US4731266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water-resistant polyvinyl alcohol film and its application to the preparation of gas-impermeable composite articles
Assignee: Rhone Poulenc SA
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Filing: 1985-07-03
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Granted: 1988-03-15
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Expires: 2005-07-03
Abstract
Abstract Polyvinyl alcohol films are provided which are gelled, non-tacky, bubble-free and resistant to water at ambient temperatures. The polyvinyl alcohol film is obtained by plasticizing (fluxing) and melting granules of pure polyvinyl alcohol containing from 25 to 35% by weight of water at a temperature at least 100 DEG C. above the equilibrium melting point of the granules and less than or equal to 220 DEG C., and extruding the melted granules through a die at a temperature at least 5 DEG C. above the equilibrium melting point of the granules and less than or equal to 98 DEG C., optionally followed by monoaxial stretching or biaxial stretching of the unstretched film obtained. The stretched or unstretched film may be heat-treated to improve its properties. The polyvinyl alcohol film can be used to prepare with thermoplastic films composite films or sheets having a high gas impermeability. The invention also provides composite, biaxially oriented, impermeable barrier layer coated, thermoplastic hollow shaped articles useful as packaging material, e.g., as packages and bottles for flavored foods and carbonated beverages. The hollow shaped articles are produced by externally barrier covering a thermoplastic tubular blank, parison or preform with a relativley thick barrier layer consisting essentially of water-resistant and highly crystalline polyvinyl alcohol, said barrier layer having been prepared by shaping a melt of homogeneously shear fluxed and molten flakes of pure polyvinyl alcohol having a water content of 25 to 35% by weight thereof, with said shear fluxing and melting of said polyvinyl alcohol flakes being at a temperature above the equilibrium melting point of the polyvinyl alcohol/water admixture essentially constituting said flakes, and said shaping being at a temperature of at least said equilibrium melting point but less then that at which the vapor pressure of the component water would effect the surface expansion and bubbling of the desired barrier layer, and then biaxially orienting and blow molding into final configuration said barrier covered blank, parison or preform.
Inventors
- 👤 Claude Bonnebat
- 👤 Louis Macabrey
- 👤 Gilbert Roullet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:15
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/09; B29C48/10; B29C48/25; B29C48/78; B29C48/86; B29C48/87; B29C48/875; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; B29C49/00; B29C49/22; B32; B32B; B32B27/00; B32B27/30; B29C49/42; B29C49/78; B29C2049/7879; B29C48/001; B29C48/0018; B29C48/0019; B29C48/0021; B29C48/0022; B29C48/022; B29C48/15; B29C48/151; B29C48/92; B29C49/08; B29C49/087; B29K; B29K2029/00; C08J2329/00; C08J2329/02; C08J2329/04; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1355; Y10T428/1359; Y10T428/1379; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/29; Y10T428/2982; Y10T428/31504; Y10T428/31507; Y10T428/31678; Y10T428/31681; Y10T428/31692; Y10T428/31699; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
30 words
A composite thermoplastic article comprising a gelled, non-tacky, buffle-free film which is composed of polyvinyl alcohol and which is resistant to water at ambient temperature adhered to a thermoplastic material.
Claim 2
Dependent Claim
30 words
A composite thermoplastic article comprising a gelled, non-tacky, buffle-free film which is composed of polyvinyl alcohol and which is resistant to water at ambient temperature adhered to a thermoplastic material.
Claim 3
Dependent Claim
62 words
The composite thermoplastic article according to claim 1, which is prepared by: providing an unstretched thermoplastic film which is coated on one surface with an adhesive which is compatible with the thermoplastic and with the polyvinyl alcohol, depositing the polyvinyl alcohol film while unstretched on the adhesive-coated surface of the unstretched thermoplastic film; and monoaxially or biaxially stretching the composite film obtained.
Claim 4
Dependent Claim
20 words
The composite article according to claim 2 which is longitudinally stretched to a longitudinal stretch ratio of 2 to 5.
Claim 5
Dependent Claim
20 words
The composite article according to claim 3 which is transversely stretched to a transverse stretch ratio of 2 to 8.
Claim 6
Dependent Claim
21 words
The composite article according to claim 3 which has been transversely stretched to a transverse stretch ratio of 2 to 8.
Claim 7
Dependent Claim
21 words
The composite article according to claim 2 which has been heat treated at a temperature of about 140° to 220° C.
Claim 8
Dependent Claim
22 words
The composite thermoplastic article according to claim 1 wherein the stretched composite article has been heat-treated at a temperature above 130° C.
Claim 9
Dependent Claim
54 words
The composite article according to claim 1 which is prepared by laminating said polyvinyl alcohol film which has been monoaxially or biaxially stretched, onto a monoaxially or biaxially stretched thermoplastic film which is coated on its surface with said polyvinyl alcohol film with an adhesive compatible with the thermoplastic and with the polyvinyl alcohol.
Claim 10
Dependent Claim
36 words
The composite article according to claim 8 wherein the stretched polyvinyl alcohol film is heat treated at a temperature of from about 140° C. to about 220° C. before being laminated onto the stretched thermoplastic film.
Claim 11
Dependent Claim
18 words
The composite article according to claim 9 which further comprises a metallized coating on the stretched thermoplastic film.
Claim 12
Dependent Claim
16 words
The composite article according to claim 1 which is in the form of a hollow cylinder.
