Hollow polymer particles for thermal insulation
AssigneeArkema Inc.
InventorsLily Liu, Daniel E. Stark, Wayne Devonport, Donovan K. Lujan
Life of this patent
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Abstract
A thermal insulating additive, product formed therefrom, and method of making the same, wherein the thermal insulating additive comprises a plurality of hollow polymeric particles having an average particle size up to about 0.3 micrometers. The hollow polymeric particles exhibit a mechanical strength in a compression test up to about 420 psi and a thermal conductivity that is less than 0.150 W/m-k. The hollow polymeric particles are individually formed as an alkaline swellable core that is at least partially encapsulated with two or more shell layers; the alkaline swellable core prior to swelling exhibits an average particle size that is less than about 50 nanometers.
Claims20
A thermal insulating additive, the thermal insulating additive comprising a plurality of hollow polymeric particles having an average particle size from about 0.2 to about 0.3 micrometers;
- said hollow polymeric particles formed from an alkaline swellable core that is at least partially encapsulated with two or more shell layers, wherein the alkaline swellable core prior to swelling exhibits an average particle size that is less than 50 nanometers (0.05 micrometers) and the shell layers are more hydrophobic than the swellable core;
- at least one of said two or more shell layers being an inner/first shell layer that at least partially encapsulates the swellable core and the other of said two or more shell layers being an outer/second shell layer that at least partially encapsulates the inner/first shell layer and the swellable core;
- wherein the glass transition temperature (Tg) of the outer/second shell layer is equal to or less than the glass transition temperature (Tg) of the inner/first shell layer;
- and
- wherein the hollow polymeric particles exhibit a mechanical strength in a compression test up to about 420 psi and a thermal conductivity that is less than 0.150 W/m-k.
A method of forming thermal insulating additive, the method comprising:
- providing a plurality of hollow polymeric particles;
- the hollow polymeric particles being individually formed as an alkaline swellable core that is at least partially encapsulated with two or more shell layers;
- the alkaline swellable core exhibiting an average particle size that is less than about 50 nanometers;
- allowing the alkaline swellable core in each hollow polymeric particle to swell, such that the hollow polymeric particles exhibit an average particle size up to about 0.3 micrometers;
- and
- collecting the swollen hollow polymeric particles to form the thermal insulating additive;
- wherein the hollow polymeric particles exhibit a mechanical strength in a compression test up to about 420 psi and a thermal conductivity that is less than 0.150 W/m-k;
- wherein the shell layers are more hydrophobic than the swellable core.
Dependencies are inferred from the claim text.