JP2010070687A - Thiol-modified monomer, method for producing the same and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a thiol-modified monomer which is very excellent in various performances, particularly dispersion performance and gives a component useful in various uses, such as a cement admixture; a method for producing the monomer; a (poly)alkylene glycol chain-containing thiol polymer obtained using the monomer; a dispersant and a cement admixture containing these; and a cement composition. <P>SOLUTION: The thiol-modified monomer has a structure represented by general formula (1) or (2), wherein at least one unit of the terminals of a (poly)alkylene glycol chain represented by (AO)n is a ≥3C oxyalkylene group or an organic residue represented by R<SP>1</SP>and/or R<SP>2</SP>has a tertiary or higher carbon atom at a carbonyl group side terminal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a thiol-modified monomer, a method for producing the same, and a use thereof. More specifically, a thiol-modified monomer useful for various uses such as a dispersant and a cement admixture, a production method thereof, a (poly) alkylene glycol chain-containing thiol polymer obtained by using the monomer, and a dispersant using these And a cement admixture, and a cement composition.

Mercapto groups (thiol groups, SH groups) have unique reactivity and are functional groups useful for organic synthesis. Therefore, thiol compounds having at least one mercapto group in the molecule are unique to the mercapto group. It is used for a wide variety of applications by utilizing its reactivity. For example, to expand the application field of (poly) alkylene glycol, which has been useful as a soft segment for applications such as adhesives and sealants, and for imparting flexibility to various polymers, A thiol-modified polyalkylene glycol obtained by introducing a mercapto group has attracted attention.

By the way, as an application field of (poly) alkylene glycol, in recent years, cement compositions, for example, cement paste in which water is added to cement, mortar in which cement paste is mixed with fine sand, coarse aggregate in mortar The use of cement admixtures added to concrete mixed with pebbles is being studied. Such a cement admixture is usually used as a water reducing agent or the like, and exerts the action of improving the strength and durability of the cured product by reducing the cement composition by increasing the fluidity of the cement composition. It is used for that purpose.

As conventional cement admixtures, naphthalene-based and polycarboxylic acid-based cement admixtures are known. For example, an unsaturated carboxylic acid monomer and an unsaturated polyalkylene glycol ether monomer are used together. A copolymer for cement admixture obtained by polymerization is disclosed (for example, see Patent Document 1). In this copolymer for cement admixture, the carboxyl group derived from the unsaturated carboxylic acid monomer becomes an adsorbing group that adsorbs to the cement particles, and the polyalkylene glycol derived from the unsaturated polyalkylene glycol ether monomer. The chain acts as a dispersing group for dispersing the cement particles, and the steric repulsion of the polyalkylene glycol chain makes it possible to provide a cement admixture that exhibits a certain degree of dispersion performance.
However, in order to further reduce the amount of cement admixture used, the development of a cement admixture that can exhibit even higher dispersion performance has been demanded.

Further, as a conventional thiol-modified product of (poly) alkylene glycol, for example, both thioester groups obtained by adding a thiocarboxylic acid to a polyether having a double bond at both ends or one end and then decomposing the resulting thioester group can be obtained. A polyether having a mercapto group at one end or one end (see, for example, Patent Document 2) or a compound having a mercapto group as a biodegradable water-soluble polymer used in a detergent builder is introduced into a polyether compound by an ester reaction. A polymer (for example, see Patent Document 3) obtained by subjecting a modified polyether compound to block or graft polymerization of a monoethylenically unsaturated monomer component is disclosed.
However, these polymers have not reached a level that can sufficiently exhibit the extremely high degree of cement dispersibility (water-reducing property) that has recently been demanded. Therefore, there has been room for devising to make the compound useful in more fields by making it suitable for use as a cement admixture. Moreover, there was room for the device for enabling such a useful compound to be manufactured more efficiently.
JP 2001-220417 A Japanese Patent Publication No. 7-13141 JP-A-7-109487

The present invention has been made in view of the above situation, and is excellent in various performances, in particular, hydrolysis resistance and dispersion performance, and can provide a thiol-modified monomer that can provide useful components for various uses such as dispersants and cement admixtures. It is an object of the present invention to provide a monomer, a production method thereof, a (poly) alkylene glycol chain-containing thiol polymer obtained by using the monomer, a dispersant and a cement admixture containing these, and a cement composition. Is.

The present inventors have made various studies on components used in obtaining a polymer having a (poly) alkylene glycol chain. As a result, the (poly) alkylene glycol chain and at least one mercapto group contain a carbonyl group. It has been found that the use of a thiol-modified monomer having a structure bonded via a polymer can provide a polymer capable of exhibiting a high degree of dispersion performance, and that the monomer itself can also exhibit excellent dispersion performance. In such a monomer, (a) at least one unit at the end of the (poly) alkylene glycol chain is an oxyalkylene group having 3 or more carbon atoms, or (b) a group containing a carbonyl group. If the carbonyl group has a tertiary or higher carbon atom at the carbonyl group side end, the monomer is provided with extremely excellent hydrolysis resistance and functions and effects derived from the structure of the monomer in various applications. It has been found that the above problems can be solved brilliantly. Further, as a method for obtaining such a thiol-modified monomer, if a production method including a step of esterifying a compound having a carboxyl group and a mercapto group in one molecule with (poly) alkylene glycol, It has been found that a high-molecular-weight thiol-modified monomer can be obtained efficiently at low cost, simply, with high purity.

Furthermore, it is obtained by polymerizing an unsaturated monomer component containing an unsaturated carboxylic acid monomer and / or an unsaturated polyalkylene glycol ether monomer in the presence of such a thiol-modified monomer (polyester). ) It has been found that the alkylene glycol chain-containing thiol polymer exhibits hydrolysis resistance due to the specific structure of the thiol-modified monomer and can stably exhibit high dispersion performance over a long period of time. Among them, it has been found that the cement dispersibility is particularly excellent, and if such a thiol-modified monomer or polymer is used as a cement admixture, the amount of the compound can be significantly reduced when preparing a cement composition. Therefore, it has been found that the present invention is extremely useful in the field of civil engineering and construction in which concrete is handled, and the present invention has been achieved.

That is, the present invention provides the following general formula (1) or (2):

(In the formula, R ¹ and R ² are the same or different and represent an organic residue. AO is the same or different and represents one or more of oxyalkylene groups having 2 to 18 carbon atoms. N Represents an average number of moles of an oxyalkylene group and is an integer of 1 to 1000. R ³ represents a hydrogen atom or an organic residue.) A thiol-modified monomer having a structure represented by: organic above (AO) represented by n (poly) at least one unit of the terminal of the alkylene glycol chain, or a number of 3 or more oxyalkylene group having a carbon or represented by R ¹ and / or R ² The residue is a thiol-modified monomer having a tertiary or higher carbon atom at the carbonyl group side terminal.

The present invention is also a method for producing the thiol-modified monomer, the method comprising the step of esterifying a (poly) alkylene glycol with a compound having a carboxyl group and a mercapto group in one molecule. It is also a manufacturing method of the thiol modified monomer containing.

In the present invention, an unsaturated monomer component containing an unsaturated carboxylic acid monomer and / or an unsaturated (poly) alkylene glycol monomer is polymerized in the presence of the thiol-modified monomer. It is also a (poly) alkylene glycol chain-containing thiol polymer obtained.
The present invention is also a dispersant and a cement admixture containing the thiol-modified monomer and / or the (poly) alkylene glycol chain-containing thiol polymer.
The present invention is also a cement composition comprising a cement and the thiol-modified monomer and / or the (poly) alkylene glycol chain-containing thiol polymer.
The present invention is described in detail below.

The thiol-modified monomer of the present invention has a structure represented by the general formula (1) or (2), but the thiol-modified monomer represented by the general formula (1) (dithiol-modified monomer). Body), the thiol group at one end (mercapto group) and the thiol group at the other end are held with a sufficient interatomic distance, making it difficult for the thiol group to approach within the molecule. Moreover, if it is the thiol modified monomer (monothiol modified body) represented by the said General formula (2), it will become difficult for a thiol group to approach between molecules.

In the above general formulas (1) and (2), R ¹ and R ² are the same or different and represent an organic residue, for example, a linear or branched alkylene group having 1 to 18 carbon atoms, a phenyl group, an alkyl group. Examples thereof include aromatic groups such as phenyl group, pyridinyl group, thiophene, pyrrole, furan, and thiazole. Among these, from the viewpoint of reactivity, it is preferably a group containing a hydrocarbon group having 1 to 8 carbon atoms, more preferably a group containing a hydrocarbon group having 1 to 6 carbon atoms, and still more preferably a carbon number. 1 to 6 hydrocarbon groups, particularly preferably a branched alkylene group having 1 to 6 carbon atoms or an aromatic group having 6 carbon atoms. Moreover, it is preferable that it is C2 or more from a viewpoint of hydrolysis resistance. Most preferred is a branched alkylene group having 2 to 6 carbon atoms or an aromatic group having 6 carbon atoms, for example, a divalent organic residue derived from mercaptoisobutyric acid or thiosalicylic acid.
Note that R ¹ and R ² may be partially substituted with a hydroxyl group, an amino group, a cyano group, a carbonyl group, a carboxyl group, a halogen group, a sulfonyl group, a nitro group, a formyl group, or the like.
It is also preferable that the end groups of R ¹ and R ² are hydrocarbon groups. In this case, the carbon atom in the organic residue represented by R ¹ and R ² is bonded to the carbon atom in the carbonyl group in the general formula (1).

As will be described later, when the thiol-modified monomer is esterified with (poly) alkylene glycol and a compound having a carboxyl group and a mercapto group in one molecule, R ¹ and R ² are And a mercaptocarboxylic acid residue (a divalent organic residue excluding a mercapto group and a carboxyl group).

In the general formula (2), R ³ represents a hydrogen atom or an organic residue, and the organic residue is more preferably a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include an aliphatic alkyl group having 1 to 20 carbon atoms, an alicyclic alkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and 2 to 20 carbon atoms. An alkynyl group, a C6-C20 aryl group, etc. are mentioned.
R ³ is also preferably a hydrophilic group from the viewpoint of dispersibility of cement particles, and specifically, is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. More preferably, they are a hydrogen atom or a C1-C5 alkyl group, More preferably, they are a hydrogen atom or a C1-C3 alkyl group.

In the above general formulas (1) and (2), AO is the same or different and represents one or more oxyalkylene groups having 2 to 18 carbon atoms, and is not particularly limited. When (AO) n is composed of two or more oxyalkylene groups, these oxyalkylene groups may be introduced in a block form or randomly.

The oxyalkylene group represented by AO may be an oxyalkylene group having 2 to 18 carbon atoms. For example, when blended in a cement admixture, the viewpoint of further improving the dispersibility and hydrophilicity of cement particles. Therefore, it is preferably a relatively short-chain oxyalkylene group having about 2 to 8 carbon atoms. More preferably, it is an oxyalkylene group having 2 to 4 carbon atoms, and more preferably a (poly) alkylene glycol chain mainly represented by (AO) n from an oxyalkylene group having 2 carbon atoms (oxyethylene group). Thus, the thiol-modified monomer of the present invention has higher hydrophilicity.
The term “mainly” as used herein refers to, for example, 50 mol of oxyethylene groups with respect to 100 mol% of all oxyalkylene groups (alkylene glycol units) constituting the (poly) alkylene glycol chain represented by (AO) n. % Or more is preferable. More preferably, it is 70 mol% or more, More preferably, it is 90 mol% or more.
Hereinafter, the (poly) alkylene glycol chain represented by (AO) n is also referred to as “(poly) alkylene glycol chain (1)”.

