Waterproofing method and waterproofing structure for wood-based substrates

Abstract

To provide means for contributing to a formation of a waterproof layer more suitable to a woody substrate.SOLUTION: A waterproofing method comprises a process of applying a primer with cement to be applied on a surface of a woody substrate and forming an undercoat layer and a process of applying an urea-based resin on a surface of the undercoat layer and forming a waterproof layer. It is preferable that the primer with cement has a weight ratio of cement to the one-liquid urethane-based primer of 1 / 3 or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a waterproofing method and a waterproofing structure for waterproofing wood-based substrates used in various buildings. [Background technology]

[0002] The following patent documents disclose techniques for waterproofing the framework of a building. Patent Document 1 discloses a technology for waterproofing floors, in which a blister prevention layer made of a base adjustment material whose main components are an epoxy resin emulsion and cement premix, a water-based epoxy resin primer layer, a waterproof layer, and a paving layer are applied in that order to a concrete base. Patent Document 2 discloses an invention for a waterproofing method for underground structures in which a primer containing a filler is applied to a waterproof base made of an inorganic material, and then a liquid resin material is applied to form a waterproof layer made of a thermosetting resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4446364 [Patent Document 2] JP 2013-2249 A Summary of the Invention [Problem to be solved by the invention]

[0004] When attempting to form a waterproof layer made of urea-based resin on wood-based substrates used in various buildings using the above-mentioned waterproofing technology, at least one of the problems described below has arisen. (1) Wood-based bases are prone to absorbing moisture from rain, etc., so if a normal urethane primer is used, the primer may react with the moisture, resulting in insufficient adhesion between the wood-based base and the primer layer. (2) Because the applied primer easily penetrates into wood-based bases, a primer layer of sufficient thickness may not be formed on the surface of the base.

[0005] Therefore, one of the objects of the present invention is to provide a means that contributes to the formation of a more suitable waterproof layer for wood-based substrates. [Means for solving the problem]

[0006] The first invention of the present application, which has been made to solve the above problems, is as follows: Water-containing materials that make up the foundation material of buildings A waterproofing method for wood-based substrates, comprising: The above The method includes a step of applying a primer containing cement to the surface of a wood-based base to form an undercoat layer, and a step of applying a urea-based resin to the surface of the undercoat layer to form a waterproof layer. The primer containing cement is a mixture of a one-liquid urethane primer and cement. It is characterized by the above. The second invention of the present application is the first invention, One-component urethane system The weight ratio of the cement to the primer is 1 / 3 or more. The third invention of the present application is the first or second invention, The one-component urethane primer is mixed with the cement on-site. It is characterized by: The fourth invention of the present application is Water-containing materials that make up the foundation material of buildings A waterproof structure for wood-based substrates, The above containing moisture Apply to the surface of wood-based substrates. It is a mixture of a one-component urethane primer and cement. The concrete structure is characterized by having an undercoat layer made of a primer containing cement, and a waterproof layer made of a urea-based resin applied to the surface of the undercoat layer. Ma Furthermore, the first aspect of this application 5 The invention relates to the fourth invention. Clearly Leave, before Note One-component urethane system The weight ratio of the cement to the primer is 1 / 3 or more. Effect of the Invention

[0007] According to the present invention, at least one of the following effects can be obtained. (1) The cement mixed into the primer absorbs moisture generated by the wood-based base, suppressing the reaction between the primer and water and preventing the primer from being repelled by the surface of the wood-based base. As a result, the decrease in adhesive strength between the wood-based base and the primer layer can be suppressed. (2) Because the cement holds the primer in place, a sufficiently thick undercoat layer can be formed on the surface of the wood-based substrate. (3) The addition of cement colors the undercoat layer, making it easier to see where the primer has been applied and how much has been applied, improving workability. (4) The viscosity of the primer increases, making it easier to correct unevenness on the surface of the undercoat layer. (5) The addition of cement increases the surface area of ​​the primer layer, thereby shortening the drying time. (6) The cement mixed into the primer penetrates into the waterproofing material, strengthening the adhesive strength between the undercoat layer and the waterproofing layer. (7) The cement mixed into the primer penetrates into the joints of wood-based base materials, preventing the occurrence of pinholes. (8) When a one-component urethane-based primer is used, it is easier to handle on site than when a two-component epoxy-based primer is used, as it requires less effort such as stirring. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The details of the configuration according to the present invention and experimental examples are described below. EXAMPLES

[0009] <1> Overall Configuration The waterproof structure according to the present invention is configured to have at least an undercoat layer provided on the surface of a wood-based base, and a waterproof layer provided on the surface of the undercoat layer. The wood-based substrate is the base material to which waterproofing is applied. Wood-based substrates include wooden plywood and the like used as substrate materials for roofs, rooftops, floors, walls, etc., and there are no particular limitations on the type of wood. In the present invention, the waterproof material used to form the waterproof layer is a urea-based resin. Furthermore, a topcoat layer may be provided on the surface of the waterproof layer, if necessary. The undercoat layer will be described in detail below.

