Ester bond-containing polycarboxylic acid (salt) and method for producing same

Abstract

The purpose of the present invention is to provide an ester bond-containing polycarboxylic acid (salt) having excellent biodegradability and an excellent rate of change in alkaline degradation, a method for producing the same, and a detergent composition containing said ester bond-containing polycarboxylic acid (salt). The present invention pertains to an ester bond-containing polycarboxylic acid (salt) that has, in the main chain thereof, a structural unit derived from an ester group, that has a carboxylic acid (salt) in a side chain thereof, and that has a carboxylic acid (salt) at a β-position or γ-position of carbonyl carbon of said ester group.

Description

[Technical field]

[0001] The present disclosure relates to an ester bond-containing polycarboxylic acid (salt) that is excellent in biodegradability and alkali decomposability, a method for producing the same, and a detergent composition containing the compound. [Background technology]

[0002] Conventionally, polyacrylic acid and copolymers of acrylic acid and maleic acid have been used as inexpensive and high-performance detergent builders. In recent years, polymers used as detergent builders have been required to be water-soluble polymers with low environmental impact, and to have builder properties and biodegradability.

[0003] For example, Patent Document 1 discloses a vinyl acetate / acrylic acid / maleic anhydride copolymer.

[0004] Moreover, Patent Document 2 discloses a copolymer of 2-methylene-1,3-dioxepane and acrylic acid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 4-311706 [Patent Document 2] JP 2000-38595 A Summary of the Invention [Problem to be solved by the invention]

[0006] Meanwhile, the present inventors have found through their investigations that when a homopolymer of acrylic acid or a copolymer with another comonomer such as maleic acid is used in a detergent composition, the composition has excellent anti-soil redeposition properties.

[0007] However, the copolymers described in Patent Documents 1 and 2 have problems in that they are insufficient in biodegradability and there is room for improvement in anti-redeposition ability.

[0008] The present disclosure has been made in consideration of the above-mentioned points, and an object of the present disclosure is to provide an ester bond-containing polycarboxylic acid (salt) which has a structural unit derived from an ester group in its main chain, a carboxyl group in its side chain, and a carboxylic acid (salt) at the β-position or γ-position of the carbonyl carbon of the ester group, a method for producing the same, and a detergent composition containing the ester bond-containing polycarboxylic acid (salt). [Means for solving the problem]

[0009] As a result of further investigations, the present inventors have found that when an ester bond-containing polycarboxylic acid (salt) having a structural unit derived from an ester group in the main chain, a carboxyl group in the side chain, and a carboxylic acid (salt) at the β- or γ-position of the carbonyl carbon of the ester group is used as a detergent composition, the composition has excellent biodegradability and alkaline decomposition conversion rate, and have completed the present invention.

[0010] That is, the present invention relates to an ester bond-containing polycarboxylic acid (salt) having a structural unit derived from an ester group in the main chain, a carboxylic acid (salt) in the side chain, and a carboxylic acid (salt) at the β-position or γ-position of the carbonyl carbon of the ester group.

[0011] The ester bond-containing polycarboxylic acid (salt) preferably has an alkali decomposition conversion rate of 10% or more.

[0012] The above ester bond-containing polycarboxylic acid (salt) preferably has a biodegradability of 20% or more.

[0013] The present invention also relates to a detergent composition comprising the ester bond-containing polycarboxylic acid (salt) of the present invention.

[0014] The present invention also relates to a method for producing an ester bond-containing polycarboxylic acid (salt), which includes a step of reacting a compound having an unsaturated double bond and an acid anhydride group with a compound having two or more hydroxyl groups, and a step of reacting a double bond of the product of the above step.

[0015] The present invention also relates to a method for producing an ester bond-containing polycarboxylic acid (salt), which includes a step of reacting a compound having three or more carboxylic acids (salts) or an anhydride thereof with a compound having two or more hydroxyl groups.

Advantages of the Invention

[0016] According to the present disclosure, it is possible to provide an ester bond-containing polycarboxylic acid (salt) excellent in biodegradability and alkali decomposition change rate, a method for producing the same, and a detergent composition containing the ester bond-containing polycarboxylic acid (salt).

Brief Description of the Drawings

[0017] [Figure 1] It is a proton NMR chart of the ester bond-containing polycarboxylic acid (4) obtained in Example 4. The peak at 3.6 - 4.3 ppm is considered to be the peak of the hydrogen bonded to the carbon adjacent to the ester bond.

Modes for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present disclosure will be described in detail. The following description of the preferred embodiments is merely illustrative in nature and is in no way intended to limit the present disclosure, its applications, or its uses.

[0019] In the following description, unless otherwise specified, “%” means “mass %” and “part” means “part by mass”. “A~B” indicating a range means A or more and B or less. In the present disclosure, “(meth)acrylate” means “acrylate” or “methacrylate”, and “(meth)acrylic” means “acrylic” or “methacrylic”.

[0020] [Ester bond-containing polycarboxylic acid (salt)] The ester bond-containing polycarboxylic acid (salt) according to this embodiment has the following substituents and structural units 1) to 3). 1) Structural units derived from ester groups in the main chain 2) Carboxylic acid (salt) on the side chain 3) Carboxylic acid (salt) at the β- or γ-position of the carbonyl carbon of the ester group in the main chain The ester group present in the main chain can generally be expressed as "-C=OO-" or "-COO-" in the chemical formula. When two or more of these bonds are present in the main chain of a polymer, the ester bond-containing polycarboxylic acid (salt) can be contained in a detergent composition or the like, and after the detergent composition is discharged into a river or the like, it can contribute to reducing the environmental load due to the hydrolysis of the ester bond present in the main chain and the biodegradation of the compound that has been hydrolyzed to a low molecular weight. The structural unit derived from the ester group in 1) above means a structure represented by "-C=OO-" or "-COO-".

[0021] The ester bond-containing polycarboxylic acid (salt) of the present disclosure has two or more carboxylic acids (salts) in the side chain, resulting in a polycarboxylic acid (salt) structure. Carboxylic acid (salt) can also be represented as “—COOM.” M is a hydrogen atom, an alkali metal atom, or an ammonium group, more preferably a hydrogen atom, sodium, or potassium, and even more preferably a hydrogen atom or sodium.

[0022] In addition, in one example of the structure of the ester bond-containing polycarboxylic acid (salt) of the present disclosure, the structure of the ester group in the main chain and the carboxylic acid (salt) moiety located at the β or γ position of the carbonyl carbon of the ester group in the main chain can be represented by the following general formula (1).

[0023] [ka]

[0024] In the general formula (1), a, b, c, and d are substituents containing carbon atoms at the α-position, β-position, γ-position, and δ-position from the carbonyl carbon of the ester group, respectively. a is a methylene group (-CH 2 -), -CHOH- group, and methine group (>CH-). b is a methylene group (-CH 2 -), methine group (>CH-), -CR 1 COOH(M)- group. c is a single bond, a methylene group (-CH 2 -), -CR 1 COOH(M)- group. d is a single bond or -CR 1 COOH(M)-group. R 1 are the same or different and represent a hydrogen atom or a methyl group, M represents a hydrogen atom, an alkali metal atom or an ammonium group, and m represents a positive integer of 1 or more.

[0025] In producing the ester bond-containing polycarboxylic acid (salt) of the present disclosure, when copolymerization is performed using a dicarboxylic acid compound such as acrylic acid and maleic acid (anhydride), the carboxylic acid (salt) is bonded to the β- and δ-positions in the general formula (1).When polymerization is performed using a single or multiple dicarboxylic acid (anhydride) compounds having double bonds such as maleic acid (anhydride) and itaconic acid (anhydride), the carboxylic acid (salt) is bonded to the γ-position.

[0026] The structural unit derived from the ether bond constituting the ester bond can be represented by the following general formula (2).

[0027] [ka]

[0028] In general formula (2), R 2 represents a substituent having 2 to 10 carbon atoms and having two bonds, and n represents a positive integer of 1 or more.

[0029] R in general formula (2) 2 A specific example of this is -CH 2 CH 2 -, -CH2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 -, -CHCH 3 CH 2 -, -CHCH 3 CH 2 CH 2 -, -CH 2 CHCH 3 CH 2 -, -CH 2 CH 2 NHCH 2 CH 2 -, branched or straight chain, two bonded substituents such as -CH 2 CH 2 OCH 2 CH 2 -, -CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 -, -CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 -, a substituent having two chain bonds including an ether bond, a cyclic substituent having 3 to 10 carbon atoms and two bonds, -CH 2 CH(OH)CH 2 -, -CH 2 CH(OH)CH 2 CH 2 -, -CH 2 CH 2 CH(OH)CH 2 CH 2-, -CH 2 CH(OH)CH 2 CH 2 CH 2 CH 2 -, etc., which have a chain-like two-bond substituent with a hydroxyl group. From the viewpoint of biodegradability and alkaline decomposition rate, -CH 2 CH 2 - groups and -CH 2 CHOHCH 2 - group is preferred.

[0030] An example of a polymer of an ester bond-containing polycarboxylic acid (salt) of the present invention is one having a structure in which the structure of the following general formula (3) is a repeating unit.

[0031] [ka] In general formula (3), a 1 , a 2 are the same or different and are the same as a in general formula (1). 1 , b 2 are the same or different and are the same as b in general formula (1). 1 , c 2 are the same or different and are the same as c in general formula (1). 1 , d 2 are the same or different and are the same as d in general formula (1). 2 is R in general formula (2) 2 where p is a positive integer equal to or greater than 1.

[0032] A specific example of the structure of the polymer of the ester bond-containing polycarboxylic acid (salt) of the present disclosure can be represented by the following general formula (4).

[0033] [ka]

[0034] R in general formula (4) 2are the same or different and are the same as those in the general formula (2). 3 are the same or different and each represents a methylene group, -CHCH 3 R 4 represents a hydrogen atom, an alkali metal atom, an ammonium group, or an organic group, and two R 4 At least one of the groups is a hydrogen atom, an alkali metal atom, or an ammonium group, and x represents a positive integer of 1 or more.

[0035] R in general formula (4) 4 The organic group may be a monovalent organic group obtained by removing one hydroxyl group from a compound having a hydroxyl group. Examples of the compound having a hydroxyl group include compounds having two or more hydroxyl groups of the present disclosure described below.

