JPS59162160A - 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 dispersion composition for cement that has excellent cement dispersibility, has little slump loss, and does not delay the hardening time of concrete.

Salts of naphthalene sulfonic acid formalin condensates or salts of melamine sulfonic acid formalin condensates have the best cement l-dispersing ability among existing cement dispersants, and can therefore greatly reduce the amount of concrete mixing water. It has the following characteristics and is used in large quantities in two-shot concrete products that require high strength. However, salts of naphthalene sulfonic acid formalin condensates and melamine sulfonic acid formalin condensates do not give concrete with excellent fluidity immediately after being mixed with cement, aggregate, water, etc.; The disadvantage is that the fluidity rapidly decreases as the temperature increases. This phenomenon of decreased fluidity is called slump loss, and due to this slump loss,
．． It has the disadvantage that it is difficult to use in ready-mixed concrete applications where large slump losses must not occur within 5 hours. In order to improve slump loss, a method was devised to adjust the timing of addition of naphthalene sulfonic acid formalin condensate salt, for example, adding it after the cement has been hydrated by contact with water (Tokukosho, 51-15).
856, Special Publication 53-5691, Special Publication 53-569
2) Although satisfactory effects are observed, the method of addition is complicated. On the other hand, it is known that the initial water usage of cement is involved in the increase in slump loss of concrete using salts of naphthalene sulfonate formalin condensate and salts of melamine sulfonate formalin condensate; In order to reduce loss, cement retarders are also used. Various types of setting retarders are known, including organic ones such as ligninsulfonic 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 is poured, and therefore early strength (strength after 1 to 3 days) is very important. Of course, those used together are
This early strength is difficult to increase. For this reason, it is possible to use a 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 difficult to use as it requires more time for demolding. However, it has the disadvantage that it cannot be used at all, especially in the winter when concrete hardens slowly.

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

That is, the present invention provides the following 0. This is a cement dispersion composition characterized by consisting of the two components (2).

(f) Salt of naphthalene sulfonic acid formalin condensate and/or salt of melamizos pphonic acid formalin condensate 9
5 to 50 parts by weight■ Structural unit represented by the following general formula α) and general formula (g)
5 to 50 parts by weight of a water-soluble polymer compound having a molecular weight of 1,000 to 50,000 and having a mo/to ratio of structural units in the range of 9/1 to 1/9 (in the formula, R, , R; is hydrogen or Methyl group, A1 is an alkylene group having 2 to 3 carbon atoms, m1j1-2(X7)53)(
In the formula, R3 is hydrogen or a methyl group, L is hydrogen or -C0
0X2 group di, R4 hydrogen, mef) L/ group, -CH2
A group selected from COOX3 groups, Xl, X2. X3
represents hydrogen, -(A20)tR5 or salt, and X
l, X2. At least one of X3 is hydrogen or a salt, A2 is an alkylene group having 2 to 3 carbon atoms, and t is 0 to 200
R5 is hydrogen or alkyl having 1 to 20 carbon atoms or cycloalkyl having 4 to 7 carbon atoms. In the present invention, the salt of naphthalene sulfonic acid formalin condensation means a product obtained by highly formalin condensation of naphthalene sulfonic acid, whole caustic soda, calcium hydroxide, etc. For example, those mentioned in Japanese Patent Publication No. 41-11737 and Japanese Patent Publication No. 48-9564 may be used. naphthalene sulfonic acid niha-naphthalene sulfonate β-
Naphthalene sulfonic acid is preferred, and β-naphthalene sulfonic 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 and JP-A-50=29.
644, JP-A-50-58120, and many others.

Examples of this include: aromatic compounds such as naphthalene and anthracene; aromatic sulfonic acids such as benzenesulfonic acid, anthracene sulfonic acid; toluenesulfonic acid, dodecylbenzenesulfonic acid, methylnaphthalenesulfonic acid, and ethylnaphthalene. Alkyl-substituted aromatic sulfonic acid such as sulfonic acid; alkoxy-substituted pensense sulfonic acid such as methoxybenzenesulfonic acid; hydroxy-substituted pensense sulfonic acid such as phenolsulfonic acid; alkyl substituted such as ligninsulfonic acid. and alcoquine-substituted pensene sulfonic acid; creso/L/stv 7-acid LD, unaalkyl- and hydroxy-substituted pensense sulfonic acid, and the like. The proportion of these naphthalene sulfonic acids and other aromatic compounds and/or these aromatic sulfonic acids that are co-condensed to an extent that does not inhibit their performance is generally 30 parts by weight or less per 100 parts by weight of naphthalene I lefonic acid. It is. .

