US3921844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat insulating container having plastic walls retaining vacuum
Assignee: Dow Chemical Co
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Filing: 1974-08-15
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Granted: 1975-11-25
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Expires: 1994-08-15
Abstract
Abstract A container having a double wall construction of a structural plastic material is provided with improved thermal insulative properties by (1) metallizing at least one surface of each wall of the container with metal such as silver to provide a light reflective surface and to produce a partial barrier to atmospheric gases, (2) coating the metallized surface with a barrier plastic such as saran, (3) evacuating the space enclosed by the walls of the container, and (4) adding to the evacuated space a gas-absorbing material.
Inventors
- 👤 Wilhelm E Walles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:41
CPC Classifications
A; A47; A47J; A47J41/00; A47J41/02; A47J41/022; B; B32; B32B; B32B15/00; B32B15/04; B32B15/08; B65; B65D; B65D11/00; B65D11/16; B65D81/00; B65D81/38; B65D81/3837; B65D81/3846; F; F17; F17C; F17C13/00; F17C13/001; F17C3/00; F17C3/02; F17C3/08; F17C2201/00; F17C2201/01; F17C2201/0104; F17C2201/0109; F17C2203/00; F17C2203/03; F17C2203/0391; F17C2203/06; F17C2203/0602; F17C2203/0607; F17C2203/0612; F17C2203/0626; F17C2203/0629; F17C2203/0634; F17C2203/0636; F17C2203/0646; F17C2203/0648; F17C2203/0658; F17C2203/0663; F17C2203/0673; F17C2203/068; F17C2209/00; F17C2209/21; F17C2209/2109; F17C2209/2118; F17C2209/23; F17C2209/232; F17C2221/00; F17C2221/01; F17C2221/011; F17C2221/013; F17C2221/014; F17C2221/016; F17C2223/00; F17C2223/01; F17C2223/0107; F17C2223/0123; F17C2260/00; F17C2260/01; F17C2260/011; F17C2260/03; F17C2260/031; F17C2260/033; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1355; Y10T428/1359
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
80 words
A PLASTIC CONTAINER HAVING DOUBLE WALL CONSTRUCTION CAPABLE OF RETAINING A VOCUUM FOR A SUBSTANTIAL PERIOD OF TIME, SAID CONTAINER COMPRISING A BOUNDARY OF A NORMALLY SOLID, PLASTIC MATERIAL ENCLOSING AN EVACUATED SPACE, A LAYER OF METAL ON AT LEAST ONE SURFACE OF SAID BOUNDARY WALL, AN OVERCOATING OF A BARRIER PLASTIC ADHERENT TO THE METAL LAYER AND A GASABSORBING METAL RESIDING IN THE EVACUATED SPACE, SAID GASABSORBING MATERIAL COMPRISING AN ALKOXIDE OF AN ALKALI METAL OR ALKALINE EARTH METAL.
Claim 2
Dependent Claim
80 words
A PLASTIC CONTAINER HAVING DOUBLE WALL CONSTRUCTION CAPABLE OF RETAINING A VOCUUM FOR A SUBSTANTIAL PERIOD OF TIME, SAID CONTAINER COMPRISING A BOUNDARY OF A NORMALLY SOLID, PLASTIC MATERIAL ENCLOSING AN EVACUATED SPACE, A LAYER OF METAL ON AT LEAST ONE SURFACE OF SAID BOUNDARY WALL, AN OVERCOATING OF A BARRIER PLASTIC ADHERENT TO THE METAL LAYER AND A GASABSORBING METAL RESIDING IN THE EVACUATED SPACE, SAID GASABSORBING MATERIAL COMPRISING AN ALKOXIDE OF AN ALKALI METAL OR ALKALINE EARTH METAL.
Claim 3
Dependent Claim
26 words
The plastic container of claim 1 wherein the metal layer is on the surface of the boundary wall which is most proximate to the evacuated space.
Claim 4
Dependent Claim
26 words
The plastic container of claim 1 wherein the barrier plastic exhibits a permeance to gases of the atmosphere of less than about 0.9 cc/100 sq. in./mil/day.
Claim 5
Dependent Claim
15 words
The plastic container of claim 3 wherein the barrier plastic is a vinylidene chloride copolymer.
Claim 6
Dependent Claim
11 words
The plastic container of claim 1 wherein the metal is silver.
Claim 7
Dependent Claim
58 words
The plastic container of claim 1 wherein the thickness of the boundary wall is in the range from about 40 to about 300 mils, the thickness of the metal layer is in the range from about 0.0001 to about 0.5 mil and the thickness of the overcoating is in the range from about 0.001 to about 2.5 mils.
Claim 8
Dependent Claim
31 words
The plastic container of claim 1 wherein the gas-absorbing material comprises an alkoxide of an alkali metal or alkaline earth metal and activated charcoal in the form of a particulate solid.
Claim 9
Dependent Claim
24 words
The plastic container according to claim 1 wherein the plastic material of the boundary wall is a polymer of a monovinylidene aromatic carbocyclic monomer.
Claim 10
Dependent Claim
15 words
The plastic container of claim 1 wherein the alkoxide has 2 or more carbon atoms.
Claim 11
Dependent Claim
20 words
The plastic container of claim 1 wherein the alkoxide is an alkoxide of lithium having 3 to 10 carbon atoms.
Claim 12
Dependent Claim
98 words
A method for making the plastic container of claim 1 comprising the Steps of rendering a surface of the boundary wall water wettable, depositing a layer of tin upon the water wettable surface depositing a metal on the tin surface to form an essentially continuous layer thereof, applying the barrier plastic in the form of a latex to the resulting metal layer to form an essentially continuous layer of the barrier plastic adherent to the metal layer, evacuating the enclosed space, adding a gas-absorbing material to the enclosed space and hermetically sealing the evacuated space from the atmosphere.
Claim 13
Dependent Claim
23 words
The method of claim 11 wherein the amount of tin deposited is in the range from about 0.5 to about 50 micrograms/square centimeter.
Claim 14
Dependent Claim
10 words
A plastic container made by the method of claim 11.
Claim 15
Dependent Claim
13 words
The plastic container of claim 13 wherein the gas-absorbing material is lithium isopropoxide.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |