Method for producing polymer, and resin composition

Abstract

Provided is a method for producing a (meth)acrylic polymer which does not need to protect a secondary amine with a protecting group, is simple, and has a sterically hindered secondary amino group having a high conversion rate. The method for producing a (meth)acrylic polymer (A), by which a (meth)acrylic polymer (A) containing a specific amount of a structural unit derived from a monomer represented by formula (1) is produced at a polymerization conversion rate of 80% or more, comprises: a step a for adjusting a reaction mixture comprising a monomer (M) that includes a secondary amino group-containing (meta)acrylic acid ester monomer represented by formula (1), and a radical polymerization initiator; and a step b for performing polymerization through a batch reaction in a molding reactor at 60-120 °C, and continuing the polymerization until the concentration of the radical polymerization initiator in the reaction mixture reaches 1.0×10-4 mol / L or lower, wherein a specific amount of the radical polymerization initiator relative to the monomer (M) is used, and the radical polymerization initiator has a half-life τ1 / 2 of 100-3,000 seconds at the polymerization temperature.

Description

Polymer production method and resin composition

[0001] The present disclosure relates to a method for producing a polymer and a resin composition.

[0002] It is known that the photostability of a polymer can be improved by introducing a sterically hindered secondary amine such as a hindered amine into the side chain of the polymer. It has been reported that a resin emulsion obtained by copolymerizing a polymerizable hindered amine-based photostability monomer, as described in Patent Document 1, forms a coating film with excellent photostability.

[0003] Polymers containing sterically hindered secondary amines, such as hindered amines, are also useful as intermediates for obtaining polymers containing a nitroxide radical structure. In recent years, electrolyte layers containing redox compounds made of polymers containing a nitroxide radical structure have attracted attention because they are believed to electrochemically adsorb and desorb carbon dioxide repeatedly. Patent Document 2 proposes poly(2,2,6,6-tetramethylpiperidinoxy methacrylate) as a redox compound for use in the electrolyte layer of such carbon dioxide separation devices.

[0004] However, since amino groups are known to act as polymerization inhibitors and retarders, polymers with amino groups in the side chains have a problem in that they do not achieve a satisfactory conversion rate. To obtain the target polymer, a purification step to remove residual monomers is required, which is inefficient.

[0005] Non-Patent Document 1 reports that in the synthesis of poly(2,2,6,6-tetramethylpiperidyl methacrylate), an intermediate of poly(2,2,6,6-tetramethylpiperidinoxy methacrylate), the conversion rate after 48 hours is only 40%. It also describes that a method of protecting the secondary amine with a protecting group is effective in increasing the conversion rate, but this process is problematic in that it is cumbersome. Patent Document 3 proposes anionic polymerization as a method in which the secondary amine is not protected with a protecting group. However, the molecular weight is low at 5,000 or less, and the polymerization temperature is -60°C, posing challenges to industrial production.

[0006] JP 2018-172612 A JP 2018-001131 A International Publication No. 2014 / 087644

[0007] Journal of Polymer Science Part A: Polymer Chemistry, 2012, Vol. 50, pp. 1394-1407

[0008] The present disclosure has been made in view of the above background, and an object of the present disclosure is to provide a method for producing a polymer having a sterically hindered secondary amino group easily and with a high conversion rate, without the need to protect the secondary amine with a protecting group, and a resin composition.

