Borregaard’s Lignin

Borregaard develops wood-derived lignin as a chemical material.
Its main products are lignosulfonate-based and are supplied as water-soluble powders.

A representative product line is Borresperse.

• Sodium type (NA)
• Calcium type (CA)
• Ammonium type (AM)

All of them share the same basic functions.

• Dispersant
• Binder

In fact, Borresperse AM is explicitly described for use as a dispersant or binder.

It is also water-soluble and compatible with many organic and inorganic materials.

At this point, its role is entirely different from that of the main rubber component.

How It Enters Tire Materials

Lignin is not a substitute for rubber. It enters on the interfacial side.

Its expected roles are limited.

• Carbon black dispersion aid
• Filler wetting agent
• Binder in the green tire stage

Because lignosulfonate functions as a dispersant,
it is natural for it to be used in powder dispersion systems.

Especially in the dispersion of CB and silica, it may act through

• Suppression of aggregation
• Stabilization of dispersion

in that form.

However, because it is water-soluble,
phase separation occurs if it is added directly into a rubber compound.

This is the first constraint.

Structural Constraints

The issues with lignin are clear.

• High polarity
• Weak thermoplasticity
• Low compatibility with rubber

Borresperse is a water-soluble powder,
and uniform dispersion inside rubber is not its design premise.

In practice, the product is designed as

• Water-soluble
• Powder
• For dispersant use

That means

“a material used in aqueous systems”

and not something designed to be placed directly into the internal phase of rubber.

Actual Application Range

Realistically, its applications are limited.

• Latex-based rubber
• Water-based processes
• Pretreatment steps

For example, it is consistent with

• Filler dispersion in latex
• Premix processes
• Powder binder use

in these cases.

By contrast, in

• Dry mixing (Banbury)
• Tread compounds

application is difficult.

Relationship with Carbon Black

Structurally, the relationship is not antagonistic but complementary.

• CB
　Reinforcing material

• Lignin
　Dispersion and interfacial control

What matters, however, is that

lignin does not replace CB.

Because the reinforcing performance is fundamentally different,
its role is not substitution but peripheral functionality.

Summary

Borregaard’s lignin is designed as a

• Dispersant
• Binder

In tire applications, its position is that of

• Not a direct material
• Used at the interface or in pretreatment

That is where it belongs.

It is not a main material,
but rather a material positioned closer to the process side.

Sources and References

• Borregaard Borresperse AM 870P PDS
• Borresperse NA Product Specification, Borresperse CA SDS