JPH06248093A - Electron ray crosslinking water-proof sheet and production of water-proof sheet - Google Patents

Abstract

PURPOSE:To obtain the subject sheet composed of a specific rubber composition containing a specific ethylene-propylene-nonconjugated diene rubber as main component, having excellent surface state free from bubbles and exhibiting excellent water-proofness and mechanical properties. CONSTITUTION:This water-proof sheet is composed of a rubber composition having a Mooney viscosity [MU1+4(100 deg.C)] of 30-100 and containing (A) an ethylene-propylene-nonconjugated diene rubber having an iodine value of >=12 and an ethylene content of 50-80wt.% based on the sum of ethylene and propylene, (B) a softening agent (e.g. paraffinic oil) and (C) carbon black. The nonconjugated diene constituting the component A is preferably 5-ethylidene-2- norbornene, etc. The amounts of the components A, B and C are preferably 30-65wt.%, 8-20wt.% and 25-45wt.% based on the rubber composition, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam crosslinkable waterproof sheet and a method for producing a waterproof sheet. More specifically, a manufacturing method of a waterproof sheet that can be suitably used for applications requiring waterproofness and high mechanical properties such as a roofing sheet laid on the roof of a building and a civil engineering sheet laid on the bottom of a pond, and the like. It relates to an electron beam crosslinkable waterproof sheet used.

[0002]

2. Description of the Related Art Conventionally, an ethylene-α-olefin type rubber sheet has been used as a waterproof sheet used in the field of civil engineering and construction mainly because it is required to have weather resistance and heat resistance. Electron beam cross-linking was applied to a sheet-shaped molded product of a rubber composition containing an ethylene-α-olefin-based rubber having an iodine value of 10 or less as a product having improved heat resistance and mechanical properties of the α-olefin-based rubber sheet. A waterproof sheet that has been implemented has been proposed (Japanese Patent Laid-Open No. SHO 61).
-283626 publication).

Although the waterproof sheet has certain heat resistance and mechanical properties, it can be used as a waterproof sheet requiring high mechanical properties such as a civil engineering waterproof sheet. Therefore, further improvement in mechanical properties is desired.

[0004]

Therefore, in view of the above-mentioned prior art, the inventors of the present invention have made earnest studies to obtain a waterproof sheet having more excellent mechanical properties. An ethylene-propylene-non-conjugated diene rubber having an ethylene content and a specific iodine value is used, and the Mooney viscosity (ML1 + 4 (100
It has been found that the mechanical properties of the obtained waterproof sheet are remarkably improved when the temperature is adjusted within a specific range.

[0005]

That is, the present invention comprises a rubber composition containing an ethylene-propylene-non-conjugated diene rubber, a softening agent and carbon black, and the ethylene-propylene-non-conjugated diene rubber is iodine. Price is
12 or more, the ethylene-propylene-non-conjugated diene rubber has an ethylene content of 50 to 80% by weight based on the total amount of ethylene and propylene, and the Mooney viscosity (ML1 + 4 (100 ° C.)) of the rubber composition is An electron beam crosslinkable waterproof sheet, characterized in that it is 30 to 100, and an ethylene-propylene-non-containing sheet having an iodine value of 12 or more and having an ethylene content of 50 to 80% by weight based on the total amount of ethylene and propylene. Containing conjugated diene rubber, softener and carbon black, Mooney viscosity (ML1 + 4
(100 ° C)) is 30 to 100 and a rubber composition is extruded using an extruder to form an electron beam crosslinkable waterproof sheet, and then the electron beam crosslinkable waterproof sheet is irradiated with an irradiation dose of 10 to 30 Mrad.
And irradiating the electron beam crosslinkable waterproof sheet with the electron beam to crosslink the electron beam crosslinking waterproof sheet.

