Method for producing polymer, device for producing polymer, and system for optimizing radical polymerization reaction

Abstract

Provided are a method for producing a polymer in which the composition or molecular weight of structural units is highly controlled in addition to high purity, and a device for producing a polymer. A method for producing a polymer, which obtains a polymer by radical polymerization in the coexistence of an azo polymerization initiator, two or more types of monomers, and a solvent, the method comprising a first step for radical polymerization in a tubular reactor, and a second step for radical polymerization in the tubular reactor, performing the radical polymerization in a stirred tank reactor after the first step; the maximum solid content concentration (C1max) on a mass basis in the first step is 30 mass% or more, the maximum solid content concentration (C2max) on a mass basis in the second step is less than 50 mass%, and the maximum solid content concentration (C1max) and the maximum solid content concentration (C2max) satisfy C1max > = C2max.

Description

Technical Field

[0001] The present invention relates to a method for producing a polymer, a polymer producing device and an optimization system for a free radical polymerization reaction. Background Art

[0002] The development of high-value-added raw materials for semiconductor and optical applications has been remarkable, and various improvements have been repeatedly made. Similarly, research into reaction processes and reaction components has led to advancements in polymer quality, functionality, and process efficiency (e.g., Japanese Unexamined Patent Publication No. 2012-107163, Japanese Patent No. 3341568, Japanese Patent No. 3113205, Japanese Translation of National Publication No. 2006-511657, Japanese Patent No. 6800700, Japanese Patent No. 6800827, Japanese Patent No. 6121963, Japanese Patent No. 5624155, etc.).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-107163

[0006] Patent Document 2: Japanese Patent No. 3341568

[0007] Patent Document 3: Japanese Patent No. 6800700

[0008] Patent Document 4: Japanese Patent No. 6800827

[0009] Patent Document 5: Japanese Patent No. 6121963

[0010] Patent Document 6: Japanese Patent No. 5624155 Summary of the Invention

[0011] In addition to high purity, polymers are particularly required to have highly controlled structural unit composition (hereinafter referred to as "composition") and molecular weight. If a polymer contains impurities such as metals, or if its composition or molecular weight (hereinafter referred to as "composition") is uneven, these can become defects in the final application, potentially leading to reduced yield or performance. Existing technologies cannot be said to fully meet these requirements.

[0012] The present invention aims to provide a method for producing a polymer having high purity and highly controlled structural unit composition or molecular weight, a polymer production apparatus, and an optimized system for free radical polymerization reaction.

[0013] The present inventors have conducted intensive studies to solve the problems and, as a result, have found that the above-mentioned object can be achieved by adopting the following configuration, thereby completing the present invention.

[0014] That is, the present invention relates in one embodiment to a method for producing a polymer.

[0015] The polymer is obtained by free radical polymerization in the coexistence of an azo polymerization initiator, two or more monomers and a solvent, and the method for producing the polymer comprises:

[0016] In the first step, the free radical polymerization is carried out in a tubular reactor, and

[0017] The second step is to carry out the free radical polymerization in a stirred tank reactor after the first step;

[0018] The maximum solid content concentration C1 in the first step is based on mass. max 30% by mass or more (hereinafter, the maximum solid content concentration C1 max The set concentration range is also referred to as "concentration condition (i)").

[0019] The maximum solid content concentration C2 based on mass in the second step max Less than 50% by mass (hereinafter referred to as the maximum solid content concentration C2 max The set concentration range is also referred to as "concentration condition (ii)").

[0020] The above maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max Satisfy C1 max ≥C2 max (hereinafter, the above-mentioned maximum solid content concentration C1 max With the highest solid content concentration C2 max The relationship is also called "concentration condition (iii)"),

[0021] The temperature T1[°C] in the tubular reactor in the first step and the temperature T2[°C] in the stirred tank reactor in the second step satisfy |T1-T2|<20 (hereinafter, the relationship satisfied by the temperature T1[°C] and the temperature T2[°C] is also referred to as "temperature difference condition (A)").

[0022] Living radical polymerization, widely used to control structural unit composition and molecular weight, has limitations in achieving high purity due to the presence of metal catalysts or sulfur-containing compounds in the reaction system. This production method utilizes an azo polymerization initiator that generates easily removable nitrogen molecules (nitrogen gas) during the radical polymerization of two or more monomers, enabling the production of high-purity polymers.

[0023] The present inventors investigated methods for controlling the composition and other properties of polymers in free-radical polymerization systems using azo-based polymerization initiators, using the copolymerization of methyl methacrylate and styrene as a representative example, a process previously considered difficult to control. They unexpectedly discovered that the difference in polymerization rates between the two monomers decreases in high and low concentration ranges, which are not typical monomer concentration ranges assumed in conventional industrial production processes. This discovery led to the discovery that the composition and molecular weight of a polymer may be controlled to a certain extent as a function of concentration.

[0024] Because productivity is low even when using a batch-type stirred tank reactor for reactions in the low-concentration range, the present inventors investigated the high-concentration range. However, since it became apparent that temperature control during polymerization reactions in the high-concentration range, particularly at the initial stage of the reaction, was difficult in stirred tank reactors, attempts were made to control the polymerization reaction using a tubular reactor (so-called flow reactor) with improved temperature controllability and mixing performance, instead of a stirred tank reactor. However, once the polymerization reaction proceeded to a certain point, thickening due to the product or bubbles generated by nitrogen gas generated by the azo polymerization initiator led to a loss of reaction controllability.

[0025] The present inventors conducted further research and discovered that a combination of a tubular reactor and a stirred tank reactor can solve the problems associated with using either reactor separately. Specifically, the present invention provides a method in which the polymerization reaction is controlled in the high-concentration region, particularly in the initial stages of the reaction, in a tubular reactor with high temperature controllability and mixing performance. Before reaching the stage where thickening or bubbles form, the polymerization reaction is switched to a low-concentration region in a stirred tank reactor, which facilitates the addition and extraction of components and gas removal. This allows the polymerization reaction to be completed while suppressing thickening and bubble formation.

[0026] Based on these findings, the present inventors studied the concentration ranges within each reactor and the temperature control within each step. As a result, they discovered that a large temperature difference between the tubular reactor in the first step and the stirred tank reactor in the second step results in the appearance of two or more peaks in molecular weight distribution measurement. The present invention is based on these novel findings.

[0027] By performing the first step in a tubular reactor with high temperature controllability, the composition and molecular weight of the produced polymer can be highly controlled. By performing the subsequent second step in a stirred tank reactor, poor control caused by thickening or bubble generation can be suppressed, and the series of steps from initiation to completion of free radical polymerization can be seamlessly performed. Furthermore, by ensuring that concentration conditions (i), (ii), and (iii), as well as temperature difference condition (A), fall within specified ranges, the polymerization rate can be controlled based on concentration and temperature in each step, resulting in the efficient production of polymers with highly controlled composition and molecular weight.

[0028] In this specification, the "solid content" refers to monomers and their reactants (including low-polymerization-degree polymers (oligomers) and polymers, and their growing radicals). Therefore, the solid content does not include solvents and azo-based polymerization initiators.

[0029] In one embodiment, it is preferred that the maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max Satisfy C1 max >C2 max According to this manufacturing method, since the reactants after the first step are also controlled to a certain extent, even within the range of satisfying concentration conditions (i) and (ii), the maximum solid content concentration C1 max With the highest solid content concentration C2 max Furthermore, by satisfying the concentration condition (iii) C1 max >C2 max , and the first step is carried out in a relatively high concentration region, while on the other hand, the second step is carried out in a relatively low concentration region, so that the polymerization rate can be optimized in the two steps. As a result, a polymer with a more highly controlled composition can be produced.

[0030] In one embodiment, from the viewpoint of suppressing thickening action or generation of bubbles, the polymerization conversion rate in the first step is preferably 80% or less.

[0031] In one embodiment, the temperature T1 [°C] and the temperature T2 [°C] preferably satisfy |T1-T2| ≤ 10. Furthermore, the temperature T1 [°C] and the temperature T2 [°C] preferably satisfy T1 ≥ T2. By controlling the temperature difference condition (A) as described above, a highly controlled composition and molecular weight distribution corresponding to the desired properties of the polymer can be achieved.

[0032] In one embodiment, the monomers are preferably two or more selected from one or more monomers of (meth)acrylic acid or its ester and one or more aromatic vinyl monomers. Preferably, the monomers are one or more monomers of (meth)acrylic acid or its ester and one or more aromatic vinyl monomers. Although it is considered difficult to control the composition of the resulting polymer in the free radical polymerization of these monomers, this production method allows efficient production of polymers with highly controlled composition.

[0033] In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0034] In one embodiment, the free radical polymerization is preferably carried out in the absence of dormant species. This production method allows for control of the polymerization rate of the monomers in terms of concentration, and thus, even without using living free radical polymerization requiring dormant species, a polymer with high purity and highly controlled composition can be produced with good yield.

[0035] In this specification, the term "dormant species" refers to a chemical species in which an active radical at the growing end of a polymer chain is temporarily and reversibly inactivated (stabilized) into a covalently bonded species.

[0036] In one embodiment, it is preferred that the maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max Satisfy C1 max =C2 max This can suppress changes in monomer concentration during transfer from the tubular reactor of the first step to the stirred tank reactor of the second step, enabling a high degree of control over the composition of the resulting polymer. This is particularly suitable as a concentration condition for scaled-up polymerization reactions, where the influence of changes in monomer concentration can be significant.

[0037] In another embodiment, the present invention relates to a polymer production apparatus, which obtains a polymer by free radical polymerization in the coexistence of an azo polymerization initiator, two or more monomers, and a solvent.

