JPH10324714A - Lactone ring-containing polymer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the new subject polymer having excellent pH-response and useful for optical materials, detergent builders, medical and agricultural raw materials, cement admixtures, coatings, adhesives, coated paper-improving agents, separation films, catalyst carriers, etc. SOLUTION: This lactone ring-containing polymer contains a structural unit expressed by formula I R<1> is H or an organic residue, preferably H; R<2> is H, methyl, CHR<3> OH (R<3> is H or an organic reidue), preferably CH2 OH], e.g. a polymer containing a structural unit of formula II. The compound of the formula I is obtained by cyclizing a polycarboxylic acid containing a structural unit expressed by formula III [M<1> and M<2> are each a monovalent or divalent metal ion, ammonium or an organic amine; R<7> is H, methyl, CHR<8> OH (R<8> is H or an organic residue)] at 0-150 deg.C, preferably 20-80 deg.C by using an acid (preferably added so as to make pH of the treating solution <=3) such as hydrochloric acid, sulfuric acid, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel lactone ring-containing polymer and a method for producing the same. More specifically, the present invention relates to a lactone ring-containing polymer which can be suitably used for various applications utilizing pH responsiveness, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a polymer containing a lactone ring in the main chain, particularly a polymer containing a 6-membered lactone ring, for example, a compound represented by the general formula (3):

[0003]

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In the formula, R ⁴ represents a hydrogen atom, a methyl group, a phenyl group, or a methylol group, and contains a structural unit represented by the following formula (Macromole. Chem.) ., 149,51 (1971)) and general formula (4)

[0005]

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[0006] De-alcoholized cyclized products of poly α-hydroxyalkyl acrylates containing a structural unit represented by the following formula (J. Polym. Sci., A., 27, 3, 751 (1989)) and the like are known. .

[0007]

However, the above-mentioned conventional lactone ring-containing polymer, particularly the lactone ring-containing polymer represented by the general formula (4), does not exhibit pH responsiveness, but exhibits pH responsiveness. It cannot be used for the intended use.

Therefore, there is a need for a novel lactone ring-containing polymer which can be suitably used for applications utilizing pH responsiveness. The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a novel lactone ring-containing polymer that can be suitably used for applications utilizing pH responsiveness.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that polycarboxylic acids containing specific structural units are lactone-cyclized with an acid to improve pH responsiveness. The inventors have found that an excellent novel lactone ring-containing polymer can be obtained, and have completed the present invention.

That is, the lactone ring-containing polymer according to the first aspect of the present invention has the general formula (1)

[0011]

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(Wherein, R ¹ represents a hydrogen atom or an organic residue, and R ² represents a hydrogen atom, a methyl group or —CHR ³ OH
And R ³ represents a hydrogen atom or an organic residue).

According to a second aspect of the present invention, there is provided a lactone ring-containing polymer according to the ^{first aspect} , wherein R ¹ is a hydrogen atom and R ² is It is characterized by being a —CH ₂ OH group.

According to the above-mentioned structure, it is possible to provide a novel lactone ring-containing polymer which can be suitably used for various uses including use of pH responsiveness. The lactone ring-containing polymer has excellent pH responsiveness, for example, optical materials, detergent builders, raw materials for medicine and agriculture, cement admixtures, paints, adhesives, coated paper modifiers, separation membranes or catalyst carriers. And the like.

The method for producing a lactone ring-containing polymer according to the third aspect of the present invention has the following general formula (2):

[0016]

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(In the formula, R ³ represents a hydrogen atom or an organic residue, and M ¹ and M ² each independently represent a hydrogen atom, a monovalent metal ion, a divalent metal ion, an ammonium group or an organic amine group. , R ⁷ is a hydrogen atom, a methyl group or -C
An HR ⁸ OH group, and R ⁸ represents a hydrogen atom or an organic residue).
It is characterized by lactone cyclization with an acid.

