US3773609A
Expired / Lapsed
US
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Process for preparing film of crystalline propylene polymer having good heat sealability at low temperature
Assignee: JNC Corp
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Filing: 1971-09-09
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Granted: 1973-11-20
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Expires: 1991-09-09
Abstract
Abstract A film having a good heat sealability at a low temperature is prepared by biaxially stretching a film comprising a composition consisting of 95 to 60 percent by weight of crystalline propylene polymer and 5 to 40 percent by weight of an alicyclic resin having a softening point of 85* to 140*C and a bromine value of not more than 14, prepared by hydrogenation of an aromatic hydrocarbon resin, and then subjecting at least one side of the film to an oxidation treatment. Said composition can contain inorganic fillers such as silica, calcium carbonate, etc. and/or a bisamide, and the heat sealability at a low temperature of the thus obtained film can be maintained, and an antiblocking property is endowed to the film thereby.
Inventors
- 👤 H Haruta
- 👤 M Muraki
- 👤 T Ishibashi
- 👤 F Mushiaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:44
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/10; C08L23/14; C08L23/142; C08L57/00; C08L57/02; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
14 words
A process according to claim 1, wherein the crystalline propylene polymer is crystalline polypropylene.
Claim 2
Dependent Claim
24 words
A process according to claim 1, wherein the alicyclic resin has a softening point of 100* to 135*C measured by ring and ball method.
Claim 3
Dependent Claim
55 words
A process according to claim 1, wherein the alicyclic resin is a resin obtained by polymerizing a fraction rich in vinyl aromatic hydrocarbon obtained by distilling petroleum cracking products, and hydrogenerating the resulting resin having a polymerization degree of 2 to 7 until unsaturated bonds including double bonds in aromatic rings are almost completely saturated.
Claim 4
Dependent Claim
32 words
A process according to claim 1, wherein the composition consists of 93 to 80 percent by weight of crystalline propylene polymer and 7 to 20 percent by weight of an alicyclic resin.
Claim 5
Dependent Claim
15 words
A process according to claim 1, wherein the oxidation treatment is a corona discharge treatment.
Claim 6
Dependent Claim
28 words
A process according to claim 6, wherein the corona discharge treatment is conducted to give a wetting tension of at least 35 dynes/cm measured by ASTM D-2578-67 procedure.
Claim 7
Dependent Claim
20 words
A process according to claim 1, wherein the stretching is carried out at a stretching ratio of at least 4.
Claim 8
Dependent Claim
38 words
A process according to claim 1, wherein the stretching is carried out at a stretching ratio of at least 4, and at a ratio of the longitudinal stretching ratio to the lateral stretching ratio of 0.5 to 1.5.
Claim 9
Dependent Claim
126 words
A process for preparing a transparent film having a good heat sealability at a low temperature, which comprises meltinG a composition consisting of 95 to 60 percent by weight of crystalline propylene polymer and 5 to 40 percent by weight of an alicyclic resin having a softening point of 85* to 140*C measured by ring and ball method and a bromine value of not more than 14, extruding the melted composition into a sheet, cooling the same to solidify it, stretching the sheet at 90* to 170*C in at least one direction of the longitudinal and lateral ones, subjecting at least one surface of the thus obtained film to an oxidation treatment, then cooling the film to about 40*C or less, and winding up the film.
Claim 10
Dependent Claim
152 words
A biaxially stretched film having a composition consisting of 95 to 60 percent by weight of crystalline propylene polymer and 5 to 40 percent by weight of an alicyclic resin having a softening point of 90* to 140*C measured by ring and ball method and a bromine value of not more than 14, and subjected to an oxidation treatment on at least one surface thereof, and having a peeling resistance of at least 150 g/15 mm, determined by a method wherein two strips of said film each having a width of 15 mm are disposed upon each other so that the surfaces subjected to the oxidation treatment can be faced with each other; bonded over the entire width under a load of 1 kg/cm2 at a temperature of 135*C for 1 second; and subjected to T-type peeling strips at a peeling speed of 300 mm/min. and an angle of peeling of 180*.
Claim 11
Dependent Claim
144 words
A process for preparing a transparent film having a good heat sealability at a low temperature, which comprises melting a composition consisting of 95 to 60 percent by weight of crystalline propylene polymer and 5 to 40 percent by weight of an alicyclic resin having a softening point of 85* to 140*C measured by ring and ball method, and a bromine value of not more than 14, said composition further containing 0.02 to 0.7 percent by weight based upon the weight of the composition, of at least one member selected from the group consisting of inorganic fillers and bisamides, extruding the melted composition into a sheet, cooling the same to solidify it, stretching the sheet at 90* to 170*C in at least one direction of the longitudinal and lateral ones, and subjecting at least one surface of the resulting film to an oxidation treatment.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |