JP2003236819A - Mold release agent for form, and form - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold release agent for a form, which has excellent mold releasability, no lack of a concrete to be molded in the case of mold releasing, smooth surface of an obtained concrete, no bubble, no bubble mark, no stain, and excellent durability and which can be repeatedly used many times. <P>SOLUTION: The mold release agent for the form contains a silane coupling agent having at least one type or more of reactive functional group selected from the group consisting of an acryloyl group, and a methacryloyl group, an active hydrogen-containing amino group, an epoxy group, a vinyl group, a perfluoroalkyl group and a mercapto group. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold release agent for concrete formwork, and more specifically, a mold release agent for concrete formwork which has excellent mold release property and excellent durability that can be repeatedly used many times. It relates to a concrete formwork treated with the release agent.

[0002]

2. Description of the Related Art Conventionally, as a concrete formwork used for molding concrete, those made of metal such as iron and aluminum, wood such as natural wood and plywood, or plastic are widely used. These molds are usually used by applying a mold release agent containing mineral oil as a main component in order to improve the mold release property of concrete, and
Since the release agent used does not have a long-lasting release effect, it is applied to the mold before pouring concrete.

However, in the case of a metal mold, a mold release agent is applied to the mold before pouring concrete, but the mold release agent generally used is mainly composed of mineral oil. In addition to insufficient moldability, it is difficult to uniformly coat the surface of the mold with a low-viscosity liquid, uneven coating is likely to occur, and mold releasability becomes uneven. Therefore, at the time of demolding, the molded concrete is chipped off, or the concrete adheres to the form, and the part of the concrete that has fallen off must be repaired or the concrete adhering to the form must be removed. Further, since a mold release agent which is generally used inhibits the hardening reaction of concrete, the hardening of the surface is slow, and it takes a long time to completely harden it, and in a general example, a period of about one month is required. It is necessary, and it is necessary to store the concrete product produced during this period, leaving a big problem that productivity is extremely low.

Further, since bubbles and traces of bubbles are generated on the surface of the molded concrete, the smoothness of the surface is inferior.
Since the surface is contaminated in a stain shape by the release agent, the aesthetic appearance is impaired, and when aesthetic appearance is required, the entire surface needs to be repaired. Therefore, in JP-A-2-190306, a mold releasing agent for cement is characterized in that it contains an organopolysiloxane having a siloxane unit having an alkyl group having 2 or more carbon atoms and a hydrolyzable group bonded to the surface of the mold. Although a coating method is described, the purpose is to form a water-repellent and salt-barrier surface layer on the concrete surface, and there is a problem in releasability from the mold and durability.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is excellent in mold releasability, and when the mold is released, the molded concrete does not drop off and the surface of the obtained concrete is smooth. A concrete mold that has no bubbles, bubble traces, or stains, has excellent durability that can be used many times, and has a hardened concrete surface that can be shortened in the time until it is completely cured after being taken out from the formwork. It is intended to provide a mold release agent for a frame and a mold surface-treated with the mold release agent.

[0006]

Means for Solving the Problems The present inventors have found that at least one or more types of reactive groups selected from acryloyl group, methacryloyl group, active hydrogen-containing amino group, epoxy group, vinyl group, perfluoroalkyl group and mercapto group. By using a mold release agent characterized by containing a silane coupling agent having a functional group, concrete hardened by heating and curing can be easily taken out from the mold, and the hardened concrete The surface of is very smooth, and after heating and curing for several hours, the surface immediately after being taken out from the mold is very hard, and it is possible to significantly shorten the time until it completely cures. It was found that a surprising effect, which was completely unthinkable, was developed, and the present invention was completed. That is, the present invention is as follows.

1. Acryloyl group, methacryloyl group,
A mold releasing agent containing a silane coupling agent having at least one reactive functional group selected from an active hydrogen-containing amino group, an epoxy group, a vinyl group, a perfluoroalkyl group and a mercapto group. Mold agent. 2. 1. The form is made of metal. The mold release agent described. 3. The above 1. A mold which has been surface-treated with the silane coupling agent according to 1. 4. The above 1. A method for surface treatment of a mold, which comprises using the silane coupling agent according to 1.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail. The silane coupling agent used in the present invention is a compound having in its molecule a functional group having high reactivity with a surface hydroxyl group of a substrate, and such a functional group is, for example, a trimethoxysilyl group or triethoxysilyl group. Group, trichlorosilyl group, diethoxysilyl group, dimethoxysilyl group, dimonochlorosilyl group, monoethoxysilyl group,
Examples thereof include a monomethoxysilyl group and a monochlorosilyl group. Further, at least one or more of these functional groups are present in the molecule, and are immobilized on the surface of the base material by reacting with the surface hydroxyl groups of the base material. Further, the compound constituting the silane coupling agent of the present invention is selected from an acryloyl group, a methacryloyl group, an active hydrogen-containing amino group, an epoxy group, a vinyl group, a perfluoroalkyl group and a mercapto group as a reactive functional group in the molecule. And has at least one functional group. The structure is not particularly limited, but specific examples can be selected and used from the following groups (a) to (g).

