JPH0948980A - Method for producing oily substance by decomposition of synthetic polymer - Google Patents

Abstract

(57) [Abstract] [Problem] Development of means for easily decomposing ethylene polymers, which are difficult to thermally decompose in air, even at low temperatures. SOLUTION: Cu (II) acetylacetonate is added to a polyolefin in an amount of 0.005-0.5 g, preferably 0.01-.
0.1 g and sulfur 0.001-10%, preferably 0.0
03-5%, most preferably 0.3-3% (weight basis)
It is added and decomposed in the absence of molecular oxygen at 150 to 600 ° C, preferably 250 to 500 ° C to produce an oil. [Effect] Addition of 0.04 g of the copper complex and 0.4 g of sulfur to 20 g of PE, 10 g of PP and 10 g of PS gives an oily substance [kinematic viscosity
(50 ° C) 1700CSt or less] 48.0 g acquired.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an oil (oil) by decomposing a synthetic polymer. More specifically, it relates to an industrially applicable method for producing useful oil such as fuel oil or raw material oil by decomposing it as a measure for treating and reusing plastic waste that has started to be emphasized in environmental issues.

[0002]

2. Description of the Related Art It is conventionally known that when a synthetic polymer is heated to around 450 ° C., it undergoes thermal decomposition to produce oil, tar-like substances or pitch-like substances. However, according to the conventional technique, it takes a long time to decompose, and it is unacceptable for low productivity, which is not suitable for industrial implementation.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to develop a method suitable for industrial practice by promoting oiling due to decomposition of a synthetic polymer and improving productivity.

[0004]

[Means for Solving the Problems] The present inventors have keenly searched for a method for increasing productivity by adding a catalyst and / or an additive which promotes decomposition and oilification during oiling due to decomposition of a synthetic polymer. As a result, the present invention has been completed. That is,
The present invention is a method completed as a result of repeated studies on various catalysts and / or additives, and the reaction progresses at a low temperature and the time required for the reaction is shortened as compared with the conventional method, resulting in improvement in productivity. It is a method for producing an oily substance by decomposing a realized synthetic polymer.

<Decomposition raw material of the method of the present invention> The synthetic polymer which is a raw material to be treated by the decomposition of the method of the present invention includes both a thermoplastic resin and a thermosetting resin, and is a thermoplastic resin such as polyethylene (PE). ), Polypropylene (PP)
Such as polyolefin (PO), polystyrene (P
S), high-impact polystyrene (HIPS), ABS resin, ethylene-vinyl acetate copolymer resin (EVA), polyvinyl chloride (PVC) and polycarbonate (PC), and a thermosetting resin such as phenol resin, melamine resin, Urea resin, alkyd resin and polyurethane (P
Any of U) and the like may be used alone or as a mixture of two or more kinds.

The synthetic polymer used as the decomposition raw material in the method of the present invention is not limited to synthetic resins, but includes a wide range of soft polymers, copolymers and compositions of two or more of them. Therefore, typical examples thereof are as follows: -ethylene wax-like polymer or grease-like polymer, -propylene wax-like polymer or grease-like polymer such as atactic polypropylene, -synthetic rubber such as ethylene-propylene copolymer Polymerized rubber (E
PM), ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), styrene-butadiene copolymer rubber (S
BR), butadiene-acrylonitrile copolymer rubber (NBR), chloroprene rubber (CR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR) and their crosslinked products (vulcanized products), thermoplasticity Elastomers such as partially crosslinked products of ethylene-propylene-non-conjugated diene copolymer rubber / polyethylene composition, styrene-butadiene copolymer hydrides and synthetic "hydrocarbon resins" such as commonly known as "petroleum resins" are also included.

In particular, the coexistence of a low-melting-point polymer such as atactic polypropylene in the decomposition raw material in a certain amount is preferable for the practice of the method of the present invention. The reason is that when the method of the present invention is carried out in a cracking apparatus, the polymer is first melted and serves to aid the melting or subdividing of the cracked starting polymer which is the change which should occur prior to cracking. That is, it is expected that the melted low melting point polymer will adhere to the surface of the favorite raw material polymer for decomposition to effectively transfer heat energy, and as a result, it will play a role of saving the energy required for melting the favorite polymer. obtain.

Particularly preferred synthetic polymers as raw materials for the method of the present invention are those containing, as main components, polyolefins such as polyethylene and polypropylene, polystyrene and polyptadiene, and copolymers of these component monomers.