According to a fourth aspect of the present invention, there is provided a method for producing a lactone ring-containing polymer, wherein the acid has a pH of 3 or less. It is characterized as follows.

According to the above-mentioned method, a polycarboxylic acid containing a structural unit represented by the above general formula (2) can be easily lactone-cyclized by treating it with an acid. , A novel lactone ring-containing polymer having excellent heat resistance can be efficiently produced. Therefore, the above method is suitably used as a method for producing a novel lactone ring-containing polymer. In the above production method, when the pH of the acid is 3 or less, a water-insoluble lactone ring-containing polymer is produced as the lactone ring-containing polymer,
Can be separated.

Hereinafter, the present invention will be described in detail. The lactone ring-containing polymer according to the present invention contains a structural unit represented by the general formula (1) in the main chain, a substituent represented by R ¹ is constituted by a hydrogen atom or an organic residue, and R ² is represented by R ² . The substituent shown is composed of a hydrogen atom, a methyl group or a —CHR ³ OH group, and the substituent represented by R ³ is composed of a hydrogen atom or an organic residue independently of R ¹ .

Of the substituents represented by R ¹ and R ³ ,
Examples of the organic residue include an alkyl group having 1 to 18 carbon atoms, an aryl group, and a heterocyclic group. More specifically, a methyl group, an ethyl group, an n-propyl group, i
so-propyl group, n-butyl group, sec-butyl group,
n-hexyl group, cyclohexyl group, n-octyl group,
C1-C1 such as 2-ethylhexyl group and lauryl group
An alkyl group containing 2 straight or branched chains; a phenyl group,
An unsubstituted or substituted aryl group having 6 to 12 carbon atoms, such as a toluyl group, a xylyl group, a naphthalene group, or a benzyl group;
Hydroxymethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 4-
Hydroxybutyl group, 6-hydroxyhexyl group and the like,
Examples thereof include a hydroxyalkyl group having 1 to 6 carbon atoms.

Among these compounds, compounds in which the substituent represented by R ¹ is a hydrogen atom and the substituent represented by R ² is a —CH ₂ OH group are particularly preferred.

The weight average molecular weight (Mw) of the lactone ring-containing polymer is not particularly limited.
In order to efficiently exhibit easy handling and pH responsiveness, it is preferably in the range of 500 to 1,000,000, more preferably in the range of 1,000 to 500,000, and more preferably in the range of 10,000 to 500,000. More preferably, it is in the range of 000 to 300,000.

Further, the content of the structural unit represented by the general formula (1) in the lactone ring-containing polymer is 1
It is preferably at least 0% by weight, more preferably at least 40% by weight. When the content of the structural unit represented by the general formula (1) is within the above range, a lactone ring-containing polymer having more excellent pH responsiveness can be obtained.

In the lactone ring-containing polymer according to the present invention, structural units other than the structural unit represented by the general formula (1) are not particularly limited.

The lactone ring-containing polymer according to the present invention can be easily obtained by subjecting a polycarboxylic acid containing a structural unit represented by the above general formula (2) to lactone cyclization with an acid.

In the present invention, the polycarboxylic acid used as a raw material of the lactone ring-containing polymer contains the structural unit represented by the general formula (2), and the substituent represented by R ³ is a hydrogen atom or an organic compound. M ¹ , M
^The substituents represented by ² each independently comprise a hydrogen atom, a monovalent metal ion, a divalent metal ion, an ammonium group or an organic amine group, and the substituent represented by R ⁷ is a hydrogen atom, a methyl group or -CHR ⁸ OH groups, R ⁸
Is a compound in which the substituent represented by is composed of a hydrogen atom or an organic residue.

