JP5275588B2 - Polymer builder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer builder having excellent builder performance, improved biodegradation property and mud dispersibility, a method of simply manufacturing the high polymer builder, and a detergent composition containing the polymer builder. <P>SOLUTION: The polymer builder comprises a graft polymer having polyvinyl alcohol as a main chain and a graft chain which contains a polymer unit originating from a monomer having carboxyl group and has number average molecular weight of 150-1,000, wherein weight of the graft chain is 10-80 wt.% of the weight of total polymer. The method of manufacturing the same and a detergent containing the polymer builder and a surfactant are also provided. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a polymer builder composed of a graft polymer, a method for producing the polymer builder, and a cleaning composition containing the polymer builder.

  Synthetic detergents for fibers contain a surfactant as a main component, but a builder that captures calcium in water is blended in order to increase the cleaning ability. As the builder, an inorganic builder such as zeolite A is widely used, and an organic builder is also used to supplement its action.

  Examples of organic builders used in detergents include polycarboxylic acid polymer builders. However, many of them have low biodegradability, and in recent years, replacement with a polymer having good builder performance and improved biodegradability has been attempted from the viewpoint of environmental safety.

  Non-Patent Document 1 discloses a random copolymer of polyvinyl alcohol (PVA) and acrylic acid. However, in such a random copolymer, the acrylic acid unit is divided by polyvinyl alcohol, and the builder performance cannot be increased. On the other hand, when the acrylic acid content is increased in search of the builder performance, the biodegradability is rapidly increased. It is difficult to achieve both biodegradability and builder performance.

Patent Document 1 discloses a builder copolymer obtained by grafting a monomer having a carboxyl group onto a biodegradable backbone such as polyalkylene oxide. However, as a method for producing this copolymer, use of a metal salt for obtaining a builder having a desired structure is described, and a builder having high performance cannot be produced by a simple method.
Macromol.Chem., 194, 3237 (1993) JP-A-3-177406

  An object of the present invention is to provide a polymer builder having good builder performance, improved biodegradability and excellent mud dispersibility, a method for easily producing the polymer builder, and the polymer builder It is to provide a cleaning composition.

  The present invention has a graft chain having a number average molecular weight of 150 to 1000 containing polyvinyl alcohol as a main chain and a polymer unit derived from a monomer having a carboxyl group, and the weight of the graft chain is 10 to 10 of the total polymer weight. There are provided a polymer builder comprising a graft polymer of 80% by weight, a method for producing the polymer builder, and a cleaning composition containing the polymer builder and a surfactant.

  ADVANTAGE OF THE INVENTION According to this invention, the builder performance is favorable, biodegradability is improved, and the polymer builder excellent in mud dispersibility, and the cleaning composition containing the same can be provided.

[Polymer Builder]
The polymer builder of the present invention comprises a graft polymer having a graft chain containing a polymer unit derived from a monomer having a polyvinyl alcohol as a main chain and having a carboxyl group.

  The average degree of polymerization of polyvinyl alcohol is not particularly limited, but is preferably 5000 or less, more preferably 3000 or less, and even more preferably 1000 or less from the viewpoint of aqueous solution viscosity. Moreover, from a biodegradable viewpoint, 50 or more are preferable, 100 or more are more preferable, and 200 or more are further more preferable.

Here, the average degree of polymerization of polyvinyl alcohol can be determined by ¹ H-NMR measurement, and the commercial values used are catalog values.

  Polyvinyl alcohol may be partially or wholly saponified. From the viewpoint of biodegradability, the content of the vinyl alcohol unit in the main chain of the graft polymer is preferably 60% by weight or more, more preferably 80% by weight or more, and further preferably 90% by weight or more.

  The monomer having a carboxyl group constituting the graft chain of the graft polymer of the present invention is at least one selected from acrylic acid, methacrylic acid, maleic acid, itaconic acid, crotonic acid, vinyl acetic acid, and salts thereof. And at least one selected from acrylic acid, methacrylic acid and salts thereof is more preferable. The neutralization degree of the monomer having a carboxyl group is not particularly limited, but is preferably 80% or less, more preferably 50% or less, and further preferably 20% or less.

  Here, the degree of neutralization of the monomer having a carboxyl group is defined as the ratio of the number of equivalents of the basic compound used for neutralization to the number of equivalents of carboxyl groups in the monomer. Examples of basic compounds include alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, and magnesium hydroxide, ammonia, and amine compounds.

