Method for manufacturing alicyclic structure-containing polymer recycled product

Abstract

The purpose of the present invention is to provide a method for manufacturing an alicyclic structure-containing polymer recycled product having an excellent filtration rate. The present invention relates to a method for manufacturing an alicyclic structure-containing polymer recycled product from a fabricated body that contains an alicyclic structure-containing polymer which is a first polymer and that contains a second polymer different from the first polymer, the method including: a polymer solution preparation step for using the fabricated body to acquire a polymer solution obtained by the alicyclic structure-containing polymer being dissolved in a dissolution solvent A; a heating step for heating the polymer solution to a temperature of Bp°C to Bp+100°C when the boiling point of the dissolution solvent A is Bp°C; a cooling step for cooling the polymer solution after the heating step; and a filtration step for filtering the polymer solution after the cooling step to obtain a filtrate containing the alicyclic structure-containing polymer.

Description

Method for producing recycled polymer containing alicyclic structure

[0001] The present invention relates to a method for producing a recycled product of a polymer containing an alicyclic structure.

[0002] Alicyclic structure-containing polymers have excellent properties such as transparency, heat resistance, moisture resistance, chemical resistance, and electrical properties, and are therefore widely used in various fields such as optical materials, medical materials, and electrical component materials. This results in the generation of large amounts of waste materials after the use of molded articles containing the alicyclic structure-containing polymers, as well as waste materials produced during the production of the molded articles.

[0003] In recent years, recovery and reuse of alicyclic structure-containing polymers from waste materials of molded articles containing alicyclic structure-containing polymers and other polymers has been studied. For example, Patent Document 1 proposes a method for recovering cyclic olefin-based resins from composite materials containing a cyclic olefin-based resin (alicyclic structure-containing polymer) and a different resin other than the cyclic olefin-based resin without melting on the premise of separation, the method comprising: a first step of dissolving a composite material containing at least a cyclic olefin-based resin and a different resin other than the cyclic olefin-based resin in a solvent capable of dissolving the cyclic olefin-based resin at a temperature below the boiling point of the solvent to produce a solution and precipitate the different resin component containing the different resin; a second step of filtering the solution and removing the different resin component to obtain a filtrate; and a third step of obtaining a composition containing the cyclic olefin-based resin from the filtrate.

[0004] International Publication No. 2023 / 054541

[0005] Here, when obtaining a recycled product of the alicyclic structure-containing polymer from a molded body containing the alicyclic structure-containing polymer and a polymer different from the alicyclic structure-containing polymer, the molded body can be dissolved in a predetermined solvent and then filtered. However, since this filtration takes time, it is desirable to increase the filtration speed.

[0006] Therefore, an object of the present invention is to provide a method for producing a regenerated product of an alicyclic structure-containing polymer that has an excellent filtration rate.

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems, and have newly discovered that the above-mentioned problems can be solved by a method for producing a regenerated product of an alicyclic structure-containing polymer, the method comprising: a heating step of heating a polymer solution obtained by using a molded product containing an alicyclic structure-containing polymer as a first polymer and a second polymer different from the first polymer to a predetermined temperature range; a cooling step of cooling the polymer solution after the heating step; and a filtration step of filtering the polymer solution after the cooling step to obtain a filtrate, thereby completing the present invention.

[0008] That is, the present invention aims to advantageously solve the above-mentioned problems, and [1] the present invention is a method for producing a recycled product of an alicyclic structure-containing polymer from a molded body containing a first polymer, an alicyclic structure-containing polymer, and a second polymer different from the first polymer, comprising: a polymer solution preparation step using the molded body to obtain a polymer solution in which the alicyclic structure-containing polymer is dissolved in a dissolving solvent A; a heating step in which the polymer solution is heated to a temperature of Bp ° C or higher and Bp + 100 ° C or lower, where Bp ° C is the boiling point of the dissolving solvent A; a cooling step in which the polymer solution after the heating step is cooled; and a filtration step in which the polymer solution after the cooling step is filtered to obtain a filtrate containing the alicyclic structure-containing polymer. The above-mentioned method for producing a recycled product of an alicyclic structure-containing polymer has excellent filtration speed. As used herein, the term "second polymer different from the first polymer" refers to a second polymer that differs from the first polymer in at least one of the following: the type and content of monomer units, the presence or absence of crystallinity, and solubility in a specific solvent. Note that "different solubility" typically means that the solubility (unit: g / 100 g) in 100 g of solvent at 25°C differs by 5 g / 100 g or more. As used herein, the boiling point of dissolution solvent A refers to the boiling point at atmospheric pressure (1 atm), and can be measured using a normal pressure method in accordance with JIS K2254.

[0009] [2] The method for producing a regenerated alicyclic structure-containing polymer according to [1] above preferably further comprises a precipitation step in which the filtrate obtained in the filtration step is mixed with a precipitating solvent to prepare a mixture, thereby precipitating a precipitate containing the alicyclic structure-containing polymer, and a precipitating solvent removal step in which the precipitating solvent is removed from the mixture after the precipitation step to obtain the precipitate. If the method for producing a regenerated alicyclic structure-containing polymer further comprises a precipitation step and a precipitating solvent removal step, the second polymer can be effectively removed, improving the purity of the regenerated alicyclic structure-containing polymer obtained. In addition, additives that may be added when producing a molded body (hereinafter sometimes referred to as "old additives") can be effectively removed, improving the removability of old additives.

[0010] [3] In the method for producing the regenerated product of the alicyclic structure-containing polymer according to [2], the mixed solution is preferably prepared by adding the filtrate to the precipitation solvent. By preparing the mixed solution by adding the filtrate to the precipitation solvent, the purity of the regenerated product of the alicyclic structure-containing polymer obtained can be further improved.

[0011] [4] In the method for producing a recycled product of an alicyclic structure-containing polymer according to [1] above, the polymer solution preparation step preferably includes: a first step of dissolving the molded body in a dissolving solvent B to obtain a solution; a second step of mixing the solution obtained in the first step with a precipitating solvent to prepare a mixed solution and precipitating a precipitate containing the alicyclic structure-containing polymer; a third step of removing the precipitating solvent from the mixed solution after the second step to obtain the precipitate; and a fourth step of dissolving the precipitate obtained in the third step in the dissolving solvent A to obtain the polymer solution. If the polymer solution preparation step includes the first to fourth steps, the purity and old additive removal properties of the resulting recycled product of the alicyclic structure-containing polymer can be improved.

[0012] [5] In the method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of [2] to [4] above, the solubility parameter of the precipitation solvent is 7 (cal / cm ３ ) １／２ More than 9.9 (cal / cm ３ ) １／２It is preferable that the solubility parameter of the precipitation solvent is equal to or higher than the lower limit, the yield of the alicyclic structure-containing polymer regenerated product can be effectively increased, and the recoverability of the alicyclic structure-containing polymer regenerated product (hereinafter, sometimes referred to as "regenerated product recoverability") can be improved. On the other hand, if the solubility parameter of the precipitation solvent is equal to or lower than the upper limit, the purity of the obtained alicyclic structure-containing polymer regenerated product can be further improved. In this specification, the "solubility parameter (SP value)" refers to the Hansen solubility parameter (δ) (unit: (cal / cm ３ ) １／２ ) and "δ ２ = δd ２ +δp ２ +δh ２ In the above relational expression, "δd" represents a "contribution term due to intermolecular dispersion forces," "δp" represents a "contribution term due to intermolecular polar interactions," and "δh" represents a "contribution term due to intermolecular hydrogen bonds," each of which is a physical property value depending on the substance type (see Charles M. Hansen, "Hansen Solubility Parameters: A User's Handbook, Second Edition," CRC Press, Boca Raton FL, (2007) (hereinafter also referred to as the "handbook")). For organic solvents not described in handbooks, etc., estimated values ​​calculated using the computer software Hansen Solubility Parameters in Practice (HSPiP) can be used.

[0013] [6] In the method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of [2] to [5] above, the content of the precipitation solvent in the mixed solution is preferably 30% by mass or more and 99% by mass or less. If the content of the precipitation solvent in the mixed solution is equal to or more than the lower limit, the recovery of the regenerated product can be improved. On the other hand, if the content of the precipitation solvent in the mixed solution is equal to or less than the upper limit, the amount of the precipitation solvent used can be effectively reduced, and the productivity of the regenerated product of the alicyclic structure-containing polymer can be improved.

