JP2008190157A - Waterproof sheet material for roof floor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waterproof sheet material for a roof floor, which is equipped with both high heat resistance and high waterproofness brought about by a self-repairing function. <P>SOLUTION: This waterproof sheet material for the roof floor is composed of a water-swelling material which exerts the self-repairing function on a lost portion by water swelling. The water-swelling material contains an organic adhesive and mineral with water swelling properties; the organic adhesive contains asphalt, a temperature-sensitive modifier, and one or more selected from the group consisting of gelled oil, a softener and a liquid resin, according to need; the 1-15 mass% temperature-sensitive modifier is contained in the water-swelling material; and the total content of the gelled oil, the softener and the liquid resin is 45 mass% or less based on the mass of the water-swelling material. The waterproof sheet material for the roof floor comprises, for example, a water-swelling material layer 1 which is composed of the water-swelling material, a reinforcing material 2, and a protective layer 3 which is provided on the surface of the water-swelling material layer 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rooftop waterproofing sheet material having water swellability used on the rooftop of buildings in the field of construction and civil engineering.

  Conventional rooftop waterproofing methods for structures in the field of construction and civil engineering include: (1) Asphalt waterproof thermal construction method in which asphalt roofing is laminated with heat-melted asphalt; A modified asphalt waterproofing (room temperature / torch) method for laying a modified asphalt proofing sheet impregnated on a nonwoven fabric of fiber, etc. (3) A sheet waterproofing method for laying a polymer-based waterproof sheet made of synthetic rubber or synthetic resin, Or (4) Widely used methods such as coating film waterproofing method, where liquid rubber or resin material is applied on-site with a brush, spatula, roller, or by a spraying machine to form a film and solidify to form a waterproof layer It has been. These construction methods have been adopted as appropriate by taking advantage of their respective strengths, but each has the following problems.

  That is, in the above construction method (1), since a single-layer asphalt roofing sheet is not reliable in waterproof performance, molten asphalt is applied between a plurality of asphalt roofing sheets. In many cases, the resulting membrane is not a fatal defect in waterproofing even if a few construction mistakes or a sudden accident at the site occur due to the effect of multilayering. However, this method requires multiple asphalt roofing sheets to be constructed, which requires a lot of labor and time, and is associated with the danger of smoke and odor generation due to asphalt dissolution during construction, and high-temperature work and use of fire. However, it has not solved the shortcomings such as shortage of technicians. In addition, in the methods (2) and (3), the work of joining the waterproof sheet material is important, and in order to obtain a reliable waterproof effect, a reliable construction management is necessary. There is a drawback that a waterproof effect cannot be obtained when a defective portion occurs. In the method (4), it is possible to form a seamless waterproof layer by forming and curing a curable resin such as urethane rubber or acrylic rubber in the field. It is easy to depend on the skill level of a person, and since the material used is expensive, it is often applied to renovation work and waterproofing of a small area. Moreover, when a defect | deletion part, such as a crack and a tear, arises in a waterproof layer after construction, the point that waterproof performance falls extremely is mentioned as a problem common with the said conventional waterproofing construction method.

On the other hand, Patent Document 1 describes a water-swellable composition having a self-healing function. The waterproof sheet material using this water-swellable composition can prevent deterioration of waterproof performance when a defect such as a crack or tear occurs due to its self-healing function. However, this waterproof sheet material has a problem in that the waterproof performance is lowered under severe environmental conditions such as high temperature by direct sunlight on the rooftop or conversely in cold regions.
Japanese Patent Laid-Open No. 10-338812

  The present invention has been made in view of the conventional technology as described above, and provides a roofing waterproof sheet material having both high heat resistance, crack prevention at low temperatures, and high waterproofness by a self-repair function. Objective.

  The present inventor increases the heat resistance while maintaining the waterproof property due to the self-healing function of the water-swellable material by setting the blending ratio of the temperature-sensitive modifier in the organic adhesive contained in a specific range. Found that it would be possible. The present invention has been completed based on these findings.

