JPH10195102A - Polycarboxylic acid derived from polysaccharide comprising anhydroglucose structural unit or salt thereof and detergent composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polycarboxylic acid (salt) having excellent biodegradability, a high carboxyl content and a high molecular weight by oxidizing a polysaccharide comprising anhydroglucose structural units. SOLUTION: To a dispersion prepared by dispersing a polysaccharide comprising anhydroglucose structural units, 0.05-10mol%, based on the anhydroglucose units, transition metal catalyst and 3-12mol, per mol of the anhydroglucose units, of an oxidizing agent are added. The polysaccharide is then oxidized at 5-50 deg.C for 2-24hr, while the pH is kept at 6-13 by the addition of e.g. an alkali metal hydroxide or an amine to obtain a polycarboxylic acid (salt) comprising 70-100mol% structural units of formula I and 0-30mol% structural units of formula II, having a weight-average molecular weight of 5,000 or above and represented by formula III (X is an H ion or a salt-forming ion; m is 70-100; n is 0-30; and m+n=100). 5-70wt.% this polycarboxylic acid (salt) being a builder is mixed with an anionic surfactant and/or a nonionic surfactant, an alkali agent, etc., to obtain a detergent composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarboxylic acid or a salt thereof produced by oxidation of a polysaccharide having anhydrous glucose as a constitutional 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.

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 relates to a polycarboxylic acid having a high carboxyl group content and a large molecular weight, which is excellent in biodegradability and is derived from the oxidation of a polysaccharide having anhydrous glucose as a constituent unit. Another object is to provide a salt thereof and a detergent composition containing the salt.

[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, a tricarboxylic acid or a salt thereof having a weight average molecular weight of 5,000 or more and represented by the following general formula (1) derived by oxidizing a polysaccharide having anhydrous glucose as a structural unit, and a salt thereof There is provided a detergent composition comprising:

Embedded image In the above formula, X represents a hydrogen ion or a salt-forming cation. m and n are mol% of each structural unit contained in the molecule, m represents a number of 70 to 100, n represents a number of 0 to 30, and the sum of n and m is 100.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the polycarboxylic acid salt of 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. From the viewpoint of ease of production, Na salt or K salt is preferred. Further, only a part of the carboxyl group may be converted to a salt.

The polycarboxylic acid or a salt thereof of the present invention is expected to be rapidly decomposed 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.

The polycarboxylic acid and its salt of the present invention can be obtained by highly oxidizing a polysaccharide having anhydrous glucose as a constitutional unit using a combination of a specific catalyst and an oxidizing agent. That is, it can be produced by adding an oxidizing agent to an aqueous dispersion of a polysaccharide and a transition metal catalyst while maintaining the pH of the solution in a certain range.

As the transition metal catalyst, Ru, Os, R
Examples thereof include h, Ir, Pt, Pd, and Ni, and are preferably a ruthenium catalyst or an osmium catalyst. These metal catalysts may be used in the form of a salt such as chloride, sulfide or oxide, or may be used as a metal. These transition metal catalysts are used in an amount of 0.05 mol% to 10 mol%, preferably 0.1 mol% to 7 mol%, more preferably 0.5 mol% to 10 mol% with respect to the anhydrous glucose unit of the polysaccharide.
~ 5 mol%.

As the oxidizing agent, hypohalite (for example, Na salt, K salt, Ca salt, Mg salt, etc.) and ash powder are used, and preferably, hypohalite is used.
The amount of these oxidizing agents varies depending on the content of the carboxyl group in the polycarboxylic acid to be finally obtained, but is usually 3 to 12 moles, preferably 3 to 12 moles per anhydroglucose unit of the polysaccharide. 4 times to 9 times mole. The reaction is carried out by adding these oxidizing agents to an aqueous dispersion of a polysaccharide and a transition metal catalyst. The method of adding the oxidizing agent is not particularly limited, but it is usually added continuously or dividedly. The reaction time is not particularly limited, but is usually 2 hours to 24 hours, preferably 3 to 18 hours. Although the reaction temperature is not particularly limited, it is usually 5 ° C.
-50 ° C, preferably 10-40 ° C.

The pH of the solution during the reaction is kept in the range of 6 to 13, preferably 7 to 12. The pH can be adjusted using an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide, or an amine such as ammonia, an alkylamine, or an alkanolamine. Sodium oxide or potassium hydroxide is used.

Under the above-mentioned reaction conditions, the cleavage of the glucoside bond of the main chain of the polysaccharide is relatively unlikely to occur, the hydroxyl group of the polysaccharide is efficiently oxidized, and the weight average molecular weight of the polycarboxylic acid is 5,000 or more. An acid or a salt thereof can be obtained. 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.

