JP2008266621A - Thiol-modified monomer and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thiol-modified monomer mixture which is excellent in various performances, particularly significantly excellent in dispersibility, and capable of providing a component which is useful in various applications such as an admixture for cement, a polyalkylene glycol chain-containing thiol polymer obtained by using the monomer mixture and a dispersant and an admixture for cement, each including the polymer, and a cement composition. <P>SOLUTION: The thiol-modified monomer mixture has a structure represented by general formula (1) and/or general formula (2) (wherein R<SP>1</SP>and R<SP>2</SP>may be same or different and represent organic residues; AO may be same or different and represent at least one kind of 2-18C alkylene glycol group; n represents average number of moles of oxyalkylene group and is an integer of 80-500 and R<SP>3</SP>is a hydrogen atom or an organic residue). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a thiol-modified monomer, a polyalkylene glycol chain-containing thiol polymer obtained by using the monomer, a dispersant, a cement admixture and a cement composition using these.

A mercapto group (thiol group, SH group) is a functional group useful for organic synthesis because of its unique reactivity. Therefore, thiol compounds having at least one mercapto group in the molecule are used for various applications by utilizing the unique reactivity of the mercapto group. For example, a mercapto group has been introduced into polyalkylene glycol as an extension of the application field of polyalkylene glycol, which has been useful for applications such as adhesives and sealants as soft segments, and components that impart flexibility to various polymers. A thiol-modified product of polyalkylene glycol obtained in this manner has attracted attention.

By the way, as an application field of polyalkylene glycol, in recent years, cement compositions (cement paste with water added to cement, mortar in which fine aggregate sand is mixed with cement paste, and pebbles that are coarse aggregate in mortar are mixed. Cement admixtures added to concrete, etc.) have been 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.

Conventional cement admixtures include, for example, naphthalene cement admixtures and polycarboxylic acid cement admixtures. For example, unsaturated carboxylic acid monomers and unsaturated polyalkylene glycol ether single monomers. A copolymer for cement admixture obtained by copolymerizing a monomer 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 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.

In addition, as a conventional thiol-modified product of polyalkylene glycol, for example, both ends obtained by adding thiocarboxylic acid to a polyether having a double bond at both ends or one end and then decomposing the resulting thioester group or Polyether having a mercapto group at one end (see, for example, Patent Document 1) or a modified polysiloxane having a compound having a mercapto group introduced into a polyether compound by an ester reaction as a biodegradable water-soluble polymer used in a detergent builder A polymer obtained by subjecting an ether compound to block or graft polymerization of a monoethylenically unsaturated monomer component (for example, see Patent Document 2) 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 improvement 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 Laid-Open No. 7-13141 JP-A-7-109487

The present invention has been made in view of the above-described present situation, and is excellent in various performances, particularly dispersion performance, and can provide a useful component for various uses such as a cement admixture and the production method thereof, It is an object of the present invention to provide a polyalkylene glycol chain-containing thiol polymer obtained by using a monomer, a dispersant and a cement admixture containing these, and a cement composition.

The present inventors have made various studies on the components used in obtaining a polymer containing a polyalkylene glycol chain. As a result, the thiol-modified monomer having a specific structure having a polyalkylene glycol chain and at least one mercapto group is used. As a body, it was found to be a novel compound that has never existed before, and it was found that the monomer itself can also exhibit a high degree of dispersion performance. And in the presence of the monomer, it contains a polyalkylene glycol chain obtained by polymerizing an unsaturated monomer component containing an unsaturated carboxylic acid monomer and / or an unsaturated polyalkylene glycol ether monomer. It has been found that the thiol polymer can exhibit extremely high dispersion performance due to the steric repulsion of the oxyalkylene group derived from the thiol-modified monomer having a specific structure, and is particularly excellent in cement dispersion performance. The inventors have found that the use of the coalescence as a cement admixture can significantly reduce the amount of the blended composition when adjusting the cement composition, and have conceived 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 polyalkylene glycol is employed, a high molecular weight is obtained. It has been found that the thiol-modified monomer can be obtained easily, efficiently and with high purity at low cost, and the present invention has been achieved.

The applicant of the present application has, as Japanese Patent Application No. 2006-256292, a polyalkylene glycol chain, and a polymer site containing a structural unit derived from an unsaturated monomer bonded to at least one end of the polyalkylene glycol chain, The invention relating to a polymer in which at least one of the unsaturated monomers constituting the polymer portion is an unsaturated carboxylic acid monomer or an unsaturated (poly) alkylene glycol monomer has been filed. The polymers obtained using the thiol-modified monomers of the invention are further limited and are more effective than the prior inventions with respect to the advantageous effects described herein.

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

(.N wherein, R ¹ and R ² are the same or different, .AO represents an organic residue, the same or different and each represents one or more kinds of oxyalkylene group having 2 to 18 carbon atoms Represents an average number of moles of an oxyalkylene group and is an integer of 80 to 500. R ³ represents a hydrogen atom or an organic residue.

