JP2007237590A - Method for peeling coating film of resin molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for peeling a coating film surely from a resin molding cut in a prescribed size without using such a solvent as a coating film peeling agent. <P>SOLUTION: The method includes the first process for cutting the resin molding with the coating film formed on the surface into resin pieces 10 of a prescribed size, the second process for charging a prescribed amount of the resin pieces 10, a prescribed number of metal spheres 15 of a prescribed size, and a prescribed amount of water 18 into a container 20 of a prescribed capacity, and the third process for carrying out treatment, in which the inside of the container 20 is heated to a prescribed temperature, the container 20 is rotated at a prescribed rotational frequency, the resin pieces 10, the spheres 15, and the water 18 in the container 20 are mixed/agitated, and the coating film 11 is peeled off from the resin pieces 10, for a prescribed length of time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for removing a coating film of a resin molded body, in which a coating film coated on the surface of a resin molded body is peeled and removed from the resin molded body. More specifically, the present invention relates to a method for removing a paint film from a resin molded body, in which a paint film is peeled off from the resin molded body in order to allow recycling of a used resin molded body.

  Recycling and reusing resources is one of the important issues of modern times, such as the full enforcement of the Automobile Recycling Law. However, even in the case of an automobile, for example, the situation is that it is hardly recycled because it is cut and then disposed of as industrial waste or compressed into shredder dust. More specifically, even bumpers that are easy to remove from the car body and are considered not easy to recycle because they are not so dirty with gasoline, oil, etc. are not recycled. One of the causes is that it is difficult to remove the coating film from a resin molded body (resin molding material) such as a bumper. There was a problem that the quality, performance, and the like were deteriorated as compared with those molded by the above method. For example, a problem occurs in strength and the like.

  When enumerated from the patent literature, a conventional method for removing a coating film of a resin molded body is known from a technique in which a coating film peeling agent heated to a predetermined temperature is infiltrated and subjected to ultrasonic vibration (for example, , See Patent Document 1). A technique using a lower alcohol heated to a temperature below the boiling point is also known (see, for example, Patent Document 2). Furthermore, a technique for blasting a projection material is also known (see, for example, Patent Document 3).

  In addition, there is also known a technique in which after heating with flame radiation, pressing to flatten and scraping with a steel brush (see, for example, Patent Document 4). Furthermore, after the coating film layer is rapidly cooled to the embrittlement temperature, a technique for projecting a projection material, a technique for performing rotational driving similar to a rice milling machine, and the like are also known (see, for example, Patent Document 5 and Patent Document 6). ).

In addition, there is also known a technique in which a mixture of a resin chip and a medium of a thermosetting resin molding is put into a drum and is peeled by stirring (for example, see Patent Document 7). Furthermore, a technique is also known that removes the adhering paint by bringing a coated plastic chip and a hard sphere into vibration contact with each other in the paint remover (see, for example, Patent Document 8).
Japanese Patent Laid-Open No. 06-299107 Japanese Patent No. 3200934 JP 2002-066924 A Japanese Patent Application Laid-Open No. 07-108800 JP 2002-301424 A Japanese Patent Laid-Open No. 11-058379 JP 2001-315127 A Japanese Patent Laid-Open No. 06-063950

However, the conventional technique of peeling and removing the coating film from the resin molded body is not yet a completed technique and has room for improvement. For example, the techniques described in Patent Documents 1, 2, and 8 use a solvent such as a coating film remover, chemicals, etc., in the peeling process, so that the safety of the solvent, the management of deterioration, and the recycling after the peeling process are performed. There was a risk of problems in cleaning the product.
In addition, the use of solvents, chemicals, and the like may cause problems such as increased risk to humans and the occurrence of global environmental problems. Furthermore, since the techniques described in Patent Documents 3, 4, and 5 perform the peeling process before crushing the bumper, it is necessary to perform the process according to the shape of the bumper, and there are many types of jigs. Since there is one head, there is a problem that the peeling process takes a long time and the productivity is not good. In addition, the paint film may remain on the curved surface.

