US4379774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of biaxially stretched and embossed film composed of vinyl chloride polymers
Assignee: Hoechst AG
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Filing: 1981-09-21
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Granted: 1983-04-12
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Expires: 2001-09-21
Abstract
Abstract A process is described for the production of biaxially stretched and embossed polyvinyl chloride film, in which a polyvinyl chloride film is first stretched biaxially at specific stretching ratios and, immediately after being stretched, is embossed under specific conditions. The film produced by this process is employed with particular advantage as base film for adhesive tapes.
Inventors
- 👤 Heinz-Erhardt Andersen
- 👤 Jaek J. Brebels
- 👤 Klaus Matschke
- 👤 Franz Scheier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:28
CPC Classifications
B; B29; B29C; B29C59/00; B29C59/02; B29C59/04; B29C55/00; B29C55/02; B29C55/10; B29C55/12; B29C55/14; B29C55/146; B29K; B29K2027/00; B29K2027/06; B29K2995/00; B29K2995/0037; B29K2995/005; B29K2995/0053; B29K2995/0077; B29L; B29L2007/00; B29L2007/001; B29L2007/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
163 words
A process for the production of biaxially stretched and embossed polyvinyl chloride film which comprises (a) biaxially stretching a polyvinyl chloride film at a stretching temperature of 90° to 160° C. at a transverse stretching ratio of 1.2:1 to 2.2:1 and a longitudinal stretching ratio of 1.7:1 to 2.5:1, the product of the transverse and longitudinal stretching ratios not exceeding 3.8:1, and (b) immediately after stretching, before the polyvinyl chloride film stretched according to step (a) has cooled appreciably from the stretching temperature range of 90° to 160° C. utilized in step (a), embossing the film by means of an embossing unit comprising an embossing roller back-up cylinder, the temperature of the film as it comes on to the embossing roller being substantially within said stretching temperature range and the embossing roller having a temperature of -10° to +60° C. and the embossing pattern of the embossing roller being embossed into the film to a depth of embossing of 0.02 to 0.25 mm.
Claim 2
Dependent Claim
163 words
A process for the production of biaxially stretched and embossed polyvinyl chloride film which comprises (a) biaxially stretching a polyvinyl chloride film at a stretching temperature of 90° to 160° C. at a transverse stretching ratio of 1.2:1 to 2.2:1 and a longitudinal stretching ratio of 1.7:1 to 2.5:1, the product of the transverse and longitudinal stretching ratios not exceeding 3.8:1, and (b) immediately after stretching, before the polyvinyl chloride film stretched according to step (a) has cooled appreciably from the stretching temperature range of 90° to 160° C. utilized in step (a), embossing the film by means of an embossing unit comprising an embossing roller back-up cylinder, the temperature of the film as it comes on to the embossing roller being substantially within said stretching temperature range and the embossing roller having a temperature of -10° to +60° C. and the embossing pattern of the embossing roller being embossed into the film to a depth of embossing of 0.02 to 0.25 mm.
Claim 3
Dependent Claim
52 words
A process as claimed in claim 1, wherein the biaxial stretching is carried out at a temperature of 110° to 140° C. at a transverse stretching ratio of 1.3:1 to 1.8:1 and a longitudinal stretching ratio of 1.9:1 to 2.3:1, the product of the transverse and longitudinal stretching ratios not exceeding 3.5:1.
Claim 4
Dependent Claim
152 words
A process as claimed in claim 1, which comprises (a 1 ) stretching the polyvinyl chloride film transversely at a ratio of 1.2:1 to 2.2:1 at a temperature of 90° to 160° C., (a 2 ) after the transverse stretching, stretching the film longitudinally at a ratio of 1.7:1 to 2.5:1 at a temperature of 90° to 160° C., and in so doing (a 3 ) not exceeding a value of 3.8:1 for the product of the transverse and longitudinal stretching ratios, and (b) immediately after longitudinal stretching, embossing the film by means of an embossing unit, comprising an embossing roller and a back-up cylinder, the film being at a temperature of 90° to 160° C. and the embossing roller being at a temperature of -10° to +60° C. and the embossing pattern of the embossing roller being embossed into the film to a depth of embossing of 0.02 to 0.25 mm.
Claim 5
Dependent Claim
100 words
A process as claimed in claim 3, wherein the film is stretched transversely at a ratio of 1.3:1 to 1.8:1 at a temperature of 110° to 140° C., and is stretched longitudinally at a ratio of 1.9:1 to 2.3:1 at a temperature of 110° to 140° C., the product of the transverse and longitudinal stretching ratios not exceeding a value of 3.5:1 and, during the embossing, the film being at a temperature of 110° to 140° C. and the embossing roller being at a temperature of 5° to 30° C. and the depth of embossing being 0.05 to 0.18 mm.
Claim 6
Dependent Claim
31 words
A process as claimed in claim 1 wherein the polyvinyl chloride of the polyvinyl chloride film is a homopolymer or copolymer containing at least 50% by weight of polymerized vinyl chloride.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |