JP2003274986A - Method for decomposing unsaturated carboxylic acid- based copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for decomposing an unsaturated carboxylic acid-based copolymer without having bad influence on natural environments. <P>SOLUTION: The method for decomposing the unsaturated carboxylic acid- based copolymer comprises bringing a white decay fungus or an external secretase of the white decay fungus into an unsaturated carboxylic acid-based copolymer in which a functional group having a property generating a radical is bound to the molecular chain of the unsaturated carboxylic acid-based copolymer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for decomposing an unsaturated carboxylic acid copolymer. More specifically, it relates to a method for decomposing an unsaturated carboxylic acid-based copolymer at the time of its disposal, without adversely affecting the natural environment.

[0002]

2. Description of the Related Art Unsaturated carboxylic acid polymers such as acrylic acid polymers and their cross-linked products are used as additives to detergent builders and mud compositions for ground excavation, water retention agents for soil, and water absorption such as disposable diapers. It is used in a wide range of fields such as flexible materials.
And, the builder for detergent is used as an auxiliary component of the surfactant in order to enhance the cleaning ability of the synthetic detergent for textiles. This detergent builder has initially used sodium carbonate, sodium silicate, sodium borate, etc., but if hard water is used as washing water, an insoluble precipitate consisting of a surfactant metal salt is produced, so hard water is used. Sodium tripolyphosphate, which does not produce a precipitate when used, has come to be used. However, this sodium tripolyphosphate has a problem of causing eutrophication of lakes and rivers. Therefore, A-type zeolite, which has less adverse effect on the natural environment, is used. However,
Since the A-type zeolite has insufficient performance as a builder, an acrylic acid-based polymer is used to supplement the performance.

Additives to muddy water compositions for ground excavation absorb frictional heat generated during ground excavation, carry out excavation debris from the bottom of the pit to the ground, maintain the pit wall or form a collapsible formation. It is used as an additive component to muddy water compositions injected into excavation sites to prevent collapse. In addition, it is used as a soil water retention agent to support the growth of planted plants to green dry soil. Further, in the fields of livestock industry and agriculture, unsaturated carboxylic acid-based polymers are used as flocculants for solid-liquid separation of livestock excreta, and unsaturated carboxylic acid-based polymers are used as fermentation aids for compost. Coalescent cross-links have been used.

In the disposal of materials made of unsaturated carboxylic acid polymers and their crosslinked materials, which have been used in each of these fields, they are sprayed on the field after composting. ing. However, this unsaturated carboxylic acid polymer and its cross-linked product have a problem that they remain in the natural environment as they are because they are not biodegradable. Further, the paper diaper is incinerated, but in this case, there is a problem that the incinerated ash exhibits alkalinity and damages the incinerator.

Therefore, a proposal has been made to make the unsaturated carboxylic acid polymer exhibit biodegradability. For example, a method of increasing the molecular weight of an acrylic acid oligomer by an ester bond or an amide bond, and a method of graft-polymerizing a biodegradable polymer such as a saccharide or polyvinyl alcohol have been proposed. Further, a method using polyaspartic acid has been proposed. However, all of these methods have drawbacks such as insufficient performance as a builder for detergents and complicated manufacturing steps.

Further, as the water-absorbent resin having biodegradability, starch-based water-absorbent resin, hyaluronic acid-based water-absorbent resin, polyglutamic acid-based water-absorbent resin (JP-A-6-322).
No. 358, No. 7-300563, and No. 10-251402) are proposed.
These water-absorbent resins are inferior in water absorbency as compared with acrylic acid polymer-based water-absorbent resins, and have the drawback that the manufacturing process is complicated.

Under these circumstances, an unsaturated carboxylic acid polymer such as an acrylic acid polymer having excellent performance as a water-absorbent resin or a builder for detergents and which is easy to manufacture is used at the time of disposal after use. Therefore, it is desired to develop a method for treating by a biodegradation method that does not have a bad influence on the natural environment.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for decomposing an unsaturated carboxylic acid type copolymer which does not adversely affect the natural environment at the time of disposal.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a white-rot fungus or an extracellular secretory enzyme of the white-rot fungus has an unsaturated carvone having a specific chemical structure. It was found that the acid copolymer has the ability to decompose, and the present invention has been completed based on such findings.

