Hybrid acoustic interlayer consisting of an adhesive core layer made of polymer-matrix nanocomposites
An interlayer for laminated glasses, includes two outer layers of a material selected from poly(vinyl butydownral) (PVB) and poly(ethylene-vinyl acetate) (EVA), assembled by an adhesive nanocomposite layer including a first, discontinuous phase consisting of polymeric nanodomains having a glass transition temperature (Tg) of between −50° C. and −30° C., and a second, continuous polymeric phase, referred to as the matrix, having a glass transition temperature (Tg) lower than that of the first phase, the first phase being dispersed in the second phase.
1. An interlayer for laminated glasses, comprising two outer layers of a material selected from poly(vinyl butyral) (PVB) and poly(ethylene-vinyl acetate) (EVA), assembled by an adhesive nanocomposite layer comprising:
a first, discontinuous phase consisting of polymeric nanodomains having a glass transition temperature (Tg) of between −50° C. and −30° C., and
a second, continuous polymeric phase having a glass transition temperature (Tg) lower than that of said first phase,
the first phase being dispersed in the second phase.
2. The interlayer for laminated glasses as claimed in claim 1 , wherein the two outer layers are layers of poly(vinyl butyral) (PVB).
3. The interlayer for laminated glasses as claimed in claim 1 , wherein the polymeric nanodomains of the first phase are formed of an interpenetrating polymer network comprising a first polymer, which is crosslinked, and a second polymer which is crosslinked or non-crosslinked.
4. The interlayer for laminated glasses as claimed in claim 1 , wherein the polymeric nanodomains forming the first phase have a number-average equivalent diameter of between 10 and 1000 nm.
5. The interlayer for laminated glasses as claimed in claim 1 , wherein said adhesive nanocomposite layer has a thickness of between 5 and 50 micrometers.
6. The interlayer for laminated glasses as claimed in claim 3 , wherein the second polymer is non-crosslinked.
7. The interlayer for laminated glasses as claimed in claim 3 , wherein the first polymer has a Tg of greater than −30° C.
8. The interlayer for laminated glasses as claimed in claim 3 , wherein the second polymer has a Tg of less than −50° C.
9. The interlayer for laminated glasses as claimed in claim 7 , wherein the difference between the Tg of the first polymer and the Tg of the second polymer is between 10° C. and 60° C.
10. The interlayer for laminated glasses as claimed in claim 3 , wherein the first and second polymers are acrylic copolymers, comprising at least one acrylic monomer.
11. The interlayer for laminated glasses as claimed in claim 1 , wherein a difference between a refractive index of the first phase and a refractive index of the second phase is less than 0.2.
12. The interlayer for laminated glasses as claimed in claim 1 , wherein the adhesive nanocomposite layer is directly in contact with the two outer layers.
13. The interlayer for laminated glasses as claimed in claim 1 , wherein a ratio of a volume of the first phase to a volume of the second phase is between 20/80 and 80/20.
14. A laminated glazing unit comprising:
a first glass sheet,
a second glass sheet,
an interlayer as claimed in claim 1 , the interlayer being arranged between the first and second glass sheets.
15. The interlayer for laminated glasses as claimed in claim 1 , wherein the first, discontinuous phase consisting of polymeric nanodomains has a glass transition temperature (Tg) of between −45° C. and −35° C., and wherein the second, continuous polymeric phase has a glass transition temperature (Tg) of less than −50° C.
16. The interlayer for laminated glasses as claimed in claim 4 , wherein the number-average equivalent diameter is between 20 and 400 nm.
17. The interlayer for laminated glasses as claimed in claim 5 , wherein the thickness is between 10 and 30 micrometers.
18. The interlayer for laminated glasses as claimed in claim 7 , wherein the first polymer has a Tg of greater than −20° C.