New reinforcing organic fillers for elastomeric compounds and tyres that comprise them

A terminated (poly)urethane, (poly)urea, or (poly)urethane and (poly)urea oligomer (I) suitable as reinforcing material for an elastomeric tyre compound,

• wherein the terminated (poly)urethane, (poly)urea oligomer, or (poly)urethane and (poly)urea oligomer (I) is obtained by reaction of:
• at least one polyisocyanate (II),
• at least one polyol (III-I), one polyamine (III-II), or one polyol (III-I) and one polyamine (III-II) with molecular weight lower than 400 g/mol,
• wherein polyisocyanate (II) and polyol (III-I), polyamine (III-II), or polyol (III-I) and polyamine (III-II) are used in the reaction in quantities to provide isocyanate groups and hydroxyl, amino, or hydroxyl and amino groups in molar ratio of isocyanate groups to hydroxyl, amino, or hydroxyl and amino groups ranging from 3:1 to 1.1:1, and to contribute no more than 5000 g/mol to the weight average molecular weight (MW) of the terminated oligomer (I), and
• at least one monoalcohol or at least one monoamine of formula (IV):
• X—Y—H (IV)
• wherein
• X is an organic residue comprising at least one reactive group capable of covalently binding to the diene polymers of the elastomeric compound under vulcanisation conditions or at least one hydrophobic group with high affinity for the diene polymers;
• and
• Y is —O— or —NR2— , wherein R2 is selected from H, C1-C18, linear or branched, saturated or unsaturated alkyl, optionally substituted C5-C6 cycloalkyl, an aromatic group, optionally substituted by one or more linear or branched C1-C18, a heteroaromatic group comprising from 1 to 3 heteroatoms, optionally substituted by one or more C1-C18, linear or branched, saturated or unsaturated alkyls,
• wherein, the terminated (poly)urethane, (poly)urea, (poly)urethane and (poly)urea oligomer (I) has a weight average molecular weight MW lower than 25000 g/mol measured by gel permeation chromatography.