JP2007186636A - Method for producing phosphate-based polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a phosphate-based polymer, by which the phosphate-based polymer useful as a dispersant imparting an excellent dispersing effect and an excellent viscosity-reducing effect to hydraulic compositions can be produced at an industrially practical level. <P>SOLUTION: This method for producing the phosphate-based polymer suitable as a dispersant for hydraulic compositions comprises copolymerizing a specific monomer 1 having a polyoxyalkylene group, a phosphoric monoester-based monomer 2 and a phosphoric diester-based monomer 3 in a reaction solvent containing an organic solvent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a phosphate ester polymer.

  Among the admixtures for hydraulic compositions, there is one called a high-performance water reducing agent having a large fluidity-imparting effect. Typical examples thereof include naphthalene sulfonic acid formaldehyde condensate salt (naphthalene type), melamine sulfonic acid formaldehyde condensate salt (melamine type), polycarboxylic acid type having a polyoxyalkylene chain, and the like.

  In recent years, concrete, which is a typical hydraulic composition, has become more durable. For example, the amount of water used in concrete has been reduced to increase its strength. Are also expected to increase. In order to reduce the amount of water, it is mainstream to use a polycarboxylic acid-based water reducing agent that is excellent in water reduction and fluidity retention. However, as the amount of water decreases, fresh concrete viscosity (hereinafter also referred to as concrete viscosity) increases, and there is a problem that workability and workability such as pumping, driving and filling into a mold form are lowered. This viscosity increase problem has not been sufficiently solved even with a polycarboxylic acid-based water reducing agent, and an additive having a higher concrete viscosity reducing effect is desired.

  Against this background, Patent Document 1 discloses a concrete admixture containing a vinyl copolymer containing a high-chain-length oxyalkylene group and a specific monomer as essential components. Further, Patent Document 2 discloses a monoester or monoether having a polyalkylene glycol chain in order to obtain a cement dispersant capable of exhibiting excellent flow characteristics, high dispersion effect and quick setting regardless of the mixing ratio of water. And a polymer of a monomer having an unsaturated bond and a phosphate group.

On the other hand, Patent Document 3 uses a polymer of an ethylenically unsaturated compound having a phosphate group or a copolymer of the polymer and a polymerizable monomer as a component of the composition for forming a conductive film. Is described.
JP 11-79811 A JP 2000-327386 A JP-A-48-34221

  Generally, a phosphate ester monomer is obtained as a mixture containing a monoester form and a diester form. Among these, since diesters are likely to have a high molecular weight (gelation) by crosslinking, such a mixture is restricted in production in fields using the properties, for example, thickeners, adhesives, coatings, etc. Can be used suitably without receiving much. On the other hand, in the case of an admixture for a hydraulic composition (dispersant, water reducing agent, etc.), a polymer containing a phosphate group is preferable because of its excellent adsorptive power to a hydraulic substance.

  However, the admixture for the hydraulic composition dissolves (disperses) the polymer uniformly in water and then adsorbs it uniformly on the hydraulic substance to exert its effect. It cannot be (dispersed), and is not preferable in that the dispersibility and the effect of reducing viscosity are poor.

  Patent Document 3 is for obtaining a cured film of a phosphoric acid polymer, and its use and form are extremely limited.

  An object of the present invention is to provide an excellent dispersion effect or viscosity reduction effect to a hydraulic composition containing a hydraulic powder, and further to provide both excellent effects, and the dispersion for a hydraulic composition having good performance. Another object of the present invention is to provide a method capable of producing a phosphoric ester polymer that can be used as an agent at an industrially practical level.

  The present invention includes a monomer 1 represented by the following general formula (1) [hereinafter referred to as monomer 1] and a monomer 2 represented by the following general formula (2) [hereinafter referred to as monomer 2]. And a monomer 3 represented by the following general formula (3) [hereinafter referred to as monomer 3] using a reaction solvent containing an organic solvent to produce a phosphate ester polymer Regarding the method.

