JP2008303268A - Polyether-based polymer pellet, and classification method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyether-based polymer of high quality, and a classification method enhancing classification precision and productivity. <P>SOLUTION: The number of particles having 100 mg or less of mass is 99% or more with respect to total particle number, in this polyether-based polymer pellets of the present invention. The polyether polymer pellets is high in its quality. The high quality of pellets is obtained by classification. Multi-stage classification passing the pellets through a screen having at least one kind of sieve opening at two stages or more is carried out in this classification method of the present invention for obtaining the polyether-based polymer pellets. The screen comprises preferably punching metal, in the classification method. Recycle classification is preferably carried out to reclassify the pellets not having passed through the screen in the final stage in the multi-stage classification, together with the unclassified pellets. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyether polymer pellet.

  Polyether polymer resins are used in various fields. Examples of typical polyether polymer resins include ethylene oxide-butylene oxide copolymers. This polyether-based polymer resin has various functionalities such as surfactants, sanitary products, deinking agents, lubricating oils, hydraulic oils, polymer electrolytes, battery materials, flexographic printing plates, and protective films for color filters. Used for materials.

  This polyether polymer resin is usually used after being pelletized. For example, the pellets are supplied to a screw feeder or the like and extruded to be used.

Japanese Patent Application Laid-Open Nos. 2005-231253 and 2006-335905 disclose a method for producing a polyether polymer pellet. In these documents, a method of obtaining square pellets by cutting a sheet obtained by cooling and solidifying a polyether polymer is disclosed.
JP-A-2005-231253 JP 2006-335905 A

  The particle size distribution of the pellet is important as the quality of the pellet. For example, when long pellets are mixed, clogging of a screw feeder or the like may occur due to the pellets. Moreover, mixing of long pellets may deteriorate the dimensional accuracy of the molded product.

  Since the polyether polymer has a low melting point, the slipperiness is poor. Polyether polymers tend to generate heat when cut. Furthermore, since the polyether polymer is water-soluble, it cannot be immersed in water and cooled with water. Polyether polymers that are poorly slidable and tend to generate heat are difficult to cut stably. Therefore, it is difficult for the polyether polymer pellets to improve the accuracy of the particle size distribution by the cutting process. If cut at a low speed, heat generation can be suppressed, but productivity decreases. It has been difficult to obtain polyether polymer pellets with high productivity and high accuracy.

  In the present invention, the usefulness of a polyether polymer pellet having a highly accurate particle size distribution was found. In another aspect of the present invention, it was found that pellets can be obtained with high accuracy and high productivity by classifying the pellets obtained by the cutting step. In the present invention, a more effective classification method has been found.

  An object of the present invention is to provide a polyether polymer pellet having a highly accurate particle size distribution.

  In the polyether polymer pellet according to the present invention, the number of particles having a mass of 100 mg or less is 99% or more based on the total number of particles.

  Another aspect of the present invention performs multi-stage classification in which a screen having at least one kind of openings is passed through two or more stages, and by this multi-stage classification, the number of particles having a mass of 100 mg or less is based on the total number of particles. This is a classification method for obtaining polyether polymer pellets of 99% or more. In this classification method, preferably, the screen is a punching metal. Punching metal can contribute to improvement of classification accuracy.

  Still another aspect of the present invention performs multi-stage classification in which a screen having at least one kind of openings is passed through two or more stages, and pellets that have not passed through the screen in the final stage of the multi-stage classification are unclassified pellets. In addition, the classification method is used to obtain polyether polymer pellets in which the number of particles having a mass of 100 mg or less is 99% or more with respect to the total number of particles by being subjected to reclassification.

  High quality polyether polymer pellets can be obtained.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  The polyether polymer pellet according to the present invention comprises a polymerization step for obtaining a polyether polymer by polymerizing one or two or more monomers, and a composition using the polyether polymer as a base resin. A molding process for forming an article into a sheet, a cutting process for cutting the sheet into pellets, and a classification process for classifying the pellets by multistage classification in which at least one screen having at least one kind of openings is passed. It can manufacture by the manufacturing method containing these. By this production method, polyether polymer pellets in which the number of particles having a mass of 100 mg or less is 99% or more based on the total number of particles can be obtained. Below, each process is demonstrated one by one.

[Polyether polymer and polymerization process thereof]
The base resin of the pellet according to the present invention is a polyether polymer. In this application, a polyether polymer pellet is a pellet which consists of a resin composition which uses a polyether polymer as base resin. This polyether polymer is obtained by polymerizing one or more monomers. This monomer is an oxirane compound which may have a substituent.

  The oxirane compound which may have a substituent is, for example, a compound represented by the following structural formula (1).

In the formula (1), R ¹ , R ² , R ³ and R ⁴ are each a compound represented by Ra or —CH ₂ —O—Re—Ra group. The Ra is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, an aralkyl group having 1 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms. A (meth) acryloyl group, a C1-C20 alkenyl group, or a C1-C20 alkaryl group is represented. In the formula (1), any two substituents selected from the group consisting of R ¹ , R ² , R ³ and R ⁴ may form a ring together with the epoxy carbon atom to which they are bonded. However, an epoxy carbon atom means the carbon atom which comprises an oxirane ring. In the formula (1), Re represents a structure of — (CH ₂ —CH ₂ —O) _p —, and p is an integer from 0 to 10. R ¹ , R ² , R ³ and R ⁴ may be the same as or different from each other.

  The polyether polymer according to the present invention is preferably a polyethylene oxide or ethylene oxide copolymer. This ethylene oxide copolymer is a polymer obtained by polymerizing a monomer mixture containing ethylene oxide and a substituted oxirane compound represented by the following structural formula (2) as essential raw materials.

In the formula (2), R ⁵ represents Rb or a —CH ₂ —O—Re—Rb group. Rb is an alkyl group having 1 to 16 carbon atoms, a cycloalkyl group having 1 to 16 carbon atoms, an aryl group having 1 to 16 carbon atoms, an aralkyl group having 1 to 16 carbon atoms, and a (meth) acryloyl group having 1 to 16 carbon atoms. Group or an alkenyl group having 1 to 16 carbon atoms. Re has a structure of — (CH ₂ —CH ₂ —O) _p —, and p is an integer from 0 to 10.

The R ⁵ group in the structural formula (2) is a substituent in the substituted oxirane compound.

  The substituted oxirane compound used as the raw material monomer may be only one type of substituted oxirane compound that can be represented by the above structural formula (2), or may contain two or more types. Furthermore, the raw material monomer according to the present invention may be an oxirane compound which may have a substituent.

Examples of the substituted oxirane compound represented by the structural formula (2) include propylene oxide, butylene oxide, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyoctane, cyclohexene oxide, and styrene oxide. And methyl glycidyl ether, ethyl glycidyl ether, and ethylene glycol methyl glycidyl ether. In particular, when the substituent R ⁵ is a crosslinkable substituent, examples of the substituted oxirane compound represented by the structural formula (2) include epoxybutene, 3,4-epoxy-1-pentene, and 1,2-epoxy-5. , 9-cyclododecadiene, 3,4-epoxy-1-vinylcyclohexene, 1,2-epoxy-5-cyclooctene, glycidyl acrylate, glycidyl methacrylate, glycidyl sorbate and glycidyl-4-hexanoate, or Vinyl glycidyl ether, allyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, α-terpenyl glycidyl ether, cyclohexenyl methyl glycidyl ether, 4-vinylbenzyl glycidyl ether, 4-allylbenzyl glycidyl ether, ethylene glycol allyl glycidyl Examples include ether, ethylene glycol vinyl glycidyl ether, diethylene glycol allyl glycidyl ether, diethylene glycol vinyl glycidyl ether, triethylene glycol allyl glycidyl ether, triethylene glycol vinyl glycidyl ether, oligoethylene glycol allyl glycidyl ether and oligoethylene glycol vinyl glycidyl ether. it can.

  The monomer mixture used in the present invention may contain not only the oxirane compound which may have the above substituents but also other monomers as a raw material monomer. The monomer mixture used in the present invention may contain the above alkylene oxide and the above substituted oxirane compound as a raw material monomer, and may further contain other monomers.

  In the case where ethylene oxide and a substituted oxirane compound are selected as raw material monomers, there are no particular limitations on the amounts of ethylene oxide and substituted oxirane compounds used in the monomer mixture. For example, the amount used is appropriately set to such an extent that the resulting alkylene oxide copolymer does not lose viscosity more than necessary and lacks practicality. Moreover, when the substituted oxirane compound which has a crosslinkable substituent is used, this substituted oxirane compound should just be used in arbitrary ratios with respect to the substituted oxirane compound whole quantity, and is not necessarily limited.

  Similarly, in the case where the monomer mixture contains other monomers than the above monomers, the amount of each monomer used should be set in consideration of the obtained polyether polymer. Good.

  For example, in the case of producing a flexible and tack-free film or sheet using the polyether-based polymer according to the present invention, as the suitable monomer, for example, the substituted oxirane compound may be butylene oxide, propylene oxide or Allyl glycidyl ether is preferred. Preferred polyether polymers in the present invention are, for example, ethylene oxide-butylene oxide copolymer, ethylene oxide-butylene oxide-allyl glycidyl ether copolymer, polyethylene oxide, ethylene oxide-propylene oxide copolymer, and the like.

  In the polymerization step of the polyether polymer, the monomer mixture is preferably polymerized while being stirred in a solvent. The polymerization method is not particularly limited, and preferred examples include a solution polymerization method and a precipitation polymerization method. The solution polymerization method is more preferable because it is excellent in productivity. A solution polymerization method in which polymerization is performed while supplying a raw material monomer to a solvent charged in advance is particularly preferable because of safety such as easy removal of reaction heat.

  Examples of the solvent include aromatic hydrocarbon solvents such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as heptane, octane, n-hexane, n-pentane, and 2,2,4-trimethylpentane. Solvents; cycloaliphatic hydrocarbon solvents such as cyclohexane and methylcyclohexane; ether solvents such as diethyl ether, dibutyl ether and methylbutyl ether; solvents of ethylene glycol dialkyl ethers such as dimethoxyethane; THF (tetrahydrofuran) An organic solvent that does not contain active hydrogen such as a hydroxyl group, such as cyclic ether solvents such as dioxane, and toluene and xylene are more preferable.

  The solvent is preferably the organic solvent and does not contain water at all. However, generally, the organic solvent often contains even a small amount of water unless a complete dehydration treatment is performed. Therefore, it is preferable to control the amount of water contained in the organic solvent to a certain amount or less by dehydration.

  At the time of the above polymerization, a conventional general-purpose reaction initiator (polymerization initiator), antioxidant, solubilizer, etc. may be added and used.

  The reaction initiator is not particularly limited. Specifically, for example, alkaline catalysts such as sodium hydroxide, potassium hydroxide, potassium alcoholate, sodium alcoholate, potassium carbonate, sodium carbonate; metals such as metal potassium and metal sodium Calcined aluminum hydroxide / magnesium (see JP-A-8-268919 etc.); metal ion-added magnesium oxide (see JP-B-6-15038, JP-A-7-227540, etc.); calcined hydrotalcite ( Al-Mg based composite oxide catalysts such as JP-A-2-71841) or catalysts obtained by surface modification thereof (JP-A-8-268919 etc.); barium oxide; barium hydroxide (JP (See Japanese Laid-Open Patent Publication No. 56-56232 etc.); Strontium oxide; strontium hydroxide (JP-B 63-32055, etc.); calcium compound (JP-A 2-134336, etc.); cesium compound (JP-A 7-70308, etc.); composite Preferred examples include metal cyanide complexes (JP-A-5-339361, etc.); acid catalysts such as Lewis acids and Friedel-Crafts catalysts. The said reaction initiator may be used independently and may use 2 or more types together as needed.