[0038] The polymer production apparatus is provided with a tubular reactor and a stirred tank reactor for respectively carrying out the free radical polymerization.

[0039] The maximum solid content concentration C1 in the tubular reactor on a mass basis max 30% by mass or more,

[0040] The maximum solid content concentration C2 in the stirred tank reactor on a mass basis max Less than 50% by mass

[0041] The above maximum solid content concentration C1max and the above-mentioned maximum solid content concentration C2 max Satisfy C1 max ≥C2 max ,

[0042] The temperature T1 [° C.] in the tubular reactor in the first step and the temperature T2 [° C.] in the stirred tank reactor in the second step satisfy |T1-T2|<20.

[0043] By using this polymer production apparatus, the above-mentioned polymer production method can be efficiently performed, and a polymer having high purity and highly controlled composition can be produced with a high yield.

[0044] In another embodiment, the present invention relates to an optimized system for free radical polymerization, wherein a polymer is obtained by free radical polymerization in a reaction solution comprising a polymerization initiator, a monomer, and a solvent.

[0045] The optimized system for the free radical polymerization reaction has:

[0046] Flow path, for the reaction liquid to flow,

[0047] A feeder supplies one or more of the polymerization initiator, monomer, and solvent to the flow path.

[0048] The tubular reactor and the stirred tank reactor are interposed between the starting end and the terminal end of the flow path in order from the starting end side.

[0049] a detector for obtaining one or more measurement values ​​of at least the reaction solution in the flow path, the tubular reactor, and the stirred tank reactor, and

[0050] a controller connected to the flow path, the feeder, the tubular reactor, and the stirred tank reactor, and configured to control one or more process parameters of each of the flow path, the feeder, the tubular reactor, and the stirred tank reactor;

[0051] The controller has:

[0052] a receiving unit, receiving the measurement value from the detector,

[0053] an estimating unit that estimates the actual progress of the radical polymerization based on the measured value;

[0054] a condition determination unit that compares the actual progress state with the ideal progress state and determines one or more process parameters in each of the flow path, the feeder, the tubular reactor, and the stirred tank reactor within a next unit reaction time so that the actual progress state approximates the ideal progress state; and

[0055] The control unit changes the process parameters of the flow path, the supply device, the tubular reactor, and the stirred tank reactor based on the determined process parameters.

[0056] This free radical polymerization reaction optimization system makes it possible to construct a machine learning system that can efficiently produce high-quality polymers while avoiding excessive trial and error, even when changing the type or amount of polymerization initiators or monomers, or seeking to scale up the polymerization reaction.

[0057] Specifically, the condition determination unit may determine the process parameters by calculating a change in the actual progress state within the next unit reaction time due to a change in the process parameters using a condition setting algorithm.

[0058] In one embodiment, the controller preferably further includes a storage unit that stores the measured values ​​of the process parameters before and after a change, the actual process state, and the difference between the actual process state and the ideal process state. By repeatedly acquiring measured values, estimating the actual process state, determining process parameters, and changing process parameters, a more accurate machine learning optimization system can be constructed.

[0059] The measurement value may be obtained by either inline monitoring or sampling of the reaction solution.

[0060] In one embodiment, the controller may also include an interface for manually controlling the process parameters.

[0061] In one embodiment, from the perspective of correlation with the actual progress state, the measured value preferably includes at least one of the spectrum and viscosity of the reaction solution.

[0062] In one embodiment, the process parameters preferably include at least one of temperature, the amount of monomers added, the amount of azo polymerization initiator added, the amount of solvent added, and stirring speed.

[0063] In one embodiment, the actual progress state preferably includes at least one of the consumption of the monomer and the weight average molecular weight of the polymer. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1A This is a schematic diagram showing an example of a polymer production apparatus.

[0065] Figure 1B It is a schematic diagram showing another example of a polymer production apparatus.

[0066] Figure 2This is a block diagram schematically showing an optimized system for a free radical polymerization reaction.

[0067] Figure 3A This is a graph showing the change in monomer composition ratio over time in the second step of Example 9.

[0068] Figure 3B This is a graph showing the change in monomer composition ratio over time in the second step of Example 10.

[0069] Figure 3C This is a graph showing the change in monomer composition ratio over time in the second step of Example 11.

[0070] Figure 3D This is a graph showing the change in monomer composition ratio over time in the second step of Example 12.

[0071] Figure 3E This is a graph showing the change in monomer composition ratio over time in the second step of Example 13.

[0072] Figure 3F This is a graph showing the change in monomer composition ratio over time in the second step of Example 14.

[0073] Figure 3G This is a graph showing the change in monomer composition ratio over time in the second step of Example 15.

[0074] Figure 3H This is a graph showing the change in monomer composition ratio over time in the second step of Example 16. DETAILED DESCRIPTION

[0075] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

[0076] <Polymer Production Method>

[0077] The method for producing a polymer according to the present embodiment will be described in order with respect to each component used for radical polymerization, a polymer production apparatus, and each step.

[0078] (Azo polymerization initiator)

[0079] As the azo polymerization initiator, a known azo polymerization initiator can be used. Examples of the azo polymerization initiator include 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2-methylbutyronitrile) (AMBN), 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1'-azobis(1-cyclohexanecarbonitrile) (ACHN), dimethyl-2,2'-azobisisobutyrate (MAIB), 4,4'-azobis(4-cyanovaleric acid) (ACVA), 1,1'-azobis(1-acetoxy-1-phenylethane ...ADVN), 1,1'-azobis(1-cyclohexanecarbonitrile) (ACHN), dimethyl-2,2'-azobisisobutyrate (MAIB), Azobis(2-methylaminopropane), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylamidinopropane) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(2,4,4-trimethylpentane), 2-cyano-2-propylazocarbonamide, 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(N-cyclohexyl-2-methylpropionamide). Azo-based polymerization initiators may be used alone or in combination of two or more.

[0080] The 5-minute half-life temperature of the azo polymerization initiator is not particularly limited, but is preferably 40° C. to 120° C. By setting the 5-minute half-life temperature within the above temperature range, handleability is improved, and decomposition in portions outside the heated region (polymerization reaction region) can be suppressed, allowing efficient production of polymers having a highly controlled composition and molecular weight by decomposition in the heated region (polymerization reaction region).

[0081] The 5-minute half-life temperature is the temperature at which the decomposition rate of the azo polymerization initiator reaches 50% within 5 minutes. The 5-minute half-life temperature can be determined based on the 10-hour half-life temperature of the azo polymerization initiator and the activation energy using the reaction rate constant and the Arrhenius equation.

[0082] Examples of azo polymerization initiators having a 5-minute half-life temperature of 60° C. to 120° C. include dimethyl-2,2'-azobisisobutyrate (5-minute half-life temperature: 107° C.), 2,2'-azobis(2,4-dimethylvaleronitrile) (5-minute half-life temperature: 90° C.), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (5-minute half-life temperature: 66° C.), and 2,2'-azobisisobutyronitrile (5-minute half-life temperature: 104° C.).

[0083] The amount of the azo polymerization initiator added may be an amount sufficient to allow free radical polymerization of the monomers to proceed. The lower limit of the amount is preferably 0.5 mol%, more preferably 1 mol%, even more preferably 2 mol%, and particularly preferably 3 mol%, relative to the total amount of the monomers. The upper limit of the amount is preferably 15 mol%, more preferably 10 mol%, even more preferably 8 mol%, and particularly preferably 6 mol%.

[0084] (monomer)

[0085] In this production method, two or more monomers are used as monomers. As monomers, any of the known compounds containing ethylenically unsaturated bonds (carbon-carbon double bonds) or compounds containing acetylenically unsaturated bonds (carbon-carbon triple bonds) that can be used for addition polymerization reactions based on free radical polymerization can be used, but compounds containing ethylenically unsaturated bonds are preferred.

[0086] The ethylenically unsaturated bond-containing compound is preferably two or more selected from one or more monomers of (meth)acrylic acid or its ester (hereinafter also referred to as "monomer (1)") and one or more aromatic vinyl monomers (hereinafter also referred to as "monomer (2)"). As the monomer, two or more monomers (1) may be used, one or more monomers (1) and one or more monomers (2) may be combined, or two or more monomers (2) may be used. The monomers are preferably one or more monomers (1) and one or more monomers (2).

[0087] (Single (1))

[0088] Monomer (1) is a monomer of (meth)acrylic acid or an ester thereof. As the ester of (meth)acrylic acid, a (meth)acrylic acid ester obtained by replacing a hydrogen atom of a carboxyl group of (meth)acrylic acid with a substituent can be preferably used.

[0089] Examples of the (meth)acrylates belonging to the monomer (1) include (meth)acrylates having a chain alkyl group (straight-chain alkyl group or branched alkyl group), (meth)acrylates having a cyclic alkyl group, (meth)acrylates having a polycyclic structure, (meth)acrylates having an aromatic group, (meth)acrylates having a polyalkylene glycol structural unit, (meth)acrylates having a hydroxyl group, (meth)acrylates having a lactone-modified hydroxyl group, (meth)acrylates having an alkoxy group, (meth)acrylates having an oxygen-containing heterocyclic group, (meth)acrylates having an acidic group, and (meth)acrylic acid. These may be used alone or in combination of two or more.

[0090] The (meth)acrylate having a linear alkyl group is preferably a (meth)acrylate having a linear alkyl group with 1 to 20 carbon atoms, more preferably a (meth)acrylate having a linear alkyl group with 1 to 10 carbon atoms, and still more preferably a (meth)acrylate having a linear alkyl group with 1 to 5 carbon atoms. Examples of the (meth)acrylate having a linear alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, decyl (meth)acrylate, n-lauryl (meth)acrylate, and n-stearyl (meth)acrylate.

