PILCURE TMT
  • Overview
  • Compounding Information
  • Application

Chemical Name

Tetramethyl thiuram disulfide (TMTD)

Chemical Structure

CAS Reg. No.

137-26-8

Mol. Wt.

240

Product Specification

Parameter

Limits

Test Method

Product form

Powder (OT)

-

Color

Off white-Cream

-

Assay  ,% (min)

96.0

NOCIL 02-3-318

Melting Point, initial, °C

142.0

D 1519

Melting point, final, °C (min)

147.0

D 1519

Heat Loss, % (max)

0.5

D 4571

Ash, % (max)

0.3

D 4574

Paraffinic Oil (<0.2% PCAH), %

1.0-2.0

NOCIL G-40

Residue on 150 µm sieve, % (max)

0.0

D 5461

Residue on 63 µm sieve, % (max)

0.3

D 5461

Typical Data

Specific gravity at  25°C

1.43

D 1817

Bulk density , kg/m3

340 – 380

NOCIL G-44

Bulk density (Comp), kg/m3

410 - 440

NOCIL G-44

Product Information

Solubility

Soluble in methyl chloride,  partly soluble in alcohol . Insoluble in water.

Classification

 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 & ‘Sonderkategorie’.

Toxicity Data
(Please refer to the latest
Toxicological information.)

Harmful by mouth. (Oral LD50rat 780-1300 mg/kg).  A substance of moderate toxicity, slight eye & skin irritant and skin sensitizer. Can cause alcohol intolerance by inhalation of dust or absorption through skin.

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 and seek medical advice urgently if swallowed.

Storage

Always store in a cool (below 35ºC) & dry place in single stack pallets away from direct sun light or any other heat source to avoid grit formation.

Packaging

Paper-Fabric  Bag

20 kg

FIBC

Storage Life

24 months

Color code

Orange colored strip.

Pilcure TMT is an ultra fast accelerator for NR, SBR, BR, NBR and other highly unsaturated rubbers and most preferred primary accelerator for sulphur cured low unsaturation content rubbers like Butyl rubber (IIR) and EPDM.

Pilcure TMT is widely used as a secondary accelerator with thiazole / sulphenamide class accelerators to achieve faster curing rate and higher cross link density with a compromise on scorch safety. Pilcure TMT contains approx. 13% available sulphur for cross linking and hence, can be used in low sulphur / sulphur less EV cures of diene rubbers. Pilcure TMT does not liberate ‘free sulphur’ during sulphur less cures and the vulcanizates exhibit excellent heat and compression set resistance.

Pilcure TMT is very active at temperatures above 120°C and particularly in NR based compounds, when used alone, exhibits very short scorch time, faster cure rates and marching modulus with development of high cross link density at normal to high sulphur levels. Decrease in sulphur levels improves scorch safety and helps to control the cure rate as well as cross link density.                

In SBR based compounds, Pilcure TMT exhibits faster scorch and cure characteristics with relatively broad curing range and flat plateau effect. Semi-EV, EV (low sulphur / sulphur less) cure   systems based on Pilcure TMT are often used in NBR based compounds to achieve stringent requirements of heat and oil resistant vulcanizates with lower compression set values. In case of polychloroprene and other halogenated rubber compounds, Pilcure TMT acts as a retarder.

Normal dosages of Zinc oxide and Stearic acid are necessary for Pilcure TMT accelerated cure systems and small proportions of aldehyde amine, DPG, DOTG, ZDC, etc.  can further activate the cure rate. However; often retardation of Pilcure TMT based cure systems is desired and the same can be achieved by using sulphenamide or thiazole class accelerators as the conventional  acid retarders are not effective. Sulphenamide and thiazole accelerators control the ‘scorching’ and ‘blooming’ tendency for Pilcure TMT based Semi-EV/EV cures without significantly affecting the cross link  density and offering practical cure cycles.

