JP5586144B2 - Polyalkylene glycol copolymer, process for producing the same, and detergent composition comprising the same - Google Patents

Description

The present invention relates to a polyalkylene glycol copolymer, a production method thereof, and an application thereof.

Conventionally, detergents used in apparel have been blended with detergent builders (detergent aids) such as zeolite, carboxymethyl cellulose, and polyethylene glycol for the purpose of improving the cleaning effect of the detergent.
In addition to the above various detergent builders, in recent years, polymers have been blended into detergent compositions as detergent builders.

  For example, a single chain derived from a polyalkylene glycol-based monomer having a hydrophobic moiety derived from glycidyl ether in the chain and / or at the end and having a polymerizable double bond derived from isoprenol, allyl alcohol, or methallyl alcohol. It is disclosed that a polyalkylene glycol-based polymer having a monomer unit and having a carboxylic acid group and / or a sulfonic acid group is used as a detergent builder (see Patent Document 1). Patent Document 1 discloses that the polymer has a performance of suppressing the precipitation of a surfactant and / or a performance of suppressing recontamination due to dirt during washing (referred to as a recontamination preventing ability).

  The performance required of detergent builders includes not only the ability to improve the cleaning power of detergents, but also the ability to suppress / prevent the precipitation of surfactants that lead to a reduction in cleaning power (hereinafter simply referred to as “deposition control ability”). Is also required. Here, the problem of precipitation of the surfactant is that the anionic surfactant, linear alkylbenzene sulfonic acid (salt) such as dodecylbenzene sulfonic acid (salt) (LAS) is present in calcium ions and magnesium. Since it is generated by bonding with ions, it is remarkable when cleaning is performed using water having relatively high hardness (see Non-Patent Document 1).

  Patent document 2 is mentioned as a technique which improves precipitation inhibitory ability. In Patent Document 2, a graft polymer obtained by graft polymerization of a predetermined amount of an acid group-containing unsaturated monomer to a polyoxyalkylene compound containing a hydrocarbon group exhibits excellent performance as a detergent builder. It has been shown that it can.

International Publication No. 2007/037469 Pamphlet JP 2007-254679 A Louis Ho Tan Tai, “Formulating Detergents and Personal Care Products”, AOCS Press, pp. 53-54 (2000)

As described above, despite the fact that various polymers have been reported in the past, there is actually no polymer that exhibits sufficient ability to suppress precipitation when used in detergent applications.
Therefore, the present invention has been made in view of the above circumstances, and provides a polymer (or polymer composition) that can effectively suppress the precipitation of a surfactant when used in detergent applications. For the purpose.
Another object of the present invention is to provide a method capable of efficiently producing such a polymer (or polymer composition).

As a result of intensive studies on various polymers (including copolymers) in order to achieve the above object, the present inventors have found that the structural unit is derived from a polyalkylene glycol monomer having a specific hydrophobic group. And a copolymer (polyalkylene glycol-based copolymer) in which a structural unit of a carboxyl group-containing monomer is introduced at a specific ratio has an excellent ability to suppress precipitation (performance to suppress / prevent precipitation of a surfactant). I knew that I had it. Based on the above findings, the present invention has been completed.
That is, the present invention is a structural unit (a) derived from a polyalkylene glycol monomer (A) represented by the following formula (1) of 1% by mass or more and less than 90% by mass,

In the general formula (1), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and Z represents an oxyalkylene structure having 2 to 30 carbon atoms. N represents a number of more than 5 and 300 or less, R ₁ represents an organic group having 8 to 20 carbon atoms,
10% by mass or more and less than 99% by mass of the structural unit (b) derived from the carboxyl group-containing monomer (B),
A polyalkylene glycol copolymer having as an essential structural unit.

The polyalkylene glycol copolymer of the present invention (or the polymer composition of the present invention) exhibits an excellent ability to suppress precipitation (performance to suppress / prevent precipitation of a surfactant). When a glycol-type copolymer is used for a detergent composition, precipitation of surfactant is effectively suppressed.

Hereinafter, the present invention will be described in detail.

[Polyalkylene glycol copolymer of the present invention]
<Polyalkylene glycol monomer as monomer (A)>
The polyalkylene glycol monomer of the present invention is required to have a specific proportion of the structural unit (a) derived from the polyalkylene glycol monomer (A) represented by the following general formula (1). .

In the general formula (1), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and Z represents an oxyalkylene structure having 2 to 30 carbon atoms. N represents a number exceeding 5 and not more than 300, and R ₁ represents an organic group having 8 to 20 carbon atoms.
In the general formula (1), n is preferably greater than 5 because the compatibility of the polyalkylene glycol copolymer obtained with the surfactant is improved. If the compatibility with the surfactant is improved, it is preferable because it can be added to a liquid drug such as a liquid detergent. Further, n is preferably 110 or less, and more preferably 55 or less, since the ability of the surfactant to suppress precipitation is further improved.

In the general formula (1), R is preferably a CH ₂ CH ₂ group or a CH ₂ group because the effect of improving the precipitation suppressing ability of the resulting copolymer is high.
In the present specification, the case where R represents a single bond means that, for example, when it is represented as C—R—O, it becomes C—C.

In the general formula (1), as described above, R ₁ is an organic group having 8 to 20 carbon atoms, but R ₁ is preferably an organic group having 8 to 17 carbon atoms, and has 8 to 8 carbon atoms. More preferably, it is 14 organic groups. R ₁ may contain a functional group such as an amino group, an amide group, a hydroxyl group, an alkoxide group, a sulfonic acid group, a carbonyl group, or a carboxyl group. R ₁ may contain an ether bond, a sulfide bond, an ester bond, or an amide bond. The organic group is preferably an alkyl group, an aryl group, or an alkenyl group, since the effect of improving the ability to suppress precipitation of the resulting copolymer is high.

Preferable R ₁ is specifically an octyl group, a lauryl group, a stearyl group, a cyclohexyl group, an alkyl group such as a 2-ethylhexyl group; an alkenyl group such as an octylene group or a nonylene group; an aryl group such as a naphthyl group or a nonylphenyl group. Can be mentioned.

As the monomer of the general formula (1), a monomer in which R ₁ is an alkyl group having 8 to 20 carbon atoms, and R ₁ is an organic group represented by the following general formulas (4) to (6). Preferably, it is a monomer.
(I) The monomer in which R ₁ is an alkyl group having 8 to 20 carbon atoms is preferably (i-1) reacting methallyl chloride, allyl chloride or isoprenyl chloride with the corresponding monoalkoxypolyalkylene glycol. Preferably, it is produced by the method, (i-2) a method of reacting an alkylene oxide adduct of methallyl alcohol or allyl alcohol or isoprenol with a corresponding alkyl halide.
(Ii) A monomer in which R ₁ is represented by an organic group represented by the following general formula (4) is a halogenated compound such as methallyl alcohol, allyl alcohol, or isoprenol, and an alkylene oxide adduct such as epichlorohydrin. It is preferable to produce by reacting a compound to which a glycidyl compound is added with a compound having an amino group, a hydroxyl group or a thiol group, or a compound to which an alkylene oxide is added.
(Iii) The monomer represented by R ₁ represented by the following general formula (5) is an ester compound or acid corresponding to an alkylene oxide adduct of methallyl alcohol, allyl alcohol, or isoprenol. It is preferable to manufacture by the method of making it react.
(IV) A monomer represented by the monomer represented by the following general formula (6) in which R ₁ is reacted with an isocyanate compound corresponding to an alkylene oxide adduct of methallyl alcohol, allyl alcohol, or isoprenol. It is preferable to manufacture by a method.

X and Y in the general formula (4) represent a hydroxyl group or an organic group represented by the following general formula (4-2), one of X and Y is a hydroxyl group, and the other is the general formula (4 -2) to (4-4), and R ₄ in the general formulas (5) and (6) represents an alkyl group having 8 to 19 carbon atoms. Here, the said general formula (4)-(6) couple | bonds with the remaining part of the said general formula (1) through the carbon atom of the left end in a formula.

In General Formulas (4-2) to (4-4), Z represents an alkylene glycol group having 2 to 9 carbon atoms, n is 0 to 4, and General Formulas (4-2) to (4-3) R ₄ represents an alkyl group having 8 to 17 carbon atoms, and in the general formula (4-4), R ₅ and R ₆ represent a hydrogen atom or an alkyl group having 1 to 17 carbon atoms. Here, the general formula (4-2) is bonded to the remaining part of the general formula (4) through the oxygen atom at the left end in the formula, and the general formulas (4-3) to (4-4) are The oxygen atom in Z at the left end in the formula is bonded to the rest of the general formula (4).

  As a method for producing the monomer of the general formula (1), among the above (i) to (iV), since the yield of the monomer is high (the generation of impurities is small), the above (i), (iii) ) And (iV). Particularly preferred is (i) above.

As described above, in the general formula (1), Z represents an oxyalkylene structure having 2 to 30 carbon atoms. Examples of oxyalkylene include oxyethylene, oxypropylene, and oxybutylene. It may contain an oxyphenylene or oxynaphthylene group.
From the viewpoint of easy production of the polymer, 50 mol% or more of the oxyalkylene structure in the general formula (1) is preferably an oxyethylene structure. More preferably, in the oxyalkylene structure, 80 mol% or more is an oxyethylene structure, and most preferably 100 mol% is an oxyethylene structure. Specifically, 100 mol% of the oxyalkylene structure is an oxyethylene structure. Specifically, for example, when the monomer (A) is a monomer represented by the general formula (1), the monomer (A) has a structure represented by the following general formula (11).

In the general formula (11), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group, a CH ₂ CH ₂ group or a single bond, and Z represents an oxyalkylene structure having 2 to 30 carbon atoms. N represents a number exceeding 5 and not more than 300, and R ₁ represents an organic group having 8 to 20 carbon atoms.

  Since the polyalkylene glycol copolymer of the present invention of the present invention stably exhibits precipitation inhibiting ability even under alkaline conditions, the monomer (A) may not contain an ester group or an amide group. preferable.

The structural unit (a) is a monomer (A), that is, in the above formula (1), the unsaturated double bond (CH ₂ ═CH—) is a single bond (—CH ₂ —CH—). It becomes.
That is, the structural unit (a) derived from the monomer (A) indicates a structure represented by the following general formula.

In the general formula (P-1), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group, a CH ₂ CH ₂ group, or a single bond, and Z represents an oxy of 2 to 30 carbon atoms. Represents an alkylene structure, n represents a number of more than 5 and 300 or less, and R ₁ represents an organic group having 8 to 20 carbon atoms.

  By introducing the structural unit (a) into the polyalkylene glycol copolymer of the present invention, the polyalkylene glycol copolymer increases the interaction with the surfactant and precipitates the surfactant. Can be suppressed. In addition, since the monomer (A) is relatively easy to copolymerize with the monomers (B) and (C) even in a hydrophilic solvent such as water, the resulting polyalkylene glycol copolymer is obtained. The ability to suppress the precipitation of coalesces can be significantly improved.

  In the polyalkylene glycol copolymer of the present invention, the structural unit (a) derived from the polyalkylene glycol monomer (A) represented by the general formula (1) is 100% by mass derived from all monomers. On the other hand, it is essential to have at least 1% by mass and less than 90% by mass. In the present invention, a monomer refers to a compound having an unsaturated double bond (referring to a carbon-carbon double bond). If the structural unit (a) is within the above range, an excellent effect of improving the ability of the copolymer to precipitate can be obtained. The ratio of the structural unit (a) to 100% by mass of the structure derived from all monomers is preferably 2% by mass or more and less than 70% by mass, more preferably 3% by mass or more and less than 60% by mass, more preferably It is 4 mass% or more and less than 50 mass%, Most preferably, it is 5 mass% or more and less than 40 mass%. When the polyalkylene glycol copolymer of the present invention has the structural unit (a) derived from the monomer (A) within the above range, the copolymer exhibits good water solubility, and the residual polyalkylene glycol system. Monomers tend to decrease. Due to the reduction of the residual polyalkylene glycol monomer, the uniformity when the polyalkylene glycol copolymer of the present invention is stored in an aqueous solution is improved.

<Carboxyl group-containing monomer>
The polyalkylene glycol copolymer of the present invention is required to have the structural unit (b) derived from the carboxyl group-containing monomer (B) at a specific ratio.

  The carboxyl group-containing monomer (B) of the present invention is a monomer that essentially contains 1) an unsaturated double bond and 2) a carboxyl group and / or a salt thereof (provided that the monomer (A) or Monomers belonging to the monomer (C) are excluded from the monomer (B)). Specifically, unsaturated monocarboxylic acids and salts thereof such as acrylic acid, methacrylic acid, crotonic acid, α-hydroxyacrylic acid, α-hydroxymethylacrylic acid and derivatives thereof; itaconic acid, fumaric acid, Examples thereof include unsaturated dicarboxylic acids such as maleic acid and 2-methylene glutaric acid, and salts thereof. In this case, the unsaturated dicarboxylic acid monomer may be any monomer having one unsaturated group and two carboxyl groups in the molecule, such as maleic acid, itaconic acid, citraconic acid, and fumaric acid. In addition, a monovalent metal salt, a divalent metal salt, an ammonium salt, an organic ammonium salt (organic amine salt), or the like thereof, or an anhydride thereof is preferable. Alternatively, the (meth) acrylic acid monomer (A) is a half ester of an unsaturated dicarboxylic acid monomer and an alcohol having 1 to 22 carbon atoms, an unsaturated dicarboxylic acid and an amine having 1 to 22 carbon atoms. And a half amide of an unsaturated dicarboxylic acid monomer and a glycol having 2 to 4 carbon atoms, a half amide of maleamic acid and a glycol having 2 to 4 carbon atoms, and the like.

  The salt of the unsaturated monocarboxylic acid or the salt of the unsaturated dicarboxylic acid is a metal salt, an ammonium salt or an organic amine salt. In this case, the metal salt is a monovalent metal salt of an alkali metal such as sodium salt, lithium salt, potassium salt, rubidium salt or cesium salt; alkaline earth such as magnesium salt, calcium salt, strontium salt or barium salt Metal salts; salts of aluminum, iron, etc. Organic amine salts include monoethanolamine salts, diethanolamine salts, triethanolamine salts and other alkanolamine salts; monoethylamine salts, diethylamine salts, triethylamine salts and other alkylamine salts; ethylenediamine salts, triethylenediamine salts and other polyamines And salts of organic amines such as Of these, ammonium salt, sodium salt, and potassium salt are preferred, and sodium salt is more preferred because of the high effect of improving the ability of the obtained copolymer to suppress precipitation.

  Among the carboxyl group-containing monomers (B), acrylic acid, acrylate, maleic acid and maleate are preferable because they have a high effect of improving the ability to suppress precipitation of the copolymer, and acrylic acid and acrylate Is more preferable.

  The carboxyl group-containing monomer (B) may be only one type, but may have a structure derived from two or more types. In this case, the polyalkylene glycol copolymer of the present invention has a total ratio of the structural units (b) derived from all kinds of carboxyl group-containing monomers (B) at a specific ratio.

The structural unit (b) is in a form in which the unsaturated double bond (CH ₂ ═CH—) of the monomer (B) is a single bond (—CH ₂ —CH—).

  In the polyalkylene glycol copolymer of the present invention, the structural unit (b) derived from the carboxyl group-containing monomer (B) is 10% by mass to 99% by mass with respect to 100% by mass of the structure derived from all monomers. It is essential to have a ratio of less than. When the structural unit (b) is within the above range, an excellent effect of improving the ability of the copolymer to precipitate can be obtained. The proportion of the structural unit (b) with respect to 100% by mass of the structure derived from all monomers is preferably 30% by mass or more and less than 98% by mass, more preferably 40% by mass or more and less than 97% by mass, more preferably It is 50 mass% or more and less than 96 mass%, Most preferably, it is 60 mass% or more and less than 95 mass%.

  When the polyalkylene glycol copolymer of the present invention is used as a detergent builder, it has the structural unit (a) and can exhibit an effect of suppressing the precipitation of the interacting surfactant.

  Since the polyalkylene glycol copolymer of the present invention has the structural unit (b) at a specific ratio, the copolymer tends to exhibit good water solubility, and the residual polyalkylene glycol monomer tends to be reduced. is there. Due to the reduction of the residual polyalkylene glycol monomer, the uniformity when the polyalkylene glycol copolymer of the present invention is stored in an aqueous solution is improved.

In addition, in this invention, when calculating the mass ratio (mass%) with respect to the structure derived from all the monomers of the structural unit (b) derived from a carboxyl group-containing monomer (B), it calculates as a corresponding acid conversion. Shall. For example, if the structural unit is —CH ₂ —CH (COONa) — derived from sodium acrylate, the structural unit —CH ₂ —CH (COOH) — derived from acrylic acid, which is the corresponding acid, is represented by a mass ratio (mass% ). Similarly, also when calculating the mass ratio (mass%) with respect to all the monomers of a carboxyl group-containing monomer (B), it shall calculate as a corresponding acid conversion. For example, if it is sodium acrylate, a mass ratio (mass%) is calculated as acrylic acid which is a corresponding acid.

  Furthermore, when calculating the mass ratio (% by mass) of the structural unit derived from the acid group-containing monomer other than the carboxyl group-containing monomer (B) with respect to the structure derived from all monomers, the calculation is performed as the corresponding acid conversion. In the case of calculating the mass ratio (% by mass) of the acid group-containing monomer other than the carboxyl group-containing monomer (B) with respect to all the monomers, it is also calculated as the corresponding acid conversion. The structural unit derived from the amino group-containing monomer and the amino group-containing monomer are also mass-calculated as the corresponding structural unit derived from the unneutralized amine and the unneutralized amine. For example, in the case of vinylamine hydrochloride, the mass ratio (% by mass) is calculated as vinylamine which is the corresponding unneutralized amine.

<Other monomers>
The polyalkylene glycol copolymer of the present invention may have a structural unit (c) derived from other monomer (C).
As the other monomer (C) when the polyalkylene glycol copolymer of the present invention contains another monomer (C), copolymerization with the monomer (A) and / or (B) described above is carried out. It is not particularly limited as long as it is possible, and is appropriately selected depending on a desired effect. Specifically, vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, acrylamido-2-methylpropane sulfonic acid, sodium 2-hydroxy-3-allyloxypropane sulfonate, 2-hydroxy-3- Sodium methallyloxypropane sulfonate, isoprene sulfonic acid, sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2-hydroxy-3butenesulfonic acid, etc. N-vinyl monomers such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide, N-vinyl-N-methylacetamide, N-vinyloxazolidone; ) Amide monomers such as acrylamide, N, N-dimethylacrylamide and N-isopropylacrylamide; alkyl (meth) acrylates such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and dodecyl (meth) acrylate Ester monomers; 3- (meth) allyloxy-1,2-dihydroxypropane, 3-allyloxy-1,2-dihydroxypropane, 3-allyloxy-1,2-dihydroxypropane, (meth) allyl alcohol, isoprenol, etc. Compound (3-allyloxy-1,2-di (poly) oxyethylene ether propane etc.) obtained by adding 6 to 200 mol of ethylene oxide to a hydroxyl group-containing unsaturated monomer, polyalkylene glycol ester of (meth) acrylic acid Etc .; hydroxyethyl ( Acrylate), 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxy (Meth) acrylic acid hydroxyalkyl monomers such as butyl (meth) acrylate, α-hydroxymethylethyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyneopentyl (meth) acrylate, and hydroxyhexyl (meth) acrylate , Vinyl aryl monomers such as styrene, indene and vinylaniline, isobutylene, vinyl acetate and the like.
Moreover, the said other monomer (C) may be used individually by 1 type, or may be used with the form of a 2 or more types of mixture.
In the polyalkylene glycol-based copolymer of the present invention, the structural units (a) and (b), and if necessary, the structural unit (c) may be introduced at a specific ratio as described above. Each structural unit may exist in either a block shape or a random shape. Moreover, the weight average molecular weight of the polyalkylene glycol copolymer of the present invention can be appropriately set, and is not particularly limited. Specifically, the weight average molecular weight of the polyalkylene glycol copolymer is preferably 1,000 to 200,000, more preferably 1,500 to 60,000, and most preferably 2,000 to 30. , 000. When the weight average molecular weight is within the above range, the precipitation suppressing ability tends to be improved. In addition, in this specification, a weight average molecular weight is a measured value by GPC (gel permeation chromatography), and the specific measuring method is computed according to the method described in an Example.
Since the polyalkylene glycol copolymer of the present invention is excellent in precipitation suppressing ability and suppresses precipitation of surfactant, it is used, for example, in a detergent composition.

  By the way, in the above-mentioned Patent Document 1, as a terminal-modified polyalkylene glycol-based monomer, (i) a single monomer in which a polymerizable double bond is introduced by reacting a polyalkylene glycol having a terminal hydrophobic group with allyl glycidyl ether or the like. And (ii) a monomer having a hydrophobic group introduced by reacting an epoxy compound having a hydrophobic group with a terminal hydroxyl group of an alkylene oxide adduct of an unsaturated alcohol.

  However, when a monomer is produced using an epoxy compound such as allyl glycidyl ether or an epoxy compound having a hydrophobic group, for example, in the former case, the hydroxyl group produced when allyl glycidyl ether reacts with alcohol, A side reaction that reacts with allyl glycidyl ether may produce a monomer having two or more allyl groups. Due to this, there is room for improvement from the viewpoint that the solution viscosity may increase during copolymerization. In addition, if a monomer having two or more allyl groups is generated by the side reaction, an alcohol having no allyl group (polymerizable group) is generated because the allyl glycidyl ether is insufficient in terms of stoichiometry. Will be. Due to this, there remains room for improvement from the viewpoint that it may remain as an impurity even after copolymerization and the performance of the copolymer (such as the ability to suppress precipitation) may be reduced. Similarly, in the latter case, a hydroxyl group generated when an epoxy compound having a hydrophobic group reacts with an alkylene oxide adduct of an unsaturated alcohol further reacts with an epoxy compound having a hydrophobic group, resulting in a hydrophobic group. May form a monomer having two. Due to this, there is room for improvement from the viewpoint that polymerization may become difficult and remain as impurities. In addition, if a monomer reacts with two or more epoxy compounds having a hydrophobic group by the side reaction, the epoxy compound having a hydrophobic group is stoichiometrically insufficient. Unsaturated alcohol or the like that will not be produced. Due to this, there was room for improvement from the viewpoint that the performance of the copolymer (such as the ability to suppress precipitation) may be reduced.

  On the other hand, since the polyalkylene glycol monomer represented by the general formula (1) can be produced with high purity, the above problems can be suppressed and a preferable polyalkylene glycol copolymer can be produced.

[Polyalkylene glycol copolymer composition of the present invention (also simply referred to as polymer composition)]
The polyalkylene glycol-based copolymer composition of the present invention contains the polyalkylene glycol-based copolymer of the present invention as an essential component, and components other than the polyalkylene glycol-based copolymer are optional. 1 or more chosen from a polymerization initiator residue, a residual monomer, the by-product at the time of superposition | polymerization, and a water | moisture content. A preferable form of the polyalkylene glycol copolymer composition is a form containing 30 to 80% by mass of the polyalkylene glycol copolymer and 20 to 70% by mass of water.

[Method for Producing Polyalkylene Glycol Copolymer of the Present Invention]
As a method for producing the polyalkylene glycol copolymer of the present invention, a known polymerization method may be used in the same manner or modified unless otherwise specified. As a method for producing the polyalkylene glycol copolymer of the present invention, a monomer component containing a polyalkylene glycol monomer (A) and a carboxyl group-containing monomer (B) as essential components is copolymerized. Can be manufactured. Moreover, when copolymerizing a monomer component, you may further copolymerize the said other monomer (C) as needed.

  In such a production method, the monomer component may be copolymerized using a polymerization initiator. In addition, the kind and usage-amount of the monomer contained in a monomer component are set suitably so that the structural unit which comprises a polyalkylene glycol type copolymer may become as mentioned above. That is, the composition ratio of each monomer forming the polyalkylene glycol copolymer is such that the polyalkylene glycol comonomer (A) is 1% by mass or more and less than 90% by mass with respect to all monomers. The carboxyl group-containing monomer (B) is 10% by mass or more and less than 99% by mass. As described above, when the total amount of the monomers (A) to (B) is 100% by mass, the other monomer (C) copolymerizable with these can be further added in an amount of 0 to 10% by mass. May be used in quantities. More preferably, the polyalkylene glycol monomer (A) is 2% by mass or more and less than 70% by mass, the carboxyl group-containing monomer (B) is 30% by mass or more and less than 98% by mass, and more preferably, The alkylene glycol monomer (A) is 3% by weight or more and less than 60% by weight, and the carboxyl group-containing monomer (B) is 40% by weight or more and less than 97% by weight, more preferably a polyalkylene glycol monomer. The body (A) is 4% by weight or more and less than 50% by weight, the carboxyl group-containing monomer (B) is 50% by weight or more and less than 96% by weight, and most preferably, the polyalkylene glycol monomer (A) is 5 mass% or more and less than 40 mass%, and a carboxyl group-containing monomer (B) is 60 mass% or more and less than 95 mass%. The total amount of the monomers (A), (B) and (C) is 100% by mass.

  In the present invention, the copolymerization of the monomers (A) to (B) and, if necessary, other monomers (C) uses water in 50% by mass or more of the solvent used and / or a chain. It is preferably carried out in the presence of a transfer agent, more preferably 50% by mass or more of the solvent used and water in the presence of a chain transfer agent. At this time, by using water in 50% by mass or more of the solvent to be used, the amount of the organic solvent used for the polymerization can be suppressed, so that there is an advantage that the organic solvent can be easily distilled off after the completion of the polymerization. In addition, when a chain transfer agent is used, the polyalkylene glycol copolymer to be produced can be prevented from becoming unnecessarily high in molecular weight, and a low molecular weight polyalkylene glycol copolymer can be produced efficiently. There is an advantage. In particular, when sulfurous acid or sulfite is used as a chain transfer agent, a sulfonic acid group can be quantitatively introduced into the terminal of the resulting polyalkylene glycol-based copolymer as described in detail below. Can be improved.

  Therefore, a preferable embodiment of the production method of the present invention is 1% by mass or more and less than 90% by mass of the polyalkylene glycol monomer (A) of the formula (1), 10% by mass or more and less than 99% by mass of the formula (2). Carboxyl group-containing monomer (B), other monomer (C) if necessary (however, the total ratio of monomers (A), (B) and (C) is 100% by mass) The present invention relates to a method for producing a polyalkylene glycol copolymer, which comprises a step of carrying out a polymerization reaction using water in 50% by mass or more of a solvent used and a chain transfer agent.