  By adjusting the use amount of the reaction initiator, the molecular weight of the obtained polymer can be adjusted. The amount used is not particularly limited as long as it is appropriately determined so that a polymer having a desired molecular weight can be obtained. For example, the amount used may be set based on the charged amount of the monomer mixture. Specifically, for example, it can be set to use 1 μmol or more of the reaction initiator per 1 g of the charged amount of the monomer mixture, but it is not limited at all. In general, when obtaining a high molecular weight polymer, it is necessary to reduce the amount of reaction initiator used, but if the amount used is too small, the progress of the polymerization reaction becomes extremely slow, which may impair productivity. In some cases, the polymerization reaction may not proceed because the reaction system becomes extremely sensitive to mixing of a polymerization inhibitor such as moisture. In order to obtain a high molecular weight polymer, for example, the amount of the reaction initiator used is adjusted, and polymerization inhibitors such as moisture and impurities are removed from the reaction system, and the chain transfer reaction described above is not caused. It is important to make such a reaction system.

  The method for adding the reaction initiator is not limited. The reaction initiator may be charged in total with the solvent in advance before starting to supply the monomer mixture to the solvent, or may be sequentially added (continuously added even after the monomer mixture starts to be supplied). And / or intermittent input). When the monomer mixture is polymerized using the reaction initiator, it is preferable to adjust the amount of water contained in the solvent in the reaction system. Specifically, when the monomer mixture is polymerized using a reaction initiator, the amount of water contained in the solvent at the start of the polymerization reaction is less than the amount of the reaction initiator contained in the solvent. The ratio is preferably 1 or less, more preferably 0.5 or less, still more preferably 0.3 or less, and most preferably 0. When the said molar ratio exceeds 1, there exists a possibility that the molecular weight of the polymer obtained may fall, and also there exists a possibility that a polymerization reaction may not advance. In particular, when toluene is used as a solvent, the influence of the amount of moisture is very large.

  As described above, the method for adjusting and controlling the amount of water in the solvent is not particularly limited. Specifically, for example, by a physical method such as dehydration by molecular sieve treatment and distillation purification, or a chemical reaction in which water is removed using a compound highly reactive with water such as sodium metal and alkylaluminum. And the like. In view of industrial practicality, the former physical method is more preferable, and more preferable methods are molecular sieve treatment and distillation purification. The kind of polymerization mechanism in each of the above polymerization methods (solution polymerization method, etc.) is not particularly limited, and preferred examples include anionic polymerization, cationic polymerization, coordination polymerization, and immortal polymerization. Among them, anionic polymerization can be obtained with high reproducibility because a highly pure one can be easily obtained industrially, and since the handling of the reaction initiator is easy and the molecular weight is relatively easy to adjust, More preferred.

  The reactor that can be used in the polymerization is usually a reactor that can be used when a polymer is obtained by a polymerization reaction. A reactor excellent in heat resistance, chemical resistance, corrosion resistance, heat removal property, pressure resistance, and the like is preferable, but the type is not particularly limited.

  The reactor is not particularly limited as long as it can stir the contents such as the charged solvent and the supplied monomer, and a reactor equipped with a stirring blade and capable of arbitrarily stirring the contents under desired conditions is preferable. The stirring blade is not particularly limited, and specifically, for example, a stirring tank equipped with an anchor blade, a stirring tank equipped with a helical ribbon blade, a stirring tank equipped with a double helical ribbon blade, a helical screw blade with a draft tube , A super-blend wing (inner wing: Max blend wing, outer wing: spiral deformed baffle) vertical concentric twin-shaft agitator (for example, product name: Super Blend, Sumitomo Heavy Industries, Ltd.) )), MaxBlend wing (Sumitomo Heavy Industries, Ltd.), stirring tank equipped with full zone wing (Shinko Environmental Solution), Supermix wing (Satake Chemical Machinery) Stirrer tank, Hi-F mixer (manufactured by Soken Chemical Co., Ltd.), stirrer tank equipped with Sun-Mera wing (Mitsubishi Heavy Industries, Ltd.) Stirrer tank equipped with Tec Corp., agitator tank equipped with VCR (Mitsubishi Heavy Industries Ltd.), twisted lattice blade (manufactured by Hitachi, Ltd.), turbine blade, paddle blade, fiddler blade, bull margin blade, propeller blade, etc. A mounted agitation tank or the like can be preferably exemplified.

  The reactor is preferably equipped with equipment that can heat and maintain the contents at the desired reaction temperature. Specific examples of the equipment that can be heated and maintained include a jacket, a coil, and an external circulation heat exchanger, but are not particularly limited thereto. In addition to the equipment related to stirring, heating and the like described above, the reactor is, for example, a baffle, a detection end of a thermometer, a pressure gauge, etc., a supply device that uniformly disperses the raw material in liquid or gas phase, a reactor / reaction tank Any of various equipment such as an internal cleaning device can be arbitrarily installed for the reason of performing the polymerization reaction efficiently.

  Before polymerizing the monomer, the reactor is washed with the above solvent and dried by heating. Further, the reactor is sufficiently replaced with an inert gas, or the reactor is evacuated and then used. It is preferred that As the inert gas, nitrogen gas, helium gas, argon gas and the like are preferable. The solvent and inert gas are preferably highly pure. This is because, for example, when a compound having active hydrogen such as water is mixed, it may cause polymerization inhibition or molecular weight reduction, and oxygen is mixed when ethylene oxide is used as a monomer. This is because the danger of explosion of ethylene oxide may increase.

  It is preferable to charge a solvent in the reactor first before the polymerization of the monomer after the above washing or the like. The amount of the solvent and the like may be appropriately adjusted in consideration of the desired physical properties and production amount of the polymer, and is not particularly limited.

  It is preferable to replace the inside of the reactor again with an inert gas or to make the inside of the reactor in a reduced pressure state, preferably in a vacuum state before carrying out the polymerization reaction after charging the solvent or the like. When the polymerization is performed in an atmosphere substituted with an inert gas, it is preferable that the inert gas has a certain ratio or more in the gas phase portion in the reactor. At this time, it is preferable to adjust the internal pressure (initial pressure) of the reactor with an inert gas at the same time. The internal pressure (initial pressure) of the reactor is not particularly limited. For example, when ethylene oxide is used as the monomer, the initial pressure may be appropriately adjusted in consideration of the amount of ethylene oxide present in the reactor and managing safety.

  The polymerization is preferably performed while stirring the monomer together with the solvent. For this stirring, it is preferable to stir the contents such as the solvent in the reactor before supplying the monomer to the solvent by rotating a stirring blade mounted on the reactor. Stirring may be started from the start of supply or the start of polymerization, and the timing of starting stirring is not particularly limited. Further, stirring is preferably continued until the polymerization reaction is completed.

The stirring is preferably performed by controlling the number of revolutions of the stirring blade so that the stirring power becomes 0.6 kW / m ³ or more. The stirring power is more preferably 1 kW / m ³ or more, and more preferably 2 kW / m ³ or more. The stirring power is preferably controlled until the polymerization is completed, including when the monomer is supplied.

  Here, in general, the stirring power is a value calculated as the power required for stirring, which is conventionally known technical common sense. The stirring power is a required power per unit liquid amount of the contents in the reactor. This stirring power is calculated from the volume and viscosity of the contents, the shape of the reactor, the shape of the stirring blade, the rotational speed, and the like. The stirring power can be defined so as to satisfy the above range with respect to a reaction product (hereinafter also referred to as a reaction mixture) at the completion of the polymerization reaction. Therefore, the stirring power that satisfies the above range may not be ensured in the entire reaction system from the start to the end of the polymerization reaction.

  The method for making the stirring power satisfy the above range when the polymerization reaction is completed is not particularly limited. For example, the number of stirring revolutions required at the completion of the polymerization reaction is calculated from the viscosity of the reaction product at the completion of the polymerization, its capacity, and the shape of the stirring blade, and the stirring speed is constant from the start to the end of the polymerization reaction It is possible to adopt a method in which the reaction is carried out while maintaining the temperature. Here, the viscosity of the reaction product at the completion of the polymerization reaction is not particularly limited, but is appropriately set within a range of, for example, 200 to 2,000,000 centipoise in consideration of the type and amount of the monomer used. sell. The stirring rotation speed can be calculated based on the set viscosity.

When the stirring power is less than 0.6 kW / m ³ , the contents are not stirred uniformly, so the flow state in the reactor is deteriorated, the productivity of the polymer is lacking, and local heat storage is likely to occur, The temperature distribution of the reaction solution and the concentration distribution of monomers and the like are also non-uniform, which may cause abnormal reactions.

  The reaction temperature during the polymerization reaction is preferably adjusted and controlled as appropriate. The reaction temperature is more preferably adjusted and controlled in advance before supplying the monomer to the solvent and starting the polymerization, similarly to the adjustment of the reactor internal pressure. Specifically, it is preferable to control the so-called internal temperature so that the solvent or the like charged in the reactor has a desired reaction temperature in advance. This control of the reaction temperature is preferably applied until the polymerization is completed, including when the monomer is supplied.

  Although there is no limitation in particular about the said reaction temperature, it is preferable that it is 200 degrees C or less, More preferably, it is 180 degrees C or less, More preferably, it is 150 degrees C or less. In addition, the above reaction temperature is affected by the type of temperature adjustment equipment and the temperature change at the time of monomer supply. If the error is within ± 5 ° C. of the preferred temperature range, an excellent effect similar to the effect when there is no error can be obtained.

  When the reaction temperature is outside the above temperature range, various problems may occur in the molecular weight of the obtained polyether polymer. Specifically, when the reaction temperature is higher than the above-mentioned preferable range, the frequency of the chain transfer reaction is increased and the molecular weight is easily lowered, and in a remarkable case, it cannot be controlled by adjusting the addition amount of the reaction initiator. May reduce molecular weight.

  The reaction temperature is preferably kept constant until the end of the polymerization reaction. The reaction temperature can be arbitrarily changed within the above temperature range depending on the reaction operation, as the case may be or as necessary. The mode of changing the reaction temperature is not limited. Specifically, for example, in the case where the monomer is sequentially supplied and polymerized, the temperature is once set and controlled at the supply start stage, and then the polymerization reaction is started. After the internal temperature of the reaction system rises due to exotherm, the temperature after the rise is controlled as the set temperature. Here, making the reaction temperature constant means that the reaction temperature is controlled within a range of ± 5 ° C. around the desired reaction temperature.

  The reaction temperature may be adjusted and controlled by adjusting the temperature of the charged contents by heating the reactor or by directly heating the contents. There is no limitation. Preferred examples of equipment that can adjust the reaction temperature include, but are not limited to, a general-purpose jacket, a coil, and an external circulation heat exchanger.

  In the polymerization step, the solvent is charged into the reactor, and the above stirring power and reaction temperature are adjusted and controlled within a specific range, and then the monomer is supplied to the solvent and polymerized while stirring. Is preferred.

  The amount of the monomer used is not particularly limited. Specifically, for example, the concentration of the polyether polymer in the reaction product at the completion of the polymerization reaction (polymer concentration) exceeds 10% by mass. It may be sufficient, or may be a value exceeding 20% by mass. With respect to the amount of the monomer used, if the polymer concentration is 10% by mass or less, productivity may be low and practicality may be lacking.