Of the substituents represented by M ¹ and M ² ,
Specific examples of the monovalent metal ion include a lithium ion, a sodium ion, and a potassium ion. Specific examples of the divalent metal ion include a magnesium ion, a calcium ion, and a barium ion. Further, the organic amine group refers to a substituted amino group. Specifically, one hydrogen atom bonded to a nitrogen atom is removed from organic amines such as ethylenediamine, N-alkyl-substituted polyamine, polyethylene polyamine, and alkanolamine. Indicates a separated group.

Further, among the substituents represented by R ⁸ ,
Specific examples of the organic residue include the substituents exemplified as specific examples of the substituent represented by R ³ .

The above-mentioned polycarboxylic acids are represented, for example, by the general formula (5)

[0031]

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(Wherein R ³ and R ⁵ each independently represent a hydrogen atom or an organic residue), alone or in combination with the hydroxyl group-containing monomer. After copolymerization with a polymerizable monomer, the resulting (co) polymer is easily produced by hydrolysis with an alkaline substance.

In the present invention, the polymerization method of the monomer component containing the above-mentioned hydroxyl group-containing monomer is not particularly limited. For example, a polymerization method using a polymerization initiator such as a radical polymerization initiator; Radiation such as electron beams,
Conventionally known various methods such as a polymerization method of irradiating ultraviolet rays and a polymerization method by heating can be employed.

The hydroxyl group-containing monomer represented by the above general formula (5) can be prepared by a conventionally known method, for example, by using a corresponding vinyl compound and an aldehyde compound as catalysts to form a tertiary amine compound and water. It can be easily obtained by a method of reacting in the presence (JP-A-7-285906). In the general formula (5), the substituent represented by R ³ is the same as described above. The substituent represented by R ⁵ is a substituent derived from an aldehyde compound, and specifically represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group, or a heterocyclic group.

Examples of monomers copolymerizable with the above-mentioned hydroxyl group-containing monomer (hereinafter, referred to as other monomers) include:
General formula (6)

[0036]

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Wherein R ⁶ represents a hydrogen atom or an organic residue, and R ⁹ represents a hydrogen atom, a monovalent metal ion, a divalent metal ion, an ammonium group, an organic amine group, or an organic residue. And the compounds represented.

Among the substituents represented by R ⁹ , specific examples of the monovalent metal ion include a lithium ion, a sodium ion and a potassium ion. Also,
Specific examples of the divalent metal ion include a magnesium ion, a calcium ion, and a barium ion. Further, the organic amine group refers to a substituted amino group,
Specifically, it is a group in which one hydrogen atom bonded to a nitrogen atom is eliminated from organic amines such as ethylenediamine, N-alkyl-substituted polyamine, polyethylene polyamine, and alkanolamine.

Of the substituents represented by R ⁶ and R ⁹ , examples of the organic residue include those having 1 to 18 carbon atoms.
An alkyl group, an aryl group, or a heterocyclic group. More specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-
Butyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl, lauryl and other alkyl groups having a straight or branched chain having 1 to 12 carbon atoms; phenyl, toluyl, xylyl An unsubstituted or substituted aryl group having 6 to 12 carbon atoms, such as a naphthalene group or a benzyl group; a hydroxymethyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 4-hydroxybutyl group; Examples thereof include a hydroxyalkyl group having 1 to 6 carbon atoms such as a 6-hydroxyhexyl group.

Specific examples of the other monomers include maleic anhydride, maleic acid and salts thereof, maleic acid esters, fumaric esters, itaconic acids and salts thereof, itaconic esters, styrene, vinyl acetate, and the like. Examples include acrylonitrile, (meth) acrylamide, allyl alcohol, ethylene, propylene, and vinyl chloride, but are not particularly limited.

Examples of the polymerization initiator include peroxides such as benzoyl peroxide and tert-butyl peroxide;
Azo compounds such as azobisisobutyronitrile; and persulfates. Further, the amount of the polymerization initiator used, the reaction conditions for the polymerization reaction, and the like are not particularly limited.

As the above alkaline substance, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia or an aqueous solution thereof is used.