  Furthermore, the technique described in Patent Document 6 requires a blower, a back filter, or the like used as a separation means, which increases the size of equipment, increases equipment costs, and restricts installation locations. . In the technique described in Patent Document 7, it is difficult to separate the mixture of the resin chip and the media, and a dust treatment device, a cyclone, and the like are required. That is, there is a possibility that there is a problem in increasing the size of the equipment and increasing the installation cost.

  The present invention has been made in order to solve such problems of the prior art, and achieves the following object.

  The object of the present invention is to paint a resin molded body from a resin piece cut into a predetermined size with a simple coating film peeling apparatus without using a solvent, chemicals, etc. such as a coating peeling agent and a coating peeling agent. It is providing the peeling method of the coating film of the resin molding which can peel a film | membrane.

The present invention takes the following means to achieve the above object.
The method for peeling a coating film of a resin molded body of the present invention 1 is a method of peeling the coating film from a resin molded body having a coating film (11) formed on the surface, wherein the resin molded body is made a predetermined size. A first step of cutting the resin pieces (10), a predetermined amount of the resin pieces (10), a predetermined number and size of metal media (15) in a predetermined capacity container (20). ), A second step of charging a predetermined amount of water (18), and heating the inside of the container (20) to a predetermined temperature, rotating the container (20) at a predetermined rotational speed, The process which makes the said resin piece (10), the said medium (15), and the said water (18) in a container (20) mix and stir in the heated state, and peels the said coating film (11) from the said resin piece (10). Consists of a third step for a predetermined time.

  According to a second aspect of the present invention, there is provided a method for removing a paint film from a resin molded body according to the first aspect, wherein the outer shape of the medium is a sphere. However, the outer shape of the media may be a rectangular shape, a rectangular shape, an ellipsoid, or the like.

  In the present invention 4, the method for peeling a coating film of a resin molded body according to the present invention 1 or 2, the second step includes the accommodation volume of the container (20), the medium (15), and the resin piece (10 ) And the total volume of water (18) is a step of charging so that the ratio is approximately 2 to 1.

  According to the fifth aspect of the present invention, there is provided a method for removing a coating film of a resin molded body according to the first or second aspect, wherein the sphere (15) has a diameter of 12 to 18 mm, and the second step includes the container (20). The ratio of the volume and the number of the spheres (15) is a step of charging so that the number is 50 to 70 with respect to 1 liter of the volume.

  The method for peeling a coating film of a resin molded body of the present invention 6 is characterized in that, in the present inventions 1 to 5, the predetermined temperature is 90 to 110 ° C. at a set temperature of the heating section (28).

  According to the seventh aspect of the present invention, in the first to sixth aspects, the predetermined time is 50 to 70 minutes.

  As described above, the method for removing a coating film of a resin molded body according to the present invention is performed by mixing and stirring a resin piece and a metal sphere in hot water having a predetermined temperature stored in a container. The coating film could be easily peeled off. In addition, the coating film peeling apparatus that removes the coating film is simple and does not use solvents, chemicals, etc., such as paint stripping agents, so the deterioration of solvents, chemicals, etc., post-treatment of solvents, chemicals, etc., resin There is no need to perform post-treatment of the piece, so that productivity and economy are good. And it is possible to reduce the risk to humans and prevent the occurrence of global environmental problems. Therefore, recycling of the resin molded body can be promoted, and it can contribute to industrial waste reduction.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic diagram schematically showing a coating film peeling apparatus for carrying out the method for peeling a coating film of a resin molded body of the present invention, and FIG. 2 is an enlarged perspective view of a bumper piece. FIG. 3 is a diagram showing the relationship between the number of balls and the peeling efficiency, FIG. 4 is a diagram showing the relationship between the set temperature of the heating unit and the peeling efficiency, and FIG. 5 is a diagram showing the relationship between the amount of bumper pieces thrown and the peeling efficiency. FIG. 6 and FIG. 6 are diagrams showing the relationship between the peeling processing time and the peeling efficiency.

