PILCURE ZMBT
  • Overview
  • Compounding Information
  • Application
Chemical Name Zinc-2-mercaptobenzothiazole (ZMBT)
Chemical Structure
CAS Reg. No. 155-04-4
Mol. Wt. 398
Product Specification
Parameter Limits Test Method
Product form Powder (WT) -
Color White to Cream  yellow -
Free MBT-Grade 1, % 0.0 - 2.0 NOCIL  02-3-304
Free MBT-Grade 2, % 4.0 - 6.0 NOCIL 02-3-304
Free MBT-Grade 3, % 13.5±2.5 NOCIL 02-3-304
Zn Content-Grade 1, % 19.0-22.0 NOCIL 02-3-323
Zn Content-Grade 2, % 17.5-20.5 NOCIL  02-3-323
Zn Content-Grade 3, % 16.0-19.0 NOCIL 02-3-323
Heat Loss, % (max) 0.5 D 4571
Residue on 150 µ, % (max) Nil D 5461
Residue on 63 µ, % (max) 0.50 D 5461
Typical Data
Specific gravity at 25°C 1.70-1.77 D 1817
Bulk density, kg/m3 490 - 530 NOCIL G-44
Bulk density (Comp), kg/m3 620 - 660 NOCIL G-44
Product Information
Solubility Soluble in dilute alkali. Slightly soluble in alcohol, benzene & chlorinated solvents. Insoluble in water and gasoline.
Classification Semi ultra fast accelerator.
Discoloration & Staining Non-discoloring and Non-staining.
FDA Approval Status Regulated for use in articles in contact with food under FDA 21 CFR 177.2600, 175.105, 178.3120 and BgVV XXI, Categories 3-4.
Toxicity Data
(Please refer to the latest
 Toxicological information.)
Non-harmful. (Oral LD50rat over 5000 mg/kg). Slight skin and eye irritant.
Handling & Personal Protection Ensure good ventilation and avoid creating dusty atmosphere. In case of eye or skin contact, wash out with clean water for 5 to 10 minutes.
Storage Store at room temperature in a cool, dry and well ventilated place. Avoid exposure of the packaged material / product to direct sunlight & heat.
Packaging
Paper-Fabric Bag 20 kg
FIBC 500 kg
Storage Life 24 months
Color code Yellow colored strip.

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
  1. Translucent
  2. Heat Resistant
  3. 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.