That is, the gist of the present invention is as follows. (1) The following general formula [1]

[0011]

[Chemical 8]

[In the formula [1], R ¹ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkali metal atom or an ammonium group, and Y represents a hydrogen atom, a methyl group or-.
Indicates COOX. ] The repeating unit (1) represented by the following general formula [2]

[0013]

[Chemical 9]

[0014] [In the formula (2), R ¹ and Y have the same meaning as R ¹ and Y in the general formula (1), Z ¹
Represents a functional group having a property of generating a radical. ] The unsaturated carboxylic acid type | system | group characterized by contacting the unsaturated carboxylic acid type copolymer which has the repeating unit represented by Decomposition method of copolymer. (2) The functional group represented by Z ¹ in the general formula [2] is
The following general formulas [3] to [22]

[0015]

[Chemical 10]

[0016]

[Chemical 11]

Ar in the formulas [3] to [22] represents an aromatic hydrocarbon group having 6 to 14 carbon atoms, and R ² is 1 to 1 carbon atom.
10 hydrocarbon groups, amino groups, -COOX (provided that X
Represents a hydrogen atom, an alkali metal atom or an ammonium group. ), —SO ₃ X (where X represents a hydrogen atom, an alkali metal atom or an ammonium group), —CHO.
Or indicates -NO _2, R ³ represents a hydrogen atom, an alkali metal atom or a hydrocarbon group having 1 to 8 carbon atoms, R ⁴ represents a divalent hydrocarbon group having 1 to 10 carbon atoms, R ⁵ is Represents a hydrogen atom, a methyl group or an ethyl group, and R ⁶ has 1 to 1 carbon
10 hydrocarbon groups are shown. Further, m is an integer of 0 to 5, n
Is an integer of 0 to 5 and (m + n) is an integer of 1 to 5. ] The decomposition method of the unsaturated carboxylic acid type copolymer as described in said (1) which is a functional group selected from the group represented by these. (3) The unsaturated carboxylic acid copolymer has the following general formula [23]

[0018]

[Chemical 12]

[X in the formula represents a hydrogen atom, an alkali metal atom or an ammonium group. ] The repeating unit (1) represented by the following general formula [24]

[0020]

[Chemical 13]

[Z ² in the formula represents a 4-hydroxyphenylamide group, an amide group or an aldehyde group. ] Or the following general formula [25]

[0022]

[Chemical 14]

[In the formula, X represents a hydrogen atom, an alkali metal atom or an ammonium group, and Z ³ represents a 4-aminophenylamide group. ] The method for decomposing an unsaturated carboxylic acid-based copolymer as described in (1) or (2) above, which is an unsaturated carboxylic acid-based copolymer comprising a repeating unit (2) represented by (4) The crosslinked product of the unsaturated carboxylic acid copolymer is obtained by reacting the unsaturated carboxylic acid copolymer with a water-soluble compound having two or more functional groups capable of reacting with a carboxyl group in one molecule. The method for decomposing an unsaturated carboxylic acid-based copolymer according to any one of (1) to (3), which is a cross-linked product obtained by (5) The crosslinked product of the unsaturated carboxylic acid copolymer is a crosslinked product obtained by reacting a compound having two or more unsaturated groups in one molecule during the polymerization of the unsaturated carboxylic acid. The method for decomposing an unsaturated carboxylic acid copolymer according to any one of (1) to (3). (6) White rot fungus is a funerorokite (Phaner
Ochaete genus, Pleurotus
s) genus, Trametes genus, Ceriporiopsis genus, Lentinula genus, Coriolas (Cori)
genus olus, Berookande
Ra) and Pycnoporus
The method for decomposing an unsaturated carboxylic acid-based copolymer according to any one of (1) to (5) above, which is one or more kinds of bacteria selected from bacteria belonging to the genus. (7) White rot fungus is Phanerochaete chrysossp
The method for decomposing an unsaturated carboxylic acid copolymer according to any one of (1) to (6) above, which is an (orium) bacterium.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an unsaturated carboxylic acid system having a repeating unit (1) represented by the general formula [1] and a repeating unit (2) represented by the general formula [2]. A method for decomposing an unsaturated carboxylic acid copolymer, which comprises contacting a white rot fungus or an extracorporeal secretory enzyme of a white rot fungus with the copolymer or a crosslinked product thereof.

