JP5095301B2 - Plastic waste disposal method - Google Patents

Description

  The present invention relates to a plastic waste processing method, and more particularly to a plastic waste processing method capable of efficiently removing halogen atoms from a plastic waste containing halogen atoms in a short time.

  Various plastic products are easy to mold and excellent in properties such as strength, and are widely used in various applications. These plastic products will eventually be discarded and disposed of. Since plastic waste discarded from plastic products used in a wide range of applications is diverse and the amount of waste is enormous, disposal of plastic waste has become an important issue. For the disposal of plastic waste, incineration or landfill disposal is usually employed.

  However, when plastic waste containing plastic waste containing halogen atoms is simply incinerated, halogen-containing materials such as halogen gas and hydrogen halide are generated. If it does so, it will become easy to generate | occur | produce dioxins not only to injure an incinerator with the halogen-containing material etc. which were generated. Further, when plastic waste containing plastic waste such as polyurethane and acrylonitrile-butadiene-styrene copolymer (ABS) is simply incinerated, harmful gases such as cyanogen are generated.

  Examples of a method for capturing halogen-containing substances or toxic gases generated by incineration, for example, a method using an incinerator equipped with a filter capable of capturing halogen-containing substances or toxic gases, etc., plastic waste containing halogen atoms Is incinerated with slaked lime. Examples of methods for preventing the generation of halogen-containing substances or toxic gases include, for example, methods for separating plastic waste containing halogen atoms contained in plastic waste or plastic waste such as polyurethane and ABS. It is done.

  However, when a filter or the like is attached to the incineration facility, the incineration facility becomes large, and the disposal cost increases. In addition, it is difficult to separate plastic products as desired, and if plastic waste to be incinerated contains plastic products used for medical equipment, for example, secondary infection There are also hygiene issues.

  If plastic waste is simply landfilled instead of incineration having such problems, the environment in the vicinity of the plastic waste landfill is destroyed, and eventually, the negative impact on people and the environment is increased.

  Therefore, a waste disposal method for plastic waste, particularly plastic waste containing halogen atoms, which can solve at least one of these problems is desired.

  As a method that can meet this demand, for example, “a solution obtained by dissolving a vinyl chloride polymer composition in an organic solvent and adding an alkali agent to this solution is stirred at normal pressure from normal temperature to the boiling point of the organic solvent. And a method in which the vinyl chloride polymer in the vinyl chloride polymer composition is dechlorinated by holding it in the temperature range up to and including stirring (see Patent Document 1). However, in the method described in Patent Document 1, in order to achieve a dechlorination rate of 97.2%, the polarity for dissolving the vinyl chloride polymer composition is described as described in the examples. Using dimethyl sulfoxide as an aprotic solvent, a reaction time as long as 3 hours is required at a reaction temperature of 80 ° C.

  Further, as another method to meet the above-mentioned demand, “a heat treatment step of heat-treating plastic waste containing sulfur and / or halogen with an alkaline solution, and a liquid material extracted from the treatment mixture treated in this heat treatment step” The present applicant has proposed a method for treating plastic waste characterized by comprising a light irradiation step of performing light irradiation treatment in the presence of a photocatalyst (see Patent Document 2).

JP 2003-253039 A JP 2004-123883 A

  An object of the present invention is to provide a plastic waste processing method capable of efficiently removing halogen atoms from plastic waste containing halogen atoms in a short time.

As means for solving the problems,
Claim 1 is a plastic waste containing halogen atoms, an amino compound in which the total amino group amount per 100 g of the plastic waste is the following molar amount, and 2500 to 50000 with respect to 100 parts by mass of the plastic waste. A method for treating plastic waste, characterized by heat-treating a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution having a concentration of 0.1 to 3.5 mol / L in mass parts to 150 to 250 ° C.
When the amino compound is 2-aminoethanol : 0.5 to 50 mol When the amino compound is hydrazine : 10 to 35 mol When the amino compound is ammonia : 55 to 150 mol The amino compound is trimethylamine . In some cases: 4 to 30 mol Claim 2 is the plastic waste according to claim 1, wherein the plastic waste is soft polyvinyl chloride having a halogen atom content of 3 mol / g or less. Processing method ,
A third aspect of the present invention is the plastic waste processing method according to the first or second aspect , wherein the heat treatment is performed for at least 20 minutes .

  According to the plastic waste processing method of the present invention, the plastic waste containing halogen atoms is heat-treated at a specific temperature together with a specific amount of an amino compound or an amino compound precursor and a specific concentration of an alkaline solution, Halogen atoms can be removed from plastic waste containing halogen atoms in a short time and at a low cost. Further, according to the plastic waste processing method according to the present invention, even if the amino compound or amino compound precursor waste is mixed in the plastic waste containing halogen atoms, the amino compound or amino compound There is also no need to strictly separate the precursor waste. Therefore, according to this invention, the processing method of the plastic waste which can remove a halogen atom efficiently from the plastic waste containing a halogen atom in a short time can be provided.

  And since the halogen atom is removed, the processed material obtained by the plastic waste processing method according to the present invention can be recycled as an industrial raw material, and is finally incinerated. In any case, it is possible to prevent damage to the incinerator and generation of harmful substances such as dioxins.

