JP2014012781A - Method for producing methacrylic polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a methacrylic polymer composition which can more efficiently produce a polymer composition suitable for obtaining a high-quality resin composition having high thermal stability and heat resistance.SOLUTION: In a method for producing a methacrylic polymer composition, a raw material mixture comprising a raw material monomer containing 50 mass% or more of a methyl methacrylate and a polymerization initiator is supplied from a supply port of a complete mixing type reaction tank to be subjected to continuous polymerization in the reaction tank, a polymer composition obtained by the continuous polymerization is extracted from an extraction port, and the temperature of the raw material mixture supplied to the reaction tank is from -50 to -10°C.

Description

  The present invention relates to a method for producing a methacrylic polymer composition and a molded body obtained from the composition.

  A polymer such as a methacrylic acid ester polymer is produced by continuous polymerization in which raw material monomers, a polymerization initiator and the like are continuously supplied to a reaction vessel and polymerized. As such a continuous polymerization method, a continuous solution polymerization method in which continuous polymerization is performed using a solvent (or a dispersion medium, the same applies hereinafter) and a continuous bulk polymerization method in which continuous polymerization is performed without using a solvent are known.

  As a method for producing a methacrylic polymer composition, for example, in Patent Documents 1 and 2, a raw material monomer mixed solution and a polymerization initiator mixed solution are supplied to a fully mixed reaction vessel, and a gas phase portion is formed in the reaction vessel. A method is disclosed in which continuous polymerization is carried out in an adiabatic state where no heat enters and exits from the outside.

  In recent years, the use of resin compositions composed of polymers such as methacrylic ester polymers has further expanded, and high-quality methacrylic polymer compositions (for example, excellent physical properties such as heat resistance and thermal stability, impurities There is a growing demand for more efficient production of polymer compositions) with less contamination. However, it has been found that conventional manufacturing methods are not necessarily sufficient to meet such demands.

JP-A-7-126308 JP 2006-104282 A

  An object of the present invention is to provide a method for producing a polymer composition capable of more efficiently producing a polymer composition suitable for obtaining a high-quality resin composition having high thermal stability and heat resistance. is there.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention.
That is, this invention consists of the following structures.
[Claim 1]
A raw material mixture containing a raw material monomer containing 50% by mass or more of methyl methacrylate and a polymerization initiator is supplied from a supply port of a complete mixing type reaction tank, subjected to continuous polymerization in the reaction tank, and the resulting weight A method for producing a methacrylic polymer composition in which a coalescence composition is extracted from an extraction port of the reaction tank,
The method for producing a methacrylic polymer composition, wherein the temperature of the raw material mixture supplied to the reaction vessel is -50 ° C to -10 ° C.
[Section 2]
Item 2. The method for producing a methacrylic polymer composition according to Item 1, wherein the outlet of the reaction vessel is located at the top of the reaction vessel.
[Section 3]
Item 3. The method for producing a methacrylic polymer composition according to Item 1 or 2, wherein the continuous polymerization is performed in an adiabatic state.
[Claim 4]
Item 4. The method for producing a methacrylic polymer composition according to any one of Items 1 to 3, wherein the polymerization temperature in the continuous polymerization is 120 ° C to 150 ° C.
[Section 5]
Item 5. The method for producing a methacrylic polymer composition according to any one of Items 1 to 4, wherein the continuous polymerization is continuous bulk polymerization.
[Claim 6]
The molded object obtained from the methacrylic polymer composition obtained by the manufacturing method in any one of claim | item 1 -5.
[Claim 7]
Item 7. The molded body according to Item 6, wherein the molded body is a light guide plate.

  According to the polymerization method of the present invention, a methacrylic polymer composition suitable for obtaining a methacrylic resin composition having high thermal stability and heat resistance can be produced with high productivity.

Schematic of the manufacturing apparatus of the polymer composition in one embodiment of this invention.

The production method of the polymer composition of the present invention is carried out using a fully mixed reaction vessel, and continuous polymerization, for example, continuous bulk polymerization or continuous solution polymerization can be carried out in the reaction vessel.
Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. First, the apparatus used in order to implement the manufacturing method of the polymer composition of this embodiment is demonstrated.

The method for producing the polymer composition of the present embodiment is carried out using a fully mixed reaction tank 10. In the present embodiment, the reaction vessel 10 is used to perform continuous bulk polymerization as continuous polymerization.
More specifically, the reaction vessel 10 has a supply port 11a and an extraction port 11b. Preferably, the reaction vessel 10 agitates the jacket 13 and the contents as temperature adjusting means for adjusting the temperature of the outer wall surface of the reaction vessel. And a stirrer 14 for the purpose. Although the extraction port 11b is provided so that it may be located in the top part of the reaction tank 10 in this embodiment, it is not limited to this. On the other hand, although the supply port 11a does not limit this embodiment, generally it can be provided in the appropriate position of the downward direction of each reaction tank. Furthermore, the reaction vessel 10 includes a temperature sensor T as temperature detection means for detecting the temperature in the reaction vessel.

  The stirrer 14 is for making the inside of the reaction tank substantially completely mixed. These agitators may be equipped with any appropriate agitating blade, such as a MIG wing, a Max blend wing (registered trademark, manufactured by Sumitomo Heavy Industries, Ltd.), a paddle wing, a double helical ribbon wing, a full zone. Wings (registered trademark, manufactured by Shinko Environmental Solution Co., Ltd.) may be provided. In order to increase the stirring effect in the reaction vessel, it is desirable to attach a baffle in the reaction vessel. However, the present embodiment is not limited to this, and may have any appropriate configuration in place of the stirrer 14 as long as the inside of the reaction vessel can be substantially completely mixed.

Although the reaction tank 10 is generally preferable as the stirring efficiency is higher, the stirring power should not be larger than necessary from the viewpoint of not adding an excessive amount of heat to the reaction tank by the stirring operation. Although stirring power is not specifically limited, Preferably, it is 0.5-30 kW / m < ³ >, More preferably, it is 1-15 kW / m < ³ >. The stirring power is preferably set larger as the viscosity of the reaction system is higher (or as the content of the polymer in the reaction system is higher).