As a secondary accelerator Pilcure TMT is very effective with thiazole and sulfenamide accelerators for achieving faster cure rates and good scorch resistance and the vulcanizates exhibit lower heat build-up as compared to DPG / DOTG activated sulphenamide cures.

 In case of rubber to metal bonded products along with thiazoles Pilcure TMT is the preferred secondary accelerator as compared to other basic accelerators like DPG, ZDC etc.

Pilcure TMT and / or Pilcure ZDC are  non-staining and  non-discoloring and also do not impart any taste to the vulcanizates and hence often preferred for the manufacture of rubber products intended for repeated contact with food/drugs. (it may be noted that the FDA rules and regulations are subject to change and seeking clarification from relevant authorities is recommended before commercial manufacture of rubber products).

Pilcure TMT as a primary accelerator and as a secondary accelerator in combination with sulfonamide / thiazoles, etc. is extensively used in NR, SBR, NR-SBR/BR blends, NBR,IIR, EPDM and other synthetic rubber based compounds for the manufacture of auto tyres and tubes, cycle tyres and tubes, conveyor / transmission beltings, retreading materials, footwear, hot air cured products and miscellaneous molded and extruded rubber products.
 

TYPICAL DOSAGES:

Typical dosages of Pilcure TMT based cure systems are given below

TYPICAL DOSAGES OF PILCURE  TMT

Product

Rubber

Accelerator /  Sulphur, phr

TMTD

MBTS

CBS

ZDC

ZDBC

DPG

S

Auto Tubes

Butyl
NR

1.0-2.0
2.0-2.5

0.3-0.4
1.0-1.3

-
-

0.2
-

-
-

-
-

1.5-2.0
0.5

OTR Tubes

Bromo- Butyl

1.7

1.2

-

-

-

-

ZnO-4.0

Cycle Tyre :
Treads

Casing

 

NR
NR-BR
NR
NR

 

0.1-0.2
0.2
0.2-0.3
0.05

 

-
-
1.0
0.7

 

0.8-1.0
1.0-1.2
-
-

 

-
-
-
-

 

-
-
-
-

 

-
-
-
0.25

 

2.4
1.8-2.0
2.5
2.5

Cycle Tubes

NR

0.1-0.2

-

0.8-1.0

-

-

-

1.5-1.7

Molded& Extruded Goods
Conventional Cure

 

 

 

 

 

 

Semi EV Cure

 

EV Cure

 

NR
NR
NR

SBR
SBR

NBR
NBR

EPDM
EPDM
EPDM

NR
SBR
NBR

NR
SBR
NBR

 

0.5-0.7
0.1-0.2
0.1-0.2

0.1-0.2
0.1-0.2

0.2-0.4
0.2-0.4

1.5
0.8
0.8

0.5
0.5
1.5

2.5-3.0
3.0-4.0
3.0-4.5

 

-
0.7-1.0
-

1.2-1.4
-

1.0-1.2
-

0.5
2.0
1.5

-
-
-

-
-
-

 

0.3
-
0.7-1.0

-
1.0-1.2

-
1.2-1.4

-
-
-

1.5
2.0
1.0-1.2

1.0-1.5
1.0-1.2
1.0-1.2

 

-
-
-

-
-

-
-

-
0.8
-

-
-
-

-
-
-

 

-
-
-

-
-

-
-

-
1.0
2.5

-
-
-

-
-
-

 

-
-
-

-
-

-
-

-
-
-

-
-
-

-
-
-

 

2.0-2.5
2.0-2.5
2.0-2.5

2.0-2.2
2.0-2.2

1.5
1.5

1.5
2.0
2.0

1.4
0.75
1.0

0-0.3
0-0.3
0-0.3

Fast Curing Ebonite

NR/ SBR
/ NBR

3.0-4.0

-

-

-

-

-

20-40

Food Contact Products

NR/ SBR
/ NBR

0.5-0.7

-

-

0.2-0.4

-

-

1.5-2.0