  In this embodiment, the resin molded body will be described by taking as an example a bumper of an automobile, which is injection-molded with a synthetic resin (for example, polypropylene) material and coated on the surface thereof. In other words, the bumper is a used bumper having a coating film formed on the surface thereof, and is a so-called waste bumper that is recycled after being removed from the body of a car that has been disposed of. Needless to say, the resin molded body may be a resin molded body other than the bumper.

  A waste bumper is a coating on the surface of an injection-molded bumper body, and a coating film is formed on the surface. The waste bumper was cut into chips of about 1 cm, for example, and a bumper piece (resin piece) 10 that was a chipped waste bumper was produced. The technique of cutting this waste bumper into the bumper piece 10 with a crusher, a cutting machine or the like is well known, and will not be described in detail here. The bumper piece 10 includes a bumper piece main body (resin piece main body) 12 and a coating film 11 attached to the bumper piece main body 12. A metal (for example, stainless steel) sealed container (hereinafter referred to as a container) 20 having a predetermined capacity was prepared. The container 20 includes a bumper piece 10, a metal (for example, stainless steel) sphere (hereinafter referred to as a ball) 15 having a predetermined size (diameter 15.8 mm), and a predetermined amount of water from the opening 21 of the container 20. 18 is put into the container 20, and the opening 21 is sealed with a lid 22.

  The coating film peeling apparatus 30 that peels the coating film 11 from the bumper piece 10 includes a rotation driving unit 27 that rotates the container 20 around the center line C at a predetermined rotation number, and the bumper piece 10 in the container 20. It comprises a heating unit 28 that heats from the outer peripheral side, a rotation drive unit 27, a control unit 29 that controls the heating unit 28, and the like. The heating unit 28 is preferably, for example, a unit provided with a heater having a nichrome wire or the like on the surface facing the outer peripheral portion of the container 20. It is preferable that the rotational drive part 27 is what transmits the driving force, such as a motor, to the container 20 directly or via a reduction gear etc., and rotates it.

The operation of the present embodiment will be described. In the present embodiment, the following steps are sequentially performed to perform the coating film peeling process.
In the first step, the waste bumper is cut into bumper pieces 10 having a predetermined size.
In the second step, a predetermined amount of bumper pieces 10, a predetermined number and size of balls 15, and a predetermined amount of water 18 are put into a container 20 having a predetermined capacity.
In the third step, the container 20 is installed in the paint film peeling apparatus 30. Thereafter, the container 20 and the inside of the container 20 are heated to a predetermined temperature by the heating unit 28, and the container 20 is rotated at a predetermined number of rotations, and the bumper piece 10, the sphere 15 and the water 18 in the container 20 are heated. A process of mixing and stirring and peeling the coating film 11 from the bumper piece 10 is performed for a predetermined time.

  By heating the container 20, the water 18, the ball 15, and the bumper piece 10 are heated, and the bumper piece 10 including the coating film 11 and the bumper piece main body 12 is softened. Further, when the temperature rises to around 100 ° C., water vapor is generated, and the surface coating film 11 is floated and becomes easy to peel off. The coating film 11 is peeled from the bumper piece main body 12 by colliding the ball 15 with the heated bumper piece 10 and crushing the coating film 11.

In order to confirm the effect relating to the method of peeling the coating film of the resin molded body of the present embodiment, experiments were performed while changing the following items, and the effectiveness of the present embodiment was confirmed. This experiment was performed using an apparatus (hydrothermal mill shaking pulverizer (Babcock-Hitachi, Om Lab Tech)) that can pulverize the coating film with a stainless steel ball while raising the temperature.
1. 1. Number of balls thrown into the container 20 Time for rotating the container 20 after reaching the set temperature (time for shaking)
3. Set temperature of heating unit 28 (temperature in container)
4). The amount of the bumper piece 10 to be put into the container 20

