JP2006037049A - Recycling method of car part made of polypropylene and coating utilizing polypropylene waste material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recycling method of car parts made of polypropylene capable of utilizing the car parts made of polypropylene as a coating component. <P>SOLUTION: This recycling method comprises process A where the car parts made of polypropylene and having become a waste are coarsely pulverized to a not greater than 10 mm average diameter, process B where the coarsely pulverized polypropylene is finely pulverized to a not greater than 300 μm average diameter by a freeze crushing method, process C where the finely pulverized polypropylene is dissolved in an aliphatic solvent or an aromatic solvent, process D where the dissolved solution is filtered to extract a polypropylene filtrate, and process E where the polypropylene filtrate is mixed with a base resin of this coating. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention utilizes a recycling method for polypropylene automobile parts, and a polypropylene waste material, which reuses automobile parts made of polypropylene (hereinafter also referred to as PP) collected during repair of used automobiles and automobiles as components of paint. The present invention relates to a paint and a method for producing the same.

  In general, polypropylene automobile parts collected at the time of repair of used automobiles and automobiles are reused as materials for automobile parts after cutting, crushing and removing impurities. For example, a PP bumper that has become a waste material is cut and crushed, and after impurities are removed, it is reused again as an automobile bumper.

  However, when the recycled material is reused as a resin material, the color of the parts collected from the used car and the color of the parts to be reused must be the same color. Further, there is a condition that the molecular weight, the degree of polymerization, the composition, and the blending amount of the recycled material and the resin material to be reused must be almost the same. In the future, it is expected that the amount of polypropylene automobile parts collected from used cars will increase, so it is necessary to create a reuse destination in addition to reuse as a resin material.

  In addition, since paints for automobiles use non-combustible inorganic substances such as talc as paint fillers, the paint film is incinerated when incineration of paint residues and shredder dust when automobiles are scrapped. There was a need to landfill the residue.

  In addition, since the polypropylene material is a thermoplastic material, if it is pulverized by a physical method such as a ball mill, a roll crusher, a rotary cutter, etc., and the particle size is reduced, the softening point of the material is exceeded by frictional heat. It was difficult to finely pulverize, and it was difficult to use a pulverized polypropylene product as a paint component.

  Furthermore, because polypropylene resins used in automobiles have excellent solvent resistance, polypropylene resins roughly pulverized by physical methods such as ball mills, roll crushers, and rotary cutters are not at high temperatures. It is difficult to make it compatible with the solvent. For this reason, it has been difficult to mix polypropylene that is compatible with the solvent into the paint.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for recycling a polypropylene automobile part, a paint using a polypropylene waste material, and a method for producing the same, in which a polypropylene automobile part can be reused as a component of the paint.
In order to achieve the above object, according to the first aspect of the present invention, a step of coarsely pulverizing a polypropylene automobile part, which has become a waste product, so that the average particle diameter is preferably 10 mm or less, A step of finely pulverizing the pulverized polypropylene pulverized product by a freeze pulverization method so that the average particle size is preferably 300 μm or less, and the pulverized polypropylene pulverized product as an aliphatic solvent or an aromatic solvent. Providing a method for recycling polypropylene automotive parts, comprising: a step of dissolving; a step of filtering the solution to extract a polypropylene filtrate; and a step of mixing the polypropylene filtrate with a base resin of a paint. Is done.

  In order to achieve the above object, according to the second aspect of the present invention, a step of roughly pulverizing a polypropylene automobile part, which has become a waste product, preferably so that the average particle size is 10 mm or less, The coarsely pulverized polypropylene pulverized product is pulverized by a freeze pulverization method so that the average particle size is preferably 300 μm or less, and the finely pulverized polypropylene pulverized product is mixed with an aliphatic solvent or an aromatic solvent. A polypropylene waste material comprising: a step of dissolving in a solvent; a step of filtering the solution to extract a polypropylene filtrate; and a step of mixing the polypropylene filtrate with a base resin and other components of a paint. A method of producing a paint using the above is provided.

