JPH10279602A - Production of polycarboxylic acid derived from polysaccharide comprising structural units of anhydrous glucose or salt thereof and detergent composition containing the acid or salt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a polycarboxylic acid made from a polysaccharide comprising structural units of anhydrous glucose and having excellent biodegradability and having a high carboxyl content and a high molecular weight or a salt thereof and to provide a detergent composition containing the acid or the salt. SOLUTION: This process consists of subjecting an aqueous liquid containing a polysaccharide comprising structural units of anhydrous glucose, a transition metal or a transition metal compound and a metal halide to electrolysis to form a polycarboxylic acid which consumes at least 435 mg or above (in terms of the weight of sodium hydroxide) of an alkali, per g of the polycarboxylic acid, when neutralized by titration and has a weight-average molecular weight of 5,000 or above or a salt thereof. The detergent composition comprises the polycarboxylic acid or a salt thereof obtained by the above process and a surfactant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polycarboxylic acid or a salt thereof from a polysaccharide having anhydrous glucose as a constituent unit, and a detergent composition containing the same.

[0002]

2. Description of the Related Art Polycarboxylic acids such as polyacrylic acid and copolymers of acrylic acid and maleic acid are used as dispersants, chelating agents or flocculants. And
When these polycarboxylic acids are used as chelating agents, their effects are affected by the content and molecular weight of the carboxyl group, and the larger the carboxyl group content and the larger the molecular weight, the better the effect is generally exhibited. Is known. When the chelating ability of these polycarboxylic acids was measured by the method described in Examples described later, polyacrylic acid had a chelating ability of about 300 mg / g with respect to Ca ions, and acrylic acid and maleic acid. The copolymer with the acid shows a chelating ability of approximately 370 mg / g. However, polycarboxylic acid obtained by polymerizing a monomer having a vinyl group, such as polyacrylic acid or a copolymer of acrylic acid and maleic acid, is extremely difficult to biodegrade by microorganisms. It is well known that they have problems. Therefore, there has been an attempt to obtain a polycarboxylic acid or a salt thereof which is expected to be biodegraded by oxidizing a polysaccharide which is a natural polymer, aiming at a chelating agent useful for a detergent builder or the like. I have.

Japanese Patent Publication No. 49-1281 discloses a two-stage oxidation method using periodic acid and chlorite or a one-stage oxidation method using hypochlorite to obtain polycarboxylic acid from various polysaccharides. Is disclosed. However, the amount of carboxyl groups in the polycarboxylic acid obtained by the method disclosed in this publication does not exceed two on average per monosaccharide unit, except for special cases. As a special case where the content of carboxyl groups exceeds 2 per monosaccharide unit, Example 78 describes the pre-production of monocarboxylated corn starch, which is further oxidized, and Examples 79 and 80 thereof. Discloses an example using sodium alginate as a polysaccharide. However, in these examples, there is no description about the molecular weight of the obtained polycarboxylic acid, and it does not suggest a polycarboxylic acid having a structure in which both the content and the molecular weight of the carboxyl group are clearly defined. In the production methods described in these examples, a large amount of acetic acid is used when oxidizing the formed dialdehyde derivative to dicarboxylic acid with sodium chlorite. Is well known to undergo hydrolysis, resulting in a significant decrease in molecular weight. In addition, this method has a problem that the production process is complicated because the monocarboxylated starch is once produced and then further subjected to an oxidation reaction. On the other hand, when alginic acid is used as a raw material, it is economical. There is a problem in terms. In addition, when hypochlorite is used, there is a problem that a large amount of salt is produced as a by-product in the product, and cost is required to remove the salt.

JP-A-60-226502 discloses a method of oxidizing a polysaccharide to obtain a polycarboxylic acid by using hypochlorite as an oxidizing agent and controlling reaction conditions. I have. Although the polycarboxylic acid obtained by this method has a sufficiently high molecular weight, the content ratio of carboxyl units is at most 81%, and the average content of carboxyl groups per monosaccharide unit is less than 2, and It is not a polycarboxylic acid having a structure that satisfies both the group content and the molecular weight simultaneously.

Japanese Patent Application Laid-Open No. 62-247837 discloses P
A method of oxidizing a polysaccharide to obtain a polycarboxylic acid by using a metal catalyst such as d and a promoter such as Bi in combination has been disclosed. This method oxidizes the reducing end of the polysaccharide. Again, the carboxyl group content does not exceed two on average per monosaccharide unit.

