JP2007119755A - Exterior material made from resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exterior material made from a resin, having an excellent strength characteristic and realizing an effective utilization of resources by recycling waste plastics. <P>SOLUTION: This exterior material made from the resin is obtained by molding a mixed/kneaded material obtained by mixing and kneading an inorganic filler obtained by decomposing plastics containing at least the inorganic filler and a resin with subcritical fluid and recovering, with a thermoplastic resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin exterior material that is obtained by treating and recycling used waste plastic represented by, for example, FRP (glass fiber reinforced plastic).

  Plastics are lightweight, high-strength, have excellent rust resistance, corrosion resistance, electrical insulation, moldability, colorability, etc., and have the advantage of being capable of mass production. It is widely used for applications. As the amount of plastic used increases, the amount of used plastic discarded also tends to increase. In order to recycle used plastic waste and reduce the burden on the environment, research and development has been actively promoted. Yes.

  Plastics are broadly classified into thermosetting resins and thermoplastic resins. In addition to the use of the resin alone, if strength is required, glass fiber or Fiber reinforced plastics (FRP: Fiber Reinforced Plastics) including reinforcing materials such as carbon fibers are used. Thermoplastic resins are relatively easily processed by heating and melting, but thermosetting resins or plastics such as FRP are difficult to process by heating and melting. For this reason, waste plastic is crushed and then landfilled, but in the future, a shortage of landfill is expected. In addition, thermal recycling using waste plastic as fuel has attracted attention, but it also has problems such as generation of harmful substances (for example, dioxin) when waste plastic is incompletely combusted. For this reason, there is an urgent need to establish a method for treating waste plastic.

Therefore, a method is disclosed in which waste plastics are decomposed with subcritical water in a state of a critical point (critical temperature 374 ° C., critical pressure 22.1 MPa) or less to recover a resin monomer or an inorganic substance (see Patent Document 1). ).
JP-A-11-140224

  As described above, according to the method of treating waste plastic using subcritical water, the resin monomer or oligomer and the inorganic substance can be recovered from the waste plastic, but the recovered inorganic substance can be reused as an inorganic filler. Was difficult.

  In addition, even if the recovered inorganic material is used as an inorganic filler mixed with a thermosetting resin such as an epoxy resin or a phenol resin, the strength of the resulting molded product is higher than when an unused inorganic filler is used. There was a tendency for the characteristics to deteriorate.

  The present invention has been made to solve the above-described problems. That is, the resin exterior material of the present invention is an inorganic material recovered by decomposing a plastic containing at least an inorganic filler and a resin with a subcritical fluid. The gist is obtained by molding a kneaded material obtained by kneading a filler and a thermoplastic resin.

  According to the resin exterior material of the present invention, excellent strength characteristics can be obtained by reusing the inorganic material recovered by hydrolyzing the plastic with subcritical water as an inorganic filler, and further by recycling the waste plastic. Resources can be used effectively.

  Hereinafter, the resin exterior material according to the embodiment of the present invention will be described.

  The resin exterior material according to the embodiment of the present invention is a mixed material obtained by kneading an inorganic filler recovered by decomposing a plastic containing at least an inorganic filler and a resin with a subcritical fluid, and a thermoplastic resin. It was obtained by molding a smelt. More specific description will be given below.

  First, a plastic containing at least an inorganic filler and a resin is hydrolyzed with a subcritical fluid to recover the inorganic filler.

  Into a heat and pressure resistant container, a plastic and a subcritical fluid coarsely pulverized to a size of 0.5 mm to 10 mm are charged and heated while being pressurized. Then, the plastic is hydrolyzed into a resin monomer or oligomer and an inorganic substance such as an inorganic filler (for example, calcium carbonate).

  Here, as the resin contained in the plastic, either a thermosetting resin or a thermoplastic resin can be used. Examples of the thermosetting resin include unsaturated polyester resins, acrylic resins, epoxy resins, polyurethane resins, amino resins, and phenol resins. Examples of the thermoplastic resin include vinyl chloride resin, polyethylene resin, polystyrene resin, polypropylene resin, polybutadiene resin, alkyd resin, polycarbonate resin, and polyamide resin. Particularly, among the exemplified resins, thermosetting resins such as unsaturated polyester resins that are difficult to decompose by heating are preferable.

