Aqueous dispersion of polyisobutylene and polyolefin particles

A composition comprising an aqueous dispersion of a) polyisobutylene particles;

• and b) polyolefin particles, which are polyethylene or polypropylene particles, wherein the weight-to-weight ratio of the polyisobutylene particles to the polyolefin particles is in the range of from 20:80 to 80:20;
• wherein the composition has a solids content arising from the polyisobutylene and the polyolefin particles in the range of from 20 to 60 weight percent;
• wherein the polyisobutylene and polyolefin particles having a D90 particle size in the range of from 0.1 μm to 12 μm.