[0006]

OPERATION AND EXAMPLES As described above, the electron beam crosslinkable waterproof sheet of the present invention comprises a rubber composition containing ethylene-propylene-non-conjugated diene rubber, a softening agent and carbon black. -Iodine value of the non-conjugated diene rubber is 12 or more, the ethylene-
In the propylene-non-conjugated diene rubber, the ethylene content is 50 to 80% by weight based on the total amount of ethylene and propylene, and the Mooney viscosity (ML1 + 4) of the rubber composition.
(100 ℃)) is from 30 to 100.

The ethylene-propylene-non-conjugated diene rubber (hereinafter referred to as EPDM) is used as the main component of the rubber composition in the present invention.

The non-conjugated diene contained in the EPDM is a component which is easily cross-linked by irradiation with an electron beam, which will be described later. For example, 5-ethylidene-2-norbornene (hereinafter referred to as ENB) and dicyclopentadiene (hereinafter referred to as D).
CPD), 1,4-hexadiene, 1,7-octadiene, etc., and these can be used alone or in combination of two or more, and among these, the rubber composition obtained is molded. ENB from the point of giving excellent crosslinkability to the electron beam crosslinkable waterproof sheet thus obtained.
And DCPD are preferred.

EPDM has an iodine value of 12 or more, preferably
It is preferably 14 or more. When the iodine value is less than 12, the crosslinking efficiency becomes too small and the modulus of the obtained waterproof sheet becomes small. Note that EP
If the iodine value of DM is too large, the breaking elongation of the waterproof sheet tends to decrease, and EPDM
Considering the economic efficiency of, it is preferably 30 or less, particularly 25 or less.

In EPDM, the ethylene content is preferably 50 to 80% by weight, preferably 55 to 80% by weight, and more preferably 65 to 75% by weight based on the total amount of ethylene and propylene. When the ethylene content is less than 50% by weight, the resulting rubber composition is disintegrated rather than the rate of being crosslinked by electron beam irradiation of the electron beam crosslinkable waterproof sheet obtained by molding. If the ratio becomes larger and the crosslinking efficiency decreases, and if it exceeds 80% by weight, the molecular movement is fixed by crystallization of the rubber composition, and a molded electron beam crosslinkable waterproof sheet is formed. The cross-linking efficiency of is decreased.

In the present invention, it is preferable to use EPDM having a large green strength in order to improve the processability of the waterproof sheet and the physical properties of the waterproof sheet. Examples of the EPDM include those having a Mooney viscosity (ML1 + 4 (100 ° C.)) of 70 to 85, an ethylene content of 65 to 75% by weight, and an iodine value of 15 or more. In order to further improve the extrusion processability of the EPDM, it is preferable to use the EPDM by blending it with EPDM having the following properties.

That is, as EPDM for blending, for example, Mooney viscosity (ML1 + 4 (100 ° C.)) is
30 to 40, an ethylene content of 75 to 80% by weight, and an iodine value of 15 or more.

When the EPDM for blending is used, the green strength is improved, the extrusion speed,
In order to improve the processability during extrusion molding such as the surface condition of the waterproof sheet, the proportion of EPDM in the whole is 10-50.
It is preferably set to wt%.

The Mooney viscosity of EPDM (ML1 +
4 (100 ° C.)) is higher than the above range, oil such as Diana Process PW-90 (trade name, manufactured by Idemitsu Kosan Co., Ltd.) may be added to reduce the Mooney viscosity. preferable.

The EPDM used in the present invention
Examples thereof include Esplen (registered trademark, manufactured by Sumitomo Chemical Co., Ltd.).

The compounding amount of the EPDM is 20% of the rubber composition.
It is preferably -60% by weight, especially 30-55% by weight. When the compounding amount of such a rubber composition is less than the above range, the breaking elongation of the obtained waterproof sheet decreases,
Further, when the waterproof sheet is cross-linked, the sheet tends to be deformed, and if it exceeds the above range, the sheet may be deformed when the waterproof sheet is extruded, or the mechanical properties of the waterproof sheet obtained are insufficient. Tend to do.