  There are a wide variety of plastics that are widely used in general society, and various additives such as plasticizers, stabilizers, antioxidants, ultraviolet absorbers, flame retardants, and antistatic agents are used depending on the application of the plastic product. , Lubricants, colorants, etc. The plastic waste processing method according to the present invention (hereinafter sometimes referred to as the method of the present invention) includes a plastic waste containing halogen atoms and / or molecules by containing the various additives. It is suitable for the treatment of plastic waste containing halogen atoms. Accordingly, the plastic waste treated by the method of the present invention may be any plastic waste containing halogen atoms.

  Although it is an example of the plastic containing a halogen atom, as a plastic containing a halogen atom in a molecule | numerator, if it has a halogen atom in the molecule | numerator, it will not specifically limit, For example, a fluororesin , Vinyl chloride resin, chloroprene resin, vinylidene fluoride resin, ethylene chloride trifluoride resin, and the like. Among these, a vinyl chloride resin is advantageous for applying the method of the present invention because a halogen atom can be removed in a short time. Examples of the vinyl chloride resin include vinylidene chloride resin, vinyl chloride resin, vinyl chloride vinyl acetate copolymer resin, vinyl chloride vinylidene chloride copolymer resin, vinyl chloride acrylate, vinyl chloride methacrylate copolymer resin, vinyl chloride acrylic. Examples include nitrile copolymers, ethylene vinyl chloride copolymers, and propylene vinyl chloride copolymers.

  As an example of plastics containing halogen atoms, plastics containing halogen atoms by containing various additives include additives that do not contain halogen atoms in the plastic molecule but contain halogen atoms. Plastic containing an agent (To be exact, it should be referred to as a resin composition containing an additive containing a halogen atom. In the present invention, a resin composition containing such an additive is used. May also be referred to as “plastic”). The additive containing a halogen atom is not particularly limited as long as it has a halogen atom in the molecule. For example, dimethyl pentachloride stearate, trichloroethyl phosphate, trisdichloropropyl phosphate, trisdibromo Plasticizers such as propyl phosphate, antioxidants such as monoalkylene dibromophenol, flame retardants such as tris (chloroethyl) phosphate, perchloropentacyclodecane, tetrabromobutane, tetrabromobisphenol A, tetrabromoethane, decabromobiphenyl ether Etc. Moreover, as an additive containing a halogen atom in the molecule, in addition to the additive, “New Edition / Plastic Compounding Agent—Basics and Applications” published on January 30, 1984, published by Taiseisha Various additives are mentioned.

  The plastic containing a halogen atom only needs to contain, for example, a plastic containing a halogen atom in the molecule or an additive containing the halogen atom, and a plastic containing a halogen atom in the molecule. And an additive containing the halogen atom, and further containing at least one plastic containing a halogen atom by containing at least one additive containing the halogen atom, and at least one kind And a plastic containing a halogen atom in the molecule.

  According to the present invention, if the halogen atom content in the plastic containing halogen atoms is less than 0.5 mol / g, the halogen atoms can be efficiently removed from the plastic in a very short time. Furthermore, according to the present invention, conventionally, a plastic having a halogen atom content of 0.5 mol / g or more, which has been difficult to remove halogen atoms at a high removal rate even if it takes a long time, such as 0.5 to Even with a plastic of 3 mol / g (especially 1 to 2 mol / g), halogen atoms can be efficiently removed in a short time from such a plastic having a high halogen atom content. However, in the present invention, a plastic having a halogen atom content exceeding 3 mol / g can be used as long as the treatment time may be somewhat longer.

  An object to be treated by the method of the present invention is a plastic waste containing halogen atoms (hereinafter sometimes referred to as a halogen atom-containing plastic waste). This halogen atom-containing plastic waste is a molding plastic containing at least one of a plastic containing a halogen atom in a molecule and a plastic containing a halogen atom by containing various additives. Disposable without being used as a product, scraped burrs and by-products such as punching residue generated by molding with the molding plastic, and molded with the molding plastic Halogen-containing plastic products that are discarded after use, and assembled products that are a combination of the halogen-containing plastic products and resin products obtained using other resins, and the halogens separated from the assembled products Examples include those in which the contained plastic products are discarded.

  Examples of the halogen atom-containing plastic waste include medical equipment, automotive products, packaging products such as cushioning materials, artificial leather, heat insulating materials, adhesives, and paints. Medical devices include, for example, blood purification devices, syringes (injection cylinders), plastic indwelling needles, infusion sets, filters, disposable portable medical fluid injectors, etc. “Considering the administration method” (published March 15, 2001, 1st edition, 1st edition, written by Fumiharu Kobo, published by Medical Tribune Co., Ltd.), various plastic medical devices, blood transfusion / blood bags, surgical gloves, Examples thereof include a fluid circulation tube for circulating a body fluid such as blood or a therapeutic liquid, a blood purifier, and the like. Examples of automotive products include automotive bumpers, automotive seats, dashboards, automotive synthetic leather, automotive insulation, automotive cushioning materials, automotive component adhesives, and paints. In addition, although various names are illustrated as plastic products, the medical devices, automobile products, etc. are not all made of plastic, and part or most of them are made of plastic. including.

