JP2007176997A - Waterstop sealing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waterstop sealing material which excels in the interfacial adhesion between the waterstop sealing material constituted of a foam structure having closed cells and a target structural member for water to be shut off, makes workability easy and enhances safety, hygienic environment, and reliability. <P>SOLUTION: The waterstop sealing material has a plurality of irregularities showing a geometric pattern on at least one surface of a foam structure having closed cells which uses a crosslinked rubber as the major raw material, and all projections forming the periphery of each of the above irregularities have the same height and are narrow, and have a nearly equal width, and when the projections come into contact with the interface of a target structural member for water to be shut off, the compressive force caused in the foam structure is exhibited to the full through the projections to seal the interface between the waterstop material and the target structural member for water to be shut off. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water-stop sealing material, and more particularly, to a water-stop sealing material based on a foam structure having closed cells made mainly of a crosslinked rubber.

The water-stop sealing material is used to fill gaps in various structures such as vehicles, buildings / civil engineering, and light electrical current, and prevents water from entering.
Conventionally, rubber foams and urethane foams are often used for this type of water-stopping sealant, and these are installed in a compressed state at the periphery where they want to stop water, and the repulsive stress closes the gap with the interface. , Preventing the ingress of water.
In particular, many automotive lamps, particularly rear lamps, are in a state of penetrating the trunk room, and there is a risk of water entering the vehicle body from the peripheral edge of the lamp, and water may enter the lamp and contact the lamp. May be short-circuited, and it is indispensable to use a water sealing material to prevent these.

A rubber foam or the like has excellent cushioning properties and is useful for applications such as cushion materials and pad materials. Comparing the closed cells and the open cells in the foam structure, the former is a structure in which the bubbles are partitioned by a partition in a three-dimensional lattice, whereas the latter is a partition between the series of partitioned bubbles. Is removed, and the latter is more easily mechanically deformed. However, open cells cannot be expected to have a water-stopping effect, whereas closed cells can be expected to have a water-stopping action because of the partition walls between the bubbles.
A foam structure with both closed and open cells can be expected to have both ease of filling a complex gap due to easy deformation based on open cells and water-stop properties based on closed cells. It is suitable as a fixed water sealing material that is used by filling a gap.

  However, when a closed cell foam structure or a semi-closed cell semi-open cell foam structure is used as a waterproof seal material, the repulsive stress as the foam structure is relaxed over time. Along with this, the contact surface pressure between the interface between the foam structure and the adherend (water blocking target structural member) decreases, and water leaks along this interface, effectively functioning as a water sealing material. There is a problem that it will not.

In order to solve such a problem, as shown in FIG. 3, a specific pressure-sensitive adhesive layer is provided on the surface of the foam structure having closed cells or both open cells and closed cells, so that the foam structure and the covered structure are covered. There has been proposed a method for bonding and sealing an interface of a bonded body (a structural member to be water-stopped) (see, for example, Patent Documents 1 to 3).
However, the method of providing the pressure-sensitive adhesive layer has a problem that it tends to hinder seal work such as alignment and repositioning.

In addition, the foam structure as a base is desirably a closed-cell foam structure from the viewpoint of water-stopping, but there is a problem that it is difficult to follow a complicated shape and a gap is likely to occur. Furthermore, when water is stopped with a closed cell foam structure having a simple shape, the repulsive force is increased, the structure floats with time, and water stoppage may be impaired.
For these reasons, open cell foam structures are also used. It is standard usage that this open cell foam structure is used by compressing a foam structure having a thickness of 6 mm or more to 70% or more. However, the open-cell foamed structure has high water absorption even when highly compressed, and the water that has been absorbed evaporates over time and enters the interior as water vapor, which may impair the water stoppage due to condensation. In particular, when used in a lamp for an automobile, water vapor is likely to be generated due to the heat generated by sunlight, which may cause fogging in the lamp and the like, and may cause the lamp contact to be short-circuited.
Furthermore, it is a standard usage method that the width of the water sealing material used is as thin as 10 to 20 mm. When the open-cell foam structure is processed in the above-described size, it is not stiff and easily deforms, so that the installation work is difficult. In particular, stamped parts are often used for automobile lamps that require high water-stopping performance, and installation work is difficult. Currently, water-stopping sealing materials that satisfy these requirements are provided. Absent.
Therefore, it consists of a foamed structure having closed cells, is a low-compression, high-performance water-proof sealing material, facilitates workability, and further improves fogging in the lamp due to water absorption, There is a strong demand for a water sealing material that enhances safety, hygiene environment and reliability.
JP 11-035924 A JP-A-11-236552 JP 11-236553 A

  In view of the above-mentioned problems of the prior art, the object of the present invention is excellent in interfacial adhesion between a water-stop sealing material made of a foam structure having closed cells and a structural member to be water-stopped, and facilitates workability. Another object of the present invention is to provide a waterproof seal material with improved safety, sanitary environment and reliability.

  As a result of intensive studies to achieve the above object, the present inventor gives a geometric pattern, for example, a polygonal uneven shape, to at least one surface of the foam structure as described above. As a result, the compressed force is concentrated on the convex and concave portions, and as a result, even with a small compressive force, it is possible to improve the adhesion between the convex portion and the structural member interface to be water-stopped. Furthermore, by reducing the size of the shape and increasing the number of convex portions to be closely adhered at the structural member interface, it is also found that the water stoppage can be improved, and by providing the concave portions, the curved surface of the structural member can be obtained. It has been found that the followability can be improved, and the followability to the curved surface of the structural member can be improved by changing the size of the recess. Further studies were conducted on these findings, and the present invention was completed.

That is, according to the first invention of the present invention, a water-stop seal having a plurality of uneven portions showing a geometric pattern on at least one surface of a foam structure having closed cells made mainly of a crosslinked rubber. Material,
The convex portions forming the periphery of each of the concave and convex portions have the same height and are narrow and substantially the same width, and when the convex portions contact the interface with the structural member to be water-stopped, The water stop seal is characterized in that the compressive force generated in the foamed structure is expressed to the maximum through the convex portion, so that the interface between the water stop seal material and the structural member to be water stop adheres. Material is provided.
According to the second invention of the present invention, in the first invention, the geometric pattern is at least one selected from linear, corrugated, polygonal, circle, ellipse, semicircle, fan or star shape. There is provided a water-stop sealing material characterized by comprising a seed unit shape.
Further, according to a third invention of the present invention, in the second invention, the unit shape is any polygon selected from a triangle, a quadrangle, a pentagon, a hexagon, and an octagon. A water sealing material is provided.

According to a fourth aspect of the present invention, there is provided the water-stop sealing material according to the second or third aspect, wherein the number of the unit shapes is 2 to 40 / cm ² .
According to a fifth aspect of the present invention, in the first aspect, the crosslinked rubber is at least one resin selected from chloroprene rubber, isoprene rubber, EPDM, butyl rubber, nitrile rubber, natural rubber or silicone rubber. A water-stop sealing material is provided.
Furthermore, according to a sixth aspect of the present invention, there is provided the water-stop sealing material according to the first aspect, wherein the foam structure is a sheet-like body.

According to a seventh invention of the present invention, in the first invention, there is provided a still water sealing material characterized in that the foamed structure contains a crystalline resin rich in moldability as a moldability improving material. Provided.
According to an eighth aspect of the present invention, in the seventh aspect, the crystalline resin is at least one selected from polyethylene, polypropylene, polyvinyl acetate, polyvinyl chloride, or polyvinylidene chloride. A water sealing material is provided.
Furthermore, according to the ninth invention of the present invention, in the first invention, the foam structure has a structure member that is a water stop target, although the surface having the uneven portion is different from the main raw material of the foam structure. A water-stop sealing material is provided, which is laminated with another resin film rich in adhesiveness.