[0009] The present inventors have conducted extensive research to achieve the above-mentioned object, and as a result have completed the present disclosure, which encompasses the following aspects: [1]: A method for producing a polymer (A), which comprises producing a polymer (A) containing 50 to 100% by mass of structural units derived from a monomer represented by the following formula (1) at a polymerization conversion rate of 80% or more, the method comprising: a step a of preparing a reaction mixture containing a monomer (M) to be used in polymerization of the polymer (A), which contains a secondary amino group-containing monomer represented by the following formula (1) (hereinafter referred to as monomer (m1)) and may contain a monomer copolymerizable with the monomer (m1) (hereinafter referred to as monomer (m2)), and a radical polymerization initiator; and a step b of carrying out polymerization by a batchwise reaction in a tank reactor at 60 to 120°C, wherein the concentration of the radical polymerization initiator in the reaction mixture is 1.0 x 10 －４ mol / L or less, the radical polymerization initiator is added simultaneously with the step a and during the step b, the radical polymerization initiator is used in a total amount of 0.01 to 1 part by mass per 100 parts by mass of the monomer (M), and the half-life τ of the radical polymerization initiator at the polymerization temperature in the step b is １／２ The method for producing polymer (A), wherein the time is 100 to 3000 seconds. (In the formula, R １ , R ２ , R ３ and R ４ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, provided that R １ and R ２At least one of R is an alkyl group having 1 to 6 carbon atoms, and R ３ and R ４ At least one of R is an alkyl group having 1 to 6 carbon atoms, １ and R ２ may be bonded to each other to form a cyclic structure, and R ３ and R ４ may be bonded to each other to form a cyclic structure, and R １１ represents a hydrogen atom or a methyl group, and X １ represents a single bond or a divalent linking group, and n is 0 or 1. [2]: The method for producing polymer (A) according to [1], wherein in step b, the radical polymerization initiator is added in portions or continuously. [3]: The final addition time TL of the radical polymerization initiator and the polymerization reaction end time TE satisfy the following mathematical formula (1): TE - TL ≧ 6τ １／２ A method for producing the polymer (A) according to [1] or [2], wherein the secondary amino group-containing monomer is a secondary amino group-containing (meth)acrylic acid ester monomer represented by the following formula (2): (In the formula, R １ , R ２ , R ３ , R ４ , R １１ and n are the same as in formula (1). ２ represents a single bond or a divalent linking group.) [5]: A resin composition comprising, relative to 100% by mass of the resin composition, 0.1 to 20% by mass of a secondary amino group-containing monomer represented by formula (1) (hereinafter referred to as monomer (m1)), and 80 to 99.9% by mass of a polymer (A) having 50 to 100% by mass of a structural unit derived from monomer (m1), wherein the resin composition does not contain a radical polymerization initiator or contains 0.01% by mass or less of a radical polymerization initiator. (In the formula, R １ , R ２ , R ３ and R ４ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, provided that R １ and R ２ At least one of R is an alkyl group having 1 to 6 carbon atoms, and R ３ and R４ At least one of R is an alkyl group having 1 to 6 carbon atoms, １ and R ２ may be bonded to each other to form a cyclic structure, and R ３ and R ４ may be bonded to each other to form a cyclic structure, and R １１ represents a hydrogen atom or a methyl group, and X １ represents a single bond or a divalent linking group, and n is 0 or 1. [6]: The resin composition according to [5], wherein the secondary amino group-containing monomer is a secondary amino group-containing (meth)acrylic acid ester monomer represented by the following formula (2) (hereinafter referred to as monomer (m11)), and the polymer (A) is a (meth)acrylic polymer (A1) having 50 to 100 mass % of structural units derived from monomer (m11): (In the formula, R １ , R ２ , R ３ , R ４ , R １１ and n are the same as in formula (1). ２ represents a single bond or a divalent linking group.

[0010] The present disclosure has the excellent effect of providing a method for producing a polymer having a sterically hindered secondary amino group with a simple and high conversion rate, and a resin composition, without the need to protect the secondary amine with a protecting group.

[0011] An example of an embodiment to which the present disclosure is applied will be described below. The present disclosure is not limited to this embodiment, and other embodiments may also fall within the scope of the present disclosure as long as they conform to the spirit of the present disclosure. Furthermore, the numerical values ​​"A to B" specified in this specification include numerical value A and numerical value B. The numerical values ​​specified in this specification are values ​​determined by the methods disclosed in the embodiments or examples. Unless otherwise noted, the various components appearing in this specification may each be used independently alone or in combination of two or more types. (Meth)acrylic is a general term for acrylic and methacrylic.

[0012] The present disclosure relates to a method for producing polymer (A), which produces polymer (A) containing 50 to 100% by mass of structural units derived from a monomer represented by formula (1) below at a polymerization conversion of 80% or more, and includes the following steps a and b. The method for producing polymer (A) (hereinafter also referred to as the present production method) involves polymerization by a batch reaction in a tank reactor. The polymerization conversion refers to a value determined by the method described in the Examples below. In formula (1), R １ , R ２ , R ３ and R ４ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, provided that R １ and R ２ At least one of R is an alkyl group having 1 to 6 carbon atoms, and R ３ and R ４ At least one of R is an alkyl group having 1 to 6 carbon atoms, １ and R ２ may be bonded to each other to form a cyclic structure, and R ３ and R ４ may be bonded to each other to form a cyclic structure, and R １１ represents a hydrogen atom or a methyl group, and X １ represents a single bond or a divalent linking group, and n is 0 or 1.

[0013] Step a is a step of preparing a reaction mixture containing a monomer (hereinafter referred to as monomer (M)) to be used in the polymerization of polymer (A), which contains a secondary amino group-containing monomer represented by formula (1) (hereinafter referred to as monomer (m1)) and may contain a monomer copolymerizable with monomer (m1) (hereinafter referred to as monomer (m2)), and a radical polymerization initiator. Here, monomer (M) is a general term for all monomers used in the polymerization system. In the case of homopolymerization, it refers to a single type of monomer (m1), and in the case of copolymerization, it refers to a mixture of monomers. Copolymers include polymers containing two or more types of monomer (m1). In addition to the above-mentioned embodiments, copolymers include polymers obtained using one or more types of monomer (m1) and one or more types of monomer (m2) as a monomer mixture. The reaction mixture refers to all compounds charged into a tank-type reactor, including the monomer mixture, the radical polymerization initiator, and optionally optional components. Optional components include, for example, chain transfer agents, solvents, and additives within the scope of the present disclosure.

[0014] In step b, polymerization is carried out by a batch reaction using a tank reactor at 60 to 120°C, and the concentration of the radical polymerization initiator in the reaction mixture is adjusted to 1.0 x 10 －４ mol / L or less. －４ The phrase "polymerize until the concentration reaches 1000 mol / L or less" means that the concentration is equal to or less than the above concentration, and does not mean that the concentration determines the end point of polymerization. In step b, no monomer (M) is added.

[0015] The radical polymerization initiator is added simultaneously with the step a and during the step b. The radical polymerization initiator concentration is a value calculated by the following formula (2): I=I ０ ×exp(-k ｄ t) Equation (2) where I is the radical polymerization initiator concentration at time t, I ０ is the concentration of the radical polymerization initiator at the time of addition, k ｄ is the decomposition rate constant of the radical polymerization initiator at the polymerization temperature in step b. When the radical polymerization initiator is added in portions or continuously, I is the decomposition rate constant of each I ０ ×exp(-k ｄ t).

[0016] The radical polymerization initiator is a compound that generates reactive radicals by irradiation with ultraviolet light or visible light or by heating, and initiates a polymerization reaction. At the polymerization temperature in step b, the radical polymerization initiator has a half-life τ １／ It is important to use a radical polymerization initiator having a half-life τ of 100 to 3000 seconds at the reaction temperature. １／２ The amount of radical polymerization initiator used in step a is preferably 0.005 to 0.5 parts by mass per 100 parts by mass of the monomer (M).

[0017] In order to obtain a polymer (A) containing 50 to 100% by mass of structural units derived from the monomer represented by formula (1), the quantitative ratio of the monomer (m1) to the monomer (m2) is determined in step a, taking into consideration the polymerization rates of the monomers (m1) and (m2). When the polymerization rate is substantially the same regardless of the type of monomer used, the ratio is adjusted so that the monomer (m1) represented by formula (1) accounts for 50 to 100% by mass in 100% by mass of the monomer (M).

