Method for producing thermoplastic resin and thermoplastic resin composition

Abstract

To provide manufacturing methods, capable of obtaining a thermoplastic resin and thermoplastic resin composition having small variations in physical properties.SOLUTION: A method for manufacturing a thermoplastic resin comprises (I) a polymerization step of supplying a resin raw material including a monomer (a) to a polymerization reaction vessel including a stirrer to perform a polymerization reaction and obtain a polymer (A) including a thermoplastic resin and (II) a collection step of extracting the thermoplastic resin from the polymer (A). The physical properties of the thermoplastic resin finally obtained are calculated using at least three operation data in continuous or intermittent operation data obtained in the (I) step and at least one operation datum in continuous or intermittent operation data obtained in the (II) step; and at least one process variable in process variables is controlled by providing the operation data in the (I) and (II) steps on the basis of the calculated physical properties.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In general, in the manufacture of resins, the physical properties of the resin are measured and controlled using the following methods and devices that embody the methods. For example, in the case of continuous production of vinyl resins, first, a resin raw material (vinyl monomers, etc.) is continuously supplied to a polymerization reactor, and the resin manufacturing conditions are operated according to the past operating conditions to carry out a polymerization reaction (polymerization process). Next, in this operating state, granulated resin is sampled from a stage that has gone through many processes after the polymerization process, and the physical properties are measured. The measured values ​​of the physical properties are compared with the target values ​​of the physical properties that have been set in advance, and the difference between the measured values ​​and the target values ​​is confirmed. Finally, in order to adjust this difference, the polymerization conditions in the polymerization process are changed and adjusted.

[0003] However, the above-mentioned manufacturing method has a problem in that it takes a considerable amount of time from the polymerization reaction to collection of the resin that is to become the final product, evaluation of its physical properties, and adjustment of the polymerization conditions (delay due to residence time), making it difficult to stabilize the physical properties of the resin.

[0004] In order to solve the above problems, a method for producing a resin has been proposed in which an online measuring device is installed in a resin production line and the physical properties of the resin are continuously calculated from the measured values, thereby adjusting the polymerization conditions. For example, a method for producing a resin has been disclosed in which a viscometer is installed at the outlet of the final reactor of a resin production line to continuously measure the viscosity of the final resin obtained and control the polymerization conditions based on the measured values ​​(see Patent Documents 1 to 4). Also disclosed is a method for predicting viscosity from reactor operation data (see Patent Document 5), and a method for producing a resin in which viscosity is predicted from a resin granulator and polymerization conditions are controlled (see Patent Document 6). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-80577 A [Patent Document 2] Japanese Patent Application Publication No. 9-71605 [Patent Document 3] JP 2002-145966 A [Patent Document 4] JP 2005-23213 A [Patent Document 5] JP 2011-245742 A [Patent Document 6] JP 2020-111639 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the resin manufacturing method disclosed in the above patent document, it is necessary to install additional analytical equipment during the manufacturing process, which makes the manufacturing process complicated. In addition, although it is possible to reduce the variation in the physical properties of the obtained resin by calculating the physical properties of the resin from the operation data of each manufacturing process that has been conventionally provided and changing the polymerization conditions, the accuracy of the conventionally proposed method is insufficient, and it is not possible to obtain a resin with small variation in physical properties.

[0007] Therefore, an object of the present invention is to provide a production method capable of obtaining a thermoplastic resin and a thermoplastic resin composition having small variations in physical properties. [Means for solving the problem]

[0008] The present inventors have found that although it is possible to grasp the physical properties of the resin to be the final product in real time from the operation data of the polymerization reactor, the physical properties of the resin also vary depending on the conditions of the recovery process after polymerization, and that when the type of operation data of the polymerization reactor is small or only the data of the recovery process including the granulation process cannot fully predict the resin properties of the polymer obtained in the polymerization reactor, the physical properties of the thermoplastic resin to be the final product vary. As a result of intensive research into the production method of thermoplastic resin, it has been found that a thermoplastic resin with small variation in physical properties can be obtained by grasping the physical properties of the thermoplastic resin to be the final product in real time from at least three or more operation data obtained from the polymerization reactor, which is an upstream process of the resin production process, and at least one or more operation data obtained from the recovery process of the thermoplastic resin, and controlling at least one process variable in the polymerization process or the recovery process using the physical properties as an index, and thus the present invention has been completed.

[0009] That is, the present invention has the following configuration. (1) A method for producing a thermoplastic resin, comprising: (I) a polymerization step of supplying a resin raw material containing a monomer (a) to a polymerization reactor equipped with a stirrer and polymerizing the resin to obtain a polymer (A) containing a thermoplastic resin; and (II) a recovery step of extracting the thermoplastic resin from the polymer (A), wherein physical properties of the thermoplastic resin finally obtained are calculated using at least three pieces of continuous or intermittent operation data obtained in the step (I) and at least one piece of continuous or intermittent operation data obtained in the step (II), and at least one process variable that provides the operation data in the steps (I) and (II) is controlled based on the calculated physical properties. (2) The method for producing a thermoplastic resin according to (1) above, characterized in that the at least one process variable is controlled by changing at least one selected from the group consisting of a set temperature in the polymerization reactor, a set pressure in the polymerization reactor, a set value of a polymerization initiator supply amount, and a set value of a chain transfer agent supply amount. (3) The method for producing a thermoplastic resin according to (1) or (2), characterized in that at least three pieces of operational data used in the step (I) include a chain transfer agent concentration in the polymerization reactor, a polymerization initiator concentration in the polymerization reactor, and a liquid phase temperature in the polymerization reactor, and at least one piece of operational data used in the step (II) includes an extruder power. (4) The method for producing a thermoplastic resin according to any one of (1) to (3) above, characterized in that the monomer (a) includes at least one selected from the group consisting of an aromatic vinyl monomer (a1) and a vinyl cyanide monomer (a2). (5) The method for producing a thermoplastic resin according to (4) above, characterized in that the monomer (a) further contains a monomer (a3) ​​copolymerizable with the aromatic vinyl monomer (a1) and the vinyl cyanide monomer (a2). (6) The method for producing a thermoplastic resin according to (5) above, wherein the monomer (a3) ​​is an unsaturated carboxylic acid alkyl ester monomer. (7) The method for producing a thermoplastic resin according to any one of (1) to (6), wherein the physical property of the thermoplastic resin is at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI, and HAZE, which are measured by a method conforming to any one of JIS, ISO, and ASTM. (8) The method for producing a thermoplastic resin according to any one of (1) to (7) above, characterized in that a soft sensor is used as a method for calculating physical properties of the thermoplastic resin.

[0010] (9) A method for producing a thermoplastic resin composition, comprising producing a thermoplastic resin by any one of the methods for producing a thermoplastic resin described in (1) to (8) above, and then (III) mixing the thermoplastic resin with a polymer (B) different from the polymer (A) in a molten state. (10) The method for producing a thermoplastic resin composition according to (9) above, wherein the polymer (B) is a graft copolymer (B1) obtained by graft polymerization of a monomer (b) containing an aromatic vinyl monomer (b1) and a vinyl cyanide monomer (b2) in the presence of a rubber-like polymer. (11) The method for producing a thermoplastic resin composition according to (10) above, characterized in that the monomer (b) further contains a monomer (b3) copolymerizable with the aromatic vinyl monomer (b1) and the vinyl cyanide monomer (b2). (12) The method for producing a thermoplastic resin composition according to (11) above, wherein the monomer (b3) is an unsaturated carboxylic acid alkyl ester monomer. (13) The method for producing a thermoplastic resin composition according to any one of (9) to (12), characterized in that physical properties of the finally obtained thermoplastic resin composition are calculated using at least three pieces of continuous or intermittent operation data obtained in the step (I), at least one piece of continuous or intermittent operation data obtained in the step (II), and at least one piece of continuous or intermittent operation data obtained in the step (III), and at least one process variable among the process variables that give the operation data in the steps (I), (II), and (III) is controlled based on the calculated physical properties. (14) The method for producing a thermoplastic resin composition according to (13) above, wherein at least one of the operational data used in the step (III) includes an extruder power. (15) The method for producing a thermoplastic resin composition according to (13) or (14) above, characterized in that the physical property of the thermoplastic resin composition is at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI and HAZE, measured by a method conforming to any one of JIS, ISO and ASTM. (16) The method for producing a thermoplastic resin composition according to any one of (13) to (15) above, characterized in that a soft sensor is used as a method for calculating physical properties of the thermoplastic resin composition. Effect of the Invention

