Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/04—Disintegrating plastics, e.g. by milling
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D9/00—Chemical paint or ink removers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D9/00—Chemical paint or ink removers
  • C09D9/04—Chemical paint or ink removers with surface-active agents
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/62—Plastics recycling; Rubber recycling

Definitions

• the present invention relates to a method for separating and collecting a laminate having a plastic film layer, and a method for producing recycled plastic pellets using crushed plastic collected by the method.
• Non-Patent Document 1 One of the reasons why the recycling rate continues to be so low is the difficulty of the separate collection system.
• PE polyethylene
• PP polypropylene
• many plastic products such as laminated films are laminated with different types of plastic materials adhered to each other, making it difficult to separate and collect each material. Therefore, construction of a recycling system capable of easily separating and recovering waste plastics is strongly desired.
• Patent Document 1 discloses that after dissolving an aluminum layer from a crushed multilayer film with an alkali, the multilayer film is separated by the difference in specific gravity, and then selectively melted in a solvent.
• a recycling method is proposed by separating the components, and Patent Document 2 proposes processes of crushing the printed film, removing the ink, rinsing, and drying, but all the processes are long and complicated.
• Patent Document 3 discloses a method of removing ink from a printed film in a roll state using a solvent and a non-abrasive cloth
• Patent Document 4 discloses a method of removing ink from a printed film in a roll state using a solvent, a brush, and a wiper. Although it provides a method of removing ink using a blade, it only produces a non-printed film by removing ink from a roll of film.
• the ink removal or separation process is carried out after the process of dry crushing the laminated film, and the process is common, and the process is long and complicated.
• the problem to be solved by the present invention is to provide a method for easily separating and recovering a laminate having a plastic film layer, and a method for producing high-quality recycled plastic pellets using crushed plastics recovered by the method. to provide.
• the present inventors have made intensive studies to solve the above-mentioned problems, and as a result, after the step of crushing the laminated film under wet conditions, the crushed laminate is heated and stirred in a cleaning liquid. As a result, the inventors have found an easy method for regenerating a plastic laminate into a high-quality recycled raw material.
• the present invention is a method for separating and recovering a laminate having at least a plastic film layer and a layer selected from a plastic film layer, a deposited film layer and a metal foil layer, A step 1 of crushing the laminate in water or a washing liquid; Step 2 of separating the laminate into single layers by heating and stirring the crushed laminate in a release agent to provide a method for separating and recovering a laminate characterized by having
• the present invention also provides a method for producing recycled plastic pellets, comprising recovering each single layer of the crushed plastic material separated into single layers by the method for separating and recovering a laminate described above, and molding the recovered material with a molding machine after melting it. .
• a plastic laminate can be separated into single layers, and crushed single-layer films can be easily collected, sorted, and reused.
• the method of the present invention not only a laminated film in which a printed layer is exposed on the film surface (surface printing), but also a laminated film in which a printed layer is provided between a plurality of films (reverse printing). Even in plastic laminates having various configurations, the plastic laminate can be separated into single layers, and the ink layer can be easily peeled off.
• the film can be separated into single layers and the ink layer can be easily peeled off, so that the method for separating and recovering the plastic laminate can be facilitated, and , the collected plastic can be reused as a high-quality recycled plastic raw material.
• the method for separating and recovering a laminate of the present invention has a step 1 of crushing the laminate in water or a washing liquid.
• the method of pulverizing the laminate in water or a washing liquid is not particularly limited, and any known method can be used. Among them, it is preferable to use a wet crusher capable of carrying out crushing and pumping at the same time in water or washing liquid. When using a wet crusher, the laminate can be efficiently crushed and the laminated laminate can be separated into individual layers.
• step 1 By crushing the laminate in step 1, the laminate can be easily peeled off completely into single layers in step 2, which will be described later.
• the laminate may be crushed, and the crushed laminate may be in a state in which at least a part such as an end portion is partially peeled, or each layer may be completely peeled. Also, each layer does not have to be peeled off.
• wet crusher One example of a wet crusher preferably used in step 1 is a wet crusher capable of simultaneously crushing, dispersing, mixing and pumping solids in a liquid. Specifically, a crusher having a mechanism for crushing solid matter in a liquid by shearing force and/or frictional force and having a mechanism for crushing and pumping a plastic laminate is preferred. Examples of such wet crushers include wet crushing pumps, colloid mills, grinders, and the like.
• the wet crushing pump preferably has a mechanism for crushing the solids with a fixed blade and a rotating blade while pumping the solids in the liquid.
• a more preferred mechanism is a cutting blade, crushing impeller, shroud ring, and grid. It is a mechanism that crushes in three stages by combining four parts.
• the wet crushing pump crushes the plastic laminate in three stages.
• the plastic laminate is roughly cut by the fixed blade cutting edge and the inlet edge of the rotary blade crushing impeller, and then stirred and pumped by the axial crushing impeller, and some plastic laminate is cut into the fixed blade shroud It hits the cutting edge of the ring and is cut.
• the laminated film that has passed through the crushing impeller is further finely crushed and stirred between the grids, passed through the grid and pressurized by the pressure impeller, and then pumped to the next step.
• the pumping speed is not particularly limited, it is preferably 0.03 m 3 /min or more in consideration of the peeling of the ink layer and the peeling and separation efficiency when separating the plastic laminate into layers.
• the upper limit of the pumping speed is not particularly limited, and the standard operating speed of the apparatus, for example, 1.4 m 3 /min, is sufficient to separate the ink and separate the plastic laminate into single layers.