  When the monomer is polymerized while stirring in the solvent, the monomer may be supplied to the solvent by supplying the entire amount of monomer by batch injection or by dividing the total amount of monomer. Then, each may be supplied by batch charging and polymerized, or may be polymerized while supplying at least a part of the monomer, and is not particularly limited.

  The case where the polymerization is performed while supplying at least a part of the monomer includes the case where the polymerization is performed while supplying at least a part of the monomer mixture by sequential charging.

  In the polymerization for supplying at least a part of the monomer, for example, a part of the total charge amount of the monomer mixture is supplied in advance to the solvent as an initial supply amount (initial charge amount), and the remaining amount is used. It includes polymerization that polymerizes while supplying, and also includes polymerization that polymerizes while supplying the entire amount of the monomer mixture.

  The sequential charging means continuous supply and / or intermittent supply. “Continuous supply” refers to continuous supply little by little, and “intermittent supply” refers to intermittent supply, for example, supplying in two or three times. To supply. The continuous supply is more preferable because the reaction temperature can be easily controlled to be constant. For the purpose of controlling the reaction temperature, the supply rate is preferably adjusted according to the type of copolymer raw material. Specifically, the feed rate is preferably adjusted in consideration of the reaction rate of the monomer used, the slow heating ability of the reactor used, the allowable pressure, and the like. Continuous supply and / or intermittent supply is intermittent supply as a whole, but continuous supply and intermittent supply, such as continuous supply at each intermittent supply. Including the combined supply.

  When the polymerization is performed while supplying at least a part of the monomer into the solvent, the supply rate may be constant until the end of the supply. For example, when a monomer mixture obtained by mixing a plurality of types of monomers is polymerized, the supply rate of at least one of essential raw materials (for example, ethylene oxide and substituted oxirane compounds) in the monomer mixture is increased. By varying it, the melting point of the polymer can be adjusted. The change in the supply speed may be, for example, a change that changes to any different speed at least once. In this case, the speed may be changed instantaneously (continuously), or may be continuously changed while changing the speed itself until it reaches the speed after the change, but may be temporarily supplied. It may be performed over a period of time that is not performed, and is not particularly limited. Similarly, the change in the supply speed may be, for example, an arbitrary change in the speed itself. In this case, the change speed of the speed itself may or may not be constant. There is no limitation. The change in the supply speed may be a combination of these various changes. The change in the supply rate is considered between the start and end of supply for each of the various monomers that are essential raw materials. When ethylene oxide is used as the monomer, in the situation where the viscosity is increased in the late stage of the reaction, it is difficult to absorb ethylene oxide in the liquid phase of the reaction system. Therefore, it is effective to slow the supply rate in the late stage of the reaction.

  Furthermore, in the production of a polyether polymer, a monomer mixture obtained by mixing a plurality of types of monomers is polymerized, and polymerization is performed while supplying at least a part of the monomer mixture into a solvent. In such a case, it is possible to increase the melting point of the polymer as much as possible by providing a period during which at least one of the essential raw materials (for example, ethylene oxide and substituted oxirane compounds) in the monomer mixture is not supplied. Can be adjusted. The period is from the start of the supply of at least one monomer contained in the monomer mixture to the end of the supply of all monomers contained in the monomer mixture; To do.

  Furthermore, when ethylene oxide and another monomer (monomer other than ethylene oxide) are used as monomers, a stage in which only ethylene oxide is supplied for polymerization and a stage in which ethylene oxide and other monomers are supplied for polymerization The monomers may be supplied so that each has at least one stage.

  In the production of the polyether-based polymer, it is preferable to age the reaction product in the reactor as necessary after the monomer supply is completed. The conditions for aging (temperature, time, etc.) are not particularly limited, and may be set as appropriate.

  At the time of decompression of the reactor after the above supply or aging, there may be a solvent or unreacted raw material monomer in the gas phase. Therefore, if necessary, a waste gas combustion device (for example, a combustion furnace, a combustion chamber) It is preferable to complete combustion with a catalyst. Further, steam (steam) can be obtained by recovering the heat generated at this time.

  If necessary, a solvent may be further added to the polyether polymer obtained after the above supply or after aging, and the polymer may be dissolved so as to have a desired viscosity and concentration. Although the solvent used in this case is not particularly limited, the solvent used in the polymerization is preferable. Moreover, you may add various stabilizers, solubilizers, etc., such as antioxidant, as needed with this solvent. Various stabilizers and solubilizers may be added after being mixed with the solvent, or may be added separately, and are not particularly limited.

  In the production of the polyether polymer, as described above, other than various processes such as a polymerization process in which a monomer is supplied to a solvent and polymerized while stirring, and an aging process in which a reaction product obtained in the polymerization process is aged. In addition, some other process may be provided. For example, following the polymerization step and the aging step performed as necessary, a part of the solvent component is volatilized under heating from the obtained reaction product to adjust the concentration of the polyether polymer solution (so-called A devolatilization step) may be provided.

[Volatilization process]
By performing the devolatilization treatment, purification / recovery by heat drying may be unnecessary. Moreover, the addition of an antistatic agent may be unnecessary by performing the devolatilization treatment. Furthermore, the water content of the polymer can be easily adjusted by devolatilization. When performing the devolatilization step, various stabilizers such as antioxidants and solubilizers may be added during the devolatilization step, or may be added and mixed after the devolatilization step. . In the devolatilization step, a solvent component (solvent used as a solvent) is volatilized from the reaction product to obtain a polyether polymer, but the obtained polyether polymer is limited to those containing no solvent component. Not. Usually, the solvent concentration of the reaction product after the polymerization step or the like is reduced to a desired solvent concentration by devolatilization.

  As a devolatilization method, an apparatus used for devolatilization, and various conditions, a method that can be employed during normal devolatilization, a usable apparatus, and set conditions may be adopted. Devolatilization is usually performed in two stages, pre-devolatilization and main-devolatilization. The devolatilization procedure is preferably performed after pre-devolatilization, but is not particularly limited. The devolatilization may be performed as a one-step process without distinguishing between pre-devolatilization and main devolatilization.

  The apparatus used for devolatilization (devolatilization apparatus) is not particularly limited, and the polymerized kettle may be used for devolatilization as it is. As a devolatilizer, for example, an agitation tank equipped with a helical blade, an agitation tank equipped with a double helical ribbon wing, a super blend wing with an inner wing that is a Max Blend wing and an outer wing that is a helically deformed baffle Type concentric twin-shaft stirred tank (for example, product name Super Blend manufactured by Sumitomo Heavy Industries, Ltd.), VCR reverse cone ribbon wing reactor (Mitsubishi Heavy Industries, Ltd.), etc. Stirred tank evaporator; multi-tube heat exchanger Downstream of the mold (for example, the product name Sulzer Mixer manufactured by Sumitomo Heavy Industries, Ltd. or the product name Static mixer manufactured by Noritake Co., Ltd.), the plate heat exchanger type (for example, the product name Hiviscos Evaporator manufactured by Mitsui Engineering & Shipbuilding Co., Ltd.) Liquid column evaporator; horizontal thin film evaporator (for example, Evariactor manufactured by Kansai Chemical Machinery Co., Ltd.), fixed blade type Type thin film evaporator (for example, product name EXEVA manufactured by Shinko Environmental Solution Co., Ltd.), movable blade type vertical thin film evaporator (for example, product name wiper manufactured by Shinko Environmental Solution Co., Ltd.), tank type (mirror type) thin film Thin film evaporators such as evaporators (for example, product name recovery manufactured by Kansai Chemical Machinery Manufacturing Co., Ltd.); single-axis surface renewable polymerizers, biaxial surface renewable polymerizers (for example, manufactured by Sumitomo Heavy Industries, Ltd.) Product name of Viola rack, product name manufactured by Hitachi, Ltd .: Hitachi spectacle blade polymerizer, product name manufactured by Hitachi, Ltd .: Hitachi lattice blade polymerizer, product name SC processor manufactured by Kurimoto Iron Works Co., Ltd.) Renewable polymerizer; Kneader; Roll mixer; Intensive mixer (so-called Banbury mixer); Single-screw extruder, twin-screw extruder (for example, product name SUP manufactured by Nippon Steel Works) Extruders such as ERTEXαII, product name BT-30-S2 manufactured by Plastic Engineering Laboratory, SCR self-cleaning reactor (manufactured by Mitsubishi Heavy Industries, Ltd.) and the like are preferably used, and at least one of these devices is used. It is preferable to carry out. Further, the use conditions can be appropriately set depending on the apparatus used.

  When performing the devolatilization step, the above-mentioned pre-stage to be used for the polymerization step or the like may be carried out by directly connecting the various devolatilization devices listed above to the so-called pre-stage device provided for the polymerization step or the aging step described above. Volatilization may be performed by various devolatilization apparatuses after liquid feeding or transfer from the apparatus. For the latter, for example, a form in which the space between the preceding device and the devolatilizer is connected by a liquid feed line, or an intermediate tank provided with a jacket and a stirrer between the preceding device and the devolatilizer The form etc. which provided the tank (cushion tank) are mentioned. In the devolatilization step, the residual solvent concentration in the reaction product after devolatilization is preferably 0.01 to 30% by mass, more preferably 0.05 to 20% by mass, and still more preferably 0.1. -10 mass%. When the residual solvent concentration is less than 0.01% by mass, it is necessary to make devolatilization conditions strict, which may lead to thermal degradation of the polyether-based polymer, and may ultimately cause performance degradation. When it exceeds mass%, tackiness may occur in the polyether polymer after devolatilization, and blocking or the like may occur.

  In the devolatilization step, it is preferable to adjust the water content of the reaction product after devolatilization simultaneously with the devolatilization of the solvent. The moisture is contained in, for example, the solvent or monomer used in the polymerization. Specifically, the water content of the reactant after devolatilization is preferably adjusted to 5,000 ppm or less, more preferably 500 ppm or less, and even more preferably 200 ppm or less. When the water content exceeds the above range, the dielectric constant of the polyether polymer becomes unnecessarily large.For example, when the polymer is used in application fields such as a protective film for a color filter, When the polymer becomes conductive, the protective film may cause a fatal functional deterioration. Further, when the water content exceeds the above range, the water may react with metal ions and the like to generate hydroxides and the like. Therefore, for example, when a polyether polymer whose water content exceeds the above range is used for an electrolyte layer of a polymer battery, an insulating layer is formed at the interface of the metal-electrolyte layer, and the voltage under a constant current increases. However, the cycle characteristics of the battery may be deteriorated.

  The means for adjusting the water content is not particularly limited. For example, it is preferable to increase the devolatilization temperature and / or increase the degree of vacuum during the devolatilization process. Increasing the degree of decompression means decreasing the pressure, and decreasing the degree of decompression means increasing the pressure. When adjusting the moisture content by increasing the devolatilization temperature, the temperature is not particularly limited. However, if the devolatilization temperature is too low, the degree of decompression must be increased excessively, which is not efficient. If the devolatilization temperature is too high, thermal degradation of the polyether polymer may occur. . Therefore, the devolatilization temperature is preferably set appropriately in consideration of these. Moreover, when adjusting the moisture content by increasing the degree of decompression for devolatilization, the degree of decompression is not particularly limited. However, if the degree of vacuum is too large, it is considered difficult considering the sealing performance of the devolatilizer, and if the degree of vacuum is too small, the moisture content may not be controlled to 200 ppm or less unless the devolatilization temperature is increased considerably. There is. Therefore, the degree of decompression is preferably set appropriately in consideration of these.