(A) having an acryloyl group γ-acryloxypropyltrimethoxysilane (b) having a methacryloyl group γ-methacryloxypropyltriethoxysilane, γ-
Methacryloxypropyl methyldiethoxysilane, γ-
Methacryloxypropyltrimethoxysilane, and γ-
Methacryloxypropylmethyldimethoxysilane (c) Having an active hydrogen-containing amino group γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ
-Aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-
Ureidopropyltriethoxysilane and N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane

(D) Epoxy group-containing γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β- (3.
4 Epoxycyclohexyl) ethyltrimethoxysilane (e) having vinyl group vinyltriethoxysilane, and vinyltrimethoxysilane (f) having mercapto group γ-mercaptopropyltrimethoxysilane, and γ-
Mercaptopropylmethyldimethoxysilane

(G) Having perfluoroalkyl group CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OC
H ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCH
₃ (OCH ₃ ) ₂ , CF ₃ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₇ CH ₂
CH ₂ SiCl ₃ The mold release agent of the present invention is prepared by diluting the above silane coupling agent with water-alcohol or acetic acid water-alcohol mixed solution, if necessary. The concentration of the silane coupling agent in the mold release agent is preferably 0.05 to 10.0% by weight.

The surface coating method using the mold release agent according to the present invention will be described. The mold release agent containing the above-mentioned silane coupling agent is applied to the surface of the mold for use. The material of the mold is not particularly limited, but metal is particularly effective for the present invention. The method of applying the release agent to the mold is not particularly limited, and for example, a dipping method, a spray method, a roll coating method, a brush coating method or the like can be applied. Further, the coating treatment temperature and the coating treatment time are not particularly limited, but are preferably 5 to 60 ° C., and the treatment time is preferably 0.1 to 60 seconds. Further, it is preferable to dry the treatment liquid layer on the surface of the mold under heating, and the heating temperature is preferably 50 to 150 ° C.

Non-destructive inspection such as Schmidt hammer test is generally widely used as a method for evaluating the physical properties of cured concrete. This method is a method of hitting a steel ball on the surface of concrete, and is known as a method of estimating strength without breaking concrete. According to this method, the strength of concrete is indirectly estimated by utilizing the characteristics that concrete having high strength has a high degree of repulsion of steel balls and concrete having low strength has low degree of repulsion of steel balls. In the present invention, based on this method, a diameter of 10.9
In the following examples, the strength of concrete was compared by using a method of dropping a steel ball having a weight of 5 mm and a weight of 5.4 g from a height of 30 cm onto the concrete surface and measuring the height at which the steel ball repels.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

[0015]

Example 1 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (1). γ-acryloxypropyltrimethoxysilane 5 g Methanol 944 g Acetic acid 1 g Water 50 g The mold release agent (1) for a mold is evenly and thinly coated on the inner surface of a metal mold, and the mold is dried at 100 ° C. for 10 minutes, and the mold is then dried. Pour into 100 parts by weight of Poldland cement, 200 parts by weight of sand, 300 parts by weight of gravel, 60 parts by weight of water, and pour, and heat for 4 hours in a steam bath at 60-65 ° C, then at room temperature for 30 minutes. Allowed to cool and harden the concrete.

The hardened concrete was easily released from the metal mold, and the surface of the obtained concrete was smooth,
There were no deposits, and the release agent applied inside the mold was still completely attached to the mold surface. Furthermore, after the concrete was released, the metal mold was repeatedly used without applying the mold release agent, but the mold could be smoothly released even after 10 times of repeated use. Was smooth and free of any deposits. In addition, a steel ball with a diameter of 10.95 mm and a weight of 5.4 g is placed on the concrete surface at a height of 3
It was dropped from 0 cm, and the height at which the steel ball repelled was measured and found to be 10 cm.

[0017]

Example 2 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (2). γ-Aminopropyltrimethoxysilane 5 g Methanol 332 g Water 663 g The above mold release agent (2) was applied evenly and thinly on the inner surface of the metal mold, dried at 100 ° C. for 10 minutes, and then poured into the mold. 100 parts by weight of land cement, 200 parts by weight of sand, 300 parts by weight of gravel, 60 parts by weight of water are poured into the concrete, heated for 4 hours in a steam bath at 60-65 ° C., and then allowed to cool at room temperature for 30 minutes. To cure the concrete. After a further 2 hours, the hardened concrete was removed from the formwork.

The hardened concrete was easily released from the metal mold, and the surface of the obtained concrete was smooth,
There were no deposits, and the release agent applied inside the mold was still completely attached to the mold surface. A test of hitting the surface of the concrete taken out from the mold with a hammer was carried out. As a result, several recesses of less than 1 mm were generated on the surface, but no cracks or the like were generated. The hammer used is made of steel, the surface to be lowered is flat, and the diameter is approximately 5
It had a circular shape of 0 mm and weighed about 2 kg.
This hammer was hit from the height of about 30 cm at the same place on the concrete surface five times by a method of dropping the hammer by its own weight without applying force.

Further, it was confirmed that the period until complete curing was 10 days, which was significantly shorter than the conventional method of 30 days. Furthermore, the metal mold was repeatedly used without applying the mold release agent, but the mold was still smoothly released after 10 times of repeated use, and the surface of the obtained concrete was smooth, and There were no deposits. Further, it was found that rust did not occur on the surface of the mold and that it had a rust preventive effect.
Further, when a steel ball having a diameter of 10.95 mm and a weight of 5.4 g was dropped from a height of 30 cm on the concrete surface and the height at which the steel ball repelled was measured, it was 12 cm.

[0020]

Example 3 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (3). γ-methacryloxypropyltrimethoxysilane 10 g Methanol 939 g Acetic acid 1 g Water 50 g As in Example 1, the mold release agent (3) for a mold is uniformly and thinly coated on the inner surface of the metal mold, and the temperature is maintained at 100 ° C. for 10 minutes. After drying for one minute, 100 parts by weight of Poldland cement and sand 2 in the mold.
Fresh concrete consisting of 00 parts by weight, 300 parts by weight of gravel, and 60 parts by weight of water was poured and heated in a steam bath at 60-65 ° C for 4 hours, and then allowed to cool at room temperature for 30 minutes to cure the concrete.

The hardened concrete was easily released from the metal mold, and the surface of the obtained concrete was smooth,
There were no deposits, and the release agent applied inside the mold was still completely attached to the mold surface. Furthermore, after the concrete was released, the metal mold was repeatedly used without applying the mold release agent, but the mold could be smoothly released even after 10 times of repeated use. Was smooth and free of any deposits. In addition, a steel ball with a diameter of 10.95 mm and a weight of 5.4 g is placed on the concrete surface at a height of 3
It was dropped from 0 cm, and the height at which the steel ball repelled was measured and found to be 10 cm.

[0022]

Example 4 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (4). Vinyltriethoxysilane 5 g Ethanol 944 g Acetic acid 1 g Water 50 g The mold release agent (4) for a mold is evenly and thinly applied to the inner surface of a metal mold, and dried at 100 ° C. for 10 minutes, and then Poldland is put in the mold. Fresh concrete consisting of 100 parts by weight of cement, 200 parts by weight of sand, 300 parts by weight of gravel and 60 parts by weight of water was poured and cured at 20 to 30 ° C. for 7 days. The hardened concrete was easily released from the metal mold, the surface of the obtained concrete was smooth and free of any deposits.
Further, the release agent applied inside the mold was still completely attached to the surface of the mold.

Further, after the concrete was released from the mold, the metal mold was repeatedly used without applying the mold release agent.
The mold could be released smoothly even after repeated use of 0 times, and the surface of the obtained concrete was smooth and free from any deposits. Also, on the concrete surface, a diameter of 10.95 mm,
A steel ball weighing 5.4 g was dropped from a height of 30 cm, and the height at which the steel ball repelled was measured and found to be 9 cm.

[0024]

Example 5 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (5). γ-Mercaptopropyltrimethoxysilane 10 g Methanol 939 g Acetic acid 1 g Water 50 g As in Example 1, the mold release agent (5) for a mold is uniformly and thinly coated on the inner surface of the metal mold, and the temperature is 100 ° C. for 10 minutes. After drying, 100 parts by weight of Poldland cement and sand 2 in the mold
Fresh concrete consisting of 00 parts by weight, 300 parts by weight of gravel, and 60 parts by weight of water was poured and heated in a steam bath at 60-65 ° C for 4 hours, and then allowed to cool at room temperature for 30 minutes to cure the concrete.

