JP2005029469A - Cement dispersing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cement dispersing agent comprising a graft copolymer and exhibiting excellent performance by manufacturing a high quality polyetherester monomer without using a solvent and using the high quality polyetherester monomer as an intermediate raw material. <P>SOLUTION: An allyl ether ester monomer is manufactured by esterifying α-allyl-ω-hydroxy-polyoxyalkylene purified to have ≤5.0 meq/kg peroxide value with an aliphatic monocarboxylic acid in the presence of no solvent and an anti-oxidant under a specific condition and is used for the intermediate raw material in the manufacture of the graft copolymer and/or the salt used as the cement dispersing agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cement dispersant. α-Allyl-ω-hydroxy-polyoxyalkylene and an aliphatic monocarboxylic acid are esterified to produce an allyl ether ester monomer as an intermediate raw material, and then this allyl ether ester monomer And a vinyl copolymer copolymerizable therewith to form a vinyl copolymer, and further, for example, a graft copolymer obtained by grafting a polyoxyalkylene monoalkyl ether to the vinyl copolymer, The salt is expected to be used as a cement dispersant. In this case, the quality of the raw material monomer used for radical copolymerization reaction and graft reaction, especially the allyl ether ester monomer, is large in performance when the obtained graft copolymer or its salt is used as a cement dispersant. affect. If the quality of the allyl ether ester monomer as an intermediate raw material is poor, the desired performance is not exhibited even if the obtained graft copolymer or salt thereof is used as a cement dispersant.

  The present invention produces a high-quality allyl ether ester monomer without using a solvent, and uses such a high-quality allyl ether ester monomer as an intermediate raw material. When salt is used as a cement dispersant, the hydraulic cement composition can be given excellent fluidity with little slump loss, and the durability and compression of the cured product obtained by curing the hydraulic cement composition against freeze-thaw action. The present invention relates to a cement dispersant that can sufficiently ensure strength.

  Conventionally, allyl ether ester monomers as described above are esterified with α-allyl-ω-hydroxy-polyoxyalkylene and aliphatic monocarboxylic acid using an organic solvent such as benzene, toluene, cyclohexane or hexane. It is manufactured by reacting. However, when an organic solvent is used in this way, it is necessary to recover the used organic solvent. Due to the recovery of the organic solvent used, the production cost of allyl ether ester including the installation of the recovery equipment, and thus the production cost of the graft copolymer as a cement dispersant using this as an intermediate raw material becomes high. Workers are forced to perform recovery operations in an unfavorable environment.

  In particular, α-allyl-ω-hydroxy-polyoxyalkylene, which is a raw material for producing allyl ether ester monomers, is obtained by subjecting allyl alcohol to ring-opening addition reaction of alkylene oxide, and thus usually ring-opening addition. When the reacted α-allyl-ω-hydroxy-polyoxyalkylene is mass-produced industrially and is used, that is, when an allyl ether ester monomer is produced by esterification with an aliphatic monocarboxylic acid However, when an allyl ether ester monomer is produced using such α-allyl-ω-hydroxy-polyoxyalkylene, a high-quality allyl ether ester monomer is actually produced. Can not be produced, using such allyl ether ester monomer as an intermediate raw material Be prepared the graft copolymer, it is not possible to exhibit excellent performance as a cement dispersant in such graft copolymers.

  The problem to be solved by the present invention can be obtained by producing a high-quality allyl ether ester monomer without using a solvent, and using such a high-quality allyl ether ester monomer as an intermediate raw material. This is because the graft copolymer or a salt thereof exhibits excellent performance as a cement dispersant.

  As a result of studies conducted by the present inventors to solve the above-mentioned problems, 1) In order to produce a high-quality allyl ether ester monomer, a high-quality α-allyl-ω-hydroxy-poly is used as a raw material. It is essential to use oxyalkylene. 2) The raw material α-allyl-ω-hydroxy-polyoxyalkylene is obtained by subjecting the corresponding allyl alcohol to ring-opening addition reaction of alkylene oxide, and is usually thus The α-allyl-ω-hydroxy-polyoxyalkylene subjected to the ring-opening addition reaction is industrially mass-produced, and the allyl ether ester monomer is obtained by esterification with an aliphatic monocarboxylic acid until use. Those that have been preserved until the time of manufacture are used, but in such α-allyl-ω-hydroxy-polyoxyalkylene, there is a ring opening. Depending on the conditions at the time of the addition reaction and the purification conditions after the ring-opening addition reaction, peroxides may remain as by-products, and in particular, the same peroxide may remain as a by-product depending on the conditions during storage. When the peroxide value by an oxide exceeded a certain value, the above knowledge was obtained that a high quality allyl ether ester monomer could not be produced from such α-allyl-ω-hydroxy-polyoxyalkylene.