[Wherein R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom or —COO (AO) _n X, AO is an oxyalkylene group or oxystyrene group having 2 to 4 carbon atoms, n is It is the average added mole number of AO, the number of 3-200, X represents a hydrogen atom or a C1-C18 alkyl group. ]

[Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 2 to 12 carbon atoms, m1 represents a number of 1 to 30, and M represents a hydrogen atom, an alkali metal or an alkaline earth metal. ]

[Wherein R ⁶ and R ⁸ are each a hydrogen atom or a methyl group, R ⁷ and R ⁹ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number from 1 to 30 and M is hydrogen. Represents an atom, an alkali metal or an alkaline earth metal. ]

  Moreover, this invention relates to the dispersing agent for hydraulic compositions containing the phosphate ester type polymer obtained with the manufacturing method of the said invention.

  According to the present invention, it is possible to industrially stably produce a water-soluble phosphate ester polymer without gelation. Further, since the amount of the chain transfer agent used can be reduced, the malodor of the polymer can be eliminated.

<< Production Method of Phosphate Ester Polymer >>
The present invention relates to a method for producing a phosphate ester polymer in which a monomer 1, a monomer 2, and a monomer 3 are copolymerized using a reaction solvent containing an organic solvent. Any of the phosphate ester polymers of the present invention can be produced by this production method. It is also preferable to use a mixed monomer containing monomer 2 and monomer 3.

  The present inventors have found that a polymer derived from a specific phosphate ester is useful for reducing the viscosity of a hydraulic composition which is one of the problems of the present invention. Furthermore, the manufacturing method suitable for industrialization of this polymer was discovered.

  Hereinafter, the manufacturing method of the phosphate ester type polymer using the monomers 1-3 is demonstrated.

  As described above, industrially, phosphate ester monomers are usually obtained as a mixture containing a monoester (monomer 2) and a diester (monomer 3). Among these, since diesters are likely to have a high molecular weight (gelation) by crosslinking, such a mixture is restricted in production in fields using the properties, for example, thickeners, adhesives, coatings, etc. Can be used suitably without receiving much. On the other hand, for admixtures for hydraulic compositions (dispersants, water reducing agents, etc.), copolymers containing phosphate groups are preferred because of their excellent adsorptive power to hydraulic substances, but dispersibility and viscosity are reduced by increasing the molecular weight. This is not preferable from the viewpoint of handleability. However, it is industrially disadvantageous to separate the monoester form and the diester form from the mixture of phosphate esters as raw materials from the application and economical properties of the hydraulic composition. In the production method of the present invention, the monomer 1, the monomer 2 and the monomer 3 which are phosphate ester monomers are copolymerized using a reaction solvent containing an organic solvent. Since this manufacturing method can maintain the excellent performance of the phosphate ester polymer as a dispersant for a hydraulic composition, this manufacturing method is extremely advantageous in the field of hydraulic compositions.

  The phosphoric acid ester polymer according to the present invention is represented by the monomer 1 having an oxyalkylene group represented by the general formula (1) and the general formulas (2) and (3) having a phosphoric acid group. It is a polymer obtained by copolymerizing the monomers 2 and 3 to be produced.

  Preferable monomers 1 to 3 used in the present invention are as follows, and commercially available products and reaction products can also be used.

[Monomer 1]
For monomer 1, R ³ in general formula (1) is preferably a hydrogen atom, and AO is preferably an oxyalkylene group having 2 to 4 carbon atoms, and more preferably contains an ethyleneoxy group (hereinafter referred to as EO group). The EO group is 70 mol% or more, more preferably 80 mol% or more, more preferably 90 mol% or more, and particularly preferably all AO is an EO group in the total AO. X is preferably a hydrogen atom or an alkyl group having 1 to 18, more preferably 1 to 12, further 1 to 4, and 1 or 2 carbon atoms, and particularly preferably a methyl group. Specific examples include ω-methoxypolyoxyalkylene methacrylate and ω-methoxypolyoxyalkylene acrylate, and ω-methoxypolyoxyalkylene methacrylate is more preferable. Here, n in the formula (1) is the average added mole number. In terms of dispersibility of the polymer in the hydraulic composition and the effect of imparting viscosity, n is 3 to 200, preferably 4 to 120. In addition, AO is different among n repeating units on average, and random addition, block addition, or a mixture thereof may be included. AO can also contain a propyleneoxy group etc. besides EO group.

[Monomer 2]
Examples of the monomer 2 include phosphoric acid monoesters of organic hydroxy compounds. Specific examples include polyalkylene glycol mono (meth) acrylate acid phosphates. For example, phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid mono-[(2-hydroxyethyl) acrylic acid ester] and the like can be mentioned. Among these, phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester is preferable from the viewpoint of ease of production and product quality stability.