  The halogen atom-containing plastic waste can be provided to the method of the present invention as it is when it is discarded and recovered. If the purpose is to remove halogen atoms from halogen-containing plastic waste in a shorter time, the halogen-containing plastic waste is subjected to the method of the present invention as a pulverized product or a crushed product by pulverizing or crushing the halogen-containing plastic waste product. Is good. The size of the pulverized product or crushed product is not particularly limited, and may be adjusted to several hundred μm to several cm, for example.

  In the method of the present invention, the halogen-containing plastic waste can be used singly or in combination of two or more.

  The amino compound or amino compound precursor used in the method of the present invention contributes to removing halogen atoms from the halogen atom-containing plastic waste in the heat treatment in an alkaline solution described later.

  The amino compound may be a compound having at least one of an amino group (including a tertiary amino group) and an imino group in the molecule, such as an aromatic amino compound, an aliphatic amino compound, and an alicyclic amino group. Compounds, inorganic amino compounds and the like. Among these, aliphatic amino compounds, alicyclic amino compounds, or inorganic amino compounds are preferred and available in that they are very unlikely to generate harmful substances such as dioxins when the treatment mixture after heat treatment is incinerated. In view of easiness and cost, inorganic amino compounds are particularly preferable.

  Examples of the aromatic amino compound include aniline, benzamine, benzylamine, phenethylamine, toluidine, aminophenol, phenylenediamine, and the like. Examples of the aliphatic amino compound include methylamine, ethylenediamine, isopropylamine, trimethylamine, triethylamine, ethyleneimine, hexamethylenediamine, 1-ethanolamine, 2-ethanolamine, and allylamine. Examples of the alicyclic amino compound include cyclohexylamine and the like. Examples of the inorganic amino compound include ammonia, aqueous ammonia, hydrazine, and the like.

  The amino compound may be a monoamino compound having at least one amino group or imino group in the molecule, a diamino compound having two amino groups or the like, or a polyamino compound having three or more amino groups or the like. Good. When a diamino compound or a polyamino compound is selected as the amino compound, the amount used can be reduced. On the other hand, when a monoamino compound is selected as the amino compound, it can be easily obtained and the processing cost can be reduced.

  The amino compound precursor may be a compound that generates or liberates an amino group or an imino group under the conditions of a heat treatment in an alkaline solution described later. For example, a blocked isocyanate compound, polyurethane, polyamide, polyimide, and polyamideimide Etc.

  The blocked isocyanate compound is a compound in which an isocyanate group is protected with a blocking agent. Under the heat treatment conditions described later, the blocking agent is released by heating or hydrolysis to produce an isocyanate compound. Next, the produced isocyanate compound is hydrolyzed to produce an amino compound. Examples of the isocyanate compound that forms the blocked isocyanate compound include aliphatic polyisocyanates and aromatic polyisocyanates. Examples of the aromatic polyisocyanate include xylylene diisocyanate (XDI), diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate (NDI), paraphenylene diisocyanate (PDI), and tolidine diisocyanate (TODI). It is done. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), norbornane diisocyanate methyl, transcyclohexane-1,4-diisocyanate, and hydrogenated MDI. As the blocking agent for forming the blocked isocyanate compound, any blocking agent usually used for protecting the isocyanate group may be used. For example, ε-caprolactams, methyl ethyl ketoximes, 3,5-dimethylpyrazoles, alcohols and phenols Etc. Examples of the blocking agent include isocyanates. In this case, the blocked polyisocyanate is a polyisocyanate dimer (polyuretdione).

  The polyurethane is a polymer having a urethane bond formed by reacting a polyol and a polyisocyanate. Polyurethane is hydrolyzed under the heat treatment conditions described later, and the polyisocyanate produced by hydrolysis is further hydrolyzed to produce a polyamino compound. The polyurethane may be a modified polyurethane using a polyamine or the like as a part of polyisocyanate. The polyisocyanate forming the polyurethane may be any of various polyisocyanates usually used for preparation of polyurethane. Examples thereof include the above-described aliphatic polyisocyanates and the above-described aromatic polyisocyanates. The polyol forming the polyurethane may be any of various polyols usually used for preparation of polyurethane, and examples thereof include polyether polyol and polyester polyol.

  The polyamide may be a polymer having an acid amide bond (—CONH—) in a repeating unit, and among them, a polyamide obtained by polycondensation of a diamino compound and a dicarboxylic acid is preferable. Polyamide, particularly polyamide obtained by polycondensation of a diamino compound and a dicarboxylic acid, is hydrolyzed under the heat treatment conditions described later to produce a diamino compound. Examples of such polyamides include polyamide 6-6, polyamide 6-10, polyamide 6-12, polyamide MXD6, and the like.

  The polyimide may be a polymer having an imide bond in a repeating unit, and among them, a condensation type polyimide obtained by condensing an acid anhydride and a diamino compound is preferable. Examples of the condensation type polyimide include a polyimide obtained by condensing pyromellitic acid anhydride and an aromatic diamino compound such as diaminodiphenyl ether. Polyimide, especially condensation-type polyimide, is hydrolyzed under the heat treatment conditions described later to produce an aromatic diamino compound.