[0014] [7] In the method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of [2] to [6] above, the precipitation temperature when precipitating the precipitate is preferably 15°C or higher and 50°C or lower. If the precipitation temperature is higher than the lower limit, the purity of the obtained regenerated product of an alicyclic structure-containing polymer can be further improved. On the other hand, if the precipitation temperature is lower than the upper limit, the regenerated product recovery property and additive removal property can be further improved.

[0015] [8] In the method for producing a recycled product of an alicyclic structure-containing polymer according to any one of [1] to [7] above, the cooling temperature in the cooling step is preferably 40° C. or lower. If the cooling temperature in the cooling step is equal to or lower than the upper limit, the recoverability of the recycled product can be improved.

[0016] [9] In the method for producing a recycled product of an alicyclic structure-containing polymer according to any one of [1] to [8] above, it is preferable that the alicyclic structure-containing polymer is amorphous and the second polymer is crystalline. If the alicyclic structure-containing polymer is amorphous and the second polymer is crystalline, the recovery of the recycled product can be improved. In this specification, "amorphous polymer" means that the crystallization temperature cannot be measured using a differential scanning calorimeter (DSC), and "crystalline polymer" means that the crystallization temperature can be measured using a differential scanning calorimeter (DSC).

[0017]

[10] In the method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of [1] to [9] above, the heating temperature in the heating step is preferably 80°C or higher and 140°C or lower. If the heating temperature in the heating step is equal to or higher than the lower limit, the filtration rate can be improved. On the other hand, if the heating temperature in the heating step is equal to or lower than the upper limit, the filtration rate can be improved. In addition, the purity of the obtained regenerated product of an alicyclic structure-containing polymer can be further improved.

[0018] According to the present invention, a method for producing a regenerated product of an alicyclic structure-containing polymer having an excellent filtration rate can be provided.

[0019] Hereinafter, embodiments of the present invention will be described in detail.

[0020] (Method for producing recycled alicyclic structure-containing polymer) The method for producing recycled alicyclic structure-containing polymer of the present invention (hereinafter sometimes referred to as "the production method of the present invention") is a method for producing recycled alicyclic structure-containing polymer from a molded body containing a first polymer, an alicyclic structure-containing polymer, and a second polymer different from the first polymer. The production method of the present invention includes a polymer solution preparation step in which a polymer solution in which the alicyclic structure-containing polymer is dissolved in a dissolving solvent A is obtained using the molded body; a heating step in which the polymer solution is heated to a temperature of Bp ° C or higher and Bp + 100 ° C or lower, where Bp ° C is the boiling point of the dissolving solvent A; a cooling step in which the polymer solution after the heating step is cooled; and a filtration step in which the polymer solution after the cooling step is filtered to obtain a filtrate containing the alicyclic structure-containing polymer. The above production method has excellent filtration speed. It is presumed that the reason for this is that by heating the polymer solution to a predetermined temperature and then cooling it, it becomes easier to remove the second polymer as a filtrate.

[0021] Here, the production method of the present invention is not particularly limited, but preferred embodiments include a first embodiment further including a precipitation step in which the filtrate obtained in the filtration step is mixed with a precipitation solvent to prepare a mixed liquid and precipitate a precipitate containing an alicyclic structure-containing polymer, and a precipitation solvent removal step in which the precipitation solvent is removed from the mixed liquid after the precipitation step to obtain a precipitate, and a second embodiment in which the polymer solution preparation step includes the first to fourth steps described below. These embodiments can improve the purity of the obtained alicyclic structure-containing polymer regenerated product and the ability to remove old additives. Note that the first embodiment is more preferred from the viewpoint of effectively improving the purity of the obtained alicyclic structure-containing polymer regenerated product.

[0022] In addition to the above-mentioned polymer solution preparation step, heating step, cooling step, filtration step, precipitation step, and precipitation solvent removal step, the production method of the present invention may optionally include at least one of the following steps: a pulverization step, a sieving step, a new additive addition step, and a drying step, which will be described later.

[0023] <Molded Product> Here, the molded product used in the manufacturing method of the present invention will be described. The molded product used in the manufacturing method of the present invention contains an alicyclic structure-containing polymer as a first polymer and a second polymer different from the first polymer, and may optionally contain other components such as a third polymer different from the first polymer and the second polymer, an additive, etc. In this specification, the term "third polymer different from the first polymer and the second polymer" means that the third polymer is different from the first polymer and the second polymer, respectively, in at least one of the type and content ratio of monomer units, the presence or absence of crystallinity, and solubility in a predetermined solvent.

[0024] The molded article used in the production method of the present invention is obtained by various molding methods such as injection molding, extrusion molding, extrusion blow molding, injection blow molding, multilayer blow molding, injection blow molding, double-wall blow molding, stretch blow molding, vacuum molding, and rotational molding, and is not particularly limited in shape, physical properties, etc. Specific molded articles include molded articles for optical applications such as lenses, prisms, optical films, optical sheets, optical disk substrates, light guide plates, light guides, optical fibers, and mirrors; molded articles for medical applications such as disposable syringes, drug solution vials, drug packaging films, medical device storage containers, test cells, test containers, infusion bags, and syringe rods; molded articles for electrical or electronic applications such as sheets, films, plate materials, containers, and insulating materials for wire coatings, wafer shippers, capacitor films, circuit boards, and connectors; pipes, round bars, bottles, building materials, and stationery. Further, examples of the molded body include waste molded body materials, processing waste materials (eg, film edges, die-cutting residues) generated during the production of molded bodies, and used molded bodies.

[0025] [First Polymer] The first polymer, an alicyclic structure-containing polymer (hereinafter sometimes simply referred to as "first polymer" or "alicyclic structure-containing polymer"), has an alicyclic structure in the main chain and / or side chain. For example, from the viewpoint of the mechanical strength, heat resistance, etc. of the recycled alicyclic structure-containing polymer, those containing an alicyclic structure in the main chain are preferred. Examples of the alicyclic structure of the alicyclic structure-containing polymer include saturated cyclic hydrocarbon (cycloalkane) structures and unsaturated cyclic hydrocarbon (cycloalkene) structures. From the viewpoint of the mechanical strength, heat resistance, etc. of the recycled alicyclic structure-containing polymer, a cycloalkane structure or a cycloalkene structure is preferred, and a cycloalkane structure is more preferred. The number of carbon atoms constituting the alicyclic structure is not particularly limited, but from the viewpoint of maintaining high mechanical strength, heat resistance, and moldability of the recycled alicyclic structure-containing polymer, it is preferably 4 or more, more preferably 5 or more, and preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less.

[0026] The proportion of repeating units (monomer units) having an alicyclic structure in the alicyclic structure-containing polymer is usually 30% by mass or more, preferably 50% by mass or more, and more preferably 70% by mass or more. If the proportion of repeating units having an alicyclic structure in the alicyclic structure-containing polymer is above the above lower limit, for example, the heat resistance of the recycled alicyclic structure-containing polymer can be improved. The remainder other than the repeating units having an alicyclic structure in the alicyclic structure-containing polymer is not particularly limited, and various ones can be used.

[0027] Specific examples of the above-mentioned alicyclic structure-containing polymer include (1) norbornene-based polymers, (2) monocyclic olefin-based polymers, (3) cyclic conjugated diene-based polymers, (4) vinyl alicyclic hydrocarbon-based polymers, and hydrogenated products thereof, which will be described later. Among these, norbornene-based polymers and hydrogenated products thereof, and cyclic conjugated diene-based polymers and hydrogenated products thereof are preferred, and norbornene-based polymers and hydrogenated products thereof are more preferred.

[0028] (1) Norbornene-Based Polymers Norbornene-based polymers are not particularly limited, and examples include those obtained by polymerizing norbornene-based monomers by the methods disclosed in JP-A-3-14882 and JP-A-3-122137. Specific examples include ring-opening polymers of norbornene-based monomers and hydrogenated products thereof, addition polymers of norbornene-based monomers, and addition copolymers of norbornene-based monomers and vinyl compounds. Among these, for example, from the viewpoint of maintaining high heat resistance and dielectric properties of the recycled alicyclic structure-containing polymer, hydrogenated ring-opening polymers of norbornene-based monomers, addition polymers of norbornene-based monomers, and addition copolymers of vinyl compounds copolymerizable with norbornene-based monomers are preferred, with hydrogenated ring-opening polymers of norbornene-based monomers being particularly preferred.