[0036] In the structure represented by general formula (4), two R 4 An ester bond-containing polycarboxylic acid (salt) having a structure represented by the following general formula (4-1), in which both are hydrogen atoms, can be obtained, for example, by reacting maleic anhydride with ethylene glycol and then polymerizing the double bond derived from maleic anhydride by a radical reaction or the like.

[0037] [ka]

[0038] R in general formula (4-1) 2 , R 3 , and x is the same as in general formula (4).

[0039] A specific example of another structure of the polymer of ester bond-containing polycarboxylic acid (salt) of the present disclosure can be represented by the following general formula (5).

[0040] [ka]

[0041] R in general formula (5) 2is the same as that in the general formula (2). 4 is the same as the general formula (4), and five R 4 At least one of R is a hydrogen atom, an alkali metal atom, or an ammonium group. 5 is a methylene group. y is a positive integer of 1 or more.

[0042] In the structure represented by general formula (5), R 4 An ester bond-containing polycarboxylic acid (salt) having a structure represented by the following general formula (5-1), in which all of are hydrogen atoms, can be obtained, for example, by reacting maleic anhydride with ethylene glycol, and then polymerizing the double bonds derived from acrylic acid and maleic anhydride by a radical reaction or the like.

[0043] [ka]

[0044] R in general formula (5-1) 2 , R 5 , y is the same as in general formula (5).

[0045] A specific example of still another structure of the polymer of ester bond-containing polycarboxylic acid (salt) of the present disclosure can be represented by the following general formula (6).

[0046] [ka]

[0047] R in general formula (6) 2 is the same as that in the general formula (2). 4 is the same as the general formula (4), and two R 4 At least one of R is a hydrogen atom, an alkali metal atom, or an ammonium group. 6 is a methylene group. z is a positive integer of 1 or more.

[0048] In the structure represented by general formula (6), two R 4An ester bond-containing polycarboxylic acid (salt) having a structure represented by the following general formula (6-1), in which both are hydrogen atoms, can be obtained, for example, by reacting itaconic anhydride with glycerin, and then polymerizing the double bond derived from itaconic anhydride by a radical reaction, etc. In addition, since itaconic anhydride can produce a homopolymer, when a polymer of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is synthesized using itaconic anhydride as a raw material, not only a linear polymer but also a branched polymer is produced.

[0049] [ka]

[0050] R in general formula (6-1) 2 , R 6 , z is the same as in general formula (6).

[0051] An example of still another structure of the polymer of ester bond-containing polycarboxylic acid (salt) of the present disclosure includes a structure represented by the following general formula (7) in addition to any of the structures represented by the general formulas (4) to (6) above.

[0052] [ka]

[0053] R in general formula (7) 2 is the same as that in the general formula (2). 4 is the same as that in the general formula (4). 7 is an organic group. q is a positive integer of 1 or more.

[0054] R in general formula (7) 7 The organic group may be a divalent hydrocarbon group having 1 to 4 carbon atoms, or a divalent hydrocarbon group having 1 to 4 carbon atoms in which one or more hydrogen atoms have been replaced with a hydroxyl group or -COOR. 4 Group(R 4 is the same as that of the above general formula (4).

[0055] The ester bond-containing polycarboxylic acid (salt) having the structure represented by general formula (7) can be obtained, for example, by reacting maleic anhydride with ethylene glycol and citric acid, and then polymerizing the double bond derived from the maleic anhydride by a radical reaction, etc. In this case, the obtained ester bond-containing polycarboxylic acid (salt) has the structure represented by general formula (4-1) above in addition to the structure represented by general formula (7).

[0056] Still another specific example of the polymer of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is a polymer having a repeating unit of the structure represented by the following general formula (8).

[0057] [ka]

[0058] R in general formula (8) 2 is the same as that in the general formula (2). 8 represents an oligomer group formed by removing two or more carboxylic acid (salt) groups from an oligomer of a compound having an unsaturated double bond and a carboxylic acid (salt) group, and R 8 It has a carboxylic acid (salt) at the β- or γ-position of the carbonyl carbon bonded to the carboxyl group. r is a positive integer of 1 or greater. R 8 The oligomer group represented by the formula (I) may have three or more carboxylic acid (salt) groups removed from the oligomer group, and in that case, the positions where the carboxylic acid (salt) groups have been removed may be represented by -COO-R 2 It is bonded to multiple other oligomer groups via a linking group represented by -OCO-. 8 When the oligomer group represented by the formula (I) is a divalent oligomer group from which only two carboxylic acid (salt) groups have been removed, -COO-R 2 It is only attached to two other oligomeric groups via the -OCO- groups. R 8When the oligomer group represented by the formula (I) is an n-valent group from which n (n is an integer of 3 or more) carboxylic acid (salt) groups have been removed, -COO-R 2 It will be bonded to other n oligomer groups via the -OCO- groups.

[0059] The ester bond-containing polycarboxylic acid (salt) having the structure represented by general formula (8) can be obtained, for example, by using an oligomer of a compound having an unsaturated double bond and a carboxylic acid (salt) group as a compound having three or more carboxylic acids (salts), and reacting the oligomer with a compound having two or more hydroxyl groups. As the compound having an unsaturated double bond and a carboxylic acid (salt) group, and the compound having two or more hydroxyl groups, those described below can be used.

[0060] [Physical properties of ester-containing polycarboxylic acids (salts)] The ester bond-containing polycarboxylic acid (salt) of the present disclosure is a water-soluble polymer. Water-soluble means that 1 part by mass or more of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is dissolved in 100 parts by mass of pure water at room temperature and normal pressure. Since the ester bond-containing polycarboxylic acid (salt) of the present disclosure is water-soluble, it can be suitably used in detergent builders, detergents, water treatment agents, dispersants, fiber treatment agents, scale inhibitors (scale inhibitors), cement additives, metal ion sequestering agents, thickeners, various binders, etc.

[0061] The weight-average molecular weight of the ester bond-containing polycarboxylic acid (salt) of the present disclosure may be as low as an oligomer, without any problem in terms of excellent biodegradability and alkali decomposition rate. However, when used as a detergent builder for detergent compositions, the weight-average molecular weight is preferably 600 or more. The lower limit of the weight average molecular weight of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is not particularly limited, but for the purpose of improving the Ca ion trapping ability, it is preferably 1000 or more, more preferably 1500 or more, and even more preferably 3000 or more. The upper limit of the weight average molecular weight of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is not particularly limited, but it may be 1000000 or less, or may be 200000 or less. For the purpose of improving biodegradability, the molecular weight is preferably 80000 or less, more preferably 10000 or less, and even more preferably 3000 or less. The weight average molecular weight of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is preferably in the range of 1,000 to 1,000,000, more preferably 1,500 to 200,000, further preferably 1,500 to 80,000, and particularly preferably 3,000 to 10,000. In the present disclosure, the weight average molecular weight is a value measured by GPC (gel permeation chromatography), and can be measured using the apparatus and under the measurement conditions described in the Examples below.

[0062] The acid value of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is preferably 50 mg (KOH) / kg or more, more preferably 100 mg (KOH) / kg or more, and even more preferably 300 mg (KOH) / kg or more. If the acid value is in the above-mentioned range, it is preferable in that when added to a detergent, it can capture calcium in tap water and improve the detergency of the detergent. The hydroxyl value of the ester bond-containing polycarboxylic acid (salt) of the present disclosure is preferably 5 mg (KOH) / kg or more, more preferably 10 mg (KOH) / kg or more, and even more preferably 50 mg (KOH) / kg or more. If the hydroxyl value is within the above-mentioned range, it is preferable in terms of improving dispersibility in high-hardness water and compatibility with surfactants.

[0063] The biodegradability of the ester bond-containing polycarboxylic acid (salt) of the present disclosure can be measured by a biodegradability test described later, but a higher biodegradability is preferable because when the ester bond-containing polycarboxylic acid (salt) of the present disclosure is used in a detergent composition, the environmental load of the contaminated water after washing is reduced. The biodegradability is preferably 10% or more, more preferably 20% or more, even more preferably 50% or more, and most preferably 60% or more.

[0064] The alkali decomposition conversion rate of the ester bond-containing polycarboxylic acid (salt) of the present disclosure can be measured by an alkali decomposition conversion rate test described later, and a higher alkali decomposition conversion rate is preferable because it improves the efficiency of removing the ester bond-containing polycarboxylic acid (salt) of the present disclosure by alkaline washing. The alkali decomposition conversion rate is preferably 5% or more, more preferably 10% or more, and even more preferably 20% or more.

[0065] The Ca trapping ability of the ester bond-containing polycarboxylic acid (salt) of the present disclosure can be measured by the Ca trapping ability test described below. By improving the Ca trapping ability, when added to a detergent, it is possible to prevent the surfactant from being inactivated or insolubilized by Ca ions, and to significantly improve the cleaning power, or to significantly reduce the amount of surfactant used.

[0066] [Ester bond-containing polycarboxylic acid (salt) composition] The ester group-containing polycarboxylic acid (salt) composition of the present disclosure includes the ester group-containing polycarboxylic acid (salt) of the present disclosure. The ester group-containing polycarboxylic acid (salt) composition of the present disclosure may include components other than the ester group-containing polycarboxylic acid (salt) of the present disclosure. The ester group-containing polycarboxylic acid (salt) composition of the present disclosure is not particularly limited, but preferably contains the ester group-containing polycarboxylic acid (salt) of the present disclosure in an amount of 0.1 mass% or more and 100 mass% or less, more preferably 1 mass% or more and 99.5 mass% or less, based on 100 mass parts of the ester group-containing polycarboxylic acid (salt) composition of the present disclosure.

[0067] The ester group-containing polycarboxylic acid (salt) composition of the present disclosure may contain an esterification product of an unsaturated dicarboxylic acid and a compound containing two or more hydroxyl groups (hereinafter also referred to as "ester bond-containing carboxylic acid (salt)"). The content of the ester bond-containing carboxylic acid (salt) in the ester group-containing polycarboxylic acid (salt) composition of the present disclosure is preferably 20% by mass or less, more preferably 10% by mass or less, based on 100% by mass of the total of the ester group-containing polycarboxylic acid (salt) and the ester bond-containing carboxylic acid (salt) contained in the ester group-containing polycarboxylic acid (salt) composition of the present disclosure. When the content is within the above range, the anti-soil redeposition ability of the ester group-containing polycarboxylic acid (salt) composition of the present disclosure tends to be improved. The term "ester bond-containing carboxylic acid (salt)" refers to an ester of an unsaturated dicarboxylic acid and a compound containing two or more hydroxyl groups, which has not undergone a polymerization reaction.

