JPS5988361A - Concrete foaming agent - 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 concrete foaming agent, and more particularly to a concrete foaming agent that maintains suitable fine air bubbles inside concrete.

To prepare fresh concrete, cement, sand.

Water is used along with pebbles. The strength of concrete structures obtained by curing these materials decreases over time due to environmental effects such as changes in temperature and humidity. In this case, it is known that the reduction in strength due to the action of generating fine air bubbles inside the concrete can be suppressed. Conventionally, such foaming agents for concrete include saponified maleic acid adducts of propylene tetramer and lignin sulfone. acid is known. However, in order to sufficiently prevent a decrease in the strength of concrete, it is generally considered that a bubble ratio (air amount) of about 4 to 5% is suitable, but conventional foaming agents cannot achieve a suitable bubble ratio. I haven't been able to get anything satisfactory yet. In addition, in recent years, there has been a demand for concrete with low viscosity due to the increase in seismic design and the spread of pump construction methods, etc. However, increasing the unit water volume in concrete causes problems such as increased cracking in hardened concrete, so water reduction is required. agent is used. Recently, so-called high-performance water reducing agents, which have even greater water-reducing effects, have been used in combination, but they suffer from rapid slump loss, so additives that maintain fluidity are also desired. .

Therefore, the present inventors have conducted extensive research in order to solve the above-mentioned conventional drawbacks and obtain a concrete foaming agent that can retain suitable microbubbles inside concrete and maintain the fluidity of concrete. The present invention was completed based on the knowledge that a concrete foaming agent made of a saponified product of a reaction product with an acid anhydride can achieve the above object.

That is, the present invention provides a concrete foaming agent comprising a saponified product of a reaction product of polybutene and an unsaturated anhydride.

Here, the polybutene is not particularly limited as long as it is a butene-based polymer, but 1-butene oligomers are particularly preferred. This 1-butene oligomer is obtained by polymerizing 1-butene or copolymerizing i-butene and n-butene from Kosha, and includes a liquid 1-butene oligomer with a number average molecular weight of 10 to 2,500. can. Note that such 1-butene oligomers can be used, for example, for C4 during naphtha decomposition.
The residual liquid obtained by extracting butadiene from the fraction was used as a raw material, and aluminum chloride was used as a catalyst at a temperature of 5 to 150°C.
2-2 can be polymerized at a pressure of 9/iG.

The 1-butene oligomer preferably has substantially 2 to 6 members. Here, the 1-butene oligomer is not limited to dimers, trimers, etc., but may be a mixture of these to some extent, or a mixture thereof, Preferably, the majority consists of a single dimer, trimer, etc.

Note that "substantially" means that there is no problem even if a trace amount of a substance other than 2-6 mer is contained in addition to 2-6 mer.

There are various unsaturated acid anhydrides used in the present invention, but there are no particular limitations, such as maleic anhydride, citraconic anhydride, itaconic anhydride, aconitic anhydride, and the like. In particular, maleic anhydride is preferred since a reaction product with polybutene can be obtained in high yield.

The reaction between an unsaturated acid anhydride and polybutene is usually 200 to
It is carried out at a temperature of 280°C, preferably 210-240°C, for 2-20 hours, preferably 5-10 hours.

By saponifying the reaction product of the unsaturated acid anhydride and 4ζ ribtene thus obtained, the desired concrete foaming agent can be obtained. Saponification may be carried out by a commonly used method, in which the reaction product of the polybutene and the unsaturated acid anhydride is treated with an alkaline hydroxide such as sodium hydroxide or hydroxide. In particular, it can be done. Specifically, the N filtration is based on the reaction product of the polybutene and the unsaturated acid anhydride.
% hydroxide) IJum aqueous solution was added dropwise at room temperature, and the
100°C1 preferably 30~90°C at a temperature of 80~90°C
This can be carried out by holding for 120 minutes, preferably 40 to 60 minutes.

The concrete foaming agent of the present invention thus obtained can be added as a solid or an aqueous solution to a fresh concrete composition consisting of cement, sand, pebbles and water. ``Here, the amount of the concrete foaming agent of the present invention is usually 0 to 100 parts by weight of the above-mentioned fresh concrete composition.
．． The amount is 5 to 10 parts by weight, preferably 2 to 5 parts by weight. If the mixing ratio of the concrete foaming agent is less than 0.5 pores, it is not possible to obtain a concrete hardened body having a suitable foam ratio. Moreover, if 10 parts by weight is added, the fluidity of the ready-mixed concrete composition will decrease, which is not preferable.

In addition, a so-called high-performance concrete water reducing agent may be appropriately added to the above-mentioned fresh concrete composition if necessary. This high-performance concrete water reducer is used to maintain the strength of concrete while maintaining workability in concrete construction by reducing the amount of water mixed in the J ready-mixed concrete composition. . As such a high-performance concrete water reducer, usually 7 talens/l is used.
/ Formalin condensate of phonate is used. The amount of this high-performance concrete water reducer varies depending on various conditions and is difficult to determine unambiguously, but it is generally calculated from LL02 to 100 parts by weight of the above-mentioned fresh concrete composition.
The amount is about 5 parts by weight.

