JPH0822770B2 - Cement dispersant - Google Patents

Description

The present invention relates to a cement dispersant having a slump loss preventing property, and more specifically, it is added to a cement composition such as cement mortar or concrete to enhance its fluidity. Moreover, the fluidity decreases with time (hereinafter referred to as slump loss).
The present invention relates to a drug that prevents the above and improves the workability.

(Prior Art) Cement compositions such as mortar and concrete have a decrease in consistency with the lapse of time after mixing due to a hydration reaction between cement and water, resulting in a decrease in workability. This phenomenon is generally called slump loss.

The slump loss in the cement composition causes obstacles such as limitation of transportation time, quality change due to waiting time at the setting site, poor workability, deterioration of durability due to cold joint, etc. in ready-mixed concrete. Also, at a concrete secondary product manufacturing plant, etc., the cause of an accident such as a sudden increase in the pumping pressure or a blockage of the pump when the pumping of the cement composition was temporarily interrupted due to a lunch break or a trouble and then the pumping was restarted. If, after the cement composition is cast into the mold, the molding such as compaction is delayed for some reason, problems such as unfilling occur. Therefore, slump loss in the cement composition, in the ready-mixed concrete factory, secondary product manufacturing factory, etc.
It is an important issue that must be solved in order to improve the quality control and workability of cement compositions.

Conventionally, the following methods have been known as measures for preventing slump loss.

B) A method of increasing the unit water volume of concrete.

B) A method in which a cement dispersant is added later.

C) A method in which a cement dispersant is repeatedly added.

D) A method in which a setting retarder is added or combined with a cement dispersant.

Method (a) above is a method of increasing the unit amount of water in anticipation of slump loss until the cement composition is placed. However, although the workability can be improved by this, the strength of the cured product is reduced and the dryness is reduced. This is accompanied by a quality disadvantage that cracking due to shrinkage causes deterioration of durability or an economical disadvantage that the unit cement amount is increased to obtain a predetermined strength.

The method (b) is a temporary measure for improving the fluidity, and the cement dispersant remains locally in the cement composition even after the purpose of maintaining the slump is finished, resulting in local breathing, and eventually strength. It causes adverse effects such as deterioration.

The method (c) is a method of re-adding the admixture at the time of slump loss, and does not completely prevent slump loss. In addition, there is a disadvantage in workability and economical efficiency of repeated addition.

The method (d) is to delay the setting time of the cement composition and maintain the fluidity by delaying the oxycarboxylate, lignin sulfonate, dextrin, humic acid or the like alone or in combination with the cement dispersant. However, in the case of excessive addition, there is a great risk of causing an accident such as strength reduction or curing failure.

Thus, each method has its own drawbacks,
There were practical problems.

(Problems to be Solved by the Invention) As a result of intensive studies, the present inventors have studied the above-mentioned drawbacks and added to a cement composition to improve its fluidity and prevent slump loss. The inventors have found that a specific polymer is effective and arrived at the present invention.

(Means and Actions for Solving Problems) That is, the present invention provides maleic acid, maleic anhydride,
One or more unsaturated dicarboxylic acid type monomers (a) selected from the group consisting of fumaric acid, itaconic acid and itaconic anhydride, and other monomers copolymerizable with these monomers ( B) and unsaturated dicarboxylic acid type monomer (a) 10 to 10
Carboxyl group-containing weight derived using a ratio of 0 mol% and monomer (b) 90 to 0 mol% (however, the sum of monomers (a) and (b) is 100 mol%). In the compound (A), an alkyleneimine having 2 to 4 carbon atoms and optionally an alkylene oxide having 2 to 4 carbon atoms are added, and the number of moles of alkyleneimine added is 1 mole of the carboxyl group in the carboxyl group-containing polymer (A). The present invention relates to a cement dispersant containing a water-soluble polymer (I) obtained by an addition reaction in an average ratio of 0.1 to 10 mol.

In this addition reaction, alkyleneimine and alkylene oxide can be co-added in addition to alkyleneimine alone addition. In the case of coaddition, they are simultaneously added to the carboxyl group-containing polymer (A) and reacted. It is also possible to carry out the reaction sequentially, for example, first by reacting the alkyleneimine and then adding the alkylene oxide. Of these, the latter sequential co-addition reaction method is preferable, considering the ease of control of the reaction and the performance of the resulting water-soluble polymer (I) as a cement dispersant.

