JP4849367B2 - Liquid adhesive, waterproof sheet, and bonding method of waterproof sheet - Google Patents

Description

  The present invention relates to a waterproof sheet used for waterproofing of buildings, greening of a roof, water shielding of a pond, and the like, and a liquid adhesive used for bonding of the waterproof sheet and a method of bonding the waterproof sheet It is.

  Waterproofing work on rooftops of buildings and other buildings, waterproofing of water tanks for rooftop greening, and waterproofing of ponds such as reservoirs are carried out by laying multiple waterproof sheets. Thus, when performing the construction which lays a waterproof sheet, it is necessary to overlap and adjoin the adjacent waterproof sheet.

  In joining the waterproof sheet in this way, conventionally, the adhesive was applied to the surface of the joint portion of the waterproof sheet and adhered, but in the construction method in which the liquid adhesive is applied and adhered, Adhesives may vary due to under- or over-time of the agent open time (drying time), especially because the open time varies depending on weather conditions such as temperature, making it difficult to perform construction stably. There is.

  Therefore, bonding of the waterproof sheet is performed by heat sealing. FIG. 2 (a) shows an example thereof, a waterproof sheet A is produced by thermocompression bonding a thermoplastic resin film 6 on the back surface of the waterproof sheet body 1, and forming an adhesive layer 2, and The adhesive layer 2 of the thermoplastic resin film 6 is melted by overlapping and heating the end portions of the waterproof sheet A, and the overlapping portion of the waterproof sheet A is heat-sealed (see Patent Document 1).

  However, unevenness 3 is formed on the front and back surfaces of the waterproof sheet main body 1 by providing a pattern such as a canvas pattern for suppressing reflection of light and preventing slipping of walking. For this reason, in forming the adhesive layer 2 on the waterproof sheet body 1 by stacking the thermoplastic resin film 6 on the back surface of the waterproof sheet body 1 as shown in FIG. As described above, the air 7 is caught between the concave portion 3 a of the unevenness 3 of the waterproof sheet body 1 and the adhesive layer 2 made of the thermoplastic resin film 6, and the adhesive layer 2 is formed in close contact with the waterproof sheet body 1. difficult. Accordingly, when the waterproof sheet A is heat-sealed as shown in FIG. 2 (a), the air 7 that has been inhaled may expand, causing a bulge or peeling at the joint, which increases the joint strength. There was a problem.

  In addition, when a waterproof sheet is laid on the rooftop of a building or the like, there may be a place where the waterproof sheet is joined to a metal plate around a drainage groove or other accessory, apart from joining the waterproof sheets. Stainless steel, aluminum, copper, galvanized steel plate, etc. are common as the type of metal plate, but it is difficult to bond a waterproof sheet to a metal plate with the adhesive layer of a thermoplastic resin film as described above. It is.

  Furthermore, there is also a method of joining the waterproof sheets by heating and pressure bonding with a hot melt adhesive interposed between the waterproof sheets (see Patent Document 2). In Patent Document 2, a hot melt gun is used in addition to a method of using a hot melt adhesive as a sheet and interposing between waterproof sheets (in this case, there is a problem of air entrainment similar to the above). It is also disclosed to extrude a hot melt adhesive between the waterproof sheets and heat-press. However, even when the hot melt adhesive in a molten state is extruded onto the waterproof sheet with the hot melt gun in this way, the melt viscosity of the hot melt adhesive is high, so that it is sufficient for the recess 3 a of the unevenness 3 of the waterproof sheet body 1. In this case as well, it is impossible to completely prevent air from being caught, and the above problem cannot be solved.

  On the other hand, rooftop greening has a structure in which soil for planting vegetation is laid on the rooftop, and a water storage tank is installed underneath to supply moisture to the vegetation. It is stored and water is supplied from the storage tank to the soil using capillary action. A waterproof sheet A is laid on the bottom of the water tank so that the bottom of the water tank is insulated, and the connection of the waterproof sheet A is performed in the same manner as in FIG. Here, normally, a root-proof nonwoven fabric is placed under the soil, so that the roots of plants planted in the soil do not reach the water tank, but in reality some roots. Comes down to the water tank. When the root of the plant descends to the water storage tank and reaches the waterproof sheet A in this way, it enters so as to push the adhesive layer 2 between the overlapping joints of the waterproof sheet A, and peels off the joint of the waterproof sheet A. It has a problem that there is a risk of causing it to occur.

