Modified moldable urethane with tunable haptics
View Patent ↗The present invention relates to a slush moldable polymeric composition for forming a skin useable in interior trim components and methods of making the same. In at least one embodiment, the composition comprises a) from 50 to 99 wt. percent urethane elastomer, b) from 0.1 to 15 wt. percent propylene copolymer, c) from 0.1 to 25 wt. percent olefin modified thermoplastic, such as SEBS, and d) from 0.1 to 30 weight percent olefinic block copolymer, wherein the polymeric composition is slush moldable and vacuum formable. The modifiers include an olefin block copolymer (OBC) having a variable distribution of block lengths. The OBC is present in an amount from 0.1% to 30% of the total composition. The haptics of the polymeric composition is tunable by adjusting the amounts of the modifiers.
1. A polymeric composition comprising:
a) from 50 to 99 wt. percent urethane elastomer;
b) from 0.1 to 15 wt. percent propylene copolymer;
c) from 0.1 to 25 wt. percent olefin modified thermoplastic; and
d) from 0.1 to 30 wt. percent olefinic block copolymer having a variable distribution of block lengths;
wherein the polymeric composition is slush moldable and vacuum formable.
2. The composition of claim 1 , wherein the olefinic block copolymer is present in an amount from 5.0 to 12.5 wt. percent.
3. The composition of claim 1 , wherein the olefin modified thermoplastic comprises SEBS block copolymer present in an amount from 7.5 to 15 wt. percent and has a Shore A hardness of 50 to 60 and a density of 0.95 to 1.05 g/cm 3 .
4. The composition of claim 1 , wherein the propylene copolymer comprises propylene-ethylene copolymer present in an amount from 5 to 7.5 wt. percent and has a Shore A hardness of 60 to 70, a percent crystallinity of no more than 20 wt. percent and a density of 0.8 to 0.9 g/cm 3 .
5. The composition of claim 1 , further comprising 0.5 to 2.5 wt. percent of a surface modified montmorillonite nanoclay.
6. The composition of claim 1 , further comprising no more than 10 wt. percent of an olefin- or TPU-based pigment.
7. The composition of claim 1 , wherein the urethane elastomer is present in an amount from 60 to 70 wt. percent.
8. The polymeric composition of claim 1 , wherein the composition comprises:
a) from 60 to 70 wt. percent urethane elastomer;
b) from 5.0 to 7.5 wt. percent propylene-ethylene copolymer;
c) from 7.5 to 15 wt. percent SEBS;
d) from 5.0 to 12.5 wt. percent olefinic block copolymer; and
e) from 0.5 to 2.5 wt. percent surface modified montmorillonite nanoclay;
wherein the polymeric composition is slush moldable.
9. The composition of claim 2 , wherein the olefinic block copolymer has a Shore A hardness of 70 to 80 and a density of 0.8 to 0.9 g/cm 3 .
10. The composition of claim 5 , wherein the surface modified montmorillonite nanoclay is present in an amount from 1.0 to 2.0 wt. percent.
11. The composition of claim 8 , further comprising 0.1 to 8.0 wt. percent pigment.
12. A skin for a vehicle interior component, the skin comprising the dried product of a composition comprising:
a) from 50 to 99 wt. percent urethane elastomer;
b) from 0.1 to 15 wt. percent propylene-ethylene copolymer;
c) from 0.1 to 25 wt. percent SEBS; and
d) from 0.1 to 30 wt. percent olefinic block copolymer having a variable distribution of block lengths; and wherein the skin has a thickness from 0.3 to 3.0 mm and a Shore A hardness from 60 to 90.
13. The skin of claim 12 , wherein the Shore A hardness is from 65 to 85.
14. The skin of claim 12 , wherein the Shore A hardness is from 70 to 80.
15. The skin of claim 12 , wherein the skin has a porosity of less than 2.0%.
16. The skin of claim 12 , wherein the tensile strength of the skin is from 3.0 to 6.0 MPa.
17. The skin of claim 12 , wherein the tear strength of the skin is from 15 to 35 kN/m.
18. The skin of claim 12 , wherein the density of the skin is from 1.0 to 1.10 g/cm 3 .
19. A method of forming a skin for a vehicle interior component, the method comprising:
providing particles having a polymeric composition comprising:
a) from 60 to 70 wt. percent urethane elastomer;
b) from 5.0 to 7.5 wt. percent propylene-ethylene copolymer;
c) from 7.5 to 15 wt. percent SEBS;
d) from 5.0 to 12.5 wt. percent olefinic block copolymer having a variable distribution of block lengths; and
e) from 0.5 to 2.5 wt. percent surface modified montmorillonite nanoclay; providing a mold tool; introducing the mold tool into a container having the polymeric particles disposed therein; disposing the particles onto the mold tool; heating the mold tool to form a layer of polymeric material over at least a portion of the mold tool; cooling the polymeric material to form a skin over the mold tool; and removing the mold tool from the container; wherein the skin that is formed has a thickness from 0.3 to 3.0 mm and a Shore A hardness from 60 to 90.
20. The method of claim 19 wherein component, the method comprises:
providing a sheet having a composition comprising:
a) from 60 to 70 wt. percent urethane elastomer;
b) from 5.0 to 7.5 wt. percent propylene-ethylene copolymer;
c) from 7.5 to 15 wt. percent SEBS;
d) from 5.0 to 12.5 wt. percent olefinic block copolymer; and
e) from 0.5 to 2.5 wt. percent surface modified montmorillonite nanoclay;
providing a mold tool;
heating the sheet such that it becomes pliable;
disposing the sheet over the mold tool;
applying a vacuum to the mold tool, causing the sheet to substantially have the shape of the mold tool; and
removing the formed skin from the mold tool;
wherein the skin that is formed has a thickness from 0.3 to 3.0 mm and a Shore A hardness from 60 to 90.