JP2017043651A - Isolated cell expanded material cutoff sheet with adhesion layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an isolated cell expanded material cutoff sheet with an adhesion layer maintaining good moldability, moderate compression flexibility and reworkability, capable of enduring cleaning by high water pressure, for example 5 MPa or more and having excellent adhesiveness and cutoff property.SOLUTION: There is provided an isolated cell expanded material cutoff sheet with an adhesion layer by adhering an adhesion layer which contains a rubber component (A) having total content of a butyl rubber (a1) and an ethylene-propylene-diene rubber (a2) of 80 mass% or more and a petroleum resin-based tackifier (B) and has thickness of 0.01 to 2.0 mm and a rubber resin isolated cell expanded material sheet by foaming a foaming agent at state where an expandable resin sheet which contains an acrylonitrile-butadiene rubber containing an acrylonitrile component of 33.5 to 50 mass% and the foaming agent is crosslinked by irradiation with ionization radiation, where mass ratio [(a2)/(a1)] is 0/100 to 93/7 and content of the petroleum resin-based tackifier (B) to 100 pts.mass of the rubber component (A) is 0.5 to 20 pts.mass.SELECTED DRAWING: None

Description

  The present invention relates to a closed cell foam water-stop sheet with an adhesive layer used as a water-stop seal material.

At present, in various fields such as civil engineering, architecture, electrical / electronics, and vehicles, a waterproof seal material made of foam is widely used to fill the gaps of various structures and prevent water from entering. Such a water-stop sealing material is arranged on the adherend portion in a compressed state, and is configured to closely contact the interface of the adherend portion without a gap due to repulsive stress that attempts to recover the shape from the compressed state. . Therefore, if the compressive flexibility of the water sealing material is low, the repelling stress of the water sealing material becomes too strong and the adherent part is deformed. The problem arises that the performance becomes insufficient.
Therefore, it is conceivable to use an open-cell foam excellent in compression flexibility as a water-stop sealing material. However, since the open-cell foam communicates with each other, water easily permeates through the foam, so that sufficient water-stopping can be achieved. There was a problem that it was not possible to obtain water.

As a water-stop sealing material for solving this problem, for example, Patent Document 1 discloses a water-stop sealing material using a rubber-based resin closed cell foam sheet having closed cells using acrylonitrile-butadiene rubber containing a specific amount of an acrylonitrile component. 2.
In recent years, as will be described later, while maintaining excellent moldability, moderate compression flexibility and reworkability so as to be able to withstand even washing using a high-pressure washing machine, further excellent adhesion and water stoppage are provided. It has been demanded.

  For example, Patent Document 3 discloses that a vehicle is washed by a user using a high-pressure washing machine or the like. In recent years, high-pressure washing machines that allow ordinary users to wash building joinery and vehicles with a high water pressure of 5 MPa or more are commercially available. When a high-pressure washer is used, the water-stop sealing material that exists in a compressed state between the first member and the second member, which are the adherend parts, is a range including a direction perpendicular to the compression direction, specifically There is a possibility that the water flow of high water pressure discharged from the high-pressure washing machine in a range of 20 ° to 160 ° with respect to the compression direction directly hits, the water stop sealing material is deformed by the high water pressure, and water enters. .

JP 2009-242615 A International Publication No. 2011/039877 JP 2011-124143 A

Since the waterproofing sealing material as disclosed in Patent Documents 1 and 2 is used in various products, excellent moldability is required. Furthermore, the water-stop sealing material needs to adhere to the adherent part, while the attachment position can be finely corrected when the water-stop seal material is attached to the product. It is necessary to be excellent in the property and re-stickability (hereinafter also referred to as “reworkability”).
Furthermore, in accordance with the recent needs for high-pressure cleaning, water-stop seal materials are required to have appropriate compression flexibility with good assemblability, and in a range including a direction perpendicular to the compression direction, specifically compression. Water-stopping and adhesion that can withstand a high water pressure that strikes directly in the range of 20 ° to 160 ° with respect to the direction are also required.

  The present invention has been made in view of the above-described conventional problems, and can withstand washing at a high water pressure of, for example, 5 MPa or more while maintaining excellent moldability, appropriate compression flexibility, and reworkability. Provided is a closed cell foam water-stop sheet with a close-contact layer having adhesiveness and water-stop.

[1] A rubber component (A) having a total content of butyl rubber (a1) and ethylene-propylene-diene rubber (a2) of 80% by mass or more and a petroleum resin-based tackifier (B) having a thickness of 0. A foaming agent in a state where an adhesive layer of 01 to 2.0 mm, an acrylonitrile-butadiene rubber containing 33.5 to 50% by mass of an acrylonitrile component and a foaming resin sheet containing a foaming agent are crosslinked by irradiation with ionizing radiation Is a closed-cell foam water-stop sheet with an adhesive layer in which a rubber-based resin closed-cell foam sheet obtained by foaming is adhered, and the mass ratio of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) [ (A2) / (a1)] is 0/100 to 93/7, and the content of the petroleum resin-based tackifier (B) with respect to 100 parts by mass of the rubber component (A) 0.5 to 20 parts by weight, the adhesion layer with closed cell foam waterproofing sheet.
[2] The acrylonitrile-butadiene, wherein the rubber-based resin closed-cell foam sheet has rubber elasticity at 20 ° C. and 1.01 × 10 ⁻¹ MPa and contains 33.5 to 50% by mass of an acrylonitrile component. With adhesion layer as described in said [1] containing 100 mass parts of rubber | gum and 0.5-10 mass parts of liquid acrylonitrile-butadiene rubber which has fluidity | liquidity under 20 degreeC and 1.01 * 10 < ^-1 > MPa. Closed cell foam waterproofing sheet.
[3] The closed cell foam water-stop sheet with an adhesion layer according to [1] or [2], wherein the apparent density of the closed cell foam sheet is 15 to 700 kg / m ³ .
[4] The closed cell foam water-stop sheet with an adhesive layer according to any one of [1] to [3], wherein the Mooney viscosity ML (1 + 8) at 125 ° C. of the butyl rubber (a1) is 20 to 60. .
[5] The closed cell foam waterproofing sheet with an adhesion layer according to any one of [1] to [4], wherein the closed cell foam sheet has a thickness of 0.05 to 15 mm.
[6] The closed-cell foam waterproofing sheet with an adhesion layer according to any one of [1] to [5], wherein the adhesion layer has a thickness of 0.03 to 1.0 mm.
[7] The closed cell foam water-stop sheet with an adhesive layer according to any one of [1] to [6], wherein the mass ratio [(a2) / (a1)] is 1/99 to 90/10. .