[0011] The present invention is characterized in that the physical properties of the resin finally obtained are calculated from at least three pieces of operational data in the polymerization process, which is an upstream process in the thermoplastic resin production process, and at least one piece of operational data in the recovery process, which is a downstream process, and the process variables of the polymerization process or recovery process are quickly controlled using the physical properties as indicators. This makes it possible to obtain a thermoplastic resin with small variations in physical properties. Furthermore, according to the production method of the present invention, the process can be stabilized by controlling the process variables of the polymerization process or recovery process at an early stage in response to the calculated highly accurate physical property values ​​and their fluctuations. Furthermore, the method for producing a thermoplastic resin composition of the present invention uses a thermoplastic resin produced by the method of the present invention, and therefore it is possible to obtain a thermoplastic resin composition with small variation in physical properties. [Brief description of the drawings]

[0012] [Figure 1] 1 is a flow sheet showing one embodiment of a method for producing a thermoplastic resin according to the present invention. [Diagram 2] 1 is a flow sheet showing one embodiment of a method for producing a thermoplastic resin composition according to the present invention. [Diagram 3] 2 is a flow sheet showing another embodiment of the method for producing a thermoplastic resin composition according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The thermoplastic resin and the method for producing a thermoplastic resin composition of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments and can be practiced with any modifications.

[0014] In this specification, (meth)acrylate means acrylate or methacrylate.

[0015] (Method of manufacturing thermoplastic resin) The method for producing a thermoplastic resin according to the present invention includes (I) a polymerization step of supplying a resin raw material containing a monomer (a) to a polymerization reactor equipped with a stirrer and polymerizing the raw material to obtain a polymer (A) containing a thermoplastic resin, and (II) a recovery step of extracting a thermoplastic resin from the polymer (A). The thermoplastic resin production method of the present invention calculates physical properties of the finally obtained thermoplastic resin using at least three pieces of continuous or intermittent operation data obtained in step (I), which is an upstream process in the resin production process, and at least one piece of continuous or intermittent operation data obtained in step (II), which is a downstream process, and controls at least one process variable out of the process variables that provide the operation data in steps (I) and (II) based on the calculated physical properties. In other words, the method for producing a thermoplastic resin of the present invention focuses on the fact that the physical properties of a resin can be predicted with high accuracy from multiple operational data obtained from upstream and downstream processes, and by quickly calculating the physical properties, the process variables of step (I) or step (II) are controlled to keep the physical properties of the resin constant.

[0016] In the present invention, the term "operation data" refers to measurement data associated with the operation of equipment or a system, which is measured by measuring instruments and other auxiliary facilities attached to each process, and the term "process variable" refers to the operating conditions controlled based on the operation data.

[0017] The thermoplastic resin produced in the present invention is not particularly limited, and examples thereof include polyvinyl chloride, polyethylene, polypropylene, AS resin (acrylonitrile-styrene copolymer), MAS resin (methyl methacrylate-acrylonitrile-styrene copolymer), ABS resin (acrylonitrile-butadiene-styrene copolymer), MABS resin (methyl methacrylate-acrylonitrile-butadiene-styrene copolymer), AES resin (acrylonitrile-ethylene propylene-styrene copolymer), ASA resin (acrylonitrile-styrene-methyl acrylate copolymer), PMMA (polymethyl methacrylate), polystyrene, impact-resistant polystyrene, EVA (ethylene-vinyl acetate copolymer), polyamide, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polylactic acid, and the like. In particular, AS resin and MAS resin are preferred.

[0018] The polymerization method for the thermoplastic resin produced in the present invention is not particularly limited, and examples thereof include radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization, polycondensation polymerization, polyaddition polymerization, living polymerization, etc., and radical polymerization is particularly preferred. The polymerization may be continuous polymerization or batch polymerization.

[0019] 1, a production apparatus for carrying out the thermoplastic resin production method of the present invention includes a polymerization reactor 3 equipped with an agitator 2, into which a resin raw material is supplied and a polymerization reaction is carried out, and a resin recovery section 6 that extracts a thermoplastic resin as a final product from the reaction product (polymerized product) obtained in the polymerization reactor 3. Examples of the agitation blades of the agitator 2 that can be used include paddle blades, turbine blades, propeller blades, blue margin blades, multi-stage blades, anchor blades, max blend blades, and double helical blades.

[0020] The discharge port of the polymerization reactor 3 is equipped with a discharge device 4, and the reactants discharged from the polymerization reactor 3 by the discharge device 4 are sent to a resin recovery section 6 through a pipe 5, in which unreacted materials, solvent, etc. are removed from a vent 7, and the thermoplastic resin as the final product is taken out from a granulator 8. The unreacted materials, solvent, etc. taken out from the vent 7 may be returned to the polymerization reactor 3 for reuse, or may be discharged outside the system.

[0021] <(I) Process: Polymerization process> The step (I) is a polymerization step in which a resin raw material containing a monomer (a) is supplied to a polymerization reactor 3 equipped with an agitator 2 and polymerized to obtain a polymer (A) containing a thermoplastic resin.

[0022] The monomer (a) is appropriately selected depending on the desired resin. Examples of the monomer (a) include vinyl monomers, monomers copolymerizable with vinyl monomers, olefin monomers, etc. These monomers may be used alone or in combination of two or more.

[0023] Examples of the vinyl monomer include an aromatic vinyl monomer (a1) and a vinyl cyanide monomer (a2). Examples of the aromatic vinyl monomer (a1) include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, o-chlorostyrene, o,p-dichlorostyrene, or a mixture of two or more of these, with styrene and α-methylstyrene being particularly preferred. Examples of the vinyl cyanide monomer (a2) include acrylonitrile, methacrylonitrile, ethacrylonitrile, and mixtures of two or more of these, with acrylonitrile being particularly preferred. The vinyl monomer may be used alone or in combination of two or more kinds.

[0024] Examples of the monomer (a3) ​​copolymerizable with the vinyl monomer include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, unsaturated carboxylic acid alkyl esters such as methyl acrylate and methyl methacrylate, unsaturated dicarboxylic acids such as maleic acid, unsaturated dicarboxylic anhydrides such as maleic anhydride, N-substituted maleimides such as N-phenylmaleimide, and unsaturated amides such as acrylamide, with unsaturated carboxylic acid alkyl ester monomers being preferred. The monomer (a3) ​​copolymerizable with the vinyl monomer may be used alone or in combination of two or more.

[0025] Examples of the unsaturated carboxylic acid alkyl ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, 2,3,5-trimethylhexyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, and the like. Acrylate, tridecyl (meth)acrylate, 4-ethyl-5-methyloctyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, icosyl (meth)acrylate, behenyl (meth)acrylate, naphthyl (meth)acrylate, pyrenyl (meth)acrylate, biphenylyl (meth)acrylate, anthryl (meth)acrylate, phenanthryl (meth)acrylate, trityl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, and the like, with methyl (meth)acrylate being preferred.

[0026] Examples of the olefin monomer include olefins such as ethylene and propylene, and α-olefins (for example, α-olefins having 2 to 12 carbon atoms) such as 1-butene, isobutene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, and 1-decene-1. These may be used alone or in combination of two or more.

[0027] The resin raw material preferably contains a vinyl monomer as the monomer (a), more preferably contains at least one selected from the group consisting of an aromatic vinyl monomer (a1) and a vinyl cyanide monomer (a2), and further preferably contains at least one selected from the group consisting of an aromatic vinyl monomer (a1) and a vinyl cyanide monomer (a2) and a monomer (a3) ​​copolymerizable with the vinyl monomer.

