PILCURE MOR
  • Overview
  • Compounding Information
  • Application

Chemical Name

2-(4-Morpholinothio) benzothiazole (MBS)

Chemical Structure

CAS Reg. No.

102-77-2

Mol. Wt.

252

Product Specification

Parameter

Limits

Test Method

Product form

Pellets (2mm)

-

Color

Off white to light buff

-

Assay (titration ) ,% (min)

97.0

D 4936

Melting point , final , °C

82-88

D 1519

Heat Loss, % (max)

0.3

D 4571

Ash, % (max)

0.3

D 4574

Methanol Insolubles, % (max)

0.3

D 4934

Free Amine, % (max)

0.3

D 4936

Typical Data

Specific gravity at  25°C

1.36

D 1817

Bulk density , kg/m3

540 - 580

NOCIL G-44

Bulk density (Comp), kg/m3

550 -590

NOCIL G-44

Product Information                       

Solubility

Soluble in acetone, benzene & chloroform. Partially soluble methyl alcohol. Insoluble in water.

Classification

Fast – Delayed action accelerator.

Discoloration & Staining

Non staining. At higher dosages slight discoloration.

FDA Approval Status

Regulated for use in articles in contact with food under FDA 21 CFR 177.2600, and BgVV  XXI, Category 4.

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

Practically non-harmful. (Oral LD 50 rat over 5000 mg/kg). Not a skin or eye irritant. To minimize the possibility of nitrosamines generation; morpholine   based chemicals are avoided with nitrosating agents.

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

Always store in a cool (below 30ºC) & dry place in single stack pallets away from direct sun light or any other heat source to avoid compaction. Avoid exposure to acids, acidic materials / atmosphere & high humidity.

Packaging

Paper –Fabric Bag

20 kg

FIBC

500 kg

Storage Life

12 months when stored as stated above.

Color code

Dark Yellow colored strip

Pilcure MOR is a delayed action sulphenamide accelerator for NR, NR-BR blends, NR-SBR blends and other highly unsaturated synthetic rubber based compounds reinforced with fine particle size furnace blacks prone to excessive heat generation during processing operations. Pilcure MOR pellets exhibit good storage stability and disperse easily in rubber compounds due to comparatively lower melting range of Pilcure MOR.

Normal dosages of Zinc oxide and Stearic acid are necessary for cure activation of compounds based on Pilcure MOR. Pilcure MOR is used at 0.5-1.0 phr dosage for conventional cure systems, at 1.5 to 2.0 phr dosage for Semi-EV cures and at 3.0 and above for low sulphur EV cures.

Pilcure MOR is very active above 140°C and offers longer scorch delay; particularly during high temperature processing operations (e.g.extrusion/ calendaring, etc.) as compared to Pilcure CBS or Pilcure NS for tyre treads or similar high performance rubber compounds.    

The rubber compounds based on Pilcure MOR exhibit excellent shelf life and retention of cure activity on prolonged storage as compared to other sulphenamide accelerators.  At curing temperatures Pilcure MOR exhibits delayed on- set of cure along with faster cure rate and a very good plateau effect. The crosslink density obtained by using Pilcure MOR is approximately 6-8% lower than Pilcure CBS and 12 to 15% lower than Pilcure NS when compared at equal dosages of  these sulphenamide class accelerators. Progressive increase in Pilcure MOR dosage, like other sulphenamide accelerators, shows improvements in scorch delay, cure rate and state of cure. The vulcanizates based on Pilcure MOR exhibit higher modulus, excellent elastic properties under dynamic conditions and lower heat buildup  under dynamic stress. Semi-EV cure systems based on Pilcure MOR offer improved heat and ageing resistance.

Pilcure MOR is usually incorporated in the rubber compounds at the end of the mixing cycle. In case Pilcure MOR is to be added at a  later stage it is sufficient to ensure  that the rubber compound is warmed to 80-85°C for achieving excellent dispersion and dissolution of Pilcure MOR.