Examples of the alkali metal atom represented by X in the above general formula [1] include a lithium atom, a sodium atom and a potassium atom. Further, the general formula [3] to the functional group Z ¹ in the general formula [2]
Examples of the aromatic hydrocarbon group having 6 to 14 carbon atoms represented by Ar in [22] include a phenylene group, a biphenylene group,
Examples thereof include naphthylene group and anthrylene group. In addition, as the hydrocarbon group having 1 to 10 carbon atoms represented by R ² in the formula, a methyl group, an ethyl group, an n-propyl group,
i-propyl group, n-butyl group, i-butyl group, sec
-Butyl group, tert-butyl group, n-pentyl group, n
-Hexyl group, n-heptyl group, n-octyl group, n-
Nonyl group, n-decyl group, phenyl group, tolyl group, xylyl group, benzyl group, cyclopentyl group, cyclohexyl group and the like can be mentioned. The hydrocarbon group having 1 to 8 carbon atoms represented by R ³ in the formula is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group. Group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, phenyl group, tolyl group, xylyl group, benzyl group, cyclopentyl group, cyclohexyl group and the like. Further, the divalent hydrocarbon group having 1 to 10 carbon atoms represented by R ⁴ in the formula is a methylene group, an ethylene group, a trimethylene group, a tetramethylene group,
Examples thereof include a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group and a phenylene group. In addition, examples of the hydrocarbon group having 1 to 10 carbon atoms represented by R ⁶ in the formula include the same groups as the hydrocarbon group having 1 to 10 carbon atoms represented by R ² .

As the unsaturated carboxylic acid type copolymer which can be decomposed by the method of the present invention, those produced by various methods can be used. For example,
The following general formula [26]

[0027]

[Chemical 15]

[0028] [R ^1, X, Y in the formula [26] has the general formula in (1) R ^1, X, Y the same meaning as. ]
And one or more unsaturated compounds represented by the following general formula [27]

[0029]

[Chemical 16]

[0030] [R ^1, Y, Z ¹ in the formula [27] has R ^1, Y, the same meaning as Z ¹ in the general formula (2). ] The copolymer obtained by copolymerizing 1 type (s) or 2 or more types of the unsaturated compound represented by these. here,
As the unsaturated compound represented by the above general formula [26],
Examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, maleic anhydride and the like. Further, alkali metal salts or ammonium salts of these unsaturated carboxylic acids are used. And these unsaturated compounds are
They may be used alone or in any combination of two or more.

The unsaturated compound represented by the above general formula [27] is, for example, 3-carboxy-N- (4
-Aminophenyl) -acrylamide, 3-carboxy-N- (3-aminophenyl) -acrylamide, 3-
Carboxy-N- (2-aminophenyl) -acrylamide, 3-carboxy-N- (4-hydroxyphenyl) -acrylamide, 3-carboxy-N- (3-hydroxyphenyl) -acrylamide, 3-carboxy-N- ( 2-hydroxyphenyl) -acrylamide,
Acrolein, methacrolein, crotonaldehyde,
2-methyl-2-butenal, ethylene sulfide, allyl mercaptan, allyl cyanide, allyl amine, acrylonitrile, acrylamide, methacrylonitrile, methacrylamide, acrylic acid hydrazide, 4-
Examples thereof include (phenylazo) benzyl acrylate and alkali metal salts and ammonium salts thereof.

Further, one or more unsaturated compounds represented by the above general formula [26] and the following general formula [28]

[0033]

[Chemical 17]

[In the formula [28], R ¹ , Ar, R ³ , m,
n is R ¹ , Ar in the general formulas [3] to [8],
It has the same meaning as R ³ , m and n. ] The copolymer obtained by copolymerizing 1 type (s) or 2 or more types of the aromatic compound represented by these. Here, examples of the aromatic compound represented by the general formula [28] include hydroquinone, resorcinol, p-methoxyphenol, and 1,5.
-Dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxyanthraquinone, dihydroxybenzoic acid, dihydroxybenzaldehyde, 1.4-benzoquinone, dihydroxybenzenesulfonic acid, dihydroxybenzonitrile, dihydroxynitrobenzene, p
-Aminophenol, m-aminophenol, o-aminophenol, p-diaminobenzene, m-diaminobenzene, o-diaminobenzene, 2,5-dimethoxyaniline, 2,3-dimethoxyaniline, 2,4-dimethoxyaniline, 3,4-dimethoxyaniline, 3,5-
Dimethoxyaniline, 2,5-dihydroxyaniline,
2,3-dihydroxyaniline, 2,4-dihydroxyaniline, 3,4-dihydroxyaniline, 3,5-dihydroxyaniline, p-hydroxyaminophenol, m-hydroxyaminophenol, o-hydroxyaminophenol, 3-amino- 4-hydroxybenzenesulfonic acid, 2-aminophenyl-4-sulfonic acid,
5-amino-2-hydroxybenzene sulfonic acid etc. are mentioned.

