JPH03290343A - Water reducing agent for cement - Google Patents

Abstract

PURPOSE:To reduce change of fluidity with time, comprising a condensation product prepared by reacting 2,2-bis(4-hydroxyphenyl)propane shown by a general formula, etc., with a sulfite and an aldehyde. CONSTITUTION:This water reducing agent for cement comprises a condensation product prepared by reacting 2,2-bis(4-hydroxyphenyl)propane shown by a general formula, etc., with a sulfite and an aldehyde optionally under an alkali condition. The general formula is shown by formula I [X is group shown by formula II (n is 1-5 integer), O, R1 and R3 are hydrogen or alkyl group; R2 and R4 are alkyl group].

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to cement compositions such as cement paste, mortar, and concrete. This invention relates to a water reducing agent for cement with improved properties and workability.

[Conventional technology]

Cement paste, mortar, concrete, etc. are used in large quantities in civil engineering, construction, etc.

Various water reducing agents are used to improve various physical properties such as improving workability, increasing strength and durability, and reducing cracking resistance, but there is a need for even higher performance water reducing agents for cement. There is.

[Problem to be solved by the invention]

Among these, sulfonated melamine resin salts have a small water-reducing effect and require a large amount to be added.

Polycarboxylate salts, lignin sulfonate salts, and formalin naphthalene sulfonate high condensate salts have a large water-reducing effect; however, in the case of polycarboxylate salts, increasing the amount added may cause a significant setting delay and, in some cases, result in poor curing. becomes.

・Lignosulfonate contains a large amount of air, which may have a negative effect on the physical properties of mortar and concrete.

・Naphthalenesulfonic acid formalin high condensate salt does not cause setting delay and has very low air entrainment, but the fluidity of mortar and concrete decreases significantly over time.

There were problems such as.

[Means to solve the problem]

Therefore, the present inventors have conducted intensive studies on a water reducing agent for cement that has a large water reducing effect, does not cause setting delay, has low air entrainment, and has less deterioration in the fluidity of mortar and concrete over time, and has developed the present invention. It has been reached.

That is, general formula (1) [wherein X represents any one of OOH (where n is an integer from 1 to 5, R,
R3 is each independently hydrogen or an alkyl group, R2, R
4 each independently represents an alkyl group)], a zincate, and an aldehyde are reacted in any order in the presence of an alkali as necessary. The present invention provides a water reducing agent for cement, which contains a condensation product obtained as a dispersant.

The compounds represented by the general formula (1) used in the present invention include 2,2-bis(4-hydroxyphenyl)propane, 4
．． 4'-dihydroxydiphenylmethane, 4.4'
-dihydroxydiphenylsulfone, 4,4'-dihydroxybiphenyl, and 44'-bis(4-hydroxyphenyl)valeric acid are preferably used, and they can also be used in combination.

Sulfites include sodium sulfite, ammonium sulfite, sodium bisulfite, sodium pyrosulfite,
Examples include potassium bisulfite and ammonium bisulfite.

Useful aldehydes include formaldehyde, paraformaldehyde, formaldehyde polymerization and condensation products such as hexamethylenetetramine, acetaldehyde, etc., and formaldehyde and derivatives thereof are particularly preferred.

Moreover, it is preferable to use the following molar ratio.

Compound represented by general formula (1): A sulfite B aldehyde
:CA:B:C=1+3~02
:6-1.2 Furthermore, general formula f1. ) Compound 2
When using more than one species, the above-mentioned ratio may be applied with the total number of moles of the two or more species as the number of moles of the single substance.

Further, the pH of the reaction solution is preferably 7 to 14, and may be adjusted using an alkali if necessary. In that case, examples of the alkali include sodium hydroxide, ammonia and ammonium hydroxide.

A condensate can be obtained by reacting in these proportions under aqueous conditions at normal pressure or elevated pressure at a temperature of 30 to 140°C for usually 1 to 60 hours.

The water reducing agent for cement of the present invention has the following effects.

・High water reduction properties and no delay in setting.

・Air entrainment is small, and the fluidity of mortar and concrete changes less over time.

The water reducing agent for cement of the present invention is used in a proportion of 0.01% to 2.0%, preferably 0.1% to 0.6%, based on the weight of the cement. If the amount is too small, the expected effect will not be obtained, and if it is too large, the cement will be excessively dispersed, causing a separation phenomenon, which is undesirable.

As the cement, ordinary Portland cement, early strength cement, ultra early strength cement, blast furnace cement, medium heat cement, fly ash cement, sulfate resistant cement, etc. are used. It can also be used in combination with other cement additives, such as water reducing agents, air entraining agents, setting retarders, waterproofing agents, swelling agents, silica humes, stone powder, etc.

