Smoking rod wrappers and compositions for their production

A smoking rod wrapper material having porosity apertures within a coated area in which the apertures are partially or fully blocked by a coating of a heat-removable porosity-reducing composition and in which the apertures have a maximum dimension of below 80 .mu.m, the amount of the composition in the coated area is 0.05 to 1 mg/cm.sup.2 and the composition will melt or volatilise upon the approach of the burning tip of the smoking rod, whereby the coated area of the wrapper in the 10 mm behind the burning tip will have a porosity at least 50%, measured in Corestas, greater than the initial porosity of the coated area.

A smoking rod wrapper material having porosity apertures within a coated area in which the apertures are partially or fully blocked by a coating of a heat-removable porosity-reducing composition and in which the apertures have a maximum dimension of below 80 .mu.m, the amount of the composition in the coated area is 0.05 to 1 mg/cm.sup.2 and the composition will melt or volatilise upon the approach of the burning tip of the smoking rod, whereby the coated area of the wrapper in the 10 mm behind the burning tip will have a porosity at least 50%, measured in Corestas, greater than the initial porosity of the coated area and in which the porosity-reducing composition comprises (a) 0 to 20% by weight polymeric binder and (b) 80 to 100% by weight of a non-polymeric blocking material that is solid at 30.degree. C. and that, at a temperature between 30.degree. and 150.degree. C., melts and is absorbed into the substrate or volatilises.

A smoking rod wrapper material having porosity apertures within a coated area in which the apertures are partially or fully blocked by a coating of a heat-removable porosity-reducing composition, and in which the composition comprises (a) 0 to 20% by weight polymeric binder and (b) 80 to 100% by weight of a non-polymeric blocking material that is solid at 30.degree. C. and that, at a temperature between 30.degree. and 150.degree. C., melts and is absorbed into the substrate or volatilises, and thereby leaves the apertures substantially unblocked, the non-polymeric blocking material being a fatty alcohol, fatty acid ester, fatty acid or fatty acid salt or a mixture thereof.

A smoking rod wrapper material having porosity apertures within a coated area in which the apertures are partially or fully blocked by a coating of a heat-removable, porosity-reducing composition, and in which the composition comprises (a) 5 to 20% by weight polymeric binder and (b) 80 to 95% by weight of a non-polymeric blocking material that is solid at 30.degree. C. and that, at a temperature between 30.degree. and 150.degree. C., melts and is absorbed into the substrate or volatilises, and thereby leaves the apertures substantially unblocked.