Clarified polypropylene for long term color performance

Patent metadata

Field	Value
Publication number	US-11535733-B2
Application number	US-202016802750-A
Country	US
Kind code	B2
Filing date	Feb 27, 2020
Priority date	Feb 28, 2019
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

Color-stable rheology controlled polyolefin compositions and methods of making are described. A color-stable rheology controlled polyolefin composition can include a controlled rheology grade thermoplastic polyolefin, and an effective amount of a trisamide-based compound that imparts color-stability to the composition. The color-stable solid-state thermoplastic polyolefin composition can have a Hunter b value color change (Δb) rate of ≤0.03/day when stored at 93° C. for 50 days.

First claim

The invention claimed is:

1. A color-stable solid-state thermoplastic polyolefin composition comprising:
(a) a vis-broken thermoplastic polyolefin; and
(b) a trisamide-based compound,
(c) a hindered amine light stabilizer;
(d) a glycerol monostearate;
(e) an organic peroxide;
(f) a metal stearate; and
(g) a phosphite-based antioxidant;
wherein the color-stable solid-state thermoplastic polyolefin composition has a Hunter b value color change (Δb) rate of ≤0.03/day when stored at 93° C. for 50 days, wherein the color-stable solid-state thermoplastic polyolefin composition has a melt flow rate (MFR) as measured by ASTM D1238 ranging from 5 dg/min to 150 dg/min.

2. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the vis-broken thermoplastic polyolefin is polypropylene.

3. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the trisamide-based compound is a trisamide benzene compound or a trisamide propane compound.

4. The color-stable solid-state thermoplastic polyolefin composition of claim 3 , wherein the trisamide-based compound is a trisamide benzene compound having the following structure A or a trisamide propane compound having the following structure B:

5. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the color-stable solid-state thermoplastic polyolefin composition has Δb rate of ≤0.02/day when stored at 93° C. for 50 days.

6. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the color-stable solid-state thermoplastic polyolefin composition has Δb rate of ≤0.035/day when stored at 93° C. for 100 days.

7. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , comprising:
at least 95 wt. %, of the thermoplastic polyolefin; and
0.001 wt. % to 1 wt. %, of the trisamide-based compound.

8. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the composition is free of a phenolic-based antioxidant.

9. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the color-stable solid-state thermoplastic polyolefin composition has Δb rate of ≤0.02/day when stored at 93° C. for 50 days.

10. The color-stable solid-state thermoplastic polyolefin composition of claim 8 , wherein the color-stable solid-state thermoplastic polyolefin composition has Δb rate of ≤0.02/day when stored at 93° C. for 100 days.

11. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the composition is free of a sorbitol-based clarifier.

12. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the composition is transparent.

13. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , comprising at least 90 wt. % of the thermoplastic polyolefin, or a blend of thermoplastic polyolefins.

14. A method of making the color-stable solid-state thermoplastic polyolefin composition of claim 1 , the method comprising adding an effective amount of a trisamide-based compound to a controlled rheology grade thermoplastic polyolefin composition such that the solid-state thermoplastic polyolefin composition has a Hunter b value color change (Δb) rate of ≤0.03/day when stored at 93° C. for 50 days.

15. The method of claim 14 , wherein the controlled rheology grade thermoplastic polyolefin composition is a controlled rheology grade polypropylene composition, and the trisamide-based compound is a trisamide benzene compound, or having the following structure A, or a trisamide propane compound, or having the following structure B:

16. The color-stable solid-state thermoplastic polyolefin composition of claim 1 , wherein the thermoplastic polyolefin has
a number average molecular weight (Mn) as measured by gel permeation chromatography (GPC) ranging from 15,000 to 75,000 Daltons;
a weight average molecular weight (Mw) as measured by GPC ranging from 100,000 to 300,000 Daltons; and
a polydispersity index (PDI=Mw/Mn) ranging from 3.0 to 9.0.

Assignees

• Fina Technology

Inventors

• Mcleod Michael
• Ashbaugh John
• Mayhall Marc

Classifications

• C08K5/09

  Carboxylic acids; Metal salts thereof; Anhydrides thereof · CPC title

• C08K5/14

  Peroxides · CPC title

• C08L23/12 Primary

  Polypropene · CPC title

• C08K5/098

  Metal salts of carboxylic acids · CPC title

• C08K5/20 Primary

  Carboxylic acid amides · CPC title