  As shown in the figure, the supply port 11a of the reaction vessel 10 is connected to a raw material monomer tank (raw material monomer supply) 1 through a raw material monomer supply line (pipe) 4 and a raw material supply line 9, and a polymerization initiator tank ( A polymerization initiator and optionally a raw material monomer supply source 3 are connected to a polymerization initiator supply line (pipe) 6 and a raw material supply line 9. On the raw material monomer supply line 4 and the polymerization initiator supply line 6, monomer supply means (pump 5) and initiator supply means (pump 7) are provided, respectively. In the present embodiment, the supply source of the raw material monomer and the polymerization initiator to the reaction vessel 10 is the raw material monomer tank 1 and the polymerization initiator tank 3, but the number of raw material monomers and the supply source of the polymerization initiator, the raw material monomer, and The aspect of the polymerization initiator (for example, the composition in the case of a mixture) is not particularly limited as long as the raw material monomer and the polymerization initiator can be appropriately supplied to the reaction vessel 10. The extraction port 11 b of the reaction tank 10 is connected to the extraction line 15.

  As the monomer supply means and the initiator supply means, for example, a pump 5 for introducing the raw material monomer from the supply port 11a into the reaction tank 10, and a polymerization initiator for introducing the polymerization initiator into the reaction tank 10 from the supply port 11a. A pump 7 is mentioned. The pumps 5 and 7 are not particularly limited, but are preferably pumps capable of setting the flow rates from the raw material monomer tank 1 and the polymerization initiator tank 3 to constant amounts. Specifically, a multiple reciprocating pump is preferable, and a non-pulsating constant pump such as a double non-pulsating metering pump or a triple non-pulsating metering pump is more preferable. Thereby, the supply amount (or supply flow rate, the same applies hereinafter) of the raw material monomer and the polymerization initiator to the reaction vessel 10 can be controlled.

  At least one selected from the group consisting of a raw material monomer tank 1, a polymerization initiator tank 3, a raw material monomer supply line 4, a polymerization initiator supply line 6 and a raw material supply line 9 [hereinafter sometimes referred to as a tank and / or a line. ] Includes temperature adjusting means. The raw material monomer tank 1 and / or the polymerization initiator tank 3 may include, for example, a jacket that at least partially covers the outer wall surface of the tank as temperature adjusting means. The temperature of the raw material monomer in the polymerization initiator tank 3 can be adjusted. In the case where the raw material monomer tank 1 and / or the polymerization initiator tank 3 are provided with a jacket, a stirring and mixing means for stirring the raw material monomer and / or the polymerization initiator in the tank is more effective in adjusting the temperature. Is preferably further provided. Further, at least one selected from the group consisting of the raw material monomer supply line 4, the polymerization initiator supply line 6 and the raw material supply line 9 is a temperature control means, for example, a jacket that covers at least a part of the line, or a line. It may be equipped with a heat medium bath that can be at least partially immersed, a heating / cooling device that replaces a part of the line, a trace pipe that passes the heat medium, etc. Understandably, such temperature adjusting means can adjust at least one temperature selected from the group consisting of raw material monomers flowing in the line, polymerization initiators and mixtures thereof. As the heating / cooling device, a heating / cooling device having both temperature adjusting means and mixing means, specifically, one having a dynamic mixing function (for example, a screw mixer capable of cooling a cylinder), static Those having a mixing function (for example, a heat exchanger with a built-in static mixer) may be used. When at least one selected from the group consisting of the raw material monomer supply line 4, the polymerization initiator supply line 6 and the raw material supply line 9 includes a heating / cooling device, the heating / cooling device is provided on the line in any appropriate manner. In addition, the line portion other than the heating / cooling device may be kept warm by being covered with a heat insulating material, or may be cooled in combination with a jacket surrounding the outer wall surface of the line. Thus, the temperature of the raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 can be adjusted by using the temperature adjusting means provided in the tank and / or the line.

  Each member described above with reference to FIG. 1 is preferably connected as appropriate to a control means (not shown), which will be described later, and is configured as a whole so that its operation can be controlled by the control means. Thereby, the temperature of the outer wall surface of the reaction tank set with respect to the jacket (temperature control means) 13 and the temperature in the reaction tank detected by the temperature sensor (temperature detection means) T are the same for the reaction tank 10. As described above (in other words, to achieve an adiabatic state in the reaction vessel 10), by adjusting the operation of the pumps 5 and 7, the supply amount of the raw material monomer and the polymerization initiator to the reaction vessel 10 is adjusted. Alternatively, the temperature of the outer wall surface of the reaction vessel set for the jacket 13 can be adjusted.

  The jacket 13 covers substantially the entire reaction tank 10, and heats the reaction tank 10 appropriately by introducing a heat medium such as steam, hot water, or an organic heat medium from a heat medium supply path (not shown). Or keep warm. The temperature of the jacket 13 can be appropriately adjusted depending on the temperature or pressure of the supplied heat medium. The heat medium introduced into the jacket 13 is removed from a heat medium discharge path (not shown). The temperature and pressure of the jacket 13 are detected by a sensor such as a temperature sensor (not shown) provided on the heat medium discharge path. The location of the sensor such as the temperature sensor is not particularly limited, and may be, for example, on the heat medium supply path or in the jacket 13. A jacket that can be provided as a temperature control means in the tank and / or the line may have the same configuration as the jacket 13. Although this embodiment is not limited, typically, at least one selected from the group consisting of the raw material monomer supply line 4, the polymerization initiator supply line 6 and the raw material supply line 9 may be a double tube. The inner space of the inner tube serves as a flow path for the raw material monomer, the polymerization initiator or a mixture thereof, and the space between the inner pipe and the outer pipe serves as a flow path (jacket) for the heat medium.

  The polymerization reaction in the reaction vessel 10 is required to be carried out at a substantially constant polymerization temperature in the reaction vessel 10 from the viewpoint of making the quality of the polymer (polymer) produced constant. Therefore, the temperature adjusting means (jacket 13) is controlled to a preset constant temperature so that the internal temperature of the reaction vessel 10 can be kept substantially constant.

  The set temperature of the temperature adjusting means (jacket 13) is transmitted to a control means to be described later for determining whether or not the supply flow rate control by the monomer supply means (pump 5) or the initiator supply means (pump 7) is necessary. It becomes data. The set temperature of the temperature adjusting means (jacket 13) can be adjusted by controlling the temperature or pressure of the heating medium.

Examples of the control means include a control unit (not shown) including a CPU, a ROM, a RAM, and the like.
The ROM of the control unit is a device for storing a program for controlling the pumps 5 and 7, etc., and the RAM of the control unit is used for executing the program in the reaction tank 10 detected by the temperature sensor T. Is a device that temporarily stores temperature data of the above, data of temperature setting of the jacket 13, and data of temperature setting of the temperature adjusting means provided in the tank and / or line.
The CPU of the control unit executes the program stored in the ROM based on the temperature data in the reaction tank 10 and the set temperature data of the jacket 13 stored in the RAM, and enters the reaction tank 10. The supply flow rate of the raw material monomer and / or the polymerization initiator is controlled by the monomer supply means (pump 5) and / or the initiator supply means (pump 7). For the jacket and / or heating / cooling device provided as temperature adjusting means in the tank and / or the line, the CPU of the control unit stores the temperature data in the reaction tank 10 stored in the RAM, the tank and / or Alternatively, a program stored in the ROM (based on the set temperature data of the jacket and / or heater / cooler provided in the line, and the temperature in the tank and / or the line when actually measured ( (It may be a part of the above program or a different program from the above program) to adjust the set temperature of the jacket and / or heater / cooler provided in the tank and / or line obtain.

An example of control by the control means (control unit) is shown below.
When the temperature in the reaction vessel 10 detected by the temperature sensor T exceeds the set temperature of the jacket 13 which is a temperature adjusting means, the CPU executes the program in the ROM, for example, into the reaction vessel 10. The pump 7 is controlled so as to reduce the supply flow rate of the polymerization initiator. By executing such control, the heat of polymerization generated in the reaction vessel 10 can be reduced, and as a result, the temperature in the reaction vessel 10 can be lowered.

  On the other hand, when the temperature of the reaction vessel 10 is lower than the set temperature of the jacket 13, for example, the supply flow rate of the polymerization initiator into the reaction vessel 10 is increased by executing the program in the ROM by the CPU. The pump 7 is controlled. By executing such control, the heat of polymerization generated in the reaction vessel 10 can be increased, and as a result, the temperature in the reaction vessel 10 can be increased.

Further, for example, in the polymerization reaction in the reaction tank 10, when the total supply flow rate into the reaction tank 10 is remarkably reduced as a result of controlling the pump 7, the supply flow rate of the polymerization initiator is controlled by controlling the pump 7. It is preferable to increase the supply flow rate of the raw material monomer by controlling the pump 5 at the same time, in addition to reducing it.
Furthermore, the following control is mentioned as another control example. That is, when the temperature in the reaction vessel 10 detected by the temperature sensor T exceeds the set temperature of the jacket 13 that is a temperature adjusting means, the supply flow rate of the raw material monomer is increased by controlling the pump 5 to react. The relative supply flow rate of the polymerization initiator into the tank 10 is decreased. Also by such control, the temperature in the reaction vessel 10 can be lowered.

The ratio between the supply flow rate of the raw material monomer and the supply flow rate of the polymerization initiator may be appropriately set according to the type of polymer to be produced, the type of polymerization initiator to be used, and the like.
In addition, the supply flow rate of the raw material monomer and the extent to increase or decrease the supply flow rate of the polymerization initiator are appropriately set according to the type of polymer to be generated (polymer), the type of polymerization initiator to be used, and the like. Is. However, when what is supplied into the reaction vessel 10 by the initiator supply means is not a polymerization initiator alone but a raw material monomer containing a polymerization initiator, the supply flow rate of the polymerization initiator is the polymerization initiator It is necessary to control in consideration of the content ratio of the polymerization initiator in the raw material monomer to be included.

  The set temperature of the jacket provided in the tank and / or the line can be adjusted, for example, by controlling the flow rate and / or temperature of the heat medium flowing through the jacket. The set temperature of the heating / cooling device provided in the tank and / or the line is, for example, when a heat exchanger is used as the heating / cooling device (not shown), generally of the heat medium flowing through the heat exchanger. It can be adjusted by controlling the flow rate and / or temperature. In the tank and / or the line, a temperature sensor (temperature detecting means) for detecting the temperature of the raw material monomer and / or the polymerization initiator stored in the tank, and a temperature for detecting the temperature of the fluid flowing in the line A temperature sensor (temperature detection means) is appropriately installed.

  Further, although not essential to the present embodiment, a preheater 21 and a devolatilizing extruder 23 may be disposed downstream of the extraction line 15. A pressure regulating valve (not shown) can be provided between the preheater 21 and the devolatilizing extruder 23. The extrudate after devolatilization is taken out from the take-out line 25.

  Any suitable heater can be used as the preheater 21 as long as the viscous fluid can be heated. The devolatilizing extruder 23 may be a screw type single-screw or multi-screw devolatilizing extruder.

  Further, there may be a recovery tank 27 for storing raw material monomers separated and recovered from volatile components (mainly comprising unreacted raw material monomers) separated by the devolatilizing extruder 23.

  Next, the manufacturing method of the polymer composition implemented using this apparatus is demonstrated. In this embodiment, as an example, a case where a methacrylic ester monomer is continuously polymerized, in other words, a case where a methacrylic ester polymer is produced will be described, but the present invention is not limited thereto.

-Preparation First, raw material monomers and a polymerization initiator are prepared.

In this embodiment, a raw material monomer containing 50% by mass or more of methyl methacrylate is used as the raw material monomer.
As a raw material monomer, for example,
・ Methyl methacrylate alone, or ・ Methyl methacrylate 50% by mass or more (preferably 70% by mass or more, more preferably 90% by mass or more) and other vinyl monomers copolymerizable with this 50% by mass or less ( Preferably 30% by mass or less, more preferably 10% by mass or less) (however, the total of methyl methacrylate and other vinyl monomers copolymerizable therewith is 100% by mass). Can be mentioned.

  Examples of the copolymerizable vinyl monomer include a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having two or more radical polymerizable double bonds. It is done. Specifically, as a monofunctional monomer having one radical polymerizable double bond, for example, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-methacrylic acid t- Methacrylic acid esters such as butyl, sec-butyl methacrylate, isobutyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. Acrylic acid esters of; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride or their anhydrides; 2-hydroxyethyl acrylate, 2-hydroxy acrylate Propyl, acrylic acid Hydroxyl group-containing monomers such as glycerol, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, monoglycerol methacrylate; nitrogen such as acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, diacetone acrylamide, dimethylaminoethyl methacrylate Containing monomers; Epoxy group-containing monomers such as allyl glycidyl ether, glycidyl acrylate and glycidyl methacrylate; and styrene monomers such as styrene and α-methylstyrene. Examples of the polyfunctional monomer having two or more double bonds capable of radical polymerization include unsaturated carboxylic acid diesters of glycols such as ethylene glycol dimethacrylate and butanediol dimethacrylate; allyl acrylate, allyl methacrylate, Alkenyl esters of unsaturated carboxylic acids such as allyl cinnamate; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate; multivalents such as trimethylolpropane triacrylate Unsaturated carboxylic acid ester of alcohol; divinylbenzene. The above exemplified copolymerizable vinyl monomers may be used singly or in combination of two or more.

In this embodiment, for example, a radical initiator is used as the polymerization initiator.
Examples of the radical initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, azobiscyclohexanenitrile, 1,1′-azobis (1-acetoxy-1-phenylethane), dimethyl 2,2′-azo. Azo compounds such as bisisobutyrate and 4,4′-azobis-4-cyanovaleric acid; benzoyl peroxide, lauroyl peroxide, acetyl peroxide, caprylyl peroxide, 2,4-dichlorobenzoyl peroxide, isobutyl peroxide Oxide, acetylcyclohexylsulfonyl peroxide, t-butylperoxypivalate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t-butylperoxy-2-ethylhexanoate, 1 , 1-Di ( -Butylperoxy) cyclohexane, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane , Diisopropyl peroxydicarbonate, diisobutylperoxydicarbonate, di-sec-butylperoxydicarbonate, di-n-butylperoxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, bis (4-t- Butylcyclohexyl) peroxydicarbonate, t-amylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-ethylhexanoate, 1,1,2-trimethylpropylperoxy 2-ethylhexanoate, t-butyl peroxy Isopropyl monocarbonate, t-amyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl carbonate, t-butyl peroxyallyl carbonate, t-butyl peroxyisopropyl carbonate, 1,1,3,3-tetramethyl Butyl peroxyisopropyl monocarbonate, 1,1,2-trimethylpropyl peroxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutyl peroxyisononate, 1,1,2-trimethylpropylperoxy-isononate And organic peroxides such as t-butyl peroxybenzoate.
These polymerization initiators may be used alone or in a combination of two or more.

A polymerization initiator is selected according to the kind of polymer (polymer) to produce | generate and the raw material monomer to be used. For example, although the present invention is not particularly limited, the polymerization initiator (radical initiator) is a polymerization initiator having a half-life of τ (seconds) at the polymerization temperature and an average residence time in the reaction vessel of θ ( As the second), τ / θ (−) is, for example, 0.1 or less, preferably 0.02 or less, more preferably 0.01 or less. If the value of τ / θ is less than this value, the polymerization initiator is sufficiently decomposed (and thus generates radicals) in the reaction vessel, and the polymerization reaction can be effectively started.
The supply amount of the polymerization initiator (radical initiator) is not particularly limited, but is usually 0.001 to 1% by weight with respect to the raw material monomer (the raw material monomer finally supplied to the reaction vessel 10). It is.

  In addition to the above raw material monomers and polymerization initiator, any appropriate other components such as chain transfer agents, release agents, rubbery polymers such as butadiene and styrene butadiene rubber (SBR), heat stabilizers, ultraviolet rays Absorbents may be used. Chain transfer agents are used to adjust the molecular weight of the polymer produced. A mold release agent is used in order to improve the moldability of the resin composition obtained from a polymer composition. A heat stabilizer is used in order to suppress thermal decomposition of the produced polymer. An ultraviolet absorber is used in order to suppress deterioration by the ultraviolet-ray of the polymer to produce | generate.

  The chain transfer agent may be a monofunctional or polyfunctional chain transfer agent. Specifically, for example, n-propyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, t-butyl mercaptan, n-hexyl mercaptan, n-octyl mercaptan, 2-ethylhexyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, etc. Alkyl mercaptans such as phenyl mercaptan and thiocresol; mercaptans having 18 or less carbon atoms such as ethylene thioglycol; ethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, Polyhydric alcohols such as sorbitol; hydroxyl group esterified with thioglycolic acid or 3-mercaptopropionic acid, 1,4- Tetrahydronaphthalene, 1,4,5,8-tetrahydronaphthalene, beta-terpinene, terpinolene, 1,4-cyclohexadiene, and the like hydrogen sulfide. These may be used alone or in combination of two or more.

  The supply amount of the chain transfer agent is not particularly limited because it varies depending on the type of chain transfer agent used. For example, when mercaptans are used, the raw material monomer (finally the reaction tank) Is preferably 0.01 to 3% by weight, and more preferably 0.05 to 1% by weight, based on the raw material monomer supplied to 10).

  The release agent is not particularly limited, and examples thereof include higher fatty acid esters, higher aliphatic alcohols, higher fatty acids, higher fatty acid amides, and higher fatty acid metal salts. In addition, only 1 type may be sufficient as a mold release agent, and 2 or more types may be sufficient as it.

  Specific examples of the higher fatty acid ester include, for example, methyl laurate, ethyl laurate, propyl laurate, butyl laurate, octyl laurate, methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, palmitate Octyl acid, methyl stearate, ethyl stearate, propyl stearate, butyl stearate, octyl stearate, stearyl stearate, myristyl myristate, methyl behenate, ethyl behenate, propyl behenate, butyl behenate, octyl behenate Saturated fatty acid alkyl esters such as methyl oleate, ethyl oleate, propyl oleate, butyl oleate, octyl oleate, methyl linoleate, ethyl linoleate, propyl linoleate, Unsaturated fatty acid alkyl esters such as butyl acrylate and octyl linoleate; lauric acid monoglyceride, lauric acid diglyceride, lauric acid triglyceride, palmitic acid monoglyceride, palmitic acid diglyceride, palmitic acid triglyceride, stearic acid monoglyceride, stearic acid diglyceride, stearic acid Saturated fatty acid glycerides such as triglyceride, behenic acid monoglyceride, behenic acid diglyceride, behenic acid triglyceride; unsaturated fatty acid glycerides such as oleic acid monoglyceride, oleic acid diglyceride, oleic acid triglyceride, linoleic acid monoglyceride, linoleic acid diglyceride, linoleic acid triglyceride It is done. Among these, methyl stearate, ethyl stearate, butyl stearate, octyl stearate, stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride and the like are preferable.

  Specific examples of the higher aliphatic alcohol include saturated aliphatic alcohols such as lauryl alcohol, palmityl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, myristyl alcohol, cetyl alcohol; oleyl alcohol, linolyl alcohol, and the like. Examples include unsaturated fatty alcohols. Of these, stearyl alcohol is preferred.

  Specific examples of higher fatty acids include, for example, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and 12-hydroxyoctadecanoic acid. Fatty acids; unsaturated fatty acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, cetreic acid, erucic acid, ricinoleic acid and the like.

  Specific examples of the higher fatty acid amide include saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide, and behenic acid amide; unsaturated fatty acid amides such as oleic acid amide, linoleic acid amide, and erucic acid amide. Amides; Amides such as ethylene bislauric acid amide, ethylene bispalmitic acid amide, ethylene bisstearic acid amide, and N-oleyl stearamide Of these, stearic acid amide and ethylenebisstearic acid amide are preferable.

  Examples of the higher fatty acid metal salt include sodium salts, potassium salts, calcium salts and barium salts of the higher fatty acids described above.

  The amount of the release agent used is preferably adjusted to be 0.01 to 1.0 part by weight with respect to 100 parts by weight of the polymer (polymer) contained in the obtained polymer composition. It is more preferable to adjust so that it may become 01-0.50 weight part.

  The heat stabilizer is not particularly limited, and examples thereof include phosphorus heat stabilizers and organic disulfide compounds. Of these, organic disulfide compounds are preferred. In addition, only 1 type may be sufficient as a heat stabilizer, and 2 or more types may be sufficient as it.

  Examples of the phosphorus-based heat stabilizer include tris (2,4-di-t-butylphenyl) phosphite, 2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [d. , F] [1,3,2] dioxaphosphin-6-yl] oxy] -N, N-bis [2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) Dibenzo [d, f] [1,3,2] dioxaphosphin-6-yl] oxy] -ethyl] ethanamine, diphenyltridecyl phosphite, triphenyl phosphite, 2,2-methylenebis (4,6 -Di-tert-butylphenyl) octyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, and the like. Among these, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite is preferable.

  Examples of organic disulfide compounds include dimethyl disulfide, diethyl disulfide, di-n-propyl disulfide, di-n-butyl disulfide, di-sec-butyl disulfide, di-tert-butyl disulfide, di-tert-amyl disulfide, dicyclohexyl. Examples thereof include disulfide, di-tert-octyl disulfide, di-n-dodecyl disulfide, di-tert-dodecyl disulfide and the like. Among these, di-tert-alkyl disulfide is preferable, and di-tert-dodecyl disulfide is more preferable.

  It is preferable that the usage-amount of a heat stabilizer is 1-2000 weight ppm with respect to the polymer (polymer) contained in the polymer composition obtained. When molding a polymer composition (more specifically, a resin composition after devolatilization) in order to obtain a molded body from the polymer composition of the present invention, the molding temperature is set high for the purpose of increasing molding efficiency. In such a case, it is more effective to add a heat stabilizer.

  Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, benzotriazole ultraviolet absorbers, malonic ester ultraviolet absorbers, and oxalanilide ultraviolet absorbers. An ultraviolet absorber may be used independently and may be used in combination of 2 or more type. Among these, benzotriazole type ultraviolet absorbers, malonic acid ester type ultraviolet absorbers, and oxalanilide type ultraviolet absorbers are preferable.

  Examples of the benzophenone-based UV absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-octyloxybenzophenone, Examples include 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone.

  Examples of the cyanoacrylate ultraviolet absorber include ethyl 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, and the like.

  Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole and 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl). ) -2H-benzotriazole, 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-pentyl-2- Hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (2H-benzotriazol-2-yl) -4-methyl- 6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzoto Azoles and the like.

  As the malonic acid ester ultraviolet absorber, 2- (1-arylalkylidene) malonic acid esters are usually used, and examples thereof include 2- (paramethoxybenzylidene) malonic acid dimethyl.

  As the oxalanilide ultraviolet absorber, 2-alkoxy-2'-alkyloxalanilides are usually used, and examples thereof include 2-ethoxy-2'-ethyloxalanilide.

  It is preferable that the usage-amount of a ultraviolet absorber is 5-1000 weight ppm with respect to the polymer (polymer) contained in the polymer composition obtained.

  In the raw material monomer tank 1, the above raw material monomers (methyl methacrylate alone or a mixture with a copolymerizable vinyl monomer) are appropriately mixed (optionally together with other components such as a chain transfer agent). Further, in the polymerization initiator tank 3, the polymerization initiator as described above is appropriately mixed with the raw material monomer (and optionally other components such as a chain transfer agent) as necessary. The polymerization initiator tank 3 may store the polymerization initiator alone or in the form of a mixture of the raw material monomer and the polymerization initiator (which may further include other components such as a chain transfer agent in some cases). However, it is preferably stored in the form of a mixture of the raw material monomer and the polymerization initiator.

-Polymerization process From the raw material monomer tank 1 and the polymerization initiator tank 3 which are the supply sources of a raw material monomer and a polymerization initiator, a raw material monomer and a polymerization initiator are continuously supplied to the reaction tank 10 from the supply port 11a. Specifically, the raw material monomer is supplied from the raw material monomer tank 1 by the pump 5 and the polymerization initiator tank 3 is supplied with a polymerization initiator (preferably a mixture of the raw material monomer and the polymerization initiator. The raw material mixture containing the raw material monomer and the polymerization initiator is continuously supplied to the reaction tank 10 from the supply port 11a. In the present invention, the raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 is the raw material monomer, the polymerization initiator, and possibly a chain transfer agent that are finally supplied to the reaction vessel 10. Refers to a mixture containing other ingredients.

  In the supply of the polymerization initiator to the reaction vessel 10, when a mixture of the raw material monomer and the polymerization initiator is prepared and supplied to the polymerization initiator tank 3, the raw material monomer supply flow rate A (kg / kg) from the raw material monomer tank 1 is supplied. h) and a supply flow rate B (kg / h) of a mixture of the raw material monomer and the polymerization initiator from the polymerization initiator tank 3 (the content of the polymerization initiator is 0.002 to 10% by weight); The ratio A: B is preferably adjusted to be in the range of 80:20 to 98: 2.

  In the production method of the present invention, the temperature of the raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 is adjusted to −50 ° C. to −10 ° C. The temperature is preferably -40 to -15 ° C. When this temperature is lower than −50 ° C., the moisture in the raw material monomer or the raw material monomer itself may be solidified, or the polymerization initiator, other additives, etc. may be precipitated. When this temperature is higher than −10 ° C., it is necessary to increase the polymerization temperature in order to increase the polymerization rate. In that case, the thermal stability and heat resistance of the finally obtained resin composition may be reduced. is there. Also, if the polymerization temperature is to be kept low when this temperature is higher than −10 ° C., it is necessary to cool the reaction vessel strongly with a jacket or the like. There is a possibility that the quality of the resin composition obtained will be reduced.

