JPH0337630B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Fields] The present invention is applicable to areas that require waterproofing inside and outside buildings such as rooftops, balconies, bathrooms, and washrooms, as well as various tanks such as water tanks, pools, water channels, sewage treatment tanks, and silos. Regarding waterproofing construction methods. [Conventional technology] Conventionally, waterproofing has been applied to areas that require waterproofing inside and outside buildings such as rooftops, balconies, bathrooms, washrooms, etc., and various tanks such as water tanks, pools, water channels, sewage treatment tanks, and silos. Methods have been by applying asphalt, pasting rubber sheets, or urethane coatings. [Problems to be solved by the invention] However, in the waterproofing construction method using asphalt, the asphalt must be melted at the waterproofing construction site, and therefore equipment for asphalt melting is required at the construction site, and one coating process requires asphalt melting equipment. Since the coating can only be applied to a thickness of about 2 mm at most, it was necessary to apply 7 to 8 coats to obtain the desired thickness. Therefore, the workability is very poor.
Moreover, the applied asphalt layer softened as the temperature rose, causing various problems in terms of performance, such as stickiness and unevenness. In the waterproofing construction method by pasting rubber sheets, so-called unevenness adjustment is performed with cement slag to adjust the unevenness of the base surface, and this takes a long time to dry, and if drying is insufficient, the rubber sheet will not adhere properly. This causes the rubber sheet to peel off, and since the rubber sheet is directly exposed to sunlight and rain, the rubber deteriorates easily, and the slag used for unevenness adjustment is not waterproof. The disadvantage was that it gave a hard feel to the top, offsetting the elasticity provided by the rubber sheet. In addition, with the waterproof construction method using urethane coating, the desired thickness cannot be obtained with one coating, so it is necessary to apply three or four coats, and if the base is not completely dry, There was a problem that the urethane coating did not adhere and peeled off, and the urethane coating had poor weather resistance, and that contact with water caused hydrolysis and the coating thinned. [Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention provides a waterproof undercoat layer made of a composition containing an acrylic polymer, cement, short fibers, and aggregate on a base that requires waterproofing. a composition formed by forming a waterproof undercoat layer by adhering it to a rubber sheet with a pressure-sensitive adhesive, and containing an acrylic polymer, cement, silica powder or Cerben, short fibers, and aggregate on the rubber sheet. The present invention provides a waterproofing construction method that can form a waterproofing layer that is easy to work with and has excellent performance by forming a topcoat layer consisting of the following. In the present invention, the waterproof undercoat layer is made of a composition containing an acrylic polymer, cement, short fibers, and aggregate, exhibits waterproof properties, serves as the base layer of the rubber sheet, and can be used when the base surface is uneven. It works as an unevenness adjusting agent. The acrylic polymer in the composition constituting the waterproof undercoat layer is the driving force that creates strong adhesion with the concrete or mortar that constitutes the base. If there is too little of this acrylic polymer in the product, the adhesion to the underlying concrete or mortar will decrease, as well as the flexibility.On the other hand, if there is too much, only the surface layer will harden, causing damage to the inside of the waterproof undercoat layer. Since curing will not proceed, the amount used should be 25 to 25% in the composition.
It is preferable to set it to 45% (weight %, the same applies hereinafter).
