Process for producing an oilified composition, process for chemical recycling, process for producing a regenerated chemical raw material, process for producing a polymer, process for producing a molded body

Abstract

A method for manufacturing an oleochemical composition having a high hydrocarbon content and shortening thermal decomposition time is provided. The method comprises: a first step of heating a resin composition containing an ethylene-vinyl alcohol copolymer (A) at a temperature of 240°C to 450°C and maintaining it at a temperature range of ±30°C to remove the obtained gas; and a second step of heating at a temperature higher than the heating temperature of the first step and exceeding 400°C.

Description

Technical Field

[0001] This invention relates to methods for manufacturing oil-based compositions, chemical recycling methods, methods for manufacturing recycled chemical raw materials, methods for manufacturing polymers, and methods for manufacturing molded articles. More specifically, it relates to methods for manufacturing oil-based compositions that can increase the proportion of hydrocarbons contained in the oil-based compositions and shorten the thermal decomposition time, methods for chemical recycling, methods for manufacturing recycled chemical raw materials, methods for manufacturing polymers, and methods for manufacturing molded articles. Background Technology

[0002] Ethylene-vinyl alcohol copolymer (hereinafter, sometimes referred to as "EVOH resin") has excellent transparency, gas barrier properties such as oxygen, aroma retention, solvent resistance, oil resistance, and mechanical strength. It is molded into films, sheets, bottles, etc., and is widely used as a variety of packaging materials such as food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, and pesticide packaging materials.

[0003] In recent years, from the perspective of efficient resource utilization, there has been a demand for the recycling of used waste plastics containing EVOH resin. Recycling of such waste plastics includes thermal recycling, chemical recycling, and material recycling, with thermal recycling accounting for the majority. However, thermal recycling involves recovering and utilizing the heat energy generated during incineration; therefore, there is a need for recycling methods that can further reduce the environmental impact.

[0004] Unlike thermal recycling, which involves recycling waste plastics into recycled products, chemical recycling is a method of returning high-molecular-weight plastics to a low-molecular-weight state for reuse. It is expected to further reduce the environmental impact of recycling. Furthermore, most polyolefins commonly used in plastics can be recycled into naphtha feedstock (oil-based compositions) through chemical recycling.

[0005] For example, Patent Document 1 discloses a method for the chemical recycling of plastics, which thermally decomposes plastic waste containing olefin-based plastics and a specific amount of EVOH resin, causing the generated thermally decomposed components to undergo catalytic cracking, and recovering decomposed oil or decomposed gas.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 5-345894 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The inventors have discovered that when preparing an oily composition from plastic waste containing EVOH resin, as disclosed in Patent Document 1, through thermal decomposition, not only are the desired hydrocarbons mixed in, but also oxygen-containing compounds formed by the decomposition of high-molecular-weight plastics. These oxygen-containing compounds can sometimes cause corrosion and decomposition inhibition of equipment during naphtha cracking (decomposition) of the naphtha containing the oily composition. Therefore, a method for manufacturing an oily composition that increases the proportion of hydrocarbons and shortens the thermal decomposition time is desired.

[0011] Therefore, the present invention provides a method for manufacturing an oil-based composition with a high hydrocarbon content and a shortened thermal decomposition time.

[0012] Solution for solving the problem

[0013] However, in view of this situation, the inventors have discovered that the problem can be solved by thermally decomposing the resin composition containing EVOH resin under two-stage conditions.

[0014] That is, the present invention has the following solution.

[0015] [1] A method for manufacturing an oily composition, comprising: a first step of heating a resin composition containing EVOH resin (A) at a temperature of 240°C to 450°C and maintaining it at a temperature range of ±30°C from the heating temperature to remove the obtained gas; and a second step of heating at a temperature higher than the heating temperature of the first step and exceeding 400°C.

[0016] [2] The method for manufacturing the oil-based composition according to [1], wherein the heating temperature in the first step is 300°C to 430°C.

[0017] [3] The method for manufacturing the oil-based composition according to [1] or [2], wherein the heating temperature in the second step is above 400°C and below 600°C.

[0018] [4] The method for manufacturing the oil-based composition according to any one of [1] to [3], wherein the heating time of the first step is 5 minutes or more and less than 60 minutes.

[0019] [5] The method for manufacturing the oil-based composition according to any one of [1] to [4], wherein the heating time of the second step is 10 minutes or more and 45 minutes or less.

[0020] [6] A method for manufacturing an oil-based composition according to any one of [1] to [5], wherein the proportion of hydrocarbons contained in the oil-based composition is 50% by mass or more relative to the total oil-based composition.

[0021] [7] A method for manufacturing an oil-based composition according to any one of [1] to [6], wherein hydrocarbons are recovered in the second step.

[0022] [8] A method for manufacturing an oil-based composition according to any one of [1] to [7], wherein the method for manufacturing the oil-based composition includes a distillation step after the second step.

[0023] [9] The method for manufacturing the oil-based composition according to [8] wherein, in the distillation process, distillation is carried out at a pressure of 100 mmHg to 760 mmHg and a temperature of 70°C to 250°C.

[0024]

[10] A chemical recycling method that uses the method for manufacturing an oily composition according to any one of [1] to [9].

[0025]

[11] A method for manufacturing a regenerated chemical raw material, wherein the method comprises naphtha containing an oleochemical composition obtained by the method of manufacturing an oleochemical composition according to any one of [1] to [9], and the regenerated chemical raw material is obtained by naphtha cracking treatment.

[0026]

[12] The method for manufacturing the recycled chemical raw material according to

[11] , wherein the recycled chemical raw material is ethylene and / or propylene.

