HEAT CURED SILICONE RUBBER IOTA HCR 980 U
Description: IOTA HCR 980 U is a silicone master-batch, heat curing after the addition of a vulcanizing agent (chosen according to the processing method).
Applications: IOTA HCR 980 U is recommended for moulding, injection and extrusion of high hardness articles with a good compromise of mechanical properties.
Special properties:
Slight refreshening after prolonged storage
Easy to process
Without post-cure or slight post-cure
Good heat stability, up to 200°C, or even 250°C with additive. Wide possibilities for blending with other master batch
Characteristics:
Type (in accordance with GB/T 5576-1997) ………………… VMQ
Density at 25°C, g/cm3, approx………………………………… 1.18
Natural color……………………………………………………………… translucent
Properties after working:
(1) After addition of 1.25% 2,4-dichloro-benzoyl peroxide(at 50%), and vulcanization for 8min
at 115°C;
(2) After addition of 1.0% 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane at 45%, and vulcanization for 10 minutes at 170°C.
1. Mechanical properties
1.1 Properties without post-cure (1) (2)
Shore A hardness, approx………………………………… 75 78
Tensile strength, MPa, approx………………………… 8.9 8.9
Elongation at break, %, approx…………………… …. 280 270
Modulus at 100% elongation, MPa, approx……….3.4 3.9
Tear strength, kN/m, approx……………………………. 17 19
Compression set (22h/177°C/25%), % approx…… 63 28
Rebound resilience, %, approx………………………… 61 64
Linear shrinkage, % approx……………………………… 1.5 3
1.2 Properties after post-cure for 4 hours at 200°C
Shore A hardness, approx………………………………… 78 81
Tensile strength, MPa, approx………………………….. 8.0 8,2
Elongation at break, %, approx………………………… 230 230
Modulus at 100% elongation, MPa, approx……… 3.8 4.4
Tear strength, kN/m, approx………………………….… 16 18
Compression set (22h/177 °C /25%), %, approx… 34 20
Rebound resilience, %, approx………………………… 60 66
Linear shrinkage, % approx……………………………… 3 4.5
2. Heat stability
2.1 Properties after ageing 7 days at 177°C
Shore A hardness, approx………………………………… 79 83
Tensile strength, MPa, approx………………………… 10 8.2
Elongation at break, %, approx………………………. 325 200
Tear strength, kN/m, approx…………………….……. 16 17
2.2 Properties after ageing 10 days at 177°C
Shore A hardness, approx…………………………….… 81 86
Tensile strength, MPa, approx…………………………… 7.1 7
Elongation at break, %, approx…………………………. 150 100
Tear strength, kN/m, approx…………………………….. 13 14
3. Heat resistance with the addition of 0.4 parts of additive 744
3.1 Properties after ageing 10 days at 200°C
Shore A hardness, approx…………………………….… 76 82
Tensile strength, MPa, approx…………………………… 7.5 7.2
Elongation at break, %, approx…………………………. 235 195
Tear strength, kN/m, approx…………………………….. 15 16
3.2 Properties after ageing 3 days at 225°C
Shore A hardness, approx…………………………….… 76 81
Tensile strength, MPa, approx…………………………… 7.1 7.4
Elongation at break, %, approx…………………………. 235 210
Tear strength, kN/m, approx…………………………….. 14 16
3.3 Properties after ageing 7 days at 225°C
Shore A hardness, approx…………………………….… 77 82
Tensile strength, MPa, approx…………………………… 6.6 6.7
Elongation at break, %, approx…………………………. 210 175
Tear strength, kN/m, approx…………………………….. 13 15
3.4 Properties after ageing 3 days at 250°C
Shore A hardness, approx…………………………..……… 76 83
Tensile strength, MPa, approx…………………………... 5.5 5.5
Elongation at break, %, approx…………………………. 160 110
Tear strength, kN/m, approx………………………………. 11 12
4. Electrical properties
Dielectric strength (on 2 mm thick slabs), kV/mm, approx… 23
Breakdown voltage, kV……………………………………………………… 44
Dielectric constant at 1 MHz, approx………………………………… 2.9
Dissipation factor at 1 MHz, approx…………………………………… 3.0×10-3
Volume resistivity, Ohm.cm, approx…………………………………… 1.2×1015
Packaging: IOTA HCR 980 U is delivered in 20 kg carton boxes.
Storage and shelf life:
IOTAHCR 980 U may be stored in its original unopened packaging at a temperature below 40°C for up to 18 months from the date of manufacture marked clearly on the packaging.
Past this date, IOTA no longer guarantee that the product meets the sales specifications.