• the grid shape is not particularly limited. Since the grid diameter is related to the size of the laminated film after crushing, the grid diameter is preferably 0.1 to 50 mm, and more preferably 1 to 20 mm considering the crushing efficiency and the size of the laminated film after crushing. .
• wet crushing pumps include Husqvarna Zenoah's KD series, Nikuni's Sancutter series, Furukawa Sanki Systems' Disintegrator series, Aikawa Iron Works Inc.'s Incrusher series, and Sanwa Hydrotech's Scatter. can be exemplified.
• a colloid mill as used in the present invention is a machine used to reduce particle size in dispersed systems where the particles are suspended in a liquid.
• a colloid mill consists of a rotor-stator combination, where the rotor rotates at high speed relative to the fixed stator. High speed rotation is used to reduce particle size in liquids due to the high levels of shear produced.
• the crushing part of the colloid mill consists of a combination of a truncated cone-shaped rotor with teeth and a stator, and the rotor and stator have a tapered shape that narrows as it approaches the discharge port.
• the laminated film is repeatedly subjected to strong shearing, compression, and impact in a ring-shaped gap that narrows as it approaches the discharge port, and is crushed.
• a specific colloid mill is not particularly limited as long as it is a dispersing machine generally called a colloid mill.
• An example can be Cavitron of the company.
• the grinder preferably has a mechanism for crushing the solid matter put between the stone mills by shearing or friction while rotating a set of upper and lower stone mills in the liquid. Those that can be pulverized to
• the size of the crushed material can be adjusted by adjusting the distance between the upper and lower set of millstones, and is usually finely pulverized to 500 ⁇ m or less, preferably 300 ⁇ m or less, more preferably 200 ⁇ m or less.
• each layer of the laminate is separated into a single layer, and the space for storing the crushed material can be reduced, facilitating inventory management.
• the process can be simplified because the material can be put into a kneader without going through a compressor or the like.
• the lower limit of the size of the crushed material is preferably 10 ⁇ m or more, preferably 30 ⁇ m or more, and more preferably 50 ⁇ m or more, in order to facilitate recovery.
• the rotation speed and water flow speed are not particularly limited.
• a specific grinding machine is Masuko Sangyo Co., Ltd.'s Super Mascolloider.
• a part or all of the plastic laminate can be separated into single-layer films or plastic substrates by crushing in water or a washing liquid using the wet crusher.
• most plastic laminates are provided with a printing ink layer for displaying the product name and the like and for adding decoration.
• Printing machines, offset printers, inkjet printers, etc. are often used and printed with organic solvent-based printing inks, water-based or active energy ray-curable inks.
• the plastic laminate may be crushed in a cleaning liquid containing water containing a cleaning component or a stripping component. good.
• the ink layer provided on the plastic laminate can be peeled off and the plastic laminate can be separated into single layers at the same time.
• gravure inks and flexographic inks are most commonly used for plastic laminated films, including those for food packaging.
• the printed ink layer can also be peeled off. Therefore, it is efficient.
• the laminated film is laminated with a metal foil or vapor deposition film such as aluminum. In the present invention, the metal foil or vapor deposition film can also be peeled off or dissolved.
• each layer constituting the laminate may be separated into a single layer by crushing in water, or a part of the crushed laminate may be partially separated.
• the ink layer provided on the plastic laminate need not be completely removed from the plastic film in step 1, and may be partially adhered or not removed from the ink layer. .
• crushing may be performed using water as it is, or crushing may be performed using a cleaning liquid containing water containing a cleaning or peeling component such as an inorganic base or a surfactant, or other components.
• a cleaning or peeling component such as an inorganic base or a surfactant, or other components.
• the washing solution one or more of the following components can be used in combination with water.
• inorganic base As an aqueous washing solution that can be used in step 1, water containing an inorganic base can be used.
• inorganic bases include sodium hydroxide and potassium hydroxide. These inorganic bases are contained at a concentration of 0.1 to 10% by weight, more preferably 0.1 to 5% by weight, based on the total amount of the aqueous cleaning solution. Further, the pH is preferably 10 or higher.
• surfactant As the aqueous cleaning solution that can be used in step 1, water containing a surfactant can be used.
• surfactants are not particularly limited, and known surfactants can be used. Examples include anionic surfactants, nonionic surfactants, amphoteric surfactants, and cationic surfactants. .
• Nonionic surfactants generally include, for example, polyoxyalkylene alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, Polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, fatty acid alkylolamide, alkylalkanolamide, acetylene glycols, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers, among others, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphen
• a polyoxyalkylene alkyl ether surfactant containing at least one compound represented by the general formula (1) It is preferably an aqueous cleaning liquid containing.
• R 1 represents a linear or branched alkyl group, alkenyl group or octylphenol group, n 1 represents the average number of added moles, and X 1 represents hydrogen or a short-chain alkyl group.
• a linear or branched alkyl group or alkenyl group having 10 or more carbon atoms represented by R 1 in general formula (1) is preferred.
• the specific number of carbon atoms is a decyl group with 10 carbon atoms, a lauryl group with 12 carbon atoms, a tridecyl group with 13 carbon atoms, a myristyl group with 14 carbon atoms, a cetyl group with 16 carbon atoms, and a carbon atom.
• Oleyl group and stearyl group of number 18 can be mentioned.
