Slush moldable thermoplastic polyolefin formulation for interior skin
A thermoplastic polyolefin composition suitable for slush molding comprising a blend of polypropylene, styrenic elastomer, linear low density polyethylene and a hydrocarbon-based process oil. Optional components include an ethylene copolymer elastomer, polymer additives such as polymer surface modifiers, powder flow additives, stabilizers and/or color pigments. The compositions exhibit a low melt viscosity during processing and improved surface quality for the molded article. An exemplary composition includes about 20-50 wt. % polypropylene or copolymer thereof, about 20-60 wt. % of a styrenic elastomer, about 5-50 wt. % linear low density polyethylene, and about 2-25 wt. % of a hydrocarbon-based process oil. The zero shear viscosity of the composition suitable for slush molding is in the range of about 300-900 Pa·s over a processing temperature range of 180-260° C.
1 . A thermoplastic polyolefin composition suitable for slush mold processing, comprising a blend of, on the basis of 100 parts by weight:
about 20-50 wt. % polypropylene or copolymer thereof,
about 20-60 wt. % styrenic elastomer, and
about 5-50 wt. % linear low density polyethylene,
wherein the composition has a zero shear viscosity of about 300-900 Pa·s over a processing temperature range of 180-260° C.
2 . The thermoplastic polyolefin composition of claim 1 further comprising up to about 40 wt. % ethylene copolymer.
3 . The thermoplastic polyolefin composition of claim 1 further comprising up to about 5 wt. % polymer surface modifier.
4 . The thermoplastic polyolefin composition of claim 1 further comprising up to about 10 wt. % powder flow additive.
5 . The thermoplastic polyolefin composition of claim 4 wherein the powder flow additive is one of inorganic particulate, hydrated silicate, talc, or montmorillonite clay, or a combination thereof.
6 . The thermoplastic polyolefin composition of claim 1 further comprising about 1 wt. % to about 4 wt. % of a heat stabilizer or a light stabilizer, or a combination thereof.
7 . The thermoplastic polyolefin composition of claim 1 wherein the polypropylene is a propylene-olefin copolymer comprising up to 15 wt. % olefin based on the total weight of the propylene-olefin copolymer.
8 . The thermoplastic polyolefin composition of claim 1 wherein the polypropylene has a Melt Flow Index in the range of about 40 to about 1200 g/10 min measured at 230° C. with a 2.16 kg weight.
9 . The thermoplastic polyolefin composition of claim 1 wherein the styrenic elastomer comprises a saturated aliphatic hydrocarbon-styrene copolymer having a molecular styrene content below 50 wt. % based on the total weight of the styrenic elastomer.
10 . The thermoplastic polyolefin composition of claim 1 wherein the polypropylene or copolymer thereof is present in an amount of about 25-35 wt. %.
11 . The thermoplastic polyolefin composition of claim 1 wherein the styrenic elastomer is present in an amount of about 25-45 wt. %.
12 . The thermoplastic polyolefin composition of claim 1 wherein the linear low density polyethylene is present in an amount of about 10-35 wt. %.
13 . The thermoplastic polyolefin composition of claim 1 wherein the composition has a zero shear viscosity of about 400-700 Pa·s at a processing temperature of 215° C.
14 . The thermoplastic polyolefin composition of claim 1 wherein the composition has a zero shear viscosity of about 450-600 Pa·s at a processing temperature of 215° C.
15 . A thermoplastic polyolefin composition suitable for slush mold processing, comprising a blend of, on the basis of 100 parts by weight:
about 20-50 wt. % polypropylene or copolymer thereof,
about 20-60 wt. % styrenic elastomer, and
about 2-25 wt. % hydrocarbon-based process oil,
wherein the composition has a zero shear viscosity of about 300-900 Pa·s over a processing temperature range of 180-260° C.
16 . The thermoplastic polyolefin composition of claim 15 further comprising up to about 40 wt. % ethylene copolymer.
17 . The thermoplastic polyolefin composition of claim 15 further comprising up to about 5 wt. % polymer surface modifier.
18 . The thermoplastic polyolefin composition of claim 15 further comprising up to about 10 wt. % powder flow additive.
19 . The thermoplastic polyolefin composition of claim 18 wherein the powder flow additive is one of inorganic particulate, hydrated silicate, talc, or montmorillonite clay, or a combination thereof.
20 . The thermoplastic polyolefin composition of claim 15 further comprising about 1 wt. % to about 4 wt. % of a heat stabilizer or a light stabilizer, or a combination thereof.
21 . The thermoplastic polyolefin composition of claim 15 wherein the polypropylene is a propylene-olefin copolymer comprising up to 15 wt. % olefin based on the total weight of the propylene-olefin copolymer.
22 . The thermoplastic polyolefin composition of claim 15 wherein the polypropylene has a Melt Flow Index in the range of about 40 to about 1200 g/10 min measured at 230° C. with a 2.16 kg weight.
23 . The thermoplastic polyolefin composition of claim 15 wherein the styrenic elastomer comprises a saturated aliphatic hydrocarbon-styrene copolymer having a molecular styrene content below 50 wt. % based on the total weight of the styrenic elastomer.
24 . The thermoplastic polyolefin composition of claim 15 wherein the polypropylene or copolymer thereof is present in an amount of about 25-35 wt. %.
25 . The thermoplastic polyolefin composition of claim 15 wherein the styrenic elastomer is present in an amount of about 25-45 wt. %.
26 . The thermoplastic polyolefin composition of claim 15 wherein the hydrocarbon-based process oil is present in an amount of about 5-15 wt. %.