The lactone ring-containing polymer according to the present invention comprises:
It can be easily obtained by treating the above polycarboxylic acids with an acid. In order to treat the above-mentioned polycarboxylic acids with an acid, specifically, an acid may be added to the above-mentioned polycarboxylic acids, mixed, and heated if necessary. By treating a polycarboxylic acid having a structural unit represented by the general formula (2) with an acid, the polycarboxylic acid is lactone-cyclized to form a polylactone ring containing a lactone ring represented by the general formula (1). Coalescence can be obtained.

Specific examples of the acid used in the lactone cyclization treatment include mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid; and organic acids such as methanesulfonic acid, paratoluenesulfonic acid, and trifluoroacetic acid. Heteropolyacids such as phosphotungstic acid and phosphomolybdic acid; and the like. One of the above acids may be used alone, or two or more of them may be used as appropriate. Among the above acids, hydrochloric acid,
Sulfuric acid is particularly preferred.

The above-mentioned acid may be used as a solution dissolved in water or an inert organic solvent, may be used as a suspension suspended in water or an inert organic solvent, or may be used as it is. It may be used as a solid.

When an acid is added to the above polycarboxylic acids, it is preferable to make the above polycarboxylic acids into an aqueous solution (aqueous polycarboxylate solution) and to add the acid to the aqueous solution. The above treatment may be carried out uniformly or in a heterogeneous system containing an inert organic solvent insoluble in water, but it is more preferable to use a uniform aqueous system. Further, the acid may be added all at once or sequentially. The time required for mixing the polycarboxylic acid and the acid is not particularly limited.

The treatment temperature at the time of lactone cyclization by adding an acid to the above polycarboxylic acids is 0 ° C. to 150 ° C.
Is more preferable, and the range of 20 to 80 degreeC is more preferable. If the treatment temperature is lower than 0 ° C., the progress of the lactone cyclization reaction is slowed, and the lactone ring-containing polymer may not be obtained efficiently. On the other hand, if the treatment temperature is higher than 150 ° C., decarboxylation or the formation of a gelled product will occur as a side reaction, which is not preferable.

The amount of the acid to be added to the above-mentioned polycarboxylic acids is not particularly limited as long as the treating solution containing the polycarboxylic acids shows an acidity, and preferably the pH of the treating solution is 5 or less, more preferably 3 or less. Hereafter, it is desirable to add the acid so that it is preferably 2 or less. By adding an acid so that the treatment liquid containing the above polycarboxylic acid shows acidity, the polycarboxylic acid is lactone-cyclized, and the lactone ring-containing polymer according to the present invention can be obtained.

In this case, when the polycarboxylic acid is a polymer obtained by hydrolyzing a homopolymer of the hydroxyl group-containing monomer, the pH of the treatment solution containing the polycarboxylic acid becomes 3 or more. It is preferred to add an acid so that: By treating a polycarboxylic acid composed of a homopolymer of the hydroxyl group-containing monomer with an acid so as to have a pH of 3 or less, a water-insoluble lactone ring-containing polymer can be obtained as a precipitate. For example, as the above polycarboxylic acids, sodium poly (α-hydroxymethyl) acrylate as a homopolymer of the hydroxyl group-containing monomer is used, and a 1% aqueous sulfuric acid solution is added to a 1% aqueous solution (treatment liquid). Then, the lactone ring-containing polymer containing the structural unit represented by the general formula (1) is obtained as a white solid precipitate by preparing the treatment liquid so as to have a pH of 2.8 at 30 ° C. Can be An example of the above main reaction is as follows.

[0050]

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Therefore, the precipitate is filtered, and the filtrate is dried to obtain a lactone ring-containing polymer.
It can be obtained as a separated and purified product.

As described above, the lactone ring-containing polymer according to the present invention is a novel compound containing the structural unit represented by the general formula (1), and has a structure represented by the general formula (2). It can be easily obtained by subjecting a polycarboxylic acid containing a unit to lactone cyclization with an acid.

