JPWO2017170827A1 - Closed cell foam waterproofing sheet with adhesion layer - Google Patents

Abstract

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 A close contact layer having a thickness of 0.0 mm and a closed cell foam sheet having a closed cell ratio of 70% or more are adhered to each other, and the closed cell foam sheet has a thermoplastic resin or a rubber-based resin, a weather resistance agent, and a foam. The foamable resin composition containing an agent is foamed, and the content of the weathering agent is 0.1 to 8.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin or rubber-based resin, and the butyl rubber ( The mass ratio of the ethylene-propylene-diene rubber (a2) to 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) is 0. .5-20 A quantity unit, 25% compressive stress is 10～800KPa, adhesion layer with closed cell foam waterproofing sheet.

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 industrial fields such as architecture, vehicles, and electronics, a waterproof seal material made of foam is widely used in order to fill a gap between various structures and casings 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. . However, if the compressibility of the water-stopping sealing material is low, the repelling stress of the water-stopping sealing material will be too strong, and damage or deformation may occur in the adherend part. The problem of becoming insufficient arises.
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.
For example, Patent Documents 1 and 2 describe a water-stop sealing material using a rubber-based resin closed-cell foam sheet having closed cells as a water-stop seal material that solves this problem.
In addition to this, in recent years, not only the above-mentioned basic characteristics as a waterproof seal material but also a demand for further improvement of weather resistance in vehicle applications has been rapidly increased.

International Publication No. 2007/072885 International Publication No. 2011/039877

The rubber-based resin closed cell foam sheets described in Patent Documents 1 and 2 are excellent in moldability and have strong adhesion to the adherend, and on the other hand, the sheet is attached to a product. At that time, the peelability and re-stickability (hereinafter also referred to as “reworkability”) were improved to some extent so that the attachment position could be finely corrected. However, sufficient consideration has not been given to the requirement of weather resistance in vehicle applications. The present inventors considered that the weather resistance can be solved by simply adding a weathering agent to the closed-cell foam water-stop sheet, and studied a plurality of weathering agents. However, in general, crosslinking is often performed by electron beam crosslinking from the viewpoint of sulfur contamination and foaming ratio improvement, and the original function of the weathering agent is attenuated in the electron beam irradiation or foaming process. It came to the result that the effect of was not obtained.
The present invention has been made in view of the above, and has closed cells with an adhesion layer that have good moldability and reworkability, high adhesion to the adherend surface, excellent water blocking properties, and excellent weather resistance. A foam waterproof sheet is 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. A closed cell foam water-stop sheet with an adhesion layer in which an adhesion layer of .01 to 2.0 mm and a closed cell foam sheet having a closed cell ratio of 70% or more are adhered to each other;
The closed cell foam sheet is obtained by foaming a foamable resin composition containing a thermoplastic resin or a rubber resin and a weathering agent and a foaming agent, and the content of the weathering agent is the thermoplastic resin or rubber system. 0.1 to 8.0 parts by mass with respect to 100 parts by mass of the resin, and the mass ratio [(a2) / (a1)] of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) is 0/100 to 93/7, the content of the petroleum resin tackifier (B) with respect to 100 parts by mass of the rubber component (A) is 0.5 to 20 parts by mass, and the 25% compression stress is 10 to 800 kPa. The gist of the closed cell foam water-stop sheet with an adhesive layer.

  According to the present invention, there is provided a closed-cell foam water-stop sheet with an adhesive layer that has good moldability and reworkability, has high adhesion to the adherend surface, is excellent in water-stopping properties, and is also excellent in weather resistance. be able to.

  The closed cell foam water-stop sheet with an adhesive layer of the present invention comprises 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. Closed cell foam with an adhesive layer comprising an adhesive (B) and having an adhesive layer having a thickness of 0.01 to 2.0 mm and an closed cell foam sheet having a closed cell ratio of 70% or more It is a water sheet, and the closed-cell foam sheet is formed by foaming a foamable resin composition containing a thermoplastic resin or a rubber-based resin, a weathering agent and a foaming agent, and the content of the weathering agent is 0.1 to 8.0 parts by mass with respect to 100 parts by mass of the plastic resin or rubber resin, and the mass ratio of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) [(a2) / (a1)] Is 0/100 93/7, the content of the petroleum resin tackifier (B) with respect to 100 parts by mass of the rubber component (A) is 0.5 to 20 parts by mass, and the 25% compression stress is 10 to 800 kPa. It is a closed cell foam waterproofing sheet with an adhesion layer.