  Therefore, as a result of further investigation, the present inventors have used 3) α-allyl-ω-hydroxy-polyoxyalkylene that has been purified so that the peroxide value is not more than a certain value. -When a hydroxy-polyoxyalkylene and an aliphatic monocarboxylic acid are subjected to an esterification reaction in the absence of a solvent in the presence of an antioxidant, a high quality allyl ether ester 4) Such a high-quality allyl ether ester monomer and maleic anhydride are subjected to radical copolymerization reaction to give a vinyl copolymer, and this vinyl copolymer is further polyoxyalkylene monoalkyl ether. And / or graft copolymers obtained by graft reaction of polyoxyalkylene monoalkyl esters and their salts are excellent as cement dispersants. To exert the function, it was found above.

That is, the present invention relates to a cement dispersant characterized by comprising a graft copolymer and / or a salt thereof obtained through the following first step and second step.
First step: α-allyl-ω-hydroxy-polyoxyalkylene represented by the following chemical formula 1 purified to have a peroxide value of 5.0 meq / kg or less, and an aliphatic monoform represented by the following chemical formula 2 Carboxylic acid was subjected to an esterification reaction in the absence of a solvent in the presence of an antioxidant under heating and reduced pressure conditions using an acid catalyst while distilling off the produced water. Obtaining an allyl ether ester monomer.
Second step: After the allyl ether ester monomer obtained in the first step and maleic anhydride are subjected to radical copolymerization reaction to obtain a vinyl copolymer, the vinyl copolymer is subjected to polyoxyalkylene monoalkyl ether and A step of graft-reacting a polyoxyalkylene monoalkyl ester to obtain a graft copolymer.

In Chemical Formulas 1 to 3,
R: Aliphatic alkyl group having 1 to 6 carbon atoms A: All hydroxyl groups from polyalkylene glycol having 2 to 250 repeating oxyalkylene units consisting of only oxyethylene units or oxyethylene units and oxypropylene units Excluded residues

  First, the first step will be described. In the first step, the α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 has a peroxide value of 5.0 meq / kg or less, preferably 3.0 meq / kg or less, more preferably 2.0 meq / kg. Use a product that has been purified to a weight of kg or less. As described above, α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 can be obtained by subjecting the corresponding allyl alcohol to ring-opening addition reaction of alkylene oxide, and can be obtained as such a ring-opening addition reaction product. In α-allyl-ω-hydroxy-polyoxyalkylene, peroxide remains as a by-product due to the conditions during the ring-opening addition reaction and the purification conditions after the ring-opening addition reaction. Depending on the conditions, a similar peroxide is formed as a by-product and remains. And when the peroxide value exceeds 5.0 meq / kg, even if such α-allyl-ω-hydroxy-polyoxyalkylene is esterified with an aliphatic monocarboxylic acid represented by Chemical Formula 2, high quality is obtained. The allyl ether ester monomer cannot be obtained. Accordingly, in the first step, α-allyl- represented by Chemical Formula 1 is purified so that the peroxide value is 5.0 meq / kg or less, preferably 3.0 meq / kg or less, more preferably 2.0 meq / kg or less. The ω-hydroxy-polyoxyalkylene is subjected to an esterification reaction with an aliphatic monocarboxylic acid represented by Chemical Formula 2. Here, the peroxide value (meq / kg) is a value measured according to the method described in the standard oil analysis test method (I) (1996 version) established by the Japan Oil Chemists' Society.

  Examples of the purification treatment method for reducing the peroxide value include 1) a method using an adsorbent, 2) a method using a reducing agent, 3) a neutralizing method, and the like. preferable. There are various types of such adsorbents, such as aluminum oxide adsorbents, magnesium oxide adsorbents, aluminum oxide / magnesium oxide adsorbents, silicic acid / aluminum oxide adsorbents, silicic acid / magnesium oxide adsorbents, etc. In any case, it is preferable to use an adsorbent containing aluminum oxide and / or magnesium oxide. In addition, various types of purification methods using such an adsorbent can be mentioned, and an α-allyl-ω-hydroxy-polyoxyalkylene having a peroxide value exceeding 5.0 meq / kg is brought into contact with the adsorbent under heating. The method of making it preferable is. For example, α-allyl-ω-hydroxy-polyoxyalkylene having a peroxide value exceeding 5.0 meq / kg is mixed with an adsorbent under heating at around 100 ° C., and then the mixture is filtered under pressure, and the filtrate is filtered. As a result, α-allyl-ω-hydroxy-polyoxyalkylene purified to a peroxide value of 5.0 meq / kg or less is obtained.

