JPS59162165A - Cement dispersant composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cement dispersion composition with low slump loss. More specifically, the present invention relates to a cement dispersion composition that has excellent cement dispersibility, has little slump loss, and does not delay concrete hardening time.

Salts of naphthalene sulfonic acid formalin condensates or salts of melamine sulfonic acid formalin condensates have excellent cement dispersion ability among existing cement dispersants, and are characterized by their ability to greatly reduce this t-mixed concrete cross-contact water. It is used in large quantities in two-shot concrete products that require high strength. However, salts of naphthalene sulfonic acid formalin condensate and salts of melamine sulfonic acid formalin condensate give concrete with excellent fluidity immediately after being mixed with cement, aggregate, water, etc., but after one hour of mixing, The disadvantage is that the fluidity rapidly decreases as the temperature increases. This phenomenon of reduced fluidity is called slump loss, but due to this slump loss, it is difficult to use it for ready-mixed concrete, which requires that no large slump loss occur within 1.5 hours after crosstalk. It has its drawbacks. In order to improve the slump loss, a method was devised to adjust the timing of addition of the salt of naphthalene sulfonic acid formalin condensate, for example, a method in which it was added after the cement was hydrated by contact with water (Japanese Patent Publication No. 51-15856, Japanese Patent Publication No. 58-1982) 5691, Special Publication 58-5692),
Although it has been found to have very satisfactory effects, it has the disadvantage that the addition method is complicated. - It is known that the initial hydration of cement is responsible for the increase in slump loss of concrete made with salts of naphthalene sulfonic acid formalin condensate and melamine sulfonic acid formalin condensates. In order to reduce the slump loss, a cement setting retarder is also used. Various types of setting retarders are known, including organic ones such as genin sulfonic acid, nitrofumic acid and gluconic acid, and inorganic ones such as sodium tripolyphosphate. However, if these retarders are used in combination, the curing time of concrete will be delayed. Demolding of concrete is usually carried out within 1 to 3 days after concrete pouring.
For this reason, early strength (strength after 1 to 3 days) is very important, but it is naturally difficult to increase this early strength when the above-mentioned setting retarder is used in combination. For this reason, it may be possible to use a setting retarder in combination with a setting retarder in the summer when concrete hardens very quickly, but in spring and autumn when concrete hardens not so quickly, it is necessary to increase the demolding time. It has the disadvantage that it is difficult to use and cannot be used at all, especially in the winter when concrete hardens slowly.

Under these circumstances, the present inventors conducted intensive studies on a cement dispersion composition that has excellent cement dispersion ability, does not delay cement hardening, and has little slump loss, and as a result, has arrived at the present invention.

That is, the present invention is a cement dispersion composition characterized by comprising the following two components (A) and [F]).

(a) Salt of naphthalene sulfonic acid formalin condensate and/or salt of melamine sulfonic acid formalin condensate 95
~50 parts by weight Q3) The structural unit represented by the following general formula (1) and the general formula (
Molecule i having a molar ratio of structural units represented by 11) in the range of 9/1 to 1/9 5 to 50 parts by weight of a water-bathable polymer compound of 1000 to 50000 (in the formula, R, , R2 are hydrogen or methyl group, L is -CO
NI (S, A is an alkylene group having 2 to 3 carbon atoms, e, m.

n is a number from 1 to 20, but m10 is a number of 20 or less) General formula (II) 0 In the formula, R3 is hydrogen or methyl group 1M is hydrogen or -CO
OX2 group, R4 is hydrogen, methyl group, -CH2C
A group selected from OOX3 groups, XI, X2. X3 is hydrogen, =(BO)p-R5 represents a certain Iha salt *XI
, X2, X3 is hydrogen or a salt, B is an alkylene group having 2 to 8 carbon atoms, and p is 0 to 2
(the number of 0, Rsl, is hydrogen or an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 7 carbon atoms) In the present invention, the salt of naphthalene sulfonic acid formalin condensation is a salt obtained by condensing naphthalene sulfonic acid with a high degree of formalin condensation. This product is made by neutralizing the same with caustic soda, calcium hydroxide, etc.
, Japanese Patent Publication No. 48-9564, etc. may be used.

Naphthalenesulfonic acids include α-naphthalenesulfonic acid and β-naphthalenesulfonic acid, and β-naphthalenesulfonic acid is preferred. In addition, in the present invention, in addition to the formalin condensate salt of naphthalene sulfonic acid, other aromatic compounds and/or these sulfonic acids may be used as the salt of the formalin condensate of naphthalene sulfonic acid, as long as the performance is not impaired. It also includes co-condensed products. Examples of these are JP-A-51-17219, JP-A-50-
29644, JP-A No. 50-58120, and one other variety. Examples of these are aromatic compounds such as naphthalene and anthracene; aromatic sulfonic acids such as benzenesulfonic acid, anthracene sulfonic acid; toluenesulfonic acid,
Alkyl-substituted aromatic sulfonic acids such as dodecylbenzenesulfonic acid, methylnaphthalenesulfonic acid, ethylnaphthalenesulfonic acid; alkoxy-substituted benzenesulfonic acids such as methoxybenzenesulfonic acid; hydroxy-substituted benzenes such as phenolsulfonic acid.

Examples include alkyl- and alkoxy-substituted benzenesulfonic acids such as ligninsulfonic acid; alkyl- and hydroxy-substituted benzenesulfonic acids such as cresolsulfonic acid. The ratio of these naphthalene sulfonic acids and other aromatic compounds and/or these aromatic sulfonic acids to the extent that they are co-condensed and does not inhibit their performance is generally 3 parts per 100 parts by weight of naphthalene sulfonic acids.
It is 0 parts by weight or less.

In addition, as the salt of the naphthalene sulfonic acid formalin condensate used in the present invention, sodium salt is usually used, but other than this, alkali metal salts such as lithium salts and potassium salts, and calcium salts are also used.

salts of divalent metals, such as magnenium salts, zinc salts, iron salts,
It can also be used as a trivalent metal salt such as an aluminum salt or an iron salt, and can also be used as an ammonium salt, an organic amine salt, an alkanolamine salt, or
It is also possible to use a combination of two or more of these insertion types.

Further, the salt of the melamine sulfonic acid formalin condensate used as component (a) of the present invention is a salt obtained by condensing melamine sulfonic acid with formalin, and may be a commercially available salt. For example, Melment manufactured by Showa Den IC Co., Ltd., NI and -4000° NP-20 manufactured by Hozorisu Bussan fall under this category. The salt of this melamine sulfonic acid formalin condensate is generally melamine and formaldehyde or paraformaldehyde, sulfite (sodium sulfite, ammonium sulfite, sodium bisulfite, ammonium bisulfite, etc.)
and those subjected to an addition reaction in water under alkaline conditions (e.g. pH 9 to 12), those subjected to an addition reaction under alkaline conditions and further condensed under weak acidity (e.g. pH 4 to 6), Further examples include those obtained by addition reaction under alkaline conditions and highly condensing them under strongly acidic conditions (for example, pH 2 to 4). Among these, those that are more preferable than cement dispersibility are those that are highly condensed under strong acidity. Furthermore, among the salts of naphthalene sulfonic acid formalin condensate and the salts of melamine sulfonic acid formalin condensate used as component (3) of the present invention, the salt of naphthalene sulfonic acid formalin condensate is preferable in terms of cement dispersion ability. .

The water-soluble polymer compound which is component 03) of the present invention has a carboxyl group in the side chain as shown in the general formula (If), and also has a group in the side chain as shown in the general formula (1). It is a compound or a salt thereof. Such a polymer compound is usually obtained by copolymerizing a monomer having a carboxyl group at a predetermined ratio by radical polymerization, ionic polymerization, photopolymerization, radiation polymerization, or the like.

In order to make the polymer thus obtained water-soluble, some or all of its carboxyl groups are usually used in the form of a salt. The ionic moieties that form these salts include alkali metal ions such as lithium, sodium, and potassium; alkaline earth metal ions such as calcium and magnesium; trivalent metal ions such as aluminum and iron;
Mention may be made of ions from organic amines such as ammonium, ethanolamine, dimethylamine, triethylamine, triethanolamine.

Examples of monomers having a carboxyl group that provide the structural unit of general formula (II) include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, as well as maleic acid, fumaric acid, ntraconic acid, mesaconic acid,
Unsaturated dicarboxylic acids such as itaconic acid, and these unsaturated dicarboxylic acids with the general formula R5-(OB)pOHC
R5 is hydrogen or an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 7 carbon atoms; B is an alkylene group having 2 to 3 carbon atoms; and p is a number of 0 to 20. Examples include monoesterified products with . At this time, if R5 is a monoester with an alcohol having an alkyl group having 21 or more carbon atoms, or if p exceeds 20, air will be entrained in the concrete.

The drawback is that it is difficult to use. Examples of monomers providing the structural unit represented by the general formula (1) according to the present invention include amides of unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid with H2N (AO) nH. Examples include compounds obtained by adding ethylene oxide or propylene oxide to amide compounds of unsaturated acids and ammonia, or unsaturated amides such as acrylamide, methacrylamide, and crotonamide.