[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 tackifier (B) are used in the adhesion layer, an closed cell foam sheet with an adhesion layer excellent in reworkability and water-stopping property is provided. Can do.

<Rubber component (A)>
The rubber component (A) in the present invention has a total content of butyl rubber (a1) and ethylene-propylene-diene rubber (a2) of 80% by mass or more. When 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 is 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, further 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 85/15, more preferably 2/98 to 70/30, from the viewpoints of moldability, reworkability, and water stopping properties. Preferably it is 3 / 97-50 / 50, More preferably, it is 5 / 95-30 / 70.

(Butyl rubber (a1))
In addition to butyl rubber (IIR), halogenated butyl rubber can also be used as butyl rubber (a1) 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 further 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 (EPM) which is a copolymer of ethylene and propylene, and a double bond is provided in the main chain. Examples of the third component include ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), and dicyclopentadiene (DCP).
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 present invention, the petroleum resin-based tackifier (B) is used for the purpose of improving the adhesion to the adherend surface of the closed cell foam water-stop sheet with an adhesion layer. The petroleum resin tackifier (B) in the present invention refers to a tackifier obtained by cationic polymerization of a fraction containing an unsaturated hydrocarbon obtained by thermal decomposition of petroleum naphtha or the like.
In the present invention, when the petroleum resin-based tackifier (B) is used, it is not clear why the adhesion to the adherend surface of the closed cell foam waterproofing sheet with the adhesion layer is improved, but the petroleum resin-based tackifier This is considered to be due to the good dispersibility of the rubber component in the rubber component.

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, ginclopentadiene petroleum resin tackifiers, and tackifiers composed of these hydrides.
Among these, C5 petroleum resin tackifier, C9 from the viewpoint of improving the adhesion with the adherend surface of the closed cell foam water-stop sheet with an adhesion layer and the compatibility with the rubber component (A). -Based petroleum resin tackifiers and C5-C9 copolymerized petroleum resin tackifiers are preferred, and C5-based petroleum resin tackifiers are 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.

[Closed-cell foam sheet]
The closed cell foam sheet used in the present invention is obtained by foaming a foamable resin composition containing a thermoplastic resin or a rubber-based resin, a weathering agent and a foaming agent (foam), and has a closed cell ratio of 70. It is a closed cell foam sheet produced by a method in which the foamable resin composition is formed into a sheet, crosslinked by ionizing radiation, and then foamed through a heating furnace.
From the viewpoint of water-stopping properties, it is preferable that the thermoplastic resin is a foamed olefin resin or a foamed rubber resin, more preferably a foamed olefin resin.

<Olefin resin>
Examples of the olefin resin used as the raw material for the closed cell foam sheet include polyethylene resin, polypropylene resin, propylene-ethylene block copolymer, ethylene-α-olefin copolymer containing ethylene as a main component, and propylene. One or more kinds selected from propylene-α-olefin copolymer having a main component, ethylene-propylene-butene terpolymer having propylene as a main component, polybutene and polymethylpentene are preferable.

Examples of the polyethylene resin include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer containing ethylene as a main component, and ethylene-ethyl containing ethylene as a main component. An acrylate copolymer etc. are mentioned.
Examples of the α-olefin constituting the ethylene-α-olefin copolymer include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene and 1-octene. Can be mentioned.
Examples of the α-olefin constituting the propylene-α-olefin copolymer include ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene and the like. Can be mentioned. These olefinic resins may be used alone or in combination of two or more.
Among these, from the viewpoint of improving water-stopping properties, low-density polyethylene and high-density polyethylene are preferable, and it is preferable to use a mixture of low-density polyethylene and high-density polyethylene.

