JPS6311557A - Control for entraining air volume of cement mortar or concrete - 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 [Industrial Field of Application] The present invention provides a cement mortar or concrete that provides a high-strength cured product with excellent freeze-thaw resistance, and more specifically, it is used for cement mortar or concrete production. It concerns a method of adjusting the time-travelling landscape.

[Conventional technology]

In recent years, fluidized concrete has attracted attention in the architectural and civil engineering fields for streamlining concrete placement work and improving the quality of poured concrete, and fluidizing agents have come into the spotlight accordingly.

However, naphthalene sulfonic acid formalin condensate salt, which is often used as a fluidizing agent, has a problem in that when applied to fluidized concrete, the consistency changes over time, that is, the so-called slump loss is large. As a method for preventing this slump loss, compounds have been proposed that have both dispersion performance in cement and slump loss prevention performance. For example, JP-A-51-10834, JP-A-5
1-101024, JP 57-118058, JP 58-74552, JP 60-60963,
Various polycarboxylic acid cement dispersants are disclosed in JP-A-60-103062 and other publications.

[Problem that the invention seeks to solve]

However, all of these polycarboxylic acid-based cement dispersants have air entrainment properties in addition to cement dispersion performance and slump loss prevention performance2, which reduces the performance of fluidized concrete that can obtain this air entrainment property. I'm letting you do it. In other words, unlike the so-called AE water reducer, which is used to prepare fresh concrete with a conventional low water reduction rate, fluidized concrete is used to greatly reduce the unit water volume in order to prevent cracking after hardening and increase strength. It is necessary to use a large amount of these polycarboxylic acid-based cement dispersants, resulting in an excessive amount of air entrainment, which causes a problem in that strength decreases after curing.

Antifoaming agents are also used to adjust the amount of air entrained, but in this case the problem is that the air bubbles entrained in cement mortar or concrete become coarser in diameter, reducing freeze-thaw resistance. was there.

In view of the current situation, the present inventors conducted extensive research and arrived at the present invention. Therefore, an object of the present invention is to use a polycarboxylic acid polymer as a high-performance fluidizing agent for addition to a ready-mixed concrete plant or as a cement dispersant for preparing high-strength cement mortar and concrete with few cracks. To provide a method for imparting excellent properties in terms of freeze-thaw resistance and strength to cement mortar and concrete after hardening, by making entrained air bubbles of good quality and adjusting the entrained air bubbles to an appropriate amount. It is in.

[Means and effects for solving the problems] The present invention is based on the general formula (a) (wherein R1 represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, and ! and m each independently represent one or more is a positive integer and satisfies 5≦13+m≦50.) Ethylene oxide derivative (1) of a primary amine represented by (1) and the structural unit represented by the following general formula (b) and general formula (c) A water-soluble polycarboxylic acid polymer (II) containing the represented structural unit as an essential component is prepared in a weight ratio of ethylene oxide derivative of primary amine (I)/water-soluble polycarboxylic acid polymer I11 = O11/100 to 10. /100
This invention relates to a method for adjusting the amount of air entrained in cement mortar or concrete, which is used during mixing of cement mortar or concrete.

(Note) X (However, X represents hydrogen, methyl group or -CH,C00Z, Y represents hydrogen, methyl group or -cooz, Z
represents hydrogen, a -valent metal, a divalent metal, an ammonia group, or an organic amine group other than the ethylene oxide derivative (1) of -#≠#amine represented by the general formula (a).

) word ÷ CH, -C) (c) [[However, R1 represents hydrogen or a methyl group, and human is hydrogen,
Alkyl group having 1 to 23 carbon atoms, Aryl group, alkylaryl group, sulfonated aryl group, -OR'',
-CH,OR', -COOR', -COOsoD-0)-
R' or -CH, -0(-D-0←R4 (R3 is an alkyl group with 1 to 5 carbon atoms!!, D is an alkylene group with 2 to 4 carbon atoms, R4 is hydrogen or 1 carbon number to 5, n is a positive integer from 1 to 100)
Ethylene oxide derivative of primary amine used in the present invention (
1) can be obtained by adding ethylene oxide to a primary amine having an alkyl group or an alkenyl group having 8 to 22 carbon atoms using a conventional method without a catalyst and an alkali catalyst. The number of addition cells (l-)-m) of ethylene oxide to the -class amine is within the range of 5 to 50, and when this number of addition cells is less than 5 moles, the number of addition cells (l-)-m) of the ethylene oxide derivative of the -class amine (11 Water solubility is insufficient and the ability to adjust the amount of entrained air is not fully demonstrated.If it is larger than 50 moles, the water solubility becomes excessive and the primary amine portion per unit weight decreases, resulting in the ability to adjust the amount of air entrained. decreases.