  In the α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 thus purified, A includes: 1) a residue obtained by removing all hydroxyl groups from polyethylene glycol in which the oxyalkylene unit is composed solely of oxyethylene units; 2) Residues obtained by removing all hydroxyl groups from polyethylene polypropylene glycol in which the oxyalkylene unit is composed of both oxyethylene units and oxypropylene units are included. A is a residue obtained by removing all hydroxyl groups from polyethylene glycol. Groups are preferred. When A is a residue obtained by removing all hydroxyl groups from polyethylene polypropylene glycol, the bonding mode of the oxyethylene unit and the oxypropylene unit may be either a random bond and / or a block bond. The number of repeating oxyalkylene units constituting the residue obtained by removing all hydroxyl groups from the polyalkylene glycol represented by A is 2-250, but is preferably 7-95.

  Specific examples of the α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 described above are as follows: 1) α-allyl-ω-hydroxy-polyoxyethylene, 2) α-allyl-ω-hydroxy- ( Poly) oxyethylene (poly) oxypropylene.

  Examples of the aliphatic monocarboxylic acid represented by Chemical Formula 2 include acetic acid, propionic acid, butyric acid, valeric acid, and caproic acid. Among them, acetic acid and propionic acid are preferable.

  In the first step, as described above, α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 that has been purified to have a peroxide value of 5.0 meq / kg or less, and Chemical Formula 2 Aliphatic monocarboxylic acid was esterified while distilling off the produced water using an acid catalyst in the absence of a solvent in the presence of an antioxidant and under reduced pressure conditions. The indicated allyl ether ester monomer is obtained.

  Examples of the antioxidant present in the reaction system include hydroquinone, hydroquinone monomethyl ether, phenothiazine, butylhydroxytoluene, pt-butylcatechol, triphenyl phosphite, tributyl phosphite, among others, hydroquinone, Butylhydroxytoluene and triphenyl phosphite are preferred. These antioxidants can exist in one kind or a mixture of two or more kinds. Further, the amount of the antioxidant present in the reaction system is 0.005 to 0.15 weight of the α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 in order to suitably exhibit the antioxidant effect thereby. % Is preferable.

  The heating condition during the esterification reaction is preferably 100 to 135 ° C., and the pressure condition is preferably 80 to 0.5 kPa. More preferably, the heating condition is such that the temperature is raised gradually or stepwise within the temperature range, and the pressure condition is reduced gradually or stepwise within the pressure range.

  In the esterification reaction, an acid catalyst is used as a catalyst. As such an acid catalyst, sulfuric acid, paratoluenesulfonic acid, phosphoric acid, methanesulfonic acid and the like can be used alone or in combination. Among them, sulfuric acid alone or a mixed acid of sulfuric acid and paratoluenesulfonic acid is used. preferable. The amount of the acid catalyst used is 0.1 to 1.5 weights based on the total amount of α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 and the aliphatic monocarboxylic acid represented by Chemical Formula 2. % Is preferable.

  In the esterification reaction, the raw material ratio of α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 to the aliphatic monocarboxylic acid represented by Chemical Formula 2 is α-allyl-ω-hydroxy represented by Chemical Formula 1. -Polyoxyalkylene / aliphatic monocarboxylic acid represented by Chemical formula 2 = 1 / 1.1 to 1 / 2.5 (molar ratio) is preferable. In this case, excess aliphatic monocarboxylic acid is distilled off after both esterification reactions.

  The first step described above will be described in more detail. When, for example, α-allyl-ω-acetyl-polyoxyethylene is obtained as the allyl ether ester monomer, purification is performed so that the peroxide value is 5.0 meq / kg or less. After the treated α-allyl-ω-hydroxy-polyoxyethylene and excess acetic acid are charged into a reaction vessel, a predetermined amount of antioxidant is added to the charged amount of the α-allyl-ω-hydroxy-polyoxyethylene. Charged with concentrated sulfuric acid as acid catalyst. Next, the esterification reaction is carried out while the generated water is distilled off by azeotropic distillation of water / acetic acid at a predetermined temperature and pressure where the temperature of the reaction system is gradually increased and the pressure is gradually reduced. . After the esterification reaction, excess acetic acid is distilled off to obtain α-allyl-ω-acetyl-polyoxyethylene. The allyl ether ester monomer thus obtained also contains the above-mentioned antioxidant and acid catalyst, but these can be directly used for the second step as an intermediate raw material without being purified and removed.

  Next, the second step will be described. The cement dispersant according to the present invention comprises a graft copolymer and / or a salt thereof, and the graft copolymer is a radical copolymer of the allyl ether ester monomer and maleic anhydride obtained in the first step described above. A vinyl copolymer is obtained by a polymerization reaction, and a polyoxyalkylene monoalkyl ether and / or a polyoxyalkylene monoalkyl ester is further grafted to the vinyl copolymer.

  In particular, when a graft copolymer is produced through the following steps A and B, and further a salt is produced from the graft copolymer, the graft copolymer and / or salt thereof is used as a cement dispersant. When the allyl ether ester monomer obtained in the first step is used, the effect can be exhibited most.