Japanese Patent Application Laid-Open No. 4-175301 discloses a method for oxidizing a polysaccharide in the presence of hypobromite or hypoiodite. Although no data suggesting the structure of the product polycarboxylic acid is disclosed in this publication, the term “dicarboxy polysaccharide or polycarboxy saccharide” is used in most cases in the specification. It is understood that the C ₂ -C ₃ diol functionality represents a polysaccharide which has been converted into two carboxyl groups with ring opening, respectively, "and is included in the polycarboxylic acids of this publication. It is believed that the amount of carboxyl groups is a maximum of two per monosaccharide unit on average.

JP-A-4-233901 discloses a method of oxidizing an enzyme hydrolyzate of starch or dextrin with hypochlorite or periodate. Here, there is no description about the structure of the polycarboxylic acid obtained after the oxidation reaction, especially the content of the carboxyl group. Although no clear measurement example regarding the molecular weight is shown, based on the distribution of the glucoside units disclosed in Example 5, the molecular weight does not decrease during the subsequent oxidation reaction, and it is oxidized to the maximum. Even if it is calculated assuming that three carboxyl groups are introduced per unit,
The weight average molecular weight is only 915. When starch or dextrin from which a higher molecular weight product is considered to be obtained is used as a raw material, as shown in Comparative Example 1, the obtained polycarboxylic acid has a Ca blocking ability of 200 and 200, respectively. It is still low at 225, indicating a low content of carboxyl groups in the oxidation product.

[0008]

DISCLOSURE OF THE INVENTION The present invention uses a polysaccharide having excellent biodegradability and having anhydrous glucose as a constituent unit, from which polycarboxylic acid or carboxylic acid having a high carboxyl group content and a large molecular weight is obtained. An object of the present invention is to provide a method for producing the salt and a detergent composition containing the same.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, an aqueous liquid containing a polysaccharide having an anhydrous glucose as a constitutional unit and a transition metal or a transition metal compound and a metal halide is subjected to electrolytic treatment to neutralize and titrate an acid-type polycarboxylic acid. The required alkali is 435 per gram of the polycarboxylic acid in terms of sodium hydroxide.
The present invention provides a method for producing a polycarboxylic acid or a salt thereof, wherein the method produces a polycarboxylic acid or a salt thereof having a weight average molecular weight of 5000 or more and a weight average molecular weight of 5000 or more.
Further, there is provided a detergent composition comprising the polycarboxylic acid or a salt thereof obtained by the above method and a surfactant.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the polycarboxylic acid salt obtained by the present invention, examples of the salt include salts of alkali metals such as Na, K and Li and salts of amines such as ammonia, alkylamine and alkanolamine. However, Na salt or K salt is preferred from the viewpoint of ease of production. Further, only a part of the carboxyl group may be converted to a salt.

The polycarboxylic acid or salt thereof obtained in the present invention is expected to be rapidly degraded in an aqueous solution and rapidly biodegraded by microorganisms even when discharged into the environment.

The raw material polysaccharide used for obtaining the polycarboxylic acid and the salt thereof of the present invention is not particularly limited as long as it is a polysaccharide having anhydrous glucose as a constitutional unit, and starch, dextrin, cellulose, or any of these is preferable. Examples of the hydrolyzate include amylose and amylopectin obtained by fractionating starch. These may be used in a mixture of two or more. The origin of these polysaccharides is not particularly limited. Used cellulose is used. Among these polysaccharides, use of starch or cellulose is preferred from the viewpoint of availability and economy,
Particularly preferably used is starch.

To carry out the method of the present invention, an electrolytic cell is
An aqueous liquid containing a polysaccharide, a transition metal or a compound thereof, and a metal halide is charged and subjected to electrolytic treatment. In this case, water or a solution containing water is used as the aqueous liquid. The concentration of polysaccharide in the aqueous liquid is 1 to 50 wt%, preferably 2 to 30 wt%.
wt%. The metal halide contained in the solution after the reaction can be reused.

As transition metals, Ru, Os, Mn, R
h, Ir, Pt, Pd, Ni and the like, and preferably Ru, Mn, Ni or Os. These metals may be used in the form of compounds such as chlorides, sulfates, sulfides, oxides, and hydroxides, or may be used as they are or supported on carriers such as carbon and alumina. These transition metals or compounds thereof are used in an amount of 0.001 to 1.0 mol, preferably 0.01 to 0.5 mol, more preferably 0.1 to 1 mol, per 1 mol of anhydrous glucose units of the polysaccharide.
02 to 0.3 mol.

As the metal halide, a water-soluble metal halide is used. Examples of such a metal halide include NaCl, KCl, L
In addition to alkali metal halides such as iCl, NaBr, KBr, NaI, and KI, MgCl ₂ , CaCl ₂ , MgB
Examples thereof include alkaline earth metal halides such as r ₂ and CaBr ₂ . The concentration of the metal halide in the aqueous liquid is 1 g or more, preferably 10 g or more per liter of the aqueous liquid, and more preferably an amount corresponding to its saturated solubility.

