JP2021098778A - Method for producing an additive for hydraulic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent blockage of a pipe due to gelation in an esterification step, and to prevent deterioration of the performance of a polyether ester monomer due to gelation or the like, so that the stability of the polyether ester monomer during storage is high. Moreover, a method for producing a high-performance additive for a water-hard composition at low cost is provided. SOLUTION: An unsaturated carboxylic acid and a specific one-ended blockage polyalkylene glycol are allowed to exist in the absence of a solvent, and an acid catalyst, a polymerization inhibitor A, a polymerization inhibitor B and a polymerization inhibitor C. Step 1 to obtain a polyether ester monomer by an esterification reaction under heating and reduced pressure conditions, and the obtained polyether ester monomer can be copolymerized with the polyether ester monomer. A method for producing an additive for a water-hard composition, which undergoes a step 2 of radical copolymerizing a vinyl monomer in an aqueous solvent. [Selection diagram] None

Description

The present invention relates to a method for producing an additive for a hydraulic composition. More specifically, in the esterification step, it is possible to prevent blockage of the pipe due to gelation and the like and deterioration of the performance of the polyether ester monomer as an intermediate raw material, and the stability of the polyether ester monomer during storage is high. Moreover, the present invention relates to a method for producing an additive for a water-hard composition, which produces an additive for a water-hard composition at low cost and with high performance.

Conventionally, as an additive for a hydraulic composition, which can impart excellent fluidity with less slump loss to the hydraulic composition and sufficiently secure the compressive strength of the cured product obtained by curing the hydraulic composition, it is water-soluble. Vinyl copolymers are known.

In order for the water-soluble vinyl copolymer to exhibit excellent performance as an additive for a water-hard composition, it is necessary to improve the quality of the polyether ester monomer as an intermediate raw material.

As a means for improving the quality of the polyether ester monomer, a single-ended polyalkylene glycol as a raw material whose acetic acid-equivalent concentration of residual free acid is adjusted to a certain value or less by purification treatment is used as a solvent. In the absence of p-benzoquinone and / or phenothiazine, a high-quality polyether ester monomer is obtained by subjecting a one-terminal substituted polyalkylene glycol to an unsaturated carboxylic acid in an esterification reaction. Then, it has been proposed to radically polymerize the polyether ester monomer and the vinyl monomer to produce a water-soluble vinyl copolymer (see Patent Document 1).

JP-A-2002-265594

However, in the technique disclosed in Patent Document 1, in the esterification step, gel is generated due to gelation, the pipe is clogged, and the performance of the polyether ester monomer is deteriorated due to gelation or the like, resulting in poly. There is a problem that the stability of the ether ester monomer during storage is low and the performance of the obtained additive for the water-hard composition is also low.

Therefore, the problem to be solved by the present invention is to prevent blockage of the pipe due to gelation in the esterification step, and there is no deterioration in the performance of the polyether ester monomer due to gelation or the like. It is an object of the present invention to provide a method for producing a high-performance additive for a water-hard composition, which is highly stable during storage of the body and at low cost.

As a result of research to solve the above problems, the present inventors have found that in the esterification step of unsaturated carboxylic acid and one-ended closed polyalkylene glycol, in the presence of an acid catalyst and a specific polymerization inhibitor, no solvent is used. It has been found that a production method that goes through the step 1 of esterification in the presence and the step 2 of radically polymerizing the polyether ester monomer and the vinyl monomer obtained in the step 1 is suitable. According to the present invention, the following method for producing an additive for a hydraulic composition is provided.

[1] A method for producing an additive for a hydraulic composition, which undergoes the following steps 1 and 2 below.
Step 1: An unsaturated carboxylic acid and a one-ended closed polyalkylene glycol represented by the following general formula (1) are subjected to an acid catalyst, a polymerization inhibitor A, a polymerization inhibitor B and a polymer-inhibiting agent B in the absence of a solvent. A step of obtaining a polyether ester monomer by an esterification reaction under heating and reduced pressure conditions in the presence of a polymerization inhibitor C.

（一般式（１）中、Ｒ^１は炭素数１〜２２のアルキル基又は炭素数６〜３０の芳香族基を表し、ＡＯは炭素数２又は３のオキシアルキレン基を表し、ｎは１〜３００の整数を表す。）
重合禁止剤Ａ：２５℃の蒸気圧が０．０１Ｐａ以上のリン原子未含有の重合禁止剤
重合禁止剤Ｂ：２５℃の蒸気圧が０．０１Ｐａ未満のリン原子未含有の重合禁止剤
重合禁止剤Ｃ：リン原子含有重合禁止剤
工程２：前記工程１で得られたポリエーテルエステル単量体と、当該ポリエーテルエステル単量体と共重合可能なビニル単量体と、を水溶媒中でラジカル共重合させて水硬性組成物用添加剤を得る工程

(In the general formula (1), R ¹ represents an alkyl group having 1 to 22 carbon atoms or an aromatic group having 6 to 30 carbon atoms, AO represents an oxyalkylene group having 2 or 3 carbon atoms, and n represents 1 to 1. Represents an integer of 300.)
Polymerization inhibitor A: A phosphorus atom-free polymerization inhibitor having a vapor pressure of 25 ° C. of 0.01 Pa or more Polymerization inhibitor B: A phosphorus atom-free polymerization inhibitor having a vapor pressure of less than 0.01 Pa at 25 ° C. Agent C: Phosphorus atom-containing polymerization inhibitor Step 2: The polyether ester monomer obtained in the above step 1 and a vinyl monomer copolymerizable with the polyether ester monomer are mixed in an aqueous solvent. Step of radical copolymerization to obtain an additive for a water-hard composition

[2] The method for producing an additive for a hydraulic composition according to the above [1], wherein the unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid and methacrylic acid.