  Furthermore, in order to achieve the above object, according to a third aspect of the present invention, (A) a base resin of any one of an acrylic urethane resin, an aqueous emulsion resin, or an aqueous synthetic rubber latex resin, and (B ) Crudely pulverized polypropylene automotive parts, which have become waste, so that the average particle size is 10 mm or less, and finely pulverize the coarsely pulverized polypropylene pulverized product so that the average particle size is 300 μm or less by a freeze pulverization method. And a polypropylene filtrate obtained by dissolving the finely pulverized polypropylene pulverized product in an aliphatic solvent or an aromatic solvent, and filtering the dissolved solution, and the polypropylene is added to 100 parts by weight of the base resin. Provided is a paint using a polypropylene waste material, wherein the filtrate is contained in an amount of 300 parts by weight or less.

  In the present invention, the automobile parts made of polypropylene, which has become a waste product, are pulverized in two stages, that is, coarsely pulverized so that the average particle size is 10 mm or less, and then the coarsely pulverized polypropylene pulverized product is subjected to an average particle size by a freeze pulverization method. Is pulverized to be 300 μm or less. Thereby, it can grind | pulverize easily, without exceeding a softening point by frictional heat.

  In the present invention, the pulverized polypropylene pulverized product is dissolved in an aliphatic solvent or an aromatic solvent, and the solution is filtered to extract the polypropylene filtrate. Therefore, even if the waste material is painted, It can be removed by a dissolution / filtration process.

  In the present invention, recycled polypropylene material is reused as a component of paint, so that the same color, molecular weight, degree of polymerization, composition, and blending amount are required when reused for resin parts. No longer needed. Therefore, the reuse destinations of the polypropylene automobile parts that have been discarded are significantly expanded.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a process diagram showing a recycling method and a paint manufacturing method according to the present invention.
A general automobile paint is composed of three components: a base resin (binder), an inorganic filler, and an additive. The paint according to the present invention is 300 parts by weight or less in place of an inorganic filler such as calcium carbonate or talc. It is characterized by containing the following polypropylene resin.

  The paint according to the present invention can be applied as various chipping-resistant paints such as undercoat paint, anti-chipping coat paint, stone guard coat paint, etc. to the floor under the automobile body, tire house, sill outer panel, lower part of door outer panel, etc. In addition, it can be used as an intermediate coating or top coating. In particular, since polypropylene is included as a paint component, an elastic coating film can be formed, which is preferable as a chipping-resistant paint.

(Materials used)
As polypropylene resin to be recycled, polypropylene automobile parts such as bumpers, moldings, instrument panels, pillar covers, linings, engine covers and the like recovered from used automobiles and automobile repairs are used. Recycled polypropylene automobile parts can be used even if they are painted or colored.

(Coarse grinding step A)
As shown in FIG. 1, when reusing as a paint component, the polypropylene automobile parts are first roughly pulverized.

  In this rough crushing, a polypropylene automobile part is generally roughly pulverized by a pulverizer for pulverizing a resin molded product so that the average particle diameter becomes 10 mm or less. It is desirable to make the particle size as small as possible in order to increase the efficiency of pulverization, which is the next step. The pulverizer used in this step may be a general one that can pulverize plastic materials.

(Fine grinding process B)
The polypropylene pulverized product having an average particle size of 10 mm or less by the coarse pulverization is crushed by a pulverizer until the average particle size is 300 μm or less in a state cooled to −80 to −40 ° C. at the material surface temperature. If the average particle size is 300 μm or more, the dissolution time in the solvent becomes longer in the next step, and if the average particle size is 5 mm or more, it cannot be dissolved in the solvent. The pulverizer used in this step may be a general pulverizer capable of pulverizing the plastic material to 300 μm or less at a low temperature of −80 to −40 ° C.

(Material adjustment)
The polypropylene pulverized product having an average particle size of 300 μm or less is dissolved in an aliphatic solvent or an aromatic solvent (dissolution step C), and then filtered to extract a filtrate in which the polypropylene material is dissolved (filtration step D). ).

  The solvent used here is preferably an aliphatic solvent such as pentane, hexane, or octane having a solubility parameter close to that of polypropylene resin, or an aromatic solvent such as toluene, xylene, or cyclohexane.

  If an ester, ketone or alcohol solvent is used as the solvent, the polypropylene material will not dissolve. In addition, when an ester solvent or a ketone solvent is used as the solvent, the coating film adhering to the polypropylene material or the pigment used in the polypropylene material is dissolved, so that it is not suitable as the solvent according to the present invention.

(Paint preparation process E)
The filtrate obtained by dissolving the polypropylene material extracted in the above step is mixed with 100 parts by weight of the base resin component of the paint, up to 300 parts by weight before dissolving the polypropylene material, and further, additives and solvents are mixed as necessary. And paint.

