JP6465634B2 - Polymer containing cyclic amide group - Google Patents

Description

The present invention relates to a polymer containing a cyclic amide group. More specifically, the present invention relates to a novel cyclic amide group-containing polymer excellent in color tone, heat yellowing resistance, and moisture resistance.

Vinylpyrrolidone-based polymers such as polyvinylpyrrolidone and vinylpyrrolidone copolymers, which are typical cyclic amide group-containing polymers, have advantages and benefits such as biocompatibility, safety, and hydrophilicity. It is widely used in various fields such as fiber modifiers, adhesives, paints, dispersants, dye solubilizers, inks and electronic parts.

However, the conventional vinylpyrrolidone-based polymers have the above-mentioned advantages and advantages, but have the disadvantage that only those having poor color tone and heat-resistant yellowing can be obtained. For this reason, conventional vinylpyrrolidone polymers are used in applications that require excellent color tone and heat yellowing resistance, such as paints, resin modifiers, inks, ink receiving layers, various surface treatment agents, various primers, and various binders. There was resistance to using.

Polyvinylpyrrolidone has a very high hygroscopicity, and thus has a drawback that it is sticky and difficult to handle when it is used as a film or sheet or in various coating agents.

Patent Document 1 describes a vinylpyrrolidone polymer having improved heat yellowing resistance by a polymerization method. Patent Documents 2 and 3 relate to a vinylpyrrolidone resin composition having improved moisture resistance. Have been described.

JP 2003-292537 A JP 2003-105159 A JP 2002-173666 A

As described above, various vinylpyrrolidone polymers have been studied. However, the color tone, heat yellowing resistance, and moisture resistance cannot be said to be sufficiently high, and there is room for improvement.
This invention is made | formed in view of the said present condition, and the subject which this invention tends to solve exists in providing the cyclic amide group containing polymer excellent in color tone, heat-resistant yellowing, and moisture resistance.

The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above-mentioned problems are solved by a cyclic amide group-containing polymer having a specific structure, and the present invention has been completed.

That is, the cyclic amide group-containing polymer of the present invention is a cyclic amide group-containing polymer having a structural unit represented by the following general formula (1).

In the general formula (1), n represents the number of 1 to 4, ^{R 1} represents a hydrogen atom, an organic group having 1 to 30 carbon atoms, a metal atom or an ammonium salt.

Since the present invention is a cyclic amide group-containing polymer excellent in color tone, heat yellowing resistance, and moisture resistance, optical materials, films, sheets, paints, fiber modifiers, resin modifiers, inks, ink receiving layers, various types It can be suitably used for a surface treatment agent, various primers, various binders and the like.

2 is a ¹ H-NMR chart of a composition of cyclic amide acrylate obtained in Synthesis Example 2. FIG. 6 is a ¹³ C-NMR chart of a composition of cyclic amide acrylate obtained in Synthesis Example 2. FIG. 1 is a ¹ H-NMR chart of a cyclic amide group-containing polymer obtained in Example 1. 2 is a ¹ H-NMR chart of a cyclic amide group-containing polymer obtained in Example 2. FIG. 2 is a ¹ H-NMR chart of a cyclic amide group-containing polymer obtained in Example 3. FIG.