Step A: Allyl ether ester monomer and maleic anhydride obtained in the first step described above are contained in a ratio of allyl ether ester monomer / maleic anhydride = 20/80 to 50/50 (molar ratio). A radical copolymerization reaction of the radical polymerizable monomer mixture to be obtained in the presence of a radical polymerization initiator to obtain a vinyl copolymer having a number average molecular weight of 3000 to 50000.
Step B: With respect to 100 parts by weight of the vinyl copolymer obtained in Step A, ethylene oxide and propylene oxide per mole of aliphatic carboxylic acid having 1 to 6 carbon atoms and / or aliphatic alcohol having 1 to 6 carbon atoms 1 to 40 parts by weight of a polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester added in a block form in a proportion of 2 to 10 moles in the presence of a basic catalyst. To obtain a graft copolymer.

  In step A, a radical polymerization initiator is added to the radical polymerizable monomer mixture to cause a radical copolymerization reaction, and the number average molecular weight (number average molecular weight in terms of pullulan according to GPC method, hereinafter the same) is 3000 to 50000, preferably 5000. A vinyl copolymer of ˜25000 is obtained. A known method can be applied to the radical copolymerization reaction. For example, 1) A method in which a radical polymerizable monomer mixture is subjected to a radical copolymerization reaction without using a solvent, and 2) the radical polymerizable monomer mixture is dissolved in a solvent such as benzene, toluene, xylene, methyl isobutyl ketone, or dioxane. The method of 1) is preferable, and it is more preferable to obtain a vinyl copolymer having a number average molecular weight of 5000 to 25000 by the method of 1). In the method 1), a radical polymerizable monomer mixture is charged into a reaction vessel, a radical polymerization initiator is added to the reaction vessel, and a radical copolymerization reaction is performed at 60 to 90 ° C. for 5 to 10 hours. This is a method for obtaining a polymer. In order to obtain the desired vinyl copolymer by controlling the radical copolymerization reaction by either the method 1) using no solvent or the method 2) using a solvent, there are various types of radical polymerization initiators and radical chain transfer agents. In addition, the amount used, polymerization temperature, polymerization time, etc. are appropriately selected. Examples of the radical polymerization initiator used here include azo initiators such as azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), benzoyl peroxide, and lauroyl peroxide. And organic peroxide initiators such as cumene hydroperoxide.

  Step B is a step in which a polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester is grafted to the vinyl copolymer obtained in Step A to obtain a graft copolymer. As polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester, ethylene oxide and propylene oxide are used per 1 mol of aliphatic alcohol having 1 to 6 carbon atoms and / or aliphatic carboxylic acid having 1 to 6 carbon atoms. What was added to the block shape in the ratio of 2-10 mol in total is used.

  Examples of the aliphatic alcohol having 1 to 6 carbon atoms used as a raw material for the polyoxyalkylene monoalkyl ether to be graft-reacted in Step B include methanol, ethanol, propanol, butanol, pentanol and hexanol. ~ 5 propanol, butanol, pentanol are preferred. In addition, examples of the aliphatic carboxylic acid having 1 to 6 carbon atoms used as a raw material for the polyoxyalkylene monoalkyl ester to be graft-reacted in the second step include acetic acid, propionic acid, butyric acid, valeric acid, and caproic acid. Acetic acid and propionic acid are preferred.

  As polyoxyalkylene monoalkyl ether to be graft-reacted in Step B, those added in block form at a ratio of 1 to 4 mol of ethylene oxide and 1 to 4 mol of propylene oxide per 1 mol of aliphatic alcohol having 3 to 5 carbon atoms. preferable. In addition, the polyoxyalkylene monoalkyl ester to be grafted in the second step is added in block form at a ratio of 1 to 4 mol of ethylene oxide and 1 to 4 mol of propylene oxide per 1 mol of aliphatic carboxylic acid having 3 to 5 carbon atoms. Is preferred. The order in which ethylene oxide and propylene oxide are added in a block form to an aliphatic alcohol or aliphatic carboxylic acid is not particularly limited, but it is preferable to add propylene oxide first and then add ethylene oxide. The polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester described above can be synthesized by a known method.

  In step B, the proportion of polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester is 1 to 40 parts by weight, preferably 3 to 30 parts by weight, per 100 parts by weight of the vinyl copolymer obtained in step A. Graft reaction is carried out at a ratio of 2 to obtain a graft copolymer. A known method can be applied to the graft reaction. For example, the vinyl copolymer obtained in the first step, the polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester, and the esterification catalyst are charged into a reaction can, and the nitrogen atmosphere is set. The graft copolymer can be obtained by performing a graft reaction for 4 to 6 hours. As the esterification catalyst, known catalysts used for the ring-opening esterification reaction between an acid anhydride and an alcohol can be used. Among them, an amine catalyst is preferable, and a lower alkylamine is more preferable.

  The salt of the graft copolymer used as the cement dispersant according to the present invention is obtained by completely or partially using the basic compound of the graft copolymer obtained in the second step described above, preferably the A step and the B step. Obtained by neutralization treatment. Examples of such basic compounds are 1) alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, 2) alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, 3) ammonia, triethanolamine. Examples of these amines include one or two or more of them.

  The cement dispersant according to the present invention comprising the above-described graft copolymer and / or salt thereof is a variety of hydraulic cement compositions including a cement or cement and a fine powder admixture as a binder. Can be applied to mortar and concrete. In this case, examples of the cement include various mixed cements such as blast furnace cement, fly ash cement, and silica fume cement, alumina cement, and the like in addition to various portland cements such as ordinary cement, early-strength cement, and moderately hot portland cement. Examples of the fine powder admixture include limestone powder, calcium carbonate, silica fume, blast furnace slag fine powder, fly ash and the like.

  The cement dispersant according to the present invention is usually 0.01 to 2.5 parts by weight, preferably 0.05 to 100 parts by weight in terms of solid content with respect to 100 parts by weight of cement or a binder composed of cement and fine powder admixture. Used at a ratio of 1.5 parts by weight. The method of use is usually used by adding together with kneaded water when preparing a hydraulic cement composition.

  In the cement dispersant according to the present invention, in the first step, α-allyl-ω-hydroxy-polyoxyalkylene represented by Chemical Formula 1 and Chemical Formula 2, which have been purified so that the peroxide value is 5.0 meq / kg or less, No solvent is used in the esterification reaction with the indicated aliphatic monocarboxylic acid. Therefore, there is no need to recover the solvent after both esterification reactions. In this first step, a high-quality allyl ether ester monomer represented by Chemical formula 3 can be obtained. Highly pure allyl ether ester monomer is obtained with almost no formation of by-products such as allylic adducts produced by oxidative degradation during the esterification reaction, or the formation of glycols or their esters by breaking the polyether chain. It can be done. In the second step, a graft copolymer is obtained using such a high-quality allyl ether ester monomer as an intermediate raw material. This graft copolymer and / or salt thereof has the required performance as a cement dispersant. Demonstrate. The hydraulic cement composition can be provided with excellent fluidity with little slump loss, and the cured product obtained by curing the hydraulic cement composition can be provided with sufficient compressive strength and sufficient resistance to freeze-thaw action at the same time. . When producing the graft copolymer and / or salt thereof as the cement dispersant according to the present invention in the second step, using the high-quality allyl ether ester monomer obtained in the first step as an intermediate raw material, Can be used without using a solvent for allyl ether ester monomer production, vinyl copolymer production, graft copolymer and / or salt production. Does not require consistent solvent recovery.

  According to the present invention, a graft copolymer obtained by producing a high-quality allyl ether ester monomer without using a solvent, and using such a high-quality allyl ether ester monomer as an intermediate material, The salt can exhibit excellent performance as a cement dispersant.

  Hereinafter, in order to make the configuration and effects of the present invention more specific, examples and the like will be described. However, the present invention is not limited to the examples. In the following examples and the like, unless otherwise indicated, parts means parts by weight and% means% by weight.

Test Category 1 (Preparation of α-allyl-ω-hydroxy-polyoxyalkylene)
Preparation of α-allyl-ω-hydroxy-polyoxyalkylene (M-1) 116 g (2.0 mol) of allyl alcohol was charged into an autoclave, and 0.6 g of potassium hydroxide powder was added as a catalyst. Fully replaced with nitrogen. While stirring, the reaction temperature was maintained at 115 to 125 ° C., and 2640 g (60 mol) of ethylene oxide was injected to perform a ring-opening addition reaction. After the ring-opening addition reaction, the mixture was aged at the same temperature for 1 hour. The reaction product was transferred to a flask, 28 g of a silicic acid / aluminum oxide adsorbent (trade name Kyoward 700SL, Kyowa Chemical Industry Co., Ltd.) was added, mixed for 1 hour at a temperature of 110 ° C., cooled to 80 ° C., and then mixed. Α-allyl-ω-hydroxy-poly (30 mol), filtered under pressure using 40 g of filter aid (trade name Topcoperlite, Showa Chemical Industry Co., Ltd.) and purified to a peroxide value of 0.4 meq / kg as a filtrate ) Oxyethylene (M-1) was obtained.

Preparation of α-allyl-ω-hydroxy-polyoxyalkylene (M-2) to (M-5) In the same manner as α-allyl-ω-hydroxy-polyoxyalkylene (M-1), α-allyl- [omega] -Hydroxy-polyoxyalkylenes (M-2) to (M-5) were prepared. The contents of each of the α-allyl-ω-hydroxy-polyoxyalkylenes (M-1) to (M-5) prepared above are shown together in Table 1.