  Therefore, as shown in FIG. 2B, the joint portion of the waterproof sheet A is covered with the seal layer 4 (see, for example, Patent Document 3). In this way, the joint portion of the waterproof sheet A is sealed with the seal layer 4, thereby preventing plant roots from entering between the joint portions of the waterproof sheet A.

However, also in this case, when the unevenness 3 such as the canvas is formed on the surface of the waterproof sheet main body 1, air is caught between the recess 3 a of the unevenness 3 and the seal layer 4, and the seal layer 4 is adhered. It is difficult. Therefore, plant roots may enter between the joint portions of the waterproof sheet A from the gap where the seal layer 4 is not in close contact, and the above problem cannot be solved completely.
Japanese Patent Publication No.57-32949 JP 60-127331 A JP 2002-146341 A

  The present invention has been made in view of the above points, and an object thereof is to provide a liquid adhesive capable of forming a hot-melt adhesive layer or forming a seal layer without air being caught. It is another object of the present invention to provide a waterproof sheet that can be bonded with high strength and a method for bonding the waterproof sheet.

The liquid adhesive according to claim 1 of the present invention contains a carboxyl-modified polyethylene and a thermoplastic maleic acid-containing resin that are hot melt polymers , a chloroprene rubber that is a reinforcing polymer , and diphenylmethane diisocyanate that is a cross-linking agent. together are formed in a solvent-concentration of the hot melt polymer is 20 to 40 wt%, and wherein said hot-melt the thermoplastic maleic acid-containing resin der Rukoto 20 to 40 mass% in the polymer To do.

The solvent- type liquid adhesive has a high fluidity, and the liquid adhesive is applied in a state where it is sufficiently intruded into the concave portion 3a of the concave and convex portion 3 so that the hot melt adhesive layer 2 and the seal are not entrained with air. The layer 4 can be formed.
Further, it is possible to obtain higher bonding strength of the waterproof sheet A by the hot melt adhesive 2 and the seal layer 4 formed of a liquid adhesive.
In addition, the thermoplastic maleic acid-containing resin has good adhesion to metal, and can obtain high bonding strength not only at the joint between the waterproof sheets A but also at the joint between the waterproof sheet A and the metal plate. .

The invention of claim 2, in claim 1, the amount of the crosslinking agent is characterized in that from 5 to 30% by mass in solid content ratio with respect to the hot melt polymer.

  According to this invention, the bonding strength of the waterproof sheet A by the hot melt adhesive 2 and the seal layer 4 formed of a liquid adhesive can be further increased.

Waterproof sheet according to claim 3 of the present invention, there is provided a waterproof sheet A to be joined by heat sealing overlapping the junction portions, at least on the surface of the joint portion of the waterproof sheet body 1, claim The hot melt adhesive layer 2 is formed by applying the liquid adhesive described in 1 or 2 and drying it.

Since the solvent- type liquid adhesive according to claim 1 or 2 has high fluidity, the liquid adhesive is applied in a state in which the waterproof sheet main body 1 is sufficiently penetrated into the recess 3a even when the unevenness 3 is formed. The hot melt adhesive layer 2 can be formed in a state of being completely adhered to the surface of the waterproof sheet main body 1 without causing air to bite, and the waterproof sheet A is heat-sealed and joined without the influence of air. It is something that can be done. Moreover, by adding a reinforcing polymer and a crosslinking agent to the adhesive in addition to the hot melt polymer, the adhesive strength can be increased, and the cohesive force at the time of fusion of the hot melt polymer can be increased, resulting in high bonding. The waterproof sheet A can be joined with strength.

Method of joining the waterproof sheet according to claim 4 of the present invention, the waterproof sheet A by claim 3 overlapping the junction portions of the waterproof sheet A according to, by heating to melting the hot melt adhesive layer 2 The above-mentioned joint part is heat-sealed.