The present invention is also a method for producing the thiol-modified monomer, which comprises a step of esterifying a compound having a carboxyl group and a mercapto group in one molecule with polyalkylene glycol. It is also a method for producing a thiol-modified monomer.

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 polyalkylene glycol chain-containing thiol polymer obtained.
The present invention is also a dispersant containing the above polyalkylene glycol chain-containing thiol polymer.
The present invention is also a cement admixture containing the thiol-modified monomer and / or the polyalkylene glycol chain-containing thiol polymer.
The present invention is also a cement composition comprising cement and the thiol-modified monomer and / or the polyalkylene 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, and a production mode of a thiol-modified monomer represented by formulas (1) and (2) Can be appropriately changed depending on the case, and is not particularly limited. Examples of such an organic residue include an aromatic group such as a linear or branched alkylene group having 1 to 18 carbon atoms, a phenyl group, an alkylphenyl group, a pyridinyl group, thiophene, pyrrole, furan, and thiazole. It is done. In addition, as described later, the production of the thiol-modified monomer is a compound having a carboxyl group and a mercapto group in one molecule in a polyoxyalkylene glycol (a carboxyl group and at least one thiol group in the same molecule). R ¹ and R ² can be a mercaptocarboxylic acid residue (a divalent organic residue excluding a mercapto group and a carboxyl group).
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.

In the general formulas (1) and (2), R ³ represents a hydrogen atom or an organic residue, and the organic residue is more specifically a hydrocarbon group having 1 to 20 carbon atoms. preferable. 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. Moreover, when AO is comprised from 2 or more types of oxyalkylene groups, these oxyalkylene groups may be introduce | transduced in the block form or random.
When the thiol-modified monomer of the present invention is used for the production of a cement admixture component, AO is mainly a relatively short chain having about 2 to 8 carbon atoms from the viewpoint of affinity with cement particles. An oxyalkylene group is preferred. More preferably, it is mainly an oxyalkylene group having 2 to 4 carbon atoms, and more preferably an oxyalkylene group (oxyethylene group) mainly having 2 carbon atoms. Particularly preferred is an embodiment containing 75% by mass or more of oxyethylene groups with respect to 100% by mass of all oxyalkylene groups constituting the oxyalkylene chain represented by-(AO) n-. With this configuration, the thiol-modified monomer has higher hydrophilicity.

By including an oxyalkylene group having 3 or more carbon atoms in the oxyalkylene chain, a certain degree of hydrophobicity is imparted to the thiol-modified monomer. When a cement admixture is obtained using such a thiol-modified monomer, it is possible to bring some structure (network) to the cement particles and reduce the viscosity and stiffness of the cement composition. However, if the oxyalkylene group having 3 or more carbon atoms is introduced too much, the hydrophobicity of the thiol-modified monomer becomes too high, and the performance of dispersing cement particles may not be sufficient.
Considering these, the ratio of the oxyalkylene group having 3 or more carbon atoms in the oxyalkylene chain is preferably 30% by mass or less with respect to 100% by mass of the oxyalkylene chain. More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less, Most preferably, it is 5 mass% or less.
Depending on the application of the thiol-modified monomer of the present invention, an embodiment that does not contain an oxyethylene group having 3 or more carbon atoms may be preferable.

In the compounds represented by the general formulas (1) to (2), the ester bond may be cleaved by hydrolysis. When improvement in hydrolysis resistance is required, it is preferable to introduce an oxyalkylene group having 3 or more carbon atoms at the end of-(AO) n-.
Examples of the oxyalkylene group having 3 or more carbon atoms include an oxypropylene group, an oxybutylene group, an oxystyrene group, and an alkyl glycidyl ether residue. Of these, an oxypropylene group and an oxybutylene group are preferable because of ease of production.
The introduction amount of the oxyalkylene group having 3 or more carbon atoms depends on the required hydrolysis resistance, but the introduction amount is preferably 50% or more with respect to both ends of-(AO) n-. Yes. More preferably, it is 100% or more, More preferably, it is 150% or more, Most preferably, it is 200% or more.

In order to improve hydrolysis resistance, it is preferable that the terminal of-(AO) n- is a secondary alcohol residue. A known method may be used to introduce a secondary alcohol group at the terminal of-(AO) n-. For example, an alkylene having 3 or more carbon atoms is added to polyalkylene glycol which is a raw material of-(AO) n-. An oxide may be added. In this addition reaction, in order to increase the introduction rate of secondary alcohol groups, at least one selected from the group consisting of alkali metals, alkaline earth metals and oxides or hydroxides thereof is used as a catalyst. It is preferable to use a compound. 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 secondary alcohol groups. More preferably, it is 70-170 degreeC, More preferably, it is 90-150 degreeC, Most preferably, it is 100-130 degreeC.