[Monomer 3]
Examples of the monomer 3 include phosphoric acid diesters of organic hydroxy compounds. Specific examples include polyalkylene glycol di (meth) acrylate acid phosphoric acid diester. Examples include phosphoric acid di-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid di-[(2-hydroxyethyl) acrylic acid] ester, and the like. Among these, di-[(2-hydroxyethyl) methacrylic acid] ester phosphate is preferable from the viewpoint of ease of production and quality stability of the product.

  Any of the monomers 2 and 3 may be a salt, and may be an alkali metal salt, alkaline earth metal salt, ammonium salt, alkylammonium salt or the like of these compounds.

  M1 of the monomer 2 and m2 and m3 of the monomer 3 are each preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 5.

  Moreover, in the manufacturing method of this invention, the mixed monomer containing the monomer 2 and the monomer 3 can be used.

  As the mixed monomer containing the monomer 2 and the monomer 3, a commercial product containing a monoester and a diester can be used. For example, Phosmer M, Phosmer PE, Phosmer P ( Unichemical), JAMP514, JAMP514P, JMP100 (all Johoku Chemical), light ester P-1M, light acrylate P-1A (all Kyoeisha Chemical), MR200 (Daihachi Chemical), Kayamar (Nippon Kayaku), Ethyleneglycol methacrylate Available as phosphate (Aldrich reagent).

Moreover, the mixed monomer containing the monomer 2 and the monomer 3 is, for example, an organic hydroxy compound represented by the general formula (4), phosphoric anhydride (P ₂ O ₅ ), and water in a predetermined charging ratio. Can be produced as a reaction product.

  Monomers 2 and 3 are phosphoric acid esters of monomers having unsaturated bonds and hydroxyl groups, and the above-mentioned commercially available products and reaction products include monoester (monomer 2) and diester ( It has been confirmed that it contains compounds other than monomer 3). These other compounds are considered to be a mixture of polymerizable and non-polymerizable compounds, but in the present invention, such a mixture (mixed monomer) can be used as it is.

The contents of monomers 2 and 3 in the mixed monomer can be calculated based on ³¹ P-NMR measurement results.
< ³¹ P-NMR measurement conditions>
・ Inverse-gated-decoupling method
・ Measurement range: 6459.9Hz
・ Pulse delay time 30sec
Observation data point 10336
・ Pulse width (5.833μsec) 35 ° pulse ・ Solvent CD ₃ OH (deuterated methanol) (30% by weight)
・ Number of integration 128

  Under these conditions, the signal of the obtained chart belongs to the following compound, so that it is possible to determine the relative quantitative ratio from the area ratio.

For example, when the organic hydroxy compound is a phosphorous oxide of “2-hydroxyethyl methacrylate”, it can be assigned as follows.
・ 1.8ppm to 2.6ppm: phosphoric acid ・ 0.5ppm to 1.1ppm: Monomer 2 (monoester)
-0.5 ppm to 0.1 ppm: monomer 3 (diester form)
-1.0 ppm to -0.6 ppm: Triester form -11.1 ppm to -10.9 ppm, -12.4 ppm to -12.1 ppm: Pyrophosphate monoester --12.0 ppm to -11.8 ppm: Pyrophosphate diester -11.2 ppm to -11.1ppm: pyrophosphoric acid, other peaks: unknown

  In the present invention, the phosphoric acid content in the mixed monomer is quantified to determine the ratio of the monomer 2 and the monomer 3 in the mixed monomer. Specifically, the calculation is performed as follows.

The absolute amount (% by weight) of the phosphoric acid content in the sample is determined by gas chromatography. ^Since the relative molar ratio of phosphoric acid, mono-isomer, and di-isomer in the sample can be obtained from the ³¹ P-NMR result, the absolute amount of mono-isomer and di-isomer is calculated based on the absolute amount of phosphoric acid.

[Phosphoric acid content]
The conditions for gas chromatography are as follows.
Sample: Methylation with diazomethane Example) Methylation by adding 1 to 1.5 cc of diazomethane in diethyl ether to 0.1 g of sample Column: Ultra ALLOY, 15 m × 0.25 mm (inner diameter) × 0.15 μmdf
Carrier gas: He, split ratio 50: 1
Column temperature: 40 ° C. (5 min) (hold) → 10 ° C./min (temperature rise) → 15 min after reaching 300 ° C. Hold inlet temperature: 300 ° C.
Detector temperature: 300 ° C
Under the above conditions, a phosphate-derived peak is detected around 9 minutes, and the phosphate content in the unknown sample can be calculated by a calibration curve method.