[0018] The polymer (A) may be a homopolymer or a copolymer. In the case of a copolymer, the form thereof is not limited. For example, it may be a block copolymer or a random copolymer.

[0019] As described above, the content of the structural units derived from the monomer (m1) in the polymer (A) is 50 to 100% by mass, and the lower limit is preferably 60% by mass, more preferably 70% by mass, and even more preferably 90% by mass. The content of the structural units derived from the monomer (m1) in 100% by mass of the polymer (A) may be 100% by mass.

[0020] In 100% by mass of the polymer (A), the structural unit derived from the monomer (m2) is 50% by mass or less, and the upper limit is preferably 40% by mass, more preferably 30% by mass, and even more preferably 10% by mass.

[0021] When the polymerization rate of the monomer (m1) is substantially the same as that of the monomer (m2) used, the content of the monomer (m1) in the monomer mixture is 50 to 100% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. 100% by mass of the monomer (m1) may be used. The content of the monomer (m2) in the monomer mixture (the total amount when multiple types of monomers are used) is 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less.

[0022] Suitable examples of the monomer (m1) include secondary amino group-containing (meth)acrylic acid ester monomers such as 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine; secondary amino group-containing (meth)acrylamide monomers such as 4-(meth)acrylamide-2,2,6,6-tetramethylpiperidine; secondary amino group-containing vinyl ether monomers such as 4-(ethenyloxy)-2,2,6,6-tetramethylpiperidine; secondary amino group-containing vinyl monomers such as 2,2,6,6-tetramethyl-4-vinylpiperidine; and the like.

[0023] The secondary amino group-containing monomer of the present disclosure is preferably a secondary amino group-containing (meth)acrylic acid ester monomer represented by the following formula (2) (hereinafter referred to as monomer (m11)). (In the formula, R １ , R ２ , R ３ , R ４ , R １１ and n are the same as in formula (1). ２ represents a single bond or a divalent linking group.

[0024] When the polymerization rate of the monomer (m11) is substantially the same as that of the monomer (m2) used, the content of the monomer (m11) in the monomer mixture is 50 to 100% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. 100% by mass of the monomer (m11) may be used. The content of the monomer (m2) in the monomer mixture (the total amount when multiple types of monomers are used) is 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less.

[0025] Preferable examples of the monomer (m11) include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, and 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine. crotonoylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine.

[0026] Suitable examples of the monomer (m2) include alkyl methacrylate esters having an alkyl group having two or more carbon atoms, such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; aryl methacrylate esters such as phenyl methacrylate; cycloalkyl methacrylate esters such as cyclohexyl methacrylate and norbornenyl methacrylate; alkyl methacrylate esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; aryl acrylate esters such as phenyl acrylate; cycloalkyl acrylate esters such as cyclohexyl acrylate and norbornenyl acrylate; styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene; acrylamide, methacrylamide; acrylonitrile, methacrylonitrile; and vinyl monomers having only one polymerizable alkenyl group in one molecule, such as methacrylic acid and acrylic acid.

[0027] Suitable examples of the radical polymerization initiator include t-hexylperoxyisopropyl monocarbonate, t-hexylperoxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1,1-bis(t-hexylperoxy) ) cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2-methylbutyronitrile), and dimethyl 2,2'-azobis(2-methylpropionate) are preferred; and t-hexylperoxy 2-ethylhexanoate, 1,1-bis(t-hexylperoxy)cyclohexane, and dimethyl 2,2'-azobis(2-methylpropionate) are also preferred. The radical polymerization initiators can be used alone or in combination of two or more.

