PILCURE MBTS
  • Overview
  • Compounding Information
  • Application
Chemical Name 2-2'-Dithiobis(benzothiazole) (MBTS)
Chemical Structure
CAS Reg. No. 120-78-5
Mol. Wt. 332
Product Specification
Parameter Limits Test Method
Product form Powder (OT) -
Color Cream -
Assay (titration ) ,% (min) 94.0 D 5051
Free MBT, % (max) 1.0 D 5044
Melting Point (Initial), °C (min) 170.0 D 1519
Melting Point (Final), °C 172-179 D 1519
Heat Loss, % (max) 0.4 D 4571
Ash, % (max) 0.5 D 4574
Paraffinic Oil (<0.2% PCAH), % 1.0-2.0 NOCIL G-40
Residue on 150 µ, % (max) 0.05 D 5461
Residue on 63 µ, % (max) 0.30 D 5461
Typical Data
Specific gravity at  25°C 1.54 D 1817
Bulk density, kg/m3 350 - 390 NOCIL G-44
Bulk density (Comp), kg/m3 420 - 460 NOCIL G-44
Product Information
Solubility Soluble in chloroform. Slightly soluble in acetone and carbon tetra chloride. Insoluble in water.
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 and BgVV XXI, Categories 1-4.
Toxicity Data
(Please refer to the latest
 Toxicological information.)
 Practically non-harmful. (Oral LD50rat over 5000 mg/kg). Not a skin or eye irritant.
Handling & Personal Protection Ensure good ventilation and avoid creating dusty atmosphere. In case of eye or skin contacts 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 / Paper – Fabric Bag 20 kg
FIBC 500 kg
Storage Life 36 months
Color code Red colored strip.

Pilcure MBTS is a semi-ultra fast accelerator for NR, SBR, BR NBR and other highly unsaturated rubbers. It readily disperses in rubber compounds and acts as a retarder for CR based compounds (depending on type of CR used). Pilcure MBTS is a retarder of cure in rubber compounds accelerated using thiurams (TMTM/TMTD) class accelerators as main accelerator and reduces bloom of thiurams to a great extent.

Pilcure MBTS has a long curing range and is safer than Pilcure MBT at rubber compound processing tempera-tures. Pilcure MBTS is very active above curing temperature of 140°C giving flat curing characteristics to 'polyi-soprene' rubbers (e.g. NR). Pilcure MBTS accelerated compounds exhibit very good tensile and resilience properties when used in combination with other booster accelerators.

Normal dosages of Zinc oxide and Stearic acid are necessary for Pilcure MBTS accelerated cure systems. Pilcure MBTS based cure systems can be activated by using small proportions of DOTG, DPG, TMTM, TMTD, ZDC, etc. to improve the rate and the state of cure with a compromise on scorch, reversion and ageing resis-tance particularly when dithiocarbamate boosted accelerator systems are used.

If required, Pilcure MBTS based cure systems can be retarded using Pilgard PVI or other acid retarders. The response of Pilgard PVI to thiazole class accelerators is somewhat sluggish as compared to its effectiveness with sulphenamide class accelerators. Pilcure MBTS can safely be used to produce non-discoloring and non-staining rubber products and is particularly recommended for rubber to metal bonded products.

Pilcure MBTS shows more retarding effect as compared to Pilcure MBT in IIR based compounds (e.g. butyl tubes/extrusions, etc.) and serves as an oxidizing agent for GMF/dibenzo GMF to form nitroso groups for rapid cross linking of diene rubbers. Pilcure MBTS is also used in the compounds based on halogenated butyl rubbers.

Pilcure MBTS dosages are kept below 3.0 phr level to avoid bloom of thiurams/ dithiocarbamates in EPDM based rubber compounds.

Pilcure MBTS / its combinations with booster accelerators are used in NR, SBR, SBR-NR / BR blends, NBR, IIR, EPDM, and other synthetic rubber based compounds used for the manufacture of motor cycles and scooter tyres, butyl tubes, cycle tyre and tubes, beltings, retreading materials, footwear, hot air cured products and miscellaneous molded and extruded products.

TYPICAL DOSAGES OF PILCURE  MBTS
Product Rubber Accelerator /  Sulphur, phr
MBTS MBT MOR TMTD ZDEC S
Motor Cycle, Scooter
Tyre Treads
NR-
SBR / BR
1.0-1.2** - - 0.1-0.2 - 2.2-2.75*
Auto Tubes IIR
BIIR
0.3-0.4
0.5
- - 1.0
-
0.0-0.2
0.10
1.5
0.5
Cycle Tyre Treads Casing NR-RR
NR-BR
NR
0.8-1.0**
1.0-1.2**
1.0-1.2**
- - 0.1-0.2
0.1-0.2
0.2-0.3
- 2.2-2.5
2.2
2.5-3.0
Conveyor Belt Cover NR
SBR
0.80**
1.2-1.5**
0.2
-
- 0.0-0.15
0.1-0.20
- 2.75*
2.0
Transmission Belts
General Purpose
Heat Resistant
NR
NR
0.3
0.4
- 0.8
-
-
2.0-2.5
- 3.0
0.3
V Belts
Base
Cushion
NR
NR
0.2
0.4
- 0.6**
0.6**
- - 3.0
2.4
Retreading Materials
Cushion-Hot Cure
Cushion-Cold Cure
Vulcanizing Solution
NR
NR
NR
0.2
0.6
1.2
-
0.4
-
  0.7**
-
-
  -
TMTM-0.2
-
- 2.4*
2.4*
4.0*
Footwear
DV Soles
Microcellular Soles
Neolite Soles
NR-SBR
NR-SBR
NR-SBR
  0.7
0.6
0.7
  0.3
-
0.3
- 0.1-0.2
0.1-0.2
0.1-0.2
- 2.2
2.2
2.5
Hot Air Cured Products
Rubberized Fabric and
Rubber Sheeting
NR 0.4 0.4 - - 0.3 2.5
Cables NR
SBR
1.0
1.6
- - TMTM
0.3
- 1.2
1.0
Misc. Molded and
Extruded Products
NR
SBR
NBR
EPDM
0.8-1.0
1.2-1.5
1.2-1.5
3.0
- - 0.0-0.2
0.0-0.2
0.0-0.2
0.75
ZDBC 1.5 2.4
2.2
1.5
0.5
Pilcure MBTS is also used in following compounds / products
  • Chlorobutyl Inner Liner (Bias Tyres) : MBTS-0.75 + Alkyl phenol disulfide-1.2 + ZnO-5.0
  • Bromobutyl Inner Liner (Radials): MBTS-1.25 + ZnO-3.0 + S-0.4
  • Bromobutyl OTR Tubes: MBTS-1.2 + TMTD-1.7 + ZnO-4.0
  • Bromobutyl Tank Lining: MBTS-1.0 + TMTD-0.5 + ZnO-5.0 + S-0.5
Note: 
*  Insoluble Sulphur (100% active content basis)
** Pre Vulcanization Inhibitor may be incorporated at 0.2-0.5 phr levels for desired
scorch safety, ensuring compliance with vulcanizate properties.