JP2003221792A - Waterproof sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waterproof sheet having excellent moisture-permeable waterproofing property, light weight, nail hole sealing performance, etc., and suitable for laying on a roof sheathing, etc. <P>SOLUTION: The waterproof sheet is produced by laminating and/or embedding a microporous layer having continuous pores on or in a porous sheet substrate such as a woven fabric, a knit fabric and a nonwoven fabric. The microporous layer has a moisture permeability of ≥500 g/m<SP>2</SP>.24 hrs, a water pressure resistance of ≥5 kPa, a compressibility of ≥15%, a compressive elastic modulus of ≥50%, a wettability index of ≤45 dyne/cm and a frictional coefficient of ≥0.7. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof sheet, and more particularly to a waterproof sheet material that is laid on a roof roof plate as a building material.

[0002]

2. Description of the Related Art In roof construction, roofing materials such as roof tiles and slate are constructed on the upper surface of the base plate. Prior to the construction, a sheet called roof under roofing material is used on the surface of the base plate to enhance waterproofness. Is being fixed. As roofing roofing materials, asphalt roofing in which non-woven fabric or paper is impregnated with asphalt, sheets made of synthetic resin such as polyvinyl chloride, polyethylene, and spunbonded non-woven polyurethane composites are generally used. Are known.

[0003]

However, since the asphalt roofing does not have moisture permeability, it cannot pass moisture or water vapor, causing dew condensation and damaging the base plate. Also, one roll (length 20
Since the weight of m) exceeds 20 kg, it is very difficult to handle during work. In addition, the strength is low, and after the nail or tacker is struck, the worker works on it, causing a tear at the struck part to impair the waterproofness, i.e., the nail hole sealing property, and the rainwater that has infiltrated the base plate There is also the problem of corrosion. Further, there is a problem that water will leak if there is a slight gap between the nail or the tacker and the roofing material.

In order to improve the above-mentioned drawbacks of asphalt roofing, products using rubberized asphalt have been put on the market in recent years, but these are effective in improving nail hole sealing property and strength. , Basically, asphalt is used, so there is a problem that it has almost no moisture permeability.

Similarly, when a sheet made of synthetic resin such as polyvinyl chloride or polyethylene is used, there is a problem that it does not have moisture permeability and water leaks from the nail hole.

Further, the composite in which the non-porous polyurethane is coated on the spunbonded nonwoven fabric is lighter in weight and improved in moisture permeability as compared with the conventional product, but the nail hole sealing property is not always satisfactory. It wasn't something.

The present invention has been made in view of the above, and provides a waterproof sheet that is excellent in moisture permeability and waterproofness, lightweight, nail hole sealability, etc., and is suitably used for laying on a roof base plate or the like. The task is to do so.

[0008]

DISCLOSURE OF THE INVENTION As a result of intensive studies conducted by the present inventors in view of the above-mentioned drawbacks of the prior art, it was produced by a wet coagulation method (wet film forming method) containing a polar solvent-soluble polymer as a main component. Focusing on the fact that the membrane has excellent moisture permeability and waterproofness due to the continuous fine pores in the membrane, and also has high compression recovery and high water repellency due to its high porosity, it is used as a waterproof sheet. We found that the nail hole sealability, which is an important property, is related to the compression resilience and surface tension of the waterproof sheet, and that the greater the compression resilience and the smaller the surface tension, the better the nail hole sealability, and based on these findings, The present invention has been reached.

That is, the waterproof sheet of the present invention comprises a woven fabric,
A waterproof sheet obtained by attaching and / or burying a microporous layer having continuous pores to a sheet-like porous base material such as a knitted fabric or a nonwoven fabric, the microporous layer having a moisture permeability of 500 g / m ^2.
・ 24 hrs or more, water pressure resistance 5 kPa or more, compression rate 1
5% or more, compression modulus 50% or more, wetting index 45d
It is assumed that it is yne / cm or less and the coefficient of friction is 0.7 or more (claim 1).