The present invention is a polymer having a structural unit represented by the general formula (1).
The polymer has a plurality of structural units represented by the general formula (1), and n and R ¹ in the plurality of structural units may be the same or different.
The organic group having 1 to 30 carbon atoms in R ¹ is not particularly limited, but is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxyalkyl group having 1 to 30 carbon atoms, and a substituted group. Alternatively, an unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted organic amine salt having 1 to 20 carbon atoms, and the like can be given.
Here, the above “substituted or unsubstituted” means that the group may or may not have a substituent. Moreover, when it has a substituent, the number of carbons contained in the substituent is also included in the above carbon number.
R ¹ is preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxyalkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms. Group, metal atom, ammonium salt, substituted or unsubstituted organic amine salt having 1 to 20 carbon atoms.
From the viewpoint of improving the water solubility of the polymer, R ¹ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxyalkyl group having 1 to 12 carbon atoms, substituted or unsubstituted. It is more preferably a substituted aryl group having 6 to 12 carbon atoms, a metal atom, an ammonium salt, a substituted or unsubstituted organic amine salt having 1 to 12 carbon atoms, a hydrogen atom, a substituted or unsubstituted carbon atom having 1 to 1 carbon atoms. 10 alkyl groups, substituted or unsubstituted alkoxyalkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aryl groups having 6 to 10 carbon atoms, metal atoms, ammonium salts, substituted or unsubstituted 1 to 10 carbon atoms It is more preferable that the organic amine salt is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkoxyalkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted carbon number. 6 Are particularly preferably an aryl group of ˜8, a metal atom, an ammonium salt, a substituted or unsubstituted organic amine salt of 1 to 8 carbon atoms, a hydrogen atom, a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms, A substituted or unsubstituted alkoxyalkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group having 6 to 8 carbon atoms, a metal atom, an ammonium salt, a substituted or unsubstituted organic amine salt having 1 to 5 carbon atoms. More preferably it is. R ¹ is most preferably a hydrogen atom, a methyl group, an ethyl group, a butyl group, or a methoxyethyl group.

Examples of the “unsubstituted alkyl group” include a methyl group, an ethyl group, an n-butyl group, a cyclohexyl group, and an ethylhexyl group.
The “substituted alkyl group” refers to a group in which one or two or more hydrogen atoms of the alkyl group are substituted with a group other than the alkyl group. Examples of the group other than the alkyl group include an aryl group, a hydroxyl group, an alkoxy group, an amino group, an amide group, a sulfonic acid (salt) group, and a carboxylic acid (salt) group.

Examples of the “unsubstituted alkoxyalkyl group” include methoxyethyl group, ethoxymethyl group and the like.
The “substituted alkoxyalkyl group” refers to a group in which one or two or more hydrogen atoms of an alkoxyalkyl group are substituted with a group other than an alkoxyalkyl group. Examples of the group other than the alkoxyalkyl group include an aryl group, a hydroxyl group, an amino group, an amide group, a sulfonic acid (salt) group, and a carboxylic acid (salt) group.

Examples of the “unsubstituted aryl group” include a phenyl group, a biphenyl group, and a naphthyl group.
The “substituted aryl group” refers to a group in which one or more of the hydrogen atoms of the aryl group are substituted with a group other than the aryl group. Examples of the group other than the aryl group include an alkyl group, a hydroxyl group, an alkoxy group, an amino group, an amide group, a sulfonic acid (salt) group, and a carboxylic acid (salt) group.

Examples of the metal atom include alkali metals such as Li, Na, and K; alkaline earth metals such as Ca and Mg; and transition metals such as Al and Fe.
The metal atom is preferably Na.
Examples of the organic amine salt include alkanolamine salts such as monoethanolamine salts, diethanolamine salts, and propanolamine salts; alkylamine salts such as trimethylamine salts and triethylamine salts.
The organic amine salt is preferably a monoethanolamine salt.
N in the general formula (1) is preferably 2 to 3.

The cyclic amide group-containing polymer of the present invention may have other structural units other than the structural unit represented by the general formula (1).
The other structural unit is not particularly limited, but is a monomer other than the monomer represented by the general formula (2) described later, and is the same as the monomer represented by the general formula (2). It is preferably a structural unit derived from any polymerizable monomer. Specific examples of other monomers copolymerizable with the monomer represented by the general formula (2) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic. (Meth) acrylic acid esters having 1 to 20 carbon atoms such as butyl acid, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, and hydroxyethyl (meth) acrylate; C1-C20 (meth) acrylamide derivatives, such as N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide; dimethylaminoethyl (meth) acrylate, dimethyl Basic unsaturated monomers such as aminoethyl (meth) acrylamide, vinylpyridine, vinylimidazole and Salts or quaternized compounds; N-vinyl compounds such as N-vinylformamide, N-vinyloxazolidone, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, N-vinylacetamide; (Meth) acrylic acid, itaconic acid, maleic acid, fumaric acid and other C1-C20 carboxyl group-containing unsaturated monomers and salts thereof; maleic anhydride, itaconic anhydride and the like C1-20 Unsaturated anhydrides; vinyl acetates having 1 to 20 carbon atoms, such as vinyl acetate and vinyl propionate; vinyl ethylene carbonate and derivatives thereof; styrene and derivatives thereof; ethyl (meth) acrylate-2-sulfonate and Derivatives; vinyl sulfonic acid and its derivatives; methyl vinyl ether, ethyl vinyl Ether, and butyl vinyl ether having 1 to 20 carbon atoms, ethylene, propylene, octene, butadiene, etc., olefins having 1 to 20 carbon atoms; and the like.

When the cyclic amide group-containing polymer of the present invention is a copolymer having a structural unit represented by the general formula (1) and a structural unit other than the structural unit represented by the general formula (1), The content of the structural unit represented by the general formula (1) is preferably 5% by mass or more and 95% by mass or less with respect to 100% by mass of all the structural units in the cyclic amide group-containing polymer. More preferably, it is 20 mass% or more and 90 mass% or less. More preferably, it is 50 mass% or more and 80 mass% or less. When the content of the structural unit represented by the general formula (1) is 5% by mass or more, it is preferable because functions such as adsorptivity and hydrophilicity derived from the cyclic amide group can be more fully exhibited.
A homopolymer consisting only of the structural unit represented by the general formula (1) is also a preferred embodiment of the present invention.

When the cyclic amide group-containing polymer of the present invention is a copolymer having a structural unit represented by the general formula (1) and a structural unit other than the structural unit represented by the general formula (1), The content of the structural unit other than the structural unit represented by the general formula (1) is preferably 5 to 95% by mass with respect to 100% by mass of all the structural units of the cyclic amide group-containing polymer. More preferably, it is 10-80 mass%, More preferably, it is 20-50 mass%.

The weight average molecular weight of the cyclic amide group-containing polymer of the present invention is not particularly limited, but preferably the lower limit is 1,000 and the upper limit is 10,000,000. More preferably, the lower limit is 5,000 and the upper limit is 5,000,000.
When the weight average molecular weight is 1,000 or more, the cyclic amide group-containing polymer of the present invention is superior in strength and heat resistance. If the weight average molecular weight is 10,000,000 or less, the cyclic amide group-containing polymer of the present invention is more excellent in solubility in a solvent, and the viscosity of the polymer solution can be further reduced. It will be better.
The weight average molecular weight of the cyclic amide group-containing polymer can be measured by the method described in Examples described later.

The cyclic amide group-containing polymer according to the present invention can be obtained, for example, by polymerizing a monomer component containing a monomer represented by the following general formula (2).

In general formula (2), n represents the number of 1 to 4, ^{R 1} represents a hydrogen atom, an organic group having 1 to 30 carbon atoms, a metal atom or an ammonium salt.

Specific examples and preferred examples of the organic group having 1 to 30 carbon atoms, metal atom and ammonium salt are the same as those of the organic group having 1 to 30 carbon atoms, metal atom and ammonium salt in the general formula (1). Moreover, as said n, Preferably it is 2-3.

Specific examples of the compound represented by the general formula (2) include 2- (2-oxopyrrolidin-1-yl) acrylic acid, 2- (2-oxopyrrolidin-1-yl) methyl acrylate, 2- (2-oxopyrrolidin-1-yl) ethyl acrylate, 2- (2-oxopyrrolidin-1-yl) propyl acrylate, 2- (2-oxopyrrolidin-1-yl) butyl acrylate, 2- (2 -Oxopyrrolidin-1-yl) methoxyethyl acrylate, 2- (2-oxoazepan-1-yl) acrylic acid, methyl 2- (2-oxoazepan-1-yl) acrylate, 2- (2-oxoazepan-1 -Yl) ethyl acrylate, 2- (2-oxoazepan-1-yl) butyl acrylate and the like.
The monomer of the general formula (2) may be used alone or in combination of two or more.

Preferred specific examples of the compound represented by the general formula (2) include cyclic amide acrylates represented by the following general formula (3).

