Recycled resin manufacturing method

Abstract

Provided is a method for producing regenerated resin from a waste resin composition that contains a synthetic resin and organic impurities.　A method for producing regenerated resin from a waste resin composition, the method including a step (a1) in which the waste resin composition is brought into contact with 1-30 mass% of saltwater to obtain a regenerated resin composition, and a step (b1) in which the regenerated resin composition is washed with water to obtain regenerated resin.

Description

[Technical Field]

[0001] The present invention relates to a method for producing recycled resin. [Background technology]

[0002] In recent years, concerns have grown over the deterioration of the natural environment and the increase in waste emissions, and there has been an increasing movement to reuse and recycle plastic products in an effort to realize a recycling-oriented society.

[0003] Synthetic resins such as polycarbonate resin and polyester resin, which are the main components of plastic products, are widely used in a variety of applications, including home appliances, electronic and electrical equipment, office automation equipment, optical media, automotive parts, and building materials. Large amounts of synthetic resin waste are generated during the manufacture of the above plastic products and after their use, and these waste materials are therefore being recycled.

[0004] In particular, when plastic products are manufactured by molding synthetic resins, the parts originating from the passages of the mold, such as sprues, runners, and gates, are removed to produce the plastic products. Efforts are being made to recycle and reuse waste resins, such as synthetic resins that are not needed for such plastic products and are removed, as well as other waste resins such as defective moldings, without discarding them.

[0005] For example, Patent Document 1 describes an invention relating to a method for recovering polycarbonate resin, which includes a step of crushing discarded optical discs and / or recovered optical discs having a polycarbonate resin substrate and chemically treating the resulting crushed material. The recovery method describes a step of removing magnetic metallic foreign matter from the chemically treated material obtained in the chemical treatment step using a magnet, removing colored foreign matter using an optical camera, and removing resin containing metallic foreign matter using a metallic foreign matter detector. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-131507 Summary of the Invention [Problem to be solved by the invention]

[0007] The recovery method described in Patent Document 1 allows for the recovery of synthetic resins by removing metals, colored foreign matter, resins containing metal foreign matter, etc. The recovery method is carried out based on the appearance of contained metals and coloration. However, plastic products are often manufactured by combining multiple types of synthetic resins, and synthetic resins that are not needed for plastic products and are removed, such as defective molded products, contain organic impurities along with the desired synthetic resin. In such cases, the presence or absence of metals and the degree of coloration may not differ significantly between the desired synthetic resin and the organic impurities. As a result, the method described in Patent Document 1 is unable to recover and recycle the desired synthetic resin. Under these circumstances, a new method for producing recycled resin from a waste resin composition is needed.

[0008] Therefore, an object of the present invention is to provide a method for producing recycled resin from a waste resin composition containing synthetic resin and organic impurities. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved by using a method that focuses on the properties of recycled resin, which has led to the completion of the present invention.

[0010] That is, the present invention includes the following aspects. [1] A method for producing recycled resin from a waste resin composition, a step (a1) of contacting the waste resin composition with 1 to 30 mass% salt water to obtain a recycled resin composition; a step (b1) of washing the recycled resin composition with water to obtain a recycled resin; A manufacturing method comprising: [2] The method of producing the product according to [1] above, further comprising, after the step (b1), a step (c1) of measuring the conductivity of the water after washing. [3] The method according to [1] or [2] above, wherein the difference (K2-K1) between the water conductivity before washing (K1) and the water conductivity after washing (K2) is less than 100 μS / cm. [4] The method according to any one of the above [1] to [3], wherein the longest diameter of the waste resin composition is 5 cm or less. [5] A method for producing a recycled resin from a waste resin composition, a step (a2) of contacting activated carbon with the waste resin solution in which the waste resin composition is dissolved to obtain a regenerated resin solution; a step (b2) of contacting the regenerated resin solution with water at 40 to 100°C to precipitate the regenerated resin; A manufacturing method comprising: [6] The method according to the above [5], wherein the waste resin solution is a 5 to 20 mass % methylene chloride solution. [7] The method according to the above [5] or [6], wherein the amount of the activated carbon used is 0.001 to 0.1 parts by mass per 100 parts by mass of the waste resin solution. [8] The method according to any one of the above [5] to [7], wherein the amount of water used is 1,000 to 10,000 parts by mass per 100 parts by mass of the waste resin solution. [9] The method according to any one of [5] to [8] above, wherein the step (b2) comprises adding the regenerated resin solution to water at 40 to 100°C that is stirred by a stirrer having a stirring blade.

[10] The method according to any one of the above [5] to [9], further comprising, after the step (b2), a step (c2) of dehydrating the recycled resin.

[11] A method for producing a recycled resin from a waste resin composition, The method includes a step (a3) ​​of subjecting the slurry containing the waste resin composition and water to hydrocyclone treatment to separate the recycled resin.

[12] The waste resin composition contains a cycloolefin polymer, The production method according to

[11] above, wherein the content of the cycloolefin polymer is 20 mass % or less based on the total mass of the waste resin composition.

[13] The production method according to the above

[11] or

[12] , wherein the content of the waste resin composition is 1 to 10 mass % based on the total mass of the slurry.

[14] The method according to any one of the above

[11] to

[13] , wherein the amount of water used is 1,000 to 10,000 parts by mass per 100 parts by mass of the waste resin composition.

[15] The method according to any one of the above

[11] to

[14] , wherein the flow rate of the hydrocyclone treatment is 500 to 800 L / min.

[16] The hydrocyclone treatment is performed by a cyclone separator having an upper cylindrical portion with a first discharge mechanism and an inverted cone portion with a second discharge mechanism; The method according to any one of the above

[11] to

[15] , wherein the inverted cone portion has a cone angle of 10 to 35 degrees.

[17] The hydrocyclone treatment is performed by a cyclone separator having an upper cylindrical portion with a first discharge mechanism and an inverted cone portion with a second discharge mechanism; The manufacturing method according to any one of the above

[11] to

[16] , wherein the orifice diameter of the second discharge mechanism is 10 to 50 mm.

[18] The method according to any one of the above

[11] to

[17] , further comprising, after the step (a3), a step (b3) of dehydrating the recycled resin.

[19] The method according to any one of the above

[11] to

[18] , wherein the mass of the recycled resin is 80 mass % or more relative to the mass of the waste resin composition.

[20] The recycled resin is represented by the following general formulas (1) to (5): [ka] [During the ceremony, X a , X b , X c , X d , X e , and X f each independently represents an alkylene group having 1 to 4 carbon atoms, R a , R b , R c , R d , R e , and R f each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and -C≡CR i is selected from R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S, a, b, c, d, e, and f each independently represent an integer of 0 to 10; h, i, j, k, m, and n each independently represent an integer of 0 to 4; R g and R h each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method according to any one of the above [1] to

[19] , wherein the resin has at least one structural unit selected from the group consisting of:

[21] The waste resin composition is a compound represented by the following general formulas (6) to (8): [ka] [During the ceremony, X g each independently represents an alkylene group having 1 to 10 carbon atoms, R j , R k , and R leach independently represents a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and -C≡CR i is selected from R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S, Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3, where q is 2 or more and two R j If two R are on adjacent carbon atoms, j may be taken together to form a ring structure, r is 2 or more, and two R k If two R are on adjacent carbon atoms, k may be taken together to form a ring structure, s is 2 or more and two R l If two R are on adjacent carbon atoms, l may be taken together to form a ring structure, R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method for producing a polymerizable compound according to any one of the above [1] to

[20] , comprising an impurity resin having at least one structural unit selected from the group consisting of:

[22] A method for producing a recycled resin from a waste resin composition, comprising: The following general formulas (1) to (4): [ka] [During the ceremony, Xa , X b , X c , X d , X e , and X f each independently represents an alkylene group having 1 to 4 carbon atoms, R a , R b , R c , R d , R e , and R f each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and -C≡CR i is selected from R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S, a, b, c, d, e, and f each independently represent an integer of 0 to 10; h, i, j, k, m, and n each independently represent an integer of 0 to 4; R g each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. A waste resin composition containing a resin having at least one structural unit selected from the group consisting of: [ka] (a4) obtaining at least one dihydroxy compound selected from the group consisting of:

[23] The production method according to

[22] above, further comprising, after the step (a4), a step (b4) of obtaining a recycled resin containing at least one structural unit selected from the group consisting of the general formulae (1) to (4) from the dihydroxy compound. [Effects of the Invention]

[0011] According to the present invention, a recycled resin can be produced from a waste resin composition containing a synthetic resin and organic impurities. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram schematically illustrating a first embodiment. [Figure 2] FIG. 10 is a schematic diagram of a cyclone separator used in the third embodiment. [Figure 3] FIG. 10 is a diagram showing the mechanism of hydrocyclone treatment when a cyclone separator used in the third embodiment is used. DETAILED DESCRIPTION OF THE INVENTION

[0013] According to the present invention, there is provided a method for producing recycled resin from a waste resin composition, which includes four specific embodiments.

[0014] The first, second, and third embodiments produce recycled resin by utilizing the difference in physical properties between the desired synthetic resin and organic impurities contained in the waste resin composition. When producing recycled resin from the waste resin composition, the chemical structure of the recycled resin remains unchanged or remains almost unchanged throughout the production process. That is, the first to third embodiments produce recycled resin by removing organic impurities contained in the waste resin composition.

[0015] On the other hand, in the fourth embodiment, recycled resin is produced by utilizing the difference in chemical properties between the desired synthetic resin and organic impurities contained in the waste resin composition. When recycled resin is produced from the waste resin composition, the chemical structure of the recycled resin changes during the production process. Specifically, the desired synthetic resin contained in the waste resin is at least partially depolymerized and then converted into recycled resin.

[0016] Each embodiment will be described in detail below.

[0017] First Embodiment The first embodiment relates to a method for producing a recycled resin from a waste resin composition, which includes step (a1) of contacting the waste resin composition with 1 to 30% by mass of salt water to obtain a recycled resin composition, and step (b1) of washing the recycled resin composition with water to obtain a recycled resin. The method may further include a step of preparing a waste resin composition before step (a1). Furthermore, the method may further include a step (c1) of measuring the conductivity of the water after washing after step (b1). In one embodiment, the first embodiment includes, in this order, a step of preparing a waste resin composition, step (a1), step (b1), and step (c1). This embodiment allows for the production of a recycled resin that contains no or almost no organic impurities. As a result, the resulting recycled resin has low haze.

[0018] Fig. 1 is a diagram showing a schematic diagram of a first embodiment. According to Fig. 1, a waste resin composition raw material 11 is introduced into a pulverizer 21, and the waste resin composition raw material 11 is pulverized to obtain a waste resin composition 12 (a process for preparing a waste resin composition). This process makes it possible to adjust the size of the waste resin composition 12, for example, and to efficiently remove organic impurities in subsequent processes.

[0019] Next, the obtained waste resin composition 12 is fed into a feeder 22 and then into a saltwater tank 24 through a transport path 23. At this time, 1 to 30 mass % of saltwater is stored in the saltwater tank 24. The rotation of three agitators 25 provided in the saltwater tank 24 promotes contact between the waste resin composition 12 and the saltwater. In this embodiment, the recycled resin settles in the saltwater, and organic impurities float. Therefore, first, a recovery device (not shown) is used from the top of the saltwater tank 24 to recover the organic impurities floating on the surface of the saltwater and remove them from the saltwater tank 24. Next, the recycled resin composition is obtained from a discharge outlet 26 provided at the bottom of the saltwater tank 24 (step (a1)). At this time, most of the saltwater is removed by filtration.

[0020] The obtained recycled resin composition usually contains recycled resin and salt water. Therefore, the recycled resin composition is introduced into a water washing tank 27 and washed with water (before washing) 13 to obtain a recycled resin (step (b1)). In this case, it is preferable to repeat the water washing until the salt can be removed from the recycled resin.

[0021] After step (b1), the conductivity of the water (after washing) 14 is measured (step (c1)). This makes it possible to determine whether salt remains in the recycled resin, and can be used for quality control of the recycled resin. Preferably, the conductivity of the water (before washing) 13 is compared with the conductivity of the water (after washing) 14. The closer the difference is to 0, the less salt remains in the recycled resin, i.e., the higher the quality of the recycled resin can be determined to be. On the other hand, if the difference between the conductivity of the water (before washing) 13 and the conductivity of the water (after washing) 14 is large (the conductivity of the water (after washing) 14 is higher), it can be determined that salt that should be washed out remains in the recycled resin, and therefore it is preferable to perform step (b1) again.

[0022] The obtained recycled resin is introduced into a dehydrator 29 through a transport path 28. The dehydrator can remove the water content from the recycled resin. This allows recycled resin 15 to be produced.

[0023] In this way, by utilizing the difference in physical properties between the desired synthetic resin (recycled resin) and the organic impurities, recycled resin can be produced from a waste resin composition containing the desired synthetic resin (recycled resin) and the organic impurities. Each step will be described below.

[0024] [Step of preparing waste resin composition] The first embodiment may include a step of preparing a waste resin composition, which is usually carried out before the step (a1).

[0025] In one embodiment, the step of preparing the waste resin composition includes pulverizing a waste resin composition raw material to prepare the waste resin composition. Also, in one embodiment, the step of preparing the waste resin composition includes removing metals from the waste resin composition raw material. The step of preparing the waste resin composition may include both the pulverization and the metal removal. In this case, the order of pulverization and metal removal is not particularly limited, but it is preferable to perform the metal removal after pulverization because this allows for efficient metal removal.

[0026] (Waste resin composition raw material) The waste resin composition raw material is not particularly limited, but examples include molded products recovered after being used in the market as part of a product, defective products generated during the molding process, molded products (sprue, runner, gate, etc.) incidental to the molding process, defective products generated during the commercialization process, and unused molded products that are no longer needed. Among these, from the viewpoint of minimizing deterioration of the desired synthetic resin, those derived from defective products generated during the molding process, molded products (sprue, runner, gate, etc.) incidental to the molding process, defective products generated during the commercialization process, and unused molded products that are no longer needed are preferred. From the viewpoint of procurement efficiency, those derived from defective products generated during the molding process and molded products (sprue, runner, gate, etc.) incidental to the molding process are more preferred. The above-mentioned molded products and the like may be sorted, and only those containing organic impurities may be used as the waste resin composition raw material. For example, sprues may be sorted, and those that can be recycled as they are removed and used in products, while the remaining ones containing organic impurities may be used as the waste resin composition raw material. Furthermore, waste resin composition raw materials may be made by mixing materials of different origins.