Thus, in addition to the copolymer obtained by copolymerizing the unsaturated compound represented by the above general formula [26] and the unsaturated compound represented by the above general formula [27], the above general formula A copolymer obtained by introducing into a homopolymer of an unsaturated compound represented by [26] a compound having a functional group such as a hydroxyl group or an amino group at a carboxyl group in the polymer by a condensation reaction. It may be a polymer.

The unsaturated carboxylic acid copolymer has the repeating unit (1) represented by the above general formula [1].
And a repeating unit (2) represented by the general formula [2]. Regarding the content ratio of the repeating unit (1) and the repeating unit (2), the latter is 0.5 mol% or more. It is preferable to use one. This is because the copolymer having a content of the repeating unit (2) of less than 0.5 mol% may lower the biodegradability.

The unsaturated carboxylic acid copolymer used in the present invention is an unsaturated carboxylic acid copolymer composed of the basic structural unit composed of the repeating unit (1) and the repeating unit (2). , Other repeating units, eg
A repeating unit derived from one or more compounds such as acrylic acid esters such as vinyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, and methacrylic acid esters such as methyl methacrylate and ethyl methacrylate. It may be contained. The content of the repeating units other than the repeating units (1) and (2) is preferably within 30 mol% so that the hydrophilicity of the unsaturated carboxylic acid copolymer is not lowered.

Among the unsaturated carboxylic acid copolymers having various structural units used in the present invention, the repeating unit (1) has the chemical structure represented by the above general formula [23], and The repeating unit (2) is represented by the general formula [2
Those having a chemical structure represented by 4] or [25] are preferable because the raw materials are easily available and the manufacturing cost can be suppressed low.

Next, crosslinking of the unsaturated carboxylic acid type copolymer having the repeating unit (1) represented by the general formula [1] and the repeating unit (2) represented by the general formula [2]. As the body, a cross-linked product obtained by reacting the above-mentioned unsaturated carboxylic acid-based copolymer with a water-soluble compound having two or more functional groups capable of reacting with a carboxyl group in one molecule can be used. . Examples of the compound having such a chemical structure include ethylene glycol diglycidyl ether, glycerol triglycidyl ether, polyethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, diethylene glycol,
Examples include triethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, ethylenediamine, butanediamine, diethanolamine, triethanolamine, polyoxypropylene, polyvinyl alcohol, pentaerythritol, sorbit, sorbitan, glucose, mannitol, and mannitan. . Further, a cross-linked product obtained by reacting a compound having two or more unsaturated groups in one molecule during the above-mentioned unsaturated carboxylic acid polymerization can also be used. Examples of such compounds include N, N-methylenebisacrylamide, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, and the like.

The unsaturated carboxylic acid copolymer and its crosslinked product which can be decomposed by the method of the present invention are:
As a repeating unit constituting these, the above-mentioned general formula [1]
And the functional group represented by Z ¹ in the general formula [2], in particular, the functional group represented by Z ¹ has a property of generating a radical by an exocrine enzyme of the white rot fungus, When it is brought into contact with the extracorporeal secretory enzyme, the decomposition proceeds due to molecular cleavage associated with radical generation. This extracorporeal secretory enzyme of white rot fungus directly acts on the unsaturated carboxylic acid copolymer and its crosslinked product when the live bacterium of white rot fungus is brought into contact with it. Can be made. When the enzyme secreted by the white-rot fungus is used, an extracorporeal secreted enzyme obtained by separating the culture solution of the white-rot fungus with an ion exchange resin or the like can be used.