  The polyamidoimide may be a polymer having an imide bond and an amide bond in the repeating unit, and is a polyisocyanate obtained by reacting a tricarboxylic acid and an aromatic diamino compound, a diisocyanate for reacting a tricarboxylic acid anhydride and a diisocyanate compound. Examples thereof include polyamideimide obtained by the method. Polyamideimide is hydrolyzed under the heat treatment conditions described below to produce a diamino compound in which an aromatic diamino compound or a diisocyanate compound is hydrolyzed.

  The polyurethane, the polyamide, the polyimide and the polyamideimide each have various kinds of additives such as a plasticizer, a wax, a stabilizer, an ultraviolet absorber, a reinforcing agent, which may or may not have a halogen atom in the molecule. Polyurethanes, polyamides, polyimides and polyamideimides containing flame retardants, antistatic agents, etc. (more precisely, polyurethane compositions, polyamide compositions, polyimide compositions and polyamideimide compositions containing various additives) In the present invention, the polyurethane composition, the polyamide composition, the polyimide composition and the polyamideimide composition containing such an additive are also referred to as “polyurethane, polyamide, polyimide and It may be referred to as “polyamideimide”.

  The amino compound or amino compound precursor used in the method of the present invention may be an amino compound or amino compound precursor before use, or may be a waste of an amino compound or amino compound precursor. . Considering the processing cost and the like in the method of the present invention, the object to be processed by the method of the present invention is advantageously an amino compound or amino compound precursor waste. Examples of the amino compound or amino compound precursor before use include an amino compound or amino compound precursor prepared or prepared for treatment by the method of the present invention. Examples of the amino compound waste include amino compounds that are no longer needed and discarded, and amino compounds that are recovered and used in various synthetic reactions such as functional group protection and deprotection reactions. The waste of the amino compound precursor is various molding polyurethanes, various molding polyamides, various molding polyimides or various molding polyamide imides (hereinafter sometimes referred to as various molding polyurethanes, etc.), and products. Disposable without being used as a product, discarded from burrs and punching residue, etc. produced as a by-product when molded using the above-mentioned various molding polyurethanes, molded using the above-mentioned various molding polyurethanes, etc. Various products obtained by processing, which are discarded after use, and assembled products obtained by combining the various products with resin products obtained using other resins, and various products separated from the assembled products. Examples of such products are discarded. For example, the waste of polyurethane as the amino compound precursor waste includes automobile bumpers, automobile seats, dashboards, automobile artificial leather, automotive heat insulating materials, automotive cushioning materials, and automotive component adhesives. Alternatively, automotive products such as paint, packing products such as cushioning materials, and the like can be given. In addition, although various names have been exemplified as the waste of polyurethane, the automobile products and the like are not necessarily all made of polyurethane, and some or most of them are made of polyurethane. Including.

  The amino compound or amino compound precursor, particularly the amino compound precursor, can be provided to the method of the present invention as it is when it is prepared or discarded and recovered. If it is intended to remove halogen atoms from halogen-containing plastic waste in a shorter time, it can be used as a pulverized product or a crushed product by pulverizing or crushing an amino compound or amino compound precursor. It is good to serve. The size of the pulverized product or crushed product is not particularly limited, and may be adjusted to several hundred μm to several cm, for example.

  In the method of this invention, an amino compound or an amino compound precursor can be used individually by 1 type or in combination of 2 or more types.

  The amount of the amino compound or amino compound precursor used is 100% by weight of amino acid with respect to 100 parts by mass of the halogen atom-containing plastic waste in the reaction system containing the halogen atom-containing plastic waste and the alkaline solution under the heat treatment conditions described later. The total mass of groups (including amino groups generated under heat treatment conditions described later) (sometimes referred to as the total amino group amount in this invention) is 0.5 mass or more. In other words, the amount of total amino groups present in the reaction system under the heat treatment conditions described below is less than 0.5 mol, in other words, the mass of amino having a total amino group amount present in the reaction system of less than 0.5 mol. If only a compound or an amino compound precursor is used, halogen atoms may not be removed from halogen atom-containing plastic waste in a short time with a high removal rate. In the method of the present invention, the amount of the amino compound or amino compound precursor used is preferably a mass in which the total amount of amino groups present in the reaction system is 5 mol or more, and a mass in which 12 mol or more exists. More preferably, the mass is more preferably 20 mol or more. On the other hand, in the method of the present invention, the upper limit of the amount of amino compound or amino compound precursor used is not particularly limited, but can be set to a mass at which the total amino group amount is about 50 mol, for example. If the amount of amino compound or amino compound precursor used exceeds this mass, the amount of amino compound or amino compound precursor used may increase, resulting in an increase in cost and workability, and a halogen atom-containing plastic. In rare cases, the removal rate of halogen atoms from waste is reduced. In the method of the present invention, the upper limit of the amount of the amino compound or amino compound precursor used is, for example, 45 mol of the total amino group present in the reaction system, depending on the type of amino compound or amino compound precursor. It can be set to a mass that becomes or a mass that becomes 40 mol.

