JPS62253870A - Painting mold frame and its production - 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] <Industrial Application Field> The present invention relates to a formwork and a method for manufacturing the same, and more specifically to a coated formwork that is effectively used for concrete and mortaring in house construction, civil engineering work, etc. The aim is to provide a manufacturing method.

<Prior art> Conventional formwork is known to use plywood as is, but the concrete and mortar poured into the formwork adheres to the plywood surface of the formwork, making it difficult to remove the formwork. Because of this drawback, tar or paraffin/silicone-based release agents are applied to the plywood surface at construction sites to improve removability. In addition, in recent years, in order to prevent this concrete/mortar from adhering to the plywood surface, painted formwork has been manufactured by applying synthetic resin such as acrylic resin or urethane resin at the factory to form a coating layer on the plywood surface. (For example, Japanese Patent Publication No. 45-15064, Japanese Patent Publication No. 53-38728, Japanese Utility Model Publication No. 47-3)
Publication No. 0639).

<Problems to be solved by the invention> It is known from experience that when plywood is used as a formwork for pouring concrete, dark-colored poorly cured areas are formed at the concrete interface after the mold is released. . Since such concrete materials are unfavorable in appearance, when a wall is constructed by pouring concrete, it not only reduces the design of the wall but also significantly reduces its strength due to poor curing. In some cases, this poorly cured area is not limited to the surface layer, but affects several xz depths,
If you touch that part with your hand or an object, it turns into particles and falls off.

In addition, in the case of joint painting construction on a concrete surface, the joint mortar applied to the surface, the spraying material, etc.
The finishing coating material, tiling, etc., had the disadvantage of peeling off from poorly cured areas after construction, lifting up, and sometimes peeling off.

The formation of these poorly hardened areas is thought to be due to harmful substances contained in the formwork plywood leaching out of the wood and inhibiting the hydration reaction of cement, but the detailed mechanism is still not fully understood. Not yet.

In conventional painted forms, a synthetic resin coating layer is formed on the surface, so the elution of harmful substances from the wood is suppressed to some extent in the early stages of use, but the elution of harmful substances through pinholes in the coating layer is suppressed to some extent. This is unavoidable, and elution is likely to occur due to cracks in the paint film layer due to deterioration of the paint film, damage to the paint film layer due to external forces, etc. Therefore, contamination of the concrete surface and inhibition of curing due to the elution of harmful substances from the wood. It could not be used as a means to fundamentally solve the problem.

Means for Solving Problems〉 The present inventor has conducted various studies on the phenomenon in which components eluted from plywood formwork inhibit the hydration reaction of debris and lead to poor curing. Extracted components such as water-soluble cellulose, lignin, tannin, humic acid, and sugars are dissolved at the interface with the cement by the water in the cement slurry, and these extracted components are released from the cement.
It has been found that *, combines with Na 4 to form a salt, and as a result of the cement particles being covered with this salt, the subsequent hydration reaction of the cement is suppressed. That is, a normally hardened mortar dry product contains 2SO,
.

Although a large amount of Nn2SO4, Ca(01z) exists, in the case of poorly hardened mortar, the amount of these mixed together decreases,
In mortar with markedly poor curing, these were hardly present, and instead, a large amount of ettringite was observed. This is dissolved into the liquid phase during cement hydration and Kz
Nfl', K", Ca", which should be crystallized as SO<, NazSO<, Ca(OH)z, is adsorbed or chemically combined with the above extracted components eluted from the wood to form a complex salt, so it cannot crystallize. It is presumed that the excess S 2' crystallized into ettringite at that time.

The present invention was devised based on the above-mentioned findings after further study, and provides a painted formwork made by mixing a metal compound into a synthetic resin coating layer formed on the surface of plywood.

That is, in view of the fact that in the above-mentioned conventional technology, attempts were made to prevent the elution of harmful components from the wood by forming a coating HN on the surface of the form plywood, but the results were insufficient, We have moved away from the technical idea of simply physically preventing the elution of wood extract components, and from a chemical standpoint, we are looking at ways to prevent wood extract components from combining with free ions from cement to form complex salts. I thought about it a lot. As a result, by pre-binding wood extract components with metal ions that form complex salts that are more stable than these free ions, the wood extract components are more stably chelated with the metal ions, resulting in free release. It has been found that bonding with ions can be prevented. April 18, 1988, regarding plywood coated with or impregnated with gold B1 compound powder or aqueous solution on at least one surface of the veneer.
A patent application was filed on the same day, and the present invention was achieved by confirming that by applying this technical idea to a painted formwork, the desired effect could be achieved in combination with the formation of a coating layer. .