In the case of the (poly) alkylene glycol chain (1), for example, when a cement composition is produced by blending with a cement admixture, the chain has 3 carbon atoms from the viewpoint of reducing viscosity and stiffness. It is preferable to introduce the above oxyalkylene group. Thereby, a certain degree of hydrophobicity is imparted to the (poly) alkylene glycol chain (1), and a slight structure (network) can be provided to the cement particles.

In this case, the content ratio of the oxyalkylene group having 3 or more carbon atoms is 1 mol% or more with respect to 100 mol% of all oxyalkylene groups (alkylene glycol units) constituting the (poly) alkylene glycol chain (1). It is preferably 3 mol% or more, more preferably 5 mol% or more, and particularly preferably 7 mol% or more. Moreover, when the oxyalkylene group having 3 or more carbon atoms is introduced too much, the resulting monomer and the polymer using the polymer become too hydrophobic, for example, to sufficiently improve the dispersion performance of cement particles. Therefore, it is preferably 50 mol% or less, more preferably 30 mol% or less, still more preferably 20 mol% or less, and particularly preferably 10 mol% or less.

The oxyalkylene group having 3 or more carbon atoms is preferably an oxyalkylene group having 3 to 8 carbon atoms from the viewpoint of ease of introduction, affinity with cement particles, and the like. More preferred are oxypropylene groups having 3 carbon atoms and oxybutylene groups having 4 carbon atoms.
In addition, the oxyalkylene group having 3 or more carbon atoms may be introduced in a block form or may be introduced in a random form, but (a (poly) alkylene glycol chain comprising an oxyalkylene group having 2 or more carbon atoms). )-((Poly) alkylene glycol chain comprising an oxyalkylene group having 3 or more carbon atoms)-((poly) alkylene glycol chain comprising an oxyalkylene group having 2 or more carbon atoms). preferable. Thereby, higher dispersibility can be exhibited.

In the thiol-modified monomer, the average addition mole number n of the oxyalkylene group (the chain length of the (poly) alkylene glycol chain (1)) is a number of 1 to 1000, but when blended in a cement admixture. From the viewpoint of more effectively dispersing cement particles, the amount is preferably 10 mol or more. More preferably 20 moles or more, still more preferably 45 moles or more, still more preferably 70 moles or more, still more preferably 80 moles or more, still more preferably 90 moles or more, still more preferably 100 moles or more, even more preferably 110 moles or more, Especially preferably, it is 120 mol or more, Most preferably, it is 140 mol or more. Moreover, it is suitable that it is 500 mol or less. More preferably 400 mol or less, still more preferably 350 mol or less, still more preferably 300 mol or less, still more preferably 280 mol or less, still more preferably 250 mol or less, particularly preferably 220 mol or less, and most preferably 200 mol or less. is there.

In the thiol-modified monomer of the present invention, (a) at least one unit at the terminal of the (poly) alkylene glycol chain (1) is an oxyalkylene group having 3 or more carbon atoms, or (b) the above (A) of the form in which the organic residue represented by R ¹ and / or R ² in the general formula (1) or (2) has a tertiary or higher carbon atom at the carbonyl group side terminal Or it is suitable that it is one or more forms of (b).

The form (a) is a form in which at least one alkylene glycol unit of the terminal group of the (poly) alkylene glycol chain (1) is an oxyalkylene group having 3 or more carbon atoms. The oxyalkylene group having 3 or more carbon atoms is preferably, for example, an oxyalkylene group having 3 to 18 carbon atoms. Among them, an oxypropylene group, an oxybutylene group, an oxystyrene group, an alkyl glycidyl ether residue and the like are preferable. Is preferred. More preferred are an oxypropylene group and an oxybutylene group for ease of production.

The oxyalkylene group having 3 or more carbon atoms located at the terminal of the (poly) alkylene glycol chain (1) is preferably derived from a secondary alcohol residue. Among them, a tertiary or higher carbon atom derived from the secondary alcohol residue was bonded to one or both of the ester bonds in the structure represented by the general formula (1) or (2). The form is preferred. Thereby, further excellent hydrolysis resistance is imparted.
The ester bond in the structure represented by the general formula (1) or (2) is a group represented by “—R ¹ —COO—” in the general formulas (1) and (2). Ester bond (—COO—), or an ester bond (—COO) composed of a terminal oxygen atom represented by (AO) n and the “—OC—R ² —” site in the general formula (1) -) Means.

The introduction amount of the oxyalkylene group having 3 or more carbon atoms depends on the required degree of hydrolysis resistance, but when the number of both ends of the (poly) alkylene glycol chain (1) is 100 mol%, It is preferably at least mol%. More preferably, it is 100 mol% or more, More preferably, it is 150 mol% or more, Especially preferably, it is 200 mol% or more.

In the form of (b), the divalent organic residue represented by R ¹ and / or R ² is a carbonyl group (—CO—) side terminal in the general formula (1) or (2). The organic residue is preferably a branched alkylene group having 2 to 6 carbon atoms or an aromatic group having 6 carbon atoms. More preferably, it is a divalent organic residue derived from mercaptoisobutyric acid or thiosalicylic acid.
The “carbonyl group in the general formula (1) or (2)” herein refers to the “CO” group in the “—R ¹ —COO—” in the general formulas (1) and (2), and / or It means a “CO” group in “—OC—R ² —” in the general formula (1).

The particularly preferred form of the thiol-modified monomer of the present invention is one of the ester bonds in the structure represented by the above general formula (1) or (2) among the forms (a) and (b), or its Both are in the form of being bonded to tertiary or higher carbon atoms in at least one group selected from the group consisting of R ¹ , R ² , and (AO) n.
That is, it is represented by an ester bond (—COO—) in the “—R ¹ —COO—” moiety in the general formula (1) or (2) and (AO) n in the general formula (1). At least one of the ester bonds (—COO—) composed of the terminal oxygen atom and the “—OC—R ² —” site consists of R ¹ , R ² , and (AO) n. A form formed by bonding to tertiary or higher carbon atoms contained in at least one group selected from the group is preferred.
By specifying in such a form, hydrolysis resistance is further improved, and various functions and effects derived from the thiol-modified monomer of the present invention are further exhibited.

The thiol-modified monomer is also a (poly) alkylene glycol represented by (AO) n by appropriately adjusting R ¹ and / or R ² and n in the general formulas (1) and (2). It is preferable that the chain (1) occupies 50% by mass or more in 100% by mass of the thiol-modified monomer. Thereby, since the contribution rate of AO in the thiol-modified monomer is increased, the characteristics of the thiol-modified monomer of the present invention can be easily adjusted by appropriately selecting AO. More preferably, it is 80 mass% or more.

Here, the thiol group is easily oxidized to form a multimerized product particularly under alkaline conditions. Examples of the multimerized product include the following general formula (1 '):

(Wherein R ¹ , R ² , AO and n are the same as those in the general formula (1). R represents an integer of 2 or more) General formula (2 ′):

(Wherein, R ¹ , R ³ , AO and n are the same as those in the general formula (2)), and the like.

Therefore, it is preferable that an antioxidant is added to the thiol-modified monomer of the present invention in order to prevent the monomer from becoming too large.
As the antioxidant, a commonly used antioxidant may be used and is not particularly limited. For example, phenothiazine and derivatives thereof; hydroquinone, catechol, resorcinol, methoquinone, butylhydroquinone, butylcatechol, Phenolic compounds such as naphthohydroquinone, dibutylhydroxytoluene, butylhydroxyanisole, tocopherol, tocotrienol and catechin; nitro compounds such as tri-p-nitrophenylmethyl, diphenylpicrylhydrozine and picric acid; nitroso such as nitrosobenzene and cuperone Compound; Amine compound such as diphenylamine, di-p-fluorophenylamine, N- (3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide; TEMPO Stable radicals such as cal (2,2,6,6-tetramethylyl-1-piperidinyloxyl), diphenylpicrylhydrazyl, galvinoxyl, ferdazil; alcorbic acid, erythorbic acid and salts or esters thereof; dithiobenzoyl disulfide; copper chloride (II ); Thiols such as mercaptoethanol, dithiothreitol, glutathione; Tris (2-carboxyethyl) phosphine hydrochloride and the like. These may be used alone or in combination of two or more. Among them, phenothiazine and its derivatives, phenolic compounds, ascorbic acid, erythorbic acid and esters thereof are suitable compounds that can more effectively exhibit functions as radical scavengers and polymerization inhibitors, and phenothiazine, hydroquinone, and methoquinone are preferred. More preferred.

The amount of the antioxidant added is not particularly limited as long as it can effectively prevent an increase in the amount of the thiol-modified monomer. However, if the amount is too small, the effect is not exhibited. The performance may not be sufficient or coloring may occur. Therefore, with respect to the mass (solid content) of the thiol-modified monomer, the antioxidant is preferably 10 ppm or more by mass, more preferably 20 ppm or more, still more preferably 50 ppm or more, particularly preferably 100 ppm or more, Moreover, it is preferable that it is 5000 ppm or less, More preferably, it is 2000 ppm or less, More preferably, it is 1000 ppm or less, Most preferably, it is 500 ppm or less.

The thiol-modified monomer is obtained by esterifying a compound having an organic residue containing an alkylene glycol group with a compound having a carboxyl group or a hydroxyl group and a mercapto group in one molecule. Is preferred. More preferably, it is obtained by esterifying a compound having a carboxyl group and a mercapto group in one molecule with (poly) alkylene glycol, and a production method including such an esterification reaction step Is also one aspect of the present invention.

By the way, according to the 4th edition of Experimental Chemistry Course 24 (Maruzen Co., Ltd., p320-331) edited by the Chemical Society of Japan, the following three methods (i) to (iii) are mentioned as methods for synthesizing thiols. .
(I) A synthetic method using a substitution reaction between primary and secondary alkyl halides or sulfonic acid esters and various sulfurating agents.
(Ii) A method in which thioacetic acid and thiobenzoic acid are added to a double bond and then hydrolyzed to obtain a thiol (synthesis method using an addition reaction).
(Iii) A synthesis method using a reduction reaction such as disulfide.

However, if the thiol-modified monomer of the present invention is to be synthesized by the synthesis method of (i) above, the synthesis step is often reaction, purification, reduction, purification, and there are many expensive sulfurizing agents, Industrial implementation is very expensive. Further, as a raw material, a polyalkylene oxide compound having a substitutable functional group such as 1 to 2 halogen groups and a sulfonic acid ester group (hereinafter also simply referred to as “raw material compound 1”) is required. As in the present invention, it is very difficult to obtain the raw material compound 1 for obtaining a thiol-modified monomer having a relatively large molecular weight with a high purity, and the obtained thiol-modified monomer is purified to a desired purity. It is also very difficult.

If the thiol-modified monomer of the present invention is synthesized by the synthesis method (ii) above, a compound having a double bond such as an allyl group at both ends of polyalkylene glycol (hereinafter simply referred to as “raw compound 2”). It is also necessary to carry out alkali hydrolysis after adding thiocarboxylic acid such as thioacetic acid and thiobenzoic acid. However, in the synthesis method of (ii) above, thioacetic acid and thiobenzoic acid must be used in a large excess with respect to the double bond, such thioacetic acid and thiobenzoic acid are expensive, and thioacetic acid And thiobenzoic acid and its decomposition products have a strong odor, so special equipment is required for synthesis and purification. As a result, there is a problem that the cost for obtaining the thiol-modified monomer of the present invention becomes very high.

Further, if the thiol-modified monomer of the present invention is synthesized by the synthesis method of (iii) above, as in the synthesis method of (i) above, as a raw material, 1 to 2 halogen groups, sulfonate ester groups Although a polyalkylene oxide compound (raw material compound 1) having such a substitutable functional group is required, as described above, raw material compound 1 for obtaining a high molecular weight thiol-modified monomer is obtained as in the present invention.・ It is difficult to synthesize.

