JPS5815057A - Air entraining agent for 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 The present invention relates to an air entraining agent for cement mortar or concrete (hereinafter abbreviated as AE agent).

Cement mortar or concrete for civil engineering and construction work contains an AE agent that entrains the required amount of air during cross-contact, for the purpose of improving workability, reducing precipitate, increasing resistance to freezing and thawing, and reducing the weight of components. It is widely used either alone or in combination with water reducing agents.

AE agents currently in practical use include resinates, higher alcohol sulfate ester salts, higher alcohol ethylene oxide adduct sulfate ester salts, alkyl sulfonates, alkylaryl sulfonates, etc. Of these, resinates are the most commonly used alone as AE agents.

When resinate is used as an AE agent, compared to other agents, the diameter of air bubbles entrained is small, the number of bubbles is large, and the stability of the bubbles is excellent. This is an extremely favorable performance for improving resistance to. However, resin acids are carboxylic acid derivatives, and aqueous solutions of their salts are alkaline, so if they are left in the air as a solution, they will absorb carbon dioxide and some of them will return to free resin acids, becoming cloudy. . In addition, when it comes into contact with alkaline earth metal ions such as calcium ions, magnesium ions, iron ions, or heavy metal ions, water-insoluble salts are immediately produced.
The major drawbacks are the formation of foam as an agent and a decrease in the stabilizing effect. It is partially known that the above-mentioned anionic and nonionic surfactants used as AE agents are used in combination with resin acid soaps, but in order to improve the stability as described above, they are used in large quantities. In that case, the effectiveness of the resin acid soap as an AE agent is reduced.

Recently, as a measure to prevent pollution, there have been many cases in concrete factories where recovered water used for cleaning plants, transport vehicles, etc. is used as is without any treatment as water for mixing concrete. Therefore in this case A
Agent E will be added and dissolved in water with a high concentration of calcium ions.

If the concentration of calcium ions in the water used is high, problems arise, particularly in the solution stability of resinates, as described above.

In view of the current situation, the present inventors conducted intensive research to improve the drawbacks of using the above-mentioned resinates as AE agents, and found that 100 parts by weight of resinates and an amine represented by the following general formula AE containing 50 to 200 parts by weight of derivative
They discovered that by using a resin acid salt, the disadvantages of the resin acid salt as an AE agent could be improved without losing its original performance as an AE agent, and the present invention was completed.

(However, R is an alkyl group or alkenyl group having 8 to 22 carbon atoms, m and n are each an integer of 1 or more, and m+n is 5
~30) The resin acid salt, which is the first component of the present invention, is a salt of gum rosin, wood rosin, tall oil rosin, etc., and potassium or sodium salt is preferable from the viewpoint of water solubility. It can be obtained by heating and saponifying using equimolar amounts of potassium hydroxide or sodium hydroxide and water as a solvent.

The amine derivative, which is the second component of the present invention, can be obtained by adding ethylene oxide to a primary amine having an alkyl group or an alkenyl group in a conventional manner without a catalyst or with an alkali catalyst. If the number of moles of ethylene oxide added to the amine (m1n) is less than 5 moles, the water solubility will be insufficient, and if it exceeds 30 moles, the effect on the stability of the aqueous solution of the resinate will be poor. The usage ratio of the resin acid salt and the amine derivative in the AE agent according to the present invention is 100 parts by weight.
:50 to 200, but if the latter is less than 50, the effect on the stability of the aqueous resinate solution will be insufficient; on the other hand, if the latter is more than 200, the properties of air bubbles entrained in concrete will be impaired. At the same time, it becomes disadvantageous in terms of economic efficiency.

The AE agent according to the present invention can be used alone or with a water reducing agent selected from lignin sulfonates, oxycarboxylate salts, naphthalene sulfonic acid formalin high condensate salts, etc., as long as the air entrainment effect is not lost. There are cases where it is mixed with. The structure of the present invention will be explained in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

・Examples and Comparative Examples Using the AE agents of Examples according to the present invention and the AE agents of Comparative Examples listed in Table 1 below, each of these AE agents was added to a saturated aqueous solution of calcium hydroxide with a resin acid salt. A 1% by weight aqueous solution was prepared, and the aqueous solution was left at room temperature to examine changes in stability over time. Table 1 shows the results.