According to the concrete foaming agent of the present invention, the foaming ratio of the obtained concrete hardened body can be made to a suitable value of 4.0 to 4.5%. Therefore, it is possible to sufficiently prevent the strength of concrete from decreasing due to environmental effects. Moreover, since the slump of fresh concrete can be suitably maintained, workability during construction will not be deteriorated.

Therefore, the concrete foaming agent of the present invention is suitable for civil engineering.

It can be widely used in fields such as architecture and in fields that handle secondary concrete products.

Next, the present invention will be explained in detail using examples.

Production Example (1) Production of 1-butene oligomer 51 aluminum chloride was placed in a 5aa glass autoclave, the pressure was reduced with a vacuum pump, and then 50y- of h-butane was added as a solvent. After stirring to fully disperse aluminum chloride, a mixture of 42% isobutine, 18% butene-1 and butene-2, n
-Butane 40%, i,! l) 200i% of the mixture
[Dropped in 1 minute. Then, the mixture was reacted at 120°C for 2 hours.

After the reaction is complete, remove unreacted gas and nibutane,
600 y of water was added under ice cooling to decompose aluminum chloride. Next, after extraction was carried out in 6 times using 500% of n-hexane, the n-hexane was distilled off to obtain an average molecular weight of 20.
A polymer 1001 mainly composed of 0 1-butene was obtained. This polymer was separated by distillation to obtain 2- to 6-position 1-butene oligomers.

(2) Production of reaction product of maleic anhydride and 1-butene oligomer 1 was placed in a SUS 516 autoclave with a predetermined amount of maleic anhydride and substantially 2 of the reaction product obtained in Production Example (1) above. ~Add 6 pieces of 1-butene oligomer, 23
The reaction was allowed to proceed at 0° C. for 5 hours with stirring. After cooling, the contents were transferred to a round bottom flask and the pressure was reduced using a vacuum pump to obtain four types of distillates having predetermined boiling point ranges as reaction products.

The reaction conditions and results are shown in Table 1.

Table 1 (3) Saponification of the above reaction products.
(0% hydroxide) IJum aqueous solution was added dropwise at room temperature,
Hold at °C for 50 minutes.

Next, the pH of each was measured, and 10% hydroxide was added to adjust the pH to 8 to 9.

A part of the aqueous solution prepared in this way was evaporated to dryness and the solid content concentration of the raw aqueous solution was measured, and the solid content concentration of the aqueous solution was 10%.
I added water to make it.

In this way, 10 of the saponified products of the above reaction products 1 to 4
% aqueous solution was obtained.

Examples 1 to 4 A predetermined amount of cement, sand, pebbles, and water were placed in a 100-ton forced stirring concrete mixer and stirred for 2 minutes, then a predetermined foaming agent and water reducing agent were added, and the mixer was further stirred for 60 seconds to produce concrete. A concrete composition was prepared. Table 2 shows the measurement results of these compositions and physical properties. Incidentally, the results of the flow test using J Engineering SR520+ in Example 1 are shown in FIG.

Comparative Example 1 A ready-mixed concrete composition was prepared in the same manner as in Example 1, except that the foaming agent and water-reducing agent were not blended. Table 2 shows the measurement results of these compositions and physical properties.

Comparative Examples 2 and 6 Example 1 except that the foaming agent was changed in Example 1.
A fresh concrete composition was prepared in the same manner as above. Table 2 shows the measurement results of these compositions and physical properties.

Incidentally, the results of a flow test using J Engineering 5R5201 in Comparative Example 6 are shown in FIG.

Comparative Example 4 A ready-mixed concrete composition was prepared in the same manner as in Example 1, except that the foaming agent was changed and the water reducing agent was not added. Table 2 shows the measurement results of these compositions and physical properties.

Formalin condensate of sodium -1β-naphthalenesulfonate 2 A...Saponified product of the above reaction product 10 (0185% electrophoresis added to the weight of cement) B...Saponified product of the above reaction product 2 (cement) C... Saponified product of the above reaction product 6 (added 0. + 85% by weight based on the weight of cement) D... Saponified product of the above reaction product 4 (added 0. + 85% by weight based on the weight of cement) 0. + 85% by weight added to cement) E...Solid 5+10% aqueous solution of saponified product of maleic acid adduct of propylene tetramer (Added Q185% by weight to cement weight) F... Lignosed with lignin sulfone Solid content 10% aqueous solution (α185 heavy weight% illumination added to cement weight) -s According to JIS Allol 14J Engineering 5A1128

[Brief explanation of drawings]

FIG. 1 is a diagram showing the results of a flow test of the concrete foaming agent of the present invention. Patent applicant Idemitsu Petrochemical Co., Ltd.

Claims (4)

[Claims] (1) A concrete foaming agent consisting of a saponified product of the reaction between polybutene and an unsaturated acid anhydride. (2) The foaming agent for concrete according to claim 1, wherein the polybutene is a 1-butene oligomer. (3) The concrete foaming agent according to claim 2, wherein the 1-butene oligomer is substantially a dimer to hexamer. (4) The foaming agent for concrete according to claim 1, wherein the unsaturated acid anhydride is maleic anhydride.