  The temperature of the raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 can be adjusted by the temperature adjusting means provided in the tank and / or the line as described above. As a method for supplying the raw material mixture at −50 ° C. to −10 ° C. to the reaction vessel 10, specifically, (I) raw material monomer stored in the raw material monomer tank 1 and polymerization stored in the polymerization initiator tank 3 The temperature of each of the initiators is adjusted to −50 ° C. to −10 ° C., and the raw material monomer supply line 4, the polymerization initiator supply line 6 and the raw material supply line 9 are kept warm by the temperature adjusting means and / or the heat insulating material. A method of supplying a raw material mixture containing a polymerization initiator to the reaction vessel 10, and (II) a raw material monomer tank 1 so that the temperature of the raw material mixture at the supply port 11a of the reaction vessel 10 is -50 ° C to -10 ° C. The temperature of the raw material monomer and the polymerization initiator stored in the polymerization initiator tank 3 and the supply flow rate of the raw material monomer and the polymerization initiator are adjusted. (III) The raw material monomer supply line 4, the polymerization initiator supply line 6, and the raw material supply line 9 are formed so that the temperature of the raw material mixture at the supply port 11 a of the reaction vessel 10 is −50 ° C. to −10 ° C. A method of adjusting the temperature of the temperature adjusting means provided in at least one selected from the group, (IV) so that the temperature of the raw material mixture at the supply port 11a of the reaction tank 10 is −50 ° C. to −10 ° C. Each temperature of the raw material monomer stored in the raw material monomer tank 1 and the polymerization initiator stored in the polymerization initiator tank 3, and the group consisting of the raw material monomer supply line 4, the polymerization initiator supply line 6 and the raw material supply line 9 Examples thereof include a method of adjusting the temperature of the temperature adjusting means provided in at least one selected. In the methods (II), (III) and (IV), the temperature of the raw material mixture is actually measured by a temperature detecting means for detecting the temperature in the raw material supply line 9 in the vicinity of the supply port 11a of the reaction vessel 10. It is preferable to measure in

  The raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 as described above is subjected to continuous polymerization, in this embodiment, continuous bulk polymerization (in other words, polymerization without a solvent). Is done. This polymerization may be performed so long as the polymerization reaction proceeds halfway, and the polymer composition (or polymerization syrup) is continuously extracted from the extraction port 11 b of the reaction vessel 10.

  Continuous polymerization may be performed in a state where the reaction vessel is filled with the reaction mixture and substantially no gas phase is present (hereinafter referred to as “full liquid state”). This is particularly suitable for continuous bulk polymerization. Due to this full liquid state, there is a problem that the gel adheres to the inner wall surface of the reaction vessel and grows, and a problem that the quality of the finally obtained polymer composition is deteriorated when this gel is mixed into the reaction mixture. Can be prevented in advance. Furthermore, this full liquid state can effectively utilize the entire volume of the reaction tank in the reaction space, and thus high production efficiency can be obtained.

  The full liquid state can be realized simply by continuously supplying and withdrawing the reaction tank 10 by positioning the extraction port 11b of the reaction tank 10 at the top of the reaction tank as in this embodiment. The position of the outlet at the top of the reaction vessel is particularly suitable for continuous polymerization of methacrylic acid ester monomers.

  Continuous polymerization can be carried out in an adiabatic state (a state in which there is substantially no heat in and out of the reaction vessel). This is particularly suitable for continuous bulk polymerization. Due to this heat insulation state, there is a problem that the gel adheres to the inner wall surface of the reaction vessel and grows, and a problem that the quality of the finally obtained polymer composition is deteriorated when this gel is mixed into the reaction mixture. Occurrence can be prevented in advance. Furthermore, this adiabatic state can stabilize the polymerization reaction and can provide self-controllability for suppressing the runaway reaction.

  The heat insulation state can be realized by making the temperature inside the reaction vessel 10 and the temperature of the outer wall surface thereof substantially equal. Specifically, the temperature of the outer wall surface of the reaction tank 10 set for the jacket (temperature adjusting means) 13 and the temperature sensor (temperature detecting means) T using the above-described control means (not shown). The supply amounts of the raw material monomer and the polymerization initiator to the reaction tank 10 can be realized by adjusting the operations of the pumps 5 and 7 so that the detected temperature in the reaction tank 10 matches. If the temperature of the outer wall surface of the reaction tank is set too high compared to the temperature in the reaction tank, it is not preferable because extra heat is applied to the reaction tank. It is preferable that the temperature difference between the inside of the reaction tank and the outer wall surface of the reaction tank is as small as possible.

  The heat of polymerization and heat of stirring generated in the reaction vessel 10 are usually carried away when the polymer composition is extracted from the reaction vessel 10. The amount of heat carried away by the polymer composition is determined by the flow rate of the polymer composition, the specific heat, and the temperature of the polymerization reaction.

  The temperature of the continuous polymerization is understood as the temperature in the reaction vessel 10 (detected by the temperature sensor T). The continuous polymerization is carried out at a temperature within the range of 120 to 150 ° C., for example, preferably at a temperature within the range of 130 to 150 ° C. However, it should be noted that the temperature in the reaction vessel may vary depending on various conditions until a steady state is reached.

  The pressure of continuous polymerization is understood as the pressure in the reaction vessel 10. This pressure is set to a pressure equal to or higher than the vapor pressure of the raw material monomer at the temperature in the reaction vessel so that no gas of the raw material monomer is generated in the reaction vessel, and is usually about 1.0 to 2.0 MPa in gauge pressure. .

  The time subjected to continuous polymerization is understood as the average residence time of the reaction vessel 10. The average residence time in the reaction vessel 10 can be set according to the production efficiency of the polymer in the polymer composition and is not particularly limited, but is, for example, 15 minutes to 6 hours. The average residence time in the reaction tank 10 can be adjusted by changing the supply amount (supply flow rate) of the raw material monomer and the like to the reaction tank 10 using the pumps 5 and 7, but greatly depends on the volume of the reaction tank 10.