[0027]

[13] A method for manufacturing a polymer comprising polymerizing a monomer composition of a recycled chemical raw material obtained by a method for manufacturing recycled chemical raw materials according to

[11] or

[12] to obtain the polymer.

[0028]

[14] A method for manufacturing a molded article, wherein the molded article is obtained by molding a resin composition comprising a polymer obtained by a method for manufacturing a polymer according to

[13] .

[0029] Invention Effects

[0030] The manufacturing method of the present invention can shorten the thermal decomposition time. In addition, the oil-based composition obtained by the manufacturing method of the present invention can increase the hydrocarbon content by reducing the content of impurities such as oxygen-containing compounds. Detailed Implementation

[0031] The present invention will now be described based on examples of methods for carrying out the invention. However, the present invention is not limited to the embodiments described below.

[0032] It should be noted that in this specification, "X and / or Y (X and Y are arbitrary configurations)" refers to at least one of X and Y, and specifically refers to the three options: only X, only Y, or X and Y.

[0033] In this specification, when expressed as "X~Y" (where X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "more than X and less than Y", as well as the meaning of "preferably more than X" or "preferably less than Y".

[0034] In this specification, the expressions “X or more” (where X is any number) or “Y or less” (where Y is any number) also include the meaning of “preferably more than X” or “preferably less than Y”.

[0035] Regarding the numerical ranges described in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limits of other numerical ranges. Furthermore, within the numerical ranges described in this specification, the upper or lower limit can also be replaced with the values ​​shown in the embodiments.

[0036] In this specification, "main component" refers to the component that has a significant impact on the properties of the object. The content of this component is usually 50% by mass or more in the object, preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and may also be 100% by mass.

[0037] A method for manufacturing an oil-based composition according to one embodiment of the present invention (hereinafter, sometimes referred to as "this manufacturing method") includes: a first step of heating a resin composition containing EVOH resin (A) at a temperature of 240°C to 450°C and maintaining it at a temperature range of ±30°C from the heating temperature to remove the obtained gas; and a second step of heating at a temperature higher than the heating temperature of the first step and exceeding 400°C.

[0038] The resin composition will be described below before the manufacturing method is explained.

[0039] <Resin Composition>

[0040] There are no particular limitations on the resin composition as long as it contains EVOH resin (A).

[0041] [EVOH resin (A)]

[0042] The EVOH resin (A) used in this manufacturing method is generally a non-water-soluble thermoplastic resin obtained by saponifying an ethylene-ethylene copolymer, which is a copolymer of ethylene and ethylene ester monomers.

[0043] Vinyl acetate is representatively used as the vinyl ester monomer because of its market availability and efficient impurity removal during manufacturing. Other vinyl ester monomers besides vinyl acetate include, for example, aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl neopentanoate, vinyl decanoate, vinyl laurate, vinyl stearate, vinyl tert-carbonate, and aromatic vinyl esters such as vinyl benzoate. Aliphatic vinyl esters with 3 to 20 carbon atoms are typically used, preferably with 4 to 10 carbon atoms, and particularly preferably with 4 to 7 carbon atoms. They are usually used alone, but multiple types can also be used simultaneously as needed.

[0044] As a polymerization method for copolymerizing ethylene with ethylene ester monomers, any known polymerization method can be used, such as solution polymerization, suspension polymerization, emulsion polymerization, etc., typically using solution polymerization with methanol as a solvent. Furthermore, the saponification of the resulting ethylene-ethylene ester copolymer can also be carried out using known methods.

[0045] The EVOH resin produced in this way is mainly composed of ethylene-derived structural units and vinyl alcohol structural units, with a small amount of unsaponified and residual vinyl ester structural units.

[0046] The ethylene structural units in the EVOH resin (A) typically comprise 20 mol% to 60 mol%, preferably 25 mol% to 50 mol%, and particularly preferably 25 mol% to 35 mol%. The proportion of the ethylene structural units can be controlled by the pressure of the ethylene during copolymerization of the ethylene ester monomer and ethylene.

[0047] It should be noted that the content ratio of this ethylene structural unit can be determined by... 1 It is determined by H-NMR measurement. For example, using... 1 The method involves H-NMR determination using d-DMSO (deuterated dimethyl sulfoxide) as the solvent and setting the measurement temperature to 50℃.

[0048] The degree of saponification in the EVOH resin (A) is typically 90 mol% to 100 mol%, preferably 95 mol% to 100 mol%, and particularly preferably 99 mol% to 100 mol%. The degree of saponification can be controlled by the amount of saponification catalyst (typically an alkaline catalyst such as sodium hydroxide) used during the saponification of the ethylene-ethylene ester copolymer, the temperature, and the time.

[0049] The saponification degree of this EVOH resin can be determined by... 1 It is determined by H-NMR measurement. For example, using... 1 The method involves H-NMR determination using d-DMSO as the solvent and setting the measurement temperature to 50℃.

[0050] The melt flow rate (MFR) of the EVOH resin (A) (210°C, 2160g load) is typically 0.5g / 10min to 100g / 10min, preferably 1g / 10min to 50g / 10min, and particularly preferably 3g / 10min to 35g / 10min.

[0051] The MFR is an indicator of the degree of polymerization of EVOH resin (A), which can be adjusted by adjusting the amount of polymerization initiator and solvent during the copolymerization of ethylene and ethylene ester monomers.

[0052] Furthermore, the EVOH resin (A) may also contain structural units derived from the comonomers shown below (e.g., less than 10 mol% of EVOH resin (A)) to a extent that does not impede the effects of the present invention.