Hereinafter, the present embodiment will be described in detail by changing to an example.
[Example 1 Relationship between number of balls and peeling efficiency]
The input amount of the bumper piece 10 is 0.098 N (10 gf), the set temperature of the heating unit 28 is 90 ° C., the amount of water 18 is 100 mL, the rotational speed at which the rotation driving unit 27 rotates the container 20 and the like is 300 rpm. The relationship between the number of balls 15 to be introduced and the separation efficiency was determined. The container 20 was made of stainless steel having a capacity of 1 L (liter) and an inner diameter of 12 cm. In addition, it is preferable that the amount of the water 18 is an amount that the bumper piece 10 is sufficiently wetted in the container 20. In this Example 1 and Examples 2 to 5 to be described later, the amount of the water 18 is equal to or substantially equal to the bumper piece 10. Water 18 is introduced. That is, although the amount of water 18 is 100 mL, it may be about 90 to 110 mL. In Example 1 and Examples 2 to 5 to be described later, the ball having a diameter of 15.8 mm is used, but it may be about 12 to 18 mm.

The bumper piece 10 and the like in the container 20 are heated to a set temperature of 90 ° C. of the heating unit 28, and the container 20 is rotated at a rotation speed of 300 rpm to mix and stir the heated bumper piece 10, balls 15 and water 18. .
By heating the container 20, the water 18, the ball 15 and the bumper piece 10 are heated. The bumper piece main body 12 having the coating film 11 adhered to the surface is heated to a predetermined temperature and softens. Further, by rotating the container 20, the balls 15 collide with the heated bumper pieces 10 to pulverize the coating film 11, and the coating film 11 is peeled off from the bumper piece main body 12. Further, the coating film 11 is peeled from the bumper piece main body 12 by performing an operation of rubbing the bumper piece 10 and the ball 15 and the bumper piece 10 and the bumper piece 10.

  An experiment for determining the relationship between the number of balls 15 and the separation efficiency was performed while changing the number of balls 15 to 30 to 50, and the results are shown in FIG. The weight of one ball 15 is 0.163 N (16.6 gf), and 60 balls is 9.6 N (980 gf). As shown in FIG. 3, the separation efficiency increased as the number of balls 15 placed in the container 20 was 60% for 30 pieces, 70% for 45 pieces, and 80% for 60 pieces. When the diameter of the ball 15 is 15 ± 3 mm, the number of the balls 15 is preferably 60, and may be 50 to 70. On the other hand, if the number of balls 15 is too large with respect to the accommodation volume of the container 20, the balls 15 and the bumper pieces 10 may not be mixed well.

  In addition, the peeling efficiency as used in Example 1 and Examples 2 to 5 described later is a numerical value roughly determined by visual inspection. The peeling efficiency is preferably higher for recycling. However, in consideration of the energy cost for achieving this, in this Example 1 and Examples 2 to 5 to be described later, an experiment was conducted with a target of about 80 to 90%. ing.

[Example 2 Relationship between set temperature of heating section and peeling efficiency]
The charging amount of the bumper piece 10 is 0.098 N (10 gf), the amount of water 18 is 100 mL, the rotational speed for rotating the container 20 is 300 rpm, the number of balls 15 is 60, the peeling treatment time is 1 hour, and the heating unit 28 The relationship between the set temperature and the peeling efficiency was obtained. The container 20 was made of stainless steel having a capacity of 1 L.
While changing the set temperature of the heating unit 28, the container 20 is rotated at a rotation speed of 300 rpm, and the bumper piece 10, the ball 15, and the water 18 are mixed and stirred.

By heating the container 20, the water 18, the ball 15 and the bumper piece 10 are heated. The bumper piece 10 composed of the coating film 11 and the bumper piece main body 12 is softened. Further, the coating film 11 is peeled from the bumper piece main body 12 by colliding the ball 15 with the heated bumper piece 10 and crushing the coating film 11.
The experiment was performed with the set temperature of the heating unit 28 set at 30 to 110 ° C., and the result is shown in FIG. As shown in FIG. 4, the set temperature of the heating unit 28 is 5% at normal temperature (30 ° C.), the peel efficiency is about 90% at the set temperature 90 ° C., and the peel efficiency is about 95% at the set temperature 110 ° C. The set temperature was 110 ° C. That is, when the temperature rises to around 100 ° C., water vapor is generated, and the coating film 11 on the surface is lifted and becomes easy to peel off.

