Table 2. Formulation of CR Compound (unit: phr)

Ingredients		Compounds
		VN3/CR	Z175/CR	U7000/CR
Rubber	CR	100	100	100
Fillers	VN3	0, 20, 40, 60, 70, 80
	Z175		0, 20, 40, 60, 70, 80
	U7000			0, 20, 40, 60, 70, 80
Additives	Si-69	0, 1.6, 3.2, 4.8, 5.6, 6.4	0, 1.6, 3.2, 4.8, 5.6, 6.4	0, 1.6, 3.2, 4.8, 5.6, 6.4
	MgO	4	4	4
	Na-22a	1.5	1.5	1.5
	DMb	1.5	1.5	1.5
	DOSc	10	10	10
	Paraffin wax	2.5	2.5	2.5
	ZnO	5	5	5

Na-22 and
DM: Crosslinking accelerator,
DOS: Plasticizer