As the electrolytic cell, any of a non-diaphragm system and a diaphragm system can be used. As the electrodes, those used in ordinary electrolytic treatment, such as platinum, carbon, stainless steel, and other electrodes, as well as platinum group metals and platinum group metal oxides, and mixtures thereof coated on titanium etc. Electrodes and the like. The anode and cathode may be made of the same or different materials. The current density used in the electrolysis is 1 mA / cm ² or more, preferably ² to 100 mA / cm ² . The electrolysis temperature is
Although not particularly specified, it is preferably 5 to 50 ° C. This electrolytic treatment can be carried out by any of a batch system and a continuous system.

The pH of the electrolyte during the reaction is maintained in the range of 3 to 13, preferably 4 to 12. Adjustment of the pH
Buffers such as ₂ HPO ₄ , NaH ₂ PO ₄ , NaHCO ₃ , and Na ₂ CO ₃ can be used alone or in combination of two or more. Further, it can be carried out by adding a hydroxide of an alkali metal such as NaOH or KOH, or an amine such as ammonia, alkylamine or alkanolamine.

When a diaphragm type electrolytic cell is used as the electrolytic cell, a conventionally known diaphragm can be used as the diaphragm. These include ion exchange membranes and inorganic porous membranes. The ion exchange membrane includes a cation exchange membrane having a sulfonic acid group and an anion exchange membrane having a quaternary ammonium group. The porous film includes incinerated glass, ceramics, and the like. When a polysaccharide is electrolytically oxidized using a diaphragm type electrolytic cell, an aqueous liquid containing a polysaccharide, a transition metal or a transition metal compound and a metal halide compound is placed in the anode compartment, and sodium hydroxide or water is placed in the cathode compartment. Electrolytic oxidation is performed by adding an aqueous solution containing an electrolyte such as potassium oxide. In electrolytic oxidation using an electrolytic cell having such a cation exchange membrane as a diaphragm, the gas generated at the anode and the cathode is not mixed because the electrolytic cell is separated into two, an anode chamber and a cathode chamber, There is an advantage that they can be collected independently. Further, it is possible to prevent ruthenium tetroxide (having a volatile property) from being diffused out of the system by light hydrogen generated at the cathode. That is, loss of the tactile membrane during the reaction can be prevented.
Further, when a cation exchange membrane is used as the diaphragm and salt is used as the electrolyte in the anode chamber, only sodium hydroxide can be generated in the cathode chamber.

In the above-mentioned electrolytic treatment, oxidized species of halogen are generated in the electrolytic solution, which oxidize a transition metal or a compound thereof, and the oxidized transition metal or a compound thereof acts as an oxidizing agent to form a polysaccharide. To oxidize. Under such oxidation conditions, cleavage of the glucosidic bond of the main chain of the polysaccharide is relatively unlikely to occur, and the hydroxyl group of the polysaccharide is efficiently oxidized, and the weight average molecular weight is 5,000 or more. The salt can be obtained with good yield. Since this polycarboxylic acid or a salt thereof has a high molecular weight and a large content of a carboxyl group, it has a high chelating power against polyvalent cations such as Ca and Mg, and is suitably used as a detergent builder. In the polycarboxylic acid or the salt thereof obtained according to the present invention, the content of the carboxyl group is such that the alkali required for neutralizing and titrating the acid-type polycarboxylic acid is calculated as sodium hydroxide, per 1 g of the polycarboxylic acid. 435 mg or more, especially 486 mg / g or more
582 mg / g and a weight average sample of 50
00 or more, preferably 8000 to 50,000.

The carboxylic acid or a salt thereof obtained by the electrolytic treatment is preferably treated with a reducing agent. By the treatment using the reducing agent, the color tone of the electrolytic reaction product can be improved. The electrolysis reaction product is black or brown and has a poor color tone, but by applying a reducing agent treatment to the product, it can be improved to a color tone such as blue or yellow. Any reducing agent may be used as long as it has a lower oxidation-reduction potential than an oxidized species of halogen generated in the electrolyte, and is preferably a sulfite (a sodium salt, a potassium salt, an ammonium salt, or the like) or a nitrite salt (Sodium salt, potassium salt, ammonium salt, etc.), hydrogen peroxide and the like. The amount of these reducing agents used depends on the amount of the oxidizing agent remaining in the reaction system after the completion of the electrolytic reaction, but is generally in the range of 0.3 to 0.3 with respect to the remaining hypohalogen.
It is 10 times mole, preferably 0.5 to 5 times mole.

