# US 2014/0154448 A1 · Multilayer film with high tear propagation resistance and low shrinkage

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- Number: US 2014/0154448 A1
- Document ID: US20140154448A1
- Status: Published application
- Kind: A1
- Application number: 14/131,967
- Filed: 2012-07-06
- Published: 2014-06-05
- Earliest claimed: 2011-07-20
- Assignees: Huhtamaki Films Germany GmbH & Co. KG
- Inventors: Heinz Engelhard
- Web page: https://patentgrep.com/patent/US20140154448A1

## CPC

- C09J 7/403: {characterised by the structure of the release feature}
- B32B 3/263: {characterised by a layer having non-uniform thickness}
- B32B 5/18: characterised by features of a layer {of} foamed material
- B32B 7/06: permitting easy separation
- B32B 27/08: of synthetic resin
- B32B 27/308: {comprising acrylic (co)polymers}
- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- B32B 33/00: Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
- E04D 5/10: by making use of compounded or laminated materials, e.g. metal foils or plastic films coated with bitumen
- B32B 2250/03: 3 layers
- B32B 2250/246: All polymers belonging to those covered by groups B32B27/32 and B32B27/30
- B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
- B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer
- B32B 2255/26: Polymeric coating
- B32B 2307/5825: Tear resistant
- B32B 2307/734: Dimensional stability
- B32B 2307/748: Releasability
- B32B 2419/06: Roofs, roof membranes
- Y10T 428/1452: Polymer derived only from ethylenically unsaturated monomer
- Y10T 428/24355: Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T 428/2495: Thickness [relative or absolute]
- Y10T 428/249982: With component specified as adhesive or bonding agent
- Y10T 428/249993: Hydrocarbon polymer
- Y10T 428/31663: As siloxane, silicone or silane
- Y10T 428/31913: Monoolefin polymer
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- E04D: ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS (coverings of outer walls by plaster or other porous material E04F13/00)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Multilayer film with high tear propagation resistance of at least 300 mN for a total layer thickness of 45 μm, a shrinkage of ≦1% at 120° C. and release properties, comprising a layer (a) formed of at least one propylene copolymer and optionally at least one olefin homopolymer, at least one internal layer (b) formed of at least one olefin/alkyl (meth)acrylate copolymer, a layer (c) formed of at least one propylene copolymer and optionally at least one olefin homopolymer with optional adhesion layers (d) and (e) arranged between layers (a) and (b), and between layers (b) and (c) respectively.

## Claims

### Claim 1

A multilayer film with a tear propagation resistance of at least 300 mN measured by the Elmendorf method (ISO 6383-2) on a multilayer film of total thickness 45 μm and with % shrinkage in accordance with DIN 53377 for 1 min of residence time in the oil bath at 120° C. (in both MD and CD) with release properties, comprising
(a) a layer formed of at least propylene copolymer and optionally at least one olefin homopolymer
(b) at least one internal layer formed of at least one olefin/alkyl (meth)acrylate copolymer
(c) a layer formed of at least one propylene copolymer and optionally at least one olefin homopolymer and
optionally a layer (d) arranged between the layer (a) and the layer (b) and/or a layer (e) arranged between the layer (b) and the layer (c), as an adhesion-promoter layer, wherein at least one of the surface layers of the multilayer film is provided with release properties.

### Claim 2 (depends on 1)

The multilayer film as claimed in claim 1, wherein the layer (a) and the layer (c) exhibit an identical layer structure, and optionally an identical layer thickness and/or an identical composition of the polymer components.

### Claim 3 (depends on 1)

The multilayer film as claimed in claim 1, wherein the layer (a) and the layer (c), being identical or different from one another, comprise at least one copolymer of propylene and of an α,β-unsaturated olefin.

### Claim 4 (depends on 1)

The multilayer film as claimed in claim 1, wherein the layer (a) and/or layer (c) is/are based on at least one propylene-ethylene copolymer having at most 15% by weight, based in each case on the total weight of the propylene/ethylene copolymer, of ethylene units.

### Claim 5 (depends on 1)

The multilayer film as claimed in claim 1, wherein the layer (a) and/or layer (c) comprises at most 15% by weight, based on the total weight of the layer (a) or layer (c), respectively, of at least one propylene homopolymer or ethylene homopolymer, whereby the polymer components of the layer (a) and the layer (c) in each case always must be 100% by weight.

### Claim 6 (depends on 1)

The multilayer film as claimed in claim 1, wherein the layer (b) is formed of at least one α,β-unsaturated olefin having from 1 to 8 carbon atoms and a C1-C6-alkyl (meth)acrylate.

### Claim 7 (depends on 1)

The multilayer film as claimed in claim 1, wherein the layer (d) and/or layer (e) is based in each case on at least one modified, thermoplastic olefin homo- or copolymer.

### Claim 8 (depends on 1)

The multilayer film as claimed in claim 1, produced by a blown-film-co-extrusion process.

### Claim 9 (depends on 1)

The multilayer film as claimed in claim 1, wherein at least one surface layer of the multilayer film has, in order to provide release properties, a cured polysiloxane coating optionally with an embossed surface topography or an unembossed, uneven surface structure due to foaming.

### Claim 10 (depends on 1)

A removable release and/or protective film comprising the multilayer film of claim 1.

### Claim 11 (depends on 10)

Adhesive or self-adhesive products comprising the removable release and/or protective film of claim 10.

### Claim 12 (depends on 11)

A self-adhesive product of claim 11, wherein said product is a tightening composition, tightening an adhesive tape or a label.

### Claim 13 (depends on 12)

The self-adhesive product of claim 12, wherein the tightening composition is a bitumen composition for a waterproof sheeting material.

### Claim 14 (depends on 1)

A waterproof sheeting material with a multilayer film as claimed in claim 1, as removable release and/or protective film.