JP2013234240A - Method for recovering insoluble matter from composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recovering insoluble matter from a composite, which can improve economic efficiency and productivity without lowering characteristics of recycled products, by a method for recovering the insoluble matter from the composite containing a resin cured product and the insoluble matter without requiring a labor hour and a cost in a treatment of washing wastewater.SOLUTION: A method for recovering insoluble matter from a composite containing a resin cured product to be dissolved by at least a treatment liquid and the insoluble matter not to be dissolved by the treatment liquid includes a feed step of feeding the composite to a dissolution tank, a dissolution step of dissolving the resin cured product by the treatment liquid composed of an organic solvent and a catalyst stored in the dissolution tank, a solid-liquid separation step of separating the treatment liquid containing the resin cured product dissolved in the dissolution step from the undissolved insoluble matter, a recovery step of recovering the insoluble matter, a cleaning step of cleaning the insoluble matter with the organic solvent without using water and a drying step of drying the cleaned insoluble matter.

Description

  The present invention relates to a method for recovering insoluble matter that can recover and reuse insoluble matter that is insoluble in the processing liquid that constitutes the composite, and in particular, without reducing the properties of the recycled product, as well as economy and production. The present invention relates to a method for recovering insoluble matter from a composite, which can improve properties and the like.

In order to promote effective utilization of earth resources, it is extremely important to recycle waste materials or the like of composites (which are abbreviated as composites as appropriate) containing at least a cured resin and insoluble matter.
Examples of the composite include, for example, an epoxy resin cured product, a carbon fiber reinforced plastic including filler and carbon fiber (abbreviated as CFRP as appropriate), an unsaturated polyester resin cured product, a glass fiber reinforced plastic including filler and glass fiber. Plastic (appropriately abbreviated as GFRP), epoxy resin cured material, filler and mold coil containing metal parts (appropriately abbreviated as mold coil), conductive coil, filler and motor coil containing insulating varnish (appropriately Or a resin composite containing a urethane resin cured product and a polypropylene resin (abbreviated as a resin composite as appropriate). Since the amount of waste of the above composite waste is enormous, various technologies have been researched and developed for the purpose of recycling.

  For example, in Patent Document 1, as a method of recycling a composite composed of an epoxy resin cured product and an insoluble material, after treating with a treatment liquid containing a decomposition catalyst and an organic solvent, the epoxy resin cured product is decomposed and dissolved, A method for recovering insolubles is disclosed.

  Further, in Patent Document 2, as a method for recycling a composite comprising a cured unsaturated polyester resin and an insoluble material, the composite is treated with a treatment liquid containing a decomposition catalyst and an organic solvent, and the unsaturated polyester resin cured product is decomposed and dissolved. A method for recovering the insoluble matter after the treatment is disclosed.

  The complex dissolution treatment method according to the conventional example includes a complex introduction process, a dissolution process, a removal process, a washing process, and a drying process.

The composite is composed of at least a cured resin and an insoluble material.
Examples of the cured resin include at least one of an epoxy resin cured product, an unsaturated polyester resin cured product, a varnish, and a urethane resin cured product, and examples of the insoluble material include glass fiber, carbon fiber, conductive material, and conductive metal processing. Examples include at least one of a component and a polypropylene resin.

  The complex is charged into a dissolution tank in which the treatment liquid is stored, heated for a predetermined time to dissolve the cured resin, and then the insoluble matter remaining without being dissolved is recovered from the dissolution tank, washed, and dried. Thus, an insoluble material as a raw material for the recycled product can be obtained.

  The washing step is a step of washing and removing the decomposition product of the cured resin and the catalyst component contained in the treatment liquid, which are attached to the surface of the remaining insoluble matter. The cleaning liquid is substantially the same as the processing liquid, and an organic solvent that does not contain a dissolution promoting catalyst is used. After washing with the washing liquid, washing with water is performed.