Next, methods for measuring the carboxyl group content, molecular weight and Ca ion chelating ability (CEC) of the polycarboxylic acid and its salt obtained by the present invention will be described below. [Measurement of Carboxyl Group Content] About 0.2 g (absolutely dry amount) of acid-type polycarboxylic acid is precisely weighed and weighed in a 200 ml conical beaker, and dissolved by adding about 50 ml of ion-exchanged water. Phenolphthalein as indicator
Titrate with a 1/10 normal sodium hydroxide standard solution, and indicate the carboxyl group content as mg of sodium hydroxide required to neutralize 1 g of the acid-form polycarboxylic acid.
When it is clear that a part or all of the polycarboxylic acid whose carboxyl group content is to be measured is in the form of a salt, the polycarboxylic acid is converted into an acid-form polycarboxylic acid and taken out by the following method. That is, about 1
A weight-% aqueous solution is prepared, and a cation exchange resin (DOWEX) is prepared.
50W-X8) is passed through a column packed with the mixture, and cation exchange is performed to convert the carboxylic acid into an acid-type polycarboxylic acid. The cation exchange resin is a polycarboxylate salt of 1
Use 10 ml per 1% by weight aqueous solution. The eluate is
By freeze-drying or drying under reduced pressure (40 ° C. or lower), an acid-type polycarboxylic acid is obtained in powder form. [Measurement of molecular weight by GPC] About 5 mg of the obtained powder of polycarboxylic acid or a salt thereof was mixed with 0.1 mol / l of Na
0.1m / l phosphate buffer (pH 7) containing Cl 5m
1 and then measured by GPC under the following conditions and expressed as a weight average molecular weight. Column used: Showex made by Showa Denko KK
Asahipak GS-2G + GS-520 + GS-3
20 + GS-220 Eluent: 0.1 mol / l NaCl.
1 mol / l phosphate buffer (pH 7) Elution rate: 0.5 ml / min Column temperature: 40 ° C. Sample injection volume: 200 μl Calibration curve: Standard pullulan (weight average molecular weight 0.130, 0, manufactured by Showa Denko KK) .290,000, 0.580,
122,000, 2.337,40.8,100,000,18.
60,000, 380,000, 859,000), using glucose, maltose and maltotriose

[Measurement of Ca ion chelating ability (CEC)] 0.1 mol / L CaCl manufactured by Orion Research
By diluting the _two standard solutions 100 times, a Ca solution corresponding to 100 ppm as CaCO ₃ was prepared. On the other hand, the polycarboxylic acid to be tested was dissolved in ion-exchanged water to prepare an aqueous solution containing exactly 1% by weight of sodium polycarboxylate, and used as a test solution. Ca solution 10
After taking 0 ml and adding 2 ml of a 4 mol / l KCl solution, the pH was adjusted to 10 with 1/10 N NaOH. While stirring this aqueous solution, the initial concentration of Ca ions was measured using a Ca ion electrode. Next, 2 ml of the test solution was accurately added, the pH was adjusted to 10 again, and the Ca ion concentration was measured using a Ca ion electrode. The Ca ion concentration after the addition of the test solution was subtracted from the initial concentration of Ca ions, and this amount was expressed as chelated Ca ions, and the amount of Ca ions chelated by Ig of Na polycarboxylate was expressed as mg of CaCO ₃ . .

The detergent composition of the present invention contains a surfactant and the above polycarboxylic acid or a salt thereof. In this case, as the surfactant, a conventional one, in particular, an anionic surfactant or a nonionic surfactant, or a mixture thereof is used.

The following are specific examples of the anionic surfactant. (1) a straight-chain alkylbenzene sulfonate having an alkyl group having an average carbon number of 8 to 16, (2) an average carbon number of 1
Α-olefin sulfonate of 0 to 20, (3) α-sulfofatty acid ester salt or di-salt of fatty acid sulfonate represented by the following formula,

Embedded image (R: alkyl group or alkenyl group having 8 to 20 carbon atoms Y: alkyl group having 1 to 3 carbon atoms or counter ion Z: counter ion) (4) alkyl sulfate having an average carbon number of 10 to 20,
(5) alkyl ether sulfates or alkenyl ether sulfates having a linear or branched alkyl or alkenyl group having an average of 10 to 20 carbon atoms and having an average of 0.5 to 8 mol of ethylene oxide added thereto, (6) ) Saturated or unsaturated fatty acid salts having an average of 10 to 22 carbon atoms. As the counter ion in the above anionic surfactant,
Usually, alkali metal ions such as sodium and potassium are suitable.