  By performing the devolatilization process, for example, the polyether polymer after the polymerization process is not recovered in a dry state by heating or the like, but can be recovered while keeping the fluid state by volatilizing the solvent component under heating. It becomes. Therefore, it is not necessary to consider the charging of the polymer caused by friction between the dried polymers, and there is no need to use an antistatic agent. When the resulting polyether polymer contains an antistatic agent, the dielectric constant of the polymer may be increased more than necessary, or the polymer may swell due to a decrease in the degree of crosslinking and an increase in hygroscopicity. There are cases where the magnification is increased more than necessary and the strength is lowered. Therefore, for example, when the obtained polyether polymer is used for a protective film of a color filter, the polymer may become conductive, which may cause a fatal functional deterioration as the protective film. There is. In addition, when the polymer is used for a flexographic printing plate or the like, it is difficult to maintain a desired shape and rebound resilience, which may result in poor image reproducibility. Furthermore, when the polymer is used for a separator, an electrode or an electrolyte layer of a polymer battery, there is a possibility that a desired shape cannot be maintained.

  When the solvent component is volatilized from the reaction product under heating using the devolatilizer described above, the temperature (devolatilization temperature) is preferably 40 to 300 ° C, more preferably 60 to 250 ° C, More preferably, it is 90-200 degreeC. By performing devolatilization within this temperature range, the reaction product having the desired residual solvent concentration and water content described above can be obtained after devolatilization. When the said temperature is less than 40 degreeC, there exists a possibility that the remaining solvent may increase, and when it exceeds 300 degreeC, there exists a possibility that polyether polymer itself may thermally decompose. Here, the said temperature is the temperature of the reaction material in a devolatilizer.

  The pressure at which the solvent component is volatilized from the reaction product under heating using the devolatilizer described above is preferably 13 to 100,000 Pa, more preferably 133 to 70,000 Pa, still more preferably 1, 333 to 40,000 Pa. By performing devolatilization in this pressure range, after the devolatilization, the above-described reactant having the desired residual solvent concentration and water content can be obtained. If the pressure is less than 13 Pa, the solvent may flash and foaming may occur. If the pressure exceeds 100,000 Pa, the temperature may have to be applied to the extent that the polyether polymer itself is decomposed. . The said pressure is the tank internal pressure of a devolatilizer.

  After devolatilization, the viscosity of the reaction product containing the polyether polymer is preferably 50 to 100,000 poise at 100 ° C., more preferably 100 to 80,000 poise at 100 ° C., and still more preferably 100 220 to 60,000 poise at ℃. When the viscosity is less than 50 poise at 100 ° C., the remaining solvent increases, and foaming and tacking may occur when molding with a polyether polymer as a material. If it exceeds 1, devolatilization with a devolatilizer may be difficult.

  The solvent removed by the devolatilization step may be recovered and reused in the step of solution polymerization of the solvent. Specifically, it is preferable to carry out a purification treatment by removing light and heavy components from the volatilized solvent, and after that, further dehydrated by, for example, passing through a dehydrating tower and reusing. The apparatus, conditions, etc. for performing the said refinement | purification process and a dehydration process are not specifically limited, What is necessary is just to select and employ | adopt a normal process apparatus, conditions, etc. suitably. Note that there is no problem with the above reuse even if the monomer component is contained in the solvent for purification and dehydration. This monomer component can be used for a polymerization reaction upon reuse.

[Addition process]
Various additives such as a stabilizer typified by an antioxidant may be added to the polyether polymer in a fluid state after devolatilization before the pelletizing step described later. That is, various additives are added to the polyether polymer solution during the polymerization process, after the polymerization process or during the devolatilization process, and / or after the devolatilization process, and mixed as necessary. Further, kneading or the like may be performed. Specifically, after obtaining a fluid-state polyether polymer by a devolatilization step, it is common to add various additives to the resin and mix them, but there is no particular limitation. For example, in the case of a small-scale production process, by adding various additives to the resin solution after the polymerization step and the resin solution in the middle of the devolatilization step, the addition step can be performed together with the devolatilization step. it can.

  Examples of the additive include an antioxidant (antioxidant), a heat stabilizer, a light stabilizer, an ultraviolet absorber, an antiseptic, a light resistance improver, and a plasticizer (dioctyl phthalate, low molecular weight polyether compound, etc.). , Fillers (carbon, glass fibers, inorganic fibers, etc.), surfactants (ethylene oxide nonionic active agents, etc.), lubricants (calcium stearate, etc.) and the like.

  In the addition step, in addition to the above additives, organic fine particles, inorganic fine particles, low molecular weight compounds, and the like can be added. The organic or inorganic fine particles can exhibit functions such as blocking prevention depending on the purpose and form of use of the polyether polymer. Examples of the organic fine particles include fine particles such as polystyrene, polyethylene, and polypropylene, and examples of the inorganic fine particles include inorganic oxides such as silica, alumina, titania, zirconia, and composite oxides thereof. Can do.

  Even additives that have already been added at the start of polymerization or polymerization reaction as a necessary component in the polyether polymer as the final product are reduced or removed in the devolatilization process, etc. Sometimes. In such a case, an appropriate amount of additive may be added again in the addition step.

  In the addition step, a kneader or the like is used when the added additive or the like needs to be mixed uniformly in the resin. As described above, when the addition step is performed together with the devolatilization step, usually, a mixing process is also performed in the devolatilization apparatus. Absent. However, when adding an additive etc. after a devolatilization process, in order to contain an additive etc. more uniformly, it is preferable to perform mixing processing, such as a kneading | mixing process.

  Examples of the kneading machine that can be used in the addition step include a product name “Static Mixer” manufactured by Noritake Co. and a product name “Sulzer Mixer” manufactured by Sulzer. Examples of the single-screw extruder that can be used in the addition step include a product name “GT series” manufactured by Plastic Engineering Laboratory. Examples of the twin-screw extruder or twin-screw kneader that can be used in the addition step include a kneader, a special kneader, and the like. Specifically, for example, a product name “S2KRC kneader” manufactured by Kurimoto Iron Works Co., Ltd. and Moriyama Manufacturing Co., Ltd. KRC kneaders such as the product name “Kneader Ruder” manufactured by the company are listed. In using these apparatuses, it is preferable that these apparatuses are connected to a polymerization tank, a resin melting tank or an apparatus for devolatilization through a polymer pump, a gear pump, or the like.

  The polyether polymer obtained through the solution polymerization step, the devolatilization step, and the addition step performed as necessary is finally pelletized. The polyether-based polymer after devolatilization is preferably cooled and solidified and formed into a shape that can be easily formed into pellets, and is subsequently pelletized in a cutting step. In general, the pellet is not particularly limited as long as it is granular enough to be distinguished from powder. Although the maximum diameter of the obtained pellet is not particularly limited, it is preferably 0.1 to 50 mm, and more preferably 1.0 to 30 mm.

[Cooling and solidification process]
The polyether polymer after the devolatilization step (hereinafter including the addition step) is in a fluid state and in a warm state. This polyether polymer is cooled and solidified. This cooling and solidifying step is also referred to as a cooling and solidifying step below. The cooling and solidifying step is not particularly limited, and for example, a step of bringing the polyether polymer in a fluid state after the devolatilizing step into contact with a metal surface and cooling and solidifying is preferable.

  Since the polyether polymer according to the present invention is water-soluble, it cannot be immersed in water and cooled with water. Moreover, since this polyether polymer has a low melting point, it often does not solidify at room temperature (25 ° C.). Therefore, it is preferable to cool and solidify by contacting the metal surface as described above.

  Examples of the metal surface that can be used in the cooling and solidifying step include a drum cooler (for example, a product name “COMACT CONTI COOLER” manufactured by Tsubako Co., Ltd., a product name “Drum Cooler DC” manufactured by Mitsubishi Chemical Engineering Co., Ltd.), and a modern machinery. Product name "Laminator" manufactured by Co., Ltd.), single belt cooler (eg, product name "Steel Belt Cooler" manufactured by Sandvik, product name "Steel Belt Single Cooler" manufactured by Nippon Steel Conveyor Co., Ltd.) And a cooling device such as a double belt cooler (for example, a product name “Double Steel Belt Cooler” manufactured by Sandvik Co., Ltd.), and a metal surface for cooling that can come into contact with the resin. The metal surface may be the surface of a metal plate or a non-plate-like metal surface. These cooling metal surfaces are cooled to a desired temperature, for example, by blowing a refrigerant from the back side. When double belt cooler, single belt cooler and drum cooler are used, the cooling belt, refrigerant temperature, refrigerant type selection, and selection of T-die width and drum and belt width, etc., fit the production volume Conditions can be easily obtained.

  The cooling temperature of the metal surface is preferably, for example, a crystallization temperature (Tc) and / or a temperature lower than the melting point of the fluidized polyether polymer after the devolatilization step.

  In the cooling and solidification process, usually, when any of the above cooling devices is used, the polyether-based polymer after the devolatilization process is discharged onto the metal surface and cooled and solidified while being conveyed on the metal surface. To do.

  A more preferable cooling and solidification step is to extrude the molten polyether polymer at a constant thickness while controlling the temperature, and contact with the metal surface maintained at a temperature equal to or lower than the crystallization temperature (Tc) of the polyether polymer. It is better to solidify. In order to increase the cooling efficiency, the polyether polymer is preferably extruded at a temperature of [Tc + 80] ° C. or lower.

  In order to peel the cooled polyether polymer from above the metal surface, a Teflon (registered trademark) sheet may be attached to the metal surface, or a Teflon (registered trademark) treatment or silicon treatment may be applied to the metal surface. May be applied.

  The metal surface is usually cooled by a refrigerant. Examples of this coolant include, but are not limited to, cooling air, water, ethylene glycol, and the like.

  From the viewpoint of increasing the cooling efficiency, the polyether polymer is preferably spread in a sheet shape on the metal surface. Therefore, it is preferable that the polyether polymer is formed into a sheet by being cooled and solidified.

  Generally, as a method for pelletizing the resin, a strand cut method is generally used in which the resin extruded from the die hole is passed through a cooling water bath and then cooled. However, as described above, the polyether polymer according to the present invention is water-soluble. Furthermore, since the polyether polymer according to the present invention has a low melting point, the strands extruded from the die holes stick to each other, which may make cutting difficult. Therefore, it is preferable that the pellet according to the present invention is processed into a sheet by cooling and then cut into a pellet.

[Cutting process]
In the cutting step, the cooled and solidified polyether polymer is cut into pellets. The polyether-based polymer formed into a sheet by cooling and solidification is preferably pelletized by vertical cutting and horizontal cutting. Longitudinal cutting is a process in which a polyether polymer sheet is cut at predetermined intervals to form an elongated shape. Cross-cutting is a process of cutting an elongated polyether polymer short by cutting in a direction perpendicular to the cutting direction of the vertical cutting. The polyether polymer is cut into a rectangular parallelepiped shape by a combination of vertical cutting and horizontal cutting. By this cutting, the sheet-like polyether polymer can be formed into pellets. This rectangular parallelepiped pellet is also referred to as a square pellet in the present application.

  In the following, an embodiment of a cutting apparatus that can be used in the cutting process will be described. FIG. 1 is a side view showing a schematic configuration of the cutting device (sheet pelletizer) 1. The cutting device 1 includes a roll cutter 3, a transverse rotary blade 5, and a fixed blade 7.