  According to the present invention, it is possible to perform heat fusion by the hot melt adhesive layer 2 formed by being in close contact with the surface of the waterproof sheet body 1 without causing air to be caught, and there is no influence of swelling or the like caused by air. The waterproof sheet A can be bonded with high bonding strength. Moreover, the reinforcing polymer and the crosslinking agent contained in the hot melt adhesive layer 2 in addition to the hot melt polymer can increase the adhesive strength and increase the cohesive force when the hot melt polymer is fused. The waterproof sheet A can be bonded with high bonding strength.

Method of joining the waterproof sheet according to claim 5 of the present invention, overlapping the junction portions of the waterproof sheet A with the adhesive layer 2 is formed by providing a surface of at least the joint of the waterproof sheet body 1, with the adhesive layer 2 wherein with joining the joint portions of the waterproof sheet a, between the joint portion of the waterproof sheet a was superposed and subjected to the top surface of the waterproof sheet a of the end face and below the upper tarpaulin a to claim 1 or 2 The liquid adhesive described above is applied, and the liquid adhesive is heated and cross-linked for sealing.

  According to the present invention, the seal layer 4 can be formed in a state of being completely adhered to the surface of the waterproof sheet main body 1 without air being caught, and the seal layer 4 can be formed without fear of poor adhesion due to air. The joint portion of the waterproof sheet A can be coated, and the adhesive strength of the seal layer 4 can be increased by the reinforcing polymer and the crosslinking agent contained in addition to the hot melt polymer. The cohesive force at the time of polymer fusion can be increased, and the joint portion of the waterproof sheet A can be firmly covered with the seal layer 4. Therefore, the sealing layer 4 can reliably prevent the roots of the plant from entering between the joint portions of the waterproof sheet A.

Since the solvent- type liquid adhesive has high fluidity, the liquid adhesive can be applied in a state in which the waterproof sheet main body 1 is sufficiently intruded into the concave portion 3a even if the concave and convex portions 3 are formed, and the air is bitten. The hot melt adhesive layer 2 can be formed in a state of being completely adhered to the surface of the waterproof sheet main body 1 without being trapped, and can be completely formed on the surface of the waterproof sheet main body 1 without being intruded by air. The seal layer 4 can be formed in a state of being in close contact. For this reason, when the waterproof sheet A is heat-sealed by the hot melt adhesive layer 2 and bonded, the waterproof sheet A can be bonded with high bonding strength without the influence of blistering caused by air, and the adhesion failure due to air, etc. The joint portion of the waterproof sheet A can be covered with the seal layer 4 without fear of the above. Moreover, the reinforcing polymer and the crosslinking agent contained in the hot melt adhesive layer 2 in addition to the hot melt polymer can increase the adhesive strength and increase the cohesive force when the hot melt polymer is fused. The waterproof sheet A can be bonded with high bonding strength, and the bonded portion of the waterproof sheet A can be firmly covered with the seal layer 4.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The liquid adhesive according to the present invention contains a hot melt polymer as a base polymer, a reinforcing polymer, and a crosslinking agent that crosslinks the hot melt polymer, and is formed into a solvent type or an aqueous emulsion type. The waterproof sheet A according to the invention is formed by applying the liquid adhesive to one side of the waterproof sheet body 1 and providing the hot melt adhesive layer 2.

  In the liquid adhesive according to the present invention, the hot melt polymer is a thermoplastic resin or a thermoplastic elastomer and is not particularly limited. However, in the case of a solvent-type liquid adhesive, for example, polyethylene or polypropylene is used. Examples thereof include polyolefin resins, chlorinated polyolefin resins such as chlorinated polyethylene and chlorinated polypropylene, carboxyl modified polyolefin resins such as carboxyl modified polyethylene and carboxyl modified polypropylene, and ethylene-vinyl acetate copolymer resins. In the case of an aqueous emulsion type liquid adhesive, for example, a polyolefin resin emulsion similar to the above, a chlorinated polyolefin resin emulsion similar to the above, a carboxyl modified polyolefin resin emulsion similar to the above, a carboxyl modified chlorine, and the like. Polyolefin emulsion, SBR emulsion, chlorosulfonated polyethylene emulsion, and ethylene-vinyl acetate copolymer resin emulsion.