In this case, too, if n or m+e exceeds 20, air will be entrained in the concrete, which will greatly reduce the strength of the concrete, which is not preferable. In component [F]) of the present invention, a structural unit in which R3 and R4 of general formula (11) are hydrogen or a methyl group and M is hydrogen is preferable from the slump loss improvement effect and cement dispersion ability. It is obtained from unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid.

Particularly preferred are unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and monomers that provide a structural unit in which n and (m+g) in the general formula (T) are numbers from 1 to 5. It is a polymer. In the present invention, general formula (1)
It is essential that the molar ratio of the structural unit represented by the formula (1) to the structural unit represented by the general formula (1) be within the range of 9/1 to 1/9. If this ratio exceeds 9/1, not only will the effect of improving slump loss be reduced, but also the curing time of concrete will be slightly delayed, which is undesirable.If this ratio is less than 1/9, there will be almost no effect of improving slump loss, which is undesirable. More preferably, this ratio is within the range of 7/3 to 8/7, as this has the greatest effect on improving slump loss, has excellent cement dispersion ability, and does not delay hardening of cement at all.

In addition, in the present invention, the polymer compound which is the component CB) may be one obtained by copolymerizing the above-mentioned carboxyl group with -CONI ((AO) nH or other unsaturated monomers within a range that does not impair the performance). Examples of these other unsaturated monomers include esters such as acrylic esters and methacrylic esters (usually the number of carbon atoms in the ester moiety is 20 or less), and diesters such as maleic acid and fumaric acid. (diesters with HO-(BO)pR5), vinyl esters such as vinyl acetate and vinyl propionate, vinyl aromatics such as styrene, sulfonic acids such as styrene sulfonic acid and vinyl sulfonic acid, budene, octene, etc. Examples include various olefins.If acrylic esters, methacrylic esters, styrene sulfonic acids, etc. in which the ester group has 4 or less carbon atoms are copolymerized, the cement dispersion ability is rather improved and favorable results can be obtained. The amount of these other unsaturated monomers to be added may vary depending on the type of hydroxyl group or carboxyl group in component CB) or their equivalent ratio.
Usually, it is 30% by weight or less.

Such a water-soluble polymer compound can be obtained according to a method commonly used in industry. For example, radical polymerization is common as a form of reaction, and solution polymerization is preferred at this time. Ketones are used as solvents.As polymerization initiators, benzoyl peroxide, tert peroxide,
- Peroxides such as butyl, azo compounds such as azobisisobutyronitrile, and even persulfates can be selected as appropriate depending on the type of solvent and monomer, and both have a low activation energy for decomposition. Since it is small, polymerization can be initiated under mild conditions. The copolymer thus obtained can be used as a cement dispersant as an acid, but it can also be neutralized with an alkali substance and used as an alkali metal salt, alkaline earth metal salt, ammonium or organic amine salt. . The molecular weight can be adjusted by changing the monomer concentration in the solvent, the reaction temperature, and the reaction time, but those with a molecular weight in the range of 1,000 to 50,000 have particularly good water solubility and exhibit preferable dispersibility in cement. . If the molecular weight is less than 1000, the slump loss will be large, causing a delay in setting. Moreover, when it exceeds 50,000, the water-reducing performance of the naphthalene sulfonic acid formalin condensate salt decreases, and the slump loss also increases. Preferably, the molecular weight is in the range of 3,000 to 80,000. Further, in the composition of the present invention, component (3) must be present in a pure amount of 95 to 50 parts by weight, and component (F) must be in a pure amount of 5 to 50 parts by weight. ■) If the component is less than 5 parts by weight, the effect of improving slump loss will be small;
If it exceeds 50 parts by weight, the hardening of the cement will be slightly delayed and the slump loss will also increase. Preferably (6) component 9
0 to 60 parts by weight, 10 to 40 parts by weight of component CB), more preferably 90 to 70 parts by weight (A), and 10 to 80 parts by weight of (8).

In addition to the above-mentioned component [F], other components (optional components) can be added to the cement dispersion composition of the present invention, if necessary. Such optional components include known air entraining agents such as alkylbensene sulfonates, sulfate ester salts of higher fatty acid alkylene oxide adducts, and Vinzol;
Cement dispersants based on ligninsulfonic acid and polyalkylene gellicol; known cement hardening accelerators such as calcium chloride, sodium chloride, sodium sulfate, soda carbonate, potassium carbonate, sodium thiosulfate, and alkanolamines; ligninsulfonic acid, gluconic acid, Known cement hardening retardants such as citric acid, tartaric acid, and polyphosphoric acid; Known glue agents such as polyvinyl alcohol, starch, methylcellulose, and hydroxymethylcellulose; Known antirust agents such as sodium nitrite and calcium nitrite; and various other agents. can be added.