As described above, the lactone ring-containing polymer forms a lactone ring on the acidic side, and becomes sparingly soluble or insoluble in water. In addition, the lactone ring-containing polymer has excellent heat resistance because it forms a lactone ring. On the other hand, the lactone ring-containing polymer is easily ring-opened on the alkaline side and readily soluble in water.

As described above, the lactone ring-containing polymer of the present invention has excellent pH responsiveness and can be suitably used for various applications including applications utilizing pH responsiveness. In addition, the method for producing a lactone ring-containing polymer of the present invention can efficiently produce the novel lactone ring-containing polymer having excellent pH responsiveness. Therefore, the method for producing a lactone ring-containing polymer of the present invention is suitably used as a method for producing a novel lactone ring-containing polymer. The lactone ring-containing polymer can be suitably used, for example, for optical materials, detergent builders, raw materials for medicine and agriculture, cement admixtures, paints, adhesives, coated paper modifiers, separation membranes or catalyst carriers. .

[0055]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 130 g (1 mol) of ethyl α- (hydroxymethyl) acrylate as a hydroxyl group-containing monomer was placed in a 1000 ml four-necked flask equipped with a stirrer, a cooler, a nitrogen gas inlet tube and the like. And 300 ml of benzene as a solvent were charged, and ethyl α- (hydroxymethyl) acrylate was dissolved in the benzene to prepare a reaction solution.

Next, the above reaction solution was heated in an oil bath maintained at 65 ° C. while blowing nitrogen into the above four-necked flask. Thereafter, 1.3 g of azoisobutyronitrile (polymerization initiator) dissolved in a predetermined amount of benzene was added to the reaction solution to start a polymerization reaction.

Thirty minutes after the initiation of the polymerization reaction, it was confirmed that the reaction solution had increased viscosity. After stirring the reaction solution for 3 hours, it was cooled to terminate the polymerization reaction. Thereafter, 400 g of a 10% aqueous sodium hydroxide solution as an alkaline substance was added to the above reaction solution, followed by stirring to hydrolyze the ester portion of the obtained polymer. Next, benzene and by-produced ethanol were removed under reduced pressure to obtain an aqueous solution of sodium polyα- (hydroxymethyl) acrylate as an aqueous solution of a polycarboxylate. Weight average molecular weight (Mw) of sodium poly-α- (hydroxymethyl) acrylate in the aqueous solution measured by aqueous GPC (gel permeation chromatography)
Was 55,000 in terms of polyacrylic acid.

Next, the above-mentioned aqueous solution of sodium polyα- (hydroxymethyl) acrylate was gradually dropped into the aqueous hydrochloric acid solution while stirring 2000 ml of a 1N aqueous hydrochloric acid solution. As a result, a white solid was deposited. This white solid was filtered and dried to obtain a white powder in a yield of 78 g. The pH of the filtrate at this time was 2.

With respect to the white powder obtained as described above,
The substance was identified by elemental analysis and infrared absorption spectrum (IR) measurement. As a result, the above white powder is a lactone cyclized product of poly α- (hydroxymethyl) acrylic acid, that is, the general formula (7)

[0061]

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It was confirmed that the polymer was a novel lactone ring-containing polymer according to the present invention containing a structural unit represented by the following formula:

FIG. 1 shows the infrared absorption spectrum of the white powder.
Shown in The calculated values of the elemental analysis are as follows. Theoretical value C 47.06%, H 5.88%, O 47.06% Measured value C 47.32%, H 5.66%, O 47.02% [Example 2] In Example 1, α- N-butyl α- (hydroxymethyl) acrylate as a hydroxyl group-containing monomer in place of ethyl (hydroxymethyl) acrylate
The same reaction and operation as in Example 1 were carried out except for using 58 g (1 mol), to obtain a white powder in a yield of 75 g. The pH of the filtrate at this time was 2. The obtained white powder was subjected to elemental analysis and infrared absorption spectrum (I
The substance was identified by measuring R). As a result, the white powder was a lactone cyclized product of poly α- (hydroxymethyl) acrylic acid as in Example 1, that is,
It was confirmed that the polymer was a novel lactone ring-containing polymer according to the present invention containing the structural unit represented by the general formula (7).