Further, as part of the hot melt polymer, a thermoplastic maleic acid-containing resin obtained by modifying the above thermoplastic resin or thermoplastic elastomer with maleic acid can be used. The thermoplastic maleic acid-containing resin has good adhesion to metal, and by using the thermoplastic maleic acid-containing resin as a part of the hot melt polymer, not only the joint between the waterproof sheets A but also the waterproof sheet A and the metal in which it is possible to obtain a high junction strength even at the joint of the plate. Specific examples of the thermoplastic maleic acid-containing resin include vinyl chloride / vinyl acetate copolymers containing maleic acid, styrene / butadiene copolymers containing maleic acid, and the like. Maleic San含Yes ratio in the thermoplastic maleate-containing resin is not particularly limited, is preferably about 1 to 2 wt%. The thermoplastic maleic acid-containing resin is preferably used in the range of 20 to 40% by mass in the entire hot melt polymer. By using the thermoplastic maleic acid-containing resin in this range, It is possible to obtain a high effect of increasing the bonding strength.

In the case of a solvent-type liquid adhesive, the concentration of the hot-melt polymer as a base polymer is in the range of 20 to 40% by mass. In the case of an aqueous emulsion-type liquid adhesive, the hot-melt polymer as a base polymer as the concentration is in the range of 20 to 50 wt%, prepare a liquid adhesive by blending hot-melt polymer. When the concentration of the hot melt polymer is less than these ranges, the adhesive strength to the waterproof sheet body 1 is insufficient, and conversely, when the concentration of the hot melt polymer exceeds these ranges, the viscosity of the liquid adhesive increases and the waterproof There is a possibility that the inflow property of the liquid adhesive into the recess 3a of the unevenness 3 of the sheet body 1 is deteriorated.

Further, the reinforcing polymer, the improvement of adhesion to the tarpaulin main body 1, is blended in order to increase the strength of the joint to improve the cohesive strength of the hot melt polymer during thermal fusion. The reinforcing polymer in the present invention, but are not particularly limited, for example, in the case of solvent-based liquid adhesives, for example alkylphenol resins, terpene phenol resins, rosin glycerin ester and rosin pentaerythritol ester, partial or complete Disproportionated rosin glycerin ester, partially or fully disproportionated rosin pentaerythritol ester, hydrogenated rosin glycerin ester, hydrogenated rosin pentaerythritol ester and other rosin ester resins, chloroprene rubber, carboxyl modified chloroprene rubber, halogenated butyl rubber, chlorosulfone And polyethylene and polyisobutylene. In the case of an aqueous emulsion type liquid adhesive, for example, an acrylic resin emulsion, a rosin ester resin emulsion similar to the above, a terpene phenol resin emulsion, a chloroprene latex, a natural rubber latex, an isoprene latex, an SBR latex, and an IR latex. Can be mentioned.

The reinforcing polymer is preferably added in the range of 5 to 30 parts by weight per 100 parts by weight hot-melt polymers.

  In addition, the crosslinking agent reacts with the side chain of the hot melt polymer such as a carboxyl group at the time of heat fusion to crosslink the hot melt polymer, and the cohesive force of the hot melt polymer at the time of heat fusion is increased. It is possible to prevent the cohesive failure of the hot melt adhesive layer 2 fused at the joint, and to improve the heat resistance and water resistance of the hot melt adhesive layer 2 over time. It can be raised. In the present invention, the crosslinking agent is not particularly limited, but in the case of a solvent-type liquid adhesive, for example, isocyanates such as blocked isocyanate, and polyamide can be mentioned. In the case of a water-based emulsion type liquid adhesive, for example, an epoxy resin, a blocked isocyanate emulsion, a polycarbodiimide-based water-soluble polymer, and an oxazoline group-containing water-soluble polymer can be used.

