JP2006312696A - N-methacryloylaziridine-based polymer and method for producing the polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new methacrylamide-based polymer utilizable in wide applications such as a system for curing (cross-linking) an adhesive, a coating material, a sealing agent and the like; and to provide a method for producing the polymer. <P>SOLUTION: The N-methacryloylaziridine-based polymer has a repeating unit represented by general formula (I) (wherein, R<SB>1</SB>to R<SB>4</SB>are each independently a hydrogen atom, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a s-butyl group and a t-butyl group; with the proviso that all of R<SB>1</SB>to R<SB>4</SB>are not the hydrogen atom), 3,000-1,000,000 number average molecular weight (M<SB>n</SB>), and ≤1.5 molecular weight distribution (M<SB>w</SB>/M<SB>n</SB>; M<SB>w</SB>is a weight average molecular weight). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel polymer having a reactive aziridinyl group and a method for producing the same. The present invention relates to coalescence and a manufacturing method thereof.

  The polymerizability of various monomers has been confirmed for a long time. Among them, there are some reports on the polymerizability of N, N-dialkylmethacrylamide derivatives, but their inability to polymerize has been clarified. Non-Patent Document 1 examines radical polymerization and anionic polymerization of N, N-dialkylmethacrylic derivatives. N, N-dimethylmethacrylamide and N, N-diethyl, N-methyl-N-phenyl, N-ethyl -N-phenyl, N, N-diphenyl, N-piperidyl, N-morpholyl of all methacrylamide derivatives were not obtained by radical polymerization and anionic polymerization, the monomer was recovered Reporting.

In Non-Patent Document 2, the polymerizability of N, N-dimethylmethacrylamide and N-methacryloyl-N′-methylpiperazine is studied, and the polymer is obtained by polymerization in an aqueous solution using a redox initiator. Although it is reported that it was obtained, there is no detailed description such as yield and molecular weight of the obtained polymer. Further, anionic polymerization of the monomer has been studied, and although an initiation reaction occurs, a homopolymer cannot be obtained. Thus, it has become general recognition that N, N-dialkylmethacrylamides do not homopolymerize.
Under such a background, as seen in Patent Document 1, only N, methacryloylaziridine-based compounds are attempted to be copolymerized with α, β-ethylenically unsaturated compounds.

  Non-patent document 3 is the only report that a polymer was obtained from an N, N-dialkylmethacrylamide derivative. In this non-patent document 3, radical polymerization and anionic polymerization of N-methacryloylaziridine are studied, and it is reported that a polymer was obtained in a high yield in any case. However, even in this report, a detailed analysis of the polymer such as molecular weight and molecular weight distribution has not been performed, and no detailed discussion has been made about the polymer obtained from N-methacryloylaziridine alone.

Yokota Kenji, Oda Junichiro, Occupational Chemical Journal, 73, 224 (1970) X. Xie, T .; E. Hogen-Esch, Macromolecules, 29, 1740 (1996). Y. Okamoto, H .; Yuki, J. et al. Polym. Sci. Polym. Chem. Ed. , 19, 2647 (1981) Japanese Examined Patent Publication No. 63-48881

  The present invention aims to synthesize N-methacryloylaziridine-based polymers with a narrow molecular weight distribution, controlled molecular weight, and a clear chemical structure by polymerizability of N-methacryloylaziridine-based compounds, particularly anionic polymerization. It is an object of the present invention to establish a novel N-methacryloylaziridine-based polymer that can be used in a wide range of applications such as a curing (crosslinking) system for paints and sealants, and a method for producing the same.

As a result of various studies to solve the above problems, the present inventors polymerized a methacrylamide compound having an aziridine ring in which two alkyl groups of N, N-dialkyl are bonded to each other to form a ring. The polymer thus obtained has a narrow molecular weight distribution, a controlled molecular weight, and a clear chemical structure, and has reached the present invention.
That is, the present invention provides the following (1) to (4) N-methacryloylaziridine-based polymers and methods for producing the polymers.