[0091] The (meth)acrylate having a branched alkyl group is preferably a (meth)acrylate having a branched alkyl group with 3 to 20 carbon atoms, and more preferably a (meth)acrylate having a branched alkyl group with 3 to 10 carbon atoms. Examples of the (meth)acrylate having a branched alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, and isodecyl (meth)acrylate.

[0092] The (meth)acrylate having a cyclic alkyl group is preferably a (meth)acrylate having a cyclic alkyl group with 6 to 12 carbon atoms. Examples of the cyclic alkyl group include cyclic alkyl groups having a monocyclic structure (e.g., a cycloalkyl group). Specific examples of the (meth)acrylate having a monocyclic alkyl group include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate.

[0093] The (meth)acrylate having a polycyclic structure is preferably a polycyclic structure having 6 to 12 carbon atoms. Examples of the polycyclic structure include cyclic alkyl groups having a bridged ring structure (e.g., adamantyl, norbornyl, and isobornyl). Specific examples of the (meth)acrylate having a polycyclic structure include isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate.

[0094] The (meth)acrylate having an aromatic group is preferably an aromatic group having 6 to 12 carbon atoms, and more preferably an aromatic group having 6 to 9 carbon atoms. Examples of the aromatic group include aryl, alkylaryl, aralkyl, aryloxy, aryloxyalkyl, alkylaryloxy, and aralkyloxy groups, with phenyl, benzyl, tolyl, and phenoxyethyl being particularly preferred. Specific examples of the (meth)acrylate having an aromatic group include benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate.

[0095] Examples of the (meth)acrylate having a polyalkylene glycol structural unit include (meth)acrylates having a polyethylene glycol structural unit such as polyethylene glycol (polymerization degree = 2-10) methyl ether (meth)acrylate, polyethylene glycol (polymerization degree = 2-10) ethyl ether (meth)acrylate, polyethylene glycol (polymerization degree = 2-10) propyl ether (meth)acrylate, and polyethylene glycol (polymerization degree = 2-10) phenyl ether (meth)acrylate; and (meth)acrylates having a polypropylene glycol structural unit such as polypropylene glycol (polymerization degree = 2-10) methyl ether (meth)acrylate, polypropylene glycol (polymerization degree = 2-10) ethyl ether (meth)acrylate, polypropylene glycol (polymerization degree = 2-10) propyl ether (meth)acrylate, and polypropylene glycol (polymerization degree = 2-10) phenyl ether (meth)acrylate.

[0096] As the above-mentioned (meth)acrylate having a hydroxyl group, preferably a hydroxyalkyl (meth)acrylate. The carbon number of the hydroxyalkyl group of the hydroxyalkyl (meth)acrylate is preferably 1 to 10, more preferably 1 to 5. The above-mentioned hydroxyalkyl group may be linear or branched, and preferably has one hydroxyl group. Specific examples of the above-mentioned (meth)acrylate having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate.

[0097] As the (meth)acrylate having a lactone-modified hydroxyl group, there can be mentioned substances obtained by adding lactone to the (meth)acrylate having a hydroxyl group, preferably substances to which caprolactone is added. The amount of caprolactone added is preferably 1 to 10 mol, more preferably 1 to 5 mol. As the (meth)acrylate having a lactone-modified hydroxyl group, there are preferably caprolactone 1 mol adduct of 2-hydroxyethyl (meth)acrylate, caprolactone 2 mol adduct of 2-hydroxyethyl (meth)acrylate, caprolactone 3 mol adduct of 2-hydroxyethyl (meth)acrylate, caprolactone 4 mol adduct of 2-hydroxyethyl (meth)acrylate, caprolactone 5 mol adduct of 2-hydroxyethyl (meth)acrylate, caprolactone 10 mol adduct of 2-hydroxyethyl (meth)acrylate, etc.

[0098] Examples of the (meth)acrylate having an alkoxy group include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate.

[0099] As the (meth)acrylate having an oxygen-containing heterocyclic group, a (meth)acrylate having a 4- to 6-membered oxygen-containing heterocyclic group is preferred. Specific examples of the (meth)acrylate having an oxygen-containing heterocyclic group include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, 2-[(2-tetrahydropyranyl)oxy]ethyl (meth)acrylate, 1,3-dioxolan-4-yl]methyl (meth)acrylate, and the like. Alkane-(meth)acrylate, etc.

[0100] Examples of the acidic group include a carboxyl group (—COOH), a sulfonic acid group (—SO₃H), a phosphoric acid group (—OPO₃H₂), a phosphonic acid group (—PO₃H₂), and a phosphinic acid group (—PO₂H₂). Examples of the (meth)acrylate having an acidic group include (meth)acrylates having a carboxyl group, such as monomers obtained by reacting an acid anhydride such as maleic anhydride, succinic anhydride, or phthalic anhydride with a hydroxyalkyl (meth)acrylate; (meth)acrylates having a sulfonic acid group such as ethyl (meth)acrylate sulfonate; and (meth)acrylates having a phosphoric acid group such as 2-(phosphonooxy)ethyl (meth)acrylate.

[0101] (Single (2))

[0102] Monomer (2) is an aromatic vinyl monomer. The aromatic vinyl monomer is not particularly limited as long as it is a compound having a vinyl group or a vinylidene group bonded to an aromatic ring. Examples thereof include styrene monomers such as styrene, vinyltoluene, methoxystyrene, α-methylstyrene, α-hydroxymethylstyrene, and α-hydroxyethylstyrene; polycyclic aromatic hydrocarbon ring vinyl monomers such as 2-vinylnaphthalene; and aromatic heterocyclic vinyl monomers such as N-vinylcarbazole, 2-vinylpyridine, vinylimidazole, and vinylthiophene. Among these, styrene monomers are preferred. Styrene monomers include not only styrene but also styrene derivatives having any substituent bonded to the polymerizable double bond carbon or benzene ring of styrene. Examples of such substituents include alkyl groups, alkoxy groups, hydroxyl groups, halogen groups, amino groups, nitro groups, and sulfonic groups. The alkyl group and alkoxy group bonded to styrene preferably have 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms. At least a portion of the hydrogen atoms of the alkyl group and alkoxy group bonded to styrene may be substituted with a hydroxyl group or a halogen group. The styrene-based monomer is preferably an unsubstituted styrene in which no substituent is bonded to the polymerizable double bond carbon of styrene or the benzene ring.

[0103] The proportion of each monomer can be appropriately set according to the characteristics required by the polymer. The lower limit of the proportion of monomer (1) in the total proportion of monomer (1) and monomer (2) (total when there are multiple) can be, for example, 1 mol%, 2 mol%, 3 mol%, 5 mol%, 8 mol%, 10 mol%, 20 mol%, 30 mol%, 40 mol% or 45 mol%. The upper limit of the proportion of monomer (1) can be 99 mol%, 98 mol%, 97 mol%, 95 mol%, 92 mol%, 90 mol%, 80 mol%, 70 mol%, 60 mol% or 55 mol%. The proportion of monomer (1) and monomer (2) can also be the same (that is, both are 50 mol%).

[0104] (Solvent)

[0105] The solvent is not particularly limited as long as it can dissolve or disperse at least the azo polymerization initiator and the monomer.

[0106] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, halogen solvents, nitrile solvents, and sulfoxide solvents.

[0107] Examples of the alcohol solvent include monoalcohol solvents having 1 to 18 carbon atoms, such as isopropyl alcohol, 4-methyl-2-pentanol, 3-methoxybutanol, n-hexanol, 2-ethylhexanol, furfuryl alcohol, cyclohexanol, 3,3,5-trimethylcyclohexanol, and diacetone alcohol.

[0108] Polyol solvents having 2 to 18 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol;

[0109] Polyol partial ether solvents obtained by etherifying part of the hydroxyl groups of the above-mentioned polyol solvents, and the like.

[0110] Examples of the ether solvent include dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether;

[0111] Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;

[0112] Ether solvents containing aromatic rings such as diphenyl ether and anisole (methyl phenyl ether);

[0113] Polyol ether solvents obtained by etherifying the hydroxyl groups possessed by the above-mentioned polyol solvents, and the like.

[0114] Examples of the ketone solvent include chain ketone solvents such as acetone, butanone, and methyl-isobutyl ketone;

[0115] Cyclic ketone solvents such as cyclopentanone, cyclohexanone, and methylcyclohexanone;

[0116] 2,4-pentanedione, acetonylacetone, acetophenone, etc.

[0117] Examples of the amide solvent include cyclic amide solvents such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone;

[0118] Chain amide solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.

[0119] Examples of the ester solvent include monocarboxylic acid ester solvents such as ethyl acetate, n-butyl acetate, and ethyl lactate;

[0120] Polyol partial ether acetate solvents such as diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether acetate;

[0121] Lactone solvents such as γ-butyrolactone and valerolactone;

[0122] Carbonate solvents such as diethyl carbonate, ethylene carbonate, and propylene carbonate;

[0123] Polycarboxylic acid diester solvents such as propylene glycol diacetate, methoxytriethylene glycol acetate, diethyl oxalate, ethyl acetoacetate, ethyl lactate, and diethyl phthalate.

[0124] Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane;

[0125] Aromatic hydrocarbon solvents such as benzene, toluene, diisopropylbenzene, and n-pentylnaphthalene.

[0126] Examples of the halogen-based solvent include dichloromethane, chloroform, and tetrachloromethane.

[0127] Examples of the nitrile solvent include acetonitrile and propionitrile.

[0128] Examples of the sulfoxide-based solvent include dimethyl sulfoxide and tetrahydrothiophene 1,1-dioxide.

[0129] The mixing ratio of the monomers (total amount) to the solvent may be appropriately set to obtain the maximum solid content concentration described below. The lower limit of the ratio of the mass m1 of the solvent to the total mass m2 of the monomers (m1 / m2) may be 0.5, 1, 1.5, or 2. The upper limit of the above ratio (m1 / m2) may be 10, 9.5, 9, 8.5, or 8.

[0130] (Polymer properties)

[0131] The molecular weight of the obtained polymer is not particularly limited and can be appropriately set according to the required properties. The lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of the polymer measured by gel permeation chromatography (GPC) can be 1000, 2000, 3000, 4000, 5000, 8000 or 10000. The upper limit of the above-mentioned weight average molecular weight can be 100000, 80000, 50000, 30000, 20000 or 15000.

[0132] The ratio (Mw / Mn) of the polymer's Mw measured by GPC to the polystyrene-equivalent number average molecular weight (Mn) is preferably 1 to 2, more preferably 1 to 1.9, further preferably 1 to 1.8, and particularly preferably 1 to 1.6.

[0133] The method for measuring Mw and Mn of the polymer is based on the description in the Examples.

[0134] Polymer production equipment

[0135] Reference Figure 1A and Figure 1B Various embodiments of the polymer production apparatus will be described. Figure 1A This is a schematic diagram showing an example of a polymer production apparatus. Figure 1BSchematic diagram showing another example of a polymer production apparatus. The polymer production apparatus 1, 1B comprises a tubular reactor 10 and a stirred tank reactor 20 in this order, and free radical polymerization of monomers is performed in the tubular reactor 10 and the stirred tank reactor 20 respectively. Figure 1A In the embodiment, a stirred tank reactor 20 is provided. Figure 1B In the embodiment, three stirring tank type reactors 20 (20a, 20b, 20c) are provided.

[0136] (First embodiment)

[0137] Figure 1A The polymer production apparatus 1 shown is equipped upstream of a tubular reactor 10 with: an initiator tank 11 filled with a solution containing an azo polymerization initiator in a solvent; a monomer tank 12 filled with a mixed solution containing a monomer (1) and a monomer (2) in a solvent; a manifold 14 provided at the confluence of flow paths extending from the initiator tank 11 and the monomer tank 12; metering pumps 13a and 13b interposed in the flow paths between the initiator tank 11 and the monomer tank 12 and the manifold 14; and the manifold 14. The tubular reactor 10 is equipped with a coiled flow path 17 extending from the manifold 14 and immersed in an oil bath 16. The polymer production apparatus 1 is further equipped with a pressure gauge 15 connected to the flow path between the manifold 14 and the coiled flow path 17; and a three-way valve 18, one end of which extends from the coiled flow path 17, the other end of which is connected to the stirred tank reactor 20, and the other end of which is connected to an outlet 19. The oil bath 16 has a temperature regulator (not shown) including a thermometer and a heater. The output of the heater is adjusted based on the temperature information from the thermometer.

[0138] Stream is the pipe that is connected till the terminal that polymer is discharged to stirred tank reactor 20 from the starting end of supplying starting raw material solution.As the cross-sectional shape of pipe, circle, ellipse, triangle, quadrilateral, hexagon etc. can be enumerated, preferably circle.The cross-sectional dimension (inner diameter) when the cross section of pipe is circle is as long as considering flow rate or heat conduction efficiency etc. and suitably determines from the scope of more than 0.1mm and less than 100mm.The number of stream can be one, also can be multiple.In addition, also can make multiple streams merge midway, also can branch into multiple midway by a stream.

[0139] exist Figure 1AIn the polymer production apparatus 1 shown, although a monomer tank 12 for storing a mixed solution of monomers (1) and (2) is provided, the mixed solution of monomers (1) and (2) may be stored separately in two or more monomer tanks. Alternatively, the monomers (1) and (2) may be stored in separate monomer tanks. Similarly, the initiator tank 11 may be divided into two or more initiator tanks for storing the initiator. In addition, a solvent tank for storing only the solvent may be provided separately.

[0140] Examples of the metering pumps 13 a , 13 b , and 13 c include syringe pumps, plunger pumps, tube pumps, and diaphragm pumps.

[0141] In the manifold 14, monomers (1) and (2) and an azo polymerization initiator are mixed. The confluence point of the two flow paths is not limited to a single location such as the manifold 14. One or both of the flow paths from the monomer tank and the initiator tank may branch off and merge at two or more locations. In addition, a mixer may be provided at the confluence point.

[0142] Coiled flow path 17 is immersed in oil bath 16. In the immersed area, the contents of the flow path are heated, thereby promoting a free radical polymerization reaction of the monomers. Therefore, the confluence of the flow paths is preferably located just before reaching oil bath 16. A known heater, such as a band heater or mantle heater, can be used in place of oil bath 16. The tubular reactor 10 can be constructed not only with a coiled structure, as exemplified by coiled flow path 17, but also with any other structure, such as a corrugated structure, a structure in which one end of a U-shaped tube is connected to the other end of another U-shaped tube for continuous connection, or a structure in which a main tube branches into multiple thin tubes that converge back into the main tube.

[0143] The length of the immersed region (heated region) of the coiled flow path 17 immersed in the oil bath 16 can be appropriately set within a range of 0.1 m to 100 m depending on the reaction time of radical polymerization, polymerization conversion rate, and the like.

[0144] Although the number of coiled flow paths 17 is usually one, the flow path from the collecting pipe 14 may be branched to provide two or three or more coiled flow paths 17 .

[0145] A temperature regulator may be separately provided in the flow path between the tubular reactor 10 and the stirred tank reactor 20 .

[0146] The stirred tank reactor 20 includes a tank container 21 for receiving the reactant solution from the tube reactor 10 , a stirring blade 22 and a temperature regulator (not shown) disposed in the tank container 21 , and a discharge pipe 23 extending from the tank container 21 to the outside.

[0147] A known reaction container such as a flask or a reactor can be used as the tank container 21 according to the scale. The capacity of the tank container 21 can also be appropriately set within the range of 0.01 L or more and 100 L or less according to the scale.

[0148] The number of openings in the tank-shaped container 21 for receiving the flow from the tubular reactor 10 is not limited to one, and may be two, three, or more. If the tank-shaped container 21 has multiple openings, some of the openings may be used to receive the flow from the tubular reactor 10, while the other openings may be used as inlets for adding a solution of additional monomers or a solution of an azo polymerization initiator. The tank-shaped container 21 is preferably sealed to allow for control of the internal atmosphere.

[0149] The shape and number of the stirring blades 22 are not particularly limited as long as they can sufficiently mix and stir the reaction liquid in the trough container 21. Instead of or in addition to the stirring blades 22, a stirrer, a baffle, or a water jet may be provided.

[0150] After the polymerization reaction in the stirring tank reactor 20 is completed, the obtained polymer is discharged to the outside through the discharge pipe 23 .

[0151] The number of stirred tank reactors 20 can be as follows: Figure 1A In the case of arranging a plurality of stirred tank reactors 20, the flow path from the coiled flow path 17 can be branched to distribute the reactants to each stirred tank reactor 20, or adjacent stirred tank reactors 20 can be connected by the discharge pipe 23 to form a continuous stirred tank reactor 20. Figure 1B This will be described later.

[0152] The material of each tank, flow path, or reactor is not particularly limited as long as it has excellent durability, corrosion resistance, and thermal conductivity, and typical examples include stainless steel, silicone resin, and fluororesin.

[0153] (First process)

[0154] In the first step, the above-mentioned free radical polymerization is carried out in the tubular reactor 10. The solution of the azo polymerization initiator discharged from the initiator tank 11 and the mixed solution of the monomers (1) and (2) discharged from the monomer tank 12 are mixed by the manifold 14, and the free radical polymerization of the mixed solution is carried out in the immersion area (heating area) of the oil bath 16 in the coiled flow path 17. Generally speaking, since the length of the coiled flow path 17 is sufficiently large relative to the inner diameter of the coiled flow path 17 and the heat exchange between the inside and outside of the coiled flow path 17 is carried out rapidly, the temperature in the tubular reactor 10 (coiled flow path 17) can be considered to be substantially the same as the temperature of the oil bath 16. The temperature in the tubular reactor 10 (heating area) can be considered from the perspective of the start and progress of the free radical polymerization reaction. The lower limit of the temperature in the tubular reactor 10 (heating area) is preferably 50°C, more preferably 55°C, and even more preferably 60°C. The upper limit of the above-mentioned temperature is preferably 120°C, more preferably 100°C, and even more preferably 80°C.

[0155] The reaction time (residence time) of the radical polymerization reaction in the immersion area (heating area) of the coiled flow path 17 or the flow rate of the mixture can be appropriately set in consideration of the suppression of thickening or bubble generation in the first step or the polymerization conversion rate. It should be noted that if the reaction time is extremely long or the flow rate is extremely slow, there will be problems in productivity. If the residence time is extremely short or the flow rate is extremely fast, there is a concern that the reaction liquid will not reach the specified temperature and pass through. It should be noted that the flow rate of the azo polymerization initiator solution sent out from the initiator tank 11 and the flow rate of the mixed solution of monomers (1) and (2) sent out from the monomer tank 12 can be appropriately set so as to obtain the mixing ratio of monomers (1) and (2) and the azo polymerization initiator or the desired reaction time.