On the other hand, if the manufacturing method of the thiol modified monomer of this invention mentioned above is employ | adopted, a high molecular weight thiol modified monomer can be obtained simply and efficiently at low cost. Hereinafter, the method for producing the thiol-modified monomer of the present invention will be further described.
In the above method for producing a thiol-modified monomer, as a compound having an organic residue containing an alkylene glycol group (hereinafter also simply referred to as “alkylene glycol group-containing compound”), (poly) alkylene glycol, alkoxy (poly ) Alkylene glycol, aminoxy (poly) alkylene glycol, or a compound obtained by introducing a carboxyl group into (poly) alkylene glycol of these compounds. (Poly) alkylene glycol is preferred.

The (poly) alkylene glycol may be commercially available, or may be synthesized by reacting one or more alkylene oxides with water or alcohol.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, epichlorohydrin, and the like, and one or more of these can be used.
Examples of the alcohol include alcohols such as methanol, ethanol, butanol, ethylene glycol, propylene glycol, and butanediol, and one or more of these can be used.

What is necessary is just to perform reaction with the said alkylene oxide, water, or alcohol by a normal method, for example, the method as described in Unexamined-Japanese-Patent No. 2002-173593 is mentioned. Specifically, it is carried out by heating a mixed solution of an alkylene oxide and water or alcohol to 50 to 200 ° C. under pressure in the presence of a catalyst. At this time, the reaction may be performed after all the alkylene oxide is charged at one time, or the remaining alkylene oxide is continuously added or sequentially added to a reaction vessel in which water or alcohol and a part of the alkylene oxide are previously charged. A reaction may be performed.

As a compound in which a carboxyl group is introduced into the (poly) alkylene glycol, a compound in which a carboxyl group is introduced into a (poly) alkylene glycol (or alkoxy (poly) alkylene glycol or aminoxy (poly) alkylene glycol) by an ordinary method. Can be used. Examples of the introduction method include a method of oxidizing a hydroxyl group of (poly) alkylene glycol, a method of etherification with monochloroacetic acid, a method of esterification with polyvalent carboxylic acid, and the like.

In the above method for producing a thiol-modified monomer, a compound having a carboxyl group or a hydroxyl group and a mercapto group in one molecule (hereinafter also referred to as “thiol group-containing compound”) may be a mercapto in an alkylene glycol group-containing compound. The group is not particularly limited as long as it can introduce a group. For example, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoisobutyric acid, thiomalic acid, thiosalicylic acid, mercaptostearic acid Mercaptoacetic acid, mercaptobutyric acid, mercaptooctanoic acid, mercaptobenzoic acid, mercaptonicotinic acid, cysteine, N-acetylcysteine, mercaptothiazole acetic acid and other mercapto group-containing carboxylic acids (mercaptocarboxylic acid), mercaptoethanol, etc. The recited, may be used alone or in combination of two or more thereof. Among these, a compound having a carboxyl group and a mercapto group in one molecule, that is, mercaptocarboxylic acid is preferable, and thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, mercaptoisobutyric acid, and thiosalicylic acid are particularly preferable. .

Here, when the thiol-modified monomer of the present invention satisfies the above (a), for example, in the above-described method for producing a thiol-modified monomer, as the alkylene glycol group-containing compound, the above (poly) In alkylene glycol (or alkoxy (poly) alkylene glycol, aminoxy (poly) alkylene glycol, or (poly) alkylene glycol of a compound obtained by introducing a carboxyl group into (poly) alkylene glycol of these compounds), carbon number 3 It can manufacture by using the compound formed by adding the above alkylene oxide.
In addition, in order to increase the introduction rate of oxyalkylene groups having 3 or more carbon atoms (more preferably secondary alcohol residues) during the addition reaction, alkali metals, alkaline earth metals and oxides thereof are used as catalysts. Alternatively, it is preferable to use at least one compound selected from the group consisting of hydroxides. More preferred are sodium hydroxide, potassium hydroxide, magnesium hydroxide and calcium hydroxide, and most preferred are sodium hydroxide and potassium hydroxide.
The reaction temperature during the addition reaction is preferably 50 to 200 ° C. in order to increase the introduction rate of these groups. More preferably, it is 70-170 degreeC, More preferably, it is 90-150 degreeC, Most preferably, it is 100-130 degreeC.

Here, as described above, the particularly preferable form of the thiol-modified monomer of the form (a) is that at least one unit at the end of the (poly) alkylene glycol chain (1) is a secondary alcohol residue. An oxyalkylene group having 3 or more carbon atoms and a tertiary or higher carbon atom derived from the secondary alcohol residue, and a structure represented by the general formula (1) or (2) One or both of the ester bonds are bonded. Such a thiol-modified monomer uses one derived from a secondary alcohol residue as an alkylene oxide having 3 or more carbon atoms in the addition reaction, and used as a catalyst for hydroxylation of an alkali metal or alkaline earth metal. The product can be preferentially produced by reacting at a low temperature. The catalyst to be used is more preferably sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, and most preferably sodium hydroxide or potassium hydroxide. Moreover, it is preferable that reaction temperature is 50-200 degreeC. More preferably, it is 70-170 degreeC, More preferably, it is 90-150 degreeC, Most preferably, it is 100-130 degreeC.

Further, when the thiol-modified monomer satisfies the above (b), in the above-described method for producing a thiol-modified monomer of the present invention, as a thiol group-containing compound, a tertiary or higher group on the carboxyl group side. It can manufacture by using the mercapto carboxylic acid which has the following carbon atom. As such mercaptocarboxylic acid, for example, mercaptoisobutyric acid and thiosalicylic acid are suitable.

In the production method described above, the alkylene glycol group-containing compound and the thiol group-containing compound are subjected to an esterification reaction. The esterification reaction can be performed using a conventional method for an ester reaction in a normal liquid phase. it can. Further, for example, the pressure may be reduced or an entrainer such as xylene may be used. Moreover, you may carry out using acid catalysts, such as a sulfuric acid and paratoluenesulfonic acid, as needed.
The esterification reaction time may be appropriately designed according to the type and amount of the acid catalyst used, the mixing ratio of the alkylene glycol group-containing compound and the thiol group-containing compound, the solution concentration, and the like.

What is necessary is just to select the mixing ratio of the said alkylene glycol group containing compound and thiol group containing compound as follows according to the purity and cost of a desired thiol modified monomer, and a synthesis method.
(1) The hydroxyl group and carboxyl group derived from the thiol group-containing compound are largely excessive in molar ratio with respect to the functional group amount such as hydroxyl group and carboxyl group subjected to the reaction derived from the alkylene glycol group-containing compound. Specifically, from the viewpoint of reaction rate, the molar ratio is preferably 2 times or more, more preferably 3 times or more, and from the viewpoint of production cost, it is preferably 10 times or less, more preferably 5 times or less. By this method, a thiol-modified monomer can be obtained with high purity in a short time. The crude product after the reaction may be used as it is, but may be purified as necessary to remove unreacted products.

(2) The hydroxyl group or carboxyl group derived from the thiol group-containing compound is made to be twice or less in terms of molar ratio with respect to the functional group amount such as hydroxyl group or carboxyl group subjected to the reaction derived from the alkylene glycol group-containing compound. Specifically, from the viewpoint of yield, the molar ratio is preferably 0.3 times or more, more preferably 0.5 times or more, still more preferably 0.7 times or more, and further preferably 0.8 times or more. From the viewpoint of the remaining amount of unreacted material, it is preferably 1.8 times or less, more preferably 1.6 times or less, still more preferably 1.4 times or less, and still more preferably 1.3 times or less. The crude product after the reaction may be purified as necessary. However, in this method, since there are few unreacted thiol group-containing compounds, it is often possible to omit the operation of removing this, thereby further simplifying the production process. be able to.

Here, in the obtained thiol-modified monomer, when it is desired to increase the content of the thiol-modified monomer (monothiol-modified product) represented by the general formula (2), for example, an alkylene glycol group-containing compound The carboxyl group or hydroxyl group at one end of the above may be protected with an alkyl group or the like, and the thiol group-containing compound may be esterified to the carboxyl group or hydroxyl group at the other end. In addition, what is necessary is just to remove | eliminate protective groups, such as an alkyl group added to one terminal of an alkylene glycol group containing compound, as needed.

The method for producing a thiol-modified monomer may also include a step of adjusting the pH of the reaction solution after the esterification reaction, thereby sufficiently preventing the resulting ester from being hydrolyzed by the solvent removal step. Can be prevented. The pH can be adjusted by, for example, introducing an aqueous NaOH solution into the reaction solution obtained by the esterification reaction. In order to suppress the hydrolysis reaction, the pH of the reaction solution is preferably 3 or more, more preferably 4 or more. Moreover, it is preferable to set it as 8 or less, More preferably, it is 7 or less, More preferably, it is 6 or less, Especially preferably, it is 5.5 or less.

The reaction crude product (containing the thiol-modified monomer of the present invention) obtained by the esterification reaction is a reaction solution after the ester reaction (that is, a pH-unadjusted reaction solution) or after pH adjustment. It is preferable to solidify the reaction solution by cooling to room temperature. Thereby, the reaction crude product (containing the thiol-modified monomer) can be easily obtained from the reaction solution.
The solidified product of the obtained reaction crude product may be dried as it is and used as a thiol-modified monomer, but the obtained reaction crude product contains impurities such as an unreacted thiol group-containing compound, When it is necessary to remove these and purify the thiol-modified monomer of the present invention, for example, after drying and pulverizing the solidified product of the reaction crude product, impurities such as thiol group-containing compounds dissolve. The solidified product may be washed with a solvent that does not dissolve the thiol-modified monomer, such as diethyl ether.
In view of the increase in manufacturing cost due to the increase in the number of work steps and the environmental load due to the use of the solvent, it is preferable to avoid the cleaning work using the solvent. For this reason, as described above, the mixing ratio of the raw material compound, the alkylene glycol group-containing compound and the thiol group-containing compound, depends on the amount of functional groups such as hydroxyl groups and carboxyl groups used in the reaction derived from the alkylene glycol group-containing compound. On the other hand, it is preferable to carry out the hydroxyl group and carboxyl group derived from the thiol group-containing compound so that the molar ratio is 2 times or less. From the viewpoint of the remaining amount of unreacted material, it is preferably 1.8 times or less, more preferably 1.6 times or less, still more preferably 1.4 times or less, and still more preferably 1.3 times or less.

By the way, the present inventors dried the solidified product of the reaction crude product to obtain a dried solidified product, or washed the dried solidified product with diethyl ether or the like to further remove the thiol-modified single product from the reaction crude product. It has been found that the thiol-modified monomer may increase in quantity when obtaining a monomer. As a result of intensive studies, it has been found that the increase in the amount of the thiol-modified monomer is caused by drying the solidified product of the reaction crude product containing the thiol-modified monomer. For this reason, it is preferable to handle the solidified product of the reaction crude product so as not to dry, and it has been found that the production of the multimerized product can be effectively suppressed.

In the method for producing the thiol-modified monomer, it is preferable that the method further includes a step of adding an antioxidant, so that, for example, even when a solution in which the thiol-modified monomer is dissolved is heated. Thus, it is possible to sufficiently suppress the increase of the monomer. This is considered to be due to the following reason.
That is, the reaction of the raw material alkylene glycol group-containing compound and thiol group-containing compound usually requires heating. On the other hand, when the reaction mixture is heated, thermal radicals are generated from the thiol group of the thiol-modified monomer in the reaction mixture, and the increase in the number can occur. Thus, the addition of an antioxidant having radical scavenging ability effectively suppresses such increase in quantity.
The antioxidant may be added at any stage of production, for example, in the esterification reaction or when the reaction crude product is solidified.
Specific examples of the antioxidant and suitable compounds are as described above.
The addition amount of the antioxidant is not particularly limited as long as it can effectively prevent the thiol-modified monomer from being increased in number, and the content of the antioxidant in the thiol-modified monomer is within the above-described range. It is preferable to set so as to be.