Therefore, as the water-soluble polymer (I) effective as the cement dispersant of the present invention, an unsaturated dicarboxylic acid-based monomer selected from the group consisting of maleic acid, maleic anhydride, fumaric acid, itaconic acid and itaconic anhydride is used. An unsaturated dicarboxylic acid-based monomer (a) comprising one or more types of the body (a) and another monomer (b) copolymerizable with these monomers
~ 100 mol% and the monomer (b) 90 to 0 mol% (however, the total of the monomers (a) and (b) is 100 mol%) and the derived carboxyl group-containing Polymer (A)
With respect to 1 mol of the carboxyl group in the polymer (A)
Aminoalkylated polymer (II) obtained by reacting alkyleneimine having 2 to 4 carbon atoms at a ratio of 0.1 to 10 mol and / or the polymer (II) is further reacted with alkylene oxide having 2 to 4 carbon atoms. It is preferable to employ the polymer (III) thus obtained.

The monomer (b) used in the present invention is another monomer copolymerizable with the unsaturated dicarboxylic acid monomer (a).
Examples of the monomer (b) include monovalent metal salts of unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid and fumaric acid,
A divalent metal salt, an ammonium salt or an organic amine salt; an aliphatic alcohol having 1 to 20 carbon atoms, a glycol having 2 to 4 carbon atoms, or an addition mole number of these glycols of 2
100 polyalkylene glycols or alkoxy (poly) alkylene glycols derived from these glycols or polyalkylene glycols and aliphatic alcohols having 1 to 5 carbon atoms and unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, fumaric acid Monoesters or diesters with; acetic acid alkenyl esters such as vinyl acetate and propenyl acetate; aromatic vinyls such as styrene, p-methylstyrene and styrenesulfonic acid; 2-acrylamido-
Unsaturated sulfonic acids such as 2-methylpropanesulfonic acid, 2-sulfoethyl (meth) acrylate, vinylsulfonic acid, allylsulfonic acid and salts thereof; (meth) acrylamide, N-methyl (meth) acrylamide, N, N
-(Meth) acrylamides such as dimethyl (meth) acrylamide, N- (meth) acryloylpiperidine, N- (meth) acryloylmorpholine; unsaturated hydrocarbons such as ethylene and propylene; vinyl chloride and the like. 1 type or 2 types or more of these can be used.

The monomer (b) is in a range of 90 mol% or less based on the total amount of the monomer (a) and the monomer (b) within a range in which the obtained carboxyl group-containing polymer (A) is water-soluble. It is used in. When the monomer (b) is used in a ratio of more than 90 mol%, the finally obtained water-soluble polymer (I), aminoalkylated polymer (II) or polymer (III) has a poor cement dispersibility. Will be enough.

In order to produce the carboxyl group-containing polymer (A), the monomer component may be polymerized using a polymerization initiator.
The polymerization can be carried out by a method such as polymerization in a solvent or bulk polymerization.

Polymerization in a solvent can be carried out batchwise or continuously, and the solvent used in this case is water; lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n. -Aromatic or aliphatic hydrocarbons such as hexane; ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone. From the viewpoint of the solubility of the raw material monomer and the obtained carboxyl group-containing polymer (A) and the ease of handling during the reaction between the carboxyl group-containing polymer (A) and the alkyleneimine, water and a carbon number of 1 to 1 are obtained. It is preferable to use at least one selected from the group consisting of 4 lower alcohols. Among the lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol and isopropyl alcohol are particularly effective.

When carrying out the polymerization in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide is used as the polymerization initiator. At this time, a promoter such as sodium bisulfite may be used in combination.
For polymerization using lower alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, ethyl acetate or ketone compounds as solvents, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; azo Aliphatic azo compounds such as bisisobutyronitrile are used as a polymerization initiator.
At this time, an accelerator such as an amine compound may be used in combination. Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected and used from the above various polymerization initiators or a combination of a polymerization initiator and an accelerator.
The polymerization temperature is appropriately determined depending on the solvent and the polymerization initiator used, but it is usually in the range of 0 to 120 ° C.

Bulk polymerization uses a peroxide such as benzoyl peroxide or lauroyl peroxide as a polymerization initiator; a hydroperoxide such as cumene hydroperoxide; an aliphatic azo compound such as azobisisobutyronitrile or the like at 50 to 150 ° C. It is performed within a temperature range.

The water-soluble polymer (I) effective as a cement dispersant of the present invention is obtained by adding an alkyleneimine having 2 to 4 carbon atoms and optionally an alkylene oxide having 2 to 4 carbon atoms to the obtained carboxyl group-containing polymer (A). It can be obtained by reacting.

Examples of the alkyleneimine having 2 to 4 carbon atoms used in the present invention include various ones.
Propylene imine is mentioned as a suitable example.

The reaction of the carboxyl group-containing polymer (A) with the alkyleneimine is carried out using the alkyleneimine in a ratio of 0.1 to 10 mol with respect to 1 mol of the carboxyl group in the carboxyl group-containing polymer (A). Reaction temperature is usually 0
At 120 ℃, the reaction proceeds without catalyst.

Thus, the carboxyl group-containing polymer (A) is reacted with an alkyleneimine to obtain an aminoalkylated polymer (II), and if necessary, further reacted with an alkylene oxide having 2 to 4 carbon atoms to give a product. The polymer (III) effective as the cement dispersant of the invention may be used.

Examples of the alkylene oxide optionally used in the present invention include various ones, ethylene oxide,
Propylene oxide is mentioned as a suitable example.

The reaction between the aminoalkylated polymer (II) and the alkylene oxide can be carried out by a known method, and preferably the alkylene oxide is reacted in a ratio such that the addition mole number is within 20 times the addition mole number of the alkyleneimine. .

The water-soluble polymer (I) thus obtained, for example, aminoalkylated polymer (II) and / or polymer (III)
Is used as it is as an active ingredient of the cement dispersant, but it may be used as an active ingredient of the cement dispersant after further neutralization with an alkaline substance or an acidic substance, if necessary.

As such alkaline substances, hydroxides, oxides and carbonates of monovalent metals such as sodium and potassium and divalent metals such as calcium, magnesium and zinc; ammonia, organic amines and the like, and as acidic substances Monovalent and divalent organic acids and inorganic acids are preferred.

The water-soluble polymer (I) may have a wide range of molecular weight, but the preferred molecular weight range for the cement dispersant is
It is in the range of 1000 to 500000.

The cement dispersant of the present invention can also be used in combination with other known cement admixtures containing the water-soluble polymer (I) as an essential component.

Examples of such known cement admixtures include conventional cement dispersants, air entraining agents, cement wetting dispersants, waterproofing agents, strength enhancers, and hardening accelerators.

The cement dispersant of the present invention is Portland cement,
It can be used for hydraulic cements such as alumina cement and various mixed cements, or hydraulic materials other than cements such as gypsum.

Examples of the method for using the cement dispersant of the present invention include, for example, a method of dissolving it in kneading water and then adding it together with the kneading water at the time of preparing the cement composition, or a method of adding it to the already kneaded cement composition. The method can also be adopted.

The use amount of the cement dispersant of the present invention is 0.005% to solid content weight% with respect to the cement in the cement composition.
2.5% is good. If it is less than 0.005%, sufficient slump loss prevention performance may not be obtained. Also, if the amount exceeds 2.5%, it may be economically disadvantageous and may cause problems such as delay in setting and excessive amount of entrained air.

[Effects of the Invention] The cement dispersant of the present invention exhibits high fluidity without giving a large hardening retardation property to cement compositions such as cement mortar and concrete, and has excellent slump loss prevention performance. Therefore, the workability is significantly improved in mortar construction and concrete construction.

Therefore, it goes without saying that the cement dispersant of the present invention can be effectively used as a fluidizing agent for concrete such as ready-mixed concrete,
In particular, it is possible to easily realize the production of ready-mixed concrete with a high water reduction ratio as a high-performance AE water reducing agent for simultaneous plant addition. Further, it can be effectively used as a high-performance water reducing agent for the production of secondary concrete products.

[Examples] Next, the cement dispersant of the present invention will be described in more detail with reference to Reference Examples and Examples, but of course the present invention is not limited thereto. In the examples, unless otherwise specified,% means% by weight, and part means part by weight.

Reference Example 1 Maleic anhydride was added to a steel autoclave equipped with a stirrer, a thermometer, a pressure gauge, and two gas introduction pipes.
Parts, benzoyl peroxide 15.0 parts and dichloroethane 875
A portion was taken, and while stirring the inside of the container, pressurization and depressurization of 10 kg / cm ² with ethylene were repeated several times, and the atmosphere was sufficiently replaced with air. Add ethylene and maintain at 20-30Kg / cm ² at 70 ℃
The polymerization reaction was carried out for 10 hours. The reaction product can be easily taken out and dried in vacuum to obtain 95.1 parts of the carboxyl group-containing polymer (1).

The composition ratio of maleic anhydride and ethylene in the carboxyl group-containing polymer (1) thus obtained was analyzed by titration with an aqueous sodium hydroxide solution. As a result, maleic anhydride: ethylene = 29: 71 (molar ratio) Met. The number average molecular weight of the carboxyl group-containing polymer (1) was measured by high performance liquid chromatography.
000.