That is, the present invention
(1) A roofing waterproof sheet material using a water-swellable material that exhibits a self-healing function by water swelling with respect to a defect portion, wherein the water-swellable material has a water-swelling property and an organic adhesive. The organic pressure-sensitive adhesive contains one or more selected from the group consisting of asphalt, temperature-sensitive modifier, further gelled oil, softener, and liquid resin as necessary, A temperature-sensitive modifier is contained in the water-swellable composition in an amount of 1 to 15% by mass, and the combined content of the gelled oil, softener, and liquid resin is 45% by mass in the water-swellable material. Rooftop waterproof sheet material characterized by:
(2) The water-swellable material further contains a water-swellable rubber, the roofing waterproof sheet material according to (1),
(3) The roofing waterproof sheet according to (1) or (2), wherein the water-swellable mineral is at least one selected from the group consisting of bentonite, smectite, and swellable mica. ,
(4) The waterproof sheet material for rooftop according to any one of (1) to (3), comprising the water-swellable material and a reinforcing material,
(5) The roofing waterproof sheet material according to (4), wherein the reinforcing material is a non-woven fabric, woven fabric, or fiber made of polyester resin, polyvinyl resin, or polyethylene resin, or kraft paper. And (6) any one of (1) to (5), wherein a protective layer made of silica sand, bentonite, smectite, swellable mica, alkali-decomposable resin film, or water-soluble resin film is provided on the surface The rooftop waterproofing sheet material according to item 1 is provided.

  The roofing waterproof sheet material of the present invention, clogged defects such as cracks and cracks generated in harsh environments, or voids caused by poor adhesion in construction, etc., are closed by the self-repairing function of the waterproof sheet material itself, High waterproofness can be realized. In addition, when the waterproof sheet material is used in an overlapping manner, the water-swellable material layers come into contact with each other, so that the water-swellable material can be integrated and the water-swellable material can be used even if the adhesive force is insufficient and voids are generated. Owing to swelling of the gap, the gap can be closed and high waterproofness can be exhibited. Therefore, by using the prevention sheet of the present invention, a high rooftop waterproof property can be easily obtained by a construction method that does not require a high degree of construction management. Moreover, since even a single-layer sheet material exhibits high waterproofness, it is not necessary to construct a plurality of sheets, and time and labor can be greatly reduced.

Next, the present invention will be described in detail.
FIG. 1 is a cross-sectional view showing a preferred embodiment of the roofing waterproof sheet material of the present invention. In FIG. 1, the reinforcing material 2 is laminated on one surface of the water-swellable material layer 1, and the protective layer 3 is laminated on the other surface. The reinforcing material 2 and the protective layer 3 are not essential, but are preferably provided. The reinforcing material 2 may be a face material as shown in FIG. 1 or may be a core material sandwiched between the centers of the water-swellable material layer 1, but functions as an insulating layer when placed on the protective concrete side as a face material. Can be made.

The water-swellable material forming the water-swellable material layer 1 contains a water-swellable mineral and an organic adhesive, and further contains a water-swellable rubber as necessary. 1 type | formula or 2 or more types chosen from the group which consists of a quality agent and also gelled oil, a softener, and liquid resin as needed, and content of the said thermosensitive modifier is 1-15 mass% And the combined content of the gelled oil, the softener and the liquid resin is 45% by mass or less.
The water-swellable material has adhesiveness, a mineral having water-swellability, a component (A) containing one or more kinds selected from water-swellable rubber as required, asphalt, sensation A combination of a temperature modifier, an organic pressure-sensitive adhesive component (B) comprising a mixture containing one or more selected from gelling oil, softening agent, and liquid resin, if necessary. It is preferable that it is the composition which mixed uniformly.
The water-swellable material has a sufficient adhesive force, although its adhesiveness slightly decreases after swelling, so that the water-swellable material swells and sticks together when the water-stopping materials are joined together. And a continuous waterproof layer is formed, and the formed waterproof layer has the advantage of self-healing.

  As the mineral having water swellability, at least one kind of clay selected from natural or synthetic clay having water swellability is preferable. Such clay may be unmodified or modified, but is preferably at least one selected from the group consisting of bentonite, smectite (eg, hectorite), and swellable mica. Among these, bentonite is a particularly preferred mineral because it is a naturally occurring clay and is excellent in safety, stable in the long term, can retain a high water-stopping effect, and is inexpensive.

  The water-swellable material used in the present invention preferably contains 20 to 90% by mass, more preferably 30 to 80% by mass of the mineral having water swellability. If the amount of mineral having water swellability is too small, the swellability of the waterproof sheet is deteriorated, and it is difficult to obtain sufficient self-repairing and water-stopping effect. It is not preferable because physical properties are impaired and workability and adhesiveness are deteriorated.

  The water-swellable rubber that can be contained in the water-swellable material as needed is particularly limited as long as it is a mixture of a general water-absorbing resin and an elastomer having a property of swelling by absorbing water. not. Examples of water-absorbent resins include crosslinked vinyl acetate-acrylate polymers, isobutylene-maleate polymers, starch-acrylate polymers, vinyl alcohol-acrylate polymers, starch-acrylic fiber hydrolysates Examples thereof include polymers, crosslinked vinyl alcohol polymers, crosslinked CMC (carboxymethylcellulose), crosslinked products of polyacrylic acid neutralized products, urethane prepolymers, and the like. The water absorption amount of the water absorbent resin is preferably 10 to 300 mg per 1 g of dry mass.

  Elastomers include natural rubber, polyisoprene rubber, polybutadiene rubber, butadiene copolymer such as styrene-butadiene rubber (SBR), butadiene acrylonitrile rubber (NBR), chloroprene rubber, isobutylene / isoprene copolymer, polysulfide such as thiocol. Synthetic rubber, urethane rubber such as polyester urethane and polyether urethane, silicon rubber such as polydimethylsiloxane, fluoro rubber such as hexafluoropropylene / vinylidene fluoride copolymer, chlorosulfonated polyethylene, polyacrylic ester, acrylonitrile Various rubbers such as EPT rubber copolymerized to facilitate sulfur vulcanization molding of copolymers, ethylene propylene rubber, dicyclopentadiene, 1,4-hexadiene, ethylidene norbornene, etc. . A soft synthetic resin may be used in place of rubber, and silicone resin, vinyl chloride resin, fluororesin, vinylidene chloride resin and the like can be mentioned as examples.

The water-swellable rubber used in the present invention is preferably 5:95 to 50:50, more preferably 10:90 to 30:70 by mass ratio (water absorbent resin: elastomer) of the water absorbent resin and the elastomer. It is obtained by mixing and containing at a ratio. If the proportion of the water-absorbent resin is too small, the water-swellable rubber of the resulting water-swellable rubber will be reduced in water absorption / swellability. Or Preferable mixing is performed by uniformly dispersing the water absorbent resin in the elastomer by a mechanical method. Although there is no restriction | limiting in particular about the dispersion method, For example, it is good to use the mixing apparatus used normally, such as a roll and a Banbury mixer.
In the water-swellable rubber of the present invention, in addition to the essential components of the water-absorbent resin and elastomer, a vulcanizing agent, a vulcanization accelerator, a vulcanizing auxiliary, Fillers, reinforcing agents, softeners, plasticizers, colorants, ultraviolet absorbers, and the like can be added.

In the present invention, the organic pressure-sensitive adhesive contains one or more selected from asphalt, a temperature-sensitive modifier, and, if necessary, a gelled oil, a softener, and a liquid resin.
Examples of asphalt include straight asphalt, prone asphalt, and modified asphalt. Asphalt is preferably contained in the water-swellable material in an amount of 1 to 80% by mass. The penetration of asphalt is preferably 10 to 300.

The temperature-sensitive modifier means an additive for making the hardness of the water-swellable material less susceptible to temperature. By containing a temperature-sensitive modifier, the physical properties of the water-swellable material are not impaired, and the softening point can be increased (preferably 90 ° C. or higher).
The temperature-sensitive modifiers include styrene / butadiene copolymer, chloroprene copolymer, styrene / butadiene block copolymer, styrene / isoprene block copolymer, ethylene vinyl acetate copolymer, ethylene / ethyl acrylate copolymer. A styrene / butadiene block (SBS) copolymer is more preferable. The content of the temperature-sensitive modifier in the water-swellable material is 1 to 15% by mass, preferably 5 to 12% by mass. If the amount is less than 1% by mass, the heat resistance is not sufficiently improved. If the amount exceeds 15% by mass, the water-swellable composition becomes hard, and the self-repair function due to swelling is reduced.