[0027] The form of the waste resin composition raw material is not particularly limited, and examples thereof include powder, pellets, sheets, films, molded products, and the like, as well as discarded lenses, sheets, and films; defective products and burrs generated during manufacturing and / or molding processing; manufacturing waste; solids recovered from waste products using resin, and pulverized products thereof.

[0028] The longest diameter of the waste resin composition raw material is preferably 100 cm or less, more preferably 50 cm or less, and even more preferably 0.5 to 3 cm. If the longest diameter of the waste resin composition raw material is 100 cm or less, it is preferable because the energy required for pulverization is low. In this specification, the "longest diameter" means the average value of the diameter with the longest distance along the outline of 200 randomly selected objects.

[0029] (Crushing) The pulverization method is not particularly limited, and any of compression, impact, shear, and friction methods may be used.

[0030] Examples of crushers that can be used include coarse crushers such as jaw crushers, gyratory crushers, impact crushers, single-axis crushers, and twin-axis crushers; medium crushers such as roll crushers, edge runners, disintegrators, SAG (Semi-Autogenous Grinding) mills, crushing rolls, hammer mills, and roller mills; and fine crushers such as bead mills, ball mills, vibration ball mills, rod mills, jet mills, and planetary mills. Among these, coarse crushers are preferred, and single-axis crushers and twin-axis crushers are more preferred. Specific examples of crushers include high-power crushers 35-560, 35-720, 55-770, and 55-1050 (manufactured by Tanaka Corporation), and low-speed crushers KGA-250 and KGA-350 (manufactured by Kawata Corporation). The above-mentioned crushers may be used alone or in combination of two or more.

[0031] (metal removal) The method for removing metals is not particularly limited, and examples thereof include a method using magnetic force, a method using wind power, a method using a sieve, a method using specific gravity, a method using buoyancy, etc. Of these, a method using magnetic force (a method using a magnet, a method using a metal detector, etc.), a method using specific gravity, and a method using buoyancy (a method using salt water) are preferred. These methods may be used alone or in combination of two or more.

[0032] The metals to be removed include metals contained in plastic products, metals mixed in during the molding process, metals mixed in during the crushing process, and the like.

[0033] (Waste resin composition) The waste resin composition may be the waste resin composition raw material as it is, but is preferably one obtained by pulverizing the waste resin composition raw material, removing metals, etc. However, if pulverization or metal removal is not required for the waste resin composition raw material, it is preferable to use the waste resin composition raw material as it is as the waste resin composition. For example, if the size of the waste resin composition raw material is uniform, the longest diameter of the waste resin composition raw material is small (for example, the longest diameter is 5 cm or less), or no metal is contained, it is preferable not to perform the step of preparing the waste resin composition from the viewpoint of production costs.

[0034] The waste resin composition contains a desired synthetic resin and organic impurities. The desired synthetic resin is usually ultimately recycled as a resin. In this specification, the term "resin" refers to a resin having a weight-average molecular weight of 1,000 or more. In this specification, the term "weight-average molecular weight (Mw)" refers to the weight-average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0035] Desired synthetic resin (recycled resin) The recycled resin is not particularly limited, but examples thereof include thermoplastic resins, such as polyolefin resins (polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), and polytetrafluoroethylene (PTFE)), polyurethane (PU) resins, acrylic resins, polyester resins (polyethylene terephthalate (PET), polybutylene terephthalate (PBT)), polyamide (PA) resins, polyacetal resins, cyclic polyolefins (cycloolefin polymers), polycarbonate (PC) resins, polyester carbonate resins, polyphenylene sulfide (PPS) resins, polysulfone resins, polyethersulfone resins, liquid crystal polymers (LCPs), polyether ether ketone (PEEK) resins, and polyamide-imide (PAI) resins, as well as copolymers of the structural units of these resins (such as acrylonitrile-styrene copolymer resins (AS resins) and acrylonitrile-butylene-styrene copolymer resins (ABS resins)).

[0036] Of these, the recycled resin is preferably polyester resin, polyamide (PA) resin, polyacetal resin, cyclic polyolefin, polycarbonate (PC) resin, or polyester carbonate resin, more preferably polycarbonate (PC) resin, polyester resin, or polyester carbonate resin, and even more preferably polycarbonate (PC) resin.

[0037] The recycled resin preferably contains a resin having at least one structural unit selected from the group consisting of the following general formulas (1) to (5): The resin having the structural unit is usually a polycarbonate (PC) resin, a polyester resin, or a polyester carbonate resin, and is preferably a polycarbonate resin.

[0038] [ka]

[0039] In the above formula, Xa , X b , X c , X d , X e , and X f each independently represents an alkylene group having 1 to 4 carbon atoms. Examples of the alkylene group having 1 to 4 carbon atoms include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, and tert-butylene. Of these, methylene and ethylene are preferred, and ethylene is more preferred.

[0040] R a , R b , R c , R d , R e , and R f each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and -C≡CR i It is selected from the following: c and R d In formula (2), R is a substituent of the fluorene ring and / or a substituent of the phenyl group bonded to the fluorene ring. e and R f is a substituent of the fluorene ring and / or a substituent of the naphthyl group bonded to the fluorene ring in formula (3).

[0041] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0042] Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, and an icosyl group.

[0043] Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, and an icosyloxy group.

[0044] Examples of the cycloalkyl group having 5 to 20 carbon atoms include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclododecyl group, a cyclotridecyl group, a cyclotetradecyl group, a cyclopentadecyl group, a cyclooctadecyl group, a bicyclo[2.2.1]heptyl group, and a bicyclo[2.2.2]octyl group.

[0045] Examples of the cycloalkoxy group having 5 to 20 carbon atoms include a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, a cyclooctyloxy group, a cyclododecyloxy group, a cyclotridecyloxy group, a cyclotetradecyloxy group, a cyclopentadecyloxy group, a cyclooctadecyloxy group, a bicyclo[2.2.1]heptyloxy group, and a bicyclo[2.2.2]octyloxy group.

[0046] Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a trimethylphenyl group, a tetramethylphenyl group, an ethylphenyl group, an ethylmethylphenyl group, a diethylphenyl group, a propylphenyl group, an isopropylphenyl group, an isopropylmethylphenyl group, a benzyl group, a phenethyl group, a phenylpropyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a naphthacenyl group, a chryserinyl group, a pyrenyl group, a biphenyl group, a terphenyl group, and a quaterphenyl group.

[0047] Examples of the heteroaryl group having 3 to 20 carbon atoms and containing one or more heterocyclic atoms selected from O, N, and S include a furanyl group, a benzofuranyl group, an isobenzofuranyl group, a pyrrolyl group, an imidazolyl group, a pyrazolyl group, a triazolyl group, a pyridyl group, a pyrazyl group, a pyrimidyl group, a pyridazyl group, a pyrrolidyl group, an indolyl group, an isoindolyl group, an indazolyl group, a quinolyl group, an isoquinolyl group, a naphthyridyl group, a quinoxalyl group, a quinazolyl group, a propanol ... Examples thereof include a teridyl group, a phenanthridyl group, an acridinyl group, a pyrimidinyl group, a phenanthrolinyl group, a phenazinyl group, a thiophenyl group, a thiopyranyl group, a benzothiophenyl group, a benzothiopyranyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, a furazanyl group, an oxadiazolyl group, a dithiazolyl group, a benzoxazolyl group, a benzisoxazolyl group, a benzothiazolyl group, and a benzisothiazolyl group.

[0048] Examples of the aryloxy group having 6 to 20 carbon atoms include a phenyloxy group, a tolyloxy group, a xylyloxy group, a trimethylphenyloxy group, a tetramethylphenyloxy group, an ethylphenyloxy group, an ethylmethylphenyloxy group, a diethylphenyloxy group, a propylphenyloxy group, an isopropylphenyloxy group, an isopropylmethylphenyloxy group, a naphthyloxy group, an anthracenyloxy group, a phenanthrenyloxy group, a naphthacenyloxy group, a chryserinyloxy group, a pyrenyloxy group, a biphenyloxy group, a terphenyloxy group, and a quaterphenyloxy group.

[0049] Of these, R a , R b , R c , R d , R e , and R f is preferably a phenyl group or a naphthyl group, more preferably a phenyl group, a 1-naphthyl group or a 2-naphthyl group.

[0050] R irepresents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S. Examples of the aryl group having 6 to 20 carbon atoms and the heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S include those mentioned above. Among these, R i is preferably a phenyl group or a naphthyl group, more preferably a phenyl group, a 1-naphthyl group or a 2-naphthyl group.

[0051] a, b, c, d, e, and f each independently represent an integer of 0 to 10. In one embodiment, a, b, c, d, e, and f each independently represent preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and even more preferably an integer of 0 or 1. In another embodiment, a, b, c, d, e, and f each independently represent preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and even more preferably an integer of 1 or 2.

[0052] h, i, j, k, m, and n each independently represent an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 or 1, and particularly preferably 0.

[0053] R g and R h Each of R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, and an isopropyl group. g and R h are each preferably independently a hydrogen atom.

[0054] Specific examples of the constitutional unit represented by formula (1) include constitutional units derived from 2,2'-bis(1-hydroxymethoxy)-1,1'-binaphthalene, 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (also referred to as "BHEBN"), 2,2'-bis(3-hydroxypropyloxy)-1,1'-binaphthalene, 2,2'-bis(4-hydroxybutoxy)-1,1'-binaphthalene, etc. In one embodiment, the constitutional unit represented by formula (1) is a constitutional unit derived from 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BHEBN).

[0055] Specific examples of the structural unit represented by formula (2) include structural units derived from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (also referred to as "BPEF"), 9,9-bis[4-(2-hydroxyethoxy)-3-methylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-tert-butylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-isopropylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3-cyclohexylphenyl]fluorene, and 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene (also referred to as "BPPEF"), etc. In one embodiment, the constitutional unit represented by formula (2) is a constitutional unit derived from a compound selected from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF) and 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene (BPPEF).

[0056] Specific examples of the structural unit represented by formula (3) include structural units derived from 9,9-bis(hydroxy(poly)alkoxynaphthyl)fluorenes. For example, structural units derived from a compound selected from 9,9-bis[6-(1-hydroxymethoxy)naphthalen-2-yl]fluorene (also referred to as "BNEF"), 9,9-bis[6-(2-hydroxyethoxy)naphthalen-2-yl]fluorene, 9,9-bis[6-(3-hydroxypropoxy)naphthalen-2-yl]fluorene, and 9,9-bis[6-(4-hydroxybutoxy)naphthalen-2-yl]fluorene can be mentioned. In one embodiment, the structural unit represented by formula (3) is a structural unit derived from 9,9-bis[6-(2-hydroxyethoxy)naphthalen-2-yl]fluorene (BNEF).

[0057] Specific examples of the structural unit represented by formula (4) include structural units derived from decahydro-1,4:5,8-dimethanonaphthalene diols (also referred to as "D-NDM"). For example, structural units derived from compounds selected from (decahydro-1,4:5,8-dimethanonaphthalene-2,6-diyl)dimethanol, (decahydro-1,4:5,8-dimethanonaphthalene-2,7-diyl)dimethanol, (2-methyldecahydro-1,4:5,8-dimethanonaphthalene-2,6-diyl)dimethanol, (2-methyldecahydro-1,4:5,8-dimethanonaphthalene-2,7-diyl)dimethanol, (2-ethyldecahydro-1,4:5,8-dimethanonaphthalene-2,6-diyl)dimethanol, and (2-ethyldecahydro-1,4:5,8-dimethanonaphthalene-2,7-diyl)dimethanol.

[0058] Specific examples of the constitutional unit represented by formula (5) include constitutional units derived from decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-6(7)-methanols. Examples include structural units derived from a compound selected from decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-6-methanol, decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-7-methanol, 2-methyl-decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-6-methanol, 2-methyl-decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-7-methanol, 2-ethyl-decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-6-methanol, and 2-ethyl-decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-7-methanol.

[0059] The above-mentioned structural units may be contained alone or in combination of two or more in the recycled resin. Furthermore, the above-mentioned structural units may be combined with structural units of other polycarbonate resins or with structural units of other resins (polyolefin resins, polyester resins) and the like.

[0060] The weight-average molecular weight (Mw) of the desired synthetic resin (recycled resin) is not particularly limited, but is preferably 10,000 to 70,000, and more preferably 15,000 to 50,000. A weight-average molecular weight (Mw) of the desired synthetic resin (recycled resin) of 10,000 or more is preferred because it can maintain appropriate strength as a molded product, such as a resin for an optical lens. On the other hand, a weight-average molecular weight (Mw) of the desired synthetic resin (recycled resin) of 70,000 or less is preferred because it can maintain appropriate fluidity during resin molding and improve moldability.

[0061] The content of the desired synthetic resin (recycled resin) in the waste resin composition is preferably 80% by mass or more, more preferably 80 to 99% by mass, based on the mass of the waste resin composition. If the content of the desired synthetic resin (recycled resin) is 80% by mass or more, recycling efficiency is high, which is preferable.

[0062] organic impurities Examples of organic impurities include impurity resins and impurity compounds.

[0063] The impurity resins include the thermoplastic resins described above. That is, when the waste resin composition contains multiple thermoplastic resins, the thermoplastic resins selected as recycled resins become recycled resins, and the thermoplastic resins not selected become impurity resins to be removed.

[0064] Among these, the waste resin composition preferably contains an impurity resin having at least one structural unit selected from the group consisting of the following general formulas (6) to (8): The impurity resin having the structural unit is usually a cyclic polyolefin.

[0065] [ka]

[0066] In the above formula, X g each independently represents an alkylene group having 1 to 10 carbon atoms. Examples of the alkylene group having 1 to 10 carbon atoms include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, tert-butylene, and pentylene. Of these, methylene, ethylene, propylene, butylene, isobutylene, and sec-butylene are preferred, and methylene, ethylene, and propylene are more preferred.

[0067] R j , R k , and R leach independently represents a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and -C≡CR i The R j , R k , and R l As for the above X a , X b , X c , X d , X e , and X f The same can be mentioned.

