Abstract: A method of forming a puncture preventing layer on an innner surface of a pneumatic tire including the steps of extruding sealing material and pulverizing the extruded sealing material into fine particles for coating the inner surface with a layer of the sealing material under pressure through action of centrifugal force. For effecting the above described method in an efficient manner, there is also provided a puncture preventing layer forming apparatus which includes arrangements for holding the tire, extruding the sealing material, and pulverizing the extruded sealing material so as to be coated onto the inner surface of the tire through the action of centrifugal force.

Abstract: A method of forming a puncture preventing layer on an inner surface of a pneumatic tire including the steps of extruding sealing material and pulverizing the extruded sealing material into fine particles for coating the inner surface with a layer of the sealing material under pressure through action of centrifugal force. For effecting the above described method in an efficient manner, there is also provided a puncture preventing layer forming apparatus which includes arrangements for holding the tire, extruding the sealing material, and pulverizing the extruded sealing material so as to be coated onto the inner surface of the tire through the action of centrifugal force.

Abstract: Pneumatic tire including a puncture sealing layer which is applied to an inner lining and in which by addition of specific amounts of polyisobutylene and of a particular form of silica with respect to a set amount of polybutene and by use of powdered elastomer having a specific particle size distribution there are achieved optimum values of viscosity and adhesivity and ability to seal even large puncture holes in a wide range of temperature and operating conditions. In addition there is less tendency for puncture sealing layer components to migrate to the inner lining and tire durability is therefore improved.