JPH0749450B2 - Process for producing acid-type maleic acid polymer, water treatment agent containing the polymer, and detergent additive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention is useful as a water treatment agent, a detergent builder, various chelating agents, etc., and is an acid-type polymaleic acid having an acrylic acid structural unit in the molecule and an acid-type maleic acid. Regarding a method for producing an acid-based copolymer and its use, in detail, an acid-type polymaleic acid or an acid-type maleic acid-based copolymer having excellent quality can be efficiently and economically produced by using a specific polymerization catalyst with water as a solvent. And a water treatment agent and a detergent additive comprising the produced polymer. Particularly, according to the method of the present invention, it is possible to produce a high-quality acid-type polymaleic acid and acid-type maleic acid-based copolymer having a narrow molecular weight distribution and a low molecular weight.

<Prior Art> Conventionally, maleic acid (co) polymers and the like have been used in fields such as water treatment agents and detergents, dispersants, and various chelating agents. Known literatures relating to a method for producing such a maleic acid (co) polymer include, for example, JP-A-57-1689.
06 (USP4519920, USP4555557) JP 59-64613, JP 5
9-64615 (USP4668735), JP-A-59-176312, (USP4589)
995), JP-A-59-210913 (USP4668735), JP-A-59-2.
13714, JP60-212410, JP61-178097, JP62-
218407 (USP4659793), JP-A-63-114986, JP-A-63-1
35313, JP-A-63-236600, JP-B-56-54005 and the like.

However, all of the maleic acid-based (co) polymers obtained by these methods have too high a molecular weight, and /
Or, because the molecular weight distribution is too wide, when used as a water treatment agent such as a scale inhibitor, it tends to cause gelation due to the complexing action with cations such as Ca ions in water, which is insufficient in performance. It had drawbacks. Therefore, a maleic acid (co) polymer having a low molecular weight and a narrow molecular weight distribution has been demanded.

Further, the maleic acid-based (co) polymers obtained by these production methods are all salt-type maleic acid-based (co) polymers such as ammonium salt, sodium salt, potassium salt, etc. When used as a detergent additive, there is a problem that compatibility with a nonionic surfactant is poor, it is difficult to produce a stable liquid detergent composition, and its use is significantly limited. Further, as a water treatment agent, a composition in which a maleic acid-based (co) polymer and zinc are used in combination to form a one-part composition is required, but a salt-type maleic acid-based (co) polymer is converted into an acid form. Such compositions were difficult to manufacture due to their poor compatibility with zinc.

Further, JP-A-60-212411 (USP4709091) and JP-A-60-
212412 discloses a method for producing a maleic acid-based (co) polymer having a narrow molecular weight distribution. However, since the polymerization is carried out with two stages of neutralization degree of these methods, the polymerization time is However, there is a drawback that the process becomes complicated and the process becomes complicated. Further, since persulfate is used as the catalyst, there is a possibility that the reaction vessel such as SUS304 may be corroded. Moreover, the maleic acid-based (co) polymer obtained by this method is of a salt type and, like the above, is inferior in performance as a detergent additive or a water treatment agent. On the other hand, the acid-type maleic acid-based (co) polymer does not have the above-mentioned drawbacks found in the salt-type maleic acid-based (co) polymer, and is used as a water treatment agent or a detergent additive. Exhibits excellent characteristics. Such an acid-type maleic acid-based (co) polymer can also be produced by removing an alkali metal ion from the above salt-type maleic acid-based (co) polymer, but the production process is complicated and the cost is low. This is not a preferable method because it causes an increase. Moreover, the essential drawback of high molecular weight and wide molecular weight distribution cannot be improved at all. On the other hand, JP-A-51-19089 and JP-B-57-57482 (USP3919
258), JP-B-62-36042 (USP4212788) and the like, maleic anhydride alone or maleic anhydride and another polymerizable monomer are dissolved in an organic solvent such as toluene or xylene to give benzoyl peroxide, Azobisisobutyronitrile,
A method of producing an acid-type maleic acid (co) polymer by (co) polymerizing with an oil-soluble polymerization initiator such as ditertiary butyl peroxide, distilling off the solvent, and then hydrolyzing with water is used. Are known. However, these production methods are not advantageous in terms of disaster prevention, cost, and resource saving as well as the number of steps because polymerization is carried out in an organic solvent.

Further, the polymer terminal group of the maleic acid-based (co) polymer obtained by the above method is a group having extremely strong hydrophobicity such as an aromatic hydrocarbon residue derived from the polymerization solvent or a tertiary butyl group derived from the polymerization initiator. For example, when used as a scale inhibitor, it is likely to combine with alkaline earth metal ions such as Ca ions and Mg ions in the water to be treated to form an insoluble salt. As a result, there is a problem that the scale prevention effect becomes insufficient. Further, JP-A-62-91295 and JP-A-62-91296 (GB218173
For 5), a salt-type maleic acid-based (co) polymer obtained by using a mixed solvent of water and an alcohol and / or a ketone as a polymerization solvent, adding FeSO ₄ and using hydrogen peroxide as a polymerization catalyst. It is disclosed that coalescence is effective as a scale control agent. However, the method disclosed here has extremely poor copolymerizability, and for example, when acrylic acid is copolymerized, an acrylic acid structure can be introduced evenly into the main chain of the resulting polymer. However, when used at high temperature, depolymerization is likely to occur and only a polymer having a wide molecular weight distribution can be obtained. In addition, there are many problems that there are many residual monomers. Further, when a high-boiling solvent such as methyl ethyl ketone is used, the solvent tends to remain in the obtained product, which causes problems in terms of odor and safety. Furthermore, the effect as a water treatment agent and a detergent additive was not sufficient.

Further, JP-A-57-126810, JP-A-58-122906, JP-A-58-
147412, JP-A-62-68806 propose a method and / or use of a maleic acid-based copolymer. However, in the production methods described in JP-A-57-126810 and JP-A-58-122906, the copolymer obtained has a wide molecular weight distribution, a large amount of residual monomer, and further lacks biodegradability. There is a problem. On the other hand, JP-A-58-147412 and JP-A-62-
The maleic acid-based copolymer obtained by the production method described in 68806 has a problem in terms of biodegradability.

Further, in USP-4314044 and USP-3635915, a redox-based polymerization catalyst in which a polyvalent metal ion such as Fe ²⁺ is used as a reducing agent and a peroxide is combined is not compatible with an unsaturated dicarboxylic acid (for example, maleic acid). It is described that it effectively acts on the copolymerization of a saturated monocarboxylic acid (eg acrylic acid).