<Rubber resin>
As the rubber-based resin, acrylonitrile-butadiene rubber is preferable from the viewpoint of improving the water-stopping property. The acrylonitrile-butadiene rubber preferably has an acrylonitrile component content of 30 to 50% by mass, more preferably 35 to 50% by mass, and still more preferably 40 to 45% by mass. When the content of the acrylonitrile component is within the above range, the water stoppage is improved. In addition, when using multiple types acrylonitrile-butadiene rubber, let the weight average value be content of an acrylonitrile component.

  The rubber other than acrylonitrile-butadiene rubber constituting the rubber-based resin is not particularly limited as long as it has rubber elasticity at room temperature (25 ° C.). For example, chloroprene rubber (CR), isoprene rubber ( IR), butyl rubber (IIR), natural rubber, styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), ethylene-propylene-diene rubber (EPDM), urethane rubber, fluorine rubber, acrylic rubber, and silicone rubber. Can be mentioned. These may be used alone or in combination of two or more.

<Foaming agent>
As the foaming agent, a thermal decomposition type foaming agent that decomposes by heat to generate gas is preferable. Examples of the thermally decomposable foaming agent include azodicarbonamide, benzenesulfonylhydrazide, dinitrosopentamethylenetetramine, toluenesulfonylhydrazide, 4,4-oxybis (benzenesulfonylhydrazide), and the like. These may be used alone or in combination of two or more.
The amount of the pyrolytic foaming agent is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and further preferably 5 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin or rubber-based resin. is there. When the blending amount of the pyrolytic foaming agent is within the above range, it is possible to obtain a closed-cell foamed water-stop sheet with an adhesive layer having excellent water-stopping properties over a long period of time.

<Weathering agent>
The closed cell foam sheet of the present invention contains a weathering agent as an essential component. The weathering agent is not particularly limited as long as the original function is not attenuated or lost in the electron beam irradiation process.
Examples of the weathering agent include carbon black, a radical scavenger, and a radical chain initiation inhibitor. From the viewpoint of weather resistance, carbon black alone or at least one selected from carbon black, a radical scavenger and a radical chain initiation inhibitor is preferable.

  Content of the said weathering agent is 0.1-8.0 mass parts with respect to 100 mass parts of the said thermoplastic resins or rubber-type resin. When the content of the weathering agent is within the above range, the weather resistance is excellent while maintaining the original basic characteristics (see evaluation items of Examples described later) possessed by the closed cell foam water-stop sheet with an adhesion layer. A closed-cell foam water-stop sheet with an adhesion layer can be obtained. Preferably it is 0.2-7.8 mass parts, More preferably, it is 0.5-6.0 mass parts, More preferably, it is 1.0-5.2 mass parts, More preferably, it is 2.0-5.0 masses. Part.

Carbon black is not particularly limited, and examples thereof include acetylene black, ketjen black, furnace black, channel black, and thermal black. Among these, furnace black is preferable from the viewpoint of processing characteristics. Carbon black may be used alone or in combination of two or more carbon blacks.
Moreover, the average particle diameter of carbon black is preferably 8 to 60 μm, and more preferably 10 to 50 μm. In addition, the average particle diameter of the carbon black used for this invention was computed with the electron microscope (SEM observation).

As the radical scavenger, a hindered amine light stabilizer is preferable.
Examples of hindered amine light stabilizers (HALS) include 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2′-n-butylmalonate bis (1,2,2,6, 6-pentamethyl-4-piperidyl), bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis ( 2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) butane-1 , 2,3,4-Tetracarboxylate (ADK STAB LA-52), 1,2,3,4-butanetetracarboxylic acid, tetramethyl ester, 1,2,2,6,6-pentamethyl Reaction product of -4-piperidinol and β, β, β ′, β′-tetramethyl-2,4,8,10-tetraoxaspiro [5.5] undecane-3,9-diethanol (Adekastab LA- 63P). Among these, from the viewpoint of thermal stability, 1,2,3,4-butanetetracarboxylic acid, tetramethyl ester, 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β The reaction product (Adekastab LA-63P) with ', β'-tetramethyl-2,4,8,10-tetraoxaspiro [5.5] undecane-3,9-diethanol is preferred, and tetrakis (1,2 , 2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate (ADK STAB LA-52) is more preferred.