Next, 95.1 parts of the carboxyl group-containing polymer (1) and 403.2 parts of water were charged into a glass reaction container equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube and a reflux condenser, and the inside of the reaction container was stirred. Replace with nitrogen and heat in nitrogen atmosphere
It was kept at 80 ° C. for 2 hours to obtain an aqueous solution of the carboxyl group-containing polymer (1). Next, 39.3 parts of ethyleneimine was added to this aqueous solution over 1 hour while cooling this aqueous solution and keeping it at 40 ° C. After the addition was completed, the temperature was raised to 90 ° C, and this temperature was maintained for 120 minutes to complete the addition reaction, and the aminoethylated polymer (1)
An aqueous solution of

The aminoethylation rate of this aminoethylated polymer (1) was determined by quantifying unreacted carboxyl groups by conductivity titration, and as a result, the aminoethylated polymer (1) was obtained.
The number of moles of the ethyleneimine reaction per mole of the carboxyl group therein was 0.8. The viscosity of the aqueous solution of the aminoethylated polymer (1) (B-type viscometer, measured at 25 ° C)
Was 43.5 cps.

Reference Example 2 89 parts of maleic anhydride, 7.5 parts of benzoyl peroxide and 875 parts of dichloroethane were placed in an autoclave similar to that used in Reference Example 1, and ethylene was added to the autoclave while stirring the inside of the container.
The pressurization and depressurization of 0 kg / cm ² were repeated several times, and the air was sufficiently replaced. Further, ethylene was added and the reaction was carried out at 70 ° C. for 10 hours while maintaining at ²⁰ to 30 kg / cm ² . The reaction product was easily taken out and dried under vacuum to obtain 102.6 parts of a carboxyl group-containing polymer (2).

The composition ratio of maleic anhydride and ethylene in the carboxyl group-containing polymer (2) thus obtained was analyzed, and the result was maleic anhydride: ethylene = 30.2: 69.8 (molar ratio).

The number average molecular weight of the carboxyl group-containing polymer (2) measured by high performance liquid chromatography was 45,000.

Next, the same glass reaction container as used in Reference Example 1 was charged with 102.6 parts of the carboxyl group-containing polymer (2) and 438 parts of water, the inside of the reaction container was replaced with nitrogen while stirring, and the mixture was heated in a nitrogen atmosphere. Then, the mixture was kept at 80 ° C. for 2 hours to obtain an aqueous solution of the carboxyl group-containing polymer (2). Next, while the aqueous solution was cooled and kept at 40 ° C., 43.4 parts of ethyleneimine was added thereto over 1 hour. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was kept for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (2).

The properties of this aminoethylated polymer (2) are shown in Reference Example 1
The measurement was conducted in the same manner as in, and the results are shown in Table 1.

Reference Example 3 89 parts of maleic anhydride, 2.5 parts of benzoyl peroxide and 875 parts of dichloroethane were placed in an autoclave similar to that used in Reference Example 1, and ethylene was added to the autoclave while stirring the inside of the container with ethylene.
The pressurization and depressurization of 0 kg / cm ² were repeated several times, and the air was sufficiently replaced. Further, ethylene was added and the reaction was carried out at 70 ° C. for 10 hours while maintaining at ²⁰ to 30 kg / cm ² . The reaction product was easily taken out and dried in vacuum to obtain 110.5 parts of a carboxyl group-containing polymer (3).

As a result of analyzing the constitutional ratio of maleic anhydride and ethylene in the carboxyl group-containing polymer (3) thus obtained, maleic anhydride: ethylene was 41:59 (molar ratio).

Further, the number average molecular weight of the carboxyl group-containing polymer (3) was measured by high performance liquid chromatography, and it was 96,000.

Next, in a glass reaction vessel similar to that used in Reference Example 1, 110.5 parts of the carboxyl group-containing polymer (3) and 496.5 parts of water were added.
Part of the reaction mixture was charged, the inside of the reaction vessel was replaced with nitrogen under stirring, the mixture was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours to obtain an aqueous solution of the carboxyl group-containing polymer (3). Next, while the aqueous solution was cooled and kept at 40 ° C., 55.0 parts of ethyleneimine was added thereto over 1 hour. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (3). The properties of this aminoethylated polymer (3) were measured in the same manner as in Reference Example 1,
The results are shown in Table 1.