[0029] Examples of norbornene-based monomers include bicyclo[2.2.1]hept-2-ene (common name: norbornene), 5-methyl-bicyclo[2.2.1]hept-2-ene, 5,5-dimethyl-bicyclo[2.2.1]hept-2-ene, 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-hexyl-bicyclo[2.2.1]hept-2-ene, 5-octyl-bicyclo[2.2.1]hept-2-ene, 5-octadecyl-bicyclo[2.2.1]hept-2-ene, and 5-octadecyl-bicyclo[2.2.1]hept-2-ene. bicyclo[2.2.1]hept-2-ene, 5-methylidene-bicyclo[2.2.1]hept-2-ene, 5-ethylidene-bicyclo[2.2.1]hept-2-ene, 5-vinyl-bicyclo[2.2.1]hept-2-ene, 5-propenyl-bicyclo[2.2.1]hept-2-ene, 5-methoxy-carbonyl-bicyclo[2.2.1]hept-2-ene, 5-cyano-bicyclo[2.2.1]hept-2-ene, 5-methyl-5-methoxycarbonyl-bicyclo[2.2.1]hept-2-ene Ene; 5-methoxycarbonylbicyclo[2.2.1]hept-2-ene, 5-ethoxycarbonylbicyclo[2.2.1]hept-2-ene, 5-methyl-5-methoxycarbonylbicyclo[2.2.1]hept-2-ene, 5-methyl-5-ethoxycarbonylbicyclo[2.2.1]hept-2-ene, bicyclo[2.2.1]hept-5-enyl-2-methylpropionate, bicyclo[2.2.1]hept-5-enyl-2-methyloctanate, bicyclo[2.2.1]hept 5-Hydroxymethylbicyclo[2.2.1]hept-2-ene, 5,6-di(hydroxymethyl)bicyclo[2.2.1]hept-2-ene, 5-hydroxy-i-propylbicyclo[2.2.1]hept-2-ene, 5,6-dicarboxybicyclo[2.2.1]hept-2-ene, 5-cyanobicyclo[2.2.1]hept-2-ene, bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic acid imide, tricyclo[4.3.0.1 ２，５ ]deca-3,7-diene (trivial name: dicyclopentadiene), tricyclo[4.3.0.1 ２，５ ]dec-3-ene, tricyclo[4.3.0.1 ２，５]undeca-3,7-diene or tricyclo[4.3.0.1 ２，５ ]undeca-3,8-diene or a partially hydrogenated product thereof (or an adduct of cyclopentadiene and cyclohexene), tricyclo[4.4.0.1 ２，５ ]undec-3-ene, 5-cyclopentyl-bicyclo[2.2.1]hept-2-ene, 5-cyclohexyl-bicyclo[2.2.1]hept-2-ene, 5-cyclohexenylbicyclo[2.2.1]hept-2-ene, 5-phenyl-bicyclo[2.2.1]hept-2-ene, tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene (also simply referred to as "tetracyclododecene"), 8-methyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-ethyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene (common name: ethyltetracyclododecene (ETD)), 8-methylidenetetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-ethylidenetetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-vinyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-propenyl-tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-methoxycarbonyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-hydroxymethyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-carboxytetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene; 8-cyclopentyl-tetracyclo[4.4.0.1 ２，５ .1７，１０ ]-dodec-3-ene, 8-cyclohexyl-tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-cyclohexenyl-tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene, 8-phenyl-cyclopentyl-tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ]-dodec-3-ene; tetracyclo[7.4.0.1 １０，１３ .0 ２，７ ]trideca-2,4,6,11-tetraene (also known as 1,4-methano-1,4,4a,9a-tetrahydrofluorene), tetracyclo[8.4.0.1 １１，１４ .0 ３，８ ]tetradeca-3,5,7,12-tetraene (also known as 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene), pentacyclo[6.5.1.1 ３，６ .0 ２，７ .0 ９，１３ ] pentadeca-3,10-diene, pentacyclo[7.4.0.1 ３，６ .1 １０，１３ .0 ２，７ ]pentadeca-4,11-diene; and norbornene-based monomers such as the tetramer of cyclopentadiene. These norbornene-based monomers can be used either alone or in combination of two or more.

[0030] Examples of vinyl compounds copolymerizable with these norbornene-based monomers include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octane. Examples of copolymerizable vinyl compounds include ethylene or α-olefins having 2 to 20 carbon atoms, such as decene and 1-eicosene; cycloolefins, such as cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-(2-methylbutyl)-1-cyclohexene, cyclooctene, and 3a,5,6,7a-tetrahydro-4,7-methano-1H-indene; and non-conjugated dienes, such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene. These copolymerizable vinyl compounds can be used either alone or in combination of two or more.

[0031] Further examples of copolymerizable vinyl compounds include cyclic olefins, such as monocyclic cycloolefins such as cyclobutene, 1-methylcyclopentene, 3-methylcyclobutene, 3,4-diisopropenylcyclobutene, cyclopentene, 3-methylcyclopentene, cyclohexene, cyclooctene, 1-methylcyclooctene, 5-methylcyclooctene, cyclooctatetraene, and cyclododecene.

[0032] The polymerization method and hydrogenation method of the norbornene-based monomer or the norbornene-based monomer and the copolymerizable vinyl compound are not particularly limited, and can be carried out according to known methods.

[0033] Ring-opening (co)polymers of norbornene-based monomers are prepared by subjecting norbornene-based monomers to ring-opening polymerization using a catalyst system consisting of a halide, nitrate, or acetylacetone compound of a metal such as ruthenium, rhodium, palladium, osmium, iridium, or platinum, and a reducing agent, or a catalyst system consisting of a halide or acetylacetone compound of a metal such as titanium, vanadium, zirconium, tungsten, or molybdenum, and an organoaluminum compound, usually at a polymerization temperature of −50° C. to 100° C. and a pressure of 0 to 50 kg / cm, in a solvent or without a solvent. ２ The ring-opening (co)polymerization can be performed at a polymerization pressure of 1000 MPa (1200 psi). The polymerization activity and the selectivity of the ring-opening polymerization can be increased by adding a third component to the catalyst system, such as molecular oxygen, alcohols, ethers, peroxides, carboxylic acids, acid anhydrides, acid chlorides, esters, ketones, nitrogen-containing compounds, sulfur-containing compounds, halogen-containing compounds, molecular iodine, or other Lewis acids.

[0034] The addition copolymer of a norbornene-based monomer and a vinyl compound can be prepared, for example, by polymerizing the monomer components in a solvent or without a solvent in the presence of a catalyst system comprising a titanium, zirconium, or vanadium compound and an organoaluminum compound at a polymerization temperature of −50° C. to 100° C. and a flow rate of 0 to 50 kg / cm. ２ The copolymer can be obtained by copolymerizing the copolymer under a polymerization pressure of 1000 MPa.

[0035] The hydrogenated norbornene polymer can be obtained by a conventional method in which a ring-opened (co)polymer is hydrogenated with hydrogen in the presence of a hydrogenation catalyst.

[0036] (2) Monocyclic olefin polymers Examples of monocyclic olefin polymers that can be used include addition polymers of monocyclic olefin monomers such as cyclohexene, cycloheptene, and cyclooctene, as disclosed in JP-A-64-66216.

[0037] (3) Cyclic Conjugated Diene Polymers Examples of cyclic conjugated diene polymers that can be used include polymers obtained by 1,2- or 1,4-addition polymerization of cyclic conjugated diene monomers such as cyclopentadiene and cyclohexadiene, and hydrogenated products thereof, as disclosed in, for example, JP-A-6-136057 and JP-A-7-258318.

[0038] (4) Vinyl alicyclic hydrocarbon polymers Examples of vinyl alicyclic hydrocarbon polymers that can be used include polymers of vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane and hydrogenated products thereof, as disclosed in JP-A-51-59989, and hydrogenated products of aromatic ring moieties of polymers of vinyl aromatic monomers such as styrene and α-methylstyrene, as disclosed in JP-A-63-43910 and JP-A-64-1706.

[0039] Here, the alicyclic structure-containing polymer is not particularly limited and may be crystalline or amorphous, but is preferably amorphous since this can improve the recovery of recycled products.

[0040] The weight average molecular weight (Mw) of the alicyclic structure-containing polymer is preferably 5,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, and is preferably 500,000 or less, more preferably 200,000 or less, even more preferably 100,000 or less, and even more preferably 35,000 or less. In this specification, the "weight average molecular weight" can be measured using gel permeation chromatography (GPC). Specifically, it can be measured at 40°C as a standard polyisoprene-equivalent value by gel permeation chromatography (GPC) using cyclohexane as an eluent. Note that, for example, an HLC8120GPC manufactured by Tosoh Corporation can be used as a measuring device.

[0041] The alicyclic structure-containing polymer preferably has a glass transition temperature (Tg) of 50° C. or higher, more preferably 70° C. or higher, and even more preferably 90° C. or higher, and preferably 300° C. or lower, more preferably 250° C. or lower, even more preferably 200° C. or lower, and even more preferably 130° C. or lower. In this specification, the "glass transition temperature" can be measured using a differential scanning calorimeter in accordance with JIS K7121.

[0042] The alicyclic structure-containing polymer preferably has a 5% heat loss temperature (measured in a nitrogen atmosphere at a temperature increase rate of 5° C. / min) of 300° C. or higher, more preferably 350° C. or higher. If the 5% heat loss temperature of the alicyclic structure-containing polymer is equal to or higher than the lower limit, molding defects such as the inclusion of bubbles can be suppressed even when the recycled alicyclic structure-containing polymer is molded at a high temperature to obtain a molded product as a recycled product (hereinafter, sometimes referred to as a "recycled molded product").

[0043] The alicyclic structure-containing polymer usually has a melt viscosity of 1×10 at a temperature of 260° C. １ P (poise) or more, and 1×10 ２ It is preferable that the density is 1×10 or more. ５ P or less, and 1 × 10 ４ If the melt viscosity is within the above range, the moldability and mechanical strength of the recycled alicyclic structure-containing polymer can be maintained at a high level.

[0044] [Second Polymer] The second polymer is not particularly limited as long as it is a polymer different from the first polymer, but it is preferable that the second polymer is a polymer different from the first polymer in terms of whether it is crystalline or not. For example, when the first polymer, the alicyclic structure-containing polymer, is amorphous, it is preferable that the second polymer is crystalline. In other words, it is preferable that the alicyclic structure-containing polymer is amorphous and the second polymer is crystalline. If the alicyclic structure-containing polymer is amorphous and the second polymer is crystalline, the regenerated product recovery can be improved. The reason for this is presumably that if the second polymer is crystalline, the amorphous portion of the second polymer crystallizes during the heating process, and then the second polymer can be easily removed as a solid mass.

[0045] Examples of the crystalline second polymer include polyolefins such as polyethylene and polypropylene, polyamides (nylons), polyesters, and cellulose. Among these, polyolefins are preferred, polypropylene and polyethylene are more preferred, and polypropylene is even more preferred, as they can further improve the purity of the resulting recycled alicyclic structure-containing polymer. The above-mentioned molded product may contain one or more of these polymers. The content of the second polymer in the molded product varies depending on the shape and use of the molded product, and is not particularly limited.

[0046] When the second polymer is crystalline, the crystallization temperature of the second polymer is not particularly limited, and may be, for example, 80° C. or higher, 100° C. or higher, or 130° C. or higher, and may be, for example, 170° C. or lower, or 160° C. or lower. In this specification, the crystallization temperature can be measured according to a differential scanning calorimeter (DSC).

[0047] [Third Polymer] The third polymer that may be optionally contained in the molded product is not particularly limited as long as it is a polymer different from the first polymer and the second polymer, but it is preferable that the third polymer has a solubility in a precipitation solvent described below different from that of the first polymer and a crystallinity different from that of the second polymer. Examples of such a third polymer include a hydrogenated styrene-conjugated diene block copolymer.

[0048] Here, the hydrogenated styrene-conjugated diene block copolymer is a hydrogenated styrene block-conjugated diene block copolymer having a styrene block mainly composed of repeating units derived from a styrene-based monomer and a diene block mainly composed of repeating units derived from a conjugated diene monomer.

[0049] Specific examples of styrene-based monomers that give styrene blocks include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, 4-monochlorostyrene, dichlorostyrene, 4-monofluorostyrene, 4-phenylstyrene, etc. Furthermore, the styrene block may contain, in addition to the repeating units derived from styrene-based monomers, other monomer units such as repeating units derived from other vinyl compounds or repeating units derived from chain conjugated diene compounds.

[0050] Specific examples of the conjugated diene monomer that gives the diene block include linear conjugated diene compounds such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene.

[0051] The diene block may contain, in addition to the repeating units derived from the conjugated diene monomer, other monomer units such as repeating units derived from a styrene-based monomer or repeating units derived from other vinyl compounds.

[0052] Specific examples of the hydrogenated styrene-conjugated diene block copolymer include styrene-ethylene butene block copolymer (SEB), styrene-ethylene butylene-styrene block copolymer (SEBS), and styrene-ethylene propylene-styrene block copolymer (SEPS).

[0053] [Old Additives] Examples of old additives that may be optionally contained in the molded body include additives such as antioxidants, ultraviolet absorbers, light stabilizers, near-infrared absorbers, colorants such as dyes and pigments, lubricants, plasticizers, antistatic agents, and fluorescent brighteners.

[0054] Next, each step that may be included in the production method of the present invention will be described below.

[0055] <Pulverization Step> In the pulverization step, which can be optionally carried out, the molded body is pulverized to obtain a pulverized molded body prior to the polymer solution preparation step.

[0056] The molded body can be pulverized using, for example, a pulverizer or a cutter. By pulverizing the molded body, the dissolution time of the alicyclic structure-containing polymer can be shortened and the dissolution efficiency can be improved.

[0057] <Sieving Step> In the sieving step, which can be optionally carried out between the pulverization step and the polymer solution preparation step, the pulverized molded body is sieved through a sieve having a predetermined pore size (φ).

[0058] The predetermined hole diameter (φ) is usually 3 mm or more, preferably 4 mm or more, more preferably 5 mm or more, and usually 15 mm or less, preferably 12 mm or less, more preferably 10 mm or less. By sieving the compacts through a sieve with a diameter equal to or less than the above-mentioned upper limit to reduce the size of the crushed compacts to be dissolved, the dissolution time can be further shortened and the dissolution efficiency can be improved. On the other hand, by setting the sieve diameter to be equal to or greater than the above-mentioned lower limit, the decrease in recovery efficiency due to crushed compacts that do not pass through the sieve can be suppressed.

[0059] <Polymer Solution Preparation Step> In the polymer solution preparation step, a polymer solution in which the alicyclic structure-containing polymer is dissolved in the dissolution solvent A is obtained using a molded product that has been optionally pulverized and sieved.

[0060] The dissolving solvent A used in the polymer solution preparation step is not particularly limited as long as it is a solvent capable of dissolving the alicyclic structure-containing polymer, i.e., a good solvent for the alicyclic structure-containing polymer. Here, the dissolving solvent A is preferably a poor solvent for the second polymer. If the dissolving solvent A is a poor solvent for the second polymer, the second polymer can exist as an insoluble component in the polymer solution, and therefore the second polymer can be easily removed as a residue in the filtration step after the heating step and the cooling step.

[0061] The SP value of dissolution solvent A is 7 (cal / cm ３ ) １／２ It is preferable that the calorie content is 7.6 (cal / cm ３ ) １／２ More preferably, it is 8.2 (cal / cm ３ ) １／２ More preferably, it is 9.9 (cal / cm ３ )１／２ It is preferable that the calorie content is 9.1 (cal / cm ３ ) １／２ More preferably, it is 8.8 (cal / cm ３ ) １／２ It is more preferable that:

[0062] The boiling point of dissolution solvent A is preferably 75°C or higher, more preferably 80°C or higher, and preferably 170°C or lower, more preferably 130°C or lower, and even more preferably 100°C or lower. When dissolution solvent A contains two or more solvents, i.e., when it is a mixed solvent, the "boiling point of dissolution solvent A" refers to the boiling point of the main component solvent in the mixed solvent. Here, the "main component solvent" refers to the solvent that is contained in the largest amount in the mixed solvent.

[0063] Examples of the dissolution solvent A include methylcyclohexane, cyclohexane, xylene, toluene, etc. Among these, cyclohexane and xylene are preferred, and cyclohexane is more preferred, as they can improve the filtration rate.

[0064] In the polymer solution preparation step, the amount of the molded article used per 100 parts by mass of the dissolution solvent A is usually 1 part by mass or more and 20 parts by mass or less.

[0065] In the polymer solution preparation step, the temperature of the dissolving solvent A when dissolving the alicyclic structure-containing polymer is usually 15°C or higher and 35°C or lower.

[0066] In the polymer solution preparation step, the alicyclic structure-containing polymer may be dissolved in the dissolving solvent A with stirring, and the stirring time is usually from 0.5 hours to 10 hours.

[0067] Here, in the polymer solution preparation step, the polymer solution may be prepared by directly dissolving the molded body in the dissolving solvent A, or the polymer solution may be prepared by the following first to fourth steps.

[0068] [First Step] In the first step, the molded body is dissolved in a dissolving solvent B to obtain a solution.

[0069] The dissolving solvent B used in the first step is not particularly limited as long as it is a solvent that can dissolve the alicyclic structure-containing polymer in the molded product.

[0070] Examples of the dissolution solvent B include methylcyclohexane, cyclohexane, xylene, toluene, etc. Among these, cyclohexane and xylene are preferred, and cyclohexane is more preferred, as they can improve the filtration rate.

[0071] In the first step, the amount of the molded article added to 100 parts by mass of the dissolution solvent B is usually 1 part by mass or more and 20 parts by mass or less.

[0072] In the first step, the temperature of the dissolving solvent B when dissolving the molded body is usually 15°C or higher and 35°C or lower.

[0073] In the first step, dissolution of the molded body in the dissolving solvent B may be carried out with stirring, and the stirring time is usually from 0.5 hours to 10 hours.

[0074] [Second Step] In the second step, the solution obtained in the first step is mixed with a precipitation solvent to prepare a mixed solution, and a precipitate containing an alicyclic structure-containing polymer is precipitated.

[0075] The precipitating solvent used in the second step is not particularly limited as long as it is a solvent that can precipitate a precipitate containing an alicyclic structure-containing polymer. Here, the precipitating solvent is preferably a poor solvent for the alicyclic structure-containing polymer. If the precipitating solvent is a poor solvent for the alicyclic structure-containing polymer, the precipitate containing the alicyclic structure-containing polymer can be easily precipitated.

[0076] Examples of the precipitation solvent include ketones such as methyl ethyl ketone and acetone; alcohols such as isobutyl alcohol; etc. Among these, methyl ethyl ketone is preferred because it can further improve the purity of the resulting regenerated alicyclic structure-containing polymer.

[0077] The SP value of the precipitation solvent is 7 (cal / cm ３ ) １／２ It is preferable that the calorie content is 9 (cal / cm ３ ) １／２More preferably, it is 9.3 (cal / cm ３ ) １／２ More preferably, it is 12 (cal / cm ３ ) １／２ It is preferable that the calorie content is 9.9 (cal / cm ３ ) １／２ More preferably, it is 9.5 (cal / cm ３ ) １／２ When the SP value of the precipitation solvent is equal to or greater than the lower limit, the recoverability of the regenerated product can be further improved. On the other hand, when the SP value of the precipitation solvent is equal to or less than the upper limit, the purity of the obtained regenerated product of the alicyclic structure-containing polymer can be further improved.

[0078] In the second step, the SP value of the precipitating solvent is preferably larger than the SP value of the dissolving solvent B. If the SP value of the precipitating solvent is larger than the SP value of the dissolving solvent B, a precipitate containing an alicyclic structure-containing polymer can be easily precipitated. The difference between the SP value of the precipitating solvent and the SP value of the dissolving solvent B ("SP value of the precipitating solvent" - "SP value of the dissolving solvent B") is, for example, 0.3 (cal / cm ３ ) １／２ or more, and 0.6 (cal / cm ３ ) １／２ or more, 0.8 (cal / cm ３ ) １／２ or more, for example, 3.5 (cal / cm ３ ) １／２ 2.5 (cal / cm ３ ) １／２ It may be 1.5 (cal / cm ３ ) １／２ The following is also acceptable.

[0079] In the second step, the content of the precipitation solvent in the mixed solution is preferably 30% by mass or more, more preferably 55% by mass or more, and preferably 99% by mass or less, and more preferably 80% by mass or less. If the content of the precipitation solvent in the mixed solution is above the above lower limit, the recovery of the recycled product can be improved. On the other hand, if the content of the precipitation solvent in the mixed solution is below the above upper limit, the amount of the precipitation solvent used can be effectively reduced, and the productivity of the recycled alicyclic structure-containing polymer can be improved.

[0080] In the second step, the preparation of the mixed solution is not particularly limited as long as it is a method that allows the solution obtained in the first step to be mixed with the precipitation solvent, but it is preferably carried out by adding the solution obtained in the first step to the precipitation solvent. If the preparation of the mixed solution is carried out by adding the solution obtained in the first step to the precipitation solvent, the purity of the obtained regenerated product of the alicyclic structure-containing polymer can be further improved.

[0081] In the second step, the temperature of the mixed solution when precipitating the precipitate (hereinafter sometimes referred to as the "precipitation temperature") is preferably 15°C or higher, more preferably 20°C or higher, and preferably 50°C or lower, more preferably 35°C or lower. If the precipitation temperature is above the above lower limit, the purity of the obtained regenerated product of the alicyclic structure-containing polymer can be further improved. On the other hand, if the precipitation temperature is below the above upper limit, the recovery of the regenerated product and the removal of old additives can be further improved.

[0082] [Third Step] In the third step, the precipitation solvent is removed from the mixture obtained in the second step to obtain a precipitate.

[0083] The means for removing the precipitation solvent from the mixed solution is not particularly limited, and examples thereof include known means such as filtration, extraction, decantation, etc. Among these, it is preferable to remove the precipitation solvent by filtration. In this case, the precipitate can be obtained as a residue.

[0084] When removing the precipitation solvent by filtration, the filtration of the mixed solution may be carried out, for example, by pressure filtration or vacuum filtration. However, from the viewpoint of easily adjusting the differential pressure between the inlet and outlet of the filter and the filtration rate of the polymer solution, pressure filtration is preferred. Here, in pressure filtration, the differential pressure between the inlet and outlet of the filter is usually 0.1 MPa or more, preferably 0.15 MPa or more, and usually 1.0 MPa or less, preferably 0.5 MPa or less. If the differential pressure in pressure filtration is above the above lower limit, the filtration rate can be improved. On the other hand, if the differential pressure in pressure filtration is below the above upper limit, the load on the equipment can be reduced and the life of the equipment can be improved.

[0085] [Fourth Step] In the fourth step, the precipitate obtained in the third step is dissolved in a dissolution solvent A to obtain a polymer solution.

[0086] In the fourth step, the amount of the precipitate used is usually 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the dissolution solvent A.

[0087] In the fourth step, the temperature of the dissolving solvent A when dissolving the precipitate is usually 15°C or higher and 35°C or lower.

[0088] In the polymer solution preparation step, dissolution of the precipitate in the dissolution solvent A may be carried out with stirring, and the stirring time is usually from 0.5 hours to 10 hours.

[0089] In the first to fourth steps, it is preferable to use the same solvent as dissolving solvent A and dissolving solvent B from the viewpoint of operability.

[0090] <Heating Step> In the heating step, when the boiling point of the dissolving solvent A is Bp°C, the polymer solution is heated to a temperature of Bp°C or higher and Bp + 100°C or lower. This may make it easier to remove the second polymer as a residue. The heating step is not particularly limited as long as it can be heated to the above temperature range, but is usually carried out under pressure to heat at Bp°C or higher. The pressure (gauge pressure) in the heating step is preferably 0.1 MPa or higher and 0.3 MPa or lower. In the heating step, the system may be sealed using a sealed container or the like and placed under pressure.

[0091] The heating temperature in the heating step is Bp°C or higher, preferably Bp + 3°C or higher, and preferably Bp + 80°C or lower, Bp + 100°C or lower, more preferably Bp + 50°C or lower, and even more preferably Bp + 30°C or lower. If the heating temperature in the heating step is above the lower limit, the filtration rate can be improved. On the other hand, if the heating temperature in the heating step is below the upper limit, the purity of the regenerated alicyclic structure-containing polymer can be improved. In addition, the filtration rate can be improved.

[0092] Furthermore, the heating temperature in the heating step is preferably 80°C or higher, more preferably 83°C or higher, and preferably 180°C or lower, more preferably 140°C or lower, and even more preferably 100°C or lower. If the heating temperature in the heating step is above the lower limit, the filtration rate can be improved. On the other hand, if the heating temperature in the heating step is below the upper limit, the purity of the regenerated product of the alicyclic structure-containing polymer can be improved. Also, the filtration rate can be improved.

[0093] In the heating step, the heating time is usually 0.5 hours or more and 10 hours or less. In the heating step, the polymer solution may be heated while being stirred or while being left to stand, but it is preferable to heat the polymer solution while being stirred, as this can further improve the filtration rate.