  The amount of the crosslinking agent is preferably set in the range of 5 to 30% by mass with respect to the hot melt polymer. When the blending amount of the crosslinking agent is less than 5% by mass, the hot melt polymer cannot be sufficiently crosslinked, and the effect of improving the bonding strength cannot be sufficiently obtained. On the other hand, when the blending amount of the crosslinking agent exceeds 30% by mass, the crosslinking reaction proceeds too quickly, and the heat-sealing property to the waterproof sheet body 1 may be lowered.

  In the case of a solvent-type liquid adhesive, the solvent is not particularly limited, and industrial gasoline, N-hexane, toluene, ethylcyclohexane, dimethylcyclohexane, and the like can be used.

  On the other hand, as the waterproof sheet main body 1 in the present invention, any of those conventionally used can be used. For example, a vulcanized rubber-based sheet prepared by blending EPDM (EPT) or butyl rubber alone or blended. Or a PVC sheet etc. can be illustrated. Further, the waterproof sheet body 1 can be produced as a composite sheet in which these are reinforced with fibers or the like. From the viewpoint of preventing wrinkles due to shrinkage when the waterproof sheet A is joined as described later, the composite sheet is more preferable. preferable. Examples of fibers used for the composite include glass fibers and polyester fibers conventionally used for vulcanized rubber and PVC. The thickness of the waterproof sheet body 1 is not particularly limited, but is preferably in the range of 1.0 to 3.0 mm. If the thickness is less than 1.0 mm, the traumatic property is low and breakage or the like is likely to occur. Conversely, if the thickness exceeds 3.0 mm, the coating becomes heavy and hard, and the workability deteriorates.

And the liquid adhesive of said composition is apply | coated to the single side | surface (mainly back side surface) of the waterproof sheet main body 1, it dries, and the hot-melt-adhesive layer 2 is applied to the single side | surface of the waterproof sheet main body 1 like FIG. By forming, the waterproof sheet A with the hot-melt adhesive layer 2 can be obtained. The hot melt adhesive layer 2 may be provided on the entire surface of the waterproof sheet main body 1, or may be provided only at a joint portion when the waterproof sheets A are joined together, such as an end portion of the waterproof sheet main body 1. Here, unevenness 3 is formed on the front and back surfaces of the waterproof sheet main body 1 in a pattern such as a canvas, but since the liquid adhesive has high fluidity, the liquid adhesive is applied to the waterproof sheet main body 1. enter easily into the concave portion 3a of the irregularities 3, without such an air biting between the waterproof sheet body 1, while being in close contact to the surface of the waterproof sheet body 1 as shown in FIG. 1 (b) Thus, the hot melt adhesive layer 2 can be formed.

  Next, when laying a plurality of waterproof sheets A prepared as described above, waterproofing the roof of buildings such as buildings, waterproofing of water storage tanks for rooftop greening, and waterproofing of ponds such as reservoirs In joining the adjacent waterproof sheets A, the end portions which are the joint portions of the waterproof sheet A are overlapped with each other, and this portion is heated with hot air or the like to melt the hot melt adhesive layer 2 of the joint portion. The waterproof sheet main body 1 of the waterproof sheet A stacked as shown in FIG. 2A is fused with the melted hot melt adhesive layer 2 so that the waterproof sheet A can be joined.

Here, as described above, the hot melt adhesive layer 2 is formed in a state in which the hot melt adhesive layer 2 is completely in close contact with the waterproof sheet main body 1 without causing air to bite. The entrained air does not expand, can prevent the occurrence of blistering or peeling at the joint, and can obtain a high joint strength by heat fusion. . In addition to the hot melt polymer for heat fusion, the hot melt adhesive layer 2 contains a reinforcing polymer and a crosslinking agent, so that the adhesive strength can be increased and the hot melt polymer can be fused. The cohesive force at the time can be increased, the cohesive failure of the hot melt adhesive layer 2 fused at the joint portion can be prevented, and the waterproof sheet A can be joined with high joint strength. Therefore, when the tensile test is performed after joining the waterproof sheet A in this way, the joining is not so high in the portion of the hot melt adhesive layer 2 of the joined portion that the waterproof sheet body 1 itself is destroyed. Strength can be obtained. In addition, when the hot melt adhesive layer 2 contains a thermoplastic maleic acid-containing resin as a part of the hot melt polymer, it is high not only at the joint between the waterproof sheets A but also at the joint between the waterproof sheet A and the metal plate. Bonding strength can be obtained.