Examples of the nonionic surfactant include the following. (7) alcohol ethoxylate obtained by adding ethylene oxide to alcohol, (8) nonylphenol ethoxylate, (9) adduct obtained by adding propylene oxide and ethylene oxide to alcohol, (10)
Fatty acid alkanolamides, (11) sucrose fatty acid esters, (12) alkylamine oxides. Among the above nonionic surfactants, in particular, those having 8 to 2 carbon atoms.
2, preferably 8 to 18 saturated or unsaturated aliphatic primary
Alcohol ethoxylates obtained by adding an average of 10 to 30 moles, preferably 12 to 20 moles of ethylene oxide to a primary or secondary alcohol are preferred, and alcohol ethoxylates obtained by adding an ethylene oxide to an aliphatic primary alcohol are particularly preferred. .

The following nonionic surfactants may be used as the nonionic surfactant. (13) An ester type nonionic surfactant represented by the following formula,

Embedded image (R ¹ : C 6-22, preferably C 10-18
R ² : alkylene group having 2 to 4 carbon atoms, preferably 2 carbon atoms, R ³ : alkyl group having 1 to 4 carbon atoms, n: OR ² It indicates the average number of moles added, and indicates a number of 5 to 30, preferably 7 to 20)

The ester-type nonionic surfactant (13) is structurally an alkyl ether of an alkylene oxide adduct of a fatty acid. The alkylene oxide is added to an alcohol by a conventional method, followed by esterification with a fatty acid. Can be obtained by the two-stage method, but trivalent aluminum ion, gallium ion, indium ion, thallium ion, cobalt ion, scandium ion,
In the presence of a catalyst comprising magnesium oxide to which one or more metal ions selected from lanthanum ions and divalent manganese ions have been added, the fatty acid alkyl ester R
Those produced also by a one-stage method of reacting ¹ COOR ³ with an alkylene oxide are preferred.

[0028] The detergent composition of the present invention can contain an alkaline agent. As the alkaline agent, carbonate, hydrogen carbonate, sesquicarbonate, silicate, alkanolamine and the like are used. In the composition of the present invention, the polycarboxylic acid or the salt thereof is contained in the detergent composition in an amount of 5 to 70% by weight,
Preferably, it is used at a rate of 10 to 50 wt%. As the builder other than the polycarboxylic acid or a salt thereof, aluminosilicate, layered silicate, ethylenediaminetetraacetate,
Nitrilotriacetate, tripolyphosphate, polyacrylate, acrylic acid / maleic acid copolymer salt, citrate and the like can be used in combination. In the detergent composition, as optional components other than the above components, enzymes such as protease, lipase, cellulase, amylase and keratinase; bleaching agents such as sodium percarbonate and sodium perborate; recontamination with carboxymethylcellulose, polyethylene glycol and the like Inhibitors: soaps, optical brighteners, fragrances, dyes and the like can be used.

[0029] The composition of the present invention may be in the form of powder, granules, liquid and the like. When a high-density granular detergent composition is used, each component is granulated to obtain a high-density granular detergent composition having a bulk density of 0.6 to 1.2 g / cc. This granulation method is described in JP-A-60-96698 and the like. The composition of the present invention is obtained by kneading and mixing detergent raw materials such as a composition surfactant with a kneader, crushing and granulating with a crusher such as a cutter mill type, and further mixing the water-insoluble fine powder. Can be Alternatively, a part or all of the detergent components may be spray-dried in advance, and the spray-dried product and the remaining detergent components may be kneaded and mixed to produce high bulk density detergent particles. Alternatively, the spray-dried particles and other detergent components can be stirred and granulated to produce high bulk density detergent particles.
Components such as enzymes and builders may be powder blended with the granulated detergent. It is preferable that the polycarboxylic acid or a salt thereof is powder-mixed after the above crushing and granulation. In addition, when preparing spray-dried detergent particles and stirring and granulating the particles while spraying a binder on the particles to obtain high bulk density granular detergent particles, the polycarboxylic acid or a salt thereof may be added. Of course, the polycarboxylic acid or a salt thereof may be powder-mixed with the high bulk density granular detergent particles obtained after the completion of the stirring granulation.

[0030]

The present invention will be described below in detail with reference to examples. PH in 0.2 M NaH ₂ PO ₄ in Example 1 100 ml beaker
100 ml of a saturated saline solution adjusted to 4 was added, and the mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content: 52 wt%) were absolutely dried.
Disperse 200 mg (0.167 mol per mol of anhydrous glucose units of starch). When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density is a constant current electrolytic oxidation at 20 mA / cm ² For 3 hours. The initial voltage at this time was 2.9V. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 520 mg, and the weight average molecular weight was 94.
00 and the CEC was 330 mg / g.

Example 2 An experiment was conducted in the same manner as in Example 1 except that a saturated saline solution adjusted to pH 9 with 0.2 M NaHCO ₃ was used. The carboxyl group content of the obtained polycarboxylic acid Na was 490 mg, the weight average molecular weight was 19000,
CEC was 360 mg / g.