Pilcure MOR is a sulphenamide accelerator based on secondary amine (Morpholine) and hence is extremely sensitive to booster accelerators like DPG, DOTG, TMTM, and ZDC as as well as pre vulcanization inhibitor Pilgard PVI (CTP). Thus, when booster accelerators are required for further activation or Pilgard PVI is required for further scorch delay; very small dosages can produce desired response. Pilcure   MBT (used in small dosages) also activates the rate of cure; however, thiuram accelerators TMTM / TMTD and dithiocarbamates are generally preferred as booster accelerators for achieving desired vulcanizate properties.

Like other sulphenamide accelerators, Pilcure MOR also decomposes rapidly in the presence of hot steam and can be used for the manufacture of open steam cured products requiring faster onset of cure; however, similar advantage is not offered for hot air cured products in the absence of strong booster accelerators. Pilcure MOR is an excellent accelerator for EPDM cures where long scorch delay and faster cure rate is desired. A cure system of Pilcure MOR 3.5 phr and Sulphur 1.5 phr may be used for curing products like dock fenders where long scorch delay, excellent stock shelf life and faster cures are needed.

Pilcure MOR is the most effective retarder for thiuram based EV-cures. Incorporation of Pilcure MOR reduces the blooming tendency of the thiuram cured vulcanizates and contributes to improvements in the state cure if sulphur is incorporated at small dosage.

Pilcure MOR based vulcanizates have a typical amine  odor & bitter taste and hence Pilcure MOR is generally avoided for the manufacture of rubber goods intended for repeated contact with food / drugs.

Pilcure MOR alone or in combination with small quantities of booster accelerator is widely used in NR, SBR, NR-BR/SBR blends, NBR and other synthetic rubber based compounds  used for the manufacture of auto tyres, tyre retreading materials, conveyor and power transmission beltings, rubber goods with thick cross sections, intricately shaped rubber goods, rubber footwear, injection molded goods, cables and other miscellaneous molded and extruded rubber products.

Typical dosage of Pilcure MOR based accelerator systems are given below:

Product

Rubber

Accelerators / Sulphur, phr.

MBS

MBTS

TMTD

PVI
(CTP)

S

Truck & Bus Tyres -   Tread
Sidewall
Casing

NR-BR
NR-BR
NR-SBR

1.1-1.2
0.9-1.0
0.8-1.2

-
-
-

-
-
-

0.15-0.20
0.15-0.20
0.15-0.20

1.5-1.6*
1.8-2.0*
2.0-2.4*

Conveyor Belt Cover
General Purpose
Heat Resistant


NR
NR-SBR


0.6-0.8
1.5


0.1-0.3
-


-
0.5


0.10-0.20
0.15-0.20


2.3-2.5
0.5-0.7

V Belts  Base
Cushion
Friction

NR
NR
NR

0.5
0.5
0.6

0.2
0.2
0.2

-
-
-

0.10-0.20
0.15-0.20
0.15-0.20

3.0
2.4
2.75

Retreads  Hot Cure

Pre Cured

NR
NR-BR
NR-BR

0.5
0.8
1.0

-
-
0.2

-
-
-

0.15
0.15
0.10

2.4*
2.0*
1.6

Footwear             DV Soles
Molded Soles & Heels

NR-SBR
NR-SBR

0.8
0.8

0.4
-

0.1
0.2

0.10
0.10

2.0
2.2

Injection Moldings

NR

0.7

-

-

0.25

2.4

Molded & Extruded Goods

NR
NR-SeEV
NR-EV

SBR
SBR-SeEV
SBR-EV

NBR
NBR-SeEV
NBR-EV

0.7-0.8
1.5-2.0
2.5-3.0

1.0-1.2
1.5-2.5
1.5

1.0-1.2
1.5-1.2
2.0

0.1
-
-

0.2
-
-

0.2
-
-

0.0-0.2
0.3-0.5
0.5-0.6

0.1-0.2
0.5
2.5-3.5

0.1-0.2
0.5-0.7
3.0-4.0

0.10-0.20
0.10-0.20
-

-
-
-

-
-
-

2.2-2.5
0.8-1.0
0.3-0.5

2.0-2.2
0.7-1.0
0.3-0.5

1.5
0.75
0.3

Note:   *   Insoluble Sulphur (100% active content basis)