[3] The method for producing an additive for a hydraulic composition according to the above [1] or [2], wherein the polymerization inhibitor A contains at least one selected from the group consisting of parabenzoquinone, naphthoquinone and quinhydrin.

[4] The method for producing an additive for a hydraulic composition according to any one of the above [1] to [3], wherein the polymerization inhibitor A contains parabenzoquinone.

[5] The method for producing an additive for a hydraulic composition according to any one of the above [1] to [4], wherein the polymerization inhibitor B contains phenothiazine.

[6] The addition for a water-hard composition according to any one of the above [1] to [5], wherein the polymerization inhibitor C contains at least one selected from the group consisting of phosphorous acid and phosphorous acid ester. Method of manufacturing the agent.

[7] The addition ratio of the polymerization inhibitor A is 0.01 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol.
The addition ratio of the polymerization inhibitor B was 0.005 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol.
The addition for a water-hard composition according to any one of the above [1] to [6], wherein the addition ratio of the polymerization inhibitor C is 0.05 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol. Method of manufacturing the agent.

[8] The one-ended closed polyalkylene glycol has an AO in the general formula (1) of 95 mol% or more of all oxyalkylene groups being an oxyethylene group having 2 carbon atoms [1] to [7]. The method for producing an additive for a water-hard composition according to any one of.

According to the method for producing an additive for a water-hard composition of the present invention, in the esterification step, blockage of the pipe due to gelation is prevented, and the performance of the polyether ester monomer is not deteriorated due to gelation or the like. There is an effect that the obtained additive for a water-hard composition is highly stable during storage and that a high-performance additive for a water-hard composition can be produced at low cost.

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. Therefore, it should be understood that the following embodiments can be appropriately modified, improved, or the like based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. In the following examples and the like, unless otherwise specified,% means mass% and parts means parts by mass.

The method for producing an additive for a hydraulic composition of the present embodiment goes through step 1 and step 2. First, step 1 will be described. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, and crotonic acid, and in particular, at least one selected from the group consisting of acrylic acid and methacrylic acid is preferable.

The one-ended sealed polyalkylene glycol is represented by the following general formula (1).

In the general formula (1), R ¹ is an alkyl group having 1 to 22 carbon atoms or an aromatic group having 6 to 30 carbon atoms. Examples of such an alkyl group having 1 to 22 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group and an octadecyl group. Examples thereof include an eikosanyl group and a docosanyl group. Examples of such aromatic groups having 6 to 30 carbon atoms include a phenyl group, a naphthyl group, a benzyl group, an anthracenyl group, a pyrenyl group, a naphthopylenyl group, a methylnaphthyl group, an ethylnaphthyl group, a propylnaphthyl group and a butylnaphthyl group. , Pentylnaphthyl group, hexylnaphthyl group, heptylnaphthyl group, octylnaphthyl group, nonylnaphthyl group, decylnaphthyl group, undecylnaphthyl group, dodecylnaphthyl group, tridecylnaphthyl group, tetradecylnaphthyl group, pentadecylnaphthyl group, hexa Examples thereof include a decylnaphthyl group, a heptadecylnaphthyl group, an octadecylnaphthyl group, a (mono, di or tri) styrylphenyl group, a cumyl group, a (mono, di or tri) benzylphenyl group, a diphenyl group and the like.

AO is an oxyalkylene group having 2 or 3 carbon atoms. Examples of such an oxyalkylene group include an oxyethylene group and an oxypropylene group. In the case of two or more kinds of oxyalkylene groups, any addition form such as random addition, block addition, alternating addition and the like may be used. n is an integer from 1 to 300. It is preferable that 95 mol% or more of the total oxyalkylene group is an oxyethylene group having 2 carbon atoms.

Examples of the one-ended closed polyalkylene glycol represented by the general formula (1) include methoxypolyethylene glycol, methoxypolyethylene glycol polypropylene glycol, ethoxypolyethylene glycol, ethoxypolyethylene glycol polypropylene glycol, propoxypolyethylene glycol, and propoxypolyethylene glycol polypropylene. Glycol, Butoxy Polyethylene Glycol, Butoxy Polyethylene Glycol Polypropylene Glycol, Lauryl Oxyethylene Glycol, Lauryl Oxyethylene Glycol Polypropylene Glycol, benzyl Oxy Polyethylene Glycol, benzyl Oxy Polyethylene Glycol Polypropylene Glycol, Phenoxy Polyethylene Glycol, Phenoxy Polyethylene Glycol Polypropylene Glycol, Alkyl Phenoxy Polyethylene Glycol , Alkylphenoxypolyethylene glycol polypropylene glycol, (mono, di or tri) styrylphenoxypolyethylene glycol, (mono, di or tri) styrylphenoxypolyethylene glycol polypropylene glycol and the like.

In the present embodiment, the one-ended closed polyalkylene glycol represented by the general formula (1) and the unsaturated carboxylic acid are mixed with an acid catalyst, a polymerization inhibitor A, a polymerization inhibitor B and an unsaturated carboxylic acid in the absence of a solvent. Under heating and reduced pressure conditions in which the polymerization inhibitor C is present, an esterification reaction is carried out while distilling off the produced water using an acid catalyst to obtain a polyether ester monomer.

The polymerization inhibitor A is a phosphorus atom-free (that is, phosphorus atom-free) polymerization inhibitor having a vapor pressure of 0.01 Pa or more at 25 ° C. Examples of such a polymerization inhibitor A include parabenzoquinone (vapor pressure at 25 ° C.: 13 Pa), naphthoquinone (vapor pressure at 25 ° C.: 0.0225 Pa), and quinhydrin (vapor pressure at 25 ° C.: 13 Pa). And a 1: 1 mixture with hydroquinone having a vapor pressure of 0.0893 Pa at 25 ° C.) and the like. In particular, parabenzoquinone is preferred.

The polymerization inhibitor B is a phosphorus atom-free (that is, phosphorus atom-free) polymerization inhibitor having a vapor pressure of less than 0.01 Pa at 25 ° C. Examples of such a polymerization inhibitor B include phenothiazine (vapor pressure at 25 ° C.: 0.000119 Pa) and the like.

The polymerization inhibitor C is a phosphorus atom-containing polymerization inhibitor, that is, a phosphorus atom-containing polymerization inhibitor. Examples of such a polymerization inhibitor C include phosphorous acid, phosphorous acid ester and the like. Examples of the phosphite ester include tributyl phosphite and triphenyl phosphite.

The abundance of the polymerization inhibitor A in the reaction system is preferably an amount corresponding to 0.01 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol represented by the general formula (1). More preferably, it is an amount corresponding to 06 to 0.45% by mass. When the abundance of the polymerization inhibitor A in the reaction system is less than the amount corresponding to 0.01% by mass with respect to the one-ended closed polyalkylene glycol represented by the general formula (1), the gel in the piping or vaporized voids. There is a possibility that the effect of preventing polymerization is not fully exhibited. If the amount is more than 0.5% by mass, the obtained polyether ester monomer is used as an intermediate raw material in step 2 to produce a vinyl copolymer as an additive for a water-hard composition. At that time, the radical copolymerization reaction may not proceed smoothly.

The abundance of the polymerization inhibitor B in the reaction system is preferably an amount corresponding to 0.005 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol represented by the general formula (1), and 0. The amount corresponding to 005 to 0.10% by mass is more preferable, and the amount corresponding to 0.005 to 0.05% by mass is most preferable. When the abundance of the polymerization inhibitor B in the reaction system is less than the amount corresponding to 0.005% by mass with respect to the one-ended closed polyalkylene glycol represented by the general formula (1), the effect of preventing gelation of the liquid portion is obtained. It may not be fully exerted. If the amount is more than 0.5% by mass, the radical copolymerization reaction is smoothly carried out when the obtained polyether ester monomer is used as an intermediate raw material in step 2 to produce a vinyl copolymer. It may not progress.

The abundance of the polymerization inhibitor C in the reaction system is preferably an amount corresponding to 0.005 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol represented by the general formula (1), and 0. More preferably, it is an amount corresponding to 05 to 0.3% by mass. When the abundance of the polymerization inhibitor C in the reaction system is less than the amount corresponding to 0.005% by mass with respect to the one-ended closed polyalkylene glycol represented by the general formula (1), the effect of preventing gelation of the liquid portion is obtained. It may not be fully exerted. If the amount is more than 0.5% by mass, the radical copolymerization reaction is smoothly carried out when the obtained polyether ester monomer is used as an intermediate raw material in step 2 to produce a vinyl copolymer. It may not progress.

The heating conditions during the esterification reaction are preferably 105 to 140 ° C., and the pressure conditions are preferably 15 to 0.5 kPa. Under such heating conditions, it is preferable to raise the temperature gradually or stepwise to the above temperature range. Further, it is more preferable that the pressure is gradually or gradually reduced (that is, reduced in pressure) within the above pressure range.

In the esterification reaction, an acid catalyst is used as a catalyst. As such an acid catalyst, for example, sulfuric acid, p-toluenesulfonic acid, phosphoric acid, methanesulfonic acid and the like can be used alone or in combination. The amount of the acid catalyst used is preferably 1 to 50 mol% with respect to the one-ended closed polyalkylene glycol represented by the general formula (1).

In the esterification reaction, the raw material ratio (molar ratio) of the one-ended closed polyalkylene glycol represented by the general formula (1) to the unsaturated carboxylic acid is the one-ended closed polyalkylene glycol / unsaturated represented by the general formula (1). Saturated carboxylic acid = 1 / 1.5 to 1/8 (molar ratio) is preferable. After the esterification reaction, the excess unsaturated carboxylic acid may be distilled off, or the unsaturated carboxylic acid may be used in step 2 while remaining. When the unsaturated carboxylic acid is used in the step 2 while remaining, the excess amount of the unsaturated carboxylic acid can be quantified by various analyzes, and the polymerization can be carried out in the step 2 at a desired compounding ratio. As the analysis method, various chromatographies and acid values can be used. The esterification rate after completion of the esterification reaction can be analyzed by a known method. For example, analysis can be performed by a method using various chromatographies or a method of measuring the hydroxyl value (JIS K 0070).