Water-soluble polycarboxylic acid polymer (n
) is a polymer containing as essential components the structural unit represented by the general formula (b) and the structural unit represented by the general formula (-)), such as α-olefin/maleic anhydride copolymer and its Derivatives, styrene/maleic anhydride copolymer and its derivatives, (meth)allyl ether/
Maleic anhydride copolymer and its derivatives, sulfonated styrene/maleic anhydride copolymer and its derivatives,
Sulfonated styrene/(meth)acrylic acid copolymer, (
Meth)acrylic acid ester/(meth)acrylic acid copolymer, (meth)acrylic acid oxyalkyl ester/(meth)acrylic acid copolymer, (meth)acrylic acid polyalkylene glycol monoester/(meth)acrylic acid copolymer Examples include polymers.

In the present invention, the weight ratio of the -grade ethylene oxide derivative +1) and the water-soluble polycarboxylic acid polymer (II) is 0.
．． It is used at a specific ratio of 1/100 to 10/100, but by doing so, it is possible to fluidize the water-soluble polycarboxylic acid polymer (n) without impairing its inherent cement dispersion performance. It is possible to adjust the amount of entrained air when added in large quantities for concrete, etc., and to make the air bubbles entrained in cement mortar and concrete of good quality, ultimately creating a high-quality product with excellent freeze-thaw resistance. Cement mortar and concrete that give strong hardened products can be obtained. In this way, the ethylene oxide derivative (1) of a -grade amine and the water-soluble polycarboxylic acid polymer (n
) in a specific ratio, it is surprising that it is possible to obtain high-quality cement mortar or concrete that entrains an appropriate amount of air bubbles and has high strength.

If the ratio of -m amine ethylene oxide derivative (1)/water-soluble polycarboxylic acid polymer (n) is smaller than 0.1/100, the amount of entrained air may become excessive or bubbles may become coarse. 9, and 1.
If it is larger than 0/100, the action of the -class amine ethylene oxide derivative (1) as an air-entraining agent is expressed, and the water-soluble polycarbonate polymer (n) is used alone. Shows the same or better air entrainment,
Both methods cannot achieve the purpose of the present invention.

In the present invention, an ethylene oxide derivative (1
) and water-soluble polycarboxylic acid polymer (It) may be mixed before preparing cement mortar or concrete, or may be added together with mixing water during mixing, or Each may be added separately at the time of crosstalk. % of primary amine ethylene oxide derivative (1) and water-soluble polycarboxylic acid polymer (It)
When mixing the water-soluble polycarboxylic acid polymer (II) with the ethylene oxide derivative (11), a uniform aqueous solution can be obtained by adding the ethylene oxide derivative (11) to the partially neutralized water-soluble polycarboxylic acid polymer (II), which is desirable in terms of handling.

〔Effect of the invention〕

In the present invention, a specific primary amine ethylene oxide rust conductor (
By using 1) and the water-soluble polycarboxylic acid polymer (It) together in a specific ratio, the cement dispersion performance inherent to the water-soluble polycarboxylic acid polymer (If) is not impaired in any way. When a large amount of this is added to fluidized concrete, etc., the amount of entrained air can be adjusted to an appropriate amount, and the entrained air bubbles can be fine, stable, and of good quality. Therefore, according to the method of the present invention, excellent properties in terms of freeze-thaw resistance and strength can be imparted to cement mortar and concrete after hardening, and the present invention is useful for preparing fluidized concrete in a ready-mixed concrete plant. It can be applied effectively.

〔Example〕

The present invention will be described in detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples, unless otherwise specified, "part" means part by weight and "ch" means percent by weight.