  The solvent used in the above embodiment is not particularly limited as long as it contains water in a proportion of 50% by mass with respect to the total amount of the solvent used. From the viewpoint of improving the solubility of the monomer used for polymerization in a solvent, an organic solvent may be added as necessary. Even in this case, the content of water in the total mixed solvent is 50% by mass or more. Examples of the organic solvent that can be used include lower alcohols such as methanol, ethanol, and isopropyl alcohol; lower ketones such as acetone, methyl ethyl ketone, and diethyl ketone; ethers such as dimethyl ether and dioxane; amides such as dimethylformaldehyde. . These solvents may be used alone or in the form of a mixture of two or more. In the present invention, the amount of water is preferably 80% by mass or more, and most preferably water alone (ie, 100% by mass) with respect to the total amount of solvent used.

  In the production method of the present invention, the copolymerization is preferably performed in the presence of a chain transfer agent. The chain transfer agent that can be used in this case is not particularly limited as long as it is a compound capable of adjusting the molecular weight, and a known chain transfer agent can be used. Specifically, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropion, 3-mercaptopropion, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, n -Thiol chain transfer agents such as dodecyl mercaptan, octyl mercaptan, butylthioglycolate; Halides such as carbon tetrachloride, methylene chloride, bromoform, bromotrichloroethane; Secondary alcohols such as isopropanol, glycerin; Acids, hypophosphorous acid, and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionite, metabisulfite, and salts thereof (sodium hydrogen sulfite, hydrogen bisulfite) Potassium, sodium dithionite Um, potassium dithionite, sodium metabisulfite, metabisulfite potassium, etc.) and the like, and the like lower oxides and salts thereof. The chain transfer agent may be used alone or in the form of a mixture of two or more. Among these, in the copolymerization reaction according to the present invention, it is preferable to use sulfite or sulfite. Thereby, a sulfonic acid group can be quantitatively introduced into the main chain terminal of the obtained polyalkylene glycol copolymer, and the gel resistance can be improved. In addition, the fact that the sulfonic acid group can be introduced quantitatively indicates that the sulfite is functioning very well as a chain transfer agent and the like. Thus, it is possible to reduce the increase in the production cost of the copolymer, improve the production efficiency, and sufficiently reduce the impurities. Further, by adding sulfite to the polymerization reaction system, it is possible to suppress the resulting copolymer from having a higher molecular weight than necessary.

  In the above production method, as described above, sulfurous acid and / or sulfite (hereinafter simply referred to as “sulfurous acid (salt)”) is preferably included as a chain transfer agent. Moreover, in the said manufacturing method, in addition to a sulfurous acid (salt), an initiator is used. Furthermore, heavy metal ions may be used in combination as a reaction accelerator.

The sulfurous acid (salt) refers to sulfurous acid or hydrogen sulfite or a salt thereof, and a form in which sulfurous acid / bisulfite is a salt is preferable. When sulfite / bisulfite is a salt, in addition to the examples described above, salts of metal atoms, ammonium or organic ammonium are preferred. Examples of the metal atom include monovalent metal atoms of alkali metals such as lithium, sodium and potassium; divalent metal atoms of alkaline earth metals such as calcium and magnesium; trivalent metal atoms such as aluminum and iron And the like are preferred. As the organic ammonium (organic amine), alkanolamines such as ethanolamine, diethanolamine, and triethanolamine, and triethylamine are preferable. Further, it may be ammonium. Therefore, examples of the sulfite preferably used in the present invention include sodium bisulfite, potassium bisulfite, ammonium bisulfite, sodium sulfite, potassium sulfite, ammonium sulfite and the like, and sodium bisulfite is particularly suitable. The above sulfurous acid (salt) may be used alone or in the form of a mixture of two or more.

  In the method of the present invention, the addition amount of the chain transfer agent is not limited as long as the monomer (A), (B) and, if necessary, the other monomer (C) is polymerized satisfactorily, Preferably, it is 1 to 20 g, more preferably 2 to 15 g, based on 1 mol of all monomer components consisting of monomers (A) and (B) and, if necessary, other monomer (C). . If the molecular weight is less than 1 g, the molecular weight may not be controlled. On the other hand, if it exceeds 20 g, a large amount of impurities may be generated and the pure polymer content may be reduced. Especially when sulfite is used. Excess sulfite may be decomposed in the reaction system, and sulfurous acid gas may be generated. Moreover, there is a risk that it may be economically disadvantageous.

  As the initiator, known ones can be used, for example, hydrogen peroxide; persulfates such as sodium persulfate, potassium persulfate, ammonium persulfate; 2,2′-azobis (2-amidinopropane) Azo compounds such as hydrochloride, 4,4′-azobis-4-cyanoparerenic acid, azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide Organic peroxides such as lauroyl peroxide, peracetic acid, di-t-butyl peroxide and cumene hydroperoxide are preferred. Of these polymerization initiators, hydrogen peroxide and persulfate are preferable, and persulfate is most preferable. These polymerization initiators may be used alone or in the form of a mixture of two or more.

  The amount of the initiator used is not particularly limited as long as it is an amount capable of initiating copolymerization of the monomers (A) and (B) and, if necessary, other monomers (C). ), (B) and if necessary, it is preferably 10 g or less, more preferably 1 to 5 g, based on 1 mol of all monomer components comprising the other monomer (C).

The heavy metal ion used as a reaction accelerator in the present invention means a metal having a specific gravity of 4 g / cm ³ or more. As said metal ion, iron, cobalt, manganese, chromium, molybdenum, tungsten, copper, silver, gold, lead, platinum, iridium, osmium, palladium, rhodium, ruthenium etc. are preferable, for example. These heavy metals can be used alone or in combination of two or more. Among these, iron is more preferable. The ionic valence of the heavy metal ions is not particularly limited. For example, when iron is used as the heavy metal, the iron ions in the initiator may be Fe ²⁺ or Fe ³⁺ , and these may be combined. May be.

The heavy metal ions are not particularly limited as long as they are included in the form of ions. However, it is preferable to use a method using a solution in which a heavy metal compound is dissolved because the handleability is excellent. The heavy metal compound used in that case should just contain the heavy metal ion desired to contain in an initiator, and can be determined according to the initiator to be used. When iron is used as the heavy metal ion, the mole salt (Fe (NH ₄ ) ₂ (SO ₄ ) ₂ · 6H ₂ O), ferrous sulfate · 7 hydrate, ferrous chloride, ferric chloride, etc. It is preferable to use a heavy metal compound or the like. Moreover, when using manganese as a heavy metal ion, manganese chloride etc. can be used suitably. In the case of using these heavy metal compounds, since they are water-soluble compounds, they can be used in the form of an aqueous solution and have excellent handleability. The solvent of the solution obtained by dissolving the heavy metal compound is not limited to water, and does not hinder the polymerization reaction in the production of the polyalkylene glycol copolymer of the present invention, and is a heavy metal. Any compound that dissolves the compound may be used.

  In the polymerization step in the present invention, the amount of heavy metal ions in the case of using the above heavy metal ions, it is preferable that a catalyst amount is included. The amount of catalyst referred to in the present specification means that the catalyst acts as a catalyst rather than being incorporated into the final target product. Specifically, it is 100 ppm or less, preferably 10 ppm or less, more preferably 5 ppm. It is as follows.

  The content of the heavy metal ions is preferably 0.1 to 10 ppm with respect to the total mass of the polymerization reaction solution at the completion of the polymerization reaction. If the content of heavy metal ions is less than 0.1 ppm, the effect of heavy metal ions may not be sufficiently exhibited. On the other hand, if the content of heavy metal ions exceeds 10 ppm, the color tone of the resulting polymer may be deteriorated. Moreover, when there is much content of heavy metal ion, when using the polymer which is a product as a detergent builder, there exists a possibility of becoming a cause of coloring stain | pollution | contamination.

  The time when the polymerization reaction is completed means the time when the polymerization reaction is substantially completed in the polymerization reaction solution and a desired polymer is obtained. For example, when the polymer polymerized in the polymerization reaction solution is neutralized with an alkali component, the content of heavy metal ions is calculated based on the total mass of the polymerization reaction solution after neutralization. When two or more kinds of heavy metal ions are included, the total amount of heavy metal ions may be in the above range.

  As a combination of the initiator and the chain transfer agent, it is most preferable to use one or more persulfates and sulfites. In this case, the mixing ratio of persulfate and sulfite is not particularly limited, but it is preferable to use 0.5 to 5 parts by mass of sulfite with respect to 1 part by mass of persulfate. More preferably, with respect to 1 part by mass of persulfate, the lower limit of sulfite is 1 part by mass, and most preferably 2 parts by mass. Further, the upper limit of the sulfite is more preferably 4 parts by mass, and most preferably 3 parts by mass with respect to 1 part by mass of the persulfate. Here, if the amount of sulfite is less than 0.5 parts by mass, the total amount of the initiator may increase when the molecular weight is lowered. Conversely, if the amount exceeds 5 parts by mass, side reactions increase, resulting in impurities. May increase.