Next, step 2 will be described. The polyether ester monomer obtained in step 1 and a vinyl monomer copolymerizable therewith are subjected to a radical copolymerization reaction in an aqueous solvent. Examples of the vinyl monomer copolymerizable with the polyether ester monomer include (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, and mono-succinic acid (2- (meth) acryloyloxyethyl). ) And other unsaturated carboxylic acids and salts thereof, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) Decyl acrylate, dodecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, styrene, acrylamide, (meth) ) Acrylic acid and salts thereof are not particularly limited as long as they are copolymerizable vinyl monomers. Examples of the salt of each vinyl monomer include alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium salt and magnesium salt, ammonium salts, amine salts such as diethanolamine salt and triethanolamine salt, and the like. Can be mentioned.

The ratio of radical copolymerization of the polyether ester monomer and the vinyl monomer copolymerizable therewith is not particularly limited, but the polyether ester monomer, (meth) acrylic acid and / or its When a salt is subjected to a radical copolymerization reaction, 5 to 95% by mass of a polyether ester monomer, 5 to 95% by mass of (meth) acrylic acid and / or a salt thereof, and other copolymerizable single amounts. It is preferable that the body is 0 to 10% by mass (however, the total of these is 100% by mass).

As the radical copolymerization reaction, for example, a reaction as described in JP-A-8-290948 can be adopted. For example, an aqueous solution containing the polyether ester monomer obtained in step 1, a vinyl monomer copolymerizable therewith, and a chain transfer agent is prepared, and a radical initiator is added in a nitrogen gas atmosphere. A vinyl copolymer can be obtained by conducting a radical copolymerization reaction at a reaction temperature of 50 to 90 ° C. for 4 to 8 hours. In this case, the chain transfer agent includes a water-soluble chain transfer agent such as 2-mercaptoethanol, mercaptopropionic acid, and thioglycolic acid, as well as a water-insoluble chain transfer agent such as α-methylstyrene dimer and dodecanethiol. Can be mentioned. Further, as the radical initiator, a persulfate such as hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate and a water-soluble radical initiator such as 2,2'-azobis (2-aminodinopropane) dihydrochloride are started. Agents are mentioned. A reducing agent may be used to allow the radical initiator to act efficiently. Examples of the reducing agent include iron (II) sulfate / heptahydrate, L-ascorbic acid, sulfites, hydroxymethanesulfinic acid (salt), phosphinate and the like.

The vinyl copolymer obtained by the radical copolymerization reaction preferably has a mass average molecular weight (mass average molecular weight in terms of polyethylene glycol by the GPC method, hereinafter the same) of 3500 to 100,000, preferably 5000 to 40,000. It is more preferable to make it.

The vinyl copolymer obtained as described above is a hydraulic composition that can be used for various hydraulic cement compositions, typically mortar and concrete, in which a fine powder admixture is used as a binder in addition to cement or cement. It is a product additive. Examples of cement include various Portland cements such as ordinary Portland cement, early-strength Portland cement, and moderate heat Portland cement, and various mixed cements such as blast furnace cement, fly ash cement, and silica fume cement. Examples of the fine powder admixture include limestone powder, calcium carbonate, silica fume, blast furnace slag fine powder, and fly ash.

In the present embodiment, the amount of the additive for the hydraulic composition used is usually 0.01 to 2.5 mass in terms of solid content with respect to 100 parts by mass of the cement or the binder composed of the cement and the fine powder admixture. Parts, preferably 0.05 to 1.5 parts by mass. In the present embodiment, the additive for hydraulic composition is usually added together with kneading water when preparing the additive for hydraulic composition.

Test Category 1 (Preparation of one-ended closed polyalkylene glycol (PAG))
-Preparation of one-ended closed polyalkylene glycol (P-1) 240.3 g (2 mol) of diethylene glycol monomethyl ether was charged into an autoclave, and the inside of the autoclave was sufficiently replaced with nitrogen. After adding 3.6 g of a 28% sodium methoxide methanol solution as a catalyst, the reaction temperature was maintained at 110 to 120 ° C. with stirring, and 1760 g (40 mol) of ethylene oxide was press-fitted at a pressure of 0.4 MPa. , A ring-opening addition reaction was carried out. After the ring-opening addition reaction, the mixture was aged at the same temperature (the above reaction temperature) for 1 hour. Further, 0.72 g of 85% phosphoric acid was added, dehydrated under reduced pressure for 1 hour under heating at 110 ° C., cooled to 80 ° C., pressure-filtered in a nitrogen atmosphere, and one-ended sealed polyalkylene glycol (P) was used as a filtrate. -1) was obtained.

-Preparation of one-terminal polyalkylene glycol (P-4) 302.5 g of commercially available distyrene phenol was charged into an autoclave, 1.3 g of potassium hydroxide was added as a catalyst, and then the inside of the autoclave was sufficiently replaced with nitrogen. After dehydration under reduced pressure at 100 ° C. for 1 hour with stirring, the reaction temperature was maintained at 110 to 120 ° C., and 968 g of ethylene oxide was press-fitted at a pressure of 0.4 MPa to carry out a cycloaddition reaction. After the cycloaddition reaction is completed, the mixture is aged at the same temperature (the above reaction temperature) for 1 hour, 1.0 g of a silicic acid / aluminum oxide-based adsorbent (Kyowa Chemical Industry Co., Ltd.'s Kyoward 700SL) is added, and the pressure is reduced at 110 ° C. for 1 hour. After dehydration and cooling to 80 ° C., pressure filtration was performed in a nitrogen atmosphere. One-ended closed polyalkylene glycol (P-4-2) was obtained as a filtrate. Then, the one-ended closed polyalkylene glycol (P-1) and the one-ended blocked polyalkylene glycol (P-4-2) are mixed at a mass ratio of 90/10 to obtain the one-ended polyalkylene glycol (P-4). Obtained.