[0068] However, R j , R k , and R l may have a substituent. The substituent is not particularly limited, but examples thereof include a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyloxy group having 5 to 10 carbon atoms, an alkyloxycarbonyl group having 2 to 10 carbon atoms, a cycloalkyloxycarbonyl group having 5 to 10 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, a cycloalkylcarbonyloxy group having 5 to 10 carbon atoms, an arylcarbonyloxy group having 7 to 15 carbon atoms, a hydroxyalkylcarbonyl group having 2 to 10 carbon atoms, a glycidyloxycarbonyl group, a hydroxy group, a carboxy group, a cyano group, and an amido group having 1 to 10 carbon atoms.

[0069] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and a pentyl group.

[0070] Examples of the cycloalkyl group having 5 to 10 carbon atoms include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a bicyclo[2.2.1]heptyl group, and a bicyclo[2.2.2]octyl group.

[0071] Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, and a pentyloxy group.

[0072] Examples of the cycloalkyloxy group having 5 to 10 carbon atoms include a cyclopentyloxy group, a cyclohexyloxy group, a bicyclo[2.2.1]heptyloxy group, and a bicyclo[2.2.2]octyloxy group.

[0073] Examples of the alkyloxycarbonyl group having 2 to 10 carbon atoms include a methyloxycarbonyl group, an ethyloxycarbonyl group, a propyloxycarbonyl group, an isopropyloxycarbonyl group, a butyloxycarbonyl group, an isobutyloxycarbonyl group, a sec-butyloxycarbonyl group, and a tert-butyloxycarbonyl group.

[0074] Examples of the cycloalkyloxycarbonyl group having 5 to 10 carbon atoms include a cyclopentyloxycarbonyl group, a cyclohexyloxycarbonyl group, a bicyclo[2.2.1]heptyloxycarbonyl group, and a bicyclo[2.2.2]octyloxycarbonyl group.

[0075] Examples of the aryloxycarbonyl group having 7 to 15 carbon atoms include a phenyloxycarbonyl group, a tolyloxycarbonyl group, a xylyloxycarbonyl group, a trimethylphenyloxycarbonyl group, a tetramethylphenyloxycarbonyl group, an ethylphenyloxycarbonyl group, an ethylmethylphenyloxycarbonyl group, a diethylphenyloxycarbonyl group, and a naphthyloxycarbonyl group.

[0076] Examples of the alkylcarbonyloxy group having 2 to 10 carbon atoms include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, and a butylcarbonyloxy group.

[0077] Examples of the cycloalkylcarbonyloxy group having 5 to 10 carbon atoms include a cyclopentylcarbonyloxy group, a cyclohexylcarbonyloxy group, a bicyclo[2.2.1]heptylcarbonyloxy group, and a bicyclo[2.2.2]octylcarbonyloxy group.

[0078] Examples of the arylcarbonyloxy group having 7 to 15 carbon atoms include a phenylcarbonyloxy group, a tolylcarbonyloxy group, a xylylcarbonyloxy group, a trimethylphenylcarbonyloxy group, a tetramethylphenylcarbonyloxy group, an ethylphenylcarbonyloxy group, an ethylmethylphenylcarbonyloxy group, a diethylphenylcarbonyloxy group, and a naphthylcarbonyloxy group.

[0079] Examples of the hydroxyalkylcarbonyl group having 2 to 10 carbon atoms include a hydroxymethylcarbonyl group, a hydroxyethylcarbonyl group, and a hydroxypropylcarbonyl group.

[0080] Examples of the amido group having 1 to 10 carbon atoms include a methylaminocarbonyl group, an ethylaminocarbonyl group, a dimethylaminocarbonyl group, and an acetylamino group.

[0081] The above-mentioned substituents may be present alone or in combination of two or more kinds.

[0082] R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S. i is the same as above.

[0083] Each p independently represents an integer of 0 or 1.

[0084] q, r, and s each independently represent an integer of 0 to 10, preferably 0 to 5, and more preferably 0 to 3.

[0085] t represents an integer of 1 to 3, and is preferably 1 or 2.

[0086] where q is 2 or more and two R j If two R are on adjacent carbon atoms, j may be joined together to form a ring structure. For example, when q is 2 and two R j When both R are substituted or unsubstituted alkyl groups, general formula (6) becomes the following formula (6-1), where q is 2 and two R j When is a substituted or unsubstituted alkyl and a substituted or unsubstituted cycloalkyl, general formula (6) can be the following formula (6-2), (6-3), or (6-4).

[0087] [ka]

[0088] In the above formula, X g and p is as described above.

[0089] R n is the above-mentioned substituent, and specific examples thereof include a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyloxy group having 5 to 10 carbon atoms, an alkyloxycarbonyl group having 2 to 10 carbon atoms, a cycloalkyloxycarbonyl group having 5 to 10 carbon atoms, an aryloxycarbonyl group having 7 to 15 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, a cycloalkylcarbonyloxy group having 5 to 10 carbon atoms, an arylcarbonyloxy group having 7 to 15 carbon atoms, a hydroxyalkylcarbonyl group having 2 to 10 carbon atoms, a glycidyloxycarbonyl group, a hydroxy group, a carboxy group, a cyano group, and an amido group having 1 to 10 carbon atoms.

[0090] Although z is not particularly limited, it is preferably 0 to 6, more preferably 0 to 3, and even more preferably 0 or 1.

[0091] u represents an integer of 1 to 3, preferably 1 or 2.

[0092] Also, if r is 2 or more, and two R k If two R are on adjacent carbon atoms, k may be joined together to form a ring structure. For example, when r is 2, two R k When both R are substituted or unsubstituted alkyl groups, the general formula (7) becomes the following formula (7-1) or (7-2), where r is 2 and the two R k When is a substituted or unsubstituted alkyl and a substituted or unsubstituted cycloalkyl, general formula (7) can be the following formula (7-3).

[0093] [ka]

[0094] In the above formula, X g ,p,R n , z, and u are as described above.

[0095] Furthermore, if s is 2 or more and two R l If two R are on adjacent carbon atoms, l may be joined together to form a ring structure. For example, when s is 2 and two R l are both substituted or unsubstituted alkyl groups, the general formula (8) becomes the following formula (8-1) or (8-2), where s is 2 and two R l When is a substituted or unsubstituted alkyl and a substituted or unsubstituted cycloalkyl, general formula (8) can be the following formula (8-3) or (8-4).

[0096] [ka]

[0097] In the above formula, X g ,p,R n , z, and u are as described above.

[0098] R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms is not particularly limited, but examples thereof include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

[0099] Specific examples of impurity resins include those containing at least one selected from the group consisting of structural units represented by the following formulas 1 to 8.

[0100] [ka]

[0101] The above-mentioned structural units may be contained alone or in combination of two or more in the impurity resin. In addition, the above-mentioned structural units may be combined with structural units of other cyclic polyolefins, or with structural units of other resins (polyolefin resins, polyester resins), etc.

[0102] The weight-average molecular weight (Mw) of the impurity resin is not particularly limited, but is preferably 1,000 to 3,000,000, more preferably 10,000 to 3,000,000, even more preferably 20,000 to 1,000,000, and particularly preferably 30,000 to 500,000. A weight-average molecular weight (Mw) of the impurity resin of 1,000 or more is preferred because separation is easier. On the other hand, a weight-average molecular weight (Mw) of the impurity resin of 3,000,000 or less is preferred because trace amounts of the impurity resin are less likely to become a source of gel impurities when they contaminate the recycled resin.

[0103] The content of impurity resins in the waste resin composition is preferably 50% by mass or less, more preferably 0.001 to 50% by mass, even more preferably 0.01 to 0% by mass, and particularly preferably 0.1 to 20% by mass, based on the total mass of the waste resin composition. If the content of impurity resins is 50% by mass or less, efficiency is increased, which is preferable.

[0104] The impurity compounds are not particularly limited, but include monomers, dimers, copolymers, and oligomers of the above-mentioned impurity resins, aryl alcohols such as phenol, carbonate diesters such as diphenyl carbonate, modified products of recycled resin raw material monomers such as those represented by the following formulas (A-1) and (A-2), and modified recycled resins having partial structures represented by the following formulas (B-1) and (B-2).In this specification, "impurity compounds" refers to organic compound impurities having a weight-average molecular weight of less than 1000.For this reason, if the weight-average molecular weight of the modified recycled resin is 1000 or more, the modified recycled resin will be classified as an impurity resin. [ka]

[0105] In the above formula (B-1) and formula (B-2), "*" indicates the bonding site to the polymer chain.

[0106] Combination of desired synthetic resin (recycled resin) and impurity resin As described above, thermoplastic resins selected as recycled resins are considered recycled resins, while those not selected as recycled resins are considered to be removed impurity resins. Among these, from the viewpoints of economy, compatibility, separability, etc., recycled resins preferably contain polycarbonate resins, and more preferably contain resins having at least one structural unit selected from the group consisting of general formulas (1) to (5). Meanwhile, impurity resins preferably contain cyclic polyolefins (cycloolefin polymers), more preferably contain resins having at least one structural unit selected from the group consisting of general formulas (6) to (8), and even more preferably contain resins having at least one structural unit selected from the group consisting of formulas (6-1) to (6-4), (7-1) to (7-3), and (8-1) to (8-4). Note that polycarbonate resins typically have a relatively high specific gravity, while cyclic polyolefins (cycloolefin polymers) tend to have a relatively low specific gravity.

[0107] From the viewpoint of work efficiency, it is preferable to regard the resin selected as the recycled resin as the desired synthetic resin (recycled resin), and to regard resins other than the recycled resin as impurity resins, impurity compounds, and the like.

[0108] In the first embodiment, the greater the difference in specific gravity between the desired synthetic resin (recycled resin) and the organic impurities, the more effectively the organic impurities can be removed. The difference in specific gravity between the desired synthetic resin (recycled resin) and the organic impurities is preferably 0.05 or more, and more preferably 0.1 or more. In this case, it is preferable that the specific gravity of the desired synthetic resin (recycled resin) is greater than the specific gravity of the organic impurities. This allows the saltwater-recycled resin to settle in the saltwater and the organic impurities to float in the water in step (1), improving work efficiency. In this specification, "specific gravity" refers to the mass ratio to the same volume of water (pure water) at 1 atmosphere and 4°C.

[0109] The specific gravity of the desired synthetic resin (recycled resin) is preferably 1.02 or more, more preferably 1.05 or more, even more preferably 1.1-10, and particularly preferably 1.2-5.

[0110] The specific gravity of the organic impurities is preferably 2 or less, more preferably 1.5 or less, further preferably 0.3 to 1.3, and particularly preferably 0.5 to 1.1.

[0111] Shape of waste resin composition The shape of the waste resin composition is not particularly limited, and examples thereof include powder, granules, rods, and the like.

[0112] The longest diameter of the waste resin composition is preferably 5 cm or less, more preferably 3 cm or less, even more preferably 0.001 to 3 cm, particularly preferably 0.01 to 2 cm, and extremely preferably 0.1 to 1 cm. A longest diameter of the waste resin composition of 5 cm or less is preferable from the viewpoints of ease of transportation, ease of feeding into machines, etc.

[0113] [Process (a1)] The step (a1) is a step of contacting the waste resin composition with 1 to 30 mass % salt water to obtain a recycled resin composition.

[0114] (Waste resin composition) As the waste resin composition, a raw material for the waste resin composition may be used as it is, but it is preferable to use a waste resin composition obtained through a process for preparing a waste resin composition.

[0115] The waste resin composition contains a desired synthetic resin and organic impurities, the desired synthetic resin and the organic impurities being as described above.

[0116] (brine) The saltwater contains water and salt (sodium chloride), and may further contain other ionic components.

[0117] The concentration of the brine (salt concentration) is not particularly limited, but is preferably 1 to 26% by mass, more preferably 1 to 21% by mass, even more preferably 5 to 21% by mass, particularly preferably 8 to 21% by mass, and most preferably 12 to 21% by mass. A brine concentration of 1% by mass or more is preferred because it allows the desired synthetic resin to be separated from organic impurities. On the other hand, a brine concentration of 26% by mass or less is preferred because it reduces the haze and yellowness of the recycled resin.

[0118] The specific gravity of the brine is not particularly limited, but is preferably 1.01 to 1.20, more preferably 1.01 to 1.16, even more preferably 1.03 to 1.16, particularly preferably 1.06 to 1.16, and most preferably 1.09 to 1.16. A specific gravity of 1.01 or higher is preferred because it allows the desired synthetic resin to be separated from organic impurities. On the other hand, a specific gravity of 1.20 or lower is preferred because it reduces the haze and yellowness of the recycled resin.

[0119] The amount of brine used is not particularly limited, but is preferably 0.1 to 2.0 L, and more preferably 0.2 to 1.0 L, per 100 g of waste resin composition. Using an amount of brine of 0.1 L or more is preferred because the waste resin composition can be suitably contacted with the brine. On the other hand, using an amount of brine of 2.0 L or less is preferred because production costs can be reduced. When the recycled resin production method is carried out continuously, the brine may be recycled. In this case, it is preferred that the amount of recycled brine used, or the total amount of recycled brine and newly used brine, per 100 g of newly treated waste resin composition be within the above range.

[0120] (contact) The contact of the waste resin composition with the salt water is usually carried out by mixing the two. At this time, it is preferable to promote the contact. The method for promoting the contact is not particularly limited, and examples thereof include stirring, shaking, etc.

[0121] The contact time is not particularly limited, but is preferably 1 minute to 10 hours, more preferably 3 minutes to 3 hours, and even more preferably 5 to 60 minutes.

[0122] After contact, the desired synthetic resin and the organic impurities are separated by leaving the mixture to stand. Specifically, one of the desired synthetic resin and the organic impurities settles and the other floats due to the difference in their specific gravities. For example, if the desired synthetic resin is a polycarbonate resin and the organic impurities are cyclic polyolefins, the polycarbonate resin settles and the cyclic polyolefins float.

[0123] After standing, the separated desired synthetic resin (recycled resin) can be recovered by filtration, suction, or the like to obtain a recycled resin composition. In this case, it is preferable to remove as much saltwater as possible when recovering the recycled resin. For example, recovery by filtration can reduce the amount of saltwater contained in the recycled resin composition.

[0124] After recovery, impurities contained in the recycled resin composition can be reduced by carrying out purification steps such as dehydration and solvent extraction.

[0125] (Recycled resin composition) The recycled resin composition thus obtained contains recycled resin and salt, and may also contain water, other impurities, etc.

[0126] [Process (b1)] Step (b1) is a step of washing the recycled resin composition with water to obtain a recycled resin. Step (b1) can remove salts contained in the recycled resin composition. This allows for the production of a recycled resin with low haze.

[0127] (Recycled resin composition) The recycled resin composition is obtained in step (a1).

[0128] (water) The water is not particularly limited and may be any of pure water, tap water, groundwater, etc. The water may contain inorganic salts. Among these, pure water is preferably used from the viewpoint of improving the quality of the recycled resin. These waters may be used alone or in combination of two or more.

[0129] The amount of water used per wash is not particularly limited, but is preferably 0.1 to 2.0 L, and more preferably 0.2 to 1.0 L, per 100 g of recycled resin composition. Using 0.1 L or more of water is preferred because salts can be sufficiently removed from the recycled resin composition. On the other hand, using 2.0 L or less of water is preferred because it reduces production costs and allows the scale of the equipment to be reduced.

[0130] The total amount of water used is not particularly limited, but is preferably 0.1 to 10 L, and more preferably 0.1 to 5.0 L, per 100 g of recycled resin composition. A total amount of water of 0.1 L or more is preferred because salts can be sufficiently removed from the recycled resin composition. On the other hand, a total amount of water of 10 L or less is preferred from the viewpoints of reducing production costs and reducing the scale of the equipment. When the recycled resin production method is carried out continuously, the water used after washing may be recycled. In this case, it is preferred that the amount of recycled water used, or the total amount of recycled water and newly used water, per 100 g of newly treated recycled resin composition be within the above range.

[0131] (Washing) The washing method is not particularly limited, and the recycled resin composition may be immersed in water and stirred, or water may be sprayed onto the recycled resin composition, or a combination thereof may be used.

[0132] The washing may be repeated. Repeated washing can increase the washing efficiency. The necessity of repeated washing is preferably determined based on the measurement results of the water conductivity in step (c1) described below.

[0133] Since the recycled resin obtained by washing may contain water, it is preferable to carry out a dehydration treatment, such as drying (standing at room temperature, blowing air).

[0134] (recycled resin) As described above, in this embodiment, recycled resin is produced by utilizing the differences in physical properties of the desired synthetic resin contained in the waste resin composition. Therefore, the chemical structure of the recycled resin remains unchanged or remains almost unchanged throughout the production process. Therefore, the resulting recycled resin can be suitably used in plastic products as is.

[0135] The haze of the recycled resin is preferably 1.1 or less, more preferably 1.0 or less, even more preferably 0.85 or less, and particularly preferably 0.01 to 0.85. When the haze of the recycled resin is 1.1 or less, the recycled resin can be suitably used for plastic products. In this specification, the "haze" value means a value measured by the method in the examples.

[0136] The yellowness index YI of the recycled resin is preferably less than 13, more preferably 12 or less, even more preferably 10 or less, particularly preferably 7.7 or less, and most preferably 7.5 or less. The preferred lower limit of the yellowness index YI is not particularly limited, but is usually 0.01 or more.

[0137] [Process (c1)] Step (c1) is a step of measuring the conductivity of the water after washing. By measuring the conductivity of the water after washing, the quality of the recycled resin can be controlled.

[0138] Specifically, if the conductivity of the water is higher before and after washing, it can be determined that salt remains in the recycled resin. As a result, in some cases, the haze may be high and the recycled resin may not meet the quality requirements. In such cases, it is preferable to perform the above-mentioned step (b2) again.

[0139] On the other hand, if the conductivity of the water remains the same or almost the same before and after washing, it can be determined that the recycled resin does not contain any salts that can be removed by washing with water. As a result, the haze is low and the recycled resin meets the quality requirements.

[0140] When using water that does not contain inorganic salts (minerals), such as pure water, as cleaning water, the conductivity of the water before cleaning is 0. In this case, the conductivity of the water after cleaning is the same as the increase in conductivity due to cleaning, so quality can be controlled from the value of the conductivity of the water after cleaning.

[0141] Furthermore, when water containing inorganic salts (minerals), such as groundwater, is used as cleaning water, the conductivity of the water before cleaning is a constant value. In this case, it is preferable to calculate the increase in conductivity by comparing the conductivity of the water before cleaning with the conductivity of the water after cleaning. Specifically, it is preferable to calculate the difference (K2-K1) between the water conductivity before cleaning (K1) and the water conductivity after cleaning (K2).

[0142] The difference in water conductivity before and after washing is preferably less than 100 μS / cm, more preferably 50 μS / cm or less, even more preferably 30 μS / cm or less, particularly preferably 10 μS / cm or less, and most preferably 5 μS / cm or less. A difference in water conductivity before and after washing of less than 100 μS / cm is preferable because recycled resin with low haze can be obtained. In one embodiment, the difference (K2-K1) between the water conductivity before washing (K1) and the water conductivity after washing (K2) is preferably less than 100 μS / cm, more preferably 50 μS / cm or less, even more preferably 30 μS / cm or less, particularly preferably 10 μS / cm or less, and most preferably 5 μS / cm or less.

[0143] <Second embodiment> The second embodiment relates to a method for producing recycled resin from a waste resin composition. The method includes a step (a2) of contacting activated carbon with a waste resin solution containing the waste resin composition to obtain a recycled resin solution, and a step (b2) of contacting the recycled resin solution with water at 40 to 100°C to precipitate a recycled resin. The method may further include a step of preparing a waste resin composition before the step (a2). The method may also further include a step (c2) of dehydrating the recycled resin after the step (b2). In one embodiment, the second embodiment includes a step of preparing a waste resin composition, step (a2), step (b2), and step (c2) in this order. This embodiment allows for the production of recycled resin that contains no or almost no organic impurities. As a result, the resulting recycled resin exhibits little or no yellowing. Each step is described below.

[0144] [Step of preparing waste resin composition] The process for preparing the waste resin composition is the same as in the first embodiment, and therefore a description thereof will be omitted here.

[0145] [Process (a2)] The step (a2) is a step of bringing activated carbon into contact with a waste resin solution in which a waste resin composition is dissolved, to obtain a regenerated resin solution.

[0146] (Waste resin solution) The waste resin solution contains a waste resin composition and a solvent, and may also contain dust from outside, metal components mixed in during the molding and crushing processes, etc.

[0147] Waste resin composition As the waste resin composition, the above-mentioned one is used.

[0148] In the second embodiment, the desired synthetic resin (recycled resin) preferably includes a polycarbonate resin, a polyester resin, or a polyester carbonate resin, and more preferably includes a polycarbonate resin. In one embodiment, the desired synthetic resin (recycled resin) preferably includes a resin having at least one structural unit selected from the group consisting of general formulas (1) to (5).

[0149] On the other hand, the organic impurities preferably include low-molecular-weight organic impurities, coloring impurities, etc. These organic impurities are preferred because, unlike the desired synthetic resin (recycled resin), they are easily adsorbed by activated carbon upon contact with it.

[0150] The content of the waste resin composition in the waste resin solution is preferably 2 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 5 to 15% by mass. A waste resin composition content of 2% by mass or more is preferred because the amount of solvent used can be reduced. On the other hand, a waste resin composition content of 30% by mass or less is preferred because the waste resin solution does not become a viscous liquid, or becomes almost viscous, thereby increasing the efficiency of removing organic impurities. In one embodiment, the solvent is preferably methylene chloride, as described below, and therefore the waste resin solution is preferably a 2 to 30% by mass methylene chloride solution, more preferably a 5 to 20% by mass methylene chloride solution, and even more preferably a 5 to 15% by mass methylene chloride solution.

[0151] solvent The solvent is not particularly limited, but is preferably one that can dissolve at least a portion of the desired synthetic resin (recycled resin) and has a boiling point of 100° C. or less. Specific examples of solvents include methylene chloride (boiling point: 40° C.), chloroform (boiling point: 61° C.), ethylene chloride (boiling point: 84° C.), trichloroethylene (boiling point: 87° C.), tetrahydrofuran (boiling point: 66° C.), ethyl acetate (boiling point: 77° C.), isopropyl acetate (boiling point: 89° C.), acetone (boiling point: 56° C.), methyl ethyl ketone (MEK) (boiling point: 80° C.), and benzene (boiling point: 80° C.). Of these, the solvent is preferably methylene chloride (boiling point: 40°C), chloroform (boiling point: 61°C), tetrahydrofuran (boiling point: 66°C), or acetone (boiling point: 56°C), more preferably methylene chloride (boiling point: 40°C), chloroform (boiling point: 61°C), or tetrahydrofuran (boiling point: 66°C), and even more preferably methylene chloride. The above-mentioned solvents may be used alone or in combination of two or more.

[0152] The boiling point of the solvent is preferably 100° C. or less, more preferably 90° C. or less, even more preferably 80° C. or less, particularly preferably 70° C. or less, very preferably 60° C. or less, and most preferably 50° C. or less. If the boiling point of the solvent is 100° C. or less, the solvent is easily volatilized in step (b2) described below, making it easier to obtain an aqueous slurry, which is preferable.

[0153] (activated carbon) The activated carbon is not particularly limited, and any known activated carbon can be used.

[0154] The specific surface area of ​​activated carbon is 30 to 2000 m 2 / g, and 50 to 500m 2 / g. It is more preferable that the specific surface area of ​​the activated carbon is 30m 2 On the other hand, when the specific surface area of ​​activated carbon is 2000 m / g or more, the adsorption effect is high, which is preferable. 2 / g or less is preferable because it is possible to increase the flow rate during continuous activated carbon treatment and, for example, when an activated carbon filter is used, problems such as clogging can be easily prevented. In this specification, the "specific surface area of ​​activated carbon" means a value measured by the BET method.

[0155] The pore diameter of the activated carbon is preferably 0.1 nm to 1 μm, and more preferably 1 to 100 μm. When the pore diameter of the activated carbon is 0.1 nm or more, it is preferable because it easily adsorbs unnecessary substances. On the other hand, when the pore diameter of the activated carbon is 1 μm or less, it is preferable because it easily adsorbs unnecessary substances. Here, the "pore diameter of the activated carbon" means a value measured by a gas adsorption method (constant volume method).

[0156] The surface polarity of the activated carbon may be hydrophobic or hydrophilic, but is preferably hydrophobic from the viewpoint of efficiently removing organic impurities. In order to control the surface polarity of the activated carbon, the activated carbon may be surface-modified.

[0157] The shape of the activated carbon is not particularly limited, and may be any of powder, granules, rods, needles, fibers, sheets, and filters. When the amount of waste resin solution is small (less than 1 L), it is preferable to use powder or granules. When the amount of waste resin solution is large (1 L or more), it is preferable to use sheet or filter shapes.

[0158] The amount of activated carbon used is preferably 0.001 to 0.1 parts by mass, more preferably 0.001 to 0.05 parts by mass, and even more preferably 0.001 to 0.03 parts by mass, per 100 parts by mass of the waste resin solution. When the amount of activated carbon used is 0.001 parts by mass or more, the adsorption effect is improved, which is preferable. On the other hand, when the amount of activated carbon used is 0.1 parts by mass or less, the production cost can be reduced, which is preferable.

[0159] The contact method is not particularly limited, but examples include a method in which activated carbon is added to a waste resin solution and a method in which the waste resin solution is passed through activated carbon. Of these, a method in which activated carbon is added to a waste resin solution is preferred. In this case, the activated carbon may be added all at once or in two or more portions. Furthermore, during contact, stirring or shaking is preferred, with stirring being more preferred, from the viewpoint of promoting contact between the organic impurities and the activated carbon.

[0160] The contact time is not particularly limited, but is preferably 1 minute to 100 hours, more preferably 0.3 to 100 hours, even more preferably 3 to 75 hours, particularly preferably 5 to 50 hours, and most preferably 10 to 40 hours. A contact time of 1 minute or more is preferred because organic impurities can be sufficiently removed. On the other hand, a contact time of 100 hours or less is preferred because production costs are reduced.

[0161] After the contact, the activated carbon is usually removed by solid-liquid separation such as filtration or centrifugation.

[0162] In one embodiment, the waste resin solution may be contacted with two or more activated carbons in succession. For example, the waste resin solution may be passed through a first filter-shaped activated carbon and a second filter-shaped activated carbon in succession. In this case, the first filter-shaped activated carbon and the second filter-shaped activated carbon may have the same or different specific surface area, pore diameter, surface polarity, amount used, etc. Furthermore, the contact method, contact time, etc. may also be the same or different.

[0163] In one embodiment, the waste resin solution may be contacted with activated carbon two or more times. For example, the waste resin solution may be contacted with activated carbon two or more times in a batch system. In this case, the activated carbon used, the contact method, and the contact time may be the same or different.

[0164] (Recycled resin solution) The regenerated resin solution contains a regenerated resin and a solvent. The regenerated resin solution may contain organic impurities that were not completely removed by contact with activated carbon. Although activated carbon is usually removed from the solution after the contact, at least a portion of the activated carbon may remain in the regenerated resin solution.

[0165] [Process (b2)] Step (b2) is a step of bringing the recycled resin solution into contact with water at 40 to 100°C to precipitate the recycled resin. Recycled resin can also be obtained by removing the solvent from the recycled resin solution, but in this case, the resulting recycled resin will be in the form of a mixture of various shapes, such as powder and lumps, or in the form of lumps. By performing step (b2), on the other hand, the solvent can be removed and the recycled resin can be made into a uniform shape (powder, granules, etc.).

[0166] (Recycled resin solution) The regenerated resin solution used is the one described above.

[0167] (40-100℃ water) The water is not particularly limited and may be any of pure water, tap water, groundwater, etc., but from the viewpoint of improving the quality of the recycled resin, it is preferable to use pure water. These waters may be used alone or in combination of two or more kinds.

[0168] The temperature of the water is 40 to 100°C, preferably 50 to 90°C, and more preferably 55 to 80°C. The temperature of the water is usually set appropriately so as to be in a temperature range that does not evaporate the water but facilitates the volatilization of the solvent. The temperature of the water may be changed during step (b2).