In addition, as the salt of the naphthalene sulfonic acid formalin condensate used in the present invention, sodium salts are usually used, but in addition to these, alkaline metal salts such as lithium salts and potassium salts, calcium salts, magnesium salts, zinc salts, etc. salt,
It can also be used as divalent metal salts such as iron salts, trivalent metal salts such as aluminum salts and iron salts, as well as ammonium ta, sulfur amine salts, and alkano-μ amine salts. Also, two or more of these various salts may be used in combination.

Further, the salt of melamine sulfphonic acid formalin condensate used as the prison component of the present invention is a salt obtained by condensing melamine sulfonic acid with formalin, and may be a commercially available salt. Examples of this include Mernant manufactured by Showa Denko K.K., NL-4000 and NP-20 manufactured by Hozorisu Bussan. The salt of this melamine sulfonic acid formalin condensate is generally prepared by mixing melamine and formaldehyde or paraformaldehyde sulfite (sodium sulfite, ammonium sulfite, sodium bisulfite, ammonium bisulfite, etc.) in water under alkaline conditions (for example, pH 9 to 12), those subjected to an addition reaction under alkaline conditions and further condensed under weakly acidic conditions (e.g. pH 4 to 6), and those subjected to an addition reaction under alkaline conditions. Examples include those obtained by condensing to a high degree under strong acidity (for example, pH 2 to 4). Of these,
More preferable than cement dispersibility is one that is highly condensed under strong acidity.

Also, naphthalene y. used as component Q of the present invention.
tv Among the salts of formalin acid condensate and melamine sulfonic acid formalin condensate, the salt of naphthalene sulfonic acid formalin condensate is more preferred than the cement dispersion ability.

The water-soluble polymer compound which is the component (■) of the present invention has the general formula α)
It is a compound or a salt thereof, which has a -COO (AtO to H group) in the side chain as shown in the formula (A), and at least one carboxyl group in the side chain as shown in the general formula (a). Polymer compounds are usually -COO
It is obtained by copolymerizing a monomer having an (A tO )m H group in its side chain and a monomer having at least one carboxyl group in its side chain at a predetermined ratio. In this case, -Coo (A, O
) Examples of monomers having mH are unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid;
They are made by adding ethylene oxide or propylene oxide to glyco/silicone monoesters represented by O(A10) mH or unsaturated monocarboxylic acids under mild conditions (for example, 60 to 80°C). Examples include monoesterified products. Examples of monomers having at least one carboxyl group in the side chain that provide the structural unit of general formula α) include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; Examples include unsaturated dicarboxylic acids such as acid, mesaconic acid, and itaconic acid. In addition, these unsaturated dicarboxylic acids and the general formula R'50-(A20MH (R5 is hydrogen or an alkyl group having 1 to 20 carbon atoms to a cycloalkyl group having 7 carbon atoms, A2 is an alkylene group having 2 to 3 carbon atoms, and tba0 ~ 20).At this time, if R5 has an alkyl group with 21 or more carbon atoms or l exceeds 20, air entrainment becomes high and the strength of concrete is reduced. Not preferred. Component (1) of the present invention can also be obtained by methods other than the above-mentioned method.
) It may be obtained by further adding a predetermined amount of ethylene oxide or propylene oxide to a polymer obtained by copolymerizing a monomer having an mH group and the above-mentioned unsaturated dicarboxylic acids, and esterifying it. Further, after copolymerizing the homopolymer of unsaturated monocarboxylic acids such as the above-mentioned 7-acrylic acid, methacrylic acid/acid, crotonic acid, or the unsaturated monocarboxylic acids with the above-mentioned unsaturated dicarboxylic acid such as maleic acid. , may be obtained by adding ethylene oxide or propylene oxide. 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, magnesium, trivalent metal ions such as aluminum, iron, etc., ammonium, ethanolamine, dimethylamine, trivalent metal ions, etc.
Riechi/Shi Amin, Trieta
Examples include ions from organic amines such as noramine.