[0028] The total amount of radical polymerization initiator used is 0.01 to 1 part by mass per 100 parts by mass of monomer (M). It is preferably 0.02 to 0.9 parts by mass, more preferably 0.03 to 0.8 parts by mass, and even more preferably 0.05 to 0.7 parts by mass. If the amount is less than 0.01 part by mass, the polymerization conversion rate will be low. On the other hand, if the amount is more than 1 part by mass, there is a concern that side reactions will occur due to residual radical polymerization initiator when the resulting polymer (A) is used as a component of an electrochemical device.

[0029] In the present production method, the polymerization temperature in step b refers to the temperature of the liquid in the layer reactor when the polymerization reaction is carried out in the tank reactor, and is 60 to 120° C., preferably 65 to 115° C., and particularly preferably 70 to 110° C. When the polymerization temperature is in the above range, the polymerization conversion rate can be increased in a short period of time.

[0030] The half-life τ of the radical polymerization initiator at the polymerization temperature １／２is 100 to 3000 seconds, preferably 150 to 2800 seconds, and more preferably 200 to 2700 seconds. １／２ is a value calculated by the following formulas (3) and (4). １／２ = [ln(2)] / k ｄ Formula (3) k ｄ = A × exp(-E ａ / RT) Equation (4) Note that equation (3) is obtained by adding I = (1 / 2)I to equation (2). ０ and convert it to natural logarithm. A is the frequency factor, E ａ is the activation energy, R is the gas constant, T is the polymerization temperature (absolute temperature (K)), k ｄ is the decomposition rate constant of the radical polymerization initiator at absolute temperature T.

[0031] In this production method, the radical polymerization initiator concentration in the reaction mixture at the end of the polymerization reaction is set to 1.0×10 －４ mol / L or less. －４ mol / L or less, preferably 0.8×10 －４ The concentration of the radical polymerization initiator in the reaction mixture at the end of the polymerization reaction is preferably 1.0×10 mol / L or less. －４ By setting the concentration to 1000 mol / L or less, the amount of radical polymerization initiator in the obtained polymer (A) is reduced, making it useful for use as a component of an electrochemical device. Note that the end of the polymerization reaction refers to the time when heating is stopped to terminate the polymerization reaction in the tank-type reactor in this production method. In other words, it refers to the time when cooling of the liquid in the tank is started.

[0032] A chain transfer agent can be suitably used as an optional component of the reaction mixture. Examples of chain transfer agents include alkyl mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 1,4-butanedithiol, 1,6-hexanedithiol, ethylene glycol bisthiopropionate, butanediol bisthioglycolate, butanediol bisthiopropionate, hexanediol bisthioglycolate, hexanediol bisthiopropionate, trimethylolpropane tris-(β-thiopropionate), and pentaerythritol tetrakisthiopropionate; α-methylstyrene dimer; and terpinolene. Among these, monofunctional alkyl mercaptans such as n-octyl mercaptan and n-dodecyl mercaptan are preferred. These chain transfer agents can be used alone or in combination of two or more. The amount of the chain transfer agent used is preferably 0.1 to 1 part by mass, more preferably 0.012 to 0.48 parts by mass, and even more preferably 0.3 to 0.6 parts by mass, based on 100 parts by mass of the monomer mixture.

[0033] When it is necessary to adjust the viscosity of the liquid in the tank reactor in which the raw materials are dissolved, a solvent can be included in the reaction raw materials. As the solvent, aromatic hydrocarbons such as benzene, toluene, and ethylbenzene are preferred. These solvents are used alone or in combination of two or more. The amount of solvent used is preferably 1,000 parts by mass or less, more preferably 500 parts by mass or less, and even more preferably 300 parts by mass or less, per 100 parts by mass of the monomer mixture (M). There is no lower limit to the amount of solvent used as long as it is consistent with the above-mentioned purpose, but from the viewpoint of the solubility of the monomer in the solvent, a lower limit of 50 parts by mass is preferred.

[0034] In the present production method, the method for adding the radical polymerization initiator is not particularly limited, but it is preferable to add it in portions or continuously in step b.