  The present invention maintains an excellent moldability, moderate compression flexibility and reworkability, and can withstand washing with a high water pressure of, for example, 5 MPa or more, and has closed cell foam with an adhesion layer having excellent adhesion and water-stopping properties. A body water-stop sheet can be provided.

  The present invention includes a rubber component (A) having a total content of butyl rubber (a1) and ethylene-propylene-diene rubber (a2) of 80% by mass or more and a petroleum resin-based tackifier (B), and has a thickness of 0. Foaming in a state where an adhesive layer having a thickness of 0.01 to 2.0 mm, an acrylonitrile-butadiene rubber containing 33.5 to 50% by mass of an acrylonitrile component, and a foaming resin sheet containing a foaming agent are crosslinked by irradiation with ionizing radiation. A closed cell foam water-stop sheet with an adhesive layer in which a rubber-based resin closed cell foam sheet obtained by foaming an agent is adhered, and the mass ratio of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) [(A2) / (a1)] is 0/100 to 93/7, and the petroleum resin-based tackifier (B) is contained in 100 parts by mass of the rubber component (A). The amount is 0.5 to 20 parts by weight, the adhesion layer with closed cell foam waterproofing sheet (hereinafter, simply referred to as "water stop sheet".) Relates.

The rubber-based resin closed-cell foam sheet is 100 parts by mass of acrylonitrile-butadiene rubber having rubber elasticity at 20 ° C. and 1.01 × 10 ⁻¹ MPa and containing 33.5 to 50% by mass of an acrylonitrile component. And 0.5 to 10 parts by mass of liquid acrylonitrile-butadiene rubber having fluidity at 20 ° C. and 1.01 × 10 ⁻¹ MPa.

[Adhesion layer]
The adhesion layer used in the present invention includes a rubber component (A) having a total content of butyl rubber (a1) and ethylene-propylene-diene rubber (a2) of 80% by mass or more and a petroleum resin-based tackifier (B). The thickness is 0.01 to 2.0 mm. In the present invention, since the rubber component (A) and the petroleum resin-based tackifier (B) are used in the adhesion layer, the reworkability and adhesion, and the water stopping ability that can sufficiently withstand the high water pressure by the high pressure washer. The water stop sheet | seat which has can be provided.

<Rubber component (A)>
The rubber component (A) has a total content of butyl rubber (a1) and ethylene-propylene-diene rubber (a2) of 80% by mass or more. If the total content of the butyl rubber (a1) and the ethylene-propylene-diene rubber (a2) is less than 80% by mass, the water-stopping property may be lowered.
The total content of the butyl rubber (a1) and the ethylene-propylene-diene rubber (a2) contained in the rubber component (A) is 80% by mass or more, preferably 85% from the viewpoint of improving the reworkability and water stoppage. % Or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and still more preferably 100% by mass.

The rubber component (A) has a mass ratio [(a2) / (a1)] of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) of 0/100 to 93/7. If the mass ratio [(a2) / (a1)] is within the above range, the moldability, reworkability and water stoppage are improved.
In the present invention, the mass ratio [(a2) / (a1)] is preferably 1/99 to 90/10, more preferably 1/99 to 85/15, from the viewpoints of moldability, reworkability, and water-stopping property. Preferably from 1/99 to 80/20, more preferably from 1/99 to 75/25, still more preferably from 2/98 to 70/30, still more preferably from 3/97 to 50/50, still more preferably. 5/95 to 30/70.

(Butyl rubber (a1))
In addition to butyl rubber (IIR), halogenated butyl rubber can also be used as the butyl rubber in the present invention. Examples of the halogenated butyl rubber include chlorinated butyl rubber and brominated butyl rubber. Among these, it is preferable to use butyl rubber (IIR) from the viewpoint of improving kneadability during extrusion and flexibility after sheet molding.
The Mooney viscosity ML (1 + 8) at 125 ° C. of butyl rubber is preferably 20 to 60, more preferably 25 to 55, and still more preferably 25 to 40. If the Mooney viscosity is within the above range, the cohesive force is improved, the strength of the molded body is improved, and the load applied to the kneading apparatus during kneading can be reduced, so that the moldability is improved.

(Ethylene-propylene-diene rubber (a2))
As the ethylene-propylene-diene rubber, a small amount of a third component is introduced into ethylene propylene rubber, which is a copolymer of ethylene and propylene, to give a double bond in the main chain. Examples of the third component include ethylidene norbornene, 1,4-hexadiene, and dicyclopentadiene.
The diene content in the ethylene-propylene-diene rubber (a2) is preferably 1 to 15% by mass, more preferably 2 to 12% by mass, from the viewpoint of preventing heat generation during extrusion kneading and improving mechanical properties such as elongation. %, More preferably 3 to 10% by mass.

The Mooney viscosity ML (1 + 4) at 125 ° C. of the ethylene-propylene-diene rubber (a2) is preferably 15 to 70, more preferably 15 to 60, still more preferably 20 to 50, and still more preferably 24 to 30. If the Mooney viscosity at 125 ° C. of the ethylene-propylene-diene rubber (a2) is equal to or higher than the lower limit value, the cohesive force is increased, so that the strength of the molded body is improved. Formability is improved because the load is reduced.
Examples of commercially available ethylene-propylene-diene rubbers include EP21, EP22 and EP33 (manufactured by JSR Corporation), Esprene 567 (manufactured by Sumitomo Chemical Co., Ltd.), EPT3045 (manufactured by Mitsui Petrochemical Industries, Ltd.) and the like. .

The rubber component (A) may contain rubber other than butyl rubber (a1) and ethylene-propylene-diene rubber (a2). Other rubbers are not particularly limited as long as they have rubber elasticity at room temperature (25 ° C.). For example, chloroprene rubber (CR), isoprene rubber (IR), natural rubber, styrene-butadiene copolymer Examples include polymerized rubber (SBR), butadiene rubber (BR), urethane rubber, fluororubber, acrylic rubber, and silicone rubber. These may be used alone or in combination of two or more.

