JPH0691149A - Dispersant - Google Patents

Abstract

PURPOSE:To provide a dispersant having excellent dispersion stabilizing performance as well as satisfactory dispersing performance, not deteriorating the flowability of a cement compsn. when added to the deterioration compsn. and capable of preventing the deterioration of the flowability with the lapse of time (slump loss). CONSTITUTION:This dispersant is made of a condensation product obtd. by allowing trisphenols and/or their salts to react with aminobenzene-sulfonic acid and/or its salt and formaldehyde.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dispersant, and more particularly to a dispersant suitable for cement, gypsum, calcium carbonate, dyes, water-soluble paints and coal and water slurries.

[0002]

2. Description of the Related Art Dispersants are widely used as dispersants for cement, pigments such as gypsum and calcium carbonate, or for slurry of coal and water, and are used for other purposes such as dyes and water-soluble paints. As it spreads, it has higher and higher dispersibility, and the long-term stability of the dispersed state after use (dispersion stability)
It has been desired to develop a dispersant having excellent properties.

Conventionally, as a dispersant for cement (also referred to as a water reducing agent), a salt of a sulfonated melamine resin, a salt of a polycarboxylic acid, a salt of a naphthalenesulfonic acid formaldehyde condensate, a salt of ligninsulfonic acid and an aromatic aminosulfone. Acid / phenol / formaldehyde condensates are used, but each of them has the following drawbacks.

The salt of the sulfonated melamine resin has a small water-reducing effect, so that the addition amount becomes large, and the polycarboxylic acid has a large water-reducing effect, but an increase in the addition amount causes a delay in setting, and in some cases, hardening of concrete or the like used. Cause a shortage. Although the salt of a naphthalene sulfonic acid formaldehyde condensate has a large water reducing effect, has little settling delay, and has little air entrainment, the fluidity of the cement composition used, which is represented by slump loss, significantly decreases with time.

Although lignin sulfonic acid has a large water reducing effect, it has a bad effect on the properties of mortar and concrete due to the large amount of air mixed therein. Aromatic amino sulfonic acid / phenol / formaldehyde condensates have a large water reducing effect and are highly fluid. However, there is a problem in that the amount of the active ingredient in the condensate is reduced due to the large amount of unreacted monomer remaining during the condensation reaction, and therefore the amount of addition must be increased.

On the other hand, as a dispersant for pigments such as gypsum and calcium carbonate, or for other uses such as dyes and water-soluble paints, a salt of a naphthalene sulfonic acid formaldehyde condensate is generally used. Since it is not so good, there is a drawback that it is necessary to increase the addition amount.

In order to solve the above drawbacks, in recent years,
A cement dispersant comprising an aromatic aminosulfonic acid / bisphenol / formaldehyde condensate has been developed (Japanese Patent Laid-Open Nos. 3-141142 and 3-1879).
No. 60 publication). However, the dispersant described above is different from the dispersant composed of the aromatic aminosulfonic acid / phenol / formaldehyde condensate in that a large amount of unreacted monomer does not remain during the condensation reaction.
There is a drawback that the effect of preventing slump loss is still insufficient.

[0008]

Therefore, the present inventors
As a result of extensive studies to solve the above-mentioned drawbacks, it was found that good results are obtained when a condensate obtained by reacting trisphenols, aminobenzenesulfonic acid and formaldehyde is used as a dispersant. The invention was reached. Therefore, the object of the present invention is not only excellent in dispersion performance but also excellent in dispersion stability performance, without impairing the fluidity when added to a cement composition or the like, and reducing the fluidity over time (slump loss). It is to provide a dispersant which can be prevented.

[0009]

The above objects of the present invention are as follows.
It is achieved by a dispersant comprising a condensate obtained by reacting trisphenol and / or a salt thereof, aminobenzenesulfonic acid and / or a salt thereof, and formaldehyde. The trisphenols or salts thereof used in the present invention are preferably compounds represented by the following chemical formula 2 or salts thereof.

[0010]

[Chemical 2] In the above formula, R ₁ is a hydrogen atom or a lower alkyl group, and R ₂ is a phenylene group which may have a covalent bond or a substituent.

Specific preferred examples of the above-mentioned trisphenols or salts thereof include 4,4 'and
4 ″ -Ethirizine trisphenol, 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,6-dimethylphenol) represented by Chemical formula 4, 4,4 ′ represented by Chemical formula 5, 4 ″ -methylidine trisphenol,
4,4 '-[1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl] ethylidine] bisphenol represented by the formula 4,4'-[(4
-Hydroxyphenyl) methylene] bis (2-methylphenol) and salts thereof.

[0012]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemical 7]

The aminobenzene sulfonic acid or salt thereof used in the present invention is not particularly limited and can be appropriately selected and used from known ones. Specific examples of the above-mentioned aminobenzenesulfonic acid or a salt thereof include 4-aminobenzenesulfonic acid and 2-amino-5-
Mention may be made of methylbenzene sulfonic acid, isomers of these and other compounds having a methyl group and salts thereof.

The formaldehyde used in the present invention is not particularly limited, and an ordinary formaldehyde aqueous solution can be used. As described above, the condensate according to the present invention can be obtained by subjecting trisphenols, aminobenzenesulfonic acid, and formaldehyde to a condensation reaction.

In the above condensation reaction, it is preferable to use an alkali such as sodium hydroxide under aqueous conditions from the viewpoint of promoting the condensation reaction. When the molar ratio of triphenols to aminobenzenesulfonic acid is 0.5: 1.5, the amount of alkali to be added is in the range of 0.9 to 1.4 mol with respect to 1 mol of aminobenzenesulfonic acid. Is preferred. If the amount added is outside this range, the amount of unreacted aminobenzene sulfonic acid increases sharply, and the performance such as dispersibility and dispersion stability when used as a dispersant deteriorates.

The condensate has a weight average molecular weight of 10,000.
It is preferably in the range of up to 50,000, and other than this range has poor dispersibility and dispersion stability. The weight average molecular weight can be easily measured by gel permeation chromatography (GPC).

When the dispersant of the present invention is used in cement, the addition amount is 0.01-2.
It is preferably in the range of 0% by weight, and particularly 0.1 to
It is preferably in the range of 0.6% by weight. If it is 0.01% by weight or less, the dispersing effect is small, and if it is 2.0% by weight or more, the cement composition is excessively dispersed and causes a separation phenomenon.

The cement that can be used is not particularly limited, and known ordinary Portland cement, fast-strength cement, ultra-fast-strength cement, blast furnace cement, moderate heat cement, fly ash cement, sulfate resistant cement, etc. Can be used. When the dispersant of the present invention is used in cement, other additives for cement can be used together. Examples of such a cement additive include a water reducing agent, an air entraining agent, a sustained release agent, a setting retarder, a waterproofing agent, silica fume, stone powder and the like.

In addition to the above-mentioned cement, the dispersant of the present invention is also suitably used for pigments such as gypsum and calcium carbonate, for slurry of coal and water, for dyes and for water-based paints. In this case, the dispersant is added in an appropriate amount. If the addition amount is too small, the dispersion effect is small, and if it is too large, the viscosity of the slurry as an additive increases.

A dispersant comprising a condensate obtained by reacting trisphenol, aminobenzenesulfonic acid and formaldehyde (referred to as trisphenol condensate) of the present invention is an aromatic aminosulfonic acid / bisphenol / formaldehyde condensate ( It is not clear why the dispersion stability of the trisphenol condensate is superior to that of the dispersant composed of bisphenol condensate (Japanese Patent Laid-Open No. 3-187960). Since it has a complicated three-dimensional structure,
It is presumed that it is difficult for the condensate to be easily incorporated into the cement particles, and therefore the adsorbing rate of the condensate to the cement particles becomes small and the dispersibility is maintained.

The three-dimensional structure of the trisphenol condensate is more complicated than that of the bisphenol condensate because the trisphenol to be reacted has one phenol skeleton in the constitutional unit as compared with the bisphenol. Many,
This is because it has a structure branched from a straight chain.

[0022]

INDUSTRIAL APPLICABILITY The dispersant of the present invention not only has excellent dispersion performance and excellent dispersion stability performance, but also impairs fluidity when added to a cement composition or a pigment such as gypsum and calcium carbonate. It is possible to prevent deterioration of fluidity with time (slump loss). Further, the dispersant of the present invention has excellent dispersibility even when used in a coal / water slurry, a dye, a water-soluble paint or the like.

[0023]

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited thereto.
In addition, "part" which shows a compounding quantity shows a weight part.