• Specific products include Noigen series, DSK NL-Dash series, and DKS-NL series manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Nonion series manufactured by NOF Corporation, Emulgen series manufactured by Kao Corporation, and Leox manufactured by Lion Corporation.
• nonionic surfactants represented by the general formula (1) among the series, the Leocol series, the Lionol series, etc. if the number of carbon atoms represented by R 1 is 10 or more, it is applicable, but is limited to these. not a thing
• the HLB value of the polyoxyalkylene alkyl ether-based surfactant represented by the general formula (1) is not particularly limited.
• a specific surfactant having 10 or more carbon atoms represented by R 1 and an HLB value of less than 12.5 is Daiichi Kogyo
• R represents a linear or branched alkyl group or alkenyl group having 10 or more carbon atoms and an HLB value of 12.5 or more.
• R1 in general formula ( 1 ) is an octylphenol group
• octylphenol ethoxylate is preferred.
• Specific products include, but are not limited to, Dow Chemical Company's TRITON (registered trademark) series, Rhodia's Igepal CA series, Shell Chemicals' Nonidet P series, and Nikko Chemicals' Nikkol OP series. is not.
• amphoteric surfactant is preferably a betaine-type double-sided active agent, for example, an amphoteric interface of an alkylcarboxybetaine skeleton or an alkylamidocarboxybetaine skeleton containing at least one compound represented by the general formula (2a). It is more preferred to contain an active agent.
• R1 preferably represents a hydrogen atom.
• the compound represented by general formula (2a) is preferably an amphoteric surfactant having an alkylcarboxybetaine skeleton represented by general formula (2a-1).
• n represents the average number of added moles.
• n is preferably 8 or more, preferably 10 or more, and preferably 11 or more.
• Specific products corresponding to general formula (2a) include Nissan Anon BDF (registered trademark)-R, Nissan Anon BDF (registered trademark)-SF, Nissan Anon BDC-SF, and Nissan Anon BDL manufactured by NOF Corporation.
• -SF Amogen CB-H and Amogen HB-C manufactured by Daiichi Kogyo Seiyaku Co., Ltd.; Obazolin ISAB and the like.
• Amogen S, Amogen SH, and Amogen K manufactured by Daiichi Kogyo Seiyaku Co., Ltd. and Amphitol 20BS, Ambitol 24B, and Ambitol manufactured by Kao Corporation.
• Examples include, but are not limited to, ovazoline LB, ovazoline LB-SF, and the like.
• the betaine-type amphoteric surfactant may also have an imidazolinium betaine skeleton.
• Specific examples of such products include NISSAN ANON GLM-R and NISSAN ANON GLM-R-LV manufactured by NOF Corporation. , Amphithol 20Y-B manufactured by Kao Corporation, but not limited to these.
• amphoteric surfactant may be a surfactant represented by the following general formula (2b).
• R4-( NHC2H4 ) nb -N(R5)2 2b
• R4 represents a linear or branched alkyl group or alkenyl group
• nb represents an integer of 0 to 5
• R5 represents hydrogen, —CH 2 COONa, or —CH 2 COOH.
• two R5s present may be the same or different, and at least one R5 represents —CH 2 COONa.
• R4 preferably represents a linear alkyl group, and the number of carbon atoms in R4 is preferably 8 or more, preferably 10 or more, and preferably 12 or more.
• Specific products that fall under the general formula (2b) include Nissan Anon LG-R and Nissan Anon LA manufactured by NOF Corporation, but are not limited to these.
• amphoteric surfactant may also be an amine oxide type surfactant represented by the following general formula (2c).
• R6-N + (CH 3 ) 2 O - (2c) (In general formula (2c), R6 represents a linear or branched alkyl group or alkenyl group.) In general formula (2c), R6 preferably represents a linear alkyl group in general formula (2b), and the number of carbon atoms in R4 is preferably 8 or more, preferably 10 or more. , 12 or more.
• Specific products corresponding to general formula (2c) include Amogen AOL manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and Amphitol 20N manufactured by Kao Corporation, but are not limited to these.
• the cationic surfactant is preferably a cationic surfactant having a quaternary ammonium skeleton, for example, a cationic surfactant having a quaternary ammonium skeleton containing at least one compound represented by the general formula (3a). It is more preferred to contain an active agent.
• R1 is preferably a long-chain alkyl group or alkenyl group, specifically an al
• alkyl group having 10 to 25 carbon atoms is preferably an alkyl group having 10 to 25 carbon atoms, more preferably an alkyl group or alkenyl group having 12 to 22 carbon atoms.
• the alkyl group or alkenyl group may be linear or branched, preferably linear, more preferably linear alkyl.
• R2 and R3 preferably represent a straight-chain or branched-chain alkyl group or a straight-chain or branched-chain alkenyl group, and preferably represent a straight-chain or branched-chain alkyl group. Among them, it preferably represents a linear alkyl group having 1 to 3 carbon atoms, and more preferably represents a methyl group.
• R4 preferably represents a linear or branched alkyl group, a linear or branched alkenyl group or a phenyl group, more preferably a linear or branched alkyl group. Also, the terminal —CH 3 in the alkyl group or alkenyl group is preferably substituted with a carboxy group or a phenyl group.
• the number of carbon atoms in R4 is preferably 1 to 8, preferably 1 to 5, preferably 1 to 3, more preferably 1 or 2.
• R4 represents a methyl group
• R2 and R3 also preferably represent a methyl group
• general formula (3a) preferably represents an alkyltrimethylammonium skeleton.