  The gelled oil, softening agent, and liquid resin that can be contained as needed in addition to the essential components must be 45% by mass or less in the water-swellable composition. Above that, the softening point is significantly lowered due to the influence of gelled oil, softener and liquid resin, and it is easy to cause breathing. The content is more preferably 35% by mass or less. Gelling oils include base oils selected from mineral oils, natural or synthetic aromatic hydrocarbon oils, natural or synthetic aliphatic hydrocarbon oils, oils, waxes, fatty acids and their metal salts, organic bentonite And oils that have been gelled into a semi-solid or solid form by dispersing a thickener selected from polyurea and the like. Examples of the liquid resin include liquid polybutene, polypropylene, polyisobutylene, and polybutadiene. Examples of the softener include oils such as mineral oil, synthetic oil, and fatty oil, and plasticizers such as phthalic acid ester, aliphatic basic acid ester, and polyether ester.

  The organic pressure-sensitive adhesive is a component that gives the water-swellable material used in the waterproof sheet material of the present embodiment adhesiveness, shape retention and heat resistance, and prevents the mineral having water-swellability from being unevenly distributed or missing. In addition, the water-swellable material acts as a swelling speed adjusting agent for suppressing swelling of the water-swelling material more than necessary. The organic pressure-sensitive adhesive is preferably 10 to 80% by mass, more preferably 20 to 70% by mass in the water-swellable material.

  Moreover, the water-swellable material used for this embodiment can mix | blend various addition components as an arbitrary component as needed in the range which does not impair the objective of this invention other than the said component. Examples of the additive component include stabilizers (for example, anionic and nonionic surfactants, lead-based, zinc-based, calcium-based and other metal soaps), water conductivity-imparting agents (for example, inorganic water-absorbing substances, Anionic water-absorbing resin, nonionic water-absorbing resin, etc.), filler, tackifier, anti-aging agent, lubricant, colorant and the like. The content of these optional components in the water-swellable material is preferably 15% by mass or less.

  In preparing the water-swellable material used in this embodiment, there is no particular limitation on the order and method of adding and mixing the components. Moreover, the said water-swellable material can be manufactured by combining a fibrous substance as required, as long as the object of the present invention is not impaired. Examples of the fibrous material include glass fiber, carbon fiber, synthetic fiber (for example, nylon, vinylon, polypropylene, polyethylene, polyester, polyamide, etc.), cotton, silk, pulp fiber, steel fiber, and the like. By combining the fibrous substance, the shear strength and stiffness of the water-swellable material layer 1 can be improved. The content of these fibrous substances in the water-swellable material is preferably 15% by mass or less.

In the present invention, the thickness of the water-swellable material layer 1 is preferably 0.5 to 10 mm. Even with such a thin thickness, the roofing waterproof sheet material of the present invention can exhibit good waterproofing properties over a long period of time in a harsh environment.
Moreover, it is preferable that the water-swellable material used for the roofing waterproof sheet material of the present invention has a sufficient adhesive force. Although the water-swellable material having sufficient adhesive strength usually swells after water swelling, the water-swellable material layers 1 are integrated by the adhesive force when the waterproof sheet materials are joined to each other. And a continuous waterproof layer can be formed. The formed waterproof layer has self-healing properties.

  The expansion ratio of the water-swellable material used for the water-swellable material layer 1 is not particularly limited as long as it can swell with moisture and repair a defect such as a scratch, but after one month. If the swelling ratio is usually about 1.5 times or more, preferably 2 to 5 times, the water-swellable material can sufficiently exhibit a self-repairing function by water swelling. The water-swellable material has heat resistance capable of maintaining water-swellability under rooftop temperature conditions, and preferably has heat resistance defined in JIS A 6013.