As the white-rot fungus, various white-rot fungi can be used.
Erochaete, Pleurotas (Pleuro)
genus tus, genus Trametes, genus Ceriporiopsis, genus Lentinula, genus Coriolus
genus riolus, Jerokandera (Bjerokan)
dera) and Pycnoporu
s) One or more kinds of white rot fungi selected from the white rot fungi belonging to the genus are preferably used. Among these white-rot fungi, Phanerochaete chrysospo (Phanerochaete chrysospo)
White rot fungus of the species Rium) is particularly preferably used. After collecting these white-rot fungi from soil and decay wood,
A culture obtained by culturing using a commonly used medium such as malt agar medium is preferably used. In this case, the culture conditions may be adjusted such that the culture temperature is 25 to 35 ° C and the pH of the culture solution is 4.5 to 5.5.

Then, the white rot fungus or the extracorporeal enzyme of the white rot fungus is used to bring it into contact with an unsaturated carboxylic acid copolymer or a crosslinked product thereof which is subjected to disposal after use in various fields of use. In decomposing, a culture solution of white-rot fungus or a solution containing the extracorporeal enzyme of white-rot fungus,
The unsaturated carboxylic acid copolymer or a crosslinked product thereof may be attached to the molded article, or the unsaturated carboxylic acid copolymer or a crosslinked product thereof may be present in compost or soil in which white-rot fungi are present. It may be a method of burying.

[0043]

[Example 1]

(1) Production of unsaturated carboxylic acid copolymer Capacity 100 equipped with stirrer, thermocouple and oil-water separator
Into a milliliter separable flask, 5 g of polyacrylic acid having a weight average molecular weight of 75,000, 1.52 g of P-aminophenol, and 20 ml of N-methylpyrrolidone as a solvent were added and stirred. Then, this flask was immersed in an oil bath maintained at 160 ° C., and after the temperature in the reaction system became constant, sulfuric acid 10 m
g and 50 ml of toluene as a solvent,
Reacted for hours.

After the reaction was completed, 50 ml of water was added,
The pH was adjusted to 7 with sodium hydroxide and reprecipitation purification was performed with acetone. And the unsaturated carboxylic acid copolymer was obtained by freeze-drying the obtained product. About the unsaturated carboxylic acid copolymer obtained here, gel permeation chromatography (GP
The weight average molecular weight measured by the C) method is 82,000.
Met. In addition, ¹ H-NMR measurement [manufactured by JEOL Ltd .;
GX-270 apparatus], it was confirmed that this unsaturated carboxylic acid copolymer was composed of the following repeating units.

[0045]

[Chemical 18]

(2) As a degrading culture solution of an unsaturated carboxylic acid copolymer by a white-rot fungus, a medium component having a medium composition shown in Table 1 was added to a sodium tartrate buffer solution having a concentration of 20 mmol.
A culture solution which was dissolved in 0 ml and adjusted to pH 4.5 was used.

[0047]

[Table 1]

To 100 ml of this culture solution, 10 mg of the unsaturated carboxylic acid copolymer obtained in (1) above was added, and to this was precultured Phanerochaete chrysosporium fungus body fluid 5 Add 1 ml at 30 ° C, 150 rpm
The culture was shaken for a week. After the culture was completed, the culture solution was sterilized by an autoclave by removing the bacterial cells with a glass fiber filter paper. Next, the degradation rate of this unsaturated carboxylic acid copolymer was measured by the GPC method after freeze-drying the filtered culture solution and adjusting the concentration. The measurement results are shown in Table 2 and FIG.

[Comparative Example 1] The same procedure as in Example 1 was carried out except that polyacrylic acid was used as the unsaturated carboxylic acid polymer instead of the unsaturated carboxylic acid copolymer used in Example 1. The results are shown in Table 2 and FIG.

[0050]

[Table 2]

Example 2 (1) Production of Unsaturated Carboxylic Acid Copolymer Capacity 100 equipped with stirrer, thermocouple and reflux condenser
In a milliliter separable flask, add acrylic acid 6.
48 g, acrolein 0.62 g and water 63.9 g
Was added and the mixture was stirred to be uniform. Then, this flask was immersed in an oil bath maintained at 60 ° C., and after the temperature in the reaction system became constant, 2,2 ′ was used as a polymerization initiator.
-Azobis (2-amidinopropane) dihydrochloride 0.81
g was added and the polymerization reaction was carried out for 2 hours.

After completion of the reaction, the reaction solution was adjusted to pH 7 and the product was reprecipitated and purified with acetone. And the unsaturated carboxylic acid copolymer was obtained by freeze-drying the obtained product. The weight average molecular weight of the unsaturated carboxylic acid copolymer obtained here was 361,000. From the ¹ H-NMR measurement result, it was confirmed that this unsaturated carboxylic acid copolymer was composed of the following repeating units.

[0053]

[Chemical 19]

(2) Decomposition of unsaturated carboxylic acid copolymer with manganese peroxidase 10 m of unsaturated carboxylic acid copolymer obtained in the above (1)
g was added to 100 ml of the reaction solution having the composition shown in Table 3, and the mixture was shaken at 30 ° C. and 150 rpm for 24 hours. With respect to the unsaturated carboxylic acid copolymer after this treatment, the weight average molecular weight was measured to confirm the presence or absence of decomposition thereof. The results are shown in Table 4.

[0055]

[Table 3]

Example 3 (1) Production of unsaturated carboxylic acid copolymer Unsaturation was carried out in the same manner as in (1) of Example 1 except that the amount of P-aminophenol added was 0.61 g. A carboxylic acid copolymer was obtained. The weight average molecular weight of the unsaturated carboxylic acid copolymer obtained here was 80,000. From the ¹ H-NMR measurement result, it was confirmed that this unsaturated carboxylic acid copolymer was composed of the following repeating units.

[0057]

[Chemical 20]

(2) Decomposition of unsaturated carboxylic acid copolymer with manganese peroxidase The unsaturated carboxylic acid copolymer obtained in (1) above was treated with manganese peroxidase in the same manner as in Example 2 (2). It was disassembled. The results are shown in Table 4.

Example 4 (1) Production of 3-carboxy-N- (4-aminophenyl) acrylamide In a eggplant-shaped flask having an internal volume of 1 liter, 10.9 g of 4-diaminobenzene was placed, and 550 ml of acetone was further added. Was added and dissolved. Then, a solution prepared by dissolving 9.8 g of maleic anhydride in 50 ml of acetone was slowly added thereto and reacted at 20 ° C. for 14 hours. After completion of the reaction, the precipitate was filtered, washed and dried under reduced pressure to obtain 3-carboxy-N- (4-aminophenyl) acrylamide (yield 60%).

(2) Production of unsaturated carboxylic acid copolymer In a separable flask having a capacity of 100 ml equipped with a stirrer, a thermocouple, a reflux condenser and a chemical pump for supplying raw materials, 7.2 g of acrylic acid and water were added. After adding 4.0 g of sodium oxide, 3.0 g of 3-carboxy-N- (4-aminophenyl) acrylamide, 11.4 g of water and 7.8 mg of ferric chloride tetrahydrate as a catalyst, 100 ° C.
Soaked in an oil bath held by. Then, 2.8 g of hydrogen peroxide solution having a concentration of 60% by mass was dropped into this flask by a chemical pump over 4 hours, and the reaction was further performed for 1 hour. After completion of the reaction, the product was purified by reprecipitation with acetone. And the unsaturated carboxylic acid copolymer was obtained by freeze-drying the obtained product. The weight average molecular weight of the unsaturated carboxylic acid copolymer obtained here was 8
It was 1,000. From the ¹ H-NMR measurement result, it was confirmed that this unsaturated carboxylic acid copolymer was composed of the following repeating units.

[0061]

[Chemical 21]

(3) Degradation of unsaturated carboxylic acid copolymer with manganese peroxidase The unsaturated carboxylic acid copolymer obtained in (2) above was treated with manganese peroxidase in the same manner as in (2) of Example 2. It was disassembled. The results are shown in Table 4.

Comparative Example 2 The procedure of Example 2 was repeated, except that polyacrylic acid was used as the unsaturated carboxylic acid polymer instead of the unsaturated carboxylic acid copolymer used in Example 1. The results are shown in Table 4.

[0064]

[Table 4]

Example 5 (1) Production of unsaturated carboxylic acid copolymer Polyacrylic acid 5 having a weight average molecular weight of 1,700,000
g, P-aminophenol 0.76 g and N-methylpyrrolidone 60 ml as a solvent, and the reaction time was 7 hours, and the same procedure as in (1) of Example 1 was carried out. The weight average molecular weight of the obtained unsaturated carboxylic acid copolymer was 2,918,000. Also, ¹ H-N
From the MR measurement results, it was confirmed that this unsaturated carboxylic acid copolymer was composed of the following repeating units.

