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US3758661A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for producing a synthetic paper

Assignee: Sekisui Chemical Co Ltd
•
Filing: 1970-12-24
•
Granted: 1973-09-11
•
Expires: 1990-12-24
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Abstract

Abstract A synthetic paper comprising an olefinic resin is produced by stretching an unstretched sheet of an olefinic resin such as polyethylene under the temperature conditions (1) or (2) below: 1. AT A TEMPERATURE LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN, THE TEMPERATURE OF THE INNER LAYER OF THE SHEET BEING DIFFERENT FROM THAT OF BOTH SURFACE LAYERS BY AT LEAST 10*C., and 2. AT A TEMPERATURE SUCH THAT EITHER ONE OF THE SURFACE LAYERS AND THE INNER LAYER IS MAINTAINED AT A TEMPERATURE LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN, AND THE OTHER IS MAINTAINED AT A TEMPERATURE NOT LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN AND HIGHER THAN THE MELTING TEMPERATURE BY 40*C. or less. The synthetic paper is light in weight and has high strength in addition to other desirable properties and finds utility as packaging and printing.

Inventors

  • 👤 A Nishio
  • 👤 S Yamamoto
  • 👤 S Honda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 23:34
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; Y; Y10; Y10S; Y10S264/00; Y10S264/13; Y10S264/71; Y10S264/73

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 33 words
AT A TEMPERATURE LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN, THE TEMPERATURE OF THE INNER LAYER OF THE SHEET BEING DIFFERENT FROM THAT OF BOTH SURFACE LAYERS BY AT LEAST 10*C., AND
Claim 2
Dependent Claim 33 words
AT A TEMPERATURE LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN, THE TEMPERATURE OF THE INNER LAYER OF THE SHEET BEING DIFFERENT FROM THAT OF BOTH SURFACE LAYERS BY AT LEAST 10*C., AND
Claim 3
Dependent Claim 79 words
AT A TEMPERATURE SUCH THAT EITHER ONE OF THE SURFACE LAYERS AND THE INNER LAYER IS MAINTAINED AT A TEMPERATURE LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN, AND THE OTHER IS MAINTAINED AT A TEMPERATURE NOT LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN AND HIGHER THAN THE MELTING TEMPERATURE BY 40*C. OR LESS. THE SYNTHETIC PAPER IS LIGHT IN WEIGHT AND HAS HIGH STRENGTH IN ADDITION TO OTHER DESIRABLE POROPERTIES AND FINDS UTILITY AS PACKAGING AND PRINTING.
Claim 4
Dependent Claim 79 words
AT A TEMPERATURE SUCH THAT EITHER ONE OF THE SURFACE LAYERS AND THE INNER LAYER IS MAINTAINED AT A TEMPERATURE LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN, AND THE OTHER IS MAINTAINED AT A TEMPERATURE NOT LOWER THAN THE MELTING TEMPERATURE OF SAID RESIN AND HIGHER THAN THE MELTING TEMPERATURE BY 40*C. OR LESS. THE SYNTHETIC PAPER IS LIGHT IN WEIGHT AND HAS HIGH STRENGTH IN ADDITION TO OTHER DESIRABLE POROPERTIES AND FINDS UTILITY AS PACKAGING AND PRINTING.
Claim 5
Dependent Claim 42 words
The process of claim 1, in which the further stretching step is carried out at a temperature of not more than the melting temperature of said olefinic resin and lower than the temperature of the surface layers employed at the initial stretching.
Claim 6
Dependent Claim 43 words
The process of claim 1, in which said inorganic filler is selected from the group consisting of diatomaceous earth, silica, talc, kaolin, zeolite, mica, asbestos, calcium carbonate, magnesium carbonate, calcium sulfate, clay, alumina, barium sulfate, zinc sulfate, lithopone, titanium oxide and zinc flower.
Claim 7
Dependent Claim 34 words
The process of claim 1, in which the stretched sheet finally obtained is heat-treated at a temperature below the melting temperature of said olefinic resin under a tension which permits shrinking of the sheet.
Claim 8
Dependent Claim 15 words
The process of claim 1, in which the stretched sheet finally obtained is callender rolled.
Claim 9
Dependent Claim 17 words
The process of claim 1 wherein the melt index of the olefin resin is 0.05 to 5.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-09-10 1977-03-12 1977-09-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-09-10 1981-03-12 1981-09-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-09-10 1985-03-12 1985-09-11 $7700.00 Window Closed / Lapsed

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