Pilflex 13 is an alkyl-aryl-PPD antidegradant most widely used in the tyre and non-tyre sector of the rubber industry. Pilflex 13 offers excellent resistance to rubber vulcanizates against degradative forces such as ozone (static as well as dynamic), flex-cracking and fatigue, oxidative heat ageing, metal-ion catalyzed oxidative ageing, UV light and weathering. Pilflex 13 pastilles are easy to handle on all types of weighing systems and quickly disperse in rubber compounds even at lower processing temperatures.
Pilflex 13 is the most suitable PPD antidegradant for NR, NR-BR blend, SBR, SBR-BR blend, NBR, IR, IIR and polychloroprene based compounds and is preferred over Pilflex IP due to its higher molecular weight, low volatility, lower water leaching / oil and fuel extraction rates, balanced migration rates and non-toxic nature with respect to skin sensitization. Pilflex 13 is not recommended for white / colored products since it can cause severe discoloration as well as contact / migration staining. Pilflex 13 exhibits very good solubility in general purpose rubbers and its mobility is further improved in the presence of paraffin / microcrystalline / blended wax.
Pilflex 13 tends to decrease the viscosity of the rubber compounds and also acts as a very mild amine activator of cure. However, as compared to Pilflex IP, it shows negligible effect on scorch / cure activation. Pilflex 13 is particularly suitable for polychloroprene based compounds where only small dosages, e.g. 0.5 phr, show marked improvement in ozone and flex-fatigue resistance and it is also very effective antiozonant for NBR based compounds where lower extractability of antidegradants in oils and fuels is a primary requirement. Pilflex 13 is an effective antidegradant for butyl tubes to prevent strain induced cracking due to ozone attack at the folded edges of the packed tube.
Pilflex 13 alone can provide excellent protection to rubber vulcanizates against all degradative forces; however, it is generally used in combination with Pilnox TDQ for economic as well as technological advantages. Pilnox TDQ provides equivalent heat and oxidative ageing resistance at much lower cost (for which, otherwise, Pilflex 13 would have been consumed) and improves the flex-fatigue resistance of the rubber vulcanizates by 25 to 30% than if Pilflex 13 were used alone (particularly where higher dosages of Pilflex 13 have to be used).
Pilflex 13 (and other para phenylenediamine antidegradants) are always used along with 0.5-2.0 phr of paraffin / microcrystalline / blended wax. These waxes provide synergistic effect with antidegradants for enhancing the antiozonant and antiflex cracking characteristics. The waxes have the ability to act as carriers of the para phenylenediamine antidegradants over the surface of the rubber vulcanizate & the paraphenylene diamine antidegradants have the ability to increase the thickness and uniformity of wax bloom over the surface. The rubber product has to perform & the migration rates desired across the cross section of the single compound / multi-compound rubber product. The base compounding formulation design also plays an important role for selection of waxes.
Pilflex 13 along with waxes is widely used at 0.5-3.5 phr dosages as an antiozonant and anti flex-cracking system. Its combination with Pilnox TDQ in 1:1 ratio provides additional heat and flex-fatigue protection. For more severe conditions of flex – fatigue and ozone resistance, Pilflex13 / Pilnox TDQ ratio is increased to 2.0-3.5 : 1. Inclusion of Mixed Diaryl PPD at 0.5-1.0 phr as additional paraphenylene diamine antidegradant further improves flex-fatigue resistance and ensures persistency of the antidegradant system. For superior heat ageing resistance, Pilflex 13 -Antioxidant MBI combination in 1:1 ratio is used at 0.4-0.8 phr levels.
Pilflex 13 and its combinations with other antioxidants / antiozonants is used in the manufacture of Truck and Bus,OTR, LCV, Passenger Car, Motorcycle, Scooter, Industrial & Farm Tyres and Tubes, Bicycle Tyres & Tubes, Conveyor belts, V & Fan Belts, Power Transmission Belts, Cables, Hoses, Tubings and other miscellaneous Molded and Extruded rubber products based on NR, NR-BR, SBR, SBR-BR, NBR, IR, IIR, CR, EPDM, etc.
TYPICAL DOSAGES:
Typical dosages of Pilflex 13 / its combination with other antidegradants for various applications are given below:
TYPICAL DOSAGES OF PILFLex 13
|
Product
|
Antioxidant / Antiozonant / Wax , phr
|
Rubber
|
Pilflex 13
|
Pilnox TDQ
|
Blended Wax
|
Truck Tyres
Treads (Cross ply, Front Tyres)
Treads (Cross ply, Rear Tyres)
Treads (Radials)
Sidewall (Cross ply)
Sidewall (Radials)
Carcass (Cross ply)
Carcass (Radial) |
NR-BR
NR
NR-BR
NR-BR
NR-BR
NR
NR
|
2.5-3.5
3.0-3.5
3.0-3.5
2.7-3.0
3.0-4.0
0.7-1.0
0.7-1.0
|
1.0
1.0
1.0
1.0
1.0
1.0
1.0
|
0.7-1.0
0.7-1.0
0.7-1.0
1.5-2.0
1.5-2.0
-
-
|
Passenger Tyres (Radials)
Tread
Sidewall
Carcass
|
NR-SBR-BR
SBR-BR
NR-BR
NR/ NR-SBR
|
2.5-3.0
2.5-3.0
3.0-3.5
0.5
|
1.0
1.0
1.0
1.0
|
1.5
1.5
1.0
-
|
Motor cycle / Scooter Tyres
Tread
Carcass
|
SBR-BR
NR-SBR
|
1.75-2.0
0.5
|
1.0
1.0
|
1.0
-
|
Auto Tubes
|
IIR
NR
|
0.5
1.0
|
-
1.0
|
-
1.0
|
Flaps
|
NR/ NR-RR
|
0.5
|
1.0
|
1.0 *
|
Bicycle Tyre Treads
|
NR-RR
NR-BR-RR
|
0.5
0.5
|
1.0
1.0
|
1.0 *
1.0 *
|
Bicycle Tubes
|
NR
|
0.5
|
1.0
|
0.5 *
|
Cycle Tyre curing bags
|
NR
|
1.0
|
1.5-2.0
|
-
|
Retreads
Hot cure
Cold cure
Cushion gum
|
NR/NR-BR
NR-BR
SBR-BR
NR
|
0.5-0.75
1.0
1.0
-
|
1.0
1.0
1.0
1.0
|
0.5
0.7
0.7
-
|
Conveyor belt cover
|
NR
NR-SBR
|
1.0-1.5
1.0-1.5
|
1.0-1.5
1.0-1.5
|
0.5-0.7
0.5-0.7
|
V belts
Base
Cushion
|
NR
NR
|
1.0
0.5
|
1.0
1.0
|
-
-
|
Molded & Extruded goods
|
NR/NR-SBR
NBR
|
0.5-1.0
0.5-1.0
|
1.0
1.0
|
1.0 *
1.0 *
|
* Paraffin wax may be used
|