Pneumatic object provided with a gastight layer containing a thermoplastic elastomer and a platy filler
View Patent ↗An inflatable article is provided with a layer impermeable to inflation gases. The layer has an elastomer composition that includes at least, as a predominant elastomer by weight, a thermoplastic styrene (TPS) elastomer and a platy filler. The platy filler has an equivalent diameter (Dv (0.5)) of between 20 and 45 micrometers, and has a shape factor (F) greater than 65.
1. An inflatable article comprising a gastight layer impermeable to inflation gases,
wherein the gastight layer is formed of at least an elastomer composition that includes:
a thermoplastic styrene (TPS) elastomer, the thermoplastic styrene (TPS) elastomer being a predominant elastomer by weight; and
a platy filler,
wherein the platy filler has an equivalent diameter (D V (0.5)) of between 20 and 45 micrometers, and
wherein in that the platy filler has a shape factor (F) greater than 65 with:
F
=
S
BET
S
sphere
=
ρ
S
BET
D
V
(
0.5
)
6
,
in which:
S BET is a specific surface area of the platy filler, in m 2 /g, measured by a BET method,
S sphere is a specific surface area of a sphere having a same density and an identical equivalent diameter (D V (0.5)), in m 2 /g, as the platy filler,
D V (0.5) is an equivalent diameter, in μm, and
ρ is a density of the platy filler, in g/cm 3 .
2. An inflatable article according to claim 1 , wherein the thermoplastic styrene (TPS) elastomer includes a butyl-based elastomer block.
3. An inflatable article according to claim 1 , wherein the thermoplastic styrene (TPS) elastomer is a copolymer that includes styrene and isobutylene blocks.
4. An inflatable article according to claim 1 , wherein the thermoplastic styrene (TPS) elastomer is a styrene/isobutylene/styrene copolymer.
5. An inflatable article according to claim 1 , wherein the elastomer composition further includes an extender oil for the thermoplastic styrene (TPS) elastomer.
6. An inflatable article according to claim 5 , wherein the extender oil for the thermoplastic styrene (TPS) elastomer is a polyisobutylene oil.
7. An inflatable article according to claim 1 , wherein the platy filler is chosen from a group that includes graphites, phyllosilicates, and mixtures of graphites and phyllosilicates.
8. An inflatable article according to claim 1 , wherein the platy filler includes one or more micas.
9. An inflatable article according to claim 1 , wherein the platy filler is present at a content between 2 and 30 vol %.
10. An inflatable article according to claim 1 , wherein the platy filler is present at a content between 3 and 20 vol %.
11. An inflatable article according to claim 1 , wherein the gastight layer has a thickness greater than 0.05 mm.
12. An inflatable article according to claim 1 , wherein the gastight layer has a thickness between 0.1 mm and 10 mm.
13. An inflatable article according to claim 1 , wherein the gastight layer has a thickness between 0.1 and 1.0 mm.
14. An inflatable article according to claim 1 , wherein the gastight layer is positioned on an inner wall of the inflatable article.
15. An inflatable article according to claim 1 , wherein the inflatable article is formed of rubber.
16. An inflatable article according to claim 15 , wherein the inflatable article is a pneumatic tire.
17. An inflatable article according to claim 1 , wherein the inflatable article is an inner tube.
18. An inflatable article according to claim 15 , wherein the inner tube is an inner tube for a pneumatic tire.