Bleed resistant, oil-extended olefin block copolymer composition with precipitated silica

Patent metadata

Field	Value
Publication number	US-9034972-B2
Application number	US-201113997954-A
Country	US
Kind code	B2
Filing date	Dec 14, 2011
Priority date	Dec 30, 2010
Publication date	May 19, 2015
Grant date	May 19, 2015

Abstract

Disclosed are oil-extended olefin block copolymer compositions with precipitated silica. The precipitated silica reduces oil-bleed while maintaining composition softness.

First claim

What is claimed is:

1. An oil-extended olefin block copolymer composition comprising:
from 30 wt % to 40 wt % of an ethylene/α-olefin multi-block copolymer consisting of ethylene monomer and a straight-chain or branched, non-conjugated α-olefin comonomer with 3 to 30 carbon atoms;
from 45 wt % to 55 wt % of an oil; and
from 10 wt % to 30 wt % of a sole filler that is a synthetic precipitated silica and the composition has a normalized oil-bleed index of less than 20 after 1 week at 23° C., and a Shore A hardness from about 5 to about 50.

2. The composition of claim 1 wherein the olefin block copolymer has a density from about 0.85 g/cc to about 0.88 g/cc.

3. The composition of claim 1 comprising an oil/precipitated silica pre-mix.

4. The composition of claim 3 wherein the pre-mix comprises from about 60 wt % to about 80 wt % oil and from about 40 wt % to about 20 wt % precipitated silica.

5. The composition of claim 1 having a normalized oil-bleed index (NOBI) of less than 30 after 3 weeks at 23° C.

6. An oil-extended olefin block copolymer composition comprising:
from 10 wt % to 40 wt % of an ethylene/α-olefin multi-block copolymer consisting of ethylene monomer and a straight-chain or branched, non-conjugated α-olefin comonomer with 3 to 30 carbon atoms;
from 5 wt % to 20 wt % of a propylene-based polymer;
from 20 wt % to 60 wt % of an oil; and
5 wt % to 25 wt % of a sole filler that is a synthetic precipitated silica; and
the composition has a normalized oil-bleed index of less than 20 after 1 week at 23° C., and a Shore A hardness from 5 to 50.

7. The composition of claim 6 wherein the propylene-based polymer is a propylene homopolymer.

8. The composition of claim 1 wherein the synthetic precipitated silica is exclusive of silica gel, quartz silica, and fumed silica.

9. The composition of claim 6 wherein the synthetic precipitated silica is exclusive of silica gel, quartz silica, and fumed silica.

10. The composition of claim 6 having a normalized oil-bleed index of less than 30 after 3 weeks at 23° C.

Assignees

• Johnston Robert T
• Batra Ashish
• Laakso Jr Raymond L
• Liang Wenbin
• Dow Global Technologies Llc

Inventors

• Johnston Robert T
• Batra Ashish
• Laakso Jr Raymond L
• Liang Wenbin

Classifications

• C08K5/103

  with polyalcohols · CPC title

• C08K3/36

  Silica · CPC title

• C08L53/00 Primary

  Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers · CPC title

• C08L2666/02

  Organic macromolecular compounds, natural resins, waxes or and bituminous materials · CPC title

• C08L23/0807

  with unsaturated hydrocarbons only containing four or more carbon atoms · CPC title