(1) It has a repeating unit represented by the following general formula (I), has a number average molecular weight (M _n ) of 3,000 to 1,000,000, and a molecular weight distribution (M _w / M _n , N-methacryloylaziridine polymer having a weight average molecular weight ( _Mw ) of 1.5 or less.

Wherein R _{1 to} R ₄ are each independently selected from a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group. And all of R _{1 to} R ₄ are not hydrogen atoms.)

(2) The N-methacryloylaziridine polymer of (1) having a molecular weight distribution (M _w / M _n ) of 1.2 or less.

(3) The method for producing an N-methacryloylaziridine polymer according to (1) or (2), wherein an addition polymerization of an N-methacryloylaziridine compound represented by the following general formula (II) is performed.

Wherein R _{1 to} R ₄ are each independently selected from a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group. And all of R _{1 to} R ₄ are not hydrogen atoms.)

(4) The method for producing an N-methacryloylaziridine polymer according to (3), wherein the addition polymerization is anionic polymerization.

  A novel polymer having a clear primary structure and a reactive aziridinyl group is obtained, and can be used in a wide range of industrial applications such as curing (crosslinking) systems such as adhesives, paints, and sealing agents.

  The N-methacryloylaziridine-based polymer of the present invention has a repeating unit represented by the following general formula (I).

In the formula, R _{1 to} R ₄ are each independently selected from hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group. And R _{1 to} R ₄ are not all hydrogen atoms. R _{1 to} R ₄ may be the same or different.

The number average molecular weight (M _n ) of the N-methacryloylaziridine-based polymer of the present invention is 3,000 to 1,000,000, preferably 10,000 to 500, from the viewpoint of purification and handling properties of the polymer. , 000.

Further, the molecular weight distribution (M _w / M _n , M _w is a weight average molecular weight) of the N-methacryloylaziridine polymer of the present invention needs to be 1.5 or less, preferably 1.2 or less. By setting the molecular weight distribution (M _w / M _n ) to 1.5 or less, variations in basic physical properties such as solubility of the polymer are reduced, so that application development is expected for various applications. In particular, when the molecular weight distribution (M _w / M _n ) is narrowed to 1.2 or less, the content of the aziridinyl group in the polymer becomes clearer, so that adhesives, paints, sealing agents, etc. This makes it possible to design a more precise curing (crosslinking) system.

Next, a method for producing the N-methacryloylaziridine polymer of the present invention will be described.
The N-methacryloylaziridine polymer of the present invention is produced by addition polymerization of an N-methacryloylaziridine compound monomer represented by the general formula (II).

In the formula, R _{1 to} R ₄ are each independently selected from hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group. And R _{1 to} R ₄ are not all hydrogen atoms. R _{1 to} R ₄ may be the same or different.

The monomer of this polymer, that is, the N-methacryloylaziridine compound monomer represented by the general formula (II) can be produced by a known method.
In the “Method for producing N-substituted acrylamide or methacrylamide” of Japanese Examined Patent Publication No. 4-65059 and the references cited therein, the N-methacryloylaziridine compound monomer is represented by the following general formula (III). Methacrylic acid halide

(Wherein X represents a chlorine atom or a bromine atom)
Aziridine compound (IV) represented by the following general formula

And trialkylamines or the like as reaction aids, which can be produced by reaction.
Specific examples of the N-methacryloyl aziridine compound of the present invention include N-methacloyl-2-methylaziridine, N-methacloyl-2-ethylaziridine, N-methacloyl-2,2-dimethylaziridine, N-methacloyl. Examples include -2,3-dimethylaziridine, N-methacryloyl-2- (n-propyl) aziridine, N-methacloyl-2- (n-butyl) aziridine and the like.