According to a tenth aspect of the present invention, in the ninth aspect, the raw resin for the other resin film is at least one selected from polyethylene, polypropylene, polyvinyl acetate, polyvinyl chloride, or polyvinylidene chloride. A water-stop sealing material is provided.
According to an eleventh aspect of the present invention, in the first aspect, the foam structure is formed by coating or laminating a surface having a concavo-convex portion with a low polarity substance in order to improve water repellency. A water stop sealing material is provided.
Furthermore, according to a twelfth aspect of the present invention, in the eleventh aspect, the low polarity substance to be coated is a compound containing silicon or fluorine in the molecular structure, or a water repellent resin. A water sealing material is provided.
Still further, according to a thirteenth aspect of the present invention, in the eleventh aspect, the low-polarity material to be laminated is a thermoplastic resin film coated with a water repellent resin. Is provided.

According to the water-stop sealing material of the present invention, in the first invention, the interfacial adhesion between the water-stop sealing material made of a foam structure having closed cells and the structural member to be water-stopped is excellent, and workability is improved. It has the effect of facilitating and enhancing safety, hygiene environment and reliability, and can provide an excellent water-stop sealing material.
In the second to fourth inventions, since the geometric pattern is defined as having a specific unit shape, the water stopping performance and the followability to the curved surface of the structural member to be water stopped are further improved. There is an effect that can be done.
Furthermore, in the fifth invention, since the cross-linked rubber is specified, there is an effect that the adhesion with the structural member to be water-stopped is further improved and the water-stopping property is improved.
In the sixth aspect of the invention, since the shape of the foam structure is specified, there is an effect that workability and handleability are excellent.
Furthermore, in the seventh and eighth inventions, since the moldability improving material is defined, there is an effect that the water stopping performance and the followability to the curved surface of the structural member to be water stopping can be further improved. .
Furthermore, in the ninth to thirteenth and thirteenth inventions, since the surface state having the concavo-convex portion is specified, the effect of further improving the water tightness by improving the adhesion with the structural member that is a water stop target. is there.

Hereinafter, the water sealing material of the present invention will be described in detail.
The water-stop sealing material of the present invention is a water-stop sealing material having a plurality of concavo-convex portions showing a geometric pattern on at least one surface of a foam structure having closed cells made mainly of a crosslinked rubber. ,
The convex portions forming the periphery of each of the concave and convex portions have the same height and are narrow and substantially the same width, and when the convex portions contact the interface with the structural member to be water-stopped, When the compressive force generated in the foam structure is expressed to the maximum through the convex portion, the interface between the water-stop sealing material and the structural member to be water-stopped is in close contact. .
That is, the greatest feature of the present invention is that the compressive force (that is, the repulsive stress or the repulsive force) generated in the foam structure works only on the convex portion on the surface of the water sealing material (the concave portion does not adhere to the structural member). Therefore, the sealing property (or adhesion) between the convex portion and the structural member interface to be water-stopped is to be improved. In addition, by providing the concave portion, it is possible to improve the followability to the curved surface of the structural member to be water-stopped, and as a result, an excellent water-stop sealant can be provided.

The foam structure used in the present invention has closed cells whose main raw material is composed of a crosslinked rubber, and has partially closed cells, or partially has both open and closed cells. Any known material can be used, but those having a compression set (conforming to JIS K6767) of 20% or less, particularly 10% or less are excellent in shape recoverability and are preferred.
In addition, the foam structure can be used if the closed cell ratio is about 5% or more, but a particularly preferable range is 30% to 100%.

  The foamed structure of the crosslinked rubber according to the present invention can be produced by a known method. For example, uncrosslinked rubber, a vulcanizing agent (crosslinking agent), a foaming agent, a filler, etc. After kneading with a kneader such as a pressure kneader, it is formed into a sheet or rod shape while being continuously kneaded with a calendar, an extruder, a conveyor belt carriage, etc., and heated to vulcanize ( Crosslinking), foaming, and if necessary, a method of cutting this crosslinked (vulcanizing agent, organic peroxide or electron beam) foam into a predetermined shape, uncrosslinked rubber, crosslinking agent (vulcanizing agent, organic par Oxide or electron beam), foaming agent, filler, etc. are kneaded with mixin gall, etc., and this kneaded composition is batch-type cross-linked (vulcanizing agent, organic peroxide or electron beam), foaming and It is possible to use a molding method etc. Kill. That is, the method of a well-known crosslinked rubber foaming molding can be taken.