Reference Example 4 89 parts of maleic anhydride, 0.5 parts of benzoyl peroxide and 875 parts of dichloroethane were placed in the same autoclave as used in Reference Example 1, and ethylene was added to the autoclave while stirring the inside of the container.
The pressurization and depressurization of 0 kg / cm ² were repeated several times, and the air was sufficiently replaced. Further, ethylene was added and the reaction was carried out at 70 ° C. for 10 hours while maintaining at ²⁰ to 30 kg / cm ² . The reaction product can be easily taken out and dried in vacuum to obtain 128.1 parts of a carboxyl group-containing polymer (4).

The carboxy group-containing polymer (4) thus obtained was analyzed for the composition ratio of maleic anhydride and ethylene, and the result was maleic anhydride: ethylene = 49: 51 (molar ratio).

Further, the number average molecular weight of the carboxyl group-containing polymer (4) was measured by high performance liquid chromatography, and it was 300,000.

Next, in a glass reaction vessel similar to that used in Reference Example 1, 128.1 parts of the carboxyl group-containing polymer (4) and 592.5 of water were added.
The contents were charged, the inside of the reaction vessel was replaced with nitrogen under stirring, the mixture was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours to obtain an aqueous solution of the carboxyl group-containing polymer (4). Next, 69.4 parts of ethyleneimine was added to this aqueous solution over 1 hour while cooling and maintaining this aqueous solution at 40 ° C. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (4). The properties of this aminoethylated polymer (4) were measured in the same manner as in Reference Example 1,
The results are shown in Table 1.

Reference Example 5 To the same glass reaction container used in Reference Example 1, 45.0 parts of the carboxyl group-containing polymer (1) obtained in the same manner as in Reference Example 1 and 728.1 parts of water were added, and the reaction container was stirred. The inside was replaced with nitrogen, and the mixture was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours. Next, 197.7 parts of ethyleneimine was added thereto over 1 hour while cooling and maintaining at 40 ° C. 90 after addition
The temperature was raised to 0 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (5).
The properties of this aminoethylated polymer (5) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 6 To the same glass reaction container used in Reference Example 1, 127.2 parts of the carboxyl group-containing polymer (4) obtained in the same manner as in Reference Example 4 and 459 parts of water were added, and the reaction container was stirred. The inside was replaced with nitrogen, and the mixture was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours. Next, 25.8 parts of ethyleneimine was added thereto over 1 hour while cooling and maintaining at 40 ° C. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (6). The properties of this aminoethylated polymer (6) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 7 The same glass reaction container as used in Reference Example 1 was charged with 136.3 parts of maleic anhydride and 221.3 parts of methyl ethyl ketone, and the inside of the reaction container was replaced with nitrogen while stirring and heated to 92 ° C. in a nitrogen atmosphere. . Then, a mixture of 144.9 parts of styrene and 144.9 parts of methyl ethyl ketone and 13.9 parts of benzoyl peroxide and 55.6 parts of methyl ethyl ketone.
A mixture of parts was added in 120 minutes. 60 after the addition is complete
The temperature was kept at 92 ° C for a minute to complete the polymerization reaction. When the reaction product was evaporated, 280.7 parts of a carboxyl group-containing polymer (5) was obtained.

The number average molecular weight of the carboxyl group-containing polymer (5) thus obtained was measured and found to be 35,000.

Next, 280.7 parts of the carboxyl group-containing polymer (5) and 1076 parts of water were charged into the same reaction vessel as used in the above reaction, the inside of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated in a nitrogen atmosphere to 40 While maintaining at ℃, add ethyleneimine 78.0
Parts were added in 1 hour. After the addition was completed, the temperature was raised to 90 ° C and 120
This temperature was kept for a minute to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (7). The properties of this aminoethylated polymer (7) were measured in the same manner as in Reference Example 1,
The results are shown in Table 1.

Reference Example 8 To the same glass reaction container used in Reference Example 1, 282.5 parts of a carboxyl group-containing polymer (5) obtained in the same manner as in Reference Example 7 and 1083 parts of water were added, and the reaction container was stirred. The inside was replaced with nitrogen, and the mixture was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours. Next, 29.4 parts of ethyleneimine was added thereto over 1 hour while cooling and maintaining the temperature at 40 ° C. 90 ℃ after addition
The temperature was raised to 120 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (8). The properties of this aminoethylated polymer (8) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 9 The same glass reaction container used in Reference Example 1 was charged with 317.3 parts of polyethylene glycol monoallyl ether (containing 5 ethylene oxide units per molecule on average) and 88.5 parts of water, and the reaction container was stirred. The inside was replaced with nitrogen and heated to 95 ° C. in a nitrogen atmosphere. Then maleic anhydride 139.3 parts, ammonium persulfate 11.1 parts and water 2
A mixture of 09 parts was added in 120 minutes, followed by a mixture of 27.8 parts ammonium persulfate and 111.2 parts of water in 60 minutes. After the addition was completed, the temperature was kept at 95 ° C. for 90 minutes to complete the polymerization reaction, and an aqueous solution of the carboxyl group-containing polymer (6) was obtained. The number average molecular weight of the carboxyl group-containing polymer (6) thus obtained was measured and found to be 3,000.