The combination of the chain transfer agent, the initiator, and the reaction accelerator is not particularly limited, and can be appropriately selected from the above examples. For example, a combination of a chain transfer agent, an initiator, and a reaction accelerator includes sodium bisulfite (SBS) / hydrogen peroxide (H ₂ O ₂ ), sodium bisulfite (SBS) / sodium persulfate (NaPS), and bisulfite. Sodium (SBS) / Fe, Sodium bisulfite (SBS) / Hydrogen peroxide (H ₂ O ₂ ) / Fe, Sodium bisulfite (SBS) / Sodium persulfate (NaPS) / Fe, Sodium bisulfite (SBS) / Over Forms such as sodium sulfate (NaPS) / hydrogen peroxide (H ₂ O ₂ ) and sodium bisulfite (SBS) / oxygen / Fe are preferred. More preferred are sodium bisulfite (SBS) / sodium persulfate (NaPS), sodium bisulfite (SBS) / sodium persulfate (NaPS) / Fe, and most preferred sodium bisulfite (SBS) / sodium persulfate ( NaPS) / Fe.

  The total amount of the chain transfer agent, initiator, and reaction accelerator used is 1 mol of all monomer components consisting of monomers (A) and (B) and, if necessary, other monomers (C). Is preferably 2 to 20 g. By setting it as such a range, the polyalkylene glycol-type copolymer of this invention can be produced efficiently, and the molecular weight distribution of a polyalkylene glycol-type copolymer can be made into a desired thing. More preferably, it is 4-18g, More preferably, it is 6-15g.

As a method for adding the polymerization initiator and the chain transfer agent to the reaction vessel, a continuous charging method such as dropping or divided charging can be applied. In addition, the chain transfer agent may be introduced into the reaction vessel alone, and is previously confused with each monomer (A) to (B), other monomer (C), solvent, etc. constituting the monomer component. You may keep it.

  In the above copolymerization method, monomer components, polymerization initiators, etc. can be added to the reaction vessel by charging all of the monomer components into the reaction vessel and adding the polymerization initiator into the reaction vessel. Method of performing polymerization: charging a part of the monomer component into the reaction vessel, and adding the polymerization initiator and the remaining monomer component continuously or stepwise (preferably continuously) into the reaction vessel. A method in which a polymerization solvent is charged into a reaction vessel and the whole amount of monomer components and a polymerization initiator is added; one of monomers (A) to (B) (for example, a single amount) A part of the body (B)) is charged into a reaction vessel, the polymerization initiator and the remaining monomer components (the remainder of the monomer (B) and the monomer (A), and if necessary, the monomer (C Copolymerization is carried out by adding (preferably continuously) all of Method and the like are suitable. Among such methods, the molecular weight distribution of the obtained copolymer can be narrowed (sharpened), and the dispersibility when used as a detergent builder can be improved. It is preferable to carry out copolymerization by a method in which body components are successively dropped into a reaction vessel.

  The copolymerization method can be carried out by commonly used methods such as solution polymerization, suspension polymerization, emulsion polymerization and the like, and is not particularly limited, but solution polymerization is preferred. As described above, the solvent that can be used in this case is preferably a mixed solvent in which 50% by mass of water or water is based on the total solvent. When only water is used, it is preferable in that the solvent removal step can be omitted.

  The copolymerization method can be carried out either batchwise or continuously. In addition, a known solvent can be used as needed during copolymerization, and water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; glycerin; polyethylene glycol; benzene, toluene, xylene Aromatic or aliphatic hydrocarbons such as cyclohexane and n-heptane; Esters such as ethyl acetate; Ketones such as acetone and methyl ethyl ketone; Amides such as dimethylformaldehyde; Ethers such as diethyl ether and dioxane It is. These may be used alone or in combination of two or more. Among these, from the viewpoint of the solubility of the monomer component and the resulting copolymer, one or more solvents selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms may be used. preferable.

  As the usage-amount of the said solvent, 40-200 mass% is preferable with respect to 100 mass% of monomer components. More preferably, it is 45 mass% or more, More preferably, it is 50 mass% or more. Moreover, More preferably, it is 180 mass% or less, More preferably, it is 150 mass% or less. If the amount of the solvent used is less than 40% by mass, the resulting copolymer may have a high molecular weight. If it exceeds 200% by mass, the concentration of the obtained copolymer will be low, and solvent removal is required. There is a risk. The solvent may be partly or wholly charged in the reaction vessel in the initial stage of polymerization, but a part of the solvent may be added (dropped) into the reaction system during the polymerization reaction, or the monomer. Components, initiators, and the like may be added (dropped) into the reaction system during the polymerization reaction together with these components in a form in which the components and initiator are dissolved in advance.

In the above copolymerization method, the copolymerization conditions such as the copolymerization temperature are appropriately determined depending on the copolymerization method used, the solvent, and the polymerization initiator, but the copolymerization temperature is usually preferably 0 ° C. or higher. Moreover, it is preferable that it is 150 degrees C or less. More preferably, it is 40 degreeC or more, More preferably, it is 60 degreeC or more, Most preferably, it is 80 degreeC or more. Moreover, More preferably, it is 120 degrees C or less, More preferably, it is 110 degrees C or less. In particular, when sulfurous acid (salt) is used, the copolymerization temperature is usually 60 ° C to 95 ° C, preferably 70 ° C to 95 ° C, and more preferably 80 ° C to 95 ° C. At this time, below 60 ° C,
There is a possibility that a large amount of impurities derived from sulfurous acid (salt) may be generated. On the contrary, when it exceeds 95 ° C., toxic sulfurous acid gas may be released.

  The copolymerization temperature need not always be kept substantially constant in the polymerization reaction. For example, the polymerization is started from room temperature, the temperature is increased to a set temperature at an appropriate temperature increase time or rate, and then the set temperature is reached. Depending on the dropping method of the monomer component, the initiator, etc., the temperature may be changed over time (temperature increase or decrease) during the polymerization reaction.

  The copolymerization time is preferably 30 to 360 minutes. More preferably, it is 60-300 minutes, More preferably, it is 120-240 minutes. In the present invention, “copolymerization time” represents the time during which a monomer is added unless otherwise specified.

  The pressure in the reaction system in the copolymerization method may be any of normal pressure (atmospheric pressure), reduced pressure, and increased pressure, but in terms of the molecular weight of the resulting copolymer, The reaction system is preferably sealed and the reaction is carried out under pressure. Moreover, it is preferable to carry out under a normal pressure (atmospheric pressure) at the point of equipment, such as a pressurization apparatus, a pressure reduction apparatus, a pressure-resistant reaction container, and piping. The atmosphere in the reaction system may be an air atmosphere, but is preferably an inert atmosphere. For example, the inside of the system is preferably replaced with an inert gas such as nitrogen before the start of polymerization.

  The pH during the polymerization in the copolymerization is preferably acidic. In particular, when persulfate and bisulfite are used in combination as the initiator, it is preferably carried out under acidic conditions. By carrying out under acidic conditions, the increase in the viscosity of the aqueous solution of the polymerization reaction system can be suppressed, and the copolymer can be produced favorably. In addition, since the polymerization reaction can proceed under high concentration conditions, the production efficiency can be greatly increased, and the final solid content concentration can be high concentration polymerization of 40% or more, and the residual contained A monomer having a total monomer concentration of 15000 ppm or less can be obtained. Furthermore, the polymerizability of the ether bond-containing monomer can be improved.

  As said acidic condition, it is preferable that pH at 25 degreeC of the reaction solution in superposition | polymerization is 1-6. More preferably, it is 5 or less, More preferably, it is 3 or less. The copolymer obtained by the above copolymerization method can be used as it is as a main component of a detergent composition (detergent builder) or the like, but may be further neutralized with an alkaline substance if necessary. As the alkaline substance, it is preferable to use inorganic salts such as hydroxides, chlorides and carbonates of monovalent metals and divalent metals; ammonia; organic ammonium (organic amine) and the like.

  The neutralization rate at the time of copolymerization can be appropriately changed depending on the initiator. For example, when persulfate and bisulfite are used in combination, when the monomer is capable of forming a salt, the neutralization rate of the carboxyl group-containing monomer is 0 to 60 mol%, It is preferable to copolymerize body components. The neutralization rate of the monomer is represented by mol% of the monomer forming the salt when the total number of moles of the monomer is 100 mol%. If the neutralization rate of the monomer exceeds 60 mol%, the polymerization rate in the copolymerization step does not increase, and the molecular weight of the resulting copolymer may decrease, or the production efficiency may decrease. More preferably, it is 50 mol% or less, more preferably 40 mol% or less, particularly preferably 30 mol% or less, more particularly preferably 20 mol% or less, and most preferably 10 mol%. It is as follows.

  Examples of a method for carrying out the copolymerization with the neutralization rate of the monomer being 0 to 60 mol% include, for example, when the monomer is an unsaturated carboxylic acid monomer, all of which are unsaturated acid carboxylic acid When neutralizing monomeric unsaturated carboxylic acid monomers into salt forms such as sodium salts and ammonium salts using alkaline substances A method in which a neutralization rate of 0 to 60 mol% is added to the copolymer is suitable.