However, in the above-mentioned redox-based polymerization, 1/150 to 1/10 per 1 mol of the peroxide is used for proceeding the redox reaction between the peroxide used as the initiator and the polyvalent metal ion used as the reducing agent. It is necessary to use moles of polyvalent metal ions, especially Fe ²⁺ , and as a result, problems such as contamination and coloring of products due to polyvalent metal ions occur. In addition, the polymerization with a redox-based catalyst yielded only a maleic acid-based copolymer having a wide molecular weight distribution, and its performance when used as a water treatment agent or a detergent was insufficient.

Further, in JP-A-62-218407 (USP4659793), a copolymer is produced by reacting an at least partially neutralized monoethylenically unsaturated dicarboxylic acid with an α, β-ethylenically unsaturated monomer. At the same time, a method for producing an aqueous solution of a dicarboxylic acid copolymer is disclosed in which the reaction is carried out in the presence of a water-soluble polymerization initiator and a polyvalent metal ion while maintaining the pH of the aqueous solution system at about 2 to 7.

However, the copolymer obtained by this method is also a salt-type maleic acid-based copolymer as described above, which has the advantage that the amount of unreacted monomer is small, but the compatibility with the nonionic surfactant and Zn. The problem of poor compatibility with is still unsolved, and when an alkali metal salt is removed to produce an acid-type maleic acid-based copolymer, problems such as a complicated production process and an increase in production cost occur.

In addition, as a method for producing a polymer in which a polymerization initiator and a polyvalent metal ion are used to proceed a polymerization reaction, JP-A-62-
62804 (USP4786699) and JP-A-62-267307 (EP24279).
1) is mentioned. However, these relate to the production method of polyvinylpyrrolidone or polyallylamine, respectively.

<Problems to be Solved by the Invention> The present invention has been made to solve the above-mentioned problems of the prior art, and is useful as a water treatment agent, a detergent additive, or the like. A maleic acid-based copolymer, in particular, a low molecular weight and a narrow molecular weight distribution of acid type polymaleic acid and maleic acid-based copolymer, an object of which is to provide a method for economically producing by a simple process, Further, the present invention intends to supply to the market an inexpensive water treatment agent or detergent additive having excellent performance by utilizing the acid type polymaleic acid and the acid type maleic acid type copolymer obtained by this method. In the following description, the acid-type polymaleic acid and the acid-type maleic acid-based copolymer may be collectively referred to as an acid-type maleic acid-based polymer.

<Means for Solving the Problems> However, the method of the present invention which has achieved the above-mentioned object, is a monomer component consisting of maleic acid (A) only, or maleic acid (A) 50 to 99.9% (meaning% by weight, The same shall apply hereinafter)
Another water-soluble unsaturated monomer (B) 50-0.1% monomer component is selected from the group consisting of iron ion, vanadium atom-containing ion, and copper ion with respect to the monomer component.
Polymerization in the presence of 0.5 to 500 ppm of at least one type of metal ion using 8 to 100 g of hydrogen peroxide per mole of monomer as a polymerization catalyst, acid type having a number average molecular weight of 300 to 5000 and a D value of 2.5 or less. The present invention relates to a method for producing an acid-type maleic acid polymer, which comprises obtaining a maleic acid polymer. It also relates to a water treatment agent or detergent additive containing the acid-type maleic acid polymer obtained by the above method.

D value = MW / MN MW: weight average molecular weight MN: number average molecular weight That is, in the method of the present invention, if a monomer component consisting of maleic acid (A) alone is used as a polymerization raw material, acid type polymaleic acid (homopolymer) is obtained. And a maleic acid (A) and another water-soluble unsaturated monomer (B) are used as polymerization raw materials, an acid-type maleic acid-based copolymer can be obtained. In any case, it is necessary to use water alone as a polymerization solvent, and in the case of using a hydrophilic solvent such as an alcohol or a ketone, or a mixed solvent of these hydrophilic solvent and water, the homopolymer is polymerized. In that case, an acid-type polymaleic acid having an acrylic acid structure in the main chain cannot be obtained, and when polymerizing the copolymer, the maleic acid (A) and the water-soluble monomer (B) are uniformly copolymerized. Cannot be polymerized. Moreover, the residual amount of unreacted monomer is significantly increased. On the other hand, in the method of the present invention, water alone is used as the polymerization solvent and specific polymerization conditions are adopted, whereby the polymerization reaction of the acid-type monomer can efficiently proceed. Further, a polymer having a polymer end group different from the conventional maleic acid (co) polymer can be produced, and a maleic acid copolymer having excellent performance as a water treatment agent or a cleaning additive can be obtained. In addition, the method of the present invention has a narrow molecular weight distribution and makes it possible to obtain a low molecular weight polymer, which greatly contributes to enhancing the performance as a water treatment agent or a detergent additive.

Incidentally, most of the conventional techniques use salt-type maleic acid as a raw material, because the polymerization reaction of acid-type maleic acid in an aqueous solvent is difficult to proceed and it has been difficult to efficiently produce a polymer. On the other hand, the method of the present invention succeeds in polymerizing the acid-type maleic acid without changing it to the salt-type by devising the polymerization conditions, and has a narrow molecular weight distribution and is highly reactive with the polymer end groups. That is, it succeeded in obtaining a polymer excellent in performance as a water treatment agent or the like. Further, since the acid type maleic acid type polymer can be directly obtained, the process is simple,
In addition, since the amount of metal ions used is small, it is possible to obtain a high-quality polymer with a low degree of contamination.

