JPH0748926A - Form - Google Patents

Abstract

PURPOSE:To lighten bad influence on concrete under curing caused by cold in wintertime by a method wherein an ultrathick coating is formed over the interior surface of a form with polyurethane resin with which no solvent is mixed. CONSTITUTION:A coating film layer 2, made of two-component polyurethane resin made up by blending paint liquid and hardening agent in specified percentage by volume, is formed in a specified ultrathick coating over the entire area on the interior of a form main body 1. The work is made, for instance, by spraying the coating material under the warmed molten state with a coating machine for its exclusive use while the thickness of coating is controlled with instruments that measure consumption of the coating material and the thickness of coating. As the solvent is not included, drying and hardening can be made quickly without allowing sags and pinholes to occur, and the coating film layer excellent in corrosion resistance and shockproofness can be formed. Since concrete is not adhesive to the removed form because of a low friction coefficient in the coating film layer made of polyurethane resin, the form can be used repeatedly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formwork mainly used for producing concrete structures in winter.

[0002]

2. Description of the Related Art A formwork is used as a temporary formwork for constructing a concrete structure having a predetermined shape and size, and a wooden formwork or a steel formwork (metal foam) is used. And in the winter, as the result of freezing of the water in the concrete poured into the formwork, the concrete itself may become brittle. In some cases, a warm air heater was used or a light bulb was lit while covering with a sheet.

On the other hand, since concrete that has agglomerated on the surface of the mold adheres to the removed mold, a release agent is applied to the inside of the mold for the wooden mold in order to prevent this adhesion. The steel formwork was painted with mineral oil.

However, as described above, there are problems that the prevention of freezing and the prevention of adhesion of concrete are troublesome and costly.

[0005]

Therefore, the present invention has been made based on the above-mentioned circumstances, and it is possible to contribute to prevention of freezing during concrete curing, and to prevent a concrete form from adhering to the inner surface of the removed formwork. The purpose is to provide.

[0006]

In order to achieve the above-mentioned object, the structure of the present invention is that an ultra-thick coating layer made of polyurethane resin that does not mix solvent is provided on the inner surface side of the mold body. Characterize.

[0007]

[Function] In normal coating with solvent mixture, thick film coating is not possible due to the dripping flow of solvent, but with polyurethane resin that does not contain solvent, it is possible to coat ultra-thick film with the above configuration. Is. And since the coating layer of the ultra-thin film made of polyurethane resin provided on the inner surface side of the mold body has the property that the specific heat is large and the thermal conductivity is small, the adverse effect of cold air in the winter on concrete during curing is prevented. Play a mitigating role.

That is, since the specific heat is the heat capacity, the polyurethane resin having a relatively large specific heat has a thermal ability to prevent the water in the concrete under curing in the mold from being frozen. It is thought that the ability is effectively exhibited in combination with the large heat insulation.

Further, the coating layer made of polyurethane resin has a small coefficient of friction, and concrete does not adhere to the removed formwork.

Furthermore, since the coating layer of polyurethane resin is excellent in impact resistance and abrasion resistance, the mold can be repeatedly used.

[0011]

Embodiments of the present invention will now be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a steel mold body, and the structure of the mold body 1 is basically the same as that of the conventional mold, but in the case of the present invention, the mold is used. Frame body 1
A coating layer 2 made of polyurethane resin coated without mixing solvent with a thickness of 0.5 mm to 2 mm
The greatest feature is that it is provided with the thickness of.

As the polyurethane resin applied without mixing the above solvent, a two-component solventless polyurethane resin paint in which the volume ratio of the coating liquid and the curing agent is 3: 1 is used.
The composition components of the coating liquid are 55% polyol resin and 3 coloring pigments.
3%, extender pigment 3%, additive 9%, and the composition of the curing agent is 100% modified isocyanate resin. As a property, it is characterized by being excellent in impact resistance and abrasion resistance and having a large specific heat. In this example, for the polyurethane resin containing no solvent, the trade name “Mizeron S-1” manufactured by Mitsui Metal Coating Chemicals, Inc.
00 / A-1000 "was used.