  As the base resin component of the paint, acrylic urethane resin, aqueous emulsion resin, and aqueous synthetic rubber latex resin can be used.

  If the filtrate in which the polypropylene material is dissolved is mixed in excess of 300 parts by weight before dissolution, the adhesion and chipping with the object to be coated may be reduced after the coating film is formed, and the coating film may be peeled off.

  As additives to be mixed with the paint, anti-aging agents, surfactants, antifoaming agents, dispersants, viscosity modifiers and the like can be blended as necessary. The solvent to be mixed with the paint is selected according to the type (material) of the base resin component of the paint.

  Since the paint according to the present invention can use polypropylene resins having different colors and performances, it can be recycled without sorting in advance. Furthermore, by using a dissolved polypropylene resin as a coating component, spray coating is possible and the appearance is excellent. In addition, since nonflammable calcium carbonate and talc are not used as extender pigments in the paint, and polypropylene resin is used as the paint component, there are few incineration residues during paint incineration, and the amount of landfill disposal can be reduced.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

(Example 1)
A polypropylene bumper collected from a used automobile was coarsely pulverized with a biaxial rotary cutter pulverizer until the average particle size became 10 mm or less, washed with water with a rotary cleaning device, and then dried.

  Further, the coarsely pulverized polypropylene pulverized product was crushed with a rotary cutter pulverizer until the average particle size became 300 μm or less in a state cooled to −80 to −40 ° C. at the material surface temperature.

  A filter paper (No. 5 manufactured by Advantech Toyo Co., Ltd.) capable of capturing 3 μm particles after mixing 100 parts by weight of a polypropylene pulverized product having an average particle size of 300 μm or less with a cyclohexane solvent, stirring and dissolving at 80 ° C. for 30 minutes. ) To obtain a filtrate in which the polypropylene material was dissolved.

  Next, 60 parts by weight of acrylic polyol which is hydroxyl group 50 and 40 parts by weight of hexamethylene diisocyanate which is a curing agent are added to the filtrate in which the polypropylene material obtained above is dissolved, and this is heated to 30 ° C. For 30 minutes. Next, 3 parts by weight of dibutyltin terephthalate (curing stabilizer) as an additive and 60 parts by weight of isopropyl acetate (solvent) were added and mixed with a disper for 1 hour to obtain a coating composition.

  This coating composition is applied to a steel plate that has been subjected to electrodeposition coating with a film thickness of 15 μm by coating with an airless gun so that the film thickness after baking and drying is 400 to 500 μm, dried at 80 ° C. for 10 minutes, The coating plate was produced by drying at 140 ° C. for 20 minutes.

(Example 2)
A coated plate was produced under the same conditions as in Example 1 except that 200 parts by weight of a polypropylene pulverized product having an average particle size of 300 μm or less was mixed with a cyclohexane solvent.

(Example 3)
A coated plate was produced under the same conditions as in Example 1 except that 300 parts by weight of a pulverized polypropylene product having an average particle size of 300 μm or less was mixed with a cyclohexane solvent.

(Comparative Example 1)
A coated plate was produced under the same conditions as in Example 1 except that 400 parts by weight of a polypropylene pulverized product having an average particle size of 300 μm or less was mixed with a cyclohexane solvent.

(Comparative Example 2)
The polypropylene bumper collected from the used automobile was coarsely pulverized with a biaxial rotary cutter type pulverizer until the average particle size became 10 mm or less, washed with water with a rotary type washing apparatus, and then dried.

  Further, the coarsely pulverized polypropylene pulverized product was crushed with a rotary cutter pulverizer until the average particle size became 300 μm or less in a state cooled to −80 to −40 ° C. at the material surface temperature.

  Next, 60 parts by weight of acrylic polyol as the hydroxyl group 50 and 40 parts by weight of hexamethylene diisocyanate as the curing agent were added to the pulverized polypropylene obtained above, heated to 30 ° C., and mixed with a disper for 30 minutes. Next, 3 parts by weight of dibutyltin terephthalate (curing stabilizer) as an additive and 60 parts by weight of isopropyl acetate (solvent) were added and mixed with a disper for 1 hour to obtain a coating composition.