<Form and amount of elemental sulfur> The sulfur (S) which is required to coexist in the molten state of the synthetic polymer in the method of the present invention is not limited to pure sulfur, but may be a mineral containing sulfur or the like. As long as the components other than sulfur that do not interfere with the decomposition of the synthetic polymer, the sulfur content may be high or low. Of course, the amount of the mineral used needs to be determined on the basis of the sulfur content. The addition form of the sulfur is not limited to powder, and may be in the form of granules, lumps or the like.

The amount of sulfur added (coexisting amount in the decomposition reaction system) in the method of the present invention is usually 0.001 to 10%, preferably 0.00 based on the weight of the synthetic polymer to be decomposed.
It is set in the range of 03 to 5%, most preferably 0.03 to 3%.

<Organic Sulfur Compound (S) Which Can Generate Free Radicals>
The organosulfur compound (S) used in the method of the present invention is required to be capable of generating a free radical under the reaction conditions. They are roughly classified as follows: (1) Organosulfur compounds containing S—S bonds (excluding “thiurams”) Two groups belonging to an alkyl group, a cycloalkyl group and an aryl group are S- Among the compounds linked to both sides of the S bond, those capable of generating a free radical under the reaction conditions of the present invention. Its structure is represented by each of the following general formulas. In addition,
In these chemical formulas, x is usually a number from 1 to 4.

The above S—S bond-containing compounds can be broadly classified into the following groups: Dialkyl disulfide [general formula: R— (S—S) x—
R ′]: For example, dimethyl disulfide, diethyl disulfide, dibutyl disulfide, alkyl-cycloalkyl disulfide [general formula: R
-(S-S) x-CyR; CyR: cycloalkyl group]: For example, methyl cyclohexyl disulfide, ethyl cyclohexyl disulfide, -alkyl aryl disulfide [general formula: R- (S-
S) x-Ar; Ar: aryl group]: for example, methyl phenyl disulfide, ethyl phenyl disulfide, methyl p
-Oxyphenyl disulfide, methyl o-cresyl disulfide-dicycloalkyl disulfide [general formula: CyR-
(SS) x-CyR ']: For example, dicyclohexyl disulfide, cycloalkyl aryl disulfide [general formula: C
yR- (S-S) x-Ar]: For example, cyclohexyl phenyl disulfide, cyclohexyl p-tolyl disulfide, diaryl disulfide [general formula: Ar- (S-S) x-
Ar ']: For example, diphenyl disulfide, ditolyl disulfide. (2) Thiurams Commonly referred to as "thiurams" are bis (N, N-dialkylthiocarbonyl) polysulfides ("polysulfides" are also referred to as "polysulfides"), one or more of which are represented by the following general formula. Is. Those belonging to this class also belong to the “organic sulfur compound containing an S—S bond” in the preceding section, which will be particularly described in this section. This is due to the fact that it is a compound that is commonly used as a vulcanizing agent (crosslinking agent) or a vulcanization aid (crosslinking aid).

General formula: [RR'N-C (= S)-]-(S) x
-[-C (= S) -NRR '] (x: the number of 1 to 4) [wherein R and R'may be different from each other, and each is a methyl group, an ethyl group, a propyl group, a cyclohexyl group and It is one or more kinds of groups selected from a pentamethylene group, and R and R ′ may be bonded to each other to form a ring. x is a number from 1 to 4. ] Examples of the above thiurams include the following: bis (N, N-dimethylthiocarbonyl) disulfide,
Bis (N, N-diethylthiocarbonyl) disulfide, bis (N, N-dibutylthiocarbonyl) disulfide, bis (N, N-dimethylthiocarbonyl) trisulfide, bis (N, N-diethylthiocarbonyl) tetrasulfide , Bis (piperidinothiocarbonyl) disulfide, bis (morpholinothiocarbonyl) disulfide, etc.

As a chemical name, "morpholine disulfide" is regarded as being used as a common name in the industry although it is lacking in specification because one of the bonding groups is lacking.
(Morpholine disulfide) is also described in "Practical Handbook of Additives for Supplemented Plastics and Rubbers, p.920" (published by Kagaku Kogyo Co., Ltd.). (3) Sulfenamides: The sulfenamides used in the method of the present invention [R ″ -S-NRR ′; R ″: 2-benzothiazyl residue] are the two R and R ′ of the two. At least one is a group having a hydrocarbon group as a basic structure, and examples of the substituents in the above chemical formulas include the following. In the case of R: H, R ': cyclohexyl group or tert-butyl group, and in other cases R and R': ethyl group, i-propyl group, cyclohexyl group or oxyethyl group. (4) Dithioates The dithioates used in the method of the present invention include not only organic acid (carboxylic acid) salts but also inorganic acids. However, the most frequently used dithio acids in the method of the present invention are organic dithio acids. In this section, the dithiocarbamate and the xanthate will be described below. (4.1) Dithiocarbamate is exemplified in the following general formula.