  The roofing waterproof sheet material of the present invention preferably has a reinforcing material 2 as shown in FIG. The reinforcing material 2 gives the strength necessary for constructing the waterproof sheet material of the present invention to the entire waterproof sheet material, and the water-swellable material layer 1 is deformed to some extent by an external force due to the expansion and contraction of concrete when the waterproof sheet material is used. Suppressed to maintain the waterproof performance. The strength of the reinforcing material is preferably 80 N / cm or more in tensile strength and 15% or more in elongation in both the longitudinal direction and the width direction, more preferably 100 N / cm or more in elongation and 25% or more in elongation.

  The reinforcing material 2 is preferably made of a non-woven fabric, woven fabric, fiber, or kraft paper made of polyester resin, polyvinyl resin, or polyethylene resin.

  In the water-swellable material layer 1 of the waterproof sheet material for rooftop of the present invention, assuming that the A surface is located on the protective concrete side and the B surface is located on the building side of the building, the A surface side is as shown in FIG. In addition, a protective layer 3 may be provided for the purpose of protecting the water-swellable material layer 1. The protective layer 3 prevents foreign matter from adhering to the surface of the water-swellable material layer 1 during storage, transportation, and construction of the water-swellable material layer 1 having adhesive properties. By suppressing the tackiness, the handleability of the waterproof sheet material of the present invention is improved.

  The protective layer 3 used in the waterproof sheet material of the present invention is preferably a layer made of an alkali-decomposable resin film, a water-soluble resin film, silica sand, bentonite, smectite, or swellable mica, More preferably, the layer is made of In the case of using an alkali-decomposable resin film, the effect of preventing pre-swelling from water due to rainfall, etc. is also obtained, and the alkali-decomposable resin film is decomposed by the alkali content of concrete by placing protective concrete. The water-swellable material layer 1 and the protective concrete casing can be brought into close contact with each other without taking the trouble of peeling off. In addition, when silica sand is used, it is expected that the protective concrete is more closely adhered and integrated when it is placed.

  In the roofing waterproof sheet material of the present invention, the protective layer 3 or the release layer 4 can be provided on the B surface when the reinforcing material 2 is sandwiched as the core material in the center of the water-swellable material layer 1. FIG. 2 is a cross-sectional view showing an aspect in which a release layer 4 is provided on the B surface. The water-swellable material prevents foreign matter from adhering to the surface of the water-swellable material layer 1 at the time of storage, transportation and construction of the water-swellable material layer 1 having adhesiveness as with the protective layer 3 on the A side. By suppressing the adhesiveness of the layer 1, the handleability of the waterproof sheet material of the present invention is improved. Further, in the case of the release layer 4, the foreign body is prevented from adhering to the surface of the water-swellable material layer 1. It can be expected to assist in bonding with the. Any release layer 4 can be used as long as it has a release effect, and a commercially available release film (or release paper) can be used.

  In the roof waterproof sheet material of the present invention as shown in FIG. 2, the overlapping surface at the joint portion of the waterproof sheet material is usually the face A and the face B of the waterproof sheet material facing each other. At the time of later use, when an alkali-decomposable resin film or a water-soluble resin film is used for the protective layer 3, it is decomposed or dissolved as described above. The water-swellable material layer 1 can be continuously integrated, and the joint portion of the waterproof sheet material does not become a waterproof weak point. Further, when silica sand, bentonite, smectite, or water-swellable mica is used for the protective layer 3, the water-swellable material swells, so that the water-swellable material advances to the surface from the voids such as silica sand and the A side and B side. Will be in close contact and integrated. Further, bentonite, smectite, and water-swellable mica themselves swell and exhibit a water-stopping effect, and thus exhibit higher adhesion and water-stopping effect.