Example 3 130 g (1 mol) of ethyl α- (hydroxymethyl) acrylate as a hydroxyl-containing monomer was placed in a 1000 ml four-necked flask equipped with a stirrer, a cooler, a nitrogen gas inlet tube and the like. And 21 g (0.2 mol) of methyl methacrylate as another monomer, and 300 ml of benzene as a solvent.
Ethyl (hydroxymethyl) acrylate and methyl methacrylate were dissolved to prepare a reaction solution.

Next, the above reaction solution was heated in an oil bath kept at 65 ° C. while blowing nitrogen into the above four-necked flask. Thereafter, 1.5 g of azoisobutyronitrile (polymerization initiator) dissolved in a predetermined amount of benzene was added to the reaction solution to start a polymerization reaction.

Thirty minutes after the initiation of the polymerization reaction, the reaction solution was confirmed to have increased viscosity. After the reaction solution was stirred for 5 hours, it was cooled to terminate the polymerization reaction. Thereafter, 480 g of a 10% aqueous sodium hydroxide solution as an alkaline substance was added to the above reaction solution, followed by stirring to hydrolyze the ester portion of the obtained polymer. Next, benzene and by-produced methanol and ethanol were removed under reduced pressure, and sodium polyα- (hydroxymethyl) acrylate as an aqueous solution of polycarboxylate was removed.
An aqueous solution of a sodium methacrylate copolymer was obtained. Water system G
The weight average molecular weight (Mw) of the sodium poly-α- (hydroxymethyl) acrylate / sodium methacrylate copolymer in the aqueous solution measured by PC was 150,000 in terms of polyacrylic acid.

Next, the above-mentioned aqueous solution of sodium polyα- (hydroxymethyl) acrylate / sodium methacrylate copolymer was gradually dropped into the aqueous hydrochloric acid solution while stirring 2000 ml of a 1N aqueous hydrochloric acid solution. As a result, a white solid was deposited and precipitated. After filtering this white solid,
Drying yielded 75 g of a white powder. The pH of the filtrate at this time was 2. The white powder obtained as described above was subjected to elemental analysis and infrared absorption spectrum (I
The substance was identified by measuring R). As a result, it was confirmed that the white powder was a lactone cyclized product of a poly-α- (hydroxymethyl) acrylic acid / methacrylic acid copolymer, that is, a novel lactone ring-containing polymer according to the present invention. In addition, the results of this example show that the lactone ring-containing polymer has PH responsiveness.

Example 4 In a 1000 ml four-necked flask equipped with a stirrer, a cooler, a nitrogen gas inlet tube and the like, 65 g (0.5 g) of ethyl α- (hydroxymethyl) acrylate as a hydroxyl group-containing monomer was added. Mol), 57 g (0.5 mol) of ethyl methacrylate as another monomer, and 250 ml of ethyl acetate as a solvent, and the ethyl acetate contains ethyl α- (hydroxymethyl) acrylate and ethyl methacrylate. Was dissolved to obtain a reaction solution.

Next, the above reaction solution was heated in an oil bath maintained at 65 ° C. while blowing nitrogen into the above four-necked flask. Thereafter, 2.3 g of azoisobutyronitrile (polymerization initiator) dissolved in a predetermined amount of ethyl acetate was added to the reaction solution to start a polymerization reaction.

