JP2016069412A - (poly)anionic comb-type polymer and applications thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel (poly)anionic comb-type polymer that can easily have a structure corresponding to required performances and is excellent in dispersion performance, to provide a production method for easily and efficiently producing the polymer and to provide a cement admixture, an inorganic particle additive and a cement composition each including the polymer.SOLUTION: The (poly)anionic comb-type polymer has a stem part and a branch part. The stem part has an anionic group and the branch part includes a backbone chain and a side chain.SELECTED DRAWING: None

Description

The present invention relates to (poly) anionic comb polymers and uses thereof. More specifically, the present invention relates to a novel (poly) anionic comb polymer and a production method thereof, and a cement admixture, an inorganic particle additive and a cement composition using the (poly) anionic comb polymer.

Various inorganic particles such as cement particles are usually used in various applications with various additives added to impart desired performance. Specifically, various cement admixtures typified by a cement dispersant are generally added to cement compositions such as cement paste, mortar, and concrete. As such an additive, a high-molecular substance (polymer) is widely used because the structure can be easily controlled according to the required performance. Examples of conventional polymer type additives include copolymers of (meth) acrylic acid and (meth) acrylic acid polyalkylene glycol monoester, and addition of alkylene oxide of acrylic acid and 3-methyl-buten-1-ol. And copolymers of acrylic acid and an alkylene oxide adduct of methallyl alcohol are known. In addition, there has been disclosed a hyperbranched polycarboxylic acid polymer cement dispersant obtained by copolymerizing a predetermined three monomers in an aqueous medium (see Patent Document 1).

Incidentally, comb polymers are known as polymers having a special structure. A comb polymer is a polymer having a comb structure in which a trunk portion (trunk polymer chain) has a trident branch point connected to a branch portion (branch polymer chain), and is a polymer having a special structure among graft polymers. . As such polymers, Non-Patent Documents 1 and 2 describe polymers obtained by an atom transfer radical polymerization (ATRP) method.

US Patent Application Publication No. 2013/0102749

Xavier Banquy, four others, “Bioinspired Bottle-Brush Oilymer Exhibits Low Friction and Amontons-like Behavior”, Journal of the American Chemical Society, 2014, Vol. 136, p. 6199-6202 Ryan Fenyves, 4 others, “Aqeous Self-Assembly of Giant Bottlebrush Block Copolymer Surfactants as Shape-Tunable Building Blocks”, Journal of the American Chemical Society, 2014, Vol. 136, p. 7762-7770

Applicants have examined or improved the state of a composition containing inorganic particles by imparting or improving the adsorptivity and dispersibility to various inorganic particles by the arrangement of the main chain structure of the polymer. It has been found that handling and workability can be improved. However, there are limits to the main chain structure of the polymer alone, and these performances can be further improved, and various additional performances (for example, clay resistance, early strength development, antifoaming properties, fly It has not been easy to impart a high level of compatibility with non-cement particles such as ash and slag, improvement of air entrainment, and improvement of the state of the cement composition.

The present invention has been made in view of the above situation, and provides a novel (poly) anionic comb polymer that can easily have a structure according to the required performance and is excellent in dispersion performance. Objective. Another object of the present invention is to provide a cement admixture, an inorganic particle additive, and a cement composition containing the polymer, as well as a production method for easily and efficiently obtaining the polymer.

The present inventor variously studied a novel polymer capable of easily imparting a structure according to the required performance, and has a comb structure having a trunk portion and a branch portion, and the branch portion itself includes a main chain and a side chain. It has been found that if the polymer has a special structure such as a comb structure, various functional groups can be easily introduced into the side chain of the branch portion, so that various required performances can be imparted or improved. And if it has an anionic group in the trunk part, it has been found that it becomes a polymer with excellent adsorption performance and dispersion performance (also referred to as fluidity performance) to inorganic particles, and comb polymers having such a structure have been developed so far. Found no new substance. Moreover, in order to obtain this comb polymer easily and efficiently, a production method comprising a step of reacting a macromonomer containing an unsaturated site derived from an ethylenically unsaturated monomer with an anionic group-containing monomer And that the comb polymer is particularly suitable for cement admixture use and inorganic particle additive use, and it is conceived that the above problems can be solved brilliantly. Reached.

In addition, since the polymer of patent document 1 has a hyperbranch type structure, it is clearly different from the polymer of a comb type structure. Non-Patent Documents 1 and 2 do not describe any comb polymers having an anionic group in the trunk portion. Furthermore, a copolymer of (meth) acrylic acid and (meth) acrylic acid polyalkylene glycol monoester, an alkylene oxide adduct of acrylic acid and 3-methyl-buten-1-ol, which are known copolymers, In the copolymer of acrylic acid and an alkylene oxide adduct of methallyl alcohol, one unit each includes a carboxyl group as an adsorbing group and a (poly) alkylene glycol chain as a dispersing group in the trunk portion. It has a comb structure introduced directly, and is different from a polymer having a comb structure having a side chain in a branch portion as in the present invention.

That is, the present invention relates to a comb polymer having a trunk portion and a branch portion, wherein the trunk portion has an anionic group, and the branch portion includes a main chain and a side chain. Comb polymer.
The present invention is also a method for producing the above (poly) anionic comb polymer, which comprises a macromonomer containing an unsaturated site derived from an ethylenically unsaturated monomer, and an anionic group-containing monomer. It is also a method for producing a (poly) anionic comb polymer comprising a step of reacting with a monomer.
The present invention is also a cement admixture containing the (poly) anionic comb polymer.
The present invention is also an inorganic particle additive containing the (poly) anionic comb polymer.
The present invention is also a cement composition comprising the (poly) anionic comb polymer, cement and water.
The present invention is described in detail below. A combination of two or more of the preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

[(Poly) anionic comb polymer]
The (poly) anionic comb polymer (also simply referred to as “comb polymer”) of the present invention is a comb polymer having a trunk portion and a branch portion, and the trunk portion is one or more types of anionic properties. It has one or more groups.

<Stem part>
Examples of the anionic group possessed by the trunk portion (also referred to as a core portion) include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a carbonic acid group, a silicic acid group, a phosphonic acid group, a nitric acid group, and a sulfuric acid group. Among these, at least one group selected from the group consisting of a carboxyl group, a sulfonic acid group, and a phosphoric acid group is preferable from the viewpoint of exhibiting more excellent dispersion performance. That is, a form in which the anionic group is at least one group selected from the group consisting of a carboxyl group, a sulfonic acid group, and a phosphoric acid group is one of the preferred forms of the present invention. More preferably, it has at least a carboxyl group as an anionic group.
The anionic group may be in the form of a salt. Such an anion salt group is also included in the “anionic group”.

The anionic group is preferably introduced into the comb polymer of the present invention by having a trunk portion having a structural unit derived from an anionic group-containing monomer. In other words, the comb polymer of the present invention preferably has one or more structural units derived from an anionic group-containing monomer in the trunk portion. The structural unit derived from the anionic group-containing monomer is a structure in which the unsaturated double bond portion (C═C) of the anionic group-containing monomer is a single bond (—C—C—). means.

As said anionic group containing monomer, 1 type (s) or 2 or more types, such as a carboxylic acid type monomer, a sulfonic acid type monomer, and a phosphoric acid type monomer, are preferable. That is, the comb polymer of the present invention is selected from the group consisting of a structural unit derived from a carboxylic acid monomer, a structural unit derived from a sulfonic acid monomer, and a structural unit derived from a phosphate monomer in the trunk portion. It is preferable to have at least one structural unit.
Needless to say, a monomer having two or more anionic groups in one molecule may be used as the anionic group-containing monomer.
Hereinafter, carboxylic acid monomers, sulfonic acid monomers, and phosphoric acid monomers suitable as the anionic group-containing monomer will be further described.

(I) Carboxylic acid monomer The carboxylic acid monomer is a compound containing an unsaturated double bond (carbon-carbon double bond) and a carboxyl group and / or a carboxylate.
Having a carboxyl group and / or a carboxylate has one or more groups represented by —COOR (R represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group) in one molecule. Means that. Examples of the metal atom include monovalent metals such as sodium, lithium, potassium, rubidium, and cesium; divalent metals such as magnesium, calcium, strontium, and barium; trivalent metals such as aluminum; other metals such as iron; Is mentioned. Examples of the organic amine group include alkanolamine groups such as monoethanolamine group, diethanolamine group and triethanolamine group; alkylamine groups such as monoethylamine group, diethylamine group and triethylamine group; polyamines such as ethylenediamine group and triethylenediamine group Group; etc. are mentioned. The carboxylate is preferably an ammonium salt, a sodium salt or a potassium salt, and more preferably a sodium salt.

As the carboxylic acid monomer, a monocarboxylic acid monomer containing an unsaturated double bond and one carboxyl group or carboxylate in one molecule; an unsaturated double bond and 2 in one molecule Dicarboxylic acid monomers containing two carboxyl groups or carboxylates are preferred. In this case, since the comb polymer of the present invention can exhibit higher dispersion performance, it is more suitable as a polymer for an inorganic particle additive or a cement admixture.

Examples of the monocarboxylic acid monomer include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, α-hydroxyacrylic acid, α-hydroxymethylacrylic acid and derivatives thereof, and salts thereof. Is mentioned. In addition, a half ester of a dicarboxylic acid monomer and an alcohol can be used as the monocarboxylic acid monomer.
Acrylic acid and methacrylic acid are collectively referred to as “(meth) acrylic acid”.

Examples of the dicarboxylic acid monomer include unsaturated dicarboxylic acids such as maleic acid, itaconic acid, citraconic acid, fumaric acid, and mesaconic acid, and salts and anhydrides thereof.

Among the carboxylic acid monomers described above, (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid and salts thereof are preferred from the viewpoint of polymerizability. More preferably, it is (meth) acrylic acid and / or a salt thereof (these are collectively referred to as a (meth) acrylic acid monomer), and the comb polymer is a (meth) acrylic acid monomer. By having the derived structural unit, it becomes possible to exhibit even better dispersion performance in a smaller amount. More preferably, it is an acrylic acid monomer (acrylic acid and / or a salt thereof).

(Ii) Sulfonic acid-based monomer The sulfonic acid-based monomer is a compound containing an unsaturated double bond (carbon-carbon double bond), a sulfonic acid group and / or a sulfonate.
The term “containing a sulfonic acid group and / or a sulfonate” means that a group represented by —SO ₃ R (R represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group) is 1 or 2 in one molecule. It means having 2 or more. The sulfonate is preferably an ammonium salt, sodium salt or potassium salt, more preferably a sodium salt.

Specific examples of the sulfonic acid monomer include vinyl sulfonic acid, (meth) allyl sulfonic acid, methallyloxybenzene sulfonic acid, isoprene sulfonic acid, 2-methylpropane sulfonic acid (meth) acrylamide, and styrene sulfone. Examples thereof include unsaturated sulfonic acids such as acid, 2-hydroxy-3-allyloxysulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate and sulfobutyl (meth) acrylate, and salts thereof. Among these, acrylate is particularly preferable.