JP 2001-172426 A JP 2002-194137 A

However, in the conventional dissolution treatment method, water washing is included in the washing process, and it takes time and cost to treat the washing wastewater generated thereby. The cleaning waste water cannot be discarded without being treated because the cleaning liquid or the like attached to the object to be cleaned is brought in and contaminated.
Also, in the course of the cleaning process, the resin solution or catalyst component dissolved in the processing liquid (as appropriate, abbreviated as impurities) is mixed in the cleaning liquid, so if the process is simply omitted, the impurities are insoluble. It may remain on the surface and deteriorate the properties of the recycled product.

  The present invention has been made to solve the above-described problems, and does not include water washing in the washing step, and the cured resin product does not require labor and cost for the treatment of the washing wastewater generated thereby. And a method for recovering insoluble matter from a composite that can improve economic efficiency and productivity without degrading the properties of the recycled product. For the purpose of provision.

In order to achieve the above object, the method for recovering an insoluble material from a composite according to the present invention includes: [1] at least an insoluble material from a composite containing a cured resin that is dissolved by a treatment liquid and an insoluble matter that is not dissolved by the treatment liquid; In the recovery method, in the charging step of charging the complex into the dissolution tank, the dissolution step of dissolving the resin cured product with a treatment liquid composed of an organic solvent and a catalyst stored in the dissolution tank, and the dissolution step A solid-liquid separation step for separating the treatment liquid containing the dissolved cured resin product from the insoluble matter that is not dissolved, a recovery step for collecting the insoluble matter, and water for the insoluble matter. And a washing step of washing with the organic solvent, and a drying step of drying the washed insoluble matter.
[2] The method for recovering insoluble matter from the complex according to [1] above, wherein in the washing step, the insoluble matter is washed at least once with the organic solvent in the washing step. About.
[3] The composite as described in [1] or [2] above, wherein in the washing step, if necessary, the insoluble matter is washed with the organic solvent and then drained. The present invention relates to a method for recovering insoluble matter from the body.
In the present invention, [4] the resin cured product is at least one selected from an epoxy resin cured product, an unsaturated polyester resin cured product, and a urethane resin cured product, and the insoluble material is a glass fiber or a carbon fiber. In addition, the present invention relates to a method for recovering an insoluble matter from a composite according to any one of [1] to [3], which is at least one selected from conductive materials, conductive metal processed parts, and polypropylene resins.
The present invention also provides [5] recovery of insoluble matter from the complex according to any one of [1] to [4] above, wherein the organic solvent is benzyl alcohol and the catalyst is tripotassium phosphate. Regarding the method.

  According to the method for recovering insoluble matter from the composite of the present invention, the washing process does not include water washing, and the characteristics of the recycled insoluble matter without requiring labor and cost for the treatment of the washing wastewater generated thereby. It is possible to improve economic efficiency and productivity without lowering.

FIG. 1: has shown the schematic flowchart figure for demonstrating the recovery method of the insoluble matter from the composite_body | complex concerning embodiment of this invention.

(Complex)
As described above, the composite of this embodiment is composed of at least a resin cured product and an insoluble material, and examples thereof include at least one of CFRP, GFRP, a molded coil, a motor coil, and a resin composite.
Examples of the cured resin include epoxy resins, unsaturated polyester resins, varnishes, and urethane resin cured products.
Examples of the insoluble material include at least one of glass fiber, carbon fiber, conductive material, conductive metal processed component, and thermoplastic resin such as polypropylene resin, polyethylene resin, and fluororesin.
Further, it is often desirable that the recovered insoluble matter is not pulverized or not finely pulverized in order to maintain and improve the value at the time of reuse. Therefore, in the present embodiment, a complex that is not pulverized or coarsely pulverized is stored in a container, and the dissolution treatment is performed in this state. Thereby, the cost regarding a grinding | pulverization can be reduced.