Example 1. The following substances were charged into a reaction vessel equipped with a stirrer, a reflux device, a formaldehyde aqueous solution dropping device, and a temperature control device. 4,4 ′, 4 ″ -Methylidine trisphenol 0.5 mol: 212.0 parts 4-aminobenzenesulfonic acid 1.50 mol: 259.8 parts Sodium hydroxide 1.60 mol: 64.0 parts Water : 1180 parts The obtained mixed solution was heated to 90 ° C., and 0.5 mol of 3.1 mol of formaldehyde (251.4 parts of 37% by weight aqueous solution) was added.
The solution was added dropwise over a period of time and further reacted at 90 ° C. for 15 hours to obtain the dispersant of the present invention.

Examples 2-6. 4, used in Example 1
4,4 ′, 4 ″ -methylidyne trisphenol used in Example 1 was replaced with 4 ′, 4 ″ -methylidyne trisphenol and 4-aminobenzenesulfonic acid, respectively. The dispersant of the present invention was obtained in exactly the same manner as in Example 1 except that the mol numbers of phenol, 4-aminobenzenesulfonic acid and sodium hydroxide were changed to the mol numbers shown in Table 1.

[0026]

[Table 1]

Comparative Examples 1-3. 4, used in Example 1
The substances shown in Table 2 were used instead of 4 ′, 4 ″ -methylidyne trisphenol, respectively.
The same procedure as in Example 1 was repeated except that the mole numbers of 4 ′, 4 ″ -methylidinetrisphenol, 4-aminobenzenesulfonic acid, formaldehyde and sodium hydroxide were changed to the mole numbers shown in Table 2. To obtain a dispersant.

[0028]

[Table 2]

Concrete Test Using the dispersants obtained in Examples 1 to 6 and Comparative Examples 1 to 3, concrete tests were conducted as follows. Cement, lubricant and water, and the amount of the dispersant shown in Table 4 were added to a 100 liter inclinable mixer according to the mixing ratio shown in Table 3 below, and kneaded for 3 minutes to obtain concrete. Air content of the obtained concrete and immediately after kneading, 6
The slump loss after 0 minutes and 120 minutes was measured according to JIS, respectively, and the consistency of each concrete and the slump loss were compared. The results are as shown in Table 4.

[0030]

[Table 3]

[0031]

[Table 4]

Gypsum Dispersion Test The dispersant of the present invention obtained in Example 2 and a conventional dispersant consisting of a high-condensation product of naphthalenesulfonic acid formaldehyde were separately added to separately prepared gypsum slurries to disperse the slurries. A sex test was conducted as follows to compare the dispersion performance. The result is as shown in FIG.

Test Method To an aqueous solution prepared by adding a dispersant to 192 g of water, 300 g of hemihydrate gypsum was gradually added over 1 minute, and then the mixture was stirred 100 times for 1 minute using a stir bar to obtain gypsum. A slurry was obtained. The viscosity of the obtained slurry at 30 ° C. was measured using a B-type stirring viscometer, and this viscosity was used as an index of dispersion performance.
The above test, the amount of dispersant added to gypsum 0.2
Repeatedly changing the amount to 5, 0.5, 1.0, 1.5 and 2.0% by weight.

Calcium Carbonate Dispersion Test The dispersant of the present invention obtained in Example 2 and a conventional dispersant consisting of a high-condensation product of naphthalene sulfonic acid formaldehyde were separately added to separately prepared calcium carbonate slurries to obtain the slurry. The dispersibility test was conducted as follows, and the dispersion performances were compared. The result is as shown in FIG.

Test Method Except that calcium carbonate was used instead of gypsum, the same test method as the above-mentioned gypsum dispersion test was carried out. The above results demonstrate that the dispersant of the present invention is excellent in dispersion performance because it reduces the slurry viscosity with a small addition amount.

[Brief description of drawings]

FIG. 1 is a result diagram of a gypsum dispersion test.

FIG. 2 is a result diagram of a calcium carbonate dispersion test.

Claims (3)

[Claims] 1. A dispersant comprising a condensate obtained by reacting trisphenol and / or its salt, aminobenzenesulfonic acid and / or its salt, and formaldehyde. 2. The dispersant according to claim 1, wherein the trisphenol is a compound represented by the following chemical formula 1. In the formula 1, R ₁ is a hydrogen atom or a lower alkyl group, and R ₂ is a phenylene group which may have a covalent bond or a substituent. 3. Trisphenols are 4,4 ′, 4 ″
-Ethirizine trisphenol, 4,4 '-[(4-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4', 4 "-methylidine trisphenol, 4,4 '-[ 1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl] ethylidine] bisphenol and 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2-methylphenol) The dispersant according to claim 1, which is one or more compounds selected from the above.