[0028] The type and amount of the monomer (a) can be appropriately adjusted according to the desired thermoplastic resin and is optional.

[0029] The resin raw material may contain monomers other than the above-mentioned monomer (a), a polymerization initiator, a chain transfer agent, a solvent, and the like.

[0030] Examples of the monomer other than the monomer (a) include conjugated diene monomers such as butadiene, isoprene, and chloroprene.

[0031] In the step (I) of the present invention, when the polymer (A) is produced, it is possible to carry out thermal polymerization without using a polymerization initiator, to carry out initiator polymerization using a polymerization initiator, or to carry out both thermal polymerization and initiator polymerization. As the polymerization initiator, a peroxide or an azo compound is used.

[0032] Specific examples of peroxides include benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butylcumyl peroxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butylperoxyisopropylcarbonate, di-t-butyl peroxide, t-butyl peroctate, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, and t-butylperoxy-2-ethylhexanoate.

[0033] Specific examples of azo compounds include azobisisobutyronitrile, azobis(2,4-dimethylvaleronitrile), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1,1'-azobiscyclohexane-1-carbonitrile, azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, 1-t-butylazo-1-cyanocyclohexane, 2-t-butylazo-2-cyanobutane, and 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane.

[0034] In addition, when producing the polymer (A) in the step (I) of the present invention, it is preferable to add a chain transfer agent such as alkyl mercaptan, carbon tetrachloride, carbon tetrabromide, dimethylacetamide, dimethylformamide, triethylamine, etc., for the purpose of adjusting the degree of polymerization. Examples of the alkyl mercaptan used in the present invention include n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, etc., and among them, n-octyl mercaptan, t-dodecyl mercaptan, and n-dodecyl mercaptan are particularly preferably used as chain transfer agents.

[0035] When continuous solution polymerization is selected as the polymerization reaction in step (I), a solvent is used in addition to the monomer (a). The solvent used may contain water to a saturation level. Examples of the solvent include hydrocarbon solvents such as toluene, ethylbenzene, and xylene, and polar solvents such as methyl ethyl ketone, methyl isobutyl ketone, butyl alcohol, and tetrahydrofuran. Among these, polar solvents are preferred, more preferably solvents having a ketone group such as methyl ethyl ketone and methyl isobutyl ketone, and even more preferably methyl ethyl ketone in terms of the solubility of the polymer (A).

[0036] As for the other resin raw materials, one or more kinds can be used.

[0037] As shown in Fig. 1, a resin raw material containing a monomer (a) is supplied from a pipe 1 to a polymerization reactor 3, and polymerization is carried out by stirring the resin raw material with a stirrer 2, and a desired thermoplastic resin (polymer compound) is produced (polymerized). The polymerization reaction can be controlled by adjusting polymerization conditions such as the temperature in the polymerization reactor, the pressure in the polymerization reactor, the amount of polymerization initiator supplied (polymerization initiator concentration), the amount of chain transfer agent supplied (chain transfer agent concentration), and the residence time.

[0038] In the present invention, the resin material may be continuously or intermittently supplied to the polymerization reactor in step (I), and the polymerization mode may be any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. In order to rapidly predict physical properties with high accuracy, the polymerization mode is preferably continuous bulk polymerization or continuous solution polymerization.

[0039] In step (I), a polymer (A) is obtained which contains unreacted raw materials, oligomers, solvents, etc. in addition to the desired thermoplastic resin, so the thermoplastic resin is isolated in step (II).

[0040] <(II) Process: Recovery Process> The step (II) is a recovery step of recovering (isolating) a thermoplastic resin from the polymer (A) obtained in the step (I). In the step (II), unreacted materials, the solvent, etc. are removed in the resin recovery section 6, and the isolated thermoplastic resin is granulated in the granulator 8.

[0041] The resin recovery section 6 includes, for example, an extruder, a devolatilizer, a dehydrator, a dryer, etc., which may be used alone or in combination. In order to predict the physical properties of the final thermoplastic resin, it is preferable to have an extruder, and it is more preferable to combine two extruders. For example, when the resin recovery section 6 is an extruder having a vent 7, the vent 7 of the extruder is heated and in a normal pressure or reduced pressure state, and after volatile matter is removed from the vent port, strand-like resin is obtained from the extruder outlet, which is then granulated by a granulator 8 to obtain pellet-like resin.

[0042] <Control of process variables> As described above, a thermoplastic resin is produced by steps (I) and (II). In the method for producing a thermoplastic resin of the present invention, at least three pieces of continuous or intermittent operation data obtained in step (I) and at least one piece of continuous or intermittent operation data obtained in step (II) are used to calculate the physical properties of the thermoplastic resin that is finally obtained, and at least one process variable out of the process variables that provide the operation data in steps (I) and (II) is controlled based on the calculated physical properties.

[0043] (Operation data) Examples of measuring instruments associated with the (I) and (II) steps include thermometers, flowmeters, pressure gauges, current indicators, power meters, and liquid level gauges. Other associated equipment includes, for example, a distributed control system (DCS). The DCS can obtain not only instructions from the measuring instruments, but also a lot of data from automatic valves, control valves, and the like associated with the process.

[0044] Here, what is most relevant to the physical properties of the thermoplastic resin is the degree of polymerization of the thermoplastic resin finally obtained. There are multiple factors that determine the degree of polymerization of a thermoplastic resin, and it is difficult to accurately predict the degree of polymerization with only one or two pieces of operational data, so it is preferable to utilize more operational data. Even if the degree of polymerization can be predicted, the physical properties of the final resin will vary depending on the resin recovery conditions in step (II). For this reason, it is preferable to predict the physical properties of the final resin by utilizing operational data not only from step (I) but also from step (II).

[0045] Therefore, in order to accurately predict the physical properties of the final resin, including disturbance factors of the polymerization reaction, at least three pieces of continuous or intermittent operation data obtained in the (I) process and at least one piece of continuous or intermittent operation data obtained in the (II) process are used.

[0046] Examples of the operating data obtained in step (I) include the chain transfer agent concentration in the polymerization reactor, the polymerization initiator concentration in the polymerization reactor, the liquid phase temperature in the polymerization reactor, the NOM (n-octyl mercaptan) concentration in the polymerization reactor, the IPH (1,1-di(t-butylperoxy)cyclohexane) concentration in the polymerization reactor, the resin temperature in the polymerization reactor, the stirring power of the polymerization reactor, the solids concentration in the polymerization reactor, the pressure in the polymerization reactor, the outside air temperature, the jacket temperature of the polymerization reactor, the AN (acrylonitrile) flow rate, the ST (styrene) flow rate, the MMA (methyl methacrylate) flow rate, the gear pump rotation speed, the pressure of the resin discharged from the polymerization reactor, the height of the resin liquid level in the polymerization reactor, the AN temperature, the ST temperature, and the MMA temperature. Since the physical properties of the thermoplastic resin are significantly affected by information related to the molecular weight, solids concentration, composition, etc. of the polymer (A), by using operational data of at least three of these, it is possible to include multiple data that affect the physical properties of the thermoplastic resin, and therefore it is possible to quickly and accurately predict the physical properties.

[0047] Among these, the chain transfer agent concentration in the polymerization reactor, the polymerization initiator concentration in the polymerization reactor, and the liquid phase temperature in the polymerization reactor are factors that determine the degree of polymerization in the polymerization reaction of the resin, so it is preferable to use these operating data. The chain transfer agent concentration in the polymerization reactor is calculated by the ratio of the amount of chain transfer agent supplied from pipe 1 to the amount of polymer (A) obtained from a level gauge in the polymerization reactor. The polymerization initiator concentration in the polymerization reactor is calculated by the ratio of the amount of polymerization initiator supplied from pipe 1 to the amount of polymer (A) in the polymerization reactor. The liquid phase temperature in the polymerization reactor is obtained from a thermometer installed in the polymerization reactor.