[Content of mono- and di-form]
Based on the phosphoric acid content determined above, the total amount of mono- and di-isomers in the reagents used in Examples and the like described below was calculated as follows. The pyrophosphoric acid monoester, pyrophosphoric acid diester, and pyrophosphoric acid were calculated by assigning the decomposition products to phosphoric acid and the monoester compound in consideration of hydrolysis during the polymerization process.
・ Hosmer M (Unichemical Co., Ltd.): 81.8% by weight

When the charge molar ratio of the monomer is calculated based on the breakdown of the mono- and di-forms from the above results and the NMR results, the case of Production Example 1 is as follows.
Ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide 23: NK ester M230G manufactured by Shin-Nakamura Chemical) = 51 mol%
Phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester = 34 mol%
・ Di-[(2-hydroxyethyl) methacrylic acid] ester = 15 mol%

  From the viewpoint of fluidity and viscosity reduction, it is better to use a mixture of phosphate esters containing a large amount of monoester, but even if it contains a large amount of diester, By controlling the polymerization molar ratio, fluidity and viscosity reduction can be adjusted.

  In the copolymerization of the monomers, the molar ratio between the monomer 1 and the monomers 2 and 3 is as follows: monomer 1 / (monomer 2 + monomer 3) = 5/95 to 95/5 Furthermore, 10/90 to 90/10 are preferable. The molar ratio of monomer 1, monomer 2 and monomer 3 is as follows: monomer 1 / monomer 2 / monomer 3 = 5 to 95/3 to 90/1 to 80 / 5 to 96/3 to 80/1 to 60 (however, the total is 100) is preferable. In addition, about the monomer 2 and the monomer 3, the molar ratio and mol% shall be calculated based on an acid type compound (hereinafter the same).

Moreover, in this invention, the ratio of the monomer 3 can be 1-60 mol% in all the monomers used for reaction, and also can be 1-30 mol%.
Further, the molar ratio of the monomer 2 and the monomer 3 can be set to monomer 2 / monomer 3 = 99/1 to 4/96, and more preferably 99/1 to 5/95.
Since the monomer raw material containing the monomer 3 in such a range is generally expected to be gelled, it is usually not suitable as a raw material for producing a polymer for a dispersant for a hydraulic composition. it is conceivable that. However, in the present invention, by reacting the monomer in a polymerization solvent containing an organic solvent, gelation is suppressed and a phosphate ester polymer suitable as a dispersant for a hydraulic composition is stable with good reproducibility. Therefore, it can be manufactured at a level that is industrially practical.

  In the production method of the present invention, the reaction rate of the monomers 2 and 3 is preferably 60% or more, more preferably 70% or more. Here, the reaction rate of the monomers 2 and 3 is calculated by the following equation.

In addition, the ratio (mol%) of the monomer 2 and the monomer 3 in the phosphorus-containing compound in the reaction system at the start of the reaction and at the end of the reaction can be calculated based on the measurement result of ¹ H-NMR. .

In addition, since the double bond derived from a monomer has disappeared by ¹ H-NMR under the following conditions, the phosphate ester polymer of the present invention is derived from each of monomers 1, 2, and 3. It is suggested to have a structural unit.
[ ¹ H-NMR conditions]
A polymer dissolved in water and dried under reduced pressure is dissolved in deuterated methanol at a concentration of 3 to 4% by weight, and ¹ H-NMR is measured. The residual rate of double bonds is measured by an integrated value of 5.5 to 6.2 ppm. In addition, the measurement of ¹ H-NMR uses “Mercury 400 NMR” manufactured by Varian, the number of data points is 42052, the measurement range is 6410.3 Hz, the pulse width is 4.5 μs, the pulse waiting time is 10 S, and the measurement temperature is 25.0 ° C. Perform under conditions.

  That is, the phosphate ester-based polymer of the present invention having Mw as described above has, as its constituent units, constituent units derived from monomer 1, constituent units derived from monomer 2, and constituents derived from monomer 3. Includes units. These structural units are structural units derived from the respective monomers incorporated into the polymer by cleavage of the ethylenically unsaturated bonds of the monomers 1, 2 and 3 and addition polymerization. The ratio of these structural units in the polymer depends on the charging ratio, and when the monomers used for copolymerization are only monomers 1 to 3, the molar ratio of each structural unit is the monomer charging molar ratio. It is thought that it is almost the same.