  As described above, the polymer composition is continuously extracted from the extraction port 11b of the reaction vessel 10. The obtained polymer composition comprises the produced polymer and unreacted raw material monomers, and may further contain an unreacted polymerization initiator, a polymerization initiator decomposition product, and the like.

  Although the polymerization rate in a polymer composition does not limit this embodiment, it is 30 to 90 weight%, for example. The polymerization rate in the polymer composition generally corresponds to the polymer (polymer) content in the polymer composition. The higher the polymerization rate, the higher the productivity of the polymer. However, the viscosity of the polymer composition increases, and a large stirring power is required. Further, the lower the polymerization rate, the lower the productivity of the polymer and the greater the burden for recovering unreacted raw material monomers. Therefore, it is preferable to set an appropriate polymerization rate as a target or a guide.

  Generally, the higher the polymerization temperature, the lower the syndiotacticity of the resulting polymer (polymer), and the lower the heat resistance of the finally obtained resin composition. Therefore, in order to obtain a resin composition having high heat resistance, it is preferable to polymerize at a low temperature. However, if continuous polymerization is carried out at a low temperature using conventional methods (Patent Documents 1 and 2), it takes a long time to achieve the desired polymerization rate, which is great for realizing a long average residence time. The reaction tank, and thus a large space, is not efficient. In addition, if the average residence time becomes longer than necessary, the amount of oligomers such as dimers and trimers increases, and the heat resistance of the resin composition obtained from the polymer composition may be lowered.

  In addition, the amount of polymerization initiator can be set according to other conditions such as polymerization temperature, desired polymerization rate and average residence time, the lower the polymerization temperature and the shorter the average residence time, the desired In order to achieve the polymerization rate, the amount of the polymerization initiator increases. However, the larger the amount of the polymerization initiator, the more the polymerization termination end (terminal polymer) composed of unstable unsaturated bonds in the polymer composition. Since it remains, the thermal stability of the finally obtained resin composition tends to be low. In addition, even if the polymerization temperature for achieving the desired polymerization rate is too high, many polymerization termination ends (terminal polymers) consisting of unsaturated bonds resulting from the polymerization initiator will be generated in the polymerization composition. The heat stability of the finally obtained resin composition tends to be low.

  In particular, when continuous polymerization is carried out in an adiabatic state, the polymerization temperature rises due to heat generated by polymerization because there is substantially no heat coming in and out of the reaction vessel. Therefore, in continuous polymerization in an adiabatic state, the polymerization rate is determined by the temperature difference between the supply temperature of the raw material mixture supplied to the reaction vessel and the polymerization temperature, and the polymerization rate increases as the temperature difference increases. Therefore, if the supply temperature of the raw material mixture supplied to the reaction vessel is higher than −10 ° C., the polymerization temperature has to be increased in order to obtain a predetermined polymerization rate. The thermal stability and heat resistance of the composition tend to be low.

  According to the present embodiment, the raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 is able to keep the polymerization temperature in the reaction vessel 10 low while achieving a desired polymerization rate. The temperature adjusting means provided in the tank and / or the line is controlled so that the temperature is -50 ° C to -10 ° C, and this makes it possible to produce a polymer composition excellent in thermal stability and heat resistance with high productivity. Can be obtained.

-Volatilization step As described above, the polymer composition (polymerization syrup) extracted from the extraction port 11b of the reaction vessel 10 contains unreacted raw material monomers and polymerization initiators in addition to the produced polymer. obtain. Such a polymer composition does not limit the present embodiment, but it is preferable to separate and recover the raw material monomer through devolatilization or the like.

  Specifically, the polymer composition is transferred to the preheater 21 through the extraction line 15. In the preheater 21, a part or all of the heat amount necessary for volatilization of volatile components mainly composed of unreacted raw material monomers is imparted to the polymer composition. The polymer composition is then transferred to a devolatilizing extruder 23 via a pressure regulating valve (not shown), where volatile components are at least partially removed in the devolatilizing extruder, and the remaining extrudate is It is formed into a pellet and taken out from the take-out line 25. Thereby, the resin composition containing a methacrylic ester polymer is produced in the form of pellets.

  As a method for transferring the polymer composition, the method described in JP-B-4-48802 is suitable. Examples of methods using a devolatilizing extruder include, for example, JP-A-3-49925, JP-B-51-29914, JP-B-52-17555, JP-B-1-53682, JP-A-62. The method described in JP-A-89710 is suitable.

  Further, when devolatilizing and extruding the polymer composition with the above devolatilizing extruder, or after that, if necessary, releasing agents such as higher alcohols and higher fatty acid esters, ultraviolet absorbers, heat Stabilizers, colorants, antistatic agents, and the like can be added to the polymer composition or extrudate and included in the resin composition.

  Volatile components removed by the devolatilizing extruder 23 are mainly composed of unreacted raw material monomers, impurities originally contained in the raw material monomers, additives used as necessary, and volatile by-products generated in the polymerization process. It comprises impurities such as products, oligomers such as dimers and trimers, polymerization initiator decomposition products, and the like. Generally, an increase in the amount of impurities is not preferable because the resulting resin composition is colored. Therefore, the volatile component removed by the devolatilizing extruder 23 (consisting of unreacted raw material monomer as a main component and containing impurities as described above) is passed through a monomer recovery tower (not shown), and the monomer It may be treated by means such as distillation or adsorption in a recovery tower, and impurities may be removed from the volatile components, whereby unreacted raw material monomer can be recovered with high purity, and as a raw material monomer for polymerization It can be suitably reused. For example, in the monomer recovery tower, unreacted raw material monomer is recovered with high purity as a distillate from the top of the monomer recovery tower by continuous distillation, stored in the recovery tank 27, and then transferred to the raw material monomer tank 1. May be recycled, or may be transferred to the raw material monomer tank 1 and recycled without being stored in the recovery tank 27. On the other hand, impurities removed in the monomer recovery tower can be discarded as waste.

  In order to prevent the polymerization reaction from proceeding in the recovery tank 27 or the raw material monomer tank 1, the recovered raw material monomer is added with a polymerization inhibitor in the recovery tank 27 or the raw material monomer tank 1, for example, 2 to 2 relative to the raw material monomer. It is preferable to be present at a rate of 8 ppm by weight. In addition, it is more preferable to set the oxygen concentration in the gas phase part of the recovery tank 27 and the raw material monomer tank 1 to 2 to 8% by volume. Further, when it is desired to store in the recovery tank 27 for a long period, it is desirable to store at a low temperature of, for example, 0 to 5 ° C.