The microporous layer can be formed by a wet coagulation method (claim 2).
It is preferable that the main component is at least one polar solvent-soluble polymer selected from the group consisting of vinyl type and acrylic type (claim 3).

The above-mentioned porous substrate has a bending resistance of 100.
A woven fabric made of polyester fiber and / or polyolefin fiber having a size of not more than mm can be used (claim 4).

The waterproof sheet of the present invention may be one in which a non-porous moisture permeable layer having a friction coefficient of 0.7 or more is laminated on the surface of the microporous layer (claim 5).

The waterproof sheet of the present invention having the above structure is preferably used as a waterproof sheet laid on a roof roof plate (claim 6).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The porous substrate in the waterproof sheet of the present invention is a porous sheet-like material which can reinforce the microporous layer without impairing the moisture permeability of the microporous layer. However, the present invention is not limited to this, and examples thereof include textile products such as woven fabrics, knitted fabrics, and non-woven fabrics. By using such a porous base material, it is possible to impart flexibility and mechanical strength to the waterproof sheet, thereby improving workability.

The porous substrate is preferably one having a mechanical strength of 100 N / cm or more in tensile strength and a flexibility of 100 mm or less in terms of bending resistance (cantilever method) and a fiber thickness of 100 dtex or more. , Weight 50g /
m ² , weave density of 30 × 30 / inch to 100 × 10
A woven fabric made of polyester fibers and / or polyolefin fibers of 0 fibers / inch is particularly preferable.

Next, the microporous layer having continuous pores in the waterproof sheet of the present invention is a layer having an infinite number of fine continuous pores formed by a wet coagulation method, and is a polar solvent which is an essential component. It is composed of a soluble polymer and additives such as a filler, a water / oil repellent agent, a cross-linking agent, and a pigment, which are optionally used. The average pore size of continuous pores is 100μ.
m or less, preferably about 0.1 to 30 μm.

Here, the polar solvent-soluble polymer is
It is not particularly limited as long as it can be dissolved in a polar solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, dioxane, N-methylpyrrolidone. , Polyacrylate,
Acrylic resin such as polyacrylonitrile, vinyl resin such as polyvinyl chloride, polyvinyl acetate, polyvinyl fluoride, epoxy resin, polysulfone system, polyether sulfone system, phenolic resin, polystyrene system,
Polyamide-based, polyester-based, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, and their fluorine and silicone derivatives are used. Above all, it is preferable to use one or more selected from urethane-based, ester-based, vinyl-based, and acrylic-based resins.

Further, as usable additives, calcium carbonate, talc, kaolin, silica, alumina, diatomaceous earth, graphite, aluminum hydroxide, magnesium hydroxide,
Powdered inorganic materials such as calcium silicate, short fiber slag fiber, ceramic fiber, glass fiber, etc., isocyanate-based, amine-based cross-linking agents, silicone-based, fluorocarbon-based, long-chain fatty acid salt-based, long-chain amine salt-based etc. Examples of the water repellent and / or oil repellent, surfactants and the like. Of these, silica, calcium carbonate, talc, kaolin-based inorganic fillers, diatomaceous earth, silica gel, zeolite, activated carbon, porous materials such as sepiolite, isocyanate-based crosslinking agents, silicone-based or fluorine-based water and oil repellents are preferably used. To be

The microporous layer having continuous pores preferably has a moisture permeability of 500 g / m ² · 24 hrs or more. When the moisture vapor transmission rate is less than 500 g / m ² · 24 hrs, the water vapor permeability becomes insufficient, dew condensation occurs, and the base plate is easily corroded. Water vapor transmission rate is 3000g / m ² · 24hrs
The above is more preferable.