  In the production of the phosphate ester polymer according to the present invention, in addition to the monomers 1 to 3, other monomers capable of copolymerization may be used. Examples of the other copolymerizable monomer include sulfonic acid or carboxylic acid having an unsaturated group, and salts thereof. For example, allyl sulfonic acid, methallyl sulfonic acid, alkali metal salt, alkaline earth metal salt, ammonium salt, or amine salt of any of these can be mentioned. In addition, acrylic monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and the like, and any one or more of alkali metal salts, alkalis Anhydrous compounds such as earth metal salts, ammonium salts, amine salts, methyl esters, ethyl esters and maleic anhydride may also be used. Furthermore, (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2- (meth) acrylamide-2-metasulfonic acid, 2- (meth) acrylamide-2-ethanesulfonic acid, Examples include 2- (meth) acrylamide-2-propanesulfonic acid, styrene, styrenesulfonic acid and the like. The total proportion of monomers 1 to 3 in all monomers is preferably 30 to 100 mol%, more preferably 50 to 100 mol%, and particularly preferably 75 to 100 mol%. From the viewpoint of achieving the performance as a dispersant described in the coalescence, it is more than 95 mol% to 100 mol%, and more preferably 97 to 100 mol%.

  The total amount of the monomers 1, 2, 3 in the reaction system and other monomers copolymerizable is preferably 5 to 80% by weight, more preferably 10 to 65% by weight in the reaction system, and 20 to 50% by weight. Is particularly preferred.

  In the production method of the present invention, the reaction temperature of the monomers 1 to 3 is preferably 40 to 100 ° C., more preferably 60 to 90 ° C., and the reaction pressure is 101.3 to 111.5 kPa (1 to 1.1 atm) as a gauge pressure. ) And 101.3-106.4 kPa (1-1.05 atm).

  In the production method of the present invention, the monomer solution containing the monomer 2 and / or the monomer 3 prepared with an appropriate solvent is preferably added to the monomer 1 in the presence of a predetermined amount of chain transfer agent. Is copolymerized with another monomer containing benzene in a reaction solvent containing an organic solvent. Moreover, you may use the other monomer, polymerization initiator, etc. which can be copolymerized.

Specifically, the polymerization reaction in the production method of the present invention is as follows.
(I) The copolymerization reaction is started using a monomer solution containing the monomers 1 to 3.
(Ii) A monomer solution containing the monomers 1 to 3 is dropped into the reaction system.
(Iii) A monomer solution containing monomer 1, a monomer solution containing monomer 2, and a monomer solution containing monomer 3 are separately prepared in a reaction system (reaction solvent containing an organic solvent). ).
(Iv) The reaction is carried out in a reaction solvent containing an organic solvent by appropriately combining the above. For example, a part of the monomer solution containing the monomers 1 to 3 is charged into the reaction system, and the remaining monomer solution is dropped into the reaction system.

  In the above (iii) and (iv), it is necessary to control the dropping conditions of the monomer solution to be dropped so as not to deviate from the set monomer molar ratio.

[Chain transfer agent]
It is preferable to use a chain transfer agent from the viewpoint of suppressing gelation, adjusting the suitable molecular weight, and designing the performance of the dispersant for hydraulic composition. The chain transfer agent has a function of causing a chain transfer reaction in radical polymerization (a reaction in which a growing polymer radical reacts with another molecule to move a radical active site). It is a substance to be added. In the present invention, it is basically not necessary to use a chain transfer agent, but it is used in a small amount, for example, in the range of 0 to 3 mol% with respect to the total number of moles of monomers 1 to 3 for adjusting the molecular weight. May be.

  Examples of chain transfer agents include thiol chain transfer agents and halogenated hydrocarbon chain transfer agents, and thiol chain transfer agents are preferred.

