JPS5841103B2 - Waterproofing method for plate-shaped objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plate-like material used for an exterior wall base, particularly a JISA590
The present invention relates to a method for waterproofing plate-like materials such as sheathing insulation fiberboards as specified in Section 5.

Compared to conventionally used sheathing insulation fiberboards and insulation fiberboards, asphalt is added internally, which greatly improves water absorption performance, but it is completely inadequate as an exterior wall base material. However, expansion and contraction due to water absorption is observed, and after the bonding process, there is a risk that the board will become wavy due to expansion and contraction, or that the moisture contained in the mortar will be absorbed into the board, causing poor hardening of the mortar.

Methods to improve this water absorption include increasing the amount of asphalt added to the board, or applying asphalt to the board surface. However, in the latter case, where asphalt is applied to the surface, blocking (adjacent boards sticking together) is disadvantageous.
Since this tends to occur, it is necessary to infiltrate asphalt into the board, which requires high-temperature treatment or treatment with a solvent, resulting in poor workability and labor safety problems.

The present invention provides a method for waterproofing plate-like objects, which aims to eliminate such drawbacks, improve the waterproof performance of sheathing insulation fiberboards, and prevent the blocking phenomenon that occurs during stacking of boards. It is.

That is, the present invention applies an asphalt emulsion containing a water repellent, which is made by adding an asphalt emulsion and a suitable water repellent, to the surface of a plate-like object, and then heat-treats the emulsion to dry and heat the emulsion to coat the surface of the plate-like object. It is characterized by forming an asphalt layer and a water repellent layer.

In the method of the present invention, the asphalt has a softening point of 9
An asphalt emulsion is used, which is made of asphalt having a high softening point such as 10 to 20 blown asphalt at 0° C. or higher, or an asphalt compound adjusted to have a high softening point by mixing oil or fat into asphalt.

The reason for using such an asphalt emulsion is that if asphalt with a low softening point is used, it will be highly adhesive even at room temperature, so even if a water repellent is used together, the water repellent will tend to be buried in the asphalt. This is because blocking is likely to occur, and when the softening point is low, it takes a long time to lower the temperature below the softening point after heat treatment, resulting in poor workability.

In addition, in order to improve waterproofness without reducing heat insulation properties, it is desirable to form a film without the asphalt seeping through, but this would cause blocking, so it is necessary to apply a water repellent agent to the surface of the asphalt layer. This prevents blocking.

Paraffin, wax, silicone, and petroleum resin-based water repellents can be used as water repellents without any particular problems.After applying an asphalt emulsion containing such a water repellent to the surface or both front and back surfaces of a plate-like object, dry heating is performed. First, a layer containing a mixture of emulsion particles and water repellent is obtained due to the evaporation of water during drying, and then the emulsion is destroyed by heating to form an asphalt layer, and the water repellent is pushed out to the surface layer. A layer of water repellent is formed on top of the asphalt layer.

For this reason, even if asphalt alone causes pinholes due to insufficient fusion, the pinholes are filled with water repellent that is about to be pushed out to the surface layer, making it better than asphalt alone. Provides waterproof properties.

Such an emulsion mixed with a water repellent agent influences the surface quality of the plate-like object depending on the amount of application.

In other words, from the perspective of waterproofing performance of the exterior wall base material, asphalt needs to have a solid content of 20g/rIL2 or more, but 100g/rIL2 or more is required in solid content.
If the coating is applied in excess of S'/m2, the film becomes too thick and has poor moisture permeation resistance, resulting in a loss of breathability as a building material and a tendency for dew condensation to occur within the wall.

In this way, as the amount of water repellent increases, the amount of moisture permeability decreases,
Since breathing performance is lost, it is preferable that the amount of water repellent-containing emulsion applied to the surface of the plate is in the range of 20 to 100 g/m2, and the amount of water repellent is 3 g/m2 based on the total solid content.
The amount added is preferably 0 to 50% by weight.

Furthermore, if the amount of water repellent added is large, the surface of the plate-like material becomes slippery, making it difficult to deposit and transport it, so from this point of view, it is better not to add too much.