[0053] Examples of comonomers include, for instance: olefins such as propylene, 1-butene, and isobutene; hydroxyl-containing α-olefins such as 3-buten-1-ol, 3-buten-1,2-diol, 4-penten-1-ol, and 5-hexen-1,2-diol, and their esterifications, acylates, and other derivatives; hydroxyalkyl vinylides such as 2-methylenepropane-1,3-diol and 3-methylenepentane-1,5-diol; and 1,3-diacetoxy-2-methylenepropane, 1,3-dipropionyloxy-2-... Hydroxyalkyl vinylidene diacetate esters such as methylene propane and 1,3-dibutyryloxy-2-methylene propane; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, phthalic acid (anhydride), maleic acid (anhydride), itaconic acid (anhydride), or their salts, or mono- or dialkyl esters with alkyl groups having 1 to 18 carbon atoms; acrylamide, N-alkylacrylamide, N,N-dimethylacrylamide, 2-acrylamide propanesulfonic acid or their salts, and acrylamide propyl dimethylamine with alkyl groups having 1 to 18 carbon atoms. Acrylamides such as their acid salts or quaternary ammonium salts; methacrylamides, N-alkylmethacrylamides with alkyl groups having 1 to 18 carbon atoms, N,N-dimethylmethacrylamide, 2-methacrylamide propanesulfonic acid or its salts, methacrylamide propyl dimethylamine or its acid salts or quaternary ammonium salts, etc.; N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, etc.; cyanide vinyl compounds such as acrylonitrile and methacrylonitrile; alkyl carbon Vinyl ethers with 1 to 18 atoms, such as alkyl vinyl ethers, hydroxyalkyl vinyl ethers, and alkoxyalkyl vinyl ethers; halogenated vinyl compounds such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, and vinyl bromide; vinyl silanes such as trimethoxyvinylsilane; halogenated allyl compounds such as allyl acetate and allyl chloride; allyl alcohols such as allyl alcohol and dimethoxyallyl alcohol; and comonomers such as trimethyl-(3-acrylamido-3-dimethylpropyl)-ammonium chloride and acrylamide-2-methylpropanesulfonic acid. These can be used alone or in combination of two or more.

[0054] In addition, as the EVOH resin (A), EVOH resins that have undergone "post-modification" such as esterification, urethane esterification, acetalization, cyanoethylation, and oxidative alkylene modification can also be used.

[0055] Furthermore, the EVOH resin (A) can also be a mixture of EVOH resins with different proportions of ethylene structural units, degrees of saponification, degrees of polymerization, and copolymer components.

[0056] The content of the EVOH resin (A) is not particularly limited, but is generally 0.1% to 90% by mass relative to the total resin composition, preferably 1% to 50% by mass, and particularly preferably 5% to 20% by mass.

[0057] The resin composition may contain thermoplastic resins other than EVOH resin (A) and compounding agents. That is, the resin composition may be a thermoplastic resin composition containing EVOH resin (A).

[0058] [Thermoplastic resins other than EVOH resin]

[0059] Other than the EVOH resin (A) mentioned above, known thermoplastic resins include, for example, linear low-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene, high-density polyethylene, polyethylene-propylene (block and random) copolymers, ethylene-α-olefin (α-olefin with 4 to 20 carbon atoms) copolymers and other polyethylene-based resins, polypropylene, propylene-α-olefin (α-olefin with 4 to 20 carbon atoms) copolymers and other polypropylene-based resins, polybutene, polypentene, polycyclic olefin resins (polymers in which at least one of the main chain and side chain has a cyclic olefin structure) and other (unmodified) polyolefin resins. Resins, including broadly defined polyolefin resins such as unsaturated carboxylic acid-modified polyolefin resins obtained by grafting these polyolefin resins with unsaturated carboxylic acids or their esters, ionomers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-acrylate copolymers, polyester resins, polyamide resins (including copolyamides), polyvinyl chloride, polyvinylidene chloride, acrylic resins, polystyrene resins, vinyl ester resins, polyester elastomers, polyurethane elastomers, polystyrene elastomers, halogenated polyolefins such as chlorinated polyethylene and chlorinated polypropylene, aromatic or aliphatic polyketides, etc. These can be used alone or in combination of two or more. Among these, polyolefin resins and polyamide resins are preferred, and polyethylene resins and polypropylene resins are more preferred.

[0060] It should be noted that linear low-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene, and high-density polyethylene are commonly used terms to describe different types of polyethylene.

[0061] When the resin composition contains a thermoplastic resin other than EVOH resin (A), the proportion thereof relative to the total resin composition is typically 1% to 90% by mass, preferably 10% to 80% by mass, and particularly preferably 20% to 70% by mass.

[0062] [Combining agents]

[0063] Examples of compounding agents commonly used in thermoplastic resins include inorganic complex salts, plasticizers, oxygen absorbers, heat stabilizers, light stabilizers, ultraviolet absorbers, colorants, antistatic agents, surfactants (excluding surfactants used as lubricants), antibacterial agents, antiblocking agents, fillers, compatibilizers, etc. These can be used alone or in combination of two or more.

[0064] Examples of such inorganic complex salts include hydrotalcite.

[0065] Examples of plasticizers include, for example, aliphatic polyols such as ethylene glycol, glycerin, and hexanediol.

[0066] Examples of oxygen absorbers include: inorganic oxygen absorbers such as aluminum powder and potassium sulfite; ascorbic acid, fatty acid esters of ascorbic acid, metal salts of ascorbic acid, gallic acid, polyphenols such as hydroxyl-containing phenolic resins, terpene compounds, blends of resins containing tertiary hydrogen and transition metals (e.g., a combination of polypropylene and cobalt), blends of resins containing carbon-carbon unsaturated bonds and transition metals (e.g., a combination of polybutadiene and cobalt), photo-oxidatively disintegrating resins (e.g., polyketide), anthraquinone polymers (e.g., polyethylene anthraquinone), and polymeric oxygen absorbers formed by adding photoinitiators (benzophenone, etc.), antioxidants other than those mentioned, and deodorizers (activated carbon, etc.) to these complexes.