  In the production of the N-methacryloylaziridine-based polymer of the present invention, it is necessary to use a high-purity monomer as a raw material, and those purified by vacuum distillation or vacuum distillation are preferably used. In this purification distillation, it is preferable to use a polymerization inhibitor such as methylene blue or calcium hydride.

  The polymerization method that can be employed in the addition polymerization step is not necessarily limited to a specific polymerization method. For example, a normal radical polymerization method, a SFRP (stable free radical polymerization) method, a RAFT (Reversible Addition-Fragmentation Transfer) weight is used. Legal methods, ATRP (atom transfer radical polymerization) method, GTP (group transfer polymerization) method, anionic polymerization method and the like can be mentioned. Among these, the anionic polymerization method is preferable from the viewpoint that the obtained polymer has a narrow molecular weight distribution and the polymerization conversion rate of the monomer is high.

  As a polymerization method, when a radical polymerization method such as a normal radical polymerization method, SFRP method, RAFT polymerization method, ATRP method, GTP method or the like is employed, a known polymerization initiator system can be used in each polymerization method, For example, as an initiator used in the radical polymerization method, 2,2′-azobisisobutyronitrile can be given (see J. Am. Chem. Soc., 123, 7180-7181 (2001)).

  The polymerization initiator used in the anionic polymerization method is not necessarily limited to a specific one, and a known anionic polymerization initiator can be used. For example, an organic lithium compound, an organic sodium compound, an organic potassium And organic metal compounds such as organic magnesium compounds.

  Among these anionic polymerization initiators, alkyl lithium, aryl lithium, alkyl sodium, aryl sodium, alkyl potassium, and aryl potassium are preferred in that the polymerization initiation efficiency is high and the polymerization reaction proceeds smoothly. s-butyllithium, t-butyllithium, 1,1-diphenyl-3-methylpentyllithium (1: 1 adduct of s-butyllithium and 1,1-diphenylethylene), sodium naphthalene, potassium naphthalene, diphenylmethylpotassium Is particularly preferred.

  As an anionic polymerization initiator, one kind of the above polymerization initiators may be used alone, or two or more kinds may be used in combination. Although the usage-amount of a polymerization initiator is not necessarily limited, It is using a polymerization initiator in the ratio used in the range of 0.01-5 mol with respect to a total of 100 mol of the monomer to be used, It is preferable from the viewpoint that the intended polymer can be produced smoothly.

  In the polymerization, it is not necessary to use a solvent, but it is preferably used in order to make the polymerization system uniform. Examples of such solvents include aliphatic hydrocarbons such as pentane, n-hexane, and octane; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane; benzene, toluene, ethylbenzene, and xylene. Aromatic ethers such as diethyl ether, tetrahydrofuran, 1,4-dioxane, anisole, diphenyl ether and the like. Among these, the ether compound is preferably used from the viewpoint of excellent solubility of the polymerization initiator, raw material monomer, organic compound as a co-catalyst, polymer, etc., diethyl ether, tetrahydrofuran 1,4-dioxane is particularly preferred. These organic solvents may be used alone or in combination of two or more.

  In anionic polymerization, a polymerization additive usually used in the polymerization system may be added for the purpose of allowing the polymerization to proceed rapidly. Examples of the polymerization additive include Lewis acids such as dimethyl zinc, diethyl zinc, triethyl aluminum, trihexyl aluminum, trioctyl aluminum, triethyl boron, triphenyl boron, dimethyl ether, dimethoxyethane, diethoxyethane, 12-crown- Ether compounds such as 4,15-crown-5,18-crown-6; trimethylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine , 1,1,4,7,10,10-hexamethyltriethylenetetramine, pyridine, 2,2'-dipyridyl and the like organic nitrogen compounds; triethylphosphine, triphenylphosphine, 1,2-bis (diphenylphosphino) Organophosphorus compounds such as ethane Inorganic salts such as lithium chloride, sodium chloride and potassium chloride; Alkoxide compounds such as lithium (2-methoxyethoxy) ethoxide and potassium t-butoxide; A grade salt etc. are mentioned. These polymerization additives may be used alone or in combination of two or more. The addition amount of the polymerization additive is 1.0 to 50 mol, preferably 2.5 to 25 mol, relative to 1.0 mol of the anionic polymerization initiator.