  Between the time when the roofing waterproof sheet material of the present invention is constructed on the rooftop of a building and the time when the protective concrete of the structure is constructed by placing the concrete, the waterproof sheet material is in contact with water for a long time due to rain or the like. In some cases, when the water-swellable material contains an organic pressure-sensitive adhesive, the swelling speed is suppressed by its action, but there is a possibility that the self-healing function may be deteriorated by starting to swell beyond the limit. In such a case, if the protective layer 3 is made of an alkali-decomposable resin film, the water-swellable material can be prevented from contacting with the A surface of the water-swellable material layer 1 until the concrete is placed. Since the self-repair function of the layer 1 can be prevented from being lowered and the roof-top protective concrete of the building is placed, the alkali-decomposable resin film is soon decomposed by the alkali component of the concrete. The water-swellable material layer 1 and the waterproofing layer in which the roof surface of the building is in close contact can be constructed without taking the trouble of removing the water.

  Examples of the alkali-decomposable resin film include aliphatic polyester resins such as polylactic acid resin. As for substances other than these, any substances can be used as long as they can block acidic or neutral water and can be decomposed by a strong alkali having a pH of 11 to 14. Moreover, about the thickness dimension of this alkali-decomposable resin film, about 5-100 micrometers is preferable. If the thickness is too thin, there is a high risk of breakage during construction of protective concrete, such as when placing concrete or during transportation. If it is too thick, it takes longer to decompose with alkali, leaving undecomposed parts remaining. This is not preferable.

  As a method of forming this alkali-decomposable resin film on the A surface of the water-swellable material layer 1, a fixed product of the alkali-decomposable resin film is attached to the A-side of the water-swellable material layer 1, or an alkali The alkali-decomposable resin is dissolved in an organic solvent capable of dissolving the decomposable resin so as to have an appropriate concentration, and this alkali-decomposable resin solution is applied to the surface A of the water-swellable material layer 1 (coating). Can be formed.

  Next, the present invention will be described in more detail based on the following examples, but the present invention is not limited to these examples.

Reference example 1
55 parts by mass of bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA), 15 parts by mass of modified asphalt obtained by adding 10 parts by mass of SBS copolymer to 5 parts by mass of 60/80 straight asphalt; Mineral oil-based process oil was blended at a ratio of 30 parts by mass and mixed well while heating to 160 ° C. using a disperser with a heating jacket to prepare a water-swellable material having adhesiveness, which was designated as Sample 1. .

Reference example 2
60 parts by weight of bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA), 30 parts by weight of modified asphalt obtained by adding 10 parts by weight of SBS copolymer to 20 parts by weight of 60/80 straight asphalt, and Mineral oil-based process oil was blended at a ratio of 10 parts by mass and mixed well while heating to 160 ° C. using a disper with a heating jacket to prepare a water-swellable material having tackiness, and this was used as Sample 2. .

Reference example 3
60 parts by weight of bentonite (Kunimine Industries Co., Ltd .; trade name Kunigel VA), 25 parts by weight of modified asphalt obtained by adding 5 parts by weight of SBS copolymer to 20 parts by weight of 60/80 straight asphalt; Mineral oil-based process oil was blended at a ratio of 15 parts by mass, and thoroughly mixed while heating to 160 ° C. using a disper with a heating jacket, to prepare a water-swellable material having tackiness, and this was designated as Sample 3 .

Reference example 4
60 parts by weight of bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA), 35 parts by weight of modified asphalt obtained by adding 2 parts by weight of SBS copolymer to 33 parts by weight of 60/80 straight asphalt; Mineral oil-based process oil was blended at a ratio of 5 parts by mass and mixed well while heating to 160 ° C. using a disper with a heating jacket to prepare a water-swellable material having tackiness, and this was used as Sample 4. .

Reference Example 5
Bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA) 50 parts by mass, water-absorbing rubber (100: 5 (mass ratio) mixture of chloroprene rubber and polyacrylic acid neutralized product) 5 parts by mass, penetration 15 parts by mass of modified asphalt made by adding 10 parts by mass of SBS copolymer to 5 parts by mass of 60/80 straight asphalt, and 30 parts by mass of mineral oil-based process oil, and using a kneader with a heating jacket The mixture was sufficiently mixed while being heated to 160 ° C. to prepare a water-swellable material having adhesiveness.