[0048] Examples of the operational data obtained in step (II) include extruder power, extruder vent vacuum, extruder barrel temperature, extruder screw rotation speed, extruder inlet resin temperature, extruder outlet resin temperature, etc. Unreacted raw materials, oligomers, etc. remain in the polymer (A) polymerized in step (I), and the final thermoplastic resin is obtained after removing these. Therefore, in order to predict the physical properties of the final thermoplastic resin, it is preferable to utilize operational data that can take into account not only the degree of polymerization of the resin but also the amount of remaining unreacted raw materials, oligomers, etc.

[0049] In the present invention, it is preferable to use extruder power as at least one of continuous or intermittent operation data obtained from measuring instruments and other auxiliary equipment attached to the step (II). Extruder power is obtained from a power meter attached to the extruder.

[0050] (Process Variables) In the present invention, based on the above-mentioned operation data, the polymerization reaction in step (I) or the resin recovery conditions in step (II) are controlled by adjusting process variables.

[0051] The polymerization reaction is controlled by changing at least one of the process variables that provide the operating data in the step (I) so that the calculated physical properties approach the target resin physical properties, more preferably so that the resin properties become the target properties. The resin recovery conditions are controlled by changing at least one of the process variables that provide the operating data in the step (II) so that the calculated physical properties approach the target resin physical properties, more preferably so that the resin properties become the target properties.

[0052] Examples of process variables for controlling the polymerization reaction in step (I) include the set temperature in the polymerization reactor, the set pressure in the polymerization reactor, the set value of the polymerization initiator supply amount, the set value of the chain transfer agent supply amount, the set value of the polymerization reactor jacket temperature, the discharge output set value of the polymerization reactor discharge device, the set value of the resin raw material supply amount, and the set value of the recovered raw material supply amount. Among these, it is preferable to adjust the process variables by changing at least one selected from the group consisting of the set temperature in the polymerization reactor, the set pressure in the polymerization reactor, the set value of the polymerization initiator supply amount, and the set value of the chain transfer agent supply amount.

[0053] When the temperature inside the polymerization reactor increases, the degree of polymerization of the final resin decreases and the extruder power changes, and when the temperature decreases, the degree of polymerization of the final resin increases and the extruder power changes. When the pressure in the polymerization reactor increases, the degree of polymerization of the final resin decreases and the extruder power changes, and when the pressure decreases, the degree of polymerization of the final resin increases and the extruder power changes. Furthermore, if the amount of polymerization initiator supplied is large, the degree of polymerization of the final resin decreases, and the extruder power changes. Conversely, if the amount of polymerization initiator supplied is small, the degree of polymerization of the final resin increases, and the extruder power changes. If the amount of chain transfer agent supplied is large, the degree of polymerization of the final resin will decrease, and the extruder power will decrease. Conversely, if the amount of chain transfer agent supplied is small, the degree of polymerization of the final resin will increase, and the extruder power will increase. In addition, if the extruder is equipped with a vent, the power required for the extruder will change depending on the amount of unreacted raw materials or oligomers, etc., removed from the vent.

[0054] When the final physical properties are controlled by controlling process variables in step (II), at least one of the process variables may include the resin temperature in the resin recovery section, the heating temperature in the resin recovery section, the resin pressure in the resin recovery section, the degree of vacuum in the resin recovery section, and the extruder rotation speed.

[0055] Therefore, by calculating the physical properties of the thermoplastic resin finally obtained using at least three pieces of continuous or intermittent operation data obtained in step (I) and at least one piece of continuous or intermittent operation data obtained in step (II), it is possible to quickly control the polymerization reaction conditions or resin recovery conditions.

[0056] As described above, the physical properties of the resin are determined using at least three pieces of operation data in step (I) and at least one piece of operation data in step (II), but the number of pieces of operation data used in step (I) is preferably 5 or more, more preferably 10 or more, and the number of pieces of operation data used in step (II) is preferably 3 or more, more preferably 5 or more. The more operation data used, the more accurate the control of the process variables can be achieved, so there is no particular upper limit.

[0057] In the method for producing a thermoplastic resin of the present invention, the operation data of steps (I) and (II) are preferably measured continuously in order to quickly predict the physical properties of the resin. Here, "measure continuously" includes the case where measurements are made intermittently at regular intervals as long as the measurements are continued, and means "measure continuously" and "measure intermittently at regular intervals".

[0058] In addition, when the measurement is performed intermittently, it is preferable to perform the measurement for a time less than half the residence time from the polymerization reaction to the sampling of the resin to be the final product. The measurement intervals of the stirring power of the polymerization reactor and the solid content concentration in the polymerization reactor may be appropriately set according to the residence time, but it is more preferable to perform the measurement continuously at intervals of 60 minutes or less, further preferably at intervals of 1 second to 30 minutes, and particularly preferably at intervals of 1 second to 10 minutes.

[0059] In this manner, in the method for producing a thermoplastic resin of the present invention, the physical properties of the thermoplastic resin finally obtained are calculated using at least three pieces of continuous or intermittent operation data obtained in step (I) and at least one piece of continuous or intermittent operation data obtained in step (II), thereby quickly controlling the conditions of the polymerization reaction and enabling accurate and stable control of the physical properties of the produced resin.

[0060] <Physical Properties> The physical property of the thermoplastic resin controlled in the present invention is preferably at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI and HAZE, measured by a method conforming to any one of JIS, ISO and ASTM.

[0061] In particular, in the present invention, MFR, which is an index of resin fluidity depending on the degree of polymerization of the resin, can be predicted with high accuracy. In addition, by stably controlling MFR, the fluidity of the resin is stabilized, and therefore the tensile strength, flexural strength, Izod impact strength, Charpy impact strength, and deflection temperature under load are also stabilized. In addition, the tensile strength, flexural strength, Izod impact strength, Charpy impact strength, and deflection temperature under load decrease with an increase in MFR, and the tensile strength, flexural strength, Izod impact strength, Charpy impact strength, and deflection temperature under load increase with a decrease in MFR. The YI, which is an optical property of the resin, varies depending on the thermal history until the final resin is obtained, but the final YI of the resin can be predicted by predicting the thermal history from the operation data obtained from the (I) and (II) steps. In addition, the haze increases with an increase in YI, and the haze decreases with a decrease in YI.

[0062] In this manner, in the method for producing a thermoplastic resin of the present invention, at least three pieces of continuous or intermittent operation data obtained in step (I) and at least one piece of continuous or intermittent operation data obtained in step (II) are used to calculate at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI, and HAZE, which are measured according to a method conforming to any one of JIS, ISO, and ASTM, as a physical property of the finally obtained thermoplastic resin, and at least one of the process variables in step (I) or (II) is promptly controlled, thereby enabling precise and stable control of the physical properties of the produced resin.

[0063] <Physical property calculation method> In the present invention, it is preferable to utilize a soft sensor as a method for calculating the physical properties of a thermoplastic resin. A soft sensor mathematically calculates the relationship between the measured value of a variable that is relatively easily measured and a target state quantity. In the present invention, it is preferable to utilize the soft sensor and select and use a statistical model using at least three pieces of continuous or intermittent operation data obtained in the step (I) and at least one piece of continuous or intermittent operation data obtained in the step (II) to create a physical property prediction equation for the thermoplastic resin.

[0064] The above statistical model is not particularly limited, and any statistical model that is used in constructing typical soft sensors, such as a linear model or a nonlinear model, can be used. However, since a linear model may result in poor accuracy due to over-learning, a nonlinear model is preferable. When using a soft sensor, as described above, past data is learned about the relationship between the measured values ​​of the measured variables and the target state quantity, and an estimation formula for the relationship is created in advance. The target state quantity is then calculated online from the measured values ​​of the variables measured online and the estimation formula. Overlearning refers to the state quantity predicted from the estimation formula not matching the actual state quantity when the estimation formula created from this past data is applied to the online unknown data to be actually predicted. Therefore, in the present invention, a nonlinear model is preferable as a statistical model with good accuracy.

