Pilcure ZMBT is a semi-ultra fast accelerator for NR, SBR, NBR, BR and other diene rubbers.
The critical cure temperature of Pilcure ZMBT is approx. 120°C and dry rubber / latex based compounds are vulcanized quickly at 125°C.The state of cure developed by Pilcure ZMBT is slightly lower than Pilcure MBT; however, scorch safety is much higher and hence can be used in place of MBT for scorch control.
Pilcure ZMBT is mainly used in latex compounding along with Pilcure ZDC/ Pilcure ZDBC to improve the state of cure. Pilcure ZMBT improves the ageing characteristics of NR latex based vulcanizates and does not affect the stability of NR latex based compounds.
Pilcure ZMBT readily disperses in water in the presence of commonly used dispersing agents (e.g. sodium salt of polymerized alkyl naphthalene sulfonic acid) and is usually used as 50% dispersion in water for latex compounding applications. Pilcure ZMBT has a sensitizing effect on NR latex due to its thixotropic nature and this property favors NR latex foaming in the production of latex foam products. Where this property is not desired, the thixotropic effect can be overcome by stirring.
When used for compounding of latex foam manufacture, Pilcure ZMBT and Pilcure ZDC combinations give latex foam products with high compression modulus vulcanizable at 110°C. One can reduce the dosage of Zinc oxide in latex foam compounds for optimization / adjustments in gelation periods.
Normal dosages of Zinc oxide and Stearic acid are necessary when Pilcure ZMBT is used for dry rubber compounding; however, dosage of Zinc oxide can be reduced considerably for certain specific applications.
Pilcure ZMBT can be activated by small dosages of basic accelerators such as TMTM, TMTD, DPG, ZDC etc. or even by other basic compounding materials. If required; common acidic retarders or Pilgard PVI can be used to delay the on-set of cure.
High accelerator-low sulphur cure systems based on Pilcure ZMBT offer excellent heat resistance to NR rubber vulcanizates. Pilcure ZMBT also acts as an effective retarder for sulphur cure systems based on Thiurams and dithiocarbamates as primary accelerators.
Recommended method for preparation of 50% dispersion of Pilcure ZMBT for latex compounding is given below:
Ingredients |
Dry |
Wet |
Pilcure ZMBT, pbw |
50 |
50 |
10% Dispersing Agent, pbw |
1 |
10 |
10% KOH Solution, pbw |
0.5 |
5 |
China clay, pbw |
0.5 |
0.5 |
Water, pbw |
- |
34.5 |
TOTAL |
52.0 |
100 |
Note: Dispersing Agent: Sodium salt of polymerized alkyl naphthalene sulfonic acid. |
METHOD:
Charge Pilcure ZMBT, dispersing agent and part quantity of water and grind to paste. Add China clay, balance quantity of water, 10% KOH solution and ball mill for 24 to 48 hr depending on the requirements of the rubber product to be manufactured.
Pilcure ZMBT (in combination with Pilcure ZDC) is mainly used in NR/Synthetic Rubber latex compounding for the manufacture of latex foam, coir foam, carpet backing, latex thread, battery separators and other latex based products. Pilcure ZMBT in combination with booster accelerators is used in dry rubber based compounds for the manufacture of footwear soles and heels, hot air cured footwear and other molded and extruded goods.
TYPICAL DOSAGES OF PILCURE ZMBT |
Product |
Rubber |
Accelerator / Sulphur, phr |
ZMBT |
ZDEC |
ZDBC |
TMTD |
DPG |
S |
LATEX PRODUCTS |
Latex Foam
Latex Coir Mattresses
Foamed carpet backing
a. Low Density
b. High Density |
NR Latex
NR Latex
Latex
NR-SBR
NR-SBR |
1.0
1.0 1.0
1.5 |
1.0
1.0 0.5
1.5 |
-
- -
- |
-
- -
- |
0.6
- -
- |
2.0
2.0 1.5
2.5 |
Latex Thread
- Translucent
- Heat Resistant
- General Purpose
|
NR Latex
NR Latex
NR Latex |
1.5
1.5
1.0 |
-
-
0.6 |
0.25
0.50
- |
-
DPTT-2.0
- |
-
-
- |
1.75
-
1.75 |
Battery Separators |
NR Latex |
1.0 |
1.0 |
- |
- |
- |
40.0 |
Household Gloves |
NR Latex |
1.0 |
0.2 |
- |
- |
1.2 |
2.5 |
Condoms |
NR Latex |
0.75 |
- |
0.75 |
- |
- |
0.75 |
Latex Cast Products |
NR Latex |
0.70 |
0.70 |
- |
- |
- |
1.40 |
DRY RUBBER PRODUCTS |
Cushion Gum (Hot Cure) |
NR |
1.0 |
- |
- |
- |
0.5 |
Ins.S-2.8 |
Rubber Lining |
NR-SBR |
2.5 |
1.0 |
- |
- |
- |
2.5 |
Molded Goods
General Purpose
Heat Resistant
High Heat Resistant
Translucent Products
Extruded Products |
NR/SBR
NR/SBR
NR/SBR
NR/IR
NR |
0.8-1.2
1.5
3.0
0.6
1.2 |
-
-
-
-
- |
-
-
-
0.2
- |
0.0-0.15
0.5
0.1
-
- |
-
-
-
-
0.3-0.4 |
1.6-2.2
0.5
1.0
1.0-1.5
1.8-2.2 |
Cables |
NR-SBR |
3.0-3.5 |
- |
- |
0.15 |
- |
1.2 |
Note:
Pre Vulcanization Inhibitor may be incorporated at 0.2-0.4 phr levels for desired
scorch safety, ensuring compliance with vulcanizate properties. |