JPS63282148A - Cement additive - Google Patents

Abstract

PURPOSE:To provide the titled additive which yields mortar and concrete products having no air bubbles on the surface and having excellent appearance when added in a small amt. to cement by consisting the additive of specific alcohols and urethane compd. CONSTITUTION:The adduct of the ethylene oxide and/or propylene oxide of monohydric alcohol of 1-18C and an isocyanate compd. (example: ethylisocya nate) are brought into urethane reaction, by which the urethane compd. (B) expressed by formula II (R' is alkyl, alkenyl, alkylaryl of 1-18C; (n), (p) are 0-60; (q) is 1, 2; n+p=15-60; part of a residual urethane group may be converted to urethane by alcohols if (q) is <=2; X is a residual urethane converted group of the isocyanate compd.) is obtd. (A) 10-99.5wt.% alcohols expressed by formula I (R is R'; l is 0-20; (m) is 0-60; l+m=0-60) and 90-0.5wt.% component B are then compounded to obtain the cement additive. 0.01-1pt.wt. said additive is added to 100pts. cement.

Description

[Detailed description of the invention] [Industrial application field] The present invention provides cement with a small amount of 11% (o, ox to 1% by weight).
This invention relates to cement additives that can provide mortar and concrete products with excellent surface appearance without bubbles by simply adding them.

[Conventional technology]

Concrete products are indispensable for construction and civil engineering, and their uses are wide-ranging. As is well known, concrete is produced by injecting a cement-containing substance mixed with cement, sand, gravel, water, etc. into a formwork, and then using an internal or external vibrator to remove the cement-containing substance from within the formwork. The method used is to close-pack the material inside the formwork by eliminating voids.

Various concrete admixtures have been researched and developed for the purpose of improving the performance and properties of uncured concrete and the physical properties of hardened concrete, and are in actual use. In particular, the purpose of improving the workability and efficiency of concrete product manufacturing and concrete construction, etc.
Admixtures for the purpose of improving concrete strength and durability after construction, such as AE agents (Air Entralnin)
Typical examples include agents called water reducing agents (dispersing agents) and water reducing agents (dispersing agents).

AE agents improve workability and durability by changing the latent pores (latent air) contained within concrete into tiny independent air bubbles and uniformly distributing (entraining) them in concrete. It is used for the purpose of In addition, water reducers (dispersants) improve the dispersion of cement particles through physicochemical effects such as wetting and permeation, thereby promoting water use and bringing about water reduction effects, and some of them have the same effect as AE agents. Also give.

[Problem that the invention seeks to solve]

For concrete products, especially large secondary products, even if you use our concrete admixtures, the force will not reach the large air bubbles that occur at the interface between the formwork and concrete during construction, and the use of piperators, etc. Despite physical action, large bubbles cannot be completely degassed. Products molded under such conditions will have visible traces of large air bubbles, and the quality and quality of the product will deteriorate. Additionally, modifying these products requires time and expense.

[Specific measures to solve the problem]

The present invention uses two specific compounds in combination,
To provide a cement additive that can improve quality deterioration caused by bubbles in appearance and produce beautiful concrete products without substantially adversely affecting desirable properties of the concrete products.

That is, the present invention provides alcohols RO (CzH40)1(CaHsO)mH·-=Q) represented by the general formula (1) as a prisoner component.
In the formula, R represents an alkyl group, an alkenyl group, or an alkylaryl group having 1 to 18 carbon atoms: J! is 0 or a number less than 20; m is O or a number less than 60: f+m=O~60. ] (8) Component (2) A urethane compound represented by the general formula (If) (R'O(
CzHaO)n(CxHaO)p+,X −=(I[)
[In the formula, R' represents an alkyl group, an alkenyl group, or an alkylaryl group having 1 to 18 carbon atoms; n is ot
or a number below 60, p is 0 or a number below 60, q
represents a number from 1 to 2, and n+p=15 to 60.

In addition, when q is less than 2, a part of the urethanized residue may be urethanized with an alcohol.

X represents a urethanized residue of the incyanate compound. ] The above (conversion) component and (6) component are 10/90 to 99.5
The present invention provides a cement additive compounded in a ratio of 10.5 to 10.5.

Capacity component: Monohydric alcohols having 1 to 18 carbon atoms as the alcohols of component (2) represented by the above formula α); these alcohols are added and polymerized with ethylene oxide and/or propylene oxide. The amount of alcohol obtained is 6.

Examples of monohydric alcohols having 1 to 18 carbon atoms include methanol, ethanol, n-7'a panol, impropanol, n-butanol, imbutanol, hexanol, 2-ethylhexanol, n- -Octatool, decanol, dodecanol, tetradecanol, hexadecanol, octadecanol, oftadecenol,
Alcohol obtained from coconut oil, tallow oil or linden oil, primary alcohol synthesized by the Okin method, primary alcohol synthesized by the Ziegler method, secondary alcohol synthesized by the paraffin oxidation method, and appropriate combinations of these various alcohols. Mixtures of more than one species can be used.

In the adduct of ethylene oxide and/or propylene oxide of -hydric alcohols, a part of these alkylene oxides may be replaced with phytelene oxide.

When alkylene oxide is used in combination, the adduct may be a random copolymer or a block copolymer.

The number of moles of alkylene oxide added is 60 moles or less, preferably 0 to 50 moles. If it exceeds 60 moles, the viscosity will increase, the dispersibility will be poor when blended into cement, and a sufficient antifoaming effect will not be exhibited.

Φ) Component (2) The urethane compound represented by the general formula (II) is obtained by subjecting an incyanate compound to a urethane reaction with an adduct of ethylene oxide and /l or propylene oxide of a monohydric alcohol having 1 to 18 carbon atoms. You can get the excerpt.

A method for producing such a compound is described, for example, in JP-A-57-119.
It is described in Publication No. 807.

Examples of incyanate compounds used to obtain such urethane compounds include ethyl inocyanate, inpropyl inocyanate, n-butyl inocyanate, inbutyl inocyanate, phenylinocyanate, tolylisocyanate, and the like. aliphatic diisocyanates such as monoisocyanate, hexamethylene diisocyanate, etc.), 2.4-) lylene diisocyanate, 2.6-) lylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, 1. 3-phenylene diinocyanate, 1
．． 4-phenylene diisocyanate, isopropylbenzo-2,4-diincyanate, ω,ω' diincanate 1,2-dimethylpenzole, 4゜4'-diphenylmethane diincyanate, diphenyldimethylmethane-4,4 '-Diincyanate, biphenyl-2,4'-diincyanate, biphenyl-4,4'
- aromatic diincyanates, such as diisocyanates,
Benzene-1,2,4-) diisocyanate, toluene-2,4,6-triincyanate, 414'14'-
Examples include incyanate compounds such as triphenylmethane triisocyanate, diphenyl ether-29414'-triincyanate, and polyisocyanate in which about three phenyl incyanates are linked via methylene bridges.

In the practice of the present invention, components (2) and (F) are essential components in order to exhibit surface aesthetic performance, and each alone has no effect.

■The ratio of alcohol as a component and the urethane compound as a component (B) ((A)/[F])] is 10/90 to 9
9.510.5 (weight ratio), preferably 20/80~
It is 99/l. If it is less than 10/90, the air entrainment effect will be too strong and many fine bubbles will be generated on the surface, spoiling the surface beauty. If the ratio exceeds 99.5/0.5, there is no effect of addition at all.

The cement additive of the present invention is used in an amount of 0.01 to 1 part by weight, preferably 0.03 to 0.5 part by weight, per 100 parts by weight of cement. If the amount is less than this range, the effect of improving the surface appearance will be small, and if it is more than this range, the mechanical strength of the concrete product will be reduced, which is not preferable.

Furthermore, if necessary, water reducing agents, accelerators, retarders, etc. may be used in combination.

Water reducing agents include naphthalene sulfonate formalin condensate, melamine resin sulfonate, polycarboxylate, etc., and accelerators include various sulfates such as calcium chloride, sodium aluminate, aluminum sulfate, and sodium sulfate. , various carbonates such as sodium carbonate, etc. Examples of retardants include various oxycarboxylic acid salts such as gluconate, citrate, and tartrate, and various silicates such as sodium silicofluoride.

The hydraulic cement to which the admixture of the present invention is mixed includes:
Ordinary Portland cement, early strength Portland cement, moderate heat Portland cement, sulfate-resistant Portland cement, white Portland cement, blast furnace cement,
Examples include silica cement, fly ash cement, and expansive cement.

Cement usually contains water, fine aggregate, and coarse aggregate.

Water is used in an amount of 30 to 70 parts by weight per 100 parts by weight of cement.