Claim 13
Dependent Claim
29 words
The composite article of claim 11 which is unstretched and in which the polyvinyl alcohol film has a thickness in the range of from about 0.1 to 2 mm.
Claim 14
Dependent Claim
17 words
The composite article of claim 12 which has been biaxially oriented and blow-molded into a final configuration.
Claim 15
Dependent Claim
33 words
The composite article according to claim 1 which is subjected to a longitudinal stretching operation at a temperature of 100° to 130° C. to give a longitudinal stretch ratio of 2 to 5.
Claim 16
Dependent Claim
30 words
The composite article according to claim 14 which has been transversely stretched at a temperature of 100° to 150° C. to give a transverse stretch ratio of 2 to 8.
Claim 17
Dependent Claim
18 words
The composite article according to claim 15 which has been heat treated at a temperature above 130° C.
Claim 18
Dependent Claim
13 words
The composite thermoplastic article according to claim 1 which has been monoaxially stretched.
Claim 19
Dependent Claim
13 words
The composite thermoplastic article according to claim 1 which has been biaxially stretched.
Claim 20
Dependent Claim
32 words
The composite thermoplastic article according to claim 1 wherein the thermoplastic material is selected from the group consisting of polystyrene, polyvinyl chloride, polyacrylate, polycarbonate, polyethylene, polypropylene, ethylene/propylene copolymer, polybutene-1, polyamide, and polyester.
Claim 21
Dependent Claim
14 words
The composite thermoplastic article according to claim 1 wherein the thermoplastic material is polypropylene.
Claim 22
Dependent Claim
16 words
The composite thermoplastic article according to claim 1 wherein the thermoplastic material is poly(ethylene glycol terephthalate).
Claim 23
Dependent Claim
122 words
A composite thermoplastic article comprising a gelled, non-tacky, bubble-free film which is composed of polyvinyl alcohol and which is resistant to water at ambient temperature adhered to a thermoplastic material, wherein said polyvinyl alcohol film is obtained by fluxing and melting granules of polyvinyl alcohol, said granules containing from aabout 25% to about 35%, by weight, of water, at a temperature above the equilibrium melting point of the polyvinyl alcohol/water mixture forming said granules; and extruding the melted granules through a die at a temperature above the equilibrium melting point of the polyvinyl alcohol/water mixture, but below the temperature at which the water vapor pressure would be sufficient to cause the formation ob bubbles when the material is exposed to the air.
Claim 24
Dependent Claim
122 words
A composite thermoplastic article comprising a gelled, non-tacky, bubble-free film which is composed of polyvinyl alcohol and which is resistant to water at ambient temperature adhered to a thermoplastic material, wherein said polyvinyl alcohol film is obtained by fluxing and melting granules of polyvinyl alcohol, said granules containing from aabout 25% to about 35%, by weight, of water, at a temperature above the equilibrium melting point of the polyvinyl alcohol/water mixture forming said granules; and extruding the melted granules through a die at a temperature above the equilibrium melting point of the polyvinyl alcohol/water mixture, but below the temperature at which the water vapor pressure would be sufficient to cause the formation ob bubbles when the material is exposed to the air.
Claim 25
Dependent Claim
17 words
The composite article according to claim 22 wherein the melted granules are extruded through a flat die.
Claim 26
Dependent Claim
173 words
A composite thermoplastic article comprising a gelled, non-tacky, bubble-free film which is composed of polyvinyl alcohol and which is resistant to water at ambient temperture adhered to a thermoplastic material, which is the product obtained by preparing a layer of polyvinyl alcohol by extruding a molten aqueous solution of polyvinyl alcohol through a die, wherein (a) the molten material subjected to extrusion is obtained by plasticizing by shearing and melting granules of polyvinyl alcohol having an ester number of less than 20, which granules contain from 25 to 35% by weight of water, at a temperature above the equilibrium melting point of the polyvinyl alcohol/water mixture forming the granules; and (b) the operation of extrusion through the die is carried out at a temperature at least equal to the equilibrium melting point of the polyvinyl alcohol/water mixture, but below the temperature at which the water vapor pressure is sufficient to cause the formation of bubbles when the material is exposed to air, and adhering the so-formed polyvinyl alcohol layer to the thermoplastic material.
Claim 27
Dependent Claim
173 words
A composite thermoplastic article comprising a gelled, non-tacky, bubble-free film which is composed of polyvinyl alcohol and which is resistant to water at ambient temperture adhered to a thermoplastic material, which is the product obtained by preparing a layer of polyvinyl alcohol by extruding a molten aqueous solution of polyvinyl alcohol through a die, wherein (a) the molten material subjected to extrusion is obtained by plasticizing by shearing and melting granules of polyvinyl alcohol having an ester number of less than 20, which granules contain from 25 to 35% by weight of water, at a temperature above the equilibrium melting point of the polyvinyl alcohol/water mixture forming the granules; and (b) the operation of extrusion through the die is carried out at a temperature at least equal to the equilibrium melting point of the polyvinyl alcohol/water mixture, but below the temperature at which the water vapor pressure is sufficient to cause the formation of bubbles when the material is exposed to air, and adhering the so-formed polyvinyl alcohol layer to the thermoplastic material.
Claim 28
Dependent Claim
28 words
The composite thermoplastic article according to claim 24 wherein the thermoplastic material comprises a thermoplastic film substrate, said composite article being in the form of a flat film.
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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) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |