JPH04334408A - Regenerating process for thermoplastic resin part - Google Patents

Abstract

PURPOSE:To provide the regenerating process for a thermoplastic resin part in which a defective thermoplastic part coated with a thermoplastic resin coating material can be regenerated in the state of being ready for reuse. CONSTITUTION:First, a colored bumper 1 (thermoplastic resin part) coated with a top coating material 4 (thermoplastic coating material) is crushed into pieces of 5mm or smaller as the longest dimension of pieces, and then said polypropylene 1A for coating (recycling material) is mixed into an intermediate layer 11 of a glass long fiber reinforced stampable sheet 10 (a thermoplastic agent for regeneration) containing glass fiber mat 13 (glass fiber) of 10wt.% mass and reused.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for recycling thermoplastic resin parts used when reusing thermoplastic resin parts used, for example, in automobile bumpers, and particularly relates to a method for recycling thermoplastic resin parts used in automobile bumpers. The present invention relates to a method for recycling thermoplastic resin parts coated with .

0002

2. Description of the Related Art Conventionally, when defects such as scratches occur in parts made of thermoplastic resin such as polypropylene, such as unpainted bumpers for automobiles, in the manufacturing process 51, as shown in FIG. In step 52, the defective unpainted bumper is finely crushed in a crusher, and in step 53, the crushed material is mixed with virgin material (thermoplastic resin material) to make it reusable, and in step 54, the bumper is reused by an injection molding machine. I was trying to mold it.

0003

[Problems to be Solved by the Invention] However, when trying to reuse defective thermoplastic resin parts painted with paint made of thermosetting resin, such as colored bumpers for automobiles, by the above-mentioned conventional recycling method, Since thermoplastic resin and thermosetting resin, which have low compatibility and affinity between them, are mixed, it is expected that the separation of microphases will lead to a decrease in strength and poor appearance. However, there is a problem in that it is difficult to reuse defective colored bumpers, and it has been a conventional problem to solve these problems.

0004

OBJECT OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to recover defective thermoplastic resin parts coated with paint made of thermosetting resin in a state that can withstand reuse. It is an object of the present invention to provide a method for recycling thermoplastic resin parts that can be recycled.

[0005]

[Means for Solving the Problems] This invention provides, when reusing thermoplastic resin parts coated with a thermosetting resin paint, the coated thermoplastic resin parts with a length of 5 mm or less at the longest dimension. After pulverizing the recycled material into crushed pieces, the recycled material is reduced to a mass percentage of 10wt.
It is characterized by a structure in which it is mixed into a recycled thermoplastic resin material containing % or more of glass fiber for reuse, and solves the above-mentioned conventional problems in the structure of a method for recycling such thermoplastic resin parts. It is used as a means to do so.

[0006] When seeking a recycled product with higher strength, the mass percentage of the recycled material obtained by crushing thermoplastic resin parts mixed into the thermoplastic resin material for recycling should not exceed 50 wt%. It is desirable to do so.

[0007]

Effect of the Invention In the method for recycling thermoplastic resin parts according to the present invention, thermoplastic resin parts coated with a thermosetting resin paint are crushed into fragments such as ellipsoids and spheres whose longest dimension is 5 mm or less. When this recycled material is mixed into a recycled thermoplastic resin material containing glass fiber with a mass percentage exceeding 10 wt%, as shown in the circle in FIG. 10, the thermosetting resin in the recycled material 1A The unreacted hydroxyl groups and carbonyl groups of the paint form strong hydrogen bonds with the hydroxyl groups on the surface of the glass fiber 13 on the side of the recycled thermoplastic resin material, thereby forming a binder between the glass fiber 13 and the thermoplastic resin 12. This will lead to the production of recycled products that can withstand reuse.
Furthermore, it can be expected that the overall strength will be several percent higher than that of virgin products.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the drawings.

FIGS. 1 to 5 show an embodiment of a method for recycling thermoplastic resin parts according to the present invention.

FIG. 2 shows a colored bumper as a thermoplastic resin part coated with a thermosetting resin paint.
In this case, the colored bumper 1, as shown in FIG.
A bumper body 2 made of polypropylene having high rigidity is coated with an acrylic/melamine-based top coat 4 as a thermosetting resin paint via an undercoat 3.

As shown in FIG. 1, if the colored bumper 1 is defective due to defects such as scratches in the manufacturing process A, the defective colored bumper is first crushed by a crusher in the process B. 1 into crushed pieces such as ellipsoids and spheres whose longest dimension is 5 mm or less. Next, in this example, the coated polypropylene (recycled material) 1A obtained in step B was transferred to step C.
It is mixed into the intermediate layer of a long glass fiber reinforced stampable sheet at a mass percentage of 20 wt% and recycled,
In step D, a long glass fiber reinforced stampable sheet 10 shown in FIG. 5 is formed. As shown in FIG. 4, this long glass fiber reinforced stampable sheet 10 is formed into a glass fiber mat when melt polypropylene 12 extruded from an extruder 21 of a stamping molding device 20 passes through a heating section 22 and a cooling section 23. 13 and a polypropylene mat 14, which are successively sandwiched, and the coated polypropylene 1A is mixed into the melt polypropylene 12 to form the intermediate layer 11.

In order to confirm the performance of the long glass fiber reinforced stampable sheet 10 thus obtained, the flexural modulus Ea, glass fiber content and recycled material of this long glass fiber reinforced stampable sheet 10 (recycled product) were determined. When the relationship with the mixing rate was investigated, the results shown in FIG. 6 were obtained. As can be seen from Figure 6, the glass fiber content is 10
wt% or more and the recycled material mixing rate does not exceed 50 wt%, the flexural modulus Ea of the long glass fiber reinforced stampable sheet 10 is the same as the long glass fiber reinforced stampable sheet (not mixed with the coated polypropylene 1A). It was confirmed that the bending elastic modulus was higher than the bending elastic modulus Ea of the virgin product), and it was confirmed that the bending elastic modulus could be made excellent.

Furthermore, when the glass fiber content was 40 wt% and the recycled material content was 20 wt%, the longest dimension of the crushed pieces of coated polypropylene 1A was varied and the relationship between the flexural modulus and dimension was investigated. The results shown in FIG. 7 were obtained. As can be seen from FIG. 7, it was confirmed that when the size was 5 mm or less, the mixing state was good and the flexural modulus showed a high value.

FIG. 8 shows another embodiment of the method for recycling thermoplastic resin parts according to the present invention, in which a colored bumper 3 as a thermoplastic resin part painted with a thermosetting resin paint is shown.
1 is shown.

This colored bumper 31 has a bumper body 32 made of soft polypropylene,
The bumper body 32 is coated with a metallic paint 35 as a thermosetting resin paint via an undercoat 33 and an intermediate paint 34.

[0016] Also in this embodiment, if the colored bumper 31 has defects such as scratches in the manufacturing process (process A) and becomes a defective product, it is first processed in a crusher as in the above embodiment. The defective colored bumper 31 is crushed into crushed pieces such as ellipsoids and spheres having a length of 5 mm or less at the longest point (Step B). Next, the coated polypropylene obtained in the above step was applied to the intermediate layer of the long glass fiber reinforced stampable sheet at a mass percentage of 20 wt%.
It is mixed in at a ratio of 1, recycled (Step C), and reused for molding the long glass fiber reinforced stampable sheet (Step D).

In this case as well, in order to confirm the performance of the long glass fiber reinforced stampable sheet, the relationship between the flexural modulus Ea of the long glass fiber reinforced stampable sheet (recycled product), the glass fiber content and the recycled material mixing rate was determined. When the relationship was investigated, the results shown in FIG. 9 were obtained. As can be seen from FIG. 9, even in the long glass fiber reinforced stampable sheet of this example, the glass fiber content was 10 wt%.
If the above conditions are met and the recycled material content does not exceed 50 wt%, the flexural modulus Ea of the long glass fiber reinforced stampable sheet is a long glass fiber reinforced stampable sheet (virgin product) in which the coated polypropylene is not mixed. It was confirmed that the flexural modulus of elasticity exceeds the flexural modulus Ea of , and it was confirmed that the flexural modulus of elasticity can be made excellent like the long glass fiber reinforced stampable sheet 10 of the previous example.

Therefore, in the method for recycling thermoplastic resin parts according to the present invention, regardless of the type of thermoplastic resin used for the thermoplastic resin parts and the type of thermosetting resin used for the thermosetting resin paint, We were able to demonstrate that it is possible to recycle plastic resin parts.

[0019]

[Effects of the Invention] As explained above, in the method for recycling thermoplastic resin parts according to the present invention, painted thermoplastic resin parts are pulverized into pieces of 5 mm or less at the longest dimension to make them fine particles. After the recycled material is recycled, the recycled material is mixed into a recycled thermoplastic resin material containing 10 wt% or more of glass fiber for reuse. This makes it possible to regenerate defective thermoplastic resin parts in a state that allows them to be reused, which brings about the very excellent effect of greatly contributing to the conservation of the global environment.

[Brief explanation of drawings]

FIG. 1 is a process block diagram when recycling a colored bumper (thermoplastic resin part) showing an embodiment of the method for recycling thermoplastic resin parts according to the present invention.

FIG. 2 is a perspective view of the colored bumper shown in FIG. 1;

FIG. 3 is a partially enlarged sectional view of the colored bumper in FIG. 2;

4 is a side view schematically showing a stamping molding apparatus for molding the long glass fiber reinforced stampable sheet of FIG. 1. FIG.

5 is a partially enlarged sectional view of the long glass fiber reinforced stampable sheet of FIG. 1. FIG.

FIG. 6 shows the relationship between the flexural modulus of the long glass fiber reinforced stampable sheet (recycled product) shown in FIG. It is a graph shown in comparison with the bending elastic modulus of.

FIG. 7 is a graph showing the relationship between the flexural modulus of the long glass fiber reinforced stampable sheet (recycled product) shown in FIG. 1 and the length of the recycled material.

FIG. 8 is a partially enlarged sectional view of a metallic-painted colored bumper (thermoplastic resin part) showing another embodiment of the method for recycling thermoplastic resin parts according to the present invention.

FIG. 9 shows the relationship between the flexural modulus, glass fiber content, and recycled material content of a long glass fiber reinforced stampable sheet (recycled product) obtained by recycling the colored bumper shown in FIG. It is a graph shown in comparison with the bending elastic modulus of a fiber-reinforced stampable sheet (virgin product).

FIG. 10 is an explanatory diagram of the operation of the method for recycling thermoplastic resin parts according to the present invention.

FIG. 11 is a process block diagram for recycling an unpainted bumper (thermoplastic resin part), showing a conventional method for recycling thermoplastic resin parts.

[Explanation of symbols]

1 31 Colored bumper (thermoplastic resin parts)
1A Painted polypropylene (recycled material) 4 Top coat (thermosetting resin paint) 10 Long glass fiber reinforced stampable sheet (thermoplastic resin material for recycling)

Claims (1)

[Claims] Claim 1: When reusing a thermoplastic resin part coated with a thermosetting resin paint, the coated thermoplastic resin part is crushed into pieces of 5 mm or less at the longest dimension to produce recycled material. After that, the recycled material is mixed into a recycled thermoplastic resin material containing 10 wt % or more of glass fibers and reused.