As described above, the solidified product of the thiol-modified monomer tends to increase in quantity when dried. For this reason, the thiol-modified monomer of the present invention is preferably stored in a solution state, and is preferably stored in an aqueous solution at pH 4 or higher. More preferably, it is stored at pH 5 or higher, more preferably pH 6 or higher, and it is preferable to store at pH 7 or lower.

In the method for producing the thiol-modified monomer, the thiol-modified monomer is easily multimerized, and the thiol-modified monomer of the present invention includes a multimerized product. The process of removing may be included. Examples of methods for removing the multimerized product include molecular weight fractionation methods such as dialysis, ultrafiltration, and GPC fractionation.
In addition, since the addition of the step of removing the multimerized product leads to an increase in manufacturing cost, the thiol-modified monomer containing the multimerized product may be used as it is, for example, for the preparation of a polymer described later. .

The present invention also provides an unsaturated carboxylic acid monomer (hereinafter also referred to as “monomer (a)”) and / or an unsaturated (poly) alkylene glycol-based monomer in the presence of the thiol-modified monomer. It is also a (poly) alkylene glycol chain-containing thiol polymer obtained by polymerizing an unsaturated monomer component containing a monomer (hereinafter also referred to as “monomer (b)”).
Such a polymer includes a (poly) alkylene glycol chain ((poly) alkylene glycol chain (1)) derived from the thiol-modified monomer and a sulfur atom at least at one end of the (poly) alkylene glycol chain (1). It has a structure having a polymer portion containing a structural unit derived from an unsaturated monomer component bonded via a containing group, and can exhibit extremely high dispersion performance. In this case, for example, the following general formula (3) or (4):

(Wherein P ¹ , P ² and P ³ are the same or different and derived from an unsaturated monomer component containing an unsaturated carboxylic acid monomer and / or an unsaturated (poly) alkylene glycol monomer) R ¹ and R ² are the same or different and represent an organic residue, and AO is the same or different and represents one or two oxyalkylene groups having 2 to 18 carbon atoms. N represents an average number of moles of an oxyalkylene group and is an integer of 1 to 1000. R ³ represents a hydrogen atom or an organic residue. Preferably there is.

With regard to such a structure, for example, when using at least the unsaturated carboxylic acid monomer (a) as the unsaturated monomer component, at both ends or one end of the (poly) alkylene glycol chain (1) Since it has a carboxyl group derived from the monomer (a), it adheres to the cement particle via the carboxyl group and effectively disperses the cement particle by steric repulsion of the (poly) alkylene glycol chain (1). It is considered possible. Further, when at least the unsaturated (poly) alkylene glycol monomer (b) is used as the unsaturated monomer component, the single monomer is present at both ends or one end of the (poly) alkylene glycol chain (1). Since it has a (poly) alkylene glycol chain derived from the body (b) (hereinafter also referred to as “(poly) alkylene glycol chain (2)”), the (poly) alkylene glycol chain (1) has a (poly) ) The steric repulsion of the alkylene glycol chain (2) is added, and the synergistic effect is considered to improve the performance of dispersing cement particles.

In the unsaturated monomer component, as the unsaturated carboxylic acid monomer (a) (monomer (a)), for example, the following formula (5):

(In the formula, R ⁴ , R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom, a methyl group or (CH ₂ ) _x COOM ² (wherein — (CH ₂ ) _x COOM ² represents —COOM ¹ or The other — (CH ₂ ) _x COOM ² may form an anhydride.) _X is an integer of 0 to ^2. M ¹ and M ² are the same or different and represent a hydrogen atom. Represents a monovalent metal, divalent metal, trivalent metal, quaternary ammonium base or organic amine base).

Specific examples of the monomer (a) represented by the general formula (5) include monocarboxylic acid monomers such as acrylic acid, methacrylic acid, and crotonic acid; maleic acid, itaconic acid, and fumaric acid. Dicarboxylic acid monomers such as: anhydrides or salts of these carboxylic acids (for example, alkali metal salts, alkaline earth metal salts, trivalent metal salts, ammonium salts, organic amine salts) and the like. These monomers may be used alone or in combination of two or more. Among these monomers, acrylic acid, methacrylic acid, maleic acid, maleic anhydride and salts thereof are preferable from the viewpoint of polymerizability, and among them, acrylic acid, methacrylic acid and salts thereof are more preferable.

Examples of the unsaturated (poly) alkylene glycol monomer (b) (monomer (b)) include, for example, the following formula (6):

(.AO ^wherein, R 7, ^{R 8} and ^{R 9} are the same or different, ^{.R 10} represents a hydrogen atom or a methyl group, represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms are the same Or, differently, it represents one type or two or more types of oxyalkylene groups having 2 to 18 carbon atoms (wherein two or more types of oxyalkylene groups are introduced in a random manner even if they are introduced in a block shape). Y is an integer of 0 to 2. z is 0 or 1. p represents the average number of added moles of the oxyalkylene group and is an integer of 1 to 300. Are preferred.

In the general formula (6), R ¹⁰ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include, for example, a fatty acid having 1 to 20 carbon atoms. Group alkyl groups, alicyclic alkyl groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and the like.
R ¹⁰ is preferably a hydrophilic group from the viewpoint of dispersibility of the cement particles, and specifically, is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. More preferably, they are a hydrogen atom or a C1-C5 alkyl group, More preferably, they are a hydrogen atom or a C1-C3 alkyl group.

In the general formula (6), the (poly) alkylene glycol chain represented by-(AO) _p- corresponds to the above-mentioned (poly) alkylene glycol chain (2), but the oxyalkylene represented by AO. The group is preferably the same as the group constituting the (poly) alkylene glycol chain (1). In addition, from the viewpoint of effectively dispersing cement particles when blended in a cement admixture, it is preferable to have higher hydrophilicity, and mainly an oxyalkylene group having 2 carbon atoms (oxyethylene group). preferable. The content of the oxyethylene group in this case is as described above in the description of the (poly) alkylene glycol chain (1).
Similarly to the (poly) alkylene glycol chain (1), it is preferable to introduce an oxyalkylene group having 3 or more carbon atoms into the (poly) alkylene glycol chain (2). As described above.

P in the general formula (6) represents an average addition mole number of the oxyalkylene group (chain length of the (poly) alkylene glycol chain (2)) and is an integer of 1 to 300. Preferably it is 4 mol or more, More preferably, it is 10 mol or more, More preferably, it is 15 mol or more, More preferably, it is 20 mol or more, Most preferably, it is 25 mol or more, Most preferably, it is 30 mol or more. Further, it is preferably 250 mol or less, more preferably 200 mol or less, still more preferably 150 mol or less, still more preferably 125 mol or less, particularly preferably 100 mol or less, and most preferably 75 mol or less.

Specific examples of the monomer (b) represented by the general formula (6) include, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1 -Hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol and other saturated aliphatic alcohols having 1 to 20 carbon atoms, allyl alcohol, methallyl alcohol, crotyl alcohol, oleyl C3-C20 unsaturated aliphatic alcohols such as alcohol, C3-C20 alicyclic alcohols such as cyclohexanol, phenol, phenylmethanol (benzyl alcohol), methylphenol (cresol), p-ethyl Phenol, dimethylphenol (Renol), nonylphenol, dodecylphenol, phenylphenol, alkoxypolyalkylene glycols obtained by adding alkylene oxides having 2 to 18 carbon atoms to aromatic alcohols having 6 to 20 carbon atoms such as naphthol and the like , Esterified products of (meth) acrylic acid and crotonic acid; esterified products of polyalkylene glycols obtained by polymerizing alkylene oxides having 2 to 18 carbon atoms and (meth) acrylic acid and crotonic acid; These may be used alone or in combination of two or more. Of these unsaturated esters, esters of alkoxypolyalkylene glycols of (meth) acrylic acid are preferred.

Specific examples of the monomer (b) also include vinyl alcohol, allyl alcohol, methallyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol, and 3-methyl-2- Buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-2-buten-1-ol, 2-methyl-3-buten-1-ol, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, The compound which added 1-300 mol of alkylene oxides to unsaturated alcohols, such as hydroxybutyl vinyl ether, can be mentioned, These may be used independently or may use 2 or more types together. Of these unsaturated ethers, compounds using (meth) allyl alcohol and 3-methyl-3-buten-1-ol are preferred.
In the unsaturated esters and unsaturated ethers, the alkylene oxide is, for example, one or two selected from alkylene oxides having 2 to 18 carbon atoms such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. It is preferable to use the above alkylene oxide. When adding 2 or more types of alkylene oxide, any of random addition, block addition, alternate addition, etc. may be sufficient.

As the unsaturated monomer component, in addition to the monomer (a) and / or the monomer (b), a copolymerizable monomer (hereinafter referred to as “monomer (c)”). May be included). As said monomer (c), the following 1 type (s) or 2 or more types can be used.
Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid, and alkyl alcohols having 1 to 20 carbon atoms, glycols having 2 to 18 carbon atoms, or polyalkylene glycols having 2 to 300 moles of addition of these glycols Or monoesters and diesters of an alkylene oxide having 2 to 300 addition moles of an alkylene oxide obtained by adding an alkylene oxide having 2 to 18 carbon atoms to an alkyl alcohol having 1 to 20 carbon atoms;
Single-terminal aminated product of the above unsaturated dicarboxylic acids, alkylamines having 1 to 20 carbon atoms and glycols having 2 to 18 carbon atoms, or single-terminal aminated products of polyalkylene glycols having 2 to 300 addition moles of these glycols Monoamides and diamides with

Unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and the like, an alkyl alcohol having 1 to 20 carbon atoms, a glycol having 2 to 18 carbon atoms, or a polyalkylene glycol having 2 to 300 addition moles of these glycols, or An ester of an alkylene oxide having 2 to 300 addition moles of an alkylene oxide obtained by adding an alkylene oxide having 2 to 18 carbon atoms to an alkyl alcohol having 1 to 20 carbon atoms;
One-terminal aminated product of the above unsaturated monocarboxylic acid, alkylamine having 1 to 20 carbon atoms and glycol having 2 to 18 carbon atoms, or one-terminal amino acid of polyalkylene glycol having 2 to 300 addition moles of these glycols Amides with compounds;

Unsaturated sulfonic acids such as sulfoethyl acrylate, sulfoethyl methacrylate, 2-methylpropanesulfonic acid acrylamide, 2-methylpropanesulfonic acid methacrylamide, and styrenesulfonic acid, and monovalent metal salts, divalent metal salts, and ammonium thereof Salts and organic amine salts;
Unsaturated amides such as acrylamide, methacrylamide, acrylic alkylamide, methacrylalkylamide;
Unsaturated amino compounds such as dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate;
Vinyl esters such as vinyl acetate and vinyl propionate;
Vinyl ethers such as alkyl vinyl ethers having 3 to 20 carbon atoms such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether;
Aromatic vinyls such as styrene; etc.

As a mass ratio (mass ratio of (a) / (b) / (c)) of the monomer (a), the monomer (b) and the monomer (c) in the unsaturated monomer component, When the monomer (a) is the main component, it is preferably 50 to 99/50 to 1/0 to 40, more preferably 55 to 95/45 to 5/0 to 40, and still more preferably. It is 60-90 / 40-10 / 0-40, Most preferably, it is 65-85 / 35-15 / 0-40. Moreover, when a monomer (b) is a main component, it is preferable that it is 1-50 / 99-50 / 0-40, More preferably, it is 2-40 / 98-60 / 0-40, Furthermore, Preferably it is 5-30 / 95-70 / 0-40, Most preferably, it is 7.5-25 / 92.5-75 / 0-40.
is there.

