Thermoplastic articles and processes for making the same using an improved masterbatch

• US 20080058455A1
• Filed: 06/25/2007
• Published: 03/06/2008
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies, Inc. (Dow, Inc.)
• Inventors: Wevers, Ronald, Krabbenborg, Franciscus, Houg, Jacobus, Ballot, Michael
• Granted Patent: US 7,732,521 B2
• Time in Patent Office: Days
• US Class Current: 524/451
• CPC Class Codes: C08J 2323/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08J 2423/00 Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
• CPC Class Codes: C08J 3/226 using a polymer as a carrier
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof

Abstract

The present invention is directed to improved processes for making plastic articles, and articles made therefrom. In a broad aspect, the invention is directed to improved processes and articles made therefrom, that include the steps of providing as separate materials a first material that includes a polyolefin, a second material including an admixture of from about 45 to 85 wt. % of the total admixture of at least one particulated mineral filler; and from about 15 to 55 wt. % of the total admixture of at least a second polyolefin having a melt index greater than about 150 g/10 min at 190° C./2.16 kg, as measured per ISO 1133 (condition D); applying a shear force to form a molten blend; shaping the molten blend and solidifying the molten blend.

Claims

1. A process for making a shaped article, comprising the steps of:

a) providing as separate materials a first material that includes a first polyolefin, and a second material including an admixture of;

(i) from about 45 to 85 wt. % of the total admixture of at least one particulated mineral filler; and

(ii) from about 15 to 55 wt. % of the total admixture of at least a second polyolefin having a melt index greater than about 150 g/10 min at 190°

C./2.16 kg, as measured per ISO 1133 (condition D);

b) applying a shear force to the first and second materials, while the materials are at an elevated temperature for blending the materials to form a molten blend;

c) shaping the molten blend; and

d) solidifying the molten blend, wherein the process is substantially free of a step of compounding together the first and second materials prior to the blending step.

2. The process of claim 1, wherein the first polyolefin of the first material comprises a thermoplastic polyolefin.

3. The process of claim 2, wherein the process is substantially free of a step of compounding together the first, second and any optional other materials prior to the blending step.

4. The process of claim 3, further comprising a step of providing a color concentrate for achieving a desired color in the resulting shaped article.

5. The process of claim 2, further comprising a step of providing regrind for blending with at least the first and second materials.

6. The process of claim 2, wherein the step of shaping the molten blend includes injection molding the molten blend into a cavity of a molding tool.

7. The process of claim 2, wherein the thermoplastic polyolefin of the first material includes a polypropylene impact copolymer characterized by a melt flow rate of less than about 70 g/10 min (ISO 1133 condition M at 230°

C., 2.16 kg), and containing greater than about 8 wt % (of the first material) of ethylene, having greater than about 40 % crystallinity, or any combination thereof.

8. The process of claim 2, wherein the providing step includes dry blending the first and second materials.

9. The process of claim 2, wherein at least the first and the second materials are provided as pellets.

10. The process of claim 9, wherein at least about 50% by weight of both of the pellets of the first material and the pellets of the second material are substantially the same volume.

11. The process of claim 10, further comprising admixing with the first material and the second material at least one additive selected from a heat stabilizer, a UV stabilizer, a mold release agent, a nucleator, a lubricant, a slip agent, a colorant or any combination thereof.

12. The process of any of claim 2, wherein the particulated mineral filler is talc.

13. The process of claim 2, wherein the particulated mineral filler is present in an amount of about 70% by weight the total admixture.

14. The process of claim 12, wherein the second polyolefin includes an ethylene-octene copolymer.

15. The process of claim 14, wherein the first polyolefin includes greater than about 8 wt % (by weight of the first material) of ethylene.

16. The process of claim 15, wherein the median particle diameter of the talc is less than about 3 microns.

17. The process of claim 16, wherein the average volume of the particles of the second material is larger than the average volume of the particle size of the first material.

18. The process of claim 1, wherein the second polyolefin is compatible with an elastomeric component of the first polyolefin.

19. The process of any of claim 2, wherein particles of the second material are coated or partially coated with a mineral filler or a micronized polymer.

20. A kit for use in the process of claim 1, wherein the kit includes in separate packages:

(i) a first polyolefin;

(ii) at least one particulated mineral filler; and

(iii) a second polyolefin having a melt index greater than about 150 g/10 min at 190°

C./2.16 kg, as measured per ISO 1133 (condition D).