In the production method of the present invention, the other water-soluble unsaturated monomer (B) used as a copolymerization component of maleic acid (A) when producing a copolymer is not particularly limited,
For example, unsaturated monocarboxylic acid type monomers such as acrylic acid, methacrylic acid, α-hydroxyacrylic acid and crotonic acid; unsaturated polycarboxylic acid type monomers such as fumaric acid, itaconic acid, citraconic acid and aconitic acid. Vinyl acetate; general formula (1) (In the formula, R ¹ and R ² each independently represent hydrogen or a methyl group, and R ¹ and R ² do not simultaneously represent a methyl group, and R ³ is —CH ₂ —, — (CH ₂ ) ₂ - or -C (CH _{3) 2}
Represents a total number of carbon atoms in R ¹ , R ² and R ³ , Y represents an alkylene group having 2 to 3 carbon atoms, and n is 0.
Alternatively, it is an integer of 1 to 100. ), For example, 3-
Methyl-3-buten-1-ol (isoprenol), 3
-Methyl-2-buten-1-ol (prenol), 2-
Unsaturated hydroxyl group-containing monomers such as methyl-3-buten-2-ol (isoprene alcohol) and monomers obtained by adding 1 to 100 mol of ethylene oxide and / or propylene oxide to 1 mol of these monomers; General formula (2) (Wherein R ¹ represents hydrogen or a methyl group, a, b, d and f each independently represent 0 or an integer of 1 to 100, and a + b + d + f = 0 to 100, and an —OC ₂ H ₄ unit And -OC ₃ H ₆ -units may be combined in any order,
When d + f is 0, Z represents a hydroxyl group, a sulfonic acid group and a (phosphite) group, and when d + f is a positive integer of 1 to 100, Z represents a hydroxyl group. ),
For example, 3-allyloxy-2-hydroxypropanesulfonic acid, glycerol monoallyl ether, and unsaturated (meth) monomers such as ethylene oxide and / or propylene oxide added in an amount of 1 to 100 mol per mol of these monomers. Allyl ether type monomers; vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, 2- Unsaturated sulfonic acid group-containing monomer such as hydroxysulfopropyl (meth) acrylate and sulfoethylmaleimide; an alcohol obtained by adding 0 to 100 mol of ethylene oxide and / or propylene oxide to an alkyl alcohol having 1 to 20 carbon atoms (meth )acrylic , Crotonic acid, maleic acid,
Mono- or diesters with fumaric acid, itaconic acid, citraconic acid, aconitic acid, etc., or (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, aconitic acid, etc. Examples thereof include ester unsaturated monomers such as mono- or diester-based monomers in which 1 to 100 mol of ethylene oxide and / or propylene oxide is added to the monomer, and 1 selected from these groups. Seed or 2
More than one species can be used.

As a suitable water-soluble monomer (B) when used as a water treatment agent or a detergent additive, an unsaturated monocarboxylic acid type monomer (acrylic acid and methacrylic acid are particularly preferable), the above-mentioned general formula (1) ), An unsaturated alcohol monomer represented by the formula (especially isoprenol and polyethylene glycol monoisoprenol ether are preferable), and an unsaturated allyl ether monomer represented by the general formula (2) (especially glycerol monoene). Allyl ether, 3-
(Aryloxy-2-hydroxypropanesulfonic acid is particularly preferable).

The ratio of maleic acid (A) and water-soluble monomer (B) used must be in the range of 50 to 99.9% for the former and 50 to 0.1% for the latter, preferably 75 to 99.9% for the former and 25 to 0.1% for the latter. It is desirable to set the range. When the water-soluble monomer (B) is used in an amount of more than 50%, the amount of residual monomer increases, resulting in insufficient performance as a detergent additive. Furthermore, there is a problem with biodegradability.

Incidentally, it is natural that maleic anhydride can be used in place of maleic acid (A) in the present invention because maleic anhydride reacts with water to form maleic acid very easily.

Next, examples of the metal ions used in the present invention include iron ions, vanadium atom-containing ions, and copper ions. Among them, Fe ³⁺ , Fe ²⁺ , Cu ⁺ , Cu ²⁺ , V ²⁺ , V ^3+, VO ^2+, VO ₃ ^-
Is preferred. Particularly preferred metal ions are Fe ³⁺ , Cu ²⁺ , VO ²⁺
And one or more selected from the group of these metal ions can be used. Metal ions
It is necessary to use it in the range of 0.5 to 500 ppm, preferably 5 to 100 ppm, relative to the monomer component.
When the amount of metal ions is less than this range, the polymerization rate or copolymerization rate is not improved. Further, when the metal ion is used in a larger amount than this range, it not only pollutes the product and causes a coloring problem, but also the molecular weight distribution of the acid-type polymaleic acid or the acid-type maleic acid-based copolymer produced is broadened. , The performance as a water treatment agent and a detergent additive is deteriorated, and the biodegradability is also low.

The form of metal ion supply is not particularly limited, and the point is that it can be used as long as it is ionized in the polymerization reaction system. Examples of such a metal compound include vanadium oxytrichloride, vanadium trichloride, vanadyl oxalate, vanadyl sulfate, vanadic anhydride, ammonium metavanadate, ammonium sulfate hypovanadas [(NH ₄ ) ₂ SO ₄ · VSO ₄ · 6H ₂ O], ammonium sulfate vanadas [(NH ₄ ) V (SO ₄ ) ₂ · 12H ₂ O], copper acetate (I
I), copper (II) bromide, copper (II) acetyl acetate, cupric ammonium chloride, copper carbonate, copper (II) chloride, copper (II) citrate, copper (II) formate, copper hydroxide (II) ), Copper nitrate,
Copper naphthenate, copper oleate, copper maleate, copper phosphate, copper (II) sulfate, cuprous chloride, copper (I) cyanide, copper iodide, copper (I) oxide, copper thiocyanate, iron acetyl Acetonate, ammonium iron citrate, ferric ammonium oxalate, ferrous ammonium sulfate, ferric ammonium sulfate, iron citrate, iron fumarate, iron maleate,
Water-soluble metal salts such as ferrous lactate, ferric nitrate, iron pentacarbonyl, ferric phosphate, ferric pyrophosphate; vanadium pentoxide, copper (II) oxide, ferrous oxide, ferric oxide Examples thereof include metal oxides such as iron; metal sulfides such as copper (II) oxide and iron sulfide; and other copper powder and iron powder.

Further, in order to adjust the concentration of metal ions, for example, condensed phosphoric acid system such as pyrophosphoric acid, hexametaphosphoric acid, tripolyphosphoric acid: aminocarboxylic acid system such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid: 1-hydroxyethylidene-1 , 1-diphosphonic acid, 2
-Phosphonobutane-1,2,4-tricarboxylic acid and other phosphonic acid system: fumaric acid, malic acid, citric acid, itaconic acid, oxalic acid, crotonic acid and other organic acid system: polyacrylic acid and other polycarboxylic acid system It is also possible to use the complex-forming agent of 1) together with the above metal ion.

The polymerization temperature is preferably in the range of 50 to 160 ° C, more preferably 70 to 160 ° C for the purpose of shortening the polymerization time. More preferably
85-150 ° C. Below 50 ° C, the progress of polymerization may be hindered. On the other hand, if it exceeds 160 ° C, a thermal decomposition reaction is expected. The solid content at the time of polymerization can be carried out in a wide range, but 30 to 99%, more preferably 40 to
The range of 95% is preferable because the residual maleic acid can be further reduced.

