JP2014073929A - Polyalkylene glycol-based block copolymer, dispersant, cement admixture and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolymer capable of exhibiting water-reducing property, workability and the like in a cement composition and the like at high level, and having a simple molecular structure.SOLUTION: A polyalkylene glycol-based block copolymer has an essential structure in which a polymer chain by unsaturated carboxylic acid-based monomer units (A) and a polymer chain by monoalkoxypolyalkylene glycol-based constitutional units (B) are bound through a binding site (X) and in which the polymer chain (A) and the polymer chain (B) are bound in an order of the polymer chain (A) and the polymer chain (B) through the binding site (X), an average introduced molar number of the unsaturated carboxylic acid units in the polymer chain (A) is 20 or more, a terminal of the polymer chain (A) not binding to the binding site (X) is a hydrogen, an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and an average addition molar number of an oxyalkylene group of the polyalkylene glycol-based constitutional units in the polymer chain (B) is 75 or more.

Description

The present invention relates to a polyalkylene glycol block copolymer. More specifically, the present invention relates to a polyalkylene glycol block copolymer suitably used for a dispersant, a cement admixture and the like.

A polymer containing a polyalkylene glycol chain (hereinafter, also referred to as a polyalkylene glycol polymer) has properties such as hydrophilicity, hydrophobicity, and steric repulsion by appropriately adjusting the chain length and the constituent alkylene oxide. Cement admixture applications that are applied and added to cement compositions such as cement paste, mortar, concrete, etc. are being studied. Such a cement admixture is usually used as a water reducing agent or the like, and exerts the action of improving the strength and durability of the cured product by reducing the cement composition by increasing the fluidity of the cement composition. Used for that purpose. As a water reducing agent, a water reducing agent such as a naphthalene type has been conventionally used. However, since the polyalkylene glycol chain can act as a dispersing group for dispersing cement particles due to its steric repulsion, it contains a polyalkylene glycol chain. The polycarboxylic acid-based water reducing agent has been newly proposed as exhibiting a high water reducing action, and has recently been used as a high-performance AE water reducing agent.

With respect to a conventional polymer containing a polyalkylene glycol chain, for example, a copolymer obtained by block polymerization of methacrylic acid at both ends / one end of a polyalkylene glycol chain (for example, see Patent Document 1) is disclosed.
Also disclosed is a copolymer produced by atom transfer radical polymerization (ATRP polymerization) in the form of a copolymer of a poly (alkylene oxide) compound and an ethylenically unsaturated monomer compound (see, for example, Patent Document 2). ing.
In addition, as a biodegradable water-soluble polymer used in detergent builders, a monoethylenically unsaturated monomer component is blocked or grafted to a modified polyether compound in which a compound having a mercapto group is introduced into a polyether compound by an ester reaction. A polymer obtained by polymerization is disclosed (for example, see Patent Document 3). Furthermore, it is disclosed that a novel polymer having a polymer unit comprising a polyalkylene glycol chain and a constituent unit derived from an unsaturated monomer bonded to at least one end of the chain is particularly useful as a cement admixture. (For example, refer to Patent Document 4).

US Pat. No. 6,248,839 US Pat. No. 7,425,596 JP-A-7-109487 JP 2007-119736 A

As described above, polymers having various structures have been disclosed as polyalkylene glycol chain-containing polymers. However, the extremely high performance (cement dispersibility (water-reducing), slump flow) required recently is still sufficient. It has not reached the level where it can be demonstrated. Cement dispersibility is a very important factor related to workability in the field of handling cement and strength after hardening of cement, and a cement admixture that realizes a cement composition with better performance is required. .
In particular, there is a need for a cement admixture that has a simple molecular structure and manufacturing method and exhibits excellent characteristics.

The present invention has been made in view of the above situation, and provides a copolymer having a simple molecular structure capable of exhibiting performance such as water reduction and workability in a cement composition at a high level. For the purpose.

The inventors of the present invention have made various studies on polymers that can be used as cement admixtures having excellent performance such as cement dispersibility (water-reducing properties). As a result, polymer chains (A) composed of unsaturated carboxylic acid monomer units and , A polyalkylene glycol block copolymer having a structure in which a polymer chain (B) of a monoalkoxy polyalkylene glycol-based structural unit is bonded via a bonding site (X), the polymer chain (A ) And the polymer chain (B) are bonded via the binding site (X) in the order of the polymer chain (A) and the polymer chain (B), and the polymer chain (A) is unsaturated. The average number of moles of carboxylic acid monomer units introduced is 20 or more, and the terminal of the polymer chain (A) not bonded to the bonding site (X) is hydrogen, an alkyl group having 1 to 10 carbon atoms, or the number of carbon atoms 1-10 alkenyl groups, high A copolymer having a structure in which the average number of added moles of oxyalkylene groups of the polyalkylene glycol structural unit in the chain (B) is 75 or more is cement dispersibility (water reduction) and slump flow despite a simple structure. It has been found that the polymer is excellent in properties such as, and can be suitably used as a cement admixture.
In addition, the present inventors have found that a polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and a polymer chain (B) composed of a monoalkoxypolyalkylene glycol-based structural unit are connected via a binding site (X). A polyalkylene glycol block copolymer having a structure bonded to each other, and having a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 1 to 10 carbon atoms at the terminal on the polymer chain (A) side A copolymer having a structure in which the average number of moles of oxyalkylene group added is 75 to 500 and the average number of moles of unsaturated carboxylic acid monomer units introduced is 20 to 500 is also a simple structure. Nevertheless, it has been found that the polymer is excellent in properties such as cement dispersibility (water reducing property) and slump flow, and can be suitably used as a cement admixture.
Furthermore, the inventors of the present invention have a polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and a polymer chain (B) composed of a monoalkoxypolyalkylene glycol-based structural unit via a binding site (X). A polyalkylene glycol block copolymer having a structure bonded to each other, wherein the average number of moles of unsaturated carboxylic acid monomer units introduced in the polymer chain (A) is 20 or more, and high A copolymer having an average addition mole number of oxyalkylene groups of the polyalkylene glycol-based structural unit in the molecular chain (B) of 120 or more can also be used for cement dispersibility (water reduction), slump flow, etc. despite its simple structure. It has been found that the polymer is excellent in properties and can be suitably used as a cement admixture.

（式中、Ｘは、有機残基を表す。ＡＯは、同一又は異なって、炭素数２〜１８のオキシアルキレン基を表す。Ｒ^１は、炭素数１〜１０のアルキル基又は炭素数１〜１０のアルケニル基を表す。Ｒ^２は、水素原子、炭素数１〜１０のアルキル基又は炭素数１〜１０のアルケニル基を表す。Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６は、少なくとも一つが−ＣＯＯＭ^１であり、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６は、同一又は異なって、水素原子、炭素数１〜１０のアルキル基、−（ＣＨ_２）ｚＣＯＯＭ^２（−（ＣＨ_２）ｚＣＯＯＭ^２は、ＣＯＯＭ^１またはその他の−（ＣＨ_２）ｚＣＯＯＭ^２と無水物を形成していてもよい）を表し、ｚは０〜２の整数を表す。ｎは、オキシアルキレン基の平均付加モル数を表し、７５〜５００の数である。ｍは、２０〜５００の数である。Ｍ^１及びＭ^２は同一又は異なって、水素原子、一価金属、二価金属、三価金属、第４級アンモニウム基、又は、有機アミン基を表す。）
で表される構造を有することを特徴とするポリアルキレングリコール系ブロック共重合体である。
また、第三の本発明は、不飽和カルボン酸系単量体単位による高分子鎖（Ａ）と、モノアルコキシポリアルキレングリコール系構成単位による高分子鎖（Ｂ）とが結合部位（Ｘ）を介して結合した構造を必須とするポリアルキレングリコール系ブロック共重合体であって、上記ポリアルキレングリコール系ブロック共重合体は、
上記高分子鎖（Ａ）における不飽和カルボン酸系単量体単位の平均導入モル数が２０以上であり、かつ、上記高分子鎖（Ｂ）におけるポリアルキレングリコール系構成単位のオキシアルキレン基の平均付加モル数が１２０以上であることを特徴とするポリアルキレングリコール系ブロック共重合体である。
以下、本明細書中において、単に「本発明」という場合には第一、第二及び第三の本発明に共通する事項を意味するものとする。
以下、第一の本発明と第二の本発明についてまとめて説明し、その後に第三の本発明について説明する。
第三の本発明の説明においては第一の本発明及び第二の本発明と異なる技術的特徴について説明する。
なお、以下において記載する本発明の個々の好ましい形態を２つ以上組み合わせたものもまた、本発明の好ましい形態である。 That is, in the first aspect of the present invention, the polymer chain (A) based on the unsaturated carboxylic acid monomer unit and the polymer chain (B) based on the monoalkoxypolyalkylene glycol structural unit are bonded via the bonding site (X). A polyalkylene glycol-based block copolymer essentially having a bonded structure,
The polyalkylene glycol block copolymer is
The polymer chain (A) and the polymer chain (B) have a structure in which the polymer chain (A) and the polymer chain (B) are bonded in this order via the binding site (X),
The average number of moles of the unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the terminal of the polymer chain (A) not bonded to the binding site (X) is hydrogen. , An alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and the average added mole number of the oxyalkylene group of the polyalkylene glycol structural unit in the polymer chain (B) is 75 or more. Is a polyalkylene glycol block copolymer.
In the second aspect of the present invention, the polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and the polymer chain (B) composed of a monoalkoxypolyalkylene glycol unit constitute a binding site (X). A polyalkylene glycol block copolymer essentially having a structure bonded via the polyalkylene glycol block copolymer,
The following general formula (1):

(In the formula, X represents an organic residue. AO is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. R ¹ is an alkyl group having 1 to 10 carbon atoms or 1 to 1 carbon atoms. R ² represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 1 to 10 carbon atoms, wherein at least one of R ³ , R ⁴ , R ⁵ , and R ⁶ is -COOM ¹ and R ³ , R ⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,-(CH ₂ ) zCOOM ² (-(CH ₂ ) zCOOM ² represents COOM ¹ or other — (CH ₂ ) zCOOM ² and may form an anhydride), and z represents an integer of 0 to 2. n is the average number of moles of oxyalkylene group added. Represents a number from 75 to 500. m is from 20 to 20. And M ¹ and M ² are the same or different and each represents a hydrogen atom, a monovalent metal, a divalent metal, a trivalent metal, a quaternary ammonium group, or an organic amine group.
It is a polyalkylene glycol type block copolymer characterized by having the structure represented by these.
Further, in the third aspect of the present invention, the polymer chain (A) based on the unsaturated carboxylic acid monomer unit and the polymer chain (B) based on the monoalkoxypolyalkylene glycol structural unit have a bonding site (X). A polyalkylene glycol block copolymer essentially having a structure bonded via the polyalkylene glycol block copolymer,
The average number of moles of unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the average number of oxyalkylene groups of the polyalkylene glycol constituent units in the polymer chain (B) A polyalkylene glycol block copolymer having an addition mole number of 120 or more.
Hereinafter, in the present specification, the term “present invention” simply means matters common to the first, second and third present inventions.
Hereinafter, the first invention and the second invention will be described together, and then the third invention will be described.
In the description of the third aspect of the present invention, technical features different from the first aspect of the present invention and the second aspect of the present invention will be described.
A combination of two or more preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