  Further, as a method for crosslinking the uncrosslinked rubber, either a method of heating using a crosslinking agent or a method of irradiation with light, γ-rays or electron beams may be employed. As the cross-linking agent, conventionally known organic peroxides, sulfur and sulfur compounds, electron beam irradiation, and the like that are usually used for rubber cross-linking can be used.

  The crosslinked rubber according to the present invention is not particularly limited. For example, chloroprene rubber (CR), isoprene rubber (IR), ethylene-propylene rubber (EPM or EPDM), butyl rubber (IIR), nitrile rubber (nitrile-butadiene rubber) ) (NBR), natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), urethane rubber, fluorine rubber, acrylic rubber, or silicone rubber, etc. Organic peroxide or electron beam). Among them, a cross-linking (vulcanizing agent, organic peroxide) of at least one resin selected from chloroprene rubber, isoprene rubber, EPDM, butyl rubber, nitrile rubber, natural rubber or silicone rubber. Oxide or electron beam) is good for cushioning and resistance. The preferred is excellent, such as the sex. Nitrile-butadiene rubber (NBR) is also referred to as nitrile rubber or acrylonitrile-butadiene copolymer rubber, and styrene-butadiene rubber (SBR) is also referred to as styrene rubber, which is a copolymer rubber of butadiene and styrene. Further, the ethylene-propylene rubber is an ethylene / propylene copolymer rubber (EPM or EPR), and a terpolymer obtained by adding a non-conjugated diene as a third component to the ethylene / propylene system. -Propylene-diene terpolymers (EPDM) are also included.

Moreover, in this invention, crystalline resin can also be mix | blended with a foamed structure as a compounding agent (material) for improving a moldability.
The crystalline resin is preferably at least one resin selected from polyethylene, polypropylene, polyvinyl acetate, polyvinyl chloride, or polyvinylidene chloride. These may be copolymers such as a copolymer of ethylene and vinyl acetate or a copolymer of ethylene and vinyl chloride. Moreover, it is preferable that it is resin excellent in moldability. By blending a compounding agent (material) for improving moldability, that is, a moldability improving material, in particular, the adhesion with a structural member to be water-stopped can be improved, and the water-stop performance can be improved. .

In the present invention, when preparing a foam structure, an appropriate compounding agent can be added for the purpose of adjusting viscosity, bridgeability, and foam physical properties such as strength. Examples include aldehyde accelerators, aldehyde amines, guanidines and thiazoles, sulfenamides and turums, dithiocarbamic acids, xanthogenic acids, thioureas and other vulcanization accelerators and vulcanization accelerators. It is done.
In addition, organic acids such as phthalic anhydride, benzoic acid and salicylic acid, vulcanization retarders such as amines such as N-nitroso-diphenylamine and N-nitroso-phenyl-β-naphthylamine, and poly (meth) acrylic acid alkyl esters Examples thereof include acrylic polymers and polyvinyl chloride.
In addition, paraffins and waxes such as chlorinated paraffin, drying oils such as linseed oil and animal and vegetable oils, petroleum oils and various low-volume polymers, phthalates and phosphates, stearic acid and its Softeners such as esters, alkyl sulfonates and tackifiers, talc and calcium carbonate, bentonite and carbon black, fumed silica and aluminum silicate, fillers such as acetylene black and aluminum powder, plasticizers and aging Examples thereof include an inhibitor, an antioxidant and a pigment, a colorant, an antifungal agent, and a foaming aid.

Moreover, the foaming method of the foam structure used in the present invention includes known methods including the method described in the plastic foam handbook, and any method may be used.
Furthermore, the thickness of the foamed structure is not particularly limited, but is generally in the range of 1 to 20 mm, and preferably in the range of 3 to 5 mm, for use in a waterproof seal.
Furthermore, the foam structure is preferably a sheet-like body from the viewpoints of workability and handleability.

In the present invention, at least one surface of the foam structure has a feature of having a plurality of uneven portions showing a geometric pattern, and the shape of the uneven portion shows a geometric pattern. The geometric pattern is composed of at least one unit shape selected from linear, corrugated, polygonal, circle, ellipse, semicircle, fan shape or star shape as shown in FIG. It is. Preferably, it is a polygon, and for example, a triangular shape, a quadrangular shape, a hexagonal shape, and an octagonal shape may be formed continuously.
The size (length and width, diameter) of the shape (unit shape) of one pattern is in the range of 1 to 10 mm, preferably 1.5 to 3 mm. The number of unit forms are 2 to 40 / cm ^2, preferably 8-20 / cm ^2.
Furthermore, the depth of the concave and convex portions is in the range of 0.3 to 2 mm, preferably 0.5 to 1.5 mm. On the other hand, the wall thickness of a convex part is the range of 0.2-3 mm, Preferably it is 0.5-1.5 mm.

Further, in the present invention, for example, by reducing the size of the polygonal uneven portion unit shape, it is possible to provide several uneven portions, and to follow the structural member curved surface to be water stopping performance and water stopping target. Can be improved. In addition, by changing the size of the concavo-convex portion unit shape, it is possible to improve the followability to the curved surface of the structural member that is a water stop target.
Furthermore, the foam structure can be water-stopped at a low compression rate of 50% or less by forming the irregularities, and the thickness of the material used should be thinner than the thickness of the conventional open-cell foam structure. Is also possible. Furthermore, it becomes possible to reduce the compressive stress of a foam structure by providing an uneven part. As a means for reducing the compressive stress, it is effective to remove the surface layer on the opposite side of the uneven surface of the foam structure.

  As an embodiment of the present invention, the water-stop sealing material of the present invention is provided with a concavo-convex process on the foam structure itself having closed cells on at least one surface of the foam structure having closed cells mainly composed of a crosslinked rubber. By giving, you may have a some uneven | corrugated | grooved part which shows a geometric pattern.

  Moreover, as another aspect, in order to further improve the water-stopping property, it is necessary to improve the adhesion with the structural member interface that is a water-stopping target. Specifically, the foamed structure having closed cells is foamed. The main raw material is polyethylene, polypropylene, vinyl acetate resin (polyvinyl acetate), vinyl chloride resin (polyvinyl chloride), vinylidene chloride resin (polyvinylidene chloride), etc., which are other thermoplastic resins different from the main raw material of the structure. The film can be laminated. By laminating, the smoothness of the surface can be improved, and as a result, flexibility and adhesion can be improved. In that case, the uneven | corrugated process for having the some uneven | corrugated | grooved part which shows a geometric pattern is given to the film surface of the foaming structure which has the closed cell which laminated the film.

Furthermore, as another aspect, by reducing the polarity of the surface of the water sealing material, the water stopping performance can be improved. For example, by providing a thin film of low polarity molecules containing silicon or fluorine in the molecular structure. , Water stoppage can be improved. Specifically, geometrical processing is applied to the foam structure with closed cells coated with water-repellent resin and the foam structure with closed cells laminated with a film coated with water-repellent resin to create a geometrical structure. It can have a plurality of concavo-convex portions showing a typical pattern.
In this way, a high-performance water sealing material can be obtained.

