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.