  In this state, the container 20 is rotated, and the ball 15 collides with the heated bumper piece 10 to pulverize the coating film 11. Further, an operation of rubbing against the bumper piece 10 and the ball 15 is also performed, and the coating film 11 is peeled off from the bumper piece main body 12. Thereby, the peeling efficiency which peels the coating film 11 from the bumper piece main body 12 increases. However, the temperature exceeding 110 ° C. requires more energy, and the peeling efficiency does not increase as much as this energy increase.

[Example 3 Relationship between Bumper Piece Amount and Peeling Efficiency]
The amount of water 18 is 100 mL, the set temperature of the heating unit 28 is 110 ° C., the number of rotations for rotating the container 20 is 300 rpm, the number of balls 15 is 60, the peeling treatment time is 1 hour, and the bumper piece 10 to the container 20 The relationship between the input amount and the peeling efficiency was obtained. The experiment was conducted with the input amount of the bumper piece 10 being 0.098 N (10 gf) to 0.98 N (100 gf), and the results are shown in FIG.

  As shown in FIG. 5, the separation efficiency is a little high when the amount of the bumper piece 10 input is as small as 0.098 N (10 gf), but there is not much change from 0.196 N (20 gf) to 0.98 N (100 gf). . That is, even when the input amount of the bumper piece 10 was increased to 0.98 N (100 gf), a peeling efficiency of 80 to 90% was obtained. The input amount of the bumper piece 10 is preferably such that the bumper piece 10 is sufficiently wetted by the water 18 in the container 20, and the bumper piece 10 and the water 18 are preferably equal or nearly equal.

[Example 4 Relationship between peeling treatment time and peeling efficiency]
The amount of water 18 is 100 mL, the set temperature of the heating unit 28 is 90 ° C., the input amount of the bumper piece 10 is 0.098 N (10 gf), the number of balls is 60, and the number of rotations for rotating the container 20 is 300 rpm. The relationship between the peeling treatment time and the peeling efficiency was obtained by changing the time. The experiment was carried out with a stripping treatment time of 15 to 60 minutes, and the results are shown in FIG.
As shown in FIG. 6, although a certain degree of peeling efficiency was obtained even when the peeling treatment time was 30 minutes, the peeling efficiency increased when the peeling treatment time was 60 minutes. In other words, the peeling treatment time was preferably about 60 ± 10 minutes. Moreover, even if it peels for a long time exceeding 60 minutes, peeling efficiency does not change so much.

[Example 5: Relationship between coating film color and peeling efficiency]
From the above results, when the coating film peeling process is performed in a 1 L container 20, the number of balls 15 having a diameter of 15.8 mm is 60, the amount of water is 100 mL, the set temperature is 110 ° C., and the peeling process time is 60 minutes. It was determined that the input amount of 10 is preferably 0.98 N (100 gf) or less. Under this peeling treatment condition, an experiment was conducted with bumper pieces having paint films with red, white and yellow paint colors, and the results are shown in FIG. As shown in FIG. 5, although the coating film peeled off or peeled off depending on the type of coating color, a stripping efficiency of 80 to 90% could be obtained with any coating color.

Moreover, the following could be confirmed from the results of Examples 1 to 5 described above.
The number of balls 15 is 60 ± 10, the amount of water is 100 ± 10 mL, the set temperature is 90 to 110 ° C., the peeling treatment time is 60 ± 10 minutes, and the input amount of the bumper piece 10 is 0.98 N (100 gf) or less. Was preferred. And it was suitable for the total volume of the ball | bowl 15, the bumper piece 10, and the water 18 with respect to the accommodation volume of the container 20 to be about 40 to 60%. In other words, the ratio of the volume of the container to the total volume of the balls, bumper pieces and water is preferably about 2 to 1. Moreover, even if there are too many balls, the balls and the bumper pieces may not be mixed well.

