Compositions of ethylene/alpha-olefin multi-block interpolymer for elastic films and laminates

• US 8,273,068 B2
• Filed: 01/14/2008
• Issued: 09/25/2012
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Chang, Andy C., Hoenig, Stephen M., Cheung, Yunwa W., Moldovan, Daniel G., Liang, Wenbin, Diehl, Charles F.
• Primary Examiner(s): HAND, MELANIE JO
• Application Number:
  US12/013,668
• Publication Number:
  US 20080177242A1
• Time in Patent Office: 1,716 Days
• Field of Search: 525/232, 442/370, 442/401, 604/385.22, 604/367, 604/368
• US Class Current: 604/385.22
• CPC Class Codes: A61F 13/4902 characterised by the elastic material
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2307/306 Resistant to heat
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 2307/724 Permeability to gases, adsorption
• CPC Class Codes: B32B 2309/14 Velocity, e.g. feed speeds
• CPC Class Codes: B32B 2432/00 Cleaning articles, e.g. mops, wipes personal care B32B2555/00
• CPC Class Codes: B32B 25/10 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 25/14 comprising synthetic rubber copolymers B32B25/18 and B32B25/20 take precedence
• CPC Class Codes: B32B 2535/00 Medical equipment, e.g. bandage, prostheses, catheter medical patches B32B2556/00
• CPC Class Codes: B32B 2555/00 Personal care
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/205 the fillers creating voids or cavities, e.g. by stretching
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 5/022 Non-woven fabric
• CPC Class Codes: C08F 210/14 Monomers containing five or more carbon atoms
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/03 Narrow molecular weight distribution, i.e. Mw/Mn < 3
• CPC Class Codes: C08F 2500/11 : Melt tension or melt strength
• CPC Class Codes: C08F 2500/12 : Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/20 : Activation energy or enthalpy
• CPC Class Codes: C08F 2500/21 : Rubbery or elastomeric properties
• CPC Class Codes: C08F 297/08 : polymerising mono-olefins
• CPC Class Codes: C08F 297/083 : the monomers being ethylene or propylene
• CPC Class Codes: C08J 2323/08 : Copolymers of ethene C08J2323/16 takes precedence
• CPC Class Codes: C08J 5/18 : Manufacture of films or sheets
• CPC Class Codes: C08L 23/0815 : Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 2666/02 : Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 : Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/24 : Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/00 : 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 Class Codes: C08L 53/005 : Modified block copolymers
• CPC Class Codes: C08L 53/02 : of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 53/025 : modified
• CPC Class Codes: C09D 153/00 : Coating compositions based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 153/02 : Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C09D 153/025 : modified
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 442/20 : Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/647 : Including a foamed layer or component
• CPC Class Codes: Y10T 442/681 : Spun-bonded nonwoven fabric

Abstract

This invention relates to polyolefin compositions. In particular, the invention pertains to elastic polymer compositions that can be more easily processed on cast film lines, extrusion lamination or coating lines. The compositions of the present invention preferably comprise an elastomeric polyolefin resin and a high pressure low density type resin.

Claims

1. A laminate comprising an elastic breathable film comprising:

at least one linear ethylene/α

-olefin interpolymer elastomer, wherein the ethylene/α

-olefin interpolymer elastomer comprises hard blocks comprising less than 2 wt % comonomer; and

soft blocks; and

(a) has a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship;

Tm>

−

2002.9+4538.5(d)−

2422.2(d)²;

or

(b) has a Mw/Mn from about 1.7 to about 3.5, and is characterized by a heat of fusion, Δ

H in J/g, and a delta quantity, Δ

T, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of Δ

T and Δ

H have the following relationships;

Δ

T>

−

0.1299(Δ

H)+62.81 for Δ

H greater than zero and up to 130 J/g,

Δ

T≧

48°

C. for Δ

H greater than 130 J/g,

wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30°

C.;

or

(c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α

-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α

-olefin interpolymer is substantially free of a cross-linked phase;

Re>

1481−

1629(d);

or

(d) has a molecular fraction which elutes between 40°

C. and 130°

C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α

-olefin interpolymer;

(e) has a storage modulus at 25°

C., G′

(25°

C.), and a storage modulus at 100°

C., G′

(100°

C.), wherein the ratio of G′

(25°

C.) to G′

(100°

C.) is in the range of about 1;

1 to about 9;

1;

or

(f) has a molecular fraction which elutes between 40°

C. and 130°

C. when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a molecular weight distribution, Mw/Mn, greater than about 1.3;

or

(g) has an average block index greater than zero and up to about 1.0 and a molecular weight distribution, Mw/Mn, greater than about 1.3; and

optionally,

a styrenic block copolymer, or a combination thereof

wherein the ethylene/α

-olefin interpolymer has a density of from about 0.85 to about 0.885 g/cc; and

,

wherein the film has microvoids.