In the oxyalkylene chain, the average number of moles (average number of added moles) of the oxyalkylene group represented by n is an integer of 80 to 500. Preferably it is 90 or more, More preferably, it is 100 or more, More preferably, it is 110 or more, Especially preferably, it is 120 or more, Most preferably, it is 140 or more. The upper limit of n is not particularly limited, but when the value of n is too high, the viscosity of the raw material compound used in producing the thiol-modified monomer is increased or the reactivity is sufficient. Since the problem of workability such as failure to occur arises, n is suitably 500 or less. Preferably it is 400 or less, More preferably, it is 350 or less, More preferably, it is 300 or less, More preferably, it is 280 or less, More preferably, it is 250 or less, Most preferably, it is 220 or less, Most preferably Is 200 or less.

In the thiol-modified monomer, R ¹ and / or R ^{2 in the} general formula (1) or (2) or n is appropriately adjusted so that AO in the formula is 100 mass of the thiol-modified monomer. It is preferable to occupy 50% by mass or more in%. 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. Thus, a form in which the oxyalkylene group represented by AO occupies 50% by mass or more in 100% by mass of the thiol-modified monomer is also a preferred form of the present invention.

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 ² , 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 compounds such as nitrosobenzene and cuperone Amine compounds such as diphenylamine, di-p-fluorophenylamine, N- (3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide; TEMPO radi (2,2,6,6-tetramethylyl-1-piperidinyloxyl), stable radicals such as diphenylpicrylhydrazyl, galvinoxyl, and ferudazyl; ascorbic 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, the amount of the antioxidant is preferably 10 ppm or more, more preferably 20 ppm or more, still more preferably 50 ppm, particularly preferably 100 ppm or more, based on the mass (solid content) of the thiol-modified monomer. It is preferably 5000 ppm or less, more preferably 2000 ppm or less, still more preferably 1000 ppm or less, and particularly preferably 500 ppm or less.
Thus, the form in which the thiol-modified monomer contains the antioxidant in an amount of 10 to 5000 ppm is also one of the preferred forms of the present invention.

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, the polyoxyalkylene glycol is obtained by esterifying a compound having a carboxyl group and a mercapto group in one molecule, and a production method including such an esterification reaction step is also possible. Moreover, it is one of the present inventions.

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”), polyalkylene glycol or polyalkylene glycol may be used. Examples thereof include compounds introduced with a carboxyl group. A commercially available polyalkylene glycol may be used, or may be obtained by synthesizing 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.

In addition, when the polyalkylene glycol needs to have a carboxyl group, the carboxyl group may be introduced into the polyalkylene glycol by an ordinary method. For example, a method of oxidizing a hydroxyl group of polyalkylene glycol, a method of etherifying with monochloroacetic acid, a method of esterifying with polyvalent carboxylic acid, and the like can be mentioned.

In the above method for producing a thiol-modified monomer, as a compound having a carboxyl group or a hydroxyl group and a mercapto group in one molecule (hereinafter also simply referred to as “thiol group-containing compound”), an alkylene glycol group-containing compound is used. It is not particularly limited as long as a mercapto group can be introduced. For example, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoisobutyric acid, thiomalic acid, mercaptostearic acid, mercapto Examples include mercapto group-containing carboxylic acids such as acetic acid, mercaptobutyric acid, mercaptooctanoic acid, mercaptobenzoic acid, mercaptonicotinic acid, cysteine, N-acetylcysteine, mercaptothiazole acetic acid, mercaptoethanol, etc., and one or two of these more than It can be used.
Among these, the thiol group-containing compound is preferably a compound having a carboxyl group and a mercapto group in one molecule, and in particular, thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, mercaptoisobutyl. Acid is preferred.

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 polyalkylene 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 is bonded to the polyalkylene glycol chain (polyalkylene glycol chain (1)) derived from the thiol-modified monomer and at least one end of the polyalkylene glycol chain (1) via a sulfur atom-containing group. And a polymer portion containing a structural unit derived from the unsaturated monomer component.

With regard to such a structure, for example, when at least the unsaturated carboxylic acid monomer (a) is used as the unsaturated monomer component, the single unit is present at both ends or one end of the polyalkylene 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 the cement particle can be effectively dispersed by the steric repulsion of the polyalkylene glycol chain (1). Conceivable. Further, when at least the unsaturated (poly) alkylene glycol monomer (b) is used as the unsaturated monomer component, the monomer (on both ends or one end of the polyalkylene glycol chain (1)). b) Since it has a polyalkylene glycol chain derived from (polyalkylene glycol chain (2)), the steric repulsion of the polyalkylene glycol chain (2) is added to the steric repulsion of the polyalkylene glycol chain (1), and its synergistic effect Thus, it is considered that the performance of dispersing cement particles is improved.