In the general formula (3), R ¹ represents a hydrogen atom, an organic group having 1 to 30 carbon atoms, a metal atom, or an ammonium salt.
The C1-C30 organic group, metal atom, and ammonium salt in R ¹ are the same as the specific examples and preferred examples given in General Formula (1).

The method for producing the cyclic amide acrylate is not particularly limited, and the cyclic amide acrylate is, for example, at least one compound selected from the group consisting of pyruvate, pyruvate, and pyruvate, and the following general formula (4): It can be produced by reacting the represented compound. The above production method tends to improve the polymerizability of the cyclic amide acrylate (decrease in residual monomer) by reducing impurities such as the formyl group-containing compound contained in the obtained cyclic amide acrylate. This is preferable.

In the said General formula (4), n represents the number of 1-4.

The monomer component is not particularly limited as long as it contains at least the monomer represented by the general formula (2). For example, the monomer represented by the general formula (2) is used alone. Or any other monomer other than the monomer represented by the general formula (2) that can be copolymerized with the monomer represented by the general formula (2). Good. In addition, when copolymerizing monomers other than the monomer represented by General formula (2), content of the monomer represented by General formula (2) in a monomer component is as follows. Although not particularly limited, for example, the content of the monomer represented by the general formula (2) in the monomer component is 5% by mass or more with respect to 100% by mass of the total monomer components. 95 mass% or less, preferably 20 mass% or more and 90 mass% or less, more preferably 50 mass% or more and 80 mass% or less.

Specific examples and preferred examples of monomers other than the monomer represented by the general formula (2) are as described above. These may use only 1 type and may mix 2 or more types and the monomer represented by General formula (2).
The content of the other monomer is not particularly limited, but is preferably 5 to 95% by mass, more preferably 10 to 80% by mass with respect to 100% by mass of all monomer components, Preferably it is 20-50 mass%.

It is also a preferred embodiment of the present invention that the cyclic amide group-containing polymer of the present invention is a homopolymer obtained by polymerizing only the monomer represented by the general formula (2). That is, in this case, the content of the monomer other than the monomer represented by the general formula (2) in the monomer component used for the production of the cyclic amide group-containing polymer is 0% by mass. .

The method of the polymerization reaction for obtaining the cyclic amide group-containing polymer according to the present invention is not particularly limited, and conventionally known methods such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, precipitation polymerization, etc. It can be done by the method. When conventional N-vinyl-2-pyrrolidone (NVP) is used as a monomer having a pyrrolidone group, it is difficult to polymerize by emulsion polymerization. Emulsion polymerization is also possible by using the monomer represented by (2).

The solvent used in the polymerization reaction is not particularly limited, and examples thereof include aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ethers such as tetrahydrofuran and dioxane. System solvents; and the like. These solvents may be used alone or in combination of two or more. In addition, water is preferable as a preferable polymerization solvent, but a solvent that dissolves in water, for example, an alcohol selected from methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, diethylene glycol, and the like, or two or more kinds of water is selected. It can also be used as a mixture. In particular, when a solvent such as isopropyl alcohol or n-butyl alcohol is mixed with water, the boiling point of water, that is, the polymerization temperature is lowered by azeotropic action, which is preferable from the viewpoint of suppressing side reactions.
When performing the polymerization reaction, the reaction conditions such as the reaction temperature are not particularly limited. For example, the reaction temperature is preferably 20 to 150 ° C.

The polymerization initiator is not particularly limited. For example, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl Organic peroxides such as carbonate and t-amylperoxy-2-ethylhexanoate; hydrogen peroxide; persulfates such as potassium persulfate and ammonium persulfate; 2,2′-azobis (isobutyronitrile); And azo compounds such as 1,1′-azobis (cyclohexanecarbonitrile) and 2,2′-azobis (2,4-dimethylvaleronitrile); These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator used may be set as appropriate according to the combination of the polymerizable monomers and the reaction conditions, and is not particularly limited.
The amount of the initiator used is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and 0.5 to 3% by mass with respect to the polymerizable monomer component. % Is even more preferred.