Furthermore, when the container size is increased and a larger amount of bumper pieces are peeled off, the size of the container, the amount of bumper pieces, the amount of water and the number of balls are determined in proportion to the aforementioned ratio. It is preferable to do.
The coating film 11 of the bumper piece 10 is easily peeled off because the water vapor wets the coating film 11 and floats the coating film 11 from the bumper piece main body 12 and is mixed and stirred with the ball 15 in a state of being easily peeled off. That is, since no solvent, chemicals, etc. are used, it is possible to reduce solvent costs, reduce risks to humans due to chemical substances, and prevent environmental problems.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. Needless to say, modifications can be made without departing from the scope and spirit of the present invention. For example, mixing and stirring is performed by rotating the container around the center line facing in the horizontal direction, but it may be rotated around the center line facing in the vertical direction and inclined at a predetermined angle. You may rotate in the direction around the center line that points in the direction.

FIG. 1 is a schematic view schematically showing a coating film peeling apparatus for carrying out the coating film peeling method of the resin molded body of the present invention. FIG. 2 is an enlarged perspective view of the bumper piece. FIG. 3 is a diagram showing the relationship between the number of balls and the separation efficiency. FIG. 4 is a diagram showing the relationship between the set temperature of the heating unit and the peeling efficiency. FIG. 5 is a diagram showing the relationship between the amount of bumper pieces introduced and the separation efficiency. FIG. 6 is a diagram showing the relationship between the peeling treatment time and the peeling efficiency.

Explanation of symbols

10 ... Resin piece (bumper piece)
11 ... Paint film 12 ... Resin piece body (bumper piece body)
15 ... sphere (ball)
DESCRIPTION OF SYMBOLS 20 ... Metal container 22 ... Lid 27 ... Rotation drive means 28 ... Heating part 30 ... Paint film peeling apparatus

Claims (7)

A method of peeling the coating film from a resin molded body having a coating film (11) formed on the surface,
A first step of cutting the resin molded body into resin pieces (10) of a predetermined size;
A second amount of a predetermined amount of the resin pieces (10), a predetermined number and size of metal media (15), and a predetermined amount of water (18) are put into a container (20) having a predetermined capacity. And the process of
While heating the inside of the container (20) to a predetermined temperature, the container (20) is rotated at a predetermined rotation number, and the resin piece (10), the medium (15), and the medium in the container (20) A resin molding characterized by comprising a third step of mixing and stirring water (18) in a heated state and performing a treatment for peeling off the coating film (11) from the resin piece (10) for a predetermined time. How to remove the coating film on the body. In the peeling method of the coating film of the resin molding described in Claim 1,
The outer shape of the media is a sphere. In the peeling method of the coating film of the resin molding as described in Claim 1 or 2,
The resin molded body is a bumper of an automobile. A method for peeling a coating film of a resin molded body, characterized in that: In the peeling method of the coating film of the resin molding as described in Claim 1 or 2,
In the second step, the ratio of the accommodation volume of the container (20) and the total volume of the media (15), the resin piece (10) and the water (18) is a ratio of about 2 to 1. A method for removing a coating film of a resin molded body, characterized in that the step is a step of charging so that In the peeling method of the coating film of the resin molding as described in Claim 1 or 2,
The sphere (15) has a diameter of 12 to 18 mm,
In the second step, charging is performed so that the ratio of the capacity of the container (20) and the number of the spheres (15) is 50 to 70 with respect to 1 liter of the capacity. It is a process, The peeling method of the coating film of the resin molding characterized by the above-mentioned. In the peeling method of the coating film of the resin molding as described in any one of Claim 1 to 5,
The said predetermined temperature is 90-110 degreeC by the preset temperature of a heating part (28). The peeling method of the coating film of the resin molding characterized by the above-mentioned. In the peeling method of the coating film of the resin molding as described in any one of Claim 1 to 6,
The predetermined time is 50 to 70 minutes. A method for removing a coating film of a resin molded body, wherein:

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