The configuration of the present invention will be explained below.

A mixture prepared by adding and mixing a metal compound powder or aqueous solution to a synthetic resin is applied to the surface of the plywood using a roll coater,
Apply using a coating device such as a flow coater.

As the synthetic resin, one type or a mixture of two or more types arbitrarily selected from acrylic type, urethane type, epoxy type, amino type, etc. can be used, and it may be water-based or oil-based.

In the present invention, the metal compound that is added and mixed with the synthetic resin is one that combines with extracted components such as cellulose, lignin, tannin, and sugars in the wood of the plywood to form a highly stable complex. The invention prevents wood extract components from combining with free ions from cement to form complex salts in the presence of water when plywood formwork is used, and instead allows them to combine with more stable metal ions. Therefore, the metal compound used is to elute metal ions that are soluble in water and have a higher stability than free cement ions, and combine with the wood extract components to form poorly soluble metal compounds. It must be able to form a complex salt. That is, the metal ions dissolved in the water contained in or permeated into the wood and the wood extract components combine to form a chemically stable complex salt. For example, one or more selected from sulfides, chlorides, hydroxides, etc. of iron, copper, zinc, lead, aluminum, etc. can be used alone, in combination, or in a mixture.

The metal compound to be added to the synthetic resin may be in the form of a powder or an aqueous solution, but if the synthetic resin is oil-based, it is necessary to add and mix it in the form of a powder.

After the synthetic resin mixed with the metal compound is applied to the plywood surface as described above, it is dried using a drying device, and the plywood surface is coated with the synthetic resin mixed with the metal compound JI!
A layered painted form is produced.

Effect> Since a synthetic resin coating layer is formed on the plywood surface of the formwork, the strength, abrasion resistance, and impact resistance of the surface are improved, similar to conventional painted formwork, and the cement! II. Release properties are improved. In addition, cellulose, tannin, lignin,
The elution of wood extracted components such as sugars into the cement slurry can be physically suppressed to some extent by forming a coating layer.

Furthermore, since metal compounds are mixed into the synthetic resin of the coating layer, the above-mentioned problems may occur due to pinholes that are inevitably formed in the coating layer, cracks in the coating layer due to deterioration, or damage to the coating layer due to external force. When the wood extract components are about to be eluted, these extract components chemically combine with the metal compound to form a stable insoluble complex inside. Therefore, these wood extract components are not eluted into the cement slurry.

Test Example> The effects of various metal compounds on the inhibition of cement hardening by wood extract components were tested.

Cement; Standard 1? Mixed at a ratio of l1 = 1: 2, various solutions were added at a water/cement ratio of o of 65.
Mix and prepare various types of green mortar, cast them into iron molds (1X1X4 cz), and cure for one day in a constant temperature bath with a temperature of 20'C and a humidity of about 8oz, and then in water at 20℃ for a predetermined period of time. , various mortar specimens were obtained. The mixed solution was made by soaking 18 pieces of lOxlOx1cm plywood in a saturated Ca(011)2 solution for 48 hours, then adding various copper compounds, zinc compounds, lead compounds, and aluminum compounds to the wood extract for 0.1$ each. , 0.3$.

0.5z and 1. It was added at a ratio of Og. For comparison, mortar specimens prepared by blending solutions to which these metal compounds were not added were also prepared.

Table 1 summarizes the results of measuring the compressive strength of these mortar specimens after curing and hardening for a predetermined period of time.

I, 1, ゛Copper chloride ◎ ○ ○(0,3
~0.5) Copper sulfate ◎ O○ (0,1~
1.0) Copper hydroxide OO× Zinc chloride O×
~0.3> (0,1~0.3) (0,3~0.
5) Zinc hydroxide ○ × ×Lead chloride ◎ ◎ ◎ (0,1~1
．． 0) (0,3~1.0) (0,3~1,0)
Lead sulfate ○ ◎ ◎(0,1
~0.5) (0,1~0.5) Lead hydroxide O
O× Aluminum chloride ◎ ◎ ◎(0,1
~1.0) (0,1~0.5) (0,3~0.
5) Aluminum sulfate ◎ ◎ O(0
,1~1.0) (0,3~1.0) Aluminum hydroxide
○ × ×ferric chloride ◎
O◎ 0.1 to 1.0 (0.1 to 0.5 0.3 to 0.5 In addition, in the compressive strength in Table 1, the mark X indicates mortar prepared using a solution without the addition of metal compounds. The O mark indicates that there was no increase in strength, the O mark indicates that there was a slight increase in strength, and the ◎ mark indicates that there was a significant increase in strength. The numerical value is the amount of metal compound added when the strength development reaches the maximum.