Preparation of α-allyl-ω-hydroxy-polyoxyalkylene (m-1) 1000 g of α-allyl-ω-hydroxy-polyoxyalkylene (M-1) was placed in a 2 L capacity poly container, and the upper space in the container The mixture was sealed in a state in which it was left, and an accelerated test was carried out at 30 ° C. for 30 days to prepare α-allyl-ω-hydroxy-polyoxyalkylene (m-1). The peroxide value of α-allyl-ω-hydroxy-polyoxyalkylene (m-1) was increased to 6.5 meq / kg.

Preparation of α-allyl-ω-hydroxy-polyoxyalkylene (m-2) to (m-5) α-allyl-ω-hydroxy-polyoxyalkylene (M-1) to α-allyl-ω-hydroxy- In the same manner as the preparation of polyoxyalkylene (m-1), α-allyl-ω-hydroxy-polyoxyalkylene (M-2) to (M-5) to α-allyl-ω-hydroxy-polyoxy were prepared. Alkylene (m-2) to (m-5) were prepared. The contents of each α-allyl-ω-hydroxy-polyoxyalkylene (m-1) to (m-5) prepared above are shown together in Table 1.

Preparation of α-allyl-ω-hydroxy-polyoxyalkylene (MS-1) 800 g of α-allyl-ω-hydroxy-polyoxyalkylene (m-1) was placed in a flask and adsorbed with aluminum oxide / magnesium oxide (Kyowa) 4g of chemical industry trade name Kiyoward 300) was added, mixed for 1 hour at a temperature of 110 ° C, cooled to 80 ° C, and then the mixture was used with 16g of filter aid (trade name Topcoperlite of Showa Chemical Industry) Then, the mixture was filtered under pressure, and α-allyl-ω-hydroxy-polyoxyalkylene (MS-1) purified to a peroxide value of 0.9 meq / kg as a filtrate was prepared.

Preparation of α-allyl-ω-hydroxy-polyoxyalkylene (MS-2) to (MS-5) α-allyl-ω-hydroxy-polyoxyalkylene (m-1) to α-allyl-ω-hydroxy- In the same manner as the preparation of polyoxyalkylene (MS-1), α-allyl-ω-hydroxy-polyoxyalkylene (m-2) to (m-5) to α-allyl-ω-hydroxy-polyoxy were prepared. Alkylene (MS-2) to (MS-5) were prepared. The contents of each α-allyl-ω-hydroxy-polyoxyalkylene (MS-1) to (MS-5) prepared above are shown together in Table 1.

Test category 2 (production of allyl ether ester monomers)
Production Example 1 {Production of allyl ether ester monomer (P-1)}
In the reaction vessel, 1378 g (1.0 mol) of α-allyl-ω-hydroxy-polyoxyalkylene (MS-1) prepared in Test Category 1, 96 g (1.6 mol) of acetic acid, 0.069 g of hydroquinone, 98% Concentrated sulfuric acid (concentrated sulfuric acid of the same concentration is used) 2.9g is charged, gradually heated while stirring and depressurized, and the water produced by the esterification reaction as water / acetic acid azeotrope outside the reaction system The esterification reaction was carried out for 4 hours under the conditions of a temperature of 110 ° C. to 130 ° C. and a pressure of 50 to 3.0 kPa. Subsequently, the remaining excess acetic acid was further distilled off under reduced pressure to obtain a product. This product was analyzed and found to be an allyl ether ester monomer (P-1) having a hydroxyl value of 0.7, a carboxyl value of 0.1, and an esterification reaction rate (calculated from the hydroxyl value, the same shall apply hereinafter) of 98%. It was.

Production Examples 2 to 8 {Production of allyl ether ester monomers (P-2) to (P-8)}
In the same manner as in Production Example 1 {allyl ether ester monomer (P-1)}, Production Examples 2 to 8 {Production of allyl ether ester monomers (P-2) to (P-8)} were performed. . The contents of the allyl ether ester monomers (P-1) to (P-8) produced above are shown in Table 2 and Table 3 together.

Production Examples 9 to 13 {Production of allyl ether ester monomers (R-1) to (R-5)}
α-allyl-ω-hydroxy-polyoxyalkylene (m-1) to (m-5) was used in place of α-allyl-ω-hydroxy-polyoxyalkylene (MS-1) to (MS-5). Except for this, allyl ether ester monomers (R-1) to (R-5) were produced in the same manner as in Production Examples 1 to 5.

Production Example 14 {Production of allyl ether ester monomer (R-6)}
An allyl ether ester monomer (R-6) was produced in the same manner as in Production Example 1 except that hydroquinone as an antioxidant was not used.

Production Example 15 {Production of allyl ether ester monomer (R-7)}
An allyl ether ester monomer (R-7) was produced in the same manner as in Production Example 1 except that concentrated sulfuric acid as an esterification catalyst was not used. The contents of each of the allyl ether ester monomers (R-1) to (R-7) produced above are shown together in Tables 4 and 5.