（式中、Ｘは、有機残基を表す。ＡＯは、同一又は異なって、炭素数２〜１８のオキシアルキレン基を表す。Ｒ^１は、炭素数１〜１０のアルキル基又は炭素数１〜１０のアルケニル基を表す。Ｒ^２は、水素原子、炭素数１〜１０のアルキル基又は炭素数１〜１０のアルケニル基を表す。Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６は、少なくとも一つが−ＣＯＯＭ^１であり、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６は、同一又は異なって、水素原子、炭素数１〜１０のアルキル基、−（ＣＨ_２）ｚＣＯＯＭ^２（−（ＣＨ_２）ｚＣＯＯＭ^２は、ＣＯＯＭ^１またはその他の−（ＣＨ_２）ｚＣＯＯＭ^２と無水物を形成していてもよい）を表し、ｚは０〜２の整数を表す。ｎは、オキシアルキレン基の平均付加モル数を表し、７５〜５００の数である。ｍは、２０〜５００の数である。Ｍ^１及びＭ^２は同一又は異なって、水素原子、一価金属、二価金属、三価金属、第４級アンモニウム基、又は、有機アミン基を表す。）
で表される構造を有することを特徴とする。 <First Invention and Second Invention>
The polyalkylene glycol block copolymer according to the first aspect of the present invention comprises a polymer chain (A) comprising an unsaturated carboxylic acid monomer unit and a polymer chain (B) comprising a monoalkoxypolyalkylene glycol constituent unit. And a polyalkylene glycol block copolymer which essentially has a structure in which they are bonded via the binding site (X),
The polyalkylene glycol block copolymer is
The polymer chain (A) and the polymer chain (B) have a structure in which the polymer chain (A) and the polymer chain (B) are bonded in this order via the binding site (X),
The average number of moles of the unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the terminal of the polymer chain (A) not bonded to the binding site (X) is hydrogen. , An alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and the average added mole number of the oxyalkylene group of the polyalkylene glycol structural unit in the polymer chain (B) is 75 or more. It is characterized by.
In addition, the polyalkylene glycol block copolymer according to the second invention includes a polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and a polymer chain composed of a monoalkoxy polyalkylene glycol structural unit ( B) is a polyalkylene glycol block copolymer having a structure in which it is bound via the binding site (X),
The polyalkylene glycol block copolymer is
The following general formula (1):

(In the formula, X represents an organic residue. AO is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. R ¹ is an alkyl group having 1 to 10 carbon atoms or 1 to 1 carbon atoms. R ² represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 1 to 10 carbon atoms, wherein at least one of R ³ , R ⁴ , R ⁵ , and R ⁶ is -COOM ¹ and R ³ , R ⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,-(CH ₂ ) zCOOM ² (-(CH ₂ ) zCOOM ² represents COOM ¹ or other — (CH ₂ ) zCOOM ² and may form an anhydride), and z represents an integer of 0 to 2. n is the average number of moles of oxyalkylene group added. Represents a number from 75 to 500. m is from 20 to 20. And M ¹ and M ² are the same or different and each represents a hydrogen atom, a monovalent metal, a divalent metal, a trivalent metal, a quaternary ammonium group, or an organic amine group.
It has the structure represented by these.

<Polymer chain (A) by unsaturated carboxylic acid monomer unit>
In the present invention, the polymer chain (A) based on the unsaturated carboxylic acid monomer unit is a structural unit derived from the unsaturated carboxylic acid monomer.
In particular, the unsaturated carboxylic acid monomer unit in the second invention is a structural unit derived from the monomer (a) (hereinafter also simply referred to as “monomer (a)”). Is preferred.
Further, the unsaturated carboxylic acid monomer unit is obtained by modifying a structural unit derived from another monomer as long as it is a structural unit having the same structure as that derived from the monomer (a). It may be.
As the monomer (a), for example, the following formula (2):

(In the formula, at least one of R ³ , R ⁴ , R ⁵ , and R ⁶ is —COOM ¹ , and R ³ , R ⁴ , R ⁵ , and R ⁶ are the same or different and have a hydrogen atom, carbon number 1 10 alkyl _{^{group, - (CH 2) zCOOM 2}} (- (CH 2) zCOOM 2 is, COOM ¹ or other _- (CH 2) _zCOOM may form a ² and anhydride) represent, z Represents an integer of 0 to 2. M ¹ and M ² are the same or different and each represents a hydrogen atom, a monovalent metal, a divalent metal, a trivalent metal, a quaternary ammonium group, or an organic amine group. Are preferred.
That is, the monomer (a) is an unsaturated carboxylic acid monomer having at least one carboxyl group bonded to a C═C double bond or a salt thereof (—COOM ¹ ).
The structural unit derived from the monomer (a) is a structure in which a polymerizable double bond of the monomer (a) represented by the general formula (2) is opened by a polymerization reaction (double bond (C = C) corresponds to a single bond (-C—C—).
When the monomer (a) becomes a copolymer represented by the general formula (1), the position of at least one carboxyl group bonded to the C═C double bond or a salt thereof (—COOM ¹ ) is particularly It is not limited. It may be the position of the substituent (R ⁵ , R ⁶ ) bonded to the carbon atom bonded to X in the general formula (1), or the substituent bonded to the carbon atom bonded to R ² in the general formula (1) It may be the position of the group (R ³ , R ⁴ ). The position of (—COOM ¹ ) in each monomer unit may be any position of R ³ , R ⁴ , R ⁵ , and R ⁶ .

The unsaturated carboxylic acid monomer unit in the first aspect of the present invention may be a structural unit derived from the monomer (a), but is not limited thereto. The structural unit derived from the body may be modified.

In the general formula (2), examples of the group represented by M ¹ and M ² include monovalent metal atoms such as alkali metal atoms such as lithium, sodium and potassium; alkaline earth metal atoms such as calcium and magnesium And divalent metal atoms such as aluminum and iron. Moreover, as an organic amine group, alkanolamine groups, such as an ethanolamine group, a diethanolamine group, and a triethanolamine group, a triethylamine group etc. are mentioned, for example.

Specific examples of the unsaturated carboxylic acid monomer represented by the general formula (2) include monocarboxylic acid monomers such as acrylic acid, methacrylic acid and crotonic acid, maleic acid, itaconic acid and fumaric acid. Examples thereof include dicarboxylic acid monomers, dicarboxylic acid anhydrides and salts thereof (for example, salts of monovalent metals, divalent metals, trivalent metals, quaternary ammonium or organic amines).
Among these, acrylic acid, methacrylic acid, maleic acid, maleic anhydride and salts thereof are preferable from the viewpoint of polymerizability, and acrylic acid, methacrylic acid and salts thereof are particularly preferable.
Two or more of these monomers may be used in combination.

In the polyalkylene glycol block copolymer according to the present invention, the average number of moles of unsaturated carboxylic acid monomer units introduced into the polymer chain (A) by the unsaturated carboxylic acid monomer units is 20 or more. It is preferable that
In the general formula (1), the average number of moles of unsaturated carboxylic acid monomer units introduced is represented by m.
The lower limit of the average number of moles introduced is 20, preferably 25, more preferably 30, and even more preferably 35. The upper limit is preferably 500, more preferably 300, still more preferably 200, and still more preferably 100.
By setting m to a number of 20 or more, the above-mentioned copolymer can sufficiently exhibit the performance based on the polymer chain (A) based on the unsaturated carboxylic acid monomer unit.
When m exceeds 500, the amount of unsaturated carboxylic acid monomer introduced into the entire copolymer is increased, and as a result, the amount of polyalkylene glycol-based structural units in which the cement is dispersed becomes too small. Dispersion performance will decrease. It is necessary to appropriately set the ratio of the unsaturated carboxylic acid monomer unit to the polyalkylene glycol constituent unit.
The average number of moles of unsaturated carboxylic acid monomer units introduced is the average value of the number of moles of unsaturated carboxylic acid monomer units contained in 1 mole of the polyalkylene glycol block copolymer of the present invention. Means.

Incidentally, ^{R 2} in the general formula (1) represents a hydrogen atom, an alkyl group or alkenyl group having 1 to 10 carbon atoms having 1 to 10 carbon atoms.
R ² is a site corresponding to the polymerization termination terminal of the polymer chain (A) by the unsaturated carboxylic acid monomer unit.
In the polyalkylene glycol block copolymer according to the first aspect of the present invention, the terminal of the polymer chain (A) that is not bonded to the bonding site (X) is hydrogen, an alkyl group having 1 to 10 carbon atoms, or carbon. It is an alkenyl group of formula 1-10.

<Polymer chain (B) by monoalkoxy polyalkylene glycol-based structural unit>
Of the polymer chain (B) of the monoalkoxy polyalkylene glycol-based structural unit, the polyalkylene glycol (hereinafter, polyalkylene glycol is also referred to as PAG) chain structure is composed of alkylene oxide having 2 to 18 carbon atoms. Any polymer chain (polyalkylene oxide) may be used.
Preferred are alkylene oxides having 2 to 8 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, trimethylethylene oxide, tetramethylene oxide, tetramethylethylene oxide, butadiene mono Examples thereof include oxide and octylene oxide. In addition, aliphatic epoxides such as dipentane ethylene oxide and dihexane ethylene oxide; alicyclic epoxides such as trimethylene oxide, tetramethylene oxide, tetrahydrofuran, tetrahydropyran, and octylene oxide; aromatics such as styrene oxide and 1,1-diphenylethylene oxide Epoxides and the like can also be used.

The alkylene oxide constituting the polyalkylene glycol-based structural unit is preferably appropriately selected according to the use required for the polyalkylene glycol-based block copolymer of the present invention. For example, in the production of a cement admixture component Therefore, from the viewpoint of affinity with cement particles, it is preferable that the main component is a relatively short chain alkylene oxide (oxyalkylene group) having about 2 to 8 carbon atoms. More preferably, the main component is an alkylene oxide having 2 to 4 carbon atoms such as ethylene oxide, propylene oxide, butylene oxide, and still more preferably, the main component is ethylene oxide.

The “main body” as used herein means that when the polyalkylene glycol chain is composed of two or more types of alkylene oxides, it accounts for the majority of the total number of alkylene oxides present. When “dominating” is expressed in terms of mol% of ethylene oxide in 100 mol% of all alkylene oxides, 50 to 100 mol% is preferable. Thereby, the polyalkylene glycol block copolymer of the present invention has higher hydrophilicity. More preferably, it is 60 mol% or more, More preferably, it is 70 mol% or more, Especially preferably, it is 80 mol% or more, Most preferably, it is 90 mol% or more.

When the polyalkylene glycol chain is composed of two or more kinds of alkylene oxides, two or more kinds of alkylene oxides may be added in any form such as random addition, block addition, and alternate addition.

When the polymer chain (B) by the monoalkoxy polyalkylene glycol-based structural unit contains an alkylene oxide having 3 or more carbon atoms, the polyalkylene glycol block copolymer of the present invention has a certain degree of hydrophobicity. Therefore, when the above copolymer is used as a cement admixture, a slight structure (network) is provided to the cement particles, and the viscosity and stiffness of the cement composition can be reduced. . On the other hand, if an alkylene oxide having 3 or more carbon atoms is introduced too much, the hydrophobicity of the copolymer becomes too high, and the performance of dispersing cement particles may not be sufficient. For this reason, it is preferable that content of C3 or more alkylene oxide with respect to 100 mass% of all alkylene oxides is 30 mass% or less. More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less, Most preferably, it is 5 mass% or less.
In addition, depending on the use calculated | required by the said copolymer, the aspect which does not contain C3 or more alkylene oxide may be preferable.