Reference Example 1 390 parts of isopropyl alcohol (hereinafter abbreviated as IPA) was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube, and a reflux condenser, and the inside of the reaction vessel was nitrogen-filled while stirring. The mixture was evaporated and heated to boiling point under a nitrogen atmosphere. Next, methoxypolyethylene glycol monomethacrylate (“NK-ester M-9G” manufactured by Shin Nakamura Chemical ■, average number of added moles of ethylene oxide: 9) 13
3 parts, 27 parts of methacrylic acid, 2 parts of benzoyl peroxide
．． 120 parts of a mixture consisting of 44 parts of IPA and 240 parts of IPA
After the addition was completed, 0.49 parts of benzoyl peroxide dispersed in 10 parts of IPA was added in two portions every 30 minutes. After completing the addition of Nanatsuma, 1
The temperature was maintained at boiling point for 20 minutes to complete the polymerization reaction.

Thereafter, 50 mol of the methacrylic acid used was neutralized with an aqueous sodium hydroxide solution, and IPA was distilled off. Copolymer aqueous solution-I
Post-neutralization was performed so that the ikpH was 7.0, and an aqueous solution of copolymer (1) was obtained. The viscosity of this 40% aqueous solution of copolymer fi+ was as shown in Table 1.

Reference Example 2 354 parts of IPA was charged into the same reaction vessel as in Reference Example 1, the interior of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated to the boiling point in a nitrogen atmosphere. Then hydroxyethyl acrylate 56
parts, 104 parts of acrylic acid, 7. parts of benzoyl peroxide.
A mixture of 7 parts of IPA and 240 parts of IPA was added over 120 minutes, and after the addition was complete, 1.9 parts of benzoyl peroxide dispersed in 37 parts of IPA was added in two portions every 30 minutes. After the monomer addition was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. Thereafter, 50 mol of the acrylic acid used was neutralized with an aqueous sodium hydroxide solution, and IPA was distilled off.

The copolymer (further hydroxylated) is neutralized with an IJum aqueous solution so that the pH of the copolymer aqueous solution becomes 7.0.
An aqueous solution of 2) was obtained. The viscosity of the 40% aqueous solution of copolymer (2) was as shown in Table 1.

Reference Example 3 Into the same reaction vessel as in Reference Example 1, 334 parts of polyethylene glycol monoallyl ether (containing an average of 5 ethylene oxide units per molecule) and 100 parts of water were charged.
The inside of the reaction vessel was replaced with nitrogen while stirring, and the temperature was increased to 95% in a nitrogen atmosphere.
heated to ℃. Thereafter, an aqueous solution of 139.3 parts of maleic acid and 14.2 parts of ammonium persulfate dissolved in 225 parts of water was added over 120 minutes. After the addition was completed, 14.2 parts of a 20% aqueous ammonium persulfate solution was further added over 20 minutes.

After the addition was completed, the temperature in the reaction vessel was maintained at 95° C. for 100 minutes to complete the polymerization reaction fi. Thereafter, the aqueous copolymer solution was neutralized with an aqueous sodium hydroxide solution so that the pH of the aqueous copolymer solution became 7.0, to obtain an aqueous solution of copolymer (3). The viscosity of a 40% aqueous solution of this copolymer (3) was as shown in Table 1.

Reference Example 4 98 parts of maleic anhydride, 6 parts of benzoyl peroxide, and 400 parts of benzene were charged into a No. 11 autoclave equipped with a thermometer protection tube, a stirrer, a gas introduction tube, and a purge tube.
The atmosphere was replaced with nitrogen. Next, the mixture was heated to 70 to 75° C. with stirring, and a polymerization reaction was carried out for 7 hours while introducing 60 parts of butene-1. After that, the precipitated copolymer was separated,
After washing with benzene and drying, 120 parts of the copolymer was neutralized to obtain an aqueous solution of copolymer (4). The viscosity of the 4(l) aqueous solution of this copolymer (4) was as shown in Table 1.

Table 1 Example 1 Ordinary Portland cement (manufactured by Sumitomo Cement ■) was used as the cement, and local river sand for stagnation (specific gravity 2.5) was used as the fine aggregate.
Crushed stone from Takatsuki (specific gravity 2.68) was used as the coarse aggregate and Suita City tap water was used as the water.
, unit water i 170 kg/m" (water/cement ratio 53 cm), unit fine aggregate amount 813 kg/m", unit coarse aggregate amount 979 kg/m" (fine aggregate ratio 47%), and kneaded. Each material was weighed so that the mixing amount was 301, and all the materials were put into a tiltable mixer.