The polycarboxylic acid or its salt produced by the oxidation of the polysaccharide according to the present invention comprises the structural units A and B represented by the following formulas (2) and (3). (Structural unit A)

Embedded image (Wherein, X has the same meaning as described above) (Structural unit B)

Embedded image

In the polycarboxylic acid or salt thereof according to the present invention, the ratio of the structural unit A to the structural unit B and the molecular weight thereof vary depending on the kind of the starting polysaccharide, the kind of the oxidizing agent, the kind of the catalyst and the reaction conditions. However, the content of the structural unit A in the molecule is from 70 to 100 mol%, the content of the structural unit B is from 0 to 30 mol%, and preferably only the structural unit A. When the content of the structural unit A is less than 70 mol%, the chelating power of the polyvalent cation is inferior. Further, the tricarboxylic acid or a salt thereof in the structural unit A is rapidly decomposed in an aqueous solution, the molecular weight is reduced, and biodegradation by a microorganism is easy. Depending on the reaction conditions, the following structural unit C composed of a dicarboxylic acid or a salt thereof may be formed. However, it has been clarified that the structural unit C is hardly decomposed in an aqueous solution and is not easily biodegraded. (Structural unit C)

Embedded image (Wherein, X has the same meaning as described above)

In producing the polycarboxylic acid or a salt thereof of the present invention, the structural unit C is not substantially contained, and the structural unit A is 70 to 100 mol%, preferably 80 to 10 mol%.
0 mol% and structural unit B: 0 to 30 mol%, preferably 0
The starting polysaccharide is oxidized so as to obtain a product consisting of ２０20 mol%. In this case, in order to obtain a product substantially free of the structural unit C, the oxidizing agent is added slowly to keep the oxidation reaction rate of the raw material polysaccharide high. Generally, the oxidizing agent is added at a rate of 6 moles or less, preferably 0.5 to 4 moles, per mole of anhydrous glucose per hour.

The molecular weight of the polycarboxylic acid or a salt thereof of the present invention is 5,000 or more, preferably 8,000 to 50,000, by weight average molecular weight. The polycarboxylic acid or salt thereof of the present invention is preferably synthesized by using starch as a raw material polysaccharide and oxidizing the same with hypochlorite or salami powder in the presence of a ruthenium catalyst.

Next, the molecular weight, the Ca ion chelating ability (CEC) of the polycarboxylic acid and the salt thereof of the present invention,
The methods for measuring the contents of the structural units A and B and the carboxylic acid decomposition rate will be described below. [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: Shodex Asahipak GS-2G + GS-520 + GS-320 + GS-220 manufactured by Showa Denko KK Eluent: 0.1 mol / l phosphate buffer (pH 7) containing 0.1 mol / l NaCl Elution rate: 0 Column temperature: 40 ° C. Sample injection volume: 200 μl Calibration curve: Standard pullulan manufactured by Showa Denko KK (weight average molecular weight 0.130, 0.29, 0.58, 122,000, 2.37,000, 48,000, 100,000, 186,000, 380,000, 859,000), using glucose, maltose, maltotriose

[Measurement of Ca ion chelating ability (CEC)] CaCl 0.1 mol / L 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 Ca ion concentration, and this amount was used as the chelated Ca ion, and the amount of C that was obtained by chelating lg of polycarboxylate Na was used.
The amount of a ions was expressed as mg of CaCO ₃ .

[Measurement of Structural Units A and B] About 10 mg of polycarboxylic acid or a salt thereof was placed in a test tube, 5 ml of IN hydrochloric acid was added, and the mixture was sealed and left at 100 ° C. for 16 hours to carry out hydrolysis. After evaporating the solvent and drying under reduced pressure, the residue was dissolved in 5 ml of eluent, and the amount of each organic acid and glucose produced by decomposition was measured by HPLC. The structure of the polycarboxylic acid before hydrolysis was identified from the measured amounts of each organic acid and glucose. Column used: SHOdex RSpak KC-LG + KC-811 × 2 manufactured by Showa Denko KK Eluent: 3.75 mM perchloric acid aqueous solution Elution rate: 0.5 ml / min Column temperature: 40 ° C. Sample injection volume: 200 μl