[0094] <Cooling Step> In the cooling step, the polymer solution after the heating step is cooled. That is, the temperature of the polymer solution is made lower than the heating temperature in the heating step. This can make it easier to remove the second polymer as a residue.

[0095] The cooling temperature in the cooling step is preferably 40° C. or lower, and more preferably 30° C. or lower. If the cooling temperature in the cooling step is equal to or lower than the upper limit, the recoverability of the regenerated material can be improved. On the other hand, the cooling temperature in the cooling step is, for example, 0° C. or higher, or may be 10° C. or higher, or may be 20° C. or higher.

[0096] <Filtration step> In the filtration step, the polymer solution after the cooling step is filtered to obtain a filtrate containing an alicyclic structure-containing polymer. Here, the alicyclic structure-containing polymer contained in the filtrate can be used as the regenerated alicyclic structure-containing polymer, which is the target of the production method of the present invention. The temperature of the polymer solution in the filtration step is not particularly limited as long as it is a temperature at which a filtrate containing an alicyclic structure-containing polymer can be obtained, but is usually 20°C or higher and 40°C or lower.

[0097] In the filtration step, it is preferable to use a filter aid, which can improve the filtration rate. Examples of filter aids include diatomaceous earth (e.g., trade name "Radiolite") and perlite (e.g., trade name "Topco").

[0098] Here, examples of how to use the filter aid include the body feed method, in which the filter aid is added to a polymer solution in advance, and the pre-coating method, in which the filter aid is deposited on a filter material such as a filter to form a filter bed and then filtered.The pre-coating method is preferred because it can effectively prevent the filter aid powder from being mixed into the filtrate.Examples of the filter material include leaf filters with wire mesh, cloth filters (filter cloth), synthetic resin filters, paper filters, etc.

[0099] The filtration of the polymer solution may be carried out, for example, by pressure filtration or vacuum filtration, but it is preferable to carry out pressure filtration from the viewpoint of easily adjusting the differential pressure between the inlet and outlet of the filter and the filtration rate of the polymer solution. Here, in pressure filtration, the differential pressure between the inlet and outlet of the filter is usually 0.1 MPa or more, preferably 0.15 MPa or more, and usually 1.0 MPa or less, preferably 0.5 MPa or less. If the differential pressure in pressure filtration is above the above lower limit, the filtration rate can be improved. On the other hand, if the differential pressure in pressure filtration is below the above upper limit, the load on the equipment can be reduced and the life of the equipment can be improved.

[0100] <Precipitation Step> In the precipitation step, which can be optionally carried out, the filtrate obtained in the filtration step is mixed with a precipitation solvent to prepare a mixed liquid, and a precipitate containing the alicyclic structure-containing polymer is precipitated.

[0101] The deposition solvent used in the deposition step may be the same as the deposition solvent described in the "Second Step" section above.

[0102] Here, in the precipitation step, the SP value of the precipitation solvent is preferably larger than the SP value of the dissolution solvent A. If the SP value of the precipitation solvent is larger than the SP value of the dissolution solvent A, a precipitate containing an alicyclic structure-containing polymer can be easily precipitated. The difference between the SP value of the precipitation solvent and the SP value of the dissolution solvent A ("SP value of the precipitation solvent" - "SP value of the dissolution solvent A") is, for example, 0.3 (cal / cm ３ ) １／２ or more, and 0.6 (cal / cm ３ ) １／２ or more, 0.8 (cal / cm ３ ) １／２ or more, for example, 3.5 (cal / cm ３ ) １／２ 2.5 (cal / cm ３ ) １／２ It may be 1.5 (cal / cm ３ ) １／２ The following is also acceptable.

[0103] In the precipitation step, the content of the precipitation solvent in the mixed solution is preferably 30% by mass or more, more preferably 55% by mass or more, and preferably 99% by mass or less, and more preferably 80% by mass or less. If the content of the precipitation solvent in the mixed solution is above the above lower limit, the recovery of the recycled product can be improved. On the other hand, if the content of the precipitation solvent in the mixed solution is below the above upper limit, the amount of the precipitation solvent used can be effectively reduced, and the productivity of the recycled alicyclic structure-containing polymer can be improved.

[0104] In the precipitation step, the preparation of the mixed solution is not particularly limited as long as it is a method that can mix the filtrate and the precipitation solvent, but it is preferably carried out by adding the filtrate to the precipitation solvent. If the preparation of the mixed solution is carried out by adding the filtrate to the precipitation solvent, the purity of the obtained regenerated product of the alicyclic structure-containing polymer can be further improved.

[0105] In the precipitation step, the temperature of the mixed solution when precipitating the precipitate (precipitation temperature) is preferably 15° C. or higher, more preferably 20° C. or higher, and preferably 50° C. or lower, more preferably 35° C. or lower. If the precipitation temperature is above the lower limit, the purity of the obtained regenerated product of the alicyclic structure-containing polymer can be further improved. On the other hand, if the precipitation temperature is below the upper limit, the recovery of the regenerated product and the removal of old additives can be further improved.

[0106] <Precipitation Solvent Removal Step> In the precipitation solvent removal step, which can be optionally performed, the precipitation solvent is removed from the mixed liquid after the precipitation step to obtain a precipitate.

[0107] The means for removing the precipitation solvent from the mixed solution is not particularly limited, and examples thereof include known means such as filtration, extraction, decantation, etc. Among these, it is preferable to remove the precipitation solvent by filtration. In this case, the precipitate can be obtained as a residue.

[0108] When removing the precipitation solvent by filtration, the filtration of the mixed solution may be carried out, for example, by pressure filtration or vacuum filtration. However, from the viewpoint of easily adjusting the differential pressure between the inlet and outlet of the filter and the filtration rate of the polymer solution, pressure filtration is preferred. Here, in pressure filtration, the differential pressure between the inlet and outlet of the filter is usually 0.1 MPa or more, preferably 0.15 MPa or more, and usually 1.0 MPa or less, preferably 0.5 MPa or less. If the differential pressure in pressure filtration is above the above lower limit, the filtration rate can be improved. On the other hand, if the differential pressure in pressure filtration is below the above upper limit, the load on the equipment can be reduced and the life of the equipment can be improved.

[0109] <New additive addition step> In the new additive addition step, which can be optionally performed, a new additive (hereinafter sometimes referred to as "new additive") is added to the filtrate obtained in the filtration step, or the precipitate obtained in the optional precipitation solvent removal step is dissolved in a solvent, and the new additive is added to the obtained solution to obtain a new additive-containing solution. Note that the solvent that can be used in the new additive addition step may be the same solvent as the dissolution solvent A described in the above section "Polymer solution preparation step".

[0110] The new additives can be appropriately selected depending on the application of the recycled alicyclic structure-containing polymer, and examples thereof include additives such as antioxidants, ultraviolet absorbers, light stabilizers, near-infrared absorbers, colorants such as dyes and pigments, lubricants, plasticizers, antistatic agents, and fluorescent brighteners.

[0111] <Drying step> In the drying step, which can be optionally carried out, the filtrate obtained in the filtration step, the precipitate obtained in the precipitation solvent removal step, or the new additive-containing solution obtained in the new additive addition step is dried. That is, in the drying step, the solvent contained in the filtrate, precipitate, or new additive-containing solution is removed to obtain a dried regenerated alicyclic structure-containing polymer.

[0112] The drying in the drying step may be carried out by, for example, heat drying or vacuum drying. Alternatively, heat drying and vacuum drying may be combined to carry out heat drying under reduced pressure. From the viewpoint of the solvent removal rate, it is preferable to carry out heat drying under reduced pressure. The temperature at which heat drying or heat drying under reduced pressure is carried out is not particularly limited as long as the solvent can be removed, but is usually 150°C or higher, preferably 180°C or higher, and usually 300°C or lower, preferably 250°C or lower. The pressure at which vacuum drying or heat drying under reduced pressure is carried out is usually -0.01 MPa or lower, preferably -0.05 MPa or lower, and more preferably -0.1 MPa or lower, in terms of gauge pressure.

[0113] <Recycled Product of Alicyclic Structure-Containing Polymer> The recycled product of the alicyclic structure-containing polymer obtained by the production method of the present invention has the second polymer, any third polymer, and old additives removed (in other words, has high purity), and therefore can be suitably used as a raw material for recycled molded articles. Note that it is presumed that the third polymer is removed in the polymer solution preparation step, the precipitation step, and the precipitation solvent removal step when the method includes steps 1 to 4.