  The above polyalkylene glycol copolymer (or polymer composition) is a water treatment agent, fiber treatment agent, dispersant, detergent builder (or detergent composition), scale inhibitor (scale inhibitor), metal ion sealing. It can be used as an agent, thickener, various binders, emulsifiers, skin care agents, hair care agents and the like. As a detergent builder, it can be used by adding to detergents for various uses such as clothing, tableware, residential, hair, body, toothpaste, and automobile.

<Water treatment agent>
The polyalkylene glycol copolymer (or polymer composition) of the present invention can be used as a water treatment agent. If necessary, the water treatment agent may contain a polymerized phosphate, phosphonate, anticorrosive, slime control agent, and chelating agent as other compounding agents.

  The water treatment agent is useful for scale prevention in a cooling water circulation system, a boiler water circulation system, a seawater desalination apparatus, a pulp digester, a black liquor concentration tank, and the like. Further, any appropriate water-soluble polymer may be included as long as it does not affect the performance and effects.

<Fiber treatment agent>
The polyalkylene glycol copolymer (or polymer composition) of the present invention can be used as a fiber treatment agent. The fiber treatment agent includes at least one selected from the group consisting of a dye, a peroxide, and a surfactant, and the polyalkylene glycol copolymer (or polymer composition) of the present invention.

  The content of the polyalkylene glycol copolymer of the present invention in the fiber treatment agent is preferably 1 to 100% by weight, more preferably 5 to 100% by weight, based on the entire fiber treatment agent. Further, any appropriate water-soluble polymer may be included as long as the performance and effects are not affected.

  Below, the compounding example of the fiber processing agent which is closer to embodiment is shown. This fiber treatment agent can be used in the steps of refining, dyeing, bleaching and soaping in fiber treatment. Examples of dyeing agents, peroxides and surfactants include those usually used for fiber treatment agents.

  The blending ratio of the polyalkylene glycol copolymer of the present invention to at least one selected from the group consisting of a dye, a peroxide and a surfactant is, for example, the whiteness of the fiber, the color unevenness, the dyeing tempering degree. In order to improve the above, at least 1 selected from the group consisting of a dye, a peroxide and a surfactant with respect to 1 part by weight of the polyalkylene glycol copolymer of the present invention in terms of a pure amount of the fiber treatment agent. It is preferable to use the composition which mix | blended one in the ratio of 0.1-100 weight part as a fiber processing agent.

  Arbitrary appropriate fiber can be employ | adopted as a fiber which can use the said fiber processing agent. Examples thereof include cellulosic fibers such as cotton and hemp, chemical fibers such as nylon and polyester, animal fibers such as wool and silk, semi-synthetic fibers such as human silk, and woven fabrics and blended products thereof.

When the fiber treatment agent is applied to the refining process, it is preferable to blend the polyalkylene glycol copolymer of the present invention with an alkali agent and a surfactant. When applied to the bleaching step, it is preferable to blend the polyalkylene glycol copolymer of the present invention, a peroxide, and a silicic acid-based agent such as sodium silicate as a decomposition inhibitor for the alkaline bleaching agent.
<Inorganic pigment dispersant>
The polyalkylene glycol copolymer (or polymer composition) of the present invention can be used as an inorganic pigment dispersant. In the inorganic pigment dispersant, condensed phosphoric acid and its salt, phosphonic acid and its salt, and polyvinyl alcohol may be used as other compounding agents as required.

  The content of the polyalkylene glycol copolymer of the present invention in the inorganic pigment dispersant is preferably 5 to 100% by weight with respect to the whole inorganic pigment dispersant. Further, any appropriate water-soluble polymer may be included as long as it does not affect the performance and effect.

  The inorganic pigment dispersant can exhibit good performance as a dispersant for heavy or light calcium carbonate or clay inorganic pigment used in paper coating. For example, by adding a small amount of an inorganic pigment dispersant to an inorganic pigment and dispersing it in water, high concentration calcium carbonate having low viscosity and high fluidity and good aging stability of their performance. High concentration inorganic pigment slurries such as slurries can be produced.

  When the inorganic pigment dispersant is used as a dispersant for an inorganic pigment, the amount of the inorganic pigment dispersant used is preferably 0.05 to 2.0 parts by weight with respect to 100 parts by weight of the inorganic pigment. When the amount of the inorganic pigment dispersant used is within the above range, a sufficient dispersion effect can be obtained, and an effect commensurate with the addition amount can be obtained, which can be economically advantageous.

<Detergent composition>
The polyalkylene glycol copolymer (or polymer composition) of the present invention can also be added to a detergent composition.

  The content of the polyalkylene glycol copolymer in the detergent composition is not particularly limited. However, from the viewpoint that excellent builder performance can be exhibited, the content of the polyalkylene glycol copolymer is preferably 0.1 to 15% by mass, more preferably, based on the total amount of the detergent composition. Is 0.3-10 mass%, More preferably, it is 0.5-5 mass%.

  Detergent compositions used in detergent applications usually include surfactants and additives used in detergents. Specific forms of these surfactants and additives are not particularly limited, and conventionally known knowledge can be appropriately referred to in the detergent field. The detergent composition may be a powder detergent composition or a liquid detergent composition.

  The surfactant is one or more selected from the group consisting of an anionic surfactant, a nonionic surfactant, a cationic surfactant and an amphoteric surfactant. When two or more kinds are used in combination, the total amount of the anionic surfactant and the nonionic surfactant is preferably 50% by mass or more, more preferably 60% by mass with respect to the total amount of the surfactant. Or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more.

  Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl ether sulfate, alkenyl ether sulfate, alkyl sulfate, alkenyl sulfate, α-olefin sulfonate, α-sulfo fatty acid or ester salt, alkane sulfonate. , Saturated fatty acid salt, unsaturated fatty acid salt, alkyl ether carboxylate, alkenyl ether carboxylate, amino acid type surfactant, N-acyl amino acid type surfactant, alkyl phosphate ester or salt thereof, alkenyl phosphate ester or Its salts are preferred. An alkyl group such as a methyl group may be branched from the alkyl group or alkenyl group in these anionic surfactants.

  Nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyethylene alkyl phenyl ethers, higher fatty acid alkanolamides or alkylene oxide adducts thereof, sucrose fatty acid esters, alkyl glycoxides, fatty acid glycerin monoesters. Esters, alkylamine oxides and the like are preferred. An alkyl group such as a methyl group may be branched from the alkyl group or alkenyl group in these nonionic surfactants.

  As the cationic surfactant, a quaternary ammonium salt or the like is suitable. As the amphoteric surfactant, a carboxyl type amphoteric surfactant, a sulfobetaine type amphoteric surfactant, and the like are suitable. The alkyl group and alkenyl group in these cationic surfactants and amphoteric surfactants may be branched from an alkyl group such as a methyl group.

  The blending ratio of the surfactant is usually 10 to 60% by mass, preferably 15 to 50% by mass, more preferably 20 to 45% by mass, particularly preferably based on the total amount of the detergent composition. Is 25-40 mass%. If the surfactant content is too small, sufficient detergency may not be achieved, and if the surfactant content is too high, the economy may be reduced.

  Additives include anti-redeposition agent to prevent redeposition of contaminants such as alkali builder, chelate builder, sodium carboxymethyl cellulose, stain inhibitor such as benzotriazole and ethylene-thiourea, soil release agent, color transfer Inhibitors, softeners, alkaline substances for pH adjustment, fragrances, solubilizers, fluorescent agents, colorants, foaming agents, foam stabilizers, polishes, bactericides, bleaching agents, bleaching aids, enzymes, dyes A solvent or the like is preferable. In the case of a powder detergent composition, it is preferable to blend zeolite.

  The detergent composition may contain other detergent builder in addition to the polyalkylene glycol copolymer (or polymer composition) of the present invention. Examples of other detergent builders include, but are not limited to, alkali builders such as carbonates, hydrogen carbonates, and silicates, tripolyphosphates, pyrophosphates, bow glass, nitrilotriacetate, ethylenediaminetetraacetate, Examples thereof include acid salts, (meth) acrylic acid copolymer salts, acrylic acid-maleic acid copolymers, chelate builders such as fumarate and zeolite, and carboxyl derivatives of polysaccharides such as carboxymethylcellulose. Examples of the counter salt used in the builder include alkali metals such as sodium and potassium, ammonium and amine.

  The total blending ratio of the additive and other builder for detergent is usually preferably 0.1 to 50% by mass with respect to 100% by mass of the cleaning composition. More preferably, it is 0.2-40 mass%, More preferably, it is 0.3-35 mass%, Most preferably, it is 0.4-30 mass%, Most preferably, it is 0.5-20 mass% or less. It is. If the additive / other detergent builder content is less than 0.1% by mass, sufficient detergent performance may not be achieved, and if it exceeds 50% by mass, the economy may be reduced.

  In addition, the concept of the above-mentioned detergent composition includes specific detergents such as synthetic detergents for household detergents, textile industry and other industrial detergents, hard surface cleaners, and bleaching detergents that enhance one of the components. Detergents that are only used are also included.