• R4 represents an ethyl group
• the compound represented by general formula (3a) is preferably a cationic surfactant having a quaternary ammonium skeleton represented by general formula (3a-1).
• n represents the average number of added moles, and R4 has the same meaning as R4 in general formula (3a) according to claim 3.
• the number of carbon atoms represented by n is preferably 8 or more. The more the number of carbon atoms exceeds 8, the better the ink releasability.
• the specific number of carbon atoms is 8 octyl group with 9 carbon atoms, nonyl group with 10 carbon atoms, undecyl group with 11 carbon atoms, lauryl group with 12 carbon atoms, tridecyl group with 13 carbon atoms, myristyl with 14 carbon atoms C15 pentadecyl group, C16 cetyl group, C18 oleyl group, and stearyl group.
• Preferred groups for R4 are the same as in general formula (3a).
• These cationic surfactants having a quaternary ammonium skeleton are preferably of the quaternary ammonium skeleton salt type in which a salt is formed with a halogen, preferably form a salt with Cl- , more preferably with Br-. It is preferred to form a salt, more preferably with I ⁇ .
• a quaternary ammonium skeletal salt formed by forming a salt with a halogen accelerates the hydrolysis of the ink film by the nucleophilic action of the halogen, and is therefore considered to improve the releasability of the ink.
• alkyltrimethylammonium chloride-type dialkyldimethylammonium chloride-type, and alkylbenzalkonium chloride-type compounds are preferable.
• Specific products corresponding to general formula (3a) or (3a-1) include Nissan Cation MA, Nissan Cation SA, Nissan Cation BB, Nissan Cation FB, Nissan Cation PB-300, Nissan Cation ABT2-500, Nissan Cation AB, Nissan Cation AB-600, Nissan Cation VB-M Flake, Nissan Cation VB-F, Nissan Cation 2-DB-500E, Nissan Cation 2-DB-800E, Nissan Cation 2ABT, Nissan Cation 2-OLR, Nissan cation F 2 -50R, Nissan cation M 2 -100R, and Daiichi Kogyo Co., Ltd.
• cation TML manufactures cation TML, cation TMP, cation TMS, cation DDM-PG, cation BC-50, and cation TBB.
• Kotamine 24P, Kotamine 86P Conc, Kotamine 60W, Kotamine 86W, Sanizol C, and Sanizol B-50 are available from Kao Corporation, and Lipoguard C-50, Lipoguard T-28, and Lipoguard T-30 from Lion Corporation.
• the cationic surfactant preferably contains at least one compound represented by a primary to secondary alkanolamine skeleton, and contains at least one compound represented by a monoalkanolamine skeleton.
• the primary monoalkanolamine is preferably a lower alkanol having 1 to 4 carbon atoms, and specific examples thereof include monoethanolamine, 2-aminoisobutanol, and the like. Examples include N-methylethanolamine, 2-ethylaminoethanol, isopropanolamine and the like, but substances other than those exemplified can also be used as appropriate.
• these monoalkanolamine compounds can be used singly or in combination of two or more, and can also be used by mixing with water.
• These cationic surfactants having a monoalkanolamine skeleton are preferably in the form of monoalkanolamine salts forming salts with halogens, and preferably forming salts with Cl.sub.2.sup.-.
• the amount added is preferably 5% by weight or less, preferably 2% by weight or less, relative to the total amount of the aqueous cleaning solution.
• the lower limit of the surfactant is not particularly limited, and may be 0% by mass, but when a surfactant is contained, it is preferably 0.1% by mass or more.
• Alkylene glycol alkyl ether solvent As the aqueous cleaning solution that can be used in step 1, water containing an alkylene glycol alkyl ether solvent can be used. Preferably, it is an aqueous cleaning liquid containing 20% by weight or more of a solvent having an alkylene glycol alkyl ether skeleton represented by general formula (4).
• R 1 -O-[CH 2 -CH(X)-O]n 1 -R 2 (4) (In the general formula (4), R 1 is an alkyl group having 1 or more carbon atoms, R 2 is an alkyl group having 1 or more carbon atoms or hydrogen, n 1 is an integer of 1 to 3, X is hydrogen or indicates a methyl group.)
• alkylene glycol alkyl ethers represented by formula (4) water-soluble alkylene glycol alkyl ethers are more preferred.
• Examples of water-soluble alkylene glycol alkyl ethers represented by general formula (4) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether.
• ethylene glycol dipropyl ether ethylene glycol methyl ethyl ether, ethylene glycol methyl propyl ether, ethylene glycol ethyl propyl ether, ethylene glycol monobutyl ether, ethylene glycol-tert-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether , diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl propyl ether, diethylene glycol ethyl propyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene Glycol monopropyl ether, propylene glycol monobutyl ether, propylene
• alkylene glycol alkyl ethers can be used singly or in combination of two or more, and can also be used by mixing with water. There is no particular problem if the content of the alkylene glycol alkyl ether is 20% by weight or more, but when water is the medium, it is preferably 30% by weight or more, and most preferably 40% by weight or more. On the other hand, although the upper limit may be 100% by weight, it is preferable to use water as a medium from the viewpoint of environmental impact and safety.
• alkylene glycol alkyl ethers represented by general formula (4) More preferred are alkylene glycol monoalkyl ethers represented by general formula (5).
• R 2 O—[CH 2 —CH(X)—O]n 2 —H (5)
• R 2 represents an alkyl group having 1 or more carbon atoms
• n 2 represents an integer of 1 to 3
• X represents hydrogen or a methyl group.