-Preparation of one-ended closed polyalkylene glycol (P-2), (P-3), (P-5), (P-6) One-ended closed polyalkylene glycol (P-1) in the same manner as one-ended blocked polyalkylene glycol (P-1). Sealing polyalkylene glycols (P-2), (P-3), (P-5), and (P-6) were prepared. The prepared one-ended closed polyalkylene glycol (PAG) is summarized in Table 1.

P-1 to P-6 in Table 1 will be described below.
P-1: Polyoxyethylene (n = 22) monomethyl ether P-2: Polyoxyethylene (n = 9) monomethyl ether P-3: Polyoxyethylene (n = 45) Monomethyl ether P-4: Polyoxyethylene ( Mix of n = 22) monomethyl ether and polyoxyethylene (n = 22) mono (distyrene phenyl) ether Mass ratio 90/10
P-5: Polyoxyethylene (n = 68) monomethyl ether P-6: Polyoxyethylene (n = 21) oxypropylene (n = 1) monomethyl ether

Test Category 2 (Preparation of Polyether Ester Monomer)

Example 1 (Preparation of Polyether Ester Monomer (MM-1))
In a 1 L glass reaction vessel, 600.0 g (0.6 mol) of one-ended sealed polyalkylene glycol (P-1) prepared in Test Category 1, 155.0 g (1.8 mol) of methacrylic acid, and parabenzoquinone. (Vapor pressure at 25 ° C. 13 Pa) 1.2 g, phenothiazine (vapor pressure at 25 ° C. 0.000119 Pa) 0.06 g, triphenyl phosphite 0.72 g, methanesulfonic acid 5.8 g (0.06 mol) were charged. The temperature is gradually raised and the pressure is reduced while stirring, and the water produced by the esterification reaction is distilled off from the reaction system as a water / methacrylic acid azeotropic mixture under the conditions of a temperature of 120 ° C. and a pressure of 1.5 kPa. The esterification reaction was carried out for 6 hours. After completion of the reaction, methacrylic acid was distilled off and the product was analyzed to obtain a polyether ester monomer (MM-1) having an esterification reaction rate of 98%.

-Examples 2 to 11 (preparation of polyether ester monomers (MM-2) to (MM-11))
Examples 2 to 11 (polyether ester monomer (MM-2)) are the same as in Example 1 (polyether ester monomer (MM-1)) except that the changes are shown in Table 2. ~ (MM-11)) was prepared.

Comparative Example 1 (Preparation of Polyether Ester Monomer (RM-1))
In a reaction vessel, 600.0 g (0.6 mol) of one-ended sealed polyalkylene glycol (P-1) prepared in Test Category 1, 155.0 g (1.8 mol) of methacrylate, and parabenzoquinone (vapor at 25 ° C.) Pressure 13 Pa) 1.0 g, concentrated sulfuric acid 5.7 g was charged, the temperature was gradually raised while stirring, and the pressure was reduced, and the water produced by the esterification reaction was distilled off from the reaction system as a water / methacrylic acid azeotropic mixture. The esterification reaction was carried out for 5 hours under the conditions of a temperature of 130 ° C. and a pressure of 1.0 kPa. After completion of the reaction, methacrylic acid was distilled off and the product was analyzed. As a result, it was a polyether ester monomer (RM-1) having an esterification reaction rate of 97%.

Comparative Example 2 (Preparation of Polyether Ester Monomer (RM-2))
In the reaction vessel, 600.0 g (0.6 mol) of one-ended closed polyalkylene glycol (P-1) prepared in Test Category 1, 155.0 g (1.8 mol) of methacrylic acid, and triphenyl phosphite 0. 72 g and 5.7 g of concentrated sulfuric acid were charged, and the temperature was raised while stirring to carry out the esterification reaction, but the esterification reaction was interrupted because a large amount of insoluble gel was precipitated on the way.

Comparative Example 3 (Preparation of Polyether Ester Monomer (RM-3))
In the reaction vessel, 600.0 g (0.6 mol) of one-ended sealed polyalkylene glycol (P-1) prepared in Test Category 1, 155.0 g (1.8 mol) of methacrylate, and phenothiazine (vapor pressure at 25 ° C.). 0.000119Pa) 0.06g and 5.7g of concentrated sulfuric acid were charged, and the temperature was gradually raised and reduced with pressure while stirring, and the water produced by the esterification reaction was distilled off from the reaction system as a water / methacrylic acid azeotropic mixture. While doing so, the esterification reaction was carried out under the conditions of a temperature of 130 ° C. and a pressure of 2.0 kPa for 7 hours. After completion of the reaction, methacrylic acid was distilled off and the product was analyzed. As a result, it was a polyether ester monomer (RM-3) having an esterification reaction rate of 98%.

-Comparative Examples 4 to 8 (Preparation of Polyether Ester Monomers (RM-4) to (RM-8))
Comparative Example 1 (polyether ester monomer (RM-1)) except that the amounts of one-terminal polyalkylene glycol species and unsaturated carboxylic acid, and the types and amounts of polymerization inhibitors were changed as shown in Table 2. In the same manner as above, the polyether ester monomers (RM-4) to (RM-8) of Comparative Examples 4 to 8 were prepared.