Fine aggregates include river sand, crushed sand, crushed sand, artificial light sand, etc., and these are used for cement 100! In the case of mortar and concrete products, it is used at a ratio of 100 to 300 parts by weight. River gravel and crushed stone are generally used as coarse aggregates, but they are not added when making mortar molded products, but when producing concrete molded products, they are used at a ratio of 200 to 400 parts by weight, and the proportion of fine aggregate is It is generally used at a ratio of 27 to 45% by weight.

Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these Examples.

Synthesis example of cement additives Synthesis example 1 of alcohols (component A) 93f of nilauryl alcohol and 1.86% of sodium hydroxide
f into a stirring autoclave, and the system was filled with N2.
It was preheated to 130° C. while replacing the air.

Then, at this temperature, propylene oxide 14
5? was introduced under a pressure of 2 to 5147 adG to carry out an addition reaction.

Magnesium silicate powder was added to the product for adsorption treatment to remove the catalyst.

The product is lauryl alcohol propylene oxide 5
Rarely with molar adducts.

Synthesis Example 2 of Urethane Compound (Component B) 2 The 2-uryl alcohol of Synthesis Example 1 was added to 2-ethylhexanol 65F,
Synthesis was performed in the same manner as in Synthesis Example 1, except that propylene oxide was changed to a blend of ethylene oxide 440f and propylene oxide 29f.

The product was a random adduct of 20 moles of ethylene oxide and 1 mole of propylene oxide to 2-ethylhexanol.

Next, 106.89 of this random adduct was placed in a four-loaf flask equipped with a stirrer, and DBU (106.89) was added as a catalyst.
,8-diaza-bicyclo(s-<eo)kundecene-
7) 0.05 f of salt was charged and the system was preheated to 70° C. while purging with N2.

At this temperature, 17.4 f of tolylene diisocyanate is
The mixture was gradually added over 0 minutes to react, and stirring was continued for an additional 90 minutes to complete the reaction.

After the reaction was completed, 2.69 g of activated clay was added and adsorption treatment was performed for 30 minutes, followed by filtration to decolorize and remove the catalyst to obtain a urethane compound.

This product was a pale yellow liquid (69), and as a result of analysis by infrared absorption spectrum, it was confirmed that it was a urethane compound of Az, which was a reaction between the random adduct and tolylene diincyanate.

After mixing concrete with the mixture shown in Table 1, the amount of air was measured.

This concrete composition has a diameter of lOe! ! 1, height 20
It was poured into a Japanese cylindrical form, and after curing, the surface appearance was visually evaluated and the compressive strength (after 28 days) was measured. Table the results.
Shown in 2.

Table-1 *) Ordinary Voltland cement evaluation method: 1) Introduced air amount and compressive strength are JIS A1128,
Measured according to JIS A1108.

2) Visual evaluation of the appearance of concrete products.

Evaluation criteria 0 Almost no bubbles are seen.

Δ Some air bubbles are seen.

X Many large and small bubbles are generated.

(Leaving space below) Examples 7 to 12, Comparative Examples 3 to 9 Using the raw materials shown in Table 3, a trap reaction was performed in the same manner as in Synthesis Example 1 and Synthesis Example 2 to obtain a compound of component Q and a compound of component (2). Ta.

Using these compounds and the cement additives shown in Table 3, a concrete composition was prepared by mixing them in the proportions of the coating 1, and hardened concrete products were obtained in the same manner as in Examples 1 to 6.

The evaluation results are shown in Table-3.

The abbreviations in the table are as follows.

EO: Ethylene oxide PO: Propylene oxide Ecotolylene diisocyanate

Claims (1)

[Claims] 1), (A) component: Alcohol RO (C_2H_4O)_l(C_3H_6O)_mH represented by general formula (I)
...(I) [wherein R represents an alkyl group, alkenyl group, or alkylaryl group having 1 to 18 carbon atoms; l is 0 or a number of 20 or less; m is 0 or a number of 60 or less ;l+m=a number from 0 to 60. ] Component (B): Urethane compound represented by general formula (II) [R'O(C_2H_4O)_n(C_3H_6O)_
p]-_qX...(II) [In the formula, R' is a carbon number of 1 to 18
represents an alkyl group, an alkenyl group, or an alkylaryl group; n is 0 or a number of 60 or less, p is 0 or a number of 60 or less, q is a number of 1 to 2, and n+p = 15 to 60. . In addition, when q is less than 2, a part of the urethanized residue may be urethanized with an alcohol. X represents a urethanized residue of the isocyanate compound. ] The above (A) component and (B) component are 10/90 to 99.5
/0.5 cement additive. 2) The cement additive according to claim 1, wherein the component (A) is 2-ethylhexanol.