In the present invention, the surface of the foam structure is subjected to uneven processing in order to have a plurality of uneven portions showing a geometric pattern on at least one surface of the foam structure having closed cells made mainly of a crosslinked rubber. The method is not particularly limited, and a known method can be adopted.For example, after a crosslinked rubber or the like is kneaded with a kneader, it is molded into a sheet shape while kneading continuously with a calendar, an extruder or the like. Then, after heating and foaming, the surface of the foam structure is softened by heating to a degree of softening, for example, 80 ° C. A cooling roll (with an embossed mold) is pressure-bonded to give a geometric pattern to the surface of the foam structure, and then cooled to give the surface of the foam structure an uneven surface. In addition, by pressing an embossing roll (engraving roll) having a plurality of uneven portions showing a geometric pattern on a foam structure sheet having closed cells, and heating, that is, by embossing, the surface of the foam structure An uneven geometric pattern can be imparted.
In the case of a foamed structure having closed cells laminated with a film, first, for example, a foamed structure having closed cells is coated with a film of a thermoplastic resin or a water-repellent resin. After laminating with an adhesive, in the same manner as described above, a cooling roll or embossing roll having a plurality of uneven portions showing a geometric pattern is pressure-bonded to give an uneven geometric pattern on the surface of the foam structure. be able to.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited to these Examples.

[Example 1]
A foamed structure having closed cells mainly composed of a crosslinked product (EPDM vulcanized rubber) of EPDM (“EPT3012” manufactured by Mitsui Chemicals, Inc.) having a density of 0.03 to 0.04 g / ml and a thickness of 4 mm. The sheet A is embossed with a cooling roll on which an embossing mold is formed, and on the surface thereof, a rectangular continuous 3 mm pitch pattern having the same size on one side, a recess depth of 0.8 to 1 mm, and a protrusion wall thickness A water sealing material sheet having a concavo-convex pattern of 0.8 to 1 mm was obtained.
The foam structure sheet A is composed of 100 parts by weight of EPDM (“EPT3012” manufactured by Mitsui Chemicals), 15 parts by weight of azodicarbonamide (“SO-L” manufactured by Otsuka Chemical Co., Ltd.) as a foaming agent, and foaming aid. 1 part by weight of zinc stearate and 0.5 part by weight of dicumyl peroxide as peroxide were kneaded with a roll (140 ° C. × 5 minutes) and pressed (140 ° C. × 100 kg / cm ² × 5 minutes). A raw material sheet of 150 × 150 × 3 mm was produced, and this raw material sheet was put into an oven at 230 ° C. for 5 minutes and foamed to obtain. The foamed structure having closed cells obtained by this foaming had an expansion ratio of 30.5 times, a thickness of 9.8 mm, and a closed cell ratio of 85%. The closed cell ratio was measured by the 1-1 / 2-1 atm method using an air comparison type hydrometer 1000 type manufactured by Tokyo Science.

[Example 2]
Embossed foam sheet B with closed cells made mainly from a cross-linked product of chloroprene rubber (“Showrene 571” manufactured by Showa Denko KK) having a density of 0.03 to 0.04 g / ml and a thickness of 4 mm Embossing is performed on the cooling roll on which the mold is formed, and on the surface thereof, a rectangular continuous 3 mm pitch pattern having the same size on one surface, a recess depth of 0.8 to 1 mm, and a convex wall thickness of 0.8 to 1 mm A water sealing material sheet having an uneven pattern was obtained.
The foam structure sheet B is composed of 100 parts by weight of chloroprene rubber (“Showrene 571” manufactured by Showa Denko KK), 15 parts by weight of azodicarbonamide (“SO-L” manufactured by Otsuka Chemical Co., Ltd.) as a foaming agent, 1 part by weight of zinc stearate as an auxiliary agent and 0.5 part by weight of dicumyl peroxide as a peroxide are kneaded with a roll (140 ° C. × 5 minutes) and pressed (140 ° C. × 100 kg / cm ² × 5 minutes) Then, a raw material sheet of 150 × 150 × 3 mm was prepared, and this raw material sheet was put into an oven at 230 ° C. for 5 minutes and foamed to obtain. The foamed structure having closed cells obtained by this foaming had an expansion ratio of 30.5 times, a thickness of 9.8 mm, and a closed cell ratio of 85%.