• water-soluble alkylene glycol alkyl ethers represented by general formula (5) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether, and ethylene glycol-tert.
• R 2 is an alkyl group having 3 or more carbon atoms
• n 2 is 1 to 3
• X 2 is preferably hydrogen or a methyl group.
• ethylene glycol monopropyl ether ethylene glycol monobutyl ether, ethylene glycol-tert-butyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, etc.
• alkylene glycol alkyl ethers can be used singly or in combination of two or more, and can also be used by mixing with water.
• diethylene glycol monobutyl ether diethylene glycol monobutyl ether, ethylene glycol mono-tert-butyl ether, and propylene glycol monopropyl ether are particularly preferable in terms of environmental properties, flammability, and antifoaming properties.
• the water used in step 1 may contain an antifoaming agent.
• an antifoaming agent In step 1, a large amount of bubbles may be generated in the stirring and crushing steps, and if bubbles remain, they may overflow in the plastic film recovery step. In addition, in the process of crushing a plastic film, if a large amount of bubbles are involved in the cleaning liquid, the plastic substrate may not be crushed to a desired size.
• silicone compounds are particularly preferred in terms of their high antifoaming ability. .
• emulsion-type and self-emulsification-type silicone compounds are preferable.
• Specific antifoaming agents include X-50-1176, KS-530 and KS-537 manufactured by Shin-Etsu Chemical Co., Ltd. as self-emulsifying type, and KM-7750D and KM manufactured by Shin-Etsu Chemical Co., Ltd. as emulsion-type antifoaming agents. -7752, KM-98, FS Antifoam 025, FS Antifoam 80, FS Antifoam 92, FS Antifoam 93, DKQ1-1183, DKQ1-1247 manufactured by Nagase Chemspec, but not limited thereto.
• the liquid temperature of the water or cleaning liquid used in step 1 is not particularly limited as long as it can be maintained in a liquid state, but it is usually preferred that the liquid temperature is 15 to 90°C.
• the liquid temperature is 15 to 90°C.
• the optimum temperature for excellent cleaning effect varies depending on the type of surfactant, for example, 40° C. or higher is preferable, 65° C. or higher is preferable, and 85° C. or higher is preferable.
• the liquid temperature is not too high. It is preferably 20°C or less. Since the smaller the size of the laminate after crushing, the larger the cross-sectional area, the layers constituting the laminate are easily separated into single layers in step 2, and the separation and colorlessness of the ink layer are facilitated.
• the laminate separation and recovery method of the present invention has step 2 of heating and stirring the laminate crushed in step 1 in a release agent. By performing the step 2 after crushing the laminate in the step 1, each layer constituting the laminate can be easily peeled off.
• step 1 the laminate structure of the laminate is peeled off into a single layer, or a base is formed to facilitate the peeling of the laminate structure, and in step 2, the laminate is completely peeled off into a single layer.
• the ink layer can be peeled off in step 2 to make the plastic film colorless.
• the laminate has an ink layer, it is difficult to make the plastic colorless depending on the type of ink and the structure of the laminate.
• a base that makes it easy to peel is prepared, and in step 2, the laminate is separated into single layers and the ink layer is peeled off, so the ink layer can be easily peeled off regardless of the type of ink or the structure of the laminate. can.
• the plastic film from which the ink layer has been peeled off can be used for collection, sorting and recycling, and high-quality recycled plastic can be obtained because the ink has been removed.
• the release agent used in step 2 can be one that promotes separation of the laminate into single layers and facilitates easy separation of the ink layer from the plastic film having the ink layer.
• a release agent it is preferable to use one containing (a) a water-soluble solvent and (b) an inorganic base.
• the water-soluble solvent preferably contains one or more water-soluble alcohols or water-soluble solvents having a flash point of 21° C. or higher.
• a water-soluble solvent for the stripping agent By using a water-soluble solvent for the stripping agent, the hydroxide ions generated from the inorganic base contained in the stripping agent are less likely to be hydrated, so the nucleophilicity of the hydroxide ions increases. Since the ink layer peeling reaction can be advanced, it is effective for peeling the ink film.
• the water-soluble solvent having a flash point of 21° C. or higher is preferably a water-soluble solvent among the organic solvents that fall under the second petroleum class and the third petroleum class specified in the Fire Defense Law.
• water-soluble alcohols alcohols specified in the Fire Defense Law can be mentioned. Specific examples of these include 3-methoxy-3-methyl-1-butanol, diethylene glycol monobutyl ether, ethanol and the like, and these may be used alone or in combination.
• the release agent preferably contains a water-soluble solvent in the range of 20% by mass or more. If the content of the water-soluble solvent is less than 20% by mass, it becomes difficult to obtain sufficient effects such as peeling off the ink layer. From the viewpoint of the releasability of the ink layer, it is preferable that the release agent contains a large amount of water-soluble solvent. preferably 50% by mass or more, preferably 60% by mass or more, preferably 70% by mass or more, preferably 80% by mass or more, preferably 90% by mass or more, It is preferably at least 95% by mass.
• the inorganic base specifically includes sodium hydroxide and potassium hydroxide, and it is preferable to use potassium hydroxide. These inorganic bases are preferably contained in a concentration of 0.1 to 10% by weight, more preferably 0.1 to 5% by weight, based on the total amount of the ink remover.
• the pH is preferably 10 or higher, preferably 11 or higher, and more preferably 12 or higher.