The water pressure resistance of the microporous layer is preferably 5 kPa or more. If the water pressure resistance is less than 5 kPa, it is difficult to prevent rainwater from entering from the outside, and water leakage easily occurs. The water pressure resistance is more preferably 20 kPa or more.

It is preferable that the compressive modulus is 15% or more and the compressive elastic modulus is 50% or more. If the compression rate is less than 15%, the nail and the sheet will not be in close contact when the nail is driven in, and a gap will be created, and water will enter there and water will easily leak. Further, if the compression elastic modulus is less than 50%, the force for pressing the driven nail is weakened, the effect of tightening the nail is reduced, a gap between the nail and the sheet is generated, and water easily leaks.

The surface of the microporous layer having continuous pores preferably has a wetting index of 45 dyne / cm or less. When the wetting index is 45 dyne / cm or more, the sheet easily gets wet with water, and the water easily enters the gap between the driven nail and the sheet and easily leaks water. The surface of the microporous layer preferably has a friction coefficient of 0.7 or more.

The weight of the microporous layer is not particularly limited, but is usually 5 to 500 g / m ^2, and 10 to 200 g / m ^2.
m ² is preferred. If it is less than 5 g / m ² , the compression-restoring effect cannot be exhibited and the nail hole sealing property becomes insufficient. Also, 5
If it exceeds 00 g / m ² , it is too heavy and there is a problem in lightness.

In general, materials having both moisture permeability and waterproofness are largely classified into non-porous type such as urethane type and ester type in which a hydrophilic group is introduced into polymer and microporous type used in the present invention. Be separated.

In the former case, since there are no voids in the film, the compression restoring property, especially the compressibility is small, and since the hydrophilic group is introduced, the film has a high degree of hydrophilicity and its surface is very wet. easy. As a result, when the nail is driven into the waterproof sheet, the adhesion around the nail axis of the sheet decreases as described above,
Since a gap is likely to occur and the sheet is very easily wet,
Water easily penetrates even into a small gap between the nail and the sheet, and water easily leaks.

On the other hand, the microporous membrane used in the present invention is
The number of minute pores in the membrane and the high degree of water repellency give it superior moisture permeability and waterproofness compared to a non-porous membrane, and it has high compression recovery due to its high porosity. At this time, the adhesiveness around the nail axis and the tightening effect are excellent, it is difficult to form a gap, and the high water repellency further prevents water from entering the gap, and the nail hole sealability is improved.

After the tarpaulin is laid on the field board and fixed with nails, tackers, etc., the roofing material is constructed. To ensure the safety of the worker at that time, the tarpaulin is used. Requires slip resistance. That is, by providing anti-slip properties between the base plate and the waterproof sheet, and between the waterproof sheet and the foot of the worker, the construction work can be efficiently and safely performed. In order to satisfy this anti-slip property, the friction coefficient of the microporous layer is preferably 0.7 or more. When the coefficient of friction is less than 0.7, slippage easily occurs between the base plate and the waterproof sheet and between the waterproof sheet and the feet of the worker, so that work efficiency and safety are reduced.

In order to further improve the slip resistance, a known slip prevention treatment method can be used. For example, various synthetic resins may be used alone or as a mixture with an inorganic filler, a microcapsule-based foaming agent, hollow particles, or the like, and a method of adhering them on at least one side, preferably both sides, of the sheet in the entire surface or in a dot shape. However, it is not limited to this.

More preferably, the non-porous moisture permeable layer is laminated and integrated on the surface of the microporous layer to improve the slip resistance without impairing the moisture permeability. As the non-porous moisture permeable layer, the main component is a hydrophilic polymer such as urethane-based, ester-based, or vinyl-based thermoplastic polymer,
A friction coefficient of 0.7 or more is preferable. When the coefficient of friction is less than 0.7, the work efficiency and the safety are deteriorated because slippage easily occurs between the base plate and the waterproof sheet and between the waterproof sheet and the foot of the operator. This layer can be applied to the whole or a part of the processed surface as long as the moisture permeability is not impaired.