  The polymerization reaction is preferably carried out under a high vacuum or in an inert gas atmosphere such as nitrogen, argon, helium, etc., regardless of the polymerization mode (radical polymerization, anionic polymerization, etc.). Moreover, it is preferable to perform the polymerization under sufficient stirring conditions so that the polymerization reaction system becomes uniform. The temperature of the reaction system during the polymerization is usually −100 to 100 ° C., preferably −80 to 80 ° C.

In the present invention, for example, the polymerization reaction can be stopped by adding a polymerization terminator to the reaction mixture at the stage where a polymer having a desired molecular weight is formed by the polymerization reaction. As the polymerization terminator, for example, a protic compound such as methanol, isopropanol, acetic acid, hydrochloric acid in methanol, or the like can be used. Although the usage-amount of a polymerization terminator is not specifically limited, Generally, it is preferable to use in the ratio used in the range of 1-100 mol with respect to 1 mol of used polymerization initiators.
The method for separating and obtaining the target N-methacryloylaziridine polymer from the reaction mixture after stopping the polymerization reaction is not particularly limited, and any method according to a known method can be employed. For example, a method of pouring the reaction mixture into a poor solvent of the polymer to obtain the polymer by precipitation, a method of obtaining the polymer by distilling off the solvent from the reaction mixture, or the like can be employed.

In the production method of the N-methacryloylaziridine polymer of the present invention, complicated steps such as introduction of a protecting group into the monomer and deprotection of the polymer are unnecessary, and only the vinyl polymer is efficiently produced. can do.
The N-methacryloylaziridine-based polymer of the present invention has a structure in which a double bond of a methacryloyl group is vinyl polymerized without the aziridine ring being opened during the polymerization. Since the aziridine ring is retained, it can be used in a wide range of applications such as curing (crosslinking) systems such as adhesives, paints, and sealing agents.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the measuring method of the physical-property value in each Example is as follows.
In (a) and (b), a nuclear magnetic resonance apparatus (NMR) having the following specifications was used.
Equipment: BRUKER GPX300 (300 MHz)
Heavy solvent: CDCl ₃ ( ¹ H: 7.26 ppm, ¹³ C: 77.1 ppm)

(A) Confirmation of chemical structure In order to confirm the chemical structure of the monomer (N-methacryloyl-2-methylaziridine) and its polymer, ¹ H-NMR and ¹³ C-NMR of each sample were measured.
(B) Number average molecular weight (M _n )
It was calculated from the area ratio between the terminal functional group moiety and the functional moiety included in the repeating structural units of the polymer obtained from the ¹ H-NMR measurement of the polymerization initiator.
In addition to the actual value (actual molecular weight) of the number average molecular weight (M _n ) calculated by the ¹ H-NMR measurement, it is calculated from the terminal functional group portion of the polymerization initiator and the monomer / polymerization initiator molar ratio. The calculated molecular weight (design molecular weight) was obtained, and it was confirmed whether the molecular weight was obtained as designed.
(C) Molecular weight distribution (M _w / M _n )
In the following gel permeation chromatograph (GPC apparatus), N, N-dimethylformamide (DMF, 0.01 mol / L lithium iodide added product) is used as the mobile phase, the column temperature is 40 ° C., and the liquid feeding speed is 1.0 mL. / Min and converted using standard polystyrene (M _n = 36900, 9610).
Apparatus: TOSOH HLC-8120 (DMF solvent), column: TSK-GEL GMH _xl x2 + G ₂₀₀₀ H _XL
(D) Infrared absorption spectrum device: Fourier transform infrared spectrophotometer FT / IR-460Puls (manufactured by JASCO Corporation)
Measuring method: KBr tablet method

Example 1
(1) Synthesis of monomer (N-methacryloyl-2-methylaziridine) In a 500 mL two-necked eggplant flask under a nitrogen atmosphere, 8.19 g (143 mmol) of propyleneimine (2-methylaziridine) and 14.7 g of triethylamine ( 145 mmol) was diluted with 120 mL of dehydrated ether, 20 mL of 14.8 g (142 mmol) of methacrylic acid chloride in dehydrated ether was added dropwise over 20 minutes in an ice bath, and the ice bath was removed after completion of the addition. Further, 100 mL of dehydrated ether was added, and the mixture was stirred at room temperature for 5 hours. The produced hydrochloride was separated by suction filtration and distilled under reduced pressure at a distillation temperature of 61 to 62 ° C. and a pressure of 14 mmHg. Further, in the presence of calcium hydride, distillation was performed under reduced pressure at a distillation temperature of 51 to 52 ° C. and a pressure of 9.0 mmHg, and 9.92 g of N-methacryloyl-2-methylaziridine (79.4 mmol, yield) 56%).

(2) Purification of monomer The obtained N-methacryloyl-2-methylaziridine fraction was distilled in a high vacuum line in the presence of calcium hydride, diluted with tetrahydrofuran, and then into an ampoule equipped with a break seal. Sealed. About the component of the last distillation obtained here, < ¹ > H-NMR and < ¹³ > C-NMR measurement were performed. FIG. 1 shows the measurement result of ¹ H-NMR, and FIG. 2 shows the measurement result of ¹³ C-NMR. ¹ H-NMR spectrum a attached to signal, b, c, etc. are those a of marked on the spectrum structure, b, c, etc. are assigned to given hydrogen atom, also ¹³ “A”, “b”, “c”, and the like attached to the C-NMR signal belong to the carbon atom to which “a”, “b”, “c”, etc. of the structural formula described in the spectrum are attached. From these ¹ H-NMR and ¹³ C-NMR measurement results, it was confirmed that the fraction was the target N-methacryloyl-2-methylaziridine. Further, it was confirmed by gas chromatography that the fraction was almost a single component.

(3) Polymerization of monomer The purified N-methacryloyl-2-methylaziridine obtained in the above (2) was polymerized by anionic polymerization by a break seal method at -78 ° C under a high vacuum of 10 ^-6 mmHg. Went for hours. An adduct of s-butyllithium / 1,1-diphenylethylene (sBuLi / Ph ₂ C═CH ₂ ) was used as the polymerization initiator, and tetrahydrofuran containing a small amount of cyclohexane was used as the solvent. Further, lithium chloride (LiCl) was added as a polymerization additive (hereinafter referred to as additive). The amounts of monomers, polymerization initiators and additives used are shown in Table 1. After conducting anionic polymerization for a predetermined time, the glass polymerization vessel was opened, and a small amount of isopropanol was added to terminate the polymerization. Furthermore, the obtained polymerization solution was poured into a large amount of n-hexane to precipitate a polymer. The precipitated polymer was filtered off and dried, and the yield was measured. Further, the dried polymer was redissolved in tetrahydrofuran and poured into a large amount of n-hexane to perform reprecipitation purification. Finally, after dissolving in benzene, freeze-drying was performed, and ¹ H-NMR and ¹³ C-NMR measurements were performed. Table 1 shows the measurement results of polymerization conditions and polymerization results, number average molecular weight (M _n ), and molecular weight distribution (M _w / M _n ). 3 shows the ¹ H-NMR of the purified polymer, FIG. 4 shows the ¹³ C-NMR, FIG. 5 shows the infrared absorption spectrum, and FIG. 6 shows the gel permeation chromatogram. In FIG. 3, “a”, “b”, “c”, etc. attached to the signal of the ¹ H-NMR spectrum are attributed to hydrogen atoms attached with the structural formulas “a”, “b”, “c”, etc. described in the spectrum, respectively. In FIG. 4, a, b, c, etc. attached to the signal of ¹³ C-NMR are the carbon atoms attached with the structural formulas a, b, c, etc. described in the spectrum, respectively. It is attributed.
The polymer purified from the NMR spectra shown in FIGS. 3 and 4 consisted of only a vinyl polymer, and it was confirmed that the aziridinyl group did not participate in anionic polymerization and remained quantitatively.
In the infrared absorption spectrum shown in FIG. 5, a signal attributed to C-N stretching vibration of an aziridinyl group observed around 1,123cm ^-1, C-H of an aziridinyl group observed around 2,987Cm ^-1 From the signal attributed to stretching vibration, it was confirmed that the obtained polymer contained an aziridinyl group. Further, from Table 1 and FIG. 6, it was confirmed that the obtained polymer had an extremely narrow molecular weight distribution, and the actually measured value and the design value of the number average molecular weight were close to each other.