In the production method of the present invention, the polymerization reaction proceeds by the supply of hydrogen peroxide which is a polymerization catalyst. At that time, it is considered that depolymerization of maleic acid and / or acid type maleic acid-based polymer in the reaction system causes degassing acid. Generation of carbon dioxide is recognized. The amount of carbon dioxide gas generated by decarboxylation during the polymerization reaction is proportional to the amount of hydrogen peroxide added. Therefore, the decarboxylation amount can be controlled by adjusting the input amount of hydrogen peroxide, and as a result, the amount of carboxyl groups in the acid-type maleic acid-based polymer can be arbitrarily controlled.
The amount of the carboxyl group greatly changes the physical properties and performance of the polymer, and by controlling this, the acid-type maleic acid polymer of the present invention has a great advantage that it can be applied to a wider range of applications. The amount of hydrogen peroxide used in the present invention is required to be 8 to 100 g per 1 mol of the monomer component, and more preferable range is 10 to 80 g per 1 mol of the monomer component, and the most preferable range. Is 15-50g
Is. When the amount of hydrogen peroxide is less than 8g, the amount of residual maleic acid increases. On the contrary, even if more than 100 g is used, not only the effect corresponding to the increase of hydrogen peroxide is not obtained, but
Causes the problem of residual hydrogen peroxide.

In the present invention, a polymerization catalyst other than hydrogen peroxide, for example, persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate: 2,2′-azobis (2-amidinopropane) hydrochloride, 4,4′-azobis-4 -Cyanovaleric acid, azobisisobutyronitrile, azo compounds such as 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, peracetic acid, persuccinic acid, When an organic peroxide such as ditertiary butyl peroxide, tert-butyl hydroperoxide or cumene hydroperoxide is used, a high-quality acid-type polymaleic acid and acid having a narrow molecular weight distribution and a low molecular weight as in the present invention are used. Not only is a maleic acid type copolymer not obtained, but the amount of residual monomers is extremely large.

The method of supplying hydrogen peroxide into the polymerization system is not particularly limited, and for example, initial batch charging may be performed in the reaction system, or continuous charging may be performed during the reaction. Depending on the case, it is also possible to divide it and put it in batch. However, in order to allow the polymerization reaction to proceed more smoothly, it is preferable to carry out continuous charging, and it is more preferable to carry out continuous charging a plurality of times with a temporary suspension period of charging. However, the most preferred embodiment is a method of continuously charging for a certain period of time, temporarily stopping the charging, and then continuously charging for a certain period of time again. If such a method of supplying hydrogen peroxide is adopted, The unreacted residual monomer can be significantly reduced. At this time, the time, the time, the number of times and the temperature at which the hydrogen peroxide is temporarily stopped are not particularly limited, and should be appropriately determined according to the supply state of the monomer component. Is 10 to 160 minutes, preferably 30 to 120 minutes, the number of stops is 1 to 3 times, and the temperature during the stop period is 50 to 160 ° C., preferably 8
The temperature is 5 to 160 ° C, more preferably 100 to 150 ° C. The continuous feeding time before and after the temporary stop is 10 to 200 minutes, preferably 20 to 120 minutes.

By the way, in the above-mentioned JP-A-62-218407 (USP-4659793), a polymerization catalyst having a combination of iron-hydrogen peroxide is disclosed, for example, in a maleic acid / acrylic acid copolymer salt (polymerization ratio of 10 to 70).
/ 90 to 30), there is a description that it is effective in reducing residual maleic acid. However, in the above-mentioned prior art documents, in order to reduce the amount of residual monomer, the pH during polymerization must be maintained at 2 to 7, and as the ratio of maleic acid increases, the pH during reaction must increase. It is said that it is difficult to obtain the effect. Further, the maleic acid-based copolymer salt obtained by the above production method has insufficient performance as a water treatment agent and a detergent additive, and also has a problem in biodegradability.

<Effects of the Invention> The acid-type maleic acid-based polymer obtained by the method of the present invention configured as described above has a number average molecular weight of 300 to 5000,
It is preferably 400 to 3000 and has a D value (MW / MN) [MW is a weight average molecular weight and MN is a number average molecular weight] representing a molecular weight distribution of 2.5 or less, preferably 2.0 or less. .

The obtained acid-type maleic acid-based polymer exhibits excellent performance by being used for various purposes as it is, but may be appropriately neutralized with a basic compound depending on the purpose of use.

When the acid-type maleic acid-based polymer obtained by the production method of the present invention is used as a detergent additive, for example, it has excellent compatibility with the nonionic surfactant in the detergent composition and also has improved anti-corrosion properties. When gelling zinc for a water treatment agent composition, gelation is difficult. Furthermore, the acid-type maleic acid-based polymer obtained by the method of the present invention is characterized by having a low molecular weight and a narrow molecular weight distribution due to the adoption of the above-mentioned specific polymerization conditions. It has excellent properties as a treating agent and is also highly biodegradable. Further, in the production method of the present invention, since the amount of the metal ion used is very small, when the resulting acid-type maleic acid-based polymer is used for various purposes, the product purity is lowered, the metal salt is precipitated, and the hue is deteriorated. It is possible to obtain the effect of not having to worry about

According to the production method of the present invention, since the acid-type maleic acid-based polymer having the above characteristics is produced by aqueous solution polymerization, it is first polymerized in an organic solvent and then replaced with water to produce a human body. It has the advantages that there is no concern about contamination of residual organic solvent, which is harmful to the environment, and that the process can be shortened in manufacturing and the risk in disaster prevention is low.

Also, refining aids for cellulose fibers, bleaching aids for cellulose fibers, dyeing aids for cellulose fibers, pulp bleach pretreatment agents, bentonite-based muddy water conditioners, iron, copper, manganese,
It can be used very suitably in a wide range of applications such as deodorants in combination with polyvalent metals such as zinc, inorganic pigment dispersants, deinking aids for recycling used paper, chelating agents and the like.

<Examples> Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In addition,% and part in an example show weight% and a weight part, respectively.

Example 1 In a one-necked four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 196 parts of maleic anhydride, 75.1 parts of water (232 parts as maleic acid) and 0.01 part of ammonium iron (III) sulfate dodecahydrate. (5ppm as Fe ³⁺ : weight of maleic acid charged)
After charging, the aqueous solution was heated to boiling temperature under normal pressure with stirring. Next, under stirring, 96.3 parts of 60% hydrogen peroxide (28.9 g / mole of charged maleic acid) was continuously added dropwise over 3 hours to carry out a polymerization reaction. After the completion of the dropping, the system was stirred at the boiling temperature of the system for an additional 1 hour to complete the polymerization reaction, and an acid type polymaleic acid (1) having a solid content of 63% was obtained. The molecular weight and molecular weight distribution of the obtained acid-type polymaleic acid (1) are
It was measured using gel permeation chromatography. The obtained results are as shown in Table 1.

The column is a Tosoh G-3000PW (XL) + G-2500PW
(XL) was used, and a phosphate buffer (pH 7) was used as an eluent. Polyethylene glycol (manufactured by General Science Co.) was used as a molecular weight standard sample.