In the unsaturated monomer component, examples of the unsaturated carboxylic acid monomer (a) include the following formula (9);

(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 (9) 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) include the following formula (10);

(.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 (10), 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 (10), the oxyalkylene chain represented by-(AO) _p- corresponds to the polyalkylene glycol chain (2) described above. From the viewpoint of effectively dispersing the cement particles when blended in the agent, it is preferable to have higher hydrophilicity, and mainly an oxyalkylene group having 2 carbon atoms. The ratio of the oxyalkylene group having 2 carbon atoms in such an oxyalkylene chain (polyalkylene glycol chain (2)) is 50 mol% or more with respect to 100 mol% of all oxyalkylene groups constituting the oxyalkylene chain. More preferably, it is 70 mol% or more, still more preferably 90 mol% or more, and particularly preferably 100 mol%.

In the above oxyalkylene chain (polyalkylene glycol chain (2)), when a concrete composition is produced by blending with a cement admixture, the oxyalkylene chain can be reduced from the viewpoint of reducing the viscosity and stiffness of the concrete. It is preferable to introduce a slight structure (network) to the cement particles by introducing an oxyalkylene group having 3 or more carbon atoms into the chain to impart a certain degree of hydrophobicity. However, if an oxyalkylene group having 3 or more carbon atoms is introduced too much, the resulting polymer becomes too hydrophobic, and the performance of dispersing cement particles may not be sufficient.
Considering these, the proportion of the oxyalkylene group having 3 or more carbon atoms in the oxyalkylene chain is preferably 1 mol% or more with respect to 100 mol% of all oxyalkylene groups constituting the oxyalkylene chain, More preferably 3 mol% or more, still more preferably 5 mol% or more, particularly preferably 7 mol% or more, and preferably 50 mol% or less, more preferably 30 mol% or less, still more preferably 20 The mol% or less, particularly preferably 10 mol% or less.

The oxyalkylene group having 3 or more carbon atoms in the oxyalkylene chain may be introduced in a block form or may be introduced in a random form (an oxyalkylene group having 2 or more carbon atoms). It is preferably introduced in the form of a block such as (alkylene chain)-(oxyalkylene chain comprising an oxyalkylene group having 3 or more carbon atoms)-(oxyalkylene chain comprising an oxyalkylene group having 2 or more carbon atoms).
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 the oxyalkylene chain, the average added mole number of the oxyalkylene group represented by p is an integer of 1 to 300. Preferably it is 4 moles or more, more preferably 10 moles or more, more preferably 15 moles or more, even more preferably 20 moles or more, particularly preferably 25 moles or more, most preferably 30 moles or more, and preferably 250 moles. Below, 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, most preferably 75 mol or less.

Specific examples of the monomer (b) represented by the general formula (10) 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 ( Alkoxypolyalkylene glycols obtained by adding alkylene oxides having 2 to 18 carbon atoms to aromatic alcohols having 6 to 20 carbon atoms such as silenol), nonylphenol, dodecylphenol, phenylphenol, 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 above 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 preferred to use more than one type of alkylene oxide. When adding 2 or more types of alkylene oxide, any of random addition, block addition, alternate addition, etc. may be sufficient.

In addition to the monomer (a) and the monomer (b), the unsaturated monomer component is also referred to as 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.

The amount of monomer (a), monomer (b) and monomer (c) used in the unsaturated monomer component is as follows: monomer (a) / monomer (b) / monomer When expressed as a ratio of (c) (unit: mass%), when monomer (a) is the main component, it is preferably 50 to 99/50 to 1/0 to 40, more preferably. It is 55-95 / 45-5 / 0-40, 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.

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, a polyalkylene glycol chain (1) (the above general formula (The part represented by-(AO) n- in (1) or (2)) will be introduced.
Here, the relationship between the amount of the polyalkylene glycol chain (1) and the amounts used of the monomer (a), the monomer (b) and the monomer (c) is (monomer (a) + When expressed as a ratio (unit: mass%) of the polyalkylene glycol chain (1) when the sum of monomer (b) + monomer (c) is 100%, monomer (a) is the main component. When it is a 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 radicals are chain-transferred to the thiol group, or the disulfide bond is cleaved, so that the monomers are successively introduced via one or both ends of the polyalkylene glycol chain (1) comprising the oxyalkylene group via a sulfur atom. Addition will form a polymer.
In this case, a structural unit having a carboxyl group derived from the monomer (a) via a sulfur atom at one or both ends of a polyalkylene glycol chain (1) composed of n oxyalkylene groups, and a single amount A structural unit having a polyalkylene glycol chain (2) consisting of p oxyalkylene groups derived from the body (b) and a structural unit derived from the monomer (c) when the monomer (c) is used. Are 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 polyalkylene glycol chain (2) composed of an oxyalkylene group and a structural unit derived from the monomer (c) when the monomer (c) is used is secondary. To 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.

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 6 or more. On the other hand, the polymerization reaction may be carried out at a pH of 7 or more. In this case, however, the polymerization rate is lowered, and at the same time, the polymerizability is not sufficient and the dispersion performance is lowered. It is preferable to perform a polymerization reaction. More preferably, it is less than pH 6, More preferably, it is less than pH 5.5, Most preferably, it is less than pH 5. Thus, preferable polymerization initiators that cause the polymerization system to have a pH of 7.0 or less include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate, and azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride. It is preferable to use a water-soluble azo initiator, 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 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).
A dispersant containing the polyalkylene glycol chain-containing thiol polymer (hereinafter also referred to as “polymer component”) is also one aspect of the present invention. A cement admixture containing the thiol-modified monomer (hereinafter also referred to as “monomer component”) and / or the polyalkylene glycol chain-containing thiol polymer is also one aspect of the present invention.