When coating the inner surface of a steel mold body, in order to firmly and tightly bond the mold body 1 and the coating layer 2, the metal surface is first roughened, that is, a so-called blast treatment. After that, the surface is cleaned and primed with MIZERON R primer (trade name; manufactured by Mitsui Kinzoku Kagaku Co., Ltd.), and then the MIZERON S-100 / A-100 described above.
No. 0 is sprayed with a uniform thickness with a film thickness of approximately 0.5 mm to 2 mm by a dedicated coating machine to form the coating layer 2. At this time, the film thickness is controlled by coating and controlling the amount of paint used and the wet film thickness meter. In addition, the MIZERON R primer for undercoating is a two-component polyurethane resin paint, the composition component of the paint liquid is epoxy modified polyol resin, pigment, additive, aromatic ketone solvent, and the curing agent is modified isocyanate. It is made of a resin, which is appropriately mixed and mixed, and is applied by airless coating or brush coating at a rate of 0.10 Kg / m ² .

The exclusive coating machine of MIZERON S-100 / A-1000 has a structure in which spray coating is carried out in a heated and melted state from the components of the coating material which does not mix the solvent. The coating liquid and the curing agent are separately heated to 45 ° C to 50 ° C separately and uniformly mixed in order to facilitate downward atomization and to accelerate reaction curing and prevent sagging of the coating film. It can be atomized and sprayed.

By spraying the two-component solventless polyurethane resin coating (trade name: Mizeron) on the inner surface side of the steel mold body 1 using the above-mentioned exclusive coating machine, a desired film thickness can be obtained by one spraying. Since it can be applied to, and it does not contain a solvent, it dries and cures quickly without sagging or pinholes, and the coating film is tough, the surface finish is smooth and the friction resistance is small. In addition, it is possible to form the coating film layer 2 which is excellent in abrasion resistance and impact resistance and also excellent in non-adhesion of concrete. In particular, the coating layer 2 has flexibility even at low temperatures and exhibits wear resistance and impact resistance.

The film thickness of the coating film layer is preferably about 0.5 mm to 2 mm, but it is not necessarily limited to this thickness, as long as it is within a range that does not hinder the use of the mold. The film thickness may be more than that.

It goes without saying that the invention also applies to wooden formwork. In this case, MIZERON SEALER U-60 (trade name; manufactured by Mitsui Kinzoku Kagaku Kagaku Co., Ltd.) is used as an undercoating paint for ensuring strong and close adhesion between the wooden form and the coating layer. The MIZERON SEALER U-60 is a one-component polyurethane resin paint, and the composition is a mixture of a moisture-curable polyurethane resin, an aromatic hydrocarbon solvent and an ester solvent.

[0019]

As described above, according to the present invention, the coating layer of the ultra-thin film made of polyurethane resin is fixed to the entire inner surface of the mold body, so that the curing is performed during the curing. Concrete has a large specific heat and a small thermal conductivity, and the thermal capacity and adiabatic performance of the ultra-thin film coating layer mitigate the adverse effects of cold air in the winter and prevent the freezing of water in the concrete. It is convenient because it is not necessary to heat with a heater or a light bulb.

Further, since the surface of the coating layer is smooth and has excellent releasability, it is convenient because there is no fear that concrete lumps will adhere to the inner surface of the removed mold.

Further, since the coating layer adheres tightly to the mold body and has excellent impact resistance and abrasion resistance, it has sufficient toughness so that the mold can be repeatedly used. ing.

[Brief description of drawings]

FIG. 1 is a perspective view showing a mold according to the present invention in a cutaway manner.

[Explanation of symbols]

 1 Formwork body 2 Coating layer

Claims (1)

[Claims] 1. A formwork, characterized in that an ultrathick coating layer (2) made of a polyurethane resin that does not mix a solvent is provided on the inner surface side of the formwork body (1).