[0068] [Method for producing ester bond-containing polycarboxylic acid (salt)] The method for producing the ester bond-containing polycarboxylic acid (salt) of the present disclosure is not particularly limited, and preferred examples include method (I) comprising step (A) of reacting a compound having an unsaturated double bond and an acid anhydride group with a compound having two or more hydroxyl groups, and step (B) of reacting the double bond of the product of the previous step, and method (II) comprising step (C) of reacting a compound having three or more carboxylic acids (salts) or an anhydride thereof with a compound having two or more hydroxyl groups. More preferred production methods include a method in which the reaction in the above step (A) or step (C) includes an esterification reaction, such as a method in which the steps are carried out in the order of 1) an esterification step of reacting a compound having an unsaturated double bond and an acid anhydride group with a compound having two or more hydroxyl groups, and 2) a step of reacting the double bond of the product obtained in the esterification step, or a method including a step of esterifying a compound having three or more carboxylic acids (salts) or an anhydride thereof with a compound having two or more hydroxyl groups.

[0069] The above-mentioned step (A) may be a step of reacting only a compound having an unsaturated double bond and an acid anhydride group with a compound having two or more hydroxyl groups, or may further include a compound other than these. Examples of the compound other than these include a compound having three or more carboxylic acids (salts) described later.

[0070] The compound having an unsaturated double bond and an acid anhydride group according to the present disclosure is not particularly limited as long as it has a double bond and an acid anhydride group, and examples thereof include maleic anhydride, citraconic anhydride, itaconic anhydride, phthalic anhydride, trimellitic anhydride, etc. Among these, it is preferable to use at least one selected from maleic anhydride and itaconic anhydride because of their high reactivity in the esterification step with a compound having two or more hydroxyl groups.

[0071] The compound having three or more carboxylic acids (salts) of the present disclosure is not particularly limited as long as it has three or more carboxylic acid (salt) groups. For example, oligomers of one or more compounds selected from compounds having an unsaturated double bond (more preferably a radically polymerizable unsaturated double bond) and a carboxylic acid (salt) group, such as acrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, methylene glutaric acid, methylene malonic acid, etc.; oligomers of one or more compounds selected from compounds having an anionically polymerizable carboxylic acid (salt) group, such as glyoxylic acid and methylene malonic acid; citric acid, 1,3,5-pentane tetracarboxylic acid, 1,2,3,4-butane tetracarboxylic acid, 1,2,3,4,5,6-cyclohexane hexacarboxylic acid, trimellitic acid, pyrometric acid, and salts thereof. Among these, 1,2,3,4-butanetetracarboxylic acid; oligomers of one or more compounds selected from maleic acid, itaconic acid, and salts and anhydrides thereof; and the like are preferred because of their high reactivity in the esterification step with a compound having two or more hydroxyl groups. The oligomer may be any oligomer that ultimately contains a carboxylic acid (salt) group. For example, the oligomer may be obtained by using an ester compound corresponding to a compound having a carboxylic acid (salt) group as a raw material to produce an oligomer, and then hydrolyzing the oligomer with a base or, if necessary, by adding a strong acid, converting the oligomer into an acid-type carboxy group.

[0072] The anhydride of a compound having three or more carboxylic acids (salts) of the present disclosure is not particularly limited as long as the substance obtained by hydrolyzing the compound has three or more carboxylic acid (salt) groups, and examples thereof include 1,3,5-pentanetetracarboxylic acid anhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid trianhydride, trimellitic anhydride, pyromellitic acid dianhydride, etc. Among these, 1,2,3,4-butanetetracarboxylic acid dianhydride is preferred because of its high reactivity in the esterification step with a compound having two or more hydroxyl groups. The compound having three or more carboxylic acids (salts) of the present disclosure preferably contains four or more carboxyl groups, in that the carboxylic acid density in the ester group-containing polycarboxylic acid (salt) increases and the calcium chelating ability and carbon black dispersibility can be maintained at high levels.

[0073] The compound having two or more hydroxyl groups in the present disclosure is not particularly limited as long as it is a compound having two or more hydroxyl groups, and may have three or four hydroxyl groups. Specific examples include branched or straight chain compounds such as ethylene glycol, propane-1,3-diol, butane-1,4-diol, heptane-1,5-diol, hexane-1,6-diol, propylene glycol, 1,3-butanediol, 1,4-pentanediol, and diethanolamine, chain compounds containing ether bonds such as diethylene glycol, triethylene glycol, and tetraethylene glycol, chain cyclic compounds having 3 to 10 carbon atoms such as cyclohexanediol, glycerin, 1,2,4-butanetriol, pentane-1,3,5-triol, 1,2,6-hexanetriol, and HO-CH 2 CH 2 CH(OH)CH2 CH 2 CH 2 Examples of the compound include a chain-like compound having three or more hydroxyl groups such as --OH. From the viewpoint of biodegradability and alkali decomposition rate, one or more compounds selected from ethylene glycol and glycerin are preferred.

[0074] <Esterification conditions> When carrying out the esterification reaction of the compound having an unsaturated double bond and an acid anhydride group of the present disclosure with a compound having two or more hydroxyl groups, the mixing ratio of the two is not particularly limited and can be reacted at any ratio. In order to increase the weight average molecular weight of the polymer made from the ester obtained by the esterification reaction, it is preferable to carry out the esterification reaction after charging the two compounds in a state where the molar ratio of the acid anhydride group and the hydroxyl group is close to equimolar. When an esterification reaction is carried out using a compound having a carboxylic acid (salt) other than the compound having an unsaturated double bond and an acid anhydride group, it is preferable to carry out the esterification reaction after charging the compounds in a state in which the total number of moles of the acid anhydride groups of the compound having an unsaturated double bond and an acid anhydride group and the total number of moles of the carboxyl groups of the compound having the carboxylic acid (salt) other than the compound are close to equimolar, and then the molar ratio of the hydroxyl groups is carried out.

[0075] In the above step (A), the ratio of the compound having two or more hydroxyl groups to the compound having an unsaturated double bond and an acid anhydride group is not particularly limited. In the case of a compound having two hydroxyl groups, the molar number of the hydroxyl groups contained therein is preferably 0.5 mol or more and 2.0 mol or less, and more preferably 0.7 mol or more and 1.5 mol or less, per 1 mol of the compound having an unsaturated double bond and an acid anhydride group. In the case of a compound having three hydroxyl groups, the number of moles of the hydroxyl groups contained therein is preferably 0.8 moles or more and 3 moles or less, and more preferably 1.0 moles or more and 2.2 moles or less. In the case of a compound having four or more hydroxyl groups, the number of moles of the hydroxyl groups contained therein is preferably 1.0 mole or more and 4.0 moles or less, and more preferably 1.4 moles or more and 3.0 moles or less. In the above case, the biodegradability and alkali decomposition rate of the ester bond-containing polycarboxylic acid (salt) tend to be improved.

[0076] In addition to the compound having an unsaturated double bond and an acid anhydride group, when an esterification reaction is carried out using a compound having a carboxylic acid (salt) other than the compound, the number of moles of the hydroxyl group contained in the compound having two hydroxyl groups is preferably 0.5 moles or more and 2.0 moles or less, more preferably 0.7 moles or more and 1.5 moles or less, relative to the total number of moles of the compound having an unsaturated double bond and an acid anhydride group and the carboxyl group of the compound having the carboxylic acid (salt) other than the compound having two hydroxyl groups. In the case of a compound having three hydroxyl groups, the number of moles of the hydroxyl group contained in the compound is preferably 0.8 moles or more and 3 moles or less, more preferably 1.0 moles or more and 2.2 moles or less. In the case of a compound having four or more hydroxyl groups, the number of moles of the hydroxyl group contained in the compound is preferably 1.0 moles or more and 4.0 moles or less, more preferably 1.4 moles or more and 3.0 moles or less.

[0077] When an esterification reaction is carried out using a compound having a carboxylic acid (salt) other than the compound having an unsaturated double bond and an acid anhydride group, it is preferable to use a compound having a carboxylic acid (salt) other than the compound having an unsaturated double bond and an acid anhydride group in a ratio of 0.1 to 7.0 moles of the carboxyl group of the compound having a carboxylic acid (salt) other than the compound having an unsaturated double bond and an acid anhydride group. More preferably, the ratio of 0.2 to 5.0 moles of the carboxyl group of the compound having a carboxylic acid (salt) other than the compound having an unsaturated double bond and an acid anhydride group, and even more preferably, the ratio of 0.3 to 3.0 moles.

[0078] In the above step (C), the ratio of the compound having two or more hydroxyl groups to the compound having three or more carboxylic acids (salts) or its anhydride is not particularly limited, but in the case of a compound having two hydroxyl groups, the molar number of the hydroxyl groups contained is preferably 0.5 mol or more and 2.0 mol or less, more preferably 0.8 mol or more and 1.5 mol or less, per 1 mol of a compound having three or more carboxylic acids (salts) or its anhydride. In the case of a compound having three hydroxyl groups, the molar number of the hydroxyl groups contained is preferably 0.8 mol or more and 3 mol or less, more preferably 1.0 mol or more and 2.2 mol or less. In the case of a compound having four or more hydroxyl groups, the molar number of the hydroxyl groups contained is preferably 1.0 mol or more and 4.0 mol or less, more preferably 1.4 mol or more and 3.0 mol or less. In the above case, the biodegradability and alkali decomposition rate of the ester bond-containing polycarboxylic acid (salt) tend to be improved.

[0079] The reaction temperature in the above step (A) or step (C) is not particularly limited, but is preferably 25° C. or higher, more preferably 50° C. or higher, and even more preferably 75° C. or higher. Also, it is preferably 200° C. or lower, more preferably 160° C. or lower, and even more preferably 150° C. or lower. The reaction temperature is preferably in the range of 25 to 200°C, more preferably 50 to 160°C, and further preferably 75 to 150°C. These preferred reaction temperatures also apply when the esterification reaction is carried out in step (A). In the above case, the biodegradability and alkali decomposition rate of the ester bond-containing polycarboxylic acid (salt) tend to be improved.

[0080] When the reaction in the above step (A) or step (C) includes an esterification reaction, a known esterification catalyst or esterification enzyme may be used. Examples of the esterification catalyst include a titanium-based esterification catalyst and a tin-based esterification catalyst.

[0081] <Polymerization conditions> The product obtained by carrying out an esterification reaction between the compound having an unsaturated double bond and an acid anhydride group of the present disclosure and the compound having two or more hydroxyl groups (hereinafter also referred to as an esterified product) is subjected to a polymerization reaction in the next step. In this case, other polymerizable monomers may be used. Specific examples of the other polymerizable monomers that can be preferably used include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, citraconic acid, allyl alcohol, isoprenol, allyl alcohol EO adduct, isoprenol EO adduct, acrylamide, sodium acrylamidopropanesulfonate, sodium 2-hydroxy-3-allyloxypropanesulfonate, hydroxyethyl acrylate, and hydroxyethyl methacrylate.

[0082] When reacting the esterified product of the present disclosure with other polymerizable monomers, the ratio of the product obtained by carrying out the esterification reaction of the compound having an unsaturated double bond and an acid anhydride group of the present disclosure with the compound having two or more hydroxyl groups to the other polymerizable monomers is not particularly limited, and can be polymerized at any ratio. If the molar ratio of the other polymerizable monomers is increased, the weight average molecular weight of the obtained ester bond-containing polycarboxylic acid (salt) of the present disclosure tends to be increased. On the other hand, if the ratio of the other polymerizable monomers is increased, biodegradability tends to be decreased. The ratio of the esterified product of the present disclosure to the other polymerizable monomer is not particularly limited, but examples include a form in which 0.05 to 5.0 moles, 0.1 to 3.0 moles, or 0.2 to 2.0 moles of the other polymerizable monomer are used per 1 mole of the esterified product of the present disclosure.

[0083] During the polymerization reaction, a compound having a hydroxyl group may be added. This allows the polymerization reaction and the esterification reaction between the carboxylic acid (salt) and the hydroxyl group of the resulting polymer to proceed. Examples of the compound having a hydroxyl group include the above-mentioned compounds having two or more hydroxyl groups.

[0084] When a compound having a hydroxyl group is added during the polymerization reaction, the ratio of the compound having a hydroxyl group to be added is preferably 0.05 to 2.0 mol, more preferably 0.08 to 1.5 mol, and even more preferably 0.1 to 1.3 mol, per mol of the esterified product of the present disclosure.

[0085] <Polymerization initiator> The polymerization initiator used in the above-mentioned production method can be one that is commonly used. Specifically, hydrogen peroxide; persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; azo compounds such as 2,2'-azobis(2-amidinopropane) hydrochloride, 4,4'-azobis-4-cyanovaleric acid, azobisisobutyronitrile, and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile); and organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, di-t-butyl peroxide, and cumene hydroperoxide are preferred. Among these polymerization initiators, hydrogen peroxide, persulfates, and 2,2'-azobis(2-amidinopropane) hydrochloride are preferred, and persulfates and 2,2'-azobis(2-amidinopropane) hydrochloride are more preferred. These polymerization initiators may be used alone or in combination of two or more. The polymerization initiator is preferably used in an amount of 0.5% by weight or more and 60% by weight or less with respect to the product obtained by carrying out an esterification reaction of a compound having an unsaturated double bond and an acid anhydride group according to the present disclosure, and a compound having two or more hydroxyl groups, in order to improve polymerization properties and reduce the amount of residual initiator remaining, more preferably 1.0% by weight or more and 50% by weight or less, and even more preferably 2.0% by weight or more and 30% by weight or less.

[0086] In the above-mentioned production method, an accelerator such as Mohr's salt may be used in combination with the polymerization initiator. When Mohr's salt is used, it is preferably used in an amount of 0.002% by weight or more and 0.05% by weight or less, and more preferably 0.003% by weight or more and 0.04% by weight or less, based on the product obtained by carrying out an esterification reaction of a compound having an unsaturated double bond and an acid anhydride group of the present disclosure with a compound having two or more hydroxyl groups, in order to improve polymerizability.

[0087] <Polymerization conditions> In the above-mentioned production method, the polymerization temperature is appropriately determined depending on the polymerization method, solvent, polymerization initiator, etc. used, but is preferably 25°C or higher. More preferably, it is 50°C or higher, even more preferably, it is 60°C or higher, and particularly preferably, it is 80°C or higher. Also, it is preferably 200°C or lower. More preferably, it is 150°C or lower, even more preferably, it is 120°C or lower, and particularly preferably, it is 110°C or lower. The polymerization temperature is preferably in the range of 25 to 200°C, more preferably 50 to 150°C, further preferably 60 to 120°C, and particularly preferably 80 to 110°C. The polymerization temperature does not need to be kept almost constant during the polymerization reaction. For example, the polymerization may be started from room temperature, the temperature may be raised to a set temperature at an appropriate temperature rise time or rate, and the set temperature may then be maintained. Alternatively, the temperature may be changed (raised or lowered) over time during the polymerization reaction depending on the method of dropping the monomer components, initiator, etc. The polymerization temperature refers to the temperature of the reaction solution in the polymerization reaction. Any appropriate method or means may be used for measuring or controlling the polymerization temperature. For example, it may be measured using a commonly used device.

[0088] The pressure during polymerization in the above-mentioned production method is not particularly limited, and any appropriate pressure can be adopted. For example, the pressure may be normal pressure (atmospheric pressure), reduced pressure, or increased pressure. The atmosphere in the reaction system may be air or an inert gas atmosphere. When the atmosphere in the reaction system is an inert gas atmosphere, the reaction system may be replaced with an inert gas such as nitrogen before the start of polymerization. This allows the atmospheric gas in the reaction system (e.g., oxygen gas) to dissolve in the liquid phase and act as a polymerization inhibitor.

[0089] In the above-mentioned production method, after the addition of all the raw materials has been completed, a maturation step may be carried out for the purpose of increasing the polymerization rate. In the above production method, the polymerization time is not particularly limited, but is preferably 20 to 420 minutes.

[0090] <Production of oligomers> The compound having three or more carboxylic acids (salts) or anhydrides thereof used in the above step (C) is not particularly limited, but an oligomer of one or more compounds selected from compounds having an unsaturated double bond and a carboxylic acid (salt) group can be used. The oligomer of one or more compounds selected from compounds having an unsaturated double bond and a carboxylic acid (salt) group used in the above step (C) (hereinafter also referred to as the oligomer of the present disclosure) is not particularly limited, and is produced, for example, by the following method.

[0091] As a raw material for the oligomer of the present disclosure, it is preferable to use one or more compounds selected from compounds having an unsaturated double bond and a carboxylic acid (salt) group, such as acrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, methylene glutaric acid, methylene malonic acid, etc. The oligomer of the present disclosure can use, as necessary, a monomer other than the compound having an unsaturated double bond and a carboxylic acid (salt) group as a raw material. Examples of other monomers include, but are not limited to, hydroxyl group-containing monomers such as allyl alcohol, methallyl alcohol, isoprenol, hydroxyethyl acrylate, and hydroxyethyl methacrylate; monomers having a structure in which an alkylene oxide is added to the above-mentioned hydroxyl group-containing monomers, for example, an ethylene oxide adduct of methallyl alcohol and an ethylene oxide adduct of isoprenol; amide group-containing monomers such as acrylamide and N-vinylpyrrolidone; sulfonic acid (salt) group-containing monomers such as sodium acrylamidopropanesulfonate and sodium 2-hydroxy-3-allyloxypropanesulfonate; and hydrophobic group-containing monomers such as ethyl acrylate and isobornyl acrylate.

[0092] The proportion of the compound having an unsaturated double bond and a carboxylic acid (salt) group relative to 100% by mass of the monomer used in the oligomer of the present disclosure is not particularly limited and may be used in any proportion, but is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, and even more preferably 80% by mass or more and 100% by mass or less.

[0093] The oligomer of the present disclosure is preferably produced by polymerizing a compound having an unsaturated double bond and a carboxylic acid (salt) group, and other monomers as necessary, in the presence of a polymerization initiator. Examples of the polymerization initiator include the polymerization initiators exemplified in the above section on <Polymerization initiator>.

[0094] The polymerization temperature and pressure conditions for producing the oligomer of the present disclosure are the same as those described above in the <Polymerization conditions> section. The oligomer of the present disclosure may be produced by adding all of the raw materials to a reactor at once, or by adding all or a part of the raw materials gradually or continuously. The oligomer of the present disclosure may be subjected to an aging step for the purpose of increasing the polymerization rate. In the above production method, the polymerization time is not particularly limited, but is preferably 20 to 420 minutes.

[0095] [Uses of ester bond-containing polycarboxylic acid (salt)] The ester bond-containing polycarboxylic acid (salt) of the present disclosure can be suitably used in detergent builders, detergents, water treatment agents, dispersants, fiber treatment agents, scale inhibitors (scale inhibitors), cement additives, metal ion sequestering agents, thickeners, various binders, etc. Among these, it can be suitably used in detergent builders, detergents, water treatment agents, and dispersants.

[0096] The present disclosure further relates to a detergent builder, detergent, water treatment agent, or dispersant that contains, as an essential component, the ester bond-containing polycarboxylic acid (salt) of the present disclosure, or the ester bond-containing polycarboxylic acid (salt) produced by the production method of the present disclosure.

[0097] <Detergent builders and detergent compositions> The detergent builder of the present disclosure acts to prevent dirt from re-adhering to clothes during washing. The copolymer (ester bond-containing polycarboxylic acid (salt)) of the present disclosure strongly disperses muddy dirt due to the charge repulsion of the carboxyl groups, and disperses detached muddy dirt to prevent it from re-adhering to clothes, thereby making it possible to further improve the whiteness of white clothes and significantly increase the added value of detergents. In addition, it has a high ability to disperse zeolite used in powder detergents, and is also highly effective as a dispersant when producing detergent powders. The detergent builder of the present disclosure has excellent compatibility with surfactants, and the resulting detergent is a highly concentrated liquid detergent, so it can be suitably used as a liquid detergent builder. The excellent compatibility with surfactants makes the builder excellent in transparency when used in a liquid detergent, and can prevent the problem of separation of the liquid detergent caused by turbidity. In addition, the excellent compatibility makes it possible to make a highly concentrated liquid detergent, and can improve the cleaning ability of the liquid detergent. The detergent builder of the present disclosure exhibits an excellent thickening effect when blended into a liquid detergent. Therefore, it has excellent handling properties because it suppresses dripping during use.