<Petroleum resin tackifier (B)>
In the adhesion layer, the petroleum resin-based tackifier (B) is used for the purpose of improving the adhesion with the adherend surface of the water-stop sheet. In the present invention, the petroleum resin-based tackifier (B) refers to a tackifier obtained by cationic polymerization of a fraction containing unsaturated hydrocarbons obtained by thermal decomposition of petroleum naphtha or the like.
Conventionally, a tackifier has been blended into a rubber molded body, but a commonly used tackifier has a high level of reworkability, adhesion to the adherend surface, and waterstop. It was difficult to improve. Tackifiers obtained by cationic polymerization of fractions containing unsaturated hydrocarbons obtained by thermal decomposition of petroleum naphtha, etc. have good reworkability, high adhesion to the adherend surface, and excellent adhesion to water. A layer can be obtained.
When the petroleum resin-based tackifier (B) is used in the present invention, the reason why the adhesion with the adherend surface of the water-stop sheet is not clear, but the dispersibility of the petroleum resin-based tackifier in the rubber component is not clear. This is considered to be due to the goodness.

The petroleum resin tackifier (B) includes C5 petroleum resin tackifier, C9 petroleum resin tackifier, C5-C9 copolymer petroleum resin tackifier, coumarone resin tackifier, coumarone-indene series. Examples thereof include resin tackifiers, pure monomer resin tackifiers, dicyclopentadiene petroleum resin tackifiers, and tackifiers composed of these hydrides.
Among these, C5 petroleum resin tackifier, C9 petroleum resin tackifier, from the viewpoint of improving the adhesion with the adherend surface of the water-stop sheet and the compatibility with the rubber component (A), A C5-C9 copolymer petroleum resin tackifier is preferred, and a C5 petroleum resin tackifier is more preferred.

  The content of the petroleum resin-based tackifier (B) with respect to 100 parts by mass of the rubber component (A) maintains the waterproof property by improving the adhesion and maintains the appropriate flexibility, and the performance against water pressure. From a viewpoint of improving, it is 0.5-20 mass parts, Preferably it is 1.5-15 mass parts, More preferably, it is 3-12 mass parts, More preferably, it is 3.5-9 mass parts. If the content of the petroleum resin-based tackifier (B) with respect to 100 parts by mass of the rubber component (A) is less than the lower limit, the water stopping performance is lowered, and if it exceeds the upper limit, the extrusion moldability is lowered.

<Additives used in the adhesion layer>
The adhesion layer may contain an additive. Examples of the additive include a flame retardant, an antioxidant, a filler, a pigment, a colorant, an antifungal agent, a foaming aid, a lubricant, an inactivating agent, and a flame retardant aid.
Examples of the flame retardant include bromine-based flame retardants such as decabromodiphenyl ether and phosphorus-based flame retardants such as ammonium polyphosphate in addition to metal hydroxides such as aluminum hydroxide and magnesium hydroxide.
Examples of the antioxidant include a phenol-based antioxidant and a sulfur-based antioxidant.
Examples of the filler include talc, calcium carbonate, bentonite, carbon black, fumed silica, aluminum silicate, acetylene black, and aluminum powder. These additives may be used alone or in combination of two or more.

<Thickness of adhesion layer>
The thickness of the adhesion layer is 0.01 to 2.0 mm, preferably 0.03 to 1.0 mm, more preferably 0.05 to 0.3 mm. When the thickness is within the above range, the adhesion performance is exhibited and warpage is hardly generated, which is preferable. In addition, “warping” in the present specification means that the closed-cell foam water-stop sheet of the present invention is cut into a size of 500 mm × 500 mm and placed on a flat table, and a part of the cut closed-cell foam water-stop sheet is removed from the table. The state where it is separated by 15 mm or more and is floating.

<Method for producing adhesion layer>
Although there is no particular limitation on the method for producing the adhesion layer, after the rubber component (A), the petroleum resin-based tackifier (B), and the additive are melt-kneaded in an extruder, extrusion molding, calendar molding, inflation molding, Or it can obtain by performing the solution cast molding which melt | dissolves resin in a solution form and evaporates and extracts only resin. As the molding method, extrusion molding is preferred from the viewpoint of productivity and the like.

[Rubber resin closed cell foam sheet]
The rubber-based resin closed-cell foam sheet used in the present invention is a state in which an acrylonitrile-butadiene rubber containing 33.5 to 50% by mass of an acrylonitrile component and a foamable resin sheet containing a foaming agent are crosslinked by irradiation with ionizing radiation. The foaming agent is foamed.

The rubber-based resin closed-cell foam sheet used in the present invention has acrylonitrile-butadiene having rubber elasticity at 20 ° C. and 1.01 × 10 ⁻¹ MPa and containing 33.5 to 50% by mass of an acrylonitrile component. 100 parts by mass of rubber and 0.5 to 10 parts by mass of liquid acrylonitrile-butadiene rubber having fluidity at 20 ° C. and 1.01 × 10 ⁻¹ MPa.

The rubber-based resin needs to have rubber elasticity at room temperature. Specifically, the rubber-based resin needs to have rubber elasticity and not liquid at 20 ° C. and 1 atm (1.01 × 10 ⁻¹ MPa). As the rubber-based resin, acrylonitrile-butadiene rubber (NBR) is used because it has excellent moldability and compressibility, for example, excellent adhesion and water-stopping ability that can withstand washing by high water pressure of 5 MPa or more.

  The content of the acrylonitrile component in the acrylonitrile-butadiene rubber is 33.5 to 50% by mass, more preferably 35 to 50% by mass. When the content of the acrylonitrile component in the acrylonitrile-butadiene rubber is less than 33.5% by mass, a rubber-based resin closed cell foam sheet formed by foaming in a state where the foamable resin sheet is crosslinked is used as a waterproof sealant. In some cases, adhesion and water stoppage may be reduced. When the content of the acrylonitrile component in the acrylonitrile-butadiene rubber exceeds 50% by mass, it is difficult to obtain the acrylonitrile-butadiene rubber in which the content of the acrylonitrile component exceeds 50% by mass, and the flexibility at low temperature decreases. Water stoppage may be reduced.