Next, the temperature of the polymerization reaction product was cooled to 40 ° C., and 76.5 parts of ethyleneimine was added thereto over 1 hour. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (9). The properties of this aminoethylated polymer (9) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 10 Carboxyl group-containing polymer (6) obtained in the same manner as in Reference Example 9 in the same glass reaction container used in Reference Example 1.
904.2 parts of an aqueous solution of was added, the inside of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours. Then, the mixture was cooled and kept at 40 ° C., and 28.7 parts of ethyleneimine was added thereto over 1 hour. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (10). The properties of this aminoethylated polymer (10) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 11 The same glass reaction container used in Reference Example 1 was charged with 400 parts of the aqueous solution of the aminoethylated polymer (1) obtained in Reference Example 1, and the inside of the reaction container was replaced with nitrogen while stirring, Heat to 50 ° C. in a nitrogen atmosphere. On the other hand, 15.0 parts of gaseous ethylene oxide was bubbled from an ethylene oxide cylinder on a measuring instrument into an aqueous solution of aminoethylated polymer (1) through a gas introduction tube to carry out an addition reaction. The bubbling time was 60 minutes. Then, the temperature was maintained at 50 ° C. for 4 hours to complete the reaction, and an aqueous solution of the ethylene oxide-added aminoethylated polymer (11) was obtained. The properties of this aminoethylated polymer (11) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 12 The same glass reaction container as used in Reference Example 1 was charged with 136.3 parts of maleic anhydride and 228.5 parts of methyl ethyl ketone, the inside of the reaction container was replaced with nitrogen with stirring, and the mixture was heated to 92 ° C. in a nitrogen atmosphere. Then a mixture consisting of 119.7 parts of vinyl acetate and 119.7 parts of methyl ethyl ketone and 13.9 parts of benzoyl peroxide and 55.6 parts of methyl ethyl ketone.
A mixture of parts was added in 120 minutes. 60 after the addition is complete
The temperature was kept at 92 ° C for a minute to complete the polymerization reaction. When the reaction product was evaporated, 253.1 parts of a carboxyl group-containing polymer (7) was obtained. The number average molecular weight of the carboxyl group-containing polymer (7) thus obtained was measured and found to be 26,000.

Next, 253.1 parts of the carboxyl group-containing polymer (7) and 1050 parts of water were charged into the same reaction vessel used in the above reaction, and the inside of the reaction vessel was replaced with nitrogen while stirring and heated in a nitrogen atmosphere. Ethyleneimine 96.9
Parts were added in 1 hour. After the addition was completed, the temperature was raised to 90 ° C and 120
This temperature was kept for a minute to complete the addition reaction to obtain an aqueous solution of aminoethylated polymer (12). The properties of this aminoethylated polymer (12) were measured in the same manner as in Reference Example 1,
The results are shown in Table 1.

Reference Example 13 37.7 parts of dodecene and maleic anhydride in a glass reaction vessel equipped with a thermometer, a stirrer, a gas introduction tube and a reflux condenser.
Charge 5.90 parts and benzoyl peroxide 0.40 parts,
Replace the inside of the reaction vessel with nitrogen while stirring, and use 100 in a nitrogen atmosphere.
The mixture was heated to 0 ° C. and kept at this temperature for 4 hours to complete the polymerization reaction. The number average molecular weight of the carboxyl group-containing polymer thus obtained was measured and found to be 17,000.