• the release agent in step 2 may contain (c) water.
• water By including water in the release agent in step 2, work stability and environmental stability in step 2 can be improved.
• the content of water is preferably 80% by mass or less relative to the release agent. If the water content exceeds 80% by mass, it becomes difficult to obtain sufficient effects in separating the laminate into single layers and peeling off the ink layers.
• the ratio of the water-soluble solvent and water can be appropriately adjusted from the viewpoint of the peeling effect and safety of the plastic film and ink layer, but the weight ratio of the water-soluble solvent:water is in the range of 20:80 to 100:0. It is preferable to use in
• the lower limit of the ratio of the water-soluble solvent in the total amount of the water-soluble solvent and water is preferably 20% by mass, preferably 30% by mass, preferably 50% by mass, and 70% by mass. is preferably 80% by mass, preferably 90% by mass, and preferably 100% by mass.
• the release agent of step 2 may contain (d) a surfactant.
• Surfactants are not particularly limited, and known surfactants can be used. Examples include anionic surfactants, nonionic surfactants, amphoteric surfactants, and cationic surfactants. . As specific types of these surfactants, the same surfactants as those described as surfactants that can be contained in water in Step 1 can be used.
• the surfactant can be used alone or in combination of two or more.
• the amount added is preferably 5% by weight or less, preferably 2% by weight or less, relative to the total amount of the release agent.
• the lower limit of the surfactant is not particularly limited, and may be 0% by mass, but when a surfactant is contained, it is preferably 0.01% by mass or more.
• the temperature at which the washing liquid is stirred that is, the liquid temperature is not particularly limited. Since the cleaning effect of the release agent is higher when the liquid temperature is high, the temperature is preferably 40° C. or higher, preferably 50° C. or higher, and more preferably 60° C. or higher. The upper limit of the liquid temperature is not particularly limited as long as the liquid state can be maintained, but usually 90° C. or less is preferable.
• the equipment and method for stirring the crushed laminate in the cleaning liquid are not particularly limited, and known methods can be used. Specific examples include a device equipped with a motor equipped with a stirring blade that can stir the cleaning solution in the container, a device equipped with a device that generates ultrasonic waves, a device that can shake the entire container, a wet crusher, and the like. be done. A wet crusher similar to the crusher described in step 1 can be used. Strong stirring can be applied by using a wet crusher in step 2, so if part of the laminate cannot be completely separated into a single layer in step 1, it can be separated into a single layer in step 2. can be done.
• the crushed plastic material separated into monolayers in step 2 can be recovered for each monolayer.
• Equipment and methods for collecting crushed plastics are not particularly limited. can.
• the plastic laminate separated and recovered in Steps 1 and 2 is a laminate having at least a plastic film layer and a layer selected from a plastic film layer, a deposited film layer and a metal foil layer, and more specifically, , a laminate in which a plurality of layers such as an ink layer, an adhesive layer, and another plastic film are laminated on a plastic film.
• laminates include, without particular limitation, laminate films laminated and bonded with reactive adhesives used in food packaging and household goods, but of course non-reactive adhesives such as thermoplastic resins.
• a laminated film laminated with an adhesive and a laminated film obtained by heat-sealing by an extrusion lamination method can also be separated and recovered into individual single-layer films by the separating and recovering method of the present invention.
• a sheet-shaped or container-shaped laminate may be used.
• plastic laminates having various types of resin layers that have been discarded by recycling can be processed together without the need for re-separation.
• containers such as PET bottles, for example, use shrink labels, which are laminated films formed in a cylindrical shape, in order to display product names and provide decorativeness, and the shrink labels are consumed during recycling.
• shrink labels which are laminated films formed in a cylindrical shape, in order to display product names and provide decorativeness, and the shrink labels are consumed during recycling.
• the PET bottle main body and the shrink label are separated and discarded separately by an operator.
• the labels can be separated and the shrink labels can be separated into individual monolayer films.
• Laminated films laminated and bonded with a reactive adhesive often have an adhesive layer made of the reactive adhesive between at least two resin film layers, metal foil layers, or deposited film layers.
• the resin film layer is expressed as (F)
• the metal foil layer of the metal foil or vapor deposition film layer is expressed as (M)
• the adhesive layer such as the reactive adhesive is expressed as (M).
• AD the following configuration can be considered as a specific mode of the laminated film, but of course it is not limited to this.
• the laminated film which is the object of this separation and recovery method, may further have a paper layer, an oxygen absorbing layer, an anchor coat layer, an ink layer, a detachment primer layer provided to facilitate the detachment of the ink, etc. be.
• the ink layer is, for example, a printing ink printed with an organic solvent-based printing ink, water-based or active energy ray-curable ink using a gravure printing machine, a flexo printing machine, an offset printing machine, an inkjet printing machine, or the like. It may be an ink layer for multi-color printing using a plurality of ink types. In the present invention, the ink layer can be peeled off regardless of the type of ink by going through steps 1 and 2.
• the ink layer may be provided on the outermost layer of the laminated film, or may be provided between the resin film layer (F) and the adhesive layer (AD).
• the ink layer and the adhesive layer are bonded more firmly, making it more difficult to separate the ink layer.
• the ink layer can be effectively peeled off even in the configuration of reverse printing.
• the ink layer is present between the layers that make up the laminate, and the ink layer and the adhesive layer are more strongly bonded, so it is difficult to separate them into single layers and remove the ink layer.
