Abstract: This invention concerns biaxially oriented polypropylene films containing from 1 to 40 percent by weight of a hydrocarbon resin, the resin being substantially miscible with the polypropylene, and the film having a crease retention of at least 50% as measured by ASTM D920-49. The hydrocarbon resin is preferably a terpene resin, a hydrogenated synthetic resin or a compatible rosin. Crease retention values in excess of 70% have been achieved in particular by orienting the films at a temperature of at least 10 Centigrade degrees below the crystalline melting point of the polypropylene.

Abstract: This invention concerns biaxially oriented polypropylene films containing from 1 to 40 percent by weight of a hydrocarbon resin, the resin being substantially miscible with the polypropylene, and the film having a crease retention of at least 50% as measured by ASTM D920-49. The hydrocarbon resin is preferably a terpene resin, a hydrogenated synthetic resin or a compatible rosin. Crease retention values in excess of 70% have been achieved in particular by orienting the films at a temperature of at least 10 Centigrade degrees below the crystalline melting point of the polypropylene.

Abstract: A heat sealable polymeric film, heat sealing being provided by a blend of (a) from 25 to 75 percent of propylene/ethylene copolymer containing from 2 to 8 percent by weight of units derived from ethylene, (b) from 1 to 60 percent of but-1-ene/ethylene copolymer containing up to 1 percent by weight of units derived from ethylene, and (c) from 1 to 60 percent of but-1-ene/ethylene copolymer containing from 3 to 10 percent by weight of units derived from ethylene, the percentages of the various copolymers being based on the total weight of the blend. Films of the invention have low heat seal threshold temperatures combined with broad ranges of continuous hot tack.

Abstract: Polymeric films, especially for packaging, consist of a relatively thick layer of a polyolefin having thereon a relatively thin layer of a blend of a polymer which has a low heat seal strength to polyvinylidene chloride and a copolymer containing units derived from an alkene and an unsaturated mono-basic carboxylic acid or an ester thereof. The relatively thick layer is preferably of polypropylene, and the relatively thin layer is preferably a blend of polyethylene with a copolymer containing at least 74 percent by weight of units derived from ethylene and not more than 36 percent by weight of units derived from acrylic acid or an ester thereof. The relatively thin layer has good anti-block with the relatively thick layer and to other layers such as PVdC applied thereto, and the relatively thin layers have good heat seal strengths to themselves and such other layers.

Abstract: This invention concerns the production of oriented polymeric films in which a layer of an ambient temperature curable silicone resin composition is formed on a layer of a polymeric film which is thereafter stretched at an elevated temperature to effect orientation of the film. The silicone resin composition includes a volatile inhibitor for inhibiting curing of the composition while stretching is effected. Suitable inhibitors include alkanols when the silicone resin has hydroxyl functionality. Films so produced can be used as release films.

Abstract: The invention concerns polymeric films including a layer of polypropylene homopolymer with a layer of voided polypropylene on one side and a layer of a printable polymer on the other side.The printable polymer is preferably an acrylic polymer, a co- or terpolymer containing units derived form at least two of ethylene, propylene or but-1-ene, and/or a linear low density polyethylene. Films of the present invention have good gloss combined with printability and a pearlescent effect. They can also provide evidence of tampering with packaged goods.

Abstract: The invention concerns polymeric films which can be used for twist wrap, for example for confectionery. Films of the invention have a layer of a blend of high density polyethylene with a polyethylene of lower density, a layer of high density polyethylene being provided on each surface of the blend. In general films of the invention will be produced by coextrusion and then uniaxially stretched in the machine direction. It has been possible to cut such films satisfactorily in a direction transverse to the direction of stretch using an oscillating cutter blade of the type used to cut films of reconstituted cellulose.

Abstract: The invention concerns polymeric films, in particular, but not exclusively, in the form of synthetic paper. The films have a rough surface provided by a blend of a first polymer having a melt flow index of not more than 1 g/10 mins as measured by ASTM D1238/73 (condition L) with at least one polymer chemically incompatible with the first polymer. The first polymer preferably does not flow under these conditions, and the incompatible polymer preferably has a melt flow index of from 4 to 50 g/10 mins under ASTM D1238/73 (condition L). The polymers of each layer are preferably polyolefins. The base layer is of voided polypropylene. The rough surface can provide writeability, or it can be printed or metallized to provide a unique appearance.

Abstract: This invention provides multilayer polymeric films including a layer of nylon polymer having a Vicat A(DIN 53460) softening point of not more than 170.degree. C. and being substantially impermeable to styrene, and a layer of a weldable synthetic plastics composition bonded to the layer of the nylon polymer. Such films can be used to recondition pipes, for example sewer pipes. They have the advantage of being resistant to swelling by synthetic resin compositions, particularly styrene, used to impregnate a fibrous mat which is bonded to the film when used to recondition pipes. In addition, the films have shown resistance to puncturing.

Abstract: The invention concerns the production of oriented polymeric films in which a layer of a heat curable silicone resin composition is formed on a layer of a polymeric film which is thereafter stretched at an elevated temperature to effect orientation of the film. The heat curable silicone resin composition includes a volatile inhibitor for inhibiting curing of the composition while stretching is effected. Suitable inhibitors include volatile amines, alkynes and acetylene alcohols. Films so produced can be used as release films.