  This coating composition is applied to a steel plate having a film thickness of 15 μm and applied with an airless gun so that the film thickness after baking and drying is 300 to 1000 μm, dried at 80 ° C. for 10 minutes, and further 140 ° C. And dried for 20 minutes to prepare a coated plate.

(Comparative Example 3)
A polypropylene bumper collected from a used automobile was roughly pulverized with a twin-screw rotary cutter pulverizer until the average particle size became 10 mm or less, washed with water with a rotary cleaning device, and then dried.

  Although 100 parts by weight of a polypropylene pulverized product having an average particle size of 10 μm or less was mixed with a cyclohexane solvent and stirred for 30 minutes at 80 ° C., the polypropylene pulverized product was not sufficiently dissolved.

(Comparative Example 4)
60 parts by weight of acrylic polyol as hydroxyl group 50, 40 parts by weight of hexamethylene diisocyanate as a curing agent, 50 parts by weight of calcium carbonate and 50 parts by weight of talc were heated to 30 ° C. and mixed for 30 minutes with a disper. Next, 3 parts by weight of dibutyltin terephthalate (curing stabilizer) and 60 parts by weight of isopropyl acetate (solvent) were added as additives and mixed with a disper for 1 hour to obtain a coating composition.

  This coating composition was applied to a steel plate having a film thickness of 15 μm and applied with an airless gun so that the film thickness after baking and drying was 400 to 500 μm, dried at 80 ° C. for 10 minutes, and further 140 ° C. And dried for 20 minutes to prepare a coated plate.

The conditions of Examples 1 to 3 and Comparative Examples 1 to 4 are shown in Table 1 above.

(Evaluation)
The following evaluation was implemented with respect to the coating board obtained by the said Examples 1-3 and Comparative Examples 1-4. The evaluation results are shown in Table 2.

(1) Appearance The surface smoothness of each coated plate obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was visually evaluated. A sample having good smoothness was marked with ◯, and a sample having poor smoothness was marked with ×.

(2) Initial adhesion In the coating film of each coating plate obtained in Examples 1 to 3 and Comparative Examples 1 to 4, 11 vertical and horizontal parallel lines that reach the substrate with a cutter knife are shaped like a grid. A cellophane tape having a width of 20 to 30 mm was brought into close contact with the drawn coating film at intervals of 2 mm and peeled off at one time, and the peeling state of the coating film was observed. Table 2 shows the number of squares not peeled out of 100 squares on the grid.

(3) Adhesiveness after moisture resistance test After leaving each coated plate obtained in Examples 1 to 3 and Comparative Examples 1 to 4 in a constant temperature and humidity tester maintained at 50 ° C. and 98% RH for 120 hours. After leaving the constant temperature and humidity tester and leaving it at room temperature for 24 hours, draw 11 lines of vertical and horizontal parallel lines that reach the substrate with a cutter knife at 2 mm intervals in a grid pattern. A cellophane tape having a width of 20 to 30 mm was brought into close contact with the coated film, peeled off at once, and the state of peeling of the coated film was observed. Table 2 shows the number of squares not peeled out of 100 squares on the grid.

(4) Chipping resistance Specified in JIS A5001 at an air pressure of 0.49 MPa on the coated plates obtained in Examples 1 to 3 and Comparative Examples 1 to 4 with a gravelometer specified in SAE J400. After repeatedly applying 500 g of No. 6 crushed stone 5 times, it was visually evaluated. The case where the coating film was not peeled off was rated as “◯”, and the case where the coating film was peeled off was rated as “X”.

(5) Weather resistance Each coated plate obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was exposed to a sunshine weather meter (black panel temperature 63 ° C., with rain) for 1000 hours, then taken out from the testing machine to room temperature. After leaving for 24 hours, the coating film is drawn with a cutter knife at 11 mm vertical and horizontal parallel lines at 2 mm intervals in a grid pattern, and 20-30 mm wide cellophane is drawn on the drawn coating film. The tape was brought into close contact, peeled off at once, and the state of peeling of the coating film was observed. Table 2 shows the number of squares not peeled out of 100 squares on the grid.

(6) Incineration residue After removing 10 g of the coating film from each coated plate obtained in Examples 1 to 3 and Comparative Examples 1 to 4 with a cutter knife, putting it in a crucible, and heating with a gas burner from the bottom for 30 minutes, The amount of incineration residue was measured.