[0067] When the resin composition contains a compounding agent, the proportion thereof is generally 20% by mass or less relative to the total resin composition, preferably 15% by mass or less, and particularly preferably 10% by mass or less.

[0068] [Shape of the resin composition]

[0069] The shape of the resin composition is not particularly limited, and examples include granules, films, sheets, molded bodies, pulverized materials, broken materials, and irregular products.

[0070] The sources of the granules, films, sheets, molded bodies, etc., are not particularly limited. For example, they can be obtained from post-consumer recycling (PCR) or post-industrial recycling (PIR).

[0071] When the resin composition is in the form of a molded body, the molded body may be a single layer consisting only of a layer containing EVOH resin (A) (hereinafter referred to as "EVOH resin layer"), or it may be a multilayer laminate consisting of an EVOH resin layer and a base resin layer whose main component is a thermoplastic resin other than EVOH resin (hereinafter, the resin used for the base material is referred to as "base resin"). Examples of the base resin include thermoplastic resins other than the aforementioned EVOH resin.

[0072] Furthermore, the multilayer laminate may contain multiple EVOH resin layers and substrate resin layers, and an adhesive resin layer containing adhesive resin may be sandwiched between the EVOH resin layers and the substrate resin layers as needed.

[0073] The adhesive resin is selected appropriately according to the base resin. Representative examples include modified polyolefin polymers containing carboxyl groups obtained by chemically bonding unsaturated carboxylic acids or their anhydrides with polyolefin resins through addition reactions, grafting reactions, etc.

[0074] Examples of carboxyl-containing modified polyolefin polymers include, for example, maleic anhydride-grafted modified polyethylene, maleic anhydride-grafted modified polypropylene, maleic anhydride-grafted modified ethylene-propylene (block and random) copolymers, maleic anhydride-grafted modified ethylene-ethyl acrylate copolymers, maleic anhydride-grafted modified ethylene-vinyl acetate copolymers, maleic anhydride-modified polycyclic olefin resins, and maleic anhydride-grafted modified polyolefin resins. These can be used alone or in combination of two or more.

[0075] Furthermore, when the shape of the resin composition is a molded body, the molded body can be a molded body composed of a single layer film or a molded body composed of multiple layers film.

[0076] The resin composition can be cut or pulverized before being supplied to the first process.

[0077] There are no particular limitations on the methods used for cutting and shredding.

[0078] As a method of cutting, for example, a cutting method using a slitting machine, a shredder or other cutting machine can be listed.

[0079] Furthermore, examples of the aforementioned pulverizing process include: pulverizing using a pulverizer; pulverizing using a primary pulverizer followed by a secondary pulverizer for further fine pulverization; and pulverizing in stages using multiple pulverizers. These cutting and pulverizing processes can be used individually or in combination of two or more.

[0080] In this manufacturing method, the resin composition is thermally decomposed by a method described later to obtain thermally decomposed products. If the resin composition contains a chlorine-containing thermoplastic resin such as polyvinyl chloride, it is preferable to perform a dechlorination treatment before thermal decomposition.

[0081] As a method for the dechlorination treatment, well-known methods such as twin-screw extruder dechlorination can be cited.

[0082] The twin-screw extruder dechlorination method refers to a method in which a resin composition is melted at 200°C to 230°C using a twin-screw extruder, and then extruded at approximately 350°C, thereby separating the hydrogen chloride. The dechlorinated resin composition is then supplied to this manufacturing method.

[0083] <This manufacturing method>

[0084] This manufacturing method includes: a first step of heating a resin composition containing EVOH resin (A) at a temperature of 240°C to 450°C and maintaining the temperature within a temperature range of ±30°C to remove the resulting gas; and a second step of heating at a temperature higher than the heating temperature of the first step and exceeding 400°C. That is, in this manufacturing method, a first-stage thermal decomposition (heating at 240°C to 450°C and maintaining the temperature within a temperature range of ±30°C) is followed by a second-stage thermal decomposition at a temperature higher than the first stage and exceeding 400°C.

[0085] Typically, the oleochemical composition obtained by thermally decomposing a resin composition containing EVOH resin (A) contains, in addition to hydrocarbons, oxygen-containing compounds generated by the reduction of high molecular weight components contained in EVOH resin (A). When a large amount of these oxygen-containing compounds is present, there is a tendency to cause corrosion and decomposition inhibition of equipment during naphtha cracking treatment of naphtha containing the obtained oleochemical composition.

[0086] Therefore, in this invention, a large amount of oxygen-containing compounds are generated in the first stage of thermal decomposition (first process) and separated, thereby increasing the proportion of hydrocarbons in the oiled composition obtained after the second process, that is, reducing the proportion of impurities such as oxygen-containing compounds in the oiled composition.

[0087] The term "hydrocarbon" refers to compounds that do not contain heteroatoms and consist only of carbon and hydrogen, such as ethylene and propylene.

[0088] The manufacturing method is described in detail below.

[0089] The apparatus used in this manufacturing method is not particularly limited, and examples include apparatus commonly used for the oiling of polyolefin resins, such as an apparatus equipped with a pyrolysis tank for vaporizing the resin composition. Furthermore, the apparatus used in this manufacturing method may include a cooler for cooling the obtained gas and a condensation unit for condensing the gas from the pyrolysis tank to generate oil.

