EP0045064A2
Expired / Lapsed
EP
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Uniaxially drawn oriented polyolefin film for electric insulation and manufacturing method for the same
Assignee: Furukawa Electric Co Ltd
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Filing: 1981-07-23
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Granted: —
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Expires: 2001-07-23
Abstract
Abstract A uniaxially drawn oriented polyolefin film for cable insulation. has a thickness of 80 to 250 µ and is com. posed of a crystalline polyolefin having a melt index of 10 or more and 0.5 to 20 phr of unsintered polytetrafluoroethylene, wherein the added unsintered polytetrafluoroethylene is in the form of microfibrous particles uniformly dispersed in the crystalline polyolefin as a matrix so as to be parallel to the orientation axis of the polyolefin; an apparent MI value of the film is 1/4 to 1/10 of the Ml value of the crystalline polyolefin used; the tensile Young's modulus of the film in the direction of the orientation axis is 2 <sub>X</sub> 10<sup>4</sup> kg/cm<sup>2</sup> or more; and the change in the thickness of the film in dodecylbenzene at 100°C is 10% or less. A method for manufacturing this film is also provided.
Inventors
- 👤 Hikaru Shii
- 👤 Fumio Sugimoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 12:37
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; C08L; C08L23/00; C08L23/02; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/441; H01B3/443; H01B3/445; C08J2323/00; C08J2323/02; Y; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
132 words
A uniaxially drawn oriented polyolefin film for cable insulation, having a thickness of 80 to 250 u and composed of a crystalline polyolefin having a melt index of 10 or more and 0.5 to 20 phr of unsintered polytetrafluoroethylene, wherein the added unsintered polytetrafluoroethylene is in the form of microfibrous particles uniformly dispersed in the crystalline polyolefin as a matrix so as to be parallel to the orientation axis of the polyolefin; an apparent MI value of the film is 1/4 to 1/10 of the MI value of the crystalline polyolefin used; the tensile Young's modulus of the film in the direction of the orientation axis is 2 x 10 4 kg/cm 2 or more; and the change in the thickness of the film in dodecylbenzene at 100°C is 10% or less.
Claim 2
Dependent Claim
132 words
A uniaxially drawn oriented polyolefin film for cable insulation, having a thickness of 80 to 250 u and composed of a crystalline polyolefin having a melt index of 10 or more and 0.5 to 20 phr of unsintered polytetrafluoroethylene, wherein the added unsintered polytetrafluoroethylene is in the form of microfibrous particles uniformly dispersed in the crystalline polyolefin as a matrix so as to be parallel to the orientation axis of the polyolefin; an apparent MI value of the film is 1/4 to 1/10 of the MI value of the crystalline polyolefin used; the tensile Young's modulus of the film in the direction of the orientation axis is 2 x 10 4 kg/cm 2 or more; and the change in the thickness of the film in dodecylbenzene at 100°C is 10% or less.
Claim 3
Dependent Claim
17 words
A polyolefin film according to claim 1, wherein the crystalline polyolefin as the matrix is isotactic polypropylene.
Claim 4
Dependent Claim
19 words
A polyolefin film according to claim 1, wherein the crystalline polyolefin as the matrix is a high density polyethylene.
Claim 5
Dependent Claim
22 words
A polyolefin film according to claim 1, wherein the melt index of the crystalline polyolefin as the matrix is 15 or more.
Claim 6
Dependent Claim
12 words
A polyolefin film according to claim 1, wherein the film is embossed.
Claim 7
Independent Claim
116 words
A method of manufacturing a uniaxially drawn oriented polyolefin film for cable insulation characterized by dispersing 0.5 to 20 phr of finely-divided unsintered polytetrafluoroethylene in a finely-divided crystalline polyolefin having a melt index of 10 or more in such a manner that the particles do not substantially stick together to form a coherent mass; extruding the resultant mixture with an extruder capable of exerting high shearing stress; forming the extrudate into a sheet; and changing the thickness of the resultant sheet to 1/2 to 1/10 of the original thickness at a temperature range of 50° to 20°C lower than the melting point of the polyolefin used, to provide a film 80 to 250 p in thickness.
Claim 8
Independent Claim
116 words
A method of manufacturing a uniaxially drawn oriented polyolefin film for cable insulation characterized by dispersing 0.5 to 20 phr of finely-divided unsintered polytetrafluoroethylene in a finely-divided crystalline polyolefin having a melt index of 10 or more in such a manner that the particles do not substantially stick together to form a coherent mass; extruding the resultant mixture with an extruder capable of exerting high shearing stress; forming the extrudate into a sheet; and changing the thickness of the resultant sheet to 1/2 to 1/10 of the original thickness at a temperature range of 50° to 20°C lower than the melting point of the polyolefin used, to provide a film 80 to 250 p in thickness.
Claim 9
Dependent Claim
18 words
A method according to claim 6, characterized by using isotactic polypropylene as the crystalline polyolefin of the matrix.
Claim 10
Dependent Claim
20 words
A method according to claim 6, characterized by using a high density polyethylene as the crystalline polyolefin of the matrix.
Claim 11
Dependent Claim
48 words
A method according to claim 6, characterized by uniformly mixing aqueous colloidal dispersions of unsintered polytetrafluoroethylene with the finely-divided powdered crystalline polyolefin and thereafter drying the mixture so that the finely-divided unsintered polytetrafluoroethylene may be dispersed in the finely-divided powdered crystalline polyolefin substantially without forming a coherent mass.
Claim 12
Dependent Claim
24 words
A method according to claim 6, characterized by embossing the obtained uniaxially drawn oriented polyolefin film at a temperature lower than the drawing temperature.
Claim 13
Dependent Claim
28 words
A method according to claim 6, characterized by changing the thickness of the sheet to 1/2 to 1/10 of the original thickness by rolling, drawing, or the both.
Claim 14
Dependent Claim
43 words
A method according to claim 6, characterized by forming into sheets the mixture of the crystalline polyolefin with the unsintered polytetrafluoroethylene dispersed therein by a sheet-forming device having a forming die on a twin-screw type extruder with an L/D of 15 or more.
Claim 15
Dependent Claim
55 words
A method according to claim 6, characterized by forming into strands the mixture of the crystalline polyolefin with the unsintered polytetrafluoroethylene dispersed therein by a twin-screw type extruder with an L/D of 15 or more, pelletizing the strands by a strand cutter into pellets, and forming the pellets into sheets by a normal single-screw extruder.
References Cited (Backward Citations)
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