[0098] The detergent builder of the present disclosure has excellent anti-soil redeposition ability, and is furthermore resistant to deterioration in performance when stored for a long period of time and precipitation of impurities when kept at low temperatures, making it a detergent builder of extremely high quality and excellent in agent performance and stability.

[0099] The cleaning ability can be judged by the cleaning rate, which can be determined by the following method.

[0100] (Method of evaluating cleaning rate) Artificially soiled cloth is used as a sample. Cloth obtained from Scientific Services (STC GC C "clay soil", EMPA164 "grass soil", EMPA106 "carbon black / mineral oil soil") is used as the artificially soiled cloth, and the whiteness is measured in advance by reflectance. A colorimeter ND-1001DP (manufactured by Nippon Denshoku Industries Co., Ltd.) or the like can be used to measure the reflectance. Hard water is prepared by adding pure water to 1.47 g of calcium chloride dihydrate (0.74 g when using EMPA106 as the sample) to make up to 10 kg. Add 4.8g of sodium polyoxyethylene lauryl ether sulfate (AES), 0.6g of polyoxyethylene lauryl ether (AE), 0.6g of sodium borate, 0.9g of citric acid, and 2.4g of propylene glycol to pure water to make a total of 80g. After adjusting the pH to 8.2 with an aqueous sodium hydroxide solution, add pure water to make a total of 100g to prepare a surfactant aqueous solution. Set the tergotometer to 27°C, and place 1,000 mL of hard water, 5 mL of polymer aqueous solution (concentration 0.50% (concentration 0.60% if EMPA106 is used as the sample)), 10 mL of surfactant aqueous solution, and 5.4 g of artificially soiled cloth and 5.4 g of white cloth or 10.8 g of artificially soiled cloth only in the pot, and stir at 100 rpm for 10 minutes. The artificially soiled and white cloths are removed from the pot and the water is squeezed out by hand. 1000mL of hard water is added to the pot, and the squeezed out artificially soiled and white cloths are placed in the pot and stirred at 100 rpm for 2 minutes. The artificially soiled and white cloths are removed from the pot and the water is squeezed out by hand, after which a pressing cloth is placed over the artificially soiled cloth and dried while smoothing out any wrinkles with an iron. The whiteness of the dried artificially soiled cloth is measured by reflectance using a colorimeter. The cleaning rate (%) is calculated using the values ​​measured by the following method and the following formula. Cleaning power(%)= (Whiteness of artificially soiled cloth after washing - Whiteness of artificially soiled cloth before washing) ÷ (Whiteness of original white cloth (EMPA221) of artificially soiled cloth - Whiteness of artificially soiled cloth before washing) x 100

[0101] Regarding the above-mentioned cleaning rate, the present disclosure also includes a detergent builder, detergent, water treatment agent, or dispersant that is composed of a composition containing an ester bond-containing polycarboxylic acid (salt), and that has a cleaning rate of 7.3% or more when EMPA164 is used, or 17.4% or more when EMPA106 is used. Among compositions containing such ester bond-containing polycarboxylic acid (salt), i.e., detergent builders, detergents, water treatment agents, or dispersants, those that satisfy both of these two properties, i.e., the cleaning rate when EMPA164 is used and the cleaning rate when EMPA106 is used, are preferred. When EMPA164 is used, the cleaning rate is preferably 7.4% or more. When EMPA106 is used, the cleaning rate is preferably 17.5% or more, and more preferably 17.6% or more. The artificially soiled cloths EMPA164 and 106 used to measure the above cleaning rate are standard samples for soiling tests in which a certain amount of soil has been adhered to the cloth. EMPA164 is a white cotton cloth (EMPA221) soiled with grass, and EMPA106 is a white cotton cloth (EMPA221) soiled with carbon black and mineral oil.

[0102] As for the compositional components and blending ratios other than the ester bond-containing polycarboxylic acid (salt) in the above detergent builder, various components that can be used in conventionally known detergent builders and their blending ratios can be appropriately used within a range that does not impair the action and effect of the present disclosure.

[0103] The detergent may be either a powder detergent or a liquid detergent, but a liquid detergent is preferred because the ester bond-containing polycarboxylic acid (salt) has excellent solubility in liquid detergents. In addition to the ester bond-containing polycarboxylic acid (salt), additives that are usually used in detergents can be used in the detergent. Suitable additives include, for example, surfactants, alkali builders, chelate builders, redeposition inhibitors for preventing redeposition of contaminants such as sodium carboxymethylcellulose, stain inhibitors such as benzotriazole and ethylene-thiourea, soil release agents, color transfer inhibitors, fabric softeners, alkaline substances for adjusting pH, fragrances, solubilizers, fluorescent agents, colorants, foaming agents, foam stabilizers, polishing agents, bactericides, bleaching agents, bleaching aids, enzymes, dyes, solvents, etc. In the case of powder detergents, it is preferable to add zeolite.

[0104] When used in the above-mentioned detergents, the ester bond-containing polycarboxylic acid (salt) of the present disclosure is preferably added in an amount of 0.1 to 20% by mass relative to 100% by mass of the detergent. If the amount is less than 0.1% by mass, the cleaning power of the detergent may be insufficient, and if the amount is more than 20% by mass, the detergent may become uneconomical.

[0105] The above detergents include synthetic detergents for household use, detergents for the textile and other industrial uses, and hard surface cleaners, as well as detergents used for specific purposes only, such as bleaching detergents, which enhance the function of one of their ingredients.

[0106] The surfactant is at least one selected from anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric surfactants, and these surfactants can be used alone or in combination. When using two or more kinds, it is preferable to include an anionic surfactant and a nonionic surfactant among them. In that case, the total amount of the anionic surfactant and the nonionic surfactant used is preferably 50% by mass or more based on 100% by mass of all the surfactants. More preferably, it is 60% by mass or more, still more preferably, it is 70% by mass or more, and particularly preferably, it is 80% by mass or more.

[0107] Examples of the above anionic surfactant include alkylbenzene sulfonates, alkyl ether sulfates, alkenyl ether sulfates, alkyl sulfates, alkenyl sulfates, α-olefin sulfonates, α-sulfo fatty acids or ester salts, alkane sulfonates, saturated fatty acid salts, unsaturated fatty acid salts, alkyl ether carboxylates, alkenyl ether carboxylates, amino acid type surfactants, N-acyl amino acid type surfactants, alkyl phosphate esters or their salts, alkenyl phosphate esters or their salts, etc. The alkyl group and alkenyl group in the above anionic surfactant may have a branched alkyl group such as a methyl group.

[0108] Examples of the above nonionic surfactant include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyethylene alkyl phenyl ethers, higher fatty acid alkanolamides or their alkylene oxide adducts, sucrose fatty acid esters, alkyl glycodides, fatty acid glycerin monoesters, alkyl amine oxides, etc. The alkyl group and alkenyl group in the above nonionic surfactant may have a branched alkyl group such as a methyl group. Examples of the above cationic surfactant include quaternary ammonium salts, etc. Examples of the above amphoteric surfactant include carboxyl type amphoteric surfactants, sulfobetaine type amphoteric surfactants, etc. The alkyl group and alkenyl group in the above cationic surfactant and amphoteric surfactant may have a branched alkyl group such as a methyl group.

[0109] The blending ratio of the surfactant is usually preferably 10 to 60% by mass relative to 100% by mass of the liquid detergent. More preferably, it is 15% by mass or more and 50% by mass or less, even more preferably, it is 20% by mass or more and 45% by mass or less, and particularly preferably, it is 25% by mass or more and 40% by mass or less. If the blending ratio of the surfactant is less than 10% by mass, there is a risk that sufficient detergency cannot be exhibited, and if it exceeds 60% by mass, there is a risk that the economical efficiency decreases. When two or more types of surfactants are used, the total blending ratio of the two or more types of surfactants is preferably as described above.

[0110] The blending ratio of the liquid detergent builder is usually preferably 0.1 to 20% by mass relative to 100% by mass of the liquid detergent. More preferably, it is 0.2% by mass or more and 15% by mass or less, even more preferably, it is 0.3% by mass or more and 10% by mass or less, particularly preferably, it is 0.4% by mass or more and 8% by mass or less, and most preferably, it is 0.5% by mass or more and 5% by mass or less. If the blending ratio of the liquid detergent builder is less than 0.1% by mass, the detergent performance may not be sufficient, and if it exceeds 20% by mass, the economical efficiency may decrease.

[0111] The water content in the liquid detergent is preferably 0.1 to 75% by mass relative to 100% by mass of the liquid detergent, more preferably 0.2% by mass or more and 70% by mass or less, even more preferably 0.5% by mass or more and 65% by mass or less, particularly preferably 0.7% by mass or more and 60% by mass or less, even more particularly preferably 1% by mass or more and 55% by mass or less, and most preferably 1.5% by mass or more and 50% by mass or less.

[0112] The liquid detergent preferably has a kaolin turbidity of 200 mg / L or less, more preferably 150 mg / L or less, even more preferably 120 mg / L or less, particularly preferably 100 mg / L or less, and most preferably 50 mg / L or less.

[0113] In addition, the change (difference) in kaolin turbidity when the ester bond-containing polycarboxylic acid (salt) of the present disclosure is added to the liquid detergent and when it is not added is preferably 500 mg / L or less. More preferably, it is 400 mg / L or less, still more preferably, it is 300 mg / L or less, particularly preferably, it is 200 mg / L or less, and most preferably, it is 100 mg / L or less. The kaolin turbidity can be measured by the following method.

[0114] (Method for measuring kaolin turbidity) Charge a uniformly stirred sample (liquid detergent) into a 50 mm square cell with a thickness of 10 mm. After removing bubbles, measure the Turbidity (kaolin turbidity: mg / L) at 25°C using NDH2000 (trade name, turbidimeter) manufactured by Nippon Denshoku Industries Co., Ltd.

[0115] As the enzyme that can be incorporated into the detergent of the present disclosure, protease, lipase, cellulase, etc. are suitable. Among them, protease, alkaline lipase, and alkaline cellulase with high activity in an alkaline cleaning solution are preferred. The addition amount of the above enzyme is preferably 5% by mass or less based on 100% by mass of the detergent. If it exceeds 5% by mass, the improvement in detergency may not be observed, and the economy may decrease.