Reference Example 6
Bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA) 45 parts by mass, water-absorbent rubber (100: 10 (mass ratio) mixture of chloroprene rubber and polyacrylic acid neutralized product) 10 parts by mass, penetration 25 parts by mass of modified asphalt obtained by adding 10 parts by weight of SBS copolymer to 15 parts by weight of 60/80 straight asphalt and 20 parts by mass of mineral oil-based process oil are blended, and a kneader with a heating jacket is used. The mixture was sufficiently mixed while being heated to 160 ° C. to prepare a water-swellable material having tackiness.

Reference Example 7
Modified asphalt 32 obtained by adding 22.5 parts by mass of SBS copolymer to 55 parts by mass of bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA) and 9.9 parts by mass of penetration 60/80 straight asphalt 4 parts by weight and 12.6 parts by weight of mineral oil-based process oil are mixed thoroughly while heating to 160 ° C using a disper with a heating jacket to prepare a water-swellable material having adhesiveness This was designated as Sample 7.

Reference Example 8
35 parts by weight of bentonite (Kunimine Kogyo Co., Ltd .; trade name Kunigel VA), 15 parts by weight of modified asphalt obtained by adding 10 parts by weight of SBS copolymer to 5 parts by weight of 60/80 straight asphalt; Mineral oil-based process oil was blended at a ratio of 50 parts by mass, and thoroughly mixed while heating to 160 ° C. using a disper with a heating jacket, to prepare a water-swellable material having tackiness. .

Example 1
By using the samples 1 to 6 obtained in Reference Examples 1 to 6, the sheet materials 1 to 6 of the present invention example having a thickness of 2 mm were prepared. Similarly, using the samples 7 and 8 obtained in Reference Examples 7 and 8, comparative sheet materials 7 and 8 were prepared. The heat resistance of the sheet materials 1 to 8 and the softening point of the water-swellable material used therefor were measured by the following method. The measurement results are shown in Table 1 together with the composition (parts by mass) of the water-swellable material used.
<Heat resistance performance>
The measurement was performed based on the heat resistance performance test method of JIS A 6013 modified asphalt roofing.
<Softening point>
The measurement was performed based on the softening point test method (ring and ball type) of petroleum asphalt of JIS K 2207.

  Further, the water swelling ratio of Samples 1 to 8 was measured based on the vulcanized rubber immersion test method of JIS K 6258. The measurement results are shown in FIG.

  As shown in Table 1 and FIG. 3, the sheet material 7 had a low water swelling ratio over a long period of time because the content of the SBS copolymer in the water-swellable material was too large. Further, the sheet material 8 was inferior in heat resistance because the content of the process oil in the water-swellable material was too large, and the expansion ratio remained low for a long time. On the other hand, the sheet materials 1 to 6 were excellent in heat resistance and had a good water swelling ratio that exceeded 2 times within 30 days.

Example 2
The sample 1 prepared in Reference Example 1 was continuously poured in a heated and melted state on the surface of the release paper wound in a roll shape, and the thickness was adjusted to 1 mm. As a core material for reinforcing the central portion of the structure, a polyethylene nonwoven fabric sheet (thickness 1 mm) wound in a roll shape is pasted, and the sample 1 is continuously poured in a heated and melted state on the polyethylene nonwoven fabric sheet so that the thickness is 1 A film made of polylactic acid resin (thickness 25 μm) wound up in a roll shape as a protective layer was attached to the laminated sheet and a waterproof sheet material having a laminated structure was prepared. This was cut into a width of 200 mm to obtain a strip-like waterstop material sample 9.
Further, as a comparative example, a waterproof sheet material having a laminated structure was prepared in the same manner as in the manufacture of the sample 9 except that the sample 1 was changed to straight asphalt having a penetration of 60/80. This was cut into a width of 200 mm to obtain a strip-shaped waterstop material sample 10.