2. The laminate of claim 1 wherein the film comprises a styrenic block copolymer wherein the styrenic block copolymer is selected from the group consisting of styrene-isoprene-styrene polymers, styrene-ethylene- butadiene-styrene polymers, styrene-butadiene-styrene polymers, styrene-ethylenepropylene-styrene, styrene-ethylenepropylene-styrene-ethylenepropylene, hydrogenated polybutadiene polymers, hydrogenated poly isoprene/butadiene polymers and combinations thereof.

3. The laminate of claim 1 wherein the film has a breathability greater than 100 g/m²/24 hours.

4. A fabricated article comprising the laminate of claim 1 wherein said fabricated article is selected from the group consisting of adult incontinence articles, feminine hygiene articles, infant care articles, surgical gowns, medical drapes, household cleaning articles, expandable food covers, protective clothing, bandages and personal care articles.

5. The laminate of claim 1 further comprising a nonwoven layer.

6. The laminate of claim 5 wherein the laminate has a hydrohead value of at least about 10 centimeters as measured using the Hydrostatic Pressure Test performed according to Method 5514—

—

Federal Test Methods Standard No. 191A.

7. The laminate of claim 5 wherein the nonwoven layer comprises fibers selected from the group consisting of melt blown, spunbond, carded staple fibers, spunlaced staple fibers, and air laid staple fibers.

8. The laminate of claim 1 wherein the film further comprises a filler and a higher crystalline linear polymer.

9. The laminate of claim 8, wherein the film comprises between about 25 and 70 weight percent filler, between about 5 and 30 weight percent higher crystalline linear polymer, and between about 15 and 60 weight percent elastomer.

10. The laminate of claim 8 wherein the filler is selected from the group consisting of calcium carbonate, clay, silica, alumina, barium sulfate, sodium carbonate, talc, magnesium sulfate, titanium dioxide, zeolites, aluminum sulfate, cellulose-type powders, diatomaceous earth, gypsum, magnesium sulfate, magnesium carbonate, barium carbonate, kaolin, mica, carbon, calcium oxide, magnesium oxide, aluminum hydroxide, pulp powder, wood powder, cellulose derivatives, polymeric particles, chitin and chitin derivatives and combinations thereof.

11. The laminate of claim 8 wherein the film further comprises a styrenic block copolymer wherein the styrenic block copolymer is selected from the group consisting of styrene-isoprene-styrene polymers, styrene-ethylene-butadiene-styrene polymers, styrene-butadiene-styrene polymers, styrene-ethylenepropylene-styrene, styrene-ethylenepropylene-styrene-ethylenepropylene, hydrogenated polybutadiene, hydrogenated poly isoprene/butadiene polymers and combinations thereof.

12. The laminate of claim 8 wherein the film has a breathability greater than 100 g/m²/24 hours.

13. A fabricated article comprising the laminate of claim 8 wherein said fabricated article is selected from the group consisting of adult incontinence articles, feminine hygiene articles, infant care articles, surgical gowns, medical drapes, household cleaning articles, expandable food covers, protective clothing, bandages and personal care articles.

14. The laminate of claim 8 further comprising a nonwoven layer.

15. The laminate of claim 8 wherein the laminate has a hydrohead value of at least about 10 centimeters as measured using the Hydrostatic Pressure Test performed according to Method 5514—

—

Federal Test Methods Standard No. 191A.

16. The laminate of claim 14 wherein the nonwoven layer comprises fibers selected from the group consisting of melt blown, spunbond, carded staple fibers, spunlaced staple fibers, and air laid staple fibers.

17. A fabricated article comprising the laminate of claim 14 wherein said fabricated article is selected from the group consisting of adult incontinence articles, feminine hygiene articles, infant care articles, surgical gowns, medical drapes, household cleaning articles, expandable food covers, protective clothing, bandages and personal care articles.