Here, the polymer chain (B) based on the monoalkoxypolyalkylene glycol-based structural unit and the polymer chain (A) based on the unsaturated carboxylic acid-based monomer unit are hydrolyzed depending on the structure of the binding site (X). May be cut off. When improvement in hydrolysis resistance is required, it is preferable to introduce an oxyalkylene group having 3 or more carbon atoms at the terminal of the polymer chain (B) of the monoalkoxypolyalkylene glycol-based structural unit.
Examples of the oxyalkylene group having 3 or more carbon atoms include an oxypropylene group, an oxybutylene group, an oxystyrene group, and an alkyl glycidyl ether residue. Of these, an oxypropylene group and an oxybutylene group are preferable because of ease of production.
The introduction amount of the oxyalkylene group having 3 or more carbon atoms depends on the degree of hydrolysis resistance required, but the introduction amount with respect to both ends of the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit. Is preferably 50 mol% or more. More preferably, it is 100 mol% or more, More preferably, it is 150 mol% or more, Especially preferably, it is 200 mol% or more.

In the polyalkylene glycol block copolymer according to the first aspect of the present invention, the average added mole number of the oxyalkylene group is 75 or more.
In the polyalkylene glycol block copolymer according to the second aspect of the present invention, the average number of repeating alkylene oxides in the polymer chain (B) by the monoalkoxypolyalkylene glycol structural unit (average number of moles of oxyalkylene group added) As, it is 75-500.
In the general formula (1), the average number of repeating alkylene oxides is represented by n.
In the present invention, by setting the average added mole number of the oxyalkylene group to 75 or more, the above-mentioned copolymer can sufficiently exhibit the performance based on the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit. It becomes possible.
In addition, when the average added mole number of the oxyalkylene group exceeds 500, the viscosity of the raw material compound used for producing the copolymer is increased, and the reactivity is not sufficient. There is a possibility that it may not be suitable in terms of points. The lower limit value of the average number of repetitions is more preferably 100, still more preferably 120, and still more preferably 150. As an upper limit, More preferably, it is 400, More preferably, it is 300, More preferably, it is 250, Most preferably, it is 200.
The average number of repeating alkylene oxides (average number of added moles of oxyalkylene group) is a polymer chain (B) composed of a monoalkoxypolyalkylene glycol-based structural unit of the polyalkylene glycol block copolymer of the present invention. It means the average value of the number of moles of alkylene oxide added in 1 mole.

R ¹ in the general formula (1) represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and the R ¹ —O— moiety in the general formula (1) is a monoalkoxy poly It corresponds to the “monoalkoxy” part of the polymer chain (B) with an alkylene glycol structural unit.
R ¹ is a portion corresponding to one end of the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit, and R ¹ —O— in the general formula (1) has a portion in which R ¹ has ¹ to 10 carbon atoms. In the case of the alkyl group or alkenyl group, an alcohol residue obtained by removing active hydrogen from the hydroxyl group of the alcohol. R ¹ constituting the alcohol residue may be linear, branched or cyclic.
R ¹ is preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, and more preferably a methyl group. It is a group.
In the polyalkylene glycol block copolymer according to the first aspect of the present invention, the end of the polymer chain (B) that is not bonded to the bonding site (X) is a polymer composed of a monoalkoxy polyalkylene glycol-based structural unit. It is a group corresponding to the “monoalkoxy” part of the chain (B), and is preferably an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms. Moreover, it is more preferable that it is the structure similar to the said alcohol residue.

<Binding site (X)>
As the bonding site (X) in the polyalkylene glycol block copolymer of the present invention, a polymer chain (A) comprising an unsaturated carboxylic acid monomer unit and a polymer chain comprising a monoalkoxypolyalkylene glycol constituent unit ( The structure is not particularly limited as long as it has a structure capable of chemically and stably binding to B).
As a preferable structure of the binding site (X), an organic residue derived from a structure serving as a chain transfer agent used in a polymerization reaction can be mentioned.
In the general formula (1), X represents an organic residue as the binding site (X).
Examples of binding site (X) include (i) a binding site containing a sulfur atom, (ii) a binding site derived from an azo initiator, (iii) a binding site derived from a residue containing a phosphorus atom, (iv) other Examples include structure-derived binding sites.

(I) Binding site containing a sulfur atom Examples of the binding site containing a sulfur atom include the following formula (3):

[Wherein R ⁷ represents an organic residue, preferably an aromatic group such as a linear or branched alkylene group having 1 to 18 carbon atoms, phenyl group, alkylphenyl group, pyridinyl group, thiophene, pyrrole, furan, thiazole, etc. Group or mercaptocarboxylic acid residue (which may be partially substituted with a hydroxyl group, amino group, cyano group, carbonyl group, carboxyl group, halogen group, sulfonyl group, nitro group, formyl group, etc.)] The structure shown by is mentioned.
Among the bonding sites containing the sulfur atom, in particular, the following formula (4):

[Wherein R ⁸ is a mercaptocarboxylic acid residue, preferably a linear or branched alkylene group having 1 to 18 carbon atoms, phenyl group, alkylphenyl group, pyridinyl group, thiophene, pyrrole, furan, thiazole, etc. In which the structure is partially substituted by a hydroxyl group, amino group, cyano group, carbonyl group, carboxyl group, halogen group, sulfonyl group, nitro group, formyl group, etc.] preferable.

R ⁷ of the structure represented by the above formula (3) is a site bonded to the polymer chain (B) by the monoalkoxypolyalkylene glycol type structural unit, and the sulfur atom (S) is an unsaturated carboxylic acid type monomer unit. It is a site | part couple | bonded with the polymer chain (A) by.
The structure of one end of the binding site represented by the above formula (4) (the bond on the left side of the formula (4)) is the terminal of the polymer chain (B) by the carboxyl group of mercaptocarboxylic acid and the monoalkoxypolyalkylene glycol-based structural unit. It can be obtained by causing a dehydration esterification reaction with the hydroxyl group of
Using the thiol ester obtained by the esterification reaction as a chain transfer agent, the unsaturated carboxylic acid monomer (a) can be block polymerized using a radical polymerization initiator, and as a result, the above formula (4) It becomes a binding site of the structure shown in FIG.
Examples of mercaptocarboxylic acids include mercaptoacetic acid, mercaptopropionic acid, 3-mercaptoisobutyric acid, 11-mercaptoundecanoic acid and the like. Among these, 3-mercaptoisobutyric acid and 3-mercaptopropionic acid are preferable.

(Ii) Binding site derived from an azo initiator The binding site derived from an azo initiator is a site derived from a polymerization initiator (azo initiator) containing an azo group, for example, as shown in the following formula (5) Examples include structures derived from azo initiators.

[Wherein, R ⁹ are independently of each other an alkylene group having 1 to 20 carbon atoms (the alkylene group is partially substituted with an alkyl group, an alkenyl group, a hydroxyl group, a cyano group, a carboxyl group, an amino group, etc. ), A carbonyl group or a carboxyl group, or an alkylene group having 1 to 20 carbon atoms (the alkylene group is an alkyl group, an alkenyl group, a hydroxyl group, a cyano group, a carboxyl group, an amino group, etc.). Is a group bonded to a carbonyl group or a carboxyl group, and R ¹⁰ is independently of each other an alkyl group having 1 to 20 carbon atoms, carboxy-substituted (having 1 to 10 carbon atoms). an alkyl group, a phenyl group or substituted phenyl group, R ¹¹ are, independently of one another, a cyano group, an acetoxy group, a carbamoyl group or a (carbon number 1 0 is an alkoxy) carbonyl group. An azo initiator having a repeating unit represented by
More preferably, the azo initiator shown by following formula (6) is mentioned.

The azo initiator represented by the above formula (6) preferably has a structure in which the terminal is previously bonded to the polymer chain (B) by a monoalkoxypolyalkylene glycol structural unit by an ester bond.
As a specific example, it can be obtained by esterifying 4,4′-azobis (4-cyanopentanoic acid) (an azo initiator V-501 manufactured by Wako Pure Chemical Industries) with a polyalkylene glycol monoalkyl ether such as methoxypolyethylene glycol. Mention may be made of polymeric azopolyalkylene glycol initiators. This esterification needs to be performed at a low temperature in the presence of a dehydration condensing agent such as dicyclohexylcarbodiimide.

The structure of the organic residue X as a binding site derived from the azo initiator represented by the above formulas (5) and (6) is a structure represented by the following formulas (7) and (8).

^Wherein, R ^9, R ^{10, R 11} are the same as ^{R 9,} R ^{10, R 11} in the formula (5)]

(Iii) Binding site derived from a residue containing a phosphorus atom Examples of the binding site containing a phosphorus atom include the following formula (9):

[Wherein Y represents an organic residue. M ³ represents a metal atom, an ammonium group, or an organic amine group].
Y is a site bonded to the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit, and the phosphorus atom of hypophosphorous acid (salt) bonded to Y depends on the unsaturated carboxylic acid-based monomer unit. This is the site that binds to the polymer chain (A).

Examples of the organic residue include a linear, branched or cyclic alkylene group having 2 to 30 carbon atoms, and a divalent aromatic group having 6 to 30 carbon atoms (phenylene group, alkylphenylene group, and pyridine, Thiophene, pyrrole, furan, divalent group derived from thiazole, etc.), for example, hydroxyl group, amino group, acetylamino group, cyano group, carbonyl group, carboxyl group, halogen group, sulfonyl group, nitro group, formyl A group which may be partially substituted with a substituent such as a group is preferred.
Among these, more preferably, a divalent organic residue having 2 to 18 carbon atoms and a part thereof are substituted with a hydroxyl group, and more preferably a linear or branched chain having 2 to 8 carbon atoms. -Like alkylene groups and some of them are substituted with hydroxyl groups.

The hypophosphite is preferably a salt formed by hypophosphorous acid and any one of a metal, ammonia or an organic amine. As the metal, an alkali metal, an alkaline earth metal or the like is preferable. Examples of organic amines include alkylamines having 1 to 18 carbon atoms, hydroxyalkylamines, polyalkylenepolyamines, and the like. Among these, a salt formed by sodium, potassium, ammonia, or triethanolamine is preferable.

(Iv) Binding sites derived from other structures Specific examples of the binding sites derived from other structures include the following binding sites derived from chain transfer agents. Among these, those having a sulfur atom are also included in the above (i) binding site containing a sulfur atom.
For example, after reacting a thiocarboxylic acid such as thioacetic acid and thiobenzoic acid with zinc halide on the terminal -OH group of polyalkylene glycol, alkali hydrolysis is performed to convert the -OH group to -SH. Compound converted into a group; after reacting diethyl azodicarboxylate (DEAD) with triphenylphosphine in the presence of polyalkylene glycol and thioacetic acid, alkali hydrolysis is performed to form a terminal -alkylene glycol- Compound in which OH group is converted to —SH group; Compound in which allyl halide such as allyl bromide is SN2 reacted with —OH group at the terminal of polyalkylene glycol to allylate the terminal of polyalkylene glycol; To compounds with double bonds such as allyl groups at the end, thioacetic acid, thiobenzoate After addition of thiocarboxylic acid such as an acid, by performing alkaline hydrolysis, the compound was converted to -SH group;
These compounds (chain transfer agents) may be used alone or in combination of two or more.

