Brueggemann TP 1862

Steel-cord adhesion mixtures are commonly used in tires and other applications such as hoses or conveyor belts. In such mixtures, state-of-the-art technology uses systems containing cobalt salts as catalysts or co-accelerators and adhesion promotors, as well as resorcinol resins to achieve desired mechanical properties.

As both cobalt and cobalt salts, on one hand, and resorcinol, or resorcinol-based resins on the other hand, are deemed to be problematic from an environmental safety and health (ESH) point of view, it is worthwhile finding a solution to reduce – or even eliminate – such critical substances from modern rubber mixtures. The elimination of resorcinol is already realized by a novolakbased reinforcing resin.

A combination of this novolak-based resin together with a zinc-based catalyzing additive additionally allows the elimination of cobalt and cobalt salts from steelcord adhesion mixtures without sacrificing vulcanization activity, mechanical properties and adhesion characteristics.

• No cobalt
• No resorcinol
• High adhesion to steel
• High mechanical properties
• Low zinc and heavy metal content

Additive package 1: Cobalt salt, resorcinol and standard ZnO
Additive package 2: Zinc- and novolak-based additive package without cobalt and resorcinol

Fig. 1: Rheometer curves measured at 155 °C.

Fig. 2: Pull-out force values according to ASTM D 2229-02

Fig. 3: Improvement of mechanical properties of cobalt- and resorcinol-free system compared to standard system (in percent)

Scheme 1: Elimination of cobalt and resorcinol from adhesion mixtures by application of TP 1862. 

Scheme 2: Rheometer data for TP 1862 at T > 150 °C, t = 30 min.

Rheometer curves for steel-cord adhesion mixtures that contain TP 1862 show significantly higher torque values - which indicates a high crosslink density. Mechanical tests reveal outperforming values as well, e.g., in stress elongation or in Shore D.

Scheme 3: Shore D value and stress elongation for steel-cord adhesion mixture vulcanized with TP 1862

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Picture 1: Granules of TP 1862.

Scheme 4: Retention of pull-out-force (POF-values) for standard formulation (recipe 1) and steel-cord adhesion mixture vulcanized with TP 1862 (recipe 2) in aging test

Strong adhesion strength is a primary prerequisite for durable tires. Vulcanization with TP 1862 leads to steel-cord adhesion mixtures with much higher retention of pull-out-force (POF-values) in aging tests.

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Picture 2: Retention of pull-out-force (POF-values) for standard formulation (recipe 1) and steel-cord adhesion mixture vulcanized with TP 1862 (recipe 2) in aging test.

• Brueggemann TP 1862 is classified as hazardous according to the valid CLP-Regulation (H400 and H410, very toxic to aquatic life – with long lasting effect). Before commencement of operations a risk assessment must be carried out. To this end, and for ensuring the necessary protective measures, the associated safety data sheet must be noted. In addition, it must be checked whether the stated identified uses resp. specified application conditions in the safety data sheet are met.
• The aforementioned remarks are deducted from the European legal system. Deviating or additional regulations in other legal systems must be observed accordingly when using the product.