Among component (1) of the present invention, m in the general formula (I) is a number of 1 to 5, which is preferable from the slump loss improving effect and cement dispersion ability. Also, 114 of general formula α)
Among the structural units, from the viewpoint of improving slump loss and cement dispersion ability, R2 and R3 are hydrogen or methyl groups, and L is hydrogen, and acrylic acid, methacrylic acid, crotonic acid This is due to

The molar ratio of the structural unit represented by the general formula α) and the structural unit represented by the general formula (A) in component (1) of the present invention is 9/1 to
It is essential that it be within the range of 1/9. This ratio is 9/
If it exceeds 1, the effect of improving slump loss will be reduced, which is undesirable, as it will also slightly slow down the curing of concrete, and if it is less than 1/9, there will be little effect of improving slump loss, which is undesirable. More preferably, this ratio is within the range of 7/3 to 3/7, as this has the greatest effect on improving slump loss, has excellent cement dispersion ability, and does not delay cement hardening at all. In addition, in the present invention, the polymer compound which is the component (■) has the above-mentioned power! Leboxyl group -Coo (A□'lT
Although it contains hH groups in a predetermined proportion, monomers obtained by copolymerizing other unsaturated monomers can also be used as long as the performance is not impaired. Examples of these other unsaturated monomers include esters such as acrylates, methacrylates, etc. a (always, engineering, the number of carbon atoms in the
(diester with HO (A20)t R5), vinyl acetate, vinyl propionate (D vinyl ester), vinyl aromatics such as styrene, sulfonic acids such as styrene sulfonic acid and vinyl sulfonic acid. , butene, octene, and other olefins. Este>If VX is copolymerized with acrylic esters, methacrylic esters, or styrene sulfonic acids having 5 or less carbon atoms, the cement dispersion ability may actually be improved and favorable results may be obtained. The amount of these other unsaturated monomers to be added can be determined according to the method currently used, depending on the type of hydroxyl group or carboxyl group in component (1), or their equivalent ratio. for example,
Radical polymerization is common as a form of reaction, and solution polymerization is preferred at this time, using water, lower alcohols such as methi/7/lefur, ethyl alcohol, and isopropyl alcohol, hydrocarbons such as benzene, and acetone. , methylethylkene are used as solvents.

As a polymerization initiator, peroxide pencil, peroxide te
Peroxides such as rt-butyl, azo compounds such as azobisisobutyronitrile, and even sulfates can be selected depending on the type of solvent and monomer, and all have a low activation energy for decomposition. is small, so polymerization is initiated under mild conditions. The copolymer thus obtained can be used as a cement dispersant as an acid, but it can be neutralized with an alkaline substance and used as an alkali metal salt, an alkaline earth metal salt, or an ammonium or organic amine salt. Can be used. The molecular weight can be adjusted by changing the monomer concentration in the solvent, reaction temperature, and reaction time, but those with a molecular weight in the range of 1000 to 50000 have particularly good water solubility and good dispersibility in cement. It is. If the molecular weight is less than 1000, the slump loss becomes large, causing a delay in setting. Also, 500
If it exceeds 00, the water reducing performance of the salt of the naphthalene sulfonic acid formalin condensate will decrease and the slump loss will increase.

More preferred are those having a molecular weight in the range of 3,000 to 30,000.

The pure ratio of components (6) and f3 of the present invention needs to be 95 to 50 parts by weight for component (F) and 5 to 50 parts by weight for component 0. ■ If the component is 5 parts by weight or less, there is a slump loss. If the amount exceeds 50 parts by weight, the hardening of the cement will be slightly delayed and the slump loss will also increase. Preferably 90 to 60 parts by weight of component (g) and 10 parts by weight of component (f)
~40 parts by weight, more preferably (A) 90-70;01
The amount is 0 to 30 parts by weight.

In addition to the above-mentioned (g) and (ii) components, other components (optional components) may be added to the seven-men 1-dispersion composition of the present invention as required. Such optional components include known air entraining agents such as alkylbenzene sulfone mm, sulfuric ester salts of higher fatty acid alkylene oxide adducts, and Inseal; liquid nitrogen sulfonic acids and polyalkylene glycols; calcium chloride, sodium chloride, sodium sulfate,
Known cement hardening accelerators such as soda carbonate, potassium carbonate, sodium thiosulfate, and alkanolamines; Known cement hardening retarders such as lignin sulfonic acid, gluconic acid, citric acid, tartaric acid, and polyphosphoric acid; polyvinyl alcohol chill cellulose; Various known agents such as hydroxymethylcellulose, known antirust agents such as sodium nitrite, calcium nitrite, etc. can be added.

