US5145950A
Expired / Lapsed
US
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Method of storing food or plant materials by wrapping with a stretched syndiotactic polystyrene film
Assignee: Dow Chemical Co
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Filing: 1991-02-04
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Granted: 1992-09-08
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Expires: 2011-02-04
Abstract
Abstract A method of wrapping plant materials for storage by wrapping the plant materials with a food wrapping material obtained by stretching a styrene-based polymer film with mainly syndiotactic configuration. The wrapping material is transparent, has gloss and is excellent in physical properties such as gas permeability and heat resistance making it very useful in the method for wrapping material such as vegetables and fruits requiring permeation and diffusion of gases such as oxygen and carbon dioxide.
Inventors
- 👤 Keisuke Funaki
- 👤 Komei Yamasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:15
CPC Classifications
B; B65; B65D; B65D75/00; B65D75/006; B65D85/00; B65D85/30; B65D85/34; C; C08; C08J; C08J5/00; C08J5/18; C08J7/00; C08J7/04; C08J7/048; C08J2325/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
79 words
A method of storing food materials including fruits or vegetables for an extended time comprising enclosing the fruit or vegetable with a wrapping material obtained by stretching a styrene polymer with a syndiotactic configuration, said polymer having a syndiotacticity in racemic pentad of at least 30%, and thereafter subjecting the polymer to heat treatment at a temperature ranging from about 120° C. to 270° C. for about 2 to 600 seconds, while holding the polymer in a tensed state.
Claim 2
Independent Claim
79 words
A method of storing food materials including fruits or vegetables for an extended time comprising enclosing the fruit or vegetable with a wrapping material obtained by stretching a styrene polymer with a syndiotactic configuration, said polymer having a syndiotacticity in racemic pentad of at least 30%, and thereafter subjecting the polymer to heat treatment at a temperature ranging from about 120° C. to 270° C. for about 2 to 600 seconds, while holding the polymer in a tensed state.
Claim 3
Dependent Claim
22 words
The method as claimed in claim 1, wherein the wrapping material is a film with a thickness of 5 to 1000 μm.
Claim 4
Dependent Claim
29 words
The method as claimed in claim 1, wherein the wrapping material is obtained by molding the styrene polymer into a sheet and then uniaxially or biaxially stretching the sheet.
Claim 5
Dependent Claim
18 words
The method as claimed in claim 3, wherein the sheet is uniaxially stretched to at least 2 times.
Claim 6
Dependent Claim
19 words
The method as claimed in claim 3, wherein the sheet is biaxially stretched each to at least 1.5 times.
Claim 7
Dependent Claim
25 words
The method as claimed in claim 1, wherein the wrapping material is obtained by subjecting the styrene polymer to inflation molding or stretch blow molding.
Claim 8
Dependent Claim
21 words
The method as claimed in claim 1, wherein the styrene polymer has a weight average molecular weight of at least 10,000.
Claim 9
Dependent Claim
20 words
The method as claimed in claim 1, wherein the styrene polymer has a melting point of 160° to 310° C.
Claim 10
Dependent Claim
51 words
The method of claim 1, wherein the wrapping material is obtained by heat melting said styrene polymer or a composition containing the styrene polymer, cooling the resulting molten material to form a sheet, and then subjecting the sheet to biaxially stretching by at least 1.5 times in each direction with heating.
Claim 11
Dependent Claim
30 words
The method as claimed in claim 9, wherein the heat melting temperature is between the melting point of the styrene polymer and a temperature 30° C. above the decomposition temperature.
Claim 12
Dependent Claim
43 words
The method as claimed in claim 9, wherein the cooling temperature is not higher than the glass transition temperature of the styrene polymer, and the stretching temperature is between the glass transition temperature and a temperature 50° C. above the cold crystallization temperature.
Claim 13
Dependent Claim
27 words
The method of claim 1 wherein the heat treatment is at a temperature of 200° C. to 270° C. for a time of 2 to 60 seconds.
Claim 14
Independent Claim
74 words
A method of storing cut flowers for an extended time comprising enclosing the cut flowers with a wrapping material obtained by stretching a styrene polymer with a syndiotactic configuration, said polymer having a syndiotacticity in racemic pentad of at least 30%, and thereafter subjecting the polymer to heat treatment at a temperature ranging from about 120° C. to 270° C. for about 2 to 600 seconds, while holding the polymer in a tensed state.
Claim 15
Independent Claim
74 words
A method of storing cut flowers for an extended time comprising enclosing the cut flowers with a wrapping material obtained by stretching a styrene polymer with a syndiotactic configuration, said polymer having a syndiotacticity in racemic pentad of at least 30%, and thereafter subjecting the polymer to heat treatment at a temperature ranging from about 120° C. to 270° C. for about 2 to 600 seconds, while holding the polymer in a tensed state.
Claim 16
Dependent Claim
42 words
The method of claim 13, wherein the wrapping material is a film with a thickness of 5 to 1,000 μm and is obtained by molding the styrene polymer into a sheet and then uniaxially stretching the sheet by at least 1.5 times.
Claim 17
Dependent Claim
45 words
The method of claim 13, wherein the wrapping material is a film with a thickness of 5 to 1,000 μm and is obtained by molding the styrene polymer into a sheet and then biaxially stretching the sheet by at least 1.5 times in each direction.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |