TH42748A - Polypropylene film and multilayer polypropylene film. - Google Patents

Abstract

DC60 (01/03/43) This work is on multilayer films with layers using polypropylene compounds derived from crystalline polypropylene and propylene copolymer with alpha-olefin. The maximum viscosity of the copolymer is less than 6.5 dl/g. The viscosity comparison ratio between the maximum viscosity of the copolymer [n] rc and the maximum viscosity of the polypropylene [n] pp is 0.6 - 1.2, and the product of the maximum viscosity comparison ratio to weight of the copolymer with polypropylene ([n] rc / [n] pp) X (Wpp / Wrc) is between 0.2 - 4.5 for at least one layer. This work is on multilayer films with layers using polypropylene compounds derived from crystalline polypropylene and propylene copolymer with alpha-olefin. The maximum viscosity of the copolymer is less than 6.5 dl/g. The viscosity comparison ratio between the maximum viscosity of the copolymer [n] rc and the maximum viscosity of the polypropylene [n] pp is 0.6 - 1.2, and the product of the maximum viscosity comparison ratio by weight of the copolymer and polypropylene ( [n] rc / [n] pp ) X ( Wpp / Wrc) is between 0.2 - 4.5 for at least one layer.

Claims (11)

1. Films using polypropylene compounds derived from polypropylene and propylene-alpha-olefin copolymers have a maximum viscosity of the copolymer [n] RC less than 6.5 dI/g. The ratio of the maximum viscosity of the copolymer [n] RC to the maximum viscosity of the polypropylene [n] pp [n] RC / [n] pp] is 0.6-1.2, where the weight of polypropylene is defined as Wpp, the weight of the copolymer as WRC, and the product of the ratio of the weights Wpp / WRC to [n] RC / [n] pp ( [n] RC / [n] pp) X ( Wpp / WRC ) is in the range of 0.2-4.5. 2. Films under claim 1 that are propylene-alpha-olefin copolymers containing propylene, with polypropylene crystals of weight not exceeding 90% to 98.5% or 99.5% to 100%. 3. The film in item 1 is a copolymer of propylene and alpha-olefin, containing 25-55% alpha-olefin copolymer by weight. 4. Films under claim 1 that are propylene-ethylene copolymers blended with propylene, in which the polypropylene crystalline material is 90% not exceeding 98.5% or 99.5% not exceeding 100% by weight. 5. A film under claim 1, which is a copolymer of propylene and ethylene with 25-45% ethylene copolymer. 6. A multilayer film containing at least one layer of polypropylene compounds as specified in Patent 1. 7. A multilayer film with inherent toughness, comprising at least one superficial film as described in Claim 1. 8. A three-layer polypropylene multilayer film for high-temperature sterilization packaging, consisting of a middle layer film made of the polypropylene compound described in Patent 1, and an outer layer film made of either a single propylene copolymer with a crystalline melting point of 160-165°C or a propylene-alpha-olefin copolymer with a crystalline melting point of 145-160°C. 9. Multilayer polypropylene film for high-temperature sterilization packaging as per claim 8, where the thickness of the middle layer film is 20-80% compared to the overall thickness of the entire film. 10. Multilayer polypropylene film for high-temperature sterilization packaging as per Patent 8, with a Melt Flow Rate: MFR/film (at 230°C) between 0.5 - 5.0 g/10 min. 11. Multilayer polypropylene film as specified in claim 8, where the difference between the haze value of the film after sterilization at a high temperature of 120 to 140 degrees (HAZE/after) and the haze value before sterilization (HAZE/before) does not exceed 5%.