[0010] <2> Undercoat layer The undercoat layer is a layer that is applied to a wood-based base prior to the formation of a waterproof layer to improve the workability and adhesion of the waterproof layer formation work. In this embodiment, it is preferable to use a one-liquid urethane-based primer as the primer used for the undercoat layer. The reason for this is that one-component urethane-based primers are easier to handle when performing on-site stirring operations and cement mixing operations, compared to two-component epoxy-based primers.

[0011] <2.1> Cement mixing The primer used in the present invention contains added cement. In the present invention, the mixing ratio of cement is preferably at least 1 / 3 by weight relative to the primer.

[0012] <2.2> Timing of mixing cement The timing of adding cement to the primer can be either on-site mixing (external addition) or prior addition (internal addition). The advantages of each addition method are as follows:

[0013] <2.2.1> On-site mixing (external addition) If the on-site mixing method is used, the primer can be applied immediately after mixing, reducing the risk of the cement separating and settling in the primer container. It is also beneficial in that it allows for flexible adjustment of the amount of cement to be mixed, for example by increasing the amount of cement mixed in cases where the moisture content of the wood-based base is higher than initially expected due to sudden rainfall or other reasons.

[0014] <2.2.2> Premixing (internal addition) The method of mixing cement into the primer in advance is advantageous in that it makes it easier to control the quality of the mixture, such as the amount of cement, and also eliminates the need for on-site mixing.

[0015] <2.3> Addition of dispersants / anti-settling agents Furthermore, a dispersant or anti-settling agent may be appropriately added to the primer, if necessary, in order to further suppress separation and settling of the cement within the primer.

[0016] <3> Experimental Example Next, the results of various performance tests will be described.

[0017] <3.1> Performance test 1 (water-stopping performance with cement) A comparative experiment was conducted on the waterproofing performance of the primer by changing various primer conditions. The test conditions and methods are as follows:

[0018] <3.1.1> Test conditions [Type of primer] (1) None (2) One-component urethane primer (product name: "AQ Primer U" manufactured by Nippon Aqua Co., Ltd.) (3) Two-component epoxy primer (product name: "AQ Primer EP" manufactured by Nippon Aqua Co., Ltd.)

[0019] [Cement Mixture Ratio] (Ordinary Portland Cement: Commercially Available) (1) None (2) 5:1 (weight ratio of cement to primer = 1 / 5) (3) 3:1 (weight ratio of cement to primer = 1 / 3) (4) 1:1 (weight ratio of cement to primer = 1 / 1)

[0020] [Amount of primer applied] (1) None (2) 0.1 [kg / m2] (3) 0.2 [kg / m2] (4) 0.3 [kg / m2]

[0021] <3.1.2> Test method Step 1: Apply primers of various conditions to the test specimen (a 200mm square calcium silicate board) and allow to dry overnight. Step 2: Surround the four sides of the test specimen with tape to create a recess measuring 150 mm square. Step 3: Pour water into the recess to create a puddle. (Pour 45g (equivalent to 2kg / m2)) Step 4: After 1 hour, remove excess water. (If all water is absorbed within 1 hour, pour in another 22.5g and leave for 1 hour.) Step 5: Calculate the weight of water that has penetrated the structure.

[0022] <3.1.3> Test results The test results are shown in Table 1. [Table 1] TIFF0007628934000001.tif189150

[0023] The following points become clear from Table 1 above. (1) As the amount of cement mixed with the primer increases within a certain range, the water-stopping performance improves. (2) Epoxy primers have a certain degree of water-stopping effect even without the addition of cement. (3) When used with calcium silicate board as a base, epoxy-based primers have better waterproofing performance than urethane-based primers.

[0024] <3.2> Performance test 2 (test specimen evaluation on a base made of lauan plywood) Next, a wood-based base (lauan plywood) was adjusted to a specified moisture content (9% moisture content on the surface, 15% with a spray bottle) and test specimens were then coated with primer, waterproofing agent, top coat, and exposed to sunlight in that order while changing the primer conditions. The test specimens were then evaluated for ease of application, presence or absence of pinholes, presence or absence of blisters, and adhesive strength. The adhesive strength was evaluated by cutting a cut in the test specimen with a cutter, and then manually peeling it off, based on the force exerted, and the percentage of the base material that was adhered to the peeled waterproofing layer.