[0156] The maximum solid content concentration C1 in the first step is based on mass. max It only needs to be 20% by mass or more. Maximum solid content concentration C1 max The lower limit of the maximum solid content concentration C1 is preferably 25% by mass, more preferably 30% by mass, further preferably 40% by mass, and particularly preferably 50% by mass. max The upper limit of the maximum solid content concentration C1 is preferably 95% by mass, more preferably 90% by mass, further preferably 85% by mass, and particularly preferably 80% by mass. max Typically, it is the solid content concentration at the starting point (gas-liquid interface) of the immersion region (heating region) where the coiled flow path 17 is immersed in the oil bath 16. Figure 1A When monomer or azo polymerization initiator is additionally supplied to a portion other than the initiator tank 11 and the monomer tank 12 shown, the high solid content concentration C1 maxIt can also be different from the solid content concentration at the starting point of the above-mentioned heating area. If a person skilled in the art can appropriately determine the maximum solid content concentration C1 max (and the site where it is provided).

[0157] The upper limit of the polymerization conversion rate after the first step is preferably 80%, more preferably 75%, further preferably 70%, and particularly preferably 65%. The lower limit of the polymerization conversion rate in the first step is preferably 30%, more preferably 35%, further preferably 40% or less, and particularly preferably 45%.

[0158] In order to evaluate the polymer obtained in the first step or the reaction liquid containing the polymer, the reaction liquid may be extracted from the discharge port 19 extending from the three-way valve 18 .

[0159] (Second process)

[0160] In the second step, the radical polymerization is carried out in the stirred tank reactor 20 after the first step. By carrying out the second step, which is a aging reaction (subsequent reaction), the radical polymerization reaction can be fully carried out. Therefore, while the polymerization conversion rate after the second step is preferably 100%, the upper limit of the polymerization conversion rate may be 99.5%, 99%, or even 98%.

[0161] Stirring speed can be suitably set according to the concentration of reaction solution or the progress of polymerization reaction etc. For example, when stirring member is a stirring blade, as the lower limit of stirring speed, it is preferably 50rpm, more preferably 100rpm, further preferably 200rpm. As the upper limit of stirring speed, it is preferably 1000rpm, more preferably 800rpm, further preferably 500rpm.

[0162] The lower limit of the temperature in the stirred tank reactor 20 is preferably 50° C., more preferably 55° C., and even more preferably 60° C. The upper limit of the temperature is preferably 100° C., more preferably 80° C., and even more preferably 70° C. The temperature in the stirred tank reactor 20 is preferably set so as to satisfy the temperature difference from the temperature in the tubular reactor 10 in the first step described below.

[0163] The reaction time in the stirred tank reactor 20 can be appropriately set in consideration of the polymerization conversion rate, etc. The lower limit of the reaction time can be 10 minutes, 20 minutes, 30 minutes, 40 minutes, or 50 minutes. The upper limit of the reaction time can be 300 minutes, 250 minutes, 200 minutes, 180 minutes, 150 minutes, or 120 minutes.

[0164] The maximum solid content concentration C2 based on mass in the second stepmax Less than 80% by mass Maximum solid content concentration C2 max The upper limit of the maximum solid content concentration C1 is preferably 60% by mass, more preferably 50% by mass, further preferably 40% by mass, and particularly preferably 30% by mass. max The lower limit of the maximum solid content concentration C2 is preferably 5% by mass, more preferably 10% by mass, further preferably 15% by mass, and particularly preferably 20% by mass. max Typically, it is the solid content concentration when the mixture is fed into the stirred tank reactor 20. When monomers or azo polymerization initiators are additionally supplied to the stirred tank reactor 20 or when the solvent is removed, the maximum solid content concentration C2 max It can also be different from the solid content concentration at the time of the above-mentioned input. If a person skilled in the art can appropriately determine the maximum solid content concentration C2 max (and the timing of providing it).

[0165] In order to evaluate the progress of the polymerization reaction in the second step, the reaction liquid may be extracted from the outlet 23 at an appropriate stage after the start of the reaction.

[0166] (Relationship between the first and second steps)

[0167] The temperature T1 [°C] within the tubular reactor in the first step and the temperature T2 [°C] within the stirred tank reactor in the second step satisfy |T1-T2| < 20. This allows for the production of a polymer having a single peak in molecular weight distribution measurement. The temperatures T1 [°C] and T2 [°C] preferably satisfy |T1-T2| ≤ 10, and more preferably satisfy T1 ≥ T2. This allows for a high level of control over the structural unit composition and target molecular weight.

[0168] The above maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max is set to satisfy C1 max ≥C2 max The above maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max Preferably satisfy C1 max >C2 max , more preferably satisfying C1 max >C2 max +10% by mass, preferably meeting C1 max >C2 max +15% by mass, particularly preferably meeting C1 max >C2 max +20 mass%.

[0169] The above maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max It is also preferred to satisfy C1 max =C2 max Even in the case of a reaction or scale-up where the concentration change of the monomers during the transfer from the tubular reactor 10 of the first step to the stirred tank reactor 20 of the second step affects the reaction, the target polymer can be produced by satisfying the concentration condition (iii). max =C2 max Typically, the reaction liquid discharged from the tubular reactor 10 of the first step can be directly fed into the stirred tank reactor 20 of the second step. Therefore, in this case, it is preferred that no components including a monomer solution or a solvent are present in the stirred tank reactor 20 before the reaction liquid from the first step is fed.

[0170] In any one of the first process and the second process, it is preferred that the above-mentioned radical polymerization is carried out under the condition of the absence of dormant species. As the polymerization reaction via dormant species, polymerization based on nitrogen oxides (NMP)), atom transfer radical addition reaction (ATRA) or atom transfer radical polymerization (ATRP) under the coexistence of a haloalkyl group and a transition metal catalyst, and reversible chain transfer agent (RAFT) polymerization using a thiocarbonyl compound can be enumerated. In the manufacturing method of the polymer of the present embodiment, it is possible to manufacture a polymer having a highly controlled composition, etc. without adopting these polymerization methods.

[0171] (Post-processing)

[0172] As a post-processing after the second step, for example, the obtained polymer solution can be diluted to an appropriate solution viscosity using a good solvent as needed, and then added dropwise to a large amount of poor solvents (methanol, water, hexane, heptane, etc.) to precipitate the polymer. The above-mentioned step (generally referred to as reprecipitation) is effective for removing unreacted monomers, polymerization initiators, etc. remaining in the polymer solution. If the above-mentioned unreacted substances remain, it is possible to adversely affect the performance of the polymer or the final use of the polymer, and therefore it is preferably removed as much as possible. Sometimes, the reprecipitation step is not required depending on the circumstances.

[0173] Thereafter, the precipitate is separated by filtration and fully dried to obtain a polymer. Alternatively, the wet powder may be used directly without drying after separation by filtration.

[0174] (Second embodiment)

[0175] As mentioned above, Figure 1BThe polymer production apparatus 1B of the illustrated embodiment includes three stirred tank reactors 20 (20a, 20b, 20c). It should be noted that while the figure shows three stirred tank reactors 20a, 20b, and 20c, the number of stirred tank reactors 20 is not limited to three and may be two or four or more. The configuration of the devices located upstream of the tubular reactor 10, the configuration of the tubular reactor 10, the configuration of the stirred tank reactors 20 (20a, 20b, 20c), and their operation and conditions are as described in the first embodiment. The following mainly describes the differences from the first embodiment.

[0176] In the flow path through which the reaction liquid from the tubular reactor 10 flows, three-way valves V are provided so as to correspond to the stirred tank reactor 20a, the stirred tank reactor 20b, and the stirred tank reactor 20c, respectively. 2a 、V 2b 、V 2c According to the three-way valve V 2a 、V 2b 、V 2c The reaction liquid is fed into the stirred tank reactors 20a, 0b, and 20c independently by opening and closing the three-way valves. 2c The front end of the flow path (in the figure, from the three-way valve V 2c Arrow extending to the right), can be connected to a further three-way valve and a stirred tank reactor, can also be connected to a recovery tank of the reaction liquid, can also be provided with no components (three-way valve V 2c can be a terminal).

[0177] The polymer production apparatus 1B includes a monomer tank 50 filled with a mixed solution containing monomers so that monomers can be added independently in the second step. A metering pump 51 is provided in the flow path extending from the monomer tank 50. Furthermore, a three-way valve V is provided in the flow path extending from the metering pump 51 so as to correspond to the stirred tank reactors 20a, 20b, and 20c, respectively. 3a 、V 3b 、V 3c According to the three-way valve V 3a 、V 3b 、V 3c The monomer mixture solution is fed into the stirred tank reactors 20a, 20b, and 20c independently by opening and closing the three-way valves. The number of monomer tanks 50 is not limited to one, and two or more monomer tanks may be provided depending on the type of monomer. 3c The front end of the flow path (in the figure, from the three-way valve V 3c Arrow extending to the right), can be connected to the monomer solution recovery tank, can also be provided with no components (three-way valve V 3ccan be a terminal).

[0178] The polymer production apparatus 1B includes a solvent tank 60 filled with a solvent so that the solvent can be added independently in the second step. A metering pump 61 is provided in the flow path extending from the solvent tank 60. Furthermore, a three-way valve V is provided in the flow path extending from the metering pump 61 so as to correspond to the stirred tank reactors 20a, 20b, and 20c, respectively. 4a 、V 4b 、V 4c According to the three-way valve V 4a 、V 4b 、V 4c The solvents are fed into the stirred tank reactors 20a, 20b, and 20c independently by opening and closing the three-way valves. The number of solvent tanks 60 is not limited to one, and two or more solvent tanks may be provided depending on the type of solvent. 4c The front end of the flow path (in the figure, from the three-way valve V 4c The arrow extending to the right) can be connected to the solvent recovery tank, or no component (three-way valve V 4c can be a terminal).

[0179] Figure 1B The polymer production apparatus 1B shown includes the monomer tank 50 and the solvent tank 60 , but may include an initiator tank filled with a solution containing an azo polymerization initiator in a solvent instead of or in addition to the monomer tank 50 and the solvent tank 60 .

[0180] exist Figure 1B In the polymer production apparatus 1B shown in FIG. 1 , three-way valves V are provided corresponding to the tubular reactor 10, the monomer tank 50, and the solvent tank 60. 2a ~V 2c , three-way valve V 3a ~V 3c and three-way valve V 4a ~V 4c , and control each three-way valve. The valve form is not limited to this, and a four-way double switch valve can also be used. For example, it can also replace the three-way valve V 2a ~V 2c Instead, three double on-off valves are provided, and the flow path from the quantitative pump 61 connected to the solvent tank 60 is directly connected to each double on-off valve (in this case, valve V is not required). 4a ~V 4c). The double on-off valve has two switching modes. That is, in the first switching mode, the flow path for circulating the solvent from the metering pump 61 to the stirred tank reactor 20a and the flow path for circulating the reaction liquid from the three-way valve 18 to the recovery tank (not shown) are switched. In the second switching mode, the flow path for circulating the solvent from the metering pump 61 to the recovery tank (not shown) and the flow path for circulating the reaction liquid from the three-way valve 18 to the stirred tank reactor 20a are switched. It is sufficient to appropriately adopt the double on-off valve in consideration of the construction or control of the target reaction system.

[0181] By individually controlling the flow rate of the reaction liquid from the tubular reactor 10 and the three-way valve V 2a 、V 2b 、V 2c The opening and closing timing, the flow rate from the solvent tank 60 and the three-way valve V 4a 、V 4b 、V 4c By controlling the opening and closing timing, it is possible to effectively meet the above-mentioned maximum solid content concentration C1 max and the above-mentioned maximum solid content concentration C2 max C1 max >C2 max The relationship or C1 max =C2 max The control of the flow rate or opening and closing timing can be performed manually, automatically according to a pre-set program, or according to process parameters obtained by the optimization system described later.

[0182] Optimized system for free radical polymerization

[0183] Reference Figure 1A 、 Figure 1B and Figure 2 The optimization system of the radical polymerization reaction according to this embodiment will be described. Figure 2 This is a block diagram schematically showing a radical polymerization reaction optimization system. This optimization system can optimize a radical polymerization reaction in which a polymer is obtained by radical polymerization in a reaction solution containing a polymerization initiator, a monomer, and a solvent.

[0184] The optimization system 100 comprises: a flow path for the reaction solution to flow; a feeder ( Figure 1A and Figure 1B In the embodiment, the initiator tank 11 and the monomer tank 12 are equivalent; hereinafter, in this specification, they are sometimes referred to as "supplies 11, 12"), which supply one or more of the polymerization initiator, monomer and solvent to the above-mentioned flow path; the tubular reactor 10 and the stirred tank reactor 20 are sequentially arranged between the starting end and the terminal end of the flow path from the starting end side; the detectors 30a, 30b, 30c (refer to Figure 2 ;exist Figure 1A and Figure 1B not shown in the figure; hereinafter sometimes collectively referred to as "detectors 30a~30c"), which obtain one or more measurement values ​​of at least the reaction liquid in the flow path, tubular reactor 10 and stirred tank reactor 20; and a controller 40, which is connected to the flow path, feeders 11, 12, tubular reactor 10 and stirred tank reactor 20, and controls one or more process parameters of the flow path, feeders 11, 12, tubular reactor 10 and stirred tank reactor 20.

[0185] The controller 40 includes a receiving unit 41 for receiving measurement values ​​from the detectors 30a to 30c; an estimating unit 42 for estimating the actual progress state of the radical polymerization based on the measurement values; a condition determining unit 43 for comparing the actual progress state with the ideal progress state and determining one or more process parameters within each of the flow path, the feeders 11 and 12, the tubular reactor 10, and the stirred tank reactor 20 for the next unit reaction time so that the actual progress state approximates the ideal progress state; and a control unit 44 for changing the process parameters of the flow path, the feeders 11 and 12, the tubular reactor 10, and the stirred tank reactor 20 based on the determined process parameters. Furthermore, the controller 40 preferably includes a storage unit 45 for storing the measurement values, the actual progress state, and the difference between the actual progress state and the ideal progress state before and after the process parameter change. The controller 40, receiving unit 41, estimation unit 42, condition determination unit 43, control unit 44 and storage unit 45 are implemented by any combination of hardware and software centered around the CPU of any computer, memory, a computer program that implements the constituent elements of this embodiment loaded into the memory, a storage medium such as a hard disk that stores the above program, and an interface for network connection.

[0186] The flow path, the feeders 11 and 12 , the tubular reactor 10 , and the stirred tank reactor 20 of the polymer production apparatus 1 have been described in detail with reference to FIG. 1 .

[0187] Detectors 30a to 30c measure the reaction liquid in the flow path, tubular reactor 10, and stirred tank reactor 20, respectively, and obtain measurement values. In detectors 30a to 30c, the measurement values ​​can be obtained by online monitoring, or by sampling the above-mentioned reaction liquid, or by combining the two to obtain the measurement values. Detectors 30a to 30c are not particularly limited, and examples thereof include infrared spectrometers (IR), near-infrared spectrometers (NIR), Raman spectrophotometers, ultraviolet-visible spectrophotometers, polarimeters, circular dichroism dispersion meters, spectrofluorometers, light scattering photometers, nuclear magnetic resonance (NMR) devices, high-performance liquid chromatography (HPLC) devices, mass spectrometers, optical oxygen concentration meters, particle size distribution meters, viscometers, dynamic viscometers, densitometers, potentiometric analysis devices, current titration devices, electrical quantity analysis devices, conductivity analysis devices, polarographic analysis devices, electrolytic analysis devices, corona charged particle detectors, cameras, high-speed cameras, and the like.

[0188] The above-mentioned measured values ​​preferably include at least one of the spectrum and viscosity of the reaction solution. These measured values ​​correlate well with the (actual) progress of free radical polymerization (particularly, monomer consumption or polymer weight-average molecular weight), enabling high-precision monitoring of the reaction solution's state. Detectors 30a-30c can be selected from any measuring instrument capable of obtaining these measured values.

[0189] After receiving the measured values ​​from the detectors 30a to 30c, the estimating unit 42 estimates the actual progress of the radical polymerization based on the measured values. As described above, the actual progress preferably includes at least one of the monomer consumption and the weight-average molecular weight of the polymer.

[0190] The above-mentioned actual progress status can preferably be estimated by pre-building a regression model obtained by training a data set using training measurement values ​​as independent variables and the actual progress status as dependent variables, and applying the measurement values ​​obtained by detectors 30a~30c to the regression model.

[0191] Monomer consumption can be estimated using, for example, a linear regression model trained using a dataset of monomer concentrations measured by HPLC and spectra measured by IR. The monomer consumption can be estimated by applying the measured values ​​from the start and end points of the tubular reactor 10 and from a detector (infrared spectrophotometer) installed in the stirred tank reactor 20 to the thus constructed linear regression model and calculating the difference between them.

[0192] The weight-average molecular weight of the polymer can be estimated using, for example, a linear regression model or nonlinear regression model trained using a dataset of the composition and concentration of the produced polymer calculated from the weight-average molecular weight of the polymer in terms of polystyrene measured by gel permeation chromatography (GPC), the viscosity of the reaction solution measured by a viscometer, and estimated values ​​of monomer consumption. By applying the measured values ​​from the endpoint of the tubular reactor 10 and the detector (viscometer) installed in the stirred tank reactor 20, and the estimated values ​​of monomer consumption, respectively, to the thus constructed regression model, the weight-average molecular weight of the polymer can be estimated.

[0193] Other measured values ​​indicating the actual progress status can also be estimated by constructing a regression model in the same manner as described above and applying the acquired measured values ​​thereto.

[0194] The constructed regression model and training data set may be stored in the storage unit 45 or in other hardware.

[0195] In the condition determination unit 43 , the ideal progress state used as a comparison target with the actual progress state can be appropriately set according to the states of the target monomer and polymer (monomer consumption or polymer composition, molecular weight, etc.).

[0196] In the condition determination unit 43, although the method for making the above-mentioned actual state approximate to the above-mentioned ideal state is not particularly limited, it is preferred to use a condition setting algorithm to calculate the change of the above-mentioned actual state within the above-mentioned next unit reaction time caused by the change of the above-mentioned process parameters to determine the process parameters. As the above-mentioned condition setting algorithm, for example, experimental planning method, Latin hypercube sampling, Bayesian optimization, linear regression, nonlinear regression (Gaussian process regression, kernel method, neural network, regression tree, etc.) can be cited. Among them, the condition setting algorithm is preferably Bayesian optimization. The condition setting algorithm can also use a well-known algorithm. BoTorch, which is a Python library, can be preferably used in Bayesian optimization.

[0197] When the actual state is the consumption of monomers and the average molecular weight of the polymer, the estimated values ​​of the consumption of monomers and the average molecular weight of the polymer, as well as the process parameters providing the estimated values, are applied to Bayesian optimization to calculate the changes in the above-mentioned actual state within the next unit reaction time to determine the process parameters. Specifically, a randomly selected initial point (initial process parameter) is generated, and a polymerization reaction is carried out in the polymer manufacturing device 1. Therefore, the results (measured values) are obtained from the detectors 30a to 30c. Based on these results, a prediction model is made by Gaussian process regression, and a score that takes into account the balance between utilization and exploration is calculated, and a candidate point (process parameter) within the next unit reaction time is proposed. The polymerization reaction based on the candidate point is carried out again to obtain the result. These results are added to the prediction model made above and the prediction model is updated. By repeating the above steps to update and learn the prediction model, the calculation of the process parameters can be optimized. When randomly selecting the initial point, it is preferably not to select similar points (similar conditions). For the effective random selection of the initial point, a well-known program such as the above-mentioned Latin hypercube sampling can be used.

