. At this point, the carbonized coating film 2 is a powder having a particle size of about 10 μm that does not affect the material performance due to coarse pulverization and melt-kneading, and has an affinity with the base resin 3 because it is carbon. Is in a certain state. Further, at the time of extrusion, by using the screen 9 as shown in FIG. 6, the coating film 2a remaining without being carbonized can be removed. In this case, since most of the coating film 2 is carbonized, it is not necessary to replace the screen more frequently than when the screen 9 is used alone.

(4) Re-pelletizing Step (Re-Raw Materializing Step) Next, as shown in FIG. 7, the cooled strands 8 sent from the melting / extruding step are charged into the raw material manufacturing apparatus 10 and this manufacturing is performed. The raw material is re-produced by the apparatus 10 to produce pellets 11 of the molding material granulated into a prismatic shape. (5) Productization Step After that, as shown in FIG. 8, the obtained pellets 11 are put into an injection molding machine 12, and the pellets 11 are heated and melted while being pressed into a cavity of a closed mold 13. Inject and fill to solidify or cure. Then, if it is taken out of the mold 13 as a bumper molded product, a recycled resin product 21 as shown in FIG. 9 is molded from the synthetic resin waste material 1. This recycled resin product 21 may be basically the same as the one before it is turned into the original waste material. For example, by treating the bumper waste material with the coating film by the method of this embodiment, there is no problem in performance again. Bumpers can be produced.

In the regeneration treatment method of this embodiment, specifically, a polypropylene bumper having a urethane resin coating film was subjected to flame treatment. As for the processing conditions, the flame temperature is 1650 ° C., and the radiation distance (distance between the tip of the nozzle 4a and the surface of the coating film 2) L is set to about 150 mm. Substrate, to evaluate the effect of flame treatment,
Prepare a bumper with the same coating material and a bumper with the same base material and no coating, treat these in the exact same process after flame treatment, and after molding into a test piece, Each physical property was evaluated and compared. The results are shown in Table 1 below.

[0018]

[Table 1]

As is apparent from Table 1, it is understood that the flame-treated product has higher physical properties than the non-treated product. In particular, it can be seen that it has excellent elongation and impact resistance. Further, it is almost the same as that without the coating film, and it can be judged that the effect of the flame treatment is exhibited.

The embodiment of the present invention has been described above.
The present invention is not limited to the embodiments described above, and various modifications can be made based on the technical idea of the present invention.

For example, in the above-mentioned embodiments, the bumper 1 was explained as the resin product to be recycled, but it goes without saying that the present invention can be applied to other resin products such as instrument panels for automobiles.

[0022]

As described above, in the method for regenerating a coated synthetic resin material according to the present invention, a flame treatment is applied to the coated synthetic resin material to carbonize only the coating, and then the flame is applied. Since the processed synthetic resin material is roughly crushed, the coarsely crushed product is melted and extruded to be recycled as a raw material, and then a resin product is molded using the recycled raw material. In addition, the coating film can be made harmless as an additive to reduce deterioration of physical properties, and can be reused for its original purpose. Moreover, since the flame-treated coating film becomes black due to carbonization, it is possible to eliminate the spot pattern on the material surface due to mixing of the coating film, and it is possible to obtain a recycled resin product having a good appearance.

Further, in the regeneration treatment method of the present invention, the solvent and the abrasive are not used, and only the flame is used in the open treatment, so that the disposal and recovery steps of the treatment liquid and the abrasive can be omitted. In addition, it is possible to simplify equipment and processing steps, reduce running costs, and improve productivity by continuous processing. In addition, carbonization of the coating film brings about a state similar to that of adding carbon black, so that weather resistance can be increased and conductivity can also be added.

Further, in the regeneration treatment method of the present invention, unlike the other coating film removing methods, only the coating film is carbonized by the flame, so that the coating film tank and the processing liquid generated during the removal of the coating film are treated. It is possible to eliminate waste liquids and wastes such as abrasives, and also to carbonize together with the coating without removing the resin stickers attached to the waste material coated surface, thus eliminating extra steps. Moreover, according to the regeneration treatment method of the present invention, treatment can be performed without changing treatment conditions and regardless of the type of coating film or base resin.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a process of molding a recycled resin product from a synthetic resin waste material by a method for recycling a coated resin material according to an embodiment of the present invention.

FIG. 2 is a perspective view conceptually showing a state where the coating film of the synthetic resin waste material is subjected to flame treatment in the flame treatment step in FIG.

FIG. 3 is a cross-sectional view showing a waste synthetic resin material in FIG.

FIG. 4 is a conceptual diagram showing a state in which a flame-treated synthetic resin waste material is roughly crushed in the coarse crushing step in FIG. 1.

5 is a conceptual diagram showing a state in which a strand is processed and formed from a coarsely pulverized material in the melting / extruding step in FIG.

FIG. 6 is a conceptual diagram showing a state where a coating film remaining without being carbonized is removed by a screen in the melting / extruding step.

FIG. 7 is a conceptual diagram showing a state in which pellets are produced from strands in the re-pelletizing step in FIG.

FIG. 8 is a conceptual diagram showing a state in which pellets are pressure-injected and filled into a cavity of a mold in the production process of FIG.

9 is a perspective view showing a recycled resin product manufactured through each step in FIG. 1. FIG.

[Explanation of symbols]

 1 Synthetic Resin Waste Material 2 Coating Film 3 Base Resin 4 Flame Emission Device 5 Crusher 6 Coarse Crushed Material 7 Melt / Extruder 8 Strand 10 Raw Material Manufacturing Equipment 11 Pellet 12 Injection Molding Machine 13 Mold 21 Recycled Resin Product

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29B 13/10 B09B 5/00 ZABQ // B29K 105: 26

Claims (3)

[Claims] 1. A synthetic resin material having a coating film is subjected to a flame treatment to carbonize only the coating film, and then the flame-treated synthetic resin material is coarsely crushed, while the coarsely pulverized product is melted. A method of reprocessing a synthetic resin material with a coating, which comprises subjecting the resin material to a raw material by extrusion, and then molding a resin product using the resin material that has been recycled. 2. A flame temperature of 1 in the flame treatment.
The method for regenerating a synthetic resin material with a coating according to claim 1, wherein a high thermal power of 000 to 3000 ° C is radiated to the coating. 3. Regeneration of a synthetic resin material with a coating according to claim 1, wherein in the flame treatment, a flame is emitted to the coating in a short time of 0.1 to 2 seconds. Processing method.