[0116] As the above alkaline builder, silicate, carbonate, sulfate, etc. are suitable. As the above chelating builder, diglycolic acid, oxycarboxylic acid, EDTA (ethylenediaminetetraacetic acid), DTPA (diethylenetriaminepentaacetic acid), citric acid, MGDA (methylglycinediacetic acid), HIDS (hydroxyiminodiacetic acid), etc. are suitable. A water-soluble polycarboxylic acid-based polymer may also be used.

[0117] The above detergent can be made into a detergent with extremely high-quality agent performance that is excellent in dispersibility, and further has excellent stability in that performance degradation during long-term storage and precipitation of impurities during storage at low temperature hardly occur.

[0118] <Water treatment agent> The compound of the present disclosure (the ester bond-containing polycarboxylic acid (salt) of the present disclosure) can be used in a water treatment agent. The water treatment agent may contain other additives such as polymerized phosphates, phosphonates, anticorrosive agents, slime control agents, and chelating agents, if necessary.

[0119] The water treatment agent is useful for preventing scale formation in cooling water circulation systems, boiler water circulation systems, seawater desalination plants, pulp digesters, black liquor concentration pots, etc. In addition, the water treatment agent may contain any appropriate water-soluble polymer as long as it does not affect the performance and effect.

[0120] <Textile treatment agent> The compound of the present disclosure can be used in a fiber treatment agent, which contains at least one selected from the group consisting of a dye, a peroxide, and a surfactant, and the polymer (or polymer composition) of the present disclosure.

[0121] The content of the compound of the present disclosure in the fiber treatment agent is preferably 1 to 100% by weight, more preferably 5 to 100% by weight, based on the total weight of the fiber treatment agent. In addition, the fiber treatment agent may contain any appropriate water-soluble compound within a range that does not affect the performance and effect.

[0122] The following is an example of a fiber treatment formulation that is closer to the embodiment. This fiber treatment can be used in the refining, dyeing, bleaching, and soaping processes in fiber treatment. The dyes, peroxides, and surfactants include those that are commonly used in fiber treatments.

[0123] Regarding the blending ratio of the ester bond-containing polycarboxylic acid (salt) of the present disclosure to at least one selected from the group consisting of dyes, peroxides, and surfactants, for example, in order to improve the whiteness, color unevenness, and dye waxiness of fibers, it is preferable to use a composition in which at least one selected from the group consisting of dyes, peroxides, and surfactants is blended in a ratio of 0.1 to 100 parts by weight per part by weight of the compound of the present disclosure, calculated as the pure content of the fiber treatment agent, as a fiber treatment agent.

[0124] As the fibers to which the above fiber treatment agent can be applied, any suitable fibers can be adopted. For example, cellulose fibers such as cotton and hemp, chemical fibers such as nylon and polyester, animal fibers such as wool and silk yarn, semi-synthetic fibers such as rayon, and their woven fabrics and blends can be mentioned.

[0125] When applying the above fiber treatment agent to the refining process, it is preferable to blend the compound of the present disclosure with an alkaline agent and a surfactant. When applying it to the bleaching process, it is preferable to blend the compound of the present disclosure with a peroxide and a silicate agent such as sodium silicate as a decomposition inhibitor of the alkaline bleaching agent.

[0126] <Inorganic Pigment Dispersant> The compound of the present disclosure can be used as an inorganic pigment dispersant. For the inorganic pigment dispersant, condensed phosphoric acid and its salts, phosphonic acid and its salts, and polyvinyl alcohol may be used as other compounding agents, if necessary.

[0127] The content of the compound of the present disclosure in the above inorganic pigment dispersant is preferably 5 to 100% by weight based on the total amount of the inorganic pigment dispersant. Also, within a range that does not affect the performance and effects, any suitable water-soluble compound may be included.

[0128] The above inorganic pigment dispersant can exhibit good performance as a dispersant for heavy or light calcium carbonate and clay inorganic pigments used in paper coating. For example, by adding a small amount of the inorganic pigment dispersant to the inorganic pigment and dispersing it in water, a high-concentration inorganic pigment slurry such as a high-concentration calcium carbonate slurry with low viscosity, high fluidity, and good long-term stability of those properties can be produced.

[0129] When using the above inorganic pigment dispersant as a dispersant for inorganic pigments, the usage amount of the inorganic pigment dispersant is preferably 0.05 to 2.0 parts by weight based on 100 parts by weight of the inorganic pigment. When the usage amount of the inorganic pigment dispersant is within the above range, it becomes possible to obtain a sufficient dispersion effect, obtain an effect commensurate with the added amount, and be economically advantageous. EXAMPLES

[0130] <Biodegradability test> The biodegradability test of the obtained ester bond-containing polycarboxylic acid (salt) was carried out in accordance with OECD301F. (1) Preparation of medium: Stock medium solutions A to D were prepared by the following method. Solution A: Potassium dihydrogen phosphate (KH 2 PO 4 ) 0.850g, dipotassium hydrogen phosphate (K 2 HPO 4 ) 2.175g, disodium hydrogen phosphate dodecahydrate (Na 2 HPO 4 12H 2 O) 6.7217g, Ammonium chloride (NH 4 Cl) 0.050 g was weighed into a 50 ml sample bottle, dissolved in an appropriate amount of water and transferred to a 100 ml measuring flask, and then water was added up to the marked line. Solution B: Calcium chloride dihydrate (CaCl 2 2H 2 O) 3.640 g was dissolved in an appropriate amount of water and transferred to a 100 ml measuring flask, and then water was added up to the mark. Solution C: Magnesium sulfate heptahydrate (MgSO 4 7H 2 O) 2.250 g was dissolved in an appropriate amount of water and transferred to a 100 ml measuring flask, and then water was added up to the mark. Solution D: Iron(III) chloride hexahydrate (FeCl 3 6H 2 O) 0.025 g was dissolved in an appropriate amount of water and transferred to a 100 ml measuring flask, and water was then added up to the mark. The above stock medium solutions A to D were adjusted to 25°C, and 10 ml of A was placed in a 1L measuring flask using a whole pipette and diluted with approximately 800 ml of water. Then, 1 ml each of B, C, and D was added using a whole pipette and diluted to the mark with water adjusted to 25°C. Multiple portions of the above medium were prepared according to the amount required for the test. The prepared medium was transferred to a 5L beaker, mixed, and bubbled for more than 1 hour while stirring. (2) Preparation of sludge solution: The sludge used in the biodegradability test was obtained from Minami Suita Sewage Treatment Plant. First, the concentration of the obtained sludge was measured by the following method. The obtained sludge was bubbled while stirring, 5 ml was taken using a whole pipette, and suction filtered using filter paper. Five sheets of filter paper on which the sludge was collected in this way were prepared, and after drying at 105°C for 1 hour in a dryer, the concentration of the sludge was calculated from the average weight loss of the five sheets. This sludge was diluted with the medium prepared above to prepare a 1000 ppm sludge solution. (3) Preparation of polymer aqueous solution: The polymer obtained in each example was diluted with pure water to obtain a 2% by mass aqueous polymer solution. As a standard substance, sodium benzoate was diluted with pure water to obtain a 2% by mass aqueous sodium benzoate solution.

[0131] BOD Testing: A pressure sensor type BOD meter was used to measure the BOD. 144.75 g of the medium prepared above was weighed into a stir bottle, and 0.75 g of a 2% polymer aqueous solution was added. For the blank measurement, 0.75 g of pure water was added, and for the standard substance measurement, 0.75 g of a 2% sodium benzoate aqueous solution was added. The pH of the solution was then measured, and the pH was adjusted to 7.4 ± 0.2 with a 0.1 M hydrochloric acid aqueous solution. 4.5 ml of a 1000 ppm sludge solution was then added to prepare the test solution. A stir bar was placed in the stir bottle, and CO was added to the stir bottle. 2 CO in the absorbent holder 2 1.8g of absorbent (Yabashiri lime) was added and set, and a BOD sensor was attached. The flask with the BOD sensor attached was stirred in a thermostatic bath at 24°C, and the BOD value was calculated from the pressure sensor.

[0132] Calculation of decomposition rate: The theoretical oxygen demand (ppm) of the polymer was calculated, and the decomposition rate was calculated from the difference between the BOD value of the blank measurement and the BOD value of the ester-bond-containing polycarboxylic acid (salt) measurement. The decomposition rate 28 days after the start of the test was regarded as the biodegradation rate. Decomposition rate (%) = (biochemical oxygen consumption from polymer) / (theoretical oxygen demand of polymer) x 100

[0133] <Alkaline decomposition rate of change> The pH of the ester group-containing polymer (ester bond-containing polycarboxylic acid (salt)) was set to 13 or higher, 48% NaOH was added, and heating was carried out at 90 °C for 5 hours to perform alkaline decomposition. The weight-average molecular weight before and after alkaline decomposition was measured under the following weight-average molecular weight conditions, and the rate of change was taken as the alkaline decomposition rate of change. Alkaline decomposition rate of change (%) = (weight-average molecular weight before alkaline decomposition - weight-average molecular weight after alkaline decomposition) / (weight-average molecular weight before alkaline decomposition) × 100

[0134] <Weight-average molecular weight measurement conditions> Apparatus: HLC-8320GPC manufactured by Tosoh Corporation Detector: RI Column: Tsk-gel G-3000SWXL × 2 Column temperature: 40 °C Flow rate: 0.5 mL / min. Calibration curve: Polyacrylic acid standard manufactured by American Polymer Standards Eluent: 80 mM phosphate buffer

[0135] <Ca capture ability measurement conditions> As a calcium ion standard solution for the calibration curve, using calcium chloride dihydrate, 50 g of aqueous solutions of 0.01 mol / L, 0.001 mol / L, and 0.0001 mol / L were prepared, adjusted to a pH range of 9.5 to 10.5 with a 1.0% NaOH aqueous solution, and further 1 mL of a 4 mol / L potassium chloride aqueous solution (hereinafter abbreviated as 4M-KCl aqueous solution) was added, and further sufficiently stirred using a magnetic stirrer to prepare a sample solution for the calibration curve. Also, as a calcium ion standard solution for the test, using the same calcium chloride dihydrate, an aqueous solution of 0.001 mol / L was prepared in a required amount (50 g per sample). Next, 10 mg of the test sample (ester bond-containing polycarboxylic acid (salt)) was weighed out in a 100 mL beaker in terms of solid content, 50 g of the above calcium ion standard solution for testing was added, and the mixture was thoroughly stirred using a magnetic stirrer. Next, similar to the calibration curve sample, the pH was adjusted to 9.5 to 10.5 with 1.0% sodium hydroxide aqueous solution, and 1 mL of 4M-KCl aqueous solution was added to prepare the test sample solution. The thus prepared calibration curve sample solution and test sample solution were measured using a titration device COM-1700 manufactured by Hiranuma Sangyo Co., Ltd. and an Orion 9720BNWP Sure-Flow calcium composite electrode manufactured by Thermo Fisher Scientific Co., Ltd. A calibration curve of Ca ion molar concentration was created from the measured values ​​of the calibration curve sample solution, and the Ca ion molar concentration of the sample solution was calculated using the calibration curve from the measured values ​​of the test sample solution. The Ca capture ability was calculated using the following formula. Ca capture capacity of sample liquid = (0.001 - Ca ion molar concentration of sample (mol / L)) / 0.01 x 100 x 50 / 1000 x 1000