When the polymerization reaction is performed, a conventionally known transition metal salt can be used for the purpose of promoting the polymerization reaction. Specific examples of the transition metal salt include carboxylates and chlorides such as copper, iron, cobalt, and nickel. These may be used alone or in combination of two or more. May be. When the transition metal salt is used, the amount used is not particularly limited, but is preferably 0.1 to 20000 ppb, more preferably 1 to 5000 ppb in terms of mass ratio with respect to the polymerizable monomer component. When performing the polymerization reaction, in addition to the polymerization initiator and, if necessary, the pH adjuster and the transition metal salt, any chain transfer agent, buffering agent, etc. can be used as necessary. .

In the cyclic amide group-containing polymer according to the present invention, the content of a formyl group-containing compound such as formaldehyde as an impurity is preferably 0.1% by mass or less with respect to 100% by mass of the polymer, and 0.01% by mass. More preferably, it is% or less. Further, the content of the compound represented by the general formula (4) as an impurity is preferably 0.001 ppm or more and 50000 ppm or less with respect to 100% by mass of the polymer, and is 0.01 ppm or more and 5000 ppm or less. More preferably. In the cyclic amide group-containing polymer (composition) according to the present invention, the content of the monomer represented by the general formula (2) is 100% by mass with respect to the cyclic amide group-containing polymer according to the present invention. It is preferable that it is 10,000 ppm or less. The lower limit of the content is, for example, 0.01 ppm.

As described above, the cyclic amide group-containing polymer according to the present invention has excellent color tone, heat-resistant yellowing, and moisture resistance, so that it is an optical material, film, sheet, paint, fiber modifier, resin. It can be used in various applications such as modifiers, inks, ink receiving layers, various surface treatment agents, various primers, various binders, and the like.
[Example]

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not restrict | limited at all by these Examples. Unless otherwise specified, “parts” hereinafter represents “parts by mass”.

<Quantification of compounds>
The compositions obtained in the following synthesis examples were quantified using a calibration curve prepared in advance by gas chromatography (hereinafter “GC”) under the following conditions.

(GC condition)
Measuring device: GC-2014 (trade name) manufactured by SHIMADZU
Capillary column: InertCap Pure-Wax (trade name) length 30 m × inner diameter 0.25 mm, film thickness 0.25 μm

⁽¹ H-NMR and ¹³ C-NMR measurement conditions)
Samples were dissolved in deuterated chloroform and evaluated by ¹ HNMR and ¹³ CNMR.
Measurement conditions for ¹ H-NMR:
Measuring device: “Unity Plus” 400 MHz manufactured by Varian
¹ H-NMR (single pulse), pulse angle 45 °, pulse repetition time 3 seconds, integration 16 times.
Pulse Sequence: s2pul
Ambient temperature
Acq. time 4.000 sec
Width 8000.0 Hz
OBSERVE H1,399.6055323 MHz
DATA PROCESSING
FT size 65536
Total time 1 min, 52 sec

¹³ CNMR measurement conditions:
Measuring device: “Unity Plus” 400 MHz manufactured by Varian
¹³ CNMR (single pulse), pulse angle 45 °, pulse repetition time 0.939 seconds, number of integration 128 times.
Pulse Sequence: s2pul
Ambient temperature
Acq. time 1.061 sec
Width 30165.9 Hz
OBSERVE C13,100.4808268 MHz
DECOUPLE H1,399.6073706 MHz
Power 39 dB
continuously on
WALTZ-16 modulated
DATA PROCESSING
Line broadcasting 1.0 Hz
FT size 65536
Total time 558 hr, 34 min, 6 sec

<Measurement of weight average molecular weight / dispersion degree of polymer>
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined by gel permeation chromatography (GPC) under the following conditions. The degree of dispersion is weight average molecular weight / number average molecular weight, and was calculated from the weight average molecular weight and the number average molecular weight.
System: GPC system HLC-8220 manufactured by Tosoh Corporation
Developing solvent: Chloroform (made by Wako Pure Chemical Industries, special grade), flow rate: 0.6 ml / min Standard sample: TSK standard polystyrene (manufactured by Tosoh Corporation, PS-oligomer kit)
Measurement side column configuration: guard column (manufactured by Tosoh Corp., TSKguardcolumn SuperHZ-L), separation column (manufactured by Tosoh Corp., TSKgel SuperHZM-M) 2 series connection reference side column configuration: reference column (manufactured by Tosoh Corp., TSKgel SuperH-RC) )