As described above, the present invention can be obtained by reacting one or more of the compounds represented by the general formula (1) with a sulfite and an aldehyde in an arbitrary order in the presence of an alkali as necessary. This water reducing agent for cement is characterized in that it contains a condensation product as a dispersant;
A condensation product obtained by reacting one or more species with an aldehyde, (1) one or more sulfonated compounds of the general formula (1), and one of the compounds represented by the general formula (1); Alternatively, any of the condensation products obtained by reacting two or more types with aldehydes can also be included as a dispersant.

Sulfonated products of these compounds represented by general formula (1) can be obtained by direct sulfonation using a sulfonating agent such as sulfuric acid or oleum, or by indirect linkage of sulfone groups through a sulfoalkylation reaction, but preferably sulfurous acid It is a sulfonated product obtained by a sulfomethylation reaction with a salt and an aldehyde. Further, the degree of sulfonation is preferably in the following ratio.

Compound represented by general formula (1): sulfone group=1=1
~2 Also, it is preferable to use the following molar ratio.

Sulfonated product of the compound represented by general formula (1): A Compound represented by general formula (1) 2B aldehyde :CA:B:C=1:
4-0:10-1 [Example] Hereinafter, the present invention will be explained in detail with reference to Examples, where parts in the Examples indicate parts by weight.

Synthesis example fl) 2.2-bis(4-hydroxyphenyl)propane 22
8.3 parts (1 mol) and 126.3 parts (1 mol) of sodium sulfite (
1 mol) is added to 826 parts of water. This solid liquid has a temperature of 100
811 parts of 37% formalin (formaldehyde
1 mol) was added dropwise over 1 hour. Next, this solution was heated to 80°C.
After cooling to .degree. C., 1,622 parts of 37% formalin (2 moles of formaldehyde) was added dropwise over 1 hour, and the mixture was reacted at that temperature for 15 hours to obtain an aqueous solution of a dispersant.

Synthesis Example (2) 2503 parts (1 mol) of 4.4'-dihydroxydiphenylsulfone and 1263 parts (1 mol) of sodium sulfite are added to 860 parts of water. This solid-liquid contains 37% at a temperature of 90℃.
Formalin 243.3 parts (formaldehyde 3 moles)
Drop in for 1 hour. This was heated to 100℃ and 10
The reaction was carried out for a period of time to obtain an aqueous solution of the dispersant.

Synthesis example (3) 2002 parts of 4.4'-dihydroxygenylmethane (1
mol) and 157.9 parts (1.25 mol) of sodium sulfite are added to 790 parts of water. To this solid liquid, 2433 parts of 37% formalin (3 moles of formaldehyde) was added dropwise at a temperature of 100° C. over 1 hour.

This was heated to 100°C and reacted for 15 hours to obtain an aqueous solution of a dispersant.

Synthesis Example (4) 2042 parts (1 mol) of 4.4'-dihydroxydiphenyl ether and 101.0 parts (08 mol) of sodium sulfite are added to 780 parts of water. Add 64.9 parts of 37% formalin (0.8 parts of formaldehyde) to this solid liquid at a temperature of 100°C.
mol) dropwise over 1 hour.

Next, after cooling this solution to a temperature of 80°C, 1622 parts of 37% formalin (formaldehyde 2 mol) was added dropwise over 1 hour, and the reaction was allowed to proceed at that temperature for 15 hours to obtain an aqueous solution of a dispersant.

Synthesis Example (5) 126 J parts (1 mol) of sodium sulfite is dissolved in 826 parts of water, and the pH is adjusted to 14 with a 47% aqueous sodium hydroxide solution. 228.3 parts (1 mol) of 2,2-bis(4-hydroxyphenyl)propane was added to this solution, and the temperature was 1
At 00°C, 811 parts of 37% formalin (1 mol of formaldehyde) was added dropwise over 1 hour. After further cooling this solution to a temperature of 80°C, 162.2 parts of 37% formalin (2 moles of formaldehyde) was added dropwise over 1 hour, and the reaction was allowed to proceed at that temperature for 15 hours to obtain an aqueous solution of a dispersant.

Synthesis example (6) Sodium hydrogen sulfite 104. [1 part (1 mol) of water 7
Dissolve in 60 parts and adjust pH with 47% aqueous sodium hydroxide solution.
Adjust to l0. 186.2 parts (1 mol) of 4,4-dihydroxybiphenyl was added to this solution, and the temperature was 100°C.
81.1 parts of 37% formalin (formaldehyde
1 mol) was added dropwise over 1 hour. Furthermore, this solution was heated to 8
After cooling to 0°C, 162.2 parts of 37% formalin (2 moles of formaldehyde) was added dropwise over 1 hour, and at that temperature
The reaction was carried out for 0 hours to obtain an aqueous solution of a dispersant.

Synthesis example (7) 2.2-bis(4-hydroxyphenyl)propane 17
1.2 parts (0.75 mol) and 71.6 parts (0.25 mol) of 4,4-bis(4-hydroxyphenyl)valeric acid.
and 126.3 parts (1 mol) of sodium sulfite in 85 parts of water.
Add to 0 parts. 243.3 parts (3 moles) of 37% formalin are added dropwise to this solid liquid at a temperature of 80° C. over 1 hour. This was heated to 100° C. and reacted for 10 hours to obtain an aqueous solution of a dispersant.