[0065] (Method of producing thermoplastic resin composition) The present invention also provides a method for producing a thermoplastic resin composition by obtaining a thermoplastic resin by the above-mentioned steps (I) and (II), and then, in step (III), mixing the obtained thermoplastic resin with a polymer (B) different from the polymer (A) in a molten state.

[0066] <(III) Process: Mixing process> The polymer (B) is not particularly limited, and examples thereof include polyvinyl chloride, polyethylene, polypropylene, AS resin (acrylonitrile-styrene copolymer), MAS resin (methyl methacrylate-acrylonitrile-styrene copolymer), ABS resin (acrylonitrile-butadiene-styrene copolymer), MABS resin (methyl methacrylate-acrylonitrile-butadiene-styrene copolymer), AES resin (acrylonitrile-ethylene propylene-styrene copolymer), ASA resin (acrylonitrile-styrene-methyl acrylate copolymer), PMMA (polymethyl methacrylate), polystyrene, impact-resistant polystyrene, EVA (ethylene-vinyl acetate copolymer), polyamide, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polylactic acid.

[0067] Among them, the polymer (B) is preferably a graft copolymer (B1) obtained by graft polymerization of a monomer (b) containing an aromatic vinyl monomer (b1) and a vinyl cyanide monomer (b2) in the presence of a rubber-like polymer.

[0068] The rubber-like polymer constituting the graft copolymer (B1) is a diene rubber, an acrylic rubber, an ethylene rubber, etc., and specific examples include polybutadiene, poly(butadiene-styrene), poly(butadiene-achloronitrile), polyisoprene, poly(butadiene-methyl acrylate), poly(butadiene-methyl methacrylate), poly(butadiene-ethyl acrylate), ethylene-propylene rubber, ethylene-propylene-diene rubber, poly(ethylene-isobutylene), poly(ethylene-methyl acrylate), etc. These rubbery polymers are used alone or in a mixture of two or more. Among these rubbery polymers, diene rubbers are preferably used, and among the diene rubbers, polybutadiene, poly(butadiene-styrene), poly(butadiene-acrylonitrile), and ethylene-propylene rubber are particularly preferably used.

[0069] Examples of the aromatic vinyl monomer (b1) include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, o-chlorostyrene, o,p-dichlorostyrene, or a mixture of two or more of these, with styrene and α-methylstyrene being particularly preferred. Examples of the vinyl cyanide monomer (b2) include acrylonitrile, methacrylonitrile, ethacrylonitrile, and mixtures of two or more of these, with acrylonitrile being particularly preferred. The aromatic vinyl monomer (b1) and the vinyl cyanide monomer (b2) may each be used alone or in combination of two or more kinds.

[0070] The monomer (b) may be composed of an aromatic vinyl monomer (b1) and a vinyl cyanide monomer (b2), or may contain the aromatic vinyl monomer (b1), the vinyl cyanide monomer (b2), and a monomer (b3) copolymerizable therewith.

[0071] Examples of the monomer (b3) include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, unsaturated carboxylic acid alkyl esters such as methyl acrylate and methyl methacrylate, unsaturated dicarboxylic acids such as maleic acid, unsaturated dicarboxylic anhydrides such as maleic anhydride, N-substituted maleimides such as N-phenylmaleimide, and unsaturated amides such as acrylamide, with unsaturated carboxylic acid alkyl ester monomers being preferred. The monomers (b3) may be used singly or in combination of two or more.

[0072] Examples of the unsaturated carboxylic acid alkyl ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, 2,3,5-trimethylhexyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, and the like. Acrylate, tridecyl (meth)acrylate, 4-ethyl-5-methyloctyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, icosyl (meth)acrylate, behenyl (meth)acrylate, naphthyl (meth)acrylate, pyrenyl (meth)acrylate, biphenylyl (meth)acrylate, anthryl (meth)acrylate, phenanthryl (meth)acrylate, trityl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, and the like, with methyl (meth)acrylate being preferred.

[0073] The monomer (b) which is the raw material of the graft copolymer (B1) is preferably the same as the monomer (a) in the step (I) from the viewpoint of dispersibility in the thermoplastic resin.

[0074] In step (III), the method for mixing the thermoplastic resin and the polymer (B) is not particularly limited. The thermoplastic resin produced and granulated in steps (I) and (II) and the polymer (B) can be continuously added to a vented extruder and mixed in a molten state.

[0075] From the viewpoints of color tone and impact resistance, it is preferable to feed the molten polymer (A) to a vented extruder in step (II), remove unreacted raw materials and oligomers from the vent, add the polymer (B) to the molten thermoplastic resin in the extruder, and then melt mix the polymer (B). The melt mixing may be performed during the addition mixing or after isolating the mixture, for example, during melt molding.

[0076] The continuous addition method is not particularly limited, and can be added by any method. Usually, various feeders such as belt feeders, screw feeders, extruders, etc. are used, but extruders are particularly preferred. These continuous addition devices are preferably ones that can measure the amount. In addition, the continuous addition device has a heating device, and it is preferable to add the polymer (B) in a semi-molten or molten state, since this improves the mixing state. For this purpose, an extruder having a heating device can be used.

[0077] If necessary, a process for adding antioxidants such as hindered phenols, sulfur-containing organic compounds, and phosphorus-containing organic compounds, heat stabilizers such as phenols and acrylates, ultraviolet absorbers such as benzotriazoles, benzophenones, and salicylates, various stabilizers such as organic nickel and hindered amine light stabilizers, metal salts of higher fatty acids, lubricants such as higher fatty acid amides, plasticizers such as phthalates and phosphates, halogen-containing compounds such as polybrominated diphenyl ether, tetrabromobisphenol-A, brominated epoxy oligomers, and brominated polycarbonate oligomers, phosphorus compounds, flame retardants and flame retardant assistants such as antimony trioxide, antistatic agents, carbon black, titanium oxide, pigments, and dyes, and liquids such as water, silicone oil, and liquid paraffin can also be added. Furthermore, a process for adding reinforcing agents and fillers such as glass fibers, glass flakes, glass beads, carbon fibers, and metal fibers can also be added. The method of adding these additives is not particularly limited, and various methods can be used, such as adding them continuously together with the polymer (B) or adding them as a post-process after isolating a mixture of the polymer (A) and the polymer (B).

[0078] In the present invention, since the operation data in step (III) contains important information related to the physical properties of the polymer (B) or the thermoplastic resin composition finally obtained, in order to accurately predict the physical properties of the final thermoplastic resin composition, it is preferable to calculate the physical properties of the finally obtained thermoplastic resin composition using at least three pieces of operation data among the continuous or intermittent operation data obtained in step (I), at least one piece of operation data among the continuous or intermittent operation data obtained in step (II), and at least one piece of operation data among the continuous or intermittent operation data obtained in step (III), and to control at least one process variable among the process variables that give the operation data in steps (I), (II), and (III) based on the calculated physical properties.

[0079] Here, the operating data and process variables obtained in steps (I) and (II) are as described above.

[0080] Examples of the operating data obtained in step (III) include the extruder power, the extruder screw rotation speed, the extruder barrel temperature, the flow rate of the thermoplastic resin, the flow rate of the polymer (B), the flow rate of the additives, the total discharge flow rate, the extruder outlet resin temperature, and the water content of the polymer (B). Of these, it is preferable to use the power of an extruder.

[0081] Examples of process variables for controlling the mixing conditions in step (III) include the outlet resin temperature of the resin mixing section, the heating temperature of the resin mixing section, the resin pressure of the resin mixing section, the degree of vacuum in the resin mixing section, the screw rotation speed of the resin mixing section, the supply amount of polymer (B), etc. Among these, it is preferable to adjust the process variables by changing at least one selected from the heating temperature of the resin mixing section, the degree of vacuum in the resin mixing section, the screw rotation speed of the resin mixing section, and the supply amount of polymer (B).

[0082] In producing a thermoplastic resin composition, the physical property of the thermoplastic resin composition controlled in the present invention is preferably at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI, and HAZE, measured by a method conforming to any one of JIS, ISO, and ASTM.