[0136] <Mud dispersion test> (1) Preparation of glycine buffer (67.56 g of glycine, 52.60 g of sodium chloride, 5.00 g of 48% sodium hydroxide, and add purified water to make 600 g. (2) Preparation of dispersion buffer solution (Ca / Mg=3 / 1 mol, 100 ppm in test solution) (60 g of glycine buffer, 0.123 g of calcium chloride dihydrate, 0.056 g of magnesium chloride hydrate, and add pure water to make 1000 g. (3) Prepare a 0.10% aqueous solution of an ester bond-containing polycarboxylic acid. (4) Place 0.3 g of JIS type 11 clay in a test tube, add 27.0 g of glycine buffer (2) and 3.0 g of a 0.10% aqueous solution of ester bond-containing polycarboxylic acid (3), and then close the tube. (5) After loosening the clay that has accumulated at the bottom, invert the test tube up and down 60 times. (6) Remove the lid from the test tube, cover the top with plastic wrap, and leave it in a stable place for 20 hours. (7) Collect 5 cc from the upper 5 cm portion of the test tube and measure the ABS (absorbance) at UV 380 nm as the value of the mud dispersibility test. The higher the numerical value of the mud dispersibility test, the higher the mud dispersibility and the higher the cleaning power of mud stains.

[0137] <Carbon black dispersibility test> (1) Prepare a 5.0% aqueous solution of polycarboxylic acid containing an ester bond. (2) Put 0.1 g of Mitsubishi Chemical carbon black #10 into a test tube, add 9 g of ion-exchanged water and 1.0 g of the 5.0% aqueous solution of polycarboxylic acid containing an ester bond prepared in (1), and cover with a lid. (3) After loosening the carbon black accumulated at the bottom, invert the test tube up and down 60 times. (4) Remove the lid of the test tube, cover the upper part with plastic wrap, and let it stand in a stable place for 4 hours. (5) Observe the dispersion liquid after standing and make a judgment according to the following criteria. [Criteria] Well dispersed: ◎ Somewhat dispersed: 〇 Almost not dispersed: × The better the dispersibility of carbon black, the higher the cleaning power of composite stains containing oil stains.

[0138] <NMR measurement conditions> Under the following conditions, 1 1H-NMR was measured. Instrument name: Varian VNMRS600 Measurement conditions: Nucleus: 1 H Resonance frequency: 600 MHz Signal acquisition time: 3.4 seconds Delay time: 5 seconds Number of integrations: 128 times Solvent: D 2 O Sample concentration: 10% The measurement materials were dried under reduced pressure until dry and then dissolved in the measurement solvent for measurement.

[0139] <Example 1> (Esterification process) 90 parts of ethylene glycol and 213.3 parts of maleic anhydride were charged into a 2 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the temperature was raised to 120°C with stirring, and then heating and stirring were carried out at 120°C for 60 minutes. (Polymerization process) After the esterification step, 150 parts of pure water was added, and while stirring under reflux at the boiling point (about 105-101°C), 90 parts of a 15% aqueous solution of sodium persulfate and 150 parts of a 35% aqueous solution of hydrogen peroxide were continuously dropped at a constant rate from separate feed lines over a period of 60 minutes. Then, under reflux at the boiling point, maturation was carried out for 60 minutes. After maturation, the temperature was lowered to obtain an ester bond-containing polycarboxylic acid (1) with a solid content of 44%. The molecular weight of the obtained ester group-containing polycarboxylic acid (1) was measured by aqueous GPC. The Ca trapping ability, biodegradability (based on OECD301F) and change in molecular weight after alkali decomposition were also measured. The results are shown in Table 1.

[0140] <Example 2> (Esterification process) 90 parts of ethylene glycol and 284.4 parts of maleic anhydride were charged into a 2 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the temperature was raised to 120°C with stirring, and then heating and stirring were carried out at 120°C for 60 minutes. (Polymerization process) After the esterification step was completed, 120 parts of pure water was added, and while stirring under reflux at the boiling point (about 105-101°C), 60 parts of a 15% aqueous solution of sodium persulfate, 150 parts of a 35% aqueous solution of hydrogen peroxide, and 42 parts of an 80% aqueous solution of acrylic acid were continuously dropped at a constant rate from separate feed lines over a period of 60 minutes. Then, under reflux at the boiling point, maturation was carried out for 60 minutes. After maturation, the temperature was lowered to obtain an ester bond-containing polycarboxylic acid (2) with a solid content of 55%. The physical properties were measured in the same manner as in Example 1, and the results are shown in Table 1.

[0141] <Example 3> (Esterification process) 90 parts of ethylene glycol and 284.4 parts of maleic anhydride were charged into a 2 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the temperature was raised to 120°C with stirring, and then heating and stirring were carried out at 120°C for 60 minutes. (Polymerization process) After the esterification step, 60 parts of a 15% aqueous solution of sodium persulfate, 210 parts of a 35% aqueous solution of hydrogen peroxide, and 42 parts of an 80% aqueous solution of acrylic acid were continuously added dropwise at a constant rate over 60 minutes from separate input lines while stirring under reflux at the boiling point (about 105-101°C). Then, aging was carried out for 60 minutes under reflux at the boiling point. After aging, the temperature was lowered, and 300 parts of pure water were added to obtain an ester bond-containing polycarboxylic acid (3) with a solid content of 42%. The physical properties were measured in the same manner as in Example 1, and the results are shown in Table 1.

[0142] <Example 4> (Esterification process) 90 parts of ethylene glycol and 284.4 parts of maleic anhydride were charged into a 2 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the temperature was raised to 120°C with stirring, and then heating and stirring were carried out at 120°C for 60 minutes. (Polymerization process) After the esterification step, 60 parts of a 15% aqueous solution of sodium persulfate, 210 parts of a 35% aqueous solution of hydrogen peroxide, and 84 parts of an 80% aqueous solution of acrylic acid were continuously dropped at a constant rate over 60 minutes from separate feed lines while stirring under reflux at the boiling point (about 105-101°C). Then, aging was carried out for 60 minutes under reflux at the boiling point. After aging, the temperature was lowered, and 150 parts of pure water were added to obtain an ester bond-containing polycarboxylic acid (4) with a solid content of 50%. The proton NMR chart of the obtained ester bond-containing polycarboxylic acid (4) is shown in Figure 1. The physical properties were measured in the same manner as in Example 1, and the results are shown in Table 1.

[0143] <Example 5> (Esterification process) 90 parts of glycerin and 219 parts of itaconic anhydride were placed in a 2 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the mixture was heated to 70°C with stirring, and then heated and stirred at 70°C for 60 minutes. (Polymerization process) After the esterification step was completed, 300 parts of pure water was added, and while stirring at 95°C, 39 parts of a 10% aqueous solution of sodium persulfate and 97.5 parts of a 10% aqueous solution of sodium bisulfite were continuously added dropwise at a constant rate from separate feed lines over a period of 60 minutes. Then, the mixture was aged for 60 minutes under boiling point reflux. After aging, the temperature was lowered to obtain an ester bond-containing polycarboxylic acid (5) with a solid content of 42%. The physical properties were measured in the same manner as in Example 1, and the results are shown in Table 1.

[0144] <Example 6> (Esterification process) 90 parts of ethylene glycol and 150 parts of itaconic anhydride were charged into a 2 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the temperature was raised to 120°C with stirring, and then heating and stirring were carried out at 120°C for 60 minutes. (Polymerization process) After the esterification step, 600 parts of pure water was added, and while stirring at 95°C, 60 parts of a 15% aqueous solution of sodium persulfate and 210 parts of a 30% aqueous solution of sodium bisulfite were continuously added dropwise at a constant rate from separate feed lines over a period of 60 minutes. Then, the mixture was aged for 60 minutes under boiling point reflux. After aging, the temperature was lowered, and 300 g of pure water was added to obtain an ester bond-containing polycarboxylic acid (6) with a solid content of 27%. The physical properties were measured in the same manner as in Example 1, and the results are shown in Table 1.

[0145] [Table 1]

[0146] Alkaline decomposition change rate: (Molecular weight before decomposition - molecular weight after alkaline decomposition) / Molecular weight before decomposition x 100 The alkaline decomposition was carried out by adjusting the pH of the ester group-containing polycarboxylic acid of each Example to 13 by addition of NaOH and subjecting it to heat treatment at 100° C. for 3 hours. Ca capture capacity: The amount of Ca captured by 1 g of polymer solids (CaCO 3 (calculated as mg) Mud dispersion test: The ability to disperse muddy dirt was measured. The higher the value, the higher the dispersion ability, and the better the cleaning power for muddy dirt when added to a detergent.

[0147] <Comparative Example> As a comparative example, sodium polyacrylate having a molecular weight of 2500 (comparative polycarboxylic acid (C-1)) was used and the physical properties were measured in the same manner as in Example 1. The results are shown in Table 2.

[0148] [Table 2]

[0149] <Example 7> (Esterification process) 35 parts of ethylene glycol and 94.8 parts of maleic anhydride were charged into a 1 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the mixture was heated to 120°C with stirring, and then heated and stirred at 120°C for 60 minutes. (Polymerization process) After the esterification step was completed, 2 parts of a 1.8% aqueous solution of Mohr's salt was added, and while stirring under reflux at the boiling point (about 120-135°C), 12 parts of diethanolamine, 70 parts of a 35% aqueous solution of hydrogen peroxide, and 28 parts of an 80% aqueous solution of acrylic acid were continuously dropped at a constant rate from separate feed lines over a period of 120 minutes. Then, under reflux at the boiling point, maturation was carried out for 30 minutes. After maturation, the temperature was lowered to obtain an ester bond-containing polycarboxylic acid (7) with a solid content of 44%. The molecular weight of the obtained ester group-containing polycarboxylic acid (7) was measured by aqueous GPC. The Ca trapping ability, biodegradability (based on OECD301F) and change in molecular weight after alkali decomposition were also measured. The results are shown in Table 3. In addition, when evaluating the Ca-capturing ability of the ester group-containing polycarboxylic acid (7), it was 160 mgCaCO 3 / g, and when evaluating biodegradability (conforming to OECD301F), it was 55%.

