Process for producing the polypropylene film for electrical appl

Details Process for producing the polypropylene film for electrical appl Process for producing the polypropylene film for electrical appl

1977-05-06

1980-01-22

Thurlow, Jeffery R.

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Polymers from only ethylenic monomers or processes of...

264237, 264519, 264560, 264562, 4253261, 526351, C08F11006

Patent

active

041851480

ABSTRACT:
A polypropylene film which is useful for electrical devices is produced by biaxially stretching an unstretched polypropylene molded article having, on at least one side, a surface layer having .beta.-form crystals, of mean diameter over 7 .mu.m, under such conditions that the stretching temperature at the stretch initiation point is in the range of 145.degree. to 176.degree. C., and the stretch ratio in one direction is less than a factor of 8. The resulting stretched polypropylene film is characterized by excellent mechanical properties, a very dense inner structure, and high air-tightness. The surface of the film has an efficiently roughened, fine, uneven structure containing crater-like patterns or an isotropic network structure and an anisotropic network structure, which is aligned in the extrusion direction. Therefore, the polypropylene film of the present invention can be readily impregnated with insulating oils, and hence can be used in various electrical devices, such as capacitors, electric cables, transformers and the like.

REFERENCES:
patent: 2936492 (1960-05-01), Swerlick et al.
patent: 3007765 (1961-11-01), Ruyter
patent: 3246061 (1966-04-01), Blatz
patent: 3385918 (1968-05-01), Jack et al.
patent: 3450806 (1969-06-01), Matsuo et al.
patent: 3796781 (1974-03-01), Edwards et al.
patent: 3822333 (1974-07-01), Haruta et al.

Affiliated with

Also associated with

Rating

Process for producing the polypropylene film for electrical appl does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for producing the polypropylene film for electrical appl, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing the polypropylene film for electrical appl will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-334860