[0083] When producing a thermoplastic resin composition, the physical properties of the thermoplastic resin composition vary depending on the respective physical properties of the thermoplastic resin and the polymer (B). In particular, since the operation data related to the physical properties of the polymer (B) are included in the (III) step, the MFR can be predicted with particularly high accuracy by using at least one of the operation data of the (III) step together with the operation data of the (I) and (II) steps. In addition, by stably controlling the MFR, the fluidity of the resin composition is stabilized, and therefore the tensile strength, bending strength, Izod impact strength, Charpy impact strength, and deflection temperature under load are also stabilized. Note that an increase in the MFR reduces the tensile strength, bending strength, Izod impact strength, Charpy impact strength, and deflection temperature under load, and a decrease in the MFR increases the tensile strength, bending strength, Izod impact strength, Charpy impact strength, and deflection temperature under load. The YI, which is an optical property of a resin composition, varies depending on the thermal history until the final resin composition is obtained, but the YI of the final resin composition can be predicted by predicting the thermal history from the operation data obtained from steps (I), (II), and (III). Furthermore, an increase in YI increases haze, and a decrease in YI decreases haze.

[0084] In this manner, in the method for producing a thermoplastic resin composition of the present invention, at least three pieces of continuous or intermittent operation data obtained in step (I), at least one piece of continuous or intermittent operation data obtained in step (II), and at least one piece of continuous or intermittent operation data obtained in step (III) are used to calculate at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI, and HAZE, which are measured by a method conforming to any one of JIS, ISO, and ASTM, as the physical properties of the finally obtained thermoplastic resin composition. At least one of the process variables in steps (I), (II), and (III) is promptly controlled, thereby enabling the physical properties of the produced thermoplastic resin composition to be controlled with high precision and stability.

[0085] In the present invention, it is preferable to utilize a soft sensor as a method for calculating the physical properties of the thermoplastic resin composition. It is preferable to utilize the soft sensor and select and use a statistical model using at least three pieces of continuous or intermittent operation data obtained in the step (I), at least one piece of continuous or intermittent operation data obtained in the step (II), and at least one piece of continuous or intermittent operation data obtained in the step (III), to create a physical property prediction equation for the finally obtained thermoplastic resin composition.

[0086] The statistical model is not particularly limited, and the same models as those described above can be used, and the preferred models are also the same.

[0087] In the present invention, examples of the method for carrying out step (III) include a method (continuous method) in which steps (I) and (II) are carried out consecutively as shown in FIG. 2, and a method (CE method) in which the step (III) is carried out using the granulated product of the thermoplastic resin obtained by steps (I) and (II) as shown in FIG. 3.

[0088] As shown in Fig. 2, the production apparatus in the case of the linking method includes a polymerization reactor 11 equipped with an agitator 10 to which a resin raw material is supplied and a polymerization reaction is carried out, a first resin recovery section 14 to remove unreacted raw materials from the polymer (A) obtained in the polymerization reactor 11, and a second resin recovery section 17 equipped with a resin addition section 19 to supply the polymer (B). Unreacted raw materials are further removed in the second resin recovery section 17, and the thermoplastic resin and polymer (B) are mixed in the subsequent stage, after which the mixture is granulated in a granulator 20 to obtain a final thermoplastic resin composition.

[0089] The discharge port of the polymerization reactor 11 is equipped with a discharge device 12, and the reactants discharged from the polymerization reactor 11 by the discharge device 12 are sent to a first resin recovery section 14 through a pipe 13, and unreacted materials, solvents, etc. are removed from a vent 15 in the first resin recovery section 14. The thermoplastic resin recovered in the first resin recovery section 14 is sent to a second resin recovery section 17 through a pipe 16, and after unreacted materials, solvents, etc. are similarly removed from a vent 18 in the second resin recovery section 17, the thermoplastic resin is melt-mixed with the polymer (B).

[0090] As the impeller of the agitator 10, for example, a paddle impeller, a turbine impeller, a propeller impeller, a blue margin impeller, a multi-stage impeller, an anchor impeller, a max blend impeller, and a double helical impeller can be used. In addition to the above-mentioned steps, the method of the present invention may include any other steps. Examples of other steps include a resin cooling step and a resin drying step.

[0091] The manufacturing apparatus in the case of using the CE method includes a thermoplastic resin manufacturing apparatus as shown in Fig. 1 and a mixer for melt-mixing the thermoplastic resin and the polymer (B), as shown in Fig. 3. The mixer includes a resin mixing section 22, and the granulated product of the thermoplastic resin manufactured by the thermoplastic resin manufacturing apparatus is charged together with the polymer (B) into a resin adding section 21 attached to the resin mixing section 22, and after being melt-mixed in the resin mixing section 22, is granulated in a granulator 23, and the final thermoplastic resin composition is obtained.

[0092] The first resin recovery section 14 and the second resin recovery section 17 shown in FIG. 2, and the resin mixing section 22 shown in FIG. 3 preferably have an extruder.

[0093] The method of the present invention can be carried out manually or automatically. By programming the above polymerization control and incorporating it into a computer, it is possible to automatically control the polymerization conditions. The automatic control program may be created by oneself, or commercially available program software such as Knowledge Power (Azbil Corporation) or Exapilot (Yokogawa Electric Corporation) may be used. EXAMPLES

[0094] The method for producing a resin of the present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples in any way.

[0095] In the examples and comparative examples, the MFR (Melt Flow Rate) of the resin was measured according to the method described in ISO 1133 at a temperature of 220°C and a load of 58.8N for AS resin and MAS resin, and at a temperature of 220°C and a load of 98.0N for ABS resin and MABS resin. The YI of the resin was measured according to the method described in JIS K7373.

[0096] (Reference Example 1) Method for producing graft copolymer (B-1-1) (emulsion polymerization) 50 parts by mass (solid content equivalent) of polybutadiene latex (rubber particle diameter 0.3 μm, gel content 85%, refractive index 1.52), 200 parts by mass of pure water, 0.4 parts by mass of sodium formaldehyde sulfoxylate, 0.1 parts by mass of sodium ethylenediaminetetraacetate, ferrous sulfate (0.01 parts by mass) and 0.1 parts by mass of sodium phosphate were charged into a reaction vessel, and after nitrogen replacement, the temperature was adjusted to 65 ° C., and a mixture of 35 parts by mass of styrene, 15 parts by mass of acrylonitrile and 0.3 parts by mass of n-dodecyl mercaptan was continuously dropped over 4 hours under stirring. At the same time, a mixture of 0.25 parts by mass of cumene hydroperoxide, 2.5 parts by mass of sodium laurate as an emulsifier and 25 parts by mass of pure water was continuously dropped over 5 hours, and after the end of the dropwise addition, the mixture was held for another hour to terminate the polymerization. After the polymerization, the latex was coagulated with 1.5% sulfuric acid, neutralized with an alkali, washed, centrifuged, and dried to prepare a powder of the graft copolymer (B-1-1).

[0097] (Reference Example 2) Production method of graft copolymer (B-1-2) (emulsion polymerization) 50 parts by mass (solid content equivalent) of polybutadiene latex (rubber particle diameter 0.3 μm, gel content 85%), 180 parts by mass of pure water, 0.4 parts by mass of sodium formaldehyde sulfoxylate, 0.1 parts by mass of sodium ethylenediaminetetraacetate, 0.01 parts by mass of ferrous sulfate and 0.1 parts by mass of sodium phosphate were charged into a reaction vessel, and after nitrogen replacement, the temperature was adjusted to 65 ° C., and a mixture of 11.5 parts by mass of styrene, 4.0 parts by mass of acrylonitrile, 34.5 parts by mass of methyl methacrylate and 0.3 parts by mass of n-dodecyl mercaptan was continuously dropped over 4 hours while stirring. At the same time, a mixture of 0.25 parts by mass of cumene hydroperoxide, 2.5 parts by mass of sodium oleate as an emulsifier and 25 parts by mass of pure water was continuously dropped over 5 hours, and after the end of the dropwise addition, the mixture was held for another 1 hour to terminate the polymerization. The latex-like product after the polymerization was poured into 2,000 parts by mass of water at 95°C containing 1.0 part by mass of sulfuric acid while stirring to coagulate it, and then neutralized with an alkali, washed, centrifuged, and dried to prepare a powdery graft copolymer (B-1-2).