Example 3 100 ml of saturated saline was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
200 mg (16.7 mol% based on the anhydrous glucose units of the starch) are dispersed. Internal temperature is 20 ℃
At this point, the electrodes were immersed so that the current-carrying area was 18 cm ² by using a platinum electrode having a width of 3 cm for the anode and the cathode, and electrolytic oxidation was performed at a current density of 20 mA / cm ² for 3 hours. The initial voltage at this time was 2.5V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 10. After the completion of the oxidation reaction, 1 g of sodium sulfite was added for reduction, insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution is
After purification by ultrafiltration, powder of sodium polycarboxylate was obtained by drying under reduced pressure. Na polycarboxylate obtained
Had a carboxyl group content of 517 mg, a weight average molecular weight of 12000 and a CEC of 368 mg / g.

Example 4 An experiment was conducted in the same manner as in Example 3, except that the pH in the system was adjusted to 7. The carboxyl group content of the obtained sodium polycarboxylate is 455 mg, and the weight average molecular weight is 11
800 and the CEC was 310 mg / g.

Example 5 100 ml of saturated saline was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
50 mg (anhydrous glucose unit 1 of starch)
(0.042 mol per mol). Internal temperature is 2
When it becomes 0 ° C., by using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density was carried out for 3 hours electrolytic oxidation at 20 mA / cm ² . The initial voltage at this time was 2.5V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After completion of the oxidation reaction, insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 486 mg, and the weight average molecular weight was 10500.
And the CEC was 304 mg / g.

Comparative Example 1 In Example 5, RuO ₂ .xH ₂ O (Ru content 52
(wt%) was not used. The carboxyl group content of the obtained sodium polycarboxylate is 3
3 mg, the weight average molecular weight was 80,000, and the CEC was 5 mg / g.

Example 6 100 ml of a saturated saline solution was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
200 mg (0.167 mol per mol of anhydrous glucose units of starch) is dispersed. When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 5 mA / cm ² 6 Time went. The initial voltage at this time was 2.3 V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate is 460 mg, and the weight average molecular weight is 12
000 and the CEC was 307 mg / g.

Example 7 100 ml of saturated saline was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
200 mg (0.167 mol per mol of anhydrous glucose units of starch) is dispersed. When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 9cm ^2, current density electrolytic oxidation at 80 mA / cm ² 3 Time went. The initial voltage at this time was 3.5V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate is 546 mg, and the weight average molecular weight is 16
700 and the CEC was 390 mg / g.

Example 8 100 ml of a saturated saline solution was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
200 mg (0.167 mol per mol of anhydrous glucose units of starch) is dispersed. When the internal temperature reached 40 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 20 mA / cm ² 3 Time went. The initial voltage at this time was 2.5V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate is 584 mg, and the weight average molecular weight is 1
0000 and the CEC was 319 mg / g.

Example 9 100 ml of a saturated saline solution was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
200 mg (0.167 mol per mol of anhydrous glucose units of starch) is dispersed. When the internal temperature reached 20 ° C., the electrode was immersed so that the current-carrying area was 18 cm ² using a platinum electrode having a width of 3 cm as an anode and a carbon electrode as a cathode, and electrolysis was performed at a current density of 20 mA / cm ² . The oxidation was performed for 3 hours. The initial voltage at this time is 2.5V
Met. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 559 mg, the weight average molecular weight was 15,000, and the CEC was 374 mg /
g.

Example 10 100 ml of saturated saline was added to a 100 ml beaker.
Stir with a magnetic stirrer and disperse 1 g of corn starch and 248 mg of RuCl ₃ .xH ₂ O (Ru content 42 wt%) (0.167 mol per mol of anhydrous glucose unit of starch) by absolute dry weight. When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 40 mA / cm ² 3
Time went. The initial voltage at this time was 3V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 533 mg, and the weight average molecular weight was 16
300 and the CEC was 388 mg / g.

Example 11 100 ml of a 2 wt% saline solution was added to a 100 ml beaker, and the mixture was stirred with a magnetic stirrer to give 1 g in absolute dry weight.
Corn starch and 200 mg of RuO ₂ .xH ₂ O (Ru content: 52 wt%) (0.167 mol per mol of anhydrous glucose units of starch) are dispersed. When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 40 mA / cm ² 6 Time went. The initial voltage at this time was 5V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 493 mg, and the weight average molecular weight was 1
3500 and CEC was 354 mg / g.

Example 12 100 ml of a saturated saline solution was added to a 100 ml beaker.
Stir with a magnetic stirrer and disperse 10 g of corn starch and 2000 mg of RuO ₂ .xH ₂ O (Ru content: 52 wt%) (0.167 mol per mol of anhydrous glucose unit of starch) by absolute dry weight. When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 20 mA / cm ² 3 Time went. The initial voltage at this time was 2.5V.
During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10 and 1 g of Na sulfite was added.
Reduction was performed by addition, and insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. Na polycarboxylate obtained
Had a carboxyl group content of 500 mg, a weight average molecular weight of 11,000 and a CEC of 310 mg / g.