[Example 3]
The surface of the foamed structure sheet A used in Example 1 was coated with silicon used for general release paper and a thin film with a thickness of 1 μm. On the surface, a water stop sealing material sheet having a rectangular continuous 3 mm pitch pattern having the same size on the entire surface, a concave and convex pattern with a concave portion depth of 0.8 to 1 mm, and a convex portion wall thickness of 0.8 to 1 mm was obtained. .

[Example 4]
The foam structure sheet A used in Example 1 was laminated with a polyethylene film (“KF1150” manufactured by Sekisui Film Co., Ltd., thickness 50 μm), and the embossing was performed with a cooling roll formed with an embossing mold. And the still water sealing material sheet | seat which has the concavo-convex pattern of the square continuous 3mm pitch pattern of the same size on the surface, the recessed part depth 0.8-1mm, and the convex part wall thickness 0.8-1mm on the surface was obtained.

[Example 5]
On the surface of the foam structure sheet A used in Example 1 laminated with a polyethylene film (“KF1150” manufactured by Sekisui Film Co., Ltd., thickness 50 μm), silicon used for general release paper has a thickness of 1 μm. The film was coated with a thin film, and then embossed with a cooling roll formed with an embossing mold. On the surface, a rectangular continuous 3 mm pitch pattern with the same size on the entire surface, recess depth of 0.8 to 1 mm, convex A water sealing material sheet having an uneven pattern with a partial wall thickness of 0.8 to 1 mm was obtained.

[Example 6]
The surface of the foamed structure sheet B used in Example 2 was coated with silicon used for general release paper and applied with a thin film having a thickness of 1 μm. On the surface, a water stop sealing material sheet having a rectangular continuous 3 mm pitch pattern having the same size on the entire surface, a concave and convex pattern with a concave portion depth of 0.8 to 1 mm, and a convex portion wall thickness of 0.8 to 1 mm was obtained. .

[Comparative Example 1]
The foam structure sheet A according to Example 1 was used as a water-stop sealing material.

[Comparative Examples 2 and 3]
In Comparative Example 2, a foamed structure sheet C having open cells having a density of 0.058 to 0.067 g / ml and a thickness of 8 mm and mainly made of polyurethane (“H6” manufactured by Nippon Kijo Co., Ltd.) Used as a water sealing material.
In Comparative Example 3, the surface of the foam structure sheet C of Comparative Example 2 was coated with silicon used for general release paper as a thin film having a thickness of 2 μm, and used as a water-stop sealing material.
The foam structure sheet C had an expansion ratio of 16.5 times, a thickness of 7.8 mm, and an open cell ratio of 98%. The open cell ratio was measured by the 1 1/2 to 1 atm method using an air comparison type hydrometer 1000 model manufactured by Tokyo Science.

(Evaluation)
About the water stop sealing material of the Example / comparative example obtained above, the characteristics of the following items were evaluated.
(1) Thickness (mm) of foam structure sheet: Measured according to JIS K6767.
(2) Density (g / ml) of the foam structure sheet: Measured according to JIS K7222.
(3) Compression rate (%) of the foam structure sheet: The gap when sandwiched and fixed between acrylic plates for waterstop evaluation is measured with calipers, and the numerical value is taken as the thickness (A) when compressed. The compression rate is calculated as follows.
Compression rate (%) = (Thickness before compression−Compression thickness (A)) / Thickness before compression × 100
(4) Compressive stress (kPa) of foam structure sheet: Measured according to JIS K6767.
(5) Water tightness of water sealing material: The evaluation method is as follows.
(I) A watertightness evaluation test sample is cut out to the size shown in FIG.
(Ii) This test sample is fixed to two 150 mm square and 10 mm thick transparent acrylic plates with a double-sided tape and sandwiched so that the bottoms are parallel as shown in FIG.
(Iii) The thickness is adjusted at a predetermined compression ratio with respect to the thickness of the test sample. Specifically, by adjusting the four screws of the transparent acrylic plate, the uniform four-way gaps are made equal.
(Iv) After adjusting the gap, as shown in FIG. 5-3, water is poured to a height of 100 mm (starting point).
(V) The water leakage from around the test sample is visually observed and evaluated as a water stop time (h). The end point of the water stop time was defined as the point at which leakage was confirmed even with one drop.

