Puncture-sealing pneumatic tire and a method of producing the tire

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the FIGURE, the numerals 1, 2, 3 and 4 represent a tire, a bead portion, a side wall and a tread portion, respectively.
A puncture-sealing layer S having a thickness of t is adhered to the inner peripheral surface of a tire 1, said layer extending from the middle portion of one of the side walls 3 to the middle portion of the other side wall 3 along the back side of the tread portion 4.
In adhering the puncture-sealing layer S, the following three liquid rubber compositions A, B and C were used.
Liquid rubber composition A, which will be hereinafter abbreviated as liquid A, was prepared as follows.
240 g of EP 84X (trademark of EPDM made by Japan Synthetic Rubber Co.
, iodine value 12), 750 g of Polybutene 300R (trademark of polybutene made by Idemitsu Petroleum and Chemical Co.
, number average molecular weight 1,330, viscosity at 98.
9.
degree.
C 850 cst) and 210 g of Nipsil VN-3 (trademark of white carbon made by Nippon Silica Co.
) were thoroughly kneaded by a Brabender, and the resulting viscous rubber composition was diluted with 1,800 g of n-hexane to prepare the liquid rubber composition A.
The viscosity of the viscous rubber composition before the dilution, measured by a Koka type flow tester, was 8.
2.
times.
10.
sup.
4 poises at room temperature and under a shear rate of 100 sec.
sup.
-1.
The particle size of the white carbon dispersed in the vicscous rubber composition, which was measured by the above described method, was 12 .
mu.
m.
Liquid rubber composition B, which will be hereinafter abbreviated as liquid B, was prepared as follows.
290 g of Butyl 218 (trademark of IIR made by Japan Synthetic Rubber Co.
, unsaturation degree 1.
5 mol%) and 700 g of Polybutene 300R were kneaded together with 210 g of Nipsil VN-3, and the resulting viscous rubbr composition was diluted with 1,800 g of n-hexane to prepare the liquid rubber composition B.
The viscous rubber composition before the dilution, had a viscosity of 6.
1.
times.
10.
sup.
4 poises under the same measuring condition as that in the liquid A