  Examples of the inorganic filler contained in the plastic include glass fiber, calcium hydroxide, calcium carbonate, mica (phlogopite), silica, silicate (clay, etc.), alumina, titania, zirconia, talc, etc. The inorganic filler preferably contains glass fiber, aluminum hydroxide, or calcium carbonate. This is because the use of glass fiber as the inorganic filler increases the strength of the molded resin exterior material, and the use of aluminum hydroxide as the inorganic filler improves the flame retardancy of the molded resin exterior material. is there. As a plastic containing such an inorganic filler, for example, fiber reinforced plastics (FRP) including a reinforcing material such as glass fiber or carbon fiber in an epoxy resin or unsaturated polyester resin as a base material is used. Is preferred.

  The inorganic filler is preferably contained at a ratio of 50% by weight to 80% by weight with respect to the total weight of the inorganic filler and the thermoplastic resin, and the recovered inorganic filler is 10% by weight to 40%. It is preferable to contain in the ratio of weight%. In addition to the inorganic materials described above, inorganic waste materials such as concrete powder, glass powder, and incinerated ash can be used as the remaining components.

  Furthermore, the average particle size of the plastic before being decomposed by the subcritical fluid is preferably 0.5 mm to 10 mm, and particularly preferably 0.5 mm to 2 mm. If the average particle size of the plastic is less than 0.5 mm, it becomes difficult to separate the inorganic filler from the plastic decomposition solution after subcritical decomposition by filtration. Conversely, the average particle size of the plastic is 10 mm. This is because it becomes difficult to mold.

  As the subcritical fluid, water, monohydric alcohol, polyhydric alcohol, or a mixture thereof can be used. Examples of the monovalent alcohol include methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol. Examples of the polyhydric alcohol include glycols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol, but the alcohol is not limited to the exemplified alcohols. When water is used as the subcritical fluid, it is preferable to carry out a desalting treatment in advance. In order to accelerate decomposition, an alkali metal hydroxide aqueous solution may be used as the subcritical fluid.

  The subcritical fluid is preferably blended in the range of 100 wt% to 500 wt% with respect to 100 wt% of the plastic. If the blending amount of the subcritical fluid is less than 100% by weight, the plastic cannot be stably decomposed. Conversely, if the blending amount of the subcritical fluid exceeds 500% by weight, the processing cost of the fluid after the decomposition Because it becomes higher. When an aqueous solution of an alkali metal hydroxide is used as the subcritical fluid, the alkali metal hydroxide is preferably blended in the range of 20 to 100% by weight with respect to 100% by weight of the plastic.

  The temperature during decomposition is preferably 180 ° C to 270 ° C. This is because if the temperature at the time of decomposition is less than 180 ° C., it takes a long time for the decomposition treatment. Conversely, if the temperature at the time of decomposition exceeds 270 ° C., the reaction of thermal decomposition proceeds rather than hydrolysis. This is because it becomes difficult to recover the polymer as a monomer or an oligomer.

  The time and pressure at the time of decomposition are not particularly limited, but when the temperature is 180 ° C. to 270 ° C., it is preferably 1 to 4 hours and 2 to 15 MPa.

  Under the above conditions, the plastic is decomposed with a subcritical fluid, followed by filtration to separate the resin monomer or oligomer and inorganic substances (calcium carbonate, glass fiber, etc.). A subcritical fluid in which a resin monomer or oligomer is dissolved is recovered as a filtrate after filtration, and an inorganic substance is recovered as a residue. When an aqueous solution of alkali metal hydroxide is used as the subcritical fluid, the recovered inorganic substance can be reused as it is. However, since alkali metal adheres to the residue after filtration, If the residue with the metal attached is kneaded into the resin as an inorganic filler, there is a possibility of adversely affecting the chemical performance typified by the performance against acid rain of the molded resin exterior material. For this reason, the residue after filtration may be washed with water to remove the alkali component adhering to the residue.

  Next, a method for kneading the inorganic filler and the thermoplastic resin will be described. Specifically, using a kneader, the recovered inorganic filler and the thermoplastic resin are uniformly kneaded to obtain a raw material for the resin exterior material. In order to obtain a uniform kneaded product, the kneader may be appropriately heated during kneading to knead while melting the thermoplastic resin.

  Here, examples of the thermoplastic resin include, but are not limited to, vinyl chloride resin, polyethylene resin, polystyrene resin, polypropylene resin, polybutadiene resin, alkyd resin, polycarbonate resin, and polyamide resin.

  The inorganic filler is preferably blended at a ratio of 50 to 80% by weight with respect to the total weight of the inorganic filler and the thermoplastic resin, and the recovered inorganic filler is 10% by weight to the total weight. It is preferable to contain in the ratio of 40 weight%. This is because when the recovered inorganic filler is less than 10% by weight, the strength of the resin exterior material is lowered. On the contrary, if the inorganic filler exceeds 40% by weight, the specific gravity of the molded resin exterior material increases, the weight per exterior material increases, and the workability during construction decreases.

