JP2900261B2 - Hydraulic lightweight composition and method for producing hydraulic lightweight molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a hydraulic light-weight composition and a method for producing the same, and provides a hydraulic light-weight composition in which foamed polystyrene particles are evenly distributed and strength and other characteristics are stable. Another object of the present invention is to provide a manufacturing method capable of obtaining a relatively simple and accurate product.

(Industrial application field) Hydraulic lightweight composition containing various types of expanded polystyrene for civil engineering and construction and containing air bubbles stably and uniformly and having a specific gravity of about 0.3 to 1.8, and a production technique therefor.

(Prior art) Lightweight structural members using inorganic hydraulic materials such as cement have been widely used in the field of civil engineering and construction. Demand is increasing because of structural advantages.

That is, air bubbles are formed by using a foaming agent, or air bubbles are formed by a vaporized gas due to a chemical reaction. Lightweight analogues are often used, the latter of which is typically silicate-lime-based autoclave cultures (ALCs).

Formation and mixing of bubbles include a method in which a foaming agent is mixed with kneading water and the foaming is involved at the time of stirring, and a method in which a liquid containing the foaming agent is foamed through a foaming machine and kneaded.

(Problems to be Solved by the Invention) In any of the conventional foam forming and mixing techniques as described above, the bubble film is unstable in any case, and is easily lost even when it is poured into a mold. Insufficient strength. Furthermore, the quality of the lightweight aggregate also varies greatly, and it is difficult to obtain a composition having stable strength and weight. Further, since the absorbability is high, the amount of kneading water used increases, and the strength of the cured product decreases.

On the other hand, those that have reduced the weight by forming bubbles by chemical reaction,
In general, the chemical reaction is often continued even after molding, which makes it difficult to obtain a composition in a predetermined form and has a large variation in quality. In particular, in ALC, the cells become open cells, the water absorption is increased, the freeze-thaw resistance is inferior, and since the alkalinity is lost, it is necessary to perform a rust preventive treatment on a reinforcing bar or the like. Of course, the equipment for autoclave curing must be large and complicated.

In addition, expanded polystyrene is widely used today as a packing material or heat insulating material, and unlike the above-mentioned porous aggregate, it has almost no water absorption and is an excellent lightweight material with little variation in quality. If the material is mixed into the kneaded material as a hydraulic lightweight composition as described above, aggregate separation occurs due to a difference in specific gravity, and a product having a stable and uniform distribution cannot be obtained. It is also conceivable that the hydraulic material kneaded material containing the expanded polystyrene is autoclaved and the expanded polystyrene is melted to form a structural material having voids covered with a polystyrene coating. Therefore, it is difficult to use it stably.

"Structure of the Invention" (Means for Solving the Problems) The present invention has been made through repeated studies to solve the problems of the above-described conventional devices, and is as follows.

1. (A): Expanded polystyrene, (B): Air bubbles composed of an aqueous resin having a film-forming ability obtained by combining a foaming agent, a water-soluble resin and a water-dispersible resin, (C): Hydraulic substance composed of cement , As an essential component, the component (A) is 5 to 55% by volume,
A hydraulic lightweight composition comprising the component (B) in an amount of 10 to 47%, the balance being the component (C), and the specific gravity being 0.3 to 1.8.

2. (A): expanded polystyrene, (B): air bubbles made of an aqueous resin having a film-forming ability obtained by combining a foaming agent, a water-soluble resin and a water-dispersible resin, (C): a hydraulic substance made of cement (D): One or both of sand, gravel and other aggregates and additives are essential components, and the component (A) is 5 to 55% by volume,
A hydraulic lightweight composition comprising the component (B) in an amount of 10 to 47%, the balance being the component (C), and the specific gravity being 0.3 to 1.8.

3. (A): foamed polystyrene, (B): foam composed of a foaming agent and a water-based resin having a film-forming ability, (C): hydraulic material composed of cement, and in a kneaded product of component (C). A method for producing a hydraulically lightweight molded body, comprising: adding and kneading the component (B) to the mixture; and then molding and curing the mixture obtained by adding and kneading the component (A).

