JP3408728B2 - Roof underlay waterproofing sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof sheet used for a roofing material. [0002] Wooden sloped roofs are covered with various types of roofing materials such as tiles, residential roof slate, and metal plates. However, it is difficult to obtain a complete waterproofing function using only these roofing materials.Conventionally, underlaying materials, such as asphalt felt, in which asphalt is impregnated or applied to paper or the like, are laid between the roofing materials such as tiles and the ground board. It was used as a waterproof sheet. However, when roofing tiles in recent years, especially when using tiles called slate roof tiles, nails are driven from the top of the slate roof tiles and fixed through the waterproof sheet to the ground board. There has been a problem that rainwater or the like penetrates through the gap between the waterproof sheet and the nail and penetrates the field plate, causing the field plate to corrode. [0003] In order to solve such a problem, a waterproof sheet for a roof made by laminating a cloth on the surface of a water vapor permeable polyolefin resin film (JP-A-5-248043).
Publication) and a synthetic sheet having a rebound resilience of 15% or more laminated on both outer surfaces of a joined sheet obtained by locally joining two porous sheets having fine holes. Composite sheet for building materials (JP-A-7-268971)
Also, a technique such as a water-impervious sheet in which a highly water-absorbing polymer is fixed to at least one surface of a flash-spun polyolefin-based nonwoven fabric (JP-A-7-279054) is disclosed. When attaching a waterproof sheet to a field board, it is necessary that the waterproof sheet has such flexibility that it can be adhered and covered along the field board. In order to walk on the top, high breaking strength, tear strength is necessary to not break, and furthermore, the worker does not slip while walking on the waterproof sheet, or the waterproof sheet itself placed on the field board, Slip resistance and cushioning properties are required so that the tarpaulin does not slip when the tile is placed on the tarpaulin.However, none of the above technologies has been found to satisfy these required characteristics, and further improvement is required. And it was. SUMMARY OF THE INVENTION An object of the present invention is to provide a waterproofing sheet for a roofing material which is excellent in waterproofing of nail holes, high in strength, flexible, slip resistant and cushioning. I do. [0006] The present invention provides a JIS-K6
A fibrous material in which a synthetic fiber filament is densely and non-directionally deposited and bonded on the back side with a 50-200 μm thick film containing a polyolefin resin having a resilience of 15% or more as measured as an intermediate layer as an intermediate layer. The gist of the present invention is a waterproof sheet for roof underlaying material, in which a nonwoven fabric is laminated, and synthetic resin drawn yarns are laminated on the surface side in one direction in parallel or in a lattice form from two directions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A waterproof sheet of the present invention has a synthetic resin stretched yarn 4 / of a surface layer as shown in FIG.
It is composed of a laminate having a three-layer structure of the film 2 of the intermediate layer / the fibrous nonwoven fabric of the back layer. As the film 2 of the intermediate layer constituting the present invention, it is necessary to use a resin component containing a polyolefin resin having an elastic modulus of 15% or more measured according to JIS-K6301. The proportion of the polyolefin resin is preferably 50 to 100% by weight. By using this resin component, the gap between the nail and the sheet adheres closely to each other due to the resilience of the resin component in the nail hole formed by using the nail, and leakage of rainwater or the like can be prevented. Even if a polyolefin resin having a resilience of less than 15% is used, it is difficult to prevent water leakage from the gap between the nail and the sheet caused by nailing as described above. Further, the thickness of the film 2 is a resin layer having a thickness of 50 to 200 μm, preferably 80 to 150 μm. Thickness 5
If it is less than 0 μm, it is difficult to prevent water leakage from the gap between the nail and the sheet. If it exceeds 200 μm, the weight increases, handling becomes difficult, and it is not economical. Specific examples of the polyolefin resin used for the film 2 include polyolefin resins such as ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene. -Polyolefin-based thermoplastic elastomers using propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, etc., soft polyolefin resins containing amorphous polyolefins, etc., and these may be used alone or as a mixture of two or more. What is necessary is just to select what satisfy | fills the said elastic modulus range. Next, a fibrous nonwoven fabric 3 is laminated on the back side of the film 2 serving as an intermediate layer. The fibrous nonwoven fabric 3 is laminated for the purpose of improving the followability on the ground board, the adhesion, and the dimensional stability of the waterproof sheet, and the short fibers formed by the wet method or the dry method depending on the manufacturing method. Non-woven fabric and long-fiber non-woven fabric can be used. Among the fibrous non-woven fabrics 3, a long-fiber non-woven fabric having high strength and durability, which has little detachment of fibers, is particularly preferable. This long-fiber non-woven fabric is a non-woven fabric in which synthetic resin long-filament filaments are deposited and