Next, examples of the present invention and comparative examples will be shown.

Example: On the surface of a sheathing insulation fiberboard, 40 g of a water repellent-added asphalt emulsion prepared by mixing an emulsion of blown asphalt with a softening point of 95°C and a wax water repellent in a solid ratio of 80:20 was applied. /m2, and then dried and heated in a hot air circulation dryer at 180°C for 450 seconds to form an asphalt layer and a water repellent layer on the board surface.

Comparative Example The asphalt emulsion and wax water repellent used in the above example were each applied individually to the surface of the sheathing insulation fiberboard at a solid content of 40 g/1.
A board was coated at a ratio of 7L2 and dried and heated under the same conditions as in the previous example to form only an asphalt layer on the surface (this is referred to as Comparative Example 1), and a board with only a water repellent layer formed on the surface. A board (this is Comparative Example 2) was created.

The water absorption, moisture permeability, and blocking properties of the boards obtained in the above Examples and Comparative Examples 1 and 2 are shown below.

In the above table, the water absorption amount is obtained by absorbing water from one side of a 300 mm square board for 24 hours, and the moisture permeation amount is 20 Qii<
These are the values when using a square board at 30° C., 90% RH, and 40 hours.

As described above, even in the case of a board provided with only an asphalt layer, a decrease in water absorption can be seen, but it is still not sufficient, but when a water repellent is added at the same coating amount, the water absorption is greatly improved.

However, when a water repellent is applied alone to the board surface, almost no effect is observed.

In addition, by applying asphalt containing a water repellent agent compared to an untreated board, the amount of water absorption can be improved to less than %.Moreover, the amount of water absorption does not decrease, but the amount of moisture permeation does not decrease. Even when used as a base for an external wall, it hardly causes condensation inside the wall, and can further prevent blocking.

As described above, the present invention applies an asphalt emulsion containing an asphalt emulsion and a suitable water repellent to one surface of a plate-like object, and then dries and heats the applied emulsion to form a plate-like object. This relates to a waterproofing method for plate-like objects, which is characterized by forming an asphalt layer and a water-repellent layer on the surface of the object, since the asphalt forms a film on the surface without penetrating into the inside of the object. It does not reduce the insulation performance of the plate-like material, and compared to surface treatment with asphalt alone, there is no need for asphalt penetration treatment such as high-temperature press-in means, and after application, only drying and heating is required. Not only is it easy to do this, but it also has a sufficient waterproofing effect and allows a suitable level of breathing to remain in the plate-like material, and when used as a base for an exterior wall, it can prevent the occurrence of dew condensation.

In addition, even when a large number of plate-shaped articles obtained by the method of the present invention are stacked together, blocking phenomenon between the plate-shaped articles can be prevented, and since the waterproofing effect is excellent, even when used as an exterior wall base and coated with mortar, It does not cause poor curing of the mortar due to absorption of moisture contained in the mortar, and has low adhesion to the mortar, which prevents cracks in the mortar due to expansion and contraction due to moisture absorption etc. of the board. It is.

Claims (1)

[Claims] 1. An asphalt emulsion containing a water repellent, which is an asphalt emulsion and an appropriate water repellent added thereto, is applied to one surface of a plate-like object, and then the applied emulsion is dried and heated to form a plate-like object. A waterproofing method for a plate-like object, which comprises forming an asphalt layer and a water repellent layer on the surface of the object. 2. The method for waterproofing a plate-shaped article according to claim 1, wherein the asphalt emulsion is made of high softening point asphalt or asphalt adjusted to have a high softening point. 3. The method for waterproofing a plate-shaped article according to claim 1, wherein the amount of water repellent added is 50% by weight or less in terms of solid content based on the total amount of asphalt and water repellent. 4. Waterproofing of a plate-like object according to claim 1, 2, or 3, characterized in that a double layer of an asphalt layer and a water repellent layer is formed on both the front and back surfaces of the plate-like object, respectively. Processing method.