In addition to acrylonitrile-butadiene rubber, the foamable resin sheet may contain a rubber-based resin that is liquid at room temperature (hereinafter referred to as “liquid rubber-based resin”). The liquid rubber is a rubber-based resin having fluidity at normal temperature, specifically, 20 ° C. and 1 atm (1.01 × 10 ⁻¹ MPa). It is because the kneading | loading load of the foamable resin composition mentioned later can be reduced by containing liquid rubber-type resin in the foamable resin composition containing an acrylonitrile-butadiene rubber and a foaming agent.

  Examples of liquid rubber resins include liquid acrylonitrile-butadiene rubber (liquid NBR), liquid hydrogenated acrylonitrile-butadiene rubber (liquid HNBR), liquid carboxylated acrylonitrile-butadiene rubber (liquid XNBR), and liquid acrylonitrile. -Liquid acrylonitrile rubbers such as butadiene-isoprene rubber (liquid NBIR), liquid acrylonitrile-isoprene rubber (liquid NIR), and liquid terpolymers of acrylonitrile, butadiene, and functional monomers having anti-aging functions; Liquid isoprene rubber (liquid IR) and the like, and from the point of obtaining a rubber-based resin closed-cell foamed sheet excellent in sealability, compression flexibility, durability and oil resistance, liquid acrylonitrile-based rubber is preferable, and liquid acrylonitrile- Tajiengomu (liquid NBR) is preferred. The content of the acrylonitrile component in the liquid acrylonitrile-butadiene rubber (liquid NBR) is not particularly limited. In addition, liquid rubber-type resin may be used independently and may use 2 or more types together.

  The content of the liquid acrylonitrile-butadiene rubber in the rubber-based resin closed cell foam sheet is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the acrylonitrile-butadiene rubber. Part, particularly preferably 2 to 4 parts by mass. When the content of the liquid acrylonitrile-butadiene rubber is within the above range, the load during kneading is reduced and the kneading can be easily performed, and the liquid rubber bleeds out from the rubber-based resin closed cell foam sheet. This is preferable because it is difficult to suppress a decrease in water stoppage.

  Furthermore, an additive may be contained in the rubber-based resin closed cell foam sheet. Examples of such additives include flame retardants, antioxidants, fillers, pigments, colorants, fungicides, foaming aids, flame retardant aids, and the like.

  The flame retardant is not particularly limited. For example, in addition to metal hydroxides such as aluminum hydroxide and magnesium hydroxide, brominated flame retardants such as decabromodiphenyl ether, phosphorus flame retardants such as ammonium polyphosphate, and the like. May be used alone or in combination of two or more. Examples of the flame retardant include a brominated flame retardant commercially available from Albemarle Japan Co., Ltd. under the trade name “SAYTEX8010”.

  It does not specifically limit as antioxidant, For example, a phenolic antioxidant, a sulfur type antioxidant, etc. are mentioned, You may use independently and may use 2 or more types together. Examples of the antioxidant include a phenolic antioxidant commercially available from BASF Japan Ltd. under the trade name “IRGANOX 1010”.

  Examples of the filler include, but are not limited to, talc, calcium carbonate, bentonite, carbon black, fumed silica, aluminum silicate, acetylene black, aluminum powder, and the like. You may use together.

<Method for producing rubber-based resin closed cell foam sheet>
Next, the manufacturing method of a rubber-type resin closed cell foam sheet is demonstrated. As a method for producing a rubber-based resin closed-cell foam sheet, for example, an acrylonitrile-butadiene rubber containing an acrylonitrile component and an expandable resin sheet containing a foaming agent are irradiated with ionizing radiation. Examples include a method of producing a rubber-based resin closed cell foam sheet by crosslinking a foamable resin sheet and then heating the crosslinked foamable resin sheet to foam a foaming agent.

As a method for producing a rubber-based resin closed cell foam sheet, acrylonitrile-butadiene rubber having rubber elasticity at 20 ° C. and 1.01 × 10 ⁻¹ MPa and containing 33.5 to 50% by mass of an acrylonitrile component is used. It consists of a foamable resin composition containing 100 parts by mass, 0.5 to 10 parts by mass of liquid acrylonitrile-butadiene rubber having fluidity at 20 ° C. and 1.01 × 10 ⁻¹ MPa, and a foaming agent. After the foamable resin sheet is irradiated with ionizing radiation to crosslink the foamable resin sheet, the crosslinked foamable resin sheet is heated to foam the foaming agent to produce a rubber-based resin closed cell foam sheet. It is preferable.

[Method for producing foamable resin sheet]
As the method for producing the foamable resin sheet, for example, the foamable resin composition is kneaded using a kneader such as a Banbury mixer or a pressure kneader, and then continuously by an extruder, a calendar, a conveyor belt casting, or the like. And a method of producing a foamable resin sheet by kneading.

[Crosslinking method of foamable resin sheet]
The method for crosslinking the foamable resin sheet is limited to crosslinking by ionizing radiation. This is because a foamed resin sheet that is uniformly cross-linked is obtained by cross-linking treatment with ionizing radiation, and rubber having a small diameter and uniform bubbles is obtained by foaming the uniformly cross-linked foamable resin sheet. This is because a resin-based closed cell foam sheet can be obtained. Such a rubber-based resin closed cell foam sheet having uniform bubbles with a small diameter has a smooth surface, a large contact area with the adhesion layer, adhesion of the adhesion layer to the adherend and adhesion layer Since the adhesiveness of the rubber-based resin closed-cell foam sheet is improved, it is possible to obtain a waterstop sheet having excellent adhesiveness and waterstop that can withstand washing with a high water pressure of, for example, 5 MPa or more.

  The irradiation amount of the ionizing radiation to the foamable resin sheet may be appropriately adjusted depending on the characteristics of the rubber-based resin and the use of the rubber-based resin closed cell foam sheet, but is preferably 0.5 to 10 Mrad, 0.7 to 5.0 Mrad is more preferable.