[0098] Example 1 The resin production apparatus used was as shown in FIG. A continuous resin production apparatus was used, which was equipped with a polymerization reactor 3 (volume 20 L) equipped with a helical ribbon blade as the agitator 2 and an extruder as the resin recovery section 6, and a resin raw material consisting of 70 parts by mass of styrene (ST), 30 parts by mass of acrylonitrile (AN), 0.014 parts by mass of 1,1-di(t-butylperoxy)cyclohexane (polymerization initiator), and 0.215 parts by mass of n-octyl mercaptan (chain transfer agent) was continuously supplied to the polymerization reactor 3 and polymerized continuously. At this time, the liquid amount in the polymerization reactor 3 and the supply rate of the resin raw material were set so that the residence time in the polymerization reactor 3 was 4 hours.

[0099] Based on the operational data listed in Operation Data No. 1 in Table 1 and the actually measured MFR data, a regression equation was calculated to predict the MFR using a soft sensor, and the MFR was predicted in real time based on this regression equation. Based on this predicted value, the temperature in the polymerization reactor was controlled in the range of 130 to 140°C, the pressure in the polymerization reactor in the range of 0.11 to 0.17 MPa, the amount of polymerization initiator fed in the range of 0.011 to 0.017 parts by mass, and the amount of chain transfer agent fed in the range of 0.213 to 0.217 parts by mass. The polymerization control was programmed in advance using the operation support automation package "Knowledge Power" (Azbil Corporation) and was automatically controlled. The measurement interval for each operation data was 60 seconds or less due to the automatic program. The operation was continued under the above conditions for one day, and the MFR of the produced resin was measured once every two hours. The results are shown in Table 2.

[0100] Polymer A-1 discharged from the polymerization reactor by a gear pump was subjected to devolatilization of unreacted materials in an extruder, and then the molten resin was discharged in the form of strands from the outlet of the extruder and granulated by a pelletizer to obtain resin pellets.

[0101] Example 2 The same procedure as in Example 1 was carried out, except that a regression equation for predicting the MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 2 in Table 1 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 2.

[0102] Comparative Example 1 The same procedure as in Example 1 was carried out, except that a regression equation for predicting the MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 3 in Table 1 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 2.

[0103] Example 3 The same procedure as in Example 1 was carried out, except that a resin raw material consisting of 72 parts by mass of methyl methacrylate (MMA), 24 parts by mass of styrene (ST), 4 parts by mass of acrylonitrile (AN), 0.014 parts by mass of 1,1-di(t-butylperoxy)cyclohexane (polymerization initiator), and 0.215 parts by mass of n-octyl mercaptan (chain transfer agent) was continuously supplied to the polymerization reactor 3. The results are shown in Table 2.

[0104] Comparative Example 2 The same procedure as in Example 3 was carried out, except that a regression equation for predicting MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 4 in Table 1 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 2.

[0105] Comparative Example 3 The same procedure as in Example 3 was carried out, except that in Example 3, the MFR was predicted in real time based on the operating data of operating data number 3 in Table 1. The results are shown in Table 2.

[0106] Comparative Example 4 The same procedure as in Example 3 was carried out except that the MFR was controlled without predicting it. The results are shown in Table 2.

[0107] Comparative Example 5 The same procedure as in Example 3 was carried out, except that in Example 3, the MFR was predicted in real time based on the operating data of operating data number 5 in Table 1. The results are shown in Table 2.

[0108] [Table 1]

[0109] [Table 2]

[0110] Examples 1 and 2 and Comparative Example 1 are examples in which AS resin was produced, but Examples 1 and 2 had higher accuracy in controlling the physical properties of the resin, and the resulting resin had smaller variations in the physical properties than Comparative Example 1. Similarly, Example 3 and Comparative Examples 2 to 5 are examples in which MAS resin was produced, but Example 3 had higher accuracy in controlling the physical properties of the resin, and the resulting resin had smaller variations in the physical properties than Comparative Examples 2 to 5.

[0111] Example 4 The resin production apparatus used was as shown in FIG. A resin raw material consisting of 70 parts by mass of styrene (ST), 30 parts by mass of acrylonitrile (AN), 0.014 parts by mass of 1,1-di(t-butylperoxy)cyclohexane (polymerization initiator), and 0.215 parts by mass of n-octyl mercaptan (chain transfer agent) was continuously supplied to a polymerization reactor 11 (volume 20 L) equipped with a helical ribbon blade as an agitator 10, and polymerized continuously to obtain a polymer A-9. Next, unreacted materials and the like were removed using a first extruder equipped with a vent as a first resin recovery section 14 and a second extruder equipped with a vent as a second resin recovery section 17. A third extruder was used as the resin addition section 19, and the graft copolymer B-1-1 of Reference Example 1 was connected to the middle of the second extruder and supplied from the third extruder so as to obtain the addition ratio shown in Table 3. After the graft copolymer B-1-1 was mixed in the latter stage of the second extruder, the molten resin was discharged in the form of strands from the outlet of the second extruder and granulated by a pelletizer as the granulation device 20 to obtain resin composition pellets.

[0112] Based on the operational data listed in operational data number 6 in Table 4 and the actually measured MFR data, a regression equation was calculated to predict the MFR using a soft sensor, and the MFR was predicted in real time based on this regression equation. Based on this predicted value, the temperature in the polymerization reactor was controlled in the range of 130 to 140°C, the pressure in the polymerization reactor in the range of 0.11 to 0.17 MPa, the amount of polymerization initiator fed in the range of 0.011 to 0.017 parts by mass, and the amount of chain transfer agent fed in the range of 0.213 to 0.217 parts by mass. The polymerization control was programmed in advance using the operation support automation package "Knowledge Power" (Azbil Corporation) and was automatically controlled. The measurement interval for each operation data was 60 seconds or less due to the automatic program.

[0113] The operation was continued under the above conditions for one day, and the MFR of the produced resin composition was measured once every two hours. The results are shown in Table 5.

[0114] Example 5 A resin raw material consisting of 72 parts by mass of methyl methacrylate (MMA), 24 parts by mass of styrene (ST), 4 parts by mass of acrylonitrile (AN), 0.014 parts by mass of 1,1-di(t-butylperoxy)cyclohexane (polymerization initiator), and 0.215 parts by mass of n-octyl mercaptan (chain transfer agent) was continuously supplied to the polymerization reactor 11 and polymerized continuously to obtain a polymer A-10, and the graft copolymer B-1-2 of Reference Example 2 was connected to the middle of the second extruder from the third extruder so as to have the addition ratio shown in Table 3, and was mixed with the graft copolymer B-1-2 at the rear of the second extruder. The same method as in Example 4 was used. The results are shown in Table 5.

[0115] Example 6 Using the same resin raw material and resin production equipment as in Example 5, a regression equation for predicting YI was calculated using a soft sensor based on each operation data listed in operation data number 7 in Table 4 and the actually measured YI data, and YI was predicted in real time based on this regression equation. Further, based on the calculated YI predicted value, the resin mixing section outlet temperature of the second extruder was controlled to 220 to 260°C, the heating temperature of the resin mixing section was controlled to 150 to 250°C, the resin pressure of the resin mixing section was controlled to 3 to 6 MPa, the vacuum degree in the resin mixing section was controlled to 20 to 100 Torr, and the screw rotation speed of the resin mixing section was controlled to 100 to 300 rpm, respectively, to obtain resin pellets in the same manner as in Example 1. The polymerization control was programmed in advance using the operation support automation package "Knowledge Power" (Azbil Corporation) as in Example 5, and was automatically controlled. The measurement interval of each operation data was 60 seconds or less due to the automatic program.