4. (A): Expanded polystyrene, (B): Bubble composed of foaming agent and water-based resin having film forming ability, (C): Hydraulic substance composed of cement, (D): Sand, gravel and other aggregate Using either one or both of the additives and the additives, the component (B) is added and kneaded to the kneaded product of the component (C), and then the component (A) and the component (D) are kneaded, and then molded and cured. A method for producing a hydraulic lightweight molded article, characterized in that:

(Operation) The components (A) and (B) reduce the weight and impart water absorption and water resistance. In addition, the component (B) prevents the component (A) from being separated from the kneaded material, thereby obtaining a stable product. Further, the component (C) imparts properties as a hydraulic composition.

By making the component (A) 5% or more and the component (B) 10% or more, the above-mentioned weight reduction is appropriately brought about, and (A)
By setting the component to 55% or less and the component (B) to 47% or less, effective strength can be obtained.

The strength is maintained by setting the specific gravity of the molded body to 0.3 or more, and the lightness is obtained by setting the specific gravity to 1.8 or less.

The component (B) is added to the component (C) and the mixture is kneaded with the component (A).
The components are added and kneaded to prevent separation of the component (A) in the kneaded product, and to obtain a composition of stable quality with no variation.

(Examples) To further explain the details according to the present invention as described above, as the expanded polystyrene of (A) used in the present invention, almost all commercially available polystyrene can be used. It is. The form may be foamed in advance in accordance with the use conditions, or bead-like foam containing a foaming component may be heated and foamed at a molding site and cured. Further, it is usually spherical, but it is possible to use foamed polystyrene scrap recycled or irregular foam. The expansion ratio is 5 to 60 times (true specific gravity of about 0.02 to 0.2). If it is less than 5 times, the effect of weight reduction is poor, and it is not preferable in terms of economy, and if it exceeds 60 times, it is kneaded. It is not preferable because it is easily crushed and deformed. Its size should be selected according to the scale of the molded body, etc. and is not particularly specified, but industrially, a spherical shape having a diameter of about 0.5 to 20 mm is easily obtained,
Those with a diameter of 1 mm to 5 mm are easy to knead. As for the amount of use, it is preferable to use 5 to 55% by volume in the molded body. If it is less than 5%, the effect of weight reduction is small, and if it exceeds 55%, the strength of the molded body is significantly reduced. Tend to.
More preferably, use of 10 to 30% is preferable from the viewpoint of weight reduction and strength.

The foam composed of the foaming agent (B) and the water-based resin having film-forming ability has the following components. That is, a foaming liquid comprising three components of (a) a foaming agent, (b) a water-based resin having a film-forming ability, and (c) water is formed into bubbles by a foaming machine. The foaming agent is an essential component for lowering the surface tension of the foaming liquid and foaming, but almost all commercially available foaming agents can be used. Specifically, for example, alkyl sulfate, alkyl allyl sulfonic acid, sodium such as alkyl allyl polyether sulfate,
Potassium and ammonium salts, so-called anionic emulsifiers,
Examples thereof include nonionic emulsifiers such as resin acid soap, polyoxyethylene alkyl ether, and polyoxyethylene alkyl phenol ether, which are used as one kind or as a mixture of two or more kinds. The amount used is preferably 3 to 15% by weight in terms of the solid amount ratio in the foaming liquid. That is, if the amount is less than 3% by weight, the foaming effect of the composition is not sufficient, and even if the amount exceeds 15% by weight, the water resistance and water absorption of the obtained cement molded product are undesirably deteriorated. Preferably 3
~ 10% by weight.

The water-based resin having the film-forming ability of the above (b) is for stabilizing the bubbles foamed by the foaming agent, and further, the bubbles are mixed into an inorganic compound such as cement paste and hardened to form a molded article. When this occurs, moisture is absorbed and diffused into the cured cement in the cell membrane, and at the same time, the aqueous resin is concentrated on the cell walls to form a film, which contributes to the improvement of the physical strength, water resistance and the like of the cured molded article. As a form, any of a water-soluble form and a water-dispersible form can be adopted.