[0114] Here, the recycled product of the alicyclic structure-containing polymer can be optionally mixed with a polymer other than the alicyclic structure-containing polymer and used as a raw material for the recycled molded product.Specific molded products include molded products for optical applications such as lenses, prisms, optical films, optical sheets, optical disk substrates, light guide plates, light guides, optical fibers, and mirrors; molded products for medical applications such as disposable syringes, drug solution vials, drug packaging films, medical device storage containers, test cells, test containers, infusion bags, and syringe rods; molded products for electrical or electronic applications such as sheets, films, plate materials, containers, and insulating materials for electric wire coatings, wafer shippers, capacitor films, circuit boards, and connectors; pipes, round bars, bottles, building materials, and stationery.

[0115] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to these examples. In the following examples and comparative examples, parts and percentages are by mass unless otherwise specified. In the examples and comparative examples, measurements and evaluations were performed by the following methods.

[0116] <Filtration rate measurement> First, a 1.2 kg / m 3 filter aid (Radiolite (registered trademark) #1500 manufactured by Showa Chemical Industry Co., Ltd.) was placed on the filter of a filter (manufactured by SARTORIUS). ２ Next, 3 parts of a filter aid (Radiolite (registered trademark) #1500 manufactured by Showa Chemical Industry Co., Ltd.) was added to 100 parts of the molded body to the polymer solution obtained after the cooling step in the Examples and Comparative Examples (body feed). Then, using the above filter, a filter bed with a filtration area of ​​12.56 cm was formed. ２ The polymer solution containing the filter aid was subjected to pressure filtration at a pressure of 0.2 MPa, and the amount of filtrate obtained in 10 minutes was measured, and the filtration rate was evaluated according to the following criteria. The larger the amount of filtrate obtained, the better the filtration rate. A: 80 g or more B: 40 g or more but less than 80 g C: Less than 40 g

[0117] <Old Additive Removal Ability> Approximately 0.25 g of the precipitate obtained in the precipitation solvent removal step or the third step of the polymer solution preparation step in the Examples and Comparative Examples was weighed into a 25 mL volumetric flask, and approximately 2.5 mL of cyclohexane was added and the mixture was left standing overnight to dissolve. After adding 2-3 mL of chloroform as a compatibilizer, acetonitrile was added with thorough stirring to solidify (to a constant volume of 25 mL). The supernatant was filtered through a 0.2 μm syringe filter to obtain a test solution, and the amount of residual antioxidant was measured using liquid chromatography (Agilent, product name "1260 Infinity II LC"). The antioxidant removal rate was then calculated using the following formula (1), and the old additive removability was evaluated according to the following criteria. A higher antioxidant removal rate indicates better old additive removal ability. The amount of residual antioxidant was calculated by creating a calibration curve based on the peak areas of five samples with known antioxidant concentrations. Antioxidant removal rate [%] = (antioxidant used amount [g] - antioxidant remaining amount [g] / antioxidant used amount × 100 (1) A: 85% or more B: 80% or more but less than 85% C: 70% or more but less than 80% D: 70% or less

[0118] <Recycled Product Recovery> The yield of the recycled product of the alicyclic structure-containing polymer obtained in the examples and comparative examples was calculated using the following formula (2), and the recycled product recovery was evaluated according to the following criteria. A higher yield of the recycled product of the alicyclic structure-containing polymer means better recycled product recovery. Yield of recycled product of alicyclic structure-containing polymer [%] = recovered amount of recycled product of alicyclic structure-containing polymer [g] / amount of alicyclic structure-containing polymer used [g] × 100 (2) A: 70% or more B: 60% or more and less than 70% C: 50% or more and less than 60% D: less than 50%

[0119] <Haze (Purity)> 5 g of the alicyclic structure-containing polymer regenerated product obtained in the Examples and Comparative Examples was weighed into a 100 mL eye bottle, 45 g of cyclohexane was added, and the mixture was heated to 70°C to dissolve the alicyclic structure-containing polymer regenerated product, thereby obtaining a sample solution. The obtained sample solution was placed in a 1 cm thick quartz cell, and the haze was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH 7000SP") and evaluated according to the following criteria. Since the alicyclic structure-containing polymer used in the Examples and Comparative Examples has a low haze (less than 1%), the lower the haze of the sample solution, the higher the purity of the alicyclic structure-containing polymer regenerated product. Note that zero-point correction was performed using a 1 cm thick quartz cell filled with cyclohexane. A: Less than 1% B: 1% or more but less than 3% C: 3% or more but less than 10% D: 10% or more

[0120] (Example 1) <Preparation of Molded Product> A polymer having an alicyclic structure, which is a first polymer, was prepared using tricyclo[4.3.0.1 ２，５ ]deca-3,7-diene (trivial name: dicyclopentadiene) 85 parts, 8-ethyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ A copolymer (amorphous, Mw: 29,000, Tg: 98°C) obtained from 15 parts of tetrahydrofuran-3-ene (common name: ethyltetracyclododecene (ETD)) and 15 parts of methyl tetrahydrofuran (MTF) was kneaded with polypropylene (crystalline, manufactured by Japan Polypropylene Corporation, product name "Novatec PP," crystallization temperature: 130°C) as a second polymer and an antioxidant (manufactured by Koyo Research Institute Co., Ltd., product name "GLS1010"), and a molded body was produced using this mixture.

[0121] Cyclohexane as dissolution solvent A (SP value: 8.2 (cal / cm ３ ) １／２ To a vessel containing 90 parts of a polymer (polymerizable copolymer having a freezing point of 6.5°C and a boiling point of 81.4°C), 10 parts of the molded product obtained above (concentration: 10%) was added, and the vessel was sealed. The mixture was stirred at 25°C for 6 hours to dissolve the molded product, thereby obtaining a polymer solution.

[0122] <Heating Step> The obtained polymer solution was heated to 85°C and stirred at this temperature for 1 hour.

[0123] <Cooling Step> The polymer solution after the heating step was cooled to 25° C. The filtration rate of the obtained polymer solution after the cooling step was evaluated. The results are shown in Table 1.

[0124] <Filtration step> A filter bed consisting of a filter aid ("Radiolite (registered trademark) #1500" manufactured by Showa Chemical Industry Co., Ltd.) was formed on the filter of a filter (manufactured by SARTORIUS) (precoat). Next, 3 parts of a filter aid ("Radiolite (registered trademark) #1500" manufactured by Showa Chemical Industry Co., Ltd.) was added to the polymer solution after the cooling step per 100 parts of the molded body. Then, using the filter, pressure filtration of the polymer solution containing the filter aid was performed at a pressure of 0.2 MPa, and polypropylene was removed to obtain a colorless and transparent solution (filtrate).

[0125] <Precipitation Step> A container was charged with 100 parts of the filtrate and 100 parts of methyl ethyl ketone (SP value: 9.3 (cal / cm)) as a precipitation solvent. ３ ) １／２ The filtrate was added slowly at a rate of 3 g / min to methyl ethyl ketone in the vessel at a temperature of 300 parts of a solvent for precipitation (freezing point: -86°C, boiling point: 79.6°C), and a mixture containing 75% of the solvent for precipitation was prepared, and a precipitate containing an alicyclic-containing polymer was precipitated. The precipitation temperature was 25°C.

[0126] <Precipitation Solvent Removal Step> Using a filter (manufactured by SARTORIUS), the mixed solution containing the precipitate was subjected to pressure filtration at a pressure of 0.2 MPa to remove the precipitation solvent and obtain a precipitate (filtrate). The obtained filtrate was used to evaluate the removability of the old additive. The results are shown in Table 1.

[0127] <New additive addition step> 10 parts (concentration 10%) of the precipitate (filtered residue) obtained above was added to 90 parts of cyclohexane as a solvent, and the precipitate was dissolved by stirring at 25°C for 6 hours to obtain a solution. To the obtained solution, 0.4 parts of an antioxidant (manufactured by Koyo Research Institute Co., Ltd., product name "GLS1010") as a new additive was added per 100 parts of the filtered residue to obtain a new additive-containing solution.

[0128] <Drying step> The solvent cyclohexane and other volatile components were removed from the new additive-containing solution obtained above using a high-temperature vacuum dryer (manufactured by Yamato Scientific Co., Ltd.) at a temperature of 200°C and a pressure of -0.1 MPa (gauge pressure), thereby obtaining a recycled product of the alicyclic structure-containing polymer. The obtained recycled product of the alicyclic structure-containing polymer was used to evaluate the recoverability and purity of the recycled product. The results are shown in Table 1.