As the thiol chain transfer agent, those having a —SH group are preferable, and in particular, the general formula HS—R—Eg (wherein R represents a hydrocarbon-derived group having 1 to 4 carbon atoms, and E is − OH, —COOM, —COOR ′ or —SO ₃ M group, M represents a hydrogen atom, monovalent metal, divalent metal, ammonium group or organic amine group, and R ′ represents an alkyl having 1 to 10 carbon atoms. In which g represents an integer of 1 to 2, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, Examples include octyl thioglycolate, octyl 3-mercaptopropionate, and the like from the viewpoint of chain transfer effect in a copolymerization reaction including monomers 1 to 3. Mercaptoethanol are preferable, more preferably mercaptopropionic acid. These 1 type (s) or 2 or more types can be used.

  Examples of the halogenated hydrocarbon chain transfer agent include carbon tetrachloride and carbon tetrabromide.

  Examples of other chain transfer agents include α-methylstyrene dimer, terpinolene, α-terpinene, γ-terpinene, dipentene, 2-aminopropan-1-ol and the like. A chain transfer agent can use 1 type (s) or 2 or more types.

[Polymerization initiator]
In the production method of the present invention, it is preferable to use a polymerization initiator, and in particular, 0.1 mol% or more, and further 0.1 to 15 mol of the polymerization initiator with respect to the total number of moles of monomers 1 to 3. %, Particularly 1 to 10 mol% is preferably used.

  As the polymerization initiator, a peroxide, an azo compound, or the like can be used. Examples include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2-methylpropionamide) dihydrate, etc. A compound is used. In addition, an accelerator such as sodium bisulfite and an amine compound can be used in combination with the polymerization initiator.

[solvent]
The production method of the present invention is carried out by a solution polymerization method using a reaction solvent containing an organic solvent. Examples of the organic solvent used at that time include alcohols and ketones. Examples of the alcohol include methanol, ethanol, isopropanol and the like, and examples of the ketone include acetone and methyl ethyl ketone. Alcohol is preferable, and isopropanol is particularly preferable. Examples of the solvent other than the organic solvent include water. The content of the organic solvent is preferably 90% by weight or more, more preferably 95% by weight or more in the total solvent.

  In the production method of the present invention, from the viewpoint of industrial productivity and waste liquid treatment, the polymerization concentration is preferably 10% by weight or more, more preferably 20% by weight or more, and further preferably 25% by weight or more. Here, the polymerization concentration refers to the total weight of all components (for example, monomers 1 to 3, polymerization initiator, chain transfer agent, etc.) other than the reaction solvent used in the reaction, and the total weight of these components and the reaction solvent. The divided value is multiplied by 100. That is, polymerization concentration (% by weight) = [(total weight of all components other than reaction solvent used in reaction) / (total weight of all components other than reaction solvent used in reaction + weight of reaction solvent)] × 100 is there.

  From the viewpoint of controlling the molecular weight of the polymer obtained and the viscosity of the polymer solution, the polymerization concentration is preferably 70% by weight or less, more preferably 60% by weight or less, and further preferably 50% by weight or less.

  Therefore, from the viewpoints of industrial productivity and waste liquid treatment, molecular weight control of the resulting polymer and viscosity of the polymer solution, the polymerization concentration is preferably 10 to 70% by weight, more preferably 20 to 60% by weight, 25 to 50% by weight is preferred.

<< Phosphate ester polymer >>
The phosphate ester polymer of the present invention is a phosphate ester polymer obtained by copolymerizing monomer 1, monomer 2 and monomer 3 using a reaction solvent containing an organic solvent. It is a coalescence. Preferred structures of the monomers 1 to 3 are as described above.

  The phosphate ester polymer of the present invention preferably has a weight average molecular weight (hereinafter referred to as Mw) of 10,000 to 150,000. Mw is preferably 10,000 or more, more preferably 12,000 or more, still more preferably 13,000 or more, still more preferably 14,000 or more, and particularly preferably 15, from the viewpoint of the expression of the dispersion effect and the viscosity reduction effect. 15,000 or less, preferably 150,000 or less, more preferably 130,000 or less, and further preferably 120,000 or less from the viewpoint of dispersion effect and viscosity reduction effect in terms of high molecular weight by crosslinking, suppression of gelation and performance. More preferably, it is 110,000 or less, particularly preferably 100,000 or less, and from the viewpoints of both, preferably 12,000 to 130,000, more preferably 13,000 to 120,000, still more preferably 14 1,000 to 110,000, particularly preferably 15,000 to 100,000.