From the results shown in Table 1, although the effects are not necessarily constant depending on the type of metal compound and the amount added, it is generally possible to suppress the cement hardening inhibiting effect of wood extract components by incorporating these metal compounds. It is known that it is possible.

In particular, copper compounds include chlorinated steel and copper sulfide, and zinc compounds include sulfur I! It has been found that zinc 2, lead chloride and lead sulfate for lead compounds, aluminum chloride and aluminum sulfate for aluminum compounds, and iron chloride for iron compounds each have a significant inhibitory effect.

In addition, when we examined the fine structure of the mortar specimens that showed these remarkable inhibitory effects using a scanning electron mw1 mirror, we found that in all cases, gel-like particles were adsorbed and polymerization occurred due to chemical bonding. Fibrous, granular, or lumpy products were confirmed. This is Fe, which has greater stability than the ions Ca", K", Na', etc. aw1 from cement into the liquid phase.

Metal ions such as Cu, Zn, Pb, and ^1 were eluted from the added metal compound, and it was determined that these metal ions were complex salts produced by combining with wood extract components.

<Example> Various metal compound-blended resins were prepared by adding and mixing 6% each of powdered lead sulfate, zinc chloride, aluminum chloride, [1 aluminum and ferric chloride] to urethane resin. These were applied to the surface of plywood made of 3x6x12zx thick Melabi material using a roll coater in an amount ranging from 40 to 100 g/z2, and then dried to obtain various coated forms according to the present invention. .

These painted forms according to the present invention, conventional painted forms with a coating layer made only of urethane resin without the addition of metal compounds, and conventional plywood forms without a coating layer were used, After a day had passed, the concrete was removed from the mold, and the condition of the concrete surface was comparatively observed to investigate the effect of adding the metal compound to the synthetic resin of the coating layer. Furthermore, for the coated formwork according to the present invention and the conventional urethane coated formwork, the above method was performed for 1 cycle and 7 cycles, respectively, and the results were observed. The results are shown in Table 2 below.

As is clear from the results shown in Table 2, in the case of one cycle, concrete cured in a plywood form without a synthetic resin coating layer is
Curing inhibition was detected at depths of 4111 and the overall color was deep dark brown, whereas when a painter's frame was used, there was no curing inhibition and the surface color was not contaminated. . In the case of one cycle, no particular difference was observed between the coated formwork according to the present invention and the conventional method, but a significant difference was detected in the case of seven cycles. In other words, when using conventional urethane-coated formwork, 7
Discoloration can be seen on the concrete surface due to repeated use.
Curing inhibition was observed and mortar releasability was reduced, whereas these abnormalities were not detected at all when the coated formwork according to the present invention was used. In the case of 7 cycles, these different results were obtained even though there were cracks on the paint film surface in both cases. In contrast, in the present invention, even if cracks occur on the coating surface, the extracted components from It was determined that this was because the metal compounds added and mixed on the membrane surface chemically bonded the wood extract components that were about to elute from the cracks, effectively suppressing the elution of the extract components.

<Effects of the Invention> When using the painted formwork according to the present invention as described above, the advantages of conventional painted formwork such as improved surface strength, abrasion resistance, impact resistance, and improved cement releasability can be obtained. In addition to leaving it as it is without damaging it, wood extract components can be eluted from pinholes that are unavoidably formed in conventional paint layers, cracks in the paint layer due to deterioration, or damage to the paint layer due to external forces, which can inhibit the hardening of concrete. It is possible to completely eliminate the drawback that the design quality has deteriorated. Therefore, the durability of the painted formwork according to the present invention is significantly improved, and it is also excellent in economical efficiency.

Claims (3)

[Claims] (1) A painting form having a synthetic resin coating layer formed on its surface, characterized in that a metal compound is mixed into the synthetic resin coating layer. (2) The metal compound is characterized in that it consists of one or more substances selected from sulfides, chlorides, and hydroxides of iron, copper, zinc, lead, and aluminum;
A painted formwork according to claim 1. (3) A synthetic resin coating layer mixed with a metal compound is formed on the plywood surface by applying a synthetic resin mixed with a powder or aqueous solution of a metal compound to the plywood surface and then drying it. A method of manufacturing painted formwork.