  The foaming agent contained in the foamable resin sheet is not particularly limited, and examples thereof include azodicarbonamide, benzenesulfonyl hydrazide, dinitrosopentamethylenetetramine, toluenesulfonyl hydrazide, 4,4-oxybis (benzenesulfonyl hydrazide), and the like. And azodicarbonamide is preferred. A foaming agent may be used independently and may use 2 or more types together.

  If the content of the foaming agent is small, a sufficiently foamed rubber-based resin closed cell foam sheet cannot be obtained, and a rubber-based resin closed cell foam sheet having a desired shape may not be obtained. On the other hand, if the content of the foaming agent is large, abnormal foaming or bubble breakage may occur, making it impossible to obtain a predetermined rubber-based resin closed cell foam sheet. As for content of a foaming agent, 1-30 mass parts is preferable with respect to 100 mass parts of acrylonitrile-butadiene rubbers.

[Foaming method of foamable resin sheet]
Examples of the method for foaming the foamable resin sheet include a batch system such as an oven and a continuous foaming system in which the foamable resin sheet is formed into a long sheet shape and continuously passed through a heating furnace.
Although the temperature at the time of foaming a foamable resin sheet is based also on the kind of foaming agent to be used, Preferably it is 200-300 degreeC, More preferably, it is 220-280 degreeC.

<Thickness of rubber-based resin closed cell foam sheet>
The thickness of the rubber-based resin closed cell foam sheet is appropriately selected depending on the intended use and is not particularly limited, but is preferably 0.05 to 15 mm, more preferably 0.1 to 10 mm, and still more preferably 1 to 8 mm. It is preferable for the thickness to be in the above-mentioned range since warpage is unlikely to occur.

<Appearance density of rubber-based resin closed cell foam sheet>
From the viewpoint of improving the flexibility of the rubber-based resin closed cell foam sheet, the apparent density of the rubber-based resin closed cell foam sheet is preferably 15 to 700 kg / m ³ , more preferably 17 to 600 kg / m ³ , and further Preferably it is 20-500 kg / m < ³ >. When the apparent density is within the above range, the repulsive force does not become too high, so that the workability is improved. Even when the apparent density of the rubber-based resin closed cell foam sheet is high, it can be used by lowering the compression rate.

<Closed cell ratio of rubber-based resin closed cell foam sheet>
The closed-cell ratio of the rubber-based resin closed-cell foam sheet used in the present invention is 70% or more, and some of the bubbles may contain open cells. The closed cell ratio of the closed cell foam sheet is preferably 70 to 100%, more preferably 80 to 100%, and still more preferably 83 to 100%, from the viewpoint of water blocking.
The rubber-based resin closed-cell foamed sheet used in the present invention does not need to be all closed cells, and some of the bubbles may contain open cells. The closed cell ratio of the rubber-based resin closed cell foam sheet is preferably 80 to 100%, more preferably 85 to 100%. If the bubble ratio of the rubber-based resin closed cell foam sheet is low, the bubbles of the rubber-based resin closed cell foam sheet communicate with each other and water can easily permeate. May decrease.

The closed cell ratio in the present invention refers to that measured in the following manner.
First, a test piece having a flat square shape with a side of 5 cm and a constant thickness is cut out from the closed cell foam sheet. Then, the thickness of the test piece is measured to calculate the apparent volume V ₁ of the test piece, and the weight W _{1 of the} test piece is measured.
Next, the volume V ₂ occupied by the bubbles is calculated based on the following formula. The density of the resin constituting the test piece is ρg / cm ³ .
Volume occupied by bubbles V ₂ = V ₁ −W ₁ / ρ
Subsequently, the test piece is submerged in distilled water at 23 ° C. to a depth of 100 mm from the water surface, and a pressure of 15 kPa is applied to the test piece over 3 minutes. Thereafter, the test piece is taken out from the distilled water, the moisture adhering to the surface of the test piece is removed, the weight W _{2 of the} test piece is measured, and the open cell rate F ₁ and the closed cell rate F ₂ are calculated based on the following formula. calculate.
Open cell ratio F ₁ (%) = 100 × (W ₂ −W ₁ ) / V ₂
Closed cell ratio F ₂ (%) = 100−F ₁

[Method for producing closed-cell foam water-stop sheet with adhesion layer]
Although there is no special restriction in the manufacturing method of the waterproof sheet of this invention, it can manufacture by laminating | stacking the rubber-type resin closed cell foam sheet manufactured by the said method, and the contact | adherence layer manufactured by the said method.
Specifically, each material of the adhesion layer described above is continuously supplied to a single-screw or twin-screw extruder, and after kneading at a temperature equal to or higher than the melting point of the resin in the kneading section, the resin pressure of the molten resin is reduced. 80-250 kg / cm < ² >, pinch pressure is 0.1-10.0 kg / cm < ² >, pinch roll temperature is 10-50 degreeC, and it can obtain by the method (extrusion molding) bonded together to a closed cell foam sheet.

[25% compressive stress of closed cell foam waterproofing sheet with adhesion layer]
The 25% compressive stress of the waterproof sheet of the present invention is 2 to 300 kPa, preferably 5 to 300 kPa, and more preferably 8 to 100 kPa. When the 25% compressive stress of the waterstop sheet is within the above range, workability is improved and assembly is improved. In addition, 25% compressive stress can be measured by the method as described in an Example.

Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
The materials used in the following examples and comparative examples are as follows.
・ Butyl rubber (IIR)
Butyl rubber (1): “BUTYL065” manufactured by JSR Corporation
Mooney viscosity ML (1 + 8) 125 ° C. = 32
Butyl rubber (2): “BUTYL268” manufactured by JSR Corporation
Mooney viscosity ML (1 + 8) 125 ° C. = 51
・ Ethylene-propylene-diene rubber (EPDM)
Ethylene-propylene-diene rubber (1): “EP21” manufactured by JSR Corporation
Mooney viscosity ML (1 + 4) 125 ° C. = 26
Ethylene-propylene-diene rubber (2): “EP25” manufactured by JSR Corporation
Mooney viscosity ML (1 + 4) 125 ° C. = 63
・ Acrylonitrile-butadiene rubber (NBR)
Acrylonitrile-butadiene rubber (1): “Nipol 1041” manufactured by Nippon Zeon Co., Ltd. Content of acrylonitrile component: 40.5 mass%
Acrylonitrile-butadiene rubber (2): “Nipol 1042” manufactured by Nippon Zeon Co., Ltd. Content of acrylonitrile component: 33.5% by mass
・ Liquid acrylonitrile ・ butadiene (liquid NBR)
“Nipol 1312” manufactured by Nippon Zeon Co., Ltd.