To be specific, synthetic resins include acrylic resin, acrylic styrene resin, vinyl acetate resin, styrene butadiene rubber (SBR), urethane resin, alkyd resin, oil-free alkyd resin, polyamide, melamine resin,
There are water-soluble resins and water-dispersible resins such as polyvinyl alcohol, rosin maleate, and modified types of these resins. Examples of natural products and resins obtained by subjecting natural products to denaturation or chemical treatment include casein, denatured den powder, modified cellulose such as methylcellulose and hydroxyethylcellulose, and gum arabic. One of these resins or Although two or more types can be used, when the resin is roughly classified into an anionic type, a cationic type, and a nonionic type depending on the charge state, the combined use of the anionic type and the cationic type may cause aggregation of the resin. Requires great care. The aqueous resin having a film forming ability becomes a stable composition by being composed of a combination of a water-soluble resin and a water-dispersible resin. This means that the water-soluble resin mainly prevents the diffusion of water in the bubbles by the water retention and the viscousness of the resin,
The water-dispersible resin contributes to the stabilization of air bubbles, and the water-dispersible resin forms a water-resistant resin film when the cement molding is dried and hardened together with the stabilization of the air bubbles. It is presumed that they function complementarily to each other.

The selection and use amount of the water-based resin, and the ratio of the water-soluble resin to the water-dispersible resin can be variously selected, but should be adjusted within a range that does not adversely affect the economy, the ease of handling, and the hardening of the cement. It is. The amount used is preferably 97 to 85% by weight in terms of the solid content ratio in the foaming liquid. The ratio of the water-soluble resin to the water-dispersible resin is particularly preferably 90/10 to 60/40 (solid fraction ratio).

The solid content concentration of the foaming liquid is preferably 1 to 10% from the viewpoint of easiness of handling and economy, and if it is less than 1%, the bubble stabilizing effect is small.

The expansion ratio (cell volume / liquid volume) of the above foaming liquid is preferably in the range of 10 to 35 times from the ease of foaming by a foaming machine,
Further, considering the stabilization and strength of the foam, it is appropriate to make the foam about 10 to 25 times. The amount of air bubbles used is preferably 10 to 47% by volume in the molded body, and if it is less than 10%, the effect of weight reduction and the effect of reducing aggregate separation of expanded polystyrene described below are small, and if it exceeds 47%. The strength of the molded body is liable to decrease significantly. Further, a use amount of 10 to 30% is desirable. In any case, such bubbles of the present invention are bubbles themselves,
Also, they are stably present even when kneaded and dispersed in mortar or the like.

Next, as the hydraulic cement of (C), one or more kinds of mixtures of alumina cement, white Portland cement, ordinary Portland cement, early-strength Portland cement, various mixed cements, and the like can be used.
Preferably, it is ordinary Portland cement.

Aggregates used as necessary in (C) include ordinary aggregates such as sand and gravel, as well as pumice, flint, anti-firestone, and ALC.
Light aggregate such as waste, perlite, asbestos, carbon fiber,
Examples thereof include polyvinyl alcohol fiber, polypropylene fiber, nylon fiber, glass fiber, steel fiber, and the like, and one or a mixture of two or more thereof is used.

Other organic and inorganic admixtures (materials) other than the components (A), (B) and (C) described above can be used without departing from the characteristics of the present invention. For example, known and commonly used water reducing agents such as melamine sulfonic acid, naphthalene sulfonic acid, and polycarboxylic acid, polyoxyalkylene glycol-based, polycarboxylic acid-based thickener, water-retaining agent, gluconic acid, and oxycarboxylic acid-based curing Shrinkage modifiers such as retarders, fly ash and Denka CSA (manufactured by Denki Kagaku)
Examples thereof include a foaming agent such as aluminum powder, a hardening agent such as an alkali metal carbonate, and slaked lime. These admixtures (materials) can be appropriately added depending on the application.

The production sequence of the product according to the present invention is generally such that components (A) and (B) are sequentially mixed and dispersed in a mortar or the like prepared from component (C) with a mortar mixer in advance, homogenized, molded, and cured. I do. The mold filling may be made at the construction site, and the casting may be performed as it is, or it may be poured into the molded product formwork in the factory. There is no particular limitation on the shape of the mold as long as it can be performed by normal mold filling work. However, excessive use of a vibrator at the time of mold packing is not preferable because aggregate separation easily occurs.

Curing does not hinder the same curing method as ordinary concrete. That is, various curing methods such as standard curing, steam curing, carbon dioxide curing, and autoclave curing can be used. In the autoclave curing, the expanded polystyrene is melted, and the voids occupied by the foamed polystyrene in the molded state (before melting). Since the melted polystyrene is formed into a film and adheres to the wall surface, there is no decrease in physical properties such as large strength, and even in this case, it can be manufactured stably.