The softening agent is a component that imparts flexibility to the obtained waterproof sheet.

Examples of the softening agent include paraffin contents such as Diana Process PW-90, Diana Process PS-90 (trade name, manufactured by Idemitsu Kosan Co., Ltd.), Stanol 66 (trade name, manufactured by Esso Oil Co., Ltd.). Is 50% by weight or more, and naphthene content is 50% by weight.
The above-mentioned naphthenic oils and the like can be mentioned, and these can be used alone or in admixture of two or more.
The content of the aromatic compound in such a softening agent is to sufficiently express the effect of the obtained rubber composition without lowering the crosslinking efficiency of the electron beam crosslinkable waterproof sheet obtained by molding. It is preferably 5% by weight or less, more preferably 1% by weight or less, particularly preferably 0.3% by weight or less, and most preferably the aromatic compound is not contained.

The blending amount of the softening agent is 5 to 5 of the rubber composition.
It is preferably 25% by weight, especially 8 to 20% by weight. When the blending amount of such a softening agent is less than the above range, the processability of the waterproof sheet is lowered, and the flexibility and break elongation of the resulting waterproof sheet tend to be small. If it exceeds, mechanical properties such as hardness, modulus, tensile strength and tear strength of the obtained waterproof sheet tend to be deteriorated.

The carbon black is a component which reinforces the electron beam crosslinkable waterproof sheet obtained by molding the obtained rubber composition and improves its tensile strength, tear strength and breaking elongation.

The carbon black is, for example, ISAF specified in CARBON BLACK Yearbook 1990 No. 40 (Carbon Black Association).
(Intermediate Super Abrasion Furance), HAF
(High Abrasion Furance), MAF (Medium Abrasio
n Furance), FEF (Fast Extruding Furance), G
PF (General Purpose Furance) and the like can be used, and these can be used alone or in combination of two or more kinds. Among these, electron beam cross-linking property obtained by molding the obtained rubber composition Modulus of the waterproof sheet,
HAF, MAF, FEF and GPF can be simultaneously improved in tensile strength and elongation at break.
At least one selected from is preferable. HAF
When used in combination with other carbon blacks, HAF is 50% by weight or less of the total amount of carbon black, especially 30% by weight or less, which maintains the modulus and tensile strength and suppresses the reduction of elongation at break. It is preferable from the point of doing.

The amount of the carbon black compounded is preferably 20 to 60% by weight of the rubber composition, and more preferably 25 to 45% by weight. If the amount of the carbon black compounded is less than the above range, the mechanical properties of the resulting waterproof sheet, particularly the modulus and tear strength, tend to be low, and the extrusion processability of the waterproof sheet tends to be low. Further, if it exceeds the above range, the breaking elongation of the obtained waterproof sheet tends to be small, and the extrusion processability such as the surface skin condition of the waterproof sheet tends to deteriorate.

As described above, the rubber composition used in the present invention contains EPDM, a softening agent and carbon black, and the rubber composition contains a co-crosslinking agent in addition to these. While improving the crosslinking efficiency of the electron beam crosslinkable waterproof sheet obtained by molding the composition,
It can be used as a component not only for carbon-carbon crosslinking but also for forming a crosslinked structure containing the co-crosslinking agent between carbons to improve the flexibility and elongation at break of the electron beam crosslinkable waterproof sheet.

Examples of the co-crosslinking agent include sulfur,
Methacrylic ester compounds such as oil sulfur, ethylene glycol dimethacrylate, isobutylene dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate,
Examples include allyl compounds such as triallyl isocyanurate, diallyl phthalate, and triallyl trimellitate. These can be used alone or in combination of two or more. Among these, electron beam crosslinkable waterproof Sulfur is preferable because it has a great effect of improving the flexibility and elongation at break of the use sheet.