  The roll cutter 3 performs longitudinal cutting of the sheet. FIG. 2 is a view of the roll cutter 3 as viewed from above. The roll cutter 3 has two rotary blades 9 and 11. The rotary blade 9 has a disk-shaped blade portion 13 and a rotary shaft 14 provided at regular intervals in the direction of the rotation axis z1. The shape of the rotary blade 11 is the same as that of the rotary blade 9. That is, the rotary blade 11 has a disk-like blade portion 15 and a rotary shaft 16 provided at regular intervals in the direction of the rotation axis z2. The rotation axis z1 of the rotary blade 9 and the rotation axis z2 of the rotary blade 11 are parallel to each other. The rotation axis z1 and the rotation axis z2 are horizontal.

  As shown in FIG. 2, the rotary blade 9 and the rotary blade 11 are meshed with each other. The disk-shaped blade portions 13 of the rotary blade 9 and the disk-shaped blade portions 15 of the rotary blade 11 are alternately arranged. The disk-shaped blade portion 13 and the disk-shaped blade portion 15 are in contact with each other. The interval of the gap p between the adjacent disc-shaped blade portions 13 is substantially equal to the width of the disc-shaped blade portion 13. The interval of the gap p between the adjacent disc-like blade portions 15 is substantially equal to the width of the disc-like blade portion 15. A gap s is provided between the outer peripheral surface of the disk-shaped blade portion 13 and the outer peripheral surface of the rotary shaft 16 facing the outer peripheral surface. A gap s is provided between the outer peripheral surface of the disk-shaped blade portion 15 and the outer peripheral surface of the rotating shaft 14 facing the outer peripheral surface. The gap s is set to be equal to or greater than the thickness of the sheet.

  As indicated by arrows in FIG. 1, the rotary blade 9 and the rotary blade 11 rotate in opposite directions. The sheet is supplied to the meshing portion 19 between the rotary blade 9 and the rotary blade 11. The illustration of the sheet is omitted. The sheet supplied to the meshing unit 19 is drawn into the roll cutter 3 by the rotation of the rotary blade 9 and the rotary blade 11. The sheet drawn into the roll cutter 3 is cut by the rotary blade 9 and the rotary blade 11 and vertically cut into an elongated shape. The width of the vertically cut sheet corresponds to the gap p.

  The vertically cut sheet is sandwiched between the gaps p. A scraper 21 is provided to peel the vertically cut sheet from the gap p. The scraper 21 protrudes to the vicinity of the bottom surface of the gap p between the rotary blades. In other words, the scraper 21 reaches the vicinity of the outer peripheral surfaces of the rotating shaft 14 and the rotating shaft 16. The sheet separated from the rotary blade 9 or the rotary blade 11 by the scraper 21 is guided downward by the guide 23 and discharged from the discharge port 25.

  Although the space | interval of the clearance gap p is changed with the size of the pellet calculated | required, it is preferable to set to 1.0-5.0 mm, for example, More preferably, it is 1.5-3.5 mm. When this space | interval exceeds 5.0 mm, it may become difficult to peel by the said scraper 21. FIG. If it is less than 1.0 mm, the sheet may not be completely cut vertically.

  The vertically cut sheet discharged downward from the discharge port 25 is cut across. Crossing is performed by the crossing rotary blade 5 and the fixed blade 7. The transverse rotary blade 5 has a rotary shaft 27 and a blade portion 29. The rotation axis z3 of the transverse rotary blade 5 is parallel to the rotation axis z1 and the rotation axis z2.

  The blade portion 29 is provided on the outer peripheral surface of the transverse rotary blade 5. The blade portions 29 are provided at constant angles in the circumferential direction of the transverse rotary blade 5. In the embodiment of FIG. 1, the blade portions 29 are provided every 60 degrees in the circumferential direction of the transverse rotary blade 5. The fixed blade 7 is provided in the discharge port 25.

  The cutting edge of the fixed blade 7 and the cutting edge of the blade portion 29 are arranged so as to be close to each other. Due to the rotation of the transverse rotary blade 5, the blade portions 29 arranged at a plurality of positions in the circumferential direction approach the fixed blade 7 sequentially. The sheet is sheared by the fixed blade 7 and the blade portion 29. This shear cuts the sheet across. A sheet that has been cut long and narrow by vertical cutting is cut short by horizontal cutting to form pellets. The pellet size can be changed by the rotational speed of the roll cutter 3, the rotational speed of the transverse rotary blade 5, the arrangement interval of the blade portions 29, the interval of the gap p between the rotary blades, and the like. Moreover, the productivity of the cutting process can be improved when the rotational speed of the roll cutter 3 and the rotational speed of the transverse rotary blade 5 are higher. In order to change the rotation speed, for example, the frequency (Hz) of the drive motor that drives the rotation shaft and the number of rotations per minute (rpm) of the rotation shaft may be appropriately adjusted.

  In addition, it is preferable that a plurality of blade portions 29 of the transverse rotary blade 5 are provided at equal intervals in the circumferential direction. The number of the blade portions 29 is preferably 2 to 30, more preferably 2 to 20, and further preferably 3 to 10. If the number of blades 29 is less than 2, there is a risk that the replacement frequency of the blades will increase and it will be inferior in economic efficiency. If it exceeds 30 blades, the structure will be complicated and excessive costs will be required in preparation of the device. And may require labor.

  As the cutting device 1, various conventionally known sheet pelletizers can be appropriately modified and used. Specific examples of the sheet pelletizer include product name PM-350 manufactured by Tanaka Co., Ltd., and product names SGE-220 and SGE-350 manufactured by Horai Co., Ltd.

  From the viewpoint of increasing the productivity and reducing the pellet size, it is preferable that the rotational speed of the roll cutter 3 or the transverse rotary blade 5 is large. However, these rotational speeds have limitations. In the cutting process, heat is likely to be generated in the portion to be cut, and heat is particularly likely to be generated in crossing. Since the polyether polymer according to the present invention has a low melting point, the slipping property tends to be poor even at room temperature, and the slipping property is likely to be further deteriorated due to heat generation in the cutting process.

  When the rotational speed of the transverse cutting blade 5 is increased, the shearing speed in the transverse cutting is increased, and heat generation due to friction is likely to occur. Since polyether polymers have poor slipperiness, frictional heat tends to increase. Due to this heat generation, the slipperiness of the polyether polymer is further deteriorated, and clogging is likely to occur in the cutting device 1. From the viewpoint of suppressing this clogging, the rotational speed of the transverse rotary blade 5 needs to be suppressed to a predetermined value or less. If the rotational speed is excessively increased, clogging is likely to occur, and the length of the resulting pellets tends to be uneven. Even in the case of producing a fine pellet having a mass of 100 mg or less in the polyether polymer, it is difficult to make the content of the pellet of 100 mg or less 100% only by the cutting step. In order to obtain pellets having a more accurate particle size distribution, a classification step is performed.

[Classification process]
In the present invention, the pellets are classified. The classification eliminates too heavy pellets with high accuracy. The classification is preferably dry classification. The classification is preferably sieving classification. Classification may be done manually using a sieve. From the viewpoint of improving classification accuracy and productivity, classification is preferably performed using a classifier.

  The classifier that can be used in the present invention is not particularly limited. A preferred classifier includes a vibration classifier and a rotary classifier. The screen may be a flat surface or a curved surface such as a cylindrical surface. The shape of the screen that is a plane is not limited, and examples thereof include a rectangle and a circle. A horizontal classifier used in a state where the screen is horizontal may be used, or an inclined classifier used in a state where the screen is inclined.

  The vibration classifier vibrates a screen made of a wire mesh or punching metal. As a mode of this vibration, the vibration in the horizontal direction with respect to the screen (sieving surface), the vibration in the vertical direction with respect to the screen (sieving surface) (vertical vibration), the horizontal vibration and the vibration in the vertical direction are combined. Vibration etc. are mentioned. Examples of horizontal movement trajectories include a circle, an ellipse, a straight line, a spiral, and an 8-shaped (∞). This vibration makes it easy for the particles in contact with the screen to be replaced, and the classification accuracy and classification efficiency increase. As preferable vibration classifiers, for example, plastic pellet screeners (1301/1302 series, 1601/1602 series, 1901/1902 series, etc.) manufactured by Rotex Japan, circular vibratory sieves manufactured by Nishimura Machinery Co., Ltd., etc. Can be mentioned. In the rotary classifier, the screen is a cylindrical body, and classification is performed by rotating the cylindrical body. In this rotary classifier, for example, after a granular material or the like to be classified is put into a cylindrical body made of punching metal or the like, the cylindrical body rotates. The rotation of the cylindrical body moves the granular body or the cylindrical body and a centrifugal force acts on the granular body, so that classification accuracy and classification efficiency are improved. An example of such a rotary classifier is a pellet two-tank rotary sorter (SPSR-W series) manufactured by Seiwa Iron Works.

  FIG. 3 is a side view showing an example of a classifier 30 that can be used in the present invention. This classifier 30 is a vibration classifier. The classifier 30 has a vibration part 32 and a base part 34. Although not shown, the base 34 has a drive unit for vibrating the vibration unit 32. By this drive unit, the vibration unit 32 can vibrate. The whole vibration part 32 vibrates integrally. The base 34 is fixed to the floor surface. The base portion 34 has leg portions 36. The leg portion 36 ensures that the base portion 34 is fixed. Although illustration is omitted, the upper surface of the vibration unit 32 can be opened and closed, and a transparent window that enables observation of the inside of the vibration unit 32 is provided on the upper surface.

  The vibration part 32 is substantially box-shaped as a whole. The vibration part 32 is inclined with respect to the horizontal direction. The vibration part 32 has a supply port 38 and a discharge port 40. Although only one discharge port 40 is shown in FIG. 3, a plurality of discharge ports 40 are actually provided.

  Pellet (not shown) that requires classification is input from the supply port 38. Due to the vibration of the vibration part 32, the charged pellets move inside the vibration part 32. The pellet moves along the inclination of the vibration part 32. The pellet moves from the upper side (upstream side) of the inclination of the vibration part 32 to the lower side (downstream side). This movement direction is indicated by an arrow A in FIGS. With this movement, the pellets are classified. The classified and classified pellets are discharged from a plurality of discharge ports, respectively.

  FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. As shown in FIG. 4, a fine powder screen 42 and a screen 44 are provided inside the vibration unit 32. The fine powder screen 42 and the screen 44 have a large number of holes. The fine powder screen 42 is a wire mesh. The screen 44 is punching metal. The holes of the screen 44 are round holes. The holes in the screen 44 may be square holes.

  FIG. 5 is a cross-sectional view illustrating a schematic configuration of the vibration unit 32. As described above, the vibration unit 32 includes the supply port 38, the fine powder screen 42, and the screen 44. The fine powder screen 42 and the screen 44 are substantially on the same plane. The fine powder screen 42 and the screen 44 are inclined with respect to the horizontal plane. This inclination angle is the same as the inclination angle of the vibration part 3. Furthermore, the vibration part 32 has three discharge ports 40a, 40b, and 40c. The pellets introduced from the supply port 38 first move on the fine powder screen 42 toward the downstream side. The pellets that have passed through the fine powder screen 42 in the course of this movement are discharged from the discharge port 40a. The pellets that have not passed through the fine powder screen 42 move on the screen 44 and further move downstream on the screen 44. The pellets that have passed through the screen 44 in the course of this movement are discharged from the discharge port 40b. The pellets that have not passed through the screen 44 are discharged from the discharge port 40c. In FIG. 5, the description of the receiving portion 46 described later is omitted.