The waterproof sheet of the present invention is one in which the above-mentioned porous base material and the microporous layer are integrated, and is applied to the porous base material by a method such as a direct coating method, an impregnation method or a laminating method. It is manufactured by applying a microporous layer.

That is, a polymer solution dissolved in a polar solvent is used as a main component on one or both sides of a porous substrate such as a woven fabric or a non-woven fabric which has been previously subjected to a water repellent treatment, if necessary, and a filler, water repellent / repellent agent A slurry in which an oil agent, a cross-linking agent, etc. are mixed is coated to have a predetermined thickness by a normal coating method such as a direct method or a reverse method using a knife coater or a roll coater, or these porous base materials are coated. After impregnating so that it spreads over the entire thickness, it is immersed in a coagulation tank and cured in water or a mixed solvent of water and a polar solvent as described above (wet coagulation method) to form the desired microporous layer. Then, the waterproof sheet of the present invention is obtained by washing with water and drying. The conditions such as temperature and time for performing wet coagulation may be appropriately selected according to the resin used.

Alternatively, the microporous membrane and the woven fabric or non-woven fabric, which are produced by applying the above slurry to release paper by a casting method or the like and performing a wet coagulation method, using a gravure roll coater or a knife coater, a dry laminating method. The waterproof sheet of the present invention can also be obtained by bonding by the wet laminating method.

Further, if it is desired to further improve the slip resistance, a water-soluble or solvent-soluble, hydrophilic, moisture-permeable polymer is applied to one or both sides of the microporous layer or porous substrate of the waterproof sheet. By coating the slurry containing the main component by the same coating method as described above to a predetermined thickness and then drying, a waterproof sheet having a non-porous moisture permeable layer with improved slip resistance can be obtained.

As can be seen from the above, the relationship between the porous base material and the microporous layer in the waterproof sheet of the present invention is that the microporous layer is present only on the surface (one side or both sides, the same applies hereinafter) of the porous base material. Attached, a microporous layer attached to the surface of the porous substrate, and this microporous layer extends beyond the surface of the porous substrate to the inside, Any of those having a porous layer formed thereon (that is, those not forming separate layers) may be used. Furthermore, the microporous layer does not necessarily have to be exposed on the surface, and the microporous layer may be formed (embedded) inside the porous substrate.

[0035]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

The various physical properties described in the following Examples, Comparative Examples and other specifications are based on the following measuring methods.

[Moisture Permeability (Moisture Permeability)] JIS L 109
9 (A-1 method); [Water pressure resistance (waterproofness)] JIS L 1092 (high water pressure method); [Nail hole sealing] 20 mm thick plywood Place a filter paper on it, put a waterproof sheet on it, and drive concrete nails (38 mm long, 2.6 mmφ) from the top of the waterproof sheet to the extent that they do not penetrate the plywood, and place a 40 mmφ PVC pipe around the nailed area. Stand it up and seal it to prevent water from leaking around the pipe. After the seal dries
Inject 190 ml of water into the pipe, leave it at room temperature for 24 hours,
Determine whether water leaks from around the nails. The judgment is that the filter paper between the plywood and the waterproof sheet is wet when there is water leakage, and when not wet, there is no water leakage; [Compressibility / compression elastic modulus] load is 3 kg / cm ² . Other than that, it is measured according to JIS L1096; [Wet index] It is measured according to JIS K6768; [Flexibility (flexibility)] It is measured according to JIS L1096; [Frictional coefficient (slip resistance)] ] Using a static friction coefficient measuring device (HEIDON-10 manufactured by Shinto Kagaku Co., Ltd.), a sample having a size of 80 mm × 200 mm was fixed on a flat plate whose angle was adjustable, and a size of 35 mm × 70 mm was fixed thereon. Thickness 3.
A 2 mm rubber sheet is attached and a load of 6.5 g / cm ² is applied. Then, the plane plate is gradually inclined, the inclination angle θ when the sample starts to slide is measured, and the value indicated by the tangent tan θ is taken as the friction coefficient.