Test example 2
<Water-stop performance test>
Using the samples 9 and 10 of Example 2, the following water-stop performance test was performed.
The apparatus and specimen used for a water-stop performance test are demonstrated with reference to the schematic diagram shown in FIG. Considering the state of construction of the waterproof sheet material, adjust the size to a cylindrical acrylic case (5) with a diameter of about 15 cm, and use a filter paper (8) between the waterproof sheet (6) and the drain port (7) to form a metal mesh sheet ( 9) Insert a material sandwiched between them, and bond the acrylic case (5) and the strip-shaped water-stopping material (6) with the caulking material (10) so that water cannot be transmitted along the acrylic case (5).
Then, spread the silica sand (11) over the waterproof sheet (6), allow water to spread over the entire surface, install a spacer (12), suppress deformation due to swelling of the waterproof sheet (6), and Avoid gaps between them. A metal lid (13) is installed on the acrylic case (5) and fixed with a flange (14). Then, water is poured from the water inlet (15), nitrogen gas (16) is filled and pressure is applied, and water leakage from the water outlet (7) is confirmed.
Here, as the waterproof sheet (6), a sample 9-A in which the above-described sample 9 is provided with a slit that is regarded as a defective portion with a cutter is referred to as a sample 9-A, and a superposed sheet is referred to as a sample 9-B. In addition, a sample 10-A in which the above-described sample 10 was provided with a slit that was regarded as a defective portion was referred to as a sample 10-A, and a sample 10-B in which the slits were superimposed. In Samples 9-B and 10-B, the overlapped portion was not adhered, and the alkali-decomposable resin film was not peeled off because it was not under concrete casting conditions, so that it was not peeled off.
By injecting nitrogen gas, the water pressure was maintained at 0.3 MPa, and water leakage from the drainage port (7) was confirmed by elapsed time. The results are shown in Table 2.

As is clear from the results shown in Table 2, in the samples 9-A and 9-B of the present invention, when there is a slit or a lap portion as a defect, swelling has just started in the initial stage of pressurization. In order to close the gap, the water leaked. However, as time passed, the voids were blocked by swelling and water leakage was not confirmed, and the self-healing function for the defect portion was obtained. On the other hand, Samples 10-A and 10-B had no effect of closing the air gap and leaked throughout.
As described above, the waterproof sheet material of the present invention uses a water-swellable material having heat resistance and has a defect self-repairing function, and thus is practically suitable as a waterproof sheet material for rooftops. .

It is sectional drawing which shows one embodiment of the waterproof sheet material for roofs of this invention. It is sectional drawing which shows another embodiment of the waterproof sheet material for roofs of this invention. 6 is a graph showing measurement results of Test Example 1. It is a schematic diagram explaining the apparatus for performing the water stop performance confirmation test of Test Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water-swellable material layer 2 Reinforcing material 3 Protective layer 4 Peeling layer 5 Acrylic case 6 Waterproof sheet 7 Drain port 8 Filter paper 9 Metal mesh sheet 10 Caulking material 11 Silica sand 12 Spacer 13 Metal lid 14 Flange 15 Water inlet 16 Nitrogen gas

Claims (6)

  A rooftop waterproofing sheet material using a water-swellable material that exhibits a self-repair function by water swelling with respect to the defect portion, the water-swellable material containing a mineral having a water-swelling property and an organic adhesive. The organic pressure-sensitive adhesive contains one or more selected from the group consisting of asphalt, a temperature-sensitive modifier, and optionally a gelled oil, a softener, and a liquid resin, and the temperature-sensitive A modifier is contained in the water-swellable material in an amount of 1 to 15% by mass, and the combined content of the gelled oil, the softener, and the liquid resin is 45% by mass or less in the water-swellable material. A waterproof sheet material for rooftops.   The roofing waterproof sheet material according to claim 1, wherein the water-swellable material further contains a water-swellable rubber.   The rooftop waterproof sheet material according to claim 1 or 2, wherein the water-swellable mineral is at least one selected from the group consisting of bentonite, smectite, and swellable mica.   The roofing waterproof sheet material according to claim 1, comprising the water-swellable material and a reinforcing material.   5. The roofing waterproof sheet material according to claim 4, wherein the reinforcing material is a nonwoven fabric, a woven fabric, a fiber, or a kraft paper made of a polyester resin, a polyvinyl resin, or a polyethylene resin.   The rooftop according to any one of claims 1 to 5, wherein a protective layer made of silica sand, bentonite, smectite, swelling mica, alkali-decomposable resin film, or water-soluble resin film is provided on the surface. Tarpaulin material.

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