  The coating films using the paints of Examples 1 to 3 had no problems in appearance, initial adhesion, adhesion after moisture resistance test, chipping resistance, weather resistance, and incineration residue.

  On the other hand, the coating material of Comparative Example 1 (PP finely pulverized product was 400 parts by weight) had poor adhesion after the moisture resistance test. In the paint of Comparative Example 2 (PP finely pulverized product is not dissolved or filtered in an aliphatic solvent or an aromatic solvent), the finely pulverized product has a rough appearance and has a problem in appearance. In Comparative Example 3 (only ground grinding), no paint could be produced. Further, the paint of Comparative Example 4 (conventional paint) protruded with an incineration residue of 50%, and landfill treatment became essential.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

It is process drawing which shows an example of the recycling method which concerns on this invention, and the manufacturing method of a coating material.

Explanation of symbols

A ... Coarse grinding process B ... Fine grinding process C ... Dissolution process D ... Filtration process E ... Paint preparation process

Claims (10)

A step of coarsely pulverizing a polypropylene automobile part that has become a waste product, a step of finely pulverizing the coarsely pulverized polypropylene pulverized material by a freezing pulverization method, and an aliphatic solvent or an aromatic Recycling of polypropylene automobile parts characterized by having a step of dissolving in a solvent, a step of filtering the solution to extract a polypropylene filtrate, and a step of mixing the polypropylene filtrate with a base resin of a paint Method. In the coarse pulverization step, the automobile parts made of polypropylene, which have become waste products, are crushed so as to have an average particle size of 10 mm or less, and in the fine pulverization step, the coarsely pulverized polypropylene pulverized product is frozen and pulverized. 2. The method for recycling polypropylene automotive parts according to claim 1, wherein the average particle size is finely pulverized by a method to be 300 μm or less. 3. The method for recycling polypropylene automobile parts according to claim 1, wherein the base resin of the paint is any one of acrylic urethane resin, aqueous emulsion resin or aqueous synthetic rubber latex resin. The said polypropylene filtrate is mixed in the ratio of 300 weight part or less with respect to 100 weight part of base resin of the said coating material, The recycling method of the polypropylene automobile parts in any one of Claims 1-3 characterized by the above-mentioned. A step of coarsely pulverizing a polypropylene automobile part that has become a waste product, a step of finely pulverizing the coarsely pulverized polypropylene pulverized material by a freezing pulverization method, and an aliphatic solvent or an aromatic A step of dissolving in a system solvent, a step of filtering the solution to extract a polypropylene filtrate, and a step of mixing the polypropylene filtrate with a base resin and other components of a paint. A method of manufacturing paints using waste materials. In the coarse pulverization step, the automobile parts made of polypropylene, which have become waste products, are crushed so as to have an average particle size of 10 mm or less, and in the fine pulverization step, the coarsely pulverized polypropylene pulverized product is frozen and pulverized. 6. The method for producing a coating material using a polypropylene waste material according to claim 5, wherein the fine particle is pulverized by a method so as to have an average particle size of 300 μm or less. The method for producing a paint using a polypropylene waste material according to claim 5 or 6, wherein the base resin of the paint is an acrylic urethane resin, an aqueous emulsion resin or an aqueous synthetic rubber latex resin. . The said polypropylene filtrate is mixed in the ratio of 300 weight part or less with respect to 100 weight part of base resin of the said paint, The manufacturing method of the coating material using the polypropylene waste material in any one of Claims 5-7 characterized by the above-mentioned. . The said coating material is applied to the under floor of an automobile body, a tire house, a sill outer panel, and a door outer panel as a chipping-resistant coating material, The manufacture of the coating material using the polypropylene waste material in any one of Claims 5-8 characterized by the above-mentioned. Method. (A) A base resin of any one of acrylic urethane resin, water-based emulsion resin or water-based synthetic rubber latex resin, and (B) a polypropylene automobile part which has become a waste product, is roughened so that the average particle diameter is 10 mm or less. The coarsely pulverized polypropylene pulverized product is finely pulverized by a freeze pulverization method so that the average particle size becomes 300 μm or less, and the finely pulverized polypropylene pulverized product is dissolved in an aliphatic solvent or an aromatic solvent. And a polypropylene filtrate obtained by filtering the solution, and containing a polypropylene filtrate in an amount of 300 parts by weight or less based on 100 parts by weight of the base resin.

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