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About rubber

We offer a wide variety of high quality rubber materials, sheets and formed products based on the long-established rubber process technologies of Denka Elastlution and the research and technologies of Denka Co., Ltd.

Natural rubber (NR)

Polymerized isoprenehas a small amount, 7 to 8%, of non-rubber content.
Because it is a natural product, it varies in quality. However, it makes low-priced products with well-balanced physical properties possible.Its weather resistance may be poorer than synthetic rubber.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength （MPa） Elongation （％） Change after aging at 70 °C for 70 hours Permanent compression set at 70 °C for 22 hours(%)
Hardness
Hs A		 Tensile strength (%) Elongation (％)
50 4.4 350 ＋10 −10 −35 45
60 4.4 350 ＋10 −10 −35 45
65 2.5 250 ＋10 −10 −35 50
70 3.9 250 ＋10 −10 −35 45
80 3.4 100 ＋10 −10 −35 45

Chloroprene rubber (CR)

Chloroprene rubber (CR) is a chloroprene polymer It is a type of synthetic rubber that is highly flame-retardant, weather resistant and water resistant.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength (MPa) Elongation (%) Change after aging at 70 °C for 70 hours Permanent compression set at 70 °C for 22 hours) (%)
Hardness
Hs A		 Tensile strength (%) Elongation (％)
40 3.9 400 ＋18 ＋12 −40 38
50 9.8 450 ＋10 −12 −25 27
60 10.8 400 ＋12 ＋12 −23 28
65 5.9 500 ＋20 −30 −35 38
70 11.8 300 ＋12 −1 −40 25
80 12.7 200 ＋12 −3 −25 30

Ethylene propyrene rubber (EPDM)

Ethylene propylene rubber (EPDM) is a terpolymer created by adding an amount of diene as a third component to ethylene (CH2=CH2) and propyleneIts greatest feature is its excellent weather resistance.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength (MPa) Elongation (%) Change after aging at 70 °C for 70 hours
Hardness
Hs A		 Tensile strength (%) Elongation (％)
50 10.8 500 ＋14 −10 −40
60 10.8 350 ＋15 −5 −35
65 6.9 350 ＋15 −11 −42
70 10.8 300 ＋13 −5 −40
80 10.8 300 ＋10 −12 −40

Styrene-butadiene rubber (SBR)

Styrene-butadiene rubber (SBR) is a copolymer of styrene (C6H5 -CH=CH2) and butadiene (CH2=CH-CH=CH2). Its properties are similar to natural rubber.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength (MPa) Elongation (%) Change after aging at 70 °C for 70 hours Permanent compression set at 70 °C for 22 hours (%)
Hardness
Hs A		 Tensile strength (%) Elongation (％)
60 7.8 350 ＋15 −15 −50 30
60 9.8 400 ＋15 −15 −40 30

Nitrile rubber (NBR)

Nitrile rubber (NBR) is a copolymer of butadiene (CH2=CH-CH=CH2) and acrylonitrile (CH2=CH-CN). Its greatest feature is its excellent oil resistance.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength (MPa) Elongation (%) Change after aging at 70 °C for 70 hours Permanent compression set at 70 °C for 22 hours (%)
Hardness
Hs A		 Tensile strength (%) Elongation (％)
50 8.8 500 ＋12 −7 −19 62
60 9.8 450 ＋12 ＋14 −34 64
70 9.8 400 ＋12 ＋7 −35 66
80 12.7 350 ＋10 ＋10 −50 56

Isobutylene-isoprene rubber (IIR)

Isobutylene-isoprene rubber (IIR) is a copolymer of isobutylene ((CH3)2C=CH2) and a small amount of isoprene (CH2=C(CH3)-CH=CH2). Its characteristics include limited gas penetration, excellent airtightness and very low impact resilience.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength (MPa) Elongation (%) Change after aging at 70 °C for 70 hours
Hardness
Hs A		 Tensile strength (%) Elongation (％)
60 10.8 370 ＋8 ＋2 −31
65 9.8 360 ＋12 ＋9 −37
70 10.8 300 ＋10 ＋3 −42
65 7.4 450 ＋4 −10 −20
70 7.4 500 ＋3 −10 −30

Silicone rubber (Q)

Silicone rubber (Q) is a methyl vinyl silicone polymer withbonds. It exhibits excellent heat and cold resistance.

●Typical physical properties of sheets

Hardness
Hs A		 Tensile strength (MPa) Elongation (%) Change after aging at 70 °C for 70 hours Permanent compression set at 70 °C for 22 hours (%)
Hardness
Hs A		 Tensile strength (%) Elongation (％)
40 4.9 300 −4 −15 −25 38
50 4.9 200 −3 −15 −25 20
60 5.9 150 −2 −15 −35 23
70 5.9 120 −3 −20 −40 24
80 5.9 120 −2 −15 −30 29

Chemical resistance of various rubbers

  NR IR BR SBR IIR EPDM CR CSM NBR Q
Gasoline and diesel oil × × × × × × ◯ △ ◎ △～×
Benzene and toluene × × × × △ △ × △～× △～× △～×
Trichloroethylene × × × × × × × × × ◯～×
Alcohol ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎
MEK Ethyl acetate ◯～△ ◯～△ ◯～△ ◯～△ ◎ ◎ ◯～△ △ × ◯
Strong acid △ △ △ △ ◎ ◯ ◯ ◎ ◯ △
Weak acid ◯ ◯ ◯ ◯ ◎ ◎ ◎ ◎ ◯ ◯
Strong alkali ◯ ◯ ◯ ◯ ◎ ◎ ◎ ◎ ◯ ◎
Weak alkali ◯ ◯ ◯ ◯ ◎ ◎ ◎ ◎ ◯ ◎

◎ = Excellent, ◯ = Good, △ = Applicable, × = Not applicable