Table 1 5 mole adduct RiEO2o: ,t L'ylamine ethylene oxide 2
0 mole adduct RIEO2 Nilaurylamine 2 mole adduct of ethylene oxide R11E040: OVylamine 40 mole adduct of ethylene oxide NP15: 15 mole adduct of nonylphenol ethylene oxide *2 - Judgment criteria determined by naked eye: O Transparently dissolved △ Slightly Cloudy but transparent × Cloudy and opaque × × Cloudy and opaque with a large amount of undissolved matter precipitated From the results in Table 1, the examples of the present invention have a higher concentration of calcium hydroxide than the comparative examples when dissolved in a high concentration aqueous solution of calcium hydroxide. It is clear that the solution stability is excellent.

AE agent A of the example according to the present invention described in the following section 1),
B and AE agents C and D of comparative example were adjusted, and each product was AE-treated separately.
Concrete tests were conducted when these AE agents were used as a single AE agent, and when these single AE agents were mixed with the water reducing agent described in 2) below. The materials used and the test methods are as described in the following 3) or 4), Table 2 shows the combinations of these conditions, and Table 3 shows the results.

1) AE agent A A mixture of 100 parts by weight of Nigam rosin potassium salt and 100 parts by weight of 15 moles of laurylamine ethylene oxide adduct (Example) B: 100 parts by weight of wood rosin potassium salt and 20 moles of oleylamine ethylene oxide adduct Mixture with 150 parts by weight of C Nigam rosin potassium salt (Comparative example) D Mixture of 100 parts by weight of Nigam rosin potassium salt with 300 parts by weight of 15 mole adduct of lauryl aminoated ethylene (Comparative example) 2) Water reducing agent E: Calcium lignin sulfonate F Sodium nigerconate G: β-naphthalene sulfonate formalin high condensate sodium salt 3) Materials used: Cement: Ordinary Portland cement manufactured by Onoda Co., Ltd. Specific gravity: 8.17 Fine aggregate: Local river sand for Kinu, Specific gravity: 2.59 Coarse aggregate: Crushed stone from Mt. Hachichi, specific gravity 2.66 Water: 1) Gamagori city tap water 2) Recovered water (supernatant liquid from which sediment was removed with washing water from ready-mixed concrete transport vehicles. Calcilam ion concentration 950 ppm) 4) Test method Concrete mixing: JIS-A1138 slump
:JIS-AIIOI air volume :JI
S-A1128 compressive strength: JIS-A113
2 and 1108 Bubble spacing coefficient: ASTM-C457 Table 2 *1 - Amount used is % by weight of cement Note) Concrete temperature = 20 ± 1°C From the results in Table 3, if the water used is tap water, the present invention Either when the AE agent is used alone or when it is combined with a water reducing agent, the cell spacing coefficient is the same as that of the blank (when the resinate of Comparative Example m1 is used alone), and the resinate has good bubbles. While the properties were not impaired, in the comparative example, the cell spacing coefficient increased and the cell properties of the resinate were degraded.

Furthermore, when the water used is recovered water, the AE agent according to the present invention is not affected by calcium ions either when used alone or when combined with a water reducing agent, as described above, and when the water used is tap water, the AE agent according to the present invention is not affected by calcium ions. Although similar effects were exhibited, the blank (Comparative Example N [using resin acid salt 14 alone) had lower performance and decreased air content. When the water used is recovered water, if the amine derivative is used in excess (Comparative Example N
a5) Compared to the case where tap water is used, there is no significant change in the amount of air, but the bubble spacing coefficient has increased.

As explained above, the present invention includes A containing a predetermined amount of an amine derivative represented by the above general formula with respect to the resin acid salt.
By making it an E agent, the original excellent function of the resin acid salt as an AE agent can be maintained and exhibited to the best extent in accordance with the general usage conditions of AE agents, regardless of whether a water reducing agent is added or not. There is an effect that can be used to

Patent applicant: Takemoto Yushi Co., Ltd. Agent: Hiroshi Yama, Patent Attorney

Claims (1)

[Scope of Claims] An air entraining agent for cement mortar or concrete, containing 50 to 200 parts by weight of an amine derivative represented by the following general formula per 100 parts by weight of a resinate. General formula (where R is an alkyl group or alkenyl group having 8 to 22 carbon atoms, m and n are each an integer of 1 or more, m-4-n
5-30) Contains 50-200 parts by weight of an amine derivative represented by the following general formula per 100 parts by weight of 2-resinate, and further contains lignin sulfonate, oxycarboxylate, and naphthalene sulfonic acid formalin An air-entraining agent for cement mortar or concrete that is appropriately mixed with a water-reducing agent selected from condensate salts. General formula (where R is an alkyl group or alkenyl group having 8 to 22 carbon atoms, m and n are each an integer of 1 or more, and m+n
is 5-30)