[0090] Examples of methods for thermally decomposing the resin composition include (i) decomposition using an electric furnace, (ii) decomposition using molten ferric pyrolysis, and (iii) decomposition using a fluidized bed catalytic converter. These methods can be used individually or in combination. Of these, method (i) is preferred.

[0091] The following explains these methods.

[0092] [(i) Decomposition using an electric furnace]

[0093] As a method of decomposition using an electric furnace, the resin composition is simply filled into an electric furnace (thermal decomposition tank) equipped with a heater, and then heated using the heater. Furthermore, in the case of decomposition using an electric furnace, the apparatus can be equipped with a cooler to cool the resulting decomposition gas.

[0094] When decomposing the resin composition by means of an electric furnace, it is preferable to inject carrier gas simultaneously.

[0095] The flow rate of the carrier gas varies depending on the size of the pyrolysis tank and is not particularly limited. For example, when the capacity of the pyrolysis tank is 500 mL, the flow rate of the carrier gas is 0.05 L / min to 0.5 L / min.

[0096] Furthermore, from the perspective of thermal decomposition efficiency, it is preferable to carry out the decomposition of the resin composition while stirring.

[0097] [(ii) Decomposition using ferric pyrosulfite liquid]

[0098] As a method for decomposing ferric pyrosulfite, for example, a method can be described in which heated ferric pyrosulfite is brought into contact with a resin composition in a thermal decomposition tank under normal pressure and in the absence of air, thereby decomposing the resin composition.

[0099] The pyruvic acid refers to the supernatant portion of the distillate produced during the dry distillation of wood. Furthermore, the pyruvic acid iron solution refers to a liquid with a pH of 1.5–7 obtained by dissolving iron in wood vinegar. The wood vinegar contains organic acids (such as acetic acid), alcohols, carbonyl compounds, and aromatic compounds (such as phenols and furans) derived from wood.

[0100] From the perspective of thermal decomposition efficiency, the amount of the ferric pyrolysis solution is typically 10 to 40 parts by mass relative to 100 parts by mass of the resin composition, preferably 15 to 35 parts by mass, and particularly preferably 20 to 25 parts by mass.

[0101] Furthermore, the amount of ferric pyrosilicon liquid is preferably 20% to 60% of the internal volume of the pyrolysis tank. If the amount of ferric pyrosilicon liquid is too small, less resin composition comes into contact with the ferric pyrosilicon liquid, and the processing time tends to be longer. In addition, if the amount is too large, the ferric pyrosilicon liquid must be drained frequently and the decomposition residue must be decomposed, which tends to complicate the operation.

[0102] As described above, the decomposition of the resin composition must be carried out under conditions where air is absent. Therefore, it is preferable to inject a carrier gas while decomposing the resin composition.

[0103] Examples of carrier gases include rare gases such as helium, nitrogen, and carbon dioxide.

[0104] The flow rate of the carrier gas varies depending on the size of the pyrolysis tank and is not particularly limited. For example, when the capacity of the pyrolysis tank is 500 mL, the flow rate of the carrier gas is 0.05 L / min to 0.5 L / min.

[0105] Furthermore, from the perspective of thermal decomposition efficiency, it is preferable to carry out the decomposition of the resin composition while stirring.

[0106] [(iii) A method for decomposition using a fluidized bed catalytic converter]

[0107] As the fluidized catalytic converter, a device commonly used in the field of petroleum refining can be used. Basically, it consists of a reaction tower (reactor), a catalyst / product oil separator, an oil removal section on the catalyst surface, and a catalyst regeneration tower, in which the catalyst flows and circulates.

[0108] There are no particular limitations on the decomposition method using fluidized bed catalytic converters. Examples include UOP's UOP type, MWKellogg's superpositive flow type, and IFP's R2R type.

[0109] The processing conditions are adapted to the range commonly used in fluid catalytic cracking of petroleum. For example, the reactor pressure is approximately 0.1–3.0 kg / cm². 2 G, the mass ratio of catalyst to EVOH resin (catalyst / EVOH resin) is approximately 4–8, the temperature of the catalyst regeneration tower is approximately 500℃–800℃, and the pressure of the catalyst regeneration tower is approximately 0.1 kg / cm³. 2 G~3.0kg / cm2 G.

[0110] The manufacturing method comprises: a first step, in the methods (i) to (iii), heating at a temperature of 240°C to 450°C and maintaining the temperature within a temperature range of ±30°C of the heating temperature to remove the obtained gas; and a second step, heating at a temperature higher than the heating temperature of the first step and exceeding 400°C.

[0111] [First Process]

[0112] The first step includes heating the gas at a temperature range of 240°C to 450°C, maintaining the temperature, and then removing the resulting gas.

[0113] Oxygen-containing compounds that cause corrosion and decomposition inhibition of equipment during naphtha cracking of naphtha containing oleochemical compositions are generated during the thermal decomposition of plastics containing EVOH resins in a specific temperature range. Therefore, in this manufacturing method, the resin composition is heated in a specific temperature range of 240°C to 450°C, which preferentially generates oxygen-containing compounds, initially separating them and thereby reducing the proportion of oxygen-containing compounds.

[0114] The heating temperature (including the temperature to be maintained) in the first step only needs to be in the range of 240°C to 450°C. In particular, from the viewpoint of generating a large amount of oxygen-containing compounds, it is preferable to raise the temperature to 300°C to 430°C, more preferably 310°C to 420°C, even more preferably 320°C to 410°C, and particularly preferably 340°C to 400°C. When the temperature after raising the temperature is within the range described above, oxygen-containing compounds can be generated efficiently in the first step, which can reduce the proportion of oxygen-containing compounds and the like in the oil-based composition and increase the proportion of hydrocarbon compounds.