[0169] The amount of water used is preferably 1,000 to 10,000 parts by mass, and more preferably 1,000 to 9,000 parts by mass, per 100 parts by mass of the waste resin solution. When the amount of water used is 1,000 parts by mass or more, this is preferred because it facilitates polymer precipitation and makes it easier to obtain a uniform powder. On the other hand, when the amount of water used is 10,000 parts by mass or less, this is preferred because the amount of water used is reduced, making it easier to handle without increasing the scale.

[0170] (contact) The contact method is not particularly limited, but it is preferable to add the regenerated resin solution to water.

[0171] In this case, the recycled resin solution is preferably added to stirred water. In this case, the stirring is preferably performed by a stirrer having a stirring blade. That is, in one embodiment, it is preferable that step (b2) includes adding the recycled resin solution to water at 40 to 100°C that is stirred by a stirrer having a stirring blade.

[0172] The stirring blades are not particularly limited, but examples thereof include edge turbine blades, disk turbine blades, blade turbine blades, propeller blades, paddle blades, edge paddle blades, inclined paddle blades, jet blades, Allard blades, anchor blades, ribbon blades, and homogenizer blades. Two or more of these stirring blades may be used in a stirrer. Furthermore, when the stirrer includes two or more stirring blades, the types of these stirring blades may be the same or different.

[0173] Specific examples of the agitator include a reciprocating rotary agitator agitator, a pipeline agitator, a jet agitator agitator, a rotary agitator agitator, a side agitator agitator, a disperser agitator, and a portable agitator agitator (manufactured by Shimazaki Engineering Co., Ltd.).

[0174] The method of addition is not particularly limited, but dropwise addition is preferred. The dropwise addition time varies depending on the amount of recycled resin solution used, but is preferably 5 minutes to 3 hours, and more preferably 10 minutes to 1 hour.

[0175] The contact time is not particularly limited and differs depending on the amount of regenerated resin solution used, but is preferably 5 minutes to 3 hours, more preferably 10 minutes to 1 hour.

[0176] In step (b2), the regenerated resin solution is brought into contact with water at 40 to 100° C., so that at least a portion of the solvent contained in the regenerated resin solution is volatilized and removed. In step (b2), it is preferable to remove the solvent to obtain a water slurry containing the regenerated resin and water.

[0177] Methods for removing the solvent include extending the contact time and heating the recycled resin after precipitation (after granulation). When the water temperature is approximately 100°C (e.g., 95 to 100°C), the solvent removal method is preferably a method of extending the contact time. When the water temperature is low (e.g., less than 95°C, preferably 40 to 80°C), the solvent removal method is preferably a method of heating the recycled resin after precipitation. Of these, the latter method is preferred from the viewpoint of effectively granulating the recycled resin. That is, in one embodiment, step (b2) is preferably a step of contacting a recycled resin solution containing recycled resin and solvent with water at 40 to 100°C, preferably less than 95°C, more preferably 40 to 80°C, to precipitate the recycled resin and obtain a mixture containing recycled resin, water, and solvent, and then heating the mixture to remove the solvent and obtain an aqueous slurry containing recycled resin and water. Removing the solvent in step (b2) is preferred because it allows the solvent to be recovered alone, enabling recycling and providing benefits such as high safety.

[0178] In this case, the temperature after heating is set taking into consideration the boiling point of the solvent, and is preferably 50 to 100°C, more preferably 60 to 100°C, even more preferably 80 to 100°C, and particularly preferably 95 to 100°C.

[0179] After step (b1), the mixed liquid containing the recycled resin, water, and solvent, preferably the aqueous slurry containing the recycled resin and water, can be subjected to treatments such as filtration and centrifugation to obtain the recycled resin.

[0180] (Process (c2)) The second embodiment may further include step (c2). Step (c2) is a step of dehydrating the recycled resin after step (b2). The solid recycled resin obtained in step (b2) may contain water. Therefore, by dehydrating the recycled resin, a recycled resin suitable for molding or the like can be obtained. Note that, depending on the dehydration method, solvent that may remain in the recycled resin may also be removed.

[0181] The dehydration treatment is not particularly limited, but is preferably drying. The drying temperature is preferably 100 to 200° C., more preferably 110 to 180° C. The drying temperature can also be lowered by using a reduced pressure environment.

[0182] (recycled resin) The recycled resin obtained by the above method is granulated into particles (pellets, etc.), which makes it easy to handle and allows it to be molded as is.

[0183] <Third embodiment> The third embodiment relates to a method for producing recycled resin from a waste resin composition, which includes a step (a3) ​​of hydrocyclone-treating a slurry containing the waste resin composition and water to separate the recycled resin. The method may further include a step of preparing a waste resin composition before the step (a3). Alternatively, the method may further include a step (b3) of dehydrating the recycled resin after the step (a3). In one embodiment, the second embodiment includes a step of preparing a waste resin composition, step (a3), and step (b3) in this order. According to this embodiment, a recycled resin containing no or almost no organic impurities can be produced. As a result, the resulting recycled resin has low haze.

[0184] 2 is a schematic diagram of a cyclone separator used in the third embodiment. A slurry 31 containing a waste resin composition and water is introduced into a cyclone separator 40. In this embodiment, recycled resin 32, which has a high specific gravity, is discharged from the bottom of the cyclone separator 40, and impurity resin 33, which has a low specific gravity, is discharged from the top of the cyclone separator 40, together with water. The cyclone separator 40 has an upper cylindrical portion 42 equipped with a first discharge mechanism 41 and an inverted cone portion 44 equipped with a second discharge mechanism 43.

[0185] 3 is a diagram showing the mechanism of a hydrocyclone when the cyclone separator used in the third embodiment is used. Slurry 31 is introduced from the upper cylindrical portion 42, and a downward flow is generated by the influence of gravity. Specifically, the slurry 31 moves downward while drawing a spiral along the wall surface of the inverted cone portion 44. When the slurry 31 reaches the bottom of the inverted cone portion 44, it reverses direction and rises, generating an upward flow in the center, which is then discharged from the first discharge mechanism 41.

[0186] Here, the recycled resin with a high specific gravity in the slurry 31 settles in the downward flow and is discharged through the second discharge mechanism 43. On the other hand, the impurity resin with a low specific gravity in the slurry 31 is discharged from the first discharge mechanism 41 together with the upward flow. As a result, the recycled resin and the impurity resin can be separated (step (a3)). The mixture of the recycled resin 32 and water discharged from the second discharge mechanism 43 can be dehydrated in a centrifugal dehydrator (not shown) to obtain the recycled resin 32 (step (b3)).

[0187] In the second discharge mechanism 43 of the inverted cone section 44, the smallest diameter is called the orifice diameter, and adjusting this orifice diameter makes it possible to control the flow rate and other factors of the cyclone process. In addition, in the inverted cone section 44, the largest angle formed when the two side lines (corresponding to the generatrix of the cone) of the inverted cone section 44 are extended and intersect is called the cone angle, and adjusting this cone angle makes it possible to control the flow rate and other factors of the cyclone process.

[0188] In this way, by utilizing the difference in physical properties between the desired synthetic resin (recycled resin) and the organic impurities, recycled resin can be produced from a waste resin composition containing the desired synthetic resin (recycled resin) and the organic impurities. Each step will be described below.

[0189] [Step of preparing waste resin composition] The process for preparing the waste resin composition is the same as in the first embodiment, and therefore a description thereof will be omitted here.

[0190] [Process (a3)] The step (a3) ​​is a step of subjecting a slurry containing a waste resin composition and water to hydrocyclone treatment to separate a recycled resin.

[0191] (slurry) The slurry contains a waste resin composition and water.

[0192] Waste resin composition As the waste resin composition, the above-mentioned one is used.

[0193] In the third embodiment, the desired synthetic resin (recycled resin) preferably includes a polycarbonate resin, a polyester resin, or a polyester carbonate resin, and more preferably includes a polycarbonate resin. In one embodiment, the desired synthetic resin (recycled resin) preferably includes a resin having at least one structural unit selected from the group consisting of general formulas (1) to (5).

[0194] The organic impurities preferably include cyclic polyolefins (cycloolefin polymers). In this case, the cyclic polyolefin preferably includes a cycloolefin copolymer having two or more structural units. These organic impurities are preferred because they have a smaller specific gravity than polycarbonate resins and can be suitably separated by cyclone treatment.

[0195] The content of organic impurities in the waste resin composition is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 1% by mass or less, based on the total mass of the waste resin composition. A content of 20% by mass or more in the waste resin composition is preferred because the organic impurities can be suitably removed by cyclone treatment. Even when the content of organic impurities is high, the organic impurities can be removed stepwise by repeating the cyclone treatment.

[0196] The organic impurities preferably include cyclic polyolefins (cycloolefin polymers). Therefore, in one embodiment, the waste resin composition includes a cycloolefin polymer, and the content of the cycloolefin polymer is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 1% by mass or less, based on the total mass of the waste resin composition.

[0197] The content of the waste resin composition in the slurry is preferably 1 to 10% by mass, more preferably 3 to 10% by mass, and even more preferably 5 to 7% by mass, based on the total mass of the slurry. A waste resin composition content of 1% by mass or more is preferred because it improves processing capacity. On the other hand, a waste resin composition content of 10% by mass or less is preferred because it improves separation ability.

[0198] water The water is not particularly limited and may be any of pure water, tap water, groundwater, etc., but from the viewpoint of improving the quality of the recycled resin, it is preferable to use pure water. These waters may be used alone or in combination of two or more kinds.

[0199] The amount of water used is preferably 1,000 to 10,000 parts by mass, more preferably 1,000 to 7,000 parts by mass, and even more preferably 1,000 to 3,000 parts by mass, per 100 parts by mass of the waste resin composition. Using 1,000 parts by mass or more of water is preferred because it eliminates or reduces the viscosity of the slurry, facilitating rotation in hydrocyclone treatment. On the other hand, using 10,000% by mass or less of water is preferred because it improves treatment capacity.

[0200] (hydrocyclone treatment) Hydrocyclone (liquid cyclone) treatment separates components in a slurry by utilizing the difference in specific gravity of the components.

[0201] The device used for hydrocyclone treatment is not particularly limited, but it is preferable to use a cyclone separator having an upper cylindrical portion equipped with a first discharge mechanism and an inverted cone portion equipped with a second discharge mechanism.

[0202] It is preferable to set the conditions for the hydrocyclone treatment appropriately so that the desired synthetic resin (recycled resin) and organic impurities can be separated, such as the flow rate of the hydrocyclone treatment, the cone angle of the inverted cone, the orifice diameter of the first discharge mechanism, the orifice diameter of the second discharge mechanism, and the structure of the cyclone separator.

[0203] The flow rate of the hydrocyclone treatment is preferably 500 to 800 L / min, more preferably 550 to 750 L / min, and even more preferably 600 to 700 L / min. A flow rate of 500 L / min or higher is preferred because it improves productivity. On the other hand, a flow rate of 800 L / min or lower is preferred because it reduces energy costs. The flow rate of the hydrocyclone treatment can be adjusted by appropriately changing the pressure of the pump or other device that introduces the slurry, the cone angle of the inverted cone section, the orifice diameter of the first discharge mechanism in the upper cylindrical section, the orifice diameter of the second discharge mechanism in the inverted cone section, and the structure of the cyclone separator. In this specification, the term "flow rate of the hydrocyclone treatment" refers to the rate at which the slurry is introduced into the inlet, specifically the upper cylindrical section. The flow rate of the hydrocyclone treatment can be measured by placing a flow rate meter at the slurry introduction portion in the upper cylindrical portion.

[0204] The cone angle of the inverted cone portion is preferably 10 to 35 degrees, more preferably 15 to 25 degrees. A cone angle of 10 degrees or more is preferable because it improves the throughput. On the other hand, a cone angle of 35 degrees or less is preferable because it improves the separation ability of the cyclone treatment. That is, in one embodiment, the hydrocyclone treatment is performed using a cyclone separator having an upper cylindrical portion equipped with a first discharge mechanism and an inverted cone portion equipped with a second discharge mechanism, and the cone angle of the inverted cone portion is preferably 10 to 35 degrees, more preferably 15 to 25 degrees. As described above, the cone angle refers to the maximum angle formed when the two lateral lines (corresponding to the generatrix of the cone) of the inverted cone portion intersect when extended. Adjusting the cone angle can change the centrifugal force applied to the slurry, the flow velocity of the slurry, and other factors.

[0205] The orifice diameter of the first discharge mechanism is preferably 30 to 500 mm, more preferably 40 to 100 mm. An orifice diameter of 30 mm or more is preferable because it improves the throughput. On the other hand, an orifice diameter of 500 mm or less is preferable because it improves the separation ability. That is, in one embodiment, the hydrocyclone treatment is performed using a cyclone separator having an upper cylindrical portion equipped with the first discharge mechanism and an inverted cone portion equipped with the second discharge mechanism, and the orifice diameter of the first discharge mechanism is preferably 30 to 500 mm, more preferably 40 to 100 mm. Note that the orifice diameter of the first discharge mechanism refers to the smallest diameter of the first discharge mechanism. Adjusting the orifice diameter of the first discharge mechanism changes the discharge speed of the ascending flow, allowing the flow rate of the cyclone treatment to be controlled.

[0206] The orifice diameter of the second discharge mechanism is preferably 10 to 50 mm, more preferably 15 to 30 mm, even more preferably 18 to 27 mm, particularly preferably 18 to 25 mm, extremely preferably 21 to 25 mm, and most preferably 23 to 25 mm. An orifice diameter of 10 mm or more is preferred from the viewpoints of improving throughput and preventing clogging. On the other hand, an orifice diameter of 50 mm or less is preferred from the viewpoint of improving separation ability. That is, in one embodiment, the hydrocyclone treatment is performed using a cyclone separator having an upper cylindrical portion equipped with the first discharge mechanism and an inverted cone portion equipped with the second discharge mechanism, and the orifice diameter of the second discharge mechanism is preferably 10 to 50 mm, more preferably 15 to 30 mm, even more preferably 18 to 27 mm, particularly preferably 18 to 25 mm, extremely preferably 21 to 25 mm, and most preferably 23 to 25 mm. The orifice diameter of the second discharge mechanism refers to the smallest diameter of the second discharge mechanism. By adjusting the orifice diameter of the second discharge mechanism, the discharge speed at which the downward flow is received and discharged from the second discharge mechanism can be varied, thereby controlling the flow rate of the cyclone treatment, etc.

[0207] The structure of the cyclone separator is not particularly limited, and examples thereof include a structure in which a baffle plate that affects the flow of the downward flow is provided on the inner surface of the inverted cone section through which the downward flow passes, a structure in which a barrier that affects the flow of the upward flow is provided in the center of the inverted cone section through which the upward flow passes, and a structure that combines these.

[0208] (Separation of recycled resin) The method for separating the recycled resin is not particularly limited. For example, if the specific gravity of the recycled resin is greater than that of the organic impurities, the recycled resin is discharged together with water from the second discharge mechanism in the inverted cone section by the downward flow. On the other hand, if the specific gravity of the recycled resin is less than that of the organic impurities, the recycled resin is discharged together with water from the first discharge mechanism in the upper cylindrical section by the upward flow. The recycled resin separated in this manner is usually obtained in the form of a mixed liquid containing recycled resin and water.

[0209] When the specific gravity of the organic impurities is smaller than that of the recycled resin, they are extracted from the first discharge mechanism in the upper cylindrical section in the form of a mixed liquid containing the organic impurities and water, and when the specific gravity of the organic impurities is larger than that of the recycled resin, they are extracted from the second discharge mechanism in the inverted cone section in the form of a mixed liquid containing the organic impurities and water.

[0210] The mixed liquid containing the recycled resin and water obtained from the second discharge mechanism can be subjected to treatment such as filtration and centrifugation to remove the water and obtain the recycled resin.

[0211] The mixed liquid containing the recycled resin and water obtained from the first discharge mechanism can also be subjected to processing such as filtration and centrifugation to remove water and obtain organic impurities.

[0212] From an economical viewpoint, it is preferable to reuse the water removed as water for preparing the slurry. By circulating the water in this way, the production cost can be reduced. The removed water can be appropriately purified.

[0213] [Process (b3)] Step (b3) is a step of dehydrating the recycled resin after step (a3). The recycled resin obtained in step (a3) ​​may contain water. Therefore, by dehydrating the recycled resin, a recycled resin suitable for molding or the like can be obtained.

[0214] The dehydration treatment is not particularly limited, but is preferably drying. The drying temperature is preferably 100 to 200° C., more preferably 110 to 180° C. The drying temperature can also be lowered by using a reduced pressure environment.

[0215] (recycled resin) The chemical structure of the recycled resin obtained by the above method remains unchanged or remains almost unchanged throughout the manufacturing process, making it suitable for use in plastic products as is.

[0216] <Fourth embodiment> The fourth embodiment relates to a method for producing a recycled resin from a waste resin composition. The method includes a step (a4) of treating a waste resin composition containing a resin having at least one structural unit selected from the group consisting of the following general formulas (1) to (4) with an alkaline aqueous solution to obtain at least one dihydroxy compound selected from the group consisting of the following general formulas (1') to (4'). The method may further include a step of preparing a waste resin composition before the step (a4). Furthermore, the method may further include a step (b4) of obtaining a recycled resin containing at least one structural unit selected from the group consisting of the following general formulas (1) to (4) from the dihydroxy compound after the step (a4). In one embodiment, the fourth embodiment includes a step of preparing a waste resin composition, step (a4), and step (b4) in this order. According to this embodiment, a recycled resin containing no or almost no organic impurities can be produced. As a result, the resulting recycled resin has low haze.

[0217] [ka]

[0218] In the above formula, X a , X b , X c , X d , X e , and X f ;R a , R b , R c , R d , R e , and R f a, b, c, d, e, and f; and R g is the same as above.

[0219] [ka]

[0220] In the above formula, X a , X b, X c , X d , X e , and X f ;R a , R b , R c , R d , R e , and R f a, b, c, d, e, and f; and R g is the same as above.

[0221] As described above, in the fourth embodiment, recycled resin is produced by utilizing the difference in chemical properties between the desired synthetic resin and organic impurities contained in the waste resin composition. That is, the desired synthetic resin is at least partially depolymerized under alkaline conditions to form the desired synthetic resin monomer. The recycled resin can be obtained by repolymerizing the monomer. Each step is described below.

[0222] [Step of preparing waste resin composition] The process for preparing the waste resin composition is the same as that of the first embodiment, and therefore will not be described here. The desired resin (recycled resin) contained in the waste resin composition is a resin having at least one structural unit selected from the group consisting of general formulas (1) to (4), as will be described later.

[0223] [Process (a4)] Step (a4) is a step of treating a waste resin composition containing a resin having at least one structural unit selected from the group consisting of general formulas (1) to (4) with an alkaline aqueous solution to obtain at least one dihydroxy compound selected from the group consisting of general formulas (1') to (4').

[0224] (Waste resin composition) The waste resin composition contains a resin having at least one structural unit selected from the group consisting of general formulas (1) to (4), and may further contain organic impurities.

[0225] resin The resin is a resin having at least one structural unit selected from the group consisting of general formulas (1) to (4). Therefore, the resin is usually a polycarbonate resin. This resin corresponds to the desired synthetic resin. The resin may have one of the structural units alone or two or more of them in combination.

[0226] Specific examples of the structural units represented by general formulas (1) to (4) are as described above.

[0227] The resin may further contain other structural units. Examples of such structural units include, but are not limited to, structural units derived from olefins and structural units derived from esters. The resin may contain such other structural units alone or in combination of two or more.

[0228] The above-mentioned resins may be contained alone in the waste resin composition, or two or more kinds may be mixed and contained.

[0229] The weight-average molecular weight (Mw) of the resin is not particularly limited, but is preferably 10,000 to 70,000, and more preferably 15,000 to 50,000. If the weight-average molecular weight (Mw) of the resin is 10,000 or more, it is preferable because it can maintain appropriate strength as a molded product, such as a resin for an optical lens. On the other hand, if the weight-average molecular weight (Mw) of the resin is 70,000 or less, it is preferable because it can maintain appropriate fluidity during resin molding and improve moldability.

[0230] The content of the resin in the waste resin composition is preferably 80% by mass or more, and more preferably 80 to 99% by mass, based on the mass of the waste resin composition. When the content of the resin is 80% by mass or more, it is preferable because the efficiency is high.

[0231] organic impurities Examples of organic impurities include impurity resins, impurity compounds, etc. The impurity resins and impurity compounds are as described above.

[0232] Of these, the impurity resin is preferably a polyolefin resin or a cyclic polyolefin, more preferably a cyclic polyolefin, from the viewpoint of the large difference in chemical properties between the impurity resin and the polycarbonate resin (large difference in ease of depolymerization in an alkaline aqueous solution).

[0233] (alkaline aqueous solution) The alkaline aqueous solution contains a metal oxide and water.

[0234] The metal oxide is not particularly limited, but examples thereof include alkali metals such as sodium hydroxide, potassium hydroxide, and rubidium hydroxide; and alkaline earth metals such as calcium hydroxide and barium hydroxide. Of these, the metal oxide is preferably an alkali metal, more preferably sodium hydroxide or potassium hydroxide, and even more preferably potassium hydroxide. These metal oxides may be used alone or in combination of two or more.

[0235] The amount of the metal oxide used is not particularly limited, but is preferably 1.5 to 10 moles, more preferably 2 to 8 moles, and even more preferably 2 to 4 moles, per mole of carbonate bond in the polycarbonate resin. A metal oxide used in an amount of 1.5 moles or more is preferred because depolymerization is sufficiently carried out. On the other hand, a metal oxide used in an amount of 10 moles or less is preferred because production costs are reduced.

[0236] The concentration of the metal oxide in the alkaline aqueous solution is preferably 10 to 60% by mass, more preferably 15 to 55% by mass, and even more preferably 20 to 50% by mass, based on the total mass of the alkaline aqueous solution. A metal oxide concentration of 10% by mass or more is preferred because it increases the depolymerization reaction rate. On the other hand, a metal oxide concentration of 60% by mass or less is preferred because it prevents the alkaline aqueous solution from becoming a slurry and facilitates the reaction.

[0237] (Reaction solvent) The depolymerization in step (a4) is usually carried out in a reaction solvent.

[0238] The reaction solvent is not particularly limited, but examples thereof include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents.

[0239] The aliphatic hydrocarbon solvent is not particularly limited, but examples thereof include pentane, hexane, heptane, octane, nonane, decane, cyclohexane, and cyclodecane.

[0240] The aromatic hydrocarbon solvent is not particularly limited, but examples thereof include toluene, xylene, and mesityle.

[0241] Among these, the reaction solvent is preferably an aromatic hydrocarbon solvent, more preferably toluene or xylene. The above-mentioned reaction solvents may be used alone or in combination of two or more.

[0242] The amount of reaction solvent used is not particularly limited, but is preferably 30 to 2000 parts by mass, more preferably 40 to 1500 parts by mass, and even more preferably 100 to 1000 parts by mass, per 100 parts by mass of the waste resin composition. When the amount of reaction solvent used is 30 parts by mass or more, the organic components of the waste resin composition are sufficiently dissolved in the reaction solvent, thereby increasing the reaction efficiency, which is preferable. On the other hand, when the amount of reaction solvent used is 2000 parts by mass or less, the reaction time is shortened, which is preferable.

[0243] (process) The treatment of the waste resin composition with an alkaline aqueous solution is usually carried out in a reaction solvent. Therefore, in one embodiment, the treatment is preferably carried out by adding the waste resin composition and the alkaline aqueous solution to a reaction solvent and reacting them.

[0244] The organic impurities contained in the waste resin composition have different chemical properties during depolymerization compared to the above-mentioned resins. Therefore, the organic impurities either do not react, are depolymerized earlier than the above-mentioned resins, or are depolymerized later than the above-mentioned resins. For example, organic impurities such as polyolefin resins and cyclic polyolefins do not usually react under basic conditions, so only the above-mentioned resins are depolymerized and can be easily removed. Even if the organic impurities are depolymerized, the depolymerized products of the organic impurities usually have a different polarity from the dihydroxy compounds and can be easily removed.

[0245] The treatment temperature (depolymerization reaction temperature) is not particularly limited, but is preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 30 to 90° C. A treatment temperature of 120° C. or lower is preferred because side reactions can be prevented.

[0246] After the treatment (depolymerization), it is preferable to obtain a dihydroxy compound by carrying out a purification step such as washing, extraction, recrystallization, etc. It is preferable to recover unreacted resin, partially depolymerized dimer, oligomer, etc. in the purification step and reuse them by, for example, subjecting them to depolymerization again.

[0247] (Dihydroxy compounds) The dihydroxy compound is at least one selected from the group consisting of general formulas (1') to (4'). A hydroxy compound can be obtained by depolymerizing a resin having at least one structural unit selected from the group consisting of general formulas (1) to (4) to monomer units. When the resin is a copolymer having two or more structural units of general formulas (1) to (4), the dihydroxy compound can be a composition containing two or more dihydroxy compounds. In this case, the two or more dihydroxy compounds in the composition can be isolated by purifying the composition.

[0248] [Process (b4)] The fourth embodiment may further include step (b4). Step (b4) is a step, performed after step (a4), of obtaining a recycled resin containing at least one structural unit selected from the group consisting of general formulas (1) to (4) from the dihydroxy compound. By performing step (b4), a recycled resin containing at least one structural unit selected from the group consisting of general formulas (1) to (4) can be obtained from at least one dihydroxy compound selected from the group consisting of general formulas (1') to (4').

[0249] The recycled resin can be obtained from the dihydroxy compound by a known polymerization technique. In one embodiment, the recycled resin can be produced by subjecting the dihydroxy compound and the carbonate diester to a solution condensation method in the presence of a basic compound catalyst and / or a transesterification catalyst, or in the absence of a catalyst.

[0250] The carbonate diester is not particularly limited, but examples thereof include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. Among these, diphenyl carbonate is preferred.

[0251] The amount of the diester carbonate compound used is preferably 0.97 to 1.20 mol, more preferably 0.98 to 1.10 mol, and even more preferably 1.00 to 1.10 mol, per 1 mol of the dihydroxy compound.

[0252] The basic compound catalyst is not particularly limited, but examples thereof include alkali metal compounds, alkaline earth metal compounds, and nitrogen-containing compounds.

[0253] The alkali metal compound is not particularly limited, and examples thereof include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, and alkoxides of alkali metals.Specific examples thereof include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenylborohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, disodium salt, dipotassium salt, dicesium salt, or dilithium salt of bisphenol A, and sodium salt, potassium salt, cesium salt, or lithium salt of phenol.

[0254] The alkaline earth metal compound is not particularly limited, but may be an organic compound of an alkaline earth metal compound. Examples of the salt include acid salts, inorganic salts, oxides, hydroxides, hydrides, and alkoxides. Specific examples include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, and magnesium phenylphosphate.

[0255] The nitrogen-containing compound is not particularly limited, but may be a quaternary ammonium hydroxide, and amines. Specific examples include quaternary ammonium hydroxides having an alkyl group, an aryl group, or the like, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide; tertiary amines such as triethylamine, dimethylbenzylamine, and triphenylamine; secondary amines such as diethylamine and dibutylamine; primary amines such as propylamine and butylamine; imidazoles such as 2-methylimidazole, 2-phenylimidazole, and benzimidazole; ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate.

[0256] Examples of the transesterification catalyst include salts of zinc, tin, zirconium, lead, etc. Specific examples include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin(II) chloride, tin(IV) chloride, tin(II) acetate, tin(IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead(II) acetate, and lead(IV) acetate.

[0257] The above-mentioned basic compound catalysts and transesterification catalysts may be used alone or in combination of two or more kinds.

[0258] The amount of basic compound catalyst and transesterification catalyst (total amount when used in combination) used is 1 x 10 per mole of dihydroxy compound. -9 ~1×10 -3 mol, preferably 1×10 -7 ~1×10 -4 More preferably, it is moles.

[0259] In the melt polycondensation method, it is desirable to melt a dihydroxy compound and a carbonate diester in a reaction vessel and then carry out the reaction in a state in which the produced monohydroxy compound remains. In order to retain the monohydroxy compound, the pressure can be controlled by, for example, closing the reaction vessel or reducing or increasing the pressure.