Hereinafter, a cement admixture will be described as a typical dispersant.
The blending amount of the polymer component in the cement admixture may be appropriately adjusted according to the desired dispersion performance, and is not particularly limited. Specifically, the cement admixture in terms of solid content is used. 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.
If necessary, the cement admixture may contain a polycarboxylic acid polymer in addition to the polymer component. In this case, the blending amount is preferably a ratio of polymer component / polycarboxylic acid polymer (unit: mass%), and is 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.

Further, when the cement admixture contains a monomer component, the content of the monomer component 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. Is preferred. 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 a ratio of monomer component / 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.
In addition, when the cement admixture includes the polymer component and the monomer component, the content thereof is preferably in the range described above as the total amount of the monomer component and the polymer component, The blending amount with the polycarboxylic acid polymer is also preferably within the above-mentioned range as the total amount of the monomer component and the polymer component.

In the cement admixture of the present invention, an antifoaming agent (such as (poly) oxyethylene (poly) oxypropylene adduct or diethylene glycol heptyl ether) or a polyalkyleneimine (such as ethyleneimine or propyleneimine) is optionally used. Polyalkyleneimine alkylene oxide adducts such as can be blended.

As the cement admixture, one or more conventionally known cement additives can be used in combination. 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 of the present invention, an oxycarboxylic acid compound can be used in combination with the above sulfonic acid admixture. 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 of the present invention may be used in combination with conventionally known cement additives (materials) as exemplified in the following (1) to (11), if 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 of the present invention 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 the hydraulic material is the most common, and the cement composition contains the cement admixture of the present invention, cement, and water as essential components. Such a cement composition is also one aspect of the present invention. That is, a cement composition including cement and the thiol-modified monomer and / or the polyalkylene glycol chain-containing thiol polymer is also one aspect of the present invention.

In the above-mentioned cement composition, 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 heat type) Manufactured using one or more of blast furnace cement, fly ash mixed low heat generation type 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), and blast furnace slurry. , 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 above 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 and 175 kg / ^{m 3} or less, the amount of cement used is preferably 200 kg / ^{m 3} or more, 800 kg / ^{m 3} or less, more preferably 250 kg / ^{m 3} or more and 800 kg / ^{m 3} or less, 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.

In the above cement composition, as a blending ratio of the cement admixture of the present invention, for example, when used for mortar or concrete using hydraulic cement, 0.01% by mass or more of the cement mass in terms of solid content, It is preferable to set it as 10.0 mass% or less. 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 10.0% by mass, the effect of improving dispersibility is substantially saturated, and more than necessary. The use of the cement admixture of the present invention may increase the production cost. More preferably, it is 0.02 mass% or more and 5.0 mass% or less, More preferably, it is 0.05 mass% or more, 3.0 mass% or less, Most preferably, it is 0.1 mass% or more, 2.0 mass% It is as follows.

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. To 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 and concrete with slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material, etc. It is also effective for mortar and concrete.

The thiol-modified monomer of the present invention has the above-described configuration. For example, in the presence of the monomer, an unsaturated carboxylic acid monomer or an unsaturated polyoxyalkylene glycol monomer is polymerized. If a polymer is obtained, the polymer can exhibit high dispersion performance as compared with a conventional copolymer for cement admixture due to steric repulsion of an oxyalkylene group derived from a thiol-modified monomer. Therefore, it is preferably used for a dispersant, particularly a cement admixture. The cement admixture of the present invention can reduce the blending amount when preparing a cement composition, and thus does not impair the excellent properties of the cement. Thus, the thiol-modified monomer of the present invention, the polymer obtained using the thiol-modified monomer, and the dispersant using the thiol-modified monomer, particularly the cement admixture, make a great contribution in the civil engineering / construction field for handling concrete. .

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, and appropriate modifications are made within a range that can meet the purpose described above and below. It is also possible to implement, and they are all included in the technical scope of the present invention. Unless otherwise noted, “%” means “mass% (% by weight)”, and “−” in the table indicates that measurement / analysis is not performed or the indicated component is used. It means not.
Each abbreviation described in the present specification is shown in Tables 1-1 to 1-3.

First, gel permeation chromatography (GPC) analysis conditions and analysis conditions of polyalkylene glycol (PAG), thiol-modified monomer (PAG thiol), polyalkylene glycol chain-containing thiol polymer and comparative polymer, and liquid chromatography (LC ) Explain analysis conditions and analysis conditions. The measurement method for determining the solid content of the thiol-modified monomer, polyalkylene glycol chain-containing thiol polymer, and comparative polymer will also be described.