[0198] The process parameters preferably include at least one of temperature, monomer input, azo polymerization initiator input, solvent input, and stirring speed. Since the calculations in the condition setting algorithm become more complex with the number of process parameters, the number of process parameters is preferably one, two, or three, more preferably one or two. More preferably, the process parameters are temperature, monomer input, and azo polymerization initiator input.

[0199] The control unit 44 changes the process parameters of the flow path, the feeders 11 and 12 , the tubular reactor 10 , and the stirred tank reactor 20 based on the process parameters determined by the condition determination unit 43 .

[0200] The above steps are repeated until the difference between the actual process state and the ideal process state falls within the allowable range. By storing the measured values ​​of the process parameters before and after the change, the actual process state, and the difference between the actual process state and the ideal process state in the storage unit 45 during this repetitive process, a more efficient and high-precision machine learning optimization system can be constructed.

[0201] The operation of the controller 40 may be automated by a predetermined program, or may be performed via an interface (not shown) that enables manual control of the above-mentioned process parameters.

[0202] Example

[0203] Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following Examples.

[0204] [Example 1] Synthesis of polymer (A-1)

[0205] A polymer was produced using a polymer production apparatus 1 having the configuration shown in FIG1 . A total of 100 parts by mass of styrene (ST) as monomer M1 and methyl methacrylate (MMA) as monomer M2 (at a molar ratio of 50 / 50) was dissolved in 200 parts by mass of 1-methoxy-2-propanol (PGME) to prepare a monomer solution, which was then stored in a monomer tank 12. Similarly, a polymerization initiator solution was prepared by dissolving 12.2 parts by mass (5 mol % relative to the total monomer amount) of V-65 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as an azo polymerization initiator in 200 parts by mass of PGME, which was then stored in an initiator tank 11.

[0206] In the tubular reactor 10, a PFA coiled tube (flow path) 17 (the immersion area in the oil bath 16 is 10m long and 1mm in inner diameter) is immersed in an oil bath as a reaction zone. While the temperature of the oil bath 16 is adjusted to 60°C and kept warm, different metering pumps 13a and 13b are used to continuously transport the monomer solution and the polymerization initiator solution at flow rates of 1.57mL / min and 1.57mL / min, respectively, to carry out a free radical polymerization reaction in the coiled tube. The solid content concentration at the starting point (gas-liquid interface of the oil bath) where the coiled tube (flow path) 17 enters the reaction zone is 20% by mass. In the coiled tube, the valve opening on the outlet side is adjusted so that the pressure gauge 15 on the sample introduction side shows 0.0MPa, thereby adjusting to a constant pressure. The flow rate in the coiled tube 17 is 3.14mL / min, and the residence time (i.e., reaction time) in the coiled tube immersed in the oil bath 16 is 10 minutes. The polymerization conversion rate after passing through the immersion zone is 35%.

[0207] Next, the obtained reaction solution 377mL is continuously put into the three-necked flask (stirring tank reactor) 20 with a capacity of 600mL with a thermometer in which a magnetic stirrer as a stirring member is placed inside and the atmosphere is replaced with nitrogen. While adjusting the temperature so that the liquid temperature in the flask reaches 60 ° C with a stirring speed of 400rpm, the polymerization reaction of 230 minutes is carried out as the reaction start time point by the completion time of the input of the reaction solution. The polymerization conversion rate after the completion of the reaction is 80%, and the solid content concentration is 20% by mass. Finally, the obtained polymer (A-1) solution is discharged from the discharge pipe 23.

[0208] [Examples 2 to 8 and Comparative Examples 1 to 6] Synthesis of Polymers (A-2) to (A-8) and Polymers (B-1) to (B-4)

[0209] Polymers (A-2) to (A-8) and polymers (B-1) to (B-4) were obtained in the same manner as in Example 1 except that the operations and conditions in the first and second steps were changed to those shown in Table 1. In Table 1, "-" indicates that the corresponding operation or evaluation was not performed. In Examples 7 and 8, PGME as a solvent was added to the flask in the second step in an amount such that the monomer concentration reached the value shown in Table 2. In Example 8, after the first step was carried out at a molar concentration ratio of monomers of 49:51, styrene as a monomer and 1-methoxy-2-propanol as a solvent were added in the second step to adjust the molar concentration ratio of the monomers to 50:50 (*1). In Comparative Example 3, in the second step, the temperature in the flask was increased from 30°C to 60°C at a heating rate of 1°C / min, and then the reaction was further carried out for 210 minutes, so that the total polymerization time was 240 minutes (*2). In Comparative Example 4, instead of not performing the first step, the raw materials were added dropwise to the reactor over 180 minutes, and the reaction was further carried out for 180 minutes after the completion of the dropwise addition, so that the total polymerization time was 360 minutes (*3).

[0210] <Evaluation>

[0211] The ratio of monomer consumption rates between the reaction stage and the reaction completion stage, as well as the ratio of weight average molecular weights at the completion of the first step and the completion of the second step, were determined for Examples 1 to 8 and Comparative Examples 1 to 6. Furthermore, the following evaluations were performed on the resulting polymers (A-1) to (A-8) and polymers (B-1) to (B-4). The results are shown in Table 1 below.

[0212] [Monomer consumption rate ratio (M1 conversion rate / M2 conversion rate)]

[0213] Measurements were performed using a Shimadzu Corporation reverse-phase column (C-18) at a flow rate of 1.0 mL / min, an elution solvent volume ratio of acetonitrile / ultrapure water = 55 / 45, a sample concentration of 0.2 mass %, a sample injection volume of 1 μL, a column temperature of 40°C, and a detector using an ultraviolet-visible spectrophotometer at a wavelength of 210 nm, using the concentrations of each monomer as a calibration curve. It is believed that when the ratio of the conversion rate of monomer M1 to the conversion rate of monomer M2 (M1 conversion rate / M2 conversion rate) is 0.9 or higher and 1.1 or lower, the monomer consumption rate (conversion rate) is equal, and the structural units derived from each monomer are incorporated into the polymer with greater uniformity.

[0214] [Weight average molecular weight (Mw) at the end of the first step and the end of the second step and the ratio of each weight average molecular weight]

[0215] Measurements were performed by gel permeation chromatography (GPC) using Tosoh Corporation's GPC columns (G2000HXL: 2, G3000HXL: 1, G4000HXL: 1), under the following analytical conditions: flow rate: 1.0 mL / min, elution solvent: THF, sample concentration: 1.0 mass%, sample injection volume: 100 μL, column temperature: 40°C, detector: differential refractometer, using monodisperse polystyrene as a standard. It is believed that if the ratio (Mw1 / Mw2) of the weight-average molecular weight Mw1 at the end of the first step to the weight-average molecular weight Mw2 at the end of the second step is 0.8 or more and 1.1 or less, the weight-average molecular weight of the resulting polymer will be close to the target value, and molecular weight controllability will be high.

[0216] [Residual metal amount]

[0217] The sample was diluted 50-fold with N-methyl-2-pyrrolidone containing 2% by mass nitric acid, and then analyzed using an inductively coupled plasma mass spectrometer (7900, manufactured by Agilent Technology) using an organic solvent torch and a 0.5-second integration time. The analysis conditions were: Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Sn, Ti, Pb, Sb, Co, Ag, Cd, Ba, V, As, and Au. If the total amount of the analyzed elements is less than 10 ppb, it is considered that the metal impurities are low.

[0218] [Residual sulfur content]

[0219] 10 μL of the sample solution was heated to 70°C, depressurized to 5 hPa, and dried. The sample solution was then measured using a fluorescent X-ray analyzer (Rigaku NANOHUNTER II) under the following analytical conditions: tube voltage 50 kV, tube current 12 mA, incident angle 0.030 degrees, focusing angle 0.05 degrees, and measurement time 300 seconds. An analysis value of less than 1 ppm indicates a low level of sulfur impurities.

[0220] [Table 1]

[0221]

[0222] [Example 9] Synthesis of polymer (A-9)

[0223] A polymer was produced using a polymer production apparatus 1 having the configuration shown in FIG1 . A total of 100 parts by mass of cyclohexyl methacrylate (CHMA) as monomer M1 and methyl methacrylate (MMA) as monomer M2 (the molar ratio of M1 / M2 being 0.83) were mixed to prepare a monomer mixed solution, which was then stored in a monomer tank 12. Similarly, 2.8 parts by mass (1.5 mol % relative to the total monomer amount) of V-65 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as an azo polymerization initiator was dissolved in 100 parts by mass of PGME to prepare a polymerization initiator solution, which was then stored in an initiator tank 11.

[0224] In the tubular reactor 10, a PFA coiled tube (flow path) 17 (the immersion area in the oil bath 16 is 10m long and 1mm in inner diameter) is immersed in an oil bath as a reaction zone. While the temperature of the oil bath 16 is adjusted to 90°C and kept warm, different metering pumps 13a and 13b are used to continuously transport the monomer mixture and the polymerization initiator solution at flow rates of 6.1mL / min and 6.5mL / min, respectively, to carry out a free radical polymerization reaction in the coiled tube. The solid content concentration at the starting point (gas-liquid interface of the oil bath) where the coiled tube (flow path) 17 enters the reaction zone is 50% by mass. In the coiled tube, the valve opening on the outlet side is adjusted so that the pressure gauge 15 on the sample introduction side shows 0.0MPa, thereby adjusting to a constant pressure. The flow rate in the coiled tube 17 is 12.6mL / min, and the residence time (i.e., reaction time) in the coiled tube immersed in the oil bath 16 is 2.5 minutes. The polymerization conversion rate after passing through the immersion zone is 36%.