(Iii) Phosphoric monomer The phosphoric acid monomer is a compound containing an unsaturated double bond (carbon-carbon double bond) and a phosphate group and / or a phosphate.
The phrase “containing a phosphate group and / or a phosphate” means — (PO ₄ ) _m (R) _n (R represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group, and two or more different groups may be used. m is the valence of PO ₄ , and n is the valence of R. This means that one or more groups represented by 1 are included in one molecule. The phosphate is preferably an ammonium salt, a sodium salt or a potassium salt, more preferably a sodium salt.

As the phosphoric acid monomer, for example, an esterified product of an unsaturated carboxylic acid and a compound having two or more hydroxyl groups in one molecule, and an esterified product of phosphoric acid are suitable.
Specifically, esterified products of hydroxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate and phosphoric acid; Suitable are esterified products of polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate and phosphoric acid. Among these, acrylate is particularly preferable.

The trunk portion is preferably the following general formula (1):

(Wherein R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom, a methyl group or — (CH ₂ ) _p COOR. Z is the same or different and represents —COOR, —SO ₃ R; or, _- .x representing the _{(PO 4) m (R)} n is, .R representing the number of 1 or more, a hydrogen atom, a metal atom, an ammonium group or an organic amine group, or may be two or more different kinds .m is the valency of PO _4, n is, .- (CH _{2) p} COOR represents the valence of R is Z or other - (CH ₂₎ form a _p COOR and anhydrides P is an integer of 0 to 2), and includes a structural unit derived from an anionic group-containing monomer. The metal atom and the organic amine group are as described above.

In the general formula (1), R ² , R ³ and R ⁴ are the same or different and represent a hydrogen atom or a methyl group. From the viewpoint of further improving the dispersion performance and from the viewpoint of production, R ² and R ³ preferably represents a hydrogen atom, more preferably R ² , R ³ and R ⁴ represent a hydrogen atom.

Z represents —COOR, —SO ₃ R, or — (PO ₄ ) _m (R) _n , among which —COOR is preferable. That is, it is preferable that the trunk portion includes a structural unit derived from a carboxylic acid monomer.

x may be a number of 1 or more, but is preferably a number of 2 or more. The upper limit of x is not particularly limited as long as it is appropriately set according to the performance required for the comb polymer. For example, the balance between the dispersing group and the adsorbing group in the polymer (introducing many anionic groups as adsorbing groups) If it is too much, the introduction amount of the dispersing group will be relatively lowered, and the dispersion performance of the inorganic particles will not be improved.) If the adsorbing group is introduced too much, the function of crosslinking and aggregating the inorganic particles will work. From the viewpoint that the dispersibility of the particles does not become better, it is preferably 300 or less. More preferably, it is 200 or less.

The comb-shaped polymer also has a structural unit (preferably a structural unit derived from an ethylenically unsaturated monomer and a structural unit derived from an anionic group-containing monomer) that serves as a trident branch point connected to the branch portion at the trunk portion. In addition, the comb polymer may have a monomer other than an anionic group-containing monomer (“other monomer”) in the trunk portion. The structural unit derived from the other monomer means a structure in which the unsaturated double bond portion of the other monomer becomes a single bond. The proportion of the structural unit derived from the other monomer is 50% by mass or less with respect to 100% by mass of the total amount of the structural unit derived from the anionic group-containing monomer and the structural unit derived from the other monomer. Preferably, more preferably 30% by weight or less, still more preferably 10% by weight or less, Preferably to 0 mass%.
The other monomer is not particularly limited, and for example, one or two of an ester of an anionic group-containing monomer, a nonionic monomer, a cationic monomer, and a betaine monomer described later The above can be used.

Here, the ratio of the structural unit derived from the anionic group-containing monomer in the trunk portion of the comb polymer is not particularly limited as long as it is appropriately set according to the performance required for the comb polymer. For example, the total amount of the structural unit of the trunk portion (the structural unit derived from the anionic group-containing monomer, the structural unit derived from the other monomer described above, and the structural unit serving as a trident branch point connected to the branch portion (preferably From the viewpoint of the adsorption performance to the inorganic particles, the total amount with the structural unit derived from the ethylenically unsaturated monomer) is preferably 1% by mass or more, more preferably 3% by mass or more. It is.

<Branch part>
A branch portion (also referred to as an arm portion) of the comb polymer includes a main chain and a side chain. A side chain means the carbon chain branched from the main chain among branch parts. Therefore, the comb polymer of the present invention has a comb structure in which the branch portion itself has a trident branch point connected to the side chain in the main chain.

The main chain of the branch part preferably includes a structural unit derived from an ethylenically unsaturated monomer. This makes it easier to impart or improve various performances required for the comb polymer. Thus, the form in which the main chain of the branch part includes a structural unit derived from an ethylenically unsaturated monomer is one of the preferred forms of the present invention. The structural unit derived from an ethylenically unsaturated monomer is preferably the following general formula (2):

(In the formula, R ^1, same or different, .Q represents a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, .y representing the side chain of the branch portion represents the number of 1 or more.) Can be expressed as

In the general formula (2), R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms. From the viewpoint of production for obtaining the comb polymer of the present invention, R ¹ has 1 to 3 carbon atoms. The hydrocarbon group is preferably. As the hydrocarbon group, a linear or branched alkyl group is preferable, and a methyl group is particularly preferable.
When the main chain of the branch part has two or more structural units represented by the general formula (2) (that is, when y is 2 or more), R ¹ and Q may be the same or different. It may be.

y may be a number of 1 or more, but is preferably a number of 2 or more. The upper limit of y is not particularly limited as long as it is appropriately set according to the performance required for the polymer. For example, the balance between the dispersing group and the adsorbing group in the polymer (introducing too many branch parts that are the dispersing group) The amount of adsorbing groups introduced is relatively low, and the adsorption performance to inorganic particles will not be better.) If too many dispersing groups are introduced, the molecular weight will be too large and the dispersibility of inorganic particles will be better. From the standpoint of not becoming anything, it is preferably 300 or less. More preferably, it is 200 or less.

Here, the ratio of the constituent unit derived from the ethylenically unsaturated monomer in the main chain of the branch portion of the comb polymer may be appropriately set according to the performance required for the comb polymer. Not. For example, 50% by mass with respect to 100% by mass of the total amount of structural units constituting the main chain of the branch portion (total amount of structural units derived from ethylenically unsaturated monomers and structural units derived from other monomers). % Or more is preferable. More preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, Most preferably, it is 90 mass% or more.

The comb polymer branch also has side chains. The side chain is not particularly limited, and is preferably a carbon chain containing a functional group corresponding to the required performance. By introducing various functional groups according to the required performance into this side chain, the comb polymer of the present invention can exhibit the performance of the functional group in addition to the dispersion performance. One side chain may have two or more types of functional groups, and the branch portion of the comb polymer has two or more side chains (for example, y in the general formula (2) is When the number is 2 or more), the functional groups of each side chain may be the same or different. The side chains themselves may be the same or different.
Thus, in the present invention, a plurality of the same or different functional groups can be introduced into the side chain of the branch part, and in this case, the performance derived from each functional group can be exhibited simultaneously. The comb polymer of the present invention also has an advantageous effect in this respect.

The branch portion preferably has a sulfur atom so that a desired functional group can be easily introduced into the side chain. Among them, the following general formula (3):

(In formula, X represents a C1-C8 hydrocarbon group. AO represents a C2-C8 oxyalkylene group. Y represents a C1-C5 hydrocarbon group. A Is a number of 0 or 1, b is a number of 0 to 200, c is a number of 0 or 1, and d is a number of 0 or 1. It is preferable to include at least. Thus, the form in which the said branch part contains at least group represented by General formula (3) is one of the suitable forms of this invention.
In general formula (3), the bond on the side opposite to the oxygen atom _of- (X) _a- and the bond on the side opposite to-(Y) _d- of the sulfur atom are arbitrary.

In the general formula (3), X represents a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group is preferably a linear or branched alkylene group. Moreover, as carbon number of a hydrocarbon group, it is preferably 1-5, and more preferably is 1-2. X is particularly preferably a methylene group or an ethylene group. By having X of such a preferable structure, it becomes possible to fully exhibit the effect of this invention.

The number (a) of X in the general formula (3) is 0 or 1, but is preferably 1.

AO represents an oxyalkylene group having 2 to 8 carbon atoms. Specific examples include an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxyisobutylene group, an oxymethylethylene group, an oxyoctylene group, and an oxystyrene group. Especially, it is preferable that it is a C2-C4 oxyalkylene group, More preferably, it is an oxyethylene group.

The (poly) alkylene glycol chain represented by — (AO) _b — may be formed by two or more oxyalkylene groups. In this case, the addition form of two or more oxyalkylene groups is Any form such as random addition, block addition, and alternate addition may be used. As a combination in the case of having two or more oxyalkylene groups, (oxyethylene group, oxypropylene group), (oxyethylene group, oxybutylene group), (oxyethylene group, oxystyrene group) are preferable. Among these, (oxyethylene group, oxypropylene group) is more preferable.

b is the average addition mole number of AO in General formula (3), and is the number of 0-200. b should just be set suitably according to the performance requested | required of a comb polymer, and is not specifically limited. For example, from the viewpoint of further imparting dispersion performance, b is preferably as large as possible. For example, it is preferably 5 or more, more preferably 10 or more, still more preferably 20 or more, and particularly preferably 50 or more. Further, from the viewpoint of reducing the viscosity of a cement composition such as concrete, or from the viewpoint of sufficiently suppressing hydrolysis when obtaining a comb polymer, b is preferably as small as possible. Preferably it is 50 or less, more preferably 20 or less, particularly preferably 10 or less, and most preferably 4 or less.

Here, from the viewpoint of improving the clay resistance, it has been found from the previous studies that (poly) alkylene glycol (especially (poly) ethylene glycol) chains are adsorbed between the clay layers. Conventional polycarboxylic acid dispersants having glycol chains are also adsorbed between the clay layers. As a result, an increase in the amount of the dispersant incorporated between the clay layers results in a decrease in the amount of adsorption to the inorganic particles that should be dispersed, and an increase in the amount added to disperse the inorganic particles. From this point of view, in order to prevent incorporation between the clay layers, b is preferably as small as possible. For example, it is preferably 20 or less, more preferably 10 or less, still more preferably 4 or less, and particularly preferably 2 or less. In the following, it is most preferably 1 or 0.

Here, when b is 1 or more, the proportion of oxyethylene groups is 50 mol% with respect to 100 mol% of the total amount of oxyalkylene groups constituting the (poly) alkylene glycol chain represented by — (AO) _b —. It is suitable that it is above. This further improves the dispersion performance of the comb polymer. More preferably, it is 70 mol% or more, More preferably, it is 80 mol% or more, Especially preferably, it is 90 mol% or more, Most preferably, it is 100 mol%.

The number (c) of —C (═O) — in the general formula (3) is 0 or 1, but is preferably 1.

Y represents a hydrocarbon group having 1 to 5 carbon atoms, and the hydrocarbon group is preferably a linear or branched alkylene group. Moreover, as carbon number of a hydrocarbon group, Preferably it is 1-3, More preferably, it is 1-2. Y is particularly preferably a methylene group or an ethylene group. By having Y of such a preferable structure, it becomes possible to exhibit the effect of this invention more fully.

The number (d) of Y in the general formula (3) is 0 or 1, but is preferably 1.

The functional group that is preferably introduced into the side chain of the branch portion may be any functional group that meets the performance required for the comb polymer. For example, one type or two or more types of nonionic group, cationic group, anionic group or betaine group are suitable. That is, a form in which the side chain of the branch part includes at least one functional group selected from the group consisting of a nonion group, a cation group, an anion group, and a betaine group is one of the preferred forms of the present invention.

Although the preferable form of these functional groups is as mentioning later, an example of the effect of the functional group introduced below is given.
In the case of a nonionic group, the dispersion effect of inorganic particles due to steric hindrance can be expected particularly in the case of an alkylene oxide chain. Moreover, if it is an alkyl group, the effect of improving the state of the composition containing inorganic particles (for example, a cement composition such as concrete) can be expected.
In the case of a cationic group, an amino group-derived cationic group is preferable, and an improvement in the strength of a cement composition such as concrete and an improvement in the state can be expected.
In the case of an anionic group, it can be expected that inorganic particles are dispersed by an electric repulsion effect by introducing an anionic group such as a carboxylic acid group, a sulfonic acid group, and a phosphoric acid group.
In the case of a betaine group, the polymer chain having the betaine group greatly spreads due to repulsion between the betaine groups in water or salt water, so that it can be expected to effectively disperse the inorganic particles by steric repulsion and has excellent water solubility. Therefore, it can be expected that the foaming property in water is low (air entrainment property in water is low).

Here, when the side chain of the branch part of a comb-shaped polymer contains two or more types of functional groups, the performance derived from each functional group can be exhibited simultaneously. In addition, when the side chain of the branch part of the comb-shaped polymer includes a side chain including a cationic group and a side chain including an anionic group, the comb-shaped polymer has the above-described effect due to including the cationic group and the anionic group. In addition, it is possible to exhibit the same effect as when a betaine group is included.

Various functional groups have a constitutional unit derived from a monomer (referred to as a functional group-containing monomer) containing one or more of the functional groups in the side chain of the branch portion of the comb polymer. It is preferably introduced into the comb polymer. In other words, the comb polymer of the present invention preferably has a structural unit derived from a functional group-containing monomer in the side chain of the branch portion. Among them, the main chain of the branch portion of the comb polymer has a structural unit derived from the ethylenically unsaturated monomer represented by the general formula (2), and Q in the formula (2) is a functional group. It is preferable to represent a side chain having a structural unit derived from the containing monomer. The structural unit derived from the functional group-containing monomer means a structure in which the unsaturated double bond portion (C═C) of the functional group-containing monomer is a single bond (—C—C—). .

The structural unit derived from the functional group-containing monomer is preferably the following general formula (4):

(Wherein R ⁵ , R ⁶ and R ⁷ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms. R ⁸ represents an arbitrary functional group). . Thus, the form in which the side chain of the branch part contains at least the structural unit derived from the functional group-containing monomer represented by the general formula (4) is one of the preferred forms of the present invention.

In the said General formula (4), R < ⁵ >, R < ⁶ > and R <^7> are the same or different and represent a hydrogen atom or a C1-C3 hydrocarbon group. As the hydrocarbon group, a linear or branched alkyl group is preferable, and a methyl group is more preferable. From the viewpoint of production for obtaining the comb polymer of the present invention, R ⁵ and R ⁶ represent a hydrogen atom, and R ⁷ represents a hydrocarbon group having 1 to 3 carbon atoms (particularly preferably a methyl group). It is particularly preferred.

R ⁸ represents an arbitrary functional group, but in the present invention, R ⁸ can be appropriately changed according to the required performance. Moreover, when the side chain of the comb polymer has two or more structural units represented by the general formula (4), the same or different functional groups can be introduced as R ⁸ in each structural unit. In this case, the performance derived from each functional group can be exhibited simultaneously. R ⁸ is preferably a nonionic group, a cationic group, an anionic group or a betaine group, and preferred forms thereof are as described above.

When the side chain of the branch part of the comb polymer includes at least a structural unit represented by the general formula (4), the number of the structural unit represented by the general formula (4) in one branch part is comb-shaped. Although it should just set suitably according to the performance requested | required of a polymer, it is not specifically limited, For example, it is suitable that it is 1-300. For example, from the viewpoint of further improving the performance derived from the functional group introduced into R ⁸ , the larger the number, the better. More preferably, it is 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, from the viewpoint of further improving performance derived from the anionic group of the trunk portion, 250 or less is preferable, and 200 or less is more preferable.

As said functional group containing monomer, 1 type (s) or 2 or more types, such as a nonionic monomer, a cationic monomer, an anionic monomer, and a betaine monomer, are preferable. That is, the comb polymer of the present invention includes a nonionic monomer-derived structural unit, a cationic monomer-derived structural unit, an anionic monomer-derived structural unit, and a betaine-based monomer in the side chain of the branch portion. It is preferable to have at least one structural unit selected from the group consisting of body-derived structural units.
Needless to say, a monomer containing two or more functional groups may be used as the functional group-containing monomer.
Hereinafter, nonionic monomers, cationic monomers, anionic monomers and betaine monomers suitable as functional group-containing monomers will be further described.

(I) Nonionic monomer A nonionic monomer is a compound containing an unsaturated double bond (carbon-carbon double bond) and a nonionic group. Examples of nonionic groups (also referred to as nonionic groups and nonionic groups) include ether groups, hydroxyl groups, amide groups, aromatic vinyl groups, N-vinyl lactam groups, and alkyl groups. Specific examples of the ether group include (alkoxy) (poly) alkylene glycol groups and alkyl ether groups, and examples of the hydroxyl group include hydroxyalkyl groups such as a hydroxyethyl group and a hydroxypropyl group.

By having a nonionic group in the side chain of the branch part of the comb polymer, the comb polymer has excellent dispersion performance, as well as clay resistance, early strength development, and drying shrinkage reduction. Even better. In particular, by including a hydroxyl group as a nonionic group, the clay resistance is further improved, and by including an (alkoxy) (poly) alkylene glycol group, early strength development and dry shrinkage reduction are further improved. It will be excellent.

Specific examples of the nonionic monomer include unsaturated (poly) alkylene glycol monomers; hydroxyl group-containing monomers; amide monomers; aromatic vinyl monomers; N-vinyl. And lactam monomers; ester monomers; and the like. Of these, unsaturated (poly) alkylene glycol monomers and hydroxyl group-containing monomers are preferred.
These nonionic monomers will be further described below.

-Unsaturated (poly) alkylene glycol monomer-
Examples of the unsaturated (poly) alkylene glycol monomer include the following general formula (I):

(Wherein, ^{R 9} and ^{R 10} are the same or different, .p representing a hydrogen atom or a methyl group, .q represents an integer of 0 to 2, .A ¹ O represents 0 or 1, the same Alternatively, it represents an oxyalkylene group having 2 to 18 carbon atoms, r is the average number of added moles of the oxyalkylene group represented by A ¹ O, and is a number from 1 to 300. R ¹¹ is hydrogen. A compound represented by an atom or a hydrocarbon group having 1 to 18 carbon atoms is preferred.

In the general formula ^{(I), - (A 1} O) r - as is represented by (poly) number of carbon atoms in the alkylene glycol chain, preferably 2 to 8, more preferably 2-4. More preferably, it is 2. When the (poly) alkylene glycol chain is formed from two or more oxyalkylene groups, the addition form may be any addition form such as random addition, block addition, and alternate addition. .

In the (poly) alkylene glycol chain, the average repeating number (average added mole number) n of A ¹ O is preferably a number of 2 to 300. Within such a range, the polymerization reactivity of the unsaturated (poly) alkylene glycol monomer and the hydrophilicity of the resulting comb polymer become more sufficient. From the viewpoint of improving the dispersibility of the inorganic particles, the average added mole number is more preferably 5 to 150, particularly preferably 5 to 100, and most preferably 5 to 75. From the viewpoint of improving clay resistance, the average number of added moles is preferably 2 to 100, more preferably 2 to 50, still more preferably 2 to 20, particularly preferably 2 to 10, and most preferably 2 to 5. .

In the general formula (I), R ⁹ and R ¹⁰ are the same or different and each represents a hydrogen atom or a methyl group, and p is 0, 1 or 2. Therefore, when q = 0, the alkenyl group represented by “C (R ⁹ ) H═C (R ¹⁰ ) — (CH ₂ ) _p —” corresponds to an alkenyl group having 2 to 6 carbon atoms. The alkenyl group preferably has 3 to 5 carbon atoms.
Specific examples of the alkenyl group represented by the above “C (R ⁹ ) H═C (R ¹⁰ ) — (CH ₂ ) _p —” include, for example, a vinyl group, an allyl group, a methallyl group, a 3-butenyl group, 3-methyl-3-butenyl group etc. are mentioned. Among these, a vinyl group, an allyl group, a methallyl group, and a 3-methyl-3-butenyl group are preferable.
As R ⁹ and R ¹⁰ , it is particularly preferable that R ⁹ is a hydrogen atom and R ¹⁰ is a methyl group.

In the general formula (I), R ¹¹ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. In the case where R ¹¹ represents a hydrocarbon group, for example, from the viewpoint of further improving the hydrophilicity of the comb polymer, the carbon number is preferably 1 to 12, more preferably 1 to 8, and still more preferably. It is 1-4, Most preferably, it is 1-3, Most preferably, it is 1-2.
As the hydrocarbon group, for example, an alkyl group (straight chain, branched chain or cyclic), a phenyl group, an alkyl-substituted phenyl group, an alkenyl group, an alkynyl group, an aryl group and the like are preferable. Among these, an alkyl group (straight chain, branched chain or cyclic) is more preferable.
R ¹¹ is particularly preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or an alicyclic alkyl group having 3 carbon atoms, and most preferably a hydrogen atom, a methyl group or An ethyl group.

In the general formula (I), q represents 0 or 1, and when q = 0, the monomer is a monomer having an ether structure (unsaturated (poly) alkylene glycol ether monomer). Also called). Further, when q = 1, the monomer is a monomer having an ester structure (also referred to as an unsaturated (poly) alkylene glycol ester monomer). Specifically, the ester group represented by the above “C (R ⁹ ) H═C (R ¹⁰ ) — (CH ₂ ) _p — (CO) q—O—” is, for example, p = 0. Acrylic acid esters and methacrylic acid esters are preferred. Among these, methacrylic acid esters are particularly preferable.

As the unsaturated (poly) alkylene glycol ether monomer, an unsaturated alcohol (poly) alkylene glycol adduct is preferable. Specifically, for example, vinyl alcohol alkylene oxide adduct, (meth) allyl alcohol alkylene oxide adduct, 3-buten-1-ol alkylene oxide adduct, isoprene alcohol (3-methyl-3-buten-1-ol) ) Alkylene oxide adduct, 3-methyl-2-buten-1-ol alkylene oxide adduct, 2-methyl-3-buten-2-ol alkylene oxide adduct, 2-methyl-2-buten-1-ol alkylene An oxide adduct, 2-methyl-3-buten-1-ol alkylene oxide adduct, and the like are preferable.

As the unsaturated (poly) alkylene glycol ester monomer, an unsaturated carboxylic acid (poly) alkylene glycol ester compound is preferable, and (alkoxy) (poly) alkylene glycol mono (meth) acrylate and (hydroxy) ) (Poly) alkylene glycol mono (meth) acrylate is more preferred. More preferred are alkoxy (poly) ethylene glycol mono (meth) acrylate and hydroxy (poly) ethylene glycol mono (meth) acrylate. Among these, (meth) acrylate is preferable, and methacrylate is particularly preferable.

-Hydroxyl group-containing monomer-
As the hydroxyl group-containing monomer, a (meth) acrylate containing a hydroxyl group (hydroxyl group) is suitable. For example, hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 4-hydroxybutyl (meth) acrylate, mono (meth) acrylate of polyhydric alcohol (for example, glycerol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, etc.), caprolactone modified (meth) acrylate, etc. . Moreover, the alkyl ether (For example, 2-ethoxyethyl (meth) acrylate, 2-ethoxypropyl (meth) acrylate, carbitol (meth) acrylate, etc.) of various (meth) acrylates is also mentioned. Among these, hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate are preferable, and methacrylate is particularly preferable.

-Amide monomer-
Examples of the amide monomer include (meth) acrylamide or a quaternary salt thereof (a quaternary salt with an acidic substance such as hydrochloric acid, sulfuric acid, sulfonic acid, and acetic acid, an alkyl halide such as methyl chloride, methyl iodide, and the like. N-alkyl (meth) acrylamides such as N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, or quaternary salts thereof (hydrochloric acid, sulfuric acid, sulfone) Quaternary salts with acidic substances such as acids and acetic acid, quaternary salts with alkyl halides such as methyl chloride and methyl iodide); hydroxyalkyl (meth) acrylamides such as N-methylol (meth) acrylamide; N- Methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, etc. Alkoxyalkyl (meth) acrylamide; N, N-dialkyl (meth) acrylamide such as N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide; diacetone (meth) acrylamide; N-vinylformamide; -Vinylacetamide; alkylene oxide adduct of (meth) acrylamide; Of these, methacrylic amide compounds are particularly preferred.

-Aromatic vinyl monomers-
Examples of the aromatic vinyl monomer include styrene, vinyl toluene, α-methyl styrene, methoxy styrene and the like.

-N-vinyl lactam monomer-
Examples of the N-vinyl lactam monomer include N-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl imidazoline and the like.

-Ester monomer-
Examples of ester monomers include esters of (meth) acrylic acid with linear or branched saturated or unsaturated alcohols having 1 to 18 carbon atoms; (meth) acrylic acid and aromatic rings or heterocyclic rings. An ester with an alcohol having Examples of the alcohol having 1 to 18 carbon atoms include lower alcohols such as methanol, ethanol, propyl alcohol, isopropyl alcohol, butanol, sec-butanol and ter-butanol; higher alcohols such as octyl alcohol, dodecyl alcohol and cetyl alcohol; Can be mentioned. Examples of the alcohol having an aromatic ring include phenol, naphthol, benzyl alcohol and the like.

(Ii) Cationic monomer A cationic monomer is a compound containing an unsaturated double bond (carbon-carbon double bond) and a cationic group. As the cationic group, for example, a tertiary amine base, a quaternary ammonium base, a hydrazide group, a pyridinium base and the like are suitable. Of these, tertiary amine bases and quaternary ammonium bases are preferred.

By having a cationic group in the side chain of the branch part of the comb polymer, the comb polymer has excellent dispersion performance, and in addition, a composition containing the comb polymer (for example, a cement composition) ) Is further improved and handling and workability are improved.

Specific examples of the cationic monomer include tertiary amine salts and quaternary ammonium salts. Examples of the tertiary amine salt include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 3-dimethylamino-2-hydroxypropyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, and the like. Examples thereof include salts obtained by neutralizing a primary amine with an acid (for example, various acids such as hydrochloric acid and sulfuric acid).

Examples of the quaternary ammonium salt include (meth) acryloyloxyalkyltrialkylammonium salts such as 2- (meth) acryloyloxyethyltrimethylammonium chloride; vinylbenzyltrialkylammonium salts such as vinylbenzyltrimethylammonium chloride; dimethyl In addition to diallyl diallylammonium salts such as diallylammonium chloride and diethyldiallylammonium chloride; compounds obtained by quaternizing tertiary amines (for example, methyl chloride quaternary salt of dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate) Methyl chloride quaternary salt, dimethylaminoethyl methacrylate benzyl chloride quaternary salt, dimethylaminopropylacrylamide methyl chloride Quaternary salt, etc.) and the like. Among these, methacrylic quaternary salts are particularly preferable.

(Iii) Anionic monomer Anionic monomer is a compound containing an unsaturated double bond (carbon-carbon double bond) and an anionic group. Examples of the anionic group include the various anionic groups described above. Among these, from the viewpoint of exhibiting more excellent dispersion performance, one or more of carboxyl group, sulfonic acid group, phosphoric acid group and the like are preferable, and sulfonic acid group is more preferable.

By having an anionic group in the side chain of the branch portion of the comb polymer, the comb polymer has excellent dispersion performance due to the electric repulsion effect, and also has excellent clay resistance. Moreover, the state of the composition (for example, cement composition) containing the comb polymer is further improved, and the handleability and workability are improved.

Specific examples of the anionic monomer include carboxylic acid monomers, sulfonic acid monomers, and phosphoric acid monomers described above as preferred examples of anionic group-containing monomers. is there. These preferable forms are as described above. Among these, methacrylic acid and / or a salt thereof (collectively referred to as a methacrylic monomer) are particularly preferable as the anionic monomer introduced into the branch portion.

(Iv) Betaine monomer A betaine monomer is a compound containing an unsaturated double bond (carbon-carbon double bond) and a betaine group. A betaine group (also referred to as a zwitterionic group) means a group containing a cation and an anion. Therefore, a betaine monomer includes an unsaturated double bond, a cationic group, and an anion group. It can also be said to be a compound. As the cationic group and the anionic group, the above-mentioned groups are preferable, and it is preferable that each of these groups is one in each molecule.

By having a betaine group in the side chain of the branch portion of the comb polymer, the comb polymer has excellent dispersion performance, as well as excellent clay resistance and air entrainment. .

Specific examples of the betaine monomer include 2-methacryloyloxyethyl-phosphorylcholine, [3- (methacryloylamino) propyl] dimethyl (3-sulfopropyl) aninium hydroxide, [2- (methacryloyl). Oxy) ethyler] dimethyl (3-sulfopropyl) anninium hydroxide and the like. Among these, methacrylate is particularly preferable.

More preferably, the branch part of the comb polymer includes a group represented by the general formula (3) and a structural unit derived from the functional group-containing monomer represented by the general formula (4). It is. More preferably, the group represented by the general formula (3) includes a group having a structure in which the structural unit represented by the general formula (4) is adjacent. Such a group has the following general formula (5):

(The symbols in the formula are the same as those in the general formulas (3) and (4). E represents the general formula (4) for one group represented by the general formula (3). It represents the number of structural units represented.) Thus, the form in which the said branch part contains group represented by General formula (5) is one of the suitable forms of this invention. Particularly preferably, the main chain of the branch portion of the comb polymer has a structural unit derived from the ethylenically unsaturated monomer represented by the general formula (2), and Q in the general formula (2) is This is a form represented by the general formula (5).

In the general formula (5), e is not particularly limited as long as it is appropriately set according to the performance required for the comb polymer, but is preferably 1 to 300, for example. For example, from the viewpoint of further improving the performance derived from the functional group introduced into R ⁸ , the larger e is, the better. More preferably, it is 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, from the viewpoint of further improving performance derived from the anionic group of the trunk portion, 250 or less is preferable, and 200 or less is more preferable.

The side chain of the branch part may also contain a group having a structure in which a constituent unit derived from an unsaturated monomer other than the functional group-containing monomer is adjacent to the group represented by the general formula (3). In this case, in the comb polymer, the structural unit derived from the unsaturated monomer other than the functional group-containing monomer in the group represented by the general formula (5) and the group represented by the general formula (3). It is preferable that the group represented by the general formula (5) is 50% by mass or more with respect to the total amount of 100% by mass with the group having an adjacent structure. Thereby, various performances derived from the functional group are further exhibited. More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more, Most preferably, it is 100 mass%.
The unsaturated monomer other than the functional group-containing monomer is not particularly limited, and one or more kinds of any unsaturated monomer can be used.

In the above comb polymer, the abundance ratio between the trunk portion and the branch portion, and the abundance ratio between the main chain and the side chain contained in the branch portion are the performance and application required for the comb polymer, ease of production, etc. It may be set as appropriate in consideration. For example, the abundance ratio between the trunk portion and the branch portion (trunk portion / branch portion, mass ratio) is preferably 1 to 99/99 to 1, more preferably 1 to 50/99 to 50, and still more preferably. 5-30 / 95-70. The abundance ratio (main chain / side chain, mass ratio) between the main chain and the side chain contained in the branch part is preferably 1 to 99/99 to 1, more preferably 1 to 50/99 to 50, more preferably 5-30 / 95-70.

The molecular weight of the comb polymer varies depending on the application, required performance, and the like. For example, the weight average molecular weight is preferably 1000 to 500,000. More preferably, it is 5000-400,000, More preferably, it is 10,000-300,000, Most preferably, it is 10,000-200,000. In addition, when using for a cement admixture or an inorganic particle additive use, for example, it is especially preferable that an upper limit is 200,000 from a viewpoint of viscosity reduction.
The number average molecular weight is preferably 1000 to 500,000. More preferably, it is 5000-400,000, More preferably, it is 10,000-300,000.
In the present specification, the molecular weight of the polymer can be determined by an analysis method described in Examples (LS-GPC, GPC means gel permeation chromatography) described later.

As preferred examples of the comb polymer of the present invention, some of the forms having a carboxyl group as an anionic group in the trunk portion are conceptually briefly shown below. The comb polymer of the present invention is not limited to these.
In the following conceptual diagram, only characteristic portions are extracted and described. The wavy line represents a (poly) alkylene glycol group, and “HEMA” represents a portion derived from 2-hydroxyethyl methacrylate (a portion other than a methacrylic double bond).

[Method for producing comb polymer]
The comb polymer of the present invention is obtained by reacting a macromonomer containing an unsaturated site derived from an ethylenically unsaturated monomer (also simply referred to as “macromonomer”) with an anionic group-containing monomer. Is preferred. In the comb polymer of the present invention, it is preferable that the branch portion is constituted from the macromonomer, and it is preferable that the trunk portion is constituted from the anionic group-containing monomer. Thus, the method for producing a (poly) anionic comb polymer comprising a step of reacting a macromonomer containing an unsaturated site derived from an ethylenically unsaturated monomer with an anionic group-containing monomer is the present invention. It is one of.

In the above production method, the preferred form and the like of the anionic group-containing monomer are as described above. In addition to the reaction step of the macromonomer and the anionic group-containing monomer, one or more other steps may be included as necessary. Other steps are not particularly limited, and examples include a step applied in a normal reaction step (for example, a purification step).
In addition, each compound used by the said manufacturing method can use 1 type (s) or 2 or more types, respectively.