  In this embodiment, the continuous block polymerization apparatus used in order to implement continuous block polymerization was demonstrated. However, the continuous polymerization apparatus used for carrying out the continuous polymerization of the present invention is not limited to this and may be used for carrying out continuous solution polymerization. In such an embodiment, since a solvent is used for solution polymerization, the continuous polymerization apparatus has the same configuration as the continuous polymerization apparatus described above with reference to FIG. And a solvent tank and a supply line and a pump (supply means) associated therewith. These solvent tanks and the supply lines and pumps (supply means) associated therewith are not particularly limited, and those similar to those conventionally used can be used. The solvent is supplied to the reaction vessel after being mixed with the raw material monomer and / or the polymerization initiator so that the temperature of the raw material mixture containing the raw material monomer, the polymerization initiator and the solvent is -50 ° C to -10 ° C. That's fine. Continuous solution polymerization is carried out in the same manner as the polymerization step described above with reference to FIG. 1 except that a solvent is used in the polymerization reaction. The solvent is appropriately set according to the raw material monomer of the solution polymerization reaction and is not particularly limited. For example, toluene, xylene, ethylbenzene, methyl isobutyl ketone, methyl alcohol, ethyl alcohol, Examples include octane, decane, cyclohexane, decalin, butyl acetate, and pentyl acetate. The ratio C: D between the supply flow rate C (kg / h) of the raw material monomer to the reaction tank and the supply flow rate D (kg / h) of the solvent to the predetermined reaction tank is not limited to this. Is, for example, 70:30 to 95: 5, preferably 80:20 to 90:10.

  As mentioned above, the manufacturing method of the polymer composition of this invention was explained in full detail through embodiment of this invention. According to the present invention, the resin composition finally obtained by carrying out continuous polymerization with the temperature of the raw material mixture containing the raw material monomer and the polymerization initiator supplied to the reaction vessel 10 being −50 ° C. to −10 ° C. The syndiotacticity of the polymer contained in the product can be controlled, and a polymer composition suitable for obtaining a resin composition having high heat resistance and thermal stability can be produced more efficiently.

  In addition, this invention is not limited to said embodiment, A various change is possible. For example, using two or more reaction vessels, the polymerization may be carried out in series of two or more. The method for producing the polymer composition of the present invention is preferably carried out continuously using the continuous polymerization apparatus of the present invention, but may be carried out batchwise.

  The polymer composition obtained by the production method of the present invention can be suitably used as a material for a molded product, and the molded product obtained thereby has an advantage of having high heat resistance and thermal stability. For example, the polymer composition (more specifically, the resin composition after devolatilization) obtained by the production method of the present invention is used alone, or together with any appropriate other components such as injection molding, extrusion molding, etc. It can shape | mold by arbitrary shaping | molding methods and can obtain a molded object. The polymer composition obtained by the production method of the present invention is preferably used when a molded body is obtained by injection molding, and the molded body can be obtained with good moldability by suppressing the occurrence of silver streak. In particular, since a resin composition containing a methacrylic acid ester-based polymer has excellent transparency, a molded product obtained by injection molding of the resin composition has high transparency and silver streak is generated. Since it is suppressed and has good moldability, it is preferably used as a light guide plate used as a backlight unit member of various liquid crystal displays, a vehicle member such as a tail lamp cover, a head lamp cover, a visor, and a meter panel. In particular, it is suitably used as a light guide plate.

  The injection molding can be carried out by filling (injecting) a polymer composition obtained by at least the production method of the present invention into a mold having a predetermined thickness in a molten state, and then cooling and then demolding the molded article. . Specifically, for example, a polymer composition (more specifically, a resin composition after devolatilization) obtained by the production method of the present invention is molded from a hopper alone or together with any appropriate other component. The resin composition is put into the machine, moved backward while rotating the screw, the resin composition is weighed in the cylinder of the molding machine, the resin composition is melted in the cylinder, and the mold ( For example, a mold can be manufactured by filling in a mold), holding the pressure for a certain period of time until the mold is sufficiently cooled, and then opening the mold and taking out the molded body.

  Therefore, according to the other summary of this invention, the molded object obtained from the polymer composition obtained by the manufacturing method of this invention is also provided. Various conditions for producing the molded product of the present invention from the polymer composition (for example, in the case of injection molding, the melting temperature of the molding material, the mold temperature when the molding material is injected into the mold, the resin composition as the mold) What is necessary is just to set suitably about the pressure at the time of hold | maintaining after filling, and it does not specifically limit.

  A methacrylic polymer composition suitable for obtaining a high-quality resin composition required for a wide range of applications by the production method of the present invention (for example, excellent physical properties such as heat resistance and thermal stability, and less contamination of impurities) Polymer composition).

DESCRIPTION OF SYMBOLS 1 Raw material monomer tank 3 Polymerization initiator tank 4 Raw material monomer supply line 5 Monomer supply means 6 Polymerization initiator supply line 7 Initiator supply means 9 Raw material supply line 10 Reaction tank 11a Supply port 11b Extraction port 13 Jacket 14 Stirrer 15 Extraction line 21 Preheater 23 Devolatilizing Extruder 25 Takeout Line 27 Collection Tank

Claims (7)

A raw material mixture containing a raw material monomer containing 50% by mass or more of methyl methacrylate and a polymerization initiator is supplied from a supply port of a complete mixing type reaction tank, subjected to continuous polymerization in the reaction tank, and the resulting weight A method for producing a methacrylic polymer composition in which a coalescence composition is extracted from an extraction port of the reaction tank,
The method for producing a methacrylic polymer composition, wherein the temperature of the raw material mixture supplied to the reaction vessel is -50 ° C to -10 ° C.   The method for producing a methacrylic polymer composition according to claim 1, wherein the outlet of the reaction vessel is located at the top of the reaction vessel.   The method for producing a methacrylic polymer composition according to claim 1 or 2, wherein the continuous polymerization is performed in an adiabatic state.   The method for producing a methacrylic polymer composition according to any one of claims 1 to 3, wherein a polymerization temperature in the continuous polymerization is 120 ° C to 150 ° C.   The method for producing a methacrylic polymer composition according to any one of claims 1 to 4, wherein the continuous polymerization is continuous bulk polymerization.   The molded object obtained from the methacrylic-type polymer composition obtained by the manufacturing method in any one of Claims 1-5.   The molded body according to claim 6, wherein the molded body is a light guide plate.

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