The amount of the co-crosslinking agent added is 0.3 parts by weight or more, especially 1 part by weight, per 100 parts by weight of EPDM, in order to increase the crosslinking efficiency and the flexibility and elongation at break of the obtained waterproof sheet. However, if the amount of the co-crosslinking agent is too large, the modulus tends to be large and the flexibility, elongation at break and heat resistance tend to be small. It is preferably 10 parts by weight or less, especially 2 parts by weight or less.

Further, in the present invention, a white filler such as clay, talc or light calcium carbonate can be compounded in the rubber composition in order to reduce compounding cost. The white filler is preferably blended with the carbon black so that the compounding amount thereof is about 10 to 50% by weight of the rubber composition.

Further, the rubber composition used in the present invention includes, for example, processing aids such as stearic acid, vulcanization aids such as zinc oxide, and poly (2,2,4-trimethyl-1,2).
-Antiaging agents such as dihydroquinoline (224), dehydrating agents such as calcium oxide, dicumyl peroxide, zinc diethyldithiocarbamate (EZ), tetramethylthiuram disulfide (TT), 2-mercaptobenzothiazole (M), etc. Vulcanization accelerators and the like can be used by appropriately adjusting the compounding amount within a range that does not prevent the object of the present invention.

To obtain the above rubber composition, for example, EP
A usual method such as kneading DM, a softening agent, carbon black and, if necessary, other components with a Banbury mixer, a roll, a kneader or the like for about 3 to 5 minutes can be used.

The Mooney viscosity (ML1 + 4 (100 ° C.)) of the rubber composition thus obtained is from 30 to 100, preferably from 30 to 90, in order to improve the processability into a waterproof sheet and the crosslinking efficiency. It is preferably 40 to 80, particularly preferably 50 to 70.

The rubber composition has, for example, a cylinder diameter of
It is put into an extruder such as a roller head extruder of about 90 mm, a T-die extruder, etc., and the temperature in the cylinder of the extruder is set to about 60 to 100 ° C., and the screw rotation speed is 20.
An electron beam crosslinkable waterproof sheet can be obtained by extruding at a production rate of about 1 to 10 m / min at -60 rpm.

The extruder is preferably a roller head extruder because the surface texture of the obtained waterproof sheet is unlikely to deteriorate even when the rubber composition is extruded at a low temperature. Further, the screw type may be either a vent type extruder or a non-vent type extruder, but even when the temperature of the rubber composition reaches a high temperature of more than 130 ° C., for example, A vent type extruder is preferable in order to prevent the generated electron beam crosslinkable waterproof sheet from foaming.

The temperature of the rubber sheet when the rubber composition is extruded from the extruder is 65 to 130 ° C.
It is preferable to adjust the temperature to 90 to 120 ° C.

When the temperature of the rubber sheet when the rubber composition is extruded is less than 65 ° C., the surface condition of the obtained waterproof sheet tends to deteriorate, and the temperature of 130 ° C.
If it exceeds, the scorch will not be generated, but the shape stability of the waterproof sheet tends to be deteriorated due to the decrease in green strength.

The thickness of the electron beam crosslinkable waterproof sheet is not particularly limited, but is usually about 0.5 to 3 mm, particularly 0.8.
It is about 1.5 mm.

The electron beam crosslinkable waterproof sheet thus obtained is irradiated with an electron beam to crosslink the electron beam crosslinkable waterproof sheet, whereby a waterproof sheet can be obtained.

The irradiation dose of the electron beam is 10 to 30 Mrad. When the irradiation dose of such electron beam is less than 10 Mrad, the hardness of the waterproof sheet obtained, the modulus becomes small, and when it exceeds 30 Mrad, the breaking elongation of the obtained waterproof sheet decreases, the hardness, The modulus becomes too large. When the irradiation dose is 20 Mrad or less, the heat generation temperature of the electron beam crosslinkable waterproof sheet when it is irradiated with an electron beam does not exceed 100 ° C, and the green strength may not decrease. It is preferable that foaming due to the water content in the electron beam crosslinkable waterproof sheet is less likely to occur, and the electron beam irradiation equipment is a low electron beam energy type, so that the cost can be sufficiently reduced.