[0225] A magnetic stirrer as a stirring member is placed inside and a three-necked flask (stirring tank reactor) 20 with a capacity of 3000mL with a thermometer in which the atmosphere is replaced with nitrogen is added 1500mL of propylene glycol monomethyl ether as a solvent. 970mL of the reaction solution obtained by the tubular reactor 10 is continuously added thereto. While adjusting the temperature at a stirring speed of 600rpm so that the liquid temperature in the flask reaches 90°C, a polymerization reaction is carried out for 120 minutes using the completion time of the reaction solution as the reaction start time. The polymerization conversion rate after completion of the reaction is 83%, and the solid content concentration is 20% by mass. During the polymerization reaction, the monomer mixture is appropriately added in a manner such that the ratio M1 / M2 of the residual monomers becomes constant. Finally, the obtained polymer (A-9) solution is discharged from the discharge pipe 23.

[0226] [Example 10] Synthesis of polymer (A-10)

[0227] In the second step, 490 mL of propylene glycol monomethyl ether as a solvent was added to a three-necked flask (stirred tank reactor) 20, and the solid content concentration after the reaction was set to 33.3% by mass. Without adding the monomer mixed liquid, a polymer (A-10) solution was obtained in the same manner as in Example 9.

[0228] [Example 11] Synthesis of polymer (A-11)

[0229] In the second step, propylene glycol monomethyl ether as a solvent was not added to the three-necked flask (stirred tank reactor) 20, and the solid content concentration after the reaction was set to 50% by mass, and no additional monomer mixed liquid was added. Except for this, a polymer (A-11) solution was obtained in the same manner as in Example 9.

[0230] [Example 12] Synthesis of polymer (A-12)

[0231] A polymer (A-12) solution was obtained in the same manner as in Example 11 except that no additional monomer mixed liquid was added.

[0232] [Examples 13 to 16] Synthesis of polymers (A-13) to (A-16)

[0233] Polymer solutions (A-13) to (A-16) were obtained in the same manner as in Example 11 except that the capacity of the three-necked flask (stirring tank reactor) 20 was changed to 500 mL and the monomer mixture was added as shown in Table 2.

[0234] <Evaluation>

[0235] The ratio of the monomer consumption rate between the reaction stage and the reaction completion stage, and the ratio of the weight average molecular weights at the completion of the first step and the completion of the second step were determined for Examples 9 to 16 by the above-described method.

[0236] [Table 2]

[0237]

[0238] In addition, the composition ratio of the monomer M1 (CHMA) and the monomer M2 (MMA) in the system from immediately after the reaction solution was fed into the second step to a predetermined time was determined by HPLC measurement of the monomer consumption rate ratio. Figures 3A to 3H .exist Figures 3A to 3H In the figure, the horizontal axis represents time (min) and the vertical axis represents ratio (%). It can be seen that by directly adding the reaction solution from the first step to the second step, the change in monomer concentration can be suppressed, and good results can be obtained for both the monomer consumption rate ratio and the weight average molecular weight ratio.

[0239] [Industrial Applicability

[0240] According to the polymer production method and polymer production apparatus of the present invention, a polymer having high purity and highly controlled composition can be efficiently produced. Therefore, the present invention is effective in the technical field of utilizing polymers as high value-added materials.

[0241] Explanation of symbols

[0242] 1. 1B polymer manufacturing device

[0243] 10 tubular reactors

[0244] 11 Initiator tank

[0245] 12, 50 single tank

[0246] 13a, 13b, 51, 61 metering pumps

[0247] 14 manifolds

[0248] 15 pressure gauge

[0249] 16 Oil bath

[0250] 17 Coiled flow path

[0251] 18. V 2a 、V 2b 、V 2c 、V 3a 、V 3b 、V 3c 、V 4a 、V 4b 、V 4c Three-way valve

[0252] 19 Exhaust outlet

[0253] 20, 20a, 20b, 20c stirred tank reactors

[0254] 21 trough container

[0255] 22 stirring blades

[0256] 23 discharge pipe

[0257] Detectors 30a, 30b, 30c, 30d

[0258] 40 controllers

[0259] 41 Receiving Department

[0260] 42 Estimation Department

[0261] 43 Condition Determination Department

[0262] 44 Control Department

[0263] 45 Storage

[0264] 60 solvent tanks

[0265] 100 Optimization System

Claims

1. A method for producing a polymer, wherein the polymer is obtained by free radical polymerization in the coexistence of an azo polymerization initiator, two or more monomers, and a solvent, the method comprising: In the first step, the free radical polymerization is carried out in a tubular reactor; and a second step of performing the free radical polymerization in a stirred tank reactor after the first step; The maximum solid content concentration C1 based on mass in the first step max 20% by mass or more, The maximum solid content concentration C2 in the second step based on mass max Less than 80% by mass The maximum solid content concentration C1 max and the maximum solid content concentration C2 max Satisfy C1 max ≥C2 max , The temperature T1 in the tubular reactor in the first step and the temperature T2 in the stirred tank reactor in the second step satisfy |T1-T2|<20, and the units of T1 and T2 are °C.

2. The method for producing a polymer according to claim 1, wherein The maximum solid content concentration C1 max and the maximum solid content concentration C2 max Satisfy C1 max >C2 max .

3. The method for producing a polymer according to claim 1, wherein The polymerization conversion rate in the first step is 80% or less.

4. The method for producing a polymer according to claim 1, wherein The temperature T1 and the temperature T2 satisfy |T1-T2|≤10, and the units of T1 and T2 are °C.

5. The method for producing a polymer according to claim 4, wherein The temperature T1 and the temperature T2 satisfy T1≥T2, and the units of T1 and T2 are °C.

6. The method for producing a polymer according to claim 1, wherein The monomers are two or more selected from one or more monomers of (meth)acrylic acid or its ester and one or more aromatic vinyl monomers.

7. The method for producing a polymer according to claim 6, wherein The monomers include one or more monomers of (meth)acrylic acid or its ester and one or more aromatic vinyl monomers.

8. The method for producing a polymer according to claim 1, wherein The free radical polymerization is carried out in the absence of dormant species.

9. The method for producing a polymer according to claim 1, wherein The maximum solid content concentration C1 max and the maximum solid content concentration C2 max Satisfy C1 max =C2 max .

10. A polymer production apparatus for obtaining a polymer by free radical polymerization in the coexistence of an azo polymerization initiator, two or more monomers, and a solvent. The polymer production apparatus is sequentially equipped with a tubular reactor and a stirred tank reactor for respectively performing the radical polymerization. The maximum solid content concentration C1 in the tubular reactor based on mass max 30% by mass or more, The maximum solid content concentration C2 based on mass in the stirred tank reactor max Less than 50% by mass The maximum solid content concentration C1 max and the maximum solid content concentration C2 max Satisfy C1 max ≥C2 max , The temperature T1 in the tubular reactor in the first step and the temperature T2 in the stirred tank reactor in the second step satisfy |T1-T2|<20, and the units of T1 and T2 are °C.

11. An optimized system for free radical polymerization, wherein a polymer is obtained by free radical polymerization in a reaction solution comprising a polymerization initiator, a monomer, and a solvent. The optimization system for the free radical polymerization reaction has: Flow path, for the reaction liquid to flow, A feeder supplies one or more of the polymerization initiator, monomer, and solvent to the flow path, The tubular reactor and the stirred tank reactor are interposed between the starting end and the terminal end of the flow path in order from the starting end side. a detector for obtaining one or more measurement values ​​of at least the reaction liquid in the flow path, the tubular reactor, and the stirred tank reactor, and a controller connected to the flow path, the feeder, the tubular reactor, and the stirred tank reactor, and configured to control one or more process parameters of each of the flow path, the feeder, the tubular reactor, and the stirred tank reactor; The controller has: a receiving unit that receives the measurement value from the detector, an estimating unit that estimates the actual progress state of the radical polymerization based on the measured value, a condition determination unit that compares the actual progress state with the ideal progress state and determines one or more process parameters in each of the flow path, the feeder, the tubular reactor, and the stirred tank reactor within a next unit reaction time so that the actual progress state approximates the ideal progress state; and The control unit changes the process parameters of the flow path, the feeder, the tubular reactor, and the stirred tank reactor based on the determined process parameters.

12. The system for optimizing free radical polymerization according to claim 11, wherein: The condition determination unit determines the process parameters by calculating a change in the actual progress state within the next unit reaction time due to a change in the process parameters using a condition setting algorithm.

13. The system for optimizing free radical polymerization according to claim 11, wherein: The controller further includes a storage unit that stores the measured values ​​of the process parameters before and after the change, the actual progress state, and the difference between the actual progress state and the ideal progress state.

14. The system for optimizing free radical polymerization according to any one of claims 11 to 13, wherein: The measured value is obtained by online monitoring or sampling of the reaction solution.

15. The system for optimizing free radical polymerization according to any one of claims 11 to 13, wherein: The controller is provided with an interface capable of manually controlling the process parameters.

16. The system for optimizing free radical polymerization according to any one of claims 11 to 13, wherein: The measured value includes at least one of a spectrum and a viscosity of the reaction solution.

17. The system for optimizing free radical polymerization according to any one of claims 11 to 13, wherein: The process parameters include at least one of temperature, monomer input amount, azo polymerization initiator input amount, solvent input amount and stirring speed.

18. The system for optimizing free radical polymerization according to any one of claims 11 to 13, wherein: The actual progress status includes at least one of the consumption of the monomer and the weight average molecular weight of the polymer.

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