Cement that can be used for the dispersion composition of the present invention include ordinary Portland cement, early strength Portland cement,
Examples include medium heat Portland cement, alumina cement, fly ash cement, and blast furnace cement.

Among these, the preferred one is ordinary portland cement.

The amount of the dispersion composition of the present invention to be added depends on the use of cement.

Although various changes can be made depending on the required performance, the dispersion composition of the present invention is usually added to cement at a purity of 0.0%.
1 to 5% by weight, preferably 01 to 1% by weight. The content is usually 01 to 05% by weight for ready-mixed concrete, and 0.3 to 1% by weight for two-shot concrete products.

This dispersion composition is usually added when mixing cement and aggregate (sand, crushed stone, etc.) and adding mixing water.
After mixing aggregate and water, it may be added after the cement is hydrated by contact (1 to 2 minutes or more after mixing), or it may be added to cement in advance and then water is added. . Furthermore, a divided addition method may be used in which a part of one dispersion composition is added at the time of crosstalk, and then the remaining dispersion composition is added in one or more divided portions. Furthermore, each component constituting the composition of the present invention may be added separately to cement, aggregate, water, etc. and kneaded, or each component may be added separately at various stages of the cement mortar or concrete mixing process. Since the effects of the present invention can be obtained if the composition of the present invention is produced in the final cement product, it can also be used in such a method.

The method for constructing mortar and concrete containing the dispersion composition of the present invention may be the same as conventional methods, and various methods may be used, such as troweling, spraying, filling into formwork, and injection with a caulking gun. The curing method may be air dry curing, humid air curing, water curing, heating accelerated curing (air secretion curing, automatic rape curing, etc.), or a combination of each may be used.

The dispersion composition of the present invention has excellent cement dispersion ability, and is characterized by not slowing cement hardening and having little slump loss. Taking advantage of this feature, single-dispersion compositions are used in mortar and concrete for roofs, walls, and floors, as well as in waterproof mortar, waterproof concrete, building frames, and molded parts of buildings, especially when the slump loss is low. This mortar is suitable for use in ready-mixed concrete for use in building frames, etc., due to its characteristics, and for producing concrete two-shot products due to its excellent dispersibility.

Suitable as a dispersion composition for concrete.

The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. In addition, all parts in the examples indicate parts by weight based on pure content.

Example 1 (3) Components include 75 parts of sodium salt of naphthalene sulfonic acid formalin condensate (hereinafter abbreviated as NSF), 50 mol% of sodium salt of naphthalene sulfonic acid formalin condensate (hereinafter abbreviated as AAm-EO2) and various monomers having carboxyl groups shown in Table 1. Molecular weight obtained by copolymerizing with 50 mol % of polymer: 5000~! A composition of the present invention was obtained using 25 parts of a sodium salt of a water-soluble polymer compound of 0,000. Using these materials, the following Concrete 1 mixture was prepared, and the slump loss, setting time, and strength of the concrete were measured, and the results shown in Table 1 were obtained. Table 1 also shows % NSF and sodium polyacrylate having only carboxyl groups when NSF is used alone and when NSF and sodium gluconate are used together as an oxycarboxylic acid for comparison with the composition of the present invention.

The results are also shown when a soda salt of a copolymer of 50 mol % of maleic anhydride and 50 mol % of isobutyne is used in combination with a lignin-based commercial water reducing agent (Hozolith N05L, standard type). Table 1 also shows the results obtained when no dispersion composition 5 was used.

In addition, the mix of concrete is 02% C to cement, pure content of the dispersion composition, and the unit cement amount is 320'/m3+
The water/cement water/cement ratio of the 5-segcrete mix has a unit cement amount of 820 kF/m3, a water/cement ratio of 60%, and a fine aggregate ratio of 46%. Further, the concrete temperature is 20°C, and the compressive strength is the value when cured in water at 20°C.

In addition, in Table 1, maleic acid EO1. O.

EO3. O, EO5. o + PO3. O is each 1 mole of maleic anhydride, ethylene glycol, and triethylene glycol.

It is a monoester of maleic acid made from 1 mole each of pentaethylene glycol and tripropylene glycol.

(g) The slump loss amount is the difference between the slump immediately after crosstalk and the slump after 30 minutes, 60 minutes, and 90 minutes.

The larger this value is, the more severe the decline in concrete fluidity is.