(Processing liquid)
The predetermined treatment liquid of this embodiment includes at least an organic solvent and a catalyst, and preferably includes benzyl alcohol as a solvent and tripotassium phosphate as a catalyst. Dissolve. Moreover, the liquid temperature of the processing liquid in the dissolution tank is controlled to a predetermined temperature. The control temperature is about 10 ° C. lower than the softening temperature of the insoluble matter in the composite and the boiling point of the treatment liquid.
The organic solvent of the treatment liquid is alcohols, ketones, carbonate compounds, heterocyclic compounds, esters, nitriles, aprotic polar substances, nonpolar solvents, chlorinated or cyclic / chain ethers Etc. Specifically, as alcohols, methanol, ethanol, isopropanol, ethylene glycol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, benzyl alcohol, etc. as ketones , Acetone, methyl ethyl ketone, methyl isobutyl ketone, DIBK (diisobutyl ketone), cyclohexanone, DAA (diacetone alcohol), etc. as carbonate compounds, ethylene carbonate, propylene carbonate, etc. as heterocyclic compounds, 3-methyl-2 -Oxazolidinone, N-methylpyrrolidone and the like are esters such as carboxylic acid ester, phosphate ester, phosphoester Acid esters etc. are nitriles such as acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, etc., and aprotic polar substances such as dimethyl sulfoxide, sulfolane, dimethylformamide, dimethylacetamide etc. Solvents such as toluene, xylene and the like, chlorine-based compounds such as methylene chloride and ethylene chloride, cyclic and chain ethers, cyclic ethers such as dioxane and tetrahydrofuran, chain ethers such as diethyl ether, Examples include ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, and polypropylene glycol dialkyl ether.

The catalyst may contain an alkali metal hydroxide, phosphate, or carbonate. By doing so, the cured resin can be dissolved in a short time even under atmospheric pressure. Therefore, since a pressure-resistant structure or the like is not required, the equipment cost can be reduced, the time until melting can be shortened, and the running cost can be reduced.
Examples of alkali metal hydroxides, phosphates or carbonates include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, lithium phosphate, sodium phosphate, potassium phosphate, rubidium phosphate, Or potassium carbonate is mentioned.
In addition, dissolution of the cured resin by the treatment liquid includes swelling of the cured resin by the treatment liquid, decomposition of the cured resin, peeling from the composite of the cured resin, dissolution of the resin decomposition product in the treatment liquid, and the like. It is.

(Input process)
The charging process is a process of charging the complex into the dissolution tank (step S1).
Examples of the input means include means for supplying a container in which the composite is previously stored into the dissolution tank by moving means such as a conveyor and lifting means such as a crane. The container has a rectangular shape in which a punching metal, an expanded metal, a wire mesh, or the like is attached to a frame. By using such a container, even when the shape and size of the complex before the dissolution treatment and the insoluble matter after the dissolution treatment are various, it is possible to efficiently input, transport, and take out. The shape of the container is not limited to the above, and the mesh size and the opening ratio are appropriately set according to the shape and size of the insoluble matter.
Further, there is a means for charging the complex into the dissolution tank from a hopper connected to the dissolution tank. This is an effective means in situations where the composite is crushed.

(Dissolution process)
The dissolution step is a step in which the cured resin in the input composite is decomposed by the treatment liquid stored in the dissolution tank and dissolved in the treatment liquid (step S2). At this time, the temperature of the treatment liquid in the dissolution tank is controlled to a predetermined temperature. The control temperature is about 10 ° C. lower than the softening temperature of the insoluble matter in the composite and the boiling point of the treatment liquid. If necessary, in order to improve the dissolution efficiency of the cured resin product, the treatment liquid may be stirred, or an inert gas may be introduced into the treatment liquid and bubbled.