(Evaluation method for coating film appearance and heat-resistant yellowing)
Dissolve the polymer in chloroform to make a 10% solution, apply it on a glass plate using an applicator, form a film at room temperature, and then dry it with a hot air dryer at 80 ° C. for 20 minutes. did. Then, it heat-processed for 20 minutes with a 200 degreeC hot-air dryer, and visually observed the external appearance change of the coating film.

(Method of evaluating moisture resistance)
1 g of the polymer powder was spread on an aluminum cup having a diameter of 5 cm and allowed to stand for 24 hours at 23 ° C. and 50% RH, and the state of the polymer powder was confirmed visually and by touch.

(Synthesis Example 1)
In a 2 L four-necked flask equipped with a thermometer, a condenser, a stirrer, and Dean Stark, 307 parts by mass of methyl pyruvate, 171 parts by mass of 2-pyrrolidone, 1040 parts by mass of toluene, 0.3 part by mass of methoquinone as a polymerization inhibitor, 4-hydroxy-2,2,6,6, -tetramethylpiperidine 1-oxyl (4H-TEMPO) 0.6 parts by mass, p-toluenesulfonic acid monohydrate 3.8 parts by mass as a catalyst was added and stirred. The mixture was heated until the internal temperature reached 114 ° C. and reacted for 20 hours while distilling off water under reflux. After the reaction, toluene was distilled off with an evaporator, followed by distillation purification to obtain 203 parts by mass of methyl 2- (2-oxopyrrolidin-1-yl) acrylate (PyAM). When the obtained PyAM was analyzed by gas chromatography, the PyAM concentration was 99.5% by mass, and 3000 ppm of 2-pyrrolidone was contained. In addition, the compound which has a formyl group was not detected (it was 0 ppm).

(Synthesis Example 2)
In a 500 mL four-necked flask equipped with a thermometer, condenser, stirrer, and Dean Stark, 26.6 parts by mass of pyruvic acid, 30.4 parts by mass of methoxyethanol, 80 parts by mass of benzene, and p-toluenesulfonic acid monohydrate as a catalyst 1.1 parts by mass of the Japanese product was added, and the mixture was heated to a bath temperature of 95 ° C. and an internal temperature of 78 ° C. with stirring, and reacted for 4 hours while distilling off water under reflux. After the reaction, it was washed with water, and then toluene was distilled off with an evaporator, followed by distillation purification to obtain 36.4 parts by mass of methoxyethyl pyruvate.
Next, 29.3 parts by mass of methoxyethyl pyruvate, 17.1 parts by mass of 2-pyrrolidone, 120 parts by mass of toluene, polymerization inhibitor, 300 mL four-necked flask equipped with a thermometer, a condenser, a stirrer, and Dean Stark As a catalyst, 0.050 part by mass of methoquinone, 0.050 part by mass of 4H-TEMPO and 0.6 part by mass of p-toluenesulfonic acid monohydrate as a catalyst are added, and the bath temperature is 132 ° C. and the internal temperature is 114 ° C. while stirring. Until the reaction was continued for 18 hours while distilling off water. After the reaction, toluene was distilled off with an evaporator, followed by purification by column chromatography to obtain 20.8 parts by mass of methoxyethyl 2- (2-oxopyrrolidin-1-yl) acrylate (PyAME). When the obtained PyAME was analyzed by gas chromatography, the PyAME concentration was 99.6% by mass, and 1000 ppm of 2-pyrrolidone was contained. ¹ H-NMR and ¹³ C-NMR of the obtained methoxyethyl 2- (2-oxopyrrolidin-1-yl) acrylate are shown in FIGS. In addition, the compound which has a formyl group was not detected (it was 0 ppm).