  Further, the graft chain can contain an ethylenically unsaturated monomer copolymerizable with a monomer having a carboxyl group. Such monomers include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, alkyl ester of methacrylic acid, etc .; hydroxyalkyl ester of acrylic acid or methacrylic acid; acrylamide, methacrylamide, etc. Is mentioned.

  The content of the monomer having a carboxyl group in the graft chain is preferably 60% by weight or more, more preferably 80% by weight or more, and further preferably 90% by weight or more.

  From the viewpoint of obtaining sufficient biodegradability of the polymer builder of the present invention, the number average molecular weight of the graft chain is 150 or more, preferably 250 or more, and more preferably 500 or more. Moreover, it is 1000 or less, 800 or less are preferable and 750 or less are more preferable.

  The weight of the graft chain in the graft polymer of the present invention is 10% by weight or more, preferably 15% by weight or more, more preferably 20% by weight or more based on the total polymer weight from the viewpoint of developing high builder performance. Moreover, from a viewpoint of obtaining sufficient biodegradability, it is 80 weight% or less, 70 weight% or less is preferable and 50 weight% or less is more preferable.

  In the graft polymer of the present invention, the length of the polyvinyl alcohol main chain between the graft chain and the graft chain is preferably long from the viewpoint of obtaining sufficient biodegradability. The larger the length, that is, the average value of the molecular weight of the main chain existing between the graft chains (hereinafter referred to as the inter-graft point molecular weight), the better the biodegradability, and the inter-graft point molecular weight is preferably 300 or more. 500 or more is more preferable, and 1000 or more is more preferable.

The number average molecular weight of the graft chain, the weight of the graft chain in the graft polymer, and the molecular weight between graft points can be determined by ¹ H-NMR and ¹³ C-NMR measurements.

  The weight average molecular weight of the graft polymer of the present invention is preferably 5000 or more, and more preferably 9000 or more, from the viewpoints of handling properties accompanying increase in viscosity of the aqueous solution and builder performance. Moreover, 200,000 or less is preferable, 150,000 or less is more preferable, and 100,000 or less is further more preferable.

  The weight average molecular weight of the graft polymer can be measured by gel permeation chromatography using polyacrylic acid as a standard polymer.

[Production method of polymer builder]
The polymer builder of the present invention is produced by dropping and polymerizing a monomer component containing a monomer having a carboxyl group and a polymerization initiator into polyvinyl alcohol. A polymerization initiator and a growth terminal radical are chain-transferred to polyvinyl alcohol to generate a radical on the polyvinyl alcohol main chain, and the monomer component including a monomer having a carboxyl group is polymerized by using this as a starting point. A polymer is obtained.

  In addition, after dissolving and dispersing polyvinyl acetate in an organic solvent and polymerizing a monomer component containing a monomer having a carboxyl group as a graft chain, the obtained graft polymer is hydrolyzed to obtain polyvinyl alcohol as a main chain. A graft polymer may be obtained.

  As a polymerization solvent, a solvent in which a monomer having a carboxyl group is dissolved and polyvinyl alcohol is dissolved or dispersed is preferable. High boiling alcohol such as water and octanol, high boiling hydrocarbon such as paraffin, and polyvinyl alcohol are dissolved. N, N-dimethylformamide, dimethyl sulfoxide and the like.

  The polymerization temperature is preferably 90 ° C. or higher, and more preferably 95 ° C. or higher. By adopting such temperature, the chain transfer of the monomer having a carboxyl group to polyvinyl alcohol is sufficiently advanced, the grafting efficiency is improved, and the molecular weight of the graft chain derived from the monomer having a carboxyl group is reduced. As a result, a graft polymer having good biodegradability can be obtained. A higher polymerization temperature is more preferable because the efficiency of chain transfer onto polyvinyl alcohol increases. In the case of producing at a polymerization temperature exceeding 100 ° C., polymerization under high pressure and use of a high boiling point solvent such as dimethyl sulfoxide can be mentioned. Although the upper limit of polymerization temperature is restrict | limited by the boiling point of a solvent, etc., 200 degrees C or less is preferable and 150 degrees C or less is more preferable.

  In order to reduce the molecular weight of the graft chain derived from the monomer having a carboxyl group with high graft efficiency, it is effective to sufficiently increase the dropping time of the monomer. The dropping time of the monomer component containing the monomer having a carboxyl group varies depending on the temperature and the amount of the monomer to be dropped, and is preferably performed for a time equal to or longer than the minimum dropping time Tmin defined by the following formula (1).