Example 13 100 ml of a saturated saline solution was added to a 100 ml beaker,
The mixture was stirred with a magnetic stirrer, and 1 g of cellulose powder (reagent) and 200 mg of RuO ₂ .xH ₂ O (Ru content: 52 wt%) (0.167 mol with respect to 1 mol of anhydrous glucose unit of starch) were mixed by absolute dry weight. Disperse.
When the internal temperature reached 20 ° C., using a platinum electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 20 mA / cm ² 3 Time went. The initial voltage at this time was 2.5V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the end of the oxidation reaction, the pH was adjusted to 10 and
Was added, and reduction was performed. Insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 450 mg, the weight average molecular weight was 18,000, and the CEC was 325 mg / g.
Met.

Example 14 100 ml of saturated saline was added to a 100 ml beaker,
The mixture was stirred with a magnetic stirrer, and 1 g of amylopectin and RuO ₂ .xH ₂ O (Ru content 52 wt.
%) (0.167 mol per mol of anhydrous glucose units of starch). When the internal temperature reached 5 ° C., using a 3 cm wide platinum electrode as the anode and the cathode, the electrode was immersed so that the current-carrying area was 18 cm ² ,
Electrolytic oxidation was performed at a current density of 20 mA / cm ² for 3 hours. The initial voltage at this time was 2.5V. P during the reaction
Using a H-stat, a 2N aqueous sodium hydroxide solution was added to adjust the pH in the system to 8.5. After the completion of the oxidation reaction, the pH was adjusted to 10, and 1 g of Na sulfite was added to perform reduction. The insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a sodium polycarboxylate.
Was obtained. The carboxyl group content of the obtained sodium polycarboxylate was 500 mg, and the weight average molecular weight was 1550.
0 and the CEC was 360 mg / g.

Example 15 100 ml of a saturated saline solution was added to a 100 ml beaker.
The mixture was stirred with a magnetic stirrer, and 1 g of corn starch and RuO ₂ .xH ₂ O (Ru content 5
200 mg (0.167 mol per mol of anhydrous glucose units of starch) is dispersed. When the internal temperature reached 20 ° C., using a platinum coating of titanium electrode width 3cm an anode and a cathode, immersed electrodes so energized area is 18cm ^2, the current density electrolytic oxidation at 20 mA / cm ² For 3 hours. The initial voltage at this time was 2.3 V. During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the system to 8.5. After the end of the oxidation reaction, the pH was adjusted to 10 and
Was added, and reduction was performed. Insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate was 515 mg, the weight average molecular weight was 15,200, and the CEC was 354 mg / g.
Met.

Example 16 An experiment was conducted in the same manner as in Example 15 except that a carbon electrode was used instead of the platinum-coated electrode. The initial voltage at this time was 3V. The carboxyl group content of the obtained sodium polycarboxylate was 534 mg, the weight average molecular weight was 16,500, and the CEC was 388 mg / g.

Comparative Example 2 In Example 15, the reaction was carried out without supplying electricity. No powder of sodium polycarboxylate was obtained.

Example 17 Selective cation exchange resin membrane (Nafion manufactured by DuPont)
-117) was used as a diaphragm, 100 ml of saturated saline was put into the anode chamber of the diaphragm type electrolytic cell separated with a magnetic stirrer, and 1 g of corn starch and RuO2 x H2O (Ru content 52 %) 1
Disperse 00 mg (0.084 mole per mole of anhydrous glucose units of starch). 0.01 in the cathode compartment
100 ml of N aqueous sodium hydroxide solution are charged. When the internal temperature reached 20 ° C., a 30 mm-wide platinum electrode was placed in the anode chamber side and a 30 mm-wide stainless steel plate was placed in the cathode chamber side, and the electrodes were immersed so that the current-carrying area was 18 cm ^2. Was performed at 30 mA / cm ² for 3 hours.
During the reaction, a 2N aqueous sodium hydroxide solution was added using a pH stat to adjust the pH in the anode chamber to 8.5. After the end of the oxidation reaction, the pH was adjusted to 10 and
Was added, and reduction was performed. Insolubles were removed by filtration, and the reaction solution was taken out. The reaction solution was purified by performing dialysis for diffusion for 5 days with ion-exchanged water, and then freeze-drying to obtain a powder of sodium polycarboxylate. The carboxyl group content of the obtained sodium polycarboxylate is 550 mg, the weight average molecular weight is 12000, and the CEC is 408 mg /
g.