• the film of F2 is partly peeled off in step 1, or if F2 is crushed in a state where it is easy to peel off, in step 2, the remaining layer structure can be easily peeled off and the ink layer can be removed. is.
• the resin film layer (F) functions as a base film layer (F1) or as a sealant layer (F2) that becomes a heat-sealed portion when forming a packaging material, when classified according to the required role.
• the resin film that serves as the base film layer (F1) includes polyolefin films such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, OPP (biaxially oriented polypropylene), and CPP (non-oriented polypropylene).
• polyolefin films such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, OPP (biaxially oriented polypropylene), and CPP (non-oriented polypropylene).
• polyester films such as polyethylene terephthalate (PET) and polybutylene terephthalate; polyamide films such as nylon 6, nylon 6,6 and metaxylene adipamide (N-MXD6); biodegradable films such as polylactic acid; Acrylonitrile-based film; Poly(meth)acrylic-based film; Polystyrene-based film; Polycarbonate-based film; Ethylene-vinyl acetate copolymer saponified product (EVOH)-based film; Films containing these pigments are included.
• a transparent vapor-deposited film obtained by vapor-depositing alumina, silica, or the like on these films may also be used.
• the surface of the film material may be subjected to various surface treatments such as flame treatment, corona discharge treatment, or chemical treatment such as primer.
• Flexible polymer films that serve as the sealant layer (F2) include polyethylene films, polypropylene films, polyolefin films such as ethylene-vinyl acetate copolymers, ionomer resins, EAA resins, EMAA resins, EMA resins, EMMA resins, raw A film of decomposed resin is preferred.
• CPP unstretched polypropylene
• VMCPP aluminum-deposited unstretched polypropylene film
• LLDPE linear low-density polyethylene
• LDPE low-density polyethylene
• HDPE high-density polyethylene
• VMLDPE aluminum-deposited Non-low-density polyethylene film
• Examples of the metal foil layer (M) include foils of metals with excellent ductility such as gold, silver, copper, zinc, iron, lead, tin and alloys thereof, steel, stainless steel and aluminum.
• the paper layer examples include natural paper and synthetic paper.
• the first and second sealant layers may be formed of materials similar to the sealant layers described above.
• Other layers may contain known additives and stabilizers, such as antistatic agents, non-reactive adhesive layers, easy-adhesion coating agents, plasticizers, lubricants, and antioxidants.
• Plastic laminate crushing process First, the plastic film laminate is sequentially put into a wet crusher filled with water or a washing liquid to obtain crushed plastics. At this time, the plastic film laminate may be cut into plastic pieces having a size of about 30 cm square, for example, and the pieces may be put into a wet crusher. Through the cutting process, the crushing in the wet crusher in the next process can be performed more efficiently.
• a known crusher can be used, and examples thereof include impact crushers such as hammer crushers and rotary crushers, shredders, and cutters.
• the size and shape of the cut plastic laminate piece are not particularly limited, but the maximum length of the plastic piece is preferably 50 cm or less, preferably 30 cm or less, preferably 20 cm or less, and preferably 10 cm or less.
• a laminate film obtained by cutting a laminate film roll into a size of about 30 cm square is pulled into a crushing unit by suction of a wet crusher, crushed to about 5 to 20 mm, and pumped to the next step at 0.03 m 3 /min.
• at least part of each layer constituting the laminated film is likely to be separated into single layers due to the high shear received when the film is crushed.
• the laminated film is provided with an ink layer, the ink layer is also easily peeled off and removed from the film by high shear caused by crushing, and it is preferable that at least a part of the ink layer is peeled off.
• the laminate When the laminate is pulverized into powder using a grinder as a wet crusher, it is preferable to use a laminate film roll that has been cut into small pieces of about 5 mm square.
• the laminate crushed by the grinder is pulverized to about 10 to 500 ⁇ m.
• the number of crushing steps in step 1 may be performed once or in several steps. For example, when multiple wet crushing steps are performed in step 1, each washing liquid may be changed. Further, between these steps or after step 1, known steps such as water washing, draining, dehydration, and drying may be added as appropriate.
• step 2 Step of agitating crushed plastics in cleaning liquid (step 2)
• the crushed plastic material crushed in step 1 is stirred in a release agent using a known stirring device such as a homodisper or a wet crusher similar to step 1, thereby making the laminate into a single layer.
• a stirring device such as a homodisper or a wet crusher similar to step 1, thereby making the laminate into a single layer.
• the ink layer is peeled off from the plastic film if it has an ink layer.
• the liquid temperature and stirring time when stirring in the release agent are not particularly limited, and can be appropriately adjusted according to various conditions such as the material of the cleaning liquid used and the structure of the laminate.
• the number of stirring steps in the release agent in step 2 may be performed once or in several steps. For example, when step 2 is performed multiple times, each release agent may be changed. Further, between these steps or after step 2, known steps such as water washing, draining, dehydration, and drying may be added as appropriate.
• step 3 Recovery step of crushed mixture of separated monolayers
• the water or cleaning liquid in step 1 and the release agent in step 2 contain the separated single-layer film of each layer, an adhesive and a printing. Residues such as ink and metal foil are floating or dissolved. After these are removed from the washing liquid, they are separated and collected.
• plastics with a light specific gravity such as polyolefins such as polypropylene and polyethylene (floating matter), polyesters with a higher specific gravity than polyolefins, condensation synthetic films such as nylon, or metal Heavy objects such as foils are sorted out, and the heavy objects are removed.