Tmin [hr] = 3.95 × 10 ⁻²⁸ × exp (24479 / T) × G / C ^1.5 (1)
[Where, T: polymerization temperature [absolute temperature (K)], G:% by weight of the monomer having a carboxyl group in the total amount of raw material monomers constituting the graft polymer, C: initial concentration (weight) of polyvinyl alcohol %). ]
The minimum dropping time Tmin can be shortened as the polymerization temperature increases, and decreases exponentially with respect to the absolute temperature of the polymerization. Moreover, when it is desired to increase the weight% (G) of the monomer having a carboxyl group in the total amount of raw material monomers constituting the graft polymer, it is necessary to increase Tmin. If the initial concentration (C) of polyvinyl alcohol is high, Tmin may be short. The initial concentration (C) of polyvinyl alcohol is the concentration of an aqueous polyvinyl alcohol solution prepared in advance in a polymerization reaction tank before dropping a monomer having a carboxyl group.

  Although the polymerization time depends on the reaction temperature as described above, it is preferably 2 hours or longer, more preferably 5 hours or longer, and even more preferably 10 hours or longer. Moreover, 24 hours or less are preferable.

  The polymerization initiator is preferably a polymerization initiator soluble in a solvent. As the polymerization initiator, an azo polymerization initiator is preferable because it can suppress the crosslinking reaction even when the graft chain content is increased, and the molecular weight of the graft chain can be prevented from becoming excessively large. However, a conventionally known polymerization initiator other than the azo polymerization initiator can also be used.

  Examples of the azo polymerization initiator used in the present invention include 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 1,1′-azobis (cyclohexane-1-carbonitrile), and 2,2′-azobis. Selected from the group consisting of (2-amidinopropane) dihydrohalide, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrohalide and 4,4′-azobis-4-cyanovaleric acid One or more of these are preferable from the viewpoint of achieving the object of the present invention. In the above polymerization initiator, the halide is preferably chloride from the economical viewpoint.

  Examples of the polymerization initiator other than the azo polymerization initiator used in the present invention include hydroperoxides, hydrogen peroxide, potassium persulfate, persulfates such as ammonium persulfate, ammonium persulfate, potassium perchlorate, Perchlorates such as sodium chlorate, halogenates such as potassium chlorate and potassium bromate, hydrogen peroxide / ferrous salt, persulfate / sulfite, cumene hydroperoxide / ferrous salt, perchlorate Examples thereof include redox polymerization initiators such as hydrogen oxide / L-ascorbic acid. These can use 1 or more types.

[Cleaning composition]
The cleaning composition of the present invention contains the polymer builder of the present invention and a surfactant. The content of the polymer builder of the present invention in the cleaning composition of the present invention is preferably 0.1 to 15% by weight and more preferably 1.5 to 10% by weight from the viewpoint of cleaning performance. The content of the surfactant is preferably 10 to 40% by weight and more preferably 20 to 30% by weight from the viewpoint of cleaning performance.

  The polymer builder of the present invention may be used alone as a detergent builder, but may be used in combination with inorganic builders such as zeolite A and other organic builders.

  The surfactant used with the polymer builder of the present invention may be any of an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  Examples of the anionic surfactant include fatty acid soaps, alkyl ether carboxylates, N-acyl amino acid salts, alkylbenzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, α-olefin sulfonates. Higher alcohol sulfates, alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, fatty acid alkylolamide sulfates, alkyl ether phosphates, alkyl phosphates and the like are preferably used.

  As the cationic surfactant, aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts and the like are preferably used.

  Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene Castor oil, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyethylene glycol fatty acid ester, fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester, fatty acid alkanolamide, polyoxyethylene fatty acid amide, polyoxyethylene alkylamine, Alkylamine oxide and the like are preferably used.

  As the amphoteric surfactant, for example, carboxybetaine type compounds, aminocarboxylates, imidazolinium betaines and the like are preferably used.

  When producing the detergent composition of the present invention, in addition to the polymer builder and surfactant of the present invention, enzymes, fluorescent whitening agents, antifoaming agents, etc. used in ordinary detergent compositions Can be blended.

  In the following examples, the weight average molecular weight of the graft polymer was measured by the following method, and the structure was identified by the following method.

