Tyre with self-sealing layer

#The present invention relates to a tubeless tyre that includes a self-sealing layer placed on its inner wall so as to seal off any perforations in service.

#The problem of punctures, namely the problem of how to enable a vehicle to continue its travel despite a substantial or complete loss of pressure of one or more of its tyres or how to avoid a loss of air following a perforation, dates back from the very start of the use of wheels fitted with inflated tyres.

#One solution very often proposed is to add a self-sealing layer to the inner wall of the tyre.

#All the embodiment details are given in the following description, which is supplemented by FIGS. 1 to 14 in which:

#FIG. 1 shows schematically a radial cross section of a tyre incorporating a self-sealing layer according to the invention;

#FIG. 2 shows a partial radial cross section of a cycle tyre incorporating a self-sealing laminate according to the invention;

#The Shore 0 hardness values are obtained in accordance with the ASTM D 2240 standard. The measurements are carried out 10 seconds after application of the indenter.

#The dynamic properties of the elastomer materials are obtained using an RPA 2000 rheometer from the company Alpha Technologies. The specimens are placed in a chamber between two striated biconical plates. After closure, the volume of the chamber is around 4.5 cm3. One of the plates is fixed, the other oscillating sinusoidally about its centre. A deformation of around 20% is imposed and a frequency scan carried out between 0.03 Hz and 33 Hz. The imposed temperature inside the chamber is 60° C. The results exploited are the dynamic shear modulus G* and the loss factor tan δ, where: G*=√{square root over (G′2+G″2)} and tan δ=G″/G′

#G*: dynamic shear modulus in MPa;