Examples 2 to 9 Exactly the same as Example 1 except that the amount of iron (III) ammonium sulfate dodecahydrate and the amount of hydrogen peroxide added dropwise are as shown in Table 1. Then, acid type polymaleic acids (2) to (9) were obtained. These acid-type polymaleic acids were analyzed in the same manner as in Example 1, and the results are shown in Table 1.

Example 10 Example 1 was repeated except that the amount of iron (III) ammonium sulfate dodecahydrate was changed to 0.040 parts, and this was made into a 0.40% aqueous solution (10 parts) and added dropwise together with hydrogen peroxide. Example 1
Acid-type polymaleic acid (10) was obtained in exactly the same manner as. This acid type polymaleic acid (10) was analyzed in the same manner as in Example 1, and the results are shown in Table 1.

Examples 11 to 14 In Example 1, iron (II) sulfate ammonium hexahydrate was used instead of iron (III) ammonium sulfate dodecahydrate in the amounts shown in Table 1 and the amount of hydrogen peroxide. Acid-type polymaleic acids (11) to (14) were obtained in exactly the same manner as in Example 1, except that the values shown in Table 1 were used. These acid-type polymaleic acids were analyzed in the same manner as in Example 1, and the results are shown in Table 1.

Examples 15 to 20 In Example 1, vanadyl sulphate was used in the amount shown in Table 1 instead of iron (III) ammonium sulfate dodecahydrate and the amount of hydrogen peroxide was as shown in Table 1. The acid-type polymaleic acid (1
5) to (20) were obtained. These acid-type polymaleic acids were analyzed in the same manner as in Example 1, and the results are shown in Table 1.

Examples 21 to 23 In Example 1, copper (II) sulfate pentahydrate was used instead of iron (III) ammonium sulfate dodecahydrate in the amounts shown in Table 1 and the amount of hydrogen peroxide was changed. Acid-type polymaleic acids (21) to (23) were obtained in exactly the same manner as in Example 1 except that the changes were as shown in Table 1. These acid-type polymaleic acids were analyzed in the same manner as in Example 1, and the results are shown in Table 1.

Example 24 Ammonium iron (III) sulfate dodecahydrate in Example 1
An acid type polymaleic acid (24) was obtained in exactly the same manner as in Example 1 except that 0.9 part (450 ppm as Fe ³⁺ : weight of maleic acid) was charged. The obtained acid type polymaleic acid (24) was analyzed in the same manner as in Example 1, and the results are shown in Table 1.

As shown in Table 1, the acid-type polymaleic acid obtained by the production method of the present invention has a number average molecular weight of 300 to 5000, preferably 400 to 3000, and a D value (MW / MN) showing a molecular weight distribution. [MW is a weight average molecular weight and MN is a number average molecular weight] is 2.5 or less, preferably 2.0 or less. The weight average molecular weight and number average molecular weight referred to herein are values obtained by gel permeation chromatography using polyethylene glycol as a molecular weight standard sample.

Comparative Example 1 In Example 1, iron (II) sulfate ammonium hexahydrate was used in place of iron (III) sulfate ammonium dodecahydrate 8.
A comparative polymaleic acid (1) was obtained in the same manner as in Example 1 except that 2 parts (5000 ppm as Fe ²⁺ : weight of maleic acid charged) were used. This comparative polymaleic acid (1) was analyzed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2 A polymer was prepared in the same manner as in Example 1 except that the amount of ammonium iron (III) sulfate dodecahydrate was 10.0 parts (5000 ppm as Fe ³⁺ : weight of maleic acid charged). Obtained. Further, the same analysis as in Example 1 was performed, and the results are shown in Table 2.

Comparative Examples 3 to 4 Exactly the same as Example 1 except that iron (III) ammonium sulfate dodecahydrate was not used and the amount of hydrogen peroxide used was changed as shown in Table 2. As a result, comparative polymaleic acids (3) and (4) were obtained. The comparative polymaleic acids (3) and (4) were analyzed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 5 In Example 1, 167 parts of a 48% aqueous sodium hydroxide solution was added at the time of charging to neutralize 50 mol% of the carboxyl groups of maleic acid, and no iron (III) sulfate ammonium dodecahydrate was used. Comparative polymaleate (5) was obtained in the same manner as in Example 1 except for above. This comparative polymaleate (5) was analyzed in the same manner as in Example 1 and the results were
Shown in the table.

Example 6 In Comparative Example 5, iron (II) ammonium sulfate hexahydrate
A comparative polymaleic acid salt (6) was obtained in the same manner as Comparative Example 5 except that 0.0082 parts (5 ppm as Fe ²⁺ : weight of maleic acid charged) was added. This comparative polymaleic acid salt (6) was analyzed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 7 Comparative polymaleic acid was prepared in the same manner as in Comparative Example 5 except that 0.010 parts of iron (III) ammonium sulfate dodecahydrate (5 ppm as Fe ³⁺ : weight of charged monomer) was added. A salt (7) was obtained. This comparative polymaleic acid salt (7) was analyzed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 8 A flask equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser was charged with 196 parts of maleic anhydride and 3 parts of water.
00 parts (232 parts as maleic acid) were added and heated to 60 ° C. with stirring. The heating was stopped and then 138 parts of 30% aqueous sodium hydroxide solution was added, followed by 140 parts of isopropanol. Then, after raising the temperature of the system to the reflux temperature, 0.25 parts of a 4.98% aqueous solution of ferrous sulfate (FeSO ₄ .7H ₂ O) (1% as Fe ²⁺ ) was added, followed by 60% hydrogen peroxide solution. 40 copies of 6
It dripped over time. After dripping, after heating for another 2 hours,
The residual isopropanol was removed to obtain a comparative polymaleic acid salt (8). This comparative polymaleate (8) was analyzed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 9 In Example 1, vanadyl sulfate was used in place of the ammonium iron (III) sulfate dodecahydrate, and the amount thereof and the amount of hydrogen peroxide used were as shown in Table 3, except that
Comparative polymaleic acid (9) in exactly the same manner as in Example 1.
Got This comparative polymaleic acid (9) was analyzed in exactly the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 10 The same apparatus as in Example 1 was charged with 196 parts of maleic anhydride, 131 parts of monochlorobenzene and 65.4 parts of xylene, and then 1
Warmed to 40 ° C. A dropping liquid consisting of 65.4 parts of di-tert-butyl peroxide, 41 parts of xylene, and 65.4 parts of monochlorobenzene was added dropwise over 3 hours, and then aging was carried out at the boiling point for 3 hours. After distilling off the solvent, pure water 19
Hydrolysis was carried out by adding 7 parts to obtain a comparative polymaleic acid (1
0) was obtained. This comparative polymaleic acid (10) was used in Example 1
The analysis was performed in exactly the same manner as in, and the results are shown in Table 2.

