Alloy blends of polyurethane and latex rubber
View Patent ↗Disclosed herein are barrier articles of polyurethane blends or alloys that limit the permeability of gases there through, particularly as used in inflatable sports articles and more particularly as used in soccer balls.
1. A formulation comprising an aqueous dispersion; said aqueous dispersion comprising
an unsaturated polyurethane, at least a portion of which comprises at least one anionic, cationic, allyl, or vinyl group; and
latex comprising an elastomeric polymer;
the unsaturated groups of the polyurethane being capable of chemically bonding with the latex; said formulation being formable into a film having an air permeability not greater than 3.5×10 −5 cm 3 cm/m 2 hour Pa at 25° C. wherein said air permeability is calculated as:
(
Flow
rate
of
air
in
cm
3
/
hour
)
×
(
Thickness
of
film
in
cm
)
(
Permeation
area
of
film
in
m
2
)
×
(
Pressure
differential
across
film
i
n
Pa
)
wherein a pressure differential of 50 psig is maintained during measurement.
2. The formulation of claim 1 , wherein the polyurethane is derived from a polyether glycol.
3. The formulation of claim 1 , wherein the polyurethane is derived from a polyester glycol.
4. The formulation of claim 2 , wherein the polyether glycol is derived from a polytetramethylene glycol, polypropylene glycol, polyethylene glycol, polyethylene-polytetramethylene copolymer glycol, or polyethylene-polypropylene copolymer glycol.
5. The formulation of claim 3 , wherein the polyester glycol is derived from one or more difunctional carboxylic and one or more difunctional hydroxyl compounds.
6. The formulation of claim 1 , comprising at least 10% by weight of polyurethane (dry weight basis).
7. The formulation of claim 1 , comprising at least 40% by weight of polyurethane (dry weight basis).
8. The formulation of claim 1 , wherein the elastomeric polymer is selected from the group consisting of styrene-butadiene, styrene-isoprene and polyacrylates.
9. The formulation of claim 1 , wherein the polyurethane is derived from polybutylene adipate.
10. The formulation of claim 1 , wherein the unsaturated groups comprise allyl or vinyl.
11. A formulation comprising an aqueous dispersion; said aqueous dispersion comprising
polyurethane, at least a portion of which has unsaturated groups; and
latex;
the unsaturated groups of the polyurethane being capable of chemically bonding with the latex; said formulation being formable into a film having an air permeability not greater than 3.5×10 −5 cm 3 cm/m 2 hour Pa at 25° C. wherein said air permeability is calculated as:
(
Flow
rate
of
air
in
cm
3
/
hour
)
×
(
Thickness
of
film
i
n
cm
)
(
Permeation
area
of
film
in
m
2
)
×
(Pressure differential across film in Pa)
wherein a pressure differential of 50 psig is maintained during measurement; wherein the latex comprises at least one of polyisoprene, polybutadiene and blends of polyisoprene and polybutadiene.
12. The formulation of claim 11 , wherein the latex is polyisoprene.
13. The formulation of claim 12 , wherein the polyisoprene is natural or synthetic.
14. The formulation of claim 11 , wherein the polyurethane is derived from a polyether glycol.
15. The formulation of claim 14 , wherein the polyether glycol is derived from a polytetramethylene glycol, polypropylene glycol, polyethylene glycol, polyethylene-polytetramethylene copolymer glycol, or polyethylene-polypropylene copolymer glycol.
16. The formulation of claim 11 , comprising at least 10% by weight of polyurethane (dry weight basis).
17. The formulation of claim 11 , comprising at least 40% by weight of polyurethane (dry weight basis).
18. The formulation of claim 11 , wherein the polyurethane is derived from a polyester glycol.
19. The formulation of claim 18 , wherein the polyester glycol is derived from one or more difunctional carboxylic and one or more difunctional hydroxyl compounds.
20. The formulation of claim 11 , wherein the polyurethane is derived from polybutylene adipate.