  When the detergent composition is a liquid detergent composition, the amount of water contained in the liquid detergent composition is usually preferably 0.1 to 75% by mass, more preferably based on the total amount of the liquid detergent composition. Is 0.2 to 70% by mass, more preferably 0.5 to 65% by mass, even more preferably 0.7 to 60% by mass, particularly preferably 1 to 55% by mass, Preferably it is 1.5-50 mass%.

When the detergent composition is a liquid detergent composition, the detergent composition preferably has a kaolin turbidity of 200 mg / L or less, more preferably 150 mg / L or less, and even more preferably 120 mg / L or less. Especially preferably, it is 100 mg / L or less, Most preferably, it is 50 mg / L or less.
<Measurement method of kaolin turbidity>
A sample (liquid detergent) uniformly stirred in a 50 mm square cell having a thickness of 10 mm was removed and air bubbles were removed. Then, a NDU2000 manufactured by Nippon Denshoku Co., Ltd. Kaolin turbidity: mg / L) is measured.
Proteases, lipases, cellulases, and the like are suitable as enzymes that can be incorporated into the cleaning composition. Of these, proteases, alkaline lipases, and alkaline cellulases that are highly active in an alkaline cleaning solution are preferred.
The amount of the enzyme added is preferably 5% by mass or less with respect to 100% by mass of the cleaning composition. If it exceeds 5% by mass, improvement in detergency cannot be seen, and the economy may be reduced.
As the alkali builder, silicate, carbonate, sulfate and the like are preferable. As the chelate builder, diglycolic acid, oxycarboxylate, EDTA (ethylenediaminetetraacetic acid), DTPA (diethylenetriaminepentaacetic acid), STPP (sodium tripolyphosphate), citric acid and the like are preferable. Other water-soluble polycarboxylic acid-based polymers other than the copolymer in the present invention may be used.
The above detergent composition is excellent in precipitation suppressing ability, and further has a very high quality and excellent stability that is less likely to cause deterioration in performance when stored for a long period of time and precipitation of impurities when held at a low temperature. it can.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.
Moreover, the weight average molecular weight, inhibitory ability, etc. of the polyalkylene glycol copolymer of this invention were measured in accordance with the following method.

<Measurement conditions of weight average molecular weight>
Equipment: Hitachi L-7000 series detector: RI
Column: SHODEX Asahipak GF-310-HQ, GF-710-HQ, GF-1G 7B manufactured by Showa Denko KK
Column temperature: 40 ° C
Flow rate: 0.5 ml / min.
Calibration curve: POLYACRYLIC ACID STANDARD made by Soka Science Co., Ltd.
Eluent: 0.1N sodium acetate / acetonitrile = 3/1 (mass ratio)
<Method for quantifying polyoxyalkylene glycol monomers>
Quantification of the polyoxyalkylene glycol monomer and the like was performed by high-speed chromatography under the following conditions.
High-performance liquid chromatography measuring device: 8020 series manufactured by Tosoh Corporation Column: CAPCELL PAK C1 UG120 manufactured by Shiseido Co., Ltd.
Temperature: 40.0 ° C
Eluent: 10 mmol / L Disodium hydrogen phosphate.12 hydrate aqueous solution (adjusted to pH 7 with phosphoric acid) / acetonitrile = 45/55 (volume ratio)
Flow rate: 1.0 ml / min
Detector: RI, UV (detection wavelength 215 nm)
<Method for quantifying carboxyl group-containing monomers>
The quantification of the carboxyl group-containing monomer and the like was performed using liquid chromatography under the conditions shown in Table 1 below.
Measuring device: L-7000 series detector manufactured by Hitachi, Ltd .: UV detector L-7400 manufactured by Hitachi, Ltd.
Column: SHODEX RSpak DE-413 manufactured by Showa Denko Co., Ltd.
Temperature: 40.0 ° C
Eluent: 0.1% phosphoric acid aqueous solution Flow rate: 1.0 ml / min
<Measuring method of precipitation inhibitory ability (LAS-Ca salt precipitation inhibitory ability)>
(1) A pure glycine buffer solution was prepared by adding pure water to 9.3793 g of glycine, 9.6252 g of sodium chloride, and 5.1975 g of sodium hydroxide.
(2) Pure water was added to 1.50 g of 15% (w / w) sodium dodecylbenzenesulfonate (LAS) aqueous solution, 0.80 g of sodium sulfate, and 11.25 g of glycine buffer prepared in (1), and 500. 0 g.
(3) A 0.1% (w / w) sample polymer aqueous solution was prepared.
(4) A 1M calcium chloride dihydrate aqueous solution was prepared.
(5) A test solution was prepared by adding 1.80 g of the 0.1% sample polymer aqueous solution prepared in (3), 8.20 g of pure water, and 80.00 g of (2) to a 100 mL beaker.
(6) To the test solution, the 1M calcium chloride dihydrate aqueous solution prepared in (4) was dropped and stirred, and the change in turbidity was measured. For the measurement, an automatic titrator manufactured by Hiranuma Sangyo (main body: COM-550, luminous intensity unit; M-500) was used. Turbidity change was measured by transmittance change at a wavelength of 650 nm.
(7) The transmittance value at the time when the addition amount of the 1M calcium chloride dihydrate aqueous solution was 0.270 ml was defined as the precipitation inhibiting ability. In addition, it means that it is excellent in precipitation suppression ability, so that a value is high.

<Method for measuring solid content of polymer composition>
In a nitrogen atmosphere, the polymer composition (polymer composition 1.0 g + water 3.0 g) was left to dry for 1 hour in an oven heated to 130 ° C. From the weight change before and after drying, the solid content (%) and the volatile component (%) were calculated.

<Monomer Synthesis Example 1>
Into a 500 mL glass separable flask equipped with a stirrer (paddle blade), 125.2 g of New Coal 2310 (manufactured by Nippon Emulsifier Co., Ltd .; ethylene oxide 10 mol adduct of C12-13 alcohol), The reaction system was dehydrated by charging 16.8 g, heating up to 120 ° C. with nitrogen blowing and stirring, and maintaining this state for 1 hour. Next, a reflux condenser was attached, and the temperature was lowered to 60 ° C., 27.0 g of methallyl chloride (hereinafter also referred to as “MLC”) was added over 30 minutes, and then reacted for 5 hours. 200.0 g of pure water was added thereto, and the mixture was reacted for 1 hour, and then neutralized with sulfuric acid. After cooling to room temperature, this aqueous solution was transferred to a 500 ml separatory funnel and allowed to stand until the layers were separated, and the lower layer was removed. The remaining upper layer was transferred to a 300 ml eggplant flask and desolvated with a rotary evaporator. Precipitated salt was removed by filtration to obtain monomer 1.

<Example 1>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 89.0 g of pure water and 0.0125 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, 212.5 g of an 80% aqueous acrylic acid solution (hereinafter also referred to as “80% AA”) and an aqueous 48% sodium hydroxide solution (hereinafter referred to as “48”) in a polymerization reaction system maintained at 90 ° C. with stirring. 9.8 g, 30.0 g of monomer 1, 48.1 g of 15% aqueous sodium persulfate solution (hereinafter also referred to as “15% NaPS”), and 35% aqueous sodium bisulfite solution (also referred to as “% NaOH”) Hereinafter, it is also referred to as “35% SBS”.) 34.4 g was dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 90 minutes for monomer 1, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, 167.2 g of 48% NaOH was gradually added dropwise while stirring and allowing the polymerization reaction liquid to cool, thereby neutralizing the polymerization reaction liquid.
Thus, an aqueous solution (polyalkylene glycol copolymer composition 1) of polymer 1 (polyalkylene glycol copolymer 1) having a solid content concentration of 45.5% and a weight average molecular weight of 8500 was obtained.

<Example 2>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 113.0 g of pure water and 0.0121 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, in a polymerization reaction system maintained at 90 ° C. with stirring, 175.0 g of 80% AA, 8.1 g of 48% NaOH, 60.0 g of monomer 1 and 40.7 g of 15% NaPS And 40.7 g of 35% SBS were dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 90 minutes for monomer 1, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, while stirring and allowing the polymerization reaction liquid to cool, 487.7% NaOH 137.7 g was gradually added dropwise to neutralize the polymerization reaction liquid.
Thus, an aqueous solution (polyalkylene glycol copolymer composition 2) of polymer 2 (polyalkylene glycol copolymer 2) having a solid content concentration of 45.6% and a weight average molecular weight of 9400 was obtained.

<Monomer Synthesis Example 2>
To a glass separable flask with a capacity of 1000 mL equipped with a stirrer (paddle blade), 425.6 g of New Coal 2320 (manufactured by Nippon Emulsifier Co., Ltd .; ethylene oxide 20 mol adduct of C12-13 alcohol) and 35.3 g of KOH While charging, blowing nitrogen, and stirring, the temperature was raised to 120 ° C., and this state was maintained for 1 hour to dehydrate the reaction system. Next, a reflux condenser was attached, the temperature was lowered to 60 ° C., 54.0 g of MLC was added over 30 minutes, and then reacted for 5 hours. Further, 50.0 g of pure water was added and reacted for 1 hour, and then neutralized with sulfuric acid. After cooling to room temperature, this aqueous solution was transferred to a 1000 ml eggplant flask and desolvated with a rotary evaporator. Ethanol was added thereto, and the precipitated salt was removed by filtration. This series of desalting operations was repeated three times, and the solvent was completely removed to obtain monomer 2.