(Solid-liquid separation process)
The solid-liquid separation step is a step of separating the treatment liquid in which the decomposition product of the cured resin in the composite is dissolved and the insoluble matter (step S3).
As means for solid-liquid separation, the container containing the complex is lifted from the dissolution tank by moving means such as a conveyor and lifting means such as a crane, and the insoluble matter remaining in the container is emptied into the washing tank. A means for discharging insoluble matter to a net conveyor having a liquid receiving container in the lower part and transporting it to a washing tank can be mentioned.
The treatment liquid obtained by dissolving the decomposed product of the cured resin obtained in the solid-liquid separation step is returned to the dissolution tank again and can be used as a replacement for a new treatment liquid until the treatment capacity is significantly reduced.

(Washing process)
The cleaning process is a process of removing impurities with a cleaning liquid (step S4).
The cleaning liquid is substantially the same as the processing liquid, and an organic solvent that does not contain water and a dissolution promoting catalyst is used. This makes it possible to recycle the organic solvent used for washing by means such as distillation without requiring labor and cost for the treatment of washing wastewater, and use it as a raw material for the treatment liquid, thereby reducing the raw material cost. Can do. Washing is performed a plurality of times as necessary.
Moreover, after washing | cleaning of an organic solvent, liquid removal is performed as needed. By performing the liquid removal, it is possible to remove as much as possible the cleaning liquid in which impurities are mixed, and it is possible to prevent impurities from remaining on the surface of the insoluble matter.
It is also effective to perform the liquid removal step (step S4 ′) immediately before the cleaning step for the purpose of minimizing the entry of impurities into the cleaning solution and extending the life of the cleaning solution. Examples of the liquid removal means include a centrifugal liquid removal machine and a manual basket type liquid removal machine. In the case of using an electric device, for the sake of safety, means such as the use of an explosion-proof device and purging the motor part with an inert gas are required.

(Drying process)
A drying process is a process of drying the organic solvent adhering to the surface of an insoluble matter, and the organic solvent impregnated inside the insoluble matter (step S5). Drying is performed below the softening temperature of the insoluble material. In addition, by purging the inert gas, the atmosphere is controlled so that the solvent gas concentration is equal to or lower than the lower explosion limit concentration. The insoluble matter obtained in the drying process is recovered and used as a raw material for recycled products.

  Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited thereto.

The sample, the treatment liquid, and the dissolution conditions were common to both Example 1 and Comparative Example 1.
(sample)
As a composite to be dissolved, 100 g of a 10 mm diameter screen mesh pass pulverized product of a urethane resin cured product as a resin cured product and a polypropylene resin resin composite as an insoluble material was used.

(Processing liquid)
A treatment solution consisting of 300 g of benzyl alcohol as a solvent component and 22 g of tripotassium phosphate as a catalyst component was used.

(Dissolution conditions)
The complex and the treatment liquid were housed in a four-necked flask, and a thermometer, a stirrer, a reflux condenser, and a nitrogen introduction tube were attached to the flask, and heated for 30 minutes in the range of 140 ° C. to 150 ° C. using an oil bath.

(Insoluble matter recovery conditions)
After the resin composite is dissolved by the above method, the temperature of the treatment liquid is lowered to 100 ° C. or lower, which is the flash point of benzyl alcohol, and then the contents of the flask are emptied into a stainless steel draining colander with an opening of 2 mm square. It isolate | separated into the processing liquid in which the resin cured material melt | dissolved, and the polypropylene resin which remained without melt | dissolving.