The radical chain initiation inhibitor is preferably an ultraviolet absorber (UVA).
Although UVA itself does not have antioxidant ability, it can detoxify light degradation factors and suppress the initiation of chain reaction. UVA absorbs in the ultraviolet region and is rendered harmless by converting the absorbed ultraviolet energy into thermal energy.
Examples of UVA include benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, salicylate ultraviolet absorbers, and cyanoacrylate ultraviolet absorbers.
Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) benzotriazole and 2- (5-chloro-2H-benzotriazol-2-yl) -6-tert-butyl-4. -Methylphenol (Adekastab LA-36), 2- (2-hydroxy-3,5-di-tert-amylphenyl) benzotriazole, polyethylene glycol 3- [3- (benzotriazol-2-yl) -5- tert-butyl-4-hydroxyphenyl] propionic acid ester and the like.
Examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-benzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy- Examples include benzophenone-5-sulfonic acid.
Examples of the triazine-based ultraviolet absorber include 2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 85% 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -5-hydroxyphenyl and oxirane [(C10-C16 mainly C12-C13 alkyloxy) methyl] oxirane Reaction product of 2- (2,4-dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine with (2-ethylhexyl) -glycidic acid ester Product, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] phenol, 1,3,5-triazine-2,4 (IH, 3H, 5H) - trione, 1,3,5 [[3,5-bis - (1,1-dimethylethyl) -4-hydroxyphenyl] methyl], and the like.
Examples of salicylate ultraviolet absorbers include phenyl salicylate and 4-t-butylphenyl salicylate.
Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3′-diphenyl acrylate, 2-ethylhexyl-2-cyano-3,3′-diphenyl acrylate, and the like.
Examples of the oxanilide ultraviolet absorber include 2-ethoxy-2′-ethyloxalic acid bisanilide, 2-ethoxyn-5-t-butyl-2′-ethyloxalic acid bisanilide, and the like.
Among these, 2- (5-chloro-2H-benzotriazol-2-yl) -6-tert-butyl-4-methylphenol (ADK STAB LA-36) is preferable from the viewpoint of thermal stability.

<Additives used for closed-cell foam sheets>
The closed cell foam sheet 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 closed cell foam sheet>
The thickness of the 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 further preferably 1 to 8 mm. It is preferable for the thickness to be in the above-mentioned range since warpage is unlikely to occur.

<Apparent density of closed cell foam sheet>
From the viewpoint of improving the flexibility of the closed cell foam sheet, the apparent density of the closed cell foam sheet is preferably 15 to 700 kg / m ³ , more preferably 17 to 600 kg / m ³ , and still more preferably 20 to 500 kg / m. m is ^3. When the apparent density is within the above range, the repulsive force does not become too high, so that the workability is improved. In addition, even when the apparent density of the closed cell foam sheet is high, it can be used by lowering the compressibility.

<Closed cell ratio of closed cell foam sheet>
The closed cell foam sheet used in the present invention has a closed cell ratio of 70% or more, and some of the cells 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.
In addition, the closed cell rate in this invention says what was measured in the following ways.
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 of the water, the water 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 formulas. To do.
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 sheet>
The method for producing the closed cell foam sheet used in the present invention is not particularly limited, but a foamable resin composition containing a thermoplastic resin or rubber resin, a weathering agent and a foaming agent, and optional additives is kneaded into a sheet shape. It is preferable to prepare a foamable resin sheet by molding, then cross-link with ionizing radiation or the like, and then foam by passing through a heating furnace.
[Method for producing foamable resin sheet]
As a 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 extruded by an extruder, a calender, a conveyor belt casting or the like. The method of manufacturing a foamable resin sheet by this is mentioned.