[Example 1] As a porous substrate, a polyester fiber woven fabric having a flexibility of 44 mm in length and 33 mm in width and a weight of 95 g / m ² which had been subjected to a water repellent treatment was blended according to the following [Formulation 1]. After coating the slurry with a knife over roll method, wet coagulation (immersing in water at 20 ° C. for 10 minutes, the same in the following Examples and Comparative Examples), washing with water, and drying (140 ° C. for 10 minutes,
The same applies to the following Examples and Comparative Examples) to obtain a waterproof sheet having a microporous layer formed on one side of the woven fabric and in the vicinity thereof. About the obtained waterproof sheet, breathable, waterproof,
The nail hole sealability, lightness, slip resistance, and flexibility were evaluated or measured. The results are shown in Table 1. The physical properties of the microporous layer alone are as follows: moisture permeability 11200 g / m ² · 24 hrs, water pressure resistance 96 kPa, compression rate 35%, compression elastic modulus 63%, wetting index 35 dyne / cm, friction coefficient 1.4, weight 10
It was 0 g / m ² .

[0039] [Compound 1]                                                                   Parts by weight   Crisbon MP829     (Polyurethane resin, manufactured by Dainippon Ink and Chemicals, Inc.) 100   DMF (solvent) 40   Nipseal E-200 (filler, manufactured by Nippon Silica Industry Co., Ltd.) 3   Dailac L-3026 (pigment, manufactured by Dainippon Ink and Chemicals, Inc.) 5   Dickguard NH-10 (water repellent, manufactured by Dainippon Ink and Chemicals, Inc.) 3

[Example 2] A microporous layer was prepared in the same manner as in Example 1 except that the same polyester woven fabric as in Example 1 was used as the porous substrate and the composition was as shown in the following [Composition 2]. Formed. The physical properties of this microporous layer alone are 1
0200 g / m ² · 24 hrs, water pressure resistance 73 kPa or more, compression rate 30%, compression elastic modulus 78%, wetting index 35 d
It was yne / cm, the friction coefficient was 1.4, and the weight was 30 g / m ² .

Next, the surface of this microporous layer was coated with a slurry prepared according to the following [Formulation 3] by a floating knife method and then dried to obtain a friction coefficient of 1.1.
As described above, a waterproof sheet was further laminated with a non-porous moisture permeable layer having a weight of 20 g / m ² . With respect to the obtained waterproof sheet, moisture permeability and the like were measured in the same manner as in Example 1.

[0042] [Formulation 2]                                                                   Parts by weight   Crisbon MP829     (Polyurethane resin, manufactured by Dainippon Ink and Chemicals, Inc.) 100   DMF (solvent) 40   Calcium carbonate CC (filler, Shiraishi industry) 6   Dailac L-3026 (pigment, manufactured by Dainippon Ink and Chemicals, Inc.) 5

[0043] [Compound 3]                                                                   Parts by weight   Heimren Y-237     (Polyurethane resin, Dainichiseika Co., Ltd.) 100   MEK (solvent) 40

[Example 3] The same polyester fabric as in Example 1 was previously produced by a casting method from the slurry according to the above [Compound 1] by a water vapor transmission rate of 11200 g / m ² · 2.
4 hrs, water pressure resistance 96 kPa, compression rate 35%, compression elastic modulus 63%, wetting index 35 dyne / cm, friction coefficient 1.
4 weight microporous membrane of 30 g / m ^2, integrated gravure, by dry lamination method using an urethane adhesive 30 g / m ^2, to obtain a waterproof sheet. With respect to the obtained waterproof sheet, moisture permeability and the like were measured in the same manner as in Example 1.