[0150] <Example 8> (Esterification step) Into a 1 L-capacity reaction kettle made of SUS316L equipped with a stirrer and a reflux condenser, 21.7 parts of ethylene glycol, 66.4 parts of maleic anhydride, and 10.5 parts of Softanol 60 (secondary alcohol EO6 mol adduct, manufactured by Nippon Shokubai Co., Ltd.) were charged. After heating to 120 °C with stirring, heating and stirring were carried out at 120 °C for 60 minutes. (Polymerization step) After the completion of the esterification step, 1.4 parts of a 1.8% aqueous solution of mol salt was charged. While stirring under reflux at the boiling point (about 120 - 135 °C), 16.8 parts of diethanolamine, 56 parts of a 35% aqueous solution of hydrogen peroxide, and 19.6 parts of an 80% aqueous solution of acrylic acid were continuously dropped at a constant rate from individual charging lines over 120 minutes. Thereafter, aging was carried out for 30 minutes under reflux at the boiling point. After aging, the temperature was lowered, and 300 parts of pure water was charged to obtain an ester bond-containing polycarboxylic acid (8) with a solid content of 42%. Physical property measurements were carried out in the same manner as in Example 1, and the results are shown in Table 3.

[0151] <Example 9> (Esterification step) Into a 2 L-capacity reaction kettle made of SUS316L equipped with a stirrer and a Dean-Stark tube for dehydration, 34.3 parts of ethylene glycol, 164 parts of 1,2,3,4-butanetetracarboxylic dianhydride, 2.26 parts of a 70% aqueous solution of p-toluenesulfonic acid, and 300 parts of water were charged. The temperature was raised with stirring to proceed with dehydration, and after the internal temperature reached 150 °C, heating and stirring were continued for 60 minutes. (Neutralization step) After the esterification step was completed, the temperature was lowered to 60° C., and the entire amount of a solution prepared by dissolving 87.5 parts of sodium carbonate in 374 parts of pure water was added and stirred for 30 minutes, followed by bubbling with nitrogen at a flow rate of 100 mL / min to obtain an ester bond-containing polycarboxylic acid (9) with a solid content of 40%. The molecular weight of the resulting ester group-containing polycarboxylic acid (number) was measured by aqueous GPC. The Ca trapping ability, biodegradability (based on OECD301F), and change in molecular weight after alkali decomposition were also measured. The results are shown in Table 3.

[0152] <Example 10> (Polymerization process) 125 parts of water, 155 parts of maleic acid, and 70.2 parts of 0.1% Mohr's salt solution were charged into a 2L SUS316L reaction vessel equipped with a stirrer and reflux condenser, and the mixture was heated to 100°C with stirring. While maintaining the temperature, a mixture of 129 parts of 35% hydrogen peroxide and 20.6 parts of water was added dropwise to the vessel at a constant rate over 4 hours. After the addition was completed, the mixture was left to mature for 30 minutes and then cooled to room temperature. (Esterification process) The entire reaction liquid and 16.6 parts of ethylene glycol were added to a 2 L SUS316L reaction vessel equipped with a stirrer and a Dean-Stark tube for dehydration, and the temperature was raised with stirring to proceed with dehydration. After the internal temperature reached 150°C, heating and stirring were continued for 60 minutes. (neutralization process) After the esterification step was completed, the temperature was lowered to 60° C., and the entire amount of a solution prepared by dissolving 70.6 parts of sodium carbonate in 387 parts of pure water was added and stirred for 30 minutes, followed by bubbling with nitrogen at a flow rate of 100 mL / min to obtain an ester bond-containing polycarboxylic acid (10) with a solid content of 40%. The molecular weight of the resulting ester group-containing polycarboxylic acid (number) was measured by aqueous GPC. The Ca trapping ability, biodegradability (based on OECD301F), and change in molecular weight after alkali decomposition were also measured. The results are shown in Table 3. Furthermore, when the biodegradability (based on OECD301F) of the ester group-containing polycarboxylic acid (10) was evaluated, it was found to be 22%.

[0153] <Example 11> (Polymerization process) 102 parts of water, 131 parts of itaconic acid, and 70.1 parts of 0.1% Mohr's salt solution were charged into a 2L SUS316L reaction vessel equipped with a stirrer and reflux condenser, and the mixture was heated to 100°C with stirring. While maintaining the temperature, 197 parts of 35% hydrogen peroxide solution were added dropwise to the vessel at a constant rate over 4 hours. After the addition was completed, the mixture was aged for 30 minutes and then cooled to room temperature. (Esterification process) The entire reaction liquid, 21.3 parts of ethylene glycol, and 2.60 parts of a 70% aqueous p-toluenesulfonic acid solution were added to a 2 L SUS316L reaction kettle equipped with a stirrer and a Dean-Stark tube for dehydration, and the temperature was raised with stirring to proceed with dehydration. After the internal temperature reached 150°C, heating and stirring were continued for 60 minutes. (neutralization process) After the esterification step was completed, the temperature was lowered to 60° C., and the entire amount of a solution prepared by dissolving 53.3 parts of sodium carbonate in 379 parts of pure water was added and stirred for 30 minutes, followed by bubbling with nitrogen at a flow rate of 100 mL / min to obtain an ester bond-containing polycarboxylic acid (11) with a solid content of 40%. The molecular weight of the resulting ester group-containing polycarboxylic acid (number) was measured by aqueous GPC. The Ca trapping ability, biodegradability (based on OECD301F), and change in molecular weight after alkali decomposition were also measured. The results are shown in Table 3.

[0154] <Example 12> (Esterification process) 30.0 parts of ethylene glycol, 94.8 parts of maleic anhydride, and 20.0 parts of citric acid were charged into a 1 L SUS316L reaction vessel equipped with a stirrer and a reflux condenser, and the mixture was heated to 120°C with stirring, and then heated and stirred at 120°C for 60 minutes. (Polymerization process) After the esterification step, 2.0 parts of a 1.8% aqueous solution of Mohr's salt was added, and while stirring under reflux at the boiling point (about 110-135°C), 25.0 parts of diethanolamine, 90 parts of a 35% aqueous solution of hydrogen peroxide, and 35 parts of an 80% aqueous solution of acrylic acid were continuously dropped at a constant speed from separate feed lines over a period of 120 minutes. Then, under reflux at the boiling point, maturation was performed for 30 minutes. After maturation, the temperature was lowered, and 300 parts of pure water were added to obtain an ester bond-containing polycarboxylic acid (12) with a solid content of 45%. Physical properties were measured in the same manner as in Example 1, and the results are shown in Table 3.

[0155] [Table 3]

[0156] The results in Tables 1 and 2 reveal that the ester bond-containing polycarboxylic acid of the present disclosure has a good alkaline decomposition rate and biodegradability.

[0157] The results in Table 3 reveal that the ester bond-containing polycarboxylic acid of the present disclosure has good alkali decomposition rate and good carbon black dispersibility.

Claims

1. The main chain has a structural unit derived from an ester group, It has a carboxylic acid (salt) in the side chain. having a carboxylic acid (salt) at the β-position or γ-position of the carbonyl carbon of the ester group, The acid value is 100 mg (KOH) / kg or more, and has any one of the structures represented by the following general formulas (4) to (6). Ester bond-containing polycarboxylic acid (salt). 【Chemistry 1】 In formula (4), R 2 may be the same or different and represent a substituent having 2 to 10 carbon atoms and having two bonds. R 3 may be the same or different and is selected from a methylene group and a -CHCH 3 - group. R 4 represents a hydrogen atom, an alkali metal atom, an ammonium group, or an organic group, and at least one of the two R 4 s is a hydrogen atom, an alkali metal atom, or an ammonium group. In addition, x represents a positive integer of 1 or more. 【Chemistry 2】 In the general formula (5), R 2 represents a substituent having 2 to 10 carbon atoms and two bonds. R 4 is the same as in the general formula (4), and at least one of the five R 4 s is a hydrogen atom, an alkali metal atom, or an ammonium group. R 5 is a methylene group. y represents a positive integer of 1 or more. 【Chemistry 3】 In the general formula (6), R 2 represents a substituent having 2 to 10 carbon atoms and two bonds. R 4 is the same as in the general formula (4), and at least one of the two R 4 s is a hydrogen atom, an alkali metal atom, or an ammonium group. R 6 is a methylene group. z represents a positive integer of 1 or more.

2. The ester bond-containing polycarboxylic acid (salt) according to claim 1, which has an alkaline decomposition conversion rate of 10% or more as measured by the method described below. <Alkaline decomposition rate> The pH of the ester group-containing polymer (ester bond-containing polycarboxylic acid (salt)) was adjusted to 13 or more, and 48% NaOH was added and heated at 90° C. for 5 hours to carry out alkaline decomposition. The weight average molecular weight before and after the alkaline decomposition was measured under the following weight average molecular weight conditions, and the rate of change was taken as the rate of change from alkaline decomposition. Alkaline decomposition change rate (%)=(weight average molecular weight before alkaline decomposition−weight average molecular weight after alkaline decomposition) / (weight average molecular weight before alkaline decomposition)×100

3. An ester bond-containing polycarboxylic acid (salt) according to claim 1 or claim 2, which has a biodegradability of 20% or more according to the OECD 301F biodegradability test.

4. A detergent composition comprising the ester bond-containing polycarboxylic acid (salt) according to claim 1 or 2.

5. A step of reacting a compound having an unsaturated double bond and an acid anhydride group with a compound having two or more hydroxyl groups; reacting the double bond of the product of the above step. A method for producing an ester bond-containing polycarboxylic acid (salt).

6. The method includes a step of reacting a compound having three or more carboxylic acids (salts) or an anhydride thereof with a compound having two or more hydroxyl groups, The compound having three or more carboxylic acids (salts) or anhydrides thereof is an oligomer of one or more compounds selected from compounds having an unsaturated double bond and a carboxylic acid (salt) group.

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