bonded in a high-density and non-directional manner, and the continuous fibers are continuously spun, drawn, opened, and bonded by a direct spinning method. It is obtained by random deposition and bonding.Specifically, a spinnable synthetic resin is put into an extruder to be in a molten state, and the fiber extruded from a spinning nozzle is drawn by a roller method or an air jet method. Non-woven fabric by spunbond method to form fiber, non-woven fabric by melt-blow method to melt and draw resin from spinning nozzle together with high-pressure gas stream to form drawn fiber, or solution of spinnable synthetic resin dissolved in solvent at high temperature and high pressure Is discharged into the atmosphere through a spinning nozzle, and a non-woven fabric by a flash spinning method in which a solvent is vaporized to form a fiber. Next, on the surface side of the film 2 serving as the intermediate layer, the synthetic resin drawn yarns 4 are laminated in parallel in one direction or in a lattice form from two directions. The synthetic resin stretched yarn 4 has a high breaking strength and a tearing strength that are not broken because the worker steps on the sheet as a usage form of the waterproof sheet for the roof underlaying material. Are laminated for the purpose of forming irregularities so as not to slip during walking. The stretched synthetic resin yarn 4 is obtained by thermoforming and spinning a thermoplastic resin, and then drawing it to impart high strength. The thermoplastic resin used here is not particularly limited, but a polyolefin-based resin is preferably employed because it is inexpensive, has stable quality, and can be continuously produced. As the shape of the yarn, flat yarn, split yarn, multifilament, monofilament and the like can be used without limitation. These yarns are subjected to thermal stretching after spinning and become high in strength, and the thermal stretching is performed at a temperature not higher than the melting point of the resin to be used and at a temperature not lower than the softening point. Is preferably 3 to 20 times, more preferably 5 to 20 times.
It is 15 times. The fineness of the synthetic resin stretched yarn 4 thus obtained is practically 500 to 3000 denier.
Preferably, it is 500 to 2500 denier. In other words, if it is less than 500 denier, the strength as a reinforcing material of the waterproofing sheet for roof underlaying material is not sufficient, and if it exceeds 3000 denier, it lacks flexibility and is inferior in workability and handleability. Further, it is preferable that the breaking strength of the single yarn is 4.0 g / denier or more. That is, if it is less than 4.0 g / denier, the strength becomes insufficient as a reinforcing material for a waterproof sheet used for a roof underlaying material. As the form of the arrangement of the synthetic resin drawn yarns 4, the longitudinal direction of the sheet is preferable when the yarns are arranged in parallel in one direction at appropriate intervals, and the longitudinal direction of the sheet when the lattices are arranged in two directions. Preferably, the direction is orthogonal to the longitudinal direction. Here, the synthetic resin stretched yarn 4 may be a general single-layer yarn, but it is effective in that the composite yarn can be easily and firmly bonded by heat fusion in the laminating step. As the composite yarn, it is preferable that at least a part of the surface of the core layer composed of the polyolefin high melting point component is coated with the polyolefin low melting point component from the viewpoint of adhesiveness to the film 2 of the intermediate layer. , A laminated flat yarn in which a polyolefin low melting point component layer is provided on both surfaces of an intermediate layer made of a polyolefin high melting point component,
A core / sheath type monofilament composed of a core layer of a polyolefin high melting point component and a sheath layer of a polyolefin low melting point component is exemplified. Specific examples of the polyolefin high-melting point component used in the composite yarn include high-density polyethylene, medium-density polyethylene, and polypropylene, and these may be used alone or in combination of two or more. . Examples of the polyolefin low melting point component include ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, and ethylene / α-olefin of ethylene produced using a metallocene catalyst and α-olefin having 3 or more carbon atoms. Polymers, ethylene-vinyl acetate copolymers, polyethylene-based resins such as ethylene-acrylate copolymers and propylene-ethylene copolymers, polypropylene-based resins such as syndiotactic polypropylene, and the like. They may be used alone or in combination of two or more. Here, in the combination of the high-melting point component and the low-melting point component, it is preferable that a stretching effect is obtained and high tenacity is obtained, and that thermal degradation does not occur when coating the polyolefin low-melting point component. The difference in melting points is preferably at least 10 ° C, more preferably at least 20 ° C. The synthetic resin stretched yarn 4 of the surface layer, the film 2 of the intermediate layer, which are constituent members of such a waterproof sheet,