<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. However, PAG No. For G-1, Mn was calculated from the mass balance. 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.
Apparatus: Waters Alliance (2695);
Analysis software: Waters, Empower Professional + GPC option;
Column used: manufactured by Tosoh Corporation, 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 further adjusting the pH to 6.0 with acetic acid was used;
Reference material for calibration curve: polyethylene glycol (peak top molecular weight (Mp) 272500, 219300, 107000, 50000, 24000, 12600, 7100, 4250, 1470);
Calibration curve: created 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, thiol-modified monomer 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 condition 1 (analysis of PAG)>
In the RI chromatogram, the flat and stable portions in the baseline immediately before and after elution were connected with straight lines, and peaks were detected and analyzed. When a multimer or an impurity was measured partially overlapping the target peak, the molecular weight of the target product was measured by vertically dividing at the most concave portion of the overlapping portion of the peak. The average number of added moles (number of repeating units) of alkylene oxide (AO) was calculated from the value of Mn.

<GPC analysis condition 3 (analysis of polymer: 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 that are thought to be derived from the thiol-modified monomer are measured partially overlapping the polymer peak, they are in the most concave part of the overlapping part of the polymer and the peak. The polymer part and the monomer part were separated by vertical division, 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)

<GPC analysis condition 4 (analysis of polymer: G-4)>
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 with a straight line, and the polymer was detected and analyzed. However, when low molecular weight peaks that are thought to be derived from monomers, dimers, thiol-modified monomers, etc. are partially overlapped with the polymer peaks, they are perpendicular to the most concave portion of the overlapping portion of the polymer and those. The polymer part and the monomer part were separated by division, 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, analysis was performed by appropriately changing the conditions of the LC column, eluent, and the like.
Apparatus: Waters Alliance (2695);
Analysis software: Emper Professional + GPC option from Waters;
Column: GL Science Inertsil ODS-2 guard column + column (inner diameter 4.6 mm × 250 mm × 3);
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996);
Eluent: A solution adjusted to pH 4.0 by adding 30% NaOH aqueous solution to a mixture of acetonitrile / 100 mM acetate ion exchange aqueous solution = 40/60 (mass%);
Flow rate: 0.6 mL / min;
Column temperature: 40 ° C .;
Measurement time: 90 minutes;
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 thiol-modified monomer 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-1 to G-3) is shown in Table 2.

In Table 2, “PEG” means polyethylene glycol. Further, “(EO) / (AO) wt” means a mass ratio of ethylene oxide in 100% by mass of all alkylene oxides constituting PAG.
In Table 2, No. G-1 PAG was 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.

Examples P1, P3, P5 and P6
(Thiol-modified monomer)
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. The thiol-modified monomer was prepared at a predetermined reaction temperature and reaction time. In Table 4-2, “-” means that the corresponding raw material was not added or the corresponding organic residue does not exist.
The production method 2 in Table 4-1 is as follows.

<Production method 2>
(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 adding cyclohexane in the middle so that the temperature in the reaction system would be 110 ± 5 ° C.
The reaction time was determined based on the theoretical dehydration amount and LC and GPC analysis results.
(2) Solvent removal 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 30% aqueous NaOH solution was quickly charged into the reactor. Next, this reaction solution was allowed to cool to room temperature, and the reaction crude product was solidified and filtered to obtain a solidified product. About 1.5 times as much diethyl ether as the volume ratio was added to the solidified product and stirred for 30 minutes, followed by suction filtration to obtain a powder. At this time, attention was paid so that the solidified product was not completely dried. Furthermore, the obtained powder was washed twice or more in the same procedure. The washed powder was dissolved in about the same weight of water and the concentration was adjusted to 50%. Subsequently, the remaining diethyl ether was distilled off at room temperature of 100 Torr to obtain an aqueous solution of the thiol-modified monomer of the present invention.
(3) ¹ H-NMR analysis A part of the sample after the esterification step of PAG thiol (thiol-modified monomer) 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.

For Examples P1, P3, P5 and P6, the total esterification rate of the reaction crude product after the esterification step and the diester / total ester were analyzed. Further, the total esterification rate of the thiol-modified monomer obtained after the solvent removal step and the diester / total ester were analyzed. The results are shown in Table 4-3.

From the results of Examples P1, P3, P5 and P6, it was found that a high molecular weight thiol-modified monomer can be obtained by the production method of the present invention.

Examples F10-F51, L1-L6
(Polyalkylene glycol chain-containing thiol polymer)
Next, using the thiol-modified monomers obtained in Examples P1, P3, P5 and P6, (meth) acrylic acid as an unsaturated carboxylic acid monomer and unsaturated (poly) alkylene glycol system Examples of the polymer of the present invention obtained by polymerizing a polyalkylene ethylene glycol monomer (hereinafter also referred to as “PEG monomer”) as a monomer will be described.