In a polycarboxylic acid produced by performing an oxidation reaction of a polysaccharide having anhydrous glucose as a structural unit, three types of oxide structures of the anhydrous glucose structural unit are considered, and each of these structural units is Hydrolysis of this gives a specific organic acid. Therefore,
The structure of the polycarboxylic acid before the hydrolysis can be known from the type and amount of the organic acid. That is, the polycarboxylic acid in which only the 6-position hydroxyl group is oxidized is glucuronic acid by hydrolysis, and the polycarboxylic acid in which the 2- or 3-position hydroxyl group is oxidized is erythronic acid and glyoxylic acid.
Tartaric acid and glyoxylic acid are generated from a polycarboxylic acid in which all the hydroxyl groups at positions 2, 3, and 6 have been oxidized. Therefore, the presence or absence of glucuronic acid, erythronic acid, and tartaric acid indicates the structural unit of the polycarboxylic acid before hydrolysis. In this case, a reaction route in which each structural unit of the polycarboxylic acid is converted into an organic acid is shown below in relation to each structural unit containing a carboxylic acid.

[0026]

Embedded image

[Decomposition rate of polycarboxylic acid] A 0.1 wt% aqueous solution of polycarboxylic acid or a salt thereof (pH 7) 20
ml is sealed in a 200 ml glass bottle, stored at 50 ° C. for one month, and the change in molecular weight is measured.

The detergent composition of the present invention contains a surfactant and the above-mentioned 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.

Specific examples of the anionic surfactant include the following. (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-mentioned anionic surfactant, an alkali metal ion such as sodium or potassium is usually 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 alkanolamide, (11) sucrose fatty acid Esters, (12) alkylamine oxides. Among the above nonionic surfactants, in particular, those having 8 carbon atoms
Alcohol ethoxylates obtained by adding an average of 10 to 30 moles, preferably 12 to 20 moles of ethylene oxide to saturated or unsaturated aliphatic primary or secondary alcohols of from 22 to 22, preferably from 8 to 18 are suitable. Alcohol ethoxylates obtained by adding ethylene oxide to aliphatic primary alcohols are particularly preferred.

Further, as the nonionic surfactant, the following ester type nonionic surfactant may be used. (1
3) an ester-type nonionic surfactant represented by the following formula:

Embedded image (R ¹ : 6 to 22 carbon atoms, preferably 10 to ¹ carbon atoms)
8 linear or branched alkyl or alkenyl groups, 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 Represents an average number of added moles, and represents 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, and is formed by adding an alkylene oxide to an alcohol by a conventional method, followed by esterification with the 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.

[0033] 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 a salt thereof is used in the detergent composition at a ratio of 5 to 70 wt%, preferably 10 to 50 wt%. Examples of the builder other than the polycarboxylic acid or a salt thereof include aluminosilicate, ethylenediaminetetraacetate, nitrilotriacetate, tripolyphosphate, polyacrylate, salt of allylic acid / maleic acid copolymer, and citrate. 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.

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.

[0035]

The present invention will be described below in detail with reference to examples. Example 1 In a 500 ml separable flask equipped with a stirrer, an oxidizing agent dropping funnel, a sodium hydroxide aqueous solution dropping port, a pH electrode, and a thermometer, 10 g of corn starch, 100 g of ion-exchanged water, and RuCl were added in an absolute dry weight. ₃・ n
0.49 g of H ₂ O (Ru content 38% by weight) (3 mol% based on anhydrous glucose units of starch) was weighed. Then, the mixture was cooled in a water bath at 20 ° C., and when the internal temperature reached about 20 ° C., a 12% by weight aqueous solution of sodium hypochlorite 230%
g (6 moles per anhydroglucose unit of starch)
Was added over 6 hours. During this time, a 2N aqueous sodium hydroxide solution was added using a pH stat,
The pH in the system was controlled at 9. After the completion of the addition of sodium hypochlorite, the reaction mixture was slowly poured into about 1 liter of ethanol to precipitate a reaction product. The obtained precipitate was dissolved in 150 ml of ion-exchanged water, purified by diffusion dialysis with ion-exchanged water for 5 days, and then freeze-dried to obtain 7.2 g of sodium polycarboxylate powder. The weight average molecular weight of the obtained sodium polycarboxylate is 15,000, and its structure is such that the content of the structural unit A (sodium tricarboxylate) is 100 mol%, and the unoxidized anhydrous glucose is 0 mol%. Met. Also, the C
a The ion chelating ability was 420 mg / g. Furthermore,
After storing the 0.1 wt% aqueous solution at 50 ° C. for one month, the molecular weight was reduced to 1,500.