As described above, according to the present invention, a cured product having a wide specific gravity,
It is obtained with almost no limitation on the molding method and the curing method, and can be applied to a wide range of uses as a lightweight member for a structure for civil engineering and construction. The composition according to the present invention contains foamed polystyrene and air bubbles stably and exhibits excellent physical properties. The mechanism is based on the fact that the composition (B) of the present invention contains an aqueous resin having a film-forming ability. The foamed bubbles are different from those of the usual foaming agent alone, and are stably present in the cement compound and viscous, so the aggregate separation resistance of the expanded polystyrene significantly increases, and a cured product of uniform composition is obtained. In addition, even after curing, the bubbles remain as closed cells, and the cell walls are covered with a film-forming resin film, which in combination with the low water absorption of expanded polystyrene provides excellent water absorption and freeze-thaw resistance. , Bending, compression and the like.

The following table shows some examples of specific production examples according to the present invention. No. 1 is excessively foamed by the foaming agent (B) and the aqueous resin, and No. 6 The foaming by the foaming agent and the water-based resin as the component (B) is very small, and the foaming polystyrene as the component (A) is excessive in No. 12, all of which are comparative examples. It is a production example of the present invention that satisfies the requirements of the invention.

"Effects of the Invention" When the present invention as described above is used, a lightweight and stable polystyrene can be effectively and uniformly contained in the hydraulic composition to obtain a preferable stable lightweight body, and is used for this purpose. By foaming with a foaming agent and a water-based resin having a film-forming ability, it is also possible to provide an effective lightweight composition by reducing the weight and improving the strength and water resistance, and the production thereof is relatively easy. Since the invention is easy and is less subject to restrictions such as a molding method and a curing method, and can appropriately obtain a product applicable to a wide range of uses, the invention is industrially highly effective.

Continued on the front page (72) Inventor Tetsuo Yamada 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Yoshitaka Ito 4-8-13 Kokubunjidai, Ebina-shi, Kanagawa Prefecture (72 ) Inventor Tokio Goto 2-82-2 Chiyoda, Takaishi City, Osaka Prefecture 205 (72) Inventor Koichi Yamaguchi 3-3-1 3-Higashisukematsu-cho, Izumiotsu City, Osaka Prefecture (72) Inventor Zengo Ninomiya Shingo Kanaoka, Sakai City, Osaka Prefecture 3-4-1, Machi (56) References JP-A-62-187184 (JP, A) JP-A-56-155062 (JP, A) (58) Fields studied (Int. Cl. ⁶ , DB name) C08J 9 / 22,9 / 228,9 / 30 C08L 25/06 C04B 38/10

Claims (4)

(57) [Claims] (A): foamed polystyrene; (B): air bubbles made of an aqueous resin having a film forming ability obtained by combining a foaming agent, a water-soluble resin and a water-dispersible resin; (C): cement. A hydraulic substance, as an essential component, the component (A) is 5 to 55% by volume,
A hydraulic lightweight composition comprising the component (B) in an amount of 10 to 47%, the balance being the component (C), and the specific gravity being 0.3 to 1.8. (A): expanded polystyrene; (B): air bubbles made of an aqueous resin having a film-forming ability obtained by combining a foaming agent, a water-soluble resin and a water-dispersible resin; and (C): cement. A hydraulic substance, (D): one or both of sand, gravel and other aggregates and additives are essential components, and the component (A) is 5 to 55% by volume,
A hydraulic lightweight composition comprising the component (B) in an amount of 10 to 47%, the balance being the component (C), and the specific gravity being 0.3 to 1.8. (A): expanded polystyrene, (B): foam made of a foaming agent and an aqueous resin having a film-forming ability, (C): hydraulic material made of cement, and A process for producing a hydraulically lightweight molded article, comprising adding and kneading the component (B) to the kneaded material, and then molding and curing the kneaded product to which the component (A) is added and kneaded. (A): expanded polystyrene; (B): foam composed of a foaming agent and an aqueous resin having a film-forming ability; (C): hydraulic material composed of cement; (D): sand, gravel, etc. Using one or both of the aggregate and the additive, the component (B) is added and kneaded in the kneaded product of the component (C), and then the component (A) and the component (D) are kneaded. A method for producing a hydraulic lightweight molded body characterized by being molded and cured.