  The total amount of amino groups present in the reaction system is, for example, considering the dissociation state of the amino compound or amino compound precursor in the reaction system, and more specifically, the volatility of the amino compound or amino compound precursor ( In consideration of the state of volatility), liquid or gas, the capacity of the reaction vessel, and the like, it can be adjusted to the above range. For example, if the amino compound or amino compound precursor has almost no volatile property (volatility) such as 2-aminoethanol, most of it exists in the reaction system during the reaction. For example, the amount of the amino compound or amino compound precursor used may be a mass such that the total amino group amount is 0.5 mol or more with respect to 100 parts by mass of the halogen atom-containing plastic waste. On the other hand, if the amino compound or amino compound precursor has properties such as volatility (volatile, fuming), etc., and part or most of it is difficult to exist in the reaction system under the heat treatment conditions described below, Considering these properties and the degree thereof, the amount of amino compound or amino compound precursor used is such that the total amino group amount is 0.5 mol or more per 100 parts by mass of the halogen atom-containing plastic waste. What is necessary is just to use an excess amount rather than mass.

  Specifically, when the amino compound is a smoking compound such as hydrazine, for example, if hydrazine or the like is used in such an amount that the total amino group amount is 10 mol or more, preferably 12 mol or more, particularly preferably 20 mol or more. Good. The upper limit of the amount of hydrazine used can be set, for example, such that the total amino group amount is 35 mol or less, preferably 33 mol or less, particularly preferably 30 mol or less. In the case where the amino compound is a volatile compound such as ammonia water, for example, ammonia water having an amount of total amino group of 55 mol or more, preferably 65 mol or more, particularly preferably 80 mol or more may be used. . The upper limit of the usage amount of ammonia water or the like can be set, for example, such that the total amino group amount is 150 mol or less, preferably 130 mol or less, particularly preferably 125 mol or less. Further, when the amino compound is a gas such as trimethylamine, for example, trimethylamine or the like in such an amount that the total amino group amount is 4 mol or more, preferably 5 mol or more, particularly preferably 6 mol or more may be used. The upper limit of the amount used such as trimethylamine can be set, for example, such that the total amino group amount is 30 mol or less, preferably 20 mol or less, particularly preferably 15 mol or less.

  In the amino compound precursor, in addition to or instead of the total amino group amount, the amount of the amino compound precursor used is adjusted to 2 to 20 parts by mass with respect to 100 parts by mass of the halogen atom-containing plastic waste. You can also If the amount of polyurethane used is less than 2 parts by mass, it may not be possible to remove halogen atoms from halogen atom-containing plastic waste at a high removal rate in a short time. In the method of the present invention, the upper limit of the amount of amino compound precursor used is not particularly limited. However, if the amount exceeds 20 parts by mass, the amount of amino compound or amino compound precursor used increases, resulting in increased costs and workability. In some cases, the removal rate of halogen atoms from the plastic waste containing halogen atoms may be reduced. The amino compound precursor is used in an amount of 100 parts by mass of the halogen atom-containing plastic waste because it is low in cost and excellent in workability and can remove halogen atoms from the halogen atom-containing plastic waste at a high removal rate. The amount is preferably 3 to 8 parts by mass, particularly preferably 4 to 6 parts by mass.

  The object to be treated in the method of the present invention is a halogen atom-containing plastic waste, but in the method of the present invention, a mixture of a halogen atom-containing plastic waste and an amino compound or an amino compound precursor is treated. It can be an object. Examples of such a mixture include a mixed waste in which a plastic containing a halogen atom and an amino compound or an amino compound precursor are discarded without being separated. When a mixed waste is selected as an object to be treated by the method of the present invention, a halogen-containing plastic and an amino compound are mixed with the halogen-containing plastic and the amino compound or the amino compound precursor, which are discarded without being separated. This is advantageous in that it does not require an operation of separating the compound or the amino compound precursor from each other.

  As an alkaline solution used for the method of this invention, the aqueous solution which melt | dissolves strong alkalis, such as sodium hydroxide and potassium hydroxide, is mentioned, for example. The alkali concentration in the alkaline solution is 0.1 to 3.5 mol / L, preferably 0.5 to 3 mol / L, and particularly preferably 0.8 to 2.5 mol / L. Even if the alkali concentration is less than 0.1 mol / L or more than 3.5 mol / L, halogen atoms may not be efficiently removed from the halogen atom-containing plastic waste in a short time.

  Although the usage-amount of an alkaline solution is not specifically limited, For example, it is preferable that it is 2,500-50,000 mass parts with respect to 100 mass parts of halogen-containing plastic waste. When the amount of the alkaline solution used is less than 2,500 parts by mass, halogen atoms may not be efficiently removed from the halogen atom-containing plastic waste in a short time, while when the amount exceeds 50,000 parts by mass. , Processing capacity may decrease.