Examples F10-F51
Polymers were synthesized under the polymerization conditions described in Tables 5-1 to 5-2 and Tables 6-1 to 6-2. The analysis results for each polymer are as described in Tables 5-1 to 5-2.
In these examples, the composition of the polymer is expressed by a mass ratio in terms of SMAA (when the unsaturated carboxylic acid monomer is completely neutralized with NaOH). Therefore, the total is not 100%.

The production methods F-1 to F-3 in the table are 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.

<Method F-2>
As the monomer solution, an aqueous solution of a predetermined amount of monomer and sodium hydroxide was prepared. A predetermined amount of PAG thiol aqueous solution was prepared as a chain transfer agent solution. 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, the chain transfer agent solution over 3.5 hours, and the initiator solution over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining 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.

<Method F-3>
As the monomer solution, an aqueous solution of a predetermined amount of monomer and sodium hydroxide was prepared. A predetermined amount of an aqueous solution of PAG thiol was prepared as a chain transfer agent solution. A predetermined amount of an aqueous initiator solution was prepared as an initiator solution.
The monomer solution was charged into a glass reaction apparatus and heated to a predetermined temperature while stirring. Subsequently, the chain transfer agent solution and the initiator solution were all added to the reactor, mixed uniformly, and then held at a predetermined temperature for a predetermined time to complete the reaction. After cooling to room temperature, a 30% aqueous NaOH solution was added as necessary to adjust the pH to obtain an aqueous polymer solution.

Examples L1-L6
Polymers were synthesized under the polymerization conditions described in Tables 7 and 8. The analysis results for each polymer are as described in Table 7.
In these examples, the composition of the polymer is represented by a mass ratio in terms of SAA (when the unsaturated carboxylic acid monomer is completely neutralized with NaOH). Therefore, the total is not 100%.

Moreover, the manufacturing method I-2 in a table | surface is as follows.

<Production method I-2>
A predetermined amount of monomer aqueous solution was prepared as the monomer solution. A predetermined amount of PAG thiol solution was prepared. A predetermined amount of an aqueous initiator solution was prepared as an initiator solution.
A predetermined amount of monomer and water are charged into a glass reactor equipped with a Dimroth condenser, a Teflon (registered trademark) stirrer and a stirrer with a stirrer, a nitrogen gas inlet tube, and a temperature sensor, at 300 rpm. While stirring, nitrogen gas was introduced at 100 to 200 mL / min and heated to a predetermined temperature. Subsequently, a predetermined amount of the monomer solution, the PAG thiol solution, and the initiator solution were dropped into the reactor over a predetermined time. After completion of the dropping, the polymerization reaction was completed by maintaining 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 manufacturing method F-1 to F-3 and manufacturing method I-2 mentioned above was as follows.
The PAG thiol having a polymer moiety bonded to both ends of the polyalkylene glycol chain (1) via a sulfur atom-containing group is used in addition to the compound obtained in Example P1. Having a carboxyl group derived from an unsaturated carboxylic acid monomer (methacrylic acid) and a polyalkylene glycol chain (2) derived from an unsaturated (poly) alkylene glycol monomer (methoxypolyethylene glycol methacrylate) A polymer (i) having (iii) as a main component and having a polymer portion (the same structure as described above) bonded to one end of the polyalkylene glycol chain (1) via a sulfur atom-containing group; and a polyalkylene glycol chain (1) Constituent unit having a polymer site (similar structure as described above) bonded to one end via a sulfur atom-containing group And a polymer (iv) having a polyalkylene glycol chain (1) bonded via a sulfur atom-containing group to both ends of a polymer site (same structure as described above). A mixture containing a small amount.
About what used the compound obtained in Example P1 as PAG thiol, it was a mixture which has a polymer (i) as a main component and contained a small amount of polymers (ii), (iii), and (iv).

Comparative Examples F1-F4, L1-L4, Reference Examples L5-L6
(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.

Comparative Examples F1-F4
Polymers were synthesized under the polymerization conditions described in Tables 9-1 to 9-2. The analysis results for each polymer are as described in Table 9-1.

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 is composed of a carboxyl group derived from an unsaturated carboxylic acid monomer (methacrylic acid) and a polyalkylene glycol chain derived from an unsaturated (poly) alkylene glycol monomer (methoxypolyethylene glycol methacrylate) (2 ) But no polyalkylene glycol chain (1).

Comparative Examples L1-L4 and Reference Examples L5-L6
Polymers were synthesized under the polymerization conditions described in Tables 10-1 to 10-2. The analysis results for each polymer are as described in Table 10-1.

In these tables, the composition of the polymer is expressed as a mass ratio in terms of SAA (when the unsaturated carboxylic acid monomer is completely neutralized with NaOH).