[0260] The recycled resin obtained by the above method can be suitably used in plastic products. [Example]

[0261] The present invention will be described in detail below with reference to examples, but the technical scope of the present invention is not limited thereto. Unless otherwise specified, "parts" and "%" in the examples represent "parts by mass" and "% by mass", respectively.

[0262] [Manufacturing example] A waste resin composition was produced by the following method.

[0263] The raw materials were 4.53 kg (12.1 mol) of 9,9-bis[6-(2-hydroxyethoxy)naphthalen-2-yl]fluorene (BNEF), 7.5 kg (20.03 mol) of 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BHEBN), 8.72 kg (14.8 mol) of 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene (BPPEF), 5.99 kg (27.9 mol) of diphenyl carbonate (DPC), and 2.5 × 10 -2 16 ml (4.0 x 10 mol / L) of sodium bicarbonate (NaHCO3) solution -4 mole, i.e., 8.4 × 10 per mole of the total of dihydroxy compounds -6(mol) was placed in a 50-L reactor equipped with a stirrer and distillation device and heated from 25°C to 180°C over 30 minutes under a nitrogen atmosphere of 760 mmHg. Complete dissolution of the raw materials was confirmed 30 minutes after the start of heating. Stirring was then continued at 180°C for 120 minutes. The vacuum was then adjusted to 200 mmHg, and the temperature was raised to 200°C at a rate of 60°C / hr. During this time, the start of distillation of by-product phenol was confirmed. The reaction was then continued at 200°C for 20 minutes. The temperature was then raised to 230°C at a rate of 75°C / hr. 10 minutes after the temperature increase, the vacuum was reduced to 1 mmHg or less over 2 hours while maintaining the temperature. The temperature was then raised to 245°C at a rate of 60°C / hr, and stirring was continued for an additional 40 minutes. After the reaction was completed, nitrogen was introduced into the reactor to return to normal pressure, and the resulting thermoplastic resin was pelletized and removed. Since the structural formulae of BNEF, BHEBN, BPPEF, and DPC are as follows, the produced thermoplastic resin is a polycarbonate resin.

[0264] [ka]

[0265] The resin obtained above was melt-kneaded with 15 ppm by weight of tetrabutylphosphonium dodecylbenzenesulfonate (MGA-614, manufactured by Takemoto Oil & Fat Co., Ltd.) as a deactivator, 300 ppm by weight of 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (PEP-36, manufactured by ADEKA Corporation) as a mold release agent, and 1000 ppm by weight of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (AO-60, manufactured by ADEKA Corporation) as an antioxidant, and then pelletized.

[0266] The resulting pellets were used to mold optical lenses in an injection molding machine, and the runners and sprues obtained as the lenses were molded were collected and used as waste resin compositions.

[0267] Example 1: First Embodiment A recycled resin was produced from a waste resin composition according to the first embodiment. The waste resin composition used was that produced in the Production Example. The desired synthetic resin was a polycarbonate resin.

[0268] [Example 1-1] (Step (a1)) In a 5 L container, 500 g of the waste resin composition and 5 mass % salt water (specific gravity: 1.04 g / cm 3 2.0 L of ethanol was added and stirred for 10 minutes with a stirrer. Floating organic impurities were removed, and the brine was separated by filtration to obtain a recycled resin composition.

[0269] (Process (b1)) The recycled resin composition and 2.0 L of water (electrical conductivity: 0 μS / cm) were added to a 5 L container and stirred for 10 minutes. The water was then removed by filtration and the mixture was dehydrated using a dehydrator to produce recycled resin.

[0270] (Process (c1)) The conductivity of the washed water obtained by filtration in the above step (b1) was measured, and the result was that the conductivity was 2 μS / cm.

[0271] [Example 1-2] In step (a1), 10 mass % salt water (specific gravity: 1.07 g / cm 3 A recycled resin was produced in the same manner as in Example 1, except that ) was used.

[0272] [Examples 1-3] In step (a1), 20 mass % salt water (specific gravity: 1.16 g / cm 3 A recycled resin was produced in the same manner as in Example 1, except that ) was used.

[0273] [Comparative Example 1-1] A recycled resin was produced in the same manner as in Example 1, except that water was used in step (a1).

[0274] [Comparative Example 1-2] In step (a1), 20 mass % salt water (specific gravity: 1.16 g / cm 3 A recycled resin was produced in the same manner as in Example 1, except that step (b1) was not carried out.

[0275] [evaluation] The recycled resins obtained in Examples 1-1 to 1-3 and Comparative Examples 1-1 and 1-2 were measured for haze and coloration.

[0276] (Hayes) The resin was injection molded using an SH50 injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., with a cylinder temperature of 260°C and a mold temperature 30°C lower than the glass transition temperature of the resin, to obtain a 3 mm thick disk. The haze (Hz) was measured using a Nippon Denshoku NDH2000.

[0277] (Coloring degree) The resin was injection molded using an injection molding machine SH50 manufactured by Sumitomo Heavy Industries, Ltd., with a cylinder temperature of 260°C and a mold temperature 30°C lower than the glass transition temperature of the resin, to obtain a 3 mm thick disk. The yellowness index (YI) was measured using this disk. The SE2000 manufactured by Nippon Denshoku Industries Co., Ltd. was used to measure the yellowness index (YI).

[0278] The results obtained are shown in Table 1 below.

[0279] [Table 1]

[0280] The results in Table 1 show that organic impurities were successfully removed in Examples 1-1 to 1-3. Furthermore, the low conductivity difference (C1-C2) values ​​in Examples 1-1 to 1-3 indicate that almost no salt remains in the recycled resin. As a result, the resulting recycled resin has low haze and can be used effectively as a recycled resin.

[0281] On the other hand, in Comparative Example 1-1, organic impurities could not be sufficiently removed, and the resulting recycled resin had a high haze. In Comparative Example 1-2, the conductivity difference (C1-C2) was high because step (b1) was not performed, and salt remained in the recycled resin, resulting in a high haze.

[0282] Example 2: Second embodiment According to the second embodiment, a recycled resin was produced from a waste resin composition. The waste resin composition used was the one produced in the Production Example. The desired synthetic resin was a polycarbonate resin.

[0283] [Example 2-1] (Step (a2)) 8 g of the waste resin composition and 80 mL (110 g) of methylene chloride were placed in a 200 mL Erlenmeyer flask and stirred with a magnetic stirrer to dissolve the waste resin composition, thereby obtaining a waste resin solution (waste resin content: 6.8 mass %).

[0284] 10 mg of activated carbon was added to the waste resin solution and stirred for 0.1 hours. The activated carbon was removed by filtration to obtain a regenerated resin solution.

[0285] The yellowness index (YI) of the recycled resin solution was measured as follows. Specifically, the recycled resin solution was placed in a quartz cell with an optical path length of 6 cm, and the YI was measured using a spectrophotometer. The SE2000 manufactured by Nippon Denshoku Industries Co., Ltd. was used to measure the yellowness index (YI). As a result, the yellowness index (YI) of the recycled resin solution was 12.5.

[0286] (Process (b2)) The regenerated resin solution obtained in step (a2) was added dropwise to 800 g of water at 60°C while stirring with an agitator. The regenerated resin precipitated while the solvent, methylene chloride (boiling point 40°C), evaporated. As a result, a water slurry of the regenerated resin was obtained. The water slurry was filtered to obtain the regenerated resin.

[0287] (Process (c2)) Furthermore, the recycled resin obtained in step (b2) was subjected to a dehydration treatment such as drying to obtain a powdery recycled resin.

[0288] [Example 2-2] A regenerated resin solution was obtained in the same manner as in Example 1, except that the stirring time after the addition of activated carbon in step (a2) was changed from 0.1 hour to 1 hour. The yellowness index (YI) of the regenerated resin solution was measured in the same manner as in Example 1 and was found to be 10.8.

[0289] The recycled resin can be obtained by carrying out the steps (b2) and (c2) in the same manner as in Example 1.

[0290] [Example 2-3] Except for changing the stirring time after the addition of activated carbon in step (a2) from 0.1 hours to 24 hours, a regenerated resin solution was obtained in the same manner as in Example 1. The yellowness index (YI) of the regenerated resin solution was measured in the same manner as in Example 1 and was found to be 9.9.

[0291] The recycled resin can be obtained by carrying out the steps (b2) and (c2) in the same manner as in Example 1.

[0292] [Example 2-4] A regenerated resin solution was obtained in the same manner as in Example 1, except that the stirring time after the addition of activated carbon in step (a2) was changed from 0.1 hours to 72 hours. The yellowness index (YI) of the regenerated resin solution was measured in the same manner as in Example 1 and was found to be 9.5.

[0293] The recycled resin can be obtained by carrying out the steps (b2) and (c2) in the same manner as in Example 1.

[0294] [Example 2-5] A regenerated resin solution was obtained in the same manner as in Example 1, except that the amount of activated carbon added in step (a2) was changed from 10 mg to 20 mg and the stirring time after the addition of activated carbon was changed from 0.1 hour to 24 hours. The yellowness index (YI) of the regenerated resin solution was measured in the same manner as in Example 1 and was found to be 9.9.

[0295] The recycled resin can be obtained by carrying out the steps (b2) and (c2) in the same manner as in Example 1.

[0296] [Example 2-6] A regenerated resin solution was obtained in the same manner as in Example 1, except that the amount of activated carbon added in step (a2) was changed from 10 mg to 30 mg and the stirring time after the addition of activated carbon was changed from 0.1 hour to 24 hours. The yellowness index (YI) of the regenerated resin solution was measured in the same manner as in Example 1 and was found to be 9.7.

[0297] The recycled resin can be obtained by carrying out the steps (b2) and (c2) in the same manner as in Example 1.

[0298] [Comparative Example 2-1] Except for not adding activated carbon in step (a2), a regenerated resin solution was obtained in the same manner as in Example 1. The yellowness index (YI) of the regenerated resin solution was measured in the same manner as in Example 1 and was found to be 13.

[0299] The recycled resin can be obtained by carrying out the steps (b2) and (c2) in the same manner as in Example 1.

[0300] The results obtained in Examples 2-1 to 2-6 and Comparative Example 2-1 are shown in Table 2 below.

[0301] [Table 2]

[0302] The results in Table 2 show that in Examples 2-1 to 2-6, the organic impurities contained in the waste resin solution were adsorbed onto the activated carbon, thereby enabling the organic impurities to be removed and the yellowness index YI to be reduced.

[0303] [Example 2-7] (Step (a2)) A waste resin solution was obtained in the same manner as in Example 2-1, except that 20 g of the waste resin composition was used (waste resin content: 15.4 mass %).

[0304] 10 mg of activated carbon was added to the waste resin solution and stirred for 24 hours. The activated carbon was removed by filtration to obtain a regenerated resin solution.

[0305] (Process (b2)) 20 g of the regenerated resin solution obtained in step (a2) was added dropwise to 1.2 kg of 60°C water (pure water) over 15 minutes while stirring with an agitator (a stirrer with stirring blades). During this process, powdery regenerated resin precipitated as the solution was added. The resulting solution was then heated to 100°C and heated for 10 minutes, causing further regenerated resin precipitation and volatilizing the methylene chloride (boiling point: 40°C) in the solution. As a result, a water slurry of the regenerated resin was obtained.

[0306] (Process (c2)) The water slurry obtained in step (b2) was filtered, dried and dehydrated to obtain a regenerated resin.

[0307] <Example 3: Third embodiment> According to the third embodiment, a recycled resin was produced from a waste resin composition.

[0308] [Example 3-1] (Step (a3)) The waste resin composition produced in the Production Example was mixed with cycloolefin copolymer as an organic impurity to a concentration of 1068 ppm. The resin mixture thus prepared was used as the waste resin composition. The desired synthetic resin was a polycarbonate resin. The haze of the waste resin composition was measured in the same manner as in Example 1 and was found to be 36.24%.

[0309] 25.0 kg of the waste resin composition was added to 500 kg of water to prepare a slurry (concentration: 5% by mass), which was then subjected to cyclone treatment using a cyclone separator.

[0310] The cyclone separator had an upper cylindrical section equipped with a first discharge mechanism and an inverted cone section equipped with a second discharge mechanism. The cone angle of the inverted cone section was 22 degrees, and the orifice diameter of the second discharge mechanism was 20 mm. The outer diameter of the first discharge mechanism was 250 mm.

[0311] The cyclone treatment was carried out under conditions such that the flow rate of the slurry at the inlet was 804 L / min.

[0312] When suspended matter (organic impurities including cycloolefin copolymer) was removed from the discharged liquid discharged from the first discharge mechanism of the upper cylindrical portion, the amount of organic impurities was found to be 155 g.

[0313] (Process (b3)) The aqueous slurry discharged from the second discharge mechanism was centrifuged to obtain 24.3 kg of recycled resin, which had a water absorption rate of 0.35% by mass.

[0314] The concentration of cycloolefin copolymer in the resulting recycled resin was measured and found to be 106 ppm. The concentration of cycloolefin copolymer was measured using the following method. First, 600 g of recycled resin was placed in 10% by mass salt water and stirred. The floating resin was then recovered and washed with pure water. This washing was repeated until the electrical conductivity of the wastewater (water after washing) was 10 μS / cm or less. After washing, the resulting recycled resin was dried and dissolved in 100 mL of methylene chloride. The resulting solution was then suction filtered using filter paper, and the mass of the residue was measured. The concentration of cycloolefin copolymer in the recycled resin was calculated from the weight of 600 g of recycled resin and the mass of the residue (weight of residue (g) / 600 g of precipitate × 1,000,000).

[0315] The haze of the recycled resin was measured in the same manner as in Example 1 and was found to be 1.76%.

[0316] [Example 3-2] A recycled resin was produced in the same manner as in Example 3-1, except that the orifice diameter of the second discharge mechanism of the cyclone separator was set to 22 mmφ.

[0317] The concentration of cycloolefin copolymer in the recycled resin and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 60 ppm and 1.74%, respectively.

[0318] [Example 3-3] A recycled resin was produced in the same manner as in Example 3-1, except that the orifice diameter of the second discharge mechanism of the cyclone separator was set to 24 mmφ.

[0319] The concentration of cycloolefin copolymer in the recycled resin and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 58 ppm and 1.10%, respectively.

