Soft polymer compositions having improved high temperature properties

• US 20070049682A1
• Filed: 08/18/2006
• Published: 03/01/2007
• Est. Priority Date: 09/01/2005
• Status: Active Grant

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Walsh, David
• Granted Patent: US 7,655,731 B2
• Time in Patent Office: Days
• US Class Current: 524/502
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2307/536 Hardness
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/546 Flexural strength; Flexion stiffness
• CPC Class Codes: B32B 2307/584 Scratch resistance
• CPC Class Codes: B32B 2307/704 Crystalline
• CPC Class Codes: B32B 2307/71 Resistive to light or to UV
• CPC Class Codes: B32B 2307/714 Inert, i.e. inert to chemical degradation, corrosion
• CPC Class Codes: B32B 2509/00 Household appliances
• CPC Class Codes: B32B 2605/08 Cars
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: C08L 23/0869 Acids or derivatives thereof
• CPC Class Codes: C08L 23/0876 Neutralised polymers, i.e. ionomers
• 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

Disclosed are soft polymer compositions comprising an ethylene/alkyl (meth)acrylate copolymer and a crystalline polyolefin, such as polypropylene homopolymers or polypropylene copolymers, wherein the ethylene/alkyl (meth)acrylate copolymer has a higher melt viscosity than the polyolefin. Also disclosed are such compositions modified by materials that improve the scratch-and-mar properties of the blends, the preparation and use of these compositions in such processes as extrusion and injection molding, and articles made from these compositions.

Claims

1. A composition comprising a blend and optionally a first component, a second component, or both wherein

the composition has a Shore D hardness of less than 50;

the blend comprises 20 to 50 weight % of at least one crystalline polyolefin and 50 to 80 weight % of at least one ethylene/alkyl (meth)acrylate copolymer, the ethylene/alkyl (meth)acrylate copolymer has a higher melt viscosity than the polyolefin;

the first component is capable of improving the scratch-and-mar properties of the composition; and

the second component includes plasticizer, stabilizer, antioxidant, UV absorber, antistatic agent, dye, pigment or other coloring agent, fluorescent whitening agent, inorganic filler, delustrant, terminating agent, fire-retardant, lubricant, reinforcing agent, foaming or blowing agent, processing aid, slip additive, antiblock agent, release agent, tackifying resin, or combinations of two or more thereof.

2. The composition of claim 1 wherein the blend comprises 25 to 45 weight % of at least one polypropylene homopolymer or polypropylene copolymer and 55 to 75 weight % of at least one ethylene/alkyl acrylate copolymer;

the ethylene/alkyl acrylate copolymer has a higher melt viscosity than the polypropylene; and

the ratio of the melt viscosity of the ethylene/alkyl acrylate copolymer to the melt viscosity of the propylene is greater than 1.25;

1.

3. The composition of claim 2 wherein the ratio of the melt viscosity of the ethylene/alkyl acrylate copolymer to the melt viscosity of the propylene is greater than 1.5.

4. The composition of claim 2 wherein the composition has a Vicat temperature of at least 60°

C.

5. The composition of claim 3 wherein the composition has a Vicat temperature of at least 65°

C.

6. The composition of claim 2 wherein the alkyl (meth)acrylate is present in the ethylene/alkyl (meth)acrylate copolymer in a range from about 5 to about 40 weight %.

7. The composition of claim 4 wherein the alkyl (meth)acrylate is present in said ethylene/alkyl (meth)acrylate copolymer in a range from about 10 to about 35 weight %.

8. The composition of claim 5 wherein the alkyl (meth)acrylate is present in said ethylene/alkyl (meth)acrylate copolymer in a range from about 10 to about 35 weight %.

9. The composition of claim 6 wherein the alkyl (meth)acrylate is methyl acrylate, ethyl acrylate, butyl acrylate, or combinations of two or more thereof.

10. The composition of claim 8 wherein the alkyl (meth)acrylate is methyl acrylate, ethyl acrylate, butyl acrylate, or combinations of two or more thereof.

11. The composition of claim 9 wherein the ethylene/alkyl (meth)acrylate is a tubular reactor produced copolymer.

12. The composition of claim 10 wherein the ethylene/alkyl (meth)acrylate is a tubular reactor produced copolymer.

13. A molded article made from a composition and having a height of 6.35 mm and having a 16.5 psi (0.116 MPa) load at the mid-point of a 50-mm span in a 3-point bending device at a heating rate of 2°

C./min wherein the composition is as recited in claim 2 and the article deflects to 500 μ

m at temperatures greater than 60°

C.

14. The molded article of claim 13 having a thickness of about 3 mm and being heated in a chamber at a rate of 5°

C./min wherein the article is penetrated by a probe of 0.89 mm contact diameter with an applied force of one Newton to a depth of 900 μ

m at temperatures greater than 105, greater than 120, or greater than 140°

C.

15. An article comprising or produced from a composition wherein the article includes films, multilayer laminates, extruded sheets, or coated fabrics and the composition is as recited in claim 1.

16. The article of claim 15 wherein the article is shaped by injection molding, extrusion molding, profile-extrusion, or thermoforming;

the blend comprises 25 to 45 weight % of at least one polypropylene homopolymer or polypropylene copolymer and 55 to 75 weight % of at least one ethylene/alkyl acrylate copolymer;

the ethylene/alkyl acrylate copolymer has a higher melt viscosity than the polypropylene; and

the ratio of the melt viscosity of the ethylene/alkyl acrylate copolymer to the melt viscosity of the propylene is greater than 1.25;

1.

17. The article of claim 15 wherein the ratio of the melt viscosity of the ethylene/alkyl acrylate copolymer to the melt viscosity of the propylene is greater than 1.5.

18. The article of claim 15 wherein the composition has a Vicat temperature of at least 65°

C.

19. The article of claim 15 wherein the alkyl (meth)acrylate is present in said ethylene/alkyl (meth)acrylate copolymer in a range from about 10 to about 35 weight %.

20. The article of claim 15 wherein the ethylene/alkyl (meth)acrylate is a tubular reactor produced copolymer.