The contents of the prepared polyether ester monomers (MM-1) to (MM-11) and (RM-1) to (RM-8) are summarized in Tables 2 and 3.

Q-1 and the like in Table 2 will be described below.
Mass% with respect to P: Amount of polymerization inhibitor used with respect to one-ended closed polyalkylene glycol (mass%)
Ratio of acid catalyst (mol%): Amount of acid catalyst used relative to the total amount of one-ended closed polyalkylene glycol and unsaturated carboxylic acid (mol%)
Q-1: Methacrylic acid Q-2: Acrylic acid S-1: Methanesulfonic acid S-2: Paratoluenesulfonic acid S-3: A mixture of paratoluenesulfonic acid and sulfuric acid (1: 1 in molar ratio)
S-4: Sulfuric acid A-1: Parabenzoquinone (vapor pressure at 25 ° C. 13 Pa)
A-2: Naphthoquinone (vapor pressure 0.0225 Pa at 25 ° C)
A-3: A 1: 1 mixture of quinhydrin (parabenzoquinone with a vapor pressure of 13 Pa at 25 ° C and hydroquinone with a vapor pressure of 0.0893 Pa at 25 ° C))
B-1: Phenothiazine (vapor pressure at 25 ° C. 0.000119 Pa)
C-1: Triphenyl phosphite C-2: C-3 phosphite: Tributyl phosphite

In Table 3, the "sieving residue" is a sample obtained by placing 600 g of the polyether ester monomer immediately after the esterification reaction and 600 g of the polyether ester monomer in a 1 L polypropylene container, sealing the mixture, and storing the sample in an incubator at 60 ° C. for 2 weeks. Measured and evaluated. The measurement was performed using a JIS test sieve (stainless steel) with a nominal opening of 300 μm. All the samples in the polypropylene container were passed through this sieve, the residual amount remaining on the sieve was measured, and the residue ratio was calculated.

The sieving residue was determined based on the calculated residue ratio and based on the following criteria.
A: Less than 1% B: Less than 1-3% C: 3% or more

Test Category 3 (Preparation of Vinyl Copolymer as Additive for Hydraulic Composition)

The mass average molecular weight of the copolymer shown below was measured by gel permeation chromatography under the following measurement conditions.
<Measurement conditions>
Equipment: Shodex GPC-101 (manufactured by Showa Denko KK)
Column: OHpak SB-G + SB-806M HQ + SB-806M HQ (manufactured by Showa Denko KK)
Detector: Differential Refractometer (RI)
Eluent: 50 mM sodium nitrate aqueous solution Flow rate: 0.7 mL / min Column temperature: 40 ° C
Sample concentration: Eluent solution with sample concentration of 0.5% by weight Standard substance: Polyethylene oxide, polyethylene glycol

Example 12 (Preparation of vinyl copolymer (PC-1))
153.8 g of ion-exchanged water was added to a 1 L glass reaction vessel, and the atmosphere was replaced with nitrogen while stirring. The temperature of the reaction system was kept at 65 ° C. in a warm water bath under a nitrogen atmosphere, and 345.2 g of the polyether ester monomer (MM-1) obtained in Test Category 2, 39.5 g of methacrylic acid, and 3-mercaptopropion were obtained. A solution of 3.4 g of acid and 272.3 g of water was added dropwise over 2 hours. At the same time, 55.8 g of a 10% aqueous solution of sodium persulfate was added dropwise over 3 hours to carry out the polymerization. Then, the polymerization reaction was continued for 1 hour at 65 ° C. to complete the polymerization, and after cooling, a 30% aqueous sodium hydroxide solution was added so as to have a pH of 6, diluted with ion-exchanged water, and the concentration of the vinyl copolymer was 40%. An aqueous solution was obtained. When this vinyl copolymer was analyzed under the above-mentioned measurement conditions, it was a vinyl copolymer (PC-1) having a mass average molecular weight of 23100.

Example 13 (Preparation of vinyl copolymer (PC-2))
153.8 g of ion-exchanged water was charged into a 1 L glass reaction vessel, dissolved uniformly with stirring, and then the atmosphere was replaced with nitrogen. The temperature of the reaction system was kept at 70 ° C. in a warm water bath under a nitrogen atmosphere, and 329.5 g of the polyether ester monomer (MM-2) obtained in Test Category 2, 36.6 g of acrylic acid, and hydroxyethyl acrylate were obtained. A solution of 19.2 g, 3.8 g of 3-mercaptopropionic acid and 273.1 g of ion-exchanged water was added dropwise to the reaction vessel over 4 hours. At the same time, 55.8 g of a 10% aqueous solution of sodium persulfate was added dropwise over 5 hours for polymerization, and the mixture was aged at the same temperature (70 ° C.) for 1 hour to complete the polymerization reaction. After cooling, a 30% aqueous sodium hydroxide solution was added so as to have a pH of 5, and the mixture was further diluted with ion-exchanged water to obtain an aqueous solution having a vinyl copolymer concentration of 40%. When this vinyl copolymer was analyzed, it was a vinyl copolymer (PC-2) having a mass average molecular weight of 20500.