[Crosslinking method of foamable resin sheet]
Next, as a crosslinking method of the foamable resin sheet, crosslinking by ionizing radiation can be mentioned.
In the case of crosslinking with ionizing radiation, examples of the ionizing radiation include light, γ-rays, and electron beams. The irradiation amount of ionizing radiation is preferably 0.5 to 15 Mrad, more preferably 0.7 to 10 Mrad.
When cross-linking is performed by ionizing radiation, a closed cell foam sheet having a uniform cell with a small diameter can be obtained. Such a closed cell foam sheet having a small diameter and uniform bubbles has a smooth surface, a large contact area with respect to the adherend surface, and improved adhesion, and thus has excellent water-stopping properties.

[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.

[25% compressive stress of closed cell foam waterproofing sheet with adhesion layer]
The 25% compressive stress of the closed cell foam waterproofing sheet with an adhesive layer of the present invention is 10 to 800 kPa, preferably 20 to 700 kPa, more preferably 25 to 500 kPa. When the 25% compressive stress of the closed cell foam water-proof sheet with the adhesion layer is within the above range, the workability is improved and the assemblability is improved. In addition, 25% compressive stress can be measured by the method as described in an Example.

[Method for producing closed-cell foam water-stop sheet with adhesion layer]
Although there is no restriction | limiting in particular in the manufacturing method of the closed-cell foam waterproofing sheet with an adhesion layer of this invention, It manufactures by laminating | stacking the closed-cell foam sheet manufactured by the said method, and the adhesion layer manufactured by the said method. be able to.
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.

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)
“BUTYL065” manufactured by JSR Corporation
Mooney viscosity ML (1 + 8) 125 ° C. = 32
・ Ethylene-propylene-diene rubber “EP21” manufactured by JSR Corporation
Mooney viscosity ML (1 + 4) 125 ° C. = 26

・ Low density polyethylene (LDPE)
"Novatec LE520H" manufactured by Japan Polyethylene Corporation

・ 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.

・ ADCA (azodicarbonamide)
"Unihome SO-G3IST" manufactured by Otsuka Chemical Co., Ltd.
・ Zinc stearate “ZP” manufactured by Dainichi Chemical Co., Ltd.

・ Phenolic antioxidant (1)
"ADEKA STAB AO-60P" manufactured by ADEKA CORPORATION
・ Phenolic antioxidant (2)
"ADEKA STAB AO-50" manufactured by ADEKA CORPORATION
・ Sulfur-based antioxidant "NOCRACK 400S" manufactured by Ouchi Shinsei Chemical Co., Ltd.
・ Carbon black (for adhesion layer)
"# 60" made by Asahi Carbon Co., Ltd.

・ Lubricant “KP720B” manufactured by Sakai Chemical Industry Co., Ltd.
・ Deactivator “ADEKA STAB CDA-1” manufactured by ADEKA Corporation
・ Titanium oxide “SR-1” manufactured by Sakai Chemical Industry Co., Ltd.

・ Carbon black (for foam layer)
“AP09799 Black” manufactured by Dainichi Seika Co., Ltd.
・ Radical scavenger 1
Hindered amine light stabilizer "ADEKA STAB LA52" made by ADEKA Corporation
・ Radical scavenger 2
Hindered amine light stabilizer "ADEKA STAB LA63P" manufactured by ADEKA Corporation
・ Radical chain initiation inhibitor UV absorber “ADEKA STAB LA36” manufactured by ADEKA Corporation

Example 1
<Manufacture of closed cell foam sheet>
100 parts by weight of low density polyethylene, 10 parts by weight of ADCA, 0.5 parts by weight of phenolic antioxidant (1), 2.0 parts by weight of zinc stearate, 5.0 parts by weight of carbon black, 1 part by weight of lubricant, inert A mixture containing 0.5 parts by mass of the agent and 1 part by mass of titanium oxide was continuously charged into the extruder, and melt-kneaded and extruded by the extruder to obtain an uncrosslinked / unfoamed sheet.
By irradiating the obtained sheet with an electron beam having a dose of 2.9 Mrad and an acceleration voltage of 800 kV, a crosslinked / non-foamed sheet was obtained.
The obtained crosslinked / non-foamed sheet is heated to 240 ° C. in a foaming furnace to decompose and foam ADCA (azodicarbonamide), whereby an apparent density of 35 kg / m ³ (the apparent density conforms to JIS K 7222). ), An closed cell foam sheet having an average thickness of 5.0 mm and a variation in thickness in the width direction within ± 20% of the average thickness was obtained. In addition, about the variation in the said thickness, it measured by the method similar to the extrusion moldability evaluation of the below-mentioned contact | adherence layer.