・ Petroleum resin tackifier Petroleum resin tackifier (1): “QuintoneR-100” manufactured by Nippon Zeon Co., Ltd.
Petroleum resin-based tackifier (2): “QuintoneA-100” manufactured by Nippon Zeon Co., Ltd.
Petroleum resin-based tackifier (3): “Quintone G-115” manufactured by Zeon Corporation
・ Rosindiol-based tackifier “Pine Crystal D-6011” manufactured by Arakawa Chemical Industries, Ltd.
・ Terpene phenol tackifier Yasuhara Chemical Co., Ltd. “YS Polystar T80”

・ ADCA (1) (azodicarbonamide)
"Unihome SO-G3IST" manufactured by Otsuka Chemical Co., Ltd.
・ ADCA (2) (azodicarbonamide)
"SO-L" manufactured by Otsuka Chemical Co., Ltd.

・ Phenolic antioxidant (1)
"ADEKA STAB AO-50" manufactured by ADEKA CORPORATION
・ Phenolic antioxidant (2)
“IRGANOX 1010” manufactured by BASF Japan Ltd.
・ Sulfur-based antioxidant "NOCRACK 400S" manufactured by Ouchi Shinsei Chemical Co., Ltd.

・ Carbon black “# 60” made by Asahi Carbon

Example 1
<Manufacture of rubber-based resin closed cell foam sheet>
Acrylonitrile-butadiene rubber (1) (NBR, manufactured by Nippon Zeon Co., Ltd., trade name “Nipol 1041”, density 1.00 g / cm ³ , acrylonitrile component amount: 40.5 mass%) 100 mass parts, ADCA (2) ( A foamable resin composition comprising 15 parts by mass of azodicarbonamide) and 0.1 parts by mass of powdered phenolic antioxidant (2) (“IRGANOX 1010” manufactured by BASF Japan Ltd.) was kneaded with a pressure kneader. .
Next, after the foamable resin composition is supplied to an extruder and melt-kneaded, a foamable resin sheet is produced by extruding the molten foamable resin composition from the extruder at an extrusion rate of 50 kg / hour. did. The acrylonitrile-butadiene rubber (1) was not liquid at 20 ° C. and 1 atmosphere (1.01 × 10 −1 MPa) but had rubber elasticity.
Subsequently, the foamed resin sheet was cross-linked by irradiating both surfaces of the foamable resin sheet with 1.2 Mrad of ionizing radiation at an applied voltage of 500 keV.
Then, the foamed resin sheet in a crosslinked state is supplied into a foaming furnace and heated at 240 ° C., thereby foaming the foaming agent in the foamable resin sheet, the apparent density is 33 kg / m ³ , and the closed cell ratio is 92. %, And a rubber-based resin closed cell foam sheet having a thickness of 5.0 mm was obtained.

<Manufacture of closed cell foam waterproofing sheet with adhesion layer>
100 parts by mass of butyl rubber (1), 0.7 parts by mass of phenol-based antioxidant (2), 0.3 parts by mass of sulfur-based antioxidant, 3 parts by mass of carbon black, petroleum resin-based tackifier (1) 5 A mixture containing parts by mass is continuously charged into the extruder and melt-kneaded in the extruder. The resin pressure of the molten resin is 250 kg / cm ² , the pinch pressure is 0.1 kg / cm ² , and the pinch roll temperature is 50. A method of adhering to a rubber-based resin closed-cell foam sheet at 0 ° C. (by extrusion molding) to obtain a closed-cell foam water-stop sheet with an adhesive layer. The thickness of the adhesion layer was 0.15 mm.

Examples 1-15 and Comparative Examples 1-5
It is the same as that of Example 1 except having set it as the mixing | blending of Tables 1-3, and having become the thickness and apparent density of the rubber-type resin closed-cell foam sheet of Tables 1-3, and the thickness of an adhesion layer. The water stop sheet was obtained by the method. In Tables 1 to 3, parts other than numerical values with unit descriptions indicate parts by mass.

Examples 16-20
<Manufacture of rubber-based resin closed cell foam sheet>
Acrylonitrile-butadiene rubber (2) (NBR, manufactured by Nippon Zeon Co., Ltd., trade name “Nipol 1042”, density 0.98 g / cm ³ , acrylonitrile component amount: 33.5 mass%) 100 parts by mass, liquid acrylonitrile-butadiene rubber (Liquid NBR, Nippon Zeon Co., Ltd., trade name “Nipol 1312”, density: 0.98 g / cm ³ ) 3 parts by mass, ADCA (2) (azodicarbonamide) 15 parts by mass and powdery phenolic antioxidant A foamable resin composition consisting of 0.1 part by mass of agent (2) (“IRGANOX 1010” manufactured by BASF Japan Ltd.) was kneaded with a pressure kneader. The acrylonitrile-butadiene rubber was not liquid at 20 ° C. and 1 atm (1.01 × 10 ⁻¹ MPa) but had rubber elasticity. The liquid acrylonitrile-butadiene rubber was fluid under the conditions of 20 ° C. and 1 atmosphere (1.01 × 10 ⁻¹ MPa). A rubber-based resin closed cell foam sheet was obtained in the same manner as in Example 1 except that this resin composition was used. Closed cells were prepared in the same manner as in Example 1 except that the composition was as shown in Table 2 and the thickness and apparent density of the rubber-based resin closed cell foam sheet described in Table 2 were set to the thickness of the adhesion layer. A foam waterproofing sheet was obtained.

Comparative Example 6
Without sticking the adhesion layer, the rubber-based resin closed cell foam sheet of Example 1 was obtained as a closed cell foamed rubber sheet.

