HCR 1970 U is a silicone master-batch, heat curing after the addition of a vulcanizing agent (chosen according to the processing method).

Details

HEAT CURED SILICONE RUBBER  HCR 1970 U

Description:  HCR 1970 U is a silicone master-batch, heat curing after the addition of a vulcanizing agent (chosen according to the processing method).

Applications:  HCR 1970 U is recommended for moulding, has good compromise of mechanical properties.

Special properties:
Good mechanical properties;

Good appearance, anti-yellowing;

Good heat stability, up to 200°C;

Not easy to structured after long-term storage;

No post curing or slight post curing;
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…………………………………………………  1.22

Natural color…………………………………………………………………  translucent

Properties after working：

1) After addition of 1.25% Di(2,4-dichlorobenzoyl) peroxide (at 50%), and vulcanization for 8 minutes at 115℃

2) After addition of 1.1% 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (at 45%), and vulcanization for 5 minutes at 175℃

1.Mechanical property:

1.1 Properties without post-cure                                            1）    2）

Shore A hardness, approx……………………………………………………… 69     69

Tensile strength, MPa, approx………………………………………………… 7.3    8.4
Elongation at break, %, approx………………………………………………. 372   399
Modulus at 100% elongation, MPa, approx…………………………….   2.64   2.68
Tear strength, (ASTM D 624 Die B) kN/m, approx…………………   19     19
Rebound resilience, %, approx……………………………………………    43    42

Linear shrinkage, %, approx………………………………………………… 1.5   3.2

1.2Properties after post-cure for 4 hours at 200°C

Shore A hardness, approx…………………………………………………   71    73
Tensile strength, MPa, approx…………………………………………..    8.2   8.8
Elongation at break, %, approx…………………………………………    326   358
Modulus at 100% elongation, MPa, approx…………………………     3.00  2.93
Tear strength (ASTM D 624 Die B)，kN/m, approx……………    16    17
Compression set , (22 h/177℃/25%) %, approx………………       -     27

Rebound resilience, %, approx…………………………………………    40    42

Linear shrinkage, %, approx………………………………………………   2.1   3.8

2. Thermal stability

Properties after post-cure for 3 days at 225°C
Shore A hardness, approx…………………………………………………   74    76
Tensile strength, MPa, approx…………………………………………..   6.4   6.1
Elongation at break, %, approx……………………………………………  11   204

Packaging:  HCR 1970 U is delivered in 20 kg carton boxes.
Storage and shelf life:  HCR 1970 U may be stored in its original unopened packaging at a temperature below 40°C for up to 12 months from the date of manufacture marked clearly on the packaging.

Past this date,  no longer guarantees that the product meets the sales specifications.