<Manufacture of closed cell foam waterproofing sheet with adhesion layer>
70 parts by mass of butyl rubber [component (a1)] 1, 30 parts by mass of ethylene-propylene-diene rubber [component (a2)] 2, 0.7 parts by mass of phenol-based antioxidant (2), sulfur-based antioxidant 0 3 parts by mass, 3 parts by mass of carbon black, and 5 parts by mass of petroleum resin-based tackifying resin [component (B)] 1 were continuously added to the extruder and melt-kneaded in the extruder. Closed cell foam with adhesion layer by a method (extrusion molding) of adhering to a closed cell foam sheet with a resin pressure of the molten resin of 250 kg / cm ² , a pinch pressure of 0.1 kg / cm ² and a pinch roll temperature of 50 ° C. A waterproof sheet was obtained. The thickness of the adhesion layer was 0.15 mm.

Example 2
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 1 except that the carbon black and the foaming agent were blended as shown in Table 1.

Example 3
Closed-cell foam waterproofing sheet with an adhesive layer by the same method as in Example 1 except that the amount of carbon black was reduced and the radical scavenger 1 and radical chain initiation inhibitor were added to obtain the formulation shown in Table 1. Got.

Example 4
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 3 except that the radical scavenger 1 was changed to the radical scavenger 2 and the formulation shown in Table 1 was used.

Example 5
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 3 except that the radical scavenger 1, radical chain initiation inhibitor and foaming agent were blended as shown in Table 1.

Example 6
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 3 except that the radical scavenger 1, radical chain initiation inhibitor and foaming agent were blended as shown in Table 1.

Comparative Example 1
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 1 except that the carbon black and the foaming agent were blended as shown in Table 1.

Comparative Example 2
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 3 except that the radical scavenger 1, radical chain initiation inhibitor and foaming agent were blended as shown in Table 1.

Comparative Example 3
A closed cell foam water-stop sheet with an adhesive layer was obtained in the same manner as in Example 1 except that carbon black was formulated as shown in Table 1.

[Evaluation]
The weather resistance test was performed on the closed-cell foamed water-stop sheet with an adhesive layer produced in the examples and comparative examples under the following conditions.
<Weather resistance evaluation>
Evaluation method In accordance with JIS B7753 (2007), a sunshine weather meter (Suga Test Instruments Co., Ltd., “model number: S80”; sunshine carbon arc (ultra long life carbon 4 pair) light source) is used, and the discharge voltage is 50V. The discharge current is set to 60 A, irradiation is performed, surface spraying (rainfall) is performed for 12 minutes per hour, and 500 hours and 1000 are applied to the surface of the test piece under the conditions of a black panel temperature of 63 ° C. and a relative humidity of 50%. Time irradiation treatment was performed. A type glass filter was used.
After the irradiation test, the evaluation method described below was used to evaluate the adhesion between the adhesion layer and the closed-cell foam sheet and the water pressure resistance by a ring water stop test. The results are shown in Table 1.
In addition, evaluation of peel adhesion, evaluation of 25% compression stress, evaluation of moldability of foam, evaluation of reworkability and evaluation of extrusion moldability were performed by the evaluation methods described below. The results are shown in Table 1.