Example 2
In the polymerization of the monomer (3) of Example 1, the amounts of the monomer, polymerization initiator and additive were changed as shown in Table 1, the polymerization temperature was −40 ° C., and the polymerization time was 5 hours. Anionic polymerization was carried out under the same polymerization conditions as in Example 1 except that. Table 1 shows the measurement results of the polymerization results, number average molecular weight (M _n ) and molecular weight distribution (M _w / M _n ).
The polymer obtained in the same manner as in Example 1 was purified, and ¹ H-NMR, ¹³ C-NMR and infrared absorption spectrum were measured. As a result, the purified polymer consisted only of a vinyl polymer, and the aziridinyl group was It was confirmed that it remained quantitatively without participating in anionic polymerization.

Example 3
In the polymerization of the monomer (3) in Example 1, the amounts of the monomer, polymerization initiator and additive were changed as shown in Table 1, the polymerization time was 15 hours, and diphenylmethyl potassium as the polymerization initiator. Anionic polymerization was carried out under the same polymerization conditions as in Example 1 except that (Ph ₂ CHK) was used and lithium chloride was not used. Table 1 shows the measurement results of the polymerization results, number average molecular weight (M _n ) and molecular weight distribution (M _w / M _n ).
The polymer obtained in the same manner as in Example 1 was purified, and ¹ H-NMR, ¹³ C-NMR and infrared absorption spectrum were measured. As a result, the purified polymer consisted only of a vinyl polymer, and the aziridinyl group was It was confirmed that it remained quantitatively without participating in anionic polymerization.

Comparative Example 1
In the polymerization of the monomer (3) in Example 1, the monomer was changed to N, N-dimethylmethacrylamide (purchased from a commercial product (manufactured by Tokyo Kasei Kogyo Co., Ltd.) in the same manner). Anionic polymerization was carried out under the same polymerization conditions as in Example 1 except that the amounts of the monomer, polymerization initiator and additive were changed as shown in Table 1. Table 1 shows the measurement results of the polymerization conditions and polymerization results, and the number average molecular weight (Mn) and molecular weight distribution (M _w / M _n ).

Comparative Example 2
In Comparative Example 1, the amounts of monomers, polymerization initiators and additives were changed as shown in Table 1, and anionic polymerization was carried out under the same polymerization conditions as in Comparative Example 1 except that the polymerization temperature was 0 ° C. It was. The polymerization conditions and polymerization results, and the measurement results of the number average molecular weight (M _n ) and molecular weight distribution (M _w / M _n ) are shown in Table 1.
In Comparative Examples 1 and 2, it was confirmed that N, N-dialkylmethacrylamide not ring-formed did not give a polymer by anionic polymerization.