[0066]

[Chemical formula 22]

(2) Production of crosslinked unsaturated carboxylic acid copolymer In a separable flask having an internal volume of 100 ml, 5.0 g of the unsaturated carboxylic acid copolymer obtained in the above (1)
Then, 25 mg of ethylene glycol diglycidyl ether as a cross-linking agent and 20 ml of water were added and uniformly dissolved, and then immersed in an oil bath kept at 70 ° C. and reacted for 2 hours. After the reaction was completed, the obtained product was freeze-dried to obtain a crosslinked product of an unsaturated carboxylic acid copolymer.

(3) Decomposition of cross-linked unsaturated carboxylic acid copolymer with manganese peroxidase 50 mg of the cross-linked unsaturated carboxylic acid copolymer obtained in the above (2) was used in the same manner as in Example 2. Add to 100 ml of the reaction solution having the composition shown in the table and
It was shaken at 50 rpm for 24 hours. The product obtained was then filtered through a glass filter, washed and dried. Then, the mass of the crosslinked product of the unsaturated carboxylic acid copolymer remaining on the glass filter was measured, and the recovery rate of the crosslinked product not decomposed by the manganese peroxidase was calculated. The results are shown in Table 6.

Comparative Example 3 50 mg of the crosslinked product of the unsaturated carboxylic acid copolymer obtained in (2) of Example 5 was added to 100 ml of a reaction solution containing no manganese peroxidase having the composition shown in Table 5. At 30 ° C, 1
It was shaken at 50 rpm for 24 hours.

The product obtained is then analyzed in Example 5.
The recovery rate of the crosslinked product was calculated in the same manner as in (3). The results are shown in Table 6.

[0071]

[Table 5]

[0072]

[Table 6]

Example 6 (1) Production of Unsaturated Carboxylic Acid Copolymer Capacity 100 equipped with stirrer, thermocouple and reflux condenser
Acrylic acid 1 in a milliliter separable flask
1.52 g, acrolein 2.24 g and sodium hydroxide 5.1 g were added, and water was further added to adjust the concentration of the solute to 20% by mass, and then stirred so that the solution became uniform. Then, this flask was immersed in an oil bath maintained at 50 ° C., and after the temperature in the reaction system became constant, 2,2′-azobis (2-amidinopropane) dihydrochloride 1. 62 g was added and the polymerization reaction was carried out for 3 hours. After completion of the reaction, the reaction solution was purified by dialysis. And the unsaturated carboxylic acid copolymer was obtained by freeze-drying the obtained product. The weight average molecular weight of the unsaturated carboxylic acid copolymer obtained here was 110,000. Further, from the ¹ H-NMR measurement result, it was confirmed that the content ratio of the structural unit derived from acrolein in the unsaturated carboxylic acid copolymer was 7.7 mol%.

(2) Decomposition of unsaturated carboxylic acid copolymer by white rot fungus The unsaturated carboxylic acid copolymer obtained in (1) above was decomposed in the same manner as in (2) of Example 1. It was FIG. 3 shows the measurement results of the decomposition rate of this unsaturated carboxylic acid copolymer by the GPC method. The decomposition rate was 69%.

Example 7 An acrylic acid-acrylamide copolymer [Aldr was used as the unsaturated carboxylic acid copolymer.
manufactured by ich: content of acrylamide unit: 18.8 mol%; weight average molecular weight: 1,268,000] was used in the same manner as in (2) of Example 1 to perform the decomposition.

The results of measurement of the decomposition rate of this unsaturated carboxylic acid copolymer by the GPC method are shown in FIG. Decomposition rate is 1
It was 8%.

[0077]

According to the present invention, the unsaturated carboxylic acid copolymer can be decomposed without adversely affecting the natural environment.

[Brief description of drawings]

FIG. 1 is a chart of the measurement results of an unsaturated carboxylic acid copolymer before and after decomposition in Example 1 by a GPC method.

FIG. 2 is a chart of measurement results of polyacrylic acid before and after decomposition in Comparative Example 1 by a GPC method.

FIG. 1 is a chart of the measurement results of an unsaturated carboxylic acid copolymer before and after decomposition in Example 6 by a GPC method.

