JPS6024813Y2 - roof base sheet - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a roof base sheet that does not form dew condensation and has excellent waterproof properties.

Conventionally, films made of thermoplastic resins such as polyethylene and vinyl chloride, either singly or in combination, have been used as roof base sheets, but because they have no moisture permeability, condensation occurs due to temperature differences inside and outside the house.

Therefore, a roof base sheet has been proposed in which hygroscopic paper or cloth is attached to one or both sides of this film.

However, this roof base sheet only has the function of absorbing the resulting condensation, but does not have the function of releasing moisture to the outside. Therefore, the part of the roof board that is in contact with the paper or cloth may be in a state of excessive moisture. It had the disadvantage that it was easily corroded because it was made of metal.

In addition, when roofing sheets made of thermoplastic synthetic resin film are nailed to open fields, if the nails are nailed incorrectly, holes may be left, and the areas where the nails are nailed may also gradually tear, causing problems with waterproofing. Ta.

In order to improve the above-mentioned drawbacks, the applicant first
It was proposed that a water-repellent non-woven fabric with water vapor permeability of g7' crft/hr or more can be effectively used as a roof base sheet (Utility Application No. 51-60121).

-The creator of the strength wood did not necessarily have to do 3 things to prevent condensation.
It was discovered that even if there is no water vapor permeability of mg/crl/hr or more, by adopting a specific structure, it is possible to substantially prevent various problems caused by condensation, and to provide sufficient waterproofness. This is what we came up with.

In other words, the present invention uses a hygroscopic sheet with a water repellency of 50% or more and 100%.
This is a roofing base sheet made by integrating non-woven fabrics with a bituminous material layer having fine gaps between them.

In this invention, we were able to achieve moisture vapor respiration through a mechanism in which the hygroscopic sheet temporarily absorbs moisture generated due to temperature differences inside and outside the house, and then gradually releases it to the outside through minute gaps in the bitumen layer. Moreover, by combining a nonwoven fabric with a water repellency of 50% or more but less than 100% and a bituminous material layer with minute gaps, we were able to achieve the waterproofness required for a roof base sheet without using a synthetic resin film. Because it did not use a synthetic resin film, it was possible to prevent it from tearing or leaving nail holes when nailed.

To explain the roof base sheet of the present invention based on the drawings, 1 indicates a nonwoven fabric with a water repellency of 50% or more and less than 100%;
This is a fiber made of corrosion-resistant synthetic fibers such as polyester, polypropylene, and polyamide, recycled fibers such as rayon, and natural fibers such as cotton and hemp, either alone or in a mixture, randomly or directionally accumulated. A nonwoven fabric made by bonding the fibers of the web with a latex adhesive such as NBR, SBR, or acrylic.Adhesive fibers are added to the fiber web in advance, and the adhesive fibers are used to bond the constituent fibers. Finally, J
It is obtained by impregnating or coating with a known water repellent such as silicone-based or fluorine-based water repellent so that the degree of water repellency measured by IS, L-1079A method is 50% or more and less than 100%.

If the water repellency of the nonwoven fabric is less than 50%, good waterproof properties as a roof base sheet cannot be obtained even when combined with a bituminous layer having minute gaps.

In the present invention, a nonwoven fabric with a water repellency of 70% or more is more preferable.

Although the weight of the nonwoven fabric 1 having a water repellency of 50% or more and less than 100% can be selected as appropriate, it is generally preferable to have a weight in the range of 70 to 200 g/d because it is easy to handle and lightweight.

2 indicates a hygroscopic sheet, which may be any sheet-like material that absorbs moisture; for example, paper, knitted fabrics or non-woven fabrics made from fibers such as cotton or rayon are used; Furthermore, cloth impregnated or coated with a substance that easily absorbs water, that is, a hygroscopic substance, is used.

The hygroscopic sheet costs 20-809/- from the point of handling.
weight is appropriate.

3 indicates a bituminous material layer with fine gaps, and the bituminous material is tar, asphalt, etc.

To obtain the bituminous material layer 3 having minute gaps, for example, a bituminous material is applied to the nonwoven fabric 1 or the hygroscopic sheet 2 with a water repellency of 50% or more and less than 100%, and then the bituminous material is coated on the hygroscopic sheet 2 or the hygroscopic sheet 2 or the water repellent is 50%. The nonwoven fabric 1 of less than 100% may be attached and lightly pressed.

When the bituminous material layer and the nonwoven fabric are pressed together, the constituent fibers present on one side of the nonwoven fabric sink into the bituminous material layer, and cracks occur at the interface between the constituent fibers and the bituminous material, and these cracks form minute gaps. Become.

Therefore, the bituminous material is formed in a continuous layer, but it has fine pores that allow water vapor to pass through it, which means that it is moisture permeable.

In addition, the viscosity of the bituminous material is lowered and the water repellency is 50% or more and 100%.
Even if it is applied thinly to a nonwoven fabric 1 or a hygroscopic sheet 2 with a water repellency of less than A bituminous layer 3 is obtained.

In this case, the layer of applied bituminous material is thin, so that when the bituminous material hardens, it cracks and creates minute gaps.

When obtaining the bituminous material layer 3 having fine gaps, if the amount of bituminous material initially applied is about 20 to 80 g/d, fine gaps can be obtained satisfactorily by any method.

The roof base sheet of the present invention is used with the hygroscopic sheet 2 in contact with the roofing board.

As described above, the roof base sheet of the present invention is constructed so that the bituminous material layer 3 having minute gaps exists between the nonwoven fabric 1 having a water repellency of 50% or more and less than 100% and the hygroscopic sheet 2. Condensation caused by the temperature difference inside and outside the house is absorbed by the hygroscopic sheet 2, and this absorbed moisture gradually evaporates to the outside through the gaps in the bitumen layer 3 and the gaps in the nonwoven fabric.

For rainwater that enters from the outside, if it is a small amount, it will be waterproofed by the water repellency of the nonwoven fabric 1 with a water repellency of 50% or more and less than 100%, and if it is a large amount, it will be waterproofed by the bituminous layer 3 and the water repellency of 50%. % or more and less than 100% of the nonwoven fabric 1, and the roofing base sheet of the present invention exhibits waterproofness equivalent to that of a synthetic resin film.

Moreover, since the surface of the roof base sheet of the present invention is a nonwoven fabric with entangled fibers, the flexibility of the fibers prevents it from tearing when nailed, and this flexibility also closes nail holes caused by incorrectly driving nails.

Therefore, it can be said that the roof base sheet of the present invention has a waterproof property superior to that of a synthetic resin film.

In addition, since the surface of the roof base sheet of this invention is made of non-woven fabric, the surface of the roof base sheet has a rough structure, so your feet will not slip during site work, and when inking, the ink will adhere well. Furthermore, it exhibits extremely strong soil loading strength when placed on top of the earth.

In addition, nonwoven fabric has good flexibility and elasticity, so it blends well with roof tiles and is easy to work with.

If the nonwoven fabric on the surface of the roof base sheet is made white or light colored, marking can be done.

[Brief explanation of the drawing]

The drawing shows the roof base sheet of the present invention, and 1 indicates water repellency of 50.
% or more and less than 100% nonwoven fabric, 2 is a hygroscopic sheet, and 3 is a bituminous layer.

Claims (1)

[Scope of utility model registration request] A roofing base sheet formed by integrating a hygroscopic sheet and a nonwoven fabric with a water repellency of 50% or more and less than 100% via a bitumen layer having fine gaps.