The hardened concrete was easily released from the metal mold, and the surface of the obtained concrete was smooth,
There were no deposits, and the release agent applied inside the mold was still completely attached to the mold surface. Furthermore, after the concrete was released, the metal mold was repeatedly used without applying the mold release agent, but the mold could be smoothly released even after 10 times of repeated use. Was smooth and free of any deposits. In addition, a steel ball with a diameter of 10.95 mm and a weight of 5.4 g is placed on the concrete surface at a height of 3
The height at which the steel balls repelled was measured from 0 cm, and it was 9 cm.

[0026]

Example 6 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (6). Perfluoroalkyl group-containing silane coupling agent (trade name "TSL8233" manufactured by GE Toshiba Silicone Co., Ltd.) 10 g Methanol 939 g Acetic acid 1 g Water 50 g As in Example 1, the mold releasing agent for the above mold was formed on the inner surface of the metal mold ( 6) is applied evenly and thinly and dried at 100 ° C for 10 minutes, and then 100 parts by weight of Poldland cement and sand 2
Fresh concrete consisting of 00 parts by weight, 300 parts by weight of gravel, and 60 parts by weight of water was poured and heated in a steam bath at 60-65 ° C for 4 hours, and then allowed to cool at room temperature for 30 minutes to cure the concrete.

The hardened concrete was easily released from the metal mold, and the surface of the obtained concrete was smooth,
There were no deposits, and the release agent applied inside the mold was still completely attached to the mold surface. Furthermore, after the concrete was released, the metal mold was repeatedly used without applying the mold release agent, but the mold could be smoothly released even after 10 times of repeated use. Was smooth and free of any deposits. In addition, a steel ball with a diameter of 10.95 mm and a weight of 5.4 g is placed on the concrete surface at a height of 3
It was dropped from 0 cm, and the height at which the steel ball repelled was measured and found to be 10 cm.

[0028]

[Comparative Example 1] The same metal mold as in Example 1 was used, and the same fresh concrete as in Example 1 was poured into the mold without applying the mold release agent, and the mold was heated in a steam bath at 60-65 ° C for 4 hours. Then, it was left to cool at room temperature for 30 minutes to cure the concrete. The hardened concrete had a very poor mold releasability from the metal mold, and at the time of mold release, part of the molded concrete fell off or the concrete adhered to the mold. Example 2
Similarly to the above, when a test of hitting the surface of the concrete taken out from the mold with a hammer was carried out, countless recesses having a depth of several mm were generated and cracks were also confirmed. Further, it took 30 days to completely cure the concrete taken out from the mold. Also, a steel ball with a diameter of 10.95 mm and a weight of 5.4 g is 30 cm in height on the concrete surface.
It was dropped from, and the height at which the steel ball repelled was measured,
It was 4 cm.

[0029]

Comparative Example 2 The following composition was stirred at room temperature (25 ° C.) for 1 hour to obtain a mold release agent (7). Dimethylpolysiloxane (trade name "KF-96-100" manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g n-hexane 900 g As in Example 1, the mold release agent (7) for the mold was formed on the inner surface of the metal mold. Is evenly and thinly applied, and after drying at 100 ° C. for 10 minutes, the same fresh concrete as in Example 1 is poured and 60-
After heating in a steam bath at 65 ° C. for 4 hours, it was allowed to cool at room temperature for 30 minutes to cure the concrete.

The hardened concrete had a poor releasability from the metal mold, and at the time of releasing the mold, a part of the molded concrete fell off or the concrete adhered to the mold.
When a test of hitting the surface of the concrete taken out from the mold with a hammer was conducted in the same manner as in Example 2, countless recesses having a depth of several mm were generated and cracks were also confirmed.
Further, when a steel ball having a diameter of 10.95 mm and a weight of 5.4 g was dropped from a height of 30 cm on the concrete surface and the height at which the steel ball repelled was measured, it was 5 cm.

[0031]

The mold release agent of the present invention is excellent in mold releasability from the concrete surface, while the mold release agent itself is firmly held on the mold surface. Therefore, the mold whose surface is coated with the mold releasing agent of the present invention can be repeatedly used many times and has durability. At the same time, the obtained concrete surface is extremely smooth. Further, the hardness of the concrete surface is high, and the period until the concrete is completely hardened can be greatly shortened. Furthermore, the anticorrosion effect of the formwork is also high. The present invention is particularly effective for metal molds.

Claims (4)

[Claims] 1. A silane coupling agent having at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an active hydrogen-containing amino group, an epoxy group, a vinyl group, a perfluoroalkyl group and a mercapto group. A mold release agent characterized by containing. 2. The mold release agent according to claim 1, wherein the mold is made of metal. 3. A mold which has been surface-treated with the silane coupling agent according to claim 1. 4. A surface treatment method for a mold, which comprises using the silane coupling agent according to claim 1.