  The fine powder screen 42 is provided to remove fine powder. The size of the fine powder is extremely smaller than the required pellet size. The fine powder is, for example, burrs generated when the sheet is cut in the pellet manufacturing process, fine particles generated by abrasion between the pellets, and the like. A preferable aperture of the fine powder screen 42 is, for example, 0.1 μm or more and 1.0 μm or less, although it varies depending on the size of the classified pellets. The fine powder taken out from the outlet 40a through the fine powder screen 42 is discarded. The fine powder screen 42 is not essential, but is preferably provided. The fine powder enters the bearing portion of the screw that feeds the pellets, and can cause trouble that makes the screw difficult to rotate. This trouble can be avoided by removing the fine powder.

  The screen 44 classifies the pellets to a desired size. The opening of the screen 44 (diameter of the punch hole) is appropriately selected depending on the size of the pellet. Pellets that pass through the screen 44 and are taken out from the discharge port 40b are employed. The pellets that could not pass through the screen 44 are taken out from the outlet 40c and discarded.

  In FIG. 4, an arrow B indicates a motion locus of vibration of the vibration unit 32. The motion locus of vibration of the vibration part 32 is an eight-letter shape (∞ shape). The vibration part 32 vibrates in a direction horizontal to the screens 42 and 44. In other words, the vibration part 32 vibrates in the in-plane direction of the screens 42 and 44. This in-plane vibration is also referred to as in-plane vibration below. The in-plane vibration of the vibration unit 32 includes a vertical reciprocating vibration component and a horizontal reciprocating vibration component. The component of the longitudinal reciprocating vibration is indicated by a double arrow C in FIG. The component of the horizontal reciprocating vibration is indicated by a double arrow D in FIG.

  The fine powder screen 42 and the screen 44 vibrate due to the vibration of the vibration part 32. Further, the screen 44 vibrates in the out-of-plane direction. The out-of-plane direction is a direction perpendicular to the plane of the screen 44. This out-of-plane vibration is also referred to as out-of-plane vibration below. The fine powder screen 42 also vibrates out of plane. The direction of these out-of-plane vibrations is indicated by a double arrow E in FIG.

  The out-of-plane vibration of the screen is made by a tapper (not shown). The tapper is a device that taps the screens 42 and 44. The tapper is, for example, a cylinder that reciprocates. The tapper is driven by air, for example. The tapper strikes the screens 42 and 44 every predetermined time. For example, the tapper strikes the screen once every few seconds. The strength (tapping pressure) and period (tapping interval) with which the tapper strikes the screen can be automatically controlled. The tapper hits the screen from the bottom to the top, for example. As shown in FIG. 4, the screens 42 and 44 have a receiving portion 46 for colliding with the tapper. The receiving part 46 is a metal plate, for example. When the receiving portion 46 is hit, the screens 42 and 44 vibrate out of plane. By this out-of-plane vibration, clogging of the screen is suppressed, and the classification efficiency can be improved.

  When the tapping pressure is too small, the screen is likely to be clogged, and the productivity of the classification process may be lowered. If the tapping interval is too long, the screen is likely to be clogged, and the productivity of the classification process may be reduced. Therefore, from the viewpoint of improving productivity, it is preferable that the tapping pressure is large, and it is preferable that the tapping interval is short.

  However, if the tapping pressure is too high, the classification accuracy can be reduced. If the tapping interval is too short, the classification accuracy can be reduced. The reason for this will be described. Usually, a pellet is produced through a cutting process. In the pellet cutting step, first, the pellet material is processed into a long and thin material having a substantially constant cross-sectional shape, and then the long and narrow material is cut short (final cutting). For example, in the case of the cutting process described above, a state in which the sheet is vertically cut is a material having a long and thin shape, and the above-mentioned crossing is the final cutting. An error in the size (mass) of the pellet occurs mainly during this final cutting. That is, the error in the cutting length at the time of final cutting is the main cause of the error in the size (mass) of the pellet. If excessively long pellets are formed, the pellets can be eliminated by classification. However, if an excessively long pellet stands on the screen, the long and narrow pellet passes through the screen even though it is longer than the opening of the screen. Therefore, the probability that a pellet having a mass larger (longer) than the desired pellet passes through the screen increases, and the classification accuracy decreases. If the tapping pressure is too strong, the pellets are likely to stand on the screen. Therefore, the classification accuracy is increased by setting the tapping pressure to be equal to or less than the appropriate upper limit value. Similarly, when the tapping interval is too short, pellets are likely to stand on the screen. Therefore, the classification accuracy is improved by setting the tapping interval to an appropriate length or more. “Pellets stand” means that the longitudinal direction of the pellets is substantially vertical.

  Preferably, the classification step is performed in an atmosphere of dry air. Although not shown, the vibration part 32 has a discharge port for discharging dry air. A classification step is performed while flowing dry air into the vibration unit 32. Preferably, the classification step is performed in an air atmosphere having a dew point of −50 ° C. to −40 ° C. By reducing the dew point of the atmosphere, the adhesion of moisture to the pellet surface is suppressed. Thereby, the slidability of the pellet is improved, the clogging of the pellet can be suppressed, and the classification efficiency can be increased.

  Preferably, the classification is performed in two or more stages. The classification accuracy becomes extremely high by the classification of two or more stages. FIG. 6 is a diagram for explaining the two-stage classification. The classifier 30 described above is used in the first-stage classification, and the classifier 30 described above is also used in the second-stage classification. The pellets (accepted product) that have passed through the screen 44a in the first stage classification are used for the second stage classification (see arrow R in FIG. 6). And the pellet which passed the screen 44b of the 2nd step turns into a pass product. Classification may be in three or more stages. Thus, a preferable classification method performs classification using at least one screen having at least one kind of openings. In the embodiment of FIG. 6, a screen (screen 44a, screen 44b) having two types of openings is used.

  The opening (hole diameter) d1 of the screen 44a in the first-stage classification and the opening (hole diameter) d2 of the screen 44b in the second-stage classification may be the same or different. . Preferably, d1> d2. In other words, in multi-stage classification, it is preferable that the opening of the screen becomes smaller as the stages progress. By setting d1> d2, the classification speed (productivity) increases in the first-stage classification, and the classification accuracy increases in the second-stage classification. That is, by satisfying d1> d2, compatibility between productivity and classification accuracy is remarkably achieved. In addition, by setting d1> d2, the probability that the pellets that have not passed through the screen 44a in the first-stage classification include pellets that can be accepted products is reduced. Therefore, the classification yield increases. The difference [d1-d2] varies depending on the required size of the acceptable product, but is preferably about 0.2 mm to 1.0 mm, for example. If the difference [d1-d2] is too small, the effect of d1> d2 is reduced, and if it is too large, the effect of making the classification two or more steps is reduced, and the productivity tends to be lowered.

  When classification is performed in three or more stages, the “first stage classification” in the present application can be considered as the (N-1) th stage classification in the multi-stage classification. “Classification of stages” can be considered as classification of the Nth stage in multistage classification. However, N is an integer of 2 or more.

  There is a possibility that a pellet that can be accepted is present in the pellet that is rejected without passing through the screen 44b. If the pellets that can be accepted products can be selected as accepted products, the yield (classification yield) of the accepted products increases. From the viewpoint of increasing the classification yield, preferably, recycling classification is performed in which the pellets that have not passed through the screen 44b in the final stage of the two or more classifications are reclassified (see FIG. 6). The pellets that have not passed through the screen 44b in the final stage are subjected to reclassification together with unclassified pellets. This reclassification may be a single-stage classification or a multi-stage classification including two or more stages. For example, pellets that are rejected by two-stage classification may be subjected to two-stage classification as reclassification together with unclassified pellets. In addition, the pellet (failed product) that did not pass through the screen in the stage before the final stage (for example, the first stage) may be subjected to reclassification. However, the increase in the classification yield due to this can be limited in the above case where d1> d2, for example. This is because the opening d1 is increased, so that there is a low probability that the pellets that could not pass through the screen in the first stage classification include pellets that can be accepted products.

  From the viewpoint of increasing the classification yield, the opening d2 is preferably smaller than the opening d1. On the other hand, by reducing the opening d2, the probability that the pellets that could not pass through the screen in the final classification are included in the pellets that can be accepted products is increased. That is, there can be a disadvantage that the classification yield is lowered by reducing the opening d2. The above recycling classification can eliminate this drawback. By using the multi-stage classification and the recycling classification in combination, it is possible to achieve both the classification accuracy and the classification yield. A preferred recycle classification is a repetition of the same multi-stage classification. A preferable recycle classification is, for example, repetition of the same two-stage classification as shown in FIG.

  FIG. 7 is a cross-sectional view illustrating a schematic configuration of a vibration unit 48 according to another embodiment, and FIG. 8 is a cross-sectional view of the vibration unit 48 taken along line VIII-VIII in FIG. The vibrating portion 48 is provided with a regulating member 50 that is disposed above the screen 44 and regulates the height of the space on the screen 44. The difference between the vibration part 48 and the vibration part 32 is only the presence or absence of the regulating member 50.

  The regulating member 50 is a plate member. The restriction member 50 is a flat plate disposed substantially in parallel with the screen 44. The regulating member 50 is provided on the screen 44. The regulating member 50 covers the entire screen 44. The regulating member 50 is not provided on the fine powder screen 42.

  As described above, the pellet moves on the screen 44. However, the pellets may not move smoothly. That is, the pellets may stay and accumulate on the screen 44 or may become clogged on the screen 44. In particular, since the polyether polymer according to the present invention has a low melting point and a soft property, the slipperiness is poor and stagnation and accumulation are likely to occur. The regulating member 50 can suppress clogging of the pellet. That is, the restricting member 50 forcibly spreads the pellets on the screen 44 and suppresses the accumulation of pellets. Therefore, the restriction member 50 can suppress clogging of pellets.

  In FIG. 7, a double arrow S indicates a gap distance between the screen 44 and the regulating member 50. The gap distance S can be appropriately set depending on the size of the pellet, the slipperiness, and the like, and is, for example, 6 mm to 12 mm.

  FIG. 9 is a cross-sectional view illustrating a schematic configuration of a vibration unit 52 according to another embodiment, and FIG. 10 is a cross-sectional view of the vibration unit 52 taken along line XX in FIG. The vibrating portion 52 is provided with a regulating member 54 that is disposed above the screen 44 and regulates the height of the space on the screen 44. The restriction member 54 includes a plurality of restriction members 54a, 54b, and 54c. The difference between the vibration part 52 and the vibration part 32 is only the presence or absence of the regulating member 54.

  The regulating member 54 is a plate-like member. The restricting member 54 is a flat plate arranged substantially in parallel with the screen 44. The regulating member 54 is not provided on the fine powder screen 42.

  Unlike the restriction member 50 described above, the restriction member 54 is intermittently disposed with respect to the traveling direction A of the pellet. That is, the regulating member 54 has a gap in the traveling direction A of the pellet. There is a gap in the traveling direction A between the regulating member 54a and the regulating member 54b. Similarly, a gap exists in the traveling direction A between the regulating member 54b and the regulating member 54c. Since the height of the space on the screen is narrowed by the regulating member, the pellets may be clogged on the screen. The space on the screen 44 is opened by the gap. The gap can effectively suppress clogging of pellets between the screen 44 and the regulating member 54.

  As described above, since the polyether polymer has a low melting point and is soft, it has poor slipperiness. For this reason, a pellet is hard to slip on a screen. Non-slip pellets tend to stay or agglomerate on the screen. Non-slip pellets tend to be dango-like on the screen. Due to this stagnation or aggregation, clogging of pellets is likely to occur in the classifier. Thus, the pellet which uses a polyether-type polymer as base resin has bad classification efficiency, and a classification precision tends to fall. By the multistage classification as described above, the classification efficiency and classification accuracy can be improved even for pellets having a polyether-based polymer as a base resin. As described above, the present invention is particularly effective for pellets having poor sliding properties. From the viewpoint of revealing the effects of the present invention, the melting point of the polyether-based polymer is preferably 70 ° C. or lower, and more preferably 60 ° C. or lower. If the melting point is too low, it is difficult to form or cut into a sheet. From the viewpoint of improving the productivity in the cutting step, the polyether polymer preferably has a melting point of 30 ° C. or higher.

  When moisture adheres to the pellet surface, the slipperiness of the pellet is further deteriorated. From the viewpoint of suppressing the clogging of the pellets, the classification step is preferably performed in an atmosphere having a dew point of −30 ° C. or lower, and more preferably performed in an atmosphere having a dew point of −40 ° C. or lower.

  In the polyether polymer pellets of the present invention, the number N1 of particles having a mass of 100 mg or less is 99% or more with respect to the total number of particles N2. In other words, [N1 / N2] is set to 0.99 or more. More preferably, [N1 / N2] is 1.00.

  Preferably, in the polyether polymer pellet in the present invention, the number N3 of particles having a mass of 50 mg or less is 99% or more with respect to the total number of particles N4. In other words, [N3 / N4] is preferably 0.99 or more. More preferably, [N3 / N4] is 1.00.

  When pellets are used, they are extruded by an extruder such as a screw feeder. Larger pellets are longer. When pellets with a large mass are mixed, it may cause clogging in the extrusion process. The polyether polymer pellets having a high proportion of particles having a mass of 100 mg or less can suppress clogging in the pellet extrusion process. The pellet which concerns on this invention is used suitably as a raw material of the film used for a polymer battery etc., for example. Polyether polymer pellets with a high proportion of particles having a mass of 100 mg or less can increase feed accuracy and improve film thickness uniformity. Polyether polymer pellets with a small number of particles having a mass of 100 mg or less can be efficiently obtained by a classification step.

  The use of the polyether polymer according to the present invention is not limited. For example, polyurethane resins used for adhesives, pressure-sensitive adhesives, paints, sealing agents, elastomers, flooring agents, and the like, hard, soft or semi-rigid polyurethane resins Can be used. In addition, the polyether polymer according to the present invention includes surfactants, sanitary products, deinking agents, lubricating oils, hydraulic oils, polymer electrolytes, battery materials, flexographic printing plate materials, color filter protective films, etc. It can be preferably used in a very wide range of applications such as various functional materials.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Evaluation]
In the following examples, the classification yield E, the particle number ratio A1, and the particle number ratio B1 were evaluated.

[Classification yield]
When the mass of the acceptable product was Wg, the mass of the rejected product was Wf, and the mass of the discarded fine powder was Wb, the classification yield E was calculated by the following equation.
E = Wg / (Wg + Wf + Wb) × 100

  The classification yield E was measured in each of the first stage and the second stage. In the calculation of the first stage classification yield E, Wg is the mass of pellets that have passed through the screen in the first stage classifier, and Wf is the mass of pellets that could not pass through the screen in the first stage classifier. Yes, Wb is the mass of the pellets that passed through the fine powder screen in the first stage classifier. In the calculation of the second stage classification yield E, Wg is the mass of pellets that have passed through the screen in the second stage classifier, and Wf is the mass of pellets that could not pass through the screen in the second stage classifier. Yes, Wb is the mass of the pellets that passed through the fine powder screen in the second stage classifier.

[Particle number ratio A1, particle number ratio B1]
In order to evaluate the classification accuracy, the particle number ratio A1 and the particle number ratio B1 were measured.

[Particle number ratio A1]
100 pellets were arbitrarily selected, and the mass of each pellet particle was measured. The percentage (%) of the number of particles having a mass exceeding 50 mg to the total number of particles was defined as the particle number ratio A1. As the particle number ratio A1 is smaller, the classification accuracy is higher.

[Particle number ratio B1]
500 pellets were arbitrarily selected, and the mass of each pellet particle was measured. The percentage (%) of the number of particles having a mass exceeding 50 mg to the total number of particles was defined as the particle number ratio B1. As the particle number ratio B1 is smaller, the classification accuracy is higher.

[Production Example 1]
(Devolatilization process)
A resin solution (Mw: 108,000) obtained by copolymerization of ethylene oxide, 1,2-butylene oxide and allyl glycidyl ether was devolatilized in a toluene solvent. As an apparatus for devolatilization, EXEVA (Exeva) manufactured by Shinko Environmental Solution Co., Ltd. was used. The operating conditions of the EXEVA were a heating temperature of 100 ° C., a solution feed amount of 15 kg / hr, an operating pressure of 50 Torr, a stirring speed of 300 rpm, and a screw rotation speed of 97 rpm. Under this operating condition, the resin was discharged from the discharge port of EXEVA at a discharge speed of 7.5 kg / hr. In the discharged resin, the maximum resin temperature was 115 ° C., and the residual toluene amount was 0.64 wt%. Further, the molecular weight of the resin did not change before and after the treatment with EXEVA.

(Transfer by liquid feed line)
In order to use the resin after the devolatilization step for the kneading step, transfer was performed by a liquid feed line. About the resin discharged from the discharge port of EXEVA, it liquid-fed with the gear pump. The pipe heating temperature of the liquid feeding pipe was 120 ° C., and the liquid feeding speed was 96.6 kg / hr to 123 kg / hr. The temperature of the resin during feeding was 115 ° C. or higher and 119 ° C. or lower. The molecular weight of the resin did not change before and after feeding.

(Kneading process)
The antioxidant was kneaded with the resin sent through the liquid feed line. This kneading step was performed using a KRC kneader. In the charging method to the KRC kneader, the antioxidant was supplied from the upstream (motor side) charging port, and the molten resin was charged from the downstream (discharge port side) charging port. The charging speed of the molten resin was 30 kg / hr, the temperature of the supplied resin was 121 ° C., the jacket temperature was 60 ° C., and the rotation speed was 54 rpm. In the resin discharged from the KRC kneader, the discharge outlet temperature was 119 ° C., no change in the molecular weight of the resin was observed, and the proportion of antioxidant was 4484 ppm (average value). The variation of the ratio of the antioxidant was 8.9 of (6σ / average value) × 100. No vent-up was confirmed at the antioxidant inlet.

(Cooling process)
The resin discharged from the KRC kneader was cooled by a drum cooler manufactured by Mitsubishi Chemical Engineering. The operating condition of the drum cooler is that the supply resin temperature is 180 ° C., the pressure roll (PR) is stopped, the gap between the pressure roll and the roll is 3.0 mm, and the brine temperature to the drum (in / out) Was 9 ° C./11° C., and the rotation speed of the roll was 0.4 rpm. The cooling sheet that came out from the outlet of the cooling roll had a sheet thickness of 1.5 mm or more and 2.0 mm or less, a sheet temperature of 20 ° C., a good sheet peelability, and a good cutting state.

(Pelletization process (cutting process))
The cooling sheet was pelletized using a sheet pelletizer manufactured by Horai. The schematic configuration of the sheet pelletizer is the same as that of the sheet pelletizer 1 described in FIGS. 1 and 2. The sheet pelletizer was charged with a cooled sheet having a thickness of 1.5 to 2.0 mm. The charging speed was in the range of 1.8 (m / min) to 3.8 (m / min). The gap p (see FIG. 2) between the rotary blades in the sheet pelletizer is 3 mm, the mesh width w1 (see FIG. 2) of the rotary blades is 2.0 mm to 3.0 mm, and the fixed blade-comb blade of the horizontal blade ( The clearance of the scraper) + bottom raised portion was set to 3.0 mm to 8.0 mm, the vertical blade frequency was set to 15 to 26 Hz, and the horizontal blade frequency was set to 30 to 40 Hz. The vertical blade frequency is the frequency of an inverter that controls the rotational speed of a motor that rotates the vertical blade (rotating blade for vertical cutting). The higher the frequency, the higher the rotational speed. The horizontal blade frequency is a frequency of an inverter that controls the rotational speed of a motor that rotates the horizontal blade (transverse rotary blade). The higher the frequency, the higher the rotational speed. As a result of cutting by this pelletizer, square pellets having [average length × width × height] of [1.5 to 2.0 mm × 3 mm × 2.0 to 4.5 mm] in average are obtained. Then, the frequency in which each of the vertical, horizontal, and height average values ± 0.5 mm was 85 particles or more in 100 particles. The “vertical” dimension in [vertical × horizontal × height] corresponds to the sheet thickness, and the “horizontal” dimension corresponds to the gap p of the rotary blade.

[Example 1]
Using the unclassified square pellets obtained in Production Example 1, a classification process was performed. The target value of the pellet size was 4.0 mm (length) × 3.5 mm (width) × 1.8 mm (thickness).

  As a classifier, “Pellet Screener R1301” manufactured by Rotex Japan Co., Ltd. was used. The configuration of the classifier is the same as that shown in FIG. 3, FIG. 4 and FIG. Two-stage classification was performed using this classifier twice. In the first classification, the fine powder screen was a metal mesh with a 2.0 mm square opening, and the screen was a punching metal with a punch diameter of 5.0 mm. In the second stage classification, the fine powder screen was a metal mesh with a 2.0 mm square mesh, and the screen was a punching metal with a punch diameter of 4.5 mm.

In the first stage classification, the classifier specifications were as follows.
[Classification of the first stage]
・ Vibration frequency: 60Hz
・ Tapping pressure: 0.20 MPa
-Tapping interval: 3.5 seconds / time-Screen for fine powder and tilt angle of screen with respect to horizontal plane: 7 °
・ Punch diameter of screen: 5.0mm

  In the first-stage classification, unclassified pellets were charged into the classifier supply port at a rate of 56.5 kg per hour, and the treatment was continued for 60 minutes. In this first-stage classification, the classification yield E was 97.6%, and the particle number ratio A1 was 2%.

In the second stage classification, the classifier specifications were as follows.
[Second stage classification]
・ Vibration frequency: 60Hz
・ Tapping pressure: 0.25 MPa
-Tapping interval: 3.5 seconds / time-Screen for fine powder and tilt angle of screen with respect to horizontal plane: 7 °
・ Screen punch diameter: 4.5mm

  In the second-stage classification, the accepted pellets that passed through the screen (punching metal) in the first-stage classification were put into the supply port of the second-stage classifier. The charging speed was 46.6 kg per hour, and the treatment was continued for 58 minutes. In this second stage classification, the classification yield E was 88.4%, and the particle number ratio B1 was 0%.

[Example 2]
(First recycling; first stage)
The specifications of the classifier in the first stage were the same as those in the first stage in Example 1. The pellets that were rejected in the second stage classification in Example 1 and the unclassified pellets were mixed and put into a classifier. The pellet charging speed was 57.4 kg per hour, and the treatment was continued for 46 minutes. In the first stage of Example 2, the classification yield E was 97.5%, and the particle number ratio A1 was 2%.