<Polyalkylene glycol block copolymer>
A structure in which a polymer chain (A) based on an unsaturated carboxylic acid monomer unit and a polymer chain (B) based on a monoalkoxypolyalkylene glycol structural unit are bonded via a binding site (X) is essential. Among the polyalkylene glycol block copolymers according to the first invention and the second invention, a particularly preferred structure is a structure represented by the following formula (10) or (11).

[Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms. R ³ is the same or different and represents a hydrogen atom or a methyl group. n represents the average addition mole number of an oxyethylene group, and is a number of 75-500. m is a number from 20 to 500. ]
In the above structure, the unsaturated carboxylic acid monomer is acrylic acid or methacrylic acid, the polyalkylene glycol chain is a polyethylene glycol chain, and the binding site (X) is a binding site containing a sulfur atom derived from 3-mercaptoisobutyric acid. It is a certain structure.

[Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms. R ³ is the same or different and represents a hydrogen atom or a methyl group. n represents the average addition mole number of an oxyethylene group, and is a number of 75-500. m is a number from 20 to 500. ]
In the above structure, the unsaturated carboxylic acid monomer is acrylic acid or methacrylic acid, the polyalkylene glycol chain is a polyethylene glycol chain, and the binding site (X) is a binding site containing a sulfur atom derived from 3-mercaptopropionic acid. It is a certain structure.
In the above formulas (10) and (11), the positions of R ³ and the COOH group of the unsaturated carboxylic acid monomer unit are drawn on the terminal hydrogen atom side. ³ and the position of the COOH group may be located on the sulfur atom side. In the structures represented by the above formulas (10) and (11), whether the positions of R ³ and the COOH group are on the hydrogen atom side or the sulfur atom side is randomly determined for each monomer unit.

The polyalkylene glycol block copolymer of the present invention has a weight average molecular weight (Mw) in consideration of its handleability and the retention of the cement composition when the polymer is used for cement admixture. It is preferable that it is 1 million or less. More preferably, it is 500,000 or less, More preferably, it is 300,000 or less, More preferably, it is 200,000 or less, More preferably, it is 150,000 or less, More preferably, it is 100,000 or less, More preferably, it is 50,000 or less. Further, when used for cement admixture, it is preferable that Mw is 1000 or more from the viewpoint that performance is better when adsorbed to cement particles to some extent, and the adsorption power increases as Mw increases. More preferably, it is 5000 or more, More preferably, it is 10,000 or more, Especially preferably, it is 20,000 or more, Most preferably, it is 30,000 or more.
The number average molecular weight (Mn) is preferably 500,000 or less. More preferably, it is 250,000 or less, More preferably, it is 150,000 or less, More preferably, it is 100,000 or less, More preferably, it is 75,000 or less, More preferably, it is 35,000 or less. Moreover, it is preferable that it is 1000 or more. More preferably, it is 2500 or more, More preferably, it is 5000 or more, Especially preferably, it is 10,000 or more, Most preferably, it is 15000 or more.
In addition, the weight average molecular weight and number average molecular weight of a compound can be calculated | required by the gel permeation chromatography (GPC) analysis method mentioned later.

<Method for producing polyalkylene glycol block copolymer>
As an example of the method for producing the polyalkylene glycol block copolymer according to the present invention, a case of producing a copolymer having a binding site containing a sulfur atom derived from mercaptocarboxylic acid will be described below.

The polyalkylene glycol block copolymer according to the present invention provides a polymer chain (B) with a monoalkoxy polyalkylene glycol structural unit having a hydroxyl group terminal at at least one terminal, A thiol ester is obtained by reacting the carboxyl group of mercaptocarboxylic acid to carry out an esterification reaction (esterification reaction step), and using the above thiol ester as a chain transfer agent, an unsaturated carboxylic acid system using a radical polymerization initiator It can manufacture by performing the process (block polymerization process) which block-polymerizes a monomer.
A method for producing such a polyalkylene glycol block copolymer is also one aspect of the present invention.

<Esterification reaction process>
In the esterification reaction step, an ester bond is formed by reacting the hydroxyl group terminal of the polymer chain (B) with the carboxyl group of mercaptocarboxylic acid by a monoalkoxypolyalkylene glycol structural unit having a hydroxyl group terminal at at least one terminal. Thus, a thiol ester represented by the following formula (12) is obtained.
Hereinafter, a thiol ester having the following structure is also referred to as a PAG thiol compound.

[Wherein, AO is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. R ¹ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms. R ⁸ is a mercaptocarboxylic acid residue, preferably an aromatic group such as a linear or branched alkylene group having 1 to 18 carbon atoms, phenyl group, alkylphenyl group, pyridinyl group, thiophene, pyrrole, furan or thiazole. (However, it may be partially substituted with a hydroxyl group, amino group, cyano group, carbonyl group, carboxyl group, halogen group, sulfonyl group, nitro group, formyl group, etc.)]

The PAG thiol compound has a weight average molecular weight (Mw) of 500,000 or less in consideration of its handleability and the viscosity of the cement composition when a polymer produced using the compound is used for cement admixture. It is preferable that More preferably, it is 300,000 or less, More preferably, it is 100,000 or less, Especially preferably, it is 50,000 or less, Most preferably, it is 30,000 or less. Moreover, when using for a cement admixture use, it is preferable that Mw is 100 or more from a viewpoint that the one where Mw is large to some extent becomes dispersible. More preferably, it is 300 or more, More preferably, it is 500 or more, Especially preferably, it is 1000 or more, Most preferably, it is 2000 or more.
The number average molecular weight (Mn) is preferably 500,000 or less. More preferably, it is 300,000 or less, More preferably, it is 100,000 or less, Especially preferably, it is 50,000 or less, Most preferably, it is 30,000 or less. Moreover, it is preferable that it is 100 or more. More preferably, it is 300 or more, More preferably, it is 500 or more, Especially preferably, it is 1000 or more, Most preferably, it is 2000 or more.
In addition, the weight average molecular weight and number average molecular weight of a compound can be calculated | required by the gel permeation chromatography (GPC) analysis method mentioned later.

The PAG thiol compound acts as a chain transfer agent for radical polymerization reaction due to having a mercapto group derived from mercaptocarboxylic acid, and is suitable for production of various polymers using radical polymerization reaction. Can be used.

<Block polymerization process>
As described above, the PAG thiol compound has a function as a chain transfer agent. By using this compound as a chain transfer agent, radical polymerization of an unsaturated carboxylic acid monomer component is performed in the present invention. The polyalkylene glycol block copolymer can be easily and efficiently produced at a low cost.

When a polymer is produced using the PAG thiol compound represented by the general formula (12) as a chain transfer agent, the unsaturated carboxylic acid monomer component is present via the sulfur atom (S) of the PAG thiol compound. One after another is added to form a polymer portion, and the polymer thus formed is produced as a main component.

In the polymerization reaction, a normal chain transfer agent may be used in combination. Examples of chain transfer agents that can be used include thiol chain transfer agents such as mercaptoethanol, thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, and 2-mercaptoethanesulfonic acid; secondary such as isopropyl alcohol Alcohol; phosphorous acid, hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionite, metabisulfite and salts thereof (sodium sulfite, hydrogen sulfite) And hydrophilic chain transfer agents such as lower oxides of sodium, sodium dithionite, sodium metabisulfite, and the like, and salts thereof.

A hydrophobic chain transfer agent can also be used as the chain transfer agent. Examples of the hydrophobic chain transfer agent include 3 carbon atoms such as butanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, octadecanethiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, and octyl 3-mercaptopropionate. A thiol chain transfer agent having the above hydrocarbon group is preferably used.

When the chain transfer agent is used in addition to the PAG thiol compound, the amount used may be set as appropriate, but is preferably 0.1 mol or more with respect to 100 mol of the unsaturated carboxylic acid monomer component. More preferably, it is 0.25 mol or more, more preferably 0.5 mol or more, and preferably 20 mol or less, more preferably 15 mol or less, still more preferably 10 mol or less.

In order to improve the polymerization rate of the monomer (a), it is important to appropriately set the neutralization rate of the carboxyl group of the monomer (a). In order to improve the polymerization rate of the monomer (a), it is preferable not to neutralize the carboxyl group as much as possible. However, when the neutralization rate of the carboxyl group is low, the acid-type carboxyl group and the oxygen atom of the monoalkoxypolyalkylene glycol structural unit may hydrogen bond to form a water-insoluble intermediate. The polymerization rate of the monomer (a) may decrease. Moreover, when the neutralization rate of the carboxyl group of the monomer (a) is increased too much, the polymerizability of the monomer (a) decreases, and as a result, the polymerization rate of the monomer (a) decreases. .
The neutralization rate of the carboxyl group of the monomer (a) is preferably 0 to 50 mol%, more preferably 3 to 40 mol%, still more preferably 5 to 30 mol%.

The polymerization reaction can be performed by a method such as solution polymerization or bulk polymerization using a radical polymerization initiator as necessary. The solution polymerization can be performed batchwise, continuously, or a combination thereof. Examples of the solvent used in this case include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; benzene, toluene, Aromatic or aliphatic hydrocarbons such as xylene, cyclohexane and n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane. Among them, for example, when used in an application that is often used as an aqueous solution such as a cement admixture, polymerization is preferably performed by an aqueous solution polymerization method.

Among the above solution polymerizations, in aqueous solution polymerization, it is preferable to use a water-soluble radical polymerization initiator because it is not necessary to remove insoluble components after polymerization. For example, persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; hydrogen peroxide; azoamidine compounds such as 2,2′-azobis-2-methylpropionamidine hydrochloride, 2,2′-azobis-2- Cyclic azoamidine compounds such as (2-imidazolin-2-yl) propane hydrochloride, azonitrile compounds such as 2-carbamoylazoisobutyronitrile, 2,4′-azobis {2-methyl-N- [2- (1- Water-soluble azo initiators such as azoamide compounds such as (hydroxybutyl)] propionamide}, macroazo compounds such as esters of 4,4′-azobis (4-cyanovaleric acid) and (alkoxy) polyethylene glycol, These 1 type (s) or 2 or more types can be used. Of these, azoamidine compound-based initiators are preferred.

At this time, alkali metal sulfite such as sodium hydrogen sulfite, metabisulfite, sodium hypophosphite, Fe (II) salt such as molle salt, hydroxymethanesulfinate sodium dihydrate, hydroxylamine hydrochloride, thiourea , L-ascorbic acid (salt), erythorbic acid (salt) and other accelerators (reducing agents) can be used in combination. For example, a combination of hydrogen peroxide and an organic reducing agent is possible. Examples of the organic reducing agent include L-ascorbic acid (salt), L-ascorbic acid ester, erythorbic acid (salt), erythorbic acid ester, and the like. It can be used suitably. These radical polymerization initiators and accelerators (reducing agents) may be used alone or in combination of two or more.
The amount of the accelerator (reducing agent) used is not particularly limited. For example, when the total amount of the polymerization initiator used in combination is 100 mol, it is preferably 10 mol or more, more preferably 20 mol or more. More preferably, it is 50 mol or more, preferably 1000 mol or less, more preferably 500 mol or less, still more preferably 400 mol or less.