The relationship between the thiol-modified monomer and the amount of monomer (a), monomer (b) and monomer (c) used is (monomer (a) + monomer (b) + When the sum of the monomers (c)) is taken as 100%, the ratio of the thiol-modified monomer (unit: mass%), when the monomer (a) is the main component, It is preferable that it is 50-99, More preferably, it is 55-95, More preferably, it is 60-90, Most preferably, it is 65-85. Moreover, when monomer (b) is a main component, it is preferable that it is 0.5-50, More preferably, it is 1-45, More preferably, it is 2-40, More preferably, it is 3-35, Especially preferably, it is 4-30, Most preferably, it is 5-25.

The polymerization reaction is carried out in the presence of the above-described thiol-modified monomer of the present invention. By using the monomer, the (poly) alkylene glycol chain (1) (above In general formula (1) or (2), a moiety represented by-(AO) n-) is introduced.
Here, the relationship between the amount of the (poly) alkylene glycol chain (1) and the amounts used of the monomer (a), the monomer (b) and the monomer (c) is (monomer (a ) + Monomer (b) + monomer (c)) as a ratio (unit: mass%) of the (poly) alkylene glycol chain (1) when the sum is 100%. When a) is a main component, it is preferably 50 to 99, more preferably 55 to 95, still more preferably 60 to 90, and particularly preferably 65 to 85. Moreover, when monomer (b) is a main component, it is preferable that it is 0.5-50, More preferably, it is 1-45, More preferably, it is 2-40, More preferably, it is 3-35, Especially preferably, it is 4-30, Most preferably, it is 5-25.

By using the thiol-modified monomer in the polymerization reaction, generated by radicals generated from thiol groups (mercapto groups) using heat, light, radiation, etc., or separately used polymerization initiators as needed The resulting radical chain-transfers to the thiol group or cleaves the disulfide bond to form a sulfur atom (sulfur atom-containing group) at one or both ends of the (poly) alkylene glycol chain (1) comprising the oxyalkylene group. Through this, monomers are successively added to form a polymer.

In this case, the carboxyl group derived from the monomer (a) via a sulfur atom (sulfur atom-containing group) at one or both ends of the (poly) alkylene glycol chain (1) composed of n oxyalkylene groups In the case of using a structural unit having a structural unit having a (poly) alkylene glycol chain (2) composed of p oxyalkylene groups derived from the monomer (b) and a monomer (c) A polymer having a structural unit derived from the monomer (c) is mainly produced. In addition, a polymer in which the structure of the polymer is repeated twice or more, a structural unit having a carboxyl group derived from the monomer (a), and p number of units derived from the monomer (b) A polymer having a structural unit having a (poly) alkylene glycol chain (2) composed of an oxyalkylene group and a structural unit derived from the monomer (c) when the monomer (c) is used is a secondary polymer. Then generate. Furthermore, a polymer of the monomer (a) and the monomer (b) or a polymer of the monomer (a), the monomer (b) and the monomer (c) may be generated. is there.

In the polymerization reaction, in addition to the thiol-modified monomer, a commonly used radical polymerization initiator may be used in combination. Any known radical polymerization initiator can be used as the radical polymerization initiator.
The amount of the polymerization initiator used may be appropriately adjusted according to the type and amount of the thiol-modified monomer, and is not particularly limited, but for the monomer with which the radical polymerization initiator is polymerized. If the amount is too small, the radical concentration is too low and the polymerization reaction is slowed.On the other hand, if the amount is too large, the radical concentration is too high and the polymerization from the monomer has priority over the polymerization from mercapto groups and disulfide bonds. There is a possibility that the yield of is not sufficient. Therefore, the amount of radical polymerization initiator used is preferably 0.001 mol% or more, more preferably 0.01 mol% or more, and still more preferably 0.1 mol% with respect to 100 mol% of the unsaturated monomer component. It is preferably at least 0.2 mol%, more preferably at most 10 mol%, more preferably at most 5 mol%, further preferably at most 2 mol%, particularly preferably at most 1 mol%. .

In the above polymerization reaction, when solution polymerization is performed using water as a solvent, it is not necessary to remove insoluble components after the polymerization, and therefore it is preferable to use a water-soluble 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) dihydrochloride, 2,2′-azobis [ Cyclic azoamidine compounds such as 2- (2-imidazolin-2-yl) propane] dihydrochloride, azonitrile compounds such as 2- (carbamoylazo) isobutyronitrile, 2,4′-azobis {2-methyl-N— Water-soluble azo initiation such as azoamide compounds such as [2- (1-hydroxybutyl)] propionamide}, macroazo compounds such as esters of 4,4′-azobis (4-cyanovaleric acid) and (alkoxy) polyethylene glycol Agents; etc. are used. These polymerization initiators may be used alone or in combination of two or more. Of these polymerization initiators, water-soluble azo initiators that easily generate radicals from mercapto groups or disulfide bonds are preferred.

At this time, Fe (II) salts such as alkali metal sulfites such as sodium hydrogen sulfite, metabisulfites, sodium hypophosphite, and molle salts, sodium hydroxymethanesulfinate dihydrate, hydroxylamine hydrochloride, thio An accelerator (reducing agent) such as urea, L-ascorbic acid or a salt thereof, erythorbic acid or a salt or ester thereof may be used in combination. These accelerators (reducing agents) may be used alone or in combination of two or more. In particular, a combination of hydrogen peroxide and an organic reducing agent is preferable. As the organic reducing agent, L-ascorbic acid or a salt thereof, L-ascorbic acid ester, erythorbic acid or a salt thereof, erythorbic acid ester, or the like is preferable. is there. The amount of the accelerator (reducing agent) used is not particularly limited. For example, it is preferably 10 mol% or more, more preferably 20 mol%, relative to 100 mol% of the polymerization initiator used in combination. More preferably, it is 50 mol% or more, preferably 1000 mol% or less, more preferably 500 mol% or less, still more preferably 400 mol% or less.

In the above polymerization reaction, when performing solution polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester or ketone as a solvent, or when performing bulk polymerization, benzoyl peroxide, lauroyl peroxide Peroxides such as oxide and sodium peroxide; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azonitrile compounds such as azobisisobutyronitrile; 2,2′-azobis (N-butyl-2- Azoamide compounds such as methylpropionamide), cyclic azoamidine compounds such as 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 4,4′-azobis (4-cyanovaleric acid) ) Compounds such as 4,4′-azobis (4-cyanovaleric acid) and (alkoxy) Macroazo compound such esters of polyethylene glycol; and the like are used as a radical polymerization initiator. These polymerization initiators may be used alone or in combination of two or more. Of these polymerization initiators, azo initiators that easily generate radicals from mercapto groups or disulfide bonds are preferred.

In this case, an accelerator such as an amine compound can be used in combination. The amount of the accelerator used is not particularly limited. For example, it is preferably 10 mol% or more, more preferably 20 mol% or more, and still more preferably with respect to 100 mol% of the polymerization initiator used in combination. It is 50 mol% or more, preferably 1000 mol% or less, more preferably 500 mol% or less, and still more preferably 400 mol% or less.

In the polymerization reaction, when a mixed solvent of water and lower alcohol is used, it can be appropriately selected from the radical polymerization initiator or a combination of the radical polymerization initiator and an accelerator.

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

A hydrophobic chain transfer agent can also be used as the chain transfer agent. Examples of the hydrophobic chain transfer agent include 3 or more carbon atoms such as butanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, octadecanethiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, octyl 3-mercaptopropionate, etc. It is preferable to use a thiol chain transfer agent having a hydrocarbon group.
In addition, as said chain transfer agent, 1 type (s) or 2 or more types can be used, and you may use combining a hydrophilic chain transfer agent and a hydrophobic chain transfer agent.

The amount of the chain transfer agent used may be appropriately adjusted according to the type and amount of the thiol-modified monomer, and is not particularly limited, but the total number of moles of unsaturated monomer components is 100 mol%. Is preferably 0.1 mol% or more, more preferably 0.25 mol% or more, still more preferably 0.5 mol% or more, and preferably 20 mol% or less, more preferably 15 mol%. Hereinafter, it is more preferably 10 mol% or less.

The polymerization reaction can be performed by a method such as solution polymerization or bulk polymerization. The solution polymerization can be performed batchwise, continuously, or a combination of two or more thereof. Examples of the solvent used as necessary during the polymerization include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; aromatics such as benzene, toluene, xylene, cyclohexane, and n-hexane; Aliphatic hydrocarbons; Esters such as ethyl acetate; Ketones such as acetone and methyl ethyl ketone; Cyclic ethers such as tetrahydrofuran and dioxane; These may be used alone or in combination of two or more.

In the above polymerization reaction, the polymerization temperature may be appropriately set according to the type of solvent and polymerization initiator used, and is not particularly limited, but is preferably 0 ° C. or higher, more preferably 30 ° C. or higher, further Preferably it is 50 degreeC or more, More preferably, it is 70 degreeC or more, Preferably it is 150 degrees C or less, More preferably, it is 120 degrees C or less, More preferably, it is 100 degrees C or less, More preferably, it is 90 degrees C or less.
Further, the method for adding the unsaturated monomer component to the reaction vessel is not particularly limited. For example, a method in which the entire amount is initially charged into the reaction vessel at once; a method in which the entire amount is divided or continuously charged into the reaction vessel; The method may be any of the methods of initially charging the reaction vessel and dividing or continuously charging the remainder into the reaction vessel. Moreover, the radical polymerization initiator and the chain transfer agent may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or may be combined in accordance with the purpose.

In the above polymerization reaction, in order to obtain a copolymer having a predetermined molecular weight with good reproducibility, it is necessary to allow the polymerization reaction to proceed stably. Therefore, in the case of solution polymerization, the solvent used is dissolved at 25 ° C. The oxygen concentration is preferably in the range of 5 ppm or less. More preferably, it is 4 ppm or less, More preferably, it is 2 ppm or less, Most preferably, it is 1 ppm or less. In addition, when nitrogen substitution etc. are performed after adding a monomer to a solvent, it is preferable to make the dissolved oxygen concentration of the system | strain containing a monomer into the said range.

The adjustment of the dissolved oxygen concentration of the solvent may be performed in a polymerization reaction tank, or a solution in which the amount of dissolved oxygen is adjusted in advance may be used. For example, the following (1) ) To (5).
(1) After pressurizing and filling an inert gas such as nitrogen into a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. You may reduce the pressure in an airtight container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

The polymer obtained by the above polymerization reaction is preferably adjusted to a pH range of weak acid or higher in an aqueous solution state from the viewpoint of handleability. More preferably, it is pH 4 or more, more preferably pH 5 or more, and particularly preferably pH 5.5 or more. On the other hand, the polymerization reaction may be performed under conditions where the pH exceeds 7, but in that case, the polymerization rate is lowered, and at the same time, the polymerization property is not sufficient and the dispersion performance is lowered. The copolymerization reaction is preferably performed in the pH range. More preferably, the pH is 7 or less. Thus, preferable polymerization initiators that cause the polymerization system to have a pH of 7 or less include water-soluble compounds such as persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate, and azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride. It is preferable to use an azo initiator, hydrogen peroxide, or a combination of hydrogen peroxide and an organic reducing agent.
Therefore, it is preferable to adjust to a higher pH by adding an alkaline substance after the polymerization reaction at a low pH.

As a preferred embodiment, specifically, a method of adjusting the pH to 6 or more by adding an alkaline substance after carrying out the copolymerization reaction at a pH of less than 6; adding an alkaline substance after carrying out the copolymerization reaction at a pH of less than 5 Examples include a method of adjusting the pH to 5 or higher; a method of adjusting the pH to 6 or higher by adding an alkaline substance after performing a copolymerization reaction at a pH lower than 5. The pH can be adjusted using, for example, an inorganic salt such as a monovalent metal or divalent metal hydroxide or carbonate; ammonia; an alkaline substance such as an organic amine. When pH needs to be lowered, particularly when pH adjustment is required during polymerization, for example, phosphoric acid, sulfuric acid, nitric acid, alkyl phosphoric acid, alkyl sulfuric acid, alkylsulfonic acid, (alkyl) benzenesulfone The pH can be adjusted using an acidic substance such as an acid, and among these acidic substances, phosphoric acid is preferred from the viewpoint of having a pH buffering action. Further, after the reaction is completed, the concentration can be adjusted if necessary.

The molecular weight of the polymer obtained by the polymerization reaction is preferably 10,000 or more in terms of weight average molecular weight, more preferably 20,000 or more, further preferably 30000 or more, and particularly preferably 40000 or more. Moreover, it is preferable that it is 300000 or less, More preferably, it is 200000 or less, More preferably, it is 150,000 or less, Most preferably, it is 100000 or less.
In addition, a weight average molecular weight can be measured by the method as described in the Example mentioned later.

The polymer obtained by the above polymerization reaction may be subjected to a process of isolating individual polymers as necessary, but from the viewpoint of work efficiency, production cost, etc., individual polymers are isolated. For example, it can be used for various applications such as a dispersant (particularly a cement admixture).
In addition, the dispersant containing the thiol-modified monomer and / or the (poly) alkylene glycol chain-containing thiol polymer and the cement admixture are also included in the present invention.
Hereinafter, a cement admixture will be described as a typical dispersant.

In the cement admixture of the present invention, the blending amount of the (poly) alkylene glycol chain-containing thiol polymer may be appropriately adjusted according to the desired dispersion performance. It is suitable that it is 50 mass% or more with respect to the total mass of 100 mass%. More preferably, it is 60 mass% or more, More preferably, it is 70 mass% or more, Most preferably, it is 80 mass% or more.
You may mix | blend a polycarboxylic acid type polymer with the said cement admixture other than the said polymer as needed. At that time, the blending amount is preferably the ratio of the polymer / polycarboxylic acid polymer (unit: mass%) of 90/10 to 10/90. More preferably, it is 80 / 20-20 / 80, More preferably, it is 70 / 30-30 / 70, Most preferably, it is 60 / 40-40 / 60.

When the cement admixture contains a monomer component, the content of the thiol-modified monomer is, for example, 50% by mass or more with respect to 100% by mass of the total mass of the cement admixture in terms of solid content. It is preferable that More preferably, it is 60 mass% or more, More preferably, it is 70 mass% or more, Most preferably, it is 80 mass% or more.
Also in this case, a polycarboxylic acid polymer may be blended. At that time, the blending amount is preferably 90/10 to 10/90 in the ratio of thiol-modified monomer / polycarboxylic acid polymer (unit: mass%). More preferably, it is 80 / 20-20 / 80, More preferably, it is 70 / 30-30 / 70, Most preferably, it is 60 / 40-40 / 60.
In addition, when the cement admixture includes the polymer and the thiol-modified monomer, the content thereof is preferably in the above-described range as the total amount thereof, and the polycarboxylic acid polymer and It is preferable that the blending amount of these is also in the above-described range as the total amount thereof.

The cement admixture also includes an antifoaming agent (such as (poly) oxyethylene (poly) oxypropylene adduct or diethylene glycol heptyl ether) or a polyalkyleneimine (such as ethyleneimine or propyleneimine) as necessary. A polyalkyleneimine alkylene oxide adduct can be blended.

The cement admixture may further contain one or more conventionally known cement admixtures. The conventionally known cement admixture is preferably a conventionally known polycarboxylic acid admixture and a sulfonic acid admixture having a sulfonic acid group in the molecule. When these conventionally known cement admixtures are used in combination, a cement admixture that exhibits stable dispersion performance regardless of the brand or lot number of the cement is obtained.

The sulfonic acid-based admixture is an admixture that exhibits dispersibility to cement due to electrostatic repulsion mainly caused by sulfonic acid groups, and various conventionally known sulfonic acid-based admixtures can be used. A compound having an aromatic group in the molecule is preferred. For example, polyalkylaryl sulfonate systems such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate, anthracene sulfonic acid formaldehyde condensate; melamine formalin resin sulfonate system such as melamine sulfonic acid formaldehyde condensate; amino Aromatic aminosulfonates such as aryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; various sulfonic acid admixtures such as polystyrene sulfonates Is mentioned. For concrete with a high water / cement ratio, lignin sulfonate-based admixtures are preferably used, whereas for concrete with a moderate water / cement ratio where higher dispersion performance is required, Admixtures such as polyalkylaryl sulfonates, melamine formalin sulfonates, aromatic amino sulfonates, and polystyrene sulfonates are preferably used. In addition, the sulfonic acid type admixture having a sulfonic acid group in the molecule may be used alone or in combination of two or more.

As the cement admixture, in addition to the sulfonic acid admixture, an oxycarboxylic acid compound can be used in combination. By containing the oxycarboxylic acid-based compound, higher dispersion retention performance can be exhibited even in a high-temperature environment.
The oxycarboxylic acid compound is preferably an oxycarboxylic acid having 4 to 10 carbon atoms or a salt thereof, and gluconic acid or a salt thereof is preferably used as the oxycarboxylic acid compound.

The cement admixture may be used in combination with conventionally known cement additives (materials) as exemplified in the following (1) to (11) as necessary.
(1) Water-soluble polymer substances (2) Polymer emulsions (4) Early strengthening agents / accelerators (5) Antifoam agents other than oxyalkylenes (6) AE agents (7) Other surfactants (8) Waterproofing Agent (9) Rust preventive agent (10) Crack reducing agent (11) Expanding material

Other conventionally known cement additives (materials) include cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust preventives, colorants, anti-corrosion agents. A mold agent etc. can be mentioned. These conventionally known cement additives (materials) may be used alone or in combination of two or more.

The cement admixture of the present invention may be used in the form of an aqueous solution, or after reaction, neutralized with a divalent metal hydroxide such as calcium or magnesium to obtain a polyvalent metal salt and then dried. , Supported on inorganic powder such as silica-based fine powder and dried, or dried and solidified into a thin film on a support using a drum-type drying device, a disk-type drying device or a belt-type drying device, and then pulverized Alternatively, it may be used after being powdered by drying and solidifying with a spray dryer. Also, the powdered cement admixture of the present invention is blended in advance into a cement composition not containing water such as cement powder and dry mortar, and used as a premix product for plastering, floor finishing, grout, etc. Alternatively, it may be blended when the cement composition is kneaded.

The cement admixture can be used for various hydraulic materials, that is, cement compositions such as cement and gypsum and other hydraulic materials. Specific examples of a hydraulic composition containing such a hydraulic material, water, and the cement admixture of the present invention, and further containing fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary. Examples thereof include cement paste, mortar, concrete, plaster and the like.

Among the hydraulic compositions, a cement composition that uses cement as a hydraulic material is the most common, and the cement composition contains the cement admixture of the present invention, cement, and water as essential components. Is preferred. Such a cement composition is also one aspect of the present invention. That is, a cement composition containing cement and the thiol-modified monomer and / or the (poly) alkylene glycol chain-containing thiol polymer is also one aspect of the present invention.

In the cement composition of the present invention, the cement is not particularly limited. For example, Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate-resistant and low alkali types thereof), various mixed cements (blast furnace cement) , Silica cement, fly ash cement), white Portland cement, alumina cement, super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement), grout cement, oil well cement, low heat cement (low Manufactured using one or more of exothermic blast furnace cement, fly ash mixed low exothermic blast furnace cement, high belite content cement, ultra-high strength cement, cement-based solidified material, eco-cement (city waste incineration ash, sewage sludge incineration ash Cement, etc.), and blast furnace Rugs, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, a fine powder and gypsum limestone powder may be added. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., the aggregates are siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia. Refractory aggregate such as can be used.

In the cement composition, unit water amount of 1m per ^3, the cement usage amount and the water / cement ratio, unit water content is preferably 100 kg / ^{m 3} or more, 185 kg / ^{m 3} or less, more preferably 120 kg / ^{m 3} or more 175 kg / m ³ or less, the amount of cement used is preferably 200 kg / m ³ or more and 800 kg / m ³ or less, more preferably 250 kg / m ³ or more and 800 kg / m ³ or less, and the water / cement ratio (mass Ratio) is preferably 0.1 or more and 0.7 or less, more preferably 0.2 or more and 0.65 or less, and it can be used widely from poor blending to rich blending. The cement admixture of the present invention has a high water reduction rate region, that is, a water / cement ratio of water / cement ratio (mass ratio) = 0.15 or more and 0.5 or less (preferably 0.15 or more, 0.4 or less). It can be used even in a low ratio region. Furthermore, it is effective for both high-strength concrete having a large unit cement amount and a small water / cement ratio, and poor-mixed concrete having a unit cement amount of 300 kg / m ³ or less.

As a blending ratio of the thiol-modified monomer of the present invention and / or (poly) alkylene glycol chain-containing thiol polymer in the cement composition, for example, when used for mortar or concrete using hydraulic cement, The total amount of these is preferably 0.01% by mass or more and 10% by mass or less of the cement mass in terms of solid content. As a result, various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability are brought about. If it is less than 0.01%, the performance may not be sufficient, and if it exceeds 10% by mass, the effect of improving dispersibility is substantially saturated, and the present invention is more than necessary. The cost of manufacturing may increase. More preferably, they are 0.02 mass% or more and 5 mass% or less, More preferably, they are 0.05 mass% or more and 3 mass% or less, Especially preferably, they are 0.1 mass% or more and 2 mass% or less.

The cement composition has high dispersibility and dispersion retention performance even in a high water reduction rate region, and exhibits sufficient initial dispersibility and viscosity reduction even at low temperatures, and has excellent workability. , Ready mixed concrete, concrete for concrete secondary products (precast concrete), concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, etc. Is required to have high fluidity such as high-fluidity concrete (slump value of 25 cm or more, concrete with slump flow value of 50-70 cm), self-filling concrete, self-leveling material, etc. It is also effective for mortar and concrete.

Since the thiol-modified monomer of the present invention has the above-described configuration, it is remarkably excellent in various performances, particularly hydrolysis resistance and dispersion performance. In addition, a polymer obtained by polymerizing an unsaturated carboxylic acid monomer or an unsaturated polyoxyalkylene glycol monomer in the presence of such a monomer has extremely high dispersibility. Therefore, it is particularly useful as a dispersant and a cement admixture, and makes a great contribution in the civil engineering / construction field and the like that handle concrete.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, “%” means “mass%”, and “−” in the table does not measure or analyze, or does not use the indicated component. Means.
Each abbreviation described in this specification is shown in Table 1.

First, gel permeation chromatography (GPC) of polyalkylene glycol (also referred to as “PAG”), thiol-modified monomer (also referred to as “PAG thiol”), (poly) alkylene glycol chain-containing thiol polymer, and comparative polymer. ) Analysis conditions / analysis conditions and liquid chromatography (LC) analysis conditions / analysis conditions will be described. Moreover, the measuring method which calculates | requires solid content of PAG thiol, (poly) alkylene glycol chain containing thiol polymer, and a comparison polymer is also demonstrated.