[Evaluation]
About the water-stop sheet produced in the Examples and Comparative Examples and the closed-cell foamed rubber sheet of Comparative Example 6, the peel adhesion, the water-stop against high water pressure, 25% compression stress, the adhesion layer and the closed-cell foam sheet The adhesiveness, reworkability, moldability (warpage), and extrusion moldability of the adhesion layer were evaluated. The results are shown in Tables 1 and 2.

<Peel adhesion evaluation>
-Evaluation method Each water-stop sheet obtained in Examples and Comparative Examples and the closed-cell foamed rubber sheet of Comparative Example 6 were cut into a width of 25 mm and a length of 300 m to prepare test pieces. After adhering the adhesion layer of this test piece to an acrylic plate, it was compressed 50% with a coated steel plate having a thickness of 10 mm and left at 23 ° C. for 1 hour. After 1 hour, the compression was released, and the test piece was folded 180 ° with the gripping margin. The margin of the 180 ° folded test piece is gripped by a universal material testing machine (A & D Co., Ltd., Tensilon universal material testing machine, RTF-1310), and at a pulling speed of 5.0 ± 0.2 mm / sec. Move the tensile tester to start the measurement, ignore the first 25% length measurement after starting the measurement, and then measure the 50% length adhesive strength peeled off from the acrylic board The values were averaged and the peel adhesive strength (peel adhesion (N / 25 mm)) in the 180 ° direction was measured.

<Evaluation of water stoppage against high water pressure>
-Preparation of a ring-shaped test body Double-sided tape (Sekisui Chemical Co., Ltd.) on the surface opposite to the adhesion layer of each water-stop sheet obtained in Examples and Comparative Examples and on one surface of the closed-cell foamed rubber sheet of Comparative Example 6 "# 5782" manufactured by Kogyo Co., Ltd. is pasted and processed into a ring shape with an inner diameter of 40 mm, an outer diameter of 60 mm, and a seal width (thickness) of 10 mm, and a ring-shaped specimen (A) or an inner diameter of 45 mm, outer A ring-shaped specimen (B) was obtained by processing into a ring shape having a diameter of 55 mm and a seal width (thickness) of 5 mm.
The ring-shaped test body (A) and the ring-shaped test body (B) were used as a ring-shaped test body used for evaluation of water-stopping performance against high water pressure.
-Production of test apparatus A Next, two acrylic plates having a length of 100 mm, a width of 100 mm, and a thickness of 10 mm, each having a hole for passing a bolt through four corners, were prepared.
A through hole having a diameter of about 10 to 20 mm was formed at the center of one acrylic plate, and a hose was connected to the through hole. An acrylic ring-shaped column having an inner diameter of 40 mm, an outer diameter of 60 mm, and a thickness of 10 mm was fixed to the surface of the acrylic plate opposite to the surface to which the hose was connected with a double-sided tape (“# 5782” manufactured by Sekisui Chemical Co., Ltd.). .
The ring-shaped test body was fixed on the ring-shaped column with a double-sided tape, and the ring-shaped test body was arranged so that the adhesion layer of the ring-shaped test body was in contact with the other acrylic plate. One acrylic plate arranged in the order of one acrylic plate, ring-shaped column, ring-shaped test body, and the other acrylic plate and the other acrylic plate were fixed with bolts and nuts. At this time, the gap between one acrylic plate and the other acrylic plate is measured with a caliper or the like, and the ring-shaped specimen is compressed so that the compression ratio of the ring-shaped specimen is 35%. Was fixed as a test apparatus A.
Evaluation Method The test apparatus A in a state where a ring-shaped specimen having a compression rate of 35% was held was left at 23 ° C. for 1 hour. After standing, a high-pressure washing machine (Kelcher Japan Co., Ltd.) from a position 50 cm away from the test apparatus A so that running water hits at an angle of about 30 ° with respect to the compression direction of the ring-shaped specimen held in the test apparatus A Water was discharged for 30 seconds using K5.20M plus, water volume: 370 L / hour, discharge port water pressure: 8 MPa, spray shape: fan shape.
After 30 seconds of water discharge, if water does not appear inside the ring-shaped specimen (inner diameter) and water does not come out from the hose connected to the acrylic plate, the same position from 40 cm away from the test apparatus A Under the conditions, water was discharged again from the high pressure washer for 30 seconds. In this way, water discharge was repeated until water was found inside the ring-shaped test body (inner diameter) while reducing the distance between the test apparatus A and the high pressure washer. When the distance between the test apparatus A and the high pressure washer was 30 cm or less, the test was repeated while reducing the distance between the test apparatus A and the high pressure washer by 5 cm. The water-stopping property against high water pressure was measured by measuring the distance between the test apparatus A and the high-pressure washing machine in which water immersion was observed inside the ring-shaped specimen (inner diameter), and evaluating the water-stopping property against high water pressure according to the length of the distance. .
-Criteria When the distance between the test apparatus A and the high-pressure washing machine is 30 cm or less, it was evaluated that the water-proofing property can withstand the water pressure discharged from the high-pressure washing machine. In addition, when the distance between the test apparatus A and the high pressure washer was 20 cm or less, it was evaluated that it had a waterstop property that could withstand the water pressure discharged from the high pressure washer and that the waterstop property was good. When the distance between the test apparatus A and the high-pressure washer was 15 cm or less, it was evaluated that the water-stopper was able to withstand the water pressure discharged from the high-pressure washer and that the water-stopper was even better. When the distance between the test apparatus A and the high-pressure washing machine was 10 cm or less, it was evaluated that the water-stopping property was able to withstand the water pressure discharged from the high-pressure line and that the water-stopping property was the best. When the distance between the test apparatus A and the high-pressure washing machine is the same length, the smaller the seal width (thickness) of the ring-shaped test body, the better the water stoppage.

<25% compressive stress evaluation>
Measurement method Each water-stop sheet obtained in Examples and Comparative Examples and the closed-cell foamed rubber sheet of Comparative Example 6 were cut into a length of 30 mm and a width of 30 mm to produce a test piece. A sample was prepared by laminating to form a 25 mm rectangular parallelepiped. Stress when a sample is sandwiched between plates larger than the sample and compressed at a speed of 10 mm / min at a temperature of 23 ° C. to be 18.75 mm (compressed to 25% of the original thickness) (Strain) was measured with a universal material testing machine (manufactured by A & D Co., Ltd., Tensilon universal material testing machine, RTF-1310).

