JPS61229504A - Aqueous mold release for stainless formwork - 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] (Technical/Technical Field of the Invention) □ Unexploited - ° Soukinko" It is applied to the surface of the stainless steel formwork used when pouring Zocrite, and has a mold release effect. 1. A water-based mold release agent for stainless steel formwork □. 5. (.

(Technical background of the invention and its problems) The material of this type of formwork is generally wood, steel, synthetic resin or resin. FR□P is mainly used as resin material.
・In recent years, 4: h,, 'shi', □Integration of REIT structures into the surrounding environment: ``Improvement and □'' aims to create a more beautiful concrete town from the perspective of beautification of environmental tombs, etc. As finishing and □ finishing became required, the scrutiny of ``material vlL□'' extended to formwork for concrete and □reet.Recently, due to this demand, stainless steel formwork has become popular. This is now being considered in many workplaces.

Traditionally, iron formwork has been mainly used as formwork for concrete pouring at civil engineering sites, but it is prone to rust, takes time to clean the formwork after use, and has problems with service life and workability. There were problems with this, and the beauty of the finished concrete surface was also not satisfactory.

On the other hand, stainless steel formwork has the advantage of being less prone to rust, and it has been confirmed through actual use in the field that it has the potential to solve the above-mentioned problems of iron formwork, and has come to be recognized. For this reason, as mentioned above, there has recently been a growing trend to switch from iron formwork to stainless steel formwork.

However, the disadvantage of using stainless steel as the formwork material is the characteristics of the metal.

Because the metal surface is physically smooth and has low polarity, conventional mold release agents have a weak adhesion to the surface, causing it to run off without leaving much of a residue on the mold surface. Problems such as concrete falling off due to friction during pouring or adhesion to the formwork may occur, making it difficult to achieve smooth and stable ti.
The 11 type effect could not be obtained. In particular, if it comes into contact with rainwater after being applied to the formwork, it will wash away, making it impossible to use it many times.

As a mold release agent, an oil-based mold release agent is generally used, which is mainly made of mineral oil or vegetable oil and contains a nonionic or anionic surfactant as an additive.

For example, a series of cationic surfactants such as quaternary ammonia chloride were considered unsuitable for use because they tend to cause rust, especially in the case of iron molds.

Conventional oil-based mold release agents that use oil as a solvent and contain nonionic or anionic surfactants have a problem in that the oil adheres to the concrete surface during use. If such oils adhere, when a resin coating or the like is applied to the concrete surface as a post-treatment, the adhesion will be poor and it will be easy to peel off, which may reduce the quality of the product. Further, in the case of reinforced concrete, there is a problem that oil adheres to the reinforcing bars, and this may cause entanglement between the poured concrete and the reinforcing bars, significantly impairing their adhesion.

On the other hand, there are water-based mold release agents that are emulsified with nonionic or anionic surfactants using water as a solvent, but in this case, if the water evaporates after being applied to the formwork and comes into contact with rainwater, it will re-release. There was a problem that the mold release effect was significantly impaired because it emulsified and ran down.

(Objective of the Invention) Therefore, the present invention has been made to solve the various problems mentioned above, and its object is to:
It has good adhesion even to stainless steel formwork with high physical smoothness and low polarity, and after being applied to the frame, it does not wash off easily even if it comes into contact with rainwater, and has an excellent peeling effect for a long period of time. It is an object of the present invention to provide an aqueous mold release agent which is particularly suitable for stainless steel formwork and which can be maintained without any adverse effect on concrete or reinforcing steel.

(Summary of the Invention) In order to achieve the above object, in the present invention, fatty acids, particularly at least one of stearic acids and behenic acids, are used as the main component that has a mold release effect by using a cationic surfactant. An aqueous mold release agent for stainless steel molds is prepared by emulsifying and dispersing water using water as a solvent. Fatty acids themselves do not have a uniform form at room temperature, such as solid, liquid, or powder, and cannot be used as a mold release agent as they are. By emulsifying and dispersing stearic acids and behenic acids, which have a large amount of fatty acids, in water as a solvent using a cationic surfactant, the above fatty acids are adsorbed to the coated surface of the stainless steel formwork by the adsorption power of cations, resulting in effective release. It is designed to have a type effect.