Synthesis example (8) 2.2-bis(4-hydroxyphenyl)propane 11
4.2 parts (0.5 mol) and 125.1 parts (0.5 mol) of 4.4'-dihydroxydiphenylsulfone, and sulfite) l) 126.3 parts (1 mol) of rum and 834 parts of water
Add to section. To this solid liquid, 37% formalin 243.3 (3 mol) was added dropwise at a temperature of 80° C. over 1 hour. This was heated to 90° C. and reacted for an In period to obtain an aqueous solution of a dispersant.

Synthesis example (9) 22-bis(4-hydroxyphenyl)propane 228
．． 3 parts (1 mole) and 1263 parts (1 mole) of sodium sulfite are added to 940 parts of water. To this solid liquid, 81.1 parts of 37% formalin (1 mol of formaldehyde) was added dropwise at a temperature of 90° C. over 1 hour.

This was heated to 100'C and reacted for 3 hours.

Thereafter, 71.6 parts (0.25 mol) of 4,4-bis(4-hydroxyphenyl)valeric acid was added to the reaction mixture, and 37
% formalin (2.5 moles of formaldehyde) was added dropwise over 1 hour. This was reacted for 10 hours to obtain an aqueous solution of a dispersant.

Synthesis example (field 2.2-bis(4-hydroxyphenyl)propane 22
83 parts (1 mol) and 126.3 parts (1 mol) of sodium sulfite
mol) to 940 parts of water. This solid liquid has a temperature of 9G'C.
186.5 parts of 37% formalin (2.3 moles of formaldehyde) was added dropwise over 1 hour. This temperature is 100℃
The temperature was raised to 100%, and the mixture was allowed to react for 8 hours. After this, add 4,4 to this reactant.
'-dihydroxydiphenylsulfone 25.0 parts (01
16.2 parts of 37% formalin (0.2 mole of formaldehyde) was added dropwise over 1 hour. This was reacted for 5 hours to obtain an aqueous solution of a dispersant.

Synthesis example (1υ 2080 parts (2 mol) of sodium hydrogen sulfite to 970 parts of water
pH 12 with 47% aqueous sodium hydroxide solution.
Adjust to. Adding 228.3 parts (1 mol) of 2,2-bis(4-hydroxyphenyl)propane to this solution,
At a temperature of 100°C, 1622 parts of 37% formalin (formaldehyde 2 mol) was added dropwise over 1 hour, and the mixture was allowed to react for 2 hours. Furthermore, 162% of 37% formalin was added to this solution.
2 parts (2 moles of formaldehyde) were added dropwise over 1 hour,
The reaction was carried out for 56 hours to obtain an aqueous solution of a dispersant.

Concrete Test The consistency of concrete to which the water reducing agent of the present invention was added was compared with the consistency of naphthalene sulfonic acid formalin high condensate (Desumi Kokusaku Pulp Sunflow PS) as a comparative example. Changes in sex over time) were compared.

The formulation is shown in Table 1.

Table 1 For concrete, cement, aggregate, and water containing a water reducing agent were mixed in a 1001 portable tilting mixer for 3 minutes, and the slump was measured immediately and 30.60 minutes later. The concrete slump, air amount, and setting time were determined in accordance with JIS. The measurement results are shown in Table 2.

1) C cement: Ordinary Portland cement specific gravity 3
．． 16 W Water: Tap water S Fine aggregate: Shimane river sand Specific gravity 2.59FM, 2.6
0 G Coarse aggregate: Yamaguchi crushed stone, specific gravity 2.71FM, 6. l
16 [Effects of the Invention] The water reducing agent of the present invention can obtain the target slump at a lower addition rate than the water reducing agent of the comparative example (Sunflow-PS), which indicates that it has excellent dispersibility (water reducing ability). It shows.

Further, the change in slump over time shows that the water reducing agent of the present invention shows less decrease in fluidity over time than the water reducing agent of the comparative example (Sunflow PS).

Further, the water reducing agent of the present invention does not cause retardation of setting, and its air entrainment property is equivalent to that of the comparative example (Sunflow PS).

From these results, it is clear that the water reducing agent of the present invention has excellent effects.

Claims (2)

[Claims] (1) General formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, X indicates either ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or O (however, n is from 1 to An integer of 5, R_1
, R_3 are each independently hydrogen or an alkyl group, R_3
2, R4 each independently represents an alkyl group)], a sulfite, and an aldehyde in any order, optionally in the presence of an alkali. A water reducing agent for cement, characterized in that it contains a condensation product obtained by the reaction as a dispersant. (2) The compound represented by general formula 1 is 2,2-bis(4-
The water reducing agent for cement according to claim 1, which is hydroxyphenyl)propane.