In Table 2 and Table 4,
A-1: Residues obtained by removing all hydroxyl groups from polyethylene glycol having 30 repeating oxyethylene units A-2: Residues obtained by removing all hydroxyl groups from polyethylene glycol having 9 repeating oxyethylene units A-3: Residues obtained by removing all hydroxyl groups from polyethylene glycol having 65 repeats of oxyethylene units A-4: Residues obtained by removing all hydroxyl groups from polyethylene glycols having 90 repeats of oxyethylene units A-5: Residues of oxyethylene units Residues obtained by removing all hydroxyl groups from polypropylene glycol having 90 repeating units and 20 repeating oxypropylene units

In Table 3 and Table 5,
I-1: Hydroquinone I-2: Butylhydroxytoluene I-3: Triphenyl phosphite c-1: 98% concentrated sulfuric acid c-2: 98% concentrated sulfuric acid / paratoluenesulfonic acid = 6/4 (weight ratio) Mixed acid

Test Category 3 (Production of graft copolymer or salt thereof as cement dispersant using allyl ether ester monomer)
Example 1 {Production of Graft Copolymer (D-1)}
176 parts (1.8 moles) of maleic anhydride and 1420 parts (1.0 moles) of the allyl ether ester monomer (P-1) obtained in Test Category 2 were charged into a reaction vessel and uniformly dissolved while stirring. Thereafter, the atmosphere was replaced with nitrogen. The temperature of the reaction system was kept at 80 ° C. in a warm water bath, and 4 parts of azobisisobutyronitrile was added to start the reaction. After the start of the reaction, 8 parts of azobisisobutyronitrile in total were added in portions and the radical polymerization reaction was carried out for 6 hours to complete the radical polymerization reaction. When the obtained vinyl copolymer was analyzed, the number average molecular weight of maleic anhydride / α-allyl-ω-acetyl-polyoxyethylene (P-1) = 64/36 (molar ratio) in terms of raw materials. Was a 13500 copolymer. Next, 100 parts of this copolymer, 16 parts of polyoxyalkylene monoalkyl ether in which 2 moles of ethylene oxide and 2 moles of propylene oxide are added in a block form per mole of butyl alcohol, and 0.8 part of tributylamine as a catalyst are reacted. The container was charged and the atmosphere was replaced with nitrogen. While stirring, the esterification reaction was carried out at 100 ° C. for 4 hours to obtain a graft copolymer (D-1).

Examples 2 to 8 and Comparative Examples 1 to 7 {Production of Graft Copolymers (D-2) to (D-8) and (DR-1) to (DR-7)}
The graft copolymers (D-2) to (D-8) and (DR-1) to (DR-7) were obtained in the same manner as the graft copolymer (D-1).

Example 9 {Preparation of graft copolymer salt (D-9)}
100 parts of the graft copolymer (D-1) obtained in Example 1 was dissolved in 148 parts of water to obtain an aqueous liquid. To this aqueous liquid, 16.7 parts of a 20% aqueous sodium hydroxide solution are gradually added with stirring, and the graft copolymer (D-1) is partially neutralized to obtain a graft copolymer salt (D-9). Prepared.
Table 6 shows the contents of each of the graft copolymers or salts (D-1) to (D-9) and (DR-1) to (DR-7) produced or further prepared in the above examples. Shown together.

In Table 6,
* 1: Types of polyoxyalkylene monoalkyl ether and / or polyoxyalkylene monoalkyl ester * 2: Polyoxyalkylene monoalkyl ether grafted to 100 parts by weight of the copolymer obtained in the first step and / or Or part by weight of polyoxyalkylene monoalkyl ester * 3: It was not possible to measure because some gelled product was generated.
D-9: sodium salt of D-1 e-1: α-butyl-ω-hydroxy-dioxyethylenedioxypropylene e-2: α-butyroyl-ω-hydroxy-dioxyethylenedioxypropylene

Test category 4 (Preparation and evaluation of concrete)
-Preparation of concrete Under the mixing conditions described in Table 7, concrete of each test example was prepared as follows. 50L pan-type forced kneading mixer with ordinary boltland cement (specific gravity = 3.16, brain value 3300), fine aggregate (Oikawa water sand, specific gravity = 2.63) and coarse aggregate (Okazaki crushed stone, specific gravity = 2) .63) were sequentially added and kneaded for 15 seconds. Each test example is composed of a graft copolymer or a salt thereof manufactured or further prepared in Test Category 3 so that the target slump is in the range of 18 ± 1 cm and the target air amount is in the range of 4.5 ± 1%. The cement dispersant was added to the cement in the range of 0.1 to 1.5% by weight in terms of solid content and mixed with water and mixed for 90 seconds.