<Macromonomer>
The macromonomer is a compound containing an unsaturated site derived from an ethylenically unsaturated monomer. The weight average molecular weight varies depending on the use and required performance of the comb polymer of the present invention, but is preferably, for example, 500 to 50,000, more preferably 500 to 30,000, still more preferably 1000 to 10,000. is there.

As an unsaturated site | part derived from the said ethylenically unsaturated monomer, following General formula (6):

(The symbols in the formula are preferably the same as the symbols in the general formulas (2) and (3)). This makes it easier to impart or improve various performances required for the comb polymer.

The macromonomer also preferably has a sulfur atom so that a desired functional group can be easily introduced. Among them, the following general formula (7):

(The symbols in the formula are the same as the symbols in the general formulas (2) and (3)). Thus, the form in which the macromonomer includes the group represented by the general formula (7) is one of the preferred forms of the present invention.
In general formula (7), the bond on the side opposite _to- (Y) _d- of the sulfur atom is arbitrary.

The macromonomer preferably further contains a structural unit derived from an unsaturated monomer. That is, the macromonomer includes an unsaturated site derived from an ethylenically unsaturated monomer and a structural unit derived from an unsaturated monomer different from the ethylenically unsaturated monomer (simply referred to as “unsaturated monomer derived”). It is preferable to include a “structural unit”. In the comb polymer of the present invention, it is preferable that the side chain of the branch portion is composed of the structural unit derived from the unsaturated monomer.

In such a macromonomer, the abundance ratio between the unsaturated site derived from the ethylenically unsaturated monomer and the structural unit derived from the unsaturated monomer (unsaturated site derived from the ethylenically unsaturated monomer / unsaturated) The monomer-derived structural unit and mass ratio may be appropriately set in consideration of the performance and application required for the comb polymer, ease of production, and the like. For example, it is preferably 1 to 99/99 to 1, more preferably 1 to 50/99 to 50, and still more preferably 3 to 30/97 to 70.

The constituent unit derived from the unsaturated monomer preferably includes a functional group corresponding to the performance required for the comb polymer of the present invention. Therefore, the unsaturated monomer that forms the structural unit derived from the unsaturated monomer preferably includes a functional group-containing monomer. Details of preferred functional groups and functional group-containing monomers are as described above.
From such a viewpoint, the macromonomer is represented by the following general formula (4) as a structural unit derived from an unsaturated monomer different from the ethylenically unsaturated monomer:

It is preferable that at least the structural unit derived from the functional group-containing monomer represented by (the symbols in the formula are as described above).

More preferably, the macromonomer includes a group represented by the general formula (7) and a structural unit derived from the functional group-containing monomer represented by the general formula (4). Especially, it is preferable that the group represented by the general formula (7) includes a structure in which the structural unit represented by the general formula (4) is adjacent. The macromonomer containing such a structure has the following general formula (8):

(The symbols in the formula are as described above.) e represents the number of structural units represented by the general formula (4) with respect to one group represented by the general formula (7). The preferred range of e is the same as e in the general formula (5). By using a macromonomer having such a structure, the comb polymer of the present invention can be obtained more easily. Thus, the form in which the macromonomer is represented by the general formula (8) is one of the preferred forms of the present invention.

The macromonomer may also contain a component having a structure in which a constituent unit derived from an unsaturated monomer other than the functional group-containing monomer is adjacent to the group represented by the general formula (7). In this case, the component represented by the general formula (8) and the group represented by the general formula (7) have a structure in which a constituent unit derived from an unsaturated monomer other than the functional group-containing monomer is adjacent. The component represented by the general formula (8) is preferably 50% by mass or more with respect to 100% by mass as the total amount with the component. Thereby, various performances derived from the functional group are further exhibited. More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more, Most preferably, it is 100 mass%.
The unsaturated monomer other than the functional group-containing monomer is not particularly limited, and one or more kinds of any unsaturated monomer can be used.

<Preparation of macromonomer>
The method for obtaining the macromonomer is not particularly limited. For example, a technique obtained by reacting a functional group-containing monomer with a thiol compound having a mercapto group and an unsaturated site (also simply referred to as “thiol compound”) is preferable. Used. Specifically, for the synthesis of the macromonomer, the macromonomer can be efficiently synthesized by utilizing the difference in reactivity between the unsaturated site of the thiol compound and the mercapto group. As an example of a synthesis strategy, if a thiol compound can be reacted with a functional group-containing monomer that does not copolymerize with the unsaturated site of the thiol compound, chain transfer polymerization proceeds from the mercapto group of the thiol compound. As a result, the macromonomer in which the unsaturated site of the thiol compound remains and the polymer chain of the functional group-containing monomer is introduced can be synthesized with good yield.

-Functional group-containing monomer-
The functional group-containing monomer used in the reaction is as described above, but an unsaturated monomer other than the functional group-containing monomer may be used in combination with the functional group-containing monomer. For example, it is preferable that the ratio of the functional group-containing monomer is 50% by mass or more in the total amount of 100% by mass of all unsaturated monomers used in the above reaction. Thereby, various performances derived from the functional group are further exhibited. More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more, Most preferably, it is 100 mass%.
The unsaturated monomer other than the functional group-containing monomer is as described above.

-Thiol compound-
A thiol compound is a compound having a mercapto group and an unsaturated site. The unsaturated site is preferably derived from an ethylenically unsaturated monomer, more preferably represented by the general formula (6). Therefore, the thiol compound is particularly preferably a compound having a mercapto group and an unsaturated site represented by the general formula (6). Thereby, the unsaturated site is likely to remain in the generated macromonomer, and this unsaturated site is easily used for the subsequent reaction with the anionic group-containing monomer.

Specifically, when a functional group-containing monomer that is difficult to polymerize with the unsaturated site of the thiol compound is polymerized with the thiol compound, the functional group-containing monomer does not polymerize with the unsaturated site of the thiol compound. Chain transfer polymerization is started from the thiol site, and as a result, a macromonomer in which the unsaturated site of the thiol compound remains can be easily obtained.
Specifically, in the above general formula (6), R ¹ is particularly preferably a methyl group, and the unsaturated site represented by the general formula (6) is a methallyl group or a 3-methyl-3-butenyl group. Is particularly preferable. For example, when a methacrylic monomer is reacted as a functional group-containing monomer with a thiol compound having such an unsaturated site (preferably a polymerization reaction), the methacrylic monomer is It does not polymerize with a methallyl group or 3-methyl-3-butenyl group, but selectively reacts with a mercapto group to easily leave the methallyl group or 3-methyl-3-butenyl group in a macromonomer. it can. As a result, the resulting macromonomer is polymerized with an unsaturated group-containing monomer that can be polymerized with the unsaturated site (residual unsaturated site) of the macromonomer, thereby further improving the comb polymer of the present invention. Can get to.

In the thiol compound, the number of mercapto groups and unsaturated sites may be one or more. Especially, it is preferable that it is one each. More preferably, as the thiol compound, the following general formula (9):

(The symbols in the formula are the same as those in the general formulas (2) and (3)).

The method for obtaining the thiol compound is not particularly limited. For example, (i) a method of producing an ester compound of an alcohol compound having an unsaturated site (also simply referred to as “unsaturated alcohol”) and a mercapto group-containing carboxylic acid ( (Ii) a method of producing a disulfide bond-containing dicarboxylic acid and an unsaturated alcohol after dehydration condensation and then reducing the disulfide bond (also referred to as production method (ii)); . Especially, it is suitable to use manufacturing method (ii) from a viewpoint of improving reaction efficiency. In addition, each component used for reaction can use 1 type (s) or 2 or more types, respectively.
Below, the preferable form of manufacturing method (i) and (ii) is further demonstrated.

As unsaturated alcohol used by the said manufacturing method (i), following General formula (10):

Is preferred. Specifically, in addition to unsaturated alcohols having 1 to 13 carbon atoms such as (meth) allyl alcohol, crotyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol, these unsaturated compounds Alkylene oxide adducts are preferred.

Examples of the mercapto group-containing carboxylic acid include the following general formula (11):

(The symbols in the formula are the same as those in the general formula (3).) Are preferred. In general formula (11), it is preferable that c and d are both 1 as described above.

The mercapto group-containing carboxylic acid is not particularly limited as long as it is a compound having a mercapto group and a carboxyl group. For example, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoisobutyric acid, thiomalic acid , Mercaptostearic acid, mercaptoacetic acid, mercaptobutyric acid, mercaptooctanoic acid, mercaptobenzoic acid, mercaptonicotinic acid, cysteine, N-acetylcysteine, mercaptothiazole acetic acid and the like. Among these, 3-mercaptopropionic acid and thioglycolic acid are more preferable.

In the above production method (i), the esterification reaction between the unsaturated alcohol and the mercapto group-containing carboxylic acid may be carried out by an ordinary method and is not particularly limited.

The unsaturated alcohol (alcohol compound having an unsaturated site) used in the production method (ii) is as described above for the production method (i).

The disulfide bond-containing dicarboxylic acid is not particularly limited as long as it is a compound having a disulfide bond and two carboxyl groups. For example, the following general formula (12):

(The symbols in the formula are the same as those in the general formula (3). Note that c and d may be the same or different.) It is.
The method for obtaining the disulfide bond-containing dicarboxylic acid is preferably a method for obtaining the above-mentioned mercapto group-containing carboxylic acid by disulfide reaction. The disulfide reaction may be performed by a normal method and is not particularly limited.

In the above production method (ii), the dehydration condensation reaction between the disulfide bond-containing dicarboxylic acid and the unsaturated alcohol is not particularly limited as long as it is carried out by an ordinary method. For example, dehydration condensation in the absence of an acidic substance. It is preferred to carry out the reaction. Thereby, the production efficiency is remarkably improved, and the yield of the thiol compound can be remarkably increased. For example, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride or the like is preferably used as the dehydrating condensing agent, and in that case, dimethylaminopyridine is preferably used in combination as a catalyst.

In the said manufacturing method (ii), reduction of a disulfide bond is performed after the dehydration condensation reaction mentioned above. The reduction reaction may be performed by a normal method and is not particularly limited. However, as in the above-described dehydration condensation reaction, it is also preferable to perform the reduction reaction in the absence of an acidic substance. Thereby, the production efficiency is remarkably improved, and the yield of the thiol compound can be remarkably increased. For example, dithiothreitol or the like is preferably used as the reducing agent.

-Reaction between thiol compound and functional group-containing monomer-
The reaction between the thiol compound and the functional group-containing monomer is generated by radicals generated from the mercapto group of the thiol compound using heat, light, radiation, etc., or a polymerization initiator used separately as necessary. It is preferable that the radicals transferred to the mercapto group undergo chain addition, and the functional group-containing monomer successively undergoes an addition reaction via the sulfur atom, thereby forming a macromonomer.
In this reaction, an unsaturated monomer other than the functional group-containing monomer may be used in combination with the functional group-containing monomer as necessary.