[0035] When the radical polymerization initiator is added in portions, there are no particular limitations on the number of portions or the amount added per portion. However, from the viewpoint of efficiently increasing the polymerization conversion rate, it is preferable that the concentration of the radical polymerization initiator added first in the tank is 1.0 × 10 －４It is preferable to add the next radical polymerization initiator before the concentration of the radical polymerization initiator in the tank reaches 1000 mol / L or less. The concentration of the previously added radical polymerization initiator in the tank is calculated by the above-mentioned formula (2).

[0036] In this production method, the polymerization conversion rate at the end of the polymerization reaction is 80% or more, preferably 85% or more, and more preferably 90% or more. According to this production method, polymerization is carried out via steps a and b, so that a polymer having a sterically hindered secondary amino group can be obtained at a high conversion rate without protecting the secondary amine with a protecting group or without a step of removing the monomer. Note that, within the scope of the present disclosure, steps other than steps a and b (e.g., a purification step, a step of removing aggregates) may be included. Note that the step of protecting the secondary amine with a protecting group and the step of removing the monomer are not excluded.

[0037] In this production method, it is preferable that the final addition time TL of the radical polymerization initiator in step b and the polymerization reaction end time TE satisfy the relationship of the following mathematical formula (1): TE-TL≧6τ １／２ Formula (1) By setting TE-TL within the above range, the amount of radical polymerization initiator in the resulting resin composition is reduced, making it useful for use as a member of an electrochemical device.

[0038] The weight average molecular weight (Mw) of the polymer (A) obtained by this production method is not particularly limited, but is preferably 1,000 to 200,000. The lower limit of the Mw is more preferably 2,000, even more preferably 3,000, particularly preferably 4,000, and most preferably 5,000. The upper limit of the Mw is more preferably 180,000, even more preferably 150,000, particularly preferably 130,000, and most preferably 100,000. When the Mw is 1,000 or more, the electrochemical stability of the polymer (A) is improved. When the Mw is 200,000 or less, the film formability of the polymer (A) is improved when used as a component of an electrochemical device.

[0039] The resin composition of the present disclosure contains, based on 100% by mass of the resin composition, 0.1 to 20% by mass of a secondary amino group-containing monomer represented by formula (1) (hereinafter referred to as monomer (m1)) and 80 to 99.9% by mass of a polymer (A) having 50 to 100% by mass of structural units derived from monomer (m1), and does not contain a radical polymerization initiator or contains 0.01% by mass or less of a radical polymerization initiator.

[0040] In the resin composition of the present disclosure, it is preferable that the secondary amino group-containing monomer is a secondary amino group-containing (meth)acrylic acid ester monomer (monomer (m11)) represented by formula (2), and the polymer (A) is a (meth)acrylic polymer (A1) having 50 to 100 mass% of structural units derived from the monomer (m11).

[0041] The content of the monomer (m11) in the resin composition of the present disclosure is preferably 0.1 to 20 mass %, and the content of the (meth)acrylic polymer (A1) is preferably 80 to 99.9 mass %.

[0042] The present disclosure will now be described in more detail with reference to examples. However, the present disclosure is not limited to these examples. Measurements of physical properties and the like were carried out by the following methods.

[0043] (Weight-average molecular weight (Mw), number-average molecular weight (Mn), molecular weight distribution (Mw / Mn)) The average molecular weights (Mw, Mn) and molecular weight distribution (Mw / Mn) of the polymer were determined by gel permeation chromatography (GPC). A solution prepared by mixing triethylamine with tetrahydrofuran to a concentration of 200 mM / L was used as the eluent. Two TSKgel SuperMultipore HZM-M columns manufactured by Tosoh Corporation and a Super HZ4000 column connected in series were used as the column. The GPC apparatus used was an HLC-8320 (product number) manufactured by Tosoh Corporation equipped with a differential refractive index detector (RI detector). A sample solution was prepared by dissolving 8 mg of the resin to be measured in 5 mL of a mixed solution of tetrahydrofuran and triethylamine. The column oven temperature was set to 40°C, and 20 μL of sample solution was injected into the instrument at an eluent flow rate of 0.35 mL / min, and a chromatogram was measured. Ten standard polymethyl methacrylates with molecular weights ranging from 400 to 5,000,000 were measured by GPC, and a calibration curve showing the relationship between retention time and molecular weight was created. Based on this calibration curve, the average molecular weights (Mw, Mn) and molecular weight distribution (Mw / Mn) of each of the polymers to be measured were determined.