After 30 minutes from the start of the polymerization reaction, it was confirmed that the reaction solution had increased viscosity. After the reaction solution was stirred for 5 hours, it was cooled to terminate the polymerization reaction. Thereafter, the solvent ethyl acetate was removed under reduced pressure by an evaporator,
A polymer as a reaction product was obtained. Next, 400 g of a 10% aqueous sodium hydroxide solution as an alkaline substance was added to the polymer, and the mixture was stirred to hydrolyze the ester portion of the polymer, and poly-α- (hydroxy) was used as a polycarboxylate aqueous solution. A methyl (sodium) acrylate / sodium methacrylate copolymer aqueous solution was obtained. Poly-α- in the aqueous solution measured by aqueous GPC
The weight average molecular weight (Mw) of the (hydroxymethyl) sodium acrylate / sodium methacrylate copolymer is
It was 350,000 in terms of polyacrylic acid.

Next, while stirring 2,000 ml of a 1N aqueous hydrochloric acid solution, the above aqueous solution of the sodium polyα- (hydroxymethyl) acrylate / sodium methacrylate copolymer was gradually dropped into the aqueous hydrochloric acid solution. As a result, a white solid was deposited. This white solid was filtered and dried to obtain a white powder in a yield of 80 g. The pH of the filtrate at this time was 2.

With respect to the white powder obtained as described above,
The substance was identified by elemental analysis and infrared absorption spectrum (IR) measurement. As a result, the white powder was a lactone cyclized product of a poly-α- (hydroxymethyl) acrylic acid / methacrylic acid copolymer, that is, the general formula (8)

[0073]

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It was confirmed that the polymer was a novel lactone ring-containing polymer according to the present invention containing a structural unit represented by the following formula:
In addition, the results of this example show that the lactone ring-containing polymer has PH responsiveness.

FIG. 2 shows the infrared absorption spectrum of the white powder.
Shown in The calculated values of the elemental analysis are as follows. Theoretical value C 55.81%, H 6.98%, O 37.21% Measured value C 56.15%, H 7.12%, O 36.73% [Example 5] Stirrer, cooler, nitrogen Ethyl α- (hydroxymethyl) acrylate 26 as a hydroxyl group-containing monomer was placed in a 1000 ml four-necked flask equipped with a gas introduction tube and the like.
g (0.2 mol), 26 g (0.3 mol) of methacrylic acid as another monomer, and 52 g (0.2 mol) of styrene.
5 mol) and 250 ml of ethyl acetate as a solvent, and ethyl α- (hydroxymethyl) acrylate, methacrylic acid and styrene were dissolved in the ethyl acetate to prepare a reaction solution.

Next, the above reaction solution was heated in an oil bath maintained at 65 ° C. while nitrogen was blown into the four-necked flask. Thereafter, 2.3 g of azoisobutyronitrile (polymerization initiator) dissolved in a predetermined amount of ethyl acetate was added to the reaction solution to start a polymerization reaction.

After 30 minutes from the start of the polymerization reaction, the increase in the viscosity of the reaction solution was confirmed. After the reaction solution was stirred for 5 hours, it was cooled to terminate the polymerization reaction. Thereafter, the solvent ethyl acetate was removed under reduced pressure by an evaporator,
A polymer as a reaction product was obtained. Next, 200 g of a 10% aqueous sodium hydroxide solution as an alkaline substance was added to the polymer and stirred to hydrolyze the ester portion of the polymer, and polyα- (hydroxy) was used as a polycarboxylate aqueous solution. An aqueous solution of sodium (methyl) acrylate / sodium methacrylate / styrene was obtained. Sodium poly-α- (hydroxymethyl) acrylate in the aqueous solution measured by aqueous GPC /
The weight average molecular weight (Mw) of the sodium methacrylate / styrene copolymer is 210,00 in terms of polyacrylic acid.
It was 0.