By selecting fatty acids as the main component that exhibits the mold release effect, the negative effects of oily substances on concrete and reinforcing bars, such as a significant decrease in adhesion, are eliminated. This means that since water was used as a solvent,
This is thought to be because the absolute amount of fatty acids contained is very small, and the attached fatty acids react with the poured concrete to form fatty acid calcium and are integrated as a concrete composition.

Furthermore, as mentioned above, by using a cationic surfactant, a strong adsorption force can be obtained, and since it is used for stainless steel, there is no need to worry about the problem of rust caused by such an surfactant.

The present invention will be explained in detail below.

(Embodiment of the invention) A cationic surfactant is contained in fatty acids and water is used as a solvent to constitute an aqueous stripping agent, and the types and amounts of the fatty acids and cationic surfactant, and the amount of water are prepared. Various formulation examples were created by adjusting the amount. The prepared formulation example was applied to the surface of a stainless steel mold, and concrete was poured in to observe the adhesion of the mold release agent to the mold surface, the mold release effect, and the effect on the concrete.

As a result, as fatty acids, stearic acids and behenic acids having a relatively large number of carbon atoms are preferable, and as cationic surfactants, for example, quaternary ammonia chloride, ethanoylamine, stearylamide amine, etc. are preferable. It was found to be effective.

The blending ratio of each component is 8 to 25% by weight of stearic acids and behenic acid, 8 to 25% by weight of one or both, 5 to 10% of cationic surfactant, and 87 to 65% of water. % range showed good results.

In particular, it has been found that a combination of 5 to 15% by weight of stearic acid and 3 to 10% by weight of behenic acid is more desirable as fatty acids. This is thought to be because the molecular weights of the double-sided fatty acids are high on one side and low on the other, and both act synergistically to form a fine-grained peeling layer on the surface of the stainless steel mold.

In addition, the fatty acids may be composed of a mixture of double-sided fatty acids of stearic acid and behenic acid, and these fatty acids may be amide with ethanolamine. This was the case where 5% by weight of stearic acid monoalkanolamide as stearic acids, 3% by weight of ethanolamine behenate as behenic acids, 1% by weight of stearylamide amine si, and 87% by weight of water.

The aqueous mold release agent created as described above was tested several times using a concrete test piece, and after the water evaporated, it was released from the mold with fatty acids as the main component strongly adsorbed to the surface of the stainless steel mold. A layered film was formed, and this film exhibited properties that provided electrical bonding, did not run off even after several rainfall events, and had good resistance to friction during concrete pouring.

Therefore, an excellent mold release effect was obtained, and the mold release agent did not have any adverse effect on the concrete on the surface of the mold. This is thought to be because even if the mold release agent adheres to the concrete, the fatty acids react with the concrete and turn into fatty acid calcium, as described above, and are integrated as a concrete composition. This can be understood from the fact that these calcium fatty acids are commonly used as materials for cement, mortar, or concrete waterproofing agents.

Claims (5)

[Claims] (1) An aqueous mold release agent for stainless steel molds, characterized in that fatty acids of at least one of stearic acids and behenic acids are emulsified and dispersed with a cationic surfactant and water as a solvent. (2) Stearic acid 5-15% by weight, behenic acid 3-10%
The aqueous mold release agent for stainless steel molds according to claim 1, comprising 5 to 10% by weight of quaternary ammonia chloride and 87 to 65% by weight of water. (3) The aqueous mold release agent for stainless steel molds according to claim 2, which comprises 7% by weight of stearic acid, 6% by weight of behenic acid, 5% by weight of quaternary ammonia chloride, and 82% by weight of water. (4) Stearic acid monoalkanolamide 5% by weight
, 3% by weight of ethanolamine behenate, 5% by weight of stearylamide amine, and 87% by weight of water. (5) The aqueous mold release agent for stainless steel molds according to claim 1, wherein the fatty acids are a mixture of stearic acid and behenic acid, and these fatty acids are amidated with ethanolamine.