  In the method of the present invention, 100 parts by mass of a halogen-containing plastic waste, an amino compound or amino compound precursor having a mass such that the amount of amino groups is 0.5 mol or more, and an alkali concentration of 0.1 to 3.5 mol / An appropriate amount of the alkaline solution of L (the amount used) is heated to 150 to 250 ° C. under a pressure of normal pressure to 30 atm. If the heating temperature is lower than 150 ° C., halogen atoms may not be removed from the halogen-containing plastic waste in a short time. On the other hand, if the heating temperature exceeds 250 ° C., the intramolecular content contained in the halogen-containing plastic waste In some cases, plastics containing halogen atoms may be thermally decomposed. The heating temperature is preferably 190 to 230 ° C., and particularly preferably 180 to 200 ° C., in that halogen atoms can be removed from the halogen atom-containing plastic waste with a high removal rate in a short time. .

  The heating time depends on the concentration of strong alkali in the alkaline solution and cannot be determined unconditionally. In general, however, in order to remove halogen atoms from halogen atom-containing plastic waste at a high removal rate, for example, at a predetermined heating temperature. After reaching, it should be at least 20 minutes, usually about 40-60 minutes. In addition, when using the microwave heating means mentioned later, the heating time in heat processing can be shortened, for example, about 20 to 30 minutes are enough.

  The heating condition is an example, and if the purpose is to perform the heat treatment quickly, it is better to perform the treatment at a high pressure and a high temperature. However, the heating condition does not increase the equipment cost. Industrial implementation can be performed. However, if treatment time may be taken, the heat treatment can be performed at a normal pressure and a temperature not higher than the boiling point.

  The heating means for heat-treating the mixture of the halogen-containing plastic waste and the amino compound or the amino compound precursor and the alkaline solution is not particularly limited, and for example, an electric heater, hot water or steam, or a heating medium is also possible. However, a microwave heating means is preferable for performing an efficient heat treatment in a short time. In particular, since plastics containing halogen atoms have a large relative dielectric constant and dielectric loss tangent, which are measures of ease of heating, the microwave heating means allows halogen atoms to be removed even when the temperature of the entire system is relatively low. Dehalogenation of the contained plastic proceeds rapidly. Therefore, according to the microwave heating means, the heat treatment temperature can be lowered, the heat treatment time can be shortened, and the concentration of the alkaline solution used for the heat treatment can be adjusted low. As the microwave heating means, for example, a microwave heater or the like is used. The microwave heating means is generally means for heating with electromagnetic energy having a microwave frequency of 1 to 100 GHz or a frequency slightly lower than that.

  The halogen-containing plastic waste, the amino compound or amino compound precursor, and the alkaline solution are heated using, for example, a reaction vessel or a pressure vessel equipped with the heating means. The reaction vessel and the pressure vessel are not particularly limited as long as they have heating means, and for example, an autoclave device, a pressure resistant microwave heater, or the like can be used. The reaction vessel and pressure vessel are advantageously provided with stirring means, a thermometer, a temperature control device and the like. Since the reaction vessel and the pressure vessel used in this invention are such simple processing equipment, the equipment cost when constructing the processing equipment can be reduced, its maintenance and inspection are easy, and this invention This method can be easily implemented, and its workability is high.

  In the method of the present invention, when a halogen-containing plastic waste is heat-treated with an amino compound or an amino compound precursor and an alkaline solution, the halogen-containing plastic waste is mixed with, for example, a halogen-containing material or a halogen-containing plastic in the halogen-containing plastic waste. Low-molecular organic compounds such as decomposed products of additives and amino compounds or amino compound precursors, and optionally alkali salts such as halogens are extracted. And after heat processing, the mixture of a halogen-containing plastic waste, an amino compound or an amino compound precursor, and an alkaline solution changes into the processing mixture of an extract and solid content. This processing mixture is separated into solid and liquid parts by solid-liquid separation means. The solid-liquid separation means is not particularly limited, and examples thereof include known means such as filtration means and centrifugal separation means.

  The separated solid content contains a plastic from which halogen atoms have been removed or a modified product thereof, and optionally an alkali salt such as halogen. When an alkali salt such as halogen is contained in the solid content, the solid content can be neutralized and / or washed to easily remove the alkali salt such as halogen.

  As described above, the method of the present invention is a method in which a halogen-containing plastic waste is heat-treated at a specific temperature together with a specific amount of an amino compound or amino compound precursor and a specific concentration of an alkaline solution. Even if an amino compound or an amino compound precursor is mixed in the product, a halogen atom can be obtained using a simple treatment facility without requiring the work of strictly separating the amino compound or amino compound precursor from the halogen-containing plastic waste. It is possible to remove halogen atoms from a plastic waste containing benzene in a short time and at a low cost. Moreover, since the method of this invention can be implemented with a simple processing facility, it is possible to realize reduction in equipment cost, ease of maintenance and inspection, ease of implementation of the method of this invention, and high workability.

  Therefore, according to the present invention, halogen atoms can be efficiently removed from halogen atom-containing plastic waste in a short time. The solid content separated by the method of the present invention, from which halogen atoms have been removed, can be recycled as industrial raw materials, or even if it is incinerated. No halogen-containing substances such as halogen gas and hydrogen halide gas are generated by the thermal decomposition of the gas, and thus the incinerator is not damaged and dioxins are not generated.