FIG. 2 shows acrylic acid before and after decomposition in Example 7.
It is a chart of the measurement result of the acrylamide copolymer by the GPC method.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI theme code (reference) (C12N 1/14 C12R 1: 645 C12R 1: 645) F term (reference) 4B064 AD57 AE02 BH20 CA05 CA21 CB11 CB30 CC03 CD05 CD12 CD20 DA16 4B065 AA71X AC15 BB40 BD44 CA55 4F301 AA20 CA09 CA23 4J200 AA08 BA05 BA19 EA11

Claims (7)

[Claims] 1. The following general formula [1]: [In the formula [1], R ¹ represents a hydrogen atom or a methyl group,
X represents a hydrogen atom, an alkali metal atom or an ammonium group, and Y represents a hydrogen atom, a methyl group or -COOX. ] The repeating unit (1) represented by the following general formula [2] [In the formula (2), R ¹ and Y have the meanings formula in (1) the same as R ¹ and Y, Z ¹ represents a functional group having the property of generating radicals. ] The unsaturated carboxylic acid type | system | group characterized by contacting the unsaturated carboxylic acid type copolymer which has the repeating unit represented by Decomposition method of copolymer. 2. The functional group represented by Z ¹ in the general formula [2] is represented by the following general formulas [3] to [22]: [Chemical 4] [Ar in the formulas [3] to [22] represents an aromatic hydrocarbon group having 6 to 14 carbon atoms, and R ² represents a hydrocarbon group having 1 to 10 carbon atoms, an amino group, -COOX (provided that X is Is a hydrogen atom,
Indicates an alkali metal atom or ammonium group. ),-
SO ₃ X (provided that, X is a hydrogen atom, an alkali metal atom or an ammonium group.), - CHO, or -NO
₂ , R ³ represents a hydrogen atom, an alkali metal atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ⁴ represents 1 to 10 carbon atoms.
Is a divalent hydrocarbon group, R ⁵ is a hydrogen atom, a methyl group or an ethyl group, and R ⁶ is a hydrocarbon group having 1 to 10 carbon atoms. Further, m is an integer of 0 to 5, n is an integer of 0 to 5, and (m + n) is an integer of 1 to 5. ] The decomposition method of the unsaturated carboxylic acid type copolymer of Claim 1 which is a functional group selected from the group represented by these. 3. The unsaturated carboxylic acid-based copolymer has the following general formula [23]: [X in the Formula represents a hydrogen atom, an alkali metal atom or an ammonium group. ] The repeating unit (1) represented by
The following general formula [24]: [Z ² in the formula represents a 4-hydroxyphenylamide group, an amide group or an aldehyde group. ] Or the following general formula [25] [In the formula, X represents a hydrogen atom, an alkali metal atom or an ammonium group, and Z ³ represents a 4-aminophenylamide group. ] The unsaturated carboxylic acid type copolymer of Claim 1 or 2 which is an unsaturated carboxylic acid type copolymer which consists of the repeating unit (2) represented by these. 4. A cross-linked product of an unsaturated carboxylic acid-based copolymer, wherein the unsaturated carboxylic acid-based copolymer contains a water-soluble compound having two or more functional groups capable of reacting with a carboxyl group in one molecule. It is a cross-linked product obtained by reaction, and
5. The method for decomposing an unsaturated carboxylic acid copolymer according to any one of 1. 5. A crosslinked product of an unsaturated carboxylic acid copolymer is a crosslinked product obtained by reacting a compound having two or more unsaturated groups in one molecule during polymerization of an unsaturated carboxylic acid. The method for decomposing an unsaturated carboxylic acid copolymer according to any one of claims 1 to 3. 6. The white rot fungus is funeroquite (Pha
genus nerochaete, Pleurotas (Pleur
genus otus, genus Trametes, genus Ceriporiopsis, genus Lentinula, genus Coriolus (C)
Oriolus, Beroker
genus Ndera and Pycnopor
The method for decomposing an unsaturated carboxylic acid copolymer according to any one of claims 1 to 5, which is one kind or two or more kinds of bacteria selected from the genus us). 7. The white rot fungus is Phanerochaete chrysporium.
The method for decomposing an unsaturated carboxylic acid copolymer according to any one of claims 1 to 6, which is a bacterium (Osporium).