This invention relates to flexible cycloaliphatic diisocyanate trimers and a process for the preparation of these. These flexible products are allophanate-modified, partially trimerized cycloaliphatic diisocyanates and are characterized by a low Tg. More specifically, the Tg of the resultant product ranges from about −30° C. to about 40° C., after the excess monomer has been removed from the product.