Reference Example 1 3 g of the sodium polycarboxylate obtained in Example 1 was dissolved in 50 g of ion-exchanged water, the pH was adjusted to 3.0 with 1N hydrochloric acid, and then a hot water bath at 80 ° C. 2 while heating with
Hydrolysis was performed by stirring with a magnetic stirrer for an hour. Next, the mixture was cooled to room temperature, adjusted to pH 10 with 1N sodium hydroxide, and poured into 500 ml of ethanol to precipitate. The resulting precipitate was dissolved in 30 ml of ion-exchanged water and diffused with ion-exchanged water for 5 days. Dialysis was performed, and the hydrolyzed sodium polycarboxylate was freeze-dried for 1.5 times.
g was obtained. The weight average molecular weight of the hydrolyzed sodium polycarboxylate was reduced to 3600, and its CEC was also reduced to 250 mg / g. This indicates that the polycarboxylic acid of the present invention or a salt thereof has hydrolyzability.

Example 2 Example 1 was repeated except that instead of RuCl ₃ .nH ₂ O (Ru content 38% by weight), 0.47 g of osmium tetroxide (3 mol% per anhydroglucose unit of starch) was used. 6.5 g of Na polycarboxylate was obtained in the same manner as described above.
The weight average molecular weight of the obtained sodium polycarboxylate is 126.
This is composed of 73 mol% of the structural unit A (Na tricarboxylate) and 27 mol% of the structural unit B (anhydroglucose) 27
Mol%. The CEC is 3
It was 60 mg / g. Furthermore, the molecular weight of the 0.1 wt% aqueous solution after storage at 50 ° C. for one month was reduced to 1300.

Example 3 7.5 g of sodium polycarboxylate was obtained in the same manner as in Example 1 except that 10 g of cellulose powder (reagent) was used instead of corn starch. The weight average molecular weight of the obtained sodium polycarboxylate is 18,000,
This was composed of 77 mol% of the structural unit A (Na tricarboxylate) and 23 mol% of the structural unit B (anhydroglucose). The CEC is 380 mg / g
Met. Further, the 0.1 wt% aqueous solution is heated to 50 ° C.
After storage for months, the molecular weight had dropped to 1500.

Examples 4 to 8 Types of polysaccharides, types and amounts of catalysts, and sodium hypochlorite (Na
In the same manner as in Example 1 except that the reaction conditions such as the amount of ClO) and the pH during the reaction were changed, a sodium polycarboxylate was obtained. Table 1 shows the obtained results.

[0040]

[Table 1]

The R of the carbon-supported Ru shown in Table 1
The u content is 5% by weight, and both the catalytic amount and the amount of NaClO used are the amounts of polysaccharide used per anhydroglucose unit.

Comparative Example 1 7.5 g of sodium polycarboxylate was obtained in the same manner as in Example 1 except that RuCl ₃ .nH ₂ O was not used.
The weight average molecular weight of the obtained sodium polycarboxylate is 180
It is composed of 7 mol% of the structural unit A (Na tricarboxylate) and 63 mol% of the structural unit C (Na dicarboxylate).
It consisted of 30 mol% of the structural unit B (anhydroglucose) and 30 mol%. The CEC is 290 mg /
g. Further, the molecular weight of the 0.1 wt% aqueous solution after storage at 50 ° C. for one month was almost unchanged at 16,000.

Detergent Composition Preparation Example 1 Sodium linear alkyl benzene sulfonate (alkyl group C ₁₀ -C ₁₄ ) 20 wt%, C ₁₂ -C ₁₃ alcohol ethoxylate 5 wt%, sodium carbonate 20 wt%, polycarboxylic acid of Example 1 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 88%.
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 the 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.

[0046]

[Table 2] 汚 Soil component composition (wt%) ───────── ──────────────────── Organic soil 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.

(Equation 1) (Kuberka Munch formula)

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.

[0050]

The polycarboxylic acid of the present invention or a salt thereof is
Although it can be used as a dispersant, chelating agent, flocculant, etc., it is particularly suitable as a detergent builder because of its high carboxyl group content and high chelating power against polyvalent cations such as Ca and Mg. The detergent composition of the present invention has a high detergency due to the high chelating action of the polycarboxylic acid or a salt thereof contained on the polyvalent cation.

Claims (3)

[Claims] 1. A polycarboxylic acid or a salt thereof having a weight average molecular weight of 5,000 or more and represented by the following general formula (1) derived by oxidizing a polysaccharide having anhydrous glucose as a structural unit. Embedded image (Wherein X represents a hydrogen ion or a salt-forming cation,
m shows the number of 70-100, n shows the number of 0-30, and the sum of n and m is 100) 2. The polycarboxylic acid or a salt thereof according to claim 1, wherein m represents 100 and n represents zero. 3. A detergent composition comprising the polycarboxylic acid or a salt thereof according to claim 1 and a surfactant.