<Evaluation of adhesion between adhesive layer and closed cell foam sheet>
Evaluation Method The water-stop sheets obtained in Examples and Comparative Examples and the closed-cell foamed rubber sheet of Comparative Example 6 were performed in accordance with the tensile strength test B method of JIS K 6767-1995.
Specifically, the test piece is a cuboid having a length of 50 mm, a width of 50 mm, and a thickness of 10 mm. After measuring the thickness of the test piece at the center, the test piece is sandwiched between jigs, and both sides of the water-stop sheet are attached. It bonded to the jig | tool with the same double-sided tape (Sekisui Chemical Co., Ltd. "# 5782"). After the bonding was completed, a tensile test was performed at a tensile speed of 10 mm / min.
・ Standard G: 1 kgf / cm ² or more (good adhesion)
B: When less than 1 kgf / cm ² (insufficient adhesion)

<Reworkability evaluation>
-Evaluation method Each water-stop sheet obtained in Examples and Comparative Examples and the closed-cell foamed rubber sheet of Comparative Example 6 were cut into a width of 25 mm and a length of 300 m to prepare test pieces. After adhering the adhesion layer of this test piece to an acrylic plate, it was compressed 50% with a coated steel plate having a thickness of 10 mm and left at 23 ° C. for 1 hour. After 1 hour, the compression was released, and the specimen was folded back 180 ° with a grab margin. The margin of the 180 ° folded test piece is gripped by a universal material testing machine (A & D Co., Ltd., Tensilon universal material testing machine, RTF-1310), and at a pulling speed of 5.0 ± 0.2 mm / sec. Start the measurement, ignore the first 25% length measurement after starting the measurement, and then average the 50% length adhesive strength peeled off from the acrylic board to peel The force (peel adhesion (N / 25 mm)) was measured. This measurement was performed 5 times and evaluated according to the following criteria.
G: When the adhesion layer of the water-stop sheet did not cohesively break in all 5 times. B: When the adhesion layer of the water-stop sheet coheses and breaks even once in 5 times. When the adhesion layer of the water sheet was agglomerated, the subsequent evaluation was not performed.

<Evaluation of formability (warpage)>
Each water-stop sheet obtained in Examples and Comparative Examples is cut into 500 mm × 500 mm and placed on a flat table, and a part of the cut closed-cell foam water-stop sheet is separated from the table by 15 mm or more and is it floating? It was confirmed visually and evaluated.
・ Standard G: When there is no warping B: When there is warping

<Evaluation of extrudability of adhesion layer>
Evaluation method After kneading using a Banbury mixer according to the formulation of the adhesion layer described in Tables 1 to 3, an extruded sheet was formed with an extruder under the condition of 80 kg / hr, and the thickness of the obtained extruded sheet was averaged. The thickness was measured. Next, 10 points were measured at 10 cm intervals in the width direction of the extruded sheet, and the absolute value of the difference from the average thickness was calculated for each point. Concavities and convexities were evaluated according to the following criteria for the number of measured values where the absolute value was 20% or more of the average thickness.
Reference G: When the absolute value that is 20% or more of the average thickness is 0 B: When the absolute value that is 20% or more of the average thickness is 1 or more

  As is apparent from the results shown in Tables 1 to 3, according to the present invention, while maintaining excellent moldability, moderate compression flexibility and reworkability, for example, it can withstand washing at a high water pressure of 5 MPa or more. A water stop sheet having excellent adhesion and water stop could be obtained. As shown in Table 2, by changing the components of the adhesion layer, the reworkability and the extrusion moldability of the adhesion layer may be slightly inferior, but these examples also have a higher water pressure cleaning than the comparative examples. The waterstop was good. Moreover, as shown in Table 3, the water-stop sheet of Comparative Examples 1 to 5 and the closed-cell foamed rubber sheet of Comparative Example 6 sometimes had poor moldability and reduced water-stop performance against high water pressure cleaning. .

Claims (7)

  Including a rubber component (A) and a petroleum resin-based tackifier (B) having a total content of butyl rubber (a1) and ethylene-propylene-diene rubber (a2) of 80% by mass or more, and having a thickness of 0.01 to 2 The foaming agent is foamed in a state in which an adhesion layer of 0.0 mm, an acrylonitrile-butadiene rubber containing 33.5 to 50% by mass of an acrylonitrile component and a foaming resin sheet containing a foaming agent are cross-linked by irradiation with ionizing radiation. A closed-cell foamed water-stop sheet with an adhesive layer in which a rubber-based resin closed-cell foam sheet is closely adhered, and a mass ratio of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) [(a2) / (A1)] is 0/100 to 93/7, and the content of the petroleum resin tackifier (B) with respect to 100 parts by mass of the rubber component (A) is 0.00. A 20 parts by weight, the adhesion layer with closed cell foam waterproofing sheet. The rubber-based resin closed-cell foam sheet has rubber elasticity at 20 ° C. and 1.01 × 10 ⁻¹ MPa, and contains acrylonitrile-butadiene rubber in an amount of 33.5 to 50% by mass, 100% by mass. The closed-cell foam with a close_contact | adherence layer of a liquid acrylonitrile-butadiene rubber which has a fluidity | liquidity under 20 degreeC and 1.01 * 10 < ^-1 > MPa of a part. Water stop sheet. The closed cell foam waterproofing sheet with an adhesion layer according to claim 1 or 2, wherein the apparent density of the closed cell foam sheet is 15 to 700 kg / m ³ .   The closed cell foam water-stop sheet with an adhesion layer according to any one of claims 1 to 3, wherein the butyl rubber (a1) has a Mooney viscosity ML (1 + 8) at 125 ° C of 20 to 60.   The closed cell foam waterproofing sheet with an adhesion layer according to any one of claims 1 to 4, wherein the closed cell foam sheet has a thickness of 0.05 to 15 mm.   The closed cell foam waterproofing sheet with an adhesion layer according to any one of claims 1 to 5, wherein the adhesion layer has a thickness of 0.03 to 1.0 mm.   The closed cell foam water-stop sheet with an adhesion layer according to any one of claims 1 to 6, wherein the mass ratio [(a2) / (a1)] is from 1/99 to 90/10.