In addition, the copolymer obtained in Reference Example 1 (1
) as a solid content of cement) 0.20%, the average number of moles of ethylene oxide added per molecule of laurylamine is 15
The adduct (hereinafter referred to as laurylamine 8015 mole adduct) obtained by reacting so as to have a molar amount of cement o,
oos% was used. Immediately after adding the materials, they were mixed for 3 minutes to prepare concrete.

The slump, air ht, and compressive strength of the obtained concrete were measured according to Japanese Industrial Standards (JISA 1101, JIS
A 1128, JIS A 1108, JIS A 1
132), and the results are shown in Table 2.

In addition, using the obtained concrete, JISA 62
A freeze-thaw test of concrete was conducted according to the method described in Appendix 82 of 04, and the results are shown in Table 3.

Examples 2 to 7 Copolymer (1) and lauryl amine 7 in Example 1
Concrete was prepared in the same manner as in Example 1, except that the copolymer shown in Table 1 and the laurylamine E015 molar adduct were used in the amounts shown in Table 1 instead of the 8015 molar adduct. .

The slump, air content, and compressive strength of each of the obtained concretes were measured in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 1 All the same operations as in Example 1 were repeated except that the laurylamine E015 molar adduct was not used, and
Prepared concrete.

The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2 Concrete was prepared by repeating the same operations as in Example 1, except that the amount of laurylamine E015 mole adduct used in Example 1 was changed to 4% of cement OO.

The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 3 A concrete was prepared by repeating the same operation as in Example 1, except that instead of the 15 mole adduct of laurylamine EO in Example IK, the average number of moles of ethylene oxide added per molecule of laurylamine was 100 moles.

The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 4 The same operation as in Example 1 was repeated, except that the same amount of antifoaming agent FS Antiform 9° (manufactured by Dow Corning) was used instead of the laurylamine E015 molar adduct in Example 1, and concrete was prepared. was prepared.

The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2.

In addition, using the obtained concrete, a concrete freeze-thaw test was conducted in the same manner as in Example 1,
The results are shown in Table 3.

Table 3 From Table M2 and Table 3, the method for adjusting the amount of entrained air in cement mortar or concrete of the present invention involves frequently using a water-soluble polycarboxylic acid polymer having air entrainment properties as a cement dispersant. It is clear that by setting the amount of air entrained in a suitable amount and making the entrained air bubbles of good quality, excellent properties can be imparted to cement mortar and concrete after hardening.

Claims (1)

[Claims] 1. General formula (A) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (A) (However, R^1 represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, and l and m are each independently a positive integer of 1 or more and satisfy 5≦l+m≦50.) Ethylene oxide derivative of primary amine (I) represented by
and a water-soluble polycarboxylic acid polymer (II) containing the structural unit represented by the following general formula (b) and the structural unit represented by the general formula (c) as essential components, in a weight ratio of an ethylene oxide derivative of a primary amine. (I)/Water-soluble polycarboxylic acid polymer (II) = 0.1/100 to 10/100, the amount of air entrained in cement mortar or concrete is characterized by being used when mixing cement mortar or concrete. Adjustment method. (Note) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (B) (However, X represents hydrogen, methyl group, or -CH_2COOZ, Y represents hydrogen, methyl group, or -COOZ,
Z represents hydrogen, a monovalent metal, a divalent metal, an ammonium group, or an organic amine group other than the ethylene oxide derivative (I) of a primary amine represented by the general formula (A). ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (c) [However, R^2 represents hydrogen or a methyl group, and A represents hydrogen, an alkyl group with 1 to 23 carbon atoms, an aryl group, an alkylaryl group, a sulfone aryl group, -OR^3
, -CH_2OR^3, -COOR^3, -COO-(
D-O)-_nR^4 or -CH_2-O-(D-O)
-_nR^4 (R^3 is an alkyl group with 1 to 5 carbon atoms, D is an alkylene group with 2 to 4 carbon atoms, R^4 is hydrogen or an alkyl group with 1 to 5 carbon atoms, n is 1 ~1
00 (positive integer). ]