-Evaluation of concrete About the prepared concrete of each test example, slump, slump residual rate, air volume, freeze-thaw durability index, and compressive strength were evaluated as follows. The results are summarized in Table 8 and Table 9.

-Slump: Measured according to JIS-A1101 immediately after kneading, after 60 minutes and after 90 minutes.
-Slump residual rate: (slump after standing for 90 minutes / slump immediately after mixing) x 100
-Air amount: Measured according to JIS-A1128.
-Freezing and thawing durability index: Measured in accordance with Annex 2 of JIS-A1148, and a numerical value calculated by the durability index of ASTM-C666 is shown. This numerical value indicates that the maximum value is 100, and the closer to 100, the better the resistance to freeze-thaw action.
-Compressive strength: Based on JIS-A1108, material age 3 days and material age 28 days were measured.

In Table 8,
Addition amount: Addition part in terms of solid content with respect to 100 parts of cement * 4: Since the target fluidity could not be obtained even if the addition amount was increased, it was stopped.
* 5: Polycarboxylic acid cement dispersant (Brand name Tupol HP-11, Takemoto Yushi Co., Ltd.)

Claims (10)

A cement dispersant comprising a graft copolymer and / or a salt thereof obtained through the following first step and second step.
First step: α-allyl-ω-hydroxy-polyoxyalkylene represented by the following chemical formula 1 purified to have a peroxide value of 5.0 meq / kg or less, and an aliphatic monoform represented by the following chemical formula 2 Carboxylic acid was subjected to an esterification reaction in the absence of a solvent in the presence of an antioxidant under heating and reduced pressure conditions using an acid catalyst while distilling off the produced water. Obtaining an allyl ether ester monomer.
Second step: After the allyl ether ester monomer obtained in the first step and maleic anhydride are subjected to radical copolymerization reaction to obtain a vinyl copolymer, the vinyl copolymer is subjected to polyoxyalkylene monoalkyl ether and A step of graft-reacting a polyoxyalkylene monoalkyl ester to obtain a graft copolymer.

(In Chemical Formulas 1 through 3,
R: Aliphatic alkyl group having 1 to 6 carbon atoms A: All hydroxyl groups from polyalkylene glycol having 2 to 250 repeating oxyalkylene units consisting of only oxyethylene units or oxyethylene units and oxypropylene units Excluded residues)   The cement according to claim 1, wherein in the first step, α-allyl-ω-hydroxy-polyoxyalkylene purified to have a peroxide value of 3.0 meq / kg or less and an aliphatic monocarboxylic acid are esterified. Dispersant.   In the first step, α-allyl-ω-hydroxy-polyoxyalkylene purified with an adsorbent containing aluminum oxide and / or magnesium oxide and an aliphatic monocarboxylic acid are esterified. 2. The cement dispersant according to 2.   In the first step, α-allyl-ω-hydroxy-polyoxyalkylene and an aliphatic monocarboxylic acid are converted into the α-allyl-ω-hydroxy-polyoxyalkylene / the aliphatic monocarboxylic acid = 1 / 1.1. The cement dispersant according to any one of claims 1 to 3, wherein excess aliphatic monocarboxylic acid is distilled off after esterification by using at a ratio of ~ 1 / 2.5 (molar ratio). .   In the first step, one or more selected from hydroquinone, butylhydroxytoluene and triphenyl phosphite is used as the antioxidant, and the antioxidant is α-allyl-ω-hydroxy-polyoxyalkylene. The cement dispersant according to any one of claims 1 to 4, which is present in an amount corresponding to 0.005 to 0.15% by weight.   In the first step, α-allyl-ω-hydroxy-polyoxyalkylene and an aliphatic monocarboxylic acid are esterified at a temperature of 100 to 135 ° C and a pressure of 80 to 0.5 kPa. The cement dispersing agent as described in any one of -5.   In the first step, the α-allyl-ω-hydroxy-polyoxyalkylene and the aliphatic monocarboxylic acid are heated gradually or stepwise within a temperature range of 100 to 135 ° C., and 80 to 0 The cement dispersant according to any one of claims 1 to 5, wherein the esterification reaction is carried out under a pressure reduced gradually or stepwise within a pressure range of 0.5 kPa.   In the first step, the acid catalyst is used in a proportion of 0.1 to 1.5% by weight based on the total amount of α-allyl-ω-hydroxy-polyoxyalkylene and aliphatic monocarboxylic acid. The cement dispersant according to any one of the above.   The cement dispersion according to any one of claims 1 to 8, wherein in the first step, α-allyl-ω-hydroxy-polyoxyalkylene is used in which A in Chemical Formula 1 is composed of only oxyethylene units. Agent. The cement dispersant according to any one of claims 1 to 9, wherein acetic acid or propionic acid is used as the aliphatic monocarboxylic acid in the first step.