JPH0584342B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Field of Application> The present invention relates to a base material for construction, and more particularly to a base material for construction on which a finishing coating material or paint can be applied and formed on the surface of the structural material immediately after construction. <Prior art> Various types of building materials have been proposed and put into practical use as this type of base material for construction. For example, a waterproof layer made of synthetic resin, latex, bituminous material, etc. is formed on a wooden substrate. A building material is known in which a layer of a mixture consisting mainly of cement mortar and optionally mixed with a synthetic resin or the like is formed thereon. <Problems to be solved by the invention> In these conventional building materials, wood lath,
Achieves the omission of base processes such as pasting lath baseboards such as plywood, pasting waterproof paper, pasting lath, and undercoating with mortar.A mixture layer with excellent adhesion to mortar is formed on the surface, making it suitable for use on walls, etc. It has the advantage of being able to be coated with mortar immediately after construction. However, when forming a mixture layer on a waterproof layer in conventional construction base materials, even if conditions such as cement/water ratio or cement/sand ratio are appropriately selected, the hydration reaction does not always occur sufficiently. It is considered a problem that the mortar in the mixture layer is inhibited from curing, leading to a decrease in the strength and adhesion of the mixture layer. It is assumed that this is because harmful components extracted from the wood that makes up the base material pass through the waterproof layer and elute into the moisture in the cement slurry, inhibiting cement hardening, but the specific mechanism is still unclear. has not yet been elucidated. In addition, the wood extract components are also eluted by the moisture in the mixture layer and are fixed within the mixture layer and on its surface, so the cement mortar that is applied on top of it after construction as a base material also hardens. This may cause the overcoat mortar to lift or peel off, etc.
It was a big problem. <Means for Solving the Problems> Apart from the technical field to which the present invention pertains, the present inventor has discovered that even in plywood formwork, components eluted from wood inhibit the hydration reaction and cause poor curing. As a result of various studies on this phenomenon, we found that extracted components such as water-soluble cellulose, lignin, tannin, humic acid, and sugar contained in wood are mixed with cement by the water in cement slurry. These extracted components dissolve at the interface and combine with Ca ²⁺ , K ⁺ , and Na ⁺ released from the cement to form salts.
It has been found that as the cement particles are covered with this salt, the subsequent hydration reaction of the cement is suppressed. In other words, a normally cured dry mortar contains a large amount of K ₂ SO ₄ , Na ₂ SO ₄ , and Ca(OH) ₂ , but in the case of poorly cured mortar, the amount of these components decreases. In mortar with markedly poor curing, these were hardly present, and instead a large amount of ettringite was observed. This dissolves into the liquid phase during cement hydration and produces K ₂
Should crystallize as SO ₄ , Na ₂ SO ₄ , Ca(OH) ₂
Na ⁺ , K ⁺ , and Ca ²⁺ are adsorbed by the above-mentioned extract components eluted from the wood or chemically bonded to form complex salts, so they cannot crystallize, and at that time, excess SO ₄ ^{2 -} is presumed to have crystallized into ettringite. Based on the above findings, we have repeatedly considered from a chemical standpoint the means to prevent wood extract components from combining with free ions from cement to form complex salts, and have found that wood extract components are more stable than these free ions. By pre-binding with metal ions that form highly complex salts, the wood extract components can more stably chelate with the metal ions and, as a result, can prevent binding with free ions; It has been found that inhibition of cement hardening can be prevented. The company then filed a patent application on April 18, 1988, for a plywood coated or impregnated with a metal compound powder or aqueous solution on at least one surface of the veneer. The present invention was devised to apply this technical idea to architectural base materials, and includes a wooden substrate, a waterproof coating made of synthetic resin, latex, or bituminous material formed on the surface of the wooden substrate, A layer comprising a hydraulic binder formed on the waterproof coating, a mixture layer containing a synthetic resin, latex, or bituminous material, and arbitrary aggregate, in which a metal compound is further mixed into the waterproof coating. The object of the present invention is to provide a base material for construction that is characterized by: The structure of the construction base material according to the present invention will be explained below. First, the material forming the base material of the base material is a wood board such as plywood, wood fiberboard, or wood chipboard. A synthetic resin mixed with a metal compound, latex, bituminous material, or an emulsion thereof is applied to the surface of this wooden substrate using an appropriate coating device such as a roll coater or a flow coater, and then dried to form a waterproof coating. form a layer. Synthetic resins include vinyl acetate resin, vinyl chloride resin, acrylic resin, epoxy resin, etc. Latexes include acrylonitrile butadiene rubber (NBR), butadiene acrylic rubber (MBR), styrene butadiene rubber (SBR), etc. As the blue material, tar, asphalt, etc. can be selected, and these can be appropriately used alone or in combination or in a mixture of several kinds. The metal compound used in the waterproof coating in the present invention 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 present invention aims to prevent wood extract components that are about to be eluted from the wood substrate through the waterproof coating layer from binding with metal ions in advance, thereby preventing the binding with free cement ions and the resulting inhibition of mortar hardening in the mixture layer. Therefore, the metal compound used is one that elutes metal ions that are soluble in water and have a higher stability than free cement ions, and combines with wood extract components to form poorly soluble complex salts. There must be. That is, it combines with wood extract components dissolved in water in wood and emulsion-type coating materials that form waterproof layers to form chemically stable complex salts. For example, one or more selected from sulfides, chlorides, hydroxides, etc. of iron, copper, zinc, lead, aluminum, etc.
They can be used alone, in combination, or in a mixture. If necessary, auxiliary agents such as aggregate (talc, clay, charcoal, etc.), fillers, dispersants, thickeners, antifoaming agents, etc. can be added to this waterproof coating layer. On the waterproof coating layer, a mixture layer is formed by mixing a hydraulic binder such as cement, granulated slag, gypsum, or lime, a synthetic resin, latex, or bituminous material, any aggregate, and water. Form. This mixture layer may have a smooth surface or a rough surface made of aggregate, or may be formed to have an arbitrarily uneven surface shape. Synthetic resins, latex, bituminous substances, etc. in the mixture layer are blended to enhance adhesion with the waterproof coating layer through intermolecular attraction with these substances forming the waterproof coating layer. Therefore, it is preferable to use the same kind of material as the material in the waterproof coating layer. Aggregates include inorganic aggregates such as calcium carbonate, talc, clay, fly ash, and incineration ash, inorganic foam aggregates such as vermiculite, expanded negative rock, expanded clay, perlite, and shirasu balloons, and organic materials such as polyethylene beads and polystyrene beads. The material may be any material selected from aggregates, foamed organic aggregates such as foamed polyethylene beads, and polystyrene beads, and these materials may be used alone or in an appropriate mixture. The aggregate may be colored in any color if necessary. Using inorganic or organic foam as aggregate not only contributes to the weight reduction of the building base material itself, making it easier to transport and install, but also improves workability during nailing, cutting, etc. Therefore, this is a particularly preferred embodiment. <Function> Metal compounds are added and mixed into the waterproof coating in architectural base materials, and the emulsion-type coating material that forms this waterproof coating is applied onto the wooden substrate, allowing moisture to penetrate into the coating material. Along with this, metal compounds simultaneously penetrate or remain in the coating material.
Therefore, cellulose, tannin, and lignin that try to elute from the wood substrate through the waterproof coating layer,
Wood extract components such as sugars combine with the metal compound to form a stable complex salt. Therefore, these wood extract components do not dissolve onto the waterproof coating and affect the mortar of the surface mixture layer. <Test Example> The influence of various metal compounds on the inhibition of cement hardening by wood extract components was tested. A mixture of cement and standard sand at a ratio of 1:2 was mixed with various solutions at a water/cement ratio of 0.65 to prepare various green mortars, and these were placed in iron molds (1 x 1 x 4 cm). and temperature 20
After curing for one day in a constant temperature bath at 80% humidity and 20°C, various mortar specimens were obtained. The mixed solution is 10×10×1
Various copper compounds, zinc compounds, lead compounds, and aluminum compounds were added to the wood extract obtained after soaking 18 cm of plywood in saturated Ca(OH) ₂ solution for 48 hours.
They were added in proportions of 0.1%, 0.3%, 0.5% and 1.0%. 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.

[Table] Regarding the compressive strength in Table 1, × marks indicate no increase in strength compared to mortar prepared using a solution containing no metal compounds, and ○ marks indicate a slight increase in strength. The ◎ marks indicate those in which the strength increased significantly. Moreover, the numerical value shown in the box under the mark ◎ is the amount of metal compound added when the strength development reaches the maximum. From the results shown in Table 1, although the effect is not necessarily constant depending on the type of metal compound or the amount added, it is generally found that mixing these metal compounds can inhibit the cement hardening effect of wood extract components. It is known that it can be suppressed. In particular, copper compounds include copper chloride and copper sulfide, zinc compounds include zinc sulfate, lead compounds include lead chloride and lead sulfate, aluminum compounds include aluminum chloride and aluminum sulfate, and iron compounds include iron chloride. ,
It was found that each had a remarkable inhibitory effect. Furthermore, when we investigated the fine structure of the mortar specimens in which these remarkable inhibitory effects were obtained using a scanning electron microscope, we found that in both cases, gel-like particles were adsorbed and chemical bonding was observed. Polymerized fibrous, granular, or lumpy products were confirmed. This is because metal ions such as Fe, Cu, Zn, Pb, and Al, which have greater stability than the ions Ca ²⁺ , K ⁺ , Na ⁺ , etc. released from cement into the liquid phase, elute from the added metal compounds. It was determined that these metal ions were complex salts produced by combining with wood extract components. <Example> Using a roll coater, 50% of latex (MBR) mixed with 5% of a metal compound was applied to the surface of a structural plywood board made of merape material with a thickness of 3 x 6 x 6 mm.
~100 g/m ² was applied and dried to form a waterproof coating layer. Next, 100 parts of cement, 30 parts of synthetic resin, and 40 parts of water.
A mixture is prepared by mixing at a weight ratio of 2 to 5 parts, and this is coated on the surface of the waterproof coating layer using a roll coater.
A mixture layer was formed by coating to a thickness of mm. The five metal compounds blended into the waterproof coating layer are copper sulfate, zinc chloride, aluminum sulfate, aluminum chloride, and ferric chloride. Under similar conditions, a base material on which a waterproof coating layer was formed without mixing any metal compounds was also prepared and used for comparison. A 1:3 mortar was applied to a thickness of 5 mm on the surfaces of the base material according to the present invention and the comparison material thus obtained, and after curing and hardening, the discoloration of the mixture layer surface and the adhesion of the mortar were observed and compared. did. The results are shown in Table 2.

[Table] From the results shown in Table 2, in the comparative material (prior art) in which no metal compound was added to the waterproof coating layer, some discoloration was observed on the surface of the mixture layer formed thereon. In addition, the adhesion with the overcoating mortar was not sufficient, whereas the products according to the present invention did not discolor and had significantly improved adhesion with the mortar. In the case of the present invention, this means that the wood extract component that is about to be eluted through the waterproof coating layer is bound to the metal compound mixed into the waterproof coating layer.
It was determined that this was because the influence of curing inhibition on the mixture layer was eliminated and sufficient curing was achieved. <Effects of the Invention> According to the present invention as described above, extracted components such as cellulose, lignin, tannin, and sugars in the wooden substrate of the building base material are stabilized by combining with the metal compound added to the waterproof coating layer. It forms a highly insoluble complex, and its elution to the surface of the waterproof coating layer is suppressed. Therefore, it is possible to eliminate the influence of the wood extract component on the curing of the hydraulic binder in the mixture layer, and a construction base material with high adhesion strength can be obtained. Furthermore, the mortar applied to the mixture layer after construction on a wall surface or the like does not lift or peel off, and the applied mortar does not change color due to discoloration of the mixture layer.

Claims (1)

[Claims] 1. A wooden substrate, a waterproof coating formed on the surface of the wooden substrate made of synthetic resin, latex, or bituminous material, and a hydraulic binder and synthetic resin or 1. A building material comprising a mixture layer containing latex or a bituminous material and optional aggregate, characterized in that a metal compound is further mixed into the waterproof coating. 2. Claim 1, wherein the metal compound is composed of one or more substances selected from sulfides, chlorides, and hydroxides of iron, copper, zinc, lead, or aluminum. Architectural base material as described in Section.