(Comparative Example 1)
The polypropylene resin obtained after the dissolution treatment was immersed in benzyl alcohol as a cleaning solution and stirred for 10 minutes. Washing with benzyl alcohol was performed twice in total.
The washing liquid and the polypropylene resin were separated by a stainless draining colander with a 2 mm square, and the polypropylene resin was collected again, immersed in water, and stirred for 10 minutes. Washing with water was performed once. Note that 4.0 g of benzyl alcohol is dissolved in 100 g of water at 20 ° C.
Washing water and polypropylene resin were separated by a stainless draining colander with 2 mm squares, and the recovered polypropylene resin was dried for 180 minutes in a drier kept at 145 ° C.
25 g of the dried polypropylene resin was put into 100 g of pure water and stirred for 30 minutes to obtain a filtrate from which the cleaning residue adhering to the polypropylene resin surface was extracted. As an indicator of the catalyst component in the filtrate, the concentration of potassium ions derived from tripotassium phosphate was measured using an atomic absorption photometer (Z-5010, manufactured by Hitachi High-Tech Fielding), and the content of organic substances derived from the solvent and dissolved resin was measured according to JIS K 0102 22 According to (combustion oxidation-infrared analysis method), it was quantified with a TOC (total organic carbon) analyzer. The results are shown in Table 1.

(Example 1)
The polypropylene resin obtained after the dissolution treatment was immersed in benzyl alcohol as a cleaning solution and stirred for 10 minutes. Washing with benzyl alcohol was performed three times in total.
Since the polypropylene resin easily adheres to the washing liquid and does not easily break, the liquid was removed after washing. The washing solution and the polypropylene resin were separated by a stainless draining colander with a 2 mm square, and the collected polypropylene resin was drained using a small centrifuge (Hokusan H-112). The liquid removal was performed at 4000 rpm for 3 minutes.
Thereafter, the polypropylene resin was recovered from the small centrifuge and dried in a dryer maintained at 145 ° C. for 180 minutes.
The washing residue was quantified in the same manner as in Comparative Example 1. The results are shown in Table 1.

(Comparative Example 2)
As Comparative Example 2, the same analysis as in Example 1 and Comparative Example 1 was performed on the virgin material of polypropylene resin without performing the dissolution treatment. The results are shown in Table 1.

As shown in Example 1 and Comparative Example 1, it was found that even when water cleaning was omitted in the cleaning process, the cleaning level was almost the same as when water cleaning was performed. Tripotassium phosphate used as a catalyst dissolves in alcohol, but 90 g dissolves in 100 g of water at 20 ° C. Therefore, in the water washing of Comparative Example 1, potassium ions are slightly lowered, but are not washed with water. Then, the total amount of organic carbon becomes smaller, and it is effective as a recycled product.
Recycled polypropylene resin properties include Charpy impact value and melt flow rate. Recycled products that have been washed with water and those that have been washed only with a solvent maintain almost the same properties as virgin materials. did.

Claims (5)

A method for recovering insoluble matter from a composite including at least a resin cured product that is dissolved by a treatment liquid and an insoluble matter that is not dissolved by the treatment liquid,
A charging step of charging the complex into a dissolution tank;
A dissolution step of dissolving the resin cured product with a treatment liquid comprising an organic solvent and a catalyst stored in a dissolution tank;
In the dissolution step, a solid-liquid separation step for separating the treatment liquid containing the dissolved cured resin and the insoluble matter not dissolved,
A recovery step of recovering the insoluble matter;
A washing step of washing the insoluble matter with the organic solvent without using water; and
And a drying step of drying the washed insoluble matter. A method for recovering insoluble matter from the composite.   The method for recovering insoluble matter from a complex according to claim 1, wherein in the washing step, the insoluble matter is washed with the organic solvent at least once.   3. The method for recovering insoluble matter from a complex according to claim 1 or 2, wherein, in the washing step, if necessary, the insoluble matter is washed with the organic solvent and then drained.   The cured resin is at least one selected from an epoxy resin cured product, an unsaturated polyester resin cured product, and a urethane resin cured product, and the insoluble material is glass fiber, carbon fiber, conductive material, conductive metal processed component, and The method for recovering insoluble matter from the composite according to any one of claims 1 to 3, wherein the method is at least one selected from polypropylene resins.   The method for recovering insoluble matter from a complex according to any one of claims 1 to 4, wherein the organic solvent is benzyl alcohol and the catalyst is tripotassium phosphate.

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