The accelerating voltage when irradiating the electron beam is 0.5 to 3
MeV, especially 0.75-1.5 MeV, is preferred. If the acceleration voltage is less than 0.5 MeV,
When the thickness of the waterproof sheet is 1 mm or more, electron beam transmission tends to be insufficient, and when it exceeds 1.5 MeV, large-scale electron beam irradiation equipment is required.

The device used for irradiating the electron beam is not particularly limited, and a usual electron accelerator can be used.

As described above, the waterproof sheet thus obtained is obtained by extruding a specific rubber composition and irradiating the electron beam crosslinkable waterproof sheet with a specific irradiation dose of an electron beam to obtain the waterproof sheet. Since it is a cross-linked product, it has a smooth surface without foaming and is excellent in waterproof property, and also has excellent mechanical properties regardless of the cross-linking efficiency of the waterproof sheet. .

Next, the electron beam crosslinkable waterproof sheet and the method for producing the waterproof sheet of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Examples 1 to 29 and Comparative Examples 1 to 2 The components shown in Tables 1 and 2 and stearic acid, and the other components for Example 23 were added in the proportions shown in Tables 3 and 4 in a Banbury mixer and A rubber composition was obtained by kneading using a roll.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[0045]

[Table 4]

All EPDMs in Table 1 are esprenes. E673 is an oil-extended product and EPDM10
40 parts by weight of paraffinic oil is contained with respect to 0 parts by weight.

The Mooney viscosities (ML1 + 4 (100 ° C.)) of the obtained rubber compositions are shown in Tables 5-9.

Next, the obtained rubber composition was used as a standard extrusion condition in which the screw was a vent type and the temperature was set as shown below at a roller head extruder (screw diameter 90 mmφ, L / D = 16). Was used to extrude at a screw side head pressure of 40 kg / cm ² and a screw rotation speed of 40 rpm to produce a 1.2 mm-thick electron beam crosslinkable waterproof sheet.

(Set temperature) Screw: 75 ° C. Hopper: 60 ° C. Head: 75 ° C. Cylinder: 65 ° C. Roll (up / down): 60 ° C. Obtained electron beam cross-linkable waterproof sheet, irradiation dose 10 Mrad
(Accelerating voltage: 0.75 MeV, electron beam current: 9.5 mA), 20Mrad
(Accelerating voltage: 0.75 MeV, electron beam current: 9.5 mA) or 30
An electron accelerator was used to irradiate an electron beam with Mrad (accelerating voltage: 0.75 MeV, electron beam current: 9.5 mA) to obtain a waterproof sheet.

The obtained waterproof sheet was cut to prepare a sample (300 mm × 300 mm), and the physical properties of the sample were examined for mechanical properties and rubber hardness according to the following methods. The results are shown in Tables 5-10.

(A) Mechanical properties In accordance with JIS K-6301, 100% tensile stress (hereinafter referred to as M100) (kgf / cm ² ), 300% tensile stress (hereinafter referred to as M300)
(Kgf / cm ² ), tensile strength (TB) (kgf / cm ² ), elongation (EB) (%)
And tear strength (hereinafter referred to as TR-B) (kgf / c
m) was measured.

Regarding the waterproof sheets of Examples 26 to 29, the temperature dependence of TB and EB (TB measurement temperature: 60 ° C., EB measurement temperature: -20 ° C.) was determined according to JIS A-6008.
Heat expansion / contraction amount (mm) (80 ° C for 168 hours) and deterioration treatment (heating treatment (80 ° C for 168 hours), accelerated exposure treatment (250 hours using Sunshine Carbon Arc) or alkali treatment (saturated aqueous solution of calcium hydroxide) At 20 ℃
The tensile performance (TB and EB) after 168 hours) was examined.