Example 4 (Sequential addition polymerization of monomers)
Polymerization of the purified N-methacryloyl-2-methylaziridine obtained in (2) of Example 1 was carried out at −40 ° C. for 5 hours under high vacuum of 10 ⁻⁶ mmHg by anionic polymerization by the break seal method. . An adduct of s-butyllithium / 1,1-diphenylethylene was used as the polymerization initiator, and tetrahydrofuran containing a small amount of cyclohexane was used as the solvent. Further, lithium chloride was added as an additive to the polymerization system. The amounts of monomers, polymerization initiators and additives used are shown in Table 2. After anionic polymerization for 5 hours, the polymerization solution was cooled to −78 ° C., and 16% by volume of the polymerization solution was fractionated. The remaining polymerization solution was returned to −40 ° C., and purified N-methacryloyl-2-methylaziridine was added again to the polymerization system in a predetermined amount (4.66 mmol), and the reaction was carried out at −40 ° C. for 5 hours. Thereafter, the glass polymerization vessel was opened, and a small amount of isopropanol was added to each of the polymerized solution (prepolymer solution) and the polymerized solution (postpolymer solution) to which purified N-methacryloyl-2-methylaziridine was added again for polymerization. Stopped. The obtained polymerization solutions were each poured into a large amount of n-hexane to precipitate a polymer. The precipitated polymer was filtered off and dried, and the yield was measured. Further, the dried polymer was redissolved in tetrahydrofuran and poured into a large amount of n-hexane to perform reprecipitation purification. Finally, after dissolving in benzene, freeze-drying was performed, and ¹ H-NMR and ¹³ C-NMR measurements were performed. The polymerization conditions and polymerization results, the number average molecular weight (M _n ), and the measurement results of molecular weight distribution are shown in Table 2. ^{From the} measurement results of ¹ H-NMR, ¹³ C-NMR and infrared absorption spectrum, it was confirmed that both the prepolymer and the postpolymer consisted only of a vinyl polymer, and the aziridinyl group remained quantitatively. FIG. 7 shows a comparison of gel permeation chromatograms of the prepolymer and postpolymer obtained. It can be seen that the molecular weight increases while maintaining a narrow molecular weight distribution.

2 is a chart showing ¹ H-NMR measurement results of N-methacryloyl-2-methylaziridine obtained in Example 1 and (2). 3 is a chart showing ¹³ C-NMR measurement results of N-methacryloyl-2-methylaziridine obtained in Example 1 and (2). 2 is a chart showing ¹ H-NMR measurement results of poly N-methacryloyl-2-methylaziridine obtained in Example 1 and (3). 3 is a chart showing ¹³ C-NMR measurement results of poly N-methacryloyl-2-methylaziridine obtained in Example 1 and (3). It is a chart which shows the infrared absorption spectrum of poly N-methacryloyl-2-methylaziridine obtained in Example 1, (3). 2 is a gel permeation chromatogram of poly N-methacryloyl-2-methylaziridine obtained in Example 1 and (3). The comparison of the gel permeation chromatogram of the prepolymer and postpolymer obtained in Example 4 is shown. The dotted line is for the prepolymer and the solid line is for the postpolymer.

Claims (4)

It has a repeating unit represented by the following general formula (I), has a number average molecular weight (M _n ) of 3,000 to 1,000,000, and a molecular weight distribution (M _w / M _n , M _w is N-methacryloylaziridine-based polymer having a weight average molecular weight of 1.5 or less.

Wherein R _{1 to} R ₄ are each independently selected from a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group. And all of R _{1 to} R ₄ are not hydrogen atoms.) The N-methacryloylaziridine polymer according to claim 1, wherein the molecular weight distribution ( _Mw / _Mn ) is 1.2 or less. The method for producing an N-methacryloylaziridine polymer according to claim 1 or 2, wherein an addition polymerization of an N-methacryloylaziridine compound represented by the following general formula (II) is performed.

Wherein R _{1 to} R ₄ are each independently selected from a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group. And all of R _{1 to} R ₄ are not hydrogen atoms.)   The method for producing an N-methacryloylaziridine polymer according to claim 3, wherein the addition polymerization is anionic polymerization.

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