What is necessary is just to set suitably the reaction molar ratio of the said thiol compound and a functional group containing monomer according to the performance and use which are calculated | required. For example, it is preferable to set the functional group-containing monomer to 1 to 300 moles with respect to 1 mole of the mercapto group that the thiol compound has. For example, in the obtained comb polymer, the larger the number, the better from the viewpoint of further improving the performance derived from the functional group. More preferably, it is 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Further, from the viewpoint of relatively improving the performance derived from the anionic group-containing monomer to be reacted in the future, 250 or less is preferable, and 200 or less is more preferable.

The reaction between the thiol compound and the functional group-containing monomer is preferably performed by a polymerization reaction. Especially, it is preferable to copolymerize the raw material component which contains a thiol compound and a functional group containing monomer at least using a polymerization initiator. More preferably, a radical polymerization initiator is used as the polymerization initiator.

The polymerization reaction can be performed by a usual method such as solution polymerization or bulk polymerization. Among these, it is preferable to perform solution polymerization.
The solution polymerization can be carried out batchwise or continuously. Examples of the solvent used here include water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n -Aromatic or aliphatic hydrocarbons such as hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; . Especially, it is preferable to use at least 1 sort (s) selected from the group which consists of water and a C1-C4 lower alcohol from a soluble viewpoint of a raw material component and the polymer (macromonomer) obtained.

When performing the said polymerization reaction by aqueous solution polymerization method, it is preferable to use 1 type (s) or 2 or more types of water-soluble polymerization initiators as a radical polymerization initiator. 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- A water-soluble azo initiator such as a cyclic azoamidine compound such as (2-imidazolin-2-yl) propane hydrochloride; an azonitrile compound such as 2-carbamoylazoisobutyronitrile; At this time, if necessary, alkali metal sulfite such as sodium bisulfite, metabisulfite, sodium hypophosphite, Fe (II) salt such as molle salt, hydroxymethanesulfinate sodium dihydrate, One or more accelerators such as hydroxylamine hydrochloride, thiourea, L-ascorbic acid (salt), and erythorbic acid (salt) can be used.

When performing solution polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester compound or ketone compound as a solvent, as a radical polymerization initiator, for example, benzoyl peroxide, lauroyl peroxide, sodium peroxide, etc. It is preferable to use a peroxide such as t-butyl hydroperoxide or cumene hydroperoxide; an azo compound such as azobisisobutyronitrile; At this time, an accelerator such as an amine compound can be used in combination.

When a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various radical polymerization initiators or a combination of radical polymerization initiators and accelerators.

Although the reaction temperature of the said polymerization reaction is not specifically limited, For example, it is preferable to set in the range of 30-100 degreeC, More preferably, it is 45-95 degreeC. Moreover, although reaction time (polymerization time) is not specifically limited, When the polymerization rate and productivity are considered, the range of 5 minutes-10 hours is preferable, for example, More preferably, it is 30 minutes-6 hours.

In the above polymerization reaction, a polymerization initiator, a thiol compound and an unsaturated monomer (unsaturated monomer is a functional group-containing monomer and an unsaturated group other than the functional group-containing monomer used as necessary. Is a general term for monomers.) The method of charging into the reaction vessel is not particularly limited, and the entire amount may be initially charged in the reactor, or the entire amount may be dropped into the reactor. The part may be initially charged and the rest may be dropped. However, most preferably, the total amount of the polymerization initiator, the thiol compound and the unsaturated monomer is dropped into the solvent initially charged in the reaction vessel. Thereby, a desired macromonomer can be obtained suitably.

The total amount of the thiol compound and unsaturated monomer used in the polymerization reaction is preferably in the range of 10 to 99% by mass relative to 100% by mass of the total amount of all raw materials including other raw materials and the polymerization solvent. is there. If the polymerization reaction is carried out within this range, the polymerization rate and productivity can be further increased. More preferably, it is 20-98 mass%, More preferably, it is 30-80 mass%.

As an example of the step of obtaining a macromonomer by the reaction of the thiol compound and the functional group-containing monomer, 2-methallyl-3-mercaptopropanoate is used as the thiol compound, and methoxypolyethylene glycol ( The case of using ethylene oxide (9 mol) methacrylate (PGM9E) is conceptually simplified and shown below (formula (A)). The PEG chain means a polyethylene glycol chain.
The unsaturated bond of 2-methallyl-3-mercaptopropanoate and the methacrylic double bond such as methoxypolyethylene glycol methacrylate are poorly polymerizable and hardly polymerize. A desired macromonomer can be obtained more efficiently by utilizing the difference in reactivity between the unsaturated bond of the thiol compound and the thiol group. Specifically, chain transfer polymerization with methacrylate starts from the thiol site of 2-methallyl-3-mercaptopropanoate, and a macromonomer in which the unsaturated bond of 2-methallyl-3-mercaptopropanoate remains is obtained. be able to.

<Reaction between macromonomer and anionic group-containing monomer>
The reaction between the macromonomer and the anionic group-containing monomer is a polymerization of the unsaturated site remaining in the macromonomer and the unsaturated double bond portion (C = C) in the anionic group-containing monomer. A reaction is preferred. Thereby, the comb polymer of the present invention having a branch part including a main chain and side chains and a trunk part can be obtained more easily. Furthermore, in order to efficiently obtain a comb polymer, it is necessary to select an anionic group-containing monomer having an unsaturated site and good polymerizability of the macromonomer. Specifically, when the unsaturated portion of the macromonomer is a methallyl group or a 3-methyl-3-butenyl group, an anionic group-containing monomer is an acrylic acid monomer from the viewpoint of good polymerizability. preferable.

The anionic group-containing monomer used in the reaction is as described above, but together with the anionic group-containing monomer, monomers other than the anionic group-containing monomer (other monomers) May be used in combination. For example, the proportion of the anionic group-containing monomer may be 50% by mass or more in the total amount of 100% by mass of the anionic group-containing monomer and the other monomer reacted with the macromonomer. Is preferred. Thereby, the dispersion performance derived from an anionic group is further exhibited. More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more, Most preferably, it is 100 mass%. In addition, in the obtained comb polymer, from the viewpoint of adsorption performance to inorganic particles, a structural unit derived from an anionic group-containing monomer and a structural unit (preferably an ethylenic non-functional group) serving as a trident branch point connected to a branch portion. The proportion of the structural unit derived from the anionic group-containing monomer to the total amount of 100% by mass of the structural unit derived from the saturated monomer and the structural unit derived from the other monomer is 1% by mass or more. Preferably, it is 3 mass% or more.
The other monomers are as described above.

What is necessary is just to set suitably the reaction molar ratio of the said macromonomer and an anionic group containing monomer according to the performance and use which are calculated | required. For example, in the obtained comb-shaped polymer, the abundance ratio (trunk portion / branch portion, mass ratio) of the trunk portion derived from the anionic group-containing monomer and the branch portion derived from the macromonomer is in the preferred range described above. It is preferable to set so that.

The reaction between the macromonomer and the anionic group-containing monomer is preferably performed by a polymerization reaction. Especially, it is preferable to copolymerize the monomer component which contains a macromonomer and an anionic group containing monomer at least using a polymerization initiator. More preferably, a radical polymerization initiator is used as the polymerization initiator.

The polymerization reaction can be performed by a usual method such as solution polymerization or bulk polymerization. Among them, it is preferable to perform solution polymerization, and preferable modes and the like regarding solution polymerization are as described above regarding the reaction between the thiol compound and the functional group-containing monomer. However, in order to make the obtained comb polymer high molecular weight, it is particularly preferable to use a solvent having a low chain transfer property, and the most preferable solvent is water. In consideration of the solubility of the macromonomer and the anionic group-containing monomer used in the solvent, it is preferable to select water or an organic solvent.

The reaction temperature and reaction time of the polymerization reaction are not particularly limited, but are preferably in the ranges described above for the reaction between the thiol compound and the functional group-containing monomer.

In the above polymerization reaction, the method for charging each monomer component and polymerization initiator into the reaction vessel is not particularly limited, and the entire amount may be initially charged in the reactor, or the entire amount may be dropped into the reactor. Alternatively, a part may be initially charged and the rest may be dropped. However, when there is a difference in reactivity between the monomer components, it is preferable to set the charging method in consideration thereof. Therefore, for example, it is particularly preferable that a part or the whole amount of the macromonomer is initially charged in the reaction vessel, and the whole amount of the polymerization initiator and the unsaturated monomer such as the anionic group-containing monomer is dropped. Thereby, a desired comb polymer can be obtained more efficiently and easily.

The amount of all monomer components used in the polymerization reaction is preferably in the range of 10 to 99% by mass with respect to 100% by mass of the total amount of all raw materials including other raw materials and the polymerization solvent. If the polymerization reaction is carried out within this range, the polymerization rate and productivity can be further increased. More preferably, it is 20-98 mass%, More preferably, it is 30-80 mass%.

As an example of the step of obtaining a comb polymer by the reaction of the macromonomer and the anionic group-containing monomer, the macromonomer obtained by the above formula (A) is used as the macromonomer, and the anionic group-containing monomer is acrylic. The case where the acid (AA) is used is conceptually simplified and shown below (formula (B)).
In addition, a comb polymer can be obtained with much better copolymerizability and yield by using an acrylic acid monomer having good copolymerizability with the methallyl double bond of the macromonomer.

[Preferred use]
The (poly) anionic comb polymer of the present invention is a novel polymer and can be used for various applications. Among them, in addition to cement, fine coal powder, etc., calcium carbonate, titanium oxide, iron oxide, zirconia oxide are used. It is particularly suitable for use as an additive (inorganic particle additive) added to inorganic particles such as metal oxides. In particular, since the comb polymer is excellent in the dispersibility of inorganic particles, it is preferably used for an inorganic particle dispersant, and more preferably for a cement dispersant. Thus, any form in which the (poly) anionic comb polymer is a cement admixture polymer, a cement dispersant polymer, an inorganic particle additive polymer, or an inorganic particle dispersant polymer is suitable for the present invention. It is a form. Also, a cement admixture containing the (poly) anionic comb polymer; a cement dispersant containing the (poly) anionic comb polymer; an inorganic particle additive containing the (poly) anionic comb polymer; Any of the poly) inorganic particle dispersants containing anionic comb polymers is a preferred form of the present invention.

Since the comb polymer has a desired functional group, it can exhibit various performances according to the functional group. Therefore, for example, clay-resistant agents (additives that suppress adsorption to clay and selectively adsorb to particles to be dispersed), early strength agents, condition improvers, air entrainers, drying shrinkage reducers, etc. It is also suitable. In particular, in addition to the dispersion performance, it is suitable for applications in which clay resistance, early strength development, state improvement characteristics, air entrainment, dry shrinkage reduction, and the like are simultaneously required.

[Cement composition]
The cement composition of the present invention contains the (poly) anionic comb polymer of the present invention described above, cement and water, but further contains aggregates (fine aggregate, coarse aggregate, etc.) as necessary. Is preferred. Each component can be used alone or in combination of two or more.

In the cement composition, the addition ratio of the comb polymer of the present invention is preferably set to be 0.01 to 10 parts by mass in terms of solid content with respect to 100 parts by mass of the total amount of cement. If the amount is less than 0.01 parts by mass, the performance may not be sufficient. On the other hand, if the amount exceeds 10 parts by mass, the effect is substantially peaked, which may be disadvantageous from the viewpoint of economy. More preferably, it is 0.02-8 mass parts, More preferably, it is 0.05-6 mass parts.