As a deterioration property test at the time of elongation, the distance between the marked lines of the sample was stretched to 100% and held by using a holder,
Heat treatment (80 ° C for 168 hours), accelerated exposure treatment (250 hours using a sunshine carbon arc) or ozone treatment (40 ° C for 168 hours) was performed. The sample was observed with an 8 × magnifying glass with the holder attached, but no crack was observed in the sample regardless of which treatment was performed.

(B) Rubber hardness The rubber hardness Hs (JIS-A) was measured according to JIS K-6301.

[0055]

[Table 5]

[0056]

[Table 6]

[0057]

[Table 7]

[0058]

[Table 8]

[0059]

[Table 9]

[0060]

[Table 10]

From the results shown in Tables 5-9, Examples 1--1
It can be seen that the waterproof sheet obtained in 29 has excellent mechanical properties such as 100% tensile stress, 300% tensile stress, tensile strength and elongation.

From the results shown in Table 10, Examples 26 to
The waterproof sheet obtained in 29 further satisfies the requirements for synthetic polymer roofing sheets described in JIS A-6008, such as tear strength, temperature dependence of tensile performance, amount of heat expansion / contraction, and tensile performance after deterioration treatment. It turns out that it does.

Examples 30 to 34 The rubber composition was extruded in the same manner as in Example 26 except that the extrusion conditions of the rubber composition in Example 26 were changed as shown in Table 11 to obtain a rubber composition having a thickness of 1.2 mm. An electron beam crosslinkable waterproof sheet was produced.

Table 11 shows the extruded amount per hour (kg / hour) and the temperature (° C.) of the rubber sheet immediately after extrusion (roll exit).

Further, the state of the surface skin of the obtained electron beam crosslinkable waterproof sheet and the presence or absence of foaming were visually observed,
It evaluated based on the following evaluation criteria. The results are shown in Table 11.

(A) Surface skin condition (evaluation criteria) A: Smooth and good surface condition. B: Some irregularities are seen, and the surface condition is not so good. C: The unevenness is remarkable and the surface condition is poor.

(B) Presence or absence of foaming (evaluation criteria) A: There is no foaming at all. B: Some foaming is observed. C: Many foams are seen.

Then, the obtained electron beam crosslinkable waterproof sheet was irradiated with an electron beam at an irradiation dose of 20 Mrad (accelerating voltage: 3 MeV, electron beam current: 10 mA) in the same manner as in Example 26 to form a waterproof sheet. I got it.

The surface of the obtained waterproof sheet was visually observed and examined. As a result, regardless of the type of screw used (whether or not there was a vent), none of the waterproof sheets had foaming and the surface condition was good.

In Example 26, the extrusion amount per hour (kg / hour) at the time of producing the electron beam crosslinkable waterproof sheet, the temperature (° C.) of the rubber sheet immediately after extrusion (roll exit), and The evaluation results of the surface skin condition of the electron beam crosslinkable waterproof sheet and the presence or absence of foaming are also shown in the table.
Shown in 11.

Examples 35 to 40 In the rubber compositions used in Examples 26 and 30 to 34, calcium oxide (Vesta PP, Inoue Lime Co., Ltd.) was added as a dehydrating agent.
(Manufactured) and extruded the rubber composition in the same manner as in Example 26 and Examples 30 to 34, except that 3 parts by weight of each was blended.
An electron beam crosslinkable waterproof sheet of mm was prepared.

Table 12 shows the extruded amount per hour (kg / hour) and the temperature (° C.) of the rubber sheet immediately after extrusion (roll exit).

Further, the surface skin condition and the presence or absence of foaming of the obtained electron beam crosslinkable waterproof sheet were examined in the same manner as in Examples 30 to 34. The results are shown in Table 12.