[0044] (Polymerization Conversion Rate) After the polymerization reaction was completed, 1 mg of the reaction mixture was dissolved in 2 mL of deuterated chloroform. １ H-NMR was measured to determine the integral value (IM) of the protons of the vinylic double bond of the LA-87 monomer (6.0-6.2 ppm) and the integral value (IP) of the protons adjacent to the methine carbon of the side chain of the polyLA-87 polymer (5.0-5.3 ppm), and the polymerization conversion rate was calculated using the following formula: Polymerization conversion rate (%) = IP / (IM+IP) × 100

[0045] (Raw Materials) The following raw materials were used in the following Examples and Comparative Examples. LA-87: "ADEKA STAB LA-87" manufactured by ADEKA CORPORATION (compound name: 2,2,6,6-tetramethyl-4-piperidyl methacrylate) Perbutyl D: "Perbutyl D" manufactured by NOF Corporation (compound name: di-tert-butyl peroxide)

[0046] Example 1 100 parts by mass of toluene and 100 parts by mass of LA-87 were placed in an autoclave equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a monomer inlet tube, and a sampling tube, and the inside of the vessel was replaced with nitrogen. The vessel was heated to 100°C, and a solution prepared by dissolving 0.02 parts by mass of azobisisobutyronitrile (AIBN) in 0.05 parts by mass of toluene was injected with nitrogen to initiate polymerization. One hour after the start of polymerization, a solution prepared by dissolving 0.02 parts by mass of AIBN in 0.05 parts by mass of toluene was injected with nitrogen. This additional injection of the initiator solution was repeated four times every hour (including the start of polymerization, for a total of five initiator injections), and the reaction was continued for another hour. After one hour, heating was stopped, and this point was designated as the end of the polymerization reaction. The reaction vessel was then cooled to room temperature. The evaluation results are shown in Table 1.

[0047] Examples 2 to 7, Comparative Examples 1 to 6 Polymerization reactions were carried out in the same manner as in Example 1, except that the formulation and conditions were changed as shown in Table 1. The evaluation results are shown in Table 1.

[0048]

[0049] When the radical polymerization initiator was added in a lump in an amount exceeding 1 part by mass per 100 parts by mass of the monomer (M), the polymerization conversion rate was low and productivity was poor, as shown in Comparative Examples 1 to 3. It was confirmed that the conversion rate was low in Comparative Example 4. Furthermore, when the polymerization temperature in step b exceeded 120°C, the polymerization conversion rate was low and productivity was poor, as shown in Comparative Example 5. Furthermore, the half-life τ of the radical polymerization initiator １／２ When the value of the polymerization initiator exceeds 3,000, the polymerization conversion rate is low and productivity is poor, as shown in Comparative Example 6. On the other hand, according to the present production method, as shown in Examples 1 to 7, it was confirmed that the polymerization conversion rate can be increased in a relatively short time and productivity is excellent. Furthermore, according to the present production method, as shown in Examples 1 to 7, the amount of radical polymerization initiator remaining in the reaction solution after completion of the polymerization reaction is small, and it was confirmed that the polymer obtained by the present production method is useful as a component of an electrochemical device with little concern about side reactions.

[0050] The polymer and resin composition of the present disclosure can be suitably used as a coating film or the like having excellent light stability. The polymer of the present disclosure is also useful as an intermediate for obtaining a polymer containing a nitroxide radical structure. An electrolyte layer containing a redox compound made of a polymer containing a nitroxide radical structure is attracting attention because it is believed to repeatedly electrochemically adsorb and desorb carbon dioxide.

