Hoechst Aktiengesellschaft

Angela Speith

Ursula Murschall

Gunter Schloegl

Herbert Peiffer

A process for the production of a transparent, printable, biaxially oriented polyolefin multilayer film which can be sealed on both sides including (i) coextruding through a flat die melts corresponding to the individual layers of the film, (ii) taking off and cooling to consolidate the resulting film, via a take-off roll, (iii) biaxially stretching the consolidated film, (iv) thermofixing the biaxially stretched film, and (v) covering top layer C with a non-cohesive layer of polydialkylsiloxane.

Process for the production of a transparent polyolefin multilayer film

A process for the production of a biaxially-oriented multilayer polypropylene film having a silk-matt finish includes coextruding melts corresponding to the individual layers of the film through a flat-film die; taking off the coextruded film over a take-off roll having a temperature between about 40 and about 100.degree. C.; biaxially stretching the film; thermofixing, and optionally corona-treating, the biaxially-stretched film; and winding up the thermofixed and optionally corona-treated film.

Process for the production of biaxially-oriented multilayer polyolefin

A multilayer polypropylene film is disclosed that has at least one base layer containing polypropylene and at least one outer layer containing a mixture of two mixture components I and II. Mixture component I is essentially a polypropylene homopolymer or a copolymer of ethylene and propylene or ethylene and butylene or propylene and butylene or ethylene and another .alpha.-olefin having 5 to 10 carbon atoms or propylene and another .alpha.-olefin having 5 to 10 carbon atoms or a terpolymer of ethylene and propylene and butylene or ethylene and propylene and another .alpha.-olefin having 5 to 10 carbon atoms or a mixture of two or more of said homopolymers, copolymers and terpolymers or a blend of two or more of said homopolymers, copolymers and terpolymers, if desired mixed with one or more of said homopolymers, copolymers and terpolymers. Mixture component II is essentially an HDPE or a blend of two blend components A and B. Blend component A is essentially an HDPE. Blend component B is essentially a polypropylene homopolymer or a copolymer of ethylene and propylene or ethylene and butylene or propylene and butylene or ethylene and another .alpha.-olefin having 5 to 10 carbon atoms or propylene and another .alpha.-olefin having 5 to 10 carbon atoms or a terpolymer of ethylene and propylene and butylene or ethylene and propylene and another .alpha.-olefin having 5 to 10 carbon atoms or a mixture of two or more of said homopolymers, copolymers and terpolymers or a blend of two or more of said homopolymers, copolymers and terpolymers. The film has a silk-matt finish.

Biaxially-oriented multilayer polyolefin film with a silk-matt finish,

A transparent, printable, biaxially orientated polyolefin multilayer film which can be sealed on both sides, having a base layer B and different top layers A and C located on both sides thereof in accordance with a layer build-up of ABC is provided. The base layer B contains a peroxidically degraded polypropylene polymer having a degradation factor in the range from about 3 to about 10. Top layer A contains a polymer mixture of two or more of the following co- and/or terpolymers: a copolymer of ethylene and propylene or ethylene and butylene or propylene and butylene or ethylene and another .alpha.-olefin having 5 to 10 carbon atoms or propylene and another .alpha.-olefin having 5 to 10 carbon atoms, or a terpolymer of ethylene and propylene and butylene or ethylene and propylene and another .alpha.-olefin having 5 to 10 carbon atoms. This polymer mixture of top layer A further contains a high-viscosity polydiorganosiloxane and silicon dioxide and, if appropriate, other added additives. Top layer C contains a copolymer of ethylene and propylene or ethylene and butylene or propylene and butylene or ethylene and another .alpha.-olefin having 5 to 10 carbon atoms or propylene and another .alpha. -olefin having 5 to 10 carbon atoms, or a terpolymer of ethylene and propylene and butylene or ethylene and propylene and another .alpha.-olefin having 5 to 10 carbon atoms and, if appropriate, other additives. Top-layer C has a non-cohesive covering of polydialkylsiloxane on its outer surface. The film is useful, for example, as a packaging film and in the production of laminates.

Transparent polyolefin multilayer film having a low sealing temperature

A biaxially oriented multilayer film composed of a base layer and at least one outer layer. The base layer contains a propylene polymer. The outer layer contains two components A and B, the component A being composed of a high-density polyethylene (HDPE) and the component B of a copolymer of ethylene and propylene or ethylene and butylene or propylene and butylene or ethylene and another .alpha.-olefin containing 5 to 10 carbon atoms or propylene and another .alpha.-olefin containing 5 to 10 carbon atoms or of a terpolymer of ethylene and propylene and butylene or ethylene and propylene and another .alpha.-olefin containing 5 to 10 carbon atoms or of a mixture of two or more of the copolymers and/or terpolymers mentioned. The film has excellent properties and is useful, for example, as a packaging film, in a laminate, and as a backing film.

Sealable, matt, biaxially oriented multilayer polyolefin film

A nonsealable, matt, hazy, biaxially oriented multilayer film comprising a base layer and at least one outer layer wherein the base layer contains a propylene polymer and the outer layer(s) contain(s) high-density polyethylene (HDPE) and a polypropylene polymer. The film has a haze value, measured in accordance with ASTM D 1003, of greater than 40. The film is useful, for example, in the production of laminates or as a backing film for an adhesive on coating.

Nonsealable, matt, hazy, biaxially oriented multilayer polyolefin film,

A printable, biaxially oriented polyolefin multilayer film which is low-temperature sealing on both sides and comprises a base layer and at least one sealing layer on each side of the base layer, the base layer containing a peroxide-degraded propylene homopolymer and each sealing layer containing an ethylene/propylene/butylene terpolymer and a propylene/butylene copolymer, one outer sealing layer containing a polydiorganosiloxane and silicon dioxide particles and not being corona-treated and the polydiorganosiloxane being added in the form of a masterbatch during the film production, results in a multilayer film especially useful as a packaging film.

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Wiesbaden, Germany

Angela Speith