Examples 25 to 48 Acid-type polymaleic acid (1) obtained in Examples 1 to 24
The following tests were conducted to evaluate the performance of (24) as a scale inhibitor. 170 g of water in a glass bottle with a capacity of 225 ml
Add 10g of calcium chloride dihydrate 1.56% aqueous solution and 3g of acid type polymaleic acid 0.02% aqueous solution (3ppm to the resulting supersaturated aqueous solution), and add 10g of sodium bicarbonate 3% aqueous solution and 7g of water. The total amount was 200 g. The supersaturated solution of the obtained calcium carbonate 530 ppm was tightly stoppered,
It heat-processed at 70 degreeC for 3 hours. Then, after cooling, the precipitate was filtered through a 0.1 μm membrane filter, and the filtrate was JIS
It was analyzed according to K 0101. The calcium carbonate scale inhibition rate (%) was calculated by the following formula. The results obtained are shown in Table 3.

A: Calcium concentration dissolved in the liquid before the test B: Calcium concentration in the filtrate without scale inhibitor C: Calcium concentration in the filtrate after the test Comparative Examples 11 to 20 The performance of the comparative polymaleic acids (salts) (1) to (10) obtained in Comparative Examples 1 to 10 as scale inhibitors was evaluated in exactly the same manner as in Examples 24 to 48. The results obtained are shown in Table 4.

Examples 49 to 72 Acid-type polymaleic acid (1) obtained in Examples 1 to 24
The following tests were conducted to evaluate the performance of (24) as a detergent builder.

Example 1 in 50 ml of 10 ^-3 mol / calcium chloride aqueous solution
The acid type polymaleic acid (1) to (24) obtained in 24 was added in an amount of 10 mg in terms of solid content, and an ion analyzer manufactured by Orion
Using MODEL701 and a calcium ion electrode, the amount of calcium ions blocked by acid-type polymaleic acid (1) to (24) was determined, and the chelating ability of each acid-type polymaleic acid was measured by the following formula, It was shown to.

Comparative Examples 21 to 30 Comparative polymaleic acid (salt) obtained in Comparative Examples 1 to 10
For (1) to (10), performance evaluation as a detergent builder was performed in the same manner as in Examples 49 to 72. The results are shown in Table 6.

¹³ C—N of acid-type polymaleic acid (1) obtained in Example 1
When the MR chart was examined, it was as shown in FIG.
As shown in the chart of FIG. 1, a peak showing carbon of CH ₂ was obtained from 30 ppm to 40 ppm, and the acid-type polymaleic acid (1) contained an acrylic acid structural unit resulting from decarboxylation during polymerization. You can see that

Example 73 In a one-necked four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 196 parts of maleic anhydride and 75.1 parts of water (232 parts as maleic acid) and vanadyl sulfate dihydrate 0.0153 parts
(20 ppm as VO 2 ⁺ / weight of monomer component) was charged, and the aqueous solution was heated to boiling temperature under normal pressure with stirring. Then, with stirring, 76.7 parts of 60% hydrogen peroxide (20 g / per mol of the monomer component) and 26 parts of 3-methyl-3-buten-1-ol (isoprenol) were continuously added dropwise over 3 hours. Then, the polymerization reaction was carried out. After completion of the dropwise addition, the system was further stirred at the boiling temperature of the system for 1 hour to complete the polymerization reaction, and an acid type maleic acid copolymer (73) having a solid content of 71% was obtained. The pH during polymerization is
It was 0.3.

The molecular weight and molecular weight distribution of the obtained acid maleic acid copolymer (73) were measured by gel permeation chromatography. The results obtained are shown in Table 7.

The measurement conditions of gel permeation chromatography were the same as above.

Further, the biodegradation rate of the obtained acid-type maleic acid copolymer (73) was calculated by the following formula.

X: Biodegradation rate (%) in 5 days D: Biological oxygen demand of acid type maleic acid copolymer in 5 days (BOD5) (* 1) E: In 5 days of residual monomer Biological oxygen demand (* 2) F: Theoretical oxygen demand of acid type maleic acid copolymer (* 3) G: Theoretical oxygen demand of residual monomer (* 1): JIS K 0102 method Was measured according to.

(* 2): The residual monomer was analyzed and quantified by gel permeation chromatography and gas chromatography. The biological oxygen demand of each monomer component is JIS K
Measurement was carried out by the method of No. 0102, and the biological oxygen demand of all the remaining monomers was calculated.

(* 3): The amount of oxygen required for complete oxidation was calculated from the elemental analysis value of each acid-type maleic acid-based copolymer.

Examples 74 and 75 In Example 73, the amount of vanadyl sulfate dihydrate was adjusted to the seventh
Acid-type maleic acid copolymers (74) to (75) were obtained in exactly the same manner as in Example 73 except that the conditions were as shown in the table.

These acid-type maleic acid-based copolymers were analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Example 76 In Example 73, 10 parts of a 0.45% aqueous solution of ammonium iron (III) sulfate dodecahydrate (20 ppm as Fe ^{3 +} / weight of monomer component) was added in place of vanadyl sulfate dihydrate. An acid-type maleic acid copolymer (76) was obtained in exactly the same manner as in Example 73 except that hydrogen peroxide was simultaneously added.

This acid-type maleic acid copolymer (76) was analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Example 77 In Example 73, in place of vanadyl sulfate dihydrate, 0.045 parts of iron (III) ammonium sulfate dodecahydrate (Fe ³⁺
As an acid type maleic acid-based copolymer (7
7) got.

This acid-type maleic acid copolymer (77) was analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Example 78 Example 73 was repeated except that 0.013 parts of anhydrous copper (II) sulfate (20 ppm as Cu 2 ⁺ / weight of monomer component) was charged in place of vanadyl sulfate dihydrate in Example 73. An acid-type maleic acid copolymer (78) was obtained in the same manner as in.

This acid-type maleic acid copolymer (78) was analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Examples 79 and 80 In Example 73, 0.045 parts of iron (III) ammonium sulfate dodecahydrate was used in place of vanadyl sulfate dihydrate, and the amount of hydrogen peroxide added was shown in Table 7. Acid-type maleic acid copolymers (79) and (80) were obtained in exactly the same manner as in Example 73 except that the conditions were as shown.

These acid-type maleic acid-based copolymers were analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Example 81 In Example 73, 1-as a complexing agent was added at the time of initial charging.
An acid-type maleic acid copolymer (81) was obtained in exactly the same manner as in Example 73 except that 0.005 g of hydroxyethylidene-1,1-diphosphonic acid was added.