Example 14 (Preparation of vinyl copolymer (PC-3))
In the reaction vessel, 148.1 g of the polyether ester monomer (MM-3) obtained in Test Category 2, 30.0 g of methacrylic acid, 9.4 g of methyl acrylate, 4.1 g of 3-mercaptopropionic acid and ion-exchanged water 181 After charging 0.0 g and uniformly dissolving the mixture with stirring, the atmosphere was replaced with nitrogen. In a nitrogen atmosphere, the temperature of the reaction system was kept at 60 ° C. in a warm water bath, 31.4 g of a 6.2% aqueous solution of sodium persulfate was added dropwise to start the polymerization, and the polymerization reaction was continued for 8 hours to carry out the polymerization. After completion, a 30% aqueous sodium hydroxide solution was added so as to have a pH of 7, and the mixture was further diluted with ion-exchanged water to obtain a 40% aqueous solution of the vinyl copolymer. When this vinyl copolymer was analyzed, it was a vinyl copolymer (PC-3) having a mass average molecular weight of 18600.

Example 15 (Preparation of vinyl copolymer (PC-4))
170.4 g of the polyether ester monomer (MM-4) obtained in Test Category 2, 19.1 g of methacrylic acid, 1.9 g of sodium allylsulfonate, 1.7 g of thioglycerol and 172.4 g of ion-exchanged water were placed in the reaction vessel. Was charged and dissolved uniformly with stirring, and then the atmosphere was replaced with nitrogen. The temperature of the reaction system was kept at 70 ° C. in a warm water bath under a nitrogen atmosphere, and 31.4 g of 5% aqueous hydrogen peroxide solution was added dropwise to start the polymerization, and the polymerization reaction was continued for 5 hours to complete the polymerization and cool it. After that, a 30% aqueous sodium hydroxide solution was added so as to have a pH of 7, and the mixture was further diluted with ion-exchanged water to obtain a 40% aqueous solution of the vinyl copolymer. When this vinyl copolymer was analyzed, it was a vinyl copolymer (PC-4) having a mass average molecular weight of 26700.

-Examples 16 to 22 (preparation of vinyl copolymers (PC-5) to (PC-11))
Vinyl copolymers (PC-5) to (PC) of Examples 16 to 22 are the same as in Example 12 (preparation of vinyl copolymer (PC-1)) except that the changes are shown in Table 4. -11) was prepared.

Comparative Example 9 (Preparation of vinyl copolymer (RPC-1))
Example 12 (vinyl copolymer (PC-1)] except that the polyether ester monomer (MM-1) was replaced with the polyether ester monomer (RM-1) obtained in Test Category 2. Preparation), the vinyl copolymer (RPC-1) of Comparative Example 9 was prepared.

Comparative Examples 10 to 15 (Preparation of vinyl copolymers (RPC-2) to (RPC-7))
The vinyl copolymers (RPC-3) to (RPC-1) of Comparative Examples 11 to 15 are the same as in Comparative Example 9 (preparation of vinyl copolymer (RPC-1)) except that the changes are shown in Table 4. -7) was prepared. The contents of the obtained vinyl copolymers (PC-1) to (PC-11) and vinyl copolymers (RPC-1) to (RPC-7) are summarized in Table 4.

HEA, MA, SAS, and BA in Table 4 will be described below.
HEA: Hydroxyethyl acrylate MA: Methyl acrylate SAS: Sodium allyl sulfonate BA: Butyl acrylate

Test Category 4 (Preparation of Concrete Composition as Hydraulic Composition)

-Preparation of concrete composition The concrete composition of each test example was prepared as follows under the formulation conditions shown in Table 5. Ordinary Portoland cement (specific gravity = 3.16), fine aggregate (Oigawa water-based sand, specific gravity = 2.58) and coarse aggregate (crushed stone from Okazaki, specific gravity = 2.66) are sequentially added to a 50 L pan-type forced kneading mixer. It was put in and kneaded for 15 seconds. Next, the vinyl copolymer as an additive for the hydraulic composition prepared in Test Category 3 was kneaded and added together with water, and the mixture was kneaded for 120 seconds. At this time, an air entraining agent (Takemoto Oil & Fat Co., Ltd .: trade name AFK-2) was added to the cement at 0.0005%, and in Formulation 1, the target air volume was 4.0 to 5.0%. (Made by Takemoto Oil and Fat: Trade Name AE-300) was added to the cement in an amount of 0.0005 to 0.002%, and in Formulation 2, the mixture was kneaded without adding an air entraining agent.

-Evaluation of concrete composition The following evaluations were carried out for the concrete of each of the prepared test examples. The results are summarized in Table 6.
slump:
Immediately after kneading (that is, 0 minutes after kneading) and after allowing to stand for 30 minutes after kneading, measurements were made in accordance with JIS-A 1101, respectively.
Slump flow:
Immediately after kneading (that is, 0 minutes after kneading) and after allowing to stand for 30 minutes after kneading, measurements were made in accordance with JIS-A 1150, respectively.
Air volume:
Immediately after kneading (that is, 0 minutes after kneading) and after allowing to stand for 30 minutes after kneading, measurements were made in accordance with JIS-A 1128, respectively.
Compressive strength:
In accordance with JIS-A 1108, in a constant temperature room with a temperature of 20 ° C and humidity of 80%, a steel formwork with a diameter of 100 mm and a height of 200 mm is filled with a concrete composition, cured, and demolded in one day of age. did. Then, it was cured in water in a curing tank having a water temperature of 20 ° C. until the age of the material reached 28 days. After curing, the compressive strength of the 28-day-old specimen was measured.