Next, the temperature of the polymerization reaction product is cooled to 30 ° C., and water 14
3.3 parts was added and heated to 40 ° C. To this was added 4.15 parts of ethyleneimine in 1 hour. After the addition was completed, the temperature was raised to 90 ° C and kept at this temperature for 120 minutes to complete the addition reaction,
An aqueous solution of aminoethylated polymer (13) was obtained. The properties of this aminoethylated polymer (13) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 14 The same glass reaction container used in Reference Example 1 was charged with 95.1 parts of an aqueous solution of a carboxyl group-containing polymer (1) obtained in the same manner as in Reference Example 1 and 441.3 parts of water, and the mixture was stirred. Replace the inside of the reaction vessel with nitrogen and heat in a nitrogen atmosphere.
Hold at 80 ° C for 2 hours, then cool to 40 ° C. To this 40
While maintaining the temperature at 0 ° C, 52.0 parts of propyleneimine was added over 1 hour. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 180 minutes to complete the addition reaction to obtain an aqueous solution of aminopropylated polymer (14). The properties of this aminopropylated polymer (14) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Reference Example 15 95.1 parts of the carboxyl group-containing polymer (1) obtained in Reference Example 1 and 403.2 parts of water were charged into the same glass reaction container used in Reference Example 1, and the inside of the reaction container was replaced with nitrogen while stirring. Then, it was heated in a nitrogen atmosphere and kept at 80 ° C. for 2 hours to obtain an aqueous solution of the carboxyl group-containing polymer (1). Next, this aqueous solution was cooled and kept at 40 ° C., 15.4 parts of gaseous ethylene oxide was added from a ethylene oxide cylinder on a measuring instrument through a gas inlet pipe, and 39.3 parts of ethyleneimine were simultaneously added from a dropping funnel in 1 hour respectively. . After the addition is complete
Raise the temperature to 50 ° C, hold this temperature for 120 minutes, then 90 ° C
The temperature was raised to 120 ° C., and this temperature was maintained for 120 minutes to complete the reaction, to obtain an aqueous solution of aminoethylated polymer (15) to which ethylene oxide was co-added. The properties of this aminoethylated polymer (15) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Comparative Reference Example 1 To the same glass reaction container used in Reference Example 1, 5.0 parts of the carboxyl group-containing polymer (1) obtained in the same manner as in Reference Example 1 and 712.8 parts of water were added and heated to 40 ° C. did. To this, 232.6 parts of ethyleneimine was added over 4 hours. After the addition was completed, the temperature was raised to 90 ° C., and this temperature was maintained for 8 hours to complete the addition reaction to obtain an aqueous solution of the aminoethylated polymer (1) for comparison. The properties of this comparative aminoethylated polymer (1) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Comparative Reference Example 2 Carboxyl group-containing polymer (1) obtained in the same manner as in Reference Example 1 in the same glass reaction container used in Reference Example 1.
96.7 parts and 297.6 parts of water were added and it heated at 40 degreeC. To this, 2.50 parts of ethyleneimine was added over 1 hour. 90 after addition
The temperature was raised to 0 ° C., and this temperature was maintained for 120 minutes to complete the addition reaction to obtain an aqueous solution of the aminoethylated polymer for comparison (2). The properties of this comparative aminoethylated polymer (2) were measured in the same manner as in Reference Example 1, and the results are shown in Table 1.

Example 1 Ordinary Portland cement (produced by Sumitomo Cement Co., Ltd.) as cement, and Yodogawa-produced river sand (specific gravity 2.51, as fine aggregate)
Coarse grain ratio [FM] 2.78), Takatsuki crushed stone (specific gravity) as coarse aggregate
2.68, coarse particle ratio [FM] 6.73) and using the aminoethylated polymer (1) obtained in Reference Example 1 as a cement dispersant,
Unit cement amount 320Kg / m ³ , unit water amount 166Kg / m ³ (water / cement ratio 51.9%), unit fine aggregate amount 890Kg / m ³ , unit coarse aggregate amount
841Kg / m ³ (fine aggregate ratio 49%) and cement dispersant addition amount
With the composition of 0.35% (to cement), each material was weighed so that the kneading amount was 30, and all the materials were put into a tilting mixer. Immediately kneading for 3 minutes at a rotation speed of 35 rpm, target slump 18 cm, target air amount 4.5% (if the target air amount is not reached, a small amount of air entraining agent "Vinsol" manufactured by Yamamune Chemical Co., Ltd. ) Was prepared. The fluidized concrete obtained immediately after kneading was sampled, and its slump and air content were measured.

After kneading, the rotation speed of the tilting mixer was reduced to 3 rpm and kneading was continued, and after 60 minutes, the slump and the air amount were measured, and the changes with time were observed.

The compressive strength and setting time of the fluidized concrete obtained were also measured. The results of these measurements are shown in Table 2.

The methods for measuring the slump, the amount of air, the compressive strength and the setting time and the method for collecting the compressive strength specimens were all in accordance with Japanese Industrial Standards (JIS A6204).

Examples 2 to 15 As a cement dispersant, aminoethylated polymers (2) to (13) and (15) obtained in Reference Examples 2 to 15 as shown in Table 2 and aminopropylated polymers ( 14) except that each of them was used in the addition amount shown in Table 2 to prepare fluidized concrete by repeating the same operation as in Example 1, and adjusting the slump, air content, compressive strength and setting time of the fluidized concrete. It was measured. The measurement results are shown in Table 2.

