Self-assembled propylene-based compositions and methods of production thereof

Patent metadata

Field	Value
Publication number	US-11034819-B2
Application number	US-201615387293-A
Country	US
Kind code	B2
Filing date	Dec 21, 2016
Priority date	Feb 24, 2016
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

Disclosed are self-assembled propylene-based bi-layer compositions having a skin layer comprising a propylene-based elastomer-toughened composition and a core layer comprising a propylene-based fiber-reinforced composition, wherein the propylene-based elastomer-toughened composition and propylene-based fiber-reinforced composition self-assemble upon mixing into the skin layer and the core layer. Processes for producing these self-assembled propylene-based compositions are also disclosed.

First claim

The invention claimed is:

1. A propylene-based bi-layer composition comprising:
a skin layer comprising 90 wt % or more of a propylene-based elastomer-toughened composition based on the weight of the skin layer, wherein the skin layer is from about 200 to about 300 microns thick; and
a core layer comprising 90 wt % or more of a propylene-based fiber-reinforced composition based on the weight of the core layer,
wherein the elastomer-toughened composition is formed from (i) a functionalized low molecular weight (LMW) propylene polymer having a number average molecular weight (Mn) within the range from 5,000 g/mol to 40,000 g/mol, wherein the LMW propylene polymer comprises a functional group selected from the group consisting of vinyl, vinylidene and combinations thereof, and (ii) at least one functionalized elastomer, wherein a functional chain of the low molecular weight propylene polymer is coupled to a functional chain of the at least one functionalized elastomer;
wherein the fiber-reinforced composition is formed from (i) a high molecular weight (HMW) propylene polymer having an Mn greater than 40,000 g/mol and (ii) reinforcing fibers,
wherein the weight concentration of the elastomer-toughened composition gradually decreases from a maximum concentration at the surface of the skin layer to a minimum concentration within the core layer,
wherein the elastomer-toughened composition and the fiber-reinforced composition self-assemble upon mixing into the skin layer and the core layer, and
wherein the thickness of the skin layer is from about 5% to about 25% of the total thickness of the propylene-based bi-layer composition.

2. The propylene-based bi-layer composition of claim 1 , wherein the elastomer-toughened composition and the fiber-reinforced composition self-assemble upon mixing into the skin layer and the core layer in 5 seconds or less.

3. The propylene-based bi-layer composition of claim 1 , wherein the elastomer-toughened composition is present in the propylene-based bi-layer composition within the range from 1-50 wt %, and wherein the fiber-reinforced composition is present in the propylene-based bi-layer composition within the range from 50-99 wt %.

4. The propylene-based bi-layer composition of claim 1 , wherein the elastomer-toughened composition has an elastomeric content within the range from 14-55 wt %, based on the weight of the elastomer-toughened composition.

5. The propylene-based bi-layer composition of claim 1 , wherein the LMW propylene polymer and/or the HMW propylene polymer comprises isotactic polypropylene (iPP).

6. The propylene-based bi-layer composition of claim 1 , wherein the LMW propylene polymer further comprises a functional group selected from the group consisting of amine, carboxylic acid, hydroxyl, aldehyde, and combinations thereof.

7. The propylene-based bi-layer composition of claim 1 , wherein the at least one elastomer is derivatized from a compound selected from the group consisting of polyolefin elastomers, ethylene-butene plastomers, ethylene-hexene plastomers, ethylene-octene plastomers, propylene-ethylene copolymers, propylene-hexene copolymers, ethylene-octene elastomers, acrylic based elastomers, diene rubbers, styrene-butadiene rubber, cis-butadiene rubber, natural rubber, hydrogenated styrene-butadiene (or isoprene) block copolymers, nitrile based elastomers, silicone based elastomers, and combinations thereof.

8. The propylene-based bi-layer composition of claim 1 , wherein the reinforcing fibers are surface treated.

9. The propylene-based bi-layer composition of claim 1 , wherein the reinforcing fibers are macrofibers selected from the group consisting of glass fibers, carbon fibers, polyester fibers, and mixtures thereof.

10. The propylene-based bi-layer composition of claim 1 , wherein the reinforcing fibers are microfibers selected from the group consisting of calcium metasilicate whiskers, magnesium oxysulfate whiskers, graphenes, and mixtures thereof.

11. The propylene-based bi-layer composition of claim 1 , wherein the reinforcing fibers are nanofibers selected from the group consisting of carbon nanofibers, carbon nanotubes, aluminosilicate nanotubes, and mixtures thereof.

12. The propylene-based bi-layer composition of claim 1 , wherein the thickness of the skin layer is from at least 10% to about 20% of the total thickness of the propylene-based bi-layer composition.

13. The propylene-based bi-layer composition of claim 1 , wherein the composition has an impact resistance of at least 2.15 kJ/m 2 and a Young's modulus of at least 1,500 MPa.

14. The propylene-based bi-layer composition of claim 1 , wherein the elastomer-toughened composition is present in the propylene-based bi-layer composition within the range from 7.5-45 wt %, and wherein the fiber-reinforced composition is present in the propylene-based bi-layer composition within the range from 92.5-55 wt %.

15. The propylene-based bi-layer composition of claim 1 , wherein the fiber-reinforced composition has a reinforcing fiber content within the range from 14 to 60 wt % based on the weight of the fiber-reinforced composition.

16. The propylene-based bi-layer composition of claim 1 , wherein the elastomer-toughened composition has an elastomeric content within the range from 25 to 45 wt % based on the weight of the elastomer-toughened composition.

17. The propylene-based bi-layer composition of claim 1 , wherein the fiber-reinforced composition has a reinforcing fiber content from 25 to 45 wt % based on the weight of the fiber-reinforced composition.

18. The propylene-based bi-layer composition of claim 1 , wherein the fiber-reinforced composition is formed from (i) a high molecular weight (HMW) propylene polymer having an Mn from 50,000 to 500,000 g/mol.

19. The propylene-based bi-layer composition of claim 1 , wherein the composition comprises:
7.5 to 45 wt % of the propylene-based elastomer toughened composition, based on the total weight of the propylene-based bi-layer composition; and
55 to 92.5 wt % of the propylene-based fiber-reinforced composition, based on the total weight of the propylene-based bi-layer composition.

20. The propylene-based bi-layer composition of claim 1 , wherein the skin layer is from 15 to 25% of the total thickness of the propylene-based bi-layer composition.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Tsou Andy H
• Hagadorn John R
• Buchholz Viktor
• Jiang Peijun

Classifications

• C08K7/02 Primary

  Fibres or whiskers · CPC title

• C08J5/04

  Reinforcing macromolecular compounds with loose or coherent fibrous material · CPC title

• C08J2451/06

  grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond · CPC title

• C08F8/46

  Reaction with unsaturated dicarboxylic acids or anhydrides thereof, e.g. maleinisation · CPC title

• C08J2323/36

  by reaction with nitrogen-containing compounds, e.g. by nitration · CPC title