In solution polymerization and bulk polymerization using lower alcohols, aromatic or aliphatic hydrocarbons, esters or ketones as solvents, radical polymerization initiators such as benzoyl peroxide, lauroyl peroxide, sodium peroxide, etc. Peroxides such as t-butyl hydroperoxide and cumene hydroperoxide; azonitrile compounds such as azobisisobutyronitrile, 2,4′-azobis {2-methyl-N- [2- (1- 1 or 2 of azo initiators such as azoamide compounds such as hydroxybutyl)] propionamide}, macroazo compounds such as esters of 4,4′-azobis (4-cyanovaleric acid) and (alkoxy) polyethylene glycol More than seeds can be used. Among these, an azo initiator is suitable as will be described later. In this case, an accelerator such as an amine compound can be used in combination.
Furthermore, when using a mixed solvent of water and a lower alcohol, it can be appropriately selected from the above-mentioned various radical polymerization initiators or a combination of the above radical polymerization initiator and accelerator.

The amount of the radical polymerization initiator used may be appropriately set according to the form and amount of the PAG thiol compound and the unsaturated carboxylic acid monomer component, but the unsaturated carboxylic acid that the radical polymerization initiator provides for polymerization. If the amount is too small relative to the monomer component, the radical concentration may be too low and the polymerization reaction may be slowed.On the other hand, if the amount is too large, the radical concentration will be too high, which is less than the polymerization reaction caused by sulfur atoms. The polymerization reaction from the saturated carboxylic acid monomer component has priority, and the yield of the polyalkylene glycol block copolymer of the present invention may not be increased. Therefore, the amount of the radical polymerization initiator used is preferably 0.001 mol or more, more preferably 0.01 mol or more, and still more preferably 0.001 mol or more with respect to 100 mol of the total amount of unsaturated carboxylic acid monomer components. 1 mol or more, particularly preferably 0.2 mol or more, more particularly preferably 1 mol or more, most preferably 5 mol or more, preferably 50 mol or less, more preferably 20 mol or less, still more preferably 10 mol. Hereinafter, even more preferably 5 mol or less, particularly preferably 2 mol or less, and most preferably 1 mol or less.

In the above polymerization reaction, the polymerization conditions such as the polymerization temperature are appropriately determined depending on the polymerization method used, the solvent, the polymerization initiator, and the chain transfer agent, but the polymerization temperature is preferably 0 ° C. or higher, It is preferable that it is 150 degrees C or less. More preferably, it is 30 degreeC or more, More preferably, it is 50 degreeC or more. More preferably, it is 120 degrees C or less, More preferably, it is 100 degrees C or less.

The method for charging the unsaturated carboxylic acid monomer component into the reaction vessel is not particularly limited, and a method in which the entire amount is initially charged into the reaction vessel at once; a method in which the entire amount is divided or continuously charged into the reaction vessel Any of the methods in which a part is initially charged into the reaction vessel and the remainder is divided or continuously charged into the reaction vessel may be employed. The radical polymerization initiator and the chain transfer agent may be charged into the reaction vessel from the beginning, or may be dropped into the reaction vessel, or these may be combined depending on the purpose. The system block copolymer may be produced by a method in which the whole amount of the PAG thiol compound is initially charged into a reaction vessel at an initial stage, and then an unsaturated carboxylic acid monomer component is continuously added thereto. preferable. When produced by such a method, the fluidity of the cement can be further improved when the resulting polymer is used as a cement admixture.

In the above polymerization reaction, in order to obtain a polymer having a predetermined molecular weight with good reproducibility, it is preferable to allow the polymerization reaction to proceed stably. Therefore, in the solution polymerization, the dissolved oxygen concentration at 25 ° C. of the solvent to be used is set to a range of 5 ppm or less (preferably 0.01 to 4 ppm, more preferably 0.01 to 2 ppm, still more preferably 0.01 to 1 ppm). It is preferable to do. In addition, when performing nitrogen substitution after adding an unsaturated carboxylic acid monomer component to the solvent, the dissolved oxygen concentration of the system including the unsaturated carboxylic acid monomer component is within the above range. Is appropriate.

The dissolved oxygen concentration of the solvent may be adjusted in a polymerization reaction tank, or a dissolved oxygen amount may be adjusted in advance. Examples of the method for driving off oxygen in the solvent include the following methods (1) to (5).
(1) After pressure-filling an inert gas such as nitrogen in a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. In that case, you may reduce the pressure in a sealed container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

The polymer obtained by the above polymerization reaction is easy to handle by adjusting it to a pH range of weak acid or higher (preferably pH 4 or higher, more preferably pH 5 or higher, particularly preferably pH 6 or higher) in an aqueous solution state. be able to.
On the other hand, when the polymerization reaction is carried out at a pH of 7 or more, the polymerization rate is lowered, and at the same time, the copolymerizability is not sufficient. For example, when used for cement admixture, there is a possibility that the dispersion performance cannot be sufficiently exhibited. is there. Therefore, in the polymerization reaction, it is preferable to perform the polymerization reaction in a pH range from acidic to neutral (preferably less than pH 6, more preferably less than pH 5.5, and still more preferably less than pH 5). Examples of preferable polymerization initiators that change the polymerization system from acidic to neutral include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate, and azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride. It is preferable to use a water-soluble azo initiator such as hydrogen peroxide, a combination of hydrogen peroxide and an organic reducing agent, or the like.

In addition to polyalkylene glycol block copolymer, the reaction product obtained by the above polymerization reaction may contain various polymers as by-products and unreacted raw materials, impurities contained in the raw materials, If necessary, it may be subjected to a process of isolating individual polymers, but it is usually used for various purposes without isolating individual polymers from the viewpoint of work efficiency and production cost. May be.

<Method for producing a copolymer having a binding site other than a binding site containing a sulfur atom>
Up to this point, an example in the case of producing a copolymer having a binding site containing a sulfur atom derived from mercaptocarboxylic acid has been described, but a method for producing a copolymer having another structure as the binding site will be described below. To do.

In the case of producing a copolymer having a binding site derived from an azo initiator, a structure in which the terminal of the azo initiator is preliminarily bonded to a polymer chain (B) by a monoalkoxypolyalkylene glycol-based structural unit by an ester bond as a starting material Can be used.
Those having a structure in which the terminal of the azo initiator is previously bonded to the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit by an ester bond include, for example, an azo initiator having carboxyl groups at both ends of the azo group ( It can also be obtained by esterifying V-501 or the like (made by Wako Pure Chemical Industries, Ltd.) and alkoxy polyalkylene glycol. As a method of esterification, since a azo initiator will decompose | disassemble when a heating process is performed, the manufacturing method which does not include a heating process is required. As such a production method, (1) a method in which an azo initiator is reacted with thionyl chloride to synthesize an acid chloride, and then an alkoxypolyalkylene glycol is reacted to obtain an azo initiator; (2) an azo initiator and A method of obtaining an azo initiator by dehydration condensation of alkoxypolyalkylene glycol with dicyclohexylcarbodiimide (DCC) and optionally 4-dimethylaminopyridine.

When the azo initiator is used, the azo group is decomposed by heat to generate radicals, from which polymerization starts. Therefore, the unsaturated carboxylic acid monomer is successively added to one end of the polyalkylene oxide portion comprising the oxyalkylene group to form the polyalkylene glycol block copolymer according to the present invention.

When producing a copolymer having a bonding site derived from a residue containing a phosphorus atom, an organic residue having a carbon-carbon double bond at the terminal oxygen atom of the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit. It is preferable to produce a phosphorus atom-containing polyalkylene glycol compound by adding hypophosphorous acid (salt) to compound A having a structure in which groups are bonded.

In addition, the said compound A is compoundable by a well-known method.
The compound A may be synthesized by a method in which a compound having an unsaturated group is added to the polymer chain (B) of a monoalkoxypolyalkylene glycol-based structural unit. As the form of addition, known methods such as esterification, etherification and amidation can be used. The unsaturated compound to be added may be any compound that can be added to the alkylene oxide.

In the step of subjecting compound A to hypophosphorous acid (salt) addition reaction, hypophosphorous acid (salt) is added in an amount of 0.01 to 100 mol with respect to 1 mol of unsaturated bond contained in compound A. It is preferable to add and react. From the viewpoint of increasing the reaction rate of Compound A, hypophosphorous acid (salt) is preferably 0.1 mol or more, more preferably 0.2 mol or more, and even more preferably 0 with respect to 1 mol of Compound A. .5 moles or more. From the viewpoint of reducing unreacted hypophosphorous acid (salt), hypophosphorous acid (salt) is preferably 10 mol or less, more preferably 5 mol or less, and still more preferably 1 mol of Compound A. 2 mol or less.

The step of subjecting compound A to addition reaction of hypophosphorous acid (salt) is preferably performed at a temperature of 0 to 200 ° C. More preferably, it is performed at a temperature of 20 to 150 ° C, more preferably 40 to 120 ° C, and still more preferably 50 to 100 ° C.

It is preferable to purify the resulting phosphorus atom-containing polyalkylene glycol compound after the step of subjecting compound A to addition reaction of hypophosphorous acid (salt). The purification step can be performed by drying the solution after the reaction to remove the solvent, then suspending in the purification solvent and performing filtration, and extraction, or both.
The purification solvent may be selected as appropriate, and for example, THF, acetonitrile, chloroform, isopropyl alcohol and the like are preferable.
The extraction solvent may be selected as appropriate, but it is preferably carried out using water, methanol, acetonitrile, dioxane or the like as the highly polar solvent. It is preferable to use diethyl ether, cyclohexane, chloroform, methylene chloride or the like as the low polarity solvent.

The step of subjecting compound A to hypophosphorous acid (salt) to an addition reaction can be performed in a solution state in which a radical polymerization initiator is used as necessary and dissolved in a solvent. Examples of the solvent used in this case include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, and n-hexane; ethyl acetate and the like. Ester compounds; ketone compounds such as acetone and methyl ethyl ketone; and cyclic ether compounds such as tetrahydrofuran and dioxane. Among these, it is preferable to use water as a solvent.

When performing the addition reaction of the compound A and hypophosphorous acid (salt) using water as a solvent, it is necessary to use a water-soluble radical polymerization initiator to remove insoluble components after the reaction. It is preferable because there is no. For example, persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; hydrogen peroxide; organic peroxides such as t-butyl hydroperoxide; 2,2′-azobis-2-methylpropionamidine hydrochloride, etc. Azoamidine compounds, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, azonitrile compounds such as 2-carbamoylazoisobutyronitrile, 2,4′-azobis { Azoamide compounds such as 2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, macroazo compounds such as esters of 4,4′-azobis (4-cyanovaleric acid) and (alkoxy) polyethylene glycol Water-soluble azo initiators such as these can be used, and one or more of these can be used. Among these, a persulfuric acid-based initiator is preferable.

The phosphorus atom-containing polyalkylene glycol-based compound has a function as a chain transfer agent, and radical polymerization of an unsaturated carboxylic acid monomer using the compound as a chain transfer agent allows the use of the present invention. A polyalkylene glycol block copolymer can be produced simply and efficiently at a low cost.
Since the step of radically polymerizing the unsaturated carboxylic acid monomer can be performed in the same manner as the block polymerization step using the PAG thiol compound as a chain transfer agent, detailed description thereof is omitted.