As described later, when preparing the above composition,
This acrylic polymer is used in the form of an emulsion. Among these acrylic polymers in an emulsion state, an emulsion polymer having cationic particle charges called an acrylic cationic emulsion polymer is preferably used. This acrylic cationic emulsion polymer is obtained by emulsion polymerization, and includes unsaturated carboxylic acids such as acrylic acid and methacrylic acid, methyl acrylate, ethyl acrylate,
Homopolymers of unsaturated carboxylic acid esters such as butyl acrylate, octyl acrylate, and methyl methacrylate or copolymers of these monomers, and these polymers are secondary or tertiary amine salts, or quaternary ammonium salts. It is modified into a cationic form by salt, etc. A suitable commercially available example of such an acrylic cationic emulsion polymer is commercially available from Dainippon Ink and Chemicals Co., Ltd. under the trade name VONCOAT SFC-60, which has a resin solid content of approximately
50% emulsion and the same product name VONCOAT
(Boncourt) SFC-65, a commercially available emulsion with a resin solid content concentration of approximately 60%. Since the acrylic polymer is used in the form of an emulsion, the composition is obtained as a paste containing moisture during preparation, but the waterproof undercoat layer is obtained by applying the paste on the base, drying,
It is obtained by curing and fulfills its role, so in the present invention, the composition constituting the waterproof undercoat layer refers to the composition after drying, and the acrylic cationic emulsion in the composition The amount of acrylic polymer such as polymer is indicated by the resin solid content. In the present invention, the cement in the composition constituting the waterproof undercoat layer is useful for adhesion to the cement in the concrete layer or mortar layer, and also absorbs moisture in the resin emulsion when forming the waterproof undercoat layer. It hardens and allows the composition paste to be applied thickly to the base. If there is too little of this cement in the composition, the above-mentioned effect will not be fully exerted, and on the other hand, if there is too much, it will reduce flexibility and elasticity. Since the properties are reduced, the amount used is 10~
Preferably it is 25%. As the cement, for example, Portland cement, alumina cement, etc. are used. Short fibers are useful for preventing cracks caused by shrinkage when cement hardens; if there are too few short fibers in the composition, cracks will occur and the waterproofing effect will be reduced, while if there are too many, the viscosity of the composition paste will decrease. If the amount becomes too high, the workability during formation of the waterproof undercoat layer will deteriorate, so it is preferably 2 to 15% in the composition. Examples of such short fibers include inorganic short fibers such as asbestos fibers and glass fibers, and organic short fibers such as pulp fibers. In addition, aggregate is useful for roughening the surface of the waterproof undercoat layer and improving adhesion with the rubber sheet using pressure-sensitive adhesives. It is preferable to use 25 to 45% of the composition since surface roughening will be reduced, and too much content will result in lack of flexibility. Such aggregates include, for example, silica sand, silica stone powder, pumice, volcanic sand, etc., which have been sieved, natural lightweight aggregates such as those which have been crushed and sieved, perlite, and vermiculite. Artificial aggregates such as Ulite are used. In order to form the waterproof undercoat layer in the present invention, it is preferable to perform, for example, as shown below. That is, an acrylic polymer emulsion is prepared, a mixture containing cement, short fibers, and aggregate is prepared as an admixture to the resin emulsion,
The resin emulsion is added dropwise to the admixture and stirred to mix uniformly, and the composition is applied onto the base and dried. When preparing the resin emulsion, a thickener such as xylene or an antifoaming agent is added, and when preparing an admixture, a lubricant such as calcium stearate or a powdered antifoaming agent is added. It is preferable to keep it. In addition, in the present invention, the composition constituting the waterproof undercoat layer may contain an acrylic polymer, cement, short fibers, and aggregate as essential components, and may also contain an antifoaming agent, a lubricant, and the like as described above. Of course, it may contain some thickener, hydrating agent, etc. The thickness of the waterproof undercoat layer is preferably about 0.5 to 2.5 mm because if it is too thin, the waterproof effect cannot be sufficiently exhibited, and if it is too thick, there will be a large economic loss. Drying may be done by natural drying or by forced drying such as by blowing hot air. In the case of natural drying, the thickness described above can be dry to the touch in a drying period of about 1 to 24 hours, and drying is faster than cement slag (which takes 3 to 4 days to dry). As is clear from the above description, the base does not necessarily need to be in a dry state when forming the waterproof undercoat layer. Examples of the base on which the waterproof undercoat layer is formed are areas that require waterproofing inside and outside buildings such as rooftops, balconies, bathrooms, and washrooms, as well as water tanks, pools, water conduits, sewage treatment tanks, and silos. These include various tanks, etc., and the base of these is usually made of concrete, mortar, etc. As the rubber sheet, sheets made of butyl rubber, chloroprene rubber, or the like are preferably used because of their excellent waterproof properties. The rubber sheet is used to add elasticity to the waterproof layer that is formed, and the thickness is 0.3 to 1.0 mm in consideration of the balance between elasticity and economic efficiency.
A moderate amount is preferred. As the pressure-sensitive adhesive for adhering the rubber sheet to the waterproof undercoat layer, rubber-based and acrylic-based pressure-sensitive adhesives are used, and acrylic-based pressure sensitive adhesives are particularly preferred. In order to improve workability, this pressure-sensitive adhesive is applied to one side of the rubber sheet in advance, and a release paper is applied to the side to which the adhesive is applied, and the pressure-sensitive adhesive is applied to the rubber sheet. It is preferable to wind the rubber sheet into a spiral shape together with a release paper, and at the construction site unwind the rubber sheet and peel off the release paper while pressing the rubber sheet onto the waterproof undercoat layer from the pressure-sensitive adhesive layer side.
The amount of pressure-sensitive adhesive applied is 80 to 150 g/m ²
is preferred. Although the composition constituting the top coat layer is almost the same in terms of composition as the composition constituting the waterproof base layer,
In particular, the composition constituting this top coat layer contains silica powder or Cerbene (ceramic powder) to impart wear resistance. This top coat layer is also waterproof and serves as a waterproof layer, as well as to prevent the rubber sheet from being directly exposed to the surface.
It is preferable to form the rubber sheet so as to cover not only the top of the rubber sheet but also the entire side thereof. In addition, since this top coat layer is the outermost layer, pigments such as chromium oxide (green), soil (yellow), Bengara (brick red), and carbon (used for gray toning) are included in the composition. It is preferable to contain it so that it can play a role as a decorative layer. In the composition constituting this top coat, the acrylic polymer acts as an adhesive with the rubber sheet,
It also forms a film and exhibits waterproof properties. In addition to this acrylic polymer, cement, short fibers, and aggregates are also used in the same manner as in the case of the waterproof undercoat layer, and the roles of cement, short fibers, and aggregates are also the same as in the waterproof undercoat layer. This is almost the same as in the case of .
As mentioned above, silica powder and Selvene are useful for imparting wear resistance, and if there is too little of these silica powder or Selvene in the composition, the effect of imparting wear resistance will not be sufficient, and if too much, the waterproof effect and elasticity will be insufficient. It is preferable to make it 10 to 25% in the composition because it reduces the properties. The composition preferably contains 20 to 40% of acrylic polymer, 15 to 25% of cement, 0.5 to 5% of short fibers, and 12 to 30% of aggregate. Further, when a pigment is contained, it is preferable that the pigment is contained in the composition in an amount of 1 to 6%. In preparing the composition paste for the top coat layer, prepare a resin emulsion and an admixture thereto in the same manner as in the case of the composition paste for the waterproof undercoat layer, and add resin to the admixture. A method of dropping the emulsion and mixing it is preferred. In addition, when preparing resin emulsions, thickeners and antifoaming agents are added.
When preparing the admixture, a lubricant, a powdered antifoaming agent, etc. may be added. As the acrylic polymer, an acrylic cationic emulsion is preferably used as in the case of the waterproof undercoat layer. The overcoat layer is formed by applying a composition paste onto a rubber sheet and drying it, and drying can be performed by either natural drying or forced drying as in the case of the waterproof undercoat layer. The thickness of the top coat layer is preferably about 2 to 4 mm. [Example] Next, the present invention will be explained in more detail with reference to Examples. Preparation of composition paste for waterproof undercoat layer A resin emulsion and admixture having the following composition were prepared. Resin emulsion (parts by weight) Acrylic cationic emulsion polymer (VONCOAT SFC-60, resin solids concentration 50%) 100.0 Resin thickener 1.5 Silicone antifoaming agent 0.5 Admixture (parts by weight) Portland cement 36.0 Pulp Fiber (fiber length 0.5 mm) 2.5 Asbestos fiber (fiber length 3 mm) 1.5 Aluminum silicate 4.5 Calcium stearate 0.9 Polyvinyl alcohol 0.4 Silica sand No. 6 40.0 Silica sand No. 7 15.0 Mineral oil defoaming agent 0.3 Admixture with the above composition 100 150 parts by weight