[0116] The operation was continued under the above conditions for one day, and the produced resin was sampled every two hours to measure the YI. The results are shown in Table 5.

[0117] Example 7 The same procedure as in Example 5 was carried out, except that a regression equation for predicting the MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 7 in Table 4 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 5.

[0118] Example 8 The resin production apparatus used was as shown in FIG. A polymerization reactor 3 (volume 20 L) equipped with a helical ribbon blade as the agitator 2 and a first extruder as the resin recovery section 6 were used, and a resin raw material consisting of 72 parts by mass of methyl methacrylate (MMA), 24 parts by mass of styrene (ST), 4 parts by mass of acrylonitrile (AN), 0.014 parts by mass of 1,1-di(t-butylperoxy)cyclohexane (polymerization initiator), and 0.215 parts by mass of n-octyl mercaptan (chain transfer agent) was continuously supplied to the polymerization reactor 3 and polymerized continuously. At this time, the liquid amount in the polymerization reactor 3 and the supply rate of the resin raw material were set so that the residence time in the polymerization reactor 3 was 4 hours. The polymer A-13 discharged from the polymerization reactor by the gear pump was subjected to devolatilization of unreacted matter in the first extruder, and then the molten resin was discharged in the form of strands from the outlet of the first extruder, and granulated by a pelletizer as the granulation device 8 to obtain pellets of a thermoplastic resin. The thermoplastic resin pellets and the graft copolymer B-1-2 were supplied from a gravimetric addition feeder serving as the resin addition section 21 to a fourth extruder serving as the resin mixing section 22 in the ratio shown in Table 3, and after mixing in a molten state, the molten resin was discharged in the form of strands from the extruder outlet and granulated by a pelletizer serving as the granulation device 23 to obtain pellets of the thermoplastic resin composition.

[0119] Based on the operating data listed as operating data number 7 in Table 4 and the actually measured MFR data, a regression equation was calculated to predict the MFR using a soft sensor, and the MFR was predicted in real time based on this regression equation. Based on this predicted value, the temperature in the polymerization reactor was controlled in the range of 130 to 140°C, the pressure in the polymerization reactor in the range of 0.11 to 0.17 MPa, the amount of polymerization initiator fed in the range of 0.011 to 0.017 parts by mass, and the amount of chain transfer agent fed in the range of 0.213 to 0.217 parts by mass. The polymerization control was programmed in advance using the operation support automation package "Knowledge Power" (Azbil Corporation) and was automatically controlled. The measurement interval for each operation data was 60 seconds or less due to the automatic program.

[0120] The operation was continued under the above conditions for one day, and the MFR of the produced resin was measured once every two hours. The results are shown in Table 5.

[0121] Comparative Example 6 The same procedure as in Example 5 was carried out, except that a regression equation for predicting the MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 8 in Table 4 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 5.

[0122] Comparative Example 7 The same procedure as in Example 5 was carried out, except that a regression equation for predicting the MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 9 in Table 4 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 5.

[0123] Comparative Example 8 The same procedure as in Example 5 was carried out, except that a regression equation for predicting MFR was calculated using a soft sensor based on each operational data listed in Operation Data No. 10 in Table 4 and the actually measured MFR data, and the MFR was predicted in real time based on this regression equation. The results are shown in Table 5.

[0124] Comparative Example 9 The same procedure as in Example 5 was carried out except that the MFR was controlled without predicting it. The results are shown in Table 5.

[0125] Comparative Example 10 The resin was produced for one day using the same resin raw material, production equipment, and operating conditions as in Example 6, and the resin was sampled every two hours to measure the YI. No prediction of the YI was performed during production. The results are shown in Table 5.

[0126] [Table 3]

[0127] [Table 4]

[0128] [Table 5]

[0129] As described above, in Examples 4 to 8, the physical properties of the resin compositions were controlled more precisely than in Comparative Examples 6 to 10, and the resulting resin compositions had smaller variations in the physical properties. [Explanation of symbols]

[0130] 1,5,9,13,16:Piping 2,10: Mixer 3,11: Polymerization reactor 4,12: Resin discharge device (gear pump) 6: Resin recovery section (first extruder) 7,15,18:Vent 8, 20, 23: Pelletizer 14: First resin recovery section (first extruder) 17: Second resin recovery section (second extruder) 19: Resin addition section (third extruder) 21: Resin addition section (weight-type addition feeder) 22: Resin mixing section (fourth extruder)

Claims

1. A method for producing a thermoplastic resin, comprising: (I) a polymerization step of supplying a resin raw material containing a monomer (a) to a polymerization reactor equipped with a stirrer and polymerizing the raw material to obtain a polymer (A) containing a thermoplastic resin; and (II) a recovery step of extracting the thermoplastic resin from the polymer (A), Calculating physical properties of the finally obtained thermoplastic resin using at least three pieces of continuous or intermittent operation data obtained in the step (I) and at least one piece of continuous or intermittent operation data obtained in the step (II); A method for producing a thermoplastic resin, comprising controlling at least one process variable among process variables that provide the operation data in the step (I) and the step (II) based on the calculated physical property, the monomer (a) is a monomer containing an aromatic vinyl monomer (a1) and a vinyl cyanide monomer (a2), or a monomer containing an aromatic vinyl monomer (a1), a vinyl cyanide monomer (a2), and an unsaturated carboxylic acid alkyl ester monomer (a3); A method for producing a thermoplastic resin, characterized in that at least three operational data used in the step (I) include a chain transfer agent concentration in the polymerization reactor, a polymerization initiator concentration in the polymerization reactor, and a liquid phase temperature in the polymerization reactor, and at least one operational data used in the step (II) includes an extruder power.

2. 2. The method for producing a thermoplastic resin according to claim 1, wherein the physical properties of the thermoplastic resin are at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI, and HAZE, which are measured by a method conforming to any one of JIS, ISO, and ASTM.

3. The method for producing a thermoplastic resin according to claim 1 or 2, characterized in that a soft sensor is used as a method for calculating the physical properties of the thermoplastic resin.

4. A method for producing a thermoplastic resin composition, comprising: producing a thermoplastic resin by the method for producing a thermoplastic resin according to any one of claims 1 to 3; and then (III) mixing the thermoplastic resin with a polymer (B) different from the polymer (A) in a molten state.

5. The method for producing a thermoplastic resin composition according to claim 4, wherein the polymer (B) is a graft copolymer (B1) obtained by graft polymerization of a monomer (b) containing an aromatic vinyl monomer (b1) and a vinyl cyanide monomer (b2) in the presence of a rubber-like polymer.

6. The method for producing a thermoplastic resin composition according to claim 5, wherein the monomer (b) further comprises a monomer (b3) copolymerizable with the aromatic vinyl monomer (b1) and the vinyl cyanide monomer (b2).

7. The method for producing a thermoplastic resin composition according to claim 6, wherein the monomer (b3) is an unsaturated carboxylic acid alkyl ester monomer.

8. The method for producing a thermoplastic resin composition according to any one of claims 4 to 7, characterized in that physical properties of the finally obtained thermoplastic resin composition are calculated using at least three pieces of continuous or intermittent operation data obtained in the step (I), at least one piece of continuous or intermittent operation data obtained in the step (II), and at least one piece of continuous or intermittent operation data obtained in the step (III), and at least one process variable among process variables that give the operation data in the steps (I), (II), and (III) is controlled based on the calculated physical properties.

9. The method for producing a thermoplastic resin composition according to claim 8, wherein at least one of the operational data used in the step (III) includes an extruder power.

10. 10. The method for producing a thermoplastic resin composition according to claim 8 or 9, wherein the physical property of the thermoplastic resin composition is at least one selected from the group consisting of tensile strength, flexural strength, Izod impact strength, Charpy impact strength, deflection temperature under load, MFR, YI, and HAZE, which are measured by a method conforming to any one of JIS, ISO, and ASTM.

11. The method for producing a thermoplastic resin composition according to any one of claims 8 to 10, characterized in that a soft sensor is used as a method for calculating physical properties of the thermoplastic resin composition.

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