Example 1
A reactor equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction tube was charged with 10 parts by mass of PyAM obtained in Synthesis Example 1 and 5 parts by mass of ion-exchanged water, and 75 ° C. while passing nitrogen through the reactor. The temperature was raised to. As a polymerization initiator, 0.02 part by mass of VA057 (manufactured by Wako Pure Chemical Industries, Ltd.) was added three times every 3 hours, and polymerization was carried out for 9 hours. The obtained polymer solution was reprecipitated with acetone and dried under reduced pressure to obtain a white polymer (polymer (1)). The weight average molecular weight (in terms of standard polystyrene) of the polymer (1) was 18,000.
The ¹ H-NMR of polymer (1) is shown in FIG.
The polymer (1) was evaluated for coating film appearance, heat yellowing resistance, and moisture resistance by the above methods. The evaluation results are summarized in Table 1.

(Example 2)
A reactor equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introduction pipe was charged with 6 parts by mass of PyAM obtained in Synthesis Example 1, 4 parts by mass of styrene, and 10 parts by mass of 1,4-dioxane. The temperature was raised to 100 ° C. while introducing nitrogen, and 0.02 part by mass of Luperox 575 (manufactured by Arkema Yoshitsugu) was added three times every 3 hours as a polymerization initiator, and polymerization was carried out for 9 hours. The obtained polymer solution was reprecipitated with hexane and dried under reduced pressure to obtain a white polymer (polymer (2)). The weight average molecular weight (standard polystyrene conversion) of the polymer (2) was 88,000. FIG. 4 shows ¹ H-NMR of the polymer (2).
The polymer (2) was evaluated for coating film appearance, heat yellowing resistance, and moisture resistance by the above methods. The evaluation results are summarized in Table 1.

(Example 3)
A reactor equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction tube was charged with 10 parts by mass of PyAME obtained in Synthesis Example 2 and 10 parts by mass of ion-exchanged water, and nitrogen was passed through the reactor to 75 ° C. The temperature was raised. As a polymerization initiator, 0.05 part by mass of VA057 (manufactured by Wako Pure Chemical Industries, Ltd.) was added three times every 3 hours, and polymerization was performed for 9 hours. The solvent water was distilled off using an evaporator, diluted with acetone and reprecipitated with diisopropyl ether. The obtained polymer was dried at 100 ° C. to obtain a white polymer (polymer (3)). The weight average molecular weight (standard polystyrene conversion) of the polymer (3) was 10,700. The ¹ H-NMR of the polymer (3) is shown in FIG.
The polymer (3) was evaluated for coating film appearance, heat yellowing resistance, and moisture resistance by the above methods. The evaluation results are summarized in Table 1.

(Comparative Example 1)
About the homopolymer (commercial item, PVP K-30) of N-vinylpyrrolidone, the coating film appearance, heat yellowing resistance, and moisture resistance were evaluated by the above methods. The evaluation results are summarized in Table 1.

(Comparative Example 2)
A white polymer (comparative polymer (2)) was obtained in the same manner as in Example 2 except that PyAM was changed to N-vinylpyrrolidone (NVP). The weight average molecular weight (in terms of standard polystyrene) of the comparative polymer (2) was 27,000. The evaluation results are summarized in Table 1.

As described above, the cyclic amide group-containing polymer of the present invention is compared with an N-vinylpyrrolidone-based polymer, which is a conventional typical cyclic amide group-containing polymer, and the appearance of the coating film, heat yellowing resistance, and moisture resistance. It is clear that this is excellent.

Claims (2)

A structural unit represented by the following general formula (1) possess a ratio of more than 5% by weight relative to the total structural units 100 wt%, weight average molecular weight of the 1,000 to 10,000,000 der Rukoto A cyclic amide group-containing polymer.

In the general formula (1), n represents the number of 1 to 4, ^{R 1} represents an organic group of a hydrogen atom or 1 to 30 carbon atoms. The cyclic amide group-containing polymer according to claim 1, wherein the cyclic amide group-containing polymer has a formyl group-containing compound content of 0.1% by mass or less with respect to 100% by mass of the polymer. Coalescence.

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