Examples of the cement include Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate resistance, and low alkali types thereof); various mixed cements (blast furnace cement, silica cement, fly ash cement); white Portland cement Alumina cement; Super fast-hardening cement (1 clinker fast-hardening cement, 2 clinker fast-hardening cement, magnesium phosphate cement); Grout cement; Oil well cement; Low heat generation cement (low heat generation type blast furnace cement, fly ash mixed low heat generation type blast furnace Cement, Belite high-contained cement); Ultra-high-strength cement; Cement-based solidification material; Eco-cement (cement produced from one or more of municipal waste incineration ash and sewage sludge incineration ash) Slag, fly ash, cinder ash, clinker Mesh, 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. As described above, the (poly) anionic comb polymer 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, water / cement ratio (mass ratio) = 0. It can be used in a low water / cement ratio region such as 15 to 0.5 (preferably 0.15 to 0.4), high strength concrete with a large unit cement amount and a small water / cement ratio, and a unit cement amount. It is effective for any poor blended concrete of 300 kg / m ³ or less.

The cement composition may contain one or more kinds of cement additives (materials) as shown below as required. Among these, it is particularly preferable that an oxyalkylene antifoaming agent or an AE agent is included (or used in combination). The proportion of these additives used is preferably 0.0001 to 10 parts by mass with respect to 100 parts by mass of the solid content of the (poly) anionic comb polymer of the present invention.

Examples of cement additives (materials) include water-soluble polymer substances, polymer emulsions, retarders, early strengtheners / accelerators, mineral oil-based antifoaming agents, fat-based antifoaming agents, fatty acid-based antifoaming agents, and fatty acids. Ester-based antifoaming agent, oxyalkylene-based antifoaming agent, alcohol-based antifoaming agent, amide-based antifoaming agent, phosphate ester-based antifoaming agent, metal soap-based antifoaming agent, silicone-based antifoaming agent, AE agent, etc. Surfactant, waterproofing agent, rust preventive agent, crack reducing agent, expansion material and the like can be mentioned, and it is preferable to use the same as those described in JP2012-131997A. Other cement additives (materials) include, for example, cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, coloring agents, fungicides, blast furnaces Examples include slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, and plaster.

The (poly) anionic comb polymer of the present invention has the above-described configuration, can easily have a structure corresponding to the required performance, and is excellent in dispersion performance. The inorganic particle additive, cement admixture, and cement composition containing this polymer are useful in various fields in addition to the civil engineering and construction fields.

1 is a ¹ H-NMR chart of a reaction product (thiol compound (1)) obtained in Synthesis Example 1. FIG. In Production Example A-1, is a ¹ H-NMR chart diagram of the mixture prior to reaction with PGM9E and thiol compound (1). Is a ¹ H-NMR chart diagram of the reaction product obtained in Production Example A-1 (macromonomer (1)). Is a ¹ H-NMR chart diagram of the reaction product obtained in Production Example B-1 (comb polymer (1)). In Production Example A-2, is a ¹ H-NMR chart diagram of the mixture prior to reaction with HEMA and thiol compound (1). Is a ¹ H-NMR chart diagram of the reaction product obtained in Production Example A-2 (Macromonomer (2)). Is a ¹ H-NMR chart diagram of the reaction product obtained in Production Example B-2 (comb polymer (2)). It is the figure which showed the evaluation result of the water reduction of Test Example 1, Comparative Test Example 1, and Comparative Test Example 2. It is the figure which showed the evaluation result of the adsorptivity to the clay of Test Example 2, Test Example 3, and Comparative Test Example 3.

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 (or part by weight)”, and “%” means “% by mass (or percent by weight)”.

In the following production examples and the like, the weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured as follows.
<Molecular weight measurement conditions and measurement method (LS-GPC analysis)>
Column used: Tosoh Corp., TSKguardcolumn α + TSKgel α-5000 + TSKgel α-4000 + TSKgel α-3000, each one connected.
Eluent used: Boric acid: 49.46 g and a solution prepared by mixing 2000 g of acetonitrile with a solution prepared by dissolving 16.00 g of NaOH in 7934.54 g of ion-exchanged water.
Detector: Viscotek's triple detector Model 302
Light scattering detector: right angle light scattering: 90 ° scattering angle, low angle light scattering: 7 ° scattering angle, cell capacity: 18 μL, wavelength: 670 nm
Standard sample: Polyethylene glycol SE-8 (Mw107000) manufactured by Tosoh Corporation is used, the device constant is determined with the dn / dC being 0.135 ml / g and the refractive index of the used eluent being 1.333.
Standard sample: 250 μL of the solution dissolved in the eluent so that the concentration of the measurement object becomes 0.2 vol% (volume%) Sample: The elution so that the concentration of the measurement object becomes 1.0 vol% 250 μL of the solution dissolved with the liquid injection flow rate: 0.8 ml / min
Column temperature: 40 ° C

In the following production examples and the like, the ¹ H-NMR chart of each compound was measured under the following conditions.
<NMR measurement conditions>
1. NMR measurement condition measuring apparatus for thiol compound: VNMRS600 manufactured by Varian
Observation frequency: 600 MHz
Measurement solvent: CD ₃ Cl
Measurement temperature: 25.0 ° C
Integration count: 8 times Chemical shift criteria: TMS (0.00 ppm)

2. Macromonomer NMR measurement condition measurement apparatus: VNMRS600 manufactured by Varian
Observation frequency: 600 MHz
Measurement solvent: CD ₃ Cl
Measurement temperature: 25.0 ° C
Integration count: 8 times Chemical shift criteria: TMS (0.00 ppm)

3. Comb polymer NMR measurement condition measuring device: VNMRS600 manufactured by Varian
Observation frequency: 600 MHz
Measuring solvent: CD ₃ CN
Measurement temperature: 25.0 ° C
Cumulative number: 8 times Chemical shift standard: CH ₃ CN (1.94 ppm)

In the evaluation of adsorptivity to clay, TOC was measured under the following measurement conditions.
<TOC measurement conditions>
Measuring device: Total organic carbon meter (SHIMADZU, TOC-L)
Measurement analysis software: TOC-ControlV Ver. 2.00
Detector: High sensitivity NDIR (Infrared gas analysis)
Carrier gas: High purity air (manufactured by Sumitomo Seika Co., Ltd., Air ZERO-F)
Flow rate: 150 ml / min Combustion tube Column temperature: 680 ° C
Calibration curve standard sample: adjusted to 100 ppm and 500 ppm potassium hydrogen phthalate Preparation method of calibration curve standard sample: 2.125 g of potassium hydrogen phthalate (special grade reagent) is weighed and ion-exchanged water is used in a 1 L measuring flask. In addition, a standard stock solution adjusted to 1000 mgC / L was diluted 2 times and a diluted solution 10 times was used as a preparation solution for 500 ppm and 100 ppm calibration curves.

Synthesis Example 1 (Preparation of thiol compound (1))
The thiol compound (1) (2-methallyl-3-mercaptopropanoate) was synthesized using mercaptopropionic acid disulfide as a starting material.
Specifically, first, mercaptopropionic acid disulfide (20 g, 95 mmol), methallyl alcohol (13.7 g, 209 mmol) and dimethylaminopyridine (4.7 g, 38 mmol) in dichloromethane solution (60 mL) at 10 ° C. Under a nitrogen atmosphere, dicyclohexylcarbodiimide (DCC) (43.2 g, 209 mmol) -dichloromethane solution (40 mL) was slowly added dropwise. Subsequently, after stirring at room temperature for 1 hour, the precipitated solid was removed by filtration. To the obtained filtrate, dichloromethane was added to adjust the total weight to 200 g, 18 g of triethylamine (TEA) was added, 18.6 g of dithiothreitol (DTT) was added, and the mixture was stirred at room temperature for about 1.5 hours. The reaction system was washed about twice with 0.1 M hydrochloric acid using a separatory funnel, the organic phase was recovered, and the solvent was removed using a vacuum line to obtain a pale yellow transparent liquid.
A ¹ H-NMR chart of this reaction product is shown in FIG. From this ¹ H-NMR chart, it was confirmed that the reaction product was a thiol compound (1) (2-methallyl-3-mercaptopropanoate) represented by the following formula (a).

Production Example A-1 (Production of Macromonomer (1))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen introduction tube and a reflux condenser, 68.75 g of isopropanol was charged and heated to 80 ° C. After maintaining at 80 ° C. for 30 minutes, 112.5 g of methoxypolyethylene glycol (ethylene oxide: 9 mol) methacrylate (PGM9E) represented by the following formula (b) and 7.2 g of the thiol compound (1) obtained in Synthesis Example 1 And 23.99 g of isopropanol were dropped into the reaction vessel over 4 hours, and at the same time, 2,2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd.) was added to 37.39 g of isopropanol. An aqueous solution in which 0.1125 g of “V-65” (hereinafter also referred to as “V-65”) was dissolved was dropped over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%.
When the obtained product (macromonomer (1)) was analyzed by LS-GPC, Mw = 9000, Mn = 5800, dispersity (= Mw / Mn) = 1.55, and the consumption rate of PGM9E was 81% , P pure (polymer pure) was 81%.

Here, it was confirmed by ¹ H-NMR that the double bond of the methallyl skeleton derived from the thiol compound (1) remained in the reaction product (macromonomer (1)). A ¹ H-NMR chart of the mixture before the reaction of PGM9E and the thiol compound (1) is shown in FIG. 2-1, and a ¹ H-NMR chart of the product after the reaction is shown in FIG. In both FIG. 2-1 and FIG. 2-2, since a peak (peak derived from the double bond of the methallyl skeleton) is observed in the vicinity of a chemical shift of 5 ppm, the methallyl derived from the thiol compound (1) is present in the reaction product. It was confirmed that the skeleton double bond (unsaturated site) remained.
Also from the ¹ H-NMR chart of Figure 2-2, the reaction product was confirmed to be macromonomer (1) represented by the following formula (c). In the formula (c), nc represents the average number of repeating structural units in parentheses, and R ^c represents a hydrogen atom, an initiator residue, a chain transfer agent residue, or the like.

Production Example B-1 (Production of Comb Polymer (1))
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen inlet tube and a reflux condenser was charged with 69.8 g of an isopropanol 48% solution of the macromonomer (1) obtained in Production Example A-1 at 80 ° C. The temperature was raised to. After maintaining at 80 ° C. for 30 minutes, a mixture of 6.431 g of acrylic acid and 5.635 g of ion exchange water was dropped into the reaction vessel over 1 hour, and at the same time, 2,2 ′ was added to 7.465 g of ion exchange water. -An aqueous solution in which 0.5332 g of azobis (2-methylpropionamidine) dihydrochloride ("V-50" manufactured by Wako Pure Chemical Industries, Ltd., hereinafter also referred to as "V-50") was dissolved was added dropwise over 1.5 hours. did. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain a comb polymer (1).
When the obtained polymer was analyzed by LS-GPC, Mw = 33000, Mn = 20000, dispersity (= Mw / Mn) = 1.65, the consumption rate of acrylic acid was 96%, and the macromonomer (1) The consumption rate was 64%, and P pure (polymer pure) was 75%.
A ¹ H-NMR chart of this reaction product (comb polymer (1)) is shown in FIG.