  Finally, the kneaded product of the obtained inorganic filler and thermoplastic resin is heat-molded, and it is a resin building material (resin used for building exteriors such as wall materials and roof tiles and outdoors) Manufacturing exterior materials). The molding conditions (mold temperature, plus pressure, etc.) can be appropriately set according to the shape of the resin exterior material.

  Hereinafter, a specific description will be given using examples. In Examples 1 to 4, FRP (FRP bathtub manufactured by Matsushita Electric Works Co., Ltd.) was used as the plastic. Specifically, FRP containing 20% by weight of unsaturated polyester resin and 20% by weight of glass fiber, 55% by weight of calcium carbonate, and 5% by weight of other inorganic substances as a reinforcing material was used. In addition, the resin exterior material of this invention is not limited to the Example illustrated below.

Example 1
In a pressure vessel, 600 g of FRP coarsely pulverized to a size of 2 mm and 2400 g of a 0.8 mol / L potassium hydroxide aqueous solution were added, and then the water in the pressure vessel was heated with a heater to form a subcritical state (critical The FPR was hydrolyzed by setting it to a point (state of a critical temperature of 374 ° C. and a critical pressure of 22.1 MPa) or less and leaving it for 2 hours.

  Then, after cooling the pressure vessel to room temperature, the content was filtered with a Buchner funnel to remove the monomer or oligomer component of the resin obtained by decomposition.

  Next, the washed residue was dried with a dryer at 140 ° C. for 4 hours to remove water and recover the inorganic filler.

  The recovered inorganic filler (20% by weight), concrete powder (45% by weight) and polypropylene resin (35% by weight) were kneaded until they became uniform while being heated to 230 ° C. with a kneader. The obtained kneaded material was molded by a press machine to obtain a test sample having a length of 400 mm, a width of 400 mm, and a thickness of 5 mm. The molding conditions at this time were a charge amount of 300 g, a mold temperature of 120 ° C., a molding pressure of 6 kg / cm 2, and a charge time of 60 seconds.

Example 2
In Example 2, the inorganic filler was recovered using the same method as in Example 1 except that FRP coarsely pulverized to a size of 10 mm was used, and the test sample was prepared using the same method as in Example 1. Obtained.

Example 3
In Example 3, the inorganic filler was recovered using the same method as in Example 1 except that FRP coarsely pulverized to a size of 10 mm was used. Then, 20% by weight of the recovered inorganic filler, 40% by weight of concrete powder, and 40% by weight of polypropylene resin were kneaded until they became uniform while being heated to 230 ° C. with a kneader. The obtained kneaded material was molded by a press machine to obtain a test sample having a length of 400 mm, a width of 400 mm, and a thickness of 5 mm. The molding conditions at this time were the same as in Example 1.

Example 4
In Example 4, the inorganic filler was recovered using the same method as in Example 1 except that FRP coarsely pulverized to a size of 20 mm was used, and the test sample was prepared using the same method as in Example 1. Obtained.

  About each test sample obtained from the said Example, bending strength, Charpy impact strength, and specific gravity were evaluated. The bending strength was tested according to JIS standard K7171, the Charpy impact strength was tested according to JIS standard K7111, and the specific gravity was tested according to JIS standard K7112.

The obtained evaluation results are shown in Table 1.

  From the results shown in Table 1, the samples obtained in each example are not much different from the bending strength of 12 to 13 MPa and the specific gravity of 1.1 of the cement-made exterior material manufactured by the papermaking method generally used as the exterior material. As for the other items, it was found that there are no items that are greatly problematic in terms of physical properties, and that they can be used as resin exterior materials.

Claims (6)

  It is obtained by molding a kneaded product obtained by kneading a plastic containing at least an inorganic filler and a resin with a subcritical fluid and recovering the inorganic filler and a thermoplastic resin. Resin exterior material.   The resinous exterior material according to claim 1, wherein the inorganic filler is glass fiber or calcium carbonate.   The resin outer packaging material according to claim 1 or 2, wherein the plastic has an average particle size of 0.5 mm to 10 mm.   The said inorganic filler is mix | blended in the ratio of 10 weight%-40 weight% with respect to the total weight of an inorganic filler and a thermoplastic resin, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. The resin exterior material described.   The resinous exterior material according to any one of claims 1 to 4, wherein the inorganic filler is aluminum hydroxide.   The resin exterior material according to claim 1, wherein the resin contained in the plastic is an unsaturated polyester resin.