<Example 3>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 89.0 g of pure water and 0.0124 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, in a polymerization reaction system maintained at 90 ° C. with stirring, 212.5 g of 80% AA, 9.8 g of 48% NaOH, 30.0 g of monomer 2, and 47.8 g of 15% NaPS. , And 34.1 g of 35% SBS were added dropwise from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 150 minutes for monomer 2, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, 167.2 g of 48% NaOH was gradually added dropwise while stirring and allowing the polymerization reaction liquid to cool, thereby neutralizing the polymerization reaction liquid.
Thus, an aqueous solution (polyalkylene glycol copolymer composition 3) of polymer 3 (polyalkylene glycol copolymer 3) having a solid content concentration of 45.8% and a weight average molecular weight of 8800 was obtained.

<Example 4>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 117.0 g of pure water and 0.0121 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, in a polymerization reaction system maintained at 90 ° C. with stirring, 175.0 g of 80% AA, 8.1 g of 48% NaOH, 60.0 g of monomer 2 and 40.0 g of 15% NaPS And 22.8 g of 35% SBS were dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 120 minutes for monomer 2, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, while stirring and allowing the polymerization reaction liquid to cool, 487.7% NaOH 137.7 g was gradually added dropwise to neutralize the polymerization reaction liquid.
Thus, an aqueous solution (polyalkylene glycol-based copolymer composition 4) of polymer 4 (polyalkylene glycol-based copolymer 4) having a solid content concentration of 46.0% and a weight average molecular weight of 9,500 was obtained.

<Monomer Synthesis Example 3>
In a 1000 mL glass separable flask equipped with a stirrer (paddle blade), 480.1 g of New Coal 2360 (manufactured by Nippon Emulsifier Co., Ltd .; ethylene oxide 60 mol adduct of C12-13 alcohol) and 15.0 g of KOH were added. While charging, blowing nitrogen, and stirring, the temperature was raised to 120 ° C., and this state was maintained for 1 hour to dehydrate the reaction system. Next, a reflux condenser was attached, the temperature was lowered to 60 ° C., 23.0 g of MLC was added over 30 minutes, and then reacted for 5 hours. Further, 50.0 g of pure water was added and reacted for 1 hour, and then neutralized with sulfuric acid. After cooling to room temperature, this aqueous solution was transferred to a 1000 ml eggplant flask and desolvated with a rotary evaporator. Ethanol was added thereto, and the precipitated salt was removed by filtration. This series of desalting operations was repeated three times, and the solvent was completely removed to obtain monomer 3.

<Example 5>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 115.0 g of pure water and 0.0120 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, in a polymerization reaction system maintained at 90 ° C. with stirring, 175.0 g of 80% AA, 8.1 g of 48% NaOH, 60.0 g of monomer 3, and 39.3 g of 15% NaPS. And 33.7 g of 35% SBS were added dropwise from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 120 minutes for monomer 3, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, while stirring and allowing the polymerization reaction liquid to cool, 487.7% NaOH 137.7 g was gradually added dropwise to neutralize the polymerization reaction liquid.
Thus, an aqueous solution (polyalkylene glycol copolymer composition 5) of polymer 5 (polyalkylene glycol copolymer 5) having a solid content concentration of 45.9% and a weight average molecular weight of 9800 was obtained.

<Example 6>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 152.0 g of pure water and 0.0119 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, 125.0 g of 80% AA, 5.8 g of 48% NaOH, 100.0 g of monomer 3 and 28.5 g of 15% NaPS in a polymerization reaction system maintained at 90 ° C. with stirring. , And 24.4 g of 35% SBS were dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 90 minutes for monomer 3, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, 98.3 g of 48% NaOH was gradually added dropwise while stirring and allowing the polymerization reaction liquid to cool, thereby neutralizing the polymerization reaction liquid.
Thus, an aqueous solution (polyalkylene glycol-based copolymer composition 6) of polymer 6 (polyalkylene glycol-based copolymer 6) having a solid content concentration of 46.4% and a weight average molecular weight of 10,000 was obtained.

<Comparative Example 1>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 116.0 g of pure water and 0.0119 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, in a polymerization reaction system maintained at 90 ° C. with stirring, 175.0 g of 80% AA, 8.1 g of 48% NaOH, and 25 mol of an isoprenol ethylene oxide adduct (hereinafter also referred to as “IPN25”) 60. 0 g, 15% NaPS 39.9 g, and 35% SBS 28.5 g were added dropwise from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 150 minutes for IPN25, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.

  After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, while stirring and allowing the polymerization reaction liquid to cool, 487.7% NaOH 137.7 g was gradually added dropwise to neutralize the polymerization reaction liquid.

  Thus, an aqueous solution of Comparative Polymer 1 having a solid content concentration of 45.6% and a weight average molecular weight of 9600 was obtained.

<Monomer Synthesis Example 4>
A glass separable flask having a capacity of 500 mL equipped with a stirrer (paddle blade) was charged with 226.4 g of an ethylene oxide 25 mol adduct (hereinafter also referred to as “PGM25”) and 16.8 g of KOH, and nitrogen was blown into the flask. While stirring, the temperature was raised to 120 ° C., and this state was maintained for 1 hour to dehydrate the reaction system. Next, a reflux condenser was attached, the temperature was lowered to 60 ° C., 27.0 g of MLC was added over 30 minutes, and then reacted for 5 hours. 200.0 g of pure water was added thereto, and the mixture was reacted for 1 hour, and then neutralized with sulfuric acid. After cooling to room temperature, this aqueous solution was transferred to a 500 ml separatory funnel and allowed to stand until the layers were separated, and the lower layer was removed. The remaining upper layer was transferred to a 300 ml eggplant flask and desolvated with a rotary evaporator. Precipitated salt was removed by filtration to obtain monomer 4.

<Comparative example 2>
A 1000 mL glass separable flask equipped with a reflux condenser and a stirrer (paddle blade) was charged with 116.0 g of pure water and 0.0119 g of Mole salt, and the temperature was raised to 90 ° C. while stirring to polymerize the reaction. It was a system. Next, in a polymerization reaction system maintained at 90 ° C. with stirring, 175.0 g of 80% AA, 8.1 g of 48% NaOH, 60.0 g of monomer 4 and 39.9 g of 15% NaPS. , And 28.5 g of 35% SBS were dropped from separate nozzles. The dropping time of each solution was 180 minutes for 80% AA and 48% NaOH, 150 minutes for monomer 4, 185 minutes for 15% NaPS, and 175 minutes for 35% SBS. Moreover, the dropping rate of each solution was made constant, and each solution was dropped continuously.
After the completion of the dropwise addition of 80% AA, the reaction solution was kept at 90 ° C. (ripening) for 30 minutes to complete the polymerization. After completion of the polymerization, while stirring and allowing the polymerization reaction liquid to cool, 487.7% NaOH 137.7 g was gradually added dropwise to neutralize the polymerization reaction liquid.
Thus, an aqueous solution of Comparative Polymer 2 having a solid content concentration of 46.1% and a weight average molecular weight of 9800 was obtained.

<Example 7>
Next, the precipitation suppression ability of the polymers of Examples 1 to 6 and Comparative Examples 1 to 2 was evaluated according to the above evaluation method. The results are summarized in Table 1.

As is apparent from Table 1, the copolymer in the present invention is significantly superior in precipitation inhibiting ability as compared with the comparative copolymer including the comparative polymer not having the structural unit (a) of the present invention. have. Therefore, it can be preferably used as a detergent additive.

Claims (2)

4% by mass or more and less than 50% by mass of the structural unit (a) derived from the polyalkylene glycol monomer (A) represented by the following formula (1),

In the general formula (1), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group or a single bond, Z represents an oxyalkylene structure having 2 to 30 carbon atoms, 50 mol% or more has an oxyethylene structure, n represents a number of more than 5 and 300 or less, R ₁ represents an alkyl group having 8 to 20 carbon atoms, an aryl group, or an alkenyl group, and 50 mass% or more A polyalkylene glycol copolymer having a weight average molecular weight of 1,500 to 60,000 having a structural unit (b) derived from a carboxyl group-containing monomer (B) of less than 96% by mass as an essential constituent unit. 4% by mass or more and less than 50% by mass of the polyalkylene glycol monomer (A) represented by the following formula (1),

In the general formula (1), R ₀ represents a hydrogen atom or a CH ₃ group, R represents a CH ₂ group or a single bond, Z represents an oxyalkylene structure having 2 to 30 carbon atoms, 50 mol% or more has an oxyethylene structure, n represents a number of more than 5 and 300 or less, R ₁ represents an alkyl group having 8 to 20 carbon atoms, an aryl group, or an alkenyl group, and 50 mass% or more A method for producing a polyalkylene glycol copolymer having a weight average molecular weight of 1,500 to 60,000, wherein the polymerization is carried out in the presence of a polymerization initiator essentially comprising less than 96% by mass of a carboxyl group-containing monomer (B).