  If the hot melt adhesive layer 2 is previously formed on the waterproof sheet main body 1 and carried into a waterproof construction site for use, the number of work steps such as adhesive application at the construction site can be reduced. There is something you can do. However, the present invention is not limited to this, and the hot melt adhesive 2 may be formed on the waterproof sheet body 1 at the construction site. In particular, when the hot melt adhesive layer 2 is formed by applying a water-based emulsion type liquid adhesive, the hot melt adhesive layer 2 can be easily formed at the construction site without any danger of ignition or environmental problems. It can be done.

  In addition, when the waterproof sheet A is joined as shown in FIG. 2A by fusing together the overlapping joints of the waterproof sheet main body 1 with the adhesive layer 2 as described above, the seal of the joint part of the waterproof sheet A is sealed. When performing the above, the liquid adhesive according to the present invention having the above composition is applied between the end portions of the upper waterproof sheet body 1 and the upper surface of the lower waterproof sheet body 1 between the joined portions of the overlapped waterproof sheets A. The sealing layer 4 is formed by coating, heating and drying and crosslinking, and the sealing layer 4 covers between the joint portions of the waterproof sheet A as shown in FIG. Heating when the applied liquid adhesive is heated to form the seal layer 4 may be performed by a method such as a method using hot air or a hot plate, but considering the workability at the construction site. A method using hot air is preferable. The heating condition is a value obtained by multiplying the heating temperature (unit: ° C.) and the heating time (unit: second) and is preferably in the range of 4000 to 12000. If the heating temperature is set to a high temperature, crosslinking is performed with a short heating. Even if the heating temperature is low, crosslinking can be carried out by heating for a long time. When this heating temperature (° C.) × heating time (seconds) is less than 4000, crosslinking is insufficient and sufficient adhesion and strength of the seal layer 4 cannot be obtained. Therefore, the constituent material of the seal layer 4 may be decomposed, and the adhesiveness and physical properties may be deteriorated. The heating temperature may be set so that heating temperature (° C.) × heating time (seconds) is in the range of 4000 to 12000, but it is usually preferable to heat at a temperature exceeding 100 ° C.

Here, even if irregularities 3 in a pattern such as canvas th are formed on the front and back surfaces of the tarpaulin main body 1, since the liquid adhesive is easily enters the concave portion 3a of the irregularities 3 by its fluidity, waterproof sheet body The sealing layer 4 can be formed in a state in which the air tightly adheres to the surface of the waterproof sheet body 1 without causing air to bite into the body. Moreover, it is crosslinked by heating to increase the hardness, and the strength of the seal layer 4 is increased. Accordingly, the sealing layer 4 can completely prevent plant roots from entering between the joint portions of the waterproof sheet A, and the joint portion of the waterproof sheet A is peeled off by the entrance of the plant roots. Can be reliably prevented, and the waterproof sheet A can be joined with high strength.

In addition, when the waterproof sheet A formed by providing the hot melt adhesive layer 2 with the liquid adhesive according to the present invention on the waterproof sheet body 1, the adhesive composition of the seal layer 4 and the adhesive layer 2 is the same. Therefore, it is preferable because the sealing layer 4 is integrated with the adhesive layer 2 to increase the bonding force. However, the adhesive layer 2 is not limited to the one formed with the liquid adhesive according to the present invention, and is an adhesive layer other than the liquid adhesive according to the present invention, for example, a film as shown in Patent Document 1 described above. As for the waterproof sheet A formed with 2, the effect of preventing the invasion of plant roots is similarly obtained by sealing the joint portion of the waterproof sheet A with the sealing layer 4 formed with the liquid adhesive according to the present invention. It is something that can be done.

  Next, the present invention will be specifically described with reference to examples.