Next, the above-mentioned aqueous solution of sodium polyα- (hydroxymethyl) acrylate / sodium methacrylate / styrene copolymer was gradually dropped into the aqueous hydrochloric acid solution while stirring 2000 ml of a 1N aqueous hydrochloric acid solution. As a result, a white solid was deposited. The white solid was filtered and dried to obtain a white powder in a yield of 95 g. The pH of the filtrate at this time was 2. The substance was identified by performing elemental analysis and measuring an infrared absorption spectrum (IR) of the white powder obtained as described above.
As a result, it was confirmed that the white powder was a lactone cyclized product of a poly-α- (hydroxymethyl) acrylic acid / methacrylic acid / styrene copolymer, that is, a novel lactone ring-containing polymer according to the present invention. . In addition, the results of this example show that the lactone ring-containing polymer has PH responsiveness.

[0079]

As described above, the lactone ring-containing polymer of the present invention has the general formula (1)

[0080]

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(Wherein, R ¹ represents a hydrogen atom or an organic residue, and R ² represents a hydrogen atom, a methyl group or —CHR ³ OH
Represents a group, and R ³ represents a hydrogen atom or an organic residue).

As described above, in the lactone ring-containing polymer of the present invention, R ¹ is a hydrogen atom and R ² is —CH ₂ O
The configuration is an H group.

According to the above configuration, there is an effect that a novel lactone ring-containing polymer which can be suitably used for various uses including the use of pH responsiveness can be provided. The lactone ring-containing polymer has an excellent pH
It has responsiveness and can be suitably used for optical materials, detergent builders, raw materials for medicine and agriculture, cement admixtures, paints, adhesives, coated paper modifiers, separation membranes, catalyst carriers, and the like.

The process for producing a lactone ring-containing polymer of the present invention is carried out according to the general formula (2) as described above.

[0085]

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(In the formula, R ³ represents a hydrogen atom or an organic residue, and M ¹ and M ² each independently represent a hydrogen atom, a monovalent metal ion, a divalent metal ion, an ammonium group or an organic amine group. , R ⁷ is a hydrogen atom, a methyl group or -C
An HR ⁸ OH group, and R ⁸ represents a hydrogen atom or an organic residue).
The lactone is cyclized with an acid.

As described above, the method for producing a lactone ring-containing polymer of the present invention has a configuration in which the pH of the acid is 3 or less.

According to the above constitution, the lactone cyclization can be easily carried out by treating the polycarboxylic acid containing the structural unit represented by the above general formula (2) with an acid. The effect is that a novel lactone ring-containing polymer having excellent stiffness can be efficiently produced. Therefore, the above method is suitably used as a method for producing a novel lactone ring-containing polymer. Further, in the above production method, when the pH of the acid is 3 or less, a water-insoluble lactone ring-containing polymer can be produced and separated as the lactone ring-containing polymer. Play.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of a white powder obtained in one example of the present invention.

FIG. 2 is an infrared absorption spectrum of a white powder obtained in another example of the present invention.

Claims (4)

[Claims] 1. A compound of the general formula (1) (Wherein, R ¹ represents a hydrogen atom or an organic residue; R ² represents a hydrogen atom, a methyl group or a —CHR ³ OH group;
³ represents a hydrogen atom or an organic residue), which is a lactone ring-containing polymer. 2. The method according to claim 2, wherein R ¹ is a hydrogen atom and R ² is —CH
The lactone ring-containing polymer according to claim 1, which is a ₂ OH group. 3. A compound of the general formula (2) (Wherein, R ³ represents a hydrogen atom or an organic residue, and M ¹ ,
M ² each independently represent a hydrogen atom, a monovalent metal ion,
Represents a valent metal ion, an ammonium group or an organic amine group, R ⁷ represents a hydrogen atom, a methyl group or —CHR ⁸ OH group, and R ⁸ represents a hydrogen atom or an organic residue. A method for producing a lactone ring-containing polymer, comprising cyclizing a polycarboxylic acid with an acid. 4. The method for producing a lactone ring-containing polymer according to claim 3, wherein the acid has a pH of 3 or less.