• plastics with a light specific gravity such as polyolefins such as polypropylene and polyethylene (floating matter), polyesters with a higher specific gravity than polyolefins, condensation synthetic films such as nylon, or metal Heavy objects such as foils are sorted out, and the heavy objects are removed.
• the plastic collected in the washing and dehydrating process is washed and dehydrated, and the plastics with different specific gravities are separated by centrifugal separation.
• separated plastics containing vinyl chloride resin, polyethylene terephthalate, etc., having a specific gravity of 1 or more that sink in water, and separated plastics containing olefinic resins such as polyethylene and polypropylene, which do not contain vinyl chloride resin, can be separated. Further fractionation is possible by changing the specific gravity by appropriately changing the blending ratio of the liquid used in the floating fractionation, such as water and the organic solvent or salt.
• advanced sorting may be performed using electrostatic separation that utilizes the inherent charging characteristics of plastics.
• An example of a specific method is to separate a pre-charged plastic mixture by dropping it between parallel plate electrodes to which a voltage is applied.
• a combination of plastics with a small specific gravity difference, which is difficult to separate by specific gravity separation, can also be separated.
• step 4 Recovery and reuse of washing solution (step 4)
• the water, washing liquid, or stripping agent used in steps 1 and 2 are supplied to any one or more recycling machines selected from a filter, a centrifuge, and an ultrafiltration machine to recover the solids. Reused after removal. While the wet crushing step and the gravity separation step are performed in steps 1 and 2, the water, washing liquid or stripping agent recycling step may be operated continuously to separate the solid matter from the water, washing liquid or stripping agent. can.
• step 5 Drying of plastic separation (step 5)
• the laminate separated and recovered in step 3 is dried by any one or more methods selected from reduced pressure heat drying, hot air drying, and pressure compression drying to remove residual moisture.
• pressurization such as a pellet mill (manufactured by Miike Iron Works) or Stella (manufactured by Elcom Co., Ltd., briquette machine) is performed after or during drying of the collected film pieces.
• the briquette may be produced by using a compactor.
• the pressure compression step can be omitted.
• the density varies depending on the material that constitutes the pulverized product, but the higher the density, the easier it is to handle in the kneader, so it is preferable.Specifically, It is preferably 0.03 kg or more, more preferably 0.05 kg or more, more preferably 0.2 kg or more, and even more preferably 0.3 kg or more in a dry state.
• step 6 Production of recycled pellets (step 6)
• the film pieces or briquettes dried in step 5 are fed into single-screw and twin-screw molding machines to produce recycled pellets.
• the kneader conditions are not particularly limited, but it is preferable to operate at 180 to 280° C. so as not to greatly deteriorate the resin performance before recycling.
• OPP Biaxially oriented polypropylene film 20um
• VMCPP aluminum deposition unstretched polypropylene film 25um
• CPP unstretched polypropylene film 35um (printing ink)
• INK1 Finart R507 primary color indigo (manufactured by DIC Graphics Co., Ltd.)
• INK2 Two-liquid curable ink (reactive adhesive) consisting of Finart R794 White G3 (manufactured by DIC Graphics Co., Ltd.) and curing agent CVL Hardener #10 (manufactured by DIC Co., Ltd.)
• AD1 solvent-based adhesive Dick Dry LX-470EL and SP-60 two-component adhesive (ether-based adhesive) (manufactured by DIC Corporation)
• AD2 Solvent-free adhesive Dick Dry 2K-SF-400A and HA-400B two-component adhesive (ester adhesive) (manufactured by DIC Corporation) (Method for manufacturing laminate
• Test specimens were obtained by cutting the laminated films "LAM1" and “LAM2" into a size of 2 cm x 6 cm.
• Step 1 PRO11: A colloid mill WCM manufactured by Iwaki was used and stirred at 20000 rpm for 10 minutes.
• PRO12 Sancutta C125H manufactured by Nikuni was used and pumped at 0.1 m3/min.
• PRO13 Using Homo Disper, the mixture was stirred at 200 rpm for 10 minutes while maintaining the liquid temperature at 70°C.
• PRO14 Using a masscolloider manufactured by Masuko Sangyo Co., Ltd., pulverize at 1500 rpm until the pulverization size reaches about 100 ⁇ m.
• Table 2 shows the materials blended as the cleaning solution in step 1. 2% by weight of sodium hydroxide is indicated as ⁇ in Table 2 when it is added. M2-100R (cationic surfactant, NOF CORPORATION) is indicated as ⁇ in Table 4 when 0.3% by weight is blended. When it was not blended, "-" was described. In the detergent composition of Table 2, water was added to make up for the shortfall of 100% by weight when added in the vertical direction.
• Step 2 PRO21: Using Homo Disper, the mixture was stirred at 200 rpm for 10 minutes while maintaining the liquid temperature at 70°C.
• PRO22 Using Sancutta C125H manufactured by Nikuni, the liquid was stirred while being pumped at 0.1 m3/min while maintaining the liquid temperature at 70°C.
• Water and 2% by weight of potassium hydroxide are indicated as ⁇ in Table 5 when they are mixed. 0.3% by weight of the surfactant is listed in Table 5 when it is used.
• the type is described in the upper row, and the blending weight % is described in the lower row. When it was not blended, "-" was described.
• the release agent composition in Table 5 was added in the vertical direction and water was added to make up for the shortfall of 100% by weight.
• Result 1 in Tables 6 to 8 shows the state of ink removal from the laminated film.

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