The cement that can be used for the dispersion composition of the present invention includes W
a portland cement, early strength portland cement,
Examples include moderate heat Portland cement, a/remina 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 added can be varied depending on the use of the cement and the required performance, but usually the dispersion composition of the present invention is preferably added in a pure amount of 0.01 to 5% by weight based on the cement. is 1 to 1%. For ready mix concrete, it is usually α1 to α5% by weight, and for concrete two-shot products, it is usually 0.4 to 1% by weight.

This dispersion composition is usually added when mixing cement and aggregate (sand, crushed stone, etc.) and adding mixing water.
It may be added after kneading the aggregate and water and after the cement is hydrated by contact (1 to 2 minutes or more after kneading), 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 the present dispersion composition is added during kneading, and then the remaining present dispersion composition is added in one or more divided portions. Furthermore, even if each component constituting the composition of the present invention is separately added to cement, aggregate, water, etc. and kneaded, each component can be added separately at various stages of the cement mortar or concrete mixing process. However, as long as the composition of the present invention is produced in the final cement product, the effects of the present invention can be obtained, so such a method can also be used.

Molar concrete containing the dispersion composition of the present invention, concrete 1.
The construction method can be the same as in the conventional case, and various methods can be used, such as troweling, spraying with a single coat, filling the formwork, and pouring with a caulking gun. The curing method may be air dry curing, humid air curing, water curing, heating accelerated curing (steam curing, autoclave curing, etc.), or a combination of each may be used.

The dispersion composition of the present invention has an extremely excellent cement dispersion ability, and also has the features of not slowing down cement hardening and causing little slump loss. Taking advantage of this special feature, this dispersion composition can be used on roofs and walls. , for floor moiretar and concrete; for waterproof mortar, used for molded parts of buildings, etc., and for ready-mixed concrete used for building frames, etc., taking advantage of its low slump loss. Due to its excellent dispersibility, it is suitable as a dispersion composition for mortar and concrete for producing two-shot concrete products.

The present invention will be fully explained below with reference to Examples, but the present invention is not limited thereto. It should be noted that all parts in the examples indicate heavy electric parts based on pure components.

Example 1.

(f) 75 parts of sodium salt of naphthalene sulfonic acid formalin condensate (hereinafter abbreviated as NSF) as an ingredient (f)
As a component, hydroxyethyl methacrylate (hereinafter H
A composition of the present invention was obtained using 25 parts of a sodium salt of a water-soluble polymer compound having a molecular weight of 5,000 to 10,000 obtained by combining 50 mol % of EMA and various carboxyls shown in Table 1. The following concrete compositions were made using these kumquats 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 that for comparison with the composition of the present invention, when NSF was used alone, when NSF and sodium gluconate were used together as oxycarboxylic acid, and when NSF and polyacrylic acid having only carboxyl groups in the molecule were used, NSF was used in combination with the composition of the present invention. Sorter: 50 mol% maleic anhydride and iso1
The results are also shown when 1750 mol% of the copolymer soda salt is used in combination with a lignin-based commercially available water reducing agent (Hozolith NO5L, standard type). Table 1 also shows the results obtained when no dispersion composition was used. The composition of Conc'J-1- is 0.2% dispersion composition (relative to cement, pure content %), and the unit cement amount is 320 kg/rrL.
', the water/cement ratio was 55%, and the fine aggregate ratio was 46%.

The concrete mix when no dispersion composition was used was 14,320 kg of cement per unit β°, 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 Table 1, maleic acid EO, . 0, EO3. . ,
E05. .

PO3. o is a monoester of maleic acid obtained by adding 1 mole each of ethylene glycol, l-'J ethylene glycol, pentaethylene glycol, and tripropylene glycol to 1 mole of maleic anhydride.