[0025] [Raw materials for primer] (1) One-component urethane primer (product name "AQU": manufactured by Japan Aqua Co., Ltd.) (2) One-component urethane primer (product name: "Sun PC-F" manufactured by AGC Polymer Construction Materials Co., Ltd.) (3) To the above (2), 15% pigment and 1% amine-based curing accelerator have been added. (4) To the above (2), 15% pigment and 2% amine-based curing accelerator have been added. (5) Cement (commercially available ordinary Portland cement) (The weight ratio of cement to primer was 1 / 3.) (6) Two-component epoxy primer (product name "AQEP": manufactured by Japan Aqua Co., Ltd.) In addition, the surface of the undercoat layer was roughened using a commercially available disc grinder (#120 grinding wheel) in the experimental examples.

[0026] [Waterproof material] Urea-based resin waterproofing material (product name "AQ3000A / B": manufactured by Japan Aqua Co., Ltd.)

[0027] [Top coat] Top coat for waterproofing (product name "AQ Top F": manufactured by Dick Proofing Co., Ltd.)

[0028] <3.2.1> Test results The test results are shown in Table 2. [Table 2] TIFF0007628934000002.tif98150

[0029] The following points become clear from Table 2 above. (1) Without primer (test piece 1), the adhesive strength was only moderate. (2) Adding cement to the primer shortens the drying time and improves application properties and adhesive strength. (3) When the surface of the primer layer was roughened (specimen 9), some improvement was observed in the number of pinholes and adhesive strength, but the effect was limited compared to when cement was added. (4) Considering the price and practicality, specimen 4 (an example of a urethane primer mixed with cement) is the most suitable.

[0030] <3.3> Performance test 3 (test specimen evaluation on softwood plywood substrate) A wood-based base (coniferous plywood) was adjusted to a specified moisture content (6% on the surface, 9% with a spray bottle) and test specimens were coated with primer, waterproofing agent, top coat, and exposed to sunlight in that order, while changing the primer.The test specimens were then evaluated for ease of application, presence or absence of pinholes, presence or absence of blisters, and adhesive strength. The adhesive strength was evaluated by cutting a cut in the test specimen with a cutter, and then manually peeling it off, based on the force exerted, and the percentage of the base material that was adhered to the peeled waterproofing layer.

[0031] [Raw materials for primer] (1) One-component urethane primer (product name "AQU": manufactured by Japan Aqua Co., Ltd.) (2) One-component urethane primer (product name: "Sun PC-F" manufactured by AGC Polymer Construction Materials Co., Ltd.) (3) To the above (2), 15% pigment and 1% amine-based curing accelerator have been added. (4) To the above (2), 15% pigment and 2% amine-based curing accelerator have been added. (5) Cement (commercially available ordinary Portland cement) (The weight ratio of cement to primer was 1 / 3.) (6) Two-component epoxy primer (product name "AQEP": manufactured by Japan Aqua Co., Ltd.) In addition, the surface of the undercoat layer was roughened using a commercially available disc grinder (#120 grinding wheel) in the experimental examples.

[0032] [Waterproof material] Urea-based resin waterproofing material (product name "AQ3000A / B": manufactured by Japan Aqua Co., Ltd.)

[0033] [Top coat] Top coat for waterproofing (product name "AQ Top F": manufactured by Dick Proofing Co., Ltd.)

[0034] <3.3.1> Test results The test results are shown in Table 3. [Table 3] TIFF0007628934000003.tif98150

[0035] The following points become clear from Table 3 above. (1) The overall tendency is the same as in Performance Test 2 (lauan plywood) above. (2) The adhesive strength is stronger than that of Performance Test 2 (lauan plywood) above.

Claims

1. A waterproofing method for a wood-based substrate containing moisture that constitutes a substrate for a building, comprising: The moisture content (surface) of the wood-based substrate is 9% or more; A step of applying a primer containing cement to the surface of the wood-based base to form an undercoat layer; A step of applying a urea-based resin to a surface of the undercoat layer to form a waterproof layer; having The primer containing cement is made of a mixture of a one-liquid urethane primer and cement, and the weight ratio of the cement to the one-liquid urethane primer is 1 / 3 or more. Waterproofing method for wood-based substrates.

2. The one-liquid urethane primer and the cement are mixed on-site. A waterproofing method for wood-based substrates according to claim 1.

3. A waterproof structure for a wood-based substrate containing moisture that constitutes the substrate of a building, a primer layer including a cement-containing primer, the primer layer being a mixture of a one-liquid urethane primer and cement, the primer being applied to the surface of the wood-based base having a moisture content (surface) of 9% or more; A waterproof layer made of a urea-based resin applied to the surface of the undercoat layer; having The weight ratio of the cement to the one-liquid urethane primer is 1 / 3 or more. Waterproof structure for wood-based substrates.

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