[0129] (Example 2) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in the precipitation step, the content of the precipitation solvent in the mixed solution was adjusted to 50%. The results are shown in Table 1.

[0130] (Example 3) In producing a molded body, a cyclic olefin copolymer (amorphous, manufactured by Mitsui Chemicals, Inc., product name "APEL5014CL") as the alicyclic structure-containing polymer, which is the first polymer, polypropylene as the second polymer, and 0.4 parts of an antioxidant (manufactured by Koyo Research Institute Co., Ltd., product name "GLS1010") were kneaded to obtain a molded body. Various operations, measurements, and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

[0131] (Example 4) In producing a molded body, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that the second polymer was changed from polypropylene to polyethylene (crystalline, manufactured by Japan Polyethylene Corporation, product name "Novatec HD", crystallization temperature: 130°C). The results are shown in Table 1.

[0132] (Example 5) Various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that the dissolving solvent A in the polymer solution preparation step was changed from cyclohexane to xylene (boiling point: 138° C.) and the heating temperature in the heating step was changed from 85° C. to 150° C. The results are shown in Table 1.

[0133] (Example 6) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the following first to fourth steps were carried out in the polymer solution preparation step, and that the precipitation step and the precipitation solvent removal step were not carried out, and instead 0.4 parts of an antioxidant per 100 parts of the molded article used in the first step below was directly added to the filtrate obtained in the filtration step, thereby carrying out a new additive addition step. The results are shown in Table 1.

[0134] <First Step> Cyclohexane as dissolution solvent B (SP value: 8.2 (cal / cm ３ ) １／２ To a vessel containing 90 parts of toluene (freezing point: 6.5°C, boiling point: 81.4°C), 10 parts of the molded product (concentration: 10%) was added, the vessel was sealed, and the mixture was stirred at 25°C for 6 hours to dissolve the molded product, thereby obtaining a solution containing the molded product.

[0135] <Second Step> A container was charged with 100 parts of the filtrate and 100 parts of methyl ethyl ketone (SP value: 9.3 (cal / cm)) as a precipitation solvent. ３ ) １／２ The filtrate was added slowly at a rate of 3 g / min to methyl ethyl ketone in the vessel at a temperature of 300 parts of a solvent for precipitation (freezing point -86°C, boiling point 79.6°C), and a mixture containing 75% of the solvent for precipitation was prepared, and a precipitate containing an alicyclic-containing polymer was precipitated. The precipitation temperature was 25°C.

[0136] <Third Step> Using a filter (manufactured by SARTORIUS), the mixture containing the precipitate was subjected to pressure filtration at a pressure of 0.2 MPa, and the precipitation solvent was removed to obtain a precipitate (filtrate). The obtained filtrate was used to evaluate the antioxidant removal ability. The results are shown in Table 1.

[0137] <Fourth Step> To 90 parts of cyclohexane as a dissolution solvent A, 10 parts (concentration: 10%) of the precipitate (filtered residue) obtained above was added, and the container was sealed. The mixture was stirred at 25°C for 6 hours to dissolve the precipitate, thereby obtaining a polymer solution.

[0138] Example 7 Various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that in the precipitation step, the content of the precipitation solvent in the mixed solution was adjusted to 25%. The results are shown in Table 1.

[0139] Example 8 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in the deposition step, the deposition temperature was changed from 25° C. to 70° C. The results are shown in Table 1.

[0140] Example 9 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in the deposition step, the deposition temperature was changed from 25° C. to 10° C. The results are shown in Table 1.

[0141] (Example 10) Various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that in the precipitation step, the filtrate was placed in a container and methyl ethyl ketone was added as a precipitation solvent to the filtrate in the container. The results are shown in Table 1.

[0142] Example 11 Except for changing the deposition solvent from methyl ethyl ketone to acetone in the deposition step, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0143] Example 12 Except for changing the deposition solvent from methyl ethyl ketone to toluene in the deposition step, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0144] Example 13 Except for changing the deposition solvent from methyl ethyl ketone to isopropyl alcohol in the deposition step, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0145] Example 14 Except for not carrying out the precipitation step and the precipitation solvent removal step, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0146] Comparative Example 1 Various operations, measurements and evaluations were carried out in the same manner as in Example 1, except that in the heating step, the heating temperature was changed from 85° C. to 185° C. The results are shown in Table 1.

[0147] Comparative Example 2 Various operations, measurements and evaluations were carried out in the same manner as in Example 1, except that in the heating step, the heating temperature was changed from 85° C. to 70° C. The results are shown in Table 1.

[0148] In Table 1 below, "Polymer A" represents a copolymer obtained from dicyclopentadiene and ethyltetracyclododecene, "Polymer B" represents a cyclic olefin copolymer (product name "APEL5014CL"), which is an alicyclic structure-containing polymer manufactured by Mitsui Chemicals, Inc., "PP" represents polypropylene, "PE" represents polyethylene, "CHA" represents cyclohexane, "XY" represents xylene, "MEK" represents methyl ethyl ketone, "AC" represents acetone, "TL" represents toluene, and "IPA" represents isopropyl alcohol. "SP value" represents the solubility parameter, "filtrate → precipitation solvent" represents that the filtrate was added to the precipitation solvent in a container to obtain a mixed solution in the precipitation step, and "precipitation solvent → filtrate" represents that the precipitation solvent was added to the filtrate in a container to obtain a mixed solution in the precipitation step.

[0149]

[0150] As is clear from Table 1, Examples 1 to 14 are excellent in filtration rate.

[0151] According to the present invention, a method for producing a regenerated product of an alicyclic structure-containing polymer having an excellent filtration rate can be provided.

Claims

1. A method for producing a recycled product of a polymer having an alicyclic structure from a molded product containing a first polymer, that is, a polymer having an alicyclic structure, and a second polymer different from the first polymer, the method comprising: a polymer solution preparation step of using the molded product to obtain a polymer solution in which the polymer having an alicyclic structure is dissolved in a dissolving solvent A; a heating step of heating the polymer solution to a temperature of Bp°C or higher and Bp + 100°C or lower, where Bp°C is the boiling point of the dissolving solvent A; a cooling step of cooling the polymer solution after the heating step; and a filtration step of filtering the polymer solution after the cooling step to obtain a filtrate containing the polymer having an alicyclic structure.

2. A method for producing a regenerated product of a polymer having an alicyclic structure according to claim 1, further comprising: a precipitation step in which the filtrate obtained in the filtration step is mixed with a precipitation solvent to prepare a mixed liquid, and a precipitate containing the polymer having an alicyclic structure is precipitated; and a precipitation solvent removal step in which the precipitation solvent is removed from the mixed liquid after the precipitation step to obtain the precipitate.

3. The method for producing the regenerated product of the alicyclic structure-containing polymer according to claim 2, wherein the mixed solution is prepared by adding the filtrate to the precipitation solvent.

4. The method for producing a regenerated alicyclic structure-containing polymer according to claim 1, wherein the polymer solution preparation step comprises: a first step of dissolving the molded body in a dissolving solvent B to obtain a solution; a second step of mixing the solution obtained in the first step with a precipitating solvent to prepare a mixed liquid and precipitating a precipitate containing the alicyclic structure-containing polymer; a third step of removing the precipitating solvent from the mixed liquid after the second step to obtain the precipitate; and a fourth step of dissolving the precipitate obtained in the third step in the dissolving solvent A to obtain the polymer solution.

5. The solubility parameter of the precipitation solvent is 7 (cal / cm ３ ) １／２ More than 9.9 (cal / cm ３ ) １／２ The method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of claims 2 to 4, wherein:

6. A method for producing a regenerated product of a polymer containing an alicyclic structure according to any one of claims 2 to 4, wherein the content of the precipitation solvent in the mixed liquid is 30% by mass or more and 99% by mass or less.

7. A method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of claims 2 to 4, wherein the temperature at which the precipitate is precipitated is 15°C or higher and 50°C or lower.

8. A method for producing a regenerated product of an alicyclic structure-containing polymer according to any one of claims 1 to 4, wherein the cooling temperature in the cooling step is 40°C or lower.

9. A method for producing a regenerated product of a polymer having an alicyclic structure according to any one of claims 1 to 4, wherein the polymer having an alicyclic structure is amorphous and the second polymer is crystalline.

10. A method for producing a recycled product of a polymer containing an alicyclic structure according to any one of claims 1 to 4, wherein the heating temperature in the heating step is 80°C or higher and 140°C or lower.

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