[0115] The heating time in the first step refers to the total time for heating and holding within a temperature range of 240℃ to 450℃. Thus, in the first step, the temperature is raised within the range of 240℃ to 450℃, and the temperature is maintained once a specific temperature is reached, thereby enabling two-stage thermal decomposition.

[0116] The heating time in the first step is preferably 5 minutes or more and less than 60 minutes, more preferably 7 minutes or more and less than 50 minutes, and particularly preferably 10 minutes or more and less than 40 minutes.

[0117] In addition, the heating time is preferably 3 minutes or more and 50 minutes or less, and the holding time is preferably 2 minutes or more and 30 minutes or less.

[0118] When the heating time is within the specified range, there is a tendency to increase the yield of the oiling composition, and furthermore, there is a tendency to sufficiently reduce the oxygen-containing compounds contained in the oiling composition.

[0119] In this manufacturing method, by using known means to separate the gas containing a large amount of oxygen-containing compounds generated in the first step from the thermal decomposition products obtained in the second step described later, the proportion of hydrocarbons contained in the oily composition obtained after the second step can be increased.

[0120] The gas obtained in the first process can be separated in a gaseous state using known methods, or it can be cooled below the dew point and separated in a liquid state.

[0121] [Second Process]

[0122] The second step is a heating process at a temperature higher than that of the first step, exceeding 400°C. Furthermore, in this second step, hydrocarbon recovery is preferred. It should be noted that in this manufacturing method, the second step is considered to begin from the point of reheating after the initial heating and holding in the first step.

[0123] The heating temperature in the second process is higher than that in the first process and exceeds 400°C, preferably exceeding 400°C but below 600°C, more preferably 430°C to 590°C, even more preferably 440°C to 580°C, and particularly preferably 450°C to 550°C.

[0124] When the heating temperature of the second process is within the specified range, there is a tendency for excellent thermal decomposition efficiency.

[0125] In addition, the heating time in the second process refers to the time spent heating at a temperature higher than that in the first process and exceeding 400°C. In the heating of the second process, it is necessary to raise the temperature to a higher temperature than that in the first process, but it is not necessary to set a holding time.

[0126] The heating time in the second step is preferably 10 minutes or more and 45 minutes or less, more preferably 20 minutes or more and 40 minutes or less. When the heating time is within the specified range, there is a tendency for excellent thermal decomposition efficiency.

[0127] By recovering the hydrocarbon-containing gas obtained in the second step, a thermal decomposition product (oil-based composition) can be obtained.

[0128] The hydrocarbon-containing gas obtained in the second step can be liquefied and recovered by cooling it below the dew point of the decomposition gas using a known condensation unit.

[0129] When the apparatus used in this manufacturing method is equipped with a cooler, it is preferable to cool the gases obtained in the first and second steps using the cooler. The temperature of the cooler is typically 0°C to 50°C, preferably 10°C to 45°C, more preferably 20°C to 40°C, and particularly preferably 30°C to 35°C. By cooling the gases obtained in the first and second steps using the cooler, gas components with boiling points higher than the cooler temperature are liquefied and returned to the thermal decomposition tank, thus tending to reduce impurities contained in the gas.

[0130] Furthermore, the oiled composition obtained by the method described in (ii) contains components derived from molten ferric pyrosulfite, and therefore tends to become acidic. Therefore, if the oiled composition is acidic, neutralization is preferable. Known methods can be used as the neutralization method.

[0131] Furthermore, in the first and second processes, catalytic cracking is preferably carried out using a catalyst.

[0132] Examples of catalysts include, for example, FCC catalysts and FCC waste catalysts. They can be used alone or in combination of two or more.

[0133] The FCC catalyst refers to a synthetic zeolite-based solid acid catalyst used in the fluid catalyst cracking (FCC) process of petroleum, with Al2O3 as the main component and small amounts of Na, Fe, C, V, Ni, Sb, etc. Furthermore, the FCC waste catalyst refers to the catalyst obtained by regenerating the aforementioned FCC catalyst.

[0134] These FCC catalysts and FCC waste catalysts have an average specific gravity of 0.74 to 0.91, which is roughly the same as that of the resin composition. Therefore, they can be fully mixed with the resin composition in the pyrolysis tank.

[0135] The average particle size of the FCC catalyst and the spent FCC catalyst is typically 40 μm to 80 μm.

[0136] In addition, the amount of FCC catalyst and FCC waste catalyst used is generally 5 to 35 parts by mass relative to 100 parts by mass of the resin composition, preferably 10 to 30 parts by mass, and particularly preferably 15 to 25 parts by mass.

[0137] [Distillation process]

[0138] Preferably, the thermally decomposed product (oil-based composition) obtained in the second step is distilled to remove impurities such as water and tar. That is, the manufacturing method preferably includes a distillation step after the second step.

[0139] For example, the distillation conditions in the distillation process are preferably a pressure of 100 mmHg to 760 mmHg and a distillation temperature of 70°C to 250°C, more preferably 80°C to 230°C, and even more preferably 90°C to 210°C. When the distillation conditions are within the range described above, there is a tendency to obtain an oily composition with fewer impurities.

[0140] Furthermore, the thermally decomposed product (oiled composition) obtained through the second process can be subjected to centrifugal separation or other methods to remove impurities such as water and tar.

[0141] The petrochemical composition obtained by this manufacturing method is preferably subjected to a hydrogenation reaction using a hydrorefining catalyst used in the catalytic hydrorefining of petroleum. By carrying out the hydrogenation reaction, the content of oxygen-containing compounds in the petrochemical composition can be further reduced.