This acid-type maleic acid copolymer (81) was analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Example 82 In Example 73, at the time of 1.5 hours after the start of hydrogen peroxide dropping, the dropping was stopped for 60 minutes, and while the reaction temperature during the dropping was kept at the boiling point (110 ° C.), hydrogen peroxide was added again. Dripping
I went for 1.5 hours. An acid type maleic acid copolymer (82) was obtained in the same manner as in Example 73 except for the above.

This acid-type maleic acid copolymer (82) was analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Examples 83 and 84 In Example 73, 0.045 parts of ammonium iron (III) sulfate dodecahydrate was used in place of vanadyl sulfate dihydrate, and the amount of the monomer to be dropped and the amount of the dropped monomer The acid-type maleic acid-based copolymer (8) was prepared in exactly the same manner as in Example 73, except that the amount of hydrogen oxide was as shown in Table 7.
3) and (84) were obtained.

These acid-type maleic acid-based copolymers were analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Examples 85 to 99 In Example 73, the acid type was exactly the same as in Example 73, except that the type and amount of the dropped monomer and the type and amount of the metal ion were as shown in Table 7. Maleic acid type copolymers (85) to (99) were obtained.

These acid-type maleic acid-based copolymers were analyzed in the same manner as in Example 73, and the results are shown in Table 7.

Comparative Example 31 Comparative maleic acid was prepared in the same manner as in Example 73, except that 166.6 parts of a 48% aqueous sodium hydroxide solution (neutralization degree to all carboxylic acids was 50%) was added at the time of charging. A system copolymer salt (31) was obtained.

This comparative maleic acid copolymer salt (31) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 32 A comparative maleic acid copolymer (32) was obtained in the same manner as in Example 73 except that vanadyl sulfate dihydrate was not used at all.

This comparative maleic acid copolymer (32) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 33 A comparative maleic acid copolymer (33) was obtained in exactly the same manner as in Example 73, except that the amount of vanadyl sulfate / dihydrate used was changed to 2.30 parts.

This comparative maleic acid copolymer (33) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Examples 34 to 37 In Example 73, the same procedure as in Example 3 was carried out except that, instead of vanadyl sulfate dihydrate, metal ions shown in Table 8 were added in the amounts shown in Table 8. As a result, comparative maleic acid type copolymers (34) to (37) were obtained.

This comparative maleic acid copolymer was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Examples 38 to 41 A comparative maleic acid-based copolymer was prepared in the same manner as in Example 73, except that the amount of peroxide shown in Table 8 was used instead of hydrogen peroxide as the polymerization catalyst. Polymer (38)
Got (41).

This comparative maleic acid-based copolymer was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 42 The same as Example 73 except that 26.0 parts of acrylic acid was used as the water-soluble unsaturated weight, vanadyl sulfate was not used, and the amount of hydrogen peroxide was as shown in Table 8. A comparative maleic acid copolymer (42) was obtained in exactly the same manner.

This comparative maleic acid copolymer (42) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 43 In Example 73, 26.0 parts of acrylic acid was used as the water-soluble unsaturated monomer, and 181.7 parts of a 48% aqueous sodium hydroxide solution (neutralization degree to all carboxylic acids: 50%) was added at the time of charging for neutralization. A comparative maleic acid type copolymer salt (43) was obtained in exactly the same manner as in Example 73 except that the amount of hydrogen peroxide was changed as shown in Table 8.

This comparative maleic acid copolymer salt (43) was analyzed in exactly the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 44 In Example 73, 26.0 parts of acrylic acid was used as the water-soluble unsaturated weight, and vanadyl sulfate dihydrate was added to 2.
A comparison was made in exactly the same manner as in Example 73, except that 30 parts (3000 ppm as VO 2 ⁺ / weight of monomer component) was used, and the amount of hydrogen peroxide used was as shown in Table 8. A maleic acid-based copolymer (44) was obtained.

This comparative maleic acid copolymer (44) was analyzed in exactly the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 45 In Example 73, 26.0 parts of acrylic acid was used as the water-soluble unsaturated monomer, and instead of vanadyl sulfate dihydrate,
Example except that 6.69 parts of iron (III) sulfate ammonium dodecahydrate (3000 ppm as Fe ^{3 +} / amount of monomer component) was charged and the amount of hydrogen peroxide was changed as shown in Table 8. A comparative maleic acid copolymer (45) was obtained in exactly the same manner as in 73.

This comparative maleic acid copolymer (45) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 46 In Example 73, the amount of 60% hydrogen peroxide used was 19.2 g (5
Comparative maleic acid copolymer (46) was obtained in exactly the same manner as in Example 73 except that the amount was changed to g / monomer component 1 mol).

This comparative maleic acid copolymer (46) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 47 The same apparatus as in Example 73 was charged with 196 parts of maleic anhydride, 131 parts of monochlorobenzene and 65.4 parts of xylene, and then 1
Warmed to 40 ° C. A liquid drop 1 consisting of 65.4 parts of di-tert-butyl peroxide, 41 parts of xylene and 65.4 parts of monochlorobenzene and a liquid drop 2 of 26 parts of acrylic acid were added dropwise over 3 hours and then at the boiling point for 3 hours. Aged. After the solvent was distilled off, 197 parts of pure water was added for hydrolysis to obtain a comparative maleic acid copolymer (47).

This comparative maleic acid copolymer (47) was analyzed in exactly the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 48 196 parts of maleic anhydride and 300 parts of water (232 parts as maleic acid) were added to a flask equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser, and the mixture was stirred under stirring 60
Heated to ° C. Then stop heating and add 30% caustic soda 13
After adding 8 parts, 140 parts of isopropanol was added, followed by 26 parts of acrylic acid. Then, after raising the temperature of the system up to the reflux temperature, 4.9 ferrous sulfate (FeSO ₄ · 7H ₂ O)
0.25 parts of 8% aqueous solution (1% as Fe ²⁺ ) was added, followed by 6
40 parts of 0% hydrogen peroxide solution was added dropwise over 6 hours.

After completion of the dropping, the mixture was heated for additional 2 hours, and then the remaining isopropanol was removed to obtain a comparative maleic acid copolymer salt (48). This comparative maleic acid-based copolymer salt (48) was used in Example 73.
Analysis was carried out in the same manner as above, and the results are shown in Table 8.

Comparative Example 49 In the same polymerization container as used in Example 73, 77.3 parts of 1-allyloxy-2,3-dihydroxypropane (glycerol monoallyl ether), 116 parts of maleic acid, 166.6 parts of 48% aqueous sodium hydroxide solution and water. Prepared 157.4 copies.
With stirring, the aqueous solution was heated to the boiling point of the system.