The polyalkylene glycol block copolymer of the present invention can be suitably used for various applications such as an adhesive, a sealing agent, a component for imparting flexibility to various polymers, and a detergent builder. In a composition containing inorganic fine particles such as gypsum, it can also be suitably used as a dispersant for dispersing inorganic fine particles.
A dispersant containing such a polyalkylene glycol block copolymer of the present invention is also one aspect of the present invention.
Among these, the polyalkylene glycol block copolymer of the present invention is suitable for use as a cement admixture because it can exhibit extremely high cement dispersion performance as described above. Thus, the cement admixture containing the polyalkylene glycol block copolymer is also one aspect of the present invention.
The cement admixture can be used in addition to a cement composition such as cement paste, mortar, concrete, etc., and such a cement composition containing the cement admixture is also one aspect of the present invention.

As the above-mentioned cement composition, those containing cement, water, fine aggregate, coarse aggregate and the like are suitable. As the cement, Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate resistance, Various mixed cements (blast furnace cement, silica cement, fly ash cement); white Portland cement; alumina cement; super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement) ); Grout cement; oil well cement; low exothermic cement (low exothermic blast furnace cement, fly ash mixed low exothermic blast furnace cement, high content of belite); ultra high strength cement; cement-based solidified material; ecocement (city waste) Cement produced from one or more of incineration ash and sewage sludge incineration ash G) other such, these blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, and a film obtained by adding a fine powder and gypsum limestone powder.
As the above aggregate, in addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia, etc. Refractory aggregate and the like.

Examples of the unit water amount per 1 m ³ of the cement composition, the cement use amount, and the water / cement ratio (mass ratio) include, for example, a unit water amount of 100 to 185 kg / m ³ , a use cement amount of 200 to 800 kg / m ³ , and a water / cement ratio. The cement ratio (mass ratio) is preferably 0.1 to 0.7, and more preferably, the unit water amount is 120 to 175 kg / m ³ , the cement amount used is 250 to 800 kg / m ³ , and the water / cement ratio ( (Mass ratio) = 0.2 to 0.65. Thus, the cement admixture containing the polyalkylene glycol block copolymer of the present invention can be used in a wide range from poor blending to rich blending, and has a high water reduction rate region, that is, a water / cement ratio. (Mass ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4) can be used even in a low water / cement ratio region, and the unit cement amount is large and the water / cement ratio is small. It is effective for both high-strength concrete and poor-mixed concrete having a unit cement amount of 300 kg / m ³ or less.

As the cement admixture of the present invention, the fluidity, retention and workability can be exhibited with high performance in a balanced manner even in a high water reduction rate region, and since it has excellent workability, ready-mixed concrete, concrete secondary products ( It can be used effectively for precast concrete), centrifugal concrete, vibration compaction concrete, steam-cured concrete, shotcrete, etc., and medium fluidity concrete (slump value is 22-25cm) Mortar and concrete that require high fluidity, such as concrete with high fluidity (concrete with a slump value of 25 cm or more and a slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material, etc. Also effective.

When the above cement admixture is used in a cement composition, the blending ratio is such that the polyalkylene glycol block copolymer, which is an essential component of the present invention, is 100% by mass of the total mass of cement in terms of solid content. Therefore, it is preferable to set it to be 0.01 to 10% by mass. If it is less than 0.01% by mass, the performance may not be sufficient. On the other hand, if it exceeds 10% by mass, the effect will substantially reach its peak, which may be disadvantageous in terms of economy. More preferably, it is 0.02-8 mass%, More preferably, it is 0.05-6 mass%.

The cement admixture can also be used in combination with other cement additives. As another cement additive, 1 type (s) or 2 or more types, such as a cement additive (material) as shown below, can be used, for example. Among these, it is particularly preferable to use an oxyalkylene antifoaming agent or an AE agent in combination.
In addition, it is suitable for the addition ratio of a cement additive to be 0.0001-10 mass parts with respect to 100 mass parts of solid content of the said polyalkylene glycol type block copolymer.

(1) Water-soluble polymer substances: polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), unsaturated carboxylic acid polymer such as sodium salt of acrylic acid / maleic acid copolymer; polyethylene Polymers of polyoxyethylene or polyoxypropylene such as glycol and polypropylene glycol or copolymers thereof; Nonionic cellulose ethers such as methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxypropylcellulose, etc. Yeast glucan, xanthan gum, β-1,3 glucans (both linear and branched), for example, curdlan, paramylon, pachyman, Polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; copolymer of acrylic acid having an amino group in the molecule and its four Grade compounds and the like.

(2) Polymer emulsion.
(3) Retardant: Gluconic acid, malic acid or citric acid, and oxycarboxylic acids such as inorganic salts or organic salts such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine, and salts thereof; glucose , Fructose, galactose, saccharose; sugar alcohols such as sorbitol; magnesium silicate; phosphoric acid and its salts or borate esters; aminocarboxylic acid and its salts; alkali-soluble protein; humic acid; tannic acid; Polyhydric alcohols such as aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and alkali metal salts thereof, al Phosphonic acids and derivatives thereof such as Li earth metal salts.

(4) Early strengthening agent / accelerator: soluble calcium salt such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, calcium iodide; alkanolamine; alumina cement; calcium aluminate silicate.
(5) Mineral oil-based antifoaming agent: cocoon oil, liquid paraffin, etc.
(6) Fat and oil-based antifoaming agents: animal and vegetable oils, sesame oil, castor oil, alkylene oxide adducts thereof and the like.
(7) Fatty acid-based antifoaming agent: oleic acid, stearic acid, and these alkylene oxide adducts.
(8) Fatty acid ester antifoaming agent: glycerin monoricinoleate, alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, natural wax and the like.

(9) Oxyalkylene antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene (Poly) oxyalkyl ethers such as 2-ethylhexyl ether and higher alcohols having 12 to 14 carbon atoms such as oxyethyleneoxypropylene adducts; (poly) oxy such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether Alkylene (alkyl) aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1 -Bu Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol such as n-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; polyoxyethylene (Poly) oxyalkylene sorbitan fatty acid esters such as sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) oxyalkylene alkyl such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecylphenol ether sulfate ( Aryl) ether sulfate esters; (poly) oxyethylene stearyl phosphates, etc. Polyoxyalkylene alkyl phosphoric acid esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; polyoxyalkylene amide.

(10) Alcohol-based antifoaming agent: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.
(11) Amide antifoaming agent: acrylate polyamine and the like.
(12) Phosphate ester antifoaming agent: tributyl phosphate, sodium octyl phosphate, etc.
(13) Metal soap type antifoaming agent: aluminum stearate, calcium oleate, etc.
(14) Silicone antifoaming agent: dimethyl silicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like.
(15) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkyl benzene sulfonic acid), LAS (linear alkyl benzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether , Polyoxyethylene alkyl (phenyl) ether sulfate or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate or a salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate, and the like.

(16) Other surfactants: aliphatic monohydric alcohols having 6 to 30 carbon atoms in the molecule such as octadecyl alcohol and stearyl alcohol, and those having 6 to 30 carbon atoms in the molecule such as abiethyl alcohol Intramolecular such as alicyclic monohydric alcohol, dodecyl mercaptan, etc. Intramolecular such as monovalent mercaptan having 6-30 carbon atoms in the molecule, such as nonylphenol, alkylphenol having 6-30 carbon atoms in the molecule, dodecylamine, etc. 10 mol or more of an alkylene oxide such as ethylene oxide or propylene oxide was added to a carboxylic acid having 6 to 30 carbon atoms in the molecule such as an amine having 6 to 30 carbon atoms, lauric acid or stearic acid. Polyalkylene oxide derivatives; having an alkyl group or alkoxyl group as a substituent Alkyl diphenyl ether sulfonates in which two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride; various nonions Surfactants; various amphoteric surfactants.
(17) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicon, paraffin, asphalt, wax and the like.
(18) Rust preventive: nitrite, phosphate, zinc oxide and the like.
(19) Crack reducing agent: polyoxyalkyl ethers; alkanediols such as 2-methyl-2,4-pentanediol.
(20) Expansion material: Ettlingite, coal, etc.

Other cement additives (materials) include, for example, cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancing agents, self-leveling agents, rust preventives, colorants, antifungal agents , Blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, gypsum and the like.

<Third invention>
The polyalkylene glycol block copolymer according to the third aspect of the present invention comprises a polymer chain (A) comprising an unsaturated carboxylic acid monomer unit and a polymer chain (B) comprising a monoalkoxypolyalkylene glycol constituent unit. And a polyalkylene glycol block copolymer which essentially has a structure in which they are bonded via the binding site (X),
The polyalkylene glycol block copolymer is
The average number of moles of unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the average number of oxyalkylene groups of the polyalkylene glycol constituent units in the polymer chain (B) The added mole number is 120 or more.

Hereinafter, among the technical features of the polyalkylene glycol block copolymer according to the third invention, the technology possessed by the polyalkylene glycol block copolymer according to the first invention and the second invention described above. Differences from the characteristic features will be described.

In the polyalkylene glycol block copolymer according to the third aspect of the present invention, the structures at both ends of the copolymer (corresponding to R ¹ and R ² in the general formula (1) according to the second aspect of the present invention) are particularly limited. It is not intended to have any structure. Similarly to R ¹ in the general formula (1), the terminal on the polymer chain (B) side of the monoalkoxypolyalkylene glycol structural unit is an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms. May be. Further, similarly to R ² in the general formula (1), the terminal on the polymer chain (A) side by the unsaturated carboxylic acid monomer unit is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or 1 to 1 carbon atoms. It may be 10 alkenyl groups.

In the polyalkylene glycol block copolymer according to the third aspect of the present invention, the structure of the unsaturated carboxylic acid monomer constituting the unsaturated carboxylic acid monomer unit is derived from the monomer (a). However, the present invention is not limited thereto, and structural units derived from other monomers may be modified.

In the polyalkylene glycol block copolymer according to the third aspect of the present invention, the average number of alkylene oxide repeats (average number of moles of oxyalkylene group added) in the polymer chain (B) of the monoalkoxy polyalkylene glycol type structural unit As 120 or more.
When the average number of added moles of the oxyalkylene group is 120 or more, the above-mentioned copolymer can more fully exhibit the performance based on the polymer chain (B) by the monoalkoxypolyalkylene glycol-based structural unit. More preferably, it is 130 or more, More preferably, it is 150 or more, More preferably, it is 170 or more.
The upper limit of the average number of moles added of the oxyalkylene group is not particularly limited, but is preferably 500, more preferably 400, still more preferably 300, still more preferably 250, More preferably, it is 200.

The method for producing the polyalkylene glycol block copolymer according to the third aspect of the present invention may be the same as the method for producing the polyalkylene glycol block copolymer according to the first aspect of the present invention and the second aspect of the present invention. it can. When producing the polyalkylene glycol block copolymer according to the third aspect of the present invention, the average number of repeating alkylene oxides is 120 or more as the polymer chain (B) of the monoalkoxy polyalkylene glycol structural unit. Is used.