[Comparative Example 1] The same polyester fabric as in Example 1 was coated with the slurry prepared according to the above [Compound 3] by a floating knife method and then dried to laminate a non-porous moisture permeable layer. I got a tarpaulin. With respect to the obtained waterproof sheet, moisture permeability and the like were measured in the same manner as in Example 1. The physical properties of the non-porous moisture permeable layer alone are as follows: moisture permeability 3200 g / m ² · 24 hrs, water pressure resistance 195 kP
a or more, compression rate 12%, compression elastic modulus 89%, wetting index 4
5 dyne / cm, friction coefficient 1.1, weight 20 g / m ²
Met.

Comparative Example 2 The same polyester fabric as in Example 1 was coated with a slurry prepared according to the following [Formulation 4] by a knife over roll method, wet-coagulated, washed with water and dried to obtain a fabric. A waterproof sheet having a microporous layer formed on one surface and in the vicinity thereof was obtained. With respect to the obtained waterproof sheet, moisture permeability and the like were measured in the same manner as in Example 1. In addition, the physical properties of the microporous layer alone are 1210
0g / m ² / 24hrs, water pressure resistance 86kPa, compression rate 3
5%, compression modulus 63%, wetting index 50 dyne / c
m, the coefficient of friction was 1.4, and the weight was 30 g / m ² .

[0047] [Formulation 4]                                                                   Parts by weight   Crisbon MP829     (Polyurethane resin, manufactured by Dainippon Ink and Chemicals, Inc.) 100   DMF (solvent) 40   Nipseal E-200 (filler, manufactured by Nippon Silica Industry Co., Ltd.) 3   Dailac L-3026 (pigment, manufactured by Dainippon Ink and Chemicals, Inc.) 5

[0048]

[Table 1]

[0049]

The waterproof sheet of the present invention has a structure in which microporous membranes having continuous pores formed on at least one side of a porous base material are laminated and integrated, so that the microporous membrane has innumerable fine pores. It has excellent moisture permeability and waterproofness based on the above, light weight and high compression recovery based on high porosity, and excellent nail hole sealing property based on high compression recovery and water repellency, and it is also integrated with porous substrate By being made into a material, mechanical strength and flexibility are provided. Therefore, at the time of construction, since it is lightweight and has appropriate flexibility, mechanical strength and slip resistance, it is easy to handle, and is excellent in workability and safety. In addition, after construction, there is no water leakage from the nail holes, it is excellent in waterproofness, it releases the water vapor generated from the room to the outside and prevents the occurrence of dew condensation in the field, so it is extremely useful for improving the durability of the roof Is.

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Claims (6)

[Claims] 1. A waterproof sheet in which a microporous layer having continuous pores is attached and / or embedded in a sheet-like porous base material such as a woven fabric, a knitted fabric, and a non-woven fabric, wherein the microporous layer has a moisture permeability. Is 500 g / m ² · 24 hrs
As described above, the water pressure resistance is 5 kPa or more, the compression rate is 15% or more, the compression elastic modulus is 50% or more, and the wetting index is 45 dyne / cm.
Hereinafter, a waterproof sheet having a friction coefficient of 0.7 or more. 2. The waterproof sheet according to claim 1, wherein the microporous layer is formed by a wet coagulation method. 3. The microporous layer comprises, as a main component, at least one polar solvent-soluble polymer selected from the group consisting of urethane series, ester series, vinyl series, and acrylic series. The waterproof sheet according to Item 1 or 2. 4. The porous substrate is a woven fabric made of polyester fiber and / or polyolefin fiber having a bending resistance of 100 mm or less.
The waterproof sheet according to any one of items 1 to 3. 5. The friction coefficient is 0.7 on the surface of the microporous layer.
The waterproof sheet according to any one of claims 1 to 4, wherein the non-porous moisture permeable layer is laminated. 6. The waterproof sheet according to claim 1, wherein the waterproof sheet is laid on a roof roof plate.