<GPC analysis method>
The raw material PAG analyzed the number average molecular weight (Mn) under the following conditions, and the average added mole number (AO repeating unit number) of the oxyalkylene group (AO) in the PAG was calculated from this Mn. Moreover, the weight average molecular weight and number average molecular weight of the polymer of the present invention obtained in Examples and the comparative polymers obtained in Comparative Examples were measured using the following measurement conditions.
Device: Waters Alliance (2695)
Analysis software: Waters, Empor professional + GPC option column: Tosoh Co., Ltd., TSK guard column SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: A solution prepared by dissolving 115.6 g of sodium acetate trihydrate in a mixed solvent of 10999 g of water and 6001 g of acetonitrile and adjusting the pH to 6.0 with acetic acid was used.
Standard substance for preparing calibration curve: polyethylene glycol (peak top molecular weight (Mp) 272500, 219300, 107000, 50000, 24000, 12600, 7100, 4250, 1470)
Calibration curve: Prepared by a cubic equation based on the Mp value and elution time of the polyethylene glycol.
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Measurement time: 45 minutes Sample solution injection amount: 100 μL (PAG, PAG thiol is an eluent solution having a sample concentration of 0.4% by mass and polymer is a sample concentration of 0.5% by mass)

<GPC analysis conditions (polymer analysis: G-3)>
In the obtained RI chromatogram, the portions that were flat and stable in the baseline immediately before and after elution of the polymer were connected by straight lines, and the polymer was detected and analyzed. However, when the monomer, impurities derived from the monomer, low molecular weight peaks thought to be derived from PAG thiol, etc. are partially overlapped with the polymer peak, they are vertically divided at the most concave portion of the overlapping portion of the polymer and the polymer peak. Thus, the polymer part and the monomer part were separated, and the molecular weight and molecular weight distribution of only the polymer part were measured. When the polymer part and other parts could not be completely overlapped and separated, they were calculated together.
Calculation of polymer purity:
From the ratio of the peak area by the RI detector, the calculation was performed as follows.
Polymer pure content = (polymer peak area) / (polymer peak area + peak area other than polymer)

<LC analysis method>
An example of the analysis method by LC is shown. However, some PAG thiol structures cannot be analyzed under these conditions. In that case, the analysis was performed by appropriately changing the conditions such as the LC column and the eluent.
Device: Waters Alliance (2695)
Analysis software: Emper professional manufactured by Waters + GPC option column: GL Science Inertsil ODS-2 guard column + column (inner diameter 4.6 mm x 250 mm x 3)
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: acetonitrile / 100 mM acetate ion exchange aqueous solution = 40/60 (mass%) mixture using 30% NaOH aqueous solution and adjusting to pH 4.0 Flow rate: 0.6 mL / min
Column temperature: 40 ° C
Sample solution injection amount: 100 μL (eluent solution having a sample concentration of 1% by mass)

<LC analysis conditions: analysis of PAG thiol>
Calculation of total esterification rate:
From the ratio of the peak area by the RI detector, the calculation was performed as follows.
Total esterification rate = (monoester peak area + diester peak area) / (raw material PAG area + monoester peak area + diester peak area)
Calculation of diester / total ester ratio:
From the ratio of the peak area by the RI detector, the calculation was performed as follows.
Diester / total ester ratio = (diester peak area) / (monoester peak area + diester peak area)
Here, the monoester is a monothiol-modified monomer, and the diester is a dithiol-modified product.

<Measurement method of solid content>
About 0.5 g of a sample was weighed on an aluminum dish, diluted with about 1 g of water, and spread evenly. The sample was dried at 130 ° C. for 1 hour in a nitrogen atmosphere, allowed to cool in a desiccator, and then weighed after drying. The solid content (nonvolatile content) concentration was calculated from the difference in mass before and after drying.
As the concentration of the PAG thiol and the aqueous solution of the polymer, the solid content measured by the above procedure was used unless otherwise specified.

(PAG)
The raw material PAG (PAG Nos. G-3, G-12, G-13, and G-14) is shown in Table 2.

In Table 2, “PEG” means polyethylene glycol (the same applies hereinafter). In addition, “(EO) / (AO) wt” means a mass ratio of ethylene oxide in 100% by mass of all alkylene oxides (AO) constituting PAG, and “terminal secondary OH ratio” means that of PAG. A value (%) obtained by dividing the number of hydroxyl groups derived from the secondary alcohol residue located at the terminal by the number of hydroxyl groups at all terminals of the PAG, that is, “terminal secondary OH ratio (%) = terminal secondary OH group number / It means “the number of OH groups at all terminals” and can be analyzed by NMR.
Here, when the structure in the case where the terminal of the PAG is a group derived from a secondary alcohol residue is schematically shown, for example, the following formula:
HO- (C (R) -C-O)-(C-C-O)-(C-C-O) -...
(R represents an organic residue), and the structure in the case where the end of the PAG is derived from a primary alcohol residue is, for example, the following formula:
HO- (C-C (R) -O)-(C-C-O)-(C-C-O) -...
As shown.

In Table 2, G-12 to G-14 PAGs were synthesized by the method described in JP-A No. 2002-173593. That is, it synthesize | combined as follows. When the raw material alcohol had a low boiling point and could not be dehydrated under reduced pressure, the reaction was carried out by separately adjusting a part of the alcohol to sodium alkoxide. For polyalkylene glycol having a large number of additions of AO (alkylene oxide) and the reaction cannot be completed in one stage, the same procedure was repeated until the predetermined number of additions of AO was reached.
(1) Synthesis method of polyalkylene glycol (addition of ethylene oxide)
Raw alcohol and 500 ppm sodium hydroxide (30% aqueous solution) with respect to the finished weight were charged into a pressure-resistant reaction vessel equipped with a stirrer. The inside of the reaction system was heated to 100 ° C. using an oil bath, and while slowly bubbling nitrogen through the system, the pressure was reduced to 100 Torr with a vacuum pump for 2 hours to distill off the water. The inside of the reactor was heated to 150 ° C., and nitrogen was introduced to adjust the internal pressure to 0.2 MPa. While maintaining the reactor internal temperature at 150 ± 2 ° C., a predetermined amount of ethylene oxide was added. However, the ethylene oxide partial pressure in the reactor did not exceed 50% so that the reactor internal pressure did not exceed 0.8 MPa. After completion of the addition of ethylene oxide, the inside of the reactor was kept at 150 ° C. for 1 hour to complete the reaction.
(2) Synthesis method of polyalkylene glycol (addition of propylene oxide and butylene oxide)
The procedure was the same as (1) except that the reaction temperature was 125 ° C.

Comparative Example P13, Examples P26 to P30
(Production of PAG thiol)
As shown in Tables 4-1 to 4-2, a predetermined PAG, a thiol group-containing compound (a compound having a carboxyl group or a hydroxyl group and a mercapto group in one molecule), an acid catalyst and an antioxidant are used as raw materials. A thiol-modified monomer (PAG thiol) was prepared at a predetermined reaction temperature and reaction time. The structure and the like of the main component of the obtained product are shown in Table 4-4.
Moreover, the manufacturing method 1 in Table 4-1 is as follows.

<Production method 1>
(1) Esterification process The raw material is placed in a glass reactor equipped with a moisture meter with a Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirring seal, and a temperature sensor with a glass protective tube. Prepared. After filling the moisture determination receiver with cyclohexane (solvent), the reaction system was heated to reflux with stirring. The reaction system was heated for a predetermined time while cyclohexane was added in the middle so that the temperature in the reaction system would be 110 ± 5 ° C. to carry out dehydration esterification reaction.
The reaction time was determined based on the theoretical dehydration amount and LC and GPC analysis results.
(2) Desolvation step After the esterification step, the reaction solution was allowed to cool to 60 ° C. or lower while stirring so as not to solidify, and then a predetermined amount of a 30% NaOH aqueous solution and water mixture was quickly charged into the reactor. . Next, this reaction solution was heated to about 70 ° C., and after the reflux had settled, the temperature was gradually increased to about 100 ° C. to distill off cyclohexane. After the solvent was distilled off, heating was stopped and nitrogen was bubbled at 30 mL / min for 90 minutes while cooling to remove residual cyclohexane to obtain an aqueous solution of a thiol-modified monomer (PAG thiol).
(3) ¹ H-NMR analysis A part of the sample after the esterification step of PAG thiol was collected, the solvent was replaced with deuterated chloroform, and a ¹ H-NMR spectrum was measured.
(i) Measurement condition equipment: Varian 400 MHz-NMR Unity plus
Solvent: CDCl ₃ (containing 0.05 vol% of TMS)
Temperature: 30 ° C
Total: 32 times
(ii) Results The results are shown in Table 3 below.

From Table 3, since the peak position derived from the raw material was partially shifted and a peak derived from an ester bond was generated, it was confirmed that an esterified product of PEG and 3-MPA, which were target products, was generated.
In addition, in Table 3, although only the analysis result about T-9 obtained by comparative example P13 is described, the product obtained by Example P26-P30 also becomes the same analysis result.

For Comparative Example P13 and Examples P26 to P30, the total esterification rate, diester / total ester, and pure thiol-modified monomer content of the reaction crude product after the esterification step were analyzed. Moreover, the total esterification rate of the thiol modified monomer (PAG thiol) obtained after the solvent removal step, the diester / total ester, and the pure content of the thiol modified monomer were analyzed. The results are shown in Table 4-3.

Comparative Example F93, Examples F95-F97
((Poly) alkylene glycol chain-containing thiol polymer)
Next, using the thiol-modified monomer (PAG thiol) obtained in Comparative Example P13, Example P26, P28 or P29, (meth) acrylic acid as an unsaturated carboxylic acid monomer and unsaturated Examples and reference examples of polymers obtained by polymerizing polyalkylene ethylene glycol monomers (hereinafter also referred to as “PEG monomers”) as (poly) alkylene glycol monomers will be described.
Polymers were synthesized under the polymerization conditions described in Tables 5-1 to 5-2. The analysis results for each polymer are as described in Table 5-1.
In these Examples and Comparative Examples, the composition of the polymer is expressed as a mass ratio in terms of SMAA (when the unsaturated carboxylic acid monomer is completely neutralized with NaOH). Therefore, the total is not 100%.

Moreover, the manufacturing method F-1 in a table | surface is as follows.
<Method F-1>
As the monomer solution, an aqueous solution of a predetermined amount of monomer, PAG thiol, and sodium hydroxide was prepared. A predetermined amount of an aqueous initiator solution was prepared as an initiator solution.
A predetermined amount of water is charged into a glass reactor equipped with a Dimroth cooling pipe, a Teflon (registered trademark) stirring blade and a stirring seal, a nitrogen gas introduction pipe, and a temperature sensor. The gas was heated to a predetermined temperature while being introduced at 100 to 200 mL / min. Subsequently, a predetermined amount of the monomer solution was dropped into the reactor over 4 hours and the initiator solution over 5 hours, and after completion of the dropping, the polymerization reaction was completed by holding at a predetermined temperature for 1 hour. After cooling to room temperature, a 30% aqueous NaOH solution was added as necessary to adjust the pH to obtain an aqueous polymer solution.

In addition, the polymer obtained in the above-mentioned production method F-1 has a polymer part bonded to both ends of the (poly) alkylene glycol chain (1) via a sulfur atom-containing group, and the polymer part is unsaturated. Polymer having carboxyl group derived from carboxylic acid monomer (methacrylic acid) and (poly) alkylene glycol chain (2) derived from unsaturated (poly) alkylene glycol monomer (methoxypolyethylene glycol methacrylate) ( a polymer (i) having a polymer part (similar structure as described above) having iii) as a main component and bonded to one end of the (poly) alkylene glycol chain (1) via a sulfur atom-containing group; Repeating a structural unit having a polymer part (similar structure as described above) bonded to one end of the alkylene glycol chain (1) via a sulfur atom-containing group A small amount of a polymer (ii) having a polymer moiety (1) and a polymer (iv) having a (poly) alkylene glycol chain (1) bonded via a sulfur atom-containing group to both ends of a polymer portion (same structure as described above) It was a mixture containing.