  The evaluation results are shown in Table 1.

According to the evaluation results in Table 1, it is clear from the comparison between Example 1 and Comparative Example 1 that the watertightness evaluation of the water-stop sealing material having a plurality of uneven portions showing a geometric pattern is good. It is.
In addition, when a film is laminated on the surface of the foam structure or a silicon thin film that is a low-polarity substance is applied to improve water repellency, the water-stopping property (watertightness) is improved. It can also be seen that when the surface treatment is applied, the water stoppage (water tightness) is further improved.

  The water-stop sealing material of the present invention is excellent in interfacial adhesion between a water-stop sealing material composed of a foam structure having closed cells and a structural member to be water-stopped, facilitates workability, and is safe and sanitary and environmentally friendly. Therefore, it can be suitably used as a high-performance waterproof seal material for filling gaps in various structures for various applications such as vehicles, construction / civil engineering, and weak electricity. Can do.

It is a schematic diagram showing an example of the water stop sealing material of this invention. It is sectional drawing of an example of the water stop sealing material of this invention. It is sectional drawing of an example of the conventional water stop sealing material. It is a figure which shows the geometric pattern of the uneven | corrugated | grooved part which concerns on the water-stop sealing material of this invention. It is a figure explaining the water-tightness evaluation test which concerns on the water stop sealing material of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concavity and convexity 2 Foam structure having closed cells 3 Adhesive layer

Claims (13)

A water-stop sealing material having a plurality of concavo-convex portions showing a geometric pattern on at least one surface of a foam structure having closed cells mainly made of a crosslinked rubber,
The convex portions forming the periphery of each of the concave and convex portions have the same height and are narrow and substantially the same width, and when the convex portions contact the interface with the structural member to be water-stopped, The water stop seal is characterized in that the compressive force generated in the foamed structure is expressed to the maximum through the convex portion, so that the interface between the water stop seal material and the structural member to be water stop adheres. Wood.   The said geometric pattern is comprised from at least 1 sort (s) of unit shape chosen from linear, a waveform, a polygon, a circle | round | yen, an ellipse, a semicircle, a fan shape, or a star shape. Water sealing material.   The water-stop sealing material according to claim 2, wherein the unit shape is any polygon selected from a triangle, a quadrangle, a pentagon, a hexagon, and an octagon. The number of the unit shape, water stopping sealing material according to claim 2 or 3, characterized in that a 2 to 40 / cm ^2.   The water-stop sealing material according to claim 1, wherein the crosslinked rubber is at least one resin selected from chloroprene rubber, isoprene rubber, EPDM, butyl rubber, nitrile rubber, natural rubber, or silicone rubber.   The water-stop sealing material according to claim 1, wherein the foam structure is a sheet-like body.   The waterproof structure sealing material according to claim 1, wherein the foamed structure contains a crystalline resin rich in moldability as a moldability improving material.   The water-stop sealing material according to claim 7, wherein the crystalline resin is at least one selected from polyethylene, polypropylene, polyvinyl acetate, polyvinyl chloride, or polyvinylidene chloride.   The foam structure is characterized by being laminated with another resin film whose surface having an uneven portion is different from the main raw material of the foam structure but has high adhesion to a structural member to be water-stopped. The water-stop sealing material according to claim 1.   10. The water-stop sealing material according to claim 9, wherein the raw material resin of the other resin film is at least one selected from polyethylene, polypropylene, polyvinyl acetate, polyvinyl chloride, or polyvinylidene chloride.   The water-stop sealing material according to claim 1, wherein the foamed structure is coated or laminated with a low-polar substance in order to improve the water repellency on the surface having the uneven portion.   The waterproof sealant according to claim 11, wherein the low-polarity material to be coated is a compound containing silicon or fluorine in a molecular structure, or a water-repellent resin.   The waterproof sealant according to claim 11, wherein the low-polarity material to be laminated is a thermoplastic resin film coated with a water-repellent resin.

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