In Test Examples 1 to 5, 7 to 11 and Comparative Test Examples 1 to 6, "slump" was evaluated, and in Test Example 6 and Comparative Test Example 7, "slump flow" was evaluated.

(result)
As shown in Table 3, Examples 1 to 11 in which the esterification reaction is carried out in the presence of the polymerization inhibitor A, the polymerization inhibitor B and the polymerization inhibitor C are the polymerization inhibitor A, the polymerization inhibitor B and the polymerization inhibitor. Compared with Comparative Examples 1 to 6 and Comparative Example 8 in which all of C was not used, the residue ratio was small, and gelation could be prevented. Further, as shown in Table 6, Test Examples 1 to 11 that go through Step 1 and Step 2 are Comparative Test Examples 1 to 11 in which all of the polymerization inhibitor A, the polymerization inhibitor B, and the polymerization inhibitor C are not used in the step 1. Compared with No. 7, the slump (or slump flow) and the amount of air were kept within a predetermined range, and excellent compressive strength could be obtained. In Comparative Example 7, the evaluation of the “sieve residue” was good, but the amount of the polymerization inhibitor was excessive, so that the polymerization reaction in the step 2 was insufficient. Therefore, when an additive for a hydraulic composition (dispersant for a hydraulic composition) is produced by using it as a monomer for an additive for a hydraulic composition (dispersant for a hydraulic composition), a desired polymer is produced. Was not obtained, and the slump became smaller (see Comparative Test Example 6). Here, when Comparative Example 14 and Example 12 are compared, they carry out the same polymerization, but in Comparative Example 14, the weight average molecular weight of the obtained polymer is smaller than that of Example 12. As described above, there is a problem that the function as an additive for a hydraulic composition (dispersant for a hydraulic composition) is deteriorated (a high-performance additive for a hydraulic composition cannot be obtained). Further, in Example 10, the addition ratio of the polymerization inhibitor C was less than 0.05% by mass with respect to the one-ended blocking polyalkylene glycol, and in Example 11, the addition ratio of the polymerization inhibitor A was one-ended blocking polyalkylene glycol. Since the addition ratio of the polymerization inhibitor B is less than 0.01% by mass with respect to the glycol and the addition ratio of the polymerization inhibitor B is 0.005% by mass with respect to the one-ended closed polyalkylene glycol, these Examples 10 and 11 are compared with other Examples. And, the effect of preventing gelation is not sufficiently exhibited and it is inferior.

The method for producing an additive for a hydraulic composition of the present invention can produce a high-performance additive for a hydraulic composition.

Claims (8)

A method for producing an additive for a hydraulic composition, which undergoes the following step 1 and the following step 2.
Step 1: An unsaturated carboxylic acid and a one-ended closed polyalkylene glycol represented by the following general formula (1) are subjected to an acid catalyst, a polymerization inhibitor A, a polymerization inhibitor B and a polymer-inhibiting agent B in the absence of a solvent. A step of obtaining a polyether ester monomer by an esterification reaction under heating and reduced pressure conditions in the presence of a polymerization inhibitor C.

(In the general formula (1), R ¹ represents an alkyl group having 1 to 22 carbon atoms or an aromatic group having 6 to 30 carbon atoms, AO represents an oxyalkylene group having 2 or 3 carbon atoms, and n represents 1 to 1. Represents an integer of 300.)
Polymerization inhibitor A: A phosphorus atom-free polymerization inhibitor having a vapor pressure of 25 ° C. of 0.01 Pa or more Polymerization inhibitor B: A phosphorus atom-free polymerization inhibitor having a vapor pressure of less than 0.01 Pa at 25 ° C. Agent C: Phosphorus atom-containing polymerization inhibitor Step 2: The polyether ester monomer obtained in the above step 1 and a vinyl monomer copolymerizable with the polyether ester monomer are mixed in an aqueous solvent. Step of radical copolymerization to obtain an additive for a water-hard composition The method for producing an additive for a water-hard composition according to claim 1, wherein the unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid and methacrylic acid. The method for producing an additive for a hydraulic composition according to claim 1 or 2, wherein the polymerization inhibitor A contains at least one selected from the group consisting of parabenzoquinone, naphthoquinone and quinhydrin. The method for producing an additive for a hydraulic composition according to any one of claims 1 to 3, wherein the polymerization inhibitor A contains parabenzoquinone. The method for producing an additive for a hydraulic composition according to any one of claims 1 to 4, wherein the polymerization inhibitor B contains phenothiazine. The method for producing an additive for a water-hard composition according to any one of claims 1 to 5, wherein the polymerization inhibitor C contains at least one selected from the group consisting of phosphorous acid and phosphorous acid ester. .. The addition ratio of the polymerization inhibitor A is 0.01 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol.
The addition ratio of the polymerization inhibitor B was 0.005 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol.
The additive for a water-hard composition according to any one of claims 1 to 6, wherein the addition ratio of the polymerization inhibitor C is 0.05 to 0.5% by mass with respect to the one-ended closed polyalkylene glycol. Manufacturing method. The one-sided blockage polyalkylene glycol according to any one of claims 1 to 7, wherein the AO in the general formula (1) is 95 mol% or more of the total oxyalkylene group is an oxyethylene group having 2 carbon atoms. The method for producing an additive for a water-hard composition according to the above.