(n'?'p 4fa) 0) 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 the case of NSF alone, and also has a slump loss compared to the lignin-based water reducer 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 meets the standard water reducing agent standards set by the Architectural Institute of Japan (According to the same standards, compared to the case where no dispersant is added, the initial (Standard type is defined as one that does not finish more than 1 hour earlier and does not finish more than 1 hour and 30 minutes late.) On the other hand, when using all the sodium gluconate, which is the conventional technology, the slump loss is reduced. The hardening of the concrete is quite delayed and the early strength (measured after one day) has not been achieved at all, meaning that it cannot be used for practical purposes in spring, autumn, or winter.

Example 2 (f) Component 1-lium salt of melamine sulfonate th/remarin condensate (hereinafter abbreviated as MSF) 7
5' part, as component (c), 50 mol% of hydroxyethyl methacrylate and various Cal 7I shown in Table 2 (molecular weight 5 obtained by total copolymerization with 50 mol% of a monomer having a xyl group)
A composition of the present invention was obtained using 25 parts of a sodium salt of a water-soluble polymer compound having an amount of 0.000 to 1.0000. Using these materials, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 2 were obtained. In addition, Table 2 also includes the results when MSF was used alone as a comparison.
vinegar.

Example a 75 parts of N5F as the (f) component, 50 mol% of acrylic acid as the (f) component, and various -COO-(A,O) mH
A composition of the present invention was obtained by using 25% of a sodium salt of a water-soluble polymer compound having a molecular weight of 5,000 to 10,000 obtained by copolymerizing with 50 mol % of a monomer providing a group. Using these, various concrete tests were conducted in the same manner as in Example 1, and the bonds shown in Table 5 were obtained. In addition, acrylic acid E in Table 3
O... , EO3,o etc. are expressed as 1 mole of acrylic acid to 1 mole of diethylene oxide. . Mol, 3. o mol V is added, PO represents propylene oxide, and the same applies to other expressions.

Example 4 (f) 75 parts of N5F as the component, ■ Acrylic as the component
Molecular weight approximately 9 made by changing the copolymerization composition of phosphoric acid and HEMAO
A dispersion composition was prepared using 25 parts of the sodium salt of the oooO copolymer, and various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 4 were obtained.

Example 5 - NSF i was used as the component, sl/'Jum salt of a copolymer of 50 mol% acrylic acid and 50 mol% HEMA with a molecular weight of 8000 was used as the component (2), and the blending ratio of the components (2) and (2) was Instead, a cement dispersion composition was obtained. Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 5 were obtained.

Example G A cement dispersion composition was prepared using 75 parts of NSF as the (f) component and 25 parts of thorium salt of a copolymer of 50 mol% acrylic acid and 50 mol% HEMA with different molecular weights as the (B) component. . Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 6 were obtained.

355-

Claims (1)

[Scope of Claims] 1. A dispersion composition for cement with low slump loss, characterized by comprising the following two components (g) and (f). (c) Salt of naphthalene sulfonic acid formalin condensate or/and salt of melamine sulfonic acid formalin condensate 95 to 50 parts by weight Okibe Structural unit represented by general formula (1) and 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 structural units represented by AI is an alkylene group having 2 to 3 carbon atoms, m4dl~2nd number) General formula Q
I) (wherein R3 is hydrogen or a methyl group, L is hydrogen or -co
ox2 group, R4ta hydrogen, meflV group, -CH
2COOX A group selected from 3 groups "p, x, x2.
X3 each independently represents a hydrogen-(A20)tR5 group or a salt; At least one of X3 is hydrogen or a salt, and A
2 is an alkylene group having 2 to 3 carbon atoms; 2. The dispersion composition according to item 1, wherein component 2 is a salt of a naphthalenesulfonate formalin condensate. (a) The dispersion composition according to item 1 and item 2, wherein the molar ratio of the structural unit represented by general formula α) to the structural unit represented by general formula (IO) is within the range of 7/3 to 3/7. The dispersion composition according to any one of Items 1, 2, and 3, wherein R3 and R4 of the general formula ゛tun@) are hydrogen or a methyl group, and L is hydrogen. 5. The dispersion composition according to any one of the first term, the second term, the third term, and the fourth term, wherein m in formula (I) is a number from 1 to 5. a03) The dispersion composition according to any one of Items 1 to 5, wherein the component has a molecular weight of 3000 to 300oo.