<Measurement method of weight average molecular weight>
The weight average molecular weight was measured using gel permeation chromatography. The measurement conditions are as follows.
Column: Tosoh G4000PWXL + G2500PWXL
Eluent: 0.2M phosphate buffer / acetonitrile = 9/1 (vol / vol)
Measurement temperature: 40 ° C
Flow rate: 1.0 mL / min
Detector: UV or RI
Standard polymer: Polyacrylic acid <Method for identifying structure of graft polymer>
The weight fraction G ′ of the monomer unit having a carboxyl group in the total amount of the graft polymer, the number average molecular weight Mn (PAA) of the graft chain, and the molecular weight between graft points are from the peaks of ¹ H-NMR and ¹³ C-NMR. Can be sought. For example, when the monomer having a carboxyl group is acrylic acid, it is determined as follows.

The hydrogen atoms in the graft polymer are divided as follows, the absorption integral value in ¹ H-NMR is defined as a to d, and the sum of the integral values of peaks a, c, and d is defined as x. The approximate chemical shift of each hydrogen atom is shown in parentheses.
a: Methylene hydrogen of polyvinyl alcohol b: Hydrogen bonded to carbon to which a hydroxyl group of polyvinyl alcohol is bonded (3.6 to 4.2 ppm)
c: Methylene hydrogen of acrylic acid d: Hydrogen bonded to carbon to which the carboxyl group of acrylic acid is bonded x: a + c + d (1.0 to 2.4 ppm)
At this time, the number of polyvinyl alcohol units nPVA and the number of acrylic acid units nPAA are represented by the following formulas (2) and (3).

nPVA = b (2)
nPAA = (x-2) / 3 (3)
From the molecular weight 44 of vinyl alcohol and the molecular weight 72 of acrylic acid, the content G ′ of acrylic acid graft chains can be obtained by the formula (4).

G ′ = nPAA × 72 / (nPAA × 72 + nPVA × 44) (4)
Further, the absorption integral values in ¹³ C-NMR of the following carbon atoms in the graft polymer are defined as e and f. The approximate chemical shift of each carbon atom is shown in parentheses.
e: Carbon (about 78 ppm) to which the hydroxyl group of polyvinyl alcohol and the graft chain are bonded
f: Carbon of the carboxyl group of acrylic acid (182-190 ppm)
At this time, the number average molecular weight Mn (PAA) of the graft chain is obtained by the formula (5).

Mn (PAA) = (f / e) × 72 (5)
Moreover, the molecular weight between graft points is calculated | required by Formula (6).

Graft point molecular weight = Mn (PAA) / [(nPAA × 72) / (nPVA × 44)] (6)
Example 1
Polyvinyl alcohol (average polymerization degree = 500, complete saponification (manufactured by Wako Pure Chemical Industries, Ltd.), hereinafter referred to as PVA-1) 70 g and ion-exchanged water 779.8 g were charged into a 2 L separable flask, heated to 100 ° C. The alcohol was dissolved. While maintaining the temperature at 100 ° C., a mixture of 43.78 g of 80% acrylic acid (manufactured by Toagosei Co., Ltd.) and 60.2 g of ion-exchanged water and a polymerization initiator (2,2′-azobis (2-methylpropionamidine) ) Dihydrochloric acid: V-50 manufactured by Wako Pure Chemical Industries, Ltd. A polymerization initiator aqueous solution in which 6.58 g was dissolved in 102 g of ion-exchanged water was added dropwise at a constant rate over 20 hours.

A part of the reaction solution was poured into acetone, re-precipitation was performed, and the precipitate was collected to obtain a graft polymer. ^The precipitate was confirmed to be a graft polymer by ¹ H-NMR. Table 1 shows the weight average molecular weight, the graft amount, the number average molecular weight of the graft chain polyacrylic acid, and the molecular weight between graft points of the obtained graft polymer.

Examples 2-4
As polyvinyl alcohol, PVA-2 obtained by the following method was used in place of PVA-1, and the polymerization initiator shown in Table 1 was used. In the same manner as in Example 1, except for the conditions shown in Table 1. A graft polymer was produced. Table 1 shows the weight average molecular weight, the graft amount, the number average molecular weight of the graft chain polyacrylic acid, and the molecular weight between graft points of the obtained graft polymer.

<Method for producing PVA-2>
A 2 L separable flask is charged with 800 g of methanol, heated to 60 ° C., and then charged with 400 g of vinyl acetate and 2-mercaptoethanol. A polymerization initiator (2,2′-azobis (2,4-dimethylvaleronitrile): A polymerization initiator solution prepared by dissolving (manufactured by Koyo Pure Chemical Co., Ltd.) in 200 g of methanol was added dropwise over 2 hours to carry out polymerization. After completion of the dropping, polymerization was advanced while maintaining the temperature at 60 ° C for 3 hours. After completion of the polymerization, the reaction solution was cooled to 30 ° C., 94.8 g of 3.5% aqueous sodium hydroxide solution was added in two portions, and hydrolysis was performed at room temperature for 2 hours. The precipitated polymer was filtered, washed with methanol, and dried to obtain PVA-2. The average degree of polymerization was 270 (measured by ¹ H-NMR).