The production method I-3 in the table is as follows.
<Production method I-3>
A predetermined amount of monomer aqueous solution was prepared as the monomer solution. A predetermined amount of an initiator aqueous solution was prepared as a reactor charging initiator solution. A predetermined amount of an initiator / transfer agent aqueous solution was prepared as a dripping initiator / chain transfer agent solution.
Dimroth condenser, Teflon (registered trademark) stirrer and stirrer with stir seal, nitrogen gas inlet tube, glass reactor equipped with temperature sensor are charged with a predetermined amount of monomer and water and stirred at 200 rpm Then, the mixture was heated to a predetermined temperature while introducing nitrogen gas at 100 to 200 mL / min. Next, the entire amount of a predetermined amount of H ₂ O ₂ aqueous solution was charged and heated to a predetermined temperature. Subsequently, a predetermined amount of the monomer solution was dropped into the reactor over 3 hours and the initiator / transfer agent solution over 3.5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining 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 is composed of an unsaturated carboxylic acid monomer (acrylic acid) -derived carboxyl group and an unsaturated (poly) alkylene glycol monomer (3-methyl-3-buten-1-ol). The polymer has a polyalkylene glycol chain (2) derived from an ethylene oxide (EO) adduct) but does not have a polyalkylene glycol chain (1).

(Dispersant, cement admixture)
Test Examples 1-50, 73-76
Next, Test Examples 1 to 50 and 73 to 76 in which the dispersion performance of the polymer of the present invention obtained in Examples and the comparative polymer obtained in Comparative Examples were evaluated will be described.

<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 the ion exchange aqueous solution W of the polymer of the present invention or the comparative polymer and the antifoaming agent, the addition amount of the polymer aqueous solution shown in Tables 11-1 to 11-3 was weighed out, and the antifoaming agent MA-404 (Pozoris product) 10% by mass with respect to the solid content of the polymer was added, and ion-exchanged water was further added to obtain a predetermined amount, which was sufficiently uniformly dissolved. In Tables 11-1 to 11-3, the addition amount of the polymer is represented by weight% 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, after kneading for 30 seconds in duplicate, 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 container 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 with a stick with a turn, and stuffed the mortar until the flow cone was filled, and struck with a stick with a turn 15 times. Finally, I made up the shortage and smoothed the surface of the flow cone. 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 in two places, and the average value is zero. 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.

<Method of measuring the amount of mortar air>
About 200 mL of mortar was packed in a 500 mL glass graduated cylinder, struck with a round bar having a diameter of 8 mm, and gently bubbled by hand to remove coarse bubbles. Further, about 200 mL of mortar was added and air bubbles were similarly removed. Then, the volume and weight of the mortar were measured, and the amount of air was calculated from the density of each material.

In Tables 11-1 to 11-3, “actual” means an example corresponding to an example, and “ratio” means an example corresponding to a comparative example. The same applies to the following tables.

As is apparent from Tables 11-1 to 11-3, the mortar using the polymer of the present invention contains a polymer compound compared to a mortar using a comparative polymer which is a conventional copolymer for cement admixture. When the amount is the same, a higher 15-stroke mortar flow value is shown. Even when the amount of the polymer blended is small, a 15-stroke mortar flow value of the same level or more is shown. In other words, a larger amount of polymer is required for the mortar using the comparative polymer to exhibit a 15-stroke mortar flow value comparable to that of the mortar using the polymer of the present invention. Therefore, it can be seen that the polymer of the present invention exhibits better dispersion performance than the comparative polymer.
Table 11-3 shows the results of measuring the mortar fluidity retention over time (hereinafter sometimes simply referred to as “retention”) of the kneaded mortar for a predetermined time. As is apparent from Table 11-3, the polymer of the present invention not only has a low blending amount because of its high initial dispersion performance, but also exhibits the same or higher retention as compared with the comparative polymer. It can be seen that it has both high dispersibility and retention.

Claims (9)

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 80 to 500. R ³ represents a hydrogen atom or an organic residue.) A thiol-modified monomer having a structure represented by body. The oxyalkylene group represented by AO contains 75% by mass or more of oxyethylene groups with respect to 100 mol% of all oxyalkylene groups constituting the oxyalkylene chain represented by-(AO) n-. The thiol-modified monomer according to claim 1. The thiol-modified monomer according to claim 1 or 2, wherein the oxyalkylene group represented by AO occupies 50% by mass or more in 100% by mass of the thiol-modified monomer. The thiol-modified monomer according to any one of claims 1 to 3, wherein the thiol-modified monomer contains an antioxidant in an amount of 10 to 5000 ppm by mass. A method for producing the thiol-modified monomer according to claim 1,
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 polyalkylene glycol. An unsaturated monomer containing an unsaturated carboxylic acid monomer and / or an unsaturated (poly) alkylene glycol monomer in the presence of the thiol-modified monomer according to any one of claims 1 to 4. A polyalkylene glycol chain-containing thiol polymer obtained by polymerizing components. A dispersant comprising the polyalkylene glycol chain-containing thiol polymer according to claim 6. A cement admixture comprising the thiol-modified monomer according to any one of claims 1 to 4 and / or the polyalkylene glycol chain-containing thiol polymer according to claim 6. A cement composition comprising a cement and the thiol-modified monomer according to any one of claims 1 to 4 and / or the polyalkylene glycol chain-containing thiol polymer according to claim 6. .