<Peel adhesion evaluation>
-Evaluation method The closed cell foam water-stop sheet with each adhesion layer obtained in Examples and Comparative Examples was cut to a width of 25 mm and a length of 100 mm, and the adhesion layer side was attached to a vehicle coated steel sheet having a thickness of 1 mm. Thereafter, it was compressed 50% with an acrylic plate having a thickness of 10 mm, and irradiated with a sunshine weather meter for 500 hours and 1000 hours. One hour after the completion of the exposure, the compression was released and the peel adhesive strength in the 180 ° direction was measured.
Evaluation criteria In this test, the measured value is preferably 2.0 N / 25 mm or more, and more preferably 2.0 to 22.0 N / 25 mm from the viewpoint of reworkability.

<Evaluation of water pressure resistance by ring water stop test>
Evaluation method A double-sided tape (“# 5782” manufactured by Sekisui Chemical Co., Ltd.) is attached to the surface of the closed cell foam waterproofing sheet with each adhesion layer obtained in Examples and Comparative Examples on the side opposite to the adhesion layer. Combined, processed into a ring shape with an inner diameter of 40 mm and an outer diameter of 60 mm (sealing width of 10 mm), and compressed by 25% with two 10 mm thick acrylic plates having a through hole with a diameter of 10 mm in the center of one side, into a sunshine weather meter For 500 hours and 1000 hours. One hour after the completion of exposure, distilled water was filled from the through hole into the ring-shaped sealing material while maintaining the compressibility, and water pressure was applied to the inner side of the ring-shaped sealing material to determine the presence or absence of water leakage.
The water pressure is maintained at 5 kPa for 5 minutes, then the pressure is increased by 5 kPa, maintained for 5 minutes for each pressure, the pressure is increased until the water inside the ring-shaped sealing material leaks, and the maximum pressure is increased. Asked. In addition, 200 kPa was set as the upper limit of the measurement.
Evaluation criteria In this test, the measured value is preferably 10 kPa or more, and more preferably 30 kPa or more.

<25% compressive stress evaluation>
Measurement method Samples obtained by cutting the closed-cell foam water-stop sheets with adhesion layers obtained in Examples and Comparative Examples into a length of 30 mm and a width of 30 mm were subjected to irradiation treatment with a sunshine weather meter for 500 hours and 1000 hours. It was. After the exposure was completed, they were laminated to form a cuboid with a thickness of 25 mm. When the sample is sandwiched between plates with a larger area than the sample and compressed at a speed of 10 mm / min at a temperature of 23 ° C., the stress (compressed to 25% of the original thickness) (compressed to 25% of the original thickness) ( (Strain) was measured.

<Formability evaluation of foam>
Based on the value of the apparent density (measured in accordance with JIS K 7222) of the closed cell foam sheet obtained in Examples and Comparative Examples, evaluation was performed according to the following evaluation criteria.
○: In the case of 25 to 40 kg / m ^{3 in} foam molding.
(Triangle | delta): When it is the range of 41-67 kg / m < ³ > at the time of foam molding.
X: Other than the above.

<Evaluation of adhesion between adhesive layer and closed cell foam sheet>
Evaluation method Adhesive evaluation between the adhesion layer and the closed cell foam sheet of the closed cell foam water-stop sheet with the adhesion layer obtained in the examples and comparative examples was evaluated by the tensile strength test B method of JIS K 6767-1995. Performed in accordance with.
Each of the closed cell foam waterproofing sheets with adhesion layers obtained in Examples and Comparative Examples was cut into a width of 50 mm and a length of 100 mm, and the adhesion layer side was attached to an acrylic plate, and then 500 with a sunshine weather meter. Irradiation treatment was performed for 1000 hours. After the exposure is completed, the test piece is a rectangular parallelepiped 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 closed cell foam with an adhesion layer Both surfaces of the water stop sheet were bonded to a jig with the same double-sided tape (“# 5782” manufactured by Sekisui Chemical Co., Ltd.). After the bonding was completed, a tensile test was performed at a tensile speed of 10 mm / min.
-Evaluation criteria Based on the value of tensile strength, evaluation was performed according to the following evaluation criteria.
○: 1 kgf / cm ² or more (good adhesion)
×: Less than 1 kgf / cm ² (insufficient adhesion)