General formula [RR'-NC (= S) -S-] x-Y [wherein R and R'are selected from a methyl group, an ethyl group, an n-butyl group and an ethylphenyl group. When the groups are one or more and may be different from each other and R and R ′ may be bonded to each other to form a ring, for example, a pentamethylene group is used. Y is Zn, Cd, Cu, Pb, Fe,
It is a divalent metal atom selected from Bi, Se, Te, Na or K, or a nitrogen-containing heterocycle selected from a piperidine group or a pipecoline group. x is a valence of Y or a number corresponding to the valence of the nitrogen-containing heterocycle, and is usually 1 to 4. The compound represented by the above general formula is, for example, sodium dimethyldithiocarbamate, potassium diethyldithiocarbamate, zinc bis (dimethyldithiocarbamate), copper bis (dimethyldithiocarbamate), piperidine dimethyldithiocarbamate, pipecoline diethyldithiocarbamate, or the like. is there. (4.2) Xanthogenates (Xanthates) As the xanthate used in the method of the present invention, an alkylxanthate metal salt represented by the following general formula is preferable.

General formula (ROCSS) x-Z [wherein R represents an alkyl group which may have a branch, and Z represents a metal atom. x is a number corresponding to the valence of Z, and is usually 1 to
4. Examples of the xanthate represented by the above general formula include zinc diisopropylxanthogenate, zinc dibutylxanthogenate and the like. (5) Thiourea (thiourea) thiourea used in the method of the present invention preferably has at least one amino group of two amino groups having at least one hydrogen atom. The most useful thioureas in the method of the present invention are exemplified by the following general formula.

The general formula R-NH-C (= S) -NR'R "where R, R'and R" are all methyl groups or R "is H And R'is an ethyl group, an n-butyl group, a phenyl group or an ethylene group (R and R'bond together to form a ring).

The above-mentioned thiourea represented by the general formula are, for example, N, N ', N'-trimethylthiourea, N, N'-diethylthiourea, N, N'-di-n-butylthiourea, N , N'-diphenylthiourea or ethylenethiourea. (6) Thiazoles The thiazoles used in the method of the present invention are ordinary thiazoles, which are heterocyclic compounds in which a sulfur atom and a nitrogen atom together with a carbon atom form a five-membered ring. Among the various thiazoles in which the hydrogen atom bonded to 2-C is replaced with a sulfur atom, benzothiazoles are useful.

Suitable thiazoles include, for example, 2-mercaptobenzothiazole, salts of 2-mercaptobenzothiazole, dibenzothiazyl disulfide and the like.

In the method of the present invention, the amount of the organic sulfur compound added (the amount present in the decomposition reaction system) is usually 0.001 to 10%, preferably 0.003 to 5%, based on the weight of the synthetic polymer to be decomposed. Most preferably, it is 0.03 to 3%.

<Transition metal simple substance and / or its ion> In the method of the present invention, the metal and / or its ion preferably coexisting with sulfur and / or its compound in the reaction system (may be collectively referred to as "metals"). Is the Periodic Table 1
The metals of the 4A, 5A, 6A, 7A and 8 groups including the B and 2B groups, and among these metals, the preferred ones are commonly referred to as "transition metals".

Here, the "transition metal" in the method of the present invention.
Is titanium (Ti) which is the 22nd element of the periodic table called the 1st period to zinc which is the 30th element, and zirconium (Zr) which is the 40th element which is called the 2nd period Four
It is mainly composed of cadmium (Cd) which is the 8th element and hafnium (Hf) which is the 72nd element called the 3rd period to mercury (Hg) which is the 80th element.

Among the above-mentioned transition metals [transition metal simple substance and / or its ion (M)], preferable from the viewpoints of both performance and practicality are as follows: titanium, vanazine, chromium, manganese, iron. , Cobalt, nickel, copper, zinc,
molybdenum.