When laminating the fibrous nonwoven fabric 3 as the back layer, the adhesive is integrated by a method using an adhesive, a method by heat fusion, a method by extrusion lamination, or a combination thereof. EXAMPLES Test Method Nail Hole Sealing Property: At room temperature (20 to 25 ° C.), a PVC pipe having a diameter of 40 mm is erected around a nail that has been nailed on a roofing material so that water does not leak from around the pipe. After sealing with an irregular sealing material, water was injected, and 24 hours later, the presence or absence of water leakage from around the nail was examined. In the determination of the presence or absence of water leakage, it was determined that there was water leakage when the filter paper between the base material and the underlaying material was wet, and that there was no water leakage when the filter paper was not wet. The test results were obtained by counting the number of water leaks out of 10 samples. Example 1 As the fibrous non-woven fabric 3, a non-woven fabric having a basis weight of 60 g / m ² was prepared, in which polyester produced by a spun bond method was used as a core layer and polyethylene was used as a sheath layer. Further, as the synthetic resin drawn yarn 4, a multilayer film in which high-density polyethylene is used as a core layer and low-density polyethylene is provided on both outer layers is formed by an inflation method. After slitting, the film is drawn at a draw ratio of 6 times to obtain a composite having a fineness of 900 denier. Flat yarn was prepared. Next, an ethylene-propylene-diene copolymer (having a modulus of elasticity of 40% as measured according to JIS-K6301) is extruded at an extrusion temperature of 180 ° C. to form a film 2 having a thickness of 100 μm. The composite flat yarns are arranged in parallel in the longitudinal direction of the film at a density of 3 / inch on the surface side of the film, and after pre-heating the laminate,
The three-layer member was heat-sealed and integrated by pressing with a heating roll to obtain a waterproof sheet of Example 1. FIG. 2 shows the waterproof sheet of the first embodiment. Example 2 As the fibrous nonwoven fabric 3, a nonwoven fabric having a basis weight of 50 g / m ² prepared by fibrillating high-density polyethylene by flash spinning was prepared. Further, the composite flat yarn used in Example 1 was used.
The fibers were arranged as a synthetic resin drawn yarn 4 at a rate of 2 lines / inch in a lattice pattern, and the weft intersections were temporarily bonded by heat treatment. Next, a soft polyolefin resin containing an amorphous polyolefin (having an elastic modulus of 35% as measured according to JIS-K6301) was extruded at an extrusion temperature of 180 ° C.
A film 2 having a thickness of 00 μm is formed, a nonwoven fabric is placed on the back side of the film 2, and a grid of composite flat yarn is placed on the front side. The members were heat-sealed and integrated to obtain a waterproof sheet of Example 2. FIG. 3 shows a waterproof sheet according to the second embodiment. With respect to the waterproof sheets of Examples 1 and 2, the evaluation result of the water stopping property of the nail holes by the nail hole sealing property test method was 0/10, and no water leakage was confirmed. In addition, when actually used as a roof underlaying material, the fibrous nonwoven fabric is laminated on the back side, so it adheres flexibly to the ground board, and the presence of the synthetic resin drawn yarn on the front side enhances the reinforcing effect and prevents slippage in work The effect was shown, and the work efficiency of spreading and fixing the waterproof sheet was also good. Comparative Example Based on the structure of Example 2, the film of the intermediate layer was
Low-density polyethylene having a thickness of 00 μm (JIS-K630
Comparative Example 1 was prepared in the same manner as in Example 1 except that the elastic modulus of the intermediate layer measured in Example 1 was 10%).
Ethylene-propylene copolymer having a thickness of 00 μm (JIS
Comparative Example 2 was prepared in the same manner as that described above except that the elastic modulus measured by -K6301 was 11%). Since the evaluation results of the water stopping performance of the nail holes by these nail hole sealing property test methods were both 10/10, water leakage occurred from the nailed portions, and it was evaluated as unsuitable as a waterproofing sheet for a roof underlaying material. . As described above, the waterproof sheet for roof underlaying material of the present invention has a nail hole due to the elasticity of a film containing a polyolefin resin having an elastic modulus of 15% or more used for the intermediate layer. Excellent water-blocking properties, and because the fibrous nonwoven fabric is laminated on the back side, the sheet adheres flexibly along the base plate, and has slip resistance between the base plate and the cushioning property, Because the synthetic resin stretched yarns are arranged and laminated on the front side, the mechanical strength of the sheet is increased,
By providing a non-slip effect when an operator rides on the sheet, it becomes effective as a waterproof sheet for a roofing material in terms of functionality and handleability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a waterproof sheet for roof underlaying material of the present invention. FIG. 2 is a partially broken plan view of the waterproof sheet of Example 1. FIG. 3 is a partially broken plan view of a waterproof sheet according to a second embodiment. [Description of Signs] 1 Waterproof sheet 2 Film 3 Fibrous nonwoven fabric 4 Synthetic resin drawn yarn

Claims (1)

(57) [Claim 1] A 50-200 μm thick film containing a polyolefin resin having a resilience of 15% or more as measured by JIS-K6301 as an intermediate layer, Roof characterized by laminating a fibrous nonwoven fabric in which synthetic fiber filaments are deposited and bonded in a high-density and non-direction, and synthetic resin stretched yarns are laminated on the surface side in one direction in parallel or in a lattice from two directions Waterproof sheet for underlaying material.