  Further, according to the method of the present invention, even when polyurethane or the like is used as an amino compound precursor, an amino compound precursor such as polyurethane that may generate harmful gas can be efficiently decomposed in a short time, Halogen atoms can be efficiently removed from halogen atom-containing plastic waste in a short time by the amino compound generated by decomposition. The solid content separated by the method of the present invention, from which both halogen atoms and amino compounds or amino compound precursors have been removed, can be recycled as industrial raw materials, or disposed of by incineration. In this case, halogen-containing substances and harmful gases such as cyan are not generated. Therefore, according to the present invention, an amino compound or an amino compound precursor can be efficiently decomposed in a short time from a mixture of a halogen-containing plastic waste and an amino compound or an amino compound precursor, and a halogen atom can be shortened. The object that it can be efficiently removed in time can be achieved. That is, according to the method of the present invention, part or all of the work of separating the halogen-containing plastic waste and the amino compound or amino compound precursor from the mixture of the halogen-containing plastic waste and the amino compound or amino compound precursor. Can be omitted.

  In the method of the present invention, the halogen-containing plastic waste and / or amino compound or amino compound precursor may be washed in advance before the heat treatment, and the halogen-containing plastic waste and / or amino compound or You may remove the additive etc. which are contained in the amino compound precursor previously.

Example 1
A blood tube made of soft polyvinyl chloride (polyvinyl chloride 59.2% by mass, di (n-octyl) phthalate 29.7% by mass, chlorine atom content 0.01 mol / g) is about 200 μm square. And a 1 g polyvinyl chloride sample was taken. A microwave heating apparatus (trade name) 1.0 g of a collected polyvinyl chloride sample, 3 mL of 98% hydrazine (total amino group content 0.191 mol), and 50 mL of an alkaline solution having a sodium hydroxide concentration of 2.0 mol / L. “Microsys” (manufactured by Milestone General Co., Ltd.) and a pressure vessel with an internal volume of 100 mL equipped with stirring means were heated to 190 ° C. for 30 minutes with stirring.

  A treated mixture of liquid and solid content was obtained after heating. The treated mixture was filtered to recover the liquid component. This liquid content was diluted 1000 times with pure water, and the resulting diluted solution was analyzed with an ion chromatograph (7310-20 model, Nikkiso Co., Ltd.), and the amount of chlorine ions contained in this liquid content was measured. . The measured chlorine ion amount was converted to the content of chlorine atoms contained in 1.0 g of the polyvinyl chloride sample, and the chlorine ion removal rate (%) was calculated. The results are shown in Table 1.

(Examples 2 and 3 and Comparative Examples 1 to 4)
Except for changing the usage amount of 98% hydrazine to the usage amount shown in Table 1, in the same manner as in Example 1, 1.0 g of a polyvinyl chloride sample, 98% hydrazine, and 50 mL of an alkaline solution were heat-treated. The chlorine ion removal rate (%) was calculated. The results are shown in Table 1.

Example 4
The blood tube made of soft polyvinyl chloride was pulverized to a size of about 200 μm square, and 1 g of polyvinyl chloride sample was collected. On the other hand, a polyurethane buffer material as an amino compound precursor was pulverized to a size of about 200 μm square, and 0.05 g of a polyurethane sample was collected.

  A 1.0 g sample of collected polyvinyl chloride, 0.05 g of sampled polyurethane sample, and 50 mL of an alkaline solution having a sodium hydroxide concentration of 2.0 mol / L were placed in a microwave heating apparatus (trade name “Microsys”: miles Stone General Co., Ltd.) and a pressure vessel with an internal capacity of 100 mL equipped with stirring means were heated to 190 ° C. for 30 minutes with stirring.

  A treated mixture of liquid and solid content was obtained after heating. The treated mixture was filtered to recover the liquid component. This liquid content was diluted 1000 times with pure water, and the resulting diluted solution was analyzed with an ion chromatograph (7310-20 model, Nikkiso Co., Ltd.), and the amount of chlorine ions contained in this liquid content was measured. . The measured chlorine ion amount was converted to the content of chlorine atoms contained in 1.0 g of the polyvinyl chloride sample, and the chlorine ion removal rate (%) was calculated. The results are shown in Table 2.

(Examples 5 and 6 and Comparative Examples 5 to 7)
A polyvinyl chloride sample 1.0 g, a polyurethane sample 0.05 g, and an alkaline solution 50 mL were heated in the same manner as in Example 4 except that the sodium hydroxide concentration in the alkaline solution was changed to the concentration shown in Table 2. The chlorine ion removal rate (%) was calculated. The results are shown in Table 2.

(Examples 7 to 10 and Comparative Example 8)
A polyvinyl chloride sample 1.0 g, a polyurethane sample, and a polyurethane sample were obtained in the same manner as in Example 4 except that the usage amount of the polyurethane sample collected from the pulverized polyurethane cushioning material was changed to the usage amount shown in Table 3. A 50 mL alkaline solution having a sodium hydroxide concentration of 2.0 mol / L was heat-treated, and the chloride ion removal rate (%) was calculated. The results are shown in Table 3.

(Example 11)
The blood tube made of soft polyvinyl chloride was pulverized to a size of about 200 μm square, and 1 g of polyvinyl chloride sample was collected. On the other hand, an ether-based polyurethane cushioning material for vehicles (model “TNW”, manufactured by Bridgestone Chemicals Co., Ltd.) as an amino compound precursor is pulverized to a size of about 200 μm square, and a 0.025 g ether-based polyurethane sample is collected. did.