When the above transition metal is mainly used in an ionic state, it means that it is in the form of a compound. As the form of the compound, the form of a complex, also known as “complex salt”, is preferably selected. A wide variety of organic compounds exist on the side of complex-forming ligands, and most of them are used for colorimetric analysis of metals. Most of these complex-forming organic compounds can be used in the present invention, and preferred examples thereof include acetylacetone, ethylenediaminetetraacetic acid (EDTA), 8-oxyquinoline (commonly known as "oxine"), and dimethylglyoxime. Can be mentioned.

<Amount of Metals Added> In the method of the present invention, the amount of one or more (M) selected from metals of Group 1A and 2B and 4A to 7A and 8 of the Periodic Table and ions thereof is a raw material for decomposition. 0.0010 to 10 weight of plastic
%, Preferably in the range of 0.01 to 1%, and represented by the ratio (M / S) to the weight of one or more (S) selected from organic sulfur compounds capable of producing coexisting sulfur and free radicals (M / S) of 1 / 1-1 / 1000, preferably 1 / 2-1 / 10
It is important to be within the range of 0. Here, even when the metal or its ion (M) is used in the form of a complex, the addition amount is based on the metal.

<Operating conditions of the method of the present invention> When decomposing a polyolefin which is often used as a synthetic polymer, the decomposition temperature of the polyolefin is 150 to 600 ° C., preferably 250 to 500 ° C., and the reaction time is from 0.1 min. Set to 5h. The atmosphere of the reaction system may be any atmosphere as long as it does not interfere with this reaction, and for example, nitrogen can be used.

<Decomposition method adopted in the method of the present invention> The reactor may be of any type such as a tank type, a screw type and a pipe type. The reactor is preferably a closed type, but if the reaction temperature is kept at 445 ° C. or lower, which is the boiling point of sulfur, a non-closed type that decomposes while distilling off the oil produced can also be used. Further, even in the existing apparatus, the effect of lowering the temperature of the decomposition reaction or shortening the decomposition reaction time can be obtained by adding only the sulfur addition device and adding sulfur.

A specific example of the decomposition reaction apparatus is a tube-type decomposition furnace equipped with a conveying screw in the tube, and the synthetic polymer to be oiled is heated to 150 to 600 ° C., preferably 250 to 50.
It is equipped with a mechanism for heating to 0 ° C. Since this type of decomposition reactor has a continuous decomposition ability, it is suitable for a processing facility in which a large amount of waste synthetic polymer is constantly (continuously) accumulated.

<Time of Adding Sulfur or Organic Sulfur Compound> The time of adding the sulfur and / or the organic sulfur compound capable of generating a free radical is usually after melting the synthetic polymer, but may be before melting. In the case of addition before melting, the sulfur and / or organic sulfur compound is added to the synthetic polymer at room temperature and then heated to melt the synthetic polymer.

[0030]

According to the method of the present invention, the following various effects can be achieved together: (1) As a result of being able to accelerate the decomposition reaction when the synthetic polymer is decomposed to produce an oil, the reaction time And / or the reaction temperature can be lowered to, for example, 410 ° C., and finally the productivity can be improved; (2) Applicable to a wide range of decomposition raw material polymers, polyvinyl chloride Even if a chloride polymer such as polyvinylidene chloride or chlorinated polyethylene is mixed, the decomposition reaction is not hindered. (3) The present invention can be applied to a conventional decomposition device. That is, if an apparatus for adding an organic sulfur compound capable of producing sulfur and / or free radicals and an apparatus for adding a transition metal complex are additionally provided in the apparatus, an oily substance production facility which can immediately carry out the method of the present invention is formed.

[0031]

EXAMPLES The method of the present invention will be specifically described below based on examples. However, the present invention is not limited thereto.

[0032]

Example 1 Polypropylene 10 g, polyethylene 20
g, polystyrene 10 g, powdered sulfur 0.4 g and Cu (II) acetylacetonate 0.04 g were charged into an autoclave having an internal volume of 100 ml, the inside of the apparatus was replaced with nitrogen, and then heated to 410 ° C. for 10 minutes while stirring. The product obtained is an oil, its weight is 48.0 g and its kinematic viscosity is 50.
It was 1700 CSt or less at ℃.