[0142] The thermal decomposition products of the resin composition are typically present in a proportion of 10% by mass or more relative to the total oiled composition, preferably 30% by mass or more, and particularly preferably 50% by mass or more.

[0143] The proportion of hydrocarbons contained in the oleochemical composition is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more, relative to the total oleochemical composition.

[0144] It should be noted that the proportion of hydrocarbons contained in the oil-based composition can be determined by GC / MS.

[0145] The oleochemical composition obtained by this manufacturing method can be used as a naphtha feedstock. Furthermore, naphtha containing the oleochemical composition can be subjected to conventional naphtha cracking treatment to obtain recycled chemical feedstock.

[0146] The oleochemical composition obtained by this manufacturing method has a high hydrocarbon content, which makes it less likely to cause equipment corrosion and decomposition inhibition during naphtha cracking, thus enabling the stable production of recycled chemical raw materials.

[0147] Examples of regenerated chemical feedstocks derived from naphtha containing the aforementioned oleochemical composition include, for instance, ethylene, propylene, 1-butene, butadiene, isoprene, benzene, toluene, xylene, styrene, and other unsaturated hydrocarbons that are useful as petrochemical feedstocks. Among these, ethylene and / or propylene are preferred from the perspective of their potential to become feedstocks for a wide range of products; more preferably, ethylene or propylene; and most preferably, ethylene.

[0148] The resulting recycled chemical raw materials are preferably used as monomer compositions comprising the recycled chemical raw materials.

[0149] The monomer composition must contain the recycled chemical raw material. Furthermore, the monomer composition may contain other components to a extent that does not impair the effects of the invention. Examples of other components include monomers other than the recycled chemical raw material, and the compounding agents described in the resin composition.

[0150] Other monomers besides the aforementioned recycled chemical raw materials include, for example, monomers from petrochemical raw materials and monomers obtained by reacting recycled chemical raw materials. Examples of monomers obtained by reacting the aforementioned recycled chemical raw materials include ethylene vinyl acetate monomers.

[0151] Furthermore, the monomer composition can be polymerized to produce a resin composition containing a polymer. As for the polymerization method of the monomer composition, any existing and known polymerization method may be used.

[0152] Examples of such polymers include ethylene-vinyl acetate copolymers, which can be saponified to obtain EVOH resin.

[0153] Furthermore, the resin composition can also be molded to obtain a molded article. As for the molding method of the resin composition, any existing and known molding method can be used.

[0154] Thus, embodiments of the present invention can shorten the thermal decomposition time for obtaining an oleomeric composition from a resin composition containing EVOH resin. Furthermore, the resulting oleomeric composition has a high hydrocarbon content, thus enabling the stable acquisition of recycled chemical raw materials, subsequent polymers, and molded articles, making it suitable as a chemical recycling method.

[0155] Example

[0156] The following examples illustrate the present invention in further detail, but the present invention is not limited to these examples as long as it does not deviate from its spirit. It should be noted that in the examples, "parts" and "%" refer to mass standards.

[0157] The materials used in the following embodiments and comparative examples are described below.

[0158] • EVOH resin (A): SoarnoL DC3203RB manufactured by Mitsubishi Chemical Corporation: 32 mol% ethylene structural unit content, MFR (210℃, 2160g load) 3.8g / 10min, saponification degree 99.9 mol%.

[0159] • Polyethylene (B): NOVATEC UF240 manufactured by Nippon Polyethylene Co., Ltd., MFR (190℃, load 2160g) 2.1g / 10min, density 0.920g / cm³ 3 .

[0160] • Adhesive resin (C): LyondellBasell Plexar (registered trademark) PX3236, MFR (190°C, load 2160g) 2.0g / 10min, density 0.922g / cm³ 3 .

[0161] [Manufacturing of multilayer structures (resin compositions)]

[0162] EVOH resin (A), polyethylene (B), and adhesive resin (C) are supplied to a multilayer co-extrusion film forming apparatus. Through multilayer co-extrusion molding under the following conditions, a multilayer structure (resin composition) with three types of five-layer structures (B layer / C layer / A layer / C layer / B layer) is obtained. The thickness (μm) of each layer of the multilayer structure (resin composition) is 40 / 5 / 10 / 5 / 40. It should be noted that the EVOH resin content is 10% relative to the total resin composition.

[0163] [Multi-layer co-extrusion molding conditions]

[0164] • (A) Layer extruder: 40mmφ single screw extruder (barrel temperature: 210℃).

[0165] • (B) Layer extruder: 40mmφ single screw extruder (barrel temperature: 230℃).

[0166] • (B) Layer extruder: 50mmφ single screw extruder (barrel temperature: 230℃).

[0167] • (B) Layer extruder: 32mmφ single screw extruder (barrel temperature: 230℃).

[0168] • (C) Layer extruder: 32mmφ single screw extruder (barrel temperature: 210℃).

[0169] • Die head: Five types of seven-layer feed block type T-die heads.

[0170] • Traction speed: 11 m / min.

[0171] Roller temperature: 80℃.

[0172] <Example 1>

[0173] 2 mg of the multilayer structure (resin composition) was weighed in a platinum boat and placed in a TPD-MS. Under a helium atmosphere, the temperature was increased from 240°C to 400°C over 8 minutes at a rate of 20°C / min, and then held at 400°C for 10 minutes, recovering the generated decomposition gases (first step). Temperature variations during holding were within ±30°C. Then, the mixture was heated at 500°C for 35 minutes to achieve complete thermal decomposition, thereby obtaining a gaseous oiled composition containing the thermal decomposition products of EVOH resin (second step).