Detergent Composition Preparation Example 1 Sodium linear alkylbenzene sulfonate (alkyl group C ₁₀ -C ₁₄ ) 20 wt%, C ₁₂ -C ₁₃ alcohol ethoxylate 5 wt%, sodium carbonate 20 wt%, Acid salt 20wt%, sulfite Na2
wt%, fluorescent agent (Tinopearl CBS-X) 0.15wt
%, Protease (Sabinase 6.0T) 0.3wt
%, Water content 10% by weight, sodium sulfate: a high-density granular detergent (bulk density: 0.95 g / cc) consisting of a balance was evaluated for its detergency. The detergency was 84%.
And was good.

Comparative Detergent Composition Preparation Example 1 A detergent composition was prepared in the same manner as in Detergent Composition Preparation Example 1 except that no polycarboxylate was used, and its detergency was evaluated. The detergency was 76%. Met.

The detergency shown above was measured as follows. (I) Preparation of Artificial Soil A clay mainly composed of a crystalline mineral such as kaolinite or vermiculite was dried at 200 ° C. for 30 hours and used as inorganic soil. After dissolving 3.5 g of gelatin in about 950 cc of water at about 40 ° C., 0.25 g of carbon black was dispersed in water using a powerful emulsifying and dispersing machine, Polytron (manufactured by KINEMATICA, Switzerland). Next, 14.9 g of inorganic soil was added and emulsified with Polytron,
Further, 31.35 g of organic dirt was added and emulsified and dispersed with Polytron to prepare a stable dirt bath. 10c in this dirty bath
After immersing a predetermined cleaning cloth (cotton cloth No. 60 designated by the Japan Oil Chemistry Association) of mx 20 cm, water was squeezed with two rubber rolls to uniform the amount of dirt attached. 105 ℃
For 30 minutes, and then rubbed both sides of the soiled cloth 25 times each on the left and right. This was cut into 5 cm × 5 cm, and the one having a reflectance in the range of 42 ± 2% was provided to a dirty cloth. The soil composition of the artificial soil cloth thus obtained is shown in Table 1.

[0052]

[Table 1] ───────────────────────────── Soil component composition (wt%) ───────── ──────────────────── Organic Soil Oleic acid 28.3 Triolein 15.6 Cholesterol oleate 12.2 Liquid paraffin 2.5 Squalene 2.5 Cholesterol 6 Total oily soil 62.7 ───────────────────────────── Gelatin 7.0 ───────── ──────────────────── Inorganic dirt 29.8 Carbon black (designated by the Japan Oil Chemicals Association) 0.5 ──────────── ─────────────────

(Ii) Washing method S. Testing Terg-O-Tomet
Then, 10 artificial soiling cloths and a knitted cloth are put into the bath, the bath ratio is adjusted to 30 times, and the washing is performed at 120 rpm and 25 ° C. for 10 minutes. The cleaning solution has a detergent concentration of 0.083 w
Rinse with 900 ml of water for 3 minutes using 900 ml of t%. The water used is 3 ゜ DH.

(Iii) Evaluation method The cleaning rate was determined by the following formula, and the cleaning power was evaluated.

[0055]

(Equation 1)

Here, R is an EL manufactured by Carl Twice.
It is a reflectance (%) measured by a REPHO reflectometer. The evaluation of the detergency was carried out by the average value of 10 test artificial soil cloths.

[0057]

According to the present invention, a polysaccharide is used as a raw material, from which a polycarboxylic acid or a salt thereof having a high carboxyl group content and a high molecular weight can be suppressed in the formation of by-products, thereby improving the yield and the yield. At a low cost. The polycarboxylic acid or salt thereof obtained according to the present invention can be used as a dispersant, a chelating agent, a flocculant, etc.
Because of its high carboxyl group content and high chelating power against polyvalent cations such as Ca and Mg, it is suitable as a detergent builder. The detergent composition of the present invention,
It has high detergency due to the high chelating action of the polycarboxylic acid or its salt contained therein on polyvalent cations.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Hata 1-3-7 Honjo, Sumida-ku, Tokyo Inside Lion Corporation

Claims (2)

[Claims] 1. An aqueous solution containing a polysaccharide having anhydrous glucose as a constitutional unit, a transition metal or a transition metal compound, and a metal halide is subjected to electrolytic treatment, and an alkali required for neutralizing and titrating an acid-type polycarboxylic acid is obtained. , In terms of sodium hydroxide, 435 mg or more per 1 g of the polycarboxylic acid,
And producing a polycarboxylic acid or a salt thereof having a weight average molecular weight of 5000 or more. 2. A cleaning composition comprising the polycarboxylic acid or its salt obtained in claim 1 and a surfactant.