<Reworkability evaluation>
-Evaluation method The closed cell foam water-stop sheet with each adhesion layer obtained in Examples and Comparative Examples was cut to a width of 25 mm and a length of 100 mm, and the adhesion layer side was attached to a vehicle coated steel sheet having a thickness of 1 mm. Then, it compressed 50% with the acrylic board of thickness 10mm, and performed the irradiation process for 1000 hours with the sunshine weather meter. After completion of the exposure, it was left at 23 ° C. for 1 hour. After 1 hour, the compression was released, and the peel adhesive strength in the 180 ° direction was measured.
-Evaluation criteria The above measurement was performed 5 times and evaluated according to the following evaluation criteria.
○: When the closed-cell foam sheet did not cohesively break in all 5 times ×: When the closed-cell foam sheet coheses and breaks at a rate of 1 out of 5 times

<Evaluation of extrudability of adhesion layer>
Evaluation method After kneading using a Banbury mixer according to the formulation of the adhesion layer shown in Table 1, an extruded sheet was formed with an extruder under the condition of 80 kg / hr, and the average thickness of the obtained extruded sheet was measured. 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.
Evaluation Criteria Based on the number of measured values where the absolute value is 20% or more of the average thickness, the unevenness was evaluated according to the following evaluation criteria.
○: When the absolute value that is 20% or more of the average thickness is zero ×: When there is one or more absolute value that is 20% or more of the average thickness

上記表中、独立気泡率が７０％未満である場合は、評価結果を「−」と表記した。

In the said table | surface, when the closed cell rate was less than 70%, the evaluation result was described as "-".

  As is clear from the results in Table 1, it can be seen that the closed cell foam water-stop sheet with an adhesive layer of the present invention is excellent in weather resistance. On the other hand, in a comparative example, it turns out that the moldability of a foam is bad in the initial stage.

Claims (11)

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 A closed cell foam water-stop sheet with a close contact layer in which a close contact layer of 0.0 mm and a closed cell foam sheet with a closed cell ratio of 70% or more are adhered,
The closed cell foam sheet is formed by foaming a foamable resin composition containing a thermoplastic resin or a rubber-based resin, a weather resistance agent and a foaming agent,
The content of the weathering agent is 0.1 to 8.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin or rubber-based resin,
The mass ratio [(a2) / (a1)] of the ethylene-propylene-diene rubber (a2) to the butyl rubber (a1) is 0/100 to 93/7,
The content of the petroleum resin-based tackifier (B) with respect to 100 parts by mass of the rubber component (A) is 0.5 to 20 parts by mass,
A closed cell foam waterproofing sheet with an adhesive layer, wherein the 25% compression stress is 10 to 800 kPa.   The closed cell foam-stopped water with an adhesion layer according to claim 1, wherein the weathering agent is carbon black or at least one selected from carbon black, a radical scavenger and a radical chain initiation inhibitor. Sheet.   The closed cell foam water-stop sheet with an adhesive layer according to claim 2, wherein the radical scavenger is a hindered amine light stabilizer.   The closed cell foam water-stop sheet with an adhesion layer according to claim 2, wherein the radical chain initiation inhibitor is an ultraviolet absorber.   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 is obtained by foaming an olefin resin. The closed-cell foam waterproofing sheet with an adhesion layer according to any one of claims 1 to 5, 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 adhesive layer according to any one of claims 1 to 6, wherein the Mooney viscosity ML (1 + 8) at 125 ° C of the butyl rubber (a1) is 20 to 60.   The closed cell foam waterproofing sheet with an adhesion layer according to any one of claims 1 to 7, wherein the closed cell foam sheet has a thickness of 0.05 to 15 mm.   The closed cell foam water-stop sheet with an adhesive layer according to any one of claims 1 to 8, wherein the adhesive layer has a thickness of 0.03 to 1.0 mm.   The closed cell foam waterproofing sheet with an adhesion layer according to any one of claims 1 to 9, wherein the mass ratio [(a2) / (a1)] is from 1/99 to 85/15.   The closed cell foam waterproofing sheet with an adhesion layer according to any one of claims 1 to 10, wherein the closed cell ratio of the closed cell foam sheet is 70% or more.