(Ref Reference Example 1)
Carboxyl-modified polyethylene as a hot melt polymer, chloroprene latex as a reinforcing polymer, polycarbodiimide as a cross-linking agent, 80 parts by weight of carboxyl-modified polyethylene, 20 parts by weight of chloroprene latex, and 15 parts by weight of polycarbodiimide are blended. A water-based emulsion type liquid adhesive was prepared by dispersing in water such that the concentration of the modified polyethylene was the value shown in Table 1.

As the waterproof sheet, a glass fiber reinforced type EPDM vulcanized sheet (thickness: 1.5 mm), on which both sides of the front and back surfaces are formed, 300 g of the above liquid adhesive is applied to the entire back surface of the waterproof sheet. A hot melt adhesive layer was formed by applying at a coating amount of / m ² (dry weight) and drying at 100 ° C. for 5 minutes.

  The two waterproof sheets having the hot-melt adhesive layer formed thereon are overlapped with a width of 4 cm as described above, and heat-sealed by blowing hot air at 400 ° C. for 5 to 6 seconds on the overlapped joints. Were joined. For comparison, an oil-based bond (chloroprene rubber (solid content: 25% by mass), solvent: toluene and N-hexane) is used, and this oil-based bond is applied to the joint portion of the waterproof sheet not forming the hot melt adhesive layer. Then, after drying at room temperature for 30 minutes, two waterproof sheets were overlapped at the joint and joined (Comparative Example 1).

  After joining the waterproof sheet as described above and curing at room temperature for 1 day, the normal adhesive strength of the joined part of the waterproof sheet was measured. The measurement was performed by measuring 180 ° C. peeling peeling adhesive force under the condition of 200 mm / min. The results are shown in Table 1.

As seen in Table 1, it is confirmed that the reference example 1 has high adhesive strength and excellent bonding strength. Further, it is confirmed that the concentration of the hot melt polymer in the liquid adhesive is preferably in the range of 20 to 50% by mass.

(Ref Reference Example 2)
Carboxyl-modified polyethylene as a hot melt polymer, chloroprene rubber as a reinforcing polymer, diphenylmethane diisocyanate as a crosslinking agent, 80 parts by weight of carboxyl-modified polyethylene, 20 parts by weight of chloroprene rubber, and 15 parts by weight of isocyanate are blended, and these are carboxyl-modified. A solvent-type liquid adhesive was prepared by dissolving in toluene so that the polyethylene concentration was the value shown in Table 2.

Then, in the same manner as in Reference Example 1, a liquid adhesive was applied to the back surface of the waterproof sheet at a coating amount of 300 g / m ² (dry weight) and dried at room temperature for 30 minutes to form a hot melt adhesive layer. Moreover, the waterproof sheet formed in this way hot-melt adhesive layer, subjected to bonding by heat fusion in the same manner as in Reference Example 1, was measured ordinary state adhesive strength of the joint portion of the waterproof sheet in the same manner as in Reference Example 1 . The results are shown in Table 2.

As seen in Table 2, it is confirmed that the reference example 2 has high adhesive strength and excellent bonding strength. Further, it is confirmed that the concentration of the hot melt polymer in the liquid adhesive is preferably in the range of 20 to 40% by mass.

(Reference Example 3)
As in Reference Example 1 above, carboxyl-modified polyethylene as a hot melt polymer, chloroprene latex as a reinforcing polymer, polycarbodiimide as a crosslinking agent, 80 parts by mass of carboxyl-modified polyethylene, 20 parts by mass of chloroprene latex, and polycarbodiimide A water-based emulsion type liquid adhesive was prepared by blending so that the solid content ratio with respect to the carboxyl-modified polyethylene was a numerical value shown in Table 3 and dispersing them in 330 parts by mass of water. For comparison, a water-based emulsion type liquid adhesive was prepared without blending polycarbodiimide as a crosslinking agent (Comparative Example 2).

In the same manner as in Reference Example 1, a liquid adhesive was applied to the back surface of the waterproof sheet to form a hot melt adhesive layer. Moreover, the waterproof sheet formed in this way hot-melt adhesive layer, subjected to bonding by heat fusion in the same manner as in Reference Example 1, was measured ordinary state adhesive strength of the joint portion of the waterproof sheet in the same manner as in Reference Example 1 . The results are shown in Table 3.