[0320] [Example 3-4] A recycled resin was produced in the same manner as in Example 3-1, except that the orifice diameter of the second discharge mechanism of the cyclone separator was set to 26 mmφ.

[0321] The concentration of cycloolefin copolymer in the recycled resin and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 120 ppm and 4.60%, respectively.

[0322] [Examples 3-5] A recycled resin was produced in the same manner as in Example 3-1, except that the orifice diameter of the second discharge mechanism of the cyclone separator was set to 28 mmφ.

[0323] The concentration of cycloolefin copolymer in the recycled resin and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 480 ppm and 8.82%, respectively.

[0324] The results obtained in Examples 3-1 to 3-5 are shown in Table 3 below.

[0325] [Table 3]

[0326] The results in Table 3 show that in Examples 3-1 to 3-5, the cycloolefin copolymer could be removed from the waste resin composition, and recycled resins with low haze were obtained.

[0327] [Examples 3-6] The waste resin composition produced in the production example was mixed with cycloolefin copolymer as an organic impurity to a concentration of 5297 ppm. The resin mixture thus prepared was used as the waste resin composition. The desired synthetic resin was a polycarbonate resin. The haze of the waste resin composition was measured in the same manner as in Example 3-1 and was found to be 97.81%.

[0328] A recycled resin was produced in the same manner as in Example 3-1, except that the above waste resin composition was used (first treatment).

[0329] The concentration of cycloolefin copolymer in the recycled resin obtained by the first treatment and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 202 ppm and 4.66%, respectively.

[0330] A recycled resin was produced in the same manner as in Example 3-1, except that the recycled resin obtained in the first treatment was used (second treatment).

[0331] The concentration of cycloolefin copolymer in the recycled resin obtained by the second treatment and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 86 ppm and 0.86%, respectively.

[0332] A recycled resin was produced in the same manner as in Example 3-1, except that the recycled resin obtained in the second treatment was used (third treatment).

[0333] The concentration of cycloolefin copolymer in the recycled resin obtained by the third treatment and the haze of the recycled resin were measured in the same manner as in Example 3-1, and were found to be 51 ppm and 0.64%, respectively.

[0334] The results obtained in the first to third treatments of Examples 3-6 are shown in Table 4 below.

[0335] [Table 4]

[0336] The results in Table 4 show that even when the organic impurity content is very high, the organic impurities can be removed effectively to obtain recycled resin. It also shows that the more times the cyclone treatment is performed, the more effectively the organic impurities are removed.

[0337] Example 4: Fourth embodiment [Example 4-1] (Process (a4)) A reactor equipped with a stirrer and a condenser was charged with 100 parts by weight of polycarbonate resin containing structural units derived from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF), 88 parts by weight of 48% aqueous sodium hydroxide, and 734 parts by weight of toluene, and the mixture was heated to reflux for 3 hours. The mixture was then cooled to 80-85°C, and 178 parts by weight of ion-exchanged water was added. After stirring and allowing to stand, the aqueous phase was separated, and the organic phase was washed with ion-exchanged water. After partially distilling off the toluene from the organic phase, the mixture was filtered, 23 parts of ion-exchanged water was added, and the mixture was cooled to room temperature with stirring. The precipitated crystals were filtered and dried, yielding 85 parts by weight of white crystals of 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF).

[0338] [ka]

[0339] These results demonstrate that polycarbonate resins containing BPEF-derived structural units can be depolymerized under basic conditions. Since organic impurities such as polyolefin resins and cyclic polyolefins do not normally react under basic conditions, it is clear that when these organic impurities are present in polycarbonate resins, they can be removed during the BPEF crystal filtration stage.

[0340] Furthermore, the obtained BPEF can be reacted with a carbonic acid diester by, for example, a solution condensation method (step (b4)), to produce a recycled resin containing the structural units of BPEF.

[0341] [Example 4-2] Crystals were obtained in the same manner as in Example 4-1, except that a polycarbonate resin containing structural units derived from 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene (BPPEF) and 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BHEBN) (BPPEF:BHEBN = 70 mol:30 mol) was used instead of the polycarbonate resin containing structural units derived from BPEF. BPPEF and BHEBN were isolated by crystallization of the obtained crystals.

[0342] [ka]

[0343] The above results demonstrate that polycarbonate resins containing structural units derived from BPPEF and BHEBN can be depolymerized under basic conditions. Organic impurities such as polyolefin resins and cyclic polyolefins generally do not react under basic conditions. Therefore, when these organic impurities are present in polycarbonate resins, they can be removed during the crystallization and filtration of BPPEF and BHEBN. The polycarbonate resins containing structural units derived from BPPEF and BHEBN are random copolymers, and in the above formula, A and B are each independently an integer, and C is an integer.

[0344] Furthermore, the obtained BPPEF and BHEBN can be reacted with a carbonic acid diester by, for example, a solution condensation method (step (b4)), to produce a recycled resin containing structural units of BPPEF and BHEBN. [Explanation of symbols]

[0345] 11 Waste resin composition raw materials 12 Waste resin composition 13 Water (before washing) 14 Water (after washing) 15 Recycled Resin 21 Crusher 22 Feeder 23 Transport route 24 Brine Tank 25 Stirring element 26 Outlet 27 Cleaning Tank 28 Transport route 29 Dehydrator 31 Slurry 32 Recycled Resin 33 Impurity Resin 40 Cyclone separator 41 First Ejection Mechanism 42 Upper cylindrical part 43 Secondary Emission Mechanism 44 Inverted cone section

Claims

1. A method for producing recycled resin from a waste resin composition, comprising: a step (a1) of contacting the waste resin composition with 1 to 30% by mass of salt water to obtain a recycled resin composition; A step (b1) of washing the recycled resin composition with water to obtain a recycled resin; Including, The recycled resin is represented by the following general formulas (1) to (5): 【Chemistry 1】 [During the ceremony, Xa, Xb, Xc, Xd, Xe, and Xf each independently represent an alkylene group having 1 to 4 carbon atoms; R a , R b , R c , R d , R e , and R f are each independently selected from a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; a, b, c, d, e, and f each independently represent an integer of 0 to 10; h, i, j, k, m, and n each independently represent an integer of 0 to 4; R g and R h each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.] The method of manufacturing the polymer, comprising:

2. The waste resin composition is represented by the following general formulas (6) to (8): 【Chemistry 2】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method of claim 1, further comprising an impurity resin having at least one constitutional unit selected from the group consisting of:

3. A method for producing recycled resin from a waste resin composition, comprising: a step (a1) of contacting the waste resin composition with 1 to 30% by mass of salt water to obtain a recycled resin composition; A step (b1) of washing the recycled resin composition with water to obtain a recycled resin; Including, The waste resin composition is a compound represented by the following general formulas (6) to (8): 【Transformation 3】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method of manufacturing includes an impurity resin having at least one constitutional unit selected from the group consisting of:

4. The method according to any one of claims 1 to 3, further comprising, after step (b1), step (c1) of measuring the conductivity of the water after washing.

5. The water conductivity (K １ ) and the water conductivity after washing (K ２ ) and the difference (K ２ -K １ 5. The method according to claim 1, wherein the electrical conductivity of the film is less than 100 μS / cm.

6. The method according to any one of claims 1 to 5, wherein the waste resin composition has a longest diameter of 5 cm or less.

7. A method for producing recycled resin from a waste resin composition, comprising: a step (a2) of contacting activated carbon with the waste resin solution in which the waste resin composition is dissolved to obtain a regenerated resin solution; a step (b2) of contacting the regenerated resin solution with water at 40 to 100°C to precipitate the regenerated resin; Including, The recycled resin is represented by the following general formulas (1) to (5): 【Chemistry 4】 [During the ceremony, Xa, Xb, Xc, Xd, Xe, and Xf each independently represent an alkylene group having 1 to 4 carbon atoms; R a , R b , R c , R d , R e , and R f are each independently selected from a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; a, b, c, d, e, and f each independently represent an integer of 0 to 10; h, i, j, k, m, and n each independently represent an integer of 0 to 4; R g and R h each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.] The method of manufacturing the polymer, comprising:

8. The waste resin composition is represented by the following general formulas (6) to (8): 【Transformation 5】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method of claim 7, further comprising an impurity resin having at least one constitutional unit selected from the group consisting of:

9. A method for producing recycled resin from a waste resin composition, comprising: a step (a2) of contacting activated carbon with the waste resin solution in which the waste resin composition is dissolved to obtain a regenerated resin solution; a step (b2) of contacting the regenerated resin solution with water at 40 to 100°C to precipitate the regenerated resin; Including, The waste resin composition is a compound represented by the following general formulas (6) to (8): 【Transformation 6】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method of manufacturing includes an impurity resin having at least one constitutional unit selected from the group consisting of:

10. The manufacturing method according to any one of claims 7 to 9, wherein the waste resin solution is a 5 to 20 mass% methylene chloride solution.

11. The method according to any one of claims 7 to 10, wherein the amount of activated carbon used is 0.001 to 0.1 parts by mass per 100 parts by mass of the waste resin solution.

12. The method according to any one of claims 7 to 11, wherein the amount of water used is 1,000 to 10,000 parts by mass per 100 parts by mass of the waste resin solution.

13. The manufacturing method according to any one of claims 7 to 12, wherein the step (b2) comprises adding the regenerated resin solution to water at 40 to 100 ° C. stirred by a stirrer having a stirring blade.

14. The method according to any one of claims 7 to 13, further comprising a step (c2) of dehydrating the recycled resin after the step (b2).

15. A method for producing recycled resin from a waste resin composition, comprising: A step (a3) ​​of subjecting the slurry containing the waste resin composition and water to hydrocyclone treatment to separate a recycled resin, The recycled resin is represented by the following general formulas (1) to (5): 【Transformation 7】 [During the ceremony, Xa, Xb, Xc, Xd, Xe, and Xf each independently represent an alkylene group having 1 to 4 carbon atoms; R a , R b , R c , R d , R e , and R f are each independently selected from a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; a, b, c, d, e, and f each independently represent an integer of 0 to 10; h, i, j, k, m, and n each independently represent an integer of 0 to 4; R g and R h each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.] The method of manufacturing the polymer, comprising:

16. The waste resin composition is represented by the following general formulas (6) to (8): 【Transformation 8】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method of claim 15, further comprising an impurity resin having at least one constitutional unit selected from the group consisting of:

17. A method for producing recycled resin from a waste resin composition, comprising: A step (a3) ​​of subjecting the slurry containing the waste resin composition and water to hydrocyclone treatment to separate a recycled resin, The waste resin composition is a compound represented by the following general formulas (6) to (8): 【Chemistry 9】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The method of manufacturing includes an impurity resin having at least one constitutional unit selected from the group consisting of:

18. the waste resin composition contains a cycloolefin polymer, The manufacturing method according to any one of claims 15 to 17, wherein the content of the cycloolefin polymer is 20 mass% or less with respect to the total mass of the waste resin composition.

19. The manufacturing method according to any one of claims 15 to 18, wherein the content of the waste resin composition is 1 to 10 mass% with respect to the total mass of the slurry.

20. The method according to any one of claims 15 to 19, wherein the amount of water used is 1,000 to 10,000 parts by mass per 100 parts by mass of the waste resin composition.

21. The method according to any one of claims 15 to 20, wherein the flow rate of the hydrocyclone treatment is 500 to 800 L / min.

22. the hydrocyclone treatment is performed by a cyclone separator having an upper cylindrical portion with a first discharge mechanism and an inverted cone portion with a second discharge mechanism; The manufacturing method according to any one of claims 15 to 21, wherein the inverted cone portion has a cone angle of 10 to 35 degrees.

23. the hydrocyclone treatment is performed by a cyclone separator having an upper cylindrical portion with a first discharge mechanism and an inverted cone portion with a second discharge mechanism; The manufacturing method according to any one of claims 15 to 22, wherein the orifice diameter of the second discharge mechanism is 10 to 50 mm.

24. The method according to any one of claims 15 to 23, further comprising, after the step (a3), a step (b3) of dehydrating the recycled resin.

25. The manufacturing method according to any one of claims 15 to 24, wherein the mass of the recycled resin is 80 mass% or more relative to the mass of the waste resin composition.

26. A method for producing recycled resin from a waste resin composition, comprising: The following general formulas (1) to (4): 【Chemistry 10】 [During the ceremony, X ａ , X ｂ , X ｃ , X ｄ , X ｅ , and X ｆ each independently represents an alkylene group having 1 to 4 carbon atoms, R ａ , R ｂ , R ｃ , R ｄ , R ｅ , and R ｆ each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, an aryloxy group having 6 to 20 carbon atoms, and —C≡C—R ｉ is selected from R ｉ represents an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; a, b, c, d, e, and f each independently represent an integer of 0 to 10; h, i, j, k, m, and n each independently represent an integer of 0 to 4; R ｇ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. A waste resin composition containing a resin having at least one structural unit selected from the group consisting of: 【Chemistry 11】 (a4) obtaining at least one dihydroxy compound selected from the group consisting of:

27. ​​The waste resin composition is represented by the following general formulas (6) to (8): 【Chemistry 12】 [During the ceremony, Each X g independently represents an alkylene group having 1 to 10 carbon atoms; R j , R k , and R l are each independently selected from a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted cycloalkoxy group having 5 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms containing one or more hetero ring atoms selected from O, N, and S, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, and —C≡C—R i ; R i represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 3 to 20 carbon atoms and containing one or more hetero ring atoms selected from O, N, and S; Each p independently represents an integer of 0 or 1; q, r, and s each independently represent an integer of 0 to 10; t represents an integer of 1 to 3; wherein, when q is 2 or more and two R j s are present on adjacent carbon atoms, the two R j s may be joined together to form a ring structure; When r is 2 or more and two R k s are present on adjacent carbon atoms, the two R k s may be joined together to form a ring structure; When s is 2 or more and two R l s are present on adjacent carbon atoms, the two R l s may be joined together to form a ring structure; R m represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

27. The method of claim 26, comprising an impurity resin having at least one constitutional unit selected from the group consisting of:

28. The method according to claim 26 or 27, further comprising, after the step (a4), a step (b4) of obtaining a recycled resin containing at least one structural unit selected from the group consisting of general formulas (1) to (4) from the dihydroxy compound.

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