(First recycling; second stage)
The specifications of the classifier in the second stage were the same as those in the second stage in Example 1. The accepted pellets obtained in the first stage classification in Example 2 were charged into the classifier in the second stage. The charging speed was 46.9 kg per hour, and the treatment was continued for 53 minutes. In the second stage of Example 2, the classification yield E was 88.0%, and the particle number ratio B1 was 0%.

[Example 3]
(Second recycling; first stage)
The specifications of the classifier in the first stage were the same as those in the first stage in Example 1. The rejected pellets obtained in the second stage classification in Example 2 and the unclassified pellets were mixed and charged into the classifier in the first stage. The input speed was 57.7 kg per hour, and the treatment was continued for 43 minutes. In the first stage of Example 3, the classification yield E was 97.7%, and the particle number ratio A1 was 0%.

(Second recycling; second stage)
The specifications of the classifier in the second stage were the same as those in the second stage in Example 1. The pellets of the accepted product obtained in the first stage classification in Example 3 were put into the classifier in the second stage. The charging speed was 47.4 kg per hour, and the treatment was continued for 49 minutes. In the second stage of Example 3, the classification yield E was 87.6%, and the particle number ratio B1 was 0%.

  In any of Examples 1 to 3, 40 kg or more of pellets having a particle number ratio B1 of 0% were obtained per hour. Examples 1 to 3 are excellent in productivity. Further, in all of Examples 1 to 3, the particle number ratio B1 of the second stage classification was 0%. Examples 1 to 3 are excellent in classification accuracy. Examples 1 to 3 show the effectiveness of the two-stage classification and the recycling classification.

[Example 4]
(the first stage)
The specifications of the classifier in the first stage were the same as those in the first stage in Example 1. The unclassified pellets obtained in Production Example 1 were charged into this classifier. The pellet charging speed was 86.0 kg per hour, and the treatment was continued for 40 minutes. In the first stage of Example 4, the classification yield E was 97.3%, and the particle number ratio A1 was 10%.

(Second stage)
The specifications of the classifier in the second stage were the same as those in the second stage in Example 1. The accepted pellets obtained in the first stage classification in Example 4 were charged into the classifier in the second stage. The charging speed was 81.6 kg per hour, and the treatment was continued for 40 minutes. In the second stage of Example 4, the classification yield E was 87.3%, and the particle number ratio B1 was 0%. Example 4 has high productivity and classification accuracy. Further, according to Example 4, the particle number ratio B1 in the second stage is significantly reduced as compared with the particle number ratio A1 in the first stage. Example 4 shows a remarkable effect by the two-stage classification.

(Filling process)
The filling process of filling the bags with classified pellets obtained in Examples 1 to 4 was performed. In the filling process, a vacuum gas filling long sealer LOS series manufactured by Fuji Impulse was used. First, the pellets were put into a flexible container bag with an aluminum inner bag, and then the aluminum inner bag was heat-sealed with a heat sealer, leaving a portion where the nozzle entered the center of the opening of the aluminum inner bag. This heat sealer is a sealer different from the above-described vacuum gas-filled long sealer. Next, this flexible container bag was set in a vacuum gas-filled long sealer, and the nozzle of the vacuum gas-filled long sealer was inserted into the center of the opening of the aluminum inner bag to perform heat sealing. There is one nozzle, the length of the nozzle is 240 mm, and four holes are formed on the side of the nozzle tip. At the time of heat sealing, a combination of degassing for 2.0 minutes and nitrogen replacement for 1.0 minutes was repeated twice, and double-sided heating was performed at 250 ° C. for 2 seconds. As a result, the degree of vacuum in the space in the bag after heat sealing was −70 kPa, and the oxygen concentration in this space was 0.2 to 0.45 vol%.
[Production Example 2]
(Devolatilization process)
A resin solution (Mw: 125,000) obtained by copolymerization of ethylene oxide and 1,2-butylene oxide was devolatilized in a toluene solvent. As an apparatus for devolatilization, EXEVA (Exeva) manufactured by Shinko Environmental Solution Co., Ltd. was used. The operating conditions of EXEVA were such that the heating temperature was 140 ° C., the solution feed amount was 22 kg / hr, the operating pressure was 50 Torr, the stirring speed was 300 rpm, and the screw rotation speed was 97 rpm. Under this operating condition, the resin was discharged from the EXEVA discharge port at a discharge speed of 9.9 kg / hr. In the discharged resin, the maximum resin temperature was 138 ° C., and the amount of residual toluene was 0.61 wt%. Further, the molecular weight of the resin did not change before and after the treatment with EXEVA.

(Transfer by liquid feed line)
In order to use the resin after the devolatilization step for the kneading step, transfer was performed by a liquid feed line. About the resin discharged from the discharge port of EXEVA, it liquid-fed with the gear pump. The pipe heating temperature of the liquid feeding pipe was 140 ° C., and the liquid feeding speed was 51.8 kg / hr to 69.0 kg / hr. The temperature of the resin during feeding was 132 ° C. or higher and 139 ° C. or lower. The molecular weight of the resin did not change before and after feeding.

(Kneading process)
The antioxidant was kneaded with the resin sent through the liquid feed line. This kneading step was performed using a KRC kneader. In the charging method to the KRC kneader, the antioxidant was supplied from the upstream (motor side) charging port, and the molten resin was charged from the downstream (discharge port side) charging port. The molten resin charging speed was 27 kg / hr, the temperature of the supplied resin was 138 ° C., the jacket temperature was 60 ° C., and the rotation speed was 54 rpm. In the resin discharged from the KRC kneader, the discharge outlet temperature was 133 ° C., no change in the molecular weight of the resin was observed, and the proportion of antioxidant was 5124 ppm (average value). The variation of the ratio of the antioxidant was 7.3, (6σ / average value) × 100. No vent-up was confirmed at the antioxidant inlet.

(Cooling process)
The resin discharged from the KRC kneader was cooled by a drum cooler manufactured by Mitsubishi Chemical Engineering. The operating condition of the drum cooler is that the supply resin temperature is 185 ° C., the pressure roll (PR) is stopped, the gap between the pressure roll and the roll is 3.5 mm, and the brine temperature to the drum (in / out) Was 10.4 ° C./11.5° C., and the roll rotation speed was 0.3 rpm. The cooling sheet that came out from the outlet of the cooling roll had a sheet thickness of 1.5 mm or more and 2.0 mm or less, a sheet temperature of 13.5 ° C., a good sheet peelability, and a good cutting state. .

(Pelletization process (cutting process))
The cooling sheet was pelletized using a sheet pelletizer manufactured by Horai. The schematic configuration of the sheet pelletizer is the same as that of the sheet pelletizer 1 described in FIGS. 1 and 2. The sheet pelletizer was charged with a cooled sheet having a thickness of 1.5 to 2.0 mm. The charging speed was in the range of 1.8 (m / min) to 3.8 (m / min). The gap p (see FIG. 2) between the rotary blades in the sheet pelletizer is 3 mm, the mesh width w1 (see FIG. 2) of the rotary blades is 2.0 mm to 3.0 mm, and the fixed blade-comb blade of the horizontal blade ( The clearance of the scraper) + bottom raised portion was set to 3.0 mm to 8.0 mm, the vertical blade frequency was set to 15 to 26 Hz, and the horizontal blade frequency was set to 30 to 40 Hz. As a result of cutting with this pelletizer, square pellets having [length × width × height] of [1.5 to 2.0 mm × 3 mm × 2.0 to 4.5 mm] in average were obtained. In this square pellet, the frequency of entering the average value ± 0.5 mm in each of the vertical, horizontal and height was 85 particles or more in 100 particles. The “vertical” dimension in [vertical × horizontal × height] corresponds to the sheet thickness, and the “horizontal” dimension corresponds to the gap p of the rotary blade.

[Examples 5 to 8]
Example 5 was made in the same manner as in Example 1 except that the square pellet obtained in Production Example 1 was changed to the square pellet obtained in Production Example 2. Example 6 was made in the same manner as in Example 2 except that the square pellet obtained in Production Example 1 was changed to the square pellet obtained in Production Example 2. Example 7 was made in the same manner as in Example 3 except that the square pellet obtained in Production Example 1 was changed to the square pellet obtained in Production Example 2. Example 8 was made in the same manner as Example 4 except that the square pellet obtained in Production Example 1 was changed to the square pellet obtained in Production Example 2.

(Filling process)
A filling step was performed in which the pellets of classification-accepted products obtained in Examples 5 to 8 were filled into bags. In the filling process, a vacuum gas filling long sealer LOS series manufactured by Fuji Impulse was used. First, the pellets were put into a flexible container bag with an aluminum inner bag, and then the aluminum inner bag was heat-sealed with a heat sealer, leaving a portion where the nozzle entered the center of the opening of the aluminum inner bag. This heat sealer is a sealer different from the above-described vacuum gas-filled long sealer. Next, this flexible container bag was set in a vacuum gas-filled long sealer, and the nozzle of the vacuum gas-filled long sealer was inserted into the center of the opening of the aluminum inner bag to perform heat sealing. There is one nozzle, the length of the nozzle is 240 mm, and four holes are formed on the side of the nozzle tip. At the time of heat sealing, a combination of degassing for 2.0 minutes and nitrogen replacement for 1.0 minutes was repeated twice, and double-sided heating was performed at 250 ° C. for 2 seconds. As a result, the degree of vacuum in the space in the bag after heat sealing was −70 kPa, and the oxygen concentration in this space was 0.2 to 0.45 vol%.

  The present invention can be applied to pellets having a polyether polymer as a base resin.

FIG. 1 is a side view showing a schematic configuration of a cutting device. FIG. 2 is a view of the roll cutter as viewed from above. FIG. 3 is a side view showing a schematic configuration of a classifier according to an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view illustrating a schematic configuration of the vibration unit. FIG. 6 is a diagram for explaining two-stage classification. FIG. 7 is a cross-sectional view illustrating a schematic configuration of a vibration unit according to another embodiment. FIG. 8 is a cross-sectional view of the vibration portion taken along line VIII-VIII in FIG. FIG. 9 is a cross-sectional view illustrating a schematic configuration of a vibration unit according to another embodiment. FIG. 10 is a cross-sectional view of the vibrating portion taken along line XX in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cutting device 3 ... Roll cutter 5 ... Transverse rotary blade 7 ... Fixed blade 9, 11 ... Rotary blade 13, 15 ... Disk-shaped blade part 21 ... Scraper 23 ... Guide 29 ... Blade part 30 ... Classifier 32, 48, 52 ... Vibration part 34 ... Base part 38 ... Supply port 40, 40a, 40b, 40c ... Discharge port 42 ... Screen for fine powder 44 ... Screen 50, 54 ... Regulator

Claims (4)

  A polyether polymer pellet in which the number of particles having a mass of 100 mg or less is 99% or more based on the total number of particles.   A multi-stage classification is performed in which a screen having at least one kind of openings is passed through two or more stages. By this multi-stage classification, the number of particles having a mass of 100 mg or less is 99% or more of the total number of particles. A classification method for obtaining ether polymer pellets.   The classification method according to claim 2, wherein the screen is punched metal.   The multi-stage classification is performed by passing two or more stages of screens having at least one kind of openings, and the pellets that have not passed through the screen in the final stage of the multi-stage classification are subjected to re-classification together with unclassified pellets. By this, the classification method which obtains the polyether-type polymer pellet whose number of particles which have a mass of 100 mg or less is 99% or more with respect to the total number of particles.

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