27 . The thermoplastic polyolefin composition of claim 15 wherein the composition has a zero shear viscosity of about 400-700 Pa·s at a processing temperature of 215° C.
28 . The thermoplastic polyolefin composition of claim 15 wherein the composition has a zero shear viscosity of about 450-600 Pa·s at a processing temperature of 215° C.
29 . A thermoplastic polyolefin composition suitable for slush mold processing, comprising a blend of, on the basis of 100 parts by weight:
about 20-50 wt. % polypropylene or copolymer thereof,
about 20-60 wt. % styrenic elastomer,
about 5-50 wt. % linear low density polyethylene, and
about 2-25 wt. % hydrocarbon-based process oil,
wherein the composition has a melt viscosity of about 300-900 Pa·s over a processing temperature range of 180-260° C.
30 . The thermoplastic polyolefin composition of claim 29 further comprising up to about 40 wt. % ethylene copolymer.
31 . The thermoplastic polyolefin composition of claim 29 further comprising up to about 5 wt. % polymer surface modifier.
32 . The thermoplastic polyolefin composition of claim 29 further comprising up to about 10 wt. % powder flow additive.
33 . The thermoplastic polyolefin composition of claim 32 wherein the powder flow additive is one of inorganic particulate, hydrated silicate, talc, or montmorillonite clay, or a combination thereof.
34 . The thermoplastic polyolefin composition of claim 29 further comprising about 1 wt. % to about 4 wt. % of a heat stabilizer or a light stabilizer, or a combination thereof.
35 . The thermoplastic polyolefin composition of claim 29 wherein the polypropylene is a propylene-olefin copolymer comprising up to 15 wt. % olefin based on the total weight of the propylene-olefin copolymer.
36 . The thermoplastic polyolefin composition of claim 29 wherein the polypropylene has a Melt Flow Index in the range of about 40 to about 1200 g/10 min measured at 230° C. with a 2.16 kg weight.
37 . The thermoplastic polyolefin composition of claim 29 wherein the styrenic elastomer is a hydrocarbon-styrene copolymer having a molecular styrene content below 50 wt. % based on the total weight of the styrenic elastomer, the balance being a saturated aliphatic hydrocarbon polymer or copolymer.
38 . The thermoplastic polyolefin composition of claim 29 wherein the polypropylene or copolymer thereof is present in an amount of about 25-35 wt. %.
39 . The thermoplastic polyolefin composition of claim 29 wherein the styrenic elastomer is present in an amount of about 25-45 wt. %.
40 . The thermoplastic polyolefin composition of claim 29 wherein the linear low density polyethylene is present in an amount of about 10-35 wt. %.
41 . The thermoplastic polyolefin composition of claim 29 wherein the hydrocarbon-based process oil is present in an amount of about 5-15 wt. %.
42 . The thermoplastic polyolefin composition of claim 29 wherein the composition has a zero shear viscosity of about 400-700 Pa·s at a processing temperature of 215° C.
43 . The thermoplastic polyolefin composition of claim 29 wherein the composition has a zero shear viscosity of about 450-600 Pa·s at a processing temperature of 215° C.
44 . A thermoplastic polyolefin composition suitable for slush mold processing, consisting essentially of a blend of, on the basis of 100 parts by weight:
about 25-35 wt. % polypropylene or copolymer thereof,
about 25-45 wt. % styrenic elastomer,
about 10-35 wt. % linear low density polyethylene,
about 5-15 wt. % hydrocarbon-based process oil,
up to about 40 wt. % ethylene copolymer,
up to about 5 wt. % polymer surface modifier,
up to about 10 wt. % powder flow additive,
up to about 4 wt. % of a heat stabilizer or a light stabilizer, or a combination thereof, and
up to about 2 wt. % color pigment,
wherein the composition has a zero shear viscosity of about 300-900 Pa·s over a processing temperature range of 180-260° C. and a zero shear viscosity of about 450-600 Pa·s at a processing temperature of 215° C.
45 . The thermoplastic polyolefin composition of claim 44 wherein the ethylene copolymer is present in an amount of about 15-25 wt. %.
46 . The thermoplastic polyolefin composition of claim 44 wherein the polymer surface modifier is present in an amount of about 0.3-2 wt. %.
47 . The thermoplastic polyolefin composition of claim 44 wherein the powder flow additive is present in an amount of about 3-7 wt. %.
48 . The thermoplastic polyolefin composition of claim 47 wherein the powder flow additive is one of inorganic particulate, hydrated silicate, talc, or montmorillonite clay, or a combination thereof.
49 . The thermoplastic polyolefin composition of claim 44 wherein the stabilizers are present in an amount of about 1 wt. % to about 4 wt. %.
50 . The thermoplastic polyolefin composition of claim 44 wherein the color pigment is present in an amount of about 1 wt. % to about 2 wt. %.
51 . The thermoplastic polyolefin composition of claim 44 wherein the polypropylene is a propylene-olefin copolymer comprising up to 15 wt. % olefin based on the total weight of the propylene-olefin copolymer.
52 . The thermoplastic polyolefin composition of claim 44 wherein the polypropylene has a Melt Flow Index in the range of about 40 to about 1200 g/10 min measured at 230° C. with a 2.16 kg weight.
53 . The thermoplastic polyolefin composition of claim 44 wherein the styrenic elastomer comprises a saturated aliphatic hydrocarbon-styrene copolymer having a molecular styrene content below 50 wt. % based on the total weight of the styrenic elastomer.
54 . A molded article made from the composition of claim 1 .
55 . A molded article made from the composition of claim 15 .
56 . A molded article made from the composition of claim 29 .
57 . A molded article made from the composition of claim 44.