The polyalkylene glycol block copolymer according to the first aspect of the present invention has the above-described configuration, and is composed of a polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and a high chain composed of a monoalkoxy polyalkylene glycol based unit. A polyalkylene glycol block copolymer having a structure in which a molecular chain (B) is bonded via a bonding site (X),
The polyalkylene glycol block copolymer is
The polymer chain (A) and the polymer chain (B) have a structure in which the polymer chain (A) and the polymer chain (B) are bonded in this order via the binding site (X),
The average number of moles of the unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the terminal of the polymer chain (A) not bonded to the binding site (X) is hydrogen. , An alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and the average added mole number of the oxyalkylene group of the polyalkylene glycol structural unit in the polymer chain (B) is 75 or more. It is characterized by.
In addition, the polyalkylene glycol block copolymer of the second invention has the above-described configuration, and includes a polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and a monoalkoxypolyalkylene glycol block unit. Is a polyalkylene glycol block copolymer having a structure in which the polymer chain (B) is bonded to the polymer chain (X) via a bonding site (X), and a hydrogen atom, carbon at the terminal on the polymer chain (A) side. It has an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, an average addition mole number of an oxyalkylene group is 75 to 500, and an average introduction mole number of unsaturated carboxylic acid monomer units. It is characterized by being 20-500.
In addition, the polyalkylene glycol block copolymer of the third aspect of the present invention has the above-described configuration, and includes a polymer chain (A) composed of an unsaturated carboxylic acid monomer unit and a monoalkoxypolyalkylene glycol block unit. A polyalkylene glycol block copolymer having a structure in which the polymer chain (B) is bonded to the polymer chain (B) via the binding site (X), and the unsaturated carboxylic acid monomer in the polymer chain (A) The average number of moles of introduced body units is 20 or more, and the average number of added moles of oxyalkylene groups of the polyalkylene glycol structural unit in the polymer chain (B) is 120 or more.
Any of the polyalkylene glycol block copolymers is a polymer used for cement admixture having excellent properties such as cement dispersibility (water reduction) and slump flow.
In addition, any polyalkylene glycol block copolymer can be suitably used as a dispersant for dispersing inorganic fine particles.

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”.

Various measurements in the examples were performed as follows.
<Measurement of consumption rate of polyethylene glycol by LC>
Device: Waters Alliance (2695)
Analysis software: Waters Empower Professional + GPC option column: Waters Atlantis dC18 guard column + column (particle size 5 μm, inner diameter 4.6 mm × 250 mm × 2)
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: A mixture of acetonitrile / 100 mM acetate ion exchange aqueous solution = 40/60 (mass%) adjusted to pH 4.0 by adding 30% NaOH aqueous solution Flow rate: 1.0 mL / min Column temperature: 40 ° C.
Sample solution injection amount: 100 μL (eluent solution having a sample concentration of 1 to 2% by mass)

<Measurement of PAG thiol compound by GPC>
The monomer amount and multimer amount of the PAG thiol compound were measured under the following measurement conditions.
Device: Waters Alliance (2695)
Analysis software: Waters, Empor professional + GPC option column: Tosoh Co., Ltd., TSKguardcolumnsSWXL + TSKgel
G4000SWXL + G3000SWXL + G2000SWXL
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: A solution prepared by dissolving 115.6 g of sodium acetate trihydrate in a mixed solvent of 10999 g of water and 6001 g of acetonitrile, and further adjusting the pH to 6.0 with acetic acid. Standard material for preparing a calibration curve: polyethylene glycol (peak top molecular weight (Mp ) 272500, 219300, 107000, 50000, 24000, 12600, 7100, 4250, 1470)
Calibration curve: Flow rate prepared by cubic equation based on Mp value of polyethylene glycol and elution time: 1 mL / min Column temperature: 40 ° C
Measurement time: 45 minutes Sample solution injection amount: 100 μL (PAG, PAG thiol compound is an eluent solution having a sample concentration of 0.4 mass%)

<Measurement of polymer by GPC>
The weight average molecular weight, number average molecular weight, and peak top molecular weight of the polymer were measured under the following measurement conditions.
Device: Waters Alliance (2695)
Analysis software: Waters, Empor professional + GPC option column: Tosoh Corporation, TSKgel guardcolumn α + TSKgel α-5000 + TSKgel α-4000 + TSKgel α-3000
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: A solution prepared by dissolving 74.2 g of boric acid and 80.0 g of 30% aqueous NaOH in a mixed solvent of 11846 g of water and 3000 g of acetonitrile. Calibration standard: Polyethylene glycol (peak top molecular weight (Mp) 272500, 219300, 107,000, 50000, 24000, 12600, 7100, 4250, 1470)
Calibration curve: Flow rate prepared by cubic equation based on Mp value of polyethylene glycol and elution time: 1 mL / min Column temperature: 40 ° C
Measurement time: 75 minutes Sample solution injection amount: 100 μL (the polymer is an eluent solution having a sample concentration of 0.5% by mass)

(GPC analysis conditions)
In the obtained RI chromatogram, the portions that were flat and stable in the baseline immediately before and after elution of the polymer were connected by straight lines, and the polymer was detected and analyzed. However, when the peak of monomer or monomer-derived impurities is measured partially overlapping with the polymer peak, the polymer part and the monomer part are separated by vertical division at the most concave part of the overlapping part between them and the molecular weight of the polymer part only -The molecular weight distribution was measured. When the polymer part and the other part completely overlapped and could not be separated, the calculation was made collectively.
Further, as a measure of the yield of the polymer, the “polymer purity (hereinafter sometimes abbreviated as“ P% ”)” was calculated from the ratio of the peak area measured by the RI detector as follows.
Polymer purity = (Polymer peak area) / (Polymer peak area + monomer or impurity peak area)

<Solid content measurement conditions>
About 0.5 g of the sample was weighed on an aluminum dish and diluted with about 1 g of water to spread it uniformly. After drying at 130 ° C. for 1 hour under a nitrogen atmosphere and allowing to cool in a desiccator, the weight was measured after drying. The solid content (nonvolatile content) concentration was calculated from the weight difference before and after drying.
As the concentration of the synthesized PAG thiol compound or the aqueous solution of the polymer, the solid content measured by the above procedure was used unless otherwise specified.

<Production Example 1: Production of PAG thiol compound (1)>
(1) Dehydration esterification reaction process In a glass reactor equipped with a Dean-Stark device with a Dimroth condenser, a Teflon (R) stirring blade and a stirring seal, and a temperature sensor with a glass protective tube, Methoxypolyethylene glycol (PGM-75, manufactured by Nippon Shokubai Co., Ltd., 1000 g), 3-mercaptoisobutyric acid (MiBA, manufactured by Tokyo Chemical Industry Co., Ltd., 39.67 g), p-toluenesulfonic acid Hydrate (PTS · 1H ₂ O, manufactured by Wako Pure Chemical Industries, Ltd., 20.79 g), phenothiazine (PTZ, manufactured by Wako Pure Chemical Industries, Ltd., 0.5198 g), cyclohexane (CyH, 51.98 g) Was charged. After the Dean-Stark apparatus was filled with cyclohexane, the reaction system was heated to reflux while stirring. The temperature of the heating oil bath was 120 ± 5 ° C. Cyclohexane was added on the way so that the temperature in the reaction system became 110 ± 5 ° C., and the reaction was carried out by heating under reflux while distilling off water for 65.0 hours.

(2) Desolvation step After completion of the reaction, the mixture was allowed to cool to 60 ° C. with stirring so as not to solidify, and then an aqueous solution in which water (995.19 g) was added to 30% NaOH aqueous solution (13.85 g) was quickly reacted. It was put into the vessel. Subsequently, the temperature was gradually raised to about 100 ° C., and cyclohexane was distilled off. The heating was stopped and nitrogen was bubbled at 30 mL / min for 90 minutes while cooling to remove residual cyclohexane to obtain an aqueous solution of PAG thiol compound (1).
As a result of LC analysis of the obtained target compound, the consumption rate of methoxypolyethylene glycol (PGM-75) was 92.0%, and the average number of SH introduced per molecule of methoxypolyethylene glycol (PGM-75) was 0.92. . From this, the molecular weight was set to 3426. From the GPC analysis results, the monomer amount was 92.32%, and the remainder was a multimer.

<Production Example 2: Production of PAG thiol compound (2)>
(1) Dehydration esterification reaction process In a glass reactor equipped with a Dean-Stark device with a Dimroth condenser, a Teflon (R) stirring blade and a stirring seal, and a temperature sensor with a glass protective tube, Methoxypolyethylene glycol having an average addition mole number of ethylene oxide of 120 (PGM-120, manufactured by Nippon Shokubai Co., Ltd., 1000 g), 3-mercaptoisobutyric acid (MiBA, manufactured by Tokyo Chemical Industry Co., Ltd., 24.89 g), p-toluenesulfonic acid Hydrate (PTS · 1H ₂ O, manufactured by Wako Pure Chemical Industries, Ltd., 20.50 g), phenothiazine (PTZ, manufactured by Wako Pure Chemical Industries, Ltd., 0.5124 g), cyclohexane (CyH, 51.24 g) Was charged. After the Dean-Stark apparatus was filled with cyclohexane, the reaction system was heated to reflux while stirring. The temperature of the heating oil bath was 120 ± 5 ° C. Cyclohexane was added in the middle so that the temperature in the reaction system became 110 ± 5 ° C., and the reaction was carried out by heating and refluxing for 90.0 hours while distilling off water.

(2) Desolvation step After completion of the reaction, the mixture was allowed to cool to 60 ° C. with stirring so as not to solidify, and then quickly reacted with an aqueous solution in which water (984.26 g) was added to 30% NaOH aqueous solution (13.65 g). It was put into the vessel. Subsequently, the temperature was gradually raised to about 100 ° C., and cyclohexane was distilled off. Heating was stopped and nitrogen was bubbled at 30 mL / min for 90 minutes while cooling to remove residual cyclohexane to obtain an aqueous solution of PAG thiol compound (2).
As a result of LC analysis of the obtained target compound, the consumption rate of methoxypolyethylene glycol (PGM-120) was 98.0%, and the average number of SH introduced per molecule of methoxypolyethylene glycol (PGM-120) was 0.98. . From this, the molecular weight was set to 5412. The GPC analysis result showed that the monomer amount was 91.50%, and the remainder was a multimer.

<Production Example 3: Production of PAG thiol compound (3)>
(1) Dehydration esterification reaction process In a glass reactor equipped with a Dean-Stark device with a Dimroth condenser, a Teflon (R) stirring blade and a stirring seal, and a temperature sensor with a glass protective tube, Methoxypolyethylene glycol having an average addition mole number of ethylene oxide of 25 (PGM-25, manufactured by Nippon Shokubai Co., Ltd., 1000 g), 3-mercaptoisobutyric acid (MiBA, manufactured by Tokyo Chemical Industry Co., Ltd., 116.78 g), p-toluenesulfonic acid Hydrate (PTS · 1H ₂ O, Wako Pure Chemical Industries, Ltd., 22.34 g), phenothiazine (PTZ, Wako Pure Chemical Industries, Ltd., 0.5584 g), cyclohexane (CyH, 55.84 g) Was charged. After the Dean-Stark apparatus was filled with cyclohexane, the reaction system was heated to reflux while stirring. The temperature of the heating oil bath was 120 ± 5 ° C. Cyclohexane was added on the way so that the temperature in the reaction system became 110 ± 5 ° C., and the reaction was carried out by heating and refluxing for 47.0 hours while distilling off water.

(2) Desolvation step After completion of the reaction, the mixture was allowed to cool to 60 ° C. with stirring so as not to solidify, and then an aqueous solution in which water (1052.14 g) was added to 30% NaOH aqueous solution (14.88 g) was reacted rapidly. It was put into the vessel. Subsequently, the temperature was gradually raised to about 100 ° C., and cyclohexane was distilled off. The heating was stopped and nitrogen was bubbled at 30 mL / min for 90 minutes while cooling to remove residual cyclohexane to obtain an aqueous solution of PAG thiol compound (3).
As a result of LC analysis of the obtained target compound, the consumption rate of methoxypolyethylene glycol (PGM-25) was 98.00%, and the average number of SH introduced per molecule of methoxypolyethylene glycol (PGM-25) was 0.98. . From this, the molecular weight was set to 1232. The GPC analysis result showed that the monomer amount was 97.04%, and the remainder was a multimer.

<Example 1: Production of polymer (1)>
As a monomer solution (A), ion exchange water was added to methacrylic acid (MAA, 25.04 g) and a 30% aqueous sodium hydroxide solution (1.05 g) to make a total of 32.35 g.
PAG thiol compound (1) obtained in Production Example 1 (24.96 g, but in terms of solid content) and ion-exchanged water were added to prepare a PAG thiol compound aqueous solution totaling 83.20 g.
As an initiator solution, a solution was prepared by adding ion-exchanged water to 2,2′-azobis-2-methylpropionamidine hydrochloride (V-50, 0.24 g, manufactured by Wako Pure Chemical Industries, Ltd.) to make a total of 50 g. .
A glass reactor equipped with a Dimroth condenser, a Teflon (R) stirrer and a stirrer with a stirring seal, a nitrogen inlet tube, and a temperature sensor was charged with 68.57 g of ion-exchanged water. While introducing at 200 mL / min, the mixture was heated to 80 ° C.
Subsequently, the monomer solution (A) and the PAG thiol compound aqueous solution were dropped into the reaction vessel over 3 hours and the initiator solution over 3.5 hours. The polymerization reaction was completed by maintaining at 80 ° C. for 1 hour after completion of the dropping. After cooling to room temperature, an aqueous solution of polymer (1) was obtained.
As a result of GPC analysis, the polymer was Mw = 24600, Mp = 23200, and Mn = 18900. The pure polymer content was 92.63%.
The average addition mole number (n) of the oxyalkylene group of the polymer (1) was 75, and the average introduction mole number (m) of the unsaturated carboxylic acid monomer unit was 40.

<Example 2: Production of polymer (2)>
As monomer solution (A), ion exchange water was added to methacrylic acid (MAA, 25.02 g) and 30% aqueous sodium hydroxide solution (1.05 g) to make a total of 32.33 g.
PAG thiol compound (2) obtained in Production Example 2 (25.23 g, but in terms of solid content) and ion-exchanged water were added to prepare a PAG thiol compound aqueous solution totaling 85.63 g.
As an initiator solution, a solution was prepared by adding ion-exchanged water to 2,2′-azobis-2-methylpropionamidine hydrochloride (V-50, 0.24 g, manufactured by Wako Pure Chemical Industries, Ltd.) to make a total of 50 g. .
A glass reactor equipped with a Dimroth condenser, a Teflon (R) stirrer and a stirrer with a stirring seal, a nitrogen inlet tube, and a temperature sensor was charged with 68.57 g of ion-exchanged water. While introducing at 200 mL / min, the mixture was heated to 80 ° C.
Subsequently, the monomer solution (A) and the PAG thiol compound aqueous solution were dropped into the reaction vessel over 3 hours and the initiator solution over 3.5 hours. The polymerization reaction was completed by maintaining at 80 ° C. for 1 hour after completion of the dropping. After cooling to room temperature, an aqueous solution of the polymer (2) was obtained.
As a result of GPC analysis, the polymer was Mw = 29200, Mp = 24500, and Mn = 22600. The pure polymer content was 93.21%.
The average addition mole number (n) of the oxyalkylene group of the polymer (2) was 120, and the average introduction mole number (m) of the unsaturated carboxylic acid monomer unit was 62.

<Comparative Example 1: Production of comparative polymer (1)>
As monomer solution (A), ion exchange water was added to methacrylic acid (MAA, 25.01 g) and 30% aqueous sodium hydroxide solution (1.05 g) to make a total of 32.31 g.
PAG thiol compound (3) obtained in Production Example 3 (23.54 g, in terms of solid content) and ion-exchanged water were added to prepare a PAG thiol compound aqueous solution totaling 79.87 g.
As an initiator solution, a solution was prepared by adding ion-exchanged water to 2,2′-azobis-2-methylpropionamidine hydrochloride (V-50, 0.24 g, manufactured by Wako Pure Chemical Industries, Ltd.) to make a total of 50 g. .
A glass reactor equipped with a Dimroth condenser, a Teflon (R) stirrer and a stirrer with a stirring seal, a nitrogen inlet tube, and a temperature sensor was charged with 68.57 g of ion-exchanged water. While introducing at 200 mL / min, the mixture was heated to 80 ° C.
Subsequently, the monomer solution (A) and the PAG thiol compound aqueous solution were dropped into the reaction vessel over 3 hours and the initiator solution over 3.5 hours. The polymerization reaction was completed by maintaining at 80 ° C. for 1 hour after completion of the dropping. After cooling to room temperature, an aqueous solution of comparative polymer (1) was obtained.
As a result of GPC analysis, the polymer was Mw = 15200, Mp = 13300, and Mn = 1300. The pure polymer content was 90.03%.
The average addition mole number (n) of the oxyalkylene group of the comparative polymer (1) was 25, and the average introduction mole number (m) of the unsaturated carboxylic acid monomer unit was 15.

<Concrete test>
Using the polymers produced in Examples 1 and 2 and Comparative Example 1 as a cement admixture, the concrete slump flow value and the amount of air were measured as follows.

(1) Used material cement: Ordinary Portland cement made by Taiheiyo Cement Co., Ltd. Coarse aggregate: Ome crushed fine aggregate: Oigawa river sand (specific gravity 2.59) / Chiba prefecture Kimitsu mountain sand (specific gravity 2.53) weight ratio 9: (2) Unit amount (kg / m ³ )
W / C = 53.1
s / a = 47.0
Air = 45.0
Water = 170.0
Cement = 320
Stone = 942
Sand = 865
(3) Mixer used: Taiheiyo Kiko, TM55 (55 liter forced kneading bread type mixer), kneading amount 30 liters (4) Test method MA202 (Pozoris product) was used as an AE agent and MA404 (Pozoris product) was used as an antifoaming agent. . Fine aggregate and cement are put into a mixer and kneaded for 10 seconds. Next, cement admixture, AE agent, water containing antifoaming agent, and coarse aggregate are put in. After kneading for 60 seconds, concrete is mixed. Was discharged.
The slump flow value and the amount of air of the obtained concrete were measured in accordance with Japanese Industrial Standards (JIS A1101-2005, A1128-2005, A6204-2006). In addition, it shows that the fluidity | liquidity of concrete is so high that a slump flow value is large. If the slump flow value is the same, an admixture with a smaller addition amount indicates better cement dispersion performance and higher water reduction performance.

The results of the concrete test are shown in Table 1.
The blending amounts of the cement admixture, the defoaming agent (MA404) and the AE agent (MA202) were calculated as solid contents and are shown in Table 1 in terms of% (mass%) with respect to the cement mass.

In Comparative Example 1 in which the average number of added moles (n) of oxyalkylene groups of the copolymer and the average number of introduced moles (m) of unsaturated carboxylic acid monomer units were small, the slump flow value was small.
On the other hand, in Examples 1 and 2 in which the copolymer of the present invention having a large average addition mole number (n) of oxyalkylene groups and a large average introduction mole number (m) of unsaturated carboxylic acid monomer units was added, the slump flow The value was getting bigger.
From the above, it has become clear that the copolymer of the present invention is a polymer that can be suitably used as a cement admixture.

Claims (12)

A structure in which a polymer chain (A) based on an unsaturated carboxylic acid monomer unit and a polymer chain (B) based on a monoalkoxypolyalkylene glycol structural unit are bonded via a binding site (X) is essential. A polyalkylene glycol block copolymer,
The polyalkylene glycol block copolymer is
The polymer chain (A) and the polymer chain (B) have a structure in which the polymer chain (A) and the polymer chain (B) are bonded in this order via the binding site (X),
The average number of moles of the unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the terminal of the polymer chain (A) not bonded to the binding site (X) is hydrogen. , An alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms, and the average added mole number of the oxyalkylene group of the polyalkylene glycol structural unit in the polymer chain (B) is 75 or more. A polyalkylene glycol block copolymer. A structure in which a polymer chain (A) based on an unsaturated carboxylic acid monomer unit and a polymer chain (B) based on a monoalkoxypolyalkylene glycol structural unit are bonded via a binding site (X) is essential. A polyalkylene glycol block copolymer,
The polyalkylene glycol block copolymer is
The following general formula (1):

(In the formula, X represents an organic residue. AO is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. R ¹ is an alkyl group having 1 to 10 carbon atoms or 1 to 1 carbon atoms. R ² represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 1 to 10 carbon atoms, wherein at least one of R ³ , R ⁴ , R ⁵ , and R ⁶ is -COOM ¹ and R ³ , R ⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,-(CH ₂ ) zCOOM ² (-(CH ₂ ) zCOOM ² represents COOM ¹ or other — (CH ₂ ) zCOOM ² and may form an anhydride), and z represents an integer of 0 to 2. n is the average number of moles of oxyalkylene group added. Represents a number from 75 to 500. m is from 20 to 20. And M ¹ and M ² are the same or different and each represents a hydrogen atom, a monovalent metal, a divalent metal, a trivalent metal, a quaternary ammonium group, or an organic amine group.
A polyalkylene glycol block copolymer having a structure represented by the formula: The polyalkylene glycol block copolymer according to claim 1 or 2, wherein the bonding site (X) has a sulfur atom in the polyalkylene glycol block copolymer. 4. The polyalkylene glycol according to claim 1, wherein the polyalkylene glycol block copolymer has an average addition mole number of the oxyalkylene group of the polymer chain (B) of 120 or more. Glycol block copolymer. A dispersant comprising the polyalkylene glycol block copolymer according to claim 1. A cement admixture comprising the polyalkylene glycol block copolymer according to any one of claims 1 to 4. A cement composition comprising the cement admixture according to claim 6, cement and water. A structure in which a polymer chain (A) based on an unsaturated carboxylic acid monomer unit and a polymer chain (B) based on a monoalkoxypolyalkylene glycol structural unit are bonded via a binding site (X) is essential. A polyalkylene glycol block copolymer,
The polyalkylene glycol block copolymer is
The average number of moles of unsaturated carboxylic acid monomer units introduced into the polymer chain (A) is 20 or more, and the average number of oxyalkylene groups of the polyalkylene glycol constituent units in the polymer chain (B) A polyalkylene glycol block copolymer having an addition mole number of 120 or more. The polyalkylene glycol block copolymer according to claim 8, wherein the bonding site (X) has a sulfur atom. A dispersant comprising the polyalkylene glycol block copolymer according to claim 8 or 9. A cement admixture comprising the polyalkylene glycol block copolymer according to claim 8 or 9. A cement composition comprising the cement admixture according to claim 11, cement and water.