Next, 100 parts of 10% ammonium peroxide aqueous solution was added dropwise from the dropping funnel over 2 hours. During this period, the polymerization temperature was controlled so as to be the boiling point of the system throughout. Then, the mixture was kept at the same temperature for 30 minutes to complete the polymerization to obtain a comparative maleic acid type copolymer salt (49). This comparative maleic acid type copolymer salt (49) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 50 Maleic acid 14 was added to the same polymerization vessel as used in Example 73.
5 parts, 48% aqueous sodium hydroxide solution 208.3 parts and water 156.7
The department was set up. After purging with nitrogen, the temperature was raised to 95 ° C. with stirring.

Then, 35.8 parts of a 50% aqueous solution of sodium 3-allyloxy-2-hydroxypropanesulfonate (3-allyloxy-
16.2 parts of 2-hydroxypropanesulfonic acid) and 50 parts of a 10% ammonium persulfate aqueous solution were added dropwise from separate dropping nozzles over 4 hours.

The copolymerization temperature during the dropping was controlled to be 95 ° C throughout. After the dropwise addition was completed, the temperature was kept at the same temperature for 30 minutes to complete the copolymerization to obtain a comparative maleic acid type copolymer salt (50).

This comparative maleic acid-based copolymer salt (50) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Comparative Example 51 In Example 73, except that the amounts of the monomer components used, the amount of hydrogen peroxide, and the amount of metal ions used were as shown in Table 8,
By the same procedure as in Example 73, a comparative maleic acid copolymer (51) was obtained.

This comparative maleic acid copolymer (51) was analyzed in the same manner as in Example 73, and the results are shown in Table 8.

Examples 100-126 Acid-type maleic acid-based copolymers 73-99 obtained in Examples 73-99
In order to evaluate the performance of 99 as a scale inhibitor, the same tests as in Examples 25 to 48 were performed, and the results shown in Table 9 were obtained.

Comparative Examples 52-72 Comparative maleic acid type copolymers (salts) obtained in Comparative Examples 31-51 (salts) (31)-(51) in the same manner as in Examples 100-126 were evaluated for performance as scale inhibitors. went. The results obtained are shown in Table 10.

Examples 127 to 153 The acid-type maleic acid-based copolymers (7
For 3) to (99), performance evaluation as a detergent builder was performed in the same manner as in Examples 49 to 72. The results are shown in Table 11.

Comparative Examples 73 to 93 The comparative maleic acid-based copolymers (salts) (31) to (51) obtained in Comparative Examples 31 to 51 were evaluated for their performance as detergent builders in the same manner as in Examples 127 to 153. It was The results are shown in Table 12.

[Brief description of drawings]

FIG. 1 shows the acid type polymaleic acid (1) obtained in Example 1.
FIG.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08F 2/44 MCQ 4/30 MEQ 216/14 MKZ C11D 3/37 (72) Inventor Akiaki Fujiwara Hyogo Hiroyuki Taniguchi, Inspector, Himeji Research Institute, Nippon Catalysis Chemical Co., Ltd., 1 992 Nishi-oki, Okihama, Aboshi-ku, Himeji-shi, Japan

Claims (13)

[Claims] 1. A monomer component consisting of maleic acid (A) only, or maleic acid (A) 50 to 99.9% (meaning% by weight,
The same shall apply hereinafter) and other water-soluble unsaturated monomer (B) 50 to 0.1
% As a polymerization catalyst in the presence of 0.5 to 500 ppm of one or more metal ions selected from the group consisting of iron ions, vanadium atom-containing ions and copper ions with respect to the monomer components. Aqueous solution polymerization with 8-100g of hydrogen peroxide per mol of monomer, number average molecular weight of 300-5
000, a method for producing an acid-type maleic acid-based polymer, which comprises obtaining an acid-type maleic acid-based polymer having a D value of 2.5 or less. D value = MW / MN MW: weight average molecular weight MN: number average molecular weight 2. The metal ion is one or more selected from the group consisting of Fe ²⁺ , Fe ³⁺ , Cu ⁺ , Cu ²⁺ , V ²⁺ , V ³⁺ , VO ²⁺ and VO ₃ ^−. The method of claim 1. 3. The metal ion is one or more of Fe ³⁺ , Cu ^{2+ and} VO ^2+.
The method described in. 4. The method according to claim 1, wherein the amount of metal ions present is 5 to 100 ppm. 5. The method according to claim 1, wherein 10 to 80 g of hydrogen peroxide is used per mol of the monomer component. 6. The process according to claim 1, wherein 15 to 50 g of hydrogen peroxide are used per mol of the monomer component. 7. The method according to claim 1, wherein the solid content of the charged monomer component is 30 to 99%, and the polymerization temperature is 50 to 160 ° C. 8. The method according to claim 1, wherein after hydrogen peroxide is continuously charged for a certain period of time, the hydrogen peroxide is once stopped and then continuously charged again for a certain period of time. 9. The water-soluble unsaturated monomer (B) is an unsaturated monocarboxylic acid type monomer, an unsaturated polycarboxylic acid type monomer, or the general formula (1). (In the formula, R ¹ and R ² each independently represent hydrogen or a methyl group, and R ¹ and R ² do not simultaneously represent a methyl group, and R ³ is —CH ₂ —, — (CH ₂ ) ₂ - or -C (CH _{3) 2} - represents, and the total number of carbon atoms in R ^1, R ² and R ³ are 3, Y represents an alkylene group having 2 to 3 carbon atoms, n represents 0 or 1 An integer of from 100 to 100), an unsaturated alcohol-based monomer represented by the general formula (2) (Wherein R ¹ represents hydrogen or a methyl group, a, b, d and f each independently represent 0 or an integer of 1 to 100, and a + b + d + f = 0 to 100, and an —OC ₂ H ₄ unit And -OC ₃ H ₆ -units may be combined in any order,
When d + f is 0, Z represents a hydroxyl group, a sulfonic acid group and a (phosphite) group, and when d + f is a positive integer of 1 to 100, Z represents a hydroxyl group. ] The method according to claim 1, which is one or more selected from the group consisting of unsaturated (meth) allyl ether-based monomers represented by 10. A water treatment agent containing the acid-type maleic acid polymer obtained by the method according to any one of claims 1 to 9. 11. The water treatment agent according to claim 10, which is a scale inhibitor. 12. A detergent additive containing the acid-type maleic acid polymer obtained by the method according to any one of claims 1 to 9. 13. The detergent additive according to claim 12, which is a detergent builder.