Mw of the phosphate ester polymer of the present invention is measured by a gel permeation chromatography (GPC) method under the following conditions.
[GPC conditions]
Column: G4000PWXL + G2500PWXL (Tosoh)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 1.0mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2mg / mL
Reference material: Polyethylene glycol equivalent

  Further, in the chart pattern showing the molecular weight distribution obtained by the GPC method under the above conditions, the area having a molecular weight of 100,000 or more is 5% or less of the total area of the chart, so that dispersibility (required addition amount reduction) It is more preferable in terms of the viscosity reducing effect.

<< Dispersant for hydraulic composition >>
The phosphate ester polymer of the present invention can be used as a dispersant for a hydraulic composition in various inorganic hydraulic powders that exhibit curability by a hydration reaction, including various cements. The dispersant for a hydraulic composition containing the polymer of the present invention may be powdery or liquid. In the case of a liquid form, those using water as a solvent or a dispersion medium (such as an aqueous solution) are preferable from the viewpoint of workability and reduction of environmental load. In the dispersant of the present invention, the content of the polymer of the present invention is preferably 10 to 100% by weight, more preferably 15 to 100% by weight, and still more preferably 20 to 100% by weight in the solid content. In the case of a liquid, the solid content concentration is preferably 5 to 40% by weight, more preferably 10 to 40% by weight, and still more preferably 20 to 35% by weight, from the viewpoints of manufacturability and workability. Further, the dispersant of the present invention may be used in a ratio of 0.02 to 1 part by weight and 0.04 to 0.4 part by weight in solid content concentration of the polymer with respect to 100 parts by weight of the hydraulic powder. From the viewpoint of dispersion effect.

  Examples of the cement include ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, and eco-cement (for example, JIS R5214). As hydraulic powder other than cement, blast furnace slag, fly ash, silica fume and the like may be included, and non-hydraulic limestone fine powder and the like may be included. Silica fume cement or blast furnace cement mixed with cement may be used.

  The dispersant for hydraulic composition of the present invention can also contain other additives (materials). For example, resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, alkylbenzene sulfonic acid (salt), alkane sulfonate, polyoxyalkylene alkyl (phenyl) ether, polyoxyalkylene alkyl (phenyl) ether sulfate (salt) ), Polyoxyalkylene alkyl (phenyl) ether phosphates (salts), protein materials, AE agents such as alkenyl succinic acid and α-olefin sulfonate; oxy such as gluconic acid, glucoheptonic acid, alabonic acid, malic acid, citric acid Delayers such as carboxylic acids, dextrins, monosaccharides, oligosaccharides, polysaccharides, etc .; foaming agents; thickeners; silica sand; AE water reducing agents; calcium chloride, calcium nitrite, calcium nitrate , Cal bromide Soluble calcium salts such as um, calcium iodide, chlorides such as iron chloride and magnesium chloride, sulfates, potassium hydroxide, sodium hydroxide, carbonates, thiosulfates, formic acid (salts), alkanolamines, etc. Strongening agent or accelerator; foaming agent; waterproofing agent such as resin acid (salt), fatty acid ester, oil, fat, silicone, paraffin, asphalt, wax; blast furnace slag; fluidizing agent; dimethylpolysiloxane, polyalkylene glycol fatty acid ester Anti-foaming agents such as mineral oils, oils and fats, oxyalkylenes, alcohols, amides, etc .; antifoaming agents; fly ash; melamine sulfonic acid formalin condensates, aminosulfonic acids, polymaleic acids and other polycarboxylic acids High-performance water-reducing agent such as silica; Silica fume; Rust inhibitor such as nitrite, phosphate, zinc oxide; Methyl cellulose , Celluloses such as hydroxyethyl cellulose, natural products such as β-1,3-glucan and xanthan gum, polyacrylic acid amide, polyethylene glycol, ethylene oxide adduct of oleyl alcohol or a reaction product thereof with vinylcyclohexene diepoxide, etc. Water-soluble polymers such as synthetic systems; polymer emulsions such as alkyl (meth) acrylates.

  Moreover, the dispersing agent for hydraulic compositions of the present invention is not only for ready-mixed concrete and concrete vibration products, but also for self-leveling, for refractories, for plaster, for gypsum slurry, for lightweight or heavy concrete, for AE, for repair. It is useful in any field of various concrete such as prepacked, trayy, ground improvement, grout, and cold.