As seen in Table 3, it is confirmed that the material of Reference Example 3 has high adhesive strength and excellent bonding strength. Moreover, it is confirmed that the blending amount of the crosslinking agent in the liquid adhesive is preferably in the range of 5 to 30% by mass with respect to the hot melt polymer.

(Example 4 and Reference Example 4 )
As a hot melt polymer, a mixture of carboxyl-modified polyethylene and a block copolymer of styrene and butadiene containing maleic acid in a ratio shown in Table 4 is used, and chloroprene rubber is used as a reinforcing polymer and diphenylmethane diisocyanate is used as a crosslinking agent. 80 parts by mass of hot melt polymer, 20 parts by mass of chloroprene rubber, and 15 parts by mass of diphenylmethane diisocyanate were dissolved in toluene so that the concentration of the hot melt polymer was 30% by mass. A liquid adhesive was prepared.

Then, in the same manner as in Reference Example 1, a liquid adhesive was applied to the back surface of the waterproof sheet at a coating amount of 300 g / m ² (dry weight) and dried at room temperature for 30 minutes to form a hot melt adhesive layer. Further, the waterproof sheet having the hot melt adhesive layer formed in this manner is superposed on a stainless steel metal plate with a width of 4 cm, and bonding is performed by blowing hot air of 40 ° C. on the superposed joint portion for 5 to 6 seconds. It was. And the normal-state adhesive force of the junction part of the waterproof sheet was measured like the reference example 1. FIG. The results are shown in Table 4.

  As seen in Table 4, the maleic acid-containing thermoplastic resin is improved by blending the maleic acid-containing thermoplastic resin as a part of the hot melt polymer. In particular, the maleic acid-containing thermoplastic resin in the hot melt polymer is improved. It is confirmed that a high bonding strength can be obtained by blending in a range of 20 to 40% by mass.

BRIEF DESCRIPTION OF THE DRAWINGS An example of embodiment of this invention is shown, (a) is sectional drawing, (b) is one part expanded sectional drawing. The joined state of a waterproof sheet is shown, (a) is sectional drawing of the joined state by an adhesive layer, (b) is sectional drawing of the joined state by an adhesive layer, and the sealing state by a sealing layer. A conventional example is shown, and (a) and (b) are partially enlarged sectional views.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waterproof sheet main body 2 Hot-melt-adhesion layer 3 Concavity and convexity 3a Concavity 4 Seal layer

Claims (5)

A carboxyl-modified polyethylene and a thermoplastic maleic acid-containing resin is a hot melt polymer, a chloroprene rubber is a reinforcing polymer, containing diphenylmethane diisocyanate crosslinking agent, along with being formed in a solvent-type, the hot melt polymer Dare the concentration of 20 40 mass% is, liquid adhesive, wherein the thermoplastic maleic acid-containing resin der Rukoto 20 to 40% by weight in the hot melt polymer. 2. The liquid adhesive according to claim 1, wherein the amount of the crosslinking agent is 5 to 30% by mass in a solid content ratio with respect to the hot melt polymer. It is a waterproof sheet joined by overlapping and heat-sealing joint parts, The liquid adhesive of Claim 1 or 2 is applied and dried on the surface of at least the said joint part of the said waterproof sheet main body. A waterproof sheet formed by forming a hot-melt adhesive layer. Overlapping the junction portions of the waterproof sheet according to claim 3, bonding waterproof sheets, which comprises heat sealing the joint portion of the waterproof sheet by heating and thereby melting the hot-melt adhesive layer Method. Overlapping the junction portions of the waterproof sheet formed by providing an adhesive layer on a surface of at least the junction of the tarpaulin main body, thereby joining the joining portions of the tarpaulin by the adhesive layer, superimposed in the waterproof sheet between the joint portion is coated with a liquid adhesive according subjected upper surface of the waterproof sheet of the upper end surface of the tarpaulin and lower in claim 1 or 2, sealed by crosslinking by heating the liquid adhesive A waterproof sheet joining method characterized by the above.

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