  1.0 g of the collected polyvinyl chloride sample and 0.025 g of the collected polyurethane sample (the total amino group amount in the ether polyurethane buffer material is 0.5 mol or more with respect to 100 parts by mass of the polyvinyl chloride sample). A pressure-resistant container having an internal capacity of 100 mL equipped with 50 mL of an alkaline solution having a sodium hydroxide concentration of 2.0 mol / L and a microwave heating device (trade name “Microsys” manufactured by Milestone General Co., Ltd.) and stirring means And heated to 180 ° C. for 30 minutes with stirring.

  A treated mixture of liquid and solid content was obtained after heating. The treated mixture was filtered to recover the liquid component. This liquid content was diluted 1000 times with pure water, and the resulting diluted solution was analyzed with an ion chromatograph (7310-20 model, Nikkiso Co., Ltd.), and the amount of chlorine ions contained in this liquid content was measured. . The measured chlorine ion amount was converted to the content of chlorine atoms contained in 1.0 g of the polyvinyl chloride sample, and the chlorine ion removal rate (%) was calculated. The results are shown in Table 4.

(Examples 12 to 14)
A polyvinyl chloride sample of 1.0 g, a polyurethane sample, and a polyurethane sample were obtained in the same manner as in Example 11 except that the usage amount of the polyurethane sample collected from the pulverized ether-based polyurethane buffer was changed to the usage amount shown in Table 4. Then, 50 mL of an alkaline solution having a sodium hydroxide concentration of 2.0 mol / L was heat-treated, and the chlorine ion removal rate (%) was calculated. The results are shown in Table 4.

(Example 15)
The blood tube made of soft polyvinyl chloride was pulverized to a size of about 200 μm square, and 1 g of polyvinyl chloride sample was collected. A collected sample of polyvinyl chloride (1.0 g), 30% trimethylamine (3 mL) (total amino group content 0.059 mol), and an alkaline solution (50 mL) having a sodium hydroxide concentration of 2.0 mol / L were mixed with a microwave heating apparatus (trade name). “Microsys” (Milestone General Co., Ltd.) and a pressure vessel with an internal volume of 100 mL equipped with stirring means were heated to 180 ° C. for 30 minutes with stirring.

  A treated mixture of liquid and solid content was obtained after heating. The treated mixture was filtered to recover the liquid component. This liquid content was diluted 1000 times with pure water, and the resulting diluted solution was analyzed with an ion chromatograph (7310-20 model, Nikkiso Co., Ltd.), and the amount of chlorine ions contained in this liquid content was measured. . The measured chlorine ion amount was converted to the content of chlorine atoms contained in 1.0 g of the polyvinyl chloride sample, and the chlorine ion removal rate (%) was calculated. The results are shown in Table 5.

(Example 16 and Comparative Examples 9-12)
A polyvinyl chloride sample 1.0 g, 30% trimethylamine, and 50 mL of an alkaline solution were heat-treated in the same manner as in Example 15 except that the usage amount of 30% trimethylamine was changed to the usage amount shown in Table 5. The chlorine ion removal rate (%) was calculated. The results are shown in Table 5.

(Examples 17 and 18 and Comparative Example 13)
A polyvinyl chloride sample 1.0 g was obtained in the same manner as in Example 15 except that 25% ammonia water was used in place of 30% trimethylamine and the amount of 25% ammonia water used was changed to the amount shown in Table 6. Then, 25% aqueous ammonia and 50 mL of alkaline solution were heat-treated, and the chlorine ion removal rate (%) was calculated. The results are shown in Table 6.

(Examples 19 to 24)
A polyvinyl chloride sample 1.0 g was obtained in the same manner as in Example 15 except that 2-ethanolamine was used instead of 30% trimethylamine and the amount of 2-ethanolamine used was changed to the amount shown in Table 7. And 2-ethanolamine and 50 mL of alkaline solutions were heat-processed, and the chlorine ion removal rate (%) was computed. The results are shown in Table 7.

  As described above, according to the method of the present invention, halogen atoms can be efficiently removed from plastic waste containing halogen atoms in a short time.

Claims (3)

A plastic waste containing halogen atoms, an amino compound in which the total amino group amount per 100 g of the plastic waste is the following molar amount, and a concentration of 2500 to 50000 parts by mass with respect to 100 parts by mass of the plastic waste Is a heat treatment of sodium hydroxide aqueous solution or potassium hydroxide aqueous solution of 0.1 to 3.5 mol / L at 150 to 250 ° C.
When the amino compound is 2-aminoethanol : 0.5 to 50 mol When the amino compound is hydrazine : 10 to 35 mol When the amino compound is ammonia : 55 to 150 mol The amino compound is trimethylamine . If present: 4-30 mol The method for treating plastic waste according to claim 1, wherein the plastic waste is soft polyvinyl chloride having a halogen atom content of 3 mol / g or less . The method for treating plastic waste according to claim 1 or 2, wherein the heat treatment is performed for at least 20 minutes .