<< Hydraulic composition >>
In addition, the hydraulic composition that is the target of the dispersant of the present invention has a water / hydraulic powder ratio [weight percentage (% by weight) of water and hydraulic powder in the hydraulic composition, hereinafter referred to as W / P. Is written. ] Is 65% or less, more preferably 10 to 60%, still more 12 to 57%, and particularly 15 to 55% and further 20 to 55% in that the low-viscosity effect is exhibited.

  Moreover, although the hydraulic composition of this invention is a paste, mortar, concrete, etc. containing water and hydraulic powder (cement), you may contain an aggregate. Examples of the aggregate include fine aggregate and coarse aggregate. The fine aggregate is preferably mountain sand, land sand, river sand and crushed sand, and the coarse aggregate is preferably mountain gravel, land gravel, river gravel and crushed stone. Depending on the application, lightweight aggregates may be used. The term “aggregate” is based on “Concrete Overview” (published on June 10, 1998, published by Technical Shoin).

Production Example 1
Hosmer M (Made by Unichemical Co., Monomer 2, Mixture containing Monomer 3, Total amount of Monomers 2 and 3 81.8% by weight) 29g, NK ester M230G (Shin Nakamura Chemical Co., ω-methoxypolyethylene glycol) Monomethacrylate: mole number of ethylene oxide added 23) 113 g and isopropanol 60 g were mixed to prepare a monomer mixture. This monomer mixed solution and an initiator solution (a mixture of 2.31 g of 2,2′-azobis (2,4-dimethylvaleronitrile) and 40 g of isopropanol) were dropped into a flask charged with 258 g of isopropanol over 60 minutes. The reaction conditions were performed in a nitrogen atmosphere at 80 ° C. After completion of the dropwise addition, the reaction was carried out at 80 ° C. for 120 minutes, followed by cooling, further adding 258 g of water and neutralizing with 17.7 g of a 30% aqueous sodium hydroxide solution to obtain a polymer solution. The polymerization concentration was 28.7% by weight, the reaction rate of monomers 2 and 3 after completion of polymerization was 71%, and the weight average molecular weight of the polymer was 43200.

Production Example 2
A polymer solution was produced in the same manner as in Production Example 1 except that 29 g of phosmer M, 113 g of NK ester M230G, 0.59 g of 3-mercaptopropionic acid and 60 g of isopropanol were used as the monomer mixture. The polymerization concentration was 28.7% by weight, the reaction rate of monomers 2 and 3 after polymerization was 70%, and the weight average molecular weight of the polymer was 31,800.

Evaluation of Hydraulic Composition Dispersion Performance Manufacturing of the amount of addition of Table 1 in solid content (components other than solvent) to 300 parts by weight of ordinary Portland cement (equal mixture of Taiheiyo Cement and Sumitomo Osaka Cement) Add a total amount of water of 75 parts by weight of the polymer solution of Example 1 or 2 and the water in the polymer solution, and mix at low speed with a hand mixer for 3 minutes to make a flow cone (φ50mm x height 51mm). The paste flow was measured after filling. The results are shown in Table 1.

Claims (4)

Monomer 1 represented by the following general formula (1), monomer 2 represented by the following general formula (2), and monomer 3 represented by the following general formula (3) are organic A method for producing a phosphate ester polymer, which is copolymerized using a reaction solvent containing a solvent.

[Wherein R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom or —COO (AO) _n X, AO is an oxyalkylene group or oxystyrene group having 2 to 4 carbon atoms, n is It is the average added mole number of AO, the number of 3-200, X represents a hydrogen atom or a C1-C18 alkyl group. ]

[Wherein, R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 2 to 12 carbon atoms, m1 represents a number of 1 to 30, and M represents a hydrogen atom, an alkali metal or an alkaline earth metal. ]

[Wherein R ⁶ and R ⁸ are each a hydrogen atom or a methyl group, R ⁷ and R ⁹ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number from 1 to 30 and M is hydrogen. Represents an atom, an alkali metal or an alkaline earth metal. ]   The method for producing a phosphate ester polymer according to claim 1, wherein the polymerization concentration is 10% by weight or more.   The method for producing a phosphate ester polymer according to claim 1 or 2, wherein the obtained phosphate ester polymer has a weight average molecular weight of 10,000 to 150,000.   The dispersing agent for hydraulic compositions containing the phosphate ester type polymer obtained with the manufacturing method of any one of Claims 1-3.