[0051] This application claims priority based on Japanese Patent Application No. 2023-174711, filed October 6, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A method for producing a polymer (A) containing 50 to 100% by mass of a structural unit derived from a monomer represented by the following formula (1) at a polymerization conversion rate of 80% or more, the method comprising the steps of: a step a of preparing a reaction mixture containing a monomer (M) to be used in polymerization of the polymer (A), the monomer (M) containing a secondary amino group-containing monomer represented by the following formula (1) (hereinafter referred to as monomer (m1)) and optionally containing a monomer copolymerizable with the monomer (m1) (hereinafter referred to as monomer (m2)), and a radical polymerization initiator; and a step b of carrying out polymerization at 60 to 120°C by batchwise reaction in a tank reactor, the radical polymerization initiator concentration in the reaction mixture being adjusted to 1.0 x 10 －４ mol / L or less, the radical polymerization initiator is added simultaneously with the step a and during the step b, the radical polymerization initiator is used in a total of 0.01 to 1 part by mass per 100 parts by mass of the monomer (M), and the half-life τ of the radical polymerization initiator at the polymerization temperature in the step b is １／２ The method for producing the polymer (A), wherein the time is 100 to 3000 seconds. (In the formula, R １ , R ２ , R ３ and R ４ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, provided that R １ and R ２ At least one of R is an alkyl group having 1 to 6 carbon atoms, and R ３ and R ４ At least one of R is an alkyl group having 1 to 6 carbon atoms; １ and R ２ may be bonded to each other to form a cyclic structure, R ３ and R ４ may be bonded to each other to form a cyclic structure, R １１ represents a hydrogen atom or a methyl group, and X １ represents a single bond or a divalent linking group, and n is 0 or 1.

2. The method for producing the polymer (A) according to claim 1, wherein in step b, the radical polymerization initiator is added in portions or continuously.

3. The final addition time TL of the radical polymerization initiator and the polymerization reaction end time TE are expressed by the following formula (1): TE-TL≧6τ １／２ The method for producing the polymer (A) according to claim 1 , wherein the relationship is represented by the mathematical formula (1).

4. The method for producing polymer (A) according to claim 1, wherein the secondary amino group-containing monomer is a secondary amino group-containing (meth)acrylic acid ester monomer represented by the following formula (2): (In the formula, R １ , R ２ , R ３ , R ４ , R １１ and n are the same as in formula (1). ２ represents a single bond or a divalent linking group.

5. A resin composition comprising, based on 100% by mass of the resin composition, 0.1 to 20% by mass of a secondary amino group-containing monomer represented by formula (1) (hereinafter referred to as monomer (m1)) and 80 to 99.9% by mass of a polymer (A) having 50 to 100% by mass of a structural unit derived from monomer (m1), and which does not contain a radical polymerization initiator or contains 0.01% or less by mass of a radical polymerization initiator. (In the formula, R １ , R ２ , R ３ and R ４ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, provided that R １ and R ２ At least one of R is an alkyl group having 1 to 6 carbon atoms, and R ３ and R ４ At least one of R is an alkyl group having 1 to 6 carbon atoms; １ and R ２ may be bonded to each other to form a cyclic structure, R ３ and R ４ may be bonded to each other to form a cyclic structure, R １１ represents a hydrogen atom or a methyl group, and X １ represents a single bond or a divalent linking group, and n is 0 or 1.

6. The resin composition according to claim 5, wherein the secondary amino group-containing monomer is a secondary amino group-containing (meth)acrylic acid ester monomer represented by the following formula (2) (hereinafter referred to as monomer (m11)), and the polymer (A) is a (meth)acrylic polymer having 50 to 100 mass % of a structural unit derived from monomer (m11). (In the formula, R １ , R ２ , R ３ , R ４ , R １１ and n are the same as in formula (1). ２ represents a single bond or a divalent linking group.

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