of the resin emulsion was added dropwise to the parts by weight and stirred for 10 minutes to mix uniformly to prepare a composition paste for a waterproof undercoat layer. Preparation of composition paste for top coat layer A resin emulsion and admixture having the following composition were prepared. Resin emulsion (parts by weight) Acrylic cationic emulsion polymer (VONCOAT SFC-65, resin solids concentration 60%) 100.0 Xylene 3.5 Silicone antifoaming agent 0.5 Admixture (parts by weight) Alumina cement 33.0 Asbestos fiber (fiber length) 2.5 Calcium stearate 0.5 Polyvinyl alcohol 0.4 Cerben (0.5 mm or less) 23.0 Silica powder 14.0 Silica sand No. 6 9.0 Silica sand No. 7 20.0 Mineral oil antifoaming agent 0.3 Chromium oxide 4.3 Add the above to 100 parts by weight of the admixture of the above composition. 100 parts by weight of the resin emulsion was added dropwise and stirred for 10 minutes to mix uniformly to prepare a composition paste for the top coat layer. When waterproofing the roof of a building using the composition paste for the waterproof undercoat layer, the composition paste for the topcoat layer, and the butyl rubber sheet prepared as described above, it is necessary to prepare the base layer for the waterproof undercoat layer in advance. The adhesion to and water permeability of the waterproof undercoat layer, the adhesion between the waterproof undercoat layer and the rubber sheet, and the adhesion between the rubber sheet and the top coat layer were investigated. The test methods and test results are shown below. Adhesion test between waterproof undercoat layer and base according to JIS A 6909, Portland cement,
A mixture of sand and water in a weight ratio of 1:3:1.6 was applied to a 10cm square area to a thickness of 20mm.
℃ and a relative humidity of 65% for 7 days as a base, and the waterproof undercoat layer composition paste prepared as described above was applied to this to a dry film thickness of 1.5 mm, After air drying (curing) for 28 days, adhesive strength was measured according to JIS A 6909.
The results are shown in Table 1. After drying, the adhesive strength was measured in the same manner after being immersed in water for 7 days. The results are shown in Table 1.

[Table] Water permeability of waterproof undercoat layer The composition paste for waterproof undercoat layer prepared as above was applied to the same base as above at a rate of 1.5 kg/ ^m2 , and after air drying for 28 days. According to JIS A 1404, water pressure of 3 kg/cm ² was applied for 24 hours to measure water permeability. The results are shown in Table 2 in comparison with those without coating.

[Table] Adhesiveness between waterproof undercoat layer and rubber sheet The above composition paste for waterproof undercoat layer was applied on the same base as above in the same manner as above, and dried to form a 1.5 mm thick layer. A 0.8 mm thick rubber sheet coated with 100 g/ ^m2 of acrylic pressure-sensitive adhesive on one side is pressed onto the waterproof undercoat layer, and after 24 hours, JIS
When an adhesion test was conducted according to A 6909,
Peeling occurred at 3.5Kg/cm ² . Adhesion between rubber sheet and top coat layer The above composition paste for top coat layer was applied onto a butyl rubber sheet with a thickness of 0.8 mm so that the dry film thickness was 3.0 mm, and air-dried (cured) for 28 days. After that,
Adhesive strength was measured according to JIS A 6909. The results are shown in Table 3. Furthermore, after the above drying, the adhesive strength was similarly measured for those immersed in water for 7 days. The results are shown in Table 3.

〔Effect of the invention〕

As explained above, according to the present invention, waterproofing can be carried out with good workability, and the formed waterproof layer has excellent both waterproofness and walking feel.

Claims (1)

[Claims] 1. A waterproof undercoat layer made of a composition containing an acrylic polymer, cement, short fibers, and aggregate is formed on a base, and a rubber sheet is attached to the waterproof undercoat layer using a pressure-sensitive adhesive. 1. A waterproofing construction method comprising: adhering and pasting the rubber sheet, and forming an overcoat layer made of a composition containing an acrylic polymer, cement, silica powder or Cerben, short fibers, and aggregate on the rubber sheet. 2. The waterproofing method according to claim 1, wherein the composition forming the top coat layer contains a pigment, and the top coat layer serves as a decorative layer.