Comparative Example 1 Example 1 was repeated except that a commercially available naphthalenesulfonic acid sodium salt formalin condensate was used in place of the aminoethylated polymer (1) in Example 1 as a cement dispersant with an addition amount of 0.4% (relative to cement). The same operation was repeated to prepare a fluidized concrete for comparison, and its slump, air content, compressive strength and setting time were measured. The measurement results are shown in Table 2.

Comparative Example 2 Sodium polyacrylate (number average molecular weight 11000) was used in place of the aminoethylated polymer (1) in Example 1.
Was used as a cement dispersant with an addition amount of 0.3% (relative to cement), and the same procedure as in Example 1 was repeated to prepare a fluidized concrete for comparison, and its slump, air content, compressive strength and setting property were set. The time was measured. The measurement results are shown in Table 2.

Comparative Example 3 In place of the aminoethylated polymer (1) in Example 1, the comparative aminoethylated polymer (1) obtained in Comparative Reference Example 1 was added as a cement dispersant in an amount of 0.42% (relative to cement). The same operation as in Example 1 was repeated except that it was used to prepare a fluidized concrete for comparison, and its slump, air content, compressive strength and setting time were measured. The measurement results are shown in Table 2.

Comparative Example 4 In place of the aminoethylated polymer (1) in Example 1, the comparative aminoethylated polymer (2) obtained in Comparative Reference Example 2 was added as a cement dispersant in an amount of 0.40% (relative to cement). The same operation as in Example 1 was repeated except that it was used to prepare a fluidized concrete for comparison, and its slump, air content, compressive strength and setting time were measured. The measurement results are shown in Table 2.

From the results shown in Table 2, it is clear that the cement dispersant of the present invention exhibits an excellent slump loss preventing property with almost no retardation of setting.

On the other hand, the naphthalenesulfonic acid sodium salt formalin condensate of Comparative Example 1 has a very large slump loss. In addition, each of the dispersants of Comparative Examples 2 to 4 has a small slump immediately after kneading and is inferior in cement dispersibility. Further, the sodium polyacrylate of Comparative Example 2 and the comparative aminoethylated polymer (2) of Comparative Example 4 show significant curing delay.

Continuation of the front page (72) Inventor Sadanori Sano 5-8 Nishiomitabicho Suita City Osaka Prefecture Examiner, Central Research Laboratory, Nippon Shokubai Chemical Co., Ltd. Noriko Suzuki (56) References Japanese Patent Publication No. 2-15494 (JP, B2) )

Claims (3)

[Claims] 1. Maleic acid, maleic anhydride, fumaric acid,
One or more unsaturated dicarboxylic acid type monomers (a) selected from the group consisting of itaconic acid and itaconic anhydride, and another monomer (b) copolymerizable with these monomers 10 to 100 mol% of the unsaturated dicarboxylic acid-based monomer (a) and 90 to 0 mol% of the monomer (b) (however, the total of the monomers (a) and (b) is 100 mol%) .) In the carboxyl group-containing polymer (A) derived by using the compound having a carbon number of 2 to
4 alkyleneimine and, if necessary, alkyleneoxide having 2 to 4 carbon atoms in an amount of 0.1 to 10 moles of alkyleneimine added per mole of carboxyl group in the carboxyl group-containing polymer (A). A cement dispersant containing a water-soluble polymer (I) obtained by addition reaction at a ratio. 2. The cement dispersant according to claim 1, wherein the number of moles of alkylene oxide added is within 20 times the number of moles of alkyleneimine added. 3. The water-soluble polymer (I) is one of unsaturated dicarboxylic acid-based monomers (a) selected from the group consisting of maleic acid, maleic anhydride, fumaric acid, itaconic acid and itaconic anhydride. Alternatively, two or more kinds and another monomer (B) copolymerizable with these monomers (B) are unsaturated dicarboxylic acid type monomer (A) 10 to 100 mol% and monomer (B) 90 to 0 mol%
(However, the total amount of the monomers (a) and (b) is 100 mol%.) The carboxyl group-containing polymer (A) derived by using the carboxyl group in the polymer (A) is introduced. 0.1 per mole of base
Aminoalkylated polymer (II) obtained by reacting an alkyleneimine having 2 to 4 carbon atoms in a proportion of ˜10 mol and //
The cement dispersant according to claim 1, which further comprises a polymer (III) obtained by further reacting the polymer (II) with an alkylene oxide having 2 to 4 carbon atoms.