Comparative Example 1
The reagent polyvinyl alcohol (manufactured by Wako Pure Chemicals; average polymerization degree = 500) was used as the polymer of Comparative Example 1.

Comparative Example 2
A commercially available sodium polyacrylic acid (PAA) (manufactured by BASF Corp., Socaran PA-15) was used as the polymer of Comparative Example 2. The number average molecular weight of this polymer was 1150 (weight average molecular weight 2370).

  About the polymer builder which consists of the graft polymer obtained in Examples 1-4 and the polymer of Comparative Examples 1-2, mud dispersibility, Ca capture | capture ability, and biodegradability were evaluated with the following method. The results are summarized in Table 1.

<Mud dispersibility>
0.05 g of polymer was accurately weighed into a 100 mL volumetric flask and dissolved in 20 mM ammonium chloride buffer solution (pH 10) (polymer solution). 50 mL of 20 mM ammonium chloride buffer solution (pH 10) was placed in a 50 mL graduated settling tube, 0.5 mL of the polymer solution was added, and the settling tube was capped and shaken. In this, 0.05 g of gardening soil was added, dispersed with shaking for 5 minutes and ultrasonic waves for 5 minutes, and allowed to stand at 25 ° C. for 2 hours. Two hours later, 3 mL was sampled from the 40 mL scale of the sedimentation tube, and the absorbance at 575 nm was measured. The higher the absorbance, the better the mud dispersibility.

<Ca capturing ability>
Ca capturing ability was measured by an ion electrode method using an ion meter and a calcium electrode. 0.1 g of polymer was accurately weighed into a 100 mL volumetric flask and diluted with an ammonium chloride buffer solution (ammonium chloride = 8.558 g / L aqueous solution adjusted to pH 10 with 25% aqueous ammonia). 0.2 ml of calcium chloride aqueous solution (pH 10: prepared with a buffer solution) corresponding to 20000 mg / L (calcium carbonate equivalent) was added dropwise thereto, and the potential difference was measured with a calcium electrode. The calcium ion concentration in the solution was estimated from the relationship between the titration amount and the potential difference, and the calcium scavenging ability (mgCaCO ₃ / g) was calculated from the difference between the calcium ion concentration in the solution and the calcium ion concentration in the blank. In addition, it can be said that the thing of 30 or more Ca capture | acquisition ability has favorable builder performance.

<Biodegradability>
A 3 L beaker was charged with a polymer of 50 mg-carbon / L (approximately 100 mg / L) and a treatment site sludge of 200 mg / L, and the test was conducted at 25 ± 1 ° C. while bubbling and stirring air. On the 28th day from the start of the test, a sample was collected and filtered through a 0.2 μm filter, and the dissolved organic carbon concentration (DOC) was measured. The biodegradation rate was determined by the ratio with the DOC at the start of the test.

The abbreviations in the table have the following meanings.
AA: acrylic acid PVA: polyvinyl alcohol PAA: polyacrylic acid V-50: 2,2′-azobis (2-methylpropionamidine) dihydrochloride V-40: 1,1′-azobis (cyclohexane-1-carbonitrile)
DMSO: Dimethyl sulfoxide
Tmin: Minimum dropping time G: Weight% of acrylic acid in the total amount of raw material monomers constituting the graft polymer
C: Initial concentration (% by weight) of polyvinyl alcohol
G ′: weight fraction of PAA in the total amount of graft polymer Mn (PAA): number average molecular weight of PAA (graft chain).

  From the results in Table 1, it can be seen that the polymer builder of the present invention has good builder performance, improved biodegradability, and excellent mud dispersibility.

Example 5 and Comparative Example 3
A cleaning composition having the composition shown in Table 2 was prepared using the polymer builder composed of the graft polymer obtained in Example 4. Further, a comparative cleaning composition was prepared in the same manner except that the polymer builder was omitted. About the obtained cleaning composition, the washability and recontamination prevention property were evaluated by the following method. The results are shown in Table 2.