Then, the obtained electron beam crosslinkable waterproof sheet was irradiated with an electron beam at an irradiation dose of 20 Mrad (accelerating voltage: 3 MeV, electron beam current: 10 mA) in the same manner as in Example 26 to form a waterproof sheet. I got it.

The surface of the obtained waterproof sheet was visually observed and examined. As a result, similar to the waterproof sheets obtained in Examples 30 to 34, none of the waterproof sheets had foaming and the surface condition was good.

[0076]

[Table 11]

[0077]

[Table 12]

The temperature of the rubber block body when the head was released immediately after the extrusion test in Examples 31 and 37 was 12 respectively.
It was 6 ° C and 131 ° C.

From the results shown in Tables 11 and 12, the electron beam crosslinkable waterproof sheets obtained in Examples 26 and 30-40 did not foam after extrusion and had a good surface condition. It turns out to be a thing.

[0080]

The electron beam crosslinkable waterproof sheet of the present invention comprises:
It is obtained by extrusion molding a specific rubber composition,
Using the electron beam crosslinkable waterproof sheet, the waterproof sheet obtained by the method of the present invention for irradiating the waterproof sheet with a specific irradiation dose of an electron beam to crosslink the surface of the waterproof sheet without foaming. In addition to being smooth and excellent in waterproofness, the mechanical properties are extremely high irrespective of the cross-linking efficiency of the waterproof sheet, and therefore waterproofing and high mechanical properties such as roofing sheets and civil engineering sheets are required. It has an effect that it can be suitably used for a sheet or the like.

Claims (9)

[Claims] 1. A rubber composition containing an ethylene-propylene-non-conjugated diene rubber, a softening agent and carbon black, wherein the ethylene-propylene-non-conjugated diene rubber has an iodine value of 12 or more. In the propylene-non-conjugated diene rubber, the ethylene content is 50 to 80% by weight based on the total amount of ethylene and propylene, and the Mooney viscosity (ML1 + 4 (100
The electron beam crosslinkable waterproof sheet is characterized in that the temperature is 30 to 100). 2. The electron beam crosslinkable waterproof sheet according to claim 1, wherein the ethylene-propylene-nonconjugated diene rubber contains 5-ethylidene-2-norbornene or dicyclopentadiene as the nonconjugated diene. 3. The electron beam crosslinkable waterproof sheet according to claim 1, wherein the softening agent contains an aromatic compound in an amount of 5% by weight or less. 4. The carbon black is HAF, MAF, F.
The electron beam crosslinkable waterproof sheet according to claim 1, 2 or 3, which is at least one selected from EF and GPF. 5. The electron-beam crosslinkable waterproof sheet according to claim 1, 2, 3 or 4, wherein the rubber composition contains a co-crosslinking agent. 6. The electron beam crosslinkable waterproof sheet according to claim 5, wherein the co-crosslinking agent is sulfur, a methacrylic acid ester compound or an allyl compound. 7. An ethylene-propylene-non-conjugated diene rubber having an iodine value of 12 or more and an ethylene content of 50 to 80% by weight based on the total amount of ethylene and propylene.
A rubber composition containing a softening agent and carbon black and having a Mooney viscosity (ML1 + 4 (100 ° C)) of 30 to 100 is extruded using an extruder to form an electron beam crosslinkable waterproof sheet, and then the electron beam is used. Irradiation dose to crosslinkable waterproof sheet
A method for producing a waterproof sheet, comprising irradiating an electron beam of 10 to 30 Mrad to crosslink the electron beam crosslinkable waterproof sheet. 8. A roller head extruder is used as the extruder, and the temperature of the rubber sheet when the rubber composition is extruded is 65
The method for producing a waterproof sheet according to claim 7, wherein the temperature is at about 130 ° C. 9. The method for producing a waterproof sheet according to claim 7, wherein the extruder is a vent type extruder.