Production Example A-2 (Production of Macromonomer (2))
61.34 g of isopropanol was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen introduction tube and a reflux condenser, and the temperature was raised to 80 ° C. After maintaining at 80 ° C. for 30 minutes, a mixture of 112.5 g of 2-hydroxyethyl methacrylate (HEMA), 9.0 g of thiol compound (1) obtained in Synthesis Example 1 and 6.37 g of isopropanol was placed in the reaction vessel. At the same time, an aqueous solution in which 0.4294 g of V-65 was dissolved in 60.32 g of isopropanol was dropped over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%.
When the obtained product (macromonomer (2)) was analyzed by LS-GPC, Mw = 10200 and Mn = 5600.

Here, it was confirmed by ¹ H-NMR that the double bond of the methallyl skeleton derived from the thiol compound (1) remained in the reaction product (macromonomer (2)). A ¹ H-NMR chart of a mixture of HEMA and thiol compound (1) before the reaction is shown in FIG. 4-1, and a ¹ H-NMR chart of the product after the reaction is shown in FIG. In both FIG. 4-1 and FIG. 4-2, a peak (a peak derived from a double bond of a methallyl skeleton) is observed near a chemical shift of 7.25 ppm, so the reaction product is derived from the thiol compound (1). It was confirmed that the double bond (unsaturated site) of the methallyl skeleton remained.
Further, from the ¹ H-NMR chart of FIG. 4B, it was confirmed that the reaction product was a macromonomer (2) represented by the following formula (d). In the formula (d), nd represents the average number of repeating structural units in parentheses, and R ^d represents a hydrogen atom, an initiator residue, a chain transfer agent residue, or the like.

Production Example B-2 (Production of Comb Polymer (2))
After dropping 104.38 g of the macromonomer (2) isopropanol solution obtained in Production Example A-2 into 500 g of diethyl ether and collecting the precipitate by filtration, ion-exchanged water was added to make the total amount 83.56 g (obtained). The obtained product is referred to as “macromonomer (2) aqueous solution”).
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen introduction tube and a reflux condenser was charged with 83.56 g of the macromonomer (2) aqueous solution and heated to 80 ° C. After maintaining at 80 ° C. for 30 minutes, a mixture of 2.225 g of acrylic acid and 8.267 g of ion exchange water was dropped into the reaction vessel over 1 hour, and at the same time, V-50 was added to 9.150 g of ion exchange water. An aqueous solution in which 0.208 g was dissolved was dropped over 1.5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain a comb polymer (2).
When the obtained polymer was analyzed by LS-GPC, Mw = 49000 and Mn = 26400, the consumption rate of acrylic acid was 98.81%, and the consumption rate of macromonomer (2) was 74.28%.
FIG. 5 shows a ¹ H-NMR chart of this reaction product (comb polymer (2)).

Production Example A-3 (Preparation of macromonomer (3))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen introduction tube and a reflux condenser, 68.75 g of isopropanol was charged and heated to 80 ° C. After maintaining at 80 ° C. for 30 minutes, a mixture of 112.0 g of 2-hydroxyethyl methacrylate (HEMA), 9.0 g of the thiol compound (1) obtained in Synthesis Example 1 and 22.26 g of isopropanol was placed in the reaction vessel. At the same time, an aqueous solution in which 4.28 g of V-65 was dissolved in 63.77 g of isopropanol was dropped over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%.
When the obtained product (macromonomer (3)) was analyzed by LS-GPC, it was Mw = 28900 and Mn = 1900.

Production Example A-4 (Production of Macromonomer (4))
61.38 g of isopropanol was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen introduction tube and a reflux condenser, and the temperature was raised to 80 ° C. After maintaining at 80 ° C. for 30 minutes, a mixture of 100.0 g of 2-hydroxyethyl methacrylate (HEMA), 8.0 g of the thiol compound (1) obtained in Synthesis Example 1 and 19.87 g of isopropanol was placed in the reaction vessel. At the same time, an aqueous solution in which 3.82 g of V-65 was dissolved in 56.93 g of isopropanol was dropped over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%.
When the obtained product (macromonomer (4)) was analyzed by LS-GPC, it was Mw = 6980 and Mn = 4300.

Production Example B-3 (Production of Comb Polymer (3))
79.04 g of the macromonomer (2) isopropanol solution obtained in Production Example A-2 was added dropwise to 500 g of diethyl ether, and the precipitate was collected by filtration, and then ion-exchanged water was added to make the total amount 79.04 g (obtained). The obtained product is referred to as “macromonomer (2) aqueous solution”).
79.04 g of the macromonomer (2) aqueous solution was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen introduction tube and a reflux condenser, and the temperature was raised to 80 ° C. After maintaining at 80 ° C. for 30 minutes, a mixture of 3.138 g of acrylic acid and 9.825 g of ion exchange water was dropped into the reaction vessel over 1 hour, and at the same time, V-50 was added to 4.780 g of ion exchange water. An aqueous solution in which 0.3414 g was dissolved was dropped over 1.5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (weight% concentration of all monomer components with respect to all raw materials) was 40%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain a comb polymer (3).
When the obtained polymer was analyzed by LS-GPC, Mw = 197500, Mn = 50800, the consumption rate of acrylic acid was 99.24%, and the consumption rate of the macromonomer (2) was 95.61%.

Comparative production example 1
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping line, a nitrogen inlet tube and a reflux condenser was charged with 149.29 g of methallyl alcohol EO 150 mol adduct and 1.35 g of acrylic acid to a total weight of 287.70 g with water. The temperature was raised to 58 ° C. After adding 33.80 g of 2% aqueous hydrogen peroxide and maintaining the temperature at 58 ° C. for 30 minutes, a mixture of 597.16 g of methallyl alcohol EO 150 mol adduct and 729.86 g of water was dropped into the reaction vessel over 1 hour. At the same time, a mixture of 62.20 g of acrylic acid and 15.55 g of water was dropped into the reaction vessel over 3 hours, and 4.38 g of L-ascorbic acid, 4.96 g of mercaptopropionic acid and 64.40 g of water were added. Was added dropwise over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. The polymerization component concentration (weight percent concentration of all monomer components with respect to all raw materials) was 45%.
When the obtained product (Comparative Polymer 1) was analyzed by LS-GPC, Mw = 77300 and Mn = 28500.

<Water reduction evaluation>
Under the following test conditions, the water-reducing property (cement dispersibility) was evaluated using the comb polymer (2) as an additive (Test Example 1). For comparison, an example using lignin sulfonate (manufactured by Aldrich: average Mw 8000, average Mn 3000) as an additive (Comparative Test Example 1) and plain (only ion-exchanged water, no additive) (comparison) Test example 2) was also evaluated for water reduction. The results are shown in FIG.

-Test conditions-
To 500 g of cement (manufactured by Taiheiyo Cement, ordinary Portland cement), 250 g of ion-exchanged water containing additives (water / cement ratio (weight ratio) = 0.50) is added, and Hobart mortar mixer (manufactured by Hobart, model number N -50) and kneading at low speed for 30 seconds, and then 1350 g of ISO sand was added over 30 seconds. Thereafter, the mixture was kneaded at a medium speed for 30 seconds, allowed to stand for 1 minute and 30 seconds, and then kneaded at a medium speed for 1 minute to prepare a cement mortar.
The flow value after 5 and a half minutes from the water injection was measured using a mini slump cone.
In Test Example 1, the test was carried out with the amount of comb polymer used relative to the cement (solid content (nonvolatile content), weight%) being 0.2%. In Comparative Test Example 1, lignin sulfonate was used with respect to cement. The test was conducted with the use amount (solid content (non-volatile content) amount, weight%) of 0.2% and 0.4%.

<Evaluation of adsorptivity to clay>
Under the following test conditions, the comb polymer (2) or (3) was used as an additive to evaluate the adsorptivity to clay (Test Examples 2 and 3). For comparison, an example (Comparative Test Example 3) using Comparative Polymer 1 (copolymer of methallyl alcohol EO adduct and acrylic acid) obtained in Comparative Production Example 1 as an additive was also used for clay. The adsorptivity to was evaluated. The results are shown in FIG.

-Test conditions-
0.27 g of Kunigel V1 (manufactured by Kunimine Kogyo Co., Ltd.) is added to 27 g of cement soot filtrate containing additives (10 mM CaSO ₄ · 49 mM Na ₂ SO ₄ · 27 mM K ₂ SO ₄ in 0.13M KOH aqueous solution) After stirring for 10 minutes using a stirrer, the solution was filtered using a membrane filter (particle size: 4.5 μm) to remove clay. Then, the adsorption amount of the additive to the clay was calculated by measuring the carbon concentration before and after mixing with the clay using TOC (total organic carbon meter, manufactured by SHIMADZU, as described above).
In each test example, the test was performed with the addition amount of the polymer (addition amount of the polymer (solid content (nonvolatile content) amount, weight%) to the clay) being 0%, 25%, and 50%.

Claims (11)

A comb polymer having a trunk portion and a branch portion,
The trunk portion has an anionic group;
The branch portion includes a main chain and a side chain. 2. The (poly) anionic comb polymer according to claim 1, wherein the anionic group is at least one group selected from the group consisting of a carboxyl group, a sulfonic acid group, and a phosphoric acid group. 3. The (poly) anionic comb polymer according to claim 1, wherein the main chain of the branch part contains a structural unit derived from an ethylenically unsaturated monomer. The side chain of the said branch part contains the at least 1 sort (s) of functional group selected from the group which consists of a nonionic group, a cation group, an anion group, and a betaine group, The Claim 1 characterized by the above-mentioned. (Poly) anionic comb polymer. The (poly) anionic comb polymer is obtained by reacting a macromonomer containing an unsaturated site derived from an ethylenically unsaturated monomer with an anionic group-containing monomer. The (poly) anionic comb polymer according to any one of 1 to 4. The branch portion has the following general formula (3):

(In formula, X represents a C1-C8 hydrocarbon group. AO represents a C2-C8 oxyalkylene group. Y represents a C1-C5 hydrocarbon group. A Is a number of 0 or 1, b is a number of 0 to 200, c is a number of 0 or 1, and d is a number of 0 or 1. The (poly) anionic comb polymer according to any one of claims 1 to 5, comprising at least. The side chain of the branch part has the following general formula (4):

(Wherein R ⁵ , R ⁶ and R ⁷ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms. R ⁸ represents an arbitrary functional group). The (poly) anionic comb polymer according to claim 1, comprising at least a structural unit derived from a functional group-containing monomer. A method for producing the (poly) anionic comb polymer according to claim 1,
The production method includes a step of reacting a macromonomer containing an unsaturated site derived from an ethylenically unsaturated monomer with an anionic group-containing monomer (poly) anionic comb polymer Manufacturing method. A cement admixture comprising the (poly) anionic comb polymer according to any one of claims 1 to 7. An inorganic particle additive comprising the (poly) anionic comb polymer according to any one of claims 1 to 7. A cement composition comprising the (poly) anionic comb polymer according to claim 1, cement and water.

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