The polymers obtained in Comparative Example F93 and Examples F95 to F97 were evaluated for hydrolysis performance (storage stability performance) as follows.
<Test method for hydrolyzability (60 ° C.)>
Comparative polymer B-136 obtained in Comparative Example F93, Polymer B-138 obtained in Example F95, Polymer B-139 obtained in Example F96, or Polymer B-140 obtained in Example F97 Were each prepared, and the pH value of the polymer aqueous solution was set in three stages of 5.5, 6 or 7. About three types of polymer aqueous solutions per one polymer, weight average molecular weight (Mw), peak top molecular weight (Mp), number average molecular weight (Mn) and polymer when stored at a liquid temperature of 60 ° C. for 0 to 135 days Pure content was measured over time. Moreover, the decreasing rate of the weight average molecular weight (Mw) on the basis of immediately after pH adjustment (storage day 0) was calculated. During the storage period, the temperature of the aqueous polymer solution was maintained at 60 ° C. The results are shown in Tables 6-1 to 6-4. Moreover, the graph which contrasted Mw fall rate of Table 6-1 to 6-4 for every pH value is shown to FIGS.

Here, in a polymer having an ester bond, when hydrolysis of the ester bond portion proceeds, the molecular weight (Mw, etc.) is lowered. Specifically, the polymer represented by the general formula (3) will be described as an example.
P ¹ —S—R ¹ —COO— (AO) n —OC—R ² —SP ²
→ P ¹ —S—R ¹ —COO— (AO) n—H
→ P ¹
As a result, the molecular weight (Mw, etc.) decreases. Therefore, it can be said that hydrolysis resistance is so high that the fall rate of a weight average molecular weight (Mw) is small.
From this viewpoint, when comparing the Mw reduction rate from Tables 6-1 to 6-4 and FIGS. 1 to 3, the polymer B-138 (Example F95) obtained using the thiol-modified monomer of the present invention, heavy Both the combined B-139 (Example F96) and B-140 (Example F97) have a significantly lower Mw reduction rate than the comparative polymer B-136 (Comparative Example F93). For example, after 135 days, the difference may be 10% or more at pH = 5.5, 20% or more at pH = 6, and about 30% or more at pH = 7. From this result, it was found that the hydrolysis resistance of the polymer was remarkably improved by using the thiol-modified monomer of the present invention, so that the performance can be more stably exhibited over a long period of time.

Comparative Example F1
(Comparative polymer)
Next, a comparative example of a comparative polymer obtained by polymerizing (meth) acrylic acid and a polyethylene glycol monomer (hereinafter also referred to as “PEG monomer”) in the absence of PAG thiol will be described.
Polymers were synthesized under the polymerization conditions described in Tables 7-1 to 7-2. The analysis results for each polymer are as shown in Table 7-1.

In these tables, the composition of the polymer is expressed as a mass ratio in terms of SMAA (when the unsaturated carboxylic acid monomer is completely neutralized with NaOH).
Production method F-4 in the table is as follows.
<Method F-4>
As the monomer / chain transfer agent solution, an aqueous solution containing a predetermined amount of monomer and chain transfer agent was prepared. In addition, a predetermined amount of an aqueous initiator solution was prepared as an initiator solution.
A predetermined amount of water was charged into a glass reactor equipped with a Dimroth cooling pipe, a Teflon (registered trademark) stirring blade and a stirring seal, a nitrogen gas introduction pipe, and a temperature sensor, and nitrogen was stirred at 200 rpm. The gas was heated to a predetermined temperature while being introduced at 100 to 200 mL / min. Subsequently, a predetermined amount of the monomer solution was dropped into the reactor over 4 hours and the initiator solution over 5 hours, and after completion of the dropping, the polymerization reaction was completed by holding at a predetermined temperature for 1 hour. After cooling to room temperature, a 30% aqueous NaOH solution was added as necessary to adjust the pH to obtain an aqueous solution of a comparative polymer.
The obtained comparative polymer has a carboxyl group derived from an unsaturated carboxylic acid monomer (methacrylic acid) and a (poly) alkylene glycol chain derived from an unsaturated (poly) alkylene glycol monomer (methoxypolyethylene glycol methacrylate). It is a polymer having (2) but no (poly) alkylene glycol chain (1).

(Dispersant, cement admixture)
Test Examples 1-1 to 5-3
Next, test examples in which the dispersion performance and the like of the polymer of the present invention obtained in Examples F95 to F97 and the comparative polymer obtained in Comparative Example F93 were evaluated will be described.
In addition, about the polymer used by Test Example 2-1 to 5-3, after obtaining polymer aqueous solution by the comparative example F93 mentioned above or Example F95-F97, immediately after adjusting to the pH value shown in Table 8 ( That is, the following mortar tests were performed before polymer hydrolysis.

<Method for evaluating dispersion performance: mortar test>
The mortar test was performed in an environment where the temperature was 20 ° C. ± 1 ° C. and the relative humidity was 60% ± 10%.
The mortar formulation was C / S / W = 550/1350/220 (g). However,
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: Standard sand for cement strength test (Cement Association)
W: As an ion exchange aqueous solution W of the polymer of the present invention or a comparative polymer and an antifoaming agent, an addition amount of the polymer aqueous solution shown in Table 8 was weighed, and an antifoaming agent MA-404 (Pozoris products) In solid form, 10% by mass was added to the solid content of the polymer, and ion exchange water was further added to obtain a predetermined amount, which was sufficiently uniformly dissolved. In Table 8, the addition amount of the polymer is expressed in terms of wt% of the polymer solid content with respect to the cement weight.
A stainless beater (stirring blade) was attached to a Hobart mortar mixer (model number N-50; manufactured by Hobart), C and W were added, and kneaded at a first speed for 30 seconds. Further, S was added over 30 seconds while kneading at a first speed. After the completion of S addition, the kneading was continued for 30 seconds in duplicate, then the mixer was stopped, the mortar was scraped off for 15 seconds, and then allowed to stand for 75 seconds. The mixture was allowed to stand for 75 seconds and then kneaded at a second speed for 60 seconds to prepare a mortar.

The mortar was transferred from the kneading vessel to a 1 L polyethylene container, stirred 20 times with a spatula, and then immediately packed in a half of a flow cone (described in JIS R5201-1997) placed on a flow table (described in JIS R5201-1997). I struck it with a stick, and stuffed the mortar to the full extent of the flow cone and struck it with a stick with 15 turns. Immediately after that, the flow cone is pulled up vertically, and the diameter of the expanded mortar (the diameter of the longest part (major axis) and the diameter of the part forming 90 degrees with respect to the major axis) is measured at two locations, and the average value is 0 times. The flow value was used. Immediately after measuring the zero stroke flow value, 15 falling motions were given in 15 seconds, and the diameter of the expanded mortar (the diameter of the longest part (major axis) and the diameter of the part forming 90 degrees with respect to the major axis) was 2 The points were measured and the average value was taken as the 15-stroke flow value. Moreover, the amount of mortar air was also measured as needed.
The 15-stroke flow value is superior in dispersion performance as the numerical value is larger. Further, when mortar is prepared without a dispersant such as a polymer under these conditions, kneading cannot be performed sufficiently and fluidity does not appear in the mortar. The 0-stroke flow value is around 105 mm, and the 15-stroke flow value is around 145 mm.

In Table 8, “Example” means a test example corresponding to the Example, and “Comparative Example” means a test example corresponding to the Comparative Example. In addition, it shows that the mortar dispersion performance by a polymer is so high that a 15 strike flow value is large.
Table 8 confirmed the following.
In Test Examples 3-1 to 5-3 using the polymer (B-138 to B-140) of the present invention, both are more than Test Examples 1-1 and 1-2 (Comparative Polymer F-1). It can be seen that an equivalent flow value can be achieved with a small amount of polymer added. When the polymer addition amount is compared with the equivalent flow value, the polymer of the present invention is 82.4 (= 0.07 / 0.085) to 87.5 (relative to the addition amount of the comparative polymer of 100% by mass). = 0.07 / 0.08)% by mass, and it is clear that the polymer of the present invention can exhibit high dispersibility with a smaller addition amount.

In addition, when Test Examples 2-1 to 2-3 (Comparative Polymer B-136) and Test Examples 3-1 to 5-3 (B-138 to B-140) are compared, there is almost no difference in performance. This is because the comparative polymer B-136 has a structure similar to the structure of B-138 to B-140 (the structure represented by the above general formula (3) or (4)), and ( AO) It is thought that it originates in having (poly) alkylene glycol chain (1) represented by n. The comparative polymer F-1 is a normal polymer having no such (poly) alkylene glycol chain (1), that is, P ¹ , P ^{2 in the} general formula (3) or (4), or It is a polymer corresponding to only the P ³ site.
However, as described above, the comparative polymer B-136 is easily hydrolyzed with time, whereas the polymer of the present invention (B-138 to B-140) has extremely high hydrolysis resistance, so that It can be said that the polymer of the present invention has an extremely excellent effect in that the high dispersion performance can be exhibited more stably over time.

FIG. 1 is a graph showing the rate of decrease in weight average molecular weight (Mw) with time at pH = 5.5 described in Tables 6-1 to 6-4. FIG. 2 is a graph showing the rate of decrease in weight average molecular weight (Mw) with time at pH = 6 described in Tables 6-1 to 6-4. FIG. 3 is a graph showing the rate of decrease in weight average molecular weight (Mw) with time at pH = 7 described in Tables 6-1 to 6-4.

Claims (7)

The following general formula (1) or (2):

(In the formula, R ¹ and R ² are the same or different and represent an organic residue. AO is the same or different and represents one or more of oxyalkylene groups having 2 to 18 carbon atoms. N Represents an average number of moles of an oxyalkylene group and is an integer of 1 to 1000. R ³ represents a hydrogen atom or an organic residue.) A thiol-modified monomer having a structure represented by:
At least one unit of the terminal of the (poly) alkylene glycol chain represented by (AO) n is an oxyalkylene group having 3 or more carbon atoms, or the organic represented by R ¹ and / or R ² A thiol-modified monomer, wherein the residue has a tertiary or higher carbon atom at the carbonyl group side terminal. One or both of the ester bonds in the structure represented by the general formula (1) or (2) are at least one group selected from the group consisting of R ¹ , R ² , and (AO) n. The thiol-modified monomer according to claim 1, wherein the thiol-modified monomer is bonded to a tertiary or higher carbon atom therein. A method for producing the thiol-modified monomer according to claim 1 or 2,
The method for producing a thiol-modified monomer includes a step of esterifying a compound having a carboxyl group and a mercapto group in one molecule with (poly) alkylene glycol. Polymerization of an unsaturated monomer component containing an unsaturated carboxylic acid monomer and / or an unsaturated (poly) alkylene glycol monomer in the presence of the thiol-modified monomer according to claim 1 A (poly) alkylene glycol chain-containing thiol polymer obtained by A dispersant comprising the thiol-modified monomer according to claim 1 or 2 and / or the (poly) alkylene glycol chain-containing thiol polymer according to claim 4. A cement admixture comprising the thiol-modified monomer according to claim 1 or 2 and / or the (poly) alkylene glycol chain-containing thiol polymer according to claim 4. A cement composition comprising cement and the thiol-modified monomer according to claim 1 or 2 and / or the (poly) alkylene glycol chain-containing thiol polymer according to claim 4.

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