[0033]

Example 2 Polypropylene 10 g, polyethylene 20
g, polystyrene 10 g, powdered sulfur 0.4 g and Fe (III) acetylacetonate 0.04 g were charged in an autoclave having an internal volume of 100 ml, the inside of the apparatus was replaced with nitrogen, and then heated at 420 ° C. for 10 minutes while stirring. The product obtained is an oil, has a weight of 47.8 g and a kinematic viscosity of 50.
It was 1700 CSt or less at ℃.

[0034]

Example 3 50 g of polypropylene and 0.5 g of powdered sulfur were charged into an autoclave having an internal volume of 100 ml, the inside of the apparatus was replaced with nitrogen, and the mixture was stirred at 420 ° C. for 10 minutes.
Heated. The product obtained is an oil and has a weight of 4
7.5 g, its kinematic viscosity was 120 cSt or less at 50 ° C.

[0035]

Comparative Example 1 50 g of polypropylene was placed in a 100 ml autoclave, the inside was replaced with nitrogen, and the mixture was heated to 440 ° C. for 10 minutes while stirring. The product was waxy and had a kinematic viscosity of less than 1900 cSt at 50 ° C.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B01J 23/38 B01J 23/38 X 23/70 23/70 X B29B 17/00 9350-4F B29B 17 / 00 C08F 210/00 C08F 210/00 C08J 11/10 C08J 11/10 11/18 11/18 11/28 11/28 C08K 3/08 C08K 3/08 3/10 3/10 (72) Inventor Hiro Noriyuki Watanabe 6-1-2, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd.

Claims (14)

[Claims] 1. When the synthetic polymer is decomposed at a temperature of 150 to 600 ° C. and turned into an oil, one or more kinds selected from sulfur and an organic sulfur compound capable of generating a free radical are contained in an amount of 0 based on the weight of the synthetic polymer. A method for producing an oily substance, characterized in that it is allowed to coexist in the range of 0.001 to 10%. 2. One or more kinds (M) selected from metals of groups 1A and 2B of the periodic table and groups 4A to 7A and 8 and ions thereof.
Is 0.001 to 10% with respect to the weight of the synthetic polymer, and the ratio (M / M) to the weight of one or more (S) selected from organic sulfur compounds capable of generating coexisting sulfur and free radicals.
The method for producing an oily substance according to claim 1, further comprising coexisting in the decomposition reaction system in the range of 1/1 to 1/1000, represented by S). 3. An organic compound containing an S—S bond as an organic sulfur compound capable of generating a free radical is allowed to coexist in the range of 0.001 to 10% with respect to the weight of the synthetic polymer. 3. The method for producing an oily product according to 1 or 2. 4. The method according to any one of claims 1 to 3, wherein one or more kinds selected from sulfur and organic sulfur compounds capable of generating free radicals are coexistent in the range of 0.003 to 5% based on the weight of the synthetic polymer. A method for producing the described oily substance. 5. The method for producing an oily product according to claim 1, wherein the sulfur compound capable of generating a free radical is a thiuram. 6. The method for producing an oily product according to claim 1, wherein the sulfur compound capable of generating a free radical is a sulfenamide. 7. The method for producing an oily product according to claim 1, wherein the sulfur compound capable of generating a free radical is a dithioate salt. 8. The method for producing an oily product according to claim 7, wherein the sulfur compound capable of generating a free radical is a xanthate (xanthate). 9. The method for producing an oily product according to claim 1, wherein the sulfur compound capable of generating a free radical is a thiourea. 10. The method for producing an oily product according to claim 1, wherein the sulfur compound capable of generating a free radical is a thiazole. 11. The method for producing an oily product according to claim 1, wherein the synthetic polymer is a polymer mixture containing at least polyethylene, polypropylene and polystyrene in a decomposition reaction system. 12. A method for producing an oily product according to any one of claims 2 to 11, wherein the Group 1B and 2B of the Periodic Table and the metals of Groups 4A to 7A and 8 are one or more of the following: titanium, vanadium and chromium. , Manganese, iron, cobalt, nickel, copper, zinc,
Zircon, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury. 13. The method for producing an oily product according to any one of claims 2 to 12, wherein the Group 1B and 2B of the periodic table and the metals of groups 4A to 7A and 8 are one or more of the following: titanium, vanazine,
Chromium, manganese, iron, cobalt, nickel, copper, zinc and molybdenum. 14. The method for producing an oily product according to any one of claims 2 to 13, wherein the organic compound exhibiting a complex-forming property with respect to metals is one or more of the following:
8-oxyquinoline, ethylenediaminetetraacetic acid, dimethylglyoxime.