<Evaluation method for detergency>
Matsushita Electric Industrial Washing Machine "Aizuma No. NA-F70AP" Apparel (underwear and Y-shirt 8/2 weight ratio) 2.2kg and 10cm x 10cm artificial soiled cloth 10cm prepared by the following method 35cm x 30cm Each sample was sewed on three cotton cloths and placed uniformly, and the evaluation sample 22g was placed on the clothing in a gathered state, poured into the evaluation sample so that it was not directly exposed to water, and washed in a standard course. The washing conditions were as follows.

Cleaning course: Standard course, cleaning agent concentration 0.067% by weight, washing water 71.2 mg CaCO ₃ / L, Ca / Mg molar ratio 7/3 hard water, water temperature 20 ° C., bath ratio 15 L / kg.

  The detergency was measured by measuring the reflectance at 550 nm of the raw cloth before contamination and the contaminated cloth before and after washing with a self-recording colorimeter (manufactured by Shimadzu Corporation), and obtaining the washing rate according to the following formula: Values are given as detergency. The reflectance after washing is A, the reflectance before washing is B, and the reflectance of the raw cloth is C.

Cleaning rate (%) = (A−B) / (C−B) La 100
-Preparation of artificially contaminated cloth As the pollutant, oleic acid 28.3% by weight, triolein 15.6% by weight, cholesterol oleate 12.2% by weight, liquid paraffin 2.5% by weight, squalene 2.5% by weight, An artificial contamination solution consisting of an aqueous solution containing 2.5% by weight of cholesterol, 7.0% by weight of gelatin, 29.8% by weight of inorganic dirt, and 0.5% by weight of carbon black (designated by Japan Oil Chemical Association) is attached to the cloth. To prepare an artificially contaminated cloth. The artificial contamination liquid was attached to the cloth by printing the artificial contamination liquid on the cloth according to Japanese Patent Application Laid-Open No. 7-270395. The process of producing an artificially contaminated cloth by attaching an artificially contaminated liquid to the cloth was performed at a cell volume of gravure roll of 58 cm ³ / cm ² , a coating speed of 1.0 m / min, a drying temperature of 100 ° C., and a drying time of 1 minute. The cloth used was a cotton gold cloth 2003 cloth (manufactured by Yagami Shoten).

<Evaluation method for recontamination prevention>
A white cotton cloth (gold cloth 2003 cloth) was cut into 10 cm × 10 cm to form a set of five sheets. Gardening kanuma red soil was added to 1 L of the cleaning aqueous solution for evaluation, and a cleaning test was performed with a targotometer under the following conditions. The washing conditions are washing time: 10 minutes, detergent concentration: 0.08% by weight, water hardness: 4−, water temperature: 20 ° C., rinse: 20 ° C. tap water for 5 minutes in tap water.

  The anti-recontamination property was determined by measuring the reflectance at 460 nm of the raw cloth (white cloth) before washing and the contaminated cloth after the test with a self-recording colorimeter (manufactured by Shimadzu Corporation), and obtaining the re-contamination prevention ratio by the following formula.

  Prevention of recontamination (%) = (reflectance after test / reflectance of raw fabric) × 100

* 1: A-type zeolite (Zeobuilder)
* 2: Emulgen 108 (manufactured by Kao Corporation)
* 3: Molecular weight 8500

Claims (6)

It has a graft chain having a number average molecular weight of 150 to 750 containing a polymer unit derived from a monomer having a carboxyl group as a main chain, and the weight of the graft chain is 10 to 80% by weight of the total polymer weight. A polymer builder consisting of a graft polymer.   The polymer builder according to claim 1, wherein the monomer having a carboxyl group is at least one selected from acrylic acid, methacrylic acid and salts thereof.   The polymer builder according to claim 1 or 2, wherein the graft polymer has a weight average molecular weight of 5,000 to 200,000. The polymer builder according to any one of claims 1 to 3, wherein the graft polymer has a molecular weight between graft points of 300 or more. In a temperature range of 90 to 200 ° C., a monomer component containing a monomer having a carboxyl group and a polymerization initiator are added to polyvinyl alcohol over a minimum dropping time Tmin defined by the following formula (1). to carry out the polymerization method for producing a polymer builder according to any one of claims 1-4.
Tmin [hr] = 3.95 × 10 ⁻²⁸ × exp (24479 / T) × G / C ^1.5 (1)
[Where, T: polymerization temperature [absolute temperature (K)], G:% by weight of the monomer having a carboxyl group in the total amount of raw material monomers constituting the graft polymer, C: initial concentration (weight) of polyvinyl alcohol %). ] A cleaning composition comprising the polymer builder and a surfactant according to any one of claims 1 to 4 .