[0174] Here, "complete thermal decomposition" refers to the point in time when no gas production can be detected during the heating process.

[0175] <Example 2>

[0176] 2 mg of the multilayer structure (resin composition) was weighed into a platinum boat and placed in a TPD-MS. Under a helium atmosphere, the temperature was increased from 240°C to 350°C over 5.5 minutes at a rate of 20°C / min, and then held at 350°C for 30 minutes, recovering the generated decomposition gases (first step). Temperature variations during holding were within ±30°C. Then, the mixture was heated to 500°C for 15 minutes to achieve complete thermal decomposition, thereby obtaining a gaseous oiled composition containing the thermal decomposition products of EVOH resin (second step).

[0177] <Comparative Example 1>

[0178] Weigh 2 mg of the multilayer structure (resin composition) in a platinum boat, place it in a TPD-MS, and heat it to 500°C in 13 minutes at a heating rate of 20°C / min under a helium atmosphere. Then heat it at 500°C for 35 minutes and completely thermally decompose it without performing a second process, thereby obtaining a gaseous oiled composition containing the thermal decomposition product of EVOH resin.

[0179] <Comparative Example 2>

[0180] Weigh 2 mg of the multilayer structure (resin composition) in a platinum boat, place it in a TPD-MS, and heat it to 350°C in 5.5 minutes at a heating rate of 20°C / min under a helium atmosphere. Then heat it at 350°C for 65 minutes and completely thermally decompose it without performing a second process, thereby obtaining a gaseous oiled composition containing the thermal decomposition product of EVOH resin.

[0181] The hydrocarbon content and oxygen content of the gaseous oily compositions obtained in Examples 1 and 2, and Comparative Examples 1 and 2 were determined according to the method shown below. The results are shown in Table 1.

[0182] [Ratio of hydrocarbons]

[0183] Compositional analysis of the gaseous oiled composition was performed using GC / MS to calculate the proportion of hydrocarbons in all generated fragments.

[0184] [Table 1]

[0185]

[0186] As can be seen from the results in Table 1, the hydrocarbon content of the oleochemical compositions obtained by the manufacturing methods of Examples 1 and 2 is more than 90%, and there are few other impurities that cause corrosion and decomposition inhibition of equipment during naphtha cracking.

[0187] On the other hand, the hydrocarbon content of the oleochemical composition obtained by the manufacturing method of Comparative Example 1 is as low as 70%, which is believed to cause corrosion and decomposition inhibition of equipment during naphtha cracking treatment.

[0188] Furthermore, the manufacturing method of Comparative Example 2 requires a long time of 70.5 minutes until complete thermal decomposition, indicating poor thermal decomposition efficiency.

[0189] The embodiments described illustrate specific aspects of the invention, but are merely examples and not intended to be limiting. It is intended that various modifications, obvious to those skilled in the art, fall within the scope of the invention.

[0190] Industrial availability

[0191] The manufacturing method produces a high proportion of hydrocarbons and a shorter thermal decomposition time. Furthermore, the resulting oleochemical composition has a high proportion of hydrocarbons, thus it is less likely to cause equipment corrosion and decomposition inhibition during naphtha cracking and is suitable for chemical recycling.

Claims

1. A method for manufacturing an oleochemical composition, the method comprising: In the first step, the resin composition containing ethylene-vinyl alcohol copolymer (A) is heated at a temperature of 240°C to 450°C, and then maintained within a temperature range of ±30°C of the heating temperature to remove the resulting gas; and The second step involves heating at a temperature higher than that of the first step, exceeding 400°C.

2. The method for manufacturing the oil-based composition according to claim 1, wherein, The heating temperature in the first process is 300℃~430℃.

3. The method for manufacturing the oil-based composition according to claim 1 or 2, wherein, The heating temperature in the second process is above 400°C but below 600°C.

4. The method for manufacturing the oil-based composition according to claim 1 or 2, wherein, The heating time for the first process is more than 5 minutes and less than 60 minutes.

5. The method for manufacturing the oil-based composition according to claim 1 or 2, wherein, The heating time for the second process is more than 10 minutes and less than 45 minutes.

6. The method for manufacturing the oil-based composition according to claim 1 or 2, wherein, The proportion of hydrocarbons in the oleochemical composition is 50% or more by mass relative to the total oleochemical composition.

7. The method for manufacturing the oil-based composition according to claim 1 or 2, wherein, Hydrocarbons are recovered in the second process.

8. The method for manufacturing the oil-based composition according to claim 1 or 2, wherein, The method for manufacturing the oil-based composition includes a distillation step after the second step.

9. The method for manufacturing the oil-based composition according to claim 8, wherein, In the distillation process, distillation is carried out at a pressure of 100 mmHg to 760 mmHg and a temperature of 70°C to 250°C.

10. A chemical recycling method, said chemical recycling method using the method for manufacturing the oily composition according to any one of claims 1 to 9.

11. A method for manufacturing a recycled chemical raw material, wherein the method involves subjecting naphtha containing an oleochemical composition obtained by the method for manufacturing an oleochemical composition according to any one of claims 1 to 9 to naphtha cracking treatment to obtain the recycled chemical raw material.

12. The method for manufacturing recycled chemical raw materials according to claim 11, wherein, The recycled chemical feedstock is ethylene and / or propylene.

13. A method for manufacturing a polymer, said polymer manufacturing method comprising polymerizing a monomer composition of a recycled chemical raw material obtained by the method for manufacturing recycled chemical raw materials according to claim 11 to obtain the polymer.

14. A method for manufacturing a molded article, the method comprising molding a resin composition of a polymer obtained by the method for manufacturing a polymer according to claim 13 to obtain the molded article.

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