As is clear from Table 1, the product of the present invention has significantly improved slump loss compared to NSF alone, and also has a slump loss compared to lignin-based water reducers commonly used in ready-mixed concrete. is decreasing. Furthermore, what is noteworthy about the product of the present invention is not only that the slump loss is reduced, but also that there is no delay in hardening of the concrete. Since the product of the present invention has no curing delay, it sufficiently meets the standards for standard water reducers set by the Architectural Institute of Japan (according to the same standards, compared to the case without a dispersant, both initial and final water reducers are reduced). (The standard type is defined as one that does not cause a delay of 1 hour and 30 minutes without being more than 1 hour earlier.) On the other hand, when sodium gluconate, which is the conventional technology, is used in combination, the slump loss is reduced. The hardening of the concrete is delayed for a long time and the early strength (
(measured by strength after 1 day) did not appear at all, and in practical terms, spring,
It turns out that it cannot be used in autumn and winter.

Example 2 Component (A) was 75 parts of sodium salt of melamine sulfonic acid formalin condensate (hereinafter abbreviated as MSF).

Component (B) is a helium salt 25 of a water-soluble amphimolecular compound with a molecular weight of 5,000 to 10,000 obtained by copolymerizing 250 mol% of AAm EO and 50 mol% of monomers having various carboxyl groups shown in Table 2. A composition of the present invention was obtained using 1.0 parts. Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 2 were obtained. Sho 1
Table 2 also shows the results when MSF was used alone for comparison.

Example 3 25 parts of a sodium salt of a water-soluble polymer compound with a molecular weight of 5,000 to 10,000 obtained by copolymerizing 75 parts of NSF as component (a) and 50 mol% of a monomer that provides an acrylic group as component (ii). The composition of the present invention was obtained using the following method. Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 3 were obtained.

Note that (EO) and (PO) in Table 1 represent an ethylene oxide residue and a propylene Oquindo residue, respectively.

Example 4 A dispersion composition was prepared using 75 parts of N5F as a captive component and 25 parts of a sodium salt of a copolymer with a molecular weight of 5,000 to 10,000 made by changing the copolymerization composition of acrylic acid and AAJTT EO2 as a component [F]. Various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 4 were obtained.

Example D: NSF was used as component (5), sodium salt of a copolymer of 50 mol% acrylic acid and 50 mol% AAm E02 with a molecular weight of 8000 was used as component [F]), component (A) and component (B). A dispersion composition of the present invention was obtained by changing the blending ratio of the following.

Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in the table were obtained.

Example 6 75 parts of N5F was used as component (3), and 25 parts of a sodium salt of a copolymer with a different molecular weight of 50 mol% of acrylic acid and 50 mol% of A'A'm E0 were used as component [F]).
A cement dispersion composition was prepared. Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 6 were obtained.

Claims (1)

[Claims] 16. A dispersion composition for cement with low slump loss, characterized by comprising the following two components (3) and [F]). (a) Salt of naphthalene sulfonic acid formalin condensate and/or salt of melamine sulfonic acid formalin condensate 95
~50 parts by weight CB) The structural unit represented by the following general formula (1) and the general formula (
5 to 50 parts by weight of a water-soluble polymer compound with a molecular weight of 1,000 to 50,000 in which the molar ratio of the structural units represented by II) is within the range of 9/l to 50,000 yen group, n, m, and n are numbers from 1 to 20 , but m+jl
' is a number of 20 or less) COOXI 6 In the formula, R3 is hydrogen or methyl group 1M is hydrogen or -CO
It is an OX2 group, and R4 is hydrogen or a methyl group. -CH2COOX is a group selected from 3 groups, XI, X2
゜X3 is each independently hydrogen, -(BO)pR5 group,
Or it indicates a salt, XI, X2. At least one of X3 is hydrogen or a salt, B is an alkylene group having 2 to 3 carbon atoms, and p is a number of θ to 20. R5 is hydrogen, an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group having 4 to 7 carbon atoms. 2) The dispersion composition according to item 1, wherein the component (8) is a salt of a naphthalene sulfonic acid formalin condensate. 8. Structural unit represented by general formula (1) and general formula (II)
2. The dispersion composition according to item 1 or 2, wherein the molar ratio of the structural units represented by is within the range of 7/3 to 8/7. 4. R3 and R4 in the general formula (If) are hydrogen or a methyl group. The dispersion composition according to any one of Items 1, 2, and 3, wherein M is hydrogen. 5. The dispersion composition according to any one of items 1 to 4, wherein n in formula (1) is a number of 1 to 5, and m+ll is a number of 2 to 5. 6. ([3) The dispersion composition according to any one of Items 1 to 5, wherein the component has a molecular weight of 3,000 to 80,000.